Forecast Discussions mentioning "ACARS", "MDCRS", "AIRCRAFT", "TAMDAR", or "AMDAR" received at FSL on 01/01/07

.EVENING UPDATE...

920 PM CST

STRONG VORT MAX LIFTING THROUGH DOWNSTREAM PORTION OF UPPER LOW ACROSS THE SOUTHERN GREAT LAKES WAS RESPONSIBLE FOR PRODUCING SHOWERS/EMBEDDED THUNDER EARLIER THIS EVENING...AND THE LAST OF THESE ECHOES NOW BEGINNING TO DEPART NORTHWEST INDIANA COUNTIES OF THE CWA. DECENT MID LEVEL COLD POCKET NOTED IN 00Z RAOBS FROM DVN/ILX WITH -9 DEG C AT 700 HPA WHICH YIELDED SOME LOW/MID LEVEL LAPSE RATES ON THE ORDER OF 8 DEG C/KM. SEVERAL REPORTS OF WIND GUSTS UP INTO THE 40 TO 45 MPH RANGE EARLIER THIS EVENING ACROSS SOUTHERN PORTIONS OF THE CWA INTO NORTHWEST INDIANA BUT THINGS QUIETING DOWN NOW WITH THE AFOREMENTIONED VORT MAX PULLING OFF TO THE EAST. STILL WILL MAINTAIN LOW CHANCE POPS FOR -RW/SW THROUGH THE OVERNIGHT HOURS AS A COLD FRONT ACROSS EASTERN IOWA TRACKS THROUGH NORTHERN ILLINOIS OVERNIGHT...AND AS ANOTHER REINFORCING UPPER LEVEL SHORT WAVE DROPS INTO THE SOUTHERN GREAT LAKES. MOST OF WRAP AROUND PRECIP SHOULD REMAIN TO THE NORTH AND NORTHWEST OF THE FORECAST AREA HOWEVER. TEMPS NOT CHANGED MUCH FROM INHERITED MINS WITH LOWS DROPPING INTO THE MID 30S ONCE COLD FRONT ARRIVES. OTHERWISE...WILL UPDATE FORECAST LATE THIS EVENING TO CLEAN UP PRECIP WORDING AND TO LOWER POPS.

MARSILI

&&

.PREV DISCUSSION FOR AFTERNOON GRIDS/ZONES...

248 PM CST

UPR LOW CENTERED OVR NRN MO THIS AFTN...WITH STRONG S/WV ASSOCIATED WITH 130KT JET STRK LIFTING NORTHEAST ACROSS MID MS/LWR OH VLYS. DRY SLOT OVR MUCH OF FCST AREA SINCE THIS MORNING STARTING TO SHOW SIGNS OF CONVECTIVE DVLPMNT...WITH SCT RW/TRW BEGINNING TO DVLP BENEATH DIVERGENT LEFT EXIT REGION OF UPPER JET STRK ALONG LOW LEVEL OCCLUDED FRONT AS UPPER LVL FORCING INCRSG WITH APPRCH OF S/WV. RECENT ACARS AND FCST SOUNDINGS AS WELL AS SPC/RUC MESOANALYSIS GRAPHICS INDICATE CAPE VALUES MARGINAL...THOUGH GIVEN STRENGTH OF UPPER FORCING AND LOW LEVEL CONVERGENCE VCNTY OCCLUSION EXPECT SCT RW/TRW TO CONTINUE NEXT FEW HOURS AS S/WV CONTINUES TO APPRCH. MAIN UPPER LOW CENTER LIFTS NORTHEAST ACROSS FCST AREA THIS EVENING...THOUGH SECONDARY VORT MAXIMA WRAPPING AROUND BACK SIDE RESULTS IN LINGERING UPPER TROUGHINESS AND EXTENDED PERIOD OF WEAK MID/UPR LVL FORCING INDICATED BY Q CONVERGENCE FIELDS. THIS S/WV TROUGH AXIS FINALLY MOVES ACROSS FCST AREA MONDAY MORNING...THUS EXPECT SOME LINGERING CHC FOR LIGHT SHOWERS OVRNGT HOURS INTO MONDAY MORNING.

LOW LEVEL COLD ADVCTN TNGT RESULTS IN THICKNESS VALUES FALLING ESPECIALLY AFTR MDNGT...WITH 1000-850 HPA BELOW 1300 METERS AND 850-700 HPA DOWN TO 1520-1530 METERS BY 12Z MON. FCST SOUNDINGS AND TSECTS INDICATE MOIST LAYER FAIRLY SHALLOW BY THAT TIME HOWEVER...WITH CLOUD TOP TEMPS GENERALLY WARMER THAN -10C THAT WOULD NOT SUPPORT SIG ICE CRYSTAL NUCLEATION. HOWEVER...GIVEN PROLONGED FORCING WITH SECOND VORT/TROUGH AND POTENTIAL FOR DEEPER CLOUD LAYER OR SEEDING FROM COLDER HIGHER CLOUD LAYER...WILL MENTION LIGHT RA/SN AFTER MDNT INTO MON MRNG. UPPER TROUGH AXIS THEN SHIFTS EAST OF FCST AREA BY AFTN...WITH MODEL TSECTS AND DIV-Q/OMEGA FIELDS SUGGESTING FAIRLY STRONG DEEP LAYER SUBSIDENCE DVLPG. THUS WILL GO DRY FOR MON AFTN WITH CLRG SKIES BY EVENING AS SFC HIGH PRESSURE BUILDS ACROSS MID MS/OH VLYS.

MID WEEK APPEARS DRY AND CONTINUED MILD AS ANOTHER UPPER TROUGH CUTS OFF/CLOSES OFF OVER THE SOUTHWEST...AND NORTHERN BRANCH OF JET BECOMES MORE ZONAL. GFS/NAM SIMILAR WITH NRN STRM S/WV MOVG THROUGH THE UPPER MIDWEST TUES/TUES NGT...THOUGH WITH DRY LOW LEVELS AND SFC RIDGE AXIS BLOCKING OFF MOISTURE RETURN FROM THE GULF EXPECT NO MORE THAN SOME MID/HIGH CLOUDS WITH THIS FEATURE. SOUTHWESTERN UPPER TROUGH KICKS OUT LATER IN THE WEEK...WITH GLOBAL MODELS DVLPG BROAD TROUGH IN SOMEWHAT PHASED NRN/SRN STREAMS BY FRI/SAT. BEST PCPN CHANCES INITIALLY TO OUR SOUTH AND OFF TO OUR NORTH...UNTIL MAIN UPPER TROUGH APPRCHS FRI NGT AND SATURDAY. WILL CARRY CHC POPS FOR INITIALLY RA FRI NGT AND THEN RA/SN SAT AS COLDER AIR MOVES IN BEHIND SFC COLD FRONT.

TEMPS THROUGH THE PERIOD AGAIN TO REMAIN FAIRLY MILD. MAV GUIDANCE NUMBERS GENERALLY PREFERRED EARLY ON...THEN GENERALLY AT OR A LITTLE ABOVE THE HPC/MEX NUMBERS MID WEEK AS LLVL SW FLOW DVLPS.

RATZER

&&

.AVIATION DISCUSSION FOR 00Z TAFS...

MAIN PROBLEM AGAIN THIS EVENING WILL BE VARIABLE CIGS. AREA IS IN DRY SLOT ASSD WITH DEEPENING LOW PRES CENTER LOCATED OVR CNTRL WI JUST ESE OF EAU AT 00Z. COLD POOL ALF ASSD WITH UPPER LVLS OF THIS SYS WILL BE MOVG ACRS IL TNGT. THIS AREA HAS HELPED DESTABILIZE AMS ENUF TO TRIGGER A BAND OF SHALLOW TOPPED CONVECTION OVR CNTRL IL. TSTMS NOW EXTENDING FROM E OF BMI-DNV WILL CONTINUE LIFTING NEWD ACRS EXTRM NERN IL/NWRN IND THRU 02Z. EXPECT TSTMS TO STAY S OF A PNT-IKK-GYY LN...WITH JUST SCT SHWRS TO N OF THIS LN. CIGS GENLY VFR THRU MUCH OF THIS EVENING XCP IN SHRWS WHERE BKN CIGS IN 2-3 TSD FT RANGE CAN BE EXPECTED. MORE SLD LOW RANGE MVFR CIGS TO OVERSPREAD TERMINAL AREA FROM SW OVERNIGHT...AS COLD WRAP ARND AIR ADVECTS INTO RGN. LEADING EDGE OF THESE LWR CIGS NOW ADVANCING ACRS MS RVR FROM ERN MO/IA AND SHOULD OVERSPREAD TERMINALS BY 04 OR 05Z. COLD/DRY ADVECTION IN LLVLS SHOULD KEEP VIS UNRESTRICTED THRU MOST OF PERIOD XCP AGN IN VCTY OF SHWRS THIS EVENING. WRAP ARND STRATO CU DECK TO RMN IN PLACE THRU MIDDAY MON BEFORE WX SYS MOVES FAR ENUF E OF AREA TO ALLOW FOR CLRG TO TAKE PLACE BY END OF FCST PERIOD.

OTHER PROBLEM WILL BE WINDS. MODEST SWLY FLOW IN 10-15 KT RANGE THIS EVENING WILL INCRS TO 15G25KT AS COLD AIR ARRIVES ARND 06Z. ELEVATED WIND SPEEDS TO CONT THRU MON MRNG WITH GRDL WDSHFT TO WNW AFT 12Z. WINDS TO DMNSH MID-LATE AFTN MON AS COLD ADVECTION RELAXES.

MERZLOCK

&&

.LOT WATCHES/WARNINGS/ADVISORIES... .IL...NONE. .IN...NONE. .LM...SCA IL WATERS TO GYY THRU 00Z TUESDAY. SCA GYY TO MICHIGAN CITY THRU 06Z TUESDAY.

&&

$$

.DISCUSSION FOR AFTERNOON GRIDS/ZONES...

248 PM CST

UPR LOW CENTERED OVR NRN MO THIS AFTN...WITH STRONG S/WV ASSOCIATED WITH 130KT JET STRK LIFTING NORTHEAST ACROSS MID MS/LWR OH VLYS. DRY SLOT OVR MUCH OF FCST AREA SINCE THIS MORNING STARTING TO SHOW SIGNS OF CONVECTIVE DVLPMNT...WITH SCT RW/TRW BEGINNING TO DVLP BENEATH DIVERGENT LEFT EXIT REGION OF UPPER JET STRK ALONG LOW LEVEL OCCLUDED FRONT AS UPPER LVL FORCING INCRSG WITH APPRCH OF S/WV. RECENT ACARS AND FCST SOUNDINGS AS WELL AS SPC/RUC MESOANALYSIS GRAPHICS INDICATE CAPE VALUES MARGINAL...THOUGH GIVEN STRENGTH OF UPPER FORCING AND LOW LEVEL CONVERGENCE VCNTY OCCLUSION EXPECT SCT RW/TRW TO CONTINUE NEXT FEW HOURS AS S/WV CONTINUES TO APPRCH. MAIN UPPER LOW CENTER LIFTS NORTHEAST ACROSS FCST AREA THIS EVENING...THOUGH SECONDARY VORT MAXIMA WRAPPING AROUND BACK SIDE RESULTS IN LINGERING UPPER TROUGHINESS AND EXTENDED PERIOD OF WEAK MID/UPR LVL FORCING INDICATED BY Q CONVERGENCE FIELDS. THIS S/WV TROUGH AXIS FINALLY MOVES ACROSS FCST AREA MONDAY MORNING...THUS EXPECT SOME LINGERING CHC FOR LIGHT SHOWERS OVRNGT HOURS INTO MONDAY MORNING.

LOW LEVEL COLD ADVCTN TNGT RESULTS IN THICKNESS VALUES FALLING ESPECIALLY AFTR MDNGT...WITH 1000-850 HPA BELOW 1300 METERS AND 850-700 HPA DOWN TO 1520-1530 METERS BY 12Z MON. FCST SOUNDINGS AND TSECTS INDICATE MOIST LAYER FAIRLY SHALLOW BY THAT TIME HOWEVER...WITH CLOUD TOP TEMPS GENERALLY WARMER THAN -10C THAT WOULD NOT SUPPORT SIG ICE CRYSTAL NUCLEATION. HOWEVER...GIVEN PROLONGED FORCING WITH SECOND VORT/TROUGH AND POTENTIAL FOR DEEPER CLOUD LAYER OR SEEDING FROM COLDER HIGHER CLOUD LAYER...WILL MENTION LIGHT RA/SN AFTER MDNT INTO MON MRNG. UPPER TROUGH AXIS THEN SHIFTS EAST OF FCST AREA BY AFTN...WITH MODEL TSECTS AND DIV-Q/OMEGA FIELDS SUGGESTING FAIRLY STRONG DEEP LAYER SUBSIDENCE DVLPG. THUS WILL GO DRY FOR MON AFTN WITH CLRG SKIES BY EVENING AS SFC HIGH PRESSURE BUILDS ACROSS MID MS/OH VLYS.

MID WEEK APPEARS DRY AND CONTINUED MILD AS ANOTHER UPPER TROUGH CUTS OFF/CLOSES OFF OVER THE SOUTHWEST...AND NORTHERN BRANCH OF JET BECOMES MORE ZONAL. GFS/NAM SIMILAR WITH NRN STRM S/WV MOVG THROUGH THE UPPER MIDWEST TUES/TUES NGT...THOUGH WITH DRY LOW LEVELS AND SFC RIDGE AXIS BLOCKING OFF MOISTURE RETURN FROM THE GULF EXPECT NO MORE THAN SOME MID/HIGH CLOUDS WITH THIS FEATURE. SOUTHWESTERN UPPER TROUGH KICKS OUT LATER IN THE WEEK...WITH GLOBAL MODELS DVLPG BROAD TROUGH IN SOMEWHAT PHASED NRN/SRN STREAMS BY FRI/SAT. BEST PCPN CHANCES INITIALLY TO OUR SOUTH AND OFF TO OUR NORTH...UNTIL MAIN UPPER TROUGH APPRCHS FRI NGT AND SATURDAY. WILL CARRY CHC POPS FOR INITIALLY RA FRI NGT AND THEN RA/SN SAT AS COLDER AIR MOVES IN BEHIND SFC COLD FRONT.

TEMPS THROUGH THE PERIOD AGAIN TO REMAIN FAIRLY MILD. MAV GUIDANCE NUMBERS GENERALLY PREFERRED EARLY ON...THEN GENERALLY AT OR A LITTLE ABOVE THE HPC/MEX NUMBERS MID WEEK AS LLVL SW FLOW DVLPS.

RATZER

&&

.AVIATION DISCUSSION FOR 00Z TAFS...

MAIN PROBLEM AGAIN THIS EVENING WILL BE VARIABLE CIGS. AREA IS IN DRY SLOT ASSD WITH DEEPENING LOW PRES CENTER LOCATED OVR CNTRL WI JUST ESE OF EAU AT 00Z. COLD POOL ALF ASSD WITH UPPER LVLS OF THIS SYS WILL BE MOVG ACRS IL TNGT. THIS AREA HAS HELPED DESTABILIZE AMS ENUF TO TRIGGER A BAND OF SHALLOW TOPPED CONVECTION OVR CNTRL IL. TSTMS NOW EXTENDING FROM E OF BMI-DNV WILL CONTINUE LIFTING NEWD ACRS EXTRM NERN IL/NWRN IND THRU 02Z. EXPECT TSTMS TO STAY S OF A PNT-IKK-GYY LN...WITH JUST SCT SHWRS TO N OF THIS LN. CIGS GENLY VFR THRU MUCH OF THIS EVENING XCP IN SHRWS WHERE BKN CIGS IN 2-3 TSD FT RANGE CAN BE EXPECTED. MORE SLD LOW RANGE MVFR CIGS TO OVERSPREAD TERMINAL AREA FROM SW OVERNIGHT...AS COLD WRAP ARND AIR ADVECTS INTO RGN. LEADING EDGE OF THESE LWR CIGS NOW ADVANCING ACRS MS RVR FROM ERN MO/IA AND SHOULD OVERSPREAD TERMINALS BY 04 OR 05Z. COLD/DRY ADVECTION IN LLVLS SHOULD KEEP VIS UNRESTRICTED THRU MOST OF PERIOD XCP AGN IN VCTY OF SHWRS THIS EVENING. WRAP ARND STRATO CU DECK TO RMN IN PLACE THRU MIDDAY MON BEFORE WX SYS MOVES FAR ENUF E OF AREA TO ALLOW FOR CLRG TO TAKE PLACE BY END OF FCST PERIOD.

OTHER PROBLEM WILL BE WINDS. MODEST SWLY FLOW IN 10-15 KT RANGE THIS EVENING WILL INCRS TO 15G25KT AS COLD AIR ARRIVES ARND 06Z. ELEVATED WIND SPEEDS TO CONT THRU MON MRNG WITH GRDL WDSHFT TO WNW AFT 12Z. WINDS TO DMNSH MID-LATE AFTN MON AS COLD ADVECTION RELAXES.

MERZLOCK

&&

.LOT WATCHES/WARNINGS/ADVISORIES... .IL...NONE. .IN...NONE. .LM...SCA IL WATERS TO GYY THRU 00Z TUESDAY. SCA GYY TO MICHIGAN CITY THRU 06Z TUESDAY.

&&

$$

.DISCUSSION...

TODAY:

LATEST WATER VAPOR LOOP SHOWING MULTIPLE VORTICITY LOBES ROTATING AROUND SOUTHWEST US UPPER LOW. 30-35KFT ACARS WINDS PERIODICALLY SHOWING 100KTS WINDS FROM EAST SOUTHEAST INTO SOUTHEAST COLORADO. SO IT APPEARS THAT THE LOW WILL STILL BE SLOW TO MOVE...MOST LIKELY SIMILAR TO 00Z EUROPEAN CENTRE FOR MEDIUM RANGE WEATHER FORECASTS MODEL. FOR GRID PURPOSES...00 UTC NORTH AMERICAN MODEL WAS CLOSEST TO THIS...BUT IT WAS A BIT TOO FAR NORTH WITH SURFACE LOW.

THE QUASI-STATIONARY FRONT HAS SLIPPED A BIT EAST FROM THIS TIME YESTERDAY AND SUSPECT IT WILL DRIFT A FEW MORE MILES EAST TODAY BEFORE SURFACE LOW MOVES ACROSS THE FORECAST AREA. OBSERVATIONS AND FORECAST SOUNDINGS SUGGEST WARM LAYER ALOFT WILL KEEP PRECIPITATION IN FORM OF RAIN ACROSS FAR NORTHWEST SECTIONS... ALTHOUGH COULD GET CLOSE TO -FZRA -FZDZ EARLY THIS MORNING.

DRIER AIR ALREADY EVIDENT IN ERODING LARGE AREA OF PRECIPITATION IN SOUTHEAST KS. HOWEVER WITH SECOND BAND ACROSS SOUTHWEST OK IN RADAR/INFRARED SATELLITE LOOPS...MAY STILL SEE SCATTERED PRECIPITATION WELL INTO THE DAY. DO ANTICIPATE CHANCES WILL BE ON THE WANE DURING THE AFTERNOON EXCEPT IN FAR NORTHWEST SECTIONS.

WAS SOME CONCERN FOR STRONG-SEVERE THUNDERSTORM POTENTIAL ALONG PSEUDO DRYLINE THIS AFTERNOON. AT THIS TIME...FORECAST NORTH AMERICAN MODEL SOUNDINGS SUGGEST ATMOSPHERE WILL LIKELY REMAIN CAPPED TO SURFACE/NEAR SURFACE BASED PARCELS WITH NOTORIOUSLY SPURIOUS MODEL COOLING ERODING CAP IN THE AFTERNOON. WINDS ALSO BACK AROUND 700MB LEADING TO LESS THAN OPTIMAL HODOGRAPH. WILL KEEP THUNDERSTORMS MENTIONED GIVEN SOME ELEVATED CONVECTIVE AVAILABLE POTENTIAL ENERGY. DAY SHIFT WILL NEED TO WATCH THIS CLOSELY...AS STRONG DYNAMICS/WIND COULD RESULT IN FAIRLY STRONG STORMS EVEN WITH MARGINAL CONVECTIVE AVAILABLE POTENTIAL ENERGY DEPENDING ON VERIFYING THERMODYNAMIC PROFILES.

TONIGHT-SUN:

APPEARS THAT COLDER AIR WILL SLOWLY SAG EASTWARD TONIGHT AND THEN SWEEP RAPIDLY ACROSS THE REST OF THE AREA ON SUN. OF PARTICULAR CONCERN IS ABSENCE OF ICE CRYSTALS IN SOUNDINGS FOR TONIGHT AND SUSPECT PRECIPITATION MAY BE DRIZZLE/FZDZ IN NORTHWEST SECTIONS. CONSIDERABLE UNCERTAINTY IN DETAILS OF WHEN AND HOW MUCH...SO HELD OFF ON ADVISORY AT THIS TIME...BUT DAY SHIFT MAY NEED TO JUMP ON THIS BEFORE THE AFTERNOON PACKAGE GOES OUT. 0000 UTC EUROPEAN CENTRE FOR MEDIUM RANGE WEATHER FORECASTS MODEL POINTING TO DECENT DYNAMICS IN SUPPORT OF LIGHT SNOW ON SUN ON BACK SIDE OF LOW.

MON-FRI:

ONLY MINOR TWEAKS FOR CLIMATOLOGY AND TO ADJUST WINDS ON MON NIGHT-TUES. 0000 UTC GLOBAL FORECAST SYSTEM MODEL APPEARS TO BE GROSSLY IN ERROR WITH SURFACE HIGH PRESSURE IN THE VICINITY OF AMA AT 0000 UTC WED...GIVE UPPER PATTERN. THE 0000 UTC EUROPEAN CENTRE FOR MEDIUM RANGE WEATHER FORECASTS MODEL APPEARS TO BE MUCH MORE REASONABLE GIVEN LOWERING PRESSURE IN LEE OF THE ROCKIES. MODIFIED WINDS TO ACCOUNT FOR THIS MORE REALISTIC PATTERN. -HOWERTON

&&

.PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 57 36 38 26 / 80 30 40 10 HUTCHINSON 48 32 34 22 / 80 40 50 20 NEWTON 56 33 35 24 / 90 40 50 20 ELDORADO 60 35 38 26 / 90 30 40 10 WINFIELD-KWLD 60 35 39 27 / 70 20 30 10 RUSSELL 36 26 31 17 / 100 60 60 20 GREAT BEND 36 27 31 17 / 90 60 60 20 SALINA 46 33 35 23 / 100 50 60 20 MCPHERSON 49 31 34 23 / 90 50 60 20 COFFEYVILLE 62 40 47 30 / 80 20 20 10 CHANUTE 61 39 46 28 / 90 40 30 10 IOLA 60 39 46 28 / 90 40 40 20 PARSONS-KPPF 62 40 46 28 / 80 30 30 10

&&

.ICT WATCHES/WARNINGS/ADVISORIES... NONE. &&

$$

.DISCUSSION...

TODAY:

LATEST WATER VAPOR LOOP SHOWING MULTIPLE VORTICITY LOBES ROTATING AROUND UPPER LOW. 30-35KFT ACARS WINDS PERIODICALLY SHOWING 100KTS WINDS FROM EAST SOUTHEAST INTO SOUTHEAST COLORADO. SO IT APPEARS THAT THE LOW WILL STILL BE SLOW TO MOVE MOST LIKELY SIMILAR TO EUROPEAN CENTRE FOR MEDIUM RANGE WEATHER FORECASTS MODEL. FOR GRID PURPOSES...00 UTC NORTH AMERICAN MODEL WAS CLOSEST TO THIS...BUT IT WAS A BIT TOO FAR NORTH WITH SURFACE LOW.

THE QUASISTATIONARY FRONT HAS SLIPPED A BIT EAST FROM THIS TIME YESTERDAY AND SUSPECT IT WILL DRIFT A FEW MORE MILES EAST TODAY BEFORE SURFACE LOW MOVES ACROSS THE FORECAST AREA. OBSERVATIONS AND FORECAST SOUNDINGS SUGGEST WARM LAYER ALOFT WILL KEEP PRECIPITATION IN FORM OF RAIN ACROSS FAR NORTHWEST SECTIONS... ALTHOUGH COULD GET CLOSE TO -FZRA -FZDZ EARLY THIS MORNING.

DRIER AIR ALREADY EVIDENT IN ERODING AREA OF PRECIPITATION IN SOUTHEAST KS. HOWEVER WITH SECOND BAND ACROSS SOUTHWEST OK IN RADAR/INFRARED SATELLITE LOOPS...MAY STILL SEE SCATTERED PRECIPITATION THROUGHOUT THE DAY. DO ANTICIPATE CHANCES WILL BE ON THE WANE DURING THE AFTERNOON XCPT IN FAR NORTHWEST SECTIONS.

WAS SOME CONCERN FOR STRONG-SEVERE THUNDERSTORM POTENTIAL ALONG PSEUDO DRYLN THIS AFTERNOON. AT THIS TIME...FORECAST NORTH AMERICAN MODEL SOUNDINGS WILL LIKELY REMAIN CAPPED TO SURFACE/NEAR SURFACE BASED PARCELS WITH NOTORIOUSLY SPURIOUS MODEL COOLING IN AFTERNOON. WINDS ALSO BACK AROUND 700MB LEADING TO LESS THAN OPTIMAL HODOGRAPH. WILL KEEP THUNDERSTORMS MENTIONED GIVEN SOME ELEVATED CONVECTIVE AVAILABLE POTENTIAL ENERGY. DAY SHIFT WILL NEED TO WATCH THIS CLOSELY...AS STRONG DYNAMICS/WIND COULD RESULT IN FAIRLY STRONG STORMS EVEN WITH MARGINAL CONVECTIVE AVAILABLE POTENTIAL ENERGY.

TONIGHT-SUN:

APPEARS THAT COLDER AIR WILL SLOWELY SAG EWD TONIGHT AND THEN SWEEP RAPIDLY ACROSS THE REST OF THE AREA ON SUN. OF PARTICULAR CONCERN IS ABSENCE OF ICE CRYSTALS IN SOUNDINGS FOR TONIGHT AND SUSPECT PRECIPITATION MAY BE DRIZZLE/FZDZ IN NORTHWEST SECTIONS. CONSIDERABLE UNCERTAINTY IN DETAILS OF WHEN AND HOW MUCH......SO HELD OFF ON ADVISORY AT THIS TIME...BUT DAY SHIFT NEED TO JUMP ON THIS BEFORE THE AFTERNOON PACKAGE GOES OUT. 0000 UTC EUROPEAN CENTRE FOR MEDIUM RANGE WEATHER FORECASTS MODEL POINTING TO DECENT DYNAMICS IN SUPPORT OF LIGHT SNOW ON SUN ON BACK SIDE OF LOW.

MON-FRI:

ONLY MINOR TWEAKS FOR CLIMATOLOGY AND TO ADJUST WINDS ON MON NIGHT-TUES. 0000 UTC GLOBAL FORECAST SYSTEM MODEL APPEARS TO BE GROSSLY IN ERROR WITH SURFACE HIGH PRESSURE IN THE VICINITY OF AMA AT 0000 UTC WED...GIVE UPPER PATTERN. THE 0000 UTC EUROPEAN CENTRE FOR MEDIUM RANGE WEATHER FORECASTS MODEL APPEARS TO BE MUCH MORE REASONABLE GIVEN LOWERING PRESSURE IN LEE OF THE ROCKIES. MODIFIED WINDS TO ACCOUNT FOR THIS MORE RATIONALE PATTERN. -HOWERTON

&&

.PRELIMINARY POINT TEMPS/POPS... WILL BE ISSUED SHORTLY. &&

.ICT WATCHES/WARNINGS/ADVISORIES... NONE. &&

$$

.UPDATE...EARLIER CONCERNS ABOUT CLOUD COVER APPEAR TO BE COMING TO PASS. ALTHOUGH MOIST LAYER CONTINUES TO BECOME MORE SHALLOW WITH TIME (DOWN TO AROUND 900MB PER RECENT AIRCRAFT SOUNDING OUT OF PLN)...VISIBLE IMAGERY SHOWS CLOUD COVER SHOWING NO HINTS OF THINNING OUT. EARLIER THIN SPOTS ARE FILLING BACK IN...AND LOW CLOUDS HAVE PUSHED INTO AREAS THAT HAD BRIEFLY CLEARED OUT (GLADWIN/ARENAC COUNTIES). FOG ALSO CONTINUES TO PERSIST ACROSS THE HIGHER TERRAIN. SOME CLEARING DEVELOPING UP AROUND WHITEFISH POINT...SO WILL CONTINUE WITH THE BECOMING PARTLY SUNNY IDEA ACROSS EASTERN UPPER...BUT FOR THE TIME BEING WILL HOLD THE CLOUDS IN ACROSS NORTHERN LOWER THROUGH TONIGHT AND RE-EVALUATE WITH LATE AFTERNOON FORECAST ISSUANCE.

PREVIOUS UPDATED (1031 AM EST)...12Z APX/GRB SOUNDINGS BOTH SHOWING SATURATED CONDITIONS BELOW 650-700MB...WITH LOW CLOUDS AND FOG OVER PRETTY MUCH THE ENTIRE FORECAST AREA. SOME HOLES IN THE LOW CLOUDS OVER LAKES MICHIGAN/HURON...PROBABLY DUE TO SOME SHALLOW MIXING WITH 925MB TEMPERATURES AROUND -1C. NORTHERN BRANCH SHORT WAVE TROUGH PASSING BY TO THE EAST OF THE FORECAST AREA PER WATER VAPOR IMAGERY...WITH DRYING/SUBSIDENCE NOTED SPREADING SOUTHWARD IN ITS WAKE THROUGH THE UPPER PENINSULA/STRAITS. AIRCRAFT SOUNDING OUT OF MQT INDICATING DRIER AIR AT 700MB (DEW POINT DEPRESSION AROUND 10C) WITH MOIST LAYER UP TO 850MB. BAND OF LIGHT RAIN/DRIZZLE ALONG TROUGH AXIS MOVING OUT OF THE FORECAST AREA TO THE SOUTH. LOW/MID LEVEL RIDGE AXIS EXTENDING NORTHWEST-SOUTHEAST FROM NORTHERN MN ACROSS THE OHIO VALLEY.

PROBLEM FOR THE AFTERNOON WILL BE EVOLUTION OF CLOUD COVER. RIDGING UPSTREAM WILL CONTINUE TO PROVIDE SUBSIDENCE/DRY AIR ADVECTION... WHICH WILL GRADUALLY ERODE DEPTH OF MOIST LAYER OVER NORTHERN MI. QUESTION IS WHETHER MOIST LAYER WILL BE ERODED ENOUGH TO ALLOW LOW SUN ANGLE TO WORK ON REMAINING LOW ST DECK. DOESN`T APPEAR TO BE MUCH IN THE WAY OF LOW CLOUD CLOSER TO SAGINAW BAY...SO AREAS AROUND GLADWIN/ARENAC COUNTIES SHOULD BREAK OUT INTO SUN ONCE LAST OF THE MID CLOUD EXITS BY MIDDAY. OVER THE REMAINDER OF THE AREA WILL PROBABLY BE A SLOW CLEARING PROCESS...LOOKS LIKE SOUTHERN PORTIONS OF THE FORECAST AREA SOUTH OF M-72 WILL LIKELY ERODE FIRST. CLOUDS WILL HANG TOUGH INTO EARLY AFTERNOON ACROSS EASTERN UPPER/FAR NORTHERN LOWER...BUT WILL CONTINUE TO ALLOW FOR THINNING CLOUDS AS THE DAY WEARS ON.

JPB

&&

.PREV DISCUSSION...ISSUED 420 AM EST SAT DEC 30.

SPLIT FLOW PATTERN ALOFT CONTINUES ACROSS NOAM... WITH MAIN FEATURE BEING CUT-OFF UPPER LOW OVER NEW MEXICO (REMAINING DETACHED FROM MAIN BRANCH OF WESTERLIES OVER SRN CANADA). MEANWHILE...IMPULSE DROPPING ESEWD THROUGH CONFLUENT MID LEVEL FLOW OVER THE UPPER MIDWEST WAS GENERATING LIGHT PRECIP THIS MORNING ACROSS PARTS OF MI/WI. FORECAST CONCERNS FOR NRN MI INCLUDE IMPACT OF AFOREMENTIONED SHORT WAVE TODAY...AS WELL AS MOVEMENT/IMPACT OF UPPER LOW OVER THE SW U.S. FOR SUNDAY AND MONDAY.

TODAY AND TONIGHT...IR/WV LOOP SHOWS COOLING/ENHANCED CLOUDS PUSHING ESE ACROSS THE NRN GREAT LAKES...ASSOCIATED WITH MID LEVEL CONFLUENCE/DEFORMATION...AND RESULTING F-GEN FORCING. CONSISTENT WITH LOW LEVEL MOISTURE ON MODEL SOUNDINGS...SURFACE OBS REVEAL PLENTY OF LOW CLOUDS AND FOG THIS MORNING. MODEL SOUNDINGS ALSO SUGGEST THAT MID LEVEL MOISTURE SUFFICIENT FOR ICE PROCESSES (AND NON-DRIZZLE PRECIP) EARLY THIS MORNING WILL BE CONFINED TO PRIMARILY ERN UPPER. EXPECT LIGHT SNOW TO END NEXT 1-2 HRS OVER ERN UPPER... WITH ONLY PATCHY FOG/DRIZZLE/FLURRIES EXPECTED ACROSS NRN LOWER. IN WAKE OF SHORT WAVE...SHARP SUBSIDENCE AND DRYING IS EXPECTED (BOTH NAM/GFS DROP 850 MB DEW POINTS TO AROUND -12C BY THIS AFTERNOON). DRYING...COUPLED WITH EXPECTED DEEP RIDGING...SUPPORTS TREND TOWARD PARTLY SUNNY SKIES THIS AFTERNOON. EXPECT PARTLY CLOUDY SKIES TO CONTINUE TONIGHT...ALONG WITH PATCHY FOG.

SUNDAY...DEEP LAYER RIDGING BEGINS TO DRIFT E...AS UPPER LOW OVER THE SW U.S. LIFTS NEWD. MODELS HAVE TRENDED A BIT FASTER IN THIS REGARD...AND GFS REMAINS FASTER THAN NAM. CONSIDERING THE JET (KICKER) ENERGY POUNDING INTO THE PACIFIC NW AND OVERALL MODEL TRENDS...WILL LEAN TOWARD FASTER GFS SOLUTION. SURFACE LOW IS EXPECTED TO MOVE FROM OK TODAY...NE TO ERN IA BY LATE SUN. WITH STRENGTHENING ISENTROPIC ASCENT...850-500 MB RH INCREASING TO >80%...AND APPROACHING 250 MB JET SUPPORT...RAIN WILL GRADUALLY OVERSPREAD REGION FROM SW TO NE DURING THE DAY. TEMPS ALOFT EXPECTED TO KEEP PRECIP ALL RAIN...AS HIGHS REACH 35 TO 40.

NEW YEARS EVE AND NEW YEARS DAY (SUNDAY NIGHT AND MONDAY)...PRECIP TYPE GETS A BIT MORE COMPLEX...AS STRONGER ASCENT OVERSPREADS REGION...AND STRENGTHENING EAST FLOW AT SURFACE BRINGS POTENTIALLY COOLER AIR IN AT LOW LEVELS. BASED ON MODEL SOUNDINGS AND EXPECTED SURFACE TEMPS...WILL OPT FOR A MIX OF SNOW AND FREEZING RAIN OVER ERN UPPER...RAIN OR FREEZING RAIN OVER INTERIORS PARTS OF NE LOWER...WITH ONLY RAIN ELSEWHERE. WILL RETAIN A GENERAL MIX OF RAIN/SNOW FOR NEW YEARS DAY AREAWIDE...GIVEN MODEL/THERMODYNAMIC UNCERTAINTIES. IF GFS SOLUTION PANS OUT...A FEW INCHES OF WET SNOW WILL BE POSSIBLE OVER ERN UPPER MI.

TUESDAY AND WEDNESDAY...ASSUMING FASTER GFS TIMING...STORM SYSTEM IS EXPECTED TO GET CAUGHT UP IN WESTERLIES AND PASS THROUGH SRN ONTARIO/QUEBEC BY MON NIGHT. RELATIVELY MILD PACIFIC RIDGE WILL EXPAND ACROSS THE CENTRAL U.S...AS COLD AIR REMAINS BOTTLED UP WELL NORTH OF REGION. AS SUCH...EXPECT DRY AND CONTINUED ABOVE NORMAL TEMPS TUE AND WED WITH HIGHS IN THE 30S.

SMITH

&&

.APX...WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

.UPDATE...12Z APX/GRB SOUNDINGS BOTH SHOWING SATURATED CONDITIONS BELOW 650-700MB...WITH LOW CLOUDS AND FOG OVER PRETTY MUCH THE ENTIRE FORECAST AREA. SOME HOLES IN THE LOW CLOUDS OVER LAKES MICHIGAN/HURON...PROBABLY DUE TO SOME SHALLOW MIXING WITH 925MB TEMPERATURES AROUND -1C. NORTHERN BRANCH SHORT WAVE TROUGH PASSING BY TO THE EAST OF THE FORECAST AREA PER WATER VAPOR IMAGERY...WITH DRYING/SUBSIDENCE NOTED SPREADING SOUTHWARD IN ITS WAKE THROUGH THE UPPER PENINSULA/STRAITS. AIRCRAFT SOUNDING OUT OF MQT INDICATING DRIER AIR AT 700MB (DEW POINT DEPRESSION AROUND 10C) WITH MOIST LAYER UP TO 850MB. BAND OF LIGHT RAIN/DRIZZLE ALONG TROUGH AXIS MOVING OUT OF THE FORECAST AREA TO THE SOUTH. LOW/MID LEVEL RIDGE AXIS EXTENDING NORTHWEST-SOUTHEAST FROM NORTHERN MN ACROSS THE OHIO VALLEY.

PROBLEM FOR THE AFTERNOON WILL BE EVOLUTION OF CLOUD COVER. RIDGING UPSTREAM WILL CONTINUE TO PROVIDE SUBSIDENCE/DRY AIR ADVECTION... WHICH WILL GRADUALLY ERODE DEPTH OF MOIST LAYER OVER NORTHERN MI. QUESTION IS WHETHER MOIST LAYER WILL BE ERODED ENOUGH TO ALLOW LOW SUN ANGLE TO WORK ON REMAINING LOW ST DECK. DOESN`T APPEAR TO BE MUCH IN THE WAY OF LOW CLOUD CLOSER TO SAGINAW BAY...SO AREAS AROUND GLADWIN/ARENAC COUNTIES SHOULD BREAK OUT INTO SUN ONCE LAST OF THE MID CLOUD EXITS BY MIDDAY. OVER THE REMAINDER OF THE AREA WILL PROBABLY BE A SLOW CLEARING PROCESS...LOOKS LIKE SOUTHERN PORTIONS OF THE FORECAST AREA SOUTH OF M-72 WILL LIKELY ERODE FIRST. CLOUDS WILL HANG TOUGH INTO EARLY AFTERNOON ACROSS EASTERN UPPER/FAR NORTHERN LOWER...BUT WILL CONTINUE TO ALLOW FOR THINNING CLOUDS AS THE DAY WEARS ON.

JPB

&&

.PREV DISCUSSION...ISSUED 420 AM EST SAT DEC 30.

SPLIT FLOW PATTERN ALOFT CONTINUES ACROSS NOAM... WITH MAIN FEATURE BEING CUT-OFF UPPER LOW OVER NEW MEXICO (REMAINING DETACHED FROM MAIN BRANCH OF WESTERLIES OVER SRN CANADA). MEANWHILE...IMPULSE DROPPING ESEWD THROUGH CONFLUENT MID LEVEL FLOW OVER THE UPPER MIDWEST WAS GENERATING LIGHT PRECIP THIS MORNING ACROSS PARTS OF MI/WI. FORECAST CONCERNS FOR NRN MI INCLUDE IMPACT OF AFOREMENTIONED SHORT WAVE TODAY...AS WELL AS MOVEMENT/IMPACT OF UPPER LOW OVER THE SW U.S. FOR SUNDAY AND MONDAY.

TODAY AND TONIGHT...IR/WV LOOP SHOWS COOLING/ENHANCED CLOUDS PUSHING ESE ACROSS THE NRN GREAT LAKES...ASSOCIATED WITH MID LEVEL CONFLUENCE/DEFORMATION...AND RESULTING F-GEN FORCING. CONSISTENT WITH LOW LEVEL MOISTURE ON MODEL SOUNDINGS...SURFACE OBS REVEAL PLENTY OF LOW CLOUDS AND FOG THIS MORNING. MODEL SOUNDINGS ALSO SUGGEST THAT MID LEVEL MOISTURE SUFFICIENT FOR ICE PROCESSES (AND NON-DRIZZLE PRECIP) EARLY THIS MORNING WILL BE CONFINED TO PRIMARILY ERN UPPER. EXPECT LIGHT SNOW TO END NEXT 1-2 HRS OVER ERN UPPER... WITH ONLY PATCHY FOG/DRIZZLE/FLURRIES EXPECTED ACROSS NRN LOWER. IN WAKE OF SHORT WAVE...SHARP SUBSIDENCE AND DRYING IS EXPECTED (BOTH NAM/GFS DROP 850 MB DEW POINTS TO AROUND -12C BY THIS AFTERNOON). DRYING...COUPLED WITH EXPECTED DEEP RIDGING...SUPPORTS TREND TOWARD PARTLY SUNNY SKIES THIS AFTERNOON. EXPECT PARTLY CLOUDY SKIES TO CONTINUE TONIGHT...ALONG WITH PATCHY FOG.

SUNDAY...DEEP LAYER RIDGING BEGINS TO DRIFT E...AS UPPER LOW OVER THE SW U.S. LIFTS NEWD. MODELS HAVE TRENDED A BIT FASTER IN THIS REGARD...AND GFS REMAINS FASTER THAN NAM. CONSIDERING THE JET (KICKER) ENERGY POUNDING INTO THE PACIFIC NW AND OVERALL MODEL TRENDS...WILL LEAN TOWARD FASTER GFS SOLUTION. SURFACE LOW IS EXPECTED TO MOVE FROM OK TODAY...NE TO ERN IA BY LATE SUN. WITH STRENGTHENING ISENTROPIC ASCENT...850-500 MB RH INCREASING TO >80%...AND APPROACHING 250 MB JET SUPPORT...RAIN WILL GRADUALLY OVERSPREAD REGION FROM SW TO NE DURING THE DAY. TEMPS ALOFT EXPECTED TO KEEP PRECIP ALL RAIN...AS HIGHS REACH 35 TO 40.

NEW YEARS EVE AND NEW YEARS DAY (SUNDAY NIGHT AND MONDAY)...PRECIP TYPE GETS A BIT MORE COMPLEX...AS STRONGER ASCENT OVERSPREADS REGION...AND STRENGTHENING EAST FLOW AT SURFACE BRINGS POTENTIALLY COOLER AIR IN AT LOW LEVELS. BASED ON MODEL SOUNDINGS AND EXPECTED SURFACE TEMPS...WILL OPT FOR A MIX OF SNOW AND FREEZING RAIN OVER ERN UPPER...RAIN OR FREEZING RAIN OVER INTERIORS PARTS OF NE LOWER...WITH ONLY RAIN ELSEWHERE. WILL RETAIN A GENERAL MIX OF RAIN/SNOW FOR NEW YEARS DAY AREAWIDE...GIVEN MODEL/THERMODYNAMIC UNCERTAINTIES. IF GFS SOLUTION PANS OUT...A FEW INCHES OF WET SNOW WILL BE POSSIBLE OVER ERN UPPER MI.

TUESDAY AND WEDNESDAY...ASSUMING FASTER GFS TIMING...STORM SYSTEM IS EXPECTED TO GET CAUGHT UP IN WESTERLIES AND PASS THROUGH SRN ONTARIO/QUEBEC BY MON NIGHT. RELATIVELY MILD PACIFIC RIDGE WILL EXPAND ACROSS THE CENTRAL U.S...AS COLD AIR REMAINS BOTTLED UP WELL NORTH OF REGION. AS SUCH...EXPECT DRY AND CONTINUED ABOVE NORMAL TEMPS TUE AND WED WITH HIGHS IN THE 30S.

SMITH

&&

.APX...WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

.DISCUSSION... MAIN FCST CONCERNS ARE PCPN CHANCES/TYPE/AMOUNT SUN INTO MON.

WV IMAGERY AND RUC ANALYSIS INDICATED SPLIT MID/UPPER LEVEL FLOW ACROSS NOAM. A VIGOROUS CLOSED MID/UPPER LEVEL LOW NEAR THE TX PANHANDLE WAS THE DOMINANT ACTIVE WEATHER FEATURE IN THE CONUS. ANOTHER MOISTURE STARVED CUTOFF LOW WAS LOCATED OVER THE NORTHERN HIGH PLAINS. A DEPARTING AREA OF COLDER TOPS FROM E LK SUPERIOR TO QUEBEC...PER IR LOOP...WAS ASSOCIATED WITH A NRN STREAM SHRTWV FROM NEAR JAMES BAY TO WRN LK SUPERIOR. RADAR INDICATED SOME -SN OR FLURRIES INTO E UPR MI ASSOCIATED WITH THIS FEATURE. PCPN WAS ALSO AIDED BY ANOTHER BAND OF 700-500 MB FGEN AND UPPER LEVEL DIV IN RIGHT ENTRANCE OF A JET STREAK TO THE NE. AT THE SFC...HIGH PRES EXTENDED FROM SRN MANITOBA THROUGH WRN ONTARIO AND NRN LK SUPERIOR TO NEW ENGLAND. LOW PRES WAS LOCATED OVER SW OK WITH A FRONT TO THE NE THROUGH NE KS TO NRN IL. IR IMAGERY AND SFC OBS SHOWED AN EXTENSIVE AREA OF LOW CLOUDS OVER THE REGION WITH CLEARING LINE WELL TO THE NW OVER SRN MANITOBA. 05Z TAMDAR SNDGS INDICATED MOISTURE TO NEAR 700 MB OVER FROM CYQT/KRHI THINNING OUT FARTHER W OVER MN.

TODAY...ANY LINGERING LIGHT SNOW OR FLURRIES SHOULD DEPART E UPR MI EARLY THIS MORNING AS THE SUPPORTING DYNAMICS QUICKLY SLIDE TO THE EAST. EVEN THOUGH THE NAM/RUC/GFS SUGGEST THAT THE CLOUDS WILL DIMINISH AS THE RDG CONTINUES TO BUILD INTO THE AREA...EXPECT CLEARING MAY BE DELAYED SINCE THE MDLS WERE ALREADY TOO AGGRESSIVE IN BRINGING CLEARING TO THE SE AND THAT RELATIVELY WEAK ADVECTION AND LOW SUN ANGLE WILL NOT BE ENOUGH TO OVERCOME AMOUNT OF MOISTURE BLO THE 925 MB INVERSION. LATER OR LIMITED CLEARING SHOULD LIMIT MAX TEMPS TO VALUES AOB GUIDANCE.

THE FCST WILL GENERALLY LEAN TOWARD THE HPC PREFERRED GFS FOR THE COMPLEX WEATHER SCENARIO THROUGH MON. HOWEVER...THE GFS MAY A BIT FAST BY SUN NIGHT INTO MON WITH THE MID LVL AND SFC LOW...GIVEN THE SLOWER UKMET/ECMWF AND ENSEMBLE MEAN. THE MUCH SLOWER NAM AGAIN WAS MORE OF AN OUTLIER AND WAS DISCOUNTED.

TONIGHT INTO SUN...ANY CLEARING THAT DEVELOPS OVER THE S WILL GIVE WAY TO INCREASING CLOUDS OVERNIGHT. EXPECT ENOUGH DRY AIR TO FILTER INTO THE AREA FOR DECENT RADIATIONAL COOLING WHERE CLOUDS THIN OUT. THIS SHOULD ALLOW TEMPS TO DROP INTO THE MID 20S TO AROUND 30. THE GFS SHOWS AN IMPRESSIVE SURGE OF MOISTURE AND 295K-300K ISENTROPIC LIFT THROUGH WI TO SW UPPER MI BY SUN MORNING ASSOCIATED WITH A LEAD SHORTWAVES EMERGING FROM THE PLAINS LOW. AS IS OFTEN THE CASE...CONVECTION TO THE SOUTH(OVER THE LWR/MID MS VALLEY) MAY INTERCEPT SOME OF THE NORTHBOUND MOISTURE...LIMITING PCPN AMOUNTS FARTHER NORTH OVER UPPER MI. NEVERTHELESS PCPN AMOUNTS OF AROUND A TENTH OF AN INCH ARE EXPECTED DURING THE PERIOD WHERE SFC TEMPS MAY BE AT OR SLIGHTLY BELOW FREEZING. AFTER A BRIEF INITIAL PERIOD OF EVAPORATION COOLING THAT COULD SUPPORT LIGHT SNOW OR SLEET...GFS FCST SNDGS SHOW A WARM ENOUGH 900-700 MB LAYER FOR LIQUID PCPN. GIVEN LOWER PROBABILITY OF QPF AND PROLONGED TEMPS BLO FREEZING WINTER/ICE STORM WATCH WAS NOT ISSUED AT THIS TIME. ALTHOUGH THE GFS FCST SNDGS SHOW ENOUGH COOLING FOR A CHANGEOVER TO SNOW DURING THE AFTERNOON...THE ECMWF/UKMET THERMAL PROFILES SUGGEST THAT TRANSITION TO SNOW WOULD MORE LIKELY OCCUR AFTER THE WARM PASSAGE OF THE INVERTED TROF SUN EVENING.

SUN NIGHT AND MON...THE GFS SUGGESTS THAT THE MOST FAVORABLE 700-500 MB DEFORMATION ZONE FORCING WILL SET UP OVER W UPPER MI. HOWEVER...UNLIKE THE 12/22/06 STORM...THE DRY SLOT IS LESS LIKELY TO WRAP INTO CNTRL UPPER MI. SO...AS THE MID LVL AND SFC LOW SLIDE INTO NRN LWR MI...DEEP MOISTURE AND CYCLONIC FLOW ALONG WITH SOME LAKE CONTRIBUTION (850 MB TEMPS ONLY NEAR -5C) SHOULD SUPPORT AT LEAST MODERATE SNOWFALL AMOUNTS(OVERALL IN THE 4-8 INCH RANGE) OVER THE FAVORED NRLY WIND UPSLOPE LOCATIONS IN THE W HLF OF THE CWA. AGAIN...CONFIDENCE IN SNOWFALL AMOUNTS EXCEEDING WARNING CRITERIA WAS NOT HIGH ENOUGH AT THIS TIME GIVEN UNCERTAINTY WITH RAIN SNOW CHANGEOVER AND LOCATION OF STRONGEST FORCING...FOR WATCH ISSUANCE. A SPECIAL WEATHER STATEMENT IN ADDITION TO THE HWO WILL BE ISSUED TO HIGHLIGHT POTENTIAL IMPACTS ON TRAVEL FROM SUN INTO MON.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...NONE. &&

$$

JLB

.DISCUSSION... RECORD BREAKING WINTER STORM CONTINUES TO PUMMEL PORTIONS OF NORTHERN NEW MEXICO. STORM TOTALS SO FAR ON THE ORDER OF 12-20 INCHES IN AND AROUND THE ABQ AREA WITH 18-26 INCHES IN AND AROUND SANTA FE. SOME PORTIONS OF THE EAST SLOPES OF THE SANGRE DE CRISTOS HAVE RECEIVED MORE THAN 30 INCHES OF SNOW. SNOW RATIOS APPEARED TO PAN OUT WITH 5-10 TO 1 FOR THE FIRST HALF OF THE STORM WITH 15-20 TO 1 FOR THE SECOND HALF. CAN ONLY IMAGINE IF ENTIRE STORM HAD BEEN ABOVE 10 TO 1. THE REAL HAZARD HOWEVER HAS BEEN IN AND AROUND THE CLAYTON AREA WHERE STRONG WIND AND HEAVY SNOW HAS CREATED DRIFTS TOPPING 10 FEET. WILL CONTINUE HEADLINES IN ALL AREAS WITH WRAP AROUND SNOWS AND DROPPED NORTHWEST PLATEAU...WEST CENTRAL AND SOUTHWEST MTNS. ADDITIONAL LIGHT TO MODERATE SNOWFALL ACCUMULATIONS ACROSS THE ABQ AND SAF AREAS ALONG WITH NE PLAINS OVERNIGHT WILL MAKE THIS STORM ONE TO REMEMBER FOR QUITE SOME TIME!

21Z SFC ANALYSIS SHOWED A 1010MB LOW PRES SYSTEM SPRAWLING OVER OKLAHOMA AND NORTH TEXAS WITH A STATIONARY BOUNDARY STRETCHING WESTWARD THROUGH THE TEXAS PANHANDLE INTO CENTRAL NEW MEXICO. THE LATEST WATER VAPOR LOOP SHOWS THE UPPER LOW OVER SE NM FINALLY PUSHING EAST INTO TEXAS. 400-200MB AIRCRAFT DATA SHOWS A 50-70 KNOT JET EMBEDDED WITHIN DEEPLY SATURATED WRAP AROUND BAND OVER CENTRAL NM. RADAR TRENDS ARE BEGINNING TO SHOW DEFORMATION ZONE OVER THE RIO GRANDE VALLEY LOOSING ITS FORCING AS THE 50-70 KNOT DIVES SOUTH AND THE LOW LEVEL BAROCLINIC ZONE WEAKENS WITH LOW PULLING EAST. STILL CANNOT RULE OUT BURSTS OF MODERATE SNOW WITHIN THIS BAND THROUGH THE EVENING SO LEFT HIGHLIGHTS FOR THESE AREAS INTACT.

12Z/18Z NAM GUIDANCE HAS BEEN THE MODEL OF CHOICE AS INITIALIZATIONS OF THE DETAILS ACROSS THE STATE...ESPECIALLY THE PRECIP FIELDS... HAVE BEEN VERY IMPRESSIVE. GENERAL AGREEMENT ALSO FROM THE 12Z GFS ALONG WITH THE 12Z UKMET AND 12Z ECMWF THRU SUNDAY NIGHT. QUICK LOOK AT THE EARLY MORNING MREF/SREF SOLNS ALSO PROVIDED SUPPORT FOR FCST. NAM SHOWS LARGE SCALE COMPLEX STORM SYSTEM PUSHING EAST OUT OF NM BY MID MORNING SUNDAY. SKIES WILL SLOWLY BECOME PARTLY CLOUDY TO MOSTLY CLEAR FROM WEST TO EAST OVERNIGHT. WILL ADD PATCHY FOG TO VALLEYS AND PORTIONS OF THE E PLAINS SUN MORNING AND MON MORNING AS NAM BUFKIT PROFILES AT KABQ AND KTCC SHOW SHALLOW SATURATED LAYERS EACH MORNING WITH THE AID OF SNOW COVER.

NEXT SYSTEM RIGHT ON THE HEELS OF LATEST RECORD BREAKING SYSTEM FOR LATE TUES SHOWING SIGNS OF MODEL FLIP FLOP ESPECIALLY WITH GFS. GFS SHOWING SYSTEM CLOSING OFF AND DIVING WELL FURTHER SOUTH INTO OLD MEXICO. DID NOT GET CHANCE TO LOOK AT MREF MEMBERS OUT THAT FAR BUT HAVE SEEN GFS DO THIS IN THE PAST FEW WEEKS AND CONFIDENCE IS LOW. LEFT POPS RELATIVELY UNCHANGED EXCEPT TO TWEAK TOWARD THE SOUTH. OTHERWISE... EXTENDED FORECAST CONTINUES TO BE ACTIVE WITH ANOTHER SYSTEM ON THE HORIZON NEXT WEEKEND.

&&

.PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 16 43 17 44 / 5 0 0 5 GALLUP.......................... 10 41 8 43 / 5 0 0 5 GRANTS.......................... 8 37 7 40 / 10 0 0 5 GLENWOOD........................ 19 50 24 53 / 0 0 0 5 CHAMA........................... 4 30 -5 30 / 30 0 0 10 LOS ALAMOS...................... 14 32 10 34 / 50 5 0 5 RED RIVER....................... 1 27 0 31 / 60 10 0 5 TAOS............................ 5 33 4 33 / 50 10 0 5 SANTA FE........................ 11 32 9 34 / 60 5 0 5 SANTA FE AIRPORT................ 16 34 12 35 / 60 5 0 5 ESPANOLA........................ 14 36 15 39 / 60 5 0 5 ALBUQUERQUE HEIGHTS............. 22 37 19 40 / 60 5 0 5 ALBUQUERQUE VALLEY.............. 18 40 13 42 / 60 0 0 5 ALBUQUERQUE FOOTHILLS........... 19 33 16 35 / 60 5 0 5 ALBUQUERQUE WEST MESA........... 20 38 18 39 / 50 0 0 5 SOCORRO......................... 20 42 24 48 / 40 0 0 5 SANDIA PARK/CEDAR CREST......... 13 31 11 35 / 60 5 0 5 MORIARTY/ESTANCIA............... 14 30 9 34 / 50 5 0 5 CARRIZOZO....................... 18 40 25 44 / 40 0 0 0 RUIDOSO......................... 17 37 20 41 / 30 0 0 0 RATON........................... 9 32 10 33 / 80 20 0 5 LAS VEGAS....................... 13 32 16 34 / 60 10 0 5 ROY............................. 18 30 17 34 / 70 20 0 5 CLAYTON......................... 20 29 18 32 / 90 30 0 0 SANTA ROSA...................... 20 40 21 36 / 30 10 0 5 TUCUMCARI....................... 22 38 19 37 / 50 10 0 0 FORT SUMNER..................... 21 43 22 40 / 30 10 0 0 CLOVIS.......................... 25 42 23 42 / 30 10 0 0 PORTALES........................ 23 44 22 46 / 30 10 0 0 ROSWELL......................... 26 47 24 45 / 40 0 0 0

&&

.ABQ WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL 5 AM MST SUNDAY FOR THE FOLLOWING ZONES...NMZ002>005-009>013-016>021.

BLIZZARD WARNING UNTIL 5 AM MST SUNDAY FOR THE FOLLOWING ZONES... NMZ006-007.

SNOW ADVISORY UNTIL 5 AM MST SUNDAY FOR THE FOLLOWING ZONES... NMZ015.

WINTER WEATHER ADVISORY UNTIL 5 AM MST SUNDAY FOR THE FOLLOWING ZONES...NMZ026.

&&

$$

GUYER

.SYNOPSIS...FOR THE PAST SEVERAL WEEKS THE LARGE SCALE PATTERN ACRS THE NRN HEMISHPHERE HAS BEEN DOMINATED BY LARGE BROAD TROF OVER THE NERN PAC. THAT RESULTED IN SPLIT FLOW DOWNSTREAM OVER NOAM. THE SPLIT FLOW WAS KEEPING COLD AIR BOTTLED UP WAY NORTH IN CANADA...AND RESULTING IN ABV TO MUCH ABV NORMAL TEMPS ACRS THE FCST AREA. SIG PCPN OCCURRED AS SRN STREAM SYSTEMS WORKED ACRS THE AREA...WITH THE LACK OF COLD AIR LEADING TO MORE LIQUID AND MIXED PCPN THAN TYPICAL AT THIS TIME OF YR.

THE SAME PATTERN EXPECTED TO PERSIST THROUGH THE FCST PERIOD. HOWEVER... THERE SEEMED TO BE AN INCREASING AMNT OF EVIDENCE TO SUGGEST THAT A SIG PATTERN CHC WL OCCUR AFTER THE END OF THE FCST PERIOD. THOUGH THE DETAILS ARE OBVIOUSLY MUCH IN QUESTION THIS FAR IN ADVANCE...THE TREND SEEMS TO BE FOR THE ERN PAC TROF TO SHIFT BACK W AND ALLOW HEIGHTS OVER THE NERN PAC TO RISE. THE RESULT SHOULD BE A TREND TOWARD MORE CONSOLIDATION OF THE FLOW AND A DOWNSTREAM TROF SOMEWHERE OVER NOAM. THAT WOULD LEAD TO TEMPS AND WX MORE TYPICAL FOR THIS TIME OF YEAR. &&

SHORT TERM...TONIGHT. SEVERAL PROBLEM AREAS EXIST IN THE SHORT TERM. THE FIRST PROBLEM...A HOLDOVER FROM OVERNIGHT AND TODAY...IS THE FOG. VISIBILITIES HAVE BEEN BOUNCING UP AND DOWN IN MOST OF THE FORECAST AREA TODAY...ALTHOUGH VSBYS HAVE GENERALLY BEEN LESS THAN A MILE IN VILAS COUNTY AND PARTS OF THE FOX VALLEY. FOG WILL BE MENTIONED IN THE ZONES WITHOUT AN ADVISORY SINCE THE SURFACE GRADIENT IS EXPECTED TO INCREASE A BIT OVERNIGHT AND ENOUGH MIXING SHOULD TAKE PLACE TO KEEP AWAY ANY WIDESPREAD DENSE FOG. ALSO...REPORTS OF DENSE FOG SEEM TO BE SPOTTY.

THE NEXT CONCERN IS PRECIPITATION ONSET...POPS AND TYPE. RADAR MOSAIC HAD A LARGE AREA OF PCPN IN MINNESOTA AND IOWA...ALONG WITH SOME IN ILLINOIS. THIS PCPN...ROTATING AROUND A SURFACE LOW ALONG THE KS/OK BORDER...WILL MAKE ITS WAY INTO THE AREA STARTING THIS EVENING AS THE LOW LIFTS NORTHEAST. BEST CHANCE OF PCPN SHOULD BE IN THE WEST AND SOUTHWEST...WITH LOWER POPS IN THE EAST...SINCE GFS APPEARS TO BE TOO FAST WITH THE SURFACE SYSTEM. PCPN TYPE IS A MAJOR CONCERN AS TEMPERATURES ACROSS NORTH CENTRAL WISCONSIN WERE HOVERING AROUND FREEZING AT 21Z. GUIDANCE INDICATES THICKNESSES AND 850 MB TEMPERATURES WARM ENOUGH FOR JUST RAIN. WARM ADVECTION MAY HELP FREEZING PCPN FROM BECOMING A PROBLEM IN NORTH CENTRAL TONIGHT AS MOS GUIDANCE SUGGESTS TEMPERATURES REMAINING STEADY AND THEN SLOWLY RISING THERE. ETA AND GFS COBB TECHNIQUE OUTPUT FOR RHI KEEP PCPN IN LIQUID FORM...BUT WILL STILL MENTION POSSIBILITY FOR FREEZING RAIN IN THE NORTH. REMOVED MENTION OF ICE PELLETS AS TAMDAR SOUNDINGS TO THE SOUTHWEST HAD A WARM ENOUGH WARM LAYER TO MELT ANY FROZEN PCPN BEFORE IT REACHES THE LOW LEVEL MOISTURE.

.LONG TERM...SUN THRU NEXT SAT. MAIN WX FEATURE WL BE STG SRN STREAM TROF EJECTING NE ACRS THE AREA AND BEING ABSORBED BY THE NRN STREAM. THE PATTERN AND SYSTEM HAD SOME SIMILARITIES TO THE DEC 22-23 EVENT. THAT SYSTEM WAS HANDLED VERY WELL BY THE GFS--WHICH AT FIRST SEEMED TO BE A TOO FAST AND TOO FAR E OUTLIER. LEANED TOWARD THE GFS FOR THE FCST...AND THE 12Z RUNS OF THE CANADIAN...UKMET...AND ECMWF SEEM TO HV TRENDED IN THAT DIRECTION.

DYNAMICS NOT EXPECTED TO BE QUITE AS INTENSE THIS TIME AROUND...BUT TRACK OF UPR SYSTEM FM MO/IA AREA TO NR THE SOO BY 12Z MON FAVORS ACCUMULATING SNOWS ACRS N-C AND POSSIBLY C-NE WI. BUMPED UP AMNTS ACRS THE N...AND WL UPDATE THE HWO. CURRENT THINKING IS THAT WE WL EVENTUALLY NEED A HEADLINE FOR THE EVENT...BUT NOT READY TO COMMIT TO THAT YET SO WL JUST LINE THINGS UP AND LET LATER SHIFTS TAKE ANOTHER LOOK.

FAIRLY QUIET WX EXPECTED ONCE THE SYSTEM PULLS AWAY. TAIL OF NRN STREAM SHRTWV WL BRUSH ACRS THE AREA LATE IN THE WK...AND THE GFS DID GENERATE PCPN FM THAT. BUT LOW AMPLITUDE PATTERN DOES NOT INSTILL CONFIDENCE IN THE EXACT TIMING SHOWN BY THE MODELS...AND DID NOT WANT TO HAVE LOW CHCS FOR SEVERAL PERIODS. LEFT PCPN OUT FOR NOW.

SOME PHASING POSSIBLE AS THE NEXT SRN STREAM TROF SHEARS NEWD DURING THE UPCOMING WEEKEND. TIMING AGAIN AN ISSUE...BUT WITH MORE MOISTURE PCPN COULD BE MORE SIG SO CARRIED A CHC ON SAT. &&

.GRB WATCHES/WARNINGS/ADVISORIES... NONE. &&

$$ MG WEATHER.GOV/GREENBAY

.DISCUSSION FOR AFTERNOON GRIDS/ZONES...

248 PM CST

UPR LOW CENTERED OVR NRN MO THIS AFTN...WITH STRONG S/WV ASSOCIATED WITH 130KT JET STRK LIFTING NORTHEAST ACROSS MID MS/LWR OH VLYS. DRY SLOT OVR MUCH OF FCST AREA SINCE THIS MORNING STARTING TO SHOW SIGNS OF CONVECTIVE DVLPMNT...WITH SCT RW/TRW BEGINNING TO DVLP BENEATH DIVERGENT LEFT EXIT REGION OF UPPER JET STRK ALONG LOW LEVEL OCCLUDED FRONT AS UPPER LVL FORCING INCRSG WITH APPRCH OF S/WV. RECENT ACARS AND FCST SOUNDINGS AS WELL AS SPC/RUC MESOANALYSIS GRAPHICS INDICATE CAPE VALUES MARGINAL...THOUGH GIVEN STRENGTH OF UPPER FORCING AND LOW LEVEL CONVERGENCE VCNTY OCCLUSION EXPECT SCT RW/TRW TO CONTINUE NEXT FEW HOURS AS S/WV CONTINUES TO APPRCH. MAIN UPPER LOW CENTER LIFTS NORTHEAST ACROSS FCST AREA THIS EVENING...THOUGH SECONDARY VORT MAXIMA WRAPPING AROUND BACK SIDE RESULTS IN LINGERING UPPER TROUGHINESS AND EXTENDED PERIOD OF WEAK MID/UPR LVL FORCING INDICATED BY Q CONVERGENCE FIELDS. THIS S/WV TROUGH AXIS FINALLY MOVES ACROSS FCST AREA MONDAY MORNING...THUS EXPECT SOME LINGERING CHC FOR LIGHT SHOWERS OVRNGT HOURS INTO MONDAY MORNING.

LOW LEVEL COLD ADVCTN TNGT RESULTS IN THICKNESS VALUES FALLING ESPECIALLY AFTR MDNGT...WITH 1000-850 HPA BELOW 1300 METERS AND 850-700 HPA DOWN TO 1520-1530 METERS BY 12Z MON. FCST SOUNDINGS AND TSECTS INDICATE MOIST LAYER FAIRLY SHALLOW BY THAT TIME HOWEVER...WITH CLOUD TOP TEMPS GENERALLY WARMER THAN -10C THAT WOULD NOT SUPPORT SIG ICE CRYSTAL NUCLEATION. HOWEVER...GIVEN PROLONGED FORCING WITH SECOND VORT/TROUGH AND POTENTIAL FOR DEEPER CLOUD LAYER OR SEEDING FROM COLDER HIGHER CLOUD LAYER...WILL MENTION LIGHT RA/SN AFTER MDNT INTO MON MRNG. UPPER TROUGH AXIS THEN SHIFTS EAST OF FCST AREA BY AFTN...WITH MODEL TSECTS AND DIV-Q/OMEGA FIELDS SUGGESTING FAIRLY STRONG DEEP LAYER SUBSIDENCE DVLPG. THUS WILL GO DRY FOR MON AFTN WITH CLRG SKIES BY EVENING AS SFC HIGH PRESSURE BUILDS ACROSS MID MS/OH VLYS.

MID WEEK APPEARS DRY AND CONTINUED MILD AS ANOTHER UPPER TROUGH CUTS OFF/CLOSES OFF OVER THE SOUTHWEST...AND NORTHERN BRANCH OF JET BECOMES MORE ZONAL. GFS/NAM SIMILAR WITH NRN STRM S/WV MOVG THROUGH THE UPPER MIDWEST TUES/TUES NGT...THOUGH WITH DRY LOW LEVELS AND SFC RIDGE AXIS BLOCKING OFF MOISTURE RETURN FROM THE GULF EXPECT NO MORE THAN SOME MID/HIGH CLOUDS WITH THIS FEATURE. SOUTHWESTERN UPPER TROUGH KICKS OUT LATER IN THE WEEK...WITH GLOBAL MODELS DVLPG BROAD TROUGH IN SOMEWHAT PHASED NRN/SRN STREAMS BY FRI/SAT. BEST PCPN CHANCES INITIALLY TO OUR SOUTH AND OFF TO OUR NORTH...UNTIL MAIN UPPER TROUGH APPRCHS FRI NGT AND SATURDAY. WILL CARRY CHC POPS FOR INITIALLY RA FRI NGT AND THEN RA/SN SAT AS COLDER AIR MOVES IN BEHIND SFC COLD FRONT.

TEMPS THROUGH THE PERIOD AGAIN TO REMAIN FAIRLY MILD. MAV GUIDANCE NUMBERS GENERALLY PREFERRED EARLY ON...THEN GENERALLY AT OR A LITTLE ABOVE THE HPC/MEX NUMBERS MID WEEK AS LLVL SW FLOW DVLPS.

RATZER

&&

.AVIATION DISCUSSION FOR 06Z TAFS...

MAIN PROBLEM OVERNIGHT WILL CONTINUE TO BE RAGGED CIGS AS COLD AIR WRAPS INTO DEPARTING LOW PRESSURE CENTER OVR NRN LK MI. CIGS HAVE BEEN GENLY VFR THRU MUCH OF THIS EVENING...BUT ARE IN THE PROCESS OF LWRG INTO A MORE SLD LOW RANGE MVFR DECK WHICH WILL OVERSPREAD TERMINAL AREA FROM SW BY 07Z. LEADING EDGE OF THESE LWR CIGS NOW ADVANCING ACRS NWRN AND CNTRL IL AND ARE MOVG ENEWD NR 30 KTS. COLD/DRY ADVECTION IN LLVLS SHOULD KEEP VIS UNRESTRICTED THRU MOST OF PERIOD XCP INVOF LGT SHWRS WHICH WILL ALSO MOVE INTO RGN WITH COLD AIR INFLUX. BY LATE TNGT...LGT SHWRS WILL LIKELY CHG OVER TO FLURRIES AS SFC TEMPS COOL INTO MID 30S. DO NOT EXPECT PCPN TO BE HEAVY ENUF TO ACCUMULATE ANY ICE OR SNOW ON RUNWAYS. WRAP ARND STRATO CU DECK TO RMN IN PLACE THRU MIDDAY MON BEFORE WX SYS MOVES FAR ENUF E OF AREA TO ALLOW FOR CLRG TO TAKE PLACE BY END OF FCST PERIOD.

OTHER PROBLEM WILL BE WINDS. SWLY WINDS GUSTING TO NR 30 KTS OVR WRN/NWRN IL WILL BE OVERSPREADING TERMINALS BY 07Z AS COLD AIR ARRIVES BTWN 05 AND 07Z. ELEVATED WIND SPEEDS TO CONT THRU MON MRNG WITH GRDL WDSHFT TO WNW AFT 12Z. WINDS TO DMNSH MID-LATE AFTN MON AS COLD ADVECTION RELAXES.

MERZLOCK

&&

.LOT WATCHES/WARNINGS/ADVISORIES... .IL...NONE. .IN...NONE. .LM...SCA IL WATERS TO GYY THRU 00Z TUESDAY. SCA GYY TO MICHIGAN CITY THRU 06Z TUESDAY.

&&

$$

.SHORT TERM... THE UPPER SYSTEM THAT HAS HAS BROUGHT A SNOW STORM TO THE WRN AND CENTRAL PORTIONS OF THE COUNTRY...SEVERE WEATHER TO THE DEEP SOUTH...AND EVEN A FEW THUNDERSTORMS TO LOWER MICHIGAN ON NEW YEARS EVE IS CURRENTLY IN THE PROCESS OF EXITING THE COUNTRY. ONE MORE SET OF SHORT WAVES RIDING ON THE BACKSIDE OF THE MAIN SYSTEM OVER WI/IL IS ALL THAT REMAINS TO AFFECT LOWER MICHIGAN WITH THIS SYSTEM. THE MAIN CHALLENGE IN THE SHORT TERM IS DETERMINING PCPN CHCS AND PCPN TYPE TODAY AS THE LAST UPPER WAVE PASSES THROUGH. THE ONLY OTHER ISSUE IS TO DETERMINE THE TIMING OF THE CLEARING BEHIND THIS SYSTEM LATER THIS AFTERNOON AND TONIGHT.

THE WAVE THAT HELPED TO PRODUCE THE SHOWERS AND STORMS LAST EVENING ACROSS THE SE HALF OF THE CWFA HAS MOVED EAST...AND ONLY A COUPLE LIGHT SHOWERS REMAIN AS OF 0830Z PER THE KGRR 88D. SFC ANALYSIS AT 08Z SHOWS A SFC TROUGH/SECONDARY FRONT EXTENDING FROM GREEN BAY DOWN THROUGH THE QUAD CITIES. AS THE UPPER TROUGH AND THE ASSOCIATED SFC TROUGH SWING ACROSS THE CWFA LATER THIS MORNING...A FEW MORE SHOWERS ARE EXPECTED TO REDEVELOP. SHOWERS WILL LIKELY HAVE A LITTLE BETTER COVERAGE UP NORTH AS THERE IS A LITTLE BIT BETTER DEEP MOISTURE TO WORK WITH. EITHER WAY...THE SHOWERS ARE NOT EXPECTED TO AMOUNT TO MUCH MORE THAN ANOTHER TENTH OF AN INCH OF PCPN. AS FAR AS PCPN TYPE IS CONCERNED...TEMPS ARE STILL IN THE 40S ACROSS THE CWFA. A TAMDAR FLIGHT OUT OF KORD AROUND 05Z SHOWED THE FREEZING LEVEL THERE WAS STILL AROUND 4K FEET AND SLOWLY LOWERING. ANY SHOWERS INITIALLY SHOULD START OUT AS RAIN THIS MORNING. PCPN WILL BEGIN TO CHANGE TO A MIX LATER THIS MORNING ONCE THE SFC TROUGH MOVES THROUGH AND MORE COOLER AIR ADVECTS IN. THE UPPER TROUGH IS EXPECTED TO PASS EAST OF THE CWFA BY MID AFTERNOON...ALLOWING PCPN TO END. THERE MAY BE A FEW PLACES THAT SEE PCPN GO OVER TO ALL SNOW BRIEFLY BEFORE ENDING...BUT THIS WILL BE A VERY SHORT TIME IF AT ALL...AND WE JUST HAVE GONE WITH A RA/SN MIX AFTER MID MORNING. TEMPS ARE EXPECTED TO FALL SLOWLY THROUGH THE DAY FROM EARLY HIGHS THIS MORNING IN THE 40S WITH THE COLD AIR ADVECTION AND LOW SUN ANGLE.

SOME CLEARING WILL BE POSSIBLE RIGHT AROUND SUNSET OVER THE NW CORNER OF THE CWFA PER 925 MB RH PROGS OFF OF THE NAM AND GFS. THIS CLEARING SHOULD PROGRESS ACROSS THE CWFA FROM WEST TO EAST THROUGH THE EVENING. SKIES MAY GO CLEAR BRIEFLY AFTER THE CLEARING LINE MOVES THROUGH. A SHORT WAVE TROUGH WILL THEN APPROACH THE AREA LATE IN THE NIGHT...PROVIDING A CANOPY OF THIN HIGH CLOUDS LATE IN THE NIGHT. ALSO...THE MODELS ARE HINTING ARE HINTING AT SOME LOW CLOUD DEVELOPMENT UP NORTH OVER THE HIGHER ELEVATIONS OF CENTRAL LOWER MICHIGAN. THIS LOOKS LIKE IT WOULD BE TEMPORARY WITH THE GOOD PUSH OF DRIER AIR FROM THE NW OVERNIGHT. WE WILL GO WITH BECOMING PARTLY CLOUDY/PARTLY CLOUDY OVER THE CWFA TONIGHT. LOWS SHOULD DIP INTO THE MID 20S OVER THE NE CORNER OF THE CWFA TO THE LOWER 30S DOWN SOUTH.

THE PERIOD OF TUE THROUGH WED AFTERNOON LOOKS LIKE A FAIRLY QUIET AND TRANQUIL PERIOD...ESPECIALLY FOR THE BEGINNING OF JANUARY FOR LOWER MICHIGAN. LOWER MICHIGAN IS EXPECTED TO BECOME UNDER THE INFLUENCE OF BROAD LONG WAVE RIDGING ALOFT INBETWEEN LONG WAVE TROUGHING OVER THE CANADIAN MARITIMES AND OVER THE NE PACIFIC. THERE WILL BE TWO SHORT WAVE TROUGHS MOVING THROUGH THE LONG WAVE RIDGE AND ACROSS THE GREAT LAKES. THE TROUGH ON TUE WILL HAVE SOME HIGH CLOUDS OVERHEAD EARLY...BUT THESE SHOULD MOVE EAST OF THE CWFA DURING THE AFTERNOON. THE TROUGH COMING IN ON WED IS EVEN MORE MOISTURE STARVED AND ONLY A FEW THIN HIGH CLOUDS AT WORST WILL BE IN PLACE. RETURN FLOW IN THE LOWER LEVELS WILL SET UP LATE TUE AND INTO WED ON THE BACKSIDE OF THE SFC RIDGE THAT PASSES EAST DURING THE DAY ON TUE. THIS WILL HELP TO MODIFY TEMPS AS H850 TEMPS INCREASE FROM AROUND -1C TO -2C TUE MORNING TO AROUND +4C WED AFTERNOON. HIGHS ON TUE SHOULD WARM INTO THE LOW TO MID 40S...AND TEMPS SHOULD WARM INTO THE MID TO POSSIBLY UPPER 40S ON WED WITH PLENTY OF SUNSHINE.

.LONG TERM... SPLIT FLOW WILL BE IN PLACE FOR THE BEGINNING OF THE LONG TERM PERIOD...WEDNESDAY NIGHT. THE FLOW TRENDS WITH TIME TOWARD ZONAL BY THE END OF THE LONG TERM PERIOD WHICH IS SUNDAY. WILL CONTINUE THE DRY FORECAST FROM WEDNESDAY NIGHT THROUGH THURSDAY NIGHT WITH A MILD SOUTHWEST FLOW IN PLACE. FRIDAY AN UPPER TROUGH APPROACHES FROM THE WEST IN THE INCREASINGLY ZONAL FLOW. THE TROUGH MOVES THROUGH IN THE FRIDAY NIGHT AND SATURDAY TIME FRAME. ANY PRECIP FRIDAY INTO FRIDAY EVENING SHOULD BE RAIN...BUT AS COLDER AIR ADVECTS IN BEHIND THE UPPER TROUGH FRIDAY NIGHT AND SATURDAY...SOME SNOW MAY MIX IN. HAVE LINGERED POPS INTO SATURDAY NIGHT...BUT THIS MAY END UP BEING A DRY PERIOD AS IT LOOKS LIKE A SURFACE RIDGE MOVES THROUGH THE FORECAST AREA. LEFT SUNDAY DRY. OVERALL...MID WEEK LOOKS DRY WITH BETTER CHANCES FOR PRECIPITATION TOWARD THE END OF THE WEEK. IT SHOULD BE A MILD PERIOD OVERALL...WITH A TREND TOWARD COLDER WEATHER INTO THE WEEKEND AND ESPECIALLY INTO NEXT WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...SMALL CRAFT ADVISORY FOR THE ENTIRE NEARSHORE THROUGH 11Z TUE.

&&

$$

NJJ DUKE

&&

.SHORT TERM... TONIGHT THROUGH THURSDAY... IR AND WATER VAPOR IMAGERY CONTINUED SHOWING AN IMPRESSIVE CYCLONIC CIRCULATION JUST NORTH OF PHOENIX THIS AFTERNOON. BUT THE ASSOCIATED MOISTURE WAS NOT IMPRESSIVE...WITH SOME OF THE WRAP-AROUND CLOUDINESS BREAKING UP AS THE LOW SAGS SLOWLY SOUTH. AIRCRAFT WINDS FROM 41 THSD FT WERE REPORTED TO BE MUCH MORE NORTHERLY COMPARED TO MODEL WINDS TODAY. ALTHOUGH THE MID LEVEL MOISTURE TENDS TO INCREASE WITH TIME EARLY THIS WEEK ACROSS THE CENTRAL PORTIONS OF OUR AREA...THE HIGH LEVEL MOISTURE DECREASES...ACCORDING TO LATEST NAM CROSS SECTIONS. OVERALL PRECIP WATER AT PHOENIX APPEARS A BIT OVERDONE...WITH ABOUT .50 INCH PROGGED FOR BOTH TUES AND WED. AS THE CLOSED LOW CUTS ACROSS OUR CWA TONIGHT...HEIGHT FALLS AND A LITTLE MORE INSTABILITY COULD GENERATE SOME LIGHT SHOWERS OR SPRINKLES ACROSS ZONE 24. SOME WARMER AIR ALOFT AND LESS MOISTURE SHOULD ALLOW FOR A DOWNWARD TREND IN POPS FOR THAT AREA INTO TUESDAY NIGHT. CLOUDS WILL STILL HANG AROUND...BUT CHANCES OF ANY PRECIP MAKING IT`S WAY TO THE GROUND APPEAR SLIM.

FLAT UPPER RIDGE AND MUCH WEAKER SURFACE GRADIENTS ARE STILL EXPECTED ON WEDNESDAY. WILL ADJUST TEMPERATURES UPWARD A LITTLE AND CALL FOR IMPERIAL/EL CENTRO TO WARM INTO THE MID 70S BY THURSDAY. OTHERWISE...NO LARGE DAY-TO-DAY TEMPERATURE CHANGES EXPECTED. &&

.LONG TERM... THURSDAY NIGHT THROUGH MONDAY... FLAT RIDGE IN PLACE OVER SOUTHEAST CA AND ARIZONA THU NIGHT BEFORE ANOTHER DISTURBANCE SWINGS THROUGH THE WRN CONUS FRI/SAT. GFS AND ECMWF SEEM TO BE IN FAIRLY GOOD AGREEMENT WITH THIS SYSTEM SLIDING INLAND...THROUGH THE GREAT BASIN...AND OVER THE FOUR CORNERS REGION. THE AFOREMENTIONED TRAJECTORY WOULD BE DRY FOR MUCH OF OUR CWA...ESPECIALLY THE WRN PORTION OVER SE CA AND ALONG THE CO RIVER VALLEY. THE MAIN CONCERN OUT WEST WILL BE WINDS...AS THE PRESSURE GRADIENT TIGHTENS AND FAVORS A MODERATE TO STRONG NORTHERLY WIND. BREEZY TO LOCALLY WINDY CONDITIONS WILL START FRI AND CONTINUE THROUGH SAT. AS FOR THE ERN CWA...MODELS ARE BREAKING OUT SOME PRECIP OVER MAINLY THE HIGHER TERRAIN OF SOUTHERN GILA COUNTY (AZ ZONE 24)...WHILE THE MEXMOS HAS A 12 POP FOR PHX FRI INTO SAT. CURRENT FORECAST HAS A SLIGHT CHANCE CWA WIDE FRI NIGHT/SAT...AND FOR NOW...THIS LOOKS OKAY. AGAIN...WITH THE INLAND TRAJECTORY OF THIS SYSTEM...AND WITH THE PATTERN BEING SO PROGRESSIVE VIA BOTH THE GFS AND ECMWF...WE`LL BE HARD PRESS TO GET ANY PRECIP ANYWHERE BUT THE HIGHER TERRAIN. HOWEVER...AT THIS TIME...I FEEL COMPLETELY PULLING POPS OVER THE GREATER PHX AREA IS A BIT HASTY AND TOO OPTIMISTIC (IF YOU WILL). LATEST GUIDANCE SUGGESTS SEVERAL DEG OF COOLING THU THROUGH SAT...AND HAVE MADE MINOR TWEAKS TO THE TEMP GRIDS DURING THIS PERIOD TO REFLECT THIS THINKING. HEIGHTS WILL BE QUICK TO REBUILD SAT INTO SUN...FOR WARMER TEMPS AND MOSTLY CLEAR SKIES SUN AND MON.

&&

.AVIATION... 00Z TAFS AND TWEBS ADEQUATELY DEPICT EXPECTED WEATHER. SEE TAFS PHXTAFPHX...PHXTAFIWA...PHXTAFYUM...LAXTAFBLH AND LAXTAFIPL FOR MORE DETAILED INFORMATION.

AVIATION DISCUSSION IS NOT UPDATED FOR AMENDED TAFS. &&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE. &&

$$

NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT

WEATHER.GOV/PHOENIX

10/22

.SYNOPSIS...PRECIPITATION WILL CONTINUE TO MOVE INLAND THROUGH MIDDAY AND THEN CONTINUE OFF AND ON THROUGH TUE. THE PRECIPITATION MAY BECOME BECOME HEAVY AT TIMES TUESDAY AHEAD OF A COLD FRONT THAT WILL MOVE SOUTHEAST ACROSS THE AREA LATE IN THE AFTERNOON. ANOTHER LOW WILL MOVE EAST ALONG THE WASHINGTON-OREGON BORDER WEDNESDAY. AN UPPER LEVEL TROUGH WILL MAINTAIN A COOL AND SHOWERY PATTERN THURSDAY.

&&

.SHORT TERM...RAIN SPREADING INLAND RATHER QUICKLY THIS MORNING ALONG WITH THE WARM AIR. FREEZING LEVEL OVER SEATTLE PUSHING 5000 FT ACCORDING TO ACARS DATA AND ALREADY OVER 6000 FT ALONG THE COAST. THE PRECIPITATION WILL CONTINUE TO WORK INLAND THIS MORNING...PRETTY MUCH COVERING ALL AREAS BY NOON.

WHICH BRINGS US TO AN ISSUE...AND AN UPDATE. CURRENTLY HAVE A WINTER STORM WATCH FOR THE CASCADES FOR TONIGHT. WITH A LOOK AT THE SITUATION AND THE PROGRESS OF THE PRECIP...WILL CHANGE THIS TO A WINTER WEATHER ADVISORY FOR A PERIOD OF SNOW AND THEN SOME FREEZING RAIN. THIS WILL BE FOR THE TODAY THROUGH TONIGHT TIME FRAME WITH AN EMPHASIS ON THIS AFTERNOON AND EVENING. AFTER THIS EVENING THE PRECIP SHOULD LIGHTENUP AS THE FOCUS OF THE FORCING SHIFTS NORTH AS WE END UP IN THE WARM SECTOR. THE ADVISORY WILL FOCUS ON THE PASSES AS THAT IS WHERE THE FREEZING RAIN WILL BE. ELSEWHERE IN THE MOUNTAINS THE SNOW WILL TURN TO RAIN BELOW ABOUT 5000 FT...WHICH WILL BRING US TO THE NEXT ISSUE.

POTENTIAL FLOOD CONCERNS. WITH THE QPF (RAINFALL ESTIMATE) FOR THE NEXT FEW DAYS PROVIDED TO THE RIVER FORECAST CENTER THIS MORNING...SEVERAL RIVERS IN WESTERN WASHINGTON BECOME A CONCERN FOR FLOODING. LOOKING AT THE SAT PIX...THERE IS PLENTY OF MOISTURE THIS SYSTEM IS TAPING INTO...IT WILL JUST DEPEND WHETHER IT IS FOCUSED HERE OR IN BRITISH COLUMBIA. THE RIVER GUYS ARE STILL WORKING ON MANY OF THE RIVERS BUT A COUPLE HAVE SURFACED THAT MAY NEED TO BE DEALT WITH. OF COURSE THE SKOKOMISH IS ONE...BUT THE SNOHOMISH WATERSHED...CHEHALIS AND THE SATSOP COME CLOSE TO FLOOD IN THIS SCENARIO. RIVERS WON`T BE CRESTING UNTIL TUE NIGHT THRU WED...SO WILL WAIT FOR THE FINAL NUMBERS TO COME THROUGH TO DECIDE WHERE TO POST A WATCH. A WATCH FOR THE SKOKOMISH IS A SURE BET.

WILL BE ISSUING AN UPDATE SHORTLY...MAINLY TO CHANGE THE CASCADE HEADLINE BUT WILL LIKELY TWEAK AND TWIDDLE WITH THE REST OF THE AREA AS WELL. CERNIGLIA

.LONG TERM...FROM PREVIOUS DISCUSSION...MODELS APPEAR CONSISTENT IN SHOWING ANOTHER WARM FRONT MOVING INTO THE AREA FRI WITH A STREAM OF MOIST AIR AIMED INTO OUR AREA NEXT WEEKEND AND A SERIES OF DIFFICULT TO TIME SYSTEMS MOVING THRU. WILL NOT MAKE CHANGES TO THE ONGOING BROAD BRUSH FORECAST AT THIS TIME. ALBRECHT

&&

.AVIATION...CEILINGS NEARLY UNIFORM 5K-6K FT AROUND PUGET SOUND THIS MORNING. WARM FRONT MOVING IN WILL LOWER THEM TO 2K-3K FT IN RAIN BY NOON. SOME VISIBILITY RESTRICTIONS ON THE ORDER OF 4-5SM IN MODERATE RAIN AT TIMES. POSSIBLY A LULL IN RAIN AND BRIEF LIFTING OF CEILINGS TONIGHT...BUT THEN COLD FRONT WILL BRING MORE RAIN AND LOWER CEILINGS BY TUE MORNING. CHB

.MARINE...SYSTEM LOOKING STRONGER THAN PREVIOUS FORECASTS AND HAVE HOISTED GALES MOST WATERS. WIND WILL BE STRONG TODAY...WITH POSSIBLY A LULL TONIGHT...BUT THEN STRONG AGAIN TUESDAY. GALE WARNINGS IN FORCE THROUGH TUESDAY 4 PM BUT COULD LAST A BIT LONGER. COULD GET GALE FORCE SW WINDS IN PUGET SOUND TUE AFTERNOON WITH FRONTAL PASSAGE AND ALSO GALE WESTERLIES DOWN THE STRAIT. BURKE

.SEW WATCHES/WARNINGS/ADVISORIES... .WINTER WEATHER ADVISORY FOR THE CASCADE PASSES THROUGH TONIGHT. .GALE WARNING THROUGH TUESDAY AFTERNOON COAST...STRAIT ENTRANCES... ADMIRALTY INLET...AND CAMANO ISLAND TO POINT ROBERTS. .SMALL CRAFT ADVISORY THROUGH TUESDAY AFTERNOON PUGET SOUND AND HOOD CANAL.

$$

WEATHER.GOV/SEATTLE