Forecast Discussions mentioning "ACARS", "MDCRS", "AIRCRAFT" or "AMDAR" received at FSL on 02/09/04

IN NEBRASKA IS SLOWLY DEEPENING FROM 15 UTC TO 20 UTC. THE PROFILER WIND ANALYSIS AND MDCRS FROM 13 UTC TO 20 UTC SHOW INCREASE IN WINDS OVER NEBRASKA AND KANSAS TO 100 KNOTS OR MORE. THE WAVE OVER THE ROCKY MOUNTAINS HAS BAROCLINIC ENERGY AND THERE IS LOTS OF VORTICITY AT 500 MB. THE ETA AND GFS MODELS PICK THESE FEATURES IN THEIR ANALYSIS. LOOKING AT CROSS SECTIONS WE SEE THE VERTICAL COMPONENT OF RELATIVE VORTICITY IS LARGE SHOWING THE STRATIFICATION INCREASE IN THE AIR COLUMN. POTENTIAL VORTICITY IS RELATIVELY LARGE IN THE MODEL FORECASTS AS THIS SYSTEM MOVES EAST TOWARD THE FORECAST AREA. WILL USE THE ETA MODEL FOR THE FORECAST FOR TONIGHT AND MONDAY.

MOISTURE FIELD WAS INITIALIZED RATHER OKAY AND THERE IS AN INVERSION AS WELL. THE ETA INITIALIZED THE SURFACE...850 AND 900 TO 800 MB DEWPOINTS FIELD. WILL KEEP SKIES MOSTLY CLOUDY. THERE MAY BE SOME CLEARING THIS EVENING BUT THE SATELLITE IR SHOWS ENHANCED CLOUDS OVER IOWA MOVING NORTH. MOST OF THE VORTICITY WILL MOVE NORTHEAST INTO WISCONSIN. THE INVERSION SEEN ON THE ACARS DATA FROM 931 MB TO 710 MB HAS TRAPPED A LOT OF MOISTURE IN THE LOWER LAYERS.

THERE IS ENOUGH MOISTURE TO PROVIDE SNOW FLURRIES OR LIGHT SNOW TONIGHT. WILL FORECAST LIGHT SNOW LIKELY. THEN A CHANCE OF SNOW FOR THE SECOND VORTICITY MAXIMUM TO PASS THROUGH MONDAY MORNING.

WILL ADD TO THE FORECAST A SLIGHT CHANCE OF SNOW ON TUESDAY NIGHT AND WEDNESDAY NIGHT AS TWO MORE 500 MB WAVES ARE FORECAST TO MOVE THROUGH. THERE IS NO FORECAST SIGNIFICANT 850 MB MOISTURE TRANSPORT THROUGH THE PERIOD. WILL MAKE SLIGHT ADJUSTMENTS TO THE LOW AND HIGH TEMPERATURES. WHW &&

.LOT...WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LK MI...GALE WARNING FOR ALL OF LAKE MICHIGAN TONIGHT.

&&

$$



.SYNOPSIS...THE STRONG UPPER LEVEL RIDGE BUILDING OVER THE REGION TODAY WILL REMAIN IN PLACE AND PRODUCE DRY WEATHER THROUGH THURSDAY. WEAK WEATHER SYSTEMS PASSING TO THE NORTH WILL BRING SOME CLOUDS TO THE AREA AT TIMES TODAY THROUGH TUESDAY. AREAS OF NIGHT AND MORNING FOG WILL FORM UNDER THE INFLUENCE OF THE RIDGE.

&&

.DISCUSSION...SATELLITE IMAGERY SHOWS PLENTY OF LOW LEVEL MOISTURE STILL OVER WESTERN WASHINGTON THIS MORNING. ACARS SOUNDINGS AND SANDPOINT PROFILER SHOW VERY LIGHT WINDS 850 MB AND BELOW. SATELLITE IMAGERY DOES SHOW SOME CLEARING OVER SOUTHERN BRITISH COLUMBIA BUT WITH THE RIDGE BUILDING MOSTLY OFFSHORE AT THIS POINT. 12Z MODEL RUNS BRING A VERY WEAK SHORTWAVE DOWN IN THE NORTHERLY FLOW THIS MORNING WITH THE SHORTWAVE OVER THE SOUTHERN PORTION OF THE CWA THIS AFTERNOON. WILL UPDATE THE FORECAST TO KEEP CHANCE OF SHOWERS IN THE FORECAST FOR THE SOUTHERN PORTION OF THE CWA INCLUDING THE CENTRAL CASCADES THIS AFTERNOON. IN ADDITION WILL KEEP MORE CLOUD COVER OVER THE CENTRAL PUGET SOUND AREA. IMPROVING TREND STILL ON TRACK WITH THE UPPER LEVEL RIDGE BUILDING OVER THE OFFSHORE WATERS THROUGH MONDAY. IN ADDITION SURFACE HIGH PRESSURE BUILDING OVER SOUTHERN BRITISH COLUMBIA. SURFACE GRADIENTS ARE STILL LIGHT MONDAY MORNING FOR PLENTY OF MORNING FOG. OFFSHORE LOW LEVEL FLOW INCREASING ON TUESDAY AS THERMALLY INDUCED TROUGH MOVES UP THE OREGON COAST. FIRST LOOK AT 12Z GFS SHOWS LITTLE CHANGE FROM PREVIOUS THINKING WITH UPPER LEVEL RIDGE OVER THE AREA AND DRY WEATHER UNTIL THE END OF THE WORK WEEK. FELTON

&&

.SEW...NONE.

.KATX...VCP21/CSR21...OPERATIONAL.

&&

$$



.DISCUSSION... TROF CONTINUES TO CARVE ITSELF OUT ACROSS THE CENTER OF NOAM WITH LEAD 300MB JET ADVANCING NORTH ACROSS THE STRAIGHTS THIS MORNING WITH RIGHT ENTRANCE REGION ACROSS LAKE MICHIGAN. SHORT WAVE EMBEDDED WITHIN THE FLOW WAS TRACKING NORTHEAST TOWARD THE U.P. WITH WEAKENING SUBSIDENCE NOTED ON THE H2O VAPOR LOOP TRENDS. AT THE SURFACE, COLD FRONT WAS MAKING PROGRESS ACROSS THE MISSISSIPPI RIVER VALLEY WITH CYCLONIC BULGE NEAR KLSE AT 06Z. RADAR REFLECTIVITIES SHOW A NARROW LINE OF SNOW FROM NEAR KORD...EXTENDING ACROSS LAKE MICHIGAN...AND MOVING EAST NEAR 30 KTS. THE SOUTHERN HALF OF THIS ACTIVITY CONTINUES TO WEAKEN AND WARMING TEMPS PER IR SATELLITE CHANNEL. GRADIENT REMAINS TIGHT ACROSS THE STATE THIS MORNING AND WITH THE PASSAGE OF COLD FRONT...WIND GUSTS ACROSS IOWA WERE RUNNING CLOSE TO 35 KTS AS ISALLOBARIC RISE COMPONENT OF 4MBS/3HRS. THIS WILL BE OUR MAIN ISSUE TODAY.

TODAY... FIRST ON OUR DOCKET WILL BE THE SNOW. RUC AND LOCALLY PRODUCED ETA-XX HAVE AN EXCELLENT HANDLE THUS FAR WITH MAIN ISENTROPIC LIFT ON THE 290K SURFACE TO OCCUR BETWEEN 12-15Z. THE LOWEST CPD/S REMAIN ALONG AND NORTH OF I69 BUT WITH MAIN DYNAMICS LIFTING WELL NORTH OF THE REGION...WOULD EXPECT THIS ACTIVITY TO DECREASE IN INTENSITY AS IT PROGRESSES ACROSS THE CWA. FURTHER SOUTH, IT WILL BE TOUGH TO SEE ANY FLAKES FALL WITH CPD/S ABOVE 50MBS AND AFOREMENTIONED DEPARTING DYNAMICS. TEMPERATURES APPEAR TO BE FINALLY COME IN LINE WITH OUR CURRENT GRIDS (UNLIKE THE 40S WE WERE SEEING THIS TIME YESTERDAY). TRAJECTORY FORECASTS ORIGINATE FROM CENTRAL ILLINOIS WHERE HIGHS WERE IN THE MID 30S, HOWEVER, THESE PARCELS WILL HEAD ACROSS SNOWPACK COMBINING WITH CLOUD COVER TO HOLD BACK TEMPS FROM UPPER 20S NORTH TO AROUND FREEZING SOUTH. MODELS SUGGEST LAYER MAY DRY OUT ENOUGH SOUTH OF THE DTW-ARB LINE FOR SOME BREAKS IN THE CLOUD COVER BUT REMAIN MOCLOUDY. NOW, MAIN CONCERN IS WINDS AND IN A NUTSHELL, BELOW ADVISORY CRITERIA. BUFKIT MOMENTUM TRANSFER EQUATIONS POINT TOWARD 40KTS WHICH IS DOWN FROM PREVIOUS RUNS...AND WILL LIKELY BE A LITTLE BIT LESS. WHILE ISENTROPIC DOWNGLIDE DOES OCCUR...CROSS SECTIONS PARALLEL TO THE THETA FIELD DO NOT INDICATE CRASHING THETA SURFACES INTO THE GROUND LIMITING MIXING POTENTIAL. FURTHERMORE, H2O VAPOR LOOPS TRENDS SHOW SUBSIDENCE WEAKENING WITH TIME AND LIFTING NORTH WITH WAVE. WHILE GUSTS TO 40 MPH ARE EXPECTED...THIS IS BELOW WIND ADVISORY CRITERIA.

TONIGHT... COLUMN MOISTENS UP ONCE AGAIN WITH COLD ADVECTION OVER LAKE MICHIGAN AS MAIN TROF AXIS SLIDES INTO THE STATE. SOME INDICATION OF LEAD WEAK SHORT WAVE NOW OVER THE NORTHERN PLAINS MAY BRING A BRIEF SHOT OF LIFT AS SEEN IN THE WEAK DPVA FIELDS. THERMAL FIELDS ALSO RESPOND SOMEWHAT WITH WEAK, YET EVIDENT, Q-VECTOR CONVERGENCE ACROSS THE REGION (MAINLY SOUTHERN HALF). EITHER WAY, WE WILL CONTINUE WITH CHANCE OF LIGHT SNOW SHOWERS. LATE TONIGHT, ACROSS THE TRI CITIES AS MAIN TROF APPROACHES, WE WILL INCREASE OUR PRECIP TOWARD SCATTERED SNOW SHOWERS WITH WEST FLOW OFF LAKE MICHIGAN AND COLDER TEMPS ACROSS THIS PART OF THE LAKE AND CONVERGENCE INCREASING IN THE LOWER LEVELS.

TUESDAY... TROF PROGRESSES ACROSS THE STATE WITH LAKE MICHIGAN CONTRIBUTION TO SEE SCATTERED SNOW SHOWERS CWA-WIDE. ACCUMULATIONS WILL BE ON THE LIGHT SIDE BUT STILL SOME CONCERN WITH LAKE EFFECT BAND TRYING TO MOVE INTO M59/I94 CORRIDOR. INVERSION HEIGHTS ARE FORECAST TO CLIMB ABOVE 5K FEET BUT 1000-850 WIND MAGNITUDE OF 20-25KTS WOULD RESULT IN LESS TIME SPENT OVER THE WATER DESPITE DELTA T/S INTO THE MIDDLE TEENS. WE WILL CONTINUE TO MONITOR TRENDS AS, INTERESTINGLY, ETA-XX CONVERGENCE FIELDS HINT AT A "GOOD" BAND ACROSS THE HEART OF THE CWA.

TUESDAY NIGHT... SHORT WAVE RIDGING AND DRIER COLUMN WILL BRING AN END TO THE PRECIP. WITH ANTI-CYCLONIC SFC FLOW...AND DRIER AIR ALOFT...THINK WE SHOULD BE ABLE TO SEE SOME BREAKS IN THE CLOUD COVER OVERNIGHT. WITH SURFACE DEWPOINTS EXPECTED AROUND OR BELOW 10F, WE SHOULD BE ABLE TO DROP OFF INTO THE MID TEENS.

WEDNESDAY... MODEL TRENDS WITH NEXT WAVE CONTINUE TO HAVE PROBLEMS AS THIS WAVE IS CURRENTLY ACROSS ALASKA. WHILE NOAA AIRCRAFT HAVE DONE SOME DROPSONDES JUST SOUTH OF ALASKA HELPING WITH MODEL INITIALIZATIONS, WE STILL HAVE A VARIETY OF SOLUTIONS. WE WILL CONTINUE WITH A DRY FORECAST FOR NOW WITH SHORT WAVE RIDGING REMAINING NEARBY.

REMAINDER OF THE FORECAST GRIDS REMAINS INTACT WITH NO CHANGES.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...GALE WARNING LAKE HURON AND ST CLAIR TODAY.

&&

$$

BGM

EXPERIMENTAL GRAPHICAL FORECASTS ARE AVAILABLE ONLINE AT HTTP://WWW.CRH.NOAA.GOV/DTX (ALL LOWER CASE)



PORTION OF THIS VORT LOBE HAS ALREADY PUSHED WELL E OF FA SO WILL ONLY MENTION CHC FLRYS IN EXTREME NERN IL WHERE SRN EDGE OF THICKER LYRD CLOUDS ASSD WITH WI VORT CENTER MAY CLIP THIS SMALL PORTION OF AREA THIS MRNG. OTRW LOWER STRATOCU DECK NOW OVR RGN EXTENDS BACK TO A RWF-FOD-DSM-30I LINE AND IS CLEARING EWD ARND 20 KTS. WITH SFC ANAYLSES SHOWING PRESRR ACROSS AREA...RESULTING FROM FAIRLY STG MID LVL SUBSIDENCE IN WAKE OF VORT LOBE...EXPECT CLOUD DECK NO OVR FA TO ERODE FROM W THIS AFTN WITH SKIES CLRG PRETTY MUCH BY THIS EVENING.

WX TREND NXT SVRL DAYS WILL BE TO CONT TO HAVE WEAK CLIPPER TYPE VORT LOBES ROTG SEWD ARND LARGE POLAR VORTEX OVR ERN CAN. EXPECT INCRS IN CLOUD COVR AND CHC OF FLRYS WITH THESE PASSAGES...TUES... THEN AGAIN WED INTO WED NGT. THE LATTER SYS LOOKS A LTL STRONGER AS IT MOVES THRU AND EVEN HAS A SFC REFLECTION IN THE FORM A WEAK LO PRES THAT PASSES JUST S OF FA WED NGT BASED ON LATEST GFS RUN. THEREFORE WILL HAVE LO CHC POPS FOR LGT SNW WITH THIS SYS. MODEST LO LVL WARM ADVECTION WITH THIS AS WELL...BUT STILL DON/T THINK MUCH OF THIS SYS AS AMS WILL RMN VERY DRY AND DESPITE DECENT LOOKING H5 SUPPORT...DOUBT THIS WILL BE ENUF TO COMPENSATE FOR LARGE COND PRESSURE DEFICITS. GENLY DRY WX INTO EXTENDED PERIOD WITH PUSH OF MODIFIED MP AIR FCST TO ARRIVE ABOUT FRI.

MERZLOCK

&&

.LOT...WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LK MI...GALE WARNING FOR ALL OF LAKE MICHIGAN THROUGH 18Z.

&&

$$



.UPDATE...

ONE UPDATE ALREADY SENT OUT AT 835 AM THIS MORNING TO RAISE TEMPS AND REMOVE POPS. DON'T FORESEE ANY OTHER SIGNIFICANT UPDATES. HOWEVER...MAY HAVE TO BUMP TEMPERATURES UP A LITTLE MORE...AS THERE MAY BE SOME PEAKS OF SUN ACROSS THE SOUTHERN HALF OF THE CWA. CURRENT THINKING IS ANY PEAKS OF SUN WILL BE OFFSET BY SOME WEAK LOW LEVEL COLD ADVECTION. AT THE PRESENT TIME...TEMPERATURE ARE IN THE LOW TO MID 30S THROUGHOUT SOUTHEAST MICHIGAN.

AS FAR AS THE WINDS GO... WIND GUSTS TO 40 MPH IS WORKING OUT VERY WELL. HERE ARE A FEW WIND GUSTS AT 15Z: TTF 38 MPH MBS 35 MPH DTW 33 MPH ADG 31 MPH BAX 29 MPH

LAPS DATA INDICATING THE TIGHT THREE HOUR ISALLOBARIC PRESSURE COUPLET NOW WORKING THROUGH LOWER MICHIGAN. THE STRONGEST WINDS ARE RIGHT ALONG THE SURFACE TROUGH OVER WESTERN LOWER MICHIGAN (WIND GUST OF 40 MPH RECORDED AT GRR). THIS THERMAL TROUGH WILL CONTINUE TO ADVANCE EASTWARD AND SLOWLY WEAKEN DURING THE AFTERNOON. THUS...NO CONCERNS FOR WIND ADVISORY CRITERIA HERE IN SOUTHEAST MICHIGAN. STILL...COULD SEE A ISOLATED GUST IN THE 40 TO 45 MPH RANGE.

SF

.DISCUSSION ISSUED AT 305 AM... TROF CONTINUES TO CARVE ITSELF OUT ACROSS THE CENTER OF NOAM WITH LEAD 300MB JET ADVANCING NORTH ACROSS THE STRAIGHTS THIS MORNING WITH RIGHT ENTRANCE REGION ACROSS LAKE MICHIGAN. SHORT WAVE EMBEDDED WITHIN THE FLOW WAS TRACKING NORTHEAST TOWARD THE U.P. WITH WEAKENING SUBSIDENCE NOTED ON THE H2O VAPOR LOOP TRENDS. AT THE SURFACE, COLD FRONT WAS MAKING PROGRESS ACROSS THE MISSISSIPPI RIVER VALLEY WITH CYCLONIC BULGE NEAR KLSE AT 06Z. RADAR REFLECTIVITIES SHOW A NARROW LINE OF SNOW FROM NEAR KORD...EXTENDING ACROSS LAKE MICHIGAN...AND MOVING EAST NEAR 30 KTS. THE SOUTHERN HALF OF THIS ACTIVITY CONTINUES TO WEAKEN AND WARMING TEMPS PER IR SATELLITE CHANNEL. GRADIENT REMAINS TIGHT ACROSS THE STATE THIS MORNING AND WITH THE PASSAGE OF COLD FRONT...WIND GUSTS ACROSS IOWA WERE RUNNING CLOSE TO 35 KTS AS ISALLOBARIC RISE COMPONENT OF 4MBS/3HRS. THIS WILL BE OUR MAIN ISSUE TODAY.

TODAY... FIRST ON OUR DOCKET WILL BE THE SNOW. RUC AND LOCALLY PRODUCED ETA-XX HAVE AN EXCELLENT HANDLE THUS FAR WITH MAIN ISENTROPIC LIFT ON THE 290K SURFACE TO OCCUR BETWEEN 12-15Z. THE LOWEST CPD/S REMAIN ALONG AND NORTH OF I69 BUT WITH MAIN DYNAMICS LIFTING WELL NORTH OF THE REGION...WOULD EXPECT THIS ACTIVITY TO DECREASE IN INTENSITY AS IT PROGRESSES ACROSS THE CWA. FURTHER SOUTH, IT WILL BE TOUGH TO SEE ANY FLAKES FALL WITH CPD/S ABOVE 50MBS AND AFOREMENTIONED DEPARTING DYNAMICS. TEMPERATURES APPEAR TO BE FINALLY COME IN LINE WITH OUR CURRENT GRIDS (UNLIKE THE 40S WE WERE SEEING THIS TIME YESTERDAY). TRAJECTORY FORECASTS ORIGINATE FROM CENTRAL ILLINOIS WHERE HIGHS WERE IN THE MID 30S, HOWEVER, THESE PARCELS WILL HEAD ACROSS SNOWPACK COMBINING WITH CLOUD COVER TO HOLD BACK TEMPS FROM UPPER 20S NORTH TO AROUND FREEZING SOUTH. MODELS SUGGEST LAYER MAY DRY OUT ENOUGH SOUTH OF THE DTW-ARB LINE FOR SOME BREAKS IN THE CLOUD COVER BUT REMAIN MOCLOUDY. NOW, MAIN CONCERN IS WINDS AND IN A NUTSHELL, BELOW ADVISORY CRITERIA. BUFKIT MOMENTUM TRANSFER EQUATIONS POINT TOWARD 40KTS WHICH IS DOWN FROM PREVIOUS RUNS...AND WILL LIKELY BE A LITTLE BIT LESS. WHILE ISENTROPIC DOWNGLIDE DOES OCCUR...CROSS SECTIONS PARALLEL TO THE THETA FIELD DO NOT INDICATE CRASHING THETA SURFACES INTO THE GROUND LIMITING MIXING POTENTIAL. FURTHERMORE, H2O VAPOR LOOPS TRENDS SHOW SUBSIDENCE WEAKENING WITH TIME AND LIFTING NORTH WITH WAVE. WHILE GUSTS TO 40 MPH ARE EXPECTED...THIS IS BELOW WIND ADVISORY CRITERIA.

TONIGHT... COLUMN MOISTENS UP ONCE AGAIN WITH COLD ADVECTION OVER LAKE MICHIGAN AS MAIN TROF AXIS SLIDES INTO THE STATE. SOME INDICATION OF LEAD WEAK SHORT WAVE NOW OVER THE NORTHERN PLAINS MAY BRING A BRIEF SHOT OF LIFT AS SEEN IN THE WEAK DPVA FIELDS. THERMAL FIELDS ALSO RESPOND SOMEWHAT WITH WEAK, YET EVIDENT, Q-VECTOR CONVERGENCE ACROSS THE REGION (MAINLY SOUTHERN HALF). EITHER WAY, WE WILL CONTINUE WITH CHANCE OF LIGHT SNOW SHOWERS. LATE TONIGHT, ACROSS THE TRI CITIES AS MAIN TROF APPROACHES, WE WILL INCREASE OUR PRECIP TOWARD SCATTERED SNOW SHOWERS WITH WEST FLOW OFF LAKE MICHIGAN AND COLDER TEMPS ACROSS THIS PART OF THE LAKE AND CONVERGENCE INCREASING IN THE LOWER LEVELS.

TUESDAY... TROF PROGRESSES ACROSS THE STATE WITH LAKE MICHIGAN CONTRIBUTION TO SEE SCATTERED SNOW SHOWERS CWA-WIDE. ACCUMULATIONS WILL BE ON THE LIGHT SIDE BUT STILL SOME CONCERN WITH LAKE EFFECT BAND TRYING TO MOVE INTO M59/I94 CORRIDOR. INVERSION HEIGHTS ARE FORECAST TO CLIMB ABOVE 5K FEET BUT 1000-850 WIND MAGNITUDE OF 20-25KTS WOULD RESULT IN LESS TIME SPENT OVER THE WATER DESPITE DELTA T/S INTO THE MIDDLE TEENS. WE WILL CONTINUE TO MONITOR TRENDS AS, INTERESTINGLY, ETA-XX CONVERGENCE FIELDS HINT AT A "GOOD" BAND ACROSS THE HEART OF THE CWA.

TUESDAY NIGHT... SHORT WAVE RIDGING AND DRIER COLUMN WILL BRING AN END TO THE PRECIP. WITH ANTI-CYCLONIC SFC FLOW...AND DRIER AIR ALOFT...THINK WE SHOULD BE ABLE TO SEE SOME BREAKS IN THE CLOUD COVER OVERNIGHT. WITH SURFACE DEWPOINTS EXPECTED AROUND OR BELOW 10F, WE SHOULD BE ABLE TO DROP OFF INTO THE MID TEENS.

WEDNESDAY... MODEL TRENDS WITH NEXT WAVE CONTINUE TO HAVE PROBLEMS AS THIS WAVE IS CURRENTLY ACROSS ALASKA. WHILE NOAA AIRCRAFT HAVE DONE SOME DROPSONDES JUST SOUTH OF ALASKA HELPING WITH MODEL INITIALIZATIONS, WE STILL HAVE A VARIETY OF SOLUTIONS. WE WILL CONTINUE WITH A DRY FORECAST FOR NOW WITH SHORT WAVE RIDGING REMAINING NEARBY.

REMAINDER OF THE FORECAST GRIDS REMAINS INTACT WITH NO CHANGES.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...GALE WARNING LAKE HURON AND ST CLAIR TODAY.

&&

$$

BGM

EXPERIMENTAL GRAPHICAL FORECASTS ARE AVAILABLE ONLINE AT HTTP://WWW.CRH.NOAA.GOV/DTX (ALL LOWER CASE)