Forecast Discussions mentioning "ACARS", "MDCRS", or "AIRCRAFT" received at FSL on 01/08/03


AREA FORECAST DISCUSSION
NWS DODGE CITY KS
AFDDDC 246 PM CST TUE JAN 7 2003

DAYS 1-2...

THE MAIN FORECAST CONCERN FOR THE SHORT TERM IS TEMPERATURES, HIGHS TOMORROW AND HOW MUCH THINGS COOL FOR THURSDAY.

WATER VAPOR LOOP SHOWS UPPER LOW CONTINUING TO SPIN OVER BAJA CALIFORNIA, WHILE A RIDGE AMPLIFIES IN THE WESTERN CONUS. AT THE SURFACE, HIGH PRESSURE OVER TX HAS BROUGHT DOWNSLOPING WESTERLY FLOW TO THE CENTRAL PLAINS, ALLOWING TEMPERATURES TO WARM INTO THE UPPER 50S AND 60S SO FAR. LOOKING UPSTREAM, 850 MB TEMPERATURES A QUITE TOASTY ACROSS THE NORTHERN ROCKIES, WITH ALBERTA REPORTING A WHOPPING 18 DEGREES C AT 12Z THIS MORNING.

DIFFERENCES IN MODEL INITIALIZATION THIS MORNING AMONG THE SHORT TERM MODELS WERE VERY SLIGHT. ALL WERE SLIGHTLY OFF IN CATCHING THE ORIENTATION OF A 150 KT JET OFF OF THE NORTHWEST COAST, WITH THE ETA BEING CLOSEST TO REALITY. ALL THE MODELS AGREE ON TAKING THE RIDGE INTO THE WESTERN PLAINS OVERNIGHT. WITH WARM AIR ADVECTION THROUGHOUT MOST OF THE ATMOSPHERE TONIGHT, ALONG WITH DOWNSLOPING WINDS THROUGH TOMORROW, IT DEFINATELY WILL GET VERY WARM TOMORROW. THE QUESTION IS HOW WARM. ACCORDING TO THE ETA, 850 MB TEMPERATURES WILL MAX OUT AT 18 C TOMORROW AFTERNOON, WHILE THE AVN AND NGM ARE SLIGHTLY COOLER. MIXING THIS DOWN TO THE SURFACE AT DDC, THE ETA HAS 74 F FOR A HIGH, WITH 71 FROM THE NGM AND 68 FROM THE AVN. WITH SUNNY SKIES AND PLENTY OF MIXING, WE SHOULD HAVE NO TROUBLE REACHING CLOSE TO 70 DEGREES, SO I BUMPED UP HIGHS A DEGREE OR SO ACROSS THE CWA. DON'T THINK WE WILL SEE RECORD HIGHS IN PLACES LIKE LBL AND EHA, WHERE LAST YEAR IT GOT UP INTO THE MID TO UPPER 70S, BUT A FEW LOCATIONS IN THE WEST CENTRAL CWA COULD SEE RECORDS BROKEN.

AFTER ALL THE WARMING ON WEDNESDAY, THE MODELS ALL BRING A COLD FRONT THROUGH SLIGHTLY BEFORE MIDNIGHT ON WEDNESDAY NIGHT. WITH MOISTURE LACKING THROUGHOUT MOST OF THE ATMOSPHERE, THE FRONTAL PASSAGE WILL BE DRY, WITH ONLY A FEW CLOUDS AND WINDS SHIFTING TO THE NORTH. STRONG CAA SETS IN FOR MOST OF THE DAY ON THURSDAY, WHICH SHOULD KNOCK US BACK DOWN TO NEAR NORMAL HIGHS FOR THIS TIME OF YEAR.

DAYS 3-7...

THE EXTENDED FCST WILL BE MARKED WITH STRONG PERSISTENT BLOCK FEATURE CENTERED AROUND 130W, EXTENDING NORTHWARD TO THE POLAR LATITUDES OF THE NORTHERN YUKON AND NORTHWEST TERRITORIES. THE 12Z DIAGNOSTIC DATA SUGGEST THE JET STREAK CROSSING THE BRITISH COLUMBIA COAST THIS MORNING WAS UNDER INITIALIZED BY ALL GLOBAL SPECTRAL MODELS...WHERE ACARS PLOTS SUGGEST 170 KTS VERSUS INITIALIZED 145 KTS. THIS MIGHT SUGGEST MORE RAPID EVOLUTION TO OMEGA BLOCK TYPE REGIME. THE OTHER SIGNIFICANT JET OVER THE NORTHERN PACIFIC ALONG 35N LATITUDE APPEARS TO BE PICKED UP WELL BY ALL GLOBAL SPECTRAL MODELS, DESPITE LACK OF ACTUAL DATA TO BACK THIS UP OTHER THAN SATELLITE. THIS COMPLICATED PATTERN WILL ALSO BE MARKED WITH UNDERCUTTING SHORTWAVE TROUGHS WHICH WILL AFFECT THE HIGH PLAINS THIS WEEKEND. THE PRIMARY FEATURE THAT WOULD HAVE INFLUENCE ON SENSIBLE WEATHER IS CURRENTLY SPINNING OUT OVER THE OPEN WATERS NEAR 33N/137W. IT APPEARS MUCH LESS LIKELY THAT THE PREVIOUSLY THOUGHT SURGE OF ARCTIC AIR WILL INVADE WESTERN KANSAS, OTHER THAN A GLANCING BLOW. THE CURRENT GOING FORECAST ALREADY REFLECTS THIS WITH HIGHS AT OR SLIGHTLY BELOW CLIMO THROUGH THE PERIOD. WILL NOT MAKE ANY SIGNIFICANT CHANGES TO TEMPERATURES IN THIS PACKAGE.

THE OVERCAST FORECAST FOR FRI/SAT STILL LOOKS ON TRACK AS COLD AIR OOZES DOWN THE HIGH PLAINS WITH LEESIDE LOW PRESSURE DEVELOPING AHEAD OF UNDERCUTTING PACIFIC SYSTEM. WITH THE LACK OF ANY AMPLIFICATION OF THIS SHORTWAVE FEATURE, PCPN CHANCES LOOK NEXT TO NIL.

AS THE OMEGA BLOCKING BREAKS DOWN EARLY NEXT WEEK, LARGE PACIFIC LONGWAVE TROUGH WILL TEND TO SLIDE UNDERNEATH THE POLAR ANTICYCLONE LOCATED OVER THE BEAUFORT SEA. SHORTER WAVELENGTH CIRCULATIONS WITHIN THIS NORTHEAST PACIFIC VORTEX WOULD BEGIN TO INFLUENCE THE WESTERN CONUS, AS DEPICTED BY LATEST GFS SOLUTIONS AROUND HOUR 156 TO 180. INTERESTINGLY ENOUGH, THE GFS TAKES ONE OF THESE SHORTER WAVELENGTH DISTURBANCES AND DIGS IT INTO THE SOUTHWEST STATES. WITH DECENT BAROCLINICITY ALREADY IN PLACE ACROSS THE PLAINS, A SCENARIO DEPICTED BY THE GFS WOULD RESULT IN SIGNIFICANT OVERRUNNING PCPN EVENT. AT THIS TIME, SHORT WAVELENGTH PROGS BEYOND DAY 7 ARE SIMPLY WHITE NOISE IN THE PLANETARY SCALE PATTERN, ESPECIALLY AFTER THE BREAKDOWN OF SUCH STRONG BLOCKING. WILL WORD THE 8 TO 10 DAY OUTLOOK NEAR NORMAL FOR BOTH PCPN AND TEMPS WITH SO MUCH UNCERTAINTY BY MID-NEXT WEEK.

PRELIMINARY GUIDANCE FOR COORDINATION ONLY. OFFICIAL FORECASTS ARE CONTAINED WITHIN THE DODGE CITY ZONE FORECAST.

DDC 31 72 30 42 / 0 0 0 0 GCK 29 71 29 42 / 0 0 0 0 EHA 31 73 31 45 / 0 0 0 0 LBL 29 71 31 45 / 0 0 0 0 HYS 28 71 28 41 / 0 0 0 0 P28 32 70 34 44 / 0 0 0 0

.DDC...NONE.

RITTERLING/UMSCHEID




AREA FORECAST DISCUSSION
NWS CHICAGO IL
AFDCHI 230 AM CST WED JAN 8 2003

DISCUSSION RE GRIDS/ZONES FORECASTS...

NO SIGNIFICANT CHANGES TO CURRENT FCSTS ANTICIPATED. MAIN CHALLENGE IS TEMP TRENDS...ESPECIALLY TODAY...AND THEN WITH CFP TONIGHT AND ANOTHER THU NIGHT.

WARMEST 850MB TEMPS AT 00Z WERE FROM SRN SASKATCHEWAN SE ACROSS THE MO RIVER VALLEY TO MID MS VALLEY. CORE OF WARM AIR FCST OVER CENTRAL PLAINS AT 12Z THEN OVER SRN PLANS...OZARKS...LOWER OH VALLEY BY 00Z THU. COLDER AIR OVERSPREADS NRN PLAINS AND UPPER MIDWEST AS JET AXIS SINKS S OF 49TH PARALLEL INTO GREAT LAKES TODAY AND TONIGHT.

WITH VERY STRONG LOW LEVEL INVERSION H8 TEMPS NOT BEST PREDICTOR OF SFC TEMPS AND WILL USE ETA 925MB TEMPS AS GUIDELINE. ACARS DATA SHOWS TRENDS FORECAST BY ETA VERIFYING...WITH 925 MB TEMPS FALLING TO +11C AT MSP AND RISING TO +13 AT RFD & +11 AT ORD. 925 TEMPS +13 TO +15 ACROSS AREA AT 12Z FALL TO +9 TO + 11 BY 18Z AND FURTHER TO + 6 TO +8 BY 00Z. EXPECT FAIRLY QUICK RISE IN TEMPS AFTER SUNRISE...THOUGH NEXT BATCH OF THICKER CI SEEN MOVING SE OUT OF NRN PLAINS WILL BE OVER AREA AND CUT WEAK LOW ANGLE WINTER SUN. TEMPS THEN EXPECTED TO LEVEL OUT AROUND MIDDAY IN LOWER AND MID 50S.

TROF/DEVELOPING COLD FRONT MOVES THRU THIS EVE SETTING UP STRONG CAA TONIGHT...WITH SECOND CFP THU NIGHT AS UPPER JET AXIS SINKS S INTO NRN IL. CONT CAA FRI AS UPPER TROF ROTATES AROUND ERN CANADA VORTEX THRU THE GREAT LAKES.

FAIR SKIES WITH ONLY SCT TO BKN CI TODAY THRU TONIGHT. MODELS BRING HIER LOW LEVEL RH DOWN OUT OF CANADA WITH COLD AIR AND OVERSPREADS AREA THU MORNING. COULD BE A FEW FLURRIES THEN BUT GREATEST BETTER CHANCE OF -SHSN WILL BE THU NIGHT AS MINOR SHORT WAVE ZIPS THRU. LINGERING CHC OF FLURRIES FRI AS ARCTIC AIR ARRIVES.

.CHI...NONE

TRS




AREA FORECAST DISCUSSION
NWS CHICAGO IL
AFDCHI 530 AM CST WED JAN 8 2003

AVIATION DISCUSSION FOR 12Z TAFS...

WARM MARITIME WESTERLIES HOLDING MSTR WELL WITH LACK OF CLOUD COVER AVAILABLE EXCEPT FOR SOME BKN CI IN WHAT MIGHT BE SOME VERY WEAK UPR LVL TROUGHING IN OTHERWISE STRAIGHT NWLY FLOW AT 5H. WINDS AT SFC ARE PRIMARY FOCUS AGAIN TODAY. SHARP INVERSION STILL INTACT WITH 40 KT 850 WINDS NOT LIKELY TO MIX DOWN THRU IT DURING THE DAY. BUT WILL FOLLOW YESTERDAY'S VALUES WITH GUSTS GENERALLY TO 25 KT FROM THE WEST.

POLAR VORTEX HOWEVER COMES DIVING SOUTH THRU HUDSON BAY TODAY AND DEEPENING SFC FRONT ACROSS THE LAKES. THIS FRONT COMES SWINGING THRU NRN IL THIS EVENING WITH WINDS SHIFTING MORE NORTHWEST AND COLD ARCTIC AIR SPILLING SOUTH INTO THE AREA. INVERSION SUFFERS TONIGHT AS COLD AIR COOLS COLUMN AND DOWNSLOPE MIXING FROM STRONG WINDS ALOFT LIKELY TO INCREASE WIND SPEED TO 30 KT TNGT. BOTH ETA AND AVN HINTING AT CONDENSATING LOW LVL MSTR BLO 3K AFTER 12Z THURSDAY BUT NO LOW LVL SC APPARENT BEFORE THEN.

RLB

DISCUSSION RE GRIDS/ZONES FORECASTS...

NO SIGNIFICANT CHANGES TO CURRENT FCSTS ANTICIPATED. MAIN CHALLENGE IS TEMP TRENDS...ESPECIALLY TODAY...AND THEN WITH CFP TONIGHT AND ANOTHER THU NIGHT.

WARMEST 850MB TEMPS AT 00Z WERE FROM SRN SASKATCHEWAN SE ACROSS THE MO RIVER VALLEY TO MID MS VALLEY. CORE OF WARM AIR FCST OVER CENTRAL PLAINS AT 12Z THEN OVER SRN PLANS...OZARKS...LOWER OH VALLEY BY 00Z THU. COLDER AIR OVERSPREADS NRN PLAINS AND UPPER MIDWEST AS JET AXIS SINKS S OF 49TH PARALLEL INTO GREAT LAKES TODAY AND TONIGHT.

WITH VERY STRONG LOW LEVEL INVERSION H8 TEMPS NOT BEST PREDICTOR OF SFC TEMPS AND WILL USE ETA 925MB TEMPS AS GUIDELINE. ACARS DATA SHOWS TRENDS FORECAST BY ETA VERIFYING...WITH 925 MB TEMPS FALLING TO +11C AT MSP AND RISING TO +13 AT RFD & +11 AT ORD. 925 TEMPS +13 TO +15 ACROSS AREA AT 12Z FALL TO +9 TO + 11 BY 18Z AND FURTHER TO + 6 TO +8 BY 00Z. EXPECT FAIRLY QUICK RISE IN TEMPS AFTER SUNRISE...THOUGH NEXT BATCH OF THICKER CI SEEN MOVING SE OUT OF NRN PLAINS WILL BE OVER AREA AND CUT WEAK LOW ANGLE WINTER SUN. TEMPS THEN EXPECTED TO LEVEL OUT AROUND MIDDAY IN LOWER AND MID 50S.

TROF/DEVELOPING COLD FRONT MOVES THRU THIS EVE SETTING UP STRONG CAA TONIGHT...WITH SECOND CFP THU NIGHT AS UPPER JET AXIS SINKS S INTO NRN IL. CONT CAA FRI AS UPPER TROF ROTATES AROUND ERN CANADA VORTEX THRU THE GREAT LAKES.

FAIR SKIES WITH ONLY SCT TO BKN CI TODAY THRU TONIGHT. MODELS BRING HIER LOW LEVEL RH DOWN OUT OF CANADA WITH COLD AIR AND OVERSPREADS AREA THU MORNING. COULD BE A FEW FLURRIES THEN BUT GREATEST BETTER CHANCE OF -SHSN WILL BE THU NIGHT AS MINOR SHORT WAVE ZIPS THRU. LINGERING CHC OF FLURRIES FRI AS ARCTIC AIR ARRIVES.

.CHI...NONE

TRS