AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 915 PM EST MON JAN 3 2000 CURRENT MOSAIC RADAR LOOP AGREES WELL WITH LATEST RUC PROGS IN TERMS OF TIMING THE PROGRESS OF THE SQUALL LINE CURRENTLY EXTENDING NE FROM JUST W OF NEW ORLEANS AND THROUGH SRN MS AND BIRMINGHAM. BELIEVE WINDS OVER OUR COASTAL WATERS WILL STAY JUST BELOW SMALL CRAFT ADVISORY CRITERIA AS PRESSURE GRADIENT OVER THE WATER STAYS LOOSE WHILE STRONG UPPER VORT MAX SHEARS NE TOWARDS THE GREAT LAKES. DESPITE SOME BR REPORTED HERE AT KTLH AND A COUPLE OTHER SITES... AGREE WITH PREVIOUS SHIFT THAT BRISK BOUNDARY LAYER WINDS WILL MITIGATE FOG THREAT. MAY BUMP UP LOW TEMPERATURES IN SOME ZONES WITH GOOD THETA-E ADVECTION N INTO OUR CWA AHEAD OF APPROACHING COLD FRONT. ALSO...MAY FINE TUNE TIMING OF PRECIPITATION FOR WRN ZONES. NO OTHER CHANGES ARE PLANNED AT THIS TIME. INPUT IS ALWAYS WELCOME. .TLH... FL...NONE. AL...NONE. GA...NONE. TJT fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSONVILLE FL 810 PM EST MON JAN 4 2000 SFC RIDGING OVER THE AREA IS SHIFTING E AS COLD FRONT OVER LA AND AL CONTINUES TO MOVE TOWARD THE EAST COAST. BY ABOUT 12Z...THE FRONT SHOULD JUST BE ENTERING THE FL PANHANDLE AND ARRIVE IN CWA BY EARLY TUESDAY EVENING. FOR TONIGHT...PLENTY OF LOW LEVEL MOISTURE AND GOOD NOCTURNAL COOLING SHOULD PRODUCE SOME AREAS OF DENSE FOG. BOTH ETA AND RUC MODELS SHOW LOW LEVEL WINDS INCREASING TONIGHT. WITH SFC WINDS PICKING UP EXPECT FOG TO BE LESS OF A PROBLEM THAN PREVIOUS NIGHTS. STILL THINK MVFR VIS CONDITIONS DEFINITELY POSSIBLE AND IS REFLECTED IN TAFS. LOW LEVEL MIXING SHOULD ALSO KEEP TEMPS LITTLE WARMER THAN LAST NIGHT SO UPPER 50S LOOKS GOOD FOR NOW. RADAR LOOP SHOWS SHOWER ACTIVITY MOVING N IN OFFSHORE COASTAL WATERS AND THIS IS ASSOCIATED WITH THETA-E RIDGE AND LOW LEVEL CONVERGENCE OVER WARM GULF STREAM WATERS. FOR ZONES...LITTLE CHANGES ANTICIPATED. MARINE...SAUF1 C-MAN SITE SHOWS WINDS ESE INCREASING TO 11 KT AND GRAYS REEF NOW E 8G11KT AND SEAS 2 FT. SOME ADJUSTMENT MAY BE NEEDED TO WIND DIRECTION DUE TO COASTAL TROUGH THAT APPEARS IN WIND FIELDS. MESO-ETA QUICKLY WEAKENS THIS TROUGH HOWEVER SO WINDS SHOULD STILL INCREASE TO SCEC CRITERIA...THUS NO CHANGE TO COASTAL WATERS HEADLINE. .JAX... GA...NONE. FL...NONE. ARS fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PEACHTREE CITY GA 930 EST MON JAN 3 2000 FROM 00Z FFC RAOB AIR STILL RATHER DRY AND STABLE OVER GEORGIA WITH HELICITY AROUND 180 BUT AIR MUCH MORE UNSTABLE AND HIGHER HELICITY AT BMX. LATEST ANALYSIS AND RUC SHOW MOST UNSTABLE AIR REMAINING OVER ALABAMA THROUGH 09Z. LEADING EDGE OF PRECIP SEEMS TO WEAKEN OVER NORTHEAST ALABAMA AS IT MOVES INTO MORE STABLE AIR. ANTICIPATE CONVECTION MOVING INTO NORTHWEST CORNER AROUND MIDNIGHT...BUT IN A MUCH WEAKENED STATE. CURRENT FORECAST TEMPERATURES AND POPS APPEAR TO FIT THE SITUATION WELL SO NO UPDATES ANTICIPATED. .ATL..NONE. ga AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 300 PM CST MON JAN 3 2000 18Z SFC ANALYSIS DEPICTS 1004 LOW DEVELOPING ACRS SOUTHWEST MO... CLOSE TO 12Z ETA AND LATEST RUC. BEST PRESSURE FALLS OCCURRING TO THE NORTHEAST OF IT ACRS EAST CENTRAL MO AND ACRS CENTRAL IL. SFC-H85 BAROCLINICITY/THERMAL THONG/ ALSO STRETCHED ALONG SAME ROUTE... SHOWING THE WAY OF SFC WAVE PROPAGATION. AGAIN LATEST RUC AND ETA SEEM TO HAVE BETTER HANDLE OF PROJECTED PATHWAY AND WILL FOLLOW. NORTHEAST SFC WINDS BACKING TO NORTH ACRS NORTHERN HALF OF CWA IN RESPONSE TO DEEPENING SYSTEM. BLUE RIVER PROFILER SHOWING DEEPENING NORTHEAST FLOW APPROACHING THE H85 LEVEL...WHICH SHOULD ADVECT COOLER H85 TEMPS ACRS WI OVER DVN CWA SUPPORTING ALL SNOW. SFC OBS AND PHONE CALLS ALREADY REPORTING LIGHT TO MODERATE SNOW BREAKING OUT ACRS WEST CWA....TO GO ALONG WITH BLOSSOMING 88D IMAGERY. THIS INDICATES ISENTROPIC/INCREASING VERTICAL LIFT TAKING OFF ACRS PARTS OF CWA. ETA ALSO BETTER AT HANDLING DEFORMATION ZONE DEVELOPMENT ACRS EAST KS INTO NORTHWEST MO...AND BRINGS IT NORTHEAST ACRS MUCH OF CWA OVERNIGHT. SFC LOW SHOULD TRACK TO STL VCNTY BY 00Z...AND THEN PIVOT NORTHEAST TO A NORTH CENTRAL IN/SOUTHWEST LOWER MI POSITION AROUND 06Z TUE. THIS WOULD SUPPORT 130-150 NMI HEAVIER SNOW BAND PLACEMENT RULE ACRS CENTRAL POSITIONS OF DVN CWA... GENERALLY 50 MI OR SO EITHER SIDE OF THE MS RVR. REGIONAL/MOSAIC 88D LOOP DEFORMATION ZONE TRENDS CURRENTLY ACRS NORTHWEST HALF OF MO AND TAKING SFC LOW TRACK INTO ACCOUNT...SUPPORT THIS SCENARIO. H7 LOW ALSO PROGGED TO TRACK JUST WEST OF MS RIVER SUPPORTING HEAVIER SNOW BAND. THIS COMBINED WITH THE ALREADY OCCURRING ISENTROPIC SNOW ACRS AREA SUPPORT ONGOING WSW'S...AND WILL LIKELY ADD TO. MOST OR ALL OF CWA PROBABLY WILL BE UNDER WINTER STORM WARNING OR WINTER WX ADV FOR TONIGHT. ALSO...UPPER VORT MAX HANGING BACK ACRS OK WITH HEAVY SNOW EXTENDING ACRS KS...MAKES ME NERVOUS ABOUT EXTENDED SNOW EVENT OVERNIGHT. AS STATED BEFORE...CRITICAL/PARTIAL THICKNESSES AND ONGOING OBS SUPPORT ALL SNOW...EXCEPT ACRS EXTREME SOUTHEAST IA AND WEST CENTRAL IL. MODELS QUICKLY COOL THESE PARAMETERS ACRS THESE AREAS TO ALL SNOW CRITERIA JUST AFTER 00Z...BUT FEEL IT WILL GO QUICKER THAN THAT. AGREE WITH ILX THAT INITIAL WARM GROUND AND MARGINAL AMBIENT TEMPS WILL CUT BACK ON INITIAL ACCUMULATIONS...BUT CONTINUING SNOW FROM BAND EXTENDED WAY OUT SOUTHWEST COULD ACCUMULATE LATER TONIGHT TO ADVISORY CRITERIA. STRONG NORTH WINDS BLOWING IT AROUND...EVEN THOUGH IT MAY BE OF WET VARIETY...SUPPORT ADVISORY FOR TREACHEROUS CONDITIONS AS WELL. THIS SYSTEM WILL QUICKLY INGEST COLD AIR FROM THE NORTH AS BOUNDARY LAYER TO H85 TEMPS CRASH TONIGHT. AS FOR AMOUNTS AND AREA EXTENT... FEEL EARLIER WINTER STORM WARNING UPGRADE HAS GOOD HANDLE...BUT MAY EVEN ADD A TIER OF COUNTIES TO WEST. 290 TO 295 K GARCIA ANALYSIS AND AVERAGE-ADVECTED IN SPECIFIC HUMIDITIES SUPPORT 6 TO 8 INCHES ACRS CENTRAL CWA IF LIFT WAS TO LAST 12 HRS. BUT BEST LIFT PROGGED TO SHIFT NORTHEAST WITH SFC WAVE AFTER 02Z. MAIN DYNAMICS/POS OMEGAS THEN TAKE OVER AS DEFORMATION ZONE SWEEPS ACRS MUCH OF CWA. HEAVIEST SNOW LOOKS TO OCCUR WITH POS OMEGA BULLSEYE AND 90+ RH/S EXTENDED UP TO H5 MB FROM 00Z TO 06Z TUE. PARAMETERS IN THIS TIME ZONE FROM 00Z-04Z ACRS CENTRAL CWA ALSO SUPPORT DENDRITIC FLAKE SCENARIO WHICH COULD SUPPORT AT LEAST INCH/HOUR RATES. LOOKING AT H5-H3 POTENTIAL VORT AND H2 TEMP PROFILES...TROP FOLD AND THUS WARM POCKET EXTENDING TO AT LEAST 450 MB MAY ADD CYCLOGENESIS PUNCH...STRENGTHENING SFC LOW BEYOND PROGGED LEVELS. COOK METHOD/FOR WHAT ITS WORTH/ SUPPORTS UP TO 8 INCH AMOUNTS ACRS CWA. ALL IN ALL...WILL CONTINUE WINTER STORM WARNING FOR 4-8 INCH AMOUNTS ACRS ONGOING AREA TONIGHT...AND ADD A FEW COUNTIES EITHER SIDE. REST OF CWA TO BE UNDER WINTER WX ADVISORY FOR LESSER AMOUNTS. ...EXTENDED...THU-FRI-SAT... QUICK LOOK AT EXTENDED...MRF AND EUROPEAN BRING NORTHERN STREAM UPPER LEVEL WAVE ACRS THE NORTH CENTRAL CONUS THROUGH THU MORNING... WITH EURO FURTHER NORTH WITH SFC SYSTEM WELL INTO CANADA...AND THUS LESS CHANCE OF PRECIP. MRF FURTHER SOUTH WITH SFC SYSTEM INTO WESTERN GRT LKS BY 12Z THU...AND THUS BETTER CHANCE OF LIGHT SNOW ACRS NORTHERN HALF OF CWA ON THU. WILL LEAVE ONGOING CHANCE... ALTHOUGH MOISTURE AVAILABILITY AT QUESTION. TROUGH TO INDUCE SFC- H85 WARMING OUT AHEAD OF IT...BUT STILL FEEL FMR NUMBERS BIT WARM AND WILL TONE DONE...ESPECIALLY WITH PROJECTED SNOW COVER. BOTH MODELS COME UP WITH SPLIT FLOW REGIME AT END OF WEEK INTO THE WEEKEND...WITH NORTHERN STREAM ZONAL FLOW OFF OF THE PACIFIC NORTHWEST DEVELOPING ACRS UPPER MIDWEST. AFTER BRIEF COOL SHOT BEHIND DEPARTING TROUGH ON FRI...SOME MODERATION IN SFC-H85 TEMPS OCCURS OUT AHEAD OF NEXT VIGOROUS NORTH STREAM SYSTEM SKIRTING ACRS U.S./CANADIAN BORDER ON SAT. AGAIN EURO FURTHER NORTH IN IT/S SOLUTION HANDLING WAVE THAN THE MRF...BUT BOTH LOOK DRY FRI AND SAT AND WILL GO THAT WAY...ALTHOUGH MRF ADVERTISING LINGERING LIGHT SNOW AND FLURRIES FRI MORNING. COORDINATED WITH MKX...ARX...ILX...LSX...THANX. .DVN... IA...WINTER STORM WARNING FOR TONIGHT EAST OF A DBQ...TO IOWA CITY... TO WASHINGTON LINE. WINTER WX ADVISORY TO THE WEST. IL...WINTER STORM WARNING NORTHWEST IL FOR TONIGHT...WINTER WX ADVISORY FOR BUREAU...PUTNAM...AND WEST CENTRAL IL TONIGHT. MO...WINTER STORM WARNING TONIGHT FOR FAR NORTHEAST MISSOURI. JDH il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1020 PM EST MON JAN 3 2000 THINGS GENERALLY EVOLVING AS EXPECTED TONIGHT. 00Z SFC ANAL SHOWS 1000MB LOW OVER W INDIANA. THIS POSITION SLIGHTLY FARTHER EAST THAN ALL MODELS EXCEPT AVN AND RUC. KGRB 88-D SHOWING AREAS OF 28+DBZ RETURNS ACROSS E-CNTRL WI EXTENDING NE OVER PARTS OF LAKE MICHIGAN. SNOW HAS BEEN SLOW IN SPREADING NORTH INTO UPR MI...FIGHTING DRY ATMOSPHERE. MNM METARS HAVE SHOWN LOWER VIS SO SNOW HAS STARTED THERE...WITH CIGS CONTINUING TO LOWER ELSEWHERE. 00Z RAOBS SHOW 850MB TEMPS BEING HANDLED WELL BY MODELS FOR LAKE ENHANCEMENT/LES CONCERNS. GIVEN LATEST DATA AND TRENDS...EXPECT SNOW TO CONTINUE CREEPING NORTHWARD INTO CNTRL UPR MI. RUC DEPICTS 990MB LOW OVER LAKE HURON AT 12Z TUE. THIS MAY BE TOO DEEP...ALTHOUGH SUPPORT FROM IMPRESSIVE 100KT H5 JET NEAR ILX AT 00Z AND LOCATION OVER WARM LAKE SHOULD SUPPORT CONTINUED DEEPENING. RUC SHOWS MEASUREABLE PRECIP GETTING TO MQT AREA BETWEEN 03 AND 06Z. GENERALLY LIGHT AMOUNTS EXPECTED CNTRL AREAS...THOUGH THEY WILL BE ENHANCED IN HIGHER TERRAIN BY LAKE AND UPSLOPE FLOW. EASTERN COUNTIES WILL BE CLOSER TO STRONGER 700-300MB QVEC CONV/I295 LIFT/AND DEEPER MOISTURE SO ACCUMULATIONS WILL BE HIGHER THERE. ALGER COUNTY A BIT OF A PROBLEM SINCE IT IS ON W EDGE OF SYSTEM SNOW...AND NOT AS FAVORABLE FOR LAKE ENHANCEMENT WITH NE FLOW. WINDS WILL BE A FACTOR AS WELL WITH THIS SYSTEM WITH VERY TIGHT PRES GRAD. WILL THEREFORE MAINTAIN CURRENT HEADLINES...BUT DECREASE AMOUNTS SLIGHTLY OVER CENTRAL COUNTIES GIVEN LATE START TO SNOW AND LESS FAVORABLE FACTORS FOR SNOW. .MQT...SNOW AND BLOWING SNOW ADVISORY OVERNIGHT BARAGA-MQT-ALGER-LUCE- MNM-DELTA-SCHOOLCRAFT CO/S. GALE WARNING EAST HALF OF LAKE SUPERIOR LATE TNGT/EARLY TUES. JS mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 1035 AM CST MON JAN 3 2000 INCREASING EASTERLY FLOW HAS BROUGHT WIDESPREAD SC FIELD ACROSS ZONE FORECAST AREA THIS MORNING. WEAK SFC TROUGH HAS NUDGED ITS WAY INTO FAR WEST WITH WIDESPREAD -SN ACRS ERN SD SPREADING INTO AREA. ETH REPORTING -SN FOR ABOUT 1 HR. WILL BE FIGHTING AGAINST DRY MID LEVELS AS WELL. ADDED MENTION OF -FZDZ DUE TO SAID DRYING. PRECURSOR S/W PUSHING RAPIDLY NE INTO IL HELPING TO SHARPEN/DEEPEN TROUGH OVR CENTRAL US. SECOND VIGOROUS S/W OVR KS/OK REGION. CIRCULATION APPEARS ABT 100 MILES FARTHER NORTH THAN INDICATED BY MODEL GUIDANCE PER EXAMINATION OF WIND PROFILER NETWORK. STILL MAIN FORCING SHOULD SKIRT SOUTHEAST OF ZONE FORECAST AREA. RUC 290 THETA SURFACE SHOWS CONDENSATION PRESSURE DEFICITS DECREASING TO LESS THAN 20MB OF LIFT OVR SOUTH CENTRAL ZFA THROUGH EARLY AFT AND SPREADS TWD EAU VCNTY IN AFTN. MUCH MORE SIGGY UPGLIDE AND MOISTENING FTHR SE OVR IL/WI. KMPX 88-D SHOWING LARGER AREA OF WEAK RETURNS DEVELOPING OVR IA/MN BORDER AND SPREADING NWD. CRITICAL THICKNESSES FAVOR SOLID PRECIP BUT 12Z SOUNDINGS MORE IN LN WITH POSSIBLE -FZRA/-FZDZ SCENARIO UNTIL BETTER FORCING OR EVAPORATIVE COOLING TAKES OVER. MUCH COLDER AIR ATTACHED TO MORE NWLY SFC WIND FLOW OVR WRN ZFA WITH UPSTREAM TEMPS ONLY IN THE SINGLE DIGITS AND TEENS. HENCE DO NOT EXPC MUCH RECOVERY IN DXX AREA TODAY. MOST LKLY WL NEED TO CARRY MENTION OF -SN MOST AREAS TONIGHT AS MID LEVEL TROUGH AND MOIST COLD AIR ADVECTION SPREADS ACRS AREA. .MSP...NONE KAVINSKY mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO 448 AM CST MON JAN 3 2000 PESKY LITTLE SOUTHWEST LOW TAKING AIM ON CWA TDY. SFC DEEPENING OVR CNTL OK LAST FEW HRS WITH QUITE A BIT OF CNVTN ACR ERN OK NOSING INTO XTRM SW MO. THIS CNVTN APPRS TO BE FUELED BY DVRGNC AND 125 KT JET AT H3. EAX 88-D ALREADY BANGING SOME MID LVL RETURNS WITH THIS FEATURE SO XPCT ISOLD PCPN TO DVLP ARND DAYBRK. INTITIALLY SOUNDINGS SUGGEST PCPN BEGINNING AS -RA HOWEVER WITH LWR TROPOSPHERIC WET BULBS IN UPR 20S THINK THAT ALL -SN SHLD FALL IF ANY LIFT OF SIGNIFICANCE OCCURS. WORDED ALL ZNS TO READ PSBL -RA AT OUTSET THEN ALL -SN THROUGHOUT THE DAY. ALL MODELS LIFT THIS UPR LVL DVRGNC TO N OF FCST AREA BY 1800 UTC. BET 1800 UTC AND 0600 UTC MODELS FCST WEAK DEFORMATION ZN TO TRACK ACR CWA. AREA OF -SN SHOWING UP ON RADAR ATTM ACR S CNTL KS. PCPN APPRS TO BE LGT AND NOT VRY ORGANIZED ATTM HOWEVER AS SYS MVS FTHR N INTO BETTER BAROCLINIC ENVIRONMENT WOULD NOT BE SURPRISED TO SEE BETTER ENHANCEMENT. LATEST RUNS ETA/NGM AND RUC ALL SUGGEST STG ISENTROPIC LIFT IN 6 HR PRD BET 1800-2400 UTC ALG WITH SHALLOW LYR OF CSI JUST ABV H8. ALG XTRM SE PERIPHERY OF CWA ETA CROS SECT SHOWED WEAK ELEVATED CNVTN POT. ETA/NGM/RUC ALL BRING QUITE A BIT OF WATER NWRD WITH 4.0 GM/KG SPEC HUMIDITIES FCST TO PUNCH INTO RGN THIS PM. THINK THAT THIS WILL BE A SHORT LIVED EVENT ALG MAGNITUDE OF 6 HRS OR SO. VARIOUS EMPIRACLE RULES SUGGEST MAXIMUM POT SNOWFALL IN 6-7 INCH NEIGHBORHOOD. HOWEVER BASED ON QUICK FCST MVMNT AND LACK OF STG CNVGNC OF Q/QN OVR CWA AND NOT MUCH BETTER THAN STANDARD 10:1 RATIO XPTD DUE TO MOIST ENVIRONMENT WITH TEMPS NR OR JUST UNDR FRZG ISSUED SN ADVSY ALG MKC-IRK CORREDOR FOR 3-5 INCHES. STG CAA IN LWR TROPOSPHERE FCST THROUGHOUT THE DAY SUGGEST LTL OR NO TEMP RISE TDY SO WORDED TEMPS STEADY OF FALLING ALL ZNS. STAYED FAIRLY CLOSE TO GUIDANCE NUMBERS THRU FCST PRD XCPT FOR TUE NITE WENT SVRL CATS UNDR DUE TO XPCTD CLR SKIES AND FRESH SN CVR. HAD NO TIME TO LK AT XTND SO LEFT IN TACT. THANKS TOP/LSX/SGF/DMX/MLI FOR COORDINATION. .EAX... KS...SNOW ADVISORY FOR MONDAY FOR ZONES KSZ057...KSZ103>105. MO...SNOW ADVISORY FOR MONDAY FOR ZONES MOZ021>022...MOZ028>030... MOZ037>038...MOZ043>044. SNOW ADVISORY FOR THIS AFTERNOON THROUGH LATE TONIGHT FOR ZONES MOZ005>008...MOZ014>017...MOZ023>025...MOZ031>032. BODNER mo AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 1000 PM MON JAN 3 2000 STRONG CAA OF ARCTIC TYPE AIR MASS CONTINUES INTO ERN NEB AND WRN IA OUT OF THE DKTS ON BRISK NW WINDS. TEMPS ALREADY INTO SINGLE DIGITS ABOVE AND BELOW ZERO PTNS SE SD INTO N CNTRL NEB. 04/00Z RUC FCST SFC TEMPS FOR 04/12Z POINT TO LOWS AROUND ZERO NE NEB TO 5 TO 10 ABOVE IN SE NEB AND SW IA AND MAY NOT BE TOO FAR OFF. BASED ON STLT AND MTR TRENDS EXPECT CLS TO DECREASE REST OF NITE IN ERN NEB EXCEPT COUNTIES BORDERING MO RVR VLY. ZONES UPDATED TO LOWER FCST MIN TEMPS AND REFLECT EXPECTED TRENDS IN CLOUDINESS. .OMA...NONE WIESE ne SOUTH CENTRAL NEBRASKA/NORTH CENTRAL KANSAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE HASTINGS NE 1111 AM CST MON JAN 3 2000 PROFILERS AND SATELLITE LOOPS SHOWING THE UPPER LOW ROTATING NEAR THE OKLAHOMA PANHANDLE...ALTHOUGH THE CIRCULATION ON THE SATELLITE IMAGERY DOES NOT APPEAR TO BE WELL DEFINED. DEFORMATION ZONE IS STILL TRYING TO BECOME ESTABLISHED...AND IS MOST LIKELY SETTING UP JUST TO THE SOUTH OF OUR CWA OVER KS. 17Z SURFACE ANALYSIS SHOWED TWO SURFACE LOW CIRCULATIONS...ONE OVER CENTRAL OK WITH THE OTHER OVER SW MO. THE 12Z ETA AND RUC PHASE THESE TWO LOWS TOGETHER OVER SRN MO AND THEN RAPIDLY MOVE THEM INTO IL BY 00Z THIS EVENING. OF ADDITIONAL CONCERN IS THE LACK OF ISENTROPIC LIFT/THERMAL ADVECTION BELOW H6 OVER THE CWFA. THIS IS CONCENTRATED TO THE SOUTH OF THE AREA...NOT SURPRISING GIVEN THE SURFACE LOW POSITION. THUS ANY LIFT WILL BE FROM BROAD UPPER DIVERGENCE AND WEAK DPVA. STILL SNOWING OUT THE WINDOW AND THERE ARE A FEW POCKETS OF SNOW ON THE 88D WHICH ARE EXPANDING IN SIZE. RECENT CALLS TO COUNTIES CONFIRMS AREAS OF LIGHT TO MODERATE SNOW FALLING ON TOP OF VERY SLICK ROADS AND STILL MANY ACCIDENTS. WITH THE FREEZING DRIZZLE ALREADY ON THE ROADS FROM THIS MORNING...ANY NEW SNOW WILL CONTINUE TO CREATE TRAVEL PROBLEMS THUS HAVE OPTED TO CONTINUE EXISTING WINTER WEATHER ADVISORY INTO THE AFTERNOON. WINDS ALSO PICKING UP AS PLANNED...WITH MODELS SHOWING 850 WINDS UP TO 45 KNOTS BY 00Z. .GID...WINTER WEATHER ADVISORY IN EFFECT THIS AFTERNOON FOR SOUTHERN 2/3 OF CWA. DDN ne FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS 245 PM CST MON JAN 3 2000 FCST CONCERNS...TEMPS/CLOUD TREND TONIGHT...THEN SNOW POTENTIAL TUES NIGHT AND WED. .CURRENT... KMVX 88D SHOWING AREA OF -SN DIMINISHING WITH FLURRIES REMAINING OVER ERN ND AND PARTS OF NW MN. ARCTIC FRONT CONTINUES TO ONLY OOZE EAST WITH SOME TEMP FALL IN ROX-DTL-FFM NOTED IN THE PAST FEW HOURS. STIL IN THE LOWER 20S EAST OF THERE AT PKD. MEANWHILE THE VALLEY AND ERN ND STUCK IN THE SINGLE DIGITS. 50H VORT MAX REMAINS OUT WEST OF BISMARCK AS SHOWN BY NICE SPIN ON SATELLITE IMAGERY...AND WILL HAVE TO WAIT TIL THIS AND ENTIRE 50H TROF MOVES EAST BEFORE ANY SIGNIFICANT CLEARING BEGINS. .SHORT TERM... WILL CONTINUE WITH MENTION OF CLOUDS AND SOME FLURRIES THIS EVENING IN MOST ZONES...FOLLOWED BY GRADUAL CLEARING FROM WEST TO EAST OVERNIGHT. USING 18Z RUC AND AXIS OF 50H TROF...WILL PROG MAIN CLEARING INTO THE DVL ZONE 03-06Z...GFK-FAR ZONES 07-10Z AND BJI-FFM AREA AROUND 12Z. TEMP BUST POTENTIAL BIG TONIGHT AS EXPECT TEMPS TO TUMBLE (PROVIDED IT CLEARS)...SPCLY IN DVL/GFK ZONES DUE TO FRESH SNOW COVER AND ENTRENCHED ARCTIC AIRMASS. -22 AT 85H AT KGGW AT 12Z...AND LOOK FOR THIS AIR TO BE OVER CWFA BY 12Z TUES. BUT WILL NOT GO OVERBOARD AS SFC WINDS WILL REMAIN UP MOST OF THE NIGHT AS SFC RIDGE AT 12Z REMAINS OVR CNTRL ND. WILL GO BLO FWC MOS IN DVL/GFK ZONE AND AOA FWC MOS IN MUCH OF MN DUE TO CLOUDS. .LONGER TERM... BRIEF PD OF SUN EARLY TUESDAY...BEFORE WARM ADVECTION CLOUDS INCREASE FROM WEST TO EAST. TEMPS ONCE AGAIN A BIG HEADACHE...BUT EXPECT ARCTIC AIRMASS TO REMAIN IN PLACE IN MOST ZONES KEEPING HIGHS MOSTLY IN THE SINGLE DIGITS...WITH SOME TEENS WCNTRL MN ZONES. ATTENTION FOCUSES ON NEXT SYSTEM NOW ENTERING THE BC/WASHINGTON COAST. SYSTEM LOOKS IMPRESSIVE AND THINK IT COULD DUMP A FAIR AMOUNT OF SNOW TO PARTS OF THE NRN CWFA. LIKE ETA/AVN AND ITS TRACK WITH THIS SYSTEM...HAVING SFC LOW NR MOT 12Z WED AND THEN TO JUST EAST OF GFK BY 00Z THU. TRACK OF 85H LOW RIGHT ALONG US/CANADA BORDER AND EXPECT BEST SNOWS ALONG THIS BAND. STRONG 85H WARM ADVECTION 06-12Z WED...AND 285K ISENTROPIC SFC SHOWS GOOD LIFT WITH SPEC HUMIDITY INCREASING TO 2.5-3 G/KG IN ERN ND. 85H TEMPS INCREASE TO 0C SRN ZONES BY 12Z WED ON ETA WITH AVN BLO OC. LOW MOVES TO NR DLH BY 00Z THU BUT WRAPAROUND SNOWS SHOULD CONTINUE WEST INTO CWFA ALONG INVERTED TROF. WILL HAVE SNOW DEVELOP IN WAA PATTERN TUES NIGHT AND THEN CONTINUE WED...WITH HIGHEST POPS NRN ZONES. TRACK OF SFC/85H LOW INDICATING BEST SNOWS ALONG AND NORTH OF A DVL-GFK-BJI LINE. CONDESATION PRESSURE DEFICITS AND RH ALSO PINPOINT NRN ZONES FOR BEST CHC OF SNOW. NO HEADLINES OR AMOUNTS NEEDED ATTM SINCE IT IS IN THE 3RD AND 4TH PD. POTENTIAL FOR FZRA WAS BROUGHT UP BY WFO ABR IN COORD CALL...BUT ATTM WILL NOT MENTION IN FAR SRN ZONES AS FCST SOUNDINGS FOR SE ND CORNER AT 12Z WED INDICATE COLUMN AOB 0C. EXTENDED...LONG RANGE MODELS SIMILAR IN KEEP CWFA UNDER ACTIVE PATTERN THROUGH THE EXTENDED FORECAST PERIOD. INITIALLY...MRF AND UKMET ARE PRETTY SIMILAR WITH ECMWF SLOWEST OF THE THREE. MRF AND UKMET MOVE SFC LOW INTO LK SUPERIOR WITH INVERTED TROF BACK INTO N PART OF CWFA BY 12Z THU...SO WILL KEEP IN CHC OF SNW AS ALREADY ADVERTISED FOR THU. THEN...BY 12Z FRI...MODELS COME INTO BETTER AGREEMENT WITH SFC RIDGE BUILDING IN OVER CWFA AS NEXT SYSTEM ORGANIZES IN CANADIAN ROCKIES. UKMET AND ECMWF THEN BECOME MORE CONSISTENT THROUGH THE LATTER PARTS OF THE EXTENDED...WITH MRF DEVELOPING A SFC LOW FASTER AND LOCATING IT FARTHER S...WHILE UKMET AND ECMWF KEEP SFC LOW IN N SK. WITH MRF DEVELOPING SFC LOW MUCH FARTHER S THAN OTHER TWO MODELS...WILL DISREGARD PLACEMENT AT THIS TIME...AND KEEP CONTINUITY WITH PRIOR FORECAST OF NO PCPN FOR FRI TO SUN TIME PERIODS. HOWEVER...LOW DOES APPROACH FOR MON...SO WILL PUT CHC OF SNW IN MON FORECAST. AS FAR AS TEMPS...WITH NEW SNOWCOVER AND ADDITIONAL ACCUMS POSSIBLE BEFORE EXTENDED PERIOD...WILL KEEP CONTINUITY WITH PRIOR FORECAST AND CUT BACK SIGNIFICANTLY ON MRF GUIDANCE NUMBERS. HOWEVER...STILL EXPECT TEMPS TO BE IN NORMAL TO SLIGHTLY ABOVE NORMAL RANGE. .FGF...NONE. RIDDLE/NG nd FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS 1020 AM CST MON JAN 3 2000 FCST CHALLENGE...TEMPS AND -SN THIS AFTN. ARCTIC FRONT HAS PUSHED THROUGH ALL OF ERN ND INTO SD...BUT STILL HAVING A HARD TIMING PUSHING EAST INTO THE HIGHER ELEVATIONS OF NW MN EAST OF THE VALLEY. TEMPS REMAIN IN THE MID TEENS TO LOWER 20S ROX-TVF-DTL-FFM EAST WHILE WEST THERE ARE IN THE SINGLE DIGITS. KMVX 88D SHOWING WIDESPREAD LIGHT SNOW OVER MUCH OF CWFA...EXCEPT FOR NW AND SE CORNERS. 88D RELFECTIVITIES SHOWING HEAVIEST SNOW (1-2 SM) NR A FAR-CKN-TVF LINE. OVERALL EXPECT UP TO AN INCH MAX IN SNOW AREA BY THE TIME IT ENDS. WHEN WILL IT END? WATER VAPOR AND 12Z ANALYSIS SHOWS 50H TROF STILL OVER WRN ND AND 12Z RUC AND LATEST ETA/NGM ALL IN GOOD AGREEMENT IN ONLY SLOWLY MOVING THIS EAST INTO THE VALLEY BY 00Z. ALSO SFC MAP SHOWS WK SFC TROF INTO CNTRL ND. THUS WILL KEEP FLURRIES DVL ZONE AND MENTION LIGHT SNOW OVER THE REST OF ERN ND AND WRN MN BEHIND ARCTIC FRONT THE REST OF THE DAY. SOME CLEARING OVER CNTRL ND MOVING INTO NW ZONES...BUT IT WILL BE PATCHY AND CLOUDS SHOULD PREVAIL. AS COLD AIR OOZES EAST INTO MN TEMPS WILL FALL IN THE DTL-FFM-TVF-BJI ZONES. OTHERWISE THEY WILL HOLD STEADY. UPDATE OUT BY 11 AM. .FGF...NONE. RIDDLE nd AREA FORECAST DISCUSSION ..UPDATED.. NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 855 PM CST MON JAN 3 2000 COMBO OF 00Z UPPER AIR...88D AND IR SATL TRENDS REVEALS WX SYSTEM HAVING A HARD TIME PUTTING IT ALL TOGETHER. WITH SFC LOW NORTH OF IND AT 02Z...88D RETURNS DIMIMISHING OVR WRN PTNS OF CWA AND COLD CLD IR SATL EHNCMNT AT NEARLY A STEADY STATE...FEEL JUSTIFIED TO CANCEL WINTER STORM WARNING FOR WRN CWA...AND DOWNGRADE WARNING TO WINTER WX ADVSRY OVR ERN PTNS OF CWA. STG SFC WINDS HAVE NOT MATERIALIZED AND ARE NOT EXPECTED TOO AS H8 LOW PASSES OVR SE CORNER OF STATE...WITH H7 LOW MOVING OVER CENTRL WISC. FEEL SNOW AMTS OF 2- 5 INCHES SHOULD BE ABOUT RIGHT IN ADVSRY AREA AS LATEST RUC PROG STILL TRIES TO GENERATE A BRIEF SNOWBURST WITH STRECHED OUT H5 VORT AFTER 06Z. .MKX...WINTER WEATHER ADVISORY TNT...WIZ051-052-058>060-064>066- 069>072. TZ wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 258 PM CST MON JAN 3 2000 FCST FOCUS ON SYSTEM MOVG UP FM SRN MO FOR TONIGHT AND EARLY TUESDAY. SEEDER-FEEDER MECHANISM SHOWING UP WELL ON KMKX 88-D. -DZ FALLING AT OFFICE ATTM..WITH HIGHER LVL RETURNS MOVG IN FM SW. MSN REPORTED -DZ WITH 30F...THEN WENT TO -SN AS HIER SEEDER CLDS MOVED OVR SITE. DBQ REPORTED FZRA FM 1717Z TO 1929Z THEN WENT TO SNOW. VAD WIND PROFILE SHOWS RETURNS LOWERING FM 10K FT AS ICE CRYSTALS FALL FROM BASE OF MID DECK. THIS WL MOISTEN DRY LAYER BETWEEN 7 AND 10K FT THAT RUC BUFKIT SNDGS WERE DEPICTING ...AND ALLOW CRYSTALS TO GROW WITH MOISTURE IN THE LOWER LVLS. TEMPS UNDER 32F IN WRN CWA MEANS POSSIBLE FZDZ BEFORE GOING OVR TO ALL SNOW...BUT WILL NOT LAST LONG AS MID DECK SHUD COVER ALL OF CWA BY 5 PM. 18Z RUC VERIFYING 12Z MDL RUNS...TAKING SFC LO IN SRN MO OVR NRN IN. INTO SRN LWR MI BY 12Z. BANDS OF PCPN FILLING IN FM SW WI TO ERN KS BEGINNING TO DEFINE SNOW AREA THAT WILL CROSS SRN WI OVRNGT. 18Z RUC H7 UVV FIELDS SIMILAR TO 12Z ETA. WETZEL FCST INGREDIENTS MACROS ON AWIPS SHOW Q VECTOR CONVERGENCE SUSTAINED OVER ERN 2/3 OF CWA THRU 06Z AND LINGERING IN THE EAST TIL 12Z. SPEC HUMIDITIES ARE IN THE 3- 4G/KG RANGE. H8 TEMPS HANG IN THE 0C RANGE OVER RACINE AND KENOSHA CNTYS...SO SNOW AMOUNTS MAY BE LIMITED BY MIX WITH RAIN. WL UP SNOW ACCUMULATIONS SLGTLY FOR IOWA...SAUK AND MQT CNTYS. CURRENT BAND COULD LAY DOWN A FAST 1 TO 2 INCHES BEFORE 00Z...SO WL EXPAND THE RANGE SLGTLY. OTHERWISE...CURRENT WARNING AND ADVISORIES AND EXPECTED SNOW AMOUNTS WL REMAIN IN PLACE. LONGER TERM...RDG BUILDS IN QUICKLY WITH COOLER TEMPS TUE NGT...BUT NEXT SYSTEM RACES SEWD INTO NRN PLAINS BY WED MORN. WAA AHD OF SYSTEM WL BRING CLDS BACK IN AND NUDGE TEMPS UP FOR WED BEFORE PCPN BEGINS WED NGT INTO THU. GUIDNC TEMPS REASONABLE. THANKS TO DVN...LOT...ARX AND GRB FOR COORDINATION TDY. .UWNMS...NOT AVBL. .MKX...WINTER STORM WARNING TNT...WIZ047-051-052-057>059-060-063>066- WINTER WEATHER ADVISORY TNT...WIZ046-056-062-071-072. /...0.../.../ REM wi SOUTH CENTRAL AND SOUTHEAST COLORADO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO 246 AM MST TUE JAN 4 2000 GENERAL CHALLENGE WILL BE THE TIMING OF FAST...ALBEIT WEAK...MOVING MID-LEVEL SHORTWAVE TROUGHS THROUGH THE WESTERLIES FOR THE NEXT 2-3 DAYS. SOMEWHAT OF A WEAK NW FLOW CHINOOK WIND PATTERN FOR TDA AND BORA WIND PATTERN LATE TNGT/WED. TDA: MORNING SHOULD START OFF QUITE COLD WITH ABOVE AND BELOW SINGLE DIGITS AROUND SUNRISE...EXCEPT FOR FAVORED DRAINAGE MIXING AREAS IE NEAR MOUNTAINS. CURRENT SATELLITE IMAGERY ANIMATIONS SHOWED NEXT MID-LEVEL SHORTWAVE TROUGH ABOUT TO ENTER THE PACIFIC NORTHWEST. FAIRLY CLOUD-FREE ACROSS CO...EXCEPT FOR SOME HIGH MOUNTAIN VALLEY ST/FG IN NORTHWEST QUAD. GOOD SHORT RANGE MODEL CONTINUITY ON BRINGING FLAT SHORTWAVE RIDGING. MODELS STILL CONSISTENT ON WARMING 700MB TEMPS TO -4 DEG C TO -8 DEG C THIS AFTERNOON WITH WINDS 270-290 AT 25-35KTS. LATEST RUC CONFIRMS THESE 700MB TEMPS. SURFACE LEE TROUGHING SHOULD FORM ACROSS THE PLAINS LATER ON THIS AFTERNOON. SOME CONCERN WITH NW FLOW CHINOOK WIND PATTERN...MAINLY ALONG AND WEST OF I-25 IN PUB/COS AREAS. RUC/ETA HAVE PRETTY GOOD MOUNTAIN TOP STABLE LAYER WITH LESS STABLE ABOVE. SOME FORWARD SPEED SHEAR THIS MORNING...BUT WIND FLOW MAY BE TOO NORTHWESTERLY. FLOW BECOME MORE ORTHOGONAL TO BARRIER BY THIS AFTERNOON WHILE MAINTAINING MOUNTAIN TOP STABLE LAYER...BUT WINDS DECREASE SLIGHTLY. STRONGEST WINDS MAY BE FURTHER NORTH OF CWFA. COORD WITH DEN AND WILL NOT ISSUE ANY WIND HEADLINES AT THE MOMENT. CURRENT ZONES HAVE WINDS IN FOR MOUNTAINS AND WILL ADD WEST 15-25 MPH GENERALLY ALONG AND WEST OF I- 25 FOR THIS AFTERNOON IN PUB/COS AREAS AND A LITTLE STRONGER IN CENTRAL MOUNTAINS. OTHERWISE...MORNING SHOULD START OUT FAIRLY SUNNY WITH MID-HIGH CLOUDS MOVING INTO WESTERN CO BY THIS AFTERNOON. AS STATED BY PREVIOUS FORECASTER...OVERALL DEEP MOISTURE IS FAIRLY MEAGER THIS AFTERNOON. WILL MAINTAIN SLIGHT CHANCE WORDING FOR 58/59 FOR OROGRAPHICS ALONE. MOS HAS BEEN PRETTY CONSISTENT WITH TUE'S MAX TEMPS AND SEE NO REASON TO STRAY FROM MOS AND CURRENT ZFP. TNGT/WED: SENSIBLE WEATHER CONTINUES TO CONCENTRATE ON POTENTIAL WINDY CONDITIONS. A SERIES OF WEAK MID-LEVEL SHORTWAVE TROUGHS WILL CONTINUE TO INVADE THE NORTHERN ROCKIES TNGT THEN MOVE INTO THE PLAINS ON WED AFTERNOON. ONLY A WEAK CYCLONIC SHEAR AXIS EXPECTED TO PASS THROUGH CWFA ON WED. POTENTIAL WINDY CONDITIONS TURNS TOWARDS A BORA WIND PATTERN. HOWEVER THINGS AREN'T QUITE JUXTAPOSED ACROSS CWFA PER LATEST MODELS. 06Z/05 WED ETA CROSS SECTION FROM GJT-COS-CO/KS BORDER REVEALED RATHER HEALTHY MOUNTAIN TOP STABLE LAYER WITH LOWER STABILITIES ABOVE. 700-500MB WIND FLOW UNIDIRECTIONAL AROUND 270-290 DEGS AT 30- 40KTS. BY WED MORNING MOUNTAIN TOP STABLE LAYER LIFTS AS WINDS DECREASE. CURRENT ZFP HAS WINDY GOING WHICH LOOKS GOOD. WILL ADD SOME WIND IN FOR LATE TNGT. AGAIN WILL HOLD OFF ON ANY WIND HEADLINES. MIN TEMPS WILL SOLELY DEPEND ON SURFACE WINDS PICKING UP AND MOUNTAIN WAVE CLOUD...IF AT ALL. TUE EVE SHOULD SEE SOME RADIATIONAL COOLING...SO WILL MAINTAIN CURRENT ZFP. WILL CONTINUE SLIGHT CHANCE/CHANCE SNOW SHOWERS FOR 58/59/60/61 FOR OROGRAPHICS... BUT GREATEST QUALITY OF DEEP MOISTURE SHOULD REMAIN OVER WESTERN CO. MID-LEVEL LAPSE RATES NOT ALL THAT GREAT. SNOW MODEL KICKED OUT MAYBE AN INCH FOR SAWATCH RANGE. ON WED...COLD FRONT WILL PASS THROUGH...BUT MAY ONLY TAKE A FEW DEGS OFF MAX TEMP GIVEN POTENTIAL MIXING...NORTHWESTERLY DOWNSLOPE COMPONENT AND SUNSHINE. DEEPER COLD AIRMASS DOESN'T ARRIVE UNTIL LATE WED. CURRENT ZFP LOOKS GOOD...SO WILL CONTINUE. EXTENDED(THU-SAT): 60-72HR AVN SHOWING ANOTHER WEAK MID-LEVEL SHORTWAVE TROUGH MOVING THROUGH CO THU AM WITH A MORE HEALTHIER SYSTEM PULLING INTO THE NORTHERN PLAINS. FAIRLY DEEP WEST- NORTHWESTERLY FLOW EXPECTED WITH THIS PASSAGE. QUALITY OF MOISTURE IS POOR AT BEST. MAY GET ONE OR TWO -SHSN IN MOUNTAINS...BUT THAT IS IT. RARELY DON'T LIKE TO TOUCH THE EFP...BUT PLAN TO PULL CHANCE OF SNOW FOR PLAINS AND SAN LUIS VALLEY FOR THU. PROGGED PATTERN DOESN'T SUGGEST IT. WILL CONTINUE MENTION IN MOUNTAINS...BUT WILL MAKE IT SNOW SHOWERS. LATEST MRF/NOGAPS CONTINUE TO SUGGEST OVERALL UPPER FLOW PATTERN TO REMAIN WESTERLY ACROSS U.S. FRI/SAT WHICH DOESN'T SPELL MUCH FOR SIGNIFICANT WEATHER. EXCEPT FOR SOME OROGRAPHICALLY DRIVEN -SHSN AND WINDY CONDITIONS IN SOUTHWEST/CENTRAL MOUNTAINS. REMAINDER OF EFP LOOKS GOOD AND WILL NOT CHANGE. .PUB...NONE. METZE co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 216 AM CST TUE JAN 4 2000 A BROAD TROUGH AT 500MB WITH SEVERAL EMBEDDED SHORTWAVES IS PROGRESSING QUICKLY ACROSS THE CENTRAL US. 7Z SURFACE ANALYSIS PLACES THE LOW IN SOUTHERN MI WITH STRONG NORTHWEST FLOW AND COLD AIR ADVECTION OVER THE UPPER MIDWEST. TEMPS ARE CURRENTLY WELL BELOW ZERO ACROSS ND. A SECONDARY SHORTWAVE APPARENT IN THE 6Z RUC TROP ANALYSIS OVER SOUTH CENTRAL SD IS SUPPORTING AN AREA OF FLURRIES FROM FGF TO OAX. MAIN FORECAST CONCERNS ARE DEALING WITH THE RESIDUAL EFFECTS OF THE STORM TODAY...THE MAGNITUDE OF COLD AIR TONIGHT...AND THE NEXT SYSTEM SLATED FOR LATE WEDNESDAY. MODELS ARE IN GENERAL AGREEMENT IN THE SHORT TERM ALTHOUGH THE AVN'S HANDLING OF THE SHORTWAVES DIFFERS FROM THE NGM/ETA AND THE ETA BRINGS PRECIP FARTHER SOUTH INTO IOWA THAN THE NGM/AVN ON WEDNESDAY. ALTHOUGH CLOUDS AND FLURRIES WILL PERSIST THROUGH THE DAY...THE SCREAMING MESSAGE WILL BE COLDER TEMPS AND WIND. A SURFACE AND UPPER LEVEL RIDGE DEVELOPS OVER THE REGION TUESDAY NIGHT INTO WEDNESDAY INSURING MAXIMUM RADIATIONAL COOLING ON TOP OF THE SNOW COVER IN PLACE. THIS PATTERN RAPIDLY TRANSITIONS AS A SHORTWAVE MOVES THROUGH THE REGION IN NORTHWEST FLOW LATE WEDNESDAY INTO THURSDAY. GULF MOISTURE WILL BE CUTOFF AND THE NGM/AVN KEEP MOST OF THE PRECIP IN THE NORTH HALF OF THE CWA. GIVEN THE PROGGED TRACK OF THE SURFACE CYCLONE AND 500MB VORT MAX...I DON'T THINK WE'LL SEE MUCH OF ANYTHING IN OUR CWA. LOW POPS LOOK OK. REST OF EXTENDED LOOKS GOOD TOO. .DVN... IA...NONE. IL...NONE. MO...NONE. WOLF il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DODGE CITY KS 250 AM CST TUE JAN 4 2000 ...MAIN CHALLENGE THIS CYCLE WILL BE TEMPERATURES... 00Z ANALYSIS HAD AXIS OF UPPER LEVEL TROF OVER WEST KS WITH 170 METER H5 HEIGHT RISES OVER SLC AND 130KT JET STREAK STILL DIVING DOWN WEST SIDE OF H3 TROF OVER EASTERN MONTANA. IN LOWER LEVELS H8 ANALYSIS HAD ARCTIC FRONT FROM LBB TO OKC AND SGF WITH 150 METER HEIGHT RISES AT AMA. THE MAIN H8 ARCTIC COLD POOL WAS STILL IN SOUTHERN CANADA NEAR WINNIPEG. AT THE SURFACE THE CORE OF AN ARCTIC HIGH WAS OVER WESTERN NE AND STILL OOZING SOUTH WITH BELOW ZERO TEMPERATURES AT SEVERAL LOCATIONS IN SOUTHWEST SD AND NORTHWEST NE. SATELLITE IMAGERY SHOWS THE WEST EDGE OF THE CLOUDS NOW JUST EAST OF MY ZONES WITH MAINLY CLEAR SKIES ACROSS THE SNOW COVERED GROUNDS OF WESTERN KANSAS. AN UPSTREAM SYSTEM JUST MOVING ONTO THE BC COAST IN WESTERN CANADA WAS PRODUCING ONLY MODEST HEIGHT FALLS ALONG THE COAST AT 00Z AND DOES NOT APPEAR TO BE NEARLY AS STRONG AS THE LAST SYSTEM WITH ONLY 90 TO 100KTS IN THE H3 JET CORE DRIVING IT. AT 06Z SURFACE ANALYSIS SHOWS ALL MODELS STRUGGLING WITH BOUNDARY LAYER COLD AIR. RUC WAS DOING BEST WITH IT WHILE ALL OTHERS WERE EASILY 10 DEG F TOO WARM ALREADY. IN LATER PERIODS ALL MODELS ARE IN A BIG RUSH TO SCOUR OUT THE COLD AIR. PROFILERS AND SOUNDINGS CURRENTLY SHOW THE TOP OF THE COLD DOME AT NEARLY 16K FEET SO IT IS UNLIKELY ANY OF THE MODELS WILL BE REASONABLE WITH THEIR BOUNDARY LAYER TEMPERATURE FORECASTS. THE OTHER MAJOR FACTOR FOR TODAY WILL BE THE EXTENT OF THE SNOW PACK. A FEW OF MY EAST CENTRAL ZONES REAPED THE BENEFITS OF STRONG MID LEVEL MESOSCALE CONVERGENCE ALONG THE DEFORMATION ZONE YESTERDAY AND WERE REPORTING IN WITH SNOW ACCUMULATIONS OF A FOOT OR BETTER...MUCH TO THE CHAGRIN OF THIS FORECASTER. THE EXTENT OF THE SNOW PACK WILL BE BETTER KNOWN BY SUNRISE IN THE VISIBLE IMAGERY BUT MEANWHILE WILL HAVE TO UNDERCUT MOS FOR MOST OF MY ZONES. GOING FORECAST LOOKS EXTREMELY AMBITIOUS FOR WARMING TODAY AND WILL HAVE TO ADJUST DOWNWARD. THE SAME IS TRUE FOR TONIGHT AND WEDNESDAY IN SPITE OF THE EFFECTS OF THE UPSTREAM SYSTEM NOW MOVING ONSHORE IN THE PACIFIC NORTHWEST. WITH LITTLE OR NO MOISTURE AVAILABLE A SUNNY DAY SHOULD ENSUE. THE LEE SURFACE TROF THAT THE MODELS DEVELOP BY LATE AFTERNOON WILL LIKELY BE MAINLY ALOFT ABOVE THE COLD BOUNDARY LAYER SO WILL NOT BRING THE WINDS BACK TO SOUTHERLY UNTIL MUCH LATER THAN THE MOS DOES. MODELS THEN PROGRESS THIS SURFACE TROF EASTWARD THROUGH MY ZONES BY WEDNESDAY EVENING. THE ETA IS FARTHEST SOUTH WITH THE SURFACE LOW BUT IT TOO CONTINUES TO STRUGGLE WITH THE BOUNDARY LAYER COLD POOL THUS BELIEVE THE SURFACE LOW ETA HAS FORECAST TO BE OVER GAG BY 18Z WEDNESDAY WILL MORE LIKELY BE SOMEWHERE WEST OF AMA AND SINKING SOUTH WITH TIME ALONG THE EDGE OF THE COLDER AIR. CERTAINLY SOME HIGHER LEVEL CLOUD WILL SPILL OVER THE MOUNTAINS BY LATE WEDNESDAY NIGHT AS THE UPSTREAM SYSTEM APPROACHES WITH MOUNTAIN ENHANCEMENT HELPING OUT. THIS WILL ALSO TEMPER HIGHS FOR WEDNESDAY IN SPITE OF THE PASSAGE OF THE WAVE ALOFT BY EVENING. EXTENDED DISCUSSION... ANOTHER COLD PUSH APPEARS REASONABLE FOR WEDNESDAY INTO THURSDAY. ALSO LATEST GUIDANCE SUGGESTS THAT PARTS OF THE CWA COULD SEE LOWS BELOW 20F...SO FORECAST WILL BE UPDATED TO REFLECT THIS. ALSO...LATEST AVN 850 TEMPS FOR 0Z/FRIDAY INDICATE THAT THE WEST MAY VERY WELL EXPERIENCE HIGHS GREATER THAN 40F. AS A RESULT...WILL PROVIDE THE CWA WITH A WIDER TEMP RANGE FOR THURSDAY HIGHS. REST OF EXTENDED WILL REMAIN UNCHANGED. PRELIMINARY GUIDANCE FOR COORDINATION ONLY. OFFICIAL FORECASTS ARE CONTAINED WITHIN THE DODGE CITY ZONE FORECAST. DDC 033/016 042/018 042 000 GCK 036/015 047/015 043 000 EHA 038/019 048/019 045 000 LBL 038/020 047/018 044 000 HYS 036/018 044/018 042 000 P28 034/022 048/022 045 000 .DDC...NONE. JOHNSON/MCCAMMON ks DEEP SOUTH TEXAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE BROWNSVILLE TX 905 PM CST MON JAN 3 2000 STILL GETTING SOME HIGH LEVEL MOISTURE STREAMING ACROSS SOUTH TEXAS THIS EVENING AS SUBTROPICAL JET ADVECTS MOISTURE NORTHEASTWARD FROM THE PACIFIC. THE LATEST RUC SHOWS THE STRONG UPPER TROF OVER NORTH TEXAS WILL CONTINUE TO MOVE EAST DURING THE NIGHT. THE COLDEST TEMPS AND STRONGEST WINDS ARE PUSHING INTO CENTRAL TEXAS THIS EVENING AND SHOULD MAKE IT INTO SOUTH TEXAS BY THE EARLY MORNING HOURS. ETA CROSS SECTIONS SHOW LOW LEVEL WINDS IN THE 30 TO 40 KNOT RANGE BY 12Z. FOR THIS REASON...WILL RAISE A SCA FOR THE BAY TONIGHT. SEAS HAVE DIMINISHED BELOW CRITERIA OFFSHORE BUT WILL KEEP SCA UP IN ANTICIPATION OF THE STRONGER WINDS OVERNIGHT AND TOMORROW MORNING. THE LATEST ETA SHOWS SFC HIGH PRESSURE SETTLING IN OVER SOUTH AND CENTRAL TEXAS BY WEDNESDAY MORNING. WE ALREADY HAVE FROST MENTIONED IN THE FORECAST FOR WESTERN SECTIONS BUT THIS LATEST ETA SHOWS SFC TEMPS NEAR 30 OVER THE NORTHERN AND WESTERN ZONES. WILL UPDATE THE ZONES TO LOWER TEMPS A BIT OUT WEST TONIGHT AND TUESDAY NIGHT. WILL MENTION THE POSSIBILITY OF SOME FREEZING TEMPS FOR THE WESTERN ZONES WED MORNING. .BRO...SCA GMZ130-150-155-170-175. 63 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 1046 AM EST TUE JAN 4 2000 CURRENT FCST ON TRACK AND WL NOT UPDATE THIS MORNING. RADAR SHOWS SNOW SHOWERS DEVELOPING ACRS CWA AND VISIBILITIES BEGINNING TO DROP HERE AND TO OUR WEST. LATEST RUC AND ETA SUPPORT SNOWFALL AMOUNTS OF AN INCH OR LESS AWAY FM LAKE WITH DEEP MOISTURE LACKING AND QPF AMOUNTS VERY SMALL. MAIN UPPER TROF AND VORT AXIS TO SWING INTO WRN FA THIS AFTN AND ACRS REMAINDER OF FA THIS EVENING. VISIBLE SAT PICS SHOW SOME HIGHER TOPS AHEAD OF THIS FEATURE IN ERN IA/WRN IL. SFC OBS REFLECT THIS WITH LOWER VISIBILITIES SAME AREAS. MAY HAVE TO ADD SNOW SHOWERS INTO EVENING ZONES BUT WL WAIT FOR FULL AFTN EVALUATION. SATELLITE VIS PICS ALSO SHOW SOME HIGHER TOPS COMING ACRS LM. NEW ETA STARTS INVERSION OFF MUCH HIGHER THAN PREVIOUS RUNS AND IT CLIMBS TO 6KFT BY 00Z. H8 AND SFC ANALYSIS INDICATES FAVORABLE FETCH DOWN LAKE WITH CYCLONIC FLOW. ETA SEEMED TO INITIALIZE H8 TEMPS WELL AND SMALL LIMITING FACTOR FOR LES IS DELTA T VALUES REMAINING IN MIDDLE TO UPPER TEENS. STILL LIKE CURRENT ACCUMS NEAR THE LAKE... COULD EVEN SEE A LITTLE MORE BY LATE AFTN THAN CURRENT INCH. WL NOT UPDATE UNTIL MORE SIGNIFICANT BANDS SET UP. TEMPS ALSO LOOKING GD WITH UPSTREAM TEMPS IN MIDDLE TO UPPER 20S. .IWX...NONE. LASHLEY in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1040 AM EST TUE JAN 4 2000 ...EVOLUTION OF LES/BLSN ARE MAIN UPDATE ISSUES... UPR MI HAS TRANSITIONED INTO LES REGIME AS 988MB SFC LO OVR SE ONTARIO LIFTS INTO QUEBEC. LL CAA/DAA UNDERWAY ACROSS CWA PER UPSTREAM TEMPS/DEWPTS BELOW 0F IN W ONTARIO. RUC/MESOETA AGREE THAT CONTINUED CAA WILL MAINTAIN AMPLE THERMAL INSTABILITY FOR LES WITH LK SFC-850MB DELTA/T'S INCREASING TO 18C...HOWEVER RUC PROG SOUNDINGS DEPICT INVERSION HEIGHT REMAINING BLO 850MB. QUITE STABLE CYPL 12Z RAOB ALSO FAVORS LIMITED MIXED LAYER DEPTH MINIMIZING SHSN INTENSITY AND ACCUMS. CURRENT MAX 88D RELFECTIVITIES OF 20DBZ SUPPORT ONLY LIGHT ADDITIONAL ACCUMS WITH MEAN MIXED LAYER NNW FLOW CONTINUING TO FAVOR MQT-ALGER-LUCE COUNTIES...AND MORE LIMITED FETCH FOR KEEWENAW AND W SUPERIOR BORDER COUNTIES. GUSTY WINDS WILL REMAIN MAIN PLAYER THRU AFT AND WARRANT CONTINUATION OF SNOW/BLSN ADVISORIES FOR E LK SUPERIOR BORDER COUNTIES PER RUC TIME/HEIGHT CROSS SECTIONS SHOWING 30KT PK WIND IN MIXED LAYER. MODELS/GUIDANCE DEPICT WINDS SLACKENING AFT SUNSET ENDING BLSN. .MQT...SNOW AND BLOWING SNOW ADVISORY THIS AFT MQT CO. ...SNOW AND BLOWING SNOW ADVISORY INTO EARLY TONIGHT ALGER-LUCE-SCHOOLCRAFT COUNTIES. GALE WARNING EAST HALF LAKE SUPERIOR THIS AFTERNOON. WOLF mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BUFFALO NY 958 AM EST TUE JAN 4 2000 WE JUST ISSUED A HIGH WIND WARNING FOR PART OF THE WESTERN FINGER LAKES REGION...AS A NARROW LINE OF SHOWERS ACCOMPANIED BY VERY STRONG WINDS HAS DEVELOPED DURING THE PAST HOUR. THERE HAVE BEEN SOME REPORTS OF TREES DOWNED AS THIS AREA PASSED WESTERN COUNTIES. THE WARNING WILL EXPIRE AT 11:30 AM. A WIND ADVISORY FOR THE ENTIRE REGION WILL CONTINUE THIS AFTERNOON WITH GUSTS OVER 40 MPH COMMON. THE WINDS WILL SUBSIDE THIS EVENING AFTER FRONTAL PASSAGE. THE 12Z RUC PROFILES SHOW THE FRONTAL PASSAGE WELL...AND TEMPERATURES DROPPING THROUGH THE 40S ACROSS THE REGION...WITH 30S IN THE WEST BY LATE AFTERNOON. THE PRECIP WILL END FROM WEST TO EAST DURING THE AFTERNOON...WITH A SHARP BACK EDGE TO THE RAIN EVIDENT ON THE 88D. I DECIDED TO DROP SNOW ACCUMULATIONS FOR LATE THIS AFTERNOON...SINCE MUCH OF THE PRECIP AFTER IT GETS COLD ENOUGH WILL BE SCATTERED. IN ADDITION...THE GROUND IS STILL QUITE WARM. REST OF FCST UNCHANGED...EXCEPT FOR SOME WORDING CHANGES. .BUF...HIGH WIND WARNING THROUGH 11:30 AM FOR NYZ003-004-013-014 WIND ADVISORY FOR TODAY AND EVENING NYZ001>008-010>014-019>021 PO/TP ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MORRISTOWN TN 959 AM EST TUE JAN 4 2000 SURFACE LOW EXITING GREAT LAKES TO THE NORTHEAST. MAIN FRONTAL ZONE EXITING CWA THIS MORNING. WIND ADVISORY WILL EXPIRE AS WINDS SHIFT TO WEST AND PRESSURE GRADIENT MOMENTARIALLY SLACKENS. RAOBS AND RUC/MESOETA DEPICT SPEEDS SOMEWHAT LOWER THAN PREVIOUS RUNS REFLECTING SURFACE LOWS CURRENT TREND. POST-FRONTAL TROUGH AND CAA MOVES QUICKLY IN THIS AFTERNOON. FOR UPDATE...WILL DROP POPS AND WND ADVSRY. WILL INTRODUCE SOME SUN AND COOL TEMPS A BIT IN THE NORTHEAST. SON tn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BURLINGTON VT 1009 AM EST TUE JAN 4 2000 WL DROP WARNINGS WITH MORNING UPDATE. WFNT FM ST LAW CNTY ACRS ADRNDCKS THEN SNAKING SWD...W OF S VT. TMPS HAV WRMD INTO 50S AS FAR N AS PTD...BUT STILL HANGING NR 32 AT MSS. ALSO NR 32 IN CT VLY. WFNT WL SLOWLY LIFT N AND E TAFTN RCHG W VT BUT MAY HAV TROUBLE GETTING E OF GREEN MTNS WHERE TMPS WL STRUGGLE TO EXCEED 40. ELSW FM CHMPLN VLY WWD TMPS WL LKLY RISE INTO 50S...XCP COOLER MSS. GOOD SLUG OF RA MOVG NE ACRS E NY/VT WITH MORE RA TO THE W ASSCD WITH CDFNT SO WL CONT PDS OF RA TAFTN. WITH TMPS NR FRZG AT MSS/CT VLY WL ALSO KEEP POCKETS OF FZRA INTO ERLY AFTN FOR THESE AREAS. CDFNT ON A YTR-ROC LN AT 15Z AND RUC/MSO INDCTG FROPA 18-21Z ACRS NNY SO HAV INDCTD FALLING TMPS W ZNS FOR LTR IN THE DAY. ALSO...SOME GUSTY WINDS XPCTD W ZNS AFT FROPA AND WSHFT TO WSW. NO CHGS BYND 1ST PD. .BTV...NONE. KJC vt EASTERN WASHINGTON AND NORTH IDAHO AREA FORECAST DISCUSSION...CORRECTED NATIONAL WEATHER SERVICE SPOKANE WASHINGTON 230 AM PST TUE JAN 4 2000 CORRECTED WINTER WEATHER HIGHLIGHTS TO ADD WA ZONE 37 IMPRESSIVE LOOKING FRONTAL SYSTEM ON SATELLITE LOOPS CONTINUES TO OCCLUDE OVER WEST CENTRAL BC THIS MORNING...WHILE UPPER LEVEL TROF CONTINUES TO DEEPEN ALONG 130W. THE LOW CENTER HAS DEEPENED MORE THAN THE 00Z MODELS WOULD INDICATE PER SURFACE OBS. LATEST RUC HAS THIS NOTION IN MIND. THE MAIN CONSEQUENCE OF THE DEEPER SURFACE LOW IS A STRONGER WIND FIELD...WHICH SUBSEQUENTLY RESULTS IN STRONGER WARM AIR ADVECTION. THIS WAA HAS BEEN STEADILY WARMED TEMPS ACROSS MOST OF EAST WASHINGTON THIS MORNING WITH SNOW LEVELS RISING ABOVE THE LOWER ELEVATIONS ACROSS MUCH OF THE COLUMBIA BASIN AND INTO THE SPOKANE AREA. THE MOUNTAIN VALLEYS ACROSS THE NORTHERN MOUNTAINS AND IDAHO PANHANDLE ARE A LITTLE MORE PROTECTED FROM THIS WAA AND SHOULD CONTINUE TO SEE SNOW. SIGNIFICANT PRECIPITATION WILL CONTINUE UNTIL FRONT PASSES THROUGH THE AREA LATER THIS MORNING. TIMING OF THE FRONT PER SATELLITE LOOKS FAIRLY CONSISTENT WITH THE MODELS...SUGGESTING FROPA OVER THE CASCADES AROUND 13Z AND INTO THE SPOKANE AREA AROUND 18Z. LOW-LEVEL WAA IS EXPECTED TO CONTINUE AHEAD OF THE FRONT WHICH WILL IN TURN WILL CONTINUE TO RAISE SNOW LEVELS. THIS WILL BE MOST NOTICEABLE SOUTH OF A COEUR D'ALENE TO SPOKANE TO EPHRATA LINE. WILL ADJUST WINTER WEATHER HEADLINES SOUTH OF THIS LINE TO ADD SNOW LEVELS FROM AROUND 2500 FEET NEAR SPOKANE TO 3500 FEET SOUTH OF LEWISTON. WILL LEAVE THE MOUNTAIN ZONES (WA37-38 ID 1 AND 4) HEADLINES INTACT. HEAVIEST PRECIPITATION AGAIN LOOKS LIKE IT WILL BE RESERVED FOR PORTIONS OF ID ZONE 4...WHERE ANYWHERE FROM 3-6 INCHES OF ADDITIONAL ACCUMULATION WILL BE POSSIBLE THROUGH THIS AFTERNOON. PLENTY OF DRY AIR WILL MOVE IN ABOVE 700 MBS AFTER FROPA. THIS DRY AIR COUPLED WITH SWIFT WEST FLOW OVER THE CASCADES WILL BRING A SIGNIFICANT RAIN SHADOW TO MOST OF EAST WASHINGTON AND EXTREME WEST PORTIONS OF IDAHO ESSENTIALLY ENDING THE PRECIPITATION THREAT. UPSLOPE FLOW COUPLED WITH GOOD INSTABILITY ASSOCIATED WITH UPPER LEVEL TROF AXIS SHOULD KEEP SHOWERS GOING OVER IDAHO THROUGH MUCH OF THE EVENING. THINGS REALLY WONT DECREASE UNTIL UPPER LEVEL TROF AXIS MOVES INTO MONTANA LATER TONIGHT. ASIDE FROM THE PRECIPITATION...THE MAIN STORY TODAY WILL BE THE WIND. WILL FOLLOW WITH THE RUC SOLUTION...WHICH KEEPS LOW DEEPER AS IT CROSSES THE CONTINENTAL DIVIDE LATER THIS AFTERNOON. NGM PROBABLY THE CLOSEST SOLUTION WITH DEPTH OF SURFACE LOW AND THUS CAN USE MOS WINDS AS DECENT GUIDANCE...WILL JUST NUDGE WINDS UP A BIT. THIS WOULD BE A BETTER WIND EVENT AT THE SURFACE IF POST FRONTAL COLD AIR ADVECTION WERE STRONGER AND SURFACE LOW WERE A LITTLE FARTHER SOUTH. NONETHELESS POST-FRONTAL WINDS WILL BE SIGNIFICANT. TOP SPEEDS OF 30-35 MPH ARE EXPECTED FROM SPOKANE SOUTH TO LEWISTON...WHILE MOUNTAIN WINDS COULD APPROACH 45 KNOTS. THE WEATHER WILL QUIET DOWN SIGNIFICANTLY LATER TONIGHT AND WEDNESDAY AS UPPER LEVEL TROF MOVES INTO THE NORTHERN PLAINS WITH COOL NW FLOW MOVING TAKING ITS PLACE. SURFACE PRESSURE GRADIENTS RELAX SIGNIFICANTLY WITH HIGH PRESSURE MOVING INTO AREA. .EXTENDED...SLIGHT CHANGE TO CURRENT EXTENDED FOR DAY THREE TO INTRODUCE A CHANCE OF PRECIP NEAR THE CASCADES LATE IN THE DAY OTHERWISE NO CHANGES. ...THE INFORMATION IN THIS PRODUCT CONCERNING WARNINGS AND FORECASTS IS VALID ONLY AT THE TIME OF ISSUANCE. THE LATEST WARNING AND FORECAST INFORMATION WILL BE FOUND IN THE APPROPRIATE PRODUCTS... GEG 038/025/033 921 CQV 035/024/031 921 S86 034/025/031 953 COE 037/024/033 921 WWP 032/028/031 +63 LWS 044/032/038 721 MOS 040/027/033 EAT 039/026/035 610 .GEG...WINTER STORM WARNING CONTINUES THIS MORNING ABOVE 2500 FEET FOR WA ZONES 33 36 AND ID ZONES 2-3. ...WINTER STORM WARNINGS CONTINUE TODAY FOR ID ZONES 1 AND 4. ...WINTER STORM WARNING CONTINUES TODAY ABOVE 3000 FEET FOR ID ZONE 27. ...WINTER STORM WARNING CONTINUES TODAY FOR WA ZONE 31 ABOVE 4000 FEET. ...WINTER STORM WARNING CONTINUES THIS MORNING FOR WA ZONE 37. ...SNOW ADVISORY CONTINUES THIS MORNING FOR WA ZONES 38 AND 42. ... wa EASTERN WASHINGTON AND NORTH IDAHO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SPOKANE WASHINGTON 230 AM PST TUE JAN 4 2000 IMPRESSIVE LOOKING FRONTAL SYSTEM ON SATELLITE LOOPS CONTINUES TO OCCLUDE OVER WEST CENTRAL BC THIS MORNING...WHILE UPPER LEVEL TROF CONTINUES TO DEEPEN ALONG 130W. THE LOW CENTER HAS DEEPENED MORE THAN THE 00Z MODELS WOULD INDICATE PER SURFACE OBS. LATEST RUC HAS THIS NOTION IN MIND. THE MAIN CONSEQUENCE OF THE DEEPER SURFACE LOW IS A STRONGER WIND FIELD...WHICH SUBSEQUENTLY RESULTS IN STRONGER WARM AIR ADVECTION. THIS WAA HAS BEEN STEADILY WARMED TEMPS ACROSS MOST OF EAST WASHINGTON THIS MORNING WITH SNOW LEVELS RISING ABOVE THE LOWER ELEVATIONS ACROSS MUCH OF THE COLUMBIA BASIN AND INTO THE SPOKANE AREA. THE MOUNTAIN VALLEYS ACROSS THE NORTHERN MOUNTAINS AND IDAHO PANHANDLE ARE A LITTLE MORE PROTECTED FROM THIS WAA AND SHOULD CONTINUE TO SEE SNOW. SIGNIFICANT PRECIPITATION WILL CONTINUE UNTIL FRONT PASSES THROUGH THE AREA LATER THIS MORNING. TIMING OF THE FRONT PER SATELLITE LOOKS FAIRLY CONSISTENT WITH THE MODELS...SUGGESTING FROPA OVER THE CASCADES AROUND 13Z AND INTO THE SPOKANE AREA AROUND 18Z. LOW-LEVEL WAA IS EXPECTED TO CONTINUE AHEAD OF THE FRONT WHICH WILL IN TURN WILL CONTINUE TO RAISE SNOW LEVELS. THIS WILL BE MOST NOTICEABLE SOUTH OF A COEUR D'ALENE TO SPOKANE TO EPHRATA LINE. WILL ADJUST WINTER WEATHER HEADLINES SOUTH OF THIS LINE TO ADD SNOW LEVELS FROM AROUND 2500 FEET NEAR SPOKANE TO 3500 FEET SOUTH OF LEWISTON. WILL LEAVE THE MOUNTAIN ZONES (WA37-38 ID 1 AND 4) HEADLINES INTACT. HEAVIEST PRECIPITATION AGAIN LOOKS LIKE IT WILL BE RESERVED FOR PORTIONS OF ID ZONE 4...WHERE ANYWHERE FROM 3-6 INCHES OF ADDITIONAL ACCUMULATION WILL BE POSSIBLE THROUGH THIS AFTERNOON. PLENTY OF DRY AIR WILL MOVE IN ABOVE 700 MBS AFTER FROPA. THIS DRY AIR COUPLED WITH SWIFT WEST FLOW OVER THE CASCADES WILL BRING A SIGNIFICANT RAIN SHADOW TO MOST OF EAST WASHINGTON AND EXTREME WEST PORTIONS OF IDAHO ESSENTIALLY ENDING THE PRECIPITATION THREAT. UPSLOPE FLOW COUPLED WITH GOOD INSTABILITY ASSOCIATED WITH UPPER LEVEL TROF AXIS SHOULD KEEP SHOWERS GOING OVER IDAHO THROUGH MUCH OF THE EVENING. THINGS REALLY WONT DECREASE UNTIL UPPER LEVEL TROF AXIS MOVES INTO MONTANA LATER TONIGHT. ASIDE FROM THE PRECIPITATION...THE MAIN STORY TODAY WILL BE THE WIND. WILL FOLLOW WITH THE RUC SOLUTION...WHICH KEEPS LOW DEEPER AS IT CROSSES THE CONTINENTAL DIVIDE LATER THIS AFTERNOON. NGM PROBABLY THE CLOSEST SOLUTION WITH DEPTH OF SURFACE LOW AND THUS CAN USE MOS WINDS AS DECENT GUIDANCE...WILL JUST NUDGE WINDS UP A BIT. THIS WOULD BE A BETTER WIND EVENT AT THE SURFACE IF POST FRONTAL COLD AIR ADVECTION WERE STRONGER AND SURFACE LOW WERE A LITTLE FARTHER SOUTH. NONETHELESS POST-FRONTAL WINDS WILL BE SIGNIFICANT. TOP SPEEDS OF 30-35 MPH ARE EXPECTED FROM SPOKANE SOUTH TO LEWISTON...WHILE MOUNTAIN WINDS COULD APPROACH 45 KNOTS. THE WEATHER WILL QUIET DOWN SIGNIFICANTLY LATER TONIGHT AND WEDNESDAY AS UPPER LEVEL TROF MOVES INTO THE NORTHERN PLAINS WITH COOL NW FLOW MOVING TAKING ITS PLACE. SURFACE PRESSURE GRADIENTS RELAX SIGNIFICANTLY WITH HIGH PRESSURE MOVING INTO AREA. .EXTENDED...SLIGHT CHANGE TO CURRENT EXTENDED FOR DAY THREE TO INTRODUCE A CHANCE OF PRECIP NEAR THE CASCADES LATE IN THE DAY OTHERWISE NO CHANGES. ...THE INFORMATION IN THIS PRODUCT CONCERNING WARNINGS AND FORECASTS IS VALID ONLY AT THE TIME OF ISSUANCE. THE LATEST WARNING AND FORECAST INFORMATION WILL BE FOUND IN THE APPROPRIATE PRODUCTS... GEG 038/025/033 921 CQV 035/024/031 921 S86 034/025/031 953 COE 037/024/033 921 WWP 032/028/031 +63 LWS 044/032/038 721 MOS 040/027/033 EAT 039/026/035 610 .GEG...WINTER STORM WARNING CONTINUES THIS MORNING ABOVE 2500 FEET FOR WA ZONES 33 36 AND ID ZONES 2-3. ...WINTER STORM WARNINGS CONTINUE TODAY FOR ID ZONES 1 AND 4. ...WINTER STORM WARNING CONTINUES TODAY ABOVE 3000 FEET FOR ID ZONE 27. ...WINTER STORM WARNING CONTINUES TODAY FOR WA ZONE 31 ABOVE 4000 FEET. ...SNOW ADVISORY CONTINUES THIS MORNING FOR WA ZONES 38 AND 42. wa AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE CHEYENNE WY 910 AM MST TUE JAN 4 2000 MBW PROFILER CONTG TO RUN 50-55KTS AT LWST LVLS. THESE SPDS REFLECTD AT TIMES IN GSTS AT RWL/ARL. DON/T ANTICIPATE SUCH EXTRM SPDS THAT OCCURRED ARND MIDNGT AT ARL. BLV THIS WAS CAUSED BY NRLY SIMULTANEOUS OCCURRENCE OF DECOUPLG...PSG OF RGT FNT QUAD JET AND SUBSIDENCE ASSOCD WITH APCHG S/W RDG. 14Z RUC ONLY FCSTG 45-50KTS OVR WND CORRIDOR THRU DAY AT 7H...WHICH APPRS ONLY 5-10KTS ON LGT SIDE. NEW NGM NOT ANY STGR. SHARP LEE TROFG DVLPG E LAR RNG DURG DAY...WHICH BRINGS THREAT HI WNDS E OF MTNS INTO FOOTHILLS. SFC HI OVR WRN CO PROGD TO WKN DURG DAY ALSO...WHICH MAY SAVE FOOTHILLS FM HI WNDS. UPDATE...WL ADD WYZN 67 TO HWW. .CYS... WY...HI WND WRNG TDA IN AND NEAR SE MTNS, ZNS 63..64..66..67. NE...NONE. COX wy AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHEYENNE WY 235 PM MST TUE JAN 4 2000 50-60KT LYR CONTS TO DPN OVR MBW PROFILER...NOW UP TO ABT 6H. SIMILAR SPDS AT 5H. NRMLY SCREAMG WND CORRIDOR...ARL/VDW/BRX...CONTS TO SCREAM. STILL SUSTAING ABT 50KTS AT ARL WITH G60. BRX/VDW SLGTLY LESS. APPRS TO HV BLOWN ITSELF OUT HERE. 20Z RUC RUNNG ABT 10KTS WKR AT 7H THAN PROFILER. RUC KPS 40-50KTS OVR HI WND THRU EVENG HRS...SO WL CONT WRNG. APCHG PAC COOL FNT WL SHFT GRADIENT AND WKN HI PRES OVR WRN CO ENUF BY THAT TIME TO MAKE HI WNDS THRU CORRIDOR LESS FVRBL. 30KM MM5 SIMILAR TO AVN IN SPRDG QPF THRU E-CNTRL WY/NRN PANHANDL THIS EVENG. ETA DOESN/T HV QPF TIL LT NGT HRS. MDLS GENLY CONSISTENT WITH MN QPF FALLG IN S-CNTRL WY THRU 30HRS. WL PUT SLGT ACCUMULATN IN FOR MTNS. FOLLOWG PSG OF FINAL S/W ARND 42HRS...DRY BUT CONTD WINDY WX. .EXTENDED FORECAST... PROGRESSIVE FLOW PATTERN WILL CONTINUE WITH FAST NORTHWEST TO WEST FLOW ALOFT. A SERIES OF RAPIDLY MOVING SHORTWAVE DISTURBANCES WILL MOVE THROUGH THE REGION SUNDAY THROUGH TUESDAY AND WILL BRING A CHANCE OF SHOWERS. BREEZY TO WINDY CONDITIONS WILL PREVAIL THROUGH THE PERIOD. .CYS... WY...HI WND WRNG EVENG IN AND NEAR SE MTNS ZNS 63..64..66..67. NE...NONE. COX wy