NORTHEAST AND NORTH CENTRAL COLORADO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DENVER COLORADO 200 PM MST SUN DEC 31 2000 SHORT TERM DISCUSSION: DRY AIRMASS OVER THE STATE TONIGHT WITH MAYBE JUST A FEW CIRRUS DRIFTING IN LATE. MAIN CONCERN IS AMOUNT OF WIND IN THE FOOTHILLS. 18Z ETA SHOWS 40 KNOT CROSS MOUNTAIN FLOW AND GOOD STABILITY PROFILE FOR HEALTHY MOUNTAIN WAVE BY 03Z. NGM AND RUC ONLY SHOWING ABOUT 30-35 KNOTS. WITH THIS AMOUNT OF FLOW... GUSTS TO 60 MPH WILL BE MENTIONED BUT NO HIGHLIGHTS. STRONGER CROSS MOUNTAIN FLOW CLOSER TO 40 KNOTS DEVELOPS...THEN COULD SEE A BRIEF PERIOD OF GUSTS TO 70 MPH IN THE FOOTHILLS. WILL NOT MENTION WIND ON THE PLAINS WITH COLD AIRMASS IN PLACE AND LEE TROF AGAINST THE HILLS. WITH DEWPOINTS IN THE LOWER 20S AND GOOD RADIATIONAL COOLING TONIGHT...EXPECT FOG TO DEVELOP OVER SNOW COVERED AREAS. LOCALLY DENSE FOG POSSIBLE IN THE CACHE LA POUDRE AND SOUTH PLATTE RIVER VALLEYS NORTH OF DENVER. BARJENBRUCH LONG TERM DISCUSSION: WNDS WL CONT IN MTNS AND IN/NR FTHILLS THRU MON MRNG...BUT UPR SUPPORT FOR WINDS AND PRES GRADIENTS BCM LESS FVRBL AFT 18Z. ARND THAT TIME...DYING UPR TROF FM PAC NW WL MOV INTO WY/NRN CO. THIS SYS WL LARGELY SHEAR APART AS IT RIDES OVR THE TOP OF STRENGTHENING HI PRES RDG IN CA. NOTHING MORE THAN LGT SNOW SHOWERS EXPECTED FOR TMRW AFTN ALONG THE DIVIDE...ZNS 33/34 AS DYNAMICS...LAPSE RATES ETC. PRETTY FEEBLE WITH THIS TROF. THE HIGHEST ELVS MAY GET A COUPLE OF INCHES...WITH ONLY A DUSTING FOR MTN AREAS BLO TIMBERLINE. PLAINS WL BE PTLY CLDY WITH SEASONAL TEMPS. THIS SYSTEM WL BE GONE BY TMRW NGT AND FCST AREA WL BEGIN TO BE INFLUENCED BY A BURGEONING MASS OF HIGH PRESSURE BLDG INTO THE INTERMOUNTAIN WEST. BY WED...586DM H5 HEIGHTS BLD INTO UT...SPRDG EWD INTO CO THURS. UPR FLO SEEMS TO SUPPORT DOWNSLOPE FLO OVR FNT RANGE WELL INTO THE PLAINS...SO MAX TEMPS BY THURS MAY SOAR INTO THE 60S OVR THE AREA WITH PERHAPS LWR 40S FOR MTNS. A BIG CHANGE INDEED. LONGWAVE PTRN IN GENERAL SEEMS TO BE UNDERGOING A SIGNIF CHANGE...WHETHER IT SUPPORTS SNOW OR WARM TEMPS BEYOND SUN REMAINS TO BE SEEN. AT LEAST THE NORTHWEST FLOW WL GO AWAY FOR A WHILE. 46 .DEN...NONE. co WEST CENTRAL AND SOUTHWEST FLORIDA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL 742 PM EST SUN DEC 31 2000 ...MORE RECORD LOW TEMPERATURES LIKELY BY NEW YEARS MORNING... THE LAST NIGHT OF 2000 WILL BE ANOTHER VERY COLD ONE FOR ALL OF THE FORECAST AREA. SURFACE RIDGE AXIS EXTENDING NW TO SE ACROSS THE PENINSULA WILL RESULT IN CLEAR SKIES AND A LIGHT NORTHERLY DRAINAGE FLOW DOWN THE SPINE OF THE PENINSULA OVERNIGHT...WHICH WILL SUPPORT IDEAL RADIATIONAL COOLING. CURRENT TEMPS FROM MTR'S AND FAWN NETWORK ARE NOW RUNNING UNDER GUIDANCE VALUES BY SOME 2-4 DEGREES IN MOST LOCATIONS AND SHOULD SEE FREEZING OR SUB-FREEZING TEMPS PRIOR TO MIDNIGHT OVER MY NORTHERN INTERIOR ZONES AND AFTER MIDNIGHT THROUGH SUNRISE ACROSS THE REST OF THE FA. IN ADDITION LIGHTER WIND PROFILES WILL SUPPORT SCT TO WIDESPREAD FROST AS WELL. PREVIOUS ZONE PACKAGE COVERS ALL OF THIS NICELY WITH HARD FREEZE/FREEZE WARNINGS IN PLACE SO NO UPDATES ARE PLANNED. NOTE...OLD RECORD LOW TEMPS FOR KTPA... KPIE...KLAL...AND KFMY FOR JAN 1ST ARE 26...42...33...AND 38 DEGREES RESPECTIVELY. MARINE...TRENDS FROM C-MAN AND OFFSHORE BUOYS INDICATE WEAKER WINDS THAN PREVIOUSLY ADVERTISED. WILL MONITOR TRENDS A WHILE LONGER AND REVIEW LATER RUC/MESO-ETA OUTPUT AND IF CURRENT TREND CONTINUES AND IS SUPPORTED BY MODELS WILL LIKELY ADJUST WIND SPEEDS DOWN A BIT IN THE 1030 PM CWF UPDATE...OTHERWISE NO OTHER CHANGES ARE EXPECTED. FIRE WX...MARGINALLY LOW RH DURATIONS AGAIN EXPECTED ACROSS THE ENTIRE FA ON MONDAY AFTERNOON...SO A FIRE WEATHER WATCH CONTINUES IN EFFECT. .TBW...HARD FREEZE TONIGHT LEVY CITRUS HERNANDO SUMTER PASCO. ...FREEZE WARNING TONIGHT REST OF CWA. ...FIRE WEATHER WATCH ENTIRE CWA MONDAY AFTERNOON. MCMICHAEL fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MIAMI FL 1033 AM EST SUN DEC 31 2000 LOWEST TEMPERATURE RECORDED/REPORTED SO FAR 32 DEGREES AT IMMOKALEE WITH AN UNOFFICIAL 32 AT SAPP IN SOUTHWEST MIAMI-DADE. TEMPERATURES HAVE REACHED THEIR LOW POINT AND ON WAY BACK UP SLOWLY SO FREEZE WARNING WHICH EXPIRED AT SUNUP NOT TO BE RENEWED. BUT A NORTHWESTERLY WIND FLOW UP TO 10 TO 15 MPH IN PLACES KEEPING WIND CHILLS BELOW 35 DEGREES IN MANY AREAS AS OF 900 AM. WILL EXTEND WIND CHILL ADVISORY A LITTLE LONGER. 13Z RUC AND 06Z MESOETA KEEP A NORTHWESTERLY WIND FLOW UP TO 15 KNOTS AT LEAST OVER E COASTAL WATERS. WILL KEEP ADVISORY FOR SURE IN GULF STREAM. .MIA...WIND CHILL ADVISORY UNTIL 11 AM. FIRE WEATHER WATCH GLADES... HENDRY... E COLLIER... WESTERN PALM BEACH... AND W BROWARD COUNTIES THIS AFTERNOON. SMALL CRAFT ADVISORY GULF STREAM TODAY. $$ fl AREA FORECAST DISCUSSION...UPDATE NATIONAL WEATHER SERVICE GOODLAND KS 1020 AM MST SUN DEC 31 2000 CLEARING LOOKS TO BE STARTING FROM THE NORTH ATTM. HWVR...LOOKS TO BE A LTL SLOWER THAN CURRENTLY EXPECTED. THINK THIS MAY BE DUE TO LACK OF SIGNIFICANT DOWNWARD FRCG AND STRONG SFC WINDS TO SCOUR THINGS OUT. RUC WOULD SAY THAT CLEARING WILL NOT PROGRESS RAPIDLY UNTIL THIS AFTERNOON. CURRENT TEMPS ARE NOT TOO FAR AWAY FROM FCST MAXES. GIVEN CURRENT TRENDS WL ADJUST CLD COVER FCST SLIGHTLY JUST EAST OF THE KANSAS AND COLORADO BORDER...AND RAISE MAXES SLIGHTLY IN MY COLORADO COUNTIES. REST OF FCST LOOKS FINE. .GLD...NONE. BULLER ks AREA FORECAST DISCUSSION...CORRECTED TO ADD POPS... NATIONAL WEATHER SERVICE SHREVEPORT LA 246 PM CST SUN DEC 31 2000 SNOW EVENT SHAPING UP NICELY AND ALL BUT IMMINENT FOR ADVISORY THIS EVENING. SNOW REPORTED TO HAVING JUST BEGUN IN TXK...CORRESPONDING TO ABOUT 15 DBZ...WHERE ORANGE CHANGES TO RED...ON CLEAR AIR MODE REFLECTIVITY. THIS EXTRAPOLATION WOULD PLACE LEADING EDGE OF SNOW ALONG A QUITMAN TO LINDEN TEXAS TO LEWISVILLE ARKANSAS LINE AT THE PRESENT TIME. SNOW SHOULD THUS INCLUDE MOST OF AREA BY EARLY EVENING...WILL START IT LATER IN EVENING ONLY SOUTH AND EAST OF TOLEDO BEND TO AROUND MONROE. HAVE BEEN INDECISIVE ABOUT WHETHER TO INITIATE PCPN AS RAIN LFK AREA OF TX...BUT AFTER LOOKING AT LATEST RUC SOUNDING WITH FREEZING LEVEL BELOW 1000 FEET BY 0Z WHEN PCPN STARTS AND ENUF LOW LEVEL DRY AIR FOR RAPID EVAPORATIVE COOLING... WILL GO WITH SNOW. HEAVIEST SNOW IN OK...4 TO 6 INCHES...AND UNDER AN INCH SO FAR AROUND DALLAS. WILL KEEP AMOUNTS IN ADVISORY STATUS... GOING 2 TO 3 INCHES ALONG RED RIVER VALLEY SOUTH TO INTERSTATE 20. LOWER AMOUNTS TO AROUND AN INCH FOR MUCH OF SE PORTION OF AREA. CLEARING BEHIND THIS SNOW EVENT...WHICH WILL EXIT AREA BEFORE 12Z... WILL BE RATHER TRANSIENT AS SHORT WAVE MONDAY NIGHT BRING SOME CLOUDS BACK INTO AREA. THUS WILL MODERATE A BIT ON VERY COLD TEMPS FOR NEW YEARS NIGHT. SHV 24/38/22/42 8100 TYR 24/39/25/44 9000 MLU 26/41/19/42 7100 LFK 27/40/24/45 7000 TXK 22/37/20/40 9000 SHV...SNOW ADVISORY ARZ050-051-059>061-070>073-LAZ001>006-010>014- 017>022-OKZ077-TXZ096-097-108>112-124>126-136>138-149>153-165>167- la AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1000 PM EST SUN DEC 31 2000 00Z RAOBS/RUC ANAL/WV LOOP SHOW MEAN TROF FM GRT LKS-NEW ENGLAND E OF RDG OVR ROCKIES. CWA UNDER SHRTWV RDG TO NE OF SHRTWV OVR IA THAT HAS MOVD SWD IN NLY FLOW ALF E OF WRN RDG. SFC 1036MB HI CENTERED OVR NW MN...WITH SOME CLRG AS FAR E AS ASX. HOWEVER...IR PIX INDICATE AXIS OF COLDER (MQT VWP INDICATES RETURNS UP TO 8 K FEET MSL) CLD TOPS STRETCHING FM CYQT SE ACRS ECNTRL CWA INTO NRN LWR MI. WIDTH OF COLDER CLD BAND TAPERS OFF STEADILY TO THE NW...WITH DRYER AIR MOVG S AND SW FM ONTARIO. SO AREA OF COLDER CLD OVR CWA GETTING PROGRESSIVELY THINNER AS W EDGE OF ENHANCED CLD NOT MAKING MUCH PROGRESS TO THE W. NOT TOO MUCH IN THE WAY OF LWR CLD OVR NE LK SUP ONCE HIER CLD IS STRIPPED AWAY. MQT 88D REFLECTIVITY SHOWS SCT-NMRS SHSN WITH A FEW 28DBZ RETURNS MOVG INTO NCNTRL CWA IN CYC NNELY FLOW PER SFC OBS/VWP WITH H85 TEMPS ABOUT -15C (DELTA-T ARND 17C). MAIN FCST CONCERNS THIS PACKAGE ARE SHSN COVG AND AMTS. 00Z RUC H85-7 RH ANAL/PROG APPEARS TO HAVE BEST HANDLE ON EXTENT OF COLD CLDS. AS SHRTWV RDG SHARPENS/SFC PRES RISE OVRNGT...MSTR BAND PROGGED TO TO NARROW WITH DRYING FM THE NE REACHING NCNTRL ZNS BTWN 06Z-09Z...IN GOOD AGREEMENT WITH SAT TRENDS SHOWING DRYING AT CMX ARND 06Z AND MQT BTWN 07Z-08Z. SO WOULD XPCT SHSN ACTIVITY OVR PRIMARILY NCNTRL ZNS...WHERE NNELY FLOW ENHANCES UPSLOPE...TO DIMINISH DURG THE OVRNGT HRS. NEW 00Z ETA INDICATES H95 CNVGC MAX AT 06Z OVR MQT COUNTY TO WEAKEN TOWARD 09Z BUT LINGER THRU 12Z. LES CHART SUGS 1-3"/6 HRS...BUT WL MENTION NO MORE THAN 3" ADDITIONAL AFTR 03Z IN MQT TO ACCOUNT FOR CONSIDERABLE DRYING XPCTD AFTR 08Z. FLOW MUCH WEAKER AND SHEARED (IN TIME AND HGT) OVR WRN ZNS...AND DRY AIR ADVCTN/LLVL DVGC DVLPS OVR THE E WHERE FETCH ACRS WATER WL BE RELATIVELY SHORT IN NNELY FLOW. MIN TEMPS LOWEST ACRS THE E WHERE FETCH SHORTEST/LK MODERATION LEAST. SOME CLRG LATE NR IWD AS FLOW BACKS TO MORE WNW MAY ALLOW TEMPS TO FALL INTO SINGLE NUMBERS. REST OF CWA SHUD REMAIN IN LK MODIFIED AIRMASS WITH TEMPS NOT FALLING MORE THAN A FEW DEGREES FM CURRENT READINGS. .MQT...NONE. KC mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 950 PM EST SUN DEC 31 2000 RELATIVELY QUITE WX ACROSS NRN MI LATE THIS NEW YEARS EVE. ONLY WX ACTION IS HAPPENING ALONG PORTIONS OF THE NW COAST OF LOWER MI... WHERE WEAK LAKE EFFECT SNOW BANDS HAVE DEVELOPED IN NORTHERLY FLOW AND ARE AFFECTING AREAS ALONG THE LAKESHORE FROM THE LEELANAU PENINSULA TO FRANKFORT TO MANISTEE. LATEST 0.5 BASE REF FROM APX SHOWS MAX DBZ IN THESE BANDS OF AROUND 20. IR SATELLITE LOOP SHOWS THE BACKEDGE OF THE MID CLOUD SHIELD WORKING S INTO ERN UPR MI AS MID LEVELS DRY. LATEST RUC CONFIRMS A GRADUAL DECREASE IN LOW LEVEL RH...LOWERING INVERSION HEIGHTS AND INCREASING ANTICYCLONIC FLOW OVERNIGHT AS THE PERSISTENT SFC TROUGH PUSHES SE OUT OF THE CWA AND SFC RIDGING BEGINS TO BUILD INTO THE REGION. THUS...WILL CONTINUE A DIMINISHING TREND IN BOTH LAKE PRECIP ON THE NW COAST AND IN CLOUDS ACROSS NRN SECTIONS OF THE CWA. WILL HAVE TO ADJUST OVERNIGHT LOWS UP A FEW DEGREES. MOST AREAS ARE STILL IN THE UPPER TEENS TO LOWER 20S...WITH DWPTS IN THE TEENS. .APX...NONE. EME mi SOUTHEAST MICHIGAN AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 922 PM EST SUN DEC 31 2000 CYCLONIC SURFACE FLOW CONTINUES OVER SOUTHEAST MICHIGAN WITH THE MAIN QUESTION STILL THE LAKE EFFECT SNOW OVER THE TIP OF THE THUMB. MEAN RH SLOWLY DIMINISHES OVERNIGHT FROM NORTH TO SOUTH AS THE CONDENSATION PRESSURE DEFICITS SLOWLY INCREASE. AT THE SAME TIME... 850MB TEMPERATURES CONTINUE TO SLOWLY COOL...REACHING VALUES PROGGED BY THE MESOETA TO AROUND -15C BY 12Z. MID-LEVEL LIFT IS WEAK THROUGHOUT THE NIGHT...HIGHEST JUST BEFORE DAWN ON THE 18Z MESOETA. BOTH THE MESOETA AND THE GREAT LAKES ETA SUGGEST WEAK QVECTOR CONVERGENCE AT THE 850MB LEVEL IN VICINITY OF THE THUMB BY 09Z...WITH INVERSION HEIGHTS ON MODEL SOUNDINGS PERSISTING AROUND 6K FEET. PEEK AT THE LOCAL LAKE-EFFECT SNOW CHECKLIST SUGGESTS GOING FORECAST ON TRACK WITH 2 TO 4 INCHES PER 12 HOURS WITH BASICALLY NEUTRAL LIFT...INVERSION BETWEEN 3K AND 6K FEET...AND LAKE/850MB DELTA-T BETWEEN 17C AND 20C. HOWEVER...THE QPF FORECAST FROM THE GREAT LAKES ETA WOULD PRODUCE MORE THAN THAT THROUGH ABOUT 15Z MONDAY IN THE FAR EASTERN PART OF HURON COUNTY. PERSISTENCE WILL BE THE KEY WITH THIS FORECAST. THE GREAT LAKES ETA SHOWS 1000-850MB MEAN WINDS BASICALLY DUE NORTH THROUGHOUT THE NIGHT. ON THE OTHER HAND...THE 18Z MESOETA SUPPORTS THAT LAYER/S WIND BACKING A LITTLE NORTH-NORTHWESTERLY OVERNIGHT BEFORE RETURNING TO THE NORTH DURING THE MORNING MONDAY. THE LATEST RUC IS IN BETWEEN. CALLS TO FOUR SEASONS SPOTTERS IN BOTH HARBOR BEACH AND PORT AUSTIN JUST AFTER 9 PM INDICATES NO SNOW FALLING AT THAT TIME... WITH JUST SOME BLOWING OF THE SNOW THAT HAD FALLEN EARLIER SUNDAY. AS A RESULT...THINKING THAT ANY SNOW BAND IS JUST OFFSHORE OR HAS YET TO REDEVELOP...WILL CONTINUE WITH THE CURRENT FORECAST OF AMOUNTS JUST UNDER ADVISORY CRITERIA FOR HURON COUNTY. IF THE GREAT LAKES ETA QPF IS CORRECT...AND THE MESOETA AND THE OTHER SHORT-TERM MODELS ARE CORRECT IN KEEPING THE MEAN FLOW PERSISTENTLY NORTH FROM JUST AFTER SUNRISE THROUGH THE AFTERNOON...ANOTHER SHORT-FUSED LAKE EFFECT SNOW HEADLINE MAY BE REQUIRED FOR HURON COUNTY FOR NEW YEARS DAY. IN THE REST OF SOUTHEAST MICHIGAN...ONGOING FLURRIES COURTESY OF LEFTOVER WEAK FORCING SHOWN ON 850-700MB LAYER QVECTOR CONVERGENCE. SOME OF THIS CONVERGENCE ACTUALLY REMAINS OVER FAR SOUTHEAST MICHIGAN DURING THE NIGHT AS A WEAK SHEAR AXIS LIES OVERHEAD TO THE EAST OF A WEAK UPPER LOW OVER IOWA. MOISTURE AND LIFT IS NOT GREAT...THOUGH...AND EXPECT LITTLE MORE THAN FLURRIES IN MOST OF SOUTHEAST MICHIGAN FOR THE REST OF THE NIGHT. A FEW LOCATIONS WILL ACTUALLY SEE A COUPLE OF BREAKS IN THE CLOUDS...ALREADY HAVING TAKEN PLACE IN LENAWEE COUNTY WHERE FOR A PERIOD THROUGH ABOUT 09Z THERE IS A RELATIVE MIN OF OVERALL MOISTURE BEFORE THE 500MB LEVEL RH REALLY INCREASES AGAIN AROUND 09Z. CLOUD SHIELD NOT TOO FAR FROM ADRIAN BASED ON THE 3.9 MICRON SATELLITE IMAGE...AND SUSPECT THE CLOUDS WILL INCREASE THERE OVERNIGHT. HAVE ALREADY UPDATED TO REFLECT THE CLOUD TREND IN LENAWEE COUNTY AND FOR A SLIGHTLY LOWER OVERNIGHT LOW THERE. .DTX...NONE. DJF mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 849 PM CST SUN DEC 31 2000 FOG PRODUCT INDICATES LOW CLOUDINESS IS EXPANDING WESTWARD THIS EVENING INTO CENTRAL AND WEST CENTRAL MN. CLOUDS AND FLURRIES CONTINUE OVER SOUTHERN MN AS WELL AS WEST CENTRAL WI. CONCERN REMAINS THAT OF THE DAY SHIFT WITH CLOUDS BEING TRAPPED BY INVERSION AS SURFACE HIGH BUILDS IN FROM THE NW. LATEST RUC HOLDING FIRM ON THE CLOUDS ACROSS EASTERN AND SOUTHERN AREAS OVERNIGHT. WILL ADJUST THE ZONES TO REFLECT MORE CLOUDS. WHERE BREAKS OCCUR IN THE NW CWA OR WHERE SKIES REMAIN CLEAR IN THESE AREAS...TEMPERATURES WILL BOTTOM OUT NEAR 20 BELOW ZERO WITH NO PROBLEM. WILL KEEP COLD MINS GOING FOR AXN GROUP. .MSP...NONE. HILTBRAND mn TEXAS/OKLAHOMA PANHANDLES FORECAST DISCUSSION NATIONAL WEATHER SERVICE AMARILLO TX 317 PM CST SUN DEC 31 2000 A FEW BREAKS BEGINNING TO APPEAR IN NW THIS AFTN WITH A FEW FLURRIES STILL OCCURRING IN SRN ZNS. EXPECT CLOUDS TO GRADUALLY CLEAR FM NW TO SE THROUGH THIS EVE AND MAY EVEN BE ABLE TO GO MOSTLY CLEAR IN NRN ZNS OVERNIGHT. CONCERN THOUGH REMAINS WITH DENSE FOG REDEVELOPING TONIGHT AS WINDS SWING AROUND TO SRLY DIRECTION WITH SFC HIGH CENTER SETTLING INTO ARKLATEX REGION. POTENTIAL EXISTS FOR HIGHER DPTS FM SE NM INTO W CENTRAL TX TO BE DRAWN BACK N INTO FA ACROSS EXISTING SNOW COVER. WITH EACH NEW RUN OF RUC 925MB SFC CONTINUES TO BECOME MORE SATURATED AND WIDESPREAD WHILE 12Z MODELS SUGGESTED BLYR TO DRY OVERNIGHT. WILL ONLY MENTION AREAS OF FOG OVERNIGHT AND LET EVE SHIFT GET A BETTER FEEL FOR THIS. WINDS EXPECTED TO REMAIN LIGHT INTO NEW YEARS DAY THEN VEER TO MORE ERLY DIRECTION AS PRESSURES FALL ALONG ERN SLOPES. SFC HIGH CENTER EXPECTED TO MOVE S AGAIN INTO MO MON NIGHT. A RIDGE-RIDING SHRTWV DROP SE ACROSS CO INTO FA THEN. MODELS GENERATE SOME LIGHT QPF ACROSS ERN ZNS BUT EXPECT MOISTURE TO RATHER LIMITED. WITH BRIEF UPSLOPE POSSIBLE AND SMALL WINDOW FOR RETURNING LLVL MOISTURE WILL PLACE FLURRIES IN ERN ZNS BUT NO POPS. MID LEVEL TROUGH AXIS ROTATES ACROSS ON TUE THEN CONDITIONS SHOULD IMPROVE THROUGH THU AS RIDGE AXIS ACROSS WRN U.S. SLOWLY MIGRATES E. TEMPS WILL BE BIGGEST CHALLENGE IN SHORT TERM WITH EXISTING SNOW COVER BEING OVERRIDDEN BY WARMER AIR PUSHING E FM ROCKIES. PLAN ON STAYING ON LOW END OF GUIDANCE FOR THE TIME BEING WITH OVERNIGHT LOWS A BIT HIGHER DUE TO AMOUNT OF LLVL MOISTURE THAT REMAINS IN PLACE. IN EXTENDED... PATTERN BECOMES LESS AMPLIFIED TOWARD END OF WEEK AS LOW IN ERN PAC MOVES ONSHORE ACROSS SRN CA. THIS SHOULD BEGIN TO SPREAD AT LEAST HIGH LEVEL MOISTURE ACROSS AREA BY FRI. SHRTWV MOVING FM WRN CANADA TO NR GREAT LAKES WILL PUSH ANOTHER SURGE OF COLD AIR SWRD ON FRI. 12Z AVNX CONTINUES TREND OF OLD MRF BRINGING 1025MB HIGH INTO CENTRAL PLAINS. UPPER LOW ACROSS SW U.S. SHEARS OUT AND MOVES ACROSS FA ON SAT WITH POSSIBLY MORE ENERGY HANGING BACK ACROSS GREAT BASIN. WILL KEEP SAT AND SUN CLOUDY FOR NOW AND NOT INTRODUCE PRECIP YET. WARMEST DAY EXPECTED ON THU WHEN TEMPS COULD APPROACH 60 THEN COOLDOWN BEGINS FRI WITH TEMPS BACK AOB NORMAL SAT/SUN. .AMA... TX...NONE. OK...NONE. COBB tx SOUTHEAST TEXAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX 245 PM CST SUN DEC 31 2000 THANKS TO FWD AND SHV FOR COORDINATION. OVERRUNNING PATCHES OF RAIN AND -SHRA BECOMING MORE WIDESPREAD AS LOW LEVEL JET CONTINUES TO PUMP INCREASING AMOUNTS OF MOISTURE. VERY DRY AIR UNDERNEATH MOIST 850-700 LAYER THIS MORNING AND EARLY AFTERNOON. GOES MID MORNING SOUNDING VERIFIES THIS. LIGHT PRECIP RAPIDLY UNDERGOING EVAPORATIONAL COOLING AND FALLING OCCASIONALLY AS SLEET IN NON-MEASURABLE AMOUNTS THIS AFTERNOON. RUC/MESO-ETA PROGGED SOUNDINGS INDICATE DEWPOINT PROFILES (LOWER LEVELS) RISING TO AT OR ABOVE 0 DEG C BY MID/LATE AFTERNOON. AS UPPER LEVEL VORT LOBE/ENERGY RAPIDLY MOVES ACROSS TO N AN NE OF CWFA THIS EVENING...MOISTURE WILL BE SHOVED RAPIDLY EASTWARD AFTER MIDNIGHT DRYING FROM NW TO SE. 850/700 MB SHOWS THICKNESS VALUES LESS THAN 1555 METERS ...1000/850 MB THICKNESS LESS THAN 1300 METERS AND 1000-500 MB THICKNESS LESS THAN 5460 M NORTHEAST ZONES NEAR MID NIGHT TONIGHT (POLK...TRINITY AND HOUSTON COUNTIES). MESO-ETA INDICATE BEST CHANCE OF SNOW WILL BE OVER AFOREMENTIONED COUNTIES. 850 MB CONFLUENCE ZONE QUITE EVIDENT THESE AREAS FOR TONIGHT. EXPECT ABOUT 1-2 INCHES OVERNIGHT FOR NE ZONES. WILL ADJUST WINTER WEATHER ADVISORY FOR TONIGHT ACCORDINGLY. WILL UPDATE SATWSWHOU. MAY GET SOME DUSTING OF SNOW (<1 INCH) SOUTH OF ADVISORY AREA TO NEAR CALDWELL...CONROE...LIBERTY LINE. MORE LIKELY RAIN MIXED W/SLEET. DRIER AIR MASS MOVING INTO REGION MONDAY WILL HANG ON FOR SEVERAL DAYS. EXPECT COLD NIGHTS ESPECIALLY MONDAY NIGHT...20S MOST INLAND AREAS. NEXT CHANCE OF PRECIP WILL BE NEXT WEEKEND AS PER MRF (SHOWING A SHORT WAVE MOVING ACROSS REGION). AS WINDS PICK UP OVERNIGHT (TONIGHT) ACROSS COASTAL WATERS...SCA CRITERIA WILL BE MET. SLIGHTLY BELOW THRESHOLD LEVELS FOR BAYS WILL CALL FOR SMALL CRAFT CAUTION. .KHGX...WINTER WEATHER ADVISORY TONIGHT FOR POLK...TRINITY AND HOUSTON COUNTIES. SCA COASTAL WATERS 0-60 NM...CAUTION BAYS. 37/47/48 NE UU 028/042 023/047 027 8-0 CLL UU 031/045 026/049 029 7-0 IAH BU 033/047 027/050 030 720 GLS BU 042/048 035/050 039 720 tx DEEP SOUTH TEXAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE BROWNSVILLE TX 1000 AM CST SUN DEC 31 2000 SHORT TERM...KBRO REFLECTIVITY SHOWS ISOLD TO SCT SHOWERS MOVING NORTH ALONG THE TX/MEX COASTLINE. MSAS AND RUC DATA BOTH INDICATE THE COASTAL TROUGH LINGERING THROUGH THE DAY WHICH WILL MAINTAIN PCPN CHCS WITH THE BIGGEST THREAT CONFINED MAINLY TO THE COAST. MSAS LI VALUES SHOW THE MOST STABLE AIR OVER THE WESTERN CWA...WHILE MORE UNSTABLE AIR REMAINS IN PLACE OVER THE EASTERN COUNTIES. HOWEVER...OVERALL LIS APPEARS TO BE TOO STABLE ATTM OVER THE CWA TO WARRENT A MENTION OF THUNDERSTORMS IN THE 1ST PD. ALTHOUGH AFTERNOON HEATING WILL BE VERY LIMITED DUE TO THE CLDS AND PCPN...CURRENT TEMPS AROUND THE VALLEY ARE PUSHING NEAR 60 DEG F. WITH WAA CONTINUING THROUGHOUT THE LATE MORNING AND AFTERNOON... BELIEVE THAT MID TO UPPER 60S ARE STILL POSSIBLE. ALL IN ALL...CURRENT ZFP LOOKS GOOD WITH NO CHANGES REQUIRED. MARINE...BUOY020 SHOWS AN E-SE WIND NEAR 20 KTS WITH SWELLS NEAR 6 FT. THE COASTAL TROUGH WILL CONTINUE TO GENERATE ISOLATED SHOWERS AND MODERATE SURFACE FLOW OVER THE BAY AND GULF WATERS THROUGH THE REST OF THE DAY. EXPECT SEAS TO REMAIN BELOW SCA CRIT FOR THE MOMENT...BUT WILL LIKELY NEED TO BE UPDATED LATER THIS AFTERNOON FOR THE APPROACHING FRONT. NO CHANGES NEEDED IN CURRENT CWF. SYNOPTIC...60/MESO...CAMPBELL INTERNET ADDRESS...WWW.SRH.NOAA.GOV/BRO .BRO...NONE. tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LINCOLN IL 310 AM CST MON JAN 1 2001 CURRENT FCST ON TRACK WITH ONLY MINOR CHANGES ANTICIPATED. VORT MAX CLEARLY VISIBLE ON WV LOOP ATTM...LOCATED ACRS SOUTH-CRL IA. PROGRESSION SWRD HAS BEEN SLOW OVR PAST SEVERAL HOURS. ALL MODELS...INCLUDING MOST RECENT RUC...SHOWING THE VORT MOVING SWRD THRU NRN MO BY 12Z. Q-CONVERGENCE CONSEQUENTLY SHUTS DOWN ACRS MOST OF ILX CWA BY 18Z...BRINGING TO AN END THE LGT SNOW...NOW ONGOING ACRS PORTIONS OF CWA...ESP SE AND E. BELIEVE FLURRY CHANCES WL CONT MUCH OF DAY ACRS ESP SRN CWA...WITH AMOUNT OF LOW-LVL MOIST... CYCLONIC FLOW AND FCST MOVEMENT OF THE VORT. MODELS ALL SHOW SLOW PROGRESSION OF DRIER AIR INTO CRL IL TONIGHT AS HIGH PRES MOVES EWRD. CLEARING WL OCCUR FM THE NORTH DURING THE EVE. LOOKING AT CURRENT TEMPS ACRS PLAINS...HAVE TO THROW OUT NGM GUIDANCE TEMPS AS BEING WAY TOO WARM. AVN/ETA HAVE A BETTER HANDLE ON THE COLD AIR...AND THIS FITS WELL WITH CURRENT FCST. COLDEST AIR IN THE NORTH WHERE CLEARING WL OCCUR EARLIER. ALL MODELS IN GOOD AGREEMENT WITH THE TIMING OF THE NEXT WAVE...FM ARROWHEAD OF MN TO NWRN KS AT 00Z WED. AS WITH THE CURRENT SYSTEM...MOST OF THE FORCING WL COME FM THE UPR LVLS...AS SFC MOIST CONV AND H700 OMEGA WEAK. AGREE WITH CURRENT LOW POPS THU NIGHT NORTH AND CRL WITH THIS FEATURE...AS QG FORCING EVIDENT ON MODELS ACRS NW 1/2 OF STATE BY 06Z WED. CONT SNOW IN WED EXTENDED WITH CHANCE POPS ACRS ALL OF CWA. MODELS CONT TO STRUGGLE WITH TEMPS. ETA SEEMS TO HAVE THE BEST HANDLE. AVN TOO COOL WITH HIGHS TODAY...NGM MUCH BETTER BUT PERHAPS A TOUCH TOO WARM AS IT CONT TO BE TOO WARM WITH LOWS. WL LEAN TOWARD NGM/ETA FOR HIGHS...AVN/ETA FOR LOWS. FOR THE SECOND RUN IN A ROW...THE MRF ADVERTISING A BREAKDOWN OF THE LONGWAVE PATTERN ACRS MIDWEST BY THE END OF THE WEEK. FINALLY TRYING TO BUILD THE UPR RIDGE EWRD...ALLOWING FOR A WARMER AND DRIER END OF THE EXTENDED. PRELIMINARY TEMPS/POPS FOR COORDINATION ONLY. SPI CU 018/003 024/015 025 81300 PIA CU 019/902 023/014 025 81300 DEC CU 020/002 023/012 024 81300 CMI CU 021/000 021/009 023 81400 MTO CU 021/005 023/010 024 81410 LWV CU 022/007 024/012 026 81510 .ILX...NONE. $$ PLAHMER il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 1010 AM CST MON JAN 1 2001 CLOUDS ACROSS SOUTHERN MINNESOTA APPEAR TO BE IN THE GENERAL VICINITY OF THE SURFACE RIDGE AND CORRELATED WITH THE 925 MB RELATIVE HUMIDITY. THE RUC MODEL SUGGESTS THAT THE RIDGE WILL SHIFT INTO IOWA AND THE HUMIDITY WILL DECREASE BY MID AFTERNOON. THIS IS IN AGREEMENT WITH CURRENT SATELLITE TRENDS WHICH SHOW DISSIPATION ON THE NORTHERN FRINGES OF THE CLOUD COVER. SUSPECT WE WILL STAY UNDER THE INFLUENCE OF THE ARCTIC RIDGE THIS AFTERNOON AND WILL ADJUST TEMPERATURES DOWN SLIGHTLY SOME AREAS. .MSP...NONE. WH mn DEEP SOUTH TEXAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE BROWNSVILLE TX 950 AM CST MON JAN 01 2001 SHORT TERM...CURRENT KBRO REFLECTIVITY SHOWS ONLY SOME LIGHT ECHOES ABOUT 100 MILES SE OF BRO OVER THE WESTERN GULF. HOWEVER...THE 15Z SURFACE OBS FROM BRO AND PIL SHOW SOME -RA. CLD COVER AND CAA PREVAILING OVER THE CWA WILL NOT ALLOW SURFACE TEMPS TO REBOUND MUCH TODAY...WHICH WILL MOST LIKELY RESULT IN NEAR STEADY OR SLOWLY FALLING TEMPS THROUGHOUT THE DAY. PGF BETWEEN SURFACE HIGH BUILDING DOWN OVER THE SE U.S. AND THE BROAD SURFACE LOW OVER THE WESTERN GULF WILL KEEP UP THE STRONG NORTHERLY SURFACE FLOW OVER THE REGION. ALL IN ALL...CURRENT ZFP LOOKS ON TARGET WITH NO CHANGES NEEDED. MARINE...BUOY020 MAINTAINS SWELLS OF 11 FEET WITH A N WIND OF 25 KTS WITH GUSTS TO 31. SURFACE LOW OVER THE WESTERN GULF INDICATED BY RUC AND MESO-ETA PERSISTS OFFSHORE TODAY WHICH WILL ENHANCE THE PGF OVER THE BAY AND GULF WATERS. ACCORDINGLY...THE STRONG SURFACE FLOW WILL CONTINUE TODAY AND WILL MAINTAIN SCA CONDITIONS. NO CHANGES REQUIRED TO THE CURRENT CWF. SYNOPTIC...60/MESO...CAMPBELL INTERNET ADDRESS...WWW.SRH.NOAA.GOV/BRO .BRO...SCA TODAY FOR GMZ130-150-155-170-175. tx SOUTHEAST TEXAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX 945 AM CST MON JAN 1 2001 CLOUD COVER UNDERNEATH INVERSION WILL BE QUITE SLOW TO BREAK UP ESPECIALLY SOUTHERN ZONES. RUC PROGGED SOUNDING INDICATE BREAKUP AROUND MID DAY. MESO-ETA MORE SLOW ON THIS SCENARIO BREAKING UP CLOUDS NORTHERN ZONES THIS AFTERNOON AS DRIER 1000-850 MB MEAN RH VALUES FILTER IN SLOWLY FROM N AND NE. WILL MAKE ADJUSTMENTS TO CLOUD COVER 1ST PERIOD. OTHERWISE... THE REST OF PREVIOUS FORECAST PACKAGE ON TRACK. .KHGX...SCA COASTAL WATERS 0-60 NM... SCEC ON BAYS. 37/36/TF CLL BB 045/026 049/024 053 000 IAH EB 045/028 049/025 053 000 GLS EB 044/037 048/034 050 -00 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG, VA 1017 AM EST MON JAN 1 2001 WV LOOP SHOWS SHRWTV IN CNTRL TN. 09Z RUC HAD BEST DYNAMICS AND DEEPER MOISTURE MOVING INTO THE SWRN CWA BY 18Z. WL UPDATE BY 11 TO ADJUST MORNING WORDING. DON'T PLAN ON ANY BIG CHANGES. .RNK... NC...NONE. VA...NONE. WV...NONE. AMS va AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 230 PM CST MON JAN 1 2001 NARROW BAND OF LIGHT SNOW/FLURRIES SPANNING THE CWA TODAY...NOW FROM NEAR GALESBURG TO IOWA CITY TO MARSHALLTOWN. THIS BAND IS PART OF THE CLOUD SHIELD AROUND THE UPPER LOW DROPPING INTO NORTHEAST MISSOURI THIS AFTERNOON. AS THIS LOW DROPS SOUTH TONIGHT...EXPECT THE CLOUDS TO CONTINUE TO CLEAR VERY SLOWLY. RUC ALSO SUPPORTS A CLEARING TREND WITH DRYING IN THE LOW LEVELS. COLD POCKET STILL TO THE WEST AND SOUTH...SO MINS TONIGHT WILL BE COLDER SOUTH AND WARMER NORTHEASTERN ZONES. TOMORROW PROMISES TO BE SUNNY WITH TEMPS IN THE 20S AS THE SURFACE RIDGE SLIDES SOUTH OF THE REGION. IN CLOUDY AREAS...MAV HAS BEEN CLOSER...BUT IN THE SUNNY SPOTS FWC IS A BETTER BET. WITH SUNSHINE EXPECTED FOR MOST OF THE AREA TOMORROW...WILL OPT TO GO CLOSER TO WARMER FWC NUMBERS. NEXT QUESTION IS THE CHANCE FOR PRECIP TUESDAY NIGHT. MODELS ALL BRING A SHORT WAVE ACROSS IOWA TUESDAY NIGHT. AVN IS THE STRONGEST...NGM THE WEAKEST...AND ETA IN BETWEEN. REGARDLESS OF DIFFERENCES IN STRENGTH...THERE WILL BE LITTLE MOISTURE AVAILABLE FOR PRECIP. WILL LOWER POPS SOUTH FOR TUESDAY NIGHT AND WEST FOR WEDNESDAY. GOOD NEWS IS THAT TRAJECTORIES WILL BRING AN INTRUSION OF PACIFIC AIR INTO THE MIDWEST...WARMING TEMPERATURES INTO THE END OF THE WEEK. BAD NEWS IS THAT WARMER TEMPERATURES WILL BEING HIGHER DEW POINTS...AND WITH THE SNOW COVER...COULD TURN INTO FOG AND/OR STRATUS WHICH WILL CUT TEMPERATURES. SO DO NOT BELIEVE WE WILL SEE 44 FRIDAY AS ADVERTISED BY THE FMR NUMBERS. WILL CONTINUE WITH NEAR FREEZING TEMPS POSSIBLE...BUT THAT IS LIKELY THE BEST WE COULD HOPE FOR. NEXT COOL DOWN ON TAP FOR SUNDAY. MOST OF THE EXTENDED LOOKS OK...BUT WILL ADD A LOW POP FOR THE SOUTH FOR SUNDAY. .DVN... IA...NONE. IL...NONE. MO...NONE. 33 il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 345 PM EST MON JAN 1 2001 FCST FOCUS SHIFTS FROM LES TO CLOUDS/TEMPS AND -SN CHANCE TUE NIGHT. WV IMAGERY/RUC ANAL SHOW UPR TROF EXTENDING FROM EASTERN GREAT LAKES TO MID-MISS VALLEY WITH A RIDGE AXIS FROM N HIGH PLAINS TO JAMES BAY. IMAGERY SHOWS SHORTWAVES OVER N MANITOBA AND ANOTHER MOVING INTO W ALBERTA. 18Z SFC ANAL SHOWS 1038MB HIGH OVER S MN/N IOWA. BACKING WINDS ACROSS UPR MI/LAKE SUPERIOR FINALLY PUTTING AN END TO LES WITH LINGERING BANDS DISORGANIZING EARLY THIS AFTERNOON BASED ON KMQT 88D/VIS SAT IMAGERY. MODELS INTIALIZED UPSTREAM SHORTWAVES WELL AND AGREE IN BRINGING ALBERTA SHORTWAVE TO UPR MI TUE NIGHT WHILE WESTERN LONG WAVE RIDGE AMPLIFIES AND SHIFTS EASTWARD. TONIGHT...SHORTWAVE RIDGE MOVES OVERHEAD. 1038MB SFC HIGH MOVES TO MISSOURI WITH TIGHTENING GRAD OVER UPR MI INCREASING SW WINDS. SW WINDS WILL END ANY LINGERING -SHSN OVER KEWEENAW WHEN H85 WAA ENDS LOW LEVEL INSTABILITY. MIN TEMPS TRICKY AS WINDS SHOULD DECOUPLE EARLY BEFORE PRES GRAD TIGHTENS. WILL NUDGE TEMPS DOWN WEST ALONG WI BORDER SLIGHTLY BELOW GUIDANCE ASSUMING EARLY DROP OFF BEFORE WINDS PICK BACK UP. TUESDAY...RIDGE BEGINS MOVING SE OF UPR MI WHILE SHORTWAVE DIGS INTO THE DAKOTAS BY 18Z. MOISTURE RATHER LIMITED AHEAD OF THIS WAVE AND ONLY BEGINS MOVING INTO EXTREME WESTERN COUNTIES BETWEEN 21Z AND 00Z. WILL PROBABLY AT LEAST SEE INCREASING HIGH CLOUDS WITH WAA PATTERN AND INCREASING H7-H3 QVEC CONV OVER W. GUIDANCE TEMPS LOOK GOOD. TUESDAY NIGHT...SHORTWAVE SWINGS SOUTH OF UPR MI OVERNIGHT WITH WEAK-MOD H7-H3 QVEC CONV AND DEEPER MOISTURE (H10-H5 RH >75%) MOVING W-E ACROSS CWA. MODELS SPIT OUT A COUPLE HUNDREDTHS OF AN INCH OF PRECIP...WHICH SEEMS REASONABLE. ISENTROPIC SFCS SHOW NEUTRAL TO DOWNSLOPE FLOW... ALTHOUGH WEAK H3-H2 DIV ASSOCIATED WITH LEFT EXIT REGION OF 130KT H3 JET FROM CNTL CANADA TO UPR MISS VALLEY SHOULD ENHANCE UPWARD MOTION. H85 TEMPS DIFFER BETWEEN AVN (-12C EAST) AND ETA (-9C) AS WINDS VEER NW LATE. THIS SHOULD NOT BE A FORECAST PROBLEM THIS PERIOD AS SYNOPTIC LIFT EXITS ALL BUT FAR E UPR MI PRIOR TO ONSHORE COMPONENT DEVELOPING (I.E. NO ENHANCEMENT/LES). BOTTOM LINE...GIVEN SOME OF THE NEGATIVE LISTED ABOVE...WILL MAINTAIN HIGH CHANCE POPS. WEDNESDAY...SFC RIDGE BEGINS BUILDING IN FROM THE WEST...WITH BACKING ANTICYLCONIC WINDS OVER LAKE SUPERIOR. H85 TEMP DIFFS CONTINUE AS ETA CARRIES SLIGHTLY SHARPER RIDGE OVER UPR MI RESULTING IN LOWER INVERSION HEIGHTS THAN AVN. ETA FORECAST SOUNDINGS SHOW NEAR-SATURATED LAYER FROM SFC-900MB...SO WILL CONTINUE MOSTLY CLOUDY SKIES. WILL ALSO CONTINUE LOW POPS FOR EASTERN LAKE SHORE COUNTIES WHERE LIMITED AND SHALLOW INSTABILITY MAY STILL BE ENOUGH TO MAINTAIN SCT -SHSN THROUGH THE DAY WITH LONGER FETCH. EXTENDED...ALL MODELS IN GENERAL AGREEMENT WITH LARGE SCALE FEATURES. MRF CONTINUES TO SHOW GOOD CONTINUITY. 12Z AVN EXTENSION ALSO SUPPORTS 00Z MRF SOLUTION. MRF ENSEMBLES ALSO SHOW RELATIVELY LITTLE SPREAD THROUGH EXTENDED PERIOD. THEREFORE...FOLLOWED 12Z AVN EXTENSION/MRF OUTPUT. TWEAKED THU/FRI PERIOD BY WORDING FOR BREEZY CONDITIONS THU AS TIGHT PRES GRAD SETS UP OVER UPR MI WITH 982MB LOW OVER N MANITOBA AND PUSHED BACK SNOW CHANCE TIL LATE. OTHERWISE...NO BIG CHANGES FOR REMAINDER OF PERIOD WITH SLIGHTLY COOLER AIR WORKING IN ON FRI (H85 ~ -10C). 12Z AVN A LITTLE WARMER THAN MRF WITH COLDEST AIR FARTHER EAST. WILL NUDGE SAT/SUN TEMPS UP SLIGHTLY. .MQT...NONE. JS mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTH PLATTE NE 251 PM CST MON JAN 1 2001 ...LOW CLOUDS/FLURRIES TONIGHT AND TEMPS WILL BE THE CHALLENGE... UPPER PATTERN FEATURES A LARGE TROF OVER THE EASTERN U.S. WITH A BROAD FLAT RIDGE OVER THE WESTERN STATES. ONE WAVE IN THE FLOW IS SPINNING SOUTHWARD THROUGH IA/MO AND ANOTHER WEAK WAVE IS DROPPING ALONG THE DIVIDE THROUGH WY/CO. AT THE SURFACE...HIGH PRESSURE IS CENTERED OVER EASTERN SD/NE WEDGING SOUTHWARD INTO KS/OK. HIGH PRESSURE ALSO EXISTS ALONG THE DIVIDE FROM ID TO NM. NO MAJOR DIFFERENCES AMONG THE MODELS. RUC AND HI RES ETA HAVE RESOLVED POSITION OF LOW CLOUDS OVER WESTERN NEBRASKA FAIRLY WELL. EVEN THOUGH CLOUDS HAVE MIXED OUT AT LBF LOW CLOUDS PERSIST AT OGA/IML/MCK/SNY. VIS/3.9 SAT PICS ALSO REVEAL RAPID NORTHWARD ADVECTION OF CLOUD DECK INTO GARDEN/ARTHUR/GRANT COUNTIES. HI RES ETA...AND TO SOME EXTENT THE RUC...SOLUTIONS ADVECT THE MOISTURE RAPIDLY NORTH/NORTHEAST AHEAD OF ADVANCING SURFACE TROF. WITH CLOUDS LOOMING TO THE WEST AND SOUTHWEST AND HAZY CONDITIONS AT LBF INDICATING MOISTURE STILL REMAINS TRAPPED BELOW 950 MB...EXPECT CLOUDS TO SPREAD RAPIDLY NORTHEASTWARD ACROSS MUCH OF THE CWA TONIGHT. CLOUDS WILL REMAIN IN -10 TO -15 C TEMP RANGE WHICH WILL CONTINUE TO BE FAVORABLE FOR PERIODS OF FLURRIES. SURFACE TROF SHOULD EXTEND FROM NEAR ONL TO NEAR MCK BY MORNING AND WILL SCOUR OUT THE LOW LEVEL MOISTURE AS IT SHIFTS EASTWARD...WILL WORD MANY ZONES WITH DECREASING CLOUDS LATE. CLOUDS ARE LIKELY TO HOLD TEMPS UP AND WILL GO SLIGHTLY ABOVE GUIDANCE. WITH SURFACE TROF SHIFTING EAST OF THE CWA BY 18Z TUESDAY AND LARGE SCALE SUBSIDENCE INCREASING ALL AREAS ARE EXPECTED TO CLEAR OUT BY AFTERNOON. DOWNSLOPING FLOW COMBINED WITH LOW LEVEL WAA WILL RESULT IN MUCH WARMER TEMPS AS PER GUIDANCE. TIGHTENING LOW LEVEL GRADIENTS FARTHER NORTH WILL RESULT IN STRONGER WINDS...WHICH WILL AID IN SCOURING OUT ANY RESIDUAL MOISTURE EARLY IN THE DAY. UPPER RIDGE EXPECTED TO AMPLIFY OVER THE WESTERN U.S. TUESDAY NIGHT AND EXTEND INTO THE PLAINS AFTER WEAK TROF EXITS NEBRASKA BY 06Z WED. LARGE SCALE SUBSIDENCE TO CONTINUE AND LOW LEVEL WESTERLY DOWNSLOPE FLOW WILL MAINTAIN MILD CONDITIONS. GUIDANCE MINS APPEAR REASONABLE. NO CHANGE INTO WEDNESDAY OTHER THAN INCREASING HIGH CLOUDINESS CRESTING THE RIDGE. WAA CONTINUES ALONG WITH DOWNSLOPING LOW LEVEL FLOW. NO REASON TO STRAY FROM GUIDANCE MAXES. RIDGE EXPECTED TO SHIFT EVEN FARTHER EAST INTO THE PLAINS BY 12Z THURSDAY. HIGH CLOUDS ARE LIKELY TO SHIFT EAST OF THE AREA AS WELL...CONTINUED MILD. IN THE EXTENDED...NO MAJOR CHANGES THROUGH FRIDAY. THURSDAY LIKELY TO BE THE WARMEST DAY WITH POTENTIAL FOR A 60 DEGREE TEMP FAR SOUTHWEST. UPPER FLOW EXPECTED TO VEER AROUND TO THE NORTHWEST AGAIN BY FRIDAY IN WAKE OF A PASSING WAVE WHICH RESULT IN COOLER TEMPS BUT SHOULD STILL REMAIN ABOVE NORMS FOR JANUARY. .LBF...NONE DJB ne AREA FORECAST DISCUSSION...UPDATE NATIONAL WEATHER SERVICE BLACKSBURG, VA 1210 PM EST MON JAN 1 2001 LATEST MESO-ETA AND 16Z RUC PULL BACK ON THE QPF FOR TDY PLUS CLDS ARE DISSIPATING AS THEY ARE CROSSING INTO THE PIEDMONT. SO NEW UPDATE WL CUT WAY BACK ON THE POPS IN ALL BT SE WV AND THE FAR SW COUNTIES OF THE CWA. .RNK... NC...NONE. VA...NONE. WV...NONE. AMS va