AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SACRAMENTO CA 425 AM PST SAT JAN 19 2002 FOG PRODUCT SHOWING THIN STRIPS OF NORTH-SOUTH ORIENTED FOG DEVELOPING IN THE INTERIOR VALLEY OF NORCAL THIS MORNING. OBS SHOWING SOME DENSE STUFF IN SOUTHERN PORTIONS OF ZONE 19 BUT NOT WIDESPREAD ENOUGH AT THIS TIME TO ISSUE AND DFA. WILL MONITOR CLOSELY AS VISIBILITY RESTRICTIONS COMBINED WITH FREEZING TEMPS COULD MAKE FOR DIFFICULT DRIVING. NEXT CONCERN IS VORT MAX BEGINNING TO SLIDE INTO NORTHERN PORTION OF CALIFORNIA. SAT IMAGERY SHOWING A RELATIVELY STRONG DISTURBANCE BUT WITH LIMITED MOISTURE. LATEST RUC/AVN/ETA GENERATE LIMIT QPF OVER NORTHERN MOUNTAINS OF CWA THIS MORNING AS ASSOCIATED DPVA MOVES THROUGH. WITH DRY AMS ALREADY IN PLACE...EXPECTING LITTLE PRECIP. STRONG SUBSIDENCE IN WAKE OF DISTURBANCE WILL MAKE FOR WINDY CONDITIONS AT THE HIGHER MOUNTAIN ELEVATIONS TODAY. OVERRUNNING WF PRECIP APPROACHING 130W WILL BEGIN TO FACTOR INTO SUNDAYS WEATHER IN NORTHERN PORTION OF CWA. LOWER LEVEL WAA IN NORTHERN PORTIONS OF CWA WILL MODIFY AMS SOMEWHAT. LATEST 06Z AVN CONSISTENT WITH PREVIOUS RUN AND PUSHES ASSOCIATED CF INTO THE CWA MONDAY AS UPPER TROUGH DIGS. SIGNIFICANTLY COLDER AIR BEHIND FRONT WILL DROP SNOW LEVELS OVERNIGHT MONDAY INTO THE FOOTHILLS. SECOND UPPER VORT TUESDAY MORNING BRINGS ANOTHER REINFORCING SHOT OF COLD AIR INTO STATE WITH LOW SNOW LEVELS CONTINUING. AMS BEGINS TO STABILIZE BEHIND SECOND VORT ON TUESDAY FOR DECREASING SHOWERS. EXTENDED MODELS DIFFER ON POSITION OF E PAC UPPER RIDGE. ECMWF/NOGAPS SIMILAR WHILE GEM MORE INLINE WITH MRF. WITH DIGGING 5H LOW OF 503 DM ...-40C AT 5H...IN BERING SEA 12Z WED BELIEVE HIGHER AMPLITUDE DOWNSTREAM RIDGE SOLUTION AND FEEL MRF OVERDONE ON OVERRUNNING PRECIP IN NORCAL WEDNESDAY. ATTM WILL KEEP CURRENT FORECAST DAY 5 FOR COORDINATION. RIDGE MOVES THROUGH NORCAL DAYS 6 INTO 7 AS AFOREMENTIONED COLD DEEP TROUGH MOVES INSIDE 140W NEXT SATURDAY. .STO...NONE. BLU BE 039/028 043/033 040 74000 RBL BE 055/031 053/037 051 74002 SAC BB 054/030 054/036 052 74000 PCH ca AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSONVILLE FL 700 PM EST SAT JAN 19 2002 CURRENTLY...LOOKS LIKE THE COLD FRONT HAS GONE THROUGH MACON AND ALBANY AND IS POISED TO MOVE THROUGH TALLAHASSEE IN THE VERY NEAR FUTURE. A NARROW LINE OF SHOWERS AND THUNDERSTORMS IS MOVING TOWARD THE FORECAST AREA (FA) WITH THE LEADING EDGE MOVING INTO COFFEE AND JEFF DAVIS COUNTIES (IN THE EXTREME NE PORTION OF THE FA). OBSERVATIONS IN LOCATIONS WHERE THE LINE HAS PASSED INDICATE WIND GUSTS OF 32-38 KNOTS. BASED ON PERSISTENCE...IT LOOKS LIKE GUSTS SHOULD TOP OUT AT 40 MPH OR SO. MOODY VAD WIND PROFILE INDICATING 55 KNOT WINDS 3 KFT OFF THE DECK SO LOW LEVEL WIND SHEAR IS DEFINITELY THERE. LOCAL LOW LEVEL INSTABILITY IS NOT IMPRESSIVE AND IF THE RUC IS TO BE BELIEVED THE LOW LEVELS WILL FURTHER STABILIZE OVER THE NEXT FEW HOURS. IT DOES APPEAR THAT THE NORTHERN PORTIONS OF THE LINE ARE BECOMING MORE RAGGED AS IT APPROACHES THE FA. OVERALL...IT LOOKS LIKE A FEW STRONG THUNDERSTORMS ARE POSSIBLE BUT NOT LOOKING LIKE THERE'S MUCH OF A SEVERE THREAT. OF COURSE WILL MONITOR THE LINE CLOSELY FOR ANY SURPRISES AND BOTH MOODY/JACKSONVILLE RADARS ARE IN VCP 11/SQUALL LINE TVS MODE. MARINE...NO MAJOR CHANGES ANTICIPATED. .JAX... .GA...SMALL CRAFT ADVISORY ALTAMAHA SOUND TO FERNANDINA BEACH. .FL...SMALL CRAFT ADVISORY FERNANDINA BEACH TO FLAGLER BEACH. SANDRIK fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1005 PM EST FRI JAN 18 2002 COLD FRONT HAS COME ROARING THROUGH KCMX AROUND 730 PM WITH WIND GUSTS AFTER THAT TIME ALMOST TO 40 MPH. SFC COLD FRONT HAS NOT BEEN BEEN THROUGH KIMT OR KSAW YET OR EVEN AT THE NWS OFFICE. COLD FRONT HAS PASSED THROUGH KP59 QUICK BURST OF SNOW THAT WAS IN THE FORECAST BEFORE THE FRONT HAS OCCURRED WITH VISIBILITIES DOWN TO 1 MILES IN A FEW PLACES AND LOOKING AT KMQT RADAR...SMOOTH APPEARANCE OF ECHOES HAS DISAPPEARED AND IS BEING REPLACED BY CELLULAR LOOKING ECHOES. THE ECHOES ARE ALSO GROWING STRONGER WITH A FEW ECHO RETURNS GREATER THAN 28 DBZ RIGHT ALONG HIGHWAYS 41/28 AROUND 900 PM. LUCKILY...THESE ECHOES ARE NOT REMAINING IN ONE PLACE...BUT MOVING RAPIDLY EAST. LOOKS LIKE LAKE EFFECT HAS STARTED OVER THE WESTERN CWA...BUT HAS NOT ORGANIZED INTO BANDS AS YET. OVER THE EAST...WINDS ARE STILL FROM THE SW. PROBLEMS AT NCEP WITH GATEWAY CONTINUE AND THIS IS AFFECTING MODEL RUNS WITH MODEL RUNS GETTING OFF TO A LATE START. ONLY NEW MODEL STUFF TO LOOK AT IS RUC AND THIS SEEMS TO CONFIRM EARLIER FORECAST. BASICALLY...GOING FORECAST HAS THINGS WELL IN HAND EXCEPT COLD FRONT IS SLOWER MOVING THROUGH CWA AND WILL BUMP WINDS UP IN ZONES TO ACCOUNT FOR THIS. WILL ALSO REMOVE EVENING WORDING. ZONE UPDATE WILL BE OUT SHORTLY. .MQT...GALE WARNING EAST HALF OF LAKE SUPERIOR. MICHELS mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 410 PM EST FRI JAN 18 2002 MAIN FCST CONCERNS ARE SNOW CHANCES/AMOUNTS OVER THE NEXT FEW DAYS. WV IMAGERY AND RUC ANALYSIS INDICATED BROAD BUT SHALLOW TROF INTO THE NORTH CNTRL CONUS AS POLAR VORTEX LINGERED OVER HUDSON BAY RESULTING IN WNW MID LVL FLOW INTO THE WRN GRT LAKES. AN UPSTREAM SHRTWV FROM SRN MANITOBA INTO NE MN AND ASSOCIATED DPVA SUPPORTED AN AREA OF -SHSN FROM NE MN AND SW ONTARIO TOWARD WRN LK SUPERIOR AND WRN UPR MI. SNOWFALL WAS GENERALLY LIGHT SO FAR WITH 3-5SM -SHSN. AT THE SFC...LO PRES WAS LOCATED JUST NE OF KINL WITH A COLD FRONT EXTENDING SE INTO NORTH CNTRL MN. MDLS WERE IN REASONABLE AGREEMENT INTO MONDAY WITH PLACEMENT AND STRENGTH OF SFC AND MID LVL FEATURES AFFECTING UPR MI AS WELL AS WEAK QPF PATTERNS. ETA WAS COLDER THAN AVN WITH LLVL AIR AND H8 TEMPS BY LATE TONIGHT AND LOOKS BETTER IN LIGHT OF STRONG LLVL CAA UPSTREAM. TONIGHT...AS QG FORCING WITH THE SHRTWV SLIDES BY EARLY THIS EVENING...PRIMARY FOCUS FOR PCPN WILL BE LLVL CONVERGENCE NEAR THE COLD FRONT. EXPECT BURST OF HEAVIER SNOW SHOWERS INTO NW UPR MI WITH THIS FEATURE BTWN 00Z-03Z. LES CONTRIBUTION WITH INCREASING INSTABILITY WITH LK-H8 DELTA/T TO NEAR 17C SHOULD BE ENOUGH TO BRING A QUICK 1-3 INCHES. WIND SHIFT TOWARD LESS FAVORABLE 320-330 ALONG WITH SUBSIDENCE AND FALLING INVERSION HGTS (TO NEAR 3K FT) WITH DNVA IN WAKE OF THE SHRTWV SHOULD KEEP ACCUMULATIONS OVERNIGHT TO A MINIMUM WITH MAINLY SCT -SHSN. SIMILAR BAND OF HEAVIER SNOW ARRIVES LATER FOR AREAS EAST OF MARQUETTE WITH INHIBITING FACTORS MENTIONED ABV TAKING OVER AFT 06Z. DELTA/T TO AROUND 20C COMBINED WITH LONGER FETCH WL KEEP SLIGHTLY HEAVIER SHSN GOING OVERNIGHT THAN OVER THE WEST. CNTRL UPR SHOULD ALSO SEE PERIOD OF SHSN WITH SOME SMALL ACCUMULATIONS UNDER AN INCH(BEFORE WEAKER LES TAKES OVER EAST OF MARQUETTE). FARTHER SOUTH...BAND OF -SHSN SHOULD AMOUNT TO LITTLE MORE THAN A DUSTING. SUNDAY INTO SUNDAY NIGHT...FRONTAL BNDRY WILL SET UP TO THE SOUTH OF THE AREA. AS SHRTWV OVER BC THIS AFTERNOON MOVES THROUGH THE NRN PLAINS TOWARD THE UPR MS VALLEY SUNDAY...SFC LO PRES DEVELOPMENT WILL AID IN WAA AND ISENTROPIC LIFT INTO THE REGION. MDLS SUGGEST LATER ARRIVAL OF PCPN...MOVING IN FROM SW TO NE. LK MI ENHANCEMENT INTO SE UPR MI WILL BE MINIMIZED BY BRIEF PERIOD OF FAVORABLE WIND FLOW AND STRONGLY VEERING PRFL BTWN BNDRY LYR AND 850 MB. GENERAL WEAK SE FLOW MAY ADD ENOUGH LLVL MOISTURE TO BOOST SNOWFALL AMOUNTS BY AROUND AN INCH. MONDAY INTO MONDAY NIGHT...MDLS SHOW GAP IN PCPN DURING MOST OF MONDAY AS SHRTWV DEPARTS AND NEXT ONE ARRIVES MONDAY NIGHT. DUE TO TIMING UNCERTAINTY AND CONTINUED PRESENCE OF FRNTL BNDRY...WL KEEP IN CHANCE POPS THROUGH THE PERIOD. DAYS 3-7...MAIN FCST PROBLEM REVOLVES AROUND DEVELOPMENT OF WRN CONUS TROF. ECMWF/00ZUKMET/00ZCANADIAN WERE CONSISTENT WITH PREVIOUS RUNS IN KEEPING NRN/SRN STREAMS LESS PHASED AND WITH SLOWER PROGRESSION OF THE SRN PORTION OF THE TROF. THE OP MRF AND ENSEMBLE MEAN SUGGEST A MORE PHASED SOLN WITH POTENTIAL FOR SHRTWV MOVING OUT OF THE SRN CONUS HELPING TO SPIN UP STRONG LOW PRES SYSTEM INTO LOWER MI. THIS SCENARIO WOULD PRODUCE SUBSTANTIAL SNOW FOR UPR MI. THE 12Z AVN HAS TRENDED A BIT TOWARD THE FIRST GROUP AND EVEN SUGGESTS POSSIBILITY FOR -RA/-SN WED NIGHT WITH STRONGER LOW MOVING INTO UPR MI. THE 12Z UKMET IS VERY SIMILAR TO THE ECMWF BY WED/THURS. SO...PREFER LESS PHASED SOLN WITH A WEAKER ELONGATED INVERTED TROF TOWARD THE GRT LAKES BY 12Z THURS COMPARED TO THE STRONGER LO OVER ERN LK SUPERIOR FCST BY THE AVN. REGARDLESS OF MDL CHOICE...DECENT CHANCE REMAINS FOR SOME SNOW ON WED WITH SUPPORT FROM DEVELOPING JET RIGHT ENTRANCE FRONTAL BNDRY...WAA AND INCREASED GULF MOISTURE INFLOW TOWARD THE WRN GRT LAKES. ECMWF/CANADIAN/UKMET SOLNS DO NOT TAP ENOUGH COLD AIR FOR MUCH OF A LES THREAT. SO...WITH PLENTY OF UNCERTAINTY...WL ONLY MENTION CHANCE POPS FOR SNOW THURSDAY. BY FRIDAY...ENOUGH COLD AIR SHOULD FILTER IN AS THE TROF PROGRESSES TO THE EAST FOR SOME SHSN OVER NRN UPR MI OR WITH WEAK CLIPPER SUGGESTED BY MRF. MDLS SUGGEST WAA DEVELOPING SATURDAY POTENTIAL FOR SOME -SN OR FLURRIES. HAVE KEPT TEMPS AOA MRF GUIDANCE...GIVEN ITS FREQUENT COLD BIAS BY DAYS 5-7. .MQT...GALE WARNING LK SUPERIOR. JLB mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1120 AM EST SAT JAN 19 2002 THE LATEST APX 88D DATA AND SURFACE OBSERVATIONS...SHOW LAKE INDUCED SNOW SHOWERS DEVELOPING OVER NORTHWEST LOWER AND EAST UPPER MICHIGAN. SURFACE OBSERVATIONS SHOW VISIBILITIES REDUCED TO AROUND 1 AND 2 MILES IN SNOW OVER THE WESTERN STRAITS...PETOSKEY AND PELLSTON. THE LATEST SURFACE CHART SHOWS A LOW PRESSURE SYSTEM OVER MINNESOTA...MOVING EAST TOWARD THE STRAITS. THE LATEST RUC DATA SHOWS THIS SURFACE FEATURES MOVING INTO CENTRAL UPPER MICHIGAN BY THIS EVENING. AT UPPER LEVELS...A BROAD UPPER TROUGH AND VORT MAX WILL MOVE OVER THE UPPER MIDWEST AND INTO THE WESTERN LAKES THIS AFTERNOON/EVENING. ADDITIONAL SUPPORT FOR SNOW WILL BE DUE TO OVER LAKE INSTABILITY. 850 MB TEMPERATURES ARE PROGGED TO BE AROUND -12C THIS AFTERNOON...WITH 1000/850 MB WINDS FROM THE SOUTHWEST AT 20 TO 25 KNOTS. 900/700 MB MOISTURE WILL BE BETWEEN 70 AND 90 PERCENT WITH FORECAST INVERSION HEIGHTS INCREASING TO AROUND 9000 FEET THIS AFTERNOON. THEREFORE WILL LEAVE THE ADVISORY FOR EAST UPPER AND THE WESTERN STRAITS...WITH DIMINISHING CHANCES OF SNOW EAST OF I-75. APX...WINTER WEATHER ADVISORY... SWR mi SOUTHEAST MICHIGAN AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 1029 AM EST SAT JAN 19 2002 UPPER LEVEL TROUGH AXIS EXTENDS FROM CENTRAL IOWA TO CENTRAL OKLAHOMA. ALTHOUGH BEST UPPER SUPPORT IS WELL SOUTHEAST OF THE GREAT LAKES...SURFACE OBS ACROSS CENTRAL ILL AND IND HAVE BEEN INDICATING SCATTERED FLURRIES AHEAD OF THE TROUGH. ALTHOUGH THE 12Z MESO ETA AND RUC SHOW SOME MODEST LIFT ALONG THE OHIO/MICHIGAN BORDER THROUGH 18Z...EXTREMELY DRY AIR IN THE 900-850 MB LAYER (PER 12Z KDTX SOUNDING AND 12Z MESO ETA SOUNDINGS) SHOULD PREVENT ANYTHING FROM REACHING THE GROUND. SOME 280K ISENTROPIC ASCENT OVER WISCONSIN IS CONTRIBUTING TO AREAS OF LIGHT SNOW/FLURRIES ATTM. THE 12Z MESO ETA BRINGS THIS AREA OF ASCENT OVER NORTHERN AND CENTRAL LOWER MICHIGAN BETWEEN 18 AND 21Z. WITH THE SHORT WAVE CURRENTLY OVER SOUTHERN MANITOBA PROGGED TO MOVE INTO NORTHERN WI/WESTERN UPPER MI BY 21Z AND WITH STILL SOME SHALLOW LAKE INSTABILITY UNDER SW FLOW...I WILL RETAIN A CHANCE OF FLURRIES ACROSS THE TRI CITIES. I WILL LEAVE THE REST OF THE FORECAST AREA DRY GIVEN THE WEAK FORCING AND DRY 900-850MB LAYER. PLENTY OF MID/UPPER LEVEL CLOUDS UPSTREAM TO KEEP SKIES MOSTLY CLOUDY. CURRENT MAX TEMP FORECAST LOOKS ON TARGET. .DTX...GALE WARNING...THIS AFTERNOON/EVENING...NORTH 2/3 LAKE HURON. CONSIDINE mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 630 AM EST SAT JAN 19 2002 MAIN CONCERNS ARE SNOW CHCS THRU FCST PKG. WV LOOP/RUC ANALYSIS SHOWS WK SHRTWV MOVG ACROSS LAKE SUPERIOR WITH MORE SUBSTANTIAL SHRTWV MOVG DOWN FM SRN MANITOBA AND WRN ONTARIO. WKR INITIAL SHRTWV ASSOC WITH SFC-850 MB WMFNT EXTENDING THRU MN FM LOW OVR SRN MANITOBA/WRN ONTARIO. WAA/ISENTROPIC LIFT AHD OF LOW/WMFNT PRODUCING SCT LGT -SHSN OR FLURRIES OVR NW WI AND ERN MN ATTM PER 88D LOOP. TODAY...AS ISENTROPIC LIFT AHD OF SFC LOW WORKS EWD INTO U.P. LATER THIS MORNING...EXPECT SCT LGT -SHSN AND FLURRIES TO SPREAD ACROSS FA. AS MORE POTENT SHRTWV AND ASSOC DEEPENING SFC LOW OVR SRN MANITOBA DIVES SOUTH LATER THIS AFTERNOON...MODELS SHOW STG CDFNT TO MOVE ACROSS WRN U.P. TODAY AND ERN U.P. THIS EVNG. HAVE USED ETA FOR FCST DETAILS AS IT HAS BEEN DOING A BETTER JOB THAN AVN HANDLING DEEPER SFC LOW AND ADVANCE OF -19 TO -20C 850 MB COLD AIR ASSOC WITH SYSTEM. ETA FCST SNDGS SHOW INVERSION HGTS DISAPPEARING BRIEFLY LATE THIS AFT AND EVNG OVR NW ZONES WITH ENHANCEMENT FM SHRTWV AND MIXING WITH CDFNT. DUE TO BREVITY OF ENHANCEMENT AND VEERING OF WINDS HAVE ONLY INCLUDED 1-2 INCHES OVR CMX-KEW WITH AN INCH OVR ONT COUNTY. BUMPED UP TEMPS MORE IN LINE WITH MOS GUIDANCE (20 TO 25) AND UPSTREAM SFC TRAJECTORIES FM YESTERDAY. TONIGHT...SHRTWV AND ASSOC CDFNT CONTINUE ACROSS ERN LAKE SUPERIOR AND ERN FA IN EVNG. VEERING FLOW TO NNW BEHIND CDFNT...WOULD EXPECT ANOTHER 1-2 INCHES OVR CMX-KEW WITH 1-3" OVR ONT COUNTY WHERE BETTER 950 MB CONV NOTED OVR UPSLOPE TERRAIN. VEERING FLOW OCCURS LATER OVR ERN HALF ZONES WHERE BEST CONV NOTED FM 03Z ALG CDFNT TO 06Z IN CAA IMMEDIATELY BEHIND FNT. SINCE WINDOW OF BEST 950 MB CONV AND ENHANCEMENT SHORTER OVR EAST ZONES ONLY INCLUDED 1-3 INCHES AMTS FOR ALGER-LUCE DESPITE GREATER FETCH ACROSS LAKE. ALSO INCLUDED 1-2" FOR ERN MQT AND NRN SCHOOLCRAFT AS WELL IN 330-340 FLOW BEHIND FRONT. BY 06-09Z INV HGTS CRASH QUICKLY TO 3KFT OR LOWER IN COLDER AND MUCH DRIER AIR BEHIND FNT AS FLOW SHARPLY WKNS AND BCMS MORE ANTICYCLONIC SO EXPECT LES TO TAPER OFF TO FLURRIES BY THIS TIME. WENT ABV GUIDANCE TEMPS GIVEN ONSHORE NLY FLOW AND EXPECTED CLD CVR. SUNDAY AND SUNDAY NIGHT...06Z ETA AND AVN IN BETTER AGREEMENT IN HANDLING OF NORTHERN PAC SYSTEM HEADING INTO THE NRN PLAINS. SHRTWV TROF TAKING ON MORE NEG TILT ALLOWING FOR BETTER WAA/ISENTROPIC LIFT OUT AHD OF IT...ESPECIALLY OVR CNTRL AND ERN ZONES BY SUNDAY AFT AND EVNG. HAVE ACCORDINGLY BUMPED UP POPS TO LIKELY OVR CNTRL AND ERN ZONES WITH EVEN CAT POPS OVR SCHOOLCRAFT COUNTY FOR GOOD POSSIBILITY OF ENHANCEMENT OFF LAKE MICHIGAN. INCRG 850-500 MB Q-VECT CONV AND 2-D FRONTOGENESIS IN AFT OVR ERN ZONES SHOULD HELP ENHANCE SNOW GIVEN EXPECTED DELTA-T'S 15-16C AND 140-160 CBL FLOW. ETA CONFIRMS THIS BY SHOWING GOOD 950 MB CONV OVR DELTA-MNM COUNTIES 21-00Z WITH EVEN BETTER CONV OVR SCHOOLCRAFT 21Z-04Z. HAVE WENT WITH AMTS OF 1-2 INCHES OVR DELTA-MNM AND 1-3 INCHES OVR SCHOOLCRAFT FOR SUNDAY. SYSTEM SNOW OVR MQT-BARAGA AND DICKINSON-IRON SHOULD BE AROUND AN INCH AT BEST AS 2 G/KG MIXR ADVECTS IN FM SW DURING AFT PER ETA. EXPECT ADDITIONAL ACCUMS SUN EVNG OVR SCHOOLCRAFT COULD PUSH INTO ADV CRITERIA SNOW. FLOW VEERS MORE SW AFT 04Z WITH PASSAGE OF SFC-850 MB WMFNT SO WOULD EXPECT LAKE ENHANCEMENT TO SHUT OFF AT THAT TIME. MONDAY...KEPT IN GOING CHC POPS AS NEXT SHRTWV MOVES DOWN IN NW FLOW. LOOKS LIKE BETTER ISENTROPIC LIFT AHD OF SYSTEM WILL BE IN AFT AND MORE OVR NRN ZONES. COORD WITH APX...THANKS .MQT...GALE WARNING LAKE SUPERIOR. VOSS mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SPRINGFIELD MO 130 PM CST SAT JAN 19 2002 EARLY AFTERNOON TEMPERATURES HAVE MANAGED TO RISE TO AROUND 35 DEGREES WITH LOW CLOUDS AND SNOW COVER. MORNING CALLS AND SURROUNDING COOP REPORTS INDICATED NUMEROUS 3 TO 4 INCH SNOWFALL TOTALS ACROSS THE AREA...WITH THE HEAVIEST IN SOUTH CENTRAL MISSOURI WHERE LOCALLY 6 INCHES FELL AROUND WEST PLAINS...WILLOWS SPRINGS AND EMINENCE. FORECAST CONCERNS: TIMING OF LOW CLOUDS DEPARTING THIS EVENING...AND RETURN FLOW. LATER THIS WEEK RAIN/SNOW CHANCES. USING THE LATEST RUC 92H RH FIELDS (70% OR HIGHER)...CLOUDS SHOULD DEPART LATE AFTERNOON AND EARLY EVENING THROUGH MOST OF THE CWA. ALSO AS WINDS DECOUPLE THIS EVENING BEFORE RETURN FLOW DEVELOPS AFTER MIDNIGHT...BELIEVE LOWS WILL DROP SIGNIFICANT BEFORE STEADY OR SLIGHTLY RISE BY 3 AM OR SO. THEREFORE HAVE CUT TEMPERATURES BELOW GUIDANCE WITH MORNING LOWS AROUND MIDNIGHT. THE NEXT SHORT WAVE MOVING INTO THE PACIFIC NW WILL QUICKLY MOVE THROUGH THE AREA SUNDAY AFTERNOON. AS MOISTURE WILL BE LIMITED...ONLY EXPECT MID/HIGH CLOUDINESS TO AFFECT REGION. WILL NOT ADJUST TEMPERATURES FROM LAST NIGHTS READINGS AS THEY LOOK REASONABLE DUE TO WARMING THICKNESS VALUES (100/85H) AND RESIDUAL SNOWPACK. MONDAY AND TUESDAY LOOK SUNNY WITH ANY LEFT OVER SNOW COVER GONE BY MONDAY AFTERNOON. WILL ADJUST TEMPERATURES TO REFLECT DECREASING SNOW COVER AND ABUNDANT SUNSHINE. LATE TUESDAY/WED LOOKS TO BE WET AS LATEST HPC DISCUSSION AND RELATED MEDIUM RANGE MODEL ARE FORECASTING A SIGNIFICANT LONG WAVE TROUGH IN THE WESTERN/CENTRAL U.S. BY MIDWEEK WITH NICE GULF MOISTURE INFLUX. PRECIPITABLE WATER VALUES INCREASE TO ABOVE 1" BY WEDNESDAY WITH INCREASING DYNAMICS AND 85H JET...TO PROVIDE LOTS OF RAINFALL OVER THE AREA. THICKNESS VALUES BECOME FAVORABLE FOR SNOWFALL ON THE BACKSIDE OF THE SYSTEM...BUT MOST OF THE DEEP MOISTURE SHOULD BE GONE BY THAT TIME. THEREFORE...DON'T SEE ANY SIGNIFICANT SNOWFALL ATTM. ISC ALREADY SENT. FCSTID = 25/JLT SGF 16 44 27 50 / 10 10 10 10 JLN 20 47 29 54 / 10 10 10 10 UNO 16 42 28 49 / 10 10 10 10 VIH 16 42 28 49 / 10 10 10 10 .SGF... MO...NONE. KS...NONE. mo SOUTH CENTRAL AND SOUTHEAST COLORADO AREA FORECAST DISCUSSION. NATIONAL WEATHER SERVICE PUEBLO COLORADO 945 PM MST SAT JAN 19 2002 UPDATED THE ZONES TO INCLUDE NEW HIGH WIND WATCH FOR TONIGHT THROUGH SUNDAY MORNING FOR THE SOUTHERN MTNS AND ADJACENT PLAINS. REASON FOR THIS IS RUC/MESOETA NOW SHOWING 60-70 KNTS AT 500 OVER THIS REGION. SOME OF THESE WINDS WILL LIKELY REACH DOWN TO THE SFC OVER ABOVE MENTIONED REGION. AS FOR PIKES PEAK REGION...BEST THREAT FOR STRONG WINDS WILL BE TOMORROW AFTERNOON AND EVENING. .PUB...HIGH WIND WATCH LATE TONIGHT THROUGH NOON SUNDAY FOR TELLER COUNTY AND NORTHERN EL PASO COUNTY (ZONES 67/72). HIGH WIND WATCH S MTNS AND ADJACENT PLAINS...65...66...70 AND 74 AND 75. HODANISH co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PADUCAH KY 250 AM CST SUN JAN 20 2002 THE IMMEDIATE FORECAST CHALLENGE IS THE SNOW-INDUCED FOG POTENTIAL THIS MORNING ESPECIALLY IN THE SEMO AREA. 11-3.9 SATL STILL SHOWED SOME LOW CLOUDS OVER THE EASTERN PART OF THE FORECAST AREA WHICH WERE SLOWLY MOVING EASTWARD AND SHOULD ERODE AWAY FOR THE MOST PART BY SUNRISE. SOME THIN CIRRUS WAS SEEN MOVING IN FROM THE WEST WHICH COULD AFFECT RADIATIONAL COOLING SOME. THE CURRENT LOWS COULD STILL BE ACHIEVED IN THE EAST PROVIDING THE RUC'S HUMIDITY FIELDS ARE CORRECT. WILL CONSIDER DENSE FOG ADVISORY THIS MORNING FOR AT LEAST THE WESTERN PART OF THE FA CONSIDERING THAT MANY VISIBILITY READINGS WERE BELOW A MILE AND DROPPING. WILL CONTINUE TO MONITOR. SFC HIGH PRES AREA IS EXPECTED TO MOVE TO THE EAST TODAY ALLOWING A SOUTHERLY FETCH TO GET ESTABLISHED. FAST UPPER FLOW PATTERN WILL CONTINUE...WITH THE NEXT S/W ARRIVING EARLY MON. MODELS INDICATE THE DEEPER MOISTURE TO THE SOUTH AND NORTH AND LITTLE SFC REFLECTION IN THE FA. THE ONLY EFFECT SHOULD BE AN INCREASE IN CLOUD COVERAGE. FOR TUE...ANOTHER SFC HIGH PRES AREA WILL MOVE ACROSS THE SOUTHERN TIER OF COUNTIES...SIMILAR TO TODAY. THE GULF OPENS UP LATE TUE/EARLY WED IN ADVANCE OF A LARGE TROF. LATE WED...A SFC LOW DEVELOPING ALONG THE SFC BOUNDARY SHOULD ENHANCE LIFT ENOUGH FOR A BRIEF THUNDERSTORM PERIOD. DAY5 THRU DAY7 WILL BE DOMINATED BY RIDGING ALOFT AND THEREFORE TRANQUIL CONDITIONS. WILL CONTINUE UNDERCUTTING GUIDANCE BY A CAT FOR THE FIRST TWO PERIODS DUE TO SNOW COVER...THEN WILL GENERALLY FOLLOW AFTER THAT. NEW FMR TEMPS DO SEEM VERY WARM FOR MIDWEEK HOWEVER. .PAH...NONE. DB ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1030 AM EST SUN JAN 20 2002 ONLY FORECAST CONCERN FOR THE UPDATE IS SNOW CHANCES. 15Z SURFACE ANALYSIS SHOWS A WEAKENING SURFACE FRONT CAMPED OUT OVER THE NRN UPPER PENINSULA WITH ONLY LIGHT SHOW SHOWERS REPORTED NR THE FRONT AS RUC SHOWS WEAKENING 950MB CONVERGENCE AS THE MORNING GOES ON. SHORT WAVE OVER THE DAKOTAS WILL AFFECT THE AREA LATE THIS AFTN AND THIS EVENING CAUSING ANOTHER SHOT OF SNOW FOR THE UPR GREAT LAKES. AREA OF 280K ISENTROPIC LIFT CURRENTLY OVER EASTERN ND WILL MOVE TOWARD THE UPPER GREAT LAKES THIS AFTERNOON. LOW CONDENSATION PRES DEFICITS OF AROUND 10-20MB AT 280K PASS OVER THE AREA LATE THIS AFTN AND THIS EVENING...WHICH CORRESPOND WELL TO BEST LIFT. AS THE SHORT WAVE APPROACHES THE LAKES...A WEAK THETA-E RIDGE DEVELOPS AT 850MB WHICH HELPS TO STRENGTHEN ISENTROPIC LIFT AS SYSTEM MOVES THROUGH UPR MICHIGAN. THIS WOULD KEEP BEST SNOWS OVER CENTRAL/EASTERN UP OVERNIGHT TONIGHT...WITH THE WESTERN UP ONLY SEEING LIGHT SNOWS AS LIFT MUCH WEAKER AND MOISTURE NOT AS DEEP. WITH SLY WINDS...LAKE ENHANCEMENT ALSO POSSIBLE OFF LK MICHIGAN OVER THE EASTERN UP THIS EVENING...ALTHOUGH LK-850 DELTA-T VALUES ARE MARGINAL (AROUND 11C). WITH INCREASING LIFT/DEEPER MOISTURE AND STRONGER LOW LEVEL CONVERGENCE...SNOW COULD BE LOCALLY MODERATE FOR A SHORT PERIOD OF TIME OVERNIGHT OVER CENTRAL/EASTERN UP...HOWEVER STILL LOOKS LIKE ONLY AN INCH OR TWO ACCUMULATION BY MORNING. WILL UPDATE TO MAKE SOME MINOR COSMETIC CHANGES. OTHERWISE...TEMPS AND WEATHER LOOK GOOD. .MQT...NONE. MRD mi AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 1010 AM CST SUN JAN 20 2002 UPDATED TO MENTION RAISE TMPS SE CWA. SIGNIFICANT WEATHER CONTINES TO BE LACKING IN SHORT RANGE TODAY. MAIN BUT MINOR CONCERN FOR UPDATE WOULD BE WIND...CLOUDS AND TEMP. WK SFC TROUGH NOW ON THE EASTERN SIDE OF THE JAMES VLY...WHICH IS A SMIDGE AHEAD OF THE MESOETA/RUC POSITION. WKNG SFC WAVE ALG FRONTAL BOUNDARY FM WRN ND TO NERN SD TO SRN MN IS LOCATED NR KATY AT 15Z... WITH MORE SIG WAVE ALG ND/SD BRDR NW OF KABR. AS THIS AREA OF LOW PRESSURE RIPPLES ALG FNT INTO WCNTRL MN BY EARLY AFTN...WL SEE SFC TROUGH DRAG THRU CWA...REACHING FAR SE LATE. SOME LOW LVL CAA BEHIND TROUGH WL ENHANCE MIXING AS WELL. POTENTIAL FOR TMPS TO BE SEVERAL DEGREES WARMER THAN FCST TODAY IF FINDS WAY TO MIX OUT MORE THAN EXPECTED. HOWEVER...CONSIDERABLE HIGH AND SOME MID LEVEL CLOUDS SHUD TEMPER WARMING A BIT. GREATEST CONCERN IS AREAS WHERE CI SHIELD WL SHUD THIN FOR A WHILE INTO MIDDAY...KSUX TO KSPW REGION. WL RAISE TMPS AT LEAST A CAT SE CWA...IF NOT MORE...MUCH CLOSER TO MIXING POTENTIAL...AND BOOST WNDS INTO MIDDAY AS WELL. EXPECT WNDS IN SD CWA TO MIX BIT MORE N OF W THAN IN FCST AS WELL. FM LTR DAY VIEW YDA...SNOWCOVER IS QUITE PATCHY BUT MORE SIG IN POTHOLE LAKES REGION OF ECNTRL SD...ARCING SEWRD ALG BUFFALO RIDGE TO KSPW REGION. WERE SOME OBVIOUS SNOW FREE REGIONS IN THESE AREAS AS WELL WHICH BROUGHT SLIGHTLY WARMER TMPS EVEN WITH VERY WELL MIXED DAY...SO WL INTRODUCE SNOWCOVERED AREA WORDING TO SOME ERN ZNS. OVERALL...ONGOING FCST IN GOOD SHAPE AND UPDATES MOSTLY MINOR. .FSD...NONE CHAPMAN sd AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 945 AM CST SUN JAN 20 2002 SIGNIFICANT WEATHER CONTINES TO BE LACKING IN SHORT RANGE TODAY. MAIN BUT MINOR CONCERN FOR UPDATE WOULD BE WIND...CLOUDS AND TEMP. WK SFC TROUGH NOW ON THE EASTERN SIDE OF THE JAMES VLY...WHICH IS A SMIDGE AHEAD OF THE MESOETA/RUC POSITION. WKNG SFC WAVE ALG FRONTAL BOUNDARY FM WRN ND TO NERN SD TO SRN MN IS LOCATED NR KATY AT 15Z... WITH MORE SIG WAVE ALG ND/SD BRDR NW OF KABR. AS THIS AREA OF LOW PRESSURE RIPPLES ALG FNT INTO WCNTRL MN BY EARLY AFTN...WL SEE SFC TROUGH DRAG THRU CWA...REACHING FAR SE LATE. SOME LOW LVL CAA BEHIND TROUGH WL ENHANCE MIXING AS WELL. POTENTIAL FOR TMPS TO BE SEVERAL DEGREES WARMER THAN FCST TODAY IF FINDS WAY TO MIX OUT MORE THAN EXPECTED. HOWEVER...CONSIDERABLE HIGH AND SOME MID LEVEL CLOUDS SHUD TEMPER WARMING A BIT. GREATEST CONCERN IS AREAS WHERE CI SHIELD WL SHUD THIN FOR A WHILE INTO MIDDAY...KSUX TO KSPW REGION. WL HOLD OFF RAISING TMPS FOR NOW. EXPECT WNDS IN SD CWA TO MIX BIT MORE N OF W THAN IN FCST AS WELL. FM LTR DAY VIEW YDA...SNOWCOVER IS QUITE PATCHY BUT MORE SIG IN POTHOLE LAKES REGION OF ECNTRL SD...ARCING SEWRD ALG BUFFALO RIDGE TO KSPW REGION. WERE SOME OBVIOUS SNOW FREE REGIONS IN THESE AREAS AS WELL WHICH BROUGHT SLIGHTLY WARMER TMPS EVEN WITH VERY WELL MIXED DAY...SO WL INTRODUCE SNOWCOVERED AREA WORDING TO SOME ERN ZNS. OVERALL...ONGOING FCST IN GOOD SHAPE AND UPDATES MOSTLY MINOR. .FSD...NONE CHAPMAN sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 410 PM EST SUN JAN 20 2002 MAIN FCST CONCERNS ARE SNOW CHANCES/COVERAGE/AMOUNTS. WV IMAGERY AND RUC ANALYSIS INDICATED RELATIVELY ZONAL PATTERN ACRS NRN TIER OF THE CONUS BENEATH LINGERING NRN HUDSON BAY VORTEX. WEAK TROF AXIS EXTENDED FROM MANITOBA TOWARD NM. ONLY WEAK SHRTWVS EVIDENT INTO NW MN AND SW IA WHILE MAIN SHRTWV WITH THE TROF WAS LOCATED NEAR THE TX PANHANDLE. AT THE SFC...A TROF EXTENDED FROM A LOW OVER SW MN TO NW WI AND ERN LK SUPERIOR. 280-285K ISENTROPIC LIFT AHEAD OF MID LVL TROF SUPPORTED MAINLY INCREASING MID CLOUDS AND VIRGA AS VERY FEW REPORTS OF -SN SO FAR UPSTREAM OVER WI/MN. MDLS WERE IN GOOD AGREEMENT WITH RESPECT TO MAIN FEATURES AFFECTING UPR MI. THERE WERE SOME DIFFERENCES IN PLACEMENT OF LIGHT QPF AMOUNTS TONIGHT AS WELL AS QPF AND 850-500 MOISTURE BY MONDAY NIGHT. WHILE DRIER ETA SEEMS MORE REASONABLE COMPARED TO MORE BROAD BRUSH OF AVN...WL GIVE SOME WEIGHT TO THE AVN AS NEXT SHRTWV AND WEAK SFC LO MAY SQUEEZE OUT SOME LIGHT SNOW. TONIGHT INTO MONDAY...BROAD AREA OF WEAK 850-500 QVECTOR CONVERGENCE AND 280-285K ISENTROPIC LIFT AHEAD OF THE TROF PROGRESS ACRS UPR MI AS COND PRES DEF FALL BLO 20 MB. GIVEN FCST RELATIVELY WEAK LIFT AND SLOW PROGRESS IN SATURATING LLVLS...PER UPSTREAM OBS...HAVE DELAYED MENTION OF -SN TIL AFT 03Z FOR NORTH PORTION OF THE CWA. CAT WORDING WAS MENTIONED BUT FOR VERY LIGHT AMOUNTS. MIXING RATIO AT 700 MB NEAR 285K SFC AROUND 1 G/KG IS CONSISTENT WITH 1 INCH AMOUNTS DURING PERIOD OF BEST LIFT. ETA/AVN MDL QPF OF 0.05-0.10 INCH ALSO WOULD YIELD AMOUNTS OF NOT MUCH MORE THAN AN INCH. ALTHOUGH 12Z/18Z ETA SHOWS BEST 700 MB UPWARD MOTION A BIT FARTHER NW THAN AVN WL KEEP GENERAL INCH FCST. WITH ABSENCE OF LAKE INDUCED CLOUDS OVER NRN LK MI THIS AFTERNOON AND RELATIVELY WEAK DELTA/T TO AROUND 8C-9C AND 950 CONVERGENCE MAINLY WEST OF THE CWA DO NOT EXPECT LAKE ENHANCEMENT OVER SE PORTION OF THE CWA. LIFT/MOISTURE LINGER OVER ERN HLF OF THE CWA BTWN 12Z-15Z WITH CONTINUING POSSIBILITY OF -SN. TEMPS NEAR GUIDANCE VALUES AND ETA 2M TEMPS CLOSE TO 30F LOOK REASONABLE. MONDAY NIGHT INTO TUESDAY...CHANCE OF -SN MENTIONED WITH BEST QG FORCING AND LIFT WITH NEXT SHRTWV MAINLY NORTH OF UPR MI. MAIN LIFT AND DEEP MOISTURE WILL REMAIN NORTH OF UPR MI TUESDAY DESPITE STRENGTHENING WAA. STRONG SW FLOW SHOULD MIX SOME OF THE WARMER AIR TOWARD THE SFC WITH TEMPS AOA WARMER AVN GUIDANCE VALUES ESPECIALLY WITH DOWNSLOPE FAVORED LOCATIONS. TUESDAY NIGHT INTO WEDNESDAY...AVN/ETA/UKMET HAVE COME INTO BETTER AGREEMENT IN SUGGESTING A FASTER MORE SHEARED NRN STREAM TROF MOVING THROUGH THE WESTERN LAKES DRAGGING THE SFC TROF THROUGH UPR MI. EVEN THOUGH THE ETA CONTINUES TO KEEP THE DEEPER MOISTURE NORTH OF UPR MI...WL GO WITH AT LEAST 50 POPS AS SOME LGT PCPN EXPECTED IN VCNTY OF THE TROF...PER AVN. DAYS 4-7...ALTHOUGH THE ECMWF AND UKMET ARE LESS AGGRESSIVE WITH THE COLD AIR INTRUSION BY THURSDAY...EXPECT IT WILL BE COLD ENOUGH FOR SOME LES WITH H8 TEMPS DOWN TO NEAR -15C. NW OR BRIEFLY NNW FLOW WOULD FAVOR MAINLY THE WEST AND NE PORTIONS OF THE CWA WITH MQT SEEING ONLY BRIEF PERIOD FOR LES. RELATIVELY SHALLOW COLD AIR AND MOISTURE WOULD KEEP AMOUNTS GENERALLY LIGHT. TIMING DIFFERENCES EMERGE WITH PASSAGE OF RDG AND PROGRESS OF NEXT SHRTWV AND SFC LO DEVELOPING TO THE NW OF LK SUPERIOR. WL GENERALLY GO WITH ABV MRF GUIDANCE TEMPS AND ONLY LGT PCPN OR FLURRIES WITH THIS SYSTEM AS AMOUNT OF COLD AIR IS LIMITED WITH ZONAL FLOW DEVELOPING. .MQT...NONE. JLB mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX 254 PM CST SUN JAN 20 2002 UPDATED ZONES FOR WIND TRENDS AND ADDED MENTION OF BLOWING DUST FOR THE PLAINS AND ADJACENT MOUNTAINS. LATEST RUC SHOWS THE BAND OF STRONGEST WINDS AROUND 850 MB MOVING OVER THE REGION. WINDS OVER THE PLAINS WERE JUST UNDER WIND ADVISORY CRITERIA. MAY ISSUE A SHORT TERM NPW FOR THE NORTHERN AND CENTRAL PLAINS IF WIND SPEEDS CONTINUE ON THE BORDERLINE. WINDS IN THE DAVIS MOUNTAINS VIA MOUNT LOCKE OBSERVATIONS ARE NEAR WARNING CRITERIA...SAME THOUGHTS THERE. TERRELL COUNTY IS THE ONLY PLACE THUS FAR WITH WINDS REMAINING BELOW THE BREEZY CRITERIA (15-25 MPH). ALSO BUMPED UP HIGH TEMPS A CAT OR TWO FOR MOST AREAS. .MAF... TX...HIGH WIND WARNING UNTIL 20/2300 UTC FOR THE GUADALUPE MOUNTAINS OF CULBERSON COUNTY...TXZ258. ...WIND ADVISORY UNTIL 20/2300 UTC FOR THE DAVIS AND APACHE MOUNTAINS OF WEST TEXAS...NMZ074. NM...HIGH WIND WARNING UNTIL 20/2300 UTC FOR THE GUADALUPE MOUNTAINS OF EDDY COUNTY...NMZ027. RSB tx