AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 844 PM EST WED JAN 5 2000 WL UPDATE TO KEEP WORDING CURNT AND ADJUST WINDS. LTST RUC SHWING GOOD LWLVL WAA TO CONT WITH 925MB 12HR/V09Z DELTA T AROUND 4-5C. INCRSG SSWLY WINDS TO 35KTS LKLY TO CONT TO SCT OUT MVFR SC ACRS ALL BUT NRN TIER ZNS BUT WITH INCRSG 600-500MB MSTR WL CONT MCLDY WORDING THOUGH SOME SPOTS MAY SEE A CPL HOURS OF FEW-SCT020. TEMPS HAVE STEADIED AND WL RMN STEADY OR SLOWLY RISE. .IWX...NONE PBM in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 1120 PM EST WED JAN 5 2000 UPDATE ALREADY OUT TO MENTION LIGHT SNOW ENDING IN THE NORTH. LIGHT SNOWS ARE OF THE WAA VARIETY AS SEEN ON THE 290K SFC FROM THE RUC. SNOW ALREADY TAPERING OFF/LIFTING OUT AS PROGD BY THE RUC. OTHERWISE EXPECT MOSTLY CLOUDY SKIES THROUGH THE OVERNIGHT WITH NEAR STEADY TEMPS IN THE UPPER 20S. STEADY TEMPS AIDED BY THE CLOUDS AND THE FAIRLY STRONG GRADIENT THAT IS BUILDING IN WHICH WILL BOOST WINDS INTO THE 15-25 MPH CATEGORY. .GRR...NONE. mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1030 PM EST WED JAN 5 2000 MAIN FCST CONCERN OVERNIGHT IS TREND WITH -SN AND POTENTIAL FOR ADDITIONAL ACCUMULATIONS. WV IMAGERY SHOWED SHRTWV TO NW MN WHILE 02Z SFC ANALYSIS INDICATED SFC LO JUST WEST OF KINL AT 02Z. IR/WV LOOPS ALSO INDICATED BAND OF ENHANCED CLOUDS ASSOCIATED WITH PROGRESSIVE MID/UPR LVL TROF AND AREA OF UPR LVL DIV WITH RIGHT ENTRANCE TO JET FROM ERN ONTARIO INTO QUEBEC. CLOUD TOPS TO THE WEST WERE WARMING LAST FEW HOURS. KMQT 88D INDICATED BAND OF HEAVIER SNOW THAT BROUGHT INCH OF SNOW BTWN 00Z-01Z AT NWS OFFICE QUICKLY DEPARTING TO THE EAST. THIS WAS SUPPORTED BY RIBBON OF STRONG 280-290K ISENTROPIC LIFT ON NOSE OF 50+ KNOT LLJ. AREA OF LIGHTER SNOW OVER NW WI AND WRN UPR MI MAINLY ASSOCIATED WITH 700-300 QVECTOR CONVERGENCE AHEAD OF THE MID LVL TROF...PER BACK EDGE OF SNOW HAD ALREADY MOVED TO NEAR KASX. CURRENT TRENDS WOULD BRING THIS BAND THRU WRN UPR MI BY 06Z AND CNTRL UPR MI BY 09Z. VSBYS TO THE WEST GENERALLY 1-3SM AT THE LOWEST...ONLY WEAK TO MODERATE REFLECTIVITIES... AND LITTLE IN WAY OF QPF SINCE 00Z. SO...WL WORD ADDITIONAL ACCUMULATIONS AS AN INCH OR LESS. SOME -FZDZ NOTED VCNTY KDLH BEHIND AREA OF SNOW AND WITH LLVL CONVERGENCE AHEAD OF SFC TROF. 00Z RUC SNDGS ALSO SHOW DRYING ABV 800 MB AND -10 ISOTHERM AT KIWD BY 09Z AND CNTRL UPR MI BTWN 09Z-12Z. WL ADD MENTION FOR PATCHY -FZDZ LATE. CAA BEHIND TRAILING COLD FRONT OVER CNTRL MN WL NOT REACH AREA TIL AFT 12Z...SO TEMPS STEADY OR RISING SLIGHTLY WITH CONTINUED WAA. .MQT...GALE WARNING E LAKE SUPERIOR OVERNIGHT. JLB mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1006 PM EST WED JAN 5 2000 SNOW HAS STARTED IN EASTERN UPPER AND IN PORTIONS OF NORTHWEST LOWER. LOW OVER NORTHERN MINNESOTA WITH WARM FRONT PROVIDING ISENTROPIC LIFT OVER THE AREA. THE MESOETA AND THE RUC SEEM TO BE HANDLING THE SNOW PRETTY WELL. WILL LEAVE THE AMOUNTS AND ADVISORIES ALONE. THE ONLY MAJOR CHANGES ARE IN THE WINDS, ESPECIALLY ALONG LAKE MICHIGAN. WITH KISQ AND KP75 REPORTING WINDS OFF OF THE LAKE SUSTAINED AT 25KTS AND GUSTS TO 30KTS UPPED THE WIND TO 20 TO 30 MPH IN THE MACKINAC COUNTY ZONE WITH GUST TO 40 MPH ALONG THE LAKE. UPPED THE WINDS IN NORTHWEST LOWER FOR THE LAKESHORE COUNTIES TO 15 TO 25 WITH HIGHER GUSTS. OTHERWISE...THE FORECAST LOOKS GOOD CHANGED ONLY THE DEVELOPING SNOW WORDING TO SNOW. ZONES ALREADY OUT. .APX...SNOW AND BLOWING SNOW ADVISORY...TONIGHT...MIZ015. LUTZ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1208 PM EST WED JAN 5 2000 UPDATE CONCERNS ARE LES POTENTIAL FOR DELTA...SCHOOLCRAFT...AND SOUTHERN LUCE COUNTIES AS COLD SOUTHERLY FLOW SETS UP OVER NRN LAKE MICHIGAN. THEN SYNOPTIC SNOW THIS AFTN AND EVENING OVER WRN UPR. ATTM...LOW PRESSURE CNTRD OVR ERN ND WITH CFNT TRAILING SOUTH INTO WRN NEBRASKA. REMNANTS OF MIDWEST-ERN GT LAKES RIDGE BEING REPLACED WITH TIGHTENING PRESSURE GRADIENT EVIDENCED BY SOUTH WIND GUSTS OVR 20 MPH IN IWD. ERN EDGE OF SYSTEM SNOW AREA BETWEEN DLH AND THE APOSTLE ISLANDS. IR LOOP SHOWS MID AND HIGH CLOUDS OVERSPREADING WRN 2/3 OF CWA. KMQT 88D VWP INDICATES CLOUD COVER 100-220. 12Z AVN...RUC AND ETA CARRY 18Z H8 TEMPS -12 TO -14C OVR THE LAKE MICH SHORELINE OF DELTA AND SCHOOLCRAFT WITH A 15KT FLOW FROM THE SOUTH. NGM IS A COUPLE OF DEGREES WARMER. PER GLERL SATELLITE DERIVED LAKE SFC TEMP ANALYSIS...MOST OF LAKE MICH ABOUT 5C BUT 3-4C NEAR UPR MICH SHORELINE. RESULTANT DELTA-T'S 16-18C. RUC MAINTAINS SFC-950MB INVERSION THRU 18Z...WASHING IT OUT BY 21Z WITH DRY AIR 900-700MB. ETA'S 18Z CAP IS 900-850MB BREAKING BY 00Z WITH T-TD DEPRESSIONS LT 5C THRU 500MB. WINDS VEER SSW TO WSW 25-20 KTS SFC-800MB. BY 00Z...H8 TEMPS AVG -10C FOR DELTA-T 14C WHICH HOLDS THROUGH 06Z THURS AM THEN WARMING TO -8 TO -9 12Z THURS... AFTER WHICH WINDS BEGIN TO VEER TO THE SOUTHWEST. THIS LAKE EFFECT CONCERN AREA REMAINS UNDER 700-500MB QVEC DIVGC AND NIL 700MB UVV THRU 18Z...AFTER WHICH QVEC CONVGR AND H7 UVV COME INTO PLAY IN ADVANCE OF INCOMING SYSTEM FROM THE WEST. MESOETA PICKS UP ON THIS BY BRINGING PRECIP OVR NRN LK MICH BY 00Z... A FEW HRS IN ADVANCE OF SYSTEM PRECIP SHIELD MOVING IN FROM THE WEST. LES DECISION TREE SUPPORTS PURE LES 1-3"/6HR DELTA AND SCHOOLCRAFT DURG AFTN PRIOR TO SYSNOPTIC SCALE DYNAMIC SUPPORT. THIS EVENING WE MOVE TO THE COMBINATION BRANCH AS DYNAMIC SUPPORT MOVES IN...H7 OMEGA 2 MICROBARS/SEC INCREASING TO 3. MEANWHILE...DELTA-T'S DECREASING TO 14C AS PREVIOUSLY DESCRIBED...SO 1-3"/6HR EARLY INCREASING JUST SLIGHTLY LATE. CWA IN 285K INCREASING ISENTROPIC ASCENT WITH 1.5-2G/KG SPECIFIC HUMIDITY ADVECTING INTO WRN UPR MI THIS AFTN AND EVENING. IMR TECHNIQUE POINTS TO 2-4"/12HR SNOWFALL RATE. ZONES UPDATED ACCORDINGLY .MQT...NONE. JP mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1102 AM EST WED JAN 05 2000 CURRENTLY THE SURFACE CHART SHOWS A HIGH PRESSURE RIDGE OVER THE NORTHERN GREAT LAKES... FROM A HIGH CENTER OVER THE OHIO VALLEY. THE SURFACE CHART ALSO SHOWS A STORM SYSTEM CURRENTLY MOVING EASTWARD OVER THE DAKOTAS. VISIBLE STLT AND SURFACE REPORTS SHOW BREAKS IN THE CLOUDS OVER NORTHEAST AND NORTH CENTRAL LOWER MICHIGAN... WITH THE LAKE MICHIGAN SHORELINE REMAINING UNDER MOSTLY CLOUDY SKIES. THE MAIN QUESTION THIS AFTERNOON WILL BE THE CHANCE FOR SOUTHWEST FLOW LAKE EFFECT SNOW OVER EAST UPPER AND NORTHWEST LOWER. MESO ETA AND RUC MODEL DATA SHOWS 850 TEMPERATURES TO WARM FROM -15C THIS MORNING TO -12C BY EVENING ACROSS NORTHERN LOWER. LOW LEVEL MOISTURE AND ANTICYCLONIC FLOW OVER THE STATE THIS AFTERNOON WILL HELP HINDER THE CHANCES OF LAKE EFFECT SNOW. HOWEVER OVER LAKE INSTABILITY... SOUTHWEST FLOW AND APX 88D AND VIS STLT BEGINNING TO INDICATE THE EVIDENCE OF LAKE EFFECT BANDING OVER NORTHERN LAKE MICHIGAN...WILL KEEP A MENTION OF LIGHT LAKE EFFECT SNOW SHOWERS OR FLURRIES OVER LAKE THE LAKE MICHIGAN SHORELINE AND EAST UPPER MICHIGAN. WITH SURFACE RIDGING AND LIMITED MOISTURE OVER NORTHEAST LOWER MICHIGAN THIS AFTERNOON... WILL GO WITH CURRENT VIS STLT AND SURFACE OBSERVATIONS AND MENTION PARTLY SUNNY SKIES. APX...NONE. SWR mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBUQUERQUE NM 430 AM MST WED JAN 5 2000 RETRANSMISSION SHORT WAVE DROPPING INTO THE 4 CORNERS HAS HAD MOST OF ITS MOISTURE RUNG OUT BEFORE REACHING NM AND WILL ONLY MENTION VERY LOW POPS NRN MTNS TODAY. YET ANOTHER SHORT WAVE PROGGED TO DROP SEWD THROUGH AZ LATE TODAY INTO THIS EVENING...THEN SETTLING INTO SW/SCNTRL NM THU. LATEST RUC SEEMS TO SUPPORT THIS DEPICTION BY THE BIG 3. SO IT/S YET ANOTHER WRINKLE ADDED BY THE LATEST MDLS RUN. NO SUPRISE THIS WINTER. WHILE UPPER MOISTURE PROGGED TO SHOW LITTLE INCREASE ACROSS NM WITH THIS SYSTEMS TONIGHT INTO THU...MID AND LOWER LEVEL MOISTURE DOES INCREASE SOME. AIR BONE DRY NOW AND SOME OF THE LOWER LEVEL MOISTURE IS PROGGED TO ADVECT FROM N/NE INTO NE/ECNTRL NM TONIGHT BEHIND SFC WIND SHIFT/COLD FRONT THAT MOVES SE THEN S ACROSS NM NEXT 24 TO 30 HRS. DYNAMICS AND WHAT MOISTURE THERE IS DON/T OVERLAP ALL THAT WELL WITH WHAT DYNAMICS THERE ARE A LITTLE S OF GREATER RH. UPPER LVL DIVERGENCE NOT AT ALL IMPRESSIVE...BUT Q VECTOR ANALYSIS INDICATES WEAK PCPN SUPPORT FOR CENTRAL MOUNTAINS AND SOMEWHAT TO E AND SE FOR LATER TONIGHT INTO EARLY TO MID THU. THERE IS SOME INDICATION OF SLIGHT UPSLOPE COMPONENT TO LOW LVL WIND FOR E ALSO. SO ADDED MORE CLOUDS TO PREVIOUS FCST THOSE AREAS AND LOW POPS...NOTHING ABOVE 10/S...FOR LATER TONIGHT INTO THU. FWC POPS QUITE LOW ALSO. WOULD NOT BE SUPRISED IF NOTHING OTHER THAN SOME CLOUDINESS HAPPENS ...BUT CAPRICIOUS NATURE OF WEATHER SYSTEMS THIS LATE FALL/WINTER SO FAR MAKE ME RELUCTANT TO MAKE ABSOLUTELY NO MENTION OF PCPN. NO SIGNIFICANT CHANGES TO EXTENDED FORECAST. 43 ABQ AB 046/019 041/017 044 430-- SAF BB 041/012 036/011 039 43--- TCC AB 056/024 046/023 049 4301- .ABQ...NONE. nm AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 950 AM EST WED JAN 5 2000 DISC: CURRENT OBS SHOWING MOST STNS RPTNG NEARLY CLR SKIES. SAT PIX SHOW GD AMOUNT OF DOWNSLOPING AND THIS WL HELP IN KPNG CLR SKIES. BUFKIT DATA SHOWS THAT WITH THE DRY ADIABATIC PROFILE TO ARND 5K WNDS CAN STY GUSTY THROUGH AFTN HRS. CAA STL SPILLING TO RGN AND WNDS SHD STAY UP THRU LATE AFTN. GRAD SHD BEGIN TO RELAX SOME DURING THE AFTN HRS AND THIS TO WL HELP WITH THE WNDS BEGINNING TO DIMINISH. WL REWORD THE FCST FROM BECMG M/SUNNY TO SUNNY. TEMPS ARE SLOW TO REBOUND AND MAY LWR TEMPS JUST A TAD. LATEST RUC SHOWS THE UPR TROF IS JUST ABOUT OVR THE RGN NOW AND AS ITS PASSES TO OUR E THE WNDS WL SLOWLY BEGIN TO DROP OFF TWRD THE AFTN HRS. MARINE...WNDS ARE STL RUNNING JUST BLO GALE FORCE. WITH GRAD AT ITS PEAK...THE WNDS SHD STRT TO COME DOWN DURING AFTN HRS. WL LV THEM AT A STRG SMALL CRAFT. .OKX...SCA ADVISORY FOR CSTL WTRS...LI SOUND AND NY HARBOR...ANZ350-353-355-330-335-338. GSK ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORMAN OK 1100 AM CST WED JAN 5 2000 WIND ADVISORY ALREADY ISSUED FOR PARTS OF WC AND NW OK WHERE MESONET SHOWS PERSISTENT GUSTS IN 40-50 MPH RANGE. WITH PROFILERS STILL SHOWING 40-50KT AT 850MB, AND ETA/RUC INDICATING STRONG PRESSURE GRADIENT CONTINUING AND SHIFTING E MORE INTO CENTRAL/E OK THIS AFTERNOON, WE WILL INCREASE SPEEDS TO 20-30 MOST AREAS AND EXPAND LAKE CAUTION TO INCLUDE ALL BUT EXTREME SE OK THIS AFTERNOON. SKY CONDITIONS CHANGED TO SUNNY OVER ALL BUT NW. GUSTS OVER 40MPH NOW SHOWING UP IN PARTS OF CENTRAL OK ON MESONET. WILL CONTINUE TO MONITOR FOR POSSIBLE EXTENSION OF WIND ADVISORY INTO CENTRAL OK EARLY THIS AFTERNOON IF SPEEDS CONTINUE TO INCREASE. .OUN... OK...WIND ADVISORY THROUGH MIDAFTERNOON OKZ006-011-014>017. CAUTION ON AREA LAKES THIS AFTERNOON OKZ004>042-044>046-050. TX...CAUTION ON AREA LAKES THIS AFTERNOON TXZ083>090. ok AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 948 AM EST WED JAN 5 2000 EARLY VISIBLE IMAGES SHOW CLOUDS LINGERING ALONG THE NORTH CAROLINA/TENNESSEE BORDER..AND ARE BREAKING UP ALONG THE EASTERN ESCARPMENT. ELSEWHERE...CLEAR SKIES THE RULE. UPDATED ZONES A LITTLE BIT AGO TO REMOVE THE SNOW WORDING...SINCE SURFACE REPORTS INDICATE THAT NO SNOW HAD FALLEN IN THE NORTHERN MOUNTAINS IN THE PAST FEW HOURS AND THAT BREAKS IN THE OVERCAST HAD BEGUN. SKIES SHOULD STAY CLEAR THROUGH THE AFTERNOON OUTSIDE OF THE MOUNTAINS AND WE WILL SEE THE RESIDUAL CLOUDS IN THE MOUNTAINS GRADUALLY ERODE AS FLOW BECOMES PARALLEL TO THE TERRAIN AND WITH DRIER AND COLDER AIR ADVECTING INTO THE REGION FROM THE NORTH. LOCAL THICKNESS SCHEME SUPPORTS MAXES IN THE MIDDLE 40S JUST ABOUT EVERYWHERE...EXCEPT FOR MOUNTAINS. TEMPERATURES RUNNING BETWEEN 36 AND 40 DEGREES AS I WRITE THIS...AND WITH CONTINUED COLD ADVECTION THIS AFTERNOON...DO NOT PLAN TO MAKE ANY CHANGES TO THE CURRENT FORECAST MAXES. MESO-ETA...RUC AND ETA BUFKIT SUPPORT THE 00Z MODEL TRENDS OF A WEAKENING PRESSURE GRADIENT DURING THE DAY. WILL EVALUATE BEFORE FINAL ISSUANCE...BUT ANY CHANGES TO OUR WIND FORECASTS WILL BE MINIMAL FOR THE MORNING UPDATE. .GSP...NONE. BURRUS sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 309 AM CST THU JAN 6 2000 AWIPS AND AFOS PROBLEMS HAVE PUT ME WAY BEHIND SCHEDULE. ZONES WILL BE VERY LATE BUT SHOULD BE OUT BY 415 AM. ...GLOBALLY... LONGWAVE ANALYSIS SHOWS A LOW AMPLITUDE 3-4 WAVE PATTERN WITH FAST FLOW ACROSS THE HEMISPHERE IN A JET OF 100-120 KNOTS. GLOBAL WATER VAPOR MOSAIC SHOWS SEVERAL STRONG SHORTWAVES (I COUNT AT LEAST 5 FROM THE GULF OF ALASKA BACK ACROSS THE PACIFIC INTO SIBERIA) AND JET STREAKS OF 130+ KNOTS (BASED ON DARKNESS) EMBEDDED IN THE OVERALL FLOW. NEWEST USAF SNOW COVER ANALYSIS SHOWS AREAS NORTH OF 50N ACROSS NORTH AMERICA AND 45N ACROSS ASIA/EASTERN EUROPE NOW HAVE A WELL ESTABLISHED SNOW PACK. ACROSS THE CONUS SNOW FIELDS EXTEND DOWN TO 40N BUT ARE SHIFTING ALMOST DAILY DUE TO WARM TEMPERATURES. LONGWAVE TRENDS CONTINUE TO INDICATE THAT AN EXTENSIVE AREA OF ZONAL FLOW SETTING UP ACROSS THE PACIFIC AND NORTH AMERICA AND GLOBAL MODELS CONFIRM THIS DEVELOPING BY THIS WEEKEND. HOWEVER THIS EXTENSIVE AREA OF ZONAL FLOW CANNOT BE MAINTAINED WITH REAMPLIFICATION OCCURRING. GLOBAL MODELS CONFIRM THIS WITH A LARGE AMPLITUDE RIDGE DEVELOPING IN THE ALEUTIANS NEXT WEEK. WAVELENGTH THEN PLACES A DEEP TROF JUST OFF THE WEST COAST WITH A DOWNSTREAM RIDGE ACROSS MUCH OF NORTH AMERICA. NET RESULT HERE IS THAT AFTER ANOTHER QUICK SHOT OF ARCTIC AIR TEMPERATURES WILL MODERATE FOR THE WEEKEND AND SHOULD AVERAGE ABOVE NORMAL FOR MUCH OF NEXT WEEK. PRECIPITATION SHOULD BE BELOW NORMAL AS THE MAIN JET GETS PUSHED WELL NORTH OF THE AREA. ...LOCALLY... WATER VAPOR AND PROFILER DATA SHOW THE CURRENT ALBERTA CLIPPER MOVING INTO THE GREAT LAKES REGION WITH THE SHORTWAVE TROF MOVING ACROSS IOWA TOWARD ILLINOIS/WISCONSIN. THE NEXT SHORTWAVE IS DIVING SOUTHEAST INTO THE NORTHERN PLAINS. IR AND FOG PRODUCT SHOW MAINLY AC/CI ACROSS THE AREA WITH THE BULK OF THE LOW CLOUDS NORTH OF THE FORECAST AREA. HOWEVER A FINGER OF LOW CLOUDS EXTENDS SOUTH INTO IOWA. 06Z SURFACE ANALYSIS HAS A WEAK COLD FRONT/TROF RUNNING FROM THE ARROWHEAD OF MINNESOTA TO THE KMCI METRO AREA WITH THE ARCTIC FRONT MOVING INTO SOUTH DAKOTA AND NORTHWEST MINNESOTA. A WEAK SURFACE LOW WAS LOCATED NEAR KCDS. MOISTURE ANALYSIS SHOWS LOW TO MID 20 DEW POINTS ACROSS THE AREA WITH SINGLE DIGIT AND TEEN DEW POINTS BEHIND THE ARCTIC FRONT. DVN 88D SHOWS REMNANTS OF --SN/-SN EXITING THE AREA AROUND KRFD. PROBLEMS THIS PACKAGE ARE CLOUDS/TEMPERATURES AND PRECIP CHANCES. 00Z MODELS APPEAR TO HAVE INITIALIZED OK BUT THE NGM WAS DOING BETTER IN POSITION AND STRENGTH WISE AT 06Z ALBEIT STILL A TAD WEAK. ETA WAS WEAKER STILL WITH THE AVN BEING A LITTLE FAST. RUC SHOWS QG FORCING WEAKING WITH CONDENSATION PRESSURE DEFICITS RISING AS SHORTWAVE MOVES EAST OF THE AREA SO WILL GO DRY FOR TODAY. ARCTIC FRONT TO MOVE THROUGH THE AREA LATE THIS MORNING/AFTERNOON WITH THICKNESSES FALLING THROUGH 06Z TONIGHT. NEXT SHORTWAVE PROGGED TO MOVE THROUGH THE AREA TONIGHT WITH CONDENSATION PRESSURE DEFICITS LOWERING AGAIN WITH SOME QG FORCING. THUS FLURRIES AT BEST FOR TONIGHT WITH THE FLURRIES LIKELY TO OCCUR IN A 6 HOUR PERIOD. AVN/NGM SHOW QG FORCING WEAKENING AND CONDENSATION PRESSURE DEFICITS QUICKLY RISING AGAIN BY 12Z SO WILL NOW KEEP FRIDAY DRY. SYSTEM AFTER THAT SHOULD REMAIN NORTH OF THE FORECAST AREA IN THE FRIDAY NIGHT/SATURDAY TIME PERIOD SO WILL KEEP THE CURRENT DRY FORECAST. TRAJECTORY METHOD YIELDS TEMPERATURES IN THE 30S TODAY WHICH AGREES FAIRLY WELL WITH FWC/FAN NUMBERS. ...EXTENDED... DUE TO RUNNING BEHIND WILL NOT TOUCH EXTENDED WITH IT LOOKING GOOD ATTM. MODELS SHOW VORTEX OVER ALASKA TO DROP SOUTH AND DEEPEN WITH RIDGE BUILDING UP FROM THE SOUTH. JET WILL GET COMPRESSED ACROSS THE EASTERN PACIFIC AND STRENGTHEN SIGNIFICANTLY. THE LAST TIME THIS HAPPENED THE MODELS UNDER ESTIMATED THE ACTUAL JET SPEED BY 20-30 KNOTS. THUS THE SYSTEMS THAT ENTER THE JET IN THIS AREA WILL STRENGTHEN AND SPEED UP CONSIDERABLY. DUE TO TIMING PROBLEMS CURRENT SUNDAY MENTION OF RA/SN LOOKS GOOD. COORDINATED WITH DSM...LSE...CHI...ILX...AND STL. .DVN...NONE. NC il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 245 PM CST WED JAN 5 2000 LATEST SFC AND MSAS ANALYSIS INDICATING SFC LOW ENTERING INTO FAR NORTHWEST MN...WITH PRESSURE FALLS BUILDING ACRS AND NORTH OF MN ARROWHEAD...SHOWING THE WAY OF SFC WAVE PROPAGATION. STIFF SFC-H85 SOUTHERLY FLOW BUILDING ACRS IA AHEAD OF TROUGH IN TIGHT GRADIENT... WITH WAA AT THESE LEVELS KICKING IN ERNEST. MAIN FORECAST CONCERNS IN NEAR TERM ARE EXTENT OF WARMING TEMPS OVERNIGHT AND PRECIP CHANCES. SHORT RANGE MODELS GENERALLY TREND TO SHARPENING POSITIVE TILTED S/W ACRS UPPER MIDWEST THROUGH 36 HRS/00Z FRI...AND CONTINUES ACRS WESTERN GRT LKS THROUGH 12Z FRI. MODELS HAVE CONVERGED IN GENERAL SPEED AND TIMING OF WAVE...BUT PREFER BIT DEEPER AVN AND NGM SOLUTIONS...LOOKING AT LATEST SYSTEM TRENDS ON W/V IMAGERY. ALSO LOOKING AT W/V...AVN AGAIN SEEMS TO HAVE INITIALIZED BEST WITH VORT PLACEMENT AT 18Z JUST SOUTHWEST OF LAKE WINNIPEG...ALTHOUGH ETA AND RUC SEEM TO BE CORRECTLY MORE VIGOROUS WITH VORT STRENGTH. WILL AGAIN TAKE AVN/ETA HYBRID...LEANING TO AVN POSITIONING AND ETA STRENGTHS WITH UPPER LEVEL SYNOPTIC SCALE FEATURES. LOOKING AT SFC SYSTEM AT 18-19Z...NGM ACTUALLY BEST WITH SFC LOW STRENGTH AND PLACEMENT OVER ND/MN BORDER. STILL LOOKING AT LATEST SFC/MSAS TRENDS AND PRESSURE FALLS...SFC SYSTEM LOOKS TO FOLLOW QUICKER ETA TIMING AND PROGRESS EAST ACRS FAR NORTHERN MN THROUGH EARLY EVENING...AND EVENTUALLY TO NORTHEAST OF THUNDER BAY BY 18Z THU...WITH SECONDARY SFC TROUGH SWINGING ACRS WESTERN GRT LKS BEHIND IT. AT 18Z...ETA NOT FAR ENOUGH EAST WITH PRECIP BANDS IN NORTHWEST IA. AVN BETTER WITH AREAL EXTENT INITIALLY. LOOKING AT 88D REGIONAL MOSAICS AND PRECIP TRENDS...ETA/AND NGM/ LOOK TO BE CORRECTLY SHIFTING BULK OF PRECIP NORTHEAST OVERNIGHT INTO FAR EAST MN AND WI. WHILE NGM PRODUCES LITTLE IF ANY PRECIP ACRS CWA OVERNIGHT...ETA GLANCES FAR NORTHERN TIER OF CWA WITH A TENTH OF SNOW...MAINLY FROM 05Z-12Z. AVN BRINGS IN BROADER SWATH/TYPICAL BIAS/ OF LIGHT SNOW ACRS NORTHERN HALF OF CWA WITH A FEW TENTHS OF ACCUMULATION... STARTING EARLIER BEFORE 06Z. 285-290 K ISENTROPIC ANALYSIS AGAIN SHOWS THIS SYSTEM PRODUCING GOOD LIFT...PEAKING ACRS CWA AROUND 03Z- 06Z. ALTHOUGH SPECIFIC HUMIDITIES SUPPORT 1-2 INCH ACCUMULATION ACRS THE NORTHERN THIRD OF CWA...LIFT NO WHERE NEAR 12 HRS...AND COND PRES DEFICITS INDICATE LIFT GOING INTO SATURATION. MODELS INDICATE ATMOSPHERE ACRS NORTHEAST IA/NORTHWEST IL HAVING TROUBLE SATURATING TO EVEN 40-50 MB...EATING AWAY AT PRECIP CHANCES AND AMOUNTS. EVEN FCST SOUNDINGS FOR TONIGHT POINT THIS OUT AND HAVE TROUBLE SATURATING LOWER LEVELS. NICE H85-H5 CONVERGENT QG FORCING BAND SWEEPS ACRS CWA THROUGH THIS EVENING...BUT PRECLUDES BETTER ISENTROPICS. FEEL MOST OF CWA THAT SEES ANYTHING WILL BE LIGHT WITH LITTLE OR NO ACCUMULATION...DUSTING. TEMPS MAY BE TRICKY TONIGHT WITH STRONG SFC-H85 WAA CONTINUING OVERNIGHT UNTIL TROUGH PASSAGE TOWARD 12Z THU. SNOW COVER WILL TEMPER UPSTREAM WARM READINGS...BUT TEMPS SHOULD STILL BE ON THE SLOW RISE FOR A PERIOD TONIGHT. MODELS LOOK TO BE UNDER-PLAYING EXTENT OF WARMING TONIGHT...ESPECIALLY AT H85. STIFF H85 WIND TO 50 KT SHOULD CONTINUE TO AT LEAST 06Z ACRS CWA...BUT QUICKLY VEER NORTHWEST TOWARD 12Z AND USHER IN COOLER TEMPS. UNDERPLAYED H9-H85 WARMING TONIGHT MAY ALLOW FOR SOME SLEET/SNOW GRAINS MIXED IN WITH ANY PRECIP THAT DOES DEVELOP. MODELS SWEEP SECONDARY VORT ACRS UPPER MS RVR VALLEY THU NIGHT WITH BRISK CYCLONIC FLOW ALOFT...BUT MOISTURE STARVED SYSTEM SHOULD ONLY MILK OUT FLURRIES. SUBSIDENCE/CLEARING TO BUILD IN QUICKLY BEHIND SYSTEM ON FRI...H85 -15 C TO -18 C COLD POOL SWEEPING ACRS AREA SUPPORTS MUCH COOLER FWC HIGHS FOR FRI. ...LOOKING AT EXTENDED...MRF/CANADIAN/ AND EUROPEAN ALL CONTINUE PROGRESSIVE ZONAL FLOW OFF PACIFIC NORTHWEST TO START OFF THE WEEKEND...WITH EURO AND CANADIAN INITIALLY CONTINUING TRENDS OF FLOW EMBEDDED SFC SYSTEMS FURTHER NORTH OF CANADIAN BORDER THAN THE MRF. IN ANY CASE...DRY AND MODERATING WX IN STORE FOR SATURDAY. BRISK PROGRESSIVE FLOW LOOKS TO AMPLIFY ON SUNDAY ACRS UPPER MIDWEST. CANADIAN AND ESPECIALLY MRF DEEPEN UPPER TROUGH IN RESPONSE TO VIGOROUS PACIFIC S/W DROPPING ACRS UPPER MIDWEST...EVENTUALLY BRINGING THREAT OF PRECIP TO DVN CWA. LESS AMPLIFIED EURO CONTINUES WITH BRISK ZONAL FLOW ACRS NORTHERN HALF OF THE CONUS AND DROPS VORTEX ACRS GRT LKS LATER ON MONDAY. AM LEANING TO MRF AND SOMEWHAT THE CANADIAN AND WILL INTRODUCE THREAT OF PRECIP ON SUNDAY. PRECIP LOOKS TO START LATER IN AFTERNOON...BUT WITH PROGRESSIVE SYSTEM AND BEING IN EXTENDED...WILL LEAVE CHANCE FOR WHOLE DAY. MRF 1000- 500 MB THICKNESSES SUPPORT RAIN/SNOW MIX...BUT FEEL SFC-H85 TEMPS WARM ENOUGH FOR ALL RAIN AT ONSET. PARAMETERS THEN COOL OFF TO ALL SNOW CRITERIA AS FRONT SWEEPS THROUGH SUNDAY NIGHT. MRF THEN CONTINUES -S INTO MONDAY AS MAIN PRECIP BAND SHIFTS EAST OF CWA... BUT WRAP AROUND AND CYCLONIC FLOW/LINGERING PVA ALOFT ROTATE ACRS AREA. ALTHOUGH TEMPS STILL LOOK TO MODERATE THROUGH SUNDAY...FEEL FMR STILL TOO MILD AND WILL AGAIN UNDERCUT. COORDINATED WITH LSX...THANX. .DVN... IA...NONE. IL...NONE. MO...NONE. JDH il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 830 PM CST WED JAN 5 2000 RUC MODEL THIS EVENING WAS DEPICTING A RATHER LARGE AREA OF 700-500 LAPSE RATES OVER 7C WESTERN AND SOUTHERN MN. A BULLS EYE OF 400 MB POTENTIAL VORTICITY ADVECTION ALSO INDICATED OVER SOUTHEAST MN INTO WEST CENTRAL WISC. ENHANCED BAND OF SNOW REMAINED OVER A SMALL PART OF WEST CENTRAL WISC THIS EVENING. FORCING MOVES OUT BY MIDNIGHT AND THEN LEFT WITH CLOUDS. A FEW FLURRIES MAY INVADE NORTH PART OF CWA YET TONIGHT. 100 PLUS KNOT JET DIGGING INTO N ROCKIES WILL SHARPEN UP TROUGH ON THU AS ARCTIC OOZES IN. MAY BE MORE WIDESPREAD -SHSN OVER MOST OF CWA. WILL ADJUST TEMPS UP A BIT OVERNIGHT IN S BEFORE COLD AIR ARRIVES AND THEN FALLING THU MORNING. .MSP...WINTER WEATHER ADVISORY UNTIL MIDNIGHT..MNZ078..WIZ024>028 JPR mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE COLUMBIA SC 215 AM EST THU JAN 6 2000 THE MAIN FORECAST PROBLEM IS THE TIMING OF THE CLOUDINESS ASSOCIATED WITH THE ONSHORE FLOW AND ISENTROPIC LIFT. THE ETA IS STILL THE FASTEST AND SUGGESTS IT WILL BECOME CLOUDY LATE THIS MORNING. SATELLITE AND THE RUC SUGGESTS THE CLOUDINESS WILL BE WELL SOUTHEAST OF THE FORECAST AREA AT 12Z SO THE ETA/S FORECAST APPEARS TOO FAST. PLAN TO COMPROMISE BETWEEN THE NGM AND AVN AND FORECAST SKIES TO BECOME CLOUDY DURING THE MIDDLE TO LATE AFTERNOON. PLAN TO CUT THE FWC/FAN TEMPERATURES SLIGHTLY DUE TO THE AFTERNOON CLOUDINESS. THE CONTINUED ISENTROPIC LIFT SHOULD KEEP SKIES CLOUDY TONIGHT SO THE GUIDANCE TEMPERATURES APPEAR TOO COLD. EXPECT DECREASING CLOUDINESS FRIDAY DUE TO LOW-LEVEL COLD ADVECTION AND DOWNSLOPE FLOW. PLAN TO USE THE FWC/FAN/LOCAL CONSENSUS FOR TEMPERATURES FRIDAY. THE MODELS ARE CONSISTENT IN KEEPING THE MOISTURE SHALLOW AND LIFT WEAK SO DO NOT BELIEVE POPS ARE NEEDED. CAE...54/40/62/35 0/1/0 AGS...54/40/62/35 0/1/0 .CAE...NONE. RJL sc TEXAS/OKLAHOMA PANHANDLES FORECAST DISCUSSION NATIONAL WEATHER SERVICE AMARILLO TX 916 PM CST WED JAN 5 2000 CDFNT THAT MOVED THROUGH AMA EARLIER THIS AFTN NEARLY STATIONARY ACROSS SE TX PNHDL INTO NRN SOUTH PLAINS THIS EVE. SFC DPTS HAVE RISEN BEHIND BOUNDARY WITH WEAK UPSLOPE FLOW CONTINUING ACROSS ALL BUT NW SECTIONS. MID CLOUD DECK ACROSS KS SHOWED SIGNS OF DEVELOPING SWRD FOR A WHILE. THIS APPARENTLY ASSCD WITH MID LEVEL FRONTOGENESIS EVIDENT ON 00Z RAOB DATA AND 00Z RUC THOUGH APPEARS WEAKENING NOW. MID LEVEL TROUGH AXIS FCST TO SLOWLY ROTATE TOWARD FA OVERNIGHT SO THERE IS STILL A THREAT OF SOME CLOUDS MOVING INTO MAINLY NW ZNS. SOME ENHANCEMENT SEEN ON KPUX RADAR LOOP HOWEVER AIRMASS EXPECTED TO REMAIN TOO DRY FOR PRECIP IF CLOUDS DO MOVE IN. WINDS EXPECTED TO SHIFT BACK N TONIGHT AS SFC RIDGE AXIS SLIDES S. ALREADY SEEING THIS ACROSS NRN ZNS SO WILL NOT ADJUST FCST FOR WINDS ANY. .AMA... TX...NONE. OK...NONE. COBB tx SOUTHEAST TEXAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX 840 PM CST WED JAN 5 2000 DEWPOINTS INCREASING OVER SOUTHWEST ZONES BUT NOT AS QUICK AS WHAT RUC WOULD INDICATE. SATELLITE (11-3.9 MICRON) LOOP INDICATE SCATTERED TO BROKEN LOW CLOUDS AFOREMENTIONED AREA WITH PSX INDICATING CEILINGS AT 4700 FT. WINDS SHOULD BE LIGHT ENOUGH LATE TONIGHT INLAND FOR POSSIBLE PATCHY FOG DEVELOPMENT AS LOW LEVEL MOISTURE CONTINUES TO INCREASE. HOWEVER...INCREASING LOW CLOUDS THEN WILL BE AN INHIBITING FACTOR. NONETHELESS...WILL MENTION PATCHY FOG LATE TONIGHT INLAND SECTIONS. WILL ADJUST 1ST PD FCST TEMPS AND CLOUD COVER WORDING FOR SW ZONES. THE REST OF PREVIOUS FORECAST PACKAGE ON TRACK. 37/46/TF .HGX...NONE. CLL EE 040/061 045/060 042 40023 IAH EE 041/060 046/061 041 40023 GLS EE 051/063 050/058 051 40-23 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SPRINGFIELD MO 844 PM CST WED JAN 5 2000 WILL UPDATE ZONES TO ADJUST CLOUD COVER. LATEST RUC/SATELLITE TREND HAS MOST OF THE LOW LEVEL MOISTURE N OF FA. WITH MID/HIGH CLD AT BEST AS SHORT WAVE ENERGY ALONG WITH RIGHT ENTRANCE OF MID LEVEL JET WORKING ACROSS THE CENTRAL U.S. THIS EVENING. MOST OF THE MOISTURE MOVES NE OF FA BY SUNRISE AS THE SYSTEM EXITS...BUT DONT SEE MUCH CHANGE IN LATEST ZONES FORECAST FOR TEMPS. JLT mo AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORMAN OK 955 AM CST THU JAN 6 2000 LOWER CLOUD DECK HAS DEVELOPED THIS MORNING ACROSS SOUTHEAST COUNTIES WHERE WEAK CONVERGENCE AND FAIR AMOUNT OF MOISTURE ADVECTION IS PRESENT AROUND 9H. MORNING RUC KEEPS RH VALUES FAIRLY HIGH DURING THE MORNING THEN BEST RH IS LIMITED TO THE EXTREME SOUTHEAST OK DURING THE AFTERNOON. RUC ALSO INDICATES BEST CHANCES FOR MID AND HIGH CLOUDS WILL BE ACROSS NORTHWEST AND NORTH CENTRAL WHERE MOSTLY CLOUDY FORECAST MAY BE NEEDED. MAY ADJUST SKY CONDITION ACROSS POTIONS OF TEXAS COUNTIES AS HIGH CLOUDS MAY HAVE A HARD TIME REACHING THIS AREA. .OUN... OK...NONE. TX...NONE. 6 ok DEEP SOUTH TEXAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE BROWNSVILLE TX 920 AM CST THU JAN 6 2000 *CLD CVR AND POPS HAVE BEEN INCREASED SUBSTANTIALLY* VLY NOW SHROUDED IN CLDS FM 3 TO 5K FT. KBRO COMP REF IDENTIFIES PATCHY SHRAS JUST OFF THE DEEP S TX COAST NOW. RUC AND NEW ETA DO SHOW MINOR PCPN POSSIBLE ALONG THE COAST TDY AS CDFNT APPROACHES AND MSTR CONVERGES TO VLY. ETA AND NGM TIMES SERIES OF PWATS SHOW VALUES INCREASING THRU 6 PM FRI...WITH MAX THEN AT 1.40 INCH. SUM H7 OMEGA PROGD FOR NOON TDY OVR BRO...WITH AGGRESSIVE UVM PROGD FOR HOU AND EASTERN TX BY 6 AM FRI...RETROGRADING DOWN THE COAST TO CRP BY FRI NOON. NCEP 24H PCPN ACCUM SHOWS RA PREDICTED ALONG THE COAST AND NRN COUNTIES BY 6 AM FRI...DRAWING 0.25 INCH ISOHYET OVR VLY FRI PM. LOW PRESSURE DEVELOPS OVR BRO WITH INVERTED TROF AND SUBSEQUENTLY INDUCED UVM NOTED BY 7 AM FRI. AVN PLACES VLY IN RANGE OF 0.01 TO 0.10 INCH EARLY FRI MRNG...WITH 0.10 INCH ISOHYET COVERING ALL OF THE VLY FM 7 AM FRI THRU 7 AM SAT. BELIEVE CLD CVR NEEDS INCREASE...ALONG WITH POPS FOR EACH PD. WILL FOLLOW AVN POPS AND TEMPS FOR THIS SYNOPTIC SITUATION...WHICH WILL ALSO BRING US IN LINE WITH ADJ CRP ZNS. WINDS WILL BACK TO THE EAST AND INCREASE ON FRI...AND WILL REFLECT THIS IN MARINE ZNS. SYN/MESO...PHILO 58/HMT...WATKINS BRO CC 072/062 065/054 062 10/20/50/50 MFE CC 074/060 065/053 060 05/20/50/50 RGC CC 075/058 065/053 059 05/20/50/50 SPI CC 070/064 066/058 063 10/20/50/50 .BRO...NONE. tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 1030 AM CST THU JAN 6 2000 FORECASTS HAVE BEEN UPDATED TO DECREASE CLOUDS AND SNOW IN CENTRAL AND SRN PORTIONS OF FORECAST AREA. DEFORMATION FIELD HAS PRODUCED LIFT TO THE SOUTHWEST WITH LIGHT SNOW MOVING INTO SW MN...HOWEVER LATEST RUC MODEL TRANSLATES QG FORCING TO THE SET WITH DIVERGENCE FIELD REMAINING OVER MOST OF FORECAST AREA. ARCTIC BOUNDARY DOES MOVE INTO NRN PORTIONS OF FORECAST AREA...BUT MOST FORCING REMAINS NORTH OF AREA. HIGH TEMPERATURES HAVE BEEN ADJUSTED FOR LACK OF CLOUD COVER. .MSP...NONE SCOTT mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 730 AM EST THU JAN 6 2000 MINOR UPDATE TO ZONES. HAVE CHANGED WORDING FOR THE SE GROUP TO PARTLY CLOUDY. CLOUDS HAVE GOTTEN INTO THIS AREA A LITTLE FASTER THAN ORIGINALLY EXPECTED...THOUGH THEY ARE HAVING A TOUGH TIME MAKING IT ANY FURTHER N THAN THE MIDLANDS...WHICH MATCHES VERY WELL WITH THE 09Z RUC. .GSP...NONE. MCAVOY sc