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 SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREAT FALLS MT 820 PM MST THU JAN 6 2000 ...WILL UPDATE STATE AND TFX ZONE FORECASTS... STL AND RADAR DATA INDICATES APPROACHING S/WV TROF BRINGING PRETTY GOOD LAYER OF MOISTURE ALOFT...ALTHO SFC OBS SHOWS VERY LITTLE REACHING THE GROUND AT THE MOMENT. NEW RUC AND ETA SHOWS SYS SPLITTING AS IT MOVES ACROSS THE DVD...WITH BEST UVV/MOISTURE MOVING ACROSS SW MT LATER TONIGHT. AS FLOW BACKS WINDS REACH 50-55 KTS AT 700 MB WITH BOI-YZU SFC PRES GRAD NEAR 26 MB AT 06Z. THRU 02Z WINDS ALONG NRN ROCKY MOUNTAIN FRONT HAVE BEEN LIGHT ...LESS THAN 40 MPH. EXPECT WINDS TO INCREASE AS S/WV MOVES THRU SRN ALTA LATER TONIGHT WITH PRE-FRONTAL GUSTS POSSIBLY APPROACHING 60 MPH. BUT WINDS OF THIS MAGNITUDE SHOULD BE SHORT LIVED SO WILL NOT ISSUE HI WIND WARNING. WILL UPDATE ZONES BETTER CHC OF SNOW ALONG THE MOUNTAINS AND FOR STRONGER WINDS LATER TONIGHT E SLOPES OF THE ROCKIES. WILL ALSO UPDATE SRN PORTIONS OF CWA FOR LOWER MIN TEMPS. UPDATES TO SFP WILL REFLECT CHANGES PER MT AFDS. EYSSAUTIER GTF 1102 HLN 1002 HVR 1102 mt AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 850 PM EST THU JAN 6 2000 LATEST SFC ANALYSIS SHOWS HIGH PRESSURE RIDGE STRETCHING SOUTHWEST ACROSS THE PIEDMONT OF THE CAROLINAS AND INTO CENTRAL GA. COASTAL TROUGH POSITIONED AS FORECAST...JUST OFF THE COAST. ISENTROPIC LIFT CAUSING BKN/OVC LAYER OF STRATOCU BASICALLY AS FAR NORTH AS THE FOOTHILLS OF OUR CWA...WHILE THE SKY REMAINS CLEAR OVER MUCH OF THE MTNS. NOTICED THAT CLOUDS HAVE BEEN MOVING MORE NORTH THAN NORTHEAST THE PAST COUPLE OF HOURS AND THE 00Z RUC PICKS UP ON THIS TREND. LOOKS LIKE AT LEAST THE ERN SIDE OF THE MTNS COULD SEE SOME CLOUDS OVERNIGHT. HOWEVER...ALL MODELS DO INDICATE THAT THE WEAK ISENT LIFT AND MOISTURE WILL BE EXITING TO THE NORTHEAST BY 12Z. PLAN TO TWEAK SKY CONDITION AND LOW TEMPS TO ADJUST FOR CLOUD COVER TRENDS. EXPECT A LARGE RANGE OF TEMPS IN THE MTNS AS HIGH ELEVATIONS ABOVE THE INVERSION WILL BE LUCKY TO GET BELOW FREEZING (BASED ON 00Z 850 MB TEMP ANALYSIS). .GSP...NONE. MOYER sc 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 AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MIDLAND TX 944 PM CST THU JAN 6 2000 WINDS IN THE GDP-DAVIS-CHISOS MTNS IN BREEZY CATEGORY AND HAVE UPDATED TO REFLECT SUCH. APPARENTLY MSL GRADIENT FAIRLY TIGHT (3MB/50NM) WITH 85H WIND AT 35KT PER 00Z RUC. .MAF... TX...NONE. NM...NONE. GPM tx TEXAS/OKLAHOMA PANHANDLES FORECAST DISCUSSION NATIONAL WEATHER SERVICE AMARILLO TX 920 PM CST THU JAN 6 2000 SFC RIDGE AXIS MOVING THROUGH OK PNHDL ATTM AS SEEN ON LATEST MSAS ANALYS AND MESONET OBS. WINDS EXPECTED TO TURN S-SW BUT REMAIN LIGHT OVERNIGHT IN WAKE OF RIDGE CROSSING FA. DPS ONCE AGAIN VERY LOW ACROSS CIMARRON COUNTY SO MAY NEED TO ADJUST LOWS DOWNWARD SOME THERE AS THEY ARE ALREADY IN FCSTD RANGE. OTHRWS LARGE SCALE SUBSIDENCE ON TOP OF PNHDLS THIS EVE EVIDENCED BY DIV-Q FIELDS ON LATEST RUC AND DESPITE RELATIVELY MOIST LAYER ON SOUNDING SKIES REMAIN CLEAR. SOME CLOUDS BEGINNING TO DEVELOP ACROSS FAR SW TX ASSCD WITH UPPER LOW DIGGING ACROSS NRN OLD MEXICO. ISENTROPIC ASCENT ALSO EXPECTED TO PRODUCE SOME LOWER CIGS IN THAT AREA BUT THIS SHOULD ALL STAY WELL S OF FA OVERNIGHT. WILL UPDATE FOR MAINLY WINDS ACROSS NRN ZNS AND REMOVE BECOMING WORDING IN S AS WE GET CLOSER TO MIDNIGHT. .AMA... TX...NONE. OK...NONE. COBB tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MIDLAND TX 839 PM CST THU JAN 6 2000 LOW CLOUD SATELLITE PRODUCT INDICATES LOW CLOUDS STILL PUSHING NW... BUT AT A SLOW RATE. 00Z RUC STILL SHOWS WIDESPREAD LOW CLOUDS BY 12Z AND HAVE UPDATED TO REFLECT A LATER ARRIVAL OF LOW CLOUDS. OTHERWISE SOME MID CLOUDS DEVELOPING S OF KELP DOWNSTREAM OF SHRTWV TROF WHICH IS LOCATED S OF KTUS. .MAF... TX...NONE. NM...NONE. GPM tx 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 BLACKSBURG VA 910 PM EST THU JAN 6 2000 SFC ANALYSIS SHOWED 31 HIGH ANCHORED ALONG VA-DE COAST...AN INVERTED COASTAL TROF TO OUR SOUTH...AND SFC LOW N OF LAKE MI WITH TRAILING COLD FRONT TO OUR WEST IN OHIO VALLEY. RNK 00Z SOUNDING WAS QUITE DRY WITH A PWAT AT 0.14 INCHES. AWIPS SATELLITE LOOP SHOWED SC (CREATED BY SOME ISENTROPIC LIFT) MOVING NORTH INTO SE PORTION OF FA. MEANWHILE...NARROW BAND OF CLOUDS ALONG THE COLD FRONT WAS SPREADING EAST. MOST OF THE CWA WAS ENJOYING CLEAR SKIES THIS EVENING. THE 23Z RUC AND MM5 SE SUPPORTED CURRENT PACKAGE FOR OVERNIGHT...AS COLD FRONT WITH LIMITED MOISTURE CONTINUES TO MARCH EAST. 18Z MESO-ETA SPINS A WEAK WAVE AND RACES COLD FRONT QUICKLY OFFSHORE...THEN ANOTHER HIGH CENTER BUILDS ACROSS FA BEHIND THE FRONT BY FRIDAY AFTERNOON. INTERESTING TO NOTE THAT AT 250MB A 140KT JET PIVOTS EAST ACROSS FA AROUND 12Z. EARLIER RUNS OF AVN/NGM AT 12Z SHOWED LIFT MAINLY CONFINED TO 700MB AND ABOVE. CURRENT ZONES ON TRACK...WILL MAKE ONLY A FEW MINOR CHANGES TONIGHT. ZONES WILL BE OUT AROUND 935 PM. .RNK VA...NONE. WV...NONE. NC...NONE. KK va SOUTH CENTRAL AND SOUTHEAST COLORADO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO 312 AM MST FRI JAN 7 2000 BASIC UPPER PATTERN REMAINS...WITH FAST WLY/NWLY FLOW ACROSS THE NRN U.S. AND OCCASIONAL S/W TROUGHS ZIPPING BY. THE NEXT SHORTWAVE IS MOVING ACROSS THE NRN GREAT BASIN TONIGHT. THE ETA BRINGS A BROAD AREA OF LARGE SCALE ASCENT (DIAGNOSED BY THE 500-300 MB Q CONVERGENCE) ACROSS THE AREA...MAINLY FROM 2100 UTC TO 0900 UTC SAT...KEEPING THE BULK OF THE ASCENT NEAR THE FOUR CORNERS REGION. A QUALITATIVE COMPARISON OF THE 0600 UTC RUC FORECAST WITH IR IMAGERY SUGGESTS THAT THE ETA IS ON TRACK WITH THIS FEATURE. THUS...A CHANCE/SLIGHT CHANCE OF SNOW SHOWERS SHOULD SUFFICE FOR THE MOUNTAINS TONIGHT. THE SHORTWAVE THEN TRACKS ALONG THE SRN PORTION OF THE FORECAST AREA...NOT LEAVING THE SOUTHEAST PLAINS UNTIL SOMETIME SATURDAY MORNING. HOWEVER...THE AIRMASS SHOULD BE TOO DRY TO GENERATE PRECIPITATION ON THE PLAINS...AND I WILL CONTINUE WITH A DRY FORECAST FOR THIS AREA. OTHERWISE...A LEE TROUGH SETS UP TODAY... WHICH SHOULD ALLOW FOR WARMER TEMPERATURES ON THE PLAINS TODAY... ASSUMING THE INVERSION CAN BE BROKEN. 700 MB TEMPS INCREASE 3-6 DEG C. TO ALLOW FOR WARMING IN THE MOUNTAINS AS WELL. ON SATURDAY...ANOTHER SHORTWAVE WILL BE APPROACHING THE AREA... PROBABLY FASTER THAN THE MODELS ARE SUGGESTING. THIS WILL ALLOW FOR A GOOD SHOT AT SNOW IN THE CNTRL MOUNTAINS. A LEE TROUGH WILL CONTINUE AHEAD OF THIS WAVE...KEEPING THE PLAINS IN RELATIVELY WARM DOWNSLOPE FLOW. THE "WINDY" WORDING FOR MTN ZONES SATURDAY STILL LOOKS GOOD AS THE UPPER JET SAGS SOUTHWARD. EXTENDED...CROSS SECTIONS OF GRIDDED DATA AND CONCEPTUAL MODELS SUGGEST THE POTENTIAL FOR AN AMPLIFIED MOUNTAIN WAVE EARLY SUNDAY... WHICH COULD SPREAD WINDY CONDITIONS FROM THE MOUNTAINS TO THE LOWER ELEVATIONS. OTHERWISE...A SEEMINGLY ENDLESS SERIES OF SHORTWAVES CONTINUE THEIR MARCH ACROSS THE FORECAST AREA THROUGH NW FLOW ALOFT...DRIVEN BY A RELATIVELY STRONG UPPER JET. THIS SHOULD MAKE FOR SHORTWAVES THAT ARE DIFFICULT OR IMPOSSIBLE TO ACCURATELY TIME... AND FOR PERIODIC WINDY CONDITIONS. THE CURRENT EXTENDED FORECAST HAS GENERALLY DRY...MILD AND OCCASIONALLY WINDY CONDITIONS IN THE LOWER ELEVATIONS...WINDY IN THE MOUNTAINS AND A CHANCE OF SNOW EACH DAY IN THE CNTRL MOUNTAINS... WHICH IS ABOUT ALL THAT CAN BE SAID FOR THIS PATTERN. THUS...I WILL MAKE NO CHANGES TO THE EXTENDED PORTION OF THE FORECAST PACKAGE. .PUB...NONE. HAYNES co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PEACHTREE CITY GA 210 AM EST FRI JAN 7 2000 HOW LONG WILL THE CLOUDS LAST? CLOUDINESS HAS NOT BEEN HANDELED BY MODELS WELL SINCE THURSDAY AM, STILL NOT THOUGH RUC GIVING IT A TRY. A FICTIOUS FRONT ACROSS THE TENNESSEE VALLEY SUPPOSEDLY "JUMPS" INTO THE GULF BETWEEN 06 AND 12Z. ON THE ETA THIS SUPPOSEDLY CAUSES THE WINDS IN THE LOWER LAYERS TO "CHANGE" FROM VARIABLE TO ALL NORTH AT 10KT. ANYWAY, TO REALITY. WEAK WEDGE OVER SOUTHEAST REPLACED BY HIGH OVER PLAINS THAT MOVES ACROSS THE STATE TODAY/TONIGHT TO OFF THE COAST BY SATURDAY PM. THIS CAUSES FLOW TO VEER TO EAST AT SURFACE TO SOUTHWEST +/>850MB, WHICH OPENS UP GULF AND BRINGS INCREASING MOISTURE NOW OVER TEXAS AND LOWER MS VALLEY EAST TO OVER GA SATURDAY. ALOFT FLOW REMAINS WSW WITH WEAK VORT/WAVE MOVING ACROSS OH VALLEY TODAY AND ANOTHER SATURDAY. AS THE SURFACE "FRONT" MOVES THRU GA AND HIGH BUILDS IN FROM WEST, WILL SEE CLEARING FROM WEST TODAY DUE DRYING, BUT WILL BE AFTERNOON BEFORE EAST SEES SUN. TONIGHT SHOULD BE MOSTLY CLEAR EXCEPT FOR A FEW CLOUDS SOUTHEAST. THEN SATURDAY AS HIGH MOVES OFFSHORE AND FLOW ABOVE SURFACE BECOMES SOUTHWEST, OVER-RUNNING DEVELOPS AND CLOUDS WILL BE ON THE INCREASE FROM WEST, LEADING TO SCATTERED RAIN EVENT SATURDAY NIGHT, AS ALREADY ADVERTISED. FELL PRECIP WILL START AS STRATIFORM VS CONVECTIVE SINCE THIS WILL START AS OVER RUNNING EVENT. BOUNDAARY IS OLD FRONT THAT IS NOW ALONG GULF AND WILL ACCORDING TO MODELS WILL BE REINFORCED AS "FRONT" MOVES THRU GA TODAY. LITTLE CHANGE IN THICKNESS TODAY WITH WEAK WAA SATURDAY. HOWEVER DUE INCREASING CLOUDS SUN LIMITED AND SHOULD BE A LITTLE COOLER. WILL COMPROMISE ON GUIDANCE EXCEPT PREFER COOLER FAN FOR LOWS. ATL 59/35/54 00- AHN 57/32/52 000 RMG 57/26/53 00- CSG 64/36/55 00- MCN 62/33/56 000 .ATL...NONE ga AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CARIBOU ME 922 PM EST THU JAN 6 2000 SYNOPSIS: A WEAK TROUGH OF LOW PRESSURE AND AN ASSOCIATED COLD FRONT WILL CROSS THE AREA FRIDAY. THIS SYSTEM WILL SET OFF SOME LIGHT SNOW AND SNOW SHOWERS FOR NORTHERN AREAS WITH SOME RAIN SHOWERS FOR DOWNEAST AND THE COAST. HIGH PRESSURE CENTERED OVER THE SOUTHEASTERN UNITED STATES WILL RIDGE OVER THE AREA SATURDAY INTO EARLY SUNDAY. TECHNICAL DISCUSSION: 00Z SURFACE MAP SHOWED LOW PRES NEAR JAMES BAY WITH WARM FRONT EXTENDING SOUTHEAST THROUGH SRN QUEBEC PROVINCE INTO SRN ME. COLD FRONT TRAILING FROM THIS SYSTEM ACROSS WESTERN MI. LATEST RUC MODEL SHOWS TEMPS NEARLY STEADY OR SLOWING RISING OVERNIGHT MOST AREAS. TEMP ALREADY UP TO 36 DEG F AT BHB THIS HOUR. WILL TWEAK TEMPS A BIT WITH THIS UPDATE. EXCEPT FOR A FEW COSMETIC CHANGES TO SKY CONDITION WILL BASICALLY LEAVE CURRENT PACKAGE AS IS. COASTAL WATERS...WILL MAINTAIN THE SMALL CRAFT ADVISORY. MDRM1 SUSTAINED AT 26 KT ATTM. RUC MDL 925 MB WINDS SUGGEST THIS TREND WILL CONTINUE. .CAR...SCA. TD me AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1005 PM EST THU JAN 6 2000 LES IS THE FCST CONCERN FOR THE OVERNIGHT. WV IMAGERY SHOWS ONE SHORTWAVE S OF JAMES BAY AND ANOTHER MOVING E ACROSS WI. AT THE SFC...LOW PRESSURE WAS OVER JAMES BAY WITH A TROF TRAILING SW ACROSS LK SUPERIOR/W FA. WIND SHIFTING FROM W TO NW NO DOUBT BEGINNING TO CREATE DISORGANIZATION OF WELL DEVELOPED WIND PARALLEL LES BANDS THAT WERE SEEN OVER W LK SUPERIOR ON VIS SATELLITE IMAGES LATE AFTN. OVER NCNTRL FA...W WIND FLOW CONTINUES AND KMQT RADAR SHOWS LES BANDS REMAINING OFFSHORE. ONLY INTMT -SN/FLURRIES BEING OBSERVED OVER LAND. 18Z ETA/00Z RUC SHOW TROF SWINGING THRU REMAINDER OF FA OVERNIGHT. EXPECT LOW-LEVEL CONV ALONG TROF AXIS TO SET UP A SHORT PERIOD OF DECENT SNOW ALONG WIND SHIFT AS IT PUSHES SE ACROSS NCNTRL FA. E-W BAND SHOWN ON KMQT RADAR S OF STANNARD ROCK WILL LIKELY BECOME BAND THAT DRIFTS S INTO FA AS IT IS JUST AHEAD OF WIND SHIFT. THIS BAND LIKELY CREATED THE SHORT PERIOD OF +SNSH AT KCMX AROUND 01Z. NW-SE WIND PARALLEL BANDS SHOULD THEN BECOME ESTABLISHED A SHORT TIME AFTER WIND SHIFT...AND THE FOCUS OF THESE WILL BE ACROSS LUCE AND MAINLY E 1/2 OF ALGER COUNTIES. 00Z RUC SHOWING NICE ALIGNMENT OF 950-850MB WIND AFTER 09Z...AND WOULD EXPECT BEST LES TO OCCUR IN THE 09Z-14Z TIME FRAME. AFTER 14Z...NOTABLE DRYING SHOWN IN LOW-LEVELS AND WIND FLOW BECOMES INCREASINGLY ANTICYCLONIC. GIVEN SHORT DURATION...ACCUMULATIONS WILL BE LIMITED. WITH DELTA-T OF 20C... INVERSION OF ABOUT 5K FT PER 00Z RUC AND ROUGHLY 6HR WINDOW... GIVES POTENTIAL OF 2-4 INCHES. CURRENT FCST OF 3-6 LIKELY TOO HIGH AND WILL TRIM BACK TO 2-5. GUSTY NW WIND AFTER TROF PASSAGE WILL MAKE BLSN A PROBLEM...AND ADVISORY WILL REMAIN UP. ACROSS THE KEWEENAW...SHORT FETCH (WITH NW FLOW AS OPPOSED TO W)... DRYING EVIDENCED ON IR SAT PICS UPSTREAM...AND FALLING INVERSION SHOWN ON KINL SOUNDING WILL RESULT IN A CONTINUED DIMINISHING TREND. ADVISORY WILL REMAIN UP THOUGH...MAINLY FOR BLSN. EXPECT AN ADDITIONAL 1-2 INCHES THERE. ACROSS REST OF FA...NOTHING MORE THAN FLURRIES/-SN OVERNIGHT. SHORTWAVE MOVING THRU WI WILL POSE NO PROBLEMS FOR FA AS REGIONAL RADARS/SFC OBS SHOWING LITTLE SNOW NEAR/UPSTREAM. EXPECT CLEARING TO BEGIN IN SW COUNTIES...AND THIS WILL ALLOW TEMPS TO FALL BELOW CURRENT FCST. WILL DROP MINS AND OPEN UP RANGE A BIT THERE. COORD WITH APX...THANKS. .MQT...LAKE EFFECT SNOW AND BLOWING SNOW ADVISORY ONTONAGON... HOUGHTON...KEWEENAW COUNTIES OVERNIGHT. LAKE EFFECT SNOW AND BLOWING SNOW ADVISORY OVERNIGHT AND FRI MORNING FOR ALGER/LUCE COUNTIES. GALE WARNING E LK SUPERIOR. ROLFSON mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 940 PM EST THU JAN 6 2000 GOING ZONE PACKAGE LOOKS OKAY... AND WILL NOT MAKE ANY MAJOR CHANGES. THE MOSTLY CLOUDY FORECAST FOR OVERNIGHT SHOULD WORK OUT FINE AS MOST LOCATIONS HAVE CONSIDERABLE CLOUDS AT THIS POINT... AND ADDITIONAL CLOUD COVER WILL ARRIVE OVERNIGHT AS THE SHORTWAVE SWINGS THROUGH. WILL ONLY MAKE MINOR MODIFICATIONS TO ACCUMULATION FORECAST... AND STICK WITH GENERALLY LIGHT AMOUNTS. THERE IS LITTLE DOUBT THAT THE AREA OF PCPN WITH THE SHORTWAVE WILL INCREASE AS IT MOVES ACROSS THE LAKE. HOWEVER... THE NARROW TIME WINDOW SHOULD LIMIT ACCUMULATIONS. FORECAST SOUNDINGS FROM THE 18Z ETA AND LATEST RUC INDICATE THE WINDOW OF BEST SNOWFALL POTENTIAL WILL BE FROM 07Z-11Z. THE SHORTWAVE WILL HELP ERODE THE INVERSION DURING THIS TIME-FRAME... AND DECENT MOISTURE WILL BE PRESENT THROUGH 10K FEET. WIND FLOW WITHIN THE CBL WILL BE AROUND 290 DEGREES... SO THE BEST SNOW SHOULD BE IN OTTAWA... ALLEGAN... VAN BUREN... AND KALAMAZOO COUNTIES. DNVA MOVES IN AFTER 11Z... WITH SUBSIDENCE DRYING THINGS OUT AND LOWERING THE INVERSION TO BETWEEN 3K AND 4K FEET BY 18Z. WILL BUMP FORECAST LOWS UP SLIGHTLY TO LINE UP BETTER WITH CURRENT TRENDS AND LATEST GUIDANCE FROM THE RUC AND LAMP. ZONES WILL BE OUT BY 1000 PM. TRH .GRR...NONE. mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 930 PM EST THU JAN 6 2000 HAVE BEEN MONITORING THE PROGRESS OF THE SHORT WAVE MOVING INTO WISCONSIN THIS EVENING. IT HAS GENERATED A DECENT AMOUNT OF FLURRIES AND A FEW PATCHES OF SNOW, DESPITE COMING EAST WITH COLD ADVECTION IN THE LOW LEVELS. A CLOSER LOOK AT THE UPPER AIR AND MODEL DATA SHOWS SOME MOISTURE POOLING ALONG THE 850 FRONT AND AIDING THE PRECIP DEVELOPMENT. FOR NOW, AS THIS SYSTEM MOVES EAST, WILL MAINTAIN FLURRIES IN THE FORECAST FOR THE OVERNIGHT PERIOD, AND SCATTERED LIGHT SNOW SHOWERS IN THE FLINT...OWOSSO...HOWELL AREA. A BOOST FROM LAKE MICHIGAN STILL LOOKS LIKE A GOOD POSSIBILITY. THE LATEST FORECAST SOUNDINGS FROM THE MESOETA AND RUC SHOW THE INVERSION JUMPING UP TO AROUND 6 KFT OVER THE SOUTHERN PART OF THE LAKE AS THE SHORT WAVE MOVES OVERHEAD. THERE WILL ALSO BE A GOOD SW TO NE CONVERGENCE ZONE SETTING UP WITH THE FRONT AROUND 09Z IN THE LEE OF THE LAKE. LIMITING FACTOR WILL BE INSTABILITY WITH LAKE TO 850 DELTA-T ONLY GETTING TO AROUND -17C BY 09Z. DESPITE THIS, WITH LIFT ON THE SYNOPTIC SCALE, STILL THINK WE COULD SEE A FLARE UP OF LIGHT SNOW WITH THE BEST CHANCE BEING IN THAT AREA MENTIONED ABOVE. FORECAST UPDATE WILL FRESHEN THE TREND ON CLOUDS AND FLURRIES/SNOW SHOWERS. LOW TEMPS LOOK GOOD AS THE SURFACE FRONT MAKES IT THRU BEFORE SUNRISE. .DTX...NONE. BT mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 330 AM CST FRI JAN 7 2000 HIGH CLOUDS INCREASING NICELY AHEAD OF NEXT MID LEVEL TROUGH. CLOUDS LINING UP NICELY WITH RUC 60 PERCENT LN WHICH SWEEPS ACRS NRN TWO THIRDS OF MN ZFA THIS MRNG. MID LEVEL MOISTURE LAGGING A BIT BEHIND. TEMPS STARTING OUT THIS MORNING...IRONICALLY IN THOSE AREAS WITH THE LEAST AMOUNT OF SNOWDEPTH. NUMERICAL MODELS IN GOOD AGREEMENT ON CARRYING WEAK S/W ACRS NRN MN TODAY...HOWEVER NOT ON EXACT TRACK. SECOND UPSTREAM WAVE ALSO BEING PLACED FARTHER NORTH FOR TNGT/EARLY SAT. HENCE MAIN QG FORCING TODAY AS A RESULT OF WARM AIR ADVECTION. Q VECTOR CONVERGENCE IMPRESSIVE FROM 800-700 MB OVER NW/WEST CENTRAL MN BY 18Z...HOWEVER MOISTURE MUCH MORE LIMITED THAN LAST WAA EVENT. AREA OF CONVERGENCE PROCEEDS EWD AND CLIPS NRN WI ZFA THIS AFTN. 290 THETA SFC SHOWS CONDENSATION PRES DEFICITS DECREASING TO NR 50 MB BY 18Z WITH 40 TO 45 KT UPGLIDE...HOWEVER PRES SFCS ALSO INCREASING...DIMINISHING VV. PER COORD WITH FGF/DLH...WL KEEP SML POPS FOR -SN IN NRN AREAS THIS AFTN. MODEL SOUNDINGS SHOW MID LEVEL WARMING...BUT STILL MOSTLY ICE CRYSTALS BEING GENERATED AT MID LEVELS SO WL NOT MENTION -FZDZ AT THIS TIME. PACIFIC TROF/WRMFNT ABT ON WRN BDR BY 00Z AND THEN PROCEEDS TO SWEEP THRU MN TNGT. LOW LEVEL CONVERGENCE MINIMAL AS HIGHER SFC DEWPTS RMN SOUTH OF AREA. HENCE NOT EXPCD ANY WIDESPREAD ST FIELD TO DEVELOP AND MIXING SHOULD RETARD MUCH FOG FORMATION. DRY SWLY FLOW BETWEEN WX SYSTEMS SHOULD RESULT IN PLEASANT WX ON SAT WITH SOME MELTING AS 850 TEMPS INCREASE TO ZERO TO -5 RANGE. AGREE MORE WITH AVN/NGM COOLER TEMP GUIDANCE FOR TODAY AS BULK OF WARMING RIDES OVR COLD DOME IN PLACE. .MSP...NONE KAVINSKY mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 214 AM EST FRI JAN 7 2000 88D AND SFC REPORTS (IE GOING OUTSIDE) INDICATE THAT SOME PCPN HAS DEVELOPED OVER THE UPSTATE AND THE NC PIEDMONT THIS MORNING. IT IS HARD TO PIN THIS ON ANY ONE FEATURE...THOUGH DELTA-T/S WERE RUNNING AROUND 19 DEGREES FROM H7 TO H5 BASED ON 00Z HAND ANALYSIS. PCPN LOOKS CONVECTIVE IN NATURE AND EXPECT SPRINKLES AND LIGHT SHOWERS TO CONTINUE FOR A FEW MORE HOURS UNTIL FLOW BEGINS TO TURN DOWNGLIDE AROUND 9Z OR SO. WL HANDLE ALL THIS IN THE SHORT TERM FORECAST FOR NOW. OTHER THAN THE ONGOING SPRINKLES...NOT A NOT TO WORRY ABOUT THIS PACKAGE. PRIMARY FORECAST CONCERNS ARE HOW RAPIDLY WE CLEAR THIS MORNING...AND POSSIBLE P-TYPE PROBLEM IN THE 5TH PERIOD. RAPIDLY MOVING MINOR WAVE EMBEDDED IN NRN CONUS ZONAL FLOW IS INTO NEW ENGLAND BY THIS AFTN. FRONT IS HARD TO FIND...BUT MODELS ALL TURN THE FLOW W AND THEN NW BY MID-MORNING. H8 TEMPS BARELY FALL TO 0 DEG C OVER THE NRN MTNS. COUPLED WITH DOWNGLIDE...HIGHS OF 55 TO 60 MOST NON MOUNTAIN AREAS LOOK GOOD...WHICH IS RIGHT ON TRACK W/CURRENT ZONES. 09Z RUC 290K ISENTROPIC SFC SCOURS THE CLOUDS OUT OF ALL BUT THE ERN MOST ZONES BY 15Z. ATTM FOG PRODUCT SHOWS LOW STUFF BANKED PRETTY MUCH ALONG THE ERN ESCARPMENT OF THE BLUE RIDGE. THIS MATCHES THE RUC VERY WELL AND WILL FOLLOW ITS TIMING AND INCLUDE SOME MORNING CLOUDS...BUT HAVE EVERYONE BECOME SUNNY BY LATE MORNING OR NOON. CLEAR TNGT AS PACIFIC HIGH SETTLES ACROSS THE CWA...WITH GRADUAL INCREASE IN HIGH CLOUDS SAT AS ZONAL FLOW BEGINS TO BRING MID AND HIGH CLOUDS INTO THE REGION. SRN STREAM CUT-OFF LOW EJECTS AND APPROACHES THE AREA SUN MORNING. LOOKS LIKE MOST OF THE LIFT AND DEEP MOISTURE DON/T GET INTO THE MTNS TIL AFTER SUNRISE. MADE NO CHANGES TO EXTENDED AND WL LET DAY SHIFT TRY TO PIN DOWN ONSET OF PCPN. PRELIMINARY NUMBERS: AVL 52/22/47 000 CLT 59/27/49 -00 GSP 60/28/50 000 .GSP...NONE. MCAVOY sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LA CROSSE WI 910 PM CST THU JAN 06 2000 RATHER VIGOROUS UPPER LEVEL WAVE MOVING QUICKLY ACROSS MINNESOTA AND WESTERN WISCONSIN THIS EVENING. SKIES ARE ALREADY CLEARING ACROSS MINNESOTA IN ITS WAKE. RUC AND MESO-ETA LOW LEVEL Q-VECTOR FIELDS CORRESPOND QUITE WELL WITH ON-GOING SNOW SHOWERS. THIS AREA OF CONVERGENCE MOVES QUICKLY EASTWARD OVERNIGHT AS CLEARING SKIES MOVE IN FROM THE WEST. SOME OF THE HEAVIER SNOW BANDS HAD DROPPED UP TO 1/2 INCH IN A FEW LOCATIONS. WILL UPDATE ZONES TO REFLECT SNOW SHOWERS COMING TO AN END WITH CLEARING TREND. .LSE...NONE. RABERDING wi EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE TULSA OK 950 AM CST FRI JAN 7 2000 NO UPDATE PACKAGE WILL BE ISSUED LATE THIS MORNING. EARLY MORNING FORECAST LOOKS REASONABLE. 12Z H8 TEMPS ARE NEAR OR JUST SLIGHTLY BELOW THOSE OF YESTERDAY...BUT THIS WILL BE COUNTED BY THE LACK OF MID TO HIGH LEVEL CLOUDS TODAY. GLIMPSE OF THE RUC INDICATES A TIGHTER MOISTURE GRADIENT FROM SOUTH TO NORTH TONIGHT. THERE MAY BE A SHARPER CUT OFF EDGE TO THE RAIN AREA EXPECTED OVERNIGHT. HOWEVER...WILL WAIT UNTIL THIS AFTERNOON AND EXAMINE OTHER MODELS BEFORE MAKING ANY CHANGES FOR TONIGHT. FCSTID = 11 .TUL... AR...NONE. OK...NONE. ok AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORMAN OK 923 PM CST THU JAN 6 2000 ONLY WEAK LIFT HAS BEEN NEEDED TO PRODUCE CLOUDS IN THE 1000-850 MB LAYER ACROSS PORTIONS OF SOUTHEAST OKLAHOMA WHERE THE ATMOSPHERE IS QUITE MOIST. 12Z GUIDANCE AND RECENT RUC2 PROGS APPEAR TO HAVE A GOOD HANDLE ON THE EVOLUTION OF CLOUDS HERE OVERNIGHT. EXPECT THE 1000-850 MB CONVERGENCE ZONE TO CONTINUE TO WEAKEN AND SHIFT SOUTHWARD INTO TEXAS OVERNIGHT AS THE SUBSIDENCE REGION ASSOCIATED WITH THE CENTRAL PLAINS UPPER LEVEL TROUGH BUILDS A SURFACE HIGH INTO THE FORECAST AREA. HAVE CURRENTLY WORDED PORTIONS OF SOUTHEAST OKLAHOMA AS MOSTLY CLOUDY THIS EVENING...AND DECREASING CLOUDINESS AFTER MIDNIGHT. BELIEVE THIS TREND IS STILL ACCURATE AND WILL CONTINUE IT FOR NOW. OTHERWISE SURFACE WIND SPEEDS WILL DECREASE MOST NOTICEABLY ACROSS NORTHERN OKLAHOMA OVERNIGHT DUE TO CLOSER PROXIMITY TO CORE OF SURFACE HIGH...SUPPORTING GOOD RADIATIONAL COOLING CONDITIONS. WILL CONTINUE WITH COLDEST TEMPERATURES ACROSS THIS AREA OVERNIGHT. .OUN... OK...NONE. TX...NONE. JAMES ok AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CLEVELAND OH 300 PM EST FRI JAN 7 2000 QUITE A CHANGEABLE AFTN ACRS NRN OHIO. DESPITE STG NVA...DOWNWARD MOTION AND CONDITIONAL INSTBY WITH RESPECT TO THE LAKE...LES SNOW DVLPD AND DROPPED UP TO 2 INCHES EAST OF KCLE. NGM/ETA AND RUC SHOW COLDEST AIR AT 850 ACRS FA ATTM WITH WARM ADVN TO BGN QUICKLY THIS EVG AND CONT OVRNGT WHICH SHOULD BRING AN END TO LES. WL CONT SNOW INTO EVG AND MNTN TOTAL ACCUM OF 1 TO LOCALLY 3 INCHES. OTRW CLDS ACRS FA CONVECTIVE AND SHOULD DSIPT THRU THE EVG AND ERY TNGT AS DRY AIR AND HIGH PRES NOSE IN FM THE SOUTH. DRY AIR TO RMN ACRS FA INTO SATURDAY HWVR MSTR RETURNS QUICKLY SAT NGT AND SUNDAY IN ADVANCE OF VORT MOVING OUT OF THE SRN PLAINS. NGM ISOTHERMS REMAIN PACKED IN THE LOWER TN VLY SAT NGT INTO SUNDAY WHLIE THE ETA HAD PACKING FURTHER NORTH ACRS THE SRN OH VLY. EITHER WAY BEST LIFT SHOULD BE TO OUR SOUTH BUT AVN SHOWS VORT SWINGING ACRS FA WHICH WL LKLY DRAG PCPN FURTHER NORTH DURG THE DAY. WL CARRY SMALL CHC THRU SAT NIGHT AND BOOST TO HIGH CHC ON SUNDAY. CLE...NONE. TK oh