AREA FORECAST DISCUSSION...CORRECTED NATIONAL WEATHER SERVICE GOODLAND KS 234 PM MST TUE FEB 1 2005 .DISCUSSION...FORECAST CHALLENGES INCLUDE FOG POTENTIAL TONIGHT FOR PARTS OF THE FORECAST AREA THEN TEMPERATURES THROUGH THE WEEKEND. LATEST 19Z SURFACE MAP ANALYSIS SHOWED PERSISTENT SURFACE HIGH PRESSURE RIDGE TO OUR EAST CENTERED OVER THE GREAT LAKES WITH ANOTHER HIGH PRESSURE RIDGE OVER THE PACIFIC NORTHWEST. IR AND WATER VAPOR SATELLITE IMAGERY SHOWED ANTICYCLONIC FLOW AROUND AMPLIFIED UPPER LEVEL RIDGE OVER THE WEST COAST STILL ANTICIPATED TO BUILD SLOWLY EASTWARD OVER THE CENTRAL HIGH PLAINS INTO THE WEEKEND. AS FOR THE SHORT TERM FORECAST THROUGH FRIDAY NOT A LOT OF CHANGES TO PREVIOUS FORECAST AS WEATHER PATTERN HERE IN THE CENTRAL HIGH PLAINS SLOW TO CHANGE. STRONG 250 MB JET STILL LIES TO OUR SOUTH AND SOUTHEAST ACROSS TEXAS INTO OKLAHOMA BUT SHOWS SIGNS OF SLIDING SLOWLY EAST. FOR TONIGHT LOOKING AT THE LATEST RUC II AND ETA MODEL DATA SHOWS NOT AS MUCH RH IN THE ATMOSPHERE AS PREVIOUS NIGHTS. STILL SOME LOW LEVEL MOISTURE AROUND THOUGH AND WITH LIGHT NORTH TO NORTHWEST WINDS MAY STILL SEE A REPEAT OF THIS MORINING WHERE AREAS OF FOG DEVELOPED ESPECIALLY FROM GOODLAND EASTWARD. WILL MENTION PATCHY FOG FOR THE BORDERING KANSAS ZONES WITH AREAS OF FOG FOR THE EASTERN ZONES FROM THE MCCOOK TO GOVE AREAS. WILL GO CLOSE TO GUIDANCE FOR TEMPERATURES IN THE LOW TO MIDDLE 20S. WILL SEE HIGH TEMPERATURES WARM A LITTLE MORE EACH DAY TUESDAY THROUGH FRIDAY AS THE UPPER LEVEL RIDGE BUILDS INTO THE AREA. WILL ALSO SEE MORE SUNSHINE AND DOWN SLOPE WINDS WHICH WILL ALSO HELP IN THE WARMING PROCESS. WILL GO CLOSE TO GUIDANCE FOR HIGH TEMPERATURES WEDNESDAY RISING TO AROUND 50 AND THEN GRADUALLY WARMING TO AROUND 60 BY FRIDAY. AS FOR THE EXTENDED FORECAST PERIOD (SATURDAY THROUGH TUESDAY) GFS AND ECMWF MODELS SEEM TO BE IN A LITTLE MORE AGREEMENT WITH REGARD TO COLDER AIR MOVING INTO THE REGION BEHIND COLD FRONTAL PASSAGE OVER THE WEEKEND. ONLY SIGNIFICANT CHANGES MADE HERE WERE TO INTRODUCE SLIGHT CHANCE POPS FOR LIGHT PRECIPITATION BEGINNING LATE SATURDAY THROUGH SUNDAY NIGHT AS COLD FRONT AND COLDER AIR MOVE INTO REGION. ALSO MODELS SHOW RATHER STRONG SHORTWAVE MOVING THROUGH THE REGION DURING THE DAY SUNDAY. MOISTURE FIELDS SHOW SOME LOW AND MID LEVEL MOISTURE AVAILABLE AND DYNAMICS. THIS WAS THE REASONING FOR INSERTING SLIGHT CHANCE POPS FOR LIGHT SNOW FOR SUNDAY AND SUNDAY NIGHT. BY MONDAY COLD HIGH PRESSURE RIDGE WILL BUILD INTO THE REGION WHICH WILL BEGIN ANOTHER PERIOD OF DRY WEATHER. HAVE GONE WITH LITTLE COOLER TEMPERATURES FOR HIGHS ON MONDAY AND TUESDAY WITH HIGHS IN THE MID 30S TO LOW 40S. && .GLD WATCHES/WARNINGS/ADVISORIES... .KS...NONE. .NE...NONE. .CO...NONE. && $$ LAMMERS ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 234 PM MST TUE FEB 1 2005 .DISCUSSION...FORECAST CHALLENGES INCLUDE FOG POTENTIAL TONIGHT FOR PARTS OF THE FORECAST AREA THEN TEMPERATURES THROUGH THE WEEKEND. LATEST 19Z SURFACE MAP ANAL SHOWED PERSISTENT SURFACE HIGH PRESSURE RIDGE TO OUR EAST CENTERED OVER THE GREAT LAKES WITH ANOTHER HIGH PRESSURE RIDGE OVER THE PACIFIC NORTHWEST. IR AND WATER VAPOR SATELLITE IMAGERY SHOWED ANTICYCLONIC FLOW AROUND AMPLIFIED UPPER LEVEL RIDGE OVER THE WEST COAST STILL ANTICIPATED TO BUILD SLOWLY EASTWARD OVER THE CENTRAL HIGH PLAINS INTO THE WEEKEND. AS FOR THE SHORT TERM FORECAST THROUGH FRIDAY NOT A LOT OF CHANGES TO PREVIOUS FORECAST AS WEATHER PATTERN HERE IN THE CENTRAL HIGH PLAINS SLOW TO CHANGE. STRONG 250 MB JET STILL LIES TO OUR SOUTH AND SOUTHEAST ACROSS TEXAS INTO OKLAHO BUT SHOWS SIGNS OF SLIDING SLOWLY EAST. FOR TONIGHT LOOKING AT THE LATEST RUC II AND ETA MODEL DATA SHOWS NOT AS MUCH RH IN THE ATMOSPHERE AS PREVIOUS NIGHTS. STILL SOME LOW LEVEL MOISTURE AROUND THOUGH AND WITH LIGHT NORTH TO NORTHWEST WINDS MAY STILL SEE A REPEAT OF THIS MORINING WHERE AREAS OF FOG DEVELOPED ESPECIALLY FROM GOODLAND EASTWARD. WILL MENTION PATCHY FOG FOR THE BORDERING KANSAS ZONES WITH AREAS OF FOG FOR THE EASTERN ZONES FROM THE MCCOOK TO GOVE AREAS. WILL GO CLOSE TO GUIDANCE FOR TEMPERATURES IN THE LOW TO MIDDLE 20S. WILL SEE HIGH TEMPERATURES WARM A LITTLE MORE EACH DAY TUESDAY THROUGH FRIDAY AS THE UPPER LEVEL RIDGE BUILDS INTO THE AREA. WILL ALSO SEE MORE SUNSHINE AND DOWN SLOPE WINDS WHICH WILL ALSO HELP IN THE WARMING PROCESS. WILL GO CLOSE TO GUIDANCE FOR HIGH TEMPERATURES WEDNESDAY RISING TO AROUND 50 AND THEN GRADUALLY WARMING TO AROUND 60 BY FRIDAY. AS FOR THE EXTENDED FORECAST PERIOD (SATURDAY THROUGH TUESDAY) GFS AND ECMWF MODELS SEEM TO BE IN A LITTLE MORE AGREEMENT WITH REGARD TO COLDER AIR MOVING INTO THE REGION BEHIND COLD FRONTAL PASSAGE OVER THE WEEKEND. ONLY SIGNIFICANT CHANGES MADE HERE WERE TO INTRODUCE SLIGHT CHANCE POPS FOR LIGHT PRECIPITATION BEGINNING LATE SATURDAY THROUGH SUNDAY NIGHT AS COLD FRONT AND COLDER AIR MOVE INTO REGION. ALSO MODELS SHOW RATHER STRONG SHORTWAVE MOVING THROUGH THE REGION DURING THE DAY SUNDAY. MOISTURE FIELDS SHOW SOME LOW AND MID LEVEL MOISTURE AVAILABLE AND DYNAMICS. THIS WAS THE REASONING FOR INSERTING SLIGHT CHANCE POPS FOR LIGHT SNOW FOR SUNDAY AND SUNDAY NIGHT. BY MONDAY COLD HIGH PRESSURE RIDGE WILL BUILD INTO THE REGION WHICH WILL BEGIN ANOTHER PERIOD OF DRY WEATHER. HAVE GONE WITH LITTLE COOLER TEMPERATURES FOR HIGHS ON MONDAY AND TUESDAY WITH HIGHS IN THE MID 30S TO LOW 40S. && .GLD WATCHES/WARNINGS/ADVISORIES... .KS...NONE. .NE...NONE. .CO...NONE. && $$ LAMMERS ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 1026 AM MST TUE FEB 1 2005 .UPDATE...LOW CLOUDS WILL BE SLOW TO ERODE TODAY. SKIES WERE GENERALLY SUNNY OVER EASTERN COLORADO THIS MORNING...AND CLOUDY OVER THE REST OF THE TRI STATE. A NARROW BAND OF DENSE FOG FORMED ALONG THE MIXING ZONE BETWEEN THE CLEAR AND CLOUDY AIR. MOST OF THAT FOG HAS LIFTED NOW...SO WILL DROP THE FOG OUT OF THE FORECAST FOR NOW...AND BRING IT BACK IN LATE THIS EVENING. MEANWHILE...THE LOW CLOUDS SHOULD CONTINUE EAST OF HIGHWAY 25 THIS AFTERNOON. THE MOISTURE IS TRAPPED BENEATH AN UPPER RIDGE AND SUBSIDENCE BUILDING OVER THE NEBRASKA/KANSAS BORDER. A MID LEVEL TROF AXIS ACROSS THE DAKOTAS WILL TRY TO BRING IN A DRY WESTERLY WIND...BUT THE HEIGHT GRADIENT IS TOO WEAK TO PROMOTE A STRONG DRY SURGE OR GOOD MIXING. EXPECT TEMPERATURES TO BARELY REACH 40 IN THE CLOUDY AREAS...WHILE THE WEST WILL WARM TO THE MID 40S. BURKE. .PREV DISCUSSION... 227 AM MST TUE FEB 1 2005 ...FORECAST PROBLEMS WILL BE CHANCE OF PRECIPITATION TONIGHT/EARLY WEDNESDAY ALONG WITH CLOUDS AND TEMPERATURES THROUGH THURSDAY. SATELLITE CONTINUING TO SHOW AN ACTIVE PATTERN. OVER THE LAST 24 HOURS...THE FLOW HAS BECOME MORE AMPLIFIED...ESPECIALLY FROM THE CENTRAL PACIFIC TO OVER THE WESTERN PORTION OF THE UNITED STATES. NEW CUTOFF LOW HAS DEVELOPED OVER NORTHWEST MEXICO. AREA IS UNDER NORTHERLY FLOW ALOFT WITH A STRONG SHORTWAVE NOW OVER SOUTHWEST CANADA AND THE PACIFIC NORTHWEST. HEIGHT FALLS UP TO 140 METERS HAVE OCCURRED WITH THE APPROACH OF THIS SHORTWAVE. LARGE AREA OF LOW LEVEL MOISTURE AND STRATUS EXTEND FROM EASTERN NEW MEXICO AND WESTERN TEXAS INTO THE NORTH CENTRAL PORTION OF THE COUNTRY. AT JET LEVEL...MODELS WERE SIMILAR. HOWEVER...THE GFS DID A LITTLE BETTER JOB ON THE JET SEGMENT ALONG THE WASHINGTON AND OREGON COASTS. AT MID LEVELS...ON A LARGE SCALE MODELS HAVING THERE PROBLEMS FROM THE NORTH CENTRAL PACIFIC INTO THE PACIFIC NORTHWEST. MODELS APPEAR TO BE UNDERGOING STRENGTH/POSITION OF RIDGE THERE PLUS DO NOT HAVE SYSTEM DEEP ENOUGH OVER THE PACIFIC NORTHWEST. UKMET IS DOING BEST IN THESE AREAS. BASED ON THE UPPER AIR ANALYSIS...GFS/UKMET/ECMWF ARE NOT THAT FAR APART OVER THE COUNTRY. WOULD GIVE A SLIGHT EDGE TO THE UKMET. THROUGH 06Z...THE GFS/UKMET ARE VERY MUCH ALIKE ON POSITION AND STRENGTH OF ALL MAJOR FEATURES WITH THE ECMWF LAGGING BEHIND. DESPITE ITS POOR INITIAL ANALYSIS...THE NAM SUPPORTS AND IS CLOSE TO THE UKMET/GFS. AT LOW LEVELS...NAM/UKMET/RUC WERE DOING WELL WITH SURFACE FEATURES/WINDS...ESPECIALLY TROUGH OVER THE AREA RIGHT NOW. AT 850 MB...MODELS WERE NOT COLD ENOUGH WITH TEMPERATURES ON THE EASTERN AND SOUTHERN SIDES OF LOW LEVEL RIDGE. MODELS WERE NOT FAR ENOUGH WEST AND NORTH WITH THE COLD POCKET FROM SOUTHWEST KANSAS INTO OKLAHOMA AND THE TEXAS PANHANDLE. SNOWPACK IN THIS AREA WILL MAKE IT COLDER THERE FOR A WHILE. OVERALL...UKMET/GFS WERE DOING THE BEST. WILL USE A BLEND OF THE GFS/UKMET WITH A LITTLE MORE WEIGHT TO THE UKMET. TODAY/TONIGHT...ONCE AGAIN TODAY WILL HAVE TO DEAL WITH WHEN THE STRATUS WILL LEAVE OR NOT. YESTERDAY LOCATIONS THAT CLEARED OUT EARLY WARMED UP A LOT. CURRENTLY STRATUS CONTINUES TO MOVE TOWARD THE WEST...AND IS ROUGHLY ALONG AND EAST OF A LINE FROM TRIBUNE TO GOODLAND TO BENKELMAN. MODELS DO NOT APPEAR TO BE SOUTH AND EAST ENOUGH WITH THE WIND...AND CATCHING THIS STRATUS AREA VERY WELL. MSAS/SURFACE ANALYSIS HAS A SURFACE TO THE SOUTH OF US THAT MODELS DO NOT CATCH. GOING BY THE RUC...LOCATIONS IN WESTERN HALF CLEAR OUT BY 18Z WITH CLOUD COVER STILL HANGING ON THE EAST. GRAHAM AND NORTON COUNTY WILL BE THE LAST TO CLEAR OUT. NO FOG BEING REPORTED RIGHT NOW...AND WILL NOT INCLUDE. WILL TIER TEMPERATURES WARMEST TO COOLEST FROM WEST TO EAST. AREA STAYS IN SUBSIDENCE BETWEEN BOTH JET SEGMENTS AND LITTLE TO NO DYNAMICS BETWEEN INCOMING NORTHERN SYSTEM AND EXITING SOUTHERN SYSTEM. COLD POOL AND TROUGH STAY OVER THE AREA. MOISTURE AND INSTABILITY ARE NOT QUITE AS HIGH AS YESTERDAY FOR BOTH TIME PERIODS. INSTABILITY WILL ONLY PRODUCE CLOUD COVER LIKE YESTERDAY. STRONG SYSTEM MOVING IN FROM THE NORTHWEST IS WEAKENED/SHEARED APART BY ALL THE MODELS AS IT APPROACHES/MOVES THROUGH THE AREA. LATEST NAM... GFS...AND HPC PRECIPITATION FORECASTS BARELY BRINGS QPF INTO THE EXTREME WESTERN PORTION OF OUR COLORADO COUNTIES DURING THE NIGHT. BASED ON ABOVE REASONING WILL KEEP TONIGHT DRY. IF SOMETHING DOES HAPPEN...IT WILL BE SPOTTY AND VERY LIGHT. WILL INSTRUCT DAY SHIFT TO TAKE ANOTHER LOOK AT IT. ALSO MODELS BRING UP BOUNDARY LAYER RELATIVE HUMIDITY LATE IN THE NIGHT IN THE EASTERN HALF. WILL INCLUDE PATCHY FOG AT THIS TIME. WILL GO COOLEST IN THE WEST. WEDNESDAY/WEDNESDAY NIGHT...DURING THE DAY...JET SEGMENT AND SHEARED OUT/WEAKENING NORTHERN STREAM SYSTEM MOVES ACROSS THE AREA WITH THE MOST LIFT OVER EASTERN COLORADO. LIGHT PRECIPITATION BRUSHES THE EXTREME WESTERN PORTION OF THE FORECAST AREA EARLY IN THE DAY. BASED ON ABOVE REASONING WILL ALSO KEEP WEDNESDAY DRY AS WELL. AT THE VERY LEAST...THE DYNAMICS WILL SPREAD CLOUD COVER ACROSS THE AREA...AND WILL PROBABLY HOLD BACK HIGH TEMPERATURES. FROM 24 HOURS AGO... NUMERICAL GUIDANCE HAVE BACKED OFF A GREAT DEAL WITH THE WARMUP... ALMOST 10 DEGREES. COOLER AIR FILTERS IN BEHIND EXITING SYSTEM. EVEN WITH A DECENT AMOUNT OF SUN...NORTHERLY FLOW ALOFT SHOULD HELP KEEP TEMPERATURES FROM RISING TOO MUCH. WILL GO NEAR TO BELOW GUIDANCE. CLOUDS DURING THE NIGHT MAY HELP TO KEEP TEMPERATURES UP. THURSDAY/THURSDAY NIGHT...UPPER RIDGE BUILDS IN DURING THIS TIME PERIOD. WEAK SHORTWAVE WITHIN THE RIDGE TRIES TO MOVE THROUGH IT BUT WILL HAVE LITTLE IF ANY AFFECT. INTERESTING UPPER RIDGE ORIENTATION KEEPS AREA IN NORTHEAST FLOW ALOFT. THIS MAY BE THE ONLY THING THAT HOLDS BACK THE WARMUP ADVERTISED BY THE MODELS. WINDS WILL BE LIGHT AND VARIABLE TO LIGHT DOWNSLOPE. WILL TEND TO NEAR TO SLIGHTLY BELOW GUIDANCE. NEW MEX/GFS NOW HAVE BROUGHT MUCH COLDER AIR INTO THE AREA FOR NEXT SUNDAY AND MONDAY. LATEST UKMET/ECMWF ARE SIMILAR TO THE GFS ALTHOUGH DETAILS WILL STILL BE UP IN THE AIR FOR A WHILE. BASED ON THE ABOVE AND COLLABORATION WITH NEIGHBORS...WILL LOWER TEMPERATURES A LITTLE ON SUNDAY AND MORE ON MONDAY. WILL KEEP THIS TIME PERIOD DRY...AND AWAIT FUTURE MODEL RUNS TO SEE IF ADDING IT IS WARRANTED. OTHERWISE...THERE WERE NO OTHER CHANGES PLANNED IN THE 4 TO 7 PERIOD. && .GLD WATCHES/WARNINGS/ADVISORIES... .KS...NONE. .NE...NONE. .CO...NONE. && $$ BULLER ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LOUISVILLE KY 925 AM EST TUE FEB 1 2005 .SHORT RANGE UPDATE (TODAY)... MAIN FORECAST ISSUE TODAY IS LOW CLOUD COVER. CURRENTLY THERE ARE AREAS OF CLEARING NORTH OF LEXINGTON AND LOCATIONS WEST OF I-65, ALONG WITH SOME THINNING CLOUDS NORTH OF KSDF. CONSENSUS OF 12Z NAM/RUC SHOW HIGHEST PROBABILITIES FOR CLOUD COVER CONTINUING OVER SOUTHEASTERN SECTIONS OF LMK FORECAST AREA TODAY, WITH LESSER 850-925MB RH AS ONE HEADS NORTHWESTWARD INTO SOUTHERN INDIANA. OVERALL WILL CONTINUE PARTLY CLOUDY FCST, EXCEPT OVER SOUTHEASTERN CWA WHERE MORE OF A MOSTLY CLOUDY SKY IS EXPECTED. XXV && .LMK WATCHES/WARNINGS/ADVISORIES... IN...NONE. KY...NONE. && $$ ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 1038 PM EST TUE FEB 1 2005 .UPDATE... LATEST FOG CHANNEL IR IMAGERY SHOWS LOW CLOUD COVER STILL REMAINING IN PLACE OVER MOST OF THE CWFA THIS EVENING. THE LATEST IMAGE SHOWS THE CLOUD EDGE ALONG A LINE FROM JUST SOUTH OF KBEH...TO NEAR KBTL...AND THEN JUST NORTH OF KTEW. THE EDGE OF THIS CLOUD BANK WAS INCHING SOUTH EARLIER THIS EVENING...AND IS NOW INCHING BACK NORTH A TAD. THEN OVER LAKE MICHIGAN AND ERN WI...A FEW BREAKS IN THE STRATOCU ARE BEGINNING TO SHOW UP. THE LATEST NAM AND RUC 900 MB RH PROGS SHOW THE EDGE OF THE CLOUD COVER EXPECTED TO INCH NORTH LATER IN THE NIGHT. AREAS WHERE THE LOW CLOUDS ARE NOT IN PLACE...SHOULD SEE FOG DEVELOP ONCE AGAIN THROUGH THE OVERNIGHT HOURS. EVIDENCE OF THIS IS ALREADY SHOWING UP AS LOCATIONS OVER THE EXTREME SE HAVE VISIBILITIES DOWN TO 5SM. WE EXPECT THAT SOME LOCALLY DENSE FOG WILL BE AROUND LATER TONIGHT. HOW MUCH AND THE EXTENT OF IT WILL HAVE TO BE MONITORED FOR A POSSIBLE DENSE FOG ADVISORY LATER. SOME OF THE BREAKS IN THE CLOUDS OVER LAKE MICHIGAN MAY VERY WELL MOVE OVER THE CWFA LATER TONIGHT. THESE BREAKS IN THE CLOUDS COMBINED WITH LOW TEMP/DEW POINT DEPRESSIONS AND LIGHT WINDS MAY ALLOW SOME PATCHY FOG TO DEVELOP ELSEWHERE OVERNIGHT. THE BREAKS ARE EXPECTED TO REMAIN RATHER SMALL AND THEREFORE THE FOG SHOULD BE MORE PATCHY IN NATURE IN COMPARISON TO THE SE SECTION OF THE CWFA WHERE BETTER RADIATIONAL COOLING CONDITIONS WILL BE FOUND WITH THE LACK OF SYNOPTIC MOISTURE. AREAS WITH THE CLOUDS OVERHEAD WILL ONCE AGAIN REMAIN MILD OVERNIGHT WITH TEMPS ONLY FALLING A FEW DEGREES AT MOST. TEMPS AS OF 03Z AT MOST OBS WITH THE LOW CLOUDS OVERHEAD REMAIN IN THE UPPER 20S TO LOWER 30S. TEMPS AT OB SITES WITH CLEAR SKIES HAVE ALREADY FALLEN INTO THE UPPER TEENS TO LOWER 20S. WE HAVE ADJUSTED MIN TEMPS SLIGHTLY TO REFLECT CURRENT TRENDS. && .GRR WATCHES/WARNINGS/ADVISORIES...NONE. && $$ NJJ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 900 PM EST TUE FEB 1 2005 .DISCUSSION... .SHORT TERM... 00Z RAOBS/WV IMAGERY AND RUC ANALYSIS SHOW CONTINUED SPLIT FLOW ACRS NAMERICA...WITH ZONAL NRN BRANCH OVER SRN CAN. FA UNDER INFLUENCE OF SHRTWV RDGING BTWN THIS JET AND SRN BRANCH FLOW ACRS THE SRN CONUS. AT THE SFC...1035MB HI PRES RDG NOTED ACRS SRN LWR MI. FA IN SW FLOW BTWN THIS HI AND LO PRES OVER SCNTRL CAN ASSOCIATED WITH SHRTWV EMBEDDED WITHIN ZONAL NRN BRANCH. LOCAL 00Z RAOBS/TAMDAR SDNGS INDICATE PERSISTENT SUBSIDENCE INVRN H85-9 TRAPPING LLVL MSTR... WITH WDSPRD SC OVC NOTED AGAIN. HOWERVER...A HOLE IN THE OVC OBSVD OVER THE CNRL FA THIS EVNG. THIS HOLE DVLPD LATE IN THE AFTN OVER THE WRN COUNTIES WHERE PREVAILING SW FLOW DOWNSLOPED DURING DIURNAL MIXING AND HAS SPREAD ENE WITH LLVL FLOW. SKIES HAVE BECOME CLDY OVER THE WRN CWA...BUT ARE CLRG TO THE E IN ADVANCE OF THE HOLE. OTRW...SFC TEMPS GENERALLY 28 TO 35... WITH DWPTSIN THE 20S TO NR 30. MAIN FCST CONCERNS TNGT ARE LO CLD TRENDS/IMPACT ON LO TEMPS AND PSBL FOG. LATEST MODEL RUNS SHOW A FAIRLY PERSITENT SW FLOW TNGT...MAINTAINED BY NEARLY STNRY RDG OF HI PRES IN THE LOWER GRT LKS AND LOWER PRES OVER SNCTRL CAN ASSOCIATED WITH SHRTWVS TRACKING THRU ZONAL FLOW THERE. WITH LOSS OF DIURNAL MIXING AND PERSISTENT INVRN...HOLE IN THE WDSPRD SC SHOULD SHRINK WITH TIME. ALTHOUGH SOME FOG MAY DVLP DURING WINDOW OF DIURNAL COOLING UNDER SC HOLE...THINK STEADY SW WIND (AOA 20 KT AT H925) AND EXPECTED LIMITED WINDOW OF CLR-PCLDY SKIES WL PREVENT VSBY FROM NOSEDIVING TO LEVEL TO INCLUDE IN PUBLIC FCST. WL LOWER FCST MIN TEMPS (MADE WITH ASSUMPTION OF OVC ALL NGT) OVER THE CNTRL FA TO ACCOUNT FOR ENHANCED RADIATIONAL HEAT LOSS DURING PD OF CLR-PCLDY SKIES BUT NOT GO OVERBOARD CONSIDERING WIND/WINDOW OF OPPORTUNITY. KC .LONG TERM... LITTLE OVERALL CHANGE IS EXPECTED FOR THE NEXT SEVERAL DAYS. A SERIES OF SHORTWAVES WILL PASS TO THE N OF HERE AND REALLY NOT AFFECT OUT WEATHER. SHORTWAVE CURRENTLY OVER SASKATCHEWAN WILL WEAKEN AND TRACK ACROSS THE UPPER GREAT LAKES/ONTARIO WED AFTN/EVENING WITH BARELY EVEN ANY REFLECTION AT THE SFC. SHORTWAVE MIGHT STIR UP ENOUGH MIXING TO POKE HOLES IN THE LOW CLOUD DECK...BUT AGAIN A PERSISTENCE FCST IS THE WAY TO GO UNTIL CLOUDS SHOW DEFINITE SIGNS OF BREAKING. WITH EXPECTED CLOUD COVER...HIGH (LOW) TEMPS WED (WED NIGHT) SHOULD BE ABOUT THE SAME AS TODAY (TONIGHT). LIKE A BROKEN RECORD...EXPECT MORE OF THE SAME ON THU. NAM IS SUGGESTING LOW-LEVEL MOISTURE WILL BREAK TO ALLOW FOR SOME SUNSHINE ON THU...AND WITH LOW-LEVEL FLOW A LITTLE MORE WRLY...THAT IS A POSSIBILITY. HOWEVER...WILL CONTINUE WITH A PERSISTENCE FCST AND STAY WITH MOSTLY CLOUDY SKY FOR NOW. WILL HOWEVER BUMP TEMPS UP A FEW OF DEGREES FROM WED IN LIGHT OF BETTER POTENTIAL OF CLOUDS TO BREAK. IF CLOUDS DO BREAK...TEMPS SHOULD HAVE NO TROUBLE RISING INTO THE LOW-MID 40S. NEXT SHORTWAVE IN THE NRN STREAM TRACKS ACROSS ONTARIO EARLY FRI. GFS HAS BEEN BACKING AWAY STEADILY FROM THE COLD SHOT IT SHOWED AS THIS WAVE PASSES AND HAS TRENDED STRONGLY TOWARD THE ECMWF WHICH HAS HAD THE BEST HANDLE ON THE PATTERN FOR THIS WEEK. NAM/GFS ARE VERY SIMILAR ON DEGREE OF COOLING WITH 850MB TEMPS DROPPING TO AROUND -4C BY 00Z SAT. THIS IS PROBABLY STILL TOO COLD BASED ON ECMWF/CANADIAN GLOBAL. BEST FORCING WITH SHORTWAVE PASSES BY TO THE N...SO WILL MAINTAIN DRY FCST ON FRI. WITH WEAK FRONT PASSING THRU THE AREA... FRI MIGHT BE THE BEST OPPORTUNITY FOR SUN. DEPENDING ON TIMING OF FRONT (NEW 12Z/01 ECWMF IS SLOWER AND LOOKS LIKE THE FRONT NEVER REALLY DROPS INTO UPPER MI)...FRI COULD BE QUITE WARM (MUCH WARMER THAN THE UPPER 30S THAT WILL BE REFLECTED IN THIS FCST). SAT-TUE...WILL FOLLOW ECMWF SOLUTION CLOSELY TODAY AS IT HAS SHOWN VERY GOOD RUN-TO-RUN CONSISTENCY AND IS SUPPORTED BY CANADIAN/UKMET. GFS RUNS HAVE BEEN STEADILY AND SLOWLY TRENDING TOWARD THE ECMWF SOLUTIONS OF RECENT...INCLUDING THE EVER WEAKER COLD PUSH ON FRI AND TREND TOWARD A WARMER LOOK OVER THE WEEKEND AHEAD OF APPROACHING COLD FRONT. SPLIT FLOW CONTINUES INTO THE WEEKEND WITH SOME AMPLIFICATION OF BOTH STREAMS...RESULTING IN TROF OVER WRN NAMERICA AND BUILDING RIDGE OVER THE E. LOOKS QUITE WARM SAT OVER THE UPPER GREAT LAKES WITH DEEP SWRLY FLOW. ECMWF 850MB TEMPS ARE 4-6C SAT WITH 1000-500MB THICKNESS RUNNING 546DM (EVEN HIGHER PER CANADIAN GLOBAL)...AND NO SURPISE HERE...THE 12Z GFS IS NOW ON TRACK WITH THE ECMWF ON THE DEGREE OF WARMTH. CLOUD COVER WILL CONTINUE TO BE AN ISSUE...AND PERSISTENCE WITH CLOUDS DOMINATING SHOULD BE THE WAY TO GO. SO WILL NOT GO TOO HIGH ON AFTN TEMPS SAT (UPPER 30S). IF IT TURNS OUT SUNNY...TEMPS COULD EASILY SOAR WELL INTO THE 40S. WITH DEEP SW FLOW...MIN TEMPS SUN MORNING MAY STAY ABOVE FREEZING ACROSS ENTIRE FCST AREA (00Z GFS MOS IS RIDICULOUSLY TOO COLD). FRONT EDGES INTO UPPER MI SUN AS NRN STREAM SHORTWAVE HEADS INTO NRN ONTARIO. MEANWHILE...A SRN STREAM SHORTWAVE WILL BE LIFTING NE INTO THE GREAT LAKES. GIVEN THE EXPECTED WARMTH...HAVE A HARD TIME INCLUDING ANYTHING BUT -RA IN THE FCST AHEAD OF FRONT. WILL THEN TRANSITION TO -SN SUN NIGHT AND MON AS COLDER AIR DROPS BACK INTO THE AREA. PER ECMWF...IT MAY NOT BE COLD ENOUGH TO GENERATE ANY LES MON WITH 850MB TEMPS ONLY FALLING TO AROUND -10C. HIGH PRES WILL THEN SETTLE OVER THE MIDWEST/WRN LAKES TUE...AND WILL GO WITH A DRY FCST WITH EXPECTATION OF AIRMASS NOT BEING COLD ENOUGH TO SUPPORT LES. ROLFSON && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAS VEGAS NV 421 PM PST TUE FEB 1 2005 .SYNOPSIS...HIGH PRESSURE OVER NORTHERN NEVADA WILL KEEP DRY CONDITIONS ACROSS THE SOUTHERN GREAT BASIN AND MOJAVE DESERT THROUGH THE WEEK. && .UPDATE...SURPRISE SHORTWAVE HAS SNEAKED IN FROM THE NORTHEAST AND KICKED OFF LOTS OF TOWERING CUMULUS AND VIRGA/MOUNTAIN SHOWERS OVER THE LAS VEGAS VALLEY AND SURROUNDING AREAS. THIS SHORTWAVE WAS COMPLETELY MISSED BY NUMERICAL MODELS THROUGH THE 12Z RUNS. THE 18Z ETA12 AND 21Z RUC SHOW THE WAVE ITSELF...BUT BADLY UNDERFORECAST THE AMOUNT OF MOISTURE ASSOCIATED WITH IT. UPDATED SEVERAL ZONES TO MENTION CLOUDS AND/OR ISOLATED SHOWERS UNTIL MIDNIGHT. .PREV DISCUSSION... 200 PM PST TUE FEB 1 2005 .SHORT TERM...SHORT WAVE CONTINUING TO DROP SOUTH INTO NORTHERN BAJA LEADING TO PROG SOLUTION ON BOTH GFS/NAM THAT LOW TO FORM OVER NORTHERN BAJA BY 00Z THURSDAY. WITH LOW OVER NORTHERN BAJA...FLOW ALOFT TO BECOME MORE NORTHEAST...BUT OVERALL DRY. SOME MID LEVEL MOISTURE MAY OCCASIONALLY DRIFT THROUGH THE FLOW...HOWEVER MOSTLY CLEAR SHOULD COVER THE SKY COVER THROUGH THE SHORT TERM. NORTH/SOUTH SURFACE GRADIENTS TO CONTINUE INTO WEDNESDAY BEFORE RELAXING SOMEWHAT INTO THURSDAY...THUS KEEPING LOCALLY BREEZY CONDITIONS INTO AT LEAST WEDNESDAY. NAM MOS A LITTLE COOLER THAN GFS WITH COMPROMISE SEEMINGLY THE BEST WAY TO GO AND WILL CONTINUE THIS TREND...THUS TEMPS TO WARM TO NEAR OR SLIGHTLY ABOVE NORMAL BY THURSDAY. .LONG TERM...MEDIUM RANGE MODELS NOW IN BETTER AGREEMENT WITH THE RECENT ARRIVAL OF THE 18Z DGEX AND THE 12Z EURO. LOW OVER BAJA ON FRIDAY EXPECTED TO OPEN UP AND EJECT EAST EARLY SATURDAY WHILE A WEAK SYSTEM MOVES THROUGH THE PACNW AND WEAKENS THE RIDGE NUDGING IN OVER NORTHERN CA/NV. RIDGE SHOULD THEN REBUILD BRIEFLY ON SATURDAY BEFORE INSIDE SLIDER TROUGH MOVES INTO UTAH MOST LIKELY ON SUNDAY. THERE ARE STILL SOME TIMING DIFFERENCES WITH THIS...BUT MAJOR MODEL CHANGE IS THAT THE EURO IS NOW ALSO SHOWING THIS SOLUTION INSTEAD OF BRINGING A CLOSED LOW DOWN THROUGH CALIFORNIA. THIS SHOULD HELP KICK UP SOME BREEZES SUNDAY AND MONDAY...ESP OVER THE EASTERN CWA AND THE COLORADO RIVER. NO MAJOR CHANGES MADE TO GRIDDED DATABASE SUNDAY THROUGH TUESDAY AND NEXT SHIFT MAY NEED TO BUMP UP WINDS A LITTLE INTO THE EXTENDED. .AVIATION...TAF ADEQUATELY COVERS ALL SIGNIFICANT WEATHER EXPECTED AT KLAS. .VEF WATCHES/WARNINGS/ADVISORIES... .NV...NONE. .AZ...NONE. .CA...NONE. && $$ JENSEN/DAVIS/MORGAN nv AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE RALEIGH NC 940 AM EST TUE FEB 1 2005 .SHORT TERM (REST OF TODAY THROUGH TONIGHT)... MODELS OTHER THAN THE RUC SEEM TO HAVE DIFFICULTY WITH STRATUS AND TRAJECTORIES AT THE 850MB LEVEL. STRATUS MOVED INTO GREENSBORO NEAR 11Z AND CHARLOTTE NEAR 12Z AND LOOKS TO MOVE INTO RALEIGH. RUC TRAJECTORIES SUGGEST A SLIGHTLY DIFFERENT SOURCE REGION FOR AIR MASS IN THE FAR EAST WITH SPEEDS SLIGHTLY HIGHER. THUS EXPECT STRATUS TO COVER THE WESTERN TWO THIRDS OF AREA INTO EARLY TONIGHT WHEN TRAJECTORIES SHIFT TO MORE NORTHEAST AND STRATUS SHOULD CLEAR OR BE PUSHED WEST. WILL DROP TEMPERATURES UNDER STRATUS FOR TODAY. WITH EXPECTED CLEARING BEFORE MIDNIGHT...WILL LEAVE MINIMUMS LITTLE CHANGED. MUCH DRIER IN THE MID LEVELS BY WEDNESDAY SUNRISE THAN THIS MORNING...BUT WITH NEAR SATURATION IN A SHALLOW LAYER AT THE SURFACE AND SOME CIRRUS MOISTURE PUSHING OVER THE RIDGE ALOFT. EXPECT SOME FOG TONIGHT BUT VISIBILITIES WELL ABOVE ONE MILE. && .RAH WATCHES/WARNINGS/ADVISORIES... NC...NONE. && $$ SHORT TERM...RLH nc AREA FORECAST DISCUSSION...CORRECTED ISSUANCE TIME NATIONAL WEATHER SERVICE CLEVELAND OHIO 945 PM EST TUE FEB 1 2005 .SHORT TERM UPDATED (TONIGHT)... WL MAKE A FEW MINOR CHANGES TO FORECAST TEXT. WL REMOVE THE AFTER MIDNIGHT WORDING AS SOME DENSE FOG NOW BEGINNING TO FORM. RUC AND OTHER MODELS INDICATE THE BOUNDARY FLOW TO COME AROUND MORE FROM THE EAST OVERNIGHT AND THE DOWNSLOPE DRIER AIR MAY HELP KEEP DENSE FOG FROM BECOMING AS WIDESPREAD ALTHOUGH MOST AREAS WILL SEE AT LEAST MVFR TYPE FOG. SPREADING STRATUS WILL ALSO HELP SLOW THE RADIATING PROCESS SO WILL CONTINUE WITH A STATEMENT ABOUT AREAS OF DENSE FOG BUT WILL NOT ISSUE AN ADVISORY. WL LOWER MIN TEMPERATURES A BIT OR AT LEAST OPEN UP A RANGE AS JUST AS IN RECENT NIGHTS SOME AREAS WILL RADIATE MUCH BETTER THAN OTHERS AND WITH SNOW COVER SOME LOCATIONS WILL GET QUITE COLD AGAIN ALTHOUGH MOST LOWS SHOULD BE IN THE TEENS TO AROUND 20. UPDATE AT 945 PM && .PREVIOUS DISCUSSION FROM 311 PM... SHORT TERM (TONIGHT THRU THURS)... FOG WILL ONCE AGAIN BE A PROBLEM ACROSS THE AREA TONIGHT AS HIGH PRESSURE CENTERS OVER THE REGION. CURRENT STRATUS AND FOG QUICKLY DISSIPATING THIS AFTERNOON AND THIS WILL ALLOW SKIES TO CLEAR THROUGH THE EARLY EVENING. HOWEVER...INVERSION WILL SETTLE BACK DOWN THIS EVENING TRAPPING LOW LEVEL MOISTURE NEAR THE SURFACE FROM LAKE ERIE IN LIGHT EAST TO NORTHEAST FLOW. NGM MODEL SUGGESTS LOW LEVEL FLOW WILL BECOME SOUTHEAST OVERNIGHT AND IF THIS SCENARIO SETS UP THEN SUBSIDENCE MAY HELP KEEP DENSE FOG FROM FORMING NEAR THE LAKE SHORE FROM LAKE COUNTY TO ERIE COUNTY PA. THE REST OF THE MODELS INDICATE WINDS WILL BECOME LIGHT AND VARIABLE. I AM EXPECTING SOME AREAS OF DENSE FOG TO DEVELOP AGAIN TONIGHT...ESPECIALLY AWAY FROM THE LAKE AND OVER THE TOLEDO TO FINDLAY AREA. TEMPERATURES WILL DROP INTO THE 20S AND TEENS AGAIN TONIGHT...I WOULD EXPECT FREEZING FOG TO GLAZE EXPOSED UNTREATED SURFACES AND CAUSE PROBLEMS OVERNIGHT INTO WEDNESDAY MORNING. USERS WITH PUBLIC ACCESS...WILL YOU PLEASE HIGHLIGHT THIS PROBLEM SINCE TRAVEL MAY BECOME DIFFICULT OVERNIGHT AGAIN. I WILL ISSUE A SPECIAL WEATHER STATEMENT MENTIONING THE FREEZING FOG AS WELL. FOG AND STRATUS WILL EVENTUALLY BURN OFF DURING THE MORNING HOURS WEDNESDAY AS THE HIGH PRESSURE SYSTEM SHIFTS SLOWLY EAST OF THE AREA AND WEAK UPPER LEVEL RIDGE DOMINATES THE AREA THROUGH THE DAY. DEPENDING ON WHERE OUR RODENT PROGNOSTICATORS WILL BE TOMORROW ACROSS THE FORECAST AREA...THERE IS THE POSSIBILITY THAT SOME MAY PREDICT AN EARLY END TO WINTER IF THEY ARE UNDER THE STRATUS DECK AND OTHERS SAY SPRING WILL LAST SIX MORE WEEKS IF THEY SEE THE SUN. AN UPPER LEVEL LOW PRESSURE SYSTEM AND ITS ASSOCIATED VORT MAX WILL MOVE EAST ACROSS KENTUCKY AND WEST VIRGINIA THURSDAY. SURFACE LOW IS PROGGED TO STAY WELL SOUTH OF THE AREA KEEPING THE FORECAST AREA DRY. TEMPERATURE GUIDANCE HAS BEEN RUNNING A BIT WARM IN LAST FEW RUNS DUE TO EXPECTANT SUNSHINE BUT WITH STRATUS AND FOG LINGERING INTO THE EARLY AFTERNOON...TEMPERATURES ARE BEING HELD AT BAY. WILL LOWER MAXIMUM TEMPERATURES FOR TOMORROW A TAD TO AROUND 30 IN THE WEST AND LOWER 30S ELSEWHERE. && .LONG TERM (FRI THRU TUES)... MASSIVE UPPER LEVEL RIDGE AND SURFACE HIGH PRESSURE SYSTEM WILL BUILD ACROSS THE FORECAST AREA FRIDAY THROUGH SUNDAY. WARMING TEMPERATURES CAN BE EXPECTED SUNDAY INTO SUNDAY NIGHT AHEAD OF A STORM SYSTEM PROGGED TO MOVE NORTHEAST UP THE MISSISSIPPI VALLEY REGION. COLD FRONT WILL MOVE INTO THE AREA MONDAY EVENING USHERING IN COLDER TEMPERATURES AND A RETURN BACK TO SNOW BY TUESDAY. PROBLEMS TO LOOK OUT FOR DURING THE EXTENDED PERIODS IS THE POTENTIAL FOR A RETURN TO FLOODING SITUATIONS. WET BULB ZERO TEMPERATURES ARE EXPECTED TO RISE WELL ABOVE ZERO SUNDAY NIGHT INTO MONDAY MORNING. WARM SOUTH TO SOUTHWEST FLOW AT 10 TO 20 KNOTS WILL HELP MELT SNOW PACK IN PLACE. SOIL TEMPERATURES LIKELY TO BE FROZEN WITHIN FIRST INCH OR SO SINCE SNOW HAS INSULATED THE SOIL FROM FRIGID COLD TEMPERATURES OVER THE LAST COUPLE WEEKS. RAINFALL EXPECTED WITH THE COLD FRONT WILL BE IN ADDITION TO APPROXIMATELY ONE INCH OF LIQUID LOCKED UP IN THE SNOW PACK AT THIS TIME. COMBINATION OF SNOW AND RAIN WILL RESATURATE THE SOILS CAUSING RUNOFF TO OCCUR. DEPENDING ON HOW WARM WE GET AND HOW MUCH RAIN FALLS WITH THE WARM FRONT AND COLD FRONT...IT STILL REMAINS A QUESTION ON HOW THIS WILL AFFECT ICE THAT HAS DEVELOPED ON THE RIVERS. WE WILL CONTINUE TO MONITOR THIS SITUATION CLOSELY THROUGH THE WEEK INTO THE WEEKEND AS IT DEVELOPS. OTHERWISE...AS MENTIONED TEMPERATURES EXPECTED TO WARM UP THROUGH THE WEEKEND BUT WARM UP SHOULD BE SHORT LIVED AND PLUNGE TEMPERATURES BACK TO BELOW FREEZING TUESDAY SHUTTING DOWN RUNOFF. && .AVIATION (18Z-18Z)... IFR CIGS AND VSBYS IN STRATUS AND FOG CONT TO SLOWLY DSIPT AND SHOULD BE GONE ALL AREAS BY MID AFTN THOUGH HZ MAY LNGR W AND LKSHORE AREAS. SYNOPTIC PATTERN CHNGG LTL DURING THE NEXT 24HR AND EXPECT IFR CIGS AND VSBY TO DVPL AGAIN TNGT LNGRNG UNTIL LATE IN TAF PD AGAIN WED MUCH LIKE TDA CONDS. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE && UPDATED SHORT TERM...KOSARIK SHORT TERM...LOMBARDY LONG TERM...LOMBARDY AVIATION...WCR $$ oh AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE STATE COLLEGE PA 956 PM EST TUE FEB 1 2005 .SHORT TERM (REST OF TONIGHT)... NO UPDATE PLANNED AS CLEAR SKIES AND LIGHT WINDS ARE RIGHT ON SCHEDULE. NO SIGN OF SIG WX ANY TIME SOON EITHER...VERY UNUSUAL FOR THE DEAD OF WINTER. LA CORTE && .PREVIOUS DISCUSSION... THE FOLLOWING WAS ORIGINALLY ISSUED AT 157 PM EST TUE FEB 1 2005 SYNOPSIS... THE NEXT 7 DAYS WILL FEATURE A MEAN...SFC/UPR RIDGE ACROSS THE EASTERN US WITH MAINLY DRY WEATHER AND MAX/MIN TEMPS SEVERAL DEGREES ABOVE NORMAL. A SOUTHERN STREAM CLOSED...MID/UPPER LOW (CURRENTLY OVER THE SOUTHERN ROCKIES) WILL MOVE EAST AND CROSS THE CENTRAL/SOUTHERN APPALACHIANS LATE THUR AND FRIDAY...BRINGING A GLANCING BLOW OF CLOUDS (AND POSSIBLY A BIT OF LIGHT SNOW) TO MAINLY OUR SOUTHERN AND EASTERN ZONES. AVIATION... HIGH PRESSURE DOMINATES REGION WITH ALL LOCATIONS REPORTING CLEAR SKIES. MORNING INVERSION DID ALLOW THE FORMATION OF SOME FOG IN IPT AND MDT. MDT CONTINUES TO HANG TOUGH WITH MVFR CONDITIONS AND A 5 MILE VISIBILITY. THINK THERE WILL BE ENOUGH MIXING TO BRING THEM TO VFR CONDITIONS LATE TODAY AND FOR A WHILE TONIGHT...BUT SIMILAR SETUP OVERNIGHT WILL AGAIN LEAD TO SOME FOG. INCLUDED FOG IN TAFS FOR BFD, IPT AND MDT. OTHERWISE...ANOTHER DAY OF NO CEILINGS EXPECTED THROUGH THE TAF PERIOD...18Z ON THE 2ND. SHORT TERM (TONIGHT THROUGH FRIDAY)... CLEAR SKIES COVERED ALL BUT THE EXTREME NW CORNER OF PENN THIS AFTERNOON THANKS TO A 1033 MB HIGH CENTERED ACROSS WESTERN NEW YORK. 18Z TEMPS WERE SURPRISINGLY UNIFORM ACROSS THE COMMONWEALTH...MAINLY IN THE LOWER TO MID 30S WITH ONLY A RANGE OF 3-4 DEG F. ANOTHER CLEAR NIGHT ON TAP WITH TEMPS DROPPING QUICKLY EARLY THIS EVENING UNDER IDEAL RADIATIONAL COOLING CONDITIONS. ONCE AGAIN...THE RUC IS FAVORED FOR LOWS...ESPECIALLY ACROSS THE NORTHERN MOUNTAINS WHERE THE GREATEST DISCREPANCY FROM MAV/MET MOS OCCURS. OVER THE REGION NORTH OF I-80...WE SHOULD SEE TEMPS FALL INTO THE SINGLE DIGITS IN MANY AREAS...WITH THE TYPICALLY COLD VALLEYS SEEING A DAYBREAK READING AROUND ZERO. THIS IS NOT DRASTICALLY DIFFERENT FROM WHAT WE HAD IN OUR PREVIOUS HOURLY TEMP GRIDS...BUT DOES REQUIRE A DOWNWARD ADJUSTMENT OF SEVERAL DEG. THE SHALLOW SFC BASED INVERSION BREAKS QUICKLY DURING THE MID MORNING HOURS WEDNESDAY...LEADING TO ANOTHER SUNNY MILD DAY WITH HIGH TEMPS IN THE UPPER 30S...TO LOWER 40S SE. A LIGHT EAST TO NORTHEAST LLVL FLOW DEVELOPS WED NIGHT AND THURSDAY AS THE CENTER OF THE SFC HIGH SHIFTS FURTHER NORTH AND EAST. THIS WILL BE FOLLOWED BY AN INCREASE IN HIGH CLOUDS EAST...AND MID LEVEL CLOUDS ACROSS THE SOUTHERN AND WRN ZONES DURING THE DAY THURSDAY AS THE AFOREMENTIONED CLOSED LOW DRIFTS FROM THE MID MISS VALLEY TO THE MTNS OF NORTH CAROLINA BY LATE THURSDAY NIGHT. STRONG UVVEL AND LOCALLY HEAVY SNOW EXISTS BENEATH THE COUPLED JET REGION OVER W TEXAS AT PRESENT. THIS AREA OF DEEP LIFT IN THE ATMOSPHERE WILL SHIFT NE ACROSS THE MID MISS VALLEY DURING THE DAY WED...BEFORE TURNING EAST ACROSS ACROSS THE LOWER OHIO VALLEY AND VIRGINIAS ON THURSDAY. THE NORTHERN EDGE OF THE UVVEL AND COUPLED JET STRUCTURE WILL DIMINISH QUICKLY DURING THIS SAME PERIOD AS THE NORTHERN SEGMENT (AND RIGHT ENTRANCE REGION) OF THE SUBTROPICAL JET LIFTS NE...BECOMES STRONGLY ANTICYCLONIC...AND WEAKENS QUICKLY AS IT MOVES OVER THE LOWER GREAT LAKES. WHAT THIS MEANS FOR OUR LOCAL WEATHER IS "PROBABLY" NOT TOO MUCH IN THE WAY OF CLOUDS OR MEASURABLE PRECIP LATE THURSDAY THROUGH FRIDAY. STILL...THE HIGH SIDE OF THE ENSEMBLE MOS POPS FOR THIS PERIOD IS IN THE LIKELY...60-70% POP RANGE (THANKS TO AN EVEN INCREASING NUMBER OF 12Z MEMBERS DISPLAYING 0.10" AMOUNTS) AS COMPARED TO ABOUT 30-40% OF THE 00Z RUN MEMBERS. VERY STRONG UPPER LEVEL DIVERGENCE (-2 TO -3 STANDARD DEVIATIONS TO THE 250 MB U COMPONENT OF THE WIND) DEVELOPS ALONG THE MID ATLANTIC COAST THUR NIGHT WITH INCREASING LLVL CONVERGENCE AT THE NOSE OF 3 TO 4 STANDARD DEVIATION 850 MB EASTERLY JET. THEREFORE...I DON'T FEEL COMPLETELY CONFIDENT AT THIS POINT THAT SOME LIGHT SNOW (OR A MIX EXTREME SE) COULD DEVELOP THURSDAY NIGHT THROUGH FRIDAY. IT'S INTERESTING TO NOTE THOUGH THAT BOTH THE OPERATIONAL NAM AND GFS ARE DRY OVER ALL OF OUR FORECAST AREA DURING THIS PERIOD OF INTEREST. LONG TERM (FRIDAY NIGHT THROUGH TUESDAY)... THE EXITING CLOSED LOW OFF THE SE US COAST WILL BE REPLACED BY A NORTHERLY FLOW AT THE SFC AND ALOFT SATURDAY. SAT/SAT NIGHT WILL TURN OUT TO BE THE COOLEST OF THE MEDIUM RANGE PERIOD...WITH THE MEAN LOW/MID LEVEL FLOW VEERING TO THE S/SW BY THE CLOSED OF THE WEEKEND. A BROAD SW FLOW ALOFT WILL BRING INCREASING CLOUDS AND THE CHC FOR PRECIP DURING THE EARLY TO MIDDLE PART OF NEXT WEEK. THE DEGREE OF UPPER CONFLUENCE/STRENGTH OF THE SFC HIGH PRESSURE OVER SE CANADA IS STILL IN QUESTION DURING THIS PERIOD SO FOR NOW WE'LL GO WITH CHANCE OF MIXED PRECIP FOR MOST PLACES BEGINNING ON MONDAY (ACROSS THE WEST) AND ALL AREAS MON NIGHT AND TUESDAY. && .CTP WATCHES/WARNINGS/ADVISORIES... PA...NONE. && $$ SHORT TERM (UPDATE)...LACORTE pa AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 157 PM EST TUE FEB 1 2005 .SYNOPSIS... THE NEXT 7 DAYS WILL FEATURE A MEAN...SFC/UPR RIDGE ACROSS THE EASTERN US WITH MAINLY DRY WEATHER AND MAX/MIN TEMPS SEVERAL DEGREES ABOVE NORMAL. A SOUTHERN STREAM CLOSED...MID/UPPER LOW (CURRENTLY OVER THE SOUTHERN ROCKIES) WILL MOVE EAST AND CROSS THE CENTRAL/SOUTHERN APPALACHIANS LATE THUR AND FRIDAY...BRINGING A GLANCING BLOW OF CLOUDS (AND POSSIBLY A BIT OF LIGHT SNOW) TO MAINLY OUR SOUTHERN AND EASTERN ZONES. && .AVIATION... HIGH PRESSURE DOMINATES REGION WITH ALL LOCATIONS REPORTING CLEAR SKIES. MORNING INVERSION DID ALLOW THE FORMATION OF SOME FOG IN IPT AND MDT. MDT CONTINUES TO HANG TOUGH WITH MVFR CONDITIONS AND A 5 MILE VISIBILITY. THINK THERE WILL BE ENOUGH MIXING TO BRING THEM TO VFR CONDITIONS LATE TODAY AND FOR A WHILE TONIGHT...BUT SIMILAR SETUP OVERNIGHT WILL AGAIN LEAD TO SOME FOG. INCLUDED FOG IN TAFS FOR BFD, IPT AND MDT. OTHERWISE...ANOTHER DAY OF NO CEILINGS EXPECTED THROUGH THE TAF PERIOD...18Z ON THE 2ND. && .SHORT TERM (TONIGHT THROUGH FRIDAY)... CLEAR SKIES COVERED ALL BUT THE EXTREME NW CORNER OF PENN THIS AFTERNOON THANKS TO A 1033 MB HIGH CENTERED ACROSS WESTERN NEW YORK. 18Z TEMPS WERE SURPRISINGLY UNIFORM ACROSS THE COMMONWEALTH...MAINLY IN THE LOWER TO MID 30S WITH ONLY A RANGE OF 3-4 DEG F. ANOTHER CLEAR NIGHT ON TAP WITH TEMPS DROPPING QUICKLY EARLY THIS EVENING UNDER IDEAL RADIATIONAL COOLING CONDITIONS. ONCE AGAIN...THE RUC IS FAVORED FOR LOWS...ESPECIALLY ACROSS THE NORTHERN MOUNTAINS WHERE THE GREATEST DISCREPANCY FROM MAV/MET MOS OCCURS. OVER THE REGION NORTH OF I-80...WE SHOULD SEE TEMPS FALL INTO THE SINGLE DIGITS IN MANY AREAS...WITH THE TYPICALLY COLD VALLEYS SEEING A DAYBREAK READING AROUND ZERO. THIS IS NOT DRASTICALLY DIFFERENT FROM WHAT WE HAD IN OUR PREVIOUS HOURLY TEMP GRIDS...BUT DOES REQUIRE A DOWNWARD ADJUSTMENT OF SEVERAL DEG. THE SHALLOW SFC BASED INVERSION BREAKS QUICKLY DURING THE MID MORNING HOURS WEDNESDAY...LEADING TO ANOTHER SUNNY MILD DAY WITH HIGH TEMPS IN THE UPPER 30S...TO LOWER 40S SE. A LIGHT EAST TO NORTHEAST LLVL FLOW DEVELOPS WED NIGHT AND THURSDAY AS THE CENTER OF THE SFC HIGH SHIFTS FURTHER NORTH AND EAST. THIS WILL BE FOLLOWED BY AN INCREASE IN HIGH CLOUDS EAST...AND MID LEVEL CLOUDS ACROSS THE SOUTHERN AND WRN ZONES DURING THE DAY THURSDAY AS THE AFOREMENTIONED CLOSED LOW DRIFTS FROM THE MID MISS VALLEY TO THE MTNS OF NORTH CAROLINA BY LATE THURSDAY NIGHT. STRONG UVVEL AND LOCALLY HEAVY SNOW EXISTS BENEATH THE COUPLED JET REGION OVER W TEXAS AT PRESENT. THIS AREA OF DEEP LIFT IN THE ATMOSPHERE WILL SHIFT NE ACROSS THE MID MISS VALLEY DURING THE DAY WED...BEFORE TURNING EAST ACROSS ACROSS THE LOWER OHIO VALLEY AND VIRGINIAS ON THURSDAY. THE NORTHERN EDGE OF THE UVVEL AND COUPLED JET STRUCTURE WILL DIMINISH QUICKLY DURING THIS SAME PERIOD AS THE NORTHERN SEGMENT (AND RIGHT ENTRANCE REGION) OF THE SUBTROPICAL JET LIFTS NE...BECOMES STRONGLY ANTICYCLONIC...AND WEAKENS QUICKLY AS IT MOVES OVER THE LOWER GREAT LAKES. WHAT THIS MEANS FOR OUR LOCAL WEATHER IS "PROBABLY" NOT TOO MUCH IN THE WAY OF CLOUDS OR MEASURABLE PRECIP LATE THURSDAY THROUGH FRIDAY. STILL...THE HIGH SIDE OF THE ENSEMBLE MOS POPS FOR THIS PERIOD IS IN THE LIKELY...60-70% POP RANGE (THANKS TO AN EVEN INCREASING NUMBER OF 12Z MEMBERS DISPLAYING 0.10" AMOUNTS) AS COMPARED TO ABOUT 30-40% OF THE 00Z RUN MEMBERS. VERY STRONG UPPER LEVEL DIVERGENCE (-2 TO -3 STANDARD DEVIATIONS TO THE 250 MB U COMPONENT OF THE WIND) DEVELOPS ALONG THE MID ATLANTIC COAST THUR NIGHT WITH INCREASING LLVL CONVERGENCE AT THE NOSE OF 3 TO 4 STANDARD DEVIATION 850 MB EASTERLY JET. THEREFORE...I DON'T FEEL COMPLETELY CONFIDENT AT THIS POINT THAT SOME LIGHT SNOW (OR A MIX EXTREME SE) COULD DEVELOP THURSDAY NIGHT THROUGH FRIDAY. IT'S INTERESTING TO NOTE THOUGH THAT BOTH THE OPERATIONAL NAM AND GFS ARE DRY OVER ALL OF OUR FORECAST AREA DURING THIS PERIOD OF INTEREST. && .LONG TERM (FRIDAY NIGHT THROUGH TUESDAY)... THE EXITING CLOSED LOW OFF THE SE US COAST WILL BE REPLACED BY A NORTHERLY FLOW AT THE SFC AND ALOFT SATURDAY. SAT/SAT NIGHT WILL TURN OUT TO BE THE COOLEST OF THE MEDIUM RANGE PERIOD...WITH THE MEAN LOW/MID LEVEL FLOW VEERING TO THE S/SW BY THE CLOSED OF THE WEEKEND. A BROAD SW FLOW ALOFT WILL BRING INCREASING CLOUDS AND THE CHC FOR PRECIP DURING THE EARLY TO MIDDLE PART OF NEXT WEEK. THE DEGREE OF UPPER CONFLUENCE/STRENGTH OF THE SFC HIGH PRESSURE OVER SE CANADA IS STILL IN QUESTION DURING THIS PERIOD SO FOR NOW WE'LL GO WITH CHANCE OF MIXED PRECIP FOR MOST PLACES BEGINNING ON MONDAY (ACROSS THE WEST) AND ALL AREAS MON NIGHT AND TUESDAY. && .CTP WATCHES/WARNINGS/ADVISORIES... PA...NONE. && $$ SYNOPSIS... AVIATION...JUNG SHORT TERM/LONG TERM...LAMBERT pa AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 754 PM EST TUE FEB 1 2005 .SHORT TERM (REST OF TONIGHT)... UPPER LEVEL RIDGE TO AMPLIFY OVER S APPALACHIANS OVERNIGHT. SURFACE RIDGE REMAINS OVER GREAT LAKES AND NEW ENGLAND...EXTENDING S TO FL. SURFACE WAVE DEVLOPING IN NW GULF...AND SHOULD SEE WARM FRONT MOVING N TOWARD COAST. UPPER LEVEL MOISTURE ACROSS SW PORTION OF AREA WILL BE SLOW TO SPREAD NE AS IT SPILLS OVER RIDGE. MODIFIED CLOUD COVE EARLY TO CAPTURE WIDE RANGE IN CLOUD COER FROM SW TO NE. SOME WEAK ECHOES NOTED UPPER SAVANNAH RIVER VALLEY. REDUCED POPS SLIGHTLY TO MIMIC CLOUD COVER I-26 CORRIDOR. WITH SLIGHT CHANCE POPS...NO MENTION WILL MAKE IT TO ZONES. TEMPERATURES RUNNING A BIT ABOVE EXPECTAIONS ADN 18Z MAV GUIDANCE IN S AND W...WHERE SMALL ADJUSTMENTS WERE MADE. DEW POINTS RUNNING A BIT HIGH AS WELL...AND UPDATED FROM 18Z GFS.RUC WINDS A BIT ABOVE OBSERVATIONS...SO ADJUSTED SPEEDS DOWN A COUPLE OF MPH. MADE SOME CHANGES TO WEATHER GRIDS FROM WED THROUGH THU NIGHT. PREVIOUS FORECAST HAD FREEZING RAIN IN SOME AREAS WHERE TEMPERATURES WERE ABOVE FREEZING. THIS WAS REMOVED. CONSIDERED CHANGING TO LIQUID RAIN IN THOSE AREAS IF NONE WAS PREVIOUSLY FORECAST...BUT BASED ON LATEST MODEL SOUNDINGS...THOSE AREAS WILL MOST LIKELY RECEIVE PRECIPITATION IN THE FORM OF SLEET AND SNOW. ADDDED SOME SLEET AND SNOW ACCUMULATION TO THU AS WELL...ESPECIALLY NW. && .PREVIOUS DISCUSSION... THE FOLLOWING WAS ORIGINALLY ISSUED AT 315 PM EST TUE FEB 1 2005 SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)... S/WV RIDGE AXIS BUILDS OVER THE CWFA TONIGHT...WHICH LOOKS EVEN SHARPER ON THE 12Z SHORT RANGE MODEL RUNS. CONSEQUENTLY...DEEPER RH AND THE LEADING EDGE OF THE BETTER WAA FLOW DELAYED FURTHER... WITH EVEN THE 18Z NAM KEEPING THE TREND OF NO MEASURABLE PCPN IN MY SW CWFA UNTIL WELL AFTER DAYBREAK. MADE JUST TWEAKS TO THE GOING DRY AND COOL TONIGHT FCST UNDER CONSIDERABLE CLOUDINESS. ON WEDNESDAY...POSITIVE TILT UPPER LOW TREKS EASTWARD ACRS THE CENTRAL/SOUTHERN PLAINS WHILE SFC LOW RIPPLES EASTWARD ALONG THE GULF COAST. NOT SURPRISINGLY...THE NAM TREND OF STRONGER SFC PRES NOSING SWD THROUGH THE DAY...REALLY DELAYS THE LOWER LVL MOISTENING...ALONG WITH A WEAKER UPSLOPE COMPONENT AS WELL. DID KEEP A SLIVER OF LIKELY AFTERNOON CVRG ACRS THE FAR SW...WITH A QUICKER TREND DOWN TO SLT CHC EAST OF I-77. FCST SNDS WOULD SUPPORT LIQUID SHOWERS WITH PERHAPS SOME SLEET MIX. DEEPER RH AND BETTER LARGE SCALE FORCING DOES WORK IN FROM THE SOUTHWEST WEDNESDAY NIGHT AS UPPER LOW KEEPS ITS POSITIVE TILT ACRS THE OHIO VALLEY AND UPGLIDE/UPSLOPE FLOW INCREASES WELL NE IN ADVANCE OF SFC FLOW NEAR THE NE GULF. HAVE INCREASED POPS INTO CATEGORICAL RANGE ACRS THE SW 1/2 OF THE CWFA. ETA WET BULB ZEROS DO PLUNGE FURTHER SW THIS RUN BY 12Z THU...BUT ALSO SLASHED IT/S QPF IN HALF FROM THE 00Z RUN...SO EVEN FURTHER NORTH...ACRS NC...IT STILL REMAINS QUESTIONABLE WITHIN MORE CRITICAL MID-LVL THICKNESS VALUES. AT THIS POINT BEST TO STICK CLOSER TO HPC TREND OF AN ADVISORY ICE THREAT. PLAN TO UPDATE SPS TO ADDRESS THREAT. 12 NAM PROGS A QUICKLY RETREATING SFC WET BLUB ZERO LINE INTO NW NC ON THURSDAY... ALSO THE NAM...WHICH DID BETTER ON THE HANDLING THE WARM NOSE ON SATURDAY...DEVELOPS IT NWWD INTO THE I-40 CORRIDOR... WHICH COULD KEEP ANY POTENTIAL SNOW ACCUMS BELOW WARNING AS WELL. LONG TERM (FRIDAY THROUGH TUESDAY)... EARLY PART OF MEDIUM RANGE COULD BE IMPACTED SIGNIFICANTLY BY EVENTS THURSDAY NIGHT...BUT FOR NOW IT WILL BE LEFT DRY. THE HIGH TEMP FORECAST FRIDAY REMAINS PROBLEMATIC...AND FOR NOW...WILL TREND WARMER TOWARD NEW HPC/MEX GUIDANCE. UPPER RIDGING WILL MOVE ACROSS THE FORECAST AREA SATURDAY...WHICH SUPPORTS DRY HIGH PRESSURE THROUGH SUNDAY. MOISTURE SHOULD BEGIN TO RETURN SUNDAY NIGHT AS UPPER TROF DIGS OVER PLAINS. NO REAL SUBSTANTIAL CHANGES WILL BE MADE FOR THIS SYSTEM IN SPITE OF LOW HPC POP...OTHER THAN TO BROADEN THE TIMING OF PRECIP...WHICH SHOULD BE ALL LIQUID. DAY 7 APPEARS TO BE MAINLY DRY. AVIATION... LARGE AREA OF STRATOCU TRAPPED UNDER INVERSION ACROSS FOOTHILLS AND PIEDMONT WILL GRADUALLY MIX AWAY AROUND THE EDGES AND FROM THE TOP DOWN DURING THE AFTERNOON. THIS WILL PUT KCLT/KGMU/KGSP IN AND OUT OF A BROKEN LOW VFR CEILING INTO THE MIDDLE PART OF THE AFTERNOON. KHKY MIGHT HOLD ON TO LATE AFTERNOON. MEANWHILE...MVFR CEILING AT KAVL WILL BE SLOW TO MIX OUT...BUT SHOULD RISE ABOVE 3000 FEET IN THE MIDDLE PART OF THE AFTERNOON. MID LEVEL MOISTURE WILL STREAM PAST JUST TO THE SOUTH OF THE FORECAST AREA INTO THE EARLY EVENING AND MAY AFFECT KAND WITH A MID LEVEL CEILING FROM TIME TO TIME. ALL SITES SHOULD GO VFR THIS EVENING. AT THIS TIME...IT APPEARS THAT THICKENING CLOUDS FROM THE NEXT SYSTEM WILL NOT ARRIVE AT ANY TAF SITES UNTIL AFTER THE END OF THE TAF PERIOD. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SHORT TERM (UPDATE)...JAT sc AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX 859 AM CST TUE FEB 1 2005 .UPDATE... UPDATED PACKAGE WILL BE ISSUED ASAP TO REFLECT LATEST MESOSCALE TRENDS. LATEST ANALYSIS AND REGIONAL RADARS INDICATE AN ENHANCED BANDED STRUCTURE TO THE SNOWFALL FROM THE UPPER TRANS PECOS REGION TO THE NORTHERN PERMIAN BASIN. GRIDDED MODEL DATA SUGGEST THIS IS WELL CORRELATED TO INTENSE WAA/ISENTROPIC PROCESSES AND ASSOCIATED MID LEVEL FRONTOGENETICAL FORCING. VAPOR IMAGERY SHOWING WELL DEFINED BAROCLINIC LEAF DEVELOPING OVER THE WESTERN FA IN ADVANCE OF THE EJECTING MID/UPPER LEVEL LOW. GIVEN BANDED/SLANT-WISE CONVECTIVE RADAR SIGNATURES OVER THE NORTHWEST AND RECENT REPORTS OF 2-4 INCH ACCUMULATIONS BENEATH THIS BAND...WILL UPDATE PACKAGE TO REFLECT WARNING CRITERIA OVER THE NORTHWEST BASIN FAR SOUTHEASTERN NEW MEXICO PLAINS. && .PREV DISCUSSION... (ISSUED 330 AM CST TUE FEB 1 2005) SHORT TERM... UPPER LEVEL TROUGH EXTENDING DOWN ACROSS NEW MEXICO AND ARIZONA INTO MEXICO WILL BRING SNOW TO AREA TODAY. BEST CHANCE FOR HEAVY SNOW WILL BE JUST AHEAD OF STRONG SHORTWAVE ROUNDING THE BASE OF THE TROUGH THAT WILL MOVE UP INTO AREA THIS MORNING. ALREADY GETTING LIGHT PRECIP ACROSS THE TRANS PECOS AND WESTERN PERMIAN BASIN AHEAD OF A SHEAR AXIS THAT EXTENDS FROM THE SHORTWAVE OVER MEXICO UP ACROSS THE PANHANDLE. RUC SHOWS THAT BY 12Z SHORTWAVE WILL QUIT DIVING THROUGH BASE OF TROUGH AND START LIFTING NORTHEAST. CURRENTLY SITTING ON WINTER STORM WARNING FOR MAJORITY OF CWA WITH SNOW ADVISORY FOR NORTHWEST... WILL REISSUE. LATEST MODELS AND SATELLITE/RADAR DATA STILL POINTING TO A LARGE SNOW EVENT FOR AREA. GIVEN EXPECTED TRACK OF SHORTWAVE IT WOULD APPEAR THAT SOUTHERN CWA WOULD HAVE BEST SHOT AT HEAVY SNOWFALL TODAY. EXPECT TEMPS TO FALL TO NEAR FREEZING BY SUNRISE WITH LITTLE INCREASE THROUGH THE DAY... PERHAPS 5 DEGREES AT MOST. WITH ISENTROPIC LIFT AND UPPER LIFT AHEAD OF THE SHORTWAVE LOOK FOR SNOW TO INCREASE SIGNIFICANTLY BETWEEN 12Z AND 18Z... MOVING EAST AND TAPERING OFF THROUGH THE LATE AFTERNOON AND EVENING. AS OF 09Z ALREADY RECEIVING A FEW REPORTS OF LIGHT RAIN WEST WITH LIGHT SNOW AT GDP... AND RADAR COVERAGE INCREASING AND EXPANDING EASTWARD. PRECIP SHOULD CHANGE MORE TO SNOW BY MORNING BUT WILL HAVE TO DEAL WITH MIXED PRECIP TIL THEN. LIGHT DRIZZLE AND FALLING TEMPERATURES WILL BE ENOUGH TO CAUSE TRAVEL PROBLEMS EVEN BEFORE SNOW STARTS FALLING. HAVE EXPANDED HIGH POPS/HEAVIER SNOW TOTALS SOUTHWARD ACROSS LOWER TRANS PECOS AND WILL LEAVE LIKELY POPS NORTHWEST. SOME MODELS ARE MORE WIDESPREAD WITH THE SNOWFALL THAN OTHERS AND USUALLY IN THESE EVENTS SOME AREAS GET A LOT OF SNOW WHILE OTHER AREAS GET VERY LITTLE. THE MESO ETA TRIES TO KEEP MOST OF THE SNOW ALONG AND SOUTH OF I-20 WRAPPING IT ACROSS THE NORTHEAST LATER IN THE DAY. THIS SCENARIO WOULD ONLY SKIRT THE MIDLAND/ODESSA AREA WITH SNOWFALL... HOWEVER A SMALL DIFFERENCE IN TRACK OF SHORTWAVE CAN HAVE A BIG IMPACT ON HEAVIEST SNOW LOCATION... SO GIVEN EXPANDING RADAR COVERAGE WILL CONTINUE WINTER STORM WARNING AND SNOW ADVISORY TODAY FOR SAME COUNTIES...PLUS TERRELL. LONG TERM... BY WEDNESDAY...THE UPPER LEVEL STORM SYSTEM RESPONSIBLE FOR THE WINTRY WEATHER ON TUESDAY WILL BE NORTHEAST OF OUR AREA. WILL KEEP LOW ORDER POPS FOR WESTERN AREAS AS MORE ENERGY DIGS SOUTH THROUGH AZ WEDNESDAY MORNING ALLOWING FOR THE SLIGHT CHANCE OF LIGHT SNOW OVER THE GUADALUPE OR DELAWARE MOUNTAINS. TEMPERATURES WILL BEGIN WARMING SLOWLY BACK UP. WILL LEAVE HIGHS COLDER THAN GUIDANCE AS THEY ARE RIGHT NOW...SINCE WE ARE ANTICIPATING SNOWCOVER OVER MUCH OF THE AREA WHICH WOULD SLOW WARMING. BY THURSDAY...TEMPERATURES SHOULD RISE BACK UP TO NEAR NORMAL READINGS...AND THE SLOW WARMING WILL CONTINUE THROUGH THE WEEKEND UNDER WEAK MID AND UPPER LEVEL RIDGING. BY THE SECOND HALF OF THE WEEKEND...A CUT OFF LOW NEAR THE BAJA PENINSULA GETS PULLED NORTHEAST BY A NORTHERN STREAM SYSTEM...AND WILL MOVE ACROSS THE REGION DURING THE SUNDAY TIMEFRAME. AS THIS TROUGH OPENS AND MOVES NORTHEAST OVER THE AREA...THERE WILL BE A CHANCE FOR PRECIP. PLACEMENT OF PRECIP IS PROBLEMATIC THIS FAR OUT...SO WILL NOT INTRODUCE ANY WEATHER YET. ALSO WITH THIS WAVE...A PACIFIC FRONT WILL MOVE THROUGH...AND WESTERLY SFC WINDS WILL PICK UP SOMEWHAT. A NORTHERN STREAM TROUGH WILL MOVE ACROSS THE CENTRAL U.S. EARLY MONDAY WHICH WILL RESULT IN SURFACE RIDGING IN THE CENTRAL PLAINS AND SEND ANOTHER COLD FRONT INTO OUR CWA BY EARLY MONDAY MORNING. WILL TREND TEMPERATURES DOWN ON MONDAY FOR THIS. && .MAF WATCHES/WARNINGS/ADVISORIES... NM...WINTER STORM WARNING IN EFFECT FROM 6 AM UNTIL 6 PM CST TUESDAY FOR THE FOLLOWING ZONES...AND GUADALUPE MOUNTAINS OF EDDY COUNTY. SNOW ADVISORY IN EFFECT FROM 6 AM UNTIL 6 PM CST TUESDAY FOR THE FOLLOWING ZONES...CENTRAL LEA COUNTY...EDDY COUNTY PLAINS...NORTHERN LEA COUNTY...AND SOUTHERN LEA COUNTY. TX...SNOW ADVISORY IN EFFECT FROM 6 AM UNTIL 6 PM CST TUESDAY FOR THE FOLLOWING ZONES...ANDREWS...DAWSON...AND GAINES. WINTER STORM WARNING IN EFFECT FROM 6 AM UNTIL 6 PM CST TUESDAY FOR THE FOLLOWING ZONES...BIG BEND AREA...BORDEN...CRANE... DAVIS/APACHE MOUNTAINS AREA...ECTOR...GLASSCOCK... GUADALUPE MOUNTAINS...HOWARD...LOVING...MARFA PLATEAU... MARTIN...MIDLAND...MITCHELL...PECOS...REAGAN...REEVES COUNTY AND UPPER TRANS PECOS...SCURRY...TERRELL...UPTON... VAN HORN AND HIGHWAY 54 CORRIDOR...WARD...AND WINKLER. && $$ 67/21 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TOPEKA KS 327 PM CST WED FEB 2 2005 .DISCUSSION... SATELLITE AND PROFILERS HAVE H5 CIRCULATION OVER WESTERN OKLAHOMA AND UPPER LEVEL DIVERGENCE OVER EASTERN OKLAHOMA INTO SOUTHWEST MISSOURI AT 08Z. RADAR SHOWING LARGE AREA OF SNOW FROM EASTERN OKLAHOMA ACROSS SOUTHEAST KANSAS INTO SOUTHERN MISSOURI AT 09Z. RUC/NAM FORECAST HAS DONE VERY WELL WITH TRACKING THE SNOW ACROSS THE REGION THIS MORNING. WILL STAY THE LINE WITH THE RUC AND NAM FOR TODAY AND ONLY KEEP A MENTION OF FLURRIES IN FAR SOUTHEAST COUNTIES OF THE CWA AS MODELS KEEP THE FORCING TO OUR SOUTH THIS MORNING. NAM AND GFS BRING DRIER AIR INTO EASTERN KANSAS THIS AFTERNOON AND TONIGHT WHICH WILL BREAK UP THE LOW STRATUS OVER THE CWA. THE SOUTHEAST CORNER MAY STAY RELATIVELY CLOUDY FOR MOST OF THE DAY AND HAVE LOWERED MAXES THERE FOR TODAY. LITTLE CHANGE IN THE UPPER PATTERN WITH THE MAIN WESTERLIES ALONG THE NORTHERN BORDER AND RETROGRADING UPPER LOW OFF THE BAJA COAST FOR THE REST OF THE WEEK. THIS WILL KEEP US IN A DRY PATTERN AS HEIGHTS RISE INTO THE WEEKEND ACROSS THE CENTRAL PLAINS. UPPER LOW OVER THE SOUTHWEST MOVES OUT INTO THE PLAINS AS AN OPEN TROUGH ON SUNDAY. GENERALLY CONTINUED TO FOLLOW THE ECMWF WHICH STILL GIVES US A MIXED BAG OF RAIN AND SNOW ON SUNDAY AND SUNDAY NIGHT IN THE EAST CENTRAL WITH SNOW IN NORTHERN COUNTIES. AFTER SUNDAYS SYSTEM EXITS NEXT TROUGH MOVES INTO THE WESTERN PLAINS ON TUESDAY WITH A SURFACE LOW DEVELOPING OVER SOUTHWEST KANSAS. UPPER TROUGH MOVES ACROSS KANSAS ON TUESDAY WITH HIGH PRESSURE BUILDING IN BEHIND THE FRONT TUESDAY NIGHT. WARM ADVECTION KICKS IN MONDAY NIGHT BUT MOISTURE WILL BE POOLED INTO WESTERN KANSAS WITH UPSLOPE FLOW. EXPECT SOME LIGHT POPS ON TUESDAY IN WESTERN CWA AS UPPER TROUGH MOVES ACROSS THE STATE. && .TOP WATCHES/WARNINGS/ADVISORIES...NONE. && $$ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND 315 AM CST WED FEB 2 2005 .SHORT TERM...FORECAST CHALLENGE WILL BE CLOUD TRENDS TODAY AND TEMPERATURES THROUGHOUT. 00Z NAM/GFS INITIALIZED DECENT AND IN GENERAL AGREEMENT THROUGH 60HR. WILL UTILIZE NAM THROUGH 60HR...AND THEN GFS 60HR-84HR AS PER HPC GUIDANCE. CURRENT FORECAST IN GOOD SHAPE WITH ONLY MINOR ADJUSTMENTS NEEDED. TODAY...08Z SURFACE ANALYSIS SHOWS SFC TROUGH LOCATED ALONG EASTERN RED RIVER VALLEY. THIS FEATURE HAS MADE LITTLE PROGRESS EAST THE LAST FEW HOURS...AND FOLLOWING LATEST RUC/NAM WILL MOST LIKELY REMAIN RELATIVELY STATIONARY THROUGH 00Z UNTIL SYSTEM NORTH OF INTERNATIONAL BORDER KICKS IT EAST. THE MAIN EFFECT THIS WILL HAVE IS ON THE CLOUD COVER ALONG AND EAST OF A ROS-FSE-PKD LINE. EXPECT THESE CLOUDS TO MAKE ONLY SLOW PROGRESS EASTWARD TODAY...EXITING FORECAST AREA DURING THE AFTERNOON HOURS. WARM AIR ADVECTION GETS GOING TODAY WITH +2C TO +5C 925MB TEMPERATURES BY AFTERNOON. EXPECTED SOLAR AND SOME MIXING WILL HELP TEMPERATURES...WHILE SNOW COVER WILL HINDER. WITH THIS WILL GO WITH VALUES NEAR MOS GUIDANCE AS IT LOOKS REASONABLE. VALUES UNDER CLOUDS WILL UNDERGO LITTLE DIURNAL VARIATION AS IN PAST DAYS. CONDITIONS THROUGH FRIDAY WILL REMAIN SIMILAR. STORM TRACK REMAINS TO THE NORTH WITH MID-LEVEL SPLIT FLOW SCENARIO. TEMPERATURES WILL REMAIN MILD AS A SERIES OF DISTURBANCES ALONG NORTHERN STORM TRACK BRINGS QUICK SHOTS OF COLD AIR ADVECTION FOLLOWED BY WARM AIR ADVECTION. .LONG TERM (FRI NIGHT-WED)...GFS IS MORE PROGRESSIVE AND NORTH THAN NAM WITH SAT SYSTEM. HPC PREFERS THIS SCENARIO...AND CONSIDERING THE TREND TO THIS SOLUTION OVER THE LAST FEW MODEL RUNS THE GFS SEEMS REASONABLE. WITH THIS WILL NEED TO RAISE TEMPERATURES FRIDAY NIGHT AND SATURDAY. COLD AIR FOLLOWING SAT SYSTEM WILL MEAN NORMAL TEMPERATURES FOR REMAINDER OF LONG TERM. && .AVIATION...VFR CONDITIONS EXPECTED FOR GFK AND FAR. IFR/MVFR CLOUD CONDITIONS STILL HINDERING BJI. TOUGH TO SAY WHEN THESE CLOUDS WILL MOVE EAST OF SITE. SFC TROUGH CURRENTLY LOCATED ALONG EASTERN RED RIVER VALLEY WILL REMAIN NEARLY STATIONARY TODAY...AND NEED TO KICK THIS TROUGH EAST TO GET RID OF CLOUDS. WILL EVALUATE SITUATION OVER NEXT FEW HOURS...AND LIKELY GO WITH EARLY AFTERNOON TIMING IN 12Z TAF ISSUANCE. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ GRAFENAUER nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CLEVELAND OHIO 1230 AM EST WED FEB 2 2005 .AVIATION (06Z-06Z)... LARGELY A REPEAT OF LAST NIGHT WITH EXPANDING FG AND STRATUS. WL STAY WITH TREND OF WORSENING CONDS REST OF THE NIGHT WITH MOST PLACES DOWN TO A HALF MILE OR LESS VSBY IN FZFG SO EXPECT MORE HOAR FROST TO FORM ON EXPOSED SFCS. CI SHUD MOVE IN WED MORN AND MAY SLOW BURNOFF OF FG...ESP WRN AREAS WHERE CI ARRIVES FIRST. WNDS WL RMN LGT AND VRBL. && .SHORT TERM UPDATED (TONIGHT)... WL MAKE A FEW MINOR CHANGES TO FORECAST TEXT. WL REMOVE THE AFTER MIDNIGHT WORDING AS SOME DENSE FOG NOW BEGINNING TO FORM. RUC AND OTHER MODELS INDICATE THE BOUNDARY FLOW TO COME AROUND MORE FROM THE EAST OVERNIGHT AND THE DOWNSLOPE DRIER AIR MAY HELP KEEP DENSE FOG FROM BECOMING AS WIDESPREAD ALTHOUGH MOST AREAS WILL SEE AT LEAST MVFR TYPE FOG. SPREADING STRATUS WILL ALSO HELP SLOW THE RADIATING PROCESS SO WILL CONTINUE WITH A STATEMENT ABOUT AREAS OF DENSE FOG BUT WILL NOT ISSUE AN ADVISORY. WL LOWER MIN TEMPERATURES A BIT OR AT LEAST OPEN UP A RANGE AS JUST AS IN RECENT NIGHTS SOME AREAS WILL RADIATE MUCH BETTER THAN OTHERS AND WITH SNOW COVER SOME LOCATIONS WILL GET QUITE COLD AGAIN ALTHOUGH MOST LOWS SHOULD BE IN THE TEENS TO AROUND 20. UPDATE AT 945 PM && .PREVIOUS DISCUSSION FROM 311 PM... SHORT TERM (TONIGHT THRU THURS)... FOG WILL ONCE AGAIN BE A PROBLEM ACROSS THE AREA TONIGHT AS HIGH PRESSURE CENTERS OVER THE REGION. CURRENT STRATUS AND FOG QUICKLY DISSIPATING THIS AFTERNOON AND THIS WILL ALLOW SKIES TO CLEAR THROUGH THE EARLY EVENING. HOWEVER...INVERSION WILL SETTLE BACK DOWN THIS EVENING TRAPPING LOW LEVEL MOISTURE NEAR THE SURFACE FROM LAKE ERIE IN LIGHT EAST TO NORTHEAST FLOW. NGM MODEL SUGGESTS LOW LEVEL FLOW WILL BECOME SOUTHEAST OVERNIGHT AND IF THIS SCENARIO SETS UP THEN SUBSIDENCE MAY HELP KEEP DENSE FOG FROM FORMING NEAR THE LAKE SHORE FROM LAKE COUNTY TO ERIE COUNTY PA. THE REST OF THE MODELS INDICATE WINDS WILL BECOME LIGHT AND VARIABLE. I AM EXPECTING SOME AREAS OF DENSE FOG TO DEVELOP AGAIN TONIGHT...ESPECIALLY AWAY FROM THE LAKE AND OVER THE TOLEDO TO FINDLAY AREA. TEMPERATURES WILL DROP INTO THE 20S AND TEENS AGAIN TONIGHT...I WOULD EXPECT FREEZING FOG TO GLAZE EXPOSED UNTREATED SURFACES AND CAUSE PROBLEMS OVERNIGHT INTO WEDNESDAY MORNING. USERS WITH PUBLIC ACCESS...WILL YOU PLEASE HIGHLIGHT THIS PROBLEM SINCE TRAVEL MAY BECOME DIFFICULT OVERNIGHT AGAIN. I WILL ISSUE A SPECIAL WEATHER STATEMENT MENTIONING THE FREEZING FOG AS WELL. FOG AND STRATUS WILL EVENTUALLY BURN OFF DURING THE MORNING HOURS WEDNESDAY AS THE HIGH PRESSURE SYSTEM SHIFTS SLOWLY EAST OF THE AREA AND WEAK UPPER LEVEL RIDGE DOMINATES THE AREA THROUGH THE DAY. DEPENDING ON WHERE OUR RODENT PROGNOSTICATORS WILL BE TOMORROW ACROSS THE FORECAST AREA...THERE IS THE POSSIBILITY THAT SOME MAY PREDICT AN EARLY END TO WINTER IF THEY ARE UNDER THE STRATUS DECK AND OTHERS SAY SPRING WILL LAST SIX MORE WEEKS IF THEY SEE THE SUN. AN UPPER LEVEL LOW PRESSURE SYSTEM AND ITS ASSOCIATED VORT MAX WILL MOVE EAST ACROSS KENTUCKY AND WEST VIRGINIA THURSDAY. SURFACE LOW IS PROGGED TO STAY WELL SOUTH OF THE AREA KEEPING THE FORECAST AREA DRY. TEMPERATURE GUIDANCE HAS BEEN RUNNING A BIT WARM IN LAST FEW RUNS DUE TO EXPECTANT SUNSHINE BUT WITH STRATUS AND FOG LINGERING INTO THE EARLY AFTERNOON...TEMPERATURES ARE BEING HELD AT BAY. WILL LOWER MAXIMUM TEMPERATURES FOR TOMORROW A TAD TO AROUND 30 IN THE WEST AND LOWER 30S ELSEWHERE. && .LONG TERM (FRI THRU TUES)... MASSIVE UPPER LEVEL RIDGE AND SURFACE HIGH PRESSURE SYSTEM WILL BUILD ACROSS THE FORECAST AREA FRIDAY THROUGH SUNDAY. WARMING TEMPERATURES CAN BE EXPECTED SUNDAY INTO SUNDAY NIGHT AHEAD OF A STORM SYSTEM PROGGED TO MOVE NORTHEAST UP THE MISSISSIPPI VALLEY REGION. COLD FRONT WILL MOVE INTO THE AREA MONDAY EVENING USHERING IN COLDER TEMPERATURES AND A RETURN BACK TO SNOW BY TUESDAY. PROBLEMS TO LOOK OUT FOR DURING THE EXTENDED PERIODS IS THE POTENTIAL FOR A RETURN TO FLOODING SITUATIONS. WET BULB ZERO TEMPERATURES ARE EXPECTED TO RISE WELL ABOVE ZERO SUNDAY NIGHT INTO MONDAY MORNING. WARM SOUTH TO SOUTHWEST FLOW AT 10 TO 20 KNOTS WILL HELP MELT SNOW PACK IN PLACE. SOIL TEMPERATURES LIKELY TO BE FROZEN WITHIN FIRST INCH OR SO SINCE SNOW HAS INSULATED THE SOIL FROM FRIGID COLD TEMPERATURES OVER THE LAST COUPLE WEEKS. RAINFALL EXPECTED WITH THE COLD FRONT WILL BE IN ADDITION TO APPROXIMATELY ONE INCH OF LIQUID LOCKED UP IN THE SNOW PACK AT THIS TIME. COMBINATION OF SNOW AND RAIN WILL RESATURATE THE SOILS CAUSING RUNOFF TO OCCUR. DEPENDING ON HOW WARM WE GET AND HOW MUCH RAIN FALLS WITH THE WARM FRONT AND COLD FRONT...IT STILL REMAINS A QUESTION ON HOW THIS WILL AFFECT ICE THAT HAS DEVELOPED ON THE RIVERS. WE WILL CONTINUE TO MONITOR THIS SITUATION CLOSELY THROUGH THE WEEK INTO THE WEEKEND AS IT DEVELOPS. OTHERWISE...AS MENTIONED TEMPERATURES EXPECTED TO WARM UP THROUGH THE WEEKEND BUT WARM UP SHOULD BE SHORT LIVED AND PLUNGE TEMPERATURES BACK TO BELOW FREEZING TUESDAY SHUTTING DOWN RUNOFF. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE && UPDATED SHORT TERM...KOSARIK SHORT TERM...LOMBARDY LONG TERM...LOMBARDY AVIATION...MWA $$ oh WEST CENTRAL AND SOUTHWEST FLORIDA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL 930 AM EST WED FEB 2 2005 .DISCUSSION...MID AND HIGH CLOUDS CONTINUING TO STREAM ACROSS THE NORTHERN AND CENTRAL PORTIONS OF THE FORECAST AREA THIS MORNING WITH SOME LOW CLOUDS AND FOG LIFTING AND DISSIPATING ACROSS THE SOUTH. RADAR INDICATING A FEW SHOWERS MOVING ACROSS NORTH FLORIDA AND NORTHEAST GULF OF MEXICO INTO THE NATURE COAST...BUT THESE ARE LIGHT AND GENERALLY FALLING APART AS THEY MOVE FURTHER EAST. SURFACE HIGH IS NOSING DOWN THE EAST COAST INTO FLORIDA WITH LOW LEVEL EAST NORTHEAST FLOW ACROSS THE REGION HELPING TO KEEP LOWEST LEVELS A LITTLE DRIER. IN GENERAL WILL SEE A LOT OF CLOUDS ACROSS THE NORTHERN HALF OF THE REGION WITH A FEW SHOWERS MOVING ACROSS THE NATURE COAST THIS AFTERNOON. AREA OF RAIN OVER FLORIDA PANHANDLE WILL LIKELY MOVE INTO NORTHERN AREAS TOWARD EVENING. ACROSS THE SOUTHERN HALF EXPECT PARTLY SUNNY SKIES AND LITTLE IF ANY CHANCE OF RAIN. WILL THEREFORE UPDATE ZONES AND LOWER RAIN CHANCES ACROSS THE NORTHERN AND CENTRAL COUNTIES AND REMOVE FROM SOUTHERN COUNTIES. NO OTHER CHANGES PLANNED AT THIS TIME. && .MARINE...GENERALLY AN EASTERLY FLOW AT 10 TO 15 KNOTS ACROSS THE COASTAL WATERS AT THIS TIME. LATEST RUC INDICATING A CONTINUATION OF THIS FLOW THROUGH THE AFTERNOON...EXCEPT ACROSS SOUTHERN LEG WHERE FLOW COULD BE LIGHT ENOUGH TO ALLOW A SEA BREEZE TO DEVELOP WITH DAYTIME HEATING. THIS ALL SEEMS REASONABLE BASED ON LOCATION OF HIGH TO THE NORTH AND DEVELOPING LOW PRESSURE TO THE NORTHWEST AND WILL ADJUST MARINE FORECAST ACCORDING FOR LATE MORNING FORECAST. NO OTHER MAJOR CHANGES PLANNED. && .TBW WATCHES/WARNINGS/ADVISORIES...NONE. && $$ PRC fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1105 AM EST WED FEB 2 2005 .DISCUSSION... THE MAIN CONCERN WITH THIS UPDATE IS THE TEMPERATURES FOR THIS AFTERNOON. WATER VAPOR IMAGERY AND RUC/ETA SHOW A ZONAL FLOW ACROSS SOUTHERN CANADA. A WEAK SHORTWAVE CAUGHT IN THIS FLOW IS OVER NORTHWEST ONTARIO AND NORTHERN MINNESOTA. ANOTHER WEAK SHORTWAVE IS OVER NORTHERN LOWER MICHIGAN. MORNING RAOBS AND FORECAST SOUNDINGS INDICATE RH AROUND 90 PERCENT FROM SURFACE TO 900HPA. THE LOWEST INVERSION LEVEL IS AROUND 950HPA PRODUCING EXTENSIVE CLOUD COVER. A DEEP TROUGH EXTENDS FROM THE UPPER MISSISSIPPI RIVER VALLEY SOUTHWEST INTO ARIZONA. SURFACE ANALYSIS SHOWING A LOW OVER NORTHERN MANITOBA WITH A WEAK TROUGH RUNNING SOUTH INTO THE NORTHERN PLAINS OF CONUS. A RIDGE STRETCHES FROM A HIGH OVER MAINE SOUTHWEST ACROSS THE LOWER GREAT LAKES INTO CENTRAL MISSISSIPPI RIVER VALLEY. THE SHORTWAVE OVER MINNESOTA WILL EDGE INTO WESTERN LAKE SUPERIOR THIS AFTERNOON. THE RIDGE OVER LOWER MICHIGAN AND LOWER GREAT LAKE WILL SLOW THE PROGRESS OF THE SHORTWAVE OVER THE NORTHERN PLAINS. THIS IN TURN WILL SLOW THE PROGRESSION OF THE SURFACE TROUGH. WIND WILL REMAIN OUT OF THE SOUTHWEST OF THE FORECAST AREA THIS AFTERNOON. RH BELOW 900HPA WILL BE AROUND 90 PERCENT THROUGH THE AFTERNOON. THE LOW LEVEL WILL CONTINUE TO REMAIN MIXED THIS AFTERNOON...KEEPING LOW CLOUDS PRESENT EARLY. THE MODELS AND VISIBLE IMAGERY SHOWING SOME DRIER AIR MOVING INTO THE WESTERN U.P. THIS AFTERNOON...WHICH WILL CAUSE SOME BREAKS IN THE CLOUDS COVER...BEFORE THE SHORTWAVE ENTER INTO WESTERN LAKE SUPERIOR. THUS MIST SHOULD CONTINUE THROUGH THE AFTERNOON UNDER THE INVERSION. THE VISIBILITY WILL BE SUCH TO REMAIN ABOVE 1 MILES SO WILL NOT MENTION IT IN THE FORECAST AT THIS TIME. A BLANKET OF CLOUDS WILL MODERATE THE TEMPERATURE AND LIMIT HEATING. THUS ONLY TWEAK A FEW TEMPERATURES AND CHANGE MOSTLY CLOUDY TO A MIX OF SUN AND CLOUDS. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DLG mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND 509 AM CST WED FEB 2 2005 .UPDATE...WILL NEED TO UPDATE GRIDS/ZONES TO MENTION PATCHY DENSE FOG FOR THE MORNING HOURS ALONG AND EAST OF A ROX-TVF-FAR LINE. SURFACE TROUGH LOCATED ALONG THIS LINE WITH FOG FORMATION TO 1/4SM ALONG TROUGH. DON/T EXPECT DENSE FOG TO BECOME TOO WIDESPREAD...BUT WILL MONITOR. PREVIOUS DISCUSSION... .SHORT TERM...FORECAST CHALLENGE WILL BE CLOUD TRENDS TODAY AND TEMPERATURES THROUGHOUT. 00Z NAM/GFS INITIALIZED DECENT AND IN GENERAL AGREEMENT THROUGH 60HR. WILL UTILIZE NAM THROUGH 60HR...AND THEN GFS 60HR-84HR AS PER HPC GUIDANCE. CURRENT FORECAST IN GOOD SHAPE WITH ONLY MINOR ADJUSTMENTS NEEDED. TODAY...08Z SURFACE ANALYSIS SHOWS SFC TROUGH LOCATED ALONG EASTERN RED RIVER VALLEY. THIS FEATURE HAS MADE LITTLE PROGRESS EAST THE LAST FEW HOURS...AND FOLLOWING LATEST RUC/NAM WILL MOST LIKELY REMAIN RELATIVELY STATIONARY THROUGH 00Z UNTIL SYSTEM NORTH OF INTERNATIONAL BORDER KICKS IT EAST. THE MAIN EFFECT THIS WILL HAVE IS ON THE CLOUD COVER ALONG AND EAST OF A ROX-FSE-PKD LINE. EXPECT THESE CLOUDS TO MAKE ONLY SLOW PROGRESS EASTWARD TODAY...EXITING FORECAST AREA DURING THE AFTERNOON HOURS. WARM AIR ADVECTION GETS GOING TODAY WITH +2C TO +5C 925MB TEMPERATURES BY AFTERNOON. EXPECTED SOLAR AND SOME MIXING WILL HELP TEMPERATURES...WHILE SNOW COVER WILL HINDER. WITH THIS WILL GO WITH VALUES NEAR MOS GUIDANCE AS IT LOOKS REASONABLE. VALUES UNDER CLOUDS WILL UNDERGO LITTLE DIURNAL VARIATION AS IN PAST DAYS. CONDITIONS THROUGH FRIDAY WILL REMAIN SIMILAR. STORM TRACK REMAINS TO THE NORTH WITH MID-LEVEL SPLIT FLOW SCENARIO. TEMPERATURES WILL REMAIN MILD AS A SERIES OF DISTURBANCES ALONG NORTHERN STORM TRACK BRINGS QUICK SHOTS OF COLD AIR ADVECTION FOLLOWED BY WARM AIR ADVECTION. .LONG TERM (FRI NIGHT-WED)...GFS IS MORE PROGRESSIVE AND NORTH THAN NAM WITH SAT SYSTEM. HPC PREFERS THIS SCENARIO...AND CONSIDERING THE TREND TO THIS SOLUTION OVER THE LAST FEW MODEL RUNS THE GFS SEEMS REASONABLE. WITH THIS WILL NEED TO RAISE TEMPERATURES FRIDAY NIGHT AND SATURDAY. COLD AIR FOLLOWING SAT SYSTEM WILL MEAN NORMAL TEMPERATURES FOR REMAINDER OF LONG TERM. && .AVIATION...VFR CONDITIONS EXPECTED FOR GFK AND FAR. IFR/MVFR CLOUD CONDITIONS STILL HINDERING BJI. TOUGH TO SAY WHEN THESE CLOUDS WILL MOVE EAST OF SITE. SFC TROUGH CURRENTLY LOCATED ALONG EASTERN RED RIVER VALLEY WILL REMAIN NEARLY STATIONARY TODAY...AND NEED TO KICK THIS TROUGH EAST TO GET RID OF CLOUDS. WILL EVALUATE SITUATION OVER NEXT FEW HOURS...AND LIKELY GO WITH EARLY AFTERNOON TIMING IN 12Z TAF ISSUANCE. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ GRAFENAUER nd AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 1027 AM CST WED FEB 2 2005 .DISCUSSION... ELEVATION EFFECTS CLEARLY DISCERNABLE THIS MORNING...WITH VALLEYS LAGGING HIER SPOTS THERMALLY. LOW LVL MOISTURE SHALLOWED OUT QUITE A BIT OVERNIGHT...DEEPER FETCH INTO NW IA AND SW MN WHERE RESIDUAL STRATUS/FOG WELL INTO THE DISSIPATION PROCESS. REMAINING SPOTTY CLOUDS ALG SW UPSLOPE FAVORED REGION OF SW MN...AND IN DEEPER MOISTURE AXIS NW IA. BLO INVERSION LAPSE SUGGESTS SOME SC REDEVELOPMENT POTENTIAL. NAM HAS COME INTO LINE WITH SLIGHTLY WARMER GFS/RUC ON 925 TMPS... SO AGAIN COMPELLED TO BUMP TMPS UP A BIT ACRS MANY LOCALES... GREATEST IN W AND IN DOWNSLOPE FAVORED SW MN AREAS. UPDATED ZFP/GRIDS ISSUES EARLIER...AND MAY TWEEK A BIT FOR TRENDS AGAIN SOON. && .PREV DISCUSSION... MRNG FOG/LO CLDS NWRN IA INTO SERN PART OF SWRN MN...THAT IS OTG/MJQ/MWM...SHUD BE MIXED OUT BEFORE NOON. OTRW WITH ONLT WK BAND OF HI CLDS ARND SKIES SHUD GO TO MOSUNNY. CLR TO PTCLDY PATTRN SHUD CONT THRU FRI AS UPR RDGNG BLDS IN STGR WITH A BAND OR TWO OF MID/HI CLDS AGN MOVG OVER AREA TNGT INTO THU AND AGN FRI. SOME INCRS IN CLDS SAT AS CDFNT APPCHS BUT SHUD STILL BE PTCLDY DURG DAY. TEMPS GETTNG PRETTY WARM TDA AND WRMR THU THRU FRI. GUIDNCE HAS RIGHT IDEA BUT MAY NOT BE QUITE THERE ON MAX TEMPS WITH NO SNW CVR AND DECENT SUNSHINE...NOW THE FEB SUN. TIMING OF CDFNT STILL IN SOME DOUBT BUT WILL PLAY CLOSE TO WHAT WE HAVE WHICH IS CLOSE TO 00Z GFS AND BRING IT THRU SAT NGT. WILL KEEP THREAT OF LGT SNW BAND DVLPG IMMEDIATELY BHND FNT THO HAVE SOME DOUBTS ABT SUCH QUICK DVLPMNT. KEEPING LGT SNW CHC FOR SUN. MAIN CHANGE IN EXTNDED IS TO HIT SNW CHC BETTER MON AND EXTND INTO MON NGT. THO FAR ENUF DOWN THE ROAD...MODELS SHOW A LTL BETTER THAN USUAL CONSISTENCY...MOST NOTABLY CANADIAN MATCHING UP WITH GFS SURPRISINGLY WELL. WHILE NOT ALL IN PLACE...ENUF CHC OF DECENT SNOW MON TO CHUCK THE LIGHT DESIGNATION AND GO TO THE TOP OF THE CHC CATEGORY. THO NOT CERTAIN...STILL SEEMS REANBL TO CLR OUT THE SNW CHC BY TUE...AND KEEP IT DRY WED...THE COMING DAY 7. WILL CONT TO PLAY THE COLD AIR MODERATELY...THAT IS AT WORST SLGTLY COLDR THAN NRML. FEEL IT CUD BE COLDER BUT EVEN WHAT WE HAVE WILL BE QUITE A BIG CHANGE FROM THE BALMY GOLF TYPE WX NEXT THREE DAYS. WILLIAMS/RYRHOLM && .AVIATION... RESIDUAL IFR STRATUS/FOG BECOMING MUCH MORE LIMITED IN COVERAGE MID MORNING...WITH REMAINING AREAS MAINLY FOCUSED ALG HIER TERRAIN OF SW MN FAVORING SW UPSLOPE WNDS...AND WK CONVERGENCE AXIS THRU NW IA FM KOTG TO KSUX. FM 16Z-18Z AREAS ARE EXPECTED TO DISSIPATE...WITH SOME MARGINAL MVFR/VFR SC ACRS ERN PORTIONS OF TWB302 THRU 20Z. && FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ CHAPMAN sd