AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 249 PM MDT SAT SEP 9 2006 .SHORT TERM... (TONIGHT AND SUNDAY) MAIN FORECAST CHALLENGE WILL BE TIMING ON PRECIPITATION. MAXIMUM TEMPERATURES STILL RUNNING SLIGHTLY BELOW EARLY SEPTEMBER AVERAGES. CURRENTLY...SOMEWHAT FLATTER MIDDLE AND UPPER LEVEL WESTERLY FLOW OVER THE CENTRAL ROCKIES THIS MORNING AND EARLY AFTERNOON PER WATER VAPOR IMAGERY AND RUC MODEL UPPER AIR ANALYSES. THE RUC H5-H3 LAYER VORTICITY DATA SHOWED A SHORTWAVE TROUGH MOVING ALONG THE WY/CO BORDER AND ANOTHER WAY BACK OVER NV. NO PRECIPITATING WEATHER THIS MORNING AND THE WRF MODEL HAS BEEN DEVELOPING PRECIPITATION TOO EARLY. VIS AND IR SATELLITE IMAGERY SHOWING CU AND TOWERING CU DEVELOPING OVER THE MOUNTAINS...ESPECIALLY THE CONTINENTAL DIVIDE EARLY THIS AFTERNOON. A FEW SHOWERS ARE BREAKING OUT OVER CENTRAL MOUNTAINS...BUT NOT MUCH DEVELOPING OVER OUR EASTERN MOUNTAINS EARLY THIS AFTERNOON. CAPPING INVERSION STILL KEEPING TOWERING CU AND CB DEVELOPMENT AT MINIMUM EARLY THIS AFTERNOON. REGIONAL RADAR SHOWING A LINE OF SHRA/TSRA FORMING OVER PALMER DIVIDE AND HAS GONE SEVERE JUST IN EL PASO COUNTY. THIS IS CLOSER TO THE MIDLEVEL SHORTWAVE AND SOUTHWARD EXTENDING CYCLONIC SHEAR AXIS PER WATER VAPOR IMAGERY. LATE NIGHT AND EARLY MORNING STRATUS/FOG DISSIPATED ACROSS THE SAN LUIS VALLEY AND MUCH OF SOUTHEASTERN CO BY MIDMORNING. TONIGHT...MIDDLE AND UPPER LEVEL WESTERLY FLOW TO CONTINUE AND IT IS DIFFICULT TO LATCH ONTO ANY SIGNIFICANT MIDLEVEL SHORTWAVE TO ENHANCE CONVECTION. WILL LIKELY SEE ISOLATED TO SCATTERED SHOWERS AND A FEW THUNDERSTORMS CONTINUE TO DEVELOP OVER THE MOUNTAINS AND HIGH VALLEYS LATE THIS AFTERNOON AND MOVE TOWARDS THE EAST THIS EVENING. JUST CANNOT JUSTIFY THE 12KM WRF HANGING ONTO PRECIPITATION ACROSS PORTIONS OF THE CWFA AFTER MIDNIGHT...EXCEPT MAYBE THE FAR SOUTHEASTERN CO DUE TO SOME ROGUE THUNDERSTORM OUTFLOW BOUNDARY...BUT THAT MIGHT BE A STRETCH. WILL MAINTAIN ISOLATED TO SCATTERED SHOWERS AND A FEW THUNDERSTORMS ACROSS MUCH OF THE CWFA WITH THE HIGHEST POPS/WX ACROSS THE MOUNTAINS AND HIGH VALLEYS. MUCH OF THE PRECIPITATION POTENTIAL SHOULD BE OVER AFTER MIDNIGHT AS THE CONVECTIVE DEBRIS CLOUDS DISSIPATE. THERE MIGHT BE SOME THIN HIGH CLOUDS MOVING OVERHEAD LATE. A LITTLE CONCERNED ABOUT ANOTHER ROUND OF STRATUS/FOG ACROSS THE SAN LUIS VALLEY AND SOUTHEASTERN CO PLAINS. 12KM WRF IS NOT AS MOIST NEAR THE SURFACE AS WITH LATE LAST NIGHT AND EARLY THIS MORNING. TOUGH CALL AND WILL MAKE IT AT PRESS TIME. IF IT RAINS IN THE SAN LUIS VALLEY...THEN THE NIGHTTIME SFC-PBL COULD MOISTEN WITH LIFR/IFR STRATUS/FOG CONDITIONS. A WEAK COLD FRONT MOVES THROUGH SOUTHEASTERN CO LATE TONIGHT. THERE IS SOME HINT OF SFC-PBL MOISTENING BEHIND THE WEAK FRONT TO SUPPORT STRATUS/FOG DEVELOPMENT TOWARDS SUNRISE. SUNDAY...AGAIN...12KM WRF IS LIKELY DEVELOPING PRECIPITATION TOO EARLY(E.G. MORNING)...ESPECIALLY IN SOUTHEASTERN CO. AGAIN...TOUGH TO CONCENTRATE ON ANY SIGNIFICANT SHORTWAVE TROUGH IN THE MODELS TO ENHANCE CONVECTION ON SUNDAY. DISSIPATING WEAK COLD FRONT IN SOUTHEASTERN CO WILL LIKELY TRANSITION TO EASTERLY UPSLOPE FLOW...MOUNTAIN-PLAINS CIRCULATION...ACROSS I-25 CORRIDOR AND EASTWARD. THIS MIGHT ACTUALLY KNOCK A FEW DEGREES OF THE TEMPERATURE...UNLESS DEEPER MIXING CAN OCCUR. GETTING CLOSE AND INTO FALL...SO GETTING TOUGHER FOR SOUTHEAST CO TO MIX AND WARMUP...SO MOS MIGHT BE A LITTLE TOO WARM. IF IT REMAINS COOLER...THEN LOW LEVEL CAPPING INVERSION WOULD KEEP SURFACE-BASED SHRA/TSRA FROM FORMING SUNDAY AFTERNOON. HOWEVER... ISOLATED TO SCATTERED SHRA/TSRA COULD FORM OVER THE MOUNTAINS AND DRIFT EASTWARD GIVEN THE WESTERLY MEAN LAYER FLOW. METZE .LONG TERM... (SUNDAY NIGHT THROUGH SATURDAY) SUNDAY NIGHT-MONDAY...LATEST MODELS COMING CLOSER TOGETHER WITH DEVELOPING NORTH TO NORTHWEST FLOW ALOFT ACROSS THE REGION AS BROAD UPPER LOW/TROUGH MOVES ACROSS THE NORTHERN HIGH PLAINS AND INTO THE UPPER MIDWEST THROUGH TUESDAY. PASSING SYSTEM SENDS A RE ENFORCING SURGE OF COOL AIR ACROSS THE EASTERN PLAINS LATE SUNDAY NIGHT WITH COOL UPSLOPE FLOW EXPECTED ON MONDAY. WITH NORTH TO NORTHEAST SFC-H7 FLOW ACROSS THE PLAINS AND WEAK QG IMPLIED ASCENT PROGGED ACROSS THE REGION...HAVE INCREASED POPS ACROSS THE FAVORED EASTERN TERRAIN SUNDAY NIGHT AND MONDAY. HAVE ALSO LEANED CLOSER TO THE COOLER NAM GUIDANCE FOR MONDAY...KEEPING THE FAR EASTERN PLAINS TOO STABLE ON MONDAY. TUESDAY-WEDNESDAY...UPPER LEVEL RIDGING ACROSS THE GREAT BASIN ON TUESDAY FLATTENS ACROSS THE STATE WEDNESDAY AS LARGE SYSTEM DEVELOPING ACROSS EPAC BEGINS TO MOVE INTO THE PAC NW COAST. WITH WEAK NORTHERLY FLOW ACROSS THE STATE TUESDAY...ALONG WITH SOME AVAILABLE MOISTURE...HAVE KEPT ISOLATED DIURNAL POPS CONFINED THE MAINLY THE HIGHER TERRAIN ON TUESDAY. LATEST GFS SEEMS TO BE OVERDONE WITH PRECIP ON WEDNESDAY AND WILL KEEP ISOLATED DIURNAL POPS IN TACT ACROSS THE MTS. THURSDAY-SATURDAY...OPERATIONAL MODELS SLOWLY COMING CLOSER TOGETHER WITH EACH OTHER AND NCEP ENSEMBLE MEANS...WITH DEEP UPPER LOW DEVELOPING ACROSS THE PAC NW COAST THROUGH FRIDAY AND THEN DIVERGE WITH LATEST GFS MOVING SYSTEM ACROSS THE NORTHERN ROCKIES SATURDAY WHILE LATEST ECMWF KEEPING DEEP LOW ACROSS THE PAC NW COAST. AT ANY RATE...PATTERN FAVORS KEEPING GENERALLY WARM AND DRY WEST TO SOUTHWEST FLOW ACROSS THE STATE...AND HAVE NOT DEVIATED MUCH FROM PREVIOUS FORECAST ATTM. -MW && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 17/23 co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSONVILLE FL 912 AM EDT SAT SEP 9 2006 .UPDATE...12Z SOUNDING AND MORNING WATER VAPOR IMAGERY INDICATES SOMEWHAT ACTIVE ZONAL FLOW ALOFT WITH WEAK SHORTWAVES MOVING THROUGH THE AREA IN RATHER LIGHT WESTERLIES. AT THE SFC...HIGH PRESSURE ANCHORED NORTHEAST OF THE AREA PRODUCING SOME NORTHEAST FLOW OVER THE COASTAL WATERS AND INTO NORTHEAST FLORIDA AND SOUTHEAST GEORGIA. PRETTY GOOD BLOWUP OF CONVECTION SEEN WELL OFFSHORE ASSOCIATED WITH EXITING SHORTWAVE. SCATTERED WEAKER CONVECTION NOTED OVER THE NORTHEAST GULF. 06Z GFS IS VERY AGRESSIVE BRINGING A SHORWAVE FROM THE NE GULF ACROSS THE CWA THIS AFTERNOON WITH ANOTHER FOLLOWING OVERNIGHT. RUC AND 00Z NAM ARE MUCH LESS AGRESSIVE WITH THESE SHORTWAVES. RUC ANALYSIS AND WATER VAPOR IMAGERY ARE MUCH MORE SUPPORTED OF THE WEAKER SOLUTIONS. THUS WITH NORTHEAST LOW LEVEL FLOW...EXPECT BEST COVERAGE OF CONVECTION OVER SOUTHWESTERN CWA THIS AFTERNOON. 0-6KM FLOW IS VERY LIGHT SO EXPECT SLOW MOVEMENT WITH THE CONVECTION AND LOCALLY HEAVY RAINFALL POSSIBLE. COASTAL NE FLORIDA MAY SEE A FEW LOW TOPPED SHOWERS THROUGH THE REST OF THE MORNING BUT WILL LIKELY DRY OUT SOME THIS AFTERNOON WITH ONLY ISOLATED STORMS. TEMPS SHOULD REMAIN IN THE 80S TODAY WITH NORTHEAST LOW LEVEL FLOW. && .MARINE...AS HIGH PRESSURE BUILDS NORTH OF THE WATERS...NORTHEAST FLOW WILL BE ON THE INCREASE THIS AFTERNOON REACHING CLOSE TO 15 KNOTS THIS AFTERNOON. SEAS WILL BE ON THE INCREASE...INITIALLY FROM THE NORTHEAST FLOW...BUT WILL ALSO BEGIN TO SEE LONG PERIOD SWELLS APPROACH FROM T.S. FLORENCE BY LATE THIS AFTERNOON AND ESPECIALLY INTO SUNDAY. && .AVIATION...VFR CONDITIONS TO PREVAIL THROUGH REMAINDER OF THE MORNING BEFORE CLOUDINESS DEVELOPS EARLY IN THE AFTERNOON. PLENTY OF LOW LEVEL MOISTURE AND NORTHEAST WINDS FCST TO LEAD TO MVFR CONDITIONS FOR COASTAL SITES. ONLY ISOLATED TSRA EXPECTED ALONG THE COAST WITH A LITTLE MORE COVERAGE EXPECTED FOR KGNV. WILL MONITOR KGNV FOR POSSIBLE UPGRADE TO TEMPO TSRA FOR THE AFTERNOON. OTHERWISE...MAINLY VFR CONDITIONS EXPECTED OVERNIGHT TONIGHT. && .JAX WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. MARINE...NONE. && $$ CAMP/ZIBURA fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LOUISVILLE KY 1000 AM EDT SAT SEP 9 2006 .MORNING UPDATE... LOOKING AT VIS SAT...FOG LOCATED ALONG WATERWAYS...AREAS WITH RECENT PRECIP AND NEAR VALLEYS LOCATIONS WAS BURNING OFF QUICKLY. THUNDERSHOWER ACTIVITY HAD LESSENED FROM ITS ALREADY ISOLATED NATURE AS OF 930 AM. LITTLE VORT ROLLING ACROSS TENNESSEE HELPING TO FIRE UP THE ACTIVITY EARLIER THIS MORNING...AND IT SHOULD REDEVELOP AGAIN ACROSS THE SOUTHERN PORTIONS OF THE FORECAST AREA LATER THIS AFTERNOON DUE TO HEATING CREATING AMPLE INSTABILITY...LIS NEARING -3 TO -5 AND CAPES AROUND 1500-2000 J/KG. AS MENTIONED EARLIER...DRIER AIR ALOFT MAY ALLOW FOR GUSTY WINDS IN STORMS...AND SMALL HAIL AND HEAVY RAIN MAY BE AN ISSUE AS WELL...THOUGH COVERAGE WILL BE LESS THAN 20 PERCENT OF THE AREA TO SEE ANY RAINFALL TODAY. ANY STORMS THAT DEVELOP SHOULD REMAIN SOUTH OF A LINE FROM RICHMOND TO HODGENVILLE TO MORGANTOWN. ONE THING OF NOTE...THE 12Z RUN OF THE RUC SHOWS THE TN VORT SLIDING INTO EASTERN TN BY LATE AFTERNOON...SO THINKING THAT THE SOUTHEASTERN PORTIONS OF THE AREA (LAKE CUMBERLAND/DALE HOLLOW AREAS) WILL HAVE THE BEST CHANCES OF A STORM THIS AFTERNOON AS WARMER MID LEVEL TEMPS MOVING INTO THE WESTERN PORTIONS OF THE AREA DURING THE AFTERNOON MAY PROVIDE FOR SOME SLIGHT CAPPING TO THE CONVECTION. HOURLY TEMPS LOOK GOOD SO FAR...ALL WITHIN A DEGREE OR SO...WILL NOT MAKE MUCH IF ANY SIGNIFICANT ADJUSTMENT HERE...THOUGH LEX IS SLIGHTLY HIGHER THAN BOTH SDF/BWG AS OF 10 AM. A FEW TO SCTD CU WILL DEVELOP AGAIN THIS AFTERNOON...LESSER COVERAGE AS YOU MOVE TOWARDS AND NORTH OF THE OHIO RIVER. --SCHOTT PREVIOUSLY ISSUED DISCUSSION AT 307 AM EDT SAT SEP 9 2006 SHORT TERM (TODAY AND TONIGHT)... MAIN FORECAST CHALLENGE WILL BE CHANCE...IF ANY...OF THUNDERSTORMS THIS AFTERNOON AND EVENING. GFS SHOWS A WEAK SURFACE TROF ACROSS THE OHIO VALLEY WITH HUMIDITY INCREASING AROUND THE BACKSIDE OF HIGH PRESSURE CENTERED OVER THE APPALACHIANS. NAM12 DEVELOPS SHOWERS AND THUNDERSTORMS AGAIN THIS AFTERNOON OVER SOUTHERN KENTUCKY AS LIFTED INDEX BOTTOMS OUT AROUND -3 WITH MID-LEVEL LAPSE RATES OF 6.5 DEG C/KM /THOUGH MORNING CIRRUS MAY PREVENT FULL DESTABILIZATION/. GFS...THOUGH OVERDONE IN AREAL COVERAGE AS IS TYPICAL OF THE MODEL...AGREES AND PRODUCES QPF ACROSS THE FORECAST AREA. SPC HAS GENERAL THUNDER AREA ACROSS OUR SOUTHERN TIER OF COUNTIES AND MOS POPS ARE GENERALLY IN THE 20S. NAM12 SHOWS A 850HPA THETA-E RIDGE OVER THE SOUTH THIS AFTERNOON. ATMOSPHERE NOT MUCH DIFFERENT TODAY THAN YESTERDAY...WHEN WIDELY SCATTERED THUNDERSTORMS DEVELOPED. SO...WILL INTRODUCE ISOLATED THUNDERSTORMS INTO THE FORECAST TODAY OVER THE SOUTH. STORMS YESTERDAY PRODUCED RAINFALL RATES UP TO AN INCH PER HOUR AND WE RECEIVED A FEW REPORTS OF WIND DAMAGE AND SMALL HAIL. LOOKING AT TODAY...PRECIPITABLE WATER VALUES ARE AROUND 1.5 INCHES AND WET BULB ZERO HEIGHT WILL BE AROUND 9500 FEET SO A LOCALLY HEAVY DOWNPOUR AND A LITTLE SMALL HAIL WILL BE POSSIBLE IN THE STRONGEST CONVECTION. STORM MOTION IS EXPECTED TO BE ONLY AROUND 10MPH...ADDING TO THE POSSIBILITY OF LOCALLY HEAVY RAIN. FORECAST SOUNDINGS SHOW A DECENT DRY LAYER AT 12000 TO 16000 FEET ABOVE A MOIST CLOUD-BEARING LAYER THIS AFTERNOON. THOUGH MDPI ONLY PEAKS AROUND 0.75 COULD STILL SEE SOME LOCALLY GUSTY WINDS IN THE STRONGEST STORMS THIS AFTERNOON AND EVENING. THE STORMS...IF ANY...SHOULD DISSIPATE OVERNIGHT. PATCHY FOG CAN BE EXPECTED THIS MORNING...PRIMARILY IN FOG PRONE AREAS. BOWLING GREEN AIRPORT...WHICH TYPICALLY FOGS IN VERY EASILY...SAW VISIBILITIES DROP TO A HALF MILE EARLIER THIS MORNING. THE PATCHY NATURE OF THE FOG IS EXPECTED TO PRECLUDE THE NECESSITY FOR ANY HEADLINES THIS MORNING...BUT WILL KEEP AN EYE ON IT. 13 .LONG TERM (SUNDAY THROUGH FRIDAY)... AN UPPER TROF WILL SLOWLY DEVELOP AND EDGE EASTWARD...STRETCHING FROM THE WESTERN GREAT LAKES TO OKLAHOMA BY 12Z TUESDAY. WEAK SURFACE WARM FRONT WILL BE DRAPED ACROSS THE CWFA SUNDAY AND SUNDAY NIGHT. PREVIOUS SHIFTS MENTIONED THE POSSIBILITY OF ISOLATED THUNDERSTORMS SUNDAY AFTERNOON. ATMOSPHERE SUNDAY AFTERNOON NOT TOO DIFFERENT THAN PREVIOUS TWO AFTERNOONS AND WITH POSSIBLE WEAK TRIGGERS ALOFT AND AT THE SURFACE LOOKS LIKE ISOLATED THUNDERSTORMS WILL BE A POSSIBILITY INDEED. MOS POPS ALSO AGREE WITH PUTTING IN A SMALL CHANCE OF RAIN FOR SUNDAY AFTERNOON/EVENING...AND THIS ALSO AGREES WITH SURROUNDING OFFICES. SPC HAS US IN A GENERAL THUNDER AREA IN THEIR DAY TWO OUTLOOK. A NORTH-SOUTH SURFACE TROF IS EXPECTED TO SWEEP IN FROM THE WEST MONDAY/MONDAY NIGHT WITH THE ASSOCIATED UPPER TROF SLIDING OVERHEAD TUESDAY AND WEDNESDAY ACCORDING TO GFS ENSEMBLE MEAN...OPERATIONAL GFS...AND CANADIAN /ITS WORTH NOTING THAT THE ECMWF DISAGREES WITH THIS SCENARIO/. SO...WILL GO WITH MAJORITY OPINION AND PREVIOUS FORECAST AND CONTINUE SHOWER/THUNDERSTORM CHANCE FOR TUESDAY AND WEDNESDAY...DRYING THINGS OUT FOR THURSDAY AND FRIDAY AS THE UPPER SYSTEM MOVES EAST. 13 && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 935 PM EDT SAT SEP 9 2006 .EVENING UPDATE 2... HAVE REMOVED REMAINDER OF POPS IN THE EVENING PERIOD WITH CONVECTION QUICKLY DECAYING DUE TO LOSS OF DIURNAL INSTABILITY. HAVE DROPPED TEMPS A FEW DEGS W OF BLUE RIDGE OVRNGT WHERE TEMPS ARE ALREADY DROPPING OFF FAIRLY QUICKLY. WILL HOLD CLOUD COVER AT MOSTLY CLEAR WITH SOME AREAS OF MID AND HIGH CLOUDS MOVING E FROM THE OH VLY. FOG WORDING ALSO LOOKS APPROPRIATE WITH AREAS OF FOG W OF THE BLUE RIDGE AND PATCHY FOG TO THE EAST. WEAK FRONT WILL DROP INTO THE REGION TNGT AND WILL STALL ON SUN. FRONT WILL MOVE N ON MON. 18Z MOS POPS INDICATE A SMALL CHC FOR SOME PRECIP SUN NGT INTO MON BUT NOT ENOUGH CONFIDENCE TO ADD AT THIS EARLY TIME. PLUS WITH SFC RIDGE BUILDING INTO THE MID ATLC FROM THE NORTH EXPECT ANY LIFTING MECH TO BE SQUASHED. JB && .PREVIOUS DISCUSSIONS... EVENING UPDATE... HAVE UPDATED TO ADD CHC POPS IN THE NW ONE-THIRD CWFA FOR THIS EVNG. ACTIVITY IS MAKING A BEE-LINE FOR NRN MD ATTM FROM CTRL PA...IN ADDITION SCATTERED SHOWERS ARE ALREADY BEGINNING TO DVLP OUT AHEAD OF THE MAIN ACTIVITY BATCH. LAPS DATA INDICATES SOME INSTABILITY TO TAP ACROSS NRN MD AND NE WV WHERE THE PA CONVECTION IS HEADED. GFS/NNM BOTH INDICATE CONVECTION SHOULD DISSIPATE AROUND MIDNIGHT SO POPS END AT 05Z. NO OTHER CHGS TO THE GOING FCST PACKAGE NECESSARY. SHORT TERM /TONIGHT THROUGH SUNDAY/... WATER VAPOR LOOP SHOWS A TROUGH BUILDING INTO THE NORTHERN GREAT LAKES...WITH A RIDGE ACROSS THE GULF OF MEXICO NORTHEAST OFF THE SOUTHEAST CONUS COAST. ACARS 400-250MB WIND OBSERVATIONS REVEAL A 60KT JET FROM THE MIDWEST SOUTHEAST INTO THE MID ATLANTIC. 11Z SURFACE ANALYSIS PLACED A 1021MB ANTICYCLONE ACROSS THE MID ATLANTIC. A STATIONARY FRONTAL BOUNDARY WAS LOCATED ALONG THE NORTHERN GULF OF MEXICO...THROUGH CENTRAL FLORIDA AND NORTHEAST OFF THE SOUTHEAST CONUS COAST. THE NEXT COLD FRONT HAS PUSHED THROUGH THE CENTRAL GREAT LAKES AND WAS APPROACHING THE EASTERN GREAT LAKES AND NEW ENGLAND. A 1027MB ANTICYCLONE DOMINATED SOUTH CENTRAL CANADA AND THE UPPER MIDWEST. A FEW SHOWERS HAVE DEVELOPED NEAR THE PENNSYLVANIA BORDER. EXPECTING THESE TO DECAY DURING THE LATE AFTERNOON AS 12Z NAM/GFS AND 15Z RUC INDICATE A MID LEVEL CAP WILL CONTINUE TO STRENGTHEN INTO THE EVENING. OTHERWISE SKIES WILL CLEAR AS CUMULUS DIMINISH DIURNALLY. ANTICIPATE AREAS OF FOG (LOCALLY DENSE IN THE CLIMATOLOGICALLY FAVORED VALLEYS) TO ONCE AGAIN DEVELOP OVERNIGHT. LOWS SHOULD BE NEAR READINGS THIS MORNING WITH WEAK ADVECTION AND SIMILAR MOISTURE CONTENT. COLD FRONT SAGS SOUTHWEST THROUGH THE FORECAST AREA TOMORROW. NOT EXPECTING PRECIPITATION TO DEVELOP AS THIS BOUNDARY BECOMES FURTHER REMOVED FROM THE MEAN FLOW ACROSS THE EASTERN GREAT LAKES. CUMULUS GROWTH WILL BE MOST EFFECTIVE ACROSS THE TERRAIN AND SOUTHERN FORECAST AREA AHEAD OF THE FRONTAL BOUNDARY. NORTHEASTERLY FLOW DEVELOPS BEHIND THE COLD FRONT. LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... FIRST PART OF WEEK SHOULD BE FAIRLY QUIET...WITH AN ACTIVE WEATHER PATTERN RETURNING FOR MID WEEK...AND QUIET WEATHER IS EXPECTED FOR THE EARLY PART OF THE WEEKEND. UNFORTUNATELY...THERE ARE SOME DIFFERENCES IN THE MODEL SOLUTIONS FOR THE EXTENDED PORTION OF THE FORECAST. HAVE ONLY MADE SOME VERY SLIGHT CHANGES TO THE TUE-THU TIME PERIOD...AS CONFIDENCE IS LOW. WEAK SHORTWAVE RIDGING IS IN PLACE FOR THE BEGINNING OF THE WEEK...HOWEVER THE FLOW IS EXPECTED TO TURN MORE SOUTHWEST AS A TROUGH AND ASSOCIATED SHORTWAVE MOVE EAST OVER THE PLAINS. THE MODELS ARE FURTHER NORTH THAN YESTERDAYS SOLUTIONS WITH THIS FEATURE. IN ADDITION...THERE ARE STRENGTH AND TIMING DIFFERENCES BETWEEN THE INDIVIDUAL MODELS TODAY. THERE ARE ALSO DIFFERENCES AT THE SURFACE. SINCE THE GFS IS STRONGER AND SOMEWHAT FASTER THAN THE NAM...THE SURFACE LOWS AND ASSOCIATED BOUNDARIES ARE ALSO STRONG AND FASTER. HAVE TAKEN SOMEWHAT OF A COMPROMISE BETWEEN THE TWO UNTIL THE MODELS COME INTO BETTER AGREEMENT. AVIATION... A REMOTE SHOWER OR TWO ACROSS NORTHERN MARYLAND DURING THE AFTERNOON...WITH CU DIMINISH DIURNALLY. EXPECTING AREAS OF DENSE FOG TO DEVELOP ONCE AGAIN OVERNIGHT GIVEN GOOD RADIATIONAL COOLING CONDITIONS. MARINE... MESOSCALE PROCESSES WILL DOMINATE INTO THIS EVENING...YIELDING VARIABLE WINDS LESS THAN 10KT WITH THE SURFACE RIDGE ACROSS THE REGION. EXPECTING WINDS TO BECOME SOUTHERLY OVERNIGHT EXHIBITING CHANNELING CHARACTERISTICS AHEAD OF A COLD FRONT (ALTHOUGH 12Z NAM/GFS BUFKIT FORECAST SOUNDINGS DO NOT INDICATE GUSTS GREATER THAN 12KTS). WATER LEVELS ARE ABOUT A HALF FOOT ABOVE PREDICTED VALUES. THE LUNAR CYCLE IS AT FULL MOON. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ md AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 737 PM EDT SAT SEP 9 2006 .EVENING UPDATE... HAVE UPDATED TO ADD CHC POPS IN THE NW ONE-THIRD CWFA FOR THIS EVNG. ACTIVITY IS MAKING A BEE-LINE FOR NRN MD ATTM FROM CTRL PA...IN ADDITION SCATTERED SHOWERS ARE ALREADY BEGINNING TO DVLP OUT AHEAD OF THE MAIN ACTIVITY BATCH. LAPS DATA INDICATES SOME INSTABILITY TO TAP ACROSS NRN MD AND NE WV WHERE THE PA CONVECTION IS HEADED. GFS/NNM BOTH INDICATE CONVECTION SHOULD DISSIPATE AROUND MIDNIGHT SO POPS END AT 05Z. NO OTHER CHGS TO THE GOING FCST PACKAGE NECESSARY. JB && .PREVIOUS DISCUSSIONS... SHORT TERM /TONIGHT THROUGH SUNDAY/... WATER VAPOR LOOP SHOWS A TROUGH BUILDING INTO THE NORTHERN GREAT LAKES...WITH A RIDGE ACROSS THE GULF OF MEXICO NORTHEAST OFF THE SOUTHEAST CONUS COAST. ACARS 400-250MB WIND OBSERVATIONS REVEAL A 60KT JET FROM THE MIDWEST SOUTHEAST INTO THE MID ATLANTIC. 11Z SURFACE ANALYSIS PLACED A 1021MB ANTICYCLONE ACROSS THE MID ATLANTIC. A STATIONARY FRONTAL BOUNDARY WAS LOCATED ALONG THE NORTHERN GULF OF MEXICO...THROUGH CENTRAL FLORIDA AND NORTHEAST OFF THE SOUTHEAST CONUS COAST. THE NEXT COLD FRONT HAS PUSHED THROUGH THE CENTRAL GREAT LAKES AND WAS APPROACHING THE EASTERN GREAT LAKES AND NEW ENGLAND. A 1027MB ANTICYCLONE DOMINATED SOUTH CENTRAL CANADA AND THE UPPER MIDWEST. A FEW SHOWERS HAVE DEVELOPED NEAR THE PENNSYLVANIA BORDER. EXPECTING THESE TO DECAY DURING THE LATE AFTERNOON AS 12Z NAM/GFS AND 15Z RUC INDICATE A MID LEVEL CAP WILL CONTINUE TO STRENGTHEN INTO THE EVENING. OTHERWISE SKIES WILL CLEAR AS CUMULUS DIMINISH DIURNALLY. ANTICIPATE AREAS OF FOG (LOCALLY DENSE IN THE CLIMATOLOGICALLY FAVORED VALLEYS) TO ONCE AGAIN DEVELOP OVERNIGHT. LOWS SHOULD BE NEAR READINGS THIS MORNING WITH WEAK ADVECTION AND SIMILAR MOISTURE CONTENT. COLD FRONT SAGS SOUTHWEST THROUGH THE FORECAST AREA TOMORROW. NOT EXPECTING PRECIPITATION TO DEVELOP AS THIS BOUNDARY BECOMES FURTHER REMOVED FROM THE MEAN FLOW ACROSS THE EASTERN GREAT LAKES. CUMULUS GROWTH WILL BE MOST EFFECTIVE ACROSS THE TERRAIN AND SOUTHERN FORECAST AREA AHEAD OF THE FRONTAL BOUNDARY. NORTHEASTERLY FLOW DEVELOPS BEHIND THE COLD FRONT. LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... FIRST PART OF WEEK SHOULD BE FAIRLY QUIET...WITH AN ACTIVE WEATHER PATTERN RETURNING FOR MID WEEK...AND QUIET WEATHER IS EXPECTED FOR THE EARLY PART OF THE WEEKEND. UNFORTUNATELY...THERE ARE SOME DIFFERENCES IN THE MODEL SOLUTIONS FOR THE EXTENDED PORTION OF THE FORECAST. HAVE ONLY MADE SOME VERY SLIGHT CHANGES TO THE TUE-THU TIME PERIOD...AS CONFIDENCE IS LOW. WEAK SHORTWAVE RIDGING IS IN PLACE FOR THE BEGINNING OF THE WEEK...HOWEVER THE FLOW IS EXPECTED TO TURN MORE SOUTHWEST AS A TROUGH AND ASSOCIATED SHORTWAVE MOVE EAST OVER THE PLAINS. THE MODELS ARE FURTHER NORTH THAN YESTERDAYS SOLUTIONS WITH THIS FEATURE. IN ADDITION...THERE ARE STRENGTH AND TIMING DIFFERENCES BETWEEN THE INDIVIDUAL MODELS TODAY. THERE ARE ALSO DIFFERENCES AT THE SURFACE. SINCE THE GFS IS STRONGER AND SOMEWHAT FASTER THAN THE NAM...THE SURFACE LOWS AND ASSOCIATED BOUNDARIES ARE ALSO STRONG AND FASTER. HAVE TAKEN SOMEWHAT OF A COMPROMISE BETWEEN THE TWO UNTIL THE MODELS COME INTO BETTER AGREEMENT. AVIATION... A REMOTE SHOWER OR TWO ACROSS NORTHERN MARYLAND DURING THE AFTERNOON...WITH CU DIMINISH DIURNALLY. EXPECTING AREAS OF DENSE FOG TO DEVELOP ONCE AGAIN OVERNIGHT GIVEN GOOD RADIATIONAL COOLING CONDITIONS. MARINE... MESOSCALE PROCESSES WILL DOMINATE INTO THIS EVENING...YIELDING VARIABLE WINDS LESS THAN 10KT WITH THE SURFACE RIDGE ACROSS THE REGION. EXPECTING WINDS TO BECOME SOUTHERLY OVERNIGHT EXHIBITING CHANNELING CHARACTERISTICS AHEAD OF A COLD FRONT (ALTHOUGH 12Z NAM/GFS BUFKIT FORECAST SOUNDINGS DO NOT INDICATE GUSTS GREATER THAN 12KTS). WATER LEVELS ARE ABOUT A HALF FOOT ABOVE PREDICTED VALUES. THE LUNAR CYCLE IS AT FULL MOON. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ md AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 251 PM EDT SAT SEP 9 2006 .SHORT TERM /TONIGHT THROUGH SUNDAY/... WATER VAPOR LOOP SHOWS A TROUGH BUILDING INTO THE NORTHERN GREAT LAKES...WITH A RIDGE ACROSS THE GULF OF MEXICO NORTHEAST OFF THE SOUTHEAST CONUS COAST. ACARS 400-250MB WIND OBSERVATIONS REVEAL A 60KT JET FROM THE MIDWEST SOUTHEAST INTO THE MID ATLANTIC. 11Z SURFACE ANALYSIS PLACED A 1021MB ANTICYCLONE ACROSS THE MID ATLANTIC. A STATIONARY FRONTAL BOUNDARY WAS LOCATED ALONG THE NORTHERN GULF OF MEXICO...THROUGH CENTRAL FLORIDA AND NORTHEAST OFF THE SOUTHEAST CONUS COAST. THE NEXT COLD FRONT HAS PUSHED THROUGH THE CENTRAL GREAT LAKES AND WAS APPROACHING THE EASTERN GREAT LAKES AND NEW ENGLAND. A 1027MB ANTICYCLONE DOMINATED SOUTH CENTRAL CANADA AND THE UPPER MIDWEST. A FEW SHOWERS HAVE DEVELOPED NEAR THE PENNSYLVANIA BORDER. EXPECTING THESE TO DECAY DURING THE LATE AFTERNOON AS 12Z NAM/GFS AND 15Z RUC INDICATE A MID LEVEL CAP WILL CONTINUE TO STRENGTHEN INTO THE EVENING. OTHERWISE SKIES WILL CLEAR AS CUMULUS DIMINISH DIURNALLY. ANTICIPATE AREAS OF FOG (LOCALLY DENSE IN THE CLIMATOLOGICALLY FAVORED VALLEYS) TO ONCE AGAIN DEVELOP OVERNIGHT. LOWS SHOULD BE NEAR READINGS THIS MORNING WITH WEAK ADVECTION AND SIMILAR MOISTURE CONTENT. COLD FRONT SAGS SOUTHWEST THROUGH THE FORECAST AREA TOMORROW. NOT EXPECTING PRECIPITATION TO DEVELOP AS THIS BOUNDARY BECOMES FURTHER REMOVED FROM THE MEAN FLOW ACROSS THE EASTERN GREAT LAKES. CUMULUS GROWTH WILL BE MOST EFFECTIVE ACROSS THE TERRAIN AND SOUTHERN FORECAST AREA AHEAD OF THE FRONTAL BOUNDARY. NORTHEASTERLY FLOW DEVELOPS BEHIND THE COLD FRONT. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... FIRST PART OF WEEK SHOULD BE FAIRLY QUIET...WITH AN ACTIVE WEATHER PATTERN RETURNING FOR MID WEEK...AND QUIET WEATHER IS EXPECTED FOR THE EARLY PART OF THE WEEKEND. UNFORTUNATELY...THERE ARE SOME DIFFERENCES IN THE MODEL SOLUTIONS FOR THE EXTENDED PORTION OF THE FORECAST. HAVE ONLY MADE SOME VERY SLIGHT CHANGES TO THE TUE-THU TIME PERIOD...AS CONFIDENCE IS LOW. WEAK SHORTWAVE RIDGING IS IN PLACE FOR THE BEGINNING OF THE WEEK...HOWEVER THE FLOW IS EXPECTED TO TURN MORE SOUTHWEST AS A TROUGH AND ASSOCIATED SHORTWAVE MOVE EAST OVER THE PLAINS. THE MODELS ARE FURTHER NORTH THAN YESTERDAYS SOLUTIONS WITH THIS FEATURE. IN ADDITION...THERE ARE STRENGTH AND TIMING DIFFERENCES BETWEEN THE INDIVIDUAL MODELS TODAY. THERE ARE ALSO DIFFERENCES AT THE SURFACE. SINCE THE GFS IS STRONGER AND SOMEWHAT FASTER THAN THE NAM...THE SURFACE LOWS AND ASSOCIATED BOUNDARIES ARE ALSO STRONG AND FASTER. HAVE TAKEN SOMEWHAT OF A COMPROMISE BETWEEN THE TWO UNTIL THE MODELS COME INTO BETTER AGREEMENT. && .AVIATION... A REMOTE SHOWER OR TWO ACROSS NORTHERN MARYLAND DURING THE AFTERNOON...WITH CU DIMINISH DIURNALLY. EXPECTING AREAS OF DENSE FOG TO DEVELOP ONCE AGAIN OVERNIGHT GIVEN GOOD RADIATIONAL COOLING CONDITIONS. && .MARINE... MESOSCALE PROCESSES WILL DOMINATE INTO THIS EVENING...YIELDING VARIABLE WINDS LESS THAN 10KT WITH THE SURFACE RIDGE ACROSS THE REGION. EXPECTING WINDS TO BECOME SOUTHERLY OVERNIGHT EXHIBITING CHANNELING CHARACTERISTICS AHEAD OF A COLD FRONT (ALTHOUGH 12Z NAM/GFS BUFKIT FORECAST SOUNDINGS DO NOT INDICATE GUSTS GREATER THAN 12KTS). WATER LEVELS ARE ABOUT A HALF FOOT ABOVE PREDICTED VALUES. THE LUNAR CYCLE IS AT FULL MOON. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ SHORT TERM...ROGOWSKI LONG TERM...PELOQUIN AVIATION... MARINE... md AREA FORECAST DISCUSSION..UPDATED NEAR TERM LONG TERM SLIGHTLY.. NATIONAL WEATHER SERVICE TAUNTON MA 647 PM EDT SAT SEP 9 2006 ...EVENING SMALL HAILERS/32 KT GUSTY WINDS ON THE WANE AND ARE PRECEDING A CHILLY CANADIAN HIGH TRANSITION AS WE AWAIT FLORENCES INTENSIFICATION AND POSSIBLE SUBSTANTIAL 10 TO 15 FOOT SURF-RIP CURRENT HAZARD FOR COASTAL WATERS... .NEAR TERM... AS OF 643 PM: WITHIN OUR CWA...MAX WIND REPORT THAT WE KNOW OF IS 32 KTS AT ORE. SMALL HAIL DID COVER THE GROUND IN EASTHAMPTON IN HAMPSHIRE COUNTY AT 507 PM. DID HAVE A REPORT AT 5PM OF PEA HAIL NORTHAMPTON. 535 PM PEA HAIL BELCHERTOWN AND SPRINGFIELD. ALSO HAD SMALL HAIL REPS AT FITCHBURG AND LUNENBURG. ALL THIS INFO FROM ASOS AND OR SKYWARN/SPOTTER CALLS. NOTHING IN WEBENTRY AS OF 640 PM. && .SHORT TERM /TONIGHT THROUGH SUNDAY/... CONVECTION THE MAIN CONCERN LATE THIS AFTERNOON INTO THE EVENING HOURS. BEST JET DYNAMICS EXPECTED TO EXTEND FROM WESTERN MA INTO SOUTHERN NH...AND NOT MUCH FURTHER EAST THAN I-495. THINKING CONVECTION WILL WEAKEN AS IT CONTINUES TO MARCH EAST. THIS IS SUPPORTED BY THE 09/18Z RUC AND THE 29/12Z GFS...RGEM AND NAM. THE DISSIPATION OF THE CUMULUS CLOUDS IN THE VISIBLE SATELLITE PICTURES ALSO NOT BODING WELL FOR STRONG CONVECTION ACROSS EASTERN MA AND MOST OF RI. THE LIMITING FACTOR IS THE RELATIVELY DRY AIR IN THE 900-750 MB LAYER. THAT SAID...THE 29/12Z GFS WAS THE MODEL OF CHOICE. THE NAM APPEARS TO BE OVERDOING ITS MOISTURE AND OMEGA FIELDS OVERNIGHT. AS A RESULT CONSIDERED THE NAM FOR TIMING THE FRONT ACROSS THE FORECAST AREA OVERNIGHT...BUT NOT MUCH MORE THAN THAT FOR THINGS LIKE SKY COVER. HIGH PRESSURE BUILDS SOUTH INTO THE REGION SUNDAY...AND SHOULD PROVIDE DRIER AND COOLER WEATHER. THE CANADIAN CLOUD PRODUCT HINTING AT SOME CLOUDS DEVELOPING IN THE NORTH FLOW SUNDAY...BUT MOST OF THOSE SHOULD BE IN THE MORNING. USED A BLEND OF THE VARIOUS MOS TEMPERATURE GUIDANCE WHICH WERE ALL VERY CLOSE. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... 12Z ECMWF/GFS OP RUNS ARE BLENDED WITH MID AFTERNOON TPC AND OPC EXPECTATIONS /RAISED 12Z GFS GWW GUIDANCE USING THE HURRICANE VERSION OF THE GWW GUIDANCE/. ALSO BLENDED WITH THIS MORNINGS 14Z HPC DAY 4-7 GUIDANCE AND A BIT OF 09Z SREF /SUSTAINED WIND 25KTS PROBABILITIES/ AND THE 12Z/9 GFS POP ENS FOR .10 IN 12 HRS. PLS REFERENCE TPC AND OPC EXPECTATIONS ON OPEN OCEAN IMPACTS OF FLORENCE. PRIMARY KBOX CWA EXPECTED HAZARD IS COMBINED HIGH SURF-RIP CURRENT- SPLASOVER ALONG THE MASSACHUSETTS OCEAN EXPOSED COAST AND POSSIBLY PARTS OF THE OCEAN EXPOSED RHODE ISLAND COASTS. HWO HAS BEEN UPDATED THIS AFTERNOON. THE SPS HAS JUST ISSUED AS WE NO LONGER EXPECT TO ISSUE CONVECTIVE SPS'S THIS EVENING. SURGE TODAY WAS RUNNING AROUND 0.3 FT AT BOS AND ACK. AM EXPECTING THIS TO BE LEAST A HALF A FOOT MONDAY AND TUESDAY ALONG THE MASS COAST. THAT PLUS LARGE SWELLS RAISES THE LIKELIHOOD OF AT LEAST MINOR SPLASHOVER ON THE OCEAN EXPOSED MASS COAST...ESPECIALLY THE AFTERNOON TIDES ON BOTH DAYS WHICH ARE ASTRONOMICALLY HALF A FOOT HIGHER THAN THE OVERNIGHT HIGH TIDE. AGAIN..WE NEED FLORENCE TO RAMP UP TO A HURRICANE BEFORE WE START WORDING THIS IN THE COASTAL ZONES. A SECONDARY HAZARD MAY BE FROST OR FREEZING TEMPERATURES FOR TUESDAY MORNING IN THE SOUTH CENTRAL NEW HAMPSHIRE AND FRANKLIN COUNTY /NW MASS/ VALLEYS. POPS ARE IN THE FCST FOR LATE WED NIGHT INTO EARLY FRI MORNING PER WET ADVECTION OF THE LIFTING WEAKENING OF THE NOTABLE MID WEEK MISS VALLEY 500 MB TROUGH THAT CROSSES NEW ENGLAND EARLY FRI. CHILLY AND LARGE LOW LVL LAPSE RATE NE FLOW IN THE LOWEST FEW THOUSAND FEET MAY GENERATE MORE OCEAN EFFECT CLOUDINESS THAN CURRENTLY FCST FOR MON/TUE IN EASTERN MASS. NEXT WEEKEND COULD TURN OUT QUITE NICE THO WE WILL HAVE LEFTOVER LOW LVL MOISTURE AND PROBABLY MORE MORNING FOG THAN CURRENTLY OUTLOOKED IN OUR FCST. HOWEVER...WARM 850 TEMPS AND WESTERLY FLOW SHOULD ALLOW FOR AT LEAST ONE VERY VERY NICE AFTERNOON BEFORE CANADIAN HIGH SPREADS TO OUR NORTH SUNDAY OR MORE LIKELY NEXT MONDAY. && .AVIATION... VFR CONDITIONS SHOULD BE THE RULE FOR MOST OF TONIGHT AND SUNDAY... THE EXCEPTION WILL BE LATE THIS AFTERNOON AND EVENING. SCATTERED SHOWERS AND THUNDERSTORMS WILL IMPACT AVIATION...ESPECIALLY TO THE NORTH AND WEST OF KASH-KORH-KBDL. MVFR VISIBILITY IN RAIN IS FORECAST. POCKETS OF HAIL WILL ALSO BE A CONCERN AS WELL AS GUSTY SURFACE WINDS IN THUNDERSTORMS. PLEASE SEE THE TAFS FOR MORE DETAILS. && .MARINE... IN THE SHORT TERM THROUGH SUNDAY...NOT MUCH GOING ON THIS EVENING. NORTH TO NORTHEAST PRESSURE GRADIENT SHOULD TIGHTEN A LITTLE DURING THE DAY...ESPECIALLY AS COOLER AIR STARTS TO ARRIVE DURING THE DAY. IN ADDITION SE SWELLS FROM DISTANT TROPICAL STORM FLORENCE SHOULD ALSO START TO ARRIVE. WILL CONTINUE THE MARINE WEATHER STATEMENT... AND FORGO THE ISSUANCE OF A SMALL CRAFT ADVISORY FOR NOW. LATER SHIFTS WILL LIKELY BE ISSUING ONE. LONG TERM...THE WH FCST WAS THE 12Z GFS WNA GUIDANCE WHICH WAS ONLY SLIGHTLY HIGHER THAN OUR PREV KBOX FCST MON-WED. THE HURRICANE VERSION OF THE 12Z GWW GUIDANCE FCSTS MAX COMBINED SEAS TO 19 FEET AT 44018 MIDDAY TUESDAY AND GLOUCESTER BOSTON TO 12 FEET BY TUE EVE. A MANUAL EDIT WAS APPLIED TO BOOST OUR CWF SEAS IN MAZ 250-254-255. NEXT FORECASTS PROBABLY NEED TO BRING THEM CLOSER TO THE SHORE IN THE E MASS WATERS IF FLORENCE CONTS ON TRACK BOTH LA/LO AND INTENSITY...SO THAT BOSTON HARBOR WILL READ THE SWELLS AT THE OUTER HARBOR ENTRANCE. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...NONE. && $$ SHORT TERM/AVIATION...BELK LONG TERM...DRAG ma AREA FORECAST DISCUSSION..UPDATED NEAR TERM.. NATIONAL WEATHER SERVICE TAUNTON MA 557 PM EDT SAT SEP 9 2006 ...EVENING SMALL HAILERS/35 KT GUSTY WINDS PRECEDE A CHILLY CANADIAN HIGH TRANSITION WHILE WE AWAIT FLORENCES INTENSIFICATION AND POSSIBLE SUBSTANTIAL 10 TO 15 FOOT SURF-RIP CURRENT HAZARD FOR COASTAL WATERS... .NEAR TERM... AS OF 557 PM: WITHIN OUR CWA...MAX WIND REPORT THAT WE KNOW OF IS 32 KTS AT ORE. SMALL HAIL DID COVER THE GROUND IN EASTHAMPTON IN HAMPSHIRE COUNTY AT 507 PM. DID HAVE A REPORT AT 5PM OF PEA HAIL NORTHAMPTON. 535 PM PEA HAIL BELCHERTOWN AND SPRINGFIELD. ALL THIS INFO FROM ASOS AND OR SKYWARN/SPOTTER CALLS. 554 PM 1/4 INCH HAIL AT FIT. NOTHING IN WEBENTRY AS OF 540 PM. && .SHORT TERM /TONIGHT THROUGH SUNDAY/... CONVECTION THE MAIN CONCERN LATE THIS AFTERNOON INTO THE EVENING HOURS. BEST JET DYNAMICS EXPECTED TO EXTEND FROM WESTERN MA INTO SOUTHERN NH...AND NOT MUCH FURTHER EAST THAN I-495. THINKING CONVECTION WILL WEAKEN AS IT CONTINUES TO MARCH EAST. THIS IS SUPPORTED BY THE 09/18Z RUC AND THE 29/12Z GFS...RGEM AND NAM. THE DISSIPATION OF THE CUMULUS CLOUDS IN THE VISIBLE SATELLITE PICTURES ALSO NOT BODING WELL FOR STRONG CONVECTION ACROSS EASTERN MA AND MOST OF RI. THE LIMITING FACTOR IS THE RELATIVELY DRY AIR IN THE 900-750 MB LAYER. THAT SAID...THE 29/12Z GFS WAS THE MODEL OF CHOICE. THE NAM APPEARS TO BE OVERDOING ITS MOISTURE AND OMEGA FIELDS OVERNIGHT. AS A RESULT CONSIDERED THE NAM FOR TIMING THE FRONT ACROSS THE FORECAST AREA OVERNIGHT...BUT NOT MUCH MORE THAN THAT FOR THINGS LIKE SKY COVER. HIGH PRESSURE BUILDS SOUTH INTO THE REGION SUNDAY...AND SHOULD PROVIDE DRIER AND COOLER WEATHER. THE CANADIAN CLOUD PRODUCT HINTING AT SOME CLOUDS DEVELOPING IN THE NORTH FLOW SUNDAY...BUT MOST OF THOSE SHOULD BE IN THE MORNING. USED A BLEND OF THE VARIOUS MOS TEMPERATURE GUIDANCE WHICH WERE ALL VERY CLOSE. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... 12Z ECMWF/GFS OP RUNS ARE BLENDED WITH MID AFTERNOON TPC AND OPC EXPECTATIONS /RAISED 12Z GFS GWW GUIDANCE USING THE HURRICANE VERSION OF THE GWW GUIDANCE/. ALSO BLENDED WITH THIS MORNINGS 14Z HPC DAY 4-7 GUIDANCE AND A BIT OF 09Z SREF /SUSTAINED WIND 25KTS PROBABILITIES/ AND THE 12Z/9 GFS POP ENS FOR .10 IN 12 HRS. PLS REFERENCE TPC AND OPC EXPECTATIONS ON OPEN OCEAN IMPACTS OF FLORENCE. PRIMARY KBOX CWA EXPECTED HAZARD IS COMBINED HIGH SURF-RIP CURRENT- SPLASOVER ALONG THE MASSACHUSETTS OCEAN EXPOSED COAST AND POSSIBLY PARTS OF THE OCEAN EXPOSED RHODE ISLAND COASTS. HWO HAS BEEN UPDATED THIS AFTERNOON. THE SPS ON THIS WILL REISSUE AS SOON AS THE SATURDAY AFTERNOON CONVECTION DIES. SURGE TODAY WAS RUNNING AROUND 0.3 FT AT BOS AND ACK. AM EXPECTING THIS TO BE LEAST A HALF A FOOT MONDAY AND TUESDAY ALONG THE MASS COAST. THAT PLUS LARGE SWELLS RAISES THE LIKELIHOOD OF AT LEAST MINOR SPLASHOVER ON THE OCEAN EXPOSED MASS COAST...ESPECIALLY THE AFTERNOON TIDES ON BOTH DAYS WHICH ARE ASTRONOMICALLY HALF A FOOT HIGHER THAN THE OVERNIGHT HIGH TIDE. AGAIN..WE NEED FLORENCE TO RAMP UP TO A HURRICANE BEFORE WE START WORDING THIS IN THE COASTAL ZONES. A SECONDARY HAZARD MAY BE FROST OR FREEZING TEMPERATURES FOR TUESDAY MORNING IN THE SOUTH CENTRAL NEW HAMPSHIRE AND FRANKLIN COUNTY /NW MASS/ VALLEYS. POPS ARE IN THE FCST FOR LATE WED NIGHT INTO EARLY FRI MORNING PER WET ADVECTION OF THE LIFTING WEAKENING OF THE NOTABLE MID WEEK MISS VALLEY 500 MB TROUGH THAT CROSSES NEW ENGLAND EARLY FRI. CHILLY AND LARGE LOW LVL LAPSE RATE NE FLOW IN THE LOWEST FEW THOUSAND FEET MAY GENERATE MORE OCEAN EFFECT CLOUDINESS THAN CURRENTLY FCST FOR MON/TUE IN EASTERN MASS. NEXT WEEKEND COULD TURN OUT QUITE NICE THO WE WILL HAVE LEFTOVER LOW LVL MOISTURE AND PROBABLY MORE MORNING FOG THAN CURRENTLY OUTLOOKED IN OUR FCST. HOWEVER...WARM 850 TEMPS AND WESTERLY FLOW SHOULD ALLOW FOR AT LEAST ONE VERY VERY NICE AFTERNOON BEFORE CANADIAN HIGH SPREADS TO OUR NORTH SUNDAY OR MORE LIKELY NEXT MONDAY. && .AVIATION... VFR CONDITIONS SHOULD BE THE RULE FOR MOST OF TONIGHT AND SUNDAY... THE EXCEPTION WILL BE LATE THIS AFTERNOON AND EVENING. SCATTERED SHOWERS AND THUNDERSTORMS WILL IMPACT AVIATION...ESPECIALLY TO THE NORTH AND WEST OF KASH-KORH-KBDL. MVFR VISIBILITY IN RAIN IS FORECAST. POCKETS OF HAIL WILL ALSO BE A CONCERN AS WELL AS GUSTY SURFACE WINDS IN THUNDERSTORMS. PLEASE SEE THE TAFS FOR MORE DETAILS. && .MARINE... IN THE SHORT TERM THROUGH SUNDAY...NOT MUCH GOING ON THIS EVENING. NORTH TO NORTHEAST PRESSURE GRADIENT SHOULD TIGHTEN A LITTLE DURING THE DAY...ESPECIALLY AS COOLER AIR STARTS TO ARRIVE DURING THE DAY. IN ADDITION SE SWELLS FROM DISTANT TROPICAL STORM FLORENCE SHOULD ALSO START TO ARRIVE. WILL CONTINUE THE MARINE WEATHER STATEMENT... AND FORGO THE ISSUANCE OF A SMALL CRAFT ADVISORY FOR NOW. LATER SHIFTS WILL LIKELY BE ISSUING ONE. LONG TERM...THE WH FCST WAS THE 12Z GFS WNA GUIDANCE WHICH WAS ONLY SLIGHTLY HIGHER THAN OUR PREV KBOX FCST MON-WED. THE HURRICANE VERSION OF THE 12Z GWW GUIDANCE FCSTS MAX COMBINED SEAS TO 19 FEET AT 44018 MIDDAY TUESDAY AND GLOUCESTER BOSTON TO 12 FEET BY TUE EVE. A MANUAL EDIT WAS APPLIED TO BOOST OUR CWF SEAS IN MAZ 250-254-255. NEXT FORECASTS PROBABLY NEED TO BRING THEM CLOSER TO THE SHORE IN THE E MASS WATERS IF FLORENCE CONTS ON TRACK BOTH LA/LO AND INTENSITY...SO THAT BOSTON HARBOR WILL READ THE SWELLS AT THE OUTER HARBOR ENTRANCE. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...NONE. && $$ SHORT TERM/AVIATION...BELK LONG TERM...DRAG ma AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 439 PM EDT SAT SEP 9 2006 .SHORT TERM /TONIGHT THROUGH SUNDAY/... CONVECTION THE MAIN CONCERN LATE THIS AFTERNOON INTO THE EVENING HOURS. BEST JET DYNAMICS EXPECTED TO EXTEND FROM WESTERN MA INTO SOUTHERN NH...AND NOT MUCH FURTHER EAST THAN I-495. THINKING CONVECTION WILL WEAKEN AS IT CONTINUES TO MARCH EAST. THIS IS SUPPORTED BY THE 09/18Z RUC AND THE 29/12Z GFS...RGEM AND NAM. THE DISSIPATION OF THE CUMULUS CLOUDS IN THE VISIBLE SATELLITE PICTURES ALSO NOT BODING WELL FOR STRONG CONVECTION ACROSS EASTERN MA AND MOST OF RI. THE LIMITING FACTOR IS THE RELATIVELY DRY AIR IN THE 900-750 MB LAYER. THAT SAID...THE 29/12Z GFS WAS THE MODEL OF CHOICE. THE NAM APPEARS TO BE OVERDOING ITS MOISTURE AND OMEGA FIELDS OVERNIGHT. AS A RESULT CONSIDERED THE NAM FOR TIMING THE FRONT ACROSS THE FORECAST AREA OVERNIGHT...BUT NOT MUCH MORE THAN THAT FOR THINGS LIKE SKY COVER. HIGH PRESSURE BUILDS SOUTH INTO THE REGION SUNDAY...AND SHOULD PROVIDE DRIER AND COOLER WEATHER. THE CANADIAN CLOUD PRODUCT HINTING AT SOME CLOUDS DEVELOPING IN THE NORTH FLOW SUNDAY...BUT MOST OF THOSE SHOULD BE IN THE MORNING. USED A BLEND OF THE VARIOUS MOS TEMPERATURE GUIDANCE WHICH WERE ALL VERY CLOSE. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... COMING SOON. && .AVIATION... VFR CONDITIONS SHOULD BE THE RULE FOR MOST OF TONIGHT AND SUNDAY... THE EXCEPTION WILL BE LATE THIS AFTERNOON AND EVENING. SCATTERED SHOWERS AND THUNDERSTORMS WILL IMPACT AVIATION...ESPECIALLY TO THE NORTH AND WEST OF KASH-KORH-KBDL. MVFR VISIBILITY IN RAIN IS FORECAST. POCKETS OF HAIL WILL ALSO BE A CONCERN AS WELL AS GUSTY SURFACE WINDS IN THUNDERSTORMS. PLEASE SEE THE TAFS FOR MORE DETAILS. && .MARINE... IN THE SHORT TERM THROUGH SUNDAY...NOT MUCH GOING ON THIS EVENING. NORTH TO NORTHEAST PRESSURE GRADIENT SHOULD TIGHTEN A LITTLE DURING THE DAY...ESPECIALLY AS COOLER AIR STARTS TO ARRIVE DURING THE DAY. IN ADDITION SE SWELLS FROM DISTANT TROPICAL STORM FLORENCE SHOULD ALSO START TO ARRIVE. WILL CONTINUE THE MARINE WEATHER STATEMENT... AND FORGO THE ISSUANCE OF A SMALL CRAFT ADVISORY FOR NOW. LATER SHIFTS WILL LIKELY BE ISSUING ONE. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...NONE. && $$ SHORT TERM/AVIATION...BELK LONG TERM...DRAG ma AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 1140 PM EDT SAT SEP 9 2006 .UPDATED... I UPDATED THE ZONES FOR MORE CLOUDS TONIGHT AND SUNDAY. I ALSO ADDED SHOWERS TO SOUTHWEST LOWER SECTION OF THE ZONES THIS AFTERNOON. LOW TEMPERATURES TONIGHT WERE INCREASED 5 TO 8F OVER THE SOUTHERN AND CENTRAL CWA DUE TO THE CLOUDS HOLDING IN PLUS I DECREASED THE FORECAST HIGH SUNDAY FOR THE SAME REASON. ALL OF THIS IS BASED ON THE NEAR STATIONARY 850 MB FRONT NEAR INTERSTATE 96 TONIGHT THROUGH SUNDAY. THERE IS THE ADDED BONUS OF MID AND HIGH LEVEL MOISTURE BEING ADVECTED IN FROM THE DOWNSTREAM LOW AND MID LEVEL INFLOW RUNNING INTO THE SURFACE FRONTAL BOUNDARY AND BEING LIFTED OVER IT THEN ADVECTED EASTWARD DOWNSTREAM TOWARD SOUTHWEST LOWER MICHIGAN. IT IS MY CONTENTION THE LOW CLOUDS WILL HOLD SOLIDLY OVER THE SOUTHWEST CWA THROUGH SUNDAY NIGHT. THE WATER VAPOR LOOPS SHOW WHAT THE 00Z NAM AND RUC SUGGEST... WHICH IS THAT DOWN STREAM LOW AND MID LEVEL MOISTURE INFLOW IS NOW MOVING INTO SOUTHWEST LOWER MICHIGAN AND WITH THE AID OF JET INFLOW REGION LIFT WILL RESULT IN THE CHANCE OF SHOWERS SUNDAY DURING THE DAY FROM GRR WEST TO THE LAKE SHORE. WHILE THE ISENTROPIC LIFT IS NOT ALL THAT GREAT THERE IS DECENT FGEN FORCING NEAR 850 MB THROUGH MOST OF THE DAY SUNDAY FROM RQB SOUTH TO SBN. THAT COUPLED WITH THE INCREASE IN MID LEVEL MOISTURE AND THE INCREASE TO TOTAL COLUMN MOISTURE...THAT IS PWAT VALUES RISE FROM NEAR 1 INCH AT 00Z OVER GRR TO NEAR 1.3 INCHES BY LATE AFTERNOON... I BELIEVE THERE IS AT LEAST A CHANCE OF SOME LIGHT RAIN SHOWERS OVER THE SOUTHWEST SECTIONS OF LOWER MICHIGAN AND LITTLE CHANCE OF MUCH CLEARING. && .GRR WATCHES/WARNINGS/ADVISORIES...NONE. && $$ WDM mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 509 PM EDT SAT SEP 9 2006 .DISCUSSION... NEAR TERM CONCERN IS ON COLD TEMPS AND FROST/FREEZE HEADLINES TONIGHT...THEN FOCUS SHIFTS TO POTENTIAL FOR RAIN LATE MON THROUGH TUE. WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A RIDGE AMPLIFYING OVER THE NRN ROCKIES AND A DOWNSTREAM TROF OVER SE CANADA. RIDGE IS SUPPORTING SFC HIGH PRES OVER SCNTRL CANADA AND THE UPR GREAT LAKES. DESPITE 850MB TEMPS OF 0C OR LESS AT CWPL/KINL SNDGS...LAKE EFFECT CLOUD COVERAGE IS IF ANYTHING DIMINISHING AND VERY LIMITED CU HAS FORMED OVER INLAND AREAS. THE REASON FOR LACK OF CLOUDS IS VERY AIR UNDERNEATH 800-850 MB INVERSION AS NOTED ON 12Z CWPL AND KINL SNDGS. LACK OF CLOUDS AND RIDGING OVER FCST AREA WILL SET THE STAGE FOR A CHILLY NIGHT AND LIKELY FREEZING OR NEAR FREEZING TEMPS OVER MANY INLAND LOCATIONS TONIGHT. GOING HEADLINES WITH FREEZE WARNING OVER INLAND WESTERN COUNTIES AND FROST ADVISORIES FOR KEWEENAW PENINSULA AND SCNTRL/ERN COUNTIES STILL ON TRACK...SO DID NOT HAVE TO MAKE ANY SIGNIFICANT CHANGES TO TONIGHTS FCST. OTHER SYSTEM OF CONCERN IS WELL-DEFINED SHORTWAVE AND DEVELOPING LOW PRESSURE OVER THE CENTRAL PLAINS AS NOTED ON WATER VAPOR LOOP. MODELS VARY WIDELY ON HANDLING OF THIS SHORTWAVE IN NEXT 48-72 HRS. THE NAM AND CANADIAN ARE MUCH LESS AMPLIFIED WITH THIS WAVE AND KEEP AFFECTS OF RESULTING SFC SYSTEM WELL SOUTH AND EAST OF OUR FCST AREA. THE UKMET ON THE OTHER HAND HAS TRENDED TOWARD THE GFS WHICH SHOWS AN UPPER LOW FORMING OVER SRN MN IN MON TO TUE TIME FRAME. THESE MODELS APPEAR TO BE FORMING TROUGH/CLOSED LOW IN RESPONSE TO TROPICAL STORM FLORENCE MOVING UP THE ATLANTIC COAST AND CAUSING A BLOCK IN MID-UPR FLOW PATTERN. BELIEVE GFS/UKMET MAY BE ON TO SOMETHING AND CANNOT SIMPLY DISCOUNT THEIR SOLUTIONS...ALTHOUGH IT IS CERTAINLY POSSIBLE THEY MAY BE TOO AGGRESSIVE BRINGING SYSTEM SO FAR NORTH GIVEN STRENGTH OF CANADIAN RIDGE AND DRY AIR THAT WILL BE IN PLACE. EVEN SO...THE FACT THAT UKMET HAS TRENDED MORE TOWARD GFS... FEEL COMPELLED TO INCLUDE MENTION OF CHC POPS OF SHRA LATE MON FOR SCNTRL COUNTIES AND THEN SPREAD CHC OF SHRA NORTH ACROSS CENTRAL AND ERN ZONES MON NIGHT INTO TUE NIGHT. EVEN THREW IN A SLIGHT CHC FOR WRN COUNTIES IN CASE MORE WRN TRACK OF LOW VERIFIES PER GFS/UKMET SOLNS. EXTENDED (WED-SAT)...STILL BANK ON REMNANTS OF LOW PRESSURE TO WEAKEN OVER THE CENTRAL LAKES SO KEPT WED DRY BUT INCLUDED A BIT MORE CLOUD COVER AND TRIMMED HIGH TEMPS A FEW DEGREES AS WELL. 00Z MODELS INDICATED RIDGING SHOULD HOLD IN PLACE THROUGH THU NIGHT BUT THEN THAT WAS SUPPORT BY MODELS AND GFS ENSEMBLE MEAN FOR WEAK BOUNDARY TO SAG SLOWLY SE ACROSS THE AREA AS MID-LVL FLOW BECOMES MORE SW AHEAD OF DEVELOPING WRN CONUS RIDGE. DID INCLUDE CHC OF PCPN FRI INTO SAT. && .MQT WATCHES/WARNINGS/ADVISORIES... FREEZE WARNING TONIGHT MIZ002-004-005-009>011-084. FROST ADVY TONIGHT MIZ001-003-006-007-012>014-085. && $$ VOSS mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1111 AM EDT SAT SEP 9 2006 .UPDATE...12Z SURFACE/RUC ANALYSIS AND VIS/IR/WV/RADAR IMAGERY SHOW HIGH PRESSURE JUST NORTH OF LAKE SUPERIOR EMBEDDED UNDER NORTHWEST FLOW ALOFT. LAST NIGHTS SURFACE COLD FRONT HAS PUSHED SOUTH OVER IA/IL/SOUTHERN MI/AND THE EASTERN GREAT LAKES...WHILE THE 850MB FRONT CONTINUES TO HANG ACROSS CENTRAL MI. MOST OF THE DEEPER CLOUD COVER REMAINS ALONG THIS FRONT JUST SOUTH OF A KMBL TO KOSC LINE. 500MB SHORTWAVE CONTINUES TO DIVE SOUTHWARD WITH THE LEADING EDGE SOUTH OF THE STRAITS. MUCH DRIER AIR RESIDES TO THE NORTH AS EVIDENT BY THE MOSTLY CLEAR/PARTLY CLOUDY SKIES. 12Z APX SOUNDING SHOWS LOW LEVEL NE FLOW AND A STRONG INVERSION IN PLACE AT 850MB. WITH TEMPS AT THIS LEVEL AT 3C AND 19-20C LAKE TEMPS...STRONG LOW LEVEL LAPSE RATES ARE PROMOTING LAKE EFFECT STRATOCU BANDS ACROSS MOST OF NORTHERN LOWER...WHILE DOWNSLOPING OFF OF THE ONTARIO PLATEAU HAS KEPT EASTERN UPPER MOSTLY CLEAR. A FEW SHRA SHOWING UP ON THE OBS ACROSS THE SE CWA WHERE THE LARGEST Q-VECTOR CONVERGENCE IS IN PLACE. MAIN FORECAST CONCERNS FOR THIS AFTERNOON CONTINUES TO BE THE CHANCE OF DRIZZLE AND/OR LIGHT SHOWERS. BASED MOSTLY ON THE 12Z APX SOUNDING...GFS LOOKS LIKE THE MOST REPRESENTATIVE OF THE MODELS...AND HAVE FOLLOWED ITS GUIDANCE MORE CLOSELY. THE 500MB SHORTWAVE IS PROGGED TO EXIT THE CWA THIS AFTERNOON. EVEN THOUGH PLENTY OF INSTABILITY WILL REMAIN OVER THE LAKE WITH 850 TEMPS HOLDING STEADY AT 3-5C...BELIEVE INCREASING SUBSIDENCE AND DECREASING UPPER LEVEL SUPPORT WILL PREVENT ANY SHOWER DEVELOPMENT MID TO LATE AFTERNOON. THEREFORE...WILL KEEP THE FORECAST INTACT...WITH A CHANCE OF SHOWERS ENDING AT 18Z. SURFACE HIGH PRESSURE WILL SLOWLY SLIDE TO THE SE TODAY AS THE 850MB FRONT MOVES TO THE SOUTH. THEREFORE...ANTICYCLONIC LOW LEVEL FLOW WILL INCREASE DURING THE AFTERNOON AND A CLEARING TREND WILL TAKE PLACE FROM NW TO SE AS DRIER AIR MIXES OUT THE LOW LEVEL MOISTURE. HOW MUCH CLEARING IS HARD TO SAY. BELIEVE WITH THE FRESH SUPPLY OF LOW LEVEL MOISTURE FROM LAKE HURON AND UPSLOPE FLOW COMBINED WITH THE SYNOPTIC MOISTURE FROM THE UPPER LEVEL WAVE WILL KEEP SKIES MOSTLY CLOUDY THIS AFTERNOON FROM PRESQUE ISLE TO MANISTEE WHILE SKIES WILL BECOME PARTLY CLOUDY NORTH OF THAT LINE. EASTERN UPPER LOOKS TO REMAIN MOSTLY SUNNY WITH DOWNSLOPING. MARINE...HAVE KEPT SMALL CRAFT ADVISORIES IN THE FORECAST THROUGH THE REMAINDER OF THE AFTERNOON. NORTHERN LAKE MI AND LAKE HURON BUOYS SHOWED WAVES GREATER THAN 4FT. OVER WATER INSTABILITY WITH WINDS GUSTING TO 20KTS WILL KEEP WAVES IN THE 3 TO 5 FOOT RANGE WITH LOCALLY HIGHER WAVES WITHIN THE LAKE HURON NEARSHORE AREA. MPC PREVIOUS DISCUSSION...ISSUED AT 335 AM EDT SAT SEP 9 2006 07Z SURFACE/SATELLITE/RUC/AND REGIONAL RADAR ANALYSIS HAS COLD FRONT THAT CROSSED NORTHERN MICHIGAN FRIDAY AFTERNOON NOW STRETCHING FROM PORT HURON TO JUST NORTH OF CHICAGO. COLD FRONT CONTINUES TO EDGE SOUTH AS 1024 MB WESTERN ONTARIO HIGH PRESSURE BUILDS INTO THE NORTHERN LAKES. LARGE AREA OF SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS PROPAGATING EAST BASICALLY ALONG AND SOUTH OF M-72. THESE SHOWERS ARE FIRING IN ZONE OF MASS CONVERGENCE ALONG AND JUST NORTH OF 850MB COLD FRONT. ADDITIONAL MID AND UPPER LEVEL SUPPORT PROVIDED BY SHORTWAVE CROSSING LAKE SUPERIOR AND FAVORABLE UPPER LEVEL DIVERGENCE FIELD IN RIGHT ENTRANCE REGION OF 80 KNOT 300MB JET THAT STRETCHES FROM EASTERN ONTARIO INTO QUEBEC. AS FOR TEMPERATURES...A TRUE TASTE OF FALL DEFINITELY IN THE AIR WITH SEVERAL STATIONS DROPPING INTO THE MID 40S TO LOWER 50S DESPITE THE ABUNDANCE OF CLOUDS ACROSS THE REGION. FARTHER NORTH...READINGS WELL INTO THE LOW TO MID 30S JUST NORTH OF LAKE SUPERIOR. FORECAST CONCERNS CENTERED AROUND PRECIPITATION CHANCES IN SOUTHERN ZONES THIS MORNING...LAKE EFFECT POTENTIAL AS OVER WATER INSTABILITY INCREASES...FROST POTENTIAL TONIGHT AND SUNDAY NIGHT...AND ONGOING MARINE HEADLINES. TODAY...SOUTHERN MICHIGAN COLD FRONT WILL BE FORCED SOUTH AS AFOREMENTIONED ONTARIO HIGH PRESSURE CONTINUES TO BUILD INTO THE REGION. BIG CONCERN EARLY ON IS WHAT TO DO WITH LINGERING SHOWERS THIS MORNING IN SOUTHERN ZONES. PRECIPITATION WILL GRADUALLY DECREASE THIS MORNING AS 850MB FRONT PUSHES SOUTH AND MID LEVEL DYNAMICS ADVANCE EAST WITH SHORTWAVE. WILL HAVE SCATTERED WORDING FOR SOUTHERN TIER OF COUNTIES THROUGH THIS MORNING TO ACCOUNT FOR ANY LINGERING ACTIVITY. ELSEWHERE...LARGE SCALE SUBSIDENCE AND DRYING IN THE MID AND UPPER LEVELS WILL OVERSPREAD THE AREA. NAM-WRF POINT MODEL SOUNDINGS SUPPORT FAVORABLE CONDITIONS FOR DRIZZLE FORMATION THIS MORNING FOR THE MUCH OF THE REMAINING AREAS OF THE NORTHERN LOWER AS STRENGTHENING SUBSIDENCE INVERSION CAPS SATURATED SURFACE TO 900MB LAYER. SAME PROFILE ALSO SUPPORTS CLOUDY CONDITIONS FOR THE MORNING HOURS AS SUFFICIENT MIXING WILL NOT OCCUR TO SCOUR OUT THE CLOUDS. ONE EXCEPTION IS THE EXTREME EASTERN UPPER AS DOWNSLOPING NORTHEAST FLOW OUT OF ONTARIO HAS ERODED THE LOW OVERCAST. BY THIS AFTERNOON...BOUNDARY LAYER DRYING OVER THE TIP OF THE MITT AND REMAINING AREAS OF THE EASTER UPPER WILL HELP BREAK UP THE OVERCAST. CENTRAL AND SOUTHERN ZONES WILL REMAIN CLOUDY AS LOW LEVEL DRYING WILL BE A SLOW TO WORK SOUTH. ADDITIONAL LOW LEVEL MOISTURE WILL BE PROVIDED FROM NORTHEAST WINDS OFF OF LAKE HURON AS STRONG COLD AIR ADVECTION LOWERS 900 MB TEMPERATURES TO AROUND +3C BY 21Z. WITH WATER TEMPERATURES STILL UP AROUND 19C THIS GENERATES LAKE-900 MB DELTA T/S OF 16C. NOT CONCERNED WITH LAKE EFFECT RAIN SHOWERS AS STRONG INVERSION WILL PREVENT SIGNIFICANT CONVECTIVE GROWTH. TEMPERATURES TODAY WILL BE STUCK GENERALLY IN THE 50S WITH CONTINUED CAA AND LACK OF SOLAR INSOLATION. TONIGHT...BOUNDARY LAYER DRYING CONTINUES ACROSS THE AREA OVERNIGHT. EXPECT SKIES TO BECOMING PARTLY CLOUDY AWAY FROM NORTHEAST WIND LAKE EFFECT REGIONS WHERE NORTHEAST FLOW COUPLED WITH DELTA T/S REMAINING IN THE MID TO UPPER TEENS SHOULD KEEP LAKE CLOUDS SPREADING ONSHORE. LAKE INDUCED BOUNDARY LAYER DOES INCREASE TONIGHT TO AROUND 850 MB BUT STILL NOT SUFFICIENT FOR SHOWER GENERATION. TEMPERATURES A BIGGER CONCERN WITH READINGS EXPECTED TO DROP INTO THE MID 30S IN THE TYPICAL COOLER INTERIOR REGIONS TO AROUND 40 NEAR THE LAKES. LIKE PREVIOUS FORECASTER MENTIONED...DO NOT THINK FROST WILL BECOME WIDESPREAD AS WINDS DO NOT TOTALLY DECOUPLE AND SOME LAKE CLOUDS LINGER OVER THE AREA. WILL THEREFORE KEEP PATCHY FROST WORDING IN GRIDS. SUNDAY AND SUNDAY NIGHT...DRY AND COOL WEATHER ACROSS THE AREA AS HIGH PRESSURE REMAINS IN CONTROL. WILL KEEP THE SCT-BKN CLOUD COVER OVER ALONG AND EAST OF I-75 WITH LAKE CLOUDS STREAMING IN OFF LAKE HURON IN LIGHT EASTERLY FLOW. A LITTLE MORE SUNSHINE SHOULD HELP TEMPERATURE WARM BY A DEGREE OR TWO ON SUNDAY. PATCHY FROST IS ONCE AGAIN EXPECTED SUNDAY NIGHT WITH READINGS IN THE MID 30S TO AROUND 40. SOME CONCERN FOR A MORE WIDESPREAD FROST AS WINDS MAY DECOUPLE AND GO CALM AND LESS LAKE CLOUDS. WILL CONTINUE TO MONITOR. REST OF FORECAST UNCHANGED. MARINE...WILL KEEP SCA ADVISORY FOR NORTHERN LOWER MICHIGAN NEARSHORE WATERS OF LAKE MICHIGAN AND HURON THROUGH 22Z. IMPRESSIVE OVER WATER INSTABILITY ALONG WITH A DECENT PRESSURE GRADIENT SHOULD CONTINUE TO RESULT IN SOME HIGHER WIND GUST AND WAVE GENERATION. HIGH PRESSURE BUILDING IN LATER THIS AFTERNOON AND TONIGHT WILL HELP DIMINISH THE WIND AS GRADIENT RELAXES. MSB && .APX...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DULUTH MN ISSUED BY NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 358 PM CDT SAT SEP 9 2006 .DISCUSSION... MAIN FCST CHALLENGE IS FROST THREAT TONIGHT. GOES WV LOOP SHOES FA UNDER CONFLUENT FLOW BETWEEN ONE SHORT WAVE TO THE NORTH ON WESTERN EDGE OF ERN CANADA LONG WAVE...AND STRONGER NEGATIVELY TILTED WAVE IN WRN NEB. AT THE SFC...LATEST ANALYSIS PLACED RIDGE FROM 1028MB CANADIAN HIGH CENTERED JUST NORTH OF LK SUPERIOR. ERLY FLOW BENEATH THIS HAS BEGAN TO SLACKEN AND LK GENERATED STRATOCU HAS FALLEN APART. THE RUC CONTINUES 7-8C LAPSE RATES AND HIGH MOISTURE IN THE 1000-850MB LAYER INTO THE EVENING FOR THE ERN ARROWHEAD...WHICH MAY BE A HINDRANCE TO FROST DEVELOPMENT IN THAT AREA. HOWEVER...REST OF FA IS PRIMED AND FROST ADVISORY IS IN EFFECT FOR ENTIRE AREA...EXCEPT COASTAL LOCALES. NW WI SHOULD SEE COOLER VALUES THAN LAST NIGHT GIVEN CURRENT RIDGE PLACEMENT AND WINDS VEERING MORE ERLY OFFERING NO WARMING FROM THE LAKE. THE CANADIAN RIDGE WILL PERSIST THRU THE WEEKEND AND INTO MON. ON SHORE FLOW MAY GENERATE SOME STRATOCU AGAIN OVER THE ERN ARROWHEAD TOMORROW...BUT THATS ABOUT IT. H8 TEMPS SIMILAR BUT SOUTHERLY COMPONENT TO THE WINDS SHOULD OFFER A DEGREE OR TWO WARMER SFC TEMPS. THE 12Z RUNS OF THE NAM_WRF AND GFS DIFFER GREATLY FROM THE GET GO WITH HANDLING OF WRN NEB TROUGH AS IT PULLS E. HAVE LEANED MORE TOWARDS THE NAM_WRF...AS THE GIVEN UPPER LEVEL FLOW WOULD FAVOR A MORE EWRD TRACK OF THE SYSTEM. THIS SOLUTION OFFER THIS AND KEEPS PRECIP FOCUSED ALONG THE WARM FRONT ...WHICH WOULD BE NAMELY OVER SE MN AND SRN WI. DO HAVE A SLIGHT CHC IN FAR SE CWA FOR MON AFTN AND NIGHT AS COMPROMISE BETWEEN NAM_WRF AND GFS THETA FIELDS DO BRING SOME WRAPAROUND UPGLIDE INTO THIS AREA. BUT THAT IS THE EXTENT OF THE IMPACT FROM THAT SYSTEM. SLOW H8 WARMING THRU THE MIDDLE OF THE WEEK WITH LO LVL SOUTHERLY FLOW...SO HAVE TEMPS MODERATING SLIGHTLY. NO SIG CHANGES MADE TO FCST PAST THURS. && .POINT FORECAST TEMPS/POPS... DLH 37 61 41 64 / 0 0 0 10 INL 32 65 37 65 / 0 0 0 0 BRD 35 64 39 69 / 0 0 0 0 HYR 32 64 40 68 / 10 0 10 10 ASX 33 61 41 65 / 0 0 10 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...FROST ADVISORY FROM 1 AM TO 7 AM CDT SUNDAY FOR CARLTON/SOUTHERN ST. LOUIS-CENTRAL ST. LOUIS-CROW WING-KOOCHICHING-NORTHERN AITKIN-NORTHERN CASS-NORTHERN COOK/NORTHERN LAKE-NORTHERN ITASCA-NORTHERN ST. LOUIS-PINE-SOUTHERN AITKIN-SOUTHERN CASS-SOUTHERN ITASCA. WI...FROST ADVISORY FROM 1 AM TO 7 AM CDT SUNDAY FOR ASHLAND-BAYFIELD- BURNETT-DOUGLAS-IRON-PRICE-SAWYER-WASHBURN. LS...SMALL CRAFT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR LSZ142- LSZ143-LSZ144-LSZ145-LSZ146-LSZ147. $$ MTF mn AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE DULUTH MN ISSUED BY NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 1221 PM CDT SAT SEP 9 2006 .UPDATE... FCST ZONES AND GRIDS UPDATED MAINLY TO REFLECT ENHANCED FROST THREAT TONIGHT OVER MOST OF THE FA. KINL 12Z RAOB AND RUC DATA INDICATING FAVORABLE H8-H9 LAPSE RATES FOR CONTINUED STRATOCU DEVELOPMENT OFF THE WARM WATERS OF LK SUPERIOR INTO THIS AFTN. HAVE EXTENDED CHANCE FOR DRIZZLE MENTION WITH THIS THOUGH 88D HAS BEEN QUIET OF ECHOES THUS FAR. CURRENT WIND SPEED REPORTS AND FAVORABLE ERLY DIRECTION OFF THE LAKE HAVE LED TO ISSUANCE OF A SMALL CRAFT ADVISORY FOR FAR WRN SUPERIOR THIS AFTN. SFC HIGH PRESENTLY LOCATED JUST NE OF THE ARROWHEAD AND RETURN FLOW HAS ACTUALLY BEGAN TO COMMENCE IN FAR WRN FA. BUT THE MSLP GRADIENT LOOKS TO SLACKEN OVERNIGHT AND ANY SITES REPORTING A SOUTHERLY COMPONENT IN WIND HAVE NOT SHOWN MUCH REACTION IN SFC TEMP. SO WITH KNOWLEDGE OF SOME OF THE MIN READINGS RECEIVED THIS MORNING /SUB 30 DEGREES IN THE SUPERIOR NATIONAL FOREST VALLEYS/ HAVE ISSUED A FROST ADVISORY FOR ENTIRE FA. MAIN CAVEAT AT THIS POINT IS FOR LAKE AND COOK COUNTIES WHERE STRATOCU OFF THE LAKE MAY CONTINUE INTO THE NIGHT. && .PREV DISCUSSION... (ISSUED 300 AM CDT SAT SEP 9 2006) DISCUSSION...FORECAST FOCUS IS ON HEADLINES TONIGHT. 06Z SFC ANALYSIS PLACED A SFC HIGH CENTER IN SW ONTARIO JUST N OF THE MN BORDER. SATELLITE IMAGERY REVEALED SC DECK STREAMING OFF OF LAKE SUPERIOR INTO THE HEAD OF THE LAKE AND THE SOUTH SHORE. ALSO SOME PATCHY FOG SHOWING UP IN THE OBSERVATIONS. EXPECT THESE CLOUDS TO PERSIST THROUGH THE MORNING HOURS OVER THE SAME AREA. NAM IS THE ONLY MODEL GENERATING QPF FROM THE CLOUDS. SINCE SOME THIN BANDS OF LAKE EFFECT -SHRA DID OCCUR ACROSS BAYFIELD COUNTY ACCORDING TO THE DAY SHIFT. WILL LEAVE THE SMALL POP IN PLACE AND JUST ADJUST THE WORDING. MOSTLY SUNNY SKIES EXPECTED ELSEWHERE. THE HIGH IS FIRMLY IN CONTROL TONIGHT. TEMPERATURES THIS MORNING HAVE ALREADY DROPPED INTO THE LOW 30S OVER MUCH OF THE FA. WILL SEE THE LOW TO MID 30S IN MOST AREAS. SOME UNCERTAINTY IN THE CLOUD COVER TONIGHT AS AN UPPER LEVEL TROF PASSES JUST TO THE N OF THE FA. WILL ISSUE A FROST ADVISORY FOR ALL OF NW WI EXCEPT BURNETT COUNTY WHERE TEMPS WILL BE A BIT WARMER. UPPER LEVEL RIDGE/SFC RIDGING HOVER NEAR THE FA THROUGH WEDNESDAY. NEXT CHANCE OF RAIN COMES WEDNESDAY NIGHT AS A WEAK FRONT MOVES THROUGH THE AREA AS UPPER LEVEL FLOW BECOMES MORE ZONAL. && .DLH WATCHES/WARNINGS/ADVISORIES... MN...FROST ADVISORY FROM 1 AM TO 7 AM CDT SUNDAY FOR CARLTON/SOUTHERN ST. LOUIS-CENTRAL ST. LOUIS-CROW WING-KOOCHICHING-NORTHERN AITKIN-NORTHERN CASS-NORTHERN COOK/NORTHERN LAKE-NORTHERN ITASCA-NORTHERN ST. LOUIS-PINE-SOUTHERN AITKIN-SOUTHERN CASS-SOUTHERN ITASCA. WI...FROST ADVISORY FROM 1 AM TO 7 AM CDT SUNDAY FOR ASHLAND-BAYFIELD- BURNETT-DOUGLAS-IRON-PRICE-SAWYER-WASHBURN. LS...SMALL CRAFT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR LSZ142- LSZ143-LSZ144-LSZ145-LSZ146-LSZ147. $$ BERDES mn AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 1126 AM CDT SAT SEP 9 2006 .UPDATE...FOR CLOUD COVER AND TEMPERATURES WE MODIFIED OUR GRIDS THROUGH TONIGHT TO ACCOUNT FOR LOWER TEMPERATURES AND MORE CLOUD COVER FOR SOME OF OUR CENTRAL AND SOUTHERN MN COUNTIES. && .PREV DISCUSSION... /ISSUED 325 AM CDT SAT SEP 9 2006/ DISCUSSION... REGION OF STRATUS CONTINUING TO SLOWLY ERODE ON ITS NORTHERN EDGE...HAVING CLEARED APPROXIMATELY THE NORTHERN QUARTER TO THIRD OF THE FORECAST AREA. THE CONTINUED PROGRESSION OF THIS CLEARING LINE WILL BE PROBLEMATIC FOR THE NEAR TERM. AT THIS TIME...EXPECT THAT THE WESTERN EDGE WILL BE QUICKER TO GIVE WAY THAN THE EASTERN EDGE /PER THE RUC 925 MB RH ANALYSES AND CURRENT SPLIT CHANNEL SATELLITE TRENDS/...SO HAVE KEPT SKY COVER FAIRLY HIGH TO THE SOUTHEAST OF A LINE FROM EAU CLAIRE TO FAIRMONT THRU THE AFTERNOON. LOW LEVEL COLD ADVECTION AND 850 MB TEMPS IN SINGLE DIGITS SHOULD ALSO KEEP TEMPERATURES WELL BELOW NORMAL...WITH HIGHS HOVERING NEAR 60 FROM LADYSMITH TO LONG PRAIRIE. NEXT ISSUE IS POSSIBILITY OF SOME PATCHY FROST TONIGHT ACROSS THE FAR NORTHERN PORTION OF THE FORECAST AREA. LOW TEMPS LOOK TO DIP INTO THE UPPER 30S TO THE NORTH OF A LINE FROM LITTLE FALLS...TO CAMBRIDGE...AND LADYSMITH...SO HAVE MENTIONED SOME PATCHY FROST TONIGHT IN THESE AREAS. SHORTWAVE TROUGH IS EXPECTED TO MOVE THROUGH THE CENTRAL PLAINS TONIGHT AND TOMORROW MORNING...AND THE 00Z NAM AND GFS ARE HAVING THEIR DIFFERENCES IN THE LEVEL OF ORGANIZATION OF THE ASSOCIATED SURFACE SYSTEM...WHICH WILL HAVE A FAIRLY SIZEABLE IMPACT ON PRECIPITATION CHANCES FOR SUNDAY THRU MONDAY MORNING. THE GFS DEVELOPS A CLOSED SURFACE LOW CENTERED NEAR KANSAS CITY BY 12Z SUNDAY...WHEREAS THE NAM ANALYZES A RATHER UNIMPRESSIVE SOUTHWEST TO NORTHEAST ORIENTED SURFACE TROUGH IN THE SAME LOCATION. PREVIOUS RUNS OF THE NAM HAVE FAVORED THE DEVELOPMENT OF THE CLOSED SURFACE LOW...AND THE LAST 3 RUNS OF THE GFS HAVE DEPICTED THE SAME...SO WILL FAVOR THIS SCENARIO. WITH THE MORE DEVELOPED SURFACE SYSTEM...AND DEEP HIGH PRESSURE REMAINING OVER NORTHERN MINNESOTA AND NORTHERN WISCONSIN AT THIS SAME TIME...AN AREA OF LOW AND MID LEVEL FRONTOGENESIS ORIENTS ITSELF ALONG THE MINNESOTA AND IOWA BORDER ON SUNDAY...AND ROTATES TO THE NORTHEAST INTO WESTERN WISCONSIN BY MONDAY MORNING AS CLOSED 700 MB LOW CENTER DOES LIKEWISE. THIS WILL BRING A CHANCE OF SHOWERS TO SOUTHERN AND SOUTHEASTERN SECTIONS OF THE FORECAST AREA...ALTHOUGH ADMITTEDLY...THE BEST CHANCE OF PRECIPITATION SHOULD REMAIN TO THE SOUTH OF THE FORECAST AREA THROUGH THIS PERIOD. TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH MONDAY NIGHT WITH COLD AIR CONTINUING TO FILTER INTO THE FORECAST AREA ON THE NORTH AND NORTHWEST SIDE OF THE CLOSED 700 MB LOW THAT WILL BE CENTERED NEAR THE SOUTHERN END OF LAKE MICHIGAN BY 12Z TUESDAY. LONGER TERM...TUESDAY THROUGH FRIDAY NIGHT THERE STILL REMAINS ALOT OF UNCERTAINTY WITH THE VARIOUS LONG TERM MODELS. PREFER THE LATEST ECMWF MODEL. THE GFS MODEL CONTINUES TO LACK RUN TO RUN CONSISTENCY. LONGWAVE UPPER RIDGE INITIALLY IN PLACE OVER THE WESTERN TWO THIRDS OF THE CONUS WILL SLOWLY PROGRESS EASTWARD OVER THE EASTERN U.S. DURG THE PERIOD. UPPER AIRFLOW BECOMES MORE ZONAL OVER THE UPPER MIDWEST AS UPPER TROUGH APPROACHES FROM THE WEST LATE IN THE PERIOD. DRY PERIOD AT THE ONSET FOLLOWED BY A CHANCE OF PRECIPITATION OVER THE UPCOMING WEEKEND. TEMPS MAINLY NEAR OUR SEASONAL AVERAGE FOR THE PERIOD. MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. $$ WET/KAT/JVM mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAS VEGAS NV 830 AM PDT SAT SEP 9 2006 .SYNOPSIS...ISOLATED THUNDERSTORMS WILL BE POSSIBLE ACROSS NORTHWEST ARIZONA THROUGH MONDAY AS MONSOON MOISTURE LINGERS ACROSS THE AREA. THE REMAINDER OF THE SOUTHERN GREAT BASIN WILL BE DRY WITH TEMPERATURES NEAR NORMAL. && .UPDATE...SHOWERS CURRENTLY HEADING OUT OF LINCOLN AND MOHAVE COUNTIES. ISSUED A NOW FOR LINCOLN TO HIGHLIGHT THE POTENTIAL FOR HEAVY RAIN AND GUSTY WINDS. REST OF CWA CURRENTLY LOOKING CLEAR. BASED ON RUC ANALYSIS FEEL THAT ANY CONVECTIVE ACTIVITY SHOULD BE CONFINED TO MOHAVE AND LINCOLN COUNTIES WITH ONLY VERY OUTSIDE CHANCES OVER HIGHER TERRAIN IN CLARK AND NYE. PW VALUES BEGIN A RAPID FALL BY THIS EVENING SIGNALING CALM AND DRIER CONDITIONS FOR SUNDAY ALTHOUGH ENOUGH MOISTURE MAY HANG INTO MOHAVE TO POP OFF A FEW STORMS. CURRENTLY AM NOT PLANNING ANY UPDATES TO THE PACKAGE. && .SHORT TERM...ISOLATED THUNDERSTORMS STILL GOING ACROSS MOHAVE COUNTY EARLY THIS MORNING. STORMS BEING DRIVEN BY SHORTWAVE CROSSING SOUTHERN NEVADA AND UPPER DIVERGENCE ASSOCIATED WITH JET EARLY THIS MORNING. LOOK FOR STORMS TO CONTINUE INTO THE MORNING HOURS ACROSS MOHAVE COUNTY AS SHORTWAVE CONTINUES TO MOVE EAST. SHORTWAVE NOT STRONG ENOUGH TO SCOUR MOISTURE OUT OF MOHAVE COUNTY AND BELIEVE STORMS WILL RE-FIRE THIS AFTERNOON OVER NORTHWEST ARIZONA AND NORTHEAST LINCOLN COUNTY. WE HAVE SEEN LOW LEVEL MOISTURE DRAWN NORTHWARD LAST EVENING INTO SOUTHERN NEVADA WHERE SURFACE DEWPOINTS HAVE CLIMBED BACK INTO THE UPPER 50S AROUND THE LAS VEGAS VALLEY. DON'T BELIEVE MOISTURE IS THAT DEEP AND WE SHOULD MIX OUT THIS AFTERNOON WITH DEWPOINTS FALLING INTO THE 40S SIMILAR TO CURRENT READING JUST UP THE ROAD AT INDIAN SPRINGS. FOR SUNDAY AND MONDAY...MOISTURE NEVER GETS SCOURED OUT OF SOUTHEAST THIRD OF FORECAST AREA AS GFS DEVELOPS REX BLOCK OVER THE INTERMOUNTAIN WEST MONDAY WITH HIGH CENTER OVER EASTERN IDAHO AND LOW CENTER OVER ARIZONA. LOW LEVEL EASTERLY AROUND ARIZONA LOW WILL KEEP PW VALUES ABOVE THREE QUARTERS OF AN INCH OVER THE SOUTHEAST THIRD OF THE AREA. NO SIGNIFICANT WINDS EXPECTED NEXT THREE DAY WHILE TEMPERATURES WILL BE CLOSE TO NORMAL. .LONG TERM...LITTLE CHANGE TO FORECAST AS MODELS ARE HAVING A TOUGH TIME DEPICTING THE DEVELOPMENT OF A CLOSED UPPER LOW DEVELOPING OVER THE PAC NW LATE NEXT WEEK. GFS SEEMS TO BE THE FASTEST AND DEEPEST WITH THE SYSTEM...WITH OTHER MODELS LAGGING BEHIND CONSIDERABLY. FOR NOW...THE NCEP MEAN ARGUES FOR A SLOWER AND SHALLOWER SYSTEM OVER NEXT WEEKEND. REGARDLESS OF THE MODEL...THE APPROACHING SYSTEM WILL TIGHTEN THE PRESSURE GRADIENT AND WE SHOULD EXPECT TO SEE AN INCREASE IN SOUTHWESTERLY WINDS FROM THURSDAY ONWARDS. TEMPERATURES WILL WARM TO A FEW DEGREES ABOVE NORMAL EARLY IN THE EXTENDED...WITH RISING HEIGHTS AND DRIER CONDITIONS BENEATH THE RIDGE. EXPECT TO SEE SOME DEGREE OF COOLING TOWARDS THE END OF THE EXTENDED AS HEIGHTS FALL DEPENDING ON THE TIMING AND LOCATION OF THE UPPER LOW. && .AVIATION...ISOLATED THUNDERSTORMS WILL OCCUR IN THE PEACH SPRINGS CORRIDOR TODAY. THE REMAINDER OF THE APPROACH/DEPARTURE CORRIDORS WILL BE CLEAR OF THUNDERSTORMS. TAFS AND TWEBS ADEQUATELY DESCRIBE EXPECTED WEATHER CONDITIONS FOR AREA TERMINALS. SEE TAFS FOR KLAS...KVGT...KDRA...KBIH...KDAG...KEED...FOR DETAILS. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. .VEF WATCHES/WARNINGS/ADVISORIES... .NV...NONE .AZ...NONE. .CA...NONE. $$ BELL/PIERCE/MOSES HTTP://WEATHER.GOV/LASVEGAS nv AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE UPTON NY 357 PM EDT SAT SEP 9 2006 .NEAR TERM (THROUGH SUNDAY)...CURRENTLY WATCHING A LINE OF SHOWERS AND TSTMS MOVING EAST ACROSS NORTHEAST PA AT AROUND 15 KT. AT THIS CURRENT MOTION...THE STORMS COULD AFFECT ORANGE COUNTY AS EARLY AS 22Z...AND REACH PUTNAM AND WESTERN PASSAIC BY 00Z. SPC 19Z MESOANALYSIS SHOWED STORMS WERE ASSOCIATED WITH WEAK THETA-E RIDGE AHEAD OF APPROACHING SURFACE COLD FRONT...WITH MLCAPE OF 500-1000 J/KG WITH AROUND 25 KT OF WIND AT H5...SO A STORM OR TWO COULD MANAGE TO PRODUCE GUSTY WINDS AND SOME HAIL. AREAS FARTHER SOUTH/EAST ARE RATHER DRY AT H8 AND RUC SOUNDINGS LOOK CAPPED...SO WOULD ONLY EXPECT A SHOWER OR TWO...POSSIBLY A TSTM...ELSEWHERE NORTH AND WEST OF NYC. COLD FRONT DROPS THROUGH THE AREA LATER TONIGHT...AND WE PREFER SLIGHTLY SLOWER NAM TIMING. CLOUDS LINGER BEHIND THE FRONT SO WILL CALL IT PARTLY CLOUDY THROUGH SUNDAY MORNING...FOLLOWED BY A MOSTLY SUNNY AFTERNOON. MAX TEMPS WILL BE ABOUT 5-10 DEGREES COOLER THAN THOSE OF TODAY...LOWER AND MID 70S AS OPPOSED TO THE MID 70S TO MID 80S OF TODAY. && .SHORT TERM (SUNDAY NIGHT THROUGH TUESDAY)...DRY WX WILL CONTINUE AS A LARGE HIGH PRESSURE SYSTEM BUILDS OUT OF CANADA. MAIN CONCERNS WILL BE HOW COOL DO NIGHTTIME TEMPS GET INLAND...AND HOW MUCH WIND WILL THERE BE ESPECIALLY IN COASTAL SECTIONS FROM INTERACTION BETWEEN THE HIGH AND FLORENCE...WHICH IS FORECAST TO PASS VERY NEAR BERMUDA AND THEN RECURVE OFF TO THE NORTHEAST. FOR TEMPS HAVE STAYED CLOSE TO MAV NUMBERS FOR MINS WHICH ARE MAINLY IN THE 40S INLAND AND 50S AT THE COAST...WITH SOME UPWARD ADJUSTMENTS MON NIGHT IN COASTAL SECTIONS WHERE NE FLOW SHOULD PREVENT DECOUPLING. MAY HAVE TO REVISIT MIN TEMPS FOR SHELTERED INLAND AREAS WHICH COULD DROP CLOSE TO 40 MON NIGHT...IN ANY CASE THEY SHOULD REMAIN ABOVE FROST ADVISORY CRITERIA. WINDS WILL TURN NE ON MON AS A PORTION OF THE HIGH NOSES DOWN THE MID ATLANTIC COAST...AND AS FLORENCE PASSES OFF TO THE SOUTHEAST. MAIN IMPACT FROM WINDS WILL BE FELT OVER LONG ISLAND AND COASTAL CT...WHERE THEY COULD PICK UP TO 10-20 MPH SUSTAINED WITH GUSTS UP TO 30 MPH. THESE WINDS WILL GRADUALLY DECREASE ON TUE AS FLORENCE HEAD NE OUT INTO THE OPEN ATLANTIC AND PULLS FARTHER AWAY FROM THE AREA. SEE THE MARINE SECTION BELOW FOR POTENTIAL SURF AND COASTAL FLOODING IMPACTS. && .LONG TERM (TUESDAY NIGHT THROUGH SATURDAY)...HIGH PRESSURE OVER THE AREA TUE NIGHT AND WED WILL SHIFT E OFF THE NEW ENGLAND COAST WED NIGHT...WITH AN E-NE FLOW GRADUALLY TURNING SE BETWEEN THE HIGH AND WEAK LOW PRESSURE APPROACHING FROM THE OH VALLEY. INTRODUCED A CHANCE OF SHOWERS WED NIGHT INTO THU NIGHT WITH THE APPROACH OF THE LOW...ALSO SOME PATCHY FOG THU NIGHT IN SECOND NIGHT OF SE FLOW OF MARITIME AIR...AND INTO EARLY FRI MORNING WITH ONLY LIGHT N-NW FLOW BEHIND DEPARTING LOW. HIGH PRESSURE RETURNS FOR FRI AND SAT WITH WARMING TEMPS. A WARMUP TO MORE SUMMERLIKE TEMPS COULD BE IN STORE FOR NEXT WEEKEND...POSSIBLE FLY IN THE OINTMENT VERY LATE IN THE PERIOD OR JUST BEYOND INTO SUN-MON COULD BE BACK DOOR COLD FROPA...DEPENDING UPON STRENGTH OF DEEP CLOSED LOW PROGGED TO BE IN PLACE NEAR THE DAVIS STRAIT AND GREENLAND AT THAT TIME. MY BET IS THE NW FLOW OVER EASTERN CANADA AS DEPICTED BY THE GFS IS PROGGED TO BE TOO STRONG AND THAT WE WILL STAY WARM. && .AVIATION...SCATTERED CONVECTION OVER SOUTH CENTRAL NY STATE...NE PA...AND NRN NJ...ALONG AND AHEAD OF A PRE-FRONTAL TROUGH...WILL DROP SE TOWARD THE FORECAST AREA THIS AFTERNOON. OUT AHEAD OF IT...LARGELY VFR CONDITIONS WERE BEING OBSERVED WITH A FEW TERMINALS REPORTING MVFR HAZE AND SCT CU. THE SURFACE COLD FRONT WILL APPROACH THE TERMINALS THIS EVENING...AROUND 00Z SWF...02Z NYC METRO...AND 03Z TO 04Z FOR THE EASTERN TERMINALS. CONFIDENCE IS LOW FOR CONVECTION AT ANY ONE TERMINAL...BUT WILL CARRY A CB GROUP AT KSWF AS THIS TERMINAL LIES IN AN AREA OF GREATER INSTABILITY. WINDS WILL VEER AROUND TO THE NW AND EVENTUALLY N BY DAYBREAK. ON SUN...WINDS WILL CONTINUE TO VEER AROUND TO NE AS HIGH PRESSURE BUILDS SOUTHEAST ACROSS EASTERN CANADA...WHILE T.S. FLORENCE TRACKING TO THE NW PICKS UP FORWARD SPEED OVER THE WESTERN ATLANTIC. && .MARINE...NO FLAGS EXPECTED ON THE WATERS THROUGH MIDDAY SUN...BUT CONDITIONS WILL GO DOWNHILL THEREAFTER. IN THE NEAR TERM...A COLD FRONT WILL APPROACH FROM THE NORTHWEST THIS EVENING AND CROSS THE WATERS OVERNIGHT...WITH WINDS VEERING FROM SW TO N AFTER MIDNIGHT. WIND SPEEDS SHOULD REMAIN LESS THAN 15 KT THROUGH THE FROPA. NOT EXPECTING ANY SIGNIFICANT TSTM ACTIVITY OVER THE WATERS WITH THE FRONT. FOCUS THEN TURNS TO MARINE EFFECTS FROM TROPICAL STORM FLORENCE. THE WNA AND NAH GUIDANCE ARE IN GOOD AGREEMENT THAT LONG PERIOD SE SWELL FROM FLORENCE WILL BEGIN TO MOVE INTO THE COASTAL WATERS TONIGHT... BUT SEAS WILL REMAIN BELOW SCA LEVELS UNTIL SUNDAY AFTERNOON. SEAS WILL BECOME RATHER ROUGH DURING THE DAY WITH NORTH WINDS OF 10-15 KT PRODUCING WIND WAVES WHICH WILL BE CLASHING WITH THE INCREASING SE SWELL. EXPECT ROUGH CONDITIONS TO DEVELOP AT INLETS AS WELL DUE TO THE LONG PERIOD SWELL. WINDS AND SEAS WILL INCREASE FURTHER SUN NIGHT AS SWELLS FROM FLORENCE CONTINUE AND THE PRESSURE GRADIENT TIGHTENS BETWEEN HIGH PRESSURE OVER SE CANADA AND THE LARGE CIRCULATION OF FLORENCE WELL OFFSHORE. NE WINDS OF 15-25 KT WILL BE POSSIBLE ACROSS THE EASTERN OCEAN ZONES DURING THIS TIME...ALONG WITH SEAS BUILDING TO 6-7 FT. PRESSURE GRADIENT REMAINS TIGHT MON AND MON NIGHT WITH BRISK NE FLOW CONTINUING. GRADIENT THEN RELAXES TUE AND BEYOND AS THE HIGH BUILDS INTO NORTHERN NEW ENGLAND AND FLORENCE MOVES NORTH OF BERMUDA. SWELLS WILL REMAIN A PROBLEM HOWEVER...WITH THE HIGHEST SEAS EXPECTED MON AFTERNOON THROUGH TUE MORNING WHEN SIG WAVE HGTS OF 7-10 FT WILL BE LIKELY ACROSS THE OCEAN ZONES. HAVE GONE AHEAD AND POSTED SCA FOR THE OCEAN ZONES...BEGINNING SUN AFTERNOON. THIS WILL LIKELY BE A LONG DURATION SCA AS SEAS WILL REMAIN HIGH FOR SEVERAL DAYS. AFTER SUN MORNING...THU WILL PROBABLY BE THE NEXT DAY WHEN SEAS ARE BELOW 5 FT ON THE OCEAN. WITH HIGH SEAS AND A LONG DURATION NE FETCH EXPECTED FROM SUN EVENING THROUGH TUE...WOULD EXPECT A VARIETY OF PROBLEMS TO DEVELOP ALONG THE COAST INCLUDING HIGH SURF...DANGEROUS RIP CURRENTS...AND SOME MINOR COASTAL OVERWASH AND FLOODING. COASTAL FLOODING WILL BE MOST LIKELY ACROSS THE BACK BAYS OF THE LONG ISLAND SOUTH SHORE BEGINNING SUN NIGHT. LOCALLY MODERATE COASTAL FLOODING WOULD NOT BE OUT OF THE QUESTION...ESPECIALLY DURING THE HIGH TIDE CYCLES MON THROUGH TUE. && .HYDROLOGY...SCATTERED TSTMS ENTERING ORANGE COUNTY INTO THIS EVENING COULD PRODUCE A BRIEF DOWNPOUR OF 1/4 TO 1/2 INCH...WITH LOCALIZED PONDING OF WATER. OTHERWISE...NO PROBLEMS ARE EXPECTED OVER THE NEXT WEEK. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NJ...NONE. NY...NONE. MARINE...SCA FOR ANZ350-353-355 FROM 3 PM SUN TO 6 PM WED. && $$ PUBLIC...GOODMAN AVIATION...DSW MARINE...CNJ ny AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE GRAND FORKS ND 940 AM CDT SAT SEP 9 2006 FORECAST CHALLENGE CONCERNS CLOUD TRENDS AND TEMPERATURES. BAND OF VIRGA/-SHRA PROPAGATING SE ACROSS W/CENTRAL ND ALONG 850MB BAROCLINIC ZONE AIDED BY SHORTWAVE DROPPING OVER WESTERN RIDGE. TRAJECTORY...DRY COLUMN AND STABLE AIRMASS OVER FA SHOULD KEEP ANY PCPN W AND S OF FORECAST AREA. OTHERWISE RIBBON OF CLOUDS ORIGINATING FROM LAKE SUPERIOR WILL AFFECT A SMALL PORTION OF NW MN WHICH ACTUALLY IS HANDLED PRETTY WELL BY RUC. LASTLY NORTHERN FRINGE OF CLOUD SHIELD FROM CENTRAL PLAINS UPPER LOW MAY JUST SKIM FAR SOUTHERN FA ALONG ND/MN/SD BORDER AREA. REMAINDER OF FA SHOULD SEE PLENTY OF SOLAR WITH CONVECTIVE TEMPERATURES AROUND 90F. COOL START WITH MANY LOCATIONS SEEING MINIMUM TEMPERATURES IN THE 30S HOWEVER TEMPERATURES RECOVERING WELL SO ANTICIPATED HIGH TEMPERATURES SEEM REASONABLE. ONLY MINOR CHANGES PLANNED TO ONGOING FORECAST. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ VOELKER nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CLEVELAND OHIO 708 AM EDT SAT SEP 9 2006 .AVIATION(12Z-12Z)... MAIN FACTOR WILL BE PRECIP ASSOCIATED WITH COLD FRONTAL PASSAGE THIS MORNING/AFTERNOON. SURFACE FRONT CURRENTLY JUST NORTH OF LAKE ERIE...HOWEVER MAJORITY OF PRECIP STILL BEHIND THE FRONT OVER CENTRAL MICHIGAN. HAVE NOTED MORE AND MORE SHOWERS POPPING UP OVER THE LAKE SINCE 4AM...RUC SHOWING A WEAK THETA-E RIDGE JUST AHEAD OF THE FRONT...THIS COMBINED WITH RELATIVELY UNSTABLE AIR OVER THE LAKE THE LIKELY CAUSE OF THESE SHOWERS. CLE/DTX RADAR CURRENTLY SHOWING A WEAK BOUNDARY OVER THE SOUTHERN SHORE OF THE LAKE...PUSHING INLAND AND SPAWNING ADDITIONAL SHOWERS AND THUNDERSTORMS. GIVEN WIDELY SCATTERED NATURE OF THESE SHOWERS...WILL ONLY GO WITH VCSH AT ALL THE TERMINALS THROUGH MID MORNING AND HOLD OFF ON INTRODUCING TEMPOS FOR THUNDER UNTIL EARLY AFTERNOON WHEN DAYTIME HEATING WILL ALLOW FOR ADDITIONAL SHOWERS AND THUNDERSTORMS TO DEVELOP. BACKED OFF ON IFR VSBYS FOR THIS AFTERNOON...ANY HEAVY RAIN WOULD BE BRIEF IN NATURE BUT COULD SEE BRIEF PERIODS OF MVFR VSBYS WITHIN HEAVIEST SHOWERS. AS FOR AFTER 00Z...BIT OF A CONFLICT BETWEEN MOS GUIDANCE AND RAW MODEL OUTPUT IN TERMS OF CEILINGS...MOS KEEPS CIGS VFR...RAW MODEL OUTPUT BRINGS IN LOW CIGS UNDER 1000FT. SINCE CIGS ARE ALREADY WELL BELOW 1000FT BEHIND THE FRONT AT THE MOMENT...AM INCLINED TO BRING THESE LOW CEILINGS INTO OUR TERMINALS THIS EVENING. && .SHORT TERM UPDATE (TODAY)... UPDATED TO REMOVE TIMING FOR SHOWERS AND THUNDERSTORMS AND TO ADD CLOUD TRENDS. && .SHORT TERM (TODAY THRU MON NIGHT)... CDFNT FM SRN LK MI NE THRU THE FLINT MI VCNTY. ETA12 DROPS IT INTO NRN OH/NWRN PA BTWN 12-15Z. MANUAL POSITIONS SUGGEST THE FRONT CLEARS THE AREA TO THE SOUTH BY 18Z ALTHOUGH 18Z ETA12 PROG HANGS THE BOUNDARY UP IN THE NW AS A WK WV DEVLPS...SUGGESTING THE POSITION MAY BE CLOSER TO A KDFI-KPHD LINE. MOST OF THE CLOUD COVER AND PCPN IS ALG AND POST FRONT ALTHOUGH NERN OH/WRN PS HAS SEE SCT SHWRS/TSTMS OVRNGT. WL NEED TO INCLUDE A TREND IN CLOUDS TDA SINCE WE SHOULD SEE SOME SS AT LEAST TO START OUT WITH. COULD ALSO END UP WITH A PARTLY SUNNY AFTERNOON BUT WILL TREND WITH INCRSG CLOUDS MOST AREA...AND TO MC IN THE NERN ZONES. XPC MOST OF THE PCPN FROM LATE MORNING ON ALTHUGH CANNOT DISCOUNT CRNT ACTVTY. CDFNT DROPS SOUTH OF THE AREA THIS EVG/TNGT AND EVENTUALLY STALLS ACRS THE LOWER OH VLY AS THE SFC HIGH TO OUR NORTH DRIFTS E ACRS THE GRTLKS. ENSEMBLE MEAN BUILDS THE HIGH A BIT FURTHER SOUTH-EAST THAN THE OPERATIONAL MDLS WHICH WOULD TEND TO BRING IN DRIER AIR TO THE AREA SPCLY NE THRU THE SHORT TERM. NGM/NAM/GFS IN GNRL AGREEMENT HWVR IN THAT ALL THREE SHOW A GOOD AMOUNT OF MSTR ACRS THE AREA TNGT THROUGH MONDAY NIGHT...ENOUGH TO GO WITH MOSTLY CLOUDY THRU MUCH OF THE SHORT TERM. BEST CHC FOR PC WOULD BE ACRS THE FAR NE SO WILL PLACE IN FCST THERE SUNDAY THRU MONDAY. AS FOR PCPN WL CONTINUE WITH CHC POPS TNGT POST FRONT AND THEN DRY OUT THE AREA FOR SUNDAY. SUNDAY NIGHT WILL BRING CHC POPS BACK INTO THE NW AS SYSTEM IN THE CNTRL PLAINS MOVES TWRD THE OH VLY. MONDAY GFS AND NAM BOTH SHOWING THE FRONT MOVG BACK INTO THE AREA AHEAD OF THE SFC LOW WITH DP MSTR IN PLACE. WL CONT POPS MONDAY NIGHT AS WELL. && .LONG TERM TUESDAY THROUGH FRIDAY)... TUES THRU THURSDAY LOOKS MOIST AND UNSTABLE AS THE GFS DVLPS AN UPPR LOW ACRS THE GRTLKS. WL NEED TO KEEP CHC POPS IN THE FCST THRU AT LEAST WEDNESDAY AND CONTINUE MC SKIES THRU THURSDAY. THURSDAY NIGHT INTO FRIDAY XPC CLRG AS LOW MOVES EAST OF THE AREA. NO BIG CHG IN TEMPS. && .CLE WATCHES/WARNINGS/ADVISORIES... .OH...NONE. .PA...NONE. && $$ SHORT TERM...TK LONG TERM...TK AVIATION...LEINS oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ABERDEEN SD 930 PM CDT SAT SEP 9 2006 SAT PIX SHOW INCREASING MID/HI LEVEL CLOUDINESS SPREADING OVER CWA IN RESPONSE TO UPPER/SFC LOWS SOUTH OF CWA. LOW CLOUDS LOOK ABOUT READY TO PUSH BACK INTO KPIR. LATEST RUC 925MB RH PLOT AGREES WITH LOW CLOUDS OVERSPREADING CWA BY 09Z CWA WIDE. TWEAKED CLOUD GRIDS TO BETTER MATCH CURRENT CONDS. ALSO...CURRENT TEMPS ACROSS NE SD ARE WITHIN A FEW DEGREES OF FCSTD LOWS...BUT INCREASING CLOUDS SHOULD PUT A HALT TO THE FALL. NEEDED TO TWEAK HOURLY TEMP GRIDS AS WELL. REMAINDER OF GRIDS LOOKED OK. ...PREVIOUS DISCUSSION... .SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT FORECAST CHALLENGE CONTINUES TO BE CLOUDS AND TEMPS. PRESENTLY HAVE COOL CANADIAN HIGH PRESSURE CENTERED OVER ONTARIO...WITH STRATUS CLOUDS DISSIPATING ACROSS THE FORECAST AREA EXCEPT OVER THE BUFFALO RIDGE. THE 12Z GFS/NAM-WRF SOLUTIONS WERE...AGAIN...SIMILAR TODAY WITH UPPER FLOW AND HANDLING OF S/WS OVER THE REGION...LEAVING THIS FORECAST AREA DRY. WEAK BAROCLINIC ZONE SETTING UP IN WEAK WAA ALOFT OVER EASTERN MONTANA AND WESTERN SOUTH DAKOTA IS GENERATING SOME ISOLATED THUNDERSTORMS. THIS BAROCLINIC ZONE MAY EVENTUALLY MAKE IT DOWN HERE BY MONDAY...BUT LEAVING THE FORECAST DRY FOR NOW. NEXT...ATTENTION TURNS TO THIS PERSISTENT LOW LEVEL THERMAL INVERSION AND SHALLOW COOL AIR INTRUSION THAT HAS SET UP ACROSS THE NORTH CENTRAL STATES BEHIND THE COLD FRONT THAT PASSED SOUTHWARD THROUGH THIS REGION BACK ON THURSDAY NIGHT AND NOW SITS STATIONARY ACROSS NEBRASKA AND IOWA. WITHOUT ANY SIGNIFICANT LOW LEVEL DRY AIR INTRUSIONS TO SCOUR OUT THE MOISTURE TRAPPED UNDER THE INVERSION...SHOULD BE LOOKING AT A THIRD DAY OF STRATUS FUN ON SUNDAY...BURNING OFF BY AFTERNOON...AND THEN REDEVELOPING AGAIN SUNDAY NIGHT INTO MONDAY MORNING. THIS THEME MAY EVEN NEED TO BE REPEATED INTO TUESDAY. FOR NOW...THOUGH...DETERMINED TO CLEAR THINGS OUT ON TUESDAY AS RETURN FLOW SETS UP IN RESPONSE TO APPROACHING S/W ENERGY OVER THE ROCKIES ON DAY 3. TEMPERATURES WHERE THE MOST DIRECT INSOLATION OCCURS COULD SEE 70S...BUT AREAS THAT REMAIN SOCKED IN UNDER LOW STRATUS CLOUDS WILL LIKELY NOT SEE TEMPERATURES REBOUND MUCH PAST MID 60S. .LONG TERM...WEDNESDAY THROUGH SATURDAY GOOD AGREEMENT AMONGST THE MODELS WITH THE LONG WAVE FLOW PATTERN FOR WEDNESDAY THROUGH SATURDAY. THE PERIOD BEGINS WITH WEST TO WEST NORTHWEST FLOW AT 50H OFF THE PACIFIC ACROSS THE UPPER MIDWEST WITH LARGE TROUGHING IN WESTERN CANADA AND OFF THE COAST. THROUGH THE FORECAST PERIOD...THE TROUGHING DROPS INTO THE WESTERN US AND WESTERN CANADA...CLOSES OFF AND INTENSIFIES AS UPPER RIDGING DEVELOPS TO THE EAST ACROSS THE CENTRAL PART OF THE US. WITH THIS OCCURRING...SURFACE LOW PRESSURE WILL DEEPEN OFF TO THE NORTHWEST OF OUR CWA WITH WARMER AND MORE MOIST AIR BEING DRAWN INTO THE REGION. ALSO...COULD SEE SOME WINDY CONDITIONS AS SURFACE PRESSURE GRADIENT WILL TIGHTEN UP ALONG WITH LLJ INCREASING. HAVE UPPED TEMPERATURES THROUGH THE ENTIRE PERIOD. WOULD NOT DOUBT THEY WILL HAVE TO BE INCREASED MORE AS WARM THICKNESSES BUILD IN. ALSO...HAVE SOME 20 POPS IN THROUGH MUCH OF THE FORECAST AS SHORT WAVES ROLL IN OFF THE WESTERN UPPER LOW. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ HINTZ/DORN/MOHR sd AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE ABERDEEN SD 1108 AM CDT SAT SEP 9 2006 .UPDATE...MORNING UPDATE TO LOWER MAX T VALUES ACROSS SOUTHWESTERN FA WHERE LOW CLOUDS ARE EXPECTED TO HANG IN FOR MUCH OF THE TODAY PERIOD...RESULTING IN LESS EFFECTIVE DAYTIME HEATING. ALSO UPDATED SKYCOVER GRIDS TO CAPTURE CURRENT AND EXPECTED 6-HOURLY TREND...BASED OFF COLLABORATION AND RUC 925HPA RH SOLUTION. UPDATED WORDS/GRIDS ARE OUT. DORN && .PREV DISCUSSION... (ISSUED 335 AM CDT SAT SEP 9 2006) SHORT TERM...TODAY THROUGH MONDAY NIGHT CHALLENGES IN THE SHORT TERM CONTINUE TO BE CLOUD COVER AND RESULTANT TEMPERATURES. STRATUS LAYER CONTINUES TO EDGE WESTWARD INTO EASTERN SD EARLY THIS MORNING WITH THE DECK STRETCHING EAST INTO WISCONSIN. ABR WAS DOWN TO BKN008 DURING THE PAST 30 MINUTES WITH CEILINGS AROUND 1000 FT FARTHER EAST TOWARDS THE SD/MN BORDER. RUC/NAM/GFS ALL SHOWING HIGH RH AT 925 MB PUSHING INTO THE AREA THROUGH SUNRISE...BUT DRIES THINGS OUT THROUGHOUT THE MORNING. MODELS HAVE BEEN IFFY AT HANDLING CLOUD COVER THE PAST FEW DAYS BUT SEEM TO BE DOING OK THIS MORNING. QUESTIONS FOR THE DAY WILL BE JUST HOW MUCH CLOUD COVER MAKES IT INTO THE ABR CWA AND HOW LONG WILL IT LAST. MODELS WOULD SUGGEST STRATUS BREAKING UP DURING THE MORNING...WITH THE MORE MOIST AIR AT 925/850 MB ACROSS SOUTHERN SD. HAVE THEREFORE CONSTRUCTED SKY COVER GRIDS TO REFLECT MORE CLOUDS FURTHER SOUTH IN THE CWA. UPPER WAVE OVER CO/WY THIS MORNING WILL CONTINUE TO ADVANCE EAST INTO THE PLAINS THROUGH TONIGHT...AND STILL APPEARS TO STAY SOUTH OF OUR AREA. ALTHOUGH...THE SOUTHERN PORTION OF THE CWA WILL MORE THAN LIKELY SEE CLOUD COVER IN ASSOCIATION WITH THIS SYSTEM. MODELS TRYING TO SUGGEST SOME STRATUS CLOUD COVER EACH NIGHT THROUGH MONDAY MORNING BUT WITH THE RECENT STRUGGLES THE MODELS HAVE HAD WITH CLOUDS...HAVE OPTED TO PLAY IN CONSERVATIVE FOR NOW UNTIL FUTURE SHIFTS CAN TRY TO NAIL IT DOWN BETTER. AS FOR TEMPERATURES...BUMPED UP HIGHS A FEW DEGREES ACROSS THE EAST TODAY AND SUNDAY. SHORT TERM STAYS DRY AS THE WAVE PULLING OUT INTO THE CENTRAL PLAINS REMAINS TO THE SOUTH. LONG TERM...TUESDAY THROUGH SATURDAY MEDIUM RANGE MODELS ARE CHANGING AGAIN SO CONFIDENCE IS LOW. THE PERIOD OPENS WITH A RETREATING UPPER LOW MOVING THROUGH ILLINOIS WHILE AN UPPER RIDGE TILTS ACROSS THIS AREA. RIDGE QUICKLY GETS FLATTENED INTO FAST WESTERLY FLOW WITH OLD BAROCLINIC ZONE IN SOUTHERN CANADA. AS THE NEXT PACIFIC LOW PUSHES ONSHORE THE PACIFIC COAST THURSDAY THE OLD FRONTAL BOUNDARY SINKS SOUTH AND IS OVER THE AREA BY THURSDAY AFTERNOON. KEPT A SLIGHT CHANCE CATEGORY POP OVER MUCH OF THE AREA THURSDAY AND FRIDAY AS THIS FRONT WILL DRAPE ACROSS CENTRAL SOUTH DAKOTA WITH SOUTHWEST FLOW ALOFT OVER IT. THERE IS A GOOD MOISTURE FETCH FROM THE SOUTH AT THE LOW LEVELS. DO NOT THINK THIS WILL MAKE THIS A BIG EVENT BUT MAY PROVIDE ENOUGH MOISTURE TO EVEN GET A THUNDERSTORM GOING. DID NOT WORD FOR THUNDERSTORM IN THE GOING GRIDS. WITH UPPER RIDGE OVER THE AREA IN THE BEGINNING OF THE PERIOD DID BUMP TEMPERATURES UP A LITTLE. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ TARVER/KEEFE sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NASHVILLE TN 1050 PM CDT SAT SEP 9 2006 .DISCUSSION...JUST LIKE LAST NIGHT, LATE DAY PRECIPITATION WAS VERY SLOW TO DIMINISH AND LASTED UP UNTIL CLOSE TO MIDNIGHT. HOWEVER, BELIEVE WE ARE NOW PROBABLY SAFE TO UPDATE AND REMOVE MENTION OF OVERNIGHT PRECIPITATION (ESPECIALLY SINCE RUC ALSO INDICATES A DRY REMAINDER OF THE NIGHT). CAN'T RULE OUT A ROGUE SHOWER SOMEWHERE LATER TONIGHT, BUT COVERAGE SHOULD CERTAINLY BE INSIGNIFICANT ENOUGH TO LEAVE OUT OF THE FORECAST. EXPECT TO GET THE NEW UPDATE OUT ON THE WIRE SHORTLY. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 19 tn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX 845 PM CDT SAT SEP 9 2006 .DISCUSSION...SATELLITE AND RADAR IMAGES INDICATED SHOWERS ACROSS SOUTHWEST PORTIONS OF THE CWA THIS EVENING. WEAK 500MB SHORTWAVE TROUGH ACROSS EAST TEXAS MOVING EASTWARD IN THE WESTERLY FLOW ALOFT. PRECIPITABLE WATER VALUES REMAIN NEAR OR SLIGHTLY ABOVE TWO INCHES ACROSS THE MIDDLE AND UPPER TX COAST. WATER VAPOR SAT IMAGES INDICATE A COUPLE OF WEAK VORTICITY MAXIMUM CENTERS ACROSS DEEP SOUTH TX AND WEST TX. BELIEVE THESE FEATURES WILL MOVE EASTWARD TONIGHT PROVIDING ANOTHER ROUND OF CONVECTION LATE TONIGHT INTO EARLY SUNDAY. WILL GO AHEAD AND LOWER POPS THIS EVENING AS THE TROUGH OVER EAST TX CONTINUES TO MOVE EASTWARD BUT KEEP POPS LATE TONIGHT AS THE WEAK TROUGH TO THE WEST APPROACHES SOUTHEAST TX. 32 && .PREV DISCUSSION... (ISSUED 256 PM CDT SAT SEP 9 2006) SHRA/TSRA CLUSTER ASSOCIATED WITH MCV MOVING ENE ACROSS UPPER TEXAS COAST AND COASTAL ZONES. SCATTERED CONVECTION DEVELOPING OVER FAR SOUTH TEXAS PICKED UP BY 18Z RUC AND WEAKEN THIS ACTIVITY BY EVENING. BELIEVE THIS MAY STILL STILL AFFECT COASTAL WATERS AND TO A LESSER EXTENT COASTAL ZONES. UPPER LEVEL FLOW NEARLY ZONAL ACROSS BOTH GFS AND NAM INDICATE COASTAL REGION WILL HAVE WEAK CONFLUENT LOW LEVEL FLOW THROUGH EARLY NEXT WEEK. CONFIDENCE IS NOT HIGH WITH THIS UPCOMING FORECAST PACKAGE. NAM DID NOT INITIALIZE WELL AND GFS HAS CHANGED THE SCENARIO FOR THE NEXT SEVERAL DAYS COMPARED TO PREVIOUS RUN. LATEST GFS RUN HAS BACKTRACKED ON MOISTURE/POPS NEXT SEVERAL DAYS LOWERING PWATS LATER THIS WEEKEND AND INTO NEXT WEEK DUE TO DRYING AT MID/UPPER LEVELS. NAM IS LESS AGGRESSIVE. GFS NOW BRINGING DRIER LOW LEVEL AIR 24 HOURS EARLIER WHICH WILL BE TUESDAY PUSHING WEAK FRONT TO THE NW GULF. MOISTURE INCREASE NOTED WEDNESDAY NIGHT OVER SW SECTIONS AND RETURN FLOW EVIDENT AREAWIDE THURSDAY. THURSDAY THROUGH SATURDAY AGAIN WILL HAVE HIGH MOISTURE LEVELS WITH PASSING IMPULSES IN THE UPPER LEVEL WSW FLOW. NOTE THAT WE WILL WAIT FOR MORE CONSISTENCY WITH LATER MODEL RUNS BEFORE WE LOWER OR TAKE OFF POPS FOR TUESDAY (AS WHAT GFS IS NOW INDICATING). 37 AVIATION... THE REMAINS OF A WEAK FRONTAL BOUNDARY CONTINUE TO PROVIDE A CONFLUENT ZONE OVER THE COASTAL WATERS AND ARE PROVIDING A REGION OF OVERRUNNING WITH LIGHT EASTERLY FLOW IN THE LOWER 4KFT OR SO WITH SOUTH TO SOUTHWEST FLOW AT HIGHER LEVELS. THIS IS SETTING THE STAGE FOR PATCHY LIGHT RAIN OVER MUCH OF THE FORECAST AREA AS A SHORT WAVE MOVES THROUGH THE SOUTHWESTERLY FLOW ALOFT... AND IS PRODUCING BRIEF PERIODS OF MVFR AND IFR CONDITIONS MAINLY SOUTH OF A LINE FROM VCT TO IAH. OVER THE GULF... THUNDERSTORMS ARE MORE PREVALENT AND AIRCRAFT MAY NEED TO BE REROUTED TO AVOID SOME CLUSTERS OF THUNDERSTORMS OVER COASTAL WATERS FROM PORT LAVACA TO TALLAHASSEE. CONDITIONS OVER THE HOUSTON FORECAST ARE EXPECTED TO IMPROVE SLIGHTLY THIS AFTERNOON AND TONIGHT WITH DIMINISHING PRECIPITATION AND CEILINGS LIFTING AS THE FIRST SHORT WAVE IN THE SOUTHWESTERLY FLOW ALOFT LIFTS OUT...BUT THIS WAVE WILL BE FOLLOWED TOMORROW BY A SECOND LOW AMPLITUDE SHORT WAVE WHICH WAS IN THE HE BIG BEND REGION THIS MORNING. ADDITIONALLY... MOST MODELS ARE ATTEMPTING TO DEVELOP A MORE DISTINCT TROUGH OR COASTAL LOW ON THE REMNANT BOUNDARY WHICH WILL BRING ANOTHER BOUT OF PRECIPITATION SUNDAY... MOST LIKELY WITH MORE WIDESPREAD THUNDERSTORM COVERAGE. CONSEQUENTLY... WILL HAVE ON AND OFF MVFR AND IFR CONDITIONS AGAIN AFTER 09Z SUNDAY AND WILL HAVE THE POTENTIAL FOR AIRFIELDS THROUGHOUT THE REGION TO BE IMPACTED BY PERIODS OF IFR CONDITIONS IN SHOWERS AND THUNDERSTORMS THROUGHOUT THE DAY. 38 MARINE... THE BOUNDARY ALONG THE COAST MENTIONED IN THE AVIATION SECTION ABOVE HAS PROVIDED A FOCUS FOR THE GENERATION OF NUMEROUS SHOWERS AND THUNDERSTORMS OVER THE COASTAL WATERS. THE DISTURBED WEATHER WILL DIMINISH TONIGHT BUT IS EXPECTED TO REDEVELOP SUNDAY MORNING AS A COASTAL TROUGH BECOMES BETTER DEFINED AND ANOTHER SHORT WAVE MOVES INTO SOUTHEAST TEXAS AND THE ADJACENT COASTAL WATERS. WINDS WILL CONTINUE TO BE HIGHLY VARIABLE REST OF TODAY... MAINLY EAST NORTH OF THE BOUNDARY AND SOUTHEAST TO SOUTH ON THE SOUTH SIDE... FURTHER COMPLICATED BY DOWNDRAFTS FROM THUNDERSTORMS. THE LIGHT SURFACE FLOW WILL CONTINUE TO BE VARIABLE ON MONDAY WITH WINDS BECOMING NORTHEAST UNDER THE INFLUENCE OF HIGH PRESSURE OVER THE SOUTHEASTERN U.S. AND VERY WEAK GRADIENTS OVER THE GULF. A WEAK FRONT WILL MOVE INTO THE REGION TUESDAY REINFORCING THE NORTHEAST FLOW... FOLLOWED BY DRIER AIR AND WINDS VEERING TO EAST ON WEDNESDAY AND RETURNING TO A LIGHT ONSHORE FLOW LATE IN THE WEEK. 38 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX 256 PM CDT SAT SEP 9 2006 .DISCUSSION... SHRA/TSRA CLUSTER ASSOCIATED WITH MCV MOVING ENE ACROSS UPPER TEXAS COAST AND COASTAL ZONES. SCATTERED CONVECTION DEVELOPING OVER FAR SOUTH TEXAS PICKED UP BY 18Z RUC AND WEAKEN THIS ACTIVITY BY EVENING. BELIEVE THIS MAY STILL STILL AFFECT COASTAL WATERS AND TO A LESSER EXTENT COASTAL ZONES. UPPER LEVEL FLOW NEARLY ZONAL ACROSS BOTH GFS AND NAM INDICATE COASTAL REGION WILL HAVE WEAK CONFLUENT LOW LEVEL FLOW THROUGH EARLY NEXT WEEK. CONFIDENCE IS NOT HIGH WITH THIS UPCOMING FORECAST PACKAGE. NAM DID NOT INITIALIZE WELL AND GFS HAS CHANGED THE SCENARIO FOR THE NEXT SEVERAL DAYS COMPARED TO PREVIOUS RUN. LATEST GFS RUN HAS BACKTRACKED ON MOISTURE/POPS NEXT SEVERAL DAYS LOWERING PWATS LATER THIS WEEKEND AND INTO NEXT WEEK DUE TO DRYING AT MID/UPPER LEVELS. NAM IS LESS AGGRESSIVE. GFS NOW BRINGING DRIER LOW LEVEL AIR 24 HOURS EARLIER WHICH WILL BE TUESDAY PUSHING WEAK FRONT TO THE NW GULF. MOISTURE INCREASE NOTED WEDNESDAY NIGHT OVER SW SECTIONS AND RETURN FLOW EVIDENT AREAWIDE THURSDAY. THURSDAY THROUGH SATURDAY AGAIN WILL HAVE HIGH MOISTURE LEVELS WITH PASSING IMPULSES IN THE UPPER LEVEL WSW FLOW. NOTE THAT WE WILL WAIT FOR MORE CONSISTENCY WITH LATER MODEL RUNS BEFORE WE LOWER OR TAKE OFF POPS FOR TUESDAY (AS WHAT GFS IS NOW INDICATING). 37 && AVIATION... THE REMAINS OF A WEAK FRONTAL BOUNDARY CONTINUE TO PROVIDE A CONFLUENT ZONE OVER THE COASTAL WATERS AND ARE PROVIDING A REGION OF OVERRUNNING WITH LIGHT EASTERLY FLOW IN THE LOWER 4KFT OR SO WITH SOUTH TO SOUTHWEST FLOW AT HIGHER LEVELS. THIS IS SETTING THE STAGE FOR PATCHY LIGHT RAIN OVER MUCH OF THE FORECAST AREA AS A SHORT WAVE MOVES THROUGH THE SOUTHWESTERLY FLOW ALOFT... AND IS PRODUCING BRIEF PERIODS OF MVFR AND IFR CONDITIONS MAINLY SOUTH OF A LINE FROM VCT TO IAH. OVER THE GULF... THUNDERSTORMS ARE MORE PREVALENT AND AIRCRAFT MAY NEED TO BE REROUTED TO AVOID SOME CLUSTERS OF THUNDERSTORMS OVER COASTAL WATERS FROM PORT LAVACA TO TALLAHASSEE. CONDITIONS OVER THE HOUSTON FORECAST ARE EXPECTED TO IMPROVE SLIGHTLY THIS AFTERNOON AND TONIGHT WITH DIMINISHING PRECIPITATION AND CEILINGS LIFTING AS THE FIRST SHORT WAVE IN THE SOUTHWESTERLY FLOW ALOFT LIFTS OUT...BUT THIS WAVE WILL BE FOLLOWED TOMORROW BY A SECOND LOW AMPLITUDE SHORT WAVE WHICH WAS IN THE HE BIG BEND REGION THIS MORNING. ADDITIONALLY... MOST MODELS ARE ATTEMPTING TO DEVELOP A MORE DISTINCT TROUGH OR COASTAL LOW ON THE REMNANT BOUNDARY WHICH WILL BRING ANOTHER BOUT OF PRECIPITATION SUNDAY... MOST LIKELY WITH MORE WIDESPREAD THUNDERSTORM COVERAGE. CONSEQUENTLY... WILL HAVE ON AND OFF MVFR AND IFR CONDITIONS AGAIN AFTER 09Z SUNDAY AND WILL HAVE THE POTENTIAL FOR AIRFIELDS THROUGHOUT THE REGION TO BE IMPACTED BY PERIODS OF IFR CONDITIONS IN SHOWERS AND THUNDERSTORMS THROUGHOUT THE DAY. 38 && .MARINE... THE BOUNDARY ALONG THE COAST MENTIONED IN THE AVIATION SECTION ABOVE HAS PROVIDED A FOCUS FOR THE GENERATION OF NUMEROUS SHOWERS AND THUNDERSTORMS OVER THE COASTAL WATERS. THE DISTURBED WEATHER WILL DIMINISH TONIGHT BUT IS EXPECTED TO REDEVELOP SUNDAY MORNING AS A COASTAL TROUGH BECOMES BETTER DEFINED AND ANOTHER SHORT WAVE MOVES INTO SOUTHEAST TEXAS AND THE ADJACENT COASTAL WATERS. WINDS WILL CONTINUE TO BE HIGHLY VARIABLE REST OF TODAY... MAINLY EAST NORTH OF THE BOUNDARY AND SOUTHEAST TO SOUTH ON THE SOUTH SIDE... FURTHER COMPLICATED BY DOWNDRAFTS FROM THUNDERSTORMS. THE LIGHT SURFACE FLOW WILL CONTINUE TO BE VARIABLE ON MONDAY WITH WINDS BECOMING NORTHEAST UNDER THE INFLUENCE OF HIGH PRESSURE OVER THE SOUTHEASTERN U.S. AND VERY WEAK GRADIENTS OVER THE GULF. A WEAK FRONT WILL MOVE INTO THE REGION TUESDAY REINFORCING THE NORTHEAST FLOW... FOLLOWED BY DRIER AIR AND WINDS VEERING TO EAST ON WEDNESDAY AND RETURNING TO A LIGHT ONSHORE FLOW LATE IN THE WEEK. 38 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 70 90 72 90 71 / 20 30 20 30 30 HOUSTON (IAH) 73 88 73 89 73 / 30 40 20 30 30 GALVESTON (GLS) 76 86 77 87 78 / 40 50 30 40 40 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LUBBOCK TX 102 PM CDT SAT SEP 9 2006 .UPDATE... SENT OUT A QUICK UPDATE TO LOWER HIGH TEMPERATURES SLIGHTLY ACROSS THE CENTRAL AND WESTERN ZONES WHERE LOW CLOUDS HAVE BEEN SLOW TO ERODE. ALSO RECONFIGURED POPS TO REFLECT BEST CHANCE ACROSS THE WESTERN AREAS NEAREST THE SURFACE TROUGH. BELIEVE SURFACE TROUGH MAY BE SUFFICIENT TO INITIATE ISOLATED THUNDERSTORMS LATER THIS AFTERNOON IN EASTERN NEW MEXICO...BEFORE TRANSLATING INTO THE WESTERN SOUTH PLAINS AND SOUTHWEST TEXAS PANHANDLE. 0-6 KM BULK SHEAR MAGNITUDE OF 30-35 KNTS IS BETTER THAN WE HAVE SEEN LATELY...ALTHOUGH THE LOW CLOUDS THIS MORNING MAY INHIBIT INSTABILITY FROM GROWING TOO FORMIDABLE AND UPPER LEVEL SUPPORT APPEARS MINIMAL. HOWEVER...15Z RUC DOES STILL INDICATE AROUND 800 J/KG OF SFC BASED CAPE NEAR THE NM BORDER BY THIS EVENING. THUS...IF STORMS CAN GET GOING...WOULD NOT BE SURPRISED TO SEE AN ISOLATE LOW END SEVERE STORM. HAVE UPDATED HWO TO MENTION THIS POSSIBILITY AS WELL AS INDICATE POSSIBLE ISOLATED SEVERE POTENTIAL SUNDAY. && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 23/20 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 340 PM EDT SAT SEP 9 2006 .SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/... DIURNAL CONVECTION IS TRYING TO FIRE IN THE FAR SOUTHWEST TO SOUTH ZONES OF THE CWA...BUT THE AIR MASS IS A TAD DRY...AND EACH LITTLE POP GETS EATEN UP BY THE DRY AIR SOON AFTER EACH ATTEMPTED CELL FORMS. OTHER CONVECTION IS SUCCESSFULLY FORMING IN CENTRAL KY WITH A SLOW DRIFT TO THE EAST...SO THIS WILL HAVE TO BE WATCHED. BUT I DID LOWER POPS FOR THE REST OF THIS AFTERNOON. WATER VAPOR LOOP SHOWS SOME MID LEVEL MOISTURE EDGING INTO THE CWA. THIS...ALONG WITH INTERMITTENT HIGH CLOUDS TONIGHT...WILL MAKE FOG CONDITIONS NOT AS IDEAL AS RECENT NIGHT. I STILL DO EXPECT FOG...BUT IT WILL LIKELY BE MORE PATCHY AND LESS DENSE COMPARED TO THIS MORNING. AS FOR TEMPS...I MAINLY USED MET GUIDANCE...AS THE MAV HAS BEEN CONSISTENTLY GOING TO LOW DURING THE LAST SEVERAL NIGHTS. BARELY ANY CHANGE WAS MADE TO TEMPS SUNDAY THROUGH SUNDAY NIGHT. THE GOING FORECAST HAD SLIGHT TO CHANCE POPS SPREADING INTO THE HIGHER TERRAIN SUNDAY NIGHT...DUE TO THE FORMATION OF AN INVERTED TROUGH WITH SOUTHEAST FLOW. LATEST MODEL RUNS ARE BRINGING THIS IN A BIT EARLIER...AND WITH SLIGHTLY MORE MOISTURE AND INSTABILITY...I ADDED SLIGHT CHANCE POPS ON THE APPALACHIAN EDGE OF THE CWA FOR SUNDAY AFTERNOON. && .AVIATION... I EXPECT FOG AGAIN TONIGHT...BUT WITH A LITTLE MORE MID LEVEL MOISTURE AND INTERMITTENT HIGH CLOUDS COMING IN...THE SET UP WILL NOT BE AS IDEAL AS RECENT NIGHTS. I STILL SEE MOST TAF SITES /ALL EXCEPT KBKW AND KCKB/ FINDING THEIR WAY DOWN TO LIFR...BUT FOR LESS OF A DURATION COMPARED TO LAST NIGHT/EARLY THIS MORNING. && .PREV DISCUSSION... /ISSUED 1042 AM EDT SAT SEP 9 2006/ SHORT TERM /REST OF TODAY/... FOG DID NOT LAST QUITE AS LONG THIS MORNING AS PREVIOUS MORNINGS...WITH VISIBLE SATELLITE SHOWING IT QUICKLY DISAPPEARING FOR ENTIRE CWA...LINGERING LONGEST IN THE TYGART RIVER VALLEY. OUTSIDE THE CWA...EASTERN KY HAS HAD A FEW WEAK CONVECTIVE CELLS THUS FAR THIS MORNING. ANALYSIS AND RUC INITIALIZATION SUGGEST AN AREA OF SLIGHTLY HIGHER DEWPOINTS /LWR 60S/...MARGINALLY NEGATIVE LIFTED INDEX...AND HIGHER THETA-E. I INCREASED AND EXPANDED AREA OF POPS FOR THIS AFTERNOON BASED ON THESE TRENDS...WITH APPROPRIATE ADJUSTMENTS TO SKY GRIDS. LOCAL WORK STATION ETA SUGGESTS A LITTLE BIT OF PRECIP NEAR THE TRI- STATE THIS AFTERNOON...WHILE LOCAL WRFNMM STILL DOES NOT. HOWEVER...IT SHOULD BE NOTED THAT NEITHER CAPTURED THE CURRENT CLUSTER OF SHOWERS IN EASTERN KY. CELLS ARE WEAKENING A BIT...BUT WHAT REMAINS OF THEM WILL REACH THE CWA BORDER BEGINNING AROUND 16Z. LONG TERM /SUNDAY THROUGH FRIDAY/... NO BIG CHANGES TO THIS PERIOD. SOME MIDLEVEL SUPPORT NEAR WEAK FRONT ACROSS THE NORTHERN COUNTIES ON SUNDAY...BUT MOISTURE JUST IS NOT THERE. MAIN ALTERATION WAS TO INTRODUCE SMALL EASTERLY UPSLOPE POPS SUNDAY NIGHT. ATLANTIC MOISTURE ON E/SE FLOW LOOKS TO HUG UP AGAINST THE MOUNTAINS SUNDAY NIGHT...NAM/GFS SEEM TO AGREE ON THIS. DO NOT FORESEE MUCH DEVELOPMENT GIVEN DRY AIRMASS CURRENTLY IN PLACE. LEFT THE FORECAST FOR MONDAY AND BEYOND PRETTY MUCH INTACT. ELECTED TO KEEP POPS FAIRLY SMALL...AS THERE IS STILL ONLY A SLOW MOISTURE INCREASE IN THE MODELS...AS WELL AS THE GFS SHOWING A SLOWER...STRONGER EASTWARD PROGRESSION WITH MAIN H500 SHORTWAVE DURING THE MIDWEEK PERIOD. THINK MAV 50ISH POPS ARE A BIT TOO HIGH AT THIS POINT FOR MONDAY. NO REAL CHANGES TO GRIDS BEYOND MONDAY NIGHT. MET AND LOCAL MOS TEMPERATURES HAVE BEEN VERY GOOD LATELY...SAW LITTLE REASON TO STRAY MUCH FROM THEM. PREV DISCUSSION... /ISSUED 140 AM EDT SAT SEP 9 2006/ AVIATION... OUR FCST CWA IN A NOWHERE LAND TODAY BETWEEN WEAK IMPULSES. I LIKE THE NAM12. WEAK VORT VICINITY/NORTH OF FRONT WILL TRIGGER SOME CONVECTION TO THE NORTH OF OUR CWA AND A WEAK VORT MAX DURING LATE AFTN WILL TRIGGER CONVECTION TO THE SOUTH OF OUR CWA FOR A FEW HOURS. THIS WILL MEAN JUST THE NORMAL CLIMO FOG FROM 03Z TO 15Z. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SHORT TERM...MDP AVIATION...MDP wv AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 1042 AM EDT SAT SEP 9 2006 .SHORT TERM /REST OF TODAY/... FOG DID NOT LAST QUITE AS LONG THIS MORNING AS PREVIOUS MORNINGS...WITH VISIBLE SATELLITE SHOWING IT QUICKLY DISAPPEARING FOR ENTIRE CWA...LINGERING LONGEST IN THE TYGART RIVER VALLEY. OUTSIDE THE CWA...EASTERN KY HAS HAD A FEW WEAK CONVECTIVE CELLS THUS FAR THIS MORNING. ANALYSIS AND RUC INITIALIZATION SUGGEST AN AREA OF SLIGHTLY HIGHER DEWPOINTS /LWR 60S/...MARGINALLY NEGATIVE LIFTED INDEX...AND HIGHER THETA-E. I INCREASED AND EXPANDED AREA OF POPS FOR THIS AFTERNOON BASED ON THESE TRENDS...WITH APPROPRIATE ADJUSTMENTS TO SKY GRIDS. LOCAL WORK STATION ETA SUGGESTS A LITTLE BIT OF PRECIP NEAR THE TRI- STATE THIS AFTERNOON...WHILE LOCAL WRFNMM STILL DOES NOT. HOWEVER...IT SHOULD BE NOTED THAT NEITHER CAPTURED THE CURRENT CLUSTER OF SHOWERS IN EASTERN KY. CELLS ARE WEAKENING A BIT...BUT WHAT REMAINS OF THEM WILL REACH THE CWA BORDER BEGINNING AROUND 16Z. && .PREV DISCUSSION... /ISSUED 342 AM EDT SAT SEP 9 2006/ SHORT TERM /THROUGH SATURDAY NIGHT/... WHILE FRONT WILL SLIP SOUTH FROM LAKES INTO THE AREA SATURDAY THERE IS NO CLEAR UPPER SUPPORT FOR MUCH IN THE WAY OF PCPN IN OUR CWA AND THE DIFFERENCE IN THE AIR MASSES NORTH AND SOUTH OF THE FRONT IS LITTLE. I LIKE THE NAM12 IDENTIFYING THE WEAK VORTS PASSING NORTH AND SOUTH OF OUR CWA LATER THIS AFTERNOON. THE SOUTHERN VORT WITH THE SUN PROMPTED ME TO GO WITH A SLIGHT CHC IN SW VIRGINIA. OTHERWISE HAVE NOT DONE ANYTHING WITH PCPN THROUGH SATURDAY NIGHT. NO BIG CHANGES TO TEMPS...JUST TWEAKS. LONG TERM /SUNDAY THROUGH FRIDAY/... NO BIG CHANGES TO THIS PERIOD. SOME MIDLEVEL SUPPORT NEAR WEAK FRONT ACROSS THE NORTHERN COUNTIES ON SUNDAY...BUT MOISTURE JUST IS NOT THERE. MAIN ALTERATION WAS TO INTRODUCE SMALL EASTERLY UPSLOPE POPS SUNDAY NIGHT. ATLANTIC MOISTURE ON E/SE FLOW LOOKS TO HUG UP AGAINST THE MOUNTAINS SUNDAY NIGHT...NAM/GFS SEEM TO AGREE ON THIS. DO NOT FORESEE MUCH DEVELOPMENT GIVEN DRY AIRMASS CURRENTLY IN PLACE. LEFT THE FORECAST FOR MONDAY AND BEYOND PRETTY MUCH INTACT. ELECTED TO KEEP POPS FAIRLY SMALL...AS THERE IS STILL ONLY A SLOW MOISTURE INCREASE IN THE MODELS...AS WELL AS THE GFS SHOWING A SLOWER...STRONGER EASTWARD PROGRESSION WITH MAIN H500 SHORTWAVE DURING THE MIDWEEK PERIOD. THINK MAV 50ISH POPS ARE A BIT TOO HIGH AT THIS POINT FOR MONDAY. NO REAL CHANGES TO GRIDS BEYOND MONDAY NIGHT. MET AND LOCAL MOS TEMPERATURES HAVE BEEN VERY GOOD LATELY...SAW LITTLE REASON TO STRAY MUCH FROM THEM. PREV DISCUSSION... /ISSUED 140 AM EDT SAT SEP 9 2006/ AVIATION... OUR FCST CWA IN A NOWHERE LAND TODAY BETWEEN WEAK IMPULSES. I LIKE THE NAM12. WEAK VORT VICINITY/NORTH OF FRONT WILL TRIGGER SOME CONVECTION TO THE NORTH OF OUR CWA AND A WEAK VORT MAX DURING LATE AFTN WILL TRIGGER CONVECTION TO THE SOUTH OF OUR CWA FOR A FEW HOURS. THIS WILL MEAN JUST THE NORMAL CLIMO FOG FROM 03Z TO 15Z. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SHORT TERM...MDP wv AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSONVILLE FL 303 AM EDT SUN SEP 10 2006 .SHORT TERM...MSAS ANALYSIS CONTINUES TO SHOW HIGH PRESSURE CENTERED OVER THE CAROLINAS WITH A TIGHTENING GRADIENT TO THE EAST OF THE HIGH FROM THE INTERACTION WITH DISTANT FLORENCE. THIS LEAVES OUR AREA IN A MUCH LIGHTER NORTHEAST FLOW REGIME. THERE ARE SOME SHOWERS OVER THE COASTAL WATERS AT THIS HOUR...BUT THEY SEEM TO BE THE MORE TYPICAL NOCTURNAL TYPE AND NOT AS MUCH STREAMLINE CONVERGENCE ALONG THE COAST HAS RESULTED IN LESS LAND BASED CONVECTION COMPARED TO LAST NIGHT. TO THE WEST OF THE AREA...SHOWERS CONTINUE TO DEVELOP AIDED BY A DECENT ISENTROPIC UPGLIDE PROFILE INDICATED BY THE RUC. THE RUC KEEPS THIS AREA TO THE WEST OF US THROUGH DAYBREAK...BUT WOULD NOT BE SURPRISED TO SEE A FEW SPRINKLES EMANATING FROM THICKENING MID A HIGH LEVEL DECK. FOR THE REMAINDER OF TODAY...WAS HOPING FOR BETTER MODEL AGREEMENT FOR THIS RUN BUT THIS IS NOT THE CASE. ALTHOUGH THE MODELS ARE TRENDING TOWARD EACH OTHER...I AM STILL LEFT WITH A 30% POP DISCREPANCY WITH THE GFS BEING THE WETTER SOLUTION. NOT A WHOLE LOT TO HANG MY HAT ON WRT MODEL INITIALIZATION BUT HAVE NOTED A BETTER REPRESENTATION OF FLORENCE BY THE NAM...BOTH IN SIZE AND INTENSITY OF THE STORM. THIS WOULD LEAD ONE TO BELIEVE THAT INFLUX OF DRY AIR IN EASTERLY FLOW UP TO 5K FEET WOULD INFILTRATE THE EASTERN SECTIONS A LITTLE MORE THAN WHAT THE GFS INDICATES. PLAN FOR TODAY IS TO GO WITH HIGHEST POPS FOR THE WESTERN ZONES...KEEPING LOW END LIKELY WHERE MODELS HAVE THE BEST AGREEMENT AND THEN SHOW A SHARP GRADIENT TOWARD THE EAST WHERE THE BEACHES WILL ONLY SEE LOW END SCATTERED RAIN CHANCES. THERMODYNAMIC PROFILE IS VERY SIMILAR TO YESTERDAY...SO MAY SEE SOME STRONG STORMS WITH PROLIFIC LIGHTNING BUT THAT SHOULD BE THE EXTENT OF IT. FOR MONDAY...MODELS ACTUALLY COME INTO A BIT BETTER AGREEMENT WITH THE STRENGTHENING OF MID ATLANTIC SURFACE RIDGE WITH SOME WEDGING INDICTED DOWN THE EAST COAST. THIS SHOULD PROVIDE MORE DRYING AND TEND TO SHUNT THE BULK OF THE PRECIP TO THE WEST. NAM A LITTLE STRONGER WITH THE DEVELOPMENT OF GULF COAST LOW WHICH ACTS TO DRAW MOISTURE CLOSER TO IT. FEEL THIS MAY BE A BIT OVERDONE AND WILL LEAN TOWARD THE MAV POPS WHICH ARE IN THE MID RANGE SCATTERED CATEGORY. PRETTY MUCH THE SAME SCENARIO IN STORE FOR TUE WITH RIDGE TO THE NORTHEAST AND DEEP MOISTURE TO THE WEST CREATING QUITE A POP GRADIENT ACROSS THE CWA. STILL FEEL THE BEST RAIN CHANCES WILL BE WEST OF THE AREA AND WILL KEEP GRIDS IN THE SCATTERED CATEGORY FOR NOW. WITH MORE STABLE SURFACE LAYER BUILDING IN THROUGH EARLY NEXT WEEK...MAY BE ABLE TO GET BY WITH JUST ISOLATED THUNDER. WILL KEEP SCT FOR NOW TO ACCOUNT FOR ELEVATED CONVECTION POSSIBILITY AND LET LATER SHIFTS REFINE IF NECESSARY. .LONG TERM...RIDGE BEGINS TO BREAK DOWN BY TUE NIGHT AS A DEEP LAYER PRE FALL TROUGH MOVES THROUGH THE MID MISSISSIPPI VALLEY. ENERGY AROUND THE BASE OF THE TROUGH ACTUALLY DEVELOPS A SURFACE LOW PER THE GFS WED MORNING. WITH RIGHT REAR QUAD OF UPPER JET ENTERING THE PICTURE WED EVENING...WILL NEED TO MONITOR FOR POSSIBLE SEVERE WEATHER SHOULD EVENT UNFOLD AS GFS DEPICTS. && .MARINE...AN ENE FLOW PREVAILS OVER THE MARINE AREA AROUND 8-12 KT PER BUOYS. SEAS HAVE COME UP SINCE YESTERDAY WITH WAVE PERIODS INCREASING INDICATING THE ARRIVAL OF LONGER PERIOD SWELL FROM FLORENCE. SMALL BUT DETECTABLE SWELL IN THE 14-16 SECOND RANGE IS NOTED FROM ALL THE LOCAL BUOYS BUT THE PEAK OF THE WAVE ENERGY IS IN THE FREQUENCY OF 11-12 SECONDS. WAVEWATCH AND NAH WAVE MODELS HAVE TOO LITTLE LONG PERIOD SWELL TO START OFF THE FORECAST BUT CATCH UP LATER TODAY WITH PERIODS OF 13-14 SECONDS. AT THIS TIME THE BEGINNING OF SMALL CRAFT ADVISORY HEADLINES DON'T LOOK TO START UNTIL LATE MONDAY OR MONDAY NIGHT. EXERCISE CAUTION CONDS FOR OFFSHORE WATERS LOOKS PROBABLE BY TONIGHT. MAY ISSUE A MARINE WEATHER STATEMENT FOR THE UPCOMING SWELL AND ADVISORY EVENT WITH A MENTION OF DANGEROUS BREAKERS NEAR INLETS. WINDS GRADUALLY INCREASE TO AROUND 15-20 KT ON MONDAY PRES GRADIENT TIGHTENS BETWEEN FLORENCE AND THE RIDGE OF HIGH PRES TO OUR N. WINDS RELAX GRADUALLY BY LATE TUE AND VEER ON WED AHEAD OF FRONT AND LOW PRES SYSTEM DEVELOPING OVER THE SE CONUS. && .AVIATION...WIDESPREAD MID CLOUDS MOVING THROUGH THE FORECAST AREA WITH ISOLD SHOWER ACTIVITY AFFECTING N ST JOHNS AND S DUVAL COUNTIES. ANTICIPATE PERIODS OF LOW CLOUDS AROUND 2-4 KFT AT COASTAL SITES THIS MORNING WITH TEMPO SHRA AND VCSH. INSERTED TEMPO FOR GNV FOR SHRA/TSRA MAINLY AFTER 14Z. BEST AREAS FOR TEMPO FOG AND IFR CEILINGS FOR THIS AM AGAIN APPEARS TO BE LOCATED FROM INLAND NE FL COUNTIES. && .PRELIMINARY POINT TEMPS/POPS... AMG 87 68 86 68 / 30 30 30 5 SSI 85 71 84 71 / 30 30 20 5 JAX 85 72 85 72 / 40 30 30 5 SGJ 85 73 84 73 / 40 30 30 10 GNV 86 70 86 69 / 60 40 40 20 OCF 88 70 87 70 / 60 40 40 20 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. MARINE...NONE. && $$ PUBLIC...DEESE MARINE/FIRE WX/AVIATION...SHASHY fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 350 AM CDT SUN SEP 10 2006 .DISCUSSION... CURRENT FORECAST APPEARS TO BE IN GOOD SHAPE WITH ONLY MINOR ADJUSTMENTS NEEDED TO POPS. THE NAM/RUC CONTINUE TO HAVE THE CURRENT WX MODELED WELL AND THE GFS STILL APPEARS TO PUSH THE HEAVIER RAINS TOO FAR NORTH TODAY AND TONIGHT. NUMEROUS INGREDIENTS ARE IN PLACE FOR SIGNIFICANT RAINFALL OVER MOST OF THE CWA THROUGH MONDAY...INCLUDING PWAT/S AOA 1.5 INCHES...STRONG PERSISTENT ISENTROPIC LIFT AND MOISTURE TRANSPORT. THIS ALSO HAS THE LOOK OF A STRONG WINTER SYSTEM COMPLETE WITH WELL DEFINED TROWAL AND DEFORMATION AXIS. MUCH OF THE FORECAST AREA SHOULD RECEIVE AN ADDITIONAL 2 TO 4 INCHES OF RAIN THROUGH MONDAY ESPECIALLY ALONG AND SOUTH OF HIGHWAY 20...WITH ISOLATED 4 TO 6 INCH TOTALS A GOOD BET. THE NAM IS NAILING SOUTHERN IOWA IN PARTICULAR TODAY AND TONIGHT WITH STRONG ADIABATIC ISENTROPIC OMEGA. RAINFALL RATES WILL BE SUCH THAT FLASH FLOODING SHOULD NOT BE MUCH OF A CONCERN. SOME MINOR URBAN STREET FLOODING IS EXPECTED. THE MAIN CONCERN IS THE RESPONSE OF AREA RIVERS...AND IN PARTICULAR THE FASTER RESPONDING CREEKS AND RIVERS LATER TODAY THROUGH THE EARLY PART OF THE WEEK. A FLOOD WATCH MAY BE IN THE OFFING LATER TODAY AND WILL HIT HEAVY RAIN POTENTIAL HARD IN GRIDS/ZONES/HWO. THE HEAVIER RAINS SHOULD SHIFT TO THE EAST BY DAYBREAK TUESDAY FOLLOWED BY A NARROW SFC HI PRES RIDGE. THE WARMING TREND FOR LATER IN THE WEEK STILL LOOKS ON TRACK WITH SMALL POPS ON FRI/SAT. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ KINNEY ia AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 400 AM EDT SUN SEP 10 2006 .DISCUSSION... THE MAIN CONCERNS WITH THIS FORECAST PACKAGE ARE THE OVERNIGHT LOWS TONIGHT AND CHANCE OF SHOWERS MONDAY NIGHT. WATER VAPOR IMAGERY AND RUC SHOWING A NEAR ZONAL FLOW ACROSS THE SOUTH HALF OF CONUS...A LONGWAVE TROUGH OVER EASTERN CANADA...A RIDGE OVER CENTRAL CANADA...AND ANOTHER LONGWAVE TROUGH OVER GULF OF ALASKA. A WEAK SHORTWAVE TRAPPED IN THE NORTHERLY FLOW ACROSS NORTH AMERICA IS OVER SOUTH CENTRAL CANADA STRETCHING INTO NORTHERN MINNESOTA. ANOTHER SHORTWAVE IS OVER EASTERN ONTARIO WORKING ITS WAY THROUGH THE BASE OF THE EASTERN CANADIAN TROUGH. SURFACE ANALYSIS INSIST THAT A STATIONARY FRONT STRETCHES FROM KWDC THROUGH THE SOUTHERN OHIO RIVER VALLEY TO A LOW OVER NORTH CENTRAL KANSAS. A LARGE DOME OF HIGH PRESSURE BLANKETS ONTARIO...SOUTHERN QUEBEC AND THE GREAT LAKES REGION. A FRONTAL SYSTEM IS DEVELOP OVER THE WESTERN CANADIAN PRAIRIE AND OVER THE NORTHERN HIGH PLAINS OF CONUS. A FEW THUNDERSTORMS AND SHOWERS HAVE BEEN OCCURRING OVERNIGHT IN ASSOCIATION WITH THE LOW OVER KANSAS. THE LONGWAVE TROUGH WILL MOVE VERY LITTLE TODAY AS WILL THE RIDGE OVER CENTRAL CANADA. THE SURFACE RIDGE OVER THE FORECAST AREA WILL REMAIN DOMINATE OVER THE REGION. PRECIPITABLE WATER WILL BE AROUND .5 INCH ACROSS THE FORECAST AREA TODAY. FORECAST SOUNDINGS INDICATE A STRONG CAPPING INVERSION AROUND 850MB OVER THE FORECAST AREA. THE 925MB TEMPERATURES ARE PROGGED TO BE CLOSE TO THE SAME AS YESTERDAY'S... EXCEPT A LITTLE WARMER OVER THE EASTERN U.P. EVEN THE TRAJECTORY PROGS INDICATE VERY LITTLE CHANCE IN AIR MASS. HOWEVER...TODAY THE FORECAST SOUNDINGS INDICATING A LITTLE LESS LOW LEVEL CLOUDS. THUS MAY EXPECT A LITTLE WARMER TEMPERATURES DUE TO THE ADDITIONAL SUN. PLAN TO GO WITH JUST A LITTLE HIGHER TEMPERAURES THAN YESTERDAYS WHICH IS WHAT GUIDANCE SUGGEST ALSO. THE MID LEVEL RIDGE WILL SLIDE INTO WESTERN ONTARIO TONIGHT WHILE THE SURFACE RIDGE PUSHES INTO SOUTHWEST QUEBEC. A SHORTWAVE WILL RUN INTO THE RIDGE AND START TO BREAK IT DOWN. THE SURFACE LOW OVER KANSAS WILL TRAVEL INTO NORTHERN MISSOURI...PULLING A PORTION OF THE FRONTAL SYSTEM NORTHERN INTO CENTRAL ILLINOIS AND CENTRAL INDIANA. THE ACCOMPANYING LOW LEVEL MOISTURE OVER RUNNING THE FRONT WILL SHIFT INTO SOUTHERN WISCONSIN AND INTO LOWER MICHIGAN...STILL KEEP THE FORECAST AREA DRY. A 70 KNOT UPPER LEVEL JET MAX WILL SLIDE ACROSS NORTHERN LOWER MICHIGAN TONIGHT. KEEPING THE FORECAST AREA UNDER THE LEFT ENTRANCE REGION OF THE JET MAX. THUS WITH THE DRY AIR ENTRENCHED OVER THE FORECAST AREA PLAN TO KEEP THE FORECAST AREA DRY. FORECAST SOUNDINGS CONTINUE TO SHOW A DRY AIR MASS OVER THE FORECAST AREA FOR TONIGHT EXCEPT ALONG THE LAKE MICHIGAN SHORELINE. GFS SOUNDING DRAWING CLOUDS INTO THE FORECAST AREA AROUND 500MB AND ABOVE. THIS MAY REDUCE RADIATIONAL COOLING. WITH AN ABUNDANCE OF SUN FOR TODAY AND AN INCREASE CLOUD COVER TONIGHT...WILL KEEP TEMPERATURES A LITTLE WARMER FOR TONIGHT. 925MB TEMPERATURES ARE EXPECTED TO BE 1 TO 2 DEGREE C WARMER OVER THE WEST TONIGHT AND ABOUT THE SAME AS THIS MORNING OVER THE EAST. GUIDANCE SUGGESTING THE SAME. THE MID LEVEL RIDGE WILL SHIFT INTO EASTERN ONTARIO AND BEGIN TO FLATTEN OUT ON MONDAY. MEANWHILE...THE SHORTWAVE RUNNING INTO THE RIDGE WILL DEVELOP INTO A CLOSED LOW WILL DIP SOUTHEAST EAST BELOW THE RIDGE AND MOVE INTO CENTRAL MINNESOTA. OTHER WEAK SHORTWAVES ROTATING AROUND THE CLOSED LOW WILL SWEEP INTO THE FORECAST AREA. THE MISSOURI SURFACE LOW WILL BE FORCED INTO CENTRAL ILLINOIS. THE SURFACE RIDGE WILL CONTINUE TO STRETCH FROM EAST CENTRAL ONTARIO ACROSS THE FORECAST AREA THEN SOUTHWEST INTO EASTERN NEBRASKA...THE HIGH PLAINS FRONTAL SYSTEM WILL MEANDER INTO CENTRAL DAKOTAS. LOW LEVEL MOISTURE WILL CONTINUE TO BE VERY LIMITED AS THE ILLINOIS LOW WILL TEND TO KEEP THE MOISTURE CLOSE TO IT. GFS SUGGEST THAT THERE MAY BE ENOUGH MOISTURE OVER THE SOUTH END OF MENOMINEE COUNTY TO PRODUCE SOME RAIN...HOWEVER...ECMWF/NAM/GLOBAL MODELS CONTINUE TO SHOW IT WILL BE TOO DRY. THIS IS BECAUSE GFS IS MOST AGRESSIVE WITH THE DEVELOPMENT OF THE SURFACE LOW AND MOVING IT INTO LOWER MICHIGAN. AS HPC POINTED OUT IN THE LATEST DISCUSSION...A PREFERRED NAM/GFS BLEND WOULD BE PREFERRED SOLUTION WHICH WOULD KEEP PRECIPITATION MAINLY TO THE SOUTH OF THE U.P. ON MONDAY. THIS IS ALSO SEEMS PREFERED BY THE ENSEMBLE SOLUTION. THE MID LEVEL LOW WILL SHIFT INTO NORTHEAST IOWA MONDAY NIGHT. NAM CONTINUES TO KEEP THE LOW A LITTLE FURTHER SOUTH OF GFS. NAM ALSO IS A LITTLE SOUTH OF AND LESS AGGRESSIVE WITH THE SURFACE POSITION OF ASSOCIATED LOW. STILL LOOKING TO FAVOR A BLENDED SOLUTION SO WILL BE CUTTING BACK A LITTLE ON PRECIPITATION POTENTIAL. THE NAM CONTINUES TO BE A LITTLE SOUTH OF GFS SOLUTION FOR POSITIONS OF THE MID LOW ON TUESDAY...AS WELL AS BE QUITE BIT SOUTH AND LESS AGREESIVE WITH THE SURFACE LOW. THE POSITION OF THIS LOW WILL BE INSTUMENTAL IN THE DEVELOP OF PRECIPITATION OVER THE FORECAST AREA. GFS KEEP SHOWERS GOING OVER THE EAST PART OF THE FORECAST AREA ON TUESDAY WHILE NAM KEEPS IT SOUTH OF THE FORECAST AREA. WILL CONTINUE WILL A SLIGHT CUT BACK ON CHANCE OF SHOWERS. TWO WEAK SHORTWAVES WILL SWEEP THROUGH UPPER MICHIGAN TUESDAY NIGHT AS THE MID LEVEL LOW MOVES OVER THE KCHI AREA. THE SURFACE LOW WILL EDGE INTO SOUTHERN LOWER MICHIGAN. A WARM FRONT LEADING THE LOW WILL MOVE INTO THE LOWER GREAT LAKES AS A TRAILING COLD FRONT SWEEPS INTO INDIANA. A WEAK RIDGE WILL MOVE OVER THE FORECAST AREA. DRY AIR ACCOMPANYING THIS SYSTEM WILL CAUSE THE CHANCE OF RAIN TO DIMINISH OVER THE WEST END OF THE U.P. DRY AIR WILL BRING MORE SETTLE WEATHER TO THE AREA ON WEDNESDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... FREEZE WARNING THIS MORNING FOR MIZ002>005-009>011-084. FROST WARNING THIS MORNING FOR MIZ001-003-006-007-012>014-085. && $$ DLG mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 257 AM CDT SUN SEP 10 2006 .DISCUSSION... TIMING THE ENDING OF PCPN IS THE PROBLEM IN THE SHORT TERM. PCPN SHOULD END SOMETIME MONDAY AND THEN ATTENTION WILL TURN TOWARD TEMPS. 850 MB PLOT FROM LAST EVENING SHOWED THAT DEWPOINTS OF 10C OR MORE HAD WORKED THEIR WAY NORTH ACROSS KS AND INTO SWRN NE. 700 MB DEWPOINTS HAD INCREASED TO LITTLE ABOVE 0C...AND A 5 WAS NOTED AT DDC. A COMBINATION OF WATER VAPOR IMAGERY...PROFILER AND RUC DATA SUGGESTED CENTER OF MID TROPOSPHERIC LOW WAS WEST OF OFK. PROFILERS ALSO SHOWED THAT A DECENT LOW LEVEL JET HAD DEVELOPED... FAIRBURY HAD 850 MB WINDS OF 35-45 KTS THE PAST FEW HOURS. THIS HELPED INCREASE EMBEDDED CONVECTION OVER OUR SRN ZONES. AT THE SURFACE...A NEARLY STATIONARY FNT STRETCHED FM CNTRL MO ACROSS CNTRL KS AND THEN BACK INTO CO. A LOW WAS ALONG THE FNT IN WRN KS AND A TROF EXTENDED FM THE LOW INTO CNTRL NE. SYSTEM WILL MOVE EWD TODAY...WITH SURFACE TROUGH LIKELY BEING THE WRN EXTENT OF MAIN PCPN AREA. HIGHS TODAY SHOULD BE HELD DOWN BY CLOUDS AND PCPN...SO LEFT THINGS CLOSE TO PREVIOUS FORECAST (IN THE MID 60S TO AROUND 70). 00Z RUN OF THE GFS WAS STILL PROBABLY A LITTLE TOO FAST IN MOVING SYSTEM OUT AND ENDING PCPN. USED A BLEND OF THE NAM...GFS AND THE UKMET FOR PCPN TIMING. EXPECT RAIN TO END IN THE FAR WRN ZONES TNGT AND INTRODUCED SOME PATCHY FOG LATE WHERE SKIED COULD CLEAR. OTHERWISE...KEPT SOME SLIGHT CHANCE GOING MAINLY IN WRN IA INTO MONDAY AFTERNOON. TEMPS SHOULD REMAIN COOL...WITH HIGHS IN THE UPPER 60S AND LOWER 70S. SURFACE RIDGE AXIS BUILDS OVER THE AREA FOR MONDAY NIGHT. WITH LIGHT WINDS AND WET GROUND...EXPECT FOG TO FORM AND THE FOG COULD BE DENSE. OTHERWISE KEPT THE TREND OF DRY WEATHER AND MODERATING TEMPS FOR THE MID PART OF THE WEEK. MODELS DIG A TROUGH OVER WRN CANADA AND THE WRN U.S. LATER IN THE WEEK. 500 MB FLOW SHOULD BE FAIRLY ZONAL AT 12Z THU...BUT TURNS TO SOUTH OR SOUTHWEST BY 00Z SAT. LEFT HIGHS MAINLY FM AROUND 80 TO THE MID 80S FROM WED THROUGH SAT. ALSO LEFT LOW POPS IN FOR THE WEEKEND. IT HAS ALREADY RAINED AT LEAST ONE DAY IN 5 OF THE LAST 6 WEEKENDS AT OMAHA. NEXT WEEKEND WOULD BE 6 OF 7. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ MILLER ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ABERDEEN SD 402 AM CDT SUN SEP 10 2006 .SHORT TERM...TODAY THROUGH TUESDAY NIGHT SKY COVER CONTINUES TO BE THE MAIN ISSUE IN THE SHORT TERM...AND NOW PRECIP CHANCES FOR MONDAY AFTERNOON AND EVENING AS A SFC FRONT AND UPPER WAVE MOVE INTO THE AREA. STRATUS DECK HOLDING THICK SOUTH OF A MBG-ABR-VVV LINE WITH CEILINGS FROM 500-2500 FT ALL THE WAY TO THE SD/NEB BORDER. NORTH OF THIS LINE A SCT-BKN025-040 CLOUD DECK EXISTS WITH A SHARP CUTOFF TO CLEAR SKIES JUST NORTH OF THE ND/SD BORDER. THIS HAS MATCHED UP WELL WITH MODEL 925MB RH FIELDS THROUGHOUT THE EARLY MORNING HOURS. RUC/HI RES NAM WOULD SUGGEST A GRADUAL BREAKUP OF CLOUDS ACROSS CENTRAL SD THIS MORNING...BUT STRATUS BEING MORE STINGY ACROSS EASTERN SD AND EXTREME WEST CENTRAL MN. HAVE LEFT SKY COVER GRIDS TO REFLECT A MOSTLY CLOUDY TO CLOUDY WORDING FOR THIS AFTERNOON ACROSS THE I-29 CORRIDOR...ESPECIALLY SOUTH OF SISSETON. HAVE ALSO ADDED MORNING FOG FROM PIERRE SOUTH AS VIS HAS BEEN COMING DOWN ALL MORNING AND IS NOW BETWEEN 1-2SM. OVERNIGHT STRATUS MAKES A RETURN TO THE NORTH AND WEST TO COVER MOST OF EASTERN SD AND WEST CENTRAL MINNESOTA AS 925MB FLOW PERSISTS FROM THE EAST/SOUTHEAST. THERE WAS SOME QUESTION AS TO JUST HOW FAR NORTH STRATUS WOULD ADVANCE SUNDAY NIGHT. MODELS SHOW A PLUME OF HIGH RH HEADING NORTH UP THE RED RIVER VALLEY SO HAVE CLOUDY SKY GRIDS ACROSS THE ENTIRE EASTERN PORTION OF THE CWA. STRATUS EARLY THIS MORNING STOPS AT THE ND/SD BORDER BUT 925MB WINDS ARE MORE ESE. MODELS SHOW WINDS TURNING MORE SE/SSE WHICH WOULD SUGGEST STRATUS COULD ADVANCE FARTHER NORTH SUNDAY NIGHT THAN WHAT HAPPENED THIS MORNING. THINK STRATUS WILL HAVE A TOUGH TIME DEPARTING ON MONDAY ALSO AND KEPT SKY COVER RATHER HIGH ACROSS THE EASTERN COUNTIES INTO THE EARLY AFTERNOON. ATTENTION THEN TURNS TO SYSTEM MOVING INTO THE CENTRAL DAKOTAS MONDAY AFTERNOON. SFC TROUGH CURRENTLY LOCATED ACROSS CENTRAL MT IS FORECAST TO MOVE INTO THE WESTERN DAKOTAS BY MONDAY AFTERNOON. NAM IS A BIT MORE AGGRESSIVE WITH THE FRONT AND BRINGS IT FARTHER EAST INTO CENTRAL DAKOTAS WHEREAS GFS LOOKS LIKE IT WANTS TO WASH IT OUT MONDAY EVENING. MINIMAL INSTABILITY DEVELOPS ACROSS WESTERN DAKOTAS MONDAY AFTERNOON AND A FEW MODELS ALSO SHOWING SMALL QPF ALONG FRONT. HAVE INTRODUCED SLIGHT CHANCE POPS FOR THE FAR NORTHWESTERN CWA FOR MONDAY AFTERNOON. .LONG TERM...WEDNESDAY THROUGH SUNDAY MEDIUM RANGE IN FAIR AGREEMENT TODAY. WILL END UP WITH A BLEND OF THE GFS AND THE HPC GUIDANCE. THE EXTENDED PERIOD OPENS WITH H5 UPPER RIDGE FOLDING OVER THE TOP OF THIS AREA AS A PACIFIC STORM SYSTEM MOVES ONSHORE NEAR THE BRITISH COLUMBIA COAST. BY THURSDAY MORNING THE UPPER FLOW IN THIS AREA IS BECOMING SOUTHWEST AND COOLER PACIFIC AIR IS FORCING ITS WAY IN FROM THE NORTH. THERE IS AN OLD BAROCLINIC ZONE LYING ALONG THE BORDER OF NORTH AND SOUTH DAKOTA. TRIMMED BACK THE ONSET OF PRECIPITATION AS THIS MODEL RUN IS A LITTLE SLOWER PUSHING INTO THE AREA. FROM THAT POINT ON THE UPPER FLOW BECOMES INCREASINGLY SOUTHWEST AS THE PACIFIC LOW DIGS ALONG THE WEST COAST OF THE UNITED STATES. AFTER THIS IT WILL INVOLVE TIMING OF THE ENERGY THAT ROUNDS THE TROUGH BASE AS MOVES OUT ON THE PLAINS. EXPECT THE TIMING OF PRECIPITATION WILL BE ABLE TO BE SHAVED BACK CONSIDERABLY AS EACH WAVE BECOMES MORE CLEARLY DEFINED. AT THIS POINT IT SEEMS THE BEST WAY TO HANDLE THE PERIOD IS LONG DURATION LOW PROBABILITY POPS. TEMPERATURES WERE IN GOOD SHAPE. FEW CHANGES WERE MADE. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ TT/SK sd AREA FORECAST DISCUSSION...UPDATE NATIONAL WEATHER SERVICE MARQUETTE MI 1045 AM EDT SUN SEP 10 2006 .UPDATE... NO SIGNIFICANT CHANGES PLANNED TO ONGOING FCST. AFTER A FROSTY START ACROSS MUCH OF THE INTERIOR THIS MORNING...A FEW LOCALES IN THE INTERIOR WEST BOTTOMED OUT IN THE LOWER 20S...TEMPERATURES HAVE BEEN CLIMBING UNDER ABUNDANT SUNSHINE. ONLY EXCEPTION IS ACROSS PORTIONS OF THE KEWEENAW AND ALONG THE NORTHERN LAKE MI SHORELINE WHERE SOME STRATOCU DEVELOPED OVER THE WATER AND IS AFFECTING THOSE LOCATIONS. WITH SFC RIDGE STILL LOCATED JUST NORTHEAST OF LAKE SUPERIOR OVER ONTARIO AND LITTLE IN THE WAY OF ADVECTIVE AFFECTS...AFTERNOON TEMPS SHOULD TOP OUT IN THE 60 TO 65 DEGREE RANGE TODAY. SAT IMAGERY SHOWING UPPER LOW OVER SPINNING OVER THE CENTRAL PLAINS WITH LEADING EDGE OF CLOUD SHIELD MAKING SOME PROGRESS INTO NORTHERN WI. EXPECT THE DRIER AIR OVER THE REGION TO HOLD MOST OF THE CLOUDS AT BAY BUT MAY BEGIN TO SEE SOME OF THEM SPILL INTO WI BORDERING COUNTIES BY LATER THIS AFTERNOON. WILL UPDATE FORECAST TO REMOVE MORNING HEADLINES AND MAKE MINOR ADJUSTMENTS TO CLOUD COVER. .PREVIOUS DISCUSSION ISSUED AT 400 AM EDT SUN SEP 10 2006... THE MAIN CONCERNS WITH THIS FORECAST PACKAGE ARE THE OVERNIGHT LOWS TONIGHT AND CHANCE OF SHOWERS MONDAY NIGHT. WATER VAPOR IMAGERY AND RUC SHOWING A NEAR ZONAL FLOW ACROSS THE SOUTH HALF OF CONUS...A LONGWAVE TROUGH OVER EASTERN CANADA...A RIDGE OVER CENTRAL CANADA...AND ANOTHER LONGWAVE TROUGH OVER GULF OF ALASKA. A WEAK SHORTWAVE TRAPPED IN THE NORTHERLY FLOW ACROSS NORTH AMERICA IS OVER SOUTH CENTRAL CANADA STRETCHING INTO NORTHERN MINNESOTA. ANOTHER SHORTWAVE IS OVER EASTERN ONTARIO WORKING ITS WAY THROUGH THE BASE OF THE EASTERN CANADIAN TROUGH. SURFACE ANALYSIS INSIST THAT A STATIONARY FRONT STRETCHES FROM KWDC THROUGH THE SOUTHERN OHIO RIVER VALLEY TO A LOW OVER NORTH CENTRAL KANSAS. A LARGE DOME OF HIGH PRESSURE BLANKETS ONTARIO...SOUTHERN QUEBEC AND THE GREAT LAKES REGION. A FRONTAL SYSTEM IS DEVELOP OVER THE WESTERN CANADIAN PRAIRIE AND OVER THE NORTHERN HIGH PLAINS OF CONUS. A FEW THUNDERSTORMS AND SHOWERS HAVE BEEN OCCURRING OVERNIGHT IN ASSOCIATION WITH THE LOW OVER KANSAS. THE LONGWAVE TROUGH WILL MOVE VERY LITTLE TODAY AS WILL THE RIDGE OVER CENTRAL CANADA. THE SURFACE RIDGE OVER THE FORECAST AREA WILL REMAIN DOMINATE OVER THE REGION. PRECIPITABLE WATER WILL BE AROUND .5 INCH ACROSS THE FORECAST AREA TODAY. FORECAST SOUNDINGS INDICATE A STRONG CAPPING INVERSION AROUND 850MB OVER THE FORECAST AREA. THE 925MB TEMPERATURES ARE PROGGED TO BE CLOSE TO THE SAME AS YESTERDAY'S... EXCEPT A LITTLE WARMER OVER THE EASTERN U.P. EVEN THE TRAJECTORY PROGS INDICATE VERY LITTLE CHANCE IN AIR MASS. HOWEVER...TODAY THE FORECAST SOUNDINGS INDICATING A LITTLE LESS LOW LEVEL CLOUDS. THUS MAY EXPECT A LITTLE WARMER TEMPERATURES DUE TO THE ADDITIONAL SUN. PLAN TO GO WITH JUST A LITTLE HIGHER TEMPERATURES THAN YESTERDAYS WHICH IS WHAT GUIDANCE SUGGEST ALSO. THE MID LEVEL RIDGE WILL SLIDE INTO WESTERN ONTARIO TONIGHT WHILE THE SURFACE RIDGE PUSHES INTO SOUTHWEST QUEBEC. A SHORTWAVE WILL RUN INTO THE RIDGE AND START TO BREAK IT DOWN. THE SURFACE LOW OVER KANSAS WILL TRAVEL INTO NORTHERN MISSOURI...PULLING A PORTION OF THE FRONTAL SYSTEM NORTHERN INTO CENTRAL ILLINOIS AND CENTRAL INDIANA. THE ACCOMPANYING LOW LEVEL MOISTURE OVER RUNNING THE FRONT WILL SHIFT INTO SOUTHERN WISCONSIN AND INTO LOWER MICHIGAN...STILL KEEP THE FORECAST AREA DRY. A 70 KNOT UPPER LEVEL JET MAX WILL SLIDE ACROSS NORTHERN LOWER MICHIGAN TONIGHT. KEEPING THE FORECAST AREA UNDER THE LEFT ENTRANCE REGION OF THE JET MAX. THUS WITH THE DRY AIR ENTRENCHED OVER THE FORECAST AREA PLAN TO KEEP THE FORECAST AREA DRY. FORECAST SOUNDINGS CONTINUE TO SHOW A DRY AIR MASS OVER THE FORECAST AREA FOR TONIGHT EXCEPT ALONG THE LAKE MICHIGAN SHORELINE. GFS SOUNDING DRAWING CLOUDS INTO THE FORECAST AREA AROUND 500MB AND ABOVE. THIS MAY REDUCE RADIATIONAL COOLING. WITH AN ABUNDANCE OF SUN FOR TODAY AND AN INCREASE CLOUD COVER TONIGHT...WILL KEEP TEMPERATURES A LITTLE WARMER FOR TONIGHT. 925MB TEMPERATURES ARE EXPECTED TO BE 1 TO 2 DEGREE C WARMER OVER THE WEST TONIGHT AND ABOUT THE SAME AS THIS MORNING OVER THE EAST. GUIDANCE SUGGESTING THE SAME. THE MID LEVEL RIDGE WILL SHIFT INTO EASTERN ONTARIO AND BEGIN TO FLATTEN OUT ON MONDAY. MEANWHILE...THE SHORTWAVE RUNNING INTO THE RIDGE WILL DEVELOP INTO A CLOSED LOW WILL DIP SOUTHEAST EAST BELOW THE RIDGE AND MOVE INTO CENTRAL MINNESOTA. OTHER WEAK SHORTWAVES ROTATING AROUND THE CLOSED LOW WILL SWEEP INTO THE FORECAST AREA. THE MISSOURI SURFACE LOW WILL BE FORCED INTO CENTRAL ILLINOIS. THE SURFACE RIDGE WILL CONTINUE TO STRETCH FROM EAST CENTRAL ONTARIO ACROSS THE FORECAST AREA THEN SOUTHWEST INTO EASTERN NEBRASKA...THE HIGH PLAINS FRONTAL SYSTEM WILL MEANDER INTO CENTRAL DAKOTAS. LOW LEVEL MOISTURE WILL CONTINUE TO BE VERY LIMITED AS THE ILLINOIS LOW WILL TEND TO KEEP THE MOISTURE CLOSE TO IT. GFS SUGGEST THAT THERE MAY BE ENOUGH MOISTURE OVER THE SOUTH END OF MENOMINEE COUNTY TO PRODUCE SOME RAIN...HOWEVER...ECMWF/NAM/GLOBAL MODELS CONTINUE TO SHOW IT WILL BE TOO DRY. THIS IS BECAUSE GFS IS MOST AGGRESSIVE WITH THE DEVELOPMENT OF THE SURFACE LOW AND MOVING IT INTO LOWER MICHIGAN. AS HPC POINTED OUT IN THE LATEST DISCUSSION...A PREFERRED NAM/GFS BLEND WOULD BE PREFERRED SOLUTION WHICH WOULD KEEP PRECIPITATION MAINLY TO THE SOUTH OF THE U.P. ON MONDAY. THIS IS ALSO SEEMS PREFERRED BY THE ENSEMBLE SOLUTION. THE MID LEVEL LOW WILL SHIFT INTO NORTHEAST IOWA MONDAY NIGHT. NAM CONTINUES TO KEEP THE LOW A LITTLE FURTHER SOUTH OF GFS. NAM ALSO IS A LITTLE SOUTH OF AND LESS AGGRESSIVE WITH THE SURFACE POSITION OF ASSOCIATED LOW. STILL LOOKING TO FAVOR A BLENDED SOLUTION SO WILL BE CUTTING BACK A LITTLE ON PRECIPITATION POTENTIAL. THE NAM CONTINUES TO BE A LITTLE SOUTH OF GFS SOLUTION FOR POSITIONS OF THE MID LOW ON TUESDAY...AS WELL AS BE QUITE BIT SOUTH AND LESS AGGRESSIVE WITH THE SURFACE LOW. THE POSITION OF THIS LOW WILL BE INSTRUMENTAL IN THE DEVELOP OF PRECIPITATION OVER THE FORECAST AREA. GFS KEEP SHOWERS GOING OVER THE EAST PART OF THE FORECAST AREA ON TUESDAY WHILE NAM KEEPS IT SOUTH OF THE FORECAST AREA. WILL CONTINUE WILL A SLIGHT CUT BACK ON CHANCE OF SHOWERS. TWO WEAK SHORTWAVES WILL SWEEP THROUGH UPPER MICHIGAN TUESDAY NIGHT AS THE MID LEVEL LOW MOVES OVER THE KCHI AREA. THE SURFACE LOW WILL EDGE INTO SOUTHERN LOWER MICHIGAN. A WARM FRONT LEADING THE LOW WILL MOVE INTO THE LOWER GREAT LAKES AS A TRAILING COLD FRONT SWEEPS INTO INDIANA. A WEAK RIDGE WILL MOVE OVER THE FORECAST AREA. DRY AIR ACCOMPANYING THIS SYSTEM WILL CAUSE THE CHANCE OF RAIN TO DIMINISH OVER THE WEST END OF THE U.P. DRY AIR WILL BRING MORE SETTLE WEATHER TO THE AREA ON WEDNESDAY. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ PREV DISCUSSION...DLG UPDATE...MZ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1040 AM EDT SUN SEP 10 2006 .UPDATE...12Z SURFACE/RUC ANALYSIS AND VIS/IR/WV IMAGERY SHOW SURFACE HIGH PRESSURE CENTERED ALONG THE NORTHERN LAKE SUPERIOR SHORELINE EMBEDDED UNDER NW FLOW ALOFT. VERY DRY AIR IS PRESENT ACROSS THE CWA AS DEPICTED BY THE 12Z APX SOUNDING WITH PWATS AT 0.32...WITH MOST OF THE MOISTURE RESIDING BELOW THE 825MB INVERSION. A SCT-BKN050 DECK AS BEEN PRESENT FOR MOST OF THE MORNING ACROSS FAR NE LOWER WHILE THE REST OF THE CWA REMAINS MOSTLY CLEAR NORTH OF M-72. MEANWHILE...A THICK BAND OF CLOUDS ORIGINATING FROM CONVECTION AHEAD OF A SHORTWAVE AND DEVELOPING LOW PRESSURE OVER KANSAS IS STREAMING NORTHEAST ACROSS CENTRAL WI/MI...JUST SOUTH OF THE CWA. THIS MOISTURE IS HITTING A WALL OF DRY AIR (850-500MB RH 15-25%)...ALIGNED WELL WITH THE 700 MB FRONT. WITH STRONG HIGH PRESSURE IN CONTROL...CLOUD COVER AND MAX TEMPS REMAIN THE MAIN CONCERN THIS AFTERNOON. EASTERLY WINDS IN THE LOW LEVELS WILL PERSISTENTLY ADVECT MOISTURE OFF OF LAKE HURON OVER NE LOWER AND THE TIP OF THE MITT THIS AFTERNOON WHICH WILL PROMOTE CU DEVELOPMENT. THE REST OF THE CWA SHOULD SEE SHALLOW CU DEVELOPMENT WHICH WILL MIX OUT DURING THE COURSE OF THE AFTERNOON LEAVING SKIES PARTLY TO MOSTLY SUNNY. THE EXCEPTION WILL OCCUR OVER THE SOUTHERN CWA. THE 700MB FRONT THAT IS BASICALLY THE EDGE OF THE MID LEVEL CLOUD SHIELD...WILL MOVE SLOWLY NORTH TODAY AND THINK THAT THESE CLOUDS WILL MAKE IT TO A LINE EXTENDING FROM TVC TO OSC. OTHERWISE...A QUIET DAY ON TAP WITH HIGHS IN THE LOWER TO MIDDLE 60S. MARINE...MID-LAKE BUOYS ARE ONLY SHOWING WINDS GUSTING BETWEEN 10-15KTS AND WAVES ARE UNDER THREE FEET. THIS MATCHES UP WELL WITH THE NOAA GREAT LAKES WAVE MODEL FORECASTS. WITH WINDS EXPECTED TO REMAIN STEADY THIS AFTERNOON...HAVE A HARD TIME JUSTIFYING KEEPING THE SMALL CRAFTS GOING SINCE WAVES LOOK TO BE IN THE 2 TO 4 FT RANGE...STILL CHOPPY BUT UNDER SMALL CRAFT CRITERIA. ZONES OUT SHORTLY MPC PREVIOUS DISCUSSION...ISSUED AT 355 AM EDT SUN SEP 10 2006 LATEST NORTHERN HEMISPHERIC WATER VAPOR IMAGERY EARLY THIS MORNING SHOWING ENERGETIC MID LEVEL FLOW ACROSS NOAM WITH LONGWAVE TROUGH AXIS DIGGING INTO THE GULF OF ALASKA AND ANOTHER LIFTING EAST OVER EASTERN CANADA/NORTHEASTERN CONUS. SANDWICHED BETWEEN THESE IS A MID LEVEL RIDGE AXIS EXTENDING FROM THE CANADIAN HIGH PLAINS TO THE NORTHWEST TERRITORIES. MORE SUBTLE SHORTWAVES ALSO EVIDENT...ONE DROPPING SOUTH OVER SOUTHWEST MANITOBA WITH ANOTHER MOVING EAST OVER NEBRASKA. AT THE SURFACE...1028 MB HIGH PRESSURE IS SLOWLY SLIDING SOUTHEAST ACROSS SOUTHERN ONTARIO WITH FRONTAL ZONE WELL SOUTH IN THE OHIO VALLEY. COOL NORTHEAST TO EAST FLOW (850 MB TEMPERATURES AROUND 2-3C) ROTATING AROUND HIGH GENERATING A RATHER EXTENSIVE AREA OF STRATOCUMULUS OVER NORTHERN LAKE HURON AS DELTA T/S APPROACH 16C. CLOUD DECK MAKING SLOW BUT STEADY PROGRESS INLAND AS IT FIGHTS VERY DRY AIR WITH PWATS PER 00Z APX SOUNDING OF ONLY 0.36 INCHES OR ABOUT 48 PERCENT OF NORMAL FOR THIS TIME OF YEAR. LOOKING WAY OUT INTO THE ATLANTIC...TROPICAL STORM FLORENCE BEGINNING TO MAKE LEFT HAND TURN SOUTH OF BERMUDA AS IT FEELS AFFECTS OF NORTHEAST CONUS TROUGH (SEE WWW.NHC.NOAA.GOV FOR LATEST FORECAST ON FLORENCE). FORECAST CONCERNS CENTERED ON CLOUDS AND TEMPERATURES THROUGH TONIGHT THEN INCREASING PRECIPITATION CHANCES THROUGH TUESDAY NIGHT. TODAY...LAKE EFFECT CLOUDS WILL CONTINUE TO BE A FACTOR ALONG AND EAST OF M-33 THIS MORNING AS WINDS COME AROUND TO A MORE EASTERLY DIRECTION AND MODERATE DELTA T/S REMAIN FAVORABLE FOR CLOUD GENERATION. EXPECT MUCH THE SAME TO HAPPEN TODAY AS YESTERDAY WITH CLOUDS MIXING OUT LATER THIS MORNING AND AFTERNOON WITH ALL THE MID LEVEL DRY AIR PRESENT. DID BUMP UP CLOUD COVERAGE A LITTLE IN SOUTHERN AREAS AS EXPANSIVE MID AND UPPER LEVEL CLOUD SHIELD SPREADING EAST FROM THE CENTRAL PLAINS LOOKS TO CLIP THESE AREAS. TEMPERATURES TODAY LOOKING TO STAY WELL BELOW SEASONAL NORMS WITH HIGHS ONLY MAKING IT TO THE LOWER 60S. TONIGHT...LAKE CLOUDS LOOK TO SPREAD BACK INTO EASTERN AREAS AS 850 MB TEMPERATURES OVER NORTHERN LAKE HURON FALL TO AROUND 1-2C AND EASTERLY FLOW CONTINUES. HIGH CLOUDS SPREADING WELL IN ADVANCE OF DEVELOPING CENTRAL PLAINS STORM SYSTEM SHOULD MOVE INTO SOUTHERN ZONES. THEREFORE...BUMPED UP TEMPERATURES A FEW DEGREES IN THESE AREAS. ELSEWHERE...STILL EXPECTING PATCHY FROST IN THE TYPICAL COLDER LOCATION OF THE NORTHERN LOWER AND EASTERN UPPER WITH LOWS FALLING INTO THE MID 30S. AROUND THE REMAINDER OF THE AREA EXPECT LOWS IN THE UPPER 30S TO LOWER 40S. MONDAY...SIGNIFICANT CHANGES STARTING WITH THIS PERIOD AS AFOREMENTIONED SHORTWAVES CONSOLIDATE OVER THE NORTHERN PLAINS. LAST SEVERAL RUNS FROM VARIOUS MODELS...EXCLUDING THE GFS...DAMPENED THIS SYSTEM AS IT ENCOUNTERED EASTERN TROUGH AXIS WHICH IN TURN FORCED SYSTEM TO REMAIN WELL SOUTH OF REGION. HOWEVER...LATEST 00Z UKMET AND GFS ALMOST A SPOT ON MATCH WITH CLOSED MID LEVEL CIRCULATION OVER EASTERN MINNESOTA BY MONDAY EVENING AND ASSOCIATED SURFACE LOW OVER CENTRAL ILLINOIS. FURTHER SUPPORT PROVIDED BY TRENDS IN BOTH 00Z NAM-WRF AND 12Z ECMWF OF A MORE WRAPPED UP AND FARTHER NORTH SOLUTION...ALBEIT STILL A BIT FARTHER SOUTH THAN THE UKMET/GFS SOLUTIONS. OVERALL EVOLUTION LOOKS TO HINGE ON INTERACTION BETWEEN FLORENCE AND EAST COAST TROUGH AND HOW FAST COMBINED SYSTEMS PULL OUT. A MORE ESTABLISHED EASTERN TROUGH WOULD FAVOR A FARTHER SOUTH AND MORE DAMPENED SOLUTION AS CENTRAL PLAINS ENERGY APPROACHES WOULD BE CONFLUENT ZONE OVER THE LAKES. AT THIS TIME WILL HEDGE FORECAST TOWARDS RATHER CONSISTENT GFS SOLUTION WITH SOME ACKNOWLEDGEMENT OF A POTENTIALLY FARTHER SOUTH PLACEMENT. WHAT ALL THIS MEANS FOR OUR AREA IS TO ADD SOME LOW POPS FAR SOUTHERN ZONES MONDAY AFTERNOON AS WARM FRONT BEGINS TO BOW NORTH ACROSS THE SOUTHERN LAKES AND ISENTROPIC ASCENT INCREASES. WILL DOWNPLAY OVER ZEALOUS GFS QPF FIELDS FOR MONDAY AS DRY AIR IN PLACE WILL BE HARD INITIALLY TO SCOUR OUT. MONDAY NIGHT THROUGH TUESDAY NIGHT...ADDED POPS THROUGH THIS PERIOD AS LOW MOVES UP THROUGH SOUTHERN MICHIGAN PUTTING OUR AREA IN FAVORABLE DEFORMATION ZONE. GFS DOES SHOW SOME IMPRESSIVE 300-305K ISENTROPIC ASCENT WITH MIXING RATIONS APPROACHING 8G/KG MONDAY NIGHT. DID NOT WANT TO GO OVERBOARD ON POPS GIVEN MODEL DISCREPANCIES. IF GFS/UKMET VERIFY LIKELY POPS WILL BE NEEDED FOR MUCH OF THIS PERIOD. REST OF FORECAST UNCHANGED. MARINE...WILL GO AHEAD AND EXTEND SCA FROM PRESQUE ISLE LIGHT TO ALABASTER THROUGH 00Z MONDAY. CONTINUATION OF IMPRESSIVE OVER LAKE INSTABILITY AND LONG EASTERLY FETCH WILL ALLOW WAVES TO CONTINUE IN THE 3-5 FOOT RANGE. MSB && .APX...WATCHES/WARNINGS/ADVISORIES...FROST ADVISORY...THIS MORNING...MIZ008-015. && $$ mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE ABERDEEN SD 1100 AM CDT SUN SEP 10 2006 .UPDATE...REVISITED MAX T GRID ACROSS THE EASTERN FA WITH IFR STRATUS DECK WELL ESTABLISHED ACROSS THIS AREA. NOT EXPECTING ANY PORTION OF OVERCAST CONDITION TO ERODE TODAY...SO WILL BE LUCKY TO SEE THE MERCURY RISE GREATER THAN A CATEGORY-WORTH OF TEMPERATURE THROUGH THIS AFTERNOON. ALSO NEEDED TO TWEAK SKYCOVER GRIDS WHICH ARE A BARE TO FORECAST TODAY WRT WHEN AND WHERE ANY AREAS MAY DISSIPATE ENTIRELY OR JUST SCATTER OUT. UPDATED GRIDS/WORDS ARE OUT. DORN && .PREV DISCUSSION... (ISSUED 402 AM CDT SUN SEP 10 2006) SHORT TERM...TODAY THROUGH TUESDAY NIGHT SKY COVER CONTINUES TO BE THE MAIN ISSUE IN THE SHORT TERM...AND NOW PRECIP CHANCES FOR MONDAY AFTERNOON AND EVENING AS A SFC FRONT AND UPPER WAVE MOVE INTO THE AREA. STRATUS DECK HOLDING THICK SOUTH OF A MBG-ABR-VVV LINE WITH CEILINGS FROM 500-2500 FT ALL THE WAY TO THE SD/NEB BORDER. NORTH OF THIS LINE A SCT-BKN025-040 CLOUD DECK EXISTS WITH A SHARP CUTOFF TO CLEAR SKIES JUST NORTH OF THE ND/SD BORDER. THIS HAS MATCHED UP WELL WITH MODEL 925MB RH FIELDS THROUGHOUT THE EARLY MORNING HOURS. RUC/HI RES NAM WOULD SUGGEST A GRADUAL BREAKUP OF CLOUDS ACROSS CENTRAL SD THIS MORNING...BUT STRATUS BEING MORE STINGY ACROSS EASTERN SD AND EXTREME WEST CENTRAL MN. HAVE LEFT SKY COVER GRIDS TO REFLECT A MOSTLY CLOUDY TO CLOUDY WORDING FOR THIS AFTERNOON ACROSS THE I-29 CORRIDOR...ESPECIALLY SOUTH OF SISSETON. HAVE ALSO ADDED MORNING FOG FROM PIERRE SOUTH AS VIS HAS BEEN COMING DOWN ALL MORNING AND IS NOW BETWEEN 1-2SM. OVERNIGHT STRATUS MAKES A RETURN TO THE NORTH AND WEST TO COVER MOST OF EASTERN SD AND WEST CENTRAL MINNESOTA AS 925MB FLOW PERSISTS FROM THE EAST/SOUTHEAST. THERE WAS SOME QUESTION AS TO JUST HOW FAR NORTH STRATUS WOULD ADVANCE SUNDAY NIGHT. MODELS SHOW A PLUME OF HIGH RH HEADING NORTH UP THE RED RIVER VALLEY SO HAVE CLOUDY SKY GRIDS ACROSS THE ENTIRE EASTERN PORTION OF THE CWA. STRATUS EARLY THIS MORNING STOPS AT THE ND/SD BORDER BUT 925MB WINDS ARE MORE ESE. MODELS SHOW WINDS TURNING MORE SE/SSE WHICH WOULD SUGGEST STRATUS COULD ADVANCE FARTHER NORTH SUNDAY NIGHT THAN WHAT HAPPENED THIS MORNING. THINK STRATUS WILL HAVE A TOUGH TIME DEPARTING ON MONDAY ALSO AND KEPT SKY COVER RATHER HIGH ACROSS THE EASTERN COUNTIES INTO THE EARLY AFTERNOON. ATTENTION THEN TURNS TO SYSTEM MOVING INTO THE CENTRAL DAKOTAS MONDAY AFTERNOON. SFC TROUGH CURRENTLY LOCATED ACROSS CENTRAL MT IS FORECAST TO MOVE INTO THE WESTERN DAKOTAS BY MONDAY AFTERNOON. NAM IS A BIT MORE AGGRESSIVE WITH THE FRONT AND BRINGS IT FARTHER EAST INTO CENTRAL DAKOTAS WHEREAS GFS LOOKS LIKE IT WANTS TO WASH IT OUT MONDAY EVENING. MINIMAL INSTABILITY DEVELOPS ACROSS WESTERN DAKOTAS MONDAY AFTERNOON AND A FEW MODELS ALSO SHOWING SMALL QPF ALONG FRONT. HAVE INTRODUCED SLIGHT CHANCE POPS FOR THE FAR NORTHWESTERN CWA FOR MONDAY AFTERNOON. LONG TERM...WEDNESDAY THROUGH SUNDAY MEDIUM RANGE IN FAIR AGREEMENT TODAY. WILL END UP WITH A BLEND OF THE GFS AND THE HPC GUIDANCE. THE EXTENDED PERIOD OPENS WITH H5 UPPER RIDGE FOLDING OVER THE TOP OF THIS AREA AS A PACIFIC STORM SYSTEM MOVES ONSHORE NEAR THE BRITISH COLUMBIA COAST. BY THURSDAY MORNING THE UPPER FLOW IN THIS AREA IS BECOMING SOUTHWEST AND COOLER PACIFIC AIR IS FORCING ITS WAY IN FROM THE NORTH. THERE IS AN OLD BAROCLINIC ZONE LYING ALONG THE BORDER OF NORTH AND SOUTH DAKOTA. TRIMMED BACK THE ONSET OF PRECIPITATION AS THIS MODEL RUN IS A LITTLE SLOWER PUSHING INTO THE AREA. FROM THAT POINT ON THE UPPER FLOW BECOMES INCREASINGLY SOUTHWEST AS THE PACIFIC LOW DIGS ALONG THE WEST COAST OF THE UNITED STATES. AFTER THIS IT WILL INVOLVE TIMING OF THE ENERGY THAT ROUNDS THE TROUGH BASE AS MOVES OUT ON THE PLAINS. EXPECT THE TIMING OF PRECIPITATION WILL BE ABLE TO BE SHAVED BACK CONSIDERABLY AS EACH WAVE BECOMES MORE CLEARLY DEFINED. AT THIS POINT IT SEEMS THE BEST WAY TO HANDLE THE PERIOD IS LONG DURATION LOW PROBABILITY POPS. TEMPERATURES WERE IN GOOD SHAPE. FEW CHANGES WERE MADE. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ TARVER/KEEFE sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BROWNSVILLE TX 930 AM CDT SUN SEP 10 2006 .DISCUSSION...THE MORNING CONVECTION HAS DISSIPATED OR HAS MOVED NORTH AND EAST OF THE BRO CWA FOR THE MOMENT. HOWEVER...THE 12Z BRO SOUNDING SHOWS A PRETTY MOIST AND UNSTABLE ENVIRONMENT STILL IN PLACE OVER THE CWA WITH A PWAT OF 2.33 INCHES AND AN LI OF -6.0. THE RUC AND NAM GUIDANCE MAINTAINS AN AREA OF DECENT 500 MB VORTICITY OVER THE WESTERN HALF OF THE CWA THROUGHOUT THE DAY AND THIS WILL PROVIDE ENOUGH UVV TO MAINTAIN THE THREAT OF CONVECTION AS PER THE MAV AND MET GUIDANCE WHICH IS IN PRETTY GOOD AGREEMENT IN THE SHORT TERM. AFTERNOON HEATING WILL ALSO ENHANCE THE LOW LEVEL CONVERGENCE AND LIFT LATER TODAY WHICH WILL HELP REGERATE ADDITIONAL CONV LATER TODAY AND INTO THE EARLY EVENING. MAV TEMPERATURES FOR THIS AFTERNOON MAY BE A BIT HIGH CONSIDERING THE INCREASED POTENTIAL FOR CONV AND CLD COVER. SO WILL LEAN TOWARDS THE SLIGHTLY COOLER MET NUMBERS. ALTHOUGH THE RAINFALL FROM YESTERDAY HAS CONSIDERABLY LOWERED THE FFG FOR THE REGION...THE GUIDANCE IS STILL PRETTY HIGH AND BELIEVE THAT THE GROUND WILL LIKELY BE ABLE TO HANDLE ANY ADDITIONAL HVY RAIN IN THE SHORT TERM. ALSO THE AREAL COVERAGE OF THE CONV HAS BEEN SPREAD OUT ENOUGH AND THE CELLULAR MOVEMENT HAS BEEN PRETTY FAST TO LIMIT THE HVY RAIN COVERAGE AND DURATION. SO DO NOT BELIEVE THAT A FFA IS NEEDED AT THE MOMENT. HOWEVER...HAVE UPDATED THE ZFP TO MENTION LOCALLY HEAVY RAINFALL POSSIBLE. && .MARINE...AT 8AM BUOY020 REPORTED SOUTH WINDS AT 12KTS AND SEAS 2.3 FEET. WEAK HIGH PRESSURE EXTENDING ACROSS THE GULF WILL CONTINUE TO PRODUCE LIGHT SOUTHEAST FLOW THROUGH TUESDAY. AN UNSTABLE AIRMASS AND WEAK COASTAL TROUGHING WILL LEAD TO CONTINUED SHOWER AND THUNDERSTORM ACTIVITY. MARINERS CAN EXPECT BRIEF HEAVY DOWNPOURS...QUICKLY SHIFTING WINDS...AND OCCASIONAL LIGHTNING. A FRONTAL BOUNDARY WILL SHIFT INTO THE REGION LATER ON TUESDAY SHIFTING WINDS TO THE EAST AND NORTHEAST. SEAS WILL REMAIN 1 TO 2 FEET UNTIL THE FRONT ARRIVES...WHEN SEAS WILL INCREASE TO 3 TO 4 FEET AT THE BUOY. && .AVIATION...SHOWER AND THUNDERSTORM ACTIVITY WILL CONTINUE IN THE REGION THROUGH THE NEXT 24 HOURS. EXPECT BRIEF LOCAL DOWNPOURS WITH MVFR CIGS...VIS 1 TO 2 MILES...AND VARIABLY GUSTY WINDS. FLIGHT CORRIDORS TO THE NORTH AND NORTHEAST WILL ALSO EXPERIENCE SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS. AREAS OUTSIDE PRECIPITATION WILL SEE VFR CONDITIONS WITH OVERCAST CIGS ABOVE 12KFT. && .BRO WATCHES/WARNINGS/ADVISORIES...NONE. && $$ THIS PRODUCT IS ALSO AVAILABLE ON OUR INTERNET WEB PAGE AT: HTTP://WWW.SRH.NOAA.GOV/BRO SYNOPTIC/GRIDS...60 MARINE/AVIATION...64 MESO...CAMPBELL tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 252 PM MDT SUN SEP 10 2006 .SHORT TERM... (TONIGHT AND MONDAY) MAIN FORECAST CHALLENGE WILL BE TIMING AND COVERAGE OF PRECIPITATION OVER THE NEXT 24 HOURS. CURRENTLY...CU AND TOWERING CU DEVELOPING OVER THE MOUNTAINS AND HIGH VALLEYS EARLY THIS AFTERNOON PER VISIBLE AND INFRARED SATELLITE IMAGERY ANIMATIONS. MORE STABLE SC WAS ACROSS MUCH OF EASTERN CO EARLY THIS AFTERNOON. THIS IS IN THE AREA OF A STRONGER CONVECTIVE INHIBITION REGION PER LAPS DATA AND CONVECTIVE TEMPERATURES NOT REACHED YET. REGIONAL RADARS SHOWING ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS OVER THE MOUNTAINS AND ADJACENT VALUES. SURFACE BASED CAPES ARE 200-1000 J/KG OVER THE MOUNTAINS AND HIGH VALLEYS WITH LIFTED INDICES -2C TO -4C. POTENTIAL FOR MARGINAL SEVERE HAIL POSSIBLE. WATER VAPOR IMAGERY AND RUC MODEL UPPER AIR ANALYSES AGAIN SHOWING FLAT WESTERLY FLOW. THERE ARE VERY MINOR SHORTWAVE TROUGHS RIPPLING THROUGH THIS FLOW ACROSS UT AND CO. FIRST LIGHTNING STRIKES SHOWED UP IN WEST CENTRAL CO JUST AHEAD OF ONE OF THESE SHORTWAVES EARLY THIS AFTERNOON. TONIGHT...TOUGH CALL IN SAYING WHICH CWFA AREA WILL HAVE THE BETTER CHANCE FOR POPS AND QPF...SO CURRENTLY BROADBRUSH POP SCENARIO LOOKS GOOD. THE BETTER THREAT MIGHT ACTUALLY BE DOWN ACROSS THE SOUTHERN FOOTHILLS AND EASTWARD INTO THE SOUTHEASTERN CO PLAINS. THE NEXT CHALLENGE IS WHEN WILL THE PRECIPITATION CHANCES END. THE 12KM WRF CONTINUES TO BE OVERDOING PRECIPITATION DEVELOPMENT AND ENDING. I CANNOT SEE ANY SIGNIFICANT SYNOPTIC SCALE SYSTEM KEEPING THE PRECIPITATION GOING AFTER MIDNIGHT ACROSS MUCH OF SOUTHEAST CO. I GUESS A ROGUE OUTFLOW BOUNDARY COULD KEEP THINGS GOING...BUT THE AIR MASS BECOMES MORE STABLE AFTER MIDNIGHT. AFTER LOOKING AT LAST NIGHTS...RADAR...LIGHTNING...AND SATELLITE DATA...WILL DROP MUCH OF THE POP AND PRECIPITATING WEATHER AFTER MIDNIGHT EXCEPT FOR SOME LOW POPS DOWN AROUND THE SOUTHERN FOOTHILLS AND PARTS OF SOUTHEASTERN CO PLAINS. MY GUT SAYS THAT MIGHT BE OVERDONE GIVEN THE TRACK RECORD OF THE 12KM WRF (AND THE GFS TYPICALLY HANGING ONTO TO TOO MUCH PRECIPITATION). MINIMUM TEMPERATURES STARTING TO BECOME MORE OF A CHALLENGE IN LOW LYING AREAS AS FALL APPROACHES. THE HEART OF THE SAN LUIS VALLEY GOT DOWN TO THE MIDDLE 30S(ALS..34F) AND KPUB WAS DOWN IN THE MIDDLE 40S...WHICH WERE BELOW MOS GUIDANCE YESTERDAY. THERE ARE HINTS OF THE SFC-PBL TO BECOME MOIST TOWARDS MORNING ACROSS SOUTHEASTERN CO AND THE SAN LUIS VALLEY...SO THE POTENTIAL FOR PATCHY (GROUND) FOG CONTINUES. CURRENT DIGITAL FORECAST DATABASE HAD MENTION FROM KCOS DOWN TO KLAA...SO WILL CONTINUE AND LINK TO RH VALUES OF 95% OR GREATER. ALSO INCLUDED PATCHY FOG IN SAN LUIS VALLEY. ACTUALLY SOME FROST MAY BE POSSIBLE OF TEMPERATURES CAN GET DOWN TO 32F-33F WITH HUMIDITY VALUES GREATER THAN 90 PERCENT. MONDAY...POTENTIAL FOR SOME EARLY MORNING (GROUND) FOG IN AFOREMENTIONED AREAS. OTHERWISE...PERSISTENCE SEEMS TO BE A GOOD FORECAST TOOL. WEAK SHORTWAVE TROUGHS SHOULD MOVE THROUGH THE NORTHWESTERLY FLOW. TRIED TO ENHANCE THE PRECIPITATION TIMING AND STARTING THE POTENTIAL OVER THE MOUNTAINS AND HIGH VALLEYS EARLY IN THE AFTERNOON AND THEN SPREAD THE POTENTIAL ACROSS ALL OF THE CWFA MIDDLE TO LATE AFTERNOON. AGAIN...THINK 12KM WRF IS STARTING PRECIPITATION TOO EARLY. STILL TOUGH TO PIN-POINT THE BEST POP QPF AREAS...SO A MORE BROADBRUSH LOW POPS IS PROBABLY THE WAY TO GO. CURRENT MAXIMUM TEMPERATURES LOOK ON TARGET AND CLOSE ENOUGH TO MOS GUIDANCE...SO LITTLE ALTERATIONS NEEDED THERE. METZE .LONG TERM... (MONDAY NIGHT THROUGH SUNDAY) LONG TERM CONCERNS INCLUDE PRECIP CHANCES MONDAY NIGHT ALONG WITH THE AMOUNT OF WARMING THROUGH THE WEEKEND. MONDAY NIGHT-TUESDAY...MODELS FAIRLY CONSISTENT WITH EMBEDDED SHORT WAVE IN THE NORTHERLY FLOW ALOFT MOVING ACROSS THE NORTHERN AND CENTRAL HIGH PLAINS MONDAY NIGHT...SHOOTING A BACK DOOR COLD FRONT ACROSS EASTERN COLORADO THROUGH EARLY TUESDAY MORNING. WITH RUN TO RUN CONSISTENCY...HAVE ADDED POPS ACROSS THE EASTERN MTS AND PLAINS MONDAY EVENING AS LIFT AND MOISTURE ASSOCIATED WITH BOUNDARY MOVES ACROSS THE AREA. LATEST NAM CONTINUES TO LOOK OVERDONE WITH QPF THROUGH THE OVERNIGHT HOURS...AND WILL END POPS ACROSS THE PLAINS BY 06Z. FOR TUESDAY...MUCH DRIER AIR PROGGED TO MOVE INTO THE REGION AS UPPER RIDGING BUILDING ACROSS THE GREAT BASIN KEEPS NORTHERLY FLOW ALOFT ACROSS THE REGION. PREVIOUS SHIFT CUT POPS ACROSS THE AREA...AND HAVE FOLLOWED SUITE...KEEPING ONLY ISOLATED CHANCES ACROSS MAINLY THE SW MTS. WEDNESDAY-FRIDAY...UPPER LEVEL RIDGING ACROSS THE GREAT BASIN ON TUESDAY FLATTENS ACROSS THE STATE WEDNESDAY AS LARGE UPPER LOW DEVELOPS ACROSS THE PAC NW COAST. UPPER LOW PROGGED TO DEEPEN ACROSS THE NORTHERN GREAT BASIN THROUGH FRIDAY...WITH WITH SHORT WAVE ENERGY EJECTING ACROSS THE GREAT BASIN THURSDAY AND ACROSS THE NORTHERN ROCKIES ON FRIDAY. WITH WARM AIR ALOFT (+10C TO +14C AT H7) AND DEVELOPING DOWNSLOPE FLOW...SHOULD SEE TEMPS WARMING TO ABOVE SEASONAL AVERAGES THROUGH THE PERIOD. WITH SOME INCREASING MOISTURE IN THE SW FLOW...HAVE KEPT ISOLATED TO SCATTERED POPS ACROSS THE HIGHER TERRAIN THU AND FRI...WITH BEST POPS ACROSS THE SAN JUANS. HAVE ALSO KEPT ISOLATED POPS ACROSS THE EASTERN PLAINS ON FRIDAY...WITH POSSIBLE CONVERGENCE ALONG DEVELOPING LEE TROUGH/DRY LINE ACROSS THE FAR EASTERN PLAINS. SATURDAY-SUNDAY...MODELS STILL DIVERGING SOMEWHAT THROUGH THE LATE WEEKEND...THOUGH LATEST GFS AND ECMWF SLOWLY LIFTING UPPER LOW ACROSS THE NORTHERN GREAT BASIN AND NORTHERN TIER OF STATES KEEPING GENERALLY WARM AND DRY SW FLOW ALOFT ACROSS THE STATE. GFS IS A TAD QUICKER AND FURTHER SOUTH WITH SYSTEM...WHICH HINTS AT COLD FRONTAL PASSAGE ACROSS THE STATE ON SUNDAY. HOWEVER...WITH TIMING OF THIS SYSTEM IN DOUBT...HAVE KEPT CURRENT DRY FORECAST WITH AT OR ABOVE SEASONAL TEMPS THROUGH SUNDAY. -MW && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 17/23 co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 453 PM EDT SUN SEP 10 2006 .DISCUSSION... FCST CONCERN FOCUSES ON TIMING OF RAIN INTO FCST AREA MON INTO TUE WITH APPROACH OF DEVELOPING SYSTEM OVER THE CENTRAL PLAINS. WATER VAPOR IMAGERY...12Z RAOBS AND RUC ANALYSIS SHOW RIDGE CONTINUING TO AMPLIFY OVER THE WRN CONUS WHILE HURRICANE EMILY IS MOVING NORTH THROUGH THE ATLANTIC TOWARD MID-LVL TROUGH OVER ERN CANADA. THIS ALL POINTS TOWARD DEVELOPMENT OF MORE AMPLIFIED TROUGH OVER THE CENTRAL PLAINS AND MIDWEST OVER THE NEXT SEVERAL DAYS...AND GFS/UKMET AND NOW CANADIAN ALL ADVERTISE DEVELOPMENT OF MORE AMPLIFIED TROUGH AND CLOSED LOW OCCURRING OVER THE MIDWEST AND WRN LAKES. TONIGHT...CUMULUS CLOUDS OVER THE SCNTRL COUNTIES LOOK LIKE THEY MAY BE ENHANCED SOME BY UPSLOPE/ONSHORE SE FLOW OFF NRN LAKE MI/BAY OF GREEN BAY. WOULD EXPECT THESE CLOUDS TO PERSIST THROUGH MUCH OF THE NIGHT AS LEADING EDGE OF CIRRUS CLOUD SHIELD FROM CENTRAL PLAINS SYSTEM ADVANCES NORTH TOWARD THE UPPER GREAT LAKES. VERY DRY AIR AS EVIDENCED BY 12Z KAPX AND KINL SNDGS MAY TEND TO KEEP THICKER CLOUDS FROM REACHING INTO NRN TIER COUNTIES OF FCST AREA...BUT DO EXPECT SOME INCREASE IN CLOUDS OVER SRN COUNTIES. CLOUDS WILL OBVIOUSLY IMPACT MIN TEMPS TONIGHT...BUT STILL THINK THERE WILL BE ENOUGH OF A PERIOD OF CLEARING TO ALLOW FOR SOME DECENT RADIATIONAL COOLING TO OCCUR. WILL CONTINUE TO INCLUDE SOME PATCHY FROST FOR INLAND LOCATIONS OF FAR WRN...NCNTRL AND ERN COUNTIES WITH TEMPS REACHING THE MID TO UPR 30S IN SOME SPOTS. TEMPS WILL STAY MORE IN THE 40S ALONG THE SHORELINE AREAS AND FOR FAR SCNTRL COUNTIES WHERE HIGH CLOUDS WILL THICKEN. AS SHORTWAVE ENERGY FROM ERN ND AND NRN MN DIGS INTO CENTRAL PLAINS TROUGH...TONIGHT INTO MON...MID-LVL TROUGH IS EXPECTED TO TAKE ON MORE NEGATIVE TILT CARVING OUT CLOSED LOW OVER SRN MN PER GFS/UKMET. ASSOCIATED SFC SYSTEM AND INVERTED TROUGH WILL TEND TO PUSH NORTH TOWARD THE UPR GREAT LAKES. INCREASING 300K ISENTROPIC ASCENT AHEAD OF SYSTEM WILL DRIVE CLOUDS/PCPN NORTH TOWARD UPR MI ON MON. BELIEVE 12Z GFS MAY STILL BE TOO QUICK TO DRIVE PCPN NORTH GIVEN VERY AIR IN PLACE. SO FOLLOWED CANADIAN/UKMET SOLNS MORE FOR TIMING OF PCPN BRINGING IN CHC OF PCPN BY LATE AFT MON FOR FAR SCNTRL COUNTIES THEN SPREAD CHC POPS NORTH ACROSS THE REST OF CENTRAL AND ERN FCST AREA MON NIGHT INTO TUE WITH SLIGHT CHC POPS OVER THE WRN COUNTIES. EVEN WENT LIKELY POPS ACROSS FAR SE LOCATIONS ON EDGE OF BETTER 300K ISENTROPIC ASCENT AS INDICATED BY FCST MODELS. TAPERED OFF OR ENDED RAIN FROM WEST TUE NIGHT INTO WED AS MODEL CONSENSUS SHOWS SYSTEM AND ASSOC BEST ISENTROPIC LIFT MOVING WELL E OF THE FCST AREA BY THIS TIME. EXTENDED (THU-SUN)...MID-LVL RIDGING BUILDS IN MORE OVER THE WRN LAKES THU INTO THU NIGHT WHICH SHOULD KEEP MUCH OF FCST AREA DRY WITH 8H TEMPS FCST OF 12-14C ALLOWING MAX TEMPS TO WARM BACK INTO THE 70S FOR LATE WEEK. FOLLOWED BLEND OF 00Z ECMWF AND GFS ENSEMBLE FOR FRI INTO SUN WHICH INDICATES FRONTAL BOUNDARY SAGGING SLOWLY SE ACROSS UPR MI. PUT IN CHC OF TSRA FRI FOR WRN UPR MI AND THEN BROUGHT A CHC OF SHRA ACROSS THE ENTIRE FCST AREA SAT INTO SUN. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ VOSS mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 405 PM EDT SUN SEP 10 2006 .DISCUSSION...18Z SURFACE/RUC ANALYSIS AND VIS/IR/WV IMAGERY SHOWS A BROAD UPPER LEVEL TROUGH OVER THE GULF OF ALASKA AND A TROUGH LIFTING TO THE NE OVER QUEBEC. A RATHER BROAD RIDGE IS CENTERED OVER CENTRAL MANITOBA AND SASKETCHEWON. OVER THE GREAT PLAINS... A SHORTWAVE IS HELPING DEVELOP A SURFACE LOW OVER EASTERN KANSAS WITH A WARM FRONT EXTENDING ACROSS MISSOURI AND SOUTHERN IL. ISENTROPIC LIFT ON THE 300K AND 305K SURFACES IS HELPING TO PRODUCE AN AREA OF LIGHT RAIN ACROSS NORTHERN IL/SOUTHERN WI...BUT IS HAVING A HARD TIME MAKING IT ACROSS LAKE MICHIGAN. ELSEWHERE...STRONG SURFACE HIGH CENTERED OVER SOUTHERN ONTARIO PLACING THE CWA IN DRY ENE LOW LEVEL FLOW. THIS FLOW HAS BEEN ADVECTING MOISTURE FROM LAKE HURON ACROSS NE AND NORTH CENTRAL LOWER MICHIGAN KEEPING SKIES PARTLY TO MOSTLY CLOUDY UNDER A STRATU-CU FIELD. ONE SHOWER WAS REPORTED AT ALPENA THIS AFTERNOON. HIGH PRESSURE AND STRONG SUBSIDENCE WILL KEEP PRECIP AT BAY...AND THEREFORE...CLOUDS AND TEMPS ARE THE MAIN FORECAST CONCERNS TONIGHT...THEN THE ATTENTION TURNS TO PRECIP FROM THE SYSTEM OVER THE PLAINS TOMORROW. TONIGHT...SURFACE HIGH PRESSURE SLIDES EAST OVER WESTERN QUEBEC WITH ITS RIDGE AXIS EXTENDING WEST ACROSS SOUTHERN ONTARIO AND LAKE SUPERIOR. VERY DRY AIR EASTERLY FLOW FROM THIS HIGH PRESSURE WITH PWATS OF 0.4-0.5IN WILL REMAIN OVER AREA. THIS EASTERLY FLOW WILL KEEP ADVECTING MOISTURE FROM LAKE HURON ONSHORE (LAKE-850MB TEMP DIFFERENCE AROUND 16C)...BUT WILL KEEP SKIES SCATTERED ACROSS NE LOWER WITH SUCH DRY LOW LEVELS ABOVE 850MB. A SIMILAR PROFILE EXISTED LAST NIGHT AND SKIES REMAINED SCATTERED FOR THE MOST PART. MEANWHILE...LOW PRESSURE DEVELOPING OVER KANSAS WILL SLOWLY MOVE NE OVER NORTHERN MO. CONVECTIVE DEBRIS AND ISENTROPIC LIFT ON THE 305K AND 310K LEVELS WILL SPREAD MID AND UPPER LEVEL CLOUDS FROM NORTH TO SOUTH OVER NORTHERN LOWER. THE VERY DRY AIRMASS IN PLACE WILL SLOW DOWN THE MOISTURE ADVANCEMENT...BUT SHOULD WORK ITS WAY OVER MUCH OF NORTHERN LOWER. ANY PRECIP SHOULD STAY TO THE SOUTH WITH THE VERY DRY LOW LEVELS (850-700MB RH 15-30%). THESE CLOUDS WILL KEEP TEMPERATURES MUCH WARMER THAN LAST NIGHT...BUT COULD SEE TEMPS DIPPING INTO THE MIDDLE 30S ACROSS INLAND AREAS OF THE TIP OF THE MITT WHERE CLOUDS WILL ARRIVE LAST. WILL KEEP PATCHY FROST ACROSS EASTERN UPPER WHERE SKIES WILL REMAIN MOSTLY CLEAR. MARINE...EAST WINDS 10 TO 15 KNOTS AND UNSTABLE CONDITIONS OVER THE LAKES WILL PRODUCE WAVES IN THE 2 TO 4 FOOT RANGE BUT UNDER SMALL CRAFT ADVISORY CRITERIA. MPC MONDAY THROUGH WEDNESDAY...STILL SIGNIFICANT MODEL DIFFERENCES AND FORECAST UNCERTAINTY THROUGH MIDWEEK IN REGARD TO MID LEVEL TROUGH/PSEUDO CUTOFF FEATURE FORECAST TO DEEPEN OVER THE MIDWEST... SLOWLY WORK THROUGH THE GREAT LAKES/OHIO VALLEY...AND NORTHWARD PROGRESSION OF AN ASSOCIATED SFC LOW AND PRECIP INTO NRN MICHIGAN. GFS/UKMET STILL THE DEEPEST AND FURTHEST NORTH COMPARED TO THE NAM/ECMWF AND EVEN THE NGM (REMEMBER THE NGM?). 12Z NAM/GFS INITIALIZATION NOT REVEALING ANY GLARING ERRORS THAT MIGHT LEAD TO SUCH DIFFERENCES...EXCEPT THAT THE NAM IS A LITTLE TOO WEAK WITH THE JET STREAK ACROSS MICHIGAN THIS MORNING. ALTHOUGH DIFFICULT TO FIND A REASON TO LEAN ONE WAY OR THE OTHER... STILL HAVE A HARD TIME BELIEVING THE GFS IN REGARD TO THE DEGREE OF AMPLIFICATION OF THE MID LEVEL TROUGH ACROSS THE UPPER MIDWEST ON MONDAY...AND ASSOCIATED SFC LOW DRIVING UP THROUGH THE STATE INTO STRONG DRY CANADIAN HIGH PRESSURE. REGIONAL RADAR PLOT/SATELLITE DATA DOES REVEAL POTENT WAVE NOW IN WESTERN IOWA AND A SUBSTANTIAL PRECIP SHIELD FROM NE IOWA INTO SW WISCONSIN. BUT NORTHWARD PROGRESSION HAS THUS FAR BEEN HAMPERED BY THE DRY AIR OVER THE NRN GREAT LAKES...ALTHOUGH SOME EASTWARD EXPANSION OF RADAR ECHOS NOW TAKING SHAPE TOWARD SOUTHERN LOWER MICHIGAN LATE THIS AFTERNOON ACROSS THE TIGHT BAROCLINIC ZONE. BELIEVE THE NORTHWARD PROGRESSION WILL CONTINUE TO BE HAMPERED OVER THE NEXT FEW DAYS AND HENCE WILL CONTINUE TO FAVOR THE DRIER NAM WHICH KEEPS MAJORITY OF PRECIP SOUTH OF THE AREA AND RESULTS IN CHANCE POPS FOR THE CWA THROUGH TUESDAY NIGHT. CAN MAKE AN ARGUMENT TO STRETCH POPS INTO WEDNESDAY AS THIS SYSTEM WILL BE SLOW TO MOVE OUT. BUT WITH SUCH UNCERTAINTY WILL NOT TOUCH THAT FORECAST PERIOD YET. THURSDAY THROUGH SUNDAY...MEDIUM RANGE GUIDANCE TODAY HAS COME INTO A LITTLE BETTER AGREEMENT REGARDING THE OVERALL PATTERN EVOLUTION. BETTER CONSENSUS NOTED IN DEVELOPING A RATHER DEEP UPPER LOW ACROSS THE WESTERN CONUS LATE IN THE WEEK AND HEADING INTO THE WEEKEND... WHILE DOWNSTREAM RIDGING TAKES SHAPE OVER THE CENTRAL AND EASTERN U.S. GFS REMAINS THE STRONGEST WITH THIS IDEA COMPARED TO THE ECMWF EFFECTIVELY BLOCKING THE NORTHERN GREAT LAKES FROM ANY SIGNIFICANT WEATHER THROUGH THE PERIOD. ECMWF SOLUTION REMAINS A LITTLE LESS AMPLIFIED AND ALLOWS SOME SEMBLANCE OF A WEAK COLD FRONT TO SAG INTO THE NRN GREAT LAKES IN THE SAT-SUN TIMEFRAME. ECMWF SCENARIO BETTER SUPPORTED BY NCEP ENSEMBLE MEANS AS WELL AS HPC FORECAST GRAPHICS AND JUSTIFIES KEEPING THE LOW CHANCE FOR PRECIP DURING NEXT WEEKEND. OTHERWISE...AFTER A COOLER START TO THE WEEK TEMPERATURES EXPECTED TO REBOUND BACK TO OR SLIGHTLY ABOVE NORMALS FOR MID SEPTEMBER. ADAM && .APX...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 243 PM EDT SUN SEP 10 2006 .SHORT TERM (TONIGHT THROUGH MONDAY)... BASED ON RECENT SURFACE AND SATELLITE DATA IN CONJUNCTION WITH RECENT RUC, NAM, AND GFS MODEL SOLUTIONS, EXPECT THE DEVELOPMENT OF ISOLATED LIGHT RAIN SHOWERS ACROSS THE SOUTHERN PART OF THE UPPER OHIO VALLEY TO DIMINISH AFTER SUNSET. ACROSS THE NORTHERN PART, IT COULD STAY MAINLY CLOUDY TONIGHT DUE TO PERSISTENT STRATOCUMULUS. INSERTED MENTION OF PATCHY FOG MONDAY MORNING, BASED AS MUCH ON PERSISTENCE AND CLIMATOLOGY AS MODEL GUIDANCE. STRATOCUMULUS ACROSS THE NORTH WILL HELP WITH FOG DEVELOPMENT IF IT DISSIPATES EARLY TONIGHT, BUT PRECLUDE MUCH FOG DEVELOPMENT IF IT PERSISTS ALL NIGHT. REGARDING PRECIPITATION ONSET WITH APPROACHING MIDWEST LOW PRESSURE SYSTEM, LATEST GFS AND MORE SO LATEST NAM ARE SLOWER, SO HAVE ONLY SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS MONDAY AFTERNOON, THEN CHANCE STARTING EARLY MONDAY NIGHT. FOR TEMPERATURES, NOT MUCH CHANGE, IN CONCURRENCE WITH LATEST GFS AND NAM MOS VALUES. && .LONG TERM (MONDAY NIGHT THROUGH SUNDAY)... SYSTEM OVER THE MID MS VALLEY MONDAY NIGHT WILL MOVE SLOWLY NORTHEAST ACROSS THE GREAT LAKES TUESDAY AND WEDNESDAY. ASSOCIATED COLD FRONT EXPECTED TO PUSH THROUGH THE UPPER OHIO VALLEY REGION LATE WEDNESDAY. SO KEPT CHANCE POPS FOR SHOWERS/THUNDERSTORMS IN FORECAST MONDAY NIGHT AND TUESDAY...THEN BUMPED UP TO LIKELY TUESDAY NIGHT AND WEDNESDAY. STILL A CHANCE OF SHOWERS EARLY THURSDAY AS SYSTEM PULLS EAST. HIGH PRESSURE AT SURFACE AND ALOFT WILL BUILD INTO REGION LATE THURSDAY AND HOLD ON THROUGH THE WEEKEND BRINGING DRY CONDITIONS AND NEAR NORMAL TEMPERATURES. && .AVIATION... BASED ON RECENT SURFACE AND SATELLITE DATA ALONG WITH RECENT RUC AND NAM FORECAST SOUNDINGS, EXPECT STRATOCUMULUS CEILINGS IN MVFR RANGE TO PERSIST ACROSS THE NORTHERN PART OF THE UPPER OHIO VALLEY, AT LEAST INTO EARLY TONIGHT, AND POSSIBLY INTO MONDAY MORNING. FARTHER SOUTH, CUMULUS AND LOCALIZED VFR CEILINGS CAN DEVELOP THIS AFTERNOON INTO EARLY TONIGHT. PATCHY FOG WITH LOCALLY IFR VISIBILITIES CAN DEVELOP AGAIN MONDAY MORNING, MORE SO IF STRATOCUMULUS ACROSS NORTH DISSIPATES EARLY TONIGHT. WINDS WILL BE GENERALLY LESS THAN 7 KTS AND FROM A NORTHEASTERLY DIRECTION TONIGHT AND EASTERLY DIRECTION DAYTIME MONDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ pa