AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DENVER CO 300 PM MDT SUN JUL 31 2005 .SHORT TERM...SUBTROPICAL MOISTURE PLUME ROUNDING TOP OF HIGH PRESSURE RIDGE CENTERED OVER THE WEST-CENTRAL GREAT PLAINS QUITE NOTICEABLE ON LATEST WATER VAPOR SATELLITE IMAGERY. NWRN HALF OF THE FORECAST AREA PRETTY MUCH UNDER THIS MID-LAYER OF MOIST AND VERY UNSTABLE AIR ATTM. MEANWHILE THE LOWER ATMOSPHERE EAST OF THE MTNS HAS REMAINED DRY WITH SFC DEW POINTS IN THE MID AND UPPER 40S. AIRMASS EVEN DRIER ALONG AND SOUTH OF THE PALMER DIVIDE WHERE DEW POINTS ONLY IN THE 30S. WIDELY SCATTERED T-STORMS FORMING OVER THE MTNS AND FOOTHILLS THIS HOUR SHOULD CONTINUE TO DRIFT E/NEWRD OVER THE I-25 URBAN CORRIDOR THROUGH EARLY THIS EVENING. PLATTEVILLE PROFILER SHOWS ABOUT 10KTS OF 0-6 KM SHEAR AT THIS HOUR...BUT LOW LEVEL WINDS HAVE CONTINUED TO WEAKEN PAST COUPLE OF HOURS. LAPS AND RUC INDICATE SFC BASED CAPES IN THE 600-1200 J/KG RANGE IN LARIMER...WELD AND BOULDER COUNTIES...AND WITH MID-LEVEL LAPSE RATES EXCEEDING 8.5 C/KM AND TEMP-DEWPOINT SPREADS OF +40F...SMALL HAIL AND MARGINALLY SEVERE DOWNBURSTS A POSSIBILITY WITH HIGH BASED STORMS MOVING OFF THE NRN FRONT RANGE FOOTHILLS NEXT 3-4 HOURS. OTHERWISE STORMS SHOULD END IN ALL BUT THE FAR NERN PLAINS BY MIDNIGHT. WHEREAS ISOLATED RAIN SHOWERS MAY LINGER FOR MOST OF THE NIGHT IN THE N-CENTRAL MTNS WHERE THE ATMOSPHERE WILL REMAIN RELATIVELY MOIST AND UNSTABLE UNDER THE PLUME OF MID-LEVEL MOISTURE. MONDAY...LOOKS TO BE ABOUT A CARBON COPY OF TODAY...ALTHOUGH A SFC FRONTAL BOUNDARY LYING ACROSS NERN WY AND WRN NE TONIGHT...IS FORECAST TO SAG SOUTHWESTWARD ACROSS THE NERN PLAINS OF CO DURING THE DAY. DOESN/T LOOK ALL THAT SIGNIFICANT...ALTHOUGH MODELS SHOW NELY LOW LEVEL FLOW DEEPENING ACROSS THE NERN PLAINS DURING THE AFTERNOON WITH CYCLOGENESIS OVER THE PALMER DIVIDE. THETA-E FIELDS SHOW LOW-LEVEL MOISTURE POOLING UP ALONG THE FRONT RANGE FOOTHILLS DURING THE AFTERNOON CAUSING SFC BASED CAPE VALUES TO RISE TO AROUND 2000 J/KG BY 00Z/TUE. SHOULD SEE BULK OF ANY CONVECTION/T-STORM ACTIVITY ONCE AGAIN BENEATH THE SUBTROPICAL MOISTURE PLUME DRAPED ACROSS THE NRN AND NWRN HALF OF THE FORECAST AREA. TEMPS TOMORROW SHOULD BE ABOUT THE SAME AS THOSE TODAY. .LONG TERM...MON NGT-WED...A PERSISTENT UPR RDG OVR THE CNTRL RCKYS WILL KEEP THE AIR MASS SUBSIDENT. HWVR THE CIRC ARND THE UPR RDG WILL CONT TO ENTRAIN TROPICAL MOISTURE FM MEXICO AND SPRD IT NWD INTO THE AREA. ADEQUATE INSTABILITY WILL BE PRESENT FOR ISOLD TO SCT SHWRS AND TSTMS MAINLY DURING EACH AFTN AND EVE. A SURGE OF HI PRES MOVG SWD ON THE PLAINS WED WILL COOL THE AIR MASS SUM AND PSBLY PROVIDE BOUNDARIES FOR ENHANCED TSTM DVLPMNT. TEMPS WILL GENLY BE A SMIDGEN WARMER THAN MOS TEMP GUIDANCE VALUES WUD SUGGEST. IN EXTENDED PRD...THU-SUN...MDLS MAINTAIN UPR RDG OVR CNTRL RCKYS. GFS CONTS TO SHW PLUME OF MONSOONAL MSTR OVR AREA BFR DRIER AMS ON NWLY FLO ALF SHUNTS PLUME FARTHER TO S BY SUN. SURGE OF HI PRES OVR PLAINS ON THU AND FRI SHUD ENHANCE PCPN. WILL RAISE POPS TO CHC ON BOTH DAYS. TEMPS WILL BE NR SEASONAL NORMS EXCEPT A LTL COOLER ON THU AND FRI ON PLAINS. && .BOU...NONE. && $$ BAKER/GARD...WFO BOULDER co AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE GOODLAND KS 752 PM MDT SUN JUL 31 2005 .UPDATE...MOIST EAST/NORTHEAST FLOW NORTH OF THE SURFACE TROUGH AXIS WILL ALLOW SURFACE MOISTURE TO ADVECT SLOWLY WEST/SOUTHWEST AND KEEP TEMPERATURES UP ALONG AND NORTH OF THE BOUNDARY WHICH WILL SINK SLOWLY SOUTH THROUGH THE OVERNIGHT HOURS. THEREFORE...RAISED MINIMUM TEMPEARTURES A CATEGORY OR SO MAINLY IN THE EAST. KEPT A SLIGHT CHANCE MENTION ACROSS THE NORTH AS EVENING CONVECTION ACROSS NORTHEAST COLORADO SLOWLY BUILDS EASTWARD INTO INSTABILITY AXIS NORTH OF SURFACE TROUGH AXIS. MWM && .PREV DISCUSSION... (ISSUED 225 PM MDT SUN JUL 31 2005) DISCUSSION...FORECAST PROBLEMS WILL BE CHANCE OF PRECIPITATION WITH WEAK WAVES/PESKY SURFACE BOUNDARY AND HOW WARM TO MAKE THE MAXES. SATELLITE SHOWING FLOW REMAINING RELATIVELY UNCHANGED WITH A SLIGHT TENDENCY TO BECOME MORE AMPLIFIED WITH TIME. POWERFUL UPPER TROUGH IS STARTING TO ESTABLISH ITSELF AS IT DIGS TOWARD THE EASTERN PACIFIC. FLOW IS BECOMING MORE BLOCKY OVER THE WESTERN ATLANTIC AS WELL. NUMBER OF SHORT-WAVES ROTATING AROUND THE 500 MB RIDGE. ONE IS ROTATING THROUGH IDAHO AND NORTHERN UTAH WITH THE NEXT ONE MOVING ACROSS CALIFORNIA. THESE LOOK TO BE FAIRLY STRONG WAVES. AT 700 MB... WAVE IS STUCK IN THE RIDGE OVER EASTERN COLORADO. WEAK BOUNDARY IS DRAPED OVER THE FORECAST AREA AT THIS TIME AND DIVIDES AREA INTO NORTHWEST AND SOUTHEAST HALVES. AIR MASS DRIES TO THE NORTHWEST OF THIS BOUNDARY WITH THE AIR MASS ABOVE IT COOLER AND MORE MOIST THAN YESTERDAY. AT MID LEVELS...MODELS ARE NOT MOIST ENOUGH WITH THE MOISTURE PLUME ON THE WESTERN EDGE OF THE UPPER RIDGE. OVERALL...ESPECIALLY OVER THE OCEANS...THE UKMET/ECMWF LOOK TO BE DOING THE BEST. RUC IS CAPTURING SHORTWAVE DETAILS VERY WELL FOLLOWED BY THE UKMET/GFS. MODELS DID NOT HAVE HEIGHTS HIGH ENOUGH WITH THE GFS/RUC DOING A LITTLE BETTER THAN THE UKMET/ECMWF. AT LOW LEVELS...RUC DOING BETTER INITIALLY ON THE WIND FIELD WITH THE UKMET DOING SLIGHTLY BETTER THAN THE NAM. ECMWF/UKMET/GFS DID BETTER ON THE 850 MB TEMPERATURES. FOR THE MOST PART...WILL GO WITH A BLEND OF RUC/GFS/UKMET FOR THIS FORECAST. TONIGHT...ABOVE MENTIONED BOUNDARY LOOKS TO BE THE FOCUS FOR PRECIPITATION CHANCES. MET/NAM HAVE DRIED OUT CONSIDERABLE FROM RECENT RUNS. RUC IS DOING VERY WELL WITH INCOMING SHORTWAVE AND GFS IS VERY MUCH LIKE IT. LOW LEVEL CONVERGENCE FIELDS AND MID LEVEL LIFT WOULD SUPPORT A SLIGHT CHANCE OF THUNDERSTORMS OVER THE NORTHERN COUNTIES AND THEN CURVING DOWN INTO THE SOUTHEAST THREE. SOUNDINGS SHOW DRY LOW LEVELS ALTHOUGH A LITTLE MORE MOIST THAN YESTERDAY. SO IF ANYTHING DOES FALL IT WILL NOT BE A LOT. MONDAY/MONDAY NIGHT...BOUNDARY HANGS AROUND MAINLY OVER THE NORTHWEST SECTION. ORIENTATION OF UPPER RIDGE AND SHORTWAVE ENERGY AND MID LEVEL MOISTURE ALONG WITH LOW LEVEL CONVERGENCE WOULD SUPPORT HAVING A SLIGHT CHANCE DURING THE NIGHT IN THE NORTHWEST CORNER. WILL TEND TO FOLLOW THE WARMER GUIDANCE ESPECIALLY FURTHER SOUTH AND EAST THAT YOU GO. TUESDAY/TUESDAY NIGHT...THIS PERIOD VERY MUCH LIKE THE PREVIOUS IN ALL ASPECTS. WILL ONCE AGAIN PUT IN A SLIGHT CHANCE DURING THE NIGHT IN THE NORTHWEST CORNER. WILL ALSO TEND TO GO TOWARD THE WARMER GUIDANCE. WEDNESDAY...NEW GUIDANCE HAS WARMED UP MAXES FOR THIS DAY AS APPROACHING FRONT HAS SLOWED. BASED ON UPPER RIDGE POSITION WOULD AGREE WITH THAT. SO WITH SLOWER FRONTAL PASSAGE WILL GO WARMER AND DRIER. FOR THURSDAY THROUGH SUNDAY...NOT TOO MUCH DIFFERENCE FROM PREVIOUS MODEL RUN AND BETWEEN THE MODELS. HOWEVER SOME SUBTLE DIFFERENCES BETWEEN THE ECMWF/GFS AND FROM THEIR PREVIOUS RUNS. GFS INCREASES THE HEIGHTS RIDGE OVER THE AREA FROM THE PREVIOUS RUN. ALSO IT HAS HIGHER HEIGHTS OVER US PLUS HAS RIDGE CENTER FURTHER WEST THAN ECMWF. CONSIDERING CURRENT FLOW PATTERN AND MAIN STORM TRACK FURTHER NORTH...LIKE THE GFS A LITTLE BETTER. THEN TOWARD THE END OF THE PERIOD MODELS REVERSE ROLES WITH THE ECMWF HOLDING ON TO HIGHER HEIGHTS OVER THE GFS AND PREFER THAT PER PREVIOUS REASONING. THEREFORE...WILL GO MORE GFS EARLY THEN ECMWF LATER. NOW TO THE DETAILS. WILL KEEP MENTION OF PRECIPITATION WEDNESDAY NIGHT WITH FRONTAL PASSAGE AND SHORTWAVE. THE ECMWF IS A LITTLE SLOWER AND WOULD AGREE WITH THIS BECAUSE OF UPPER RIDGING. THIS COULD KEEP SOME PRECIPITATION INTO EARLY THURSDAY. WAS INITIALLY WANTING TO LOWER POPS. HOWEVER...NEIGHBORS HAVE SLIGHT CHANCE TO CHANCE. HOWEVER...CONSIDERING THAT FRONT COULD BE EVEN SLOWER WITH SHORTWAVE ENERGY...WILL KEEP SOME MENTION IN FOR NOW. FRIDAY AFTERNOON AND EVENING LOOK A LITTLE MORE INTERESTING. RETURN FLOW DEVELOPS AS SURFACE RIDGE PULLS AWAY. ALSO HAVE WEAK NORTHWEST FLOW ALOFT WITH AN EMBEDDED SHORTWAVE. MIDDLE LEVELS MOISTEN UP AS WELL. HOWEVER...THESE SUBTLE DETAILS WILL CHANGE MANY TIMES BEFORE THEN. PLUS IF WEDNESDAY NIGHT/THURSDAY FRONT IS SLOWER...THE ABOVE SCENARIO WILL ALSO GET PUSHED BACK. WILL KEEP FRIDAY DRY FOR NOW... AND LET LATER SHIFTS KEEP THEIR EYE ON THIS PERIOD. THEN RIDGE BUILDS IN PER ECMWF WITH GFS BREAKING DOWN RIDGE TOO MUCH. RIDGE NOT ONLY BUILDS BUT ELONGATES TO THE WEST WHICH SHOULD SHUT OFF ANY SUBTROPICAL MOISTURE. THEREFORE...WILL KEEP SATURDAY AND SUNDAY DRY. MEX/GFS WARMER THAN PREVIOUS RUNS. WILL PROBABLY NOT CHANGE TEMPERATURES TOO MUCH BUT TEND TO GO NEAR TO ABOVE GUIDANCE. && .GLD WATCHES/WARNINGS/ADVISORIES... .KS...NONE. .NE...NONE. .CO...NONE. && $$ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 225 PM MDT SUN JUL 31 2005 .DISCUSSION...FORECAST PROBLEMS WILL BE CHANCE OF PRECIPITATION WITH WEAK WAVES/PESKY SURFACE BOUNDARY AND HOW WARM TO MAKE THE MAXES. SATELLITE SHOWING FLOW REMAINING RELATIVELY UNCHANGED WITH A SLIGHT TENDENCY TO BECOME MORE AMPLIFIED WITH TIME. POWERFUL UPPER TROUGH IS STARTING TO ESTABLISH ITSELF AS IT DIGS TOWARD THE EASTERN PACIFIC. FLOW IS BECOMING MORE BLOCKY OVER THE WESTERN ATLANTIC AS WELL. NUMBER OF SHORTWAVES ROTATING AROUND THE 500 MB RIDGE. ONE IS ROTATING THROUGH IDAHO AND NORTHERN UTAH WITH THE NEXT ONE MOVING ACROSS CALIFORNIA. THESE LOOK TO BE FAIRLY STRONG WAVES. AT 700 MB... WAVE IS STUCK IN THE RIDGE OVER EASTERN COLORADO. WEAK BOUNDARY IS DRAPED OVER THE FORECAST AREA AT THIS TIME AND DIVIDES AREA INTO NORTHWEST AND SOUTHEAST HALVES. AIR MASS DRIES TO THE NORTHWEST OF THIS BOUNDARY WITH THE AIR MASS ABOVE IT COOLER AND MORE MOIST THAN YESTERDAY. AT MID LEVELS...MODELS ARE NOT MOIST ENOUGH WITH THE MOISTURE PLUME ON THE WESTERN EDGE OF THE UPPER RIDGE. OVERALL...ESPECIALLY OVER THE OCEANS...THE UKMET/ECMWF LOOK TO BE DOING THE BEST. RUC IS CAPTURING SHORTWAVE DETAILS VERY WELL FOLLOWED BY THE UKMET/GFS. MODELS DID NOT HAVE HEIGHTS HIGH ENOUGH WITH THE GFS/RUC DOING A LITTLE BETTER THAN THE UKMET/ECMWF. AT LOW LEVELS...RUC DOING BETTER INITIALLY ON THE WIND FIELD WITH THE UKMET DOING SLIGHTLY BETTER THAN THE NAM. ECMWF/UKMET/GFS DID BETTER ON THE 850 MB TEMPERATURES. FOR THE MOST PART...WILL GO WITH A BLEND OF RUC/GFS/UKMET FOR THIS FORECAST. TONIGHT...ABOVE MENTIONED BOUNDARY LOOKS TO BE THE FOCUS FOR PRECIPITATION CHANCES. MET/NAM HAVE DRIED OUT CONSIDERABLE FROM RECENT RUNS. RUC IS DOING VERY WELL WITH INCOMING SHORTWAVE AND GFS IS VERY MUCH LIKE IT. LOW LEVEL CONVERGENCE FIELDS AND MID LEVEL LIFT WOULD SUPPORT A SLIGHT CHANCE OF THUNDERSTORMS OVER THE NORTHERN COUNTIES AND THEN CURVING DOWN INTO THE SOUTHEAST THREE. SOUNDINGS SHOW DRY LOW LEVELS ALTHOUGH A LITTLE MORE MOIST THAN YESTERDAY. SO IF ANYTHING DOES FALL IT WILL NOT BE A LOT. MONDAY/MONDAY NIGHT...BOUNDARY HANGS AROUND MAINLY OVER THE NORTHWEST SECTION. ORIENTATION OF UPPER RIDGE AND SHORTWAVE ENERGY AND MID LEVEL MOISTURE ALONG WITH LOW LEVEL CONVERGENCE WOULD SUPPORT HAVING A SLIGHT CHANCE DURING THE NIGHT IN THE NORTHWEST CORNER. WILL TEND TO FOLLOW THE WARMER GUIDANCE ESPECIALLY FURTHER SOUTH AND EAST THAT YOU GO. TUESDAY/TUESDAY NIGHT...THIS PERIOD VERY MUCH LIKE THE PREVIOUS IN ALL ASPECTS. WILL ONCE AGAIN PUT IN A SLIGHT CHANCE DURING THE NIGHT IN THE NORTHWEST CORNER. WILL ALSO TEND TO GO TOWARD THE WARMER GUIDANCE. WEDNESDAY...NEW GUIDANCE HAS WARMED UP MAXES FOR THIS DAY AS APPROACHING FRONT HAS SLOWED. BASED ON UPPER RIDGE POSITION WOULD AGREE WITH THAT. SO WITH SLOWER FRONTAL PASSAGE WILL GO WARMER AND DRIER. FOR THURSDAY THROUGH SUNDAY...NOT TOO MUCH DIFFERENCE FROM PREVIOUS MODEL RUN AND BETWEEN THE MODELS. HOWEVER SOME SUBTLE DIFFERENCES BETWEEN THE ECMWF/GFS AND FROM THEIR PREVIOUS RUNS. GFS INCREASES THE HEIGHTS RIDGE OVER THE AREA FROM THE PREVIOUS RUN. ALSO IT HAS HIGHER HEIGHTS OVER US PLUS HAS RIDGE CENTER FURTHER WEST THAN ECMWF. CONSIDERING CURRENT FLOW PATTERN AND MAIN STORM TRACK FURTHER NORTH...LIKE THE GFS A LITTLE BETTER. THEN TOWARD THE END OF THE PERIOD MODELS REVERSE ROLES WITH THE ECMWF HOLDING ON TO HIGHER HEIGHTS OVER THE GFS AND PREFER THAT PER PREVIOUS REASONING. THEREFORE...WILL GO MORE GFS EARLY THEN ECMWF LATER. NOW TO THE DETAILS. WILL KEEP MENTION OF PRECIPITATION WEDNESDAY NIGHT WITH FRONTAL PASSAGE AND SHORTWAVE. THE ECMWF IS A LITTLE SLOWER AND WOULD AGREE WITH THIS BECAUSE OF UPPER RIDGING. THIS COULD KEEP SOME PRECIPITATION INTO EARLY THURSDAY. WAS INITIALLY WANTING TO LOWER POPS. HOWEVER...NEIGHBORS HAVE SLIGHT CHANCE TO CHANCE. HOWEVER...CONSIDERING THAT FRONT COULD BE EVEN SLOWER WITH SHORTWAVE ENERGY...WILL KEEP SOME MENTION IN FOR NOW. FRIDAY AFTERNOON AND EVENING LOOK A LITTLE MORE INTERESTING. RETURN FLOW DEVELOPS AS SURFACE RIDGE PULLS AWAY. ALSO HAVE WEAK NORTHWEST FLOW ALOFT WITH AN EMBEDDED SHORTWAVE. MIDDLE LEVELS MOISTEN UP AS WELL. HOWEVER...THESE SUBTLE DETAILS WILL CHANGE MANY TIMES BEFORE THEN. PLUS IF WEDNESDAY NIGHT/THURSDAY FRONT IS SLOWER...THE ABOVE SCENARIO WILL ALSO GET PUSHED BACK. WILL KEEP FRIDAY DRY FOR NOW... AND LET LATER SHIFTS KEEP THEIR EYE ON THIS PERIOD. THEN RIDGE BUILDS IN PER ECMWF WITH GFS BREAKING DOWN RIGDE TOO MUCH. RIDGE NOT ONLY BUILDS BUT ELONGATES TO THE WEST WHICH SHOULD SHUT OFF ANY SUBTROPIPCAL MOISTURE. THEREFORE...WILL KEEP SATURDAY AND SUNDAY DRY. MEX/GFS WARMER THAN PREVIOUS RUNS. WILL PROBABLY NOT CHANGE TEMPERATURES TOO MUCH BUT TEND TO GO NEAR TO ABOVE GUIDANCE. && .GLD WATCHES/WARNINGS/ADVISORIES... .KS...NONE. .NE...NONE. .CO...NONE. && $$ BULLER ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1200 AM EDT SUN JUL 31 2005 .DISCUSSION... LATE UPDATE AS RESULT OF SVR CONVECTION LATE THIS EVENING. WEAK SHORTWAVE MOVING DOWN FROM NW OF LAKE SUPERIOR ALONG WITH WEAK WAA AT 850 MB ENOUGH TO FINALLY ERODE WEAK MID LVL CAP THIS EVENING. THE RESULTING CONVECTION HAS BECOME STRONG TO SEVERE ACROSS PORTIONS OF UPR MI THIS EVENING AS RUC/LAPS DATA INDICATES ELEVATED CAPES OF 2000-2500 J/KG WITH 0-6 KM BULK SHEAR 35-40KT. ALTHOUGH SHEAR PROFILES FAVOR MOSTLY MULTICELL SVR THERE IS A POTENTIAL FOR ISOLATED SUPERCELLS WITH BOTH HAIL AND WIND AS SVR THREATS. WET-BULB ZERO HEIGHTS ARE AROUND 12KFT. LOOK FOR CONVECTION TO GENERALLY END BY 09Z AS DNVA AS SHORTWAVE SLIDES SE OF THE AREA AND DNVA AND RDGG REPLACES IT FROM THE WEST. TEMPS GENERALLY LOOKED GOOD SO NO CHANGES MADE THERE. && .MQT...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ VOSS mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 335 PM EDT SUN JUL 31 2005 .DISCUSSION... LARGE SCALE PATTERN HAS A H5 RIDGE WITH 596 DAM HEIGHTS CENTERED OVER CNTRL PLAINS POKING INTO MONTANA AND SASKATCHEWAN. STRONGER MID LEVEL WINDS GENERALLY ALONG US/CANADIAN BORDER FM TROUGH OFF PAC NW (NEXT SIG WX MAKER MID WEEK) INTO CNTRL SASKATCHEWAN/MANITOBA AND SE INTO THE UPR LAKES AND NEW ENGLAND. SHORTWAVE WITHIN THIS FLOW IS SLIDING INTO NCNTRL LK SUPERIOR. MID LEVEL WIND SPEEDS ON SOUTHERN FRINGE OF SHORTWAVE INTO UPR MI GENERALLY 30-40KT PER 12Z INL RAOB AND RUC. SFC FLOW OVER CWA IS MAINLY FM SW ALTHOUGH WINDS RIGHT ALONG LK SUPERIOR ARE TRYING TO BECOME ONSHORE...DUE TO DAYTIME HEATING AND WHAT MAY BE AN OUTFLOW FROM EARLIER CONVECTION AS SHOWN BY THE W LK SUPERIOR BUOY SHOWING A NNE WIND. ALTLHOUGH MUCAPE VALUES ARE QUITE HIGH 1500-2000J/KG PER RUC THE 17Z TAMDAR SOUNDINGS FM CMX AND SAW ARE VERY CAPPED AND OTHER THAN A THIN LAYER OF MOISTURE AROUND H85...VERY DRY. THE SOUNDINGS INDICATE WE WOULD NEED TO ACHIEVE TEMPS NEAR 90F TO BREAK THE CAP AND GET CONVECTION TO FIRE. SO FAR...TEMPS ARE STRUGGLING INTO THE LOW-MID 80S DUE TO LEFTOVER AC/CI BLOWOFF FROM CONVECTION THAT WAS OVR NW LK SUPERIOR EARLIER. THUS FAR...ONLY A FEW SUB 40 DBZ BLIPS ON RADAR E OF MARQUETTE (DEVELOPED IN LK SUPERIOR BREEZE CONVERGENCE ZONE OFFSHORE OF ALGER CO) WHILE MORE VIGOROUS CONVECTION IS DEVELOPING FAR SE OF HERE OVR FAR NE LWR MI WHERE 18Z SOUNDING FM APX INDICATED MORE MOISTURE IN H85-H75 LAYER AND LESS CAPPING. IT IS FEASIBLE THAT MOST CWA MAY END UP NOT SEEING ANY CONVECTION THIS EVENING INTO THE OVERNIGHT AS DRY AIR ABOVE H85 ON THE TAMDAR SOUNDINGS AND BACK INTO MN AHEAD OF TROUGH MAY END UP TOO TOUGH TO OVERCOME. HOWEVER...PRESENCE OF H85 THETA-E ADVECTION NOSING INTO SW UPR MI WITH SFC TD NEAR 70F IN THAT AREA...AND BLYR CONVERGENCE DUE TO WIND OFF LK SUPERIOR MAY STILL HELP POP SOME CONVECTION...IF TEMPS CAN REACH UPR 80S BTWN 4 AND 6 PM THIS AFTN. 0-6KM SHEAR BTWN 30-40KT COULD SUPPORT SUPERCELLS IF STORMS WOULD DEVELOP DUE TO THE HIGH INSTABILITY. WILL CARRY A SLIGHT CHANCE FOR APPROX THE WEST HALF OF CWA WITH A 30 POP INTO THE E WHERE THE RADAR RETURNS ARE PRESENT AND A BIT MORE MOISTURE IS PRESENT IN THE H85-H75 LAYER. NAM INDICATES MOST CONVECTION WOULD DEVELOP OVERNIGHT OVR SCNTRL ZONES. TROUBLE IS PRIMARY AXIS OF LLJ IS ORIENTED FM W TO E INTO N LWR MI...AND THINK THIS IS WHERE BETTER CHANCE OF PCPN WOULD BE. WILL INCLUDE A SLIGHT CHANCE OVERNIGHT FM ROUGHLY IMT TO ERY IN CASE THIS ELEVATED CONVECTION WOULD FORM SLIGHTLY FARTHER N. IN ANY CASE...ALL CONVECTION SHOULD EXIT THE CWA BY DAYBREAK MON AS HIGH PRES OVR SCNTRL CANADA BRIEFLY BUILDS INTO AREA. DESPITE SOME HIGH CAPE VALUES PROGGED BTWN 500-2000J/KG (GREATEST S CNTRL) ON MON...IT SEEMS LIKE MINIMAL LOW LEVEL CONVERGENCE AND ANTICYCLONIC FLOW WITH FLOW OFF LK SUPERIOR WILL DETER PCPN. TEMPS...NOT A TREMENDOUS COOL DOWN WITH H85 TEMPS DROPPING TO ONLY AROUND +18C...SO INLAND AREAS BACK INTO THE UPR 80S SEEM LIKELY...SLIGHTLY COOLER TEMPS AROUND 80 NEAR LK SUPERIOR. LIKELY WILL BE STILL STUFFY AS DEWPOINTS ARE VERY SLOW TO FALL OFF WAY UPSTREAM INTO S MANITOBA. TD SHOULD FALL OFF SOME MON NIGHT INTO 50S AS CENTER OF HIGH IS OVERHEAD. THIS HIGH PRES WILL SHIFT TO THE SE LATER MON NIGHT OPENING THE DOOR FOR ANOTHER VERY WARM DAY ON TUE AS SRLY FLOW RETURNS. H85 TEMPS RISE TOWARD +20C IN THE W HALF OF CWA BY LATE AFTN. RIDGE IS STILL CLOSE ENOUGH TO ALLOW BLYR WINDS TO REMAIN LESS THAN 10 KT FM S SO WILL PROBABLY SEE SOME LK BREEZES DEVELOP OFF LK SUPERIOR/MICHIGAN IN AFTN. CURRENT LOW TO MID 80S NEAR THE SHORE AND UPR 80S TO AROUND 90 INLAND LOOKS FINE. WARM AIR ADVECTION RETURN FLOW DEVLOPS LATER TUE NIGHT AS A TROUGH BEGINS TO ENCROACH ON FAR N PLAINS. SW H85 JET TO 30 KT AND H85-H7 LAPSE RATES NEAR 7.0C/KM MAY SUPPORT SCT ELEVATED CONVECTION LATE TUE NIGHT OVR ECNTRL MN/W CNTRL WI AND PERHAPS INTO FAR SW UPR MI. NAM QUITE ENTHUSIASTIC WITH THE IDEA WHILE GFS KEEPS TIGHTER H85 GRADIANT FAR ENOUGH SW TO KEEP POPS OUT OF CWA. CANADIAN GLOBAL SHOWS NO QPF. NO POPS ATTM...BUT DID INCREASE SKY COVER ALONG BORDER LATE TUE INTO WED AM. .EXTENDED...GOOD MODEL CONSISTENCY AND AGREEMENT WITH CURRENT PATTERN FOR THE WED-SUN PERIOD. EXPECT TROUGH OFFSHORE OF PAC NW COAST TO PRESS INTO SW CANADA MON-TUE AS STRONGER SHORTWAVE DROPPING ACROSS ALEUTIAN ISLANDS BUCKS THE LEAD SHORTWAVE EAST. MEDIUM RANGE MODELS INDICATE THE SHORTWAVE WILL MOVE EAST OVER THE S TIER OF CANADA THROUGH WED...THEN SLIGHTLY DIG INTO UPR LAKES THU/FRI. ALL MODELS CONSISTENT WITH IDEA WHICH IS PREFERRED BY HPC. UNTIL THE TROUGH ARRIVES WED NIGHT-THU...H85 TEMPS TOWARD 20C AND SW WINDS FM SFC-H85 SHOULD PUSH DAYTIME TEMPS TO AROUND 90F ON WED. BEST RAIN CHANCES THIS WEEK ARE TIED TO THE FRONTAL PASSAGE THU. AS MID SHIFT NOTED 00Z RUNS ARE FASTER WITH LEAD FRONT...PROGGING IT INTO CNTRL UPR MI AS EARLY AS 12Z THU. A SECONDARY FRONT WITH COOLER AIR MOVES THROUGH LATER THU INTO THU NIGHT. BEST CHANCE OF RAIN SHOULD BE DURING THIS TIME. UNTIL THE FRONT CROSSES THOUGH...TEMPS MAY RISE WELL INTO THE 80S EVEN ON THU...EXCEPT ON KEWEENAW WHERE WINDS SHIFTING TO THE NW WILL COOL THINGS SLIGHTLY. HUNG ON TO POPS INTO FAR E THROUGH MIDDAY FRI...THEN HIGH PRES AND DRY/COOLER WX BUILDS IN LATER FRI INTO SAT. 00Z GFS MORE AMPLIFIED WITH NEXT WAVE CROSSING SCNTRL CANADA SUN. WILL KEEP SUN DRY FOR NOW AS OTHER MODELS AND EXPERIMENTAL ENSEMBLES ARE NOT AS AMPLIFIED. SEEMS THAT BETTER CHANCES FOR PCPN WOULD BE VERY LATE SUN INTO SUN NIGHT SO WILL LEAVE FCST DRY. COORD WITH APX AND GRB...THANKS. && .MQT...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ JLA mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1141 AM EDT SUN JUL 31 2005 .DISCUSSION... THE MAIN CONCERN WITH THIS UPDATE IS THE POTENTIAL OF THUNDERSTORMS THIS AFTERNOON OVER THE FORECAST AREA. WATER VAPOR IMAGERY AND RUC/ETA SHOWING A RIDGE OVER THE SASKATCHEWAN...WITH WEAK SHORTWAVES SLIDING DOWN THE LEE OF THIS RIDGE. THE FIRST OF THE SHORTWAVES HAS MOVED OUT OF EASTERN U.P. INTO LAKE HURON...FOLLOWED BY ANOTHER SHORTWAVE OVER WESTERN ONTARIO. SURFACE ANALYSIS INDICATE A LOW OVER NORTH CENTRAL MINNESOTA WITH A WEAK WARM FRONT STRETCHING EAST ACROSS LAKE SUPERIOR AND DRAGGING A SURFACE TROUGH THROUGH SOUTHERN MINNESOTA. SCATTERED THUNDERSTORMS ARE FIRING OVER NORTHERN LAKE SUPERIOR IN AN AREA OF STRONG Q-VECTOR CONVERGENCE AND ALONG A THETA-E RIDGE. THE WEAK SHORTWAVE WILL MOVE THROUGH THE FORECAST AREA. THE NEXT SHORTWAVE WILL REMAIN OVER NORTHERN MINNESOTA. Q-VECTOR CONVERGENCE WILL BE MODERATE OVER THE FORECAST AREA THIS AFTERNOON. HOWEVER...THE LAPSE RATE WILL PRODUCE MUCAPE OF AROUND 3K-4K ACROSS THE FORECAST AREA. AN 850MB THETA-E RIDGE WILL ALSO STRETCH ACROSS THE FORECAST AREA. QPF FROM ETA12 IS SHOWING LITTLE OR NO PRECIPITATION WHEREAS RUC INDICATES HEAVY RAINS. I THINK RUC IS OVER DOING THE INSTABILITY AND RAINFALL. STILL CONDITION STILL LOOK QUESTIONABLE FOR THE CHANCES OF THUNDERSTORMS THIS AFTERNOON...IF CONVECTIVE TEMPERATURES ARE REACHED...THUNDERSTORMS WOULD DEVELOP AND SOME MAY BECOME SEVERE PRODUCING HIGH WINDS AND HAIL. && .MQT...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DLG mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 1128 AM EDT SUN JUL 31 2005 .UPDATED... I WILL DO A QUICK UPDATE TO PUT A SLIGHT CHANCE OF THUNDERSTORMS OVER THE NRN 1/2 OF THE CWA (NORTH OF INTERSTATE 96) THIS AFTERNOON. THE VISIBLE SATELLITE LOOP SHOWS AN OUT FLOW BOUNDARY DROPPING SOUTH FROM NRN WI TOWARD CNTRL LK MICHIGAN AN SHOULD GET TO LDM BTW 1 PM AND 2 PM. GIVEN THE STRENGTH OF THE SOUTHERLY FLOW ALREADY IN PLACE THERE AND THE RUC FORECAST OF 850 MB LI VALUES NEAR -2C ONE COULD NOT RULE OUT THE SLIGHT CHANCE A STORM COULD DEVELOP AND MOVE SOUTHEAST ALONG THE 1000/500MB THICKNESS GRADIENT. GIVEN THE RUC SHOWS THE LOW LEVEL JET STRENGTHENS TO 35 KNOTS OVER NRN LWR THIS AFTERNOON (PUTS THE GRR CWA IN DIVERGING LOW LEVEL WINDS)AND THE MOISTURE TRANSPORT VECTORS POINT TOWARD THE UPPER PENINSULA AND THE 700 TO 300 MB DPVA IS NEGATIVE (NVA OR DOWNWARD MOTION) IT IS A STRETCH BUT EVEN SO A SLIGHT CHANCES SEEMS GOOD TO ME. $$ .GRR WATCHES/WARNINGS/ADVISORIES...NONE. && $$ WDM mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DULUTH MN 247 PM CDT SUN JUL 31 2005 .DISCUSSION...FORECAST FOCUS IS ON THUNDERSTORM CHANCES...MAINLY TONIGHT...THEN EMPHASIS IS ON TEMPERATURES. ETA AND GFS ARE IN DECENT AGREEMENT...WITH THE ETA A BIT FASTER WITH FRONTAL MOVEMENT TONIGHT. GFS WAS FOLLOWED. THE SURFACE AND 850MB BOUNDARIES ARE NEARING OUR WESTERN ZONES THIS AFTERNOON...AS WINDS ARE VEERING TO WEST TO NORTHWEST AS SEEN IN SURFACE OBSERVATIONS AND AREA VWPS. CU FIELD DEVELOPING THIS AFTERNOON...BUT THUNDERSTORMS HAVE YET TO GET GOING. MODIFIED SOUNDINGS FROM GFS AND RUC SHOW SOME CONVECTIVE INHIBITION(CIN) AROUND 800MB. THERE IS PLENTY OF INSTABILITY...AS TEMPERATURES HAVE WARMED INTO THE 80S WITH A FEW 90S...AND DEWPOINTS ARE IN THE UPPER 60S TO LOWER 70S. MLCAPE IS 2000-2500J/KG AHEAD OF THE BOUNDARIES. LOWEST FEW THOUSAND FEET OFF OF MPX AND DLH VWP'S SHOW SOUTHWEST FLOW AROUND 25KT. WE WILL CONTINUE TO MENTION A SLIGHT CHANCE FOR THUNDERSTORMS TONIGHT WITH THE INSTABILITY AND LIFT ASSOCIATED WITH THE BOUNDARIES AND LOW LEVEL WARM AIR ADVECTION...BUT NOT GO TO HIGH WITH POP'S DUE TO THE CIN. IF STORMS DO GET GOING...SOME MAY BE SEVERE WITH 0-6KM SHEAR AROUND 30 KT AND THE HIGH MLCAPE'S. HIGH PRESSURE BUILDS IN TONIGHT...THEN SHIFTS EAST MONDAY NIGHT AND TUESDAY AS THE FLOW RETURNS OUT OF THE SOUTH AHEAD OF ANOTHER LOW PRESSURE SYSTEM. NEXT CHANCE FOR RAIN WILL COME TUESDAY NIGHT AS LOW LEVEL BOUNDARIES MOVE EAST AND LOW LEVEL JET INCREASES. TEMPERATURES WILL BE WARM OVER THE NEXT FEW DAYS...WITH MID 80S TO LOWER 90S ON MONDAY AND TUESDAY. WEDNESDAY SHOULD ALSO BE WARM AND WE INCREASED TEMPERATURES A FEW DEGREES OVER MOS. && .AVIATION...A FEW THUNDERSTORMS ARE POSSIBLE TONIGHT...MAINLY ALONG AND EAST OF A CRANE LAKE TO AITKIN LINE. BRIEF MVFR CONDITIONS WILL ACCOMPANY ANY STORMS. PATCHY FOG WITH IFR CONDITIONS ARE ALSO EXPECTED LATE TONIGHT INTO EARLY MONDAY MORNING...OTHERWISE VFR CONDITIONS CAN BE EXPECTED. .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. $$ MELDE mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON MS 333 PM CDT SUN JUL 31 2005 .DISCUSSION... IN THE SHORT TERM COULD NOT IMPROVE ON THE CURRENT FORECAST...SO VERY FEW CHANGES WERE MADE. FOR TONIGHT CONTINUED RAIN THROUGH THE EVENING. EXPECT SCATTERED SHOWERS TO CONTINUE FOR A FEW THIS EVENING...DID NOT WANT TO CUT THINGS OFF AT 00Z. RAISED TEMPS A DEGREE OR TWO INTO THE LOWER 70S. GENERALLY TRIED TO STICK TO GUIDANCE FOR POPS AND TEMPS. RUC ANALYSIS CONTINUES TO SHOW THE TROUGH AXIS STRETCHED ACROSS THE SOUTHEAST STATES. MODELS SHIFT THE AXIS WEST SLIGHTLY...BUT NO REAL MOVEMENT IS EXPECTED FOR THE NEXT DAY OR SO. THE EAST AND SOUTHERN PORTIONS OF THE CWA WILL BE THE FOCUS FOR SHOWER AND SOME THUNDERSTORM DEVELOPMENT THROUGH MONDAY. WINDS WERE WEAK ON ALL LEVELS...INSTABILITY ALSO REMAINS WEAK. PW VALUES WILL REMAIN AROUND 2 INCHES OR SLIGHTLY ABOVE...PERIODS OF HEAVY RAIN WILL BE THE MAIN CONCERN FOR THE NEXT FEW DAYS. FFG VALUES REMAIN IN THE 2-3 INCH PER HOUR RANGE...HOWEVER SHOWERS HAVE PRODUCED 1-2 INCH PER HOUR RAINFALL AMOUNTS WITH ISOLATED HIGHER AMOUNTS. WILL CONTINUE TO WATCH FOR FLASH FLOODING PROBLEMS IN THE URBANIZED AND POOR DRAINAGE AREAS...WITH RAINFALL EXPECTED TO BECOME MORE WIDESPREAD. CLOUDS KEPT A FEW LOCATIONS FROM WARMING TODAY...BUT MOST AREAS WERE NEAR 90...EXPECTING MORE OF THE SAME FOR MONDAY. KEPT TEMPS NEAR 90 FOR ALL GROUPS. MADE SOME ADJUSTMENTS TO THE CLOUDS TO MAKE ALL AREAS PARTLY CLOUDY INSTEAD OF MOSTLY CLOUDY OVERNIGHT. SOLID CLOUD DECK NEVER MOVE INTO THE AREA...SAW GENERAL AFTERNOON CU...WHICH SHOULD DISSIPATE OVERNIGHT AND COME BACK LATE MORNING. A FEW TWEAKS...BUT NO REAL CHANGES TO THE CURRENT FORECAST. LONG TERM...NOT A WHOLE LOT OF CHANGE FROM WHAT HAS BEEN ADVERTISED FOR THE TUE-THU TIME FRAME. UPPER LEVEL SHEAR AXIS AND THE SFC REFLECTION WILL KEEP DEEP MOISTURE (2 IN + PWS) OVER THE EASTERN HALF OF THE CWA. THE ONLY SLIGHT DIFFERENCE NOW IS THAT THE MODELS ARE HOLDING ONTO THE RIDGE OVER THE PLAINS. THIS UPPER RIDGE WILL ACTUALLY BUILD A LITTLE AND SHIFT EAST. AS THIS OCCURS THE UPPER SHEAR AXIS IS EXPECTED TO MOVE BACK TO THE SE US BY LATE WEEK INSTEAD OF RETROGRADING INTO TX. WHAT DOES ALL THIS MEAN? TUE-WED SHOULD REMAIN WELL ABOVE CLIMO WITH RESPECT TO POPS...ESPECIALLY EAST 1/2. THIS IS NO CHANGE FROM WHAT WE HAVE BEEN TALKING ABOUT FOR SEVERAL DAYS NOW. THU IS MORE OF A CHALLENGE AS THE BUILDING UPPER RIDGE RIDGE MAY KEEP THE CONVECTION SUPPRESSED IF IT MOVES IN FASTER. WHAT I HAVE DONE IS KEEP POPS GOING AS IS FOR THU AND STAYED WITH THE 00Z MEX GUIDANCE FOR ONE MORE PERIOD. WITH INCREASING CONFIDENCE THAT THE RIDGE WILL INFLUENCING OUR WX MORE ON FRI-SUN I HAVE STARTED A DRYING TREND AND HAVE BEGUN TO DROP BELOW GUIDANCE FOR POPS A BIT. AS FOR TEMPS...TUE-WED WILL BE SEVERAL DEGREES BELOW CLIMO DUE TO THE ACTIVE CONVECTION AND CLOUDS. I HAVE ONLY INCREASED MAX TEMPS A BIT FROM THE PREV FORECAST SO I WOULD NOT BE SO DIFFERENT FROM THE 12Z GUIDANCE. EITHER WAY...ALONG AND E OF THE MS RIVER WE WILL SEE HIGHS BETWEEN 88-90 WITH 90-92 W OF THE RIVER. LESS CLOUDS AND CONVECTIVE ACTIVITY WILL ALLOW FOR WARMER TEMPS THU-SUN. CURRENT FORECAST WAS RIGHT ON AN DIDN'T MAKE ANY ADJUSTMENTS. THE ONLY OTHER CHANGE I MADE WAS TO START A MORE CLIMO FAVORABLE SKY COVER TREND BEYOND THU. BASICALLY PARTLY CLOUDY DURING THE DAY AND MOSTLY CLEAR AT NIGHT. IF THE UPPER RIDGE WILL BE MOVING IN THE MID/UPPER LEVEL CLOUDS WILL NOT LINGER LIKE THEY HAVE BEEN. /CME/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 73 90 73 90 / 40 60 40 60 MERIDIAN 71 89 72 88 / 50 80 50 80 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ 07/36 ms AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO 530 PM CDT SUN JUL 31 2005 .DISCUSSION... I HAVE ADDED SOME SHOWER AND EMBEDDED THUNDERSTORMS TO THE EARLY EVENING FORECAST FOR THE KIRKSVILLE, MACON, AND LANCASTER AREAS IN NORTHEAST MISSOURI. WATER VAPOR IMAGERY AND LOCAL WIND PROFILERS INDICATE A PRONOUNCED VORTICITY MAXIMA MOVING THROUGH CENTRAL IOWA. RUC SOUNDINGS SUGGEST THAT MOISTURE AND INSTABILITY ARE ABOVE 700 MB. THE RUC SUGGESTS THAT AS THE SHORTWAVE IN IOWA DRIFTS SOUTHEAST THIS EVENING THETA-E ADVECTION AT THE 700 MB LEVEL WILL DIMINISH, AND I WOULD ANTICIPATE A DECREASE IN CONVECTIVE ACTIVITY AFTER 02 OR 03 UTC. KOCH && .PREVIOUS DISCUSSION... 214 PM... VORT MAX OVER SOUTHERN IOWA CONTINUES TO GENERATE WIDELY SCATTERED ELEVATED CONVECTION ACROSS NORTHERN MISSOURI THIS AFTERNOON. ANTICIPATE THIS ACTIVITY TO CONTINUE WEAKENING DURING THE LATE AFTERNOON HOURS AS THE MAIN SHORTWAVE ENERGY SHIFTS TO THE EAST. OTHERWISE...UPPER LEVEL RIDGING WILL CONTINUE TO INFLUENCE THE WESTERN HALF OF THE NATION THROUGH THE FIRST PART OF THE UPCOMING WEEK. CANNOT ENTIRELY RULE OUT A FLEETING CHANCE AT PRECIPITATION OVER THE NEXT COUPLE OF DAYS AS WEAK WAVES TOP THE UPPER RIDGE...ALTHOUGH BOTH NAM AND GFS SOLUTIONS KEEP THE MINOR IMPULSES OUTSIDE OF THE FORECAST AREA. HAVE ONLY MADE MINOR TWEAKS TO TEMPERATURES...WITH AN ABOVE NORMAL REGIME CONTINUING. FOR THE MIDDLE OF THIS WORK WEEK AND THROUGH THE WEEKEND THE GENERAL PATTERN WILL UNDERGO A BIT OF A CHANGE AS THE DOMINATE RIDGE IS PUSHED BACK TO THE WEST BY SEVERAL TROUGHS MOVING THROUGH CANADA. THE FIRST WAVE WILL PUSH THROUGH TOWARDS THE HUDSON BAY THURSDAY...PUSHING A COLD FRONT SOUTH INTO KANSAS AND MISSOURI THURSDAY NIGHT. GIVEN HOW FAR NORTH THIS SYSTEM IS...THE COLD POOL PUSH BEHIND THE FRONT SHOULD BE FAIRLY WEAK. MID RANGE MODELS SEEM TO AGREE ON THIS AS THEY DISPLAY THE BAROCLINICITY DECREASING ALONG THE TRAILING EDGE OF THE FRONT THAT IS PROGGED TO SINK INTO OUR AREA. HOWEVER...STILL THINK THE TAIL OF THE FRONT SHOULD HAVE ENOUGH FORCING TO WARRANT CHANCE POPS AS IT MOVES THROUGH THURSDAY NIGHT. TEMPERATURES SHOULD MODERATE INTO THE 80S FOR FRIDAY AND SATURDAY...RANGING AT OR JUST BELOW NORMAL. NEXT TROUGH TO MOVE THROUGH CANADA IS CURRENTLY PROGGED TO TRACK A LITTLE FARTHER SOUTH...POSSIBLY GIVING US ANOTHER CHANCE FOR RAIN ON THE OTHER SIDE OF NEXT WEEKEND. SCHMIT/CUTTER && 210 AM CDT SUN... UPPER LEVEL RIDGE TO REMAIN NEARLY STATIONARY THE NEXT COUPLE OF DAYS WITH ONLY CONCERN BEING ANY SHORTWAVE TOPPING THE RIDGE AND MOVING SE ACROSS MO. THE FIRST CONCERN IS THIS MORNING. NAM/GFS SEEM TO BE FALSELY INITIALIZING A SHORTWAVE IN NRN IOWA WITH THE MODELS SHIFTING THE SHORTWAVE SE INTO NERN MO THIS MORNING. REGARDLESS...SCATTERED CONVECTION HAS DEVELOPED ACROSS CENTRAL AND WEST CENTRAL IOWA IN AN AREA OF ISENTROPIC LIFT ON THE 305-310K SURFACE. THIS AREA IS ALONG A STRONG GRADIENT OF STEEP MID LEVEL LAPSE RATES. THE CONVECTION HAS BEEN SHIFTING SLOWLY ESE. HOWEVER...THE NAM SUGGEST THAT THE ISENTROPIC LIFT SHOULD MAINLY BE CONFINED TO THE NORTH OF THE CWA THIS MORNING. ONLY WEAK ISENTROPIC LIFT ON THE 310K SURFACE IS NOTED NEAR THE IOWA BORDER. GIVEN THE CURRENT TREND...CANNOT RULE OUT A FEW SHOWERS OR THUNDERSTORMS CROSSING THE IOWA BORDER THIS MORNING. THE STORMS SHOULD BE RATHER WEAK AS THE INSTABILITY IS CONFINED TO THE MID LEVELS. AS THE ISENTROPIC LIFTS DIMINISHES TO OUR NORTH LATER THIS MORNING...THE MID CLOUDS WILL RAPIDLY DISSIPATE AS THEY STREAM SOUTH...THEREFORE TEMPERATURES SHOULD HAVE NO PROBLEM REACHING THE LEVELS ACHIEVED YESTERDAY. STEEP MID LEVEL LAPSE RATES WILL CONTINUE THROUGH MONDAY. WILL LIKELY SEE AC DEVELOPMENT AGAIN TONIGHT TO THE NORTH AND WEST OF THE CWA AS WEAK SHORTWAVES ROUND THE RIDGE. ISENTROPIC LIFT CONSIDERABLY WEAKER SUNDAY NIGHT TO OUR NORTH. THEREFORE...SEE LESS POTENTIAL FOR CONVECTIVE DEVELOPMENT TO SAG SOUTHEAST INTO NWRN MO. OTHERWISE...HAVE MADE LITTLE DAY TO DAY CHANGE IN AFTN TEMPS THROUGH MONDAY AS H8 TEMPERATURES STAY RELATIVELY STEADY. HAVE MADE MINOR CHANGES IN THE EXTENDED AS PER REQUEST OF NEIGHBORING OFFICES. GFS A LITTLE QUICKER WITH THE COLD FRONT ON THURSDAY. HAVE ADJUSTED CLOUDS...WINDS...TEMPERATURES AND POPS A LITTLE TO FIT NEW TIMING. DB && .EAX WATCHES/WARNINGS/ADVISORIES... KS...NONE. MO...NONE. $$ WFO EAX mo AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE BUFFALO NY 1015 PM EDT SUN JUL 31 2005 .UPDATE... MAY HAVE TO MAKE A FAIRLY BIG CHANGE TO THE FIRST PERIOD CONTINUITY AS AN MCS HAS DEVELOPED OVER THE BRUCE PENINSULA OF SOUTHERN ONTARIO DURING THE PAST HOUR. CLOUD TOPS ARE COOLING AND CLOUD TO GROUND LIGHTNING STRIKES REMAIN IMPRESSIVE WITH THE FEATURE. THE STORMS HAVE FORMED ALONG THE TIGHTEST H8 THERMAL RIBBON OVER THE UPPER GREAT LAKES...RIGHT WHERE PREVIOUS CONVECTION DID FROM THE AFTERNOON. SFC TD'S OF 65 TO 70 ARE FEEDING INTO THIS FEATURE FROM THE SOUTHWEST...BUT ITS CURRENT MOVEMENT WILL TRACK IT INTO SOMEWHAT DRIER AIR. ALSO FAVORING THE CONVECTION FOR OUR REGION IS THAT WE ARE NOW IN THE DIURNALLY FAVORED TIME FOR THIS TYPE OF ACTIVITY. AS FAR AS HELP FROM THE MODELS...ALL GUIDANCE IS DOING POORLY WITH THIS...INCLUDING THE RUC. WILL THUS ADD CHC POPS TO SITES FROM BUF TO ROC TO COVER THE POTENTIAL FOR STORMS LATER TONIGHT AS THE ACTIVITY SLIDES SOUTHEAST. $$ .SYNOPSIS... GREAT SUMMER DAY ACROSS FORECAST AREA AS WE REMAIN IN SLOT BETWEEN EXITING SHORT WAVE TO EAST AND DYING MCS TO OUR NORTHWEST. WEAK SFC BOUNDARY MAY PRODUCE SCATD CONVECTION MONDAY BUT UPPER RIDGE GRADUALLY BUILDS EASTWARD ACROSS LOWER LAKES THEREAFTER WITH WARMING AT ALL LEVELS...RESULTING IN INCREASING HEAT AND HUMIDITY FOR THE TUES THROUGH THURS PERIOD...WITH LITTLE CHANCE OF CONVECTION. NEXT COLD FRONT PROGGED FOR LATER FRIDAY...WITH PLEASANT WX RETURNING FOR NEXT WEEKEND. && .SHORT TERM (TONIGHT THROUGH WEDNESDAY)... 12Z MODELS CONTINUE TO SHOW WEAK BOUNDARY/MID LEVEL SHORT WAVE DROPPING SOUTHEAST IN UPPER FLOW FROM UPPER LAKES ON MONDAY...BUT BOTH A BIT FURTHER NORTH THAN 00Z RUN...FOCUSING ON LK ONTARIO REGION. CURRENTLY CARRYING 30 POPS AND DO NOT FEEL COMFORTABLE DROPPING...BUT WITH INCREASING SW FLOW EXPECT BUF AREA TO BE SHADOWED IN AFTERNOON AND WILL PLAY GRIDS ACCORDINGLY. IN ANY CASE WILL HOLD ONTO BROADBRUSH 30 POPS FOR THE DAY WITH SOME INCREASE IN HUMIDITY. TEMPS SHOULD BE SIMILAR TO TODAY'S...GENERALLY L-M 80S WITH SLIGHTLY HIGHER 850 TEMPS OFFSET BY A BIT MORE CLOUDINESS. UPPER RIDGE FLATTENS AND EXTENDS OVER US BY TUES AFTER THIS RIPPLE EXITS...AND ALL SIGNS POINT TO ANOTHER SPELL OF HOT WX WITH INCREASING HUMIDITY FROM TUES-THURS. 850 TEMPS OF 17C TUES RISE TO 19C WED/THURS...SO WILL GO WITH 85-90 BUT COULD EASILY SEE SOME LOWER 90S...ESP WED/THURS. WILL HOLD POPS AT 20 ON TUES FOR ANY LINGERING BOUNDARIES...BUT DROP TO 10-15 RANGE WED WITH GOOD CAPPING. && .LONG TERM (THURSDAY THROUGH SUNDAY)... WARMTH AND HUMIDITY WILL CONTINUE THROUGH THE END OF THE WEEK WITH MID TO UPPER 80S EXPECTED THURSDAY...THEN LOWER 80S WITH THE GREATER RISK OF SHRA/TSRA ON FRIDAY. WENT MAINLY WITH HPC EXTENDED TEMPS/CLOUDS/POPS WHICH HAVE LITTLE OR NO PRECIP POSSIBLE UNTIL THE END OF THE WEEK...THEN A STRONGER COLD FRONT IS EXPECTED ON FRIDAY TIMED WITH PEAK AFTERNOON TEMPS...THUS RISK OF STRONGER STORMS. LOWER 80S AND DRIER CONDITIONS NEXT WEEKEND. && .AVIATION... MID AND HIGH CLOUDS HAVE INCREASED OVER THE NORTHERN PARTS OF WESTERN NEW YORK AS SPILL FROM CONVECTION CONTINUES TO MOVE SOUTHEAST FROM THE BRUCE PENINSULA NEAR THE SOUTHERN SECTION OF GEORGIAN BAY. SOME FREQUENT LIGHTNING AT THIS TIME. BIGGEST QUESTION IS IF THE STORMS WILL CONTINUE TO WEAKEN AS THEY MOVE SOUTHEAST INTO DRIER AIR AS THEY HAVE EARLIER TODAY. IF THEY HOLD TOGETHER THEY COULD REACH IAG...BUF AND ROC OVERNIGHT. GENERALLY VFR CONDITIONS WILL PREVAIL ALTHOUGH MVFR CONDITIONS ARE POSSIBLE IF THE CONVECTIVE ACTIVITY HOLDS TOGETHER. && .CLIMO... BUF'S MAX SO FAR OF 83 TODAY ASSURES CITY OF ITS WARMEST JUNE-JULY COMBO IN HISTORY (EDGING OUT 1949). JULY'S 75.0 AVG WILL MAKE IT WARMEST IN 50 YRS AND 3RD WARMEST EVER. THIS FOLLOWS JUNE WHICH WAS WARMEST IN 39 YRS AND 4TH WARMEST EVER. IMPRESSIVE STUFF. ROC'S NUMBERS ABOUT 2 DEG COOLER...SO NO RECORD TERRITORY THERE BUT STILL IN TOP FIFTH OF SUMMERS SO FAR. MORE ON THIS IN CLMS MONDAY. && .BUFFALO WATCHES/WARNINGS/ADVISORIES... .NY...NONE. .MARINE...NONE. $$ UPDATE...RSH SYNOPSIS/SHORT TERM/CLIMO...MCLAUGHLIN LONG TERM/MARINE...HIBBERT AVIATION...SAGE ny AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE RALEIGH NC 945 PM EDT SUN JUL 31 2005 .SHORT TERM (REST OF TONIGHT THROUGH MONDAY)... MAIN ADJUSTMENT TO NEAR TERM FORECAST WAS TO LOWER POPS..ESPECIALLY NORTH HALF...AND TO ADJUST DEWPOINTS TONIGHT INTO MON. MSAS ANALYSIS DEPICTS LOW LEVEL CONFLUENCE AXIS OVER FAR SE COUNTIES. THIS AGREES FAIRLY WELL WITH MESO-ETA PROGS OF BEST LOW LEVEL CONVERGENCE EDGING E FROM WESTERN/SOUTHERN PIEDMONT TO THE SOUTHERN COASTAL PLAIN OVERNIGHT. THUS...DECREASED POPS OVER THE NORTH HALF TO SMALL CHANCE (WHICH STILL MAY BE TOO HIGH) TO LIKELY OVER THE SOUTHERN THIRD. STILL CANNOT RULE OUT AN ISOLATED POCKETS OF HEAVY RAIN OVERNIGHT...BUT FAR SOUTH/SOUTHEAST COUNTIES HAVE BEEN SPARED HEAVY DOWNPOURS PAST 6 HOURS. DRIER DEWPOINTS PROGGED BY SHORT TERM GUIDANCE TO ADVECT INTO REGION APPEARS TO BE TOO AGGRESSIVE OR TOO FAST. DEWPOINTS ACROSS VA RANGE FROM LOWER 70S EAST TO THE MID 60S FOOTHILLS/MOUNTAINS. ADJUSTED DEWPOINTS 2-3 DEGREES HIGHER OVERNIGHT/MON ACROSS THE NORTHERN COUNTIES. CONSEQUENTLY...RAISED MIN TEMPS OVERNIGHT IN THE NW PIEDMONT. SHORT TERM MODEL GUIDANCE COMING INTO BETTER AGREEMENT CONCERNING ADVECTION OF DRIER AIR INTO THE REGION. HOWEVER ONE HAS TO WONDER IF MODELS MAY BE TOO AGGRESSIVE WITH DRYING CONSIDERING RATHER WEAK LOW/MID LEVEL FLOW. IF MODELS TO BE BELIEVE...LITTLE IF ANY CONVECTION WILL OCCUR ACROSS CENTRAL NC MON. HAVE MORE FAITH IN PREVIOUS FORECAST AS ENOUGH RESIDUAL MOISTURE WILL LIKELY REMAIN TO SUPPORT ISOLATED/SCATTERED CONVECTION...ESPECIALLY IN THE AFTERNOON. && .PREVIOUS DISCUSSION... (ISSUED 215 PM EDT SUN JUL 31 2005) SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)... THIS EVENING...SATELLITE IMAGERY SUGGEST A WAVE MOVING NORTH FROM THE SAVANNAH BASIN THIS AFTERNOON AND EXTRAPOLATION TAKES IT NE THROUGH THE RAH CWA 20-02Z THIS EVENING. LATEST VWP PLOTS CONTINUE TO SHOW A MID LEVEL CYCLONIC CIRCULATION OVER THE CENTRAL PIEDMONT WITH CONFLUENCE IN THE LOWER LEVELS ACROSS THE SOUTHERN HALF. RUC SHOWS AN AXIS OF DEEP SATURATION WITH A SHARP INVERTED 850-700 MB TROUGH BISECTING THE CWA SW-NE AND A PERTURBATION RUNNING UP THE TROUGH 21-03Z. DEEP CONVECTION/MCS WILL LIKELY FOLLOW UP THE SURFACE TROUGH TO OUR EAST IN THE LOWER COASTAL PLAIN AND THERE MAY BE A SHADOWING EFFECT WITH SUBSIDENCE ALOFT ON THE NW PERIPHERY. EVIDENCE IN NEAR TERM TRENDS AND PROJECTIONS SUPPORT KEEPING A FLASH FLOOD WATCH...MAINLY OVER THE SE HALF OF THE CWA INTO THIS EVENING UNTIL THE UPPER LEVEL WAVE EXITS NE. TRENDS IN THE NEXT 1-2 HOURS WILL DETERMINE THE FINAL ALIGNMENT FOR THIS EVENING. DYNAMICS WITH A JET AXIS SHIFT EAST BY 06Z...BUT RESIDUAL MOISTURE AND INSTABILITY WILL KEEP A SMALL CHANCE OF SHOWERS OVER THE AREA LATER TONIGHT THROUGH DAYBREAK MONDAY. CONSENSUS GUIDANCE WILL BE USED FOR LOWS TONIGHT 67-72 NW-SE. MON-TUE...SFC-850 FLOW REMAINS WEAK...BUT FLOW FROM HIGH PRESSURE OVER THE OHIO VALLEY BEGINS TO EXTEND INTO CENTRAL NC MID MONDAY. NAM AND GFS CONTINUE TO DIVERGE IN THE AMOUNT OF MOISTURE WITH THE GFS WET AND NAM DRYING THE AIR FROM THE NORTH. CURRENT POP GRIDS COMPROMISING BETWEEN THE TWO AND SHOWING A LINGERING CHANCE OF SHOWERS IN THE SE HALF ARE FAVORED. A SLIGHT CHANCE FOR SHOWERS WILL BE ADDED FOR MON NGT AND TUE UNDER MOSTLY OR VARIABLY CLOUDY SKIES. MODEL THICKNESS SUPPORTS HIGHS MONDAY IN THE MID TO UPPER 80S...AND 88-92 ON TUE. LOWS 67-71. WED-WED NGT...HIGH PRESSURE AT SFC-850 RIDGES INTO THE AREA FROM THE NW. MODEL SOUNDINGS SHOW A GENERALLY DRIER AIRMASS...BUT ETA SHOWS AN UNSTABLE LAPSE RATE WITH MID LEVEL MOISTURE. ISOLATED LATE DAY THUNDERSTORMS MAY BE POSSIBLE...BUT CHANCE SHOULD BE LOW ENOUGH TO EXCLUDE FOR NOW UNTIL IT BECOMES BETTER DEFINED. NAM LOW LEVEL THICKNESS IS 20M GREATER THAN GFS...BUT A COMPROMISE AND ADDITIONAL SUNSHINE WED WOULD SUGGEST MAX TEMPERATURES 1-3 DEGREES HIGHER WED THAN TUE. LOWS WED NGT...68-72. -RFG LONG TERM (THURSDAY THROUGH SUNDAY)... NO SIGNIFICANT CHANGES WERE MADE TO THE EXTENDED. THE FLOW REMAINS WEAK OVER THE REGION WEDNESDAY AND THURSDAY...WITH RIDGING ALOFT AND A SURFACE HIGH OVER THE WESTERN ATLANTIC. A TROUGH AND ASSOCIATED SURFACE FRONT APPROACH FROM THE NORTHWEST ON FRIDAY. THIS ENHANCES THE SOUTHERLY MOISTURE FLOW AND LARGE SCALE LIFT...RAISING POPS TO A CHANCE. THE SURFACE BOUNDARY APPEARS TO STALL SOMEWHERE IN THE AREA...SO WILL CONTINUE CHANCE POPS INTO SUNDAY. TEMPERATURES THROUGH THE PERIOD WILL BE NEAR CLIMO...LOWS AROUND 70 AND HIGHS 85 TO 90. -DGS AVIATION... EXPECT VFR CIGS NORTH TO MVFR CIGS SOUTH THROUGH THE REST OF THE DAY ACROSS MOST OF THE AREA. SCATTERED PATCHES OF RAIN WILL LOWER VIS/CIGS TO IFR THROUGH THE AFTERNOON. FAY WILL HAVE THE BEST CHANCES OF SEEING MODERATE RAIN AND LOWER VIS/CIGS. DRIER AIR IS EXPECTED TO BUILD INTO THE AREA FROM THE NORTH TONIGHT AS THE SHEAR AXIS OVER THE AREA TODAY DRIFTS TO THE SOUTH. RESIDUAL LOW LEVEL MOISTURE WILL ONCE AGAIN LEAD TO LOW CIGS TONIGHT...WITH LIFR LIKELY BEING REACHED AT ALL TAF SITES. FOG SHOULD REMAIN MVFR. WITH DRIER AIR BUILDING IN...CIGS SHOULD LIFT TO MVFR A LITTLE FASTER TOMORROW THAN THE PAST FEW DAYS. -DGS && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...WSS nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 343 PM EDT SUN JUL 31 2005 .SHORT TERM (TONIGHT THROUGH TUESDAY)... SHOWERS AND THUNDERSTORMS ENDING THIS EVENING AS MESO LOW MOVING ALONG THE FRONT SLOWLY EXITS THE REGION. LATEST RUC SHOWING WEAK SHORT WAVE ASSOCIATED WITH THE SURFACE FEATURE...HELPING TO ENHANCE CONVECTION. LARGE AMOUNTS OF RAIN WILL ALSO LEAD TO AREAS OF FOG CLOSE TO DAYBREAK...FOR NOW PATCHY FOG SHOULD SUFFICE. MANY AREAS HAVE SEEN OVER 3 INCHES OF RAIN IN THE PAST 24 HOURS WHICH HAS RESULTED IN SOME NUISANCE FLOODING. SURFACE BOUNDARY IS EXPECTED TO REMAIN CLOSE TO THE REGION TOMORROW BUT WILL BE SOMEWHAT WEAKER. BEST DYNAMICS WILL BE FOUND SOUTH OF THE REGION WITH HEAVIEST PRECIP OUTSIDE THE FA. BOTH NAM AND CANADIAN IN GOOD AGREEMENT ON THIS FACT. BOTH OF THESE MODELS DID A GOOD JOB FORECASTING PRECIP LOCATION AND AMOUNTS FOR TODAY...SEE NO REASON NOT TO TRUST THEM FOR TOMORROW. KEEPING HIGH CHANCE POPS WITH QPF VALUES UNDER A TENTH OF AN INCH. BASED ON THIS DO NOT SEE THE NEED TO ISSUE FLOOD WATCH FOR TOMORROW. SURFACE BOUNDARY SLOWLY DROPS SOUTH OF THE AREA MONDAY NIGHT INTO TUESDAY AS HIGH PRESSURE BUILDS IN FROM THE NORTH. CONTINUE TO FAVOR THE SLIGHTLY FASTER NAM/CANADIAN OVER THE 12Z GFS WITH RESPECT TO SOUTHWARD MOVEMENT OF BOUNDARY. BELOW CLIMO HIGHS WITH OVERNIGHT LOWS NEAR CLIMO THROUGH THE PERIOD. && .LONG TERM (WEDNESDAY THROUGH SUNDAY)... REMAINS OF SURFACE BOUNDARY WILL STAY SOUTH OF THE ILM AREA THROUGH FRIDAY BEFORE SLOWLY RETURNING NORTH NEXT WEEKEND AS BERMUDA HIGH DEVELOPS. DRIER AIR OVER THE REGION WEDNESDAY AND THURSDAY WILL LIMIT POPS BUT MOISTURE WILL BE INCREASING LATE IN THE PERIOD AS SOUTHERLY FLOW DEVELOPS. INCREASED MOISTURE RESULTS IN BETTER PRECIP CHANCES. TEMPERATURES AT TO SLIGHTLY BELOW CLIMO ARE EXPECTED THROUGH THE EXTENDED PERIOD. && MARINE... CURRENTLY A MESOSCALE LOW IS WORKING ITS WAY UP THE COAST WITH ITS CENTER NEAR THE COAST JUST NORTH OF WINYAH BAY. WINDS AT THE CARO-COOPS BUOY SUN2 HAD A MAX OF 16 KTS IN THE CONVECTION BUT THE RADAR IS SHOWING A 30 TO 35 KT AT 1000 FT. REPORTS ON THE COAST INDICATE WINDS HAVE INCREASED OVER THE PAST HOUR. WILL MENTION STRONGER WIND AND SEAS WITH THIS FEATURE AND THE ONGOING CONVECTION BUT AS MESO LOW PULLS NORTHEAST OUT OF THE REGION ANTICIPATE SEAS TO SETTLE DOWN A BIT. WINDS ARE FORECAST TO REMAIN BELOW 15 KTS AS STALLED FRONTAL BOUNDARY WILL GIVE WAY TO HIGH PRESSURE BY THE END OF THE FORECAST PERIOD. WAVE WATCH SHOWING SEA OF 2 TO 3 FT FOR THE REMAINDER OF THE PERIOD. && AVIATION... NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS IN PLACE ACROSS THE AREA SHOULD BEGIN TO DECREASE IN COVERAGE THIS EVENING. AS THE CASE THE PAST COUPLE OF NIGHTS...THE COASTAL TERMINALS MAY EXPERIENCE ANOTHER ROUND OF CONVECTION OVERNIGHT...WHILE INLAND AT KFLO PATCHY DENSE FOG MAY DEVELOP TOWARD DAYBREAK. ALL TERMINALS COULD SEE ADDITIONAL CONVECTION TOWARD THE END OF THE FORECAST PERIOD WITH THE HEATING OF THE DAY ON MONDAY. CONDITIONS COULD DETERIORATE TO MVFR OR IFR AT TIMES IN/NEAR CONVECTION...WITH LIFR CONDITIONS POSSIBLE AT KFLO WITH THE FOG TOWARD DAYBREAK. && .ILM WATCHES/WARNINGS/ADVISORIES... NC...NONE. SC...NONE. MARINE...NONE. && $$ MARINE...HAWKINS AVIATION...JAQ nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 215 PM EDT SUN JUL 31 2005 .SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)... THIS EVENING...SATELLITE IMAGERY SUGGEST A WAVE MOVING NORTH FROM THE SAVANNAH BASIN THIS AFTERNOON AND EXTRAPOLATION TAKES IT NE THROUGH THE RAH CWA 20-02Z THIS EVENING. LATEST VWP PLOTS CONTINUE TO SHOW A MID LEVEL CYCLONIC CIRCULATION OVER THE CENTRAL PIEDMONT WITH CONFLUENCE IN THE LOWER LEVELS ACROSS THE SOUTHERN HALF. RUC SHOWS AN AXIS OF DEEP SATURATION WITH A SHARP INVERTED 850-700 MB TROUGH BISECTING THE CWA SW-NE AND A PERTURBATION RUNNING UP THE TROUGH 21-03Z. DEEP CONVECTION/MCS WILL LIKELY FOLLOW UP THE SURFACE TROUGH TO OUR EAST IN THE LOWER COASTAL PLAIN AND THERE MAY BE A SHADOWING EFFECT WITH SUBSIDENCE ALOFT ON THE NW PERIPHERY. EVIDENCE IN NEAR TERM TRENDS AND PROJECTIONS SUPPORT KEEPING A FLASH FLOOD WATCH...MAINLY OVER THE SE HALF OF THE CWA INTO THIS EVENING UNTIL THE UPPER LEVEL WAVE EXITS NE. TRENDS IN THE NEXT 1-2 HOURS WILL DETERMINE THE FINAL ALIGNMENT FOR THIS EVENING. DYNAMICS WITH A JET AXIS SHIFT EAST BY 06Z...BUT RESIDUAL MOISTURE AND INSTABILITY WILL KEEP A SMALL CHANCE OF SHOWERS OVER THE AREA LATER TONIGHT THROUGH DAYBREAK MONDAY. CONSENSUS GUIDANCE WILL BE USED FOR LOWS TONIGHT 67-72 NW-SE. MON-TUE...SFC-850 FLOW REMAINS WEAK...BUT FLOW FROM HIGH PRESSURE OVER THE OHIO VALLEY BEGINS TO EXTEND INTO CENTRAL NC MID MONDAY. NAM AND GFS CONTINUE TO DIVERGE IN THE AMOUNT OF MOISTURE WITH THE GFS WET AND NAM DRYING THE AIR FROM THE NORTH. CURRENT POP GRIDS COMPROMISING BETWEEN THE TWO AND SHOWING A LINGERING CHANCE OF SHOWERS IN THE SE HALF ARE FAVORED. A SLIGHT CHANCE FOR SHOWERS WILL BE ADDED FOR MON NGT AND TUE UNDER MOSTLY OR VARIABLY CLOUDY SKIES. MODEL THICKNESS SUPPORTS HIGHS MONDAY IN THE MID TO UPPER 80S...AND 88-92 ON TUE. LOWS 67-71. WED-WED NGT...HIGH PRESSURE AT SFC-850 RIDGES INTO THE AREA FROM THE NW. MODEL SOUNDINGS SHOW A GENERALLY DRIER AIRMASS...BUT ETA SHOWS AN UNSTABLE LAPSE RATE WITH MID LEVEL MOISTURE. ISOLATED LATE DAY THUNDERSTORMS MAY BE POSSIBLE...BUT CHANCE SHOULD BE LOW ENOUGH TO EXCLUDE FOR NOW UNTIL IT BECOMES BETTER DEFINED. NAM LOW LEVEL THICKNESS IS 20M GREATER THAN GFS...BUT A COMPROMISE AND ADDITIONAL SUNSHINE WED WOULD SUGGEST MAX TEMPERATURES 1-3 DEGREES HIGHER WED THAN TUE. LOWS WED NGT...68-72. -RFG && .LONG TERM (THURSDAY THROUGH SUNDAY)... NO SIGNIFICANT CHANGES WERE MADE TO THE EXTENDED. THE FLOW REMAINS WEAK OVER THE REGION WEDNESDAY AND THURSDAY...WITH RIDGING ALOFT AND A SURFACE HIGH OVER THE WESTERN ATLANTIC. A TROUGH AND ASSOCIATED SURFACE FRONT APPROACH FROM THE NORTHWEST ON FRIDAY. THIS ENHANCES THE SOUTHERLY MOISTURE FLOW AND LARGE SCALE LIFT...RAISING POPS TO A CHANCE. THE SURFACE BOUNDARY APPEARS TO STALL SOMEWHERE IN THE AREA...SO WILL CONTINUE CHANCE POPS INTO SUNDAY. TEMPERATURES THROUGH THE PERIOD WILL BE NEAR CLIMO...LOWS AROUND 70 AND HIGHS 85 TO 90. -DGS && .AVIATION... EXPECT VFR CIGS NORTH TO MVFR CIGS SOUTH THROUGH THE REST OF THE DAY ACROSS MOST OF THE AREA. SCATTERED PATCHES OF RAIN WILL LOWER VIS/CIGS TO IFR THROUGH THE AFTERNOON. FAY WILL HAVE THE BEST CHANCES OF SEEING MODERATE RAIN AND LOWER VIS/CIGS. DRIER AIR IS EXPECTED TO BUILD INTO THE AREA FROM THE NORTH TONIGHT AS THE SHEAR AXIS OVER THE AREA TODAY DRIFTS TO THE SOUTH. RESIDUAL LOW LEVEL MOISTURE WILL ONCE AGAIN LEAD TO LOW CIGS TONIGHT...WITH LIFR LIKELY BEING REACHED AT ALL TAF SITES. FOG SHOULD REMAIN MVFR. WITH DRIER AIR BUILDING IN...CIGS SHOULD LIFT TO MVFR A LITTLE FASTER TOMORROW THAN THE PAST FEW DAYS. -DGS && .RAH WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH FOR NCZ007>011-021>028-038>043-073>078- 083>086-088-089 UNTIL 6 PM SUNDAY. && $$ SHORT TERM...RFG LONG TERM...DGS AVIATION...DGS nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 944 AM EDT SUN JUL 31 2005 .SHORT TERM (REST OF TODAY)... A FLASH FLOOD WATCH HAS BEEN ISSUED FOR THE RAH CWA THE REMAINDER OF TODAY. FROM PREVIOUS UPDATE... RAOBS SHOW DEEP SATURATION ACROSS CENTRAL NC THIS MORNING...A MOIST ADIABATIC LAPSE RATE THROUGHOUT THE COLUMN...AND WEAK FLOW IN THE LOWER TO MID LEVELS. AREA VWPS SHOW A CYCLONIC CIRCULATION AND CONVERGENCE IN THE LOWER AND ESPECIALLY MID LEVELS NEAR 10 THSD FT. THE RUC PROJECTS A WEAK LOW AND VORTICITY MAXIMUM OVER THE SOUTHERN PIEDMONT AT 12Z DRIFTING SLOWLY NORTHWARD THROUGH THE SANDHILLS AND INTO THE NE PIEDMONT THIS AFTERNOON. 12Z DATA SET ALOFT ALSO IS SHOWING A SIGNIFICANT TROUGH AT JET LEVEL OVER THE SOUTHERN APPALACHIANS AND IMPLIED SHARP ASCENT OVER THE REGION WITH DIVERGENCE ALOFT. CONDITIONS APPEAR FAVORABLE FOR AREAS OF MODERATE TO HEAVY RAIN AND EMBEDDED THUNDERSTORMS. POPS HAVE BEEN RAISED TO HIGH LIKELY OR CATEGORICAL FOR THE REMAINDER OF THE DAY WITH MAXIMUM INTENSITY AND COVERAGE THROUGH THE MIDDLE OF THE RAH CWA. MAX TEMPERATURES SHOULD REMAIN MODERATE 78-84...BUT DEWPOINTS WILL REMAIN HIGH...IN THE LOWER TO MID 70S. -RFG && .PREVIOUS DISCUSSION... (ISSUED 302 AM EDT SUN JUL 31 2005) SHORT TERM (TODAY THROUGH TUESDAY NIGHT)... SURFACE TROUGH REMAINS OVER CENTRAL NORTH CAROLINA...WITH 850MB CONVERGENCE OVER THE FORECAST AREA AND A SHEAR AXIS IN A WEAKNESS IN THE RIDGE AT 500MB OVERHEAD. PLENTIFUL MOISTURE REMAINS WITH THE 00Z RAOB ANALYSIS SHOWING 850MB DEW POINTS IN THE TEENS...AND THE SATELLITE WATER VAPOR LOOP CONTINUING TO SHOW HIGH MID-LEVEL MOISTURE. SURFACE DEW POINTS RANGE FROM NEAR 70 TO JUST SHY OF 75. ONGOING SHOWERS TOWARD THE TRIAD IN AN AREA OF SLIGHTLY HIGHER INSTABILITY AND SURFACE THETA-E ON MSAS ANALYSIS...AND ALREADY SCATTERED SHOWERS HAVE DEVELOPED OR INCREASED IN AREAL COVERAGE SLIGHTLY NORTH OF KCAE AND SOUTHWEST OF KILM. MSAS SURFACE THETA-E VALUES ARE HIGH PARTICULARLY FROM KRDU SOUTH THROUGH KFAY...AND WOULD NOT BE SURPRISED IF A FEW SHOWERS MOVED IN OR DEVELOPED DURING THE EARLY MORNING HOURS. EXPECT THE BETTER CHANCES OF SHOWERS AND SCATTERED THUNDERSTORMS SOUTHERN ZONES AND ALONG AND EAST OF THE I-95 CORRIDOR AS BOTH THE GFS AND THE NAM FORECAST THE SURFACE TROUGH AND THE BEST UVV AND CONVERGENCE IN THOSE AREAS LATE IN THE DAY. HAVE THE HIGHEST QPF IN THE GRIDDED FORECAST IN THOSE LOCATIONS AND ANY HEAVY SHOWER...MOVING SLOWLY ENOUGH WITH 700MB AND 500MB WINDS ONLY BETWEEN 5 AND 10 KNOTS...COULD PROVIDE FOR LOCAL FLOODING. WILL MENTION IN THE HWO...AND WILL NOT ISSUE ANY FLOOD WATCH AS STORM TOTAL PRECIPITATION ON THE KRAX WSR-88D SHOWS A GENERAL ONE TO TWO INCHES...WITH SLIGHTLY HIGHER AMOUNTS...OVER A LENGTHY 48 HOURS. BOTH MODELS ACTUALLY FORECAST GRADUALLY DIMINISHING 850MB AND 700MB THETA-E VALUES TOWARD THE TRIAD TODAY WITH INCREASED SURFACE RIDGING. THE TREND OF BOTH THE GFS AND THE NAM IS TO SLOWLY SINK THE MID-LEVEL SHEAR AXIS SOUTH AND USHER DRIER AIR IN THE MEAN OVER CENTRAL NORTH CAROLINA MONDAY INTO TUESDAY. SHEAR AXIS REMAINS OVER SOUTHERN ZONES MONDAY...AND DESPITE THE NAM FORECAST OF AN 850MB THETA-E TROUGH OVER THE FORECAST AREA...WEAK UVV AT BEST...AND CONVERGENCE ALOFT...LIGHT WINDS FROM 700MB THROUGH 500MB SHOULD RESULT IN ONLY MODEST CHANGES TO OVERALL MOISTURE AT LEAST INTO MONDAY AFTERNOON. NOT WANTING TO DRY THINGS OUT TOO FAST... MAINTAINED SLIGHT CHANCE OR CHANCE POPS MONDAY AFTERNOON EXCEPT IN THE TRIAD WHERE MOISTURE IN THE LEAST AND WHERE SURFACE CONVERGENCE IS MOST DISTANT. MOS POPS HAVE REALLY TRENDED DOWNWARD ESPECIALLY TOWARD THE TRIAD AND AT THIS POINT CONFIDENCE IS HIGH ENOUGH TO FORECAST A DRY DAY TOWARD GSO AND INT ON MONDAY. MOISTURE DIMINISHES AT ALL LEVELS MONDAY NIGHT AND WOULD EXPECT SOME GOOD CLEARING OVERNIGHT THEN. WILL NOT MENTION IN THE FORECAST AT THIS POINT...BUT WITH LIGHT WINDS FORECAST AT 925MB AND RELATIVELY LOW MOISTURE PATCHY FOG COULD OCCUR LATE MONDAY NIGHT. PRECIPITABLE WATER VALUES ARE LOWEST LATE MONDAY INTO EARLY TUESDAY...BUT A GRADUAL INCREASE FROM THE NORTH IS FORECAST LATE TUESDAY INTO WEDNESDAY. WEAK SURFACE RIDGE IS IN PLACE EARLY TUESDAY...BUT THE NAM FORECASTS A LEE TROUGH TO DEVELOP OVER THE WESTERN PART OF THE STATE BY TUESDAY AFTERNOON. IF THE NAM VERIFIES...WITH LIFTED INDICES AROUND -3C OVER SOUTHWEST VIRGINIA AND SOUTHERN WEST VIRGINIA TUESDAY AFTERNOON...A FEW SHOWERS DEVELOPING ALONG THE TROUGH COULD SLIDE SOUTH AROUND THE 700MB RIDGE AND AFFECT AREAS MAINLY FROM ROXBORO THROUGH THE TRIAD LATE IN THE DAY TUESDAY AND EARLY TUESDAY EVENING. THE GFS IS STRONGER WITH SURFACE RIDGING IN THAT AREA AND...THROUGH COORDINATION WITH RNK...WILL LEAVE THE FORECAST THERE DRY FOR NOW. TEMPERATURES CHANGED LITTLE FROM THE ONGOING FORECAST...EXCEPT LOWERED MINS A CATEGORY ON AVERAGE MAINLY DURING THE EARLY PART OF THE WORK WEEK DUE TO SLIGHTLY DRIER AIR EXPECTED. FOR THE SAME REASON AND WITH A LITTLE MORE SUN RAISED MAXES ABOUT A CATEGORY AS WELL. TEMPERATURES SHOULD BE BACK ABOUT A CATEGORY OR SO ABOVE NORMAL BY TUESDAY. MANY THANKS TO NEARBY OFFICES FOR COLLABORATION EARLY THIS MORNING. LONG TERM (WEDNESDAY THROUGH SATURDAY)... NO CHANGE TO THE ONGOING EXTENDED FORECAST. GFS FORECASTS SURFACE HIGH PRESSURE TO BE THE RULE FOR THE MIDDLE PART OF THE UPCOMING WORK WEEK. MORE PRONOUNCED SURFACE TROUGHINESS DEVELOPS ALONG THE COAST LATE THURSDAY AND INTO FRIDAY. CURRENT FORECAST HAS THE EXPECTED CONDITIONS HANDLED WELL AT THIS POINT. AVIATION... CIGS WILL LOWER DURING THE EARLY MORNING AS MOIST NORTHEAST FLOW PERSISTS OVER THE REGION. MVFR CIGS AND VSBYS IN SHOWERS WILL LINGER THROUGH 07Z...THEN CIGS AND VSBYS WILL LOWER TO IFR IN STRATUS AND FOG DUE TO RESIDUAL MOISTURE. VSBYS WILL REBOUND AFTER 15Z...HOWEVER LOW CIGS WILL PERSIST THROUGH THE EARLY AFTERNOON (~18Z)...THEN BECOME MVFR. SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS DEVELOPING DURING THE LATE AFTERNOON AND EVENING. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...RFG nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 904 AM EDT SUN JUL 31 2005 .SHORT TERM (REST OF TODAY)... RAOBS SHOW DEEP SATURATION ACROSS CENTRAL NC THIS MORNING...A MOIST ADIABATIC LAPSE RATE THROUGHOUT THE COLUMN...AND WEAK FLOW IN THE LOWER TO MID LEVELS. AREA VWPS SHOW A CYCLONIC CIRCULATION AND CONVERGENCE IN THE LOWER AND ESPECIALLY MID LEVELS NEAR 10 THSD FT. THE RUC PROJECTS A WEAK LOW AND VORTICITY MAXIMUM OVER THE SOUTHERN PIEDMONT AT 12Z DRIFTING SLOWLY NORTHWARD THROUGH THE SANDHILLS AND INTO THE NE PIEDMONT THIS AFTERNOON. 12Z DATA SET ALOFT ALSO IS SHOWING A SIGNIFICANT TROUGH AT JET LEVEL OVER THE SOUTHERN APPALACHIANS AND IMPLIED SHARP ASCENT OVER THE REGION WITH DIVERGENCE ALOFT. CONDITIONS APPEAR FAVORABLE FOR AREAS OF MODERATE TO HEAVY RAIN AND EMBEDDED THUNDERSTORMS. POPS HAVE BEEN RAISED TO HIGH LIKELY OR CATEGORICAL FOR THE REMAINDER OF THE DAY WITH MAXIMUM INTENSITY AND COVERAGE THROUGH THE MIDDLE OF THE RAH CWA. MAX TEMPERATURES SHOULD REMAIN MODERATE 78-84...BUT DEWPOINTS WILL REMAIN HIGH...IN THE LOWER TO MID 70S. -RFG && .PREVIOUS DISCUSSION... (ISSUED 302 AM EDT SUN JUL 31 2005) SHORT TERM (TODAY THROUGH TUESDAY NIGHT)... SURFACE TROUGH REMAINS OVER CENTRAL NORTH CAROLINA...WITH 850MB CONVERGENCE OVER THE FORECAST AREA AND A SHEAR AXIS IN A WEAKNESS IN THE RIDGE AT 500MB OVERHEAD. PLENTIFUL MOISTURE REMAINS WITH THE 00Z RAOB ANALYSIS SHOWING 850MB DEW POINTS IN THE TEENS...AND THE SATELLITE WATER VAPOR LOOP CONTINUING TO SHOW HIGH MID-LEVEL MOISTURE. SURFACE DEW POINTS RANGE FROM NEAR 70 TO JUST SHY OF 75. ONGOING SHOWERS TOWARD THE TRIAD IN AN AREA OF SLIGHTLY HIGHER INSTABILITY AND SURFACE THETA-E ON MSAS ANALYSIS...AND ALREADY SCATTERED SHOWERS HAVE DEVELOPED OR INCREASED IN AREAL COVERAGE SLIGHTLY NORTH OF KCAE AND SOUTHWEST OF KILM. MSAS SURFACE THETA-E VALUES ARE HIGH PARTICULARLY FROM KRDU SOUTH THROUGH KFAY...AND WOULD NOT BE SURPRISED IF A FEW SHOWERS MOVED IN OR DEVELOPED DURING THE EARLY MORNING HOURS. EXPECT THE BETTER CHANCES OF SHOWERS AND SCATTERED THUNDERSTORMS SOUTHERN ZONES AND ALONG AND EAST OF THE I-95 CORRIDOR AS BOTH THE GFS AND THE NAM FORECAST THE SURFACE TROUGH AND THE BEST UVV AND CONVERGENCE IN THOSE AREAS LATE IN THE DAY. HAVE THE HIGHEST QPF IN THE GRIDDED FORECAST IN THOSE LOCATIONS AND ANY HEAVY SHOWER...MOVING SLOWLY ENOUGH WITH 700MB AND 500MB WINDS ONLY BETWEEN 5 AND 10 KNOTS...COULD PROVIDE FOR LOCAL FLOODING. WILL MENTION IN THE HWO...AND WILL NOT ISSUE ANY FLOOD WATCH AS STORM TOTAL PRECIPITATION ON THE KRAX WSR-88D SHOWS A GENERAL ONE TO TWO INCHES...WITH SLIGHTLY HIGHER AMOUNTS...OVER A LENGTHY 48 HOURS. BOTH MODELS ACTUALLY FORECAST GRADUALLY DIMINISHING 850MB AND 700MB THETA-E VALUES TOWARD THE TRIAD TODAY WITH INCREASED SURFACE RIDGING. THE TREND OF BOTH THE GFS AND THE NAM IS TO SLOWLY SINK THE MID-LEVEL SHEAR AXIS SOUTH AND USHER DRIER AIR IN THE MEAN OVER CENTRAL NORTH CAROLINA MONDAY INTO TUESDAY. SHEAR AXIS REMAINS OVER SOUTHERN ZONES MONDAY...AND DESPITE THE NAM FORECAST OF AN 850MB THETA-E TROUGH OVER THE FORECAST AREA...WEAK UVV AT BEST...AND CONVERGENCE ALOFT...LIGHT WINDS FROM 700MB THROUGH 500MB SHOULD RESULT IN ONLY MODEST CHANGES TO OVERALL MOISTURE AT LEAST INTO MONDAY AFTERNOON. NOT WANTING TO DRY THINGS OUT TOO FAST... MAINTAINED SLIGHT CHANCE OR CHANCE POPS MONDAY AFTERNOON EXCEPT IN THE TRIAD WHERE MOISTURE IN THE LEAST AND WHERE SURFACE CONVERGENCE IS MOST DISTANT. MOS POPS HAVE REALLY TRENDED DOWNWARD ESPECIALLY TOWARD THE TRIAD AND AT THIS POINT CONFIDENCE IS HIGH ENOUGH TO FORECAST A DRY DAY TOWARD GSO AND INT ON MONDAY. MOISTURE DIMINISHES AT ALL LEVELS MONDAY NIGHT AND WOULD EXPECT SOME GOOD CLEARING OVERNIGHT THEN. WILL NOT MENTION IN THE FORECAST AT THIS POINT...BUT WITH LIGHT WINDS FORECAST AT 925MB AND RELATIVELY LOW MOISTURE PATCHY FOG COULD OCCUR LATE MONDAY NIGHT. PRECIPITABLE WATER VALUES ARE LOWEST LATE MONDAY INTO EARLY TUESDAY...BUT A GRADUAL INCREASE FROM THE NORTH IS FORECAST LATE TUESDAY INTO WEDNESDAY. WEAK SURFACE RIDGE IS IN PLACE EARLY TUESDAY...BUT THE NAM FORECASTS A LEE TROUGH TO DEVELOP OVER THE WESTERN PART OF THE STATE BY TUESDAY AFTERNOON. IF THE NAM VERIFIES...WITH LIFTED INDICES AROUND -3C OVER SOUTHWEST VIRGINIA AND SOUTHERN WEST VIRGINIA TUESDAY AFTERNOON...A FEW SHOWERS DEVELOPING ALONG THE TROUGH COULD SLIDE SOUTH AROUND THE 700MB RIDGE AND AFFECT AREAS MAINLY FROM ROXBORO THROUGH THE TRIAD LATE IN THE DAY TUESDAY AND EARLY TUESDAY EVENING. THE GFS IS STRONGER WITH SURFACE RIDGING IN THAT AREA AND...THROUGH COORDINATION WITH RNK...WILL LEAVE THE FORECAST THERE DRY FOR NOW. TEMPERATURES CHANGED LITTLE FROM THE ONGOING FORECAST...EXCEPT LOWERED MINS A CATEGORY ON AVERAGE MAINLY DURING THE EARLY PART OF THE WORK WEEK DUE TO SLIGHTLY DRIER AIR EXPECTED. FOR THE SAME REASON AND WITH A LITTLE MORE SUN RAISED MAXES ABOUT A CATEGORY AS WELL. TEMPERATURES SHOULD BE BACK ABOUT A CATEGORY OR SO ABOVE NORMAL BY TUESDAY. MANY THANKS TO NEARBY OFFICES FOR COLLABORATION EARLY THIS MORNING. LONG TERM (WEDNESDAY THROUGH SATURDAY)... NO CHANGE TO THE ONGOING EXTENDED FORECAST. GFS FORECASTS SURFACE HIGH PRESSURE TO BE THE RULE FOR THE MIDDLE PART OF THE UPCOMING WORK WEEK. MORE PRONOUNCED SURFACE TROUGHINESS DEVELOPS ALONG THE COAST LATE THURSDAY AND INTO FRIDAY. CURRENT FORECAST HAS THE EXPECTED CONDITIONS HANDLED WELL AT THIS POINT. AVIATION... CIGS WILL LOWER DURING THE EARLY MORNING AS MOIST NORTHEAST FLOW PERSISTS OVER THE REGION. MVFR CIGS AND VSBYS IN SHOWERS WILL LINGER THROUGH 07Z...THEN CIGS AND VSBYS WILL LOWER TO IFR IN STRATUS AND FOG DUE TO RESIDUAL MOISTURE. VSBYS WILL REBOUND AFTER 15Z...HOWEVER LOW CIGS WILL PERSIST THROUGH THE EARLY AFTERNOON (~18Z)...THEN BECOME MVFR. SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS DEVELOPING DURING THE LATE AFTERNOON AND EVENING. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...RFG nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 953 PM EDT SUN JUL 31 2005 .UPDATE /OVERNIGHT/...CONVECTION AGAIN DYING DOWN TONIGHT WITH LOSS OF DAYTIME HEATING. THE FLOW IS NOW GENERALLY EASTERLY...SO DO NOT FORESEE A LOT OF CONVECTION DEVELOPING OFF THE COAST UNTIL CLOSER TO DAYBREAK MONDAY WHEN WIND VEERS TO SOUTH. RUC INDICATES SOME MOISTURE FLUX CONVERGENCE IN THE BL ALONG THE COAST WHICH SHOULD CONTINUE FOR A FEW MORE HRS. SHOULD SEE A FEW SHOWERS ALONG THE CONVERGENCE AXIS UNTIL EARLY MONDAY MORNING...BUT DO NOT FORESEE A WIDESPREAD PRECIP EVENT BASED ON THE LIMITED INSTABILITY AND RELAXING FLOW EXPECTED. WILL REALIGN POPS TO REFLECT THIS IDEA WITH THE LAND AREAS REDUCING THROUGH THE NIGHT AND COASTAL/OFFSHORE INCREASING A TAD. FOG STABILITY INDEX INDICATES A HIGH LIKELIHOOD OF PATCHY FOG THIS MORNING ESP B/C OF THE COVERAGE OF RAIN TODAY AND EXPECTED PARTIAL CLEARING LATE. WILL ADD PATCHY FOG TO GRIDS AND TEXT PRODUCTS. TWEAKED TEMPS DOWN SLIGHTLY WHERE RAIN FELL EARLIER. && .MARINE...FEW CHANGES TO ONGOING THINKING. TRANQUIL CONDS...OUTSIDE OF CONVECTIVE ACTIVITY...TO REMAIN ACRS THE MARINE AREA THRU MIDWEEK. DISSIPATING FNTL BNDRY OFFSHORE TO BE REPLACED BY HIGH PRESSURE WHICH WILL ALLOW FOR A MORE SOLID ONSHORE FLOW. WIND SPEEDS TO REMAIN AOB 15 KT AND SEAS AOB 4 FT. && .AVIATION...00Z TAFS REFLECT A BRIEF PERIOD OF MVFR BR THIS MORNING FOLLOWED BY RAPIDLY IMPROVING CONDITIONS. WINDS SHOULD RETURN TO MORE SOUTHERLY BY MID-MORNING AND ANOTHER ROUND OF CONVECTION DURING THE DAY. WILL TOY WITH POSSIBLE PREVAILING WX GROUP ON 06Z TAFS. && .CHS WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. MARINE...NONE. && $$ JRL sc AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 917 PM EDT SUN JUL 31 2005 .SHORT TERM (REST OF TONIGHT)... WATER VAPOR AT 1Z DEPICTS A S/W OVER THE UPSTATE...SLOWLY DRIFTING EAST. RUC SHOWS THAT THE VORT WILL CONTINUE TO CREEP EASTWARD OVERNIGHT. CURRENTLY...THE VORT IS MAINTAINING A CONVECTIVE BAND OVER THE EASTERN PIEDMONT. THIS BAND SHOULD CONTINUE TO SLIDE SE THIS EVENING AND EARLY MON MORNING. LATEST FLP AND MAV RUNS INDICATES THAT COVERAGE WILL BECOME SCT AFTER 6Z...WILL KEEP DECREASING TREND IN THE GOING FORECAST GRIDS. NAM FORECAST SOUNDINGS INDICATE THAT THE BL WILL BECOME NEARLY SATURATED AROUND 5Z AND REMAIN UNTIL SUNRISE. LLVL STRATUS SHOULD BECOME WIDESPREAD TONIGHT WITH PATCHY FOG. GOING TEMPS LOOK GOOD...WILL MAKE ONLY MINOR ADJUSTMENTS. && .PREVIOUS DISCUSSION... (ISSUED 250 PM EDT SUN JUL 31 2005) SHORT TERM (TONIGHT THROUGH TUESDAY)... REGIONAL 88D LOOPS INDICATE NUMEROUS SHOWERS AND TSTMS CONTINUING TO PIVOT AROUND MID-LVL SHEAR AXIS. VERY LITTLE SHEAR THROUGHOUT THE DEPTH OF THE ATMOSPHERIC COLUMN AND PWATS CONTINUING TO RUN AROUND 2 INCHES...LEADING TO SLOW MOVING STORMS WITH LOCALLY HEAVY RAINFALL THREAT UNTIL ABOUT MID-EVENING. CVRG IS EXPECTED TO DIMINISH AS THE EVENING WEARS ON THANKS TO LOSS OF HTG...AFOREMENTIONED SHEAR AXIS AND UPPER JET CORE SLIPPING SE OF THE CWFA...BUT CANNOT RULE OUT ISOLATED TO SCATTERED CVRG LINGERING INTO THE OVERNIGHT HOURS WITH RESIDUAL INSTABILITY AND EASTERLY LLVL FLOW. CWFA LOOKS TO REMAIN WITHIN UPPER LVL WEAKNESS MONDAY BUT DRIER AIR FROM LLVL HIGH PRESSURE IS EXPECTED TO WORK FURTHER SOUTH INTO THE CWFA. 12 UTC GFS AND NAM CONTINUE TO BE AT ODDS IN HANDLING DISPLACEMENT OF DEEPER RH SOUTHWARD. PROBABLY BEST TO CONTINUE TO SHY AWAY FROM AGGRESSIVE GFS GIVEN TRACK RECORD LAST 2 OR 3 DAYS...AND WX GRIDS WILL FEATURE LOW CHANCE POP FOR SHOWERS AND THUNDERSTORMS MONDAY AFTERNOON AND EVENING. NOMINAL CHANGE IN THE WX PATTERN FOR TUESDAY WITH LINGERING UPPER WEAKNESS...BUT HEIGHTS A TAD HIGHER ALTHOUGH EASTERLY FLOW A LITTLE DEEPER. OVERALL... ATMOSPHERE SHOULD DRY OUT A LITTLE MORE...SO HAVE LIMITED CHANCE POPS TO JUST SW ZONES. LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)... NOTHING TERRIBLY UNUSUAL ABOUT THE PATTERN FOR THE EXTENDED PERIOD AS BROAD LOW AMPLITUDE RIDGING OVER THE CENTRAL CONUS ON WEDNESDAY GRADUALLY RETROGRADES...RESULTING IN SLIGHT LOWERING OF HEIGHTS ACROSS THE EASTERN UNITED STATES BY NEXT WEEKEND. ALL IN ALL...AS FAR AS SENSIBLE WEATHER GOES...LITTLE DEVIATION FROM EARLY AUGUST NORMALS AND DAILY DEEP CONVECTIVE CHANCES. AVIATION... WEAK WEDGE OVER EASTER PART OF AREA WILL CONTINUE TO WEAKEN THROUGH THE NIGHT. CONVECTION CONTG THRU AFTN AND EVE WITH MOST COVERAGE IN THE SOUTH AND EAST COUNTIES. PRECIP WILL DIMINISH DURG THE LATE EVE. HIGH PROB THAT ALL TAF SITES WILL GET SOME TYPE OF PRECIP DURG NEXT 8 HOURS...SO EXTENSIVE IFR CONDS WILL PREVAIL FROM MIDN TO SUNRISE. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SHORT TERM...NED sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 927 AM EDT SUN JUL 31 2005 .SHORT TERM (REST OF TODAY THROUGH TONIGHT)... MINIMAL CHANGES IN MORNING PACKAGE AS FIRST LOOK OF DATA IS IN LINE WITH PREVIOUS GUIDANCE. WEAKENING SHEAR LINE OVER THE AREA STILL THE FOCUS OF PRECIP. PREFERRED NAM FOCUSES AFTERNOON PRECIP TO SOUTH AND EASTERN COUNTIES...WHILE RUC AND GFS CONCENTRATE PRECIP TO WEST AND NORTH. WITH NO REAL BOUNDARIES SHOWING UP IN MESOSCALE...WILL KEEP PRECIP FOCUSED IN SOUTHEAST PART OF AREA. TEMPS STAY THE SAME. && .PREVIOUS DISCUSSION... (ISSUED 147 AM EDT SUN JUL 31 2005) SHORT TERM (TODAY THROUGH TUESDAY NIGHT)... UPPER LEVEL SHEAR AXIS REMAINS OVER S APPALACHIANS THROUGH TUE...BUT BECOMES LESS DEFINED AS ATLATNIC RIDGE WEAKENS AND WESTERN RIDGE RETROGRADES. MODEL DISAGREE ON LOCATION OF MOIST AXIS TODAY...WITH GFS CLOSE TO BLUE RIDGE AND NAM E OF AREA. STARTED MORNING POPS WITH BEST CHANCE N AND W PER RADAR TRENDS...THEN SWITCHED AFTERNOON POPS TOWARD NAM POSITION OF MOISTURE...WHICH GFS TRENDS TOWARD BY MON. RAISED POP IN E TODAY TOWARD MET/FWC GUIDANCE...THOUGH STILL A BIT BELOW. MODELS AGREE ON MOISTURE SHIFTING S MON...AND LOWERED POPS TO LOW CHANCE MON AND MONDAY NIGHT. WILL CARRY SLIGHT CHANCE POPS TUE AND TUE NIGHT AS BETTER MOISTURE SHIFTS S OF AREA...AND ATMOSPHERE DRIES FROM TOP DOWN...BUT REMAINS MOIST AND MARGINALLY UNSTABLE AT LOW LEVELS. GRADUAL WARMING TREND AS HEIGHTS RISE AND CLOUD COVER DECREASES. WINDS TO STAY FROM NE OR E WITH SURFACE RIDGE ALONG E COAST. LONG TERM (WEDNESDAY THROUGH SATURDAY)... BOTH THE ETA AND GFS INDICATE A BROAD 500HPA TROUGH OVER THE EAST AT THE END OF THE WEEKEND WITH THE AXIS SLOWLY MOVING TOWARD THE EASTERN SEABOARD. BOTH INDICATE A VERY MOIST ATMOSPHERE TO THE EAST OF THIS AXIS WITH PRECIPITABLE WATER VALUES OVER TWO INCHES. THE GFS INDICATES A WEDGE-LIKE SIGNATURE IN THE INSTABILITY INDICES FOR SUNDAY AFTERNOON AND WITH A HIGH OVER THE NORTHEAST...THIS MAY SEEM REASONABLE. WITH THIS HIGH OVER THE NORTHEAST AND WEAK LOW PRESSURE TO THE SOUTH...AN EASTERLY FLOW WILL PREVAIL AT THE END OF THE WEEKEND AND START OF THE WEEK. THE ETA PROGRESSES THE UPPER TROUGH AXIS FASTER TO THE EAST WITH THE OFFSHORE HIGH WEAKENING. AS HAS BEEN COMMON...THE GFS HAS BEEN MORE DEPENDABLE SO WE EXPECT THIS PROGRESSION TO THE BE SLOWER RATHER THAN FASTER. THE WEAK SURFACE FRONT NEAR THE COAST WILL GRADUALLY DISSOLVE IN THE FIRST HALF OF THE WEEK. WEAK HIGH PRESSURE OVER THE MID ATLANTIC REGION WILL EXERT MORE OF AN INFLUENCE INTO MID WEEK AS POPS DECREASE OVERALL. WE HAVE MAINTAINED SOME DIURNAL POPS WITH EITHER SLIGHT OR LOW CHANCE POPS MAINLY IN THE SOUTH BUT MORE PRONOUNCED WITH THE HIGHER TERRAIN IN THE MID WEEK. WE WILL HAVE TO WATCH THE PROGRESS OF THE STRONG TROPICAL WAVE LOCATED NEAR AND TO THE EAST OF THE VIRGIN ISLANDS. THIS IS EXPECTED TO MOVE TO NEAR THE BAHAMAS BY MID WEEK AND BY LATE WEEK MAY BRING TROPICAL RAIN TO THE SOUTHEAST AGAIN. AVIATION... WITH E TO SE FLOW IN THE LOWEST 10 KFT ON THE VAD WIND PROFILE...PRECIPITATION HAS FANNED OUT ALONG THE UPSLOPE AREAS NEAR THE BLUE RIDGE. THIS WILL KEEP PRECIPITATION CHANCES UP AT KAVL THROUGH THE MORNING HOURS...WITH MUCH LESS CHANCE AT PIEDMONT TAF SITES. IFR CIGS WILL BE FEATURED THIS MORNING AT KAVL AND KGSP WHERE PRECIP HAS RECENTLY OCCURRED OR IS IMMINENT. MAINLY MVFR CIG AND VSBY EXPECTED FROM KAND TO KCLT...WITH CONDITIONS VERY SLOW TO IMPROVE TO VFR CIG THROUGHOUT AFTER NOON. WITH MOIST PROFILES...ADDITIONAL SHOWER DEVELOPMENT CANNOT BE RULED OUT AT ANY TIME. HOWEVER...WILL ADVERTISE NARROW WINDOW OF BEST CONVECTIVE CHANCES DURING MAXIMUM INSTABILITY LATE THIS AFTERNOON. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SHORT TERM...VAD sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 936 PM EDT SUN JUL 31 2005 .SHORT TERM (REST OF TONIGHT THROUGH MONDAY)... SHOWERS AND THUNDERSTORMS DIMINISHING HOWEVER LINGERING SHOWERS/STORMS OVER VIRGINIA COUNTIES HAVE LEAD TO SOME PROBLEMS WITH FLOODING. EXPECT MOST ACTIVITY WILL BE OVER BY 04Z. NO MAJOR CHANGES IN ZONES. UPDATE OUT SOON. && .PREVIOUS DISCUSSION... (ISSUED 738 PM EDT SUN JUL 31 2005) AVIATION... BASICALLY A REPEAT PERFORMANCE ON THE TAFS THIS EVENING AS LAST EVENING WITH SHOWERS AND STORMS SUBSIDING BY AROUND 03Z AND AREAS OF FOG DEVELOPING TOWARD MORNING. PREVIOUS DISCUSSION... (ISSUED 224 PM EDT SUN JUL 31 2005) SHORT TERM (REST OF TONIGHT)... FORECAST BASICALLY A REPEAT OF LAST NIGHT. MAV MOS CONTINUES TO HAVE A COLD BIAS OF ABOUT 3 DEGREES ON THE MINIMUM TEMPERATURES SO HAVE NUDGED THOSE UP. ONCE AGAIN MOISTURE IN AND JUST WEST OF MOUNTAINS WILL MEAN FOG THERE WITH DRY AIR/GROUND OHIO RIVER WEST KEEPING FOG OUT THERE. PREVIOUS DISCUSSION... (ISSUED 1258 PM EDT SUN JUL 31 2005) AVIATION... TONIGHT A REPEAT OF LAST NIGHT. FOG OVER AND ALONG WESTERN SLOPES OF MOUNTAINS LIFR DEVELOPING AFTER 06Z. VICINITY OHIO RIVER WEST SKC WITH NO SIGNIFICANT VSBY RESTRICTIONS DUE TO DRYER AIR AND GROUND CONDITIONS. PREVIOUS DISCUSSION... (ISSUED 1150 AM EDT SUN JUL 31 2005) LONG TERM (THURSDAY THROUGH SUNDAY)... HOT AND HUMID WX CONTS WED AND THURS WITH H8 TEMPS AROUND 20C. LONG RANGE GUIDANCE HAS FINALLY CAUGHT ON AS MAXT IS NOW PROGGED IN THE MID 90S FOR THE AFOREMENTIONED DAYS. MIXING LAYER INCREASES TO 6-7KFT...SO WOULDN'T BE SURPRISED TO SEE A FEW UPR 90S IN THE HTS AND DWU VCNTY GVN WE HAVE BEEN DRY FOR DECENT PERIOD OF TIME. WARMEST THIS SUMMER HAS BEEN 97F AT HTS AND THAT COULD BE IN JEOPARDY WED. ECMWF AND UKMET HAVE COME IN LINE TO THE GFS ENSEMBLES FM YDY WITH RESPECT TO BREAKING DOWN THE RIDGE ALLOWING A BAROCLINIC ZONE TO TRAVERSE LATE FRIDAY. H7 TEMP ADV REMAINS NEUTRAL...SO A CAP SHOULD KEEP THE AREA DRY THUR AFTN INTO MIDDAY FRIDAY UNTIL BOUNDARY APPCHS. GFS DOESN'T PROG MUCH INSTABILITY AHEAD OF THE FRONT...WHICH IS HARD TO BELIEVE GIVEN MID AND UPR LVL MSTR WL BE ON THE INC ALONG WITH SFC DWTPS AROUND 70F...THUS INSERTED TRW MENTION FRI AREA WIDE. CONT TRW VERBIAGE THROUGH THE NIGHT TIME HRS IN THE TUG BASIN AS ELEVATED INSTABILITY IS NOTED ON GFS FCST SOUNDINGS SINCE THE FRONT STALLS THERE OVERNIGHT. HIGH PRESSURE NOSES S FM LK ERIE SAT PUSHING DRY AIR IN FM N TO S. LLVL MSTR STAYS HIGH IN SRN MTNS...SO KEPT CLOUDS AND TEMPS DWN THERE...OTRW A SLIGHT COOL DOWN INTO THE MID 80S. ANOTHER H5 ANTICYCLONE BUILDS IN THE CENTRAL CONUS SUN AND WITH RESPECTIVE HGT RISES...MAXT ONCE AGAIN WL BE NR OR SURPASS 90F BY DAY 7. SFC HIGH POSITIONED IN NEW ENGLAND BRINGS LIGHT UPSLOPE FLOW TO THE BKW AREA...SO NUDGED THEM BELOW GUID. PREVIOUS DISCUSSION... (ISSUED 1123 AM EDT SUN JUL 31 2005) SHORT TERM (REST OF TODAY THROUGH TONIGHT)... LATEST SHORT TERM MODELS SHOW THE BEST CHANCE OF SHOWERS/THUNDERSTORMS IN THE EXTREME SOUTHEAST THIS AFTERNOON AND EVENING. HAVE ADDED A SLIGHT CHANCE ALSO IN THE SE OHIO AND NW WV IN THE VICINITY OF PKB TO PERRY COUNTY THIS EVENING BASED ON A 250 MB SHORT WAVE PASSING AT THAT TIME. WHILE THE CHANCES ARE LOW RIGHT NOW BOTH THE RUC AND WRF PICKED UP ON SOMETHING THERE SO THOUGHT IT WAS WORTH MENTION. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SHORT TERM...DB wv AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 738 PM EDT SUN JUL 31 2005 .AVIATION... BASICALLY A REPEAT PERFORMANCE ON THE TAFS THIS EVENING AS LAST EVENING WITH SHOWERS AND STORMS SUBSIDING BY AROUND 03Z AND AREAS OF FOG DEVELOPING TOWARD MORNING. && .PREVIOUS DISCUSSION... (ISSUED 224 PM EDT SUN JUL 31 2005) SHORT TERM (REST OF TONIGHT)... FORECAST BASICALLY A REPEAT OF LAST NIGHT. MAV MOS CONTINUES TO HAVE A COLD BIAS OF ABOUT 3 DEGREES ON THE MINIMUM TEMPERATURES SO HAVE NUDGED THOSE UP. ONCE AGAIN MOISTURE IN AND JUST WEST OF MOUNTAINS WILL MEAN FOG THERE WITH DRY AIR/GROUND OHIO RIVER WEST KEEPING FOG OUT THERE. PREVIOUS DISCUSSION... (ISSUED 1258 PM EDT SUN JUL 31 2005) AVIATION... TONIGHT A REPEAT OF LAST NIGHT. FOG OVER AND ALONG WESTERN SLOPES OF MOUNTAINS LIFR DEVELOPING AFTER 06Z. VICINITY OHIO RIVER WEST SKC WITH NO SIGNIFICANT VSBY RESTRICTIONS DUE TO DRYER AIR AND GROUND CONDITIONS. PREVIOUS DISCUSSION... (ISSUED 1150 AM EDT SUN JUL 31 2005) LONG TERM (THURSDAY THROUGH SUNDAY)... HOT AND HUMID WX CONTS WED AND THURS WITH H8 TEMPS AROUND 20C. LONG RANGE GUIDANCE HAS FINALLY CAUGHT ON AS MAXT IS NOW PROGGED IN THE MID 90S FOR THE AFOREMENTIONED DAYS. MIXING LAYER INCREASES TO 6-7KFT...SO WOULDN'T BE SURPRISED TO SEE A FEW UPR 90S IN THE HTS AND DWU VCNTY GVN WE HAVE BEEN DRY FOR DECENT PERIOD OF TIME. WARMEST THIS SUMMER HAS BEEN 97F AT HTS AND THAT COULD BE IN JEOPARDY WED. ECMWF AND UKMET HAVE COME IN LINE TO THE GFS ENSEMBLES FM YDY WITH RESPECT TO BREAKING DOWN THE RIDGE ALLOWING A BAROCLINIC ZONE TO TRAVERSE LATE FRIDAY. H7 TEMP ADV REMAINS NEUTRAL...SO A CAP SHOULD KEEP THE AREA DRY THUR AFTN INTO MIDDAY FRIDAY UNTIL BOUNDARY APPCHS. GFS DOESN'T PROG MUCH INSTABILITY AHEAD OF THE FRONT...WHICH IS HARD TO BELIEVE GIVEN MID AND UPR LVL MSTR WL BE ON THE INC ALONG WITH SFC DWTPS AROUND 70F...THUS INSERTED TRW MENTION FRI AREA WIDE. CONT TRW VERBIAGE THROUGH THE NIGHT TIME HRS IN THE TUG BASIN AS ELEVATED INSTABILITY IS NOTED ON GFS FCST SOUNDINGS SINCE THE FRONT STALLS THERE OVERNIGHT. HIGH PRESSURE NOSES S FM LK ERIE SAT PUSHING DRY AIR IN FM N TO S. LLVL MSTR STAYS HIGH IN SRN MTNS...SO KEPT CLOUDS AND TEMPS DWN THERE...OTRW A SLIGHT COOL DOWN INTO THE MID 80S. ANOTHER H5 ANTICYCLONE BUILDS IN THE CENTRAL CONUS SUN AND WITH RESPECTIVE HGT RISES...MAXT ONCE AGAIN WL BE NR OR SURPASS 90F BY DAY 7. SFC HIGH POSITIONED IN NEW ENGLAND BRINGS LIGHT UPSLOPE FLOW TO THE BKW AREA...SO NUDGED THEM BELOW GUID. PREVIOUS DISCUSSION... (ISSUED 1123 AM EDT SUN JUL 31 2005) SHORT TERM (REST OF TODAY THROUGH TONIGHT)... LATEST SHORT TERM MODELS SHOW THE BEST CHANCE OF SHOWERS/THUNDERSTORMS IN THE EXTREME SOUTHEAST THIS AFTERNOON AND EVENING. HAVE ADDED A SLIGHT CHANCE ALSO IN THE SE OHIO AND NW WV IN THE VICINITY OF PKB TO PERRY COUNTY THIS EVENING BASED ON A 250 MB SHORT WAVE PASSING AT THAT TIME. WHILE THE CHANCES ARE LOW RIGHT NOW BOTH THE RUC AND WRF PICKED UP ON SOMETHING THERE SO THOUGHT IT WAS WORTH MENTION. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ AVIATION...DB wv AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 224 PM EDT SUN JUL 31 2005 .SHORT TERM (REST OF TONIGHT)... FORECAST BASICALLY A REPEAT OF LAST NIGHT. MAV MOS CONTINUES TO HAVE A COLD BIAS OF ABOUT 3 DEGREES ON THE MINIMUM TEMPERATURES SO HAVE NUDGED THOSE UP. ONCE AGAIN MOISTURE IN AND JUST WEST OF MOUNTAINS WILL MEAN FOG THERE WITH DRY AIR/GROUND OHIO RIVER WEST KEEPING FOG OUT THERE. && .PREVIOUS DISCUSSION... (ISSUED 1258 PM EDT SUN JUL 31 2005) AVIATION... TONIGHT A REPEAT OF LAST NIGHT. FOG OVER AND ALONG WESTERN SLOPES OF MOUNTAINS LIFR DEVELOPING AFTER 06Z. VICINITY OHIO RIVER WEST SKC WITH NO SIGNIFICANT VSBY RESTRICTIONS DUE TO DRYER AIR AND GROUND CONDITIONS. PREVIOUS DISCUSSION... (ISSUED 1150 AM EDT SUN JUL 31 2005) LONG TERM (THURSDAY THROUGH SUNDAY)... HOT AND HUMID WX CONTS WED AND THURS WITH H8 TEMPS AROUND 20C. LONG RANGE GUIDANCE HAS FINALLY CAUGHT ON AS MAXT IS NOW PROGGED IN THE MID 90S FOR THE AFOREMENTIONED DAYS. MIXING LAYER INCREASES TO 6-7KFT...SO WOULDN'T BE SURPRISED TO SEE A FEW UPR 90S IN THE HTS AND DWU VCNTY GVN WE HAVE BEEN DRY FOR DECENT PERIOD OF TIME. WARMEST THIS SUMMER HAS BEEN 97F AT HTS AND THAT COULD BE IN JEOPARDY WED. ECMWF AND UKMET HAVE COME IN LINE TO THE GFS ENSEMBLES FM YDY WITH RESPECT TO BREAKING DOWN THE RIDGE ALLOWING A BAROCLINIC ZONE TO TRAVERSE LATE FRIDAY. H7 TEMP ADV REMAINS NEUTRAL...SO A CAP SHOULD KEEP THE AREA DRY THUR AFTN INTO MIDDAY FRIDAY UNTIL BOUNDARY APPCHS. GFS DOESN'T PROG MUCH INSTABILITY AHEAD OF THE FRONT...WHICH IS HARD TO BELIEVE GIVEN MID AND UPR LVL MSTR WL BE ON THE INC ALONG WITH SFC DWTPS AROUND 70F...THUS INSERTED TRW MENTION FRI AREA WIDE. CONT TRW VERBIAGE THROUGH THE NIGHT TIME HRS IN THE TUG BASIN AS ELEVATED INSTABILITY IS NOTED ON GFS FCST SOUNDINGS SINCE THE FRONT STALLS THERE OVERNIGHT. HIGH PRESSURE NOSES S FM LK ERIE SAT PUSHING DRY AIR IN FM N TO S. LLVL MSTR STAYS HIGH IN SRN MTNS...SO KEPT CLOUDS AND TEMPS DWN THERE...OTRW A SLIGHT COOL DOWN INTO THE MID 80S. ANOTHER H5 ANTICYCLONE BUILDS IN THE CENTRAL CONUS SUN AND WITH RESPECTIVE HGT RISES...MAXT ONCE AGAIN WL BE NR OR SURPASS 90F BY DAY 7. SFC HIGH POSITIONED IN NEW ENGLAND BRINGS LIGHT UPSLOPE FLOW TO THE BKW AREA...SO NUDGED THEM BELOW GUID. PREVIOUS DISCUSSION... (ISSUED 1123 AM EDT SUN JUL 31 2005) SHORT TERM (REST OF TODAY THROUGH TONIGHT)... LATEST SHORT TERM MODELS SHOW THE BEST CHANCE OF SHOWERS/THUNDERSTORMS IN THE EXTREME SOUTHEAST THIS AFTERNOON AND EVENING. HAVE ADDED A SLIGHT CHANCE ALSO IN THE SE OHIO AND NW WV IN THE VICINITY OF PKB TO PERRY COUNTY THIS EVENING BASED ON A 250 MB SHORT WAVE PASSING AT THAT TIME. WHILE THE CHANCES ARE LOW RIGHT NOW BOTH THE RUC AND WRF PICKED UP ON SOMETHING THERE SO THOUGHT IT WAS WORTH MENTION. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SHORT TERM...AAR wv AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 1258 PM EDT SUN JUL 31 2005 .AVIATION... TONIGHT A REPEAT OF LAST NIGHT. FOG OVER AND ALONG WESTERN SLOPES OF MOUNTAINS LIFR DEVELOPING AFTER 06Z. VICINITY OHIO RIVER WEST SKC WITH NO SIGNIFICANT VSBY RESTRICTIONS DUE TO DRYER AIR AND GROUND CONDITIONS. && .PREVIOUS DISCUSSION... (ISSUED 1150 AM EDT SUN JUL 31 2005) LONG TERM (THURSDAY THROUGH SUNDAY)... HOT AND HUMID WX CONTS WED AND THURS WITH H8 TEMPS AROUND 20C. LONG RANGE GUIDANCE HAS FINALLY CAUGHT ON AS MAXT IS NOW PROGGED IN THE MID 90S FOR THE AFOREMENTIONED DAYS. MIXING LAYER INCREASES TO 6-7KFT...SO WOULDN'T BE SURPRISED TO SEE A FEW UPR 90S IN THE HTS AND DWU VCNTY GVN WE HAVE BEEN DRY FOR DECENT PERIOD OF TIME. WARMEST THIS SUMMER HAS BEEN 97F AT HTS AND THAT COULD BE IN JEOPARDY WED. ECMWF AND UKMET HAVE COME IN LINE TO THE GFS ENSEMBLES FM YDY WITH RESPECT TO BREAKING DOWN THE RIDGE ALLOWING A BAROCLINIC ZONE TO TRAVERSE LATE FRIDAY. H7 TEMP ADV REMAINS NEUTRAL...SO A CAP SHOULD KEEP THE AREA DRY THUR AFTN INTO MIDDAY FRIDAY UNTIL BOUNDARY APPCHS. GFS DOESN'T PROG MUCH INSTABILITY AHEAD OF THE FRONT...WHICH IS HARD TO BELIEVE GIVEN MID AND UPR LVL MSTR WL BE ON THE INC ALONG WITH SFC DWTPS AROUND 70F...THUS INSERTED TRW MENTION FRI AREA WIDE. CONT TRW VERBIAGE THROUGH THE NIGHT TIME HRS IN THE TUG BASIN AS ELEVATED INSTABILITY IS NOTED ON GFS FCST SOUNDINGS SINCE THE FRONT STALLS THERE OVERNIGHT. HIGH PRESSURE NOSES S FM LK ERIE SAT PUSHING DRY AIR IN FM N TO S. LLVL MSTR STAYS HIGH IN SRN MTNS...SO KEPT CLOUDS AND TEMPS DWN THERE...OTRW A SLIGHT COOL DOWN INTO THE MID 80S. ANOTHER H5 ANTICYCLONE BUILDS IN THE CENTRAL CONUS SUN AND WITH RESPECTIVE HGT RISES...MAXT ONCE AGAIN WL BE NR OR SURPASS 90F BY DAY 7. SFC HIGH POSITIONED IN NEW ENGLAND BRINGS LIGHT UPSLOPE FLOW TO THE BKW AREA...SO NUDGED THEM BELOW GUID. PREVIOUS DISCUSSION... (ISSUED 1123 AM EDT SUN JUL 31 2005) SHORT TERM (REST OF TODAY THROUGH TONIGHT)... LATEST SHORT TERM MODELS SHOW THE BEST CHANCE OF SHOWERS/THUNDERSTORMS IN THE EXTREME SOUTHEAST THIS AFTERNOON AND EVENING. HAVE ADDED A SLIGHT CHANCE ALSO IN THE SE OHIO AND NW WV IN THE VICINITY OF PKB TO PERRY COUNTY THIS EVENING BASED ON A 250 MB SHORT WAVE PASSING AT THAT TIME. WHILE THE CHANCES ARE LOW RIGHT NOW BOTH THE RUC AND WRF PICKED UP ON SOMETHING THERE SO THOUGHT IT WAS WORTH MENTION. PREVIOUS DISCUSSION... (ISSUED 550 AM EDT SUN JUL 31 2005) AVIATION... DRY AIR REMAINS OVER WESTERN PORTIONS OF THE REGION...BUT LOTS OF LOW LEVEL MOISTURE REMAINS TO THE EAST. THIS HAS CREATED A RANGE OF CONDITIONS TONIGHT...FROM VFR CONDITIONS IN THE WEST...TO PATCHES OF DENSE FOG IN THE EAST. FOG WILL BE SLOW TO BREAK AGAIN THIS MORNING DUE TO LIGHT WINDS. A FEW SHOWERS/THUNDERSTORMS ARE POSSIBLE TODAY IN THE MOUNTAINS...OTHERWISE DRY WEATHER CAN BE EXPECTED. SOME HAZE COULD KEEP MVFR CONDITIONS DURING THE DAY IN THE EAST HOWEVER. EXPECT FOG AGAIN IN THE EAST SUNDAY NIGHT. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ AVIATION...AAR wv AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 1150 AM EDT SUN JUL 31 2005 .LONG TERM (THURSDAY THROUGH SUNDAY)... HOT AND HUMID WX CONTS WED AND THURS WITH H8 TEMPS AROUND 20C. LONG RANGE GUIDANCE HAS FINALLY CAUGHT ON AS MAXT IS NOW PROGGED IN THE MID 90S FOR THE AFOREMENTIONED DAYS. MIXING LAYER INCREASES TO 6-7KFT...SO WOULDN'T BE SURPRISED TO SEE A FEW UPR 90S IN THE HTS AND DWU VCNTY GVN WE HAVE BEEN DRY FOR DECENT PERIOD OF TIME. WARMEST THIS SUMMER HAS BEEN 97F AT HTS AND THAT COULD BE IN JEOPARDY WED. ECMWF AND UKMET HAVE COME IN LINE TO THE GFS ENSEMBLES FM YDY WITH RESPECT TO BREAKING DOWN THE RIDGE ALLOWING A BAROCLINIC ZONE TO TRAVERSE LATE FRIDAY. H7 TEMP ADV REMAINS NEUTRAL...SO A CAP SHOULD KEEP THE AREA DRY THUR AFTN INTO MIDDAY FRIDAY UNTIL BOUNDARY APPCHS. GFS DOESN'T PROG MUCH INSTABILITY AHEAD OF THE FRONT...WHICH IS HARD TO BELIEVE GIVEN MID AND UPR LVL MSTR WL BE ON THE INC ALONG WITH SFC DWTPS AROUND 70F...THUS INSERTED TRW MENTION FRI AREA WIDE. CONT TRW VERBIAGE THROUGH THE NIGHT TIME HRS IN THE TUG BASIN AS ELEVATED INSTABILITY IS NOTED ON GFS FCST SOUNDINGS SINCE THE FRONT STALLS THERE OVERNIGHT. HIGH PRESSURE NOSES S FM LK ERIE SAT PUSHING DRY AIR IN FM N TO S. LLVL MSTR STAYS HIGH IN SRN MTNS...SO KEPT CLOUDS AND TEMPS DWN THERE...OTRW A SLIGHT COOL DOWN INTO THE MID 80S. ANOTHER H5 ANTICYCLONE BUILDS IN THE CENTRAL CONUS SUN AND WITH RESPECTIVE HGT RISES...MAXT ONCE AGAIN WL BE NR OR SURPASS 90F BY DAY 7. SFC HIGH POSITIONED IN NEW ENGLAND BRINGS LIGHT UPSLOPE FLOW TO THE BKW AREA...SO NUDGED THEM BELOW GUID. && .PREVIOUS DISCUSSION... (ISSUED 1123 AM EDT SUN JUL 31 2005) SHORT TERM (REST OF TODAY THROUGH TONIGHT)... LATEST SHORT TERM MODELS SHOW THE BEST CHANCE OF SHOWERS/THUNDERSTORMS IN THE EXTREME SOUTHEAST THIS AFTERNOON AND EVENING. HAVE ADDED A SLIGHT CHANCE ALSO IN THE SE OHIO AND NW WV IN THE VICINITY OF PKB TO PERRY COUNTY THIS EVENING BASED ON A 250 MB SHORT WAVE PASSING AT THAT TIME. WHILE THE CHANCES ARE LOW RIGHT NOW BOTH THE RUC AND WRF PICKED UP ON SOMETHING THERE SO THOUGHT IT WAS WORTH MENTION. PREVIOUS DISCUSSION... (ISSUED 550 AM EDT SUN JUL 31 2005) AVIATION... DRY AIR REMAINS OVER WESTERN PORTIONS OF THE REGION...BUT LOTS OF LOW LEVEL MOISTURE REMAINS TO THE EAST. THIS HAS CREATED A RANGE OF CONDITIONS TONIGHT...FROM VFR CONDITIONS IN THE WEST...TO PATCHES OF DENSE FOG IN THE EAST. FOG WILL BE SLOW TO BREAK AGAIN THIS MORNING DUE TO LIGHT WINDS. A FEW SHOWERS/THUNDERSTORMS ARE POSSIBLE TODAY IN THE MOUNTAINS...OTHERWISE DRY WEATHER CAN BE EXPECTED. SOME HAZE COULD KEEP MVFR CONDITIONS DURING THE DAY IN THE EAST HOWEVER. EXPECT FOG AGAIN IN THE EAST SUNDAY NIGHT. PREVIOUS DISCUSSION... (ISSUED 350 AM EDT SUN JUL 31 2005) LONG TERM (TONIGHT THROUGH SATURDAY)... THE UPPER RIDGE TO THE WEST BUILDS EASTWARD ON MONDAY AND SHOULD REMAIN IN CONTROL OF THE OHIO VALLEY THROUGH MID WEEK. THIS SHOULD LEAD TO A FAIRLY PERSISTENT WEATHER PATTERN WITH DRY WEATHER AND SLIGHTLY ABOVE NORMAL TEMPERATURES EXPECTED. HAVE GENERALLY REMAINED ON THE HIGH SIDE OF THE TEMPERATURES LEANING TOWARD THE WARMER MET NUMBERS SINCE THE MAV NUMBERS HAVE BEEN VERIFYING TOO COOL. THE THING TO WATCH WILL BE SOME SHORTWAVE ENERGY ROTATING AROUND THE UPPER RIDGE THROUGH THE GREAT LAKES INTO PENNSYLVANIA. WHILE THE MOISTURE IS NOT ALL THAT PLENTIFUL BY SUMMER TIME STANDARDS...THE SHORTWAVE SHOULD CLIP THE NORTHERN PART OF THE REGION...ESPECIALLY THE NORTHERN MOUNTAINS WILL SOME CONVECTION EITHER MONDAY NIGHT OR TUESDAY DEPENDING UPON WHICH MODEL CHOSEN. BUT AT THIS TIME...STILL THINK ANY SHOWERS SHOULD REMAIN NORTH OF THE REGION. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ LONG TERM...29 wv AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 1123 AM EDT SUN JUL 31 2005 .SHORT TERM (REST OF TODAY THROUGH TONIGHT)... LATEST SHORT TERM MODELS SHOW THE BEST CHANCE OF SHOWERS/THUNDERSTORMS IN THE EXTREME SOUTHEAST THIS AFTERNOON AND EVENING. HAVE ADDED A SLIGHT CHANCE ALSO IN THE SE OHIO AND NW WV IN THE VICINITY OF PKB TO PERRY COUNTY THIS EVENING BASED ON A 250 MB SHORT WAVE PASSING AT THAT TIME. WHILE THE CHANCES ARE LOW RIGHT NOW BOTH THE RUC AND WRF PICKED UP ON SOMETHING THERE SO THOUGHT IT WAS WORTH MENTION. && .PREVIOUS DISCUSSION... (ISSUED 550 AM EDT SUN JUL 31 2005) AVIATION... DRY AIR REMAINS OVER WESTERN PORTIONS OF THE REGION...BUT LOTS OF LOW LEVEL MOISTURE REMAINS TO THE EAST. THIS HAS CREATED A RANGE OF CONDITIONS TONIGHT...FROM VFR CONDITIONS IN THE WEST...TO PATCHES OF DENSE FOG IN THE EAST. FOG WILL BE SLOW TO BREAK AGAIN THIS MORNING DUE TO LIGHT WINDS. A FEW SHOWERS/THUNDERSTORMS ARE POSSIBLE TODAY IN THE MOUNTAINS...OTHERWISE DRY WEATHER CAN BE EXPECTED. SOME HAZE COULD KEEP MVFR CONDITIONS DURING THE DAY IN THE EAST HOWEVER. EXPECT FOG AGAIN IN THE EAST SUNDAY NIGHT. PREVIOUS DISCUSSION... (ISSUED 350 AM EDT SUN JUL 31 2005) SHORT TERM (REST OF TODAY)... EXPECT VERY LITTLE MOVEMENT IN THE MOISTURE FIELD FOR TODAY. AVN HANDLING OF THE MOISTURE LOOKS A BIT BETTER THAN THE NAM...MORE IN LINE WITH CURRENT RADAR MOVEMENT. IF ANY MOVEMENT OCCURS...WOULD EXPECT IT TO BE SLIGHTLY SOUTHWESTWARD. BASED ON LOCATION OF PRECIPITATION ON SATURDAY...WILL KEEP A CHANCE OF AFTERNOON THUNDERSTORMS IN THE MOUNTAINS...HEDGING POPS A BIT MORE TOWARD THE SOUTHWEST. MAV MOS IS ONCE AGAIN COOLER THAN HIGHS ON PREVIOUS DAY...SO WILL GO ABOVE MAV MOS. LONG TERM (TONIGHT THROUGH SATURDAY)... THE UPPER RIDGE TO THE WEST BUILDS EASTWARD ON MONDAY AND SHOULD REMAIN IN CONTROL OF THE OHIO VALLEY THROUGH MID WEEK. THIS SHOULD LEAD TO A FAIRLY PERSISTENT WEATHER PATTERN WITH DRY WEATHER AND SLIGHTLY ABOVE NORMAL TEMPERATURES EXPECTED. HAVE GENERALLY REMAINED ON THE HIGH SIDE OF THE TEMPERATURES LEANING TOWARD THE WARMER MET NUMBERS SINCE THE MAV NUMBERS HAVE BEEN VERIFYING TOO COOL. THE THING TO WATCH WILL BE SOME SHORTWAVE ENERGY ROTATING AROUND THE UPPER RIDGE THROUGH THE GREAT LAKES INTO PENNSYLVANIA. WHILE THE MOISTURE IS NOT ALL THAT PLENTIFUL BY SUMMER TIME STANDARDS...THE SHORTWAVE SHOULD CLIP THE NORTHERN PART OF THE REGION...ESPECIALLY THE NORTHERN MOUNTAINS WILL SOME CONVECTION EITHER MONDAY NIGHT OR TUESDAY DEPENDING UPON WHICH MODEL CHOSEN. BUT AT THIS TIME...STILL THINK ANY SHOWERS SHOULD REMAIN NORTH OF THE REGION. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SHORT TERM...AAR wv AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREEN BAY WI 200 PM CDT SUN JUL 31 2005 .SHORT TERM...TNGT AND MONDAY...MAIN FCST CONCERNS ARE TSTM CHCS AND TEMPS. MID-AFTN SFC ANALYSIS SHOWS TROF FM KINL TO KHON...AND WRMFNT ACRS LS TO NRN LOWER MI. ALTHOUGH MDT INSTAB EXISTS ACRS MUCH OF FCST AREA...VRY LTL IN THE WAY OF MECHANISM TO LIFT PARCELS ATTM. EARLY AFTN TAMDAR SOUNDINGS AROUND ATW INDCT CAPPING INVERSION AND DRY LAYER AROUND 840-860 MB. 00Z NMM WRF...12Z NAM AND 15Z RUC DO INDCT INCREASED CHC FOR ISOLD-SCT CONVECTION BTWN 00Z-06Z ACRS NRN HALF OF FCST AREA AHD OF SFC TROF AND WK MID-LVL SHRTWV TROF. FCST TEMPS FOR TNGT AND MON A BLEND OF PERSISTENCE AND AVN MOS. .LONG TERM...MONDAY NIGHT INTO NEXT SUNDAY...BROAD UPPER RIDGE WILL CONTINUE TO DOMINATE THE MID SECTION OF THE COUNTRY DURING THIS PERIOD...WITH MORE OF A ZONAL FLOW NEAR THE US/CANADIAN BORDER. TIMING FRONTAL SYSTEMS ALONG WITH S/WS ON THIS NORTHERN PERIMETER WILL BE THE CHALLENGE FOR THE GREAT LAKES AREA. FOR MONDAY NIGHT...MODELS CONTINUE TO WASH OUT A SUBTLE SURFACE BOUNDARY OVER SOUTHERN WISCONSIN MONDAY NIGHT INTO TUESDAY AS A SURFACE HIGH PRESSURE REGION SLIDES OVER THE NORTHERN GREAT LAKES REGION. RETURN FLOW STARTS LATER TUESDAY NIGHT INTO EARLY WEDNESDAY AND GFS/NAM PROGGED PCPN TO SPREAD OVER. HOWEVER DUE TO RECENT TIMING CHALLENGES WITH S/WS AND DEALING WITH AN AIR MASS WHICH WARM AND RELATIVELY DRY IN RESPECT TO SATURATE...WILL CONTINUE A DRY FORECAST THROUGH WEDNESDAY. OTHERWISE NEXT CHANCE OF PCPN STILL FROM WED NIGHT INTO THURSDAY NIGHT AS UPPER TROUGH BREAKS DOWN THE UPER RIDGE AND FRONTAL SYSTEM SLIDES OVER THE AREA. GOING FORECAST LOOKS GOOD. BROAD UPPER RIDGE THEN AGAIN DEVELOPS FRIDAY INTO THE WEEKEND. SOME POTENTIAL OF ANOTHER S/W TROF TO AFFECT THE FORECAST AREA LATER SUNDAY BUT FOR NOW WILL CONTINUE THE DRY FORECAST. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ JKL/HELMAN WEATHER.GOV/GREENBAY wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND JUNCTION CO 415 AM MDT MON AUG 1 2005 .SHORT TERM (TODAY THROUGH TUESDAY NIGHT)... A SHORTWAVE TROUGH WILL TRAVEL NORTH ACROSS MOST OF THE CWA EARLY THIS MORNING. IT WILL SPAWN ISOLD-WDLY SCATTERED SHOWERS AND AN EMBEDDED TSTM OR TWO BEFORE IS EXIST INTO WYOMING ABOUT 9 AM. THE SITUATION DOESN'T LOOK LIKE IT WILL CHANGE ALL THAT MUCH OVER THE NEXT 48 HOURS. THE MONSOONAL PLUME LOOKS ALMOST STATIC IN THE MODELS AND WILL REMAIN DRAPED OVER THE AREA...ESPECIALLY AFFECTING EASTERN UT AND NW CO. THE RUC SHOWS A FEW MORE VORT MAXES OVER SRN AZ THAT WILL AFFECT EASTERN UT AND WESTERN CO LATER TODAY AND TONIGHT. BUMPED UP THE POPS ACROSS THE BOARD TODAY...BUT THE TRACE REPORTS IN THE RTP SHOW SIGNIFICANT RAIN SHOULD BE CONFINED TO ISOLATED AREAS AGAIN TODAY. PW ACTUALLY DECREASED ABOUT .16 INCH FROM THE 12Z TO 00Z SOUNDING. A LITTLE BIT OF DYNAMIC SUPPORT TODAY WILL HELP PRODUCE A COPY OF SUNDAY...BUT THIS ISN'T AS WET AS THE MONSOON CAN GET. WILL HAVE TO WATCH OUT FOR THOSE ISOLD AREAS OF SIGNIFICANT PRECIPITATION AS WE SAW SUNDAY. MODEL TIME/HEIGHTS DISPLAYS SHOW LESS DYNAMIC HELP TUE SO POPS TAIL OFF A LITTLE. TEMPS SHOULD CONTINUE THEIR SLOW DOWNTURN...THOUGH IT APPEAR MODELS ARE TOO COLD AGAIN TODAY. .LONG TERM (WEDNESDAY THROUGH SUNDAY)...ACTIVE MONSOONAL PATTERN THROUGH THE EXTENDED PERIOD...AT LEAST THROUGH NEXT FRIDAY. H7 MIXING RATIOS ON THE GFS AND NAM MODEL WILL RANGE FROM 6 TO 9 G/KG...SUGGESTING THAT THE SUBTROPICAL MOISTURE PLUME WILL POSITIONED OVER THE FORECAST AREA. FOR THE MOST PART...WINDS ALOFT WILL BE LIGHT AND THEREFORE STORMS WILL BE SLOW MOVERS WITH LOCAL AREAS OF HEAVY RAIN. THE EXCEPTION MAY OCCUR ON WEDNESDAY WHEN A TROUGH AXIS DRAGS ACROSS MONTANA AND NORTH DAKOTA. WIND SHEAR ABOVE 500 MB INCREASES WITH DIVERGENCE ALOFT. THEREFORE STORMS ACROSS THE NRN AREAS MAY SHOW BETTER ORGANIZATION AND BE LONGER LIVED. BY NEXT WEEKEND...THE GFS MODEL SHOWS ANOTHER SHORT WAVE PASSING THE AREA FRIDAY AFTERNOON AND NIGHT TIME FRAME WITH DRIER AIR BEHIND THE TROUGH AXIS. BUT NORTHWEST FLOW IS WEAK BEHIND THE TROUGH AXIS AND A CHANGE IN AIR MASS MAY BE LIMITED TO NE UTAH. THEREFORE "CHANCE" POPS WILL CONTINUE FOR SWRN COLORADO...BUT A TREND OF LOWER POPS ELSEWHERE WILL BE INDICATED FOR ERN UTAH AND NWRN COLORADO. && .GJT WATCHES/WARNINGS/ADVISORIES... .CO...NONE. .UT...NONE. && CJC/PF co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 500 AM EDT MON AUG 01 2005 .DISCUSSION...SFC MAP AT 03Z SHOWING WARM FRONT ACROSS NE LAKE HURON WITH A WEAK CIRCULATION IN EASTERN LAKE SUPERIOR AND ANOTHER IN FAR WESTERN LAKE SUPERIOR. IN BETWEEN THESE TWO SFC LOWS...A FRONTAL ZONE (ALBEIT WEAK) IS STRETCHED ACROSS UPPER MICHIGAN. STRONG TO SEVERE STORMS WERE FIRING ALONG THIS FRONTAL ZONE AND WERE MOVING SE AT ROUGHLY 30 MPH. SFC HIGH PRESSURE WAS NORTH OF THE OHIO RIVER VALLEY ASSOCIATED WITH THE DRIEST OF AIR. 00Z APX SOUNDING SHOWED THAT THUNDERSTORMS WERE NOT VERY FAR FROM POPPING WITH MINIMAL CAP LEFT. HOWEVER FROM 18Z-00Z...TEMPS AT 750MB ROSE FROM +8C TO +12C WHICH RESULTED IN THE CAP. THERE WAS 3000J/KG OF CAPE AVAILABLE WITH WET BULBS AROUND 11.8 KFT AND BULK SHEAR VALUES OF 35-40KTS. ANALYZING AREA ACARS SOUNDINGS...WE ONLY HAD 20J/KG OF CIN ACROSS EASTERN UPPER WITH 60J/KG ACROSS OUR EASTERN CWA SUGGESTING THAT STORMS COULD HAVE FIRED FURTHER SOUTH. HOWEVER...BOUNDARY THAT INITIATED THE STORMS HAS MADE IT ONLY TO MACKINAC COUNTY AND FAR NRN LAKE MICHIGAN. THE PRECIPITATION FROM EARLIER HAS OUTRUN THE BOUNDARY AND HEADED INTO A LESS FAVORABLE AIR MASS THAT COULD NOT SUSTAIN THEM. PLUS...THERE IS BASICALLY NO HELP AT H8...THEREFORE THE PRECIP HAS DIMINISHED. SYNOPTIC SETUP AND MODEL DISCUSSION...NAM WAS 2-3 DEGREES TOO COOL WITH THE TEMPERATURES AROUND THE CAP AT 00Z. GFS WAS MORE IN LINE. BOTH MODELS SHOW THE GENERAL TREND OF BRINGING SFC TROUGH AXIS OR WEAK COOL FRONT FROM THE WESTERN U.P. THROUGH THE STRAITS TO ROUGHLY ALPENA THIS MORNING...WHILE LATEST RUC SUGGESTS THAT THIS BOUNDARY WILL MOVE VERY LITTLE...AND HANG ACROSS EASTERN UPPER. FORECAST CONCERNS DEAL WITH PRECIP CHANCES THROUGH TUESDAY AND HOW WARM WE WILL GET...SAME AS LAST FEW DAYS. TODAY AND TONIGHT...MAIN QUESTION IS...HOW FAR SOUTH WILL THE FRONTAL ZONE GO AND HOW MUCH CONVERGENCE WILL IT HAVE? WITH BOUNDARY HANGING FURTHER TO THE NORTH...WILL BLEND WITH THE RUC AND GFS IDEA OF KEEPING IT ACROSS THE STRAITS REGION TODAY...BUT CONVERGENCE BECOMES RATHER MEAGER WITH IT WASHING OUT WHILE SFC HIGH PRESSURE MOVES IN FROM THE WEST. STILL HAVE AN AXIS OF HIGHER THETA-E AIR ALONG THIS BOUNDARY WITH A DEGREE OR TWO OF COOLING NOTED IN THE 700-750MB LAYER (WHERE CAP WAS AT 00Z YESTERDAY). H8 WINDS WILL BE LESS TODAY (10-15KTS)...SUPPORTING LAKE BREEZES MOST ALL NEARSHORE AREAS. OVERALL SW GRADIENT FLOW SUPPORTS BEST CONVERGENCE THIS AFTERNOON ACROSS THE SE CWA. MODIFYING SOUNDINGS REVEAL 1000J/KG ACROSS EASTERN UPPER TODAY WITH AS MUCH AS 2200J/KG IN THE SE CWA WITH CONVECTIVE TEMPS IN THE 85-89F RANGE. DO BELIEVE WE'LL SEE SCATTERED CONVECTION DEVELOP MAINLY EAST OF I-75 IN NRN LOWER...AND MACKINAC COUNTY IN EASTERN UPPER. SLIGHT CHANCE EXISTS FOR INLAND CHIPPEWA COUNTY WHERE LAKE BREEZE BOUNDARY MAY BE VIGOROUS ENOUGH TO FIRE OFF ACTIVITY. BULK SHEAR RATHER MINIMAL AT 20-25KTS SO STORM ORGANIZATION NOT AS LIKELY AS LAST NIGHT. COULD NOT RULE OUT ONE OR TWO STORMS GETTING A STRONG ENOUGH UPDRAFT FOR LARGE HAIL/DAMAGING WINDS...BUT OVERALL SEVERE THREAT IS MINIMAL. ANY AFTERNOON CONVECTION WILL DISSIPATE RATHER QUICKLY EARLY THIS EVENING...AND WITH ANTICYCLONIC H8 FLOW AND NO OTHER DYNAMICAL HELP ALOFT FORESEEN...WILL CONTINUE WITH A PRECIP FREE FORECAST. AXIS OF THETA-E AIR REMAINS/LIFTS SLOWLY BACK TO THE NORTH AND WILL BE THE AREA TO WATCH IF ANYTHING DOES DECIDE TO DEVELOP. HIGHS TODAY WITH SIMILAR H8 TEMPS AND GOOD SOLAR HEATING WILL MAKE IT INTO THE MID AND UPPER 80S...AND WITH TD'S IN THE MIDDLE 60S...LOWS OVERNIGHT WILL RANGE IN THE LOWER TO MIDDLE 60S. TUESDAY AND TUESDAY NIGHT...WILL STAY RATHER WARM...H8 TEMPS RISE TO 19C OR SO...AND SFC TEMPS WILL MAKE IT INTO THE UPPER 80S AND LOWER 90S. DO NOT KNOW HOW MUCH STOCK CAN BE PLACED INTO GFS COOLING SEEN AROUND H7 IN A PATTERN WHERE H5 HEIGHTS ARE RISING. NEVERTHELESS... STEEPER LAPSE RATES BETWEEN H8-H7 SEEN...AND MODIFIED SOUNDINGS SHOWING THAT CONVECTIVE TEMPS WILL BE REACHED/CAP ERODED. THIS USING A PARCEL OF 88/65 AND GETTING CAPES TO 1800 TO 2000J/KG...MAINLY FOR AREAS SOUTH OF A HTL-APN LINE. HAVE INTRODUCED A 20% POP FOR THIS AREA BUT WILL ALSO HAVE TO MONITOR AREAS AWAY FROM MARINE INFLUENCE DOWNWIND OF LAKES (IN SW FLOW)...SUCH AS CHIPPEWA COUNTY WHERE CIN IS ONLY 20-30J/KG. LAKE BREEZES THIS DAY AS WELL AND COULD BE A FOCUS FOR THUNDERSTORM DEVELOPMENT. HAVE HELD OFF ON INTRODUCING POPS THERE ATTM. AGAIN...ANY ACTIVITY WILL QUICKLY DISSIPATE IN THE EARLY EVENING...RESULTING IN PARTLY CLOUDY TO MOSTLY CLEAR SKIES. MIN TEMPS LOOK TO FALL INTO THE MIDDLE AND UPPER 60S. NO OTHER CHANGES...WARM TEMPS UNTIL THURSDAY AFTERNOON/EVENING WHEN COLD FRONT SWEEPS THROUGH NRN MICHIGAN. SMD && .APX...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 400 AM EDT MON AUG 1 2005 .SHORT TERM...TODAY AND TONIGHT MODELS IN FAIRLY GOOD CONSENSUS DEPICTING SURFACE COLD FRONT OVER NORTHERN LAKES REGION PRETTY MUCH WASHING OUT AS IT SLICES SOUTHEAST TODAY INTO TONIGHT...WHILE AT 500 MB HEIGHTS TENDING TO SLOWLY RISE THROUGH TONIGHT. VIGOROUS CONVECTION EARLIER ALONG NORTHERN FRONT HAS WEAKENED CONSIDERABLY WHILE SETTLING SOUTHWARD...AS ASSOCIATED CLOUDINESS/CONVECTIVE DEBRIS EXTENDS DOWN INTO NORTHERN PART OF FORECAST AREA. EXPECT THIS CLOUD COVER TO SHOW A STEADY THINNING TREND EARLY THIS MORNING...ALREADY UNDERWAY AS PER WARMING IR TOPS IN SATELLITE IMAGERY. WILL CONFINE CONVECTION MENTION TO SLIGHT CHANCE SAGINAW VALLEY AND THUMB THIS AFTERNOON...SUPPORTED BY RUC13 AND WRFXX...AS DAYTIME HEATING HAS A CHANCE TO WORK WITH WHAT IS LEFT OF COLD FRONT...WITH ESPECIALLY NAM DEPICTING QUITE UNSTABLE AFTERNOON CONDITIONS AND K INDICES TO AT LEAST 30...WITH FAIRLY STEEP 850 TO 700 MB LAPSE RATES. MOISTURE...LIMITED AS IT IS...WILL ALSO BE BEST IN THE NORTHERN COUNTIES OF SOUTHEAST MI. DYNAMICS WEAK THIS AFTERNOON AS WELL...IN TERMS OF OCCASIONAL WEAK LOW TO MID LEVEL OMEGA LIFT...SLIGHT 850 TO 500 MB QVECTOR CONVERGENCE AND SLIGHT SURFACE WIND CONVERGENCE. IN SOUTHERN ZONES...HIGH PRESSURE EXPECTED TO BE MORE IN CONTROL...AND ANY CHANCES OF CONVECTION TODAY TOO ISOLATED FOR FORECAST MENTION. AM GOING CLOSE TO GUIDANCE TEMPERATURES THROUGH TONIGHT...AS BOTH NAM AND NGM T1 TEMPERATURES ARE 3 TO 4 DEGREES CELSIUS WARMER THAN YESTERDAY...BRINGING MAXIMUM TEMPERATURES UP TO CLOSE TO 90 TODAY. && .LONG TERM... DIFFERENCES ARISE BETWEEN THE NAM/GFS TUESDAY/WEDNESDAY...MAINLY WITH RESPECT TO CONVECTIVE DEVELOPMENT AND EVOLUTION UPSTREAM ACROSS THE WESTERN GREAT LAKES. HAVE NOT BEEN TOO IMPRESSED WITH THE WAY THE NAM HAS HANDLED CONVECTION RECENTLY. IN ADDITION...LOCAL WRF-XX OFFERS A SCENARIO SOMEWHAT SIMILAR TO THE GFS. AT THIS POINT WILL CONTINUE TO LEAN TOWARD THE GFS SOLUTION...WHICH IS DRIER THROUGH MID WEEK. ADDITIONAL DIFFERENCES BECOME APPARENT WITH THE APPROACHING COLD FRONT LATE IN THE WEEK /ALTHOUGH THE TIMING HAS BECOME INCREASINGLY NOT AS LATE IN THE WEEK GIVEN MODEL TRENDS OVER THE PAST FEW DAYS/. GFS HAS BEEN MORE CONSISTENT OVER THE LAST COUPLE RUNS...AND AGAIN HAS SUPPORT FROM OTHER EXTENDED MODELS. WEAK BOUNDARY LINGERS ACROSS THE CENTRAL GREAT LAKES...WITH HIGH PRESSURE OVER THE GREAT LAKES AND RIDGE EXTEND NORTHWARD ACROSS THE REGION. DECENT CAP APPARENT ON FORECAST SOUNDINGS...ESPECIALLY TOWARD THE SOUTHWEST CLOSER TO THE UPPER HIGH. MAIN AREA IN QUESTION FOR POPS IS ACROSS THE NORTHERN CWA/THUMB OUT INTO LAKE HURON...CLOSER TO THE WEAK TROUGH AND FARTHER AWAY FROM THE CWA. TEMPERATURES STILL LOOK GOOD IN THE UPPER 80S/LOW 90S. GRADIENT FLOW REMAINS OUT OF THE WEST ACROSS LOWER MICHIGAN...WHICH WITH A LARGE LAND/LAKE DELTA-T COULD LEAD TO MORE OF A TRUE UPRIGHT LAKE BREEZE CIRCULATION ACROSS THE THUMB...WHICH MAY ALSO AID CONVECTIVE POTENTIAL. DIFFERENCE BETWEEN TODAY AND TUESDAY IS WITH SYNOPTIC LIFT...AS WEAK 850-500MB QVECTOR CONVERGENCE WILL BECOME NEUTRAL BY TUESDAY AFTERNOON. AT THIS POINT WILL STICK WITH THE DRY FORECAST...ALTHOUGH A SLIGHT CHANCE MAY BE NECESSARY. NAM IS THE MOST AGRESSIVE SWINGING MCS REMNANTS ACROSS LOWER MICHIGAN TUESDAY NIGHT/WEDNESDAY. AS MENTIONED ABOVE...NAM HAS BEEN OVERDONE WITH THIS TYPE OF PATTERN RECENTLY. GFS INDICATES DEVELOPMENT FARTHER WEST...WHICH SEEMS MORE REASONABLE GIVEN THE PLACEMENT OF THE LOW-LEVEL JET. ACTIVITY SHOULD WEAKEN BEFORE REACHING SOUTHEAST MICHIGAN...AND WILL STICK WITH A DRY FORECAST FOR NOW. NAM IS MUCH WARMER THAN THE GFS/WRF-XX WITH 850MB TEMPS ON WEDNESDAY. FEEL THAT GFS MAY BE TOO COOL...DUE TO CONVECTIVE FEEDBACK FROM COMPLEXES UPSTREAM. WILL STICK WITH MORE OF A MIDDLE OF THE ROAD SOLUTION...KEEP TEMPERATURES SIMILAR TO THOSE ON TUESDAY...GENERALLY IN THE LOW 90S. AS MENTIONED ABOVE...GFS HAS BEEN MORE CONSISTENT THAN THE ETA WITH THE SPEED OF THE NEXT FRONT. ACTUALLY...WILL LEAN TOWARD THE SIMILAR WRF-XX AS IT HAS A TIGHTER SURFACE REFLECTION NOT AS CONTAMINATED BY GRIDSCALE CONVECTIVE DEVELOPMENT. CURRENT RUNS BRING THE THROUGH THURSDAY AFTERNOON/EVENING...WITH HIGH PRESSURE BUILDING IN BY FRIDAY. ADJUSTED TIMING ON THE FRONT SIDE A BIT...BRINGING IN A CHANCE TSRA ACROSS THE CWA THURSDAY AFTERNOON. GRIDS STILL LOOK GOOD ON THE BACK SIDE...STILL KEEPING A CHANCE INTO FRIDAY MORNING TO COVER TIMING UNCERTAINTIES. WILL STICK WITH A FLAT 30 PERCENT AT THIS POINT. OVERALL EVENT LOOKS WORTHY OF A HIGHER POP...BUT WILL STICK WITH 30 FOR NOW GIVEN THE BORDER PERIOD TIMING ISSUES AS WELL AS THE OVERALL SPEED/TIMING TRENDS WITH THE SYSTEM. ATMOSPHERE DRIES OUT AND TEMPERATURES COOL BACK TO NEAR/JUST BELOW NORMAL BY THE WEEKEND. && .AVIATION... ISSUED 102 AM EDT MON AUG 1 2005 SURFACE HIGH PRESSURE CENTERED JUST SOUTH OF THE STATE CONTINUES TO PROVIDE VFR CONDITIONS ACROSS SOUTHEAST MICHIGAN. A FRONTAL BOUNDARY THAT EXTENDS ACROSS UPPER MICHIGAN HAS BEEN THE FOCUS FOR CONVECTION ACROSS THE UP AND LOCATIONS NORTH AND EAST OF LAKE HURON THIS EVENING. MOST OF THE MID LEVEL LIFT AND MOISTURE CONVERGENCE WILL REMAIN ACROSS THE UP AND NORTHERN LOWER MI THROUGH MOST OF THE NIGHT. BASED ON THE THICKNESS PATTERN... CONVECTION ACROSS UPPER MICHIGAN SHOULD SINK SOUTH DURING THE NIGHT. WITH SOME DRYER MID LEVEL AIR OVER SOUTHEAST MICHIGAN AND WEAKER FORCING... EXPECT THE CONVECTION WILL WEAKEN AS IT HEADS SOUTH ACROSS NORTHERN LOWER MI. THINK THAT JUST SOME MID LEVEL DEBRIS WILL MAKE IT INTO MBS AND POSSIBLY FNT LATE TONIGHT. WILL HAVE TO MONITOR THIS SYSTEM THROUGH THE NIGHT IN CASE AN AMENDMENT IS NEEDED TO ADD PRECIP TO MBS. THE FRONTAL BOUNDARY WILL SINK SOUTH ACROSS LOWER MICHIGAN ON MONDAY. FORCING ALONG THE BOUNDARY IS EXPECTED TO WEAKEN. IN FACT...THE LATEST 00Z GUIDANCE SUGGESTS THE BOUNDARY WILL STRUGGLE TO MAKE IT INTO THE SAGINAW VALLEY IN THE AFTERNOON AS HIGH PRESSURE REMAINS IN PLACE JUST SOUTH OF THE STATE LINE. THUS VFR CONDITIONS ARE EXPECTED THROUGH THE DAY MONDAY. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MI WATERS OF LAKE ERIE...NONE. && $$ SHORT TERM...DWD LONG TERM....BRAVENDER mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO 308 AM CDT MON AUG 01 2005 .DISCUSSION... NOT MANY CHANGES TO MAKE IN THE SHORT RANGE FORECAST. STILL UNDER THE INFLUENCE OF UPPER LEVEL RIDGING THROUGH THE MIDDLE OF THE WEEK. TEMPERATURES THIS AFTERNOON SHOULD BE AT OR SLIGHTLY ABOVE THOSE OF YESTERDAY. WITH THE EXCEPTION OF NORTHEASTERN MO...WHICH HAD A LOT OF CLOUD COVER/SCATTERED SHOWERS YESTERDAY...SO THIS AREA WILL BE NEARLY 10 DEG WARMER TODAY. MODELS ADVERTISE ANOTHER WEAK WAVE TO RIDE OVER THE RIDGE TONIGHT. THE LLVL JET SEEMS TO FOCUS MOST OF THE ENERGY JUST NORTH OF OUR CWA...SO HAVE NOT ACCOUNTED FOR ANY SENSIBLE WX IN THE GRIDS. TEMPS CONTINUE TO TREND HOTTER AS THE WEEK GOES BY. HAVE KEPT DROPPING DPTS IN THE THE SOUTHEASTERN COUNTIES...AS THEY KEEP MIXING OUT IN THE MID/LATE AFTN. THE BIGGEST CHANGE WAS MADE IN THE THURS/FRI TIMEFRAME. MODELS HAVE SPED UP THE FRONT FOR THIS TIME PERIOD...SO HAVE TRENDED FORECAST IN THAT DIRECTION. THIS WILL AFFECT WED HIGHS BY PUTTING A NICE THERMAL RIDGE AHEAD OF THE FRONT...SO HAVE GONE A LITTLE WARMER. HAVE ALSO GONE WARMER IN THE SOUTHERN COUNTIES WED NIGHT. ATTM MODELS DO NOT SHOW A LOT OF CONVERGENCE AS THE FRONT GOES THROUGH...AND NOW LOOKS LIKE IT MAY START INTO THE NORTHWEST CORNER EARLY THURS MORNING...ALSO NOT A FAVORABLE TIME OF DAY. TAKE THAT WITH THE MAIN SYSTEM PRETTY FAR NORTH...AND WE KEEP POPS IN THE VERY LOW CHANCE CATEGORY FOR NOW. 27 && .PREVIOUS DISCUSSION... 530 PM SUN... I HAVE ADDED SOME SHOWER AND EMBEDDED THUNDERSTORMS TO THE EARLY EVENING FORECAST FOR THE KIRKSVILLE, MACON, AND LANCASTER AREAS IN NORTHEAST MISSOURI. WATER VAPOR IMAGERY AND LOCAL WIND PROFILERS INDICATE A PRONOUNCED VORTICITY MAXIMA MOVING THROUGH CENTRAL IOWA. RUC SOUNDINGS SUGGEST THAT MOISTURE AND INSTABILITY ARE ABOVE 700 MB. THE RUC SUGGESTS THAT AS THE SHORTWAVE IN IOWA DRIFTS SOUTHEAST THIS EVENING THETA-E ADVECTION AT THE 700 MB LEVEL WILL DIMINISH, AND I WOULD ANTICIPATE A DECREASE IN CONVECTIVE ACTIVITY AFTER 02 OR 03 UTC. KOCH 214 PM SUN... VORT MAX OVER SOUTHERN IOWA CONTINUES TO GENERATE WIDELY SCATTERED ELEVATED CONVECTION ACROSS NORTHERN MISSOURI THIS AFTERNOON. ANTICIPATE THIS ACTIVITY TO CONTINUE WEAKENING DURING THE LATE AFTERNOON HOURS AS THE MAIN SHORTWAVE ENERGY SHIFTS TO THE EAST. OTHERWISE...UPPER LEVEL RIDGING WILL CONTINUE TO INFLUENCE THE WESTERN HALF OF THE NATION THROUGH THE FIRST PART OF THE UPCOMING WEEK. CANNOT ENTIRELY RULE OUT A FLEETING CHANCE AT PRECIPITATION OVER THE NEXT COUPLE OF DAYS AS WEAK WAVES TOP THE UPPER RIDGE...ALTHOUGH BOTH NAM AND GFS SOLUTIONS KEEP THE MINOR IMPULSES OUTSIDE OF THE FORECAST AREA. HAVE ONLY MADE MINOR TWEAKS TO TEMPERATURES...WITH AN ABOVE NORMAL REGIME CONTINUING. FOR THE MIDDLE OF THIS WORK WEEK AND THROUGH THE WEEKEND THE GENERAL PATTERN WILL UNDERGO A BIT OF A CHANGE AS THE DOMINATE RIDGE IS PUSHED BACK TO THE WEST BY SEVERAL TROUGHS MOVING THROUGH CANADA. THE FIRST WAVE WILL PUSH THROUGH TOWARDS THE HUDSON BAY THURSDAY...PUSHING A COLD FRONT SOUTH INTO KANSAS AND MISSOURI THURSDAY NIGHT. GIVEN HOW FAR NORTH THIS SYSTEM IS...THE COLD POOL PUSH BEHIND THE FRONT SHOULD BE FAIRLY WEAK. MID RANGE MODELS SEEM TO AGREE ON THIS AS THEY DISPLAY THE BAROCLINICITY DECREASING ALONG THE TRAILING EDGE OF THE FRONT THAT IS PROGGED TO SINK INTO OUR AREA. HOWEVER...STILL THINK THE TAIL OF THE FRONT SHOULD HAVE ENOUGH FORCING TO WARRANT CHANCE POPS AS IT MOVES THROUGH THURSDAY NIGHT. TEMPERATURES SHOULD MODERATE INTO THE 80S FOR FRIDAY AND SATURDAY...RANGING AT OR JUST BELOW NORMAL. NEXT TROUGH TO MOVE THROUGH CANADA IS CURRENTLY PROGGED TO TRACK A LITTLE FARTHER SOUTH...POSSIBLY GIVING US ANOTHER CHANCE FOR RAIN ON THE OTHER SIDE OF NEXT WEEKEND. SCHMIT/CUTTER && .EAX WATCHES/WARNINGS/ADVISORIES... KS...NONE. MO...NONE. $$ WFO EAX mo AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BINGHAMTON NY 330 AM EDT MON AUG 1 2005 .SHORT TERM (TODAY THROUGH TUESDAY)... COMPLEX YET SUBTLE PTRN DETERMINING THE DVLPMT AND CONTINUATION OF CONV ELEMENTS. THIS MRNG...MESOSCALE TROF...RDG...TROF SFC SETUP. MCC OVER NRN MI AND SE ONTARIO HAS BEEN DROPPING INTO THE STUBBORN MESO RDG OVER WRN NY AND ERODING. BOTH THE LATEST RUC AND NAM RUNS SHOW THIS FEATURE HOLDING FAST AND KEEPING THIS CONV WELL NORTH OF THE FCST AREA. HWVR...BOTH CONT TO SHOW CONV ALONG THE WEAK SFC TROF/BNDRY OVER CNTRL AND ERN NY AND NRN PA. STILL THE PSBLTY THAT SOMETHING COULD DVLP...BUT BNDRY/S BEEN QUIET THRU THE NGT. BNDRIES ARE SO WEAK...THERE DFCLT TO TRACK BUT IT SEEMS AS THOUGH YET ANOTHER...OR THE SAME...OLD BNDRY SETTLES SWRD LTR THIS AFTN AND FEED ON THE GNRL INSTABILITY TO DVLP MORE TRWS. XPCT CONV TO DVLP OVER CNTRL NY THIS AFTN AND SETTLE INTO NRN PA THIS EVE. SOME BORDERLINE SVR WX SUN AFTN...AND SOME PSBL AGAIN TODAY. WIND FIELDS ARE SLGTLY MORE IMPRESSIVE...ESP OVER NY...SO SOME ISLTD WIND DAMAGE RPTS PSBL. ACTIVITY SHD TAPER OFF QUICKLY THIS EVE AND OVRNGT HRS SHD BE DRY AS THE AIRMASS STABILIZES. GNRLY STABLE ON TUE HGTS BLD. NAM SHOWS A WEAK SHRT WV DROPPING THRU THE RDG AND WEAKENS THE CAPPING OVER PA AND XTRM WRN NY. SEEMS LIKE ANY PSBLTY OF TRWS OVER THE FCST AREA IS LIMITED...BUT WILL NOT ADJUST CRNT FCST OF LOW CHANCE POPS OVER THE XTRM SW. THAT AREA WLD HAVE THE BEST CHANCE. MINOR TWEAKS OF TEMPS AND POPS TO FIT LATEST MODEL AND MOS CONSENSUS...OTRW NO MAJOR CHGS TO THE FCST THIS UPDATE. MORFORD && .LONG TERM (TUESDAY NIGHT - MONDAY)... ON WRN EDGE OF UL TROF IN NW ATLANTIC SO NW FLOW ALOFT AND NEAR NORMAL TEMPERATURES THROUGH THE FIRST HALF OF EXTENDED. WEAK FORCING COULD SET OFF SOME SHOWERS BUT LEFT OUT AS SURFACE HIGH BUILDS IN WEDNESDAY THEN THU PULLS OFF THE EAST COAST AND RIDGING ALOFT. WITH SW FLOW THU INTO FRI HUMIDITY AND A TAD MORE HEAT WILL RETURN AHEAD OF SECOND COLD FRONT FRI NIGHT. THIS FRONT HAS MORE PUSH WITH A WEAK UL TROF...JET AND SHORT WAVE. QUESTION IS ABOUT TIMING WITH A FEW MODELS INCLUDING DGEX A FEW HOURS FASTER. THIS WOULD MEAN MORE CLOUDS AND LESS HEATING. AS HAS BEEN THE CASE LATELY FRONT EXPECTED TO MAKE GOOD PROGRESS OUT OF ONTARIO AND THROUGH NY THEN STALLS IN PA. LINGERING CHANCES OF PRECIP INTO SAT NGT BEFORE CANADIAN HIGH PRESSURE BUILDS IN SUNDAY. FOLLOWED HPC GUIDANCE CLOSELY. -TAC && .AVIATION (01/06Z - 02/06Z) SOME LGT FOG THIS MRNG RESULTING IN MVFR CONDS SOME STATIONS. ANY IFR CONDS SHD BE BRIEF. VFR CONDS SHD RULE THE REMAINDER OF THE FCST PD. SCT CONV WILL LIKELY DVLP THIS AFTN WITH GUSTY WINDS AND BRIEFLY LWR CONDS. && .BGM WATCHES/WARNINGS/ADVISORIES... .NY...NONE. .PA...NONE. && $$ ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSONVILLE FL 1021 AM EDT MON AUG 1 2005 .UPDATE...ATMOSPHERE IS QUITE JUICY WITH PWATS AROUND 2 INCHES THIS MORNING. COVERAGE OF PRECIP THIS AFTN IS EXPECTED TO BE ABOUT THE SAME AS YESTERDAY AND WILL NOT MAKE ANY CHANGES TO THE LIKELY POPS. CONVECTION WILL BEGIN WHEN TEMPS REACH MID/UPPER 80S. THE RUC INDICATES STORMS WILL FIRE EARLY ALONG THE SEABREEZES MOVING IN FROM THE NE GULF AND ALSO NEAR I-95. A NORTHEASTWARD MOTION WILL BRING STORMS TO THE EAST COAST THROUGH THE AFTN. WILL BE MAKING NO CHANGES EXCEPT TO REFRESH THE WORDING IN THE FORECAST. && .MARINE...NO HEADLINES. WINDS HAVE DECREASED TO LESS THAN 10 KNOTS UNDER A WEAK PRESSURE PATTERN. && .JAX WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. MARINE...NONE. && $$ MKT/JD/JB fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 955 AM EDT MON AUG 1 2005 .SHORT TERM (REST OF TODAY)... SFC ANALYSIS SHOWS HIGH PRESSURE OVER THE CWA. LAST NIGHT WAS CONDUCIVE FOR FOG DEVELOPMENT...ESPECIALLY WEST...HOWEVER VISIBILITIES CONTINUE TO IMPROVE ABOVE DENSE FOG ADVISORY CRITERIA AND NPW FOR DENSE FOG ADVISORY HAS BEEN ALLOWED TO EXPIRE. REST OF THE DAY WILL ALLOW SUNSHINE TO MIX WITH CLOUDS. BUFKIT SHOWS CU DEVELOPMENT AROUND 4-5K FT...SO PARTLY CLOUDY WORDING WILL WORK FINE. RUC AND GFS EVEN IMPLY A STRAY SHOWER OR THUNDERSTORM ACROSS OUR IMMEDIATE SOUTHWEST. INSERTED A 20 POP THERE FOR LATE AFTERNOON CONVECTION...OTHERWISE NO OTHER CHANGES MADE. PRODUCTS ALREADY RELEASED. && .AVIATION... VISIBILITIES/CEILINGS CONTINUE TO IMPROVE AS FOG/STRATUS LIFT. CONDITIONS GENERALLY WILL IMPROVE TO VFR BY 14-15Z ACROSS ALL TERMINALS...ALTHOUGH A LITTLE HAZE COULD LIMIT VISIBILITIES INTO MVFR AT TIMES. MAY HAVE TO DEAL WITH VISIBILITIES DOWN TO AT LEAST IFR AGAIN LATER TONIGHT/EARLY TUESDAY. && .MARINE... QUIET ON THE WATERS. NO FLAGS...WITH A DOMINANT EASTERLY WIND COMPONENT THIS AFTERNOON...AT 5 TO 10 KT. && .PREVIOUS DISCUSSION... (ISSUED 625 AM EDT MON AUG 1 2005) SHORT TERM...TODAY AND TONIGHT... IR SAT IMAGERY EARLY THIS MORNING SHOWS AN AREA OF CLEAR SKIES IN THE LOWER OH VALLEY HAS PROGRESSED ACROSS THE CWA FROM NORTHWEST TO SOUTHEAST. WITH SFC DEWPOINTS STILL IN THE MID 60S TO AROUND 70 ACROSS THE REGION...FOG HAS DEVELOPED AS TEMPERATURES HAVE FALLEN TO WITH 1 TO 3 F OF THE DEWPOINTS THROUGH 05Z. WILL INCLUDE AREAS OF DENSE FOG THIS MORNING FOR THE CWA WEST OF THE BLUE RIDGE AND FROM NELSON CO VA NORTH TO FAUQUIER CO...WHERE TEMPERATURES ARE CLOSER TO THE DEWPOINTS AT 05Z. ACROSS THE REMAINDER OF THE CWA WILL MENTION PATCHY FOG. STRONG EARLY AUGUST SUNSHINE SHOULD MIX OUT THE MORNING FOG BY 13Z EAST OF THE BLUE RIDGE AND BETWEEN 13Z AND 14Z TO THE WEST. 00Z RUNS OF THE GFS AND NAM BRING A SHORTWAVE RAPIDLY ACROSS NEW ENGLAND TODAY...AND THIS TROUGH IS PROGGED TO PICK UP THE WEAK TROUGH ACROSS THE EASTERN MID ATLANTIC AND DRAG IT TO THE EAST OVER THE ATLANTIC BY LATE THIS AFTERNOON. THIS WILL ALLOW WEAK RIDGING AT H85 AND H5 TODAY. NAM BUFKIT SOUNDINGS INDICATE THAT SCATTERED CU WILL FORM NEAR 4K FT LATE THIS MORNING AND THIS AFTERNOON. WITH H85 TEMPERATURES EXPECTED TO BE 1 TO 2 C WARMER THAN SUNDAY...EXPECT HIGHS TO BE IN THE MID 80S...SLIGHTLY BELOW NUMERICAL GUIDANCE. H85 AND SFC HIGH PRESSURE STRENGTHEN ACROSS THE OH VALLEY TONIGHT...AND SKIES ACROSS THE NORTHERN MID ATLANTIC WILL BECOME MOSTLY CLEAR. WITH LIGHT BOUNDARY LAYER FLOW TODAY THROUGH TONIGHT...BOUNDARY LAYER MOISTURE WILL REMAIN FAIRLY HIGH WITH SFC DEWPOINTS TONIGHT IN THE 60S TO NEAR 70. EXPECT PATCHY FOG TO FORM AGAIN LATE TONIGHT AND TUESDAY MORNING. LONG TERM...TUESDAY THROUGH SUNDAY... OVERALL HIGH PRESSURE WILL BE THE MAIN PLAYER FOR MUCH OF THIS NEW WEEK. HAVE ADDED ISOLATED TSRA IN THE HIGH TERRAIN ABOVE 2000 FT ON TUESDAY AND WEDNESDAY AFTERNOONS. SOME MUDDLED CONVERGENCE IS INDICATED ON THE NAM WHICH EVEN SPITS OUT SOME LIGHT QPF IN THE WEST. OTHERWISE THE PERIOD TUESDAY THROUGH FRIDAY IS EXPECTED TO BE MAINLY DRY AND WARM...TEMPS INTO THE LOWER 90S TUE-THU WILL BE TOLERABLE WITH DEWPOINTS RELATIVELY COMFORTABLE IN THE UPPER 60S TO NEAR 70. HEAT INDEX IS EXPECTED TO BE BELOW 100 DEG AT THIS TIME. ON FRIDAY THE COLD FRONT IS STILL EXPECTED TO APPROACH FROM THE NORTH...AND HAVE CONTINUED WITH CHANCE POPS IN THE WEST AND SLGT CHANCE IN THE EAST. ON SATURDAY THE GFS BRINGS A SFC WAVE THROUGH THE UPPER OHIO VALLEY WHICH MAY SPREAD RAIN INTO OUR REGION THROUGH SUNDAY...FOR NOW HAVE MAINTAINED CHANCE POPS SAT-SUN WITH WASHED OUT FRONT AND POSSIBILITY OF SFC WAVES. ALSO HAVE INDICATED HIGHER CLOUD AMOUNTS THROUGH THAT PERIOD AS WELL AS COOLER TEMPS. AVIATION... LIGHT FOG IS EXPECTED TO FORM AT IAD/DCA/BWI/MTN AGAIN THIS MORNING WITH VSBYS FALLING INTO THE MVFR TO NEAR IFR CATEGORY BETWEEN 09Z AND 12Z. AT MRB/CHO VSBYS IN FOG WILL BE IN THE IFR CATEGORY THROUGH 13Z. OTHERWISE WEAK HIGH PRESSURE AT THE SFC AND ALOFT WILL BRING VFR CONDITIONS TO ALL SITES AFTER 13Z. MVFR TO IFR VSBYS IN FOG ARE LIKELY AGAIN TUESDAY MORNING...AS SFC HIGH STRENGTHENS OVER THE OH VALLEY. MARINE... HIGH PRESSURE CENTERED IN THE WESTERN OH VALLEY WILL MOVE SLOWLY TO THE EAST TODAY. THIS SYSTEM WILL PRODUCE LIGHT EAST WINDS LESS THAN 5 TO 10 KTS TODAY. WINDS WILL DIMINISH TO 5 KT OR LESS TONIGHT...AS HIGH PRESSURE BUILDS IN FROM THE WEST. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ SHORT TERM/AVIATION/MARINE...PELOQUIN PREV DISCUSSION...SMITH/JB md AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI ISSUED BY NATIONAL WEATHER SERVICE GRAND RAPIDS MI 1130 AM EDT MON AUG 1 2005 .UPDATE... STRONG UPPER LEVEL RIDGE IN PLACE ACROSS THE NRN PLAINS TODAY. SURFACE BOUNDARY ACROSS THE NRN LAKES REGION WILL WASH OUT THROUGH THE DAY AS IT DROPS SLOWLY SOUTHEAST BENEATH UPPER LEVEL RIDGE. VERY WARM CONDITIONS WILL BUILD THROUGH LOWER MICHIGAN TODAY UNDER THE EASTERN EXTENT OF THE UPPER LEVEL RIDGE. MORNING SOUNDING AT DTX AND FORECAST 1000-850 MB THICKNESSES SUPPORT MAX TEMPERATURES IN THE UPPER 80S TO AROUND 90 ACROSS MUCH OF SE LOWER THIS AFTERNOON WITH THE EXTREME SE PORTION OF THE STATE PUSHING INTO THE LOWER 90S. PREVIOUS FORECAST HAD THIS WELL HANDLED AND MADE ONLY MINIMAL CHANGES TO AFTERNOON HIGH TEMPERATURES. TEMPERATURES IN THE UPPER 80S TO LOWER 90S AND DEWPOINTS IN THE UPPER 60S TO AROUND 70 WILL YIELD PLENTY OF INSTABILITY THIS AFTERNOON. SBCAPE VALUES ARE ALREADY IN THE 1500-2000 J/KG RANGE THIS MORNING AND EXPECT THAT SBCAPE VALUES WILL EXCEED 2000 J/KG ACROSS MOST SE LOWER THIS AFTERNOON. STILL 50-100 J/KG OF CONVECTIVE INHIBITION IN PLACE THIS MORNING BUT THIS WILL ERODE THIS AFTERNOON AS THE BOUNDARY LAYER CONTINUES TO WARM UP. HOWEVER...THE LACK OF ANY SUBSTANTIAL FORCING WILL LIMIT THE POTENTIAL FOR DEEP CONVECTION THIS AFTERNOON. AS THE INHIBITION ERODES ANY LAKE BREEZE THAT DEVELOPS MAY HAVE ENOUGH CONVERGENCE TO INITIATE CONVECTION AS THE LAKE BREEZE CIRCULATION WILL OPPOSE THE LOW LEVEL WESTERLY FLOW. ANY CONVECTION THAT IS ABLE TO DEVELOP WILL REMAIN ISOLATED IN COVERAGE AND THE MINIMAL DEEP LAYER SHEAR THAT IS IN PLACE WILL NOT SUPPORT WELL ORGANIZED STORMS. THE BEST CHANCE FOR THE DEVELOPMENT OF CONVECTION APPEARS TO BE IN THE THUMB AND WITH THIS IN MIND WILL KEEP THE SLIGHT CHANCE POPS GOING ACROSS THE NRN CWA. && .AVIATION... VIRTUALLY VFR TAF FORECASTS FOR ENTIRE 24 HOURS. EXCEPTION FOR VISIBILITY FOR KFNT SITE FOR 5 MILES IN MIST SHOULD BE MIXED OUT BY 13Z. CEILINGS ALL UNRESTRICTED EXCEPT FOR SOME BROKEN HIGH LEVEL MID CLOUDS NORTH SITES THIS MORNING. THICK CLOUDS MOVING DOWN FROM THE NORTHERN LAKES CONVECTION EARLIER HAVE CONTINUED TO THIN. && .SHORT TERM...TODAY AND TONIGHT...ISSUED 400 AM EDT MON MODELS IN FAIRLY GOOD CONSENSUS DEPICTING SURFACE COLD FRONT OVER NORTHERN LAKES REGION PRETTY MUCH WASHING OUT AS IT SLICES SOUTHEAST TODAY INTO TONIGHT...WHILE AT 500 MB HEIGHTS TENDING TO SLOWLY RISE THROUGH TONIGHT. VIGOROUS CONVECTION EARLIER ALONG NORTHERN FRONT HAS WEAKENED CONSIDERABLY WHILE SETTLING SOUTHWARD...AS ASSOCIATED CLOUDINESS/CONVECTIVE DEBRIS EXTENDS DOWN INTO NORTHERN PART OF FORECAST AREA. EXPECT THIS CLOUD COVER TO SHOW A STEADY THINNING TREND EARLY THIS MORNING...ALREADY UNDERWAY AS PER WARMING IR TOPS IN SATELLITE IMAGERY. WILL CONFINE CONVECTION MENTION TO SLIGHT CHANCE SAGINAW VALLEY AND THUMB THIS AFTERNOON...SUPPORTED BY RUC13 AND WRFXX...AS DAYTIME HEATING HAS A CHANCE TO WORK WITH WHAT IS LEFT OF COLD FRONT...WITH ESPECIALLY NAM DEPICTING QUITE UNSTABLE AFTERNOON CONDITIONS AND K INDICES TO AT LEAST 30...WITH FAIRLY STEEP 850 TO 700 MB LAPSE RATES. MOISTURE...LIMITED AS IT IS...WILL ALSO BE BEST IN THE NORTHERN COUNTIES OF SOUTHEAST MI. DYNAMICS WEAK THIS AFTERNOON AS WELL...IN TERMS OF OCCASIONAL WEAK LOW TO MID LEVEL OMEGA LIFT...SLIGHT 850 TO 500 MB QVECTOR CONVERGENCE AND SLIGHT SURFACE WIND CONVERGENCE. IN SOUTHERN ZONES...HIGH PRESSURE EXPECTED TO BE MORE IN CONTROL...AND ANY CHANCES OF CONVECTION TODAY TOO ISOLATED FOR FORECAST MENTION. AM GOING CLOSE TO GUIDANCE TEMPERATURES THROUGH TONIGHT...AS BOTH NAM AND NGM T1 TEMPERATURES ARE 3 TO 4 DEGREES CELSIUS WARMER THAN YESTERDAY...BRINGING MAXIMUM TEMPERATURES UP TO CLOSE TO 90 TODAY. && .LONG TERM...ISSUED 400 AM EDT MON DIFFERENCES ARISE BETWEEN THE NAM/GFS TUESDAY/WEDNESDAY...MAINLY WITH RESPECT TO CONVECTIVE DEVELOPMENT AND EVOLUTION UPSTREAM ACROSS THE WESTERN GREAT LAKES. HAVE NOT BEEN TOO IMPRESSED WITH THE WAY THE NAM HAS HANDLED CONVECTION RECENTLY. IN ADDITION...LOCAL WRF-XX OFFERS A SCENARIO SOMEWHAT SIMILAR TO THE GFS. AT THIS POINT WILL CONTINUE TO LEAN TOWARD THE GFS SOLUTION...WHICH IS DRIER THROUGH MID WEEK. ADDITIONAL DIFFERENCES BECOME APPARENT WITH THE APPROACHING COLD FRONT LATE IN THE WEEK /ALTHOUGH THE TIMING HAS BECOME INCREASINGLY NOT AS LATE IN THE WEEK GIVEN MODEL TRENDS OVER THE PAST FEW DAYS/. GFS HAS BEEN MORE CONSISTENT OVER THE LAST COUPLE RUNS...AND AGAIN HAS SUPPORT FROM OTHER EXTENDED MODELS. WEAK BOUNDARY LINGERS ACROSS THE CENTRAL GREAT LAKES...WITH HIGH PRESSURE OVER THE GREAT LAKES AND RIDGE EXTEND NORTHWARD ACROSS THE REGION. DECENT CAP APPARENT ON FORECAST SOUNDINGS...ESPECIALLY TOWARD THE SOUTHWEST CLOSER TO THE UPPER HIGH. MAIN AREA IN QUESTION FOR POPS IS ACROSS THE NORTHERN CWA/THUMB OUT INTO LAKE HURON...CLOSER TO THE WEAK TROUGH AND FARTHER AWAY FROM THE CWA. TEMPERATURES STILL LOOK GOOD IN THE UPPER 80S/LOW 90S. GRADIENT FLOW REMAINS OUT OF THE WEST ACROSS LOWER MICHIGAN...WHICH WITH A LARGE LAND/LAKE DELTA-T COULD LEAD TO MORE OF A TRUE UPRIGHT LAKE BREEZE CIRCULATION ACROSS THE THUMB...WHICH MAY ALSO AID CONVECTIVE POTENTIAL. DIFFERENCE BETWEEN TODAY AND TUESDAY IS WITH SYNOPTIC LIFT...AS WEAK 850-500MB QVECTOR CONVERGENCE WILL BECOME NEUTRAL BY TUESDAY AFTERNOON. AT THIS POINT WILL STICK WITH THE DRY FORECAST...ALTHOUGH A SLIGHT CHANCE MAY BE NECESSARY. NAM IS THE MOST AGRESSIVE SWINGING MCS REMNANTS ACROSS LOWER MICHIGAN TUESDAY NIGHT/WEDNESDAY. AS MENTIONED ABOVE...NAM HAS BEEN OVERDONE WITH THIS TYPE OF PATTERN RECENTLY. GFS INDICATES DEVELOPMENT FARTHER WEST...WHICH SEEMS MORE REASONABLE GIVEN THE PLACEMENT OF THE LOW-LEVEL JET. ACTIVITY SHOULD WEAKEN BEFORE REACHING SOUTHEAST MICHIGAN...AND WILL STICK WITH A DRY FORECAST FOR NOW. NAM IS MUCH WARMER THAN THE GFS/WRF-XX WITH 850MB TEMPS ON WEDNESDAY. FEEL THAT GFS MAY BE TOO COOL...DUE TO CONVECTIVE FEEDBACK FROM COMPLEXES UPSTREAM. WILL STICK WITH MORE OF A MIDDLE OF THE ROAD SOLUTION...KEEP TEMPERATURES SIMILAR TO THOSE ON TUESDAY...GENERALLY IN THE LOW 90S. AS MENTIONED ABOVE...GFS HAS BEEN MORE CONSISTENT THAN THE ETA WITH THE SPEED OF THE NEXT FRONT. ACTUALLY...WILL LEAN TOWARD THE SIMILAR WRF-XX AS IT HAS A TIGHTER SURFACE REFLECTION NOT AS CONTAMINATED BY GRIDSCALE CONVECTIVE DEVELOPMENT. CURRENT RUNS BRING THE THROUGH THURSDAY AFTERNOON/EVENING...WITH HIGH PRESSURE BUILDING IN BY FRIDAY. ADJUSTED TIMING ON THE FRONT SIDE A BIT...BRINGING IN A CHANCE TSRA ACROSS THE CWA THURSDAY AFTERNOON. GRIDS STILL LOOK GOOD ON THE BACK SIDE...STILL KEEPING A CHANCE INTO FRIDAY MORNING TO COVER TIMING UNCERTAINTIES. WILL STICK WITH A FLAT 30 PERCENT AT THIS POINT. OVERALL EVENT LOOKS WORTHY OF A HIGHER POP...BUT WILL STICK WITH 30 FOR NOW GIVEN THE BORDER PERIOD TIMING ISSUES AS WELL AS THE OVERALL SPEED/TIMING TRENDS WITH THE SYSTEM. ATMOSPHERE DRIES OUT AND TEMPERATURES COOL BACK TO NEAR/JUST BELOW NORMAL BY THE WEEKEND. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MI WATERS OF LAKE ERIE...NONE. && $$ AVIATION/UPDATE...DWD SHORT TERM...DWD LONG TERM....BRAVENDER UPDATE....RG mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1126 AM EDT MON AUG 1 2005 .UPDATE...MID MORNING SURFACE ANALYSIS SHOWS A SURFACE TROUGH LYING ACROSS THE TIP OF THE MITT COUNTIES...SANDWICHED BETWEEN HIGH PRESSURE CENTERS OVER NORTHEAST LAKE SUPERIOR AND WV. LOW CLOUDS AND SOME FOG CONTINUE TO PLAGUE MUCH OF CHIPPEWA COUNTY...WITH SOME OF THAT HAVING SPILLED SOUTH INTO FAR NORTHERN LAKE HURON. SOME FLAT SC DEVELOPED OVER NORTHWEST LOWER...WITH CAPPING INVERSION EVIDENT ON 12Z APX SOUNDING ALSO SHOWING UP IN SATELLITE WITH TRANSVERSE BANDING IN THIS CLOUD DECK. FARTHER EAST WHERE CAP IS WEAKER THUNDERSTORMS HAVE DEVELOPED OVER FAR EASTERN LAKE HURON AND GEORGIAN BAY. QUESTION FOR THIS AFTERNOON REVOLVES AROUND CONVECTIVE POTENTIAL. 12Z 850MB ANALYSIS SHOWING A NARROW AXIS OF HIGH DEW POINTS/THETA-E RUNNING ACROSS WESTERN/CENTRAL UPPER AND INTO NORTHERN LOWER...WITH DRIER AIR TO THE SOUTHWEST ADVECTING INTO SOUTHWEST LOWER. MODIFIED APX SOUNDING FOR 88/65 (WITH AT LEAST MID 60S DEW POINTS APPEARING QUITE REASONABLE FOR TODAY FOR MOST AREAS EXCEPT PERHAPS PARTS OF NORTHWEST LOWER...MORE ON THAT BELOW) YIELDS CAPES ABOVE 3000 J/KG WITH MINIMAL CINH. CAPPING MAY HOLD OVER NORTHWEST LOWER WITH MARINE FLOW OFF LAKE MICHIGAN...AND WHERE DRIER AIR ALOFT MAY MIX DEW POINTS DOWN A FEW DEGREES. BEST LARGE SCALE MOISTURE CONVERGENCE EXPECTED ACROSS UPPER MI AND NORTHEAST LOWER...WHERE LAKE BREEZE CONVERGENCE CAN ALSO FOCUS THINGS ON A SMALLER SCALE. SOME WEAK QG FORCING ALSO EXPECTED IN LOW LEVEL CONFLUENT FLOW. CURRENT FORECAST IS PRETTY REASONABLE...NOT A BIG FAN OF THE SLIGHT CHANCE USAGE SO WILL UP THE SLIGHT CHANCE AREAS TO CHANCE POPS...BUT TRIM BACK TO AREAS EAST OF US-131. DESPITE POTENTIALLY GOOD INSTABILITY...ORGANIZED SEVERE POTENTIAL WILL BE LIMITED BY WEAK WINDS ALOFT (AOB 25 KNOTS THROUGH 300MB)...SO ANY SEVERE STORMS WILL BE OF THE PULSE VARIETY HAIL/DOWNBURST EVENTS. JPB && .PREV DISCUSSION...ISSUED 500 AM EDT MON AUG 1. SFC MAP AT 03Z SHOWING WARM FRONT ACROSS NE LAKE HURON WITH A WEAK CIRCULATION IN EASTERN LAKE SUPERIOR AND ANOTHER IN FAR WESTERN LAKE SUPERIOR. IN BETWEEN THESE TWO SFC LOWS...A FRONTAL ZONE (ALBEIT WEAK) IS STRETCHED ACROSS UPPER MICHIGAN. STRONG TO SEVERE STORMS WERE FIRING ALONG THIS FRONTAL ZONE AND WERE MOVING SE AT ROUGHLY 30 MPH. SFC HIGH PRESSURE WAS NORTH OF THE OHIO RIVER VALLEY ASSOCIATED WITH THE DRIEST OF AIR. 00Z APX SOUNDING SHOWED THAT THUNDERSTORMS WERE NOT VERY FAR FROM POPPING WITH MINIMAL CAP LEFT. HOWEVER FROM 18Z-00Z...TEMPS AT 750MB ROSE FROM +8C TO +12C WHICH RESULTED IN THE CAP. THERE WAS 3000J/KG OF CAPE AVAILABLE WITH WET BULBS AROUND 11.8 KFT AND BULK SHEAR VALUES OF 35-40KTS. ANALYZING AREA ACARS SOUNDINGS...WE ONLY HAD 20J/KG OF CIN ACROSS EASTERN UPPER WITH 60J/KG ACROSS OUR EASTERN CWA SUGGESTING THAT STORMS COULD HAVE FIRED FURTHER SOUTH. HOWEVER...BOUNDARY THAT INITIATED THE STORMS HAS MADE IT ONLY TO MACKINAC COUNTY AND FAR NRN LAKE MICHIGAN. THE PRECIPITATION FROM EARLIER HAS OUTRUN THE BOUNDARY AND HEADED INTO A LESS FAVORABLE AIR MASS THAT COULD NOT SUSTAIN THEM. PLUS...THERE IS BASICALLY NO HELP AT H8...THEREFORE THE PRECIP HAS DIMINISHED. SYNOPTIC SETUP AND MODEL DISCUSSION...NAM WAS 2-3 DEGREES TOO COOL WITH THE TEMPERATURES AROUND THE CAP AT 00Z. GFS WAS MORE IN LINE. BOTH MODELS SHOW THE GENERAL TREND OF BRINGING SFC TROUGH AXIS OR WEAK COOL FRONT FROM THE WESTERN U.P. THROUGH THE STRAITS TO ROUGHLY ALPENA THIS MORNING...WHILE LATEST RUC SUGGESTS THAT THIS BOUNDARY WILL MOVE VERY LITTLE...AND HANG ACROSS EASTERN UPPER. FORECAST CONCERNS DEAL WITH PRECIP CHANCES THROUGH TUESDAY AND HOW WARM WE WILL GET...SAME AS LAST FEW DAYS. TODAY AND TONIGHT...MAIN QUESTION IS...HOW FAR SOUTH WILL THE FRONTAL ZONE GO AND HOW MUCH CONVERGENCE WILL IT HAVE? WITH BOUNDARY HANGING FURTHER TO THE NORTH...WILL BLEND WITH THE RUC AND GFS IDEA OF KEEPING IT ACROSS THE STRAITS REGION TODAY...BUT CONVERGENCE BECOMES RATHER MEAGER WITH IT WASHING OUT WHILE SFC HIGH PRESSURE MOVES IN FROM THE WEST. STILL HAVE AN AXIS OF HIGHER THETA-E AIR ALONG THIS BOUNDARY WITH A DEGREE OR TWO OF COOLING NOTED IN THE 700-750MB LAYER (WHERE CAP WAS AT 00Z YESTERDAY). H8 WINDS WILL BE LESS TODAY (10-15KTS)...SUPPORTING LAKE BREEZES MOST ALL NEARSHORE AREAS. OVERALL SW GRADIENT FLOW SUPPORTS BEST CONVERGENCE THIS AFTERNOON ACROSS THE SE CWA. MODIFYING SOUNDINGS REVEAL 1000J/KG ACROSS EASTERN UPPER TODAY WITH AS MUCH AS 2200J/KG IN THE SE CWA WITH CONVECTIVE TEMPS IN THE 85-89F RANGE. DO BELIEVE WE'LL SEE SCATTERED CONVECTION DEVELOP MAINLY EAST OF I-75 IN NRN LOWER...AND MACKINAC COUNTY IN EASTERN UPPER. SLIGHT CHANCE EXISTS FOR INLAND CHIPPEWA COUNTY WHERE LAKE BREEZE BOUNDARY MAY BE VIGOROUS ENOUGH TO FIRE OFF ACTIVITY. BULK SHEAR RATHER MINIMAL AT 20-25KTS SO STORM ORGANIZATION NOT AS LIKELY AS LAST NIGHT. COULD NOT RULE OUT ONE OR TWO STORMS GETTING A STRONG ENOUGH UPDRAFT FOR LARGE HAIL/DAMAGING WINDS...BUT OVERALL SEVERE THREAT IS MINIMAL. ANY AFTERNOON CONVECTION WILL DISSIPATE RATHER QUICKLY EARLY THIS EVENING...AND WITH ANTICYCLONIC H8 FLOW AND NO OTHER DYNAMICAL HELP ALOFT FORESEEN...WILL CONTINUE WITH A PRECIP FREE FORECAST. AXIS OF THETA-E AIR REMAINS/LIFTS SLOWLY BACK TO THE NORTH AND WILL BE THE AREA TO WATCH IF ANYTHING DOES DECIDE TO DEVELOP. HIGHS TODAY WITH SIMILAR H8 TEMPS AND GOOD SOLAR HEATING WILL MAKE IT INTO THE MID AND UPPER 80S...AND WITH TD'S IN THE MIDDLE 60S...LOWS OVERNIGHT WILL RANGE IN THE LOWER TO MIDDLE 60S. TUESDAY AND TUESDAY NIGHT...WILL STAY RATHER WARM...H8 TEMPS RISE TO 19C OR SO...AND SFC TEMPS WILL MAKE IT INTO THE UPPER 80S AND LOWER 90S. DO NOT KNOW HOW MUCH STOCK CAN BE PLACED INTO GFS COOLING SEEN AROUND H7 IN A PATTERN WHERE H5 HEIGHTS ARE RISING. NEVERTHELESS... STEEPER LAPSE RATES BETWEEN H8-H7 SEEN...AND MODIFIED SOUNDINGS SHOWING THAT CONVECTIVE TEMPS WILL BE REACHED/CAP ERODED. THIS USING A PARCEL OF 88/65 AND GETTING CAPES TO 1800 TO 2000J/KG...MAINLY FOR AREAS SOUTH OF A HTL-APN LINE. HAVE INTRODUCED A 20% POP FOR THIS AREA BUT WILL ALSO HAVE TO MONITOR AREAS AWAY FROM MARINE INFLUENCE DOWNWIND OF LAKES (IN SW FLOW)...SUCH AS CHIPPEWA COUNTY WHERE CIN IS ONLY 20-30J/KG. LAKE BREEZES THIS DAY AS WELL AND COULD BE A FOCUS FOR THUNDERSTORM DEVELOPMENT. HAVE HELD OFF ON INTRODUCING POPS THERE ATTM. AGAIN...ANY ACTIVITY WILL QUICKLY DISSIPATE IN THE EARLY EVENING...RESULTING IN PARTLY CLOUDY TO MOSTLY CLEAR SKIES. MIN TEMPS LOOK TO FALL INTO THE MIDDLE AND UPPER 60S. NO OTHER CHANGES...WARM TEMPS UNTIL THURSDAY AFTERNOON/EVENING WHEN COLD FRONT SWEEPS THROUGH NRN MICHIGAN. SMD && .APX...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1117 AM EDT MON AUG 1 2005 .DISCUSSION... THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS THE FOG IN THE EAST AND THE CHANCE OF THUNDERSTORMS IN THE WEST THIS AFTERNOON. WATER VAPOR IMAGERY AND RUC/ETA SHOWING A LARGE RIDGE OVER THE SOUTH CENTRAL CANADA. WEAK SHORTWAVE ARE MOVING DOWN THE LEE OF THE RIDGE AND MOVING THROUGH NORTHERN MINNESOTA. SURFACE ANALYSIS INDICATE A RIDGE OVER THE FORECAST AREA. A WEAK FRONTAL SYSTEM STRETCHES FROM CENTRAL WISCONSIN THROUGH NORTHERN LOWER MICHIGAN. A WEAK SHORTWAVE MOVING DOWN THE LEE OF THE RIDGE WILL MOVE OVER WESTERN LAKE SUPERIOR THIS AFTERNOON. THE WEAK SURFACE RIDGE WILL SIT OVER THE UPPER GREAT LAKES WHILE THE SURFACE FRONT IS EXPECTED TO REMAIN NEARLY STATIONARY OVER LOWER MICHIGAN. MUCAPE VALUES WILL REACH AROUND 4000J/KG OVER WESTERN U.P. WHILE OVER THE LAKE MUCAPE WILL REACH ONLY 400J/KG. A THETA-E RIDGE WILL HANG AROUND THE WESTERN U.P. WARM AIR ADVECTION AROUND 600MB AND COLD AIR ADVECTION BELOW 700MB WILL DEVELOP CAP WHICH WILL LIMIT THUNDERSTORM DEVELOP THIS AFTERNOON. THE AIR MASS IS VERY DRY. ETA12 SOUNDING FORECAST INDICATE A MOIST LAYER AROUND 850MB OVER THE CENTRAL U.P. THUS LOOKING FOR A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS MAINLY OVER THE SOUTH CENTRAL U.P. && .MQT...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DLG mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 725 AM EDT MON AUG 1 2005 .UPDATE... WILL SHORTLY UPDATE TO REMOVE PATCHY FOG WORDING FROM EARLY MORNING FORECAST. SUNRISE AND WINDS/MIXING FROM THIS JUNCTURE SHOULD THWART FOG. && .AVIATION... VIRTUALLY VFR TAF FORECASTS FOR ENTIRE 24 HOURS. EXCEPTION FOR VISIBILITY FOR KFNT SITE FOR 5 MILES IN MIST SHOULD BE MIXED OUT BY 13Z. CEILINGS ALL UNRESTRICTED EXCEPT FOR SOME BROKEN HIGH LEVEL MID CLOUDS NORTH SITES THIS MORNING. THICK CLOUDS MOVING DOWN FROM THE NORTHERN LAKES CONVECTION EARLIER HAVE CONTINUED TO THIN. && .SHORT TERM...TODAY AND TONIGHT...ISSUED 400 AM EDT MON MODELS IN FAIRLY GOOD CONSENSUS DEPICTING SURFACE COLD FRONT OVER NORTHERN LAKES REGION PRETTY MUCH WASHING OUT AS IT SLICES SOUTHEAST TODAY INTO TONIGHT...WHILE AT 500 MB HEIGHTS TENDING TO SLOWLY RISE THROUGH TONIGHT. VIGOROUS CONVECTION EARLIER ALONG NORTHERN FRONT HAS WEAKENED CONSIDERABLY WHILE SETTLING SOUTHWARD...AS ASSOCIATED CLOUDINESS/CONVECTIVE DEBRIS EXTENDS DOWN INTO NORTHERN PART OF FORECAST AREA. EXPECT THIS CLOUD COVER TO SHOW A STEADY THINNING TREND EARLY THIS MORNING...ALREADY UNDERWAY AS PER WARMING IR TOPS IN SATELLITE IMAGERY. WILL CONFINE CONVECTION MENTION TO SLIGHT CHANCE SAGINAW VALLEY AND THUMB THIS AFTERNOON...SUPPORTED BY RUC13 AND WRFXX...AS DAYTIME HEATING HAS A CHANCE TO WORK WITH WHAT IS LEFT OF COLD FRONT...WITH ESPECIALLY NAM DEPICTING QUITE UNSTABLE AFTERNOON CONDITIONS AND K INDICES TO AT LEAST 30...WITH FAIRLY STEEP 850 TO 700 MB LAPSE RATES. MOISTURE...LIMITED AS IT IS...WILL ALSO BE BEST IN THE NORTHERN COUNTIES OF SOUTHEAST MI. DYNAMICS WEAK THIS AFTERNOON AS WELL...IN TERMS OF OCCASIONAL WEAK LOW TO MID LEVEL OMEGA LIFT...SLIGHT 850 TO 500 MB QVECTOR CONVERGENCE AND SLIGHT SURFACE WIND CONVERGENCE. IN SOUTHERN ZONES...HIGH PRESSURE EXPECTED TO BE MORE IN CONTROL...AND ANY CHANCES OF CONVECTION TODAY TOO ISOLATED FOR FORECAST MENTION. AM GOING CLOSE TO GUIDANCE TEMPERATURES THROUGH TONIGHT...AS BOTH NAM AND NGM T1 TEMPERATURES ARE 3 TO 4 DEGREES CELSIUS WARMER THAN YESTERDAY...BRINGING MAXIMUM TEMPERATURES UP TO CLOSE TO 90 TODAY. && .LONG TERM...ISSUED 400 AM EDT MON DIFFERENCES ARISE BETWEEN THE NAM/GFS TUESDAY/WEDNESDAY...MAINLY WITH RESPECT TO CONVECTIVE DEVELOPMENT AND EVOLUTION UPSTREAM ACROSS THE WESTERN GREAT LAKES. HAVE NOT BEEN TOO IMPRESSED WITH THE WAY THE NAM HAS HANDLED CONVECTION RECENTLY. IN ADDITION...LOCAL WRF-XX OFFERS A SCENARIO SOMEWHAT SIMILAR TO THE GFS. AT THIS POINT WILL CONTINUE TO LEAN TOWARD THE GFS SOLUTION...WHICH IS DRIER THROUGH MID WEEK. ADDITIONAL DIFFERENCES BECOME APPARENT WITH THE APPROACHING COLD FRONT LATE IN THE WEEK /ALTHOUGH THE TIMING HAS BECOME INCREASINGLY NOT AS LATE IN THE WEEK GIVEN MODEL TRENDS OVER THE PAST FEW DAYS/. GFS HAS BEEN MORE CONSISTENT OVER THE LAST COUPLE RUNS...AND AGAIN HAS SUPPORT FROM OTHER EXTENDED MODELS. WEAK BOUNDARY LINGERS ACROSS THE CENTRAL GREAT LAKES...WITH HIGH PRESSURE OVER THE GREAT LAKES AND RIDGE EXTEND NORTHWARD ACROSS THE REGION. DECENT CAP APPARENT ON FORECAST SOUNDINGS...ESPECIALLY TOWARD THE SOUTHWEST CLOSER TO THE UPPER HIGH. MAIN AREA IN QUESTION FOR POPS IS ACROSS THE NORTHERN CWA/THUMB OUT INTO LAKE HURON...CLOSER TO THE WEAK TROUGH AND FARTHER AWAY FROM THE CWA. TEMPERATURES STILL LOOK GOOD IN THE UPPER 80S/LOW 90S. GRADIENT FLOW REMAINS OUT OF THE WEST ACROSS LOWER MICHIGAN...WHICH WITH A LARGE LAND/LAKE DELTA-T COULD LEAD TO MORE OF A TRUE UPRIGHT LAKE BREEZE CIRCULATION ACROSS THE THUMB...WHICH MAY ALSO AID CONVECTIVE POTENTIAL. DIFFERENCE BETWEEN TODAY AND TUESDAY IS WITH SYNOPTIC LIFT...AS WEAK 850-500MB QVECTOR CONVERGENCE WILL BECOME NEUTRAL BY TUESDAY AFTERNOON. AT THIS POINT WILL STICK WITH THE DRY FORECAST...ALTHOUGH A SLIGHT CHANCE MAY BE NECESSARY. NAM IS THE MOST AGRESSIVE SWINGING MCS REMNANTS ACROSS LOWER MICHIGAN TUESDAY NIGHT/WEDNESDAY. AS MENTIONED ABOVE...NAM HAS BEEN OVERDONE WITH THIS TYPE OF PATTERN RECENTLY. GFS INDICATES DEVELOPMENT FARTHER WEST...WHICH SEEMS MORE REASONABLE GIVEN THE PLACEMENT OF THE LOW-LEVEL JET. ACTIVITY SHOULD WEAKEN BEFORE REACHING SOUTHEAST MICHIGAN...AND WILL STICK WITH A DRY FORECAST FOR NOW. NAM IS MUCH WARMER THAN THE GFS/WRF-XX WITH 850MB TEMPS ON WEDNESDAY. FEEL THAT GFS MAY BE TOO COOL...DUE TO CONVECTIVE FEEDBACK FROM COMPLEXES UPSTREAM. WILL STICK WITH MORE OF A MIDDLE OF THE ROAD SOLUTION...KEEP TEMPERATURES SIMILAR TO THOSE ON TUESDAY...GENERALLY IN THE LOW 90S. AS MENTIONED ABOVE...GFS HAS BEEN MORE CONSISTENT THAN THE ETA WITH THE SPEED OF THE NEXT FRONT. ACTUALLY...WILL LEAN TOWARD THE SIMILAR WRF-XX AS IT HAS A TIGHTER SURFACE REFLECTION NOT AS CONTAMINATED BY GRIDSCALE CONVECTIVE DEVELOPMENT. CURRENT RUNS BRING THE THROUGH THURSDAY AFTERNOON/EVENING...WITH HIGH PRESSURE BUILDING IN BY FRIDAY. ADJUSTED TIMING ON THE FRONT SIDE A BIT...BRINGING IN A CHANCE TSRA ACROSS THE CWA THURSDAY AFTERNOON. GRIDS STILL LOOK GOOD ON THE BACK SIDE...STILL KEEPING A CHANCE INTO FRIDAY MORNING TO COVER TIMING UNCERTAINTIES. WILL STICK WITH A FLAT 30 PERCENT AT THIS POINT. OVERALL EVENT LOOKS WORTHY OF A HIGHER POP...BUT WILL STICK WITH 30 FOR NOW GIVEN THE BORDER PERIOD TIMING ISSUES AS WELL AS THE OVERALL SPEED/TIMING TRENDS WITH THE SYSTEM. ATMOSPHERE DRIES OUT AND TEMPERATURES COOL BACK TO NEAR/JUST BELOW NORMAL BY THE WEEKEND. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MI WATERS OF LAKE ERIE...NONE. && $$ AVIATION/UPDATE...DWD SHORT TERM...DWD LONG TERM....BRAVENDER mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON MS 1117 AM CDT MON AUG 1 2005 .DISCUSSION... WILL DO A QUICK UPDATE TO REMOVE ANY MORNING WORDING. MADE SOME ADJUSTMENTS TO THE GRIDS THROUGH 18Z...CLOUDS AND FOG HAVE LIFTED AND CU HAVE NOT FILLED IN JUST YET...SO NORTHWEST HALF WAS MOSTLY CLEAR. A FEW SHOWERS WERE DEVELOPING OVER THE SOUTHEAST. FLOW WAS FROM THE SOUTHEAST...BUT VAD PROFILE AND RUC ANALYSIS BOTH SHOW WEAK NORTHEAST FLOW...SUSPECT STORMS WILL DEVELOP SIMILAR TO YESTERDAY. PW VALUES REMAIN NEAR 2 INCHES...SO PERIODS OF HEAVY RAIN CAN BE EXPECTED...WILL CONSIDER ADDING HEAVY RAIN AND PONDING TO THE HWO FOR THE AFTERNOON/EVENING. ALL OTHER ADJUSTMENTS WERE COSMETIC OR RELATED TO THE GRIDS...UPDATE JUST TO REMOVE MORNING WORDING. && .AVIATION... WILL CONTINUE WITH CURRENT FORECAST. AFTERNOON SHOWERS AND THUNDERSTORMS WITH PATCHY FOG OVERNIGHT. PERIODS OF HEAVY RAIN...SO WILL CONTINUE WITH REDUCED VISIBILITIES...2-3 MILES...FOR THE AFTERNOONS. WITH RAIN EXPECTED TO REACH JAN...MEI...HBG WILL CONTINUE STRATUS FOR THE EARLY MORNING. MODELS SHOW RAIN LINGERING TO THE EAST THROUGH TONIGHT...SO MAY LEAVE VCSH IN FOR HBG/MEI. OTHERWISE...MORE OF THE SAME FOR ANOTHER DAY. && .PRELIMINARY POINT TEMPS/POPS... JACKSON 89 71 89 73 / 60 20 60 20 MERIDIAN 89 70 88 70 / 60 30 80 30 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ 07/99/99 ms AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE BINGHAMTON NY 955 AM EDT MON AUG 1 2005 .SHORT TERM (THIS AFTERNOON)... VIS SATL IMAGERY SHOWS THAT PLENTY OF SUNSHINE WILL BREAK OUT ACRS C NY/NE PA AS THE AFTERNOON BEGINS. CLOUDS WERE ERODING AND WILL CONT TO DO SO. CURRENT SFC DWPTS AND LL MOISTURE PROFILES SUPPORT DEWPOINTS INTO THE MID 60S BY MID AFTRN. WITH INSOLATION SEE MAX TEMPS UP TO THE MID TO UPPER 80S MOST PLACES. USING THE 12Z BUF SOUNDINGS WHICH HAS PREDOMINATELY WRLY FLO...MODIFIED IT WITH T=86F TD=65F AND USED A MEAN LAYER OF THE LOWEST 100 MB AND CAME UP WITH ABT 1750 J/KG CAPE. LOCALLY WHERE TEMPS ARE HIGHER CUD SEE CAPES CLOSE TO 2000 J/KG. WV IMAGERY INDICATES A SHORT WAVE IS DROPPING SE TWD ERN NY STATE. THIS WAVE INCREASES THE FLO ALOFT WHICH IN TURN INCREASES THE VERTICAL WIND SHEAR. MODELS INDICATES 0-6KM BULK SHEAR OF 30-40 KTS ACRS THE NRN/ERN PART OF CWA LATE TODAY. 0-3KM BULK SHEAR IS MORE MARGINAL BETWEEN 15 AND 20 KTS IN THE SAME AREAS. IN ADDTN...SOUNDINGS SHOW DRIER AIR POISE TO MOV IN AT MID-LVL/S AS THIS SHRT WAVE TRACKS S AND E. GIVEN THE PROJECTED CAPES...INCREASING VERTICAL WIND SHEAR COINCIDING WITH MAX HEATING AND DRY ADVECTION ALOFT AT THE SAME TIME...POTENTIAL EXISTS FOR A FEW SEVERE STORMS. I CAN SEE A SCENARIO WHERE THE CELLS BEGIN TO FIRE IN THE NRN PART OF BGM CWA AND EVENTUALLY BECOME MORE ORGANIZES TWD EVE AS THEY WORK S AND E...PROBABLY E OF OUR AREA. CONCUR WITH SPC ON SLGHT RISK FOR OUR REGION AND WILL ISSUE AN OUTLOOK STATEMENT. WILL ALSO UPDATE HWO TO REFLECT THIS CHANGE. WILL WAIT FOR 10 AM OBS AND ADJUST MAXES IF NEEDED. ZONES AND GRIDS WILL BE OUT BEFORE 1030 AM. - NICOSIA PREVIOUS SHORT TERM (THRU TUE) COMPLEX YET SUBTLE PTRN DETERMINING THE DVLPMT AND CONTINUATION OF CONV ELEMENTS. THIS MRNG...MESOSCALE TROF...RDG...TROF SFC SETUP. MCC OVER NRN MI AND SE ONTARIO HAS BEEN DROPPING INTO THE STUBBORN MESO RDG OVER WRN NY AND ERODING. BOTH THE LATEST RUC AND NAM RUNS SHOW THIS FEATURE HOLDING FAST AND KEEPING THIS CONV WELL NORTH OF THE FCST AREA. HWVR...BOTH CONT TO SHOW CONV ALONG THE WEAK SFC TROF/BNDRY OVER CNTRL AND ERN NY AND NRN PA. STILL THE PSBLTY THAT SOMETHING COULD DVLP...BUT BNDRY/S BEEN QUIET THRU THE NGT. BNDRIES ARE SO WEAK...THERE DFCLT TO TRACK BUT IT SEEMS AS THOUGH YET ANOTHER...OR THE SAME...OLD BNDRY SETTLES SWRD LTR THIS AFTN AND FEED ON THE GNRL INSTABILITY TO DVLP MORE TRWS. XPCT CONV TO DVLP OVER CNTRL NY THIS AFTN AND SETTLE INTO NRN PA THIS EVE. SOME BORDERLINE SVR WX SUN AFTN...AND SOME PSBL AGAIN TODAY. WIND FIELDS ARE SLGTLY MORE IMPRESSIVE...ESP OVER NY...SO SOME ISLTD WIND DAMAGE RPTS PSBL. ACTIVITY SHD TAPER OFF QUICKLY THIS EVE AND OVRNGT HRS SHD BE DRY AS THE AIRMASS STABILIZES. GNRLY STABLE ON TUE HGTS BLD. NAM SHOWS A WEAK SHRT WV DROPPING THRU THE RDG AND WEAKENS THE CAPPING OVER PA AND XTRM WRN NY. SEEMS LIKE ANY PSBLTY OF TRWS OVER THE FCST AREA IS LIMITED...BUT WILL NOT ADJUST CRNT FCST OF LOW CHANCE POPS OVER THE XTRM SW. THAT AREA WLD HAVE THE BEST CHANCE. MINOR TWEAKS OF TEMPS AND POPS TO FIT LATEST MODEL AND MOS CONSENSUS...OTRW NO MAJOR CHGS TO THE FCST THIS UPDATE. -MORFORD && .LONG TERM (TUESDAY NIGHT - MONDAY)... ON WRN EDGE OF UL TROF IN NW ATLANTIC SO NW FLOW ALOFT AND NEAR NORMAL TEMPERATURES THROUGH THE FIRST HALF OF EXTENDED. WEAK FORCING COULD SET OFF SOME SHOWERS BUT LEFT OUT AS SURFACE HIGH BUILDS IN WEDNESDAY THEN THU PULLS OFF THE EAST COAST AND RIDGING ALOFT. WITH SW FLOW THU INTO FRI HUMIDITY AND A TAD MORE HEAT WILL RETURN AHEAD OF SECOND COLD FRONT FRI NIGHT. THIS FRONT HAS MORE PUSH WITH A WEAK UL TROF...JET AND SHORT WAVE. QUESTION IS ABOUT TIMING WITH A FEW MODELS INCLUDING DGEX A FEW HOURS FASTER. THIS WOULD MEAN MORE CLOUDS AND LESS HEATING. AS HAS BEEN THE CASE LATELY FRONT EXPECTED TO MAKE GOOD PROGRESS OUT OF ONTARIO AND THROUGH NY THEN STALLS IN PA. LINGERING CHANCES OF PRECIP INTO SAT NGT BEFORE CANADIAN HIGH PRESSURE BUILDS IN SUNDAY. FOLLOWED HPC GUIDANCE CLOSELY. -TAC && .AVIATION (01/06Z - 02/06Z) SOME LGT FOG THIS MRNG RESULTING IN MVFR CONDS SOME STATIONS. ANY IFR CONDS SHD BE BRIEF. VFR CONDS SHD RULE THE REMAINDER OF THE FCST PD. SCT CONV WILL LIKELY DVLP THIS AFTN WITH GUSTY WINDS AND BRIEFLY LWR CONDS. && .BGM WATCHES/WARNINGS/ADVISORIES... .NY...NONE. .PA...NONE. && $$ ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 1020 AM EDT MON AUG 1 2005 .SHORT TERM /TODAY/...SFC FNTL BNDRY NOW LINGERING OFFSHORE ALONG WITH NRN END OF SFC MOISTURE CONVERGENCE AXIS. AXIS IS LYING APPROXIMATELY ALONG A KVDI-KSAV-KHXD-41004 LINE AS EVIDENT BY STREAMLINE ANALYSIS AND KCLX 88D RADAR TRENDS. WITH SOLID NELY FLOW N OF THIS LINE...ALONG WITH LEFTOVER CONVECTIVE RAINS FROM YDA AND OVR...WIDESPREAD LLVL CLOUD COVER IS ACROSS MUCH OF THE AREA. MEANWHILE...S OF THIS AXIS IS SEEING MORE CU ALONG WITH MORE BREAKS IN THE CLOUDS WHICH WILL ALLOW FOR SFC HEATING TO TAKE ADVANTAGE OF THE 2.3 INCH PWAT...3200 CAPE AND LOW LFC THIS AFTN. MAIN CONCERN IS COVERAGE OF PRECIP. RUC/M-ETA HINT THAT THE BNDRY MAY RETREAT NWD THRU THE DAY WHICH WOULD ALLOW FOR MORE OF THE AREA TO EXPERIENCE HEATING AND INSTABILITY. EVEN SO...IT WOULD TAKE A LOT OF LIFT TO BREAK THE THICK CLOUD COVER OVER THE SC PORTION OF THE CWFA. HAVE OPTED TO SCALE BACK POPS TO 50 FOR FAR NRN INLAND PORTIONS OF THE CWFA FOLLOWED BY 60S IN CENTRAL AND COASTAL SC PORTIONS FOLLOWED BY 70S FOR SRN SE GA. AS FAR AS CONVECTIVE HAZARDS TDA...MOST PROMINENT IS HVY RAINFALL. WINDS THRU H5 ARE VIRTUALLY NIL MAKING STORM MOTIONS RATHER WEAK. MUCH OF THE CENTRAL AND SRN PORTIONS OF THE CWFA HAS RECEIVED 2-5 INCHES OF RAIN THE PAST COUPLE OF DAYS...AND ANY SLOW MOVING STRONG STORM CAN EASILY EXACERBATE FLOODING CONCERNS. DOWNBURSTS ARE NOT AS MUCH OF A THREAT WITH LESSENING VERTICAL MOTIONS...BUT BOUNDARY COLLISIONS CAN MAKE FOR GUSTY WINDS. SEABREEZE MAY NOT MAKE AS MUCH LAND PENETRATION DUE TO CLOUDS HOLD BACK OPTIMUM LAND HEATING. SPEAKING OF WHICH...DUE TO THE CLOUD COVER AND PLENTY OF MOISTURE TEMPS ARE BELOW THE CURVE TWD FCST MAX TEMPS. HAVE LOWERED MAX TEMPS BY 1-2 DEGREES WHICH DROPS SOME LOCATIONS INTO A LOWER CATEGORY. WILL ISSUE UPDATED GRIDDED AND TEXT PRODUCTS FOR ALL THESE CHANGES. && .MARINE...CONTINUED LGT WINDS AND TRANQUIL SEAS. WIND DIRECTIONS MAY BE A BIT TRICKY DUE TO WOBBLING OF SFC BNDRIES BUT XPCT OVERALL TREND OF NE WINDS TO PERSIST. WILL MAKE MINOR INITIALIZATION TWEAKS BUT OVERALL THINKING IS GOOD. && .AVIATION...LOW CIGS AT BOTH TERMS MAKING FOR A ROUGH START TDA. LOW CIGS LOOK TO STEADILY THIN OUT TO SCT WHILE UPR LVL MOISTURE HOLDS HIGH LVL BKN/OVC SKIES. KSAV MAY SEE A BIT MORE BREAKS IN THE CLOUDS THAN KCHS. MAIN CONCERN IS AGAIN TIMING OF PRECIP. HARD TO ARGUE WITH WHAT 01/12Z TAFS HAVE GOING FOR TIMING AS PRECIP WILL BE DIFFICULT TO PINPOINT IN THE AFTN HRS...SO WILL MONITOR AND AMD IF/AS NEEDED. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ JPC sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 214 PM EDT MON AUG 1 2005 .SHORT TERM (TONIGHT THROUGH TUESDAY NIGHT)... A TYPICAL MID SUMMER DAY IN PROGRESS WITH TEMPS EVERYWHERE IN THE 80S AND DEWPOINTS RUNNING IN THE NOTICEABLE TO MUGGY RANGE. STILL LITTLE IN THE WAY OF CONVECTION CAUSING ANY PROBLEMS. INCREASINGLY WARM MID LEVELS...AND LACK OF LOW LEVEL FORCING...ARE COMBINING TO KEEP A LID ON THINGS SO FAR TODAY. CLOUDS ARE SLIGHTLY MORE ENHANCED NORTH OF THE BORDER. THE RUC AND ETA12 BOTH SEEM TO WANT TO GENERATE SOME CONVECTION...POSSIBLY CENTERED AROUND THE LAKE BREEZES...AND THEN MIGRATE IT SOUTHEASTWARD LATER IN THE DAY AND EARLY EVENING. HAVE PUT MY HIGHEST CHC POPS...STILL JUST SLIGHT...OVER MY NORTHERN TIER DOWN INTO THE EASTERN SECTIONS OF THE MIDDLE SUSQ VALLEY. A STRAY SHOWER OR STORM CANNOT BE RULED OUT. WEAK FORCING AND LAZY SUMMERY CONDITIONS WILL LAST THRU TUESDAY. GUID SUGGESTS 850 TEMPS A DEG OR 2 WARMER THAN TODAY...SO IT SHUD FOLLOW THAT SFC TEMPS WILL ALSO BE A TAD WARMER. KEEPING THE SAME LOW TO ALMOST NON-EXISTENT POPS FOR TUESDAY AND TUE NIGHT. && .LONG TERM (WEDNESDAY THROUGH MONDAY)... TEMPS ALOFT TODAY SIMILAR TO SUNDAY. ESTIMATED VIL OF THE DAY IS SIMILAR TO YESTERDAY...IN THE MID 50S. SO FAR NOTHING GOING ON TODAY...WIND SHIFT LINE HAS MOVED PAST THE AREA...AND SLIGHTLY DRIER AIR HAS MOVED IN. OVERALL...THIS WILL BE THE TREND THE NEXT FEW DAYS. MODELS DID HINT THE LAST FEW DAYS THAT NE PA MIGHT GET SOMETHING LATER TODAY AND OR ON TUE. SOME STRONGER CELLS OVER ONTARIO...COULD TRY TO MAKE A RUN TOWARD THE EDGE OF OUR CWA...BUT THAT IS ABOUT ALL I SEE GOING ON THROUGH THURSDAY. SOME HINTS OF A MCS LATE WED INTO THU ACROSS NW PA...BUT OTHERWISE DRY. DID GO WITH A CHC FOR FAR NW COUNTIES THURSDAY NIGHT. FRONT STILL DROPS SE ACROSS THE REGION LATE FRIDAY INTO SAT. STILL SOME HINTS THAT FRONT WILL SLOW DOWN. HOWEVER...AFTER SATURDAY NIGHT...WENT WITH DRY CONDITIONS FOR SUNDAY INTO MONDAY. GFS HARD TO FOLLOW WITH WHERE THINGS COME AND GO...COULD BE CONVECTIVE FEEDBACK PROBLEMS. TEMPS NORMAL TO SLIGHTLY ABOVE NORMAL. LATER SHIFTS CAN ADD SHOWERS TO SUNDAY AND MONDAY IF NEEDED. && .AVIATION... SOME EARLY MORNING LOW CLOUDS AND HAZE ISSUES HAVE DISSIPATED TO A NICE AFTERNOON WITH JUST SOME LINGERING MVFR HAZE CONCERNS OVER THE LOWER SUSQ. WILL LIKELY SEE VIS LOWERING ONCE AGAIN OVERNIGHT IN THE HUMID AIRMASS WITH A SVRL HOUR PERIOD NEEDED EARLY TUESDAY TO BURN OFF THE MVFR/IFR CONDITIONS. THE GOOD NEWS IS THAT THE THREAT FOR CONVECTION WILL REMAIN LIMITED THE NEXT 24-36 HOURS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...LACORTE LONG TERM...MARTIN AVIATION...LACORTE pa