Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/05/14


AREA FORECAST DISCUSSION...UPDATED
NWS PHOENIX AZ
1215 PM MST SUN AUG 3 2014. && .SYNOPSIS... AFTER ONE MORE DAY OF WIDESPREAD THUNDERSTORM ACTIVITY TODAY...AS A UPPER LEVEL LOW CENTER MOVING INLAND INTO SOUTHERN CA AFFECTS OUR REGION...A SIGNIFICANT DRYING TREND IS THEN EXPECTED TO BEGIN ON MONDAY...UNDER SOUTHWESTERLY FLOW ALOFT...LIMITING STORM CHANCES TO EASTERN ARIZONA THROUGH MIDWEEK. A GRADUAL RETURN OF STORM CHANCES FROM EAST TO WEST IS THEN EXPECTED TO BEGIN BY THE END OF THE WEEK...PERHAPS CONTINUING INTO THE UPCOMING WEEKEND. && .DISCUSSION... TODAY AND TONIGHT... AFTER A QUIET START THIS MORNING...AS DRIER AIR ALOFT SPREAD IN FROM THE SOUTH ACROSS THE REGION...ONE MORE BUSY AFTERNOON OF TS ACTIVITY IS EXPECTED TO OCCUR TODAY BEFORE A SIGNIFICANT DRYING TREND TAKES HOLD FROM MONDAY ONWARD INTO THE MIDDLE OF THIS WEEK. THE PARENT UPPER LOW THAT BROUGHT THE MOISTURE SURGE INTO THE REGION THE LAST FEW DAYS IS NOW MAKING ITS CLOSEST APPROACH AS IT MOVES SLOWLY NORTHWARD INTO SOUTHERN CA. A WEAK VORT LOBE CAN BE SEEN ON WATER VAPOR IMAGERY SLOWLY ROTATING NORTHWARD AROUND THE UPPER LOW CENTER INTO SOUTHWEST AZ. LATEST NAM AND GFS FCST SOUNDINGS ARE SHOWING A 30KT SOUTHERLY JET MAX AT 500MB MOVING INTO SOUTHERN AZ THIS AFTERNOON. THIS MODEST VERTICAL SHEAR...COMBINED WITH AMPLE LOW-LEVEL MOISTURE...AND MODEST MUCAPES...IN THE 500-750 J/KG RANGE...WILL LIKELY BE ENOUGH TO TRIGGER SCATTERED-NUMEROUS THUNDERSTORMS THIS AFTERNOON ACROSS YUMA...LA PAZ...AND WESTERN MARICOPA COUNTY...WITH SOMEWHAT LESS CHANCES ACROSS EASTERN MARICOPA COUNTY. THE MAIN THREAT FROM THIS STORMS WILL BE STRONG WINDS AND BRIEF HEAVY DOWNPOURS...SINCE THEY WILL TEND TO BE FASTER MOVING THEN THE STORMS WE SAW YESTERDAY...WITH DECENT UPPER-LEVEL SHEAR ENHANCING TS DOWNBURSTS. THE LATEST FEW RUNS OF THE HRRR ARE INDICATING THAT MOST OF THE ACTIVITY ACROSS SW AND SOUTH-CENTRAL ARIZONA WILL BE OCCURRING THIS AFTERNOON AND EARLY EVENING...WITH A SHARP REDUCTION IN TS ACTIVITY BY LATE THIS EVENING ONCE THE VORT LOBE PASSES TO OUR NORTH. THE AREA OF GREATEST CONCERN TODAY CONTINUES TO BE SE CA...WHERE THE COMBINATION OF DEEPER MOISTURE AND A MORE UNSTABLE AIRMASS CLOSER TO THE UPPER LOW CENTER IS EXPECTED TO PRODUCE WIDESPREAD TS DEVELOPMENT...WITH HEAVY RAIN AND FLOODING TO BE THE GREATEST ISSUE...WITH RAINFALL AMOUNTS LOCALLY IN THE 1 TO 2 INCH RANGE POSSIBLE...AND FLASH FLOODING/URBAN AND SMALL STREAM FLOODING. ALONG WITH THE HEAVY RAIN AND EVEN SOME SMALL HAIL...THERE COULD ALSO BE LOCALLY STRONG WINDS AS WET MICROBURSTS REACH THE SFC. TS ACTIVITY OVER THIS REGION IS THEN EXPECTED TO CONTINUE INTO THE EARLY EVENING HOURS BEFORE DIMINISHING AS THE UPPER LOW MOVES OFF TO THE NORTH. MONDAY... THE UPPER LOW CONTINUES MOVING NORTHWARD AND WEAKENS WITH TIME. ONE LAST WAVE IS PROGGED TO TRACK ACROSS SOUTHEAST CALIFORNIA AND INTO ARIZONA MONDAY BUT IT WEAKENS IN THE PROCESS. MEANWHILE...DRIER AIR FILTERS INTO THE AREA. THUS POPS FOR MONDAY TREND DOWN...ESPECIALLY OVER SOUTHEAST CALIFORNIA. TUESDAY THROUGH SATURDAY... DRY SOUTHWEST FLOW ALOFT WILL LEAD TO FURTHER DECLINE OF STORM CHANCES WITH ONLY VERY SLIGHT CHANCES OVER THE HIGHER TERRAIN EAST OF PHOENIX TUESDAY AND WEDNESDAY. FOR THE LATTER HALF OF THE WEEK...BOTH GFS AND ECMWF DEPICT A MOIST ADVECTION TREND AND THUS AN EAST TO WEST TREND OF SLIGHT CHANCE POPS OVER THE FORECAST AREA...STOPPING SHORT OF THE LOWER COLORADO RIVER VALLEY. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...KSDL... SKIES WILL REMAIN MOSTLY CLEAR THROUGH MUCH OF THE MORNING HOURS BEFORE SCATTERED CU DEVELOPS AROUND NOON. WIND DIRECTIONS WILL SHIFT TO A SOUTHERLY DIRECTION BY THE AFTERNOON AND GENERALLY STAY MOSTLY SOUTH TO SOUTHWESTERLY UNTIL STORM OUTFLOWS AFFECT THE AREA. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED FROM LATE AFTERNOON THROUGH MID EVENING AND MAY IMPACT AREA TERMINALS FOR A BRIEF TIME. THERE WILL BE THE POTENTIAL FOR STRONG GUSTY OUTFLOW WINDS TODAY AS DRIER AIR AND STRONGER WINDS ALOFT MOVE INTO SOUTHERN ARIZONA BY THIS AFTERNOON. DUE TO LOWER CONFIDENCE IN STORM TIMING AND INTENSITY...WILL CONTINUE TO MENTION JUST VCTS IN THE PHOENIX AREA TAFS...BEGINNING AROUND 22Z. ONCE CONVECTION DEVELOPS AND STORMS START APPROACHING THE TERMINALS...WE WILL UPDATE TAFS AND ADD APPROPRIATE TEMPO GROUPS FOR THUNDER. SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA......KIPL...AND KBLH... UPPER LEVEL LOW OVER THE NORTHERN BAJA INTO FAR SOUTHERN CALIFORNIA COAST WILL CONTINUE TO SUPPORT ISOLATED TO SCATTERED AND THUNDERSTORM ACTIVITY THIS AFTERNOON AND EARLY EVENING. EXPECTING THUNDERSTORM DEVELOPMENT AFTER 21Z...AND HAVE FAIRLY HIGH CONFIDENCE OF AFFECTING AREA TERMINALS AT LEAST FOR A BRIEF TIME LATER THIS AFTERNOON. STRONG GUSTY WINDS IN AND AROUND THUNDERSTORMS WILL BE THE MAIN THREAT...AND VISIBILITY MAY BE BRIEFLY AND SHARPLY REDUCED DUE TO LOCALLY HEAVY RAIN AND OR BLOWING DUST. THE UPPER LOW WILL PULL OUT OF THE AREA THIS EVENING LEAVING CLEARING SKIES AND WEST TO SOUTHWESTERLY WINDS. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... TUESDAY THROUGH SATURDAY... A DRY START TO THE FORECAST PERIOD IS EXPECTED WITH ONLY SLIGHT CHANCES OF STORMS CONFINED TO HIGHER TERRAIN AREAS NORTH AND EAST OF PHOENIX. THIS DRY AIR WILL LIKELY LAST THROUGH THURSDAY AND POTENTIALLY LONGER...RESULTING IN AFTERNOON MINIMUM HUMIDITY VALUES IN THE TEENS. A GRADUAL INCREASE IN MOISTURE SHOULD BEGIN EITHER FRIDAY OR SATURDAY ALLOWING FOR A CHANCE OF STORMS INTO THE SOUTH-CENTRAL ARIZONA DESERTS. HIGH TEMPERATURES WILL BE RIGHT AROUND NORMAL FOR THE ENTIRE PERIOD. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...PERCHA/AJ AVIATION....KUHLMAN/CB FIRE WEATHER...KUHLMAN
AREA FORECAST DISCUSSION...UPDATED
NWS PHOENIX AZ
1020 AM MST SUN AUG 3 2014 .UPDATE...UPDATED AVIATION DISCUSSION. && .SYNOPSIS... EXPECT LESS CLOUDINESS THIS MORNING BEFORE THUNDERSTORM ACTIVITY BEGINS TO DEVELOP IN THE AFTERNOON AS AN UPPER LOW CONTINUES TO AFFECT THE REGION TODAY. FOR THE LOWER DESERTS...BEST CHANCES FOR SHOWERS AND THUNDERSTORMS WILL BE OVER SOUTHEAST CALIFORNIA AND PORTIONS OF SOUTHWEST ARIZONA. STORM CHANCES TREND DOWN MONDAY AS THE LOW SHIFTS NORTHWARD AND WEAKENS. DRY SOUTHWESTERLY FLOW WILL LIMIT STORM CHANCES TO EASTERN ARIZONA TUESDAY AND WEDNESDAY. ANTICIPATE A GRADUAL RETURN OF STORM CHANCES FROM EAST TO WEST DURING THE LATTER HALF OF THE WEEK. && .DISCUSSION... DRIER AIR ALOFT SPREADING IN FROM THE SOUTH BEHIND THE VORT LOBE THAT PRODUCED STORMS OVER SOUTH-CENTRAL AZ HAVE PRETTY MUCH CLEARED SKIES OVER MOST OF OUR CWA THIS MORNING...WITH JUST SOME LINGERING CLOUDINESS CLOSER TO THE PARENT UPPER LOW CENTER OVER SE CA. THESE CLEAR SKIES...COMBINED WITH ABUNDANT LOW-LEVEL MOISTURE...AND ANOTHER WEAK VORT LOBE/JET MAX WILL LIKELY TRIGGER ANOTHER ROUND OF TS ACTIVITY TODAY ACROSS SOUTH-CENTRAL AND SOUTHWEST AZ...WITH EVEN BETTER CHANCES FOR TSTMS ACROSS SE CA THIS AFTERNOON AS THE MAIN UPPER LOW MOVES NORTHWARD OVER SAN DIEGO COUNTY. GIVEN THE FACT THE THE LATEST HRRR CONTINUES TO INDICATE TS DEVELOPMENT OVER WESTERN MARICOPA AND YUMA COUNTIES EARLY THIS AFTERNOON JUST AHEAD OF THE VORT LOBE...HAVE RAISED POPS WELL INTO THE CHANCE RANGE IN THE 18Z-00Z TIME FRAME ACROSS THAT REGION. THE MAIN THREAT FROM THIS STORMS WILL BE STRONG WINDS AND BRIEF HEAVY DOWNPOURS...SINCE THEY WILL TEND TO BE FASTER MOVING THEN THE STORMS WE SAW YESTERDAY...WITH DECENT UPPER-LEVEL SHEAR ENHANCING TS DOWNBURSTS. OTHER THAN THIS INCREASE IN POPS...INHERITED GRIDS ARE HOLDING UP WELL. && .PREVIOUS DISCUSSION... TODAY... UPPER LOW CENTERED NEAR ENSENADA THIS MORNING. SOUTHWESTERLY FLOW ALOFT FURTHER SOUTH OVER BAJA IS SPREADING SOMEWHAT DRIER AIR INTO ARIZONA SUCH THAT SKIES ARE CLEARING FROM THE SOUTH. THIS TREND WILL ENABLE BETTER SURFACE HEATING TO OCCUR TODAY COMPARED TO YESTERDAY. PROGGED CAPE VARIES CONSIDERABLY FROM ONE MODEL TO ANOTHER BUT THE GFS AND NAM BOTH SHOW ROUGHLY 500-750 J/KG OF RELATIVELY SKINNY CAPE OVER MUCH OF OUR FORECAST AREA. NOT SURPRISING SINCE MID LEVELS DONT COOL MUCH. WITH DEEP SOUTHERLY FLOW...PIMA COUNTY WILL NEED TO BE ACTIVE FOR THE SOUTH-CENTRAL ARIZONA DESERTS TO HAVE MUCH ACTIVITY. NEARBY HIGHER TERRAIN WILL HAVE A BETTER OPPORTUNITY. YESTERDAY...THE LOWER DESERTS OF SOUTHWEST ARIZONA AND ESPECIALLY FAR SOUTHEAST CALIFORNIA WERE NOT VERY ACTIVE DUE TO STABLE BOUNDARY LAYERS. TODAY MAY BE THE REVERSE. FOR ONE...THERE WILL BE LESS CLOUDINESS WHICH WILL HELP THE BOUNDARY LAYER TO DESTABILIZE. ALSO...THERE IS ANOTHER VORT LOBE ASSOCIATED WITH THE UPPER LOW THAT IS PROGGED TO MOVE THROUGH TODAY AND PROVIDE SOME MODEST DYNAMICAL FORCING. THIS WILL MAKE CONDITIONS MORE RESPONSIVE TO OUTFLOWS FROM STORMS THAT DEVELOP OVER HIGHER TERRAIN AREAS SUCH AS FAR NORTHERN BAJA AND SAN DIEGO COUNTY. AS A RESULT...THE HI RES MODELS GENERALLY SHOW WESTERN PORTIONS OF THE FORECAST AREA BEING QUITE A BIT MORE ACTIVE THAN EASTERN PORTIONS THIS AFTERNOON...EXCEPT FOR SOUTHERN GILA COUNTY. FORECASTS REFLECT THIS AND IN FACT POPS WERE RAISED OVER SOUTHEAST CALIFORNIA AND PORTIONS OF SOUTHWEST ARIZONA. A LITTLE BIT OF VERTICAL WIND SHEAR AND MORE DCAPE WILL IMPROVE THE CAPABILITY OF THE STORMS TO LAST LONGER AND PRODUCE STRONGER DOWNDRAFTS. THE STRONGEST STORMS WILL HAVE THE POTENTIAL TO PRODUCE BOTH VERY HEAVY RAIN AND DAMAGING WINDS. MONDAY... THE UPPER LOW CONTINUES MOVING NORTHWARD AND WEAKENS WITH TIME. ONE LAST WAVE IS PROGGED TO TRACK ACROSS SOUTHEAST CALIFORNIA AND INTO ARIZONA MONDAY BUT IT WEAKENS IN THE PROCESS. MEANWHILE...DRIER AIR FILTERS INTO THE AREA. THUS POPS FOR MONDAY TREND DOWN...ESPECIALLY OVER SOUTHEAST CALIFORNIA. TUESDAY THROUGH SATURDAY... DRY SOUTHWEST FLOW ALOFT WILL LEAD TO FURTHER DECLINE OF STORM CHANCES WITH ONLY VERY SLIGHT CHANCES OVER THE HIGHER TERRAIN EAST OF PHOENIX TUESDAY AND WEDNESDAY. FOR THE LATTER HALF OF THE WEEK...BOTH GFS AND ECMWF DEPICT A MOIST ADVECTION TREND AND THUS AN EAST TO WEST TREND OF SLIGHT CHANCE POPS OVER THE FORECAST AREA...STOPPING SHORT OF THE LOWER COLORADO RIVER VALLEY. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...KSDL... SKIES WILL REMAIN MOSTLY CLEAR THROUGH MUCH OF THE MORNING HOURS BEFORE SCATTERED CU DEVELOPS AROUND NOON. WIND DIRECTIONS WILL SHIFT TO A SOUTHERLY DIRECTION BY THE AFTERNOON AND GENERALLY STAY MOSTLY SOUTH TO SOUTHWESTERLY UNTIL STORM OUTFLOWS AFFECT THE AREA. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED FROM LATE AFTERNOON THROUGH MID EVENING AND MAY IMPACT AREA TERMINALS FOR A BRIEF TIME. THERE WILL BE THE POTENTIAL FOR STRONG GUSTY OUTFLOW WINDS TODAY AS DRIER AIR AND STRONGER WINDS ALOFT MOVE INTO SOUTHERN ARIZONA BY THIS AFTERNOON. DUE TO LOWER CONFIDENCE IN STORM TIMING AND INTENSITY...WILL CONTINUE TO MENTION JUST VCTS IN THE PHOENIX AREA TAFS...BEGINNING AROUND 22Z. ONCE CONVECTION DEVELOPS AND STORMS START APPROACHING THE TERMINALS...WE WILL UPDATE TAFS AND ADD APPROPRIATE TEMPO GROUPS FOR THUNDER. SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA......KIPL...AND KBLH... UPPER LEVEL LOW OVER THE NORTHERN BAJA INTO FAR SOUTHERN CALIFORNIA COAST WILL CONTINUE TO SUPPORT ISOLATED TO SCATTERED AND THUNDERSTORM ACTIVITY THIS AFTERNOON AND EARLY EVENING. EXPECTING THUNDERSTORM DEVELOPMENT AFTER 21Z...AND HAVE FAIRLY HIGH CONFIDENCE OF AFFECTING AREA TERMINALS AT LEAST FOR A BRIEF TIME LATER THIS AFTERNOON. STRONG GUSTY WINDS IN AND AROUND THUNDERSTORMS WILL BE THE MAIN THREAT...AND VISIBILITY MAY BE BRIEFLY AND SHARPLY REDUCED DUE TO LOCALLY HEAVY RAIN AND OR BLOWING DUST. THE UPPER LOW WILL PULL OUT OF THE AREA THIS EVENING LEAVING CLEARING SKIES AND WEST TO SOUTHWESTERLY WINDS. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... TUESDAY THROUGH SATURDAY... A DRY START TO THE FORECAST PERIOD IS EXPECTED WITH ONLY SLIGHT CHANCES OF STORMS CONFINED TO HIGHER TERRAIN AREAS NORTH AND EAST OF PHOENIX. THIS DRY AIR WILL LIKELY LAST THROUGH THURSDAY AND POTENTIALLY LONGER...RESULTING IN AFTERNOON MINIMUM HUMIDITY VALUES IN THE TEENS. A GRADUAL INCREASE IN MOISTURE SHOULD BEGIN EITHER FRIDAY OR SATURDAY ALLOWING FOR A CHANCE OF STORMS INTO THE SOUTH-CENTRAL ARIZONA DESERTS. HIGH TEMPERATURES WILL BE RIGHT AROUND NORMAL FOR THE ENTIRE PERIOD. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...PERCHA PREVIOUS DISCUSSION...AJ AVIATION....KUHLMAN/CB FIRE WEATHER...KUHLMAN
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
855 AM MST SUN AUG 3 2014 && .SYNOPSIS... EXPECT LESS CLOUDINESS THIS MORNING BEFORE THUNDERSTORM ACTIVITY BEGINS TO DEVELOP IN THE AFTERNOON AS AN UPPER LOW CONTINUES TO AFFECT THE REGION TODAY. FOR THE LOWER DESERTS...BEST CHANCES FOR SHOWERS AND THUNDERSTORMS WILL BE OVER SOUTHEAST CALIFORNIA AND PORTIONS OF SOUTHWEST ARIZONA. STORM CHANCES TREND DOWN MONDAY AS THE LOW SHIFTS NORTHWARD AND WEAKENS. DRY SOUTHWESTERLY FLOW WILL LIMIT STORM CHANCES TO EASTERN ARIZONA TUESDAY AND WEDNESDAY. ANTICIPATE A GRADUAL RETURN OF STORM CHANCES FROM EAST TO WEST DURING THE LATTER HALF OF THE WEEK. && .DISCUSSION... DRIER AIR ALOFT SPREADING IN FROM THE SOUTH BEHIND THE VORT LOBE THAT PRODUCED STORMS OVER SOUTH-CENTRAL AZ HAVE PRETTY MUCH CLEARED SKIES OVER MOST OF OUR CWA THIS MORNING...WITH JUST SOME LINGERING CLOUDINESS CLOSER TO THE PARENT UPPER LOW CENTER OVER SE CA. THESE CLEAR SKIES...COMBINED WITH ABUNDANT LOW-LEVEL MOISTURE...AND ANOTHER WEAK VORT LOBE/JET MAX WILL LIKELY TRIGGER ANOTHER ROUND OF TS ACTIVITY TODAY ACROSS SOUTH-CENTRAL AND SOUTHWEST AZ...WITH EVEN BETTER CHANCES FOR TSTMS ACROSS SE CA THIS AFTERNOON AS THE MAIN UPPER LOW MOVES NORTHWARD OVER SAN DIEGO COUNTY. GIVEN THE FACT THE THE LATEST HRRR CONTINUES TO INDICATE TS DEVELOPMENT OVER WESTERN MARICOPA AND YUMA COUNTIES EARLY THIS AFTERNOON JUST AHEAD OF THE VORT LOBE...HAVE RAISED POPS WELL INTO THE CHANCE RANGE IN THE 18Z-00Z TIME FRAME ACROSS THAT REGION. THE MAIN THREAT FROM THIS STORMS WILL BE STRONG WINDS AND BRIEF HEAVY DOWNPOURS...SINCE THEY WILL TEND TO BE FASTER MOVING THEN THE STORMS WE SAW YESTERDAY...WITH DECENT UPPER-LEVEL SHEAR ENHANCING TS DOWNBURSTS. OTHER THAN THIS INCREASE IN POPS...INHERITED GRIDS ARE HOLDING UP WELL. && .PREVIOUS DISCUSSION... TODAY... UPPER LOW CENTERED NEAR ENSENADA THIS MORNING. SOUTHWESTERLY FLOW ALOFT FURTHER SOUTH OVER BAJA IS SPREADING SOMEWHAT DRIER AIR INTO ARIZONA SUCH THAT SKIES ARE CLEARING FROM THE SOUTH. THIS TREND WILL ENABLE BETTER SURFACE HEATING TO OCCUR TODAY COMPARED TO YESTERDAY. PROGGED CAPE VARIES CONSIDERABLY FROM ONE MODEL TO ANOTHER BUT THE GFS AND NAM BOTH SHOW ROUGHLY 500-750 J/KG OF RELATIVELY SKINNY CAPE OVER MUCH OF OUR FORECAST AREA. NOT SURPRISING SINCE MID LEVELS DONT COOL MUCH. WITH DEEP SOUTHERLY FLOW...PIMA COUNTY WILL NEED TO BE ACTIVE FOR THE SOUTH-CENTRAL ARIZONA DESERTS TO HAVE MUCH ACTIVITY. NEARBY HIGHER TERRAIN WILL HAVE A BETTER OPPORTUNITY. YESTERDAY...THE LOWER DESERTS OF SOUTHWEST ARIZONA AND ESPECIALLY FAR SOUTHEAST CALIFORNIA WERE NOT VERY ACTIVE DUE TO STABLE BOUNDARY LAYERS. TODAY MAY BE THE REVERSE. FOR ONE...THERE WILL BE LESS CLOUDINESS WHICH WILL HELP THE BOUNDARY LAYER TO DESTABILIZE. ALSO...THERE IS ANOTHER VORT LOBE ASSOCIATED WITH THE UPPER LOW THAT IS PROGGED TO MOVE THROUGH TODAY AND PROVIDE SOME MODEST DYNAMICAL FORCING. THIS WILL MAKE CONDITIONS MORE RESPONSIVE TO OUTFLOWS FROM STORMS THAT DEVELOP OVER HIGHER TERRAIN AREAS SUCH AS FAR NORTHERN BAJA AND SAN DIEGO COUNTY. AS A RESULT...THE HI RES MODELS GENERALLY SHOW WESTERN PORTIONS OF THE FORECAST AREA BEING QUITE A BIT MORE ACTIVE THAN EASTERN PORTIONS THIS AFTERNOON...EXCEPT FOR SOUTHERN GILA COUNTY. FORECASTS REFLECT THIS AND IN FACT POPS WERE RAISED OVER SOUTHEAST CALIFORNIA AND PORTIONS OF SOUTHWEST ARIZONA. A LITTLE BIT OF VERTICAL WIND SHEAR AND MORE DCAPE WILL IMPROVE THE CAPABILITY OF THE STORMS TO LAST LONGER AND PRODUCE STRONGER DOWNDRAFTS. THE STRONGEST STORMS WILL HAVE THE POTENTIAL TO PRODUCE BOTH VERY HEAVY RAIN AND DAMAGING WINDS. MONDAY... THE UPPER LOW CONTINUES MOVING NORTHWARD AND WEAKENS WITH TIME. ONE LAST WAVE IS PROGGED TO TRACK ACROSS SOUTHEAST CALIFORNIA AND INTO ARIZONA MONDAY BUT IT WEAKENS IN THE PROCESS. MEANWHILE...DRIER AIR FILTERS INTO THE AREA. THUS POPS FOR MONDAY TREND DOWN...ESPECIALLY OVER SOUTHEAST CALIFORNIA. TUESDAY THROUGH SATURDAY... DRY SOUTHWEST FLOW ALOFT WILL LEAD TO FURTHER DECLINE OF STORM CHANCES WITH ONLY VERY SLIGHT CHANCES OVER THE HIGHER TERRAIN EAST OF PHOENIX TUESDAY AND WEDNESDAY. FOR THE LATTER HALF OF THE WEEK...BOTH GFS AND ECMWF DEPICT A MOIST ADVECTION TREND AND THUS AN EAST TO WEST TREND OF SLIGHT CHANCE POPS OVER THE FORECAST AREA...STOPPING SHORT OF THE LOWER COLORADO RIVER VALLEY. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...KSDL... SKIES WILL REMAIN MOSTLY CLEAR THROUGH MUCH OF THE MORNING HOURS BEFORE SCATTERED CU DEVELOPS AROUND NOON. WIND DIRECTIONS WILL SHIFT TO A SOUTHERLY DIRECTION BY THE AFTERNOON AND GENERALLY STAY MOSTLY SOUTH TO SOUTHWESTERLY UNTIL STORM OUTFLOWS AFFECT THE AREA. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED FROM LATE AFTERNOON THROUGH MID EVENING AND MAY IMPACT AREA TERMINALS FOR A BRIEF TIME. THERE WILL BE THE POTENTIAL FOR STRONG GUSTY OUTFLOW WINDS TODAY AS DRIER AIR AND STRONGER WINDS ALOFT MOVE INTO SOUTHERN ARIZONA BY THIS AFTERNOON. SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA......KIPL...AND KBLH... UPPER LEVEL LOW OVER THE NORTHERN BAJA INTO FAR SOUTHERN CALIFORNIA COAST WILL CONTINUE TO SUPPORT ISOLATED SHOWER ACTIVITY THROUGH THE MORNING HOURS. EXPECTING SOME ISOLATED TO SCATTERED THUNDERSTORM DEVELOPMENT AFTER 21Z...AND HAVE FAIRLY HIGH CONFIDENCE OF AFFECTING AREA TERMINALS AT LEAST FOR A BRIEF TIME LATE THIS AFTERNOON. STRONG GUSTY WINDS IN AND AROUND THUNDERSTORMS WILL BE THE MAIN THREAT. THE UPPER LOW WILL PULL OUT OF THE AREA THIS EVENING LEAVING CLEARING SKIES AND WEST TO SOUTHWESTERLY WINDS. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... TUESDAY THROUGH SATURDAY... A DRY START TO THE FORECAST PERIOD IS EXPECTED WITH ONLY SLIGHT CHANCES OF STORMS CONFINED TO HIGHER TERRAIN AREAS NORTH AND EAST OF PHOENIX. THIS DRY AIR WILL LIKELY LAST THROUGH THURSDAY AND POTENTIALLY LONGER...RESULTING IN AFTERNOON MINIMUM HUMIDITY VALUES IN THE TEENS. A GRADUAL INCREASE IN MOISTURE SHOULD BEGIN EITHER FRIDAY OR SATURDAY ALLOWING FOR A CHANCE OF STORMS INTO THE SOUTH-CENTRAL ARIZONA DESERTS. HIGH TEMPERATURES WILL BE RIGHT AROUND NORMAL FOR THE ENTIRE PERIOD. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...PERCHA PREVIOUS DISCUSSION...AJ AVIATION....KUHLMAN FIRE WEATHER...KUHLMAN
AREA FORECAST DISCUSSION
NWS EUREKA CA
918 AM PDT SUN AUG 3 2014 .SYNOPSIS...ABOVE NORMAL TEMPERATURES WILL CONTINUE ACROSS THE INTERIOR TODAY. INCREASING MOISTURE AND INSTABILITY WILL HEIGHTEN THE THREAT OF THUNDERSTORMS FOR THE INTERIOR MONDAY AND TUESDAY. MEANWHILE...THE COAST SHOULD ANTICIPATE OVERNIGHT LOW CLOUDS AND FOG. && .UPDATE...WITH LIGHT OFFSHORE FLOW OBSERVED ACROSS THE NORTH THIS MORNING...DID A QUICK UPDATE TO EXPAND THE AREA OF SMOKE ACROSS NORTHERN HUMBOLDT AND DEL NORTE COUNTY TO THE COAST. VISIBLE SATELLITE IMAGERY AND HRRR AEROSOL DRY MASS PRODUCTS ALL SHOW SMOKE FROM AREA WILDFIRES HAS MADE IT WEST TO THE COAST. THE SMOKE SHOULD SLOWLY MIGRATE EAST FROM THE COAST THROUGH THE DAY AS WINDS SWITCH TO THE NORTHWEST. THE REST OF THE FORECAST REMAINS UNCHANGED. STP && .MARINE...9 AM...I DROPPED THE GALE FOR THE SOUTHERN OUTER WATERS THIS MORNING AND CONVERTED IT TO A SMALL CRAFT AS MODELS SHOWING WINDS WELL BELOW GALE. WINDS OVER THE NORTERN OUTER WATERS ARE EXPECTED TO REMAIN STRONG WITH GALE GUSTS. UNFORTUNATELY THERE HAVE NOT BEEN SATELLITE OR MARINE OBSERVATIOSN TO VERIFY THIS WIND FORECAST. ON THE OTHER HAND THE WINDS OVER THE OFFSHORE WATERS HAVE PRODUCED STEEP SEAS THAT ARE TRANSLATING INTO THE NEARSHORE WATERS AND SEAS AT BUOY 14 ARE STEEP 6 FT AT 7 SECONDS SO HOISTED SCA FOR THIS AREA. REST OF FORECAST LOOKS GOOD WITH FRONT DISSPATING OVER THE EASTERN PACIFIC MONDAY INTO TUESDAY WEAKENING THE PRESSURE GRADIENT. DEAN && .PREV DISCUSSION......ISSUED AT 510 AM PDT... SYNOPSIS...ABOVE NORMAL TEMPERATURES WILL CONTINUE ACROSS THE INTERIOR TODAY. INCREASING MOISTURE AND INSTABILITY WILL HEIGHTEN THE THREAT OF THUNDERSTORMS FOR THE INTERIOR MONDAY AND TUESDAY. MEANWHILE...THE COAST SHOULD ANTICIPATE OVERNIGHT LOW CLOUDS AND FOG. DISCUSSION...SIGNIFICANT CHANGES WERE MADE WITH THIS FORECAST PACKAGE. THE PERSISTENT WEATHER PATTERN THAT HAS BEEN IN PLACE WILL REMAIN IN PLACE AT LEAST ONE MORE DAY. NORTHWEST CALIFORNIA IS BETWEEN A RIDGE ACROSS THE INTER-MOUNTAIN WEST AND A TROUGH OFF OF THE WEST COAST. COASTAL CLOUDS SHOULD BURN OFF TODAY AND INLAND TEMPERATURES WILL REMAIN ABOVE NORMAL. THERE WILL BE A SLIGHT CHANCE OF THUNDERSTORMS OVER THE TRINITY ALPS TODAY. MODELS SHOW FAIRLY GOOD INSTABILITY. HOWEVER, MOISTURE AND SHEAR ARE MARGINAL AND CAPPING SHOULD LIMIT SOME OF THE CONVECTION. THAT CHANGES TONIGHT INTO MONDAY AS MODELS SHOW A WEAK UPPER LEVEL LOW FORMING JUST TO OUR SOUTH. THIS LOW WILL MOVE SLIGHTLY TO THE NORTH LATE MONDAY INTO TUESDAY. AS IT DOES, MONSOONAL MOISTURE WILL STREAM IN FROM THE SOUTHEAST. THE PLENTIFUL MOISTURE AND GOOD INSTABILITY COULD GENERATE ISOLATED TO SCATTERED THUNDERSTORMS ACROSS THE INTERIOR MONDAY AND TUESDAY. PWATS AT OR ABOVE 1 INCH MAY ALLOW SOME STORMS TO PRODUCE HEAVY RAIN. LIGHT TO MODERATE BULK SHEAR AND A GENERAL LIGHT OFFSHORE ATMOSPHERIC FLOW PATTERN MAY PREVENT THE STORMS FROM GETTING TOO STRONG. BUT IF THIS CHANGES, THEN THE THREAT WILL CHANGE. THE CONDITIONS WON`T BE AS CONDUCIVE TO THUNDERSTORMS ON WEDNESDAY AS THE LOW BEGINS TO MOVE TO THE EAST. BEYOND THAT, ZONAL FLOW STARTS TO TAKE HOLD. THE INTERIOR CAN EXPECT AT OR ABOVE NORMAL TEMPERATURES AND DRY CONDITIONS. THE COAST CAN EXPECT TEMPERATURES NEAR NORMAL. AVIATION...LIFR TO IFR CONDITIONS OBSERVED ALONG THE COAST THIS MORNING WITH EXTENSIVE STRATUS ALONG BOTH THE REDWOOD AND MENDOCINO COASTS. CONDITIONS HAVE IMPROVED SLIGHTLY TONIGHT OVER LAST NIGHT WITH CIGS AROUND 5 OR 6 HUNDRED FEET WITH P6SM VSBYS. EXPECT LIFR CONDITIONS TO REDEVELOP EARLY THIS MORNING AT BOTH KCEC AND KACV BUT THEN LIFT TO VFR BY EARLY AFTERNOON MUCH LIKE YESTERDAY. MODELS CONTINUE TO INDICATE THAT THIS WILL NOT CHANGE MUCH OVER THE NEXT COUPLE OF DAYS. AS SUCH...HAVE CONTINUED WITH A PERSISTENCE FORECAST. A FEW HOURS OF VFR CONDITIONS ARE POSSIBLE ALONG THE COAST THIS AFTERNOON/EVENING BEFORE COASTAL STRATUS EXPANDS ONCE AGAIN THIS OVERNIGHT. VFR CONDITIONS WILL PREVAIL ACROSS THE INTERIOR. SMOKE FROM AREA WILDFIRES IS EXPECTED TO SPREAD ACROSS MUCH OF THE CWA. MKN MARINE...LITTLE CHANGE IN THE PATTERN WITH PERSISTENT N WINDS CONTINUING WELL INTO THE COMING WEEK AS HIGH PRESSURE OFFSHORE INTERACTS WITH THE INLAND THERMAL TROF. HAVE CONTINUED THE LOW END GALE WARNING THROUGH TONIGHT FOR GUSTS. NO SHIP REPORTS OR SAT WINDS ATTM BUT MODELS CONTINUED TO INDICATE THE TIGHTENING GRADIENT AS EARLIER FORECAST. GRADIENT SLACKENS OFF SLIGHTLY ABOUT TUESDAY AS DISSIPATING FRONT MOVES BY TO THE NORTH WEAKENING THE HIGH. GRADIENT TIGHTENS BACK UP AGAIN LATER IN THE WEEK AND MAY NEED GALE AGAIN IN OUTER WATERS. TROPICAL SYSTEMS MOVING ACROSS THE EASTERN PACIFIC WILL GENERATE SOME LONG PERIOD SOUTHERLY SWELL IN THE 2 FT 14-17 SECOND RANGE. MKN FIRE WEATHER...MONSOONAL MOISTURE STREAMING IN FROM THE SOUTHEAST COMBINED WITH A WEAK UPPER LEVEL LOW JUST TO OUR SOUTH MAY PRODUCE ISOLATED TO SCATTERED THUNDERSTORMS FOR SOME OF THE INLAND DISTRICTS MONDAY AND TUESDAY. PWATS AT OR ABOVE 1 INCH MAY ALLOW SOME STORMS TO PRODUCE HEAVY WETTING RAINS. REGARDLESS, GIVEN THE SCATTERED THREAT OF THESE STORMS, ISSUED A FIRE WEATHER WATCH FOR ZONE 283 ON MONDAY. MORE WATCHES MAY BE NEEDED ON TUESDAY IF THE WEATHER PATTERN REMAINS CONDUCIVE. BUT CONFIDENCE IS NOT HIGH ENOUGH TO ISSUE THEM WITH THIS FORECAST PACKAGE. && .EKA WATCHES/WARNINGS/ADVISORIES... CA...FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING CAZ004. NORTHWEST CALIFORNIA COASTAL WATERS... SMALL CRAFT ADVISORY UNTIL 3 AM PDT MONDAY PZZ450-455-475. GALE WARNING UNTIL 3 AM PDT MONDAY PZZ470. && $$ VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA FOLLOW US ON FACEBOOK AND TWITTER AT: HTTP://WWW.FACEBOOK.COM/NWSEUREKA HTTP://WWW.TWITTER.COM/NWSEUREKA
AREA FORECAST DISCUSSION
NWS SAN JOAQUIN VALLEY - HANFORD CA
306 AM PDT SUN AUG 3 2014 .SYNOPSIS... MONSOONAL MOISTURE WILL CONTINUE TO SURGE NORTH...BRINGING AT LEAST A SLIGHT CHANCE OF SHOWERS/THUNDERSTORMS TO MUCH OF THE AREA THROUGH THE AFTERNOON HOURS. THUNDERSTORM ACTIVITY WILL SHIFT TO THE HIGHER ELEVATIONS LATE TONIGHT INTO EARLY MONDAY. OTHERWISE...NEAR NORMAL DAYTIME HIGH TEMPERATURE WILL BE PRESENT OVER THE REGION THROUGH THE END OF NEXT WEEK WITH A SLIGHT CHANCE OF THUNDERSTORMS OVER THE SIERRA CREST EACH AFTERNOON. && .DISCUSSION...AN UPPER LOW IN SOUTHERN CALIFORNIA IS MOVING QUICKLY NORTHWARD...BRINGING ABUNDANT MOISTURE AND INSTABILITY TO THE AREA. HANFORD RADAR IS ALREADY DETECTING RAIN SHOWERS EXTENDING INTO NORTHERN KERN COUNTY THIS MORNING...AS A SIGNIFICANT MONSOONAL SURGE MAKES ITS WAY NORTHWEST INTO THE AREA. IN FACT...BY 2 AM...BAKERSFIELD HAD PICKED UP A TRACE OF RAIN...SETTING A NEW RAINFALL RECORD FOR THE DAY. IT HAD NEVER RAINED IN BAKERSFIELD ON AUGUST 3RD ACCORDING TO THE RECORD ARCHIVES. THUNDERSTORM ACTIVITY HAS MAINLY BEEN EAST OF THE SIERRA CREST OVERNIGHT...HOWEVER...THERE WAS AT LEAST 1 STRIKE IN FAR EASTERN KERN CO AROUND 2 AM. THUNDERSTORM ACTIVITY IS FORECAST TO INCREASE INTO THE MORNING HOURS...AS MU CAPE VALUES INCREASE OVER NOT ONLY THE HIGHER ELEVATIONS...BUT OVER THE SOUTHERN HALF OF THE VALLEY AS WELL. THE THUNDERSTORM ACTIVITY IS LIKELY TO PEAK LATER THIS MORNING INTO THE EARLY AFTERNOON HOURS...WITH MU CAPE VALUES PEAKING OVER THE SIERRA CREST...WITH VALUES BETWEEN 300 AND 500 J/KG. STORMS THAT DO FORM OVER THE CREST WILL MOVE SOUTHWEST INTO THE EASTERN HALF OF THE VALLEY...WITH THE NAM INDICATING MU CAPE VALUES BETWEEN 100 TO 200 J/KG...SUFFICIENT ENOUGH FOR STRIKES OVER THE VALLEY. IN ADDITION...THE LAST FEW RUNS OF THE HRRR HAVE BEEN VERY CONSISTENT WITH RAIN/THUNDERSTORM ACTIVITY SPREADING INTO NORTHERN FRESNO COUNTY BY 10 AM. FORECASTER CONFIDENCE MEDIUM TO HIGH WITH REGARDS TO THUNDERSTORM ACTIVITY. ADDITIONALLY...PWAT VALUES ARE FORECAST TO INCREASE TO 1.5 INCHES FROM FRESNO COUNTY SOUTHWARD...RESULTING IN FLASH FLOODING CONCERNS...MAINLY FOR THE KERN COUNTY DESERT AND MOUNTAIN. FORECAST MODELS ARE IN GOOD AGREEMENT THAT AREAS IN KERN COUNTY COULD EASILY SEE BETWEEN A QUARTER AND A THIRD OF AN INCH OF RAIN BY THIS AFTERNOON...WITH LOCALLY HIGHER AMOUNTS TO ONE-HALF INCH. WITH RECENT FIRES/BURN SCARS IN MIND...A FLASH FLOOD WATCH WAS ISSUED FOR THESE AREAS AND IS VALID FROM THIS MORNING THROUGH EARLY MONDAY MORNING. FORECASTER CONFIDENCE MEDIUM. ONE LAST INTERESTING THING ABOUT THE FORECAST FOR TODAY...MUCH OF THE AREA HAS LIKELY HIT THEIR FORECAST HIGH TEMPERATURE. FORECAST HIGH TEMPERATURES FOR THE VALLEY WILL GENERALLY RANGE FROM THE UPPER 80S TO MID 90S...BETWEEN 10 AND 15 DEGREES COOLER COMPARED TO YESTERDAY. THUNDERSTORM ACTIVITY IS FORECAST TO SHIFT NORTH THROUGH THE DAY...WITH ACTIVITY MAINLY CONFINED TO THE SIERRA CREST LATE TONIGHT INTO EARLY MONDAY MORNING AS THE UPPER LOW MOVES NORTHEAST INTO CENTRAL CALIFORNIA. AFTER MONDAY MORNING...THE SHORT AND MEDIUM RANGE MODELS ARE IN GOOD AGREEMENT THAT MONSOONAL MOISTURE WILL SHIFT QUICKLY TO THE EAST...WITH THUNDERSTORM ACTIVITY CONFINED TO THE SIERRA CREST EACH AFTERNOON AND EVENING. FORECASTER CONFIDENCE MEDIUM. TEMPERATURES ARE FORECAST TO REBOUND MONDAY INTO THE REST OF THE WORK WEEK...WITH VALLEY TEMPERATURES IN THE MID TO UPPER 90S...NEAR NORMAL FOR THE BEGINNING OF AUGUST. BY FRIDAY...A FEW VALLEY LOCATIONS MAY WARM TO THE CENTURY MARK. && .AVIATION... SCATTERED THUNDERSTORMS CAN BE EXPECTED OVER THE MOUNTAINS THROUGH TONIGHT WITH LOCAL MVFR VISIBILITIES AND CEILINGS. ISOLATED THUNDERSTORMS WILL OCCUR IN THE KERN COUNTY DESERT THROUGH EARLY THIS EVENING. THERE IS A SLIGHT CHANCE OF THUNDERSTORMS OVER THE KERN COUNTY PORTION OF THE SAN JOAQUIN VALLEY AND THE EAST SIDE OF THE SAN JOAQUIN VALLEY AND ADJACENT FOOTHILLS UNTIL 06Z MONDAY. VFR CONDITIONS CAN BE EXPECTED ELSEWHERE ACROSS THE CENTRAL CALIFORNIA INTERIOR DURING THE NEXT 24 HOURS. && .AIR QUALITY ISSUES... ON SUNDAY AUGUST 3 2014... UNHEALTHY IN MADERA COUNTY. UNHEALTHY FOR SENSITIVE GROUPS IN FRESNO COUNTY AND SEQUOIA NATIONAL PARK AND FOREST. FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG && .CERTAINTY... THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS HIGH. THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM. CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT WWW.WEATHER.GOV/HNX/CERTAINTY.PHP /ALL LOWER CASE/ FOR ADDITIONAL INFORMATION AND/OR TO PROVIDE FEEDBACK. && .CLIMATE... RECORDS SITE DATE HI_MAX:YEAR LO_MAX:YEAR HI_MIN:YEAR LO_MIN:YEAR KFAT 08-03 110:1946 80:1976 78:1901 55:1953 KFAT 08-04 110:1889 83:1976 82:1901 53:1956 KFAT 08-05 110:1895 83:1957 79:1998 51:1950 KBFL 08-03 112:1938 81:1953 81:1974 53:1912 KBFL 08-04 109:1901 85:1953 82:1961 53:1903 KBFL 08-05 110:1998 85:1957 80:1998 52:1899 && .HNX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH LATE TONIGHT CAZ095-098-099. && $$ PUBLIC...RILEY AVN/FW...DURFEE SYNOPSIS...RILEY WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
340 AM MDT SUN AUG 3 2014 .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 339 AM MDT SUN AUG 3 2014 MOISTURE CONTINUES LIFTING NORTHWARD INTO THE FOUR CORNERS REGION THIS MORNING WITH A FEW SHOWERS AND ISOLATED THUNDERSTORMS FIRING ALONG WESTWARD PROPAGATING WAVE. HRRR HAS A FAIRLY GOOD HANDLE ON THIS ACTIVITY AND INDICATES A BREAK ARRIVING AFTER 9 AM. CELLS QUICKLY REFIRE BY EARLY THIS AFTERNOON AS A STRONGER WAVE LIFTS SLOWLY NORTH OUT OF ARIZONA AND ACROSS WESTERN UTAH. NEW MODEL RUNS CONTINUE TO SLIDE THIS WAVE A BIT TO OUR WEST...RESULTING IN BEST DYNAMIC FORCING ALONG AND TO THE WEST OF OUR EASTERN MOST UTAH ZONES. WITH EDGE OF DEEPER MOISTURE ROTATING IN AND FORCING FROM APPROACHING WAVE...EXPECT POTENTIAL FOR HEAVY RAIN AND FLASH FLOODING WILL BE ON THE RISE LATE THIS AFTERNOON AND THROUGH THE EVENING HOURS...MAINLY ACROSS SOUTHEAST UTAH. FCST PRECIPITABLE WATER VALUES EXCEED 1.25 INCHES...OR CLOSE TO 3 STANDARD DEVIATIONS ABOVE NORMAL FOR THIS TIME OF YEAR. K INDEX VALUES ALSO ECLIPSING 40...INDICATING SUFFICIENTLY DEEP MOISTURE AND COMMON DURING FLASH FLOODS EVENTS. WILL GO AHEAD AND ISSUE A FLASH FLOOD WATCH FOR MUCH OF SOUTHEAST UTAH BEGINNING AROUND MID AFTERNOON AND CONTINUING UNTIL MIDNIGHT TONIGHT WHERE LOCAL RAINFALL AMOUNTS MAY EXCEED AN INCH IN A SHORT PERIOD OF TIME. ELSEWHERE...EXPECT A FAIRLY QUIET START TO THE DAY AS WE AWAIT THE ARRIVAL OF THE DEEPER MOISTURE. SHOULD SEE SHOWERS AND THUNDERSTORMS FIRE OVER THE SAN JUANS BY EARLY THIS AFTERNOON AND GRADUALLY FILL IN AND LIFT NORTH AS THE DAY PROGRESSES. WITH INCREASING MOISTURE...SURFACE AND ALOFT...AND INCREASED CLOUD COVER...TEMPS WILL BE DOWN A COUPLE DEGREES FROM READINGS YESTERDAY. THE POSSIBILITY OF LOCALLY HEAVY RAIN IS PRESENT TONIGHT AND MONDAY. MOISTURE CONTINUES TO SPREAD NORTH ACROSS THE FORECAST AREA TONIGHT. PRECIPITABLE WATER VALUES RUNNING 1+ INCH WITH SURFACE DEWPOINTS RISING INTO THE 50S AS THE LOWER LEVELS MOISTENS...BOTH COMPONENTS FOR AN INCREASED CHANCE OF LOCALLY HEAVY RAIN WITH THE ADDED CONCERN OF POSSIBLE LOCALIZED FLOODING AT NIGHT WHEN IT IS MORE DIFFICULT TO SEE. MODELS KEEP THE MAIN UPPER LOW CIRCULATION OVER WESTERN NV... BUT THE NAM/GFS SHOW AN EJECTING SHORTWAVE LIFTING ACROSS SUNDAY EVENING. SOME UNCERTAINTY IN TIMING AND EASTWARD EXTENT OF ITS TRACK...BUT SHOULD IT MATERIALIZE IT COULD CONTRIBUTE TO NOCTURNAL CONVECTION ACROSS ERN UT INTO WRN CO. BLENDED IN 25% OF THE 21Z SREF TO BUMP UP THE CHANCE OF RAIN FOR MOST AREAS TONIGHT. 40KT SPEED MAX AT 300 MB SLIDES OVERHEAD MONDAY AFTERNOON FOR CONTINUED SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS. CLOUDS AND SHOWERS WILL KEEP TEMPS BELOW NORMAL. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 339 AM MDT SUN AUG 3 2014 THE UPPER LEVEL DISTURBANCE EXITS WRN CO TO THE NE BY LATE MONDAY EVENING. MAIN LOW STILL OVER NRN CA/NRN NV BY TUE MORNING...WITH ANOTHER TROUGH ROTATING AROUND IT AND POSSIBLY LIFTING ACROSS OUR AREA TOWARD 12Z TUE. NOT CONFIDENT IN THESE FEATURES OR THEIR TIMING...SO WILL KEEP A CHANCE OF SHOWERS AND THUNDERSTORMS PRESENT TUESDAY. MONSOONAL FLOW GETS CUTOFF WEDNESDAY WITH HIGH PRESSURE BUILDING OVER THE CENTRAL ROCKIES. RIDGE AXIS SPLITS COLORADO WITH SOUTHWEST FLOW BECOMING ESTABLISHED BY WEDNESDAY AFTERNOON. WILL CARRY LOW POPS FOR MOUNTAIN CONVECTION THAT WORKS ON LINGERING LOW LEVEL MOISTURE...OTHERWISE A DRY DAY APPEARS IN STORE. THE RIDGE SLIDES EAST THURSDAY AS A PACIFIC SYSTEM PUSHES ACROSS THE NORTHERN GREAT BASIN. THIS WILL BRING ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS TO EASTERN UTAH AND WESTERN COLORADO THURSDAY AND FRIDAY...ALTHOUGH COVERAGE IS NOT EXPECTED TO BE AS WIDESPREAD AND STORMS WILL NOT GENERATE AS MUCH RAINFALL WITH PRECIPITABLE WATER VALUES UNDER THREE QUARTERS OF AN INCH. HOWEVER...COOLING ALOFT AND WEAK TO MODERATE SHEAR PROFILE COULD TRIGGER A FEW STRONGER STORMS. ONCE THIS WAVE EXITS LATE FRIDAY...RIDGING ONCE AGAIN SETS UP OVER THE ROCKIES WITH TROUGHING ALONG THE WEST COAST...KEEPING EASTERN UTAH AND WESTERN COLORADO CUTOFF FROM THE DEEPER MONSOONAL MOISTURE TO OUR SOUTH. TEMPS WILL BE MODERATE UPWARD THROUGH THE PERIOD WITH AFTERNOON HIGHS CLIMBING BACK TO NORMAL FOR THIS TIME OF SEASON. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 339 AM MDT SUN AUG 3 2014 SHOWERS AND THUNDERSTORMS WILL GRADUALLY SPREAD NORTH AND EAST ACROSS EASTERN UTAH AND WESTERN COLORADO TODAY AS DEEPER MOISTURE LIFTS NORTH. A STRONGER DISTURBANCE ARRIVES LATE THIS AFTERNOON AND EVENING. THIS WILL ENHANCE SHOWERS AND THUNDERSTORMS...WITH SOME STORMS PRODUCING VERY HEAVY RAINFALL AND GUSTY WINDS TO 40 MPH. EXPECT FREQUENT MOUNTAIN OBSCURATIONS AFTER 19Z THIS AFTERNOON WITH LOCAL MVFR CIGS AND VSBYS NEAR THE STRONGEST STORMS. ALL TERMINAL SITES WILL SEE AT LEAST A 50 PERCENT CHANCE OF BEING IMPACTED BETWEEN 19Z AND 06Z TONIGHT. && .HYDROLOGY... ISSUED AT 339 AM MDT SUN AUG 3 2014 DEEP SURGE OF MONSOONAL MOISTURE WILL LIFT NORTH AND WEST ACROSS EASTERN UTAH AND WESTERN COLORADO THIS AFTERNOON AND TONIGHT. AT THE SAME TIME...A STRONG UPPER LEVEL DISTURBANCE WILL MOVE INTO THE AREA BY 3 PM MDT...RESULTING IN RAPID DEVELOPMENT OF SHOWERS AND HEAVY RAIN PRODUCING THUNDERSTORMS...ESPECIALLY ACROSS PORTIONS OF SOUTHEAST UTAH. AS A RESULT...A FLASH FLOOD WATCH HAS BEEN ISSUED FOR MUCH OF SOUTHEAST UTAH BEGINNING AT 3 PM THIS AFTERNOON AND CONTINUING UNTIL MIDNIGHT TONIGHT. RAINFALL RATES EXCEEDING ONE INCH PER HOUR CAN BE EXPECTED AND MAY LEAD TO FLASH FLOODING OF SLOT CANYONS AND AREAS NEAR OLD FIRE SCARS. ARCHES AND CANYONLANDS NATIONAL PARKS ARE BOTH INCLUDED IN THIS FLASH FLOOD WATCH. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...NONE. UT...FLASH FLOOD WATCH FROM 3 PM MDT THIS AFTERNOON THROUGH THIS EVENING FOR UTZ022-025-027-029. && $$ SHORT TERM...JDC/JAD LONG TERM...JAD/JDC AVIATION...JDC HYDROLOGY...JDC
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1024 PM EDT MON AUG 4 2014 .SYNOPSIS... NEAR OR JUST BELOW NORMAL TEMPERATURES ARE EXPECTED THIS WEEK. WHILE MOST OF THE TIME WILL BE DRY...A FEW ROUNDS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE EXPECTED...WITH THE MOST WIDESPREAD ACTIVITY ON WEDNESDAY. HIGH PRESSURE BUILDS OVER THE REGION FOR THE WEEKEND. MEANWHILE...HURRICANE BERTHA IS EXPECTED TO PASS ABOUT 300 MILES SOUTHEAST OF NANTUCKET TUESDAY NIGHT. THIS WILL HAVE LITTLE IMPACT ON OUR REGION OTHER THAN POTENTIAL FOR HIGH SURF AND DANGEROUS RIP CURRENTS. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... 1030 PM UPDATE... MODERATE CONFIDENT FORECAST. COMBINATION OF HIGH DEWPOINTS ALONG WITH LIGHT WINDS...AND NOTING CROSSOVER THRESHOLDS /WHETHER LOW TEMPERATURES WILL FALL LOWER THAN THE OBSERVED DEWPOINT AT MAX HEATING OF THE DAY/...WOULD SUGGEST WIDESPREAD FOG ACROSS MUCH OF SOUTHERN NEW ENGLAND. SURPRISINGLY THE HRRR DOES NOT FOLLOW THIS TREND KEEPING DENSE FOG OVER THE WATERS AND ADJACENT S-SHORELINES INCLUDING CAPE ANN. RAP EXHIBITS A SIMILAR TREND WITH H975 RH CONFINED TO THE AFOREMENTIONED AREAS. ONE DIFFERENCE AS TO THE FORECAST FOG TREND AND MONDAY MORNINGS DENSE FOG IS THE FACT THAT THERE IS NO ANTECEDANT RAIN. CONDITIONS TODAY WERE ALLOWED TO DRY OUT AND TEMPERATURES WERE CONSIDERABLY WARMER WITH REGARDS TO HIGHS...ESPECIALLY ALONG THE SHORELINES. HAVE TRENDED WITH THE HRRR WITH REGARDS TO FOG. GONE AHEAD WITH A SPECIAL WEATHER STATEMENT FOR THOSE AREAS CONFIDENT ENOUGH IN SEEING FOG /SOUTH- AND SOUTHEAST-SHORELINES OF NEW ENGLAND ALONG WITH ADJACENT ISLANDS...AS WELL AS CAPE ANN/. BETTER TO BE PRO- ACTIVE AND GIVE A HEADS UP AS TO THE POTENTIAL...ESPECIALLY AS IT MAY HAVE IMPACTS ON THE MORNING COMMUTE...ALONG WITH THE POTENTIAL UPGRADE FOR A DENSE FOG ADVISORY. EXPECT OVERNIGHT LOWS TO RANGE FROM AROUND 60 ACROSS SW NH/NW MA TO THE MID-UPPER 60S ALONG THE S COAST. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... TUESDAY... AS THE H5 TROUGH REMAINS W OF THE REGION...LOOKS LIKE THERE WILL BE A BRIEF BREAK IN THE DIURNAL PRECIP. LOWER PWATS MOVE ACROSS...AROUND 1 INCH...SO THIS WILL INHIBIT MORE WIDESPREAD PRECIP ACTIVITY. ALSO NOTING LOW RH VALUES BETWEEN H85 AND H3 ACROSS MOST OF THE REGION /30-40 PERCENT/...SO WILL UNDERCUT ANY DEEP LAYER CONVECTION. MAY SEE SOME ISOLD SHOWERS TRY TO DEVELOP WELL INLAND DURING THE AFTERNOON...SO HAVE CARRIED SLIGHT CHANCE POPS FROM NE AND CENTRAL MA TO THE CT VALLEY...THOUGH PRECIP AMOUNTS WILL BE LIGHT. WILL STILL SEE DEWPTS IN THE 60S...HIGHEST ALONG THE S COAST...SO WILL BE ANOTHER WARM AND HUMID DAY. EXPECT TEMPS TO TOP OFF IN THE LOWER-MID 80S FOR MOST AREAS...EXCEPT THE 70S ALONG THE IMMEDIATE S COAST WITH GENERALLY LIGHT SOUTHERLY WINDS. TUESDAY NIGHT... ANOTHER SOUPY NIGHT IN STORE WITH STAGNANT AIRMASS STILL IN PLACE. ANY SHOWERS SHOULD MELT AWAY IN THE EVENING...THOUGH NOTING INCREASING MID LAYER RH VALUES ACROSS S NH/N AND W MA OVERNIGHT. MIGHT SEE WIDELY SCT SHOWERS LINGER THERE AS H5 TROUGH STARTS TO SLIDE E AFTER MIDNIGHT. LACK OF DAYTIME HEATING WILL LOWER RISK OF SHOWERS. WILL STILL SEE OVERNIGHT REDEVELOPMENT OF PATCHY FOG AND LOW CLOUDS. LOWS WILL MAINLY BE IN THE 60S...THOUGH THE URBAN CENTERS MIGHT STAY CLOSE TO 70. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... BIG PICTURE...UPPER TROUGH OVER THE GREAT LAKES MIGRATES EAST WEDNESDAY AND CROSSES NEW ENGLAND THURSDAY AND FRIDAY...MOVING A LITTLE SLOWER THAN WAS DEPICTED THIS TIME YESTERDAY. UPPER RIDGE THEN BUILDS OVER THE NORTHEAST USA FOR THE WEEKEND AND EARLY NEXT WEEK. HURRICANE BERTHA WELL TO THE EAST OF FLORIDA MOVES NORTH TONIGHT AND TUESDAY...THEN CURVES OUT TO SEA WEDNESDAY AND THURSDAY. THE DAILIES... WEDNESDAY...COLD FRONT MOVES ACROSS SOUTHERN NEW ENGLAND AS THE REGION FALLS UNDER THE LEFT EXIT REGION OF THE UPPER JET. INTERESTING BLEND OF VALUES FROM THE GFS AND ECMWF: WINDS AT 500 MB 30-35 KNOTS...WINDS AT 850 MB 10-15 KNOTS...THETA-E RIDGE RI AND SE MASS...MODEL SBCAPE 500-1000 J/KG...TOTALS 49-51...MID LEVEL LAPSE RATES 6.25-6.5C/KM. PRECIP WATER VALUES 1-1.5 INCHES WITH HIGHEST VALUES ACROSS RI AND SOUTHEAST MASS. WHAT THE GFS AND ECMWF HAVE TROUBLE WITH IS THE SEA LEVEL PRESSURE PATTERN. BOTH SHOW THE FRONT MOVING TO THE SOUTH COAST BY 12Z WEDNESDAY...THEN JUMPING BACKWARD OVER SOUTHERN NEW ENGLAND AGAIN DURING THE DAY. DIFFICULT TO READ THE MODEL OUTPUT LITERALLY. RATHER...WILL EXPECT A COLD FRONT OVER THE REGION SUPPLYING LOW LEVEL CONVERGENCE...UPPER JET SUPPLYING HIGH LEVEL DIVERGENCE...AND SUFFICIENT INSTABILITY AND MOISTURE TO TAP FOR THUNDERSTORM DEVELOPMENT. PRECIP WATER VALUES ARE NOT EXCESSIVE FOR AUGUST...BUT COULD GENERATE BRIEF HEAVY DOWNPOURS ESPECIALLY ACROSS RI AND SOUTHEAST MASS. ALSO OF CONCERN IS BERTHA WHICH PASSES WELL OFFSHORE. THE BROAD UPPER TROUGH WITH A WSW-ENE FLOW OVER THE OCEAN WOULD SUGGEST THE STORM IS NOT A DIRECT THREAT TO SOUTHERN NEW ENGLAND. MODEL RH FIELDS AT 925/850/700 MB SHOW BERTHA/S MOISTURE SHIELD REMAINING OFFSHORE AND MOVING OUT TO SEA BY WEDNESDAY. THIS THREAT SEEMS LOW. THURSDAY-FRIDAY...UPPER TROUGH AND COLD POOL MOVE OVERHEAD. THIS WILL MAINTAIN AN UNSTABLE AIRMASS WITH TOTALS 50-54 MOST AREAS. MIXING IS FORECAST TO REACH 800 MB WITH A MOIST LAYER FOUND ABOVE 850 MB. EXPECT DIURNAL CUMULUS WITH CHANCE POPS FOR A THUNDERSTORM. SATURDAY-SUNDAY-MONDAY... RIDGE BUILDS SURFACE AND ALOFT. WHILE THERE MAY BE SOME DIURNAL CLOUDS...DRY WEATHER SHOULD PREVAIL. TEMPS AT 850 MB CLIMB HIGHER EACH DAY...FROM AROUND 12C FRIDAY TO AROUND 15C MONDAY...WHICH SUPPORTS TEMPS WARMING A LITTLE MORE EACH DAY. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT... 2Z UPDATE... TONIGHT...MODERATE CONFIDENCE. IFR-VLIFR CIGS/VSBYS FOR THE S/SE SHORELINES AND ADJACENT ISLANDS. DETERIORATING AROUND 4-7Z...IMPROVING BY 11Z. LIGHT WINDS...VRB IN MOST PLACES. VFR ELSEWHERE...BUT CONTINUED LOW CONFIDENCE ON AREAL COVERAGE OF FOG. TUESDAY...MODERATE TO HIGH CONFIDENCE. AREAS OF LOW CLOUDS/FOG PATCHES WILL BURN OFF BY LATE MORNING. OTHERWISE...MAINLY VFR CONDITIONS. AN ISOLATED SHOWER/THUNDERSTORM IS POSSIBLE DURING THE AFTERNOON ACROSS THE INTERIOR...THOUGH MOST OF THE REGION WILL REMAIN DRY. TUESDAY NIGHT...MODERATE CONFIDENCE. ANY ISOLD SHOWERS/THUNDERSTORMS WILL DISSIPATE BY 03Z...OTHERWISE VFR. AFTER 04Z-05Z...AREAS OF LOW CLOUDS/FOG DEVELOP AGAIN WITH MVFR-IFR CONDITIONS...EXCEPT EARLY ACROSS CAPE COD AND THE ISLANDS. KBOS TERMINAL...MODERATE CONFIDENCE. LIGHT SEA BREEZE EXPECTED TO DEVELOP BY MIDDAY TUESDAY. KBDL TERMINAL...HIGH CONFIDENCE. OUTLOOK...WEDNESDAY THROUGH SATURDAY...MODERATE CONFIDENCE. WEDNESDAY...AREAS OF EARLY MORNING IFR IN FOG. VFR DURING THE DAY WITH BRIEF MVFR/IFR POSSIBLE IN SHOWERS/THUNDERSTORMS AS A COLD FRONT MOVES THROUGH AND OFFSHORE. THURSDAY-FRIDAY...VFR WITH BRIEF MVFR CIGS/VSBYS POSSIBLE IN SCATTERED AFTERNOON SHOWERS OR THUNDERSTORMS. SATURDAY...VFR. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT... HIGH CONFIDENCE. EXPECT THE CONTINUED WEAK PRESSURE GRADIENT TO KEEP WINDS AND SEAS BELOW SCA THRESHOLDS THROUGH TUESDAY AFTERNOON. THE MAIN CONCERN FOR MARINERS WILL BE AREAS OF FOG...SOME OF WHICH MAY BE LOCALLY DENSE BOTH LATE TONIGHT INTO EARLY TUE MORNING AND AGAIN LATE TUE NIGHT INTO WED MORNING. SWELL FROM HURRICANE BERTHA WILL BEGIN IN ENCROACH THE SOUTHERN OUTER WATERS TUESDAY NIGHT...REACHING AROUND 5 FT MAINLY AFTER MIDNIGHT. THE SWELLS MAY REACH RI AND BI SOUNDS BY DAYBREAK WEDNESDAY. OUTLOOK...WEDNESDAY THROUGH SATURDAY...MODERATE CONFIDENCE. WEDNESDAY...TROPICAL STORM BERTHA PASSES WELL OUTSIDE THE NEW ENGLAND WATERS. A 5-6 FOOT SOUTH SWELL MAY LINGER ON OUR SOUTHERN WATERS DURING WEDNESDAY BUT SHOULD SUBSIDE WEDNESDAY NIGHT. WINDS FROM BERTHA SHOULD REMAIN OUTSIDE OUR WATERS. AREAS OF FOG MAY BRING POOR VISIBILITY WEDNESDAY MORNING. A COLD FRONT WILL CROSS THE WATERS BRINGING SHOWERS AND THUNDERSTORMS. BRIEF WIND GUSTS ABOVE 35 KNOTS ARE POSSIBLE WITH THUNDERSTORMS. THURSDAY-FRIDAY-SATURDAY...HIGH PRESSURE BUILDS FROM THE WEST. LINGERING CHANCE OF A THUNDERSTORM THURSDAY AND FRIDAY... ESPECIALLY NEARSHORE. WINDS AND SEAS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...WTB/EVT NEAR TERM...SIPPRELL SHORT TERM...EVT LONG TERM...WTB AVIATION...WTB/SIPPRELL/EVT MARINE...WTB/EVT
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
621 PM EDT SUN AUG 3 2014 .SYNOPSIS... AN UPPER LOW OVER WESTERN PENNSYLVANIA THIS AFTERNOON WILL LIFT NORTHEAST INTO NEW ENGLAND TONIGHT. MEANWHILE, A FRONTAL BOUNDARY WILL REMAIN POSITIONED OFF THE EAST COAST EARLY THIS WEEK. TROPICAL STORM BERTHA IS FORECAST TO TRACK NORTHWARD OFF THE SOUTHEAST COAST MONDAY BEFORE RE-CURVING TO THE NORTHEAST TUESDAY, WELL EAST OF THE MID-ATLANTIC COAST. A COLD FRONT WILL MOVE THROUGH THE REGION WEDNESDAY. THE FRONT IS EXPECTED TO STALL JUST SOUTH OF THE AREA LATE IN THE WEEK INTO NEXT WEEKEND AS HIGH PRESSURE ATTEMPTS TO BUILD IN FROM THE GREAT LAKES. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... AN UPPER LOW WHICH IS CURRENTLY MOVING SLOWLY ACROSS WRN/CNTRL PA WILL WEAKEN AND MOVE NORTH OF THE REGION TONIGHT. IT HAS CAUSED SHOWERS WITH HEAVY RAINS ACROSS WRN/CNTRL PA SO FAR. SCT SHOWERS ARE POSSIBLE FOR THE REST OF THE AFTERNOON AND INTO THE EVENING WITH THIS FEATURE. RIGHT NOW THE HRRR, RAP AND THE HIRES 18Z NAM ARE TARGETING THE CLUSTERS OF SHOWERS AND THUNDER OVER MARYLAND AND SOUTHERN PA TO MOVE EAST TOWARD THE EASTERN SHORE OF MD AND CHESTER/BERKS COUNTIES PA. FOG IS EXPECTED TO DEVELOP OVERNIGHT...AND WE HAVE INCLUDED AREAS OF FOG IN THE GRIDS. LOWS TONIGHT WILL RANGE FROM THE UPPER 50S NORTH TO THE UPPER 60D SOUTH. MET/MAV MOS TEMPS WERE USED FOR THE FCST. && .SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/... THE WEAK UPPER LOW WILL HAVE MOVED AWAY BY MON MORNING AND WITH HIGH PRESSURE STARTING TO MOVE TOWARD THE AREA...A BETTER WEATHER DAY IS EXPECTED. THERE WILL BE SOME FOG EARLY...BUT DRIER AIR ALOFT WILL LEAD TO AT LEAST PARTLY SUNNY SKIES BY AFTERNOON. SCT SHOWERS WILL PROBABLY DEVELOP DURING THE AFTERNOON...BUT COVERAGE WILL NOT BE AS WIDESPREAD AS THE PAST FEW DAYS. TEMPERATURES WILL JUMP BACK TO NORMAL LEVELS WITH MOSTLY MID 80S ACROSS THE AREA. WINDS WILL BE WRLY/NWRLY AT 5 TO 10 MPH. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... LARGE-SCALE PATTERN WILL FEATURE A PERSISTENT TROUGH OVER THE ERN CONUS THRU MUCH OF THE WEEK. SEVERAL SHORTWAVE DISTURBANCES ROTATING AROUND THE MAIN TROUGH WILL PROVIDE THE CHANCE OF SHOWERS AND THUNDERSTORMS THRU MIDWEEK, PARTICULARLY ON WEDNESDAY WHEN A COLD FRONT MOVES THRU THE CWA. ALSO, DO NOT EXPECT ANY HEATWAVES TO OCCUR ACROSS OUR REGION UNDER THIS SETUP. TEMPS WILL BE NEAR NORMAL THROUGHOUT THE LONG-TERM PERIOD. THE WARMEST DAY EXPECTED IN THE PERIOD IS TUESDAY, BUT MAX TEMPS IN THE MU 80S (PERHAPS REACHING 90F IN A FEW SPOTS) AND MIN TEMPS IN THE MU 60S MONDAY NIGHT AND TUESDAY NIGHT WOULD ONLY BE AT OR A COUPLE OF DEGREES ABOVE NORMAL FOR EARLY AUGUST. MONDAY NIGHT SHOULD BE DRY ACROSS MOST OF THE REGION. TROPICAL STORM BERTHA IS EXPECTED TO INTERACT WITH THE STALLED OFFSHORE BOUNDARY AS IT TRACKS EAST OF THE OUTERBANKS. CANNOT RULE OUT A FEW SHOWERS ON THE NRN PERIPHERY OF THE SYSTEM REACHING THE DELMARVA. BERTHA IS FORECAST BY THE NATIONAL HURRICANE CENTER TO RE-CURVE TO THE NORTHEAST TUESDAY AND TUESDAY NIGHT, WITH A TRACK THAT IS WELL EAST OF THE DELMARVA/NJ COAST. MODEST LIFT PROVIDED BY AN UPSTREAM SHORTWAVE TROUGH MAY YIELD ISO TO SCT SHOWERS/TSTMS ON TUESDAY. CONFINED LOW CHANCE POPS TO THE SOUTHERN TIER OF THE CWA, WHERE DIFFERENTIAL HEATING MAY PROVIDE A FOCUS FOR DIURNAL CONVECTION ON THE NWRN PERIPHERY OF THE TROPICAL SYSTEM AND ALSO IN THE POCONOS, WHERE CONVECTION COULD INITIATE OVER THE HIGHER TERRAIN. A BETTER CHANCE FOR SHOWERS AND STORMS EXPECTED ON WEDNESDAY WHEN A COLD FRONT MOVES THRU THE AREA. LATEST TREND IN THE FCST WAS TO RAISE POPS A BIT TO 40-50 PERCENT SINCE THERE IS BETTER MODEL AGREEMENT REGARDING THE POSITION/TIMING OF THE COLD FRONT, ULVL JET STREAK AND THE UPPER SHORTWAVE TROUGH. IT APPEARS THAT FAVORABLE DYNAMICS FROM THESE FEATURES WILL BECOME JUXTAPOSED OVER THE CWA FOR A PERIOD WEDNESDAY AFTERNOON. THE FRONT IS FORECAST TO GRADUALLY SHIFT SOUTH OF THE AREA WEDNESDAY NIGHT BEFORE STALLING SOMEWHERE NEAR THE NC-VA BORDER LATE IN THE WEEK. ISO SHOWERS POSSIBLE IN EXTREME NERN PA/NRN NJ THURSDAY AFTERNOON AS COLD POOL ASSOCIATED WITH A TROUGH ALOFT PROVIDES SOME INSTABILITY. CONVECTION WOULD BE MAINLY DIURNALLY-DRIVEN, LOW-TOPPED AND ANY COVERAGE OF SHOWERS/STORMS SHOULD BE LOW. MODEL SPREAD DOES INCREASE LATE IN THE PERIOD, PARTICULARLY THIS WEEKEND IN REGARDS TO THE POSITION OF THE BOUNDARY AND THE DEVELOPMENT OF LOPRES ALONG THAT BOUNDARY. ATTM...KEPT THE FCST NEXT WEEKEND DRY, BUT IF MODELS CONTINUE TO TREND FARTHER NORTHWARD, PRECIP CHANCES MAY NEED TO BE ADDED, ESPECIALLY ACROSS THE SRN TIER. && .AVIATION /22Z SUNDAY THROUGH FRIDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. RATHER POOR FLYING CONDITIONS HAVE BEEN ACROSS THE AREA TODAY...MUCH LIKE YESTERDAY. MOSTLY MVFR CIGS HAVE BEEN ACROSS THE DEL VALLEY AND NORTH/WEST. IFR CONDITIONS WITH SOME LIGHT SHOWERS HAVE BEEN ACROSS KMIV/KACY. CIGS HAVE BEEN SLOWLY RISING THE PAST FEW HOURS...SO SOME VFR CONDITIONS WILL LIKELY OCCUR SHORTLY. SAT ALSO SHOWS THIN SPOTS DEVELOPING IN THE OVC. THE IMPROVING CONDITIONS WILL CONTINUE THRU THE EARLY EVENING BEFORE COOLING AND FOG FORMATION IS EXPECTED. WE HAVE CONTINUED WITH THE PREVIOUS FCST FOR THE EVENING...AND THEN FOLLOWED THE GFS LAMP AND HIT THE FOG RATHER HARD FOR THE TAF SITES...ESPECIALLY KMIV/KACY. THE FOG MAY NOT GET AS INTENSE...IF MORE LOW CIGS ROLL IN TONIGHT. MONDAY...AFTER THE FOG BURNS OFF...VFR EXPECTED WITH WEST/NORTHWEST WINDS AROUND 10 KTS BY NOON. OUTLOOK... MONDAY NIGHT AND TUESDAY...PREDOMINATELY VFR WITH LOW CHANCE FOR SHRA/TSRA MAINLY SOUTH OF PHILA TERMINALS. LIGHT WINDS DURING THE PERIOD. TUESDAY NIGHT AND WEDNESDAY...COLD FRONT APPROACHES TUESDAY NIGHT. CHANCE FOR SHRA/TSRA WITH HIGHEST COVERAGE OF CONVECTION EXPECTED WEDNESDAY AFTERNOON AS THE COLD FRONT MOVES THRU. MAINLY VFR BUT LOCAL/TEMPORARY FLIGHT RESTRICTIONS WOULD BE ANTICIPATED IN HEAVIER ACTIVITY. WEDNESDAY NIGHT THROUGH FRIDAY...COLD FRONT MOVES SOUTH OF THE TERMINALS. ATTM, EXPECT A MAINLY DRY PERIOD WITH HIPRES TRYING TO BUILD IN FROM THE GREAT LAKES. && .MARINE... RATHER SHOWERY/FOGGY CONDITIONS ACROSS THE WATERS AS A FRONT AND WAVES OF LOW PRESSURE MOVE ALONG IT. THE FRONT WILL EDGE EASTWARD TONIGHT BRINGING SCT SHOWERS AND LIGHT WINDS. WIND DIRECTIONS WHICH HAVE BEEN MOSTLY NE OR E WILL SWITCH MORE WRLY/NWRLY ON MONDAY. SEAS ON THE OCEAN WILL REMAIN MOSTLY AROUND 3 FT. OVER DEL BAY...SE WINDS WILL BECOME NW MONDAY WITH SPEEDS 5 TO 10 KTS. AREAS OF FOG ARE POSSIBLE TONIGHT WITH LOWER VSBYS. OUTLOOK... MONDAY NIGHT...NO HAZARDS EXPECTED ON THE WATERS. TUESDAY THROUGH WEDNESDAY...TROPICAL STORM BERTHA IS EXPECTED TO TRACK WELL EAST OF THE AREA, BUT IS FORECAST TO PRODUCE WAVES OF 3-4 FT. IF THE TRACK OF BERTHA SHIFTS CLOSER TO THE COAST, LOCALLY HIGHER WAVES MAY REACH SCA CRITERIA. LONG-PERIOD SWELLS OF 10-13 S ARE CURRENTLY FORECAST FOR TUESDAY AND WEDNESDAY. WEDNESDAY NIGHT THROUGH FRIDAY...NO MARINE HEADLINES ARE ANTICIPATED. && .RIP CURRENTS... THERE REMAINS SOME ENHANCED WAVE ACTION ALONG THE COAST THIS AFTERNOON. CONTINUE TO HIGHLIGHT A MODERATE RISK OF RIP CURRENTS THROUGH THIS EVENING. LONG PERIOD SWELLS FROM TROPICAL STORM BERTHA MAY AFFECT THE COASTS OF DELAWARE AND NEW JERSEY FROM LATE MONDAY INTO WEDNESDAY. THE SWELLS COULD BRING AN ENHANCED THREAT FOR DANGEROUS RIP CURRENTS DURING THIS TIME. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...KLEIN NEAR TERM...GAINES/O`HARA SHORT TERM...O`HARA LONG TERM...KLEIN AVIATION...KLEIN/O`HARA MARINE...KLEIN/O`HARA RIP CURRENTS...KLEIN/O`HARA
AREA FORECAST DISCUSSION
NWS MIAMI FL
948 PM EDT MON AUG 4 2014 .UPDATE... ALTHOUGH CONDITIONS HAVE IMPROVED, THE LOW THAT BROUGHT THE SHOWERS AND THUNDERSTORMS TO SOUTH FLORIDA EARLIER TODAY STILL HAS THE POTENTIAL TO BRING ADDITIONAL PRECIP TO THE AREA. THE GULF COAST STILL LOOKS TO BE THE AREA TO HAVE THE BEST CHANCES, ALTHOUGH MUCH LIGHTER ACCUMULATIONS THAN EARLIER. THE MAINLY AND EAST COAST OF SOUTH FLORIDA, AS WELL AS THE ATLANTIC WATERS, MAY SEE SOME SCATTERED SHOWERS DEVELOP THIS EVENING. THE HRRR STILL SHOWS THE POSSIBILITY OF SHOWERS, ALTHOUGH THE GFS AND ECMWF TEND TO KEEP ANY PRECIP ALONG THE COASTAL AREAS. GIVEN THE UNCERTAINTY, HAVE KEPT SCATTERED POPS IN THE FORECAST FOR NOW. && .PREV DISCUSSION... /ISSUED 740 PM EDT MON AUG 4 2014/ AVIATION... DEBRIS CLOUD FIELD FROM LARGE CONVECTIVE COMPLEX WILL GRADUALLY IMPROVE THROUGH THE NIGHT WITH VFR CONDITIONS EXPECTED AT ALL TERMINALS. ABUNDANT MOISTURE TO CONTINUE THROUGH TUESDAY WITH INCREASING THREAT FOR CLOUDS AND TSRA AFT 14-16Z WITH THE GREATEST PROBABILITY NEAR KPBI SO PLACED A PROB30 GROUP IN THEIR TAF FOR THE AFTERNOON. SURFACE WIND WILL BE L/V BECMG SW AT 5-10 KT AFT 14Z ALL SITES. KOB PREV DISCUSSION... /ISSUED 312 PM EDT MON AUG 4 2014/ DISCUSSION... LATEST SURFACE ANALYSIS MAP SHOWS A SURFACE TROUGH AXIS EXTENDING FROM NORTHEASTERN FLORIDA THROUGH COLLIER COUNTY`S COASTLINE. SHOWERS AND THUNDERSTORMS WILL CONTINUE TONIGHT AS THE LOW PRESSURE LOCATED ACROSS NORTHEASTERN FLORIDA PREVAILS. SOUTHERLY SURFACE FLOW WILL CONTINUE ACROSS SOUTH FLORIDA THROUGH AT LEAST THE MIDDLE OF THE WEEK. MOISTURE WILL CONTINUE ABUNDANT AND WARM TEMPERATURES WILL PREVAIL ACROSS THE PENINSULA THROUGH THIS PERIOD. WIND FLOW WILL THEN BECOME WEAK AS HIGH PRESSURE BUILDS ACROSS THE AREA BY WEDNESDAY. WIND FLOW WILL BECOME EASTERLY AND AFTERNOON SHOWERS AND THUNDERSTORMS WILL THEN PREVAIL FROM THAT POINT THROUGH THE WEEKEND AS BOTH COASTS SEA BREEZES DEVELOP AND INTERACT ACROSS THE LAKE REGION. MARINE... BERTHA WILL CONTINUE MOVING NORTH AND AWAY FROM THE BAHAMAS. SOUTHERLY WINDS ARE FORECAST TO REMAIN AROUND 5-15 KTS THROUGH AT LEAST WEDNESDAY. WEAKER WINDS WILL RETURN BY MID WEEK BEFORE A GENERAL SSE TO S FLOW IS PREVALENT BY THE END OF THE WEEK AND THIS WEEKEND. SCATTERED SHOWERS AND STORMS COULD LEAD TO GUSTY WINDS AND LOCALLY CHOPPIER CONDITIONS EACH DAY ALONG WITH REDUCED VISIBILITIES. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 76 91 76 90 / 40 60 30 40 FORT LAUDERDALE 78 91 78 92 / 40 50 20 40 MIAMI 78 92 78 91 / 40 50 20 40 NAPLES 77 90 77 90 / 60 50 20 40 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ SHORT TERM...13/SI LONG TERM....21/KM
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
848 PM EDT MON AUG 4 2014 ...WARMER AND SLIGHTLY DRIER ACROSS NE FL/SE GA ON TUESDAY... .UPDATE... WEAK LOW/TROF JUST EAST OF THE NE FL COAST WILL SLOWLY WORK ITS WAY E/NE TONIGHT AND WILL BE OFFSHORE THE CAROLINAS BY LATER ON TUESDAY. THIS WILL BACK THE CURRENT NORTHEAST STEERING FLOW TO THE NORTHWEST ON TUESDAY AND WILL SLOWLY PULL DOWN A DRIER AIRMASS INTO SE GA AND NORTH FL ALONG THE I-10 CORRIDOR. TONIGHT...COASTAL SHOWER ACTIVITY FROM JAX NORTHWARD WILL SPIN DOWN AND LINGER OVER THE COASTAL WATERS. AS SURFACE FLOW BECOMES NORTHWEST AND INCREASES SLIGHTLY TOWARDS MORNING AROUND 5 MPH...NOT EXPECTING MUCH IN THE WAY OF FOG FORMATION ALTHOUGH SOME LOWER STRATUS CLOUDS COULD DEVELOP TOWARDS MORNING. LOWS GENERALLY CLOSER TO CLIMO VALUES IN THE LOWER/MIDDLE 70S. ON TUESDAY...RETURN TO NORTHWEST FLOW AND MUCH MORE INSOLATION WILL PUSH MAX TEMPS CLOSER TO CLIMO VALUES IN THE LOWER 90S ALTHOUGH MIDDLE 90S WILL BE POSSIBLE CLOSER TO THE DRIER AIRMASS ACROSS INLD SE GA/SUWANNEE RIVER VALLEY WHERE RAIN CHANCES WILL BE GENERALLY LESS THAN 20 PERCENT. ELSEWHERE ACROSS INLD NE FL WHERE LINGERING MOISTURE VALUES WILL BE HIGHEST EXPECTING SCATTERED SHOWERS AND STORMS TO DEVELOP DURING THE AFTERNOON HOURS AND TRACK OFF TOWARDS THE E/SE AND A FEW MAY CONTAIN GUSTY WINDS/FREQUENT LIGHTNING BUT NOT EXPECTING SEVERE WEATHER. && .AVIATION... CONDITIONS WILL FAVOR VFR AT MOST TIMES THIS EVENING...BUT A FEW BRIEF PERIODS OF MVFR CEILINGS WILL BE POSSIBLE...ESPECIALLY AT SSI. THE NAM AND HRRR ARE MOST AGGRESSIVE WITH IFR STRATUS CEILINGS DEVELOPING NEAR THE COAST LATER TONIGHT. HAVE PLACED IN SOME TEMPO GROUPS FOR SCT008 TO SHOW THE POTENTIAL FOR SOME LOW CEILINGS TONIGHT BUT CONFIDENCE IS NOT QUITE HIGH ENOUGH TO FORECAST IFR CEILINGS JUST YET. && .MARINE... WEAK LOW/TROF JUST EAST OF JACKSONVILLE WILL SLOWLY PULL AWAY TO THE EAST/NORTHEAST OVER THE NEXT 24 HOURS. THIS WILL ALLOW FOR ONSHORE FLOW TO BECOME NORTHWEST AFTER MIDNIGHT AND INCREASE TO AROUND 15 KNOTS TOWARDS MORNING...THEN WEAKEN LATE TUESDAY AFTERNOON ENOUGH TO ALLOW FOR LOCAL SEA BREEZE TO DEVELOP LATE. COMBINED SEAS WILL GENERALLY REMAIN IN THE 4-6 FT RANGE TONIGHT ALTHOUGH WIND WAVE PORTION WILL LESSEN WITH TIME AND WILL REMAIN ELEVATED ON TUESDAY DUE TO SOME SWELL PUSHING INTO THE WATERS FROM BERTHA. RIP CURRENTS: MODERATE RISK WILL CONTINUE ON TUESDAY AS SOME OF THE LONGER PERIOD SWELLS FROM BERTHA IMPACT THE COAST. BREAKER REPORTS CONTINUE IN THE 3-5 FT RANGE. && .PRELIMINARY POINT TEMPS/POPS... AMG 70 94 73 95 / 30 10 20 20 SSI 75 89 76 92 / 50 20 20 30 JAX 71 92 74 94 / 30 20 20 30 SGJ 74 90 75 92 / 30 30 20 30 GNV 71 92 72 93 / 10 40 30 40 OCF 73 93 73 93 / 30 50 30 40 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. AM...NONE. && $$ HESS/SHULER/WALKER
AREA FORECAST DISCUSSION
NWS MIAMI FL
252 PM EDT SUN AUG 3 2014 .NEAR TERM...(THIS AFTERNOON) THE HEAVY LINE OF SHOWERS/TSTMS THAT MOVED ASHORE EARLY THIS AFTERNOON HAS WEAKENED AND DISSIPATED...MAINLY DUE TO THE MORE STABLE EAST COAST WHERE TEMPERATURES HAVE REMAINED STEADY IN THE LOWER 80S FROM THE EXTENSIVE CLOUD COVERAGE ASSOCIATED WITH THE OFFSHORE CONVECTION EARLIER. FARTHER INLAND...ADDITIONAL SHOWERS HAVE BEGUN TO DEVELOP WHERE A BETTER SOURCE OF INSTABILITY EXISTS (TEMPERATURES HAVE ALREADY REACHED THE UPPER 80S TO 90 DEG RANGE). THE LATEST HRRR HAS PICKED UP ON THESE TRENDS AND HAS BACKED OFF ON THE EARLIER SUGGESTED EAST COAST ACTIVITY LATER THIS AFTERNOON/EARLY EVENING SHOWING MOSTLY STRATIFIED PRECIP FOR THE SE FL COAST (OR LIGHT RAIN WITH EMBEDDED HEAVIER SHOWERS/TSTMS ALONG THE EAST COAST) THROUGH THE AFTERNOON HOURS. HOWEVER...THE LAKE REGION INCLUDING PALM BEACH COUNTY COULD OBSERVE SOME HEAVIER AFTERNOON SHOWERS/TSTMS. .SHORT TERM...(TONIGHT-TUESDAY NIGHT) THE LATEST SHORT-RANGE MODEL GUIDANCE REMAINS CONSISTENT FROM CYCLE TO CYCLE AND INDICATES THE WET PATTERN PERSISTING INTO THE UPCOMING WEEK AS A SURFACE TROUGH OF LOW PRESSURE AND UPPER TROUGH CONTINUE TO INFLUENCE THE LOCAL WEATHER PATTERN. AN ASCAT PASS THIS AFTERNOON SHOWED TS BERTHA CENTERED NEAR THE SOUTHEASTERN BAHAMA ISLANDS. THE LATEST ADVISORY INDICATES BERTHA TURNING NORTHWARD AND REMAINING JUST EAST OF THE BAHAMAS THROUGH MONDAY AS IT PASSES (SHOULD NOT HAVE ANY DIRECT IMPACT ON THE LOCAL AREA). THE LATEST GUIDANCE INDICATES THE SFC TROUGH OVERHEAD THAT IS IMPACTING THE LOCAL WEATHER SLOWLY LIFTING NWD INTO MONDAY...WHICH WILL TRANSLATE TO SW LOW-LEVEL FLOW WITH THE RIDGE AXIS ORIENTED E-W SOUTH OF THE AREA OVER THE STRAITS. THIS LOW-LEVEL FLOW COMBINED WITH THE AFOREMENTIONED DEEP LAYER MOISTURE (MODEL PWAT VALUES RANGING FROM 2- 2.3" MONDAY-TUESDAY EVENING) COULD TRANSLATE TO A POTENTIAL HEAVY RAINFALL/FLOODING CONCERN OVER PORTIONS OF THE LOCAL AREA PERIODICALLY...ESPECIALLY WITH THE RECENT ACTIVITY AND THE ALREADY SATURATED GROUNDS. THE LATEST RAINFALL ACCUMULATION PROJECTION INDICATES 1.5 TO 2.5" WIDESPREAD AMOUNTS. MUCH HIGHER LOCALIZED AMOUNTS WHERE ANY ACTIVITY BECOMES FOCUSED FOR A PERIOD OF TIME WILL REMAIN POSSIBLE EACH DAY. THE SURFACE FLOW IS PROJECTED TO REMAIN LIGHT ENOUGH FOR AN EAST COAST SEA BREEZE TO DEVELOP EACH DAY...WHICH TYPICALLY RESULTS IN THE AFTERNOON CONVECTION SETTING UP AND FAVORING THE EAST COAST. HOWEVER...SIMILAR TO TODAY...STABILITY COULD PLAY A ROLE HERE AND END UP REDUCING THE OVERALL HEAVY RAIN/FLOODING CONCERNS...IF THE OVERCAST AND RELATIVELY COOL CONDITIONS ARE REALIZED THROUGH THE AFTERNOON PERIODS AGAIN MONDAY AND TUESDAY. .LONG TERM (WEDNESDAY-WEEKEND)... THE LATEST EXTENDED GUIDANCE CONTINUES TO SUGGEST A RETURN OF A MORE TYPICAL SUMMER-LIKE PATTERN ACROSS THE REGION THROUGH THE SECOND HALF OF THE WEEK AND INTO THE WEEKEND AS A DEEP LAYER RIDGE BUILDS BACK OVERHEAD. AT THIS TIME...IT APPEARS WEDNESDAY COULD BE THE TRANSITION DAY...WHICH WOULD MEAN ANOTHER WET AFTERNOON WITH A SUFFICIENT AMOUNT OF DEEP LAYER MOISTURE AND LIGHT SW LOW-LEVEL FLOW TO FOCUS THE AFTERNOON ACTIVITY TOWARD THE EAST COAST. && .AVIATION... MOST OF THE CONVECTION HAS DISSIPATED ACROSS THE NEAR SHORE ATLANTIC WATERS THIS AFTERNOON AFTER ENCOUNTERING A MORE STABLE AIR MASS. ONLY AREAS OF LIGHT TO MODERATE SHOWERS REMAIN WHICH SHOULD BE COVERED WELL WITH VCSH. LATEST HRRR KEEPS SHOWERS ACROSS THE EAST COAST THROUGH THE EARLY EVENING WITH CONTINUED SOUTHEAST TO SOUTHERLY WINDS. ANY REMAINING CONVECTION SHOULD STAY ACROSS THE INTERIOR POSSIBLY AFFECTING KAPF. LEFT VCTS MENTION THERE UNTIL 01Z. && .MARINE... TROPICAL STORM BERTHA IS FORECAST TO REMAIN WELL EAST OF THE SOUTH FLORIDA MARINE AREAS AS IT TURNS NORTH EAST OF THE BAHAMAS LATE TONIGHT THROUGH MONDAY. WINDS ARE FORECAST TO REMAIN LIGHT AND SHIFT TO THE SOUTHWEST THROUGH THE EARLY PORTION OF THE WEEK. SCATTERED SHOWERS AND STORMS COULD LEAD TO GUSTY WINDS AND LOCALLY CHOPPIER CONDITIONS EACH DAY ALONG WITH REDUCED VISIBILITIES. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 76 90 77 92 / 50 70 40 60 FORT LAUDERDALE 77 90 80 92 / 50 70 40 50 MIAMI 77 90 79 91 / 50 70 40 50 NAPLES 77 90 76 91 / 30 50 60 50 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ AVIATION...10/CD REST OF DISCUSSION....85/AG
AREA FORECAST DISCUSSION
NWS MIAMI FL
955 AM EDT SUN AUG 3 2014 .UPDATE... THE LATEST FORECAST PACKAGE HAS BEEN UPDATED TO REFLECT THE LATEST OBSERVATIONS AND TRENDS AROUND THE AREA THIS MORNING AND TO INCREASE THE RAINFALL CHANCES FOR TODAY THROUGH MONDAY. THE MORNING SURFACE ANALYSIS SHOWED A TROUGH OF LOW PRESSURE EXTENDING NORTHWARD ACROSS THE AREA AND NUMEROUS SHOWERS AND STORMS DEVELOPING ALONG A CONVERGENT BOUNDARY OFF OF THE SE FLORIDA COAST ACROSS THE ATLANTIC WATERS. THE LATEST HRRR CYCLE SHOWED THIS COASTAL ACTIVITY SHIFTING WESTWARD THIS AFTERNOON THROUGH THE EARLY EVENING PERIOD, ESPECIALLY ALONG THE EAST COAST AS THE TROUGH SHIFTS WEST AND THE LOW-LEVEL FLOW VEERS TO THE SW. PROVIDED THE EXTENSIVE CLOUD COVERAGE ALONG THE EAST COAST...IT MAY TAKE LONGER INTO THE AFTERNOON BEFORE THE EAST COAST SEA BREEZE DEVELOPS. THIS COULD DELAY THIS COASTAL ACTIVITY FROM SHIFTING WESTWARD WELL INTO THE EARLY AFTERNOON HOURS. IF THE HRRR ENDS UP VERIFYING, LOCALIZED FLOODING CAN`T BE RULED OUT LATER TODAY OVER THE EAST COAST AND METRO AREAS CONSIDERING THE RECENT ACTIVITY AND THE SATURATED GROUNDS. 85/AG && .PREV DISCUSSION... /ISSUED 813 AM EDT SUN AUG 3 2014/ AVIATION... AN AREA OF LOW PRESSURE ACROSS THE BAHAMAS CONTINUES TO SPREAD DEEP MOISTURE ACROSS THE ATLANTIC WATERS AND INTO SOUTH FLORIDA. THIS WILL RESULT IN NUMEROUS SHOWERS AND A FEW THUNDERSTORMS AFFECTING THE EAST COAST SITES THROUGH THE DAY. PREVAILING WIND DIRECTION WILL BE A CHALLENGE AS IT WILL BE DEPENDENT ON THE EXACT TRACK OF THE LOW AS IT PROGRESSES NORTHWARD. FOR NOW...PREVAILED MAINLY SOUTHEAST WINDS THROUGH THE AFTERNOON FROM KFLL NORTHWARD WITH MORE SOUTHWESTERLY FROM KOPF SOUTHWARD. CONFIDENCE IS LOW HOWEVER AS MODELS DIFFER ON THE EXACT TRACK OF THE LOW. PREV DISCUSSION... /ISSUED 415 AM EDT SUN AUG 3 2014/ DISCUSSION... DEEP MOISTURE HAS ARRIVED WITH 2"+ PWATS IN PLACE ACROSS SOUTH FLORIDA ASSOCIATED WITH AN AREA OF LOW PRESSURE WHICH HAS BEEN MOVING OUR WAY FROM THE BAHAMAS. FOR SEVERAL RUNS...MODELS HAVE BEEN ADVERTISING NUMEROUS THUNDERSTORMS UNDERNEATH THIS SURFACE LOW TODAY. MAY NEED TO BE WARY OF VERY SLOW MOVING STORMS AND STORM COLLISIONS/MERGERS DUE TO LIGHT WINDS...LEADING TO POSSIBLE WATER PROBLEMS OVER THE NEXT FEW DAYS. HRRR AND HI RES MODELS INDICATE STORMS FIRST EITHER MOVE ONSHORE OR DEVELOP ALONG THE ATLANTIC COAST...THEN CRAWL TO THE INTERIOR LATE DAY. THE WEAK LOW THEN MOVES NORTH SUNDAY NIGHT AND MERGES WITH THE STATIONARY BOUNDARY WHICH HAS BEEN DRAPED THROUGH THE SOUTHEAST FOR SEVERAL DAYS. MODEL SOUNDINGS INDICATE THAT THE 2"+ PWATS REMAIN THROUGH TUESDAY...ALTHOUGH THIS MAY BE SLIGHTLY OVERDONE CONSIDERING THE MEAN RH IN SOME OF THE MODEL MASS FIELDS WHICH SHOWS A BIT OF A DRYING TREND. SURFACE WINDS WILL BECOME SW TO W MONDAY AND TUESDAY WITH THE SURFACE LOW ACROSS NORTH FLORIDA. A MORNING GULF COAST IS EXPECTED WITH FOCUS THEN SHIFTING TO THE INTERIOR AND ATLANTIC COAST LATER IN THE DAY. ALTHOUGH THE STATIONARY BOUNDARY WILL WASH OUT ACROSS THE SOUTHEAST...A SUBTLE WEAKNESS/TROUGH WILL REMAIN ALONG THE EAST COAST INTO THE MIDDLE OF NEXT WEEK. THIS WILL DELAY THE ARRIVAL OF UPPER RIDGING/RISING HEIGHTS/SUBSIDENCE ACROSS SOUTH FLORIDA UNTIL LATE NEXT WORK WEEK OR NEXT WEEKEND. THUS...WEDNESDAY MAY BE A WETTER DAY THAN PREVIOUS FORECASTS HAVE SUGGESTED. MARINE... TROPICAL STORM BERTHA IS FORECAST TO REMAIN WELL EAST OF THE SOUTH FLORIDA MARINE AREAS AS IT TURNS NORTH EAST OF THE BAHAMAS LATE SUNDAY NIGHT THROUGH MONDAY. WINDS ARE FORECAST TO SHIFT TO THE SOUTHWEST THROUGH THE EARLY PORTION OF THE WEEK FROM 5 KTS TO 15 KTS...THEN BECOMING VARIABLE AROUND 5 KTS BY THE END OF THE WEEK. SCATTERED SHOWERS AND STORMS COULD LEAD TO GUSTY WINDS AND LOCALLY CHOPPIER CONDITIONS EACH DAY. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 91 79 90 77 / 80 30 70 30 FORT LAUDERDALE 90 79 91 80 / 80 30 70 40 MIAMI 90 78 90 79 / 80 30 70 40 NAPLES 92 77 88 77 / 60 30 50 60 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ SHORT TERM...84/AK LONG TERM....21/KM
AREA FORECAST DISCUSSION
NWS MIAMI FL
813 AM EDT SUN AUG 3 2014 .AVIATION... AN AREA OF LOW PRESSURE ACROSS THE BAHAMAS CONTINUES TO SPREAD DEEP MOISTURE ACROSS THE ATLANTIC WATERS AND INTO SOUTH FLORIDA. THIS WILL RESULT IN NUMEROUS SHOWERS AND A FEW THUNDERSTORMS AFFECTING THE EAST COAST SITES THROUGH THE DAY. PREVAILING WIND DIRECTION WILL BE A CHALLENGE AS IT WILL BE DEPENDENT ON THE EXACT TRACK OF THE LOW AS IT PROGRESSES NORTHWARD. FOR NOW...PREVAILED MAINLY SOUTHEAST WINDS THROUGH THE AFTERNOON FROM KFLL NORTHWARD WITH MORE SOUTHWESTERLY FROM KOPF SOUTHWARD. CONFIDENCE IS LOW HOWEVER AS MODELS DIFFER ON THE EXACT TRACK OF THE LOW. && .PREV DISCUSSION... /ISSUED 415 AM EDT SUN AUG 3 2014/ DISCUSSION... DEEP MOISTURE HAS ARRIVED WITH 2"+ PWATS IN PLACE ACROSS SOUTH FLORIDA ASSOCIATED WITH AN AREA OF LOW PRESSURE WHICH HAS BEEN MOVING OUR WAY FROM THE BAHAMAS. FOR SEVERAL RUNS...MODELS HAVE BEEN ADVERTISING NUMEROUS THUNDERSTORMS UNDERNEATH THIS SURFACE LOW TODAY. MAY NEED TO BE WARY OF VERY SLOW MOVING STORMS AND STORM COLLISIONS/MERGERS DUE TO LIGHT WINDS...LEADING TO POSSIBLE WATER PROBLEMS OVER THE NEXT FEW DAYS. HRRR AND HI RES MODELS INDICATE STORMS FIRST EITHER MOVE ONSHORE OR DEVELOP ALONG THE ATLANTIC COAST...THEN CRAWL TO THE INTERIOR LATE DAY. THE WEAK LOW THEN MOVES NORTH SUNDAY NIGHT AND MERGES WITH THE STATIONARY BOUNDARY WHICH HAS BEEN DRAPED THROUGH THE SOUTHEAST FOR SEVERAL DAYS. MODEL SOUNDINGS INDICATE THAT THE 2"+ PWATS REMAIN THROUGH TUESDAY...ALTHOUGH THIS MAY BE SLIGHTLY OVERDONE CONSIDERING THE MEAN RH IN SOME OF THE MODEL MASS FIELDS WHICH SHOWS A BIT OF A DRYING TREND. SURFACE WINDS WILL BECOME SW TO W MONDAY AND TUESDAY WITH THE SURFACE LOW ACROSS NORTH FLORIDA. A MORNING GULF COAST IS EXPECTED WITH FOCUS THEN SHIFTING TO THE INTERIOR AND ATLANTIC COAST LATER IN THE DAY. ALTHOUGH THE STATIONARY BOUNDARY WILL WASH OUT ACROSS THE SOUTHEAST...A SUBTLE WEAKNESS/TROUGH WILL REMAIN ALONG THE EAST COAST INTO THE MIDDLE OF NEXT WEEK. THIS WILL DELAY THE ARRIVAL OF UPPER RIDGING/RISING HEIGHTS/SUBSIDENCE ACROSS SOUTH FLORIDA UNTIL LATE NEXT WORK WEEK OR NEXT WEEKEND. THUS...WEDNESDAY MAY BE A WETTER DAY THAN PREVIOUS FORECASTS HAVE SUGGESTED. MARINE... TROPICAL STORM BERTHA IS FORECAST TO REMAIN WELL EAST OF THE SOUTH FLORIDA MARINE AREAS AS IT TURNS NORTH EAST OF THE BAHAMAS LATE SUNDAY NIGHT THROUGH MONDAY. WINDS ARE FORECAST TO SHIFT TO THE SOUTHWEST THROUGH THE EARLY PORTION OF THE WEEK FROM 5 KTS TO 15 KTS...THEN BECOMING VARIABLE AROUND 5 KTS BY THE END OF THE WEEK. SCATTERED SHOWERS AND STORMS COULD LEAD TO GUSTY WINDS AND LOCALLY CHOPPIER CONDITIONS EACH DAY. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 91 79 90 77 / 70 30 40 30 FORT LAUDERDALE 90 79 91 80 / 70 30 40 40 MIAMI 90 78 90 79 / 70 30 40 40 NAPLES 92 77 88 77 / 60 30 60 60 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
440 AM EDT SUN AUG 3 2014 .SYNOPSIS... 08Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A SIMILAR LONGWAVE PATTERN TO 24 HOURS AGO...WITH RIDGING ACROSS THE WESTERN HALF OF THE CONUS AND PERSISTENT TROUGHING OVER MUCH OF THE EAST. UPPER LEVEL PATTERN OVER THE FLORIDA PENINSULA IS RATHER UNDEFINED EARLY THIS MORNING BETWEEN THE MAIN LONGWAVE TROUGH TO OUR NORTH...AND A WEAK IMPULSE APPROACHING FROM OVER THE BAHAMAS. THE OVERALL ATMOSPHERE IS QUITE MOIST REGION WIDE AHEAD OF THIS IMPULSE WITH PW VALUES HOLDING IN THE VICINITY OF 2". THE SURFACE REFLECTION OF THIS APPROACHING IMPULSE IS SEEN AS A WEAK INVERTED TROUGH ACROSS SOUTH FLORIDA AND THE FL STRAITS...AND IS PROGGED BY JUST ABOUT ALL NWP GUIDANCE MEMBERS TO CLOSE OFF INTO A WEAK SURFACE LOW OVER THE PENINSULA TODAY AND THEN DRIFT NORTHWARD THROUGH TONIGHT. REGIONAL RADARS A FAIRLY QUIET THIS EARLY MORNING WITH JUST A FEW SHOWERS OVER THE COASTAL WATERS OF THE EASTERN GULF OF MEXICO...AND A SCATTERING OF SHOWERS MOVING ONSHORE THE FLORIDA EAST COAST. THESE SHOWERS WILL HAVE A HARD TIME REACHING OUR FORECAST AREA THE NEXT SEVERAL HOURS AS THEY TEND TO DISSIPATE WITH INLAND PENETRATION. CAN NOT RULE OUT A BRIEF SPRINKLE IN FAR EASTERN POLK/HIGHLANDS COUNTIES EARLY THIS MORNING...BUT THAT SHOULD BE JUST ABOUT IT. && .SHORT TERM (TODAY THROUGH MONDAY)... TODAY... UNFORTUNATELY THE SYNOPTIC PATTERN IS NOT ONE THAT SUPPORTS A VERY SPATIALLY OR TEMPORALLY DETAILED FORECAST PACKAGE. THE ATMOSPHERE IS PRETTY FAVORABLE FOR DEEP CONVECTION WITH THE DEEP MOISTURE...AND LITTLE TO NO DRY AIR LAYERS FOR THE CONVECTIVE UPDRAFTS TO FIGHT. IN ADDITION...THE WEAK LOW FEATURE TRAVERSING THE AREA TODAY WILL ADD A BROAD LOW LEVEL FOCUS FOR ASCENT AND INTERACT WITH DEVELOPING SEA-BREEZE BOUNDARIES TO GIVE US ANOTHER FAIRLY ACTIVE SECOND HALF OF THE DAY IN TERMS OF CONVECTION. DO FEEL...MUCH OF THE MORNING WILL BE ON THE QUIET SIDE...HOWEVER ONCE WE GET SOME DECENT SURFACE HEATING...IT WILL NOT TAKE MUCH TO GET THE STORMS BUBBLING UP. AS MENTIONED ABOVE...THE BROAD LOW LEVEL FOCUS FOR ASCENT ACROSS THE REGION MAKES IT DIFFICULT TO GET VERY DETAILED WITH THE TIMING OF STORMS FOR ANY ONE LOCATION. THE BEST RAIN CHANCES (> 60%) DO APPEAR TO BE ALONG AND EAST OF THE I-75 CORRIDOR AS THE SEA-BREEZE SHOULD BE ABLE TO MAKE SOME PROGRESS INLAND. THEREFORE...THE BEST CHANCES FOR A DRY AFTERNOON WOULD BE CLOSE TO THE COAST FROM MANATEE COUNTY NORTHWARD. THE FORECAST UNCERTAINLY STILL SUGGESTS KEEPING A CHANCE POP FOR THESE COASTAL AREAS AS WELL...AND THE DAY SHIFT CAN SEE HOW THINGS ARE EVOLVING LATER THIS MORNING AND MAKE ANY NECESSARY ADJUSTMENTS. SIMILAR TO SATURDAY...STORMS THAT DO DEVELOP WILL BE SLOW MOVERS...AND COMBINED WITH THE MOIST ATMOSPHERE WILL BE CAPABLE OF SOME LOCALLY HEFTY RAINFALL TOTALS. WILL HAVE TO WATCH CLOSELY AREAS THAT SAW SIGNIFICANT RAINFALL ON SATURDAY AND MAY NOT BE ABLE TO HANDLE THE RUNOFF AS WELL IN CASE THESE SAME AREA FIND THEMSELVES UNDER SLOW MOVING STORMS ONCE AGAIN. MONDAY... STARTING OUT THE WORK WEEK...WE WILL FIND THE WEAK LOW PRESSURE AREA BEGINNING TO LIFT NORTHWARD ALONG THE GA/CAROLINA COAST. IN THE WAKE OF THIS SYSTEM...LOW LEVEL WINDS WILL COME AROUND TO A MORE UNIFORM WESTERLY DIRECTION. THE WEST WIND AND MOIST PROFILE SUGGEST A CHANCE FOR SOME EARLY MORNING SHOWERS DEVELOPING OVER THE COASTAL WATERS AND MOVING TOWARD SHORE. A WESTERLY FLOW PATTERN IN TERMS OF CLIMO WOULD SHIFT THE BETTER RAIN CHANCES INLAND FOR THE AFTERNOON IN A MORE DEFINED MANNER. WILL FOLLOW THIS APPROACH FOR THE FORECAST GRIDS AND SHOW SHOWERS SHIFTING INLAND FROM THE COAST DURING THE LATER MORNING AND EARLY AFTERNOON HOURS AND THEN BECOMING MORE NUMEROUS EAST OF THE I-75 CORRIDOR. A RETURN TO A MORE TYPICAL EARLY AUGUST PATTERN WILL ARRIVE FOR TUESDAY INTO THE MIDDLE OF THE WEEK. READ MORE ABOUT THIS PATTERN CHANGE IN THE LONG TERM DISCUSSION BELOW. ENJOY THE SECOND HALF OF YOUR WEEKEND! && .LONG TERM (TUESDAY THROUGH NEXT SATURDAY)... THROUGH WED...AN UPPER TROUGH RESIDES ACROSS THE EASTERN CONUS WHILE AN UPPER RIDGE EXTENDS FROM THE ATLANTIC ACROSS CUBA TO THE CARRIBEAN SEA. AT THE SURFACE A TROUGH ACROSS SOUTH GA/NORTH FL AND THE COASTAL WATERS LIFTS NORTHWARD ALONG THE EASTERN SEABOARD WHILE THE NATIONAL HURRICANE CENTER MOVES BERTHA FROM EAST OF THE BAHAMAS TO WELL SOUTHEAST OF NEW ENGLAND. A SURFACE RIDGE FROM THE ATLANTIC ACROSS THE BAHAMAS TO THE SOUTHERN GULF TRACKS INTO SOUTH FL. THE AREA CONTINUES IN A MOIST AND UNSTABLE AIRMASS WITH ISOLATED TO HIGH END...50 POP...SCATTERED SHOWERS AND THUNDERSTORMS. TEMPERATURES WILL RUN CLOSE TO NORMAL. THE SURFACE PRESSURE FIELD WILL BE RELAXED WITH LIGHT WESTERLY FLOW ENHANCED BY AFTERNOON SEA BREEZES. FOR THU INTO SAT...THE EASTERN U.S. UPPER TROUGH LIFTS UP NORTHEASTWARD AS IT SLIDES OUT OVER THE ATLANTIC WHILE THE CUBAN RIDGE MOVES TO THE GULF AND FL. IN RESPONSE THE SURFACE RIDGE MOVES INTO CENTRAL FL WITH THE LOW LEVEL FLOW GRADUALLY BECOMING MORE SOUTHEASTERLY SOUTH OF THE RIDGE AXIS...BUT WITH A GRADIENT LIGHT ENOUGH TO ALLOW AFTERNOON SEA BREEZES. NORTH OF THE THE AXIS THE FLOW WILL BE SW TO WEST. THE ATMOSPHERE DRIES AND WARMS SLIGHTLY. BUT STILL EXPECT SHOWERS AND STORMS IN THE LOW TO MID...30 TO 40 POPS...SCATTERED RANGE. TEMPERATURES WILL BE JUST ABOVE NORMAL. && .AVIATION... VFR CONDITIONS PREVAIL ACROSS THE REGION EARLY THIS MORNING. LARGE SWATH OF BKN-OVC HIGH LEVEL CIRRUS WILL SLOWLY SCATTER OUT THROUGH SUNRISE TO THE SOUTH OF THE I-4 CORRIDOR. GENERAL VFR CONDITIONS WILL REMAIN COMMON THROUGH THE DAY ON SUNDAY...HOWEVER SCATTERED TO NUMEROUS SHOWERS AND STORMS WILL INITIATE DURING THE AFTERNOON. BEST CHANCES TO SEE A STORM AND ASSOCIATED RESTRICTIONS WILL BE AT KFMY/KRSW/KPGD AND KLAL. THE TERMINALS AROUND THE TAMPA BAY AREA MAY STILL SEE A STORM...HOWEVER STORM COVERAGE SHOULD BE LESS INSIDE THE I-75 CORRIDOR. && .MARINE... A WEAK AREA OF LOW PRESSURE WILL TRACK NORTHWARD TODAY AND TONIGHT OVER THE FLORIDA PENINSULA BEFORE EXITING TO THE NORTHEAST DURING MONDAY AND TUESDAY. IN THE WAKE OF THIS LOW HIGH PRESSURE WILL AGAIN TAKE UP POSITION OVER THE CENTRAL AND EASTERN GULF OF MEXICO. WINDS AND SEAS WILL BE LOW THE NEXT SEVERAL DAYS ALTHOUGH WIND DIRECTION MAY BE A BIT ERRATIC THROUGH TONIGHT AS THE WEAK LOW MOVES NORTHWARD THROUGH THE REGION. && .FIRE WEATHER... A MOIST LOW LEVEL ENVIRONMENT WILL KEEP RELATIVE HUMIDITY LEVELS WELL ABOVE CRITICAL LEVELS THE NEXT SEVERAL DAYS. RAIN CHANCES WILL REMAIN HIGH THROUGH MONDAY AND THEN SHOWERS AND STORM COVERAGE SHOULD RETURN TO MORE NORMAL LEVELS FOR EARLY AUGUST BY THE MIDDLE PORTION OF THE WEEK. FOG POTENTIAL...SOME SHALLOW GROUND FOG MAY FORM OVER INLAND LOCATIONS DURING THE EARLY MORNING HOURS THE NEXT FEW DAYS BUT NO SIGNIFICANT VISIBILITY RESTRICTIONS ARE EXPECTED. && .PRELIMINARY POINT TEMPS/POPS... TPA 91 77 91 78 / 50 40 40 40 FMY 92 77 91 76 / 70 40 50 40 GIF 93 77 92 76 / 60 40 60 30 SRQ 91 78 90 77 / 40 40 40 40 BKV 93 73 92 73 / 50 40 40 30 SPG 91 80 91 80 / 40 40 40 40 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ SYNOPSIS/SHORT TERM/MARINE/AVIATION/FIRE WX...MROCZKA LONG TERM...RUDE
AREA FORECAST DISCUSSION
NWS MIAMI FL
415 AM EDT SUN AUG 3 2014 .DISCUSSION... DEEP MOISTURE HAS ARRIVED WITH 2"+ PWATS IN PLACE ACROSS SOUTH FLORIDA ASSOCIATED WITH AN AREA OF LOW PRESSURE WHICH HAS BEEN MOVING OUR WAY FROM THE BAHAMAS. FOR SEVERAL RUNS...MODELS HAVE BEEN ADVERTISING NUMEROUS THUNDERSTORMS UNDERNEATH THIS SURFACE LOW TODAY. MAY NEED TO BE WARY OF VERY SLOW MOVING STORMS AND STORM COLLISIONS/MERGERS DUE TO LIGHT WINDS...LEADING TO POSSIBLE WATER PROBLEMS OVER THE NEXT FEW DAYS. HRRR AND HI RES MODELS INDICATE STORMS FIRST EITHER MOVE ONSHORE OR DEVELOP ALONG THE ATLANTIC COAST...THEN CRAWL TO THE INTERIOR LATE DAY. THE WEAK LOW THEN MOVES NORTH SUNDAY NIGHT AND MERGES WITH THE STATIONARY BOUNDARY WHICH HAS BEEN DRAPED THROUGH THE SOUTHEAST FOR SEVERAL DAYS. MODEL SOUNDINGS INDICATE THAT THE 2"+ PWATS REMAIN THROUGH TUESDAY...ALTHOUGH THIS MAY BE SLIGHTLY OVERDONE CONSIDERING THE MEAN RH IN SOME OF THE MODEL MASS FIELDS WHICH SHOWS A BIT OF A DRYING TREND. SURFACE WINDS WILL BECOME SW TO W MONDAY AND TUESDAY WITH THE SURFACE LOW ACROSS NORTH FLORIDA. A MORNING GULF COAST IS EXPECTED WITH FOCUS THEN SHIFTING TO THE INTERIOR AND ATLANTIC COAST LATER IN THE DAY. ALTHOUGH THE STATIONARY BOUNDARY WILL WASH OUT ACROSS THE SOUTHEAST...A SUBTLE WEAKNESS/TROUGH WILL REMAIN ALONG THE EAST COAST INTO THE MIDDLE OF NEXT WEEK. THIS WILL DELAY THE ARRIVAL OF UPPER RIDGING/RISING HEIGHTS/SUBSIDENCE ACROSS SOUTH FLORIDA UNTIL LATE NEXT WORK WEEK OR NEXT WEEKEND. THUS...WEDNESDAY MAY BE A WETTER DAY THAN PREVIOUS FORECASTS HAVE SUGGESTED. && .MARINE... TROPICAL STORM BERTHA IS FORECAST TO REMAIN WELL EAST OF THE SOUTH FLORIDA MARINE AREAS AS IT TURNS NORTH EAST OF THE BAHAMAS LATE SUNDAY NIGHT THROUGH MONDAY. WINDS ARE FORECAST TO SHIFT TO THE SOUTHWEST THROUGH THE EARLY PORTION OF THE WEEK FROM 5 KTS TO 15 KTS...THEN BECOMING VARIABLE AROUND 5 KTS BY THE END OF THE WEEK. SCATTERED SHOWERS AND STORMS COULD LEAD TO GUSTY WINDS AND LOCALLY CHOPPIER CONDITIONS EACH DAY. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 89 79 90 77 / 70 30 40 30 FORT LAUDERDALE 88 79 91 80 / 70 30 40 40 MIAMI 88 78 90 79 / 70 30 40 40 NAPLES 90 77 88 77 / 60 30 60 60 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ SHORT TERM...21/KM LONG TERM....21/KM
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1049 PM EDT MON AUG 4 2014 .SYNOPSIS... DRIER AIR WILL ENTER THE REGION FROM THE WEST TUESDAY AND WEDNESDAY PROVIDING WARMER AND DRIER WEATHER. UNSETTLED WEATHER WILL RETURN FOR THE WEEKEND ASSOCIATED WITH A FRONTAL SYSTEM. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... LOW PRESSURE OFF THE SOUTHEAST COAST WILL MOVE NORTH THROUGH TONIGHT. HOWEVER...MUCH OF THE CONVERGENCE ASSOCIATED WITH THE LOW PLUS THE DEEPER MOISTURE SHOULD STAY EAST OF THE FORECAST AREA. SCATTERED SHOWERS THAT MAINLY AFFECTED THE EAST PART OF THE AREA HAVE DISSIPATED WITH THE LOSS OF HEATING. THE LATEST HRRR DOES NOT INDICATE ADDITION SHOWERS OVERNIGHT. LOW-LEVEL MOISTURE AND DIURNAL COOLING SHOULD HELP SUPPORT STRATUS AND FOG DEVELOPMENT. MOST OF THE GFS AND NAM MOS PLUS SREF GUIDANCE INDICATE SOME FOG BUT THE FOG SHOULD BE LIMITED BY SOME CLOUDINESS AND INSTABILITY. THE LATEST HRRR INDICATES LITTLE FOG. WE FORECASTED PATCHY FOG. WE LEANED TOWARD THE WARMER TEMPERATURE GUIDANCE BECAUSE OF CLOUDINESS. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY NIGHT/... THE MAIN UPPER TROUGH AXIS WILL SHIFT THROUGH THE REGION THROUGH THE DAY TUESDAY...FINALLY SHIFTING OFFSHORE BY TUESDAY NIGHT. THE MAIN UPPER FLOW WILL THEN FLATTEN OUT INTO WEDNESDAY...ALTHOUGH WINDS ALOFT WILL STILL BE MORE NORTHWESTERLY. WITH THIS PATTERN THE CHANCE FOR RAIN SHOULD BEGIN TO PUSH OFFSHORE THROUGH THE DAY TUESDAY AS DRIER AIR MOVES INTO THE REGION. THIS WILL LEAVE TUESDAY NIGHT THROUGH WEDNESDAY NIGHT DRY. THE MAIN UPPER PATTERN WILL THEN BEGIN TO SHIFT THURSDAY AS ANOTHER UPPER TROUGH TRIES TO TAKE HOLD ACROSS THE EASTERN UNITED STATES. THIS WILL HELP DRIVE A COLD FRONT TOWARDS THE AREA THURSDAY...WHICH WILL ONCE AGAIN LEAD TO AN INCREASE IN RAIN CHANCES. THE FRONT SHOULD SLOW DOWN AND STALL ACROSS THE FORECAST AREA THURSDAY NIGHT. AS FOR TEMPERATURES...WITH DRIER AIR AND MORE SUNSHINE TUESDAY...WOULD EXPECT THAT THE AFTERNOON HIGHS WILL INCREASE BACK INTO THE UPPER 80S AND LOWER 90S TUESDAY...AND INTO THE LOWER TO MIDDLE 90S WEDNESDAY. WITH AN INCREASE IN CLOUDS AHEAD OF THE FRONT THURSDAY...TEMPERATURES WILL COOL SLIGHTLY...BUT SHOULD STILL REACH THE 90S. && .LONG TERM /FRIDAY THROUGH MONDAY/... THE COLD FRONT THAT WILL STALL ACROSS THE REGION FRIDAY SHOULD LINGER THROUGH THE WEEKEND. THE MAIN UPPER PATTER REMAINS OUT OF THE NORTHWEST. THE UPPER FLOW PATTERN WILL ALIGN WITH THE STALLED FRONT FROM SOUTHERN SC WESTWARD INTO THE SOUTHERN PLAINS STATES. WEATHER SYSTEMS THAT FORM WEST ALONG THIS FRONT MAY BE ABLE TO TRACK EASTWARD AND THROUGH THE SOUTHEASTERN STATES THROUGH THE PERIOD. WOULD EXPECT THAT CHANCE POPS SHOULD CONTINUE THROUGH THE WEEKEND AND INTO THE EARLY PART OF NEXT WEEK DUE TO THE SURFACE BOUNDARY...AND ENERGY ALOFT MOVING ALONG THIS FRONT TOWARDS THE EAST. PWATS BACK UP AROUND 2 INCHES THROUGH THE PERIOD WILL ALLOW FOR A HEAVY RAINFALL POTENTIAL. GFS BEGINS TO SHOW A SURFACE WEDGE FLOW PATTERN EAST OF THE APPALACHIANS BEGINNING SUNDAY INTO MONDAY...WHICH SHOULD BRING TEMPERATURES BACK DOWN INTO THE 80S. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... VFR CONDITIONS TO DOMINATE THE PERIOD...WITH MVFR OR LOWER IN FOG AND STRATUS DURING THE EARLY MORNING HOURS. SHOWERS HAVE DISSIPATED ACROSS THE AREA WITH A FEW LOW CLOUDS REMAINING ALONG WITH SOME MID AND UPPER CLOUDS. MAIN CONCERN OF THE PERIOD REMAINS POTENTIAL FOR EARLY MORNING FOG AND STRATUS. EXPECT FOG TO DEVELOP AT ALL TAF SITES AFTER 08Z...WITH LOWER POTENTIAL FOR STRATUS. LOWEST CONDITIONS WILL BE AT AGS/OGB AROUND SUNRISE AND WILL HANDLE THOSE WITH A TEMPO GROUP IN UPCOMING ISSUANCES. FOG WHICH DEVELOPS WILL QUICKLY DISSIPATE WITH SUNRISE. WINDS THROUGH THE PERIOD WILL BE NORTHERLY AT 5 KNOTS OR LESS. EXTENDED AVIATION OUTLOOK...MVFR OR LOWER CONDITIONS ARE POSSIBLE IN FOG AND STRATUS DURING THE EARLY MORNING HOURS THROUGH THE PERIOD. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
343 AM CDT SUN AUG 3 2014 .DISCUSSION... 338 AM CDT MAIN FORECAST CONCERNS/CHALLENGES ARE WITH RETURNING CHANCES FOR WIDELY SCATTERED SHOWER/THUNDERSTORMS TODAY...AND THEN BETTER CHANCES MONDAY AND MONDAY NIGHT. GENERALLY CLEAR SKIES IN PLACE THIS MORNING AS A MID/UPPER LEVEL RIDGE IS STILL IN PLACE...AND WITH SURFACE HIGH SETTLED OVERHEAD. AS THIS RIDGE SLIDES TO THE SOUTHEAST TODAY...THE SURFACE HIGH WILL LIKEWISE SLOWLY SHIFT EAST WITH A MORE FAVORABLE SETUP FOR WEST/SOUTHWEST WINDS ACROSS THE CWA TODAY. AS HAS BEEN THE CASE FOR THE LAST COUPLE OF DAYS...PLENTY SUNSHINE IN PLACE THIS MORNING WILL HELP TO QUICKLY STEEPENING LOW LEVEL LAPSE RATES WITH GUIDANCE INDICATING A WELL MIXED ENVIRONMENT BY MID/LATE MORNING. INCREASING INSTABILITY WITHIN LOW 60S DEWPOINTS TODAY AS APPROACHING SHORTWAVE ENERGY MOVES OVERHEAD COULD SUPPORT THE DEVELOPMENT OF WIDELY SCATTERED THUNDERSTORMS AS EARLY AS MID DAY. A MORE FAVORED LOCATION FOR THIS DEVELOPMENT WOULD BE ACROSS NORTHERN ILLINOIS WHERE BETTER LARGE SCALE ASCENT WILL RESIDE...ALTHOUGH STILL WEAK. DESPITE THESE MORE FAVORABLE VARIABLES FOR SHOWER/THUNDERSTORM DEVELOPMENT...THERE WILL BE A LACK OF ANY REAL GOOD SURFACE FOCUS TODAY WITH BETTER CHANCES FOR PRECIP APPEARING TO BE ACROSS WISCONSIN. NONETHELESS...AT LEAST ISOLATED BRIEF POP UP SHOWERS/THUNDERSTORMS STILL APPEAR POSSIBLE AS WELL AS ISOLATED DEVELOPMENT ALONG LAKE BREEZE TODAY. SO HAVE MAINTAINED SLIGHT CHANCE/CHANCE POPS THIS AFTERNOON...WITH ONCE AGAIN BETTER CHANCES FURTHER NORTH NEAR THE ILLINOIS/WISCONSIN BORDER. NOT OVERLY CONCERNED WITH ANY STRONGER DEVELOPMENT TODAY...BUT BRIEF HEAVY DOWNPOUR AND GUSTY WINDS STILL CANT BE COMPLETELY RULED OUT. DID INCREASE HIGH TEMPS FOR TODAY AS LOW/MID 80S WITH EVEN SOME MID TO UPPER 80S DEFINITELY A POSSIBILITY TODAY. HAVE BACKED OFF ON POPS TONIGHT AS WHATEVER DEVELOPS THIS AFTERNOON QUICKLY DIMINISHES EARLY THIS EVENING. FOCUS FOR THUNDERSTORM DEVELOPMENT TONIGHT APPEAR TO REMAIN WELL WEST OF THE CWA BACK TOWARDS IOWA AND MISSOURI WHERE INCREASING LLJ AND SURFACE LOW/FRONTAL BOUNDARY WILL RESIDE...WITH A SEPARATE AREA OF BETTER THUNDERSTORM DEVELOPMENT APPEARING TO BE WELL NORTH OVER NORTHERN WISCONSIN ASSOCIATED WITH SOUTHWARD DROPPING COLD FRONT. AS THIS COLD FRONT DROPS FURTHER SOUTH ON MONDAY...SURFACE LOW/TROUGH TO THE WEST WILL BEGIN SHIFTING EAST TOWARDS THE CWA. AS THESE FEATURES DRAW CLOSER TO THE CWA LATER IN THE DAY MONDAY...SHOWER/THUNDERSTORM CHANCES WILL INCREASE ESPECIALLY OVER NORTHERN ILLINOIS. DID INCREASE POPS OVER THIS AREA TO HIGH CHANCE POPS AND BROUGHT AT LEAST A SLIGHT CHANCE FOR THUNDERSTORMS FOR THE REMAINING CWA BY THE AFTERNOON TIME FRAME AS FAVORABLE INSTABILITY IN PLACE WHILE SEVERAL WAVES OF ENERGY MOVE OVERHEAD COULD PROVIDE SOME OUTSIDE SCATTERED DEVELOPMENT. NOT CONCERNED WITH ANY SEVERE THREAT AT THIS TIME...AS BEST THUNDERSTORM DEVELOPMENT SHOULD REMAIN TIED CLOSER TO THE LOW/TROUGH AND BETTER INSTABILITY TO THE WEST DURING MOST OF THE DAY. BEST CHANCES SHOWERS/THUNDERSTORMS DURING THIS PERIOD WILL BE MONDAY NIGHT AS SURFACE LOW/TROUGH AND FRONTAL BOUNDARY PUSH THROUGH. INCREASING MOISTURE COULD SUPPORT HEAVY DOWNPOURS WITH CONFIDENCE REMAINING LOW ON THE STRENGTH OF THIS CONVECTION. WEAK AND UNFAVORABLE DIRECTED LLJ AND LOWER INSTABILITY SHOULD HELP TO LIMIT STRENGTH...BUT COULD STILL SEE AT LEAST SOME ISOLATED STRONGER STORMS STILL DEVELOPING. RODRIGUEZ && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * SMALL CHANCE OF ISOLATED AFTERNOON TSRA. * WIND SHIFT TO EAST POSSIBLE WITH LAKE BREEZE LATE THIS AFTERNOON. RATZER //DISCUSSION...UPDATED 06Z... CALM OR LIGHT/VARIABLE WINDS ARE EXPECTED TO BECOME WEST- SOUTHWEST AFTER SUNRISE THIS MORNING. GRADIENT REMAINS WEAK ENOUGH THAT A LAKE BREEZE WILL LIKELY DEVELOP...THOUGH HOW FAR INLAND IT MOVES IS UNCERTAIN. MOST HIGH-RES GUIDANCE KEEPS THE BOUNDARY EAST OR ORD/MDW THROUGH THE AFTERNOON AND HAVE ELECTED TO KEEP WIND SHIFT OUT OF TAFS AT THIS POINT EXCEPT AT GYY. POTENTIAL FOR ISOLATED TSRA RETURNS TODAY AS UPPER TROUGH MOVES OVER REGION. FORECAST SOUNDINGS DEPICT UNSTABLE THERMODYNAMIC PROFILES WITH LITTLE/NO CAP BY EARLY AFTERNOON. WEAK WINDS AND LACK OF ORGANIZED CONVERGENCE ARE THE ONLY LIMITS TO DEVELOPMENT OF SOME TSRA...AND LAKE BREEZE BOUNDARY COULD FOCUS FOR DEVELOPMENT ESPECIALLY NORTH TOWARD WI WHERE INSTABILITY WILL BE GREATER. HAVE MAINTAINED PROB30 MENTION AT ORD AND ADDED SAME AT RFD WHERE POTENTIAL...WHILE STILL LOW...WILL BE A LITTLE HIGHER THAN AREAS FARTHER SOUTH/SOUTHEAST. IF DEVELOPMENT DOES OCCUR HOWEVER...TSRA WILL LIKELY SPREAD ALONG OUTFLOW BOUNDARIES OR LAKE BREEZE IF IT DEVELOPS. RATZER //ORD AND MDW CONFIDENCE...UPDATED 06Z... * LOW CONFIDENCE IN TSRA COVERAGE THIS AFTERNOON. * LOW CONFIDENCE IN LAKE BREEZE PASSAGE/WIND SHIFT TO EAST THIS AFTERNOON. RATZER //OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z... MONDAY AND TUESDAY...SLIGHT CHANCE OF TSRA BUT MAINLY VFR. WEDNESDAY THROUGH FRIDAY...PREDOMINANTLY VFR. IZZI && .MARINE... 231 AM CDT A PERIOD OF QUIET WEATHER LOOKS TO CONTINUE ACROSS LAKE MICHIGAN THROUGH THE PERIOD...WITH HIGH PRESSURE DOMINATING THE SURFACE PATTERN ACROSS THE WESTERN LAKES REGION. A WEAK LOW MOVING FROM NORTHEASTERN ONTARIO INTO QUEBEC TODAY AND TONIGHT WILL TRAIL A WEAK COLD FRONT ACROSS LAKE MICHIGAN THIS AFTERNOON THROUGH MONDAY. HIGH PRESSURE WILL THEN BUILD IN BEHIND THE FRONT AGAIN TUESDAY...WITH A PERIOD OF NORTHERLY WINDS WHICH MAY STRENGTHEN INTO THE 15-20 KT RANGE FOR A TIME TUESDAY INTO TUESDAY EVENING. THE HIGH WILL THEN TAKE UP RESIDENCE ACROSS THE REGION DURING THE MIDDLE AND END OF THE WEEK WITH LIGHTER WINDS AND DAILY LAKE BREEZES. RATZER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 245 AM CDT Sun Aug 3 2014 .DISCUSSION... ISSUED 245 AM CDT Sun Aug 3 2014 SHORT TERM...Today through Tuesday Another pleasant summer day is on tap across central Illinois today, as 1020mb high centered over the region remains in control of the weather. A short-wave trough currently evident on 07z/2am water vapor imagery over southwest Iowa will track southeastward, but will remain W/SW of the KILX CWA. Small cluster of showers/storms associated with this feature will drop into northern Missouri over the next few hours, then will gradually dissipate later this morning as it pushes toward the ridge axis. Am therefore expecting mostly sunny and dry conditions today with highs in the middle 80s. A series of upper-level waves is expected to reinforce the mean trough over eastern Canada and the Great Lakes over the next couple of days, with the first wave pushing a cold front southward toward central Illinois by late Monday. Models in relatively good agreement that boundary will sag into the northern KILX CWA by 12z Tue accompanied by scattered showers/thunder. Models have trended slightly faster with the approach of the front, with both the NAM and GFS now bringing precip into the W/NW as early as Monday afternoon. Have therefore added low chance PoPs from the Peoria area northward late in the day. Better rain chances arrive Monday night into Tuesday as front approaches and gradually stalls across the area. LONG TERM...Wednesday through Saturday Main forecast concern in the extended is how far south front will get pushed as additional short-wave energy deepens the Great Lakes trough later in the week. Both the 12z Aug 2 and 00z Aug 3 runs of the GFS featured a prominent surface high building southward into the Great Lakes, pushing the cold front south of the Ohio River by Thursday. This solution would bring an end to the rain chances as a slightly cooler/drier airmass arrives during the Thursday through Saturday time frame. Meanwhile the 12z ECMWF offered a much different solution showing a weaker high which subsequently kept the boundary further north across central Illinois. 00z run of the ECMWF has changed its tune completely and now looks a lot more like the GFS. As a result, have begun to trim PoPs from north to south later in the week as confidence is growing that front will drop south of the area by Thursday. At this time, will maintain low chance PoPs for both Thursday/Friday, but these will likely be removed completely with later forecasts as better model consistency is achieved. Barnes && .AVIATION... ISSUED 1139 PM CDT Sat Aug 2 2014 Forecast concern focused on potential for light fog the rest of tonight. Moisture levels a bit higher than last night, with dew points expected to remain at or above 60 degrees over most of the area. Latest HRRR guidance indicates the best shot for lower visibilities in fog would be near KSPI, and this area also was affected earlier Saturday morning. Will hit that area a little harder than the other TAF sites with a TEMPO group of around 1SM, with 2-3SM elsewhere. Beyond that, VFR conditions to prevail. Any ceilings that form later Sunday afternoon and evening will likely be at or above 6000 feet. Geelhart && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1258 AM CDT SUN AUG 3 2014 .DISCUSSION... 156 PM CDT TONIGHT... SFC RIDGE REMAINS OVERHEAD THIS AFTERNOON...WHICH HAS LIMITED THE COVERAGE OF CLOUDS AND CONTINUES TO PROVIDE MINIMAL WIND FOR THE CWFA. A LAKE BREEZE WAS TRYING TO FORM ALONG THE SHORELINE...AND WILL LIKELY BECOME MORE NOTICEABLE LATER THIS AFTERNOON AS THE INLAND AREAS WARM INTO THE LOW 80S. MEANWHILE ALONG THE IMMEDIATE LAKESHORE...LAND SITES WILL LIKELY REMAIN IN THE LOWER/MIDDLE 70S THIS AFTERNOON. LLVL MOISTURE HAS ALSO BEEN MORE PLEASANT...WITH DEW POINTS HOVERING AROUND 60 AND PWAT VALUES LESS THAN 1". GUIDANCE CONTINUES TO SUGGEST THIS AFTN WILL REMAIN DRY...AND LATEST LOCAL ARW8KM HAS INDICATED EVEN LESS CLOUDS DEVELOPING UNDERNEATH THE SFC RIDGE. SFC RIDGE REMAINS OVERHEAD THRU THIS EVENING/OVERNIGHT...WHICH SHUD ALLOW FOR A DRY PERIOD. CONFIDENCE...HIGH. SUNDAY THROUGH MON NGT... A MID-LVL WAVE OVER THE CENTRAL/NORTHERN PLAINS WILL STEADILY SLIDE EAST AND SHUD ARRIVE OVER THE FORECAST AREA CLOSER TO DAYBREAK SUN. THE SFC WAVE WILL BE DRIFTING EAST...ALLOWING THE FLOW TO TURN SOUTHERLY TO SOUTHWESTERLY. A CHANNEL OF INCREASED LLVL MOISTURE WILL LAYOUT FROM NORTHERN MISSOURI STRETCHING NORTHEAST THROUGH THE NORTHERN CWFA INTO NORTHERN LAKE MICHIGAN. THE COMBINATION OF AN APPROACHING WEAK WAVE AND INCREASED LLVL MOISTURE...ALL POINTS TOWARDS SOME PRECIP/STORMS POSSIBLE LATE SUN MORNING THRU AFTN. ALTHOUGH THAT BEING SAID...GUIDANCE SUGGESTS THE WAVE WILL BE IN A WEAKENING PHASE AS IT ARRIVES AND THE LACK OF FORCING SEEMS TO SUGGEST THAT ANY CONVECTION THAT DEVELOPS WILL BE ISOLATED AND LIKELY CONFINED TO AREAS ALONG AND NORTH OF I-80 IN NORTHERN IL. MID-LVL TROUGH REMAINS OVER THE EASTERN GREAT LAKES...WHICH SHUD KEEP OUR FORECAST AREA GENERALLY IN A WEAK NORTHWEST FLOW THRU MON. SOLUTIONS CONTINUE TO POINT TOWARDS A SERIES OF WEAK WAVES SLIDING SOUTHEAST WHICH COULD CONTINUE THE LOW POPS SUN NGT THRU MON NGT. HAVE HELD ONTO A DRY FORECAST FOR THE FAR SOUTHERN CWFA THROUGH MON. MON EVE THE LOCAL ARW8KM IS INDICATING A SLIGHTLY STRONGER WAVE ARRIVING LATE MON EVE...THUS HAVE NUDGED POPS UP FOR THE ENTIRE AREA. TEMPS BOTH SUN/MON WILL GENERALLY BE SEASONAL...IN THE LOW 80S. HUMIDITY WILL BE SLIGHTLY HIGHER WITH DEW POINTS IN THE LOW 60S...NEARING THE MID/UPR 60S MON NGT. TUESDAY...MON NGT A BROAD SFC RIDGE OVER THE CANADIAN PRAIRIES WILL DRIFT SOUTHEAST...WITH A STALLED FRONTAL BOUNDARY OVER THE FORECAST AREA THRU TUE. GUIDANCE HAS BEEN LEANING TOWARDS THIS FEATURE BEING FOCUSED OVER THE CENTRAL CWFA TUE...WHICH WOULD ALLOW FOR A COOLER NORTHEAST FLOW ACROSS THE NORTHERN CWFA. MEANWHILE THE SOUTHERN CWFA WILL STILL BE IN THE LOW 80S. STILL LOOKS FAVORABLE FOR CONVECTIVE CHANCES TUE...SO HAVE HELD ONTO THE CHC POPS. TROUGH AXIS PIVOTS OVERHEAD TUE EVE...WITH BROAD SFC RIDGE PROGGED IT IS POSSIBLE DRY CONDS COULD DEVELOP TUE NGT. UNFORTUNATELY WITH THE LACK OF A STRONG PUSH TO MOVE THE STALLED FRONTAL BOUNDARY FURTHER SOUTH...AND A DEVELOPING WAVE OVER THE COLORADO FRONT-RANGE TUE EVE...FEEL HOLDING ONTO LOW CHC POPS AT THIS TIME LOOKS APPROPRIATE. CONFIDENCE...MEDIUM. WEDNESDAY THROUGH SATURDAY... NORTH ATLANTIC RIDGE WILL BE WEAKENING...ALLOWING THE BLOCKED FLOW OVER THE CONUS TO BECOME A LITTLE MORE FLUID. HIGH AMPLITUDE RIDGE ACROSS THE ROCKIES WILL START TO FLATTEN WITH TIME...WHICH SHOULD ALLOW FOR A SEMI-ZONAL PATTERN FOR THE SECOND HALF OF NEXT WEEK. CURRENT GFS/EC SOLUTIONS HAVE COME INTO BETTER AGREEMENT THAT WEAK MID-LVL RIDGING WILL PUSH OVERHEAD WED/THUR WITH SFC RIDGE...AND COULD PRODUCE A FEW DRY PERIODS NEXT WEEK. BEYOND THUR THOUGH GUIDANCE STARTS TO DIFFER WITH ENSEMBLES STILL SHOWING CONSIDERABLE SPREAD IN THE NEAR SFC FIELDS. LONGWAVE PATTERN STILL IS SUGGESTIVE OF A TROUGH DEVELOPING OVER THE MID-ATLANTIC AND COULD HELP TO KEEP THE GREAT LAKES IN A SEMI-FLAT FLOW TRENDING NORTHWEST. TEMPS COULD PUSH BACK BELOW SEASONAL CONDS FOR THE START OF THE EXTENDED...BUT SHUD THEN RETURN TO THE LOW 80S. THEN AS NOTED EARLIER...PERIODIC CHANCES FOR SHOWERS AND THUNDERSTORMS WITH THE GREATEST POSSIBILITY BEING THE FAR WEST/SOUTH CWFA AS A PARKED FRONTAL BOUNDARY WILL BE ORIENTED FROM THE CENTRAL PLAINS SOUTHEAST THROUGH THE TENN VALLEY. CONFIDENCE...MEDIUM. BEACHLER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * SMALL CHANCE OF ISOLATED AFTERNOON TSRA. * WIND SHIFT TO EAST POSSIBLE WITH LAKE BREEZE LATE THIS AFTERNOON. RATZER //DISCUSSION...UPDATED 06Z... CALM OR LIGHT/VARIABLE WINDS ARE EXPECTED TO BECOME WEST- SOUTHWEST AFTER SUNRISE THIS MORNING. GRADIENT REMAINS WEAK ENOUGH THAT A LAKE BREEZE WILL LIKELY DEVELOP...THOUGH HOW FAR INLAND IT MOVES IS UNCERTAIN. MOST HIGH-RES GUIDANCE KEEPS THE BOUNDARY EAST OR ORD/MDW THROUGH THE AFTERNOON AND HAVE ELECTED TO KEEP WIND SHIFT OUT OF TAFS AT THIS POINT EXCEPT AT GYY. POTENTIAL FOR ISOLATED TSRA RETURNS TODAY AS UPPER TROUGH MOVES OVER REGION. FORECAST SOUNDINGS DEPICT UNSTABLE THERMODYNAMIC PROFILES WITH LITTLE/NO CAP BY EARLY AFTERNOON. WEAK WINDS AND LACK OF ORGANIZED CONVERGENCE ARE THE ONLY LIMITS TO DEVELOPMENT OF SOME TSRA...AND LAKE BREEZE BOUNDARY COULD FOCUS FOR DEVELOPMENT ESPECIALLY NORTH TOWARD WI WHERE INSTABILITY WILL BE GREATER. HAVE MAINTAINED PROB30 MENTION AT ORD AND ADDED SAME AT RFD WHERE POTENTIAL...WHILE STILL LOW...WILL BE A LITTLE HIGHER THAN AREAS FARTHER SOUTH/SOUTHEAST. IF DEVELOPMENT DOES OCCUR HOWEVER...TSRA WILL LIKELY SPREAD ALONG OUTFLOW BOUNDARIES OR LAKE BREEZE IF IT DEVELOPS. RATZER //ORD AND MDW CONFIDENCE...UPDATED 06Z... * LOW CONFIDENCE IN TSRA COVERAGE THIS AFTERNOON. * LOW CONFIDENCE IN LAKE BREEZE PASSAGE/WIND SHIFT TO EAST THIS AFTERNOON. RATZER //OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z... MONDAY AND TUESDAY...SLIGHT CHANCE OF TSRA BUT MAINLY VFR. WEDNESDAY THROUGH FRIDAY...PREDOMINANTLY VFR. IZZI && .MARINE... 228 PM CDT NO MAJOR CONCERNS OVER THE LAKE FOR THE COMING DAYS. HIGH PRESSURE REMAINS IN CONTROL THIS AFTERNOON AND EVENING. WEAK LOW PRESSURE WILL GLIDE THROUGH THE NORTHERN LAKES AND SOUTHERN ONTARIO THE NEXT FEW DAYS. THE MAIN IMPACT WILL BE TO INCREASE THE GRADIENT ACROSS THE LAKE ON SUNDAY THOUGH SOUTHERLY WINDS REMAIN 15 KT OR LESS. AS THESE WEAK SYSTEMS PASS TO THE EAST...HIGH PRESSURE BUILDS OVER LAKE SUPERIOR AND WILL PUSH A WEAK COLD FRONT THROUGH THE NORTHERN HALF OF THE LAKE BEFORE DISSIPATING WITH A SWITCH BACK TO MORE OF A NORTHERLY WIND PATTERN ON MONDAY. MEANWHILE...LOW PRESSURE WILL ORGANIZE IN THE PLAINS BUT WILL BE SLOW TO APPROACH THE AREA. A FEW WEAK SURFACE LOWS MAY PASS BY WELL TO THE SOUTH MAINTAINING A NORTH TO NORTHEAST FLOW THROUGH MID TO LATE WEEK. KMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 1139 PM CDT Sat Aug 2 2014 .DISCUSSION... ISSUED 837 PM CDT Sat Aug 2 2014 High pressure axis extending southwest from lower Michigan into northern Missouri early this evening. Diurnal cumulus has faded and we may see a few high clouds move in overnight, but mostly clear skies to prevail. Temperatures still on track to fall into the upper 50s and lower 60s overnight. Sent an update earlier to adjust the sky grids, but no changes needed to the worded forecasts. Geelhart && .AVIATION... ISSUED 1139 PM CDT Sat Aug 2 2014 Forecast concern focused on potential for light fog the rest of tonight. Moisture levels a bit higher than last night, with dew points expected to remain at or above 60 degrees over most of the area. Latest HRRR guidance indicates the best shot for lower visibilities in fog would be near KSPI, and this area also was affected earlier Saturday morning. Will hit that area a little harder than the other TAF sites with a TEMPO group of around 1SM, with 2-3SM elsewhere. Beyond that, VFR conditions to prevail. Any ceilings that form later Sunday afternoon and evening will likely be at or above 6000 feet. Geelhart && .PREV DISCUSSION... ISSUED 148 PM CDT Sat Aug 2 2014 Models in general agreement with overall evolution of upper trough over the Great Lakes and the Midwest gradually beginning to shift east of the region by late next week. However, individual wave timing and strength have a significant bearing on the forecast and leads to increased uncertainty. SHORT TERM...Tonight through Monday Cumulus are suppressed under high pressure this afternoon though boundary layer moisture remains in place with dew points similar to what was in place in dry areas at this time yesterday. The combination of the trapped low-level moisture, clear skies, and light winds will likely lead to some patchy fog again late tonight. 12z NAM moves some precip into northern forecast area Sunday and even more so on Monday. Although there will be waves rotating through the long wave trough over eastern Canada, question is how much moisture will interact with the energy. Stability remains relatively limited per forecast soundings with warming mid-levels and slowly building 500mb heights. There is also not a clear indication of surface boundaries to focus convergence. Wouldn`t completely rule out convection at some point Sunday and/or Monday afternoon, but coverage should remain isolated and will leave PoPs below slight chance category for now. LONG TERM...Monday Night through Saturday Heights begin to fall again Monday Night and Tuesday as final vort max rotates around eastern trough and pushes its surface reflection in the form of a cold front. The front should provide a focus for the development of thunderstorms. Deep moisture should remain limited as the Gulf remains cutoff. Evapotranspiration should provide enough for scattered storms, but widespread precip will likely need to wait until southerly moisture advection sets up Wednesday Night and Thursday. Big model differences focus on how far south the cold front can push before the flow weakens and moisture becomes available. GFS is strongest with the push behind the front with overrunning precip behind the front clearing central and southeast Illinois Thursday and Thursday Night. The ECMWF is much weaker with the upper energy and stalls the front over the southern half of Illinois from Tuesday through Friday bringing periodic chances for MCS development along and north of the front. The 12z ECMWF will be favored as it is more consistent with the 00z suite. Will therefore keep more clouds and PoPs in place across the area than would be suggested by the GFS with rain chances persisting through the weak with the axis of the higher QPF slowly shifting south with time. It is likely that much more detail as to timing and track can be added as the period approaches. Model temperatures also vary significantly given the differences in frontal position. The GFS being further south with the cold front is 2-4C colder than the ECMWF at 850 mb through the end of the week. Will go closer to the smaller diurnal range and overall warmer solution of the ECMWF. Barker && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS DES MOINES IA
106 PM CDT SUN AUG 3 2014 .UPDATE... ISSUED AT 1101 AM CDT SUN AUG 3 2014 A FEW TWEAKS WITH THE MORNING UPDATE...MAINLY DUE TO PRECIP TRENDS. RAP SEEMS TO DEPICT SOME SUBSIDENCE BEHIND DEPARTING WEAK CONVECTIVE CLUSTERS AND ELEVATED KINEMATICALLY DRIVEN MN CONVECTION SHOULD MOVE MORE EAST THAN SOUTH. ALTHOUGH CAP IS ERODING...SURFACE CONVERGENCE IS WEAK SO DO NOT MUCH SURFACE BASED POTENTIAL. HI RES MODELS SUGGEST THAT AS WELL SO HAVE CAPPED POPS AT SLIGHTS/ISOLATED WORDING. LITTLE CHANGE TO TEMPS OUTSIDE OF LOWERING E CENTRAL A TOUCH WHERE RAIN AND CLOUDS LINGERED. && .SHORT TERM /TODAY/... ISSUED AT 311 AM CDT SUN AUG 3 2014 AIRMASS MORE UNSTABLE THIS MORNING THAN THE PAST SEVERAL DAYS AS AN EXTENSION OF COLORADO LOW PRESSURE HAS REACHED INTO SOUTH CENTRAL NEBRASKA AND HAS HELPED VEER THE LOW LEVEL JET INTO THE MID MISSOURI VALLEY. UPPER PV ANOMALY IS PASSING ACROSS CENTRAL IOWA CURRENTLY WITH THE MID LEVEL SHORTWAVE SLIGHTLY LAGGING. THE OVERALL RESULT IS A THUNDERSTORM COMPLEX MOVING SOUTHEAST ACROSS SOUTHWEST IA WITH MORE SPORADIC DEVELOPMENT NORTH AND EAST OF THIS REGION. THE ACTIVITY SHOULD DIMINISH IN AREAL COVERAGE AS THE AFOREMENTIONED UPPER LEVEL ENERGY PASSES TO THE SOUTHEAST LATER THIS MORNING. ANOTHER SHORTWAVE EMBEDDED IN THE NORTHWEST FLOW WILL APPROACH NORTHERN IOWA BY MID TO LATE AFTERNOON AND IS EXPECTED TO ARRIVE WITH A CONVECTIVELY UNSTABLE AIRMASS IN PLACE WITH DIURNAL HEATING OCCURRING. THIS SYSTEM SHOULD FORCE ENOUGH VERTICAL ASCENT TO TRIGGER SCATTERED THUNDERSTORMS BY 00Z. THESE STORMS WILL BRING AN ATTENDANT LARGE HAIL THREAT WITH THE STRONGEST UPDRAFTS AS MUCAPES APPROACH 2000 J/KG THIS AFTERNOON ALONG WITH MODEST DEEP LAYER SHEAR NEAR 25 KTS. .LONG TERM /TONIGHT THROUGH SATURDAY/... ISSUED AT 311 AM CDT SUN AUG 3 2014 FORECAST CONCERN FOR EXTENDED WILL CONTINUE TO REVOLVE AROUND PRECIPITATION CHANCES...WITH LOW CONFIDENCE IN PRECIPITATION CHANCES FOR BEGINNING OF PERIOD BEFORE MID WEEK SYSTEM PUSHES THROUGH. NORTHWESTERLY FLOW WILL REMAIN IN PLACE ACROSS IOWA FOR THE BEGINNING OF THE PERIOD AS RIDGE REMAINS ACROSS ROCKIES. WITH GENERALLY WEAK SURFACE FLOW...PRECIPITATION CHANCES WILL COME AS SEVERAL WAVES PUSH SOUTHEAST THROUGH UPPER LEVEL FLOW. FOR TONIGHT...MODELS HAVE BEGUN TO PULL WAVE FURTHER SOUTH TO NEAR MO/IA BORDER. IN ADDITION...GIVEN BEST FORCING ACROSS FAR SOUTHWESTERN IOWA...HAVE PULLED POPS FURTHER SOUTH. ISENTROPIC ANALYSIS SHOWS BEST MOISTURE ALSO IN THIS AREA...AND MAY BE TOO LOW ON POPS IN SOUTHERN CWA. AS WAVE PUSHES EASTWARD WILL SEE CHANCES FOR PRECIPITATION SPREADING ACROSS THE CWA. ANTICIPATE PRECIPITATION TO DIMINISH INTO THE LATE MORNING HOURS MONDAY BEFORE ADDITIONAL ROUNDS OF SCATTERED THUNDERSTORMS ARE POSSIBLE MONDAY AFTERNOON WITH DIURNAL HEATING. AGAIN...LIMITED FORCING FOR PRECIPITATION THOUGH BEST INSTABILITY INDICATED IN THE EAST AND NORTH AND HAVE INCREASED POPS THERE. DECENT INSTABILITY WITH LACKING SHEAR MAY ALLOW FOR A FEW STRONG STORMS MONDAY AFTERNOON. ADDITIONAL WAVE WILL DROP SOUTH INTO IOWA FOR MONDAY NIGHT...THOUGH AGAIN MODELS HAVE COME INTO BETTER ALIGNMENT WITH FURTHER SOUTH SOLUTION...AND HAVE TRENDED POPS SOUTH. MAIN SYSTEM FOR EXTENDED WILL BEGIN TO INFLUENCE AREA LATE TUESDAY AS MUCH STRONGER WAVE PUSHES SOUTH INTO IOWA. MODELS HAVE AGAIN COME INTO BETTER AGREEMENT WITH THIS SYSTEM...TRENDING TOWARDS THE ECMWF SOLUTION. BEST CHANCES FOR WIDESPREAD...AND POTENTIALLY HEAVY...RAIN WILL COME TUESDAY INTO WEDNESDAY AS SYSTEM PUSHES THROUGH. HOWEVER...HIGH PRESSURE ACROSS NORTHERN PLAINS WILL IMPACT HOW FAR NORTH AND EAST PRECIPITATION FROM SYSTEM GETS. ATTM...HAVE KEPT POPS WIDESPREAD ACROSS CWA...THOUGH MAY NEED TO BE SCALED IF SYSTEM PULLS FURTHER WEST. THIS SYSTEM WILL BRIEFLY BREAK DOWN ROCKIES RIDGE...AND ALLOW FOR COOLER TEMPERATURES THROUGH WEEKS END...BEFORE LARGE UPPER LEVEL LOW PRESSURE SYSTEM WILL PUSH ACROSS SOUTHERN CANADA WITH BOUNDARY INTO IOWA...WHICH WILL ALLOW FOR ADDITIONAL CHANCES FOR PRECIPITATION THROUGH THE END OF THE PERIOD...THOUGH AGAIN HAVE LOWER CONFIDENCE IN TIMING AND LOCATION OF LATER PERIOD PRECIPITATION AS MODELS AGAIN DO NOT HAVE GOOD AGREEMENT ON PRECIPITATION WITH GFS FASTER THAN ECMWF. && .AVIATION...03/18Z ISSUED AT 106 PM CDT SUN AUG 3 2014 VFR CONDITIONS ARE ANTICIPATED THROUGH THE EVENING. OUTLOOK FOR CONVECTION HAS DIMINISHED SO MENTION HAS BEEN REMOVED DUE TO LITTLE PREDICTABILITY. MAIN CONCERN MAY BE VSBY TRENDS OVERNIGHT. ALTHOUGH RESTRICTIONS DID NOT OCCUR LAST NIGHT...MOS GUIDANCE CONSENSUS SUGGESTS IFR/LIFR VSBYS BEFORE SUNRISE. DEWPOINTS HAVE RISEN A FEW DEGREES SINCE YESTERDAY WITH LIGHT WINDS AGAIN AND PATCHY MORNING RAINS SO SOME RESTRICTIONS ARE POSSIBLE. HAVE NOT GONE ALL IN YET...BUT DID MENTION MVFR/VFR VSBYS FOR A START. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ UPDATE...SMALL SHORT TERM...DONAVON LONG TERM...AWB AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1102 AM CDT SUN AUG 3 2014 .UPDATE... ISSUED AT 1101 AM CDT SUN AUG 3 2014 A FEW TWEAKS WITH THE MORNING UPDATE...MAINLY DUE TO PRECIP TRENDS. RAP SEEMS TO DEPICT SOME SUBSIDENCE BEHIND DEPARTING WEAK CONVECTIVE CLUSTERS AND ELEVATED KINEMATICALLY DRIVEN MN CONVECTION SHOULD MOVE MORE EAST THAN SOUTH. ALTHOUGH CAP IS ERODING...SURFACE CONVERGENCE IS WEAK SO DO NOT MUCH SURFACE BASED POTENTIAL. HI RES MODELS SUGGEST THAT AS WELL SO HAVE CAPPED POPS AT SLIGHTS/ISOLATED WORDING. LITTLE CHANGE TO TEMPS OUTSIDE OF LOWERING E CENTRAL A TOUCH WHERE RAIN AND CLOUDS LINGERED. && .SHORT TERM /TODAY/... ISSUED AT 311 AM CDT SUN AUG 3 2014 AIRMASS MORE UNSTABLE THIS MORNING THAN THE PAST SEVERAL DAYS AS AN EXTENSION OF COLORADO LOW PRESSURE HAS REACHED INTO SOUTH CENTRAL NEBRASKA AND HAS HELPED VEER THE LOW LEVEL JET INTO THE MID MISSOURI VALLEY. UPPER PV ANOMALY IS PASSING ACROSS CENTRAL IOWA CURRENTLY WITH THE MID LEVEL SHORTWAVE SLIGHTLY LAGGING. THE OVERALL RESULT IS A THUNDERSTORM COMPLEX MOVING SOUTHEAST ACROSS SOUTHWEST IA WITH MORE SPORADIC DEVELOPMENT NORTH AND EAST OF THIS REGION. THE ACTIVITY SHOULD DIMINISH IN AREAL COVERAGE AS THE AFOREMENTIONED UPPER LEVEL ENERGY PASSES TO THE SOUTHEAST LATER THIS MORNING. ANOTHER SHORTWAVE EMBEDDED IN THE NORTHWEST FLOW WILL APPROACH NORTHERN IOWA BY MID TO LATE AFTERNOON AND IS EXPECTED TO ARRIVE WITH A CONVECTIVELY UNSTABLE AIRMASS IN PLACE WITH DIURNAL HEATING OCCURRING. THIS SYSTEM SHOULD FORCE ENOUGH VERTICAL ASCENT TO TRIGGER SCATTERED THUNDERSTORMS BY 00Z. THESE STORMS WILL BRING AN ATTENDANT LARGE HAIL THREAT WITH THE STRONGEST UPDRAFTS AS MUCAPES APPROACH 2000 J/KG THIS AFTERNOON ALONG WITH MODEST DEEP LAYER SHEAR NEAR 25 KTS. .LONG TERM /TONIGHT THROUGH SATURDAY/... ISSUED AT 311 AM CDT SUN AUG 3 2014 FORECAST CONCERN FOR EXTENDED WILL CONTINUE TO REVOLVE AROUND PRECIPITATION CHANCES...WITH LOW CONFIDENCE IN PRECIPITATION CHANCES FOR BEGINNING OF PERIOD BEFORE MID WEEK SYSTEM PUSHES THROUGH. NORTHWESTERLY FLOW WILL REMAIN IN PLACE ACROSS IOWA FOR THE BEGINNING OF THE PERIOD AS RIDGE REMAINS ACROSS ROCKIES. WITH GENERALLY WEAK SURFACE FLOW...PRECIPITATION CHANCES WILL COME AS SEVERAL WAVES PUSH SOUTHEAST THROUGH UPPER LEVEL FLOW. FOR TONIGHT...MODELS HAVE BEGUN TO PULL WAVE FURTHER SOUTH TO NEAR MO/IA BORDER. IN ADDITION...GIVEN BEST FORCING ACROSS FAR SOUTHWESTERN IOWA...HAVE PULLED POPS FURTHER SOUTH. ISENTROPIC ANALYSIS SHOWS BEST MOISTURE ALSO IN THIS AREA...AND MAY BE TOO LOW ON POPS IN SOUTHERN CWA. AS WAVE PUSHES EASTWARD WILL SEE CHANCES FOR PRECIPITATION SPREADING ACROSS THE CWA. ANTICIPATE PRECIPITATION TO DIMINISH INTO THE LATE MORNING HOURS MONDAY BEFORE ADDITIONAL ROUNDS OF SCATTERED THUNDERSTORMS ARE POSSIBLE MONDAY AFTERNOON WITH DIURNAL HEATING. AGAIN...LIMITED FORCING FOR PRECIPITATION THOUGH BEST INSTABILITY INDICATED IN THE EAST AND NORTH AND HAVE INCREASED POPS THERE. DECENT INSTABILITY WITH LACKING SHEAR MAY ALLOW FOR A FEW STRONG STORMS MONDAY AFTERNOON. ADDITIONAL WAVE WILL DROP SOUTH INTO IOWA FOR MONDAY NIGHT...THOUGH AGAIN MODELS HAVE COME INTO BETTER ALIGNMENT WITH FURTHER SOUTH SOLUTION...AND HAVE TRENDED POPS SOUTH. MAIN SYSTEM FOR EXTENDED WILL BEGIN TO INFLUENCE AREA LATE TUESDAY AS MUCH STRONGER WAVE PUSHES SOUTH INTO IOWA. MODELS HAVE AGAIN COME INTO BETTER AGREEMENT WITH THIS SYSTEM...TRENDING TOWARDS THE ECMWF SOLUTION. BEST CHANCES FOR WIDESPREAD...AND POTENTIALLY HEAVY...RAIN WILL COME TUESDAY INTO WEDNESDAY AS SYSTEM PUSHES THROUGH. HOWEVER...HIGH PRESSURE ACROSS NORTHERN PLAINS WILL IMPACT HOW FAR NORTH AND EAST PRECIPITATION FROM SYSTEM GETS. ATTM...HAVE KEPT POPS WIDESPREAD ACROSS CWA...THOUGH MAY NEED TO BE SCALED IF SYSTEM PULLS FURTHER WEST. THIS SYSTEM WILL BRIEFLY BREAK DOWN ROCKIES RIDGE...AND ALLOW FOR COOLER TEMPERATURES THROUGH WEEKS END...BEFORE LARGE UPPER LEVEL LOW PRESSURE SYSTEM WILL PUSH ACROSS SOUTHERN CANADA WITH BOUNDARY INTO IOWA...WHICH WILL ALLOW FOR ADDITIONAL CHANCES FOR PRECIPITATION THROUGH THE END OF THE PERIOD...THOUGH AGAIN HAVE LOWER CONFIDENCE IN TIMING AND LOCATION OF LATER PERIOD PRECIPITATION AS MODELS AGAIN DO NOT HAVE GOOD AGREEMENT ON PRECIPITATION WITH GFS FASTER THAN ECMWF. && .AVIATION...03/12Z ISSUED AT 645 AM CDT SUN AUG 3 2014 ISOLD TO SCT THUNDERSTORMS ARE POSSIBLE DURING THE PERIOD AT ALL SITES. BEST POTENTIAL EARLY IN THE PERIOD WILL BE NEAR KOTM THEN KALO AND KMCW LATER THIS AFTERNOON. MVFR CIGS POSSIBLE IN VICINITY OF THUNDERSTORMS OTHERWISE VFR WILL PERSIST. LIGHT SOUTHERLY WINDS WILL CONTINUE TODAY. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ UPDATE...SMALL SHORT TERM...DONAVON LONG TERM...AWB AVIATION...DONAVON
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
607 PM CDT Mon Aug 4 2014 ...UPDATE TO AVIATION... .SYNOPSIS... ISSUED AT 349 PM CDT MON AUG 4 2014 Cirrus was slowly overspreading the western sections of Kansas from the mean height ridge moving eastward from the Rockies into the High Plains. A weak surface pressure/850 mb height gradient enveloped the Central Plains. Relative low pressure over the eastern Colorado resulted in a northward oriented pressure gradient gradient across western Kansas resulting in generally south winds at most locations with little downslope. Temperatures warmed to around 90 degrees across in most locations as dew points mixed down to the upper 40s from Scott City to Hugoton. Hays, which is closer to the warmer air at 850 mb warmed into the upper 90s. && .SHORT TERM...(This evening through Tuesday) ISSUED AT 349 PM CDT MON AUG 4 2014 The temperature trend and dew points to a lesser degree seemed to have followed the consensus of the short term models blend fairly well this afternoon. This trend will continue to be followed into the rest of the forecast including Tuesday morning and into Tuesday. The cirrus overhead may have a small impact on overnight lows as the recent updates have bumped lows into the mid and upper 60s in most locations. The HRRR model continues to show isolated to widely scattered convection across south central Kansas late this afternoon likely based on reaching convective temperatures. Current trends suggest this is overdone as was the case Sunday afternoon, and PoPs will not be added at this time. No major shift in airmass is taking place tonight and the same general pattern of surface winds and diurnal warming is expected heading into Tuesday afternoon. A breakdown in the ridge by a mid level shortwave will create scattered convection across northeast and east central Colorado by late in the afternoon. Low PoPs will be included for about the western half of the area starting at about about 23 UTC, following previous forecasts. .LONG TERM...(Tuesday night through Monday) ISSUED AT 341 PM CDT MON AUG 4 2014 The upper level ridge will flatten out and be shunted southward during the next couple of days as a series of upper level shortwaves move up and over the ridge. These features will bring a chance of thunderstorms to the forecast area through this weekend. The slight chance of thunderstorms will start out across far western Kansas Tuesday night then across central Kansas Wednesday night. Otherwise expect partly cloudy skies. Winds will generally be from the south to south southwest Tuesday night through Thursday with a surface trough located across eastern Colorado and far western Kansas. A better chance of thunderstorms will be expected this weekend as the upper level ridge slould retrogrades towards the southwest United States. Winds will generally be from the southeast during this time frame as a stationary front will be located at the surface south of the area with a dome of high pressure to the north. Highs through the extended period will generally be in the low to mid 90s with lows in the upper 60s and lower 70s. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) ISSUED AT 605 PM CDT MON AUG 4 2014 VFR conditions will prevail at all TAF sites through late Tuesday morning. Southerly winds of 10 to 20kt will persist through early Tuesday morning as a lee side trough remains anchored across extreme eastern Colorado. The southerly winds will then pick up a little to around 15 to 25kt through Tuesday afternoon as the lee side trough strengthens. && .PRELIMINARY POINT TEMPS/POPS... DDC 68 93 69 95 / 0 10 20 20 GCK 68 90 68 94 / 0 20 20 20 EHA 66 91 67 95 / 0 20 20 10 LBL 66 92 69 96 / 0 10 20 10 HYS 68 96 70 94 / 0 10 20 30 P28 68 93 71 94 / 0 10 20 30 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...Russell SHORT TERM...Russell LONG TERM...Hovorka_42 AVIATION...JJohnson
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
351 PM CDT Sun Aug 3 2014 ...UPDATE TO LONG TERM... .SHORT TERM...(This evening through Monday) ISSUED AT 333 PM CDT SUN AUG 3 2014 This mornings convective allowing models allowed some room for convection to develop once again just north of the I-70 corridor and be driven southeast by the man flow, much like last evening. So far this afternoon the area of enhanced cu development across northwest Kansas has not shown signs of stronger shower or storm development although the GLD 88D was indicating rain in the HCA. We will continue to carry less than 20 PoPs trough the end of the afternoon and early evening to see how this evolves, especially given the increasingly robust HRRR model drives a few storms into Rush and Stafford counties. For the rest of the period including tonight into tomorrow, we followed the NAM and Raw Model Blend which seemed to do the best job collectively with temperatures and surface winds for yesterday. little overall change in airmass will take place with the upper ridge settling slightly farther east. .LONG TERM...(Monday night through Sunday) ISSUED AT 350 PM CDT SUN AUG 3 2014 Drier conditions will persist across western Kansas through early Tuesday afternoon as an upper level ridge axis shifts eastward across the Western High Plains. Medium range models then indicate the ridge breaking down late Tuesday as a series of H5 vort maxima associated with a shortwave eject out of the Rockies into the high plains of western Nebraska and western Kansas. A developing lee side trough will strengthen as the shortwave approaches while low/mid level moisture continues to pool slowly across central and portions of western Kansas. This will set the stage for possible thunderstorm development across portions of southwest and central Kansas Tuesday evening into Wednesday. Although low/mid level lapse rates will steepen through the afternoon period Tuesday, NAM/GFS model soundings show very little instability in regards to available CAPE with values well under 100 J/KG. This will likely hinder storm development through much of the afternoon with chances increasing Tuesday evening as CAPE begins to rise. Although less than favorable, a slightly strengthened flow aloft along with decent directional shear may be enough to support stronger thunderstorms with gusty winds the primary threat. Precip chances will shift eastward across western into central Kansas Wednesday as the surface trough migrates through. Thunderstorms will be possible again into Thursday as H5 vort maxima continue to move out of the Rockies into the Western High Plains. However, better chances will be more to the north across west central and central Kansas in association with the stronger flow. Seasonal temperatures will continue through Thursday as a south to southeasterly flow prevails through much of the period. This will reinforce the warm air mass already in place across western Kansas keeping highs up into the 90s(F) each day through the end of the week. && .AVIATION...(For the 18Z TAFS through 18Z Monday afternoon) ISSUED AT 1237 PM CDT SUN AUG 3 2014 A very slowly changing surface pressure pattern marked by relative high pressure over Missouri will result in light winds veering south with time through tonight. VFR - clear conditions are expected with only a very small chance of surface convergence/diurnally forced high based CB`s between around 22-and 02 near and east of KHYS. && .PRELIMINARY POINT TEMPS/POPS... DDC 65 92 69 94 / 0 0 0 10 GCK 63 92 68 94 / 0 0 0 20 EHA 64 91 67 95 / 0 0 0 10 LBL 65 93 69 96 / 0 0 0 20 HYS 67 95 70 93 / 20 0 0 10 P28 66 93 69 94 / 0 0 0 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Russell LONG TERM...JJohnson AVIATION...Russell
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
335 PM CDT Sun Aug 3 2014 ...updated short term... .SYNOPSIS... ISSUED AT 333 PM CDT SUN AUG 3 2014 Weak anticyclonic surface flow was in place over the Kansas High Plains with a weak moisture gradient from west to east. Surface dew points were in the lower 40s in the far west to around 60 degrees from Stafford country through Medicine lodge. Weak downslope through the Smoky Hills region likely added a few degrees to temperatures this afternoon, reaching the low 90s at Hays. The upper ridging pattern in place and light winds also were contributing to a significant lack of bulk shear across the area. The higher dew points of central Kansas contributed to higher CAPE values up to around 1500 j/kg in the south central Kansas counties. A weak surface convergence zone across northwest Kansas and sn Nebraska was a zone of current ongoing cu development && .SHORT TERM...(This evening through Monday) ISSUED AT 333 PM CDT SUN AUG 3 2014 This mornings convective allowing models allowed some room for convection to develop once again just north of the I-70 corridor and be driven southeast by the man flow, much like last evening. So far this afternoon the area of enhanced cu development across northwest Kansas has not shown signs of stronger shower or storm development although the GLD 88D was indicating rain in the HCA. We will continue to carry less than 20 PoPs trough the end of the afternoon and early evening to see how this evolves, especially given the increasingly robust HRRR model drives a few storms into Rush and Stafford counties. For the rest of the period including tonight into tomorrow, we followed the NAM and Raw Model Blend which seemed to do the best job collectively with temperatures and surface winds for yesterday. little overall change in airmass will take place with the upper ridge settling slightly farther east. .LONG TERM...(Monday through Saturday) ISSUED AT 317 AM CDT SUN AUG 3 2014 The upper level ridge currently situated over the Rockies and adjacent High Plains will flatten out somewhat through the early part of the extended period. Mainly dry weather will persist across western Kansas through Tuesday. Chances for showers and thunderstorms will increase from late Tuesday through Wednesday as an upper level disturbance lifts out of the Desert Southwest through the central Rockies and Plains through mid week. Model soundings are not overly unstable but a favorable warm advection pattern develops which should enhance upward vertical motion and thunderstorm development. Thursday should see a lull in precipitation chances as the energy from the first disturbance moves east of the region and upper level ridging briefly builds back into the central High Plains. The models show additional disturbances moving east through the Rockies into the northern and central Plains later in the week. Tough to say how much energy with these systems will move over Kansas as the stronger upper level westerly flow will reside over the northern portions of the country later in the week but for now, the chance/slight chance pops in the extended initialization look reasonable. High temperatures should be in the low to mid 90s through the period which is near seasonal normals for early August. && .AVIATION...(For the 18Z TAFS through 18Z Monday afternoon) ISSUED AT 1237 PM CDT SUN AUG 3 2014 A very slowly changing surface pressure pattern marked by relative high pressure over Missouri will result in light winds veering south with time through tonight. VFR - clear conditions are expected with only a very small chance of surface convergence/diurnally forced high based CB`s between around 22-and 02 near and east of KHYS. && .PRELIMINARY POINT TEMPS/POPS... DDC 65 92 69 94 / 0 0 0 10 GCK 63 92 68 94 / 0 0 0 20 EHA 64 91 67 95 / 0 0 0 10 LBL 65 93 69 96 / 0 0 0 20 HYS 67 95 70 93 / 20 0 0 10 P28 66 93 69 94 / 0 0 0 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...Russell SHORT TERM...Russell LONG TERM...Gerard AVIATION...Russell
AREA FORECAST DISCUSSION
NWS JACKSON KY
118 AM EDT SUN AUG 3 2014 .UPDATE... ISSUED AT 118 AM EDT SUN AUG 3 2014 UPDATED THE FORECAST TO ADD A DENSE FOG ADVISORY FOR MUCH OF EASTERN KENTUCKY. THE FOG SHOULD BEGIN TO LIFT BETWEEN 9 AND 10 AM. UPDATE ISSUED AT 1110 PM EDT SAT AUG 2 2014 FOG HAS DEVELOPED AND INTENSIFIED EARLY THIS EVENING...AND IS BECOMING MORE WIDESPREAD ACROSS THE NORTHEASTERN TWO THIRDS OF THE CWA. BEEFED UP THE FOG IN THE GRIDS AND ZONES FOR THE REMAINDER OF THE OVERNIGHT PERIOD. AS WE ARE HEADING INTO SUNDAY...IMPACT SHOULD BE RELATIVELY LOW AS FOG SHOULD HAVE BEGUN TO LIFT BY THE TIME CHURCH GOERS GET OUT. ALSO AM NOT CONVINCED FOG WILL BE WIDESPREAD ENOUGH TO WARRANT HEADLINES. HIT THE FOG HARDEST ALONG AND NORTHEAST OF A IRVINE TO MANCHESTER TO WHITESBURG LINE...WHERE LOCATIONS MOST LIKELY SAW EVENING CONVECTION AND RAINFALL. ISSUED A SPECIAL WEATHER STATEMENT TO HIGHLIGHT FOG FOR THESE AREAS. FURTHER SOUTHWEST WHERE LESS RAIN WAS EVIDENT WENT WITH PATCHY DENSE WORDING IN THE ZONES AND GRIDS. ALSO TWEAKED GRIDS FOR HOURLY TRENDS. NO OTHER CHANGES TO THE FORECAST PACKAGE ATTM. UPDATE ISSUED AT 827 PM EDT SAT AUG 2 2014 CONVECTIVE ACTIVITY IS DISSIPATING AT A RAPID PACE THIS EVENING AS AIR MASS IN PLACE STABILIZES. WILL REMOVE ALL MENTION OF THUNDER WITH NEXT UPDATE...AND POSSIBLY ALL POPS. FOG WILL LIKELY FORM THROUGH THE OVERNIGHT PERIOD. POTENTIAL IS ADDRESSED WELL IN THE PRESENT FORECAST. OTHERWISE BROUGHT GRIDS IN LINE WITH HOURLY OBS AND FRESHENED UP ZONE WORDING. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 301 PM EDT SAT AUG 2 2014 THE HRRR MODEL SEEMED TO HAVE THE BEST HANDLE ON THE SHOWER AND STORM ACTIVITY THAT HAS BEEN ONGOING ACROSS EASTERN KENTUCKY FOR THE PAST FEW HOURS. THEREFORE...THE HRRR SOLUTION WAS USED TO CREATE THE NEW FORECAST PRECIPITATION PROBABILITIES FOR THE AREA FOR THE REST OF THIS AFTERNOON THROUGH 2Z THIS EVENING. AFTER 2Z TONIGHT...THE NAM12 MODEL WAS USED. SHOWERS AND STORMS ARE EXPECTED TO PERSIST THROUGH ROUGHLY 2Z THIS EVENING...WITH THE PEAK ACTIVITY OCCURRING DURING PEAK HEATING HOURS THIS AFTERNOON. A SHORTWAVE TROUGH INTERACTING WITH LIMITED LOW LEVEL MOISTURE IS THE DRIVING FORCE FOR PRECIPITATION THIS AFTERNOON...AND WILL BE UNTIL THE TROUGH MOVES EAST OF THE AREA EARLY THIS EVENING. SOME OF THE STORMS THIS AFTERNOON HAVE BEEN A BIT STRONG AND CAPABLE OF PRODUCING SMALL HAIL...LOCALLY HEAVY RAINFALL...AND WIND GUSTS UP TO 30 MPH. AFTER THIS EVENING...HIGH PRESSURE WILL SETTLE OVER THE AREA...ALLOWING FOR A DRIER AND SLIGHTLY WARMER PATTERN. HIGHS ON SUNDAY ARE EXPECTED TO RISE INTO THE LOW TO MID 80S UNDER AMPLE SUNSHINE AND LIGHT WINDS. LOWS THE NEXT COUPLE OF NIGHTS WILL BOTTOM OUT AROUND 60...WHICH IS A BIT BELOW NORMAL FOR THIS TIME OF YEAR. THE WEATHER RELATED ISSUED TO LOOK OVERNIGHT WILL BE FOG FORMATION. FOG WILL BE POSSIBLE IN OUR RIVER VALLEYS OVERNIGHT. THE MAIN QUESTION WILL BE THE EXTENT AND DENSITY OF FOG THAT FORMS WHERE PRECIPITATION HAS ALREADY OCCURRED TODAY. THE OTHER FACTOR INVOLVED WITH THE FOG WILL BE THE AMOUNT OF CLOUD COVER THAT PERSISTS OVERNIGHT. IF THE CLOUDS CLEAR OUT MORE QUICKLY THEN FOG FORMATION WILL BE FAVORED...PARTICULARLY FOR LOCATIONS WHERE IT RAINED TODAY. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 403 PM EDT SAT AUG 2 2014 THE MODELS REMAIN IN DECENT AGREEMENT WITH THE LONG WAVE PATTERN THROUGH NEXT WEEKEND. OVERALL...THE FLOW LOOKS TO FLATTEN OUT ACROSS THE MISSISSIPPI VALLEY...WITH THE DEEPER AND PERSISTENT TROUGHING BECOMING MORE CONFINED TO THE NORTHEASTERN CONUS. FOR EASTERN KENTUCKY...DRY WEATHER WILL HANG IN THROUGH TUESDAY...BEFORE A COLD FRONT SAGS SOUTHEAST AND EVENTUALLY STALLS ACROSS OUR VICINITY. DAILY CHANCES OF SCATTERED SHOWERS AND THUNDERSTORMS WILL REIGN FROM TUESDAY NIGHT THROUGH NEXT WEEKEND. STAYED CLOSE TO THE BLENDED GUIDANCE...ALTHOUGH DID UNDERCUT A BIT IN THE POPS FURTHER OUT GIVEN THE LOW CONFIDENCE IN TRYING TO NAIL DOWN SMALLER SCALE FEATURES. TEMPERATURES WILL AVERAGE NEAR NORMAL THROUGH THE PERIOD AS WELL. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 118 AM EDT SUN AUG 3 2014 THERE IS A DENSE FOG ADVISORY OUT FOR MUCH OF EASTERN KENTUCKY FOR THE NORTHEASTERN TWO THIRDS OF THE AREA. IN THOSE AREA...THE FOG IS IN THE VALLEYS AND WELL AS ON SOME OF THE RIDGES. THE REST OF EASTERN KENTUCKY HAS OR WILL HAVE AREAS FOG OF DENSE FOG IN THE VALLEYS. THIS LOOKS LIKE ONE OF THOSE DAYS WHERE THE FOG WILL CONTINUE THICKEN AND EVENTUALLY MOVE INTO THE TAF STATIONS. THE MODEL GUIDANCE IS SPLIT AND THE GFS MOS IS MORE OPTIMISTIC THAN THE NAM AND THE LAMP GUIDANCE. WILL HAVE SOME TEMPO VLIFR IN ALL OF THE TAF STATIONS. SJS IS THE MOST LIKELY TO HAVE THE WORST CONDITIONS. ONCE THE FOG BURNS OFF BETWEEN 13-14Z...THE REST OF THE PERIOD WILL BE VFR. && .JKL WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR KYZ044- 050>052-058>060-104-106>120. && $$ UPDATE...JJ SHORT TERM...AR LONG TERM...GEOGERIAN AVIATION...JJ
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
402 PM CDT SUN AUG 3 2014 .DISCUSSION... FRONTAL BOUNDARY AND WEAK SURFACE LOW THAT WERE STALLED ACROSS THE FORECAST AREA HAVE DISSIPATED. SHOWERS AND THUNDERSTORMS HAVE TAKEN A LITTLE LONGER TO GET GOING TODAY BUT RADAR SHOWS QUITE A FEW SHOWERS AND THUNDERSTORMS DEVELOPING ALONG THE EASTERN AND WESTERN FRINGES OF THE CWA WHERE DEWPOINTS ARE GENERALLY IN THE LOWER TO MID 70S VS UPPER 60S ELSEWHERE. STORM MOTION PER THIS MORNINGS UPPER AIR SOUNDING IS A WHOPPING 1 KT. SO DONT EXPECT ANY SHOWER OVERHEAD TO MOVE AWAY FAST IN ANY WAY SHAPE OR FORM. IT WILL HAVE TO BASICALLY RAIN ITSELF OUT. MINOR STREET FLOODING WILL BE POSSIBLE UNDER MORE INTENSE CELLS. HRRR ONCE AGAIN OVER DOING COVERAGE TODAY BUT STILL BELIEVE THE DIURNAL TREND ITS SHOWING WITH MOST ACTIVITY DISSIPATED BY 04Z. ECMWF AND GFS MODELS SHOW UPPER LEVEL TROUGH THAT CURRENTLY EXTENDS SOUTH ACROSS THE ENTIRE GULF COAST WILL GRADUALLY LIFT NORTHEAST THE REMAINDER OF THIS WEEK AND INTO NEXT WEEKEND WHILE RIDGE CENTERED TO THE WEST BUILDS EAST. THIS ALONG WILL LEAVE CONVECTION DEVELOP TO JUST DAYTIME HEATING AND THUS A RETURN TO MORE TYPICAL SUMMERTIME SHOWERS AND STORMS. COVERAGE WILL REMAIN IN THE 20-40 PERCENT RANGE. TEMPERATURES TO REMAIN AT OR SLIGHTLY BELOW NORMAL UNTIL AT LEAST THE LATTER HALF OF THE WEEK. MEFFER && .AVIATION... VFR CONDITIONS WILL GENERALLY PREVAIL AT THE TERMINALS THROUGH THE TAF FORECAST PERIOD. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL BE POSSIBLE...PRIMARILY DURING THE REMAINDER OF THE AFTERNOON HOURS TODAY. 11 && .MARINE... WEAK HIGH PRESSURE WILL BUILD OVER THE NORTH GULF DURING THE WEEK RESULTING IN GENERALLY LIGHT AND AT TIMES VARIABLE WINDS AND LOW SEAS. 11 && .DECISION SUPPORT... DSS CODE...GREEN. DEPLOYED...NONE. ACTIVATION...NONE. ACTIVITIES...SLURRY SUPPORT. DECISION SUPPORT SERVICES (DSS) CODE LEGEND GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH VISIBILITY EVENT YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE. && .PRELIMINARY POINT TEMPS/POPS... MCB 71 91 71 90 / 20 30 20 30 BTR 72 90 72 91 / 20 30 20 30 ASD 72 91 72 88 / 30 40 20 30 MSY 76 90 76 89 / 30 40 20 30 GPT 76 90 77 92 / 30 40 20 30 PQL 71 91 72 90 / 30 40 20 30 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...NONE. GM...NONE. MS...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
346 AM CDT SUN AUG 3 2014 .SHORT TERM... THE OLD STATIONARY FRONT AND A BROAD LOW PRESSURE SYSTEM REMAIN IN PLACE TODAY. OVERNIGHT PRECIPITATION WAS ASSOCIATED WITH THE LOW PRESSURE SYSTEM. WITH THESE SMALL SCALE FEATURES AND A PWAT OF NEARLY 2 INCHES... SOME SHOWERS AND EVEN AN ISOLATED THUNDERSTORM ARE POSSIBLE AGAIN TODAY. RUC MEAN RH FROM H10 TO H5 HAS 85 PERCENT JUST OFFSHORE FOR THIS MORNING. EVEN WITH ALL THESE FACTORS...LOWERED THE POPS SOME FOR TODAY WITH THE RATIONAL THAT OFTEN A WEAKNESS AREA AWAY FROM THE SFC LOW ACTS TO DAMPEN RAIN CHANCES AS WE SAW THE LAST FEW DAYS OVER THE EASTERN PART OF OUR FORECAST AREA PER THE STP 8BIT DATA FROM THE WSR88D. MOST OF RAIN TODAY AND TOMORROW WILL BE INFLUENCED NEAR AND AROUND THE LOW. NEVERTHELESS... SOME SHOWERS AND AN ISOLATED THUNDERSTORM WILL STILL BE POSSIBLE. AREAS THAT DO RECEIVE RAIN CAN EXPECT THESE SLOW MOVING STORMS TO PRODUCE SOME HEAVY RAIN AND FREQUENT LIGHTNING. KEG .LONG TERM... AS THESE OLD BOUNDARIES GRADUALLY WASH OUT... WE WILL SEE A RETURN TO A NORMAL SUMMER REGIME WITH AFTERNOON THUNDERSTORMS ALONG SEA BREEZE FRONTS..BUT OVERALL DRIER. THE EAST COAST TROUGH WILL CONTINUE TO DOMINATE AND EVENTUALLY RELEASE SOME OF ITS GRIP ON THE SE US BY THE END OF THE WEEK AS HIGH PRESSURE BUILDS OVER THE DESERT SW AND THE BERMUDA HIGH TRIES TO NUDGE WESTWARD. KEG && .AVIATION... SOME PATCHY MVFR IN LIGHT RADIATIONAL FOG AT A FEW LOCATIONS THIS MORNING. OTHERWISE VFR CONDITIONS TO PREVAIL DURING THE DAY AND EVENING OUTSIDE LIMITED CONVECTION AREAS. DOWNBURST GUST POTENTIAL 25-30 KT TODAY. PATCHY SHALLOW RADIATIONAL FOG MAY ONCE AGAIN DEVELOP OVERNIGHT IN AREAS THAT MAY BE AFFECTED BY RAINFALL TODAY. 24/RR && .MARINE... BENIGN WINDS AND SEAS ARE EXPECTED TO PREVAIL NEXT 5 DAYS AS WEAK HIGH PRESSURE STAYS PARKED OVER THE NORTH GULF. THE GULF-LAND BREEZE CYCLE APPEARS TO BE PERTURBED BY LARGER SCALE FEATURES BUT NOCTURNAL CONVECTION IS STILL POSSIBLE EACH NIGHT FOCUSED ON SUBTLE CONVERGENCE BOUNDARIES...AS IS CURRENTLY THE CASE OVER AND SOUTH OF THE ATCHAFALAYA BAY. 24/RR && .DECISION SUPPORT... DSS CODE...GREEN. DEPLOYED...NONE. ACTIVATION...NONE. ACTIVITIES...SLURRY SUPPORT. DECISION SUPPORT SERVICES (DSS) CODE LEGEND GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH VISIBILITY EVENT YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE. && .PRELIMINARY POINT TEMPS/POPS... MCB 85 71 87 71 / 40 20 30 20 BTR 88 72 89 72 / 40 20 30 20 ASD 89 72 88 72 / 40 30 40 20 MSY 89 76 89 76 / 40 30 30 20 GPT 91 76 91 77 / 40 30 30 20 PQL 87 71 88 72 / 40 30 30 20 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...NONE. GM...NONE. MS...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
857 AM EDT SUN AUG 3 2014 .SYNOPSIS... WEAK LOW PRESSURE WILL TRACK NORTHEAST ALONG A STALLED FRONTAL BOUNDARY OFF THE NEW ENGLAND COAST TODAY. THE FRONTAL BOUNDARY WILL DRIFT OFF TO THE EAST TONIGHT AND MONDAY. A SLOW MOVING COLD FRONT WILL APPROACH FROM THE NORTHWEST ON TUESDAY AND WILL GRADUALLY PUSH EAST OF THE REGION ON WEDNESDAY. A TROUGH OF LOW PRESSURE WILL LINGER OVER THE AREA ON THURSDAY AND FRIDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST OVER THE WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... .UPDATE... A FEW MINOR CHANGES TO THE FORECAST THIS MORNING INCLUDING TAILORING SOUTHERN POPS CLOSER TO WHAT MESOSCALE MODELS HAVE OVER THE NEXT FEW HOURS. HRRR HAS A GOOD HANDLE ON PRECIPITATION THIS MORNING WHILE NAM IS A LITTLE FAST. INCREASED POPS OVER HIGHER TERRAIN THIS AFTERNOON. ISOLATED THUNDERSTORMS WILL POSE A BRIEF THREAT ONCE AGAIN THIS AFTERNOON. && PREVIOUS DISCUSSION...LOW PRESSURE TRACKING NORTHEAST ALONG A STALLED FRONTAL BOUNDARY OFF THE NEW ENGLAND COAST WILL KEEP HIGH CLOUDS ACROSS THE REGION FOR MUCH OF TODAY. EXPECT PRECIP TO ONCE AGAIN REMAIN OFFSHORE. EXPECT ENOUGH INSTABILITY TO DEVELOP ACROSS NORTHERN ZONES TO KICK OFF A FEW SHOWERS AND THUNDERSTORMS IN THE MOUNTAINS. HIGH TEMPS TODAY WILL BE ABOUT THE SAME AS SATURDAY WITH LOWER TO MID 70S ALONG THE COAST AND MID 70S TO NEAR 80 INLAND. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/... VARIABLE HIGH CLOUDS AND AREAS OF FOG OVERNIGHT AS STALLED FRONTAL BOUNDARY DRIFTS OFF TO THE EAST. AFTER A FEW EVENING SHOWERS OR THUNDERSTORMS IN THE NORTH EXPECT ACTIVITY TO DIE OFF. LOW TEMPS WILL GENERALLY BE IN THE MID TO UPPER 50S ACROSS THE REGION. ENTIRE FORECAST AREA WILL SEE A CHANCE OF SHOWERS OR THUNDERSTORMS ON MONDAY. EXPECT PARTLY TO MOSTLY SUNNY SKIES WITH HIGHS IN THE MID 70S TO MID 80S. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... AN UPPER LVL TROF MOVING IN FROM THE WEST BRINGS A SFC COLD FNT TOWARD THE REGION MONDAY NGT AND TUESDAY THEN THE FNT SLOWLY CROSSES THE REGION TUESDAY NGT AND WEDNESDAY. AT THIS TIME TROPICAL STORM BERTHA TRACKS TO THE NE STAYING WELL OUT TO SEA AND HAVING NO IMPACT ON OUR WX. THE FNT WILL RESULT IN MORE SHRA/TSTMS FOR THE FCST AREA...ESPECIALLY ON WEDNESDAY AS THE INTENSIFYING UPPER LEVEL FEATURE GETS CLOSER. THE FNT MOVES JUST OFFSHORE WEDNESDAY NGT CONTINUING THE CHC OF SHRA/TSTMS. ON THURSDAY A SECOND FNT MOVES THRU AS A VIGOROUS UPPER LEVEL SHORT WAVE TROF BECOMES A CUTOFF LOW AND MOVES OVER THE REGION. THIS UPPER LVL SYSTEM WILL REMAIN OVER THE REGION THRU FRIDAY ALONG WITH A SERIES OF WEAK SFC TROFS MOVING THRU THUS GIVING US A CHC OF SHRA/TSTMS. ON SATURDAY THE UPPER LEVEL SYSTEM SLOWLY MOVES OFF TO THE E AS AN UPPER LEVEL RIDGE BUILDS IN BEHIND IT ALLOWING A SFC HIGH PRESSURE SYSTEM TO ALSO BUILD IN FROM THE W. THIS SHOULD GIVE US IMPROVING WX ON SATURDAY. USED A BLEND OF VARIOUS MODELS...HPC GUIDANCE...PREVIOUS FCST FOR PERSISTENCE AND CLIMATOLOGY FOR THE LONG TERM FCST. && .AVIATION /13Z SUNDAY THROUGH THURSDAY/... SHORT TERM...AREAS OF MVFR/IFR CEILINGS AND VSBY IN PATCHY MORNING FOG... IMPROVING TO VFR. DITTO FOR TONIGHT AND MONDAY. LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...UNSETTLED WX PATTERN WITH A RISK OF SHRA/TSTMS EACH DAY WHICH MAY CREATE MVFR/IFR CONDITIONS...MORE SO IN THE AFTERNOON AND EVENING HOURS. && .MARINE... SHORT TERM...NO FLAGS. LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...TROPICAL STORM BERTHA MOVES TO THE NE STAYING WELL OUT TO SEA. HOWEVER THIS STORM MAY GENERATE SWELLS THAT IMPACT OUR COASTAL WATERS IN THE TUESDAY THRU WEDNESDAY TIME FRAME. OTHERWISE THE SFC WEATHER PATTERN HAS WEAK FEATURES DOMINATING THRU THE LONG TERM FCST PERIOD RESULTING IN WINDS AND SEAS BELOW SCA LEVELS. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$ UPDATE...HANES
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
300 AM EDT SUN AUG 3 2014 .SYNOPSIS... A FRONTAL BOUNDARY REMAINS NEARLY STATIONARY ALONG THE MID ATLANTIC COAST THROUGH MONDAY. AREAS OF LOW PRESSURE WILL TRACK NORTHEAST ALONG THIS BOUNDARY...KEEPING UNSETTLED CONDITIONS IN PLACE INTO EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... LATEST ANALYSIS SHOWING SFC TROUGH PERSISTING ALONG THE COASTAL AREAS WITH WEAK HIGH PRESSURE CENTERED OFF NEW ENGLAND NOSING SSW INTO THE MID ATLC. THIS IN SITU CAD SETUP MAKING FOR AN ANOMALOUSLY COOL EARLY AUGUST WX ACRS THE REGION...TEMPERATURES TDA GENLY NO BETTER THAN THE 70S. WILL HAVE HI PROB FOR SHRAS OVRNGT ERN PORTION (60-80%)...NOT RULING OUT LOCALLY HEAVY RA...BUT THAT APPEARS TO BE A LO PROB ATTM (UNLESS PAST COUPLE RUC RUNS TURNS OUT RIGHT W/ DEVELOPING/MOVING AREA OF MDT/HEAVY RA NE NR THE CST OVRNGT). HANGING ONTO 20% W. LO TEMPS FM THE M60S TO ARND 70F. MAIN CONCERN OVER THE NEXT 24 HRS CONTINUES TO BE HEAVY RAINFALL...AND ACRS MOST OF SE VA/NE NC PRECIP AMOUNTS HAVE AVERAGED 2-3" WITH LOCAL AMOUNTS OVER 4" RECEIVED. WHILE PRECIP THUS FAR TODAY HAS BEEN SOMEWHAT SPOTTY AND SPORADIC...THINK THERE ARE ENOUGH ATMOSPHERIC INGREDIENTS IN PLACE LATER TONIGHT TO JUSTIFY A FLOOD WATCH. PER COLLABORATION W/ NEIGHBORING OFFICES WENT FLOOD WATCH RATHER THAN FLASH FLOOD WATCH...ALTHOUGH SOME LOCALIZED FLASH FLOODING CAN`T BE RULED OUT LT TNGT OR SUN ESP IN URBAN AREAS. && .SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/... ON SUNDAY...LITTLE CHANGE SEEN IN OVERALL PATTERN WITH YET ANOTHER S/W ENHANCING RAINFALL PTNTL ALONG COASTAL SECTIONS...BUT AREAS FARTHER INLAND MAY TEND TO SEE MORE BREAKS AND LESS COVERAGE OF PRECIP AS FORCING IS EXPECTED TO REMAIN FARTHER EAST THAN PAST 2 DAYS. A BIT WARMER INLAND AS PCPN SHOULD BECOME A BIT MORE SPOTTY IN NATURE. HIGHS U70S/LOWER 80S EAST TO LWR/MID 80S ALONG/WEST OF I-95. LOWS SUN NIGHT 65-70 F WITH HIGHEST PCPN CHCS ALONG THE COAST...HAVE SCALED BACK TO ONLY 20-30% CHC POPS NW 1/2 OF THE CWA AFTER MIDNIGHT. FOR MON/TUE...GFS/ECMWF DIFFER AS TO EXTENT OF SFC TROUGHING REMAINING ALONG THE COAST...LIKELY DUE TO UNCERTAINTIES WITH RESPECT TO WHERE TC BERTHA WILL BE LOCATED. WILL RETAIN CHC POPS ALL AREAS MON BUT WILL STILL FOCUS HIGHEST POPS ALONG THE COAST. ON TUE...A LOW CONFIDENCE FORECAST AS LATEST ECMWF IS WETTER AS TROUGH STRENGTHENS AND PUSHES DEEPER MOISTURE BACK N INTO THE MID ATLC WHILE GFS IS GENLY DRY. WILL RETAIN SLIGHT CHC TO LOW CHC POPS MOST AREAS WITH HIGHS MON MAINLY IN THE MID-UPPER 80S AND HIGHS TUE 85-90 F. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... A BRIEF DRY PERIOD IS EXPECTED TUE NIGHT INTO EARLY WED AS THE MID ATLANTIC REGION SITS BTWN THE DEPARTING FRONTAL BOUNDARY AND ANOTHER APPROACHING COLD FRONT FROM THE NW. THIS FRONT IS EXPECTED TO CROSS THE AREA LATE DAY WED INTO THU MORNING...AND THEN GET STRETCHED ACROSS THE CAROLINAS LATER THU INTO FRI. SCATTERED SHOWERS/THUNDERSTORMS WILL BE POSSIBLE AREAWIDE ON WED...THEN PRECIP GETS SHUNTED SOUTH ALONG THE VA/NC BORDER AND POINTS SWD FOR THU/FRI. HIGH PRESSURE BUILDS BACK INTO THE REGION FROM THE NW LATE FRI INTO NEXT WEEKEND. HIGH TEMPERATURES WILL BE NEAR NORMAL WED (UPPER 80S TO LOWER 90S) AND THEN COOL UP TO 5 DEGREES BELOW NORMAL FOR THU-SAT (GENERALLY IN THE 80S). LOW TEMPERATURES TUE/WED NIGHTS WILL AVERAGE OUT IN THE UPPER 60S TO LOWER 70S AND THEN EXPERIENCE A SLIGHT COOL DOWN WITH LOWS GENERALLY IN THE 60S THU/FRI NIGHTS. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... A STATIONARY FRONTAL BOUNDARY WILL REMAIN INVOF SE VA AND NE NC TODAY. LIGHT TO MODERATE RAIN WILL CONTINUE TO MOVE NORTHWARD ACROSS EASTERN VA AND THE DELMARVA THRU 12Z...ESPECIALLY EAST OF INTERSTATE 95. CONDS EXPECTED TO REMAIN IFR DURING THIS TIME...EXCEPT ONLY MVFR AT KECG. FOR THE REST OF TODAY...PRECIP WILL LARGELY BE CONFINED TO FAR SE VA AND NE NC WITH SOME IMPROVEMENT IN CONDITIONS ELSEWHERE. MVFR/IFR CONDITIONS EXPECTED TONIGHT INTO MONDAY AS THE FRONTAL BOUNDARY REMAINS NEARBY. IMPROVED CONDITIONS TUESDAY AND WEDNESDAY AS THE BOUNDARY MOVES OFFSHORE. && .MARINE... A FRONTAL BOUNDARY WILL REMAIN INVOF THE MID-ATLANTIC COAST THROUGH MONDAY. NO FLAGS ARE EXPECTED AS WIND SPEEDS REMAIN GENERALLY BELOW 15 KT. SEAS 2-4 FT WITH WAVES 1-2 FT. THE FRONT GETS PULLED OFFSHORE BY TROPICAL STORM BERTHA BY TUESDAY AS IT STAYS WELL EAST OF THE OUTER BANKS...AND ALSO AS HIGH PRESSURE BUILDS INTO THE REGION FROM THE NW. SOME LONG PERIOD SWELL COULD ENCROACH THE AREA DEPENDING ON THE STRENGTH/TRACK OF TROPICAL STORM BERTHA. CURRENT WAVEWATCH GUIDANCE BRINGS 4-5 FT SWELL OUT NEAR 20 NM LATE TUESDAY/TUESDAY NIGHT. ANOTHER COLD FRONT APPROACHES FROM THE NW WEDNESDAY AND MOVES TWD THE VA/NC BORDER BY THURSDAY. OVERALL SUB- SCA CONDITIONS ARE EXPECTED TO PREVAIL THROUGH NEXT WEEK WITH THE EXCEPTION OF MINOR AFFECTS FELT BY THE PASSING OF TROPICAL STORM BERTHA. && .HYDROLOGY... PERIODIC RAINFALL ALONG A SLOW-MOVING FRONTAL BOUNDARY WILL CONTINUE TO BRING ACCUMULATING PRECIPITATION TO THE REGION TODAY THROUGH MONDAY. HIGHEST ACCUMULATIONS FOCUSED OVER NE NC AND SE VA WITH ADDNTL QPF AMTS BTWN 1.5-2.5 INCHES (LCLLY HIGHER IN TRAINING ECHOES) PRIMARILY OVER THE NEXT 24 HRS. RAISED FLOOD WATCH IN AREAS THAT HAVE GENLY RECEIVED 2-4" OVER PAST 24 HRS WHERE ADDITIONAL SIGNIFICANT RAINFALL AMOUNTS MAY RESULT IN FLOODING OF URBAN AREAS...AREAS OF POOR DRAINAGE...LOW LYING AREAS...AND TO RISES OF SMALL STREAMS/CREEKS. WILL CONTINUE TO HIGHLIGHT LOCALLY HEAVY RAINFALL POTENTIAL FOR AREAS NOT IN THE WATCH IN THE HWO. && .CLIMATE... COOL DAYTIME TEMPERATURES FOR EARLY AUGUST...COMING CLOSE TO CHALLENGING RECORDS. FOR REFERENCE...THE RECORD LOW MAXIMUM TEMPERATURES FOR TODAY/AUGUST 2ND: RICHMOND....74 F (1903). NORFOLK.....74 F (1916). SALISBURY...74 F (1959). && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...MODERATE RIP CURRENT RISK THROUGH THIS EVENING FOR MDZ025. NC...FLOOD WATCH THROUGH THIS EVENING FOR NCZ013>017-030>032-102. MODERATE RIP CURRENT RISK THROUGH THIS EVENING FOR NCZ102. VA...FLOOD WATCH THROUGH THIS EVENING FOR VAZ095>100. MODERATE RIP CURRENT RISK THROUGH THIS EVENING FOR VAZ098>100. MARINE...NONE. && $$ SYNOPSIS...ALB/LKB NEAR TERM...ALB/LKB SHORT TERM...LKB/MPR LONG TERM...BMD AVIATION...JDM MARINE...JDM HYDROLOGY...AKQ CLIMATE...AKQ
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
139 PM EDT SUN AUG 3 2014 LATEST UPDATE... AVIATION .SYNOPSIS... ISSUED AT 330 AM EDT SUN AUG 3 2014 A WEAK HIGH PRESSURE RIDGE WILL BRING FAIR WEATHER TODAY WITH SEASONABLY WARM TEMPERATURES. A WEAK COLD FRONT WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS MONDAY INTO MONDAY EVENING. A FEW SHOWERS AND STORMS WILL LINGER MAINLY NEAR TO SOUTH OF INTERSTATE 96 TUESDAY BEFORE DRY WEATHER RETURNS WEDNESDAY THROUGH THE REMAINDER OF THE WEEK. TEMPERATURES WILL AVERAGE RATHER CLOSE TO NORMAL THROUGH THE UPCOMING WEEK. && .UPDATE... ISSUED AT 1046 AM EDT SUN AUG 3 2014 BUMPED UP AFTERNOON TEMPERATURES A DEGREE OR TWO...OTHERWISE NO CHANGES ON MORNING UPDATE. LOOKING AT TOMORROW...INITIAL THINKING IS THAT THERE WILL BE A GOOD BIT OF EVENING SHOWER / THUNDERSTORM ACTIVITY SLOWLY WORKING NORTH TO SOUTH AHEAD OF DEVELOPING COLD FRONT. EXPECTING A FEW STRONG STORMS WITH HEAVY RAIN AND MICROBURST POTENTIAL ASSOCIATED WITH POORLY ORGANIZED MULITCELLS SUPPORTED BY ML CAPE AROUND 1000 J/KG AND WEAK DEEP LAYER SHEAR OF < 20 KTS. SOME MOISTURE POOLING ALONG FRONTAL BOUNDARY WITH WEAK MOIST FLUX CONVERGENCE AND MODEST UPPER DIVERGENCE AHEAD OF DIGGING SHORT WAVE WILL PROVIDE FORCING. THAT SHORTWAVE IS NOW PUSHING THROUGH SOUTHERN ALBERTA AND N MO AND LOOKS PRETTY GOOD ON WATER VAPOR IMAGERY. UPDATE ISSUED AT 604 AM EDT SUN AUG 3 2014 I HAVE UPDATED OUR GRIDS AND ZONE FORECAST TO INCLUDE AREAS OF DENSE FOG NORTH AND EAST OF US-131 AND I-96 TILL ABOUT 9 AM. THE RAP MODEL SHOWS THE LOW LEVEL FLOW HAS BEEN OFF LAKE HURON INTO CENTRAL LOWER MICHIGAN AIMED DIRECTLY INTO THE WHERE DENSE FOG HAS DEVELOPED. THE RAP MODEL VISIBILITY FORECAST...WHICH IS DOING GREAT ON THE AREA OF DENSE FOG CURRENTLY (05 AM) SHOWS IT TOTALLY MIXING OUT BY 9 AM. THAT MAKES SENSE AS THERE IS LITTLE IN THE WAY OF CLOUDS OVER THE FOG AND IT IS SHALLOW FOG TOO. AFTER COORDINATING WITH APX ON THE ISSUE WE DECIDED NOT TO ISSUE A DENSE FOG ADVISORY BUT JUST TO PUT AREAS OF DENSE FOG IN THE GRIDS AND CALL THAT GOOD. && .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 330 AM EDT SUN AUG 3 2014 OUR PRIMARY SHORT TERM FORECAST CONCERNS INVOLVE DETERMINING POTENTIAL FOR CONVECTION MONDAY THROUGH TUESDAY. A WEAK COLD FRONT WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS MONDAY INTO MONDAY NIGHT. THE BEST CHANCE FOR STORMS MONDAY WILL BE NEAR TO MAINLY EAST OF US-131 WHERE THERE WILL BE LESS OF A STABILIZING INFLUENCE FROM LAKE MI. SB CAPE VALUES WILL POTENTIALLY REACH AROUND 2000 J/KG OVER OUR EASTERN FCST AREA AS SUGGESTED BY LATEST 00Z GFS AND ECMWF GUIDANCE. HOWEVER ML CAPE VALUES MAY ONLY REACH AROUND 750 J/KG OVER OUR SE FCST AREA ACCORDING TO LATEST SREF GUIDANCE. SEVERE WEATHER IS NOT ANTICIPATED DUE TO RELATIVELY WEAK FORCING FROM THE WEAK COLD FRONT... WEAK 0-6 KM BULK SHEAR VALUES OF ONLY AROUND 15-20 KTS AND LACK OF STRONGER INSTABILITY. A CONSENSUS OF LATEST SHORT RANGE GUIDANCE SUGGESTS SCATTERED SHOWERS AND PERHAPS A FEW STORMS WILL LINGER MONDAY NIGHT AND THEN INTO TUESDAY MAINLY NEAR TO SOUTH OF I-96. HOWEVER WEAKER INSTABILITY IS ANTICIPATED TUESDAY AND IT WILL BE MORE CONFINED TO THE AREA NEAR TO SOUTH OF I-96. A WEAK HIGH PRESSURE RIDGE WILL BRING FAIR AND SEASONABLY WARM WX TODAY WITH MAX TEMPS REACHING THE LOWER TO MIDDLE 80S... EXCEPT A LITTLE COOLER RIGHT ALONG THE LAKE MI SHORELINE DUE TO SW FLOW AND THE LAKE BREEZE OFF OF RELATIVELY COLD LAKE WATERS. CANNOT COMPLETELY RULE OUT POTENTIAL FOR AN ISOLATED SHOWER NEAR OR EAST OF US-131 THIS AFTERNOON BUT THERE IS NOT ENOUGH POTENTIAL IN IT TO WARRANT INCLUSION IN THE FCST. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 335 AM EDT SUN AUG 3 2014 IT WOULD NOT BE OUT OF THE QUESTION THERE COULD BE A LINGERING SHOWER OR THUNDERSTORMS INTO EARLY WEDNESDAY BEHIND THE COLD FRONT THE PRIMARY MESSAGE FOR THIS FORECAST TIME PERIOD WEATHERWISE IS DRY. TEMPERATURES WILL ONCE AGAIN FALL BELOW NORMAL DURING THE MID WEEK PERIOD. BY THE WEEKEND EXPECT TEMPERATURES TO RISE TO ABOVE NORMAL LEVELS... BUT STILL I DO NOT SEE HIGHS IN THE 90S... MORE LIKE MID 80S HIGHS BY SATURDAY. AS I HAVE BEEN SAYING THE PAST FEW NIGHTS... THE EASTERN TROUGH FORECAST BY THE ECMWF WILL BE STRONG ENOUGH TO BRING THE POLAR JET SOUTH OF MICHIGAN ONCE AGAIN BY WEDNESDAY. WE THEN GET SHORTWAVE RIDGING TO BUILD INTO THE AREA BY SATURDAY. THAT WILL BRING THE WARMER TEMPERATURES TO THE AREA. UNLIKE THIS LAST DEEP UPPER TROUGH WHEN THE POLAR JET WAS WELL SOUTH OF MICHIGAN FOR SEVERAL DAYS... THIS TIME IT WILL BE ONLY FOR A DAY. THAT MEANS THERE WILL NOT BE ENOUGH COLD AIR ALOFT FOR AFTERNOON CONVECTION. HENCE THE DRY FORECAST FOR WEDNESDAY AFTERNOON THROUGH SATURDAY. ONE THING TO WATCH FOR... TUESDAY NIGHT WE HAVE THE JET EXIT REGION OVER SOUTHWEST MICHIGAN. THAT MAY BE ENOUGH TO SUPPORT SOME THUNDERSTORM ACTIVITY. HOWEVER AT THIS POINT IT LOOKS LIKE TO MUCH DRY AIR AT MID LEVELS. EVEN SO I HAVE LOW CHANCE POPS FOR THE SOUTHERN SECTIONS OF THE CWA TUESDAY NIGHT INTO WEDNESDAY MORNING JUST I CASE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 139 PM EDT SUN AUG 3 2014 THE FOG THAT WAS PRESENT THIS MORNING HAS DISSIPATED WITH THE SUNSHINE TODAY ALONG WITH WINDS INCREASING A BIT. WE EXPECT VFR CONDITIONS TO HOLD THROUGH THE AFTERNOON HOURS RIGHT ON THROUGH THE EVENING HOURS WITH ONLY SCT CUMULUS DEVELOPMENT EXPECTED TO TAKE SHAPE INLAND FROM LAKE MICHIGAN. WE EXPECT THAT CONVECTION WILL REMAIN WEST OF LAKE MICHIGAN IN WI...AND EAST OF OUR TERMINALS. WE DO EXPECT FOG TO BECOME POSSIBLE ONCE AGAIN TONIGHT WITH LIGHT WINDS EXPECTED AT THE SFC AND A SLIGHTLY MOIST AIR MASS IN PLACE. MVFR CONDITIONS ARE A GOOD BET WITH SOME IFR POSSIBLE. THERE IS A VERY SLIGHT CHC OF A SHOWER OR STORM LATE IN THE NIGHT...HOWEVER WE FEEL THAT CONVECTION SHOULD HOLD OFF UNTIL MON AFTERNOON NORTH AND ALMOST MON EVENING SOUTH AWAY FROM THE LAKE AS A FRONT DROPS DOWN INTO THE AREA. && .MARINE... ISSUED AT 1046 AM EDT SUN AUG 3 2014 CONTINUE TO SEE SOME FOG...MAY INCREASE IN COVERAGE AND DENSITY OVERNIGHT TONIGHT AS AIRMASS MOISTENS FURTHER AHEAD OF NEXT COLD FRONT. FOG MAY CONTINUE TO BE A THREAT UNTIL TUE AFTERNOON WHEN DRIER AIR WORKS INTO THE AREA. NO WIND OR WAVE ISSUES IN THE && .HYDROLOGY... ISSUED AT 306 PM EDT SAT AUG 2 2014 NO HYDRO ISSUES DUE TO A FAIRLY DRY WEATHER PATTERN. BRIEF PERIODS OF LOCALLY HEAVY RAINFALL ARE POSSIBLE THIS EVENING IN SCATTERED THUNDERSTORMS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ UPDATE...COBB SYNOPSIS...LAURENS SHORT TERM...LAURENS LONG TERM...WDM AVIATION...NJJ HYDROLOGY...93 MARINE...COBB
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1101 AM EDT SUN AUG 3 2014 LATEST UPDATE... UPDATE/MARINE .SYNOPSIS... ISSUED AT 330 AM EDT SUN AUG 3 2014 A WEAK HIGH PRESSURE RIDGE WILL BRING FAIR WEATHER TODAY WITH SEASONABLY WARM TEMPERATURES. A WEAK COLD FRONT WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS MONDAY INTO MONDAY EVENING. A FEW SHOWERS AND STORMS WILL LINGER MAINLY NEAR TO SOUTH OF INTERSTATE 96 TUESDAY BEFORE DRY WEATHER RETURNS WEDNESDAY THROUGH THE REMAINDER OF THE WEEK. TEMPERATURES WILL AVERAGE RATHER CLOSE TO NORMAL THROUGH THE UPCOMING WEEK. && .UPDATE... ISSUED AT 1046 AM EDT SUN AUG 3 2014 BUMPED UP AFTERNOON TEMPERATURES A DEGREE OR TWO...OTHERWISE NO CHANGES ON MORNING UPDATE. LOOKING AT TOMORROW...INITIAL THINKING IS THAT THERE WILL BE A GOOD BIT OF EVENING SHOWER / THUNDERSTORM ACTIVITY SLOWLY WORKING NORTH TO SOUTH AHEAD OF DEVELOPING COLD FRONT. EXPECTING A FEW STRONG STORMS WITH HEAVY RAIN AND MICROBURST POTENTIAL ASSOCIATED WITH POORLY ORGANIZED MULITCELLS SUPPORTED BY ML CAPE AROUND 1000 J/KG AND WEAK DEEP LAYER SHEAR OF < 20 KTS. SOME MOISTURE POOLING ALONG FRONTAL BOUNDARY WITH WEAK MOIST FLUX CONVERGENCE AND MODEST UPPER DIVERGENCE AHEAD OF DIGGING SHORT WAVE WILL PROVIDE FORCING. THAT SHORTWAVE IS NOW PUSHING THROUGH SOUTHERN ALBERTA AND N MO AND LOOKS PRETTY GOOD ON WATER VAPOR IMAGERY. UPDATE ISSUED AT 604 AM EDT SUN AUG 3 2014 I HAVE UPDATED OUR GRIDS AND ZONE FORECAST TO INCLUDE AREAS OF DENSE FOG NORTH AND EAST OF US-131 AND I-96 TILL ABOUT 9 AM. THE RAP MODEL SHOWS THE LOW LEVEL FLOW HAS BEEN OFF LAKE HURON INTO CENTRAL LOWER MICHIGAN AIMED DIRECTLY INTO THE WHERE DENSE FOG HAS DEVELOPED. THE RAP MODEL VISIBILITY FORECAST...WHICH IS DOING GREAT ON THE AREA OF DENSE FOG CURRENTLY (05 AM) SHOWS IT TOTALLY MIXING OUT BY 9 AM. THAT MAKES SENSE AS THERE IS LITTLE IN THE WAY OF CLOUDS OVER THE FOG AND IT IS SHALLOW FOG TOO. AFTER COORDINATING WITH APX ON THE ISSUE WE DECIDED NOT TO ISSUE A DENSE FOG ADVISORY BUT JUST TO PUT AREAS OF DENSE FOG IN THE GRIDS AND CALL THAT GOOD. && .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 330 AM EDT SUN AUG 3 2014 OUR PRIMARY SHORT TERM FORECAST CONCERNS INVOLVE DETERMINING POTENTIAL FOR CONVECTION MONDAY THROUGH TUESDAY. A WEAK COLD FRONT WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS MONDAY INTO MONDAY NIGHT. THE BEST CHANCE FOR STORMS MONDAY WILL BE NEAR TO MAINLY EAST OF US-131 WHERE THERE WILL BE LESS OF A STABILIZING INFLUENCE FROM LAKE MI. SB CAPE VALUES WILL POTENTIALLY REACH AROUND 2000 J/KG OVER OUR EASTERN FCST AREA AS SUGGESTED BY LATEST 00Z GFS AND ECMWF GUIDANCE. HOWEVER ML CAPE VALUES MAY ONLY REACH AROUND 750 J/KG OVER OUR SE FCST AREA ACCORDING TO LATEST SREF GUIDANCE. SEVERE WEATHER IS NOT ANTICIPATED DUE TO RELATIVELY WEAK FORCING FROM THE WEAK COLD FRONT... WEAK 0-6 KM BULK SHEAR VALUES OF ONLY AROUND 15-20 KTS AND LACK OF STRONGER INSTABILITY. A CONSENSUS OF LATEST SHORT RANGE GUIDANCE SUGGESTS SCATTERED SHOWERS AND PERHAPS A FEW STORMS WILL LINGER MONDAY NIGHT AND THEN INTO TUESDAY MAINLY NEAR TO SOUTH OF I-96. HOWEVER WEAKER INSTABILITY IS ANTICIPATED TUESDAY AND IT WILL BE MORE CONFINED TO THE AREA NEAR TO SOUTH OF I-96. A WEAK HIGH PRESSURE RIDGE WILL BRING FAIR AND SEASONABLY WARM WX TODAY WITH MAX TEMPS REACHING THE LOWER TO MIDDLE 80S... EXCEPT A LITTLE COOLER RIGHT ALONG THE LAKE MI SHORELINE DUE TO SW FLOW AND THE LAKE BREEZE OFF OF RELATIVELY COLD LAKE WATERS. CANNOT COMPLETELY RULE OUT POTENTIAL FOR AN ISOLATED SHOWER NEAR OR EAST OF US-131 THIS AFTERNOON BUT THERE IS NOT ENOUGH POTENTIAL IN IT TO WARRANT INCLUSION IN THE FCST. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 335 AM EDT SUN AUG 3 2014 IT WOULD NOT BE OUT OF THE QUESTION THERE COULD BE A LINGERING SHOWER OR THUNDERSTORMS INTO EARLY WEDNESDAY BEHIND THE COLD FRONT THE PRIMARY MESSAGE FOR THIS FORECAST TIME PERIOD WEATHERWISE IS DRY. TEMPERATURES WILL ONCE AGAIN FALL BELOW NORMAL DURING THE MID WEEK PERIOD. BY THE WEEKEND EXPECT TEMPERATURES TO RISE TO ABOVE NORMAL LEVELS... BUT STILL I DO NOT SEE HIGHS IN THE 90S... MORE LIKE MID 80S HIGHS BY SATURDAY. AS I HAVE BEEN SAYING THE PAST FEW NIGHTS... THE EASTERN TROUGH FORECAST BY THE ECMWF WILL BE STRONG ENOUGH TO BRING THE POLAR JET SOUTH OF MICHIGAN ONCE AGAIN BY WEDNESDAY. WE THEN GET SHORTWAVE RIDGING TO BUILD INTO THE AREA BY SATURDAY. THAT WILL BRING THE WARMER TEMPERATURES TO THE AREA. UNLIKE THIS LAST DEEP UPPER TROUGH WHEN THE POLAR JET WAS WELL SOUTH OF MICHIGAN FOR SEVERAL DAYS... THIS TIME IT WILL BE ONLY FOR A DAY. THAT MEANS THERE WILL NOT BE ENOUGH COLD AIR ALOFT FOR AFTERNOON CONVECTION. HENCE THE DRY FORECAST FOR WEDNESDAY AFTERNOON THROUGH SATURDAY. ONE THING TO WATCH FOR... TUESDAY NIGHT WE HAVE THE JET EXIT REGION OVER SOUTHWEST MICHIGAN. THAT MAY BE ENOUGH TO SUPPORT SOME THUNDERSTORM ACTIVITY. HOWEVER AT THIS POINT IT LOOKS LIKE TO MUCH DRY AIR AT MID LEVELS. EVEN SO I HAVE LOW CHANCE POPS FOR THE SOUTHERN SECTIONS OF THE CWA TUESDAY NIGHT INTO WEDNESDAY MORNING JUST I CASE. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 742 AM EDT SUN AUG 3 2014 ANY AREAS OF FOG WILL LIFT OUT QUICKLY THIS MORNING WITH STRONG AUGUST SUNSHINE AND THE FOG BEING OF A SHALLOW NATURE. THEN VFR CONDITIONS WILL PREVAIL THROUGH THE DAY TIME INTO THIS EVENING. DURING THE EARLY MORNING HOURS OF MONDAY...I EXPECT AND AREA OF SHOWERS AND THUNDERSTORMS TO MOVE SOUTH SOUTHEAST AS THE WARMER AND MORE MOIST AIR ARRIVES AT MID AND HIGH LEVELS. THE CHANCES OF SEEING SUCH A STORM IS BEST CLOSER TO THE LAKE SHORE. I EXPECT MVFR FOG MONDAY MORNING AS HIGHER DEW POINT AIR MOVES INTO THE AREA FROM THE SOUTH. && .MARINE... ISSUED AT 1046 AM EDT SUN AUG 3 2014 CONTINUE TO SEE SOME FOG...MAY INCREASE IN COVERAGE AND DENSITY OVERNIGHT TONIGHT AS AIRMASS MOISTENS FURTHER AHEAD OF NEXT COLD FRONT. FOG MAY CONTINUE TO BE A THREAT UNTIL TUE AFTERNOON WHEN DRIER AIR WORKS INTO THE AREA. NO WIND OR WAVE ISSUES IN THE FORESEABLE FUTURE. && .HYDROLOGY... ISSUED AT 306 PM EDT SAT AUG 2 2014 NO HYDRO ISSUES DUE TO A FAIRLY DRY WEATHER PATTERN. BRIEF PERIODS OF LOCALLY HEAVY RAINFALL ARE POSSIBLE THIS EVENING IN SCATTERED THUNDERSTORMS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ UPDATE...COBB SYNOPSIS...LAURENS SHORT TERM...LAURENS LONG TERM...WDM AVIATION...WDM HYDROLOGY...93 MARINE...COBB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1010 AM EDT SUN AUG 3 2014 .UPDATE... ISSUED AT 1009 AM EDT SUN AUG 3 2014 NO MAJOR CHANGES TO THE FORECAST PLANNED. LATEST SFC AND OBJECTIVE DATA SUGGESTS THAT THE SFC FRONT AT 14Z EXTENDS FROM WAWA ONTARIO THROUGH MARQUETTE TO IRONWOOD. THE FRONT LIKELY SURGED ACROSS THE COLD LAKE AND WILL NOW SLOW DOWN DUE TO THE HEATING OF THE LANDMASS OVER UPPER MI. LATEST OBSERVATIONS ALSO SHOW POOLING OF HIGHER SFC DEW POINTS ALONG THE FRONT WITH DWPTS IN THE LOWER 60S ACROSS NRN WI AND SRN UPPER MI. WITH THAT SAID...THE EXPECTATION OF SHOWERS AND THUNDERSTORMS DEVELOPING LATER THIS MORNING INTO THIS AFTERNOON ALONG JUST INLAND OF LAKE SUPERIOR ACROSS THE EASTERN HALF OF THE FORECAST AREA STILL SEEMS REASONABLE. THE CONVECTION BEARING HI RES NWP ARE IN FAIRLY GOOD AGREEMENT IN THIS OCCURRING BY 18Z...WITH BROKEN THUNDERSTORMS EXTENDING ALONG THE LAKE BREEZE BOUNDARIES FROM NEGAUNEE THROUGH CHATHAM TO SENEY AND NEWBERRY. DESPITE FORECAST MLCAPE VALUES OF 1000 J/KG...DUE TO RELATIVELY WEAK MID LEVEL LAPSE RATES OF ONLY 6-6.25C/KM...IT SEEMS UNLIKELY THAT SEVERE WEATHER WILL DEVELOP. HOWEVER...THE MODEL SOUNDINGS DO SUGGEST SOME DRYING IN THE LOWER LEVELS WHICH MAY PERHAPS SUGGEST A MINOR WIND GUST THREAT WITH ANY STORM. MOST LIKELY...ANY STRONGER STORM MAY SEE SOME GUSTY WINDS OF 30-40 MPH AND SMALL HAIL DUE TO THE RELATIVELY LOW WET BULB ZERO LEVELS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 351 AM EDT SUN AUG 3 2014 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NW FLOW OVER THE UPR LKS BTWN TROF CENTERED OVER QUEBEC AND MEAN RDG OVER THE ROCKIES. DESPITE SHARP MID LVL INVRN/VERY DRY MID LVLS SHOWN ON THE 00Z GRB RAOB ASSOCIATED WITH SHRTWV RDG PASSING THRU THE UPR LKS THAT IS BRINGING MOCLR CONDITIONS TO UPR MI...THERE ARE SOME ISOLD SHOWERS OVER WI AND FAR WRN UPR MI IN ADVANCE OF A SHRTWV DROPPING SEWD THRU SRN MN. A STRONGER SHRTWV EMBEDDED IN THE NW FLOW ALF IS MOVING ESEWD THRU NW ONTARIO...WITH ATTENDANT RATHER WEAK SFC-H85 COLD FNT MOVING INTO NRN MN. THERE WERE SOME SHOWERS/TS LAST EVNG OVER FARN NRN MN/ADJOINING ONTARIO IN ADVANCE OF THIS FNT IN THE FAIRLY MOIST ENVIRONMENT DEPICTED ON THE 00Z INL RAOB /00Z PWAT WAS 1.25 INCH OR ALMOST 150 PCT OF NORMAL AND KINX WAS 32/...BUT LOSS OF DAYTIME HEATING...PASSAGE OF SHARPER FORCING TO THE N AND ABSENCE OF SGNFT H85-7 MSTR INFLOW NECESSARY TO SUSTAIN NOCTURNAL CONVECTION HAVE CAUSED THESE SHOWERS TO DIMINISH ALMOST ENTIRELY EARLY THIS MRNG IN AN ENVIRONMENT WHERE MUCAPE IS 100-250 J/KG AT BEST. MAIN FCST CONCERNS THRU TNGT ARE FOCUSED ON POPS ASSOCIATED WITH APRCHG COLD FNT. TODAY...SHRTWV OVER ONTARIO IS PROGGED TO CONTINUE ESEWD...WITH ATTENDANT SFC COLD FNT ON A LINE THRU NW LK SUP AT 12Z THIS MRNG FCST TO REACH THE SE CWA BY LATE THIS AFTN. WL CARRY ONLY ISOLD SHOWERS THIS MRNG OVER THE NW CWA ASSOCIATED WITH THE FROPA GIVEN PRESENT COVERAGE ALONG THE FNT AND PASSAGE OF SHARPER FORCING TO THE N. BUT AS THE FNT/MID LVL COMMA TAIL MSTR RIBBON PRESSES TO THE SE THIS AFTN IN THE PRESENCE OF DAYTIME HEATING...EXPECT THE SHOWER/TS COVERAGE TO INCRS. INTERACTION BTWN THE FNT AND LK BREEZE BNDRYS THAT WL SHARPEN THE LLVL CNVGC WL ALSO AID THE CONVECTION. BOTH THE 00Z NAM/LOCAL WRF-ARW MODELS INDICATE THE LI WL DROP AS LO AS -6 TO -8C AS MUCAPES REACH ARND 2500 J/KG THIS AFTN OVER THE SCNTRL CWA... JUSTIFYING THE GOING LIKELY POPS IN THE CURRENT FCST FOR THAT AREA THIS AFTN. WITH SFC-6KM BULK SHEAR AS HI AS 30 KTS...THERE COULD BE SOME STRONGER CELLS. WITH SFC TEMPS RISING TO 80-85 AHEAD OF THE FNT RESULTING IN ADIABATIC LAPSE RATES IN THE PBL...GUSTY WINDS SHOULD BE THE MAIN THREAT. BUT MARGINAL LAPSE RATES AND SHEAR INDICATE SVR WX IS NOT LIKELY. TNGT...ARRIVAL OF SOME DRYING ALF FOLLOWING THE FROPA AND LOSS OF DAYTIME HEATING SHOULD RESULT IN LINGERING POPS OVER THE SE CWA DIMINISHING THIS EVNG. BUT SINCE SEVERAL MODELS SHOW ANOTHER WEAKER SHRTWV DROPPING SEWD IN THE NW FLOW ALF AND ASSOCIATED DPVA/DEEP LYR QVECTOR CNVGC IMPACTING THE CWA OVERNGT...WL RETAIN SOME LOWER CHC POPS MAINLY OVER THE SRN TIER CLOSER TO THE HIER LINGERING PWAT AOA AN INCH. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 351 AM EDT SUN AUG 3 2014 GENERALLY QUIET WEATHER EXPECTED THROUGH THE EXTENDED WITH DRY WEATHER AND MODERATING TEMPERATURES EXPECTED. ISOLATED SHOWERS AND THUNDERSTORMS ARE POSSIBLE NEAR THE WISCONSIN BORDER DURING THE DAY MONDAY AS A SHORTWAVE PASSES THROUGH THE BROAD TROUGHING STILL IN PLACE OVER MUCH OF THE EASTERN U.S. THE BETTER FORCING AN MOISTURE IS EXPECTED TO REMAIN MAINLY SOUTH OF THE REGION AS THE VORT MAX SWINGS THROUGH...HOWEVER...IT WILL BRUSH CLOSE ENOUGH TO THE U.P./WI BORDER TO KEEP SLIGHT POPS IN THE FORECAST. ANOTHER SHORTWAVE IS PROGGED TO ROTATE AROUND THE TROUGH TUESDAY NIGHT...HOWEVER...CONDITIONS WILL REMAIN DRY AS THIS WILL SWING THROUGH DURING THE COOLER OVERNIGHT HOURS WITH VERY LIMITED MOISTURE AVAILABLE DURING THAT TIME. THE REMAINDER OF THE EXTENDED...WEDNESDAY THROUGH SATURDAY WILL BE DOMINATED BY BROAD SURFACE HIGH PRESSURE ALONG WITH UPPER LEVEL 500MB RIDGING SLIDING FROM THE WESTERN U.S. INTO THE CENTRAL U.S. THIS WILL ALLOW TEMPERATURES TO WARM TO NEAR OR SLIGHTLY ABOVE NORMAL BY THE END OF THE WORK WEEK AND INTO THE UPCOMING WEEKEND. CONDITIONS WILL REMAIN DRY AS DRY AIR REMAINS IN PLACE ACROSS THE GREAT LAKES REGION THROUGH THIS TIME PERIOD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 724 AM EDT SUN AUG 3 2014 EXPECT ANY LINGERING FOG AT IWD/SAW TO BURN OFF QUICKLY THIS MRNG. A COLD FNT PUSHING ACRS UPR MI TDAY MAY BRING SOME -SHRA/TS TO MAINLY SAW THIS AFTN. RIGHT NOW...IT APPEARS THE FROPA WL OCCUR TOO EARLY AT IWD AND CMX TO ALLOW FOR ANY SHOWERS AT THOSE SITES. ALTHOUGH VFR CONDITIONS WL PREDOMINATE TDAY AND THIS EVNG...LINGERING LLVL MSTR BLO SOME MID LVL DRYING SHOULD ALLOW FOR MORE FOG FORMATION TNGT AS WINDS WL BE LGT. IFR CONDITIONS ARE A GOOD POSSIBILITY...ESPECIALLY AT CMX AND IWD...WHERE THE MID LVL DRYING WL BE MOST PRONOUNCED. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 351 AM EDT SUN AUG 3 2014 TYPICAL SUMMER TYPE FLOW REGIME/WEAK PRES GRADIENT WILL KEEP WINDS UNDER 15 KT THROUGH MUCH OF THIS COMING WEEK. SOME PATCHY FOG IS POSSIBLE INTO MON...ESPECIALLY IF RAIN FALLS TODAY. BUT ANY WIDESPREAD DENSE FOG IS UNLIKELY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ UPDATE...MRD SHORT TERM...KC LONG TERM...KEC AVIATION...KC MARINE...KC
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
742 AM EDT SUN AUG 3 2014 LATEST UPDATE... AVIATION .SYNOPSIS... ISSUED AT 330 AM EDT SUN AUG 3 2014 A WEAK HIGH PRESSURE RIDGE WILL BRING FAIR WEATHER TODAY WITH SEASONABLY WARM TEMPERATURES. A WEAK COLD FRONT WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS MONDAY INTO MONDAY EVENING. A FEW SHOWERS AND STORMS WILL LINGER MAINLY NEAR TO SOUTH OF INTERSTATE 96 TUESDAY BEFORE DRY WEATHER RETURNS WEDNESDAY THROUGH THE REMAINDER OF THE WEEK. TEMPERATURES WILL AVERAGE RATHER CLOSE TO NORMAL THROUGH THE UPCOMING WEEK. && .UPDATE... ISSUED AT 604 AM EDT SUN AUG 3 2014 I HAVE UPDATED OUR GRIDS AND ZONE FORECAST TO INCLUDE AREAS OF DENSE FOG NORTH AND EAST OF US-131 AND I-96 TILL ABOUT 9 AM. THE RAP MODEL SHOWS THE LOW LEVEL FLOW HAS BEEN OFF LAKE HURON INTO CENTRAL LOWER MICHIGAN AIMED DIRECTLY INTO THE WHERE DENSE FOG HAS DEVELOPED. THE RAP MODEL VISIBILITY FORECAST...WHICH IS DOING GREAT ON THE AREA OF DENSE FOG CURRENTLY (05 AM) SHOWS IT TOTALLY MIXING OUT BY 9 AM. THAT MAKES SENSE AS THERE IS LITTLE IN THE WAY OF CLOUDS OVER THE FOG AND IT IS SHALLOW FOG TOO. AFTER COORDINATING WITH APX ON THE ISSUE WE DECIDED NOT TO ISSUE A DENSE FOG ADVISORY BUT JUST TO PUT AREAS OF DENSE FOG IN THE GRIDS AND CALL THAT GOOD. && .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 330 AM EDT SUN AUG 3 2014 OUR PRIMARY SHORT TERM FORECAST CONCERNS INVOLVE DETERMINING POTENTIAL FOR CONVECTION MONDAY THROUGH TUESDAY. A WEAK COLD FRONT WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS MONDAY INTO MONDAY NIGHT. THE BEST CHANCE FOR STORMS MONDAY WILL BE NEAR TO MAINLY EAST OF US-131 WHERE THERE WILL BE LESS OF A STABILIZING INFLUENCE FROM LAKE MI. SB CAPE VALUES WILL POTENTIALLY REACH AROUND 2000 J/KG OVER OUR EASTERN FCST AREA AS SUGGESTED BY LATEST 00Z GFS AND ECMWF GUIDANCE. HOWEVER ML CAPE VALUES MAY ONLY REACH AROUND 750 J/KG OVER OUR SE FCST AREA ACCORDING TO LATEST SREF GUIDANCE. SEVERE WEATHER IS NOT ANTICIPATED DUE TO RELATIVELY WEAK FORCING FROM THE WEAK COLD FRONT... WEAK 0-6 KM BULK SHEAR VALUES OF ONLY AROUND 15-20 KTS AND LACK OF STRONGER INSTABILITY. A CONSENSUS OF LATEST SHORT RANGE GUIDANCE SUGGESTS SCATTERED SHOWERS AND PERHAPS A FEW STORMS WILL LINGER MONDAY NIGHT AND THEN INTO TUESDAY MAINLY NEAR TO SOUTH OF I-96. HOWEVER WEAKER INSTABILITY IS ANTICIPATED TUESDAY AND IT WILL BE MORE CONFINED TO THE AREA NEAR TO SOUTH OF I-96. A WEAK HIGH PRESSURE RIDGE WILL BRING FAIR AND SEASONABLY WARM WX TODAY WITH MAX TEMPS REACHING THE LOWER TO MIDDLE 80S... EXCEPT A LITTLE COOLER RIGHT ALONG THE LAKE MI SHORELINE DUE TO SW FLOW AND THE LAKE BREEZE OFF OF RELATIVELY COLD LAKE WATERS. CANNOT COMPLETELY RULE OUT POTENTIAL FOR AN ISOLATED SHOWER NEAR OR EAST OF US-131 THIS AFTERNOON BUT THERE IS NOT ENOUGH POTENTIAL IN IT TO WARRANT INCLUSION IN THE FCST. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 335 AM EDT SUN AUG 3 2014 IT WOULD NOT BE OUT OF THE QUESTION THERE COULD BE A LINGERING SHOWER OR THUNDERSTORMS INTO EARLY WEDNESDAY BEHIND THE COLD FRONT THE PRIMARY MESSAGE FOR THIS FORECAST TIME PERIOD WEATHERWISE IS DRY. TEMPERATURES WILL ONCE AGAIN FALL BELOW NORMAL DURING THE MID WEEK PERIOD. BY THE WEEKEND EXPECT TEMPERATURES TO RISE TO ABOVE NORMAL LEVELS... BUT STILL I DO NOT SEE HIGHS IN THE 90S... MORE LIKE MID 80S HIGHS BY SATURDAY. AS I HAVE BEEN SAYING THE PAST FEW NIGHTS... THE EASTERN TROUGH FORECAST BY THE ECMWF WILL BE STRONG ENOUGH TO BRING THE POLAR JET SOUTH OF MICHIGAN ONCE AGAIN BY WEDNESDAY. WE THEN GET SHORTWAVE RIDGING TO BUILD INTO THE AREA BY SATURDAY. THAT WILL BRING THE WARMER TEMPERATURES TO THE AREA. UNLIKE THIS LAST DEEP UPPER TROUGH WHEN THE POLAR JET WAS WELL SOUTH OF MICHIGAN FOR SEVERAL DAYS... THIS TIME IT WILL BE ONLY FOR A DAY. THAT MEANS THERE WILL NOT BE ENOUGH COLD AIR ALOFT FOR AFTERNOON CONVECTION. HENCE THE DRY FORECAST FOR WEDNESDAY AFTERNOON THROUGH SATURDAY. ONE THING TO WATCH FOR... TUESDAY NIGHT WE HAVE THE JET EXIT REGION OVER SOUTHWEST MICHIGAN. THAT MAY BE ENOUGH TO SUPPORT SOME THUNDERSTORM ACTIVITY. HOWEVER AT THIS POINT IT LOOKS LIKE TO MUCH DRY AIR AT MID LEVELS. EVEN SO I HAVE LOW CHANCE POPS FOR THE SOUTHERN SECTIONS OF THE CWA TUESDAY NIGHT INTO WEDNESDAY MORNING JUST I CASE. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 742 AM EDT SUN AUG 3 2014 ANY AREAS OF FOG WILL LIFT OUT QUICKLY THIS MORNING WITH STRONG AUGUST SUNSHINE AND THE FOG BEING OF A SHALLOW NATURE. THEN VFR CONDITIONS WILL PREVAIL THROUGH THE DAY TIME INTO THIS EVENING. DURING THE EARLY MORNING HOURS OF MONDAY...I EXPECT AND AREA OF SHOWERS AND THUNDERSTORMS TO MOVE SOUTH SOUTHEAST AS THE WARMER AND MORE MOIST AIR ARRIVES AT MID AND HIGH LEVELS. THE CHANCES OF SEEING SUCH A STORM IS BEST CLOSER TO THE LAKE SHORE. I EXPECT MVFR FOG MONDAY MORNING AS HIGHER DEW POINT AIR MOVES INTO THE AREA FROM THE SOUTH. && .MARINE... ISSUED AT 330 AM EDT SUN AUG 3 2014 A WEAK PRESSURE GRADIENT WILL CONTINUE TO RESULT IN FAIRLY MINIMAL WIND AND WAVE ACTION THE NEXT COUPLE OF DAYS WITH WAVE HEIGHTS UNDER TWO FEET. HOWEVER SOME PATCHY FOG THAT MAY BE DENSE AT TIMES IS ANTICIPATED THAT WILL CONTINUE TO POSE A HAZARD TO MARINERS DUE TO RELATIVELY COLD LAKE WATERS AND HIGHER DEW POINT AIR JUST ABOVE THE LAKE SURFACE. && .HYDROLOGY... ISSUED AT 306 PM EDT SAT AUG 2 2014 NO HYDRO ISSUES DUE TO A FAIRLY DRY WEATHER PATTERN. BRIEF PERIODS OF LOCALLY HEAVY RAINFALL ARE POSSIBLE THIS EVENING IN SCATTERED THUNDERSTORMS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ UPDATE...WDM SYNOPSIS...LAURENS SHORT TERM...LAURENS LONG TERM...WDM AVIATION...WDM HYDROLOGY...93 MARINE...LAURENS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
725 AM EDT SUN AUG 3 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 351 AM EDT SUN AUG 3 2014 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NW FLOW OVER THE UPR LKS BTWN TROF CENTERED OVER QUEBEC AND MEAN RDG OVER THE ROCKIES. DESPITE SHARP MID LVL INVRN/VERY DRY MID LVLS SHOWN ON THE 00Z GRB RAOB ASSOCIATED WITH SHRTWV RDG PASSING THRU THE UPR LKS THAT IS BRINGING MOCLR CONDITIONS TO UPR MI...THERE ARE SOME ISOLD SHOWERS OVER WI AND FAR WRN UPR MI IN ADVANCE OF A SHRTWV DROPPING SEWD THRU SRN MN. A STRONGER SHRTWV EMBEDDED IN THE NW FLOW ALF IS MOVING ESEWD THRU NW ONTARIO...WITH ATTENDANT RATHER WEAK SFC-H85 COLD FNT MOVING INTO NRN MN. THERE WERE SOME SHOWERS/TS LAST EVNG OVER FARN NRN MN/ADJOINING ONTARIO IN ADVANCE OF THIS FNT IN THE FAIRLY MOIST ENVIRONMENT DEPICTED ON THE 00Z INL RAOB /00Z PWAT WAS 1.25 INCH OR ALMOST 150 PCT OF NORMAL AND KINX WAS 32/...BUT LOSS OF DAYTIME HEATING...PASSAGE OF SHARPER FORCING TO THE N AND ABSENCE OF SGNFT H85-7 MSTR INFLOW NECESSARY TO SUSTAIN NOCTURNAL CONVECTION HAVE CAUSED THESE SHOWERS TO DIMINISH ALMOST ENTIRELY EARLY THIS MRNG IN AN ENVIRONMENT WHERE MUCAPE IS 100-250 J/KG AT BEST. MAIN FCST CONCERNS THRU TNGT ARE FOCUSED ON POPS ASSOCIATED WITH APRCHG COLD FNT. TODAY...SHRTWV OVER ONTARIO IS PROGGED TO CONTINUE ESEWD...WITH ATTENDANT SFC COLD FNT ON A LINE THRU NW LK SUP AT 12Z THIS MRNG FCST TO REACH THE SE CWA BY LATE THIS AFTN. WL CARRY ONLY ISOLD SHOWERS THIS MRNG OVER THE NW CWA ASSOCIATED WITH THE FROPA GIVEN PRESENT COVERAGE ALONG THE FNT AND PASSAGE OF SHARPER FORCING TO THE N. BUT AS THE FNT/MID LVL COMMA TAIL MSTR RIBBON PRESSES TO THE SE THIS AFTN IN THE PRESENCE OF DAYTIME HEATING...EXPECT THE SHOWER/TS COVERAGE TO INCRS. INTERACTION BTWN THE FNT AND LK BREEZE BNDRYS THAT WL SHARPEN THE LLVL CNVGC WL ALSO AID THE CONVECTION. BOTH THE 00Z NAM/LOCAL WRF-ARW MODELS INDICATE THE LI WL DROP AS LO AS -6 TO -8C AS MUCAPES REACH ARND 2500 J/KG THIS AFTN OVER THE SCNTRL CWA... JUSTIFYING THE GOING LIKELY POPS IN THE CURRENT FCST FOR THAT AREA THIS AFTN. WITH SFC-6KM BULK SHEAR AS HI AS 30 KTS...THERE COULD BE SOME STRONGER CELLS. WITH SFC TEMPS RISING TO 80-85 AHEAD OF THE FNT RESULTING IN ADIABATIC LAPSE RATES IN THE PBL...GUSTY WINDS SHOULD BE THE MAIN THREAT. BUT MARGINAL LAPSE RATES AND SHEAR INDICATE SVR WX IS NOT LIKELY. TNGT...ARRIVAL OF SOME DRYING ALF FOLLOWING THE FROPA AND LOSS OF DAYTIME HEATING SHOULD RESULT IN LINGERING POPS OVER THE SE CWA DIMINISHING THIS EVNG. BUT SINCE SEVERAL MODELS SHOW ANOTHER WEAKER SHRTWV DROPPING SEWD IN THE NW FLOW ALF AND ASSOCIATED DPVA/DEEP LYR QVECTOR CNVGC IMPACTING THE CWA OVERNGT...WL RETAIN SOME LOWER CHC POPS MAINLY OVER THE SRN TIER CLOSER TO THE HIER LINGERING PWAT AOA AN INCH. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 351 AM EDT SUN AUG 3 2014 GENERALLY QUIET WEATHER EXPECTED THROUGH THE EXTENDED WITH DRY WEATHER AND MODERATING TEMPERATURES EXPECTED. ISOLATED SHOWERS AND THUNDERSTORMS ARE POSSIBLE NEAR THE WISCONSIN BORDER DURING THE DAY MONDAY AS A SHORTWAVE PASSES THROUGH THE BROAD TROUGHING STILL IN PLACE OVER MUCH OF THE EASTERN U.S. THE BETTER FORCING AN MOISTURE IS EXPECTED TO REMAIN MAINLY SOUTH OF THE REGION AS THE VORT MAX SWINGS THROUGH...HOWEVER...IT WILL BRUSH CLOSE ENOUGH TO THE U.P./WI BORDER TO KEEP SLIGHT POPS IN THE FORECAST. ANOTHER SHORTWAVE IS PROGGED TO ROTATE AROUND THE TROUGH TUESDAY NIGHT...HOWEVER...CONDITIONS WILL REMAIN DRY AS THIS WILL SWING THROUGH DURING THE COOLER OVERNIGHT HOURS WITH VERY LIMITED MOISTURE AVAILABLE DURING THAT TIME. THE REMAINDER OF THE EXTENDED...WEDNESDAY THROUGH SATURDAY WILL BE DOMINATED BY BROAD SURFACE HIGH PRESSURE ALONG WITH UPPER LEVEL 500MB RIDGING SLIDING FROM THE WESTERN U.S. INTO THE CENTRAL U.S. THIS WILL ALLOW TEMPERATURES TO WARM TO NEAR OR SLIGHTLY ABOVE NORMAL BY THE END OF THE WORK WEEK AND INTO THE UPCOMING WEEKEND. CONDITIONS WILL REMAIN DRY AS DRY AIR REMAINS IN PLACE ACROSS THE GREAT LAKES REGION THROUGH THIS TIME PERIOD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 724 AM EDT SUN AUG 3 2014 EXPECT ANY LINGERING FOG AT IWD/SAW TO BURN OFF QUICKLY THIS MRNG. A COLD FNT PUSHING ACRS UPR MI TDAY MAY BRING SOME -SHRA/TS TO MAINLY SAW THIS AFTN. RIGHT NOW...IT APPEARS THE FROPA WL OCCUR TOO EARLY AT IWD AND CMX TO ALLOW FOR ANY SHOWERS AT THOSE SITES. ALTHOUGH VFR CONDITIONS WL PREDOMINATE TDAY AND THIS EVNG...LINGERING LLVL MSTR BLO SOME MID LVL DRYING SHOULD ALLOW FOR MORE FOG FORMATION TNGT AS WINDS WL BE LGT. IFR CONDITIONS ARE A GOOD POSSIBILITY...ESPECIALLY AT CMX AND IWD...WHERE THE MID LVL DRYING WL BE MOST PRONOUNCED. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 351 AM EDT SUN AUG 3 2014 TYPICAL SUMMER TYPE FLOW REGIME/WEAK PRES GRADIENT WILL KEEP WINDS UNDER 15 KT THROUGH MUCH OF THIS COMING WEEK. SOME PATCHY FOG IS POSSIBLE INTO MON...ESPECIALLY IF RAIN FALLS TODAY. BUT ANY WIDESPREAD DENSE FOG IS UNLIKELY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...KEC AVIATION...KC MARINE...KC
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
604 AM EDT SUN AUG 3 2014 LATEST UPDATE... UPDATE .SYNOPSIS... ISSUED AT 330 AM EDT SUN AUG 3 2014 A WEAK HIGH PRESSURE RIDGE WILL BRING FAIR WEATHER TODAY WITH SEASONABLY WARM TEMPERATURES. A WEAK COLD FRONT WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS MONDAY INTO MONDAY EVENING. A FEW SHOWERS AND STORMS WILL LINGER MAINLY NEAR TO SOUTH OF INTERSTATE 96 TUESDAY BEFORE DRY WEATHER RETURNS WEDNESDAY THROUGH THE REMAINDER OF THE WEEK. TEMPERATURES WILL AVERAGE RATHER CLOSE TO NORMAL THROUGH THE UPCOMING WEEK. && .UPDATE... ISSUED AT 604 AM EDT SUN AUG 3 2014 I HAVE UPDATED OUR GRIDS AND ZONE FORECAST TO INCLUDE AREAS OF DENSE FOG NORTH AND EAST OF US-131 AND I-96 TILL ABOUT 9 AM. THE RAP MODEL SHOWS THE LOW LEVEL FLOW HAS BEEN OFF LAKE HURON INTO CENTRAL LOWER MICHIGAN AIMED DIRECTLY INTO THE WHERE DENSE FOG HAS DEVELOPED. THE RAP MODEL VISIBILITY FORECAST...WHICH IS DOING GREAT ON THE AREA OF DENSE FOG CURRENTLY (05 AM) SHOWS IT TOTALLY MIXING OUT BY 9 AM. THAT MAKES SENSE AS THERE IS LITTLE IN THE WAY OF CLOUDS OVER THE FOG AND IT IS SHALLOW FOG TOO. AFTER COORDINATING WITH APX ON THE ISSUE WE DECIDED NOT TO ISSUE A DENSE FOG ADVISORY BUT JUST TO PUT AREAS OF DENSE FOG IN THE GRIDS AND CALL THAT GOOD. && .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 330 AM EDT SUN AUG 3 2014 OUR PRIMARY SHORT TERM FORECAST CONCERNS INVOLVE DETERMINING POTENTIAL FOR CONVECTION MONDAY THROUGH TUESDAY. A WEAK COLD FRONT WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS MONDAY INTO MONDAY NIGHT. THE BEST CHANCE FOR STORMS MONDAY WILL BE NEAR TO MAINLY EAST OF US-131 WHERE THERE WILL BE LESS OF A STABILIZING INFLUENCE FROM LAKE MI. SB CAPE VALUES WILL POTENTIALLY REACH AROUND 2000 J/KG OVER OUR EASTERN FCST AREA AS SUGGESTED BY LATEST 00Z GFS AND ECMWF GUIDANCE. HOWEVER ML CAPE VALUES MAY ONLY REACH AROUND 750 J/KG OVER OUR SE FCST AREA ACCORDING TO LATEST SREF GUIDANCE. SEVERE WEATHER IS NOT ANTICIPATED DUE TO RELATIVELY WEAK FORCING FROM THE WEAK COLD FRONT... WEAK 0-6 KM BULK SHEAR VALUES OF ONLY AROUND 15-20 KTS AND LACK OF STRONGER INSTABILITY. A CONSENSUS OF LATEST SHORT RANGE GUIDANCE SUGGESTS SCATTERED SHOWERS AND PERHAPS A FEW STORMS WILL LINGER MONDAY NIGHT AND THEN INTO TUESDAY MAINLY NEAR TO SOUTH OF I-96. HOWEVER WEAKER INSTABILITY IS ANTICIPATED TUESDAY AND IT WILL BE MORE CONFINED TO THE AREA NEAR TO SOUTH OF I-96. A WEAK HIGH PRESSURE RIDGE WILL BRING FAIR AND SEASONABLY WARM WX TODAY WITH MAX TEMPS REACHING THE LOWER TO MIDDLE 80S... EXCEPT A LITTLE COOLER RIGHT ALONG THE LAKE MI SHORELINE DUE TO SW FLOW AND THE LAKE BREEZE OFF OF RELATIVELY COLD LAKE WATERS. CANNOT COMPLETELY RULE OUT POTENTIAL FOR AN ISOLATED SHOWER NEAR OR EAST OF US-131 THIS AFTERNOON BUT THERE IS NOT ENOUGH POTENTIAL IN IT TO WARRANT INCLUSION IN THE FCST. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 335 AM EDT SUN AUG 3 2014 IT WOULD NOT BE OUT OF THE QUESTION THERE COULD BE A LINGERING SHOWER OR THUNDERSTORMS INTO EARLY WEDNESDAY BEHIND THE COLD FRONT THE PRIMARY MESSAGE FOR THIS FORECAST TIME PERIOD WEATHERWISE IS DRY. TEMPERATURES WILL ONCE AGAIN FALL BELOW NORMAL DURING THE MID WEEK PERIOD. BY THE WEEKEND EXPECT TEMPERATURES TO RISE TO ABOVE NORMAL LEVELS... BUT STILL I DO NOT SEE HIGHS IN THE 90S... MORE LIKE MID 80S HIGHS BY SATURDAY. AS I HAVE BEEN SAYING THE PAST FEW NIGHTS... THE EASTERN TROUGH FORECAST BY THE ECMWF WILL BE STRONG ENOUGH TO BRING THE POLAR JET SOUTH OF MICHIGAN ONCE AGAIN BY WEDNESDAY. WE THEN GET SHORTWAVE RIDGING TO BUILD INTO THE AREA BY SATURDAY. THAT WILL BRING THE WARMER TEMPERATURES TO THE AREA. UNLIKE THIS LAST DEEP UPPER TROUGH WHEN THE POLAR JET WAS WELL SOUTH OF MICHIGAN FOR SEVERAL DAYS... THIS TIME IT WILL BE ONLY FOR A DAY. THAT MEANS THERE WILL NOT BE ENOUGH COLD AIR ALOFT FOR AFTERNOON CONVECTION. HENCE THE DRY FORECAST FOR WEDNESDAY AFTERNOON THROUGH SATURDAY. ONE THING TO WATCH FOR... TUESDAY NIGHT WE HAVE THE JET EXIT REGION OVER SOUTHWEST MICHIGAN. THAT MAY BE ENOUGH TO SUPPORT SOME THUNDERSTORM ACTIVITY. HOWEVER AT THIS POINT IT LOOKS LIKE TO MUCH DRY AIR AT MID LEVELS. EVEN SO I HAVE LOW CHANCE POPS FOR THE SOUTHERN SECTIONS OF THE CWA TUESDAY NIGHT INTO WEDNESDAY MORNING JUST I CASE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1155 PM EDT SAT AUG 2 2014 MVFR TO LOCALLY IFR CONDITIONS IN FOG DEVELOPING BY 09-10Z. CONDITIONS IMPROVING TO VFR AFTER 13Z SUNDAY. NO CONVECTION ANTICIPATED ON SUNDAY AFTERNOON. && .MARINE... ISSUED AT 330 AM EDT SUN AUG 3 2014 A WEAK PRESSURE GRADIENT WILL CONTINUE TO RESULT IN FAIRLY MINIMAL WIND AND WAVE ACTION THE NEXT COUPLE OF DAYS WITH WAVE HEIGHTS UNDER TWO FEET. HOWEVER SOME PATCHY FOG THAT MAY BE DENSE AT TIMES IS ANTICIPATED THAT WILL CONTINUE TO POSE A HAZARD TO MARINERS DUE TO RELATIVELY COLD LAKE WATERS AND HIGHER DEW POINT AIR JUST ABOVE THE LAKE SURFACE. && .HYDROLOGY... ISSUED AT 306 PM EDT SAT AUG 2 2014 NO HYDRO ISSUES DUE TO A FAIRLY DRY WEATHER PATTERN. BRIEF PERIODS OF LOCALLY HEAVY RAINFALL ARE POSSIBLE THIS EVENING IN SCATTERED THUNDERSTORMS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ UPDATE...WDM SYNOPSIS...LAURENS SHORT TERM...LAURENS LONG TERM...WDM AVIATION...MEADE HYDROLOGY...93 MARINE...LAURENS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
352 AM EDT SUN AUG 3 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 351 AM EDT SUN AUG 3 2014 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NW FLOW OVER THE UPR LKS BTWN TROF CENTERED OVER QUEBEC AND MEAN RDG OVER THE ROCKIES. DESPITE SHARP MID LVL INVRN/VERY DRY MID LVLS SHOWN ON THE 00Z GRB RAOB ASSOCIATED WITH SHRTWV RDG PASSING THRU THE UPR LKS THAT IS BRINGING MOCLR CONDITIONS TO UPR MI...THERE ARE SOME ISOLD SHOWERS OVER WI AND FAR WRN UPR MI IN ADVANCE OF A SHRTWV DROPPING SEWD THRU SRN MN. A STRONGER SHRTWV EMBEDDED IN THE NW FLOW ALF IS MOVING ESEWD THRU NW ONTARIO...WITH ATTENDANT RATHER WEAK SFC-H85 COLD FNT MOVING INTO NRN MN. THERE WERE SOME SHOWERS/TS LAST EVNG OVER FARN NRN MN/ADJOINING ONTARIO IN ADVANCE OF THIS FNT IN THE FAIRLY MOIST ENVIRONMENT DEPICTED ON THE 00Z INL RAOB /00Z PWAT WAS 1.25 INCH OR ALMOST 150 PCT OF NORMAL AND KINX WAS 32/...BUT LOSS OF DAYTIME HEATING...PASSAGE OF SHARPER FORCING TO THE N AND ABSENCE OF SGNFT H85-7 MSTR INFLOW NECESSARY TO SUSTAIN NOCTURNAL CONVECTION HAVE CAUSED THESE SHOWERS TO DIMINISH ALMOST ENTIRELY EARLY THIS MRNG IN AN ENVIRONMENT WHERE MUCAPE IS 100-250 J/KG AT BEST. MAIN FCST CONCERNS THRU TNGT ARE FOCUSED ON POPS ASSOCIATED WITH APRCHG COLD FNT. TODAY...SHRTWV OVER ONTARIO IS PROGGED TO CONTINUE ESEWD...WITH ATTENDANT SFC COLD FNT ON A LINE THRU NW LK SUP AT 12Z THIS MRNG FCST TO REACH THE SE CWA BY LATE THIS AFTN. WL CARRY ONLY ISOLD SHOWERS THIS MRNG OVER THE NW CWA ASSOCIATED WITH THE FROPA GIVEN PRESENT COVERAGE ALONG THE FNT AND PASSAGE OF SHARPER FORCING TO THE N. BUT AS THE FNT/MID LVL COMMA TAIL MSTR RIBBON PRESSES TO THE SE THIS AFTN IN THE PRESENCE OF DAYTIME HEATING...EXPECT THE SHOWER/TS COVERAGE TO INCRS. INTERACTION BTWN THE FNT AND LK BREEZE BNDRYS THAT WL SHARPEN THE LLVL CNVGC WL ALSO AID THE CONVECTION. BOTH THE 00Z NAM/LOCAL WRF-ARW MODELS INDICATE THE LI WL DROP AS LO AS -6 TO -8C AS MUCAPES REACH ARND 2500 J/KG THIS AFTN OVER THE SCNTRL CWA... JUSTIFYING THE GOING LIKELY POPS IN THE CURRENT FCST FOR THAT AREA THIS AFTN. WITH SFC-6KM BULK SHEAR AS HI AS 30 KTS...THERE COULD BE SOME STRONGER CELLS. WITH SFC TEMPS RISING TO 80-85 AHEAD OF THE FNT RESULTING IN ADIABATIC LAPSE RATES IN THE PBL...GUSTY WINDS SHOULD BE THE MAIN THREAT. BUT MARGINAL LAPSE RATES AND SHEAR INDICATE SVR WX IS NOT LIKELY. TNGT...ARRIVAL OF SOME DRYING ALF FOLLOWING THE FROPA AND LOSS OF DAYTIME HEATING SHOULD RESULT IN LINGERING POPS OVER THE SE CWA DIMINISHING THIS EVNG. BUT SINCE SEVERAL MODELS SHOW ANOTHER WEAKER SHRTWV DROPPING SEWD IN THE NW FLOW ALF AND ASSOCIATED DPVA/DEEP LYR QVECTOR CNVGC IMPACTING THE CWA OVERNGT...WL RETAIN SOME LOWER CHC POPS MAINLY OVER THE SRN TIER CLOSER TO THE HIER LINGERING PWAT AOA AN INCH. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 351 AM EDT SUN AUG 3 2014 GENERALLY QUIET WEATHER EXPECTED THROUGH THE EXTENDED WITH DRY WEATHER AND MODERATING TEMPERATURES EXPECTED. ISOLATED SHOWERS AND THUNDERSTORMS ARE POSSIBLE NEAR THE WISCONSIN BORDER DURING THE DAY MONDAY AS A SHORTWAVE PASSES THROUGH THE BROAD TROUGHING STILL IN PLACE OVER MUCH OF THE EASTERN U.S. THE BETTER FORCING AN MOISTURE IS EXPECTED TO REMAIN MAINLY SOUTH OF THE REGION AS THE VORT MAX SWINGS THROUGH...HOWEVER...IT WILL BRUSH CLOSE ENOUGH TO THE U.P./WI BORDER TO KEEP SLIGHT POPS IN THE FORECAST. ANOTHER SHORTWAVE IS PROGGED TO ROTATE AROUND THE TROUGH TUESDAY NIGHT...HOWEVER...CONDITIONS WILL REMAIN DRY AS THIS WILL SWING THROUGH DURING THE COOLER OVERNIGHT HOURS WITH VERY LIMITED MOISTURE AVAILABLE DURING THAT TIME. THE REMAINDER OF THE EXTENDED...WEDNESDAY THROUGH SATURDAY WILL BE DOMINATED BY BROAD SURFACE HIGH PRESSURE ALONG WITH UPPER LEVEL 500MB RIDGING SLIDING FROM THE WESTERN U.S. INTO THE CENTRAL U.S. THIS WILL ALLOW TEMPERATURES TO WARM TO NEAR OR SLIGHTLY ABOVE NORMAL BY THE END OF THE WORK WEEK AND INTO THE UPCOMING WEEKEND. CONDITIONS WILL REMAIN DRY AS DRY AIR REMAINS IN PLACE ACROSS THE GREAT LAKES REGION THROUGH THIS TIME PERIOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 126 AM EDT SUN AUG 3 2014 DRY HI PRES WILL MAINTAIN VFR CONDITIONS AND LGT WINDS AT TAF SITES OVERNIGHT. MID CLDS IN ADVANCE OF AN APRCHG DISTURBANCE/COLD FNT WL ARRIVE LATE TNGT WHILE ISOLD TO SCT SHRA MOVE ACROSS THE AREA ON SUNDAY WITH THE FRONTAL PASSAGE. GIVEN UNCERTAINTY OF THE SHRA COVERAGE ALONG THE FRONT ON SUNDAY HAVE ONLY MENTIONED VCSH IN THE TAFS. INCLUDED VCTS IN KSAW WHERE THERE WILL BE BETTER INSTABILITY AND ENHANCED CONVERGENCE ALONG POSSIBLE LAKE BREEZE BOUNDARIES. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 351 AM EDT SUN AUG 3 2014 TYPICAL SUMMER TYPE FLOW REGIME/WEAK PRES GRADIENT WILL KEEP WINDS UNDER 15 KT THROUGH MUCH OF THIS COMING WEEK. SOME PATCHY FOG IS POSSIBLE INTO MON...ESPECIALLY IF RAIN FALLS TODAY. BUT ANY WIDESPREAD DENSE FOG IS UNLIKELY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...KEC AVIATION...VOSS MARINE...KC
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
955 PM CDT Mon Aug 4 2014 .UPDATE: Issued at 955 PM CDT Mon Aug 4 2014 Scattered thunderstorms that were over northern Missouri earlier this evening have dissipated. Still expect additional development over the next few hours as the RAP shows an increase in 925-850mb moisture convergence though 06Z over central and northeast Missouri and west central Illinois that will shift southeast across the CWA through 12Z. Have mainly slight chances of thunderstorms the rest of the evening, but then have low chance pops again overnight. Rest of the forecast including temperatures still looks good and have made only minor adjustments based on latest observations. Britt && .SHORT TERM: (Through Late Tonight) Issued at 356 PM CDT Mon Aug 4 2014 Weak warm advection has fueled the redevelopment of spotty convection just to the east of a KIRK-KCOU-Eminence line over the past few hours. Consensus of much of the short-range, hi-res guidance is that this activity will work east and likely weaken during the evening, but expect another uptick in PoPs after 06z as subtle veering of weak low level jet focuses somewhat stronger lift in a N-S axis roughly centered near or just west of STL area during the predawn hours. Overnight mins are expected to be a couple of degrees warmer than those of last night, primarily due to clouds. Truett .LONG TERM: (Tuesday through Next Monday) Issued at 356 PM CDT Mon Aug 4 2014 12z runs are forecasting a very subtle flattening of the mid level flow regime over the mid-Mississippi heading into midweek. This will cause a southward shift in the baroclinicity and frontal boundary currently locked to our north, and ultimately result in increasing rainfall chances over much of the CWA. By the end of the week, many parts of the CWA should have received some very welcomed wet weather. This morning`s runs offer fairly similar solutions regarding precip trends into Tuesday night. Thunderstorms that manage to develop overnight tonight should drift south and weaken on Tuesday morning, and I`ve continued low PoPs into tomorrow afternoon for areas along and south of a KCOU-KUIN line as surface boundary will be lingering over this part of the FA, and interacting with the increasingly unstable AMS driven by diurnal heating. Any storms that manage to develop Tuesday afternoon should weaken during the evening. Model consensus remains fairly good agreement with large scale trends heading into Tuesday night, with synoptic scale models all forecasting the intensification of the low level jet over the mid Missouri Valley during the late night hours. The resultant theta-e advection/lift should lead to the development of an MCS over IA that will roll southeast, with the leading edge of this system threatening northern sections of our CWA late Tuesday night. NAM is a bit further north with the QPF of this system than the GFS and the ECMWF, and since the NAM has been a bit too far north with the last few convective complexes, have given a nod to the consensus of the more southern solutions. Guidance specifics become a bit more murky heading into Wednesday and Thursday, but all solutions indicate persistent low level WAA into the area, combined with one or shortwaves/vort maxes drifting across the region. Thunderstorm threat on Wednesday will likely be a combination of the aforementioned MCS over northeast parts of the CWA, along with additional more scattered development occurring further to the south due to the above forcing mechanisms, along with possible outflow interaction and increasingly unstable afternoon airmass. Have continued our highest PoPs for Wednesday night and Thursday, as increased baroclinicity should lead to the best low level forcing during this time frame. Heading into the medium range ridge begins to re-exert its influence, but whats left of the westerly flow will allow weak dynamics to cross the area, interacting with the residualy unstable airmass and baroclinic zone that remains parked over the region. Have maintained earlier forecast trends for now, keeping fairly high PoPs into Thursday night, then slowly backing off to low/slight chance PoPs over the weekend and into early next week. Temperature-wise, fairly typical late summer readings can be expected tomorrow, but the combination of clouds and the southward push of cooler air should mean cooler weather over northeast parts of the CWA on Wednesday, and over the rest of the area by Thursday and Friday. Truett && .AVIATION: (For the 00z TAFs through 00z Tuesday Evening) Issued at 555 PM CDT Mon Aug 4 2014 Specifics for KCOU/KUIN: Widely scattered convection should diminish after sunset with at least a few hours of VFR conditions at KCOU/KUIN before redevelopment occurs overnight. Confidence in SH/TS is higher at KUIN than at KCOU based on model forecasts of the low level jet. A slow moving cold front will sag southward overnight and tomorrow. Depending on where the front is located tomorrow afternoon, scattered convection is possible at KCOU after 18z. Specifics for KSTL/KSUS/KCPS: Isolated SH/TS possible over the next 2 hours due to an unstable air mass over the region. VFR conditions are expected for several hours after sunset. Uncertainty then increases after 06z because new SH/TS development may occur north of the metro area terminals and then move southward overnight, possibly reaching KSTL/KSUS/KCPS before 12z. Another factor to consider is a slow moving cold front which will sag southward tonight and tomorrow. Depending on where the front is located tomorrow afternoon, scattered convection is possible again at KSTL/KSUS/KCPS, generally after 18z. Kanofsky && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
707 PM CDT Mon Aug 4 2014 .SHORT TERM...(This Evening through Tuesday) Issued at 240 PM CDT MON AUG 4 2014 A nice cumulus field is developing with daytime heating and instability this afternoon especially over southern Missouri. There is a very subtle upper level shortwave moving through the area this afternoon. The latest HRRR is indicating isolated to scattered convection to develop by 22z near I-44 and move southward into the early evening hours. Will still carry 20 to 30 percent pops for this general area into the evening hours. Another upper level wave will move across the northern part of the state by early tomorrow morning with some possible convection making its way into central Missouri and the eastern Ozarks tomorrow morning. Will carry a slight mention of pops for tomorrow morning for this general area and a slightly better chance for convection east of Highway 65 Tuesday afternoon. .LONG TERM...(Tuesday Night through Monday) Issued at 240 PM CDT MON AUG 4 2014 The upper level ridge of high pressure which has been in control of our weather pattern will break down somewhat over us and allow multiple shortwaves to ride down a west-northwest flow. A front will meander into the region by Thursday and pretty much stall out over the Missouri Ozarks or nearby through weekend. There will be several rounds of convection and possible MCS activity riding along that front through the area. The first chance for widespread convection will be late Wednesday night into Thursday morning with another rounds developing Thursday night into Friday morning and possibly another round Friday night into Saturday morning. Timing and exact placement is difficult to pinpoint down at this time. The ECMWF is most bullish than the GFS and GEM but all have the same idea. Will mention a slight risk for heavy rainfall and some flash flooding threat for the end of the week with widespread one to three inches likely with isolated higher amounts over the eastern Ozarks and central Missouri areas. Temperatures by the end of the week will be dependent on where the stalled front is positioned and on going convection and cloud cover...but generally cooler temperatures in the lower 80s for the eastern half of the CWA and upper 80s for southeast Kansas and far southwest Missouri for the Thursday through Saturday time frame. The front finally lifts back to the north or washes out by early next week with temperatures moderating back to near normal and slight pops lingering in the afternoon. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday Evening) Issued at 700 PM CDT MON AUG 4 2014 For the KSGF/KJLN/KBBG tafs: Isolated shra/tsra should not affect taf sites in the near term, so expect vfr conditions. A sfc trough will move slowly south into central/southern MO during the taf period veering winds to the west toward 15z. The trough may trigger some scattered convection once again Tue, but coverage is expected to be sparse, but maybe a little more than the past couple of days. && .SGF WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ SHORT TERM...Griffin LONG TERM...Griffin AVIATION...DSA
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1207 AM CDT Sun Aug 3 2014 .UPDATE... Issued at 1207 AM CDT SUN AUG 3 2014 Convection is developing over the Mid-Missouri River Valley near Omaha ahead of a weak vort max dropping in from the north. HRRR has had a good handle on this convection and brings it into northwest MO and toward the KC area later tonight toward sunrise. 00Z TOP sounding indicates a deep enough unstable layer in the boundary layer that shallow decoupling shouldn`t have much effect on MUCAPE values which are progged to be around 1000 J/kg. Have therefore bumped PoPs up to as high as 50 percent across northwest MO late tonight and into the chance category as far south as the KC metro early Sunday morning. && .DISCUSSION... Issued at 259 PM CDT SAT AUG 2 2014 Tonight through Sunday: As of early this afternoon, a shallow cumulus field has developed over much of the area. Some of this activity is slightly more enhanced across eastern Kansas, and may spawn a few light showers just west of the forecast area through early evening. A decaying area of showers continues to push southward over far southeast Nebraska, but is not expected to gain intensity or coverage. Outside of far northwestern sections of the CWA, the trajectory should keep most areas dry through this evening. Models show a weak shortwave trough to move across the region late tonight into tomorrow morning. Have continued a slight chance for thunderstorms over the northwest quarter of the forecast area tonight into tomorrow as this feature moves through, but most locations should remain dry. Otherwise, similar temperatures are expected on Sunday, with highs warming into the middle 80s to near 90 degrees. Monday/Tuesday: Northwest flow aloft with continue over the region, with maximum temperatures increasing daily with readings in the upper 80s to middle 90s. Slight chances for thunderstorms will continue for most sections each day as projected subtle upper disturbances within the northwest flow move across the area. Coverage of precipitation is not expected to be widespread nor persistent for lengthy periods of time. Wednesday through Saturday: The extended forecast features increasing probabilities for precipitation with persistent northwest flow aloft. The general pattern as advertised by numerical models suggest several upper disturbances to move across the region during the period, with one or more thunderstorm complexes to develop upstream and move into portions of the area. Additional thunderstorms may develop along a quasi-stationary frontal boundary oriented northwest-southeast, located over or just southeast of the forecast area. While uncertainty remains with regards to the specifics, the overall pattern provides increasing confidence for measurable rainfall for many locations during the extended period, especially during the Wednesday/Thursday timeframe. In addition, temperatures will be cooler than earlier in the week with readings closer to or slightly cooler than seasonal averages. && .AVIATION...(For the 06Z TAFS through 06Z Sunday Night) Issued at 1207 AM CDT SUN AUG 3 2014 Thunderstorms developing near Omaha appear poised to hold together longer than previously anticipated and could affect the STJ and KC areas toward sunrise. Chances for storms at these airports are running around 30 to 40 percent, and therefore introduced VCTS to the TAFs early Sunday morning. If this activity continues to hold together prevailing or tempo groups will be needed. Any storms this far south should be fairly weak in intensity. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...NONE. MO...NONE. && $$ UPDATE...Hawblitzel DISCUSSION...Blair AVIATION...Hawblitzel
AREA FORECAST DISCUSSION
NWS GLASGOW MT
834 PM MDT MON AUG 4 2014 .SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH WEDNESDAY... EVENING UPDATE... CHANGES FOR THIS EVENING FOCUSED AROUND GRABBING THE MODEL DATA THAT MOST CLOSELY RESEMBLES THE CURRENT RADAR TRENDS AND SKEWING POPS TOWARDS THAT DATA. ITS A THIRD DAY OF THE PICK YOUR FAVORITE MESOSCALE MODEL GAME WHEN IT COMES TO STORM DEVELOPMENT. SO FINDING THE MODELS THAT INITIALIZE QPF THE BEST WITH RADAR TRENDS AND EXTRAPOLATING IT IS THE TECHNIQUE BEING USED. HRRR SEEMS TO HAVE THE BEST HANDLE ON CURRENT CONVECTION AND SHOWERS OVER TREASURE AND FERGUS COUNTY. IT ALSO SEEMS TO BRING THAT QPF UP INTO THE CWA ON THE SAME VECTOR THAT RADAR IS SHOWING. THEREFORE RAISED POPS ACROSS PETROLEUM... GARFIELD... AND PHILLIPS COUNTY TROUGH 6AM BASED ON THIS GUIDANCE. MESO WIND FIELDS ALSO SHOW THE WIND SHIFTING BEHIND THE SURFACE TROUGH WHICH IS GUIDING THIS CONVECTION. GAH PREVIOUS SHORT TERM DISCUSSION... THE SHORT TERM FORECAST PERIOD BEGINS THIS EVENING WITH HIGH PRESSURE OVER TEXAS ANCHORING AN UPPER RIDGE THAT EXTENDS NORTH INTO MONTANA. WEST OF THE RIDGE IS AN OPEN TROUGH HEADING NORTHEAST TOWARDS MONTANA. THIS WAVE HAS PICKED UP A SIGNIFICANT AMOUNT OF PACIFIC MONSOONAL MOISTURE THAT WILL BRING WIDESPREAD RAIN SHOWERS TO NORTHEAST MONTANA TONIGHT AND TUESDAY. A LEE-SIDE CLOSED LOW IN SOUTHERN BC AND ALBERTA WILL ADD ENERGY TO THE INCOMING WAVE. BY WEDNESDAY THE OPEN WAVE WILL HAVE MOVED OFF TO NORTH DAKOTA TO ALLOW THE RIDGE TO MOVE BACK OVER MONTANA... CUTTING OFF MOST MOISTURE. THE OPEN WAVE RIDING ACROSS THE REGION WILL CAP TEMPERATURES CLOSE TO SEASONAL. THIS EVENING AND LATER TONIGHT...AMPLE MOISTURE AND HEATING THIS AFTERNOON COULD LEAD TO ANOTHER ROUND OF ISOLATED TO SCATTERED THUNDERSTORMS. ALTHOUGH CONVECTIVE PARAMETERS ARE NOT STRONG...A FEW EVENING STORMS MAY BECOME SEVERE. THEREFORE SPC HAS PLACED A SEE TEXT OVER US IN ITS CONVECTIVE OUTLOOK FOR TODAY. RADAR AND SATELLITE IMAGERY AROUND NOON TODAY SHOW A WET SYSTEM OVER WYOMING AND IDAHO THAT IS HEADING OUR WAY. THIS SYSTEM WILL BRING ABOUT AN INCREASING CHANCE FOR WETTING RAINS TONIGHT. TUESDAY/TUESDAY NIGHT...MODELS SUGGEST RAIN SHOWERS AND THUNDERSTORMS WILL CONTINUE. TRYING TO DETERMINE QPF AMOUNTS AT ANY TIME IS LIKE TRYING TO NAIL JELLO TO THE WALL. BUT USING A CONSENSUS OF MODEL DATA...QPF AMOUNTS DO SUGGEST WETTING RAINS CONTINUING. CURRENTLY THROUGH THE SHORT TERM HAVE AROUND ONE THIRD TO ONE INCH STORM TOTAL QPF. WITH WEAK TO MODERATE CONVECTIVE PARAMETERS IN PLACE A FEW STRONG STORMS ARE YET POSSIBLE. WEDNESDAY...RAINS TAPER OFF QUICKLY AND CONDITIONS BECOME STABLE FROM INCREASING HIGH PRESSURE FROM THE WEST. SO WILL TREND POPS LOWER. SCT .LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY... 12Z MODELS DID NOT REVEAL ANYTHING NEW SO NO NEW CHANGES WERE MADE. UPPER FLOW IS WEAK AND MODELS TEND NOT TO PERFORM WELL THIS TIME OF YEAR DURING THIS PERIOD. DID TWEAK WINDS/TEMPS AND RH THROUGH DAY 5 SLIGHTLY TO MODEL CONSENSUS. JAMBA PREVIOUS DISCUSSION... WILL SEE QUASI-ZONAL FLOW ALOFT ON THURSDAY WITH UPPER RIDGE TO THE SOUTH. WEAK SHORTWAVE IN THE FLOW ALOFT THURSDAY NIGHT ALONG WITH A WEAK FRONTAL BOUNDARY MAY BE ENOUGH TO PRODUCE A SHOWER OR THUNDERSTORM THURSDAY THROUGH FRIDAY. MODELS ARE POINTING TOWARDS AN UPPER RIDGE EXPANDING NORTH INTO MONTANA FOR THE WEEKEND WITH SUMMERLIKE TEMPERATURES. THERE IS A SHORTWAVE TROUGH FORECASTED BY THE MODELS TO MOVE ACROSS ALBERTA AND SASKATCHEWAN SATURDAY THAT AT THE MOMENT STAYS FAR ENOUGH NORTH TO KEEP NE MONTANA DRY. THE RIDGE REMAINS IN PLACE SUNDAY AND MONDAY WITH MAINLY DRY WEATHER. FORRESTER && .AVIATION... FLIGHT CATEGORY: VFR. SYNOPSIS: A WEAK SURFACE BOUNDARY WILL REMAIN OVER THE REGION THROUGH THE NEXT 24 HOURS. THIS BOUNDARY WILL BE THE FOCUS OF ISOLATED THUNDERSTORM DEVELOPMENT FROM TIME TO TIME THROUGH THE PERIOD. THE GREATEST COVERAGE AND INTENSITY SHOULD BE TUESDAY AFTERNOON. IMPACTS: GUSTY AND ERRATIC WIND IN AND AROUND ANY THUNDERSTORMS. PROTON && .GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE. && $$ WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS BILLINGS MT
819 PM MDT MON AUG 4 2014 .UPDATE... EVENING STARTED WITH WIDESPREAD STRATIFORM PRECIPITATION OVER MOST OF THE SOUTHERN ZONES. PRECIP SHIELD MOVED VERY SLOWLY TO THE NORTH AND EAST...BUT ONCE IT GOT NEAR BILLINGS...IT DISSIPATED FAIRLY RAPIDLY DUE TO DRIER AMBIENT AIR. NSSL WRF ARW REFLECTIVITY FORECASTS DID A VERY GOOD JOB OF PREDICTING THIS. CURRENT WATER VAPOR IMAGERY SHOWS DRY AIR PUNCHING NORTHWARD INTO SOUTHERN IDAHO. THIS DESTABILIZATION IS CAUSING SOME THUNDERSTORMS TO FORM WITH FREQUENT LIGHTNING. LATEST GFS RUN SHOWS HIGHER QPF AMOUNTS...ESPECIALLY FOR FAR EASTERN ZONES. BASED ON WHAT WE HAVE SEEN OVER THE LAST FEW HOURS...DECIDED TO KEEP THE FORECAST AS IS FOR THE REST OF THE NIGHT. SINGER && .SHORT TERM...VALID FOR TUE AND WED... SCATTERED TO NUMEROUS SHOWERS AND STORMS ARE EXPECTED FROM TONIGHT THROUGH TUE NIGHT WITH LOCALLY HEAVY RAINFALL A POSSIBILITY THANKS TO ANOMALOUS ATMOSPHERIC MOISTURE CONTENT IN MONSOONAL FLOW. GIVEN THE CONVECTIVE NATURE OF THIS SCENARIO...NOT EVERYONE IS LIKELY TO RECEIVE HEAVY RAINFALL THOUGH. AS OF MID AFTERNOON...SHOWERS AND STORMS ARE FILLING IN OVER SOUTH CENTRAL MT AND NORTH CENTRAL WY AS FORCING WITH A LEAD AND DEFINED SHORTWAVE IMPULSE HEADS NORTHWARD INTO THE REGION. MOST ALL OF THE 12 UTC GUIDANCE CONTINUED SHOWING MODERATE QG-FORCING SPREADING TO THE NORTHEAST THROUGH TONIGHT...SO WE BELIEVE THE SHOWER AND STORM ACTIVITY WILL FOLLOW SUIT. RECENT HRRR RUNS ARE ON BOARD WITH THIS IDEA AND WE FOLLOWED ITS SOLUTION HEADING THROUGH THE EVENING WITH LIKELY POPS SPREADING NORTHEASTWARD. THE SYNOPTIC-SCALE QG-FORCING WITH THIS SHORTWAVE IMPULSE IS MAINLY RELEGATED TO SOUTHEASTERN MT ON TUE...AND IT WILL BE DECREASING WITH TIME. HOWEVER...CONVECTION SHOULD NONETHELESS BE DIURNALLY ENHANCED ACROSS THE ENTIRE AREA BY AFTERNOON IN A MOIST AND WEAKLY UNSTABLE AIR MASS. THE 15 UTC SREF SUPPORTS 300-800 J/KG OF SBCAPE...WEAK MID-LEVEL LAPSE RATES...AND UNDER 25 KT OF 0-6-KM SHEAR...SUGGESTIVE OF SLOW-MOVING STORMS AND LOCALLY HEAVY RAINFALL. MOST 12 UTC GUIDANCE...INCLUDING THE NCEP- RUN CONVECTION-ALLOWING MODELS...SUGGEST THE MOST INTENSE ACTIVITY OVER THE NEXT 48 HOURS MAY BE LATE TUE AFTERNOON INTO TUE NIGHT IN SOUTHEASTERN MT. THAT IS REASONABLE AS THAT AREA MAY HAVE A BETTER OPPORTUNITY TO DESTABILIZE WITH RELATIVELY GREATER CAPE SUPPORTIVE OF MORE CONCENTRATED UPDRAFTS /DEPENDING ON THICKNESS OF CLOUDS/. AS FOR THE HEAVY RAINFALL POTENTIAL...SPC SSEO OUTPUT REVEALS MEAN RAINFALL TOTALS TONIGHT OF 0.20 TO 0.40 INCHES...AND THE 09 AND 15 UTC SREF RUNS SUGGESTED LESS THAN A 30 PERCENT PROBABILITY OF 0.50 INCHES OR MORE OF RAIN. DEEPER CONVECTION WILL YIELD LOCAL AMOUNTS HIGHER THAN THAT...BUT THE STATISTICAL EVIDENCE POINTS AWAY FROM A WIDESPREAD HEAVY RAIN EVENT. THE SREF DOES SUGGEST A HIGHER CHANCE OF GREATER THAN A HALF INCH OF RAIN OVER SOUTHEAST MT IN THE BAKER AND EKALAKA AREAS LATE TUE AFTERNOON INTO TUE NIGHT...MATCHING THE SIGNALS SEEN IN THE 12 UTC DETERMINISTIC MODEL OUTPUT FOR A THREAT OF MORE BONAFIDE HEAVY RAIN IN THAT PART OF SOUTHEASTERN MT. BY WED...WEAK INSTABILITY WILL STILL EXIST AND IS SUFFICIENT FOR A CHANCE OF SHOWERS AND STORMS...BUT GENERALLY-SPEAKING WE FEEL THAT THE PROBABILITY WILL BE LOWER THAN TUE WITHOUT ANY DEFINED FORCING ALOFT. HIGHS TUE WILL PROBABLY NOT REACH 80 F GIVEN THE CLOUDS AND MOISTURE /AND WE DID LOWER HIGHS A BIT TOWARD THE 00 UTC CONSENSUS OF RAW...2 M MODEL TEMPERATURE OUTPUT/...BUT THEY SHOULD WARM UP A BIT AGAIN WED IF CLOUD COVER IS SOMEWHAT LESS THAT DAY. SCHULTZ .LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON... MODELS WERE IN PRETTY GOOD AGREEMENT THROUGH THE FORECAST PERIOD. ENERGY GRADUALLY WORKS ACROSS THE FORECAST AREA THURSDAY AND FRIDAY FOR WEAK LIFT AND SOME INSTABILITY. LINGERING MONSOON MOISTURE WILL ALSO BE INVOLVED HERE SO NEED TO KEEP SOME MENTION OF POPS. QUESTION FOR ME IS THE DRY AIR PRESENT ON WATER VAPOR IMAGERY WORKING INTO SOUTHERN ARIZONA. HOW WILL THIS WORK TO DRY OUT THE MONSOON PLUME WORKING INTO THE NORTHERN ROCKIES? THIS COULD LIMIT THE CHANCE OF CONVECTION DESPITE THE TROUGH MOVING THROUGH. ALL IN ALL...LOOKS LIKE THE DEEPEST MOISTURE WILL BE EAST OF BILLINGS. DOES NOT LOOK OVERLY HOT THROUGH SATURDAY WITH HEIGHTS STAYING BELOW 588DM. HEIGHTS BUILD LATE IN THE WEEKEND INTO EARLY NEXT WEEK FOR WARMER WEATHER. TWH && .AVIATION... SHOWERS AND THUNDERSTORMS WILL SPREAD NORTHEAST TONIGHT. SOME OF THE STORMS MAY CONTAIN HEAVY RAINFALL WITH LOCAL IFR CONDITIONS. THE MOUNTAINS WILL BE MOSTLY OBSCURED. EXPECT ADDITIONAL SHOWERS AND STORMS ON TUESDAY WITH MONSOONAL MOISTURE REMAINING IN PLACE ACROSS SOUTHERN MT AND NORTH CENTRAL WY. SCHULTZ/TWH && .PRELIMINARY POINT TEMP/POPS... TUE WED THU FRI SAT SUN MON ----------------------------------------------------------- BIL 063/079 059/084 060/087 061/088 061/090 062/090 062/090 75/T 42/T 22/T 22/T 21/U 11/B 11/B LVM 054/078 052/083 053/084 053/086 053/087 054/090 053/089 75/T 43/T 33/T 32/T 22/T 22/T 22/T HDN 064/081 059/086 058/088 059/089 059/091 060/091 061/092 76/T 52/T 22/T 22/T 21/U 11/B 11/B MLS 067/080 062/082 060/087 063/090 063/091 063/092 064/092 67/T 62/T 22/T 22/T 21/U 11/B 11/U 4BQ 064/080 060/082 057/086 060/087 060/089 061/090 063/091 67/T 64/T 22/T 22/T 22/T 21/B 11/U BHK 063/074 058/077 055/083 058/087 057/088 059/089 063/089 67/T 74/T 22/T 22/T 22/T 12/T 21/U SHR 060/077 057/082 055/086 056/086 055/089 056/089 058/087 76/T 63/T 32/T 23/T 32/T 22/T 22/T && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
346 PM CDT SUN AUG 3 2014 .SYNOPSIS... ISSUED AT 345 PM CDT SUN AUG 3 2014 AT 19Z WATER VAPOR IMAGERY SHOWS THE CONTINUED WESTERN RIDGE/EASTERN TROUGH PATTERN ONGOING. HOWEVER THERE IS A POTENT UPPER LEVEL LOW MOVING INTO SOUTHERN CALIFORNIA ON THE WESTERN SIDE OF THE RIDGE. ACROSS CANADA...COULD SEE A FEW NOTABLE SHORTWAVE TROUGHS...THE FIRST OVER NORTHERN SASKATCHEWAN AND THE SECOND OVER SOUTHERN BRITISH COLUMBIA. OTHER WEAK DISTURBANCES COULD ALSO BE SEEN ROUNDING THE RIDGE AND MOVING THROUGH NORTHWEST FLOW INTO THE CENTRAL PLAINS AND UPPER MISSISSIPPI RIVER VALLEY. LOCALLY...A WEAK SURFACE BOUNDARY WAS SEEN FROM NORTHWEST NEBRASKA ARCING DOWN INTO SOUTH CENTRAL NEBRASKA...ROUGHLY FROM KCDR TO KLBF TO KGRI. TEMPERATURES HAD REACHED THE UPPER 80S AND LOW 90S MOST PLACES...WHICH WERE AT OR NEAR FULL MIXING POTENTIAL. STARTING TO SEE SOME CUMULUS POP UP ACROSS THE AREA...WHILE AREAL COVERAGE IS LOW DUE TO A LACK OF MID LEVEL MOISTURE. && .SHORT TERM...(TONIGHT THROUGH MONDAY) ISSUED AT 345 PM CDT SUN AUG 3 2014 ANY SHOWERS OR STORMS THAT DEVELOP ACROSS THE FORECAST AREA THIS AFTERNOON DUE TO THE FAVORABLE LOW AND MID LEVEL CONDITIONS FOR GOOD SB INSTABILITY WITH THE STEEP LOW AND MID LEVEL LAPSE RATES SHOULD BE FAIRLY SHORT LIVED AND EXPECT ANY ACTIVITY TO END EARLY THIS EVENING WITH THE LOSS OF DAYTIME HEATING AND STABILIZATION OF THE BOUNDARY LAYER AS THERE WILL NOT BE SUPPORT ALOFT TO SUSTAIN ANY OF THIS ACTIVITY. ALTHOUGH IT IS DIFFICULT TO PICK OUT IN WATER VAPOR IMAGERY...MODELS INDICATE A WEAK SHORTWAVE TROUGH OVER SOUTHERN MONTANA CURRENTLY...WITH ANOTHER WEAK DISTURBANCE OVER WESTERN SOUTH DAKOTA. THE SD SHORTWAVE MAY BRING ENOUGH LIFT TO BRING SOME SCATTERED SHOWERS AND THUNDERSTORMS INTO NORTHWEST NEBRASKA THIS EVENING. CONFIDENCE IS NOT HIGH IN THIS OCCURRING AS MOISTURE IS FAIRLY LIMITED...BUT THE HRRR AND RAP HAVE BEEN CONSISTENTLY SIGNALING SOME STRONGER CONVERGENCE AND LIFT IN THIS AREA SO WILL INCLUDE A SLIGHT CHANCE IN THIS EVENING OVER THE NORTHWEST CORNER OF THE FORECAST AREA. THEN OVERNIGHT...THE SHORTWAVE TROUGH OVER MONTANA WILL MAKE ITS WAY INTO NORTH CENTRAL NEBRASKA. AS HAS BEEN OCCURRING FOR SEVERAL DAYS...TEMPERATURES ARE COOL ENOUGH IN THE MID LEVELS TO KEEP LAPSE RATES VERY STEEP AND EVEN SLIGHT LIFT FROM WEAK SHORTWAVES SEEMS TO BE ENOUGH TO ALLOW STORMS TO DEVELOP NOCTURNALLY. ALTHOUGH THERE IS QUESTION TO IF THERE WILL BE ENOUGH MOISTURE TO WORK WITH...AND EXACTLY WHERE THE CHANCES WILL BE BEST THE CURRENT THOUGHTS ARE THAT ACTIVITY WILL PASS ACROSS THE NORTHEAST PART OF THE FORECAST AREA...ROUGHLY EAST OF A VALENTINE TO TAYLOR LINE. THIS ENDS EARLY MONDAY MORNING. THE UPPER LEVEL PATTERN DOES BEGIN TO SEE A SHIFT THROUGH THE DAY MONDAY. THE UPPER LOW OVER CALIFORNIA WILL MOVE INTO THE RIDGE WHICH WILL CAUSE THE RIDGE TO START SHIFTING EAST. MEANWHILE...THE SHORTWAVE OVER SASKATCHEWAN WILL DIVE INTO THE GREAT LAKES REGION TO PUSH A COLD FRONT THROUGH THE UPPER MISSISSIPPI RIVER VALLEY AND APPROACH NORTHEAST NEBRASKA BY THE END OF THE DAY. ALSO...THE BRITISH COLUMBIA SHORTWAVE WILL START SLOW EASTERLY MOVEMENT WHICH WILL PLAY THE PART OF FLATTENING THE RIDGE. THIS MOVEMENT IN THE UPPER LEVELS WILL LEAD TO LOW PRESSURE DEVELOPING OVER THE LEE SIDE OF THE ROCKIES TONIGHT AND MONDAY...WITH WINDS IN TURN SWITCHING AROUND TO THE SOUTH BY MONDAY MORNING. EXPECTING THE WINDS TO INCREASE THROUGH THE DAY AS THE PRESSURE GRADIENT TIGHTENS. AS THE RIDGE SHIFTS EAST...TEMPERATURES ALOFT WILL WARM ON MONDAY. CURRENT 700MB TEMPERATURES IN THE UPPER SINGLE DIGITS LOOK TO INCREASE TO 11-13C BY 00Z TUESDAY SO SHOULD HAVE THE POTENTIAL FOR A SLIGHTLY WARMER DAY FOR MOST LOCATIONS FOR MONDAY WITH FORECAST HIGHS FROM AROUND 90 TO THE MID 90S NORTHEAST TO SOUTHWEST. MAINTAINED THE SLIGHT CHANCES FOR SHOWERS AND STORMS ACROSS THE NORTH AND WEST MONDAY AFTERNOON. A SHORTWAVE MOVES TOWARDS NEBRASKA IN THE AFTERNOON OUT OF WYOMING AND COLORADO...HOWEVER THE TIMING LOOKS BETTER WITH THIS INTO THE EVENING. THE MODELS DO CONTINUE TO DEVELOP PRECIPITATION OVER NORTHERN NEBRASKA IN THE AFTERNOON AS MOISTURE POOLS ALONG A BOUNDARY IN THE VICINITY OF THE NE/SD BORDER. DEWPOINTS RISE INTO THE UPPER 50S AND 60S AT THE SURFACE AND MID LEVEL MOISTURE INCREASES...AND WITH LOW LEVEL LAPSE RATES STAYING STEEP...PRECIPITATION CONTINUES TO LOOK POSSIBLE. INSTABILITY ISN/T GREAT...WITH MU VALUES BEING UP TO 1000 J/KG...BUT DEEP LAYER SHEAR WILL BE INCREASING SO COULD GET A FEW CELLS TO ORGANIZE IN THESE AREAS TO GET A FEW STRONGER STORMS. WIDESPREAD SEVERE WEATHER IS NOT ANTICIPATED. && .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 345 PM CDT SUN AUG 3 2014 A PATTERN SHIFT WILL LEAD TO A SURFACE LOW AND ASSOCIATED FRONTAL SYSTEM MOVING SOUTHEAST MONDAY THROUGH WEDNESDAY NIGHT. A HIGHER CHANCE FOR THUNDERSTORMS OCCURS TUESDAY NIGHT AS SEVERAL DISTURBANCES MOVE EAST. THE PRECIPITABLE WATER RATIOS WILL BE HIGHER WHERE HEAVY RAIN IS POSSIBLE WITH THUNDERSTORMS THAT MAY FORM. AS THE FRONT MOVES EAST AND SOUTH THURSDAY THE TRAILING END OF THE FRONT BACKS WEST AND NORTHWEST THROUGH THE WESTERN PANHANDLE. IF THE FRONT STALLS ACROSS NORTHERN KANSAS AS SHOWN...A PREVAILING EASTERLY SURFACE FLOW WOULD INCREASE THE MOISTURE SUPPLY FOR INCREASED CLOUDS INTO THE EXTENDED PERIOD. A CHANCE OF THUNDERSTORMS DAILY LINGERS AS THE STALLED BOUNDARY TO THE SOUTH WOULD KEEP TEMPERATURES CLOSER TO NORMAL...OR BELOW NORMAL ...GOING FORWARD WITH DAYTIME HIGHS IN THE 80S OVER THE SOUTHWEST...AND 70S IN THE NORTH AND NORTH CENTRAL. MODEL CONSENSUS DIVERGES BEYOND WEDNESDAY NIGHT WITH A SUPERBLEND OF THE SOLUTIONS USED. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 125 PM CDT SUN AUG 3 2014 HAVE INCLUDED VICINITY THUNDER IN THE FORECAST FOR KLBF LATER THIS AFTERNOON AS ISOLATD SHOWERS AND THUNDERSTORMS COULD DEVELOP IN THE AREA ALONG A WEAK SURFACE BOUNDARY. THINK COVERAGE WILL BE VERY ISOLATED AND LITTLE CONFIDENCE ON IMPACTS TO THE TERMINAL SO NO PREVAILING MENTION AT THIS TIME. LATER TONIGHT THUNDERSTORMS ARE POSSIBLE UP OVER NORTH CENTRAL NEBRASKA. HAVE HIGHER CONFIDENCE IN STORMS TO THE EAST OF THE KVTN TERMINAL SO WILL KEEP PREVAILING THUNDERSTORMS OUT OF THE FORECAST AT THIS TIME. OTHERWISE...LOOK FOR A SLOW SHIFT IN THE WINDS TO THE SOUTH BY LATE MORNING ON MONDAY. WILL LIKELY SEE WIND SPEEDS INCREASE INTO MONDAY AFTERNOON. && .HYDROLOGY... ISSUED AT 345 PM CDT SUN AUG 3 2014 ON THE NORTH PLATTE RIVER...FROM LAKE MCCONAUGHY DOWNSTREAM TO BRADY...IRRIGATION RELEASES CONTINUE TO SLOWLY CREEP UP THE FLOWS WITH THE CURRENT STAGE AT THE NORTH PLATTE GAGE AT 5.4 FEET. THE RIVER FORECAST FOR THE NORTH PLATTE GAGE...NEAR THE HIGHWAY 83 BRIDGE...IS FOR FLOWS TO REMAIN AROUND 5.5 FEET THROUGH THURSDAY. THERE IS A CHANCE FOR THUNDERSTORMS DAILY WHERE SOME FLUCTUATIONS ARE POSSIBLE. && .LBF WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...BROOKS SHORT TERM...BROOKS LONG TERM...KECK AVIATION...BROOKS HYDROLOGY...KECK
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
125 PM CDT SUN AUG 3 2014 .SYNOPSIS... ISSUED AT 326 AM CDT SUN AUG 3 2014 STARTING TO SEE SOME CHANGES IN THE UPPER LEVELS. THE MAIN WESTERN RIDGE AND EASTERN TROUGH CONTINUE...HOWEVER A CLOSED LOW ACROSS SRN CAL IS SHOWING SIGNS OF MOVING NORTH WHICH WILL EVENTUALLY FLATTEN THE RIDGE. THIS MOVEMENT OF THE LOW HAS NOT CHANGED ANYTHING FOR THE HIGH PLAINS YET...THUS THE EFFECTIVE WEATHER REMAINS SIMILAR TO THE PAST SEVERAL DAYS. NORTHWEST FLOW WITH NUMEROUS DISTURBANCES DRIFTING ACROSS THE AREA. THIS MORNING A COUPLE OF DISTURBANCES HAVE PUSHES SOUTH AND EAST OF THE CWA...WITH MORE OVER THE NORTHERN ROCKIES. CLEAR TO MOSTLY CLEAR SKIES HAVE ALLOWED FOR TEMPS TO COOL WITH SOME PATCHY FOG STARTING TO BE REPORTED IN THE EASTERN ZONES...WHERE HIGHEST DEW PTS ARE LOCATED. && .UPDATE... ISSUED AT 125 PM CDT SUN AUG 3 2014 CONTINUING TO WATCH POTENTIAL FOR THUNDERSTORMS THIS AFTERNOON. CURRENT LAPS SOUNDINGS SHOW A LACK OF MOISTURE IN THE MID LEVELS SO THERE IS CONCERN THAT EVEN WHEN REACHING PEAK HEATING AND FULL MIXING IN THE NEXT FEW HOURS THAT THERE WON/T BE ENOUGH MOISTURE TO ALLOW ANY DEVELOPMENT. THE LATEST RUNS OF THE RAP AND NAM INDICATE AN INCREASE IN 700-600MB MOISTURE THIS AFTERNOON AND THE 03.16Z HRRR CONTINUES TO DEVELOP SOME ISOLATED ACTIVITY IN THE VICINITY OF A WEAK SURFACE BOUNDARY FROM THE WESTERN SANDHILLS DOWN THROUGH SOUTH CENTRAL NEBRASKA. SO...DESPITE LOW CONFIDENCE WILL CONTINUE THE MENTION OF ISOLATED SHOWERS AND THUNDERSTORMS THIS AFTERNOON. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 326 AM CDT SUN AUG 3 2014 SOME PATCHY MORNING FOG WILL QUICKLY BURN OFF WITH MOSTLY SUNNY SKIES THIS MORNING. BY AFTERNOON TEMPS WILL WARM TO AROUND 90 WITH SOME LOWER TO MID 90S POSSIBLE. THIS WILL CREATE ENOUGH INSTABILITY FOR ANOTHER ROUND OF ISOLATED TO SCATTERED THUNDERSTORMS. A DISTURBANCE ACROSS EASTERN MONTANA/NORTHEAST WYOMING...SHOULD BE MOVING OVERHEAD AND ADD TO THE LIFT. SHEAR CONTINUES TO BE MARGINAL...AS IS CAPE...HOWEVER SEEING WHAT HAS OCCURRED THE PAST SEVERAL DAYS...A FEW STRONG STORMS ARE POSSIBLE. CANNOT TOTALLY RULE OUT A STRAY SEVERE STORM OR TWO. ONCE WE BEGIN TO COOL THIS EVENING...THE SHOWER ACTIVITY SHOULD BEGIN TO DIMINISH. SKIES SHOULD SEE DECREASING CLOUDS WITH TEMPS TO FALL INTO THE LOWER 60S...LOCALLY AN UPPER 50 READING POSSIBLE IN THE WEST BY MORNING. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 326 AM CDT SUN AUG 3 2014 A WARM START TO THE WORK WEEK WILL BE FOLLOWED BY A COOL DOWN WITH INCREASING CHANCES FOR RAIN BY MID INTO LATE WEEK. SURFACE HIGH PRESSURE WILL NOSE INTO THE GREAT LAKES FROM CANADA MONDAY AND TUESDAY. THIS WILL PUSH A COLD FRONT SOUTHWEST INTO THE AREA. MODELS AGREE THAT THE FRONT WILL BECOME STATIONARY FROM ROUGHLY THE NORTHERN NEBRASKA PANHANDLE...SOUTHEASTWARD THROUGH CENTRAL AND INTO EASTERN NEBRASKA. TO THE SOUTH OF THE BOUNDARY ACROSS THE SOUTHERN NEBRASKA PANHANDLE INTO SOUTHWEST NEBRASKA...IT WILL REMAIN WARM WITH HIGHS IN THE 90S. MEANWHILE EASTERLY WINDS AND POOLING MOISTURE TO THE NORTH OF THE FRONT ACROSS NORTHERN NEBRASKA WILL KEEP IT COOLER...WITH HIGHS FROM 80 TO 85 DEGREES. WILL CONTINUE THE SLIGHT CHANCE FOR STORMS ACROSS NORTHERN NEBRASKA MONDAY AFTERNOON NEAR THE FRONT...AND THEN INCREASE INTO THE CHANCE CATEGORY MONDAY NIGHT AS A SOUTHERLY LOW LEVEL JET DEVELOPS. A FAIRLY STRONG SHORTWAVE IS STILL ADVERTISED TO CROSS THE REGION TUESDAY AND TUESDAY NIGHT...WITH THUNDERSTORM CHANCES LOOKING PRETTY DECENT...ESPECIALLY ACROSS NORTHERN PORTIONS OF THE STATE. THIS SHORTWAVE WILL FORCE THE STATIONARY FRONT SOUTH INTO KANSAS WEDNESDAY...BRINGING COOLER HIGHS IN THE 80S INTO SOUTHWEST NEBRASKA AND PERHAPS ONLY UPPER 70S ACROSS THE NORTH. THE FRONT WILL REMAIN ACROSS KANSAS INTO LATE WEEK...WITH EAST TO SOUTHEAST MOIST UPSLOPE FLOW ACROSS CENTRAL AND WESTERN NEBRASKA. SOME CHANCE FOR CONVECTION EACH DAY...AS STORMS FIRE ON THE HIGHER TERRAIN TO THE WEST AND ATTEMPT TO MOVE EAST DURING THE AFTERNOONS AND EVENINGS. HIGHS WILL REMAIN NEAR OR SLIGHTLY BELOW NORMAL IN THE 80S...LOW TEMPERATURES HOWEVER WILL BE NEAR OR SLIGHTLY ABOVE NORMAL IN THE 60S DUE TO HIGHER HUMIDITY HELPING TO KEEP THE NIGHTS WARM. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 125 PM CDT SUN AUG 3 2014 HAVE INCLUDED VICINITY THUNDER IN THE FORECAST FOR KLBF LATER THIS AFTERNOON AS ISOLATD SHOWERS AND THUNDERSTORMS COULD DEVELOP IN THE AREA ALONG A WEAK SURFACE BOUNDARY. THINK COVERAGE WILL BE VERY ISOLATED AND LITTLE CONFIDENCE ON IMPACTS TO THE TERMINAL SO NO PREVAILING MENTION AT THIS TIME. LATER TONIGHT THUNDERSTORMS ARE POSSIBLE UP OVER NORTH CENTRAL NEBRASKA. HAVE HIGHER CONFIDENCE IN STORMS TO THE EAST OF THE KVTN TERMINAL SO WILL KEEP PREVAILING THUNDERSTORMS OUT OF THE FORECAST AT THIS TIME. OTHERWISE...LOOK FOR A SLOW SHIFT IN THE WINDS TO THE SOUTH BY LATE MORNING ON MONDAY. WILL LIKELY SEE WIND SPEEDS INCREASE INTO MONDAY AFTERNOON. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...BROOKS SYNOPSIS...MASEK SHORT TERM...MASEK LONG TERM...TAYLOR AVIATION...BROOKS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1226 AM CDT SUN AUG 3 2014 .SYNOPSIS... ISSUED AT 320 PM CDT SAT AUG 2 2014 THE WESTERN CONUS RIDGE/EASTERN CONUS TROUGH PATTERN CONTINUES IN THE UPPER LEVELS WITH THE CENTRAL PLAINS UNDER THE INFLUENCE OF NORTHWEST FLOW WITH WEAK SHORTWAVES PERIODICALLY MOVING OVER THE RIDGE AND ACROSS THE AREA AS THEY DIVE INTO THE TROUGH. AT 19Z...NOTING A SHORTWAVE TROUGH MOVING INTO NORTHERN SOUTH DAKOTA...WITH ANOTHER OVER SOUTHERN WYOMING. 02.12Z SOUNDINGS SHOWED 700MB TEMPERATURES OF 9C AND 8C AT KUNR AND KLBF RESPECTIVELY...WITH 5C AND 6C AT KABR AND KOAX. THIS WOULD INDICATE THAT ALTHOUGH THE AREA IS UNDER NORTHWEST FLOW...THE WARM AIR ALOFT UNDER THE RIDGE CONTINUES TO STAY IN PLACE ACROSS THE WESTERN PLAINS. HOWEVER...THIS AIR IS NOT WARM ENOUGH TO CAP THE BOUNDARY LAYER. AT THE SURFACE...LOW PRESSURE WAS SITUATED OVER SOUTH CENTRAL SOUTH DAKOTA...JUST NORTH AND EAST OF KVTN WITH A WEAK TROUGH OF LOW PRESSURE EXTENDING SOUTH THEN WEST /TO AROUND KBBW THROUGH KLBF AND KOGA. STRONG HEATING AT THE SURFACE WITH HIGHS IN THE UPPER 80S AND LOW 90S HAS CREATED DEEP MIXING UP TO 600MB AND WITH STEEP LAPSE RATES CONVECTION HAS BEGUN TO DEVELOP ACROSS THE AREA WHERE CONVERGENT BOUNDARIES EXIST. MU CAPES ARE 1500 TO 2000 J/KG BUT THERE IS VERY LITTLE SHEAR OVER ONGOING CONVECTION SO ACTIVITY HAS BEEN VERY UNORGANIZED THUS FAR THIS AFTERNOON. && .UPDATE... ISSUED AT 828 PM CDT SAT AUG 2 2014 THUNDERSTORMS IN SOUTH CENTRAL SOUTH DAKOTA ARE PRODUCING LARGE HAIL...SO WE HAVE UPDATED THE FORECAST FOR NORTH CENTRAL NEBRASKA TO INCLUDE THE POSSIBILITY OF SEVERE THUNDERSTORMS. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 320 PM CDT SAT AUG 2 2014 SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH THE AFTERNOON AND INTO THIS EVENING UNTIL LOSS OF DAYTIME HEATING STABILIZES THE BOUNDARY LAYER AND CUTS OFF THE ENERGY INTO THE STORMS. THE SURFACE LOW OVER SOUTH DAKOTA WILL SLOWLY MOVE SOUTHEAST THROUGH THE EVENING WITH THE PRECIPITATION GENERALLY STAYING ALONG AND SOUTH OF AN ARC FROM THE LOW TO KTIF TO KAIA. PRECIPITATION CHANCES WILL SLIDE SOUTH AND EAST THROUGH THE EVENING...AND SHOULD GENERALLY BE DONE BY 06Z. THE RAP AND THE NAM DO INDICATE AN INCREASE IN DEEP LAYER SHEAR AS A SHORTWAVE TROUGH OVER THE DAKOTAS SLIDES SOUTHEAST THIS EVENING. IS NOT OUT OF THE QUESTION TO GET AN ISOLATED STORM THAT IS ABLE TO GET ORGANIZED AND PRODUCE HAIL OR STRONG WINDS...BUT FEEL IT WILL BE SHORT LIVED AND NO REAL THREAT FOR SEVERE STORMS IS CURRENTLY A CONCERN. AS THE SHORTWAVE OVER SOUTH DAKOTA MOVES SOUTHEAST INTO NORTHERN NEBRASKA LATER THIS EVENING AND OVERNIGHT THERE ARE INDICATIONS OF WARM AIR ADVECTION AND STRONGER LIFT AHEAD OF IT...ALONG WITH MOISTURE TRANSPORT IN THE 850MB TO 700MB LAYER. ALTHOUGH NONE OF THIS IS REAL STRONG COULD GET MORE CONVECTION TONIGHT. IF IT DOES DEVELOP...ONE QUESTION WILL BE HOW FAR WEST IT WILL BE. CURRENT SUITE OF MODELS SHOW MOST OF THIS ACTIVITY WILL JUST SKIRT THE LOCAL FORECAST AREA...MAINLY KEEPS IT OVER NORTHEAST NEBRASKA. THEN FOR SUNDAY...NOT MUCH CHANGE IN THE GENERAL WEATHER PATTERN. TEMPERATURES ALOFT WARM SLIGHTLY BUT NOT MUCH SO STILL LOOKING FOR HIGHS NEAR 90 OR IN THE LOW 90S MOST LOCATIONS. WITH THE EXCEPTION OF THE GFS...MODELS ARE ALL DEVELOPING CONVECTION IN THE AFTERNOON ALONG A WEAK SURFACE FRONT FROM NORTHWEST TO SOUTH CENTRAL NEBRASKA. STRONG DAYTIME HEATING WILL AGAIN DESTABILIZE THE LOW LEVELS OF THE TROPOSPHERE AND WILL CREATE STEEP LAPSE RATES WITH MIXING TO NEAR 650MB. ALSO...THERE IS A WEAK SHORTWAVE PROJECTED TO MOVE INTO NORTHWEST NEBRASKA NEAR MID AFTERNOON TO ENHANCE THE LIFT IN THE AREA. AS SIMILAR CONDITIONS OVER THE PAST SEVERAL DAYS HAVE CAUSED DEVELOPMENT OF ISOLATED TO SCATTERED SHOWER AND THUNDERSTORM ACTIVITY SEE NO REASON WHY IT WON/T OCCUR AGAIN SUNDAY AFTERNOON AND HAVE ADDED CHANCES FOR PRECIPITATION INTO THE FORECAST. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 320 PM CDT SAT AUG 2 2014 SUNDAY NIGHT...WRN STATES UPPER RIDGE AXIS BUILDS EWD AS UPPER LOW OVER SERN CANADA ALSO SHIFTS EWD. SURFACE HIGH PRESSURE BEGINS TO SLIDE SWD INTO THE GREAT LAKES AND UPPER MISSISSIPPI VALLEY WHICH ALLOWS A WEAK BOUNDARY TO BACK WWD INTO THE NERN PORTION OF THE FCST AREA SUNDAY NIGHT INTO MONDAY. AS THIS HAPPENS...LEE SIDE LOW PRESSURE REDEVELOPS ACROSS THE NRN HIGH PLAINS SETTING UP A BAROCLINIC ZONE ALONG THE PERIPHERY OF THE ERN SIDE OF THE UPPER RIDGE AXIS...ACROSS THE DAKOTAS AND NRN NEBRASKA. THE ULTIMATE PLACEMENT OF THIS FRONTAL BOUNDARY WILL BE KEY TO THE PRECIPITATION FCST THROUGH THE WEEK AND IS DISCUSSED FURTHER BELOW. MODELS ARE SIMILAR WITH THIS PLACEMENT BY MONDAY THOUGH DIFFER BEYOND. THE NRN PORTION OF THIS BOUNDARY BECOMES CO-LOCATED WITH AN AREA OF MID LEVEL FRONTOGENESIS SUNDAY EVE WHICH WILL HELP TO GENERATE DEEP LAYER LIFT AND A BETTER CHC OF THUNDERSTORMS NORTH OF NEB SUNDAY EVE. HOWEVER...UPPER NW FLOW HAS GENERATED ISOLATED THUNDERSTORMS IN THE CURRENT PATTERN DUE TO WEAK BOUNDARY INTERACTIONS AND STEEP LAPSE RATES ALOFT...AND WOULD EXPECT A SIMILAR SCENARIO FOR SUNDAY EVE FURTHER SOUTH INTO WESTERN AND NORTH CENTRAL NEB...AND THEREFORE SLIGHT CHANCES FOR THUNDERSTORMS WILL BE IN THE FCST BEFORE MIDNIGHT SUNDAY. MIN TEMPS SUNDAY NIGHT NEAR TO SLIGHTLY ABOVE AVERAGE FOR THIS TIME OF YEAR. MONDAY INTO TUESDAY THE SHIFT IN THE RIDGE AXIS ALONG THE FRONT RANGE ALLOWS SUBSIDENCE AND DRYING TO OCCUR OVER THE HIGHER TERRAIN FURTHER WEST. THIS IN TURN WILL ALLOW FOR A RETURN OF THE NOCTURNAL HIGH PLAINS LLJ WHICH DEVELOPS IN RESPONSE TO THE MORE RAPID COOLING OF THE HIGHER TERRAIN IN THE EVENING COMPARED TO A MORE MOIST ATMOSPHERE FURTHER EAST. THIS LLJ ALSO STRENGTHENS IN RESPONSE TO UPPER PV ANOMALIES ROUNDING THE NOW FLATTENED RIDGE WITH ASSOCIATED SFC CYCLOGENESIS FAVORING THE WY/CO FRONT RANGE AND WRN HIGH PLAINS BY MID WEEK. THIS ALL SETS THE STAGE FOR INCREASED THUNDERSTORM DEVELOPMENT...ESPECIALLY DURING THE LATE EVENING AND OVERNIGHT HOURS...MONDAY AND TUESDAY AND ON INTO THE REST OF THE WEEK. THE PREVIOUSLY MENTIONED FRONTAL BOUNDARY CONTINUES TO SAG FURTHER SWD AND EVENTUALLY ACROSS THE WESTERN AND NORTH CENTRAL PORTION OF NEBRASKA DURING MID WEEK. THE LLJ WILL BE EFFICIENT AT SUPPLYING LOW LEVEL MOISTURE TO THE ATMOSPHERE WHICH WILL BE FURTHER ENHANCED BY TROPICAL MOISTURE MOVING NWD THROUGH THE GREAT BASIN AREA AROUND THE AFOREMENTIONED UPPER HIGH. THE RESULT IS PW VALUES APPROACHING +2 STANDARD DEVIATIONS ABOVE THE MEAN FOR THIS TIME OF YEAR...NEARING 1.75 INCHES BY THU. IN ADDITION...MODEST INSTABILITY DEVELOPS E OF THE STATIONARY/WARM FRONTAL BOUNDARY IN ERN NEB EARLY IN THE WEEK BUT SHIFTS SWWD BY WED/THU TIME FRAME AS DOES THE BOUNDARY. THE SPECIFIC DETAILS OF BOUNDARY LOCATION FROM DAY TO DAY WILL BE DETERMINED LARGELY BY EACH ITERATION OF CONVECTIVE DEVELOPMENT AS MESOSCALE COLD POOL AUGMENTATION OF THE BOUNDARY TAKES PLACE...MAKING SPECIFIC DETAILS OF THUNDERSTORM DEVELOPMENT DIFFICULT. IN GENERAL...THE DEVELOPING LARGE SCALE PATTERN BY MID WEEK SUPPORTS AN INCREASED CONFIDENCE IN INCREASING THUNDERSTORM CHANCES THROUGH THE WEEK. DAYTIME MAX TEMPERATURES WILL BE AVERAGE TO SLIGHTLY ABOVE TO START THE WEEK...BUT WILL LOWER TO BELOW AVERAGE BY THE END OF THE WEEK. THE DIURNAL RANGE OF TEMPS AS THE WEEK PROGRESSES HOWEVER LESSENS WITH LOWS REMAINING NEAR OR ABOVE AVERAGE THROUGH THE WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1226 AM CDT SUN AUG 3 2014 ISOLATED THUNDERSTORMS IN NORTH CENTRAL NEBRASKA...AROUND ONL...WILL DISSIPATE BY 10Z. AFTER THAT...RESIDUAL MOISTURE FROM THE RAIN COULD RESULT IN AREAS OF FOG WITH LOCALIZED VISIBILITY LESS THAN 1SM. HOWEVER...THE SHORT RANGE PROJECTIONS INDICATE THAT IT WILL BE NORTH AND EAST OF A VTN-TIF-BBW LINE. WITH NO SIGNIFICANT CHANGE IN THE WEATHER PATTERN...ISOLATED THUNDERSTORMS CAN BE EXPECTED AGAIN SUNDAY EVENING. HOWEVER...WITH MUCH UNCERTAINTY IN THE LOCATION AND TIMING...THEY WILL NOT BE INCLUDED IN THE TERMINAL FORECASTS FOR LBF AND VTN AT THIS TIME. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SPRINGER SYNOPSIS...BROOKS SHORT TERM...BROOKS LONG TERM...JWS AVIATION...SPRINGER
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1147 PM MDT SAT AUG 2 2014 .AVIATION... 06Z TAF CYCLE SHRA AND ISOLATED LOW-TOPPED TSRA OVER FAR SW NM JUST AROUND 06Z SHOULD EXPAND IN COVERAGE AND SLOWLY TRACK NORTH DURING THE OVERNIGHT INTO SUNDAY AM. ENOUGH CONFIDENCE TO INCLUDE A MENTION AT KGUP AFTER DAYBREAK GIVEN GOOD RUN-TO-RUN CONSISTENCY IN MODELS....BUT LOWER CONFIDENCE ON PRECISE TIMING AND HAVE TARGETED 14Z-15Z AS FIRST GUESS. ELSEWHERE... WEAK UPSLOPE REGIME THAT HAD BEEN IN PLACE EAST OF THE CENTRAL MOUNTAIN CHAIN HAS YIELDED SOME VERY SPOTTY LIGHT SHOWERS AT KLVS AS WELL AS NEAR KROW PAST FEW HOURS. WILL NOT INCLUDE A VC PLACEHOLDER AT EITHER SITE THOUGH VFR MID LEVEL CIGS MAY LINGER A LITTLE LONGER THAN EXPECTED...ESPECIALLY KROW. OTHERWISE...TRENDED KFMN...KSAF AND ABQ AREA TERMINAL FORECASTS TO REFLECT AN INCREASE IN MAINLY MID-LEVEL CLOUD COVER AFT 12Z BEFORE DIURNAL TRENDS PREDOMINATE AFTER 18Z. FOCUS FOR CONVECTION SUN PM WILL AGAIN BE ACROSS THE WEST... WITH A MORE ACTIVE ROUND OF SHRA/TSRA AS COMPARED TO SATURDAY. KJ && .PREV DISCUSSION...300 PM MDT SAT AUG 2 2014... .SYNOPSIS... ABUNDANT MOISTURE WILL LINGER OVER NEW MEXICO THROUGH EARLY NEXT WEEK...AND SLOW MOVING STORMS WILL CONTINUE TO BE CAPABLE OF PRODUCING LOCALLY HEAVY RAIN...WHICH COULD LEAD TO FLASH FLOODING. AREAS ALONG AND WEST OF THE CONTINENTAL DIVIDE WILL BE THE FOCUS FOR THE HEAVIER STORMS TONIGHT AND INTO SUNDAY...WHILE THE FOCUS SLOWLY SHIFTS TO THE NORTHWEST THIRD TO HALF SUNDAY NIGHT...AND PORTIONS OF THE WEST AND CENTRAL MONDAY. HIGH TEMPERATURES WILL REMAIN BELOW AVERAGE THROUGH MONDAY. A WARMING AND DRYING TREND IS EXPECTED BY THE MIDDLE OF NEXT WEEK. && .DISCUSSION... ABUNDANT CLOUD COVER LINGERING THIS AFTERNOON...AND LAPS SHOWING THE EAST REMAINING STABLE SO FAR. CELLS HAVE BEEN FIRING ALONG/WEST OF THE CENTRAL MT CHAIN AND MOST NOTABLY OVER WESTERN SOCORRO COUNTY TO THE GALLUP AREA...BUT LESS ACTIVE OVERALL COMPARED TO THIS TIME THE LAST COUPLE OF DAYS. PWATS FROM AREA 12Z SOUNDINGS SHOWED LITTLE CHANGE FROM FRIDAY ALTHOUGH MID LEVEL WINDS ARE TRANSITIONING AS THE WEAK UPPER LOW PREPARES TO MOVE NORTH INTO ARIZONA. INITIAL THOUGHTS WERE THAT THE CURRENT FLASH FLOOD WATCH MAY HAVE NEEDED TO BE EXPANDED NORTHWARD AND SOMEWHAT EASTWARD FOR TONIGHT...BUT 12Z LOCAL WRF...NAM AND HRRR DON/T SUPPORT THAT IDEA AND ARE RATHER SPARSE LOOKING IN AREAL COVERAGE. THEREFORE DECIDED TO LET THE CURRENT WATCH RIDE...WHERE MOST OF THIS AFTERNOON/S ECHOS EXIST SO FAR. SUNDAY/SUNDAY EVENING COULD BE QUITE ACTIVE ALONG AND WEST OF THE CONTINENTAL DIVIDE AND CAN/T RULE OUT THE POTENTIAL FOR HEAVY RAIN OVER THAT AREA...HOWEVER STORM MOTION LOOKS TO BE GENERALLY SOUTH TO NORTH AT 10 TO 15 MPH. MODELS SUGGEST THE EAST WILL CONTINUE TO BE FAIRLY QUIET. AS THE UPPER LOW MOVES INTO THE GREAT BASIN MONDAY...THE THETA-E RIDGE AXIS SHIFTS MORE SOUTHWEST TO NE OVER NEW MEXICO...PUTTING THE FOCUS FOR STORMS MORE INTO THE NORTHWEST AND NORTH CENTRAL AND ALLOWING THEM TO DRIFT OFF THE MTS INTO THE NORTHEAST AND CENTRAL HIGHLANDS. THE MID TO LATE WEEK PERIOD STILL FEATURES A SUPPRESSION OF THE RIDGE...ALLOWING THE NORTHWEST TO DRY OUT SOME...AND A DECREASE OVERALL IN CONVECTION. HIGH TEMPERATURES SHOULD FINALLY EXPERIENCE A REBOUND TOWARDS NORMAL FOR THE FIRST WEEK OF AUGUST. && .FIRE WEATHER... A WET AND ACTIVE MONSOON PATTERN WILL CONTINUE OVER THE NEXT FEW DAYS...KEEPING CRITICAL FIRE WEATHER CONDITIONS FROM DEVELOPING. FOOTPRINTS OF WETTING RAINFALL HAVE BEEN SCATTERED EACH DAY OVER THE PAST WEEK...BUT MOST AREAS OUTSIDE OF THE EASTERN PLAINS HAVE SEEN PRECIPITATION ON OCCASION. WINDS WILL REMAIN LIGHT FOR THE MOST PART...ONLY GETTING SLIGHTLY BREEZY IN THE VICINITY OF CENTRAL GAPS/CANYONS THIS EVENING...AND OF COURSE GUSTY WITH ANY BRIEF AND LOCALIZED THUNDERSTORM OUTFLOWS. THE FOCUS FOR STORMS WILL BE IN SOUTHWESTERN SECTIONS OF THE FORECAST AREA TODAY AND TONIGHT...SHIFTING TO THE WESTERN THIRD OF THE STATE SUNDAY. THE BEST PLUME OF MOISTURE ALOFT WILL THEN BEGIN TO GRADUALLY LAY OVER OR TOPPLE TO MORE OF A SOUTHWEST-NORTHEAST ORIENTATION MONDAY AND TUESDAY...WITH STORMS STRETCHING FROM THE SW MOUNTAINS TO THE NORTHERN MOUNTAINS BOTH DAYS. STORMS WILL ALSO PERIODICALLY BE FILLING IN BETWEEN THESE AREAS. SOME LEE SIDE SURFACE TROUGHING WILL ALLOW MODERATE BREEZES TO DEVELOP IN THE NORTHEAST MONDAY AND TUESDAY. OVERALL HUMIDITY TRENDS WILL NOT VARY MUCH THROUGH THE NEXT FEW DAYS WITH GOOD TO EXCELLENT RECOVERIES IN MUCH OF THE FORECAST AREA EACH NIGHT/MORNING...ESPECIALLY WITHIN AREAS THAT RECEIVE WETTING RAIN. BELOW AVERAGE TEMPERATURES ARE ALSO EXPECTED TO CONTINUE THROUGH TUESDAY...KEEPING DAYTIME HUMIDITY FAIRLY ELEVATED THROUGH TUESDAY. SOME DAY-TO-DAY DRYING IS THEN EXPECTED WEDNESDAY THROUGH THE END OF NEXT WEEK. THIS WILL ALLOW TEMPERATURES TO START CLIMBING BACK TO NEAR AVERAGE FOR EARLY AUGUST. 52 && .ABQ WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH UNTIL 6 AM MDT SUNDAY FOR THE FOLLOWING ZONES... NMZ505-506-508-509-520. && $$
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1013 PM EDT MON AUG 4 2014 .SYNOPSIS... A WEAK FRONT WILL REMAIN ALONG THE NORTH CAROLINA COAST THROUGH TUESDAY. HURRICANE BERTHA WILL REMAIN WELL OFFSHORE OF THE SOUTHEAST COAST THROUGH TUESDAY...THEN LIFT OFF TO THE NORTHEAST TUESDAY NIGHT AND WEDNESDAY. A COLD FRONT WILL DROP THROUGH THE AREA ON THURSDAY THEN REMAINED STALLED TO THE SOUTH THROUGH THE WEEKEND. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... AS OF 1010 PM MONDAY...LATEST MESOANALYSIS SHOWING AXIS OF HIGHEST PRECIPITABLE WATER NOW MOVING OFFSHORE AND ONLY A FEW ISOLATED SHOWERS REMAIN ON LAND IN OUR CENTRAL CWA. CONFIDENCE HIGH IN LOWERING POPS TO LOW CHANCE OVERNIGHT WITH BEST COVERAGE JUST OFFSHORE. LATEST 3KM HRRR DOES INDICATE SOME SHOWERS APPROACHING THE COAST MOVING ONSHORE DURING THE MORNING HOURS...BUT COVERAGE LOOKS TO BE APPRECIABLY LESS THAN IN RECENT DAYS. GIVEN LIGHT WINDS AND WET GROUND...LIKELY TO SEE SOME PATCHY DENSE FOG WELL INLAND LATER. FORECAST LOWS IN THE LOW/MID 70S STILL LOOK GOOD. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/... AS OF 315 PM MON...BOUNDARY SHOULD GRADUALLY DISSIPATE OR MOVE FURTHER OFFSHORE...AS HURRICANE BERTHA LIFTS NE WELL OFFSHORE OF THE NC COAST. ONLY SIG IMPACTS STILL EXPECTED TO BE INCREASED ROUGH SURF AND ENHANCED RIP CURRENT THREAT. THINK WE WILL FINALLY BEGIN TO SEE A DRYING TREND A PERHAPS A FEW BREAKS IN THE CLOUDS. WILL CONTINUE CHANCE POPS THROUGH THE DAY...WITH BEST CHANCES ALONG THE COAST EARLY TRANSITIONING TO MORE INLAND DURING THE AFTERNOON WITH DAYTIME HEATING. THOUGH STILL SOME UNCERTAINTY REGARDING COVERAGE...LIKELY MUCH MORE SCATTERED THAN PAST SEVERAL DAYS. LOW LEVEL THICKNESS VALUES SUPPORT HIGHS IN THE LOW TO MID 80S...THOUGH COULD SEE SOME UPPER 80S IF SPOTS GET SOME SUNSHINE. && .LONG TERM /TUESDAY NIGHT THROUGH MONDAY/... A MOST WELCOME DRIER PATTERN WILL BE DEVELOPING MIDWEEK AS A ZONAL MID LEVEL FLOW DEVELOPS AND THE LOW LEVEL FLOW BECOMES WESTERLY AS HURRICANE BERTHA PASSES WELL OFF THE COAST IN THE WESTERN ATLANTIC. AFTER THE CHANCE OF A FEW SHOWERS AND TSTORMS LINGERING INTO TUE EVE, HAVE REMOVED POPS THRU WEDNESDAY EXCEPT FOR ISOLATED AFTERNOON/EARLY EVENING CONVECTION ALONG SEA BREEZE. TEMPS ON WEDNESDAY WILL REBOUND TO AROUND 90 DEGS AWAY FROM THE COAST WITH PLENTY OF SUNSHINE AND RISING LOW LEVEL THICKNESS IN MILD WSW FLOW. COMPLICATIONS IN THE FORECAST BEGIN WED NIGHT INTO THU AS A SHARP UPPER TROF DROPS THRU THE NE STATES AND PROPELS A SFC FRONT THRU THE AREA. THERE ARE TIMING ISSUES ON THE FRONTAL PASSAGE BUT A CONCENSUS SOLUTION WOULD ALLOW FOR A LATER ARRIVAL AND MORE SUNSHINE ACROSS SOUTHERN AREAS WHICH MAY ALLOW HIGHS TO REACH TO NEAR 90 DEGREES THERE. HIGHS OVER THE NORTH WILL LIKELY BE LIMITED TO THE LOW TO MID 80S GIVEN THE EARLIER FROPA. MODELS ARE ALSO SUGGESTING A MAINLY DRY FRONTAL PASSAGE GIVEN IN THE DRY WNW FLOW ALOFT BUT CONVERGENCE ALONG THE BNDRY MAY POPS A FEW SHOWERS OR STORMS POSSIBLY BEGINNING AS EARLY AS LATE WED NIGHT AND INTO THU WITH THE BEST PRECIP CHANCES OVER SOUTHERN AND EASTERN AREAS WITH FROPA COINCIDING WITH DIURNAL HEATING. FOR THE LATE WEEK FORECAST PERIOD AND BEYOND THE FORECAST BECOMES EVEN MORE UNCERTAIN. THE FRONT WILL SLOW DOWN MOVING SOUTH OF THE FORECAST AREA THU NIGHT AND FRIDAY AND WILL EVENTUALLY STALL OUT OVER THE SOUTHEAST STATES AS IT COMES UNDER PARALLELING STEERING FLOW. WAVES OF LOW PRESSURE WILL FORM ON THE BNDRY AS WEAK SHORT WAVE ENERGY FEEDS WEAK UPPER TROF DEVELOPING OVER THE SE STATES. TIMING OF THE WAVES OF LOW PRESSURE AND SUBSEQUENT PRECIP CHANCES ARE DIFFICULT AS THIS TIME RANGE. FOR NOW HAVE KEEP SLIGHT TO LOW CHANCE POPS IN THRU THE WEEKEND AND INTO EARLY NEXT WEEK WITH THE BEST CHANCES ACRS SOUTHERN AREAS. LATER MODELS RUNS SHOULD HELP SORT OUT FORECAST DETAILS BUT TEMPS WILL LIKELY AVERAGE BLO NORMAL WITH THE STALLED FRONT TO THE SOUTH THROUGH THE WEEKEND. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... SHORT TERM /THROUGH 18Z TUESDAY/... AS OF 7 PM MONDAY...AGAIN A MIXED BAG OF AVIATION CONDITIONS. CURRENTLY VFR WELL INLAND AT KPGV AND KISO WITH MVFR CLOSER TO THE COAST WITH A FEW PATCHY SHOWERS OCCURRING IN THE CENTRAL COUNTIES. GIVEN THE VERY WET GROUND AND RELATIVELY LIGHT WINDS...WILL AGAIN FORECAST MVFR AND PERHAPS OCCASIONAL IFR CONDITIONS OVERNIGHT...IMPROVING TO VFR WITH BETTER MIXING BY MID-MORNING ON TUESDAY. LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... TEMPO SUB VFR CONDITIONS IN ANY PRECIP THAT MAY LINGER INTO TUESDAY. ALSO MAY SEE SOME FOG LATE TUESDAY NIGHT WITH CLEARING SKIES AND LIGHT/CALM WINDS OVER WET GROUND. THE AIRMASS IS FORECAST TO GRADUALLY DRY OUT DURING MIDWEEK WITH PREDOMINATE VFR CONDITIONS RETURNING BY WED AND INTO EARLY THU. A COLD FRONT THEN PUSHES SOUTH THROUGH THE AREA THU WITH SLIGHT TO LOW CHANCES FOR SHOWERS AND THUNDERSTORMS AND SUB-VFR FLYING CONDITIONS. THE FRONT IS EXPECTED TO STALL SOUTH OF THE AREA THU NIGHT AND FRIDAY. EXPECT MAINLY VFR FOR THE LATE WEEK FORECAST PERIOD AND INTO EARLY NEXT WEEKEND AS HIGH PRESSURE BUILDS IN FROM THE NORTH. HOWEVER WAVES OF LOW PRESSURE RIDING ALONG THE FRONT MAY BRING PERIODS OF PRECIPITATION AND LOWERED CIGS/VSBYS THRU SATURDAY. && .MARINE... SHORT TERM /THROUGH TUESDAY/... AS OF 1010 PM MONDAY...MINIMAL CHANGES TO CURRENT MARINE FORECAST. SHOULD SEE GENERALLY SE WINDS BECOMING E AND REMAINING 10 TO 15 KNOTS OR LESS. SEAS WILL BE 2 TO 4 FEET INITIALLY BUT WILL INCREASE TO 4 TO 6 FEET LESS AS 12-13 SECOND SWELL ENERGY FROM DISTANT HURRICANE BERTHA AFFECTS THE CENTRAL AND NORTH COAST THEN SPREADS SOUTH LATE. EXPECT SEAS TO PEAK 6-9FT TUE AFTERNOON...THOUGH EXPECT WINDS THROUGH THE PERIOD LESS THAN 15KT. LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... SMALL CRAFT ADVISORY CONDITIONS FOR SEAS ASSOCIATED WITH TROPICAL CYCLONE BERTHA WELL OFF OF THE COAST WILL BE ENDING TUESDAY NIGHT OR EARLY WEDNESDAY. LIGHT NW WINDS TUESDAY NIGHT WILL BECOME SW AND INCREASE TO AROUND 15 KTS WED AND WED NIGHT AHEAD OF A COLD FRONT SET TO CROSS THE MARINE AREA ON THURSDAY. POSTFRONTAL N/NE FLOW AT 15 KTS OR LESS THU NIGHT AND FRIDAY WILL DIMINISH AND BECOMES EAST INTO THE EARLY PART OF THE WEEKEND AS THE FRONT SETTLES TO THE SOUTH OF THE AREA. SEAS MAY BUILD TO 3-5 FT AGAIN IN THE STRENGTHENING SW FLOW WEDNESDAY THEN VERY SLOWLY SUBSIDE TO 2-3 FT BY SATURDAY. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...SMALL CRAFT ADVISORY FROM 2 AM TUESDAY TO 5 AM EDT WEDNESDAY FOR AMZ152-154. SMALL CRAFT ADVISORY FROM 2 AM TUESDAY TO 2 AM EDT WEDNESDAY FOR AMZ156-158. SMALL CRAFT ADVISORY FROM 5 AM TUESDAY TO 5 AM EDT WEDNESDAY FOR AMZ150. && $$ SYNOPSIS...CQD NEAR TERM...CTC SHORT TERM...CQD LONG TERM...BTC AVIATION...CTC/BTC/BM MARINE...CTC/BTC
AREA FORECAST DISCUSSION
NWS RALEIGH NC
156 PM EDT SUN AUG 3 2014 .SYNOPSIS...A SLOW MOVING UPPER LEVEL TROUGH OVER THE TENNESSEE VALLEY COUPLED WITH A STATIONARY SURFACE BOUNDARY STRETCHING SOUTH TO NORTH OVER COASTAL CAROLINAS WILL MAINTAIN A MOIST AND UNSETTLED WEATHER PATTERN OVER MOST OF CENTRAL NC THROUGH MONDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1015 AM SUNDAY... UPPER LEVEL TROUGH REMAINS WEST OF THE AREA WITH UPPER LEVEL LOW PRESSURE CENTERED OVER THE OHIO VALLEY. UPPER AIR ANALYSIS FROM 12Z SHOWS SHEAR AXIS ASSOCIATED WITH SHORTWAVE EXTENDING DOWN THROUGH TENNESSEE. THIS WAVE WILL MOVE INTO THE NW PIEDMONT LATER TODAY AND HOPEFULLY WILL ACT AS AN ERODING MECHANISM TO BEGIN BREAKING UP THE CAD WEDGE...AT LEAST THE TRIAD. TIMING OF THIS FEATURE WILL BE TOUGH BUT THE RAP HAS IT MAKING HEADWAY INTO THE TRIAD BY EARLY AFTERNOON WITH A SUBSEQUENT DROP IN DEWPOINTS AND RELATIVE HUMIDITY. THEREFORE EXPECTING A SIMILAR DEPICTION OF THE PRECIP TO WHAT THE RADAR IS SHOWING NOW WHICH IS A VERY DEFINITIVE LINE OF PRECIP IN THE COASTAL PLAIN WITH MUCH DRIER CONDITIONS WEST OF I-95. THAT BEING SAID...THE TRIANGLE AREA WILL PROBABLY STAY CLOUDY FOR MUCH OF THE DAY WITH ONLY THE NW PIEDMONT HAVING A REAL CHANCE OF BREAKING OUT THIS AFTERNOON. THIS WILL MAKE TEMPERATURES TRICKY WITH AN ABNORMAL DISTRIBUTION OF WARMEST TEMPERATURES IN THE NW AND COOLEST IN THE SOUTHEAST. IF THE CAD BREAKS DOWN...COULD EASILY SEE LOWER 80S IN THE TRIAD WITH POSSIBLY ONLY MID 70S IN THE SOUTHEAST. THE GREATEST THREAT FOR PRECIPITATION WILL BE IN THE EXTREME SOUTHEAST TODAY WITH SAMPSON COUNTY BEING MONITORED AT THIS TIME FOR POTENTIAL URBAN AND SMALL STREAM FLOODING. KLTX RADAR INDICATES BETWEEN 2 AND 3 INCHES OF RAIN FALLEN IN THIS LOCATION ALREADY WITH SOME FURTHER TRAINING OF MODERATE TO HEAVY RAIN POSSIBLE OVER THE NEXT FEW HOURS. THE FLOOD WATCH REMAINS IN EFFECT THROUGH 00Z MONDAY FOR THE EASTERN TIER OF COUNTIES. NOT EXPECTING MUCH IN THE WAY OF SEVERE WEATHER THIS AFTERNOON ALTHOUGH THERE WILL BE SOME DECENT INSTABILITY IN THE EAST...SHEAR VALUES HAVE DROPPED OFF SIGNIFICANTLY BUT ARE STILL AT A MODEST 25 KTS. AS IN PREVIOUS DAYS...THE EXTENSIVE OVERCAST AND LACK OF INSOLATION SHOULD INHIBIT MOST THUNDERSTORM ACTIVITY THIS AFTERNOON. IF SOME CLEARING DOES OCCUR IN THE TRIAD...CAN EXPECT ANOTHER ROUND OF POTENTIALLY DENSE FOG OVERNIGHT. ELSEWHERE A PERSISTENCE FORECAST OF LIFR/IFR CEILINGS WILL PROBABLY WORK OUT WELL. THERE SHOULD BE A LULL IN PRECIPIATION AS PRECIPITATION BEGINS TO PUSH EASTWARD OFFSHORE. LOW TEMPERATURES TONIGHT MID 60S NW TO NEAR 70 SE. && .SHORT TERM /MONDAY AND MONDAY NIGHT/... AS OF 420 AM SUNDAY... STILL A DECENT THREAT FOR ADDITIONAL SHOWERS AND STORMS OVER OUR EASTERN PERIPHERY AS MID-UPPER LEVEL SHEAR AXIS WITHIN THE MOISTURE PLUME ONLY DRIFTS SLOWLY EWD. PLAN TO HAVE LIKELY POPS OVER THE COASTAL PLAIN AND SANDHILLS...TAPERING TO A SMALL CHANCE IN THE WESTERN PIEDMONT. AFTER MORNING LOW CLOUDS AND FOG BURN-OFF...EXPECT PARTIAL SUNSHINE ACROSS THE PIEDMONT. THIS SHOULD WARM TEMPS INTO THE LOW-MID 80S. A SURFACE WAVE LIFTING NEWD JUST OFFSHORE WILL MAINTAIN A THREAT FOR SHOWERS ACROSS THE COASTAL PLAIN THROUGH THE OVERNIGHT HOURS. AGAIN...SHOULD SEE AREAS OF LOW CLOUDS AND/OR FOG DEVELOP. MIN TEMPS MID 60S TO AROUND 70. && .LONG TERM /TUESDAY THROUGH SATURDAY/... AS OF 320 AM SUNDAY... TUESDAY THROUGH WEDNESDAY NIGHT: HIGHER PW`S ARE EXPECTED TO PUSH TO THE EAST OF THE AREA DURING THE PERIOD AS WE CONTINUE TO TRANSITION TO MORE OF A TYPICAL SUMMERTIME PATTERN. MID LEVEL TROUGHING ACROSS THE EASTERN U.S. WILL REMAIN THOUGH... WITH A LEE SIDE TROUGH DEVELOPING/BECOMES MORE ESTABLISHED OVER THE AREA. THIS WILL LEAD TO MORE OF A SLIGHT CHANCE/LOW END CHANCE OF SHOWERS AND STORMS FOR TUESDAY... WITH EVEN A LESSER CHANCE ON WEDNESDAY (BEST CHANCE ACROSS THE EAST). GIVEN THE DRIER MID LEVEL AIR EXPECTED TO MOVE INTO THE AREA DURING THIS TIME... EXPECT WE SHOULD SEE MORE INCOMING SOLAR RADIATION... RESULTING IN WARMING TEMPS BOTH DAYS AS AFTERNOON LOW LEVEL THICKNESS VALUES AREA EXPECTED TO CLIMB INTO 1415-1430 METER RANGE... HIGHEST WEDNESDAY IN ADVANCE OF ANOTHER FRONT. THIS WILL YIELD A CONTINUED WARMING TREND... WITH HIGHS AT LEAST IN THE UPPER 80S TO LOWER 90S ON TUESDAY... WITH HIGHS A FEW DEGREES WARMER ON WEDNESDAY (WITH POSSIBLY SOME MID 90S SOUTH). LOWS ARE EXPECTED TO BE IN THE MID TO UPPER 60S... WITH SOME LOWER 70S SOUTH/SOUTHEAST. THURSDAY THROUGH SATURDAY: A NORTHERN STREAM TROUGH IS EXPECTED TO AMPLIFY THE MID LEVEL TROUGH ACROSS THE EASTERN U.S. AND SEND ANOTHER COLD FRONT INTO AND POSSIBLY ACROSS CENTRAL NC ON THURSDAY. THIS SHOULD LEAD TO A BETTER CHANCE OF SHOWERS AND STORMS ON THURSDAY. HOWEVER... THIS WILL DEPEND ON THE ACTUAL TIMING OF THE FRONT. FOR NOW WILL TREND CLOSER TO WPC... WHICH IS SIMILAR TO THE LATEST ECMWF ALLOWING THE FRONT TO BECOME MORE ACTIVE AS IT MOVES INTO THE AREA DURING PEAK HEATING ON THURSDAY. THE SURFACE FRONT IS EXPECTED TO STALL NEAR THE NC/SC BORDER... LEADING TO CONTINUED CHANCES OF SHOWERS AND STORMS... ESPECIALLY ACROSS THE SOUTHERN HALF OF THE AREA. EXPECT HIGHS WILL BE COOLER BEHIND THE FRONT. FOR NOW WILL STICK CLOSE TO WPC... HIGHS IN THE 80S... LOWS IN THE 60S. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... AS OF 200 PM SUNDAY... 24 HOUR TAF PERIOD: SOME SIGNS OF IMPROVING CONDITIONS OUT THERE THIS AFTERNOON WITH MOST SIGHTS COMING IN WITH MVFR CEILINGS BUT THE TRIAD IS STARTING TO SCATTER OUT A BIT AND THAT TREND SHOULD CONTINUE THROUGH THE AFTERNOON. THEREFORE EXPECTING MOSTLY VFR CONDITIONS IN THE TRIAD WITH MVFR CONDITIONS TO THE EAST BUT EVEN THE EAST WILL HAVE A CHANCE TO BREAK OUT AS THE AFTERNOON GOES ON...IF ONLY BRIEFLY. WITH A MOIST AIRMASS STILL IN PLACE AND SOME POTENTIAL CLEARING...DENSE FOG IS A POSSIBILITY AGAIN OVERNIGHT...ESPECIALLY IN THE TRIAD WITH AREAS OF FOG ELSEWHERE AND LIFR CEILINGS AGAIN POSSIBLE OVER MUCH OF THE AREA. THIS WILL OCCUR AFTER 6Z IN THE EAST AND MAY HOLD OFF TO NEAR 9Z IN THE WEST. WINDS WILL BE LIGHT AND VARIABLE THROUGH THE TAF PERIOD AND FOR THE MOST PART PRECIPIATION SHOULD STAY EAST OF THE FORECAST AREA...SO HAVE TAKEN IT OUT OF THE TAFS AT THIS TIME BUT IT WILL BE A POSSIBILITY AGAIN TOMORROW ESPECIALLY IN THE EAST. LONG TERM: A LOW WILL TRACK OFF THE COAST ON MONDAY BUT THE UPPER LEVEL TROUGH WILL BEGIN TO FINALLY LIFT OUT...LEADING TO A GENERAL IMPROVEMENT IN CONDITIONS THROUGH THE FIRST HALF OF THE WEEK BEFORE A SYSTEM MOVES IN FROM THE NORTHWEST FOR THE END OF THE WEEK. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...WSS NEAR TERM...ELLIS SHORT TERM...WSS LONG TERM...BSD AVIATION...ELLIS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
132 PM EDT SUN AUG 3 2014 .SYNOPSIS...A SLOW MOVING UPPER LEVEL TROUGH OVER THE TENNESSEE VALLEY COUPLED WITH A STATIONARY SURFACE BOUNDARY STRETCHING SOUTH TO NORTH OVER COASTAL CAROLINAS WILL MAINTAIN A MOIST AND UNSETTLED WEATHER PATTERN OVER MOST OF CENTRAL NC THROUGH MONDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1015 AM SUNDAY... UPPER LEVEL TROUGH REMAINS WEST OF THE AREA WITH UPPER LEVEL LOW PRESSURE CENTERED OVER THE OHIO VALLEY. UPPER AIR ANALYSIS FROM 12Z SHOWS SHEAR AXIS ASSOCIATED WITH SHORTWAVE EXTENDING DOWN THROUGH TENNESSEE. THIS WAVE WILL MOVE INTO THE NW PIEDMONT LATER TODAY AND HOPEFULLY WILL ACT AS AN ERODING MECHANISM TO BEGIN BREAKING UP THE CAD WEDGE...AT LEAST THE TRIAD. TIMING OF THIS FEATURE WILL BE TOUGH BUT THE RAP HAS IT MAKING HEADWAY INTO THE TRIAD BY EARLY AFTERNOON WITH A SUBSEQUENT DROP IN DEWPOINTS AND RELATIVE HUMIDITY. THEREFORE EXPECTING A SIMILAR DEPICTION OF THE PRECIP TO WHAT THE RADAR IS SHOWING NOW WHICH IS A VERY DEFINITIVE LINE OF PRECIP IN THE COASTAL PLAIN WITH MUCH DRIER CONDITIONS WEST OF I-95. THAT BEING SAID...THE TRIANGLE AREA WILL PROBABLY STAY CLOUDY FOR MUCH OF THE DAY WITH ONLY THE NW PIEDMONT HAVING A REAL CHANCE OF BREAKING OUT THIS AFTERNOON. THIS WILL MAKE TEMPERATURES TRICKY WITH AN ABNORMAL DISTRIBUTION OF WARMEST TEMPERATURES IN THE NW AND COOLEST IN THE SOUTHEAST. IF THE CAD BREAKS DOWN...COULD EASILY SEE LOWER 80S IN THE TRIAD WITH POSSIBLY ONLY MID 70S IN THE SOUTHEAST. THE GREATEST THREAT FOR PRECIPITATION WILL BE IN THE EXTREME SOUTHEAST TODAY WITH SAMPSON COUNTY BEING MONITORED AT THIS TIME FOR POTENTIAL URBAN AND SMALL STREAM FLOODING. KLTX RADAR INDICATES BETWEEN 2 AND 3 INCHES OF RAIN FALLEN IN THIS LOCATION ALREADY WITH SOME FURTHER TRAINING OF MODERATE TO HEAVY RAIN POSSIBLE OVER THE NEXT FEW HOURS. THE FLOOD WATCH REMAINS IN EFFECT THROUGH 00Z MONDAY FOR THE EASTERN TIER OF COUNTIES. NOT EXPECTING MUCH IN THE WAY OF SEVERE WEATHER THIS AFTERNOON ALTHOUGH THERE WILL BE SOME DECENT INSTABILITY IN THE EAST...SHEAR VALUES HAVE DROPPED OFF SIGNIFICANTLY BUT ARE STILL AT A MODEST 25 KTS. AS IN PREVIOUS DAYS...THE EXTENSIVE OVERCAST AND LACK OF INSOLATION SHOULD INHIBIT MOST THUNDERSTORM ACTIVITY THIS AFTERNOON. IF SOME CLEARING DOES OCCUR IN THE TRIAD...CAN EXPECT ANOTHER ROUND OF POTENTIALLY DENSE FOG OVERNIGHT. ELSEWHERE A PERSISTENCE FORECAST OF LIFR/IFR CEILINGS WILL PROBABLY WORK OUT WELL. THERE SHOULD BE A LULL IN PRECIPIATION AS PRECIPITATION BEGINS TO PUSH EASTWARD OFFSHORE. LOW TEMPERATURES TONIGHT MID 60S NW TO NEAR 70 SE. && .SHORT TERM /MONDAY AND MONDAY NIGHT/... AS OF 420 AM SUNDAY... STILL A DECENT THREAT FOR ADDITIONAL SHOWERS AND STORMS OVER OUR EASTERN PERIPHERY AS MID-UPPER LEVEL SHEAR AXIS WITHIN THE MOISTURE PLUME ONLY DRIFTS SLOWLY EWD. PLAN TO HAVE LIKELY POPS OVER THE COASTAL PLAIN AND SANDHILLS...TAPERING TO A SMALL CHANCE IN THE WESTERN PIEDMONT. AFTER MORNING LOW CLOUDS AND FOG BURN-OFF...EXPECT PARTIAL SUNSHINE ACROSS THE PIEDMONT. THIS SHOULD WARM TEMPS INTO THE LOW-MID 80S. A SURFACE WAVE LIFTING NEWD JUST OFFSHORE WILL MAINTAIN A THREAT FOR SHOWERS ACROSS THE COASTAL PLAIN THROUGH THE OVERNIGHT HOURS. AGAIN...SHOULD SEE AREAS OF LOW CLOUDS AND/OR FOG DEVELOP. MIN TEMPS MID 60S TO AROUND 70. && .LONG TERM /TUESDAY THROUGH SATURDAY/... AS OF 320 AM SUNDAY... TUESDAY THROUGH WEDNESDAY NIGHT: HIGHER PW`S ARE EXPECTED TO PUSH TO THE EAST OF THE AREA DURING THE PERIOD AS WE CONTINUE TO TRANSITION TO MORE OF A TYPICAL SUMMERTIME PATTERN. MID LEVEL TROUGHING ACROSS THE EASTERN U.S. WILL REMAIN THOUGH... WITH A LEE SIDE TROUGH DEVELOPING/BECOMES MORE ESTABLISHED OVER THE AREA. THIS WILL LEAD TO MORE OF A SLIGHT CHANCE/LOW END CHANCE OF SHOWERS AND STORMS FOR TUESDAY... WITH EVEN A LESSER CHANCE ON WEDNESDAY (BEST CHANCE ACROSS THE EAST). GIVEN THE DRIER MID LEVEL AIR EXPECTED TO MOVE INTO THE AREA DURING THIS TIME... EXPECT WE SHOULD SEE MORE INCOMING SOLAR RADIATION... RESULTING IN WARMING TEMPS BOTH DAYS AS AFTERNOON LOW LEVEL THICKNESS VALUES AREA EXPECTED TO CLIMB INTO 1415-1430 METER RANGE... HIGHEST WEDNESDAY IN ADVANCE OF ANOTHER FRONT. THIS WILL YIELD A CONTINUED WARMING TREND... WITH HIGHS AT LEAST IN THE UPPER 80S TO LOWER 90S ON TUESDAY... WITH HIGHS A FEW DEGREES WARMER ON WEDNESDAY (WITH POSSIBLY SOME MID 90S SOUTH). LOWS ARE EXPECTED TO BE IN THE MID TO UPPER 60S... WITH SOME LOWER 70S SOUTH/SOUTHEAST. THURSDAY THROUGH SATURDAY: A NORTHERN STREAM TROUGH IS EXPECTED TO AMPLIFY THE MID LEVEL TROUGH ACROSS THE EASTERN U.S. AND SEND ANOTHER COLD FRONT INTO AND POSSIBLY ACROSS CENTRAL NC ON THURSDAY. THIS SHOULD LEAD TO A BETTER CHANCE OF SHOWERS AND STORMS ON THURSDAY. HOWEVER... THIS WILL DEPEND ON THE ACTUAL TIMING OF THE FRONT. FOR NOW WILL TREND CLOSER TO WPC... WHICH IS SIMILAR TO THE LATEST ECMWF ALLOWING THE FRONT TO BECOME MORE ACTIVE AS IT MOVES INTO THE AREA DURING PEAK HEATING ON THURSDAY. THE SURFACE FRONT IS EXPECTED TO STALL NEAR THE NC/SC BORDER... LEADING TO CONTINUED CHANCES OF SHOWERS AND STORMS... ESPECIALLY ACROSS THE SOUTHERN HALF OF THE AREA. EXPECT HIGHS WILL BE COOLER BEHIND THE FRONT. FOR NOW WILL STICK CLOSE TO WPC... HIGHS IN THE 80S... LOWS IN THE 60S. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... AS OF 740 AM SUNDAY... ADVERSE AVIATION WEATHER CONDITIONS WILL PERSIST ACROSS MUCH OF CENTRAL NC THROUGH MONDAY AS THE LOW LEVEL AIR MASS WILL REMAIN VERY MOIST AND A SERIES OF UPPER LEVEL DISTURBANCES TRIGGER SCATTERED SHOWERS AND STORMS. THE GREATEST RISK FOR SHOWERS AND POSSIBLY A THUNDERSTORM WILL BE IN VICINITY OF KFAY AND KRWI. THE RISK FOR SHOWERS WILL DIMINISH APPRECIABLY AS YOU GO FARTHER WEST INTO THE PIEDMONT AND FOOTHILLS. WIDESPREAD IFR/LIFR CEILINGS WILL PERSIST OVERNIGHT INTO THE FIRST HALF OF THIS MORNING WITH AREAS OF DENSE FOG...MAINLY ACROSS THE WESTERN AND SOUTHERN PIEDMONT. A SLOW IMPROVEMENT IN AVIATION CONDITIONS SHOULD OCCUR LATER TODAY IN THE WESTERN PIEDMONT AS DRIER AIR ALOFT MIXES TOWARD THE SURFACE...AIDING TO DIMINISH LOW LEVEL CLOUDINESS. THERE IS A GOOD CHANCE THAT VFR CONDITIONS WILL RETURN TO KINT AND KGSO BY EARLY AFTERNOON. ELSEWHERE...SUB VFR CONDITIONS WILL PERSIST. ANOTHER ROUND OF MVFR/IFR CEILINGS AND IFR/LIFR FOG APPEARS LIKELY TONIGHT INTO EARLY MONDAY. EXPECT TO SEE CONDITIONS IMPROVE TO VFR AT KRDU...KGSO AND KINT BY LATE MORNING-EARLY AFTERNOON MONDAY WHILE MOSTLY MVFR CONDITIONS LINGER AT KFAY AND KRWI WHERE A RISK OF SHOWERS AND POSSIBLY A THUNDERSTORM WILL REMAIN. A SLOW IMPROVEMENT IN AVIATION CONDITIONS ANTICIPATED TUESDAY THROUGH THURSDAY. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...WSS NEAR TERM...ELLIS SHORT TERM...WSS LONG TERM...BSD AVIATION...WSS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1021 AM EDT SUN AUG 3 2014 .SYNOPSIS...A SLOW MOVING UPPER LEVEL TROUGH OVER THE TENNESSEE VALLEY COUPLED WITH A STATIONARY SURFACE BOUNDARY STRETCHING SOUTH TO NORTH OVER COASTAL CAROLINAS WILL MAINTAIN A MOIST AND UNSETTLED WEATHER PATTERN OVER MOST OF CENTRAL NC THROUGH MONDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1015 AM SUNDAY... UPPER LEVEL TROUGH REMAINS WEST OF THE AREA WITH UPPER LEVEL LOW PRESSURE CENTERED OVER THE OHIO VALLEY. UPPER AIR ANALYSIS FROM 12Z SHOWS SHEAR AXIS ASSOCIATED WITH SHORTWAVE EXTENDING DOWN THROUGH TENNESSEE. THIS WAVE WILL MOVE INTO THE NW PIEDMONT LATER TODAY AND HOPEFULLY WILL ACT AS AN ERODING MECHANISM TO BEGIN BREAKING UP THE CAD WEDGE...AT LEAST THE TRIAD. TIMING OF THIS FEATURE WILL BE TOUGH BUT THE RAP HAS IT MAKING HEADWAY INTO THE TRIAD BY EARLY AFTERNOON WITH A SUBSEQUENT DROP IN DEWPOINTS AND RELATIVE HUMIDITY. THEREFORE EXPECTING A SIMILAR DEPICTION OF THE PRECIP TO WHAT THE RADAR IS SHOWING NOW WHICH IS A VERY DEFINITIVE LINE OF PRECIP IN THE COASTAL PLAIN WITH MUCH DRIER CONDITIONS WEST OF I-95. THAT BEING SAID...THE TRIANGLE AREA WILL PROBABLY STAY CLOUDY FOR MUCH OF THE DAY WITH ONLY THE NW PIEDMONT HAVING A REAL CHANCE OF BREAKING OUT THIS AFTERNOON. THIS WILL MAKE TEMPERATURES TRICKY WITH AN ABNORMAL DISTRIBUTION OF WARMEST TEMPERATURES IN THE NW AND COOLEST IN THE SOUTHEAST. IF THE CAD BREAKS DOWN...COULD EASILY SEE LOWER 80S IN THE TRIAD WITH POSSIBLY ONLY MID 70S IN THE SOUTHEAST. THE GREATEST THREAT FOR PRECIPITATION WILL BE IN THE EXTREME SOUTHEAST TODAY WITH SAMPSON COUNTY BEING MONITORED AT THIS TIME FOR POTENTIAL URBAN AND SMALL STREAM FLOODING. KLTX RADAR INDICATES BETWEEN 2 AND 3 INCHES OF RAIN FALLEN IN THIS LOCATION ALREADY WITH SOME FURTHER TRAINING OF MODERATE TO HEAVY RAIN POSSIBLE OVER THE NEXT FEW HOURS. THE FLOOD WATCH REMAINS IN EFFECT THROUGH 00Z MONDAY FOR THE EASTERN TIER OF COUNTIES. NOT EXPECTING MUCH IN THE WAY OF SEVERE WEATHER THIS AFTERNOON ALTHOUGH THERE WILL BE SOME DECENT INSTABILITY IN THE EAST...SHEAR VALUES HAVE DROPPED OFF SIGNIFICANTLY BUT ARE STILL AT A MODEST 25 KTS. AS IN PREVIOUS DAYS...THE EXTENSIVE OVERCAST AND LACK OF INSOLATION SHOULD INHIBIT MOST THUNDERSTORM ACTIVITY THIS AFTERNOON. IF SOME CLEARING DOES OCCUR IN THE TRIAD...CAN EXPECT ANOTHER ROUND OF POTENTIALLY DENSE FOG OVERNIGHT. ELSEWHERE A PERSISTENCE FORECAST OF LIFR/IFR CEILINGS WILL PROBABLY WORK OUT WELL. THERE SHOULD BE A LULL IN PRECIPIATION AS PRECIPITATION BEGINS TO PUSH EASTWARD OFFSHORE. LOW TEMPERATURES TONIGHT MID 60S NW TO NEAR 70 SE. && .SHORT TERM /MONDAY AND MONDAY NIGHT/... AS OF 420 AM SUNDAY... STILL A DECENT THREAT FOR ADDITIONAL SHOWERS AND STORMS OVER OUR EASTERN PERIPHERY AS MID-UPPER LEVEL SHEAR AXIS WITHIN THE MOISTURE PLUME ONLY DRIFTS SLOWLY EWD. PLAN TO HAVE LIKELY POPS OVER THE COASTAL PLAIN AND SANDHILLS...TAPERING TO A SMALL CHANCE IN THE WESTERN PIEDMONT. AFTER MORNING LOW CLOUDS AND FOG BURN-OFF...EXPECT PARTIAL SUNSHINE ACROSS THE PIEDMONT. THIS SHOULD WARM TEMPS INTO THE LOW-MID 80S. A SURFACE WAVE LIFTING NEWD JUST OFFSHORE WILL MAINTAIN A THREAT FOR SHOWERS ACROSS THE COASTAL PLAIN THROUGH THE OVERNIGHT HOURS. AGAIN...SHOULD SEE AREAS OF LOW CLOUDS AND/OR FOG DEVELOP. MIN TEMPS MID 60S TO AROUND 70. && .LONG TERM /TUESDAY THROUGH SATURDAY/... AS OF 320 AM SUNDAY... TUESDAY THROUGH WEDNESDAY NIGHT: HIGHER PW`S ARE EXPECTED TO PUSH TO THE EAST OF THE AREA DURING THE PERIOD AS WE CONTINUE TO TRANSITION TO MORE OF A TYPICAL SUMMERTIME PATTERN. MID LEVEL TROUGHING ACROSS THE EASTERN U.S. WILL REMAIN THOUGH... WITH A LEE SIDE TROUGH DEVELOPING/BECOMES MORE ESTABLISHED OVER THE AREA. THIS WILL LEAD TO MORE OF A SLIGHT CHANCE/LOW END CHANCE OF SHOWERS AND STORMS FOR TUESDAY... WITH EVEN A LESSER CHANCE ON WEDNESDAY (BEST CHANCE ACROSS THE EAST). GIVEN THE DRIER MID LEVEL AIR EXPECTED TO MOVE INTO THE AREA DURING THIS TIME... EXPECT WE SHOULD SEE MORE INCOMING SOLAR RADIATION... RESULTING IN WARMING TEMPS BOTH DAYS AS AFTERNOON LOW LEVEL THICKNESS VALUES AREA EXPECTED TO CLIMB INTO 1415-1430 METER RANGE... HIGHEST WEDNESDAY IN ADVANCE OF ANOTHER FRONT. THIS WILL YIELD A CONTINUED WARMING TREND... WITH HIGHS AT LEAST IN THE UPPER 80S TO LOWER 90S ON TUESDAY... WITH HIGHS A FEW DEGREES WARMER ON WEDNESDAY (WITH POSSIBLY SOME MID 90S SOUTH). LOWS ARE EXPECTED TO BE IN THE MID TO UPPER 60S... WITH SOME LOWER 70S SOUTH/SOUTHEAST. THURSDAY THROUGH SATURDAY: A NORTHERN STREAM TROUGH IS EXPECTED TO AMPLIFY THE MID LEVEL TROUGH ACROSS THE EASTERN U.S. AND SEND ANOTHER COLD FRONT INTO AND POSSIBLY ACROSS CENTRAL NC ON THURSDAY. THIS SHOULD LEAD TO A BETTER CHANCE OF SHOWERS AND STORMS ON THURSDAY. HOWEVER... THIS WILL DEPEND ON THE ACTUAL TIMING OF THE FRONT. FOR NOW WILL TREND CLOSER TO WPC... WHICH IS SIMILAR TO THE LATEST ECMWF ALLOWING THE FRONT TO BECOME MORE ACTIVE AS IT MOVES INTO THE AREA DURING PEAK HEATING ON THURSDAY. THE SURFACE FRONT IS EXPECTED TO STALL NEAR THE NC/SC BORDER... LEADING TO CONTINUED CHANCES OF SHOWERS AND STORMS... ESPECIALLY ACROSS THE SOUTHERN HALF OF THE AREA. EXPECT HIGHS WILL BE COOLER BEHIND THE FRONT. FOR NOW WILL STICK CLOSE TO WPC... HIGHS IN THE 80S... LOWS IN THE 60S. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... AS OF 740 AM SUNDAY... ADVERSE AVIATION WEATHER CONDITIONS WILL PERSIST ACROSS MUCH OF CENTRAL NC THROUGH MONDAY AS THE LOW LEVEL AIR MASS WILL REMAIN VERY MOIST AND A SERIES OF UPPER LEVEL DISTURBANCES TRIGGER SCATTERED SHOWERS AND STORMS. THE GREATEST RISK FOR SHOWERS AND POSSIBLY A THUNDERSTORM WILL BE IN VICINITY OF KFAY AND KRWI. THE RISK FOR SHOWERS WILL DIMINISH APPRECIABLY AS YOU GO FARTHER WEST INTO THE PIEDMONT AND FOOTHILLS. WIDESPREAD IFR/LIFR CEILINGS WILL PERSIST OVERNIGHT INTO THE FIRST HALF OF THIS MORNING WITH AREAS OF DENSE FOG...MAINLY ACROSS THE WESTERN AND SOUTHERN PIEDMONT. A SLOW IMPROVEMENT IN AVIATION CONDITIONS SHOULD OCCUR LATER TODAY IN THE WESTERN PIEDMONT AS DRIER AIR ALOFT MIXES TOWARD THE SURFACE...AIDING TO DIMINISH LOW LEVEL CLOUDINESS. THERE IS A GOOD CHANCE THAT VFR CONDITIONS WILL RETURN TO KINT AND KGSO BY EARLY AFTERNOON. ELSEWHERE...SUB VFR CONDITIONS WILL PERSIST. ANOTHER ROUND OF MVFR/IFR CEILINGS AND IFR/LIFR FOG APPEARS LIKELY TONIGHT INTO EARLY MONDAY. EXPECT TO SEE CONDITIONS IMPROVE TO VFR AT KRDU...KGSO AND KINT BY LATE MORNING-EARLY AFTERNOON MONDAY WHILE MOSTLY MVFR CONDITIONS LINGER AT KFAY AND KRWI WHERE A RISK OF SHOWERS AND POSSIBLY A THUNDERSTORM WILL REMAIN. A SLOW IMPROVEMENT IN AVIATION CONDITIONS ANTICIPATED TUESDAY THROUGH THURSDAY. && .RAH WATCHES/WARNINGS/ADVISORIES... FLOOD WATCH THROUGH THIS EVENING FOR NCZ028-043-078-088-089. && $$ SYNOPSIS...WSS NEAR TERM...ELLIS SHORT TERM...WSS LONG TERM...BSD AVIATION...WSS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1015 AM EDT SUN AUG 3 2014 .SYNOPSIS... A COASTAL FRONT WILL KEEP THE WEATHER UNSETTLED TODAY. RAIN CHANCES CONTINUE OR POSSIBLY INCREASE ON MONDAY AS A TROPICAL WAVE MOVES NORTHWARD BY THE AREA. BERTHA WILL REMAIN MUCH TOO FAR OFFSHORE FOR ANY DIRECT IMPACTS THROUGH TUESDAY. MORE SEASONABLE WEATHER RETURNS WEDNESDAY AND THURSDAY. COOLER WEATHER IS THEN SLATED FOR THE LATE WEEK PERIOD BEHIND A COLD FRONT. && .NEAR TERM /THROUGH TONIGHT/... AS OF 10 AM SUNDAY...A HEAVY BAND OF SHOWERS AND THUNDERSTORMS HAS DEVELOPED INLAND THIS MORNING. ENHANCED ISENTROPIC LIFT IN AN AREA OF 850-500MB LAYER RH GREATER THAN 95% IS PARTLY RESPONSIBLE BUT SO IS AN AREA OF 850 MB FRONTOGENESIS. ALL OF THIS IS BEING AIDED BY DIVERGENCE ALOFT. SOME OF THESE AREAS HAVE BEEN SHOWING 2 TO 2.5 INCH PER HOUR RAINFALL RATES. GFS HAS THE LOCATION OF THESE FEATURES FAIRLY CLOSE TO REALITY AND SHOWS THE ISENTROPIC LIFT AND FRONTOGENESIS SHIFTING OF TO THE NORTH-NORTHEAST AROUND MIDDAY. FOR THE REMAINDER OF THE AREA THE SETUP REMAINS RELATIVELY UNCHANGED. THE TROUGH HAS SHIFTED BACK TO THE COAST...AS IT DID YESTERDAY MORNING. TROUGH WILL ONCE AGAIN TRY TO MOVE INLAND TODAY AND THINK IT WILL HAVE A LITTLE MORE SUCCESS THIS AFTERNOON AS THE HIGH WEDGING DOWN THE COAST IS NOT QUITE AS STRONG AS IT WAS YESTERDAY. DEEP MOISTURE REMAINS IN PLACE...WITH PRECIPITABLE WATER VALUES REMAINING ABOVE 2 INCHES...ALONG WITH SOME WEAK INSTABILITY. STORM MOTION IS SLOWER THAN THE PAST FEW DAYS...AROUND 7 KT...AND WARM LAYER REMAINS QUITE DEEP AROUND 15K FT. FLOODING WILL REMAIN A CONCERN WITH ANY STORMS THAT DO DEVELOP...ESPECIALLY GIVEN THE AMOUNT OF RAINFALL IN MANY AREAS OVER THE LAST FEW DAYS. TEMPERATURES THIS AFTERNOON WILL REMAIN WELL BELOW CLIMO WITH HIGHS RUNNING IN THE UPPER 70S TO LOWER 80S. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 3 AM SUNDAY...MONDAYS FORECAST WILL NOW HINGE UPON WHAT MAY END UP BEING A COMPLEX (AND POORLY SAMPLED) INTERACTION BETWEEN TWO CIRCULATIONS OFF THE EAST COAST...BERTHA AND TROPICAL WAVE NOW IN THE BAHAMAS. WRF SCORED A BIT OF A COUP WHEN IT STARTED SHOWING THIS LAST NIGHT. THE QUESTION THAT NOW REMAINS TO BE SEEN...WHICH CIRCULATION BECOMES THE DOMINANT ONE? WRF MAINTAINS THAT IT WILL BE THE WESTERN SYSTEM AND THAT THE COAST IS IN FOR QUITE A RAINSTORM FOLLOWING A WET WEEKEND AND OUR CURRENT FLOOD WATCH WILL LIKELY NEED TO BE EXTENDED. BERTHA CURRENTLY UNDERGOING LAND INTERACTION WITH HISPANIOLA...AND SEEMINGLY MAINTAINING A FAIR AMOUNT OF CONVECTION...AND SO RIGHT NOW IT SEEMS THAT THE WRF IS A BIT EXTREME. GFS LAST NIGHT PRETTY MUCH IGNORED THE BAHAMA LOW BUT NOW GIVES IT AN IDENTITY THROUGH THE PERIOD WHILE SEEMINGLY PLAUSIBLY KEEPING BERTHA AS A SEPARATE ENTITY. THE MAIN PROBLEM WITH THE GFS IS IT SEEMS ERRONEOUSLY SLOW WITH THE WESTERN LOW AND SHOWS SURPRISINGLY LITTLE QPF FOR A SYSTEM THAT IS NOT ONLY OF TROPICAL ORIGIN BUT ALSO POSSIBLY TAPPING SOME MOISTURE FROM A TROPICAL STORM. THIS SYSTEM WILL LIKELY STILL BE PUSHING MOISTURE TOWARDS THE COAST MONDAY NIGHT INTO TUESDAY MORNING. TUESDAY AFTERNOON WILL BRING A DRYING TREND AT LEAST IN THE MID LEVELS. RAIN CHANCES WILL BE ON THE DECLINE AND THE AREA MAY START TO SEE SOME MORE BREAKS OF SUN THAN IT HAS RECENTLY. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS OF 3 PM SUNDAY...WEDNESDAY WILL OFFER UP SEASONABLY WARM WEATHER AND MINIMAL RAIN CHANCES. NEARLY ZONAL/WESTERLY MID LEVEL FLOW LOCALLY AROUND PERSISTENT TROUGHINESS IN THE NORTHEAST TO KEEP THINGS FAIRLY DRY. VERY LOW RAIN CHANCES COMING FROM SEA BREEZE AND PIEDMONT TROUGH WHERE AN ISOLATED SHOWER OR TSTM CANNOT BE RULED OUT. AFOREMENTIONED UPPER TROUGH SHARPENS ON THURSDAY DRIVING A LATE DAY COLD FRONT INTO THE REGION. WITH THE LACK OF MID LEVEL MOISTURE AND EVEN NO APPRECIABLE INFLUX OF GULF OR ATLANTIC LOW LEVEL MOISTURE AHEAD OF THE BOUNDARY ITS HARD TO IMAGINE HOW IT BRINGS AN APPRECIABLE INCREASE IN RAIN CHANCES. AS IT STALLS TO OUR SOUTH IT WILL USHER IN SOME COOLER AIR OVER THE WEEKEND. TOUGH TO SAY HOW MUCH PENDING HOW CLOUDY IT GETS VS THE ACTUAL AIRMASS CHANGE/COOL ADVECTION. && .AVIATION /14Z SUNDAY THROUGH THURSDAY/... AS OF 12Z...STALLED FRONT/TROUGH WILL CONTINUE OVER THE REGION WITH CONVECTION FIRING ALONG THE COAST ALL MORNING. INLAND TERMINALS WILL REMAIN IFR AT LEAST THROUGH 15Z...PERHAPS INTO THE AFTERNOON. PREDOMINATELY MVFR ALONG THE COAST WITH OCCASIONAL THUNDER POSSIBLE WITH BRIEF HEAVY RAIN. THE HRRR MODEL INDICATES PRECIP MAY MOVE INLAND FROM THE COAST BY NOON...BUT CONFIDENCE IS RATHER LOW. TONIGHT...SHOWERS WILL RETURN DUE TO AN INVERTED TROUGH FROM LOW PRESSURE MOVING UP FROM THE SOUTH. EXTENDED OUTLOOK...SHRA/TSRA LIKELY WITH PERIODS OF MVFR CONDITIONS THROUGH TUESDAY AS A FRONT STALLS AND FINALLY DISSIPATES OVER THE EASTERN CAROLINAS. A CHANCE OF SHOWERS CONTINUES ON WEDNESDAY LATE INTO THURSDAY MORNING. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 10 AM SUNDAY...SOUTHEAST FLOW 10 TO 15 KT WILL CONTINUE THROUGH THE PERIOD. TROUGH STALLED ALONG THE COAST THIS MORNING WILL SLOWLY PUSH INLAND TODAY. CONVECTION IS LIKELY TO CONTINUE OVER THE WATERS BUT WITH COVERAGE DECREASING. SEAS WILL RUN 3 FT...MAINLY AS SOUTHEAST WIND WAVE...THOUGH 4 FT IS POSSIBLE IN AND AROUND CONVECTION. SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 3 AM SUNDAY...PRETTY DIFFICULT FORECAST ON MONDAY. WINDS WILL BE MAINLY A FUNCTION OF THE INTERACTION BETWEEN BERTHA AND A TROPICAL WAVE NOW OVER THE BAHAMAS. MODEL SOLUTIONS VARY CONSIDERABLY AS TO HOW THESE TWO WILL INTERACT AND WHICH ONE WILL END UP BECOMING A DOMINANT CIRCULATION AS THEY BOTH PASS NORTHWARD ACROSS OUR LATITUDE ON MONDAY. BERTHA CURRENTLY INTERACTING WITH HISPANIOLA FURTHER COMPLICATING THE ISSUE. SOUTHEASTERLY WINDS SHOULD BE PREDOMINANT LOCALLY EITHER WAY...ALTHOUGH THE STRENGTH OF THESE WINDS AND TO A LESSER EXTENT THE MAGNITUDE OF SEAS REALIZED WILL BE MODULATED BY WHICH SYSTEM TAKES OVER. SHOULD IT BE BERTHA THEN THE CURRENT FCST APPLIES. SHOULD THE WESTWARD WAVE TAKE OVER THEN WINDS MAY BE A BIT HIGHER IN SPEED AND CHANGE MORE THROUGH THE DAY AS THE FCST ZONES EXPERIENCE MORE CLOSED ISOBARS. A SMALL CRAFT ADVISORY IS GETTING TOUGH TO RULE OUT ESP FOR NRN ZONES BUT THERE IS JUST TOO MUCH UNCERTAINTY TO RAISE AT THIS POINT. EITHER WAY WINDS SHOULD SWING AROUND TO THE NORTH AND THEN WEST ON TUESDAY AS THE SYSTEMS ACCELERATE OFF TO THE NORTH AND EAST. SUCH A TURN TO OFFSHORE OFTEN ACTS TO DIMINISH NEARSHORE SEAS AS LANDMASS WAVE SHADOWING TAKES OVER BUT THERE WILL BE ENOUGH BACKSWELL TO MINIMIZE THIS FOR MUCH OF TUESDAY. THE EXCEPTION SHOULD BE BRUNSWICK WATERS WHERE THERE WILL NOT ONLY BE WESTERLY SHADOWING OF WIND WAVES BUT ALSO A SWELL SHADOWING FROM CAPE FEAR. LONG TERM /WEDNESDAY THROUGH THURSDAY/... AS OF 3 PM SUNDAY...WEAK PIEDMONT TROUGHINESS TAKES SHAPE ON WEDNESDAY YIELDING A SOUTHWESTERLY WIND OF FAIRLY `SEASONABLE` SPEED. SEAS NORMALLY 2 TO 3 FT IN SUCH A SETUP BUT A REMNANT EASTERLY SWELL MAY STILL BE GIVING RISE TO 4 FT DOMINANT WAVES OVER NRN ZONES. THE TROUGH MOVES CLOSER TO THE COAST ON THURSDAY WHILE A COLD FRONT ALSO APPROACHES FROM THE NW. OVERALL THE GRADIENT WILL EASE AND THE FLOW MAY BACK TO SRLY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR SCZ017-023-024-032- 033-039-053>056. NC...FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR NCZ087-096-099- 105>110. MARINE...NONE. && $$ SYNOPSIS...MBB NEAR TERM...III SHORT TERM...MBB LONG TERM...MBB AVIATION...43
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
642 AM EDT SUN AUG 3 2014 .SYNOPSIS... A COASTAL FRONT WILL KEEP THE WEATHER UNSETTLED TODAY. RAIN CHANCES CONTINUE OR POSSIBLY INCREASE ON MONDAY AS A TROPICAL WAVE MOVES NORTHWARD BY THE AREA. BERTHA WILL REMAIN MUCH TOO FAR OFFSHORE FOR ANY DIRECT IMPACTS THROUGH TUESDAY. MORE SEASONABLE WEATHER RETURNS WEDNESDAY AND THURSDAY. COOLER WEATHER IS THEN SLATED FOR THE LATE WEEK PERIOD BEHIND A COLD FRONT. && .NEAR TERM /THROUGH TONIGHT/... AS OF 6:30 AM SUNDAY...NO CHANGES TO THE FORECAST WITH THE LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS: LATEST WRINKLE IN THE NEAR TERM FORECAST CONCERNS FORMATION OF A TROPICAL DISTURBANCE OVER THE BAHAMAS. SYSTEM IS MOVING NORTH AT AROUND 10 MPH. ALTHOUGH THE NHC SAYS DISTURBANCE IS SHOWING NO SIGNS OF ORGANIZATION AND ONLY GIVES IT A 10 PERCENT CHANCE OF FORMATION OUT THROUGH 5 DAYS...NAM AND TO A LESSER EXTEND THE GFS HINT AT AN INTERACTION BETWEEN THIS FEATURE AND AN INVERTED TROUGH/TROPICAL WAVE FEATURE JUST OFFSHORE THAT COULD MARKEDLY INCREASE PRECIPITATION CHANCES OVERNIGHT. THE ECMWF IS ALSO IN THIS CAMP WITH THEIR LATEST AVAILABLE GUIDANCE. IF THIS SCENARIO COME TO PASS...WE WILL HAVE TO CONSIDER EXTENDING THE PRESENT FLOOD WATCH THROUGH TONIGHT. IN ANY CASE...CONDITIONS REMAIN FAVORABLE FOR PERIODS OF HEAVY RAIN AT LEAST THROUGH THE DAYLIGHT HOURS..SO WILL BE KEEPING THE RESENT FLOOD WATCH UP INTO THE NEAR TERM. A PERSISTENT AND NEARLY STATIONARY FRONT IS ANALYZED OVER OUR NC AND SC COASTAL PLAIN COUNTIES THIS MORNING. MODEL CONSENSUS HAS THIS FRONT WAVERING BACK AND FORTH THROUGH THE PERIOD...ALTHOUGH TIMING OF FRONT PLACEMENT IS LOW CONFIDENCE DUE TO MODEL SPREAD IN ITS MOTION. AT THE UPPER LEVELS A LONG-WAVE TROUGH WILL MAINTAIN ITS HOLD OVER EASTERN CONUS AS A SERIES OF WEAK DISTURBANCES ROUND ITS BASE AND MOVE NE OVER THE EASTERN CAROLINAS. WATER VAPOR LOOPS CONTINUE TO SHOW A TROPICAL PLUME OF MOISTURE ADVECTING NE OVER THE FORECAST AREA...ESPECIALLY OVER THE COASTAL PLAIN. MODEL SOUNDINGS ALSO CONTINUE TO SHOW A DEEPLY MOIST COLUMN THROUGH THE PERIOD...WITH A MODERATELY UNSTABLE AIRMASS AND P/W VALUES WELL IN EXCESS OF 2 INCHES. ALL ELEMENTS REMAIN IN PLACE FOR POTENTIAL WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY...WITH THE ATTENDANT HEAVY RAIN THREAT CONTINUING WELL INTO TODAY. GUIDANCE HAS BEEN WOEFULLY POOR LATELY IN CAPTURING THE UNUSUALLY LOW MAXIMUM TEMPERATURES BROUGHT ABOUT BY EXTENSIVE CLOUD COVER AND PRECIPITATION. SO...WILL GO SIGNIFICANTLY UNDER GUIDANCE BY LIMITING MAXIMUM TEMPERATURES TO THE LOWER 80S FOR TODAY. OVERNIGHT LOWS WILL HOVER AROUND 70. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 3 AM SUNDAY...MONDAYS FORECAST WILL NOW HINGE UPON WHAT MAY END UP BEING A COMPLEX (AND POORLY SAMPLED) INTERACTION BETWEEN TWO CIRCULATIONS OFF THE EAST COAST...BERTHA AND TROPICAL WAVE NOW IN THE BAHAMAS. WRF SCORED A BIT OF A COUP WHEN IT STARTED SHOWING THIS LAST NIGHT. THE QUESTION THAT NOW REMAINS TO BE SEEN...WHICH CIRCULATION BECOMES THE DOMINANT ONE? WRF MAINTAINS THAT IT WILL BE THE WESTERN SYSTEM AND THAT THE COAST IS IN FOR QUITE A RAINSTORM FOLLOWING A WET WEEKEND AND OUR CURRENT FLOOD WATCH WILL LIKELY NEED TO BE EXTENDED. BERTHA CURRENTLY UNDERGOING LAND INTERACTION WITH HISPANIOLA...AND SEEMINGLY MAINTAINING A FAIR AMOUNT OF CONVECTION...AND SO RIGHT NOW IT SEEMS THAT THE WRF IS A BIT EXTREME. GFS LAST NIGHT PRETTY MUCH IGNORED THE BAHAMA LOW BUT NOW GIVES IT AN IDENTITY THROUGH THE PERIOD WHILE SEEMINGLY PLAUSIBLY KEEPING BERTHA AS A SEPARATE ENTITY. THE MAIN PROBLEM WITH THE GFS IS IT SEEMS ERRONEOUSLY SLOW WITH THE WESTERN LOW AND SHOWS SURPRISINGLY LITTLE QPF FOR A SYSTEM THAT IS NOT ONLY OF TROPICAL ORIGIN BUT ALSO POSSIBLY TAPPING SOME MOISTURE FROM A TROPICAL STORM. THIS SYSTEM WILL LIKELY STILL BE PUSHING MOISTURE TOWARDS THE COAST MONDAY NIGHT INTO TUESDAY MORNING. TUESDAY AFTERNOON WILL BRING A DRYING TREND AT LEAST IN THE MID LEVELS. RAIN CHANCES WILL BE ON THE DECLINE AND THE AREA MAY START TO SEE SOME MORE BREAKS OF SUN THAN IT HAS RECENTLY. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS OF 3 PM SUNDAY...WEDNESDAY WILL OFFER UP SEASONABLY WARM WEATHER AND MINIMAL RAIN CHANCES. NEARLY ZONAL/WESTERLY MID LEVEL FLOW LOCALLY AROUND PERSISTENT TROUGHINESS IN THE NORTHEAST TO KEEP THINGS FAIRLY DRY. VERY LOW RAIN CHANCES COMING FROM SEA BREEZE AND PIEDMONT TROUGH WHERE AN ISOLATED SHOWER OR TSTM CANNOT BE RULED OUT. AFOREMENTIONED UPPER TROUGH SHARPENS ON THURSDAY DRIVING A LATE DAY COLD FRONT INTO THE REGION. WITH THE LACK OF MID LEVEL MOISTURE AND EVEN NO APPRECIABLE INFLUX OF GULF OR ATLANTIC LOW LEVEL MOISTURE AHEAD OF THE BOUNDARY ITS HARD TO IMAGINE HOW IT BRINGS AN APPRECIABLE INCREASE IN RAIN CHANCES. AS IT STALLS TO OUR SOUTH IT WILL USHER IN SOME COOLER AIR OVER THE WEEKEND. TOUGH TO SAY HOW MUCH PENDING HOW CLOUDY IT GETS VS THE ACTUAL AIRMASS CHANGE/COOL ADVECTION. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... AS OF 12Z...STALLED FRONT/TROUGH WILL CONTINUE OVER THE REGION WITH CONVECTION FIRING ALONG THE COAST ALL MORNING. INLAND TERMINALS WILL REMAIN IFR AT LEAST THROUGH 15Z...PERHAPS INTO THE AFTERNOON. PREDOMINATELY MVFR ALONG THE COAST WITH OCCASIONAL THUNDER POSSIBLE WITH BRIEF HEAVY RAIN. THE HRRR MODEL INDICATES PRECIP MAY MOVE INLAND FROM THE COAST BY NOON...BUT CONFIDENCE IS RATHER LOW. TONIGHT...SHOWERS WILL RETURN DUE TO AN INVERTED TROUGH FROM LOW PRESSURE MOVING UP FROM THE SOUTH. EXTENDED OUTLOOK...SHRA/TSRA LIKELY WITH PERIODS OF MVFR CONDITIONS THROUGH TUESDAY AS A FRONT STALLS AND FINALLY DISSIPATES OVER THE EASTERN CAROLINAS. A CHANCE OF SHOWERS CONTINUES ON WEDNESDAY LATE INTO THURSDAY MORNING. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 6:30 AM SUNDAY...NO CHANGES TO THE FORECAST WITH THE LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS: AN INVERTED TROUGH/TROPICAL WAVE FEATURE OVER THE WATERS IS KEEPING WINDS LIGHT AND VARIABLE WITH SEAS IN THE 3 FT RANGE. A NEARLY STATIONARY FRONT WILL REMAIN INLAND OR JUST NEAR THE COAST TODAY AND TONIGHT. WINDS WILL BECOME SOUTHEASTERLY LATER THIS MORNING IN THE 10 TO 15 KT RANGE...WITH SEAS REMAINING AROUND 3 FT. THESE CONDITIONS WILL PERSIST THROUGH THE NEAR TERM. EXPECT EXTENSIVE SHOWER AND THUNDERSTORM ACTIVITY OVER THE WATERS AS A TROPICAL PLUME OF MOISTURE MOVES NORTH ACROSS THE WATERS. SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 3 AM SUNDAY...PRETTY DIFFICULT FORECAST ON MONDAY. WINDS WILL BE MAINLY A FUNCTION OF THE INTERACTION BETWEEN BERTHA AND A TROPICAL WAVE NOW OVER THE BAHAMAS. MODEL SOLUTIONS VARY CONSIDERABLY AS TO HOW THESE TWO WILL INTERACT AND WHICH ONE WILL END UP BECOMING A DOMINANT CIRCULATION AS THEY BOTH PASS NORTHWARD ACROSS OUR LATITUDE ON MONDAY. BERTHA CURRENTLY INTERACTING WITH HISPANIOLA FURTHER COMPLICATING THE ISSUE. SOUTHEASTERLY WINDS SHOULD BE PREDOMINANT LOCALLY EITHER WAY...ALTHOUGH THE STRENGTH OF THESE WINDS AND TO A LESSER EXTENT THE MAGNITUDE OF SEAS REALIZED WILL BE MODULATED BY WHICH SYSTEM TAKES OVER. SHOULD IT BE BERTHA THEN THE CURRENT FCST APPLIES. SHOULD THE WESTWARD WAVE TAKE OVER THEN WINDS MAY BE A BIT HIGHER IN SPEED AND CHANGE MORE THROUGH THE DAY AS THE FCST ZONES EXPERIENCE MORE CLOSED ISOBARS. A SMALL CRAFT ADVISORY IS GETTING TOUGH TO RULE OUT ESP FOR NRN ZONES BUT THERE IS JUST TOO MUCH UNCERTAINTY TO RAISE AT THIS POINT. EITHER WAY WINDS SHOULD SWING AROUND TO THE NORTH AND THEN WEST ON TUESDAY AS THE SYSTEMS ACCELERATE OFF TO THE NORTH AND EAST. SUCH A TURN TO OFFSHORE OFTEN ACTS TO DIMINISH NEARSHORE SEAS AS LANDMASS WAVE SHADOWING TAKES OVER BUT THERE WILL BE ENOUGH BACKSWELL TO MINIMIZE THIS FOR MUCH OF TUESDAY. THE EXCEPTION SHOULD BE BRUNSWICK WATERS WHERE THERE WILL NOT ONLY BE WESTERLY SHADOWING OF WIND WAVES BUT ALSO A SWELL SHADOWING FROM CAPE FEAR. LONG TERM /WEDNESDAY THROUGH THURSDAY/... AS OF 3 PM SUNDAY...WEAK PIEDMONT TROUGHINESS TAKES SHAPE ON WEDNESDAY YIELDING A SOUTHWESTERLY WIND OF FAIRLY `SEASONABLE` SPEED. SEAS NORMALLY 2 TO 3 FT IN SUCH A SETUP BUT A REMNANT EASTERLY SWELL MAY STILL BE GIVING RISE TO 4 FT DOMINANT WAVES OVER NRN ZONES. THE TROUGH MOVES CLOSER TO THE COAST ON THURSDAY WHILE A COLD FRONT ALSO APPROACHES FROM THE NW. OVERALL THE GRADIENT WILL EASE AND THE FLOW MAY BACK TO SRLY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...FLOOD WATCH THROUGH THIS EVENING FOR SCZ017-023-024-032-033- 039-053>056. NC...FLOOD WATCH THROUGH THIS EVENING FOR NCZ087-096-099-105>110. MARINE...NONE. && $$ SYNOPSIS...MBB NEAR TERM...REK SHORT TERM...MBB LONG TERM...MBB AVIATION...43 MARINE...REK/MBB
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1255 PM CDT SUN AUG 3 2014 .UPDATE... ISSUED AT 1255 PM CDT SUN AUG 3 2014 AN UPPER LEVEL SHORTWAVE CONTINUES TO GENERATE ELEVATED SHOWER AND THUNDERSTORM ACTIVITY OVER PORTIONS OF WESTERN NORTH DAKOTA...MAINLY SOUTH OF THE MISSOURI RIVER. THE LATEST HRRR PROGS THESE STORMS TO CONTINUE TO MOVE EAST ACROSS SOUTH CENTRAL NORTH DAKOTA THIS AFTERNOON. THESE STORMS SHOULD CONTINUE TO REMAIN BELOW SEVERE LIMITS GIVEN THE ELEVATED NATURE OF THIS CONVECTION. UPDATED THE FORECAST TO INCREASE POPS FOR THE AFFECTED AREAS THIS AFTERNOON. NUMEROUS SHOWERS WILL CONTINUE TO MOVE EAST ACROSS CENTRAL NORTH DAKOTA THIS AFTERNOON...WITH SCATTERED EMBEDDED THUNDERSTORMS EXPECTED. UPDATE ISSUED AT 941 AM CDT SUN AUG 3 2014 SCATTERED TO NUMEROUS SHOWERS WITH EMBEDDED THUNDERSTORMS WILL CONTINUE TO MOVE EAST ACROSS WESTERN NORTH DAKOTA THIS MORNING. THIS ACTIVITY IS ASSOCIATED WITH AN UPPER LEVEL SHORTWAVE OVERTOPPING A RIDGE AXIS OVER EASTERN MONTANA. THE LATEST HRRR PROGS THIS ACTIVITY TO CONTINUE TO MOVE EAST OVER CENTRAL NORTH DAKOTA THROUGH THE AFTERNOON. THE INCREASED CLOUD COVER MAY INHIBIT DIABATIC FORCING FROM AFTERNOON HEATING. THIS WILL LIKELY KEEP AFTERNOON THUNDERSTORMS ELEVATED FOR THE MOST PART...KEEPING THE STRONG TO SEVERE POSSIBILITIES LOW. FOR NOW WILL KEEP THE ONGOING CONVECTIVE FORECAST AS IS...AND WILL CONTINUE TO MONITOR CONVECTIVE TRENDS THROUGH THE AFTERNOON. OTHERWISE...ONLY REMOVED MORNING FOG FROM THE ONGOING FORECAST. THE REMAINING FORECAST ELEMENTS ARE ON TRACK. THE UPDATED PRODUCTS HAVE BEEN SENT. UPDATE ISSUED AT 648 AM CDT SUN AUG 3 2014 FOLLOWING THE 08 AND 09 UTC HRRR AND 06 UTC NAM...THE CURRENT CONVECTION ACROSS NORTHEAST MONTANA IS FORECAST TO PROPAGATE SOUTHEAST ALONG THE LOW LEVEL INSTABILITY AXIS INTO SOUTH CENTRAL NORTH DAKOTA BY 19-20 UTC. GIVEN CURRENT CLOUD COVER SPREADING AHEAD OF THE CONVECTION...SURFACE DESTABILIZATION AND OVERALL INTENSIFICATION OF THIS CONVECTION INTO THE AFTERNOON WILL BE LIMITED. THEREAFTER...THE GENERAL CONSENSUS OF 00 UTC HIGH RESOLUTION AND GLOBAL GUIDANCE IS FOR A SECOND CONVECTIVE COMPLEX TO INITIATE ACROSS EASTERN MONTANA INTO SOUTHERN SASKATCHEWAN LATE THIS AFTERNOON/EVENING AND PROPAGATE AGAIN SOUTHEAST ALONG THE INSTABILITY AXIS INTO WESTERN AND CENTRAL NORTH DAKOTA TONIGHT. GIVEN A LIKELY ARRIVAL NEARING TO AFTER SUNSET...THE SEVERE THREAT WILL BE MARGINAL WITH THIS SECOND ROUND. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 341 AM CDT SUN AUG 3 2014 THE MAIN CONCERN IN THE SHORT TERM IS THUNDERSTORM CHANCES...AND THE POSSIBILITY THAT SEVERE STORMS ARE POSSIBLE TODAY AND TONIGHT. CURRENTLY...SURFACE HIGH PRESSURE WAS OVER MANITOBA WITH LOW PRESSURE ALONG THE FRONT RANGE OF THE ROCKIES. THE UPPER LEVEL RIDGE OVER THE ROCKIES AND THE TROUGH OVER HUDSON BAY WAS KEEPING THE NORTHWEST FLOW ALOFT OVER NORTH DAKOTA. AN EMBEDDED SHORTWAVE MOVING ACROSS MONTANA WAS ASSOCIATED WITH A CONVECTIVE LINE OF SHOWERS THAT WAS APPROACHING THE WESTERN BORDER OF NORTH DAKOTA. THE AFOREMENTIONED EASTERN MONTANA SHORTWAVE IS PROGGED TO MOVE EAST/SOUTHEAST ACROSS NORTH DAKOTA TODAY...FOLLOWED BY ANOTHER GROUP OF SHORTWAVES TONIGHT. THIS SETUP WILL KEEP SCATTERED THUNDERSTORMS IN THE FORECAST TODAY AND TONIGHT. CAPE VALUES LATE THIS MORNING AND AFTERNOON APPROACH OR EXCEED 2000 J/KG OVER WESTERN NORTH DAKOTA...WITH 0-6 KM BULK SHEAR VALUES OVER 40 KNOTS IN THE SAME AREA. THE STORM PREDICTION CENTER ASSESSMENT WAS THAT THE SEVERE THREAT WAS MARGINAL AND FOR ISOLATED COVERAGE. WILL MENTION THIS THREAT IN THE HAZARDOUS WEATHER OUTLOOK...BUT CONFIDENCE NOT HIGH ENOUGH TO MENTION IN GRAPHICAL FORECAST. IN THE EARLY MORNING HOURS TODAY...SURFACE DEWPOINT TEMPERATURES WERE IN THE UPPER 50S AND LOWER 60S. EARLIER FORECAST PACKAGE MENTIONED THE POSSIBILITY OF PATCHY/AREAS OF FOG...AND WILL KEEP THIS MENTIONED IN THIS MORNING`S FORECAST PACKAGE AS WELL. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 341 AM CDT SUN AUG 3 2014 RATHER NORMAL SENSIBLE SUMMER WEATHER HIGHLIGHTS THE EXTENDED FORECAST. THE 00 UTC GUIDANCE SUITE IS IN AGREEMENT ON THE LARGE SCALE PATTERN OF A BROAD...LOW AMPLITUDE RIDGE ACROSS THE WESTERN AND CENTRAL CONUS...CONTAINING WITHIN IT MULTIPLE LOW PREDICTABILITY IMPULSES THROUGH THE EXTENDED FORECAST. ALL FIELDS ARE WITHIN ONE AND A HALF STANDARD DEVIATIONS OR LESS OF NORMAL...SUGGESTING RATHER AVERAGE EARLY AUGUST WEATHER WITH DAILY ISOLATED TO SCATTERED THUNDERSTORMS...GIVEN THE AFOREMENTIONED IMPULSES...AND HIGHS IN THE UPPER 70S TO MID 80S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1255 PM CDT SUN AUG 3 2014 LIFR CONDITIONS IN THUNDERSTORMS HAVE JUST NOW ENDED OVER KDIK. THIS CONVECTION WILL CONTINUE TO MOVE EAST ACROSS SOUTH CENTRAL NORTH DAKOTA THROUGH THE AFTERNOON AND SHOULD IMPACT KBIS BETWEEN 20Z-22Z WITH IFR CONDITIONS...AND COULD BE INTO KJMS BY 23Z. HOWEVER...THE STORMS SHOULD BE WEAKER BY THE TIME THEY REACH KJMS AND WILL LIKELY HAVE LESS OF AN IMPACT. ANOTHER ROUND OF THUNDERSTORMS WILL BE POSSIBLE AFTER MIDNIGHT TONIGHT MOVING FROM NORTHWEST NORTH DAKOTA INTO SOUTHEASTERN NORTH DAKOTA THROUGH THE MONDAY MORNING HOURS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...TM SHORT TERM...JV LONG TERM...AYD AVIATION...TM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
941 AM CDT SUN AUG 3 2014 .UPDATE... ISSUED AT 941 AM CDT SUN AUG 3 2014 SCATTERED TO NUMEROUS SHOWERS WITH EMBEDDED THUNDERSTORMS WILL CONTINUE TO MOVE EAST ACROSS WESTERN NORTH DAKOTA THIS MORNING. THIS ACTIVITY IS ASSOCIATED WITH AN UPPER LEVEL SHORTWAVE OVERTOPPING A RIDGE AXIS OVER EASTERN MONTANA. THE LATEST HRRR PROGS THIS ACTIVITY TO CONTINUE TO MOVE EAST OVER CENTRAL NORTH DAKOTA THROUGH THE AFTERNOON. THE INCREASED CLOUD COVER MAY INHIBIT DIABATIC FORCING FROM AFTERNOON HEATING. THIS WILL LIKELY KEEP AFTERNOON THUNDERSTORMS ELEVATED FOR THE MOST PART...KEEPING THE STRONG TO SEVERE POSSIBILITIES LOW. FOR NOW WILL KEEP THE ONGOING CONVECTIVE FORECAST AS IS...AND WILL CONTINUE TO MONITOR CONVECTIVE TRENDS THROUGH THE AFTERNOON. OTHERWISE...ONLY REMOVED MORNING FOG FROM THE ONGOING FORECAST. THE REMAINING FORECAST ELEMENTS ARE ON TRACK. THE UPDATED PRODUCTS HAVE BEEN SENT. UPDATE ISSUED AT 648 AM CDT SUN AUG 3 2014 FOLLOWING THE 08 AND 09 UTC HRRR AND 06 UTC NAM...THE CURRENT CONVECTION ACROSS NORTHEAST MONTANA IS FORECAST TO PROPAGATE SOUTHEAST ALONG THE LOW LEVEL INSTABILITY AXIS INTO SOUTH CENTRAL NORTH DAKOTA BY 19-20 UTC. GIVEN CURRENT CLOUD COVER SPREADING AHEAD OF THE CONVECTION...SURFACE DESTABILIZATION AND OVERALL INTENSIFICATION OF THIS CONVECTION INTO THE AFTERNOON WILL BE LIMITED. THEREAFTER...THE GENERAL CONSENSUS OF 00 UTC HIGH RESOLUTION AND GLOBAL GUIDANCE IS FOR A SECOND CONVECTIVE COMPLEX TO INITIATE ACROSS EASTERN MONTANA INTO SOUTHERN SASKATCHEWAN LATE THIS AFTERNOON/EVENING AND PROPAGATE AGAIN SOUTHEAST ALONG THE INSTABILITY AXIS INTO WESTERN AND CENTRAL NORTH DAKOTA TONIGHT. GIVEN A LIKELY ARRIVAL NEARING TO AFTER SUNSET...THE SEVERE THREAT WILL BE MARGINAL WITH THIS SECOND ROUND. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 341 AM CDT SUN AUG 3 2014 THE MAIN CONCERN IN THE SHORT TERM IS THUNDERSTORM CHANCES...AND THE POSSIBILITY THAT SEVERE STORMS ARE POSSIBLE TODAY AND TONIGHT. CURRENTLY...SURFACE HIGH PRESSURE WAS OVER MANITOBA WITH LOW PRESSURE ALONG THE FRONT RANGE OF THE ROCKIES. THE UPPER LEVEL RIDGE OVER THE ROCKIES AND THE TROUGH OVER HUDSON BAY WAS KEEPING THE NORTHWEST FLOW ALOFT OVER NORTH DAKOTA. AN EMBEDDED SHORTWAVE MOVING ACROSS MONTANA WAS ASSOCIATED WITH A CONVECTIVE LINE OF SHOWERS THAT WAS APPROACHING THE WESTERN BORDER OF NORTH DAKOTA. THE AFOREMENTIONED EASTERN MONTANA SHORTWAVE IS PROGGED TO MOVE EAST/SOUTHEAST ACROSS NORTH DAKOTA TODAY...FOLLOWED BY ANOTHER GROUP OF SHORTWAVES TONIGHT. THIS SETUP WILL KEEP SCATTERED THUNDERSTORMS IN THE FORECAST TODAY AND TONIGHT. CAPE VALUES LATE THIS MORNING AND AFTERNOON APPROACH OR EXCEED 2000 J/KG OVER WESTERN NORTH DAKOTA...WITH 0-6 KM BULK SHEAR VALUES OVER 40 KNOTS IN THE SAME AREA. THE STORM PREDICTION CENTER ASSESSMENT WAS THAT THE SEVERE THREAT WAS MARGINAL AND FOR ISOLATED COVERAGE. WILL MENTION THIS THREAT IN THE HAZARDOUS WEATHER OUTLOOK...BUT CONFIDENCE NOT HIGH ENOUGH TO MENTION IN GRAPHICAL FORECAST. IN THE EARLY MORNING HOURS TODAY...SURFACE DEWPOINT TEMPERATURES WERE IN THE UPPER 50S AND LOWER 60S. EARLIER FORECAST PACKAGE MENTIONED THE POSSIBILITY OF PATCHY/AREAS OF FOG...AND WILL KEEP THIS MENTIONED IN THIS MORNING`S FORECAST PACKAGE AS WELL. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 341 AM CDT SUN AUG 3 2014 RATHER NORMAL SENSIBLE SUMMER WEATHER HIGHLIGHTS THE EXTENDED FORECAST. THE 00 UTC GUIDANCE SUITE IS IN AGREEMENT ON THE LARGE SCALE PATTERN OF A BROAD...LOW AMPLITUDE RIDGE ACROSS THE WESTERN AND CENTRAL CONUS...CONTAINING WITHIN IT MULTIPLE LOW PREDICTABILITY IMPULSES THROUGH THE EXTENDED FORECAST. ALL FIELDS ARE WITHIN ONE AND A HALF STANDARD DEVIATIONS OR LESS OF NORMAL...SUGGESTING RATHER AVERAGE EARLY AUGUST WEATHER WITH DAILY ISOLATED TO SCATTERED THUNDERSTORMS...GIVEN THE AFOREMENTIONED IMPULSES...AND HIGHS IN THE UPPER 70S TO MID 80S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 648 AM CDT SUN AUG 3 2014 HIGH PRESSURE OVER MANITOBA AND LOW PRESSURE OVER THE FRONT RANGE WILL KEEP AN EASTERLY WIND FLOW ACROSS THE TAF SITES. EARLY THIS MORNING FOG WITH MVFR AND IFR VSBYS AT KDIK...AND MVFR VSBYS AT KBIS/KMOT/KJMS. AREA OF SHOWERS AND THUNDERSTORMS IN EASTERN MONTANA SHOULD MOVE INTO KISN AFT 13Z...WITH CHANCES OF THUNDERSTORMS AFT 16-18Z AT KMOT/KDIK/KBIS...AND NOT UNTIL TONIGHT AT KJMS. VCTS CONTINUES THROUGH THE TAF PERIOD. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...TM SHORT TERM...JV LONG TERM...AYD AVIATION...JV
AREA FORECAST DISCUSSION
NWS BISMARCK ND
649 AM CDT SUN AUG 3 2014 .UPDATE... ISSUED AT 648 AM CDT SUN AUG 3 2014 FOLLOWING THE 08 AND 09 UTC HRRR AND 06 UTC NAM...THE CURRENT CONVECTION ACROSS NORTHEAST MONTANA IS FORECAST TO PROPAGATE SOUTHEAST ALONG THE LOW LEVEL INSTABILITY AXIS INTO SOUTH CENTRAL NORTH DAKOTA BY 19-20 UTC. GIVEN CURRENT CLOUD COVER SPREADING AHEAD OF THE CONVECTION...SURFACE DESTABILIZATION AND OVERALL INTENSIFICATION OF THIS CONVECTION INTO THE AFTERNOON WILL BE LIMITED. THEREAFTER...THE GENERAL CONSENSUS OF 00 UTC HIGH RESOLUTION AND GLOBAL GUIDANCE IS FOR A SECOND CONVECTIVE COMPLEX TO INITIATE ACROSS EASTERN MONTANA INTO SOUTHERN SASKATCHEWAN LATE THIS AFTERNOON/EVENING AND PROPAGATE AGAIN SOUTHEAST ALONG THE INSTABILITY AXIS INTO WESTERN AND CENTRAL NORTH DAKOTA TONIGHT. GIVEN A LIKELY ARRIVAL NEARING TO AFTER SUNSET...THE SEVERE THREAT WILL BE MARGINAL WITH THIS SECOND ROUND. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 341 AM CDT SUN AUG 3 2014 THE MAIN CONCERN IN THE SHORT TERM IS THUNDERSTORM CHANCES...AND THE POSSIBILITY THAT SEVERE STORMS ARE POSSIBLE TODAY AND TONIGHT. CURRENTLY...SURFACE HIGH PRESSURE WAS OVER MANITOBA WITH LOW PRESSURE ALONG THE FRONT RANGE OF THE ROCKIES. THE UPPER LEVEL RIDGE OVER THE ROCKIES AND THE TROUGH OVER HUDSON BAY WAS KEEPING THE NORTHWEST FLOW ALOFT OVER NORTH DAKOTA. AN EMBEDDED SHORTWAVE MOVING ACROSS MONTANA WAS ASSOCIATED WITH A CONVECTIVE LINE OF SHOWERS THAT WAS APPROACHING THE WESTERN BORDER OF NORTH DAKOTA. THE AFOREMENTIONED EASTERN MONTANA SHORTWAVE IS PROGGED TO MOVE EAST/SOUTHEAST ACROSS NORTH DAKOTA TODAY...FOLLOWED BY ANOTHER GROUP OF SHORTWAVES TONIGHT. THIS SETUP WILL KEEP SCATTERED THUNDERSTORMS IN THE FORECAST TODAY AND TONIGHT. CAPE VALUES LATE THIS MORNING AND AFTERNOON APPROACH OR EXCEED 2000 J/KG OVER WESTERN NORTH DAKOTA...WITH 0-6 KM BULK SHEAR VALUES OVER 40 KNOTS IN THE SAME AREA. THE STORM PREDICTION CENTER ASSESSMENT WAS THAT THE SEVERE THREAT WAS MARGINAL AND FOR ISOLATED COVERAGE. WILL MENTION THIS THREAT IN THE HAZARDOUS WEATHER OUTLOOK...BUT CONFIDENCE NOT HIGH ENOUGH TO MENTION IN GRAPHICAL FORECAST. IN THE EARLY MORNING HOURS TODAY...SURFACE DEWPOINT TEMPERATURES WERE IN THE UPPER 50S AND LOWER 60S. EARLIER FORECAST PACKAGE MENTIONED THE POSSIBILITY OF PATCHY/AREAS OF FOG...AND WILL KEEP THIS MENTIONED IN THIS MORNING`S FORECAST PACKAGE AS WELL. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 341 AM CDT SUN AUG 3 2014 RATHER NORMAL SENSIBLE SUMMER WEATHER HIGHLIGHTS THE EXTENDED FORECAST. THE 00 UTC GUIDANCE SUITE IS IN AGREEMENT ON THE LARGE SCALE PATTERN OF A BROAD...LOW AMPLITUDE RIDGE ACROSS THE WESTERN AND CENTRAL CONUS...CONTAINING WITHIN IT MULTIPLE LOW PREDICTABILITY IMPULSES THROUGH THE EXTENDED FORECAST. ALL FIELDS ARE WITHIN ONE AND A HALF STANDARD DEVIATIONS OR LESS OF NORMAL...SUGGESTING RATHER AVERAGE EARLY AUGUST WEATHER WITH DAILY ISOLATED TO SCATTERED THUNDERSTORMS...GIVEN THE AFOREMENTIONED IMPULSES...AND HIGHS IN THE UPPER 70S TO MID 80S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 648 AM CDT SUN AUG 3 2014 HIGH PRESSURE OVER MANITOBA AND LOW PRESSURE OVER THE FRONT RANGE WILL KEEP AN EASTERLY WIND FLOW ACROSS THE TAF SITES. EARLY THIS MORNING FOG WITH MVFR AND IFR VSBYS AT KDIK...AND MVFR VSBYS AT KBIS/KMOT/KJMS. AREA OF SHOWERS AND THUNDERSTORMS IN EASTERN MONTANA SHOULD MOVE INTO KISN AFT 13Z...WITH CHANCES OF THUNDERSTORMS AFT 16-18Z AT KMOT/KDIK/KBIS...AND NOT UNTIL TONIGHT AT KJMS. VCTS CONTINUES THROUGH THE TAF PERIOD. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AYD SHORT TERM...JV LONG TERM...AYD AVIATION...JV
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
722 AM EDT SUN AUG 3 2014 .SYNOPSIS... AN AREA OF LOW PRESSURE MOVING UP THE EAST COAST WILL SPREAD MOISTURE WEST INTO THE LOCAL AREA THIS MORNING. HIGH PRESSURE TO THE WEST WILL BEGIN TO BUILD OVER THE REGION THIS AFTERNOON AND THEN WILL MOVE ACROSS THE UPPER OHIO VALLEY ON MONDAY. A COLD FRONT WILL SLIDE SOUTHEAST INTO THE REGION TUESDAY INTO TUESDAY NIGHT. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... HAVE BACKED OFF ON PRECIP A LITTLE ALONG THE I-71 CORRIDOR. THE LATEST HRRR STILL SHOWS PRECIP REACHING KCLE IN A COUPLE OF HOURS. ALSO ADDED A MENTION OF FOG TO THE KMFD AREA. PREVIOUS...AS EXPECTED SHOWERS HAVE REDEVELOPED OVER THE EASTERN THIRD OF THE AREA AS A VORT MAX ROTATES ACROSS THE AREA. EXPECT THE COVERAGE TO CONTINUE TO INCREASE AND SPREAD WEST. HAVE PUSHED PRECIP CHANCES WESTWARD TO THE I-71 CORRIDOR WITH LIKELY POPS OVER NE OH AND NW PA. THE CURRENT ROUND OF SHOWERS WILL WORK THE ATMOSPHERE OVER AND NOT EXPECTING MUCH IF ANY THUNDER GIVEN THE LACK OF CAPE. THE PRECIP SHOULD START TO DIMINISH AFTER MIDDAY AND EXPECT MAINLY DRY WEATHER BY 00Z. THE INTENSITY OF THE PRECIP SHOULD BE MUCH LESS THAN YESTERDAY AND DO NOT EXPECT FLOODING TO BE AN ISSUE TODAY. WEAK HIGH PRESSURE WILL DOMINATE IN THE FAR WEST TODAY AND A LOT OF SUNSHINE IS EXPECTED. THAT SHOULD PUSH TEMPS INTO THE LOWER 80S. THE EASTERN END OF THE AREA WILL BE LUCKY TO GET INTO THE MIDDLE 70S. HAVE USED A BLEND OF GUIDANCE TEMPS AGAIN TODAY. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... THE AREA WILL ENJOY A 24 TO 36 HOUR PERIOD OF DRY WEATHER AS HIGH PRESSURE BUILDS OVER THE REGION. A COLD FRONT IS STILL ON TRACK TO MOVE ACROSS THE REGION ON TUESDAY. MOISTURE WILL BEGIN TO INCREASE LATE TOMORROW...ESPECIALLY IN THE NW. THE LATEST GUIDANCE CONTINUES TO HINT AT PRECIP JUST NORTH OF KTOL TOMORROW EVENING. WILL PUT A 20 POP IN FOR A FEW HOURS FOR THAT AREA BUT NOT REALLY EXPECTING MUCH. MONDAY NIGHT SHOULD BE DRY BUT PRECIP CHANCES WILL RAMP UP ON TUESDAY. WILL GO WITH CHANCE POPS FOR NOW BUT MAY EVENTUALLY NEED LIKELY WORDING...ESPECIALLY IN THE SOUTH. WILL SEE SOME LINGERING PRECIP TUESDAY. STILL GETTING MIXED SIGNALS FROM THE MODELS FOR WEDNESDAY. SOME OF THE GUIDANCE SUGGESTS THE FRONT STALLING OUT WITH CONTINUING PRECIP CHANCES. THE PREVIOUS FORECAST HAD MAINLY DRY WEATHER AND WILL BE OPTIMISTIC AND STICK WITH THAT SCENARIO FOR THE TIME BEING. TEMPERATURES DURING THE PERIOD SHOULD BE WITHIN A DEGREE OR TWO OF NORMAL. && .LONG TERM /THURSDAY THROUGH SATURDAY/... UPPER LEVEL TROUGH WILL MOVE EAST OF THE REGION THURSDAY NIGHT WITH LARGE AREA OF SURFACE HIGH PRESSURE BUILDING BUILDING OVER THE GREAT LAKES. YDY THE ECMWF MOVED LOW PRESSURE ACROSS FORECAST AREA ON FRIDAY...NOW KEEPS HIGH PRESSURE IN PLACE FORCING THE LOW SOUTH OF THE FORECAST AREA. NOW BOTH MODELS SOLUTION SIMILAR...WITH HIGH PRESSURE BECOMING ANCHORED OVER THE EASTERN LAKES THROUGH THE EXTENDED PERIOD. THIS WILL CONTINUE TO PROVIDE A DRY FORECAST WITH BELOW NORMAL TEMPS. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... EASTERN 2/3 FORECAST AREA SHROUDED BY SCATTERED SHRA...BR AND STRATUS. CONDITIONS WILL SLOWLY IMPROVE FROM THE WEST DURING THE DAY AS THE UPPER LEVEL SHORT WAVE OVER OHIO DRIFTS EAST OF THE AREA THIS AFTERNOON. OUTLOOK...NON VFR POSSIBLE TONIGHT IN BR AND STRATUS...AGAIN TUESDAY IN SHOWERS/THUNDERSTORMS. && .MARINE... WEAK HIGH PRESSURE WILL REMAIN OVER THE LAKE THROUGH MONDAY PROVIDING LIGHT WINDS ACROSS THE LAKE. MODELS CONTINUE TO PUSH WEAK COLD FRONT ACROSS THE LAKE LATE TUESDAY. THIS MAY PRODUCE SOME ISOLATED TO SCATTERED THUNDERSTORMS. AFTER THIS HIGH PRESSURE WILL THEN REESTABLISH ITSELF OVER THE LAKE INTO NEXT WEEKEND. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...KUBINA NEAR TERM...KUBINA SHORT TERM...KUBINA LONG TERM...DJB AVIATION...DJB MARINE...DJB
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
625 AM EDT SUN AUG 3 2014 .SYNOPSIS... AN AREA OF LOW PRESSURE MOVING UP THE EAST COAST WILL SPREAD MOISTURE WEST INTO THE LOCAL AREA THIS MORNING. HIGH PRESSURE TO THE WEST WILL BEGIN TO BUILD OVER THE REGION THIS AFTERNOON AND THEN WILL MOVE ACROSS THE UPPER OHIO VALLEY ON MONDAY. A COLD FRONT WILL SLIDE SOUTHEAST INTO THE REGION TUESDAY INTO TUESDAY NIGHT. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... HAVE BACKED OFF ON PRECIP A LITTLE ALONG THE I-71 CORRIDOR. THE LATEST HRRR STILL SHOWS PRECIP REACHING KCLE IN A COUPLE OF HOURS. ALSO ADDED A MENTION OF FOG TO THE KMFD AREA. PREVIOUS...AS EXPECTED SHOWERS HAVE REDEVELOPED OVER THE EASTERN THIRD OF THE AREA AS A VORT MAX ROTATES ACROSS THE AREA. EXPECT THE COVERAGE TO CONTINUE TO INCREASE AND SPREAD WEST. HAVE PUSHED PRECIP CHANCES WESTWARD TO THE I-71 CORRIDOR WITH LIKELY POPS OVER NE OH AND NW PA. THE CURRENT ROUND OF SHOWERS WILL WORK THE ATMOSPHERE OVER AND NOT EXPECTING MUCH IF ANY THUNDER GIVEN THE LACK OF CAPE. THE PRECIP SHOULD START TO DIMINISH AFTER MIDDAY AND EXPECT MAINLY DRY WEATHER BY 00Z. THE INTENSITY OF THE PRECIP SHOULD BE MUCH LESS THAN YESTERDAY AND DO NOT EXPECT FLOODING TO BE AN ISSUE TODAY. WEAK HIGH PRESSURE WILL DOMINATE IN THE FAR WEST TODAY AND A LOT OF SUNSHINE IS EXPECTED. THAT SHOULD PUSH TEMPS INTO THE LOWER 80S. THE EASTERN END OF THE AREA WILL BE LUCKY TO GET INTO THE MIDDLE 70S. HAVE USED A BLEND OF GUIDANCE TEMPS AGAIN TODAY. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... THE AREA WILL ENJOY A 24 TO 36 HOUR PERIOD OF DRY WEATHER AS HIGH PRESSURE BUILDS OVER THE REGION. A COLD FRONT IS STILL ON TRACK TO MOVE ACROSS THE REGION ON TUESDAY. MOISTURE WILL BEGIN TO INCREASE LATE TOMORROW...ESPECIALLY IN THE NW. THE LATEST GUIDANCE CONTINUES TO HINT AT PRECIP JUST NORTH OF KTOL TOMORROW EVENING. WILL PUT A 20 POP IN FOR A FEW HOURS FOR THAT AREA BUT NOT REALLY EXPECTING MUCH. MONDAY NIGHT SHOULD BE DRY BUT PRECIP CHANCES WILL RAMP UP ON TUESDAY. WILL GO WITH CHANCE POPS FOR NOW BUT MAY EVENTUALLY NEED LIKELY WORDING...ESPECIALLY IN THE SOUTH. WILL SEE SOME LINGERING PRECIP TUESDAY. STILL GETTING MIXED SIGNALS FROM THE MODELS FOR WEDNESDAY. SOME OF THE GUIDANCE SUGGESTS THE FRONT STALLING OUT WITH CONTINUING PRECIP CHANCES. THE PREVIOUS FORECAST HAD MAINLY DRY WEATHER AND WILL BE OPTIMISTIC AND STICK WITH THAT SCENARIO FOR THE TIME BEING. TEMPERATURES DURING THE PERIOD SHOULD BE WITHIN A DEGREE OR TWO OF NORMAL. && .LONG TERM /THURSDAY THROUGH SATURDAY/... UPPER LEVEL TROUGH WILL MOVE EAST OF THE REGION THURSDAY NIGHT WITH LARGE AREA OF SURFACE HIGH PRESSURE BUILDING BUILDING OVER THE GREAT LAKES. YDY THE ECMWF MOVED LOW PRESSURE ACROSS FORECAST AREA ON FRIDAY...NOW KEEPS HIGH PRESSURE IN PLACE FORCING THE LOW SOUTH OF THE FORECAST AREA. NOW BOTH MODELS SOLUTION SIMILAR...WITH HIGH PRESSURE BECOMING ANCHORED OVER THE EASTERN LAKES THROUGH THE EXTENDED PERIOD. THIS WILL CONTINUE TO PROVIDE A DRY FORECAST WITH BELOW NORMAL TEMPS. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... THE UPPER LEVEL SHORT WAVE OVER CENTRAL OHIO WILL DRIFT EAST OF THE AREA THIS AFTERNOON...BUT WILL BE ENOUGH TO PRODUCE SHOWERS OVER THE EASTERN HALF OF THE FORECAST AREA THIS MORNING. CLOUDS WILL SLOWLY ERODE FROM THE WEST AS SHORT WAVE DRIFTS EAST. IN AREAS WHERE CLOUDS SCATTER LIKELY SEE MVFR BR WITH AREAS OF IFR FOG...POTENTIALLY LI FR. THE FOG WILL BURN OFF MID MORNING AND CUMULUS WILL DEVELOP WITH THE DAYTIME HEATING. OUTLOOK...NON VFR POSSIBLE TUESDAY IN SHOWERS/THUNDERSTORMS. && .MARINE... WEAK HIGH PRESSURE WILL REMAIN OVER THE LAKE THROUGH MONDAY PROVIDING LIGHT WINDS ACROSS THE LAKE. MODELS CONTINUE TO PUSH WEAK COLD FRONT ACROSS THE LAKE LATE TUESDAY. THIS MAY PRODUCE SOME ISOLATED TO SCATTERED THUNDERSTORMS. AFTER THIS HIGH PRESSURE WILL THEN REESTABLISH ITSELF OVER THE LAKE INTO NEXT WEEKEND. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...KUBINA NEAR TERM...KUBINA SHORT TERM...KUBINA LONG TERM...DJB AVIATION...DJB MARINE...DJB
AREA FORECAST DISCUSSION
NWS MEDFORD OR
847 PM PDT MON AUG 4 2014 .DISCUSSION...RICH MOISTURE LADEN AIR MASS CROSSED OVER MOST AREAS EAST OF THE CASCADES. FAIRLY SIGNIFICANT CONVECTION ON THE LEADING EDGE OF THE MOISTURE. RADAR INDICATES SOME RAINFALL TOTALS OF OVER 1.50 INCHES. IF, OR WHEN, THIS HEAVY RAIN CROSSES A RECENT BURN AREA LOCAL FLASH FLOODING MAY RESULT. SHORT RANGE MODELS KEEP THE MOISTURE MAINLY EAST OF THE CASCADES IN OREGON AND CENTRAL SISKIYOU COUNTY IN CALIFORNIA. && .AVIATION...FOR THE 05/00Z TAFS...SMOKE WILL CONTINUE TO AFFECT VISIBILITY OVER PORTIONS OF SOUTHWEST OREGON AND NORTHERN CALIFORNIA. HOWEVER, THE TERMINALS ARE NOT HAVING ANY RESTRICTIONS. IFR CIGS IN STRATUS WILL IMPACT THE COAST (INCLUDING KOTH) TONIGHT AND TUESDAY. THE STRATUS WILL DISSIPATE TO NEAR THE BEACHES BY AFTERNOON. SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP INLAND TUESDAY AFTERNOON MAINLY NEAR AND EAST OF THE CASCADES AND ACROSS NORTHERN CALIFORNIA. CIGS AND VIS WILL BE VFR OUTSIDE STORMS, BUT STORMS MAY BRING HEAVY RAIN WITH POSSIBLE MVFR OR EVEN IFR CIGS AND VIS THROUGH THE NIGHT. JBL && .MARINE...UPDATED 900 PM PDT 4 AUG 2014... A THERMAL TROUGH PATTERN ALONG THE COAST WITH HIGH PRESSURE OFFSHORE WILL MAINTAIN GUSTY NORTH WINDS AND ELEVATED SEAS THROUGH THE WEEK...MAINLY ACROSS THE WATERS SOUTH OF CAPE BLANCO. VERY STEEP SEAS WILL BE CONFINED TO AREAS BEYOND 10NM FROM SHORE AND SOUTH OF GOLD BEACH. THE THERMAL TROUGH PATTERN WILL STRENGTHEN WEDNESDAY INTO FRIDAY...SO INCREASING WINDS AND SEAS ARE EXPECTED. JBL && .PREV DISCUSSION... /ISSUED 259 PM PDT MON AUG 4 2014/ DISCUSSION...WATER VAPOR IMAGERY IS SHOWING A LARGE PLUME OF MONSOONAL MOISTURE LIFTING NORTHWARD THROUGH NORTHERN CALIFORNIA AND INTO OREGON THIS AFTERNOON. THIN CIRRUS AND WILDFIRE SMOKE HAS BEEN INHIBITING SURFACE HEATING A BIT EARLY THIS AFTERNOON, BUT RADAR IMAGERY IS NOW SHOWING SOME SHOWER/THUNDERSTORM DEVELOPMENT IN LAKE AND MODOC COUNTIES. THIS ACTIVITY WILL CONTINUE TO ENHANCE THIS AFTERNOON AND MOVE TO THE WEST SOUTHWEST THROUGH THIS EVENING. INSTABILITY WILL ALSO CONTINUE TO INCREASE FROM SISKIYOU COUNTY NORTHWARD UP ALONG THE CASCADES AND EXPECT THUNDERSTORMS TO DEVELOP THERE TOO AS THE CAP ERODES. THERE IS STILL A SIGNIFICANT THREAT FOR A LOT OF LIGHTNING WITH THESE STORMS AND AS A RESULT, WE ARE MAINTAINING THE RED FLAG WARNING THROUGH THE FIRST PART OF TONIGHT (2AM PDT). WITH THE UPPER LOW NEAR TAHOE, THE FLOW ALOFT IS FAIRLY LIGHT OUT OF THE NORTHEAST, SO STORM MOTIONS WILL BE ON THE SLOW SIDE. PRECIPITABLE WATER VALUES OVER A BROAD AREA ARE 1.00-1.25 INCHES, SO STORMS THAT DO DEVELOP WILL PRODUCE RAINFALL. DUE TO SLOW STORM MOTIONS, SOME OF THE STRONGER STORMS WILL HAVE THE CAPABILITY OF PRODUCING VERY HEAVY RAINFALL. THIS MAY PRESENT A FLASH FLOOD THREAT...ESPECIALLY TO AREAS THAT HAVE PREVIOUSLY BURNED. WITH THE SOUTHWESTWARD MOVEMENT, SOME STORMS THAT FORM OVER THE CASCADES AND THE EAST SIDE THIS AFTERNOON MAY DRIFT OVER THE ROGUE VALLEY THIS EVENING. LATEST HRRR GUIDANCE IS INDICATING THAT MANY OF THE STORMS THAT GET GOING THIS AFTERNOON AND EVENING WILL MORPH INTO AN AREA OF SHOWERS WITH EMBEDDED THUNDER LATE TONIGHT INTO TUESDAY MORNING AS IT CONTINUES TO SAG SLOWLY SOUTHWESTWARD. THIS SEEMS REASONABLE AS WE LOSE THE DAYTIME INSTABILITY AND THE AXIS OF DEFORMATION STARTS TO SHIFT SOUTHWARD. WE EXPECT THE BEST THUNDERSTORM PROBABILITIES TO SHIFT SOUTHEASTWARD TUESDAY AFTERNOON AND EVENING AS THE UPPER LOW FILLS AND THE DEFORMATION AXIS CONTINUES SOUTHEASTWARD...BUT STILL EXPECT SOME DEVELOPMENT IN NORTHERN CALIFORNIA AND PORTIONS OF SOUTHERN KLAMATH AND LAKE COUNTIES. WE HAVE DECIDED TO WAIT TO SEE HOW MUCH LIGHTNING AND RAINFALL WE GET WITH TODAY`S STORMS AND HAVE PUSHED BACK THE START TIME OF TUESDAY`S FIRE WEATHER WATCH TO 18Z. MUCH WILL DEPEND ON HOW MUCH RESIDUAL CLOUD COVER REMAINS IN THE MORNING AND IF WE CAN GET SOME SUN TO DESTABILIZE THE ATMOSPHERE FOR THE AFTERNOON. WEST TO NORTHWEST FLOW ALOFT WILL BEGIN TO MOVE INTO NORTHWESTERN SECTIONS OF THE CWA TUESDAY, SO WE`RE NOT EXPECTING ANY DEVELOPMENT WEST OF THE CASCADES. BY WEDNESDAY, THERE IS STILL A SLIGHT CHANCE OF THUNDERSTORMS ACROSS SOUTH AND EAST SECTIONS OF THE CWA, BUT THE REST OF THE AREA WILL BE DRY AS NORTHWESTERLY FLOW ALOFT TAKES OVER. WE SHOULD CATCH A BREAK THURSDAY WITH ACTIVITY STAYING MOSTLY SOUTH WITH NEAREST ISOLATED ACTIVITY POPPING UP ALONG THE SIERRAS/LASSEN AREA SOUTH OF THE CWA. FRIDAY THROUGH THE WEEKEND...AN UPPER TROUGH WILL DEVELOP NEAR THE NORTHWEST CALIFORNIA COAST AND THIS MAY DEVELOP INTO ANOTHER UPPER LEVEL LOW. THIS WILL INCREASE THUNDERSTORM CHANCES AGAIN OVER THE MOUNTAINS AND FROM THE CASCADES EASTWARD. SPILDE && .MFR WATCHES/WARNINGS/ADVISORIES... OR...RED FLAG WARNING UNTIL 2 AM PDT TUESDAY FOR ORZ617-621>625. FIRE WEATHER WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR ORZ623>625. CA...RED FLAG WARNING UNTIL 2 AM PDT TUESDAY FOR CAZ280>282-284-285. FIRE WEATHER WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR CAZ280>282-284-285. PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 PM PDT THURSDAY FOR PZZ356-376. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT THURSDAY FOR PZZ356-376. HAZARDOUS SEAS WARNING UNTIL 11 PM PDT THIS EVENING FOR PZZ376. $$
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1244 PM CDT SUN AUG 3 2014 .UPDATE... ISSUED AT 956 AM CDT SUN AUG 3 2014 HAVE MADE MINOR ADJUSTMENTS TO THE FORECAST. VIS AND WATER VAPOR IMAGERY SHOWS TWO WAVE MOVES IN THE NORTHERN PLAINS. THE FIRST IS IN THE RED RIVER VALLEY WITH SOME CONVECTION ASSOCIATED WITH IT. A STRONGER WAVE WAS JUST MOVING INTO THE WESTERN DAKOTAS. SKIES ARE CURRENTLY CLEAR ACROSS MOST OF THE AREA...BUT WITH HEATING LATE THIS MORNING...EXPECT CU TO BEGIN TO DEVELOP FAIRLY RAPIDLY...FIRST ALONG THE BUFFALO RIDGE AND THEN SPREADING TO MOST AREAS ALONG AND EAST OF I29. BASED UPON NAM SOUNDINGS...VIRTUALLY NO CAP WILL EXIST OVER PORTIONS OF SW MN AND NW IA WITH ONLY A WEAK CAPPING INVERSION AROUND KFSD. THE HRRR DOES SHOW SCATTERED CONVECTION FORMING DURING THE AFTERNOON IN SW MN AND NW IA. A STRONGER CAP...AROUND 50 J/KG...EXISTS FARTHER WEST IN THE JAMES AND MISSOURI VALLEYS AND SHOULD PREVENT ANY CONVECTION TODAY. THEREFORE EXPECT A FEW THUNDERSTORMS TO DEVELOP DURING THE AFTERNOON AND PERSIST INTO THE EVENING. BELIEVE CONVECTION WILL FAVOR THE BUFFALO RIDGE AREA BUT ISOLATED STORMS ARE POSSIBLE ALMOST ANYWHERE ALONG AND EAST OF 29 AND HAVE INCLUDED SIOUX FALLS AND MOST OF NW IA IN AREA FOR ISOLATED CONVECTION. THERE IS ENOUGH INSTABILITY...CAPES BETWEEN 1000 AND 1500 J/KG TO SUPPORT AT LEAST SMALL HAIL ALTHOUGH...AS MENTIONED IN THE PREVIOUS DISCUSSION...WITH EFFECTIVE SHEAR AROUND 20 KTS...STORMS WILL NOT BE ORGANIZED. IN ADDITION...SFC TO 3 KM THETA-E DIFFERENCE WILL EXCEED 20 K. THE FLOW AROUND 3 KM IS ONLY 10 TO 15 KTS SO NOT A LOT OF MOMENTUM TO BRING DOWN BUT WITH THE POSSIBLE ACCELERATION OF AIR PARCELS IN THE DOWNDRAFT...A FEW GUSTS TO 30 OR 40 MPH ARE POSSIBLE AS STORMS COLLAPSE. IN ADDITION...WITH LIGHT SYNOPTIC SCALE WINDS...OUTFLOW BOUNDARIES ARE LIKELY TO SPREAD OUT FROM CONVECTION AND MAY INCREASE WIND SPEEDS TEMPORARILY MILES FROM ANY ACTUAL RAIN. UPDATED GRIDS SENT. WILL BE UPDATING HWO TO ADD THREAT OF SMALL HAIL AND STRONGER WIND GUSTS TO TODAY. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 345 AM CDT SUN AUG 3 2014 LAST OF THE OVERNIGHT CONVECTION IS PULLING OUT OF OUR CWA VERY EARLY THIS MORNING AS THE ASSOCIATED SHORTWAVE DROPS INTO SOUTHERN IOWA. WITH THE DEPARTURE OF THIS CONVECTION THINK THAT MUCH OF THE REMAINDER OF THE MORNING AND AFTERNOON WILL BE DRY IN THE ABSENCE OF ANY SIGNIFICANT FORCING...UNTIL LATER AFTERNOON WHEN A WEAK BOUNDARY BEGINS TO DROP OUT OF NORTHERN SOUTH DAKOTA. AS ANOTHER SHORTWAVE FALLS SOUTHWARD THROUGH WESTERN MINNESOTA ON A NORTHWESTERLY UPPER LEVEL FLOW...MAY GET ENOUGH INTERACTION WITH THE FRONT TO AGAIN KICK OFF ISOLATED CONVECTION IN OUR EAST IN THE LATE AFTERNOON AND EVENING...THOUGH MODELS WOULD SUGGEST THAT THE BETTER ACTIVITY WILL REMAIN TO THE EAST OF OUR CWA. WHILE MODERATE INSTABILITY WILL EXIST IN THE VICINITY OF THE BOUNDARY...EFFECTIVE SHEAR REMAINS WEAK...SO WOULD NOT EXPECT ANY REAL ORGANIZATION TO ANY STORMS THAT DEVELOP AND THINKING THAT ANY SEVERE THREAT IS MINIMAL. AS FOR TEMPERATURES TODAY...850 MB THERMAL PROFILES ARE SIMILAR TO YESTERDAY AND LOOKING AT HIGHS ONCE AGAIN IN THE 80S...CLOSING IN ON 90 THROUGH SOUTH CENTRAL SOUTH DAKOTA. BY TONIGHT ANY ISOLATED CONVECTION THAT DEVELOPS IN OUR EAST WILL TREND DOWNWARD THROUGH THE LATER EVENING/EARLY NIGHT TIME HOURS AS THE ASSOCIATED SHORTWAVE PULLS AWAY FROM THE AREA. IT WILL BE ANOTHER MILD NIGHT WITH LOWS IN THE LOWER 60S. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 345 AM CDT SUN AUG 3 2014 SUBTLE UPPER WAVE SLIDES SOUTHEAST ACROSS NORTHEAST PORTIONS OF THE AREA MONDAY. WITH THIS REGION NEAR AXIS OF LOW LEVEL RIDGE...WILL LIKELY SEE FAIRLY HIGH CLOUD BASES. HOWEVER THESE WEAK WAVES HAVE BEEN ABLE TO TRIGGER SPOTTY ACTIVITY RECENTLY AND SEE NO REASON WHY MONDAY SHOULD BE ANY DIFFERENT. MID LEVEL INSTABILITY IS NOT OVERLY IMPRESSIVE...SO WOULD NOT EXPECT ANY SEVERE STORMS TO DEVELOP. ATTENTION THEN TURNS TO MORE SIGNIFICANT SYSTEM SET TO AFFECT THE REGION. FIRST EXPECT ISOLATED TO SCATTERED ELEVATED ACTIVITY MONDAY NIGHT/TUESDAY WITH THE INITIAL SURGE OF WARM ADVECTION. THIS WILL BE FOLLOWED TUESDAY NIGHT/WEDNESDAY BY FIRST REAL POTENTIAL FOR MORE WIDESPREAD...POSSIBLY HEAVY...PRECIPITATION THAT THE REGION HAS SEEN IN QUITE A WHILE. SEEING SOME DISAGREEMENT IN THE MODELS REGARDING NORTH-SOUTH PLACEMENT OF THEIR RESPECTIVE PRECIPITATION OUTPUT...BUT LARGE SCALE FORCING FROM DEEP WARM ADVECTION/ISENTROPIC LIFT/THETA-E ADVECTION SEEM TO SHOW BETTER CONSENSUS...WHICH CURRENTLY POINTS TO BETTER CHANCES BETWEEN MISSOURI VALLEY AND I-90 CORRIDOR. THIS LENDS SOME CONFIDENCE IN BUMPING POPS IN THESE AREAS UP INTO CATEGORICAL RANGE FOR TUESDAY NIGHT...THOUGH AT THIS TIME LOOKS LIKE FAIRLY GOOD POTENTIAL FOR AT LEAST MEASURABLE PRECIP OVER MOST OF THE FORECAST AREA. SYSTEM WILL GRADUALLY PULL AWAY FROM THE REGION ON WEDNESDAY...AFTER WHICH TIME MODEL CONSENSUS DIMINISHES AS WELL. MODELS DO GENERALLY AGREE THAT LONGER RANGE...WEDNESDAY THROUGH SATURDAY...WILL START OFF ON THE COOL SIDE WITH HIGHS LARGELY BACK IN THE 70S WEDNESDAY AND THURSDAY. MORE PROGRESSIVE GFS THEN A LITTLE FASTER IN EXPANDING WARMER AIR BACK INTO THE REGION...ACCOMPANIED BY FAIRLY WET PATTERN FOR FRIDAY/SATURDAY. MEANWHILE ECMWF/GEM HOLD ONTO COOLER LOW LEVEL FLOW...WHILE KEEPING THINGS DRY WITH RIDGING ALOFT. GIVEN THESE DISCREPANCIES...HAVE NOT STRAYED FAR FROM BROAD CONSENSUS GRIDS FOR THE LATTER PART OF THE FORECAST PERIOD...SHOWING A SLOW WARMING TREND WITH LOW PRECIP CHANCES EACH DAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1244 PM CDT SUN AUG 3 2014 SMALL CHANCES FOR THUNDERSTORMS THROUGH 18Z MONDAY ARE THE MAIN CONCERN. WHILE THERE IS NO STRONG SYSTEM TO ORGANIZE CONVECTION A WEAK WAVE THIS AFTERNOON AND ANOTHER LATE TONIGHT AND MONDAY MORNING WILL BRING SMALL CHANCES OF THUNDERSTORMS. IN THE CASE OF THIS AFTERNOON...THIS CHANCE WILL BE PRIMARILY EAST OF I-29 ALTHOUGH A STORM COULD OCCUR AS FAR WEST AS KFSD. LATE TONIGHT AND MONDAY MORNING...THERE WILL BE A LOW PROBABILITY OF STORMS BEGINNING AROUND KHON AND SPREADING SOUTHEAST TOWARD KFSD AND KSUX ON MONDAY MORNING. BUT WITH LOW PROBABILITIES FOR CONVECTION AT ANY TIME FOR TAF LOCATIONS...DID NOT INCLUDE IN FORECAST. OTHERWISE LIGHT WINDS AND VFR CONDITIONS EXPECTED THROUGH 18Z MONDAY. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ UPDATE...SCHUMACHER SHORT TERM...JM LONG TERM...JH AVIATION...SCHUMACHER
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1120 AM MDT SUN AUG 3 2014 .UPDATE... ISSUED AT 856 AM MDT SUN AUG 3 2014 A WEAK WAVE CONTINUES TO MOVE THROUGH THE WESTERN DAKOTAS...PRODUCING SOME LIGHT SHOWERS ACROSS NORTHEASTERN WYOMING AND FAR WESTERN SOUTH DAKOTA. WINDS ACROSS THE AREA ARE LIGHT AND VARIABLE...AND TEMPS ARE IN THE UPPER 60S AND LOWER 70S. UPDATED GRIDS TO INCREASE POPS SLIGHTLY AND TWEAK SKY GRIDS. REST OF FORECAST LOOKS FINE AT THIS TIME. && .SHORT TERM...TODAY THROUGH MONDAY NIGHT ISSUED AT 259 AM MDT SUN AUG 3 2014 UPPER RIDGING CONTINUES ACROSS THE WESTERN CONUS WITH NW FLOW CROSSING THE NRN PLAINS. WEAK UPPER WAVES CONTINUE TO ROUND THE TOP OF THE RIDGE OVER THE NRN ROCKIES INTO THE NRN HIGH PLAINS. WV IMAGERY SHOWS AN UPPER WAVE NOW CROSSING ERN MT BRINGING SHOWERS TO SE MT. HRRR SHOWS THESE SHOWERS MAKING INTO FAR NE WY THRU NW SD BEFORE 18Z SO HAVE ADDED SL CHC POPS THERE. MLCAPE FORECAST TO BE 500-1000 J/KG AGAIN TODAY...BUT BETTER LL SHEAR DEVELOPS LATE AFTN/EVNG AS SFC LOW DEVELOPS JUST NW OF THE CWA. COULD SEE ISOLATED STRONG STORMS OR PERHAPS A SVR STORM OR TWO. WRN CONUS RIDGE BREAKS DOWN MONDAY AS UPPER LOW SLIDES INTO GREAT BASIN. MONSOONAL STORMS WILL DEVELOP ACROSS WY AND BLKHLS...THEN CROSS INTO THE CWA PLAINS THROUGH THE EVNG. MLCAPE OF 500-1000 AGAIN EXPECTED...BUT THIS TIME WITH WEAKER AVAILABLE SHEAR. SEVERE STORMS ARE NOT EXPECTED MON/MON NIGHT. && .LONG TERM...TUESDAY THROUGH SATURDAY ISSUED AT 259 AM MDT SUN AUG 3 2014 ACTIVE SW FLOW WILL DEVELOP BY TUESDAY...WITH DAILY CHANCE FOR SHRA/TS THROUGH MOST OF THE WEEK...AS THE NE PAC NEGATIVE HEIGHT ANOMALY SUPPORTS NUMEROUS LOW AMPLITUDE IMPULSES INTO THE FLOW AND THE WESTERN RIDGE BREAKS DOWN. MOST ACTIVITY IS EXPECTED TO A HAVE A STRONG DIURNAL COMPONENT...SUPPORTING THE HIGHEST CHANCES FOR PRECIP IN THE AFTERNOON PERIODS...AND ESP OVER THE BLACK HILLS GIVEN OROGRAPHIC INFLUENCES. GENERAL WSW FLOW WILL PERSIST INTO THE WEEKEND WITH NO NOTED HIGH LATITUDE BLOCKING FAVORED IN MEAN MODEL AND ENSEMBLE SOLUTIONS UNTIL EARLY NEXT WEEK WHEN THE EASTERN NOAM UPPER TROUGH MAY MAKE A RETURN. CARRIED AT LEAST A SLIGHT CHANCE POP MENTION THROUGH THE PERIOD...RETAINING HIGHER NUMBERS TUESDAY THROUGH WED GIVEN CONSISTENT SIGNALS FOR ADVECTING IMPULSES WITH APPRECIABLE LL MOISTURE/WEAK CAPPING/AND A STALLED FRONTAL BOUNDARY OVER THE REGION. RETAINED HIGHEST NUMBERS OVER THE BLACK HILLS...ESP TUE AND WED. GENERAL WEAK 0-8 KM FLOW WITH PW VALUES IN EXCESS OF 1 INCH MOST PLACES WILL SUPPORT AN INCREASED CHANCE FOR HEAVY RAINFALL...ESP IN THE NORTHERN BLACK HILLS. SOME STRONG TO SEVERE STORMS CANNOT BE RULED OUT IN THE PERIOD GIVEN POTENTIAL INCREASE IN MID LEVEL FLOW AND POTENTIAL LL MOISTURE...ESP EARLY IN THE PERIOD. TEMPERATURES ARE EXPECTED TO BE ON THE COOL SIDE OF SEASONAL NORMS THROUGH MOST OF THE WEEK. LL EASTERLY FLOW/INCREASED CHANCES FOR RAIN/AND INCREASED CLOUD COVER ARE ALL EXPECTED TO SUPPORT COOLER TEMPS. HAVE CONTINUED TO NUDGE TEMPS DOWN TUES GIVEN MODEL/MOS TRENDS. WARMER WEATHER LOOKS TO RETURN BY THE END OF THE WEEK AS BL DRYING OCCURS UNDER HEIGHT RISES AND THERMAL RIDGING. && .AVIATION...FOR THE 18Z TAFS THROUGH 18Z MONDAY ISSUED AT 1120 AM MDT SUN AUG 3 2014 VFR CONDITIONS EXPECTED THROUGH THE PERIOD FOR MOST PLACES. ISOLD TSRA WITH SCT -SHRA POSSIBLE THIS AFTERNOON/EVENING...ESPECIALLY OVER THE BLKHLS. LCL MVFR VSBY AND GUSTY WINDS ARE POSSIBLE IN HEAVIER CELLS. ISOLD SHRA/TS WILL LINGER THROUGH TONIGHT ACROSS THE WESTERN HALF OF SD. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ UPDATE...POJORLIE SHORT TERM...13 LONG TERM...JC AVIATION...MLS
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
900 AM MDT SUN AUG 3 2014 .UPDATE... ISSUED AT 856 AM MDT SUN AUG 3 2014 A WEAK WAVE CONTINUES TO MOVE THROUGH THE WESTERN DAKOTAS...PRODUCING SOME LIGHT SHOWERS ACROSS NORTHEASTERN WYOMING AND FAR WESTERN SOUTH DAKOTA. WINDS ACROSS THE AREA ARE LIGHT AND VARIABLE...AND TEMPS ARE IN THE UPPER 60S AND LOWER 70S. UPDATED GRIDS TO INCREASE POPS SLIGHTLY AND TWEAK SKY GRIDS. REST OF FORECAST LOOKS FINE AT THIS TIME. && .SHORT TERM...TODAY THROUGH MONDAY NIGHT ISSUED AT 259 AM MDT SUN AUG 3 2014 UPPER RIDGING CONTINUES ACROSS THE WESTERN CONUS WITH NW FLOW CROSSING THE NRN PLAINS. WEAK UPPER WAVES CONTINUE TO ROUND THE TOP OF THE RIDGE OVER THE NRN ROCKIES INTO THE NRN HIGH PLAINS. WV IMAGERY SHOWS AN UPPER WAVE NOW CROSSING ERN MT BRINGING SHOWERS TO SE MT. HRRR SHOWS THESE SHOWERS MAKING INTO FAR NE WY THRU NW SD BEFORE 18Z SO HAVE ADDED SL CHC POPS THERE. MLCAPE FORECAST TO BE 500-1000 J/KG AGAIN TODAY...BUT BETTER LL SHEAR DEVELOPS LATE AFTN/EVNG AS SFC LOW DEVELOPS JUST NW OF THE CWA. COULD SEE ISOLATED STRONG STORMS OR PERHAPS A SVR STORM OR TWO. WRN CONUS RIDGE BREAKS DOWN MONDAY AS UPPER LOW SLIDES INTO GREAT BASIN. MONSOONAL STORMS WILL DEVELOP ACROSS WY AND BLKHLS...THEN CROSS INTO THE CWA PLAINS THROUGH THE EVNG. MLCAPE OF 500-1000 AGAIN EXPECTED...BUT THIS TIME WITH WEAKER AVAILABLE SHEAR. SEVERE STORMS ARE NOT EXPECTED MON/MON NIGHT. && .LONG TERM...TUESDAY THROUGH SATURDAY ISSUED AT 259 AM MDT SUN AUG 3 2014 ACTIVE SW FLOW WILL DEVELOP BY TUESDAY...WITH DAILY CHANCE FOR SHRA/TS THROUGH MOST OF THE WEEK...AS THE NE PAC NEGATIVE HEIGHT ANOMALY SUPPORTS NUMEROUS LOW AMPLITUDE IMPULSES INTO THE FLOW AND THE WESTERN RIDGE BREAKS DOWN. MOST ACTIVITY IS EXPECTED TO A HAVE A STRONG DIURNAL COMPONENT...SUPPORTING THE HIGHEST CHANCES FOR PRECIP IN THE AFTERNOON PERIODS...AND ESP OVER THE BLACK HILLS GIVEN OROGRAPHIC INFLUENCES. GENERAL WSW FLOW WILL PERSIST INTO THE WEEKEND WITH NO NOTED HIGH LATITUDE BLOCKING FAVORED IN MEAN MODEL AND ENSEMBLE SOLUTIONS UNTIL EARLY NEXT WEEK WHEN THE EASTERN NOAM UPPER TROUGH MAY MAKE A RETURN. CARRIED AT LEAST A SLIGHT CHANCE POP MENTION THROUGH THE PERIOD...RETAINING HIGHER NUMBERS TUESDAY THROUGH WED GIVEN CONSISTENT SIGNALS FOR ADVECTING IMPULSES WITH APPRECIABLE LL MOISTURE/WEAK CAPPING/AND A STALLED FRONTAL BOUNDARY OVER THE REGION. RETAINED HIGHEST NUMBERS OVER THE BLACK HILLS...ESP TUE AND WED. GENERAL WEAK 0-8 KM FLOW WITH PW VALUES IN EXCESS OF 1 INCH MOST PLACES WILL SUPPORT AN INCREASED CHANCE FOR HEAVY RAINFALL...ESP IN THE NORTHERN BLACK HILLS. SOME STRONG TO SEVERE STORMS CANNOT BE RULED OUT IN THE PERIOD GIVEN POTENTIAL INCREASE IN MID LEVEL FLOW AND POTENTIAL LL MOISTURE...ESP EARLY IN THE PERIOD. TEMPERATURES ARE EXPECTED TO BE ON THE COOL SIDE OF SEASONAL NORMS THROUGH MOST OF THE WEEK. LL EASTERLY FLOW/INCREASED CHANCES FOR RAIN/AND INCREASED CLOUD COVER ARE ALL EXPECTED TO SUPPORT COOLER TEMPS. HAVE CONTINUED TO NUDGE TEMPS DOWN TUES GIVEN MODEL/MOS TRENDS. WARMER WEATHER LOOKS TO RETURN BY THE END OF THE WEEK AS BL DRYING OCCURS UNDER HEIGHT RISES AND THERMAL RIDGING. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 517 AM MDT SUN AUG 3 2014 VFR CONDITIONS EXPECTED THROUGH THE PERIOD MOST PLACES. ISOLD SHRA WILL BE POSSIBLE ACROSS THE WESTERN HALF THIS MORNING...WITH SCT- ISOLATED SHRA/TSTMS EXPECTED TO DEVELOP THIS AFTN...ESPECIALLY OVER THE BLKHLS. LCL MVFR VSBY AND GUSTY WINDS ARE POSSIBLE IN HEAVIER CELLS THIS AFTERNOON. ISOLD SHRA/TS WILL LINGER THROUGH TONIGHT...ESP ACROSS NW SD. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ UPDATE...POJORLIE SHORT TERM...13 LONG TERM...JC AVIATION...JC
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
956 AM CDT SUN AUG 3 2014 .UPDATE... ISSUED AT 956 AM CDT SUN AUG 3 2014 HAVE MADE MINOR ADJUSTMENTS TO THE FORECAST. VIS AND WATER VAPOR IMAGERY SHOWS TWO WAVE MOVES IN THE NORTHERN PLAINS. THE FIRST IS IN THE RED RIVER VALLEY WITH SOME CONVECTION ASSOCIATED WITH IT. A STRONGER WAVE WAS JUST MOVING INTO THE WESTERN DAKOTAS. SKIES ARE CURRENTLY CLEAR ACROSS MOST OF THE AREA...BUT WITH HEATING LATE THIS MORNING...EXPECT CU TO BEGIN TO DEVELOP FAIRLY RAPIDLY...FIRST ALONG THE BUFFALO RIDGE AND THEN SPREADING TO MOST AREAS ALONG AND EAST OF I29. BASED UPON NAM SOUNDINGS...VIRTUALLY NO CAP WILL EXIST OVER PORTIONS OF SW MN AND NW IA WITH ONLY A WEAK CAPPING INVERSION AROUND KFSD. THE HRRR DOES SHOW SCATTERED CONVECTION FORMING DURING THE AFTERNOON IN SW MN AND NW IA. A STRONGER CAP...AROUND 50 J/KG...EXISTS FARTHER WEST IN THE JAMES AND MISSOURI VALLEYS AND SHOULD PREVENT ANY CONVECTION TODAY. THEREFORE EXPECT A FEW THUNDERSTORMS TO DEVELOP DURING THE AFTERNOON AND PERSIST INTO THE EVENING. BELIEVE CONVECTION WILL FAVOR THE BUFFALO RIDGE AREA BUT ISOLATED STORMS ARE POSSIBLE ALMOST ANYWHERE ALONG AND EAST OF 29 AND HAVE INCLUDED SIOUX FALLS AND MOST OF NW IA IN AREA FOR ISOLATED CONVECTION. THERE IS ENOUGH INSTABILITY...CAPES BETWEEN 1000 AND 1500 J/KG TO SUPPORT AT LEAST SMALL HAIL ALTHOUGH...AS MENTIONED IN THE PREVIOUS DISCUSSION...WITH EFFECTIVE SHEAR AROUND 20 KTS...STORMS WILL NOT BE ORGANIZED. IN ADDITION...SFC TO 3 KM THETA-E DIFFERENCE WILL EXCEED 20 K. THE FLOW AROUND 3 KM IS ONLY 10 TO 15 KTS SO NOT A LOT OF MOMENTUM TO BRING DOWN BUT WITH THE POSSIBLE ACCELERATION OF AIR PARCELS IN THE DOWNDRAFT...A FEW GUSTS TO 30 OR 40 MPH ARE POSSIBLE AS STORMS COLLAPSE. IN ADDITION...WITH LIGHT SYNOPTIC SCALE WINDS...OUTFLOW BOUNDARIES ARE LIKELY TO SPREAD OUT FROM CONVECTION AND MAY INCREASE WIND SPEEDS TEMPORARILY MILES FROM ANY ACTUAL RAIN. UPDATED GRIDS SENT. WILL BE UPDATING HWO TO ADD THREAT OF SMALL HAIL AND STRONGER WIND GUSTS TO TODAY. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 345 AM CDT SUN AUG 3 2014 LAST OF THE OVERNIGHT CONVECTION IS PULLING OUT OF OUR CWA VERY EARLY THIS MORNING AS THE ASSOCIATED SHORTWAVE DROPS INTO SOUTHERN IOWA. WITH THE DEPARTURE OF THIS CONVECTION THINK THAT MUCH OF THE REMAINDER OF THE MORNING AND AFTERNOON WILL BE DRY IN THE ABSENCE OF ANY SIGNIFICANT FORCING...UNTIL LATER AFTERNOON WHEN A WEAK BOUNDARY BEGINS TO DROP OUT OF NORTHERN SOUTH DAKOTA. AS ANOTHER SHORTWAVE FALLS SOUTHWARD THROUGH WESTERN MINNESOTA ON A NORTHWESTERLY UPPER LEVEL FLOW...MAY GET ENOUGH INTERACTION WITH THE FRONT TO AGAIN KICK OFF ISOLATED CONVECTION IN OUR EAST IN THE LATE AFTERNOON AND EVENING...THOUGH MODELS WOULD SUGGEST THAT THE BETTER ACTIVITY WILL REMAIN TO THE EAST OF OUR CWA. WHILE MODERATE INSTABILITY WILL EXIST IN THE VICINITY OF THE BOUNDARY...EFFECTIVE SHEAR REMAINS WEAK...SO WOULD NOT EXPECT ANY REAL ORGANIZATION TO ANY STORMS THAT DEVELOP AND THINKING THAT ANY SEVERE THREAT IS MINIMAL. AS FOR TEMPERATURES TODAY...850 MB THERMAL PROFILES ARE SIMILAR TO YESTERDAY AND LOOKING AT HIGHS ONCE AGAIN IN THE 80S...CLOSING IN ON 90 THROUGH SOUTH CENTRAL SOUTH DAKOTA. BY TONIGHT ANY ISOLATED CONVECTION THAT DEVELOPS IN OUR EAST WILL TREND DOWNWARD THROUGH THE LATER EVENING/EARLY NIGHT TIME HOURS AS THE ASSOCIATED SHORTWAVE PULLS AWAY FROM THE AREA. IT WILL BE ANOTHER MILD NIGHT WITH LOWS IN THE LOWER 60S. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 345 AM CDT SUN AUG 3 2014 SUBTLE UPPER WAVE SLIDES SOUTHEAST ACROSS NORTHEAST PORTIONS OF THE AREA MONDAY. WITH THIS REGION NEAR AXIS OF LOW LEVEL RIDGE...WILL LIKELY SEE FAIRLY HIGH CLOUD BASES. HOWEVER THESE WEAK WAVES HAVE BEEN ABLE TO TRIGGER SPOTTY ACTIVITY RECENTLY AND SEE NO REASON WHY MONDAY SHOULD BE ANY DIFFERENT. MID LEVEL INSTABILITY IS NOT OVERLY IMPRESSIVE...SO WOULD NOT EXPECT ANY SEVERE STORMS TO DEVELOP. ATTENTION THEN TURNS TO MORE SIGNIFICANT SYSTEM SET TO AFFECT THE REGION. FIRST EXPECT ISOLATED TO SCATTERED ELEVATED ACTIVITY MONDAY NIGHT/TUESDAY WITH THE INITIAL SURGE OF WARM ADVECTION. THIS WILL BE FOLLOWED TUESDAY NIGHT/WEDNESDAY BY FIRST REAL POTENTIAL FOR MORE WIDESPREAD...POSSIBLY HEAVY...PRECIPITATION THAT THE REGION HAS SEEN IN QUITE A WHILE. SEEING SOME DISAGREEMENT IN THE MODELS REGARDING NORTH-SOUTH PLACEMENT OF THEIR RESPECTIVE PRECIPITATION OUTPUT...BUT LARGE SCALE FORCING FROM DEEP WARM ADVECTION/ISENTROPIC LIFT/THETA-E ADVECTION SEEM TO SHOW BETTER CONSENSUS...WHICH CURRENTLY POINTS TO BETTER CHANCES BETWEEN MISSOURI VALLEY AND I-90 CORRIDOR. THIS LENDS SOME CONFIDENCE IN BUMPING POPS IN THESE AREAS UP INTO CATEGORICAL RANGE FOR TUESDAY NIGHT...THOUGH AT THIS TIME LOOKS LIKE FAIRLY GOOD POTENTIAL FOR AT LEAST MEASURABLE PRECIP OVER MOST OF THE FORECAST AREA. SYSTEM WILL GRADUALLY PULL AWAY FROM THE REGION ON WEDNESDAY...AFTER WHICH TIME MODEL CONSENSUS DIMINISHES AS WELL. MODELS DO GENERALLY AGREE THAT LONGER RANGE...WEDNESDAY THROUGH SATURDAY...WILL START OFF ON THE COOL SIDE WITH HIGHS LARGELY BACK IN THE 70S WEDNESDAY AND THURSDAY. MORE PROGRESSIVE GFS THEN A LITTLE FASTER IN EXPANDING WARMER AIR BACK INTO THE REGION...ACCOMPANIED BY FAIRLY WET PATTERN FOR FRIDAY/SATURDAY. MEANWHILE ECMWF/GEM HOLD ONTO COOLER LOW LEVEL FLOW...WHILE KEEPING THINGS DRY WITH RIDGING ALOFT. GIVEN THESE DISCREPANCIES...HAVE NOT STRAYED FAR FROM BROAD CONSENSUS GRIDS FOR THE LATTER PART OF THE FORECAST PERIOD...SHOWING A SLOW WARMING TREND WITH LOW PRECIP CHANCES EACH DAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 604 AM CDT SUN AUG 3 2014 PATCHY MVFR VISIBILITIES EARLY THIS MORNING...OTHERWISE EXPECTING VFR CONDITIONS THROUGH THE TAF PERIOD. MAY SEE ISOLATED THUNDERSTORMS DEVELOP GENERALLY EAST OF INTERSTATE 29 THIS AFTERNOON AND EVENING...THOUGH NOT EXPECTED TO AFFECT TAF SITES. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ UPDATE...SCHUMACHER SHORT TERM...JM LONG TERM...JH AVIATION...JM
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
520 AM MDT SUN AUG 3 2014 .SHORT TERM...TODAY THROUGH MONDAY NIGHT ISSUED AT 259 AM MDT SUN AUG 3 2014 UPPER RIDGING CONTINUES ACROSS THE WESTERN CONUS WITH NW FLOW CROSSING THE NRN PLAINS. WEAK UPPER WAVES CONTINUE TO ROUND THE TOP OF THE RIDGE OVER THE NRN ROCKIES INTO THE NRN HIGH PLAINS. WV IMAGERY SHOWS AN UPPER WAVE NOW CROSSING ERN MT BRINGING SHOWERS TO SE MT. HRRR SHOWS THESE SHOWERS MAKING INTO FAR NE WY THRU NW SD BEFORE 18Z SO HAVE ADDED SL CHC POPS THERE. MLCAPE FORECAST TO BE 500-1000 J/KG AGAIN TODAY...BUT BETTER LL SHEAR DEVELOPS LATE AFTN/EVNG AS SFC LOW DEVELOPS JUST NW OF THE CWA. COULD SEE ISOLATED STRONG STORMS OR PERHAPS A SVR STORM OR TWO. WRN CONUS RIDGE BREAKS DOWN MONDAY AS UPPER LOW SLIDES INTO GREAT BASIN. MONSOONAL STORMS WILL DEVELOP ACROSS WY AND BLKHLS...THEN CROSS INTO THE CWA PLAINS THROUGH THE EVNG. MLCAPE OF 500-1000 AGAIN EXPECTED...BUT THIS TIME WITH WEAKER AVAILABLE SHEAR. SEVERE STORMS ARE NOT EXPECTED MON/MON NIGHT. && .LONG TERM...TUESDAY THROUGH SATURDAY ISSUED AT 259 AM MDT SUN AUG 3 2014 ACTIVE SW FLOW WILL DEVELOP BY TUESDAY...WITH DAILY CHANCE FOR SHRA/TS THROUGH MOST OF THE WEEK...AS THE NE PAC NEGATIVE HEIGHT ANOMALY SUPPORTS NUMEROUS LOW AMPLITUDE IMPULSES INTO THE FLOW AND THE WESTERN RIDGE BREAKS DOWN. MOST ACTIVITY IS EXPECTED TO A HAVE A STRONG DIURNAL COMPONENT...SUPPORTING THE HIGHEST CHANCES FOR PRECIP IN THE AFTERNOON PERIODS...AND ESP OVER THE BLACK HILLS GIVEN OROGRAPHIC INFLUENCES. GENERAL WSW FLOW WILL PERSIST INTO THE WEEKEND WITH NO NOTED HIGH LATITUDE BLOCKING FAVORED IN MEAN MODEL AND ENSEMBLE SOLUTIONS UNTIL EARLY NEXT WEEK WHEN THE EASTERN NOAM UPPER TROUGH MAY MAKE A RETURN. CARRIED AT LEAST A SLIGHT CHANCE POP MENTION THROUGH THE PERIOD...RETAINING HIGHER NUMBERS TUESDAY THROUGH WED GIVEN CONSISTENT SIGNALS FOR ADVECTING IMPULSES WITH APPRECIABLE LL MOISTURE/WEAK CAPPING/AND A STALLED FRONTAL BOUNDARY OVER THE REGION. RETAINED HIGHEST NUMBERS OVER THE BLACK HILLS...ESP TUE AND WED. GENERAL WEAK 0-8 KM FLOW WITH PW VALUES IN EXCESS OF 1 INCH MOST PLACES WILL SUPPORT AN INCREASED CHANCE FOR HEAVY RAINFALL...ESP IN THE NORTHERN BLACK HILLS. SOME STRONG TO SEVERE STORMS CANNOT BE RULED OUT IN THE PERIOD GIVEN POTENTIAL INCREASE IN MID LEVEL FLOW AND POTENTIAL LL MOISTURE...ESP EARLY IN THE PERIOD. TEMPERATURES ARE EXPECTED TO BE ON THE COOL SIDE OF SEASONAL NORMS THROUGH MOST OF THE WEEK. LL EASTERLY FLOW/INCREASED CHANCES FOR RAIN/AND INCREASED CLOUD COVER ARE ALL EXPECTED TO SUPPORT COOLER TEMPS. HAVE CONTINUED TO NUDGE TEMPS DOWN TUES GIVEN MODEL/MOS TRENDS. WARMER WEATHER LOOKS TO RETURN BY THE END OF THE WEEK AS BL DRYING OCCURS UNDER HEIGHT RISES AND THERMAL RIDGING. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 517 AM MDT SUN AUG 3 2014 VFR CONDITIONS EXPECTED THROUGH THE PERIOD MOST PLACES. ISOLD SHRA WILL BE POSSIBLE ACROSS THE WESTERN HALF THIS MORNING...WITH SCT- ISOLATED SHRA/TSTMS EXPECTED TO DEVELOP THIS AFTN...ESPECIALLY OVER THE BLKHLS. LCL MVFR VSBY AND GUSTY WINDS ARE POSSIBLE IN HEAVIER CELLS THIS AFTERNOON. ISOLD SHRA/TS WILL LINGER THROUGH TONIGHT...ESP ACROSS NW SD. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ SHORT TERM...13 LONG TERM...JC AVIATION...JC
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
301 AM MDT SUN AUG 3 2014 .SHORT TERM...TODAY THROUGH MONDAY NIGHT ISSUED AT 259 AM MDT SUN AUG 3 2014 UPPER RIDGING CONTINUES ACROSS THE WESTERN CONUS WITH NW FLOW CROSSING THE NRN PLAINS. WEAK UPPER WAVES CONTINUE TO ROUND THE TOP OF THE RIDGE OVER THE NRN ROCKIES INTO THE NRN HIGH PLAINS. WV IMAGERY SHOWS AN UPPER WAVE NOW CROSSING ERN MT BRINGING SHOWERS TO SE MT. HRRR SHOWS THESE SHOWERS MAKING INTO FAR NE WY THRU NW SD BEFORE 18Z SO HAVE ADDED SL CHC POPS THERE. MLCAPE FORECAST TO BE 500-1000 J/KG AGAIN TODAY...BUT BETTER LL SHEAR DEVELOPS LATE AFTN/EVNG AS SFC LOW DEVELOPS JUST NW OF THE CWA. COULD SEE ISOLATED STRONG STORMS OR PERHAPS A SVR STORM OR TWO. WRN CONUS RIDGE BREAKS DOWN MONDAY AS UPPER LOW SLIDES INTO GREAT BASIN. MONSOONAL STORMS WILL DEVELOP ACROSS WY AND BLKHLS...THEN CROSS INTO THE CWA PLAINS THROUGH THE EVNG. MLCAPE OF 500-1000 AGAIN EXPECTED...BUT THIS TIME WITH WEAKER AVAILABLE SHEAR. SEVERE STORMS ARE NOT EXPECTED MON/MON NIGHT. && .LONG TERM...TUESDAY THROUGH SATURDAY ISSUED AT 259 AM MDT SUN AUG 3 2014 ACTIVE SW FLOW WILL DEVELOP BY TUESDAY...WITH DAILY CHANCE FOR SHRA/TS THROUGH MOST OF THE WEEK...AS THE NE PAC NEGATIVE HEIGHT ANOMALY SUPPORTS NUMEROUS LOW AMPLITUDE IMPULSES INTO THE FLOW AND THE WESTERN RIDGE BREAKS DOWN. MOST ACTIVITY IS EXPECTED TO A HAVE A STRONG DIURNAL COMPONENT...SUPPORTING THE HIGHEST CHANCES FOR PRECIP IN THE AFTERNOON PERIODS...AND ESP OVER THE BLACK HILLS GIVEN OROGRAPHIC INFLUENCES. GENERAL WSW FLOW WILL PERSIST INTO THE WEEKEND WITH NO NOTED HIGH LATITUDE BLOCKING FAVORED IN MEAN MODEL AND ENSEMBLE SOLUTIONS UNTIL EARLY NEXT WEEK WHEN THE EASTERN NOAM UPPER TROUGH MAY MAKE A RETURN. CARRIED AT LEAST A SLIGHT CHANCE POP MENTION THROUGH THE PERIOD...RETAINING HIGHER NUMBERS TUESDAY THROUGH WED GIVEN CONSISTENT SIGNALS FOR ADVECTING IMPULSES WITH APPRECIABLE LL MOISTURE/WEAK CAPPING/AND A STALLED FRONTAL BOUNDARY OVER THE REGION. RETAINED HIGHEST NUMBERS OVER THE BLACK HILLS...ESP TUE AND WED. GENERAL WEAK 0-8 KM FLOW WITH PW VALUES IN EXCESS OF 1 INCH MOST PLACES WILL SUPPORT AN INCREASED CHANCE FOR HEAVY RAINFALL...ESP IN THE NORTHERN BLACK HILLS. SOME STRONG TO SEVERE STORMS CANNOT BE RULED OUT IN THE PERIOD GIVEN POTENTIAL INCREASE IN MID LEVEL FLOW AND POTENTIAL LL MOISTURE...ESP EARLY IN THE PERIOD. TEMPERATURES ARE EXPECTED TO BE ON THE COOL SIDE OF SEASONAL NORMS THROUGH MOST OF THE WEEK. LL EASTERLY FLOW/INCREASED CHANCES FOR RAIN/AND INCREASED CLOUD COVER ARE ALL EXPECTED TO SUPPORT COOLER TEMPS. HAVE CONTINUED TO NUDGE TEMPS DOWN TUES GIVEN MODEL/MOS TRENDS. WARMER WEATHER LOOKS TO RETURN BY THE END OF THE WEEK AS BL DRYING OCCURS UNDER HEIGHT RISES AND THERMAL RIDGING. && .AVIATION...FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT ISSUED AT 259 AM MDT SUN AUG 3 2014 VFR CONDITIONS EXPECTED THROUGH MORNING. SCT-ISOLATED SHRA/TSTMS EXPECTED TO DEVELOP SUNDAY AFTN...ESPECIALLY OVER THE BLKHLS...WITH LCL MVFR VSBY. ISOLD SHRA/TS WILL LINGER THROUGH MUCH OF SUNDAY NIGHT...ESP ACROSS NW SD. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ SHORT TERM...13 LONG TERM...JC AVIATION...JC
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
147 PM CDT SUN AUG 3 2014 .UPDATE... CONVECTIVE TEMPS HAVE REMAINED IN THE MID 80S FOR MUCH OF THE DAY. THIS TEMPERATURE HAS BEEN REACHED AND WE ARE SEEING SOME CU DEVELOPMENT OVER THE LAST COUPLE OF HOURS. WILL GO AHEAD AND INCREASE THE CLOUD COVER TO PARTLY CLOUDY FOR THE REMAINDER OF TODAY. OTW...CAPE VALUES ARE QUITE LOW AND THE DEVELOPMENT OF CONVECTIVE PRECIP IS NOT EXPECTED. THE HRRR DOES ELUDE TOWARD A SHOWER OR TWO POPPING UP ACROSS SOUTH CENTRAL AREAS LATER THIS AFTERNOON. BUT COVERAGE SHOULD BE AT OR LESS THAN 10 PERCENT AND SHORT LIVED. && .PREV DISCUSSION... /ISSUED 1225 PM CDT SUN AUG 3 2014/ AVIATION 18Z DISCUSSION...NORTHWESTERLY FLOW WILL ALLOW DRIER AIRMASS TO REMAIN ACROSS THE TAF AREAS THROUGH THE NEXT 24 HOURS. THIS WILL KEEP CAPE VALUES AT A MINIMUM AND AS A RESULT...MOSTLY CLEAR SKIES AND DRY WEATHER IS EXPECTED TO CONTINUE. OTW...SOME LIGHT FOG MAY OCCUR AT CSV LATE TONIGHT. PREV DISCUSSION... /ISSUED 643 AM CDT SUN AUG 3 2014/ UPDATE...FOR 12Z AVIATION FORECASTS. AVIATION... AT CKV AND CSV...VFR THR0UGH 07Z/04, THEN BECOMING MVFR DUE TO BR. AT BNA...VFR CONDITIONS EXPECTED THROUGH THE FORECAST PERIOD. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 21
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AREA FORECAST DISCUSSION
NWS SEATTLE WA
1008 PM PDT SAT AUG 2 2014 .SYNOPSIS...A WEAK DISTURBANCE ALOFT WILL KEEP THE AIR MASS UNSTABLE ENOUGH FOR A RISK OF THUNDERSTORMS OVER MAINLY THE CASCADES THROUGH SUNDAY. HIGH PRESSURE ALOFT WILL PREVAIL OVER THE REGION MONDAY AND TUESDAY FOR DRY AND STABLE CONDITIONS. && .SHORT TERM... THERE WAS A SOUTHWEST TO NORTHEAST LINE OF TOWERING CUMULUS OVER THE PUGET SOUND REGION AT THIS TIME. SHOWERS WERE FALLING FROM THE FAR NORTH END OF THIS LINE IN SOUTHWEST SNOHOMISH COUNTY. INTERESTINGLY...THE RUC DID SHOW A BAND OF SHOWERS OVER THE PUGET SOUND REGION BUT EARLIER THAN OBSERVED. WILL UPDATE THE FORECAST TO ADD SHOWERS TO THE PUGET SOUND REGION FOR TONIGHT. CANNOT COMPLETELY RULE OUT TSTMS EITHER. THE SURFACE ONSHORE PRESSURE GRADIENT WAS TIGHTER THAN LAST NIGHT...HENCE STRATUS AND FOG HAS MADE IT AS FAR EAST AS THE LOWER CHEHALIS RIVER VALLEY. THERE ALSO APPEARED TO BE STRATUS AND/OR FOG OVER THE WATERS OF THE STRAIT OF JUAN DE FUCA. THE INTERIOR LOWLANDS SHOULD SHOULD SEE SOME STRATUS SUNDAY MORNING. IT LOOKS LIKE THE NAM MOS GUIDANCE PROBABLY HAS A BETTER HANDLE ON THE LOW CLOUDS. THE AIR MASS WILL BE GENERALLY STABLE ON SUNDAY WITH WEAK RIDGING OVER WESTERN WA. THUNDERSTORMS WILL BE LIMITED TO THE NORTH CASCADES ALONG THE CREST AS ANOTHER WEAK DISTURBANCE TRACKS ACROSS SOUTHERN BRITISH COLUMBIA. THE RIDGE WILL STRENGTHEN ON MONDAY FOR MORE DRY AND STABLE WEATHER. TEMPS WILL BE A FEW DEGREES WARMER WITH HIGHS IN THE MID 80S IN THE INTERIOR. ONSHORE FLOW WILL CONTINUE FOR COOLER AND CLOUDIER WEATHER ALONG THE COAST. THE RIDGE WILL START TO EXIT ON TUE BUT WE ARE STILL LOOKING FOR DRY AND WARM WEATHER. NO MAJOR CHANGES FROM THE PREVIOUS FORECAST. 33/05 .LONG TERM FROM THE PREV DISCUSSION... LONG TERM MODELS SHOWED THE UPPER LEVEL FLOW TURNING ZONAL BY MIDWEEK AS THE STRONG UPPER RIDGE SHIFTS TO THE MIDWEST. A WEAK FRONT WILL MOVE ACROSS WESTERN WA ON WEDNESDAY BUT THIS SYSTEM LOOKS DRY. HOWEVER...WILL SEE AN INCREASE IN LOW LEVEL ONSHORE FLOW THAT WILL LIKELY INCREASE THE COVERAGE OF MARINE STRATUS. THIS WILL ALSO KEEP TEMPS CLOSER TO NORMAL. THE PATTERN WILL REMAIN THE SAME THROUGH THE WEEKEND. WILL STICK WITH THE TREND OF MORNING LOW CLOUDS WITH AFTERNOON SUN BREAKS. ANOTHER RIDGE MAY BUILD OVER THE PAC NW EARLY NEXT WEEK FOR SLIGHTLY WARMER WEATHER. 33 && .AVIATION...FLOW ALOFT OVER WESTERN WASHINGTON IS SOUTHWESTERLY WITH AN UPPER RIDGE CENTERED OVER THE ROCKIES. AT THE SURFACE HIGH PRESSURE WILL REMAIN OFFSHORE WITH LOWER PRESSURE INLAND. IFR STRATUS ALONG THE COAST WILL SPREAD INLAND LATE TONIGHT BUT WILL LIKELY STOP AROUND THE WEST SHORES OF PUGET SOUND SUNDAY MORNING. SKIES ARE MOSTLY CLEAR AWAY FROM THE STRATUS. ISOLATED THUNDERSTORMS WILL CONTINUE OVER THE CASCADES THIS EVENING. KSEA...MOSTLY CLEAR. COASTAL STRATUS SPREADING INLAND SUNDAY MORNING IS EXPECTED TO STOP A LITTLE SHORT OF THE TERMINAL. NORTHWEST WIND 4-8 KNOTS BECOMING LIGHT SOUTHERLY AFTER MIDNIGHT. SCHNEIDER && .MARINE...HIGH PRESSURE WILL REMAIN OFFSHORE WITH LOWER PRESSURE INLAND FOR THE NEXT SEVERAL DAYS. SMALL CRAFT ADVISORY WEST WINDS ARE POSSIBLE EACH AFTERNOON AND EVENING IN THE STRAIT OF JUAN DE FUCA. AT THIS POINT MODELS POINT TO MONDAY EVENING AS HAVING THE STRONGEST ONSHORE GRADIENTS. GALES ARE POSSIBLE IN THE STRAIT MONDAY EVENING. SCHNEIDER && .SEW WATCHES/WARNINGS/ADVISORIES... WA...RED FLAG WARNING IN EFFECT TIL 11 PM TONIGHT FOR THE EAST PORTION OF THE NORTH CASCADES NATIONAL PARK/LAKE CHELAN NATIONAL RECREATIONAL AREA. PZ...SMALL CRAFT ADVISORY IN EFFECT FOR THE COASTAL WATERS FROM CAPE FLATTERY TO CAPE SHOALWATER FROM 10 NM TO OUT TO 60 NM AND CENTRAL/EASTERN STRAIT OF JUAN DE FUCA. && $$ WWW.WEATHER.GOV/SEATTLE FOR THE GRAPHICAL AFD...VISIT WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS SEATTLE WA
930 PM PDT SAT AUG 2 2014 .SYNOPSIS...A WEAK DISTURBANCE ALOFT WILL KEEP THE AIR MASS UNSTABLE ENOUGH FOR A RISK OF THUNDERSTORMS OVER MAINLY THE CASCADES THROUGH SUNDAY. HIGH PRESSURE ALOFT WILL PREVAIL OVER THE REGION MONDAY AND TUESDAY FOR DRY AND STABLE CONDITIONS. && .SHORT TERM... THERE WAS A SOUTHWEST TO NORTHEAST LINE OF TOWERING CUMULUS OVER THE PUGET SOUND REGION AT THIS TIME. SHOWERS WERE FALLING FROM THE FAR NORTH END OF THIS LINE IN SOUTHWEST SNOHOMISH COUNTY. INTERESTINGLY...THE RUC DID SHOW A BAND OF SHOWERS OVER THE PUGET SOUND REGION BUT EARLIER THAN OBSERVED. WILL UPDATE THE FORECAST TO ADD SHOWERS TO THE PUGET SOUND REGION FOR TONIGHT. CANNOT COMPLETELY RULE OUT TSTMS EITHER. THE SURFACE ONSHORE PRESSURE GRADIENT WAS TIGHTER THAN LAST NIGHT...HENCE STRATUS AND FOG HAS MADE IT AS FAR EAST AS THE LOWER CHEHALIS RIVER VALLEY. THERE ALSO APPEARED TO BE STRATUS AND/OR FOG OVER THE WATERS OF THE STRAIT OF JUAN DE FUCA. THE INTERIOR LOWLANDS SHOULD SHOULD SEE SOME STRATUS SUNDAY MORNING. IT LOOKS LIKE THE NAM MOS GUIDANCE PROBABLY HAS A BETTER HANDLE ON THE LOW CLOUDS. THE AIR MASS WILL BE GENERALLY STABLE ON SUNDAY WITH WEAK RIDGING OVER WESTERN WA. THUNDERSTORMS WILL BE LIMITED TO THE NORTH CASCADES ALONG THE CREST AS ANOTHER WEAK DISTURBANCE TRACKS ACROSS SOUTHERN BRITISH COLUMBIA. THE RIDGE WILL STRENGTHEN ON MONDAY FOR MORE DRY AND STABLE WEATHER. TEMPS WILL BE A FEW DEGREES WARMER WITH HIGHS IN THE MID 80S IN THE INTERIOR. ONSHORE FLOW WILL CONTINUE FOR COOLER AND CLOUDIER WEATHER ALONG THE COAST. THE RIDGE WILL START TO EXIT ON TUE BUT WE ARE STILL LOOKING FOR DRY AND WARM WEATHER. NO MAJOR CHANGES FROM THE PREVIOUS FORECAST. 33 .LONG TERM FROM THE PREV DISCUSSION... LONG TERM MODELS SHOWED THE UPPER LEVEL FLOW TURNING ZONAL BY MIDWEEK AS THE STRONG UPPER RIDGE SHIFTS TO THE MIDWEST. A WEAK FRONT WILL MOVE ACROSS WESTERN WA ON WEDNESDAY BUT THIS SYSTEM LOOKS DRY. HOWEVER...WILL SEE AN INCREASE IN LOW LEVEL ONSHORE FLOW THAT WILL LIKELY INCREASE THE COVERAGE OF MARINE STRATUS. THIS WILL ALSO KEEP TEMPS CLOSER TO NORMAL. THE PATTERN WILL REMAIN THE SAME THROUGH THE WEEKEND. WILL STICK WITH THE TREND OF MORNING LOW CLOUDS WITH AFTERNOON SUN BREAKS. ANOTHER RIDGE MAY BUILD OVER THE PAC NW EARLY NEXT WEEK FOR SLIGHTLY WARMER WEATHER. 33 && .AVIATION...FLOW ALOFT OVER WESTERN WASHINGTON IS SOUTHWESTERLY WITH AN UPPER RIDGE CENTERED OVER THE ROCKIES. AT THE SURFACE HIGH PRESSURE WILL REMAIN OFFSHORE WITH LOWER PRESSURE INLAND. IFR STRATUS ALONG THE COAST WILL SPREAD INLAND LATE TONIGHT BUT WILL LIKELY STOP AROUND THE WEST SHORES OF PUGET SOUND SUNDAY MORNING. SKIES ARE MOSTLY CLEAR AWAY FROM THE STRATUS. ISOLATED THUNDERSTORMS WILL CONTINUE OVER THE CASCADES THIS EVENING. KSEA...MOSTLY CLEAR. COASTAL STRATUS SPREADING INLAND SUNDAY MORNING IS EXPECTED TO STOP A LITTLE SHORT OF THE TERMINAL. NORTHWEST WIND 4-8 KNOTS BECOMING LIGHT SOUTHERLY AFTER MIDNIGHT. SCHNEIDER && .MARINE...HIGH PRESSURE WILL REMAIN OFFSHORE WITH LOWER PRESSURE INLAND FOR THE NEXT SEVERAL DAYS. SMALL CRAFT ADVISORY WEST WINDS ARE POSSIBLE EACH AFTERNOON AND EVENING IN THE STRAIT OF JUAN DE FUCA. AT THIS POINT MODELS POINT TO MONDAY EVENING AS HAVING THE STRONGEST ONSHORE GRADIENTS. GALES ARE POSSIBLE IN THE STRAIT MONDAY EVENING. SCHNEIDER && .SEW WATCHES/WARNINGS/ADVISORIES... WA...RED FLAG WARNING IN EFFECT TIL 11 PM TONIGHT FOR THE EAST PORTION OF THE NORTH CASCADES NATIONAL PARK/LAKE CHELAN NATIONAL RECREATIONAL AREA. PZ...SMALL CRAFT ADVISORY IN EFFECT FOR THE COASTAL WATERS FROM CAPE FLATTERY TO CAPE SHOALWATER FROM 10 NM TO OUT TO 60 NM AND CENTRAL/EASTERN STRAIT OF JUAN DE FUCA. && $$ WWW.WEATHER.GOV/SEATTLE FOR THE GRAPHICAL AFD...VISIT WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1113 AM CDT SUN AUG 3 2014 .UPDATE...SPS MESO PLOTS SHOW DESTABILIZATION ACROSS SRN WITH ML CAPE VALUES ALREADY TO AROUND 1000 J/KG. PRIMARY SHORTWAVE IS TRACKING FROM SE IA INTO WC IL. HOWEVER AN EXTENSION OF THIS VORT EXTENDS INTO SC WI. MESO MODELS CONTINUE TO SHOW A FAIR AMOUNT OF DEVELOPMENT THIS AFTERNOON...BUT A FORMIDABLE TRIGGER IS TOUGH TO LATCH ONTO. IN THE LOW LEVELS THERE REALLY IS NOTHING. BUT WE ARE EXPECTING THE LAKE BREEZE TO POSSIBLY SERVE AS A FOCUS. THERE JUST ISN/T MUCH GOING ON UPSTAIRS OUTSIDE OF THIS WEAK VORT AXIS. THE RAP SOUNDINGS APPEAR TO BE UNDERDOING THE CAPE WITH THE NAM SOUNDINGS MATCHING UP MORE WITH THE SPC MESO ANALYSIS. THE 12Z NAM AND 00Z ECMWF ARE BASICALLY DRY FOR THIS AFTERNOON. ALSO THE MAV/MET GUIDANCE HAS VERY LOW POPS FOR THIS AFTERNOON. AT THIS POINT WILL TREND POPS A SMIDGE LOWER AND GO WITH MORE ISOLD/SCT DEVELOPMENT. SHEAR AND MID LEVEL LAPSE RATES ARE NON-EXISTENT SO SVR POTENTIAL VERY LOW. ALSO 500 MILLIBAR TEMPS ARE -12C...SO NOT AS COLD AS YESTERDAY AND FRIDAY. PC && .AVIATION/18Z TAFS/...MAIN FOCUS IS ON COVERAGE OF CONVECTION THIS AFTERNOON. WEAK VORT AXIS EXPECTED TO MOVE THROUGH. STARTING TO SEE SOME CU POPPING. AIRMASS IS DESTABILIZING SO GOING WITH ISOLD/SCT DEVELOPMENT WITH SOME COOL AIR ALOFT AS WELL. WILL KEEP MUCH OF THIS FORECAST PERIOD VFR WITH PATCHY FOG POSSIBLE ONCE AGAIN LATER TONIGHT. FRONTAL BOUNDARY SAGS INTO SRN WI MONDAY WITH MORE NOTABLE SHORTWAVE ACTIVITY MOVING CLOSER FROM NRN WI AFFECTING THE AREA SO MAY SEE MORE COVERAGE ON THE STORMS FOR MON AFTN/EVE. PC && .PREV DISCUSSION... /ISSUED 338 AM CDT SUN AUG 3 2014/ TODAY AND TONIGHT...FORECAST CONFIDENCE MEDIUM. THE CORE OF THE SHORTWAVE TROUGH OVER IA WILL TRACK TO THE SOUTH BUT THE NORTHERN EXTENSION WILL SLOWLY MOVE ACROSS SRN WI THROUGH THE DAY. MLCAPE WILL RANGE FROM 500-1000 J/KG WITH LITTLE TO NO CAPPING. GIVEN THE TSTORM ACTIVITY THAT HAS OCCURRED FOR THE LAST SEVERAL DAYS...WOULD EXPECT SCT TSTORMS THIS AFTERNOON INTO THE EVENING WITH THE BEST FOCUS OVER THE NRN CWA AND ALONG THE LAKE BREEZE FRONT. ANOTHER SHORTWAVE TROUGH WILL APPROACH FROM THE NW LATE TNT ALONG WITH A WEAK COLD FRONT FROM THE NORTH...SO ISOLD TO SCT SHOWERS AND STORMS WILL REMAIN IN THE FORECAST. SMALL HAIL WILL LIKELY OCCUR WITH THE TSTORMS THIS AFTERNOON. HIGH TEMPS WILL BE SIMILAR TO YESTERDAY BUT WARMER NEAR THE LAKE AS THE LAKE BREEZE DEVELOPS LATER. MONDAY AND TUESDAY...FORECAST CONFIDENCE...MEDIUM A WEAK INVERTED SURFACE TROUGH IS EXPECTED TO KICK OFF MORE SHOWERS AND THUNDERSTORMS ON MONDAY. STORM MOTION WILL BE A LITTLE HIGHER THAN THE LAST FEW DAYS...UP AROUND 15 TO 20 KNOTS...SO THE STORMS SHOULD BE ABLE TO COVER A LITTLE MORE GROUND. BETWEEN THIS AND PLENTY OF INSTABILITY AND MOISTURE...DECIDED TO GO LIKELY POPS MOST PLACES. KEPT CHANCE POPS FOR MONDAY NIGHT AS A SHORTWAVE PUSHES THROUGH. WENT WITH ONLY SLIGHT CHANCE POPS TUESDAY...GOING DRY IN THE NORTHEAST AS A MUCH DRIER AIRMASS MOVES IN UNDER HIGH PRESSURE. SHOULD SEE TEMPS RIGHT AROUND NORMAL FOR MONDAY AND TUESDAY. WEDNESDAY THROUGH SATURDAY...FORECAST CONFIDENCE...MEDIUM MODELS SEEM TO BE FINALLY SETTLING ON A SOLUTION FOR THE SECOND HALF OF THE WEEK...BRINGING UPPER RIDGING AND SURFACE HIGH PRESSURE IN FOR MOST OF THIS PERIOD. KEPT A LITTLE POPS HERE AND THERE...THOUGH THESE WILL LIKELY NEED TO BE DROPPED IN THE FUTURE IF MODELS ARE PERSISTENT WITH FORECASTING THIS PATTERN. OTHERWISE...THIS SETUP SHOULD RESULT IN DRY WEATHER...WITH A GOOD AMOUNT OF SUNSHINE AND TEMPS NEAR TO A FEW DEGREES ABOVE NORMAL. AVIATION/12Z TAFS/...SCT-BKN050 WILL DEVELOP BY LATE MORNING AND LAST THROUGH THE REMAINDER OF THE DAY AND INTO MUCH OF SUN NT AS A COUPLE UPPER LEVEL DISTURBANCES AFFECT THE REGION. SCT TSTORMS ARE MAINLY EXPECTED THIS AFTERNOON WITH ISOLD TO SCT TSTORMS TNT. PATCHY FOG WILL OCCUR THROUGH SUNRISE THIS MORNING AND WILL AFFECT KMSN. OTHERWISE PATCHY FOG IS POSSIBLE AGAIN LATE SUN NT AND MAY AFFECT KMSN...KUES...KENW. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ TODAY/TONIGHT AND AVIATION/MARINE...GEHRING MONDAY THROUGH SATURDAY...DDV
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
640 PM MDT MON AUG 4 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY EVENING) ISSUED AT 230 PM MDT MON AUG 4 2014 CURRENTLY...WATER VAPOR IMAGERY SHOWING MONSOONAL MOISTURE MOVING INTO OUR WESTERN ZONES THIS AFTERNOON AS THE UPPER LOW THAT WAS OVER SOUTHERN CALIFORNIA YESTERDAY MOVES INTO CENTRAL UTAH. 12Z PWATS ON THE GJT SOUNDING OVER 1.2 INCHES. THIS MOISTURE IS HEADED OUR WAY. MOSAIC RADAR SHOWING FAIRLY WIDESPREAD LIGHT RAIN OVER CARBON COUNTY. A FEW THUNDERSTORMS DEVELOPING NEAR ARLINGTON AND CENTENNIAL WITH A FEW LIGHTNING STRIKES OBSERVED. BEGINNING TO SEE SOME CELLS DEVELOPING ON THE RADAR UP BY VEDAUWOO...SO SHOWERS HERE AT CHEYENNE ARE NOT THAT FAR OFF. FOR THIS AFTERNOON...LATEST HRRR FORECAST SHOWING CELLS DEVELOPING OVER THE LARAMIE RANGE AND DRIFTING EAST. ITS SHOWING A FAIRLY WIDESPREAD BAND OF SHOWERS AND THUNDERSTORMS MOVING SLOWLY EAST INTO THE PANHANDLE AROUND THE 23Z TIME FRAME. STORMS ARE GOING TO BE VERY SLOW MOVING...FROM THE SOUTHWEST AT UNDER 5KTS. THOSE AREAS THAT DO EXPERIENCE THUNDERSTORMS THIS AFTERNOON AND THIS EVENING COULD SEE CONSIDERABLE RAINFALL WITH THESE SLOW MOVING STORMS. UPPER SHORTWAVE MOVES BEST LIFT NORTH THIS EVENING...SO WE SHOULD SEE A LULL IN CONVECTION AFTER 03Z OR SO UNTIL TUESDAY. DRIED OUT THE SOUTHERN PANHANDLE AND SOUTHEAST WYOMING FROM LARAMIE TO WHEATLAND TO TORRINGTON THIS EVENING. NEXT PIECE OF ENERGY TO MOVE THROUGH THE AREA TUESDAY AFTERNOON AND EVENING AS THE UPPER LOW OPENS UP AND TRACKS INTO WESTERN WYOMING. NAM AND ECMWF SHOW GOOD QPF ACROSS MOST OF THE CWFA...CONCENTRATED ACROSS THE SOUTHERN PANHANDLE AND LARAMIE COUNTY TUESDAY AFTERNOON. STILL NOT MUCH IN THE STEERING FLOW...SO STORMS WILL ONCE AGAIN BE SLOW MOVING AND PRODUCING MODERATE TO HEAVY RAINFALL INTO TUESDAY EVENING. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 1222 PM MDT MON AUG 4 2014 WEDNESDAY...DESPITE A SHORTWAVE RIDGE ALOFT OVER OUR COUNTIES...WITH A LOW LEVEL CONVERGENCE BOUNDARY INDICATED FROM DOUGLAS TO CHEYENNE...ALONG WITH ADEQUATE LOW AND MID LEVEL MOISTURE AND DECENT UPWARD VERTICAL MOTION FROM DOUGLAS TO CHEYENNE...HAVE BOOSTED AFTERNOON AND EVENING POPS INTO THE 45 TO 70 PERCENT RANGE...WITH LESSER POPS ELSEWHERE. WITH WEAK STEERING WINDS...WILL LIKELY SEE A FEW HEAVY RAINERS AS WELL. THURSDAY...NEXT SHORTWAVE TROUGH ALOFT MOVES INTO WESTERN WYOMING AND UTAH...WHILE A LOW LEVEL CONVERGENCE AXIS SETS UP FROM NORTH CENTRAL COLORADO NORTHWARD TO NEAR TORRINGTON TO NEAR CHADRON. 850/700 MB THETA-E RIDGE AXIS...WELL PRONOUNCED...WILL EXTEND NORTH TO SOUTH IN THE AFTERNOON ACROSS FAR EASTERN WYOMING AND WESTERN NEBRASKA...AND WITH PROGGED INSTABILITIES...CAPE AND DECENT DIRECTIONAL SHEAR...EXPECT A FEW STRONG TO SEVERE THUNDERSTORMS EAST OF A LUSK TO CHEYENNE LINE...AND HAVE ALSO BOOSTED POPS EAST OF THIS LINE TO THE 50 TO 60 PERCENT RANGE WITH ALL CONVECTIVE AND MESOSCALE PARAMETERS COMING TOGETHER. FRIDAY...LESS LATE DAY COVERAGE OF SHOWERS AND THUNDERSTORMS EXPECTED WITH DECREASE IN LOW AND MID LEVEL MOISTURE...THOUGH WILL STILL SEE ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS IN THE AFTERNOON AND EVENING WITH MOIST UPSLOPE MECHANICAL LIFT. SATURDAY...SIMILAR SCENARIO TO FRIDAY...ALBEIT WITH SLIGHTLY LESS COVERAGE OF SHOWERS AND THUNDERSTORMS DUE TO LESS LOW AND MID LEVEL MOISTURE AVAILABILITY. SUNDAY...RIDGING ALOFT STRENGTHENS OVER OUR COUNTIES...THUS EXPECT SLIGHTLY LESS COVERAGE OF LATE DAY SHOWERS AND THUNDERSTORMS...FOCUSED ALMOST EXCLUSIVELY OVER THE MOUNTAINS AND HIGHER TERRAIN SUCH AS THE PINE RIDGE FROM NEAR LUSK TO NEAR CHADRON. MONDAY...EVEN MORE PRONOUNCED RIDGING ALOFT...AND WITH THE BULK OF THE MONSOONAL MOISTURE RESIDING OVER COLORADO...WILL ONLY FORECAST ISOLATED LATE DAY THUNDERSTORMS OVER AND NEAR THE SNOWY...SIERRA MADRE AND SOUTHERN LARAMIE RANGES...THOUGH WE WILL NEED TO WATCH FOR POSSIBLE GREATER INTRUSION OF MID LEVEL MONSOONAL MOISTURE AS IS TYPICAL FOR LATE JULY AND EARLY AUGUST. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY AFTERNOON) ISSUED AT 640 PM MDT MON AUG 4 2014 SHOWERS AND THUNDERSTORMS WILL CONTINUE TO BE A CONCERN FOR FAR WESTERN AND NORTHERN TERMINALS THROUGH ROUGHLY 03Z...AND KSNY THROUGH 05Z. BRIEF HEAVY RAIN...MODERATE TURBULENCE AND GUSTY WINDS UP TO 45 MPH WILL BE THE MAIN THREATS. MVFR/IFR CIGS STILL LOOK TO AFFECT KAIA AND KCDR AFTER 09Z TONIGHT...WITH CONDITIONS SLOW TO IMPROVE THROUGH TUESDAY. ELSEWHERE...EXPECT VFR CONDITIONS TO PREVAIL...WITH ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS ANTICIPATED FOR TUESDAY AFTERNOON. && .FIRE WEATHER... ISSUED AT 230 PM MDT MON AUG 4 2014 MONSOONAL MOISTURE WILL STAY WITH US THROUGH MOST OF THE WEEK GIVING MOST AREAS CHANCES FOR WETTING RAINS AND THUNDERSTORMS ON A DAILY BASIS. WINDS TO REMAIN WEAK AND AFTERNOON HUMIDITIES FAIRLY HIGH...MITIGATING ANY FIRE WEATHER CONCERNS. MIN HUMIDITIES EXPECTED TO STAY IN THE MID 20 PERCENT RANGE THROUGH THE WEEK WITH EXCELLENT OVERNIGHT RECOVERIES. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ SHORT TERM...CLAYCOMB LONG TERM...RUBIN AVIATION...RJM FIRE WEATHER...CLAYCOMB
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1107 PM MDT MON AUG 4 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 213 PM MDT MON AUG 4 2014 .CURRENTLY...STORMS HAVE DEVELOPED OVER THE SOUTHWEST MOUNTAINS AND EASTERN MOUNTAINS THIS AFTERNOON. STORMS HAVE BEEN PRODUCING SOME LOCALLY HEAVY DOWNPOURS...WITH THE MAIN CONCERN BEING FOR THE STORMS TO MOVE SLOWLY OVER THE AREA BURN SCARS. SATELLITE SOUNDER DATA AND MODELS CONTINUE TO MOIST ATMOSPHERE WITH PRECIPITABLE WATERS MOSTLY RANGING FROM 0.75 TO ONE INCH OVER THE MOUNTAINS AND HIGH VALLEYS TO AROUND AN INCH ON THE PLAINS. .TONIGHT...HRRR AND 4KM NAM MODELS CONTINUE TO SUGGEST THE FIRST ROUND OF CONVECTION MOVING OFF OF THE MOUNTAINS IT THE LATER AFTERNOON AND EARLY EVENING. MODELS AND BUFKIT SOUNDINGS CONTINUE TO SHOW WEAK INSTABILITY ON THE PLAINS THIS EVENING...BECOMING MORE CAPPED FURTHER EAST. CONVECTION SHOULD WEAKEN AS IT MOVES EAST DURING THE EVENING...AND MAINTAINED THE SILENT POPS NEAR THE KANSAS BORDER. HRRR SUGGESTS THE NEXT DISTURBANCE...AS SEEN IN CONVECTION OVER NORTHWEST NEW MEXICO...WILL PASS MOVE NORTHEAST ACROSS THE CWA DURING THE EVENING REACHING THE EASTERN MOUNTAINS AFTER MIDNIGHT. SUSPECT ATMOSPHERE WILL BE STABLE BY MIDNIGHT...AND ONLY MAINTAINED POPS OVER THE WESTERN MOUNTAINS AT 06Z. .TUESDAY...PORTION OF SHORTWAVE SPINNING OVER NEVADA WILL CROSS THE CWA DURING THE AFTERNOON. PRECIPITABLE WATER VALUES WILL REMAIN AROUND AN INCH OVER THE MAINS AND 0.75 TO ONE INCH OVER THE MOUNTAINS. WITH THE SHORTWAVE APPROACHING...STORMS WILL DEVELOP AN HOUR TO TWO EARLIER THAN MONDAY. MAIN THREATS AGAIN WILL BE LOCALLY HEAVY DOWNPOURS..ESPECIALLY ON AREA BURN SCARS. WINDS ALOFT WILL INCREASE SO STORMS WILL BE MOVING SLIGHTLY FASTER. BEHIND THE TROUGH...DRYING OCCURS IN THE MID AND UPPER LEVELS BY LATER AFTERNOON. -PGW-- .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 213 PM MDT MON AUG 4 2014 TUE NIGHT... DISTURBANCE ALOFT SHOULD BE OVER EASTERN PLAINS WITH DRIER AIR GRADUALLY MOVING INTO THE MTNS. BEST CHANCE OF PRECIP WILL BE OVER THE FAR E PLAINS DURING THE EVENING...WITH ISOLD POPS (AT BEST) OVER THE CONTDVD. WED... SHOULD BE A RATHER DRY DAY AS DRIER AIR IS FCST TO BE OVER THE MTNS WITH THE DRIER ATMOSPHERE CREEPING INTO THE PLAINS. IN ADDITION...RIDGING AT MIDLVLS WILL BE OCCURRING OVER THE REGION. BELIEVE POPS THIS DAT WILL BE ISOLD AT BEST...AND WILL BE OVER THE HIGHEST TRRN. MAX TEMPS THIS DAY WILL BE WARM WITH HIGHS IN THE 90S MOST OF THE PLAINS. THU... THIS DAY WILL BE TRICKY. A COOL FRONT WILL MOVE ACROSS THE PLAINS EARLY IN THE DAY. CONVECTION WILL FIRE ACROSS THE HIGH PLAINS...BUT HOW FAR SOUTH WILL IT GET? GFS IS FARTHEST NORTH WITH BRUNT OF ACTIVITY OVER FAR NE CO...WHILE NAM AND EC ARE A BIT FARTHER SOUTH WITH THE ACTIVITY EXTENDING DOWN INTO EAST CENTRAL CO. FOR NOW HAVE PAINTED ISOLD POPS OVER THE ENTIRE REGION DURING THE AFTERNOON AND EVENING...BUT MAY NEED HIGHER POPS OVER THE FAR E PLAINS IN LATER UPDATES. MAX TEMPS ON THE PLAINS SHOULD BE AROUND 90F THIS DAY. MTNS SHOULD SEE ONLY ISOLD POPS. FRI... EC AND GFS IN DISAGREEMENT THIS DAY. BOTH BRING DOWN ANOTHER BOUNDARY WITH UPSLOPE FLOW. GFS APPEARS MORE STABLE AND KEEPS WX DRIER OVER OUR REGION WHILE EC A BIT MORE WETTER OVER THE FAR E PLAINS. FOR NOW KEPT ONLY ISOLD POPS OVER E PLAINS WITH ISOLD PRECIP OVER S MTN TOPS. REST OF MTNS DRY. MAX TEMPS ONCE AGAIN ABOUT 90F MOST OF PLAINS. WEEKEND... SIMULATIONS SHOW A BIT BETTER CHANCE OF PRECIP ALL AREAS AS MONSOON PLUME WILL LIKELY REDEVELOP OVER THE SW...WITH MOISTURE ADVECTING IN FROM E AZ AND W NM. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1057 PM MDT MON AUG 4 2014 VFR CIGS EXPECTED AT TAF SITES OVERNIGHT WITH ACTIVE MONSOON PLUME KEEPING -SHRA/-TSRA GOING OVER THE MOUNTAINS THROUGH THE NIGHT. A PASSING -SHRA COULD AFFECT THE KALS TAF SITE TOMORROW MORNING AS A DISTURBANCE WORKS ITS WAY EASTWARD ACROSS THE STATE. -TSRA WILL DEVELOP OVER THE EASTERN MOUNTAINS DURING THE MORNING WHICH WILL MOVE OFF INTO THE ADJACENT KCOS AND KPUB TAF SITES DURING THE EARLY AFTERNOON. ERRATIC WIND GUSTS UP TO 30 KTS AN LIGHTNING WILL BE THE PRIMARY THREATS. CIGS COULD BRIEFLY DROP INTO THE MVFR CATEGORY WITH LOCALLY HEAVY RAINFALL SHOULD A STRONGER STORM AFFECT THE TERMINALS. GIVEN THE HIT OR MISS NATURE TO THUNDERSTORMS TOMORROW WILL MAINTAIN VCTS IN THE TAFS FOR NOW. -KT && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...PGW LONG TERM...HODANISH AVIATION...KT
AREA FORECAST DISCUSSION
NWS MIAMI FL
201 AM EDT TUE AUG 5 2014 .AVIATION... MID AND HIGH CLOUDS REMAIN WITH AN AREA OF LIGHT RAIN NEARING TMB. OTHERWISE THE REST OF THE NIGHT SHOULD REMAIN QUIET WITH CANOPY OF MID/HIGH CLOUDS CONTINUING TO STREAM NORTH FROM THE KEYS. QUESTIONABLE AS TO HOW MUCH THESE CLOUDS EFFECT TIMING OF ACTIVITY TUESDAY. WESTERLY FLOW TOMORROW MEANS EARLIER SHOWERS AND STORMS AT KAPF PROGRESSING ACROSS THE PENINSULA TO THE EAST COAST IN THE AFTERNOON WITH VCTS AT ALL SITES. AREA OF LOW PRESSURE/SURFACE TROUGH WILL HAVE DEPARTED NORTHEAST BY THE END OF THE DAY. DEEP MOISTURE REMAINS WITH SOME STORMS PRODUCING BRIEF IFR POSSIBLY AT ALL TAF SITES TODAY. STORMS SHOULD END QUICKLY THIS EVENING. && .PREV DISCUSSION... /ISSUED 948 PM EDT MON AUG 4 2014/ UPDATE... ALTHOUGH CONDITIONS HAVE IMPROVED, THE LOW THAT BROUGHT THE SHOWERS AND THUNDERSTORMS TO SOUTH FLORIDA EARLIER TODAY STILL HAS THE POTENTIAL TO BRING ADDITIONAL PRECIP TO THE AREA. THE GULF COAST STILL LOOKS TO BE THE AREA TO HAVE THE BEST CHANCES, ALTHOUGH MUCH LIGHTER ACCUMULATIONS THAN EARLIER. THE EAST COAST OF SOUTH FLORIDA, AS WELL AS THE ATLANTIC WATERS, MAY SEE SOME SCATTERED SHOWERS DEVELOP THIS EVENING. THE HRRR STILL SHOWS THE POSSIBILITY OF SHOWERS, ALTHOUGH THE GFS AND ECMWF TEND TO KEEP ANY PRECIP ALONG THE COASTAL AREAS. GIVEN THE UNCERTAINTY, HAVE KEPT SCATTERED POPS IN THE FORECAST FOR NOW. PREV DISCUSSION... /ISSUED 740 PM EDT MON AUG 4 2014/ AVIATION... DEBRIS CLOUD FIELD FROM LARGE CONVECTIVE COMPLEX WILL GRADUALLY IMPROVE THROUGH THE NIGHT WITH VFR CONDITIONS EXPECTED AT ALL TERMINALS. ABUNDANT MOISTURE TO CONTINUE THROUGH TUESDAY WITH INCREASING THREAT FOR CLOUDS AND TSRA AFT 14-16Z WITH THE GREATEST PROBABILITY NEAR KPBI SO PLACED A PROB30 GROUP IN THEIR TAF FOR THE AFTERNOON. SURFACE WIND WILL BE L/V BECMG SW AT 5-10 KT AFT 14Z ALL SITES. KOB PREV DISCUSSION... /ISSUED 312 PM EDT MON AUG 4 2014/ DISCUSSION... LATEST SURFACE ANALYSIS MAP SHOWS A SURFACE TROUGH AXIS EXTENDING FROM NORTHEASTERN FLORIDA THROUGH COLLIER COUNTY`S COASTLINE. SHOWERS AND THUNDERSTORMS WILL CONTINUE TONIGHT AS THE LOW PRESSURE LOCATED ACROSS NORTHEASTERN FLORIDA PREVAILS. SOUTHERLY SURFACE FLOW WILL CONTINUE ACROSS SOUTH FLORIDA THROUGH AT LEAST THE MIDDLE OF THE WEEK. MOISTURE WILL CONTINUE ABUNDANT AND WARM TEMPERATURES WILL PREVAIL ACROSS THE PENINSULA THROUGH THIS PERIOD. WIND FLOW WILL THEN BECOME WEAK AS HIGH PRESSURE BUILDS ACROSS THE AREA BY WEDNESDAY. WIND FLOW WILL BECOME EASTERLY AND AFTERNOON SHOWERS AND THUNDERSTORMS WILL THEN PREVAIL FROM THAT POINT THROUGH THE WEEKEND AS BOTH COASTS SEA BREEZES DEVELOP AND INTERACT ACROSS THE LAKE REGION. MARINE... BERTHA WILL CONTINUE MOVING NORTH AND AWAY FROM THE BAHAMAS. SOUTHERLY WINDS ARE FORECAST TO REMAIN AROUND 5-15 KTS THROUGH AT LEAST WEDNESDAY. WEAKER WINDS WILL RETURN BY MID WEEK BEFORE A GENERAL SSE TO S FLOW IS PREVALENT BY THE END OF THE WEEK AND THIS WEEKEND. SCATTERED SHOWERS AND STORMS COULD LEAD TO GUSTY WINDS AND LOCALLY CHOPPIER CONDITIONS EACH DAY ALONG WITH REDUCED VISIBILITIES. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 91 76 90 77 / 60 30 40 30 FORT LAUDERDALE 91 78 92 79 / 50 20 40 30 MIAMI 92 78 91 78 / 50 20 40 30 NAPLES 90 77 90 77 / 50 20 40 30 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ SHORT TERM...84/AK LONG TERM....84/AK AVIATION...21/KM
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
345 AM EDT TUE AUG 5 2014 .SYNOPSIS... DRIER AIR WILL ENTER THE REGION FROM THE WEST TODAY AND WEDNESDAY PROVIDING WARMER AND DRIER WEATHER. UNSETTLED WEATHER WILL RETURN FOR THE WEEKEND ASSOCIATED WITH A FRONTAL SYSTEM. && .NEAR TERM /THROUGH TONIGHT/... SURFACE LOW PRESSURE OFF THE SOUTHEAST COAST HAS BEEN SHOWING SIGNS OF DEEPENING A BIT AND GRADUALLY LIFTING NORTHWARD OVER THE PAST 6 HRS WHILE THE UPPER TROUGH AXIS REMAINS TO THE WEST OVER THE OHIO/TENNESSEE VALLEYS. WEAK SHORTWAVE ENERGY WILL LIFT NORTHEAST ACROSS THE FORECAST AREA THIS MORNING THEN SHIFT OFF TO THE NORTHEAST WITH NVA DEVELOPING ACROSS THE AREA BY LATE AFTERNOON. FORECAST SOUNDINGS INDICATE DEVELOPING MID LEVEL CAPPING INVERSION WHICH SHOULD LIMIT CONVECTION AND PREVENT SEVERE THREAT. WEAK TO MODERATE INSTABILITY AND BETTER MOISTURE CONFINED TO THE EAST AND SOUTHEAST PARTS OF THE FORECAST AREA. ISOLATED SHOWERS OR THUNDERSTORMS POSSIBLE ACROSS THE EASTERN MIDLANDS. THE MAIN CONVERGENCE ASSOCIATED WITH THE NORTHWARD LIFTING SURFACE LOW ARE EXPECTED TO REMAIN ALONG AND OFF THE COAST. TEMPERATURES WILL AGAIN BE WARM TODAY AROUND 90 TO THE LOWER 90S. DRY WEATHER IS EXPECTED TONIGHT UNDER CLEARING SKIES WITH OVERNIGHT LOWS IN THE UPPER 60S TO AROUND 70. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... UPPER TROUGH AXIS SHIFTS EAST OF THE REGION BY WEDNESDAY ALLOWING BROAD WEST TO NORTHWESTERLY FLOW TO MOVE OVER THE FORECAST AREA...RESULTING IN DRIER AND WARMER AIR TO SETTLE OVER THE REGION AIDED BY WEAK DOWNSLOPING FLOW. A CAPPING MID LEVEL INVERSION AND PWAT VALUES BELOW 1.5 INCHES AND WEAK INSTABILITY WILL PROVIDE DRY WEATHER FOR WEDNESDAY AS TEMPERATURES CLIMB ABOVE NORMAL INTO THE MID 90S. THE UPPER PATTERN WILL BEGIN TO SHIFT THURSDAY AS ANOTHER UPPER TROUGH TRIES TO TAKE HOLD ACROSS THE EASTERN UNITED STATES. THIS WILL HELP DRIVE A COLD FRONT TOWARDS THE AREA THURSDAY. MOISTURE INCREASES WITH PWAT VALUES CLIMBING BACK TO NEAR 1.7 INCHES AND DAYTIME HEATING SHOULD SUPPORT ISOLATED CONVECTION. COMPRESSIONAL HEATING AHEAD OF THE FRONT THURSDAY WILL YIELD WARM TEMPERATURES IN THE MID TO UPPER 90S. THE FRONT SHOULD SLOW DOWN AND STALL ACROSS THE FORECAST AREA THURSDAY NIGHT. && .LONG TERM /FRIDAY THROUGH MONDAY/... UNSETTLED WEATHER RETURNS TO THE REGION THIS WEEKEND WITH A STALLED FRONTAL BOUNDARY IN THE AREA AND WEAK UPPER TROUGHING ACROSS THE MID-ATLANTIC AND SOUTHEAST STATES. ATMOSPHERIC MOISTURE WILL INCREASE SIGNIFICANTLY BY FRIDAY AFTERNOON AS PWAT VALUES RISE ABOVE 2 INCHES AND REMAIN SO THROUGH THE REST OF THE EXTENDED PERIOD...REACHING AS HIGH AS 2.25-2.30 INCHES...WHICH IS APPROACHING THE 99TH PERCENTILE. SLOW STORM MOVEMENT AND VERY HIGH ATMOSPHERIC MOISTURE CONTENT WILL LEAD TO THE POSSIBILITY OF A HEAVY RAIN THREAT AND ISOLATED FLOODING. HIGH CHANCE POPS FRIDAY THROUGH SUNDAY THEN A BIT LOWER BY MONDAY AS THE TROUGH FLATTENS. TEMPERATURES THROUGH THE EXTENDED WILL BE BELOW NORMAL WITH HIGHS IN THE UPPER 80S FRIDAY THEN BACK INTO THE LOWER TO MID 80S SAT- MON. && .AVIATION /07Z TUESDAY THROUGH SATURDAY/... FRONT REMAINS STATIONARY NEAR THE COAST. WAVE OF LOW PRESSURE OFFSHORE THE S SC COAST WILL SHIFT NE TODAY. AN E TO NE LOW LEVEL FLOW AHEAD OF THE LOW OFF THE ATLANTIC MAY PROVIDE SOME LOW CLOUDINESS LATE TONIGHT INTO THIS MORNING. LATEST HRRR INDICATES SUCH...AND RECENT OBS NEAR THE EASTERN MIDLANDS INDICATING SOME DEVELOPING. WILL EXPECT IFR TO POSSIBLY LIFR CIGS AT THE TERMINALS LATER TONIGHT INTO THIS MORNING...WITH SOME QUESTIONS ON VSBYS. SOME DRIER AIR WILL ENTER THE REGION FROM THE WEST TODAY AS UPPER TROUGH AXIS SLOWLY SHIFTS EAST THROUGH OUR REGION. LIMITED MOISTURE EXPECTED TO PRECLUDE CONVECTION OVER MOST OF OUR FORECAST AREA TODAY. SOME AFTERNOON PRECIP POTENTIAL E/SE FORECAST AREA NEAR OGB...BUT WILL LEAVE OUT MENTION IN THE TAF DUE TO LOW CONFIDENCE. EXTENDED AVIATION OUTLOOK...DRIER AIR MOVING IN WILL REDUCE LATE NIGHT/EARLY MORNING FOG POTENTIAL...AND MAY BE RESTRICTED TO THE FOG PRONE SITES AGS AND OGB. SCATTERED DIURNAL CONVECTION RETURNS FRIDAY THROUGH SUNDAY. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
118 AM EDT TUE AUG 5 2014 .SYNOPSIS... DRIER AIR WILL ENTER THE REGION FROM THE WEST TUESDAY AND WEDNESDAY PROVIDING WARMER AND DRIER WEATHER. UNSETTLED WEATHER WILL RETURN FOR THE WEEKEND ASSOCIATED WITH A FRONTAL SYSTEM. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... LOW PRESSURE OFF THE SOUTHEAST COAST WILL MOVE NORTH THROUGH TONIGHT. HOWEVER...MUCH OF THE CONVERGENCE ASSOCIATED WITH THE LOW PLUS THE DEEPER MOISTURE SHOULD STAY EAST OF THE FORECAST AREA. SCATTERED SHOWERS THAT MAINLY AFFECTED THE EAST PART OF THE AREA HAVE DISSIPATED WITH THE LOSS OF HEATING. THE LATEST HRRR DOES NOT INDICATE ADDITION SHOWERS OVERNIGHT. LOW-LEVEL MOISTURE AND DIURNAL COOLING SHOULD HELP SUPPORT STRATUS AND FOG DEVELOPMENT. MOST OF THE GFS AND NAM MOS PLUS SREF GUIDANCE INDICATE SOME FOG BUT THE FOG SHOULD BE LIMITED BY SOME CLOUDINESS AND INSTABILITY. THE LATEST HRRR INDICATES LITTLE FOG. WE FORECASTED PATCHY FOG. WE LEANED TOWARD THE WARMER TEMPERATURE GUIDANCE BECAUSE OF CLOUDINESS. && .SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/... THE MAIN UPPER TROUGH AXIS WILL SHIFT THROUGH THE REGION THROUGH THE DAY TUESDAY...FINALLY SHIFTING OFFSHORE BY TUESDAY NIGHT. THE MAIN UPPER FLOW WILL THEN FLATTEN OUT INTO WEDNESDAY...ALTHOUGH WINDS ALOFT WILL STILL BE MORE NORTHWESTERLY. WITH THIS PATTERN THE CHANCE FOR RAIN SHOULD BEGIN TO PUSH OFFSHORE THROUGH THE DAY TUESDAY AS DRIER AIR MOVES INTO THE REGION. THIS WILL LEAVE TUESDAY NIGHT THROUGH WEDNESDAY NIGHT DRY. THE MAIN UPPER PATTERN WILL THEN BEGIN TO SHIFT THURSDAY AS ANOTHER UPPER TROUGH TRIES TO TAKE HOLD ACROSS THE EASTERN UNITED STATES. THIS WILL HELP DRIVE A COLD FRONT TOWARDS THE AREA THURSDAY...WHICH WILL ONCE AGAIN LEAD TO AN INCREASE IN RAIN CHANCES. THE FRONT SHOULD SLOW DOWN AND STALL ACROSS THE FORECAST AREA THURSDAY NIGHT. AS FOR TEMPERATURES...WITH DRIER AIR AND MORE SUNSHINE TUESDAY...WOULD EXPECT THAT THE AFTERNOON HIGHS WILL INCREASE BACK INTO THE UPPER 80S AND LOWER 90S TUESDAY...AND INTO THE LOWER TO MIDDLE 90S WEDNESDAY. WITH AN INCREASE IN CLOUDS AHEAD OF THE FRONT THURSDAY...TEMPERATURES WILL COOL SLIGHTLY...BUT SHOULD STILL REACH THE 90S. && .LONG TERM /FRIDAY THROUGH MONDAY/... THE COLD FRONT THAT WILL STALL ACROSS THE REGION FRIDAY SHOULD LINGER THROUGH THE WEEKEND. THE MAIN UPPER PATTER REMAINS OUT OF THE NORTHWEST. THE UPPER FLOW PATTERN WILL ALIGN WITH THE STALLED FRONT FROM SOUTHERN SC WESTWARD INTO THE SOUTHERN PLAINS STATES. WEATHER SYSTEMS THAT FORM WEST ALONG THIS FRONT MAY BE ABLE TO TRACK EASTWARD AND THROUGH THE SOUTHEASTERN STATES THROUGH THE PERIOD. WOULD EXPECT THAT CHANCE POPS SHOULD CONTINUE THROUGH THE WEEKEND AND INTO THE EARLY PART OF NEXT WEEK DUE TO THE SURFACE BOUNDARY...AND ENERGY ALOFT MOVING ALONG THIS FRONT TOWARDS THE EAST. PWATS BACK UP AROUND 2 INCHES THROUGH THE PERIOD WILL ALLOW FOR A HEAVY RAINFALL POTENTIAL. GFS BEGINS TO SHOW A SURFACE WEDGE FLOW PATTERN EAST OF THE APPALACHIANS BEGINNING SUNDAY INTO MONDAY...WHICH SHOULD BRING TEMPERATURES BACK DOWN INTO THE 80S. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... FRONT REMAINS STATIONARY NEAR THE COAST. WAVE OF LOW PRESSURE OFFSHORE THE S SC COAST WILL SHIFT NE TODAY. AN E TO NE LOW LEVEL FLOW AHEAD OF THE LOW OFF THE ATLANTIC MAY PROVIDE SOME LOW CLOUDINESS LATE TONIGHT INTO THIS MORNING. LATEST HRRR INDICATES SUCH...AND RECENT OBS NEAR THE EASTERN MIDLANDS INDICATING SOME DEVELOPING. WILL EXPECT IFR TO POSSIBLY LIFR CIGS AT THE TERMINALS LATER TONIGHT INTO THIS MORNING...WITH SOME QUESTIONS ON VSBYS. SOME DRIER AIR WILL ENTER THE REGION FROM THE WEST TODAY AS UPPER TROUGH AXIS SLOWLY SHIFTS EAST THROUGH OUR REGION. LIMITED MOISTURE EXPECTED TO PRECLUDE CONVECTION OVER MOST OF OUR FORECAST AREA TODAY. SOME AFTERNOON PRECIP POTENTIAL E/SE FORECAST AREA NEAR OGB...BUT WILL LEAVE OUT MENTION IN THE TAF DUE TO LOW CONFIDENCE. EXTENDED AVIATION OUTLOOK...DRIER AIR MOVING IN WILL REDUCE LATE NIGHT/EARLY MORNING FOG POTENTIAL...AND MAY BE RESTRICTED TO THE FOG PRONE SITES AGS AND OGB. SCATTERED DIURNAL CONVECTION RETURNS FRIDAY THROUGH SUNDAY. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
355 AM CDT TUE AUG 5 2014 .DISCUSSION... 355 AM CDT FORECAST CONCERNS FOCUS ON RAIN AND THUNDER CHANCES DIMINISHING FROM THE NORTH TODAY AS WEAK COLD FRONT CONTINUES TO SAG SOUTH ACROSS THE FORECAST AREA...AND AGAIN WEDNESDAY INTO THURSDAY AS ANOTHER SHORT WAVE AND JET STREAK DIG SOUTHEAST ACROSS THE REGION. AREA OF RAIN/THUNDERSTORMS HAS PUSHED SOUTHEAST ACROSS THE FORECAST AREA SINCE YESTERDAY AFTERNOON IN ASSOCIATION WITH A WEAK COLD FRONT AND A DIGGING MID-LEVEL SHORT WAVE TROUGH. MOST OF THE RAIN WAS SOUTHEAST OF A PRINCETON ILLINOIS TO GARY INDIANA LINE AS OF 3 AM AND SHOULD CONTINUE TO FOCUS OVER THE SOUTHEAST THIRD OR SO OF THE CWA THIS MORNING AS THE MID-LEVEL WAVE AND AN EMBEDDED MCV PROPAGATE INTO INDIANA. HARD TO PLACE THE ACTUAL COLD FRONTAL BOUNDARY GIVEN LIGHT GRADIENT AND CONVECTIVE OUTFLOW CONTAMINATED SURFACE WIND FIELD...THOUGH IT APPEARS TO BE SOMEWHERE FROM NORTH OF KORD TO KDKB TO SOUTH OF KSQI IN LATEST SURFACE ANALYSIS. FRONT IS PROGGED TO CONTINUE TO DRIFT SOUTHEAST THIS MORNING BEHIND WEAK SURFACE WAVE WITH BEST POTENTIAL FOR DIURNAL SHOWER/THUNDERSTORM DEVELOPMENT LATER THIS MORNING AND THIS AFTERNOON TO BE ALONG/SOUTH OF THE FRONT ACROSS THE SOUTH/SOUTHEAST PART OF THE CWA. ALSO...WITH LITTLE PUSH TO THE FRONT AT THIS TIME...LOW STRATUS AND FOG WAS DEVELOPING INTO NORTHWEST AND NORTH CENTRAL IL...AND WILL LIKELY LINGER AFTER SUNRISE THIS MORNING. SOMEWHAT DRIER LOW LEVEL AIR WILL FILTER IN FROM THE NORTH BY TONIGHT AS HIGH PRESSURE SPREADS ACROSS THE NORTHERN GREAT LAKES REGION...AND THE FRONT MOVES INTO DOWNSTATE IL/IN. GUIDANCE IS IN GOOD AGREEMENT IN DIGGING ANOTHER SHORT WAVE ACROSS THE MIDWEST WEDNESDAY INTO THURSDAY HOWEVER...WITH OVERRUNNING OF THE LOW LEVEL FRONTAL ZONE DEVELOPING FROM NORTHWEST IOWA INTO CENTRAL ILLINOIS. MODEL TREND HAS BEEN TO DEVELOP FAIRLY STRONG FRONTOGENESIS ALONG THE ELEVATED BAROCLINIC ZONE BENEATH THE RIGHT ENTRANCE REGION OF A 90 KT UPPER JET STREAK THROUGH THURSDAY...BRINGING A COUPLE OF PERIODS OF RAIN AND THUNDERSTORMS BACK INTO THE FORECAST AREA FROM WEDNESDAY MORNING THROUGH THURSDAY NIGHT. THE POTENTIAL EXISTS FOR SOME LOCALLY HEAVY RAINFALL THURSDAY/THURSDAY NIGHT ACROSS SOUTHERN PARTS OF THE CWA...AS 2+ INCH PWATS SPREAD NORTH. GFS/WRF BOTH DELIVER MORE THAN AN INCH OF RAIN TO THE SOUTHERN CWA DURING THIS TIME. FRONTAL ZONE THEN SHIFTS SOUTH INTO THE OHIO VALLEY AS HIGH PRESSURE STRENGTHENS ACROSS THE NORTHERN GREAT LAKES REGION FRIDAY AND SATURDAY. EASTERLY LOW LEVEL FLOW AROUND THE HIGH FAVORS DRY WEATHER AND PREFER THE DRIER ECMWF SOLUTION FOR THIS PERIOD. ANOTHER UPPER TROUGH APPROACHES THE REGION BY MONDAY HOWEVER...WITH AN INCREASE IN RAIN CHANCES LATER SUNDAY INTO MONDAY. TEMPERATURES THROUGH THE FORECAST PERIOD WILL AVERAGE JUST A BIT BELOW NORMAL WITH THE COOLEST DAYS WEDNESDAY-THURSDAY REMAINING IN THE 70S. OTHERWISE AROUND 80/LOWER 80S APPEAR REASONABLE. SURFACE FLOW WILL BE OFF THE LAKE THROUGH MOST OF THE PERIOD KEEPING AREAS NEAR LAKE MICHIGAN A LITTLE COOLER. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * LINGERING SHOWERS EARLY THIS MORNING...WITH POSSIBLE REDEVELOPMENT BY MID MORNING. * FOG THIS MORNING...WITH OUTSIDE POSSIBILITY FOR BRIEF IFR CEILINGS. * VARYING WIND EARLY THIS MORNING BECOMING NORTHEAST. RODRIGUEZ //DISCUSSION...UPDATED 06Z... COMPLEX FORECAST EARLY THIS MORNING OWING TO REMAINING SHOWERS...A RELAXED SURFACE PATTERN WITH LINGERING BOUNDARIES SITUATED ACROSS THE REGION...AND DEVELOPING FOG THIS MORNING. LATEST RADAR IMAGERY DEPICTING AREA OF PRECIP SLOWLY MOVING EAST THROUGH NORTHEAST ILLINOIS AND NORTHWEST INDIANA...AND EXPECT THIS SLOW TREND TO CONTINUE AND EXIT THE REMAINING TERMINALS OVER THE NEXT ONE TO THREE HOURS. VFR CEILINGS IN PLACE WITH THIS LIKELY TO CONTINUE BUT WITH THE ADDED MOISTURE AND RELAXED SURFACE PATTERN AS WELL AS SLOWLY CLEARING SKIES...LOWER CEILINGS COULD DEVELOP EARLY THIS MORNING. HAVE MORE CONFIDENCE WITH FOG DEVELOPING THAN THESE LOWER CEILINGS AND HAVE LEFT OUT ANY MENTION OF IFR CEILINGS IN THE TAF...BUT WILL NEED TO CONTINUE TO MONITOR TRENDS. LIKELY SCENARIO FOR PRECIP CHANCES FOR LATER THIS MORNING INTO MID DAY WOULD BE FOR ANY FURTHER DEVELOPMENT TO BE JUST SOUTH OF THE TERMINALS WITH GYY HAVING THE BEST CHANCES. WILL NEED TO MONITOR THIS AS WELL WITH SOME ISOLATED SHOWER DEVELOPMENT PERSISTING OVER NORTHWEST ILLINOIS AT THIS TIME...AND WITH SHORT TERM GUIDANCE HINTING AT THIS POSSIBILITY OVER THE REMAINING TERMINALS LATER THIS MORNING. WINDS WILL LIKELY CONTINUE TO VARY AS THIS PRECIP PUSHES THROUGH...BUT AM ANTICIPATING SPEEDS TO REMAIN UNDER 10KT. WINDS WILL THEN TURN TO THE NORTHEAST LATER THIS MORNING AND REMAIN THIS DIRECTION THROUGH THE REST OF THE FORECAST PERIOD. RODRIGUEZ //ORD AND MDW CONFIDENCE...UPDATED 06Z... * MEDIUM HIGH CONFIDENCE WITH SHOWER TRENDS EARLY THIS MORNING...LOW CONFIDENCE WITH POSSIBLE REDEVELOPMENT. * HIGH CONFIDENCE WITH FOG AND MEDIUM CONFIDENCE WITH VIS...LOW CONFIDENCE WITH ANY BRIEF IFR CEILINGS. * MEDIUM CONFIDENCE WITH WIND SPEED/DIRECTION. RODRIGUEZ //OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z... WEDNESDAY...SLIGHT CHANCE OF EVE TSRA. EAST-NORTHEAST WINDS. THURSDAY...SLIGHT CHANCE OF TSRA. EAST-NORTHEAST WINDS. FRIDAY-SATURDAY...VFR LIKELY. EAST WINDS. BEACHLER && .MARINE... 222 PM CDT WEAK HIGH PRESSURE REMAINS OVER THE REGION WHILE A COLD FRONT HAS STALLED OVER THE SOUTHERN END OF THE LAKE. WINDS ARE NORTH BEHIND THE FRONT AND THEN ONSHORE SOUTH OF THE FRONT. THE FRONT WILL RESUME ITS SOUTHERLY PUSH LATE TONIGHT AND CLEAR THE SOUTHERN END OF THE LAKE EARLY TUESDAY MORNING. WINDS WILL ALSO INCREASE TO 10-20 KT TOMORROW OVER THE SOUTHERN TWO THIRDS OF THE LAKE. WAVES CONTINUE TO REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA. HIGH PRESSURE BUILDS IN BEHIND THE FRONT AND WINDS DIMINISH TUESDAY NIGHT TO 10-15 KT. THE HIGH REMAINS OVER THE LAKE THROUGH THE WEEKEND. NORTH TO NORTHEAST WINDS ARE EXPECTED THROUGH WEDNESDAY NIGHT. THEY THEN BECOME EAST THURSDAY NIGHT AND STAY THERE THROUGH THE WEEKEND AT 15 KT OR LESS. JEE && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
  [top] Area Forecast Discussion National Weather Service Lincoln IL 309 AM CDT Tue Aug 5 2014 .DISCUSSION... ISSUED 309 AM CDT Tue Aug 5 2014 SHORT TERM...Today through Thursday Scattered showers associated with a short-wave trough will continue to work their way east/southeast across the KILX CWA early this morning. Most of the precip will be east of the I-55 corridor by 12z, then into Indiana by 18z as trough passes to the east. Subsidence on the back side of the wave should lead to a mostly dry afternoon, although HRRR is hinting that a few additional showers may fire across the E/NE during the afternoon. Will go with isolated to scattered wording for today, as areal coverage will be rather limited. Morning clouds will gradually clear, with partly sunny conditions expected later in the day. Will be another warm/humid day with highs once again reaching the middle 80s. A lull in the precip chances will occur this afternoon through the evening as short-wave ridging prevails. The next in a series of waves will begin to approach from the northwest overnight, with all model solutions showing a large area of showers/thunder developing along/north of a stalled frontal boundary draped across Iowa. Precip will begin to push into the Illinois River Valley toward dawn Wednesday, so will carry low chance PoPs after midnight along/northwest of the Illinois River with dry conditions elsewhere. Showers and thunderstorms will spread across much of central Illinois on Wednesday, primarily impacting locations west of the I-57 corridor. Will carry likely PoPs across the west, tapering down to low chance along the Indiana border accordingly. SPC has indicated that a slight risk for severe storms may develop Wednesday afternoon and evening across northern Missouri into southwest Illinois. This severe risk is contingent upon vigorous short-wave currently over Utah maintaining its strength as it approaches from the west Wednesday evening. NAM remains most aggressive with this feature, while GFS is quite a bit weaker. If stronger NAM verifies, enough lift will be generated along/south of surface boundary within the unstable and moderately sheared airmass to support a few strong to severe storms with large hail/gusty winds across the southwest CWA Wednesday evening. Otherwise, expect showers and thunderstorms to become more numerous across the entire area Wednesday night into Thursday as upper wave tracks across the area and interacts with the stalled frontal boundary and very moist airmass. LONG TERM...Friday through Monday Once the Thursday wave passes to the east, frontal boundary will begin to get pushed southward by the end of the week. Models continue to struggle with this evolution, but general consensus shifts best precip chances into the Ohio River Valley on Friday, then even further south over the weekend. As a result, will focus chance PoPs across only the southern CWA on Friday. After that, Saturday and Sunday appear to be largely dry before the next potential wave approaches within the prevailing northwesterly flow pattern early next week. Will therefore go with a dry forecast during the weekend, with low chance PoPs returning by Monday. Barnes && .AVIATION... ISSUED 1137 PM CDT Mon Aug 4 2014 Showers and scattered storms continuing over central Illinois late Monday evening, most concentrated from KPIA southeast. The storms are likely to be out of the KPIA vicinity by the start of the TAF period, and will leave them out of there. KBMI, KCMI and KDEC also likely to see a period of these storms, and have gone with TEMPO groups for a couple hours to reduce visibility to around 2-3SM. Thunder threat around KSPI appears minimal. Have some concerns for visibility overnight, as a frontal boundary settles southward across northern Illinois. Latest satellite imagery showing some fairly substantial cloud breakup across Iowa and more sustained clearing further north in Minnesota. With the amount of rain that has fallen near KPIA Monday evening, any clearing with the light winds will cause visibilities to tank. Latest HRRR and RAP guidance focuses this more in Iowa and northwest Illinois. For now will include a TEMPO group at KPIA to bring visibility down to 3SM, but will need to watch this closely. Further east, the higher clouds should last longer into the night, and have kept visibility restrictions minimal for now. Later parts of the forecast mainly focus on a wind shift to the northwest and then north, as a cold front pushes through the area. Have maintained some VCTS mention at KCMI during the afternoon, with dry conditions elsewhere. Geelhart && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
102 AM CDT TUE AUG 5 2014 .DISCUSSION... 257 PM CDT THE FORECAST CHALLENGES ARE TIMING AND PLACEMENT OF THUNDERSTORM CHANCES THROUGH THIS WEEK WHICH IS PARTICULARLY CHALLENGING TONIGHT...WHILE FOR THE REMAINDER OF THE WORKWEEK THERE IS GRADUALLY INCREASING CONFIDENCE THAT AT LEAST SOME PARTS OF THE AREA WILL REMAIN PRIMARILY IF NOT ENTIRELY DRY. SYNOPSIS AND TONIGHT... A WEAK FRONTAL BOUNDARY DRAPED NEARLY WEST-TO-EAST FROM SOUTH DAKOTA THROUGH FAR SOUTHERN WI AND TO LOWER MI IS VERY SLOWLY SHIFTING SOUTH THIS AFTERNOON. THE PUSH BEHIND THIS WEAK CONVERGENCE ZONE IS ALMOST NON-EXISTENT WITH THE FRONT DRIVEN MORE BY MID/UPPER FORCING AND COOLER STORM OUTFLOWS. OUTSIDE OF SOME CELLS ON THE LAKE BREEZE NEAR CHICAGO....THE BULK OF THE CONVECTION THIS EARLY AFTERNOON HAS BEEN IN WI AND SE MN WHERE UPPER FORCING IS BETTER DUE TO THE APPROACH OF A SHORT WAVE TROUGH. AS THIS TROUGH APPROACHES INTO THE FORECAST AREA DURING THIS EVENING...STORM COVERAGE ACTUALLY WILL LIKELY INCREASE IN OUR FORECAST AREA...THOUGH A VERY GRADUAL WANE ON THE REGIONAL SCOPE IS ANTICIPATED WITH THE LOSS OF HEATING. THE STORMS HAVE BEEN SLOW-MOVING JUST AS THEY HAVE BEEN IN RECENT DAYS WITH LITTLE IN THE WAY OF STEERING FLOW AND WIND SHEAR. RADAR TRENDS FROM WI AND INITIAL EARLY STORMS IN OUR CWA INDICATE VERY PULSEY NATURE TO THE STORMS AND THAT WOULD BE EXPECTED INTO EVENING WITH PRESENT MID 60S DEW POINTS AND 1000-1500 J/KG OF MLCAPE IN A LOW WIND SHEAR ENVIRONMENT. STORMS SHOULD MAINLY TRIGGER OR FESTER ON OUTFLOWS. HAVE SEEN SOME GUSTS OVER 30 KT UPSTREAM...INCLUDING AT LA CROSSE AND MADISON. THOSE TYPE OF GUSTS AND SMALL HAIL ARE POSSIBLE WITH ANY OF THE STRONGER STORMS. HOWEVER THE DISJOINT OF HEATING OF THE DAY AND THE SHORT WAVE...AT LEAST FOR OUR FORECAST AREA...MAY PRECLUDE ANY SUCH STORMS. LOCALLY HEAVY RAIN WILL BE A GIVEN WITH SOME STORMS DUE TO THEIR SLOW MOVING NATURE. IF ANY OF THESE WERE TO PASS OVER A METRO AREA IN PARTICULAR...THERE COULD BE A BRIEF FLOODING CONCERN. OUTFLOWS WILL LEAD TO SOME QUICK TEMPERATURE DROPS THIS EVE. BECAUSE OF THAT SOME TEMPERATURE/DEW POINT SPREADS MAY BE LOW GOING INTO THE OVERNIGHT HOURS WHICH MAY PRESENT POSSIBLE PATCHY GROUND FOG AGAIN. IN ADDITION...WEB CAMS AND REPORTS HAVE INDICATED HAZE IN THE METRO AREA SO HAVE ADDED THAT INTO THE FORECAST THROUGH TUESDAY MORNING. TUESDAY... THE LEFT EXIT REGION OF THE UPPER JET AND ASSOCIATED WAVE WILL LIKELY STILL BE MOVING THROUGH THE FORECAST AREA EARLY IN THE MORNING...AT THIS TIME FAVORED IN THE EASTERN FORECAST AREA. THERE COULD BE SOME SHOWERS AND EVEN SOME STORMS WITH THIS. THE SURFACE BOUNDARY LOOKS TO HAVE MOVED/EVOLVED INTO THE SOUTHERN FORECAST AREA BY TUESDAY AFTERNOON WHERE DEW POINTS WILL AGAIN POOL IN THE MID 60S. INSTABILITY OF 1000 J/KG SHOULD BE ENOUGH TO PROMOTE ISOLATED TO SCATTERED STORMS AGAIN IN THE AFTERNOON AS A SURFACE HIGH BUILDS FROM THE NORTH AGAINST THE BOUNDARY...AIDED PARTLY BY A PUSH OFF THE LAKE. AGAIN STORMS SHOULD BE OF A PULSEY NATURE. SLIGHTLY COOLER HIGH TEMPERATURES ARE EXPECTED ESPECIALLY NORTH AND NEAR THE LAKE. WEDNESDAY THROUGH SUNDAY... THERE HAS BEEN PRONOUNCED MODEL SPREAD FOR NUMEROUS RUNS REGARDING RAIN CHANCES AND MAGNITUDES DURING WEDNESDAY AND THURSDAY. THIS SPREAD HAS NOW LOWERED WITH NCEP MODELS COMING MORE IN LINE WITH THE EC WHICH CONTINUES TO TREND MAINLY SOUTH OF THE AREA. THE BASIC UPPER PATTERN IS NORTHWEST FLOW ALOFT WITH THE OLD SURFACE BOUNDARY SERVING AS A STATIONARY/WARM FRONT...WITH ASCENT ALONG AND NORTH OF IT BEING SUPPORTED BY RIGHT ENTRANCE REGION UPPER DYNAMICS. THE CHALLENGING THING IS THAT DRIER MID TO LOW-LEVEL AIR WILL BE WORKING IN FROM THE NORTHEAST BEHIND THE TUESDAY BOUNDARY AND THAT LIKELY IS TO PROVIDE A TIGHT GRADIENT AT LEAST AT TIMES IN PRECIP ACROSS THE REGION WEDNESDAY THROUGH THURSDAY. THE FURTHEST OUTLYING NORTH MODEL HAD BEEN THE 12KM NAM-WRF...WHICH EVEN ITS 4KM NESTED SOLUTION DOES NOT AGREE WITH. THE 12Z GFS TRENDED FURTHER SOUTH AND EVEN ITS COURSER RESOLUTION IS LIKELY PARTLY RESPONSIBLE FOR ITS QPF...AND ASSOCIATED GRIDDED POPS FOR BEING FURTHER NORTH. BECAUSE OF THIS HAVE COLLABORATED WITH NEIGHBORING WFOS AND WPC TO PUSH GOING POPS FURTHER SOUTH INTO MAINLY SOUTH OF I-80 FOR MANY OF THOSE PERIODS. SO BASICALLY HAVE CHICAGO DRY TUESDAY THROUGH SUNDAY WITH A CHANCE FOR STORMS SOUTH...ESPECIALLY WEDNESDAY AND THURSDAY. MTF && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * LINGERING SHOWERS EARLY THIS MORNING...WITH POSSIBLE REDEVELOPMENT BY MID MORNING. * FOG THIS MORNING...WITH OUTSIDE POSSIBILITY FOR BRIEF IFR CEILINGS. * VARYING WIND EARLY THIS MORNING BECOMING NORTHEAST. RODRIGUEZ //DISCUSSION...UPDATED 06Z... COMPLEX FORECAST EARLY THIS MORNING OWING TO REMAINING SHOWERS...A RELAXED SURFACE PATTERN WITH LINGERING BOUNDARIES SITUATED ACROSS THE REGION...AND DEVELOPING FOG THIS MORNING. LATEST RADAR IMAGERY DEPICTING AREA OF PRECIP SLOWLY MOVING EAST THROUGH NORTHEAST ILLINOIS AND NORTHWEST INDIANA...AND EXPECT THIS SLOW TREND TO CONTINUE AND EXIT THE REMAINING TERMINALS OVER THE NEXT ONE TO THREE HOURS. VFR CEILINGS IN PLACE WITH THIS LIKELY TO CONTINUE BUT WITH THE ADDED MOISTURE AND RELAXED SURFACE PATTERN AS WELL AS SLOWLY CLEARING SKIES...LOWER CEILINGS COULD DEVELOP EARLY THIS MORNING. HAVE MORE CONFIDENCE WITH FOG DEVELOPING THAN THESE LOWER CEILINGS AND HAVE LEFT OUT ANY MENTION OF IFR CEILINGS IN THE TAF...BUT WILL NEED TO CONTINUE TO MONITOR TRENDS. LIKELY SCENARIO FOR PRECIP CHANCES FOR LATER THIS MORNING INTO MID DAY WOULD BE FOR ANY FURTHER DEVELOPMENT TO BE JUST SOUTH OF THE TERMINALS WITH GYY HAVING THE BEST CHANCES. WILL NEED TO MONITOR THIS AS WELL WITH SOME ISOLATED SHOWER DEVELOPMENT PERSISTING OVER NORTHWEST ILLINOIS AT THIS TIME...AND WITH SHORT TERM GUIDANCE HINTING AT THIS POSSIBILITY OVER THE REMAINING TERMINALS LATER THIS MORNING. WINDS WILL LIKELY CONTINUE TO VARY AS THIS PRECIP PUSHES THROUGH...BUT AM ANTICIPATING SPEEDS TO REMAIN UNDER 10KT. WINDS WILL THEN TURN TO THE NORTHEAST LATER THIS MORNING AND REMAIN THIS DIRECTION THROUGH THE REST OF THE FORECAST PERIOD. RODRIGUEZ //ORD AND MDW CONFIDENCE...UPDATED 06Z... * MEDIUM HIGH CONFIDENCE WITH SHOWER TRENDS EARLY THIS MORNING...LOW CONFIDENCE WITH POSSIBLE REDEVELOPMENT. * HIGH CONFIDENCE WITH FOG AND MEDIUM CONFIDENCE WITH VIS...LOW CONFIDENCE WITH ANY BRIEF IFR CEILINGS. * MEDIUM CONFIDENCE WITH WIND SPEED/DIRECTION. RODRIGUEZ //OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z... WEDNESDAY...SLIGHT CHANCE OF EVE TSRA. EAST-NORTHEAST WINDS. THURSDAY...SLIGHT CHANCE OF TSRA. EAST-NORTHEAST WINDS. FRIDAY-SATURDAY...VFR LIKELY. EAST WINDS. BEACHLER && .MARINE... 222 PM CDT WEAK HIGH PRESSURE REMAINS OVER THE REGION WHILE A COLD FRONT HAS STALLED OVER THE SOUTHERN END OF THE LAKE. WINDS ARE NORTH BEHIND THE FRONT AND THEN ONSHORE SOUTH OF THE FRONT. THE FRONT WILL RESUME ITS SOUTHERLY PUSH LATE TONIGHT AND CLEAR THE SOUTHERN END OF THE LAKE EARLY TUESDAY MORNING. WINDS WILL ALSO INCREASE TO 10-20 KT TOMORROW OVER THE SOUTHERN TWO THIRDS OF THE LAKE. WAVES CONTINUE TO REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA. HIGH PRESSURE BUILDS IN BEHIND THE FRONT AND WINDS DIMINISH TUESDAY NIGHT TO 10-15 KT. THE HIGH REMAINS OVER THE LAKE THROUGH THE WEEKEND. NORTH TO NORTHEAST WINDS ARE EXPECTED THROUGH WEDNESDAY NIGHT. THEY THEN BECOME EAST THURSDAY NIGHT AND STAY THERE THROUGH THE WEEKEND AT 15 KT OR LESS. JEE && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 1146 PM CDT Mon Aug 4 2014 .DISCUSSION... ISSUED 834 PM CDT Mon Aug 4 2014 Convection that developed west of the Illinois River very late afternoon has diminished some and made it as far east as I-155. A large area of showers and thunderstorms was along and north of a frontal boundary, which extended from near Des Moines into the Chicago metro. Main threat of storms the rest of the night will be most concentrated along and west of I-55, as a shortwave drops southeast across Iowa. May see a few showers/storms as far southeast as I-70 after midnight, but areas south of there likely to remain dry overnight. Updated zones/grids have been sent. Geelhart && .AVIATION... ISSUED 1137 PM CDT Mon Aug 4 2014 Showers and scattered storms continuing over central Illinois late Monday evening, most concentrated from KPIA southeast. The storms are likely to be out of the KPIA vicinity by the start of the TAF period, and will leave them out of there. KBMI, KCMI and KDEC also likely to see a period of these storms, and have gone with TEMPO groups for a couple hours to reduce visibility to around 2-3SM. Thunder threat around KSPI appears minimal. Have some concerns for visibility overnight, as a frontal boundary settles southward across northern Illinois. Latest satellite imagery showing some fairly substantial cloud breakup across Iowa and more sustained clearing further north in Minnesota. With the amount of rain that has fallen near KPIA Monday evening, any clearing with the light winds will cause visibilities to tank. Latest HRRR and RAP guidance focuses this more in Iowa and northwest Illinois. For now will include a TEMPO group at KPIA to bring visibility down to 3SM, but will need to watch this closely. Further east, the higher clouds should last longer into the night, and have kept visibility restrictions minimal for now. Later parts of the forecast mainly focus on a wind shift to the northwest and then north, as a cold front pushes through the area. Have maintained some VCTS mention at KCMI during the afternoon, with dry conditions elsewhere. Geelhart && .PREV DISCUSSION... ISSUED 236 PM CDT Mon Aug 4 2014 SHORT TERM...Today through Wednesday Northwesterly flow aloft over and upstream of Illinois as a large scale high pressure ridge resides over the Rockies and a large scale trough resides over the eastern U.S. just east of Illinois. Disturbances embedded in the northwesterly flow upstream of Illinois and a cold front currently near the IL/WI border will be the main features bringing precipitation/thunderstorms to central IL through Tuesday. SHORT TERM...Today through Wednesday. Frontal boundary to the north expected to move into central IL overnight and to southeast IL late Tuesday. Thunderstorm activity currently over southern WI will spread into central IL as this occurs, however daytime heating will have ended bringing limiting surface-based instability. Mid-upper level instability should still be enough for some elevated convection however. As the front moves to Southeast IL Tuesday afternoon, thunderstorm activity should shift to that region. A bit of a break is likely Tuesday evening, then another disturbance brings stronger mid-level flow over the region late Tuesday night along with precipitable water increasing to around 2 inches interacting with the frontal zone stalled over the region. This should bring another good chance for showers and thunderstorms through Wednesday, some with potentially heavy rainfall. Instability looks to be minimal so severe thunderstorm potential remains minimal, primarily over west-central IL. LONG TERM...Thursday through Monday. The frontal boundary is expected to linger for a few days, eventually pushing southward late in the week. As a result, chance PoPs remain in the forecast through Friday, gradually moving off to the south. A basically dry forecast is in store for the weekend with the frontal boundary moving to the south however models still indicate disturbances moving across the top of the ridge to the west could affect portions of western Illinois, and have kept slight chances in for this possibility. Onton && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
452 AM EDT TUE AUG 5 2014 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 359 AM EDT TUE AUG 5 2014 A COLD FRONT MOVING INTO THE AREA WILL BRING CHANCES FOR THUNDERSTORMS TO CENTRAL INDIANA TODAY. THIS FRONT WILL STALL SOMEWHERE IN THE AREA AND UPPER WAVES WILL INTERACT WITH IT THROUGH THE REST OF THE WEEK KEEPING THUNDERSTORM CHANCES IN THE FORECAST. NEAR NORMAL TEMPERATURES WILL TAKE A SMALL DIP IN THE WAKE OF THE COLD FRONTAL PASSAGE WEDNESDAY AND THURSDAY BEFORE REBOUNDING TO NORMAL FROM THURSDAY ON. && .NEAR TERM /TODAY/... ISSUED AT 359 AM EDT TUE AUG 5 2014 RADAR MOSAIC SHOWS SHOWERS AND THUNDERSTORMS MOVING INTO THE NORTHWESTERN COUNTIES BUT SHRINKING AS THEY DO. THESE WILL SLOWLY MOVE IN BUT COVERAGE WILL BE LESS AND LESS BASED ON CURRENT TRENDS. THUS KEPT POPS AT CHANCE/SCATTERED OR LESS FOR THE REST OF THE EARLY MORNING. AFTER THAT SHORT TERM MODELS ARE SHOWING EVEN LESS COVERAGE BUT PERHAPS AN INCREASE AGAIN IN THE AFTERNOON. TRIED TO TIME THE POPS FOR THE TODAY PERIOD WITH THE MOVEMENT OF THE UPPER WAVE AND KEPT THE HIGHEST POPS ACROSS THE NORTH. BROUGHT A SLIGHT CHANCE IN ACROSS THE SOUTH FOR THE AFTERNOON INSTEAD OF KEEPING THINGS DRY WITH RAP SHOWING SOME DEVELOPMENT THERE AS WELL BUT THE BEST FORCING STAYING FAR FROM THERE. FOR TEMPERATURES THOUGHT THE CONSENSUS NUMBERS DID A GOOD JOB. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/... ISSUED AT 359 AM EDT TUE AUG 5 2014 FOR TONIGHT CONTINUED WITH SOME POPS AS A CARRYOVER FROM TODAY AS THE UPPER WAVE WILL BE MOVING OUT. BY LATE TONIGHT WENT DRY WITH LITTLE FORCING PRESENT. FOR WEDNESDAY MODELS HAVE TRENDED DRIER THIS RUN. NOT READY TO BUY THIS FULL ON SINCE LAST NIGHT/S RUNS HAD WEDNESDAY LOOKING FAIRLY WET. THUS BLENDED PREVIOUS AND CURRENT SOLUTIONS TO PROVIDE A COMPROMISE OF LOW CHANCE POPS ACROSS THE AREA. THE BEST FORCING WILL NOT BE ARRIVING UNTIL VERY LATE WEDNESDAY NIGHT INTO THURSDAY WITH A SHORTWAVE PROVIDING ADDITIONAL FORCING TO THE FRONT WHOSE EXACT POSITION IS STILL VARIABLE BETWEEN MODELS AND RUN-TO-RUN. WENT WITH THE HIGHEST POPS IN THE PERIOD ON THURSDAY WITH THE FORCING FROM THE UPPER WAVE. IF THE SURFACE FRONT SETS UP JUST TO THE SOUTH OR RIGHT ACROSS THE AREA HEAVY RAIN COULD BE A PROBLEM...BUT AT THIS POINT THE EXACT LOCATION OF THAT FRONT IS STILL VERY LOW CONFIDENCE. FOR TEMPERATURES THROUGH THE PERIOD GENERALLY USED A CONSENSUS. FOR THURSDAY/S HIGHS THOUGH WENT LOWER THAN THE MODEL AVERAGE TO REFLECT THE POTENTIAL FOR COOLER TEMPERATURES WITH THE HIGHER PROBABILITY FOR CLOUD COVER AND RAIN. && .LONG TERM /FRIDAY THROUGH MONDAY/... ISSUED AT 359 AM EDT TUE AUG 5 2014 THE THREAT FOR UNSETTLED WEATHER IS LIKELY TO PERSIST INTO THE WEEKEND AS NORTHWEST FLOW ALOFT REMAINS ACROSS THE REGION AND A FRONTAL BOUNDARY ALIGNS OVER THE TENNESSEE AND LOWER OHIO VALLEYS. 00Z MODEL SUITE HAS SHIFTED THE FRONT FURTHER NORTH FROM PREVIOUS RUNS...ESPECIALLY THE ECMWF AND OP GFS WHICH BOTH HAD MAINTAINED A MORE SUPPRESSED LOCATION TO THE BOUNDARY. DIFFERENCES REMAIN HOWEVER WITH RESPECT TO EVENTUAL LOCATION OF THE BOUNDARY BUT WITH A GENERAL CONSENSUS NOW PLACING IT JUST SOUTH OF THE REGION...CARRYING PRECIP CHANCES REMAINS WARRANTED INTO THE FIRST HALF OF THE WEEKEND. WILL PLACE HIGHEST POPS FRIDAY INTO EARLY SATURDAY OVER SOUTHERN COUNTIES AS A SURFACE WAVE RIDES ALONG THE BOUNDARY. WITH A DEEP MOIST AIRMASS IN PLACE FRIDAY/SATURDAY...HEAVY RAIN IS LIKELY TO ACCOMPANY STORMS. DRIER AIR ATTEMPTS TO MAKE A BRIEF APPEARANCE SATURDAY NIGHT WITH HIGH PRESSURE OVER THE NORTHERN GREAT LAKES...BUT THE ARRIVAL OF ADDITIONAL WAVES ALOFT AND THE REMNANT BOUNDARY LINGERING IN THE OHIO VALLEY SUPPORTS REINTRODUCING POPS INTO EARLY NEXT WEEK. TEMPERATURES WILL REMAIN SEASONABLE BUT CONTINUE TO RUN SLIGHTLY BELOW NORMAL THROUGH THE EXTENDED...WITH HIGHS RANGING FROM THE UPPER 70S TO MIDDLE 80S. && .AVIATION /DISCUSSION FOR THE 050900Z TAF UPDATE/... ISSUED AT 452 AM EDT TUE AUG 5 2014 ONLY MINOR CHANGES NEEDED TO THE FIRST FEW HOURS OF THE FORECASTS BASED ON CURRENT OBS. CONVECTION CONTINUES TO WEAKEN AND DIMINISH IN COVERAGE AS IT MOVES INTO OUR NORTHWEST COUNTIES...BUT MAY STILL PRODUCE A FEW SHOWERS IN THE VICINITY OF THE KLAF TERMINAL OVER THE NEXT FEW HOURS. 06Z DISCUSSION FOLLOWS. VFR THROUGH MUCH OF THE PERIOD...WITH SOME MVFR FOG POSSIBLE AT MAINLY THE OUTLYING SITES NEAR DAYBREAK. WINDS HAVE BECOME LIGHT TO CALM AND DEWPOINTS HIGH AGAIN TONIGHT. HOWEVER...SOME DEBRIS CLOUDINESS FROM UPSTREAM MAY BE A COMPLICATING FACTOR. WILL TAKE OUTLYING SITES DOWN TO MVFR AFTER ABOUT 08-09Z. ANY FOG WILL BURN OFF IN TYPICAL DIURNAL FASHION TUESDAY MORNING. CANNOT COMPLETELY RULE OUT A FEW STORMS NEAR LAF AND AT MOST SITES TUESDAY...BUT PROBABILITIES AND TOO LOW AND TIMING/PLACEMENT TOO UNCERTAIN FOR INCLUSION. WILL INCLUDE VCSH AT LAF FOR THE UPSTREAM CONVECTION THAT MAY BRUSH THE LAF AREA AS IT IS DISSIPATING. WINDS WILL BE BELOW 10KT THROUGHOUT THE PERIOD. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...CP NEAR TERM...CP SHORT TERM...CP LONG TERM....RYAN AVIATION...NIELD/RYAN VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSINDIANAPOLIS WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
410 AM EDT TUE AUG 5 2014 .UPDATE... THE SYNOPSIS...NEAR TERM...SHORT TERM AND LONG TERM SECTIONS HAVE BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 359 AM EDT TUE AUG 5 2014 A COLD FRONT MOVING INTO THE AREA WILL BRING CHANCES FOR THUNDERSTORMS TO CENTRAL INDIANA TODAY. THIS FRONT WILL STALL SOMEWHERE IN THE AREA AND UPPER WAVES WILL INTERACT WITH IT THROUGH THE REST OF THE WEEK KEEPING THUNDERSTORM CHANCES IN THE FORECAST. NEAR NORMAL TEMPERATURES WILL TAKE A SMALL DIP IN THE WAKE OF THE COLD FRONTAL PASSAGE WEDNESDAY AND THURSDAY BEFORE REBOUNDING TO NORMAL FROM THURSDAY ON. && .NEAR TERM /TODAY/... ISSUED AT 359 AM EDT TUE AUG 5 2014 RADAR MOSAIC SHOWS SHOWERS AND THUNDERSTORMS MOVING INTO THE NORTHWESTERN COUNTIES BUT SHRINKING AS THEY DO. THESE WILL SLOWLY MOVE IN BUT COVERAGE WILL BE LESS AND LESS BASED ON CURRENT TRENDS. THUS KEPT POPS AT CHANCE/SCATTERED OR LESS FOR THE REST OF THE EARLY MORNING. AFTER THAT SHORT TERM MODELS ARE SHOWING EVEN LESS COVERAGE BUT PERHAPS AN INCREASE AGAIN IN THE AFTERNOON. TRIED TO TIME THE POPS FOR THE TODAY PERIOD WITH THE MOVEMENT OF THE UPPER WAVE AND KEPT THE HIGHEST POPS ACROSS THE NORTH. BROUGHT A SLIGHT CHANCE IN ACROSS THE SOUTH FOR THE AFTERNOON INSTEAD OF KEEPING THINGS DRY WITH RAP SHOWING SOME DEVELOPMENT THERE AS WELL BUT THE BEST FORCING STAYING FAR FROM THERE. FOR TEMPERATURES THOUGHT THE CONSENSUS NUMBERS DID A GOOD JOB. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/... ISSUED AT 359 AM EDT TUE AUG 5 2014 FOR TONIGHT CONTINUED WITH SOME POPS AS A CARRYOVER FROM TODAY AS THE UPPER WAVE WILL BE MOVING OUT. BY LATE TONIGHT WENT DRY WITH LITTLE FORCING PRESENT. FOR WEDNESDAY MODELS HAVE TRENDED DRIER THIS RUN. NOT READY TO BUY THIS FULL ON SINCE LAST NIGHT/S RUNS HAD WEDNESDAY LOOKING FAIRLY WET. THUS BLENDED PREVIOUS AND CURRENT SOLUTIONS TO PROVIDE A COMPROMISE OF LOW CHANCE POPS ACROSS THE AREA. THE BEST FORCING WILL NOT BE ARRIVING UNTIL VERY LATE WEDNESDAY NIGHT INTO THURSDAY WITH A SHORTWAVE PROVIDING ADDITIONAL FORCING TO THE FRONT WHOSE EXACT POSITION IS STILL VARIABLE BETWEEN MODELS AND RUN-TO-RUN. WENT WITH THE HIGHEST POPS IN THE PERIOD ON THURSDAY WITH THE FORCING FROM THE UPPER WAVE. IF THE SURFACE FRONT SETS UP JUST TO THE SOUTH OR RIGHT ACROSS THE AREA HEAVY RAIN COULD BE A PROBLEM...BUT AT THIS POINT THE EXACT LOCATION OF THAT FRONT IS STILL VERY LOW CONFIDENCE. FOR TEMPERATURES THROUGH THE PERIOD GENERALLY USED A CONSENSUS. FOR THURSDAY/S HIGHS THOUGH WENT LOWER THAN THE MODEL AVERAGE TO REFLECT THE POTENTIAL FOR COOLER TEMPERATURES WITH THE HIGHER PROBABILITY FOR CLOUD COVER AND RAIN. && .LONG TERM /FRIDAY THROUGH MONDAY/... ISSUED AT 359 AM EDT TUE AUG 5 2014 THE THREAT FOR UNSETTLED WEATHER IS LIKELY TO PERSIST INTO THE WEEKEND AS NORTHWEST FLOW ALOFT REMAINS ACROSS THE REGION AND A FRONTAL BOUNDARY ALIGNS OVER THE TENNESSEE AND LOWER OHIO VALLEYS. 00Z MODEL SUITE HAS SHIFTED THE FRONT FURTHER NORTH FROM PREVIOUS RUNS...ESPECIALLY THE ECMWF AND OP GFS WHICH BOTH HAD MAINTAINED A MORE SUPPRESSED LOCATION TO THE BOUNDARY. DIFFERENCES REMAIN HOWEVER WITH RESPECT TO EVENTUAL LOCATION OF THE BOUNDARY BUT WITH A GENERAL CONSENSUS NOW PLACING IT JUST SOUTH OF THE REGION...CARRYING PRECIP CHANCES REMAINS WARRANTED INTO THE FIRST HALF OF THE WEEKEND. WILL PLACE HIGHEST POPS FRIDAY INTO EARLY SATURDAY OVER SOUTHERN COUNTIES AS A SURFACE WAVE RIDES ALONG THE BOUNDARY. WITH A DEEP MOIST AIRMASS IN PLACE FRIDAY/SATURDAY...HEAVY RAIN IS LIKELY TO ACCOMPANY STORMS. DRIER AIR ATTEMPTS TO MAKE A BRIEF APPEARANCE SATURDAY NIGHT WITH HIGH PRESSURE OVER THE NORTHERN GREAT LAKES...BUT THE ARRIVAL OF ADDITIONAL WAVES ALOFT AND THE REMNANT BOUNDARY LINGERING IN THE OHIO VALLEY SUPPORTS REINTRODUCING POPS INTO EARLY NEXT WEEK. TEMPERATURES WILL REMAIN SEASONABLE BUT CONTINUE TO RUN SLIGHTLY BELOW NORMAL THROUGH THE EXTENDED...WITH HIGHS RANGING FROM THE UPPER 70S TO MIDDLE 80S. && .AVIATION /DISCUSSION FOR THE 05/06Z TAFS/... ISSUED AT 1238 AM EDT TUE AUG 5 2014 VFR THROUGH MUCH OF THE PERIOD...WITH SOME MVFR FOG POSSIBLE AT MAINLY THE OUTLYING SITES NEAR DAYBREAK. WINDS HAVE BECOME LIGHT TO CALM AND DEWPOINTS HIGH AGAIN TONIGHT. HOWEVER...SOME DEBRIS CLOUDINESS FROM UPSTREAM MAY BE A COMPLICATING FACTOR. WILL TAKE OUTLYING SITES DOWN TO MVFR AFTER ABOUT 08-09Z. ANY FOG WILL BURN OFF IN TYPICAL DIURNAL FASHION TUESDAY MORNING. CANNOT COMPLETELY RULE OUT A FEW STORMS NEAR LAF AND AT MOST SITES TUESDAY...BUT PROBABILITIES AND TOO LOW AND TIMING/PLACEMENT TOO UNCERTAIN FOR INCLUSION. WILL INCLUDE VCSH AT LAF FOR THE UPSTREAM CONVECTION THAT MAY BRUSH THE LAF AREA AS IT IS DISSIPATING. WINDS WILL BE BELOW 10KT THROUGHOUT THE PERIOD. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CP NEAR TERM...CP SHORT TERM...CP LONG TERM....RYAN AVIATION...NIELD VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSINDIANAPOLIS WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1237 AM CDT Tue Aug 5 2014 ...Updated aviation discussion... .SYNOPSIS... ISSUED AT 349 PM CDT MON AUG 4 2014 Cirrus was slowly overspreading the western sections of Kansas from the mean height ridge moving eastward from the Rockies into the High Plains. A weak surface pressure/850 mb height gradient enveloped the Central Plains. Relative low pressure over the eastern Colorado resulted in a northward oriented pressure gradient gradient across western Kansas resulting in generally south winds at most locations with little downslope. Temperatures warmed to around 90 degrees across in most locations as dew points mixed down to the upper 40s from Scott City to Hugoton. Hays, which is closer to the warmer air at 850 mb warmed into the upper 90s. && .SHORT TERM...(This evening through Tuesday) ISSUED AT 349 PM CDT MON AUG 4 2014 The temperature trend and dew points to a lesser degree seemed to have followed the consensus of the short term models blend fairly well this afternoon. This trend will continue to be followed into the rest of the forecast including Tuesday morning and into Tuesday. The cirrus overhead may have a small impact on overnight lows as the recent updates have bumped lows into the mid and upper 60s in most locations. The HRRR model continues to show isolated to widely scattered convection across south central Kansas late this afternoon likely based on reaching convective temperatures. Current trends suggest this is overdone as was the case Sunday afternoon, and PoPs will not be added at this time. No major shift in airmass is taking place tonight and the same general pattern of surface winds and diurnal warming is expected heading into Tuesday afternoon. A breakdown in the ridge by a mid level shortwave will create scattered convection across northeast and east central Colorado by late in the afternoon. Low PoPs will be included for about the western half of the area starting at about about 23 UTC, following previous forecasts. .LONG TERM...(Tuesday night through Monday) ISSUED AT 341 PM CDT MON AUG 4 2014 The upper level ridge will flatten out and be shunted southward during the next couple of days as a series of upper level shortwaves move up and over the ridge. These features will bring a chance of thunderstorms to the forecast area through this weekend. The slight chance of thunderstorms will start out across far western Kansas Tuesday night then across central Kansas Wednesday night. Otherwise expect partly cloudy skies. Winds will generally be from the south to south southwest Tuesday night through Thursday with a surface trough located across eastern Colorado and far western Kansas. A better chance of thunderstorms will be expected this weekend as the upper level ridge retrogrades towards the southwest United States. Winds will generally be from the southeast during this time frame as a stationary front will be located at the surface south of the area with a dome of high pressure to the north. Highs through the extended period will generally be in the low to mid 90s with lows in the upper 60s and lower 70s. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) ISSUED AT 1236 AM CDT TUE AUG 5 2014 VFR conditions will prevail through this TAF period. South winds will generally be around 10 knots or less overnight but are expected to become a little more southwesterly and increase to around 15-20 knots with higher gusts by mid to late morning Tuesday. Isolated to widely scattered thunderstorms could impact the Garden City and Dodge City airports toward the end of this TAF period. Given the timing and expected nature of the storms, will hold off putting any mention of storms in the TAFs at this time. && .PRELIMINARY POINT TEMPS/POPS... DDC 69 95 68 93 / 20 20 20 10 GCK 68 94 67 92 / 20 20 10 20 EHA 67 95 67 94 / 20 10 10 20 LBL 69 96 68 95 / 20 10 10 10 HYS 70 94 68 91 / 20 30 30 20 P28 71 94 71 95 / 20 30 30 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...Russell SHORT TERM...Russell LONG TERM...Hovorka_42 AVIATION...Gerard
AREA FORECAST DISCUSSION...CORRECTED
NWS GAYLORD MI
445 AM EDT TUE AUG 5 2014 .SYNOPSIS... ISSUED AT 357 AM EDT TUE AUG 5 2014 ISOLATED SHOWERS AND THUNDERSTORMS ARE AGAIN POSSIBLE IN INTERIOR AREAS OF NORTHERN LOWER MICHIGAN THIS AFTERNOON AND EVENING. HIGH PRESSURE WILL THEN SETTLE IN OVER THE GREAT LAKES REGION WEDNESDAY. THIS HIGH PRESSURE WILL REMAIN IN CONTROL OF THE WEATHER THROUGH THE UPCOMING WEEKEND. TEMPERATURES WILL BE IN THE 70S TO LOWER 80S EACH DAY WITH LOWS GENERALLY IN THE 50S. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 357 AM EDT TUE AUG 5 2014 ...ONE MORE CHANCE FOR SHOWERS AND STORMS... IMPACTS: LIGHTNING THIS AFTERNOON...MAINLY SOUTH OF M-72. CURRENT WEATHER AND SYNOPTIC PATTERN: NO SURPRISE TO THE UPPER LEVEL PATTERN WITH TROUGHING ACROSS THE EASTERN COUNTRY INCLUDING THE GREAT LAKES...AND RIDGING OVER THE WEST. SFC HIGH PRESSURE AND DRIEST AIR WAS DRAPED FROM THE DAKOTAS THROUGH SRN ONTARIO...NOSING INTO EASTERN UPPER. A FRONTAL BOUNDARY WAS NOTED FROM THE EASTERN GREAT LAKES THROUGH SRN LOWER AND INTO WISCONSIN. THERE WAS AN AXIS OF INCREASED H8 MOISTURE AND ELEVATED FRONT STILL HOLDING ACROSS AREAS SOUTH OF M-32...WITH AN INCOMING SHORTWAVE IN NW FLOW ALOFT. THIS HAS RESULTED IN A BAND OF SHOWERS THERE...BUT NO THUNDER THUS FAR. THERE IS JUST A LACK OF INSTABILITY (WHICH REMAINS NEARER THE SFC FRONT IN SRN LOWER). SYNOPTIC PATTERN/WEATHER EVOLUTION: STILL FACING THE SAME PROBLEM WITH THE TODAY/TONIGHT FORECAST. THIS REVOLVES AROUND WHETHER OR NOT WE WILL SEE ANY AFTERNOON AND EVENING SHOWER AND THUNDERSTORM DEVELOPMENT. YESTERDAYS NON-ACTION WAS A LITTLE SURPRISING BUT RESULTED IN A QUICK LOOK BACK AT DATA. THE 00Z APX SOUNDING SHOWED MUCH DRIER AIR BELOW 750MB THAN WHAT WAS SUGGESTED IN YESTERDAYS DATA. MODELS HAVE OVER-FORECASTED BL MOISTURE OVER THE LAST FEW DAYS. LATEST RUC SHOWING A WEDGE OF DRIER H8 AIR SWEEPING DOWN INTO US BEHIND THE SHORTWAVE AND SHOWERS WHICH WILL DEPART BY MID MORNING. THIS WILL BRING A PERIOD OF QUIET NO PRECIP WEATHER. HEATING THROUGH THE DAY WILL ALLOW TEMPS TO MAX OUT HIGHER THAN GUIDANCE (ALSO RUNNING TOO COOL) IN THE MID AND UPPER 70S. FCST BFR SOUNDINGS SHOW INCORRECT INCREASED MOISTURE DEVELOPING AROUND H8 (A FUNCTION OF CONVECTION TAKING OFF IN THE MODELS)...WHAT IS MORE LIKELY IS FOR VERY SHALLOW RIDGING THIS AFTERNOON BEHIND THE WAVE...WITH VERY LITTLE IN THE WAY OF ADVECTION DUE TO CONTINUED LIGHT WINDS. AM EXPECTING THE BL TO MIX OUT DECENTLY AGAIN (BUT CURRENT RAINS WILL ADD TO LOW LEVEL MOISTURE AVAILABILITY). FCST SOUNDINGS SHOW CONTINUED COOLING ALOFT (WHICH SEEMS ODD CONSIDERING THE SHALLOW RIDGING)...AND SFC BASED DEW POINTS (OUTSIDE OF WHERE CURRENT RAIN SHOWERS RESIDE) ARE A COUPLE/FEW DEGREES TOO HIGH. REGARDLESS...EVEN TAKING A FAIRLY DRY PARCEL...MODIFICATION RESULTS IN SNEAKING BY A WEAK CAP ALOFT AROUND 600MB. 400-800 J/KG ARE SEEN IN INTERIOR NRN LOWER (WHERE LAKE BREEZE CONVERGENCE WILL MAXIMIZE). CAN SEE ISOLATED TO SCATTERED SHOWERS AND A FEW STORMS FIRING OFF...WITH NOTHING IN THE LAKE BREEZE CONVERGENCE IN MACKINAC COUNTY DUE TO TOO DRY OF AIR. THESE SHOWERS WILL LIKELY FADE OFF THROUGH EVENING...BUT WILL HAVE TO WATCH NEXT INCOMING SHORTWAVE FROM ONTARIO LATER TONIGHT. THERE MAY BE AN OUTSIDE CHANCE THAT A FEW OF THESE SHOWERS MAY BE ABLE TO CONTINUE INTO THE NIGHT...BUT CONFIDENCE IN THAT IS RATHER LOW. WILL END ALL SHOWERS BY MID/LATE EVENING. && .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 357 AM EDT TUE AUG 5 2014 ...QUIET THROUGH THE WEEKEND... OVERVIEW...THE BASICS OF THE PATTERN ARE GOING TO MOVE WITH THEM ONLY REESTABLISHING THEMSELVES BY NEXT WEEK. SO THE MAIN IDEA WILL BE THAT THE RIDGE IN THE WEST WILL MIGRATE EAST INTO THE UPPER GREAT LAKES. THIS WILL PRODUCE MAINLY DRY WEATHER THROUGH THE WEEKEND. THEN THE CHANCE OF SHOWERS AND THUNDERSTORMS MONDAY. SO WITH THAT IN MIND THE FORECAST LOOKS LIKE THIS... (8/6)WEDNESDAY AND (8/7)THURSDAY...THE SFC HIGH BUILDS OVER THE REGION WEDNESDAY AS A 500 MB SHORTWAVE TROUGH MOVES THROUGH THE REGION WITH FAIRLY DRY AIR (700-500 MB LAYER RH <30% AND 850 MB RH <50%). THIS LEAVES THE REGION RAIN FREE. THE SAME CONDITIONS ARE EXPECTED TO REMAIN OVER THE UPPER GREAT LAKES AS THE RIDGING TAKES PLACE THROUGH THE LOWER AND MID LEVELS. EXTENDED (FRIDAY THROUGH MONDAY)...THE RIDGING IS EXPECTED TO REMAIN FRIDAY AND SATURDAY AS WELL, AT LEAST ON THE ECMWF. THE GFS TRIES TO RAM RAIN NORTH INTO THE SW COUNTIES LATE ON SATURDAY AS SOME SHORTWAVE DIGS INTO THE 500 MB RIDGE. HOWEVER, THINK THAT THE ECMWF IS THE BETTER OF THE TWO MODELS AS THE 500MB RIDGING SHOULD REMAIN STRONG ENOUGH TO SHUNT THE SHORTWAVE NORTH. IT NOT UNTIL (8/10)SUNDAY THAT WE BEGIN TO GET A CHANGE FOR SOMETHING ORGANIZED. WHILE THE DAY AND NIGHT STILL REMAIN DRY, A 500 MB TROUGH AND SFC COLD FRONT BEGINS TO MARCH INTO THE UPPER GREAT LAKES, LATE ON SUNDAY NIGHT. THE MODELS ARE BEGINNING TO PUSH THE FRONT THROUGH ON MONDAY OR MONDAY NIGHT. THE ECMWF IS THE FASTER OF THE TWO MODELS, IN THIS CASE. SO WILL CONTINUE THE MONDAY POPS AND CONTINUE THEM INTO MONDAY NIGHT AS THE BOTH THE ECWMF AND THE GFS HAVE THE FRONT OVER THE FORECAST AREA OVERNIGHT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 139 AM EDT TUE AUG 5 2014 SOLID VFR CONDITIONS ARE EXPECTED AT ALL NRN LWR MICHIGAN TAF SITES THRU TUESDAY NIGHT AS HIGH PRESSURE GRADUALLY BUILDS INTO THE AREA. A MOISTURE-STARVED SHORT WAVE WILL SWING THRU AREAS SOUTH OF M-32 OVERNIGHT INTO EARLY TUESDAY...RESULTING IN A FEW SHOWERS AROUND TVC AND MBL AND WILL HANDLE WITH VCSH. LIGHT/VARIABLE WINDS OVERNIGHT INTO EARLY TUESDAY WILL BECOME N/NE AOB 10 KTS. && .MARINE... ISSUED AT 357 AM EDT TUE AUG 5 2014 NO WIND AND WAVE ISSUES TO BE CONCERNED WITH FOR SEVERAL DAYS...LIKELY THROUGH THE UPCOMING WEEKEND. HIGH PRESSURE TAKES CONTROL OF THE WEATHER WEDNESDAY ONWARD...WITH DRY AIR AND AFTERNOON LAKE BREEZES. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...NONE. LM...NONE. LS...NONE. && $$ SYNOPSIS...JL SHORT TERM...SMD LONG TERM...JL AVIATION...MR MARINE...SMD
AREA FORECAST DISCUSSION
NWS GAYLORD MI
405 AM EDT TUE AUG 5 2014 .SYNOPSIS... ISSUED AT 357 AM EDT TUE AUG 5 2014 ISOLATED SHOWERS AND THUNDERSTORMS ARE AGAIN POSSIBLE IN INTERIOR AREAS OF NORTHERN LOWER MICHIGAN THIS AFTERNOON AND EVENING. HIGH PRESSURE WILL THEN SETTLE IN OVER THE GREAT LAKES REGION WEDNESDAY. THIS HIGH PRESSURE WILL REMAIN IN CONTROL OF THE WEATHER THROUGH THE UPCOMING WEEKEND. TEMPERATURES WILL BE IN THE 70S TO LOWER 80S EACH DAY WITH LOWS GENERALLY IN THE 50S. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 357 AM EDT TUE AUG 5 2014 ...ONE MORE CHANCE FOR SHOWERS AND STORMS... IMPACTS: LIGHTNING THIS AFTERNOON...MAINLY SOUTH OF M-72. CURRENT WEATHER AND SYNOPTIC PATTERN: NO SURPRISE TO THE UPPER LEVEL PATTERN WITH TROUGHING ACROSS THE EASTERN COUNTRY INCLUDING THE GREAT LAKES...AND RIDGING OVER THE WEST. SFC HIGH PRESSURE AND DRIEST AIR WAS DRAPED FROM THE DAKOTAS THROUGH SRN ONTARIO...NOSING INTO EASTERN UPPER. A FRONTAL BOUNDARY WAS NOTED FROM THE EASTERN GREAT LAKES THROUGH SRN LOWER AND INTO WISCONSIN. THERE WAS AN AXIS OF INCREASED H8 MOISTURE AND ELEVATED FRONT STILL HOLDING ACROSS AREAS SOUTH OF M-32...WITH AN INCOMING SHORTWAVE IN NW FLOW ALOFT. THIS HAS RESULTED IN A BAND OF SHOWERS THERE...BUT NO THUNDER THUS FAR. THERE IS JUST A LACK OF INSTABILITY (WHICH REMAINS NEARER THE SFC FRONT IN SRN LOWER). SYNOPTIC PATTERN/WEATHER EVOLUTION: STILL FACING THE SAME PROBLEM WITH THE TODAY/TONIGHT FORECAST. THIS REVOLVES AROUND WHETHER OR NOT WE WILL SEE ANY AFTERNOON AND EVENING SHOWER AND THUNDERSTORM DEVELOPMENT. YESTERDAYS NON-ACTION WAS A LITTLE SURPRISING BUT RESULTED IN A QUICK LOOK BACK AT DATA. THE 00Z APX SOUNDING SHOWED MUCH DRIER AIR BELOW 750MB THAN WHAT WAS SUGGESTED IN YESTERDAYS DATA. MODELS HAVE OVER-FORECASTED BL MOISTURE OVER THE LAST FEW DAYS. LATEST RUC SHOWING A WEDGE OF DRIER H8 AIR SWEEPING DOWN INTO US BEHIND THE SHORTWAVE AND SHOWERS WHICH WILL DEPART BY MID MORNING. THIS WILL BRING A PERIOD OF QUIET NO PRECIP WEATHER. HEATING THROUGH THE DAY WILL ALLOW TEMPS TO MAX OUT HIGHER THAN GUIDANCE (ALSO RUNNING TOO COOL) IN THE MID AND UPPER 70S. FCST BFR SOUNDINGS SHOW INCORRECT INCREASED MOISTURE DEVELOPING AROUND H8 (A FUNCTION OF CONVECTION TAKING OFF IN THE MODELS)...WHAT IS MORE LIKELY IS FOR VERY SHALLOW RIDGING THIS AFTERNOON BEHIND THE WAVE...WITH VERY LITTLE IN THE WAY OF ADVECTION DUE TO CONTINUED LIGHT WINDS. AM EXPECTING THE BL TO MIX OUT DECENTLY AGAIN (BUT CURRENT RAINS WILL ADD TO OW LEVEL MOISTURE AVAILABILITY). FCST SOUNDINGS SHOW CONTINUED COOLING ALOFT (WHICH SEEMS ODD CONSIDERING THE SHALLOW RIDGING)...AND SFC BASED MOISTURE (OUTSIDE OF WHERE CURRENT RAIN SHOWERS RESIDE) IS A COUPLE FEW DEGREES TOO HIGH. ALL OF THIS REGARDLESS...EVEN TAKING A FAIRLY DRY PARCEL...MODIFICATION RESULTS IN SNEAKING BY A WEAK CAP ALOFT AROUND 600MB. 400-800 J/KG ARE SEEN IN INTERIOR NRN LOWER (WHERE LAKE BREEZE CONVERGENCE WILL MAXIMIZE). CAN SEE ISOLATED TO SCATTERED SHOWERS AND A FEW STORMS FIRING OFF...WITH NOTHING IN THE LAKE BREEZE CONVERGENCE IN MACKINAC COUNTY DUE TO TOO DRY OF AIR. THESE SHOWERS WILL LIKELY FADE OFF THROUGH EVENING...BUT WILL HAVE TO WATCH NEXT INCOMING SHORTWAVE FROM ONTARIO LATER TONIGHT. THERE MAY BE AN OUTSIDE CHANCE THAT A FEW OF THESE SHOWERS MAY BE ABLE TO CONTINUE INTO THE NIGHT...BUT CONFIDENCE IN THAT IS RATHER LOW. WILL END ALL SHOWERS BY MID/LATE EVENING. && .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 357 AM EDT TUE AUG 5 2014 ...QUIET THROUGH THE WEEKEND... OVERVIEW...THE BASICS OF THE PATTERN ARE GOING TO MOVE WITH THEM ONLY REESTABLISHING THEMSELVES BY NEXT WEEK. SO THE MAIN IDEA WILL BE THAT THE RIDGE IN THE WEST WILL MIGRATE EAST INTO THE UPPER GREAT LAKES. THIS WILL PRODUCE MAINLY DRY WEATHER THROUGH THE WEEKEND. THEN THE CHANCE OF SHOWERS AND THUNDERSTORMS MONDAY. SO WITH THAT IN MIND THE FORECAST LOOKS LIKE THIS... (8/6)WEDNESDAY AND (8/7)THURSDAY...THE SFC HIGH BUILDS OVER THE REGION WEDNESDAY AS A 500 MB SHORTWAVE TROUGH MOVES THROUGH THE REGION WITH FAIRLY DRY AIR (700-500 MB LAYER RH <30% AND 850 MB RH <50%). THIS LEAVES THE REGION RAIN FREE. THE SAME CONDITIONS ARE EXPECTED TO REMAIN OVER THE UPPER GREAT LAKES AS THE RIDGING TAKES PLACE THROUGH THE LOWER AND MID LEVELS. EXTENDED (FRIDAY THROUGH MONDAY)...THE RIDGING IS EXPECTED TO REMAIN FRIDAY AND SATURDAY AS WELL, AT LEAST ON THE ECMWF. THE GFS TRIES TO RAM RAIN NORTH INTO THE SW COUNTIES LATE ON SATURDAY AS SOME SHORTWAVE DIGS INTO THE 500 MB RIDGE. HOWEVER, THINK THAT THE ECMWF IS THE BETTER OF THE TWO MODELS AS THE 500MB RIDGING SHOULD REMAIN STRONG ENOUGH TO SHUNT THE SHORTWAVE NORTH. IT NOT UNTIL (8/10)SUNDAY THAT WE BEGIN TO GET A CHANGE FOR SOMETHING ORGANIZED. WHILE THE DAY AND NIGHT STILL REMAIN DRY, A 500 MB TROUGH AND SFC COLD FRONT BEGINS TO MARCH INTO THE UPPER GREAT LAKES, LATE ON SUNDAY NIGHT. THE MODELS ARE BEGINNING TO PUSH THE FRONT THROUGH ON MONDAY OR MONDAY NIGHT. THE ECMWF IS THE FASTER OF THE TWO MODELS, IN THIS CASE. SO WILL CONTINUE THE MONDAY POPS AND CONTINUE THEM INTO MONDAY NIGHT AS THE BOTH THE ECWMF AND THE GFS HAVE THE FRONT OVER THE FORECAST AREA OVERNIGHT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 139 AM EDT TUE AUG 5 2014 SOLID VFR CONDITIONS ARE EXPECTED AT ALL NRN LWR MICHIGAN TAF SITES THRU TUESDAY NIGHT AS HIGH PRESSURE GRADUALLY BUILDS INTO THE AREA. A MOISTURE-STARVED SHORT WAVE WILL SWING THRU AREAS SOUTH OF M-32 OVERNIGHT INTO EARLY TUESDAY...RESULTING IN A FEW SHOWERS AROUND TVC AND MBL AND WILL HANDLE WITH VCSH. LIGHT/VARIABLE WINDS OVERNIGHT INTO EARLY TUESDAY WILL BECOME N/NE AOB 10 KTS. && .MARINE... ISSUED AT 357 AM EDT TUE AUG 5 2014 NO WIND AND WAVE ISSUES TO BE CONCERNED WITH FOR SEVERAL DAYS...LIKELY THROUGH THE UPCOMING WEEKEND. HIGH PRESSURE TAKES CONTROL OF THE WEATHER WEDNESDAY ONWARD...WITH DRY AIR AND AFTERNOON LAKE BREEZES. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...NONE. LM...NONE. LS...NONE. && $$ SYNOPSIS...JL SHORT TERM...SMD LONG TERM...JL AVIATION...MR MARINE...SMD
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1200 AM CDT Tue Aug 5 2014 .UPDATE: Issued at 955 PM CDT Mon Aug 4 2014 Scattered thunderstorms that were over northern Missouri earlier this evening have dissipated. Still expect additional development over the next few hours as the RAP shows an increase in 925-850mb moisture convergence though 06Z over central and northeast Missouri and west central Illinois that will shift southeast across the CWA through 12Z. Have mainly slight chances of thunderstorms the rest of the evening, but then have low chance pops again overnight. Rest of the forecast including temperatures still looks good and have made only minor adjustments based on latest observations. Britt && .SHORT TERM: (Through Late Tonight) Issued at 356 PM CDT Mon Aug 4 2014 Weak warm advection has fueled the redevelopment of spotty convection just to the east of a KIRK-KCOU-Eminence line over the past few hours. Consensus of much of the short-range, hi-res guidance is that this activity will work east and likely weaken during the evening, but expect another uptick in PoPs after 06z as subtle veering of weak low level jet focuses somewhat stronger lift in a N-S axis roughly centered near or just west of STL area during the predawn hours. Overnight mins are expected to be a couple of degrees warmer than those of last night, primarily due to clouds. Truett .LONG TERM: (Tuesday through Next Monday) Issued at 356 PM CDT Mon Aug 4 2014 12z runs are forecasting a very subtle flattening of the mid level flow regime over the mid-Mississippi heading into midweek. This will cause a southward shift in the baroclinicity and frontal boundary currently locked to our north, and ultimately result in increasing rainfall chances over much of the CWA. By the end of the week, many parts of the CWA should have received some very welcomed wet weather. This morning`s runs offer fairly similar solutions regarding precip trends into Tuesday night. Thunderstorms that manage to develop overnight tonight should drift south and weaken on Tuesday morning, and I`ve continued low PoPs into tomorrow afternoon for areas along and south of a KCOU-KUIN line as surface boundary will be lingering over this part of the FA, and interacting with the increasingly unstable AMS driven by diurnal heating. Any storms that manage to develop Tuesday afternoon should weaken during the evening. Model consensus remains fairly good agreement with large scale trends heading into Tuesday night, with synoptic scale models all forecasting the intensification of the low level jet over the mid Missouri Valley during the late night hours. The resultant theta-e advection/lift should lead to the development of an MCS over IA that will roll southeast, with the leading edge of this system threatening northern sections of our CWA late Tuesday night. NAM is a bit further north with the QPF of this system than the GFS and the ECMWF, and since the NAM has been a bit too far north with the last few convective complexes, have given a nod to the consensus of the more southern solutions. Guidance specifics become a bit more murky heading into Wednesday and Thursday, but all solutions indicate persistent low level WAA into the area, combined with one or shortwaves/vort maxes drifting across the region. Thunderstorm threat on Wednesday will likely be a combination of the aforementioned MCS over northeast parts of the CWA, along with additional more scattered development occurring further to the south due to the above forcing mechanisms, along with possible outflow interaction and increasingly unstable afternoon airmass. Have continued our highest PoPs for Wednesday night and Thursday, as increased baroclinicity should lead to the best low level forcing during this time frame. Heading into the medium range ridge begins to re-exert its influence, but whats left of the westerly flow will allow weak dynamics to cross the area, interacting with the residualy unstable airmass and baroclinic zone that remains parked over the region. Have maintained earlier forecast trends for now, keeping fairly high PoPs into Thursday night, then slowly backing off to low/slight chance PoPs over the weekend and into early next week. Temperature-wise, fairly typical late summer readings can be expected tomorrow, but the combination of clouds and the southward push of cooler air should mean cooler weather over northeast parts of the CWA on Wednesday, and over the rest of the area by Thursday and Friday. Truett && .AVIATION: (For the 06z TAFs through 06z Tuesday Night) Issued at 1154 PM CDT Mon Aug 4 2014 Specifics for KCOU/KUIN: Scattered SH/TS will affect KCOU/KUIN over the next few hours before moving south and east of the terminals. A cold front will sink southward into the region overnight and tomorrow. Additional thunderstorms are possible at KCOU/KUIN during the afternoon hours depending on where the cold front is located relative to the terminals. Specifics for KSTL/KSUS/KCPS: Scattered SH/TS will reach metro area terminals within the next 1-2 hours. Additional thunderstorms are possible after 18z depending on the position of a slow-moving cold front. Kanofsky && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1156 PM CDT Mon Aug 4 2014 .SHORT TERM...(This Evening through Tuesday) Issued at 240 PM CDT MON AUG 4 2014 A nice cumulus field is developing with daytime heating and instability this afternoon especially over southern Missouri. There is a very subtle upper level shortwave moving through the area this afternoon. The latest HRRR is indicating isolated to scattered convection to develop by 22z near I-44 and move southward into the early evening hours. Will still carry 20 to 30 percent pops for this general area into the evening hours. Another upper level wave will move across the northern part of the state by early tomorrow morning with some possible convection making its way into central Missouri and the eastern Ozarks tomorrow morning. Will carry a slight mention of pops for tomorrow morning for this general area and a slightly better chance for convection east of Highway 65 Tuesday afternoon. .LONG TERM...(Tuesday Night through Monday) Issued at 240 PM CDT MON AUG 4 2014 The upper level ridge of high pressure which has been in control of our weather pattern will break down somewhat over us and allow multiple shortwaves to ride down a west-northwest flow. A front will meander into the region by Thursday and pretty much stall out over the Missouri Ozarks or nearby through weekend. There will be several rounds of convection and possible MCS activity riding along that front through the area. The first chance for widespread convection will be late Wednesday night into Thursday morning with another rounds developing Thursday night into Friday morning and possibly another round Friday night into Saturday morning. Timing and exact placement is difficult to pinpoint down at this time. The ECMWF is most bullish than the GFS and GEM but all have the same idea. Will mention a slight risk for heavy rainfall and some flash flooding threat for the end of the week with widespread one to three inches likely with isolated higher amounts over the eastern Ozarks and central Missouri areas. Temperatures by the end of the week will be dependent on where the stalled front is positioned and on going convection and cloud cover...but generally cooler temperatures in the lower 80s for the eastern half of the CWA and upper 80s for southeast Kansas and far southwest Missouri for the Thursday through Saturday time frame. The front finally lifts back to the north or washes out by early next week with temperatures moderating back to near normal and slight pops lingering in the afternoon. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday Night) Issued at 1147 PM CDT MON AUG 4 2014 For the KSGF/KJLN/KBBG tafs: VFR conditions are expected. A sfc trough will move slowly south into central/southern MO during the taf period veering winds to the west toward 15z. The trough may trigger some scattered convection once again Tue, but coverage is expected to be sparse, but maybe a little more than the past couple of days. && .SGF WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ SHORT TERM...Griffin LONG TERM...Griffin AVIATION...DSA
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
342 AM CDT TUE AUG 5 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 323 AM CDT TUE AUG 5 2014 TODAY AND TONIGHT...MIDLEVEL FRONTOGENESIS WOULD APPEAR TO SHIFT A BIT FARTHER SOUTH INTO NCNTL NEB TODAY ACCORDING TO THE RAP. NONE OF THE OTHER MODELS SHOW THIS BUT GIVEN THE COLD POOL WHICH FORMED IN THE WAKE OF LAST NIGHTS MCS ACROSS SRN SD...THIS WOULD APPEAR LOGICAL. THUS THE FORECAST TODAY AND TONIGHT CARRIES A HIGHER/LIKELY POP IN THE NORTHEAST ZONES WITH SCATTERED TO ISOLD COVERAGE FARTHER SOUTH WHERE THE ATMOSPHERE WILL REMAIN WARMER AND A BIT MORE CAPPED MOST OF THE DAY. H700 MB TEMPERATURES ARE COOL THROUGHOUT THE FCST AREA AT LESS THAN 14C. THE NAM INDICATES THE DISTURBANCE ACROSS SWRN COLORADO WILL MOVE ACROSS THE CNTL SANDHILLS THIS AFTN AND TONIGHT PRODUCING AN ORGANIZED AREA OF CONVECTION IN ADDITION TO THE CONVECTION WHICH WILL LIKELY CONTINUE ALONG AND NORTH OF THE MID LEVEL FRONTOGENESIS. PRECIPITABLE WATER IN THE GFS...NAM AND SREF INCREASE TO 1.5 INCHES OR HIGHER ACROSS ALL OF THE FCST AREA SUPPORTING SCATTERED OR GREATER STORM COVERAGE. THE RAP KEEPS IT AT 1.25 INCHES SOUTH OF THE STALLED FRONT ACROSS NCNTL NEB WITH THE 1.5 INCHES NORTH OF THE FRONT. THE RAP STILL DEVELOPS CONVECTION ACROSS THE SOUTH TODAY ASSOCIATED WITH A SURGE OF DRY AIR MOVING THROUGH THE PANHANDLE AND NERN COLO. A CHECK ON THE SEVERE WEATHER PARAMETERS SHOWS VERY MODEST SEVERE WEATHER POTENTIAL WITH 30 KTS OF BULK EFFECTIVE SHEAR ACROSS THE NORTHEAST AND AROUND 1500 J/KG OF CAPE. AN ISOLATED STORM WOULD SEEM POSSIBLE BUT NOT MUCH MORE IN THIS ENVIRONMENT. K INDICES RISE TO 40C OR GREATER THIS AFTERNOON AHEAD OF THE DRY SURGE AND ACROSS THE NRN ZONES. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 323 AM CDT TUE AUG 5 2014 THE FIRST IN A SERIES OF SHORTWAVES WILL CROSS THE AREA TUESDAY...WITH A COLD FRONT SETTLING SOUTH ACROSS KANSAS IN ITS WAKE ON WEDNESDAY. THE FRONT WILL REMAIN NEARLY STATIONARY THROUGH THE WEEKEND...WITH A SERIES OF SHORTWAVE DISTURBANCES TO PARADE EAST IN ZONAL FLOW ALOFT. THESE WAVES WILL INTERACT WITH A MOISTURE LATENT ATMOSPHERE TO THE NORTH OF THE FRONTAL ZONE ACROSS NEBRASKA...WITH PERIODIC CHANCES FOR SHOWERS/THUNDERSTORMS. THE FLOW ALOFT SHOULD BE STRONG ENOUGH TO PROMOTE SOME STORM ORGANIZATION...AND ONE OR TWO MESOSCALE CONVECTIVE COMPLEXES WILL BE POSSIBLE LATE WEEK INTO THE WEEKEND. PATTERN APPEARS TO SUPPORT THE POTENTIAL FOR SOME MUCH NEEDED RAINFALL ACROSS THE AREA. THE OTHER STORY WILL BE RELATIVELY COOL HIGH TEMPERATURES FOR THIS TIME OF YEAR. THIS SEEMS MOST LIKELY ACROSS NORTHERN NEBRASKA...WHERE HIGHS IN THE MID TO UPPER 70S CAN BE EXPECTED MID WEEK...WARMING TO THE LOW 80S DURING THE WEEKEND. ACROSS THE SOUTHWEST...MOSTLY MID TO UPPER 80S ARE EXPECTED EACH DAY. OVERNIGHT LOWS WILL AVERAGE NEAR NORMAL...IN THE 60S...AS HIGHER RELATIVE HUMIDITY WILL HELP KEEP THE MINIMUM TEMPERATURES MILD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1240 AM CDT TUE AUG 5 2014 CURRENT RADAR SHOWS A THUNDERSTORM SYSTEM ALONG THE NEBRASKA-SOUTH DAKOTA EAST OF IEN. THE STORMS COULD REACH VTN AS EARLY AS 07Z AND AS LATE AS 09Z. THE STORMS ARE LIKELY TO CONTINUE...AT LEAST INTERMITTENTLY FOR TWO HOURS. PROJECTING THE CURRENT MOVEMENT BRINGS THE STORMS TO VTN ABOUT 08Z. DUE TO THE UNCERTAINTY...WE WILL KEEP THEM IN THE TERMINAL FORECAST WITH A TEMPO GROUP FOR TWO HOURS. ADJUSTMENTS MAY BE NEEDED AS THE SITUATION EVOLVES. AFTER THE THUNDERSTORMS PASS...OCCASIONAL LIGHT SHOWERS WILL PROBABLY CONTINUE FOR AN ADDITIONAL 2 TO 4 HOURS. CURRENT INDICATIONS ARE THAT THE SHOWERS AND THUNDERSTORMS WILL REMAIN NORTH AND WEST OF AN ONL-TIF-AIA LINE. IN THE WAKE OF THE SHOWERS...A EAST WIND WILL CREATE AN UPSLOPE TRAJECTORY OF THE MOISTURE. AS A RESULT...LOW STRATUS CEILINGS ARE LIKELY. THERE IS SOME QUESTION IF THEY WILL BE ABOVE OR BELOW 1000 FEET AGL. FOR VTN...WE WILL HOLD THE CEILING TO JUST ABOVE 1000 FEET UNLESS THERE IS A CLEAR SIGNAL THAT IT WILL BE LESS THAN 1000 FEET AGL. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CDC LONG TERM...TAYLOR AVIATION...CDC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
328 AM CDT TUE AUG 5 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 325 AM CDT TUE AUG 5 2014 REGIONAL RADAR SHOWS SOME THUNDERSTORMS ACROSS SOUTHERN SOUTH DAKOTA AND NORTHERN NEBRASKA. THESE HAVE BEEN MOVING EAST OR SOUTHEAST. SURFACE OBSERVATIONS SHOW THAT SOME LIGHT FOG HAS FORMED IN SPOTS BUT SO FAR THE VISIBILITIES HAVE ONLY BEEN 3 TO 5 MILES. THE FIRST CONCERNS WILL BE WHETHER THE THUNDERSTORMS TO THE NORTH WILL GET INTO THE AREA THIS MORNING AND IF THE FOG WILL HAVE AN IMPACT ON VISIBILITY BY MORNING. WITH THE CURRENT MOVEMENT EXPECT THAT THE MAJORITY OF THE THUNDERSTORMS WILL REMAIN NORTH OF THE AREA BUT HAVE KEPT SOME LOW POPS IN THE FAR NORTH OR NORTHEAST. SO FAR THE VISIBILITY HAS BEEN ABOVE 3 MILES. WINDS ARE A LITTLE STRONGER THAN THEY WERE LAST NIGHT. THE LATEST HRRR CONTINUES TO SHOW LOWER VISIBILITY IN THE FAR NORTHEAST. WILL KEEP SOME PATCHY FOG IN FOR EARLY THIS MORNING. AN UPPER LEVEL WAVE APPROACHES THE AREA THIS AFTERNOON. A SURFACE LOW DEVELOPING ON THE HIGH PLAINS WILL MOVE INTO THE AREA DURING THE DAY. AS THE UPPER LEVEL WAVE MOVES INTO THE AREA...THUNDERSTORMS ARE EXPECTED TO FORM NEAR THE SURFACE LOW AND A SURFACE BOUNDARY EXTENDING TO THE EAST AHEAD OF THE SURFACE LOW. EXPECT A FEW OF THE STORMS COULD BE STRONG THIS AFTERNOON AND EVENING WITH GUSTY WINDS AND SOME SMALL HAIL. THE THUNDERSTORMS ARE EXPECTED TO CONTINUE ACROSS THE AREA TONIGHT AS THE UPPER WAVE MOVES THROUGH THE AREA AND THE SURFACE LOW MOVES INTO THE FORECAST AREA. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 325 AM CDT TUE AUG 5 2014 THE WEATHER PATTERN BECOMES MORE UNSETTLED DURING THE EXTENDED PERIODS. BEGINNING ON WEDNESDAY...CONVECTION MAY BE ONGOING FOR THE FIRST PART OF THE DAY AHEAD OF AN ADVANCING COLD FRONTAL BOUNDARY AS AN UPPER LOW PRESSURES SYSTEM TRANSLATES SOUTHEAST FROM THE DAKOTAS. ALSO A 40KT LOWLEVEL JET ORIENTED TOWARDS THE MO RIVER MAY SUSTAIN THE CONVECTION FOR SEVERAL HOURS IN THE MORNING. THIS INITIAL ROUND OF CONVECTION SHOULD DIMINISH WEDNESDAY MORNING WITH REDEVELOPMENT POSSIBLE DURING THE DAY ALONG THE ADVANCING COLD FRONT AND AS THE UPPER WAVE CONTINUES TO TRANSLATE SOUTHEASTWARD. A STRONG TO SEVERE STORM IS POSSIBLE WITH SREF INSTABILITY PROGS AROUND 2500 J/KG AND SHEAR NEAR 30KTS WHICH COULD LEAD TO A FEW STORMS CAPABLE OF PRODUCING LARGE HAIL/DAMAGING WINDS. PRECIPITABLE WATER VALUES ARE ON THE ORDER OF AN INCH AND A HALF AND IF STORMS CAN GO...DECENT RAINFALL AMOUNTS ARE POSSIBLE. THERE ARE SOME MODEL DIFFERENCES ON HOW QUICKLY THE BOUNDARY WILL MOVE THROUGH WEDNESDAY NIGHT WITH THE NAM FASTER THAN THE GFS WITH THE PROGRESSION. AS THE BOUNDARY MOVES THROUGH...PCPN CHANCES DECREASE N/S WITH COOLER AND DRIER AIR ADVECTING IN AS THE SURFACE RIDGE BUILDS SOUTH BEHIND THE BOUNDARY. THE MODEL DIFFERENCES CARRY INTO THURSDAY WITH THERMAL PROGS/TEMP PROFILES ON THE MODELS WITH THE NAM A FEW DEGREES COOLER WITH MID LEVEL TEMPS THAN THE GFS WHILE THE ECMWF IS IN BETWEEN THE TWO. HAVE WENT WITH MORE OF A MODEL BLEND FOR FORECAST HIGHS WITH THE THERMAL GRADIENT ORIENTED NE/SW. AFTER A MAINLY DRY DAY ON THURSDAY...CONVECTION IS EXPECTED TO REDEVELOP THURSDAY NIGHT TO OUR WEST ALONG THE HIGH PLAINS REGION IN UPSLOPE FLOW. THE GFS IS MORE ROBUST WITH THE CONVECTION WORKING EAST SOUTHEASTWARD THURSDAY NIGHT/EARLY FRIDAY THAN OTHER MODELS. DURING THIS TIME FRAME...THE GFS IS ALSO FARTHER NORTH WITH THE WARM FRONTAL BOUNDARY ACROSS KS WHEREAS NAM SUGGESTS THE BOUNDARY WILL BE IN OKLAHOMA. GIVEN THE UNCERTAINTY HAVE WENT WITH INCREASING CLOUD COVER AND KEPT THE BETTER PCPN CHCS IN OUR SW ZONES. FOR THE REMAINDER OF THE WORKWEEK AND INTO THE WEEKEND...THE PATTERN REMAINS UNSETTLED AS A SERIES OF WAVES CROSS THE INTERIOR CONUS AND THE UPPER RIDGE DAMPENS ACROSS THE SOUTHERN PLAINS. THE RIDGE BEGINS TO REBUILD TO THE NORTH AND WEST OVER THE ROCKIES LATE IN THE WEEKEND WITH A MORE AMPLIFIED NORTHWEST FLOW REGIME RETURNING BY DAY 7. CONVECTIVE POTENTIAL WILL BE DEPENDENT UPON TIMING OF WAVES AND FRONTAL BOUNDARY PLACEMENT WHICH WILL BE REFINED WITH TIME BUT THIS BEING SAID...THE WEATHER PATTERN DOES LOOK MORE ACTIVE DURING THE EXTENDED PERIODS WITH MORE PROMISING POTENTIAL FOR RAINFALL. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1208 AM CDT TUE AUG 5 2014 EXPECT THERE COULD BE SOME FOG AGAIN IN THE MORNING. THE LATEST HRRR MODEL HAS SOME SPOTTY VISIBILITY RESTRICTIONS JUST BEFORE SUNRISE THIS MORNING. WILL KEEP THE MVFR VISIBILITY GOING AND KEEP AND EYE ON WHETHER THE VISIBILITY DROPS LOWER. THE WORST SHOULD BE FURTHER TO THE EAST AND KEAR WILL LIKELY HAVE LESS VISIBILITY RESTRICTION. THERE IS A CHANCE FOR SOME THUNDERSTORMS DURING THE EVENING...BUT IT IS SMALL AND WILL KEEP THEM OUT OF THE TAF FOR NOW. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...JCB LONG TERM...FAY AVIATION...JCB
AREA FORECAST DISCUSSION
NWS RALEIGH NC
333 AM EDT TUE AUG 5 2014 .SYNOPSIS...LOW PRESSURE MOVES NORTHEAST JUST OFF OF THE CAROLINA COAST TODAY THROUGH THIS EVENING. WEAK HIGH PRESSURE WILL BE LOCATED OVER THE APPALACHIANS. A COLD FRONT MOVES SOUTH OVER THE REGION WEDNESDAY AFTERNOON INTO THURSDAY. && .NEAR TERM /THROUGH TODAY/... AS OF 305 AM TUESDAY... WITH LOW PRESSURE OFF OF THE CAROLINA COAST...THE LATEST IR FOG SATELLITE IMAGE SHOWED THE WESTERN EDGE OF A SHIELD OF MID- AND HIGH- LEVEL CLOUDS MAINLY ALONG AND EAST OF ABOUT U.S. 1...WITH PATCHY CIRRUS TOWARD THE TRIAD. UNDERNEATH THE HIGHER CLOUDS OBSERVATIONS SHOWED SOME LOW CLOUDS HAD FORMED...AND IT WAS NEAR THE WESTERN EDGE OF THE HIGHER CLOUDS THAT VISIBILITIES WERE LOWEST...PARTICULARLY TOWARD KHNZ AND FOR A TIME NEAR KTTA. AS NOTED IN THE AVIATION DISCUSSION BELOW...THE HRRR WRF EARLY THIS MORNING HAS BEEN CONSISTENT IN DEVELOPING THE LOWER-VISIBILITY FOG MAINLY FROM THE TRIANGLE NORTHEAST...WHICH SEEMS REASONABLE GIVEN THE ORIENTATION OF THE CLOUD SHIELD ALOFT AND THE LIGHT NORTHEAST LOW-LEVEL FLOW. THE GRIDDED FORECAST WILL NOTE AREAS OF FOG AND PATCHY DRIZZLE MAINLY FROM THE TRIANGLE NORTH AND NORTHEAST...WITH A SLIGHT CHANCE OF SHOWERS EARLY THIS MORNING ALONG AND EAST OF INTERSTATE 95 IN THE DEEPER MOISTURE CLOSER TO THE COASTAL LOW PRESSURE. WHILE THE RAP AND HRRR WRF ARE DRY IN CENTRAL NORTH CAROLINA TODAY...THE NAM HAS COPIOUS PRECIPITATION OVER A QUARTER-INCH IN A LARGE PART OF THE COASTAL PLAIN TODAY. LEANED WITH THIS FORECAST MORE TOWARD THE DRIER GUIDANCE...AS DRIER MID-LEVEL AIR WAS SLOWLY MOVING EAST INTO THE WESTERN PART OF THE STATE ON THE LATEST WATER VAPOR IMAGERY...AND ONLY WEAK LIFT FORECAST. GFS BUFR SOUNDINGS ARE STABLE...AND MEAN LAYER RELATIVE HUMIDITY IS FORECAST TO DECREASE GRADUALLY DURING THE DAY ON BOTH THE NAM AND GFS AS PRECIPITABLE WATER VALUES ALSO SLOWLY FALL. IT SHOULD BE NOTED THAT WITH THE BETTER MID-LEVEL WINDS MOVING THROUGH EARLY THIS MORNING...THERE HAVE BEEN A COUPLE OF SHOWERS THAT HAVE DEVELOPED VERY BRIEFLY OVER UPSTATE SOUTH CAROLINA. WILL CERTAINLY MONITOR RADAR TRENDS...BUT FOR NOW THE FORECAST WILL ONLY SHOW A SLIGHT CHANCE OF A SHOWER ALONG AND EAST OF ABOUT U.S. 1 WITH A CHANCE OF A SHOWER OR THUNDERSTORM FROM INTERSTATE 95 EAST. 1000- 850MB THICKNESSES SUPPORT HIGHS IN THE UPPER 80S...AND WHEN MORNING CLOUDS ARE CONSIDERED...WILL FORECAST HIGHS IN THE MID TO UPPER 80S UNDER A NORTH-TO-NORTHEAST WIND 10 MPH OR LESS. && .SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/... AS OF 305 AM TUESDAY... BUFR SOUNDINGS ARE STABLE OVERNIGHT ON BOTH THE NAM AND THE GFS...WITH THE GFS IN PARTICULAR SHOWING A SMALL VOLUME OF MID-LEVEL MOISTURE AS THE TROUGH AXIS ALOFT MOVES THROUGH AND A WEAK MID-LEVEL SHORTWAVE FOLLOWS THE TROUGH AXIS OVERNIGHT IN THE NORTHWEST FLOW. THIS SHOULD TRANSLATE INTO A PERIOD OF SCATTERED MID-LEVEL CLOUDS... POSSIBLY BROKEN FOR A PERIOD IF THE GFS VERIFIES. LOW-LEVEL MOISTURE REMAINS BEST TOWARD INTERSTATE 95 AND MAY NOTE PATCHY FOG POSSIBLE IN THE GRIDDED AND WORDED FORECASTS FOR THOSE AREAS LATE TONIGHT INTO VERY EARLY WEDNESDAY. OVERNIGHT LOWS 65 TO 70. WEDNESDAY AND WEDNESDAY NIGHT...GFS BUFR SOUNDINGS ARE STABLE WEDNESDAY...WHILE THE NAM SHOWS MODEST INSTABILITY PARTICULARLY TOWARD KRWI AND KFAY. ALTHOUGH THE GFS POPS ARE LOW THROUGHOUT CENTRAL NORTH CAROLINA...ITS QPF DOES NOTE A MINOR HUNDREDTH OR SO TOWARD THE COASTAL PLAIN WEDNESDAY AFTERNOON. SURFACE DEW POINTS SHOULD GENERALLY MIX WELL BASED ON THE BUFR SOUNDINGS AND A DEVELOPING WESTERLY SURFACE FLOW...MIXING LAST TOWARD THE COASTAL PLAIN WHERE THE COMBINATION OF JUST ENOUGH INSTABILITY...WEAK 850MB CONVERGENCE AND GRADUALLY LOWERING DEW POINTS COULD RESULT IN A VERY ISOLATED SHOWER OR STORM. THE MEAN AIR MASS STARTS TO MOISTEN WEDNESDAY NIGHT WITH THE APPROACH OF THE SURFACE FRONT...BUT WITH ONLY WEAK MID-LEVEL SUPPORT AND JET DYNAMICS NORTH OF THE AREA IN VIRGINIA...WILL LEAN TOWARD THE GFS AS OPPOSED TO THE WET NAM AND SHOW A DRY OVERNIGHT WEDNESDAY WITH AN EXPECTED INCREASE IN MID- LEVEL CLOUDS OVER MUCH OF THE AREA. 1000-850MB THICKNESSES SUPPORT HIGHS OF A BLEND OF MAV AND MET MOS GUIDANCE...OR 90 TO 95. OVERNIGHT LOWS WEDNESDAY NIGHT WITHIN A DEGREE OR THREE OF 70. -DJF THU/THU NIGHT: AN UPPER LEVEL TROUGH OVER NEW ENGLAND WILL LIFT INTO THE CANADIAN MARITIMES THU/THU NIGHT...WITH A WEAKENED WNW FLOW ALOFT OVER THE CAROLINAS. SUBSIDENCE IN THE WAKE OF THE TROUGH WILL RESULT IN SFC PRESSURE RISES OVER THE OH VALLEY AND MID ATLANTIC...WITH AN ATTENDANT SFC RIDGE AXIS /BACKDOOR COLD FRONT/ EXTENDING SOUTHWARD THROUGH VA TOWARD THE NC BORDER LATE THU. UNCERTAINTY PERSISTS W/REGARD TO THE TIMING/PROGRESS OF THE BACK DOOR COLD FRONT...LENDING A FAIR AMOUNT OF UNCERTAINTY TO TEMPERATURES...ESP ALONG AND NORTH OF HWY 64. AT THIS TIME WILL INDICATE HIGHS RANGING FROM ~90F SOUTH TO 83-85F NEAR THE VA BORDER. DESTABILIZATION/FORCING WILL HIGHLY DEPEND ON BOTH THE EVOLUTION OF THE FRONT AND OF SMALL AMPLITUDE DISTURBANCES IN WNW FLOW ALOFT... WITH CONSIDERABLE UNCERTAINTY IN PRECIP CHANCES/COVERAGE. AT THIS TIME WILL INDICATE A SLIGHT CHANCE DURING THE LATE AFTERNOON/EVENING HOURS. -VINCENT && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 330 AM TUESDAY... THE 00Z GFS/ECMWF ARE IN RELATIVELY GOOD AGREEMENT ON THE SYNOPTIC PATTERN FRI-MON. DESPITE GOOD SYNOPTIC AGREEMENT...SIGNIFICANT DISAGREEMENT ON MESOSCALE FEATURES AND CONVECTIVE EVOLUTION THROUGHOUT THE LONG TERM PERIOD LENDS ABOVE NORMAL UNCERTAINTY WITH REGARD TO PRECISE DETAILS (I.E. PRECIP AMOUNTS AND TIMING) FOR THE CAROLINAS. NORTHWEST FLOW ALOFT WILL PREVAIL OVER THE CAROLINAS FRI/SAT... DOWNSTREAM OF AN UPPER LEVEL RIDGE CENTERED OVER THE CENTRAL PLAINS/LOWER MIDWEST. THE UPPER LEVEL RIDGE IS PROGGED TO AMPLIFY AND RETROGRADE INTO THE ROCKIES ON SUN/MON...RESULTING IN A MORE AMPLIFIED PATTERN OF NNW FLOW ALOFT DOWNSTREAM OVER THE CAROLINAS. GIVEN AN ACTIVE UPPER LEVEL PATTERN JUXTAPOSED WITH MID-SUMMER MOISTURE...EXPECT ABOVE NORMAL CHANCES FOR PRECIPITATION AND BELOW NORMAL TEMPERATURES...PARTICULARLY SAT/SUN. -VINCENT && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... AS OF 155 AM TUESDAY... PATCHY MVFR AND IFR CONDITIONS IN FOG AND LOW CLOUDS WILL CONTINUE OVER CENTRAL NORTH CAROLINA DURING THE EARLY MORNING. THE LATEST SATELLITE IMAGES COMBINED WITH OBSERVATIONS SHOWED SOME LOWER CLOUDS TRYING TO MOVE TOWARD KINT...WITH A FEW LOW CLOUDS VISIBLE UNDERNEATH HIGHER CLOUDS IN THE SOUTHWEST FLOW ALOFT. FOG HAS BEEN DIFFICULT TO DEVELOP DUE TO THE MID- AND HIGH-LEVEL CLOUDS...AND THIS LIKELY WILL CONTINUE DURING THE REST OF THE MORNING. LIGHT FOG SEEMS REASONABLE...WITH THE HRRR WRF MODEL SHOWING THE BEST POTENTIAL FOR SOLID IFR FOG DEVELOPMENT ORIGINATING OVER SOUTHERN VIRGINIA WHERE THERE ARE FEWER MID- AND HIGH-LEVEL CLOUDS...THEN MOVING SOUTH-SOUTHWEST IN THE LIGHT LOW-LEVEL FLOW FROM ABOUT 07Z TO 12Z. THIS SEEMS A PLAUSIBLE SCENARIO...AND HAVE ACCOUNTED FOR THIS IN THE TAFS WITH THE LOWEST VISIBILITY FOR A PERIOD DURING THE EARLY MORNING AT KRWI AND KRDU. AS LOW PRESSURE MOVES NORTHEAST OFF OF THE CAROLINA COAST THERE IS AN OUTSIDE CHANCE OF A SHOWER MAINLY ALONG AND EAST OF INTERSTATE 95...BUT THE CHANCES SEEM TOO LOW TO INCLUDE IN A TAF POINT FORECAST. VFR CONDITIONS SHOULD PREVAIL OVER CENTRAL NORTH CAROLINA BY AFTERNOON UNDER A NORTHEAST WIND. EVENING WINDS... LIGHT AND VARIABLE...MAY SHOW A TENDENCY TO BECOME LIGHT SOUTHERLY BY THE END OF THE 06Z VALID TAF PERIOD. BEYOND THE 06Z VALID TAF PERIOD...PATCHY FOG AND SUB-VFR CONDITIONS ARE POSSIBLE LATE TONIGHT INTO EARLY WEDNESDAY...WITH THE BETTER CHANCES OF SUCH TOWARD KFAY AND KRWI. BEHIND A COLD FRONT WHICH SETTLES JUST SOUTH OF THE AREA BY LATE THURSDAY...CHANCES FOR PRECIPITATION WILL INCREASE. INTO SATURDAY...THE HIGHER CHANCES AS THEY DEVELOP ARE EXPECTED TO BE OVER THE SOUTHWEST PIEDMONT INTO THE SANDHILLS. STILL...AREAS OF SUB-VFR CONDITIONS IN LOWER CLOUDS ARE POSSIBLE THROUGHOUT MUCH OF CENTRAL NORTH CAROLINA DEVELOPING SATURDAY OR ESPECIALLY SATURDAY NIGHT. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DJF NEAR TERM...DJF SHORT TERM...DJF/VINCENT LONG TERM...VINCENT AVIATION...DJF
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
320 AM EDT TUE AUG 5 2014 .SYNOPSIS... A STALLED FRONT ALONG THE COAST WILL MOVE OFFSHORE TODAY AS HURRICANE BERTHA MOVES PASSES WELL OFFSHORE OF THE CAROLINA COAST. SWELLS FROM BERTHA WILL LEAD TO AN INCREASED RIP CURRENT RISK ALONG AREA BEACHES THE NEXT SEVERAL DAYS. WARM AND MUGGY WEATHER IS EXPECTED WEDNESDAY AND THURSDAY AHEAD OF AN APPROACHING COLD FRONT. HIGH PRESSURE WILL BUILD IN FRIDAY THROUGH THE WEEKEND...LIKELY HOLDING TEMPERATURES DOWN A FEW DEGREES BELOW NORMAL. && .NEAR TERM /THROUGH TONIGHT/... AS OF 3 AM TUESDAY...WE ARE JUST ABOUT TO GET RID OF THE DREARY WEATHER PATTERN THAT HAS BROUGHT UNSEASONABLY COOL...CLOUDY AND RAINY WEATHER TO THE COASTAL CAROLINAS FOR THE ENTIRE MONTH SO FAR. SO FAR AUGUST 2014 HAS SEEN THE 7TH COOLEST TEMPERATURES EVEN OBSERVED IN WILMINGTON WITH AN AVERAGE TEMPERATURE OF ONLY 75.7 DEGREES. HURRICANE BERTHA IS PASSING WELL EAST OF THE CAROLINAS WITH NO DIRECT IMPACTS ON OUR WEATHER TODAY. THE OLD STALLED FRONT APPEARS TO LIE ALONG THE BEACHES OF PENDER AND NEW HANOVER COUNTIES... EXTENDING SOUTHWARD FROM SOUTHPORT TO AN AREA OF LOW PRESSURE OFF THE GEORGIA COAST. THIS FEATURE SHOULD BE DRAWN EASTWARD BEHIND BERTHA TODAY...WITH DRIER AIR GRADUALLY BUILDING IN FROM THE NORTH WITH TIME. RADAR SHOWS PLENTY OF SHOWERS ACROSS THE COASTAL WATERS. THESE ARE SHALLOW CONVECTIVE FEATURES WITH ECHO TOPS GENERALLY 20KFT OR LESS...EXCEPT FOR A FEW T-STORMS FARTHER OFFSHORE WITH TOPS OVER 30KFT. SINCE THE BULK OF THIS ACTIVITY IS SHALLOW IT IS BEING STEERED BY THE 700-850 MB MEAN FLOW WHICH IS CURRENTLY FROM THE EAST. THE 00Z GFS AND 06Z RUC (OUR PREFERRED MODELS TODAY) SHOW THIS STEERING FLOW BACKING MORE NORTHERLY WITH TIME WHICH SHOULD TEND TO LIMIT HOW FAR INLAND ANY SHOWER ACTIVITY WILL MOVE. FORECAST POPS RANGE FROM 30-50 PERCENT ALONG THE COAST THIS MORNING...DIMINISHING TO 20-30 PERCENT BY NOON. FOR INTERIOR SECTIONS OF THE EASTERN CAROLINAS UNLESS AN ISOLATED SHOWER CAN DEVELOP DURING THE AFTERNOON DRY WEATHER IS EXPECTED. HIGHS SHOULD RANGE FROM THE UPPER 80S TO NEAR 90 ACROSS THE SC PEE DEE REGION TO THE MID 80S AT THE COAST. FOR TONIGHT DRY AIR SHOULD FLOOD IN THROUGHOUT THE TROPOSPHERE WITH PRECIPITABLE WATER VALUES FALLING TO LESS THAN 1.5 INCHES. SKIES SHOULD BECOME MAINLY CLEAR BY EARLY EVENING AND THERE IS LITTLE POTENTIAL FOR FOG OR LOW STRATUS OVERNIGHT. LOWS SHOULD TO NEAR 70. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 AM TUESDAY...SUMMER RETURNS ON WEDNESDAY AS THE MID LEVEL FLOW GOES WESTERLY AND DOWNSLOPE ALLOWING FOR A PARTLY SUNNY AFTERNOON. PIEDMONT TROUGH DEVELOPS BUT IT ALONG WITH THE SEA BREEZE WILL GENERALLY BE TOO MOISTURE-DEPRIVED TO LEAD TO MEANINGFUL PRECIP CHANCES. AFTERNOON TEMPERATURES WILL BE NEAR OR A FEW DEGREES ABOVE CLIMO. PIEDMONT TROUGH PUSHES TOWARDS THE COAST ON THURSDAY WHILE A MID LEVEL SHORTWAVE PASSES OVERHEAD LATE IN THE AFTERNOON. NORMALLY THIS WOULD BE A GOOD SETUP FOR THUNDERSTORMS. HOWEVER THERE IS STILL VERY LITTLE MOISTURE ESPECIALLY THROUGH THE MID LEVELS. CONVECTION WILL BE LIMITED AND GENERALLY BE CONFINED TO THE COASTAL REGIONS. TEMPERATURES WILL BE QUITE SIMILAR TO THOSE OF WEDNESDAY. A COLD FRONT WILL ENTER THE REGION LATE THURSDAY NIGHT AND WILL KEEP ISOLATED SHOWERS AND THUNDERSTORMS IN THE FORECAST. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 3 AM TUESDAY...HIGH PRESSURE BUILDING IN FROM THE NORTH BEHIND THURSDAY NIGHT COLD FRONT TO END THE BRIEF SHORT TERM PERIODS SUMMER TEMPS. MOISTURE MAY POOL ALONG THE FRONT AND BRING SOME SLIGHT RAIN CHANCES OVER SWRN ZONES. THIS WILL HOLD TRUE INTO SATURDAY AS THE FRONT WASHES BACK CLOSER TO THE AREA...THE LOW RAIN CHANCES MAY INCREASE IN AREA WHILE AFTERNOON HIGHS REMAIN CAPPED BELOW CLIMO. SUNDAY IS WHEN RAIN CHANCES SHOULD RETURN AREA-WIDE AS THE FRONT LIFTS BACK INTO THE REGION. WAVE MOVES BY LATE SUNDAY INTO SUNDAY NIGHT POSSIBLY FURTHER RAMPING UP RAIN CHANCES...AND THEN LEAVING THE BOUNDARY IN OUR PRESENCE SANS WAVE ON MONDAY. CYCLONIC AND NWRLY MID LEVEL FLOW CONTINUES ON TUESDAY WITH SURFACE TROUGHINESS REDEVELOPING. RAIN CHANCES WILL LINGER INTO TUESDAY WITH CLIMO OR HIGHER CHANCES WHILE TEMPS REMAIN NEAR OR JUST SHY OF CLIMO. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... AS OF 06Z...EARLY THIS MORNING ISOLATED SHOWERS EXTEND ALONG THE COAST. THROUGH 10Z THE BEST CHANCE OF CONVECTIVE SHRA/ISOLATED TSRA /MVFR CIGS WILL BE AT THE COASTAL TERMINALS WHERE THE BEST LIFT WILL BE. CANNOT RULE OUT SOME SCT IFR LEVEL CLOUDS BUT CHANCES OF IFR CIGS APPEAR LOW. THE CONVECTIVE SHRA/ISOLATED TSRA SHOULD BECOME PATCHY -RA AFTER 10Z OR SO AS DEEPER LIFT ABATES. -RA SHOULD END SHORTLY AFTER SUNRISE. AT KFLO/KLBT MVFR VSBYS IN BR EARLY THIS MORNING WILL LOWER TO LIFR VSBYS/CIGS IN FG/ST AROUND 09Z. FLIGHT CONDITIONS SHOULD IMPROVE TO VFR SHORTLY AFTER SUNRISE. EXPECT VFR IN THE MORNING HOURS TO CONTINUE THROUGH THE END OF THE TAF VALID PERIOD. ISOLATED SHOWERS WILL DEVELOP MAINLY COASTAL TERMINALS AFTER 15Z WHICH SHOULD ABATE IN THE LATE AFTERNOON. EXTENDED OUTLOOK...ISOLATED SHOWERS WED. SCATTERED SHOWERS LATE THURSDAY WITH A BETTER CHANCE FOR CONVECTION FRIDAY AND SATURDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 3 AM TUESDAY...AN OLD STALLED FRONT RUNS ALONG THE BEACHES OF SE NORTH CAROLINA SOUTHWARD INTO AN AREA OF LOW PRESSURE OFF THE GEORGIA COAST. HURRICANE BERTHA IS WELL EAST OF THE CAROLINAS AND WILL MOVE NORTHEASTWARD AND FARTHER AWAY TODAY. THE GEORGIA LOW AND OUR FRONT SHOULD BE DRAWN OFFSHORE TOWARD BERTHA...LEADING TO A DRYING TREND DEVELOPING WITH TIME. UNTIL THEN...WAVES OF SHOWERS AND EMBEDDED T-STORMS ACROSS THE COASTAL WATERS SHOULD CONTINUE THROUGH THE MORNING HOURS. GENERALLY EAST OR NORTHEAST WINDS WILL TURN NORTHERLY THIS EVENING...THEN WESTERLY OVERNIGHT AS BERTHA PULLS THE LOW AND FRONT AWAY FROM THE AREA. THIS WILL LET DRIER AIR FLOOD INTO THE AREA. A SIGNIFICANT SWELL FROM BERTHA WILL IMPACT THE WATERS TODAY AND SHOULD BE THE LARGEST CONTRIBUTING FACTOR IN SEA HEIGHT FORECASTS TODAY. SEAS OF 4-5 FEET ARE EXPECTED...DIMINISHING TO 3-4 FT LATE TONIGHT. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 AM TUESDAY...PIEDMONT TROUGH ON WEDNESDAY WILL BACK INITIALLY WEST FLOW TO SOUTHWEST OR EVEN SOUTH WHILE ADDING A FEW KNOTS TO AVERAGE SPEED. SEAS MAINLY COMPRISED OF WIND WAVES IN THE 2 TO 3 FT RANGE. AS THE BOUNDARY MOVES TOWARDS THE COAST ON THURSDAY THE WIND WILL DIMINISH LATER IN THE DAY AS THE GRADIENT IS PUSHED OUT TO SEA BY THE TROUGH. THE BOUNDARY WILL SINK SOUTH ACROSS THE ZONES RATHER SLOWLY LATE THURSDAY NIGHT BRINGING A TURN TO NORTHERLY WINDS FOLLOWED BY ADDITIONAL VEERING TO EASTERLY BY THE PERIODS END...AT LEAST FOR NORTHERN ZONES. LONG TERM /FRIDAY THROUGH SATURDAY/... AS OF 3 AM TUESDAY...POST-FRONTAL ONSHORE FLOW ON FRIDAY WILL BE IN THE 10 TO 15 KT RANGE EARLY BUT SETTLE BY ABOUT 5 KT. SEAS WILL BE RUNNING JUST 2-3 FEET THEN MOST AREAS. THE HIGH WILL CONTINUE WEDGING IN FROM POINTS NORTH INTO SATURDAY WHILE THE FRONT STALLED TO THE SOUTH TRIES TO MOVE BACK TO THE NORTH SLIGHTLY. WITH RELATIVELY UNCHANGED WINDS AND NO SWELL ENERGY TO SPEAK OF SEAS WILL REMAIN 2 FEET AGAIN ON SATURDAY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...TRA SHORT TERM...MBB LONG TERM...MBB AVIATION...MRR
AREA FORECAST DISCUSSION
NWS RALEIGH NC
305 AM EDT TUE AUG 5 2014 .SYNOPSIS...LOW PRESSURE MOVES NORTHEAST JUST OFF OF THE CAROLINA COAST TODAY THROUGH THIS EVENING. WEAK HIGH PRESSURE WILL BE LOCATED OVER THE APPALACHIANS. A COLD FRONT MOVES SOUTH OVER THE REGION WEDNESDAY AFTERNOON INTO THURSDAY. && .NEAR TERM /THROUGH TODAY/... AS OF 305 AM TUESDAY... WITH LOW PRESSURE OFF OF THE CAROLINA COAST...THE LATEST IR FOG SATELLITE IMAGE SHOWED THE WESTERN EDGE OF A SHIELD OF MID- AND HIGH- LEVEL CLOUDS MAINLY ALONG AND EAST OF ABOUT U.S. 1...WITH PATCHY CIRRUS TOWARD THE TRIAD. UNDERNEATH THE HIGHER CLOUDS OBSERVATIONS SHOWED SOME LOW CLOUDS HAD FORMED...AND IT WAS NEAR THE WESTERN EDGE OF THE HIGHER CLOUDS THAT VISIBILITIES WERE LOWEST...PARTICULARLY TOWARD KHNZ AND FOR A TIME NEAR KTTA. AS NOTED IN THE AVIATION DISCUSSION BELOW...THE HRRR WRF EARLY THIS MORNING HAS BEEN CONSISTENT IN DEVELOPING THE LOWER-VISIBILITY FOG MAINLY FROM THE TRIANGLE NORTHEAST...WHICH SEEMS REASONABLE GIVEN THE ORIENTATION OF THE CLOUD SHIELD ALOFT AND THE LIGHT NORTHEAST LOW-LEVEL FLOW. THE GRIDDED FORECAST WILL NOTE AREAS OF FOG AND PATCHY DRIZZLE MAINLY FROM THE TRIANGLE NORTH AND NORTHEAST...WITH A SLIGHT CHANCE OF SHOWERS EARLY THIS MORNING ALONG AND EAST OF INTERSTATE 95 IN THE DEEPER MOISTURE CLOSER TO THE COASTAL LOW PRESSURE. WHILE THE RAP AND HRRR WRF ARE DRY IN CENTRAL NORTH CAROLINA TODAY...THE NAM HAS COPIOUS PRECIPITATION OVER A QUARTER-INCH IN A LARGE PART OF THE COASTAL PLAIN TODAY. LEANED WITH THIS FORECAST MORE TOWARD THE DRIER GUIDANCE...AS DRIER MID-LEVEL AIR WAS SLOWLY MOVING EAST INTO THE WESTERN PART OF THE STATE ON THE LATEST WATER VAPOR IMAGERY...AND ONLY WEAK LIFT FORECAST. GFS BUFR SOUNDINGS ARE STABLE...AND MEAN LAYER RELATIVE HUMIDITY IS FORECAST TO DECREASE GRADUALLY DURING THE DAY ON BOTH THE NAM AND GFS AS PRECIPITABLE WATER VALUES ALSO SLOWLY FALL. IT SHOULD BE NOTED THAT WITH THE BETTER MID-LEVEL WINDS MOVING THROUGH EARLY THIS MORNING...THERE HAVE BEEN A COUPLE OF SHOWERS THAT HAVE DEVELOPED VERY BRIEFLY OVER UPSTATE SOUTH CAROLINA. WILL CERTAINLY MONITOR RADAR TRENDS...BUT FOR NOW THE FORECAST WILL ONLY SHOW A SLIGHT CHANCE OF A SHOWER ALONG AND EAST OF ABOUT U.S. 1 WITH A CHANCE OF A SHOWER OR THUNDERSTORM FROM INTERSTATE 95 EAST. 1000- 850MB THICKNESSES SUPPORT HIGHS IN THE UPPER 80S...AND WHEN MORNING CLOUDS ARE CONSIDERED...WILL FORECAST HIGHS IN THE MID TO UPPER 80S UNDER A NORTH-TO-NORTHEAST WIND 10 MPH OR LESS. && .SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/... AS OF 305 AM TUESDAY... BUFR SOUNDINGS ARE STABLE OVERNIGHT ON BOTH THE NAM AND THE GFS...WITH THE GFS IN PARTICULAR SHOWING A SMALL VOLUME OF MID-LEVEL MOISTURE AS THE TROUGH AXIS ALOFT MOVES THROUGH AND A WEAK MID-LEVEL SHORTWAVE FOLLOWS THE TROUGH AXIS OVERNIGHT IN THE NORTHWEST FLOW. THIS SHOULD TRANSLATE INTO A PERIOD OF SCATTERED MID-LEVEL CLOUDS... POSSIBLY BROKEN FOR A PERIOD IF THE GFS VERIFIES. LOW-LEVEL MOISTURE REMAINS BEST TOWARD INTERSTATE 95 AND MAY NOTE PATCHY FOG POSSIBLE IN THE GRIDDED AND WORDED FORECASTS FOR THOSE AREAS LATE TONIGHT INTO VERY EARLY WEDNESDAY. OVERNIGHT LOWS 65 TO 70. WEDNESDAY AND WEDNESDAY NIGHT...GFS BUFR SOUNDINGS ARE STABLE WEDNESDAY...WHILE THE NAM SHOWS MODEST INSTABILITY PARTICULARLY TOWARD KRWI AND KFAY. ALTHOUGH THE GFS POPS ARE LOW THROUGHOUT CENTRAL NORTH CAROLINA...ITS QPF DOES NOTE A MINOR HUNDREDTH OR SO TOWARD THE COASTAL PLAIN WEDNESDAY AFTERNOON. SURFACE DEW POINTS SHOULD GENERALLY MIX WELL BASED ON THE BUFR SOUNDINGS AND A DEVELOPING WESTERLY SURFACE FLOW...MIXING LAST TOWARD THE COASTAL PLAIN WHERE THE COMBINATION OF JUST ENOUGH INSTABILITY...WEAK 850MB CONVERGENCE AND GRADUALLY LOWERING DEW POINTS COULD RESULT IN A VERY ISOLATED SHOWER OR STORM. THE MEAN AIR MASS STARTS TO MOISTEN WEDNESDAY NIGHT WITH THE APPROACH OF THE SURFACE FRONT...BUT WITH ONLY WEAK MID-LEVEL SUPPORT AND JET DYNAMICS NORTH OF THE AREA IN VIRGINIA...WILL LEAN TOWARD THE GFS AS OPPOSED TO THE WET NAM AND SHOW A DRY OVERNIGHT WEDNESDAY WITH AN EXPECTED INCREASE IN MID- LEVEL CLOUDS OVER MUCH OF THE AREA. 1000-850MB THICKNESSES SUPPORT HIGHS OF A BLEND OF MAV AND MET MOS GUIDANCE...OR 90 TO 95. OVERNIGHT LOWS WEDNESDAY NIGHT WITHIN A DEGREE OR THREE OF 70. -DJF THU/THU NIGHT: AN UPPER LEVEL TROUGH OVER NEW ENGLAND WILL LIFT INTO THE CANADIAN MARITIMES THU/THU NIGHT...WITH A WEAKENED WNW FLOW ALOFT OVER THE CAROLINAS. SUBSIDENCE IN THE WAKE OF THE TROUGH WILL RESULT IN SFC PRESSURE RISES OVER THE OH VALLEY AND MID ATLANTIC...WITH AN ATTENDANT SFC RIDGE AXIS /BACKDOOR COLD FRONT/ EXTENDING SOUTHWARD THROUGH VA TOWARD THE NC BORDER LATE THU. UNCERTAINTY PERSISTS W/REGARD TO THE TIMING/PROGRESS OF THE BACK DOOR COLD FRONT...LENDING A FAIR AMOUNT OF UNCERTAINTY TO TEMPERATURES...ESP ALONG AND NORTH OF HWY 64. AT THIS TIME WILL INDICATE HIGHS RANGING FROM ~90F SOUTH TO 83-85F NEAR THE VA BORDER. DESTABILIZATION/FORCING WILL HIGHLY DEPEND ON BOTH THE EVOLUTION OF THE FRONT AND OF SMALL AMPLITUDE DISTURBANCES IN WNW FLOW ALOFT... WITH CONSIDERABLE UNCERTAINTY IN PRECIP CHANCES/COVERAGE. AT THIS TIME WILL INDICATE A SLIGHT CHANCE DURING THE LATE AFTERNOON/EVENING HOURS. -VINCENT && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 300 PM MONDAY... THE OVERALL PATTERN IS SIMILAR BETWEEN THE GFS AND ECMWF...BUT WITH DIFFERENCES IN THE DETAILS. INTO FRIDAY...BOTH THE GFS AND THE ECMWF FORECAST THE SURFACE FRONT MAINLY BEING JUST SOUTH OF CENTRAL NORTH CAROLINA. SURFACE HIGH PRESSURE EDGES IN FROM THE NORTH PARTICULARLY ON THE GFS...BUT THE GFS GENERATES MUCH MORE QPF THROUGHOUT CENTRAL NORTH CAROLINA DUE TO THE 850MB FRONT BEING FARTHER NORTH WITH MUCH MORE MOISTURE ADVECTION AND 850MB CONVERGENCE ACROSS CENTRAL NORTH CAROLINA AS COMPARED TO THE ECMWF. THAT LATTER MODEL HAS THE BEST MOISTURE CONVERGENCE FARTHER SOUTH AND CLOSER TO THE SURFACE FRONT...AND NEARER ANY WAVES THAT MAY MOVE ALONG THE SURFACE FRONT. THE UPPER FLOW...INCLUDING A RIDGE AXIS TO OUR WEST...IS CONFLUENT AND FOR THIS PART OF THE FORECAST WILL LEAN MORE TOWARD THE ECMWF AND THE SURFACE PATTERN. THE FORECAST RESULT WILL BE HIGHER CHANCES FOR PRECIPITATION GENERALLY ALONG AND SOUTH OF U.S. 64...HIGHEST OVER THE SOUTHWEST PIEDMONT...WITH THE LEAST CHANCES OVER THE NORTHERN COASTAL PLAIN. WILL MAINTAIN THE CHANCE FOR THUNDER FRIDAY INTO FRIDAY NIGHT WHERE IT IS CURRENTLY FORECAST...BUT COARSE MODEL SOUNDINGS PARTICULARLY ON THE ECMWF TEND TO FAVOR LIMITED INSTABILITY AND THUNDER MAY BE SOMEWHAT ISOLATED. IF THE COARSE SOUNDINGS ARE CORRECT...WITH HIGH PRESSURE TRYING TO BUILD IN NORTH OF THE SURFACE FRONT...SATURDAY AT LEAST THROUGH MUCH OF THE MORNING COULD BE QUITE MURKY WITH LOW CLOUDS IN MANY AREAS. THE SURFACE FRONT MOVES LITTLE AND THE ORIENTATION OF THE CHANCES OF PRECIPITATION WILL CONTINUE THROUGH SATURDAY NIGHT SIMILAR TO FRIDAY. BOTH THE GFS AND THE ECMWF HAVE LIMITED QPF IN THE NORTHEAST PIEDMONT AND NORTHERN COASTAL PLAIN AND THIS MAY EVENTUALLY VERIFY...BUT FOR THIS FORECAST WILL CONTINUE A SLIGHT CHANCE THERE DUE TO TIMING AND FEATURE LOCATION UNCERTAINTIES. INSTABILITY CONTINUES TO BE LIMITED AND WILL NOTE A SLIGHT CHANCE OF THUNDER FOR THE DAY SATURDAY CLOSER TO THE SURFACE BOUNDARY AND BETTER LIFT...SOUTH OF A LINE FROM ABOUT KINT TO KGSB. THE APPROACH AND PASSAGE OF A WEAK MID-LEVEL LOW ON THE ECMWF...AND A MODERATELY-STRONG MID-LEVEL SHORTWAVE ON THE GFS...RESULT IN INCREASING CHANCES FOR PRECIPITATION THROUGHOUT CENTRAL NORTH CAROLINA SUNDAY. WHILE THERE ARE SOME TIMING...LOCATION...AND STRENGTH DIFFERENCES BETWEEN THE GFS AND ECMWF...THE STRENGTHENING MID-LEVEL FEATURE TRANSLATES INTO A STRENGTHENING SURFACE WAVE SUNDAY AND SUNDAY NIGHT. THIS COULD RESULT IN A FAIRLY RAINY DAY INTO AT LEAST THE OVERNIGHT HOURS OF SUNDAY FOR A GOOD PORTION OF CENTRAL NORTH CAROLINA SOUTH OF U.S. 64. WILL NOT MENTION LIKELY CHANCES THERE THIS FAR OUT BUT THIS FORECAST WILL SHOW SOLIDLY HIGH CHANCES SUNDAY INTO SUNDAY NIGHT...BEFORE DRYING AND SUBSIDENCE... AT LEAST BRIEFLY...OCCUR BEHIND THE MID-LEVEL WAVE OR WEAK SURFACE LOW FROM WEST-TO-EAST MONDAY INTO MONDAY NIGHT. HIGH TEMPERATURES ARE A CHALLENGE...WITH CONCERNS ABOUT HOW WARM CONDITIONS WILL BECOME DUE TO THE PROXIMITY OF THE FRONT...THE ASSOCIATED CLOUD COVER...AND THE THREAT OF PRECIPITATION. SOME OF THE GRIDDED GUIDANCE FOR THE HIGHS DIFFER BY OVER 15 DEGREES...BUT IT IS INTERESTING...FOR EXAMPLE...HOW CONSISTENT RAW GFS AND ECMWF GRIDDED HIGH TEMPERATURE GUIDANCE IS FOR SUNDAY...KEEPING HIGHS ONLY IN THE 70S OVER MUCH OF THE AREA SOUTH OF U.S. 64 AND IN THE TRIAD...WARMING TO AROUND 80 NORTH OF THE TRIANGLE. WHILE OVERNIGHT LOWS SHOULD BE IN THE 60S...HIGH TEMPERATURES FORECAST WILL BE BELOW NORMAL AND MAINLY FROM THE MID 70S TO LOWER 80S EACH DAY...MOSTLY 80 TO 85 MONDAY IN THE EXPECTED DEVELOPING DRYING AND SUBSIDENCE. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... AS OF 155 AM TUESDAY... PATCHY MVFR AND IFR CONDITIONS IN FOG AND LOW CLOUDS WILL CONTINUE OVER CENTRAL NORTH CAROLINA DURING THE EARLY MORNING. THE LATEST SATELLITE IMAGES COMBINED WITH OBSERVATIONS SHOWED SOME LOWER CLOUDS TRYING TO MOVE TOWARD KINT...WITH A FEW LOW CLOUDS VISIBLE UNDERNEATH HIGHER CLOUDS IN THE SOUTHWEST FLOW ALOFT. FOG HAS BEEN DIFFICULT TO DEVELOP DUE TO THE MID- AND HIGH-LEVEL CLOUDS...AND THIS LIKELY WILL CONTINUE DURING THE REST OF THE MORNING. LIGHT FOG SEEMS REASONABLE...WITH THE HRRR WRF MODEL SHOWING THE BEST POTENTIAL FOR SOLID IFR FOG DEVELOPMENT ORIGINATING OVER SOUTHERN VIRGINIA WHERE THERE ARE FEWER MID- AND HIGH-LEVEL CLOUDS...THEN MOVING SOUTH-SOUTHWEST IN THE LIGHT LOW-LEVEL FLOW FROM ABOUT 07Z TO 12Z. THIS SEEMS A PLAUSIBLE SCENARIO...AND HAVE ACCOUNTED FOR THIS IN THE TAFS WITH THE LOWEST VISIBLITY FOR A PERIOD DURING THE EARLY MORNING AT KRWI AND KRDU. AS LOW PRESSURE MOVES NORTHEAST OFF OF THE CAROLINA COAST THERE IS AN OUTSIDE CHANCE OF A SHOWER MAINLY ALONG AND EAST OF INTERSTATE 95...BUT THE CHANCES SEEM TOO LOW TO INCLUDE IN A TAF POINT FORECAST. VFR CONDITIONS SHOULD PREVAIL OVER CENTRAL NORTH CAROLINA BY AFTERNOON UNDER A NORTHEAST WIND. EVENING WINDS... LIGHT AND VARIABLE...MAY SHOW A TENDENCY TO BECOME LIGHT SOUTHERLY BY THE END OF THE 06Z VALID TAF PERIOD. BEYOND THE 06Z VALID TAF PERIOD...PATCHY FOG AND SUB-VFR CONDITIONS ARE POSSIBLE LATE TONIGHT INTO EARLY WEDNESDAY...WITH THE BETTER CHANCES OF SUCH TOWARD KFAY AND KRWI. BEHIND A COLD FRONT WHICH SETTLES JUST SOUTH OF THE AREA BY LATE THURSDAY...CHANCES FOR PRECIPITATION WILL INCREASE. INTO SATURDAY...THE HIGHER CHANCES AS THEY DEVELOP ARE EXPECTED TO BE OVER THE SOUTHWEST PIEDMONT INTO THE SANDHILLS. STILL...AREAS OF SUB-VFR CONDITIONS IN LOWER CLOUDS ARE POSSIBLE THROUGHOUT MUCH OF CENTRAL NORTH CAROLINA DEVELOPING SATURDAY OR ESPECIALLY SATURDAY NIGHT. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DJF NEAR TERM...DJF SHORT TERM...DJF/VINCENT LONG TERM...DJF AVIATION...DJF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
155 AM EDT TUE AUG 5 2014 .SYNOPSIS...LOW PRESSURE MOVES NORTHEAST JUST OFF OF THE CAROLINA COAST TODAY THROUGH THIS EVENING. WEAK HIGH PRESSURE WILL BE LOCATED OVER THE APPALACHIANS. A COLD FRONT MOVES SOUTH OVER THE REGION WEDNESDAY AFTERNOON INTO THURSDAY. && .NEAR TERM /THROUGH TUESDAY NIGHT/... AS OF 948 PM MONDAY... THE MAIN FORECAST PROBLEM OF THE NIGHT WILL AGAIN BE THE STATUS/FOG DEVELOPMENT. THE CURRENT DEW POINTS WERE IN THE MID 60S NW... AND 70+ IN THE SOUTH AND EAST. THE SKIES WERE MOSTLY CLEAR TO PARTLY CLOUDY. IT DOES APPEAR... BASED ON SATELLITE DATA... THAT THE VEIL OF HIGH CLOUDINESS THAT HAD BEEN DENSE EARLIER AS FAR WEST AS FAY AND RDU... WILL CONTINUE TO SHIFT AWAY OVERNIGHT. WITH WINDS NEARLY CALM UNDER WEAK RIDGING... THIS SHOULD ALLOW PLENTY OF OPPORTUNITY FOR COOLING TO THE SATURATION POINT... ESPECIALLY SE OF THE TRIAD REGION BETWEEN 06Z-12Z. WE WILL ADD AREAS OF FOG IN ALL BUT THE TRIAD... AND PLACE PATCHY FOG OVER IN THAT REGION. OTHERWISE... NO OTHER CHANGES WITH LOWS GENERALLY 65-70. CYCLONIC FLOW ALOFT WILL PERSIST OVER THE AREA ON TUESDAY...ALTHOUGH THE UPPER LEVEL TROUGH TO OUR WEST WILL BEGIN TO WEAKEN AND DEAMPLIFY AS IT SHIFTS EAST. IN ADDITION...THE STATIONARY FRONT WILL STILL BE NEAR/ALONG THE COAST. AS A RESULT...THE BEST PRECIP CHANCES WILL BE ACROSS THES EASTERN PORTIONS OF THE FORECAST AREA ONCE AGAIN. MOSTLY DRY CONDITIONS ARE EXPECTED ACROSS THE WEST AS SLIGHTLY DRIER AIR MOVES IN COURTESY OF THE FLOW ALOFT BECOMING MORE WEST/NORTHWESTERLY ASSOCIATED WITH THE EASTWARD PROGRESSION OF THE UPPER LEVEL TROUGH. THICKNESS VALUES ARE PROGGED TO INCREASE OVER TODAYS VALUES...WHICH SUPPORTS TEMPS CLIMBING INTO THE UPPER 80S. OVERNIGHT LOWS WILL ONCE AGAIN BE IN THE MID/UPPER 60S. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY/... AS OF 315 PM MONDAY... WEDNESDAY THROUGH THURSDAY: EASTERN US TROUGH WILL PERSIST THROUGH THE PERIOD...ALBEIT UNDER WEAKENING INFLUENCE ACROSS THE SOUTHERN LATITUDES WITH INCREASINGLY WEST-NORTHWESTERLY FLOW ALOFT. SHORTWAVE TROUGH TRAVERSING THE NORTHERN MID-ATLANTIC STATES WILL HELP TO PROPEL A COLD FRONT SOUTHWARD INTO THE AREA LATE WEDNESDAY/WEDNESDAY NIGHT. PRECIP/RAIN CHANCES ALONG THE FRONT LATE WEDNESDAY-WEDNESDAY NIGHT WILL BE RATHER SCARCE...LIMITED BY THE W-NWLY DOWNSLOPE FLOW IN PLACE WHILE ANY APPRECIABLE SHORTWAVE DYNAMICS REMAINS NORTH OF THE AREA. ALL OF THIS WHILE MOVING INTO THE AREA DURING POOR DIURNAL TIMING WHICH IS FURTHER EXACERBATED BY THE PRESENCE OF A CAPPING INVERSION ALOFT IN ADVANCE OF THE FRONT WEDNESDAY AFTERNOON. INSTEAD...THE BETTER RAIN CHANCES LOOK TO BE DELAYED UNTIL LATE THURSDAY AFTERNOON/THURSDAY EVENING...MAINLY ACROSS THE SOUTHERN TIER WHERE DISTURBANCES EMBEDDED IN THE NWLY FLOW ALOFT LOOK TO INTERCEPT THE LINGERING FRONT ZONE. TEMPERATURES... WEDNESDAY WILL BE THE HOTTEST DAY OF THE WEEK WITH LOW-LEVEL THICKNESSES PROJECTED AOA 15-20 METERS ABOVE NORMAL... WHICH SHOULD EASILY SUPPORT HIGHS IN THE LOWER TO MID 90S. LOWS WEDNESDAY NIGHT IN THE MID 60S TO LOWER 70S SOUTH. AS FRONT SLIPS SLOWLY SOUTH THROUGH THE AREA ON WEDNESDAY NIGHT/EARLY THURSDAY...HIGHS THURSDAY WILL COOL OFF A GOOD BIT...ESPECIALLY ACROSS THE NORTHERN TIER. HIGHS THURSDAY RANGING FROM MID 80S NORTH TO AROUND 90 SOUTH. LOWS && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... AS OF 300 PM MONDAY... THE OVERALL PATTERN IS SIMILAR BETWEEN THE GFS AND ECMWF...BUT WITH DIFFERENCES IN THE DETAILS. ON THURSDAY NIGHT INTO FRIDAY...BOTH THE GFS AND THE ECMWF FORECAST THE SURFACE FRONT MAINLY BEING JUST SOUTH OF CENTRAL NORTH CAROLINA. SURFACE HIGH PRESSURE EDGES IN FROM THE NORTH PARTICULARLY ON THE GFS...BUT THE GFS GENERATES MUCH MORE QPF THROUGHOUT CENTRAL NORTH CAROLINA DUE TO THE 850MB FRONT BEING FARTHER NORTH WITH MUCH MORE MOISTURE ADVECTION AND 850MB CONVERGENCE ACROSS CENTRAL NORTH CAROLINA AS COMPARED TO THE ECMWF. THAT LATTER MODEL HAS THE BEST MOISTURE CONVERGENCE FARTHER SOUTH AND CLOSER TO THE SURFACE FRONT...AND NEARER ANY WAVES THAT MAY MOVE ALONG THE SURFACE FRONT. THE UPPER FLOW...INCLUDING A RIDGE AXIS TO OUR WEST...IS CONFLUENT AND FOR THIS PART OF THE FORECAST WILL LEAN MORE TOWARD THE ECMWF AND THE SURFACE PATTERN. THE FORECAST RESULT WILL BE HIGHER CHANCES FOR PRECIPITATION GENERALLY ALONG AND SOUTH OF U.S. 64...HIGHEST OVER THE SOUTHWEST PIEDMONT...WITH THE LEAST CHANCES OVER THE NORTHERN COASTAL PLAIN. WILL MAINTAIN THE CHANCE FOR THUNDER FRIDAY INTO FRIDAY NIGHT WHERE IT IS CURRENTLY FORECAST...BUT COARSE MODEL SOUNDINGS PARTICULARLY ON THE ECMWF TEND TO FAVOR LIMITED INSTABILITY AND THUNDER MAY BE SOMEWHAT ISOLATED. IF THE COARSE SOUNDINGS ARE CORRECT...WITH HIGH PRESSURE TRYING TO BUILD IN NORTH OF THE SURFACE FRONT...SATURDAY AT LEAST THROUGH MUCH OF THE MORNING COULD BE QUITE MURKY WITH LOW CLOUDS IN MANY AREAS. THE SURFACE FRONT MOVES LITTLE AND THE ORIENTATION OF THE CHANCES OF PRECIPITATION WILL CONTINUE THROUGH SATURDAY NIGHT SIMILAR TO FRIDAY. BOTH THE GFS AND THE ECMWF HAVE LIMITED QPF IN THE NORTHEAST PIEDMONT AND NORTHERN COASTAL PLAIN AND THIS MAY EVENTUALLY VERIFY...BUT FOR THIS FORECAST WILL CONTINUE A SLIGHT CHANCE THERE DUE TO TIMING AND FEATURE LOCATION UNCERTAINTIES. INSTABILITY CONTINUES TO BE LIMITED AND WILL NOTE A SLIGHT CHANCE OF THUNDER FOR THE DAY SATURDAY CLOSER TO THE SURFACE BOUNDARY AND BETTER LIFT...SOUTH OF A LINE FROM ABOUT KINT TO KGSB. THE APPROACH AND PASSAGE OF A WEAK MID-LEVEL LOW ON THE ECMWF...AND A MODERATELY-STRONG MID-LEVEL SHORTWAVE ON THE GFS...RESULT IN INCREASING CHANCES FOR PRECIPITATION THROUGHOUT CENTRAL NORTH CAROLINA SUNDAY. WHILE THERE ARE SOME TIMING...LOCATION...AND STRENGTH DIFFERENCES BETWEEN THE GFS AND ECMWF...THE STRENGTHENING MID-LEVEL FEATURE TRANSLATES INTO A STRENGTHENING SURFACE WAVE SUNDAY AND SUNDAY NIGHT. THIS COULD RESULT IN A FAIRLY RAINY DAY INTO AT LEAST THE OVERNIGHT HOURS OF SUNDAY FOR A GOOD PORTION OF CENTRAL NORTH CAROLINA SOUTH OF U.S. 64. WILL NOT MENTION LIKELY CHANCES THERE THIS FAR OUT BUT THIS FORECAST WILL SHOW SOLIDLY HIGH CHANCES SUNDAY INTO SUNDAY NIGHT...BEFORE DRYING AND SUBSIDENCE... AT LEAST BRIEFLY...OCCUR BEHIND THE MID-LEVEL WAVE OR WEAK SURFACE LOW FROM WEST-TO-EAST MONDAY INTO MONDAY NIGHT. HIGH TEMPERATURES ARE A CHALLENGE...WITH CONCERNS ABOUT HOW WARM CONDITIONS WILL BECOME DUE TO THE PROXIMITY OF THE FRONT...THE ASSOCIATED CLOUD COVER...AND THE THREAT OF PRECIPITATION. SOME OF THE GRIDDED GUIDANCE FOR THE HIGHS DIFFER BY OVER 15 DEGREES...BUT IT IS INTERESTING...FOR EXAMPLE...HOW CONSISTENT RAW GFS AND ECMWF GRIDDED HIGH TEMPERATURE GUIDANCE IS FOR SUNDAY...KEEPING HIGHS ONLY IN THE 70S OVER MUCH OF THE AREA SOUTH OF U.S. 64 AND IN THE TRIAD...WARMING TO AROUND 80 NORTH OF THE TRIANGLE. WHILE OVERNIGHT LOWS SHOULD BE IN THE 60S...HIGH TEMPERATURES FORECAST WILL BE BELOW NORMAL AND MAINLY FROM THE MID 70S TO LOWER 80S EACH DAY...MOSTLY 80 TO 85 MONDAY IN THE EXPECTED DEVELOPING DRYING AND SUBSIDENCE. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... AS OF 155 AM TUESDAY... PATCHY MVFR AND IFR CONDITIONS IN FOG AND LOW CLOUDS WILL CONTINUE OVER CENTRAL NORTH CAROLINA DURING THE EARLY MORNING. THE LATEST SATELLITE IMAGES COMBINED WITH OBSERVATIONS SHOWED SOME LOWER CLOUDS TRYING TO MOVE TOWARD KINT...WITH A FEW LOW CLOUDS VISIBLE UNDERNEATH HIGHER CLOUDS IN THE SOUTHWEST FLOW ALOFT. FOG HAS BEEN DIFFICULT TO DEVELOP DUE TO THE MID- AND HIGH-LEVEL CLOUDS...AND THIS LIKELY WILL CONTINUE DURING THE REST OF THE MORNING. LIGHT FOG SEEMS REASONABLE...WITH THE HRRR WRF MODEL SHOWING THE BEST POTENTIAL FOR SOLID IFR FOG DEVELOPMENT ORIGINATING OVER SOUTHERN VIRGINIA WHERE THERE ARE FEWER MID- AND HIGH-LEVEL CLOUDS...THEN MOVING SOUTH-SOUTHWEST IN THE LIGHT LOW-LEVEL FLOW FROM ABOUT 07Z TO 12Z. THIS SEEMS A PLAUSIBLE SCENARIO...AND HAVE ACCOUNTED FOR THIS IN THE TAFS WITH THE LOWEST VISIBLITY FOR A PERIOD DURING THE EARLY MORNING AT KRWI AND KRDU. AS LOW PRESSURE MOVES NORTHEAST OFF OF THE CAROLINA COAST THERE IS AN OUTSIDE CHANCE OF A SHOWER MAINLY ALONG AND EAST OF INTERSTATE 95...BUT THE CHANCES SEEM TOO LOW TO INCLUDE IN A TAF POINT FORECAST. VFR CONDITIONS SHOULD PREVAIL OVER CENTRAL NORTH CAROLINA BY AFTERNOON UNDER A NORTHEAST WIND. EVENING WINDS... LIGHT AND VARIABLE...MAY SHOW A TENDENCY TO BECOME LIGHT SOUTHERLY BY THE END OF THE 06Z VALID TAF PERIOD. BEYOND THE 06Z VALID TAF PERIOD...PATCHY FOG AND SUB-VFR CONDITIONS ARE POSSIBLE LATE TONIGHT INTO EARLY WEDNESDAY...WITH THE BETTER CHANCES OF SUCH TOWARD KFAY AND KRWI. BEHIND A COLD FRONT WHICH SETTLES JUST SOUTH OF THE AREA BY LATE THURSDAY...CHANCES FOR PRECIPITATION WILL INCREASE. INTO SATURDAY...THE HIGHER CHANCES AS THEY DEVELOP ARE EXPECTED TO BE OVER THE SOUTHWEST PIEDMONT INTO THE SANDHILLS. STILL...AREAS OF SUB-VFR CONDITIONS IN LOWER CLOUDS ARE POSSIBLE THROUGHOUT MUCH OF CENTRAL NORTH CAROLINA DEVELOPING SATURDAY OR ESPECIALLY SATURDAY NIGHT. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DJF NEAR TERM...PWB/KRD SHORT TERM...CBL LONG TERM...DJF AVIATION...DJF
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
303 AM EDT TUE AUG 5 2014 .SYNOPSIS... A WEAK COLD FRONT NEAR LAKE ERIE WILL PUSH SOUTH ACROSS THE AREA TODAY. HIGH PRESSURE WILL PUSH SOUTHEAST OVER THE REGION BY THURSDAY...AND REMAIN OVER THE AREA THROUGH THE WEEKEND. && .NEAR TERM /UNTIL 6 PM TUESDAY EVENING/... FIRST IN A SERIES OF TWO S/W TROUGHS WILL MOVE SE ACROSS THE AREA TODAY INDUCING A SURFACE TROUGH NEAR LERI TO MOVE SOUTH OF THE CWA BY TONIGHT. NEITHER THE SHEAR OR INSTABILITY ARE REAL IMPRESSIVE SO GENERALLY NOT EXPECTING MUCH IN THE WAY OF SEVERE STORMS. THE CONVECTION WILL TEND TO SHIFT SOUTH WITH THE TROUGH BUT ALSO TEND TO LINGER ON THE BACK EDGE AS THE MOISTURE HANGS BACK IN RESPONSE TO LIGHT WINDS DOING LITTLE TO FLUSH OUT THE LOW LEVEL MOISTURE. TEMPS TODAY WILL BE A LITTLE COOLER THAN YDAY DUE TO THE ADDED CLOUDS AND WINDS SHIFTING MORE TO THE NORTH. && .SHORT TERM /6 PM TUESDAY EVENING THROUGH FRIDAY NIGHT/... LINGERING MOISTURE AND UPPER TROUGHING SHOULD KEEP A THREAT FOR SHRA AND SOME THUNDER GOING TONIGHT FOR MOST OF THE AREA. THE SECOND S/W WILL DROP SE THRU THE REGION WED HELPING TO INDUCE CONVECTION. HOWEVER...LOW LEVEL FLOW WILL BE MAINLY N TO NE WHICH WILL LIMIT CONVERGENCE SO WILL PROBABLY JUST SEE SCATTERED COVERAGE WITH THE BETTER CHANCE PROBABLY OVER THE SOUTH HALF OF THE CWA. ONCE AGAIN...CONVECTIVE PARAMETERS ARE NOT OVERLY STRONG SO NO ORGANIZED SEVERE STORMS LOOK LIKELY. TEMPS WED SHOULD BE SIMILAR TO TUE AS NO SIGNIFICANT AIRMASS CHANGE HAS TAKEN PLACE. DRIER AIR SLOWLY FILTERS SOUTH INTO THE AREA WED NIGHT WHICH SHOULD SHIFT THE THREAT OF PRECIP SOUTH SO THINK THE RAIN SHOULD BE DONE THROUGHOUT THE CWA BY ABOUT MIDNIGHT WED NIGHT. TEMPS WED NIGHT SHOULD GET INTO A 55 TO 60 RANGE FOR MOST PLACES AS LIGHT N TO NE WINDS PERSIST AND CLOUDS DECREASE. THE NAM REMAINS CONSISTENT IN DEVELOPING A CONVECTIVE COMPLEX ON THE NE SIDE OF A LOW WED NIGHT IN IA AND MOVING THE COMPLEX ESE TO CROSS THE SW PART OF THE CWA LATE THU/THU NIGHT. NOT SEEING THIS ON OTHER MODELS ALTHOUGH THE GFS HAS INCHED SOME QPF INTO SW OH THU NIGHT. WILL MAINLY KEEP FORECAST DRY THU/THU NIGHT BUT WILL ALLOW FOR MORE CLOUDINESS OVER THE SW AND INTRODUCE A SLIGHT CHANCE POP. DAYTIME TEMPS THU AND FRI SHOULD BE PLEASANT WITH HIGHS MOSTLY IN THE MID TO UPPER 70S AND LOWS THU NIGHT IN THE 50S. && .LONG TERM /SATURDAY THROUGH MONDAY/... THE MODELS ARE NOT IN AGREEMENT WITH THIS PORTION OF THE FORECAST. THE 00Z GFS...00Z ECMWF AND CANADIAN MODEL SEEM TO HAVE THE SAME SURFACE AND UPPER AIR FEATURES...HOWEVER...THE ECMWF IS MUCH DRIER OVER THE WEEKEND AND THEN BY MONDAY IT HAS MORE MOISTURE TO SUPPORT SOME SHOWERS AND THUNDERSTORMS. EVEN OVER THE WEEKEND WITH HIGH PRESSURE TO THE NORTH OF THE FORECAST AREA...LOW PRESSURE IS OVER THE OHIO VALLEY AND SOME PRECIPITATION IS JUST SOUTH OF THE FORECAST AREA. AT THIS TIME KEPT THE WEEKEND DRY AND WENT WITH 20 POPS FOR MONDAY. TEMPERATURES WILL BE NEAR NORMAL. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... A WEAK COLD FRONT WILL BE MOVING FROM NORTH TO SOUTH TODAY...THE FRONT SHOULD BE SOUTH OF THE FORECAST AREA AROUND DARK. THE FRONT WILL MOVE THROUGH SLOWLY. THE TIMING OF THE SHOWERS AND THUNDERSTORMS IS NOT CLEAR CUT. A BATCH OF SHOWERS AND THUNDERSTORMS OVER NORTHWEST INDIANA WILL DECREASE AS THEY MOVE EAST...SOME SHOWERS COULD GET INTO NW OHIO AFTER DAYBREAK AND THEN CONTINUE TO WEAKEN AS THEY MOVE EAST. GOING ALONG WITH THE HRRR MODEL IN DEVELOPING SHOWERS AND THUNDERSTORMS EARLY IN THE AFTERNOON. MVFR OR IFR VISIBILITIES IN THE HEAVIER STORMS. OUTLOOK...NON VFR IN AREAS OF FOG WEDNESDAY MORNING. && .MARINE... A WEAK COLD FRONT WILL BE MOVING ACROSS LAKE ERIE FROM THE NORTH TODAY. SOME THUNDERSTORMS COULD OCCUR OVER THE LAKE...IT IS POSSIBLE THAT SOME OF THEM COULD PROMPT THE NEED FOR A SPECIAL MARINE WARNING. OTHERWISE BEHIND THE FRONT THE WINDS WILL BE FROM A NORTHERLY DIRECTION AS HIGH PRESSURE BUILDS IN FROM THE NORTHWEST. THE HIGH WILL SHIFT EAST OF LAKE ERIE FOR THE WEEKEND WITH THE WINDS BECOMING SOUTHERLY. IN THE MEANTIME NOT EXPECTING THE WINDS TO BE STRONG ENOUGH TO CAUSE 3 TO 5 FOOT WAVES...BUT THIS WILL HAVE TO BE MONITORED AS THAT DIRECTION CAN BE TRICKY. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...ADAMS NEAR TERM...ADAMS SHORT TERM...ADAMS LONG TERM...KIELTYKA AVIATION...KIELTYKA MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
153 AM EDT TUE AUG 5 2014 .SYNOPSIS... A WEAK COLD FRONT WILL PUSH ACROSS THE AREA TUESDAY. HIGH PRESSURE WILL PUSH SOUTHEAST OVER THE AREA BY THURSDAY...AND REMAIN OVER THE AREA INTO THE WEEKEND. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... COLD FRONT CURRENTLY INTO CENTRAL MICHIGAN. DRY FOR A MAJORITY IF NOT ALL OF THE NIGHT...BUT ISOLATED/SCATTERED TSRA MAY BE NEARING TOLEDO AND THE LAKE NEAR 6 AM. WITH CLOUDS MOVING OVER THE AREA AHEAD OF CONVECTION EXPECT OVERNIGHT LOWS WARMER THAN LAST NIGHT. LEANED TOWARD THE SLIGHTLY WARMER METMOS. ADJUSTED THE HOURLY TEMPERATURES FOR THE REMINDER OF THE NIGHT WITH THIS EVENING UPDATE. && .SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/... MODELS IN REASONABLE AGREEMENT MOVING THE COLD FRONT ACROSS THE FORECAST AREA TUESDAY INTO TUESDAY NIGHT...REACHING THE OHIO DURING THE DAY ON WEDNESDAY. COULD WELL BE A LULL IN CONVECTION TUESDAY NIGHT WITH A SECOND ROUND OF CONVECTION ON WEDNESDAY AS A SHORT WAVE MOVES ACROSS THE FORECAST AREA. UNFORTUNATELY MODELS NOT IN GOOD AGREEMENT ON EXACT TRACK AND TIMING OF SHORT WAVE. SO FOR NOW WILL JUST CONTINUE WITH CHANCE POPS WEDNESDAY. MODELS ALSO IN GOOD AGREEMENT WITH LARGE AREA OF CANADIAN HIGH PRESSURE CENTERED OVER THE CENTRAL LAKES BY DAYBREAK THURSDAY. TREND AFTER THAT IS A RETURN OF DRIER AND COOLER CONDITIONS. && .LONG TERM /FRIDAY THROUGH MONDAY/... HIGH PRESSURE WILL SETTLE INTO SOUTHERN ONTARIO FOR THE LONG TERM FORECAST PERIOD. THIS WILL KEEP LOW PRESSURE NEAR OR SOUTH OF THE OHIO RIVER WHICH MEANS DRY WEATHER THROUGH THE PERIOD. HIGHS WILL REMAIN NEAR SEASONAL AVERAGES THAT ARE AROUND 80 DEGREES. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... A WEAK COLD FRONT WILL BE MOVING FROM NORTH TO SOUTH TODAY...THE FRONT SHOULD BE SOUTH OF THE FORECAST AREA AROUND DARK. THE FRONT WILL MOVE THROUGH SLOWLY. THE TIMING OF THE SHOWERS AND THUNDERSTORMS IS NOT CLEAR CUT. A BATCH OF SHOWERS AND THUNDERSTORMS OVER NORTHWEST INDIANA WILL DECREASE AS THEY MOVE EAST...SOME SHOWERS COULD GET INTO NW OHIO AFTER DAYBREAK AND THEN CONTINUE TO WEAKEN AS THEY MOVE EAST. GOING ALONG WITH THE HRRR MODEL IN DEVELOPING SHOWERS AND THUNDERSTORMS EARLY IN THE AFTERNOON. MVFR OR IFR VISIBILITIES IN THE HEAVIER STORMS. OUTLOOK...NON VFR IN AREAS OF FOG WEDNESDAY MORNING. && .MARINE... A WEAK COLD FRONT WILL CROSS LAKE ERIE ON TUESDAY WITH HIGH PRESSURE GRADUALLY BUILDING ACROSS THE LAKE INTO THURSDAY. THE HIGH WILL THEN TAKE UP RESIDENCE OVER SOUTHERN ONTARIO FOR THE WEEKEND. SO AFTER A BRIEF PERIOD OF NORTHWESTERLY WINDS THEY WILL SWING AROUND TO THE NORTH AND NORTHEAST FOR THE END OF THE WEEK INTO THE WEEKEND. WINDS WILL REMAIN LIGHT 10 KNOTS OR LESS THROUGH THE FORECAST. THE NORTHWEST WINDS TUESDAY AFTERNOON INTO WEDNESDAY MAY BRIEF BRING WAVES INTO THE 2 TO 3 FOOT RANGE. OTHERWISE 2 FEET OR LESS WILL BE EXPECTED. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...DJB NEAR TERM...DJB/OUDEMAN SHORT TERM...DJB LONG TERM...MULLEN AVIATION...KIELTYKA MARINE...MULLEN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
514 AM EDT TUE AUG 5 2014 .SYNOPSIS... A RIDGE OF HIGH PRESSURE AND RELATIVELY DRY AIR WILL COVER CENTRAL AND SOUTHEASTERN PENNSYLVANIA THIS MORNING. A COLD FRONT WILL PUSH SOUTHEAST ACROSS THE STATE THIS AFTERNOON AND EVENING. A SURGE OF COOLER...DRIER AIR AND SHARPENING OF THE UPPER TROUGH WILL PUSH A STRONGER COLD FRONT ACROSS THE COMMONWEALTH WEDNESDAY. COMFORTABLE HUMIDITY AND NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES WILL FOLLOW FOR LATE WEDNESDAY INTO THIS UPCOMING WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... SURFACE HIGH PRESSURE RIDGE STRETCHED SW TO NE ACROSS THE CWA WILL MAINTAIN CLEAR SKIES AND NEARLY CALM AIR FOR THE REST OF THE OVERNIGHT HOURS. THE CURRENT TIGHT...ZERO - 3 DEG F TEMP/DEWPOINT SPREAD AND AN AIR TO RIVER/STREAM TEMP DIFF OF AROUND 20F WILL LEAD TO PATCHY VALLEY FOG FOR SEVERAL HOURS LEADING UP TO...AND SHORTLY AFTER SUNRISE. VSBYS IN THE DEEPEST/COOLEST VALLEYS OF NRN PENN COULD DIP BRIEFLY BELOW 1/4SM THROUGH 12Z. LOW TEMPS THIS MORNING WILL RANGE FROM THE MID 50S IN THE COOLER NORTHERN AND WESTERN MTN VALLEYS...TO THE LOWER 60S IN THE SOUTHEAST METRO AREAS. QUASI-STNRY/RELATIVELY WEAK SFC FRONT EXTENDED FROM GRAND RAPIDS MICHIGAN...TO NEAR THE NORTH SHORE OF LAKE ERIE AT 08Z. ABUNDANT SUNSHINE WILL OCCUR THIS MORNING ACROSS THE LAUREL HIGHLANDS...CENTRAL MTNS...LYCOMING VALLEY AND NCENT MTNS BEFORE CLOUDS AND SCATTERED SHRA/TSRA ENCROACH FROM THE NW THIS AFTERNOON. THE LOWER SUSQ VALLEY SHOULD BASK IN MOSTLY SUNNY CONDITIONS WITH RELATIVELY COMFORTABLE HUMIDITY...THANKS TO THE SFC RIDGE AND NEAR TO SLIGHTLY BELOW NORMAL PWAT LINGERING THERE UNTIL 00Z WED. THE LATEST HRRR AND WRF ARW WERE BLENDED WITH THE 03Z SREF TO PAINT TIMING AND AREAL COVERAGE DETAILS INTO OUR POP AND WEATHER GRID DATABASE FOR THE ANTICIPATED SHOWERS AND SCATTERED TSRA THAT WILL IMPACT MAINLY THE NW HALF OF THE CWA DURING THE MIDDAY AND AFTERNOON HOURS TODAY. THE FRONTAL BOUNDARY WILL GRADUALLY WEAKEN AND SLOW AS IT EDGES TWD THE LAURELS AND LOWER SUSQ VALLEY TONIGHT...WITH ISOLATED TO WIDELY SCATTERED TSRA DRIFTING INTO THAT REGION LATER THIS EVENING. MU CAPES WILL INCREASE TO BETWEEN 800-1200 J/KG IN MOST PLACES BETWEEN 16-20Z...WITH A POCKET OF 1500 J/KG CAPE PRECEDING THE AREA OF MOST NUMEROUS SHRA/TSRA ACROSS THE NW AND NCENT MTNS LATE THIS AFTERNOON AND EARLY THIS EVENING. BASIN AVERAGE RAINFALL ENDING AT 00Z WED RANGE FROM ONE-TENTH...TO ONE-QUARTER OF AN INCH ACROSS THE NRN MTNS...TO JUST A FEW HUNDREDTHS AT BEST IN THE FAR SE. CONSENSUS BLEND OF ALL MODEL GUIDANCE YIELDS A HIGH TEMP IN THE MID TO UPPER 70S ACROSS THE NRN MTNS AND LAUREL HIGHLANDS...AND MID TO UPPER 80S THROUGHOUT THE VALLEYS OF CENTRAL AND SERN PENN. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... THE SCATTERED SHRA/TSRA LATE THIS AFTERNOON/EVENING ASSOCIATED WITH A WEAK COLD FRONT /AND PRE-FRONTAL TROUGH/ SHOULD DECREASE IN CVRG TONIGHT INTO EARLY WED WITH THE LOSS OF DAYTIME HEATING/INSTABILITY. CONCERNED THAT THE APPROACH OF A STRONG /90 KT/ 300 MB JET AND INCREASING DEEP LAYER UVVEL/STRONG PVA ASSOCIATED WITH THE THERMALLY INDIRECT TRANSVERSE CIRCULATION OF ITS LEFT EXIT REGION WILL SPARK A SEVERAL TO 6-HOUR PERIOD OF MORE NUMEROUS SHOWERS AND TSRA PRECEDING A SECONDARY CFRONT VERY EARLY WED ACROSS THE FAR WEST...AND DURING THE MID MORNING THROUGH MID AFTERNOON HOURS ACROSS THE CENTRAL AND SE ZONES. THE POTENTIAL FEW ROUNDS OF SHOWERS AND TSRA ALONG AND AHEAD OF THIS SECONDARY CFRONT SHOULD BE THE LAST DECENT OPPORTUNITY FOR RAINFALL HERE IN CENTRAL PA FOR AT LEAST 2-3 DAYS. 0-3 KM BULK SHEAR DOES HOWEVER INCREASED TO 25-30 KTS FROM THE WEST TO SOUTHWEST WEDNESDAY...WITH 0-6KM BULK SHEAR OF 40-45 KTS ACROSS NRN PENN IN THE MORNING...AND A RIBBON OF 50-60 KT SHEAR ACRS SOUTHERN PENN LATE WED AFTERNOON. HOWEVER... THE DY2 SPC CONVECTIVE OUTLOOK CONTINUES TO INDICATE ONLY FOR GENERAL THUNDER...WITH THE STG-SVR STORM THREAT LIMITED BY THE APPARENT LACK OF DEEP LYR MSTR/AVG PWS AND CAPE. WOULDN/T BE SURPRISED TO SEE THIS INCREASED TO A SEE TEXT /OR EVEN A COMPACT SLIGHT RISK AREA ACROSS PENN/ WITH LATER UPDATES. STRONG SUBSIDENCE BENEATH THE LEFT ENTRANCE REGION OF THE JET WILL LEAD TO CLEARING AND A RELATIVE MIN OF PRECIP ACROSS THE NRN THIRD TO HALF OF THE STATE AFTER 21Z WED...WHILE ISOLATED TO SCATTERED SHRA/TSRA LINGER ACROSS THE SOUTH. LOW TEMPS TONIGHT UNDER A FAIR AMOUNT OF CLOUD COVER /50-70 PERCENT/ WILL BE IN THE MID 50S TO MID 60S...WITH HIGH TEMPS WEDNESDAY VARYING FROM THE LOWER 70S ACROSS THE NRN MTNS...TO THE LOWER 80S IN THE SE. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... LG SCALE FORCING AND COOLER AIR ALOFT/STEEP MID-LVL LAPSE RATES TIED TO PASSAGE OF UPPER LEVEL TROUGH AXIS MAY PROVIDE ENOUGH LIFT TO GENERATE ISOLD...INSTABILITY TYPE SHOWERS ON THU AFTN. OTHERWISE ANTICIPATE A DRY PERIOD THROUGH THE UPCOMING WEEKEND AND INTO EARLY NEXT WEEK...WITH STRING OF PLEASANT DAYS/COMFORTABLE NIGHTS AS AREA REMAINS UNDER THE INFLUENCE OF SFC HIGH PRES MIGRATING S/SEWD FROM THE UPPER GRT LKS. TEMPS WILL START OUT BELOW AVG BEHIND THE DEPARTING TROUGH AXIS BUT SHOULD MODERATE AS HEIGHTS REBOUND BY 10/11 AUG. && .AVIATION /08Z TUESDAY THROUGH SATURDAY/... SURFACE HIGH PRESSURE WILL KEEP CLEAR SKIES AND VERY LIGHT WINDS ACROSS CENTRAL PA THROUGH THE OVERNIGHT HOURS. THOUGH NOT AS MUCH LOW LEVEL MOISTURE AROUND AS LAST NIGHT SO FOG WILL BE MORE LIMITED. ISOLATED IFR CONDITIONS POSS ACROSS NORTHERN AND CENTRAL MTNS...THOUGH MOST LOCATIONS SHOULD SETTLE INTO MVFR CONDITIONS DURING THE PREDAWN HOURS. CONDITIONS WILL QUICKLY RETURN TO VFR AREAWIDE DURING THE DAY TUESDAY. CLOUDS WILL REMAIN FEW TO SCATTERED IN THE SE HALF OF CWA...BUT A WEAK FRONTAL SYSTEM SLIDING INTO THE NW WILL BRING LOCAL MVFR CONDITIONS IN SCT AFTERNOON SHOWERS/ISO TSTMS. WINDS WILL REMAIN LIGHT. SCT MVFR RESTRICTIONS POSS AGAIN TONIGHT ALONG WITH LINGERING CHANCE FOR SHOWERS /MAINLY NORTHWEST/. SCT SHOWERS/TSTMS RETURN FOR WED. OUTLOOK... TUE...SCATTERED SHRA/TSRA WITH APPROACHING COLD FRONT...MAINLY NW. WED...SCATTERED SHRA/TSRA. THU-SAT...MAINLY VFR. PATCHY FOG POSSIBLE EARLY. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...LAMBERT LONG TERM...LAMBERT/STEINBUGL AVIATION...RXR
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1143 PM CDT MON AUG 4 2014 .DISCUSSION... SEE 06Z AVIATION DISCUSSION. && .AVIATION... ISOLATED SHRA CONTINUE NEAR THE COAST AND HAVE ADDED A VCSH FOR KLBX THROUGH 09Z. PATCHY FOG HAS ALSO BEGUN TO DEVELOP AND THINK THE BEST POTENTIAL FOR FOG WILL BE AT KLBX...KIAH AND KCXO. MODELS HAVE HAD SOME DIFFICULTY THE LAST COUPLE OF NIGHT WITH CIGS SO NOT TERRIBLY CONFIDENT WITH VFR CIGS ALL NIGHT. THE LATEST RAP AND 4 KM WRF FOCUS SOME AFTN SHRA OVER MAINLY THE NE HALF OF SE TX. FCST SOUNDINGS ALSO SHOW PW VALUES INCREASING TO AROUND 1.8-1.9 INCHES AROUND 21Z SO ADDED VCSH FOR KUTS AND KCXO FOR TUES AFTN. 43 && .PREV DISCUSSION... /ISSUED 904 PM CDT MON AUG 4 2014/ UPDATE... SEE DISCUSSION FOR EVENING UPDATE. DISCUSSION... NOT MANY CHANGES TO FORECAST PACKAGE THIS EVENING. PERSISTENT LOW PRESSURE OFF THE COAST OF LOUISIANA HAS FINALLY STARTED TO WASH OUT THIS EVENING. STILL GETTING SOME SHOWERS AND THUNDERSTORMS ACROSS OUR FAR NORTHERN ZONES AT THIS TIME BUT COVERAGE SHOULD CONTINUE TO QUICKLY DECREASE THANKS TO THE LOSS OF DAY TIME HEATING. TOMORROW AFTERNOON EXPECT SLIGHTLY WARMER HIGH TEMPERATURES AGAIN AS 850 TEMPERATURES CONTINUE THEIR SLOW CLIMB. MADE MINOR TWEAKS TO HIGH TEMPERATURE AND POP GRIDS BASED ON CURRENT TRENDS. NO OTHER CHANGES REQUIRED AT THIS TIME. 23 PREV DISCUSSION... /ISSUED 308 PM CDT MON AUG 4 2014/ DISCUSSION... FINALLY GETTING THE SCT PCPN THAT HAS BEEN ADVERTISED THESE LAST FEW DAYS (VIA THE PESKY LOW THAT MOVED IN FROM THE E YESTERDAY). PER SATELLITE/SFC ANALYSES THIS SYSTEM HAS WEAKENED CONSIDERABLY TODAY AND THIS TREND WILL LIKELY CONTINUE TONIGHT. OVERALL NOT A LOT OF CHANGE WITH THE FCST THE REST OF THE WEEK AS WE SETTLE IN- TO A MORE TYPICAL SUMMERTIME PATTERN OF WEAK UPPER LEVEL RIDGING (AS THE TROF MOVES OFF TO THE EAST). MOST NOTABLE CHANGES IN THE FCST APPEARS TO BE IN THE EXTENDED WHERE ECMWF HAS A MUCH STRONG- ER UPPER RIDGE SETTLING OVER THE STATE AT THE END OF THE WEEK AS OPPOSED TO THE GFS...WHICH IS NOW GOING WITH THE SHEAR AXIS/WEAK TROFFING SCENARIO. AS SUCH...WILL BE KEEPING WITH THE GOING FCST OF MAINLY DAYTIME SEABREEZE DRIVEN PCPN IN THE MID/EXTENDED PART OF THE FCST. ALSO NOT REALLY SOLD ON THE MOS GUIDANCE HIGH TEMPS FOR THE LATTER PART OF THE WEEK (GIVEN THE UNCERTAINTY REGARDING UPPER RIDGE STRENGTH) SO WILL KEEP THESE NUMBERS CLOSE TO NORMAL. 41 MARINE... EASTERLY WINDS ACROSS THE COASTAL WATERS THIS AFTERNOON WILL BECOME ONSHORE OVER THE NEXT 24 HOURS. THIS ONSHORE FLOW WILL PERSIST THROUGH THE END OF THE WEEK WITH WIND SPEEDS INCREASING LATE WEEK AS A SURFACE LOW BEGINS TO DEVELOP ACROSS THE SOUTHERN PLAINS. 38 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 74 94 75 95 75 / 30 20 20 20 10 HOUSTON (IAH) 75 93 76 95 76 / 30 20 20 20 10 GALVESTON (GLS) 79 91 81 91 81 / 30 20 20 20 20 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...23 AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
312 AM CDT TUE AUG 5 2014 .SHORT TERM... TODAY AND TONIGHT...FORECAST CONFIDENCE IS HIGH. THE MID/UPPER LEVEL TROUGH WILL EXIT THE LAKE MICHIGAN AREA AROUND SUNRISE THIS MORNING. THE 250 MB JET MAX BEHIND THE TROUGH INCREASES TO 100 KNOTS THIS AFTERNOON OVER WISCONSIN BEFORE MOVING INTO LOWER MICHIGAN EARLY WEDNESDAY MORNING. THIS PUTS SOUTHWEST WISCONSIN IN THE LEFT EXIT REGION OF THE JET. AS A RESULT UPPER DIVERGENCE INCREASES OVER MUCH OF SOUTH CENTRAL AND FAR SOUTHEAST WISCONSIN. THE MODERATE 700 MB UPWARD MOTION IS FARTHER SOUTH ACROSS IOWA AND NORTHWEST ILLINOIS LATE TONIGHT. AS A RESULT MOST MODELS KEEP THE PRECIPITATION JUST SOUTHWEST AND SOUTH OF THE FORECAST AREA. HOWEVER THE NAM DOES BRING SOME PRECIPITATION TO AREAS MAINLY SOUTHWEST OF MADISON. WILL INCLUDE A CHANCE OF SHOWERS LATE TONIGHT TO ACCOUNT FOR THIS POSSIBILITY. 850 MB MOISTURE REMAINS TODAY BEFORE DRYING FROM THE NORTHEAST TONIGHT EXCEPT FOR THE FAR SOUTHWEST. ZERO TO 1 KM MIXED LAYER CAPE REACHES 1000 JOULES/KG ALONG THE ILLINOIS BORDER WITH LESS THAN 200 JOULES/KG NEAR SHEBOYGAN. THEREFORE ISOLATED SHOWERS ARE NOT OUT OF THE QUESTION. HOWEVER THE HRRR IS DRY THROUGH 19Z WITH ONLY A FEW SHOWERS POSSIBLE ALONG THE LAKE BREEZE FRONT. THE 00Z HIGH RES WRF/ARW DOES BRING A FEW ISOLATED LIGHT SHOWERS. OTHERWISE THE MAIN PROBLEM IS FOG...WITH A FEW AREAS DENSE...DURING THE EARLY MORNING TODAY. THE FOG/STRATUS WILL DISSIPATE IN THE MID/LATE MORNING HOURS. TUESDAY NIGHT THROUGH FRIDAY...FORECAST CONFIDENCE HIGH. A LARGE UPPER LOW WILL SIT OVER JAMES BAY THROUGH SATURDAY. THE TROUGH WILL EXTEND ALL THE WAY DOWN ACROSS THE SOUTHEAST STATES. NORTHWEST FLOW WILL PREVAIL ACROSS SOUTHERN WI. WEAK SHORTWAVES ROTATING AROUND THE UPPER LOW AND STEEP LOW LEVEL LAPSE RATES WILL LEAD TO SCATTERED DIURNAL SHOWERS WITH A FEW RUMBLES OF THUNDER EACH DAY FROM LATE MORNING THROUGH EARLY EVENING. AFTERNOON CAPE VALUES WILL BE ON THE LOWER SIDE...AROUND 100 TO 300 J/KG... ON WEDNESDAY...THUS LOWER CHANCES FOR THUNDER. HIGHER VALUES OF 700-900 J/KG CAPE ARE EXPECTED FOR THU AND FRIDAY AFTERNOONS. THE MORE DISTINCT AND AGREED UPON BETWEEN MODELS SHORTWAVE TROUGH SHOULD SWING THROUGH SOUTHERN WI FRIDAY AFTERNOON/EVENING...THUS THE BEST DAY FOR MORE WIDESPREAD AND HEAVIER SHOWERS AND THUNDERSTORMS. 850MB TEMPS WILL BE AROUND 10C TO 12C AND 925MB TEMPS AROUND 19C THROUGHOUT THE WEEK. THIS TRANSLATES TO HIGHS IN THE UPPER 70S TO AROUND 80 AND LOWS IN THE 50S. .LONG TERM... SATURDAY THROUGH MONDAY...FORECAST CONFIDENCE MEDIUM. THE UPPER TROUGH WILL BEGIN TO SHIFT EAST LATER SATURDAY THROUGH SUNDAY. SHOWERS ARE POSSIBLE ONCE AGAIN SATURDAY AFTERNOON...BUT LESS LIKELY ON SUNDAY AS DRY HIGH PRESSURE SLIDES ACROSS THE WESTERN GREAT LAKES. A SURFACE AND UPPER LOW PRESSURE TROUGH WILL LIKELY LINGER OVER NORTHERN WI SUNDAY NIGHT. MEANWHILE...SOUTHERLY FLOW ON THE BACK SIDE OF THE HIGH WILL ALLOW 850MB TEMPS TO INCREASE TO 14C AND 925MB TEMPS TO AROUND 22C BY MONDAY MORNING. EVENTUALLY...THAT SURFACE TROUGH WILL SLIDE DOWN THROUGH SOUTHERN WI TO BRING THE NEXT CHANCE FOR SHOWERS AND THUNDERSTORMS MONDAY AFTERNOON AND NIGHT. DRY AND COOL HIGH PRESSURE IS EXPECTED TO SET UP ONCE AGAIN EARLY NEXT WEEK. && .AVIATION/12Z TAFS/... SATURATED LOW LEVELS WILL BRING AREAS OF IFR/LIFR FOG/STRATUS. A FEW SPOTS WILL BE AROUND 1/4 MILE. THE FOG AND STRATUS WILL LIFT/DISSIPATE DURING THE MID/LATE MORNING. THEN MVFR CIGS BECOMING MAINLY VFR LATER THIS AFTERNOON. ISOLATED SHOWERS [POSSIBLE MAINLY THIS AFTERNOON. HIGH PRESSURE WILL BUILD OVER THE GREAT LAKES TONIGHT. SHOWERS POSSIBLE LATE TONIGHT SOUTHWEST OF MADISON ASSOCIATED WITH AN UPPER JET MAX. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ TODAY/TONIGHT AND AVIATION/MARINE...HENTZ WEDNESDAY THROUGH MONDAY...MRC
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1127 PM MDT MON AUG 4 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY EVENING) ISSUED AT 230 PM MDT MON AUG 4 2014 CURRENTLY...WATER VAPOR IMAGERY SHOWING MONSOONAL MOISTURE MOVING INTO OUR WESTERN ZONES THIS AFTERNOON AS THE UPPER LOW THAT WAS OVER SOUTHERN CALIFORNIA YESTERDAY MOVES INTO CENTRAL UTAH. 12Z PWATS ON THE GJT SOUNDING OVER 1.2 INCHES. THIS MOISTURE IS HEADED OUR WAY. MOSAIC RADAR SHOWING FAIRLY WIDESPREAD LIGHT RAIN OVER CARBON COUNTY. A FEW THUNDERSTORMS DEVELOPING NEAR ARLINGTON AND CENTENNIAL WITH A FEW LIGHTNING STRIKES OBSERVED. BEGINNING TO SEE SOME CELLS DEVELOPING ON THE RADAR UP BY VEDAUWOO...SO SHOWERS HERE AT CHEYENNE ARE NOT THAT FAR OFF. FOR THIS AFTERNOON...LATEST HRRR FORECAST SHOWING CELLS DEVELOPING OVER THE LARAMIE RANGE AND DRIFTING EAST. ITS SHOWING A FAIRLY WIDESPREAD BAND OF SHOWERS AND THUNDERSTORMS MOVING SLOWLY EAST INTO THE PANHANDLE AROUND THE 23Z TIME FRAME. STORMS ARE GOING TO BE VERY SLOW MOVING...FROM THE SOUTHWEST AT UNDER 5KTS. THOSE AREAS THAT DO EXPERIENCE THUNDERSTORMS THIS AFTERNOON AND THIS EVENING COULD SEE CONSIDERABLE RAINFALL WITH THESE SLOW MOVING STORMS. UPPER SHORTWAVE MOVES BEST LIFT NORTH THIS EVENING...SO WE SHOULD SEE A LULL IN CONVECTION AFTER 03Z OR SO UNTIL TUESDAY. DRIED OUT THE SOUTHERN PANHANDLE AND SOUTHEAST WYOMING FROM LARAMIE TO WHEATLAND TO TORRINGTON THIS EVENING. NEXT PIECE OF ENERGY TO MOVE THROUGH THE AREA TUESDAY AFTERNOON AND EVENING AS THE UPPER LOW OPENS UP AND TRACKS INTO WESTERN WYOMING. NAM AND ECMWF SHOW GOOD QPF ACROSS MOST OF THE CWFA...CONCENTRATED ACROSS THE SOUTHERN PANHANDLE AND LARAMIE COUNTY TUESDAY AFTERNOON. STILL NOT MUCH IN THE STEERING FLOW...SO STORMS WILL ONCE AGAIN BE SLOW MOVING AND PRODUCING MODERATE TO HEAVY RAINFALL INTO TUESDAY EVENING. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 1222 PM MDT MON AUG 4 2014 WEDNESDAY...DESPITE A SHORTWAVE RIDGE ALOFT OVER OUR COUNTIES...WITH A LOW LEVEL CONVERGENCE BOUNDARY INDICATED FROM DOUGLAS TO CHEYENNE...ALONG WITH ADEQUATE LOW AND MID LEVEL MOISTURE AND DECENT UPWARD VERTICAL MOTION FROM DOUGLAS TO CHEYENNE...HAVE BOOSTED AFTERNOON AND EVENING POPS INTO THE 45 TO 70 PERCENT RANGE...WITH LESSER POPS ELSEWHERE. WITH WEAK STEERING WINDS...WILL LIKELY SEE A FEW HEAVY RAINERS AS WELL. THURSDAY...NEXT SHORTWAVE TROUGH ALOFT MOVES INTO WESTERN WYOMING AND UTAH...WHILE A LOW LEVEL CONVERGENCE AXIS SETS UP FROM NORTH CENTRAL COLORADO NORTHWARD TO NEAR TORRINGTON TO NEAR CHADRON. 850/700 MB THETA-E RIDGE AXIS...WELL PRONOUNCED...WILL EXTEND NORTH TO SOUTH IN THE AFTERNOON ACROSS FAR EASTERN WYOMING AND WESTERN NEBRASKA...AND WITH PROGGED INSTABILITIES...CAPE AND DECENT DIRECTIONAL SHEAR...EXPECT A FEW STRONG TO SEVERE THUNDERSTORMS EAST OF A LUSK TO CHEYENNE LINE...AND HAVE ALSO BOOSTED POPS EAST OF THIS LINE TO THE 50 TO 60 PERCENT RANGE WITH ALL CONVECTIVE AND MESOSCALE PARAMETERS COMING TOGETHER. FRIDAY...LESS LATE DAY COVERAGE OF SHOWERS AND THUNDERSTORMS EXPECTED WITH DECREASE IN LOW AND MID LEVEL MOISTURE...THOUGH WILL STILL SEE ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS IN THE AFTERNOON AND EVENING WITH MOIST UPSLOPE MECHANICAL LIFT. SATURDAY...SIMILAR SCENARIO TO FRIDAY...ALBEIT WITH SLIGHTLY LESS COVERAGE OF SHOWERS AND THUNDERSTORMS DUE TO LESS LOW AND MID LEVEL MOISTURE AVAILABILITY. SUNDAY...RIDGING ALOFT STRENGTHENS OVER OUR COUNTIES...THUS EXPECT SLIGHTLY LESS COVERAGE OF LATE DAY SHOWERS AND THUNDERSTORMS...FOCUSED ALMOST EXCLUSIVELY OVER THE MOUNTAINS AND HIGHER TERRAIN SUCH AS THE PINE RIDGE FROM NEAR LUSK TO NEAR CHADRON. MONDAY...EVEN MORE PRONOUNCED RIDGING ALOFT...AND WITH THE BULK OF THE MONSOONAL MOISTURE RESIDING OVER COLORADO...WILL ONLY FORECAST ISOLATED LATE DAY THUNDERSTORMS OVER AND NEAR THE SNOWY...SIERRA MADRE AND SOUTHERN LARAMIE RANGES...THOUGH WE WILL NEED TO WATCH FOR POSSIBLE GREATER INTRUSION OF MID LEVEL MONSOONAL MOISTURE AS IS TYPICAL FOR LATE JULY AND EARLY AUGUST. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY EVENING) ISSUED AT 1122 PM MDT MON AUG 4 2014 SHOWERS WILL CONTINUE TO DECREASE IN COVERAGE THROUGH THE LATE EVENING HOURS. MVFR TO IFR CIGS AND VSBYS ARE EXPECTED TO DEVELOP OVER THE NORTHERN NE PANHANDLE AFTER 09Z TUE...MAINLY FOR KAIA AND KCDR. CONDITIONS WILL BE SLOW TO IMPROVE ACROSS THOSE AREAS ON TUE WITH AT LEAST MVFR CONDITIONS EXPECTED TO PERSIST THROUGH AT LEAST EARLY AFTN. VFR CONDITIONS EXPECTED ELSEWHERE...WITH MORE SHOWERS AND STORMS EXPECTED AFTER 17-18Z AND POTENTIAL FOR BRIEF MVFR VSBYS AND GUSTY WINDS/SMALL HAIL. && .FIRE WEATHER... ISSUED AT 230 PM MDT MON AUG 4 2014 MONSOONAL MOISTURE WILL STAY WITH US THROUGH MOST OF THE WEEK GIVING MOST AREAS CHANCES FOR WETTING RAINS AND THUNDERSTORMS ON A DAILY BASIS. WINDS TO REMAIN WEAK AND AFTERNOON HUMIDITIES FAIRLY HIGH...MITIGATING ANY FIRE WEATHER CONCERNS. MIN HUMIDITIES EXPECTED TO STAY IN THE MID 20 PERCENT RANGE THROUGH THE WEEK WITH EXCELLENT OVERNIGHT RECOVERIES. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ SHORT TERM...CLAYCOMB LONG TERM...RUBIN AVIATION...HAMMER FIRE WEATHER...CLAYCOMB
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1112 AM EDT TUE AUG 5 2014 .SYNOPSIS... SCATTERED SHOWERS AND THUNDERSTORMS ARE ANTICIPATED LATE TODAY AND AGAIN ON WEDNESDAY AS HURRICANE BERTHA PASSES WELL OFFSHORE OF NEW ENGLAND WITH LITTLE IMPACT OTHER THAN HIGH SURF AND DANGEROUS RIP CURRENTS. A COLD FRONT WILL MOVE OFFSHORE WEDNESDAY NIGHT. ASIDE FROM A FEW SHOWERS THURSDAY AND FRIDAY AFTERNOON...HIGH PRESSURE BRINGS DRY WEATHER INTO THE WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 1050 AM UPDATE... MONITORING BOTH KENX AND KOKX RADARS...SAW A LONELY SHOWER MOVE ACROSS CENTRAL VT INTO CENTRAL NH BEFORE DISSIPATING AROUND 14Z. ALSO SEE A BAND OF CUMULUS CLOUDS FORMING ALONG DEVELOPING SEA BREEZE FRONT ACROSS S CT ON LATEST VISIBLE SATELLITE LOOP. WILL CONTINUE TO MONITOR RADAR FOR SHOWER DEVELOPMENT...IF IT OCCURS DURING THE EARLY AFTERNOON. NOTING LATEST HRRR FORECAST RADAR TRENDS INDICATING ISOLD SHOWERS ACROSS S NH/N MA AND POSSIBLY ALONG SEA BREEZE FRONT ACROSS S CT...BUT AGAIN WILL MONITOR. TEMPS HAVE RISEN STEADILY SINCE SUNRISE...WITH READINGS IN THE 70S TO LOWER 80S AT 15Z...UP TO 84 AT KFIT. TEMPS/DEWPTS WERE CLOSE TO FORECASTED TRENDS. HAVE UPDATED GRIDS TO BRING CONDITIONS CURRENT. PREVIOUS DISCUSSION... BERTHA TO THE SE WHILE A BROAD-TROUGH SWEEPS ACROSS THE GREAT LAKES. PREVAILING SUBSIDENCE/DRY AIR /H85-H3/ BETWEEN THE TWO COLLOCATED WITH THE LEFT-ENTRANCE REGION OF THE H3 JET SHOULD RESULT IN QUIET WEATHER ACROSS S NEW ENGLAND INTO AFTERNOON. BUT WITH THE WESTERN APPROACH OF A COLD FRONT ASSOCIATED WITH THE BROAD H5 TROUGH...EXPECT THE INCREASE OF CYCLONIC FLOW AND ENHANCED ASCENT ALLOWING THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS OVER W MA / CT AND SW NH. COULD ALSO SEE ACTIVITY ASSOCIATED WITH LOCALIZED CONVERGENCE ALONG SEA-BREEZE BOUNDARIES. CONSIDERING INSTABILITY OF AROUND 1000 J/KG ALONG WITH 30 KTS OF BULK SHEAR...ORDINARY TO MULTI-CELLULAR CONVECTION IS ANTICIPATED. NOTING FORECAST SOUNDINGS WITH FREEZING LEVELS AROUND 10 KFT ALONG WITH A COMBINATION OF THIN-CAPE AND POTENTIAL INVERTED-V PROFILES... FEEL THERE IS AN ISOLATED THREAT OF HEAVY RAIN...STRONG TO DAMAGING WINDS...AND SMALL HAIL /IN PRIORITY OF CONCERN/. WARM AND HUMID CONDITIONS CONTINUING AS TEMPERATURES WARM TO AROUND THE MID-80S WITH DEWPOINTS RANGING AROUND THE MID-60S. COOLER ALONG THE SHORELINES WITH ANTICIPATED SEA-BREEZES. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... TONIGHT... COLD FRONTAL BOUNDARY CONTINUES TO SWEEP INTO S NEW ENGLAND. EXPECT SCATTERED SHOWER / THUNDERSTORM ACTIVITY...STRONGEST OF WHICH WILL CONTINUE TO BE ACROSS N/W INTERIOR...WEAKENING OVER TIME WITH THE LACK OF DAY-TIME HEATING AND INSTABILITY. FALLING HEIGHTS / CYCLONIC FLOW MAY PROLONG SHOWER ACTIVITY TILL AFTER MIDNIGHT AND TOWARDS THE COASTLINES. OTHERWISE...SOUPY AIR WITH DEWPOINTS AROUND THE MID-60S MAINTAINED BY SW FLOW WILL LIKELY RESULT IN ANOTHER NIGHT OF LOW-CLOUDS AND DENSE FOG FOR PORTIONS OF S/SE NEW ENGLAND ESPECIALLY ALONG THE SHORELINES. DRIER AIR BUILDING IN BEHIND THE FRONT SHOULD KEEP AREAS OF THE N/W INTERIOR FOG-FREE. LOWS NW-SE RANGING FROM THE LOW-60S TO UPPER-60S. WEDNESDAY... SYNOPTICALLY...IGNORE THE PRESSURE PATTERN. BELIEVE THE OVERNIGHT COLD FRONT BECOMES DIFFUSE AS A BROAD AREA OF LOW PRESSURE SITUATED MAINLY ACROSS SE NEW ENGLAND. AS THE MAIN CRUX OF ENERGY SWEEPS THROUGH THE PREVAILING MID-LEVEL BROAD TROUGH...FALLING HEIGHTS ARE INVOKED THROUGHOUT THE ATMOSPHERIC COLUMN. THE COMBINATION OF THE LEFT-FRONT-QUADRANT ASSOCIATED WITH THE H3 CYCLONIC JET...MID- LEVEL ENHANCED ASCENT...AND LOCALIZED CONVERGENCE OF A SOUPY UNSTABLE AIRMASS ALONG SEA-BREEZE BOUNDARIES...DEEP-LAYER ASCENT PREVAILS. ANTICIPATE SCATTERED SHOWER AND THUNDERSTORM ACTIVITY MAINLY ACROSS S/E INTERIOR NEW ENGLAND INCORPORATING E MA AND RI. ASSUMING INSTABILITY VALUES AROUND 1000 J/KG WILL BE MET IN AN ENVIRONMENT OF AVERAGE 30 KT W-E UNI-DIRECTIONAL SHEAR SHOULD YIELD ORDINARY TO MULTI-CELLULAR CONVECTION ALONG THE SEA-BREEZE BOUNDARIES. PWATS RANGE 1.0 - 1.5 INCHES. ONCE AGAIN...NOTING FORECAST SOUNDINGS WITH FREEZING LEVELS AROUND 10 KFT ALONG WITH A COMBINATION OF THIN-CAPE AND POTENTIAL INVERTED-V PROFILES...FEEL THERE IS AN ISOLATED THREAT OF HEAVY RAIN...STRONG TO DAMAGING WINDS...AND SMALL HAIL /IN PRIORITY OF CONCERN/. A GREATER THREAT OF URBAN FLOODING IS CERTAINLY PLAUSIBLE SHOULD STORMS PERPETUATE ALONG THE SEA-BREEZE. WARM AND MUGGY CONDITIONS EXPECTED MORE S/E WITH HIGHS AROUND THE UPPER-70S. COOLER AND DRIER N/W THOUGH LOW-80S POSSIBLE OVER THE LOWER CT-VALLEY. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... OVERVIEW AND MODEL PREFERENCES... 05.00Z MODEL GUIDANCE ACTUALLY HAS FAIRLY GOOD AGREEMENT THROUGH MUCH OF THE LONG TERM IN SPITE OF THE FACT CONDITIONS FAVOR A FAIRLY AMPLIFIED FLOW PATTERN INTO THE WEEKEND. BASE OF A LONGWAVE TROF WITH HEIGHTS NEARLY 3 STD DEVIATIONS BELOW NORMAL WILL BE MOVING ACROSS NEW ENGLAND THU. THANKFULLY THE ORIENTATION AND MOVEMENT WILL BE ENOUGH TO FORCE BOTH THE REMNANTS OF BERTHA AND ITS MOISTURE WELL E OF NEW ENGLAND...ALLOWING THE DRIER AIR FROM RIDGING ACROSS THE GREAT LAKES INTO NEW ENGLAND INSTEAD. FOLLOWING THIS TROF...THE MID LVL RIDGE WILL THEN HOLD FAST ACROSS MUCH OF THE N CONUS AS DEEPENING TROF DEVELOPS ACROSS THE CANADIAN PRAIRIE INTO THE LATE WEEKEND AND EARLY NEXT WEEK. WITH THIS REASONABLY GOOD AGREEMENT...A BLEND OF LONG RANGE GUIDANCE WILL BE USED AS A BASELINE FOR THIS UPDATE. DETAILS... THU INTO FRI... ALTHOUGH SFC COLD FRONT WILL CONTINUE TO MOVE OFFSHORE DURING THE DAY THU...ACUTE VORT MAX WILL PIVOT ACROSS THE REGION DURING THE DAYLIGHT HOURS...AND LINGERING INTO FRI. THIS IS ASSOCIATED WITH VERY LOW H5 HEIGHTS AND TEMPS APPROACHING -18C. THEREFORE...WITH A FOCUS FOR LIFT AND SOME MID LVL DESTABILIZATION /MU CAPE VALUES MAY REACH AROUND 500J/KG IN SPOTS ON THU...SLIGHTLY LOWER ON FRI/ MAY SEE DIURNALLY DRIVEN SHOWERS AND POSSIBLY EVEN AN ISOLATED RUMBLE OF THUNDER. AT THE VERY LEAST LIKELY TO SEE A DECK OF SCT-BKN CU FOR EACH AFTERNOON AND EARLY EVENING. WITH SOME DRIER AIR THROUGH THE COLUMN STABILIZING THE AIRMASS FRI...WILL FEATURE HIGHER CHANCE POPS ON THU THAN FRI. GIVEN THE COOL TEMPS ALOFT AND FAIR AMOUNT OF DIURNAL CLOUD COVER...EXPECT TEMPS TO BE MAINLY BELOW NORMAL. HIGHS IN THE MID 70S...LOWS DIPPING INTO THE 50S IN SPOTS...LOW 60S IN NORMAL URBAN HEAT ISLANDS. THIS COMING WEEKEND... MID LVL RIDGE WILL BE SLOWLY MOVING IN FROM THE GREAT LAKES REGION. ATTENDANT HIGH PRES WILL MOVE ACROSS MUCH OF NEW ENGLAND THROUGH THE WEEKEND. +12C H85 TEMPS ON SAT FOLLOWED BY +14C ON SUN SUGGESTS TEMPS NEAR NORMAL ON SAT /HIGHS AROUND 80-LOW 80S/ AND SOMEWHAT ABOVE NORMAL SUN /HIGHS IN THE MID 80S/. MON INTO TUE... SOME DISAGREEMENT BEGINS TO SHOW HERE...MAINLY WITH THE TIMING AND DEPTH OF A LONGWAVE TROF MOVING E FROM THE CANADIAN PRAIRIE. AT THIS POINT IT LOOKS LIKE THE MID LVL RIDGE HAS HIGH ENOUGH HEIGHTS THAT IT SHOULD HOLD AS THE TROF DEEPENS TO KEEP AN PRECIP FROM A SLOWLY LIFTING WARM FRONT WELL TO THE S. WILL MAINTAIN A MOSTLY DRY FORECAST...BUT GIVEN THERE IS A PATTERN SHIFT AFOOT...WILL HAVE TO MONITOR THE TRENDS AS WEE GO THROUGH WEEK. THE E SHIFT IN THE SFC HIGH PRES SUGGESTS RETURN FLOW WITH INCREASING TEMPS AND HUMIDITY EACH DAY. && .AVIATION /15Z TUESDAY THROUGH SATURDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM...THROUGH WEDNESDAY... THIS AFTERNOON...MODERATE CONFIDENCE. EXPECT MAINLY VFR ACROSS MOST AREAS...BUT LOCAL MVFR-IFR MAY LINGER ACROSS KACK THROUGH 18Z OR SO. SOME ISOLD -SHRA/TSRA POSSIBLE...ESPECIALLY INTERIOR TERMINALS. WINDS MAINLY W-SW. SEA BREEZES FOR COASTAL TERMINALS. TONIGHT...MODERATE CONFIDENCE. SHRA/TSRA DISSIPATING AROUND 3Z ACROSS INTERIOR S NEW ENGLAND. WILL SEE THE RETURN OF MVFR-VLIFR CIGS/VSBYS...MAINLY FOR S/E NEW ENGLAND COASTLINES. WEDNESDAY... MVFR-VLIFR CIGS/VSBYS DISSIPATE. SEA-BREEZES AROUND 15Z BECOME THE FOCUS FOR SHRA/TSRA ACROSS INTERIOR E/SE MA AND ALL OF RI. ACTIVITY FURTHER W POSSIBLE. KBOS TERMINAL...MODERATE CONFIDENCE. LIGHT SEA BREEZE THROUGH 22Z-23Z. KBDL TERMINAL...HIGH CONFIDENCE. OUTLOOK...WED NIGHT THROUGH SATURDAY... WED NIGHT...MODERATE CONFIDENCE. SOME MIXED MVFR CONDITIONS IN FOG AND SHOWERS DURING THE EVENING GIVES WAY TO SOME IMPROVEMENT EARLY THU MORNING. THU INTO SAT...HIGH CONFIDENCE. MAINLY VFR...BUT THU AND FRI A BRIEF MVFR PERIOD IS POSSIBLE IN AFTERNOON SHOWERS OR AN ISOLATED THUNDERSTORMS. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM...THIS AFTERNOON THROUGH WEDNESDAY... SWELLS WILL INCREASE AS BERTHA MAKES ITS CLOSEST APPROACH LATE TONIGHT. THIS WILL LEND TO INCREASING WAVE HEIGHTS ACROSS THE S/SE WATERS. SMALL CRAFT ADVISORIES FOR HAZARDOUS SEAS ISSUED ACCORDINGLY WITH WAVE HEIGHTS UP TO 7 FEET POSSIBLE. THE DELAY IN SWELL AND LIGHT WINDS FOR TODAY WILL LIMIT THE RIP CURRENT RISK...BUT WILL NEED TO WATCH FOR POTENTIAL HAZARDS TONIGHT INTO WEDNESDAY. LOW CLOUDS AND FOG WILL RETURN LATE TONIGHT INTO WEDNESDAY MORNING...WITH VSBYS AGAIN BELOW 1SM IN SOME AREAS MAINLY S COAST...CAPE COD AND THE ISLANDS. OUTLOOK...WED NIGHT THROUGH SATURDAY... WED NIGHT INTO THU...HIGH CONFIDENCE. ANY SHOWERS ASSOCIATED WITH A COLD FRONT WILL MOVE FURTHER OFFSHORE OVERNIGHT WED NIGHT. OTHERWISE...LINGERING 5-6 FT SWELL FROM BERTHA WILL BE GRADUALLY DIMINISHING INTO THE DAY ON THU. THEREFORE...SMALL CRAFT ADVISORIES ARE LIKELY TO LINGER INTO THU AS THE SWELL SUBSIDES. FRI AND SAT...HIGH CONFIDENCE. A PERIOD OF MAINLY QUIET BOATING WEATHER IS EXPECTED AS HIGH PRES MOVES OVER THE WATERS. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM MIDNIGHT TONIGHT TO 6 PM EDT WEDNESDAY FOR ANZ235-237-254>256. && $$ SYNOPSIS...DOODY/SIPPRELL NEAR TERM...DOODY/SIPPRELL/EVT SHORT TERM...SIPPRELL LONG TERM...DOODY AVIATION...DOODY/SIPPRELL/EVT MARINE...DOODY/SIPPRELL/EVT
AREA FORECAST DISCUSSION
NWS ALBANY NY
1047 AM EDT TUE AUG 5 2014 .SYNOPSIS... PARTLY SUNNY AND WARM WEATHER IS EXPECTED TODAY. A SLOW MOVING COLD FRONT APPROACHING FROM SOUTHERN CANADA WILL BRING A CHANCE FOR THUNDERSTORMS ACROSS MUCH OF THE AREA LATER TODAY AND WEDNESDAY BEFORE CLEARING THE REGION. COOL AND BREEZY WEATHER...WITH A CONTINUED THREAT OF AFTERNOON SHOWERS...IS FORECAST FOR THURSDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 1045 AM EDT...CURRENT FORECAST LOOKS ON TRACK WITH ONLY MINOR TWEAKS TO THE FORECAST TO ACCOUNT FOR SKY COVER AND TEMPS AS ANOTHER MUGGY AND WARM DAY IS IN STORE FOR THE REGION. WITH THE DISSIPATION OF THE EARLY MORNING FOG...MUCH OF THE FORECAST AREA REMAINS MOSTLY SUNNY THIS MORNING WITH CU NOW BEGINNING TO DEVELOP ACROSS THE HIGHER TERRAIN. WITH STRONG DAYTIME HEATING EXPECTED...TEMPS SHOULD REACH INTO THE MID AND UPPER 80S ACROSS MUCH OF THE REGION EXCEPT FOR UPPER 70S TO LOW 80S ACROSS THE SOUTHERN ADIRONDACKS. COMBINED WITH DEWPOINTS IN THE LOW TO MID 60S AND MARGINAL MIDLEVEL LAPSE RATES AROUND 6.0 C/KM...AROUND 500-1500 J/KG OF SBCAPE IS EXPECTED BY MID AFTERNOON. THERE WILL BE LITTLE IN THE WAY OF DYNAMIC FORCING ACROSS THE REGION...AS A COLD FRONT REMAINS FAR ENOUGH NORTH AND WEST TO ALLOW FOR LOCAL TOPOGRAPHIC/DIFFERENTIAL HEATING BOUNDARIES TO BE THE PRIMARY FOCUS FOR CONVECTION. THE HRRR DEPICTS WIDELY SCATTERED TO SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING BETWEEN 12PM-2PM...AND PERSISTING THROUGH MUCH OF THE AFTERNOON BEFORE A DECAYING CLUSTER OF STORMS CURRENTLY ACROSS THE LOWER GREAT LAKES REACHES THE REGION BY THE LATE EVENING HOURS. ALTHOUGH THERE WILL BE MODEST INSTABILITY IN PLACE...MEAGER DYNAMIC FORCING WILL RESULT IN MAINLY GENERIC THUNDERSTORM ACTIVITY WITH THE STRONGEST STORMS CAPABLE OF BRIEF HEAVY DOWNPOURS THAT MAY PRODUCE LOCALIZED PONDING OF WATER ON ROADWAYS AS WELL AS IN LOW LYING AND URBAN AREAS. HAVE ONLY GONE WITH SLIGHT CHANCE AND CHANCE POPS AS COVERAGE WILL BE SCATTERED AT BEST. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/... ANY LINGERING SHOWERS OR THUNDERSTORMS SHOULD DISSIPATE THROUGH THE EVENING...WITH INTERVALS OF CLOUDS THE REST OF THE NIGHT. THE BETTER UPPER DYNAMICS ASSOCIATED WITH THE UPPER SYSTEM...AND THE BETTER LOW LEVEL FORCING ALONG A TIGHTENING AND ADVANCING BOUNDARY LAYER THERMAL GRADIENT SHOULD SUPPORT SCATTERED SHOWERS AND THUNDERSTORMS WEDNESDAY...MAINLY AFTERNOON AND EVENING. HIGHS WEDNESDAY IN THE MID 70S TO LOWER 80S. ONE LAST LINGERING PIECE OF UPPER ENERGY AND THE UPPER COLD POOL BRUSH JUST NORTH AND NORTHEAST OF OUR REGION THURSDAY SUPPORTING ONE LAST ROUND OF ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS...MAINLY IN NORTHERN AND EASTERN AREAS. COOLING CONTINUES TO TAKE PLACE ACROSS THE REGION...AND HIGHS SHOULD BE IN THE 70S TO NEAR 80. NIGHTTIME LOWS TONIGHT SHOULD BE IN THE UPPER 50S TO LOWER 60S...COOLER IN HIGHER TERRAIN. FOR WEDNESDAY NIGHT AND THURSDAY NIGHT LOWS IN THE 50S WITH AROUND 50 HIGHER TERRAIN. && .LONG TERM /FRIDAY THROUGH MONDAY/... FRIDAY WE WILL DEALING WITH THE LAST VESTIGES OF A CYCLONIC FLOW REGIME...WITH POTENTIALLY ONE FINAL WEAK DISTURBANCE ROTATING AROUND THE WESTERN PERIPHERY OF AN UPPER LOW OVER THE CANADIAN MARITIMES. SO WILL MENTION JUST SLIGHT CHANCE POPS FOR WESTERN NEW ENGLAND...BEFORE TRANQUIL CONDITIONS DEVELOP FRIDAY NIGHT AS THE FLOW STARTS TO BECOME MORE ANTICYCLONIC. THE WEEKEND LOOKS TO FEATURE PLENTY OF SUNSHINE AND SEASONABLE TEMPERATURES...AS A RIDGE OF HIGH PRESSURE BOTH AT THE SURFACE AND ALOFT BECOMES ESTABLISHED ACROSS THE REGION. THE 00Z GFS IS ACTUALLY DEVELOPING SOME CONVECTION ON SUNDAY UNDERNEATH THE RIDGE...WHICH IN THE ABSENCE OF ANY SIGNIFICANT MOISTURE AND INSTABILITY LOOKS RATHER SUSPECT. WILL LEAN TOWARD THE 00Z ECMWF WHICH IS INDICATING RAIN-FREE CONDITIONS UNDER THE RIDGE. QUIET WEATHER SHOULD CONTINUE INTO EARLY NEXT WEEK WITH THE RIDGE STILL EXPECTED TO BE IN PLACE ACROSS THE NORTHEAST CONUS. && .AVIATION /15Z TUESDAY THROUGH SATURDAY/... SATELLITE PICTURES SHOW RADIATION FOG IN MANY OF THE VALLEYS OF EASTERN NEW YORK AND WESTERN NEW ENGLAND. VARIOUS WEB CAMS AROUND THE AREA SHOW THE FOG STEADILY BURNING OFF. MOST OF THE FOG SHOULD BE GONE FROM THE TAF SITES BY 13Z EXCEPT KPSF WHERE IT MAY LINGER UNTIL 14Z. VFR CONDITIONS EXPECTED FOR MOST OF THE DAYLIGHT HOURS. A DISTURBANCE MOVING THROUGH COULD TRIGGER SCATTERED THUNDERSTORMS THIS AFTERNOON...SO HAVE PLACED VCSH IN ALL TAFS STARTING AROUND 19Z OR 20Z. THUNDERSTORMS COULD PRODUCE SOME MVFR AT TAF SITES BUT COVERAGE IS NOT EXPECTED TO BE WIDESPREAD ENOUGH TO PUT THUNDERSTORMS IN THE TAFS. THESE STORMS SHOULD DISSIPATE AFTER SUNSET...WITH SOME PATCHY VALLEY FOG RETURNING WEDNESDAY MORNING. WINDS ARE FORECAST TO BE FROM THE WEST TODAY AND TONIGHT AT 5 TO 15 KNOTS. OUTLOOK... WEDNESDAY NIGHT: SLIGHT CHANCE OF SHRA. THURSDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX. FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SUNDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .FIRE WEATHER... A SLOW MOVING COLD FRONT APPROACHING FROM SOUTHERN CANADA WILL BRING A CHANCE FOR THUNDERSTORMS ACROSS MUCH OF THE AREA ON TUESDAY AND WEDNESDAY BEFORE CLEARING THE REGION. MINIMUM RELATIVE HUMIDITIES THIS AFTERNOON AND TOMORROW AFTERNOON SHOULD RANGE IN THE 40 TO 55 PERCENT RANGE. NIGHTTIME RH VALUES SHOULD BE 70 TO 100 PERCENT. WINDS WILL BE WEST TO NORTHWEST AT 15 MPH OR LESS THROUGH THE PERIOD. && .HYDROLOGY... SCATTERED SHOWERS AND THUNDERSTORMS CAN BE EXPECTED EACH AFTERNOON AND EVENING THROUGH WEDNESDAY ASSOCIATED WITH AN ADVANCING COLD FRONT. THE THREAT OF ISOLATED FLOODING OF POOR DRAINAGE AND URBAN AREAS WILL CONTINUE THIS AFTERNOON THROUGH WEDNESDAY... MAINLY IF THUNDERSTORMS REPEATEDLY PASS OVER THE SAME LOCATIONS. DUE TO THE CONVECTIVE NATURE OF THE RAINFALL...MOST RIVER BASINS WILL NOT EXPERIENCE MUCH IMPACT. SOME RISES MAY OCCUR FOR AREAS THAT SEE REPEATED RAINFALL THROUGH MIDWEEK. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...NAS NEAR TERM...SND/IRL SHORT TERM...NAS LONG TERM...JPV AVIATION...SND/JPV FIRE WEATHER...NAS HYDROLOGY...NAS
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1051 AM CDT TUE AUG 5 2014 .DISCUSSION... 1013 AM CDT NO BIG CHANGES TO GOING FORECAST FOR TODAY. VISIBLE SATELLITE IMAGERY SHOWS FAIRLY EXTENSIVE STRATUS ACROSS THE CWA THIS MORNING. THE HIGH SUN ANGLE AND LACK OF LOW LEVEL INVERSION TO TRAP THIS MOISTURE WOULD SUGGEST THAT IT SHOULD MIX OUT THIS AFTERNOON WITH AT LEAST PARTIAL CLEARING. GIVEN THE ANTICIPATED SUNSHINE MADE NO CHANGES TO GOING HIGH TEMP FORECAST FOR TODAY...BUT DID SLOW THE TEMP RISE IN THE HOURLY GRIDS INTO EARLY AFTERNOON DUE TO THE CLOUDINESS. ILL DEFINED COLD FRONT WILL CONTINUE SAG SLOWLY SOUTH ACROSS THE AREA THIS AFTERNOON...BUT LOW LEVEL CONVERGENCE ALONG THE FRONT WILL BE QUITE WEAK AND WATER VAPOR IMAGERY AND MODEL GUIDANCE DO NOT SHOW ANY UPSTREAM SHORTWAVES TO ENHANCE LARGE SCALE ASCENT. DESPITE THESE NEGATIVES...MODIFYING THE ILX 12Z SOUNDING FOR EXPECTED AFTERNOON CONDITIONS YIELDS SEVERAL HUNDRED JOULES OF MLCAPE WITH LITTLE INHIBITION...SO STILL POSSIBLE THAT ISOLATED SHRA/TSRA COULD DEVELOP OVER SOUTHEAST CWA THIS AFTERNOON. IZZI //PREV DISCUSSION... 355 AM CDT FORECAST CONCERNS FOCUS ON RAIN AND THUNDER CHANCES DIMINISHING FROM THE NORTH TODAY AS WEAK COLD FRONT CONTINUES TO SAG SOUTH ACROSS THE FORECAST AREA...AND AGAIN WEDNESDAY INTO THURSDAY AS ANOTHER SHORT WAVE AND JET STREAK DIG SOUTHEAST ACROSS THE REGION. AREA OF RAIN/THUNDERSTORMS HAS PUSHED SOUTHEAST ACROSS THE FORECAST AREA SINCE YESTERDAY AFTERNOON IN ASSOCIATION WITH A WEAK COLD FRONT AND A DIGGING MID-LEVEL SHORT WAVE TROUGH. MOST OF THE RAIN WAS SOUTHEAST OF A PRINCETON ILLINOIS TO GARY INDIANA LINE AS OF 3 AM AND SHOULD CONTINUE TO FOCUS OVER THE SOUTHEAST THIRD OR SO OF THE CWA THIS MORNING AS THE MID-LEVEL WAVE AND AN EMBEDDED MCV PROPAGATE INTO INDIANA. HARD TO PLACE THE ACTUAL COLD FRONTAL BOUNDARY GIVEN LIGHT GRADIENT AND CONVECTIVE OUTFLOW CONTAMINATED SURFACE WIND FIELD...THOUGH IT APPEARS TO BE SOMEWHERE FROM NORTH OF KORD TO KDKB TO SOUTH OF KSQI IN LATEST SURFACE ANALYSIS. FRONT IS PROGGED TO CONTINUE TO DRIFT SOUTHEAST THIS MORNING BEHIND WEAK SURFACE WAVE WITH BEST POTENTIAL FOR DIURNAL SHOWER/THUNDERSTORM DEVELOPMENT LATER THIS MORNING AND THIS AFTERNOON TO BE ALONG/SOUTH OF THE FRONT ACROSS THE SOUTH/SOUTHEAST PART OF THE CWA. ALSO...WITH LITTLE PUSH TO THE FRONT AT THIS TIME...LOW STRATUS AND FOG WAS DEVELOPING INTO NORTHWEST AND NORTH CENTRAL IL...AND WILL LIKELY LINGER AFTER SUNRISE THIS MORNING. SOMEWHAT DRIER LOW LEVEL AIR WILL FILTER IN FROM THE NORTH BY TONIGHT AS HIGH PRESSURE SPREADS ACROSS THE NORTHERN GREAT LAKES REGION...AND THE FRONT MOVES INTO DOWNSTATE IL/IN. GUIDANCE IS IN GOOD AGREEMENT IN DIGGING ANOTHER SHORT WAVE ACROSS THE MIDWEST WEDNESDAY INTO THURSDAY HOWEVER...WITH OVERRUNNING OF THE LOW LEVEL FRONTAL ZONE DEVELOPING FROM NORTHWEST IOWA INTO CENTRAL ILLINOIS. MODEL TREND HAS BEEN TO DEVELOP FAIRLY STRONG FRONTOGENESIS ALONG THE ELEVATED BAROCLINIC ZONE BENEATH THE RIGHT ENTRANCE REGION OF A 90 KT UPPER JET STREAK THROUGH THURSDAY...BRINGING A COUPLE OF PERIODS OF RAIN AND THUNDERSTORMS BACK INTO THE FORECAST AREA FROM WEDNESDAY MORNING THROUGH THURSDAY NIGHT. THE POTENTIAL EXISTS FOR SOME LOCALLY HEAVY RAINFALL THURSDAY/THURSDAY NIGHT ACROSS SOUTHERN PARTS OF THE CWA...AS 2+ INCH PWATS SPREAD NORTH. GFS/WRF BOTH DELIVER MORE THAN AN INCH OF RAIN TO THE SOUTHERN CWA DURING THIS TIME. FRONTAL ZONE THEN SHIFTS SOUTH INTO THE OHIO VALLEY AS HIGH PRESSURE STRENGTHENS ACROSS THE NORTHERN GREAT LAKES REGION FRIDAY AND SATURDAY. EASTERLY LOW LEVEL FLOW AROUND THE HIGH FAVORS DRY WEATHER AND PREFER THE DRIER ECMWF SOLUTION FOR THIS PERIOD. ANOTHER UPPER TROUGH APPROACHES THE REGION BY MONDAY HOWEVER...WITH AN INCREASE IN RAIN CHANCES LATER SUNDAY INTO MONDAY. TEMPERATURES THROUGH THE FORECAST PERIOD WILL AVERAGE JUST A BIT BELOW NORMAL WITH THE COOLEST DAYS WEDNESDAY-THURSDAY REMAINING IN THE 70S. OTHERWISE AROUND 80/LOWER 80S APPEAR REASONABLE. SURFACE FLOW WILL BE OFF THE LAKE THROUGH MOST OF THE PERIOD KEEPING AREAS NEAR LAKE MICHIGAN A LITTLE COOLER. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 16Z... * WINDS INCREASING TO AROUND 10KT DURING THE MID-AFTERNOON. * MVFR CEILINGS LINGERING POSSIBLY THROUGH EARLY AFTERNOON. * FOG POSSIBLE ONCE AGAIN TONIGHT. RODRIGUEZ/MTF //DISCUSSION...UPDATED 12Z... RADAR IMAGERY DEPICTING LAST AREA OF SHOWERS EXITING TO THE EAST OF THE TERMINALS THIS MORNING...WHILE WEAK SURFACE TROUGH AND FRONT REMAIN SITUATED ACROSS THE AREA. WITHIN THIS WEAK SURFACE PATTERN...FOG AND LOW STRATUS HAVE DEVELOPED EARLY THIS MORNING. SOLID IFR CEILINGS ARE CURRENTLY SITUATED MORE TOWARDS FAR NORTHERN ILLINOIS AT THIS HOUR...WITH MVFR CEILINGS LOCATED OVER NORTHEAST ILLINOIS. WHILE RFD OBSERVES IFR OVER THE NEXT SEVERAL HOURS...EXPECT THE REMAINING SITES TO ONLY OBSERVE MVFR CEILINGS. A SLOW UPWARD TREND IN THESE CEILINGS WILL LIKELY OCCUR BEFORE THEY SCATTER BY MID/LATE MORNING. SURFACE TROUGH/FRONT WILL PUSH THROUGH LATER THIS MORNING WITH THE CURRENT LIGHT/VARIABLE WINDS BECOMING MORE NORTHEAST. DO THINK THERE WILL BE AN INCREASE IN SPEEDS BY EARLY AFTERNOON...AS AN EXTRA LAKE PUSH OCCURS. OVERALL PRECIP CHANCES APPEAR TO BE LOW BUT COULD SEE SOME ISOLATED SHOWER DEVELOPMENT WITH THIS ADDED LAKE PUSH THIS AFTERNOON. WITH LOW CONFIDENCE...HAVE OPTED TO LEAVE OUT ANY MENTION OF PRECIP AT THIS TIME. OUTSIDE OF SOME PATCHY FOG ONCE AGAIN TONIGHT...EXPECT VFR CONDITIONS TO BE IN PLACE FOR THE REMAINDER OF THE FORECAST PERIOD AS NEXT CHANCE FOR PRECIP FOR THE AREA ON WEDNESDAY WILL REMAIN JUST SOUTH OF ALL THE TERMINALS. RODRIGUEZ //ORD AND MDW CONFIDENCE...UPDATED 16Z... * MEDIUM IN SPEED OF NORTHEAST WINDS REACHING 10 KT AT 20Z. * MEDIUM WITH CEILING THROUGH EARLY AFTERNOON. * LOW IN FOG REDEVELOPMENT TONIGHT. RODRIGUEZ/MTF //OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z... WEDNESDAY NIGHT...VFR. THURSDAY...SLIGHT CHANCE OF TSRA. FRIDAY...VFR. SATURDAY...VFR. SUNDAY...SLIGHT CHANCE OF TSRA. MONDAY...CHANCE OF TSRA. RODRIGUEZ && .MARINE... 434 AM CDT AS A WEAK SURFACE TROUGH OF LOW PRESSURE AND ASSOCIATED FRONTAL BOUNDARY STRETCHED FROM THE CENTRAL PLAINS AND MID MISSISSIPPI VALLEY TO THE SOUTHERN PORTIONS OF THE LAKE CONTINUE TO SLOWLY MOVE TO THE SOUTHEAST TODAY...THE VARIABLE WINDS CURRENTLY BEING OBSERVED OVER THE SOUTHERN END OF THE LAKE WILL BECOME MORE NORTHERLY THIS MORNING LIKE THE REMAINDER OF THE LAKE. DO EXPECT THESE NORTHERLY WINDS TO INCREASE TO THE 10 TO 20 KT RANGE TODAY...WHILE WAVES ALSO BUILD TO 2 TO 4 FEET. THIS INCREASE IN SPEEDS WILL BE BRIEF THOUGH AS WINDS DIMINISH TONIGHT AND THEN REMAIN ON THE LIGHTER SIDE THROUGH THE REST OF THE FORECAST PERIOD...AS HIGH PRESSURE TO THE NORTHWEST SETTLES IN THROUGH THE REST OF THE WORK WEEK. RODRIGUEZ && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
  [top] Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 1043 AM CDT Tue Aug 5 2014 .UPDATE... ISSUED AT 1030 AM CDT TUE AUG 5 2014 Will update the forecast today to adjust sky cover with more low clouds from Peoria north into midday. Will continue 20-30% chances of showers and thunderstorms over eastern IL this afternoon. Seasonably warm highs in the mid 80s over much of CWA with upper 80s near Lawrenceville and Robinson by Wabash river valley. Rather humid today with dewpoints in the mid 60s to near 70F with lowest dewpoints in southeast IL. Short wave that brought locally heavy rains of 1.5-3.5 inches around the Peoria metro area last night has shifted east and south of central IL late this morning. Showers and isolated thunderstorms have exited southeast IL during mid morning so by late morning ILX CWA is dry. Low clouds of 500-1200 feet from Peoria north while patches of clouds above 3k ft over eastern IL from I-57 east. 10 am temps range from near 70F far ne CWA by Lacon and Danville where clouds prevail, to upper 70s from Springfield sw where more sunshine this morning. Dewpoints range from mid 60s over eastern IL to near 70F from Macomb to Springfield west. A frontal boundary just se of the IL river will continue to press slowly se into southeast IL later today. Even though we are on back side of short wave exiting se of IL today, the boundary could develop isolated convection this afternoon as it pushes through areas se of I-55. SPC has 5% risk of severe storms this afternoon and into tonight over Nebraska and western IA and then has 5% risk of severe hail/wind over central IL Wed afternoon/evening and slight chance of severe storms (15% of large hail and damaging wind gusts) sw of a Canton to Lincoln line. HUETTL && .SHORT TERM...Today through Thursday Scattered showers associated with a short-wave trough will continue to work their way east/southeast across the KILX CWA early this morning. Most of the precip will be east of the I-55 corridor by 12z, then into Indiana by 18z as trough passes to the east. Subsidence on the back side of the wave should lead to a mostly dry afternoon, although HRRR is hinting that a few additional showers may fire across the E/NE during the afternoon. Will go with isolated to scattered wording for today, as areal coverage will be rather limited. Morning clouds will gradually clear, with partly sunny conditions expected later in the day. Will be another warm/humid day with highs once again reaching the middle 80s. A lull in the precip chances will occur this afternoon through the evening as short-wave ridging prevails. The next in a series of waves will begin to approach from the northwest overnight, with all model solutions showing a large area of showers/thunder developing along/north of a stalled frontal boundary draped across Iowa. Precip will begin to push into the Illinois River Valley toward dawn Wednesday, so will carry low chance PoPs after midnight along/northwest of the Illinois River with dry conditions elsewhere. Showers and thunderstorms will spread across much of central Illinois on Wednesday, primarily impacting locations west of the I-57 corridor. Will carry likely PoPs across the west, tapering down to low chance along the Indiana border accordingly. SPC has indicated that a slight risk for severe storms may develop Wednesday afternoon and evening across northern Missouri into southwest Illinois. This severe risk is contingent upon vigorous short-wave currently over Utah maintaining its strength as it approaches from the west Wednesday evening. NAM remains most aggressive with this feature, while GFS is quite a bit weaker. If stronger NAM verifies, enough lift will be generated along/south of surface boundary within the unstable and moderately sheared airmass to support a few strong to severe storms with large hail/gusty winds across the southwest CWA Wednesday evening. Otherwise, expect showers and thunderstorms to become more numerous across the entire area Wednesday night into Thursday as upper wave tracks across the area and interacts with the stalled frontal boundary and very moist airmass. .LONG TERM...Friday through Monday Once the Thursday wave passes to the east, frontal boundary will begin to get pushed southward by the end of the week. Models continue to struggle with this evolution, but general consensus shifts best precip chances into the Ohio River Valley on Friday, then even further south over the weekend. As a result, will focus chance PoPs across only the southern CWA on Friday. After that, Saturday and Sunday appear to be largely dry before the next potential wave approaches within the prevailing northwesterly flow pattern early next week. Will therefore go with a dry forecast during the weekend, with low chance PoPs returning by Monday. BARNES && .AVIATION... ISSUED 630 AM CDT Tue Aug 5 2014 Challenging forecast thru late morning as copious low level moisture left over from last night`s rainfall and light wind flow will create variable conditions with respect to vsbys and cigs thru the morning. Watching a band of stratus drifting south out of northern Illinois which may affect the PIA and BMI terminals this morning. After that, forecast soundings indicate we may see some MVFR cigs for a time into early this afternoon, especially from KPIA to KBMI and possibly into KCMI. Based on the sounding data, cigs in the 2500-3500 foot range will be possible before we trend towards scattered bases around 4000 feet aftr 19z. Confidence on this scenario rather low as lower cloud deck appears to be breaking up some as it tracks south early this morning. Winds once again a non-factor although we will see a frontal boundary slip south of the area switching the wind direction more into a north to northeast direction later this morning into the afternoon hours. Some mid to high level clouds will be the story for tonight with some fog/hz developing again later in the evening. SMITH && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...HUETTL LONG TERM...BARNES AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
849 AM CDT TUE AUG 5 2014 .DISCUSSION... 355 AM CDT FORECAST CONCERNS FOCUS ON RAIN AND THUNDER CHANCES DIMINISHING FROM THE NORTH TODAY AS WEAK COLD FRONT CONTINUES TO SAG SOUTH ACROSS THE FORECAST AREA...AND AGAIN WEDNESDAY INTO THURSDAY AS ANOTHER SHORT WAVE AND JET STREAK DIG SOUTHEAST ACROSS THE REGION. AREA OF RAIN/THUNDERSTORMS HAS PUSHED SOUTHEAST ACROSS THE FORECAST AREA SINCE YESTERDAY AFTERNOON IN ASSOCIATION WITH A WEAK COLD FRONT AND A DIGGING MID-LEVEL SHORT WAVE TROUGH. MOST OF THE RAIN WAS SOUTHEAST OF A PRINCETON ILLINOIS TO GARY INDIANA LINE AS OF 3 AM AND SHOULD CONTINUE TO FOCUS OVER THE SOUTHEAST THIRD OR SO OF THE CWA THIS MORNING AS THE MID-LEVEL WAVE AND AN EMBEDDED MCV PROPAGATE INTO INDIANA. HARD TO PLACE THE ACTUAL COLD FRONTAL BOUNDARY GIVEN LIGHT GRADIENT AND CONVECTIVE OUTFLOW CONTAMINATED SURFACE WIND FIELD...THOUGH IT APPEARS TO BE SOMEWHERE FROM NORTH OF KORD TO KDKB TO SOUTH OF KSQI IN LATEST SURFACE ANALYSIS. FRONT IS PROGGED TO CONTINUE TO DRIFT SOUTHEAST THIS MORNING BEHIND WEAK SURFACE WAVE WITH BEST POTENTIAL FOR DIURNAL SHOWER/THUNDERSTORM DEVELOPMENT LATER THIS MORNING AND THIS AFTERNOON TO BE ALONG/SOUTH OF THE FRONT ACROSS THE SOUTH/SOUTHEAST PART OF THE CWA. ALSO...WITH LITTLE PUSH TO THE FRONT AT THIS TIME...LOW STRATUS AND FOG WAS DEVELOPING INTO NORTHWEST AND NORTH CENTRAL IL...AND WILL LIKELY LINGER AFTER SUNRISE THIS MORNING. SOMEWHAT DRIER LOW LEVEL AIR WILL FILTER IN FROM THE NORTH BY TONIGHT AS HIGH PRESSURE SPREADS ACROSS THE NORTHERN GREAT LAKES REGION...AND THE FRONT MOVES INTO DOWNSTATE IL/IN. GUIDANCE IS IN GOOD AGREEMENT IN DIGGING ANOTHER SHORT WAVE ACROSS THE MIDWEST WEDNESDAY INTO THURSDAY HOWEVER...WITH OVERRUNNING OF THE LOW LEVEL FRONTAL ZONE DEVELOPING FROM NORTHWEST IOWA INTO CENTRAL ILLINOIS. MODEL TREND HAS BEEN TO DEVELOP FAIRLY STRONG FRONTOGENESIS ALONG THE ELEVATED BAROCLINIC ZONE BENEATH THE RIGHT ENTRANCE REGION OF A 90 KT UPPER JET STREAK THROUGH THURSDAY...BRINGING A COUPLE OF PERIODS OF RAIN AND THUNDERSTORMS BACK INTO THE FORECAST AREA FROM WEDNESDAY MORNING THROUGH THURSDAY NIGHT. THE POTENTIAL EXISTS FOR SOME LOCALLY HEAVY RAINFALL THURSDAY/THURSDAY NIGHT ACROSS SOUTHERN PARTS OF THE CWA...AS 2+ INCH PWATS SPREAD NORTH. GFS/WRF BOTH DELIVER MORE THAN AN INCH OF RAIN TO THE SOUTHERN CWA DURING THIS TIME. FRONTAL ZONE THEN SHIFTS SOUTH INTO THE OHIO VALLEY AS HIGH PRESSURE STRENGTHENS ACROSS THE NORTHERN GREAT LAKES REGION FRIDAY AND SATURDAY. EASTERLY LOW LEVEL FLOW AROUND THE HIGH FAVORS DRY WEATHER AND PREFER THE DRIER ECMWF SOLUTION FOR THIS PERIOD. ANOTHER UPPER TROUGH APPROACHES THE REGION BY MONDAY HOWEVER...WITH AN INCREASE IN RAIN CHANCES LATER SUNDAY INTO MONDAY. TEMPERATURES THROUGH THE FORECAST PERIOD WILL AVERAGE JUST A BIT BELOW NORMAL WITH THE COOLEST DAYS WEDNESDAY-THURSDAY REMAINING IN THE 70S. OTHERWISE AROUND 80/LOWER 80S APPEAR REASONABLE. SURFACE FLOW WILL BE OFF THE LAKE THROUGH MOST OF THE PERIOD KEEPING AREAS NEAR LAKE MICHIGAN A LITTLE COOLER. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 14Z... * WINDS BECOMING LIGHT NORTHEAST BY 15Z...LIKELY INCREASING TO 10KT OR HIGHER DURING THE EARLY AFTERNOON. * MVFR CEILINGS THIS MORNING. * LOW CHANCE FOR A BRIEF SHOWER THIS AFTERNOON. * FOG POSSIBLE ONCE AGAIN TONIGHT. RODRIGUEZ/MTF //DISCUSSION...UPDATED 12Z... RADAR IMAGERY DEPICTING LAST AREA OF SHOWERS EXITING TO THE EAST OF THE TERMINALS THIS MORNING...WHILE WEAK SURFACE TROUGH AND FRONT REMAIN SITUATED ACROSS THE AREA. WITHIN THIS WEAK SURFACE PATTERN...FOG AND LOW STRATUS HAVE DEVELOPED EARLY THIS MORNING. SOLID IFR CEILINGS ARE CURRENTLY SITUATED MORE TOWARDS FAR NORTHERN ILLINOIS AT THIS HOUR...WITH MVFR CEILINGS LOCATED OVER NORTHEAST ILLINOIS. WHILE RFD OBSERVES IFR OVER THE NEXT SEVERAL HOURS...EXPECT THE REMAINING SITES TO ONLY OBSERVE MVFR CEILINGS. A SLOW UPWARD TREND IN THESE CEILINGS WILL LIKELY OCCUR BEFORE THEY SCATTER BY MID/LATE MORNING. SURFACE TROUGH/FRONT WILL PUSH THROUGH LATER THIS MORNING WITH THE CURRENT LIGHT/VARIABLE WINDS BECOMING MORE NORTHEAST. DO THINK THERE WILL BE AN INCREASE IN SPEEDS BY EARLY AFTERNOON...AS AN EXTRA LAKE PUSH OCCURS. OVERALL PRECIP CHANCES APPEAR TO BE LOW BUT COULD SEE SOME ISOLATED SHOWER DEVELOPMENT WITH THIS ADDED LAKE PUSH THIS AFTERNOON. WITH LOW CONFIDENCE...HAVE OPTED TO LEAVE OUT ANY MENTION OF PRECIP AT THIS TIME. OUTSIDE OF SOME PATCHY FOG ONCE AGAIN TONIGHT...EXPECT VFR CONDITIONS TO BE IN PLACE FOR THE REMAINDER OF THE FORECAST PERIOD AS NEXT CHANCE FOR PRECIP FOR THE AREA ON WEDNESDAY WILL REMAIN JUST SOUTH OF ALL THE TERMINALS. RODRIGUEZ //ORD AND MDW CONFIDENCE...UPDATED 14Z... * MEDIUM IN SPEED OF NORTHEAST WINDS REACHING 10 KT AT 19Z. * MEDIUM WITH CEILING TRENDS THIS MORNING. * LOW IN ANY SHOWERS THIS AFTERNOON. * LOW IN FOG REDEVELOPMENT TONIGHT. RODRIGUEZ/MTF //OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z... WEDNESDAY NIGHT...VFR. THURSDAY...SLIGHT CHANCE OF TSRA. FRIDAY...VFR. SATURDAY...VFR. SUNDAY...SLIGHT CHANCE OF TSRA. MONDAY...CHANCE OF TSRA. RODRIGUEZ && .MARINE... 434 AM CDT AS A WEAK SURFACE TROUGH OF LOW PRESSURE AND ASSOCIATED FRONTAL BOUNDARY STRETCHED FROM THE CENTRAL PLAINS AND MID MISSISSIPPI VALLEY TO THE SOUTHERN PORTIONS OF THE LAKE CONTINUE TO SLOWLY MOVE TO THE SOUTHEAST TODAY...THE VARIABLE WINDS CURRENTLY BEING OBSERVED OVER THE SOUTHERN END OF THE LAKE WILL BECOME MORE NORTHERLY THIS MORNING LIKE THE REMAINDER OF THE LAKE. DO EXPECT THESE NORTHERLY WINDS TO INCREASE TO THE 10 TO 20 KT RANGE TODAY...WHILE WAVES ALSO BUILD TO 2 TO 4 FEET. THIS INCREASE IN SPEEDS WILL BE BRIEF THOUGH AS WINDS DIMINISH TONIGHT AND THEN REMAIN ON THE LIGHTER SIDE THROUGH THE REST OF THE FORECAST PERIOD...AS HIGH PRESSURE TO THE NORTHWEST SETTLES IN THROUGH THE REST OF THE WORK WEEK. RODRIGUEZ && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 641 AM CDT Tue Aug 5 2014 .DISCUSSION... ISSUED 309 AM CDT Tue Aug 5 2014 SHORT TERM...Today through Thursday Scattered showers associated with a short-wave trough will continue to work their way east/southeast across the KILX CWA early this morning. Most of the precip will be east of the I-55 corridor by 12z, then into Indiana by 18z as trough passes to the east. Subsidence on the back side of the wave should lead to a mostly dry afternoon, although HRRR is hinting that a few additional showers may fire across the E/NE during the afternoon. Will go with isolated to scattered wording for today, as areal coverage will be rather limited. Morning clouds will gradually clear, with partly sunny conditions expected later in the day. Will be another warm/humid day with highs once again reaching the middle 80s. A lull in the precip chances will occur this afternoon through the evening as short-wave ridging prevails. The next in a series of waves will begin to approach from the northwest overnight, with all model solutions showing a large area of showers/thunder developing along/north of a stalled frontal boundary draped across Iowa. Precip will begin to push into the Illinois River Valley toward dawn Wednesday, so will carry low chance PoPs after midnight along/northwest of the Illinois River with dry conditions elsewhere. Showers and thunderstorms will spread across much of central Illinois on Wednesday, primarily impacting locations west of the I-57 corridor. Will carry likely PoPs across the west, tapering down to low chance along the Indiana border accordingly. SPC has indicated that a slight risk for severe storms may develop Wednesday afternoon and evening across northern Missouri into southwest Illinois. This severe risk is contingent upon vigorous short-wave currently over Utah maintaining its strength as it approaches from the west Wednesday evening. NAM remains most aggressive with this feature, while GFS is quite a bit weaker. If stronger NAM verifies, enough lift will be generated along/south of surface boundary within the unstable and moderately sheared airmass to support a few strong to severe storms with large hail/gusty winds across the southwest CWA Wednesday evening. Otherwise, expect showers and thunderstorms to become more numerous across the entire area Wednesday night into Thursday as upper wave tracks across the area and interacts with the stalled frontal boundary and very moist airmass. LONG TERM...Friday through Monday Once the Thursday wave passes to the east, frontal boundary will begin to get pushed southward by the end of the week. Models continue to struggle with this evolution, but general consensus shifts best precip chances into the Ohio River Valley on Friday, then even further south over the weekend. As a result, will focus chance PoPs across only the southern CWA on Friday. After that, Saturday and Sunday appear to be largely dry before the next potential wave approaches within the prevailing northwesterly flow pattern early next week. Will therefore go with a dry forecast during the weekend, with low chance PoPs returning by Monday. && .AVIATION... ISSUED 630 AM CDT Tue Aug 5 2014 Challenging forecast thru late morning as copious low level moisture left over from last night`s rainfall and light wind flow will create variable conditions with respect to vsbys and cigs thru the morning. Watching a band of stratus drifting south out of northern Illinois which may affect the PIA and BMI terminals this morning. After that, forecast soundings indicate we may see some MVFR cigs for a time into early this afternoon, especially from KPIA to KBMI and possibly into KCMI. Based on the sounding data, cigs in the 2500-3500 foot range will be possible before we trend towards scattered bases around 4000 feet aftr 19z. Confidence on this scenario rather low as lower cloud deck appears to be breaking up some as it tracks south early this morning. Winds once again a non-factor although we will see a frontal boundary slip south of the area switching the wind direction more into a north to northeast direction later this morning into the afternoon hours. Some mid to high level clouds will be the story for tonight with some fog/hz developing again later in the evening. Smith && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1025 AM EDT TUE AUG 5 2014 .UPDATE... AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 359 AM EDT TUE AUG 5 2014 A COLD FRONT MOVING INTO THE AREA WILL BRING CHANCES FOR THUNDERSTORMS TO CENTRAL INDIANA TODAY. THIS FRONT WILL STALL SOMEWHERE IN THE AREA AND UPPER WAVES WILL INTERACT WITH IT THROUGH THE REST OF THE WEEK KEEPING THUNDERSTORM CHANCES IN THE FORECAST. NEAR NORMAL TEMPERATURES WILL TAKE A SMALL DIP IN THE WAKE OF THE COLD FRONTAL PASSAGE WEDNESDAY AND THURSDAY BEFORE REBOUNDING TO NORMAL FROM THURSDAY ON. && .NEAR TERM /REST OF TODAY/... ISSUED AT 929 AM EDT TUE AUG 5 2014 UPPED POPS TO LIKELY IN THE EXTREME WEST THIS MORNING BASED ON CURRENT RADAR TRENDS AND UPPED THEM TO HIGH END OF CHANCE CATEGORY FOR MUCH OF THE REMAINDER OF THE WEST. RAIN IS GENERALLY DIMINISHING AS IT MOVES EAST SO KEPT LOWER POPS EAST. AS UPPER WAVE MOVES EAST LATER THIS MORNING SUPPORT FOR CONVECTION WEAKENS...AND LATEST HI RES MODELS ARE SHOWING LITTLE DEVELOPMENT THIS AFTERNOON. HOWEVER STILL THINK POTENTIAL IS THERE FOR SCATTERED DEVELOPMENT WITH THE EXPECTED AFTERNOON INSTABILITY. THUS GENERALLY KEPT POPS THE SAME THIS AFTERNOON...BUT LOWERED JUST A BIT FROM THE HIGH END CHANCE CATEGORY NORTHEAST DUE TO THE WEAKER SUPPORT. PREVIOUS DISCUSSION FOLLOWS... RADAR MOSAIC SHOWS SHOWERS AND THUNDERSTORMS MOVING INTO THE NORTHWESTERN COUNTIES BUT SHRINKING AS THEY DO. THESE WILL SLOWLY MOVE IN BUT COVERAGE WILL BE LESS AND LESS BASED ON CURRENT TRENDS. THUS KEPT POPS AT CHANCE/SCATTERED OR LESS FOR THE REST OF THE EARLY MORNING. AFTER THAT SHORT TERM MODELS ARE SHOWING EVEN LESS COVERAGE BUT PERHAPS AN INCREASE AGAIN IN THE AFTERNOON. TRIED TO TIME THE POPS FOR THE TODAY PERIOD WITH THE MOVEMENT OF THE UPPER WAVE AND KEPT THE HIGHEST POPS ACROSS THE NORTH. BROUGHT A SLIGHT CHANCE IN ACROSS THE SOUTH FOR THE AFTERNOON INSTEAD OF KEEPING THINGS DRY WITH RAP SHOWING SOME DEVELOPMENT THERE AS WELL BUT THE BEST FORCING STAYING FAR FROM THERE. FOR TEMPERATURES THOUGHT THE CONSENSUS NUMBERS DID A GOOD JOB. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/... ISSUED AT 359 AM EDT TUE AUG 5 2014 FOR TONIGHT CONTINUED WITH SOME POPS AS A CARRYOVER FROM TODAY AS THE UPPER WAVE WILL BE MOVING OUT. BY LATE TONIGHT WENT DRY WITH LITTLE FORCING PRESENT. FOR WEDNESDAY MODELS HAVE TRENDED DRIER THIS RUN. NOT READY TO BUY THIS FULL ON SINCE LAST NIGHT/S RUNS HAD WEDNESDAY LOOKING FAIRLY WET. THUS BLENDED PREVIOUS AND CURRENT SOLUTIONS TO PROVIDE A COMPROMISE OF LOW CHANCE POPS ACROSS THE AREA. THE BEST FORCING WILL NOT BE ARRIVING UNTIL VERY LATE WEDNESDAY NIGHT INTO THURSDAY WITH A SHORTWAVE PROVIDING ADDITIONAL FORCING TO THE FRONT WHOSE EXACT POSITION IS STILL VARIABLE BETWEEN MODELS AND RUN-TO-RUN. WENT WITH THE HIGHEST POPS IN THE PERIOD ON THURSDAY WITH THE FORCING FROM THE UPPER WAVE. IF THE SURFACE FRONT SETS UP JUST TO THE SOUTH OR RIGHT ACROSS THE AREA HEAVY RAIN COULD BE A PROBLEM...BUT AT THIS POINT THE EXACT LOCATION OF THAT FRONT IS STILL VERY LOW CONFIDENCE. FOR TEMPERATURES THROUGH THE PERIOD GENERALLY USED A CONSENSUS. FOR THURSDAY/S HIGHS THOUGH WENT LOWER THAN THE MODEL AVERAGE TO REFLECT THE POTENTIAL FOR COOLER TEMPERATURES WITH THE HIGHER PROBABILITY FOR CLOUD COVER AND RAIN. && .LONG TERM /FRIDAY THROUGH MONDAY/... ISSUED AT 359 AM EDT TUE AUG 5 2014 THE THREAT FOR UNSETTLED WEATHER IS LIKELY TO PERSIST INTO THE WEEKEND AS NORTHWEST FLOW ALOFT REMAINS ACROSS THE REGION AND A FRONTAL BOUNDARY ALIGNS OVER THE TENNESSEE AND LOWER OHIO VALLEYS. 00Z MODEL SUITE HAS SHIFTED THE FRONT FURTHER NORTH FROM PREVIOUS RUNS...ESPECIALLY THE ECMWF AND OP GFS WHICH BOTH HAD MAINTAINED A MORE SUPPRESSED LOCATION TO THE BOUNDARY. DIFFERENCES REMAIN HOWEVER WITH RESPECT TO EVENTUAL LOCATION OF THE BOUNDARY BUT WITH A GENERAL CONSENSUS NOW PLACING IT JUST SOUTH OF THE REGION...CARRYING PRECIP CHANCES REMAINS WARRANTED INTO THE FIRST HALF OF THE WEEKEND. WILL PLACE HIGHEST POPS FRIDAY INTO EARLY SATURDAY OVER SOUTHERN COUNTIES AS A SURFACE WAVE RIDES ALONG THE BOUNDARY. WITH A DEEP MOIST AIRMASS IN PLACE FRIDAY/SATURDAY...HEAVY RAIN IS LIKELY TO ACCOMPANY STORMS. DRIER AIR ATTEMPTS TO MAKE A BRIEF APPEARANCE SATURDAY NIGHT WITH HIGH PRESSURE OVER THE NORTHERN GREAT LAKES...BUT THE ARRIVAL OF ADDITIONAL WAVES ALOFT AND THE REMNANT BOUNDARY LINGERING IN THE OHIO VALLEY SUPPORTS REINTRODUCING POPS INTO EARLY NEXT WEEK. TEMPERATURES WILL REMAIN SEASONABLE BUT CONTINUE TO RUN SLIGHTLY BELOW NORMAL THROUGH THE EXTENDED...WITH HIGHS RANGING FROM THE UPPER 70S TO MIDDLE 80S. && .AVIATION /DISCUSSION FOR 051500Z KIND TAF UPDATE/... ISSUED AT 1025 AM EDT TUE AUG 5 2014 MINOR TWEAKS MADE TO KIND TAF TO BETTER MATCH CURRENT CONDITIONS. NO OTHER CHANGES NEEDED AT THIS PORINT. PREVIOUS AVIATION DISCUSSION FOLLOWS... MVFR CONDITIONS POSSIBLE LATE TONIGHT...OTHERWISE VFR EXPECTED. WEAKENING AREA OF SHOWERS PROGRESSING INTO THE REGION THIS MORNING MAY BRIEFLY IMPACT ALL BUT KLAF. SHORT RANGE MODEL GUIDANCE CONTINUES TO WEAKEN AND DIMINISH THE PRECIP AREA BY LATE MORNING. EXPECT VFR CU DEVELOPMENT THIS AFTERNOON ALONG WITH SCATTERED CONVECTION AS A WEAK FRONTAL BOUNDARY DROPS INTO CENTRAL INDIANA. WILL CARRY VCTS AT KLAF THROUGH THE AFTERNOON WHERE FORCING ALOFT IS SOMEWHAT BETTER. CONFIDENCE IN CONVECTIVE TIMING AND COVERAGE REMAINS HIGHLY UNCERTAIN AT THE OTHER TERMINALS AND WILL KEEP THESE SITES DRY AT THIS TIME. SOUTHWEST WINDS AT 5 TO 10KTS EXPECTED THIS AFTERNOON. WINDS WILL BECOME LIGHT TONIGHT AS THEY VEER TO N/NW BEHIND THE BOUNDARY. MODEL SOUNDINGS INDICATING MID LEVEL CLOUDS LIKELY TO BECOME THE PREDOMINANT DECK AS THE NIGHT PROGRESSES WITH SLIGHTLY DRIER AIR WITHIN THE BOUNDARY LAYER NORTH OF THE BOUNDARY. COULD SEE MVFR FOG DEVELOP AT OUTLYING TERMINALS LATE. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...CP NEAR TERM...CP/50 SHORT TERM...CP LONG TERM....RYAN AVIATION...RYAN/JH VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSINDIANAPOLIS WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
929 AM EDT TUE AUG 5 2014 .UPDATE... THE NEAR TERM SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 359 AM EDT TUE AUG 5 2014 A COLD FRONT MOVING INTO THE AREA WILL BRING CHANCES FOR THUNDERSTORMS TO CENTRAL INDIANA TODAY. THIS FRONT WILL STALL SOMEWHERE IN THE AREA AND UPPER WAVES WILL INTERACT WITH IT THROUGH THE REST OF THE WEEK KEEPING THUNDERSTORM CHANCES IN THE FORECAST. NEAR NORMAL TEMPERATURES WILL TAKE A SMALL DIP IN THE WAKE OF THE COLD FRONTAL PASSAGE WEDNESDAY AND THURSDAY BEFORE REBOUNDING TO NORMAL FROM THURSDAY ON. && .NEAR TERM /REST OF TODAY/... ISSUED AT 929 AM EDT TUE AUG 5 2014 UPPED POPS TO LIKELY IN THE EXTREME WEST THIS MORNING BASED ON CURRENT RADAR TRENDS AND UPPED THEM TO HIGH END OF CHANCE CATEGORY FOR MUCH OF THE REMAINDER OF THE WEST. RAIN IS GENERALLY DIMINISHING AS IT MOVES EAST SO KEPT LOWER POPS EAST. AS UPPER WAVE MOVES EAST LATER THIS MORNING SUPPORT FOR CONVECTION WEAKENS...AND LATEST HI RES MODELS ARE SHOWING LITTLE DEVELOPMENT THIS AFTERNOON. HOWEVER STILL THINK POTENTIAL IS THERE FOR SCATTERED DEVELOPMENT WITH THE EXPECTED AFTERNOON INSTABILITY. THUS GENERALLY KEPT POPS THE SAME THIS AFTERNOON...BUT LOWERED JUST A BIT FROM THE HIGH END CHANCE CATEGORY NORTHEAST DUE TO THE WEAKER SUPPORT. PREVIOUS DISCUSSION FOLLOWS... RADAR MOSAIC SHOWS SHOWERS AND THUNDERSTORMS MOVING INTO THE NORTHWESTERN COUNTIES BUT SHRINKING AS THEY DO. THESE WILL SLOWLY MOVE IN BUT COVERAGE WILL BE LESS AND LESS BASED ON CURRENT TRENDS. THUS KEPT POPS AT CHANCE/SCATTERED OR LESS FOR THE REST OF THE EARLY MORNING. AFTER THAT SHORT TERM MODELS ARE SHOWING EVEN LESS COVERAGE BUT PERHAPS AN INCREASE AGAIN IN THE AFTERNOON. TRIED TO TIME THE POPS FOR THE TODAY PERIOD WITH THE MOVEMENT OF THE UPPER WAVE AND KEPT THE HIGHEST POPS ACROSS THE NORTH. BROUGHT A SLIGHT CHANCE IN ACROSS THE SOUTH FOR THE AFTERNOON INSTEAD OF KEEPING THINGS DRY WITH RAP SHOWING SOME DEVELOPMENT THERE AS WELL BUT THE BEST FORCING STAYING FAR FROM THERE. FOR TEMPERATURES THOUGHT THE CONSENSUS NUMBERS DID A GOOD JOB. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/... ISSUED AT 359 AM EDT TUE AUG 5 2014 FOR TONIGHT CONTINUED WITH SOME POPS AS A CARRYOVER FROM TODAY AS THE UPPER WAVE WILL BE MOVING OUT. BY LATE TONIGHT WENT DRY WITH LITTLE FORCING PRESENT. FOR WEDNESDAY MODELS HAVE TRENDED DRIER THIS RUN. NOT READY TO BUY THIS FULL ON SINCE LAST NIGHT/S RUNS HAD WEDNESDAY LOOKING FAIRLY WET. THUS BLENDED PREVIOUS AND CURRENT SOLUTIONS TO PROVIDE A COMPROMISE OF LOW CHANCE POPS ACROSS THE AREA. THE BEST FORCING WILL NOT BE ARRIVING UNTIL VERY LATE WEDNESDAY NIGHT INTO THURSDAY WITH A SHORTWAVE PROVIDING ADDITIONAL FORCING TO THE FRONT WHOSE EXACT POSITION IS STILL VARIABLE BETWEEN MODELS AND RUN-TO-RUN. WENT WITH THE HIGHEST POPS IN THE PERIOD ON THURSDAY WITH THE FORCING FROM THE UPPER WAVE. IF THE SURFACE FRONT SETS UP JUST TO THE SOUTH OR RIGHT ACROSS THE AREA HEAVY RAIN COULD BE A PROBLEM...BUT AT THIS POINT THE EXACT LOCATION OF THAT FRONT IS STILL VERY LOW CONFIDENCE. FOR TEMPERATURES THROUGH THE PERIOD GENERALLY USED A CONSENSUS. FOR THURSDAY/S HIGHS THOUGH WENT LOWER THAN THE MODEL AVERAGE TO REFLECT THE POTENTIAL FOR COOLER TEMPERATURES WITH THE HIGHER PROBABILITY FOR CLOUD COVER AND RAIN. && .LONG TERM /FRIDAY THROUGH MONDAY/... ISSUED AT 359 AM EDT TUE AUG 5 2014 THE THREAT FOR UNSETTLED WEATHER IS LIKELY TO PERSIST INTO THE WEEKEND AS NORTHWEST FLOW ALOFT REMAINS ACROSS THE REGION AND A FRONTAL BOUNDARY ALIGNS OVER THE TENNESSEE AND LOWER OHIO VALLEYS. 00Z MODEL SUITE HAS SHIFTED THE FRONT FURTHER NORTH FROM PREVIOUS RUNS...ESPECIALLY THE ECMWF AND OP GFS WHICH BOTH HAD MAINTAINED A MORE SUPPRESSED LOCATION TO THE BOUNDARY. DIFFERENCES REMAIN HOWEVER WITH RESPECT TO EVENTUAL LOCATION OF THE BOUNDARY BUT WITH A GENERAL CONSENSUS NOW PLACING IT JUST SOUTH OF THE REGION...CARRYING PRECIP CHANCES REMAINS WARRANTED INTO THE FIRST HALF OF THE WEEKEND. WILL PLACE HIGHEST POPS FRIDAY INTO EARLY SATURDAY OVER SOUTHERN COUNTIES AS A SURFACE WAVE RIDES ALONG THE BOUNDARY. WITH A DEEP MOIST AIRMASS IN PLACE FRIDAY/SATURDAY...HEAVY RAIN IS LIKELY TO ACCOMPANY STORMS. DRIER AIR ATTEMPTS TO MAKE A BRIEF APPEARANCE SATURDAY NIGHT WITH HIGH PRESSURE OVER THE NORTHERN GREAT LAKES...BUT THE ARRIVAL OF ADDITIONAL WAVES ALOFT AND THE REMNANT BOUNDARY LINGERING IN THE OHIO VALLEY SUPPORTS REINTRODUCING POPS INTO EARLY NEXT WEEK. TEMPERATURES WILL REMAIN SEASONABLE BUT CONTINUE TO RUN SLIGHTLY BELOW NORMAL THROUGH THE EXTENDED...WITH HIGHS RANGING FROM THE UPPER 70S TO MIDDLE 80S. && .AVIATION /DISCUSSION FOR 051200Z TAF ISSUANCE/... ISSUED AT 628 AM EDT TUE AUG 5 2014 MVFR CONDITIONS POSSIBLE LATE TONIGHT...OTHERWISE VFR EXPECTED. WEAKENING AREA OF SHOWERS PROGRESSING INTO THE REGION THIS MORNING MAY BRIEFLY IMPACT ALL BUT KLAF. SHORT RANGE MODEL GUIDANCE CONTINUES TO WEAKEN AND DIMINISH THE PRECIP AREA BY LATE MORNING. EXPECT VFR CU DEVELOPMENT THIS AFTERNOON ALONG WITH SCATTERED CONVECTION AS A WEAK FRONTAL BOUNDARY DROPS INTO CENTRAL INDIANA. WILL CARRY VCTS AT KLAF THROUGH THE AFTERNOON WHERE FORCING ALOFT IS SOMEWHAT BETTER. CONFIDENCE IN CONVECTIVE TIMING AND COVERAGE REMAINS HIGHLY UNCERTAIN AT THE OTHER TERMINALS AND WILL KEEP THESE SITES DRY AT THIS TIME. SOUTHWEST WINDS AT 5 TO 10KTS EXPECTED THIS AFTERNOON. WINDS WILL BECOME LIGHT TONIGHT AS THEY VEER TO N/NW BEHIND THE BOUNDARY. MODEL SOUNDINGS INDICATING MID LEVEL CLOUDS LIKELY TO BECOME THE PREDOMINANT DECK AS THE NIGHT PROGRESSES WITH SLIGHTLY DRIER AIR WITHIN THE BOUNDARY LAYER NORTH OF THE BOUNDARY. COULD SEE MVFR FOG DEVELOP AT OUTLYING TERMINALS LATE. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...CP NEAR TERM...CP/50 SHORT TERM...CP LONG TERM....RYAN AVIATION...RYAN VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSINDIANAPOLIS WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
628 AM EDT TUE AUG 5 2014 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 359 AM EDT TUE AUG 5 2014 A COLD FRONT MOVING INTO THE AREA WILL BRING CHANCES FOR THUNDERSTORMS TO CENTRAL INDIANA TODAY. THIS FRONT WILL STALL SOMEWHERE IN THE AREA AND UPPER WAVES WILL INTERACT WITH IT THROUGH THE REST OF THE WEEK KEEPING THUNDERSTORM CHANCES IN THE FORECAST. NEAR NORMAL TEMPERATURES WILL TAKE A SMALL DIP IN THE WAKE OF THE COLD FRONTAL PASSAGE WEDNESDAY AND THURSDAY BEFORE REBOUNDING TO NORMAL FROM THURSDAY ON. && .NEAR TERM /TODAY/... ISSUED AT 359 AM EDT TUE AUG 5 2014 RADAR MOSAIC SHOWS SHOWERS AND THUNDERSTORMS MOVING INTO THE NORTHWESTERN COUNTIES BUT SHRINKING AS THEY DO. THESE WILL SLOWLY MOVE IN BUT COVERAGE WILL BE LESS AND LESS BASED ON CURRENT TRENDS. THUS KEPT POPS AT CHANCE/SCATTERED OR LESS FOR THE REST OF THE EARLY MORNING. AFTER THAT SHORT TERM MODELS ARE SHOWING EVEN LESS COVERAGE BUT PERHAPS AN INCREASE AGAIN IN THE AFTERNOON. TRIED TO TIME THE POPS FOR THE TODAY PERIOD WITH THE MOVEMENT OF THE UPPER WAVE AND KEPT THE HIGHEST POPS ACROSS THE NORTH. BROUGHT A SLIGHT CHANCE IN ACROSS THE SOUTH FOR THE AFTERNOON INSTEAD OF KEEPING THINGS DRY WITH RAP SHOWING SOME DEVELOPMENT THERE AS WELL BUT THE BEST FORCING STAYING FAR FROM THERE. FOR TEMPERATURES THOUGHT THE CONSENSUS NUMBERS DID A GOOD JOB. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/... ISSUED AT 359 AM EDT TUE AUG 5 2014 FOR TONIGHT CONTINUED WITH SOME POPS AS A CARRYOVER FROM TODAY AS THE UPPER WAVE WILL BE MOVING OUT. BY LATE TONIGHT WENT DRY WITH LITTLE FORCING PRESENT. FOR WEDNESDAY MODELS HAVE TRENDED DRIER THIS RUN. NOT READY TO BUY THIS FULL ON SINCE LAST NIGHT/S RUNS HAD WEDNESDAY LOOKING FAIRLY WET. THUS BLENDED PREVIOUS AND CURRENT SOLUTIONS TO PROVIDE A COMPROMISE OF LOW CHANCE POPS ACROSS THE AREA. THE BEST FORCING WILL NOT BE ARRIVING UNTIL VERY LATE WEDNESDAY NIGHT INTO THURSDAY WITH A SHORTWAVE PROVIDING ADDITIONAL FORCING TO THE FRONT WHOSE EXACT POSITION IS STILL VARIABLE BETWEEN MODELS AND RUN-TO-RUN. WENT WITH THE HIGHEST POPS IN THE PERIOD ON THURSDAY WITH THE FORCING FROM THE UPPER WAVE. IF THE SURFACE FRONT SETS UP JUST TO THE SOUTH OR RIGHT ACROSS THE AREA HEAVY RAIN COULD BE A PROBLEM...BUT AT THIS POINT THE EXACT LOCATION OF THAT FRONT IS STILL VERY LOW CONFIDENCE. FOR TEMPERATURES THROUGH THE PERIOD GENERALLY USED A CONSENSUS. FOR THURSDAY/S HIGHS THOUGH WENT LOWER THAN THE MODEL AVERAGE TO REFLECT THE POTENTIAL FOR COOLER TEMPERATURES WITH THE HIGHER PROBABILITY FOR CLOUD COVER AND RAIN. && .LONG TERM /FRIDAY THROUGH MONDAY/... ISSUED AT 359 AM EDT TUE AUG 5 2014 THE THREAT FOR UNSETTLED WEATHER IS LIKELY TO PERSIST INTO THE WEEKEND AS NORTHWEST FLOW ALOFT REMAINS ACROSS THE REGION AND A FRONTAL BOUNDARY ALIGNS OVER THE TENNESSEE AND LOWER OHIO VALLEYS. 00Z MODEL SUITE HAS SHIFTED THE FRONT FURTHER NORTH FROM PREVIOUS RUNS...ESPECIALLY THE ECMWF AND OP GFS WHICH BOTH HAD MAINTAINED A MORE SUPPRESSED LOCATION TO THE BOUNDARY. DIFFERENCES REMAIN HOWEVER WITH RESPECT TO EVENTUAL LOCATION OF THE BOUNDARY BUT WITH A GENERAL CONSENSUS NOW PLACING IT JUST SOUTH OF THE REGION...CARRYING PRECIP CHANCES REMAINS WARRANTED INTO THE FIRST HALF OF THE WEEKEND. WILL PLACE HIGHEST POPS FRIDAY INTO EARLY SATURDAY OVER SOUTHERN COUNTIES AS A SURFACE WAVE RIDES ALONG THE BOUNDARY. WITH A DEEP MOIST AIRMASS IN PLACE FRIDAY/SATURDAY...HEAVY RAIN IS LIKELY TO ACCOMPANY STORMS. DRIER AIR ATTEMPTS TO MAKE A BRIEF APPEARANCE SATURDAY NIGHT WITH HIGH PRESSURE OVER THE NORTHERN GREAT LAKES...BUT THE ARRIVAL OF ADDITIONAL WAVES ALOFT AND THE REMNANT BOUNDARY LINGERING IN THE OHIO VALLEY SUPPORTS REINTRODUCING POPS INTO EARLY NEXT WEEK. TEMPERATURES WILL REMAIN SEASONABLE BUT CONTINUE TO RUN SLIGHTLY BELOW NORMAL THROUGH THE EXTENDED...WITH HIGHS RANGING FROM THE UPPER 70S TO MIDDLE 80S. && .AVIATION /DISCUSSION FOR 051200Z TAF ISSUANCE/... ISSUED AT 628 AM EDT TUE AUG 5 2014 MVFR CONDITIONS POSSIBLE LATE TONIGHT...OTHERWISE VFR EXPECTED. WEAKENING AREA OF SHOWERS PROGRESSING INTO THE REGION THIS MORNING MAY BRIEFLY IMPACT ALL BUT KLAF. SHORT RANGE MODEL GUIDANCE CONTINUES TO WEAKEN AND DIMINISH THE PRECIP AREA BY LATE MORNING. EXPECT VFR CU DEVELOPMENT THIS AFTERNOON ALONG WITH SCATTERED CONVECTION AS A WEAK FRONTAL BOUNDARY DROPS INTO CENTRAL INDIANA. WILL CARRY VCTS AT KLAF THROUGH THE AFTERNOON WHERE FORCING ALOFT IS SOMEWHAT BETTER. CONFIDENCE IN CONVECTIVE TIMING AND COVERAGE REMAINS HIGHLY UNCERTAIN AT THE OTHER TERMINALS AND WILL KEEP THESE SITES DRY AT THIS TIME. SOUTHWEST WINDS AT 5 TO 10KTS EXPECTED THIS AFTERNOON. WINDS WILL BECOME LIGHT TONIGHT AS THEY VEER TO N/NW BEHIND THE BOUNDARY. MODEL SOUNDINGS INDICATING MID LEVEL CLOUDS LIKELY TO BECOME THE PREDOMINANT DECK AS THE NIGHT PROGRESSES WITH SLIGHTLY DRIER AIR WITHIN THE BOUNDARY LAYER NORTH OF THE BOUNDARY. COULD SEE MVFR FOG DEVELOP AT OUTLYING TERMINALS LATE. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...CP NEAR TERM...CP SHORT TERM...CP LONG TERM....RYAN AVIATION...RYAN VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSINDIANAPOLIS WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1024 AM EDT TUE AUG 5 2014 .SYNOPSIS... ISSUED AT 357 AM EDT TUE AUG 5 2014 ISOLATED SHOWERS AND THUNDERSTORMS ARE AGAIN POSSIBLE IN INTERIOR AREAS OF NORTHERN LOWER MICHIGAN THIS AFTERNOON AND EVENING. HIGH PRESSURE WILL THEN SETTLE IN OVER THE GREAT LAKES REGION WEDNESDAY. THIS HIGH PRESSURE WILL REMAIN IN CONTROL OF THE WEATHER THROUGH THE UPCOMING WEEKEND. TEMPERATURES WILL BE IN THE 70S TO LOWER 80S EACH DAY WITH LOWS GENERALLY IN THE 50S. && .UPDATE... ISSUED AT 1024 AM EDT TUE AUG 5 2014 A NICE EARLY AUGUST DAY UNFOLDING ACROSS THE AREA...WITH THE PASSAGE OF A SHORTWAVE TROUGH BRINGING AN END TO LINGERING SHOWERS DOWN TOWARD THE M-55 CORRIDOR. SOME PESKY LINGERING MID LEVEL MOISTURE WILL LIKELY MILL AROUND DOWN THAT WAY FOR A FEW MORE HOURS WITH BOUTS OF THICKER CLOUD COVER...WHILE AREAS FARTHER NORTH CONTINUE TO SEE LOW/MID LEVEL DRYING WITH THE PASSAGE OF SAID WAVE. THAT SHOULD RESULT IN A GOOD DEAL OF SUNSHINE THROUGH EARLY AFTERNOON...THOUGH WITH THE TYPICAL SUMMERTIME BLOSSOMING OF SOME CUMULUS BENEATH WEAKISH THERMAL TROUGHING STILL IN PLACE. NOT AT ALL CONVINCED WE WILL REALIZE ANY ADDITIONAL SHOWERS LATER THIS AFTERNOON...AS THE BOUNDARY LAYER ALREADY LOOKS A SHADE DRIER THAN YESTERDAY PER 12Z APX RAOB...INDICATIVE OF DEW POINTS LIKELY MIXING OUT BACK THROUGH THE LOWER 50S WHILE AFTERNOON HIGHS REMAIN QUITE SIMILAR TO THOSE OF 24 HOURS AGO. GIVEN LITTLE THERMAL ADVECTION ALOFT THROUGH THE DAY...IT WILL TAKE BETTER MOISTURE POOLING TO JUST SQUEEZE BY THE CAP UP AROUND 600 MB. IF THAT`S GOING TO HAPPEN ANYWHERE IT WILL BE ACROSS THE SOUTHEAST CWA WHERE BETTER LAKE BREEZE CONVERGENCE SHOULD RESIDE OFF LAKE HURON/SAGINAW BAY...BUT EVEN THERE THE CHANCE IS QUITE LOW. HAVE LOWERED POPS INTO THE `ISOLATED` RANGE WHILE ALSO RAISING HIGHS A COUPLE DEGREES FOR MANY AREAS BASED OFF YESTERDAY`S READINGS AND LITTLE CHANGE IN AIRMASS...NOT TO MENTION CURRENT OBS ALREADY WITHIN 5-7 DEGREES OF GOING HIGHS. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 357 AM EDT TUE AUG 5 2014 ...ONE MORE CHANCE FOR SHOWERS AND STORMS... IMPACTS: LIGHTNING THIS AFTERNOON...MAINLY SOUTH OF M-72. CURRENT WEATHER AND SYNOPTIC PATTERN: NO SURPRISE TO THE UPPER LEVEL PATTERN WITH TROUGHING ACROSS THE EASTERN COUNTRY INCLUDING THE GREAT LAKES...AND RIDGING OVER THE WEST. SFC HIGH PRESSURE AND DRIEST AIR WAS DRAPED FROM THE DAKOTAS THROUGH SRN ONTARIO...NOSING INTO EASTERN UPPER. A FRONTAL BOUNDARY WAS NOTED FROM THE EASTERN GREAT LAKES THROUGH SRN LOWER AND INTO WISCONSIN. THERE WAS AN AXIS OF INCREASED H8 MOISTURE AND ELEVATED FRONT STILL HOLDING ACROSS AREAS SOUTH OF M-32...WITH AN INCOMING SHORTWAVE IN NW FLOW ALOFT. THIS HAS RESULTED IN A BAND OF SHOWERS THERE...BUT NO THUNDER THUS FAR. THERE IS JUST A LACK OF INSTABILITY (WHICH REMAINS NEARER THE SFC FRONT IN SRN LOWER). SYNOPTIC PATTERN/WEATHER EVOLUTION: STILL FACING THE SAME PROBLEM WITH THE TODAY/TONIGHT FORECAST. THIS REVOLVES AROUND WHETHER OR NOT WE WILL SEE ANY AFTERNOON AND EVENING SHOWER AND THUNDERSTORM DEVELOPMENT. YESTERDAYS NON-ACTION WAS A LITTLE SURPRISING BUT RESULTED IN A QUICK LOOK BACK AT DATA. THE 00Z APX SOUNDING SHOWED MUCH DRIER AIR BELOW 750MB THAN WHAT WAS SUGGESTED IN YESTERDAYS DATA. MODELS HAVE OVER-FORECASTED BL MOISTURE OVER THE LAST FEW DAYS. LATEST RUC SHOWING A WEDGE OF DRIER H8 AIR SWEEPING DOWN INTO US BEHIND THE SHORTWAVE AND SHOWERS WHICH WILL DEPART BY MID MORNING. THIS WILL BRING A PERIOD OF QUIET NO PRECIP WEATHER. HEATING THROUGH THE DAY WILL ALLOW TEMPS TO MAX OUT HIGHER THAN GUIDANCE (ALSO RUNNING TOO COOL) IN THE MID AND UPPER 70S. FCST BFR SOUNDINGS SHOW INCORRECT INCREASED MOISTURE DEVELOPING AROUND H8 (A FUNCTION OF CONVECTION TAKING OFF IN THE MODELS)...WHAT IS MORE LIKELY IS FOR VERY SHALLOW RIDGING THIS AFTERNOON BEHIND THE WAVE...WITH VERY LITTLE IN THE WAY OF ADVECTION DUE TO CONTINUED LIGHT WINDS. AM EXPECTING THE BL TO MIX OUT DECENTLY AGAIN (BUT CURRENT RAINS WILL ADD TO LOW LEVEL MOISTURE AVAILABILITY). FCST SOUNDINGS SHOW CONTINUED COOLING ALOFT (WHICH SEEMS ODD CONSIDERING THE SHALLOW RIDGING)...AND SFC BASED DEW POINTS (OUTSIDE OF WHERE CURRENT RAIN SHOWERS RESIDE) ARE A COUPLE/FEW DEGREES TOO HIGH. REGARDLESS...EVEN TAKING A FAIRLY DRY PARCEL...MODIFICATION RESULTS IN SNEAKING BY A WEAK CAP ALOFT AROUND 600MB. 400-800 J/KG ARE SEEN IN INTERIOR NRN LOWER (WHERE LAKE BREEZE CONVERGENCE WILL MAXIMIZE). CAN SEE ISOLATED TO SCATTERED SHOWERS AND A FEW STORMS FIRING OFF...WITH NOTHING IN THE LAKE BREEZE CONVERGENCE IN MACKINAC COUNTY DUE TO TOO DRY OF AIR. THESE SHOWERS WILL LIKELY FADE OFF THROUGH EVENING...BUT WILL HAVE TO WATCH NEXT INCOMING SHORTWAVE FROM ONTARIO LATER TONIGHT. THERE MAY BE AN OUTSIDE CHANCE THAT A FEW OF THESE SHOWERS MAY BE ABLE TO CONTINUE INTO THE NIGHT...BUT CONFIDENCE IN THAT IS RATHER LOW. WILL END ALL SHOWERS BY MID/LATE EVENING. && .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 357 AM EDT TUE AUG 5 2014 ...QUIET THROUGH THE WEEKEND... OVERVIEW...THE BASICS OF THE PATTERN ARE GOING TO MOVE WITH THEM ONLY REESTABLISHING THEMSELVES BY NEXT WEEK. SO THE MAIN IDEA WILL BE THAT THE RIDGE IN THE WEST WILL MIGRATE EAST INTO THE UPPER GREAT LAKES. THIS WILL PRODUCE MAINLY DRY WEATHER THROUGH THE WEEKEND. THEN THE CHANCE OF SHOWERS AND THUNDERSTORMS MONDAY. SO WITH THAT IN MIND THE FORECAST LOOKS LIKE THIS... (8/6)WEDNESDAY AND (8/7)THURSDAY...THE SFC HIGH BUILDS OVER THE REGION WEDNESDAY AS A 500 MB SHORTWAVE TROUGH MOVES THROUGH THE REGION WITH FAIRLY DRY AIR (700-500 MB LAYER RH <30% AND 850 MB RH <50%). THIS LEAVES THE REGION RAIN FREE. THE SAME CONDITIONS ARE EXPECTED TO REMAIN OVER THE UPPER GREAT LAKES AS THE RIDGING TAKES PLACE THROUGH THE LOWER AND MID LEVELS. EXTENDED (FRIDAY THROUGH MONDAY)...THE RIDGING IS EXPECTED TO REMAIN FRIDAY AND SATURDAY AS WELL, AT LEAST ON THE ECMWF. THE GFS TRIES TO RAM RAIN NORTH INTO THE SW COUNTIES LATE ON SATURDAY AS SOME SHORTWAVE DIGS INTO THE 500 MB RIDGE. HOWEVER, THINK THAT THE ECMWF IS THE BETTER OF THE TWO MODELS AS THE 500MB RIDGING SHOULD REMAIN STRONG ENOUGH TO SHUNT THE SHORTWAVE NORTH. IT NOT UNTIL (8/10)SUNDAY THAT WE BEGIN TO GET A CHANGE FOR SOMETHING ORGANIZED. WHILE THE DAY AND NIGHT STILL REMAIN DRY, A 500 MB TROUGH AND SFC COLD FRONT BEGINS TO MARCH INTO THE UPPER GREAT LAKES, LATE ON SUNDAY NIGHT. THE MODELS ARE BEGINNING TO PUSH THE FRONT THROUGH ON MONDAY OR MONDAY NIGHT. THE ECMWF IS THE FASTER OF THE TWO MODELS, IN THIS CASE. SO WILL CONTINUE THE MONDAY POPS AND CONTINUE THEM INTO MONDAY NIGHT AS THE BOTH THE ECWMF AND THE GFS HAVE THE FRONT OVER THE FORECAST AREA OVERNIGHT. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 653 AM EDT TUE AUG 5 2014 ...VFR... SCATTERED RAIN SHOWERS ARE EXITING AWAY FROM TVC/MBL ATTM WITH CLEARING SKIES QUICKLY SETTLING IN. ONLY A FEW CUMULUS AROUND THE AIRPORTS WITH LAKE BREEZES YET AGAIN. LIGHT/CALM WINDS TONIGHT WITH MAYBE SOME HIGHER LEVEL CLOUD FOR MAINLY PLN/APN. && .MARINE... ISSUED AT 357 AM EDT TUE AUG 5 2014 NO WIND AND WAVE ISSUES TO BE CONCERNED WITH FOR SEVERAL DAYS...LIKELY THROUGH THE UPCOMING WEEKEND. HIGH PRESSURE TAKES CONTROL OF THE WEATHER WEDNESDAY ONWARD...WITH DRY AIR AND AFTERNOON LAKE BREEZES. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...NONE. LM...NONE. LS...NONE. && $$ UPDATE...LAWRENCE SYNOPSIS...JL SHORT TERM...SMD LONG TERM...JL AVIATION...SMD MARINE...SMD
AREA FORECAST DISCUSSION
NWS GAYLORD MI
655 AM EDT TUE AUG 5 2014 .SYNOPSIS... ISSUED AT 357 AM EDT TUE AUG 5 2014 ISOLATED SHOWERS AND THUNDERSTORMS ARE AGAIN POSSIBLE IN INTERIOR AREAS OF NORTHERN LOWER MICHIGAN THIS AFTERNOON AND EVENING. HIGH PRESSURE WILL THEN SETTLE IN OVER THE GREAT LAKES REGION WEDNESDAY. THIS HIGH PRESSURE WILL REMAIN IN CONTROL OF THE WEATHER THROUGH THE UPCOMING WEEKEND. TEMPERATURES WILL BE IN THE 70S TO LOWER 80S EACH DAY WITH LOWS GENERALLY IN THE 50S. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 357 AM EDT TUE AUG 5 2014 ...ONE MORE CHANCE FOR SHOWERS AND STORMS... IMPACTS: LIGHTNING THIS AFTERNOON...MAINLY SOUTH OF M-72. CURRENT WEATHER AND SYNOPTIC PATTERN: NO SURPRISE TO THE UPPER LEVEL PATTERN WITH TROUGHING ACROSS THE EASTERN COUNTRY INCLUDING THE GREAT LAKES...AND RIDGING OVER THE WEST. SFC HIGH PRESSURE AND DRIEST AIR WAS DRAPED FROM THE DAKOTAS THROUGH SRN ONTARIO...NOSING INTO EASTERN UPPER. A FRONTAL BOUNDARY WAS NOTED FROM THE EASTERN GREAT LAKES THROUGH SRN LOWER AND INTO WISCONSIN. THERE WAS AN AXIS OF INCREASED H8 MOISTURE AND ELEVATED FRONT STILL HOLDING ACROSS AREAS SOUTH OF M-32...WITH AN INCOMING SHORTWAVE IN NW FLOW ALOFT. THIS HAS RESULTED IN A BAND OF SHOWERS THERE...BUT NO THUNDER THUS FAR. THERE IS JUST A LACK OF INSTABILITY (WHICH REMAINS NEARER THE SFC FRONT IN SRN LOWER). SYNOPTIC PATTERN/WEATHER EVOLUTION: STILL FACING THE SAME PROBLEM WITH THE TODAY/TONIGHT FORECAST. THIS REVOLVES AROUND WHETHER OR NOT WE WILL SEE ANY AFTERNOON AND EVENING SHOWER AND THUNDERSTORM DEVELOPMENT. YESTERDAYS NON-ACTION WAS A LITTLE SURPRISING BUT RESULTED IN A QUICK LOOK BACK AT DATA. THE 00Z APX SOUNDING SHOWED MUCH DRIER AIR BELOW 750MB THAN WHAT WAS SUGGESTED IN YESTERDAYS DATA. MODELS HAVE OVER-FORECASTED BL MOISTURE OVER THE LAST FEW DAYS. LATEST RUC SHOWING A WEDGE OF DRIER H8 AIR SWEEPING DOWN INTO US BEHIND THE SHORTWAVE AND SHOWERS WHICH WILL DEPART BY MID MORNING. THIS WILL BRING A PERIOD OF QUIET NO PRECIP WEATHER. HEATING THROUGH THE DAY WILL ALLOW TEMPS TO MAX OUT HIGHER THAN GUIDANCE (ALSO RUNNING TOO COOL) IN THE MID AND UPPER 70S. FCST BFR SOUNDINGS SHOW INCORRECT INCREASED MOISTURE DEVELOPING AROUND H8 (A FUNCTION OF CONVECTION TAKING OFF IN THE MODELS)...WHAT IS MORE LIKELY IS FOR VERY SHALLOW RIDGING THIS AFTERNOON BEHIND THE WAVE...WITH VERY LITTLE IN THE WAY OF ADVECTION DUE TO CONTINUED LIGHT WINDS. AM EXPECTING THE BL TO MIX OUT DECENTLY AGAIN (BUT CURRENT RAINS WILL ADD TO LOW LEVEL MOISTURE AVAILABILITY). FCST SOUNDINGS SHOW CONTINUED COOLING ALOFT (WHICH SEEMS ODD CONSIDERING THE SHALLOW RIDGING)...AND SFC BASED DEW POINTS (OUTSIDE OF WHERE CURRENT RAIN SHOWERS RESIDE) ARE A COUPLE/FEW DEGREES TOO HIGH. REGARDLESS...EVEN TAKING A FAIRLY DRY PARCEL...MODIFICATION RESULTS IN SNEAKING BY A WEAK CAP ALOFT AROUND 600MB. 400-800 J/KG ARE SEEN IN INTERIOR NRN LOWER (WHERE LAKE BREEZE CONVERGENCE WILL MAXIMIZE). CAN SEE ISOLATED TO SCATTERED SHOWERS AND A FEW STORMS FIRING OFF...WITH NOTHING IN THE LAKE BREEZE CONVERGENCE IN MACKINAC COUNTY DUE TO TOO DRY OF AIR. THESE SHOWERS WILL LIKELY FADE OFF THROUGH EVENING...BUT WILL HAVE TO WATCH NEXT INCOMING SHORTWAVE FROM ONTARIO LATER TONIGHT. THERE MAY BE AN OUTSIDE CHANCE THAT A FEW OF THESE SHOWERS MAY BE ABLE TO CONTINUE INTO THE NIGHT...BUT CONFIDENCE IN THAT IS RATHER LOW. WILL END ALL SHOWERS BY MID/LATE EVENING. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 357 AM EDT TUE AUG 5 2014 ...QUIET THROUGH THE WEEKEND... OVERVIEW...THE BASICS OF THE PATTERN ARE GOING TO MOVE WITH THEM ONLY REESTABLISHING THEMSELVES BY NEXT WEEK. SO THE MAIN IDEA WILL BE THAT THE RIDGE IN THE WEST WILL MIGRATE EAST INTO THE UPPER GREAT LAKES. THIS WILL PRODUCE MAINLY DRY WEATHER THROUGH THE WEEKEND. THEN THE CHANCE OF SHOWERS AND THUNDERSTORMS MONDAY. SO WITH THAT IN MIND THE FORECAST LOOKS LIKE THIS... (8/6)WEDNESDAY AND (8/7)THURSDAY...THE SFC HIGH BUILDS OVER THE REGION WEDNESDAY AS A 500 MB SHORTWAVE TROUGH MOVES THROUGH THE REGION WITH FAIRLY DRY AIR (700-500 MB LAYER RH <30% AND 850 MB RH <50%). THIS LEAVES THE REGION RAIN FREE. THE SAME CONDITIONS ARE EXPECTED TO REMAIN OVER THE UPPER GREAT LAKES AS THE RIDGING TAKES PLACE THROUGH THE LOWER AND MID LEVELS. EXTENDED (FRIDAY THROUGH MONDAY)...THE RIDGING IS EXPECTED TO REMAIN FRIDAY AND SATURDAY AS WELL, AT LEAST ON THE ECMWF. THE GFS TRIES TO RAM RAIN NORTH INTO THE SW COUNTIES LATE ON SATURDAY AS SOME SHORTWAVE DIGS INTO THE 500 MB RIDGE. HOWEVER, THINK THAT THE ECMWF IS THE BETTER OF THE TWO MODELS AS THE 500MB RIDGING SHOULD REMAIN STRONG ENOUGH TO SHUNT THE SHORTWAVE NORTH. IT NOT UNTIL (8/10)SUNDAY THAT WE BEGIN TO GET A CHANGE FOR SOMETHING ORGANIZED. WHILE THE DAY AND NIGHT STILL REMAIN DRY, A 500 MB TROUGH AND SFC COLD FRONT BEGINS TO MARCH INTO THE UPPER GREAT LAKES, LATE ON SUNDAY NIGHT. THE MODELS ARE BEGINNING TO PUSH THE FRONT THROUGH ON MONDAY OR MONDAY NIGHT. THE ECMWF IS THE FASTER OF THE TWO MODELS, IN THIS CASE. SO WILL CONTINUE THE MONDAY POPS AND CONTINUE THEM INTO MONDAY NIGHT AS THE BOTH THE ECWMF AND THE GFS HAVE THE FRONT OVER THE FORECAST AREA OVERNIGHT. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 653 AM EDT TUE AUG 5 2014 ...VFR... SCATTERED RAIN SHOWERS ARE EXITING AWAY FROM TVC/MBL ATTM WITH CLEARING SKIES QUICKLY SETTLING IN. ONLY A FEW CUMULUS AROUND THE AIRPORTS WITH LAKE BREEZES YET AGAIN. LIGHT/CALM WINDS TONIGHT WITH MAYBE SOME HIGHER LEVEL CLOUD FOR MAINLY PLN/APN. && .MARINE... ISSUED AT 357 AM EDT TUE AUG 5 2014 NO WIND AND WAVE ISSUES TO BE CONCERNED WITH FOR SEVERAL DAYS...LIKELY THROUGH THE UPCOMING WEEKEND. HIGH PRESSURE TAKES CONTROL OF THE WEATHER WEDNESDAY ONWARD...WITH DRY AIR AND AFTERNOON LAKE BREEZES. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...NONE. LM...NONE. LS...NONE. && $$ SYNOPSIS...JL SHORT TERM...SMD LONG TERM...JL AVIATION...SMD MARINE...SMD
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1041 AM CDT TUE AUG 5 2014 .UPDATE... ISSUED AT 1041 AM CDT TUE AUG 5 2014 SURE ENOUGH A MID-LVL SHWR HAS BRIEFLY DEVELOPED AND PULSED UP NEAR NORTON KS /NRN/ BUT IT IS ALREADY FADING. HAVE INTRODUCED A 20% POP S AND W OF THE TRI-CITIES FROM NOW THRU EARLY AFTERNOON TO ACCT FOR WHAT COULD BE JUST SOME BRIEF SPRINKLES. BUT AN ISOLATED LIGHTNING STRIKE CAN`T BE RULED OUT. UPDATE ISSUED AT 1023 AM CDT TUE AUG 5 2014 BASED ON WHAT HAPPENED WITH DWPTS YESTERDAY SW OF THE TRI-CITIES AND LOOKING AT THIS MORNING`S DDC SOUNDING...DWPTS WERE LOWERED SEVERAL DEGS THIS AFTERNOON/EVENING. WE WILL UPDATE THE FIRE WX FCST WITH THE LOWER RH LEVELS. UPDATE ISSUED AT 937 AM CDT TUE AUG 5 2014 A COUPLE OF VERY SHORT-TERM UPDATES HAVE BEEN PUBLISHED TO KEEP FCST TEMP/DWPT TRENDS ON TRACK WITH REALITY. ALSO BRUSHED UP CLOUDS THRU 00Z AND POPS WERE SCALED BACK THRU 19Z. WE HAVE NOTED THE HRRR ENSEMBLE AND THE NAM/GFS TRY TO DEVELOP A SHWR OR TSTM THIS MORNING IN THE MCK REGION AND POSSIBLY NORTHEASTWARD. THE FIRST FEW VIS SAT PICS DO SHOW SOME CU AND/OR ACCAS. WE WILL CONT TO MONITOR THIS AND MAY NEED TO AMEND THE FCST AS IT IS CURRENTLY DRY S AND W OF THE TRI-CITIES. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 325 AM CDT TUE AUG 5 2014 REGIONAL RADAR SHOWS SOME THUNDERSTORMS ACROSS SOUTHERN SOUTH DAKOTA AND NORTHERN NEBRASKA. THESE HAVE BEEN MOVING EAST OR SOUTHEAST. SURFACE OBSERVATIONS SHOW THAT SOME LIGHT FOG HAS FORMED IN SPOTS BUT SO FAR THE VISIBILITIES HAVE ONLY BEEN 3 TO 5 MILES. THE FIRST CONCERNS WILL BE WHETHER THE THUNDERSTORMS TO THE NORTH WILL GET INTO THE AREA THIS MORNING AND IF THE FOG WILL HAVE AN IMPACT ON VISIBILITY BY MORNING. WITH THE CURRENT MOVEMENT EXPECT THAT THE MAJORITY OF THE THUNDERSTORMS WILL REMAIN NORTH OF THE AREA BUT HAVE KEPT SOME LOW POPS IN THE FAR NORTH OR NORTHEAST. SO FAR THE VISIBILITY HAS BEEN ABOVE 3 MILES. WINDS ARE A LITTLE STRONGER THAN THEY WERE LAST NIGHT. THE LATEST HRRR CONTINUES TO SHOW LOWER VISIBILITY IN THE FAR NORTHEAST. WILL KEEP SOME PATCHY FOG IN FOR EARLY THIS MORNING. AN UPPER LEVEL WAVE APPROACHES THE AREA THIS AFTERNOON. A SURFACE LOW DEVELOPING ON THE HIGH PLAINS WILL MOVE INTO THE AREA DURING THE DAY. AS THE UPPER LEVEL WAVE MOVES INTO THE AREA...THUNDERSTORMS ARE EXPECTED TO FORM NEAR THE SURFACE LOW AND A SURFACE BOUNDARY EXTENDING TO THE EAST AHEAD OF THE SURFACE LOW. EXPECT A FEW OF THE STORMS COULD BE STRONG THIS AFTERNOON AND EVENING WITH GUSTY WINDS AND SOME SMALL HAIL. THE THUNDERSTORMS ARE EXPECTED TO CONTINUE ACROSS THE AREA TONIGHT AS THE UPPER WAVE MOVES THROUGH THE AREA AND THE SURFACE LOW MOVES INTO THE FORECAST AREA. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 325 AM CDT TUE AUG 5 2014 THE WEATHER PATTERN BECOMES MORE UNSETTLED DURING THE EXTENDED PERIODS. BEGINNING ON WEDNESDAY...CONVECTION MAY BE ONGOING FOR THE FIRST PART OF THE DAY AHEAD OF AN ADVANCING COLD FRONTAL BOUNDARY AS AN UPPER LOW PRESSURES SYSTEM TRANSLATES SOUTHEAST FROM THE DAKOTAS. ALSO A 40KT LOWLEVEL JET ORIENTED TOWARDS THE MO RIVER MAY SUSTAIN THE CONVECTION FOR SEVERAL HOURS IN THE MORNING. THIS INITIAL ROUND OF CONVECTION SHOULD DIMINISH WEDNESDAY MORNING WITH REDEVELOPMENT POSSIBLE DURING THE DAY ALONG THE ADVANCING COLD FRONT AND AS THE UPPER WAVE CONTINUES TO TRANSLATE SOUTHEASTWARD. A STRONG TO SEVERE STORM IS POSSIBLE WITH SREF INSTABILITY PROGS AROUND 2500 J/KG AND SHEAR NEAR 30KTS WHICH COULD LEAD TO A FEW STORMS CAPABLE OF PRODUCING LARGE HAIL/DAMAGING WINDS. PRECIPITABLE WATER VALUES ARE ON THE ORDER OF AN INCH AND A HALF AND IF STORMS CAN GO...DECENT RAINFALL AMOUNTS ARE POSSIBLE. THERE ARE SOME MODEL DIFFERENCES ON HOW QUICKLY THE BOUNDARY WILL MOVE THROUGH WEDNESDAY NIGHT WITH THE NAM FASTER THAN THE GFS WITH THE PROGRESSION. AS THE BOUNDARY MOVES THROUGH...PCPN CHANCES DECREASE N/S WITH COOLER AND DRIER AIR ADVECTING IN AS THE SURFACE RIDGE BUILDS SOUTH BEHIND THE BOUNDARY. THE MODEL DIFFERENCES CARRY INTO THURSDAY WITH THERMAL PROGS/TEMP PROFILES ON THE MODELS WITH THE NAM A FEW DEGREES COOLER WITH MID LEVEL TEMPS THAN THE GFS WHILE THE ECMWF IS IN BETWEEN THE TWO. HAVE WENT WITH MORE OF A MODEL BLEND FOR FORECAST HIGHS WITH THE THERMAL GRADIENT ORIENTED NE/SW. AFTER A MAINLY DRY DAY ON THURSDAY...CONVECTION IS EXPECTED TO REDEVELOP THURSDAY NIGHT TO OUR WEST ALONG THE HIGH PLAINS REGION IN UPSLOPE FLOW. THE GFS IS MORE ROBUST WITH THE CONVECTION WORKING EAST SOUTHEASTWARD THURSDAY NIGHT/EARLY FRIDAY THAN OTHER MODELS. DURING THIS TIME FRAME...THE GFS IS ALSO FARTHER NORTH WITH THE WARM FRONTAL BOUNDARY ACROSS KS WHEREAS NAM SUGGESTS THE BOUNDARY WILL BE IN OKLAHOMA. GIVEN THE UNCERTAINTY HAVE WENT WITH INCREASING CLOUD COVER AND KEPT THE BETTER PCPN CHCS IN OUR SW ZONES. FOR THE REMAINDER OF THE WORKWEEK AND INTO THE WEEKEND...THE PATTERN REMAINS UNSETTLED AS A SERIES OF WAVES CROSS THE INTERIOR CONUS AND THE UPPER RIDGE DAMPENS ACROSS THE SOUTHERN PLAINS. THE RIDGE BEGINS TO REBUILD TO THE NORTH AND WEST OVER THE ROCKIES LATE IN THE WEEKEND WITH A MORE AMPLIFIED NORTHWEST FLOW REGIME RETURNING BY DAY 7. CONVECTIVE POTENTIAL WILL BE DEPENDENT UPON TIMING OF WAVES AND FRONTAL BOUNDARY PLACEMENT WHICH WILL BE REFINED WITH TIME BUT THIS BEING SAID...THE WEATHER PATTERN DOES LOOK MORE ACTIVE DURING THE EXTENDED PERIODS WITH MORE PROMISING POTENTIAL FOR RAINFALL. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 613 AM CDT TUE AUG 5 2014 MVFR VISIBILITY HAS DEVELOPED IN THE AREA. WILL LEAVE IT AT MVFR SINCE LOWER VISIBILITY SHOULD BE TO THE EAST OF THE TERMINAL AREAS. THERE COULD BE A FEW THUNDERSTORMS AROUND THE AREA MAINLY DURING THE EVENING HOURS. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ UPDATE...HALBLAUB SHORT TERM...JCB LONG TERM...FAY AVIATION...JCB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1023 AM CDT TUE AUG 5 2014 .UPDATE... ISSUED AT 1023 AM CDT TUE AUG 5 2014 BASED ON WHAT HAPPENED WITH DWPTS YESTERDAY SW OF THE TRI-CITIES AND LOOKING AT THIS MORNING`S DDC SOUNDING...DWPTS WERE LOWERED SEVERAL DEGS THIS AFTERNOON/EVENING. WE WILL UPDATE THE FIRE WX FCST WITH THE LOWER RH LEVELS. UPDATE ISSUED AT 937 AM CDT TUE AUG 5 2014 A COUPLE OF VERY SHORT-TERM UPDATES HAVE BEEN PUBLISHED TO KEEP FCST TEMP/DWPT TRENDS ON TRACK WITH REALITY. ALSO BRUSHED UP CLOUDS THRU 00Z AND POPS WERE SCALED BACK THRU 19Z. WE HAVE NOTED THE HRRR ENSEMBLE AND THE NAM/GFS TRY TO DEVELOP A SHWR OR TSTM THIS MORNING IN THE MCK REGION AND POSSIBLY NORTHEASTWARD. THE FIRST FEW VIS SAT PICS DO SHOW SOME CU AND/OR ACCAS. WE WILL CONT TO MONITOR THIS AND MAY NEED TO AMEND THE FCST AS IT IS CURRENTLY DRY S AND W OF THE TRI-CITIES. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 325 AM CDT TUE AUG 5 2014 REGIONAL RADAR SHOWS SOME THUNDERSTORMS ACROSS SOUTHERN SOUTH DAKOTA AND NORTHERN NEBRASKA. THESE HAVE BEEN MOVING EAST OR SOUTHEAST. SURFACE OBSERVATIONS SHOW THAT SOME LIGHT FOG HAS FORMED IN SPOTS BUT SO FAR THE VISIBILITIES HAVE ONLY BEEN 3 TO 5 MILES. THE FIRST CONCERNS WILL BE WHETHER THE THUNDERSTORMS TO THE NORTH WILL GET INTO THE AREA THIS MORNING AND IF THE FOG WILL HAVE AN IMPACT ON VISIBILITY BY MORNING. WITH THE CURRENT MOVEMENT EXPECT THAT THE MAJORITY OF THE THUNDERSTORMS WILL REMAIN NORTH OF THE AREA BUT HAVE KEPT SOME LOW POPS IN THE FAR NORTH OR NORTHEAST. SO FAR THE VISIBILITY HAS BEEN ABOVE 3 MILES. WINDS ARE A LITTLE STRONGER THAN THEY WERE LAST NIGHT. THE LATEST HRRR CONTINUES TO SHOW LOWER VISIBILITY IN THE FAR NORTHEAST. WILL KEEP SOME PATCHY FOG IN FOR EARLY THIS MORNING. AN UPPER LEVEL WAVE APPROACHES THE AREA THIS AFTERNOON. A SURFACE LOW DEVELOPING ON THE HIGH PLAINS WILL MOVE INTO THE AREA DURING THE DAY. AS THE UPPER LEVEL WAVE MOVES INTO THE AREA...THUNDERSTORMS ARE EXPECTED TO FORM NEAR THE SURFACE LOW AND A SURFACE BOUNDARY EXTENDING TO THE EAST AHEAD OF THE SURFACE LOW. EXPECT A FEW OF THE STORMS COULD BE STRONG THIS AFTERNOON AND EVENING WITH GUSTY WINDS AND SOME SMALL HAIL. THE THUNDERSTORMS ARE EXPECTED TO CONTINUE ACROSS THE AREA TONIGHT AS THE UPPER WAVE MOVES THROUGH THE AREA AND THE SURFACE LOW MOVES INTO THE FORECAST AREA. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 325 AM CDT TUE AUG 5 2014 THE WEATHER PATTERN BECOMES MORE UNSETTLED DURING THE EXTENDED PERIODS. BEGINNING ON WEDNESDAY...CONVECTION MAY BE ONGOING FOR THE FIRST PART OF THE DAY AHEAD OF AN ADVANCING COLD FRONTAL BOUNDARY AS AN UPPER LOW PRESSURES SYSTEM TRANSLATES SOUTHEAST FROM THE DAKOTAS. ALSO A 40KT LOWLEVEL JET ORIENTED TOWARDS THE MO RIVER MAY SUSTAIN THE CONVECTION FOR SEVERAL HOURS IN THE MORNING. THIS INITIAL ROUND OF CONVECTION SHOULD DIMINISH WEDNESDAY MORNING WITH REDEVELOPMENT POSSIBLE DURING THE DAY ALONG THE ADVANCING COLD FRONT AND AS THE UPPER WAVE CONTINUES TO TRANSLATE SOUTHEASTWARD. A STRONG TO SEVERE STORM IS POSSIBLE WITH SREF INSTABILITY PROGS AROUND 2500 J/KG AND SHEAR NEAR 30KTS WHICH COULD LEAD TO A FEW STORMS CAPABLE OF PRODUCING LARGE HAIL/DAMAGING WINDS. PRECIPITABLE WATER VALUES ARE ON THE ORDER OF AN INCH AND A HALF AND IF STORMS CAN GO...DECENT RAINFALL AMOUNTS ARE POSSIBLE. THERE ARE SOME MODEL DIFFERENCES ON HOW QUICKLY THE BOUNDARY WILL MOVE THROUGH WEDNESDAY NIGHT WITH THE NAM FASTER THAN THE GFS WITH THE PROGRESSION. AS THE BOUNDARY MOVES THROUGH...PCPN CHANCES DECREASE N/S WITH COOLER AND DRIER AIR ADVECTING IN AS THE SURFACE RIDGE BUILDS SOUTH BEHIND THE BOUNDARY. THE MODEL DIFFERENCES CARRY INTO THURSDAY WITH THERMAL PROGS/TEMP PROFILES ON THE MODELS WITH THE NAM A FEW DEGREES COOLER WITH MID LEVEL TEMPS THAN THE GFS WHILE THE ECMWF IS IN BETWEEN THE TWO. HAVE WENT WITH MORE OF A MODEL BLEND FOR FORECAST HIGHS WITH THE THERMAL GRADIENT ORIENTED NE/SW. AFTER A MAINLY DRY DAY ON THURSDAY...CONVECTION IS EXPECTED TO REDEVELOP THURSDAY NIGHT TO OUR WEST ALONG THE HIGH PLAINS REGION IN UPSLOPE FLOW. THE GFS IS MORE ROBUST WITH THE CONVECTION WORKING EAST SOUTHEASTWARD THURSDAY NIGHT/EARLY FRIDAY THAN OTHER MODELS. DURING THIS TIME FRAME...THE GFS IS ALSO FARTHER NORTH WITH THE WARM FRONTAL BOUNDARY ACROSS KS WHEREAS NAM SUGGESTS THE BOUNDARY WILL BE IN OKLAHOMA. GIVEN THE UNCERTAINTY HAVE WENT WITH INCREASING CLOUD COVER AND KEPT THE BETTER PCPN CHCS IN OUR SW ZONES. FOR THE REMAINDER OF THE WORKWEEK AND INTO THE WEEKEND...THE PATTERN REMAINS UNSETTLED AS A SERIES OF WAVES CROSS THE INTERIOR CONUS AND THE UPPER RIDGE DAMPENS ACROSS THE SOUTHERN PLAINS. THE RIDGE BEGINS TO REBUILD TO THE NORTH AND WEST OVER THE ROCKIES LATE IN THE WEEKEND WITH A MORE AMPLIFIED NORTHWEST FLOW REGIME RETURNING BY DAY 7. CONVECTIVE POTENTIAL WILL BE DEPENDENT UPON TIMING OF WAVES AND FRONTAL BOUNDARY PLACEMENT WHICH WILL BE REFINED WITH TIME BUT THIS BEING SAID...THE WEATHER PATTERN DOES LOOK MORE ACTIVE DURING THE EXTENDED PERIODS WITH MORE PROMISING POTENTIAL FOR RAINFALL. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 613 AM CDT TUE AUG 5 2014 MVFR VISIBILITY HAS DEVELOPED IN THE AREA. WILL LEAVE IT AT MVFR SINCE LOWER VISIBILITY SHOULD BE TO THE EAST OF THE TERMINAL AREAS. THERE COULD BE A FEW THUNDERSTORMS AROUND THE AREA MAINLY DURING THE EVENING HOURS. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ UPDATE...HALBLAUB SHORT TERM...JCB LONG TERM...FAY AVIATION...JCB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
937 AM CDT TUE AUG 5 2014 .UPDATE... ISSUED AT 937 AM CDT TUE AUG 5 2014 A COUPLE OF VERY SHORT-TERM UPDATES HAVE BEEN PUBLISHED TO KEEP FCST TEMP/DWPT TRENDS ON TRACK WITH REALITY. ALSO BRUSHED UP CLOUDS THRU 00Z AND POPS WERE SCALED BACK THRU 19Z. WE HAVE NOTED THE HRRR ENSEMBLE AND THE NAM/GFS TRY TO DEVELOP A SHWR OR TSTM THIS MORNING IN THE MCK REGION AND POSSIBLY NORTHEASTWARD. THE FIRST FEW VIS SAT PICS DO SHOW SOME CU AND/OR ACCAS. WE WILL CONT TO MONITOR THIS AND MAY NEED TO AMEND THE FCST AS IT IS CURRENTLY DRY S AND W OF THE TRI-CITIES. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 325 AM CDT TUE AUG 5 2014 REGIONAL RADAR SHOWS SOME THUNDERSTORMS ACROSS SOUTHERN SOUTH DAKOTA AND NORTHERN NEBRASKA. THESE HAVE BEEN MOVING EAST OR SOUTHEAST. SURFACE OBSERVATIONS SHOW THAT SOME LIGHT FOG HAS FORMED IN SPOTS BUT SO FAR THE VISIBILITIES HAVE ONLY BEEN 3 TO 5 MILES. THE FIRST CONCERNS WILL BE WHETHER THE THUNDERSTORMS TO THE NORTH WILL GET INTO THE AREA THIS MORNING AND IF THE FOG WILL HAVE AN IMPACT ON VISIBILITY BY MORNING. WITH THE CURRENT MOVEMENT EXPECT THAT THE MAJORITY OF THE THUNDERSTORMS WILL REMAIN NORTH OF THE AREA BUT HAVE KEPT SOME LOW POPS IN THE FAR NORTH OR NORTHEAST. SO FAR THE VISIBILITY HAS BEEN ABOVE 3 MILES. WINDS ARE A LITTLE STRONGER THAN THEY WERE LAST NIGHT. THE LATEST HRRR CONTINUES TO SHOW LOWER VISIBILITY IN THE FAR NORTHEAST. WILL KEEP SOME PATCHY FOG IN FOR EARLY THIS MORNING. AN UPPER LEVEL WAVE APPROACHES THE AREA THIS AFTERNOON. A SURFACE LOW DEVELOPING ON THE HIGH PLAINS WILL MOVE INTO THE AREA DURING THE DAY. AS THE UPPER LEVEL WAVE MOVES INTO THE AREA...THUNDERSTORMS ARE EXPECTED TO FORM NEAR THE SURFACE LOW AND A SURFACE BOUNDARY EXTENDING TO THE EAST AHEAD OF THE SURFACE LOW. EXPECT A FEW OF THE STORMS COULD BE STRONG THIS AFTERNOON AND EVENING WITH GUSTY WINDS AND SOME SMALL HAIL. THE THUNDERSTORMS ARE EXPECTED TO CONTINUE ACROSS THE AREA TONIGHT AS THE UPPER WAVE MOVES THROUGH THE AREA AND THE SURFACE LOW MOVES INTO THE FORECAST AREA. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 325 AM CDT TUE AUG 5 2014 THE WEATHER PATTERN BECOMES MORE UNSETTLED DURING THE EXTENDED PERIODS. BEGINNING ON WEDNESDAY...CONVECTION MAY BE ONGOING FOR THE FIRST PART OF THE DAY AHEAD OF AN ADVANCING COLD FRONTAL BOUNDARY AS AN UPPER LOW PRESSURES SYSTEM TRANSLATES SOUTHEAST FROM THE DAKOTAS. ALSO A 40KT LOWLEVEL JET ORIENTED TOWARDS THE MO RIVER MAY SUSTAIN THE CONVECTION FOR SEVERAL HOURS IN THE MORNING. THIS INITIAL ROUND OF CONVECTION SHOULD DIMINISH WEDNESDAY MORNING WITH REDEVELOPMENT POSSIBLE DURING THE DAY ALONG THE ADVANCING COLD FRONT AND AS THE UPPER WAVE CONTINUES TO TRANSLATE SOUTHEASTWARD. A STRONG TO SEVERE STORM IS POSSIBLE WITH SREF INSTABILITY PROGS AROUND 2500 J/KG AND SHEAR NEAR 30KTS WHICH COULD LEAD TO A FEW STORMS CAPABLE OF PRODUCING LARGE HAIL/DAMAGING WINDS. PRECIPITABLE WATER VALUES ARE ON THE ORDER OF AN INCH AND A HALF AND IF STORMS CAN GO...DECENT RAINFALL AMOUNTS ARE POSSIBLE. THERE ARE SOME MODEL DIFFERENCES ON HOW QUICKLY THE BOUNDARY WILL MOVE THROUGH WEDNESDAY NIGHT WITH THE NAM FASTER THAN THE GFS WITH THE PROGRESSION. AS THE BOUNDARY MOVES THROUGH...PCPN CHANCES DECREASE N/S WITH COOLER AND DRIER AIR ADVECTING IN AS THE SURFACE RIDGE BUILDS SOUTH BEHIND THE BOUNDARY. THE MODEL DIFFERENCES CARRY INTO THURSDAY WITH THERMAL PROGS/TEMP PROFILES ON THE MODELS WITH THE NAM A FEW DEGREES COOLER WITH MID LEVEL TEMPS THAN THE GFS WHILE THE ECMWF IS IN BETWEEN THE TWO. HAVE WENT WITH MORE OF A MODEL BLEND FOR FORECAST HIGHS WITH THE THERMAL GRADIENT ORIENTED NE/SW. AFTER A MAINLY DRY DAY ON THURSDAY...CONVECTION IS EXPECTED TO REDEVELOP THURSDAY NIGHT TO OUR WEST ALONG THE HIGH PLAINS REGION IN UPSLOPE FLOW. THE GFS IS MORE ROBUST WITH THE CONVECTION WORKING EAST SOUTHEASTWARD THURSDAY NIGHT/EARLY FRIDAY THAN OTHER MODELS. DURING THIS TIME FRAME...THE GFS IS ALSO FARTHER NORTH WITH THE WARM FRONTAL BOUNDARY ACROSS KS WHEREAS NAM SUGGESTS THE BOUNDARY WILL BE IN OKLAHOMA. GIVEN THE UNCERTAINTY HAVE WENT WITH INCREASING CLOUD COVER AND KEPT THE BETTER PCPN CHCS IN OUR SW ZONES. FOR THE REMAINDER OF THE WORKWEEK AND INTO THE WEEKEND...THE PATTERN REMAINS UNSETTLED AS A SERIES OF WAVES CROSS THE INTERIOR CONUS AND THE UPPER RIDGE DAMPENS ACROSS THE SOUTHERN PLAINS. THE RIDGE BEGINS TO REBUILD TO THE NORTH AND WEST OVER THE ROCKIES LATE IN THE WEEKEND WITH A MORE AMPLIFIED NORTHWEST FLOW REGIME RETURNING BY DAY 7. CONVECTIVE POTENTIAL WILL BE DEPENDENT UPON TIMING OF WAVES AND FRONTAL BOUNDARY PLACEMENT WHICH WILL BE REFINED WITH TIME BUT THIS BEING SAID...THE WEATHER PATTERN DOES LOOK MORE ACTIVE DURING THE EXTENDED PERIODS WITH MORE PROMISING POTENTIAL FOR RAINFALL. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 613 AM CDT TUE AUG 5 2014 MVFR VISIBILITY HAS DEVELOPED IN THE AREA. WILL LEAVE IT AT MVFR SINCE LOWER VISIBILITY SHOULD BE TO THE EAST OF THE TERMINAL AREAS. THERE COULD BE A FEW THUNDERSTORMS AROUND THE AREA MAINLY DURING THE EVENING HOURS. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ UPDATE...HALBLAUB SHORT TERM...JCB LONG TERM...FAY AVIATION...JCB
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
636 AM CDT TUE AUG 5 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 323 AM CDT TUE AUG 5 2014 TODAY AND TONIGHT...MIDLEVEL FRONTOGENESIS WOULD APPEAR TO SHIFT A BIT FARTHER SOUTH INTO NCNTL NEB TODAY ACCORDING TO THE RAP. NONE OF THE OTHER MODELS SHOW THIS BUT GIVEN THE COLD POOL WHICH FORMED IN THE WAKE OF LAST NIGHTS MCS ACROSS SRN SD...THIS WOULD APPEAR LOGICAL. THUS THE FORECAST TODAY AND TONIGHT CARRIES A HIGHER/LIKELY POP IN THE NORTHEAST ZONES WITH SCATTERED TO ISOLD COVERAGE FARTHER SOUTH WHERE THE ATMOSPHERE WILL REMAIN WARMER AND A BIT MORE CAPPED MOST OF THE DAY. H700 MB TEMPERATURES ARE COOL THROUGHOUT THE FCST AREA AT LESS THAN 14C. THE NAM INDICATES THE DISTURBANCE ACROSS SWRN COLORADO WILL MOVE ACROSS THE CNTL SANDHILLS THIS AFTN AND TONIGHT PRODUCING AN ORGANIZED AREA OF CONVECTION IN ADDITION TO THE CONVECTION WHICH WILL LIKELY CONTINUE ALONG AND NORTH OF THE MID LEVEL FRONTOGENESIS. PRECIPITABLE WATER IN THE GFS...NAM AND SREF INCREASE TO 1.5 INCHES OR HIGHER ACROSS ALL OF THE FCST AREA SUPPORTING SCATTERED OR GREATER STORM COVERAGE. THE RAP KEEPS IT AT 1.25 INCHES SOUTH OF THE STALLED FRONT ACROSS NCNTL NEB WITH THE 1.5 INCHES NORTH OF THE FRONT. THE RAP STILL DEVELOPS CONVECTION ACROSS THE SOUTH TODAY ASSOCIATED WITH A SURGE OF DRY AIR MOVING THROUGH THE PANHANDLE AND NERN COLO. A CHECK ON THE SEVERE WEATHER PARAMETERS SHOWS VERY MODEST SEVERE WEATHER POTENTIAL WITH 30 KTS OF BULK EFFECTIVE SHEAR ACROSS THE NORTHEAST AND AROUND 1500 J/KG OF CAPE. AN ISOLATED STORM WOULD SEEM POSSIBLE BUT NOT MUCH MORE IN THIS ENVIRONMENT. K INDICES RISE TO 40C OR GREATER THIS AFTERNOON AHEAD OF THE DRY SURGE AND ACROSS THE NRN ZONES. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 323 AM CDT TUE AUG 5 2014 THE FIRST IN A SERIES OF SHORTWAVES WILL CROSS THE AREA TUESDAY...WITH A COLD FRONT SETTLING SOUTH ACROSS KANSAS IN ITS WAKE ON WEDNESDAY. THE FRONT WILL REMAIN NEARLY STATIONARY THROUGH THE WEEKEND...WITH A SERIES OF SHORTWAVE DISTURBANCES TO PARADE EAST IN ZONAL FLOW ALOFT. THESE WAVES WILL INTERACT WITH A MOISTURE LATENT ATMOSPHERE TO THE NORTH OF THE FRONTAL ZONE ACROSS NEBRASKA...WITH PERIODIC CHANCES FOR SHOWERS/THUNDERSTORMS. THE FLOW ALOFT SHOULD BE STRONG ENOUGH TO PROMOTE SOME STORM ORGANIZATION...AND ONE OR TWO MESOSCALE CONVECTIVE COMPLEXES WILL BE POSSIBLE LATE WEEK INTO THE WEEKEND. PATTERN APPEARS TO SUPPORT THE POTENTIAL FOR SOME MUCH NEEDED RAINFALL ACROSS THE AREA. THE OTHER STORY WILL BE RELATIVELY COOL HIGH TEMPERATURES FOR THIS TIME OF YEAR. THIS SEEMS MOST LIKELY ACROSS NORTHERN NEBRASKA...WHERE HIGHS IN THE MID TO UPPER 70S CAN BE EXPECTED MID WEEK...WARMING TO THE LOW 80S DURING THE WEEKEND. ACROSS THE SOUTHWEST...MOSTLY MID TO UPPER 80S ARE EXPECTED EACH DAY. OVERNIGHT LOWS WILL AVERAGE NEAR NORMAL...IN THE 60S...AS HIGHER RELATIVE HUMIDITY WILL HELP KEEP THE MINIMUM TEMPERATURES MILD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 629 AM CDT TUE AUG 5 2014 IFR ACROSS NCNTL NEB THIS MORNING SHOULD GRADUALLY LIFT TO VFR 15Z-18Z. THEREAFTER SCATTERED TSTMS ARE EXPECTED TO DEVELOP 21Z ONWARD...GENERALLY FROM WEST TO EAST. THE STORM ACTIVITY COULD BECOME NUMEROUS THIS EVENING AS THE DISTURBANCE CURRENTLY ACROSS SWRN COLO LIFTS INTO THE SANDHILLS. STORM ACTIVITY IS EXPECTED TO BECOME LESS ORGANIZED FROM 06Z ONWARD AND BECOME SCATTERED OR ISOLATED BY 12Z WEDNESDAY. THE MODELS SHOW MVFR/IFR CIGS DEVELOPING FROM 04Z ONWARD ACROSS NRN NEBRASKA AND PERHAPS ACROSS THE SANDHILLS ALSO. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CDC LONG TERM...TAYLOR AVIATION...CDC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
615 AM CDT TUE AUG 5 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 325 AM CDT TUE AUG 5 2014 REGIONAL RADAR SHOWS SOME THUNDERSTORMS ACROSS SOUTHERN SOUTH DAKOTA AND NORTHERN NEBRASKA. THESE HAVE BEEN MOVING EAST OR SOUTHEAST. SURFACE OBSERVATIONS SHOW THAT SOME LIGHT FOG HAS FORMED IN SPOTS BUT SO FAR THE VISIBILITIES HAVE ONLY BEEN 3 TO 5 MILES. THE FIRST CONCERNS WILL BE WHETHER THE THUNDERSTORMS TO THE NORTH WILL GET INTO THE AREA THIS MORNING AND IF THE FOG WILL HAVE AN IMPACT ON VISIBILITY BY MORNING. WITH THE CURRENT MOVEMENT EXPECT THAT THE MAJORITY OF THE THUNDERSTORMS WILL REMAIN NORTH OF THE AREA BUT HAVE KEPT SOME LOW POPS IN THE FAR NORTH OR NORTHEAST. SO FAR THE VISIBILITY HAS BEEN ABOVE 3 MILES. WINDS ARE A LITTLE STRONGER THAN THEY WERE LAST NIGHT. THE LATEST HRRR CONTINUES TO SHOW LOWER VISIBILITY IN THE FAR NORTHEAST. WILL KEEP SOME PATCHY FOG IN FOR EARLY THIS MORNING. AN UPPER LEVEL WAVE APPROACHES THE AREA THIS AFTERNOON. A SURFACE LOW DEVELOPING ON THE HIGH PLAINS WILL MOVE INTO THE AREA DURING THE DAY. AS THE UPPER LEVEL WAVE MOVES INTO THE AREA...THUNDERSTORMS ARE EXPECTED TO FORM NEAR THE SURFACE LOW AND A SURFACE BOUNDARY EXTENDING TO THE EAST AHEAD OF THE SURFACE LOW. EXPECT A FEW OF THE STORMS COULD BE STRONG THIS AFTERNOON AND EVENING WITH GUSTY WINDS AND SOME SMALL HAIL. THE THUNDERSTORMS ARE EXPECTED TO CONTINUE ACROSS THE AREA TONIGHT AS THE UPPER WAVE MOVES THROUGH THE AREA AND THE SURFACE LOW MOVES INTO THE FORECAST AREA. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 325 AM CDT TUE AUG 5 2014 THE WEATHER PATTERN BECOMES MORE UNSETTLED DURING THE EXTENDED PERIODS. BEGINNING ON WEDNESDAY...CONVECTION MAY BE ONGOING FOR THE FIRST PART OF THE DAY AHEAD OF AN ADVANCING COLD FRONTAL BOUNDARY AS AN UPPER LOW PRESSURES SYSTEM TRANSLATES SOUTHEAST FROM THE DAKOTAS. ALSO A 40KT LOWLEVEL JET ORIENTED TOWARDS THE MO RIVER MAY SUSTAIN THE CONVECTION FOR SEVERAL HOURS IN THE MORNING. THIS INITIAL ROUND OF CONVECTION SHOULD DIMINISH WEDNESDAY MORNING WITH REDEVELOPMENT POSSIBLE DURING THE DAY ALONG THE ADVANCING COLD FRONT AND AS THE UPPER WAVE CONTINUES TO TRANSLATE SOUTHEASTWARD. A STRONG TO SEVERE STORM IS POSSIBLE WITH SREF INSTABILITY PROGS AROUND 2500 J/KG AND SHEAR NEAR 30KTS WHICH COULD LEAD TO A FEW STORMS CAPABLE OF PRODUCING LARGE HAIL/DAMAGING WINDS. PRECIPITABLE WATER VALUES ARE ON THE ORDER OF AN INCH AND A HALF AND IF STORMS CAN GO...DECENT RAINFALL AMOUNTS ARE POSSIBLE. THERE ARE SOME MODEL DIFFERENCES ON HOW QUICKLY THE BOUNDARY WILL MOVE THROUGH WEDNESDAY NIGHT WITH THE NAM FASTER THAN THE GFS WITH THE PROGRESSION. AS THE BOUNDARY MOVES THROUGH...PCPN CHANCES DECREASE N/S WITH COOLER AND DRIER AIR ADVECTING IN AS THE SURFACE RIDGE BUILDS SOUTH BEHIND THE BOUNDARY. THE MODEL DIFFERENCES CARRY INTO THURSDAY WITH THERMAL PROGS/TEMP PROFILES ON THE MODELS WITH THE NAM A FEW DEGREES COOLER WITH MID LEVEL TEMPS THAN THE GFS WHILE THE ECMWF IS IN BETWEEN THE TWO. HAVE WENT WITH MORE OF A MODEL BLEND FOR FORECAST HIGHS WITH THE THERMAL GRADIENT ORIENTED NE/SW. AFTER A MAINLY DRY DAY ON THURSDAY...CONVECTION IS EXPECTED TO REDEVELOP THURSDAY NIGHT TO OUR WEST ALONG THE HIGH PLAINS REGION IN UPSLOPE FLOW. THE GFS IS MORE ROBUST WITH THE CONVECTION WORKING EAST SOUTHEASTWARD THURSDAY NIGHT/EARLY FRIDAY THAN OTHER MODELS. DURING THIS TIME FRAME...THE GFS IS ALSO FARTHER NORTH WITH THE WARM FRONTAL BOUNDARY ACROSS KS WHEREAS NAM SUGGESTS THE BOUNDARY WILL BE IN OKLAHOMA. GIVEN THE UNCERTAINTY HAVE WENT WITH INCREASING CLOUD COVER AND KEPT THE BETTER PCPN CHCS IN OUR SW ZONES. FOR THE REMAINDER OF THE WORKWEEK AND INTO THE WEEKEND...THE PATTERN REMAINS UNSETTLED AS A SERIES OF WAVES CROSS THE INTERIOR CONUS AND THE UPPER RIDGE DAMPENS ACROSS THE SOUTHERN PLAINS. THE RIDGE BEGINS TO REBUILD TO THE NORTH AND WEST OVER THE ROCKIES LATE IN THE WEEKEND WITH A MORE AMPLIFIED NORTHWEST FLOW REGIME RETURNING BY DAY 7. CONVECTIVE POTENTIAL WILL BE DEPENDENT UPON TIMING OF WAVES AND FRONTAL BOUNDARY PLACEMENT WHICH WILL BE REFINED WITH TIME BUT THIS BEING SAID...THE WEATHER PATTERN DOES LOOK MORE ACTIVE DURING THE EXTENDED PERIODS WITH MORE PROMISING POTENTIAL FOR RAINFALL. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 613 AM CDT TUE AUG 5 2014 MVFR VISIBILITY HAS DEVELOPED IN THE AREA. WILL LEAVE IT AT MVFR SINCE LOWER VISIBILITY SHOULD BE TO THE EAST OF THE TERMINAL AREAS. THERE COULD BE A FEW THUNDERSTORMS AROUND THE AREA MAINLY DURING THE EVENING HOURS. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...JCB LONG TERM...FAY AVIATION...JCB
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1043 AM EDT TUE AUG 5 2014 .SYNOPSIS... A STALLED FRONT ALONG THE COAST WILL MOVE OFFSHORE TODAY AS TROPICAL STORM BERTHA MOVES PASSES WELL OFFSHORE OF THE CAROLINA COAST. SWELLS FROM BERTHA WILL LEAD TO AN INCREASED RIP CURRENT RISK ALONG AREA BEACHES THE NEXT SEVERAL DAYS. WARM AND MUGGY WEATHER IS EXPECTED WEDNESDAY AND THURSDAY AHEAD OF AN APPROACHING COLD FRONT. HIGH PRESSURE WILL BUILD IN FRIDAY THROUGH THE WEEKEND...LIKELY HOLDING TEMPERATURES DOWN A FEW DEGREES BELOW NORMAL. && .NEAR TERM /THROUGH TONIGHT/... AS OF 945 AM TUESDAY...LATEST RADAR TRENDS CONTINUE TO ILLUSTRATE BEST CHANCE FOR PCPN TO OCCUR ACROSS COASTAL COUNTIES. THE SMALL LOW LEVEL CIRCULATION OVER THE OFFSHORE WATERS SSE OF CAPE FEAR...WILL CONTINUE TO PULL SLOWLY NE...AWAY FROM THE MAINLAND THIS AFTERNOON AND TONIGHT...TAKING THE PCPN WITH IT. ACROSS THE INLAND COUNTIES...DRIER AIR BEGINNING TO OVERSPREAD THIS AREA VIA LATEST WATER VAPOR IMAGERY TRENDS...ALONG WITH WEAK SUBSIDENCE BECOMING MORE WIDESPREAD. A FEW POPCORN TYPE DIURNALLY DRIVEN SHRA/TSRA STILL REMAINS POSSIBLE DURING THIS AFTERNOON/EARLY EVENING. OVERALL...WILL CONTINUE WITH THE DECREASING POP TREND THRU THIS AFTN AND EVENING. MAY NEED TO RE-VISIT AND INCREASE MAX TEMPS FOR AREAS ALONG AND WEST OF THE I-95 CORRIDOR AT THE NEXT UPDATE DUE TO ADDITIONAL INSOLATION REACHING THE SFC THEN PREVIOUSLY THOUGHT. PREVIOUS DISCUSSION............................................ AS OF 645 AM TUESDAY...RADAR REVEALS A GROWING AREA OF RAIN WITH EMBEDDED CONVECTIVE ELEMENTS 30-100 MILES SOUTH AND SOUTHEAST OF CAPE FEAR...BUT A LONG RADAR LOOP REVEALS THE MAJORITY OF THE FORECAST AREA MAY BE TOO FAR WEST TO GET IN ON THIS PRECIPITATION. THE EXCEPTION IS GOING TO BE THE COASTAL CAPE FEAR REGION WHERE I HAVE NUDGED POPS UP TO AS HIGH AS 80 PERCENT IN THE SOUTHPORT-BALD HEAD ISLAND AREA. A WELL-DEFINED CIRCULATION IN RADAR IMAGERY ABOUT 60 MILES SOUTH OF OAK ISLAND APPEARS TO BE THE WESTERN ANCHOR POINT FOR THIS RAINFALL...AND DETERMINING THE PATH OF THIS FEATURE IS INSTRUMENTAL TO MAKING AN ACCURATE RAINFALL FORECAST. THE HRRR MAKES AN ATTEMPT TO INITIALIZE THE CIRCULATION AND ADVECTS IT NORTHEASTWARD...PASSING APPROXIMATELY 20 MILES EAST OF CAPE FEAR BETWEEN 16-17Z. ON THIS PATH THE BULK OF THE RAIN WILL REMAIN OVER THE OCEAN WITH THE WETTEST WEATHER EXPECTED ON LAND BETWEEN NOW AND NOON. OTHER THAN CHANGES TO SKY COVER AND POPS/PRECIP AMOUNT...THE ONLY OTHER SIGNIFICANT CHANGE WITH THE FORECAST WAS TO INCREASE THE COVERAGE OF FOG ACROSS THE INTERSTATE 95 CORRIDOR. VISIBILITIES HAVE GONE AS LOW AS 1/4 MILE IN SPOTS ALTHOUGH PREVAILING VISIBILITIES ARE HIGHER ACROSS THE REGION. A SPECIAL WEATHER STATEMENT HAS BEEN ISSUED ADDRESSING THE FOG. PREVIOUS DISCUSSION FROM 300 AM FOLLOWS... WE ARE JUST ABOUT TO GET RID OF THE DREARY WEATHER PATTERN THAT HAS BROUGHT UNSEASONABLY COOL...CLOUDY AND RAINY WEATHER TO THE COASTAL CAROLINAS FOR THE ENTIRE MONTH SO FAR. SO FAR AUGUST 2014 HAS SEEN THE 7TH COOLEST TEMPERATURES EVEN OBSERVED IN WILMINGTON WITH AN AVERAGE TEMPERATURE OF ONLY 75.7 DEGREES. HURRICANE BERTHA IS PASSING WELL EAST OF THE CAROLINAS WITH NO DIRECT IMPACTS ON OUR WEATHER TODAY. THE OLD STALLED FRONT APPEARS TO LIE ALONG THE BEACHES OF PENDER AND NEW HANOVER COUNTIES... EXTENDING SOUTHWARD FROM SOUTHPORT TO AN AREA OF LOW PRESSURE OFF THE GEORGIA COAST. THIS FEATURE SHOULD BE DRAWN EASTWARD BEHIND BERTHA TODAY...WITH DRIER AIR GRADUALLY BUILDING IN FROM THE NORTH WITH TIME. RADAR SHOWS PLENTY OF SHOWERS ACROSS THE COASTAL WATERS. THESE ARE SHALLOW CONVECTIVE FEATURES WITH ECHO TOPS GENERALLY 20KFT OR LESS...EXCEPT FOR A FEW T-STORMS FARTHER OFFSHORE WITH TOPS OVER 30KFT. SINCE THE BULK OF THIS ACTIVITY IS SHALLOW IT IS BEING STEERED BY THE 700-850 MB MEAN FLOW WHICH IS CURRENTLY FROM THE EAST. THE 00Z GFS AND 06Z RUC (OUR PREFERRED MODELS TODAY) SHOW THIS STEERING FLOW BACKING MORE NORTHERLY WITH TIME WHICH SHOULD TEND TO LIMIT HOW FAR INLAND ANY SHOWER ACTIVITY WILL MOVE. FORECAST POPS RANGE FROM 30-50 PERCENT ALONG THE COAST THIS MORNING...DIMINISHING TO 20-30 PERCENT BY NOON. FOR INTERIOR SECTIONS OF THE EASTERN CAROLINAS UNLESS AN ISOLATED SHOWER CAN DEVELOP DURING THE AFTERNOON DRY WEATHER IS EXPECTED. HIGHS SHOULD RANGE FROM THE UPPER 80S TO NEAR 90 ACROSS THE SC PEE DEE REGION TO THE MID 80S AT THE COAST. FOR TONIGHT DRY AIR SHOULD FLOOD IN THROUGHOUT THE TROPOSPHERE WITH PRECIPITABLE WATER VALUES FALLING TO LESS THAN 1.5 INCHES. SKIES SHOULD BECOME MAINLY CLEAR BY EARLY EVENING AND THERE IS LITTLE POTENTIAL FOR FOG OR LOW STRATUS OVERNIGHT. LOWS SHOULD TO NEAR 70. && .SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 AM TUESDAY...SUMMER RETURNS ON WEDNESDAY AS THE MID LEVEL FLOW GOES WESTERLY AND DOWNSLOPE ALLOWING FOR A PARTLY SUNNY AFTERNOON. PIEDMONT TROUGH DEVELOPS BUT IT ALONG WITH THE SEA BREEZE WILL GENERALLY BE TOO MOISTURE-DEPRIVED TO LEAD TO MEANINGFUL PRECIP CHANCES. AFTERNOON TEMPERATURES WILL BE NEAR OR A FEW DEGREES ABOVE CLIMO. PIEDMONT TROUGH PUSHES TOWARDS THE COAST ON THURSDAY WHILE A MID LEVEL SHORTWAVE PASSES OVERHEAD LATE IN THE AFTERNOON. NORMALLY THIS WOULD BE A GOOD SETUP FOR THUNDERSTORMS. HOWEVER THERE IS STILL VERY LITTLE MOISTURE ESPECIALLY THROUGH THE MID LEVELS. CONVECTION WILL BE LIMITED AND GENERALLY BE CONFINED TO THE COASTAL REGIONS. TEMPERATURES WILL BE QUITE SIMILAR TO THOSE OF WEDNESDAY. A COLD FRONT WILL ENTER THE REGION LATE THURSDAY NIGHT AND WILL KEEP ISOLATED SHOWERS AND THUNDERSTORMS IN THE FORECAST. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 3 AM TUESDAY...HIGH PRESSURE BUILDING IN FROM THE NORTH BEHIND THURSDAY NIGHT COLD FRONT TO END THE BRIEF SHORT TERM PERIODS SUMMER TEMPS. MOISTURE MAY POOL ALONG THE FRONT AND BRING SOME SLIGHT RAIN CHANCES OVER SWRN ZONES. THIS WILL HOLD TRUE INTO SATURDAY AS THE FRONT WASHES BACK CLOSER TO THE AREA...THE LOW RAIN CHANCES MAY INCREASE IN AREA WHILE AFTERNOON HIGHS REMAIN CAPPED BELOW CLIMO. SUNDAY IS WHEN RAIN CHANCES SHOULD RETURN AREA-WIDE AS THE FRONT LIFTS BACK INTO THE REGION. WAVE MOVES BY LATE SUNDAY INTO SUNDAY NIGHT POSSIBLY FURTHER RAMPING UP RAIN CHANCES...AND THEN LEAVING THE BOUNDARY IN OUR PRESENCE SANS WAVE ON MONDAY. CYCLONIC AND NWRLY MID LEVEL FLOW CONTINUES ON TUESDAY WITH SURFACE TROUGHINESS REDEVELOPING. RAIN CHANCES WILL LINGER INTO TUESDAY WITH CLIMO OR HIGHER CHANCES WHILE TEMPS REMAIN NEAR OR JUST SHY OF CLIMO. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... AS OF 12Z...QUITE A BIT OF LIFR CONDITIONS AROUND THE CWA...WHICH WILL LIKELY PERSIST FOR TWO OR THREE HOURS. SOME LIGHT SHOWERS NEAR THE COAST...NOT ASSOCIATED WITH TROPICAL STORM BERTHA. NOT LOOKING FOR THAT MUCH CONVECTION TODAY...MAYBE ILM. LOW PRESSURE OFF THE SOUTH CAROLINA COAST WILL FLING SOME LIGHT MOISTURE ONSHORE TO NORTH CAROLINA. THE LOW WILL PULL NORTHEAST THIS AFTERNOON...TAKING ITS MOISTURE WITH IT. SOME LOW LEVEL MOISTURE WILL REMAIN TONIGHT...HOWEVER MUCH LESS FOG/STRATUS THAN THIS MORNING. EXTENDED OUTLOOK...ISOLATED SHOWERS WED. SCATTERED SHOWERS LATE THURSDAY WITH A BETTER CHANCE FOR CONVECTION FRIDAY AND SATURDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 945 AM TUESDAY...SMALL CRAFT ADVISORY RAISED FOR THE ILM NC WATERS...DUE TO SEAS. SMALL CRAFT EXERCISE CAUTION DUE TO SEAS FOR THE ILM SC WATERS. BOTH WILL EXPIRE AT 900 PM THIS EVENING. BERTHA SWELLS NOW AFFECTING THE AREA WATERS...AND RUNNING HIGHER ACROSS THE ILM NC WATERS FROM CAPE FEAR NORTHWARD COMPARED TO THE REMAINING WATERS FROM SOUTH OF CAPE FEAR TO SOUTH SANTEE RIVER. FOR THE ILM NC WATERS...LATEST 41110 BUOY REPORTING SIGNIFICANT SEAS UP TO 5 FT...AND THE OFFSHORE BUOY 41036 REPORTING 8+ FT. BOTH BUOYS INDICATE SIG. SEAS PREDOMINATELY FROM BERTHA SWELL. PERIODS RANGE FROM 11 TO 14 SECONDS. FOR THE ILM SC WATERS...LATEST EDISTO BUOY REPORTED UP TO 7 FT SIG. SEAS...WITH WIND DRIVEN WAVES A BETTER CONTRIBUTING THEN WHATS OCCURRING ACROSS THE ILM NC WATERS. FOR WINDS...THE PROGGED SFC PRESSURE PATTERN AND GRADIENT AFTER THE DEPARTING LOW LEVEL CIRCULATION CURRENTLY MOVING FURTHER OFFSHORE FROM CAPE FEAR...WILL YIELD N TO NE WINDS AT 10-15 KT THIS AFTERNOON...BACKING TO NW TO NNW AT 10 KT DURING TONIGHT. PREVIOUS DISCUSSION.............................................. AS OF 645 AM TUESDAY...A CYCLONIC CIRCULATION IN RADAR IMAGERY LOCATED ABOUT 60 MILES SOUTH OF OAK ISLAND IS THE FEATURE TO WATCH THIS MORNING. THE LATEST HRRR MODEL SEEMS TO HAVE INITIALIZED THIS SWIRL AND MOVES IT SLOWLY NORTHEASTWARD...MISSING THE TIP OF CAPE FEAR ABOUT 20 MILES TO THE EAST BETWEEN NOON AND 1 PM EDT. LACK OF MARINE OBSERVATIONS WEST OF THE LOW IS HINDERING ANALYSIS...BUT NOAA BUOY 41004 EAST OF CHARLESTON HAS NOT GUSTED ANY HIGHER THAN 17 KNOTS IN THE PAST FEW HOURS. WAVE HEIGHTS AT THE LOCAL BUOYS HAVE CHANGED LITTLE FROM 3 AM AND NO CHANGES ARE NEEDED THERE. PREVIOUS DISCUSSION FROM 300 AM FOLLOWS... AN OLD STALLED FRONT RUNS ALONG THE BEACHES OF SE NORTH CAROLINA SOUTHWARD INTO AN AREA OF LOW PRESSURE OFF THE GEORGIA COAST. HURRICANE BERTHA IS WELL EAST OF THE CAROLINAS AND WILL MOVE NORTHEASTWARD AND FARTHER AWAY TODAY. THE GEORGIA LOW AND OUR FRONT SHOULD BE DRAWN OFFSHORE TOWARD BERTHA...LEADING TO A DRYING TREND DEVELOPING WITH TIME. UNTIL THEN...WAVES OF SHOWERS AND EMBEDDED T-STORMS ACROSS THE COASTAL WATERS SHOULD CONTINUE THROUGH THE MORNING HOURS. GENERALLY EAST OR NORTHEAST WINDS WILL TURN NORTHERLY THIS EVENING...THEN WESTERLY OVERNIGHT AS BERTHA PULLS THE LOW AND FRONT AWAY FROM THE AREA. THIS WILL LET DRIER AIR FLOOD INTO THE AREA. A SIGNIFICANT SWELL FROM BERTHA WILL IMPACT THE WATERS TODAY AND SHOULD BE THE LARGEST CONTRIBUTING FACTOR IN SEA HEIGHT FORECASTS TODAY. SEAS OF 4-5 FEET ARE EXPECTED...DIMINISHING TO 3-4 FT LATE TONIGHT. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 AM TUESDAY...PIEDMONT TROUGH ON WEDNESDAY WILL BACK INITIALLY WEST FLOW TO SOUTHWEST OR EVEN SOUTH WHILE ADDING A FEW KNOTS TO AVERAGE SPEED. SEAS MAINLY COMPRISED OF WIND WAVES IN THE 2 TO 3 FT RANGE. AS THE BOUNDARY MOVES TOWARDS THE COAST ON THURSDAY THE WIND WILL DIMINISH LATER IN THE DAY AS THE GRADIENT IS PUSHED OUT TO SEA BY THE TROUGH. THE BOUNDARY WILL SINK SOUTH ACROSS THE ZONES RATHER SLOWLY LATE THURSDAY NIGHT BRINGING A TURN TO NORTHERLY WINDS FOLLOWED BY ADDITIONAL VEERING TO EASTERLY BY THE PERIODS END...AT LEAST FOR NORTHERN ZONES. LONG TERM /FRIDAY THROUGH SATURDAY/... AS OF 3 AM TUESDAY...POST-FRONTAL ONSHORE FLOW ON FRIDAY WILL BE IN THE 10 TO 15 KT RANGE EARLY BUT SETTLE BY ABOUT 5 KT. SEAS WILL BE RUNNING JUST 2-3 FEET THEN MOST AREAS. THE HIGH WILL CONTINUE WEDGING IN FROM POINTS NORTH INTO SATURDAY WHILE THE FRONT STALLED TO THE SOUTH TRIES TO MOVE BACK TO THE NORTH SLIGHTLY. WITH RELATIVELY UNCHANGED WINDS AND NO SWELL ENERGY TO SPEAK OF SEAS WILL REMAIN 2 FEET AGAIN ON SATURDAY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...HIGH RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR SCZ054- 056. NC...HIGH RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR NCZ106- 108-110. MARINE...SMALL CRAFT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR AMZ250- 252. && $$ SYNOPSIS...MBB NEAR TERM...DCH/TRA SHORT TERM...MBB LONG TERM...MBB AVIATION...DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
653 AM EDT TUE AUG 5 2014 .SYNOPSIS... A STALLED FRONT ALONG THE COAST WILL MOVE OFFSHORE TODAY AS TROPICAL STORM BERTHA MOVES PASSES WELL OFFSHORE OF THE CAROLINA COAST. SWELLS FROM BERTHA WILL LEAD TO AN INCREASED RIP CURRENT RISK ALONG AREA BEACHES THE NEXT SEVERAL DAYS. WARM AND MUGGY WEATHER IS EXPECTED WEDNESDAY AND THURSDAY AHEAD OF AN APPROACHING COLD FRONT. HIGH PRESSURE WILL BUILD IN FRIDAY THROUGH THE WEEKEND...LIKELY HOLDING TEMPERATURES DOWN A FEW DEGREES BELOW NORMAL. && .NEAR TERM /THROUGH TONIGHT/... AS OF 645 AM TUESDAY...RADAR REVEALS A GROWING AREA OF RAIN WITH EMBEDDED CONVECTIVE ELEMENTS 30-100 MILES SOUTH AND SOUTHEAST OF CAPE FEAR...BUT A LONG RADAR LOOP REVEALS THE MAJORITY OF THE FORECAST AREA MAY BE TOO FAR WEST TO GET IN ON THIS PRECIPITATION. THE EXCEPTION IS GOING TO BE THE COASTAL CAPE FEAR REGION WHERE I HAVE NUDGED POPS UP TO AS HIGH AS 80 PERCENT IN THE SOUTHPORT-BALD HEAD ISLAND AREA. A WELL-DEFINED CIRCULATION IN RADAR IMAGERY ABOUT 60 MILES SOUTH OF OAK ISLAND APPEARS TO BE THE WESTERN ANCHOR POINT FOR THIS RAINFALL...AND DETERMINING THE PATH OF THIS FEATURE IS INSTRUMENTAL TO MAKING AN ACCURATE RAINFALL FORECAST. THE HRRR MAKES AN ATTEMPT TO INITIALIZE THE CIRCULATION AND ADVECTS IT NORTHEASTWARD...PASSING APPROXIMATELY 20 MILES EAST OF CAPE FEAR BETWEEN 16-17Z. ON THIS PATH THE BULK OF THE RAIN WILL REMAIN OVER THE OCEAN WITH THE WETTEST WEATHER EXPECTED ON LAND BETWEEN NOW AND NOON. OTHER THAN CHANGES TO SKY COVER AND POPS/PRECIP AMOUNT...THE ONLY OTHER SIGNIFICANT CHANGE WITH THE FORECAST WAS TO INCREASE THE COVERAGE OF FOG ACROSS THE INTERSTATE 95 CORRIDOR. VISIBILITIES HAVE GONE AS LOW AS 1/4 MILE IN SPOTS ALTHOUGH PREVAILING VISIBILITIES ARE HIGHER ACROSS THE REGION. A SPECIAL WEATHER STATEMENT HAS BEEN ISSUED ADDRESSING THE FOG. PREVIOUS DISCUSSION FROM 300 AM FOLLOWS... WE ARE JUST ABOUT TO GET RID OF THE DREARY WEATHER PATTERN THAT HAS BROUGHT UNSEASONABLY COOL...CLOUDY AND RAINY WEATHER TO THE COASTAL CAROLINAS FOR THE ENTIRE MONTH SO FAR. SO FAR AUGUST 2014 HAS SEEN THE 7TH COOLEST TEMPERATURES EVEN OBSERVED IN WILMINGTON WITH AN AVERAGE TEMPERATURE OF ONLY 75.7 DEGREES. HURRICANE BERTHA IS PASSING WELL EAST OF THE CAROLINAS WITH NO DIRECT IMPACTS ON OUR WEATHER TODAY. THE OLD STALLED FRONT APPEARS TO LIE ALONG THE BEACHES OF PENDER AND NEW HANOVER COUNTIES... EXTENDING SOUTHWARD FROM SOUTHPORT TO AN AREA OF LOW PRESSURE OFF THE GEORGIA COAST. THIS FEATURE SHOULD BE DRAWN EASTWARD BEHIND BERTHA TODAY...WITH DRIER AIR GRADUALLY BUILDING IN FROM THE NORTH WITH TIME. RADAR SHOWS PLENTY OF SHOWERS ACROSS THE COASTAL WATERS. THESE ARE SHALLOW CONVECTIVE FEATURES WITH ECHO TOPS GENERALLY 20KFT OR LESS...EXCEPT FOR A FEW T-STORMS FARTHER OFFSHORE WITH TOPS OVER 30KFT. SINCE THE BULK OF THIS ACTIVITY IS SHALLOW IT IS BEING STEERED BY THE 700-850 MB MEAN FLOW WHICH IS CURRENTLY FROM THE EAST. THE 00Z GFS AND 06Z RUC (OUR PREFERRED MODELS TODAY) SHOW THIS STEERING FLOW BACKING MORE NORTHERLY WITH TIME WHICH SHOULD TEND TO LIMIT HOW FAR INLAND ANY SHOWER ACTIVITY WILL MOVE. FORECAST POPS RANGE FROM 30-50 PERCENT ALONG THE COAST THIS MORNING...DIMINISHING TO 20-30 PERCENT BY NOON. FOR INTERIOR SECTIONS OF THE EASTERN CAROLINAS UNLESS AN ISOLATED SHOWER CAN DEVELOP DURING THE AFTERNOON DRY WEATHER IS EXPECTED. HIGHS SHOULD RANGE FROM THE UPPER 80S TO NEAR 90 ACROSS THE SC PEE DEE REGION TO THE MID 80S AT THE COAST. FOR TONIGHT DRY AIR SHOULD FLOOD IN THROUGHOUT THE TROPOSPHERE WITH PRECIPITABLE WATER VALUES FALLING TO LESS THAN 1.5 INCHES. SKIES SHOULD BECOME MAINLY CLEAR BY EARLY EVENING AND THERE IS LITTLE POTENTIAL FOR FOG OR LOW STRATUS OVERNIGHT. LOWS SHOULD TO NEAR 70. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 AM TUESDAY...SUMMER RETURNS ON WEDNESDAY AS THE MID LEVEL FLOW GOES WESTERLY AND DOWNSLOPE ALLOWING FOR A PARTLY SUNNY AFTERNOON. PIEDMONT TROUGH DEVELOPS BUT IT ALONG WITH THE SEA BREEZE WILL GENERALLY BE TOO MOISTURE-DEPRIVED TO LEAD TO MEANINGFUL PRECIP CHANCES. AFTERNOON TEMPERATURES WILL BE NEAR OR A FEW DEGREES ABOVE CLIMO. PIEDMONT TROUGH PUSHES TOWARDS THE COAST ON THURSDAY WHILE A MID LEVEL SHORTWAVE PASSES OVERHEAD LATE IN THE AFTERNOON. NORMALLY THIS WOULD BE A GOOD SETUP FOR THUNDERSTORMS. HOWEVER THERE IS STILL VERY LITTLE MOISTURE ESPECIALLY THROUGH THE MID LEVELS. CONVECTION WILL BE LIMITED AND GENERALLY BE CONFINED TO THE COASTAL REGIONS. TEMPERATURES WILL BE QUITE SIMILAR TO THOSE OF WEDNESDAY. A COLD FRONT WILL ENTER THE REGION LATE THURSDAY NIGHT AND WILL KEEP ISOLATED SHOWERS AND THUNDERSTORMS IN THE FORECAST. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 3 AM TUESDAY...HIGH PRESSURE BUILDING IN FROM THE NORTH BEHIND THURSDAY NIGHT COLD FRONT TO END THE BRIEF SHORT TERM PERIODS SUMMER TEMPS. MOISTURE MAY POOL ALONG THE FRONT AND BRING SOME SLIGHT RAIN CHANCES OVER SWRN ZONES. THIS WILL HOLD TRUE INTO SATURDAY AS THE FRONT WASHES BACK CLOSER TO THE AREA...THE LOW RAIN CHANCES MAY INCREASE IN AREA WHILE AFTERNOON HIGHS REMAIN CAPPED BELOW CLIMO. SUNDAY IS WHEN RAIN CHANCES SHOULD RETURN AREA-WIDE AS THE FRONT LIFTS BACK INTO THE REGION. WAVE MOVES BY LATE SUNDAY INTO SUNDAY NIGHT POSSIBLY FURTHER RAMPING UP RAIN CHANCES...AND THEN LEAVING THE BOUNDARY IN OUR PRESENCE SANS WAVE ON MONDAY. CYCLONIC AND NWRLY MID LEVEL FLOW CONTINUES ON TUESDAY WITH SURFACE TROUGHINESS REDEVELOPING. RAIN CHANCES WILL LINGER INTO TUESDAY WITH CLIMO OR HIGHER CHANCES WHILE TEMPS REMAIN NEAR OR JUST SHY OF CLIMO. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... AS OF 12Z...QUITE A BIT OF LIFR CONDITIONS AROUND THE CWA...WHICH WILL LIKELY PERSIST FOR TWO OR THREE HOURS. SOME LIGHT SHOWERS NEAR THE COAST...NOT ASSOCIATED WITH TROPICAL STORM BERTHA. NOT LOOKING FOR THAT MUCH CONVECTION TODAY...MAYBE ILM. LOW PRESSURE OFF THE SOUTH CAROLINA COAST WILL FLING SOME LIGHT MOISTURE ONSHORE TO NORTH CAROLINA. THE LOW WILL PULL NORTHEAST THIS AFTERNOON...TAKING ITS MOISTURE WITH IT. SOME LOW LEVEL MOISTURE WILL REMAIN TONIGHT...HOWEVER MUCH LESS FOG/STRATUS THAN THIS MORNING. EXTENDED OUTLOOK...ISOLATED SHOWERS WED. SCATTERED SHOWERS LATE THURSDAY WITH A BETTER CHANCE FOR CONVECTION FRIDAY AND SATURDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 645 AM TUESDAY...A CYCLONIC CIRCULATION IN RADAR IMAGERY LOCATED ABOUT 60 MILES SOUTH OF OAK ISLAND IS THE FEATURE TO WATCH THIS MORNING. THE LATEST HRRR MODEL SEEMS TO HAVE INITIALIZED THIS SWIRL AND MOVES IT SLOWLY NORTHEASTWARD...MISSING THE TIP OF CAPE FEAR ABOUT 20 MILES TO THE EAST BETWEEN NOON AND 1 PM EDT. LACK OF MARINE OBSERVATIONS WEST OF THE LOW IS HINDERING ANALYSIS...BUT NOAA BUOY 41004 EAST OF CHARLESTON HAS NOT GUSTED ANY HIGHER THAN 17 KNOTS IN THE PAST FEW HOURS. WAVE HEIGHTS AT THE LOCAL BUOYS HAVE CHANGED LITTLE FROM 3 AM AND NO CHANGES ARE NEEDED THERE. PREVIOUS DISCUSSION FROM 300 AM FOLLOWS... AN OLD STALLED FRONT RUNS ALONG THE BEACHES OF SE NORTH CAROLINA SOUTHWARD INTO AN AREA OF LOW PRESSURE OFF THE GEORGIA COAST. HURRICANE BERTHA IS WELL EAST OF THE CAROLINAS AND WILL MOVE NORTHEASTWARD AND FARTHER AWAY TODAY. THE GEORGIA LOW AND OUR FRONT SHOULD BE DRAWN OFFSHORE TOWARD BERTHA...LEADING TO A DRYING TREND DEVELOPING WITH TIME. UNTIL THEN...WAVES OF SHOWERS AND EMBEDDED T-STORMS ACROSS THE COASTAL WATERS SHOULD CONTINUE THROUGH THE MORNING HOURS. GENERALLY EAST OR NORTHEAST WINDS WILL TURN NORTHERLY THIS EVENING...THEN WESTERLY OVERNIGHT AS BERTHA PULLS THE LOW AND FRONT AWAY FROM THE AREA. THIS WILL LET DRIER AIR FLOOD INTO THE AREA. A SIGNIFICANT SWELL FROM BERTHA WILL IMPACT THE WATERS TODAY AND SHOULD BE THE LARGEST CONTRIBUTING FACTOR IN SEA HEIGHT FORECASTS TODAY. SEAS OF 4-5 FEET ARE EXPECTED...DIMINISHING TO 3-4 FT LATE TONIGHT. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 AM TUESDAY...PIEDMONT TROUGH ON WEDNESDAY WILL BACK INITIALLY WEST FLOW TO SOUTHWEST OR EVEN SOUTH WHILE ADDING A FEW KNOTS TO AVERAGE SPEED. SEAS MAINLY COMPRISED OF WIND WAVES IN THE 2 TO 3 FT RANGE. AS THE BOUNDARY MOVES TOWARDS THE COAST ON THURSDAY THE WIND WILL DIMINISH LATER IN THE DAY AS THE GRADIENT IS PUSHED OUT TO SEA BY THE TROUGH. THE BOUNDARY WILL SINK SOUTH ACROSS THE ZONES RATHER SLOWLY LATE THURSDAY NIGHT BRINGING A TURN TO NORTHERLY WINDS FOLLOWED BY ADDITIONAL VEERING TO EASTERLY BY THE PERIODS END...AT LEAST FOR NORTHERN ZONES. LONG TERM /FRIDAY THROUGH SATURDAY/... AS OF 3 AM TUESDAY...POST-FRONTAL ONSHORE FLOW ON FRIDAY WILL BE IN THE 10 TO 15 KT RANGE EARLY BUT SETTLE BY ABOUT 5 KT. SEAS WILL BE RUNNING JUST 2-3 FEET THEN MOST AREAS. THE HIGH WILL CONTINUE WEDGING IN FROM POINTS NORTH INTO SATURDAY WHILE THE FRONT STALLED TO THE SOUTH TRIES TO MOVE BACK TO THE NORTH SLIGHTLY. WITH RELATIVELY UNCHANGED WINDS AND NO SWELL ENERGY TO SPEAK OF SEAS WILL REMAIN 2 FEET AGAIN ON SATURDAY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...TRA SHORT TERM...MBB LONG TERM...MBB AVIATION...43
AREA FORECAST DISCUSSION
NWS RALEIGH NC
646 AM EDT TUE AUG 5 2014 .SYNOPSIS...LOW PRESSURE MOVES NORTHEAST JUST OFF OF THE CAROLINA COAST TODAY THROUGH THIS EVENING. WEAK HIGH PRESSURE WILL BE LOCATED OVER THE APPALACHIANS. A COLD FRONT MOVES SOUTH OVER THE REGION WEDNESDAY AFTERNOON INTO THURSDAY. && .NEAR TERM /THROUGH TODAY/... AS OF 305 AM TUESDAY... WITH LOW PRESSURE OFF OF THE CAROLINA COAST...THE LATEST IR FOG SATELLITE IMAGE SHOWED THE WESTERN EDGE OF A SHIELD OF MID- AND HIGH- LEVEL CLOUDS MAINLY ALONG AND EAST OF ABOUT U.S. 1...WITH PATCHY CIRRUS TOWARD THE TRIAD. UNDERNEATH THE HIGHER CLOUDS OBSERVATIONS SHOWED SOME LOW CLOUDS HAD FORMED...AND IT WAS NEAR THE WESTERN EDGE OF THE HIGHER CLOUDS THAT VISIBILITIES WERE LOWEST...PARTICULARLY TOWARD KHNZ AND FOR A TIME NEAR KTTA. AS NOTED IN THE AVIATION DISCUSSION BELOW...THE HRRR WRF EARLY THIS MORNING HAS BEEN CONSISTENT IN DEVELOPING THE LOWER-VISIBILITY FOG MAINLY FROM THE TRIANGLE NORTHEAST...WHICH SEEMS REASONABLE GIVEN THE ORIENTATION OF THE CLOUD SHIELD ALOFT AND THE LIGHT NORTHEAST LOW-LEVEL FLOW. THE GRIDDED FORECAST WILL NOTE AREAS OF FOG AND PATCHY DRIZZLE MAINLY FROM THE TRIANGLE NORTH AND NORTHEAST...WITH A SLIGHT CHANCE OF SHOWERS EARLY THIS MORNING ALONG AND EAST OF INTERSTATE 95 IN THE DEEPER MOISTURE CLOSER TO THE COASTAL LOW PRESSURE. WHILE THE RAP AND HRRR WRF ARE DRY IN CENTRAL NORTH CAROLINA TODAY...THE NAM HAS COPIOUS PRECIPITATION OVER A QUARTER-INCH IN A LARGE PART OF THE COASTAL PLAIN TODAY. LEANED WITH THIS FORECAST MORE TOWARD THE DRIER GUIDANCE...AS DRIER MID-LEVEL AIR WAS SLOWLY MOVING EAST INTO THE WESTERN PART OF THE STATE ON THE LATEST WATER VAPOR IMAGERY...AND ONLY WEAK LIFT FORECAST. GFS BUFR SOUNDINGS ARE STABLE...AND MEAN LAYER RELATIVE HUMIDITY IS FORECAST TO DECREASE GRADUALLY DURING THE DAY ON BOTH THE NAM AND GFS AS PRECIPITABLE WATER VALUES ALSO SLOWLY FALL. IT SHOULD BE NOTED THAT WITH THE BETTER MID-LEVEL WINDS MOVING THROUGH EARLY THIS MORNING...THERE HAVE BEEN A COUPLE OF SHOWERS THAT HAVE DEVELOPED VERY BRIEFLY OVER UPSTATE SOUTH CAROLINA. WILL CERTAINLY MONITOR RADAR TRENDS...BUT FOR NOW THE FORECAST WILL ONLY SHOW A SLIGHT CHANCE OF A SHOWER ALONG AND EAST OF ABOUT U.S. 1 WITH A CHANCE OF A SHOWER OR THUNDERSTORM FROM INTERSTATE 95 EAST. 1000- 850MB THICKNESSES SUPPORT HIGHS IN THE UPPER 80S...AND WHEN MORNING CLOUDS ARE CONSIDERED...WILL FORECAST HIGHS IN THE MID TO UPPER 80S UNDER A NORTH-TO-NORTHEAST WIND 10 MPH OR LESS. && .SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/... AS OF 305 AM TUESDAY... BUFR SOUNDINGS ARE STABLE OVERNIGHT ON BOTH THE NAM AND THE GFS...WITH THE GFS IN PARTICULAR SHOWING A SMALL VOLUME OF MID-LEVEL MOISTURE AS THE TROUGH AXIS ALOFT MOVES THROUGH AND A WEAK MID-LEVEL SHORTWAVE FOLLOWS THE TROUGH AXIS OVERNIGHT IN THE NORTHWEST FLOW. THIS SHOULD TRANSLATE INTO A PERIOD OF SCATTERED MID-LEVEL CLOUDS... POSSIBLY BROKEN FOR A PERIOD IF THE GFS VERIFIES. LOW-LEVEL MOISTURE REMAINS BEST TOWARD INTERSTATE 95 AND MAY NOTE PATCHY FOG POSSIBLE IN THE GRIDDED AND WORDED FORECASTS FOR THOSE AREAS LATE TONIGHT INTO VERY EARLY WEDNESDAY. OVERNIGHT LOWS 65 TO 70. WEDNESDAY AND WEDNESDAY NIGHT...GFS BUFR SOUNDINGS ARE STABLE WEDNESDAY...WHILE THE NAM SHOWS MODEST INSTABILITY PARTICULARLY TOWARD KRWI AND KFAY. ALTHOUGH THE GFS POPS ARE LOW THROUGHOUT CENTRAL NORTH CAROLINA...ITS QPF DOES NOTE A MINOR HUNDREDTH OR SO TOWARD THE COASTAL PLAIN WEDNESDAY AFTERNOON. SURFACE DEW POINTS SHOULD GENERALLY MIX WELL BASED ON THE BUFR SOUNDINGS AND A DEVELOPING WESTERLY SURFACE FLOW...MIXING LAST TOWARD THE COASTAL PLAIN WHERE THE COMBINATION OF JUST ENOUGH INSTABILITY...WEAK 850MB CONVERGENCE AND GRADUALLY LOWERING DEW POINTS COULD RESULT IN A VERY ISOLATED SHOWER OR STORM. THE MEAN AIR MASS STARTS TO MOISTEN WEDNESDAY NIGHT WITH THE APPROACH OF THE SURFACE FRONT...BUT WITH ONLY WEAK MID-LEVEL SUPPORT AND JET DYNAMICS NORTH OF THE AREA IN VIRGINIA...WILL LEAN TOWARD THE GFS AS OPPOSED TO THE WET NAM AND SHOW A DRY OVERNIGHT WEDNESDAY WITH AN EXPECTED INCREASE IN MID- LEVEL CLOUDS OVER MUCH OF THE AREA. 1000-850MB THICKNESSES SUPPORT HIGHS OF A BLEND OF MAV AND MET MOS GUIDANCE...OR 90 TO 95. OVERNIGHT LOWS WEDNESDAY NIGHT WITHIN A DEGREE OR THREE OF 70. -DJF THU/THU NIGHT: AN UPPER LEVEL TROUGH OVER NEW ENGLAND WILL LIFT INTO THE CANADIAN MARITIMES THU/THU NIGHT...WITH A WEAKENED WNW FLOW ALOFT OVER THE CAROLINAS. SUBSIDENCE IN THE WAKE OF THE TROUGH WILL RESULT IN SFC PRESSURE RISES OVER THE OH VALLEY AND MID ATLANTIC...WITH AN ATTENDANT SFC RIDGE AXIS /BACKDOOR COLD FRONT/ EXTENDING SOUTHWARD THROUGH VA TOWARD THE NC BORDER LATE THU. UNCERTAINTY PERSISTS W/REGARD TO THE TIMING/PROGRESS OF THE BACK DOOR COLD FRONT...LENDING A FAIR AMOUNT OF UNCERTAINTY TO TEMPERATURES...ESP ALONG AND NORTH OF HWY 64. AT THIS TIME WILL INDICATE HIGHS RANGING FROM ~90F SOUTH TO 83-85F NEAR THE VA BORDER. DESTABILIZATION/FORCING WILL HIGHLY DEPEND ON BOTH THE EVOLUTION OF THE FRONT AND OF SMALL AMPLITUDE DISTURBANCES IN WNW FLOW ALOFT... WITH CONSIDERABLE UNCERTAINTY IN PRECIP CHANCES/COVERAGE. AT THIS TIME WILL INDICATE A SLIGHT CHANCE DURING THE LATE AFTERNOON/EVENING HOURS. -VINCENT && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 330 AM TUESDAY... THE 00Z GFS/ECMWF ARE IN RELATIVELY GOOD AGREEMENT ON THE SYNOPTIC PATTERN FRI-MON. DESPITE GOOD SYNOPTIC AGREEMENT...SIGNIFICANT DISAGREEMENT ON MESOSCALE FEATURES AND CONVECTIVE EVOLUTION THROUGHOUT THE LONG TERM PERIOD LENDS ABOVE NORMAL UNCERTAINTY WITH REGARD TO PRECISE DETAILS (I.E. PRECIP AMOUNTS AND TIMING) FOR THE CAROLINAS. NORTHWEST FLOW ALOFT WILL PREVAIL OVER THE CAROLINAS FRI/SAT... DOWNSTREAM OF AN UPPER LEVEL RIDGE CENTERED OVER THE CENTRAL PLAINS/LOWER MIDWEST. THE UPPER LEVEL RIDGE IS PROGGED TO AMPLIFY AND RETROGRADE INTO THE ROCKIES ON SUN/MON...RESULTING IN A MORE AMPLIFIED PATTERN OF NNW FLOW ALOFT DOWNSTREAM OVER THE CAROLINAS. GIVEN AN ACTIVE UPPER LEVEL PATTERN JUXTAPOSED WITH MID-SUMMER MOISTURE...EXPECT ABOVE NORMAL CHANCES FOR PRECIPITATION AND BELOW NORMAL TEMPERATURES...PARTICULARLY SAT/SUN. -VINCENT && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... AS OF 645 AM TUESDAY... AREAS OF IFR CONDITIONS IN FOG AND LOW CLOUDS WILL CONTINUE OVER MOST OF CENTRAL NORTH CAROLINA DURING THE EARLY MORNING. THE LATEST SATELLITE IMAGES SHOWED SOME LOWER CLOUDS SCATTERED AROUND THE TRIAD...WITH A SHIELD OF HIGHER CLOUDS NOTED OVER THE REST OF CENTRAL NORTH CAROLINA. FOG HAD DEVELOPED...WITH A NARROW BAND OF THE LOWEST VISIBILITY FROM KRDU NORTHEAST. THIS IS WHERE THE HRRR WRF MODEL SHOWED THE BEST POTENTIAL FOR SOLID IFR FOG POTENTIAL ORIGINATING OVER SOUTHERN VIRGINIA WHERE THERE WERE FEWER MID- AND HIGH-LEVEL CLOUDS EARLIER...THEN MOVING SOUTH-SOUTHWEST IN THE LIGHT LOW-LEVEL FLOW. AS LOW PRESSURE MOVES NORTHEAST OFF OF THE CAROLINA COAST THERE IS AN OUTSIDE CHANCE OF A SHOWER MAINLY ALONG AND EAST OF INTERSTATE 95...BUT THE CHANCES SEEM TOO LOW TO INCLUDE IN A TAF POINT FORECAST. VFR CONDITIONS SHOULD PREVAIL OVER CENTRAL NORTH CAROLINA BY AFTERNOON UNDER A NORTHEAST WIND. EVENING WINDS...LIGHT AND VARIABLE...MAY SHOW A TENDENCY TO BECOME LIGHT SOUTHERLY BY 06Z WEDNESDAY. PATCHY FOG AND SUB-VFR CONDITIONS ARE POSSIBLE LATE TONIGHT INTO EARLY WEDNESDAY...WITH THE BETTER CHANCES OF SUCH TOWARD KFAY AND KRWI WHERE THE LOW-LEVEL MOISTURE WILL BE HIGHER OVERNIGHT. BEYOND THE 12Z VALID TAF PERIOD...VFR CONDITIONS ARE ANTICIPATED FOR MUCH OF WEDNESDAY INTO WEDNESDAY NIGHT. BEHIND A COLD FRONT WHICH SETTLES JUST SOUTH OF THE AREA BY LATE THURSDAY...CHANCES FOR PRECIPITATION WILL INCREASE. INTO SATURDAY...THE HIGHER CHANCES AS THEY DEVELOP ARE EXPECTED TO BE OVER THE SOUTHWEST PIEDMONT INTO THE SANDHILLS. STILL...AREAS OF SUB-VFR CONDITIONS IN LOWER CLOUDS ARE POSSIBLE THROUGHOUT MUCH OF CENTRAL NORTH CAROLINA DEVELOPING SATURDAY OR ESPECIALLY SATURDAY NIGHT. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DJF NEAR TERM...DJF SHORT TERM...DJF/VINCENT LONG TERM...VINCENT AVIATION...DJF
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
640 AM EDT TUE AUG 5 2014 .SYNOPSIS... A STALLED FRONT ALONG THE COAST WILL MOVE OFFSHORE TODAY AS HURRICANE BERTHA MOVES PASSES WELL OFFSHORE OF THE CAROLINA COAST. SWELLS FROM BERTHA WILL LEAD TO AN INCREASED RIP CURRENT RISK ALONG AREA BEACHES THE NEXT SEVERAL DAYS. WARM AND MUGGY WEATHER IS EXPECTED WEDNESDAY AND THURSDAY AHEAD OF AN APPROACHING COLD FRONT. HIGH PRESSURE WILL BUILD IN FRIDAY THROUGH THE WEEKEND...LIKELY HOLDING TEMPERATURES DOWN A FEW DEGREES BELOW NORMAL. && .NEAR TERM /THROUGH TONIGHT/... AS OF 3 AM TUESDAY...WE ARE JUST ABOUT TO GET RID OF THE DREARY WEATHER PATTERN THAT HAS BROUGHT UNSEASONABLY COOL...CLOUDY AND RAINY WEATHER TO THE COASTAL CAROLINAS FOR THE ENTIRE MONTH SO FAR. SO FAR AUGUST 2014 HAS SEEN THE 7TH COOLEST TEMPERATURES EVEN OBSERVED IN WILMINGTON WITH AN AVERAGE TEMPERATURE OF ONLY 75.7 DEGREES. HURRICANE BERTHA IS PASSING WELL EAST OF THE CAROLINAS WITH NO DIRECT IMPACTS ON OUR WEATHER TODAY. THE OLD STALLED FRONT APPEARS TO LIE ALONG THE BEACHES OF PENDER AND NEW HANOVER COUNTIES... EXTENDING SOUTHWARD FROM SOUTHPORT TO AN AREA OF LOW PRESSURE OFF THE GEORGIA COAST. THIS FEATURE SHOULD BE DRAWN EASTWARD BEHIND BERTHA TODAY...WITH DRIER AIR GRADUALLY BUILDING IN FROM THE NORTH WITH TIME. RADAR SHOWS PLENTY OF SHOWERS ACROSS THE COASTAL WATERS. THESE ARE SHALLOW CONVECTIVE FEATURES WITH ECHO TOPS GENERALLY 20KFT OR LESS...EXCEPT FOR A FEW T-STORMS FARTHER OFFSHORE WITH TOPS OVER 30KFT. SINCE THE BULK OF THIS ACTIVITY IS SHALLOW IT IS BEING STEERED BY THE 700-850 MB MEAN FLOW WHICH IS CURRENTLY FROM THE EAST. THE 00Z GFS AND 06Z RUC (OUR PREFERRED MODELS TODAY) SHOW THIS STEERING FLOW BACKING MORE NORTHERLY WITH TIME WHICH SHOULD TEND TO LIMIT HOW FAR INLAND ANY SHOWER ACTIVITY WILL MOVE. FORECAST POPS RANGE FROM 30-50 PERCENT ALONG THE COAST THIS MORNING...DIMINISHING TO 20-30 PERCENT BY NOON. FOR INTERIOR SECTIONS OF THE EASTERN CAROLINAS UNLESS AN ISOLATED SHOWER CAN DEVELOP DURING THE AFTERNOON DRY WEATHER IS EXPECTED. HIGHS SHOULD RANGE FROM THE UPPER 80S TO NEAR 90 ACROSS THE SC PEE DEE REGION TO THE MID 80S AT THE COAST. FOR TONIGHT DRY AIR SHOULD FLOOD IN THROUGHOUT THE TROPOSPHERE WITH PRECIPITABLE WATER VALUES FALLING TO LESS THAN 1.5 INCHES. SKIES SHOULD BECOME MAINLY CLEAR BY EARLY EVENING AND THERE IS LITTLE POTENTIAL FOR FOG OR LOW STRATUS OVERNIGHT. LOWS SHOULD TO NEAR 70. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 AM TUESDAY...SUMMER RETURNS ON WEDNESDAY AS THE MID LEVEL FLOW GOES WESTERLY AND DOWNSLOPE ALLOWING FOR A PARTLY SUNNY AFTERNOON. PIEDMONT TROUGH DEVELOPS BUT IT ALONG WITH THE SEA BREEZE WILL GENERALLY BE TOO MOISTURE-DEPRIVED TO LEAD TO MEANINGFUL PRECIP CHANCES. AFTERNOON TEMPERATURES WILL BE NEAR OR A FEW DEGREES ABOVE CLIMO. PIEDMONT TROUGH PUSHES TOWARDS THE COAST ON THURSDAY WHILE A MID LEVEL SHORTWAVE PASSES OVERHEAD LATE IN THE AFTERNOON. NORMALLY THIS WOULD BE A GOOD SETUP FOR THUNDERSTORMS. HOWEVER THERE IS STILL VERY LITTLE MOISTURE ESPECIALLY THROUGH THE MID LEVELS. CONVECTION WILL BE LIMITED AND GENERALLY BE CONFINED TO THE COASTAL REGIONS. TEMPERATURES WILL BE QUITE SIMILAR TO THOSE OF WEDNESDAY. A COLD FRONT WILL ENTER THE REGION LATE THURSDAY NIGHT AND WILL KEEP ISOLATED SHOWERS AND THUNDERSTORMS IN THE FORECAST. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 3 AM TUESDAY...HIGH PRESSURE BUILDING IN FROM THE NORTH BEHIND THURSDAY NIGHT COLD FRONT TO END THE BRIEF SHORT TERM PERIODS SUMMER TEMPS. MOISTURE MAY POOL ALONG THE FRONT AND BRING SOME SLIGHT RAIN CHANCES OVER SWRN ZONES. THIS WILL HOLD TRUE INTO SATURDAY AS THE FRONT WASHES BACK CLOSER TO THE AREA...THE LOW RAIN CHANCES MAY INCREASE IN AREA WHILE AFTERNOON HIGHS REMAIN CAPPED BELOW CLIMO. SUNDAY IS WHEN RAIN CHANCES SHOULD RETURN AREA-WIDE AS THE FRONT LIFTS BACK INTO THE REGION. WAVE MOVES BY LATE SUNDAY INTO SUNDAY NIGHT POSSIBLY FURTHER RAMPING UP RAIN CHANCES...AND THEN LEAVING THE BOUNDARY IN OUR PRESENCE SANS WAVE ON MONDAY. CYCLONIC AND NWRLY MID LEVEL FLOW CONTINUES ON TUESDAY WITH SURFACE TROUGHINESS REDEVELOPING. RAIN CHANCES WILL LINGER INTO TUESDAY WITH CLIMO OR HIGHER CHANCES WHILE TEMPS REMAIN NEAR OR JUST SHY OF CLIMO. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... AS OF 12Z...QUITE A BIT OF LIFR CONDITIONS AROUND THE CWA...WHICH WILL LIKELY PERSIST FOR TWO OR THREE HOURS. SOME LIGHT SHOWERS NEAR THE COAST...NOT ASSOCIATED WITH TROPICAL STORM BERTHA. NOT LOOKING FOR THAT MUCH CONVECTION TODAY...MAYBE ILM. LOW PRESSURE OFF THE SOUTH CAROLINA COAST WILL FLING SOME LIGHT MOISTURE ONSHORE TO NORTH CAROLINA. THE LOW WILL PULL NORTHEAST THIS AFTERNOON...TAKING ITS MOISTURE WITH IT. SOME LOW LEVEL MOISTURE WILL REMAIN TONIGHT...HOWEVER MUCH LESS FOG/STRATUS THAN THIS MORNING. EXTENDED OUTLOOK...ISOLATED SHOWERS WED. SCATTERED SHOWERS LATE THURSDAY WITH A BETTER CHANCE FOR CONVECTION FRIDAY AND SATURDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 3 AM TUESDAY...AN OLD STALLED FRONT RUNS ALONG THE BEACHES OF SE NORTH CAROLINA SOUTHWARD INTO AN AREA OF LOW PRESSURE OFF THE GEORGIA COAST. HURRICANE BERTHA IS WELL EAST OF THE CAROLINAS AND WILL MOVE NORTHEASTWARD AND FARTHER AWAY TODAY. THE GEORGIA LOW AND OUR FRONT SHOULD BE DRAWN OFFSHORE TOWARD BERTHA...LEADING TO A DRYING TREND DEVELOPING WITH TIME. UNTIL THEN...WAVES OF SHOWERS AND EMBEDDED T-STORMS ACROSS THE COASTAL WATERS SHOULD CONTINUE THROUGH THE MORNING HOURS. GENERALLY EAST OR NORTHEAST WINDS WILL TURN NORTHERLY THIS EVENING...THEN WESTERLY OVERNIGHT AS BERTHA PULLS THE LOW AND FRONT AWAY FROM THE AREA. THIS WILL LET DRIER AIR FLOOD INTO THE AREA. A SIGNIFICANT SWELL FROM BERTHA WILL IMPACT THE WATERS TODAY AND SHOULD BE THE LARGEST CONTRIBUTING FACTOR IN SEA HEIGHT FORECASTS TODAY. SEAS OF 4-5 FEET ARE EXPECTED...DIMINISHING TO 3-4 FT LATE TONIGHT. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 AM TUESDAY...PIEDMONT TROUGH ON WEDNESDAY WILL BACK INITIALLY WEST FLOW TO SOUTHWEST OR EVEN SOUTH WHILE ADDING A FEW KNOTS TO AVERAGE SPEED. SEAS MAINLY COMPRISED OF WIND WAVES IN THE 2 TO 3 FT RANGE. AS THE BOUNDARY MOVES TOWARDS THE COAST ON THURSDAY THE WIND WILL DIMINISH LATER IN THE DAY AS THE GRADIENT IS PUSHED OUT TO SEA BY THE TROUGH. THE BOUNDARY WILL SINK SOUTH ACROSS THE ZONES RATHER SLOWLY LATE THURSDAY NIGHT BRINGING A TURN TO NORTHERLY WINDS FOLLOWED BY ADDITIONAL VEERING TO EASTERLY BY THE PERIODS END...AT LEAST FOR NORTHERN ZONES. LONG TERM /FRIDAY THROUGH SATURDAY/... AS OF 3 AM TUESDAY...POST-FRONTAL ONSHORE FLOW ON FRIDAY WILL BE IN THE 10 TO 15 KT RANGE EARLY BUT SETTLE BY ABOUT 5 KT. SEAS WILL BE RUNNING JUST 2-3 FEET THEN MOST AREAS. THE HIGH WILL CONTINUE WEDGING IN FROM POINTS NORTH INTO SATURDAY WHILE THE FRONT STALLED TO THE SOUTH TRIES TO MOVE BACK TO THE NORTH SLIGHTLY. WITH RELATIVELY UNCHANGED WINDS AND NO SWELL ENERGY TO SPEAK OF SEAS WILL REMAIN 2 FEET AGAIN ON SATURDAY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...TRA SHORT TERM...MBB LONG TERM...MBB AVIATION...43
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
933 AM EDT TUE AUG 5 2014 .SYNOPSIS... A WEAK COLD FRONT NEAR LAKE ERIE WILL PUSH SOUTH ACROSS THE AREA TODAY. HIGH PRESSURE WILL PUSH SOUTHEAST OVER THE REGION BY THURSDAY...AND REMAIN OVER THE AREA THROUGH THE WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... PREVIOUS FORECAST LOOKS ON TRACK AND HAVE ONLY MADE MINOR CHANGES TO THE TIMING OF THE CONVECTION THAT WILL DEVELOP. STORMS WILL BE SLOW MOVING BUT NOT AS SLOW AS OVER THE WEEKEND. SO THE SLOWER MOTION AND PRECIPITABLE WATER VALUES APPROACHING AN INCH AND A HALF COULD PRODUCE SOME LOCALLY HEAVY RAINFALL. PREVIOUS DISCUSSION... FIRST IN A SERIES OF TWO S/W TROUGHS WILL MOVE SE ACROSS THE AREA TODAY INDUCING A SURFACE TROUGH NEAR LERI TO MOVE SOUTH OF THE CWA BY TONIGHT. NEITHER THE SHEAR OR INSTABILITY ARE REAL IMPRESSIVE SO GENERALLY NOT EXPECTING MUCH IN THE WAY OF SEVERE STORMS. THE CONVECTION WILL TEND TO SHIFT SOUTH WITH THE TROUGH BUT ALSO TEND TO LINGER ON THE BACK EDGE AS THE MOISTURE HANGS BACK IN RESPONSE TO LIGHT WINDS DOING LITTLE TO FLUSH OUT THE LOW LEVEL MOISTURE. FOR EARLY MORNING UPDATE...DECREASED AND SLOWED POP INCREASE FOR NEXT FEW HOURS BASED ON LATEST DATA AND HRRR/RUC RUN. TEMPS TODAY WILL BE A LITTLE COOLER THAN YDAY DUE TO THE ADDED CLOUDS AND WINDS SHIFTING MORE TO THE NORTH. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/... LINGERING MOISTURE AND UPPER TROUGHING SHOULD KEEP A THREAT FOR SHRA AND SOME THUNDER GOING TONIGHT FOR MOST OF THE AREA. THE SECOND S/W WILL DROP SE THRU THE REGION WED HELPING TO INDUCE CONVECTION. HOWEVER...LOW LEVEL FLOW WILL BE MAINLY N TO NE WHICH WILL LIMIT CONVERGENCE SO WILL PROBABLY JUST SEE SCATTERED COVERAGE WITH THE BETTER CHANCE PROBABLY OVER THE SOUTH HALF OF THE CWA. ONCE AGAIN...CONVECTIVE PARAMETERS ARE NOT OVERLY STRONG SO NO ORGANIZED SEVERE STORMS LOOK LIKELY. TEMPS WED SHOULD BE SIMILAR TO TUE AS NO SIGNIFICANT AIRMASS CHANGE HAS TAKEN PLACE. DRIER AIR SLOWLY FILTERS SOUTH INTO THE AREA WED NIGHT WHICH SHOULD SHIFT THE THREAT OF PRECIP SOUTH SO THINK THE RAIN SHOULD BE DONE THROUGHOUT THE CWA BY ABOUT MIDNIGHT WED NIGHT. TEMPS WED NIGHT SHOULD GET INTO A 55 TO 60 RANGE FOR MOST PLACES AS LIGHT N TO NE WINDS PERSIST AND CLOUDS DECREASE. THE NAM REMAINS CONSISTENT IN DEVELOPING A CONVECTIVE COMPLEX ON THE NE SIDE OF A LOW WED NIGHT IN IA AND MOVING THE COMPLEX ESE TO CROSS THE SW PART OF THE CWA LATE THU/THU NIGHT. NOT SEEING THIS ON OTHER MODELS ALTHOUGH THE GFS HAS INCHED SOME QPF INTO SW OH THU NIGHT. WILL MAINLY KEEP FORECAST DRY THU/THU NIGHT BUT WILL ALLOW FOR MORE CLOUDINESS OVER THE SW AND INTRODUCE A SLIGHT CHANCE POP. DAYTIME TEMPS THU AND FRI SHOULD BE PLEASANT WITH HIGHS MOSTLY IN THE MID TO UPPER 70S AND LOWS THU NIGHT IN THE 50S. && .LONG TERM /SATURDAY THROUGH MONDAY/... THE MODELS ARE NOT IN AGREEMENT WITH THIS PORTION OF THE FORECAST. THE 00Z GFS...00Z ECMWF AND CANADIAN MODEL SEEM TO HAVE THE SAME SURFACE AND UPPER AIR FEATURES...HOWEVER...THE ECMWF IS MUCH DRIER OVER THE WEEKEND AND THEN BY MONDAY IT HAS MORE MOISTURE TO SUPPORT SOME SHOWERS AND THUNDERSTORMS. EVEN OVER THE WEEKEND WITH HIGH PRESSURE TO THE NORTH OF THE FORECAST AREA...LOW PRESSURE IS OVER THE OHIO VALLEY AND SOME PRECIPITATION IS JUST SOUTH OF THE FORECAST AREA. AT THIS TIME KEPT THE WEEKEND DRY AND WENT WITH 20 POPS FOR MONDAY. TEMPERATURES WILL BE NEAR NORMAL. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... A WEAK COLD FRONT WILL BE MOVING FROM NORTH TO SOUTH TODAY...THE FRONT SHOULD BE SOUTH OF THE FORECAST AREA AROUND DARK. THE FRONT WILL MOVE THROUGH SLOWLY. THE TIMING OF THE SHOWERS AND THUNDERSTORMS IS NOT CLEAR CUT. A BATCH OF SHOWERS OVER NORTHERN INDIANA WILL DECREASE AS THEY MOVE EAST...SOME SHOWERS COULD GET INTO NORTHWEST OHIO AFTER DAYBREAK AND THEN CONTINUE TO WEAKEN AS THEY MOVE EAST. GOING ALONG WITH THE HRRR MODEL IN DEVELOPING SHOWERS AND THUNDERSTORMS BY EARLY IN THE AFTERNOON. MVFR OR IFR VISIBILITIES IN THE HEAVIER STORMS. OUTLOOK...NON VFR IN AREAS OF FOG WEDNESDAY MORNING. && .MARINE... A WEAK COLD FRONT WILL BE MOVING ACROSS LAKE ERIE FROM THE NORTH TODAY. SOME THUNDERSTORMS COULD OCCUR OVER THE LAKE...IT IS POSSIBLE THAT SOME OF THEM COULD PROMPT THE NEED FOR A SPECIAL MARINE WARNING. OTHERWISE BEHIND THE FRONT THE WINDS WILL BE FROM A NORTHERLY DIRECTION AS HIGH PRESSURE BUILDS IN FROM THE NORTHWEST. THE HIGH WILL SHIFT EAST OF LAKE ERIE FOR THE WEEKEND WITH THE WINDS BECOMING SOUTHERLY. IN THE MEANTIME NOT EXPECTING THE WINDS TO BE STRONG ENOUGH TO CAUSE 3 TO 5 FOOT WAVES...BUT THIS WILL HAVE TO BE MONITORED AS THAT DIRECTION CAN BE TRICKY. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...ADAMS NEAR TERM...ADAMS/MULLEN SHORT TERM...ADAMS LONG TERM...KIELTYKA AVIATION...KIELTYKA MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
708 AM EDT TUE AUG 5 2014 .SYNOPSIS... A WEAK COLD FRONT NEAR LAKE ERIE WILL PUSH SOUTH ACROSS THE AREA TODAY. HIGH PRESSURE WILL PUSH SOUTHEAST OVER THE REGION BY THURSDAY...AND REMAIN OVER THE AREA THROUGH THE WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... FIRST IN A SERIES OF TWO S/W TROUGHS WILL MOVE SE ACROSS THE AREA TODAY INDUCING A SURFACE TROUGH NEAR LERI TO MOVE SOUTH OF THE CWA BY TONIGHT. NEITHER THE SHEAR OR INSTABILITY ARE REAL IMPRESSIVE SO GENERALLY NOT EXPECTING MUCH IN THE WAY OF SEVERE STORMS. THE CONVECTION WILL TEND TO SHIFT SOUTH WITH THE TROUGH BUT ALSO TEND TO LINGER ON THE BACK EDGE AS THE MOISTURE HANGS BACK IN RESPONSE TO LIGHT WINDS DOING LITTLE TO FLUSH OUT THE LOW LEVEL MOISTURE. FOR EARLY MORNING UPDATE...DECREASED AND SLOWED POP INCREASE FOR NEXT FEW HOURS BASED ON LATEST DATA AND HRRR/RUC RUN. TEMPS TODAY WILL BE A LITTLE COOLER THAN YDAY DUE TO THE ADDED CLOUDS AND WINDS SHIFTING MORE TO THE NORTH. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/... LINGERING MOISTURE AND UPPER TROUGHING SHOULD KEEP A THREAT FOR SHRA AND SOME THUNDER GOING TONIGHT FOR MOST OF THE AREA. THE SECOND S/W WILL DROP SE THRU THE REGION WED HELPING TO INDUCE CONVECTION. HOWEVER...LOW LEVEL FLOW WILL BE MAINLY N TO NE WHICH WILL LIMIT CONVERGENCE SO WILL PROBABLY JUST SEE SCATTERED COVERAGE WITH THE BETTER CHANCE PROBABLY OVER THE SOUTH HALF OF THE CWA. ONCE AGAIN...CONVECTIVE PARAMETERS ARE NOT OVERLY STRONG SO NO ORGANIZED SEVERE STORMS LOOK LIKELY. TEMPS WED SHOULD BE SIMILAR TO TUE AS NO SIGNIFICANT AIRMASS CHANGE HAS TAKEN PLACE. DRIER AIR SLOWLY FILTERS SOUTH INTO THE AREA WED NIGHT WHICH SHOULD SHIFT THE THREAT OF PRECIP SOUTH SO THINK THE RAIN SHOULD BE DONE THROUGHOUT THE CWA BY ABOUT MIDNIGHT WED NIGHT. TEMPS WED NIGHT SHOULD GET INTO A 55 TO 60 RANGE FOR MOST PLACES AS LIGHT N TO NE WINDS PERSIST AND CLOUDS DECREASE. THE NAM REMAINS CONSISTENT IN DEVELOPING A CONVECTIVE COMPLEX ON THE NE SIDE OF A LOW WED NIGHT IN IA AND MOVING THE COMPLEX ESE TO CROSS THE SW PART OF THE CWA LATE THU/THU NIGHT. NOT SEEING THIS ON OTHER MODELS ALTHOUGH THE GFS HAS INCHED SOME QPF INTO SW OH THU NIGHT. WILL MAINLY KEEP FORECAST DRY THU/THU NIGHT BUT WILL ALLOW FOR MORE CLOUDINESS OVER THE SW AND INTRODUCE A SLIGHT CHANCE POP. DAYTIME TEMPS THU AND FRI SHOULD BE PLEASANT WITH HIGHS MOSTLY IN THE MID TO UPPER 70S AND LOWS THU NIGHT IN THE 50S. && .LONG TERM /SATURDAY THROUGH MONDAY/... THE MODELS ARE NOT IN AGREEMENT WITH THIS PORTION OF THE FORECAST. THE 00Z GFS...00Z ECMWF AND CANADIAN MODEL SEEM TO HAVE THE SAME SURFACE AND UPPER AIR FEATURES...HOWEVER...THE ECMWF IS MUCH DRIER OVER THE WEEKEND AND THEN BY MONDAY IT HAS MORE MOISTURE TO SUPPORT SOME SHOWERS AND THUNDERSTORMS. EVEN OVER THE WEEKEND WITH HIGH PRESSURE TO THE NORTH OF THE FORECAST AREA...LOW PRESSURE IS OVER THE OHIO VALLEY AND SOME PRECIPITATION IS JUST SOUTH OF THE FORECAST AREA. AT THIS TIME KEPT THE WEEKEND DRY AND WENT WITH 20 POPS FOR MONDAY. TEMPERATURES WILL BE NEAR NORMAL. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... A WEAK COLD FRONT WILL BE MOVING FROM NORTH TO SOUTH TODAY...THE FRONT SHOULD BE SOUTH OF THE FORECAST AREA AROUND DARK. THE FRONT WILL MOVE THROUGH SLOWLY. THE TIMING OF THE SHOWERS AND THUNDERSTORMS IS NOT CLEAR CUT. A BATCH OF SHOWERS OVER NORTHERN INDIANA WILL DECREASE AS THEY MOVE EAST...SOME SHOWERS COULD GET INTO NORTHWEST OHIO AFTER DAYBREAK AND THEN CONTINUE TO WEAKEN AS THEY MOVE EAST. GOING ALONG WITH THE HRRR MODEL IN DEVELOPING SHOWERS AND THUNDERSTORMS BY EARLY IN THE AFTERNOON. MVFR OR IFR VISIBILITIES IN THE HEAVIER STORMS. OUTLOOK...NON VFR IN AREAS OF FOG WEDNESDAY MORNING. && .MARINE... A WEAK COLD FRONT WILL BE MOVING ACROSS LAKE ERIE FROM THE NORTH TODAY. SOME THUNDERSTORMS COULD OCCUR OVER THE LAKE...IT IS POSSIBLE THAT SOME OF THEM COULD PROMPT THE NEED FOR A SPECIAL MARINE WARNING. OTHERWISE BEHIND THE FRONT THE WINDS WILL BE FROM A NORTHERLY DIRECTION AS HIGH PRESSURE BUILDS IN FROM THE NORTHWEST. THE HIGH WILL SHIFT EAST OF LAKE ERIE FOR THE WEEKEND WITH THE WINDS BECOMING SOUTHERLY. IN THE MEANTIME NOT EXPECTING THE WINDS TO BE STRONG ENOUGH TO CAUSE 3 TO 5 FOOT WAVES...BUT THIS WILL HAVE TO BE MONITORED AS THAT DIRECTION CAN BE TRICKY. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...ADAMS NEAR TERM...ADAMS SHORT TERM...ADAMS LONG TERM...KIELTYKA AVIATION...KIELTYKA MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
610 AM EDT TUE AUG 5 2014 .SYNOPSIS... A WEAK COLD FRONT NEAR LAKE ERIE WILL PUSH SOUTH ACROSS THE AREA TODAY. HIGH PRESSURE WILL PUSH SOUTHEAST OVER THE REGION BY THURSDAY...AND REMAIN OVER THE AREA THROUGH THE WEEKEND. && .NEAR TERM /UNTIL 6 PM TUESDAY EVENING/... FIRST IN A SERIES OF TWO S/W TROUGHS WILL MOVE SE ACROSS THE AREA TODAY INDUCING A SURFACE TROUGH NEAR LERI TO MOVE SOUTH OF THE CWA BY TONIGHT. NEITHER THE SHEAR OR INSTABILITY ARE REAL IMPRESSIVE SO GENERALLY NOT EXPECTING MUCH IN THE WAY OF SEVERE STORMS. THE CONVECTION WILL TEND TO SHIFT SOUTH WITH THE TROUGH BUT ALSO TEND TO LINGER ON THE BACK EDGE AS THE MOISTURE HANGS BACK IN RESPONSE TO LIGHT WINDS DOING LITTLE TO FLUSH OUT THE LOW LEVEL MOISTURE. FOR EARLY MORNING UPDATE...DECREASED AND SLOWED POP INCREASE FOR NEXT FEW HOURS BASED ON LATEST DATA AND HRRR/RUC RUN. TEMPS TODAY WILL BE A LITTLE COOLER THAN YDAY DUE TO THE ADDED CLOUDS AND WINDS SHIFTING MORE TO THE NORTH. && .SHORT TERM /6 PM TUESDAY EVENING THROUGH FRIDAY NIGHT/... LINGERING MOISTURE AND UPPER TROUGHING SHOULD KEEP A THREAT FOR SHRA AND SOME THUNDER GOING TONIGHT FOR MOST OF THE AREA. THE SECOND S/W WILL DROP SE THRU THE REGION WED HELPING TO INDUCE CONVECTION. HOWEVER...LOW LEVEL FLOW WILL BE MAINLY N TO NE WHICH WILL LIMIT CONVERGENCE SO WILL PROBABLY JUST SEE SCATTERED COVERAGE WITH THE BETTER CHANCE PROBABLY OVER THE SOUTH HALF OF THE CWA. ONCE AGAIN...CONVECTIVE PARAMETERS ARE NOT OVERLY STRONG SO NO ORGANIZED SEVERE STORMS LOOK LIKELY. TEMPS WED SHOULD BE SIMILAR TO TUE AS NO SIGNIFICANT AIRMASS CHANGE HAS TAKEN PLACE. DRIER AIR SLOWLY FILTERS SOUTH INTO THE AREA WED NIGHT WHICH SHOULD SHIFT THE THREAT OF PRECIP SOUTH SO THINK THE RAIN SHOULD BE DONE THROUGHOUT THE CWA BY ABOUT MIDNIGHT WED NIGHT. TEMPS WED NIGHT SHOULD GET INTO A 55 TO 60 RANGE FOR MOST PLACES AS LIGHT N TO NE WINDS PERSIST AND CLOUDS DECREASE. THE NAM REMAINS CONSISTENT IN DEVELOPING A CONVECTIVE COMPLEX ON THE NE SIDE OF A LOW WED NIGHT IN IA AND MOVING THE COMPLEX ESE TO CROSS THE SW PART OF THE CWA LATE THU/THU NIGHT. NOT SEEING THIS ON OTHER MODELS ALTHOUGH THE GFS HAS INCHED SOME QPF INTO SW OH THU NIGHT. WILL MAINLY KEEP FORECAST DRY THU/THU NIGHT BUT WILL ALLOW FOR MORE CLOUDINESS OVER THE SW AND INTRODUCE A SLIGHT CHANCE POP. DAYTIME TEMPS THU AND FRI SHOULD BE PLEASANT WITH HIGHS MOSTLY IN THE MID TO UPPER 70S AND LOWS THU NIGHT IN THE 50S. && .LONG TERM /SATURDAY THROUGH MONDAY/... THE MODELS ARE NOT IN AGREEMENT WITH THIS PORTION OF THE FORECAST. THE 00Z GFS...00Z ECMWF AND CANADIAN MODEL SEEM TO HAVE THE SAME SURFACE AND UPPER AIR FEATURES...HOWEVER...THE ECMWF IS MUCH DRIER OVER THE WEEKEND AND THEN BY MONDAY IT HAS MORE MOISTURE TO SUPPORT SOME SHOWERS AND THUNDERSTORMS. EVEN OVER THE WEEKEND WITH HIGH PRESSURE TO THE NORTH OF THE FORECAST AREA...LOW PRESSURE IS OVER THE OHIO VALLEY AND SOME PRECIPITATION IS JUST SOUTH OF THE FORECAST AREA. AT THIS TIME KEPT THE WEEKEND DRY AND WENT WITH 20 POPS FOR MONDAY. TEMPERATURES WILL BE NEAR NORMAL. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... A WEAK COLD FRONT WILL BE MOVING FROM NORTH TO SOUTH TODAY...THE FRONT SHOULD BE SOUTH OF THE FORECAST AREA AROUND DARK. THE FRONT WILL MOVE THROUGH SLOWLY. THE TIMING OF THE SHOWERS AND THUNDERSTORMS IS NOT CLEAR CUT. A BATCH OF SHOWERS AND THUNDERSTORMS OVER NORTHWEST INDIANA WILL DECREASE AS THEY MOVE EAST...SOME SHOWERS COULD GET INTO NW OHIO AFTER DAYBREAK AND THEN CONTINUE TO WEAKEN AS THEY MOVE EAST. GOING ALONG WITH THE HRRR MODEL IN DEVELOPING SHOWERS AND THUNDERSTORMS EARLY IN THE AFTERNOON. MVFR OR IFR VISIBILITIES IN THE HEAVIER STORMS. OUTLOOK...NON VFR IN AREAS OF FOG WEDNESDAY MORNING. && .MARINE... A WEAK COLD FRONT WILL BE MOVING ACROSS LAKE ERIE FROM THE NORTH TODAY. SOME THUNDERSTORMS COULD OCCUR OVER THE LAKE...IT IS POSSIBLE THAT SOME OF THEM COULD PROMPT THE NEED FOR A SPECIAL MARINE WARNING. OTHERWISE BEHIND THE FRONT THE WINDS WILL BE FROM A NORTHERLY DIRECTION AS HIGH PRESSURE BUILDS IN FROM THE NORTHWEST. THE HIGH WILL SHIFT EAST OF LAKE ERIE FOR THE WEEKEND WITH THE WINDS BECOMING SOUTHERLY. IN THE MEANTIME NOT EXPECTING THE WINDS TO BE STRONG ENOUGH TO CAUSE 3 TO 5 FOOT WAVES...BUT THIS WILL HAVE TO BE MONITORED AS THAT DIRECTION CAN BE TRICKY. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...ADAMS NEAR TERM...ADAMS SHORT TERM...ADAMS LONG TERM...KIELTYKA AVIATION...KIELTYKA MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1045 AM EDT TUE AUG 5 2014 .SYNOPSIS... A COLD FRONT WILL PUSH SOUTHEAST ACROSS THE STATE THIS AFTERNOON AND EVENING. A STRONGER COLD FRONT WILL MOVE THROUGH THE COMMONWEALTH WEDNESDAY FOLLOWED BY COOLER AND LESS HUMID CONDITIONS THAT WILL FOLLOW FOR LATE WEDNESDAY INTO THIS UPCOMING WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... EARLY MORNING FOG HAS PRETTY MUCH DISSIPATED LEAVING MOST OF THE REGION BRIGHT AND SUNNY...ALBEIT SOMEWHAT HAZY. CLOUDS ARE ENCROACHING OVER THE NW ASSOCIATED WITH A WEAK COLD FRONT THAT IS MOVING INTO CENTRAL OHIO. THIS WILL BRING INCREASING CHANCES FOR CONVECTION TODAY...ESPECIALLY OVER THE NWRN THIRD TO HALF OF THE FCST AREA. MODELS SHOW SOME MODERATE INSTABILITY DEVELOPING TODAY BUT WINDS ARE EXPECTED TO REMAIN WEAK SO SEVERE THREAT SHOULD BE MINIMAL. THE LATEST HRRR AND WRF ARW WERE BLENDED WITH THE 03Z SREF TO PAINT TIMING AND AREAL COVERAGE DETAILS INTO OUR POP AND WEATHER GRID DATABASE FOR THE ANTICIPATED SHOWERS AND SCATTERED TSRA THAT WILL IMPACT MAINLY THE NW HALF OF THE CWA DURING THE MIDDAY AND AFTERNOON HOURS TODAY. THE FRONTAL BOUNDARY WILL GRADUALLY WEAKEN AND SLOW AS IT EDGES TWD THE LAURELS AND LOWER SUSQ VALLEY TONIGHT...WITH ISOLATED TO WIDELY SCATTERED TSRA DRIFTING INTO THAT REGION LATER THIS EVENING. BASIN AVERAGE RAINFALL ENDING AT 00Z WED RANGE FROM ONE- TENTH...TO ONE-QUARTER OF AN INCH ACROSS THE NRN MTNS...TO JUST A FEW HUNDREDTHS AT BEST IN THE FAR SE. CONSENSUS BLEND OF ALL MODEL GUIDANCE YIELDS A HIGH TEMP IN THE MID TO UPPER 70S ACROSS THE NRN MTNS AND LAUREL HIGHLANDS...AND MID TO UPPER 80S THROUGHOUT THE VALLEYS OF CENTRAL AND SERN PENN. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... THE SCATTERED SHRA/TSRA LATE THIS AFTERNOON/EVENING ASSOCIATED WITH A WEAK COLD FRONT /AND PRE-FRONTAL TROUGH/ SHOULD DECREASE IN CVRG TONIGHT INTO EARLY WED WITH THE LOSS OF DAYTIME HEATING/INSTABILITY. CONCERNED THAT THE APPROACH OF A STRONG /90 KT/ 300 MB JET AND INCREASING DEEP LAYER UVVEL/STRONG PVA ASSOCIATED WITH THE THERMALLY INDIRECT TRANSVERSE CIRCULATION OF ITS LEFT EXIT REGION WILL SPARK A SEVERAL TO 6-HOUR PERIOD OF MORE NUMEROUS SHOWERS AND TSRA PRECEDING A SECONDARY CFRONT VERY EARLY WED ACROSS THE FAR WEST...AND DURING THE MID MORNING THROUGH MID AFTERNOON HOURS ACROSS THE CENTRAL AND SE ZONES. THE POTENTIAL FEW ROUNDS OF SHOWERS AND TSRA ALONG AND AHEAD OF THIS SECONDARY CFRONT SHOULD BE THE LAST DECENT OPPORTUNITY FOR RAINFALL HERE IN CENTRAL PA FOR AT LEAST 2-3 DAYS. 0-3 KM BULK SHEAR DOES HOWEVER INCREASED TO 25-30 KTS FROM THE WEST TO SOUTHWEST WEDNESDAY...WITH 0-6KM BULK SHEAR OF 40-45 KTS ACROSS NRN PENN IN THE MORNING...AND A RIBBON OF 50-60 KT SHEAR ACRS SOUTHERN PENN LATE WED AFTERNOON. HOWEVER... THE DY2 SPC CONVECTIVE OUTLOOK CONTINUES TO INDICATE ONLY FOR GENERAL THUNDER...WITH THE STG-SVR STORM THREAT LIMITED BY THE APPARENT LACK OF DEEP LYR MSTR/AVG PWS AND CAPE. WOULDN/T BE SURPRISED TO SEE THIS INCREASED TO A SEE TEXT /OR EVEN A COMPACT SLIGHT RISK AREA ACROSS PENN/ WITH LATER UPDATES. STRONG SUBSIDENCE BENEATH THE LEFT ENTRANCE REGION OF THE JET WILL LEAD TO CLEARING AND A RELATIVE MIN OF PRECIP ACROSS THE NRN THIRD TO HALF OF THE STATE AFTER 21Z WED...WHILE ISOLATED TO SCATTERED SHRA/TSRA LINGER ACROSS THE SOUTH. LOW TEMPS TONIGHT UNDER A FAIR AMOUNT OF CLOUD COVER /50-70 PERCENT/ WILL BE IN THE MID 50S TO MID 60S...WITH HIGH TEMPS WEDNESDAY VARYING FROM THE LOWER 70S ACROSS THE NRN MTNS...TO THE LOWER 80S IN THE SE. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... LG SCALE FORCING AND COOLER AIR ALOFT/STEEP MID-LVL LAPSE RATES TIED TO PASSAGE OF UPPER LEVEL TROUGH AXIS MAY PROVIDE ENOUGH LIFT TO GENERATE ISOLD...INSTABILITY TYPE SHOWERS ON THU AFTN. OTHERWISE ANTICIPATE A DRY PERIOD THROUGH THE UPCOMING WEEKEND AND INTO EARLY NEXT WEEK...WITH STRING OF PLEASANT DAYS/COMFORTABLE NIGHTS AS AREA REMAINS UNDER THE INFLUENCE OF SFC HIGH PRES MIGRATING S/SEWD FROM THE UPPER GRT LKS. TEMPS WILL START OUT BELOW AVG BEHIND THE DEPARTING TROUGH AXIS BUT SHOULD MODERATE AS HEIGHTS REBOUND BY 10/11 AUG. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... ALL TERMINALS ARE VFR AS OF 10AM WITH THE EXCEPTION OF SOME LINGERING LOW CLOUDS AND HAZE AT WILLIAMSPORT AND SELINSGROVE. ALL SITES WILL BE VFR BY MID DAY AND THIS WILL CONTINUE INTO THE AFTERNOON. FOR TODAY...CLOUDS WILL REMAIN FEW TO SCATTERED IN THE SE HALF OF CWA...BUT A WEAK FRONTAL SYSTEM SLIDING INTO THE NW WILL BRING LOCAL REDUCTIONS IN SCATTERED AFTERNOON SHOWERS AND TSTMS. WINDS WILL REMAIN LIGHT EXCEPT IN THE THUNDERSTORMS. SCT MVFR RESTRICTIONS WILL BE POSSIBLE AGAIN TONIGHT ALONG WITH LINGERING CHANCES FOR SHOWERS MAINLY ACROSS THE NORTHWEST. SCT SHOWERS AND TSTMS WILL ONCE AGAIN RETURN FOR WEDNESDAY WITH A SECONDARY STRONGER COLD FRONT. OUTLOOK... TUE...SCATTERED SHRA/TSRA WITH APPROACHING COLD FRONT...MAINLY NW. WED...SCATTERED SHRA/TSRA. THU-SAT...MAINLY VFR. PATCHY FOG POSSIBLE EARLY. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE/LAMBERT NEAR TERM...LA CORTE/LAMBERT SHORT TERM...LAMBERT LONG TERM...LAMBERT/STEINBUGL AVIATION...LA CORTE/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
749 AM EDT TUE AUG 5 2014 .SYNOPSIS... A RIDGE OF HIGH PRESSURE AND RELATIVELY DRY AIR WILL COVER CENTRAL AND SOUTHEASTERN PENNSYLVANIA THIS MORNING. A COLD FRONT WILL PUSH SOUTHEAST ACROSS THE STATE THIS AFTERNOON AND EVENING. A SURGE OF COOLER...DRIER AIR AND SHARPENING OF THE UPPER TROUGH WILL PUSH A STRONGER COLD FRONT ACROSS THE COMMONWEALTH WEDNESDAY. COMFORTABLE HUMIDITY AND NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES WILL FOLLOW FOR LATE WEDNESDAY INTO THIS UPCOMING WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... SURFACE HIGH PRESSURE RIDGE STRETCHED SW TO NE ACROSS THE CWA WILL MAINTAIN CLEAR SKIES AND NEARLY CALM AIR FOR THE REST OF THE OVERNIGHT HOURS. THE CURRENT TIGHT...ZERO - 3 DEG F TEMP/DEWPOINT SPREAD AND AN AIR TO RIVER/STREAM TEMP DIFF OF AROUND 20F WILL LEAD TO PATCHY VALLEY FOG FOR SEVERAL HOURS LEADING UP TO...AND SHORTLY AFTER SUNRISE. VSBYS IN THE DEEPEST/COOLEST VALLEYS OF NRN PENN COULD DIP BRIEFLY BELOW 1/4SM THROUGH 12Z. LOW TEMPS THIS MORNING WILL RANGE FROM THE MID 50S IN THE COOLER NORTHERN AND WESTERN MTN VALLEYS...TO THE LOWER 60S IN THE SOUTHEAST METRO AREAS. QUASI-STNRY/RELATIVELY WEAK SFC FRONT EXTENDED FROM GRAND RAPIDS MICHIGAN...TO NEAR THE NORTH SHORE OF LAKE ERIE AT 08Z. ABUNDANT SUNSHINE WILL OCCUR THIS MORNING ACROSS THE LAUREL HIGHLANDS...CENTRAL MTNS...LYCOMING VALLEY AND NCENT MTNS BEFORE CLOUDS AND SCATTERED SHRA/TSRA ENCROACH FROM THE NW THIS AFTERNOON. THE LOWER SUSQ VALLEY SHOULD BASK IN MOSTLY SUNNY CONDITIONS WITH RELATIVELY COMFORTABLE HUMIDITY...THANKS TO THE SFC RIDGE AND NEAR TO SLIGHTLY BELOW NORMAL PWAT LINGERING THERE UNTIL 00Z WED. THE LATEST HRRR AND WRF ARW WERE BLENDED WITH THE 03Z SREF TO PAINT TIMING AND AREAL COVERAGE DETAILS INTO OUR POP AND WEATHER GRID DATABASE FOR THE ANTICIPATED SHOWERS AND SCATTERED TSRA THAT WILL IMPACT MAINLY THE NW HALF OF THE CWA DURING THE MIDDAY AND AFTERNOON HOURS TODAY. THE FRONTAL BOUNDARY WILL GRADUALLY WEAKEN AND SLOW AS IT EDGES TWD THE LAURELS AND LOWER SUSQ VALLEY TONIGHT...WITH ISOLATED TO WIDELY SCATTERED TSRA DRIFTING INTO THAT REGION LATER THIS EVENING. MU CAPES WILL INCREASE TO BETWEEN 800-1200 J/KG IN MOST PLACES BETWEEN 16-20Z...WITH A POCKET OF 1500 J/KG CAPE PRECEDING THE AREA OF MOST NUMEROUS SHRA/TSRA ACROSS THE NW AND NCENT MTNS LATE THIS AFTERNOON AND EARLY THIS EVENING. BASIN AVERAGE RAINFALL ENDING AT 00Z WED RANGE FROM ONE-TENTH...TO ONE-QUARTER OF AN INCH ACROSS THE NRN MTNS...TO JUST A FEW HUNDREDTHS AT BEST IN THE FAR SE. CONSENSUS BLEND OF ALL MODEL GUIDANCE YIELDS A HIGH TEMP IN THE MID TO UPPER 70S ACROSS THE NRN MTNS AND LAUREL HIGHLANDS...AND MID TO UPPER 80S THROUGHOUT THE VALLEYS OF CENTRAL AND SERN PENN. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... THE SCATTERED SHRA/TSRA LATE THIS AFTERNOON/EVENING ASSOCIATED WITH A WEAK COLD FRONT /AND PRE-FRONTAL TROUGH/ SHOULD DECREASE IN CVRG TONIGHT INTO EARLY WED WITH THE LOSS OF DAYTIME HEATING/INSTABILITY. CONCERNED THAT THE APPROACH OF A STRONG /90 KT/ 300 MB JET AND INCREASING DEEP LAYER UVVEL/STRONG PVA ASSOCIATED WITH THE THERMALLY INDIRECT TRANSVERSE CIRCULATION OF ITS LEFT EXIT REGION WILL SPARK A SEVERAL TO 6-HOUR PERIOD OF MORE NUMEROUS SHOWERS AND TSRA PRECEDING A SECONDARY CFRONT VERY EARLY WED ACROSS THE FAR WEST...AND DURING THE MID MORNING THROUGH MID AFTERNOON HOURS ACROSS THE CENTRAL AND SE ZONES. THE POTENTIAL FEW ROUNDS OF SHOWERS AND TSRA ALONG AND AHEAD OF THIS SECONDARY CFRONT SHOULD BE THE LAST DECENT OPPORTUNITY FOR RAINFALL HERE IN CENTRAL PA FOR AT LEAST 2-3 DAYS. 0-3 KM BULK SHEAR DOES HOWEVER INCREASED TO 25-30 KTS FROM THE WEST TO SOUTHWEST WEDNESDAY...WITH 0-6KM BULK SHEAR OF 40-45 KTS ACROSS NRN PENN IN THE MORNING...AND A RIBBON OF 50-60 KT SHEAR ACRS SOUTHERN PENN LATE WED AFTERNOON. HOWEVER... THE DY2 SPC CONVECTIVE OUTLOOK CONTINUES TO INDICATE ONLY FOR GENERAL THUNDER...WITH THE STG-SVR STORM THREAT LIMITED BY THE APPARENT LACK OF DEEP LYR MSTR/AVG PWS AND CAPE. WOULDN/T BE SURPRISED TO SEE THIS INCREASED TO A SEE TEXT /OR EVEN A COMPACT SLIGHT RISK AREA ACROSS PENN/ WITH LATER UPDATES. STRONG SUBSIDENCE BENEATH THE LEFT ENTRANCE REGION OF THE JET WILL LEAD TO CLEARING AND A RELATIVE MIN OF PRECIP ACROSS THE NRN THIRD TO HALF OF THE STATE AFTER 21Z WED...WHILE ISOLATED TO SCATTERED SHRA/TSRA LINGER ACROSS THE SOUTH. LOW TEMPS TONIGHT UNDER A FAIR AMOUNT OF CLOUD COVER /50-70 PERCENT/ WILL BE IN THE MID 50S TO MID 60S...WITH HIGH TEMPS WEDNESDAY VARYING FROM THE LOWER 70S ACROSS THE NRN MTNS...TO THE LOWER 80S IN THE SE. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... LG SCALE FORCING AND COOLER AIR ALOFT/STEEP MID-LVL LAPSE RATES TIED TO PASSAGE OF UPPER LEVEL TROUGH AXIS MAY PROVIDE ENOUGH LIFT TO GENERATE ISOLD...INSTABILITY TYPE SHOWERS ON THU AFTN. OTHERWISE ANTICIPATE A DRY PERIOD THROUGH THE UPCOMING WEEKEND AND INTO EARLY NEXT WEEK...WITH STRING OF PLEASANT DAYS/COMFORTABLE NIGHTS AS AREA REMAINS UNDER THE INFLUENCE OF SFC HIGH PRES MIGRATING S/SEWD FROM THE UPPER GRT LKS. TEMPS WILL START OUT BELOW AVG BEHIND THE DEPARTING TROUGH AXIS BUT SHOULD MODERATE AS HEIGHTS REBOUND BY 10/11 AUG. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... THE AREAS OF FOG THIS MORNING ALREADY SHOWING SIGNS OF IMPROVEMENT BY 12Z...WITH A RETURN TO VFR FOR ALL TERMINALS BY 13-14Z. FOG MAY PERSIST THE LONGEST AT KIPT WITH THICKEST FOG SETTLED IN THE WIDE RIVER VALLEY THERE. FOR TODAY...CLOUDS WILL REMAIN FEW TO SCATTERED IN THE SE HALF OF CWA...BUT A WEAK FRONTAL SYSTEM SLIDING INTO THE NW WILL BRING LOCAL MVFR CONDITIONS IN SCATTERED TO NUMEROUS MID/LATE AFTERNOON SHOWERS/ISO TSTMS AROUND KBFD. ISOLATED CONVECTION POSS FROM KJST-KUNV-KIPT...BUT POPS TOO LOW TO MENTION IN TAFS. WINDS WILL REMAIN LIGHT. SCT MVFR RESTRICTIONS POSS AGAIN TONIGHT ALONG WITH LINGERING CHANCE FOR SHOWERS /MAINLY ACROSS THE NORTHWEST/. SCT SHOWERS AND TSTMS RETURN AREAWIDE FOR WED. OUTLOOK... TUE...SCATTERED SHRA/TSRA WITH APPROACHING COLD FRONT...MAINLY NW. WED...SCATTERED SHRA/TSRA. THU-SAT...MAINLY VFR. PATCHY FOG POSSIBLE EARLY. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...LAMBERT LONG TERM...LAMBERT/STEINBUGL AVIATION...RXR
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
941 AM CDT TUE AUG 5 2014 .UPDATE... AREA OF STORMS EXTENDS FROM SOUTHERN IL SW TOWARD THE BOOTHEEL. THIS ACTIVITY IS WEAKENING AND IS NOT EXPECTED TO REACH THE MID STATE. HRRR FURTHER CONCURS WITH THIS SOLUTION SO OTHER THAN SOME INCREASED PARTIAL CLOUDINESS FOR TODAY...CONDITIONS SHOULD REMAIN DRY. OTW...SFC RIDGE STRETCHES FROM THE MID STATE NE TO PA. INSTABILITY CHARTS REVEAL THAT NOT MUCH OF ANY CAPE RETURN IS EXPECTED UNTIL TOMORROW AND THURSDAY. THEREFORE...WITH THE DRY STABLE CONDITIONS IN PLACE...NO POPS WILL BE ADDED TO TODAY`S FCST AT THIS TIME. TEMPS STILL EXPECTED TO REACH THE LOWER 90S FOR MANY AREAS. CURRENT TEMPS ARE IN THE MID TO UPPER 70S AND THIS IS IN LINE WITH THE LATEST NUMERICAL GUIDANCE. SO...ONLY CHANGE TO THE FCST WILL BE A LITTLE ADDED CLOUD COVER TO THE GRIDS. UPDATES WILL BE SENT OUT SHORTLY. && .PREV DISCUSSION... /ISSUED 601 AM CDT TUE AUG 5 2014/ UPDATE...ADDED AVIATION SECTION FOR 12Z TAF`S. AVIATION...BNA/CKV/CSV...SURFACE HIGH PRESSURE IS CURRENTLY CENTERED JUST EAST OF NASHVILLE, WITH A DRY AIR MASS IN PLACE OVER TENNESSEE AND GENERALLY LIGHT WINDS EXPECTED THE NEXT 24 HRS. WITH THE EXCEPTION OF MORNING RADIATION FOG AT CSV THROUGH 13Z, LOOK FOR VFR WX ACROSS MIDDLE TENNESSEE THROUGH THE TAF PERIOD. PREV DISCUSSION... /ISSUED 339 AM CDT TUE AUG 5 2014/ SHORT TERM...A RIDGE OF SURFACE HIGH PRESSURE, EXTENDING FROM THE VIRGINIAS ACROSS TENNESSEE AND INTO OKLAHOMA, WAS KEEPING SKIES CLEAR OVER THE MID STATE EARLY THIS MORNING. AT 2AM, TEMPERATURES WERE MAINLY IN THE LOWER AND MIDDLE 60S. ATMOSPHERE OVER THE MID STATE SHOULD REMAIN DRY ENOUGH TODAY TO KEEP US LOCKED INTO OUR CURRENT RAIN-FREE PATTERN. WITH MAXIMUM PERCENT SUNSHINE EXPECTED, BELIEVE WE WILL SEE TEMPERATURES SURGE TO THE SAME LEVELS AS YESTERDAY. CSV MAY EVEN BREAK THEIR 3-DAY STREAK OF MAXING OUT AT 83 DEGREES, AND NUDGE ON UP TO 84. YARDS AND GARDENS OVER MANY AREAS ARE NEEDING RAIN PRETTY BADLY AND, FORTUNATELY, WE HAVE REASON TO BE HOPEFUL FOR A GRADUAL CHANGE IN THE WEATHER PATTERN AS WE HEAD INTO THE MIDDLE AND LATTER PART OF THE WEEK. IF WE LOOK TO THE NORTHWEST THIS MORNING, UP OVER EAST- CENTRAL MISSOURI, WE SEE NOCTURNAL TSTMS IN PROGRESS, AND A HINT OF THE CHANGES THAT WILL BE COMING OUR WAY. LOOK FOR EASTERN MISSOURI TO BE A GOOD BREEDING GROUND FOR THUNDERSTORMS OVER THE NEXT 3 TO 5 DAYS, WITH THUNDERSTORMS EVENTUALLY PROPAGATING INTO OUR NECK OF THE WOODS. AS INTERMITTENT SHORTWAVES DROP SOUTHEASTWARD IN NORTHWEST FLOW, AND KICK OFF THUNDERSTORMS AND OUTFLOW BOUNDARIES, AND AS A LOW LEVEL COL CONVERGENCE BOUNDARY DEVELOPS OUT OF MISSOURI INTO WESTERN MIDDLE TN, WE WILL SEE SHOWERS AND STORMS BECOMING INCREASINGLY LIKELY HERE INT EH MID-STATE. UNFORTUNATELY, THE STORMS OVER EASTERN MISSOURI THIS MORNING WON`T DO US ANY GOOD, SINCE THEY SHOULD CONTINUE DROPPING MORE SOUTHWARD THAT EASTWARD. HOWEVER, THAT WILL CHANGE LATER TODAY AND TOMORROW. BY THIS AFTERNOON, EXPECT BEST CAPE TO BE OVER EASTERN MISSOURI AND SOUTHERN ILLINOIS, WITH TSTMS DEVELOPING IN THE AFTERNOON HEAT AND THEN SPILLING SOUTHEASTWARD TOWARD SOUTHWESTERN KY AND NORTHWESTERN MIDDLE TENNESSEE. AT LEAST A FEW ISOLATED RW/TRW COULD WORK THEIR WAY INTO NORTHWEST AND EXTREME N-CENTRAL PARTS OF OUR CWA LATE TONIGHT, ENHANCED BY A WEAK SFC CONVERGENCE BOUNDARY THAT IS FORECAST TO BE IN OUR NORTHWEST BY 12Z WED. AS WEAK SFC CONVERGENCE BOUNDARY MOVES EASTWARD AND DISSIPATES DURING THE DAY ON WEDNESDAY, CAPES WILL BE SUFFICIENT OVER SOUTHERN KENTUCKY AND MOST OF MIDDLE TENNESSEE TO ALLOW FOR ISOLATED TO SCATTERED CONVECTION (ESPECIALLY OVER NORTHERN AND EASTERN AREAS). MEANWHILE, EXPECT A SHORTWAVE TO FIRE MORE THUNDERSTORMS TO OUR NORTHWEST, BACK OVER SOUTHEASTERN MISSOURI. SOME OF THOSE STORMS ARE EXPECTED TO AFFECT OUR NORTHWESTERN COUNTIES WEDNESDAY NIGHT. HOWEVER, THE STORMS WILL BE WEAKENING AS THEY MOVE INTO OUR CWA AND MAY NOT PENETRATE OUR SOUTHERN AND EASTERN COUNTIES BEFORE DYING OUT. BY THURSDAY, CAPES OVER OUR AREA INCREASE TO 2500+ J/KG, AND ANOTHER SHORTWAVE SHOULD BE KICKING OFF THUNDERSTORMS OVER SOUTHEASTERN MISSOURI BY LATE MORNING. THESE STORMS WILL DROP SOUTHEASTWARD AND KICK OFF OUTFLOW BOUNDARIES WHICH WILL INTERACT WITH OUR HIGH CAPE ENVIRONMENT AND RESULT IN THE DEVELOPMENT OF SCATTERED THUNDERSTORMS OVER MIDDLE TENNESSEE. OUR HIGH TEMPS ON THU WILL BE LARGELY DETERMINED BY HOW FAST THUNDERSTORMS DEVELOP OVERHEAD. WITH BOTH NAM AND GFS GIVING RELATIVELY CONSISTENT TEMPS FOR THUR, AM HESITANT TO SHAVE TOO MUCH OFF GUIDANCE NUMBERS. THUS, WILL PROBABLY ONLY LOWER FORECAST HIGH TEMPS BY 1 OR 2 DEGS. MOS POPS AREN`T MUCH HELP WITH THIS TYPE OF NORTHWEST FLOW PATTERN, AND TEND TO UNDERESTIMATE RAIN CHANCE. THEREFORE, WILL GO QUITE A BIT ABOVE MOS POP NUMBERS OVER THE NEXT SEVERAL DAYS. RATHER THAN GO WITH THE 20-30% MOS POPS FOR THU, WILL GO MORE LIKE 30-50%. LONG TERM...AS WE HEAD INTO THE WEEKEND AND EARLY NEXT WEEK, BELIEVE GFS IS NOT PROPERLY ACCOUNTING FOR THE EFFECTS OF CLOUDS AND SHOWERS. IT SEEMS TO KEEP MAX TEMPS TOO WARM. ON THE OTHER HAND, DON`T REALLY BUY THE SIGNIFICANTLY COOLER SOLUTION OF THE ECMWF. THEREFORE, WILL GO WITH A GENERALLY PERSISTENT PATTERN, WITH HIGHS TOPPING OUT NEAR CLIMO NORMS. REGARDING POPS IN THE EXTENDED, BELIEVE THE MEX NUMBERS MAY BE A BIT HIGH AND WILL TREND MORE TOWARD CLIMO BY THE LATTER PERIODS. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 21
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
956 AM CDT TUE AUG 5 2014 .UPDATE... NEARLY OVERCAST CONDITIONS REMAIN ACROSS THE SOUTHWEST HALF OF THE FORECAST AREA THIS MORNING. LATEST SATELLITE TRENDS AND MODEL SOUNDINGS INDICATE THAT THIS CLOUD DECK SHOULD BREAK UP A BIT LATE MORNING INTO THE AFTERNOON...ALLOWING FOR SOME SUNSHINE. THIS SHOULD RESULT IN TEMPS WARMING TO FORECAST HIGHS. A COUPLE MODELS ARE SHOWING A FEW SHOWERS OR SPRINKLES MAINLY IN THE WEST THIS AFTERNOON. THERE WILL BE SOME INSTABILITY...BUT NOT SEEING MUCH A TRIGGER...SO WILL KEEP THE FORECAST DRY FOR NOW. && .AVIATION/18Z TAFS/... CONDITIONS HAVE RETURNED TO MAINLY VFR ACROSS THE NORTHEAST FORECAST AREA THIS MORNING. LOW CIGS REMAIN ACROSS THE SOUTHWEST...BUT IMPROVEMENT IS EXPECTED LATE MORNING INTO THE AFTERNOON AS THIS CLOUD DECK ERODES FROM THE NORTHEAST. ADDITIONALLY...DAYTIME MIXING SHOULD HELP TO BREAK UP THE CLOUDS SOME AND RAISE THE CLOUD BASES. COULD SEE SOME PATCHY FOG TONIGHT...BUT OTHERWISE EXPECT VFR CONDITIONS TONIGHT INTO WEDNESDAY AS HIGH PRESSURE SITS OVER THE GREAT LAKES. && .PREV DISCUSSION... /ISSUED 312 AM CDT TUE AUG 5 2014/ SHORT TERM... TODAY AND TONIGHT...FORECAST CONFIDENCE IS HIGH. THE MID/UPPER LEVEL TROUGH WILL EXIT THE LAKE MICHIGAN AREA AROUND SUNRISE THIS MORNING. THE 250 MB JET MAX BEHIND THE TROUGH INCREASES TO 100 KNOTS THIS AFTERNOON OVER WISCONSIN BEFORE MOVING INTO LOWER MICHIGAN EARLY WEDNESDAY MORNING. THIS PUTS SOUTHWEST WISCONSIN IN THE LEFT EXIT REGION OF THE JET. AS A RESULT UPPER DIVERGENCE INCREASES OVER MUCH OF SOUTH CENTRAL AND FAR SOUTHEAST WISCONSIN. THE MODERATE 700 MB UPWARD MOTION IS FARTHER SOUTH ACROSS IOWA AND NORTHWEST ILLINOIS LATE TONIGHT. AS A RESULT MOST MODELS KEEP THE PRECIPITATION JUST SOUTHWEST AND SOUTH OF THE FORECAST AREA. HOWEVER THE NAM DOES BRING SOME PRECIPITATION TO AREAS MAINLY SOUTHWEST OF MADISON. WILL INCLUDE A CHANCE OF SHOWERS LATE TONIGHT TO ACCOUNT FOR THIS POSSIBILITY. 850 MB MOISTURE REMAINS TODAY BEFORE DRYING FROM THE NORTHEAST TONIGHT EXCEPT FOR THE FAR SOUTHWEST. ZERO TO 1 KM MIXED LAYER CAPE REACHES 1000 JOULES/KG ALONG THE ILLINOIS BORDER WITH LESS THAN 200 JOULES/KG NEAR SHEBOYGAN. THEREFORE ISOLATED SHOWERS ARE NOT OUT OF THE QUESTION. HOWEVER THE HRRR IS DRY THROUGH 19Z WITH ONLY A FEW SHOWERS POSSIBLE ALONG THE LAKE BREEZE FRONT. THE 00Z HIGH RES WRF/ARW DOES BRING A FEW ISOLATED LIGHT SHOWERS. OTHERWISE THE MAIN PROBLEM IS FOG...WITH A FEW AREAS DENSE...DURING THE EARLY MORNING TODAY. THE FOG/STRATUS WILL DISSIPATE IN THE MID/LATE MORNING HOURS. TUESDAY NIGHT THROUGH FRIDAY...FORECAST CONFIDENCE HIGH. A LARGE UPPER LOW WILL SIT OVER JAMES BAY THROUGH SATURDAY. THE TROUGH WILL EXTEND ALL THE WAY DOWN ACROSS THE SOUTHEAST STATES. NORTHWEST FLOW WILL PREVAIL ACROSS SOUTHERN WI. WEAK SHORTWAVES ROTATING AROUND THE UPPER LOW AND STEEP LOW LEVEL LAPSE RATES WILL LEAD TO SCATTERED DIURNAL SHOWERS WITH A FEW RUMBLES OF THUNDER EACH DAY FROM LATE MORNING THROUGH EARLY EVENING. AFTERNOON CAPE VALUES WILL BE ON THE LOWER SIDE...AROUND 100 TO 300 J/KG... ON WEDNESDAY...THUS LOWER CHANCES FOR THUNDER. HIGHER VALUES OF 700-900 J/KG CAPE ARE EXPECTED FOR THU AND FRIDAY AFTERNOONS. THE MORE DISTINCT AND AGREED UPON BETWEEN MODELS SHORTWAVE TROUGH SHOULD SWING THROUGH SOUTHERN WI FRIDAY AFTERNOON/EVENING...THUS THE BEST DAY FOR MORE WIDESPREAD AND HEAVIER SHOWERS AND THUNDERSTORMS. 850MB TEMPS WILL BE AROUND 10C TO 12C AND 925MB TEMPS AROUND 19C THROUGHOUT THE WEEK. THIS TRANSLATES TO HIGHS IN THE UPPER 70S TO AROUND 80 AND LOWS IN THE 50S. LONG TERM... SATURDAY THROUGH MONDAY...FORECAST CONFIDENCE MEDIUM. THE UPPER TROUGH WILL BEGIN TO SHIFT EAST LATER SATURDAY THROUGH SUNDAY. SHOWERS ARE POSSIBLE ONCE AGAIN SATURDAY AFTERNOON...BUT LESS LIKELY ON SUNDAY AS DRY HIGH PRESSURE SLIDES ACROSS THE WESTERN GREAT LAKES. A SURFACE AND UPPER LOW PRESSURE TROUGH WILL LIKELY LINGER OVER NORTHERN WI SUNDAY NIGHT. MEANWHILE...SOUTHERLY FLOW ON THE BACK SIDE OF THE HIGH WILL ALLOW 850MB TEMPS TO INCREASE TO 14C AND 925MB TEMPS TO AROUND 22C BY MONDAY MORNING. EVENTUALLY...THAT SURFACE TROUGH WILL SLIDE DOWN THROUGH SOUTHERN WI TO BRING THE NEXT CHANCE FOR SHOWERS AND THUNDERSTORMS MONDAY AFTERNOON AND NIGHT. DRY AND COOL HIGH PRESSURE IS EXPECTED TO SET UP ONCE AGAIN EARLY NEXT WEEK. AVIATION/12Z TAFS/... SATURATED LOW LEVELS WILL BRING AREAS OF IFR/LIFR FOG/STRATUS. A FEW SPOTS WILL BE AROUND 1/4 MILE. THE FOG AND STRATUS WILL LIFT/DISSIPATE DURING THE MID/LATE MORNING. THEN MVFR CIGS BECOMING MAINLY VFR LATER THIS AFTERNOON. ISOLATED SHOWERS [POSSIBLE MAINLY THIS AFTERNOON. HIGH PRESSURE WILL BUILD OVER THE GREAT LAKES TONIGHT. SHOWERS POSSIBLE LATE TONIGHT SOUTHWEST OF MADISON ASSOCIATED WITH AN UPPER JET MAX. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ UPDATE...DDV TODAY/TONIGHT AND AVIATION...HENTZ WEDNESDAY THROUGH MONDAY...MRC
AREA FORECAST DISCUSSION
NWS TUCSON AZ
305 PM MST TUE AUG 5 2014 .SYNOPSIS...DRIER AIR WILL LIMIT THUNDERSTORMS TO MAINLY NEAR THE NEW MEXICO BORDER THROUGH THURSDAY. DEEPER MOISTURE WILL THEN RETURN FRIDAY AND CONTINUE INTO EARLY NEXT WEEK. THIS WILL PROVIDE A RETURN OF ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS. DAYTIME TEMPERATURES THIS WEEK WILL BE NEAR OR SLIGHTLY ABOVE NORMAL. && .DISCUSSION...ISOLATED THUNDERSTORMS OVER FAR NERN SONORA WITH PRECIP-FREE CONDITIONS ACROSS SE AZ AT THIS TIME. VISIBLE SATELLITE IMAGERY AND SURFACE OBSERVATIONS INDICATED MOSTLY CLEAR SKIES TO PARTLY CLOUDY SKIES...WITH THE BULK OF CUMULOFORM CLOUDS ACROSS ERN SECTIONS. HAVE MAINTAINED ISOLATED SHOWERS/TSTMS NEAR THE NEW MEXICO INTO EARLY THIS EVENING AS PER THE 05/20Z RUC HRRR SOLUTION. CLOUDS SHOULD THEN DISSIPATE AROUND OR SHORTLY AFTER SUNSET FOLLOWED BY CLEAR SKIES OR MOSTLY CLEAR SKIES LATER TONIGHT. DRY GENERALLY WLY FLOW ALOFT TO PREVAIL WED-THUR AS HIGH PRESSURE REMAINS CENTERED OVER NRN CHIHUAHUA AND A WEAK UPPER LEVEL TROUGH CONTINUES OVER THE GREAT BASIN REGION. VARIOUS 05/12Z NWP MODELS INDICATE THE POTENTIAL FOR LESS SHOWER/TSTM ACTIVITY WED VERSUS THIS AFTERNOON. ALTHOUGH INHERITED POPS WERE REDUCED SOMEWHAT...FOR NOW HAVE MAINTAINED ISOLATED COVERAGE OF SHOWERS/TSTMS MAINLY NEAR THE NEW MEXICO BORDER WED AFTERNOON/EVENING. SLIGHTLY GREATER COVERAGE OF SHOWERS/TSTMS SHOULD OCCUR THUR...WITH ISOLATED SHOWERS/TSTMS SHOULD GENERALLY OCCUR SE OF A HANNAGAN MEADOW-SAFFORD-SIERRA VISTA LINE. THEREAFTER...THERE WERE DIFFERENCES BETWEEN THE 05/12Z NAM/GFS/ECMWF REGARDING THE TIMING FOR DEEPER MOISTURE AND GREATER COVERAGE OF SHOWERS/TSTMS WILL RETURN TO SE AZ. IN ESSENCE...THE NAM FAVORED FRI AS A POTENTIAL SIGNIFICANT INCREASE IN COVERAGE OF SHOWERS/TSTMS...THE ECMWF FAVORED SAT...AND THIS VERSION OF THE GFS DELAYED THE ONSET OF MORE SUBSTANTIAL CONVECTIVE ACTIVITY UNTIL SUN. THE OFFICIAL FORECAST DEPICTS A GRADUAL DAILY INCREASE IN SHOWERS/ TSTMS FRI-SUN. THUS...SCATTERED MAINLY AFTERNOON/EVENING SHOWERS/TSTMS SHOULD RETURN TO THE AREA BY SUN. A FAIRLY DEEP GENERALLY SELY FLOW REGIME IS PROGGED TO OCCUR MON-TUE IN RESPONSE TO HIGH PRESSURE ALOFT CENTERED OVER NRN NEW MEXICO. THIS PATTERN IS EXPECTED TO YIELD THE DAILY CYCLE OF SCATTERED MAINLY AFTERNOON/EVENING SHOWERS/ TSTMS. ENOUGH MOISTURE APPEARS TO EXIST TO SUPPORT AT LEAST A SLIGHT CHANCE OF SHOWERS/TSTMS DURING THE OVERNIGHT/EARLY MORNING HOURS MON-TUE. HIGH TEMPS WED WILL BE NEARLY IDENTICAL TO TEMPS ACHIEVED THIS AFTERNOON. A VERY GRADUAL DAILY COOLING TREND WILL THEN OCCUR THUR- SAT FOLLOWED BY NO SIGNIFICANT CHANGE IN DAYTIME TEMPS SUN-TUE. && .AVIATION...VALID THRU 7/00Z. ISOLATED -TSRA/-SHRA NEAR THE FAR SE AZ/FAR SW NEW MEXICO BORDER EAST OF KDUG ENDING AROUND 06/03Z. ISOLATED -TSRA/-SHRA MAINLY NEAR THE NEW MEXICO BORDER AGAIN WEDNESDAY AFTERNOON. OTHERWISE...CLEAR SKIES WEST OF KTUS THRU WEDNESDAY AFTERNOON. KTUS VICINITY EASTWARD EXPECT A FEW-SCT CLOUDS WITH BASES GENERALLY AT 8-12K FT AGL EARLY THIS EVENING AND WEDNESDAY AFTERNOON. CLEAR SKIES OR MOSTLY CLEAR SKIES EAST OF KTUS LATE TONIGHT AND WEDNESDAY MORNING. SURFACE WINDS WILL BE MAINLY LESS THAN 10 KTS ALTHOUGH A FEW GUSTS TO AROUND 20 KTS MAY OCCUR WEDNESDAY AFTERNOON. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...DRY CONDITIONS WILL PREVAIL THROUGH THURSDAY EXCEPT FOR A SLIGHT CHANCE OF AFTERNOON THUNDERSTORMS NEAR THE NEW MEXICO BORDER. EXPECT ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS TO RETURN ON FRIDAY AND CONTINUE INTO EARLY NEXT WEEK AS DEEPER MOISTURE RETURNS TO THE AREA. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON FRANCIS
AREA FORECAST DISCUSSION
NWS TUCSON AZ
925 AM MST TUE AUG 5 2014 .SYNOPSIS...DRIER AIR WILL LIMIT THUNDERSTORMS TO MAINLY NEAR THE NEW MEXICO BORDER THROUGH MIDWEEK. DEEPER MOISTURE WILL THEN RETURN FRIDAY AND CONTINUE INTO EARLY NEXT WEEK. THIS WILL PROVIDE A RETURN OF ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS. DAYTIME TEMPERATURES THIS WEEK WILL BE NEAR OR SLIGHTLY ABOVE NORMAL. && .DISCUSSION...CLEAR SKIES PREVAIL ACROSS SE AZ AT THIS TIME EXCEPT FOR A FEW CUMULOFORM CLOUDS ACROSS THE WHITE MOUNTAINS AND THE CHIRICAHUA MOUNTAINS IN ERN COCHISE COUNTY. DEWPOINTS AT LOWER ELEVATIONS VALID 16Z RANGED FROM THE UPPER 40S-LOWER 60S F. THESE TEMPS WERE GENERALLY 5-15 DEGS F LOWER VERSUS 24 HOURS AGO. SURFACE TEMPS VALID 16Z WERE VIRTUALLY UNCHANGED VERSUS THIS TIME MON. 05/12Z KTWC SOUNDING TOTAL PRECIP WATER WAS 0.78 INCH...AND THIS VALUE WAS NEARLY 2 STANDARD DEVIATIONS BELOW NORMAL. 05/12Z UPPER AIR PLOTS INDICATED 592 DM HIGH PRESSURE CENTERED OVER WEST CENTRAL TEXAS AND A WEAK TROUGH WAS OVER THE GREAT BASIN. LIGHT GENERALLY WLY FLOW PREVAILED OVER SE AZ. 05/12Z UNIV OF AZ WRF-NAM AND 05/14Z RUC HRRR WERE SIMILAR WITH DEPICTING A FEW PRECIP ECHOES TO OCCUR THIS AFTERNOON NEAR THE NEW MEXICO BORDER. MORE SPECIFICALLY...THE FAVORED AREAS FOR ISOLATED SHOWERS/TSTMS TO OCCUR APPEARS TO BE ACROSS THE WHITE MOUNTAINS AND THE CHIRICAHUA MOUNTAINS IN ERN COCHISE COUNTY. BELIEVE ANY SHOWERS/ TSTMS THAT DO OCCUR WILL DISSIPATE AROUND OR SHORTLY AFTER SUNSET. GIVEN THE VERY DRY REGIME...ANY PRECIP AMOUNTS WILL BE QUITE LIGHT. CLEAR SKIES OR MOSTLY CLEAR SKIES WILL PREVAIL LATER TONIGHT. WILL MAKE SOME MINOR ADJUSTMENTS TO THE GRIDDED DATA POP/WEATHER FIELDS TO REFLECT THE ABOVE SCENARIO. OTHERWISE...PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL. && .AVIATION...VALID THRU 6/18Z. ISOLATED -TSRA/-SHRA MAY OCCUR NEAR THE NEW MEXICO BORDER...AND ESPECIALLY ACROSS THE WHITE MOUNTAINS NE OF KSAD THIS AFTERNOON AND EARLY THIS EVENING. OTHERWISE...EXPECT A FEW TO SCATTERED CUMULUS CLOUDS WITH BASES GENERALLY AT 8-12K FT AGL THIS AFTERNOON AND EARLY THIS EVENING. CLEAR SKIES WEST OF KTUS TONIGHT WITH A FEW TO SCATTERED CLOUDS ABOVE 10K FT AGL EAST OF KTUS. SURFACE WINDS WILL BE MAINLY LESS THAN 10 KTS ALTHOUGH A FEW GUSTS TO AROUND 20 KTS MAY OCCUR THIS AFTERNOON. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...DRY CONDITIONS WILL PREVAIL THROUGH THURSDAY EXCEPT FOR A SLIGHT CHANCE OF AFTERNOON THUNDERSTORMS NEAR THE NEW MEXICO BORDER. INCREASING MOISTURE STARTING FRIDAY AND CONTINUING INTO EARLY NEXT WEEK WILL PROVIDE A RETURN OF ISOLATED TO SCATTERED THUNDERSTORMS. THE BEST CHANCES FOR RAINFALL WILL BE DURING THE AFTERNOON AND EVENING HOURS. && .PREV DISCUSSION.../ISSUED AT 214 AM MST/...BY THURSDAY THE MODELS INDICATE THAT HIGH PRESSURE WILL BE OVER NORTHEAST MEXICO AND NORTHWARD INTO NEW MEXICO...WITH A TROUGH OVER THE GREAT BASIN AND INTO SOUTH CENTRAL CALIFORNIA. THIS WILL RESULT IN MORE SOUTHERLY WINDS ACROSS THE REGION THAT WILL TAP INTO SOME OF THE HIGHER MOISTURE TO OUR SOUTH...RESULTING IN A MODEST INCREASE IN RAIN CHANCES...MAINLY FROM TUCSON SOUTH AND EASTWARD. BY LATE THIS WEEK AND INTO THE WEEKEND...THE HIGH SHIFTS TO THE NORTH AND EAST EXTENDING FROM SOUTHERN TEXAS INTO NORTHERN NEW MEXICO WITH MORE OF A SOUTHEASTERLY FETCH. IN ADDITION... DISTURBANCES MOVING WESTWARD UNDER THE HIGH WILL HELP TO ENHANCE ACTIVITY. SO...MADE ONLY MINOR ADJUSTMENTS TO THE POP FORECAST IN THE EXTENDED FORECAST...WITH BASICALLY SCATTERED TYPE POPS IN THE FORECAST FOR MOST AREAS. HIGH TEMPERATURES WILL GENERALLY BE 3 TO 5 DEGS ABOVE NORMAL TODAY THROUGH THURSDAY...THEN NEAR NORMAL FOR FRIDAY THROUGH THE WEEKEND AND BACK TO AROUND 2 TO 4 DEGS ABOVE NORMAL FOR MONDAY. LOW TEMPS WILL BE NEAR OR SLIGHTLY ABOVE NORMAL WEDNESDAY THROUGH SATURDAY MORNINGS...THEN 2 TO 3 DEGS ABOVE NORMAL SUNDAY AND MONDAY. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON FRANCIS PREVIOUS DISCUSSION...MOLLERE
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
330 PM MDT TUE AUG 5 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 328 PM MDT TUE AUG 5 2014 NUMEROUS SHOWERS AND THUNDERSTORMS OVER THE MOUNTAINS ARE PUSHING NORTHEAST. SOME CELLS HAVE BEEN PRODUCING BETWEEN A THIRD TO A HALF OF AN INCH OF RAIN IN ABOUT 15-30 MINUTES...WITH STRONGER CELLS PRODUCING OVER THREE-QUARTERS OF AN INCH. A CURRENT PW VALUES HOVERING ABOUT AN INCH RIGHT NOW AND ARE EXPECTED TO START LOWERING AS DRIER AIR...EVIDENT ON WATER VAPOR SATELLITE...MOVES IN FROM THE SOUTHWEST. DEWPOINTS IN THE UPPER 40S OVER THE MOUNTAINS WILL BE PUSHING EAST WHERE DEWPOINTS OVER THE EASTERN PLAINS ARE IN THE UPPER 50S TO LOWER 60S. MOVEMENT ON THESE STORMS ARE AROUND 15 KTS...SO FLOOD THREAT AT THIS POINT IS THERE IN SOME SPOTS...BUT OVERALL AREA WIDE IS LOW. TRAINING STORMS COULD CREATE A PROBLEM. BIGGEST AREA OF CONCERN IS DOWN SOUTH ALONG THE PALMER DIVIDE AREA AND SOUTHERN FOOTHILLS WITH ANOTHER THREAT UP OVER LARIMER COUNTY AS CONVECTION IS FORMING A TRAINING LINE. GUSTY OUTFLOW WINDS FROM THESE STORMS TONIGHT WILL ALSO BE ANOTHER THREAT...ESPECIALLY AS THE DRIER AIR ALOFT MOVES IN. THERE IS SLIGHTLY MORE INSTABILITY OUT EAST TOWARDS THE NEBRASKA BORDER...WHERE STORMS OUT HERE MAY BE ABLE TO STRENGTHEN ENOUGH FOR SMALL HAIL...OTHERWISE THE SEVERE STRENGTH STORM THREAT IS LOW. AS THE SHORTWAVE CONTINUES TO PUSH EAST...QG VERTICAL VELOCITY WILL SWITCH FROM LIGHT UPWARD TO LIGHT DOWNWARD. THIS COMBINED WITH THE LOSS OF DAYTIME HEATING WILL ALLOW CONVECTION TO DECREASE THIS EVENING AND SHOULD BE DIMINISHED BEFORE MIDNIGHT. THERE ARE HINTS FROM THE HIRES RAP MODEL THAT OUTFLOW FROM STORMS IN CENTRAL NEBRASKA MAY PUSH BACK INTO COLORADO TONIGHT TO KEEP CONVECTION GOING....AT THIS POINT DO NOT THINK THIS WILL HAPPEN WITH CURRENT STRENGTH AND MOTION OF THE STORMS OUT THERE. UPPER RIDGING WILL MOVE OVERHEAD TOMORROW WITH DRIER PW VALUES EXPECTED. A WEAK COOL FRONT WILL SLIDE SOUTH IN THE EARLY AFTERNOON TO KEEP MOST OF THE PLAINS STABLE FOR MUCH OF THE DAY. WITH MORE SUNLIGHT EXPECTED TOMORROW HOWEVER WILL LEAD TO NEARLY THE SAME OR SLIGHTLY WARMER TEMPERATURES COMPARED TO TODAY. LESS CONVECTION IS EXPECTED OVER THE MOUNTAINS...BUT WILL STILL LIKELY SEE ISOLATED TO SCATTERED ACTIVITY. ONCE THE FRONT PUSHES IN AND SOME UPSLOPE FLOW ESTABLISHES ITSELF...THERE MAY BE ENOUGH PUSH FOR SOME ISOLATED ACTIVITY ALONG THE NORTHERN FOOTHILLS AND ADJACENT PLAINS. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 328 PM MDT TUE AUG 5 2014 SOME THUNDERSTORMS POSSIBLE ACROSS THE AREA WEDNESDAY EVENING... MAINLY OVER THE FAR NORTHEAST PLAINS AS TAIL END OF MID LEVEL SHORTWAVE MOVES ACROSS NORTHEAST COLORADO. STORMS COULD PRODUCE BRIEF HEAVY RAIN FAR EASTERN PLAINS. THE ACTIVITY SHOULD END AROUND MIDNIGHT AS SUBSIDENCE BEHIND THE PASSING WAVE MOVES OVER THE AREA. BOUNDARY LAYER WIND AND RH PROGS SUGGEST THE POTENTIAL FOR LOW CLOUDS ACROSS MUCH OF THE PLAINS...MAINLY EAST OF A GREELEY TO DENVER LINE OVERNIGHT. AT THIS TIME...THE THREAT FOR ANY FOG APPEARS LOW AND WILL LEAVE OUT OF THE GRIDS. ON THURSDAY... THE UPPER RIDGE OVER COLORADO IS EXPECTED TO FLATTEN A BIT AS A SHORTWAVE MOVES ACROSS WYOMING. CENTER OF THE HIGH TO MOVE TOWARDS THE TEXAS AND OKLAHOMA PANHANDLES. EASTERLY LOW LEVEL FLOW ACROSS PLAINS TO PROVIDE UPSLOPE IN AND NEAR THE FOOTHILLS. IN ADDITION... TAIL END OF THE WAVE LOOKS TO CLIP THE NORTHEAST CORNER. THUS... SHOULD SEE SOME STORMS DEVELOP DURING THE AFTERNOON WHICH WILL CONTINUE INTO THE EVENING. BEST CHANCE FOR STORMS TO BE NORTHEAST OF GREELEY AND DENVER WHERE THE BETTER LOW LEVEL MOISTURE WILL BE LOCATED. BRIEF HEAVY RAIN POSSIBLE WITH SOME OF THE STORMS OVER THE FAR NORTHEAST CORNER. TEMPERATURES LOOK TO BE AROUND AVERAGE MOST AREAS. LATEST MODELS SHOWING THE DEVELOPMENT OF SOME SORT OF MCS OVER THE FAR EASTERN PLAINS LATE IN THE EVENING...PUSHING INTO KANSAS OVERNIGHT. SOME LINGERING STORMS POSSIBLE OVER THE FAR EASTERN PLAINS BEFORE THIS SYSTEM MOVES AWAY FROM THE AREA. FOR FRIDAY...THERE MAY BE A PUSH OF LOW LEVEL MOISTURE BACK ACROSS THE PLAINS EARLY IN THE MORNING WITH THE POTENTIAL FOR THE DEVELOPMENT OF LOW CLOUDS AGAIN. OTHERWISE... MODELS INDICATE ANOTHER WEAK MID LEVEL SHORTWAVE CLIPPING THE FAR NORTHEAST CORNER DURING THE AFTERNOON WHICH COULD GENERATE ANOTHER ROUND OF AFTERNOON AND EVENING THUNDERSTORMS. SOME STORMS POSSIBLE FURTHER WEST... MAINLY ALONG THE FOOTHILLS WHERE LOW LEVEL SOUTHEAST FLOW WILL BE IN PLACE. A FEW STORMS COULD LINGER AFTER MIDNIGHT ACROSS THE FAR PLAINS. ON SATURDAY...MODELS SHOW ELONGATED UPPER HIGH OVER COLORADO WITH THE CENTER OVER NORTHEAST TEXAS. APPEARS A BATCH OF MONSOONAL MOISTURE LOOKS TO MOVE ACROSS THE AREA DURING THE AFTERNOON AND EVENING. THIS MAY RESULT IN A BETTER CHANCE FOR THUNDERSTORMS MOST LOCATIONS. TEMPERATURES BOTH FRIDAY AND SATURDAY TO HOVER AROUND AVERAGE. FOR THE LATER DAYS...SUNDAY THROUGH TUESDAY. UPPER LEVEL RIDGE TO REMAIN OVER COLORADO THROUGH THE PERIOD. THERE APPEARS TO BE SOME DECREASE IN THE MONSOONAL MOISTURE THOUGH ENOUGH FOR SOME CHANCE OF AFTERNOON AND EVENING THUNDERSTORMS. BEST CHANCE TO BE ACROSS THE MOUNTAINS. BY TUESDAY...BOTH ECMWF AND GFS SHOW THE UPPER RIDGE FLATTENING AS A SHORTWAVE MOVES ACROSS WYOMING. FLOW ALOFT TO BECOME MORE WESTERLY...WITH MOST OF THE MONSOONAL MOISTURE BEING SHUNTED SOUTH OF THE AREA. WILL KEEP A SLIGHT CHANCE OF STORMS GOING MOST LOCATIONS. TEMPERATURES LOOK TO NEAR OR SLIGHTLY BELOW AVERAGE. && .AVIATION...(FOR THE TAFS THROUGH 00Z WEDNESDAY LATE AFTERNOON) ISSUED AT 328 PM MDT TUE AUG 5 2014 VFR CONDITIONS EXPECTED FOR THE NEXT 36 HOURS. CONVECTION OVER THE FOOTHILLS AND PALMER DIVIDE WILL CONTINUE MOVING EAST- NORTHEAST OVER THE PLAINS WITH TSTORMS AFFECTING THE AREA AIRPORTS THROUGH ABOUT 24Z. THESE STORMS WILL HAVE A CHANCE OF PRODUCING VARIABLE WINDS GUSTING TO 30 KNOTS...AND JUST A SLIGHT CHANCE OF NEEDING INSTRUMENT APPROACHES TO KDEN FOR A SHORT TIME. CLEARING SHOULD OCCUR QUICKLY AFTER 00Z. LIGHT NORTHERLY WINDS SHOULD RETURN TO DRAINAGE WINDS TONIGHT. LITTLE TO NO CONVECTION EXPECTED TOMORROW. A FRONT WILL PUSH THROUGH AFTER 18Z TO TURN WINDS TO THE NORTHEAST...BUT NO THUNDERSTORMS ARE EXPECTED OVER THE AREA AIRPORTS AT THIS TIME. && .HYDROLOGY... ISSUED AT 328 PM MDT TUE AUG 5 2014 BRIEF HEAVY RAIN...UP TO HALF AN INCH IN 15 MINUTES...WILL ACCOMPANY SOME OF THE STRONGER STORMS TODAY. THERE COULD BE SOME AREAS THAT MAY SEE UP TO AN INCH AS TRAINING OF STORMS OCCUR. OVERALL STORM MOTION SHOULD BE ENOUGH TO KEEP THE THREAT OF FLASH FLOODING LOW...EXCEPT IN THE CASE OF TRAINING...ESPECIALLY OVER A BURN SCAR OR STEEP TERRAIN. STORMS WILL BE DECREASING THROUGH MID EVENING AND SHOULD BE DONE BY BEFORE MIDNIGHT. HEAVY RAIN CHANCES ARE LOW THROUGH THE EXTENDED PERIOD. SCATTERED T-STORMS ACROSS THE NORTHEAST CORNER OF THE STATE LATE THURSDAY AND FRIDAY HAVE THE POTENTIAL TO PRODUCE LOCALLY HEAVY RAINFALL. HOWEVER THE THREAT OF FLOODING APPEARS LOW. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...KRIEDERMAN LONG TERM...D-L AVIATION...KRIEDERMAN HYDROLOGY...KRIEDERMAN
AREA FORECAST DISCUSSION
NWS ALBANY NY
500 PM EDT TUE AUG 5 2014 .SYNOPSIS... A COLD FRONT WILL CROSS THE REGION TONIGHT. A SECONDARY COLD FRONT WILL CROSS THE REGION ON THURSDAY. HIGH PRESSURE WILL SETTLED IN FRIDAY THROUGH THE WEEKEND. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... AS OF 500 PM EDT...WIDELY SCATTERED THUNDERSTORMS WERE ACROSS OUR REGION...MOST NUMEROUS ACROSS WASHINGTON COUNTY WHERE EARLIER A SEVERE THUNDERSTORM WARNING WAS ISSUED. THIS STORM PRODUCED WIND DAMAGE NEAR HEWITT`S LANDING. MEANWHILE...A CLUSTER OF SHOWERS AND THUNDERSTORMS OVER WESTERN AND CENTRAL NEW YORK...ASSOCIATED WITH A COLD FRONT (ENHANCING SURFACE CONVERGENCE) AND THE EXIT REGION OF THE UPPER LEVEL JET (ENHANCING DIVERGENCE ALOFT) ...CONTINUE TO MOVE STEADILY EAST. IT LOOKS AS IF THIS AREA OF RAIN MIGHT STAY JUST FROM THE CAPITAL REGION SOUTHWARD. THE LATEST HRRR HAS TRENDED A LITTLE SLOWER AND SOUTH WITH THE HEAVIEST RAINFALL...MAINLY JUST SOUTH OF THE CAPITAL REGION THIS EVENING. WILL CONTINUE CHANCE POPS THROUGH ALL OF THE EVENING...INCLUDING THUNDER. GIVEN INSTABILITY AROUND 2000 J/KG...LAPSE RATES OVER 6.0 C/KM...AND ALREADY HISTORY OF ONE DAMAGING WIND THUNDERSTORM AND SMALL HAIL...WE WENT AHEAD AND ADDED QUALIFIER TO THE THUNDERSTORMS THROUGH THIS EVENING..."MIGHT CONTAIN GUSTY WINDS AND SMALL HAIL." SO THROUGH EVENING...EXPECT SCATTERED SHOWERS AND THUNDERSTORMS (MEANING NOT EVERYONE WILL RECEIVE MEASURABLE RAINFALL...BUT SOME AREAS GET A GOOD SOAKING RAIN AND THUNDERSTORM ACTIVITY). IT WILL REMAIN QUITE WARM AND SOMEWHAT HUMID WITH TEMPERATURES IN THE MID TO UPPER 80S...COOLING TO THE 70S LATER THIS EVENING...ESPECIALLY WHERE RAINFALL COOLS THE COLUMN. THE WIND WILL BE VARIABLE SHIFTING TO NORTHWESTERLY LATER TONIGHT BEHIND THE FRONT GENERALLY 10 MPH OR LESS. OVERNIGHT...THE FRONT WILL LIKELY STILL BE SOMEWHERE TO THE SOUTH OF THE CAPITAL REGION. SHOWERS AND THUNDERSTORMS WILL DIMINISH ALL TOGETHER AS UPPER LEVEL FORCING (THE JET EXIT REGION) LIFTS NORTH AND INSTABILITY DISSIPATES. THE SKY WILL PARTIALLY CLEAR. THIS MIGHT ALLOW FOR SOME FOG TO FORM. HOWEVER...THERE MIGHT BE JUST ENOUGH OF A BREEZE TO PREVENT THIS. FOR NOW...DECIDED NOT INCLUDE ANY FOG TONIGHT PENDING HOW MUCH RAINFALLS AND MAKES THE GROUND WET. OVERNIGHT LOWS WILL GENERALLY RANGED FROM THE MID 50S NORTHWEST AND LOWER 60S CAPITAL REGION SOUTHWARD. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/... SOMEWHAT DRIER AND COOLER AIR WILL FILTER INTO THE REGION ON WEDNESDAY BEHIND THE COLD FRONT. HOWEVER...THE ACTUAL FRONT WILL LIKELY STILL BE JUST TO THE SOUTH OF THE CAPITAL REGION. THERE COULD BE A RENEWAL OF SHOWER AND THUNDERSTORM ACTIVITY MAINLY SOUTH OF THE CAPITAL REGION AS SOON AS WE GET HEATING...MAINLY MIDDAY AND AFTERNOON. WILL CONTINUE WITH SLIGHT CHANCES OF SHOWERS AND THUNDERSTORMS ALBANY NORTH...LOW CHANCES SOUTH ON WEDNESDAY. WITH LINGERING CLOUDS AND WEAK COOL AIR ADVECTION...WENT WITH THE LOWER END OF GUIDANCE FOR HIGH TEMPERATURES. LOOK FOR HIGHS WEDNESDAY GENERALLY IN THE MID TO UPPER 70S (MORE CLOUDS SOUTH). ANY AND ALL CONVECTION WILL DIMINISH WEDNESDAY NIGHT. WE WILL BE LEFT WITH A MAINLY CLEAR SKY AND PERHAPS SOME PATCHY FOG. DID PUT PATCHY FOG IN THE GRIDS TOMORROW NIGHT AS THE WIND LOOKS CALMER AND LESS IN THE WAY OF CLOUDS. TEMPERATURES WILL DIP INTO 50S. THURSDAY...IT LOOKS AS IF A SECONDARY COLD FRONT AND UPPER LEVEL ENERGY WILL WORK THROUGH TO PRODUCE SOME MORE SCATTERED SHOWERS AND POSSIBLY AFTERNOON THUNDERSTORMS. THE ACTIVITY LOOKS SCATTERED ACROSS THE HIGHER ELEVATIONS AND ISOLATED CAPITAL REGION SOUTHWARD. THE DAY WILL START OUT MAINLY SUNNY...BUT CLOUDS AND THE WIDELY SCATTERED SHOWERS WILL QUICKLY FOLLOW BY AFTERNOON. TEMPERATURES WILL BE SIMILAR TO WEDNESDAY...MAYBE A POINT OR TWO LOWER. IT SHOULD CLEAR OUT THURSDAY NIGHT AND BECOME RATHER COOL. OVERNIGHT LOWS WILL DIP INTO THE LOWER TO MID 50S ALBANY SOUTHWARD...MID TO UPPER 40S FURTHER NORTH. FRIDAY LOOKS LIKE A WINNER WEATHER WISE AS HIGH PRESSURE FROM CANADA BEGINS TO BUILD IN. IT SHOULD BE MOSTLY SUNNY (FEW-SCT FAIR WEATHER CU) AND TEMPERATURES AROUND 80 IN THE VALLEYS...MID TO UPPER 70S HIGHER TERRAIN. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... EXCEPT FOR POSSIBLY THE LAST DAY...THIS WILL BE A STRETCH OF DRY WEATHER AND SEASONABLE TEMPERATURES. HIGH PRESSURE WILL RULE THE ROOST THROUGHOUT. ON TUESDAY...A COLD FRONT FROM THE NORTHWEST MAY MAKE IT CLOSE ENOUGH TO BRING SHOWERS AND THUNDERSTORMS TO THE ADIRONDACKS. RELATIVE HUMIDITIES WILL INCREASE ONLY SLIGHTLY EACH DAY. HIGH TEMPERATURES EACH DAY WILL RANGE FROM THE LOWER AND MID 70S IN THE HIGHEST ELEVATIONS...TO THE LOWER AND MID 80S IN THE VALLEYS. LOW TEMPERATURES WILL GRADUALLY MODERATE SLIGHTLY...WITH LOWS FRIDAY NIGHT FROM MOSTLY THE UPPER 40S IN THE HIGH MOUNTAIN PEAKS...TO THE MID AND UPPER 50S IN THE VALLEYS. BY MONDAY NIGHT...LOWS WILL RANGE FROM THE LOWER AND MID 50S IN THE MOUNTAINS...TO THE LOWER 60S IN THE VALLEYS. FOR THIS PERIOD...NORMAL HIGHS IN ALBANY ARE IN THE LOWER 80S...NORMAL LOWS...AROUND 60 DEGREES. && .AVIATION /21Z TUESDAY THROUGH SUNDAY/... MAINLY VFR FLYING CONDITIONS WILL PERSIST THROUGHOUT THE AFTERNOON HOURS WITH BRIEF PERIODS OF MVFR CONDITIONS ASSOCIATED WITH SHOWERS/THUNDERSTORMS...BEFORE MVFR/IFR FOG RETURNS TONIGHT. THIS AFTERNOON...DAYTIME HEATING HAS HELPED SPAWN SCATTERED TO BROKEN CUMULUS AROUND 5-7 KFT...AND WIDELY SCATTERED SHOWERS AND THUNDERSTORMS AHEAD OF A COLD FRONT APPROACHING FROM THE NORTHWEST. THE SHOWERS AND THUNDERSTORMS WILL BE SCATTERED IN NATURE THROUGHOUT THE AFTERNOON HOURS SO HAVE PLACED VCSH IN THE TAFS WITH TEMPO GROUPS TO ACCOUNT FOR BRIEF REDUCTIONS TO MVFR ASSOCIATED WITH ANY SHOWERS/STORMS. SOME OF THE STORMS MAY CONTAIN HEAVY DOWNPOURS AND GUSTY WINDS. WINDS WILL BE OUT OF THE SOUTH/SOUTHWEST AT 5-10 KNOTS. TONIGHT INTO WEDNESDAY...THE THUNDERSTORM THREAT WILL DIMINISH AFTER SUNSET WITH SOME LINGERING SHOWERS AT THE TAF SITES THROUGH 03Z AS THE COLD FRONT MOVES ACROSS THE REGION. BEHIND THE FRONT...SKIES WILL CLEAR ALLOWING FOR MVFR/IFR FOG TO RETURN TO THE TAF SITES...ESPECIALLY WHERE SIGNIFICANT RAINFALL OCCURS FROM ANY CONVECTION. VFR FLYING CONDITIONS LOOK TO RETURN AFTER 12Z WEDNESDAY AS AN AREA OF HIGH PRESSURE BEGINS TO SLOWLY BUILD INTO THE REGION. WINDS TONIGHT WILL TREND CALM BEFORE BECOMING LIGHT AND VARIABLE AROUND 5 KNOTS WEDNESDAY. OUTLOOK... WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. THURSDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...TSRA. THURSDAY NIGHT THROUGH SUNDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .FIRE WEATHER... SCATTERED SHOWERS AND THUNDERSTORMS THROUGH EVENING...WITH ABOUT HALF THE PLACES RECEIVING A QUARTER INCH OR MORE OF RAINFALL...BUT AREAS NOT RECEIVING ANY. THESE STORMS WILL BE ASSOCIATED WITH A SLOW MOVING COLD FRONT THAT WILL STILL BE WORKING THROUGH AREAS SOUTH OF ALBANY ON WEDNESDAY...THUS CONTINUING THE CHANCES FOR SHOWERS AND THUNDERSTORMS. COVERAGE ON WEDNESDAY WILL BE MORE LIMITED THAN TODAY. A SECONDARY COLD FRONT COULD TRIGGER A FEW MORE SHOWERS AND THUNDERSTORMS ON THURSDAY...MAINLY NORTH AND WEST OF THE CAPITAL REGION. AFTER THAT...IT LOOKS LIKE DRY WEATHER ON THE WEEKEND INTO EARLY NEXT WEEK WITH A NORMAL RECOVERY EACH NIGHT AND RH VALUES GENERALLY 35-45 PERCENT EACH AFTERNOON. && .HYDROLOGY... SCATTERED SHOWERS AND THUNDERSTORMS WILL BE WORKING THROUGH THE REGION THROUGH THE EVENING HOURS. SOME OF THE STORMS HAVE BEEN SLOW MOVING...AND BACKBUILDING...CAPABLE OF PRODUCING RAINFALL IN EXCESS OF AN INCH PER HOUR. LOCALIZED PONDING OF WATER IS POSSIBLE THIS EVENING WITH THESE TYPE OF STORMS...BUT OVERALL...NO SIGNIFICANT HYDRO PROBLEMS ARE ANTICIPATED. WIDELY SCATTERED SHOWERS AND THUNDERSTORMS COULD LINGER FROM THE CAPITAL REGION SOUTHWARD TOMORROW BUT ANY EXCESS RAINFALL WILL PROBABLY BE EVEN MORE LIMITED. ANOTHER COLD FRONT COULD TRIGGER A FEW MORE SHOWERS AND THUNDERSTORMS MAINLY NORTH ON THURSDAY...GENERALLY WITH AN AVERAGE RAINFALL BASIN OF A QUARTER INCH OR LESS. AFTER THAT...DRY WEATHER EXPECTED FRIDAY THROUGH EARLY NEXT WEEK. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...HWJIV NEAR TERM...HWJIV SHORT TERM...HWJIV LONG TERM...ELH AVIATION...IRL FIRE WEATHER...HWJIV HYDROLOGY...HWJIV
AREA FORECAST DISCUSSION
NWS TAUNTON MA
254 PM EDT TUE AUG 5 2014 .SYNOPSIS... SCATTERED SHOWERS AND THUNDERSTORMS ARE ANTICIPATED LATE TODAY AND AGAIN ON WEDNESDAY AS HURRICANE BERTHA PASSES WELL OFFSHORE OF NEW ENGLAND WITH LITTLE IMPACT OTHER THAN HIGH SURF AND DANGEROUS RIP CURRENTS. A COLD FRONT WILL MOVE OFFSHORE WEDNESDAY NIGHT. UPPER TROUGH LINGERS OVER THE REGION THURSDAY AND MOVES EAST DURING FRIDAY. HIGH PRESSURE BUILDS OVER THE REGION FOR THE WEEKEND AND EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 1050 AM UPDATE... MONITORING BOTH KENX AND KOKX RADARS...SAW A LONELY SHOWER MOVE ACROSS CENTRAL VT INTO CENTRAL NH BEFORE DISSIPATING AROUND 14Z. ALSO SEE A BAND OF CUMULUS CLOUDS FORMING ALONG DEVELOPING SEA BREEZE FRONT ACROSS S CT ON LATEST VISIBLE SATELLITE LOOP. WILL CONTINUE TO MONITOR RADAR FOR SHOWER DEVELOPMENT...IF IT OCCURS DURING THE EARLY AFTERNOON. NOTING LATEST HRRR FORECAST RADAR TRENDS INDICATING ISOLD SHOWERS ACROSS S NH/N MA AND POSSIBLY ALONG SEA BREEZE FRONT ACROSS S CT...BUT AGAIN WILL MONITOR. TEMPS HAVE RISEN STEADILY SINCE SUNRISE...WITH READINGS IN THE 70S TO LOWER 80S AT 15Z...UP TO 84 AT KFIT. TEMPS/DEWPTS WERE CLOSE TO FORECASTED TRENDS. HAVE UPDATED GRIDS TO BRING CONDITIONS CURRENT. PREVIOUS DISCUSSION... BERTHA TO THE SE WHILE A BROAD-TROUGH SWEEPS ACROSS THE GREAT LAKES. PREVAILING SUBSIDENCE/DRY AIR /H85-H3/ BETWEEN THE TWO COLLOCATED WITH THE LEFT-ENTRANCE REGION OF THE H3 JET SHOULD RESULT IN QUIET WEATHER ACROSS S NEW ENGLAND INTO AFTERNOON. BUT WITH THE WESTERN APPROACH OF A COLD FRONT ASSOCIATED WITH THE BROAD H5 TROUGH...EXPECT THE INCREASE OF CYCLONIC FLOW AND ENHANCED ASCENT ALLOWING THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS OVER W MA / CT AND SW NH. COULD ALSO SEE ACTIVITY ASSOCIATED WITH LOCALIZED CONVERGENCE ALONG SEA-BREEZE BOUNDARIES. CONSIDERING INSTABILITY OF AROUND 1000 J/KG ALONG WITH 30 KTS OF BULK SHEAR...ORDINARY TO MULTI-CELLULAR CONVECTION IS ANTICIPATED. NOTING FORECAST SOUNDINGS WITH FREEZING LEVELS AROUND 10 KFT ALONG WITH A COMBINATION OF THIN-CAPE AND POTENTIAL INVERTED-V PROFILES... FEEL THERE IS AN ISOLATED THREAT OF HEAVY RAIN...STRONG TO DAMAGING WINDS...AND SMALL HAIL /IN PRIORITY OF CONCERN/. WARM AND HUMID CONDITIONS CONTINUING AS TEMPERATURES WARM TO AROUND THE MID-80S WITH DEWPOINTS RANGING AROUND THE MID-60S. COOLER ALONG THE SHORELINES WITH ANTICIPATED SEA-BREEZES. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... TONIGHT... COLD FRONTAL BOUNDARY CONTINUES TO SWEEP INTO S NEW ENGLAND. EXPECT SCATTERED SHOWER / THUNDERSTORM ACTIVITY...STRONGEST OF WHICH WILL CONTINUE TO BE ACROSS N/W INTERIOR...WEAKENING OVER TIME WITH THE LACK OF DAY-TIME HEATING AND INSTABILITY. FALLING HEIGHTS / CYCLONIC FLOW MAY PROLONG SHOWER ACTIVITY TILL AFTER MIDNIGHT AND TOWARDS THE COASTLINES. OTHERWISE...SOUPY AIR WITH DEWPOINTS AROUND THE MID-60S MAINTAINED BY SW FLOW WILL LIKELY RESULT IN ANOTHER NIGHT OF LOW-CLOUDS AND DENSE FOG FOR PORTIONS OF S/SE NEW ENGLAND ESPECIALLY ALONG THE SHORELINES. DRIER AIR BUILDING IN BEHIND THE FRONT SHOULD KEEP AREAS OF THE N/W INTERIOR FOG-FREE. LOWS NW-SE RANGING FROM THE LOW-60S TO UPPER-60S. WEDNESDAY... SYNOPTICALLY...IGNORE THE PRESSURE PATTERN. BELIEVE THE OVERNIGHT COLD FRONT BECOMES DIFFUSE AS A BROAD AREA OF LOW PRESSURE SITUATED MAINLY ACROSS SE NEW ENGLAND. AS THE MAIN CRUX OF ENERGY SWEEPS THROUGH THE PREVAILING MID-LEVEL BROAD TROUGH...FALLING HEIGHTS ARE INVOKED THROUGHOUT THE ATMOSPHERIC COLUMN. THE COMBINATION OF THE LEFT-FRONT-QUADRANT ASSOCIATED WITH THE H3 CYCLONIC JET...MID- LEVEL ENHANCED ASCENT...AND LOCALIZED CONVERGENCE OF A SOUPY UNSTABLE AIRMASS ALONG SEA-BREEZE BOUNDARIES...DEEP-LAYER ASCENT PREVAILS. ANTICIPATE SCATTERED SHOWER AND THUNDERSTORM ACTIVITY MAINLY ACROSS S/E INTERIOR NEW ENGLAND INCORPORATING E MA AND RI. ASSUMING INSTABILITY VALUES AROUND 1000 J/KG WILL BE MET IN AN ENVIRONMENT OF AVERAGE 30 KT W-E UNI-DIRECTIONAL SHEAR SHOULD YIELD ORDINARY TO MULTI-CELLULAR CONVECTION ALONG THE SEA-BREEZE BOUNDARIES. PWATS RANGE 1.0 - 1.5 INCHES. ONCE AGAIN...NOTING FORECAST SOUNDINGS WITH FREEZING LEVELS AROUND 10 KFT ALONG WITH A COMBINATION OF THIN-CAPE AND POTENTIAL INVERTED-V PROFILES...FEEL THERE IS AN ISOLATED THREAT OF HEAVY RAIN...STRONG TO DAMAGING WINDS...AND SMALL HAIL /IN PRIORITY OF CONCERN/. A GREATER THREAT OF URBAN FLOODING IS CERTAINLY PLAUSIBLE SHOULD STORMS PERPETUATE ALONG THE SEA-BREEZE. WARM AND MUGGY CONDITIONS EXPECTED MORE S/E WITH HIGHS AROUND THE UPPER-70S. COOLER AND DRIER N/W THOUGH LOW-80S POSSIBLE OVER THE LOWER CT-VALLEY. && .LONG TERM /THURSDAY THROUGH TUESDAY/... BIG PICTURE... UPPER TROUGH AND COLD POOL MOVE EAST FROM THE GREAT LAKES...REACHING NEW ENGLAND THURSDAY AND THE MARITIMES FRIDAY. UPPER RIDGE THEN BUILDS OVER THE REGION. THIS SHOULD BRING DRY WEATHER AND WARM TEMPERATURES THROUGH EARLY NEXT WEEK. THE DAILIES... THURSDAY-FRIDAY... COLD AIR ALOFT WITHIN THE UPPER TROUGH WILL DESTABILIZE THE AIRMASS. TOTALS ON THURSDAY ARE EXPECTED TO REACH THE MID 50S...WITH A MOIST LAYER BETWEEN 875 AND 825 MB. EXPECT DIURNAL CUMULUS ALONG WITH SCATTERED SHOWERS/TSTMS THURSDAY. TEMPS ALOFT WARM A LITTLE FRIDAY BUT SIMILAR MOIST LAYER ALOFT. EXPECT DIURNAL CLOUDS FRIDAY BUT WITH MORE ISOLATED SHOWERS. MIXING TO 850 MB THURSDAY AND AT LEAST 825 MB FRIDAY...SUPPORTING MAX TEMPS IN THE UPPER 70S THURSDAY AND LOWER 80S FRIDAY. GFS SUGGESTS SEA BREEZE EACH DAY...PRESSURE GRADIENT SEEMS TO CONFLICT WITH THIS THURSDAY BUT IS SUPPORTIVE FOR FRIDAY. ECMWF SUPPORTS SEA BREEZES BOTH DAYS WITH A WEAK PRESSURE GRADIENT IN PLACE. SATURDAY THROUGH MONDAY... HIGH PRESSURE BUILDS OVER THE REGION. LIGHT WINDS WITH ONSHORE FLOW NEAR THE COAST. TEMPS ALOFT SUPPORT LOW-MID 80S INLAND AND COOLER TEMPS NEAR THE COAST. TUESDAY... HIGH PRESSURE STILL IN CONTROL AND SHOULD PROVIDE A FAIR WEATHER DAY. LOW PRESSURE IN THE SOUTHERN STREAM RACES OUT TO SEA WELL SOUTH OF NEW ENGLAND...BUT COULD SPREAD A FEW CLOUDS OUR WAY ON TUESDAY. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM...THROUGH WEDNESDAY... THIS AFTERNOON...MODERATE CONFIDENCE. EXPECT MAINLY VFR ACROSS MOST AREAS...BUT LOCAL MVFR-IFR MAY LINGER ACROSS KACK THROUGH 18Z OR SO. SOME ISOLD -SHRA/TSRA POSSIBLE...ESPECIALLY INTERIOR TERMINALS. WINDS MAINLY W-SW. SEA BREEZES FOR COASTAL TERMINALS. TONIGHT...MODERATE CONFIDENCE. SHRA/TSRA DISSIPATING AROUND 3Z ACROSS INTERIOR S NEW ENGLAND. WILL SEE THE RETURN OF MVFR-VLIFR CIGS/VSBYS...MAINLY FOR S/E NEW ENGLAND COASTLINES. WEDNESDAY... MVFR-VLIFR CIGS/VSBYS DISSIPATE. SEA-BREEZES AROUND 15Z BECOME THE FOCUS FOR SHRA/TSRA ACROSS INTERIOR E/SE MA AND ALL OF RI. ACTIVITY FURTHER W POSSIBLE. KBOS TERMINAL...MODERATE CONFIDENCE. LIGHT SEA BREEZE THROUGH 22Z-23Z. KBDL TERMINAL...HIGH CONFIDENCE. OUTLOOK...THURSDAY THROUGH SUNDAY...MODERATE CONFIDENCE. THURSDAY-FRIDAY...VFR. BRIEF MVFR CIGS/VSBYS POSSIBLE IN AFTERNOON SHOWER OR THUNDERSTORM...MAINLY THURSDAY. SATURDAY-SUNDAY...VFR. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM...THIS AFTERNOON THROUGH WEDNESDAY... SWELLS WILL INCREASE AS BERTHA MAKES ITS CLOSEST APPROACH LATE TONIGHT. THIS WILL LEND TO INCREASING WAVE HEIGHTS ACROSS THE S/SE WATERS. SMALL CRAFT ADVISORIES FOR HAZARDOUS SEAS ISSUED ACCORDINGLY WITH WAVE HEIGHTS UP TO 7 FEET POSSIBLE. THE DELAY IN SWELL AND LIGHT WINDS FOR TODAY WILL LIMIT THE RIP CURRENT RISK...BUT WILL NEED TO WATCH FOR POTENTIAL HAZARDS TONIGHT INTO WEDNESDAY. LOW CLOUDS AND FOG WILL RETURN LATE TONIGHT INTO WEDNESDAY MORNING...WITH VSBYS AGAIN BELOW 1SM IN SOME AREAS MAINLY S COAST...CAPE COD AND THE ISLANDS. OUTLOOK...THURSDAY THROUGH SUNDAY...MODERATE CONFIDENCE. HIGH PRESSURE BUILDS FROM THE WEST. LINGERING CHANCE OF A THUNDERSTORM THURSDAY AFTERNOON...ESPECIALLY NEARSHORE. THERE MAY BE A LINGERING 5 FOOT SWELL ON THE SOUTHERN OUTER WATERS FROM TROPICAL STORM BERTHA THURSDAY MORNING...BUT THIS SHOULD SUBSIDE DURING THE DAY. OTHERWISE...WINDS AND SEAS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM MIDNIGHT TONIGHT TO 6 PM EDT WEDNESDAY FOR ANZ235-237-254>256. && $$ SYNOPSIS...WTB/SIPPRELL NEAR TERM...DOODY/SIPPRELL/EVT SHORT TERM...SIPPRELL LONG TERM...WTB AVIATION...WTB/SIPPRELL MARINE...WTB/SIPPRELL/EVT
AREA FORECAST DISCUSSION
NWS ALBANY NY
138 PM EDT TUE AUG 5 2014 .SYNOPSIS... PARTLY SUNNY AND WARM WEATHER IS EXPECTED TODAY. A SLOW MOVING COLD FRONT APPROACHING FROM SOUTHERN CANADA WILL BRING A CHANCE FOR THUNDERSTORMS ACROSS MUCH OF THE AREA LATER TODAY AND WEDNESDAY BEFORE CLEARING THE REGION. COOL AND BREEZY WEATHER...WITH A CONTINUED THREAT OF AFTERNOON SHOWERS...IS FORECAST FOR THURSDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 100 PM EDT...WIDELY SCATTERED SHOWERS AND THUNDERSTORMS WERE BEGINNING TO POPPING UP ACROSS MUCH OF AREA. IT APPEARS OUR CAP MIGHT BE BREAKING ALREADY. THE BUF RAOB INDICATED LESS CAPPING AS THE ATMOSPHERE ALOFT BEGINS COOLING OFF AHEAD OF A COLD FRONT. STORMS COULD BECOME MORE PRONOUNCED LATER ON. WE WERE FOLLOWING A CLUSTER OF THUNDERSTORMS WORKING TOWARD EXTREME SW NY. THE LATEST HRRR MODEL INDICATED THESE WOULD HOLD TOGETHER AND MAKE INTO OUR REGION AROUND 00Z-02Z...MAINLY SOUTH OF ALBANY...BUT THEN TRANSITIONING INTO A MORE SYNOPTIC RAIN EVENT. THIS IDEA WAS NOT SUPPORT BY LATEST NAM AND GFS MODELS NOR THE LOCAL HIRESWRF. WE WILL CONTINUE TO MONITOR BUT FOR NOW EXPECT CONVECTIVE ACTIVITY WILL PICK UP A LITTLE THIS AFTERNOON DUE TO DIURNAL HEATING AND COOLING ALOFT. THE CLUSTER...OR WHAT IS LEFT OF IT...WILL MAKE IT INTO A PORTION OF AREA THIS EVENING...ASSUMING IT CAN HOLD TOGETHER. THUNDERSTORMS LATER THIS AFTERNOON...COULD PRODUCE LOCALIZED WIND GUSTS AND HEAVY RAINFALL...BUT THE THREAT WAS DEEMED TOO LOW TO ADD ENHANCED WORDING TO THUNDERSTORMS AT THIS TIME. WITH STRONG DAYTIME HEATING EXPECTED...TEMPS WILL REACH INTO THE MID AND UPPER 80S ACROSS MUCH OF THE REGION EXCEPT FOR UPPER 70S TO LOW 80S ACROSS THE SOUTHERN ADIRONDACKS. COMBINED WITH DEWPOINTS IN THE LOW TO MID 60S AND MARGINAL MIDLEVEL LAPSE RATES AROUND 6.0 C/KM...AROUND 500-1500 J/KG OF SBCAPE IS EXPECTED BY MID AFTERNOON. THERE WILL BE LITTLE IN THE WAY OF DYNAMIC FORCING ACROSS THE REGION...AS A COLD FRONT REMAINS FAR ENOUGH NORTH AND WEST TO ALLOW FOR LOCAL TOPOGRAPHIC/DIFFERENTIAL HEATING BOUNDARIES TO BE THE PRIMARY FOCUS FOR CONVECTION. THE HRRR DEPICTS WIDELY SCATTERED TO SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING BETWEEN 12PM-2PM...AND PERSISTING THROUGH MUCH OF THE AFTERNOON BEFORE A DECAYING CLUSTER OF STORMS CURRENTLY ACROSS THE LOWER GREAT LAKES REACHES THE REGION BY THE LATE EVENING HOURS. ALTHOUGH THERE WILL BE MODEST INSTABILITY IN PLACE...MEAGER DYNAMIC FORCING WILL RESULT IN MAINLY GENERIC THUNDERSTORM ACTIVITY WITH THE STRONGEST STORMS CAPABLE OF BRIEF HEAVY DOWNPOURS THAT MAY PRODUCE LOCALIZED PONDING OF WATER ON ROADWAYS AS WELL AS IN LOW LYING AND URBAN AREAS. HAVE ONLY GONE WITH SLIGHT CHANCE AND CHANCE POPS AS COVERAGE WILL BE SCATTERED AT BEST. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/... ANY LINGERING SHOWERS OR THUNDERSTORMS SHOULD DISSIPATE THROUGH THE EVENING...WITH INTERVALS OF CLOUDS THE REST OF THE NIGHT. THE BETTER UPPER DYNAMICS ASSOCIATED WITH THE UPPER SYSTEM...AND THE BETTER LOW LEVEL FORCING ALONG A TIGHTENING AND ADVANCING BOUNDARY LAYER THERMAL GRADIENT SHOULD SUPPORT SCATTERED SHOWERS AND THUNDERSTORMS WEDNESDAY...MAINLY AFTERNOON AND EVENING. HIGHS WEDNESDAY IN THE MID 70S TO LOWER 80S. ONE LAST LINGERING PIECE OF UPPER ENERGY AND THE UPPER COLD POOL BRUSH JUST NORTH AND NORTHEAST OF OUR REGION THURSDAY SUPPORTING ONE LAST ROUND OF ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS...MAINLY IN NORTHERN AND EASTERN AREAS. COOLING CONTINUES TO TAKE PLACE ACROSS THE REGION...AND HIGHS SHOULD BE IN THE 70S TO NEAR 80. NIGHTTIME LOWS TONIGHT SHOULD BE IN THE UPPER 50S TO LOWER 60S...COOLER IN HIGHER TERRAIN. FOR WEDNESDAY NIGHT AND THURSDAY NIGHT LOWS IN THE 50S WITH AROUND 50 HIGHER TERRAIN. && .LONG TERM /FRIDAY THROUGH TUESDAY/... FRIDAY WE WILL DEALING WITH THE LAST VESTIGES OF A CYCLONIC FLOW REGIME...WITH POTENTIALLY ONE FINAL WEAK DISTURBANCE ROTATING AROUND THE WESTERN PERIPHERY OF AN UPPER LOW OVER THE CANADIAN MARITIMES. SO WILL MENTION JUST SLIGHT CHANCE POPS FOR WESTERN NEW ENGLAND...BEFORE TRANQUIL CONDITIONS DEVELOP FRIDAY NIGHT AS THE FLOW STARTS TO BECOME MORE ANTICYCLONIC. THE WEEKEND LOOKS TO FEATURE PLENTY OF SUNSHINE AND SEASONABLE TEMPERATURES...AS A RIDGE OF HIGH PRESSURE BOTH AT THE SURFACE AND ALOFT BECOMES ESTABLISHED ACROSS THE REGION. THE 00Z GFS IS ACTUALLY DEVELOPING SOME CONVECTION ON SUNDAY UNDERNEATH THE RIDGE...WHICH IN THE ABSENCE OF ANY SIGNIFICANT MOISTURE AND INSTABILITY LOOKS RATHER SUSPECT. WILL LEAN TOWARD THE 00Z ECMWF WHICH IS INDICATING RAIN-FREE CONDITIONS UNDER THE RIDGE. QUIET WEATHER SHOULD CONTINUE INTO EARLY NEXT WEEK WITH THE RIDGE STILL EXPECTED TO BE IN PLACE ACROSS THE NORTHEAST CONUS. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... MAINLY VFR FLYING CONDITIONS WILL PERSIST THROUGHOUT THE AFTERNOON HOURS WITH BRIEF PERIODS OF MVFR CONDITIONS ASSOCIATED WITH SHOWERS/THUNDERSTORMS...BEFORE MVFR/IFR FOG RETURNS TONIGHT. THIS AFTERNOON...DAYTIME HEATING HAS HELPED SPAWN SCATTERED TO BROKEN CUMULUS AROUND 5-7 KFT...AND WIDELY SCATTERED SHOWERS AND THUNDERSTORMS AHEAD OF A COLD FRONT APPROACHING FROM THE NORTHWEST. THE SHOWERS AND THUNDERSTORMS WILL BE SCATTERED IN NATURE THROUGHOUT THE AFTERNOON HOURS SO HAVE PLACED VCSH IN THE TAFS WITH TEMPO GROUPS TO ACCOUNT FOR BRIEF REDUCTIONS TO MVFR ASSOCIATED WITH ANY SHOWERS/STORMS. SOME OF THE STORMS MAY CONTAIN HEAVY DOWNPOURS AND GUSTY WINDS. WINDS WILL BE OUT OF THE SOUTH/SOUTHWEST AT 5-10 KNOTS. TONIGHT INTO WEDNESDAY...THE THUNDERSTORM THREAT WILL DIMINISH AFTER SUNSET WITH SOME LINGERING SHOWERS AT THE TAF SITES THROUGH 03Z AS THE COLD FRONT MOVES ACROSS THE REGION. BEHIND THE FRONT...SKIES WILL CLEAR ALLOWING FOR MVFR/IFR FOG TO RETURN TO THE TAF SITES...ESPECIALLY WHERE SIGNIFICANT RAINFALL OCCURS FROM ANY CONVECTION. VFR FLYING CONDITIONS LOOK TO RETURN AFTER 12Z WEDNESDAY AS AN AREA OF HIGH PRESSURE BEGINS TO SLOWLY BUILD INTO THE REGION. WINDS TONIGHT WILL TREND CALM BEFORE BECOMING LIGHT AND VARIABLE AROUND 5 KNOTS WEDNESDAY. OUTLOOK... WEDNESDAY NIGHT: SLIGHT CHANCE OF SHRA. THURSDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX. FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SUNDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .FIRE WEATHER... A SLOW MOVING COLD FRONT APPROACHING FROM SOUTHERN CANADA WILL BRING A CHANCE FOR THUNDERSTORMS ACROSS MUCH OF THE AREA ON TUESDAY AND WEDNESDAY BEFORE CLEARING THE REGION. MINIMUM RELATIVE HUMIDITIES THIS AFTERNOON AND TOMORROW AFTERNOON SHOULD RANGE IN THE 40 TO 55 PERCENT RANGE. NIGHTTIME RH VALUES SHOULD BE 70 TO 100 PERCENT. WINDS WILL BE WEST TO NORTHWEST AT 15 MPH OR LESS THROUGH THE PERIOD. && .HYDROLOGY... SCATTERED SHOWERS AND THUNDERSTORMS CAN BE EXPECTED EACH AFTERNOON AND EVENING THROUGH WEDNESDAY ASSOCIATED WITH AN ADVANCING COLD FRONT. THE THREAT OF ISOLATED FLOODING OF POOR DRAINAGE AND URBAN AREAS WILL CONTINUE THIS AFTERNOON THROUGH WEDNESDAY... MAINLY IF THUNDERSTORMS REPEATEDLY PASS OVER THE SAME LOCATIONS. DUE TO THE CONVECTIVE NATURE OF THE RAINFALL...MOST RIVER BASINS WILL NOT EXPERIENCE MUCH IMPACT. SOME RISES MAY OCCUR FOR AREAS THAT SEE REPEATED RAINFALL THROUGH MIDWEEK. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...NAS NEAR TERM...SND/HWJIV/IRL SHORT TERM...NAS LONG TERM...JPV AVIATION...IRL FIRE WEATHER...NAS HYDROLOGY...NAS
AREA FORECAST DISCUSSION
NWS ALBANY NY
0100 PM EDT TUE AUG 5 2014 .SYNOPSIS... PARTLY SUNNY AND WARM WEATHER IS EXPECTED TODAY. A SLOW MOVING COLD FRONT APPROACHING FROM SOUTHERN CANADA WILL BRING A CHANCE FOR THUNDERSTORMS ACROSS MUCH OF THE AREA LATER TODAY AND WEDNESDAY BEFORE CLEARING THE REGION. COOL AND BREEZY WEATHER...WITH A CONTINUED THREAT OF AFTERNOON SHOWERS...IS FORECAST FOR THURSDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 100 PM EDT...WIDELY SCATTERED SHOWERS AND THUNDERSTORMS WERE BEGINNING TO POPPING UP ACROSS MUCH OF AREA. IT APPEARS OUR CAP MIGHT BE BREAKING ALREADY. THE BUF RAOB INDICATED LESS CAPPING AS THE ATMOSPHERE ALOFT BEGINS COOLING OFF AHEAD OF A COLD FRONT. STORMS COULD BECOME MORE PRONOUNCED LATER ON. WE WERE FOLLOWING A CLUSTER OF THUNDERSTORMS WORKING TOWARD EXTREME SW NY. THE LATEST HRRR MODEL INDICATED THESE WOULD HOLD TOGETHER AND MAKE INTO OUR REGION AROUND 00Z-02Z...MAINLY SOUTH OF ALBANY...BUT THEN TRANSITIONING INTO A MORE SYNOPTIC RAIN EVENT. THIS IDEA WAS NOT SUPPORT BY LATEST NAM AND GFS MODELS NOR THE LOCAL HIRESWRF. WE WILL CONTINUE TO MONITOR BUT FOR NOW EXPECT CONVECTIVE ACTIVITY WILL PICK UP A LITTLE THIS AFTERNOON DUE TO DIURNAL HEATING AND COOLING ALOFT. THE CLUSTER...OR WHAT IS LEFT OF IT...WILL MAKE IT INTO A PORTION OF AREA THIS EVENING...ASSUMING IT CAN HOLD TOGETHER. THUNDERSTORMS LATER THIS AFTERNOON...COULD PRODUCE LOCALIZED WIND GUSTS AND HEAVY RAINFALL...BUT THE THREAT WAS DEEMED TOO LOW TO ADD ENHANCED WORDING TO THUNDERSTORMS AT THIS TIME. WITH STRONG DAYTIME HEATING EXPECTED...TEMPS WILL REACH INTO THE MID AND UPPER 80S ACROSS MUCH OF THE REGION EXCEPT FOR UPPER 70S TO LOW 80S ACROSS THE SOUTHERN ADIRONDACKS. COMBINED WITH DEWPOINTS IN THE LOW TO MID 60S AND MARGINAL MIDLEVEL LAPSE RATES AROUND 6.0 C/KM...AROUND 500-1500 J/KG OF SBCAPE IS EXPECTED BY MID AFTERNOON. THERE WILL BE LITTLE IN THE WAY OF DYNAMIC FORCING ACROSS THE REGION...AS A COLD FRONT REMAINS FAR ENOUGH NORTH AND WEST TO ALLOW FOR LOCAL TOPOGRAPHIC/DIFFERENTIAL HEATING BOUNDARIES TO BE THE PRIMARY FOCUS FOR CONVECTION. THE HRRR DEPICTS WIDELY SCATTERED TO SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING BETWEEN 12PM-2PM...AND PERSISTING THROUGH MUCH OF THE AFTERNOON BEFORE A DECAYING CLUSTER OF STORMS CURRENTLY ACROSS THE LOWER GREAT LAKES REACHES THE REGION BY THE LATE EVENING HOURS. ALTHOUGH THERE WILL BE MODEST INSTABILITY IN PLACE...MEAGER DYNAMIC FORCING WILL RESULT IN MAINLY GENERIC THUNDERSTORM ACTIVITY WITH THE STRONGEST STORMS CAPABLE OF BRIEF HEAVY DOWNPOURS THAT MAY PRODUCE LOCALIZED PONDING OF WATER ON ROADWAYS AS WELL AS IN LOW LYING AND URBAN AREAS. HAVE ONLY GONE WITH SLIGHT CHANCE AND CHANCE POPS AS COVERAGE WILL BE SCATTERED AT BEST. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/... ANY LINGERING SHOWERS OR THUNDERSTORMS SHOULD DISSIPATE THROUGH THE EVENING...WITH INTERVALS OF CLOUDS THE REST OF THE NIGHT. THE BETTER UPPER DYNAMICS ASSOCIATED WITH THE UPPER SYSTEM...AND THE BETTER LOW LEVEL FORCING ALONG A TIGHTENING AND ADVANCING BOUNDARY LAYER THERMAL GRADIENT SHOULD SUPPORT SCATTERED SHOWERS AND THUNDERSTORMS WEDNESDAY...MAINLY AFTERNOON AND EVENING. HIGHS WEDNESDAY IN THE MID 70S TO LOWER 80S. ONE LAST LINGERING PIECE OF UPPER ENERGY AND THE UPPER COLD POOL BRUSH JUST NORTH AND NORTHEAST OF OUR REGION THURSDAY SUPPORTING ONE LAST ROUND OF ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS...MAINLY IN NORTHERN AND EASTERN AREAS. COOLING CONTINUES TO TAKE PLACE ACROSS THE REGION...AND HIGHS SHOULD BE IN THE 70S TO NEAR 80. NIGHTTIME LOWS TONIGHT SHOULD BE IN THE UPPER 50S TO LOWER 60S...COOLER IN HIGHER TERRAIN. FOR WEDNESDAY NIGHT AND THURSDAY NIGHT LOWS IN THE 50S WITH AROUND 50 HIGHER TERRAIN. && .LONG TERM /FRIDAY THROUGH MONDAY/... FRIDAY WE WILL DEALING WITH THE LAST VESTIGES OF A CYCLONIC FLOW REGIME...WITH POTENTIALLY ONE FINAL WEAK DISTURBANCE ROTATING AROUND THE WESTERN PERIPHERY OF AN UPPER LOW OVER THE CANADIAN MARITIMES. SO WILL MENTION JUST SLIGHT CHANCE POPS FOR WESTERN NEW ENGLAND...BEFORE TRANQUIL CONDITIONS DEVELOP FRIDAY NIGHT AS THE FLOW STARTS TO BECOME MORE ANTICYCLONIC. THE WEEKEND LOOKS TO FEATURE PLENTY OF SUNSHINE AND SEASONABLE TEMPERATURES...AS A RIDGE OF HIGH PRESSURE BOTH AT THE SURFACE AND ALOFT BECOMES ESTABLISHED ACROSS THE REGION. THE 00Z GFS IS ACTUALLY DEVELOPING SOME CONVECTION ON SUNDAY UNDERNEATH THE RIDGE...WHICH IN THE ABSENCE OF ANY SIGNIFICANT MOISTURE AND INSTABILITY LOOKS RATHER SUSPECT. WILL LEAN TOWARD THE 00Z ECMWF WHICH IS INDICATING RAIN-FREE CONDITIONS UNDER THE RIDGE. QUIET WEATHER SHOULD CONTINUE INTO EARLY NEXT WEEK WITH THE RIDGE STILL EXPECTED TO BE IN PLACE ACROSS THE NORTHEAST CONUS. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... SATELLITE PICTURES SHOW RADIATION FOG IN MANY OF THE VALLEYS OF EASTERN NEW YORK AND WESTERN NEW ENGLAND. VARIOUS WEB CAMS AROUND THE AREA SHOW THE FOG STEADILY BURNING OFF. MOST OF THE FOG SHOULD BE GONE FROM THE TAF SITES BY 13Z EXCEPT KPSF WHERE IT MAY LINGER UNTIL 14Z. VFR CONDITIONS EXPECTED FOR MOST OF THE DAYLIGHT HOURS. A DISTURBANCE MOVING THROUGH COULD TRIGGER SCATTERED THUNDERSTORMS THIS AFTERNOON...SO HAVE PLACED VCSH IN ALL TAFS STARTING AROUND 19Z OR 20Z. THUNDERSTORMS COULD PRODUCE SOME MVFR AT TAF SITES BUT COVERAGE IS NOT EXPECTED TO BE WIDESPREAD ENOUGH TO PUT THUNDERSTORMS IN THE TAFS. THESE STORMS SHOULD DISSIPATE AFTER SUNSET...WITH SOME PATCHY VALLEY FOG RETURNING WEDNESDAY MORNING. WINDS ARE FORECAST TO BE FROM THE WEST TODAY AND TONIGHT AT 5 TO 15 KNOTS. OUTLOOK... WEDNESDAY NIGHT: SLIGHT CHANCE OF SHRA. THURSDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX. FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SUNDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .FIRE WEATHER... A SLOW MOVING COLD FRONT APPROACHING FROM SOUTHERN CANADA WILL BRING A CHANCE FOR THUNDERSTORMS ACROSS MUCH OF THE AREA ON TUESDAY AND WEDNESDAY BEFORE CLEARING THE REGION. MINIMUM RELATIVE HUMIDITIES THIS AFTERNOON AND TOMORROW AFTERNOON SHOULD RANGE IN THE 40 TO 55 PERCENT RANGE. NIGHTTIME RH VALUES SHOULD BE 70 TO 100 PERCENT. WINDS WILL BE WEST TO NORTHWEST AT 15 MPH OR LESS THROUGH THE PERIOD. && .HYDROLOGY... SCATTERED SHOWERS AND THUNDERSTORMS CAN BE EXPECTED EACH AFTERNOON AND EVENING THROUGH WEDNESDAY ASSOCIATED WITH AN ADVANCING COLD FRONT. THE THREAT OF ISOLATED FLOODING OF POOR DRAINAGE AND URBAN AREAS WILL CONTINUE THIS AFTERNOON THROUGH WEDNESDAY... MAINLY IF THUNDERSTORMS REPEATEDLY PASS OVER THE SAME LOCATIONS. DUE TO THE CONVECTIVE NATURE OF THE RAINFALL...MOST RIVER BASINS WILL NOT EXPERIENCE MUCH IMPACT. SOME RISES MAY OCCUR FOR AREAS THAT SEE REPEATED RAINFALL THROUGH MIDWEEK. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...NAS NEAR TERM...SND/HWJIV/IRL SHORT TERM...NAS LONG TERM...JPV AVIATION...SND/JPV FIRE WEATHER...NAS HYDROLOGY...NAS
AREA FORECAST DISCUSSION
NWS ALBANY NY
1231 PM EDT TUE AUG 5 2014 .SYNOPSIS... PARTLY SUNNY AND WARM WEATHER IS EXPECTED TODAY. A SLOW MOVING COLD FRONT APPROACHING FROM SOUTHERN CANADA WILL BRING A CHANCE FOR THUNDERSTORMS ACROSS MUCH OF THE AREA LATER TODAY AND WEDNESDAY BEFORE CLEARING THE REGION. COOL AND BREEZY WEATHER...WITH A CONTINUED THREAT OF AFTERNOON SHOWERS...IS FORECAST FOR THURSDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 1230 PM EDT...ONE SHOWER BRIEFLY POPPED UP OVER SOUTHERN ALBANY COUNTY...WHILE A FEW MORE OVER THE CATSKILLS. WE BELIEVE THERE WILL BE MORE RANDOM POP UP SHOWERS POSSIBLY DEVELOPING INTO THE THUNDERSTORMS. OUR ALY RAOB INDICATED WE WERE CAPPED SO INITIALLY CELLS SHOULD NOT GROW THAT TALL. HOWEVER...THE BUF RAOB INDICATED LESS CAPPING AS THE ATMOSPHERE ALOFT BEGINS COOLING OFF AHEAD OF A COLD FRONT. STORMS COULD BECOME MORE PRONOUNCED LATER ON. WE WERE FOLLOWING A CLUSTER OF THUNDERSTORMS WORKING TOWARD EXTREME SW NY. THE LATEST HRRR MODEL INDICATED THESE WOULD HOLD TOGETHER AND MAKE INTO OUR REGION AROUND 00Z-02Z...MAINLY SOUTH OF ALBANY...BUT THEN TRANSITIONING INTO A MORE SYNOPTIC RAIN EVENT. THIS IDEA WAS NOT SUPPORT BY LATEST NAM AND GFS MODELS NOR THE LOCAL HIRESWRF. WE WILL CONTINUE TO MONITOR BUT FOR NOW EXPECT CONVECTIVE ACTIVITY WILL PICK UP A LITTLE THIS AFTERNOON DUE TO DIURNAL HEATING AND COOLING ALOFT. THE CLUSTER...OR WHAT IS LEFT OF IT...WILL MAKE IT INTO A PORTION OF AREA THIS EVENING...ASSUMING IT CAN HOLD TOGETHER. THUNDERSTORMS LATER THIS AFTERNOON...COULD PRODUCE LOCALIZED WIND GUSTS AND HEAVY RAINFALL...BUT THE THREAT WAS DEEMED TOO LOW TO ADD ENHANCED WORDING TO THUNDERSTORMS AT THIS TIME. WITH STRONG DAYTIME HEATING EXPECTED...TEMPS WILL REACH INTO THE MID AND UPPER 80S ACROSS MUCH OF THE REGION EXCEPT FOR UPPER 70S TO LOW 80S ACROSS THE SOUTHERN ADIRONDACKS. COMBINED WITH DEWPOINTS IN THE LOW TO MID 60S AND MARGINAL MIDLEVEL LAPSE RATES AROUND 6.0 C/KM...AROUND 500-1500 J/KG OF SBCAPE IS EXPECTED BY MID AFTERNOON. THERE WILL BE LITTLE IN THE WAY OF DYNAMIC FORCING ACROSS THE REGION...AS A COLD FRONT REMAINS FAR ENOUGH NORTH AND WEST TO ALLOW FOR LOCAL TOPOGRAPHIC/DIFFERENTIAL HEATING BOUNDARIES TO BE THE PRIMARY FOCUS FOR CONVECTION. THE HRRR DEPICTS WIDELY SCATTERED TO SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING BETWEEN 12PM-2PM...AND PERSISTING THROUGH MUCH OF THE AFTERNOON BEFORE A DECAYING CLUSTER OF STORMS CURRENTLY ACROSS THE LOWER GREAT LAKES REACHES THE REGION BY THE LATE EVENING HOURS. ALTHOUGH THERE WILL BE MODEST INSTABILITY IN PLACE...MEAGER DYNAMIC FORCING WILL RESULT IN MAINLY GENERIC THUNDERSTORM ACTIVITY WITH THE STRONGEST STORMS CAPABLE OF BRIEF HEAVY DOWNPOURS THAT MAY PRODUCE LOCALIZED PONDING OF WATER ON ROADWAYS AS WELL AS IN LOW LYING AND URBAN AREAS. HAVE ONLY GONE WITH SLIGHT CHANCE AND CHANCE POPS AS COVERAGE WILL BE SCATTERED AT BEST. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/... ANY LINGERING SHOWERS OR THUNDERSTORMS SHOULD DISSIPATE THROUGH THE EVENING...WITH INTERVALS OF CLOUDS THE REST OF THE NIGHT. THE BETTER UPPER DYNAMICS ASSOCIATED WITH THE UPPER SYSTEM...AND THE BETTER LOW LEVEL FORCING ALONG A TIGHTENING AND ADVANCING BOUNDARY LAYER THERMAL GRADIENT SHOULD SUPPORT SCATTERED SHOWERS AND THUNDERSTORMS WEDNESDAY...MAINLY AFTERNOON AND EVENING. HIGHS WEDNESDAY IN THE MID 70S TO LOWER 80S. ONE LAST LINGERING PIECE OF UPPER ENERGY AND THE UPPER COLD POOL BRUSH JUST NORTH AND NORTHEAST OF OUR REGION THURSDAY SUPPORTING ONE LAST ROUND OF ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS...MAINLY IN NORTHERN AND EASTERN AREAS. COOLING CONTINUES TO TAKE PLACE ACROSS THE REGION...AND HIGHS SHOULD BE IN THE 70S TO NEAR 80. NIGHTTIME LOWS TONIGHT SHOULD BE IN THE UPPER 50S TO LOWER 60S...COOLER IN HIGHER TERRAIN. FOR WEDNESDAY NIGHT AND THURSDAY NIGHT LOWS IN THE 50S WITH AROUND 50 HIGHER TERRAIN. && .LONG TERM /FRIDAY THROUGH MONDAY/... FRIDAY WE WILL DEALING WITH THE LAST VESTIGES OF A CYCLONIC FLOW REGIME...WITH POTENTIALLY ONE FINAL WEAK DISTURBANCE ROTATING AROUND THE WESTERN PERIPHERY OF AN UPPER LOW OVER THE CANADIAN MARITIMES. SO WILL MENTION JUST SLIGHT CHANCE POPS FOR WESTERN NEW ENGLAND...BEFORE TRANQUIL CONDITIONS DEVELOP FRIDAY NIGHT AS THE FLOW STARTS TO BECOME MORE ANTICYCLONIC. THE WEEKEND LOOKS TO FEATURE PLENTY OF SUNSHINE AND SEASONABLE TEMPERATURES...AS A RIDGE OF HIGH PRESSURE BOTH AT THE SURFACE AND ALOFT BECOMES ESTABLISHED ACROSS THE REGION. THE 00Z GFS IS ACTUALLY DEVELOPING SOME CONVECTION ON SUNDAY UNDERNEATH THE RIDGE...WHICH IN THE ABSENCE OF ANY SIGNIFICANT MOISTURE AND INSTABILITY LOOKS RATHER SUSPECT. WILL LEAN TOWARD THE 00Z ECMWF WHICH IS INDICATING RAIN-FREE CONDITIONS UNDER THE RIDGE. QUIET WEATHER SHOULD CONTINUE INTO EARLY NEXT WEEK WITH THE RIDGE STILL EXPECTED TO BE IN PLACE ACROSS THE NORTHEAST CONUS. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... SATELLITE PICTURES SHOW RADIATION FOG IN MANY OF THE VALLEYS OF EASTERN NEW YORK AND WESTERN NEW ENGLAND. VARIOUS WEB CAMS AROUND THE AREA SHOW THE FOG STEADILY BURNING OFF. MOST OF THE FOG SHOULD BE GONE FROM THE TAF SITES BY 13Z EXCEPT KPSF WHERE IT MAY LINGER UNTIL 14Z. VFR CONDITIONS EXPECTED FOR MOST OF THE DAYLIGHT HOURS. A DISTURBANCE MOVING THROUGH COULD TRIGGER SCATTERED THUNDERSTORMS THIS AFTERNOON...SO HAVE PLACED VCSH IN ALL TAFS STARTING AROUND 19Z OR 20Z. THUNDERSTORMS COULD PRODUCE SOME MVFR AT TAF SITES BUT COVERAGE IS NOT EXPECTED TO BE WIDESPREAD ENOUGH TO PUT THUNDERSTORMS IN THE TAFS. THESE STORMS SHOULD DISSIPATE AFTER SUNSET...WITH SOME PATCHY VALLEY FOG RETURNING WEDNESDAY MORNING. WINDS ARE FORECAST TO BE FROM THE WEST TODAY AND TONIGHT AT 5 TO 15 KNOTS. OUTLOOK... WEDNESDAY NIGHT: SLIGHT CHANCE OF SHRA. THURSDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX. FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SUNDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .FIRE WEATHER... A SLOW MOVING COLD FRONT APPROACHING FROM SOUTHERN CANADA WILL BRING A CHANCE FOR THUNDERSTORMS ACROSS MUCH OF THE AREA ON TUESDAY AND WEDNESDAY BEFORE CLEARING THE REGION. MINIMUM RELATIVE HUMIDITIES THIS AFTERNOON AND TOMORROW AFTERNOON SHOULD RANGE IN THE 40 TO 55 PERCENT RANGE. NIGHTTIME RH VALUES SHOULD BE 70 TO 100 PERCENT. WINDS WILL BE WEST TO NORTHWEST AT 15 MPH OR LESS THROUGH THE PERIOD. && .HYDROLOGY... SCATTERED SHOWERS AND THUNDERSTORMS CAN BE EXPECTED EACH AFTERNOON AND EVENING THROUGH WEDNESDAY ASSOCIATED WITH AN ADVANCING COLD FRONT. THE THREAT OF ISOLATED FLOODING OF POOR DRAINAGE AND URBAN AREAS WILL CONTINUE THIS AFTERNOON THROUGH WEDNESDAY... MAINLY IF THUNDERSTORMS REPEATEDLY PASS OVER THE SAME LOCATIONS. DUE TO THE CONVECTIVE NATURE OF THE RAINFALL...MOST RIVER BASINS WILL NOT EXPERIENCE MUCH IMPACT. SOME RISES MAY OCCUR FOR AREAS THAT SEE REPEATED RAINFALL THROUGH MIDWEEK. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...NAS NEAR TERM...SND/HWJIV/IRL SHORT TERM...NAS LONG TERM...JPV AVIATION...SND/JPV FIRE WEATHER...NAS HYDROLOGY...NAS
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
207 PM CDT TUE AUG 5 2014 .DISCUSSION... 1013 AM CDT NO BIG CHANGES TO GOING FORECAST FOR TODAY. VISIBLE SATELLITE IMAGERY SHOWS FAIRLY EXTENSIVE STRATUS ACROSS THE CWA THIS MORNING. THE HIGH SUN ANGLE AND LACK OF LOW LEVEL INVERSION TO TRAP THIS MOISTURE WOULD SUGGEST THAT IT SHOULD MIX OUT THIS AFTERNOON WITH AT LEAST PARTIAL CLEARING. GIVEN THE ANTICIPATED SUNSHINE MADE NO CHANGES TO GOING HIGH TEMP FORECAST FOR TODAY...BUT DID SLOW THE TEMP RISE IN THE HOURLY GRIDS INTO EARLY AFTERNOON DUE TO THE CLOUDINESS. ILL DEFINED COLD FRONT WILL CONTINUE SAG SLOWLY SOUTH ACROSS THE AREA THIS AFTERNOON...BUT LOW LEVEL CONVERGENCE ALONG THE FRONT WILL BE QUITE WEAK AND WATER VAPOR IMAGERY AND MODEL GUIDANCE DO NOT SHOW ANY UPSTREAM SHORTWAVES TO ENHANCE LARGE SCALE ASCENT. DESPITE THESE NEGATIVES...MODIFYING THE ILX 12Z SOUNDING FOR EXPECTED AFTERNOON CONDITIONS YIELDS SEVERAL HUNDRED JOULES OF MLCAPE WITH LITTLE INHIBITION...SO STILL POSSIBLE THAT ISOLATED SHRA/TSRA COULD DEVELOP OVER SOUTHEAST CWA THIS AFTERNOON. IZZI //PREV DISCUSSION... 355 AM CDT FORECAST CONCERNS FOCUS ON RAIN AND THUNDER CHANCES DIMINISHING FROM THE NORTH TODAY AS WEAK COLD FRONT CONTINUES TO SAG SOUTH ACROSS THE FORECAST AREA...AND AGAIN WEDNESDAY INTO THURSDAY AS ANOTHER SHORT WAVE AND JET STREAK DIG SOUTHEAST ACROSS THE REGION. AREA OF RAIN/THUNDERSTORMS HAS PUSHED SOUTHEAST ACROSS THE FORECAST AREA SINCE YESTERDAY AFTERNOON IN ASSOCIATION WITH A WEAK COLD FRONT AND A DIGGING MID-LEVEL SHORT WAVE TROUGH. MOST OF THE RAIN WAS SOUTHEAST OF A PRINCETON ILLINOIS TO GARY INDIANA LINE AS OF 3 AM AND SHOULD CONTINUE TO FOCUS OVER THE SOUTHEAST THIRD OR SO OF THE CWA THIS MORNING AS THE MID-LEVEL WAVE AND AN EMBEDDED MCV PROPAGATE INTO INDIANA. HARD TO PLACE THE ACTUAL COLD FRONTAL BOUNDARY GIVEN LIGHT GRADIENT AND CONVECTIVE OUTFLOW CONTAMINATED SURFACE WIND FIELD...THOUGH IT APPEARS TO BE SOMEWHERE FROM NORTH OF KORD TO KDKB TO SOUTH OF KSQI IN LATEST SURFACE ANALYSIS. FRONT IS PROGGED TO CONTINUE TO DRIFT SOUTHEAST THIS MORNING BEHIND WEAK SURFACE WAVE WITH BEST POTENTIAL FOR DIURNAL SHOWER/THUNDERSTORM DEVELOPMENT LATER THIS MORNING AND THIS AFTERNOON TO BE ALONG/SOUTH OF THE FRONT ACROSS THE SOUTH/SOUTHEAST PART OF THE CWA. ALSO...WITH LITTLE PUSH TO THE FRONT AT THIS TIME...LOW STRATUS AND FOG WAS DEVELOPING INTO NORTHWEST AND NORTH CENTRAL IL...AND WILL LIKELY LINGER AFTER SUNRISE THIS MORNING. SOMEWHAT DRIER LOW LEVEL AIR WILL FILTER IN FROM THE NORTH BY TONIGHT AS HIGH PRESSURE SPREADS ACROSS THE NORTHERN GREAT LAKES REGION...AND THE FRONT MOVES INTO DOWNSTATE IL/IN. GUIDANCE IS IN GOOD AGREEMENT IN DIGGING ANOTHER SHORT WAVE ACROSS THE MIDWEST WEDNESDAY INTO THURSDAY HOWEVER...WITH OVERRUNNING OF THE LOW LEVEL FRONTAL ZONE DEVELOPING FROM NORTHWEST IOWA INTO CENTRAL ILLINOIS. MODEL TREND HAS BEEN TO DEVELOP FAIRLY STRONG FRONTOGENESIS ALONG THE ELEVATED BAROCLINIC ZONE BENEATH THE RIGHT ENTRANCE REGION OF A 90 KT UPPER JET STREAK THROUGH THURSDAY...BRINGING A COUPLE OF PERIODS OF RAIN AND THUNDERSTORMS BACK INTO THE FORECAST AREA FROM WEDNESDAY MORNING THROUGH THURSDAY NIGHT. THE POTENTIAL EXISTS FOR SOME LOCALLY HEAVY RAINFALL THURSDAY/THURSDAY NIGHT ACROSS SOUTHERN PARTS OF THE CWA...AS 2+ INCH PWATS SPREAD NORTH. GFS/WRF BOTH DELIVER MORE THAN AN INCH OF RAIN TO THE SOUTHERN CWA DURING THIS TIME. FRONTAL ZONE THEN SHIFTS SOUTH INTO THE OHIO VALLEY AS HIGH PRESSURE STRENGTHENS ACROSS THE NORTHERN GREAT LAKES REGION FRIDAY AND SATURDAY. EASTERLY LOW LEVEL FLOW AROUND THE HIGH FAVORS DRY WEATHER AND PREFER THE DRIER ECMWF SOLUTION FOR THIS PERIOD. ANOTHER UPPER TROUGH APPROACHES THE REGION BY MONDAY HOWEVER...WITH AN INCREASE IN RAIN CHANCES LATER SUNDAY INTO MONDAY. TEMPERATURES THROUGH THE FORECAST PERIOD WILL AVERAGE JUST A BIT BELOW NORMAL WITH THE COOLEST DAYS WEDNESDAY-THURSDAY REMAINING IN THE 70S. OTHERWISE AROUND 80/LOWER 80S APPEAR REASONABLE. SURFACE FLOW WILL BE OFF THE LAKE THROUGH MOST OF THE PERIOD KEEPING AREAS NEAR LAKE MICHIGAN A LITTLE COOLER. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * NORTHEAST WINDS INCREASING TO AROUND 10KT DURING THE MID- AFTERNOON. * TEMPORARY MVFR CIGS POSSIBLE EARLY THIS AFTERNOON. * FOG POSSIBLE AGAIN TONIGHT...MAINLY MVFR. * NORTHEAST WINDS AROUND 10 KT AGAIN WEDNESDAY AFTERNOON. //DISCUSSION...UPDATED 18Z... A VERY SLOW MOVING COOL FRONT IS DRAPED FROM NEAR STL TO GYY TO DET. LOW-LEVEL MOISTURE POOLED ALONG THIS WAS RESPONSIBLE FOR THE MORNING FOG AND LOW CLOUDS...WITH THE LATTER STILL CONTINUING AT A FEW AIRPORTS EARLY THIS AFTERNOON. CEILINGS SHOULD CONTINUE TO SLOWLY LIFT AND EVEN SCATTER BY LATER IN THE DAY. BEHIND THE FRONT...WINDS SLOWLY INCREASE FROM THE NORTHEAST. AN INCREASE IN WIND SPEEDS UP TO AROUND 10 KT CONTINUES TO BE ANTICIPATED AT CHICAGOLAND TAF SITES...HELPED BY A MESOSCALE INCREASE ALONG THE PERIPHERY OF THE LAKE AND A SYNOPTIC NORTHEAST PUSH. WINDS SHOULD DIMINISH IN SPEED TONIGHT AND THEN INCREASE AGAIN TUESDAY LATE MORNING INTO THE AFTERNOON. ANY PRECIPITATION CHANCES LOOK TO REMAIN SOUTH OF THE TAF SITES. LOW CLOUDS AND SOME FOG ARE A POSSIBILITY AGAIN TONIGHT...MAINLY AWAY FROM THE METRO AREA. TEMPERATURE/DEW POINT SPREADS ARE LOW FOR MIDDAY DUE TO THE HIGH MOISTURE AND COOLER TEMPERATURES...SETTING THE STAGE FOR THIS AFTER DARK. CONFIDENCE IS LOW ON THIS AT THIS TIME. //ORD AND MDW CONFIDENCE...UPDATED 18Z... * MEDIUM THAT WIND SPEEDS WILL INCREASE TO 10 KT BY 21Z. * HIGH THAT CIGS WILL REMAIN ABOVE 1500 FT. * LOW IN MVFR FOG DEVELOPING TONIGHT. * MEDIUM IN WIND SPEEDS AND TIMING OF 10 KT ON WEDNESDAY. //OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z... WEDNESDAY NIGHT...VFR. THURSDAY...SLIGHT CHANCE OF TSRA. FRIDAY...VFR. SATURDAY...VFR. SUNDAY...SLIGHT CHANCE OF TSRA. MONDAY...CHANCE OF TSRA. MTF/RODRIGUEZ && .MARINE... 206 PM CDT WEAK FLOW IS OVER THE REGION AND THE COLD FRONT IS SOUTH OF THE LAKE. NORTH TO NORTHEAST WINDS 10-20 KT ARE EXPECTED THROUGH THIS AFTERNOON AND THEN WINDS WILL SLOWLY DIMINISH TO AROUND 10 KT BY WEDNESDAY MORNING. WINDS INCREASE TO 10-20 KT TOMORROW AFTERNOON. THE HIGH SHIFTS EAST OF THE LAKE THURSDAY WITH WINDS BECOMING EAST. WINDS REMAIN EAST AT OR BELOW 15 KT THROUGH THE END OF THE WEEK. GUIDANCE DIFFERS ON WHEN THE NEXT LOW WILL IMPACT THE AREA EARLY NEXT WEEK...BUT IN GENERAL WEAK FLOW CONTINUES WITH NO MAJOR IMPACTS EXPECTED. JEE && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 1257 PM CDT Tue Aug 5 2014 .UPDATE... ISSUED AT 1030 AM CDT TUE AUG 5 2014 Will update the forecast today to adjust sky cover with more low clouds from Peoria north today and cooler highs in the lower 80s. Will continue 20-30% chances of showers and thunderstorms over eastern IL this afternoon. Seasonably warm highs in the mid 80s over much of CWA with upper 80s near Lawrenceville and Robinson by Wabash river valley. Rather humid today with dewpoints in the mid 60s to near 70F with lowest dewpoints in southeast IL. Short wave that brought locally heavy rains of 1.5-3.5 inches around the Peoria metro area last night has shifted east and south of central IL late this morning. Showers and isolated thunderstorms have exited southeast IL during mid morning so by late morning ILX CWA is dry. Low clouds of 500-1200 feet from Peoria north while patches of clouds above 3k ft over eastern IL from I-57 east. 10 am temps range from near 70F far ne CWA by Lacon and Danville where clouds prevail, to upper 70s from Springfield sw where more sunshine this morning. Dewpoints range from mid 60s over eastern IL to near 70F from Macomb to Springfield west. A frontal boundary just se of the IL river will continue to press slowly se into southeast IL later today. Even though we are on back side of short wave exiting se of IL today, the boundary could develop isolated convection this afternoon as it pushes through areas se of I-55. SPC has 5% risk of severe storms this afternoon and into tonight over Nebraska and western IA and then has 5% risk of severe hail/wind over central IL Wed afternoon/evening and slight chance of severe storms (15% of large hail and damaging wind gusts) sw of a Canton to Lincoln line. HUETTL && .SHORT TERM...Today through Thursday Scattered showers associated with a short-wave trough will continue to work their way east/southeast across the KILX CWA early this morning. Most of the precip will be east of the I-55 corridor by 12z, then into Indiana by 18z as trough passes to the east. Subsidence on the back side of the wave should lead to a mostly dry afternoon, although HRRR is hinting that a few additional showers may fire across the E/NE during the afternoon. Will go with isolated to scattered wording for today, as areal coverage will be rather limited. Morning clouds will gradually clear, with partly sunny conditions expected later in the day. Will be another warm/humid day with highs once again reaching the middle 80s. A lull in the precip chances will occur this afternoon through the evening as short-wave ridging prevails. The next in a series of waves will begin to approach from the northwest overnight, with all model solutions showing a large area of showers/thunder developing along/north of a stalled frontal boundary draped across Iowa. Precip will begin to push into the Illinois River Valley toward dawn Wednesday, so will carry low chance PoPs after midnight along/northwest of the Illinois River with dry conditions elsewhere. Showers and thunderstorms will spread across much of central Illinois on Wednesday, primarily impacting locations west of the I-57 corridor. Will carry likely PoPs across the west, tapering down to low chance along the Indiana border accordingly. SPC has indicated that a slight risk for severe storms may develop Wednesday afternoon and evening across northern Missouri into southwest Illinois. This severe risk is contingent upon vigorous short-wave currently over Utah maintaining its strength as it approaches from the west Wednesday evening. NAM remains most aggressive with this feature, while GFS is quite a bit weaker. If stronger NAM verifies, enough lift will be generated along/south of surface boundary within the unstable and moderately sheared airmass to support a few strong to severe storms with large hail/gusty winds across the southwest CWA Wednesday evening. Otherwise, expect showers and thunderstorms to become more numerous across the entire area Wednesday night into Thursday as upper wave tracks across the area and interacts with the stalled frontal boundary and very moist airmass. .LONG TERM...Friday through Monday Once the Thursday wave passes to the east, frontal boundary will begin to get pushed southward by the end of the week. Models continue to struggle with this evolution, but general consensus shifts best precip chances into the Ohio River Valley on Friday, then even further south over the weekend. As a result, will focus chance PoPs across only the southern CWA on Friday. After that, Saturday and Sunday appear to be largely dry before the next potential wave approaches within the prevailing northwesterly flow pattern early next week. Will therefore go with a dry forecast during the weekend, with low chance PoPs returning by Monday. BARNES && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Wednesday AFTERNOON) ISSUED AT 1255 PM CDT TUE AUG 5 2014 MVFR ceilings to occur over central IL airports next few hours and gradaully lift to VFR ceilings or even scattered out especially at SPI and DEC. A frontal boundary near I-72 will slowly move into southeast IL later this afternoon. Isolated showers and thunderstorms to occur over east central and se IL this afternoon with CMI and DEC having best chances of seeing this, but feel chances are too low to even mention VCTS. Another short wave diving se into IL late tonight and Wed to likely return chances of showers and thunderstorms starting at PIA at 10Z along I-55 from 11z-12Z and DEC and CMI from 13-14Z. Have MVFR ceilings and vsbys arriving by Wed morning with the rain and some fog also possible. West winds near 5 kts along I-72 to turn NE early this afternoon as front slips south of I-72. Expect NE winds to remain light tonight and near 5 kts Wed morning. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...HUETTL LONG TERM...BARNES AVIATION...HUETTL
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
100 PM EDT TUE AUG 5 2014 .UPDATE... AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 359 AM EDT TUE AUG 5 2014 A COLD FRONT MOVING INTO THE AREA WILL BRING CHANCES FOR THUNDERSTORMS TO CENTRAL INDIANA TODAY. THIS FRONT WILL STALL SOMEWHERE IN THE AREA AND UPPER WAVES WILL INTERACT WITH IT THROUGH THE REST OF THE WEEK KEEPING THUNDERSTORM CHANCES IN THE FORECAST. NEAR NORMAL TEMPERATURES WILL TAKE A SMALL DIP IN THE WAKE OF THE COLD FRONTAL PASSAGE WEDNESDAY AND THURSDAY BEFORE REBOUNDING TO NORMAL FROM THURSDAY ON. && .NEAR TERM /REST OF TODAY/... ISSUED AT 929 AM EDT TUE AUG 5 2014 UPPED POPS TO LIKELY IN THE EXTREME WEST THIS MORNING BASED ON CURRENT RADAR TRENDS AND UPPED THEM TO HIGH END OF CHANCE CATEGORY FOR MUCH OF THE REMAINDER OF THE WEST. RAIN IS GENERALLY DIMINISHING AS IT MOVES EAST SO KEPT LOWER POPS EAST. AS UPPER WAVE MOVES EAST LATER THIS MORNING SUPPORT FOR CONVECTION WEAKENS...AND LATEST HI RES MODELS ARE SHOWING LITTLE DEVELOPMENT THIS AFTERNOON. HOWEVER STILL THINK POTENTIAL IS THERE FOR SCATTERED DEVELOPMENT WITH THE EXPECTED AFTERNOON INSTABILITY. THUS GENERALLY KEPT POPS THE SAME THIS AFTERNOON...BUT LOWERED JUST A BIT FROM THE HIGH END CHANCE CATEGORY NORTHEAST DUE TO THE WEAKER SUPPORT. PREVIOUS DISCUSSION FOLLOWS... RADAR MOSAIC SHOWS SHOWERS AND THUNDERSTORMS MOVING INTO THE NORTHWESTERN COUNTIES BUT SHRINKING AS THEY DO. THESE WILL SLOWLY MOVE IN BUT COVERAGE WILL BE LESS AND LESS BASED ON CURRENT TRENDS. THUS KEPT POPS AT CHANCE/SCATTERED OR LESS FOR THE REST OF THE EARLY MORNING. AFTER THAT SHORT TERM MODELS ARE SHOWING EVEN LESS COVERAGE BUT PERHAPS AN INCREASE AGAIN IN THE AFTERNOON. TRIED TO TIME THE POPS FOR THE TODAY PERIOD WITH THE MOVEMENT OF THE UPPER WAVE AND KEPT THE HIGHEST POPS ACROSS THE NORTH. BROUGHT A SLIGHT CHANCE IN ACROSS THE SOUTH FOR THE AFTERNOON INSTEAD OF KEEPING THINGS DRY WITH RAP SHOWING SOME DEVELOPMENT THERE AS WELL BUT THE BEST FORCING STAYING FAR FROM THERE. FOR TEMPERATURES THOUGHT THE CONSENSUS NUMBERS DID A GOOD JOB. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/... ISSUED AT 359 AM EDT TUE AUG 5 2014 FOR TONIGHT CONTINUED WITH SOME POPS AS A CARRYOVER FROM TODAY AS THE UPPER WAVE WILL BE MOVING OUT. BY LATE TONIGHT WENT DRY WITH LITTLE FORCING PRESENT. FOR WEDNESDAY MODELS HAVE TRENDED DRIER THIS RUN. NOT READY TO BUY THIS FULL ON SINCE LAST NIGHT/S RUNS HAD WEDNESDAY LOOKING FAIRLY WET. THUS BLENDED PREVIOUS AND CURRENT SOLUTIONS TO PROVIDE A COMPROMISE OF LOW CHANCE POPS ACROSS THE AREA. THE BEST FORCING WILL NOT BE ARRIVING UNTIL VERY LATE WEDNESDAY NIGHT INTO THURSDAY WITH A SHORTWAVE PROVIDING ADDITIONAL FORCING TO THE FRONT WHOSE EXACT POSITION IS STILL VARIABLE BETWEEN MODELS AND RUN-TO-RUN. WENT WITH THE HIGHEST POPS IN THE PERIOD ON THURSDAY WITH THE FORCING FROM THE UPPER WAVE. IF THE SURFACE FRONT SETS UP JUST TO THE SOUTH OR RIGHT ACROSS THE AREA HEAVY RAIN COULD BE A PROBLEM...BUT AT THIS POINT THE EXACT LOCATION OF THAT FRONT IS STILL VERY LOW CONFIDENCE. FOR TEMPERATURES THROUGH THE PERIOD GENERALLY USED A CONSENSUS. FOR THURSDAY/S HIGHS THOUGH WENT LOWER THAN THE MODEL AVERAGE TO REFLECT THE POTENTIAL FOR COOLER TEMPERATURES WITH THE HIGHER PROBABILITY FOR CLOUD COVER AND RAIN. && .LONG TERM /FRIDAY THROUGH MONDAY/... ISSUED AT 359 AM EDT TUE AUG 5 2014 THE THREAT FOR UNSETTLED WEATHER IS LIKELY TO PERSIST INTO THE WEEKEND AS NORTHWEST FLOW ALOFT REMAINS ACROSS THE REGION AND A FRONTAL BOUNDARY ALIGNS OVER THE TENNESSEE AND LOWER OHIO VALLEYS. 00Z MODEL SUITE HAS SHIFTED THE FRONT FURTHER NORTH FROM PREVIOUS RUNS...ESPECIALLY THE ECMWF AND OP GFS WHICH BOTH HAD MAINTAINED A MORE SUPPRESSED LOCATION TO THE BOUNDARY. DIFFERENCES REMAIN HOWEVER WITH RESPECT TO EVENTUAL LOCATION OF THE BOUNDARY BUT WITH A GENERAL CONSENSUS NOW PLACING IT JUST SOUTH OF THE REGION...CARRYING PRECIP CHANCES REMAINS WARRANTED INTO THE FIRST HALF OF THE WEEKEND. WILL PLACE HIGHEST POPS FRIDAY INTO EARLY SATURDAY OVER SOUTHERN COUNTIES AS A SURFACE WAVE RIDES ALONG THE BOUNDARY. WITH A DEEP MOIST AIRMASS IN PLACE FRIDAY/SATURDAY...HEAVY RAIN IS LIKELY TO ACCOMPANY STORMS. DRIER AIR ATTEMPTS TO MAKE A BRIEF APPEARANCE SATURDAY NIGHT WITH HIGH PRESSURE OVER THE NORTHERN GREAT LAKES...BUT THE ARRIVAL OF ADDITIONAL WAVES ALOFT AND THE REMNANT BOUNDARY LINGERING IN THE OHIO VALLEY SUPPORTS REINTRODUCING POPS INTO EARLY NEXT WEEK. TEMPERATURES WILL REMAIN SEASONABLE BUT CONTINUE TO RUN SLIGHTLY BELOW NORMAL THROUGH THE EXTENDED...WITH HIGHS RANGING FROM THE UPPER 70S TO MIDDLE 80S. && .AVIATION /DISCUSSION FOR 051800Z TAF ISSUANCE/... ISSUED AT 100 PM EDT TUE AUG 5 2014 MOSTLY VFR THROUGH THE PERIOD. ALTHOUGH A PERIOD OF MVFR CEILINGS AND FOG NOT OUT OF THE QUESTION LATE TONIGHT AND EARLY WEDNESDAY. A WEAK COLD FRONT OVER NORTHERN INDIANA WILL DRIFT SOUTH ACROSS OUR REGION TONIGHT AND TO NEAR THE OHIO RIVER WEDNESDAY. HIGH PRESSURE WILL BUILD INTO THE GREAT LAKES WEDNESDAY. WEATHER DEPICTION INDICATES AREAS OF MVFR CEILINGS ASSOCIATED WITH THE COLD FRONT OVER NORTHERN ILLINOIS AND SOUTHERN GREAT LAKES. HOWEVER MODEL SOUNDINGS DO NOT INDICATE THIS WILL SPREAD INTO OUR REGION TONIGHT. NERVELESS I WOULD NOT RULE OUT THAT THESE CEILINGS WILL SPREAD INTO OUR REGION. FOR NOW WILL BRING IN 2 THOUSAND SCATTERED WITH MVFR FOG LATE TONIGHT. ON WEDNESDAY EXPECT VFR CONDITIONS FROM MID MORNING ON. A WIDELY SCATTERED THUNDERSHOWER POSSIBLE THROUGH THIS EVENING AND AGAIN WEDNESDAY...BUT CHANCE OF OCCURRENCE TOO LOW TO EVEN MENTION VCTS IN TAFS. WEST OR SOUTHWEST WINDS AROUND 6 KNOTS WILL BECOME LIGHT TONIGHT AND NORTH TO NORTHWEST UP TO 8 KNOTS WEDNESDAY. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...CP NEAR TERM...CP/50 SHORT TERM...CP LONG TERM....RYAN AVIATION...JH VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSINDIANAPOLIS WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
311 PM CDT Tue Aug 5 2014 ...Updated Short Term section... .SHORT TERM...(This evening through Wednesday) ISSUED AT 309 PM CDT TUE AUG 5 2014 The primary focus will be convection this evening and how expansive it will be this evening across western Kansas. Water vapor loop early this afternoon showed a substantial mid level dry intrusion into the southwestern CONUS which was pushing northeastward through Colorado. RAP analysis revealed a fairly perturbed middle troposphere from the primary vorticity anomaly across central/northern California...eastward through Utah and into Colorado. A 250mb jet streak continued to nose northeastward into southern California through southern Utah. A lee trough convergence axis was found across far southeastern Colorado into far northwestern Kansas. This was on the western periphery of deep mid level moisture plume. All the short-term high resolution models suggest convection continuing to develop along the lee trough convergence axis and also over terrain-favored regions of Colorado. There is the suggestion that the most organized of lee trough convection will stay just north of the DDC forecast area from far west-central KS into northwestern KS. Both the 12Z WRF ARW and NMMB show a cluster of pseudo-organized convection rolling east-southeast reaching roughly a Leoti to Gove line by around 06Z. The best of the lee trough convergence will be farther north, so it would make sense that the high resolution models are keeping the most sustained convection across northwestern Kansas. Other less organized convection farther south may last through sunset, but not much after that. We will keep Chance POPs confined to far west-central KS (Kearny to Scott County). South winds tonight averaging 12 to 15 knots will keep the boundary layer mixed enough through the night that temperatures will likely plateau during the 06-12Z time frame in the lower 70s along/east of Highway 283. The trough axis will shift east Wednesday with lighter winds much of the day across much of southwest Kansas. Weak convergence along the trough may yield late afternoon convection, but only loosely organized convection at best can be expected with the deep frontogenetic forcing still north of the southwest Kansas region through late afternoon Wednesday. .LONG TERM...(Wednesday night through Tuesday) ISSUED AT 246 PM CDT TUE AUG 5 2014 No significant changes were made to the extended period of the forecast. Wednesday night, and through the overnight into Thursday morning will present chances for convection along a weak boundary and area of surface low pressure over western Kansas. The model signals for this suggest the best chances for isolated to scattered thunderstorms will be across central Kansas where instability and CAPE will be greater. Any storms along this convergence zone should end by Thursday morning across the south central Kansas counties rendering Thursday dry for most of the day. Convection will again be possible in the far west on Thursday evening and through the night as it forms diurnally along the high terrain of eastern Colorado with the aid of upslope surface flow and higher dew points around 60 degrees or more. Beyond Friday, the region will remain in a fairly westerly zonal pattern but also not a particularly strong surface gradient, leading to relatively light winds. As the region will remain fairly rich ion surface moisture and warm, any local areas of uncapped convergence could set off afternoon convection lasting into the very early evening through about Tuesday. However chances as far as areal coverage are concerned should be fairly minimal. && .AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon) ISSUED AT 1202 PM CDT TUE AUG 5 2014 South winds will remain fairly strong through the afternoon, averaging 18 to 22 knots sustained through early evening before decreasing to around 12 to 15 knots later this evening. A fairly strong pressure gradient by summer standards will persist through the night, keeping surface winds up around 15 knots at HYS and DDC. The latest indications from high-resolution short term models is that loosely organized thunderstorms late this afternoon/evening will move slowly through west-central Kansas during the mid to late evening hours, but weaken or dissolve entirely late tonight. It does not seem likely that convection will impact any of the terminals, except perhaps GCK (being farther west). && .PRELIMINARY POINT TEMPS/POPS... DDC 69 94 67 92 / 10 20 20 10 GCK 67 94 66 92 / 20 20 20 10 EHA 67 94 66 95 / 20 10 10 20 LBL 69 95 68 97 / 10 20 20 10 HYS 70 96 67 93 / 30 20 30 10 P28 71 94 70 95 / 10 20 30 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Umscheid LONG TERM...Russell AVIATION...Umscheid
AREA FORECAST DISCUSSION
NWS GAYLORD MI
110 PM EDT TUE AUG 5 2014 .SYNOPSIS... ISSUED AT 357 AM EDT TUE AUG 5 2014 ISOLATED SHOWERS AND THUNDERSTORMS ARE AGAIN POSSIBLE IN INTERIOR AREAS OF NORTHERN LOWER MICHIGAN THIS AFTERNOON AND EVENING. HIGH PRESSURE WILL THEN SETTLE IN OVER THE GREAT LAKES REGION WEDNESDAY. THIS HIGH PRESSURE WILL REMAIN IN CONTROL OF THE WEATHER THROUGH THE UPCOMING WEEKEND. TEMPERATURES WILL BE IN THE 70S TO LOWER 80S EACH DAY WITH LOWS GENERALLY IN THE 50S. && .UPDATE... ISSUED AT 1024 AM EDT TUE AUG 5 2014 A NICE EARLY AUGUST DAY UNFOLDING ACROSS THE AREA...WITH THE PASSAGE OF A SHORTWAVE TROUGH BRINGING AN END TO LINGERING SHOWERS DOWN TOWARD THE M-55 CORRIDOR. SOME PESKY LINGERING MID LEVEL MOISTURE WILL LIKELY MILL AROUND DOWN THAT WAY FOR A FEW MORE HOURS WITH BOUTS OF THICKER CLOUD COVER...WHILE AREAS FARTHER NORTH CONTINUE TO SEE LOW/MID LEVEL DRYING WITH THE PASSAGE OF SAID WAVE. THAT SHOULD RESULT IN A GOOD DEAL OF SUNSHINE THROUGH EARLY AFTERNOON...THOUGH WITH THE TYPICAL SUMMERTIME BLOSSOMING OF SOME CUMULUS BENEATH WEAKISH THERMAL TROUGHING STILL IN PLACE. NOT AT ALL CONVINCED WE WILL REALIZE ANY ADDITIONAL SHOWERS LATER THIS AFTERNOON...AS THE BOUNDARY LAYER ALREADY LOOKS A SHADE DRIER THAN YESTERDAY PER 12Z APX RAOB...INDICATIVE OF DEW POINTS LIKELY MIXING OUT BACK THROUGH THE LOWER 50S WHILE AFTERNOON HIGHS REMAIN QUITE SIMILAR TO THOSE OF 24 HOURS AGO. GIVEN LITTLE THERMAL ADVECTION ALOFT THROUGH THE DAY...IT WILL TAKE BETTER MOISTURE POOLING TO JUST SQUEEZE BY THE CAP UP AROUND 600 MB. IF THAT`S GOING TO HAPPEN ANYWHERE IT WILL BE ACROSS THE SOUTHEAST CWA WHERE BETTER LAKE BREEZE CONVERGENCE SHOULD RESIDE OFF LAKE HURON/SAGINAW BAY...BUT EVEN THERE THE CHANCE IS QUITE LOW. HAVE LOWERED POPS INTO THE `ISOLATED` RANGE WHILE ALSO RAISING HIGHS A COUPLE DEGREES FOR MANY AREAS BASED OFF YESTERDAY`S READINGS AND LITTLE CHANGE IN AIRMASS...NOT TO MENTION CURRENT OBS ALREADY WITHIN 5-7 DEGREES OF GOING HIGHS. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 357 AM EDT TUE AUG 5 2014 ...ONE MORE CHANCE FOR SHOWERS AND STORMS... IMPACTS: LIGHTNING THIS AFTERNOON...MAINLY SOUTH OF M-72. CURRENT WEATHER AND SYNOPTIC PATTERN: NO SURPRISE TO THE UPPER LEVEL PATTERN WITH TROUGHING ACROSS THE EASTERN COUNTRY INCLUDING THE GREAT LAKES...AND RIDGING OVER THE WEST. SFC HIGH PRESSURE AND DRIEST AIR WAS DRAPED FROM THE DAKOTAS THROUGH SRN ONTARIO...NOSING INTO EASTERN UPPER. A FRONTAL BOUNDARY WAS NOTED FROM THE EASTERN GREAT LAKES THROUGH SRN LOWER AND INTO WISCONSIN. THERE WAS AN AXIS OF INCREASED H8 MOISTURE AND ELEVATED FRONT STILL HOLDING ACROSS AREAS SOUTH OF M-32...WITH AN INCOMING SHORTWAVE IN NW FLOW ALOFT. THIS HAS RESULTED IN A BAND OF SHOWERS THERE...BUT NO THUNDER THUS FAR. THERE IS JUST A LACK OF INSTABILITY (WHICH REMAINS NEARER THE SFC FRONT IN SRN LOWER). SYNOPTIC PATTERN/WEATHER EVOLUTION: STILL FACING THE SAME PROBLEM WITH THE TODAY/TONIGHT FORECAST. THIS REVOLVES AROUND WHETHER OR NOT WE WILL SEE ANY AFTERNOON AND EVENING SHOWER AND THUNDERSTORM DEVELOPMENT. YESTERDAYS NON-ACTION WAS A LITTLE SURPRISING BUT RESULTED IN A QUICK LOOK BACK AT DATA. THE 00Z APX SOUNDING SHOWED MUCH DRIER AIR BELOW 750MB THAN WHAT WAS SUGGESTED IN YESTERDAYS DATA. MODELS HAVE OVER-FORECASTED BL MOISTURE OVER THE LAST FEW DAYS. LATEST RUC SHOWING A WEDGE OF DRIER H8 AIR SWEEPING DOWN INTO US BEHIND THE SHORTWAVE AND SHOWERS WHICH WILL DEPART BY MID MORNING. THIS WILL BRING A PERIOD OF QUIET NO PRECIP WEATHER. HEATING THROUGH THE DAY WILL ALLOW TEMPS TO MAX OUT HIGHER THAN GUIDANCE (ALSO RUNNING TOO COOL) IN THE MID AND UPPER 70S. FCST BFR SOUNDINGS SHOW INCORRECT INCREASED MOISTURE DEVELOPING AROUND H8 (A FUNCTION OF CONVECTION TAKING OFF IN THE MODELS)...WHAT IS MORE LIKELY IS FOR VERY SHALLOW RIDGING THIS AFTERNOON BEHIND THE WAVE...WITH VERY LITTLE IN THE WAY OF ADVECTION DUE TO CONTINUED LIGHT WINDS. AM EXPECTING THE BL TO MIX OUT DECENTLY AGAIN (BUT CURRENT RAINS WILL ADD TO LOW LEVEL MOISTURE AVAILABILITY). FCST SOUNDINGS SHOW CONTINUED COOLING ALOFT (WHICH SEEMS ODD CONSIDERING THE SHALLOW RIDGING)...AND SFC BASED DEW POINTS (OUTSIDE OF WHERE CURRENT RAIN SHOWERS RESIDE) ARE A COUPLE/FEW DEGREES TOO HIGH. REGARDLESS...EVEN TAKING A FAIRLY DRY PARCEL...MODIFICATION RESULTS IN SNEAKING BY A WEAK CAP ALOFT AROUND 600MB. 400-800 J/KG ARE SEEN IN INTERIOR NRN LOWER (WHERE LAKE BREEZE CONVERGENCE WILL MAXIMIZE). CAN SEE ISOLATED TO SCATTERED SHOWERS AND A FEW STORMS FIRING OFF...WITH NOTHING IN THE LAKE BREEZE CONVERGENCE IN MACKINAC COUNTY DUE TO TOO DRY OF AIR. THESE SHOWERS WILL LIKELY FADE OFF THROUGH EVENING...BUT WILL HAVE TO WATCH NEXT INCOMING SHORTWAVE FROM ONTARIO LATER TONIGHT. THERE MAY BE AN OUTSIDE CHANCE THAT A FEW OF THESE SHOWERS MAY BE ABLE TO CONTINUE INTO THE NIGHT...BUT CONFIDENCE IN THAT IS RATHER LOW. WILL END ALL SHOWERS BY MID/LATE EVENING. && .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 357 AM EDT TUE AUG 5 2014 ...QUIET THROUGH THE WEEKEND... OVERVIEW...THE BASICS OF THE PATTERN ARE GOING TO MOVE WITH THEM ONLY REESTABLISHING THEMSELVES BY NEXT WEEK. SO THE MAIN IDEA WILL BE THAT THE RIDGE IN THE WEST WILL MIGRATE EAST INTO THE UPPER GREAT LAKES. THIS WILL PRODUCE MAINLY DRY WEATHER THROUGH THE WEEKEND. THEN THE CHANCE OF SHOWERS AND THUNDERSTORMS MONDAY. SO WITH THAT IN MIND THE FORECAST LOOKS LIKE THIS... (8/6)WEDNESDAY AND (8/7)THURSDAY...THE SFC HIGH BUILDS OVER THE REGION WEDNESDAY AS A 500 MB SHORTWAVE TROUGH MOVES THROUGH THE REGION WITH FAIRLY DRY AIR (700-500 MB LAYER RH <30% AND 850 MB RH <50%). THIS LEAVES THE REGION RAIN FREE. THE SAME CONDITIONS ARE EXPECTED TO REMAIN OVER THE UPPER GREAT LAKES AS THE RIDGING TAKES PLACE THROUGH THE LOWER AND MID LEVELS. EXTENDED (FRIDAY THROUGH MONDAY)...THE RIDGING IS EXPECTED TO REMAIN FRIDAY AND SATURDAY AS WELL, AT LEAST ON THE ECMWF. THE GFS TRIES TO RAM RAIN NORTH INTO THE SW COUNTIES LATE ON SATURDAY AS SOME SHORTWAVE DIGS INTO THE 500 MB RIDGE. HOWEVER, THINK THAT THE ECMWF IS THE BETTER OF THE TWO MODELS AS THE 500MB RIDGING SHOULD REMAIN STRONG ENOUGH TO SHUNT THE SHORTWAVE NORTH. IT NOT UNTIL (8/10)SUNDAY THAT WE BEGIN TO GET A CHANGE FOR SOMETHING ORGANIZED. WHILE THE DAY AND NIGHT STILL REMAIN DRY, A 500 MB TROUGH AND SFC COLD FRONT BEGINS TO MARCH INTO THE UPPER GREAT LAKES, LATE ON SUNDAY NIGHT. THE MODELS ARE BEGINNING TO PUSH THE FRONT THROUGH ON MONDAY OR MONDAY NIGHT. THE ECMWF IS THE FASTER OF THE TWO MODELS, IN THIS CASE. SO WILL CONTINUE THE MONDAY POPS AND CONTINUE THEM INTO MONDAY NIGHT AS THE BOTH THE ECWMF AND THE GFS HAVE THE FRONT OVER THE FORECAST AREA OVERNIGHT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 110 PM EDT TUE AUG 5 2014 PREDOMINANTLY VFR THROUGH THE PERIOD AS HIGH PRESSURE WORKS TOWARD NORTHERN MICHIGAN. A THICKER PERIOD OF CUMULUS CLOUDS IS EXPECTED AROUND KAPN UP THROUGH ABOUT 19Z...WITH A BRIEF PERIOD OF MVFR CEILINGS POSSIBLE BEFORE THINGS SCATTER OUT WITH TIME. SKIES SHOULD BE CLEAR EVERYWHERE OVERNIGHT WITH PERHAPS A LITTLE SHALLOW GROUND/RIVER VALLEY FOG DEVELOPING IN SPOTS...MOST PRONOUNCED AROUND THE KMBL TERMINAL. CLEAR SKIES ARE THEN EXPECTED TO RETURN FOR WEDNESDAY. WINDS WILL REMAIN UNDER 10 KNOTS THROUGH THE PERIOD. && .MARINE... ISSUED AT 357 AM EDT TUE AUG 5 2014 NO WIND AND WAVE ISSUES TO BE CONCERNED WITH FOR SEVERAL DAYS...LIKELY THROUGH THE UPCOMING WEEKEND. HIGH PRESSURE TAKES CONTROL OF THE WEATHER WEDNESDAY ONWARD...WITH DRY AIR AND AFTERNOON LAKE BREEZES. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...NONE. LM...NONE. LS...NONE. && $$ UPDATE...LAWRENCE SYNOPSIS...JL SHORT TERM...SMD LONG TERM...JL AVIATION...LAWRENCE MARINE...SMD
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
342 PM CDT TUE AUG 5 2014 .SHORT TERM...(TONIGHT THROUGH FRIDAY) ISSUED AT 315 PM CDT TUE AUG 5 2014 MAIN FORECAST CHALLENGE WILL BE PCPN CHANCES/TIMING OVER THE NEXT SEVERAL DAYS. SURFACE LOW PRESSURE IS CURRENTLY LOCATED OVER SOUTHWEST NEBRASKA/NORTHWEST KANSAS WITH A WARM FRONT EXTENDING EASTWARD FROM THE LOW CENTER ACROSS SOUTHERN NEBRASKA. UPPER LEVEL RIDGE AXIS CONTINUES TO FLATTEN AND MOVE OVERHEAD WITH SEVERAL EMBEDDED SHORTWAVE TROUGHS MOVING THROUGH THE FLOW. SOME CONVECTION IS ALREADY ONGOING ACROSS WESTERN/CENTRAL PORTIONS OF NEBRASKA THIS AFTERNOON WITHIN STRONG UPSLOPE FLOW. THESE MAY CONTINUE TO SPREAD EAST INTO OUR FAR NORTHWESTERN COUNTIES LATE THIS AFTERNOON/EARLY THIS EVENING AS BOTH THE HRRR AND RAP HAVE BEEN INDICATING. BETTER FORCING FOR ASCENT WILL ENTER INTO THE REGION LATER TONIGHT AS A PIECE OF SHORTWAVE ENERGY TOPS THE FLATTENING RIDGE. THIS COMBINED WITH STRONG ISENTROPIC UPGLIDE NEAR THE 315K SURFACE AND PW`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
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1232 PM CDT TUE AUG 5 2014 .UPDATE... ISSUED AT 1041 AM CDT TUE AUG 5 2014 SURE ENOUGH A MID-LVL SHWR HAS BRIEFLY DEVELOPED AND PULSED UP NEAR NORTON KS /NRN/ BUT IT IS ALREADY FADING. HAVE INTRODUCED A 20% POP S AND W OF THE TRI-CITIES FROM NOW THRU EARLY AFTERNOON TO ACCT FOR WHAT COULD BE JUST SOME BRIEF SPRINKLES. BUT AN ISOLATED LIGHTNING STRIKE CAN`T BE RULED OUT. UPDATE ISSUED AT 1023 AM CDT TUE AUG 5 2014 BASED ON WHAT HAPPENED WITH DWPTS YESTERDAY SW OF THE TRI-CITIES AND LOOKING AT THIS MORNING`S DDC SOUNDING...DWPTS WERE LOWERED SEVERAL DEGS THIS AFTERNOON/EVENING. WE WILL UPDATE THE FIRE WX FCST WITH THE LOWER RH LEVELS. UPDATE ISSUED AT 937 AM CDT TUE AUG 5 2014 A COUPLE OF VERY SHORT-TERM UPDATES HAVE BEEN PUBLISHED TO KEEP FCST TEMP/DWPT TRENDS ON TRACK WITH REALITY. ALSO BRUSHED UP CLOUDS THRU 00Z AND POPS WERE SCALED BACK THRU 19Z. WE HAVE NOTED THE HRRR ENSEMBLE AND THE NAM/GFS TRY TO DEVELOP A SHWR OR TSTM THIS MORNING IN THE MCK REGION AND POSSIBLY NORTHEASTWARD. THE FIRST FEW VIS SAT PICS DO SHOW SOME CU AND/OR ACCAS. WE WILL CONT TO MONITOR THIS AND MAY NEED TO AMEND THE FCST AS IT IS CURRENTLY DRY S AND W OF THE TRI-CITIES. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 325 AM CDT TUE AUG 5 2014 REGIONAL RADAR SHOWS SOME THUNDERSTORMS ACROSS SOUTHERN SOUTH DAKOTA AND NORTHERN NEBRASKA. THESE HAVE BEEN MOVING EAST OR SOUTHEAST. SURFACE OBSERVATIONS SHOW THAT SOME LIGHT FOG HAS FORMED IN SPOTS BUT SO FAR THE VISIBILITIES HAVE ONLY BEEN 3 TO 5 MILES. THE FIRST CONCERNS WILL BE WHETHER THE THUNDERSTORMS TO THE NORTH WILL GET INTO THE AREA THIS MORNING AND IF THE FOG WILL HAVE AN IMPACT ON VISIBILITY BY MORNING. WITH THE CURRENT MOVEMENT EXPECT THAT THE MAJORITY OF THE THUNDERSTORMS WILL REMAIN NORTH OF THE AREA BUT HAVE KEPT SOME LOW POPS IN THE FAR NORTH OR NORTHEAST. SO FAR THE VISIBILITY HAS BEEN ABOVE 3 MILES. WINDS ARE A LITTLE STRONGER THAN THEY WERE LAST NIGHT. THE LATEST HRRR CONTINUES TO SHOW LOWER VISIBILITY IN THE FAR NORTHEAST. WILL KEEP SOME PATCHY FOG IN FOR EARLY THIS MORNING. AN UPPER LEVEL WAVE APPROACHES THE AREA THIS AFTERNOON. A SURFACE LOW DEVELOPING ON THE HIGH PLAINS WILL MOVE INTO THE AREA DURING THE DAY. AS THE UPPER LEVEL WAVE MOVES INTO THE AREA...THUNDERSTORMS ARE EXPECTED TO FORM NEAR THE SURFACE LOW AND A SURFACE BOUNDARY EXTENDING TO THE EAST AHEAD OF THE SURFACE LOW. EXPECT A FEW OF THE STORMS COULD BE STRONG THIS AFTERNOON AND EVENING WITH GUSTY WINDS AND SOME SMALL HAIL. THE THUNDERSTORMS ARE EXPECTED TO CONTINUE ACROSS THE AREA TONIGHT AS THE UPPER WAVE MOVES THROUGH THE AREA AND THE SURFACE LOW MOVES INTO THE FORECAST AREA. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 325 AM CDT TUE AUG 5 2014 THE WEATHER PATTERN BECOMES MORE UNSETTLED DURING THE EXTENDED PERIODS. BEGINNING ON WEDNESDAY...CONVECTION MAY BE ONGOING FOR THE FIRST PART OF THE DAY AHEAD OF AN ADVANCING COLD FRONTAL BOUNDARY AS AN UPPER LOW PRESSURES SYSTEM TRANSLATES SOUTHEAST FROM THE DAKOTAS. ALSO A 40KT LOWLEVEL JET ORIENTED TOWARDS THE MO RIVER MAY SUSTAIN THE CONVECTION FOR SEVERAL HOURS IN THE MORNING. THIS INITIAL ROUND OF CONVECTION SHOULD DIMINISH WEDNESDAY MORNING WITH REDEVELOPMENT POSSIBLE DURING THE DAY ALONG THE ADVANCING COLD FRONT AND AS THE UPPER WAVE CONTINUES TO TRANSLATE SOUTHEASTWARD. A STRONG TO SEVERE STORM IS POSSIBLE WITH SREF INSTABILITY PROGS AROUND 2500 J/KG AND SHEAR NEAR 30KTS WHICH COULD LEAD TO A FEW STORMS CAPABLE OF PRODUCING LARGE HAIL/DAMAGING WINDS. PRECIPITABLE WATER VALUES ARE ON THE ORDER OF AN INCH AND A HALF AND IF STORMS CAN GO...DECENT RAINFALL AMOUNTS ARE POSSIBLE. THERE ARE SOME MODEL DIFFERENCES ON HOW QUICKLY THE BOUNDARY WILL MOVE THROUGH WEDNESDAY NIGHT WITH THE NAM FASTER THAN THE GFS WITH THE PROGRESSION. AS THE BOUNDARY MOVES THROUGH...PCPN CHANCES DECREASE N/S WITH COOLER AND DRIER AIR ADVECTING IN AS THE SURFACE RIDGE BUILDS SOUTH BEHIND THE BOUNDARY. THE MODEL DIFFERENCES CARRY INTO THURSDAY WITH THERMAL PROGS/TEMP PROFILES ON THE MODELS WITH THE NAM A FEW DEGREES COOLER WITH MID LEVEL TEMPS THAN THE GFS WHILE THE ECMWF IS IN BETWEEN THE TWO. HAVE WENT WITH MORE OF A MODEL BLEND FOR FORECAST HIGHS WITH THE THERMAL GRADIENT ORIENTED NE/SW. AFTER A MAINLY DRY DAY ON THURSDAY...CONVECTION IS EXPECTED TO REDEVELOP THURSDAY NIGHT TO OUR WEST ALONG THE HIGH PLAINS REGION IN UPSLOPE FLOW. THE GFS IS MORE ROBUST WITH THE CONVECTION WORKING EAST SOUTHEASTWARD THURSDAY NIGHT/EARLY FRIDAY THAN OTHER MODELS. DURING THIS TIME FRAME...THE GFS IS ALSO FARTHER NORTH WITH THE WARM FRONTAL BOUNDARY ACROSS KS WHEREAS NAM SUGGESTS THE BOUNDARY WILL BE IN OKLAHOMA. GIVEN THE UNCERTAINTY HAVE WENT WITH INCREASING CLOUD COVER AND KEPT THE BETTER PCPN CHCS IN OUR SW ZONES. FOR THE REMAINDER OF THE WORKWEEK AND INTO THE WEEKEND...THE PATTERN REMAINS UNSETTLED AS A SERIES OF WAVES CROSS THE INTERIOR CONUS AND THE UPPER RIDGE DAMPENS ACROSS THE SOUTHERN PLAINS. THE RIDGE BEGINS TO REBUILD TO THE NORTH AND WEST OVER THE ROCKIES LATE IN THE WEEKEND WITH A MORE AMPLIFIED NORTHWEST FLOW REGIME RETURNING BY DAY 7. CONVECTIVE POTENTIAL WILL BE DEPENDENT UPON TIMING OF WAVES AND FRONTAL BOUNDARY PLACEMENT WHICH WILL BE REFINED WITH TIME BUT THIS BEING SAID...THE WEATHER PATTERN DOES LOOK MORE ACTIVE DURING THE EXTENDED PERIODS WITH MORE PROMISING POTENTIAL FOR RAINFALL. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1232 PM CDT TUE AUG 5 2014 THIS AFTERNOON: VFR WITH BKN CIRROSTRATUS AROUND 20K FT. MID-LEVEL CEILINGS WILL GRADUALLY INCREASE...ESPECIALLY AFTER 21Z WHEN SCT TSTMS DEVELOP TO THE W. SE WINDS WILL OCCASIONALLY GUST TO NEAR 20 KTS. CONFIDENCE: HIGH TONIGHT: VFR WITH A CHANCE OF A VFR OR MVFR TSTM BETWEEN 03Z-09Z. MULTI-LAYERED CLOUD DEBRIS INVADE PRIMARILY ABOVE 10K FT. SE WINDS SUBSIDE TO NEAR 10 KTS. LLWS WILL DEVELOP BY 08Z. CONFIDENCE: MEDIUM WED MORNING: VFR WITH MULTI-LAYERED CEILINGS DEPARTING TO THE E. LLWS ENDS BY 14Z. SE WINDS UNDER 10 KTS. CONFIDENCE: HIGH && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ UPDATE...HALBLAUB SHORT TERM...JCB LONG TERM...FAY AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1226 PM CDT TUE AUG 5 2014 .UPDATE... ISSUED AT 1206 PM CDT TUE AUG 5 2014 A FEW MINOR UPDATES IN THE NEAR TERM...MAINLY TO ACCOUNT FOR CURRENT TD/T/CLOUD TRENDS...BUT OTHERWISE THE FORECAST REMAINS SOLID. STILL ANTICIPATING ADDITIONAL SHOWERS AND STORMS THIS AFTERNOON AND INTO THE EVENING ASSOCIATED WITH AN IMPULSE ROTATING NORTHEAST FROM THE CENTRAL ROCKIES. CURRENTLY FAVORING STORMS THIS AFTERNOON FOCUSING OFF THE HIGHER TERRAIN OF EASTERN WYOMING/COLORADO...WITH THE ACTIVITY MOVING EAST INTO THE CWA EARLY THIS EVENING. OTHER DEVELOPMENT IS POSSIBLE ALONG A WEAK DRY LINE AND/OR NORTH OF THE LIFTING SFC BOUNDARY ACROSS NORTH CENTRAL NEBRASKA. PWATS WILL BE 1.50" OR GREATER OVER MOST LOCATIONS...HEAVY RAINFALL IS POSSIBLE WITHIN STORMS. SOMEWHAT MITIGATING THE SEVERE POTENTIAL WILL BE A RELATIVE MINIMUM IN DEEP SHEAR...BUT SUFFICIENT HEATING WILL INCREASE TROPOSPHERIC INSTABILITY THIS AFTERNOON. IN ADDITION...LOW LEVEL SHEAR WILL BE MAXIMIZED JUST NORTH OF THE LIFTING BOUNDARY...WHICH MAY PROMOTE STORM ROTATION AND A BRIEF HAILER OR DAMAGING DOWNBURST. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 323 AM CDT TUE AUG 5 2014 TODAY AND TONIGHT...MIDLEVEL FRONTOGENESIS WOULD APPEAR TO SHIFT A BIT FARTHER SOUTH INTO NCNTL NEB TODAY ACCORDING TO THE RAP. NONE OF THE OTHER MODELS SHOW THIS BUT GIVEN THE COLD POOL WHICH FORMED IN THE WAKE OF LAST NIGHTS MCS ACROSS SRN SD...THIS WOULD APPEAR LOGICAL. THUS THE FORECAST TODAY AND TONIGHT CARRIES A HIGHER/LIKELY POP IN THE NORTHEAST ZONES WITH SCATTERED TO ISOLD COVERAGE FARTHER SOUTH WHERE THE ATMOSPHERE WILL REMAIN WARMER AND A BIT MORE CAPPED MOST OF THE DAY. H700 MB TEMPERATURES ARE COOL THROUGHOUT THE FCST AREA AT LESS THAN 14C. THE NAM INDICATES THE DISTURBANCE ACROSS SWRN COLORADO WILL MOVE ACROSS THE CNTL SANDHILLS THIS AFTN AND TONIGHT PRODUCING AN ORGANIZED AREA OF CONVECTION IN ADDITION TO THE CONVECTION WHICH WILL LIKELY CONTINUE ALONG AND NORTH OF THE MID LEVEL FRONTOGENESIS. PRECIPITABLE WATER IN THE GFS...NAM AND SREF INCREASE TO 1.5 INCHES OR HIGHER ACROSS ALL OF THE FCST AREA SUPPORTING SCATTERED OR GREATER STORM COVERAGE. THE RAP KEEPS IT AT 1.25 INCHES SOUTH OF THE STALLED FRONT ACROSS NCNTL NEB WITH THE 1.5 INCHES NORTH OF THE FRONT. THE RAP STILL DEVELOPS CONVECTION ACROSS THE SOUTH TODAY ASSOCIATED WITH A SURGE OF DRY AIR MOVING THROUGH THE PANHANDLE AND NERN COLO. A CHECK ON THE SEVERE WEATHER PARAMETERS SHOWS VERY MODEST SEVERE WEATHER POTENTIAL WITH 30 KTS OF BULK EFFECTIVE SHEAR ACROSS THE NORTHEAST AND AROUND 1500 J/KG OF CAPE. AN ISOLATED STORM WOULD SEEM POSSIBLE BUT NOT MUCH MORE IN THIS ENVIRONMENT. K INDICES RISE TO 40C OR GREATER THIS AFTERNOON AHEAD OF THE DRY SURGE AND ACROSS THE NRN ZONES. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 323 AM CDT TUE AUG 5 2014 THE FIRST IN A SERIES OF SHORTWAVES WILL CROSS THE AREA TUESDAY...WITH A COLD FRONT SETTLING SOUTH ACROSS KANSAS IN ITS WAKE ON WEDNESDAY. THE FRONT WILL REMAIN NEARLY STATIONARY THROUGH THE WEEKEND...WITH A SERIES OF SHORTWAVE DISTURBANCES TO PARADE EAST IN ZONAL FLOW ALOFT. THESE WAVES WILL INTERACT WITH A MOISTURE LATENT ATMOSPHERE TO THE NORTH OF THE FRONTAL ZONE ACROSS NEBRASKA...WITH PERIODIC CHANCES FOR SHOWERS/THUNDERSTORMS. THE FLOW ALOFT SHOULD BE STRONG ENOUGH TO PROMOTE SOME STORM ORGANIZATION...AND ONE OR TWO MESOSCALE CONVECTIVE COMPLEXES WILL BE POSSIBLE LATE WEEK INTO THE WEEKEND. PATTERN APPEARS TO SUPPORT THE POTENTIAL FOR SOME MUCH NEEDED RAINFALL ACROSS THE AREA. THE OTHER STORY WILL BE RELATIVELY COOL HIGH TEMPERATURES FOR THIS TIME OF YEAR. THIS SEEMS MOST LIKELY ACROSS NORTHERN NEBRASKA...WHERE HIGHS IN THE MID TO UPPER 70S CAN BE EXPECTED MID WEEK...WARMING TO THE LOW 80S DURING THE WEEKEND. ACROSS THE SOUTHWEST...MOSTLY MID TO UPPER 80S ARE EXPECTED EACH DAY. OVERNIGHT LOWS WILL AVERAGE NEAR NORMAL...IN THE 60S...AS HIGHER RELATIVE HUMIDITY WILL HELP KEEP THE MINIMUM TEMPERATURES MILD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1225 PM CDT TUE AUG 5 2014 VISUAL FLIGHT RULES FOR TERMINALS KLBF AND KVTN THROUGH 21Z. BEYOND 21Z CONVECTION WILL REDEVELOP AS SEVERAL DISTURBANCES MOVE ACROSS MOST LIKELY IMPACTING THE KVTN TERMINAL FIRST...THEN FOCUS SHIFTS SOUTH AND WEST TO BRING A FEW STORMS THROUGH THE KLBF TERMINAL THIS EVENING. THE MODELS ARE IN AGREEMENT WITH DEEPENING BOUNDARY LAYER MOISTURE AGAIN OVERNIGHT THAT SHOULD DROP CEILINGS AND LOWER VISIBILITIES AT BOTH TERMINALS. HOW LOW TO GO IS THE MAIN QUESTION WITH MVFR TO IFR CONDITIONS EXPECTED THROUGH 15Z WEDNESDAY. && .LBF WATCHES/WARNINGS/ADVISORIES...NONE. && $$ UPDATE...JACOBS SHORT TERM...CDC LONG TERM...TAYLOR AVIATION...KECK
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1206 PM CDT TUE AUG 5 2014 .UPDATE... ISSUED AT 1206 PM CDT TUE AUG 5 2014 A FEW MINOR UPDATES IN THE NEAR TERM...MAINLY TO ACCOUNT FOR CURRENT TD/T/CLOUD TRENDS...BUT OTHERWISE THE FORECAST REMAINS SOLID. STILL ANTICIPATING ADDITIONAL SHOWERS AND STORMS THIS AFTERNOON AND INTO THE EVENING ASSOCIATED WITH AN IMPULSE ROTATING NORTHEAST FROM THE CENTRAL ROCKIES. CURRENTLY FAVORING STORMS THIS AFTERNOON FOCUSING OFF THE HIGHER TERRAIN OF EASTERN WYOMING/COLORADO...WITH THE ACTIVITY MOVING EAST INTO THE CWA EARLY THIS EVENING. OTHER DEVELOPMENT IS POSSIBLE ALONG A WEAK DRY LINE AND/OR NORTH OF THE LIFTING SFC BOUNDARY ACROSS NORTH CENTRAL NEBRASKA. PWATS WILL BE 1.50" OR GREATER OVER MOST LOCATIONS...HEAVY RAINFALL IS POSSIBLE WITHIN STORMS. SOMEWHAT MITIGATING THE SEVERE POTENTIAL WILL BE A RELATIVE MINIMUM IN DEEP SHEAR...BUT SUFFICIENT HEATING WILL INCREASE TROPOSPHERIC INSTABILITY THIS AFTERNOON. IN ADDITION...LOW LEVEL SHEAR WILL BE MAXIMIZED JUST NORTH OF THE LIFTING BOUNDARY...WHICH MAY PROMOTE STORM ROTATION AND A BRIEF HAILER OR DAMAGING DOWNBURST. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 323 AM CDT TUE AUG 5 2014 TODAY AND TONIGHT...MIDLEVEL FRONTOGENESIS WOULD APPEAR TO SHIFT A BIT FARTHER SOUTH INTO NCNTL NEB TODAY ACCORDING TO THE RAP. NONE OF THE OTHER MODELS SHOW THIS BUT GIVEN THE COLD POOL WHICH FORMED IN THE WAKE OF LAST NIGHTS MCS ACROSS SRN SD...THIS WOULD APPEAR LOGICAL. THUS THE FORECAST TODAY AND TONIGHT CARRIES A HIGHER/LIKELY POP IN THE NORTHEAST ZONES WITH SCATTERED TO ISOLD COVERAGE FARTHER SOUTH WHERE THE ATMOSPHERE WILL REMAIN WARMER AND A BIT MORE CAPPED MOST OF THE DAY. H700 MB TEMPERATURES ARE COOL THROUGHOUT THE FCST AREA AT LESS THAN 14C. THE NAM INDICATES THE DISTURBANCE ACROSS SWRN COLORADO WILL MOVE ACROSS THE CNTL SANDHILLS THIS AFTN AND TONIGHT PRODUCING AN ORGANIZED AREA OF CONVECTION IN ADDITION TO THE CONVECTION WHICH WILL LIKELY CONTINUE ALONG AND NORTH OF THE MID LEVEL FRONTOGENESIS. PRECIPITABLE WATER IN THE GFS...NAM AND SREF INCREASE TO 1.5 INCHES OR HIGHER ACROSS ALL OF THE FCST AREA SUPPORTING SCATTERED OR GREATER STORM COVERAGE. THE RAP KEEPS IT AT 1.25 INCHES SOUTH OF THE STALLED FRONT ACROSS NCNTL NEB WITH THE 1.5 INCHES NORTH OF THE FRONT. THE RAP STILL DEVELOPS CONVECTION ACROSS THE SOUTH TODAY ASSOCIATED WITH A SURGE OF DRY AIR MOVING THROUGH THE PANHANDLE AND NERN COLO. A CHECK ON THE SEVERE WEATHER PARAMETERS SHOWS VERY MODEST SEVERE WEATHER POTENTIAL WITH 30 KTS OF BULK EFFECTIVE SHEAR ACROSS THE NORTHEAST AND AROUND 1500 J/KG OF CAPE. AN ISOLATED STORM WOULD SEEM POSSIBLE BUT NOT MUCH MORE IN THIS ENVIRONMENT. K INDICES RISE TO 40C OR GREATER THIS AFTERNOON AHEAD OF THE DRY SURGE AND ACROSS THE NRN ZONES. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 323 AM CDT TUE AUG 5 2014 THE FIRST IN A SERIES OF SHORTWAVES WILL CROSS THE AREA TUESDAY...WITH A COLD FRONT SETTLING SOUTH ACROSS KANSAS IN ITS WAKE ON WEDNESDAY. THE FRONT WILL REMAIN NEARLY STATIONARY THROUGH THE WEEKEND...WITH A SERIES OF SHORTWAVE DISTURBANCES TO PARADE EAST IN ZONAL FLOW ALOFT. THESE WAVES WILL INTERACT WITH A MOISTURE LATENT ATMOSPHERE TO THE NORTH OF THE FRONTAL ZONE ACROSS NEBRASKA...WITH PERIODIC CHANCES FOR SHOWERS/THUNDERSTORMS. THE FLOW ALOFT SHOULD BE STRONG ENOUGH TO PROMOTE SOME STORM ORGANIZATION...AND ONE OR TWO MESOSCALE CONVECTIVE COMPLEXES WILL BE POSSIBLE LATE WEEK INTO THE WEEKEND. PATTERN APPEARS TO SUPPORT THE POTENTIAL FOR SOME MUCH NEEDED RAINFALL ACROSS THE AREA. THE OTHER STORY WILL BE RELATIVELY COOL HIGH TEMPERATURES FOR THIS TIME OF YEAR. THIS SEEMS MOST LIKELY ACROSS NORTHERN NEBRASKA...WHERE HIGHS IN THE MID TO UPPER 70S CAN BE EXPECTED MID WEEK...WARMING TO THE LOW 80S DURING THE WEEKEND. ACROSS THE SOUTHWEST...MOSTLY MID TO UPPER 80S ARE EXPECTED EACH DAY. OVERNIGHT LOWS WILL AVERAGE NEAR NORMAL...IN THE 60S...AS HIGHER RELATIVE HUMIDITY WILL HELP KEEP THE MINIMUM TEMPERATURES MILD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 629 AM CDT TUE AUG 5 2014 IFR ACROSS NCNTL NEB THIS MORNING SHOULD GRADUALLY LIFT TO VFR 15Z-18Z. THEREAFTER SCATTERED TSTMS ARE EXPECTED TO DEVELOP 21Z ONWARD...GENERALLY FROM WEST TO EAST. THE STORM ACTIVITY COULD BECOME NUMEROUS THIS EVENING AS THE DISTURBANCE CURRENTLY ACROSS SWRN COLO LIFTS INTO THE SANDHILLS. STORM ACTIVITY IS EXPECTED TO BECOME LESS ORGANIZED FROM 06Z ONWARD AND BECOME SCATTERED OR ISOLATED BY 12Z WEDNESDAY. THE MODELS SHOW MVFR/IFR CIGS DEVELOPING FROM 04Z ONWARD ACROSS NRN NEBRASKA AND PERHAPS ACROSS THE SANDHILLS ALSO. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JACOBS SHORT TERM...CDC LONG TERM...TAYLOR AVIATION...CDC
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1155 AM CDT TUE AUG 5 2014 .UPDATE... ISSUED AT 1155 AM CDT TUE AUG 5 2014 MADE A FEW MINOR CHANGES TO AFTERNOON GRIDS AND PRODUCTS EARLIER. WILL TWEAK THINGS AGAIN BY AROUND 1 PM OR SO. RECENT HRRR MODEL RUNS DEPICT STORMS DEVELOP ACROSS PARTS OF NERN NE THIS AFTERNOON AND EVENING. BASED ON THE PATTERN...ALONG WITH THE EXPECTED AMOUNT OF 0-6 KM SHEAR AND DEGREE OF INSTABILITY...IT APPEARS A FEW STORMS MAY APPROACH SEVERE LIMITS. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 250 AM CDT TUE AUG 5 2014 TIMING AND EXTENT OF VARIOUS CONVECTIVE SYSTEMS REMAINS THE PRIMARY FORECAST CONCERN AND CHALLENGE. UPPER RIDGE AXIS WAS LOCATED OVER THE WESTERN HIGH PLAINS EARLY THIS MORNING WITH ONGOING CONVECTION ALONG THE NORTHERN NEBRASKA BORDER STRETCHING FROM SOUTH CENTRAL SOUTH DAKOTA INTO NORTHEAST NEBRASKA AND WEST CENTRAL IOWA. NEW DEVELOPMENT WAS OCCURRING OVER EAST CENTRAL NEBRASKA AROUND OMAHA SINCE 07Z. MODELS SUGGEST THE SHORT TERM WILL BE PUNCTUATED BY PERIODS OF THUNDERSTORMS WITH THE PRIMARY LOCATION CONFINED TO THE NORTH AND EAST OF THE FORECAST AREA INITIALLY TODAY THROUGH WEDNESDAY. MORE WIDESPREAD CONVECTION IS INDICATED ACROSS THE AREA WEDNESDAY NIGHT AND THURSDAY AS ADDITIONAL SHORT WAVES COME ACROSS THE TOP OF THE RIDGE PUSHING THE STRONGER FLOW A BIT FURTHER SOUTH AND ACROSS THE AREA. HARD TO CALL ON TIMING OF EVENTS SO A BROADBRUSH OF POPS COVER MUCH OF THE PERIOD. TEMPERATURES ALSO LIKELY TO BE IMPACTED BY EXTENT OF PRECIP AND CLOUD COVER SO A BLEND OF GUIDANCE USED. .LONG TERM...(THURSDAY NIGHT THROUGH MONDAY) ISSUED AT 250 AM CDT TUE AUG 5 2014 SAME GENERAL PATTERN REMAINS IN PLACE FOR MUCH OF THE EXTENDED PERIOD THROUGH THE WEEKEND BEFORE RIDGE REBUILDS OVER THE WESTERN CONUS AND TROUGH BEGINS TO DEVELOP OVER THE EAST. && .AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1155 AM CDT TUE AUG 5 2014 OUTSIDE OF TSRA ACTIVITY...GENERALLY EXPECT VFR CONDITIONS EXCEPT FOR SOME PATCHY FOG AROUND SUNRISE WEDNESDAY. BEST CHANCES FOR MVFR CEILINGS AND VSBYS WITH TSRA BEFORE 06Z WOULD BE AT KOFK... AND WILL WRITE TAFS THAT WAY. MAY LEAVE OUT MENTION OF TSRA AT KOMA AND KLNK FOR NOW...DUE TO UNCERTAINTY AND POTENTIAL BEING MOSTLY AFTER 06Z. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ UPDATE...MILLER SHORT TERM...FOBERT LONG TERM...FOBERT AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
255 PM MDT TUE AUG 5 2014 .SYNOPSIS... SHOWERS AND THUNDERSTORMS WILL FAVOR EASTERN NEW MEXICO THROUGH THE EVENING HOURS. A FEW STORMS MAY PRODUCE GUSTY WINDS AND HAIL. ON WEDNESDAY...STORM COVERAGE WILL DECREASE SIGNIFICANTLY AS DRY AIR CONTINUES TO MOVE INTO THE STATE. IF STORMS DEVELOP...THEY WILL FAVOR THE SOUTHWEST AND SOUTH CENTRAL MOUNTAINS. MEANWHILE... TEMPERATURES WILL CLIMB NEAR OR ABOVE SEASONAL NORMALS. MOISTURE WILL SLOWLY START TO MOVE FROM SOUTH TO NORTH...BACK INTO THE LAND OF ENCHANTMENT...THURSDAY THROUGH THE WEEKEND. STORM COVERAGE WILL SLOWLY START TO INCREASE...AND THE POTENTIAL FOR HEAVY RAIN WILL RETURN. HOWEVER...OVERALL COVERAGE IS EXPECTED TO BE LESS THAN RECENT WEEKS. && .DISCUSSION... MUCH DRIER MID AND UPPER LEVEL AIR MOVING INTO NM PER WV SATELLITE IMAGERY AND 12Z FGZ SOUNDING. AS SUCH...CONVECTION HAS REALLY STRUGGLED TO START...OR MAINTAIN ITSELF WEST OF THE CENTRAL MTN CHAIN. MID LEVEL MOISTURE GRADIENT LIKELY SETTING UP ALONG THE CENTRAL MT CHAIN...AND THIS COMBINED WITH OROGRAPHIC LIFT HAS PRODUCED A FEW SHOWERS AND TSTMS. WITH THE AID OF A WEAK 700 MB TROUGH ACROSS NORTHERN NM...AND DRY AIR PUNCHING INTO MID LEVELS...HAVE ALREADY SEEN ONE SEVERE STORM ACROSS THE NE...AND A FEW MORE STRONG OR SEVERE STORMS ARE NOT OUT OF THE QUESTION. QUARTER SIZE HAIL AND GUSTY WINDS WOULD BE THE MAIN THREATS. THE GOOD NEWS IS THAT WITH STORM MOTIONS AVERAGING 10 TO 20 MPH...THE THREAT FOR FLOODING HAS CONSIDERABLY DECREASED...THOUGH ALSO NOT OUT OF THE QUESTION. LATEST AVAILABLE HRRR SUGGESTS THAT MUCH OF THE CONVECTION TONIGHT WILL DIMINISH BY SUNSET. DRY AIR CONTINUING TO FILTER IN COMBINED WITH THE UPPER LEVEL HIGH BUILDING BACK TO THE NORTH WILL RESULT IN AN EVEN BIGGER DOWN TICK IN STORM COVERAGE ON WEDNESDAY. PWATS LOOK TO CRATER TO AROUND 0.50 INCHES...SIMILAR TO WHAT WAS OBSERVED ON THE FGZ SOUNDING THIS AM. TEMPERATURES WILL CLIMB SEVERAL DEGREES...WITH ALL AREAS SEEING NEAR TO ABOVE NORMAL TEMPS FOR THE FIRST TIME IN A WHILE. MODELS SUGGEST THE UPPER HIGH WILL INCH EASTWARD ON THURSDAY...AS SOME DISTURBANCE...LIKELY FROM THE PREVIOUS DAYS CONVECTION OVER MEXICO...WILL MOVE NORTHWARD INTO SOUTHERN NM. PWATS WILL CREEP UP ON THURSDAY...BUT WILL REMAIN BELOW NORMAL FOR THIS TIME OF YEAR. NONETHELESS... A FEW MORE STORMS WILL BE POSSIBLE AT LEAST ACROSS THE SOUTHERN TIER OF THE CWA ON THURSDAY. ADDITIONALLY...THE NAM IS SUGGESTING AREAS ALONG AND JUST EAST OF THE CENTRAL MT CHAIN WILL BE A FAVORED AREA FOR STORM DEVELOPMENT. CONTINUED TO CARRY HIGHER POPS HERE...BUT NOT OVERLY SOLD YET. NEAR AND BEHIND A BACK DOOR FRONT WITH AMPLE LOW LEVEL MOISTURE BEHIND IT ACROSS THE FAR NE MAY BE A BETTER BET FOR STORMS. LOOKING FOR A BIT MORE MOISTURE ON FRIDAY AS THE UPPER HIGH SHIFTS OVER OKLAHOMA...THOUGH MODELS ARE NOT VERY AMBITIOUS AT BRING THE MOISTURE NORTHWARD DESPITE THE FAVORABLE PATTERN. THIS MAY CHANGE IN THE COMING DAYS. THE WEEKEND DOES NOT LOOK TOO MUCH DIFFERENT FROM FRIDAY...OTHER THAN THERE MAY BE A BIT MORE MOISTURE AND STORMS AROUND. PWAT VALUES ARE PROGGED TO BE RIGHT AROUND NORMAL FOR AUGUST. LOOKS LIKE EARLY NEXT WEEK THE UPPER HIGH WILL SHIFT BACK OVER NM...DIVERTING THE MOISTURE PLUME WESTWARD OVER ARIZONA. 34 && .FIRE WEATHER... NO MAJOR CHANGES TO THE GRIDDED FORECAST. DID LOWER DEWPOINT VALUES THUS RH ACROSS MOST OF THE FORECAST AREA DURING THE NEXT FEW DAYS. DESPITE THE DYNAMIC DRY SLOT/MID LEVEL DRY INTRUSION PATTERN...VEGETATION WILL BE GOING OVERTIME IN TERMS OF TRANSPIRATION AT NIGHT SO RAISED OVERNIGHT DEWPOINT VALUES SOME ACROSS THE EAST. MOIST SOILS WILL ALSO KEEP DEWPOINT READINGS FROM FALLING TOO FAR BELOW MODEL GUIDANCE. WENT WITH MORE OF A MODEL BLEND. EITHER WAY...HUMIDITY VALUES FALL BELOW SEASONABLE LEVELS WED/THUR PRETTY MUCH AREAWIDE. THEN MORE SEASONABLE READINGS EXCEPT FOR THE FOUR CORNERS BY FRIDAY AND LASTING INTO THE WEEKEND. LOOKING AT SOME SINGLE DIGIT RH READINGS FOR THE FOUR CORNERS DURING THE UPCOMING FEW DAYS SO PAY MORE ATTENTION TO FIRE STARTS UP THAT BECAUSE OF THE DRIER CONDITIONS. AS FAR AS WETTING RAIN...OVERALL COVERAGE WILL DECREASE PRETTY SIGNIFICANTLY COMPARED TO THE PAST WEEK. A FEW WETTING STORMS FAVORING THE EASTERN THIRD TO HALF WILL OCCUR REST OF TODAY BUT PRETTY ISOLATED. THE DRIER AIR ALOFT WILL KEEP CELLS PRETTY LIMITED WEDNESDAY. A BAGGY TROUGH OR WEAKNESS TO THE WEST OF THE STATE WILL EVENTUALLY DRAW SOME MOISTURE NORTHWARD FROM MEXICO AS THE WEEK PROGRESSES. THIS LOOKS TO BE A SLOW TRANSITION IN TERMS OF WETTING RAIN COVERAGE BUT THE TRANSITION WILL OCCUR BASED ON MODEL COMPARISONS THE PAST DAY OR SO AND TAKING INTO ACCOUNT THE TIME OF YEAR. THE UPPER RIDGE TODAY WILL HAVE SAGGED SOUTHWARD OVER NORTHERN MEXICO BUT AS THE WEEK PROGRESSES LOOK FOR IT TO TRY TO STRENGTHEN NORTHWARD AND EVENTUALLY GET SHUNTED EASTWARD DUE TO THE WESTERN TROUGH. THE NECESSARY DRIVERS OR INGREDIENTS WOULD BE IN PLACE TO DRAW MONSOONAL MOISTURE NORTHWARD FROM MEXICO. THE MAIN QUESTION IS HOW QUICKLY. TEMPERATURES DURING THIS PERIOD WOULD EVENTUALLY WARM SOME BUT HIGHS WOULD GENERALLY BE NEAR TO SLIGHTLY BELOW NORMAL WEST AND NEAR TO SLIGHTLY ABOVE NORMAL EAST. OVERALL WIND SPEEDS LOOK TO BE ON THE LIGHTER SIDE DUE TO THE LACK OF ANY SURFACE OR UPPER LEVEL DRIVERS. THE STRONGEST WIND FOR THE FORECAST AREA LOOKS TO BE TODAY AND FAVOR THE EAST. ANY THUNDER CELLS THAT DO DEVELOP COULD CONTAIN STRONG OUTFLOW WINDS DUE TO THE MID LEVEL/SFC DRYING. LOOKING AT A RETURN TO SOME HAINES 5/6 VALUES DURING THE NEXT FEW DAYS. HAINES 6 MOST LIKELY ACROSS THE FOUR CORNERS THURSDAY. VENTILATION LOOKS TO BE PRETTY DECENT MOST AREAS THROUGH THE END OF THE WEEK BUT LOWER SOME DURING THE WEEKEND. GFS/ECMWF SHOWS SOME CONTINUED ATMOSPHERIC MOISTENING DURING THE WEEKEND INTO EARLY NEXT WEEK AS THE MEAN HIGH PRESSURE CELL PLACEMENT WOULD BE TO THE EAST OF THE STATE. STILL LOOKING AT A BAGGY TROUGH TO THE WEST. THUS...THE MONSOONAL MOISTURE PLUME SHOULD EVENTUALLY CONCENTRATE ITSELF OVER PORTIONS OF AZ/NM. HOW MUCH AND EXACT PLACEMENT IS STILL A LITTLE TRICKY. ANOTHER FLY IN THE OINTMENT WOULD BE AN EASTERLY WAVE COMING OFF THE GULF OF MEXICO. IT IS MOST PROBABLE THAT THIS EASTERLY WAVE WOULD DRAG DRIER MID LEVEL AIR OVER PORTIONS OF THE FORECAST AREA VERSUS PROVIDING A MOISTENING TREND BUT HAVE TO WAIT AND SEE. A PRETTY TYPICAL PERIOD FOR THE WET PHASE OF THE MONSOON SUMMER PERIOD SO NOTHING REAL UNUSUAL UPCOMING. 50 && .AVIATION... 18Z TAF CYCLE MUCH DRIER AIR HAS MOVED OVER THE FORECAST AREA THIS MORNING. THIS WILL LIMIT SH/TS DEVELOPMENT AS WELL AS IMPACTS TO AIRPORTS. USING VCSH OR TEMPO SH FOR SOME OF THE LOCATIONS THAT ARE MORE LIKELY TO BE IMPACTED. FAIRLY DYNAMIC DAY SO LOOK FOR SOME UPDATES ACCORDINGLY. OUTFLOW WIND WOULD PROBABLY BE THE MAIN IMPACT SO USING GUSTS TO 30-35 KT BUT CANT RULE OUT STRONGER. SOME OF THE WETTER STORMS WITH LOWER CIGS/VIS FOR A BRIEF PERIOD EAST OF THE CNTRL MTNS. ACTIVITY SHOULD DWINDLE SOON AFTER SUNSET. 50 && .PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 59 90 56 92 / 5 5 5 0 DULCE........................... 53 86 45 85 / 10 5 5 10 CUBA............................ 53 85 51 84 / 5 5 5 10 GALLUP.......................... 49 86 46 86 / 5 5 5 5 EL MORRO........................ 48 83 44 80 / 5 10 5 10 GRANTS.......................... 52 86 48 84 / 5 5 5 10 QUEMADO......................... 50 83 50 80 / 10 10 10 10 GLENWOOD........................ 53 89 58 88 / 10 10 10 10 CHAMA........................... 44 79 43 80 / 20 5 5 20 LOS ALAMOS...................... 54 85 54 82 / 20 5 5 20 PECOS........................... 52 84 54 80 / 10 5 5 30 CERRO/QUESTA.................... 50 81 48 80 / 20 5 5 20 RED RIVER....................... 43 74 44 73 / 20 10 10 30 ANGEL FIRE...................... 42 78 42 78 / 20 5 5 30 TAOS............................ 50 84 48 85 / 20 5 5 10 MORA............................ 52 84 52 81 / 20 5 5 30 ESPANOLA........................ 58 89 58 87 / 10 0 5 10 SANTA FE........................ 54 84 57 84 / 10 5 5 20 SANTA FE AIRPORT................ 55 88 57 88 / 5 5 5 20 ALBUQUERQUE FOOTHILLS........... 60 89 62 88 / 5 5 5 10 ALBUQUERQUE HEIGHTS............. 63 91 64 90 / 5 5 5 10 ALBUQUERQUE VALLEY.............. 60 92 61 92 / 5 0 5 10 ALBUQUERQUE WEST MESA........... 62 91 62 91 / 5 0 5 10 LOS LUNAS....................... 60 92 62 91 / 5 5 5 10 RIO RANCHO...................... 61 93 62 92 / 5 0 5 10 SOCORRO......................... 64 94 65 94 / 10 5 10 10 SANDIA PARK/CEDAR CREST......... 56 87 59 85 / 10 5 5 20 TIJERAS......................... 57 88 59 87 / 10 5 5 20 MORIARTY/ESTANCIA............... 54 86 54 83 / 10 5 10 30 CLINES CORNERS.................. 56 85 57 86 / 10 5 5 30 GRAN QUIVIRA.................... 58 86 59 84 / 20 10 10 30 CARRIZOZO....................... 61 88 63 86 / 10 5 10 20 RUIDOSO......................... 56 82 58 81 / 20 20 20 40 CAPULIN......................... 54 86 56 83 / 40 10 5 30 RATON........................... 55 89 54 88 / 20 5 5 30 SPRINGER........................ 56 90 53 88 / 20 5 5 30 LAS VEGAS....................... 55 86 54 85 / 20 5 5 30 CLAYTON......................... 62 94 63 94 / 30 5 5 20 ROY............................. 61 90 57 88 / 20 5 5 20 CONCHAS......................... 67 97 64 96 / 20 0 0 10 SANTA ROSA...................... 64 94 62 92 / 20 5 5 20 TUCUMCARI....................... 65 99 65 99 / 20 0 0 10 CLOVIS.......................... 63 95 65 94 / 10 0 5 10 PORTALES........................ 63 96 65 95 / 10 0 5 10 FORT SUMNER..................... 66 96 66 94 / 20 0 5 10 ROSWELL......................... 67 98 67 97 / 10 0 5 10 PICACHO......................... 61 90 63 90 / 20 5 10 30 ELK............................. 58 83 63 82 / 20 10 10 40 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 34
AREA FORECAST DISCUSSION
NWS BUFFALO NY
532 PM EDT TUE AUG 5 2014 .SYNOPSIS... A COLD FRONT WILL CROSS THE REGION TONIGHT...BRINGING SCATTERED SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WITH SLIGHTLY COOLER AIR WILL MOVE ACROSS THE REGION BEHIND THE FRONT. A FEW SHOWERS MAY STILL LINGER ON WEDNESDAY BEFORE DRY WEATHER RETURNS BY THE END OF THE WEEK. && .NEAR TERM /THROUGH WEDNESDAY/... A MODEST SHORTWAVE WILL DIG INTO THE BASE OF A MEAN UPPER LEVEL TROUGH OVER EASTERN CANADA/NEW ENGLAND TONIGHT. RADAR SHOWS A SLUG OF SHOWERS AND THUNDERSTORMS ACROSS CENTRAL NEW YORK BRINGING LOCALLY HEAVY RAINFALL. THE HRRR HAS THIS AREA WELL HANDLED...AND IS SUPPORTED BY SATELLITE TRENDS IN MOVING THIS AREA EAST OF OUR CWA JUST BEFORE SUNSET. THERE MAY BE A FEW SHOWERS AND THUNDERSTORMS THAT DEVELOP ACROSS THE ST LAWRENCE...BUT OTHER THAN THIS IT APPEARS ANY OTHER SHOWERS BEHIND THIS SHOULD BE FAIRLY SPARSE. EXPECT CLOUDS TO LINGER IN MOST AREAS...BUT THERE MAY BE SOME CLEARING IN WESTERN PORTIONS WHICH COULD RESULT IN PATCHY FOG. HIGH PRESSURE BUILDS DOWN BEHIND THE FRONT LATER TONIGHT AND A NOTABLE AREA OF SUBSIDENCE DEVELOPS ACROSS THE AREA IN ITS WAKE. CLOUDS WILL GRADUALLY DECREASE ON WEDNESDAY...HOWEVER SCATTERED CONVECTION POSSIBLE SOUTHERN TIER LATE WEDNESDAY MORNING INTO THE AFTERNOON IN CLOSER PROXIMITY TO COLD FRONT. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/... BETWEEN WEDNESDAY NIGHT AND THURSDAY...THE PERSISTENT UPPER LEVEL TROUGHING THAT HAS PLAGUED OUR REGION FOR MUCH OF THE PAST WEEK AND A HALF WILL FINALLY BEGIN TO SLIDE EAST INTO NEW ENGLAND...WHILE SURFACE HIGH PRESSURE AND DRIER AIR SLOWLY BUILDS EASTWARD FROM THE CENTRAL GREAT LAKES. WHILE THIS SHOULD RESULT IN DRY WEATHER FOR THE MAJORITY OF OUR AREA...THE EASTERN FINGER LAKES AND NORTH COUNTRY WILL BE SUBJECT TO ONE MORE ROUND OF SCATTERED SHOWERS/THUNDERSTORMS AS ONE FINAL SHORTWAVE IMPULSE DROPS THROUGH THE BACKSIDE OF THE DEPARTING TROUGH...WITH THE BULK OF THESE LIKELY COMING BETWEEN LATER WEDNESDAY NIGHT AND EARLY THURSDAY AFTERNOON. AFTER THAT...THE REMAINDER OF THE PERIOD SHOULD FEATURE DRY AND QUIET WEATHER AS THE UPPER TROUGH FINALLY SLIDES EAST INTO NEW ENGLAND AND THE CANADIAN MARITIMES...AND THE AFOREMENTIONED SURFACE RIDGE SETTLES DIRECTLY ACROSS THE LOWER GREAT LAKES. WITH RESPECT TO TEMPERATURES...READINGS WILL CONTINUE TO AVERAGE A LITTLE BELOW NORMAL THROUGH THE END OF THE WORK WEEK...WITH DAYTIME HIGHS LARGELY IN THE MID 70S AND NIGHTTIME LOWS RANGING THROUGH THE 50S...THOUGH SOME INTERIOR PORTIONS OF THE SOUTHERN TIER COULD SEE LOWS IN THE UPPER 40S THURSDAY NIGHT. && .LONG TERM /SATURDAY THROUGH TUESDAY/... THE FIRST THREE DAYS OF THE LONG TERM PERIOD STILL LOOKS TO FEATURE A WELCOME PERIOD OF UNEVENTFUL WEATHER AS UPPER LEVEL RIDGING BUILDS EASTWARD ACROSS THE LOWER GREAT LAKES AND INTO NEW YORK STATE AND NEW ENGLAND...WHILE THE AXIS OF ITS ATTENDANT SURFACE RIDGE SLOWLY DRIFTS EAST TO A POSITION JUST OFF THE ATLANTIC COASTLINE. WHILE A STRAY SHOWER OR STORM CANNOT BE TOTALLY RULED OUT ACROSS THE SOUTHERN TIER SUNDAY/MONDAY AFTERNOONS AS DAYTIME HEATING INTERACTS WITH SLOWLY INCREASING MOISTURE RETURNING AROUND THE BACKSIDE OF THE DEPARTING SURFACE RIDGE...THIS PORTION OF THE PERIOD SHOULD LARGELY FEATURE DRY AND FAIR WEATHER. WITH A GRADUAL WARMING OF OUR AIRMASS TAKING PLACE...TEMPS SHOULD ALSO RECOVER BACK TO NORMAL LEVELS WITH DAYTIME HIGHS REACHING INTO THE UPPER 70S/LOWER 80S EACH DAY...AND NIGHTTIME LOWS LARGELY RANGING IN THE MID 50S TO LOWER 60S. LATE IN THE PERIOD...THE NEXT NOTEWORTHY MID-LEVEL IMPULSE WILL WORK INTO THE LOWER GREAT LAKES. WHILE THE GFS/ECMWF DIFFER NOTICEABLY ON THE SPEED AND STRENGTH OF THIS FEATURE...BOTH SUGGEST GENERAL CHANCES OF SHOWERS AND THUNDERSTORMS RETURNING TO THE AREA BY NEXT TUESDAY. WITH THIS IN MIND...HAVE INTRODUCED SOME LOW CHANCE POPS FOR THE NEW DAY 7...WITH TEMPERATURES OTHERWISE REMAINING NEAR NORMAL LEVELS TO CLOSE OUT THE EXTENDED PORTION OF THE FORECAST. && .AVIATION /22Z TUESDAY THROUGH SUNDAY/... SLUG OF SHOWERS AND THUNDERSTORMS WILL CONTINUE TO MOVE EAST AND AWAY FROM OUR TAF SITES. SCATTERED TSTMS MAY CLIP ART...OTHERWISE EXPECT TAF SITES TO STAY DRY OVERNIGHT. BEHIND THIS...THE MAIN CONCERN WILL BE FOG DEVELOPMENT. FOR THE MOST PART...EXPECT LINGERING MOISTURE TO RESULT IN VFR-MVFR CIGS OVERNIGHT...HOWEVER IF THERE IS ANY CLEARING IT WILL NOT TAKE LONG FOR FOG TO DEVELOP GIVEN TIGHT TEMP-DEW POINT SPREADS. LEFTOVER CLOUDS WILL REMAIN OVERNIGHT INTO EARLY WEDNESDAY WITH ISOLATED -SHRA ESPECIALLY ACROSS THE SOUTHERN TIER. DRIER AIR ADVECTS SOUTHWARD ON WEDNESDAY WITH CLOUDS GRADUALLY DECREASING. SCATTERED CONVECTION POSSIBLE SOUTHERN TIER 14-20Z WEDNESDAY IN CLOSER PROXIMITY TO COLD FRONT. OUTLOOK... WEDNESDAY NIGHT THROUGH SUNDAY...OTHER THAN VALLEY FOG...NO SIGNIFICANT WEATHER EXPECTED. && .MARINE... A COLD FRONT WILL CROSS THE LOWER GREAT LAKES TONIGHT BRINGING SCATTERED SHOWERS AND THUNDERSTORMS. OTHERWISE...FEW CONCERNS FOR MARINE PURPOSES...AS LIGHT WINDS AND LOW SIGNIFICANT WAVE HEIGHTS ARE EXPECTED THROUGH THE THE END OF THE WEEK. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...NONE. && $$ SYNOPSIS...FRANKLIN NEAR TERM...APFFEL/FRANKLIN SHORT TERM...JJR LONG TERM...JJR AVIATION...APFFEL/FRANKLIN MARINE...FRANKLIN
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
129 PM EDT TUE AUG 5 2014 .SYNOPSIS... A COLD FRONT SHIFTING SOUTHEASTWARD FROM ONTARIO AND QUEBEC WILL BRING WIDELY SCATTERED SHOWERS AND THUNDERSTORMS TO THE NORTH COUNTRY THIS AFTERNOON. A FEW STRONGER STORMS ARE POSSIBLE...WITH BRIEF HEAVY DOWNPOURS AND SMALL HAIL. THE FRONT CLEARS THE AREA TO THE SOUTH SETTING UP A PLEASANT DAY ON WEDNESDAY WITH LOWER HUMIDITY LEVELS AND HIGH TEMPERATURES MAINLY IN THE MID TO UPPER 70S. AN UPPER-LEVEL DISTURBANCE WILL BRING ADDITIONAL SHOWERS AND ISOLATED THUNDERSTORMS TO THE REGION FOR THURSDAY AFTERNOON. ACTIVITY WILL BE MOST WIDESPREAD ACROSS VERMONT. GENERALLY FAIR CONDITIONS ARE EXPECTED WITH HIGH PRESSURE ON FRIDAY AND THROUGH THE WEEKEND...WITH AFTERNOON TEMPERATURES CLIMBING BACK INTO THE LOWER 80S. && .NEAR TERM /UNTIL 7 PM THIS EVENING/... AS OF 1253 PM EDT TUESDAY...CONVECTION IS QUICKLY DEVELOPING OVER THE PAST HOUR. AND JUST A FEW MINUTES AGO WE HAD THE FIRST LIGHTNING STROKE IN THE CELL NORTH OF PLATTSBURGH (WHICH BY THE WAY HAS A LITTLE BIT OF HAIL WELL ALOFT IN IT). LATEST LAPS MESOANALYSIS SHOWS 1500-2500 J/KG CAPE FOR MOST OF VERMONT, THANKS IN LARGE PART TO TEMPERATURES IN THE UPPER 70S TO LOWER 80S AND DEWPOINTS IN THE LOW/MID 60S. CAPE VALUES ARE LOWER ACROSS NORTHERN NEW YORK DUE TO THE EARLIER CLOUDINESS WHICH HAVE HELD BACK TEMPERATURES A LITTLE BIT. AS TYPICAL, THE FIRST CONVECTION HAS BEEN ALONG THE EASTERN SLOPES OF THE `DACKS. MOST OF THE 12Z/15Z RUNS OF MESO-SCALE MODELS SHOW THIS TO ONE EXTENT OR ANOTHER. THESE CELLS THEN DEVELOP AND PUSH EAST AS ADDITIONAL CONVECTION SHOULD FORM ALONG THE CENTRAL GREEN MOUNTAINS ABOUT 18Z. WESTERLY STEERING FLOW ALOFT SHOULD THEN MEAN THE BULK OF THE SHOWERS/STORMS ARE INTO EASTERN VERMONT AFTER 4-5PM. SURFACE FRONT STILL NOT QUITE TO THE ST LAWRENCE VALLEY, BUT IT WILL SLOWLY BE WORKING ITS WAY ACROSS NORTHERN NEW YORK DURING THE AFTERNOON. COULD SEE A FEW ADDITIONAL SCATTERED SHOWERS/ISOLATED T-STORMS FIRE AHEAD OF THAT. MESO-MODELS ALSO INDICATE THIS POSSIBILITY. SMALL HAIL STILL LOOKING LIKE THE MAIN ISSUE WITH ANY STRONGER T-STORMS THAT COULD DEVELOP. SO THE FORECAST UPDATE HAS BEEN PRIMARILY TO TRY TO BETTER TIME/LOCATE THE HIGHER LEVEL OF CONVECTIVE COVERAGE. RELIED ON A MIX OF BTV4, BTV6 AND HRRR MODELS. BASICALLY MAKES THE NORTHERN HALF OF VERMONT AS THE FOCUS OF CONVECTION. TWEAKED TEMPERATURES A BIT UP AS WELL, ESPECIALLY FOR VERMONT. BTV ALREADY REACHED 81F, SO PRIOR TO THE SHOWERS COMING INTO THE AREA, WE COULD RISE ANOTHER DEGREE OR TWO. OTHERWISE, WE`LL SEE HOW THIS AFTERNOON EVOLVES. NOT EVERYONE WILL SEE ANY SHOWERS/STORMS, BUT ENOUGH ON THE RADAR SCOPE TO KEEP IT INTERESTING. && .SHORT TERM /7 PM THIS EVENING THROUGH THURSDAY/... AS OF 314 AM EDT TUESDAY...THE WEAK COLD FRONTAL BOUNDARY SLIDES FAR ENOUGH SEWD INTO SOUTHERN NEW ENGLAND THAT OUR WEATHER SHOULD BE PRECIPITATION FREE ON WEDNESDAY. KEPT JUST A SLIGHT CHANCE OF A SHOWER (20 POP) ACROSS PORTIONS OF RUTLAND/WINDSOR COUNTIES...AND DRY ELSEWHERE. ALSO LOOKING AT SOME LOWER HUMIDITY BEING USHERED IN BEHIND THE FRONT...WITH SFC DEWPOINTS DROPPING INTO THE LOWER 50S. 850MB TEMPS OF +10C TO +11C SUPPORT AFTERNOON HIGHS IN THE MID-UPR 70S FOR MOST LOCATIONS. MOSTLY SUNNY SKIES AND LIGHT NW WINDS WILL MAKE FOR A PLEASANT DAY. GENERALLY TRANQUIL WEDNESDAY NIGHT...THOUGH WE/LL NEED TO WATCH A SHORTWAVE TROUGH MOVING SEWD FROM ONTARIO/SWRN QUEBEC THROUGH THE PARENT LONGWAVE TROUGH. THIS EMBEDDED FEATURE MAY REACH THE ST. LAWRENCE VALLEY DURING THE PRE-DAWN HOURS. SOME INDICATIONS IN 00Z GFS/NAM/BTV-4KM WRF THAT THIS SHORTWAVE TROUGH WILL BE ASSOCIATED WITH RAIN SHOWER ACTIVITY MOVING INTO THE ST. LAWRENCE VALLEY BETWEEN 09-12Z. OTHERWISE...LOOKING AT DRY AND MOSTLY CLEAR CONDITIONS ELSEWHERE. SHOULD SET UP A FAVORABLE CONDITIONS FOR RADIATIONAL FOG IN THE VALLEYS OF CENTRAL/ERN VT. LOWS WEDNESDAY NIGHT EXPECTED IN THE LOW-MID 50S...EXCEPT MID-UPR 40S IN THE ADIRONDACKS AND VERMONT`S NORTHEAST KINGDOM. PREVAILING CYCLONIC MID-TROPOSPHERIC FLOW AND PASSAGE OF EMBEDDED SHORTWAVE TROUGH AND THERMAL TROUGH DURING DAYTIME HEATING WILL RESULT IN DEVELOPMENT OF SCATTERED SHOWERS AND PERHAPS ISOLD TSTM ACTIVITY FOR THURSDAY AFTERNOON. WITH SFC DEWPOINTS ONLY IN THE 50S...CAPE VALUES WILL BE RATHER MODEST (AROUND 500-1000 J/KG AT BEST)...AND WITH ONLY 15-20 KTS OF NWLY DEEP-LAYER FLOW...NOT ANTICIPATING ANY SEVERE THREAT. IT APPEARS BASED ON PROJECTED TIMING THAT THE BEST FORCING WILL BE ACROSS VERMONT COINCIDENT WITH DAYTIME HEATING. THUS...HAVE PLACED THE HIGHEST POPS ACROSS VT AND THAT IS ALSO WHERE THE BEST POTENTIAL EXISTS FOR SURFACE- BASED THUNDERSTORM ACTIVITY. HIGHS GENERALLY IN THE LOW-MID 70S WITH INTERVALS OF PARTLY SUNNY CONDITIONS AWAY FROM SHOWERS AND TSTMS. NOT ANTICIPATING A WASHOUT...BUT THOSE WITH OUTDOOR PLANS SHOULD ANTICIPATE SOME SHOWER/THUNDERSTORM ACTIVITY AROUND WITH PERHAPS A BRIEF DOWNPOUR...ESPECIALLY FOR THE AFTERNOON HOURS. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... AS OF 333 AM EDT TUESDAY...THURSDAY NIGHT WILL SEE DECREASING SHOWERS AND STORMS AS THE COLD FRONT MOVES THROUGH THE REGION FROM WEST TO EAST. AN UPPER LEVEL WAVE EMBEDDED IN FLOW AROUND TROUGH WILL KEEP LINGERING SHOWERS ACROSS PORTIONS OF THE NORTHEAST KINGDOM ON FRIDAY. COVERAGE OF SHOWERS WILL BE LIMITED DUE TO DRYING NW FLOW DEVELOPING AS SFC HIGH PRESSURE BUILDS IN OVER SERN CANADA. 500 MB HT LEVEL INCREASES NOTICEABLY OVER THE WEEKEND...RESULTING IN DRY FORECAST. AS THE RIDGE CRESTS OVER THE REGION SATURDAY...S/SW FLOW WILL RETURN...FILTERING WARMER AIR. THIS WILL RESULT IN WARMING TREND...WITH MAX TEMPS FRIDAY AND SATURDAY RANGING FROM L60S TO L80S. TEMPERATURES INCREASE DURING THE WEEK WITH MAXES REACHING THE L80S IN THE VALLEYS. MIN TEMPERATURES WILL BE IN THE M50S IN THE MTNS AND U50S TO L60S IN THE VALLEYS. MONDAY MAY BE THE LAST COMPLETELY DRY DAY AS UPPER TROUGH APPROACHES FROM THE WEST. && .AVIATION /17Z TUESDAY THROUGH SUNDAY/... THROUGH 18Z WEDNESDAY...THOUGH PRIMARILY VFR...A MIX OF FLIGHT CATEGORIES ANTICIPATED THIS AFTN/EVENING WITH BRIEF MVFR TO IFR VISIBILITY IN SHOWERS/THUNDERSTORMS...MVFR CEILINGS AND POSSIBLE MIST DEVELOPMENT AT MSS AND SLK. REGIONAL RADAR SHOWS SCT SHOWERS/THUNDERSTORMS DEVELOPING AHEAD OF A COLD FRONT. INITIAL DEVELOPMENT IN THE CHAMPLAIN VALLEY AND EASTERN ADIRONDACKS...AND EXPECT AREAL COVERAGE TO INCREASE INTO THE AFTN/EVENING HRS. PRIMARY THREAT AREA FOR THUNDER AT PBG AND THE VT TAFS WITH ANY THUNDERSTORM CAPABLE OF DOWNPOURS...LOCAL TURBULENCE AND PERHAPS SOME SMALL HAIL. HAVE INDICATED VCTS FOR THESE TAFS UNDER THOSE EXPECTATIONS...WITH VCSH INDICATED AT SLK AND MSS WHERE AIRMASS IS A LITTLE MORE STABLE UNDER OVERCAST. WILL AMEND FOR LOWER VISIBILITY. COLD FRONT PUSHES SLOWLY SOUTH INTO THE OVERNIGHT...THOUGH BASED ON UPSTREAM OBS SKIES ARE NOT LIKELY TO FULLY CLEAR OUT EXCEPT AT SLK AND MSS THROUGH THE PRE-DAWN HOURS. FOR THAT REASON HAVE OPTED TO INTRODUCE SCT-BKN VFR/MVFR CEILINGS AND SHOW MIST AT MSS AND SLK. MORE SIGNIFICANT LIFTING OF CEILINGS AFTER 12Z. SOUTH WINDS AHEAD OF THE FRONT TO BECOME MORE VARIABLE AS FRONT APPROACHES...THEN TURNING NORTHERLY 4-6 KTS INTO WEDNESDAY. OUTLOOK 18Z WEDNESDAY THROUGH SATURDAY... 18Z WEDNESDAY THROUGH 12Z FRIDAY...PREDOMINANTLY VFR ALTHOUGH A CHANCE OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS EACH AFTERNOON AND EVENING...ALONG WITH THE POTENTIAL FOR IFR/LIFR FOG/BR DEVELOPMENT EACH NIGHT...MAINLY MPV/SLK. 12Z FRIDAY ONWARD...VFR UNDER BUILDING HIGH PRESSURE...HOWEVER PERIODS OF IFR IN FOG/BR POSSIBLE AT NIGHT...AGAIN MAINLY MPV/SLK. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...BANACOS NEAR TERM...NASH SHORT TERM...BANACOS LONG TERM...KGM AVIATION...LOCONTO
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
103 PM EDT TUE AUG 5 2014 .SYNOPSIS... A COLD FRONT SHIFTING SOUTHEASTWARD FROM ONTARIO AND QUEBEC WILL BRING WIDELY SCATTERED SHOWERS AND THUNDERSTORMS TO THE NORTH COUNTRY THIS AFTERNOON. A FEW STRONGER STORMS ARE POSSIBLE...WITH BRIEF HEAVY DOWNPOURS AND SMALL HAIL. THE FRONT CLEARS THE AREA TO THE SOUTH SETTING UP A PLEASANT DAY ON WEDNESDAY WITH LOWER HUMIDITY LEVELS AND HIGH TEMPERATURES MAINLY IN THE MID TO UPPER 70S. AN UPPER-LEVEL DISTURBANCE WILL BRING ADDITIONAL SHOWERS AND ISOLATED THUNDERSTORMS TO THE REGION FOR THURSDAY AFTERNOON. ACTIVITY WILL BE MOST WIDESPREAD ACROSS VERMONT. GENERALLY FAIR CONDITIONS ARE EXPECTED WITH HIGH PRESSURE ON FRIDAY AND THROUGH THE WEEKEND...WITH AFTERNOON TEMPERATURES CLIMBING BACK INTO THE LOWER 80S. && .NEAR TERM /UNTIL 7 PM THIS EVENING/... AS OF 1253 PM EDT TUESDAY...CONVECTION IS QUICKLY DEVELOPING OVER THE PAST HOUR. AND JUST A FEW MINUTES AGO WE HAD THE FIRST LIGHTNING STROKE IN THE CELL NORTH OF PLATTSBURGH (WHICH BY THE WAY HAS A LITTLE BIT OF HAIL WELL ALOFT IN IT). LATEST LAPS MESOANALYSIS SHOWS 1500-2500 J/KG CAPE FOR MOST OF VERMONT, THANKS IN LARGE PART TO TEMPERATURES IN THE UPPER 70S TO LOWER 80S AND DEWPOINTS IN THE LOW/MID 60S. CAPE VALUES ARE LOWER ACROSS NORTHERN NEW YORK DUE TO THE EARLIER CLOUDINESS WHICH HAVE HELD BACK TEMPERATURES A LITTLE BIT. AS TYPICAL, THE FIRST CONVECTION HAS BEEN ALONG THE EASTERN SLOPES OF THE `DACKS. MOST OF THE 12Z/15Z RUNS OF MESO-SCALE MODELS SHOW THIS TO ONE EXTENT OR ANOTHER. THESE CELLS THEN DEVELOP AND PUSH EAST AS ADDITIONAL CONVECTION SHOULD FORM ALONG THE CENTRAL GREEN MOUNTAINS ABOUT 18Z. WESTERLY STEERING FLOW ALOFT SHOULD THEN MEAN THE BULK OF THE SHOWERS/STORMS ARE INTO EASTERN VERMONT AFTER 4-5PM. SURFACE FRONT STILL NOT QUITE TO THE ST LAWRENCE VALLEY, BUT IT WILL SLOWLY BE WORKING ITS WAY ACROSS NORTHERN NEW YORK DURING THE AFTERNOON. COULD SEE A FEW ADDITIONAL SCATTERED SHOWERS/ISOLATED T-STORMS FIRE AHEAD OF THAT. MESO-MODELS ALSO INDICATE THIS POSSIBILITY. SMALL HAIL STILL LOOKING LIKE THE MAIN ISSUE WITH ANY STRONGER T-STORMS THAT COULD DEVELOP. SO THE FORECAST UPDATE HAS BEEN PRIMARILY TO TRY TO BETTER TIME/LOCATE THE HIGHER LEVEL OF CONVECTIVE COVERAGE. RELIED ON A MIX OF BTV4, BTV6 AND HRRR MODELS. BASICALLY MAKES THE NORTHERN HALF OF VERMONT AS THE FOCUS OF CONVECTION. TWEAKED TEMPERATURES A BIT UP AS WELL, ESPECIALLY FOR VERMONT. BTV ALREADY REACHED 81F, SO PRIOR TO THE SHOWERS COMING INTO THE AREA, WE COULD RISE ANOTHER DEGREE OR TWO. OTHERWISE, WE`LL SEE HOW THIS AFTERNOON EVOLVES. NOT EVERYONE WILL SEE ANY SHOWERS/STORMS, BUT ENOUGH ON THE RADAR SCOPE TO KEEP IT INTERESTING. && .SHORT TERM /7 PM THIS EVENING THROUGH THURSDAY/... AS OF 314 AM EDT TUESDAY...THE WEAK COLD FRONTAL BOUNDARY SLIDES FAR ENOUGH SEWD INTO SOUTHERN NEW ENGLAND THAT OUR WEATHER SHOULD BE PRECIPITATION FREE ON WEDNESDAY. KEPT JUST A SLIGHT CHANCE OF A SHOWER (20 POP) ACROSS PORTIONS OF RUTLAND/WINDSOR COUNTIES...AND DRY ELSEWHERE. ALSO LOOKING AT SOME LOWER HUMIDITY BEING USHERED IN BEHIND THE FRONT...WITH SFC DEWPOINTS DROPPING INTO THE LOWER 50S. 850MB TEMPS OF +10C TO +11C SUPPORT AFTERNOON HIGHS IN THE MID-UPR 70S FOR MOST LOCATIONS. MOSTLY SUNNY SKIES AND LIGHT NW WINDS WILL MAKE FOR A PLEASANT DAY. GENERALLY TRANQUIL WEDNESDAY NIGHT...THOUGH WE/LL NEED TO WATCH A SHORTWAVE TROUGH MOVING SEWD FROM ONTARIO/SWRN QUEBEC THROUGH THE PARENT LONGWAVE TROUGH. THIS EMBEDDED FEATURE MAY REACH THE ST. LAWRENCE VALLEY DURING THE PRE-DAWN HOURS. SOME INDICATIONS IN 00Z GFS/NAM/BTV-4KM WRF THAT THIS SHORTWAVE TROUGH WILL BE ASSOCIATED WITH RAIN SHOWER ACTIVITY MOVING INTO THE ST. LAWRENCE VALLEY BETWEEN 09-12Z. OTHERWISE...LOOKING AT DRY AND MOSTLY CLEAR CONDITIONS ELSEWHERE. SHOULD SET UP A FAVORABLE CONDITIONS FOR RADIATIONAL FOG IN THE VALLEYS OF CENTRAL/ERN VT. LOWS WEDNESDAY NIGHT EXPECTED IN THE LOW-MID 50S...EXCEPT MID-UPR 40S IN THE ADIRONDACKS AND VERMONT`S NORTHEAST KINGDOM. PREVAILING CYCLONIC MID-TROPOSPHERIC FLOW AND PASSAGE OF EMBEDDED SHORTWAVE TROUGH AND THERMAL TROUGH DURING DAYTIME HEATING WILL RESULT IN DEVELOPMENT OF SCATTERED SHOWERS AND PERHAPS ISOLD TSTM ACTIVITY FOR THURSDAY AFTERNOON. WITH SFC DEWPOINTS ONLY IN THE 50S...CAPE VALUES WILL BE RATHER MODEST (AROUND 500-1000 J/KG AT BEST)...AND WITH ONLY 15-20 KTS OF NWLY DEEP-LAYER FLOW...NOT ANTICIPATING ANY SEVERE THREAT. IT APPEARS BASED ON PROJECTED TIMING THAT THE BEST FORCING WILL BE ACROSS VERMONT COINCIDENT WITH DAYTIME HEATING. THUS...HAVE PLACED THE HIGHEST POPS ACROSS VT AND THAT IS ALSO WHERE THE BEST POTENTIAL EXISTS FOR SURFACE- BASED THUNDERSTORM ACTIVITY. HIGHS GENERALLY IN THE LOW-MID 70S WITH INTERVALS OF PARTLY SUNNY CONDITIONS AWAY FROM SHOWERS AND TSTMS. NOT ANTICIPATING A WASHOUT...BUT THOSE WITH OUTDOOR PLANS SHOULD ANTICIPATE SOME SHOWER/THUNDERSTORM ACTIVITY AROUND WITH PERHAPS A BRIEF DOWNPOUR...ESPECIALLY FOR THE AFTERNOON HOURS. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... AS OF 333 AM EDT TUESDAY...THURSDAY NIGHT WILL SEE DECREASING SHOWERS AND STORMS AS THE COLD FRONT MOVES THROUGH THE REGION FROM WEST TO EAST. AN UPPER LEVEL WAVE EMBEDDED IN FLOW AROUND TROUGH WILL KEEP LINGERING SHOWERS ACROSS PORTIONS OF THE NORTHEAST KINGDOM ON FRIDAY. COVERAGE OF SHOWERS WILL BE LIMITED DUE TO DRYING NW FLOW DEVELOPING AS SFC HIGH PRESSURE BUILDS IN OVER SERN CANADA. 500 MB HT LEVEL INCREASES NOTICEABLY OVER THE WEEKEND...RESULTING IN DRY FORECAST. AS THE RIDGE CRESTS OVER THE REGION SATURDAY...S/SW FLOW WILL RETURN...FILTERING WARMER AIR. THIS WILL RESULT IN WARMING TREND...WITH MAX TEMPS FRIDAY AND SATURDAY RANGING FROM L60S TO L80S. TEMPERATURES INCREASE DURING THE WEEK WITH MAXES REACHING THE L80S IN THE VALLEYS. MIN TEMPERATURES WILL BE IN THE M50S IN THE MTNS AND U50S TO L60S IN THE VALLEYS. MONDAY MAY BE THE LAST COMPLETELY DRY DAY AS UPPER TROUGH APPROACHES FROM THE WEST. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... THROUGH 12Z WEDNESDAY...MORNING IFR/LIFR FOG WILL DISSIPATE BY 14Z AT KMPV/KMSS AND KSLK. VFR LOW AND MID LEVEL CLOUDS WILL INCREASE FROM THE WEST AS A COLD FRONT APPROACHES THE REGION. SCATTERED SHOWERS AND A FEW THUNDERSTORMS ARE FORECAST TO DEVELOP GENERALLY FROM WEST TO EAST AS THE FRONT MAKES ITS WAY ACROSS THE REGION. THIS WILL RESULT IN A CHANCE FOR -SHRA AT KMSS STARTING BTWN 13Z-15Z...14Z-17Z AT KSLK AND THE CPV...17Z-20Z FOR KMPV AND KRUT. SCT SHOWERS AND PSBL STORMS WILL PERSIST INTO THE EARLY EVENING HOURS. ANY STORM WILL HAVE THE POTENTIAL FOR GUSTY WINDS...HEAVY DOWNPOURS AND SMALL HAIL...CREATING PERIODS OF MVFR/IFR. AS THE AFOREMENTIONED FRONT MOVES OVER THE NORTH COUNTRY...S/SW WINDS AT 5-10KTS WILL SHIFT MORE W/NW. BEHIND THE FRONT...WINDS WILL SUBSIDE TO 2-6KTS TUESDAY EVENING. CLOUDS WILL DISSIPATE...ALLOWING FOR PSBL BR/FG DEVELOPMENT...ESP AT KMPV AND KSLK. OUTLOOK 12Z WEDNESDAY THROUGH SATURDAY... 12Z WEDNESDAY THROUGH 12Z FRIDAY...PREDOMINANTLY VFR ALTHOUGH A CHANCE OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS EACH AFTERNOON AND EVENING...ALONG WITH THE POTENTIAL FOR IFR/LIFR FOG/BR DEVELOPMENT EACH NIGHT...MAINLY MPV/SLK. 12Z FRIDAY ONWARD...VFR UNDER BUILDING HIGH PRESSURE...HOWEVER PERIODS OF IFR IN FOG/BR POSSIBLE AT NIGHT...AGAIN MAINLY MPV/SLK. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...BANACOS NEAR TERM...NASH SHORT TERM...BANACOS LONG TERM...KGM AVIATION...KGM
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
650 PM EDT TUE AUG 5 2014 .SYNOPSIS... TROPICAL STORM BERTHA WILL LIFT OFF TO THE NORTHEAST TONIGHT AND WEDNESDAY. A COLD FRONT WILL DROP THROUGH THE AREA ON THURSDAY THEN REMAINED STALLED TO THE SOUTH THROUGH THE WEEKEND INTO EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... AS OF 645 PM TUESDAY...WIDELY SCATTERED SHOWERS HAVE DEVELOPING OVER THE SOUND COUNTIES AND A FEW OF THESE SHOWERS ARE STARTING TO MAKE THEIR WAY TOWARD THE COAST. PRECIPITABLE WATER ACROSS THE CWA STILL RANGES FROM 1.6 TO 2 INCHES SO THESE SHOWERS WILL PUT DOWN A DECENT AMOUNT OF RAIN IN A SHORT PERIOD OF TIME. THE 3KM HRRR DOES A GOOD JOB AT DEPICTING THE BASIC LOCATION OF THESE SHOWERS AND ALONG WITH THE RAP AND NAM12...SHOWS ACTIVITY WANING WITH LOSS OF HEATING BY 02Z OR SO. REMAINDER OF THE NIGHT WILL BE WARM WITH PATCHY DENSE FOG...ESPECIALLY INLAND. LOWS WILL GENERALLY BE IN THE UPPER 60S/LOW 70S. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/... AS OF 3 PM TUE...BROAD UPPER TROUGH CONTINUES ACROSS THE AREA WED AND OVERALL QUIET DAY EXPECTED FOR ENC. WILL MAINTAIN SC POP FOR SEABREEZE ACTIVITY DURING THE AFTERNOON HOURS...THINKING ACTIVITY WILL BE FAIRLY ISOLATED. LOW LEVEL THICKNESS VALUES AND 850MB TEMPS SUPPORT HIGHS IN THE MID 80S TO LOWER 90S. && .LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/... AS OF 300 PM TUESDAY...MODELS IN DECENT AGREEMENT MOST OF PERIOD WITH SERIES OF SHRT WVS MOVING THROUGH BROAD EASTERN TROF. INITIAL SHRT WV WILL PUSH A WEAK FRONT THROUGH AREA WED NIGHT AND THU WITH SCT CONVECTIVE ACTIVITY PSBL. BRIEF DRYING PERIOD WILL FOLLOW THU NIGHT AND FRIDAY WITH ONLY MINIMAL POPS. SOME MODEL DIFFERENCES IN DETAILS OVER WEEKEND...BUT GENERAL AGREEMENT ON PSBL WEAK DAMMING EVENT SAT-MON WITH SHRT WV ENERGY INDUCING SFC WV DEVELOPMENT ALONG STALLED FRONTAL BNDRY JUST S OF AREA WITH HIGH PRES EXTENDING INTO AREA FROM N. LEANED TO A WPC/GFS/ECMWF BLEND INDICATING HIGHEST POPS AROUND 50% SAT INTO SUN NIGHT...DECREASING TO CLIMO 20/30 POPS MON-TUE AS MAIN SFC WAVES MOVES OFFSHORE. TEMPS WILL BE NEAR NORMAL FOR WED NIGHT AND THU...THEN SEVERAL DEGS BELOW NORMAL REST OF PERIOD. HIGH TEMPS MAY NOT REACH 80 SOME AREAS OVER WEEKEND IF PCPN WITH DAMMING IS MORE WDSPRD. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... SHORT TERM /THROUGH 18Z WEDNESDAY/... AS OF 645 PM TUESDAY...FOR THE FIRST TIME IN A FEW TIMES...VFR CONDITIONS BEING REPORTED AT ALL TAF SITES. THE PRECIPITATION WILL REMAIN EAST OF THE SITES THIS EVENING BEFORE DISSIPATING. CONFIDENCE IS HIGH IN WIDESPREAD MVFR/IFR FOG LATE TONIGHT WITH ENOUGH RESIDUAL GROUND MOISTURE...COUPLED WITH LIGHT WINDS. SURFACE CONDENSATION PRESSURE DEFICIT LOOKS TO BE THE MOST FAVORABLE AT KEWN AND WILL LOWER VSBYS TO ABOUT ONE MILE THERE WITH 2 MILES AT THE OTHER SITES FROM GENERALLY 09Z TO 12Z. VFR CONDITIONS SHOULD PREVAIL FOR MOST OF THE DAY WEDNESDAY. AS OF 200 PM TUESDAY... VFR CONDITIONS WILL EVENTUALLY PREVAIL AT ALL TAF SITES THROUGH THE AFTERNOON/EVENING HOURS AS FRONTAL BOUNDARY MOVES OFFSHORE. SOME RESIDUAL MVFR CEILINGS EXIST AT PGV/ISO AND SHOULD DISSIPATE QUICKLY WITH PEAK DAYTIME HEATING. A CHANCE FOR A SHOWER STILL EXISTS THROUGH ABOUT 00Z BUT POTENTIAL SHOULD DECREASE WITH LOSS OF DIURNAL HEATING. THROUGH THE OVERNIGHT...A MOIST BOUNDARY LAYER SHOULD DECOUPLE WITH CALM WINDS...SATURATED GROUND...AND GENERALLY CLEAR SKIES...HIGHLY CONFIDENT IN REDUCED MVFR/IFR VISIBILITIES BEGINNING AROUND 06Z. AFTER SUNRISE...DAYTIME HEATING WILL ALLOW LOW LEVELS TO MIX OUT AND RETURN TO VFR CONDITIONS. LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... AS OF 300 PM TUESDAY...PREVAILING VFR EXPECTED WED NIGHT THROUGH FRI NIGHT OUTSIDE OF ISOLD/SCT CONVECTIVE ACTIVITY. WDSPRD SUB-VFR PSBL SAT-SUN WITH DAMMING EVENT BUT CONFIDENCE ONLY MODERATE AT THIS TIME. && .MARINE... SHORT TERM /THROUGH WEDNESDAY/... AS OF 650 PM TUESDAY...WINDS GENERALLY N/NE AT 5 TO 10 KNOTS AND SHOULD BACK TO MORE NW TOWARD MORNING PER LATEST 3KM HRRR/NAM12 WIND FORECAST. SEAS CONTINUES IN THE 4-7 FOOT RANGE WITH 11-12 SECOND SWELLS FROM DISTANT HURRICANE BERTHA. SEAS WILL GRADUALLY SUBSIDE OVERNIGHT INTO WED AS BERTHA LIFTS NE...AND LONG PERIOD SWELL SUBSIDES. ONLY CHANGE TO FORECAST WAS TO EXTEND SCA A FEW HOURS FOR WATERS BASED ON LATEST WAVEWATCH AND NWPS GUIDANCE. BACKING WINDS WED...NW EARLY BECOMING S/SW DURING THE AFTERNOON. LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... AS OF 300 PM TUESDAY...SW WINDS WILL INCREASE TO 10-15 KT AHEAD OF COLD FRONT WED NIGHT INTO EARLY THU...THEN SHIFT TO NE THU NIGHT INTO FRI WITH HIGH PRESSURE BUILDING IN BEHIND FRONT. WINDS WILL GRADUALLY VEER AROUND TO E AND SE OVER WEEKEND WITH SPEEDS MAINLY 15 KT OR LESS AS SFC LOW PRES MOVES ACROSS STALLED FRONTAL BNDRY TO S. BLEND OF WW3..NWPS AND PREVIOUS FCST FOR SEAS DURING PERIOD. HEIGHTS HOLDING AROUND 3-4 FT WITH PRE AND POST FRONTAL FLOW INTO FRIDAY...THEN MAINLY 2-3 FT SAT-SUN. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT WEDNESDAY FOR AMZ150-152- 154. SMALL CRAFT ADVISORY UNTIL 8 AM EDT WEDNESDAY FOR AMZ156-158. && $$ SYNOPSIS...CQD NEAR TERM...CTC SHORT TERM...CQD LONG TERM...JBM AVIATION...JBM/CTC MARINE...JBM/CTC/CQD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
209 PM EDT TUE AUG 5 2014 .SYNOPSIS... A STALLED FRONT ALONG THE COAST WILL MOVE OFFSHORE TODAY AS TROPICAL STORM BERTHA MOVES PASSES WELL OFFSHORE OF THE CAROLINA COAST. SWELLS FROM BERTHA WILL LEAD TO AN INCREASED RIP CURRENT RISK ALONG AREA BEACHES THE NEXT SEVERAL DAYS. WARM AND MUGGY WEATHER IS EXPECTED WEDNESDAY AND THURSDAY AHEAD OF AN APPROACHING COLD FRONT. HIGH PRESSURE WILL BUILD IN FRIDAY THROUGH THE WEEKEND...LIKELY HOLDING TEMPERATURES DOWN A FEW DEGREES BELOW NORMAL. && .NEAR TERM /THROUGH TONIGHT/... AS OF 945 AM TUESDAY...LATEST RADAR TRENDS CONTINUE TO ILLUSTRATE BEST CHANCE FOR PCPN TO OCCUR ACROSS COASTAL COUNTIES. THE SMALL LOW LEVEL CIRCULATION OVER THE OFFSHORE WATERS SSE OF CAPE FEAR...WILL CONTINUE TO PULL SLOWLY NE...AWAY FROM THE MAINLAND THIS AFTERNOON AND TONIGHT...TAKING THE PCPN WITH IT. ACROSS THE INLAND COUNTIES...DRIER AIR BEGINNING TO OVERSPREAD THIS AREA VIA LATEST WATER VAPOR IMAGERY TRENDS...ALONG WITH WEAK SUBSIDENCE BECOMING MORE WIDESPREAD. A FEW POPCORN TYPE DIURNALLY DRIVEN SHRA/TSRA STILL REMAINS POSSIBLE DURING THIS AFTERNOON/EARLY EVENING. OVERALL...WILL CONTINUE WITH THE DECREASING POP TREND THRU THIS AFTN AND EVENING. MAY NEED TO RE-VISIT AND INCREASE MAX TEMPS FOR AREAS ALONG AND WEST OF THE I-95 CORRIDOR AT THE NEXT UPDATE DUE TO ADDITIONAL INSOLATION REACHING THE SFC THEN PREVIOUSLY THOUGHT. PREVIOUS DISCUSSION................................. AS OF 645 AM TUESDAY...RADAR REVEALS A GROWING AREA OF RAIN WITH EMBEDDED CONVECTIVE ELEMENTS 30-100 MILES SOUTH AND SOUTHEAST OF CAPE FEAR...BUT A LONG RADAR LOOP REVEALS THE MAJORITY OF THE FORECAST AREA MAY BE TOO FAR WEST TO GET IN ON THIS PRECIPITATION. THE EXCEPTION IS GOING TO BE THE COASTAL CAPE FEAR REGION WHERE I HAVE NUDGED POPS UP TO AS HIGH AS 80 PERCENT IN THE SOUTHPORT-BALD HEAD ISLAND AREA. A WELL-DEFINED CIRCULATION IN RADAR IMAGERY ABOUT 60 MILES SOUTH OF OAK ISLAND APPEARS TO BE THE WESTERN ANCHOR POINT FOR THIS RAINFALL...AND DETERMINING THE PATH OF THIS FEATURE IS INSTRUMENTAL TO MAKING AN ACCURATE RAINFALL FORECAST. THE HRRR MAKES AN ATTEMPT TO INITIALIZE THE CIRCULATION AND ADVECTS IT NORTHEASTWARD...PASSING APPROXIMATELY 20 MILES EAST OF CAPE FEAR BETWEEN 16-17Z. ON THIS PATH THE BULK OF THE RAIN WILL REMAIN OVER THE OCEAN WITH THE WETTEST WEATHER EXPECTED ON LAND BETWEEN NOW AND NOON. OTHER THAN CHANGES TO SKY COVER AND POPS/PRECIP AMOUNT...THE ONLY OTHER SIGNIFICANT CHANGE WITH THE FORECAST WAS TO INCREASE THE COVERAGE OF FOG ACROSS THE INTERSTATE 95 CORRIDOR. VISIBILITIES HAVE GONE AS LOW AS 1/4 MILE IN SPOTS ALTHOUGH PREVAILING VISIBILITIES ARE HIGHER ACROSS THE REGION. A SPECIAL WEATHER STATEMENT HAS BEEN ISSUED ADDRESSING THE FOG. PREVIOUS DISCUSSION FROM 300 AM FOLLOWS... WE ARE JUST ABOUT TO GET RID OF THE DREARY WEATHER PATTERN THAT HAS BROUGHT UNSEASONABLY COOL...CLOUDY AND RAINY WEATHER TO THE COASTAL CAROLINAS FOR THE ENTIRE MONTH SO FAR. SO FAR AUGUST 2014 HAS SEEN THE 7TH COOLEST TEMPERATURES EVEN OBSERVED IN WILMINGTON WITH AN AVERAGE TEMPERATURE OF ONLY 75.7 DEGREES. HURRICANE BERTHA IS PASSING WELL EAST OF THE CAROLINAS WITH NO DIRECT IMPACTS ON OUR WEATHER TODAY. THE OLD STALLED FRONT APPEARS TO LIE ALONG THE BEACHES OF PENDER AND NEW HANOVER COUNTIES... EXTENDING SOUTHWARD FROM SOUTHPORT TO AN AREA OF LOW PRESSURE OFF THE GEORGIA COAST. THIS FEATURE SHOULD BE DRAWN EASTWARD BEHIND BERTHA TODAY...WITH DRIER AIR GRADUALLY BUILDING IN FROM THE NORTH WITH TIME. RADAR SHOWS PLENTY OF SHOWERS ACROSS THE COASTAL WATERS. THESE ARE SHALLOW CONVECTIVE FEATURES WITH ECHO TOPS GENERALLY 20KFT OR LESS...EXCEPT FOR A FEW T-STORMS FARTHER OFFSHORE WITH TOPS OVER 30KFT. SINCE THE BULK OF THIS ACTIVITY IS SHALLOW IT IS BEING STEERED BY THE 700-850 MB MEAN FLOW WHICH IS CURRENTLY FROM THE EAST. THE 00Z GFS AND 06Z RUC (OUR PREFERRED MODELS TODAY) SHOW THIS STEERING FLOW BACKING MORE NORTHERLY WITH TIME WHICH SHOULD TEND TO LIMIT HOW FAR INLAND ANY SHOWER ACTIVITY WILL MOVE. FORECAST POPS RANGE FROM 30-50 PERCENT ALONG THE COAST THIS MORNING...DIMINISHING TO 20-30 PERCENT BY NOON. FOR INTERIOR SECTIONS OF THE EASTERN CAROLINAS UNLESS AN ISOLATED SHOWER CAN DEVELOP DURING THE AFTERNOON DRY WEATHER IS EXPECTED. HIGHS SHOULD RANGE FROM THE UPPER 80S TO NEAR 90 ACROSS THE SC PEE DEE REGION TO THE MID 80S AT THE COAST. FOR TONIGHT DRY AIR SHOULD FLOOD IN THROUGHOUT THE TROPOSPHERE WITH PRECIPITABLE WATER VALUES FALLING TO LESS THAN 1.5 INCHES. SKIES SHOULD BECOME MAINLY CLEAR BY EARLY EVENING AND THERE IS LITTLE POTENTIAL FOR FOG OR LOW STRATUS OVERNIGHT. LOWS SHOULD TO NEAR 70. && .SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 AM TUESDAY...SUMMER RETURNS ON WEDNESDAY AS THE MID LEVEL FLOW GOES WESTERLY AND DOWNSLOPE ALLOWING FOR A PARTLY SUNNY AFTERNOON. PIEDMONT TROUGH DEVELOPS BUT IT ALONG WITH THE SEA BREEZE WILL GENERALLY BE TOO MOISTURE-DEPRIVED TO LEAD TO MEANINGFUL PRECIP CHANCES. AFTERNOON TEMPERATURES WILL BE NEAR OR A FEW DEGREES ABOVE CLIMO. PIEDMONT TROUGH PUSHES TOWARDS THE COAST ON THURSDAY WHILE A MID LEVEL SHORTWAVE PASSES OVERHEAD LATE IN THE AFTERNOON. NORMALLY THIS WOULD BE A GOOD SETUP FOR THUNDERSTORMS. HOWEVER THERE IS STILL VERY LITTLE MOISTURE ESPECIALLY THROUGH THE MID LEVELS. CONVECTION WILL BE LIMITED AND GENERALLY BE CONFINED TO THE COASTAL REGIONS. TEMPERATURES WILL BE QUITE SIMILAR TO THOSE OF WEDNESDAY. A COLD FRONT WILL ENTER THE REGION LATE THURSDAY NIGHT AND WILL KEEP ISOLATED SHOWERS AND THUNDERSTORMS IN THE FORECAST. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 3 AM TUESDAY...HIGH PRESSURE BUILDING IN FROM THE NORTH BEHIND THURSDAY NIGHT COLD FRONT TO END THE BRIEF SHORT TERM PERIODS SUMMER TEMPS. MOISTURE MAY POOL ALONG THE FRONT AND BRING SOME SLIGHT RAIN CHANCES OVER SWRN ZONES. THIS WILL HOLD TRUE INTO SATURDAY AS THE FRONT WASHES BACK CLOSER TO THE AREA...THE LOW RAIN CHANCES MAY INCREASE IN AREA WHILE AFTERNOON HIGHS REMAIN CAPPED BELOW CLIMO. SUNDAY IS WHEN RAIN CHANCES SHOULD RETURN AREA-WIDE AS THE FRONT LIFTS BACK INTO THE REGION. WAVE MOVES BY LATE SUNDAY INTO SUNDAY NIGHT POSSIBLY FURTHER RAMPING UP RAIN CHANCES...AND THEN LEAVING THE BOUNDARY IN OUR PRESENCE SANS WAVE ON MONDAY. CYCLONIC AND NWRLY MID LEVEL FLOW CONTINUES ON TUESDAY WITH SURFACE TROUGHINESS REDEVELOPING. RAIN CHANCES WILL LINGER INTO TUESDAY WITH CLIMO OR HIGHER CHANCES WHILE TEMPS REMAIN NEAR OR JUST SHY OF CLIMO. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... AS OF 18Z...VFR CONDITIONS THRUOUT EXCEPT OVERNIGHT WHEN MVFR AND/OR IFR CONDITIONS POSSIBLY COULD OCCUR FROM REDUCED HORIZONTAL VSBY FROM FOG. WILL KEEP VCNTY SHRA/TSRA THIS AFTERNOON/EARLY EVENING...HOWEVER SUBSIDENCE ALOFT WILL HELP KEEP THE POPCORN TYPE CONVECTION FROM DEVELOPING ANY FURTHER IN THE VERTICAL. THUS...WILL CONTINUE WITH VCSH OR VCTS WHERE APPROPRIATE UNTIL SUNSET. FOR TONIGHT...WINDS BECOME CALM FOLLOWED BY A CHANCE FOR MVFR/IF FOG AFTER 05Z. STAYED WITH BR ALL TERMINALS BUT NEXT UPDATE WILL NEED TO FOCUS FOR POSSIBLE LIFR FROM DENSE FOG. FOR WEDNESDAY...SCT TO BKN CU CLOUD DECK POSSIBLE BY LATE MORNING. ANY FOG SHOULD DISSIPATE BY 13Z AT THE LATEST. EXTENDED OUTLOOK...ISOLATED SHOWERS WEDNESDAY AND THURSDAY. SCATTERED SHOWERS FRIDAY WITH SHOWERS LIKELY ON SATURDAY AND SUNDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 945 AM TUESDAY...SMALL CRAFT ADVISORY RAISED FOR THE ILM NC WATERS...DUE TO SEAS. SMALL CRAFT EXERCISE CAUTION DUE TO SEAS FOR THE ILM SC WATERS. BOTH WILL EXPIRE AT 900 PM THIS EVENING. BERTHA SWELLS NOW AFFECTING THE AREA WATERS...AND RUNNING HIGHER ACROSS THE ILM NC WATERS FROM CAPE FEAR NORTHWARD COMPARED TO THE REMAINING WATERS FROM SOUTH OF CAPE FEAR TO SOUTH SANTEE RIVER. FOR THE ILM NC WATERS...LATEST 41110 BUOY REPORTING SIGNIFICANT SEAS UP TO 5 FT...AND THE OFFSHORE BUOY 41036 REPORTING 8+ FT. BOTH BUOYS INDICATE SIG. SEAS PREDOMINATELY FROM BERTHA SWELL. PERIODS RANGE FROM 11 TO 14 SECONDS. FOR THE ILM SC WATERS...LATEST EDISTO BUOY REPORTED UP TO 7 FT SIG. SEAS...WITH WIND DRIVEN WAVES A BETTER CONTRIBUTING THEN WHATS OCCURRING ACROSS THE ILM NC WATERS. FOR WINDS...THE PROGGED SFC PRESSURE PATTERN AND GRADIENT AFTER THE DEPARTING LOW LEVEL CIRCULATION CURRENTLY MOVING FURTHER OFFSHORE FROM CAPE FEAR...WILL YIELD N TO NE WINDS AT 10-15 KT THIS AFTERNOON...BACKING TO NW TO NNW AT 10 KT DURING TONIGHT. PREVIOUS DISCUSSION................................... AS OF 645 AM TUESDAY...A CYCLONIC CIRCULATION IN RADAR IMAGERY LOCATED ABOUT 60 MILES SOUTH OF OAK ISLAND IS THE FEATURE TO WATCH THIS MORNING. THE LATEST HRRR MODEL SEEMS TO HAVE INITIALIZED THIS SWIRL AND MOVES IT SLOWLY NORTHEASTWARD...MISSING THE TIP OF CAPE FEAR ABOUT 20 MILES TO THE EAST BETWEEN NOON AND 1 PM EDT. LACK OF MARINE OBSERVATIONS WEST OF THE LOW IS HINDERING ANALYSIS...BUT NOAA BUOY 41004 EAST OF CHARLESTON HAS NOT GUSTED ANY HIGHER THAN 17 KNOTS IN THE PAST FEW HOURS. WAVE HEIGHTS AT THE LOCAL BUOYS HAVE CHANGED LITTLE FROM 3 AM AND NO CHANGES ARE NEEDED THERE. PREVIOUS DISCUSSION FROM 300 AM FOLLOWS... AN OLD STALLED FRONT RUNS ALONG THE BEACHES OF SE NORTH CAROLINA SOUTHWARD INTO AN AREA OF LOW PRESSURE OFF THE GEORGIA COAST. HURRICANE BERTHA IS WELL EAST OF THE CAROLINAS AND WILL MOVE NORTHEASTWARD AND FARTHER AWAY TODAY. THE GEORGIA LOW AND OUR FRONT SHOULD BE DRAWN OFFSHORE TOWARD BERTHA...LEADING TO A DRYING TREND DEVELOPING WITH TIME. UNTIL THEN...WAVES OF SHOWERS AND EMBEDDED T-STORMS ACROSS THE COASTAL WATERS SHOULD CONTINUE THROUGH THE MORNING HOURS. GENERALLY EAST OR NORTHEAST WINDS WILL TURN NORTHERLY THIS EVENING...THEN WESTERLY OVERNIGHT AS BERTHA PULLS THE LOW AND FRONT AWAY FROM THE AREA. THIS WILL LET DRIER AIR FLOOD INTO THE AREA. A SIGNIFICANT SWELL FROM BERTHA WILL IMPACT THE WATERS TODAY AND SHOULD BE THE LARGEST CONTRIBUTING FACTOR IN SEA HEIGHT FORECASTS TODAY. SEAS OF 4-5 FEET ARE EXPECTED...DIMINISHING TO 3-4 FT LATE TONIGHT. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 AM TUESDAY...PIEDMONT TROUGH ON WEDNESDAY WILL BACK INITIALLY WEST FLOW TO SOUTHWEST OR EVEN SOUTH WHILE ADDING A FEW KNOTS TO AVERAGE SPEED. SEAS MAINLY COMPRISED OF WIND WAVES IN THE 2 TO 3 FT RANGE. AS THE BOUNDARY MOVES TOWARDS THE COAST ON THURSDAY THE WIND WILL DIMINISH LATER IN THE DAY AS THE GRADIENT IS PUSHED OUT TO SEA BY THE TROUGH. THE BOUNDARY WILL SINK SOUTH ACROSS THE ZONES RATHER SLOWLY LATE THURSDAY NIGHT BRINGING A TURN TO NORTHERLY WINDS FOLLOWED BY ADDITIONAL VEERING TO EASTERLY BY THE PERIODS END...AT LEAST FOR NORTHERN ZONES. LONG TERM /FRIDAY THROUGH SATURDAY/... AS OF 3 AM TUESDAY...POST-FRONTAL ONSHORE FLOW ON FRIDAY WILL BE IN THE 10 TO 15 KT RANGE EARLY BUT SETTLE BY ABOUT 5 KT. SEAS WILL BE RUNNING JUST 2-3 FEET THEN MOST AREAS. THE HIGH WILL CONTINUE WEDGING IN FROM POINTS NORTH INTO SATURDAY WHILE THE FRONT STALLED TO THE SOUTH TRIES TO MOVE BACK TO THE NORTH SLIGHTLY. WITH RELATIVELY UNCHANGED WINDS AND NO SWELL ENERGY TO SPEAK OF SEAS WILL REMAIN 2 FEET AGAIN ON SATURDAY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...HIGH RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR SCZ054- 056. NC...HIGH RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR NCZ106- 108-110. MARINE...SMALL CRAFT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR AMZ250- 252. && $$ SYNOPSIS...MBB NEAR TERM...DCH/TRA SHORT TERM...MBB LONG TERM...MBB AVIATION...DCH
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
322 PM EDT TUE AUG 5 2014 .SYNOPSIS... A WEAK COLD FRONT WILL PUSH ACROSS THE STATE THIS AFTERNOON AND EVENING. A STRONGER COLD FRONT WILL MOVE THROUGH THE COMMONWEALTH WEDNESDAY FOLLOWED BY COOLER AND LESS HUMID CONDITIONS THAT WILL LAST INTO THIS UPCOMING WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... DEEP MOISTURE CONVERGENCE AND CAPES IN THE 1000-15000J RANGE OVER NORTHERN PA IS RESULTING IN SHOWERS AND THUNDERSTORMS BREAKING OUT MAINLY NORTH OF I-80. HRRR SEEMS A LITTLE SLOW IN CONVECTIVE INITIATION...BUT SEEMS TO HAVE THE MODE CORRECT AND SUPPORTS THE NEAR TERM IDEA OF KEEPING CONVECTION MAINLY OVER THE NORTHERN HALF OFMY FCST AREA. CROSS SECTIONS THROUGH THE STORMS SHOWS SOME ELEVATED CORES IN SOME OF THE MORE ROBUST UPDRAFTS...MEANING SOME GUSTY WINDS CANNOT BE RULED OUT IN A FEW STORMS. BUT THE OVERALL SEVERE THREAT SHOULD STAY MINIMAL TODAY WITH MOST STORMS BEING PULSE TYPES AND LACKING OVERALL ORGANIZATION. SHOWER ACTIVITY IS EXPECTED TO FADE WITH THE LOSS OF THE SUN AS ALL INDICATORS SHOW INSTABILITY DWINDLING QUICKLY. I KEPT A SMALL MENTION OF PRECIP OVER NORTHERN AREAS EVEN AFTER MIDNIGHT AS THE SECOND STRONGER COLD FRONT TAKES SHAPE AS IT DROPS INTO THE LOWER LAKES LATER TONIGHT. OVERNIGHT LOWS FROM THE MOD 50S TO MID 60S NW TO SE WILL BE VERY NEAR SEASONAL NORMS. && .SHORT TERM /WEDNESDAY/... WEDNESDAY...A VIGOROUS UPPER JET STREAK IS MADE TO DIVE INTO SWRN PA DURING THE AFTERNOON. MODELS GENERATE STRONG SHEAR AND A RESPECTABLE AMOUNT OF CAPE ON AND TO THE LEFT OF THE NOSE OF THIS UPPER JET STREAK. INSTABILITY AS ALWAYS WILL DEPEND ON HOW MUCH SUN WE CAN MANAGE...BUT ISOLATED SEVERE STORMS CANNOT BE RULED OUT FROM MID MORNING INTO THE AFTERNOON HOURS AS THE SECONDARY COLD FRONT SAGS SOUTH. RIGHT NOW WE ARE IN A GENERAL THUNDER OUTLOOK FROM SPC...BUT WOULD NOT BE SURPRISED IF WE ARE ELEVATED TO A SLIGHT RISK GIVEN YET ANOTHER ANOMALOUSLY STRONG SYSTEM MOVING INTO THE AREA. RIGHT NOW I HAVE TEMPS DIALED A NOTCH BELOW TODAY`S READINGS GIVEN THE EXPECTATIONS OF MORE CLOUDS AND SHOWER ACTIVITY. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... QUALITY/REFRESHING LOW PWAT AIRMASS BEING DIRECTED EQUATORWARD VIA NLY FLOW BEHIND REINFORCING COLD FRONT WILL BRING AN END TO SCT SHOWER/TSTM ACTIVITY ACROSS THE SRN TIER ZONES EARLY WED NGT. LG SCALE FORCING ON SW FRINGE OF SLOWLY PROGRESSING MID-UPPER LVL TROUGH MOVG EWD ACRS INTERIOR NEW ENGLAND/NORTHEAST STATES...ALONG WITH ACCOMPANYING PLUME OF RELATIVELY STEEP MID-LVL LAPSE RATES NEAR 6 C/KM ASSOCD WITH -15C AT 500MB AND ANOMALOUS H7 TEMPS MAY INITIATE A FEW INSTABILITY SHOWERS OVER NRN-NERN SXNS ON THU. GRIDDED SKY COVER MAY NEED TO BE ADJUSTED UPWARD AS THE SET-UP APPEARS FAVORABLE FOR AT LEAST A BKN CU FIELD TO DVLP BY AFTN. OTHERWISE..EXPECT A RATHER PLEASANT DAY WITH COMFORTABLE HUMIDITY AND 5-10KT NNW WIND. SHORTWAVE RIDGING AND 500MB HEIGHT RISES SHOULD GRADUALLY REPLACE THE DEPARTING UPPER TROUGH/CYC FLOW ALOFT OVER THE REGION FRI- SUN. AT THE SFC...HIGH PRESSURE MIGRATING S/SEWD FROM THE UPPER GRT LKS/SERN CANADA SHOULD PROVIDE A STRING OF DRY WX WITH PLEASANT DAYS AND RELATIVELY COOL NGTS. 05/12Z MODELS ARE IN DECENT AGREEMENT IN KEEPING THE MAIN AXIS OF PCPN SOUTH OF PA ALONG A NW/SE ORIENTED FRONTAL ZONE/INVERTED TROUGH AXIS LOCATED FROM THE MID MO/LWR OH VLYS INTO THE SRN/CNTRL APPLCHNS AND SRN MID-ATLC/SE STATES. THE PCPN PATTERN SHOULD BECOME MORE UNSETTLED INTO THE MIDDLE OF NEXT WEEK WITH INCR MSTR/SLY WINDS CONSISTENT WITH RETURN FLOW ON BACKSIDE OF DEPARTING HP...WITH A FRONTAL SYSTEM APPROACHING THE AREA FROM THE NW. CONSENSUS BLEND OF THE LATEST OPERATIONAL AND ENSEMBLE GUIDANCE FAVORS NEAR TO SLIGHTLY BELOW NORMAL TEMPS DURING THE PERIOD. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... ALL TERMINALS ARE VFR AND THIS WILL CONTINUE INTO THE EVENING. EXCEPTIONS WILL BE WHERE DEVELOPING CONVECTION WANDERS INTO TERMINAL AIRSPACE THROUGH LATE AFTERNOON. THE BEST CHANCE OF THIS WILL BE OVER THE FAR NORTH IN AND AROUND BRADFORD...AND POSSIBLYINTO WILLIAMSPORT AFTER 20Z. SHOWERS AND THUNDERSTORMS WILL TEND TO FADE AS WE LOSE THE SUN. LOCAL MVFR/IFR RESTRICTIONS WILL BECOME POSSIBLE ONCE AGAIN TONIGHT WITH THE FORMATION OF AREAS OF LOW CLOUDS AND FOG. A STRONGER COLD FRONT WILL BRING A BETTER CHANCE OF RESTRICTIONS ASSOCIATED WITH WIDESPREAD SHOWERS AND THUNDERSTORMS WEDNESDAY. DRIER AIR AND IMPROVING CONDITIONS WILL TEND TO WORK IN FROM THE NORTH LATER IN THE DAY. OUTLOOK... THU-SAT...MAINLY VFR. PATCHY FOG/LOW CLOUDS POSSIBLE EARLY. SUN...MAINLY VFR BUT WITH ISOLATED SHOWERS AND THUNDERSTORMS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...STEINBUGL AVIATION...LA CORTE/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
222 PM EDT TUE AUG 5 2014 .SYNOPSIS... A WEAK COLD FRONT WILL PUSH ACROSS THE STATE THIS AFTERNOON AND EVENING. A STRONGER COLD FRONT WILL MOVE THROUGH THE COMMONWEALTH WEDNESDAY FOLLOWED BY COOLER AND LESS HUMID CONDITIONS THAT WILL LAST INTO THIS UPCOMING WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... DEEP MOISTURE CONVERGENCE AND CAPES IN THE 1000-15000J RANGE OVER NORTHERN PA IS RESULTING IN SHOWERS AND THUNDERSTORMS BREAKING OUT MAINLY NORTH OF I-80. HRRR SEEMS A LITTLE SLOW IN CONVECTIVE INITIATION...BUT SEEMS TO HAVE THE MODE CORRECT AND SUPPORTS THE NEAR TERM IDEA OF KEEPING CONVECTION MAINLY OVER THE NORTHERN HALFOF MY FCST AREA. CROSS SECTIONS THROUGH THE STORMS SHOWS SOME ELEVATED CORES IN SOME OF THE MORE ROBUST UPDRAFTS...MEANING SOME GUSTY WINDS CANNOT BE RULED OUT IN A FEW STORMS. BUT THE OVERALL SEVERE THREAT SHOULD STAY MINIMAL TODAY WITH MOST STORMS BEING PULSE TYPES AND LACKING OVERALL ORGANIZATION. SHOWER ACTIVITY IS EXPECTED TO FADE WITH THE LOSS OF THE SUN AS ALL INDICATORS SHOW INSTABILITY DWINDLING QUICKLY. I KEPT A SMALL MENTION OF PRECIP OVER NORTHERN AREAS EVEN AFTER MIDNIGHT AS THE SECOND STRONGER COLD FRONT TAKES SHAPE AS IT DROPS INTO THE LOWER LAKES LATER TONIGHT. OVERNIGHT LOWS FROM THE MOD 50S TO MID 60S NW TO SE WILL BE VERY NEAR SEASONAL NORMS. && .SHORT TERM /WEDNESDAY/... WEDNESDAY...A VIGOROUS UPPER JET STREAK IS MADE TO DIVE INTO SWRN PA DURING THE AFTERNOON. MODELS GENERATE STRONG SHEAR AND A RESPECTABLE AMOUNT OF CAPE ON AND TO THE LEFT OF THE NOSE OF THIS UPPER JET STREAK. INSTABILITY AS ALWAYS WILL DEPEND ON HOW MUCH SUN WE CAN MANAGE...BUT ISOLATED SEVERE STORMS CANNOT BE RULED OUT FROM MID MORNING INTO THE AFTERNOON HOURS AS THE SECONDARY COLD FRONT SAGS SOUTH. RIGHT NOW WE ARE IN A GENERAL THUNDER OUTLOOK FROM SPC...BUT WOULD NOT BE SURPRISED IF WE ARE ELEVATED TO A SLIGHT RISK GIVEN YET ANOTHER ANOMALOUSLY STRONG SYSTEM MOVING INTO THE AREA. RIGHT NOW I HAVE TEMPS DIALED A NOTCH BELOW TODAY`S READINGS GIVEN THE EXPECTATIONS OF MORE CLOUDS AND SHOWER ACTIVITY. && .LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/... LG SCALE FORCING AND COOLER AIR ALOFT/STEEP MID-LVL LAPSE RATES TIED TO PASSAGE OF UPPER LEVEL TROUGH AXIS MAY PROVIDE ENOUGH LIFT TO GENERATE ISOLD...INSTABILITY TYPE SHOWERS ON THU AFTN. OTHERWISE ANTICIPATE A DRY PERIOD THROUGH THE UPCOMING WEEKEND AND INTO EARLY NEXT WEEK...WITH STRING OF PLEASANT DAYS/COMFORTABLE NIGHTS AS AREA REMAINS UNDER THE INFLUENCE OF SFC HIGH PRES MIGRATING S/SEWD FROM THE UPPER GRT LKS. TEMPS WILL START OUT BELOW AVG BEHIND THE DEPARTING TROUGH AXIS BUT SHOULD MODERATE AS HEIGHTS REBOUND BY 10/11 AUG. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... ALL TERMINALS ARE VFR AND THIS WILL CONTINUE INTO THE EVENING. EXCEPTIONS WILL BE WHERE DEVELOPING CONVECTION WANDERS INTO TERMINAL AIRSPACE THROUGH LATE AFTERNOON. THE BEST CHANCE OF THIS WILL BE OVER THE FAR NORTH IN AND AROUND BRADFORD...AND POSSIBILY INTO WILLIAMSPORT AFTER 20Z. SHOWERS AND THUNDERSTORMS WILL TEND TO FADE AS WE LOSE THE SUN. LOCAL MVFR/IFR RESTRICTIONS WILL BECOME POSSIBLE ONCE AGAIN TONIGHT WITH THE FORMATION OF AREAS OF LOW CLOUDS AND FOG. A STRONGER COLD FRONT WILL BRING A BETTER CHANCE OF RESTRICTIONS ASSOCIATED WITH WIDESPREAD SHOWERS AND THUNDERSTORMS WEDNESDAY. DRIER AIR AND IMPROVING CONDITIONS WILL TEND TO WORK IN FROM THE NORTH LATER IN THE DAY. OUTLOOK... THU-SAT...MAINLY VFR. PATCHY FOG/LOW CLOUDS POSSIBLE EARLY. SUN...MAINLY VFR BUT WITH ISOLATED SHOWERS AND THUNDERSTORMS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...LAMBERT/STEINBUGL AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
100 PM CDT TUE AUG 5 2014 .AVIATION 18Z DISCUSSION... SFC RIDGE EXTENDS FROM MIDDLE TN NE THROUGH PA. DEWPOINTS ARE STILL RATHER LOW WITH VALUES HOLDING IN THE 50S. THIS IS MINIMIZING OUR INSTABILITY LEVELS DESPITE THE WARM TEMPS. A FEW EXTRA CLOUDS...HOWEVER...ARE MOVING ACROSS THE AREA THIS AFTERNOON AND THAT SHOULD BE THE EXTENT OF OUR MOISTURE THROUGH THE TAF PD. SOME LIGHT FOG WILL BE POSSIBLE ACROSS THE TAF AREAS AROUND 12Z. OTW...TRANQUIL WEATHER IS EXPECTED ALTHOUGH HUMIDITY LEVELS WILL BE A LITTLE HIGHER TOMORROW. && .PREV DISCUSSION... /ISSUED 941 AM CDT TUE AUG 5 2014/ UPDATE... AREA OF STORMS EXTENDS FROM SOUTHERN IL SW TOWARD THE BOOTHEEL. THIS ACTIVITY IS WEAKENING AND IS NOT EXPECTED TO REACH THE MID STATE. HRRR FURTHER CONCURS WITH THIS SOLUTION SO OTHER THAN SOME INCREASED PARTIAL CLOUDINESS FOR TODAY...CONDITIONS SHOULD REMAIN DRY. OTW...SFC RIDGE STRETCHES FROM THE MID STATE NE TO PA. INSTABILITY CHARTS REVEAL THAT NOT MUCH OF ANY CAPE RETURN IS EXPECTED UNTIL TOMORROW AND THURSDAY. THEREFORE...WITH THE DRY STABLE CONDITIONS IN PLACE...NO POPS WILL BE ADDED TO TODAY`S FCST AT THIS TIME. TEMPS STILL EXPECTED TO REACH THE LOWER 90S FOR MANY AREAS. CURRENT TEMPS ARE IN THE MID TO UPPER 70S AND THIS IS IN LINE WITH THE LATEST NUMERICAL GUIDANCE. SO...ONLY CHANGE TO THE FCST WILL BE A LITTLE ADDED CLOUD COVER TO THE GRIDS. UPDATES WILL BE SENT OUT SHORTLY. PREV DISCUSSION... /ISSUED 601 AM CDT TUE AUG 5 2014/ UPDATE...ADDED AVIATION SECTION FOR 12Z TAF`S. AVIATION...BNA/CKV/CSV...SURFACE HIGH PRESSURE IS CURRENTLY CENTERED JUST EAST OF NASHVILLE, WITH A DRY AIR MASS IN PLACE OVER TENNESSEE AND GENERALLY LIGHT WINDS EXPECTED THE NEXT 24 HRS. WITH THE EXCEPTION OF MORNING RADIATION FOG AT CSV THROUGH 13Z, LOOK FOR VFR WX ACROSS MIDDLE TENNESSEE THROUGH THE TAF PERIOD. PREV DISCUSSION... /ISSUED 339 AM CDT TUE AUG 5 2014/ SHORT TERM...A RIDGE OF SURFACE HIGH PRESSURE, EXTENDING FROM THE VIRGINIAS ACROSS TENNESSEE AND INTO OKLAHOMA, WAS KEEPING SKIES CLEAR OVER THE MID STATE EARLY THIS MORNING. AT 2AM, TEMPERATURES WERE MAINLY IN THE LOWER AND MIDDLE 60S. ATMOSPHERE OVER THE MID STATE SHOULD REMAIN DRY ENOUGH TODAY TO KEEP US LOCKED INTO OUR CURRENT RAIN-FREE PATTERN. WITH MAXIMUM PERCENT SUNSHINE EXPECTED, BELIEVE WE WILL SEE TEMPERATURES SURGE TO THE SAME LEVELS AS YESTERDAY. CSV MAY EVEN BREAK THEIR 3-DAY STREAK OF MAXING OUT AT 83 DEGREES, AND NUDGE ON UP TO 84. YARDS AND GARDENS OVER MANY AREAS ARE NEEDING RAIN PRETTY BADLY AND, FORTUNATELY, WE HAVE REASON TO BE HOPEFUL FOR A GRADUAL CHANGE IN THE WEATHER PATTERN AS WE HEAD INTO THE MIDDLE AND LATTER PART OF THE WEEK. IF WE LOOK TO THE NORTHWEST THIS MORNING, UP OVER EAST- CENTRAL MISSOURI, WE SEE NOCTURNAL TSTMS IN PROGRESS, AND A HINT OF THE CHANGES THAT WILL BE COMING OUR WAY. LOOK FOR EASTERN MISSOURI TO BE A GOOD BREEDING GROUND FOR THUNDERSTORMS OVER THE NEXT 3 TO 5 DAYS, WITH THUNDERSTORMS EVENTUALLY PROPAGATING INTO OUR NECK OF THE WOODS. AS INTERMITTENT SHORTWAVES DROP SOUTHEASTWARD IN NORTHWEST FLOW, AND KICK OFF THUNDERSTORMS AND OUTFLOW BOUNDARIES, AND AS A LOW LEVEL COL CONVERGENCE BOUNDARY DEVELOPS OUT OF MISSOURI INTO WESTERN MIDDLE TN, WE WILL SEE SHOWERS AND STORMS BECOMING INCREASINGLY LIKELY HERE INT EH MID-STATE. UNFORTUNATELY, THE STORMS OVER EASTERN MISSOURI THIS MORNING WON`T DO US ANY GOOD, SINCE THEY SHOULD CONTINUE DROPPING MORE SOUTHWARD THAT EASTWARD. HOWEVER, THAT WILL CHANGE LATER TODAY AND TOMORROW. BY THIS AFTERNOON, EXPECT BEST CAPE TO BE OVER EASTERN MISSOURI AND SOUTHERN ILLINOIS, WITH TSTMS DEVELOPING IN THE AFTERNOON HEAT AND THEN SPILLING SOUTHEASTWARD TOWARD SOUTHWESTERN KY AND NORTHWESTERN MIDDLE TENNESSEE. AT LEAST A FEW ISOLATED RW/TRW COULD WORK THEIR WAY INTO NORTHWEST AND EXTREME N-CENTRAL PARTS OF OUR CWA LATE TONIGHT, ENHANCED BY A WEAK SFC CONVERGENCE BOUNDARY THAT IS FORECAST TO BE IN OUR NORTHWEST BY 12Z WED. AS WEAK SFC CONVERGENCE BOUNDARY MOVES EASTWARD AND DISSIPATES DURING THE DAY ON WEDNESDAY, CAPES WILL BE SUFFICIENT OVER SOUTHERN KENTUCKY AND MOST OF MIDDLE TENNESSEE TO ALLOW FOR ISOLATED TO SCATTERED CONVECTION (ESPECIALLY OVER NORTHERN AND EASTERN AREAS). MEANWHILE, EXPECT A SHORTWAVE TO FIRE MORE THUNDERSTORMS TO OUR NORTHWEST, BACK OVER SOUTHEASTERN MISSOURI. SOME OF THOSE STORMS ARE EXPECTED TO AFFECT OUR NORTHWESTERN COUNTIES WEDNESDAY NIGHT. HOWEVER, THE STORMS WILL BE WEAKENING AS THEY MOVE INTO OUR CWA AND MAY NOT PENETRATE OUR SOUTHERN AND EASTERN COUNTIES BEFORE DYING OUT. BY THURSDAY, CAPES OVER OUR AREA INCREASE TO 2500+ J/KG, AND ANOTHER SHORTWAVE SHOULD BE KICKING OFF THUNDERSTORMS OVER SOUTHEASTERN MISSOURI BY LATE MORNING. THESE STORMS WILL DROP SOUTHEASTWARD AND KICK OFF OUTFLOW BOUNDARIES WHICH WILL INTERACT WITH OUR HIGH CAPE ENVIRONMENT AND RESULT IN THE DEVELOPMENT OF SCATTERED THUNDERSTORMS OVER MIDDLE TENNESSEE. OUR HIGH TEMPS ON THU WILL BE LARGELY DETERMINED BY HOW FAST THUNDERSTORMS DEVELOP OVERHEAD. WITH BOTH NAM AND GFS GIVING RELATIVELY CONSISTENT TEMPS FOR THUR, AM HESITANT TO SHAVE TOO MUCH OFF GUIDANCE NUMBERS. THUS, WILL PROBABLY ONLY LOWER FORECAST HIGH TEMPS BY 1 OR 2 DEGS. MOS POPS AREN`T MUCH HELP WITH THIS TYPE OF NORTHWEST FLOW PATTERN, AND TEND TO UNDERESTIMATE RAIN CHANCE. THEREFORE, WILL GO QUITE A BIT ABOVE MOS POP NUMBERS OVER THE NEXT SEVERAL DAYS. RATHER THAN GO WITH THE 20-30% MOS POPS FOR THU, WILL GO MORE LIKE 30-50%. LONG TERM...AS WE HEAD INTO THE WEEKEND AND EARLY NEXT WEEK, BELIEVE GFS IS NOT PROPERLY ACCOUNTING FOR THE EFFECTS OF CLOUDS AND SHOWERS. IT SEEMS TO KEEP MAX TEMPS TOO WARM. ON THE OTHER HAND, DON`T REALLY BUY THE SIGNIFICANTLY COOLER SOLUTION OF THE ECMWF. THEREFORE, WILL GO WITH A GENERALLY PERSISTENT PATTERN, WITH HIGHS TOPPING OUT NEAR CLIMO NORMS. REGARDING POPS IN THE EXTENDED, BELIEVE THE MEX NUMBERS MAY BE A BIT HIGH AND WILL TREND MORE TOWARD CLIMO BY THE LATTER PERIODS. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 21
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
117 PM MDT TUE AUG 5 2014 .SHORT TERM...(THIS AFTERNOON THROUGH WEDNESDAY NIGHT) ISSUED AT 230 PM MDT TUE AUG 5 2014 WATER VAPOR IMAGERY STILL SHOWING MONSOONAL MOISTURE OVER THE STATE OF WYOMING THIS AFTERNOON...BUT A LARGE DRY SLOT CONTINUES TO EDGE NORTHEAST FROM UTAH AND SOUTHWESTERN COLORADO. PLUME OF DEEPEST MOISTURE IS NOW OFF TO OUR EAST IN CENTRAL NEBRASKA AND SOUTH DAKOTA. AT THE SURFACE...THE FRONTAL BOUNDARY THAT MOVED INTO THE AREA LAST NIGHT AND THIS MORNING IS LAYING UP AGAINST THE LARAMIE RANGE AND IS THE FOCUS FOR SHOWERS AND THUNDERSTORM DEVELOPMENT. MOSAIC RADAR SHOWS CONVECTION CONCENTRATED EAST OF THE LARAMIE RANGE AND ACROSS THE SOUTHERN PANHANDLE SO FAR TODAY. WIDELY SCATTERED SHOWERS AND THUNDERSTORMS ACROSS SOUTHWESTERN WYOMING AND NORTHWESTERN COLORADO CONTINUE TO MOVE NORTHEAST. SOME OF THIS ACTIVITY WILL MAKE ITS WAY INTO CARBON AND ALBANY COUNTIES THIS AFTERNOON IF IT HOLDS TOGETHER. MINOR WAVE SEEN ON WATER VAPOR IMAGERY WILL TRACK FROM SOUTHWEST WYOMING THROUGH CENTRAL WYOMING AND THEN EAST IN SOUTH DAKOTA THROUGH THE AFTERNOON. THIS SHOULD AID IN INCREASING PRECIP COVERAGE. LATEST HRRR FORECAST SHOWS BANDS OF SHOWERS/TSTMS DEVELOPING OVER THE LARAMIE RANGE...THEN MOVING EAST NORTHEAST INTO THE PANHANDLE THIS AFTERNOON. COULD SEE A MARGINALLY SEVERE THUNDERSTORM EVENT ACROSS THE NORTHERN PANHANDLE TODAY WITH SBCAPES AROUND 1200-1400 J/KG AROUND ALLIANCE AND CHADRON. THEY ARE STILL CAPPED PRETTY GOOD THOUGH SO FAR. NAM SOUNDINGS SHOWING THIS CAP BREAKING AROUND 21Z OR SO AND HRRR SHOWING A PRETTY STRONG CELL DEVELOPING SOUTH OF MONTROSE IN SIOUX COUNTY OUT IN THE NORTHERN PANHANDLE BY LATE AFTERNOON. WITH THE SHORTWAVE MOVING THROUGH THE AREA THIS EVENING...THE FRONTAL SYSTEM BEGINS TO BE LIFTED NORTHEAST. SHOWERS AND THUNDERSTORMS SHOULD DECREASE IN COVERAGE ACROSS EXTREME SOUTHEAST WYOMING AND THE SOUTHERN PANHANDLE THIS EVENING. SHOWERS AND THUNDERSTORMS RETURN WEDNESDAY AFTERNOON WITH THE ECMWF AND NAM/WRF MODELS IN GOOD AGREEMENT. BEST AREA FOR CONVECTION LOOKS TO BE EAST OF THE LARAMIE RANGE AND THE PANHANDLE BY MID AFTERNOON PERSISTING INTO MID EVENING BEFORE TAPERING OFF WITH LOSS OF DAYTIME HEATING. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 1159 AM MDT TUE AUG 5 2014 THURSDAY...EVEN THOUGH RIDGING ALOFT WILL LIMIT AREAL THUNDERSTORM COVERAGE...LOOKS LIKE ENOUGH LOW AND MID LEVEL MOISTURE FOR LATE DAY ISOLATED TO SCATTERED THUNDERSTORMS...MOST NUMEROUS FROM SIDNEY TO CHADRON WHERE UPWARD VERTICAL MOTION WILL BE MOST PRONOUNCED. FRIDAY...INCREASE IN LOW AND MID LEVEL MOISTURE ALONG WITH A WELL PRONOUNCED LOW AND MID LEVEL THETA-E RIDGE AXIS WILL AID IN AT LEAST SCATTERED AFTERNOON THUNDERSTORMS EAST OF INTERSTATE 25. SATURDAY...AS THE ATMOSPHERE DRIES SOMEWHAT FROM FRIDAY...WE EXPECT A CORRESPONDING DECREASE INT THE AREAL THUNDERSTORM COVERAGE. BEST CHANCES FOR STORMS WILL BE ALONG WESTERN NEBRASKA WHERE A LOW LEVEL CONVERGENCE AXIS IS PROGGED TO DEVELOP. SUNDAY/TUESDAY...ISOLATED LATE DAY THUNDERSTORMS WILL OCCUR WITH ADEQUATE LOW AND MID LEVEL MOISTURE AND WEAK LOW LEVEL UPSLOPE EAST WINDS. MONDAY...MINIMAL THUNDERSTORM CHANCES WITH RIDGING ALOFT AND LIMITED LOW AND MID LEVEL MOISTURE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY MORNING) ISSUED AT 1047 AM MDT TUE AUG 5 2014 USED LATEST HRRR MODEL RUN TO DETERMINE PRECIP LOCATION AND TIMING FOR OUR SOUTHEAST WYOMING AND NEBRASKA PANHANDLE TAFS THIS AFTERNOON. THIS MODEL HAS BEEN DOING VERY WELL ON CONVECTIVE INITIATION AND TIMING. IFR STRATUS TO RETURN LATE TONIGHT FOR THE NORTHERN PANHANDLE AS WELL. && .FIRE WEATHER... ISSUED AT 230 PM MDT TUE AUG 5 2014 MONSOONAL MOISTURE FROM THE SOUTHWEST WILL CONTINUE TO BRING THE AREA CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH THE WEEK. AFTERNOON HUMIDITIES EXPECTED TO REMAIN ABOVE CRITICAL THRESHOLDS THROUGH SATURDAY...MAINLY FALLING TO THE LOW TO MID 20 PERCENT RANGE. EXPECT FAIR OVERNIGHT RECOVERIES IN HUMIDITY WEST OF THE LARAMIE RANGE WITH EXCELLENT RECOVERIES EAST. DECREASING COVERAGE OF SHOWERS AND THUNDERSTORMS FROM TODAY ON FOR THE MOST PART AS MONSOONAL MOISTURE GETS SHUNTED SOUTH AND EAST. WINDS TO REMAIN LIGHT THROUGH THE WEEK AS WELL...KEEPING ELEVATED FIRE WEATHER CONDITIONS IN CHECK. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ SHORT TERM...CLAYCOMB LONG TERM...RUBIN AVIATION...CLAYCOMB FIRE WEATHER...CLAYCOMB
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1054 AM MDT TUE AUG 5 2014 .UPDATE... ISSUED AT 1047 AM MDT TUE AUG 5 2014 WITH DENSE CLOUD CANOPY AND UPSLOPING CONDITIONS...TEMPERATURES HAVE BEEN SLOW TO WARM LATE THIS MORNING. WENT AHEAD AND LOWERED MAX TEMPERATURES 3-4 DEGREES FOR MOST AREAS EAST OF THE LARAMIE RANGE FOR THIS AFTERNOON. PROBABLY STILL TOO HIGH. WOULD NOT BE SURPRISED IF CHEYENNE DOES NOT GET OUT OF THE 60S TODAY. UPDATES HAVE BEEN SENT. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 345 AM MDT TUE AUG 5 2014 PREDAWN WATER VAPOR IMAGERY REVEALED A UPPER RIDGE CENTERED OVER THE HIGH PLAINS AND UPPER TROUGH FROM THE NORTHERN ROCKIES THROUGH CA. A SHORTWAVE TROUGH WAS LIFTING NORTHWARD ACROSS THE FOUR CORNERS ENHANCING TSTORM ACTIVITY OVER EASTERN UT/WESTERN CO. EXPANSIVE PLUME OF SUBTROPICAL/MONSOON MOISTURE WAS ADVECTED NORTHEAST FROM THE GREAT BASIN THROUGH THE CENTRAL/SOUTHERN ROCKIES AND HIGH PLAINS. THE REGIONAL SURFACE ANALYSIS DEPICTED A STATIONARY FRONT FROM EASTERN MT TO ALONG THE LARAMIE RANGE AND INTO NORTHERN KS. SHOWERS/ISOLATED TSTORMS OBSERVED EARLIER OVER EAST CENTRAL WY MOVED INTO NORTHEAST WY/WESTERN SD. SKIES WERE MOSTLY CLOUDY WITH TEMPERATURES IN THE MID 50S TO MID 60S. WINDS WERE VARIABLE 5-10 MPH. THE LATEST SHORT RANGE MODEL CONSENSUS CONTINUES THE UNSETTLED WEATHER PATTERN AS THE UPPER RIDGE AXIS REMAINS ANCHORED OVER OR JUST EAST OF THE FRONT RANGE WITH A UPPER TROUGH ACROSS THE INTERMOUNTAIN WEST. SHORTWAVE TO THE SOUTHWEST RIDES NORTHEAST ACROSS CO AND WY THIS AFTERNOON. ACTIVE SUBTROPICAL MOISTURE PLUME INTERACTING WITH THE WAVE AND INSTABILITY WILL ENHANCE SHOWER/TSTORM DEVELOPMENT WITH THE POTENTIAL FOR LOCALLY HEAVY RAIN. WHILE THE SEVERE THREAT REMAINS LOW... SMALL HAIL AND GUSTY WINDS WILL ACCOMPANY THE STRONGER TSTORMS. SHOWER COVERAGE DECREASES FROM SOUTH TO NORTH TONIGHT AS SOME DRIER AIR ALOFT EDGES INTO THE REGION FROM CO. ISOLATED SHOWERS/TSTORMS WILL CONTINUE NORTH OF A RAWLINS TO ALLIANCE LINE WEDNESDAY MORNING. ANOTHER SHORTWAVE BREAKS DOWN THE RIDGE AS IT MOVES EAST ACROSS WY WEDNESDAY AFTERNOON. MOISTURE PLUME WILL EXTEND FROM NORTHWEST TO SOUTHEAST WITH SCATTERED SHOWERS/TSTORMS DEVELOPING AREAWIDE. CONVECTION ENDS BY MIDNIGHT WEDNESDAY NIGHT WITH SOMEWHAT DRIER AIR ALOFT SPREADING NORTHEAST INTO THE CWA. ON THURSDAY...SOME MORNING SHOWERS WILL DEVELOP EAST OF A DOUGLAS TO SIDNEY LINE AS YET ANOTHER SHORTWAVE RIDES SOUTHEAST ON LEE SIDE OF THE UPPER RIDGE. A RESURGENCE OF MONSOON MOISTURE INTERACTING WITH ANOTHER PASSING WAVE WILL INCREASE SHOWER/TSTORM COVERAGE OVER THE PLAINS DURING THE AFTERNOON. TEMPERATURES DURING THE SHORT TERM WILL AVERAGE NEAR SEASONAL NORMALS WITH HIGHS IN THE 80S LOWER ELEVATIONS AND 60S/70S FOR THE HIGH COUNTRY. LOWS WILL RANGE FROM THE 50S TO LOWER 60S WITH 40S FOR THE MOUNTAINS AND HIGH VALLEYS. .LONG TERM...(THURSDAY NIGHT THROUGH MONDAY) ISSUED AT 312 AM MDT TUE AUG 5 2014 CONFIDENCE IS LOW IN THE EXTENDED FCST PERIOD WITH A MUDDLED UPPER LEVEL PATTERN IN PLACE. MEDIUM RANGE MODEL GUIDANCE STILL STRUGGLES WITH THE TIMING AND PLACEMENT OF SIGNIFICANT SYSTEMS...WHICH COULD HAVE AN IMPACT ON PCPN CHANCES ACROSS THE CWA. GENERALLY THE CENTRAL ROCKIES WILL REMAIN ON THE NORTH SIDE OF BROAD/FLAT RIDGING FROM THE SOUTHERN PLAINS INTO THE FOUR CORNERS. PCPN CHANCES WILL BE GOVERNED BY INDIVIDUAL DISTURBANCES TRAVERSING THE FLOW. LITTLE CHANGE IN THE ECMWF WITH A SHORTWAVE MEANDERING SLOWLY ACROSS CENTRAL WY THROUGH EARLY SAT. THE GFS IS THE MORE PROGRESSIVE MODEL WHICH WOULD SUPPORT A QUICK SHOT OF SHOWERS AND TSTMS AS OPPOSED TO A MORE WIDESPREAD AND LONGER DURATION EVENT. 700-300 MILLIBAR RH PROGS FROM BOTH GFS AND ECMWF SHOW POCKETS OF MONSOONAL MOISTURE MOVING ACROSS THE CWA THROUGH MOST OF THE PERIOD. THIS IS ENOUGH TO SUPPORT ISOLATED POPS EVEN AT NIGHT AS ENOUGH FORCING SHOULD EXIST WITH MORE PRONOUNCED WAVES AND OCCASIONAL LOW LEVEL UPSLOPE ALONG THE LARAMIE RANGE. FRIDAY SHOULD FEATURE THE BEST CHANCE FOR PCPN WITH GOOD DYNAMIC FORCING OVER OUR EASTERN ZONES. DID NOT FEEL COMFORTABLE GOING HIGHER THAN 40 PERCENT POPS IN MOST CASES GIVEN THE VAST MODEL DIFFERENCES IN QPF. AS FAR AS TEMPERATURES ARE CONCERNED...SEASONAL. WARMING AND DRYING TREND MON AND TUE AS THE UPPER RIDGE BUILDS BACK INTO THE AREA. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY MORNING) ISSUED AT 1047 AM MDT TUE AUG 5 2014 USED LATEST HRRR MODEL RUN TO DETERMINE PRECIP LOCATION AND TIMING FOR OUR SOUTHEAST WYOMING AND NEBRASKA PANHANDLE TAFS THIS AFTERNOON. THIS MODEL HAS BEEN DOING VERY WELL ON CONVECTIVE INITIATION AND TIMING. IFR STRATUS TO RETURN LATE TONIGHT FOR THE NORTHERN PANHANDLE AS WELL. && .FIRE WEATHER... ISSUED AT 253 AM MDT TUE AUG 5 2014 A PREVAILING SOUTHWEST FLOW ALOFT BETWEEN A RIDGE ACROSS THE HIGH PLAINS AND TROUGH OVER THE INTERMOUNTAIN WEST WILL CONTINUE TO ADVECT SUBTROPICAL MOISTURE ACROSS THE DISTRICTS THROUGH THE END OF THE WEEK. WEAK UPPER LEVEL DISTURBANCES AND A SURFACE BOUNDARY EAST OF THE FRONT RANGE WILL ENHANCE LIFT FOR SHOWERS AND THUNDERSTORMS...MOST NUMEROUS THIS AFTERNOON AND EARLY EVENING. WETTING RAINFALL AND HIGH RELATIVE HUMIDITY WILL PRECLUDE FIRE WEATHER CONCERNS. WINDS WILL AVERAGE AROUND 10 MPH...EXCEPT VARIABLE AND GUSTY IN AND NEAR THUNDERSTORMS. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ UPDATE...CLAYCOMB SHORT TERM...JAMSKI LONG TERM...HAMMER AVIATION...CLAYCOMB FIRE WEATHER...JAMSKI