Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 06/21/15


AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
939 PM MDT SAT JUN 20 2015 .UPDATE... ISSUED AT 934 PM MDT SAT JUN 20 2015 MAINLY DRY WESTERLY FLOW ALOFT OVER COLORADO. APPEARS STORMS OVER NEBRASKA WILL STAY NORTH AND EAST OF COLORADO SO WILL REMOVE SLIGHT CHANCE OF STORMS FROM THE FAR NE PLAINS. NO OTHER CHANGES TO CURRENT FORECAST. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 303 PM MDT SAT JUN 20 2015 EXCEPT FOR SOME CLOUDS OVR THE HYR TRRN THIS AFTERNOON...SKIES HAVE BEEN MOSTLY SUNNY...WITH TEMPS AROUND TO SLIGHTLY ABOVE AVERAGE. A DISTURBANCE MOVING ACRS WY TODAY AND THIS EVENING IS EXPECTED TO BRING A CHANCE FOR SOME THUNDERSTORMS TO THE NORTHEAST CORNER OF THE STATE. THE HRRR SHOWS THE POTENTIAL FOR THUNDERSTORMS MOVING INTO THE NE CORNER BY 00Z...THEN MOVING SOUTHEASTWARD OUT OF THE AREA BY ABOUT 03Z. THE NAM AND HRRR KEEP THE REST OF THE FORECAST AREA DRY THIS EVENING AND OVERNIGHT. THE GFS STILL SHOWS THE POTENTIAL FOR SOME CONVECTION ALONG THE MTNS THIS EVENING...AND KEEPS SOME PCPN GOING OVR THE FAR NE CORNER OF THE STATE A BIT LATER THAN OTHER MODELS. WL LEAN MORE TOWARD THE GFS TO ALSO MATCH WITH SURROUNDING FORECAST AREAS...AND KEEP THE CONVECTION GOING UNTIL AROUND MIDNIGHT. WITH A WARM UPR RIDGE SITTING OVR THE AREA ON SUN...CHANCES FOR PCPN LOOK QUITE LIMITED AND WL KEEP THE FORECAST DRY. HIGHS ON SUN WL BE QUITE WARM...WITH 90S OVER THE NERN PLAINS WHICH IS ABOUT 10 DEGREES ABOVE AVERAGE. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 303 PM MDT SAT JUN 20 2015 DRY WX WL CONTINUE SUN NIGHT AND MON AS THE UPR RIDGE CONTINUES TO BE THE MAIN FEATURE OVR THE AREA. A FRONTAL BOUNDARY IS FORECAST TO MOVE THRU THE ERN AREAS MON MORNING...BRINGING NORTHERLY WINDS...PROBABLY GUSTY OVR THE FAR ERN AREAS. THE SFC WINDS THEN BECOME EASTERLY IN THE AFTERNOON. THE FRONT WL HAVE LITTLE EFFECT OF THE WX AS TEMPS ARE STILL EXPECTED TO WARM INTO THE 90S OVR ERN AREAS IN THE AFTERNOON. BY MON NIGHT...THE UPR RIDGE BECOMES BROAD...STRETCHING FROM NM TO THE SERN STATES. MON NIGHT...WITH SFC HIGH PRESSURE BUILDING INTO NORTHEAST CO...LOW LEVEL MSTR IS EXPECTED TO INCREASE WITH LOW STRATUS DEVELOPING. THE MODELS ARE SLOW TO CLEAR THE LOW CLOUDS OUT OF THE FAR NERN PLAINS ON TUE. TEMPS ACRS NERN CO ARE EXPECTED TO BE A LITTLE COOLER TUE THAN THEY WL BE ON MON. THE HYR ELEVATIONS WL ALSO SEE JUST A SLIGHT COOL DOWN. TUE THERE COULD ALSO BE SOME LIGHT PCPN OVR THE FAR NERN AREAS...AND THEN IN THE AFTERNOON SHOWERS AND TSTMS WL BE POSSIBLE...ESPECIALLY OVR AND NR THE MTNS AND ALONG THE I-25 CORRIDOR. TUE NIGHT AND WED THE UPR RIDGE WL BE FLATTENED OVR THE AREA AS A DISTURBANCE MOVES THRU WY AND INTO THE NRN AND CENTRAL PLAINS STATES. IT LOOKS LIKE LOW STRATUS WL RETURN TO THE PLAINS TUE NIGHT/WED MORNING...THEN DISSIPATING BY NOON. THE FORECAST MODELS ARE SHOWING AN INCREASE IN SUB TROPICAL MSTR OVR THE AREA FOR WED AND THU...LEADING TO A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS. AN UPR RIDGE IS THEN EXPECTED TO BE OVR THE GREAT BASIN BY FRI...BUT A DISTURBANCE MOVING OVR MAINLY ERN PORTION OF THE AREA...IN THE NW FLOW ON THE FRONT SIDE OF THE RIDGE...IS FORECAST TO BRING PCPN TO THE FRONT RANGE AND THE PLAINS. SAT THE UPR RIDGE REMAINS OVR THE GREAT BASIN AND MOIST EASTERLY FLOW OVR ERN CO IS EXPECTED TO LEAD TO PCPN OVR MUCH OF THE FORECAST AREA. && .AVIATION...(FOR THE TAFS THROUGH 06Z SUNDAY EVENING) ISSUED AT 934 PM MDT SAT JUN 20 2015 VFR WITH MAINLY CLEAR SKIES TONIGHT. SURFACE WINDS SHIFTING SOUTHEAST AND IN PROCESS OF MOVING TO DRAINAGE WINDS FROM THE SOUTH AND SOUTHWEST BY MIDNIGHT. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...ENTREKIN SHORT TERM...WFO PUB 28 LONG TERM...WFO PUB 28 AVIATION...ENTREKIN
AREA FORECAST DISCUSSION
NWS PUEBLO CO
853 PM MDT SAT JUN 20 2015 .UPDATE... ISSUED AT 842 PM MDT SAT JUN 20 2015 UPDATED TO END SHOWERS AND THUNDERSTORMS ACROSS THE AREA FOR THE REMAINDER OF THE NIGHT. RADAR AND SATELLITE INDICATE A COUPLE OF SHOWERS STILL OVER THE SAN JUAN RANGE...BUT HAVE QUICKLY BEEN DISSIPATING AND SHOULD COME TO AN END BY 10 PM. NO OTHER UPDATES AT THIS TIME. MOZLEY && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 256 PM MDT SAT JUN 20 2015 WEAK COLD FRONT WHICH PUSHED THROUGH THE PLAINS EARLIER TODAY HAS BROUGHT E-NE WINDS AND SLIGHTLY COOLER TEMPS TO THE PLAINS/ERN MOUNTAINS...WHILE TEMPS FARTHER WEST OVER THE MOUNTAINS AND INTERIOR VALLEYS REMAIN LITTLE CHANGED. LOW LEVEL MOISTURE/INSTABILITY LOOK SUFFICIENT FOR SOME ISOLATED TSRA OVER THE ERN MOUNTAINS...THOUGH LACK OF ANY TRIGGER AND FAIRLY SUBSTANTIAL CIN HAS SO FAR KEPT THINGS IN CHECK. LAST COUPLE RUNS OF THE NAM STILL HAVE SOME WEAK TSRA DEVELOPING...WHILE HRRR AND OTHER MESOSCALE MODELS ARE MAINLY DRY. WILL KEEP JUST SOME VERY LOW POPS FOR A FEW OF THE HIGHER PEAKS INTO EARLY EVENING...THOUGH WOULD NOT BE TOO SURPRISED TO SEE AREA REMAIN CONVECTION FREE AT THIS POINT. ANY CLOUDS WILL CLEAR QUICKLY AFTER SUNSET...WITH OVERNIGHT LOWS JUST SLIGHTLY COOLER THAN SAT MORNING MOST LOCATIONS. ON SUNDAY...HEIGHTS BUILD SLIGHTLY AND WITH PRESSURE FALLS OVER THE PLAINS PRODUCING A RETURN TO S-SW WINDS...EXPECT ALL AREAS TO BECOME VERY HOT ONCE AGAIN...WITH READINGS NEAR/OVER 100F ACROSS THE LOWER ARK VALLEY. AIR MASS LOOKS TOO DRY TO SUPPORT ANY CONVECTION...SO WILL KEEP A DRY FORECAST GOING ALL AREAS THROUGH THE AFTERNOON. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 256 PM MDT SAT JUN 20 2015 SUNDAY NIGHT AND MONDAY...STRONG UPPER RIDGE WILL BRING MAINLY DRY AND HOT WEATHER ACROSS THE CWA. THERE WILL ONLY BE A VERY SLIGHT CHANCE FOR LATE AFTERNOON AND EVENING HIGH BASED CONVECTION OVER THE EASTERN PART OF THE AREA. HIGH TEMPERATURES WILL RANGE FROM 90 TO 100 ACROSS THE I-25 CORRIDOR AND SOUTHEAST PLAINS...70S AND 80S HIGH VALLEYS...AND 60S AND 70S MOUNTAINS. TUESDAY AND WEDNESDAY...UPPER RIDGE PUSHES EAST SOME...ALLOWING A FETCH OF MODEST MOISTURE TO ENTER THE AREA. IN ADDITION...A SURFACE BOUNDARY WILL BE IN THE VICINITY OF THE EASTERN PLAINS...SO ISOLATED TO SCATTERED PRECIPITATION WILL BE EVIDENT DURING THE AFTERNOON AND EVENING HOURS. MODELS DIVERGENT ON HOW MUCH CONVECTION WILL BE ACROSS THE EAST TUESDAY EVENING. GFS HAS THE MOST...WITH EUROPEAN BARELY ANY. THERE IS THE POTENTIAL FOR A FEW SEVERE STORMS BOTH DAYS WITH INSTABILITY VALUES INCREASING. WITH SOME CLOUD COVER...TEMPERATURES WILL BE A LITTLE LOWER THAN OVER THE WEEKEND. THURSDAY THROUGH SUNDAY...UPPER RIDGE FORECAST TO BUILD TO OUR WEST DURING THE PERIOD. GFS SHOWS A SHORTWAVE RIDING DOWN THE NORTHEAST SIDE OF THE RIDGE IN THE THURSDAY TO FRIDAY TIME FRAME...MORE SO THAN THE EUROPEAN. THERE WILL LIKELY BE DIURNAL SHOWERS AND STORMS EACH DAY WITH NORTHWEST FLOW ALOFT ON THE FRONT SIDE OF THE RIDGE....MORE CONCENTRATED ACROSS THE EASTERN HALF OF THE CWA. HIGH TEMPERATURES WILL BE NEAR SEASONAL AVERAGES...IN THE 80S AND 90S PLAINS...70S AND 80S HIGH VALLEYS AND 50S TO 70S MOUNTAINS. -TLM- && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY) ISSUED AT 256 PM MDT SAT JUN 20 2015 VFR CONDITIONS ARE EXPECTED THE NEXT 24 HOURS AT ALL TAF SITES. ISOLATED THUNDERSTORMS WILL BE POSSIBLE ACROSS THE MOUNTAINS THIS AFTERNOON/EARLY EVENING...ESPECIALLY WEST OF KCOS...BUT COVERAGE WILL BE TOO LIMITED TO INCLUDE IN ANY TAF. EVEN LESS CHANCE OF CONVECTION ON SUN. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...MOZLEY SHORT TERM...PETERSEN LONG TERM...TM AVIATION...PETERSEN
AREA FORECAST DISCUSSION...RESENT
NWS DENVER/BOULDER CO
ISSUED BY NATIONAL WEATHER SERVICE PUEBLO CO 303 PM MDT SAT JUN 20 2015 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 303 PM MDT SAT JUN 20 2015 EXCEPT FOR SOME CLOUDS OVR THE HYR TRRN THIS AFTERNOON...SKIES HAVE BEEN MOSTLY SUNNY...WITH TEMPS AROUND TO SLIGHTLY ABOVE AVERAGE. A DISTURBANCE MOVING ACRS WY TODAY AND THIS EVENING IS EXPECTED TO BRING A CHANCE FOR SOME THUNDERSTORMS TO THE NORTHEAST CORNER OF THE STATE. THE HRRR SHOWS THE POTENTIAL FOR THUNDERSTORMS MOVING INTO THE NE CORNER BY 00Z...THEN MOVING SOUTHEASTWARD OUT OF THE AREA BY ABOUT 03Z. THE NAM AND HRRR KEEP THE REST OF THE FORECAST AREA DRY THIS EVENING AND OVERNIGHT. THE GFS STILL SHOWS THE POTENTIAL FOR SOME CONVECTION ALONG THE MTNS THIS EVENING...AND KEEPS SOME PCPN GOING OVR THE FAR NE CORNER OF THE STATE A BIT LATER THAN OTHER MODELS. WL LEAN MORE TOWARD THE GFS TO ALSO MATCH WITH SURROUNDING FORECAST AREAS...AND KEEP THE CONVECTION GOING UNTIL AROUND MIDNIGHT. WITH A WARM UPR RIDGE SITTING OVR THE AREA ON SUN...CHANCES FOR PCPN LOOK QUITE LIMITED AND WL KEEP THE FORECAST DRY. HIGHS ON SUN WL BE QUITE WARM...WITH 90S OVER THE NERN PLAINS WHICH IS ABOUT 10 DEGREES ABOVE AVERAGE. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 303 PM MDT SAT JUN 20 2015 DRY WX WL CONTINUE SUN NIGHT AND MON AS THE UPR RIDGE CONTINUES TO BE THE MAIN FEATURE OVR THE AREA. A FRONTAL BOUNDARY IS FORECAST TO MOVE THRU THE ERN AREAS MON MORNING...BRINGING NORTHERLY WINDS...PROBABLY GUSTY OVR THE FAR ERN AREAS. THE SFC WINDS THEN BECOME EASTERLY IN THE AFTERNOON. THE FRONT WL HAVE LITTLE EFFECT OF THE WX AS TEMPS ARE STILL EXPECTED TO WARM INTO THE 90S OVR ERN AREAS IN THE AFTERNOON. BY MON NIGHT...THE UPR RIDGE BECOMES BROAD...STRETCHING FROM NM TO THE SERN STATES. MON NIGHT...WITH SFC HIGH PRESSURE BUILDING INTO NORTHEAST CO...LOW LEVEL MSTR IS EXPECTED TO INCREASE WITH LOW STRATUS DEVELOPING. THE MODELS ARE SLOW TO CLEAR THE LOW CLOUDS OUT OF THE FAR NERN PLAINS ON TUE. TEMPS ACRS NERN CO ARE EXPECTED TO BE A LITTLE COOLER TUE THAN THEY WL BE ON MON. THE HYR ELEVATIONS WL ALSO SEE JUST A SLIGHT COOL DOWN. TUE THERE COULD ALSO BE SOME LIGHT PCPN OVR THE FAR NERN AREAS...AND THEN IN THE AFTERNOON SHOWERS AND TSTMS WL BE POSSIBLE...ESPECIALLY OVR AND NR THE MTNS AND ALONG THE I-25 CORRIDOR. TUE NIGHT AND WED THE UPR RIDGE WL BE FLATTENED OVR THE AREA AS A DISTURBANCE MOVES THRU WY AND INTO THE NRN AND CENTRAL PLAINS STATES. IT LOOKS LIKE LOW STRATUS WL RETURN TO THE PLAINS TUE NIGHT/WED MORNING...THEN DISSIPATING BY NOON. THE FORECAST MODELS ARE SHOWING AN INCREASE IN SUB TROPICAL MSTR OVR THE AREA FOR WED AND THU...LEADING TO A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS. AN UPR RIDGE IS THEN EXPECTED TO BE OVR THE GREAT BASIN BY FRI...BUT A DISTURBANCE MOVING OVR MAINLY ERN PORTION OF THE AREA...IN THE NW FLOW ON THE FRONT SIDE OF THE RIDGE...IS FORECAST TO BRING PCPN TO THE FRONT RANGE AND THE PLAINS. SAT THE UPR RIDGE REMAINS OVR THE GREAT BASIN AND MOIST EASTERLY FLOW OVR ERN CO IS EXPECTED TO LEAD TO PCPN OVR MUCH OF THE FORECAST AREA. && .AVIATION...(FOR THE TAFS THROUGH 00Z SUNDAY LATE AFTERNOON) ISSUED AT 303 PM MDT SAT JUN 20 2015 VFR ALL TAF SITES. HRRR CONTINUES TO SHOW CONVECTION BETWEEN 23Z AND 02Z OVER EXTREME NORTHEAST COLORADO (NORTHEAST WELD...LOGAN... SEDGEWICK AND PHILLIPS COUNTIES). NAM AND GFS KEEP ANY CONVECTION DURING THE EVENING FURTHER TO THE NORTH AND EAST. WILL NOT MENTION TS IN THE TAF SITES OVERNIGHT SINCE EXPECT CONVECTION TO STAY WELL NORTHEAST OF THE DENVER METRO AREA. ON SUNDAY...DRIER AIR ALOFT WILL CONTINUE TO ADVECT INTO THE REGION FROM THE WEST...AND LOWER LEVEL MOISTURE WILL MIX OUT BY THE AFTERNOON. WITH DRIER AIR MASS OVER THE REGION...CHANCES FOR AFTERNOON CONVECTION ARE VERY SMALL AND LEFT ANY MENTION OF TS OUT OF TAFS. --PGW...WFO PUB && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...WFO PUB 28 LONG TERM...WFO PUB 28 AVIATION...WFO PUB PGW
AREA FORECAST DISCUSSION
NWS PUEBLO CO
257 PM MDT SAT JUN 20 2015 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 256 PM MDT SAT JUN 20 2015 WEAK COLD FRONT WHICH PUSHED THROUGH THE PLAINS EARLIER TODAY HAS BROUGHT E-NE WINDS AND SLIGHTLY COOLER TEMPS TO THE PLAINS/ERN MOUNTAINS...WHILE TEMPS FARTHER WEST OVER THE MOUNTAINS AND INTERIOR VALLEYS REMAIN LITTLE CHANGED. LOW LEVEL MOISTURE/INSTABILITY LOOK SUFFICIENT FOR SOME ISOLATED TSRA OVER THE ERN MOUNTAINS...THOUGH LACK OF ANY TRIGGER AND FAIRLY SUBSTANTIAL CIN HAS SO FAR KEPT THINGS IN CHECK. LAST COUPLE RUNS OF THE NAM STILL HAVE SOME WEAK TSRA DEVELOPING...WHILE HRRR AND OTHER MESOSCALE MODELS ARE MAINLY DRY. WILL KEEP JUST SOME VERY LOW POPS FOR A FEW OF THE HIGHER PEAKS INTO EARLY EVENING...THOUGH WOULD NOT BE TOO SURPRISED TO SEE AREA REMAIN CONVECTION FREE AT THIS POINT. ANY CLOUDS WILL CLEAR QUICKLY AFTER SUNSET...WITH OVERNIGHT LOWS JUST SLIGHTLY COOLER THAN SAT MORNING MOST LOCATIONS. ON SUNDAY...HEIGHTS BUILD SLIGHTLY AND WITH PRESSURE FALLS OVER THE PLAINS PRODUCING A RETURN TO S-SW WINDS...EXPECT ALL AREAS TO BECOME VERY HOT ONCE AGAIN...WITH READINGS NEAR/OVER 100F ACROSS THE LOWER ARK VALLEY. AIR MASS LOOKS TOO DRY TO SUPPORT ANY CONVECTION...SO WILL KEEP A DRY FORECAST GOING ALL AREAS THROUGH THE AFTERNOON. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 256 PM MDT SAT JUN 20 2015 SUNDAY NIGHT AND MONDAY...STRONG UPPER RIDGE WILL BRING MAINLY DRY AND HOT WEATHER ACROSS THE CWA. THERE WILL ONLY BE A VERY SLIGHT CHANCE FOR LATE AFTERNOON AND EVENING HIGH BASED CONVECTION OVER THE EASTERN PART OF THE AREA. HIGH TEMPERATURES WILL RANGE FROM 90 TO 100 ACROSS THE I-25 CORRIDOR AND SOUTHEAST PLAINS...70S AND 80S HIGH VALLEYS...AND 60S AND 70S MOUNTAINS. TUESDAY AND WEDNESDAY...UPPER RIDGE PUSHES EAST SOME...ALLOWING A FETCH OF MODEST MOISTURE TO ENTER THE AREA. IN ADDITION...A SURFACE BOUNDARY WILL BE IN THE VICINITY OF THE EASTERN PLAINS...SO ISOLATED TO SCATTERED PRECIPITATION WILL BE EVIDENT DURING THE AFTERNOON AND EVENING HOURS. MODELS DIVERGENT ON HOW MUCH CONVECTION WILL BE ACROSS THE EAST TUESDAY EVENING. GFS HAS THE MOST...WITH EUROPEAN BARELY ANY. THERE IS THE POTENTIAL FOR A FEW SEVERE STORMS BOTH DAYS WITH INSTABILITY VALUES INCREASING. WITH SOME CLOUD COVER...TEMPERATURES WILL BE A LITTLE LOWER THAN OVER THE WEEKEND. THURSDAY THROUGH SUNDAY...UPPER RIDGE FORECAST TO BUILD TO OUR WEST DURING THE PERIOD. GFS SHOWS A SHORTWAVE RIDING DOWN THE NORTHEAST SIDE OF THE RIDGE IN THE THURSDAY TO FRIDAY TIME FRAME...MORE SO THAN THE EUROPEAN. THERE WILL LIKELY BE DIURNAL SHOWERS AND STORMS EACH DAY WITH NORTHWEST FLOW ALOFT ON THE FRONT SIDE OF THE RIDGE....MORE CONCENTRATED ACROSS THE EASTERN HALF OF THE CWA. HIGH TEMPERATURES WILL BE NEAR SEASONAL AVERAGES...IN THE 80S AND 90S PLAINS...70S AND 80S HIGH VALLEYS AND 50S TO 70S MOUNTAINS. -TLM- && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY) ISSUED AT 256 PM MDT SAT JUN 20 2015 VFR CONDITIONS ARE EXPECTED THE NEXT 24 HOURS AT ALL TAF SITES. ISOLATED THUNDERSTORMS WILL BE POSSIBLE ACROSS THE MOUNTAINS THIS AFTERNOON/EARLY EVENING...ESPECIALLY WEST OF KCOS...BUT COVERAGE WILL BE TOO LIMITED TO INCLUDE IN ANY TAF. EVEN LESS CHANCE OF CONVECTION ON SUN. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...PETERSEN LONG TERM...TM AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
631 PM MDT FRI JUN 19 2015 .UPDATE... ISSUED AT 630 PM MDT FRI JUN 19 2015 A FEW SHOWERS FORMING OVER EASTERN LARIMER AND WESTERN WELD COUNTIES. THESE SHOULDN`T LAST LONG BUT HAVE UPDATED FORECAST TO INCLUDE THEM. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 213 PM MDT FRI JUN 19 2015 AN UPPER LEVEL RIDGE WILL REMAIN OVER THE DESERT SOUTHWEST WITH A DRY WESTERLY FLOW ALOFT OVER COLORADO. OVERALL THE AIRMASS IS CAPPED...BUT HRRR RUNS STILL DEVELOPS SOME THUNDERSTORMS LATE THIS AFTN/EVNG. MOST LIKELY LOCATION WOULD APPEAR BE THE FAR NORTHEAST PLAINS WHERE THE BEST LOW LEVEL MOISTURE AND VERTICAL SHEAR WILL BE. COVERAGE WILL BE ISOLATED BUT THE ONE OR TWO STORMS THAT DO FORM COULD PRODUCE HAIL TO ONE INCH. A COOL FRONT IS PROGGED TO PUSH SOUTHWARD INTO THE NORTHEAST PLAINS LATE TONIGHT AND SATURDAY MORNING. AS A RESULT...TEMPERATURES WILL NOT BE AS HOT BUT STILL ABOVE NORMAL FOR THIS TIME OF YEAR. COULD SEE SOME SCATTERED STRATUS CLOUDS WITH THE FRONT IN THE MORNING NORTH AND EAST OF DENVER. THE FRONT WILL BECOME STATIONARY ALONG THE FOOTHILLS/PALMER DIVIDE. MAYBE ENOUGH MOISTURE/CONVERGENCE TO TRIGGER ISOLATED THUNDERSTORM COVERAGE FM THE FRONT RANGE FOOTHILLS EASTWARD BY LATE IN THE AFTN. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 213 PM MDT FRI JUN 19 2015 A FLAT UPPER LEVEL RIDGE OF HIGH PRESSURE WILL DOMINATE THE SOUTHERN AND CENTRAL ROCKIES SATURDAY NIGHT THROUGH TUESDAY...WITH A DRY WESTERLY FLOW ALOFT OVER COLORADO. THIS PATTERN WILL BRING HOT AND DRY WEATHER TO NORTH CENTRAL AND NORTHEASTERN COLORADO. THE ONLY EXCEPTION MAY BE A FEW THUNDERSTORMS ACROSS THE PLAINS SATURDAY NIGHT ASSOCIATED WITH AN UPPER LEVEL DISTURBANCE. ONE OR TWO OF THE STORMS COULD BE STRONG TO SEVERE IF THE CAP CAN BE BROKEN. ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS MAY RETURN TO THE REGION TUESDAY NIGHT THROUGH WEDNESDAY NIGHT AS THE UPPER RIDGE SHIFTS INTO THE SOUTHWESTERN U.S AND SUBTROPICAL MOISTURE BEGINS TO FLOW INTO COLORADO FROM THE SOUTH. MODELS SHOW THE UPPER RIDGE REBUILDING OVER THE SOUTHWESTERN STATES ON THURSDAY...WITH A DRY NORTHWEST FLOW ALOFT SETTING UP OVER COLORADO. THIS PATTERN WOULD ALLOW OCCASIONAL COOL FRONT TO MOVE ACROSS NORTHEASTERN COLORADO WHICH COULD INCREASE PRECIPITATION CHANCES MAINLY ACROSS THE FOOTHILLS AND PALMER DIVIDE. THE GFS HAS ONE OF THESE FRONTS MOVING INTO REGION ON THURSDAY WITH BOTH THE ECMWF AND GFS SHOWING ANOTHER FRONTAL PASSAGE ON SATURDAY. FOR NOW IT NEARLY IMPOSSIBLE TO PINPOINT THE TIMING OF THESE FRONTS AND THEIR IMPACT ON NORTHEASTERN COLORADO...THEREFORE HAVE ONLY MADE MINOR ADJUSTMENTS TO POPS.&& .AVIATION...(FOR THE TAFS THROUGH 00Z SATURDAY LATE AFTERNOON) ISSUED AT 213 PM MDT FRI JUN 19 2015 VFR CONDITIONS OVER THE NEXT 24 HRS. LGT ESELY WINDS THIS AFTN WILL TRANSITION TO S/SWLY THIS EVENING. THE WINDS MAY BECOME MORE WESTERLY BY 12Z SATURDAY AHEAD OF AN APPROACHING FRONTAL BOUNDARY. THIS FRONT SHOULD PUSH THROUGH DENVER AROUND 15Z. COULD SEE SOME PATCHY STRATUS CLOUDS WITH THE FRONT...WITH ISOLD TSTMS POSSIBLE AFTER 22Z IN THE AFTN WITH INCREASING LOW LEVEL MOISTURE FOLLOWING FROPA. AMS COULD BE TOO CAPPED SO WL MENTION STORMS IN THE PUBLIC FORECAST BUT KEEP IT OUT OF THE DENVER TERMINAL FORECASTS. && .AVIATION...(FOR THE TAFS THROUGH 06Z SATURDAY EVENING) ISSUED AT 630 PM MDT FRI JUN 19 2015 VFR CONDITIONS OVER THE NEXT 24 HRS. A STRONGER SOUTHEASTERLY PUSH MOVED THROUGH THE AIRPORTS...WILL EXPECT THESE SPEEDS TO LIGHTEN OVER THE NEXT COUPLE HOURS BEFORE TRANSITIONING TO S/SWLY THIS EVENING. THE WINDS MAY BECOME MORE WESTERLY BY 12Z SATURDAY AHEAD OF AN APPROACHING FRONTAL BOUNDARY. THIS FRONT SHOULD PUSH THROUGH DENVER BETWEEN AROUND 15Z. MODEL SOUNDINGS SHOWING SOME PATCHY STRATUS CLOUDS AHEAD AND WITH THE FRONT...ONLY INCLUDED IT IN KDEN. FRONT SHOULD CAP THE AIRMASS...HOWEVER INCREASING LOW LEVEL MOISTURE MAY ALLOW FOR ISOLATED TSTMS POSSIBLE AFTER 22Z IN THE AFTERNOON. MENTION OF STORMS IN THE PUBLIC FORECAST BUT KEEP IT OUT OF THE DENVER TERMINAL FORECASTS AS CONFIDENCE IS LOW. && .HYDROLOGY... ISSUED AT 213 PM MDT FRI JUN 19 2015 MOUNTAIN TEMPERATURES WILL REMAIN WARM INTO THE WEEKEND...SO RAPID SNOWMELT WILL CONTINUE. HEADWATER STREAMS WILL REMAIN HIGH AND MAY BE SLIGHTLY HIGHER OVER THE NEXT FEW DAYS THAN THEY HAVE BEEN. AS THIS WATER MOVES DOWNSTREAM THE LARGER RIVERS WILL ALSO REMAIN HIGH AND MAY SEE ADDITIONAL SLIGHT RISES THIS WEEKEND INTO EARLY NEXT WEEK. LITTLE OR NO RAINFALL IS EXPECTED THROUGH EARLY NEXT WEEK. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KRIEDERMAN SHORT TERM...COOPER LONG TERM...JK AVIATION...KRIEDERMAN HYDROLOGY...COOPER
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
245 PM MDT FRI JUN 19 2015 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 213 PM MDT FRI JUN 19 2015 AN UPPER LEVEL RIDGE WILL REMAIN OVER THE DESERT SOUTHWEST WITH A DRY WESTERLY FLOW ALOFT OVER COLORADO. OVERALL THE AIRMASS IS CAPPED...BUT HRRR RUNS STILL DEVELOPS SOME THUNDERSTORMS LATE THIS AFTN/EVNG. MOST LIKELY LOCATION WOULD APPEAR BE THE FAR NORTHEAST PLAINS WHERE THE BEST LOW LEVEL MOISTURE AND VERTICAL SHEAR WILL BE. COVERAGE WILL BE ISOLATED BUT THE ONE OR TWO STORMS THAT DO FORM COULD PRODUCE HAIL TO ONE INCH. A COOL FRONT IS PROGGED TO PUSH SOUTHWARD INTO THE NORTHEAST PLAINS LATE TONIGHT AND SATURDAY MORNING. AS A RESULT...TEMPERATURES WILL NOT BE AS HOT BUT STILL ABOVE NORMAL FOR THIS TIME OF YEAR. COULD SEE SOME SCATTERED STRATUS CLOUDS WITH THE FRONT IN THE MORNING NORTH AND EAST OF DENVER. THE FRONT WILL BECOME STATIONARY ALONG THE FOOTHILLS/PALMER DIVIDE. MAYBE ENOUGH MOISTURE/CONVERGENCE TO TRIGGER ISOLATED THUNDERSTORM COVERAGE FM THE FRONT RANGE FOOTHILLS EASTWARD BY LATE IN THE AFTN. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 213 PM MDT FRI JUN 19 2015 A FLAT UPPER LEVEL RIDGE OF HIGH PRESSURE WILL DOMINATE THE SOUTHERN AND CENTRAL ROCKIES SATURDAY NIGHT THROUGH TUESDAY...WITH A DRY WESTERLY FLOW ALOFT OVER COLORADO. THIS PATTERN WILL BRING HOT AND DRY WEATHER TO NORTH CENTRAL AND NORTHEASTERN COLORADO. THE ONLY EXCEPTION MAY BE A FEW THUNDERSTORMS ACROSS THE PLAINS SATURDAY NIGHT ASSOCIATED WITH AN UPPER LEVEL DISTURBANCE. ONE OR TWO OF THE STORMS COULD BE STRONG TO SEVERE IF THE CAP CAN BE BROKEN. ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS MAY RETURN TO THE REGION TUESDAY NIGHT THROUGH WEDNESDAY NIGHT AS THE UPPER RIDGE SHIFTS INTO THE SOUTHWESTERN U.S AND SUBTROPICAL MOISTURE BEGINS TO FLOW INTO COLORADO FROM THE SOUTH. MODELS SHOW THE UPPER RIDGE REBUILDING OVER THE SOUTHWESTERN STATES ON THURSDAY...WITH A DRY NORTHWEST FLOW ALOFT SETTING UP OVER COLORADO. THIS PATTERN WOULD ALLOW OCCASIONAL COOL FRONT TO MOVE ACROSS NORTHEASTERN COLORADO WHICH COULD INCREASE PRECIPITATION CHANCES MAINLY ACROSS THE FOOTHILLS AND PALMER DIVIDE. THE GFS HAS ONE OF THESE FRONTS MOVING INTO REGION ON THURSDAY WITH BOTH THE ECMWF AND GFS SHOWING ANOTHER FRONTAL PASSAGE ON SATURDAY. FOR NOW IT NEARLY IMPOSSIBLE TO PINPOINT THE TIMING OF THESE FRONTS AND THEIR IMPACT ON NORTHEASTERN COLORADO...THEREFORE HAVE ONLY MADE MINOR ADJUSTMENTS TO POPS.&& .AVIATION...(FOR THE TAFS THROUGH 00Z SATURDAY LATE AFTERNOON) ISSUED AT 213 PM MDT FRI JUN 19 2015 VFR CONDITIONS OVER THE NEXT 24 HRS. LGT ESELY WINDS THIS AFTN WILL TRANSITION TO S/SWLY THIS EVENING. THE WINDS MAY BECOME MORE WESTERLY BY 12Z SATURDAY AHEAD OF AN APPROACHING FRONTAL BOUNDARY. THIS FRONT SHOULD PUSH THROUGH DENVER AROUND 15Z. COULD SEE SOME PATCHY STRATUS CLOUDS WITH THE FRONT...WITH ISOLD TSTMS POSSIBLE AFTER 22Z IN THE AFTN WITH INCREASING LOW LEVEL MOISTURE FOLLOWING FROPA. AMS COULD BE TOO CAPPED SO WL MENTION STORMS IN THE PUBLIC FORECAST BUT KEEP IT OUT OF THE DENVER TERMINAL FORECASTS. && .HYDROLOGY... ISSUED AT 213 PM MDT FRI JUN 19 2015 MOUNTAIN TEMPERATURES WILL REMAIN WARM INTO THE WEEKEND...SO RAPID SNOWMELT WILL CONTINUE. HEADWATER STREAMS WILL REMAIN HIGH AND MAY BE SLIGHTLY HIGHER OVER THE NEXT FEW DAYS THAN THEY HAVE BEEN. AS THIS WATER MOVES DOWNSTREAM THE LARGER RIVERS WILL ALSO REMAIN HIGH AND MAY SEE ADDITIONAL SLIGHT RISES THIS WEEKEND INTO EARLY NEXT WEEK. LITTLE OR NO RAINFALL IS EXPECTED THROUGH EARLY NEXT WEEK. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...COOPER LONG TERM...JK AVIATION...COOPER HYDROLOGY...COOPER
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1145 AM MDT FRI JUN 19 2015 .UPDATE... ISSUED AT 935 AM MDT FRI JUN 19 2015 REMOVED MORNING FOG AND LOADED IN LATEST OBSERVATION DATA...UPDATED FIRE WEATHER GRIDS FOR TODAY. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 400 AM MDT FRI JUN 19 2015 ZONAL FLOW WILL REMAIN OVER THE AREA THROUGH THE NEXT 24 HOURS AS THE UPPER RIDGE OVER CO GETS FLATTENED AS ENERGY ENTERING THE PACIFIC NORTHWEST TRANSLATES ACROSS WY AND MT LATE THIS AFTERNOON THROUGH TONIGHT. LEE TROF STRENGTHS ALONG THE I-25 CORRIDOR...INCREASING SOUTHERLY FLOW ACROSS THE PLAINS...AND MIXING OUT SFC DEW POINTS. QUESTION WILL BE...BY HOW MUCH. EARLY MORNING RUNS OF THE HRRR ARE QUITE DRY WITH AFTERNOON DEW POINTS DROPPING INTO THE 30S ACROSS MUCH OF THE SOUTHEAST PLAINS...WITH 20S ACROSS THE MOUNTAINS. GFS AND RAP13 AGREE...BUT NAM12...AND NMM AND ARW KEEP DEW POINTS IN THE 40S TO LOWER 50S ACROSS THE PLAINS. GIVEN ALL THE RAINFALL LATELY...HAVE SIDED WITH THESE MOISTER RUNS...WHICH LEANS FORECAST TOWARDS THE SLIGHTLY COOLER SIDE OF GUIDANCE VALUES. ACROSS THE MOUNTAINS...SHOULD SEE CONDITIONS SIMILAR TO A DEGREE OR TWO WARMER. ALL MODELS SUGGEST THUNDERSTORM COVERAGE SHOULD BE MORE LIMITED TODAY...AND WITH DRIER AIR SPREADING INTO THE MOUNTAIN AREAS...THIS LOOKS REASONABLE. RETAINED GENERALLY ISOLATED POPS ACROSS THE MOUNTAINS...THOUGH SOUTHERN SANGRE DE CRISTO MTS AND NRN RATON MESA REGION MAY SEE SLIGHTLY BETTER COVERAGE...SO HAVE SCATTERED POPS DOWN THAT WAY. CAPES LOOK FAIRLY LIMITED ACROSS THE MTS/I-25 CORRIDOR REGION. ONE AREA TO WATCH WILL BE FAR EASTERN PLAINS WHERE HIGHER DEW POINTS ALONG AND EAST OF A DRY LINE COULD RESULT IN CAPE VALUES OF AROUND 1000-1500 J/KG. 0-6KM SHEAR WILL BE PRETTY WEAK THOUGH WITH LOW LEVEL FLOW MORE SOUTHERLY...SO IF STORMS CAN FIRE ALONG THIS BOUNDARY...THEY SHOULD BE PULSE IN NATURE...WHICH SHOULD LIMIT ANY SEVERE POTENTIAL. BRIEF HEAVY RAINFALL WILL STILL BE POSSIBLE WITH THUNDERSTORMS TODAY AS WELL...BUT THIS THREAT SHOULD BE HIGHLY LOCALIZED. OTHERWISE...THUNDERSTORMS SHOULD DIMINISH DURING THE EVENING WITH CLEARING SKIES. -KT .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 400 AM MDT FRI JUN 19 2015 ...HOT AND DRY THROUGH THE EXTENDED... LITTLE CHANGE TO THE ONGOING TREND FOR THE LONG TERM. AN UPPER RIDGE OF HIGH PRESSURE BUILDS ACROSS THE DESERT SW OVER THE WEEKEND...THEN SLIDES EAST ACROSS THE REGION AND INTO THE CENTRAL PORTIONS OF THE U.S. BY TUE. THIS WILL KEEP HOT AND PREDOMINANTLY DRY CONDITIONS IN PLACE FOR THE FORECAST AREA THROUGH TUE...WITH MAX TEMPS EACH DAY IN THE 90S TO NEAR 100F FOR THE PLAINS...AND 80S FOR THE HIGH VALLEYS. ISOLATED DIURNAL CONVECTION...MAINLY HIGH BASED...IS EXPECTED EACH DAY OVER THE HIGHER TERRAIN...WITH LITTLE CHANCE OF A WETTING RAIN BUT A BETTER CHANCE FOR GUSTY WINDS. BEGINNING LATE TUE EVE...BOTH THE GFS AND EC MODELS CONTINUE TO HINT AT THE POSSIBILITY OF A MONSOON-LIKE TAP OF MOISTURE DEVELOPING...GIVING THE CWA A BETTER SHOT AT SOME PCPN. MOORE && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1142 AM MDT FRI JUN 19 2015 VFR CONDITIONS ARE EXPECTED AT THE TAFS SITES THROUGHOUT THE PERIOD. LATE THIS AFTERNOON AND INTO THE EARLY EVENING...IT IS POSSIBLE A THUNDERSTORM COULD MOVE INTO THE VCNTY OF KALS. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...28 SHORT TERM...KT LONG TERM...MOORE AVIATION...28
AREA FORECAST DISCUSSION
NWS PUEBLO CO
938 AM MDT FRI JUN 19 2015 .UPDATE... ISSUED AT 935 AM MDT FRI JUN 19 2015 REMOVED MORNING FOG AND LOADED IN LATEST OBSERVATION DATA...UPDATED FIRE WEATHER GRIDS FOR TODAY. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 400 AM MDT FRI JUN 19 2015 ZONAL FLOW WILL REMAIN OVER THE AREA THROUGH THE NEXT 24 HOURS AS THE UPPER RIDGE OVER CO GETS FLATTENED AS ENERGY ENTERING THE PACIFIC NORTHWEST TRANSLATES ACROSS WY AND MT LATE THIS AFTERNOON THROUGH TONIGHT. LEE TROF STRENGTHS ALONG THE I-25 CORRIDOR...INCREASING SOUTHERLY FLOW ACROSS THE PLAINS...AND MIXING OUT SFC DEW POINTS. QUESTION WILL BE...BY HOW MUCH. EARLY MORNING RUNS OF THE HRRR ARE QUITE DRY WITH AFTERNOON DEW POINTS DROPPING INTO THE 30S ACROSS MUCH OF THE SOUTHEAST PLAINS...WITH 20S ACROSS THE MOUNTAINS. GFS AND RAP13 AGREE...BUT NAM12...AND NMM AND ARW KEEP DEW POINTS IN THE 40S TO LOWER 50S ACROSS THE PLAINS. GIVEN ALL THE RAINFALL LATELY...HAVE SIDED WITH THESE MOISTER RUNS...WHICH LEANS FORECAST TOWARDS THE SLIGHTLY COOLER SIDE OF GUIDANCE VALUES. ACROSS THE MOUNTAINS...SHOULD SEE CONDITIONS SIMILAR TO A DEGREE OR TWO WARMER. ALL MODELS SUGGEST THUNDERSTORM COVERAGE SHOULD BE MORE LIMITED TODAY...AND WITH DRIER AIR SPREADING INTO THE MOUNTAIN AREAS...THIS LOOKS REASONABLE. RETAINED GENERALLY ISOLATED POPS ACROSS THE MOUNTAINS...THOUGH SOUTHERN SANGRE DE CRISTO MTS AND NRN RATON MESA REGION MAY SEE SLIGHTLY BETTER COVERAGE...SO HAVE SCATTERED POPS DOWN THAT WAY. CAPES LOOK FAIRLY LIMITED ACROSS THE MTS/I-25 CORRIDOR REGION. ONE AREA TO WATCH WILL BE FAR EASTERN PLAINS WHERE HIGHER DEW POINTS ALONG AND EAST OF A DRY LINE COULD RESULT IN CAPE VALUES OF AROUND 1000-1500 J/KG. 0-6KM SHEAR WILL BE PRETTY WEAK THOUGH WITH LOW LEVEL FLOW MORE SOUTHERLY...SO IF STORMS CAN FIRE ALONG THIS BOUNDARY...THEY SHOULD BE PULSE IN NATURE...WHICH SHOULD LIMIT ANY SEVERE POTENTIAL. BRIEF HEAVY RAINFALL WILL STILL BE POSSIBLE WITH THUNDERSTORMS TODAY AS WELL...BUT THIS THREAT SHOULD BE HIGHLY LOCALIZED. OTHERWISE...THUNDERSTORMS SHOULD DIMINISH DURING THE EVENING WITH CLEARING SKIES. -KT .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 400 AM MDT FRI JUN 19 2015 ...HOT AND DRY THROUGH THE EXTENDED... LITTLE CHANGE TO THE ONGOING TREND FOR THE LONG TERM. AN UPPER RIDGE OF HIGH PRESSURE BUILDS ACROSS THE DESERT SW OVER THE WEEKEND...THEN SLIDES EAST ACROSS THE REGION AND INTO THE CENTRAL PORTIONS OF THE U.S. BY TUE. THIS WILL KEEP HOT AND PREDOMINANTLY DRY CONDITIONS IN PLACE FOR THE FORECAST AREA THROUGH TUE...WITH MAX TEMPS EACH DAY IN THE 90S TO NEAR 100F FOR THE PLAINS...AND 80S FOR THE HIGH VALLEYS. ISOLATED DIURNAL CONVECTION...MAINLY HIGH BASED...IS EXPECTED EACH DAY OVER THE HIGHER TERRAIN...WITH LITTLE CHANCE OF A WETTING RAIN BUT A BETTER CHANCE FOR GUSTY WINDS. BEGINNING LATE TUE EVE...BOTH THE GFS AND EC MODELS CONTINUE TO HINT AT THE POSSIBILITY OF A MONSOON-LIKE TAP OF MOISTURE DEVELOPING...GIVING THE CWA A BETTER SHOT AT SOME PCPN. MOORE && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 400 AM MDT FRI JUN 19 2015 NORTHERN PORTIONS OF THE SOUTHEAST PLAINS WILL SEE LOCAL IFR/LIFR CIGS/VIS DUE TO FOG AND STRATUS THROUGH THE EARLY MORNING...WHICH COULD AFFECT THE KCOS TAF SITE. BASED ON LATEST SATELLITE TRENDS...WILL CARRY THIS IN A TEMPO GROUP THROUGH 13Z. SOUTHERLY WINDS WILL INCREASE TODAY FOR THE TAF SITES WITH WITH SPEEDS UNDER 15 KTS. ISOLATED THUNDERSTORMS SHOULD STAY CONFINED TO THE MOUNTAIN AREAS TODAY AND BE SPOTTIER IN COVERAGE THAN THE PAST FEW DAYS. WILL NOT INCLUDE VCTS IN THE TAFS SINCE THESE ARE NOT LIKELY TO IMPACT THE TERMINALS. -KT && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...28 SHORT TERM...KT LONG TERM...MOORE AVIATION...KT
AREA FORECAST DISCUSSION
NWS PUEBLO CO
400 AM MDT FRI JUN 19 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 400 AM MDT FRI JUN 19 2015 ZONAL FLOW WILL REMAIN OVER THE AREA THROUGH THE NEXT 24 HOURS AS THE UPPER RIDGE OVER CO GETS FLATTENED AS ENERGY ENTERING THE PACIFIC NORTHWEST TRANSLATES ACROSS WY AND MT LATE THIS AFTERNOON THROUGH TONIGHT. LEE TROF STRENGTHS ALONG THE I-25 CORRIDOR...INCREASING SOUTHERLY FLOW ACROSS THE PLAINS...AND MIXING OUT SFC DEW POINTS. QUESTION WILL BE...BY HOW MUCH. EARLY MORNING RUNS OF THE HRRR ARE QUITE DRY WITH AFTERNOON DEW POINTS DROPPING INTO THE 30S ACROSS MUCH OF THE SOUTHEAST PLAINS...WITH 20S ACROSS THE MOUNTAINS. GFS AND RAP13 AGREE...BUT NAM12...AND NMM AND ARW KEEP DEW POINTS IN THE 40S TO LOWER 50S ACROSS THE PLAINS. GIVEN ALL THE RAINFALL LATELY...HAVE SIDED WITH THESE MOISTER RUNS...WHICH LEANS FORECAST TOWARDS THE SLIGHTLY COOLER SIDE OF GUIDANCE VALUES. ACROSS THE MOUNTAINS...SHOULD SEE CONDITIONS SIMILAR TO A DEGREE OR TWO WARMER. ALL MODELS SUGGEST THUNDERSTORM COVERAGE SHOULD BE MORE LIMITED TODAY...AND WITH DRIER AIR SPREADING INTO THE MOUNTAIN AREAS...THIS LOOKS REASONABLE. RETAINED GENERALLY ISOLATED POPS ACROSS THE MOUNTAINS...THOUGH SOUTHERN SANGRE DE CRISTO MTS AND NRN RATON MESA REGION MAY SEE SLIGHTLY BETTER COVERAGE...SO HAVE SCATTERED POPS DOWN THAT WAY. CAPES LOOK FAIRLY LIMITED ACROSS THE MTS/I-25 CORRIDOR REGION. ONE AREA TO WATCH WILL BE FAR EASTERN PLAINS WHERE HIGHER DEW POINTS ALONG AND EAST OF A DRY LINE COULD RESULT IN CAPE VALUES OF AROUND 1000-1500 J/KG. 0-6KM SHEAR WILL BE PRETTY WEAK THOUGH WITH LOW LEVEL FLOW MORE SOUTHERLY...SO IF STORMS CAN FIRE ALONG THIS BOUNDARY...THEY SHOULD BE PULSE IN NATURE...WHICH SHOULD LIMIT ANY SEVERE POTENTIAL. BRIEF HEAVY RAINFALL WILL STILL BE POSSIBLE WITH THUNDERSTORMS TODAY AS WELL...BUT THIS THREAT SHOULD BE HIGHLY LOCALIZED. OTHERWISE...THUNDERSTORMS SHOULD DIMINISH DURING THE EVENING WITH CLEARING SKIES. -KT .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 400 AM MDT FRI JUN 19 2015 ...HOT AND DRY THROUGH THE EXTENDED... LITTLE CHANGE TO THE ONGOING TREND FOR THE LONG TERM. AN UPPER RIDGE OF HIGH PRESSURE BUILDS ACROSS THE DESERT SW OVER THE WEEKEND...THEN SLIDES EAST ACROSS THE REGION AND INTO THE CENTRAL PORTIONS OF THE U.S. BY TUE. THIS WILL KEEP HOT AND PREDOMINANTLY DRY CONDITIONS IN PLACE FOR THE FORECAST AREA THROUGH TUE...WITH MAX TEMPS EACH DAY IN THE 90S TO NEAR 100F FOR THE PLAINS...AND 80S FOR THE HIGH VALLEYS. ISOLATED DIURNAL CONVECTION...MAINLY HIGH BASED...IS EXPECTED EACH DAY OVER THE HIGHER TERRAIN...WITH LITTLE CHANCE OF A WETTING RAIN BUT A BETTER CHANCE FOR GUSTY WINDS. BEGINNING LATE TUE EVE...BOTH THE GFS AND EC MODELS CONTINUE TO HINT AT THE POSSIBILITY OF A MONSOON-LIKE TAP OF MOISTURE DEVELOPING...GIVING THE CWA A BETTER SHOT AT SOME PCPN. MOORE && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 400 AM MDT FRI JUN 19 2015 NORTHERN PORTIONS OF THE SOUTHEAST PLAINS WILL SEE LOCAL IFR/LIFR CIGS/VIS DUE TO FOG AND STRATUS THROUGH THE EARLY MORNING...WHICH COULD AFFECT THE KCOS TAF SITE. BASED ON LATEST SATELLITE TRENDS...WILL CARRY THIS IN A TEMPO GROUP THROUGH 13Z. SOUTHERLY WINDS WILL INCREASE TODAY FOR THE TAF SITES WITH WITH SPEEDS UNDER 15 KTS. ISOLATED THUNDERSTORMS SHOULD STAY CONFINED TO THE MOUNTAIN AREAS TODAY AND BE SPOTTIER IN COVERAGE THAN THE PAST FEW DAYS. WILL NOT INCLUDE VCTS IN THE TAFS SINCE THESE ARE NOT LIKELY TO IMPACT THE TERMINALS. -KT && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...KT LONG TERM...MOORE AVIATION...KT
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1131 PM MDT THU JUN 18 2015 .UPDATE... ISSUED AT 908 PM MDT THU JUN 18 2015 UPDATED TO END SVR THUNDERSTORM WATCH 310 FOR BACA COUNTY. KEPT ISOLATED POPS ACROSS THE EASTERN MTS AND PLAINS THROUGH MIDNIGHT WITH ONGOING CONVECTION ACROSS THE SOUTHERN SANGRE DE CRISTO MTS AND ACROSS THE NORTHERN FRONT RANGE ATTM. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 215 PM MDT THU JUN 18 2015 AN OUTFLOW BOUNDARY MOVED THRU MUCH OF THE SERN PLAINS TODAY AND IS SITTING OVR THE SE CORNER OF THE STATE. BEHIND THIS BOUNDARY...DEW POINTS ARE MOSTLY IN THE MID TO UPR 50S...AND WARMING HAS BEEN SLOWED. CONVECTION HAS BEEN VERY LIMITED SO FAR THIS AFTERNOON... WITH JUST SOME ISOLD STORMS OVR THE SRN MTNS. SPC MESO ANALYSIS INDICATES CAPE VALUES OF 2000-3000 J/KG OVR A GOOD SHARE OF THE SERN PLAINS...NOT INCLUDING LAS ANIMAS COUNTY. 0-6KM SHEAR VALUES ARE ABOUT 40 KTS NR THE KS BORDER. WITH THE BOUNDARY SITTING OVR THE SERN CORNER OF THE STATE...IT WL SERVE AS FOCUS FOR TSTMS DEVELOPMENT...AND THIS AREA WL HAVE THE BEST CHANCE FOR SEVERE STORMS AND THUS A SEVERE TSTM WATCH WL REMAIN IN EFFECT FOR BACA COUNTY. THE HRRR SHOWS THE BEST CHANCES FOR TSTMS OVR THE SERN CORNER INTO EARLY EVENING AND THEN MOVING SOUTH OF THE BORDER. IN THE LATE AFTERNOON/EARLY EVENING HOURS...THE HRRR ALSO SHOWS TSTMS ALONG THE ERN MTNS WORKING THEIR WAY EASTWARD. VERY LITTLE CHANCE FOR PCPN IS EXPECTED OVR WRN PORTIONS OF THE FORECAST AREA THIS EVENING. ON FRI A WEAK UPR RIDGE WL BE OVR THE AREA...WITH CONDITIONS EXPECTED TO BE A BIT DRIER. CHANCES FOR CONVECTION SHOULD BE ISOLD AND MAINLY CONFINED TO OVR AND NR THE MTNS AND MAYBE ACRS THE SRN BORDER AREA IN LAS ANIMAS COUNTY. H7 TEMPS ACRS THE FORECAST AREA FRI AFTERNOON ARE EXPECTED TO RANGE FROM ABOUT 17C-20C. AFTERNOON HIGHS SHOULD BE IN THE 90S ACRS THE SERN PLAINS AND IN THE 80S OVR THE HIGH VALLEYS. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 215 PM MDT THU JUN 18 2015 ...HOT AND DRY THROUGH AT LEAST TUESDAY... LOOKS LIKE A STABLE SUMMER PATTERN IS HERE TO STAY. A STRONG H5 HIGH WILL BUILD OVER SRN CA THIS WEEKEND AND THEN DRIFT SLOWLY EWD OVER NRN NM EARLY NEXT WEEK. H7 TEMPS WILL CLIMB FROM AROUND 16 DEG C EARLY IN THE PERIOD TO 20 DEGREES OR MORE BY THE END OF THE WEEKEND AND EARLY NEXT WEEK. DURING THIS TIME...NOT EXPECTING MUCH IN THE WAY OF CONVECTION WITH VERY DRY AIR MOVING IN FROM THE SW. CANNOT RULE OUT SOME LOCAL BUILD-UPS OVR THE MTS...AND MAYBE SOME VIRGA...BUT MEASURABLE PRECIP WILL BE TOUGH TO COME BY. SO...HAVE DROPPED POPS BELOW MENTIONABLE THRESHOLDS...MAINTAINING ONLY SINGLE DIGIT POPS ON A DIURNAL BASIS OVER THE MTS. MOS TEMPS REMAIN AT 100 DEGREES OR HIGHER FOR THE PLAINS FROM SUNDAY THROUGH WEDNESDAY. WILL KEEP TEMPS OVER THE LOWER ARKANSAS JUST BELOW 100 SINCE SURFACE DEWS WILL REMAIN RELATIVELY HIGH AND THIS MAY CUT THE HIGH END OFF JUST A BIT. BUT IT WILL BE HOT. HOT AND DRY. BY WED AND BEYOND...SOME DIFFERENCES BETWN THE GFS AND ECMWF AS THE FORMER REBUILDS THE UPPER HIGH OVER THE DESERT SW WHILE THE LATTER BREAKS THINGS DOWN A BIT MORE. BOTH MODELS BRING IN A BIT MORE MOISTURE FROM THE SOUTH...WHICH SHOULD BRING BACK DIURNAL SHOWERS/STORMS AND HOLD HIGH TEMPS DOWN CLOSER TO SEASONAL NORMS. ENSEMBLE BASED TEMPS AND POPS LOOK REASONABLE IN THE EXTENDED...AS WE SLOWLY HEAD TOWARD MORE OF A MID-SUMMER REGIME WITH THE MONSOON RIGHT AROUND THE CORNER. ROSE && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1131 PM MDT THU JUN 18 2015 VFR CONDITIONS EXPECTED AT COS...PUB AND ALS OVER THE NEXT 24 HOURS...THOUGH CAN NOT RULE OUT SOME PATCHY GROUND FOG AT COS THROUGH THE EARLY MORNING HOURS...WITH DEW PTS IN THE MID TO UPPER 50S AT THIS TIME. WARMER AND DRIER AIR CONTINUES TO MOVE IN FROM WEST TO EAST ACROSS THE AREA...AS UPPER LEVEL RIDGING BUILDS ACROSS THE STATE. THIS WILL LEAD TO MUCH MORE ISOLATED CONVECTION TOMORROW AFTERNOON AND EARLY EVENING...WHICH LOOKS TO REMAIN OVER THE HIGHER TERRAIN. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...MW SHORT TERM...28 LONG TERM...ROSE AVIATION...MW
AREA FORECAST DISCUSSION
NWS ALBANY NY
1030 PM EDT SAT JUN 20 2015 .SYNOPSIS... THE REMNANTS OF TROPICAL STORM BILL WILL IMPACT THE REGION TONIGHT INTO SUNDAY BRINGING A MODERATE TO HEAVY RAINFALL TO AREAS TO THE SOUTH AND EAST OF THE CAPITAL DISTRICT. A LOW PRESSURE SYSTEM WILL APPROACH THE REGION TONIGHT AND MOVE ACROSS THE AREA SUNDAY AND SUNDAY NIGHT TRIGGERING SHOWERS AND THUNDERSTORMS MAINLY DURING THE AFTERNOON INTO THE EVENING HOURS. SOME THUNDERSTORMS MAYBE STRONG TO POSSIBLY SEVERE TO THE NORTH AND WEST OF THE CAPITAL DISTRICT. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... AS OF 1030 PM EDT...RADAR CONTINUES TO SHOW RAINFALL SPREADING INTO THE CATSKILLS AND HUDSON VALLEY FROM CENTRAL NY. MOST OF THIS RAINFALL IS FAIRLY LIGHT IN INTENSITY...WITH SPOTTY SHOWERS ELSEWHERE. AT THIS TIME...THE HEAVIEST AND STEADIEST RAINFALL IS REMAINING TO THE SOUTH ACROSS CENTRAL/EASTERN PA...WITH HEAVY THUNDERSTORM ACTIVITY ACROSS EASTERN PA/MD/DE. THE REMNANTS OF TC BILL PASSING TO THE SOUTH WILL COMBINE WITH THE RETURN FLOW AROUND A DEPARTING HIGH TO HELP PWATS RISE. THEY ARE EXPECTED TO INCREASE TO 1 1/2+ INCHES ACROSS THE FORECAST AREA WITH AROUND 2 INCHES ACROSS THE SOUTHERN MOST PORTION AS THE REMNANTS OF BILL MOVE ACROSS THE MID ATLANTIC REGION TOWARD THE NEW YORK METROPOLITAN AREA FOR LATER TONIGHT. THE NEW 00Z NAM...AS WELL AS THE 3KM HRRR GUIDANCE...ALL SUGGEST STEADY AND HEAVIER RAINFALL WILL SPREAD INTO OUR REGION LATE TONIGHT...AS THE LOW PASSES SUCH SOUTH OF THE AREA...AND THE HEAVY PRECIP OVER PA STARTS TO ROTATE TOWARDS OUR REGION. THIS WILL ESPECIALLY BE TRUE FOR AREAS FROM THE CAPITAL REGION ON SOUTHWARD. RAINFALL LOOKS TO BE FAIRLY STEADY FOR THE LATE NIGHT HOURS...AND MAY BE LOCALLY HEAVY FOR FAR SOUTHERN AREAS. INSTABILITY WILL BE LIMITED...BUT CANNOT RULE OUT A RUMBLE OF THUNDER IN A FEW SPOTS DUE TO SOME SMALL AMOUNTS OF ELEVATED INSTABILITY IN PLACE. NO FLOOD WATCH HAS BEEN ISSUED SINCE RAIN RATES WON/T APPEAR TO EXCEED FLASH FLOOD GUIDANCE. STILL...SOME PONDING OF WATER ON ROADWAYS AND IN URBAN AND LOW LYING AREAS MAY STILL OCCUR IN A FEW LOCATIONS...AND THIS WILL CONTINUE TO BE HIGHLIGHTED IN THE HWO STATEMENT. THIS RAINFALL WILL BE HELPING ACROSS THESE SOUTHERN AND EASTER AREAS...AS THE ANNUAL DEPARTURE FROM NORMAL FOR POUGHKEEPSIE NY STANDS AT -7.62 INCHES AND IS PITTSFIELD MA -4.18 INCHES. OVERNIGHT LOWS WILL MAINLY BE IN THE 60S...ALONG WITH THE MUGGY AND CLOUDY CONDITIONS. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/... THE REMNANTS OF BILL ARE EXPECTED TO TRACK TO ACROSS THE NEW YORK METRO AREA AND LONG ISLAND AND WILL CONTINUE TO IMPACTS MAINLY THE AREAS TO THE SOUTH AND EAST OF THE CAPITAL DISTRICT THROUGH THE MORNING INTO THE EARLY AFTERNOON HOURS. A SHORT WAVE TROUGH AND LOW PRESSURE SYSTEM MOVING THROUGH THE FAST ZONAL FLOW WILL BE ON THE APPROACH FOR SUNDAY. THE SYSTEM`S WARM FRONT IS EXPECTED TO LIFT ACROSS THE REGION SUNDAY PLACING US IN THE WARM SECTOR. THE AMOUNT OF INSTABILITY IS THE BIG QUESTION. FLOW WILL BE UNIDIRECTIONAL WITH SHEAR INCREASING AS THE AFTERNOON PROGRESSES INTO THE EVENING HOURS. IF THERE IS ENOUGH INSTABILITY TO WORK MULTICELLS CLUSTERS SHOULD FORM. HOWEVER GUIDANCE IS NOT IN AGREEMENT ABOUT HOW STEEP THE LAPSE RATES SHOULD GET. THE STORM PREDICTION CENTER HAS UPGRADED THE SEVERE WEATHER RISK TO SLIGHT FOR MUCH OF EAST CENTRAL NEW YORK...FOR AREAS TO THE NORTH AND WEST OF THE CAPITAL DISTRICT...WITH THE REST OF THE FORECAST AREA UNDER A MARGINAL RISK. HAVE ENHANCED WORDING IN THE FORECAST FOR GUSTY WINDS...SMALL HAIL AND HEAVY RAINFALL ADDRESSING THE THREAT. CHANCES FOR STORMS WILL DECREASE OVERNIGHT SUNDAY INTO MONDAY AS THE SHORT WAVE MOVES OFF TO OUR EAST. SOME RIDGING WILL BRIEFLY BUILD IN BETWEEN SHORT WAVES RESULTING IN MAINLY FAIR WEATHER WITH SEASONABLE TEMPERATURES MONDAY. && .LONG TERM /TUESDAY THROUGH SATURDAY/... THIS WILL BE A PREDOMINANTLY WET PERIOD WITH MAINLY SEASONABLE TEMPERATURES. THE ONLY DRY PERIOD IS EXPECTED TO RUN FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. THERE WILL BE PERIODS OF SUNSHINE... BUT ASIDE FROM TUESDAY...INSTABILITY AND MOISTURE WILL BE LIMITED...SO THE MENTION IS FOR JUST SHOWERS. HIGH TEMPERATURES WILL START OFF TUESDAY FROM AROUND 70 DEGREES IN THE WESTERN ADIRONDACKS...TO THE UPPER 80S IN THE LOWER MID HUDSON VALLEY...BUT WILL GRADUALLY COOL DOWN...TO HIGHS RANGING FROM THE MID 60S TO MID 70S BY FRIDAY. SATURDAY WILL AVERAGE ONLY SLIGHTLY WARMER. TUESDAY NIGHT WILL BE MILDEST...WITH LOWS FROM THE MID 50S TO LOWER 60S. BY FRIDAY NIGHT...LOWS WILL RANGE FROM AROUND 50 DEGREES IN THE NORTHERN HIGH PEAKS...TO THE UPPER 50S IN THE MID HUDSON VALLEY. NORMAL HIGHS AND LOWS FOR ALBANY DURING THIS PERIOD ARE LOWER 80S AND AROUND 59 DEGREES...RESPECTIVELY. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/... FLYING CONDITIONS HAVE LOWERED DOWN TO MVFR CONDITIONS FOR CIGS FOR ALL SITES DUE TO ABUNDANT LOW LEVEL MOISTURE CAUSING PLENTY OF LOW STRATUS TO FORM. OVER THE NEXT FEW HOURS...RAIN SHOWERS WILL SPREAD ACROSS THE REGION FROM THE WEST. THIS WILL DROP VSBYS DOWN TO MVFR LEVELS AS WELL...AND EVENTUALLY IFR CONDITIONS FOR BOTH VSBYS/CIGS BY AROUND MIDNIGHT OR SO. THIS WILL CONTINUE THROUGH THE REMAINDER OF THE OVERNIGHT HOURS...WITH LIGHT TO CALM WINDS. SHOWERS WILL TAPER OFF BY AROUND 6-9 AM OVER THE REGION. IFR CONDITIONS SHOULD END ONCE THE RAIN STOPS...BUT IT MAY TAKE UNTIL THE MID TO LATE MORNING FOR FLYING CONDITIONS TO RETURN TO ABOVE MVFR LEVELS. DURING THE MID TO LATE AFTN HOURS...THERE MAY BE SOME ADDITIONAL SHOWERS OR T-STORMS AROUND...BUT THESE WILL BE RATHER SCT IN NATURE. SOUTHERLY WINDS WILL EVENTUALLY BECOME WESTERLY AROUND 10 KTS OR SO. OUTLOOK... SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. LIKELY SHRA...TSRA. MONDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. MONDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. TUESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. WEDNESDAY: NO OPERATIONAL IMPACT. NO SIG WX. WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. THURSDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. && .FIRE WEATHER... THE REMNANTS OF TROPICAL STORM BILL WILL IMPACT THE REGION TONIGHT INTO SUNDAY BRINGING A MODERATE TO HEAVY RAINFALL TO AREAS TO THE SOUTH AND EAST OF THE CAPITAL DISTRICT. A LOW PRESSURE SYSTEM WILL APPROACH THE REGION TONIGHT AND MOVE ACROSS THE AREA SUNDAY AND SUNDAY NIGHT TRIGGERING SHOWERS AND THUNDERSTORMS MAINLY DURING THE AFTERNOON INTO THE EVENING HOURS. CONDITIONS DRY OUT FOR MONDAY...HOWEVER MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED TUESDAY. && .HYDROLOGY... PWATS WILL BE IN THE RISE AND ARE EXPECTED TO INCREASE TO 1 1/2+ INCHES ACROSS THE FORECAST AREA WITH AROUND 2 INCHES ACROSS THE SOUTHERN MOST PORTION AS THE REMNANTS OF BILL MOVE ACROSS THE MID ATLANTIC REGION TOWARD THE NEW YORK METROPOLITAN AREA. THE GUIDANCE HAS TRENDED A BIT NORTHWARD WITH THE HEAVIER QPF. THE GFS IS THE MOST AGGRESSIVE HOWEVER IT APPEARS TO BE HAVING CONVECTIVE FEEDBACK ISSUES AND CAN BE TRUSTED. A MODERATE TO HEAVY RAINFALL IS EXPECTED TO THE SOUTH AND EAST OF THE CAPITAL DISTRICT AS THE HIGHER PWATS ARRIVE. NO FLOOD WATCH HAS BEEN ISSUED. THE SOUTHEASTERN PORTION OF THE FORECAST UNDER THE SEVERE DROUGHT CATEGORY ON THE U.S. DROUGHT MONITOR. THE ANNUAL DEPARTURE FROM NORMAL FOR POUGHKEEPSIE NY STANDS AT -7.62 INCHES AND IS PITTSFIELD MA -4.18 INCHES. SOME URBAN AND POOR DRAINING FLOODING IS POSSIBLE. PWATS WILL DECREASE SOME SUNDAY AS THE REMNANTS OF BILL MOVE AWAY FROM THE REGION. HOWEVER A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE AREA SUNDAY TRIGGERING SHOWERS AND THUNDERSTORMS. THE FOCUS FOR THIS ACTIVITY WILL BE MAINLY TO THE NORTH AND WEST OF THE CAPITAL DISTRICT SUNDAY AFTERNOON INTO THE EVENING. LOCALLY HEAVY RAINFALL WILL BE POSSIBLE WITH SOME THUNDERSTORMS. CONDITIONS DRY OUT FOR MONDAY...HOWEVER MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED TUESDAY. 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...IAA NEAR TERM...IAA/FRUGIS SHORT TERM...IAA LONG TERM...ELH AVIATION...FRUGIS FIRE WEATHER...IAA HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS ALBANY NY
746 PM EDT SAT JUN 20 2015 .SYNOPSIS... THE REMNANTS OF TROPICAL STORM BILL WILL IMPACT THE REGION TONIGHT INTO SUNDAY BRINGING A MODERATE TO HEAVY RAINFALL TO AREAS TO THE SOUTH AND EAST OF THE CAPITAL DISTRICT. A LOW PRESSURE SYSTEM WILL APPROACH THE REGION TONIGHT AND MOVE ACROSS THE AREA SUNDAY AND SUNDAY NIGHT TRIGGERING SHOWERS AND THUNDERSTORMS MAINLY DURING THE AFTERNOON INTO THE EVENING HOURS. SOME THUNDERSTORMS MAYBE STRONG TO POSSIBLY SEVERE TO THE NORTH AND WEST OF THE CAPITAL DISTRICT. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... AS OF 745 PM EDT...REGIONAL RADAR CONTINUES TO SHOW ONLY A FEW SHOWERS OVER EASTERN UPSTATE NY...BUT MORE ACTIVITY IS BECOMING WIDESPREAD OVER CENTRAL NY AND IS HEADED EAST TO NORTHEAST. BASED ON RADAR TRENDS AND THE LATEST 3KM HRRR GUIDANCE...SHOWERS WILL START TO BECOME MORE WIDESPREAD OVER THE REGION BETWEEN 10 PM AND MIDNIGHT. THE REMNANTS OF TC BILL PASSING TO THE SOUTH WILL COMBINE WITH THE RETURN FLOW AROUND A DEPARTING HIGH TO HELP PWATS RISE. THEY ARE EXPECTED TO INCREASE TO 1 1/2+ INCHES ACROSS THE FORECAST AREA WITH AROUND 2 INCHES ACROSS THE SOUTHERN MOST PORTION AS THE REMNANTS OF BILL MOVE ACROSS THE MID ATLANTIC REGION TOWARD THE NEW YORK METROPOLITAN AREA. THE GUIDANCE HAS TRENDED A BIT NORTHWARD WITH THE HEAVIER QPF. THE GFS IS THE MOST AGGRESSIVE HOWEVER IT APPEARS TO BE HAVING CONVECTIVE FEEDBACK ISSUES AND CAN BE TRUSTED. A MODERATE TO HEAVY RAINFALL IS EXPECTED TO THE SOUTH AND EAST OF THE CAPITAL DISTRICT AS THE HIGHER PWATS ARRIVE FOR LATE TONIGHT. SURFACE BASED INSTABILITY WILL BE LIMITED TONIGHT HOWEVER THERE WILL BE ELEVATED INSTABILITY SO HAVE CHANCES FOR THUNDERSTORMS IN THE FORECAST. THE HEAVIER RAINFALL IS NOT LIMITED TO THUNDERSTORMS. NO FLOOD WATCH HAS BEEN ISSUED SINCE RAIN RATES WON/T APPEAR TO EXCEED FLASH FLOOD GUIDANCE. STILL...SOME PONDING OF WATER ON ROADWAYS AND IN URBAN AND LOW LYING AREAS MAY STILL OCCUR IN A FEW LOCATIONS...AND THIS WILL CONTINUE TO BE HIGHLIGHTED IN THE HWO STATEMENT. THIS RAINFALL WILL BE HELPING ACROSS THESE SOUTHERN AND EASTER AREAS...AS THE ANNUAL DEPARTURE FROM NORMAL FOR POUGHKEEPSIE NY STANDS AT -7.62 INCHES AND IS PITTSFIELD MA -4.18 INCHES. OVERNIGHT LOWS WILL MAINLY BE IN THE 60S...ALONG WITH THE MUGGY AND CLOUDY CONDITIONS. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/... THE REMNANTS OF BILL ARE EXPECTED TO TRACK TO ACROSS THE NEW YORK METRO AREA AND LONG ISLAND AND WILL CONTINUE TO IMPACTS MAINLY THE AREAS TO THE SOUTH AND EAST OF THE CAPITAL DISTRICT THROUGH THE MORNING INTO THE EARLY AFTERNOON HOURS. A SHORT WAVE TROUGH AND LOW PRESSURE SYSTEM MOVING THROUGH THE FAST ZONAL FLOW WILL BE ON THE APPROACH FOR SUNDAY. THE SYSTEM`S WARM FRONT IS EXPECTED TO LIFT ACROSS THE REGION SUNDAY PLACING US IN THE WARM SECTOR. THE AMOUNT OF INSTABILITY IS THE BIG QUESTION. FLOW WILL BE UNIDIRECTIONAL WITH SHEAR INCREASING AS THE AFTERNOON PROGRESSES INTO THE EVENING HOURS. IF THERE IS ENOUGH INSTABILITY TO WORK MULTICELLS CLUSTERS SHOULD FORM. HOWEVER GUIDANCE IS NOT IN AGREEMENT ABOUT HOW STEEP THE LAPSE RATES SHOULD GET. THE STORM PREDICTION CENTER HAS UPGRADED THE SEVERE WEATHER RISK TO SLIGHT FOR MUCH OF EAST CENTRAL NEW YORK...FOR AREAS TO THE NORTH AND WEST OF THE CAPITAL DISTRICT...WITH THE REST OF THE FORECAST AREA UNDER A MARGINAL RISK. HAVE ENHANCED WORDING IN THE FORECAST FOR GUSTY WINDS...SMALL HAIL AND HEAVY RAINFALL ADDRESSING THE THREAT. CHANCES FOR STORMS WILL DECREASE OVERNIGHT SUNDAY INTO MONDAY AS THE SHORT WAVE MOVES OFF TO OUR EAST. SOME RIDGING WILL BRIEFLY BUILD IN BETWEEN SHORT WAVES RESULTING IN MAINLY FAIR WEATHER WITH SEASONABLE TEMPERATURES MONDAY. && .LONG TERM /TUESDAY THROUGH SATURDAY/... THIS WILL BE A PREDOMINANTLY WET PERIOD WITH MAINLY SEASONABLE TEMPERATURES. THE ONLY DRY PERIOD IS EXPECTED TO RUN FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. THERE WILL BE PERIODS OF SUNSHINE... BUT ASIDE FROM TUESDAY...INSTABILITY AND MOISTURE WILL BE LIMITED...SO THE MENTION IS FOR JUST SHOWERS. HIGH TEMPERATURES WILL START OFF TUESDAY FROM AROUND 70 DEGREES IN THE WESTERN ADIRONDACKS...TO THE UPPER 80S IN THE LOWER MID HUDSON VALLEY...BUT WILL GRADUALLY COOL DOWN...TO HIGHS RANGING FROM THE MID 60S TO MID 70S BY FRIDAY. SATURDAY WILL AVERAGE ONLY SLIGHTLY WARMER. TUESDAY NIGHT WILL BE MILDEST...WITH LOWS FROM THE MID 50S TO LOWER 60S. BY FRIDAY NIGHT...LOWS WILL RANGE FROM AROUND 50 DEGREES IN THE NORTHERN HIGH PEAKS...TO THE UPPER 50S IN THE MID HUDSON VALLEY. NORMAL HIGHS AND LOWS FOR ALBANY DURING THIS PERIOD ARE LOWER 80S AND AROUND 59 DEGREES...RESPECTIVELY. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... FLYING CONDITIONS HAVE LOWERED DOWN TO MVFR CONDITIONS FOR CIGS FOR ALL SITES DUE TO ABUNDANT LOW LEVEL MOISTURE CAUSING PLENTY OF LOW STRATUS TO FORM. OVER THE NEXT FEW HOURS...RAIN SHOWERS WILL SPREAD ACROSS THE REGION FROM THE WEST. THIS WILL DROP VSBYS DOWN TO MVFR LEVELS AS WELL...AND EVENTUALLY IFR CONDITIONS FOR BOTH VSBYS/CIGS BY AROUND MIDNIGHT OR SO. THIS WILL CONTINUE THROUGH THE REMAINDER OF THE OVERNIGHT HOURS...WITH LIGHT TO CALM WINDS. SHOWERS WILL TAPER OFF BY AROUND 6-9 AM OVER THE REGION. IFR CONDITIONS SHOULD END ONCE THE RAIN STOPS...BUT IT MAY TAKE UNTIL THE MID TO LATE MORNING FOR FLYING CONDITIONS TO RETURN TO ABOVE MVFR LEVELS. DURING THE MID TO LATE AFTN HOURS...THERE MAY BE SOME ADDITIONAL SHOWERS OR T-STORMS AROUND...BUT THESE WILL BE RATHER SCT IN NATURE. SOUTHERLY WINDS WILL EVENTUALLY BECOME WESTERLY AROUND 10 KTS OR SO. OUTLOOK... SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. LIKELY SHRA...TSRA. MONDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. MONDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. TUESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. WEDNESDAY: NO OPERATIONAL IMPACT. NO SIG WX. WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. THURSDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. && .FIRE WEATHER... THE REMNANTS OF TROPICAL STORM BILL WILL IMPACT THE REGION TONIGHT INTO SUNDAY BRINGING A MODERATE TO HEAVY RAINFALL TO AREAS TO THE SOUTH AND EAST OF THE CAPITAL DISTRICT. A LOW PRESSURE SYSTEM WILL APPROACH THE REGION TONIGHT AND MOVE ACROSS THE AREA SUNDAY AND SUNDAY NIGHT TRIGGERING SHOWERS AND THUNDERSTORMS MAINLY DURING THE AFTERNOON INTO THE EVENING HOURS. CONDITIONS DRY OUT FOR MONDAY...HOWEVER MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED TUESDAY. && .HYDROLOGY... PWATS WILL BE IN THE RISE AND ARE EXPECTED TO INCREASE TO 1 1/2+ INCHES ACROSS THE FORECAST AREA WITH AROUND 2 INCHES ACROSS THE SOUTHERN MOST PORTION AS THE REMNANTS OF BILL MOVE ACROSS THE MID ATLANTIC REGION TOWARD THE NEW YORK METROPOLITAN AREA. THE GUIDANCE HAS TRENDED A BIT NORTHWARD WITH THE HEAVIER QPF. THE GFS IS THE MOST AGGRESSIVE HOWEVER IT APPEARS TO BE HAVING CONVECTIVE FEEDBACK ISSUES AND CAN BE TRUSTED. A MODERATE TO HEAVY RAINFALL IS EXPECTED TO THE SOUTH AND EAST OF THE CAPITAL DISTRICT AS THE HIGHER PWATS ARRIVE. NO FLOOD WATCH HAS BEEN ISSUED. THE SOUTHEASTERN PORTION OF THE FORECAST UNDER THE SEVERE DROUGHT CATEGORY ON THE U.S. DROUGHT MONITOR. THE ANNUAL DEPARTURE FROM NORMAL FOR POUGHKEEPSIE NY STANDS AT -7.62 INCHES AND IS PITTSFIELD MA -4.18 INCHES. SOME URBAN AND POOR DRAINING FLOODING IS POSSIBLE. PWATS WILL DECREASE SOME SUNDAY AS THE REMNANTS OF BILL MOVE AWAY FROM THE REGION. HOWEVER A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE AREA SUNDAY TRIGGERING SHOWERS AND THUNDERSTORMS. THE FOCUS FOR THIS ACTIVITY WILL BE MAINLY TO THE NORTH AND WEST OF THE CAPITAL DISTRICT SUNDAY AFTERNOON INTO THE EVENING. LOCALLY HEAVY RAINFALL WILL BE POSSIBLE WITH SOME THUNDERSTORMS. CONDITIONS DRY OUT FOR MONDAY...HOWEVER MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED TUESDAY. 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...IAA NEAR TERM...IAA SHORT TERM...IAA/FRUGIS LONG TERM...ELH AVIATION...FRUGIS FIRE WEATHER...IAA HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1005 AM EDT FRI JUN 19 2015 .SYNOPSIS... A COLD FRONT WILL MOVE SOUTH ACROSS THE REGION TODAY AND MAY TRIGGER AN AFTERNOON SHOWER OR THUNDERSTORM ACROSS CT...RI AND SOUTH OF THE MASS PIKE IN MASSACHUSETTS. HIGH PRESSURE BRINGS DRY AND COOLER WEATHER TONIGHT AND SATURDAY. A COLD FRONT SWEEPING FROM THE N AND THE REMNANTS OF ONCE TROPICAL STORM BILL MOVING IN FROM THE SOUTH WILL MAKE FOR A WET SUNDAY. ANOTHER ROUND OF WET- WEATHER IS POSSIBLE MONDAY AND TUESDAY PRIOR TO COOLER AND DRY CONDITIONS WEDNESDAY AND THURSDAY. WARMER AND WET CONDITIONS ARE FORECAST TO RETURN TO THE AREA BY THE END OF THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... 10 AM UPDATE... PREVIOUS FORECAST AND DISCUSSION SPOT ON. THUS ONLY MINOR TWEAKS TO CLOUD COVER FORECAST BASED ON BREAKS IN THE OVERCAST PER LATEST SATELLITE IMAGERY. EXPECTING CLOUDS TO ERODE AS MID LEVEL SHORT WAVE TROUGH ENTERING MAINE LATE THIS MORNING MOVES INTO THE MARITIMES THIS AFTERNOON. THIS WILL SWITCH MID LEVEL FLOW OVER NEW ENGLAND FROM WEAKLY CYCLONIC TO MORE ZONAL...PROVIDING LESS LIFT TO SUPPORT CLOUD COVER. THUS EXPECTING INCREASING SUNSHINE AS THE DAY PROGRESSES. MUCH OF THE DAY WILL BE DRY AND WARM WITH TEMPS CLIMBING INTO THE LOW AND MID 80S AWAY FROM THE SHORELINE WHERE A SEABREEZE IS POSSIBLE. A LOW RISK FOR ISOLATED TO WIDELY SCATTERED SHOWERS WITH EMBEDDED THUNDER POSSIBLE...ALONG AND AHEAD OF COLD FRONT. HOWEVER AS MENTIONED ABOVE FORCING FOR ASCENT IS WEAK. IN ADDITION WINDS ALOFT AT 925 MB AND 850 MB ARE FROM THE WEST. SO AS SOLAR HEATING DEEPENS BLYR AND WINDS MIX DOWN FROM ALOFT...SURFACE WINDS WILL TREND TO THE WEST EVEN AHEAD OF THE COLD FRONT. THIS WILL LIMIT SURFACE CONVERGENCE. HOWEVER IF A SEABREEZE BOUNDARY CAN PENETRATEINTO THE COASTAL PLAIN THIS COULD SERVE AS A FOCUS FOR SHOWERS AND/OR A T-STORM. OTHER LIMITING FACTOR AS PREVIOUS FORECASTER NOTED IS LACK OF INSTABILITY. MUCH OF THE GUIDANCE IS ONLY GENERATING 400-800J/KG OF CAPE ALONG WITH WEAK MID LEVEL LAPSE RATES. THIS WILL LIMIT UPDRAFT POTENTIAL. SO DESPITE MODEST TO STRONG WINDS ALOFT PROVIDING GOOD DEEP LAYER SHEAR...THE LACK OF INSTABILITY AND SYNOPTIC SCALE FORCING WILL LIMIT AREAL COVERAGE OF ANY SHOWERS TO ISOLATED OR WIDELY SCATTERED AND CONFINED TO CT/RI AND SOUTH OF THE MASS PIKE IN MASSACHUSETTS. THEREFORE MUCH OF THE REGION REMAINS DRY TODAY. ONLY CONCERN WILL BE AT SOUTH COASTAL BEACHES FOR THE LOW THREAT OF LIGHTNING. OTHERWISE A VERY NICE DAY BY LATE JUNE STANDARDS. PREVIOUS DISCUSSION... THE COLD FRONT WILL MOVE S ACROSS SNE THIS MORNING. AS THE FRONT PUSHES S CLOUDS WILL GIVE WAY TO PT-MOSUNNY SKIES FROM LATE MORNING THROUGH THE AFTERNOON WITH CLOUDS PERSISTING THE LONGEST ALONG THE S COAST. COLD FRONT APPEARS TO GET HUNG UP NEAR THE SOUTH COAST 18-21Z BEFORE MOVING S OF NEW ENG BY 00Z. MODELS DO GENERATE MARGINAL SFC INSTABILITY NEAR THE FRONT WITH SBCAPES AROUND 500 J/KG WITHIN LOW LEVEL THETA-E RIDGE AXIS SO POTENTIAL EXISTS FOR A FEW SHOWERS OR TSTM THIS AFTERNOON...MAINLY FOCUSED ACROSS RI AND SE MA. TIMING OF DRIER AIR AND FALLING DEWPOINTS INTO THE 50S WILL BE CRITICAL TO THE INSTABILITY AND POTENTIAL TSTM DEVELOPMENT. IF THE DRIER AIR IS DELAYED AND DEWPOINTS REMAIN IN THE 60S INTO THE AFTERNOON THERE WILL BE A GREATER CHANCE OF CONVECTION BUT IF THESE LOWER DEWPOINTS MOVE IN QUICKER THIS WILL LIKELY PRECLUDE TSTM DEVELOPMENT. MODELS ALL GENERATE SOME CONVECTIVE PRECIP IN THE COASTAL PLAIN THIS AFTERNOON AND HRRR IS TARGETING RI AND SE MA SO WE HAVE CHC POPS FOCUSED ACROSS NE CT...RI AND SE MA. DEEP LAYER SHEAR IS QUITE IMPRESSIVE AROUND 40-50 KT SO ANY CONVECTION WILL HAVE TO BE MONITORED CLOSELY. CANT RULE OUT A STRONG TSTM BUT THINK MARGINAL INSTABILITY AND WEAK MID LEVEL LAPSE RATES WILL LIMIT POTENTIAL FOR STRONG STORMS. 850 MB TEMPS 12-14C AND WITH DEVELOPING SUNSHINE AND NW WINDS IT WILL BE A WARM DAY WITH HIGHS REACHING LOW TO MID 80S...EXCEPT 70S ALONG THE COAST AND OVER HIGHER ELEVATIONS IN WESTERN AND N MA. && .SHORT TERM /SATURDAY/... TONIGHT... A LINGERING SHOWER IS POSSIBLE EARLY EVENING ALONG THE S COAST WITH THE FRONT...OTHERWISE COOLER AND DRIER POST-FRONTAL AIRMASS OVERSPREADS THE REGION AS HIGH PRES BUILDS IN. CLEARING SKIES EXPECTED ACROSS NORTHERN ZONES BUT CLOUDS MAY LINGER DURING THE NIGHT ALONG THE S COAST WHERE SOME PATCHY FOG POSSIBLE. MINS MOSTLY IN THE 50S BUT SOME 40S POSSIBLE IN NORTH CENTRAL AND W MA. SATURDAY... HIGH PRES IN CONTROL AS IT MOVES E OF NEW ENG. EXPECT INCREASING AFTERNOON CLOUDS...ESPECIALLY W NEW ENG. NAM APPEARS TOO AGGRESSIVE WITH RETUNING MOISTURE AND SHOWERS SO THIS WAS DISCOUNTED AS HIGH PRES MAINTAINS DRIER AIR WITH HIGHER THETA-E AIR REMAINING TO THE WEST. COOLER TEMPS IN THE 70S WITH SEABREEZES LIKELY HOLDING TEMPS NEAR 70 ALONG THE IMMEDIATE COAST. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... HIGHLIGHTS... - STILL LOOKING WET FOR SUNDAY WITH THE REMNANTS OF TS BILL - SOME UNCERTAINTY ON EXACT OUTCOMES - WET-WEATHER IS POSSIBLE MONDAY AND TUESDAY - UNSEASONABLY COOL AND DRY WEDNESDAY AND THURSDAY - A RETURN OF WARMER-WET CONDITIONS BY THE END OF THE WEEK DISCUSSION... A FORECAST THAT CONTINUES TO WOBBLE WITH RESPECT TO TWO WEATHER DISTURBANCES SATURDAY NIGHT INTO MONDAY MORNING: 1. REMNANTS OF TS BILL AND 2. STRETCHED PACIFIC-ORIGIN ENERGY THROUGH THE QUASI-ZONAL FLOW. OF CERTAINTY REMNANTS OF TS BILL ARE ASSOCIATED WITH HIGH THETA-E AIR / +2-INCH PWATS AND MARGINAL INSTABILITY FOCUSED ALONG THE NOSE OF A H925-85 LLJ ALONG ITS E-PERIPHERY OF CYCLONIC FLOW. IT IS WITHIN THE LOW- TO MID-LEVEL CONVERGENT NOSE THERE IS A EXPECTATION OF A GOOD SLUG OF RAIN WITH EMBEDDED HEAVIER SHOWERS AND POSSIBLE THUNDERSTORMS WITHIN A MOIST-ADIABATIC PROFILE WITH HIGH FREEZING- LEVEL HEIGHTS. SUCH ANTICIPATED OUTCOMES COULD YIELD THE POSSIBILITY OF NUISANCE/URBAN/POOR-DRAINAGE FLOODING ALBEIT NOT AS CATASTROPHIC AS WHAT HAS BEEN WITNESSED UPSTREAM ACROSS TX / OK AS THE FLOW IS PROGRESSIVE AND REMNANTS ARE BEING SWEPT AHEAD OF THE AFOREMENTIONED DISTURBANCE THROUGH THE ZONAL-FLOW REGIME. BUT UNCERTAIN IS THE EXACT TRACK OF THE REMNANTS WHICH CONTINUE TO WOBBLE AND HOW IT INTERACTS WITH THE NEIGHBORING N-STREAM IMPULSE. WHILE THE TRACK HAS WOBBLED WITHIN THE LATEST FORECAST RUNS THERE IS ALSO THE QUESTION AS TO WHETHER THE LOW- TO MID-LEVEL CONVERGENCE CAN CONNECT WITH THE RRQ OF THE NEIGHBORING UPPER-LEVEL-JET N. THERE DOES SEEM TO BE SOME LEVEL OF DIFFLUENCE TO SUPPORT DEEP-LAYER LIFT AND UPSLOPING-OVERRUNNING MOISTURE. THE TIMING MAYBE PERHAPS OFF SUCH THAT TROPICAL REMNANTS OF BILL MAY BE LIMITED IN THEIR REACH N. PERHAPS NOT. THIS IN ADDITION THAT BETWEEN TWO AREAS OF ASCENT THERE HAS TO BE AN AREA OF DESCENT/SINKING AIR. THERE HAS BEEN SOMEWHAT A CONSISTENT SIGNAL OF SOMEWHERE ACROSS THE NE-CONUS OF LITTLE IF ANY IMPACT BETWEEN THE UNPHASED DISTURBANCES. SOME UNCERTAINTIES TO PONDER...BUT NEVERTHELESS WILL KEEP WITH A WET FORECAST FOR SUNDAY AS THE REMNANTS OF TS BILL SLIDE S AND A COLD FRONT SWEEPS THROUGH FROM THE N AND W TOWARDS MONDAY MORNING. WILL MAINTAIN HIGHER POPS ALONG THE S-HALF OF S NEW ENGLAND. MAIN THREAT IS HEAVY RAIN WITH LESSER CHANCES OF THUNDER. BUT THIS COULD BE A SWING AND A MISS PER THE 19.0Z GFS AND ECMWF. THEREAFTER...NOT LOOKING SUMMER-LIKE. MID-LEVEL ENERGY THROUGH THE ZONAL-FLOW REGIME IS SHUNTED S GRADUALLY BY A POLAR-ORIGIN WAVE OUT OF THE HUDSON BAY REGION SWEEPING +8-10C H85 AIR ACROSS THE REGION. SO AN INITIAL IMPULSE OF WET-WEATHER ASSOCIATED WITH A WEAK-SYNOPTIC LOW IS ANTICIPATED MONDAY NIGHT. WILL GO WITH CHANCE POPS AND JUST SHOWERS. COULD SEE RENEWED ACTIVITY TUESDAY WITH THE ENVIRONMENT DESTABILIZING MAINLY ACROSS THE N AND W INTERIOR PRIOR TO A STRONG COLD FRONT DIGGING S PUSHING THE BETTER MOIST-CONVERGENT FLOW REGIME W TO E ACROSS THE MID-ATLANTIC TEMPERATURES. LOOKING AT BELOW-NORMAL TEMPERATURES AND DRY CONDITIONS WEDNESDAY - THURSDAY. IN THE END COULD PERHAPS SEE A CHILLY MONTH OF JUNE OF WHICH TEMPS PRESENTLY ARE AVERAGING 3 DEGREES BELOW-NORMAL THROUGH THE 18TH. AS THE POLAR-WAVE RETREATS BACK N TOWARDS THE END OF THE WEEK WILL SEE THE RETURN OF WARMER AIR AND AN ACTIVE WEATHER PATTERN PER A CONSENSUS OF FORECAST GUIDANCE. && .AVIATION /14Z FRIDAY THROUGH TUESDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH SATURDAY/... 14Z UPDATE...NOT MUCH CHANGE TO 12Z TAFS. ANY ISOLATED SHOWER/T-STORM WILL BE CONFINED TO CT/RI AND SOUTH OF THE MASS PIKE IN MASSACHUSETTS THIS AFTERNOON. MOST TERMINALS REMAIN DRY. EARLIER DISCUSSION BELOW. ================================================================== TODAY...MODERATE CONFIDENCE. EARLY IFR/MVFR ERODE AND IMPROVE TO VFR BY 15Z OR SO. THEN HAVE TO WATCH POTENTIAL FOR RENEWED SHRA/TSRA DEVELOPMENT MAINLY FOCUSED OVER RI AND SE MA AFTER 18Z. CONFIDENCE WITH TSRA IS LOW. TONIGHT...HIGH CONFIDENCE. A LINGERING SHRA POSSIBLE EARLY ALONG THE S COAST WITH THE FRONT...OTHERWISE VFR BUT PATCHY FOG POSSIBLE NEAR THE S COAST. SATURDAY...MODERATE CONFIDENCE. VFR CIGS. KBOS TERMINAL...MODERATE CONFIDENCE WITH RESPECT TO TIMING OF IMPROVING CONDITIONS TO VFR LATER THIS MORNING. A BRIEF SHOWER POSSIBLE THROUGH THIS MORNING. A WEAK SEABREEZE IS POSSIBLE THIS AFTERNOON BUT CONFIDENCE IS MODERATE. KBDL TERMINAL...MODERATE CONFIDENCE WITH RESPECT TO TIMING OF IMPROVING CONDITIONS TO VFR LATER THIS MORNING. A BRIEF SHOWER POSSIBLE THIS MORNING. OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY... SATURDAY NIGHT INTO MONDAY MORNING...MODERATE CONFIDENCE. MVFR / IFR ASSOC REMNANTS OF TS BILL. WIDESPREAD SHRA. POSSIBLE +RA ALONG THE S-COAST. POTENTIAL VSBY IMPACTS. S-WINDS WITH GUSTS UP TO 20 KTS ASSOC WITH TS BILL BACKING NW WITH A COLD FRONTAL PASSAGE PUSHING REMNANTS OUT TO SEA. MONDAY INTO TUESDAY NIGHT...MODERATE CONFIDENCE. PERIODS OF -SHRA. LOW-END VFR. W/NW-WINDS. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH SATURDAY/...HIGH CONFIDENCE. 7 AM UPDATE...NO MAJOR CHANGES TO THE FORECAST. TODAY...SW WINDS BECOMING LIGHT THEN LOCALLY EAST ACROSS E MA WATERS AS WEAK SEABREEZES DEVELOP. WINDS REMAINING SW OVER S COASTAL WATERS. A FEW SHOWERS POSSIBLE IN THE MORNING. TONIGHT...LIGHT NE WINDS BEHIND THE FRONT. ANY EVENING SHOWERS FOCUSED IN THE RI WATERS TO MVY/ACK AND SOUTH OF NEW ENGLAND WATERS. SATURDAY...WINDS TURNING SE WITH A FEW GUSTS TO 20 KT DEVELOPING. SEAS REMAINING BELOW SCA THRESHOLDS. OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY SATURDAY NIGHT INTO MONDAY MORNING...MODERATE CONFIDENCE. REMNANTS OF TS BILL. WIDESPREAD RAIN WITH EMBEDDED HEAVIER SHOWERS ESP OVER THE S-WATERS. ANTICIPATING VISIBILITY IMPACTS. POSSIBLE FOG. S-WINDS WITH GUSTS UP TO 20 KTS ASSOC WITH TS BILL BACKING NW WITH A COLD FRONTAL PASSAGE PUSHING REMNANTS OUT TO SEA. SEAS BUILDING IN EXCESS OF 5-FEET ON THE S/SE-WATERS. MONDAY INTO TUESDAY NIGHT...MODERATE CONFIDENCE. LIGHTER W/NW-WINDS. SEAS FALLING BELOW 5-FEET. PERIODS OF SHOWERS. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...KJC/SIPPRELL NEAR TERM...KJC/NOCERA/SIPPRELL SHORT TERM...KJC LONG TERM...SIPPRELL AVIATION...KJC/NOCERA/SIPPRELL MARINE...KJC/SIPPRELL
AREA FORECAST DISCUSSION
NWS TAUNTON MA
702 AM EDT FRI JUN 19 2015 .SYNOPSIS... A COLD FRONT WILL MOVE SOUTH ACROSS THE REGION TODAY AND MAY TRIGGER AN AFTERNOON THUNDERSTORM ACROSS RI AND SOUTHEAST MA. HIGH PRESSURE BRINGS DRY AND COOLER WEATHER TONIGHT AND SATURDAY. A COLD FRONT SWEEPING FROM THE N AND THE REMNANTS OF TS BILL MOVING IN FROM THE S WILL MAKE FOR A WET SUNDAY. ANOTHER ROUND OF WET-WEATHER IS POSSIBLE MONDAY AND TUESDAY PRIOR TO COOLER AND DRY CONDITIONS WEDNESDAY AND THURSDAY. WARMER AND WET CONDITIONS ARE FORECAST TO RETURN TO THE AREA BY THE END OF THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... 7 AM UPDATE... WIDELY SCATTERED SHOWERS CONTINUE TO PERSIST ACROSS THE AREA ALBEIT DIMINISH OVER MOST LOCATIONS. THERE REMAINS AN INSTABILITY BURST ACROSS THE AREA AS THE PREVIOUS FORECASTER MENTION ALONG AND AHEAD OF THE SURFACE COLD FRONT PRESENTLY SLOWLY TOWARDS THE S AND E THOUGH IS VERY MARGINAL WITH ELEVATED CAPES BARELY EXCEEDING 100 J/KG. HAVE REMOVED THE MENTION OF THUNDER FROM THE MORNING FORECAST. FEEL THE PREVIOUS DISCUSSION BELOW STILL APPLIES WITH RESPECT TO EXPECTATIONS THIS AFTERNOON... PREVIOUS DISCUSSION... THE COLD FRONT WILL MOVE S ACROSS SNE THIS MORNING. AS THE FRONT PUSHES S CLOUDS WILL GIVE WAY TO PT-MOSUNNY SKIES FROM LATE MORNING THROUGH THE AFTERNOON WITH CLOUDS PERSISTING THE LONGEST ALONG THE S COAST. COLD FRONT APPEARS TO GET HUNG UP NEAR THE SOUTH COAST 18-21Z BEFORE MOVING S OF NEW ENG BY 00Z. MODELS DO GENERATE MARGINAL SFC INSTABILITY NEAR THE FRONT WITH SBCAPES AROUND 500 J/KG WITHIN LOW LEVEL THETA-E RIDGE AXIS SO POTENTIAL EXISTS FOR A FEW SHOWERS OR TSTM THIS AFTERNOON...MAINLY FOCUSED ACROSS RI AND SE MA. TIMING OF DRIER AIR AND FALLING DEWPOINTS INTO THE 50S WILL BE CRITICAL TO THE INSTABILITY AND POTENTIAL TSTM DEVELOPMENT. IF THE DRIER AIR IS DELAYED AND DEWPOINTS REMAIN IN THE 60S INTO THE AFTERNOON THERE WILL BE A GREATER CHANCE OF CONVECTION BUT IF THESE LOWER DEWPOINTS MOVE IN QUICKER THIS WILL LIKELY PRECLUDE TSTM DEVELOPMENT. MODELS ALL GENERATE SOME CONVECTIVE PRECIP IN THE COASTAL PLAIN THIS AFTERNOON AND HRRR IS TARGETING RI AND SE MA SO WE HAVE CHC POPS FOCUSED ACROSS NE CT...RI AND SE MA. DEEP LAYER SHEAR IS QUITE IMPRESSIVE AROUND 40-50 KT SO ANY CONVECTION WILL HAVE TO BE MONITORED CLOSELY. CANT RULE OUT A STRONG TSTM BUT THINK MARGINAL INSTABILITY AND WEAK MID LEVEL LAPSE RATES WILL LIMIT POTENTIAL FOR STRONG STORMS. 850 MB TEMPS 12-14C AND WITH DEVELOPING SUNSHINE AND NW WINDS IT WILL BE A WARM DAY WITH HIGHS REACHING LOW TO MID 80S...EXCEPT 70S ALONG THE COAST AND OVER HIGHER ELEVATIONS IN WESTERN AND N MA. && .SHORT TERM /SATURDAY/... TONIGHT... A LINGERING SHOWER IS POSSIBLE EARLY EVENING ALONG THE S COAST WITH THE FRONT...OTHERWISE COOLER AND DRIER POST-FRONTAL AIRMASS OVERSPREADS THE REGION AS HIGH PRES BUILDS IN. CLEARING SKIES EXPECTED ACROSS NORTHERN ZONES BUT CLOUDS MAY LINGER DURING THE NIGHT ALONG THE S COAST WHERE SOME PATCHY FOG POSSIBLE. MINS MOSTLY IN THE 50S BUT SOME 40S POSSIBLE IN NORTH CENTRAL AND W MA. SATURDAY... HIGH PRES IN CONTROL AS IT MOVES E OF NEW ENG. EXPECT INCREASING AFTERNOON CLOUDS...ESPECIALLY W NEW ENG. NAM APPEARS TOO AGGRESSIVE WITH RETUNING MOISTURE AND SHOWERS SO THIS WAS DISCOUNTED AS HIGH PRES MAINTAINS DRIER AIR WITH HIGHER THETA-E AIR REMAINING TO THE WEST. COOLER TEMPS IN THE 70S WITH SEABREEZES LIKELY HOLDING TEMPS NEAR 70 ALONG THE IMMEDIATE COAST. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... HIGHLIGHTS... - STILL LOOKING WET FOR SUNDAY WITH THE REMNANTS OF TS BILL - SOME UNCERTAINTY ON EXACT OUTCOMES - WET-WEATHER IS POSSIBLE MONDAY AND TUESDAY - UNSEASONABLY COOL AND DRY WEDNESDAY AND THURSDAY - A RETURN OF WARMER-WET CONDITIONS BY THE END OF THE WEEK DISCUSSION... A FORECAST THAT CONTINUES TO WOBBLE WITH RESPECT TO TWO WEATHER DISTURBANCES SATURDAY NIGHT INTO MONDAY MORNING: 1. REMNANTS OF TS BILL AND 2. STRETCHED PACIFIC-ORIGIN ENERGY THROUGH THE QUASI-ZONAL FLOW. OF CERTAINTY REMNANTS OF TS BILL ARE ASSOCIATED WITH HIGH THETA-E AIR / +2-INCH PWATS AND MARGINAL INSTABILITY FOCUSED ALONG THE NOSE OF A H925-85 LLJ ALONG ITS E-PERIPHERY OF CYCLONIC FLOW. IT IS WITHIN THE LOW- TO MID-LEVEL CONVERGENT NOSE THERE IS A EXPECTATION OF A GOOD SLUG OF RAIN WITH EMBEDDED HEAVIER SHOWERS AND POSSIBLE THUNDERSTORMS WITHIN A MOIST-ADIABATIC PROFILE WITH HIGH FREEZING- LEVEL HEIGHTS. SUCH ANTICIPATED OUTCOMES COULD YIELD THE POSSIBILITY OF NUISANCE/URBAN/POOR-DRAINAGE FLOODING ALBEIT NOT AS CATASTROPHIC AS WHAT HAS BEEN WITNESSED UPSTREAM ACROSS TX / OK AS THE FLOW IS PROGRESSIVE AND REMNANTS ARE BEING SWEPT AHEAD OF THE AFOREMENTIONED DISTURBANCE THROUGH THE ZONAL-FLOW REGIME. BUT UNCERTAIN IS THE EXACT TRACK OF THE REMNANTS WHICH CONTINUE TO WOBBLE AND HOW IT INTERACTS WITH THE NEIGHBORING N-STREAM IMPULSE. WHILE THE TRACK HAS WOBBLED WITHIN THE LATEST FORECAST RUNS THERE IS ALSO THE QUESTION AS TO WHETHER THE LOW- TO MID-LEVEL CONVERGENCE CAN CONNECT WITH THE RRQ OF THE NEIGHBORING UPPER-LEVEL-JET N. THERE DOES SEEM TO BE SOME LEVEL OF DIFFLUENCE TO SUPPORT DEEP-LAYER LIFT AND UPSLOPING-OVERRUNNING MOISTURE. THE TIMING MAYBE PERHAPS OFF SUCH THAT TROPICAL REMNANTS OF BILL MAY BE LIMITED IN THEIR REACH N. PERHAPS NOT. THIS IN ADDITION THAT BETWEEN TWO AREAS OF ASCENT THERE HAS TO BE AN AREA OF DESCENT/SINKING AIR. THERE HAS BEEN SOMEWHAT A CONSISTENT SIGNAL OF SOMEWHERE ACROSS THE NE-CONUS OF LITTLE IF ANY IMPACT BETWEEN THE UNPHASED DISTURBANCES. SOME UNCERTAINTIES TO PONDER...BUT NEVERTHELESS WILL KEEP WITH A WET FORECAST FOR SUNDAY AS THE REMNANTS OF TS BILL SLIDE S AND A COLD FRONT SWEEPS THROUGH FROM THE N AND W TOWARDS MONDAY MORNING. WILL MAINTAIN HIGHER POPS ALONG THE S-HALF OF S NEW ENGLAND. MAIN THREAT IS HEAVY RAIN WITH LESSER CHANCES OF THUNDER. BUT THIS COULD BE A SWING AND A MISS PER THE 19.0Z GFS AND ECMWF. THEREAFTER...NOT LOOKING SUMMER-LIKE. MID-LEVEL ENERGY THROUGH THE ZONAL-FLOW REGIME IS SHUNTED S GRADUALLY BY A POLAR-ORIGIN WAVE OUT OF THE HUDSON BAY REGION SWEEPING +8-10C H85 AIR ACROSS THE REGION. SO AN INITIAL IMPULSE OF WET-WEATHER ASSOCIATED WITH A WEAK-SYNOPTIC LOW IS ANTICIPATED MONDAY NIGHT. WILL GO WITH CHANCE POPS AND JUST SHOWERS. COULD SEE RENEWED ACTIVITY TUESDAY WITH THE ENVIRONMENT DESTABILIZING MAINLY ACROSS THE N AND W INTERIOR PRIOR TO A STRONG COLD FRONT DIGGING S PUSHING THE BETTER MOIST-CONVERGENT FLOW REGIME W TO E ACROSS THE MID-ATLANTIC TEMPERATURES. LOOKING AT BELOW-NORMAL TEMPERATURES AND DRY CONDITIONS WEDNESDAY - THURSDAY. IN THE END COULD PERHAPS SEE A CHILLY MONTH OF JUNE OF WHICH TEMPS PRESENTLY ARE AVERAGING 3 DEGREES BELOW-NORMAL THROUGH THE 18TH. AS THE POLAR-WAVE RETREATS BACK N TOWARDS THE END OF THE WEEK WILL SEE THE RETURN OF WARMER AIR AND AN ACTIVE WEATHER PATTERN PER A CONSENSUS OF FORECAST GUIDANCE. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH SATURDAY/... 12Z UPDATE... TODAY...MODERATE CONFIDENCE. EARLY IFR/MVFR ERODE AND IMPROVE TO VFR BY 15Z OR SO. THEN HAVE TO WATCH POTENTIAL FOR RENEWED SHRA/TSRA DEVELOPMENT MAINLY FOCUSED OVER RI AND SE MA AFTER 18Z. CONFIDENCE WITH TSRA IS LOW. TONIGHT...HIGH CONFIDENCE. A LINGERING SHRA POSSIBLE EARLY ALONG THE S COAST WITH THE FRONT...OTHERWISE VFR BUT PATCHY FOG POSSIBLE NEAR THE S COAST. SATURDAY...MODERATE CONFIDENCE. VFR CIGS. KBOS TERMINAL...MODERATE CONFIDENCE WITH RESPECT TO TIMING OF IMPROVING CONDITIONS TO VFR LATER THIS MORNING. A BRIEF SHOWER POSSIBLE THROUGH THIS MORNING. A WEAK SEABREEZE IS POSSIBLE THIS AFTERNOON BUT CONFIDENCE IS MODERATE. KBDL TERMINAL...MODERATE CONFIDENCE WITH RESPECT TO TIMING OF IMPROVING CONDITIONS TO VFR LATER THIS MORNING. A BRIEF SHOWER POSSIBLE THIS MORNING. OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY... SATURDAY NIGHT INTO MONDAY MORNING...MODERATE CONFIDENCE. MVFR / IFR ASSOC REMNANTS OF TS BILL. WIDESPREAD SHRA. POSSIBLE +RA ALONG THE S-COAST. POTENTIAL VSBY IMPACTS. S-WINDS WITH GUSTS UP TO 20 KTS ASSOC WITH TS BILL BACKING NW WITH A COLD FRONTAL PASSAGE PUSHING REMNANTS OUT TO SEA. MONDAY INTO TUESDAY NIGHT...MODERATE CONFIDENCE. PERIODS OF -SHRA. LOW-END VFR. W/NW-WINDS. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH SATURDAY/...HIGH CONFIDENCE. 7 AM UPDATE...NO MAJOR CHANGES TO THE FORECAST. TODAY...SW WINDS BECOMING LIGHT THEN LOCALLY EAST ACROSS E MA WATERS AS WEAK SEABREEZES DEVELOP. WINDS REMAINING SW OVER S COASTAL WATERS. A FEW SHOWERS POSSIBLE IN THE MORNING. TONIGHT...LIGHT NE WINDS BEHIND THE FRONT. ANY EVENING SHOWERS FOCUSED IN THE RI WATERS TO MVY/ACK AND SOUTH OF NEW ENGLAND WATERS. SATURDAY...WINDS TURNING SE WITH A FEW GUSTS TO 20 KT DEVELOPING. SEAS REMAINING BELOW SCA THRESHOLDS. OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY SATURDAY NIGHT INTO MONDAY MORNING...MODERATE CONFIDENCE. REMNANTS OF TS BILL. WIDESPREAD RAIN WITH EMBEDDED HEAVIER SHOWERS ESP OVER THE S-WATERS. ANTICIPATING VISIBILITY IMPACTS. POSSIBLE FOG. S-WINDS WITH GUSTS UP TO 20 KTS ASSOC WITH TS BILL BACKING NW WITH A COLD FRONTAL PASSAGE PUSHING REMNANTS OUT TO SEA. SEAS BUILDING IN EXCESS OF 5-FEET ON THE S/SE-WATERS. MONDAY INTO TUESDAY NIGHT...MODERATE CONFIDENCE. LIGHTER W/NW-WINDS. SEAS FALLING BELOW 5-FEET. PERIODS OF SHOWERS. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...KJC/SIPPRELL NEAR TERM...KJC/SIPPRELL SHORT TERM...KJC LONG TERM...SIPPRELL AVIATION...KJC/SIPPRELL MARINE...KJC/SIPPRELL
AREA FORECAST DISCUSSION
NWS ALBANY NY
651 AM EDT FRI JUN 19 2015 .SYNOPSIS... A COLD FRONT WILL SLOWLY SLIDE SOUTH OF THE REGION TODAY AS HIGH PRESSURE BUILDS IN FROM THE GREAT LAKES REGION. COOLER AND DRIER WEATHER WILL CONTINUE INTO THE FIRST HALF OF THE WEEKEND...AS WET AND UNSETTLED WEATHER CONDITIONS RETURNS SATURDAY NIGHT INTO SUNDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 630 AM EDT...RADAR REVEALS VERY LITTLE AS SHOWERS CONTINUE TO DIMINISH IN BOTH COVERAGE AND INTENSITY. THE ARRIVAL OF THE 06Z GUIDANCE CONTINUES TO SUPPORT THE SLOWING TREND OF THE FRONTAL PROGRESSION AND HRRR REFLECTIVITY FORECASTS SUPPORT THE PREVIOUS NOTION OF KEEPING SLIGHT CHANCE OF SHOWERS FOR THE SOUTHERN PORTIONS OF THE CWFA. THIS UPDATE REFRESHES THE HOURLY TRENDS PER OBSERVATIONS. THE SOMEWHAT SLOWER EXIT OF THIS FRONT AS WE WILL NEED TO RETAIN SOME POPS THROUGH THE MORNING FOR LOCATIONS JUST TO THE SOUTH OF I90 THEN THROUGH THE I84 CORRIDOR INTO THE EARLY AFTERNOON HOURS. IN FACT...MESOSCALE LOW LEVEL CONVERGENCE INTO THE HUDSON VALLEY MAY BE ENOUGH FOR ADDITIONAL CLOUD COVER AND A PASSING SHOWER. TRENDS IN THE HRRR REFLECTIVITY FORECASTS ALSO SUGGEST THIS SLIGHT CHANCE POSSIBILITY ALONG WITH SHORT TERM ENSEMBLES. OTHERWISE...SURFACE HIGH WILL BE BUILDING ACROSS THE EASTERN GREAT LAKES REGION AND INTO THE ADIRONDACK STATE PARK THROUGH THE DAY AS H850 TEMPS SETTLE BACK INTO THE MID-UPR SINGLE DIGITS FOR THE DACKS/LAKE GEORGE SARATOGA REGION TO AROUND 10C ALONG AND SOUTH OF THE I90 CORRIDOR. THIS WOULD SUGGEST TEMPERATURES WILL AVERAGE INTO THE 60S ACROSS THE NORTH AND INTO THE HIGHER TERRAIN OF THE SOUTHERN GREENS TO AROUND 80F FOR THE MID HUDSON VALLEY AND SOUTHERN LITCHFIELD COUNTY CT. LOW LEVEL DRY ADVECTION WILL RESULT IN A DROP IN DEWPOINTS AS WE FALL FROM THE 60S THIS EARLY MORNING TO UPPER 40S ACROSS THE NORTH...50S FOR MOST THE REGION BUT HANGING AROUND 60F FOR THE MID HUDSON VALLEY AND NW CT WHERE THE AFOREMENTIONED SLIGHT CHANCE POPS WILL REMAIN. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/... TONIGHT...A CLEAR/MOSTLY CLEAR NIGHT IS EXPECTED ACROSS MOST OF THE REGION WITH DIMINISHING WINDS THAT BECOME LIGHT TO CALM...AS THE SFC HIGH MOVES OVERHEARD. THE EXCEPTION TO THIS WOULD BE FOR THE MID HUDSON VALLEY AND NW CT WHERE LOW LEVEL FLOW IS EXPECTED TO ONCE AGAIN BECOME SOUTHERLY WITH MOISTURE ADVECTING BACK NORTHWARD. AS THE CANADIAN AIR MASS SETTLES SOUTHWARD FOR MOST OF THE REGION...H850 TEMPS WILL BE IN THE +7C TO +10C RANGE. IDEAL RADIATIONAL COOLING CONDITIONS ACROSS THE NORTHERN 2/3RDS OF THE CWFA WILL ALLOW TEMPS TO FALL INTO THE U40S TO M50S FROM THE CAPITAL REGION/MOHAWK VALLEY SOUTH AND EAST...AND MAINLY 40-45F NORTH OF ALBANY WITH A FEW U30S OVER THE SRN DACKS. SATURDAY...THE LAST FULL DAY OF SPRING WILL BE A NICE START TO THE WEEKEND IS EXPECTED WITH THE SFC HIGH MOVING EAST OF NEW ENGLAND DURING THE AFTERNOON. HOWEVER...INCREASING MID AND HIGH CLOUDS FROM THE SOUTH AND WEST IN ADVANCE OF A WARM FRONT OVER THE OH VALLEY AND MID ATLANTIC STATES. THE REMNANT CIRCULATION FROM BILL WILL ALSO APPROACH THE OH RIVER VALLEY. A FEW SHOWERS MAY POP UP LATE IN THE DAY MAINLY TO THE WEST AND SOUTH OF ALBANY. OTHERWISE FAIR AND DRY CONDITIONS ARE EXPECTED FOR MOST OF THE AREA WITH HIGHS MAINLY IN THE LOW TO MID 70S IN THE LOWER ELEVATIONS...AND M60S TO U60S OVER THE MTNS. SATURDAY NIGHT INTO SUNDAY...WARM FRONT ADVANCES NORTHWARD WITH THICKENING CLOUD COVERAGE ALONG WITH INCREASING PROBABILITIES FOR SHOWERS AND SOME EMBEDDED THUNDERSTORMS AS PWATS CLIMB TO BETWEEN 1.50-2.00 INCHES ALONG WITH NEGATIVE SHOWALTER VALUES. MEANWHILE...REMNANTS OF BILL ARE PROGGED TO TRACK ALONG OR SOUTH OF I80 WITH THE NAM THE FURTHEST NORTH WITH ITS TRACK THROUGH SUNDAY. AS PER THE LATEST SWODY3...ALL OF OUR REGION IS WITHIN A MARGINAL RISK FOR SEVERE THUNDERSTORMS /5%/. A CLOSER EXAMINATION OF SURFACE BASED INSTABILITY...WITH DEWPOINTS EXPECTED TO BE WELL INTO THE 60S...SBCAPES CLIMB TO BETWEEN 1K-2K J/KG MAINLY ACROSS OUR EASTERN NY COUNTIES. HOWEVER...WITH PWATS EXPECTED TO BE 2-3 STANDARD DEVIATIONS ABOVE NORMAL AND MARGINAL SHEAR PROFILES OF 25-30KTS...SOME ORGANIZED CONVECTIVE ELEMENTS WITH WET MICROBUST POTENTIAL AND LOCALLY HEAVY RAINFALL. SUNDAY NIGHT...IN THE WAKE OF BILL...UPSTREAM SHORT WAVE AND WEAK SURFACE REFLECTION WILL TRANSVERSE THE REGION. THIS WILL KEEP THE THREAT FOR MORE SHOWERS AND EMBEDDED THUNDERSTORMS /ESPECIALLY DURING THE EVENING HOURS/. OVERALL COVERAGE DOES DIMINISH WITH THE COMBINATION OF THE LOSS WITH DAYTIME HEATING AND SOME SUBSIDENCE IN THE WAKE OF BILL. WE WILL LOWER POPS TO CHC-SCT ACROSS MOST OF THE REGION WITH SLIGHT CHANCE POPS FOR THE MID HUDSON VALLEY INTO NW CT. IT WILL BE RATHER WARM AND MUGGY WITH MAINLY 60S FOR BOTH TEMPS AND DEWPOINTS. && .LONG TERM /MONDAY THROUGH THURSDAY/... THE EXTENDED PERIOD STILL LOOKS RATHER ACTIVE AS A FAIRLY UNSEASONABLY STRONG UPPER LEVEL JET REMAINS PERCHED JUST TO THE NORTH OF A STRONG RIDGE ANCHORED OVER THE SOUTHEAST...AND MUCH COOLER AIR OVER EASTERN CANADA. A SERIES OF MCS AND PERHAPS A MORE SIGNIFICANT LOW PRESSURE WILL PROPAGATE UNDERNEATH THE JET (RIDGE ROLLERS). TIMING THOUGH CHALLENGING WAS SURPRISINGLY PRETTY CONSISTENT AMONGST THE 00Z GFS/ECMWF AND CANADIAN LONG RANGE METEOROLOGICAL MODELS. MONDAY ACTUALLY LOOKS DRY WITH A BUBBLE OF HIGH PRESSURE BUILDING IN FROM CANADA TO BRING A DRY WARM DAY TO OUR PARTS. THEN...ON TUESDAY ANOTHER WEAK DISTURBANCE MIGHT TRIGGER ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS. THE ECMWF WAS MOST ROBUST WITH THIS FEATURE AND WPC LEANED WITH THIS SOLUTION. THAT SYSTEM IS GONE BY WEDNESDAY...AND WEAK SURFACE HIGH MIGHT BE ENOUGH TO KEEP IT DRY. WEDNESDAY NIGHT A MCS IS FORECAST TO MOVE MAINLY SOUTH OF OUR REGION...BUT IT MIGHT CLIP MAINLY OUR SOUTHERN AREAS. FOR NOW WENT SLIGHT CHANCES EVERYWHERE WEDNESDAY NIGHT. THURSDAY STARTS OUT DRY BUT BY THURSDAY NIGHT INTO FRIDAY...ANOTHER LOW PRESSURE IS FORECAST TO TRAVERSE FROM THE OHIO VALLEY ACROSS OUR REGION. THE 00Z GFS IS SLIGHTLY STRONGER AND SLIGHTLY SLOWER WITH THIS SYSTEM. EITHER WAY...IT LOOKS LIKE YET ANOTHER SHOT OF SHOWERS OR PERHAPS EVEN A PERIOD OF STEADY RAIN MAINLY FOR FRIDAY. TEMPERATURES START OUT WARM FOR MONDAY WITH HIGHS IN THE 80S...LOCALLY MID 80S IN THE CAPITAL REGION...UPPER 80S SOUTH AND LOWER 80S WELL NORTH OF ALBANY. AFTER THAT...TEMPERATURES LOOK SLIGHTLY BELOW FOR THE REMAINDER OF THE EXTENDED PERIOD. THIS WILL TRANSLATE TO HIGHS IN THE 70S...TO NEAR 80 SOUTH...MOST DAYS WITH LOWS IN THE 50S TO NEAR 60. PRECIPITATION LOOK TO CONTINUE TO RUN ABOVE NORMAL DURING THE EXTENDED PERIOD. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... A COLD FRONT WAS STILL WORKING THROUGH THE REGION THIS MORNING. THIS FRONT CONTINUED TO BRING A FEW SHOWERS...AND MORE IMPORTANTLY...LOW IFR CLOUDS TO KPSF AND KPOU. THERE WAS A LITTLE IFR FOG AT KGFL WHICH SHOULD DISSIPATE BY 13Z. OTHERWISE MVFR AT KALB. THE LOW CLOUDS AND MOST SHOWERS SHOULD END BY 14Z AS CONDITIONS TRANSITION TO VFR. CIGS COULD PERSIST AT KPOU AWHILE LONGER AS THE COLD SLOWS WHILE PASSING THAT TAF SITE. WE HANDLED THE SHOWERS WITH VCSH IN THE TAFS. AFTER 14Z...LOOKING AT VFR CONDITIONS EVERYWHERE WITH GOOD VISIBILITIES. THE SURFACE WIND...WILL BECOME NORTHWEST TO NORTH AROUND 10KTS LATER THIS MORNING..GUSTING UP TO 18KTS AT KALB AND KPSF BY MIDDAY. BY THIS EVENING...EXPECT A CLEAR SKY UNRESTRICTED VISIBILITY AND LIGHT WIND. THERE MIGHT BE SOME PATCHY FOG FORMING OVERNIGHT. FOR NOW ASSIGNED 3SM BR (MVFR MIST) AT KGFL AND ONLY SHALLOW FOG (MIFG) AT THE OTHER TAF SITES...AFTER 08Z. OUTLOOK... SATURDAY: LOW OPERATIONAL IMPACT. SLIGHT CHC SHRA. SATURDAY NIGHT AND SUNDAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA. SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. MONDAY: NO OPERATIONAL IMPACT. NO SIG WX. MONDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...TSRA. TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. && .FIRE WEATHER... AS A COLD FRONT SLIDES ACROSS THE REGION FROM NORTH TO SOUTH...A BAND OF SHOWERS AND EMBEDDED THUNDERSTORMS WILL ACCOMPANY ITS PASSAGE. THIS FRONT MAY SLOW AS IT APPROACHES THE MID HUDSON VALLEY WHERE THE SLIGHT CHANCE FOR ADDITIONAL SHOWERS ALONG WITH SOME WEAK WIND CONVERGENCE INTO THE MID HUDSON VALLEY TO SUPPORT A SLIGHT CHANCE FOR SHOWERS. OTHERWISE...DRIER CONDITIONS WILL BE ADVECTING INTO THE MOST OF OUR CENTRAL AND NORTHERN AREAS WHERE MIN RH VALUES DROP TO BETWEEN 35 AND 45 PERCENT...WITH NEAR 50 PERCENT SOUTH OF I90. WINDS WILL BE SHIFTING TO A NORTHERLY DIRECTION THROUGH THE DAY WITH SPEEDS AROUND 10 MPH WITH SOME HIGHER GUSTS. DRIER WEATHER EXPECTED TONIGHT AS HIGH PRESSURE SLIDES ACROSS THE REGION. LIGHT AND VARIABLE TO CALM WINDS EXPECTED AS RH VALUES CLIMB TO BETWEEN 65 AND 85 PERCENT. MOISTURE RETURNS THIS WEEKEND WITH INCREASING CHANCE FOR SHOWERS AND THUNDERSTORMS. && .HYDROLOGY... AREA RIVERS AND STREAMS WILL LIKELY EXHIBIT AN INCREASE OF WITHIN BANK FLOWS THIS WEEKEND AS THE COMBINATION OF HIGHER MOISTURE CONTENT AND THE REMNANTS OF BILL PASSING TO THE SOUTH OF OUR LOCAL REGION. PWATS ARE EXPECTED TO CLIMB TO BETWEEN 1.50-2.00 INCHES THIS WEEKEND WHICH IS 2-3 STANDARD DEVIATIONS ABOVE NORMAL AND ANY CONVECTION MAY PRODUCE LOCALLY HEAVY RAINFALL. AT THE PRESENT TIME...QPF FROM THE VAST ARRAY OF GUIDANCE SUGGEST BASIN AVERAGES WOULD BE AROUND 1 INCH. 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...BGM NEAR TERM...BGM SHORT TERM...BGM/WASULA LONG TERM...HWJIV AVIATION...HWJIV FIRE WEATHER...BGM/WASULA HYDROLOGY...BGM/WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
631 AM EDT FRI JUN 19 2015 .SYNOPSIS... A COLD FRONT WILL SLOWLY SLIDE SOUTH OF THE REGION TODAY AS HIGH PRESSURE BUILDS IN FROM THE GREAT LAKES REGION. COOLER AND DRIER WEATHER WILL CONTINUE INTO THE FIRST HALF OF THE WEEKEND...AS WET AND UNSETTLED WEATHER CONDITIONS RETURNS SATURDAY NIGHT INTO SUNDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 630 AM EDT...RADAR REVEALS VERY LITTLE AS SHOWERS CONTINUE TO DIMINISH IN BOTH COVERAGE AND INTENSITY. THE ARRIVAL OF THE 06Z GUIDANCE CONTINUES TO SUPPORT THE SLOWING TREND OF THE FRONTAL PROGRESSION AND HRRR REFLECTIVITY FORECASTS SUPPORT THE PREVIOUS NOTION OF KEEPING SLIGHT CHANCE OF SHOWERS FOR THE SOUTHERN PORTIONS OF THE CWFA. THIS UPDATE REFRESHES THE HOURLY TRENDS PER OBSERVATIONS. THE SOMEWHAT SLOWER EXIT OF THIS FRONT AS WE WILL NEED TO RETAIN SOME POPS THROUGH THE MORNING FOR LOCATIONS JUST TO THE SOUTH OF I90 THEN THROUGH THE I84 CORRIDOR INTO THE EARLY AFTERNOON HOURS. IN FACT...MESOSCALE LOW LEVEL CONVERGENCE INTO THE HUDSON VALLEY MAY BE ENOUGH FOR ADDITIONAL CLOUD COVER AND A PASSING SHOWER. TRENDS IN THE HRRR REFLECTIVITY FORECASTS ALSO SUGGEST THIS SLIGHT CHANCE POSSIBILITY ALONG WITH SHORT TERM ENSEMBLES. OTHERWISE...SURFACE HIGH WILL BE BUILDING ACROSS THE EASTERN GREAT LAKES REGION AND INTO THE ADIRONDACK STATE PARK THROUGH THE DAY AS H850 TEMPS SETTLE BACK INTO THE MID-UPR SINGLE DIGITS FOR THE DACKS/LAKE GEORGE SARATOGA REGION TO AROUND 10C ALONG AND SOUTH OF THE I90 CORRIDOR. THIS WOULD SUGGEST TEMPERATURES WILL AVERAGE INTO THE 60S ACROSS THE NORTH AND INTO THE HIGHER TERRAIN OF THE SOUTHERN GREENS TO AROUND 80F FOR THE MID HUDSON VALLEY AND SOUTHERN LITCHFIELD COUNTY CT. LOW LEVEL DRY ADVECTION WILL RESULT IN A DROP IN DEWPOINTS AS WE FALL FROM THE 60S THIS EARLY MORNING TO UPPER 40S ACROSS THE NORTH...50S FOR MOST THE REGION BUT HANGING AROUND 60F FOR THE MID HUDSON VALLEY AND NW CT WHERE THE AFOREMENTIONED SLIGHT CHANCE POPS WILL REMAIN. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/... TONIGHT...A CLEAR/MOSTLY CLEAR NIGHT IS EXPECTED ACROSS MOST OF THE REGION WITH DIMINISHING WINDS THAT BECOME LIGHT TO CALM...AS THE SFC HIGH MOVES OVERHEARD. THE EXCEPTION TO THIS WOULD BE FOR THE MID HUDSON VALLEY AND NW CT WHERE LOW LEVEL FLOW IS EXPECTED TO ONCE AGAIN BECOME SOUTHERLY WITH MOISTURE ADVECTING BACK NORTHWARD. AS THE CANADIAN AIR MASS SETTLES SOUTHWARD FOR MOST OF THE REGION...H850 TEMPS WILL BE IN THE +7C TO +10C RANGE. IDEAL RADIATIONAL COOLING CONDITIONS ACROSS THE NORTHERN 2/3RDS OF THE CWFA WILL ALLOW TEMPS TO FALL INTO THE U40S TO M50S FROM THE CAPITAL REGION/MOHAWK VALLEY SOUTH AND EAST...AND MAINLY 40-45F NORTH OF ALBANY WITH A FEW U30S OVER THE SRN DACKS. SATURDAY...THE LAST FULL DAY OF SPRING WILL BE A NICE START TO THE WEEKEND IS EXPECTED WITH THE SFC HIGH MOVING EAST OF NEW ENGLAND DURING THE AFTERNOON. HOWEVER...INCREASING MID AND HIGH CLOUDS FROM THE SOUTH AND WEST IN ADVANCE OF A WARM FRONT OVER THE OH VALLEY AND MID ATLANTIC STATES. THE REMNANT CIRCULATION FROM BILL WILL ALSO APPROACH THE OH RIVER VALLEY. A FEW SHOWERS MAY POP UP LATE IN THE DAY MAINLY TO THE WEST AND SOUTH OF ALBANY. OTHERWISE FAIR AND DRY CONDITIONS ARE EXPECTED FOR MOST OF THE AREA WITH HIGHS MAINLY IN THE LOW TO MID 70S IN THE LOWER ELEVATIONS...AND M60S TO U60S OVER THE MTNS. SATURDAY NIGHT INTO SUNDAY...WARM FRONT ADVANCES NORTHWARD WITH THICKENING CLOUD COVERAGE ALONG WITH INCREASING PROBABILITIES FOR SHOWERS AND SOME EMBEDDED THUNDERSTORMS AS PWATS CLIMB TO BETWEEN 1.50-2.00 INCHES ALONG WITH NEGATIVE SHOWALTER VALUES. MEANWHILE...REMNANTS OF BILL ARE PROGGED TO TRACK ALONG OR SOUTH OF I80 WITH THE NAM THE FURTHEST NORTH WITH ITS TRACK THROUGH SUNDAY. AS PER THE LATEST SWODY3...ALL OF OUR REGION IS WITHIN A MARGINAL RISK FOR SEVERE THUNDERSTORMS /5%/. A CLOSER EXAMINATION OF SURFACE BASED INSTABILITY...WITH DEWPOINTS EXPECTED TO BE WELL INTO THE 60S...SBCAPES CLIMB TO BETWEEN 1K-2K J/KG MAINLY ACROSS OUR EASTERN NY COUNTIES. HOWEVER...WITH PWATS EXPECTED TO BE 2-3 STANDARD DEVIATIONS ABOVE NORMAL AND MARGINAL SHEAR PROFILES OF 25-30KTS...SOME ORGANIZED CONVECTIVE ELEMENTS WITH WET MICROBUST POTENTIAL AND LOCALLY HEAVY RAINFALL. SUNDAY NIGHT...IN THE WAKE OF BILL...UPSTREAM SHORT WAVE AND WEAK SURFACE REFLECTION WILL TRANSVERSE THE REGION. THIS WILL KEEP THE THREAT FOR MORE SHOWERS AND EMBEDDED THUNDERSTORMS /ESPECIALLY DURING THE EVENING HOURS/. OVERALL COVERAGE DOES DIMINISH WITH THE COMBINATION OF THE LOSS WITH DAYTIME HEATING AND SOME SUBSIDENCE IN THE WAKE OF BILL. WE WILL LOWER POPS TO CHC-SCT ACROSS MOST OF THE REGION WITH SLIGHT CHANCE POPS FOR THE MID HUDSON VALLEY INTO NW CT. IT WILL BE RATHER WARM AND MUGGY WITH MAINLY 60S FOR BOTH TEMPS AND DEWPOINTS. && .LONG TERM /MONDAY THROUGH THURSDAY/... THE EXTENDED PERIOD STILL LOOKS RATHER ACTIVE AS A FAIRLY UNSEASONABLY STRONG UPPER LEVEL JET REMAINS PERCHED JUST TO THE NORTH OF A STRONG RIDGE ANCHORED OVER THE SOUTHEAST...AND MUCH COOLER AIR OVER EASTERN CANADA. A SERIES OF MCS AND PERHAPS A MORE SIGNIFICANT LOW PRESSURE WILL PROPAGATE UNDERNEATH THE JET (RIDGE ROLLERS). TIMING THOUGH CHALLENGING WAS SURPRISINGLY PRETTY CONSISTENT AMONGST THE 00Z GFS/ECMWF AND CANADIAN LONG RANGE METEOROLOGICAL MODELS. MONDAY ACTUALLY LOOKS DRY WITH A BUBBLE OF HIGH PRESSURE BUILDING IN FROM CANADA TO BRING A DRY WARM DAY TO OUR PARTS. THEN...ON TUESDAY ANOTHER WEAK DISTURBANCE MIGHT TRIGGER ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS. THE ECMWF WAS MOST ROBUST WITH THIS FEATURE AND WPC LEANED WITH THIS SOLUTION. THAT SYSTEM IS GONE BY WEDNESDAY...AND WEAK SURFACE HIGH MIGHT BE ENOUGH TO KEEP IT DRY. WEDNESDAY NIGHT A MCS IS FORECAST TO MOVE MAINLY SOUTH OF OUR REGION...BUT IT MIGHT CLIP MAINLY OUR SOUTHERN AREAS. FOR NOW WENT SLIGHT CHANCES EVERYWHERE WEDNESDAY NIGHT. THURSDAY STARTS OUT DRY BUT BY THURSDAY NIGHT INTO FRIDAY...ANOTHER LOW PRESSURE IS FORECAST TO TRAVERSE FROM THE OHIO VALLEY ACROSS OUR REGION. THE 00Z GFS IS SLIGHTLY STRONGER AND SLIGHTLY SLOWER WITH THIS SYSTEM. EITHER WAY...IT LOOKS LIKE YET ANOTHER SHOT OF SHOWERS OR PERHAPS EVEN A PERIOD OF STEADY RAIN MAINLY FOR FRIDAY. TEMPERATURES START OUT WARM FOR MONDAY WITH HIGHS IN THE 80S...LOCALLY MID 80S IN THE CAPITAL REGION...UPPER 80S SOUTH AND LOWER 80S WELL NORTH OF ALBANY. AFTER THAT...TEMPERATURES LOOK SLIGHTLY BELOW FOR THE REMAINDER OF THE EXTENDED PERIOD. THIS WILL TRANSLATE TO HIGHS IN THE 70S...TO NEAR 80 SOUTH...MOST DAYS WITH LOWS IN THE 50S TO NEAR 60. PRECIPITATION LOOK TO CONTINUE TO RUN ABOVE NORMAL DURING THE EXTENDED PERIOD. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... CIGS HAVE BEEN MAINLY IFR EARLY THIS MORNING (LOW IFR AT KPOU AND KPSF)...OCCASIONALLY LIFTING TO LOW MVFR. A COLD FRONT WAS IN THE PROCESS OF CROSSING THE TERMINALS...AND SHOULD CLEAR KGFL WITHIN THE HOUR...NOT CLEARING KPOU UNTIL AFTER 12Z. SHOWERS WERE WIDELY SCATTERED WITH THIS COLD FRONT...BUT AGAIN THE BIGGER IMPACT HAS BEEN LOW STRATUS. WE STILL BELIEVE THIS STRATUS WILL LIFT AFTER 12Z. THE SURFACE WIND WHICH HAS BEEN MAINLY SOUTHERLY...WILL CONTINUE TO DO SO THROUGH ABOUT 12Z...THEN SHIFT TO THE W/NW AND THEN EVENTUALLY NORTH THROUGH THE MORNING HOURS AFTER THE MORNING PEAK. THE WIND WILL AVERAGE AROUND 10KTS...GUSTING UP TO 20KTS BY MIDDAY AT KPSF AND KALB. CLOUDS WILL LIFT BACK TO VFR AFTER 12Z...THEN EVENTUALLY BECOME SCATTERED (EXCEPT AT KPOU WHERE A BKN CIG IS LIKELY MUCH OF THE DAY BUT AGAIN AT 4500 KFT). BY THIS EVENING...EXPECT A CLEAR SKY UNRESTRICTED VISIBILITY AND LIGHT WIND. THERE MIGHT BE SOME PATCHY FOG FORMING OVERNIGHT AND WE WILL ADDRESS THAT POSSIBILITY MORE IN THE 12Z TAF ISSUANCE. OUTLOOK... SATURDAY: LOW OPERATIONAL IMPACT. SLIGHT CHC SHRA. SATURDAY NIGHT AND SUNDAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA. SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. MONDAY: NO OPERATIONAL IMPACT. NO SIG WX. MONDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...TSRA. TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. && .FIRE WEATHER... AS A COLD FRONT SLIDES ACROSS THE REGION FROM NORTH TO SOUTH...A BAND OF SHOWERS AND EMBEDDED THUNDERSTORMS WILL ACCOMPANY ITS PASSAGE. THIS FRONT MAY SLOW AS IT APPROACHES THE MID HUDSON VALLEY WHERE THE SLIGHT CHANCE FOR ADDITIONAL SHOWERS ALONG WITH SOME WEAK WIND CONVERGENCE INTO THE MID HUDSON VALLEY TO SUPPORT A SLIGHT CHANCE FOR SHOWERS. OTHERWISE...DRIER CONDITIONS WILL BE ADVECTING INTO THE MOST OF OUR CENTRAL AND NORTHERN AREAS WHERE MIN RH VALUES DROP TO BETWEEN 35 AND 45 PERCENT...WITH NEAR 50 PERCENT SOUTH OF I90. WINDS WILL BE SHIFTING TO A NORTHERLY DIRECTION THROUGH THE DAY WITH SPEEDS AROUND 10 MPH WITH SOME HIGHER GUSTS. DRIER WEATHER EXPECTED TONIGHT AS HIGH PRESSURE SLIDES ACROSS THE REGION. LIGHT AND VARIABLE TO CALM WINDS EXPECTED AS RH VALUES CLIMB TO BETWEEN 65 AND 85 PERCENT. MOISTURE RETURNS THIS WEEKEND WITH INCREASING CHANCE FOR SHOWERS AND THUNDERSTORMS. && .HYDROLOGY... AREA RIVERS AND STREAMS WILL LIKELY EXHIBIT AN INCREASE OF WITHIN BANK FLOWS THIS WEEKEND AS THE COMBINATION OF HIGHER MOISTURE CONTENT AND THE REMNANTS OF BILL PASSING TO THE SOUTH OF OUR LOCAL REGION. PWATS ARE EXPECTED TO CLIMB TO BETWEEN 1.50-2.00 INCHES THIS WEEKEND WHICH IS 2-3 STANDARD DEVIATIONS ABOVE NORMAL AND ANY CONVECTION MAY PRODUCE LOCALLY HEAVY RAINFALL. AT THE PRESENT TIME...QPF FROM THE VAST ARRAY OF GUIDANCE SUGGEST BASIN AVERAGES WOULD BE AROUND 1 INCH. 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...BGM NEAR TERM...BGM SHORT TERM...BGM/WASULA LONG TERM...HWJIV AVIATION...HWJIV FIRE WEATHER...BGM/WASULA HYDROLOGY...BGM/WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
527 AM EDT FRI JUN 19 2015 .SYNOPSIS... A COLD FRONT WILL SLOWLY SLIDE SOUTH OF THE REGION TODAY AS HIGH PRESSURE BUILDS IN FROM THE GREAT LAKES REGION. COOLER AND DRIER WEATHER WILL CONTINUE INTO THE FIRST HALF OF THE WEEKEND...AS WET AND UNSETTLED WEATHER CONDITIONS RETURNS SATURDAY NIGHT INTO SUNDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 400 AM EDT...A LINE OF CONVECTION CONTINUES TO SLOWLY SLIDE SOUTHWARD AS THE COLD FRONT WAS MOVING THROUGH THE ADIRONDACK PARK. LATEST TRENDS IN THE NCEP MODEL SUITE ALONG WITH THE HOURLY RAP/HRRR...CONTINUE TO SUPPORT A SOMEWHAT SLOWER EXIT OF THIS FRONT AS WE WILL NEED TO RETAIN SOME POPS THROUGH THE MORNING FOR LOCATIONS JUST TO THE SOUTH OF I90 THEN THROUGH THE I84 CORRIDOR INTO THE EARLY AFTERNOON HOURS. IN FACT...MESOSCALE LOW LEVEL CONVERGENCE INTO THE HUDSON VALLEY MAY BE ENOUGH FOR ADDITIONAL CLOUD COVER AND A PASSING SHOWER. TRENDS IN THE HRRR REFLECTIVITY FORECASTS ALSO SUGGEST THIS SLIGHT CHANCE POSSIBILITY ALONG WITH SHORT TERM ENSEMBLES. OTHERWISE...SURFACE HIGH WILL BE BUILDING ACROSS THE EASTERN GREAT LAKES REGION AND INTO THE ADIRONDACK STATE PARK THROUGH THE DAY AS H850 TEMPS SETTLE BACK INTO THE MID-UPR SINGLE DIGITS FOR THE DACKS/LAKE GEORGE SARATOGA REGION TO AROUND 10C ALONG AND SOUTH OF THE I90 CORRIDOR. THIS WOULD SUGGEST TEMPERATURES WILL AVERAGE INTO THE 60S ACROSS THE NORTH AND INTO THE HIGHER TERRAIN OF THE SOUTHERN GREENS TO AROUND 80F FOR THE MID HUDSON VALLEY AND SOUTHERN LITCHFIELD COUNTY CT. LOW LEVEL DRY ADVECTION WILL RESULT IN A DROP IN DEWPOINTS AS WE FALL FROM THE 60S THIS EARLY MORNING TO UPPER 40S ACROSS THE NORTH...50S FOR MOST THE REGION BUT HANGING AROUND 60F FOR THE MID HUDSON VALLEY AND NW CT WHERE THE AFOREMENTIONED SLIGHT CHANCE POPS WILL REMAIN. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/... TONIGHT...A CLEAR/MOSTLY CLEAR NIGHT IS EXPECTED ACROSS MOST OF THE REGION WITH DIMINISHING WINDS THAT BECOME LIGHT TO CALM...AS THE SFC HIGH MOVES OVERHEARD. THE EXCEPTION TO THIS WOULD BE FOR THE MID HUDSON VALLEY AND NW CT WHERE LOW LEVEL FLOW IS EXPECTED TO ONCE AGAIN BECOME SOUTHERLY WITH MOISTURE ADVECTING BACK NORTHWARD. AS THE CANADIAN AIR MASS SETTLES SOUTHWARD FOR MOST OF THE REGION...H850 TEMPS WILL BE IN THE +7C TO +10C RANGE. IDEAL RADIATIONAL COOLING CONDITIONS ACROSS THE NORTHERN 2/3RDS OF THE CWFA WILL ALLOW TEMPS TO FALL INTO THE U40S TO M50S FROM THE CAPITAL REGION/MOHAWK VALLEY SOUTH AND EAST...AND MAINLY 40-45F NORTH OF ALBANY WITH A FEW U30S OVER THE SRN DACKS. SATURDAY...THE LAST FULL DAY OF SPRING WILL BE A NICE START TO THE WEEKEND IS EXPECTED WITH THE SFC HIGH MOVING EAST OF NEW ENGLAND DURING THE AFTERNOON. HOWEVER...INCREASING MID AND HIGH CLOUDS FROM THE SOUTH AND WEST IN ADVANCE OF A WARM FRONT OVER THE OH VALLEY AND MID ATLANTIC STATES. THE REMNANT CIRCULATION FROM BILL WILL ALSO APPROACH THE OH RIVER VALLEY. A FEW SHOWERS MAY POP UP LATE IN THE DAY MAINLY TO THE WEST AND SOUTH OF ALBANY. OTHERWISE FAIR AND DRY CONDITIONS ARE EXPECTED FOR MOST OF THE AREA WITH HIGHS MAINLY IN THE LOW TO MID 70S IN THE LOWER ELEVATIONS...AND M60S TO U60S OVER THE MTNS. SATURDAY NIGHT INTO SUNDAY...WARM FRONT ADVANCES NORTHWARD WITH THICKENING CLOUD COVERAGE ALONG WITH INCREASING PROBABILITIES FOR SHOWERS AND SOME EMBEDDED THUNDERSTORMS AS PWATS CLIMB TO BETWEEN 1.50-2.00 INCHES ALONG WITH NEGATIVE SHOWALTER VALUES. MEANWHILE...REMNANTS OF BILL ARE PROGGED TO TRACK ALONG OR SOUTH OF I80 WITH THE NAM THE FURTHEST NORTH WITH ITS TRACK THROUGH SUNDAY. AS PER THE LATEST SWODY3...ALL OF OUR REGION IS WITHIN A MARGINAL RISK FOR SEVERE THUNDERSTORMS /5%/. A CLOSER EXAMINATION OF SURFACE BASED INSTABILITY...WITH DEWPOINTS EXPECTED TO BE WELL INTO THE 60S...SBCAPES CLIMB TO BETWEEN 1K-2K J/KG MAINLY ACROSS OUR EASTERN NY COUNTIES. HOWEVER...WITH PWATS EXPECTED TO BE 2-3 STANDARD DEVIATIONS ABOVE NORMAL AND MARGINAL SHEAR PROFILES OF 25-30KTS...SOME ORGANIZED CONVECTIVE ELEMENTS WITH WET MICROBUST POTENTIAL AND LOCALLY HEAVY RAINFALL. SUNDAY NIGHT...IN THE WAKE OF BILL...UPSTREAM SHORT WAVE AND WEAK SURFACE REFLECTION WILL TRANSVERSE THE REGION. THIS WILL KEEP THE THREAT FOR MORE SHOWERS AND EMBEDDED THUNDERSTORMS /ESPECIALLY DURING THE EVENING HOURS/. OVERALL COVERAGE DOES DIMINISH WITH THE COMBINATION OF THE LOSS WITH DAYTIME HEATING AND SOME SUBSIDENCE IN THE WAKE OF BILL. WE WILL LOWER POPS TO CHC-SCT ACROSS MOST OF THE REGION WITH SLIGHT CHANCE POPS FOR THE MID HUDSON VALLEY INTO NW CT. IT WILL BE RATHER WARM AND MUGGY WITH MAINLY 60S FOR BOTH TEMPS AND DEWPOINTS. && .LONG TERM /MONDAY THROUGH THURSDAY/... THE EXTENDED PERIOD STILL LOOKS RATHER ACTIVE AS A FAIRLY UNSEASONABLY STRONG UPPER LEVEL JET REMAINS PERCHED JUST TO THE NORTH OF A STRONG RIDGE ANCHORED OVER THE SOUTHEAST...AND MUCH COOLER AIR OVER EASTERN CANADA. A SERIES OF MCS AND PERHAPS A MORE SIGNIFICANT LOW PRESSURE WILL PROPAGATE UNDERNEATH THE JET (RIDGE ROLLERS). TIMING THOUGH CHALLENGING WAS SURPRISINGLY PRETTY CONSISTENT AMONGST THE 00Z GFS/ECMWF AND CANADIAN LONG RANGE METEOROLOGICAL MODELS. MONDAY ACTUALLY LOOKS DRY WITH A BUBBLE OF HIGH PRESSURE BUILDING IN FROM CANADA TO BRING A DRY WARM DAY TO OUR PARTS. THEN...ON TUESDAY ANOTHER WEAK DISTURBANCE MIGHT TRIGGER ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS. THE ECMWF WAS MOST ROBUST WITH THIS FEATURE AND WPC LEANED WITH THIS SOLUTION. THAT SYSTEM IS GONE BY WEDNESDAY...AND WEAK SURFACE HIGH MIGHT BE ENOUGH TO KEEP IT DRY. WEDNESDAY NIGHT A MCS IS FORECAST TO MOVE MAINLY SOUTH OF OUR REGION...BUT IT MIGHT CLIP MAINLY OUR SOUTHERN AREAS. FOR NOW WENT SLIGHT CHANCES EVERYWHERE WEDNESDAY NIGHT. THURSDAY STARTS OUT DRY BUT BY THURSDAY NIGHT INTO FRIDAY...ANOTHER LOW PRESSURE IS FORECAST TO TRAVERSE FROM THE OHIO VALLEY ACROSS OUR REGION. THE 00Z GFS IS SLIGHTLY STRONGER AND SLIGHTLY SLOWER WITH THIS SYSTEM. EITHER WAY...IT LOOKS LIKE YET ANOTHER SHOT OF SHOWERS OR PERHAPS EVEN A PERIOD OF STEADY RAIN MAINLY FOR FRIDAY. TEMPERATURES START OUT WARM FOR MONDAY WITH HIGHS IN THE 80S...LOCALLY MID 80S IN THE CAPITAL REGION...UPPER 80S SOUTH AND LOWER 80S WELL NORTH OF ALBANY. AFTER THAT...TEMPERATURES LOOK SLIGHTLY BELOW FOR THE REMAINDER OF THE EXTENDED PERIOD. THIS WILL TRANSLATE TO HIGHS IN THE 70S...TO NEAR 80 SOUTH...MOST DAYS WITH LOWS IN THE 50S TO NEAR 60. PRECIPITATION LOOK TO CONTINUE TO RUN ABOVE NORMAL DURING THE EXTENDED PERIOD. && .AVIATION /09Z FRIDAY THROUGH TUESDAY/... CIGS HAVE BEEN MAINLY IFR EARLY THIS MORNING (LOW IFR AT KPOU AND KPSF)...OCCASIONALLY LIFTING TO LOW MVFR. A COLD FRONT WAS IN THE PROCESS OF CROSSING THE TERMINALS...AND SHOULD CLEAR KGFL WITHIN THE HOUR...NOT CLEARING KPOU UNTIL AFTER 12Z. SHOWERS WERE WIDELY SCATTERED WITH THIS COLD FRONT...BUT AGAIN THE BIGGER IMPACT HAS BEEN LOW STRATUS. WE STILL BELIEVE THIS STRATUS WILL LIFT AFTER 12Z. THE SURFACE WIND WHICH HAS BEEN MAINLY SOUTHERLY...WILL CONTINUE TO DO SO THROUGH ABOUT 12Z...THEN SHIFT TO THE W/NW AND THEN EVENTUALLY NORTH THROUGH THE MORNING HOURS AFTER THE MORNING PEAK. THE WIND WILL AVERAGE AROUND 10KTS...GUSTING UP TO 20KTS BY MIDDAY AT KPSF AND KALB. CLOUDS WILL LIFT BACK TO VFR AFTER 12Z...THEN EVENTUALLY BECOME SCATTERED (EXCEPT AT KPOU WHERE A BKN CIG IS LIKELY MUCH OF THE DAY BUT AGAIN AT 4500 KFT). BY THIS EVENING...EXPECT A CLEAR SKY UNRESTRICTED VISIBILITY AND LIGHT WIND. THERE MIGHT BE SOME PATCHY FOG FORMING OVERNIGHT AND WE WILL ADDRESS THAT POSSIBILITY MORE IN THE 12Z TAF ISSUANCE. OUTLOOK... SATURDAY: LOW OPERATIONAL IMPACT. SLIGHT CHC SHRA. SATURDAY NIGHT AND SUNDAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA. SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. MONDAY: NO OPERATIONAL IMPACT. NO SIG WX. MONDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...TSRA. TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. && .FIRE WEATHER... AS A COLD FRONT SLIDES ACROSS THE REGION FROM NORTH TO SOUTH...A BAND OF SHOWERS AND EMBEDDED THUNDERSTORMS WILL ACCOMPANY ITS PASSAGE. THIS FRONT MAY SLOW AS IT APPROACHES THE MID HUDSON VALLEY WHERE THE SLIGHT CHANCE FOR ADDITIONAL SHOWERS ALONG WITH SOME WEAK WIND CONVERGENCE INTO THE MID HUDSON VALLEY TO SUPPORT A SLIGHT CHANCE FOR SHOWERS. OTHERWISE...DRIER CONDITIONS WILL BE ADVECTING INTO THE MOST OF OUR CENTRAL AND NORTHERN AREAS WHERE MIN RH VALUES DROP TO BETWEEN 35 AND 45 PERCENT...WITH NEAR 50 PERCENT SOUTH OF I90. WINDS WILL BE SHIFTING TO A NORTHERLY DIRECTION THROUGH THE DAY WITH SPEEDS AROUND 10 MPH WITH SOME HIGHER GUSTS. DRIER WEATHER EXPECTED TONIGHT AS HIGH PRESSURE SLIDES ACROSS THE REGION. LIGHT AND VARIABLE TO CALM WINDS EXPECTED AS RH VALUES CLIMB TO BETWEEN 65 AND 85 PERCENT. MOISTURE RETURNS THIS WEEKEND WITH INCREASING CHANCE FOR SHOWERS AND THUNDERSTORMS. && .HYDROLOGY... AREA RIVERS AND STREAMS WILL LIKELY EXHIBIT AN INCREASE OF WITHIN BANK FLOWS THIS WEEKEND AS THE COMBINATION OF HIGHER MOISTURE CONTENT AND THE REMNANTS OF BILL PASSING TO THE SOUTH OF OUR LOCAL REGION. PWATS ARE EXPECTED TO CLIMB TO BETWEEN 1.50-2.00 INCHES THIS WEEKEND WHICH IS 2-3 STANDARD DEVIATIONS ABOVE NORMAL AND ANY CONVECTION MAY PRODUCE LOCALLY HEAVY RAINFALL. AT THE PRESENT TIME...QPF FROM THE VAST ARRAY OF GUIDANCE SUGGEST BASIN AVERAGES WOULD BE AROUND 1 INCH. 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...BGM NEAR TERM...BGM SHORT TERM...BGM/WASULA LONG TERM...HWJIV AVIATION...HWJIV FIRE WEATHER...BGM/WASULA HYDROLOGY...BGM/WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
427 AM EDT FRI JUN 19 2015 .SYNOPSIS... A COLD FRONT WILL SLOWLY SLIDE SOUTH OF THE REGION TODAY AS HIGH PRESSURE BUILDS IN FROM THE GREAT LAKES REGION. COOLER AND DRIER WEATHER WILL CONTINUE INTO THE FIRST HALF OF THE WEEKEND...AS WET AND UNSETTLED WEATHER CONDITIONS RETURNS SATURDAY NIGHT INTO SUNDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 400 AM EDT...A LINE OF CONVECTION CONTINUES TO SLOWLY SLIDE SOUTHWARD AS THE COLD FRONT WAS MOVING THROUGH THE ADIRONDACK PARK. LATEST TRENDS IN THE NCEP MODEL SUITE ALONG WITH THE HOURLY RAP/HRRR...CONTINUE TO SUPPORT A SOMEWHAT SLOWER EXIT OF THIS FRONT AS WE WILL NEED TO RETAIN SOME POPS THROUGH THE MORNING FOR LOCATIONS JUST TO THE SOUTH OF I90 THEN THROUGH THE I84 CORRIDOR INTO THE EARLY AFTERNOON HOURS. IN FACT...MESOSCALE LOW LEVEL CONVERGENCE INTO THE HUDSON VALLEY MAY BE ENOUGH FOR ADDITIONAL CLOUD COVER AND A PASSING SHOWER. TRENDS IN THE HRRR REFLECTIVITY FORECASTS ALSO SUGGEST THIS SLIGHT CHANCE POSSIBILITY ALONG WITH SHORT TERM ENSEMBLES. OTHERWISE...SURFACE HIGH WILL BE BUILDING ACROSS THE EASTERN GREAT LAKES REGION AND INTO THE ADIRONDACK STATE PARK THROUGH THE DAY AS H850 TEMPS SETTLE BACK INTO THE MID-UPR SINGLE DIGITS FOR THE DACKS/LAKE GEORGE SARATOGA REGION TO AROUND 10C ALONG AND SOUTH OF THE I90 CORRIDOR. THIS WOULD SUGGEST TEMPERATURES WILL AVERAGE INTO THE 60S ACROSS THE NORTH AND INTO THE HIGHER TERRAIN OF THE SOUTHERN GREENS TO AROUND 80F FOR THE MID HUDSON VALLEY AND SOUTHERN LITCHFIELD COUNTY CT. LOW LEVEL DRY ADVECTION WILL RESULT IN A DROP IN DEWPOINTS AS WE FALL FROM THE 60S THIS EARLY MORNING TO UPPER 40S ACROSS THE NORTH...50S FOR MOST THE REGION BUT HANGING AROUND 60F FOR THE MID HUDSON VALLEY AND NW CT WHERE THE AFOREMENTIONED SLIGHT CHANCE POPS WILL REMAIN. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/... TONIGHT...A CLEAR/MOSTLY CLEAR NIGHT IS EXPECTED ACROSS MOST OF THE REGION WITH DIMINISHING WINDS THAT BECOME LIGHT TO CALM...AS THE SFC HIGH MOVES OVERHEARD. THE EXCEPTION TO THIS WOULD BE FOR THE MID HUDSON VALLEY AND NW CT WHERE LOW LEVEL FLOW IS EXPECTED TO ONCE AGAIN BECOME SOUTHERLY WITH MOISTURE ADVECTING BACK NORTHWARD. AS THE CANADIAN AIR MASS SETTLES SOUTHWARD FOR MOST OF THE REGION...H850 TEMPS WILL BE IN THE +7C TO +10C RANGE. IDEAL RADIATIONAL COOLING CONDITIONS ACROSS THE NORTHERN 2/3RDS OF THE CWFA WILL ALLOW TEMPS TO FALL INTO THE U40S TO M50S FROM THE CAPITAL REGION/MOHAWK VALLEY SOUTH AND EAST...AND MAINLY 40-45F NORTH OF ALBANY WITH A FEW U30S OVER THE SRN DACKS. SATURDAY...THE LAST FULL DAY OF SPRING WILL BE A NICE START TO THE WEEKEND IS EXPECTED WITH THE SFC HIGH MOVING EAST OF NEW ENGLAND DURING THE AFTERNOON. HOWEVER...INCREASING MID AND HIGH CLOUDS FROM THE SOUTH AND WEST IN ADVANCE OF A WARM FRONT OVER THE OH VALLEY AND MID ATLANTIC STATES. THE REMNANT CIRCULATION FROM BILL WILL ALSO APPROACH THE OH RIVER VALLEY. A FEW SHOWERS MAY POP UP LATE IN THE DAY MAINLY TO THE WEST AND SOUTH OF ALBANY. OTHERWISE FAIR AND DRY CONDITIONS ARE EXPECTED FOR MOST OF THE AREA WITH HIGHS MAINLY IN THE LOW TO MID 70S IN THE LOWER ELEVATIONS...AND M60S TO U60S OVER THE MTNS. SATURDAY NIGHT INTO SUNDAY...WARM FRONT ADVANCES NORTHWARD WITH THICKENING CLOUD COVERAGE ALONG WITH INCREASING PROBABILITIES FOR SHOWERS AND SOME EMBEDDED THUNDERSTORMS AS PWATS CLIMB TO BETWEEN 1.50-2.00 INCHES ALONG WITH NEGATIVE SHOWALTER VALUES. MEANWHILE...REMNANTS OF BILL ARE PROGGED TO TRACK ALONG OR SOUTH OF I80 WITH THE NAM THE FURTHEST NORTH WITH ITS TRACK THROUGH SUNDAY. AS PER THE LATEST SWODY3...ALL OF OUR REGION IS WITHIN A MARGINAL RISK FOR SEVERE THUNDERSTORMS /5%/. A CLOSER EXAMINATION OF SURFACE BASED INSTABILITY...WITH DEWPOINTS EXPECTED TO BE WELL INTO THE 60S...SBCAPES CLIMB TO BETWEEN 1K-2K J/KG MAINLY ACROSS OUR EASTERN NY COUNTIES. HOWEVER...WITH PWATS EXPECTED TO BE 2-3 STANDARD DEVIATIONS ABOVE NORMAL AND MARGINAL SHEAR PROFILES OF 25-30KTS...SOME ORGANIZED CONVECTIVE ELEMENTS WITH WET MICROBUST POTENTIAL AND LOCALLY HEAVY RAINFALL. SUNDAY NIGHT...IN THE WAKE OF BILL...UPSTREAM SHORT WAVE AND WEAK SURFACE REFLECTION WILL TRANSVERSE THE REGION. THIS WILL KEEP THE THREAT FOR MORE SHOWERS AND EMBEDDED THUNDERSTORMS /ESPECIALLY DURING THE EVENING HOURS/. OVERALL COVERAGE DOES DIMINISH WITH THE COMBINATION OF THE LOSS WITH DAYTIME HEATING AND SOME SUBSIDENCE IN THE WAKE OF BILL. WE WILL LOWER POPS TO CHC-SCT ACROSS MOST OF THE REGION WITH SLIGHT CHANCE POPS FOR THE MID HUDSON VALLEY INTO NW CT. IT WILL BE RATHER WARM AND MUGGY WITH MAINLY 60S FOR BOTH TEMPS AND DEWPOINTS. && .LONG TERM /MONDAY THROUGH THURSDAY/... THE EXTENDED PERIOD STILL LOOKS RATHER ACTIVE AS A FAIRLY UNSEASONABLY STRONG UPPER LEVEL JET REMAINS PERCHED JUST TO THE NORTH OF A STRONG RIDGE ANCHORED OVER THE SOUTHEAST...AND MUCH COOLER AIR OVER EASTERN CANADA. A SERIES OF MCS AND PERHAPS A MORE SIGNIFICANT LOW PRESSURE WILL PROPAGATE UNDERNEATH THE JET (RIDGE ROLLERS). TIMING THOUGH CHALLENGING WAS SURPRISINGLY PRETTY CONSISTENT AMONGST THE 00Z GFS/ECMWF AND CANADIAN LONG RANGE METEOROLOGICAL MODELS. MONDAY ACTUALLY LOOKS DRY WITH A BUBBLE OF HIGH PRESSURE BUILDING IN FROM CANADA TO BRING A DRY WARM DAY TO OUR PARTS. THEN...ON TUESDAY ANOTHER WEAK DISTURBANCE MIGHT TRIGGER ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS. THE ECMWF WAS MOST ROBUST WITH THIS FEATURE AND WPC LEANED WITH THIS SOLUTION. THAT SYSTEM IS GONE BY WEDNESDAY...AND WEAK SURFACE HIGH MIGHT BE ENOUGH TO KEEP IT DRY. WEDNESDAY NIGHT A MCS IS FORECAST TO MOVE MAINLY SOUTH OF OUR REGION...BUT IT MIGHT CLIP MAINLY OUR SOUTHERN AREAS. FOR NOW WENT SLIGHT CHANCES EVERYWHERE WEDNESDAY NIGHT. THURSDAY STARTS OUT DRY BUT BY THURSDAY NIGHT INTO FRIDAY...ANOTHER LOW PRESSURE IS FORECAST TO TRAVERSE FROM THE OHIO VALLEY ACROSS OUR REGION. THE 00Z GFS IS SLIGHTLY STRONGER AND SLIGHTLY SLOWER WITH THIS SYSTEM. EITHER WAY...IT LOOKS LIKE YET ANOTHER SHOT OF SHOWERS OR PERHAPS EVEN A PERIOD OF STEADY RAIN MAINLY FOR FRIDAY. TEMPERATURES START OUT WARM FOR MONDAY WITH HIGHS IN THE 80S...LOCALLY MID 80S IN THE CAPITAL REGION...UPPER 80S SOUTH AND LOWER 80S WELL NORTH OF ALBANY. AFTER THAT...TEMPERATURES LOOK SLIGHTLY BELOW FOR THE REMAINDER OF THE EXTENDED PERIOD. THIS WILL TRANSLATE TO HIGHS IN THE 70S...TO NEAR 80 SOUTH...MOST DAYS WITH LOWS IN THE 50S TO NEAR 60. PRECIPITATION LOOK TO CONTINUE TO RUN ABOVE NORMAL DURING THE EXTENDED PERIOD. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... MAINLY MVFR CONDITIONS EXPECTED THROUGH 12Z...THEN VFR THEREAFTER. A COLD FRONT MOVING THROUGH OVERNIGHT WILL PRODUCE SCATTERED SHOWERS. RADARS INDICATED A LITTLE MORE ACTIVITY REGARDING SCATTERED SHOWERS WORKING INTO THE TAF SITES. THERE WAS AN EARLIER LIGHTNING STRIKE OR TWO ASSOCIATED WITH CONVECTION JUST NORTH OF KGFL. AS OF 540Z...THERE HAD BEEN NONE IN THE BETTER PART OF AN HOUR. EXPECT OCCASIONAL IFR CIGS TONIGHT DUE BUT PREVAILING LOW MVFR (EXTRA FUEL REQUIRED) THROUGH THE MORNING PEAK AT ALL THE TAF SITES. VISIBILITY WILL BE MAINLY VFR BUT OCCASIONAL DOWN TO MVFR IN SHOWERS AND MIST. THE WIND WHICH HAS BEEN MAINLY SOUTHERLY...WILL CONTINUE TO DO SO THROUGH ABOUT 10Z...THEN SHIFT TO THE W/NW AND THEN EVENTUALLY NORTH THROUGH THE MORNING HOURS AFTER THE MORNING PEAK. THEY WILL AVERAGE AROUND 10KTS...GUSTING UP TO 20KTS BY MIDDAY AT KPSF AND KALB. CLOUDS WILL LIFT BACK TO VFR AFTER 12Z...THEN EVENTUALLY BECOME SCATTERED (EXCEPT AT KPOU WHERE A BKN CIG IS LIKELY MUCH OF THE DAY BUT AGAIN AT 4500 KFT). BY THIS EVENING...EXPECT A CLEAR SKY UNRESTRICTED VISIBILITY AND LIGHT WIND. THERE MIGHT BE SOME PATCHY FOG FORMING OVERNIGHT AND WE WILL ADDRESS THAT POSSIBILITY MORE IN THE 12Z TAF ISSUANCE. OUTLOOK... FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY NIGHT: MODERATE OPERATIONAL IMPACT. LIKELY SHRA...TSRA. SUNDAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA. SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. MONDAY: NO OPERATIONAL IMPACT. NO SIG WX. MONDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...TSRA. TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. && .FIRE WEATHER... AS A COLD FRONT SLIDES ACROSS THE REGION FROM NORTH TO SOUTH...A BAND OF SHOWERS AND EMBEDDED THUNDERSTORMS WILL ACCOMPANY ITS PASSAGE. THIS FRONT MAY SLOW AS IT APPROACHES THE MID HUDSON VALLEY WHERE THE SLIGHT CHANCE FOR ADDITIONAL SHOWERS ALONG WITH SOME WEAK WIND CONVERGENCE INTO THE MID HUDSON VALLEY TO SUPPORT A SLIGHT CHANCE FOR SHOWERS. OTHERWISE...DRIER CONDITIONS WILL BE ADVECTING INTO THE MOST OF OUR CENTRAL AND NORTHERN AREAS WHERE MIN RH VALUES DROP TO BETWEEN 35 AND 45 PERCENT...WITH NEAR 50 PERCENT SOUTH OF I90. WINDS WILL BE SHIFTING TO A NORTHERLY DIRECTION THROUGH THE DAY WITH SPEEDS AROUND 10 MPH WITH SOME HIGHER GUSTS. DRIER WEATHER EXPECTED TONIGHT AS HIGH PRESSURE SLIDES ACROSS THE REGION. LIGHT AND VARIABLE TO CALM WINDS EXPECTED AS RH VALUES CLIMB TO BETWEEN 65 AND 85 PERCENT. MOISTURE RETURNS THIS WEEKEND WITH INCREASING CHANCE FOR SHOWERS AND THUNDERSTORMS. && .HYDROLOGY... AREA RIVERS AND STREAMS WILL LIKELY EXHIBIT AN INCREASE OF WITHIN BANK FLOWS THIS WEEKEND AS THE COMBINATION OF HIGHER MOISTURE CONTENT AND THE REMNANTS OF BILL PASSING TO THE SOUTH OF OUR LOCAL REGION. PWATS ARE EXPECTED TO CLIMB TO BETWEEN 1.50-2.00 INCHES THIS WEEKEND WHICH IS 2-3 STANDARD DEVIATIONS ABOVE NORMAL AND ANY CONVECTION MAY PRODUCE LOCALLY HEAVY RAINFALL. AT THE PRESENT TIME...QPF FROM THE VAST ARRAY OF GUIDANCE SUGGEST BASIN AVERAGES WOULD BE AROUND 1 INCH. 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...BGM NEAR TERM...BGM SHORT TERM...BGM/WASULA LONG TERM...HWJIV AVIATION...FRUGIS/HWJIV FIRE WEATHER...BGM/WASULA HYDROLOGY...BGM/WASULA FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS TAUNTON MA
342 AM EDT FRI JUN 19 2015 .SYNOPSIS... A COLD FRONT WILL MOVE SOUTH ACROSS THE REGION TODAY AND MAY TRIGGER AN AFTERNOON THUNDERSTORM ACROSS RI AND SOUTHEAST MA. HIGH PRESSURE BRINGS DRY AND COOLER WEATHER TONIGHT AND SATURDAY. A COLD FRONT SWEEPING FROM THE N AND THE REMNANTS OF TS BILL MOVING IN FROM THE S WILL MAKE FOR A POTENTIALLY WET SUNDAY. ANOTHER ROUND OF WET-WEATHER IS POSSIBLE MONDAY AND TUESDAY PRIOR TO COOLER AND DRY CONDITIONS WEDNESDAY AND THURSDAY. WARMER AND WET CONDITIONS ARE FORECAST TO RETURN TO THE AREA BY THE END OF THE WEEK. && .NEAR TERM /THROUGH TODAY/... WIDELY SCT SHOWERS ARE MOVING INTO SNE FROM THE WEST ASSOCD WITH WEAK INSTABILITY BURST. NOTING SOME TSTMS S OF LI AND GIVEN SOME ELEVATED INSTABILITY CANT RULE OUT AN ISOLD TSTM EARLY THIS MORNING. A FEW SHOWERS POSSIBLE AFTER DAYBREAK AHEAD OF THE COLD FRONT WHICH WILL BE MOVING S ACROSS SNE THIS MORNING. AS THE FRONT PUSHES SOUTH CLOUDS WILL GIVE WAY TO PT-MOSUNNY SKIES FROM NORTH TO SOUTH FROM LATE MORNING THROUGH THE AFTERNOON WITH CLOUDS PERSISTING THE LONGEST ALONG THE S COAST. COLD FRONT APPEARS TO GET HUNG UP NEAR THE SOUTH COAST 18-21Z BEFORE MOVING S OF NEW ENG BY 00Z. MODELS DO GENERATE MARGINAL SFC INSTABILITY NEAR THE FRONT WITH SBCAPES AROUND 500 J/KG WITHIN LOW LEVEL THETA-E RIDGE AXIS SO POTENTIAL EXISTS FOR A FEW SHOWERS OR TSTM THIS AFTERNOON...MAINLY FOCUSED ACROSS RI AND SE MA. TIMING OF DRIER AIR AND FALLING DEWPOINTS INTO THE 50S WILL BE CRITICAL TO THE INSTABILITY AND POTENTIAL TSTM DEVELOPMENT. IF THE DRIER AIR IS DELAYED AND DEWPOINTS REMAIN IN THE 60S INTO THE AFTERNOON THERE WILL BE A GREATER CHANCE OF CONVECTION BUT IF THESE LOWER DEWPOINTS MOVE IN QUICKER THIS WILL LIKELY PRECLUDE TSTM DEVELOPMENT. MODELS ALL GENERATE SOME CONVECTIVE PRECIP IN THE COASTAL PLAIN THIS AFTERNOON AND HRRR IS TARGETING RI AND SE MA SO WE HAVE CHC POPS FOCUSED ACROSS NE CT...RI AND SE MA. DEEP LAYER SHEAR IS QUITE IMPRESSIVE AROUND 40-50 KT SO ANY CONVECTION WILL HAVE TO BE MONITORED CLOSELY. CANT RULE OUT A STRONG TSTM BUT THINK MARGINAL INSTABILITY AND WEAK MID LEVEL LAPSE RATES WILL LIMIT POTENTIAL FOR STRONG STORMS. 850 MB TEMPS 12-14C AND WITH DEVELOPING SUNSHINE AND NW WINDS IT WILL BE A WARM DAY WITH HIGHS REACHING LOW TO MID 80S...EXCEPT 70S ALONG THE COAST AND OVER HIGHER ELEVATIONS IN WESTERN AND N MA. && .SHORT TERM /TONIGHT THROUGH 6 PM SATURDAY/... TONIGHT... A LINGERING SHOWER IS POSSIBLE EARLY EVENING ALONG THE S COAST WITH THE FRONT...OTHERWISE COOLER AND DRIER POST-FRONTAL AIRMASS OVERSPREADS THE REGION AS HIGH PRES BUILDS IN. CLEARING SKIES EXPECTED ACROSS NORTHERN ZONES BUT CLOUDS MAY LINGER DURING THE NIGHT ALONG THE S COAST WHERE SOME PATCHY FOG POSSIBLE. MINS MOSTLY IN THE 50S BUT SOME 40S POSSIBLE IN NORTH CENTRAL AND W MA. SATURDAY... HIGH PRES IN CONTROL AS IT MOVES E OF NEW ENG. EXPECT INCREASING AFTERNOON CLOUDS...ESPECIALLY W NEW ENG. NAM APPEARS TOO AGGRESSIVE WITH RETUNING MOISTURE AND SHOWERS SO THIS WAS DISCOUNTED AS HIGH PRES MAINTAINS DRIER AIR WITH HIGHER THETA-E AIR REMAINING TO THE WEST. COOLER TEMPS IN THE 70S WITH SEABREEZES LIKELY HOLDING TEMPS NEAR 70 ALONG THE IMMEDIATE COAST. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... HIGHLIGHTS... * STILL LOOKING WET FOR SUNDAY WITH THE REMNANTS OF TS BILL * SOME UNCERTAINTY ON EXACT OUTCOMES * WET-WEATHER IS POSSIBLE MONDAY AND TUESDAY * UNSEASONABLY COOL AND DRY WEDNESDAY AND THURSDAY * A RETURN OF WARMER-WET CONDITIONS BY THE END OF THE WEEK DISCUSSION... A FORECAST THAT CONTINUES TO WOBBLE WITH RESPECT TO TWO WEATHER DISTURBANCES SATURDAY NIGHT INTO MONDAY MORNING: 1. REMNANTS OF TS BILL AND 2. STRETCHED PACIFIC-ORIGIN ENERGY THROUGH THE QUASI-ZONAL FLOW. OF CERTAINTY REMNANTS OF TS BILL ARE ASSOCIATED WITH HIGH THETA-E AIR / +2-INCH PWATS AND MARGINAL INSTABILITY FOCUSED ALONG THE NOSE OF A H925-85 LLJ ALONG ITS E-PERIPHERY OF CYCLONIC FLOW. IT IS WITHIN THE LOW- TO MID-LEVEL CONVERGENT NOSE THERE IS A EXPECTATION OF A GOOD SLUG OF RAIN WITH EMBEDDED HEAVIER SHOWERS AND POSSIBLE THUNDERSTORMS WITHIN A MOIST-ADIABATIC PROFILE WITH HIGH FREEZING- LEVEL HEIGHTS. SUCH ANTICIPATED OUTCOMES COULD YIELD THE POSSIBILITY OF NUISANCE/URBAN/POOR-DRAINAGE FLOODING ALBEIT NOT AS CATASTROPHIC AS WHAT HAS BEEN WITNESSED UPSTREAM ACROSS TX / OK AS THE FLOW IS PROGRESSIVE AND REMNANTS ARE BEING SWEPT AHEAD OF THE AFOREMENTIONED DISTURBANCE THROUGH THE ZONAL-FLOW REGIME. BUT UNCERTAIN IS THE EXACT TRACK OF THE REMNANTS WHICH CONTINUE TO WOBBLE AND HOW IT INTERACTS WITH THE NEIGHBORING N-STREAM IMPULSE. WHILE THE TRACK HAS WOBBLED WITHIN THE LATEST FORECAST RUNS THERE IS ALSO THE QUESTION AS TO WHETHER THE LOW- TO MID-LEVEL CONVERGENCE CAN CONNECT WITH THE RRQ OF THE NEIGHBORING UPPER-LEVEL-JET N. THERE DOES SEEM TO BE SOME LEVEL OF DIFFLUENCE TO SUPPORT DEEP-LAYER LIFT AND UPSLOPING-OVERRUNNING MOISTURE. THE TIMING MAYBE PERHAPS OFF SUCH THAT TROPICAL REMNANTS OF BILL MAY BE LIMITED IN THEIR REACH N. PERHAPS NOT. THIS IN ADDITION THAT BETWEEN TWO AREAS OF ASCENT THERE HAS TO BE AN AREA OF DESCENT/SINKING AIR. THERE HAS BEEN SOMEWHAT A CONSISTENT SIGNAL OF SOMEWHERE ACROSS THE NE-CONUS OF LITTLE IF ANY IMPACT BETWEEN THE UNPHASED DISTURBANCES. SOME UNCERTAINTIES TO PONDER...BUT NEVERTHELESS WILL KEEP WITH A WET FORECAST FOR SUNDAY AS THE REMNANTS OF TS BILL SLIDE S AND A COLD FRONT SWEEPS THROUGH FROM THE N AND W TOWARDS MONDAY MORNING. WILL MAINTAIN HIGHER POPS ALONG THE S-HALF OF S NEW ENGLAND. MAIN THREAT IS HEAVY RAIN WITH LESSER CHANCES OF THUNDER. BUT THIS COULD BE A SWING AND A MISS PER THE 19.0Z GFS AND ECMWF. THEREAFTER...NOT LOOKING SUMMER-LIKE. MID-LEVEL ENERGY THROUGH THE ZONAL-FLOW REGIME IS SHUNTED S GRADUALLY BY A POLAR-ORIGIN WAVE OUT OF THE HUDSON BAY REGION SWEEPING +8-10C H85 AIR ACROSS THE REGION. SO AN INITIAL IMPULSE OF WET-WEATHER ASSOCIATED WITH A WEAK-SYNOPTIC LOW IS ANTICIPATED MONDAY NIGHT. WILL GO WITH CHANCE POPS AND JUST SHOWERS. COULD SEE RENEWED ACTIVITY TUESDAY WITH THE ENVIRONMENT DESTABILIZING MAINLY ACROSS THE N AND W INTERIOR PRIOR TO A STRONG COLD FRONT DIGGING S PUSHING THE BETTER MOIST-CONVERGENT FLOW REGIME W TO E ACROSS THE MID-ATLANTIC TEMPERATURES. LOOKING AT BELOW-NORMAL TEMPERATURES AND DRY CONDITIONS WEDNESDAY - THURSDAY. IN THE END COULD PERHAPS SEE A CHILLY MONTH OF JUNE OF WHICH TEMPS PRESENTLY ARE AVERAGING 3 DEGREES BELOW-NORMAL THROUGH THE 18TH. AS THE POLAR-WAVE RETREATS BACK N TOWARDS THE END OF THE WEEK WILL SEE THE RETURN OF WARMER AIR AND AN ACTIVE WEATHER PATTERN PER A CONSENSUS OF FORECAST GUIDANCE. && .AVIATION /07Z FRIDAY THROUGH TUESDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH SATURDAY/... THROUGH 12Z...WIDESPREAD MVFR CIGS WITH LOCALIZED IFR POSSIBLE ACROSS CT AND WESTERN MA. WIDELY SCT SHOWERS. TODAY...MODERATE CONFIDENCE. EARLY IFR/MVFR CONDITIONS QUICKLY ERODES AND LIFTS TO VFR BY 15Z OR SO. THEN HAVE TO WATCH POTENTIAL FOR RENEWED SHOWER/T-STORM DEVELOPMENT MAINLY FOCUSED OVER RI AND SE MA AFT 18Z AS COLD FRONT GETS HUNG UP NEAR THE S COAST. CONFIDENCE IN TSTMS IS LOW. TONIGHT...HIGH CONFIDENCE. A LINGERING SHOWER POSSIBLE EARLY ALONG THE S COAST WITH THE FRONT...OTHERWISE VFR BUT PATCHY FOG POSSIBLE NEAR THE S COAST. SATURDAY...MODERATE CONFIDENCE. VFR CIGS. KBOS TERMINAL...MODERATE CONFIDENCE WITH RESPECT TO TIMING OF IMPROVING CONDITIONS TO VFR LATER THIS MORNING. A BRIEF SHOWER POSSIBLE THROUGH THIS MORNING. A WEAK SEABREEZE IS POSSIBLE THIS AFTERNOON BUT CONFIDENCE IS MODERATE. KBDL TERMINAL...MODERATE CONFIDENCE WITH RESPECT TO TIMING OF IMPROVING CONDITIONS TO VFR LATER THIS MORNING. A BRIEF SHOWER POSSIBLE THIS MORNING. OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY... SATURDAY NIGHT INTO MONDAY MORNING...MODERATE CONFIDENCE. MVFR / IFR ASSOC REMNANTS OF TS BILL. WIDESPREAD SHRA. POSSIBLE +RA ALONG THE S-COAST. POTENTIAL VSBY IMPACTS. S-WINDS WITH GUSTS UP TO 20 KTS ASSOC WITH TS BILL BACKING NW WITH A COLD FRONTAL PASSAGE PUSHING REMNANTS OUT TO SEA. MONDAY INTO TUESDAY NIGHT...MODERATE CONFIDENCE. PERIODS OF -SHRA. LOW-END VFR. W/NW-WINDS. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH SATURDAY/...HIGH CONFIDENCE. TODAY...SW WINDS BECOMING LIGHT THEN LOCALLY EAST ACROSS E MA WATERS AS WEAK SEABREEZES DEVELOP. WINDS REMAINING SW OVER S COASTAL WATERS. A FEW SHOWERS POSSIBLE IN THE MORNING. TONIGHT...LIGHT NE WINDS BEHIND THE FRONT. ANY EVENING SHOWERS FOCUSED IN THE RI WATERS TO MVY/ACK AND SOUTH OF NEW ENGLAND WATERS. SATURDAY...WINDS TURNING SE WITH A FEW GUSTS TO 20 KT DEVELOPING. SEAS REMAINING BELOW SCA THRESHOLDS. OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY SATURDAY NIGHT INTO MONDAY MORNING...MODERATE CONFIDENCE. REMNANTS OF TS BILL. WIDESPREAD RAIN WITH EMBEDDED HEAVIER SHOWERS ESP OVER THE S-WATERS. ANTICIPATING VISIBILITY IMPACTS. POSSIBLE FOG. S-WINDS WITH GUSTS UP TO 20 KTS ASSOC WITH TS BILL BACKING NW WITH A COLD FRONTAL PASSAGE PUSHING REMNANTS OUT TO SEA. SEAS BUILDING IN EXCESS OF 5-FEET ON THE S/SE-WATERS. MONDAY INTO TUESDAY NIGHT...MODERATE CONFIDENCE. LIGHTER W/NW-WINDS. SEAS FALLING BELOW 5-FEET. PERIODS OF SHOWERS. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...KJC/SIPPRELL NEAR TERM...KJC SHORT TERM...KJC LONG TERM...SIPPRELL AVIATION...KJC/SIPPRELL MARINE...KJC/SIPPRELL
AREA FORECAST DISCUSSION
NWS ALBANY NY
143 AM EDT FRI JUN 19 2015 .SYNOPSIS... A COLD FRONT WILL MOVE ACROSS EASTERN NEW YORK AND WESTERN NEW ENGLAND WITH SCATTERED SHOWERS AND ISOLATED TO SCATTERED THUNDERSTORMS. THE COLD FRONT WILL MOVE SOUTH OF THE REGION TOMORROW MORNING WITH HIGH PRESSURE BUILDING IN FROM THE GREAT LAKES REGION. COOLER AND DRIER WEATHER WILL CONTINUE INTO THE FIRST HALF OF THE WEEKEND...AS WET AND UNSETTLED WEATHER RETURNS SATURDAY NIGHT INTO SUNDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1040 PM EDT...A PROGRESSIVE AND DIGGING UPPER LEVEL TROUGH OVER S-CNTRL ONTARIO INTO QUEBEC WITH THE CLOSED H500 CIRCULATION OVER NORTHERN QUEBEC WILL BREAK DOWN THE ZONAL FLOW ALOFT BRIEFLY TONIGHT INTO TOMORROW. A COLD FRONT ON THE LEADING EDGE OF THE UPPER LEVEL TROUGH WILL BE MOVING ACROSS THE REGION OVERNIGHT. LATEST KENX AND REGIONAL MOSAIC RADAR IMAGERY SHOWS A BAND OF HEAVY RAIN SHOWERS OVER THE WESTERN ADIRONDACKS. THERE HAVE BEEN A FEW RUMBLES OF THUNDER THANKS TO CLOUD-TO-CLOUD OR INTRA-CLOUD LTG ACTIVITY OVER OUR AREA ACCORDING TO NATL LTG NETWORK DATA...BUT ANY CLOUD TO GROUND STRIKES HAVE BEEN REMAINING WEST OF OUR AREA OVER THE TUG HILL FROM EARLIER THIS EVENING. RADAR TRENDS AND 3KM HRRR GUIDANCE SHOWS THIS BATCH OF SHOWERS AND STORMS WILL CONTINUE TO SLIDE EASTWARD TOWARDS THE LAKE GEORGE REGION...WITH MORE ACTIVITY SPREADING INTO THE MOHAWK VALLEY AND SARATOGA REGION REGION AS WELL...OVER THE NEXT SEVERAL HOURS. HAVE CONTINUED TO GO WITH LIKELY POPS OVER THIS AREA THROUGH MUCH OF THE NIGHT...BUT WILL CONTINUE TO ONLY CALL THUNDER SLIGHT CHANCE DUE TO SPORADIC AND SPARSE NATURE OF THE LTG DUE TO THE LIMITED INSTABILITY IN PLACE. ANY SHOWER/THUNDERSTORM WILL BE CAPABLE OF A BRIEF HEAVY DOWNPOUR...BUT HEAVY RAIN WILL BE SHORT LIVED IN ANY ONE LOCATION...AND FLOODING WON/T BE A CONCERN. FURTHER SOUTH...WILL CONTINUE TO GO WITH MAINLY CHC POPS. THE 3KM HRRR CONTINUES TO SHOW SOME SPOTTY ACTIVITY MOVING THROUGH THE CAPITAL REGION AND POINTS FURTHER SOUTH THROUGH THE LATE NIGHT HOURS AS THE FRONTAL BOUNDARY GETS CLOSER...BUT THE MOST CONCENTRATED SHOWERS/STORMS LOOKS TO REMAIN FURTHER NORTH. LOWS TONIGHT WERE FAVORED TOWARDS THE WARMER SIDE OF THE GUIDANCE WITH THE SLOW TIMING OF THE COLD FRONT. LOWS IN THE MID TO U50S ARE LIKELY OVER THE MTNS...WITH MAINLY LOWER TO M60S IN THE VALLEY AREAS. && .SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY NIGHT/... TOMORROW...COMPARED TO YESTERDAY AFTERNOON...THE CONSENSUS WITH THE SHORT-RANGE GUIDANCE IS A SLOWER TREND WITH THE PASSAGE OF THE SFC COLD FRONT...ITS ASSOCIATED DEWPT BOUNDARY...AND THE UPPER TROUGH AXIS. THE NAM SEEMS TO BE THE SLOWEST...WITH THE GFS/ECMWF A BIT FASTER. A SLIGHT OR LOW CHC OF SHOWERS WAS KEPT IN THE FCST FROM THE MOHAWK VALLEY/CAPITAL REGION/GLENS FALLS/SARATOGA REGION/SRN VT SOUTH AND EAST IN THE MORNING. THE LATER TIMING WILL ALLOW SLIGHTLY WARMER MAX TEMPS WITH THE W/NW DOWNSLOPING WINDS IN THE WAKE OF THE BOUNDARY ALLOWING SOME COMPRESSIONAL WARMING...ESPECIALLY IN THE CAPITAL DISTRICT AND MID HUDSON VALLEY. THE SFC HIGH WILL BE QUICKLY BUILDING IN FROM THE GREAT LAKES REGION...AND THE SKIES SHOULD CLEAR IN THE AFTERNOON FROM THE N/NW TO S/SE DUE TO THE STRONG SUBSIDENCE IN THE WAKE OF THE FRONT...AND WITH THE APPROACHING ANTICYCLONE. IT WILL BE A BREEZY AFTERNOON DUE TO THE RELATIVELY STRONG SFC PRESSURE GRADIENT BETWEEN THE SYSTEMS...AND BETTER MIXING FROM ALOFT. HIGHS WILL BE IN THE LOWER TO ISOLATED M80S FROM THE SRN REACHES OF THE CAPITAL DISTRICT INTO THE MID HUDSON VALLEY...SRN TACONICS IN THE PORTIONS OF LITCHFIELD CTY CT...MID AND U70S WILL BE COMMON IN MANY OF THE OTHER VALLEY LOCATIONS AND OVER THE HILLS...WITH M60S TO M70S OVER THE MTNS. THE WINDS WILL BE FROM THE NW/N AT 10 TO 20 MPH WITH SOME GUSTS AROUND 25 TO 30 MPH. TOMORROW NIGHT...A CLEAR/MOSTLY CLEAR NIGHT IS EXPECTED WITH DIMINISHING WINDS THAT BECOME LIGHT TO CALM...AS THE SFC HIGH MOVES OVERHEARD. IT IS A VERY COOL CANADIAN AIR MASS. H850 TEMPS WILL BE IN THE +7C TO +10C RANGE. IDEAL RADIATIONAL COOLING CONDITIONS WILL ALLOW TEMPS TO FALL INTO THE U40S TO M50S FROM THE CAPITAL REGION/MOHAWK VALLEY SOUTH AND EAST...AND MAINLY 40-45F NORTH OF ALBANY WITH A FEW U30S OVER THE SRN DACKS. SATURDAY...A NICE START TO THE WEEKEND IS EXPECTED WITH THE SFC HIGH MOVING EAST OF NEW ENGLAND DURING THE AFTERNOON. SUNNY/MOSTLY SUNNY SKIES WILL GIVE WAY TO INCREASING MID AND HIGH CLOUDS FROM THE SOUTH AND WEST IN ADVANCE OF A WARM FRONT OVER THE OH VALLEY AND MID ATLANTIC SATES. THE REMNANT CIRCULATION FROM BILL WILL ALSO APPROACH THE OH VALLEY. A FEW SHOWERS MAY POP UP LATE IN THE DAY OVER THE CATSKILLS AND BERKSHIRES. OTHERWISE FAIR AND DRY CONDITIONS ARE EXPECTED FOR MOST OF THE AREA WITH HIGHS MAINLY IN THE MID AND U70S IN THE LOWER ELEVATIONS...AND M60S TO L70S OVER THE MTNS. SATURDAY NIGHT...THE GFS AND ECMWF HAVE TRENDED FASTER WITH THE WARM FRONT LIFTING N/NE FROM THE MID ATLANTIC REGION...AND A SFC WAVE AND COLD FRONT APPROACHING FROM THE GREAT LAKES REGION. THE TROUGH THAT WAS FORMERLY BILL LOOKS TO STAY SOUTH OF THE REGION. THE INCREASING MOISTURE TRANSPORT AND THETA-E ADVECTION AHEAD OF THE WARM FRONT WILL ALLOW SHOWERS AND SCT THUNDERSTORMS TO INCREASE. THE SHOWALTER VALUES LOWER TO 0C TO -2C. THE PWATS LOOKS TO INCREASE TO 1.25-1.75 INCHES. HIGH CHC AND LIKELY POPS ARE IN THE GRIDS WITH CHC OF THUNDERSTORMS AFTER MIDNIGHT. SOME LOCALLY HEAVY RAINFALL IS POSSIBLE AND WILL MENTION IN THE HWO. THE GREATEST THREAT LOOKS TO BE ON SUNDAY. && .LONG TERM /SUNDAY THROUGH THURSDAY/... THE START OF THE EXTENDED PERIOD WILL BE RATHER ACTIVE...AS THE REMNANTS OF TC BILL WILL BE PASSING BY THE SOUTH OF THE REGION ON SUNDAY. THE CONSENSUS OF THE 12Z DETERMINISTIC MODEL GUIDANCE...AS WELL AS MANY OF THE 12Z GEFS MEMBERS...SHOWS THE REMNANT SFC LOW AND HEAVIEST QPF ASSOCIATED WITH BILL MAINLY SOUTH OF THE REGION. STILL...WITH PWAT VALUES AS HIGH AS 2-3 STD ABOVE NORMAL...ANY SHOWER OR T-STORM OVER THE REGION WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY DOWNPOURS. THERE LOOKS TO BE ENOUGH LIFT FOR SHOWERS OVER MUCH OF THE REGION...AS AN APPROACHING NORTHERN STREAM SHORTWAVE WILL TEAM UP WITH THE REMNANT TC CIRCULATION TO ALLOW FOR WIDESPREAD SHOWERS/T-STORMS. T-STORM ACTIVITY DOES/T APPEAR TO BE TOO STRONG DUE TO LIMITED INSTABILITY DUE TO PERSISTENT CLOUD COVER AND WARM MID LEVEL TEMPS. TEMPS ON SUNDAY WILL BE HELD DOWN MAINLY INTO THE 70S THANKS TO THE PRECIP/CLOUDS. ALTHOUGH THE BEST CHC FOR SHOWERS/TSTMS LOOKS TO BE ON SUNDAY...THERE MAY BE A FEW LINGERING SHOWERS INTO SUNDAY NIGHT OR MONDAY THANKS TO THE PASSING UPPER LEVEL TROUGH. TEMPS LOOK TO HOLD IN THE 60S FOR SUN NIGHT...AND MID 70S TO LOW 80S FOR MONDAY...WITH MORE BREAKS OF SUNSHINE EXPECTED AS THE BEST UPPER LEVEL ENERGY STARTS TO MOVE AWAY. A BRIEF BREAK IN THE WEATHER IS EXPECTED FOR MONDAY NIGHT...BEFORE YET ANOTHER NORTHERN STREAM SHORTWAVE IMPACTS THE REGION FOR TUESDAY INTO TUESDAY EVENING. THIS SYSTEM WILL ALLOW FOR A CHANCE OF SHOWERS OR THUNDERSTORMS...WITH THE BEST CHC FOR THUNDER DURING TUESDAY AFTN/EVE. TEMPS ON MON NIGHT WILL BE IN THE MID 50S TO LOW 60S...AND HIGHS ON TUESDAY WILL PROBABLY BE IN THE MID 70S TO NEAR 80. BEHIND THE STORM/S COLD FRONT...COOLER AND LESS HUMID AIR WILL START WORKING TO THE AREA FOR TUESDAY NIGHT AND THROUGH THE REMAINDER OF THE LONG TERM PERIOD. SKIES WILL START TO CLEAR OUT TUESDAY NIGHT...WITH LOWS LATE ON TUESDAY NIGHT IN THE 50S. DRY WEATHER WITH A PARTLY TO MOSTLY SUNNY SKY IS EXPECTED ON WEDNESDAY AND THURSDAY WITH HIGHS WELL INTO THE 70S TO NEAR 80. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... MAINLY MVFR CONDITIONS EXPECTED THROUGH 12Z...THEN VFR THEREAFTER. A COLD FRONT MOVING THROUGH OVERNIGHT WILL PRODUCE SCATTERED SHOWERS. RADARS INDICATED A LITTLE MORE ACTIVITY REGARDING SCATTERED SHOWERS WORKING INTO THE TAF SITES. THERE WAS AN EARLIER LIGHTNING STRIKE OR TWO ASSOCIATED WITH CONVECTION JUST NORTH OF KGFL. AS OF 540Z...THERE HAD BEEN NONE IN THE BETTER PART OF AN HOUR. EXPECT OCCASIONAL IFR CIGS TONIGHT DUE BUT PREVAILING LOW MVFR (EXTRA FUEL REQUIRED) THROUGH THE MORNING PEAK AT ALL THE TAF SITES. VISIBILITY WILL BE MAINLY VFR BUT OCCASIONAL DOWN TO MVFR IN SHOWERS AND MIST. THE WIND WHICH HAS BEEN MAINLY SOUTHERLY...WILL CONTINUE TO DO SO THROUGH ABOUT 10Z...THEN SHIFT TO THE W/NW AND THEN EVENTUALLY NORTH THROUGH THE MORNING HOURS AFTER THE MORNING PEAK. THEY WILL AVERAGE AROUND 10KTS...GUSTING UP TO 20KTS BY MIDDAY AT KPSF AND KALB. CLOUDS WILL LIFT BACK TO VFR AFTER 12Z...THEN EVENTUALLY BECOME SCATTERED (EXCEPT AT KPOU WHERE A BKN CIG IS LIKELY MUCH OF THE DAY BUT AGAIN AT 4500 KFT). BY THIS EVENING...EXPECT A CLEAR SKY UNRESTRICTED VISIBILITY AND LIGHT WIND. THERE MIGHT BE SOME PATCHY FOG FORMING OVERNIGHT AND WE WILL ADDRESS THAT POSSIBILITY MORE IN THE 12Z TAF ISSUANCE. OUTLOOK... FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY NIGHT: MODERATE OPERATIONAL IMPACT. LIKELY SHRA...TSRA. SUNDAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA. SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. MONDAY: NO OPERATIONAL IMPACT. NO SIG WX. MONDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...TSRA. TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. && .FIRE WEATHER... A COLD FRONT WILL MOVE ACROSS EASTERN NEW YORK AND WESTERN NEW ENGLAND WITH SCATTERED SHOWERS AND ISOLATED TO SCATTERED THUNDERSTORMS. COOLER AND DRIER WEATHER WILL CONTINUE FRIDAY AFTERNOON INTO THE FIRST HALF OF THE WEEKEND...AS WET AND UNSETTLED WEATHER RETURNS SATURDAY NIGHT INTO SUNDAY. THE RELATIVE HUMIDITY VALUES RECOVER TO 90 TO 100 PERCENT TONIGHT AND DECREASE TO 25 TO 45 PERCENT TOMORROW AFTERNOON. THE RH VALUES RECOVER TO 75 TO 100 PERCENT SATURDAY MORNING. THE WINDS WILL BE FROM THE SOUTH TO SOUTHEAST AT 5-15 MPH LATE THIS AFTERNOON INTO EARLY THIS EVENING...AND WILL SHIFT TO THE W TO NW AT 5 TO 15 MPH TOMORROW MORNING WITH THE COLD FRONTAL PASSAGE. THE WINDS WILL SHIFT TO THE NORTHWEST TO NORTH AT 10 TO 20 MPH WITH SOME GUSTS TO 25 TO 30 MPH TOMORROW IN THE LATE MORNING INTO THE AFTERNOON. && .HYDROLOGY... NO HYDRO PROBLEMS ARE EXPECTED INTO THE FIRST HALF OF THE WEEKEND...BUT SOME RISES ARE POSSIBLE ON THE MAIN STEM RIVERS SATURDAY NIGHT THROUGH SUNDAY...AS SOME WIDESPREAD RAINFALL RETURNS. SCATTERED SHOWERS AND ISOLATED TO SCATTERED THUNDERSTORMS...SOME WITH LOCALLY HEAVY RAINFALL...WILL MOVE BACK INTO THE REGION TONIGHT AS THE NEXT COLD FRONT MOVES THROUGH. RAINFALL AMOUNTS WILL RANGE FROM ONE TENTH TO A THIRD AN INCH WITH SOME LOCALLY HIGHER AMOUNTS. DRY WEATHER IS EXPECTED FRIDAY INTO SATURDAY AS HIGH PRESSURE BUILDS INTO THE REGION. WET WEATHER IS EXPECTED TO RETURN FOR THE 2ND HALF OF THE WEEKEND INTO EARLY MONDAY...AS THE MOISTURE FROM TROPICAL ENTITY BILL MAY IMPACT PARTS OF THE HYDRO SERVICE AREA. RAINFALL AMOUNTS ARE VARIABLE RIGHT NOW...BUT A WIDESPREAD HALF AN INCH AN INCH IS LIKELY WITH LOCALLY HIGHER AMOUNTS WITH THE HEAVIER SHOWERS AND THUNDERSTORMS. 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...WASULA NEAR TERM...FRUGIS/WASULA SHORT TERM...WASULA LONG TERM...FRUGIS AVIATION...HWJIV FIRE WEATHER...BGM/WASULA HYDROLOGY...BGM/WASULA
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
429 AM EDT FRI JUN 19 2015 .SYNOPSIS... A COLD FRONT WILL CROSS THE FORECAST AREA TODAY AND THEN STALL JUST TO OUR SOUTH. HIGH PRESSURE WILL BUILD IN TONIGHT AND THEN MOVE EAST SATURDAY. THE FRONT TO THE SOUTH WILL THEN MOVE BACK NORTH AS A WARM FRONT LATER ON SATURDAY. THE REMNANTS OF TROPICAL DEPRESSION BILL WILL MOVE THROUGH OUR REGION ON SUNDAY...WITH ANOTHER SERIES OF FRONTS EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A CDFNT WILL CROSS THE REGION TODAY AND HIGH PRES WILL BUILD TO THE N AND SLOWLY MOVE SWD. THE CDFNT WILL STALL JUST TO OUR S. LTST STLT IMAGERY SHOWED AN AREA OF RAIN, WITH SOME EMBEDDED THUNDER MOVG ACRS SERN PA AND JUST MOVG INTO SRN NJ ERLY THIS MRNG. A WEAKENING SMALLER AREA WAS MOVG ACRS DE AND MD. SOME ADDITIONAL SHWRS WERE IMPACTING NWRN AREAS. THESE WERE ASSOCD WITH A S/WV MOVG THRU. HRRR INDICATES THAT THINGS SHUD SETTLE DOWN LATER THIS MRNG AS THIS PRECIP MOVES THRU. THERE IS SOME DISAGREEMENT WITHIN THE MDLS WRT PRECIP CHCS TODAY. WITH THE FRONT STALLING TO THE S, IT WOULD SEEM THAT IS WHERE THE BEST CHCS WOULD BE. THE GFS AND WPC GUID IS ESSENTIALLY DRY. THEY OTHER MDLS HAVE AT LEAST SOME CHC OF PRECIP SOMEWHERE IN THE CWA DURG THE COURSE OF THE DAY. FOR NOW, WILL GO WITH A GENLY DRY FCST AFTER THIS MRNG, BUT SOME PRECIP CAN NOT BE RULED OUT LATER IN THE DAY. THE WIND SHUD BECOME MORE W TO NW WHICH WOULD ALSO FAVOR A DRIER SOLN. HIGH TEMPS LOOK TO BE IN THE MID/UPPER 80S. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/... THE AFOREMENTIONED HIGH WILL MOVE EWD OVER NEW ENG TONIGHT AND A DRY FCST IS ANTICIPATED. WIND WILL BECOME MORE NELY DUE TO THE POSN OF THE HIGH. THERE IS BETTER MDL AGREEMENT ON THE TONIGHT FCST. && .LONG TERM /SATURDAY THROUGH THURSDAY/... WE HAVE UPDATED THE GRIDS DURING THE OVERNIGHT EXTENDED PACKAGE. WE DO NOT SEE MANY DRASTIC CHANGES FROM THE DAYTIME PACKAGE. A MOSTLY ZONAL FLOW IS EXPECTED ACROSS THE COUNTRY. A SUBTLE TROUGH MOVES ACROSS THE NORTHEAST EARLY NEXT WEEK THEN A WEAK RIDGE BUILDS LATE. THE WAVY FRONT IN THE NEAR/SHORT TERM NEVER MOVES TOO FAR AWAY. IT WILL MOVE BACK AND FORTH ACROSS THE AREA KEEPING A LARGELY UNSETTLED PATTERN. SAT...WEAK HIGH PRESSURE WITH MOSTLY DRY CONDITIONS. INCREASING CLOUDS LATE. A CHC FOR SHOWERS OVER THE DELMARVA DURING THE AFTERNOON. TEMPERATURES NEAR NORMAL. SAT NIGHT THRU EARLY SUNDAY NIGHT...HEAVY RAINS AND LOCALIZED FLOODING POSSIBLE WITH THE REMNANTS OF FORMER TS BILL MOVING ACROSS THE AREA. PWAT VALUES WILL BE ABNORMALLY HIGH AND WITH DECENT DYNAMICS AND A FRONT ACROSS THE AREA...ONE TO TWO INCHES OF RAIN MAY OCCUR. TEMPERATURES NEAR NORMAL...BUT ABOVE NORMAL FAR SOUTH. SUN NIGHT THRU MON...ANOTHER PERIOD OF MOSTLY DRY WEATHER AS HIGH PRESSURE MOVES ACROSS THE REGION. TEMPERATURES ABOVE NORMAL. MON NIGHT THRU THU...UNSETTLED WITH CHCS FOR SHOWERS/TSTMS MOSTLY DURING THE AFTERNOON/EARLY EVENING. TEMPS ABOVE NORMAL TUE...THEN NEAR NORMAL WED/THU. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. CONDS RANGED FROM LIFR TO VFR ERLY THIS AM, WITH MOST LOCATIONS SOMEWHERE IN THE IFR/MVFR RANGE. THERE WAS A SWATH OF RAIN WITH SOME EMBEDDED THUNDER MOVG ACRS S JERSEY AND ERN PA ATTM AND THUNDER WAS EARLIER REPORTED AT KPHL AND KILG. EXPECT LWR CONDS TO PREVAIL AT MOST SITES THRU THE MRNG HOURS BEFORE ALL SITES BECOME VFR BY AFTN. VFR CONDS SHUD THEN PREVAIL THRU TONIGHT AS HIGH PRES BUILDS TO THE N AND MOVES NE BY SAT MRNG. WIND WILL GENLY BE S TO SW AND BECOME MORE W TO NW AS THE DAY PROGRESSES AND WILL END UP MORE NELY TO E BY THE END OF THE TAF PD. WIND SPEEDS WILL REACH AROUND 12 KTS DURG THE AFTN, BUT WILL OTHERWISE BE LESS THAN 10 KTS THRU THE TAF PD. OUTLOOK... FRI NIGHT...MVFR POSSIBLE IN SHRA/TSRA EARLY...MAINLY ILG, ACY, AND MIV...OTHERWISE VFR. SAT...MAINLY VFR...EXCEPT MVFR POSSIBLE IN SHRA/TSRA...ESPECIALLY AT PHL, PNE, TTN, ILG, AND RDG. SUN...MVFR/IFR POSSIBLE IN LOW CLOUDS, FOG, +SHRA...ESP LATE AM THRU EARLY AFTN. MON THRU TUE...VFR CONDITIONS EXPECTED ATTM. && .MARINE... NO MARINE HEADLINES ARE EXPECTED THRU THE NEAR AND SHORT TERM PDS. OUTLOOK... SAT...HIGH PRES OVER THE WATERS WITH A LIGHT EASTERLY FLOW... SUB SCA CONDITIONS ARE EXPECTED. SUN AND SUN NIGHT...A SERIES OF FRONTS AND THE REMNANTS OF TS BILL WILL BE ACROSS THE WATERS. LOW END SCA GUSTS/SEAS POSSIBLE. MON/TUE...MOSTLY SUB-SCA CONDITIONS. SCT SHOWERS MON NIGHT/TUE. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...FRANCK/O`HARA NEAR TERM...NIERENBERG SHORT TERM...NIERENBERG LONG TERM...O`HARA AVIATION...FRANCK/NIERENBERG/O`HARA MARINE...FRANCK/NIERENBERG/O`HARA
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
950 AM EDT FRI JUN 19 2015 .DISCUSSION... CURRENT-THIS AFTERNOON...THE LATEST RAP SURFACE TO 500MB ANALYSES SHOWING THAT THE DEEP LAYER RIDGE REMAINS ANCHORED OVER THE FLORIDA PENINSULA. THE LOW SURFACE/LOW LEVEL RIDGE AXES WERE OVER THE SOUTHERN FORECAST AREA. THIS WILL RESULT IN SOUTH TO SOUTHEAST WINDS THE SOUTH HALF AND A SOUTH TO SOUTHWEST WIND FOR THE NORTHERN HALF OF THE FORECAST AREA. THE SOUTH TO SOUTHWEST WIND SHOULD DELAY THE ONSET OF THE SEA BREEZE IN NORTH BREVARD AND VOLUSIA COUNTIES. THIS WILL ALLOW TEMPERATURES TO GO A LITTLE HIGHER BEFORE THE SEA BREEZE COMES ASHORE. THE EARLIER SEA BREEZE TO THE SOUTH WILL ALLOW EARLIER SHOWER AND STORM FORMATION. TD BILL MOVING EASTWARD ACROSS MISSOURI AND KENTUCKY TODAY WILL KEEP THE LOW LEVEL RIDGE AXES TO THE SOUTH JUST ABOUT WHERE THEY ARE PRESENTLY BEING ANALYZED BY THE RAP MODEL. THE MORNING UPDATE WILL LOOK AT DELAYING THE ONSET OF THE AFTERNOON SEA BREEZES NORTH BREVARD AND VOLUSIA. THE RAP STEERING WINDS GO FROM THE WEST IN THE NORTHERN AREAS TO THE NORTH NORTHEAST FORT PIERCE SOUTH. DAYTONA MAY SEE STORMS APPROACHING FROM THE WEST AS THE SEA BREEZE STRUGGLES TO PUSH INLAND. WILL HAVE TO LOOK AT THE AFTERNOON WEATHER GRIDS AS WELL. .AVIATION... VFR CONDS GENERALLY EXPECTED THROUGH THE MORNING HOURS. RAIN CHANCES WILL BE HIGHER TODAY WITH ISOLATED TO SCATTERED SHOWERS AND STORMS DEVELOPING ALONG THE INLAND MOVING EAST COAST SEA BREEZE INTO THE AFT. GREATEST COVERAGE WILL REMAIN ACROSS THE INTERIOR WITH ANY BOUNDARY COLLISIONS LATER IN THE DAY. TEMPO IFR/MVFR CONDS WILL OCCUR WITH ANY OF THIS ACTIVITY INTO THE EVENING HOURS. VFR EXPECTED ALONG THE COAST MELBOURNE SOUTH ONCE THE SEA BREEZE PUSHES WEST OF INTERSTATE 95. .MARINE... CURRENT-THIS AFTERNOON...THE NOAA BUOYS/CMAN SITES WERE RECORDING SOUTHWEST TO WEST WINDS 5 TO 10 KNOTS AND 1 TO 2 FOOT SEAS. THE SURFACE RIDGE AXIS IS EXPECTED TO REMAIN OVER THE SOUTHERN COASTAL WATERS. SHOULD SEE AN EARLIER SEA BREEZE COMPONENT TO THE WIND OVER THE SOUTHERN AREAS THEN LATE AFTERNOON CAPE CANAVERAL NORTH. BOATERS SHOULD KEEP AN EYE TO THE SKIES...ESPECIALLY CAPE CANAVERAL NORTH...FOR WEST TO EAST MOVING STORMS LATER TODAY. PREVIOUS AFD TODAY/TONIGHT...RELATIVELY LIGHT LOW LEVEL WINDS WILL EXIST OVER THE AREA WITH ATL RIDGE TO THE EAST AND WEAK HIGH OVER THE EASTERN GULF. THIS WILL ALLOW A SEA BREEZE TO DEVELOP ALONG BOTH COASTS BY EARLY AFT...PUSHING INLAND THROUGH LATE DAY. OVERALL MOISTURE CONTINUES TO INCREASE WITH PW VALUES UP TO 1.9-2.0" WHICH WILL LEAD TO A GREATER CHANCE FOR SHOWERS AND STORMS IN THE AFTERNOON. HIGHEST COVERAGE WILL EXIST WITH BOUNDARY COLLISIONS INLAND LATER IN THE DAY AND TOWARD SUNSET...BUT EVEN COASTAL AREAS MAY SEE SOME RAIN ESPECIALLY AS THE SEA BREEZE INITIALLY FORMS. A FEW INLAND STRONG STORMS NOT OUT OF THE QUESTION WITH FREQUENT LIGHTNING...STRONG DOWNBURST WINDS AND LOCALLY HEAVY RAINFALL THE MAIN THREATS. EVEN WITH THE EXPECTED HIGHER COVERAGE OF SHOWERS AND STORMS...THERE SHOULD BE SUFFICIENT DAYTIME HEATING FOR HIGHS TO AGAIN REACH THE LOW 90S ALONG THE COAST AND MID 90S ACROSS THE INTERIOR. HEAT INDEX VALUES UP TO 100-105 ARE AGAIN EXPECTED THIS AFT BEFORE CONVECTION AND INCREASING CLOUD COVER BRING SOME RELIEF TO THE HOTTER TEMPS LATER IN THE DAY. CONVECTION WILL LINGER...MAINLY ACROSS THE INTERIOR...INTO THE EVENING WITH RAIN CHANCES FORECAST TO END BY MIDNIGHT. DEBRIS CLOUD COVER WILL GRADUALLY DECREASE WITH OVERNIGHT LOWS IN THE LOW TO MID 70S. SAT...AS THE REMNANTS OF BILL MOVE THROUGH THE TN VALLEY ON SATURDAY THE ATLC SFC RIDGE WILL REMAIN ACROSS CENTRAL TO S FL. 00Z NAM IS INDICATING A BIT MORE WESTERLY LOW LVL FLOW THAN THE GFS AS THE SFC RIDGE SLIPS SLOWLY SOUTH. BOTH MODELS INDICATE MORE THAN ADEQUATE MOISTURE LVLS FROM 1.8 TO 2.0 INCHES IN THE MORNING WHICH LEAD TO SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS MOST PREVALENT ACROSS THE INTERIOR IN THE LATE AFTERNOON AS THE EAST AND WEST COAST SEA BREEZES PUSH INTO THE INTERIOR. WILL TAPER POPS FROM 20 PCT IMMEDIATE TREASURE COAST TO 50 PCT ACROSS THE NRN INTERIOR INCLUDING METRO ORLANDO WHERE THERE COULD BE A FEW STRONG LATE AFTERNOON STORMS. HIGHS AROUND 90/LWR 90S COASTAL TO MID 90S FOR THE INTERIOR. SAT NIGHT....SCATTERED EVENING CONVECTION EXPECTED ALONG THE I-4 CORRIDOR INTO THE EVENING BEFORE DIMINISHING. LOWS IN THE 70S. SUNDAY...THE REMNANTS OF BILL WILL HAVE PASSED OFFSHORE FROM THE MID ATLC IN THE AFTERNOON WITH ATLC RIDGE ACROSS SRN COUNTIES. NAM STILL INDICATES THE SFC RIDGE WILL BE FURTHER SOUTH WITH MORE PREVALENT LOW LVL WESTERLY FLOW THAN THE GFS. FOR NOW WILL TREND TWD THE GFS WITH LOWER POPS S CSTL WHERE THE EAST COAST SEA BREEZE WILL PUSH INLAND. SHOULD SEE ANOTHER DAY WITH GOOD BOUNDARY INTERACTIONS ACROSS THE NRN INTERIOR AS SEA BREEZES MOVE INLAND. WILL FCST 40-50 PCT FROM OSCEOLA COUNTY INTO THE NRN INTERIOR INCLUDING METRO ORLANDO. HIGHS AGAIN IN THE LWR 90S CSTL TO MID 90S INTERIOR. MON-FRI...IT APPEARS THE MID LVL RIDGE WILL RE-ESTABLISH ITSELF ACROSS THE SE STATES FOR MUCH OF THE UPCOMING WEEK RETURNING MID LAYER FLOW FROM THE EAST WITH THE ATLC RIDGE EXTENDING ACROSS EAST CENTRAL FL INTO THE GULF. LOWEST RAIN CHANCES WILL REMAIN ACROSS THE TREASURE COAST BEACHES WITH HIGHER AFTERNOON THUNDERSTORM CHANCES ACROSS THE NRN INTERIOR EACH AFTERNOON. OVERALL INFLUENCE FROM THE MID LVL RIDGE TO THE NORTH SHOULD WILL REDUCE RAIN CHANCES TO NEAR 20 PCT ALONG CSTL SECTIONS TO AROUND 30 PCT ACROSS THE NRN INTERIOR. HIGHS WILL REMAIN ABOVE AVERAGE AROUND 90/LOWER 90S ALONG THE COAST AND 93-95 ACROSS THE INTERIOR WITH LOWS IN THE 70S. && .AVIATION...VFR CONDS GENERALLY EXPECTED THROUGH THE MORNING HOURS. RAIN CHANCES WILL BE HIGHER TODAY WITH ISOLATED TO SCATTERED SHOWERS AND STORMS DEVELOPING ALONG THE INLAND MOVING EAST COAST SEA BREEZE INTO THE AFT. GREATEST COVERAGE WILL REMAIN ACROSS THE INTERIOR WITH ANY BOUNDARY COLLISIONS LATER IN THE DAY. TEMPO IFR/MVFR CONDS WILL OCCUR WITH ANY OF THIS ACTIVITY INTO THE EVENING HOURS. && .MARINE... TODAY/TONIGHT...ATLC RIDGE JUST EAST OF THE AREA WILL MAINTAIN A SOUTHERLY FLOW ACROSS THE WATERS WITH SPEEDS LESS THAN 15 KNOTS. WINDS WILL BECOME SOUTHEAST NEAR THE COAST AS SEA BREEZE DEVELOPS AND MOVES INLAND THIS AFT. SEAS WILL RANGE FROM 1-3 FEET. SAT-SUN...WINDS AROUND THE ATLC RIDGE THIS WEEKEND WILL BE SOUTHERLY TO SOUTHEASTERLY ALONG THE COAST EACH AFTERNOON. WINDS MAINLY 5-10 KNOTS DURING DAYTIME PERIODS...STRONGER NEAR NEARSHORE WITH THE AFTERNOON SEA BREEZE. EXPECT A NOCTURNAL INCREASE TO 10-15 KNOTS EACH NIGHT. SEAS NEAR 2 FT AT THE COAST AND 2-3 FT OFFSHORE. THERE WILL BE A CHANCE OF LATE AFTERNOON AND EVENING STORMS MAINLY NORTH OF CAPE CANAVERAL OVER THE WEEKEND. MON-TUE...SOUTHERLY WINDS WILL CONTINUE INTO EARLY NEXT WEEK AROUND THE ATLC RIDGE WITH A SE SEA BREEZE CIRCULATION NEAR SHORE EACH AFTERNOON. SEAS SHOULD REMAIN 2-3 FT WITH MOST AFTERNOON SHOWERS AND THUNDERSTORMS FOCUSING INLAND AWAY FROM THE NEAR SHORE WATERS. && .PRELIMINARY POINT TEMPS/POPS... DAB 93 74 91 75 / 30 20 30 30 MCO 95 75 93 74 / 50 40 50 30 MLB 91 74 90 75 / 20 10 30 20 VRB 91 75 91 74 / 20 10 20 10 LEE 95 76 94 77 / 50 40 50 30 SFB 95 76 94 76 / 50 40 50 30 ORL 95 76 93 76 / 50 40 50 30 FPR 90 72 91 72 / 20 10 20 10 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ IMPACT WX/AVIATION...CRISTALDI FORECASTS...WIMMER
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1032 PM CDT SAT JUN 20 2015 .SHORT TERM... 329 PM CDT THROUGH TONIGHT... STILL LINGERING UNCERTAINTY REGARDING THE POTENTIAL FOR STRONG TO SEVERE STORMS THIS EVENING...WITH AN OVERALL TREND TOWARD A LOWER THREAT FOR THE THE NORTHEAST 1/2 TO 2/3 OF THE CWA. AS NOTED EARLIER...CLOUD COVER HAS OVERALL LIMITED DESTABILIZATION PROCESS EVEN IN PRESENCE OF GRADUALLY MOISTENING DEWPOINTS. ALSO A VERY STOUT WARM NOSE AT BASE OF EML ADVECTING WESTWARD CENTERED FROM 750-850 MB NOTED ON 18Z DVN SOUNDING WILL RESULT IN CAPPING/CINH AS DESTABILIZATION OCCURS LATE THIS AFTERNOON. ITS APPEARS THAT LINGERING CLUSTER OF THUNDERSTORMS OVER NORTHEAST IA AND NORTHWEST IL ON NOSE OF SPEED MAX SEEN ON W/V IMAGERY COULD BE MAIN FOCUS FOR WHAT OCCURS THIS EVENING...ONCE STRONGER FORCING ARRIVES AND WEAKENS THE CAP. IT STILL LOOKS THAT STRONGEST INSTABILITY AXIS WITH MLCAPE UP TO 1K TO 2K J/KG WILL RESIDE NEAR OR JUST WEST OF THE FAR WEST AND SOUTHWEST CWA. MORE ROBUST CONVECTION LIKELY WILL RIDE THIS NORTH- NORTHWEST TO SOUTH- SOUTHEAST AXIS THIS EVENING. THEREFORE...IN PRESENCE OF DEEP LAYER SHEAR OF 40-50 KT...HIGHEST POTENTIAL FOR SEVERE WEATHER IS FAVORED TO BE WEST OF DIXON TO OTTAWA TO PAXTON LINE...FAIRLY SIMILAR TO RECENT RUNS OF HRRR. UPSCALE GROWTH INTO MCS MAY BE OCCURRING BY TIME STORMS ARRIVE...SO PRIMARY THREATS FROM ANY SEVERE STORMS LOOK TO BE DAMAGING WIND GUSTS AND LARGE HAIL. FOR REST OF AREA...IT APPEARS BAND OF SHOWERS AND EMBEDDED STORMS WILL STILL PRESS SOUTHEAST AHEAD OF COLD FRONT AS DEPICTED ON RECENT HRRR RUNS...BUT WITH MUCH LOWER CHANCE FOR STRONG TO SEVERE THUNDERSTORMS. CLOUD TO GROUND LIGHTNING POTENTIAL MAY BE LIMITED BUT ALSO NON-ZERO FOR NORTHEAST ILLINOIS AND NORTHWEST INDIANA...SOMETHING TO KEEP IN MIND FOR OUTDOOR ACTIVITIES THIS EVENING. COULD END UP BEING MORE OF A SHOWER/EMBEDDED THUNDER SCENARIO. FINALLY...ANY ORGANIZED THUNDERSTORMS COULD PRODUCE HEAVY DOWNPOURS WITH HIGH PWAT IN 1.7 TO 1.8 INCH RANGE SAGGING SOUTHWARD AHEAD OF THE FRONT. THUS GIVEN RECENT HEAVY RAINS...WILL ALSO NEED TO MONITOR FOR FLOOD POTENTIAL THIS EVENING EVEN IN FASTER STORM MOTIONS. OVERNIGHT LOWS WILL BE IN THE UPPER 60S TO LOWER 70S...WITH 60S DEWPOINTS YIELDING MUGGY CONDITIONS. RC && .LONG TERM... 329 PM CDT SUNDAY THROUGH SATURDAY... MAIN FORECAST CONCERNS/CHALLENGES FOR THE PERIOD REMAIN WITH AN ACTIVE WEATHER PATTERN WITH PERIODIC CHANCES FOR SHOWERS/THUNDERSTORMS CONTINUING NEXT WEEK. THE PERIOD WILL BEGIN WITH FRONTAL BOUNDARY STILL LIKELY LINGERING ACROSS THE SOUTHERN THIRD OF THE CWA...WHERE UPPER 60S DEWPOINTS WILL STILL LIKELY RESIDE. WHILE CONVECTION FROM THE OVERNIGHT WILL HAVE LIKELY EXITED THE AREA BY THE MORNING...THERE APPEARS TO BE A CHANCE FOR FURTHER DEVELOPMENT ACROSS EAST CENTRAL ILLINOIS AND PORTIONS OF NORTHWEST INDIANA MAINLY SOUTH OF PONTIAC ILLINOIS TO MOROCCO INDIANA LINE. FORECAST SOUNDINGS IN THESE LOCATIONS ARE INDICATING INCREASING INSTABILITY WITH LITTLE TO NO CIN DURING THE MORNING AND ALTHOUGH THE CHANCE FOR ADDITIONAL DEVELOPMENT IS LOW...THERE DOES APPEAR TO BE A SMALL WINDOW BEFORE THE AXIS OF BEST DEVELOPMENT ALONG THIS BOUNDARY PUSHES SOUTH OF THE CWA BY MIDDAY. THE AFTERNOON WILL LIKELY BE DRY WITH CLEARING SKIES...AND WITH TEMPERATURES INCREASING INTO THE 80S. WINDS NEAR THE LAKE WILL BEGIN OUT OF THE NORTHWEST TO NORTH AND WITH A SHIFT TO THE NORTHEAST/EAST LIKELY BY MIDDAY...LIMITING TEMPS TO THE 70S. CONDITIONS APPEAR TO BE QUIET SUNDAY EVENING AND THROUGH MUCH OF SUNDAY NIGHT. HOWEVER...ATTENTION TURNS BACK WEST TOWARDS INCREASING MID LEVEL ENERGY AND A STRENGTHENING LLJ. THESE FEATURES WILL ALLOW FOR SHOWER/THUNDERSTORM DEVELOPMENT WELL WEST OF THE CWA ACROSS IOWA FOR MOST OF THE NIGHT. SOME OF THIS DEVELOPMENT COULD POSSIBLY REACH THE FAR WESTERN CWA LATE SUNDAY NIGHT INTO MONDAY MORNING AND HAVE MAINTAINED SLIGHT CHANCE WORDING DURING THIS TIME. THE BETTER CHANCES WILL COME MONDAY MORNING WHEN SCATTERED THUNDERSTORM DEVELOPMENT APPEARS POSSIBLE. VEERING LLJ...APPROACHING MID LEVEL SUPPORT...AND GOOD MOIST/TEMP ADVECTION SHOULD PROVIDE AMPLE SUPPORT FOR AT LEAST SCATTERED THUNDERSTORM DEVELOPMENT. WITH THIS DECENT FORCING IN PLACE AND WHILE MODERATE/STRONG INSTABILITY ALOFT QUICKLY LIFTS NORTH ACROSS THE CWA...COULD ALLOW FOR SOME OF THESE STORMS TO BE STRONG TO SEVERE. THE LIKELY HAZARD WOULD BE FOR LARGE HAIL...BEFORE THIS DEVELOPMENT LIFTS NORTH OF THE CWA BY MIDDAY. GUIDANCE DOES VARY TO HOW MONDAY AFTERNOON WILL EVOLVE WITH REGARD TO ADDITIONAL THUNDERSTORM DEVELOPMENT...BUT IT WOULD APPEAR THAT THERE WILL BE A DRY WINDOW DURING THIS TIME. PERSISTING WARM/MOIST PUSH RIDING ALONG STRONG SOUTH TO SOUTHWEST WINDS WILL BE OBSERVED MONDAY AND IF THE CLOUDS CAN DEPART...TEMPS IN THE MID TO UPPER 80S WILL BE LIKELY. ANOTHER DECENT CHANCE FOR THUNDERSTORM ARRIVING MONDAY NIGHT WITH THE POTENTIAL FOR SOME OF THEM TO BE STRONG TO SEVERE. HAVE NOT INCREASE POPS DURING THIS TIME TOO MUCH OWING TO SOME UNCERTAINTY WITH COVERAGE AND EXACT TIMING. HOWEVER...WITH A SURFACE TROUGH AND FRONT PUSHING THROUGH THE AREA...DEVELOPMENT DEFINITELY APPEARS POSSIBLE. THIS FRONT SHOULD PUSH THROUGH THE CWA BY TUESDAY BUT THERE IS A POSSIBILITY THAT IT COULD LINGER ACROSS THE SOUTHERN CWA DURING THIS TIME. IF IT DOES...THERE WILL BE ADDITIONAL CHANCES OVER THE SOUTHERN CWA. RODRIGUEZ && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 03Z... * SCATTERED SHRA/TSRA ENDING LATE THIS EVENING. * WIND DIRECTIONS THRU SUNDAY MORNING. * MVFR VIS/CIGS OVERNIGHT/SUNDAY MORNING. * GUSTY NORTHWEST/WEST WINDS SUNDAY. * POSSIBLE LAKE BREEZE/NORTHEAST WIND SHIFT LATE SUNDAY AFTERNOON/ EARLY EVENING. CMS //DISCUSSION...UPDATED 03Z... STILL LIGHT RAIN/SHOWERS ACROSS THE TERMINALS WITH SOME EMBEDDED THUNDER BUT THIS WILL BE ENDING OVER THE NEXT 1-2 HOURS AS IT SLOWLY PUSHES SOUTHEAST. WINDS HAVE BECOME VARIABLE BUT HAVE SOME EASTERLY COMPONENT. THESE WILL LIKELY REMAIN UNDER 10KTS OVERNIGHT AS THEY TURN BACK NORTHWEST OVERNIGHT. CMS PREVIOUS 00Z DISCUSSION... THUNDERSTORMS CONTINUE TO DEVELOP ACROSS NORTHWEST AND NORTH CENTRAL IL EARLY THIS EVENING. WHILE THESE STORMS WEAKEN AS THEY MOVE EAST...THEY ARE SLOWLY MOVING FURTHER EAST AND EVENTUALLY... EXPECT THUNDER TO REACH THE CHICAGO AREA TERMINALS BUT CONFIDENCE REGARDING TIMING AND COVERAGE IS STILL SOMEWHAT UNCERTAIN. TWEAKED TIMING WITH THE 00Z TAFS BUT EXPECT ADDITIONAL REFINEMENTS WILL BE NEEDED IN THE NEXT FEW HOURS. AHEAD OF THE STORMS...LIGHT RAIN OR SHOWERS WILL ALSO BE POSSIBLE. HOW LONG THIS ACTIVITY PERSISTS INTO THE LATE EVENING IS ALSO UNCERTAIN AS SHORT TERM GUIDANCE SUGGESTS ACTIVITY COULD CONTINUE THRU 05Z-06Z. OUTFLOW FROM THESE SHOWERS/STORMS HAS CAUSED THE WIND FIELD TO BECOME QUITE DISTURBED. GENERALLY WESTERLY WINDS WILL LIKELY BECOME VARIABLE OVER THE NEXT FEW HOURS...POSSIBLY SHIFTING LIGHT EASTERLY THIS EVENING. WINDS SHOULD TURN BACK NORTHWEST OVERNIGHT AND THEN BEGIN TO INCREASE SUNDAY MORNING...TURNING MORE WESTERLY BY THE AFTERNOON. THERE IS SOME POTENTIAL THAT AS THESE WINDS BEGIN TO DIMINISH LATER SUNDAY AFTERNOON...THAT A LAKE BREEZE MAY FORM AND INCLUDED A POSSIBLE LAKE BREEZE EARLY SUNDAY EVENING WITH THE 30 HOUR ORD TAF. WITH THE LIGHT WINDS AND MOIST LOW LEVELS...APPEARS MVFR CIGS AND VIS WILL BE POSSIBLE OVERNIGHT...POSSIBLY DIPPING TO IFR IN SOME LOCATIONS. ANY LOWER CIGS OR FOG THAT DEVELOP SHOULD QUICKLY LIFT AND IMPROVE AFTER SUNRISE. CMS //ORD AND MDW CONFIDENCE...UPDATED 03Z... * HIGH FOR SHRA/TSRA ENDING LATE THIS EVENING. * LOW FOR WIND DIRECTIONS OVERNIGHT...MEDIUM FOR WINDS OVERNIGHT/ SUNDAY. * HIGH FOR MVFR VIS/CIGS OVERNIGHT/SUNDAY MORNING...MEDIUM FOR TIMING. CMS //OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z... * MONDAY...CHANCE OF SHRA/TSRA. STRONG/GUSTY SOUTHWEST WINDS. * TUESDAY...DRY/VFR. NORTHEAST WINDS. * WEDNESDAY AND THURSDAY...CHANCE OF SHRA/TSRA. EASTERLY WINDS. * FRIDAY...SLIGHT CHANCE OF SHRA/TSRA. NORTHEAST WINDS. && .MARINE... 408 PM CDT THERE WAS A BRIEF PERIOD OF STRONGER WINDS EARLIER THIS AFTERNOON OVER THE SOUTHERN HALF OF THE LAKE...POSSIBLY UP TO 33 KT FOR A TIME. HOWEVER...WINDS HAVE SINCE DIMINISHED BACK TO THE 10 TO 15 KT RANGE IN THE NEAR TERM. THESE SPEEDS WITH GENERALLY SOUTHERLY FLOW WILL CONTINUE THIS EVENING AND INTO A PORTION OF THE OVERNIGHT...BEFORE A TROUGH AND FRONTAL BOUNDARY MOVE ACROSS THE REGION. THIS WILL ALLOW FOR A WIND SHIFT TO THE NORTHWEST AND ALTHOUGH THERE COULD BE A SMALL WINDOW OF 10 TO 20 KT WINDS WITH THIS WIND SHIFT...THE MORE PREVAILING SPEEDS WILL BE IN THE 10 TO 15 KT RANGE. NORTHERLY FLOW WILL REMAIN SUNDAY MORNING BUT DIMINISH AND THEN LIKELY BECOME MORE LIGHT AND VARIABLE THROUGH THE REMAINDER OF THE DAY. EXPECT WINDS TO SHIFT BACK MORE SOUTHERLY SUNDAY NIGHT INTO MONDAY...AND THEN INCREASE DURING THIS TIME. THIS INCREASE WILL ESPECIALLY OCCUR MONDAY AFTERNOON INTO THE EVENING...WHEN SOUTHERLY WINDS UP TO 30 KT ARE APPEARING LIKELY. THIS WILL PERSIST UNTIL ANOTHER SYSTEM MOVES THROUGH MONDAY NIGHT...WITH WINDS THEN EXPECTED TO TURN TO THE NORTHWEST WHILE DIMINISHING. 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/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
857 PM CDT SAT JUN 20 2015 .UPDATE... ISSUED AT 857 PM CDT SAT JUN 20 2015 A LINE OF STRONG TO SEVERE THUNDERSTORMS IS MOVING INTO WEST CENTRAL IL FROM THE NORTHWEST AHEAD OF A COLD FRONT MOVING SOUTHEASTWARD INTO THE AREA. SPC MESOANALYSIS SHOWING AROUND 4000 J/KG MLCAPE VALUES ALONG/SOUTH OF THE LINE WITH 30-50 KTS 0-6KM BULK SHEAR ACROSS NORTHERN HALF OF IL. AS A RESULT...ORGANIZED SEVERE CONVECTION SHOULD CONTINUE FOR MUCH OF THE EVENING THROUGH WEST CENTRAL IL AND A TORNADO WATCH REMAINS IN EFFECT UNTIL 11 PM. SEVERE WEATHER THREATS IN THIS AREA INCLUDE DAMAGING WIND GUSTS TO 60 MPH OR GREATER...LARGE HAIL...AND THE THREAT FOR AN ISOLATED TORNADO OR TWO. THUNDERSTORM ACTIVITY SHOULD SPREAD EAST AND SOUTH THROUGH CENTRAL/SE IL OVERNIGHT WITH SEVERE THUNDERSTORM THREAT SLOWLY DIMINISHING AND LARGELY SINKING SOUTHEASTWARD TOWARD SOUTH CENTRAL IL TOWARD POCKET OF STRONGEST INSTABILITY. HAVE SENT UPDATES TO FORECASTS FOR SHORT-TERM TRENDS IN THUNDERSTORM ACTIVITY LARGELY USING HRRR MODEL GUIDANCE WHICH APPEARS TO HAVE A GOOD HANDLE ON RECENT CONVECTIVE TRENDS. && .SHORT TERM...(TONIGHT) ISSUED AT 303 PM CDT SAT JUN 20 2015 THE REMNANTS OF TROPICAL STORM BILL DEFINED BY 1006 MB SURFACE LOW OVER SOUTHERN OHIO WITH 580 DM 500 MB LOW WILL TRACK INTO THE MID ATLANTIC STATES BY DAWN SUNDAY. BROKEN TO OVERCAST CLOUDS 1.5-3K FT OVER EASTERN HALF OF CWA WILL CONTINUE TO DECREASE FROM WEST TO EAST DURING LATE AFTERNOON AND EARLY EVENING. A CAPPED ATMOSPHERE IS KEEPING CENTRAL AND SOUTHEAST IL DRY SO FAR TODAY. HOWEVER, SHOWERS AND THUNDERSTORMS OVER EASTERN IA AND TRACKING EAST INTO NW IL AND SW WI MAINLY NORTH OF I-80 WILL EVOLVE INTO A LARGER MCS SYSTEM THAT WILL DROP SE TOWARD THE IL RIVER LATE THIS AFTERNOON/EARLY EVENING AND ACROSS MOST OF CENTRAL IL DURING THIS EVENING, REACHING SOUTHEAST IL OVERNIGHT WHERE CONVECTION CHANCES LOWER TO 30% FROM I-70 SOUTH. SPC HAS SLIGHT RISK OF SEVERE STORMS AS FAR SE AS A TAYLORVILLE TO DANVILLE LINE TONIGHT WHILE ENHANCED RISK WAS EXPANDED SE TO NEAR THE IL RIVER. AREAS WEST OF IL RIVER HAVE 30% RISK OF LARGE HAIL (2 INCH DIAMETER OR LARGER) AND DAMAGING WIND GUSTS ALONG WITH A 5% RISK OF TORNADOES. VERY UNSTABLE AIRMASS DEVELOPING LATE THIS AFTERNOON AND INTO THIS EVENING WITH CAPES RISING TO 2500-4500 J/KG IN WESTERN COUNTIES (EVEN NEAR 5000 J/KG BY 00Z/7 PM IN SW IA/NE MO AND FAR WEST CENTRAL IL AROUND QUINCY. MEANWHILE BULK SHEAR IS 30-40 KTS OVER NORTHERN CWA MAINLY FROM I-72 NORTH. PRECIPITABLE WATER VALUES OF 1.5-1.8 INCHES OVER IA THIS AFTERNOON TO SHIFT INTO CENTRAL IL THIS EVENING AND COULD CAUSE SOME LOCALLY HEAVY RAINS WITH THUNDERSTORMS ALONG WITH FREQUENT LIGHTNING. MUGGY LOWS TONIGHT IN THE LOWER 70S OVER CENTRAL/SE IL WITH UPPER 60S FAR NW BY GALESBURG. .LONG TERM...(SUNDAY THROUGH SATURDAY) ISSUED AT 303 PM CDT SAT JUN 20 2015 OUTFLOW BOUNDARY/FRONTAL BOUNDARY WILL REMAIN DRAPED OVER THE AREA TOMORROW AND THIS WILL BE THE FOCUS FOR ADDITIONAL SHOWERS AND THUNDERSTORMS. COULD BE SOME LINGERING THUNDERSTORMS FROM THE OVERNIGHT MCS THAT MOVES THROUGH. HOWEVER...BIG QUESTION IS HOW FAR SOUTH WILL THE OUTFLOW BOUNDARY GET BY MORNING. FORCING ALONG THE BOUNDARY AND MOISTURE WILL BE SUFFICIENT FOR MORE STORMS AND AGREE WITH SPC THAT A SLIGHT RISK IS WARRANTED OVER PARTS OF THE CWA TOMORROW THROUGH TOMORROW NIGHT. THIS BOUNDARY WILL THEN LIFT NORTHWARD A LITTLE THROUGH THE FIRST PART OF THE WEEK...SO PCPN CHANCES WILL SHIFT NORTHWARD SOME. HOWEVER...ALL MODELS FORECASTING STORMS TO CONTINUE THROUGH THE WEEK AND THIS WILL KEEP THE FRONT FROM GOING TOO FAR NORTH...AND WILL LIKELY BE OVER OR NEAR THE AREA THROUGH SATURDAY. THEREFORE...A CHANCE OF SHOWERS AND STORMS WILL CONTINUE THROUGH THE ENTIRE WEEK. THERE WILL BE SOME BREAKS IN THE PCPN...BUT TIMING OF WHEN THESE WILL BE THIS FAR OUT IS TOO UNCERTAIN. SO WILL JUST KEEP POPS THE WHOLE TIME AND THEN MAKE ADJUSTMENTS AS THE EVENTS GET CLOSER. TEMPS WILL BE WARM THROUGH THE PERIOD WITH THE WARMEST DAYS BEING MON THROUGH WED. A RELATIVELY STRONGER FRONT LOOKS TO MOVE THROUGH LATE IN THE WEEK AND THIS SHOULD BRING SLIGHTLY COOLER TEMPS FOR FRI AND SAT. GUIDANCE NUMBERS LOOK OK BUT WENT LITTLE WARMER IN THE EXTENDED THAN MEX GUIDANCE. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 656 PM CDT SAT JUN 20 2015 THE LINE OF STRONG TO SEVERE STORMS ACROSS EASTERN IOWA IS EVOLVING INTO A SQUALL LINE A LITTLE SOONER THAN EARLIER INDICATIONS. THERE REMAINS SOME CONVECTIVE INHIBITION IN THE LOWER LEVELS OF THE AIRMASS OVER CENTRAL ILLINOIS, BUT THE LINE OF STORMS SHOULD HAVE ENOUGH ELEVATED INSTABILITY AND MOMENTUM TO OVERCOME SOME OF THAT CIN. STORM STRENGTH MAY WEAKEN THE FARTHER THE LINE PROGRESSES INTO ILLINOIS, ALLOWING THE LINE TO SLOW DOWN AND STALL IN A WEST TO EAST ORIENTATION, DROPPING VERY HEAVY RAINFALL OVER SMALLER AREAS. THE PRIMARY SEVERE THREAT MAY TRANSITION FROM WIND AND HAIL TO FLASH FLOODING BY MIDNIGHT OR SHORTLY AFTER. PIA IS STILL UNDER THE GUN FOR DAMAGING WIND GUSTS OF 45-50KT AS THE LINE REACHES THEM BETWEEN 03Z-05Z/10PM- MIDNIGHT. WILL KEEP A TEMPO FOR THEM AND BMI AS THE STORM TRACK HAS A BETTER CHANCE OF REACHING THAT FAR E-SE. SPI, DEC, AND CMI WILL LIKELY SEE THE LATER STAGES OF THE COMPLEX ARRIVE AFTER MIDNIGHT, POSSIBLY AS LAST AS 3AM/08Z FOR CMI. HAVE SLOWED DOWN THE TIMING OF STORM ARRIVAL FOR ALL TAFS, AND INCREASED PEAK GUSTS IN THE TEMPO TO 45KT FOR PIA AND BMI. WE KEPT ONLY VCTS FOR THE OTHER TERMINAL SITES UNTIL THE EVOLUTION OF THE LINE BECOMES MORE APPARENT LATER THIS EVENING. WINDS WILL GENERALLY REMAIN SOUTH-SOUTHWEST AHEAD OF THE LINE OF STORMS, WITH SPEEDS OF 12-18KT. WINDS WILL THEN TRANSITION TO WEST LATE TONIGHT AND SUNDAY MORNING. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...ONTON SHORT TERM...07 LONG TERM...AUTEN AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
653 PM CDT SAT JUN 20 2015 .MESOSCALE DISCUSSION... 547 PM CDT SHORTWAVE/SPEED MAX NOTED ON W/V MOVING FROM EASTERN IA INTO NORTHWEST IL WEAKENED CAPPING ENOUGH OVER OUR AREA FOR THUNDERSTORMS TO SPREAD EASTWARD. EARLIER SEVERE WARNED STORM INITIALLY SHOWED A GOOD WIND SIGNATURE BUT QUICKLY WEAKENED AND IT APPEARS SEVERE THREAT FOR NEXT FEW HOURS WILL BE FAIRLY MINIMAL WITH THUNDERSTORMS OVER NORTHWEST CWA AND MORE OF A HEAVY RAIN THREAT. THIS IS DUE TO STRONG MOISTURE TRANSPORT INTO THIS AREA AND PWAT VALUES INCREASING TO UPWARDS OF 1.5 INCHES ACCORDING TO LATEST SPC MESOANALYSIS. MAIN SEVERE THREAT THIS EVENING WILL BE TIED TO EVOLUTION OF BROKEN LINE OF CONVECTION ACROSS EASTERN IOWA THAT MAY PASS NEAR OR JUST SOUTHWEST OF FAR WEST AND SOUTHWEST CWA. MAIN THREAT BY THIS TIME/8-10 PM CDT/WOULD BE DAMAGING WINDS AND ALSO SEVERE HAIL. RC && .SHORT TERM... 329 PM CDT THROUGH TONIGHT... STILL LINGERING UNCERTAINTY REGARDING THE POTENTIAL FOR STRONG TO SEVERE STORMS THIS EVENING...WITH AN OVERALL TREND TOWARD A LOWER THREAT FOR THE THE NORTHEAST 1/2 TO 2/3 OF THE CWA. AS NOTED EARLIER...CLOUD COVER HAS OVERALL LIMITED DESTABILIZATION PROCESS EVEN IN PRESENCE OF GRADUALLY MOISTENING DEWPOINTS. ALSO A VERY STOUT WARM NOSE AT BASE OF EML ADVECTING WESTWARD CENTERED FROM 750-850 MB NOTED ON 18Z DVN SOUNDING WILL RESULT IN CAPPING/CINH AS DESTABILIZATION OCCURS LATE THIS AFTERNOON. ITS APPEARS THAT LINGERING CLUSTER OF THUNDERSTORMS OVER NORTHEAST IA AND NORTHWEST IL ON NOSE OF SPEED MAX SEEN ON W/V IMAGERY COULD BE MAIN FOCUS FOR WHAT OCCURS THIS EVENING...ONCE STRONGER FORCING ARRIVES AND WEAKENS THE CAP. IT STILL LOOKS THAT STRONGEST INSTABILITY AXIS WITH MLCAPE UP TO 1K TO 2K J/KG WILL RESIDE NEAR OR JUST WEST OF THE FAR WEST AND SOUTHWEST CWA. MORE ROBUST CONVECTION LIKELY WILL RIDE THIS NORTH- NORTHWEST TO SOUTH- SOUTHEAST AXIS THIS EVENING. THEREFORE...IN PRESENCE OF DEEP LAYER SHEAR OF 40-50 KT...HIGHEST POTENTIAL FOR SEVERE WEATHER IS FAVORED TO BE WEST OF DIXON TO OTTAWA TO PAXTON LINE...FAIRLY SIMILAR TO RECENT RUNS OF HRRR. UPSCALE GROWTH INTO MCS MAY BE OCCURRING BY TIME STORMS ARRIVE...SO PRIMARY THREATS FROM ANY SEVERE STORMS LOOK TO BE DAMAGING WIND GUSTS AND LARGE HAIL. FOR REST OF AREA...IT APPEARS BAND OF SHOWERS AND EMBEDDED STORMS WILL STILL PRESS SOUTHEAST AHEAD OF COLD FRONT AS DEPICTED ON RECENT HRRR RUNS...BUT WITH MUCH LOWER CHANCE FOR STRONG TO SEVERE THUNDERSTORMS. CLOUD TO GROUND LIGHTNING POTENTIAL MAY BE LIMITED BUT ALSO NON-ZERO FOR NORTHEAST ILLINOIS AND NORTHWEST INDIANA...SOMETHING TO KEEP IN MIND FOR OUTDOOR ACTIVITIES THIS EVENING. COULD END UP BEING MORE OF A SHOWER/EMBEDDED THUNDER SCENARIO. FINALLY...ANY ORGANIZED THUNDERSTORMS COULD PRODUCE HEAVY DOWNPOURS WITH HIGH PWAT IN 1.7 TO 1.8 INCH RANGE SAGGING SOUTHWARD AHEAD OF THE FRONT. THUS GIVEN RECENT HEAVY RAINS...WILL ALSO NEED TO MONITOR FOR FLOOD POTENTIAL THIS EVENING EVEN IN FASTER STORM MOTIONS. OVERNIGHT LOWS WILL BE IN THE UPPER 60S TO LOWER 70S...WITH 60S DEWPOINTS YIELDING MUGGY CONDITIONS. RC && .LONG TERM... 329 PM CDT SUNDAY THROUGH SATURDAY... MAIN FORECAST CONCERNS/CHALLENGES FOR THE PERIOD REMAIN WITH AN ACTIVE WEATHER PATTERN WITH PERIODIC CHANCES FOR SHOWERS/THUNDERSTORMS CONTINUING NEXT WEEK. THE PERIOD WILL BEGIN WITH FRONTAL BOUNDARY STILL LIKELY LINGERING ACROSS THE SOUTHERN THIRD OF THE CWA...WHERE UPPER 60S DEWPOINTS WILL STILL LIKELY RESIDE. WHILE CONVECTION FROM THE OVERNIGHT WILL HAVE LIKELY EXITED THE AREA BY THE MORNING...THERE APPEARS TO BE A CHANCE FOR FURTHER DEVELOPMENT ACROSS EAST CENTRAL ILLINOIS AND PORTIONS OF NORTHWEST INDIANA MAINLY SOUTH OF PONTIAC ILLINOIS TO MOROCCO INDIANA LINE. FORECAST SOUNDINGS IN THESE LOCATIONS ARE INDICATING INCREASING INSTABILITY WITH LITTLE TO NO CIN DURING THE MORNING AND ALTHOUGH THE CHANCE FOR ADDITIONAL DEVELOPMENT IS LOW...THERE DOES APPEAR TO BE A SMALL WINDOW BEFORE THE AXIS OF BEST DEVELOPMENT ALONG THIS BOUNDARY PUSHES SOUTH OF THE CWA BY MIDDAY. THE AFTERNOON WILL LIKELY BE DRY WITH CLEARING SKIES...AND WITH TEMPERATURES INCREASING INTO THE 80S. WINDS NEAR THE LAKE WILL BEGIN OUT OF THE NORTHWEST TO NORTH AND WITH A SHIFT TO THE NORTHEAST/EAST LIKELY BY MIDDAY...LIMITING TEMPS TO THE 70S. CONDITIONS APPEAR TO BE QUIET SUNDAY EVENING AND THROUGH MUCH OF SUNDAY NIGHT. HOWEVER...ATTENTION TURNS BACK WEST TOWARDS INCREASING MID LEVEL ENERGY AND A STRENGTHENING LLJ. THESE FEATURES WILL ALLOW FOR SHOWER/THUNDERSTORM DEVELOPMENT WELL WEST OF THE CWA ACROSS IOWA FOR MOST OF THE NIGHT. SOME OF THIS DEVELOPMENT COULD POSSIBLY REACH THE FAR WESTERN CWA LATE SUNDAY NIGHT INTO MONDAY MORNING AND HAVE MAINTAINED SLIGHT CHANCE WORDING DURING THIS TIME. THE BETTER CHANCES WILL COME MONDAY MORNING WHEN SCATTERED THUNDERSTORM DEVELOPMENT APPEARS POSSIBLE. VEERING LLJ...APPROACHING MID LEVEL SUPPORT...AND GOOD MOIST/TEMP ADVECTION SHOULD PROVIDE AMPLE SUPPORT FOR AT LEAST SCATTERED THUNDERSTORM DEVELOPMENT. WITH THIS DECENT FORCING IN PLACE AND WHILE MODERATE/STRONG INSTABILITY ALOFT QUICKLY LIFTS NORTH ACROSS THE CWA...COULD ALLOW FOR SOME OF THESE STORMS TO BE STRONG TO SEVERE. THE LIKELY HAZARD WOULD BE FOR LARGE HAIL...BEFORE THIS DEVELOPMENT LIFTS NORTH OF THE CWA BY MIDDAY. GUIDANCE DOES VARY TO HOW MONDAY AFTERNOON WILL EVOLVE WITH REGARD TO ADDITIONAL THUNDERSTORM DEVELOPMENT...BUT IT WOULD APPEAR THAT THERE WILL BE A DRY WINDOW DURING THIS TIME. PERSISTING WARM/MOIST PUSH RIDING ALONG STRONG SOUTH TO SOUTHWEST WINDS WILL BE OBSERVED MONDAY AND IF THE CLOUDS CAN DEPART...TEMPS IN THE MID TO UPPER 80S WILL BE LIKELY. ANOTHER DECENT CHANCE FOR THUNDERSTORM ARRIVING MONDAY NIGHT WITH THE POTENTIAL FOR SOME OF THEM TO BE STRONG TO SEVERE. HAVE NOT INCREASE POPS DURING THIS TIME TOO MUCH OWING TO SOME UNCERTAINTY WITH COVERAGE AND EXACT TIMING. HOWEVER...WITH A SURFACE TROUGH AND FRONT PUSHING THROUGH THE AREA...DEVELOPMENT DEFINITELY APPEARS POSSIBLE. THIS FRONT SHOULD PUSH THROUGH THE CWA BY TUESDAY BUT THERE IS A POSSIBILITY THAT IT COULD LINGER ACROSS THE SOUTHERN CWA DURING THIS TIME. IF IT DOES...THERE WILL BE ADDITIONAL CHANCES OVER THE SOUTHERN CWA. RODRIGUEZ && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 00Z... * SCATTERED SHRA/TSRA THIS EVENING. * WIND DIRECTIONS...POSSIBLY EASTERLY...THIS EVENING. * MVFR VIS/CIGS OVERNIGHT/SUNDAY MORNING. * GUSTY NORTHWEST/WEST WINDS SUNDAY. * POSSIBLE LAKE BREEZE/NORTHEAST WIND SHIFT LATE SUNDAY AFTERNOON/ EARLY EVENING. CMS //DISCUSSION...UPDATED 00Z... THUNDERSTORMS CONTINUE TO DEVELOP ACROSS NORTHWEST AND NORTH CENTRAL IL EARLY THIS EVENING. WHILE THESE STORMS WEAKEN AS THEY MOVE EAST...THEY ARE SLOWLY MOVING FURTHER EAST AND EVENTUALLY... EXPECT THUNDER TO REACH THE CHICAGO AREA TERMINALS BUT CONFIDENCE REGARDING TIMING AND COVERAGE IS STILL SOMEWHAT UNCERTAIN. TWEAKED TIMING WITH THE 00Z TAFS BUT EXPECT ADDITIONAL REFINEMENTS WILL BE NEEDED IN THE NEXT FEW HOURS. AHEAD OF THE STORMS...LIGHT RAIN OR SHOWERS WILL ALSO BE POSSIBLE. HOW LONG THIS ACTIVITY PERSISTS INTO THE LATE EVENING IS ALSO UNCERTAIN AS SHORT TERM GUIDANCE SUGGESTS ACTIVITY COULD CONTINUE THRU 05Z-06Z. OUTFLOW FROM THESE SHOWERS/STORMS HAS CAUSED THE WIND FIELD TO BECOME QUITE DISTURBED. GENERALLY WESTERLY WINDS WILL LIKELY BECOME VARIABLE OVER THE NEXT FEW HOURS...POSSIBLY SHIFTING LIGHT EASTERLY THIS EVENING. WINDS SHOULD TURN BACK NORTHWEST OVERNIGHT AND THEN BEGIN TO INCREASE SUNDAY MORNING...TURNING MORE WESTERLY BY THE AFTERNOON. THERE IS SOME POTENTIAL THAT AS THESE WINDS BEGIN TO DIMINISH LATER SUNDAY AFTERNOON...THAT A LAKE BREEZE MAY FORM AND INCLUDED A POSSIBLE LAKE BREEZE EARLY SUNDAY EVENING WITH THE 30 HOUR ORD TAF. WITH THE LIGHT WINDS AND MOIST LOW LEVELS...APPEARS MVFR CIGS AND VIS WILL BE POSSIBLE OVERNIGHT...POSSIBLY DIPPING TO IFR IN SOME LOCATIONS. ANY LOWER CIGS OR FOG THAT DEVELOP SHOULD QUICKLY LIFT AND IMPROVE AFTER SUNRISE. CMS //ORD AND MDW CONFIDENCE...UPDATED 00Z... * HIGH FOR SHRA/TSRA THIS EVENING...MEDIUM FOR TIMING/COVERAGE. * LOW FOR WIND DIRECTIONS THIS EVENING...MEDIUM FOR WINDS OVERNIGHT/SUNDAY. * HIGH FOR MVFR VIS/CIGS OVERNIGHT/SUNDAY MORNING...MEDIUM FOR TIMING. CMS //OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z... * MONDAY...CHANCE OF SHRA/TSRA. STRONG/GUSTY SOUTHWEST WINDS. * TUESDAY...DRY/VFR. NORTHEAST WINDS. * WEDNESDAY AND THURSDAY...CHANCE OF SHRA/TSRA. EASTERLY WINDS. * FRIDAY...SLIGHT CHANCE OF SHRA/TSRA. NORTHEAST WINDS. && .MARINE... 408 PM CDT THERE WAS A BRIEF PERIOD OF STRONGER WINDS EARLIER THIS AFTERNOON OVER THE SOUTHERN HALF OF THE LAKE...POSSIBLY UP TO 33 KT FOR A TIME. HOWEVER...WINDS HAVE SINCE DIMINISHED BACK TO THE 10 TO 15 KT RANGE IN THE NEAR TERM. THESE SPEEDS WITH GENERALLY SOUTHERLY FLOW WILL CONTINUE THIS EVENING AND INTO A PORTION OF THE OVERNIGHT...BEFORE A TROUGH AND FRONTAL BOUNDARY MOVE ACROSS THE REGION. THIS WILL ALLOW FOR A WIND SHIFT TO THE NORTHWEST AND ALTHOUGH THERE COULD BE A SMALL WINDOW OF 10 TO 20 KT WINDS WITH THIS WIND SHIFT...THE MORE PREVAILING SPEEDS WILL BE IN THE 10 TO 15 KT RANGE. NORTHERLY FLOW WILL REMAIN SUNDAY MORNING BUT DIMINISH AND THEN LIKELY BECOME MORE LIGHT AND VARIABLE THROUGH THE REMAINDER OF THE DAY. EXPECT WINDS TO SHIFT BACK MORE SOUTHERLY SUNDAY NIGHT INTO MONDAY...AND THEN INCREASE DURING THIS TIME. THIS INCREASE WILL ESPECIALLY OCCUR MONDAY AFTERNOON INTO THE EVENING...WHEN SOUTHERLY WINDS UP TO 30 KT ARE APPEARING LIKELY. THIS WILL PERSIST UNTIL ANOTHER SYSTEM MOVES THROUGH MONDAY NIGHT...WITH WINDS THEN EXPECTED TO TURN TO THE NORTHWEST WHILE DIMINISHING. 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/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
547 PM CDT SAT JUN 20 2015 .MESOSCALE DISCUSSION... 547 PM CDT SHORTWAVE/SPEED MAX NOTED ON W/V MOVING FROM EASTERN IA INTO NORTHWEST IL WEAKENED CAPPING ENOUGH OVER OUR AREA FOR THUNDERSTORMS TO SPREAD EASTWARD. EARLIER SEVERE WARNED STORM INITIALLY SHOWED A GOOD WIND SIGNATURE BUT QUICKLY WEAKENED AND IT APPEARS SEVERE THREAT FOR NEXT FEW HOURS WILL BE FAIRLY MINIMAL WITH THUNDERSTORMS OVER NORTHWEST CWA AND MORE OF A HEAVY RAIN THREAT. THIS IS DUE TO STRONG MOISTURE TRANSPORT INTO THIS AREA AND PWAT VALUES INCREASING TO UPWARDS OF 1.5 INCHES ACCORDING TO LATEST SPC MESOANALYSIS. MAIN SEVERE THREAT THIS EVENING WILL BE TIED TO EVOLUTION OF BROKEN LINE OF CONVECTION ACROSS EASTERN IOWA THAT MAY PASS NEAR OR JUST SOUTHWEST OF FAR WEST AND SOUTHWEST CWA. MAIN THREAT BY THIS TIME/8-10 PM CDT/WOULD BE DAMAGING WINDS AND ALSO SEVERE HAIL. RC && .SHORT TERM... 329 PM CDT THROUGH TONIGHT... STILL LINGERING UNCERTAINTY REGARDING THE POTENTIAL FOR STRONG TO SEVERE STORMS THIS EVENING...WITH AN OVERALL TREND TOWARD A LOWER THREAT FOR THE THE NORTHEAST 1/2 TO 2/3 OF THE CWA. AS NOTED EARLIER...CLOUD COVER HAS OVERALL LIMITED DESTABILIZATION PROCESS EVEN IN PRESENCE OF GRADUALLY MOISTENING DEWPOINTS. ALSO A VERY STOUT WARM NOSE AT BASE OF EML ADVECTING WESTWARD CENTERED FROM 750-850 MB NOTED ON 18Z DVN SOUNDING WILL RESULT IN CAPPING/CINH AS DESTABILIZATION OCCURS LATE THIS AFTERNOON. ITS APPEARS THAT LINGERING CLUSTER OF THUNDERSTORMS OVER NORTHEAST IA AND NORTHWEST IL ON NOSE OF SPEED MAX SEEN ON W/V IMAGERY COULD BE MAIN FOCUS FOR WHAT OCCURS THIS EVENING...ONCE STRONGER FORCING ARRIVES AND WEAKENS THE CAP. IT STILL LOOKS THAT STRONGEST INSTABILITY AXIS WITH MLCAPE UP TO 1K TO 2K J/KG WILL RESIDE NEAR OR JUST WEST OF THE FAR WEST AND SOUTHWEST CWA. MORE ROBUST CONVECTION LIKELY WILL RIDE THIS NORTH- NORTHWEST TO SOUTH- SOUTHEAST AXIS THIS EVENING. THEREFORE...IN PRESENCE OF DEEP LAYER SHEAR OF 40-50 KT...HIGHEST POTENTIAL FOR SEVERE WEATHER IS FAVORED TO BE WEST OF DIXON TO OTTAWA TO PAXTON LINE...FAIRLY SIMILAR TO RECENT RUNS OF HRRR. UPSCALE GROWTH INTO MCS MAY BE OCCURRING BY TIME STORMS ARRIVE...SO PRIMARY THREATS FROM ANY SEVERE STORMS LOOK TO BE DAMAGING WIND GUSTS AND LARGE HAIL. FOR REST OF AREA...IT APPEARS BAND OF SHOWERS AND EMBEDDED STORMS WILL STILL PRESS SOUTHEAST AHEAD OF COLD FRONT AS DEPICTED ON RECENT HRRR RUNS...BUT WITH MUCH LOWER CHANCE FOR STRONG TO SEVERE THUNDERSTORMS. CLOUD TO GROUND LIGHTNING POTENTIAL MAY BE LIMITED BUT ALSO NON-ZERO FOR NORTHEAST ILLINOIS AND NORTHWEST INDIANA...SOMETHING TO KEEP IN MIND FOR OUTDOOR ACTIVITIES THIS EVENING. COULD END UP BEING MORE OF A SHOWER/EMBEDDED THUNDER SCENARIO. FINALLY...ANY ORGANIZED THUNDERSTORMS COULD PRODUCE HEAVY DOWNPOURS WITH HIGH PWAT IN 1.7 TO 1.8 INCH RANGE SAGGING SOUTHWARD AHEAD OF THE FRONT. THUS GIVEN RECENT HEAVY RAINS...WILL ALSO NEED TO MONITOR FOR FLOOD POTENTIAL THIS EVENING EVEN IN FASTER STORM MOTIONS. OVERNIGHT LOWS WILL BE IN THE UPPER 60S TO LOWER 70S...WITH 60S DEWPOINTS YIELDING MUGGY CONDITIONS. RC && .LONG TERM... 329 PM CDT SUNDAY THROUGH SATURDAY... MAIN FORECAST CONCERNS/CHALLENGES FOR THE PERIOD REMAIN WITH AN ACTIVE WEATHER PATTERN WITH PERIODIC CHANCES FOR SHOWERS/THUNDERSTORMS CONTINUING NEXT WEEK. THE PERIOD WILL BEGIN WITH FRONTAL BOUNDARY STILL LIKELY LINGERING ACROSS THE SOUTHERN THIRD OF THE CWA...WHERE UPPER 60S DEWPOINTS WILL STILL LIKELY RESIDE. WHILE CONVECTION FROM THE OVERNIGHT WILL HAVE LIKELY EXITED THE AREA BY THE MORNING...THERE APPEARS TO BE A CHANCE FOR FURTHER DEVELOPMENT ACROSS EAST CENTRAL ILLINOIS AND PORTIONS OF NORTHWEST INDIANA MAINLY SOUTH OF PONTIAC ILLINOIS TO MOROCCO INDIANA LINE. FORECAST SOUNDINGS IN THESE LOCATIONS ARE INDICATING INCREASING INSTABILITY WITH LITTLE TO NO CIN DURING THE MORNING AND ALTHOUGH THE CHANCE FOR ADDITIONAL DEVELOPMENT IS LOW...THERE DOES APPEAR TO BE A SMALL WINDOW BEFORE THE AXIS OF BEST DEVELOPMENT ALONG THIS BOUNDARY PUSHES SOUTH OF THE CWA BY MIDDAY. THE AFTERNOON WILL LIKELY BE DRY WITH CLEARING SKIES...AND WITH TEMPERATURES INCREASING INTO THE 80S. WINDS NEAR THE LAKE WILL BEGIN OUT OF THE NORTHWEST TO NORTH AND WITH A SHIFT TO THE NORTHEAST/EAST LIKELY BY MIDDAY...LIMITING TEMPS TO THE 70S. CONDITIONS APPEAR TO BE QUIET SUNDAY EVENING AND THROUGH MUCH OF SUNDAY NIGHT. HOWEVER...ATTENTION TURNS BACK WEST TOWARDS INCREASING MID LEVEL ENERGY AND A STRENGTHENING LLJ. THESE FEATURES WILL ALLOW FOR SHOWER/THUNDERSTORM DEVELOPMENT WELL WEST OF THE CWA ACROSS IOWA FOR MOST OF THE NIGHT. SOME OF THIS DEVELOPMENT COULD POSSIBLY REACH THE FAR WESTERN CWA LATE SUNDAY NIGHT INTO MONDAY MORNING AND HAVE MAINTAINED SLIGHT CHANCE WORDING DURING THIS TIME. THE BETTER CHANCES WILL COME MONDAY MORNING WHEN SCATTERED THUNDERSTORM DEVELOPMENT APPEARS POSSIBLE. VEERING LLJ...APPROACHING MID LEVEL SUPPORT...AND GOOD MOIST/TEMP ADVECTION SHOULD PROVIDE AMPLE SUPPORT FOR AT LEAST SCATTERED THUNDERSTORM DEVELOPMENT. WITH THIS DECENT FORCING IN PLACE AND WHILE MODERATE/STRONG INSTABILITY ALOFT QUICKLY LIFTS NORTH ACROSS THE CWA...COULD ALLOW FOR SOME OF THESE STORMS TO BE STRONG TO SEVERE. THE LIKELY HAZARD WOULD BE FOR LARGE HAIL...BEFORE THIS DEVELOPMENT LIFTS NORTH OF THE CWA BY MIDDAY. GUIDANCE DOES VARY TO HOW MONDAY AFTERNOON WILL EVOLVE WITH REGARD TO ADDITIONAL THUNDERSTORM DEVELOPMENT...BUT IT WOULD APPEAR THAT THERE WILL BE A DRY WINDOW DURING THIS TIME. PERSISTING WARM/MOIST PUSH RIDING ALONG STRONG SOUTH TO SOUTHWEST WINDS WILL BE OBSERVED MONDAY AND IF THE CLOUDS CAN DEPART...TEMPS IN THE MID TO UPPER 80S WILL BE LIKELY. ANOTHER DECENT CHANCE FOR THUNDERSTORM ARRIVING MONDAY NIGHT WITH THE POTENTIAL FOR SOME OF THEM TO BE STRONG TO SEVERE. HAVE NOT INCREASE POPS DURING THIS TIME TOO MUCH OWING TO SOME UNCERTAINTY WITH COVERAGE AND EXACT TIMING. HOWEVER...WITH A SURFACE TROUGH AND FRONT PUSHING THROUGH THE AREA...DEVELOPMENT DEFINITELY APPEARS POSSIBLE. THIS FRONT SHOULD PUSH THROUGH THE CWA BY TUESDAY BUT THERE IS A POSSIBILITY THAT IT COULD LINGER ACROSS THE SOUTHERN CWA DURING THIS TIME. IF IT DOES...THERE WILL BE ADDITIONAL CHANCES OVER THE SOUTHERN CWA. RODRIGUEZ && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 22Z... * SCATTERED SHRA/TSRA THIS EVENING. * POSSIBLE WIND SHIFT TO NORTHEAST THIS EVENING. * MVFR VIS/CIGS OVERNIGHT/SUNDAY MORNING. * POSSIBLE NORTHEAST WINDS SUNDAY. CMS //DISCUSSION...UPDATED 22Z... THUNDERSTORMS THAT CONTINUE TO DEVELOP OVER FAR NORTHWEST IL WEAKEN AS THEY MOVE EAST/SOUTHEAST INTO A LESS FAVORABLE ENVIRONMENT. HOWEVER...SHOWERS AND ISOLATED THUNDER WILL STILL BE POSSIBLE LATE THIS AFTERNOON. WINDS HAVE SHIFTED MORE WESTERLY WITH OUTFLOW FROM THIS ACTIVITY AND SHOULD REMAIN WESTERLY INTO EARLY THIS EVENING. MORE SIGNIFICANT AND WIDESPREAD THUNDERSTORMS HAVE DEVELOPED ACROSS EASTERN AND SOUTHERN IOWA AND THIS ACTIVITY IS EXPECTED TO MOVE SOUTHEAST THIS EVENING. HOW MUCH ADDITIONAL CONVECTION DEVELOPS ACROSS NORTHEAST IOWA...AND THEN MOVES ACROSS NORTHERN IL AND THE TERMINALS THIS EVENING...REMAINS UNCERTAIN AND HAVE MADE NO CHANGES TO CURRENT THUNDER TIMING AS THIS TIMING STILL LOOKS ON TRACK IF THUNDERSTORMS DO INDEED MOVE ACROSS THE TERMINALS. SHORT TERM GUIDANCE ALSO SUGGESTS WINDS MAY TURN NORTHEAST OFF THE LAKE LATER THIS EVENING. CONFIDENCE OF A WIND SHIFT IS LOW AS IS SPEEDS SHOULD WINDS SHIFT TO THE NORTHEAST. CMS PREVIOUS 18Z DISCUSSION... DECAYING AREA OF SHRA OVER NORTHERN IL WILL CONTINUE TO FALL APART AS IT MOVES EAST THROUGH THE RFD-ROCHELLE AREA. SOME OF WHAT IS APPEARING ON RADAR IS NOT REACHING THE GROUND AS RAIN. STRONG PRESSURE FALLS ASSOCIATED WITH DECAYING AREA OF CONVECTION OVER WI HELPING TO CAUSE SOUTH WINDS TO ACCELERATE INTO MESO LOW PRESSURE AREA CAUSING WINDS TO GUST 30-40 KT OVER NORTHWEST IL. EXPECT AREA OF HIGHER WIND SPEEDS AND GUSTS TO PROPAGATE EAST ACROSS NORTH CENTRAL IL EARLY THIS AFTERNOON. EXPECT ONGOING THUNDERSTORMS OVER IA TO EXPAND LATER THIS AFTERNOON AHEAD OF A COLD FRONT AND MOVE EAST AND THEN SOUTHEAST INTO IL THIS EVENING. EXPECT GREATEST COVERAGE AND INTENSITY OF TSTMS TO PASS WEST AND SOUTH OF THE TERMINALS THIS EVENING. WILL STILL SEE A PERIOD OF SHOWERS AND EMBEDDED THUNDERSTORMS AT ORD AND MDW PER TIMING IN TAFS. WITH LOW LEVEL MOISTURE LINGERING INTO THE MORNING HOURS BEHIND THE COLD FRONT... EXPECT MVFR VSBYS FOR A FEW HOURS AROUND SUNRISE. NORTHERLY WINDS BEHIND THE FRONT WILL INCREASE BY MID MORNING HELPING TO MIX OUT LIGHT FOG AND LOW CLOUDS. ED F //ORD AND MDW CONFIDENCE...UPDATED 22Z... * MEDIUM FOR SHRA/TSRA THIS EVENING. * LOW FOR WIND SHIFT TO NORTHEAST THIS EVENING. * HIGH FOR MVFR VIS/CIGS OVERNIGHT...MEDIUM FOR TIMING. * MEDIUM FOR WINDS SUNDAY. CMS //OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z... * SUNDAY NIGHT...VFR. WEST WINDS. * MONDAY...CHANCE OF SHRA/TSRA. SOUTHWEST WINDS. * TUESDAY AND WEDNESDAY...CHANCE OF SHRA/TSRA. EASTERLY WINDS. * THURSDAY...CHANCE OF SHRA/TSRA. SOUTHEAST WINDS TURNING SOUTHWEST. * FRIDAY...CHANCE OF SHRA/TSRA. NORTH TO NORTHEAST WINDS. LENNING && .MARINE... 408 PM CDT THERE WAS A BRIEF PERIOD OF STRONGER WINDS EARLIER THIS AFTERNOON OVER THE SOUTHERN HALF OF THE LAKE...POSSIBLY UP TO 33 KT FOR A TIME. HOWEVER...WINDS HAVE SINCE DIMINISHED BACK TO THE 10 TO 15 KT RANGE IN THE NEAR TERM. THESE SPEEDS WITH GENERALLY SOUTHERLY FLOW WILL CONTINUE THIS EVENING AND INTO A PORTION OF THE OVERNIGHT...BEFORE A TROUGH AND FRONTAL BOUNDARY MOVE ACROSS THE REGION. THIS WILL ALLOW FOR A WIND SHIFT TO THE NORTHWEST AND ALTHOUGH THERE COULD BE A SMALL WINDOW OF 10 TO 20 KT WINDS WITH THIS WIND SHIFT...THE MORE PREVAILING SPEEDS WILL BE IN THE 10 TO 15 KT RANGE. NORTHERLY FLOW WILL REMAIN SUNDAY MORNING BUT DIMINISH AND THEN LIKELY BECOME MORE LIGHT AND VARIABLE THROUGH THE REMAINDER OF THE DAY. EXPECT WINDS TO SHIFT BACK MORE SOUTHERLY SUNDAY NIGHT INTO MONDAY...AND THEN INCREASE DURING THIS TIME. THIS INCREASE WILL ESPECIALLY OCCUR MONDAY AFTERNOON INTO THE EVENING...WHEN SOUTHERLY WINDS UP TO 30 KT ARE APPEARING LIKELY. THIS WILL PERSIST UNTIL ANOTHER SYSTEM MOVES THROUGH MONDAY NIGHT...WITH WINDS THEN EXPECTED TO TURN TO THE NORTHWEST WHILE DIMINISHING. 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/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
517 PM CDT SAT JUN 20 2015 .SHORT TERM... 329 PM CDT THROUGH TONIGHT... STILL LINGERING UNCERTAINTY REGARDING THE POTENTIAL FOR STRONG TO SEVERE STORMS THIS EVENING...WITH AN OVERALL TREND TOWARD A LOWER THREAT FOR THE THE NORTHEAST 1/2 TO 2/3 OF THE CWA. AS NOTED EARLIER...CLOUD COVER HAS OVERALL LIMITED DESTABILIZATION PROCESS EVEN IN PRESENCE OF GRADUALLY MOISTENING DEWPOINTS. ALSO A VERY STOUT WARM NOSE AT BASE OF EML ADVECTING WESTWARD CENTERED FROM 750-850 MB NOTED ON 18Z DVN SOUNDING WILL RESULT IN CAPPING/CINH AS DESTABILIZATION OCCURS LATE THIS AFTERNOON. ITS APPEARS THAT LINGERING CLUSTER OF THUNDERSTORMS OVER NORTHEAST IA AND NORTHWEST IL ON NOSE OF SPEED MAX SEEN ON W/V IMAGERY COULD BE MAIN FOCUS FOR WHAT OCCURS THIS EVENING...ONCE STRONGER FORCING ARRIVES AND WEAKENS THE CAP. IT STILL LOOKS THAT STRONGEST INSTABILITY AXIS WITH MLCAPE UP TO 1K TO 2K J/KG WILL RESIDE NEAR OR JUST WEST OF THE FAR WEST AND SOUTHWEST CWA. MORE ROBUST CONVECTION LIKELY WILL RIDE THIS NORTH- NORTHWEST TO SOUTH- SOUTHEAST AXIS THIS EVENING. THEREFORE...IN PRESENCE OF DEEP LAYER SHEAR OF 40-50 KT...HIGHEST POTENTIAL FOR SEVERE WEATHER IS FAVORED TO BE WEST OF DIXON TO OTTAWA TO PAXTON LINE...FAIRLY SIMILAR TO RECENT RUNS OF HRRR. UPSCALE GROWTH INTO MCS MAY BE OCCURRING BY TIME STORMS ARRIVE...SO PRIMARY THREATS FROM ANY SEVERE STORMS LOOK TO BE DAMAGING WIND GUSTS AND LARGE HAIL. FOR REST OF AREA...IT APPEARS BAND OF SHOWERS AND EMBEDDED STORMS WILL STILL PRESS SOUTHEAST AHEAD OF COLD FRONT AS DEPICTED ON RECENT HRRR RUNS...BUT WITH MUCH LOWER CHANCE FOR STRONG TO SEVERE THUNDERSTORMS. CLOUD TO GROUND LIGHTNING POTENTIAL MAY BE LIMITED BUT ALSO NON-ZERO FOR NORTHEAST ILLINOIS AND NORTHWEST INDIANA...SOMETHING TO KEEP IN MIND FOR OUTDOOR ACTIVITIES THIS EVENING. COULD END UP BEING MORE OF A SHOWER/EMBEDDED THUNDER SCENARIO. FINALLY...ANY ORGANIZED THUNDERSTORMS COULD PRODUCE HEAVY DOWNPOURS WITH HIGH PWAT IN 1.7 TO 1.8 INCH RANGE SAGGING SOUTHWARD AHEAD OF THE FRONT. THUS GIVEN RECENT HEAVY RAINS...WILL ALSO NEED TO MONITOR FOR FLOOD POTENTIAL THIS EVENING EVEN IN FASTER STORM MOTIONS. OVERNIGHT LOWS WILL BE IN THE UPPER 60S TO LOWER 70S...WITH 60S DEWPOINTS YIELDING MUGGY CONDITIONS. RC && .LONG TERM... 329 PM CDT SUNDAY THROUGH SATURDAY... MAIN FORECAST CONCERNS/CHALLENGES FOR THE PERIOD REMAIN WITH AN ACTIVE WEATHER PATTERN WITH PERIODIC CHANCES FOR SHOWERS/THUNDERSTORMS CONTINUING NEXT WEEK. THE PERIOD WILL BEGIN WITH FRONTAL BOUNDARY STILL LIKELY LINGERING ACROSS THE SOUTHERN THIRD OF THE CWA...WHERE UPPER 60S DEWPOINTS WILL STILL LIKELY RESIDE. WHILE CONVECTION FROM THE OVERNIGHT WILL HAVE LIKELY EXITED THE AREA BY THE MORNING...THERE APPEARS TO BE A CHANCE FOR FURTHER DEVELOPMENT ACROSS EAST CENTRAL ILLINOIS AND PORTIONS OF NORTHWEST INDIANA MAINLY SOUTH OF PONTIAC ILLINOIS TO MOROCCO INDIANA LINE. FORECAST SOUNDINGS IN THESE LOCATIONS ARE INDICATING INCREASING INSTABILITY WITH LITTLE TO NO CIN DURING THE MORNING AND ALTHOUGH THE CHANCE FOR ADDITIONAL DEVELOPMENT IS LOW...THERE DOES APPEAR TO BE A SMALL WINDOW BEFORE THE AXIS OF BEST DEVELOPMENT ALONG THIS BOUNDARY PUSHES SOUTH OF THE CWA BY MIDDAY. THE AFTERNOON WILL LIKELY BE DRY WITH CLEARING SKIES...AND WITH TEMPERATURES INCREASING INTO THE 80S. WINDS NEAR THE LAKE WILL BEGIN OUT OF THE NORTHWEST TO NORTH AND WITH A SHIFT TO THE NORTHEAST/EAST LIKELY BY MIDDAY...LIMITING TEMPS TO THE 70S. CONDITIONS APPEAR TO BE QUIET SUNDAY EVENING AND THROUGH MUCH OF SUNDAY NIGHT. HOWEVER...ATTENTION TURNS BACK WEST TOWARDS INCREASING MID LEVEL ENERGY AND A STRENGTHENING LLJ. THESE FEATURES WILL ALLOW FOR SHOWER/THUNDERSTORM DEVELOPMENT WELL WEST OF THE CWA ACROSS IOWA FOR MOST OF THE NIGHT. SOME OF THIS DEVELOPMENT COULD POSSIBLY REACH THE FAR WESTERN CWA LATE SUNDAY NIGHT INTO MONDAY MORNING AND HAVE MAINTAINED SLIGHT CHANCE WORDING DURING THIS TIME. THE BETTER CHANCES WILL COME MONDAY MORNING WHEN SCATTERED THUNDERSTORM DEVELOPMENT APPEARS POSSIBLE. VEERING LLJ...APPROACHING MID LEVEL SUPPORT...AND GOOD MOIST/TEMP ADVECTION SHOULD PROVIDE AMPLE SUPPORT FOR AT LEAST SCATTERED THUNDERSTORM DEVELOPMENT. WITH THIS DECENT FORCING IN PLACE AND WHILE MODERATE/STRONG INSTABILITY ALOFT QUICKLY LIFTS NORTH ACROSS THE CWA...COULD ALLOW FOR SOME OF THESE STORMS TO BE STRONG TO SEVERE. THE LIKELY HAZARD WOULD BE FOR LARGE HAIL...BEFORE THIS DEVELOPMENT LIFTS NORTH OF THE CWA BY MIDDAY. GUIDANCE DOES VARY TO HOW MONDAY AFTERNOON WILL EVOLVE WITH REGARD TO ADDITIONAL THUNDERSTORM DEVELOPMENT...BUT IT WOULD APPEAR THAT THERE WILL BE A DRY WINDOW DURING THIS TIME. PERSISTING WARM/MOIST PUSH RIDING ALONG STRONG SOUTH TO SOUTHWEST WINDS WILL BE OBSERVED MONDAY AND IF THE CLOUDS CAN DEPART...TEMPS IN THE MID TO UPPER 80S WILL BE LIKELY. ANOTHER DECENT CHANCE FOR THUNDERSTORM ARRIVING MONDAY NIGHT WITH THE POTENTIAL FOR SOME OF THEM TO BE STRONG TO SEVERE. HAVE NOT INCREASE POPS DURING THIS TIME TOO MUCH OWING TO SOME UNCERTAINTY WITH COVERAGE AND EXACT TIMING. HOWEVER...WITH A SURFACE TROUGH AND FRONT PUSHING THROUGH THE AREA...DEVELOPMENT DEFINITELY APPEARS POSSIBLE. THIS FRONT SHOULD PUSH THROUGH THE CWA BY TUESDAY BUT THERE IS A POSSIBILITY THAT IT COULD LINGER ACROSS THE SOUTHERN CWA DURING THIS TIME. IF IT DOES...THERE WILL BE ADDITIONAL CHANCES OVER THE SOUTHERN CWA. RODRIGUEZ && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 22Z... * SCATTERED SHRA/TSRA THIS EVENING. * POSSIBLE WIND SHIFT TO NORTHEAST THIS EVENING. * MVFR VIS/CIGS OVERNIGHT/SUNDAY MORNING. * POSSIBLE NORTHEAST WINDS SUNDAY. CMS //DISCUSSION...UPDATED 22Z... THUNDERSTORMS THAT CONTINUE TO DEVELOP OVER FAR NORTHWEST IL WEAKEN AS THEY MOVE EAST/SOUTHEAST INTO A LESS FAVORABLE ENVIRONMENT. HOWEVER...SHOWERS AND ISOLATED THUNDER WILL STILL BE POSSIBLE LATE THIS AFTERNOON. WINDS HAVE SHIFTED MORE WESTERLY WITH OUTFLOW FROM THIS ACTIVITY AND SHOULD REMAIN WESTERLY INTO EARLY THIS EVENING. MORE SIGNIFICANT AND WIDESPREAD THUNDERSTORMS HAVE DEVELOPED ACROSS EASTERN AND SOUTHERN IOWA AND THIS ACTIVITY IS EXPECTED TO MOVE SOUTHEAST THIS EVENING. HOW MUCH ADDITIONAL CONVECTION DEVELOPS ACROSS NORTHEAST IOWA...AND THEN MOVES ACROSS NORTHERN IL AND THE TERMINALS THIS EVENING...REMAINS UNCERTAIN AND HAVE MADE NO CHANGES TO CURRENT THUNDER TIMING AS THIS TIMING STILL LOOKS ON TRACK IF THUNDERSTORMS DO INDEED MOVE ACROSS THE TERMINALS. SHORT TERM GUIDANCE ALSO SUGGESTS WINDS MAY TURN NORTHEAST OFF THE LAKE LATER THIS EVENING. CONFIDENCE OF A WIND SHIFT IS LOW AS IS SPEEDS SHOULD WINDS SHIFT TO THE NORTHEAST. CMS PREVIOUS 18Z DISCUSSION... DECAYING AREA OF SHRA OVER NORTHERN IL WILL CONTINUE TO FALL APART AS IT MOVES EAST THROUGH THE RFD-ROCHELLE AREA. SOME OF WHAT IS APPEARING ON RADAR IS NOT REACHING THE GROUND AS RAIN. STRONG PRESSURE FALLS ASSOCIATED WITH DECAYING AREA OF CONVECTION OVER WI HELPING TO CAUSE SOUTH WINDS TO ACCELERATE INTO MESO LOW PRESSURE AREA CAUSING WINDS TO GUST 30-40 KT OVER NORTHWEST IL. EXPECT AREA OF HIGHER WIND SPEEDS AND GUSTS TO PROPAGATE EAST ACROSS NORTH CENTRAL IL EARLY THIS AFTERNOON. EXPECT ONGOING THUNDERSTORMS OVER IA TO EXPAND LATER THIS AFTERNOON AHEAD OF A COLD FRONT AND MOVE EAST AND THEN SOUTHEAST INTO IL THIS EVENING. EXPECT GREATEST COVERAGE AND INTENSITY OF TSTMS TO PASS WEST AND SOUTH OF THE TERMINALS THIS EVENING. WILL STILL SEE A PERIOD OF SHOWERS AND EMBEDDED THUNDERSTORMS AT ORD AND MDW PER TIMING IN TAFS. WITH LOW LEVEL MOISTURE LINGERING INTO THE MORNING HOURS BEHIND THE COLD FRONT... EXPECT MVFR VSBYS FOR A FEW HOURS AROUND SUNRISE. NORTHERLY WINDS BEHIND THE FRONT WILL INCREASE BY MID MORNING HELPING TO MIX OUT LIGHT FOG AND LOW CLOUDS. ED F //ORD AND MDW CONFIDENCE...UPDATED 22Z... * MEDIUM FOR SHRA/TSRA THIS EVENING. * LOW FOR WIND SHIFT TO NORTHEAST THIS EVENING. * HIGH FOR MVFR VIS/CIGS OVERNIGHT...MEDIUM FOR TIMING. * MEDIUM FOR WINDS SUNDAY. CMS //OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z... * SUNDAY NIGHT...VFR. WEST WINDS. * MONDAY...CHANCE OF SHRA/TSRA. SOUTHWEST WINDS. * TUESDAY AND WEDNESDAY...CHANCE OF SHRA/TSRA. EASTERLY WINDS. * THURSDAY...CHANCE OF SHRA/TSRA. SOUTHEAST WINDS TURNING SOUTHWEST. * FRIDAY...CHANCE OF SHRA/TSRA. NORTH TO NORTHEAST WINDS. LENNING && .MARINE... 408 PM CDT THERE WAS A BRIEF PERIOD OF STRONGER WINDS EARLIER THIS AFTERNOON OVER THE SOUTHERN HALF OF THE LAKE...POSSIBLY UP TO 33 KT FOR A TIME. HOWEVER...WINDS HAVE SINCE DIMINISHED BACK TO THE 10 TO 15 KT RANGE IN THE NEAR TERM. THESE SPEEDS WITH GENERALLY SOUTHERLY FLOW WILL CONTINUE THIS EVENING AND INTO A PORTION OF THE OVERNIGHT...BEFORE A TROUGH AND FRONTAL BOUNDARY MOVE ACROSS THE REGION. THIS WILL ALLOW FOR A WIND SHIFT TO THE NORTHWEST AND ALTHOUGH THERE COULD BE A SMALL WINDOW OF 10 TO 20 KT WINDS WITH THIS WIND SHIFT...THE MORE PREVAILING SPEEDS WILL BE IN THE 10 TO 15 KT RANGE. NORTHERLY FLOW WILL REMAIN SUNDAY MORNING BUT DIMINISH AND THEN LIKELY BECOME MORE LIGHT AND VARIABLE THROUGH THE REMAINDER OF THE DAY. EXPECT WINDS TO SHIFT BACK MORE SOUTHERLY SUNDAY NIGHT INTO MONDAY...AND THEN INCREASE DURING THIS TIME. THIS INCREASE WILL ESPECIALLY OCCUR MONDAY AFTERNOON INTO THE EVENING...WHEN SOUTHERLY WINDS UP TO 30 KT ARE APPEARING LIKELY. THIS WILL PERSIST UNTIL ANOTHER SYSTEM MOVES THROUGH MONDAY NIGHT...WITH WINDS THEN EXPECTED TO TURN TO THE NORTHWEST WHILE DIMINISHING. 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/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
408 PM CDT SAT JUN 20 2015 .SHORT TERM... 329 PM CDT THROUGH TONIGHT... STILL LINGERING UNCERTAINTY REGARDING THE POTENTIAL FOR STRONG TO SEVERE STORMS THIS EVENING...WITH AN OVERALL TREND TOWARD A LOWER THREAT FOR THE THE NORTHEAST 1/2 TO 2/3 OF THE CWA. AS NOTED EARLIER...CLOUD COVER HAS OVERALL LIMITED DESTABILIZATION PROCESS EVEN IN PRESENCE OF GRADUALLY MOISTENING DEWPOINTS. ALSO A VERY STOUT WARM NOSE AT BASE OF EML ADVECTING WESTWARD CENTERED FROM 750-850 MB NOTED ON 18Z DVN SOUNDING WILL RESULT IN CAPPING/CINH AS DESTABILIZATION OCCURS LATE THIS AFTERNOON. ITS APPEARS THAT LINGERING CLUSTER OF THUNDERSTORMS OVER NORTHEAST IA AND NORTHWEST IL ON NOSE OF SPEED MAX SEEN ON W/V IMAGERY COULD BE MAIN FOCUS FOR WHAT OCCURS THIS EVENING...ONCE STRONGER FORCING ARRIVES AND WEAKENS THE CAP. IT STILL LOOKS THAT STRONGEST INSTABILITY AXIS WITH MLCAPE UP TO 1K TO 2K J/KG WILL RESIDE NEAR OR JUST WEST OF THE FAR WEST AND SOUTHWEST CWA. MORE ROBUST CONVECTION LIKELY WILL RIDE THIS NORTH- NORTHWEST TO SOUTH- SOUTHEAST AXIS THIS EVENING. THEREFORE...IN PRESENCE OF DEEP LAYER SHEAR OF 40-50 KT...HIGHEST POTENTIAL FOR SEVERE WEATHER IS FAVORED TO BE WEST OF DIXON TO OTTAWA TO PAXTON LINE...FAIRLY SIMILAR TO RECENT RUNS OF HRRR. UPSCALE GROWTH INTO MCS MAY BE OCCURRING BY TIME STORMS ARRIVE...SO PRIMARY THREATS FROM ANY SEVERE STORMS LOOK TO BE DAMAGING WIND GUSTS AND LARGE HAIL. FOR REST OF AREA...IT APPEARS BAND OF SHOWERS AND EMBEDDED STORMS WILL STILL PRESS SOUTHEAST AHEAD OF COLD FRONT AS DEPICTED ON RECENT HRRR RUNS...BUT WITH MUCH LOWER CHANCE FOR STRONG TO SEVERE THUNDERSTORMS. CLOUD TO GROUND LIGHTNING POTENTIAL MAY BE LIMITED BUT ALSO NON-ZERO FOR NORTHEAST ILLINOIS AND NORTHWEST INDIANA...SOMETHING TO KEEP IN MIND FOR OUTDOOR ACTIVITIES THIS EVENING. COULD END UP BEING MORE OF A SHOWER/EMBEDDED THUNDER SCENARIO. FINALLY...ANY ORGANIZED THUNDERSTORMS COULD PRODUCE HEAVY DOWNPOURS WITH HIGH PWAT IN 1.7 TO 1.8 INCH RANGE SAGGING SOUTHWARD AHEAD OF THE FRONT. THUS GIVEN RECENT HEAVY RAINS...WILL ALSO NEED TO MONITOR FOR FLOOD POTENTIAL THIS EVENING EVEN IN FASTER STORM MOTIONS. OVERNIGHT LOWS WILL BE IN THE UPPER 60S TO LOWER 70S...WITH 60S DEWPOINTS YIELDING MUGGY CONDITIONS. RC && .LONG TERM... 329 PM CDT SUNDAY THROUGH SATURDAY... MAIN FORECAST CONCERNS/CHALLENGES FOR THE PERIOD REMAIN WITH AN ACTIVE WEATHER PATTERN WITH PERIODIC CHANCES FOR SHOWERS/THUNDERSTORMS CONTINUING NEXT WEEK. THE PERIOD WILL BEGIN WITH FRONTAL BOUNDARY STILL LIKELY LINGERING ACROSS THE SOUTHERN THIRD OF THE CWA...WHERE UPPER 60S DEWPOINTS WILL STILL LIKELY RESIDE. WHILE CONVECTION FROM THE OVERNIGHT WILL HAVE LIKELY EXITED THE AREA BY THE MORNING...THERE APPEARS TO BE A CHANCE FOR FURTHER DEVELOPMENT ACROSS EAST CENTRAL ILLINOIS AND PORTIONS OF NORTHWEST INDIANA MAINLY SOUTH OF PONTIAC ILLINOIS TO MOROCCO INDIANA LINE. FORECAST SOUNDINGS IN THESE LOCATIONS ARE INDICATING INCREASING INSTABILITY WITH LITTLE TO NO CIN DURING THE MORNING AND ALTHOUGH THE CHANCE FOR ADDITIONAL DEVELOPMENT IS LOW...THERE DOES APPEAR TO BE A SMALL WINDOW BEFORE THE AXIS OF BEST DEVELOPMENT ALONG THIS BOUNDARY PUSHES SOUTH OF THE CWA BY MIDDAY. THE AFTERNOON WILL LIKELY BE DRY WITH CLEARING SKIES...AND WITH TEMPERATURES INCREASING INTO THE 80S. WINDS NEAR THE LAKE WILL BEGIN OUT OF THE NORTHWEST TO NORTH AND WITH A SHIFT TO THE NORTHEAST/EAST LIKELY BY MIDDAY...LIMITING TEMPS TO THE 70S. CONDITIONS APPEAR TO BE QUIET SUNDAY EVENING AND THROUGH MUCH OF SUNDAY NIGHT. HOWEVER...ATTENTION TURNS BACK WEST TOWARDS INCREASING MID LEVEL ENERGY AND A STRENGTHENING LLJ. THESE FEATURES WILL ALLOW FOR SHOWER/THUNDERSTORM DEVELOPMENT WELL WEST OF THE CWA ACROSS IOWA FOR MOST OF THE NIGHT. SOME OF THIS DEVELOPMENT COULD POSSIBLY REACH THE FAR WESTERN CWA LATE SUNDAY NIGHT INTO MONDAY MORNING AND HAVE MAINTAINED SLIGHT CHANCE WORDING DURING THIS TIME. THE BETTER CHANCES WILL COME MONDAY MORNING WHEN SCATTERED THUNDERSTORM DEVELOPMENT APPEARS POSSIBLE. VEERING LLJ...APPROACHING MID LEVEL SUPPORT...AND GOOD MOIST/TEMP ADVECTION SHOULD PROVIDE AMPLE SUPPORT FOR AT LEAST SCATTERED THUNDERSTORM DEVELOPMENT. WITH THIS DECENT FORCING IN PLACE AND WHILE MODERATE/STRONG INSTABILITY ALOFT QUICKLY LIFTS NORTH ACROSS THE CWA...COULD ALLOW FOR SOME OF THESE STORMS TO BE STRONG TO SEVERE. THE LIKELY HAZARD WOULD BE FOR LARGE HAIL...BEFORE THIS DEVELOPMENT LIFTS NORTH OF THE CWA BY MIDDAY. GUIDANCE DOES VARY TO HOW MONDAY AFTERNOON WILL EVOLVE WITH REGARD TO ADDITIONAL THUNDERSTORM DEVELOPMENT...BUT IT WOULD APPEAR THAT THERE WILL BE A DRY WINDOW DURING THIS TIME. PERSISTING WARM/MOIST PUSH RIDING ALONG STRONG SOUTH TO SOUTHWEST WINDS WILL BE OBSERVED MONDAY AND IF THE CLOUDS CAN DEPART...TEMPS IN THE MID TO UPPER 80S WILL BE LIKELY. ANOTHER DECENT CHANCE FOR THUNDERSTORM ARRIVING MONDAY NIGHT WITH THE POTENTIAL FOR SOME OF THEM TO BE STRONG TO SEVERE. HAVE NOT INCREASE POPS DURING THIS TIME TOO MUCH OWING TO SOME UNCERTAINTY WITH COVERAGE AND EXACT TIMING. HOWEVER...WITH A SURFACE TROUGH AND FRONT PUSHING THROUGH THE AREA...DEVELOPMENT DEFINITELY APPEARS POSSIBLE. THIS FRONT SHOULD PUSH THROUGH THE CWA BY TUESDAY BUT THERE IS A POSSIBILITY THAT IT COULD LINGER ACROSS THE SOUTHERN CWA DURING THIS TIME. IF IT DOES...THERE WILL BE ADDITIONAL CHANCES OVER THE SOUTHERN CWA. RODRIGUEZ && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * THUNDERSTORMS REDEVELOPING WEST OF THE AREA THIS AFTERNOON. * SPECIFIC TIMING AND NATURE OF THUNDERSTORMS AS THEY REACH ORD AND MDW THIS EVENING. * SFC WINDS FROM THE SOUTH AND GUSTY AT TIMES. ED F //DISCUSSION...UPDATED 18Z... DECAYING AREA OF SHRA OVER NORTHERN IL WILL CONTINUE TO FALL APART AS IT MOVES EAST THROUGH THE RFD-ROCHELLE AREA. SOME OF WHAT IS APPEARING ON RADAR IS NOT REACHING THE GROUND AS RAIN. STRONG PRESSURE FALLS ASSOCIATED WITH DECAYING AREA OF CONVECTION OVER WI HELPING TO CAUSE SOUTH WINDS TO ACCELERATE INTO MESO LOW PRESSURE AREA CAUSING WINDS TO GUST 30-40 KT OVER NORTHWEST IL. EXPECT AREA OF HIGHER WIND SPEEDS AND GUSTS TO PROPAGATE EAST ACROSS NORTH CENTRAL IL EARLY THIS AFTERNOON. EXPECT ONGOING THUNDERSTORMS OVER IA TO EXPAND LATER THIS AFTERNOON AHEAD OF A COLD FRONT AND MOVE EAST AND THEN SOUTHEAST INTO IL THIS EVENING. EXPECT GREATEST COVERAGE AND INTENSITY OF TSTMS TO PASS WEST AND SOUTH OF THE TERMINALS THIS EVENING. WILL STILL SEE A PERIOD OF SHOWERS AND EMBEDDED THUNDERSTORMS AT ORD AND MDW PER TIMING IN TAFS. WITH LOW LEVEL MOISTURE LINGERING INTO THE MORNING HOURS BEHIND THE COLD FRONT... EXPECT MVFR VSBYS FOR A FEW HOURS AROUND SUNRISE. NORTHERLY WINDS BEHIND THE FRONT WILL INCREASE BY MID MORNING HELPING TO MIX OUT LIGHT FOG AND LOW CLOUDS. ED F //ORD AND MDW CONFIDENCE...UPDATED 20Z... * MEDIUM TO HIGH CONFIDENCE IN ARRIVAL TIME OF VCTS 8-9PM AT ORD AND MDW. PERIOD OF RAIN/TSRA EXPECTED TO FOLLOW PER TAFS. * LOW TO MEDIUM CONFIDENCE IN NATURE OF CONVECTION... INTENSITY AND DURATION AT ORD AND MDW. * MEDIUM TO HIGH CONFIDENCE IN WIND FCST. ED F //OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z... * SUNDAY NIGHT...VFR. WEST WINDS. * MONDAY...CHANCE OF SHRA/TSRA. SOUTHWEST WINDS. * TUESDAY AND WEDNESDAY...CHANCE OF SHRA/TSRA. EASTERLY WINDS. * THURSDAY...CHANCE OF SHRA/TSRA. SOUTHEAST WINDS TURNING SOUTHWEST. * FRIDAY...CHANCE OF SHRA/TSRA. NORTH TO NORTHEAST WINDS. LENNING && .MARINE... 408 PM CDT THERE WAS A BRIEF PERIOD OF STRONGER WINDS EARLIER THIS AFTERNOON OVER THE SOUTHERN HALF OF THE LAKE...POSSIBLY UP TO 33 KT FOR A TIME. HOWEVER...WINDS HAVE SINCE DIMINISHED BACK TO THE 10 TO 15 KT RANGE IN THE NEAR TERM. THESE SPEEDS WITH GENERALLY SOUTHERLY FLOW WILL CONTINUE THIS EVENING AND INTO A PORTION OF THE OVERNIGHT...BEFORE A TROUGH AND FRONTAL BOUNDARY MOVE ACROSS THE REGION. THIS WILL ALLOW FOR A WIND SHIFT TO THE NORTHWEST AND ALTHOUGH THERE COULD BE A SMALL WINDOW OF 10 TO 20 KT WINDS WITH THIS WIND SHIFT...THE MORE PREVAILING SPEEDS WILL BE IN THE 10 TO 15 KT RANGE. NORTHERLY FLOW WILL REMAIN SUNDAY MORNING BUT DIMINISH AND THEN LIKELY BECOME MORE LIGHT AND VARIABLE THROUGH THE REMAINDER OF THE DAY. EXPECT WINDS TO SHIFT BACK MORE SOUTHERLY SUNDAY NIGHT INTO MONDAY...AND THEN INCREASE DURING THIS TIME. THIS INCREASE WILL ESPECIALLY OCCUR MONDAY AFTERNOON INTO THE EVENING...WHEN SOUTHERLY WINDS UP TO 30 KT ARE APPEARING LIKELY. THIS WILL PERSIST UNTIL ANOTHER SYSTEM MOVES THROUGH MONDAY NIGHT...WITH WINDS THEN EXPECTED TO TURN TO THE NORTHWEST WHILE DIMINISHING. 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/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
329 PM CDT SAT JUN 20 2015 .SHORT TERM... 329 PM CDT THROUGH TONIGHT... STILL LINGERING UNCERTAINTY REGARDING THE POTENTIAL FOR STRONG TO SEVERE STORMS THIS EVENING...WITH AN OVERALL TREND TOWARD A LOWER THREAT FOR THE THE NORTHEAST 1/2 TO 2/3 OF THE CWA. AS NOTED EARLIER...CLOUD COVER HAS OVERALL LIMITED DESTABILIZATION PROCESS EVEN IN PRESENCE OF GRADUALLY MOISTENING DEWPOINTS. ALSO A VERY STOUT WARM NOSE AT BASE OF EML ADVECTING WESTWARD CENTERED FROM 750-850 MB NOTED ON 18Z DVN SOUNDING WILL RESULT IN CAPPING/CINH AS DESTABILIZATION OCCURS LATE THIS AFTERNOON. ITS APPEARS THAT LINGERING CLUSTER OF THUNDERSTORMS OVER NORTHEAST IA AND NORTHWEST IL ON NOSE OF SPEED MAX SEEN ON W/V IMAGERY COULD BE MAIN FOCUS FOR WHAT OCCURS THIS EVENING...ONCE STRONGER FORCING ARRIVES AND WEAKENS THE CAP. IT STILL LOOKS THAT STRONGEST INSTABILITY AXIS WITH MLCAPE UP TO 1K TO 2K J/KG WILL RESIDE NEAR OR JUST WEST OF THE FAR WEST AND SOUTHWEST CWA. MORE ROBUST CONVECTION LIKELY WILL RIDE THIS NORTH- NORTHWEST TO SOUTH- SOUTHEAST AXIS THIS EVENING. THEREFORE...IN PRESENCE OF DEEP LAYER SHEAR OF 40-50 KT...HIGHEST POTENTIAL FOR SEVERE WEATHER IS FAVORED TO BE WEST OF DIXON TO OTTAWA TO PAXTON LINE...FAIRLY SIMILAR TO RECENT RUNS OF HRRR. UPSCALE GROWTH INTO MCS MAY BE OCCURRING BY TIME STORMS ARRIVE...SO PRIMARY THREATS FROM ANY SEVERE STORMS LOOK TO BE DAMAGING WIND GUSTS AND LARGE HAIL. FOR REST OF AREA...IT APPEARS BAND OF SHOWERS AND EMBEDDED STORMS WILL STILL PRESS SOUTHEAST AHEAD OF COLD FRONT AS DEPICTED ON RECENT HRRR RUNS...BUT WITH MUCH LOWER CHANCE FOR STRONG TO SEVERE THUNDERSTORMS. CLOUD TO GROUND LIGHTNING POTENTIAL MAY BE LIMITED BUT ALSO NON-ZERO FOR NORTHEAST ILLINOIS AND NORTHWEST INDIANA...SOMETHING TO KEEP IN MIND FOR OUTDOOR ACTIVITIES THIS EVENING. COULD END UP BEING MORE OF A SHOWER/EMBEDDED THUNDER SCENARIO. FINALLY...ANY ORGANIZED THUNDERSTORMS COULD PRODUCE HEAVY DOWNPOURS WITH HIGH PWAT IN 1.7 TO 1.8 INCH RANGE SAGGING SOUTHWARD AHEAD OF THE FRONT. THUS GIVEN RECENT HEAVY RAINS...WILL ALSO NEED TO MONITOR FOR FLOOD POTENTIAL THIS EVENING EVEN IN FASTER STORM MOTIONS. OVERNIGHT LOWS WILL BE IN THE UPPER 60S TO LOWER 70S...WITH 60S DEWPOINTS YIELDING MUGGY CONDITIONS. RC && .LONG TERM... 329 PM CDT SUNDAY THROUGH SATURDAY... MAIN FORECAST CONCERNS/CHALLENGES FOR THE PERIOD REMAIN WITH AN ACTIVE WEATHER PATTERN WITH PERIODIC CHANCES FOR SHOWERS/THUNDERSTORMS CONTINUING NEXT WEEK. THE PERIOD WILL BEGIN WITH FRONTAL BOUNDARY STILL LIKELY LINGERING ACROSS THE SOUTHERN THIRD OF THE CWA...WHERE UPPER 60S DEWPOINTS WILL STILL LIKELY RESIDE. WHILE CONVECTION FROM THE OVERNIGHT WILL HAVE LIKELY EXITED THE AREA BY THE MORNING...THERE APPEARS TO BE A CHANCE FOR FURTHER DEVELOPMENT ACROSS EAST CENTRAL ILLINOIS AND PORTIONS OF NORTHWEST INDIANA MAINLY SOUTH OF PONTIAC ILLINOIS TO MOROCCO INDIANA LINE. FORECAST SOUNDINGS IN THESE LOCATIONS ARE INDICATING INCREASING INSTABILITY WITH LITTLE TO NO CIN DURING THE MORNING AND ALTHOUGH THE CHANCE FOR ADDITIONAL DEVELOPMENT IS LOW...THERE DOES APPEAR TO BE A SMALL WINDOW BEFORE THE AXIS OF BEST DEVELOPMENT ALONG THIS BOUNDARY PUSHES SOUTH OF THE CWA BY MIDDAY. THE AFTERNOON WILL LIKELY BE DRY WITH CLEARING SKIES...AND WITH TEMPERATURES INCREASING INTO THE 80S. WINDS NEAR THE LAKE WILL BEGIN OUT OF THE NORTHWEST TO NORTH AND WITH A SHIFT TO THE NORTHEAST/EAST LIKELY BY MIDDAY...LIMITING TEMPS TO THE 70S. CONDITIONS APPEAR TO BE QUIET SUNDAY EVENING AND THROUGH MUCH OF SUNDAY NIGHT. HOWEVER...ATTENTION TURNS BACK WEST TOWARDS INCREASING MID LEVEL ENERGY AND A STRENGTHENING LLJ. THESE FEATURES WILL ALLOW FOR SHOWER/THUNDERSTORM DEVELOPMENT WELL WEST OF THE CWA ACROSS IOWA FOR MOST OF THE NIGHT. SOME OF THIS DEVELOPMENT COULD POSSIBLY REACH THE FAR WESTERN CWA LATE SUNDAY NIGHT INTO MONDAY MORNING AND HAVE MAINTAINED SLIGHT CHANCE WORDING DURING THIS TIME. THE BETTER CHANCES WILL COME MONDAY MORNING WHEN SCATTERED THUNDERSTORM DEVELOPMENT APPEARS POSSIBLE. VEERING LLJ...APPROACHING MID LEVEL SUPPORT...AND GOOD MOIST/TEMP ADVECTION SHOULD PROVIDE AMPLE SUPPORT FOR AT LEAST SCATTERED THUNDERSTORM DEVELOPMENT. WITH THIS DECENT FORCING IN PLACE AND WHILE MODERATE/STRONG INSTABILITY ALOFT QUICKLY LIFTS NORTH ACROSS THE CWA...COULD ALLOW FOR SOME OF THESE STORMS TO BE STRONG TO SEVERE. THE LIKELY HAZARD WOULD BE FOR LARGE HAIL...BEFORE THIS DEVELOPMENT LIFTS NORTH OF THE CWA BY MIDDAY. GUIDANCE DOES VARY TO HOW MONDAY AFTERNOON WILL EVOLVE WITH REGARD TO ADDITIONAL THUNDERSTORM DEVELOPMENT...BUT IT WOULD APPEAR THAT THERE WILL BE A DRY WINDOW DURING THIS TIME. PERSISTING WARM/MOIST PUSH RIDING ALONG STRONG SOUTH TO SOUTHWEST WINDS WILL BE OBSERVED MONDAY AND IF THE CLOUDS CAN DEPART...TEMPS IN THE MID TO UPPER 80S WILL BE LIKELY. ANOTHER DECENT CHANCE FOR THUNDERSTORM ARRIVING MONDAY NIGHT WITH THE POTENTIAL FOR SOME OF THEM TO BE STRONG TO SEVERE. HAVE NOT INCREASE POPS DURING THIS TIME TOO MUCH OWING TO SOME UNCERTAINTY WITH COVERAGE AND EXACT TIMING. HOWEVER...WITH A SURFACE TROUGH AND FRONT PUSHING THROUGH THE AREA...DEVELOPMENT DEFINITELY APPEARS POSSIBLE. THIS FRONT SHOULD PUSH THROUGH THE CWA BY TUESDAY BUT THERE IS A POSSIBILITY THAT IT COULD LINGER ACROSS THE SOUTHERN CWA DURING THIS TIME. IF IT DOES...THERE WILL BE ADDITIONAL CHANCES OVER THE SOUTHERN CWA. RODRIGUEZ && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * THUNDERSTORMS REDEVELOPING WEST OF THE AREA THIS AFTERNOON. * SPECIFIC TIMING AND NATURE OF THUNDERSTORMS AS THEY REACH ORD AND MDW THIS EVENING. * SFC WINDS FROM THE SOUTH AND GUSTY AT TIMES. ED F //DISCUSSION...UPDATED 18Z... DECAYING AREA OF SHRA OVER NORTHERN IL WILL CONTINUE TO FALL APART AS IT MOVES EAST THROUGH THE RFD-ROCHELLE AREA. SOME OF WHAT IS APPEARING ON RADAR IS NOT REACHING THE GROUND AS RAIN. STRONG PRESSURE FALLS ASSOCIATED WITH DECAYING AREA OF CONVECTION OVER WI HELPING TO CAUSE SOUTH WINDS TO ACCELERATE INTO MESO LOW PRESSURE AREA CAUSING WINDS TO GUST 30-40 KT OVER NORTHWEST IL. EXPECT AREA OF HIGHER WIND SPEEDS AND GUSTS TO PROPAGATE EAST ACROSS NORTH CENTRAL IL EARLY THIS AFTERNOON. EXPECT ONGOING THUNDERSTORMS OVER IA TO EXPAND LATER THIS AFTERNOON AHEAD OF A COLD FRONT AND MOVE EAST AND THEN SOUTHEAST INTO IL THIS EVENING. EXPECT GREATEST COVERAGE AND INTENSITY OF TSTMS TO PASS WEST AND SOUTH OF THE TERMINALS THIS EVENING. WILL STILL SEE A PERIOD OF SHOWERS AND EMBEDDED THUNDERSTORMS AT ORD AND MDW PER TIMING IN TAFS. WITH LOW LEVEL MOISTURE LINGERING INTO THE MORNING HOURS BEHIND THE COLD FRONT... EXPECT MVFR VSBYS FOR A FEW HOURS AROUND SUNRISE. NORTHERLY WINDS BEHIND THE FRONT WILL INCREASE BY MID MORNING HELPING TO MIX OUT LIGHT FOG AND LOW CLOUDS. ED F //ORD AND MDW CONFIDENCE...UPDATED 20Z... * MEDIUM TO HIGH CONFIDENCE IN ARRIVAL TIME OF VCTS 8-9PM AT ORD AND MDW. PERIOD OF RAIN/TSRA EXPECTED TO FOLLOW PER TAFS. * LOW TO MEDIUM CONFIDENCE IN NATURE OF CONVECTION... INTENSITY AND DURATION AT ORD AND MDW. * MEDIUM TO HIGH CONFIDENCE IN WIND FCST. ED F //OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z... * SUNDAY NIGHT...VFR. WEST WINDS. * MONDAY...CHANCE OF SHRA/TSRA. SOUTHWEST WINDS. * TUESDAY AND WEDNESDAY...CHANCE OF SHRA/TSRA. EASTERLY WINDS. * THURSDAY...CHANCE OF SHRA/TSRA. SOUTHEAST WINDS TURNING SOUTHWEST. * FRIDAY...CHANCE OF SHRA/TSRA. NORTH TO NORTHEAST WINDS. LENNING && .MARINE... 256 AM CDT EASTERLY FLOW EARLY TODAY WILL TURN SOUTH AS LOW PRESSURE MOVES INTO IOWA AND WISCONSIN. THE LOW WILL CROSS THE LAKE TONIGHT WITH SHOWERS AND PULL A COLD FRONT THROUGH WITH SHOWERS AND THUNDERSTORMS. WESTERLY FLOW BEHIND THE FRONT WILL PERSIST INTO MONDAY WHEN THE NEXT LOW APPROACHES...AT WHICH POINT WINDS TURN SOUTH AND BECOME STRONGER AND GUSTIER LATE IN THE DAY. THE ONLY OTHER CONCERN IN THE SHORT TERM IS THE WARM AND MOIST NATURE OF THE AIRMASS ASSOCIATED WITH BOTH OF THE APPROACHING LOWS. IN ADDITION TO SHOWERS AND THUNDERSTORMS...THE POTENTIAL EXISTS FOR AT LEAST PATCHY FOG TODAY AND MONDAY. LENNING && .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/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1142 PM CDT THU JUN 18 2015 .UPDATE... ISSUED AT 900 PM CDT THU JUN 18 2015 A SMALL SHORTWAVE HELPED PRODUCE LOCALIZED VERY HEAVY RAINFALL RATES BETWEEN 2-3 INCHES PER HOUR WERE REPORTED EARLIER THIS EVENING ACROSS CLAY COUNTY. WE RECEIVED REPORTS OF ROAD FLOODING AND MOST DITCHES COMPLETELY FULL. THE RAP MODELS DEPICTION OF PRECIPITABLE WATER VALUES OF 2 INCHES APPEARS ACCURATE BASED ON RAINFALL EFFICIENCY. THE SHORTWAVE WILL PROGRESS EASTWARD THIS EVENING, WITH A BREAK IN THE HEAVY RAINS POSSIBLE LATE THIS EVENING AND AFTER MIDNIGHT. HOWEVER, ADDITIONAL RAIN AND STORM DEVELOPMENT IS EXPECTED BEFORE MORNING SOUTH OF I-72 AND ESPECIALLY TOWARD I-70. POP AND WEATHER GRIDS HAVE BEEN UPDATED FOR CURRENT TRENDS ACROSS THE SOUTH AND TO REMOVE POPS FOR PEORIA AND NORTH, AS DRY AIR ENTRAINMENT FROM THE NORTHEAST SHOULD PROVIDE A RELATIVELY SHARP CUT-OFF TO THE NORTHERN EDGE OF THE PRECIP SHIELD OVERNIGHT. THE FLASH FLOOD WATCH FOR OUR SOUTHEAST 6 COUNTIES LOOKS ON TRACK FOR THE EXPECTED PRECIP FROM THE REMNANTS OF BILL THROUGH SATURDAY. UPDATED FORECAST INFO IS ALREADY AVAILABLE. && .SHORT TERM...(TONIGHT) ISSUED AT 317 PM CDT THU JUN 18 2015 NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS WITH MODERATE TO LOCALLY HEAVY RAINS SOUTHEAST OF A CANTON TO PEORIA TO MINONK LINE AT MID AFTERNOON. A FEW AREAS HAVE RECEIVED A QUICK 0.75 TO 1.25 INCHES IN LESS THAN AN HOUR IN TROPICAL AIRMASS WITH SOME WATER OVER A FEW ROADS SE OF THE IL RIVER. PRECIPITABLE WATER VALUES ARE RUNNING FROM 1.5 TO 2.25 INCHES FROM THE IL RIVER SOUTHEAST AND SUPPORT THESE HEAVY RAINS. A FRONTAL BOUNDARY JUST SE OF THE IL RIVER WILL PRESS SOUTHEAST TOWARD I-70 BY DAWN FRIDAY. MEANWHILE 1007 MB LOW PRESSURE (REMNANTS OF TROPICAL STORM BILL) OVER EAST CENTRAL OK WILL SLOWLY TRACK ENE INTO NORTH CENTRAL AR BY 12Z/FRI. MODELS GENERALLY SHOW MORE WIDESPREAD QPF FROM I-72 SOUTH TONIGHT AND HAVE HIT POPS HIGHEST IN THESE AREAS ALONG WITH HEAVIER QPF NEAR A HALF INCH WITH LOCALLY 1 INCH AMOUNTS. JUST SLIGHT CHANCES OF SHOWERS AND THUNDERSTORMS NW OF THE IL RIVER TONIGHT AND LIKELY DRY OVER FAR NW CWA OVER KNOX AND STARK COUNTIES. LOWS TONIGHT RANGE FROM LOWER 60S NORTHERN COUNTIES TO MID TO UPPER 60S FROM I-72 SOUTH. .LONG TERM...(FRIDAY THROUGH THURSDAY) ISSUED AT 315 PM CDT THU JUN 18 2015 REMNANTS OF BILL WILL CONTINUE TO EFFECT THE SOUTHERN PARTS OF THE CWA FRIDAY AND FRIDAY NIGHT. MODELS DIFFER SOME ON TIMING OF THESE REMNANTS INTO THE WEEKEND BUT SEEM TO AGREE ON TRACK/LOCATION AND HOW FAR NORTH THE HEAVIEST PCPN WILL BE THROUGH THE FRI AND FRI NIGHT PERIOD. THIS PCPN WILL BE SLOW MOVING SO HEAVY RAINFALL IS DEFINITELY A THREAT THROUGH FRI NIGHT. THE FLASH FLOOD WATCH ISSUED FOR THUR NIGHT WILL CONTINUE THROUGH FRI NIGHT. PCPN CHANCES WILL CONTINUE SATURDAY BUT THE THREAT OF FLASH FLOODING SHOULD HAVE ENDED IN THE SOUTHEAST. ONCE REMNANTS OF BILL LEAVE THE AREA TO THE EAST...A COLD FRONT WILL DROP INTO THE AREA FROM THE NORTHWEST AND BRING MORE SHOWERS AND THUNDERSTORMS TO THE AREA FOR SAT NIGHT. THIS FRONT WILL STALL OVER THE AREA FOR THE REST OF THE WEEKEND. TEMPS WILL SLOWLY RISE THROUGH THROUGH THE PERIOD...SO BY SUNDAY TEMPS WILL BE IN THE 85 TO 90 RANGE. THE FRONT THAT MOVES IN SAT NIGHT WILL REMAIN STALLED OVER THE AREA FOR THE FIRST PART OF NEXT WEEK AND THEN WOBBLE FROM SOUTH TO NORTH THROUGH MOST OF THE WEEK. THIS WILL KEEP CHANCES OF SHOWERS AND THUNDERSTORMS OVER THE CWA ALL THE WAY THROUGH WED NIGHT. BY THEN IT APPEARS THE FRONT COULD LIFT BACK NORTH SO THAT THE CHANCE OF PCPN COULD END BY THURSDAY. HOWEVER WITH THIS BEING A WEEK AWAY...THE FORECAST COULD CHANGE AND BRING THE PCPN BACK INTO THE AREA. WITH THE CWA BEING SOMEWHAT IN THE WARM SECTOR...TEMPS WILL REMAIN IN THE MID 80S TO AROUND 90 THROUGH THE PERIOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1142 PM CDT THU JUN 18 2015 SUSTAINED FORCING FOR PRECIP WILL EXIST AHEAD OF THE REMNANTS OF BILL ACROSS OUR SOUTHEAST AREA S OF I-72 THROUGH SATURDAY MORNING. PERIODIC RAIN CHANCES WILL CONTINUE FOR THE SOUTHERN TERMINALS OF SPI, DEC AND POSSIBLY CMI. PIA AND BMI HAVE A GOOD CHANCE OF REMAINING DRY OVER THE NEXT 24 HOURS, AS THEY RESIDE NORTH OF THE STATIONARY FRONTAL BOUNDARY. INITIAL CONCERNS OVERNIGHT WILL BE CEILINGS DROPPING TO IFR BELOW 1K FEET, AND POTENTIAL FOR SOME FOG. WE DON`T EXPECT WIDESPREAD DENSE FOG DUE TO A BLANKET OF CLOUDS, BUT MVFR FOG LOOKS LIKELY BASED ON THE SATURATED BOUNDARY LAYER AND LIGHT WINDS ALREADY IN PLACE. IFR CEILINGS COULD LINGER THROUGH MID MORNING, BUT THEN SHOULD LIFT TO MVFR AS VIS IMPROVES ABOVE MVFR AS WELL. PRECIP CHANCES ARE FORECAST TO DIMINISH SLIGHTLY FRIDAY EVENING, SO WE DID NOT MENTION ANY RAIN AFTER 00Z/7PM. WINDS HAVE BECOME EAST AT ALL BUT CMI, WHERE WINDS WENT SOUTHEAST UNDER THE FRONTAL BOUNDARY. THE FRONT IS PROJECTED TO REMAIN IN PLACE THROUGH THE DAY TOMORROW, SO WIND DIRECTIONS WILL NOT CHANGE MUCH FROM TONIGHT. && .ILX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH LATE FRIDAY NIGHT FOR ILZ066>068- 071>073. && $$ UPDATE...SHIMON SHORT TERM...25 LONG TERM...AUTEN AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1018 PM EDT SAT JUN 20 2015 .UPDATE... THE NEAR TERM SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 328 PM EDT SAT JUN 20 2015 A REMNANT TROPICAL SYSTEM WILL CONTINUE TO PUSH EASTWARD INTO TONIGHT. THEN A FRONTAL SYSTEM WILL MOVE INTO THE AREA EARLY SUNDAY AND LINGER INTO NEXT WEEK...RESULTING IN MORE PERIODIC THUNDERSTORM CHANCES. && .NEAR TERM /REST OF TONIGHT/... ISSUED AT 1007 PM EDT SAT JUN 20 2015 UPDATE... CURRENT FORECAST IS ON TRACK...SO NO CHANGES. LATEST RADAR MOSAIC SHOWS WIDESPREAD SHOWERS AND THUNDERSTORMS CURRENTLY TRACKING ACROSS CENTRAL AND NORTHERN ILLINOIS. NORTHWESTERN PORTIONS OF CENTRAL INDIANA COULD START SEEING SOME PRECIP WITHIN THE NEXT FEW HOURS WITH THE BULK OF THE CONVECTION MOVING IN AFTER MIDNIGHT. THE ONLY COUNTY STILL UNDER SLIGHT RISK OF SEVERE WEATHER IS WARREN COUNTY. UPDATED GRIDS HAVE BEEN SENT. PREVIOUS DISCUSSION... AN UPPER LEVEL SYSTEM IS SLOWLY MOVING SOUTHEASTWARD ACROSS PORTIONS OF EASTERN IOWA AND WESTERN WISCONSIN AND IS EXPECTED TO APPROACH THE NORTHWEST COUNTIES OF CENTRAL INDIANA AROUND MIDNIGHT TONIGHT. GUIDANCE SEEMS TO BE IN AGREEMENT WITH INITIALLY SHOWING THIS SYSTEM TO BE QUITE PROGRESSIVE AS IT MOVES TOWARD THE CENTRAL CWA DURING THE WEE EARLY HOURS SUNDAY MORNING...THEN BEGINS TO SLOW DOWN AND POSSIBLY EVEN STALL OUT AS IT DROPS SOUTH OF THE I 70 CORRIDOR. TRIED TO DEPICT POPS IN THE FORECAST AS IN THE HRRR AND OTHER NEAR TERM GUIDANCE WITH HIGHER POPS ACROSS THE NORTHWEST SHORTLY AFTER MIDNIGHT...THEN SLOWLY MOVING THIS SYSTEM SOUTHEAST ACROSS THE FORECAST AREA OVERNIGHT TIL IT REACHES THE SOUTHERN TWO TO THREE TIERS OF COUNTIES OF THE CWA AND EITHER SLOWS DOWN...WEAKENS...OR ALL TOGETHER JUST STALLS OUT AND LATER WEAKENS. SEVERE WX THREAT FOR TONIGHT VERY MARGINAL WITH ONLY WARREN COUNTY INCLUDED IN SPC/S DAY 1 SLIGHT RISK. SO SOME OF THESE STORMS DO HAVE THE POTENTIAL TO BE STRONG WITH DAMAGING WINDS AND HAIL AS THE MAIN THREATS. AND HEAVY DOWNPOURS AND CLOUD-TO-GROUND LIGHTNING NOT TO BE DISCOUNTED IN ANY THUNDERSTORMS. A BLEND OF GUIDANCE FOR LOW TEMPERATURES TONIGHT SEEMS REASONABLE AS THE NUMBERS ARE COMING IN SIMILAR FOR LOWS AROUND 70. && .SHORT TERM /SUNDAY THROUGH TUESDAY/... ISSUED AT 328 PM EDT SAT JUN 20 2015 A COLD FRONT WILL BEGIN MOVING INTO THE AREA LATER SUNDAY AFTERNOON FOLLOWING THE UPPER LEVEL SYSTEM MOVING SOUTHEAST ACROSS THE FORECAST AREA THAT MORNING. STEEP LAPSE RATES AND SUFFICIENT DEEP LAYER SHEAR SUGGEST AN ORGANIZED SEVERE THREAT IS POSSIBLE WITH THE FRONT...AND THE MAIN FOCUS FOR ANY STRONG TO SEVERE STORMS AS BEEN SHUNTED SOUTHWARD BASED ON THE FASTER TIMING OF THIS SYSTEM...SO NOW THE ONLY COUNTIES IN THE DAY 2 SLIGHT RISK FOR KIND CWA LIE JUST SOUTH OF THAT COMMON DIVIDING LINE THAT IT THE I 70 CORRIDOR. BASICALLY KEEPING HIGHER CHANCE POPS ACROSS THIS AREA TO THE SOUTH AND ONLY SLIGHT CHANCE TO ZERO POPS ACROSS THE NORTHERN COUNTIES. LATER SUNDAY NIGHT THE FRONT MAY SAG FAR ENOUGH TO THE SOUTH FOR A LULL IN THE THUNDERSTORM THREAT...BUT WILL KEEP SOME SMALL/WEAK CHANCES FOR POPS GOING SUNDAY NIGHT IN CASE THE FRONT ENDS UP MORE STATIONARY. APPEARS THE FRONT WILL BEGIN DRIFTING BACK TO THE NORTH DURING MONDAY AND TUESDAY SO WILL CONTINUE TO GO WITH PERIODIC CHANCES FOR SHOWERS AND THUNDERSTORMS BOTH DAYS. ALSO BASED ON PROGGED LOW LEVEL THICKNESSES...APPEARS TEMPERATURES AND DEW POINTS WILL BE GETTING INTO THAT UNCOMFORTABLE RANGE AGAIN WITH DEW POINTS IN THE MID 70S (OR HIGHER EVEN?) POSSIBLE...AND HIGHS IN THE MID/UPPER 80S TO AROUND 90 ACROSS THE SOUTHERN HALF OF THE CWA. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... ISSUED AT 216 PM EDT SAT JUN 20 2015 MODELS ARE CLOSE ENOUGH THAT THE SUPERBLEND INITIALIZATION WAS ACCEPTED FOR MOST ITEMS. AN UPPER RIDGE WILL REMAIN ACROSS THE SOUTH AND SOUTHWEST USA DURING MUCH OF THE LONG TERM...SETTING UP A NORTHWEST FLOW ALOFT ACROSS CENTRAL INDIANA. BY NEXT WEEKEND A TROUGH MAY DIG INTO THE AREA. THIS FLOW WILL ALLOW A SURFACE FRONT TO STALL OUT ACROSS CENTRAL INDIANA THROUGH THE EXTENDED. AS UPPER WAVES INTERACT WITH THE FRONT...SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE EACH DAY. MORE RAIN WILL BE POSSIBLE WITH THE UPPER TROUGH SATURDAY. TEMPERATURES WILL REMAIN NEAR TO ABOVE AVERAGE THROUGH MUCH OF THE PERIOD...WITH SOME COOLER CONDITIONS PERHAPS ARRIVING FOR NEXT WEEKEND. && .AVIATION /DISCUSSION FOR 210000Z TAF ISSUANCE/... ISSUED AT 636 PM EDT SAT JUN 20 2015 MODEL RH TIME SECTIONS WERE SHOWING AN INCREASE IN NEAR SURFACE MOISTURE TONIGHT AFTER 04Z. HOWEVER...NOT CONFIDENT IN STRATUS CEILINGS AS APPROACHING COLD FRONT AND POSSIBLE MCS SHOULD ERODE THE LOW LEVEL INVERSION PER RAP SOUNDINGS. SO...WILL GO WITH MVFR THROUGH 01Z AND THEN IT SHOULD SCATTER BEFORE THE STORMS MOVE IN OVERNIGHT. WILL GO WITH VCTS AFTER 04Z AT LAF AND HUF AND AFTER 06Z AT IND AND BMG. COULD CERTAINLY SEE MVFR CEILINGS IN THUNDERSTORMS...BUT FOR NOW WITH TIMING AND EVOLUTION OF IOWA STORMS STILL A BIT UP IN THE AIR...WILL JUST KEEP FLYING CONDITIONS AS VFR AND TRY AND FINE TUNE TIMING OF ANY WORSE CONDITIONS WITH THE 06Z TAF ISSUANCE OR LATE EVENING AMENDMENTS. WILL TIME THE COLD FRONT TO LAF AROUND 15Z SUNDAY...IND AND HUF AT 18Z AND BMG AT 00Z. SOUTHWEST WINDS 10 TO 15 KNOTS ON SUNDAY WILL SHIFT TO NORTHWEST BEHIND THE FRONT. WINDS TONIGHT WILL BE SOUTHWEST LESS THAN 10 KNOTS. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...SMF NEAR TERM...SMF/TDUD SHORT TERM...SMF LONG TERM...50 AVIATION...MK 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
636 PM EDT SAT JUN 20 2015 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 328 PM EDT SAT JUN 20 2015 A REMNANT TROPICAL SYSTEM WILL CONTINUE TO PUSH EASTWARD INTO TONIGHT. THEN A FRONTAL SYSTEM WILL MOVE INTO THE AREA EARLY SUNDAY AND LINGER INTO NEXT WEEK...RESULTING IN MORE PERIODIC THUNDERSTORM CHANCES. && .NEAR TERM /TONIGHT/... ISSUED AT 328 PM EDT SAT JUN 20 2015 AN UPPER LEVEL SYSTEM IS SLOWLY MOVING SOUTHEASTWARD ACROSS PORTIONS OF EASTERN IOWA AND WESTERN WISCONSIN AND IS EXPECTED TO APPROACH THE NORTHWEST COUNTIES OF CENTRAL INDIANA AROUND MIDNIGHT TONIGHT. GUIDANCE SEEMS TO BE IN AGREEMENT WITH INITIALLY SHOWING THIS SYSTEM TO BE QUITE PROGRESSIVE AS IT MOVE TOWARD THE CENTRAL CWA DURING THE WEE EARLY HOURS SUNDAY MORNING...THEN BEGINS TO SLOW DOWN AND POSSIBLY EVEN STALL OUT AS IT DROPS SOUTH OF THE I 70 CORRIDOR. TRIED TO DEPICT POPS IN THE FORECAST AS IN THE HRRR AND OTHER NEAR TERM GUIDANCE WITH HIGHER POPS ACROSS THE NORTHWEST SHORTLY AFTER MIDNIGHT...THEN SLOWLY MOVING THIS SYSTEM SOUTHEAST ACROSS THE FORECAST AREA OVERNIGHT TIL IT REACH THE SOUTHERN TWO TO THREE TIERS OF COUNTIES OF THE CWA AND EITHER SLOWS DOWN...WEAKENS...OR ALL TOGETHER JUST STALLS OUT AND LATER WEAKENS. SEVERE WX THREAT FOR TONIGHT VERY MARGINAL WITH ONLY WARREN COUNTY INCLUDED IN SPC/S DAY 1 SLIGHT RISK. SO SOME OF THESE STORMS DO HAVE THE POTENTIAL TO BE STRONG WITH DAMAGING WINDS AND HAIL AS THE MAIN THREATS. AND HEAVY DOWNPOURS AND CLOUD-TO-GROUND LIGHTNING NOT TO BE DISCOUNTED IN ANY THUNDERSTORMS. A BLEND OF GUIDANCE FOR LOW TEMPERATURES TONIGHT SEEMS REASONABLE AS THE NUMBERS ARE COMING IN SIMILAR FOR LOWS AROUND 70. && .SHORT TERM /SUNDAY THROUGH TUESDAY/... ISSUED AT 328 PM EDT SAT JUN 20 2015 A COLD FRONT WILL BEGIN MOVING INTO THE AREA LATER SUNDAY AFTERNOON FOLLOWING THE UPPER LEVEL SYSTEM MOVING SOUTHEAST ACROSS THE FORECAST AREA THAT MORNING. STEEP LAPSE RATES AND SUFFICIENT DEEP LAYER SHEAR SUGGEST AN ORGANIZED SEVERE THREAT IS POSSIBLE WITH THE FRONT...AND THE MAIN FOCUS FOR ANY STRONG TO SEVERE STORMS AS BEEN SHUNTED SOUTHWARD BASED ON THE FASTER TIMING OF THIS SYSTEM...SO NOW THE ONLY COUNTIES IN THE DAY 2 SLIGHT RISK FOR KIND CWA LIE JUST SOUTH OF THAT COMMON DIVIDING LINE THAT IT THE I 70 CORRIDOR. BASICALLY KEEPING HIGHER CHANCE POPS ACROSS THIS AREA TO THE SOUTH AND ONLY SLIGHT CHANCE TO ZERO POPS ACROSS THE NORTHERN COUNTIES. LATER SUNDAY NIGHT THE FRONT MAY SAG FAR ENOUGH TO THE SOUTH FOR A LULL IN THE THUNDERSTORM THREAT...BUT WILL KEEP SOME SMALL/WEAK CHANCES FOR POPS GOING SUNDAY NIGHT IN CASE THE FRONT ENDS UP MORE STATIONARY. APPEARS THE FRONT WILL BEGIN DRIFTING BACK TO THE NORTH DURING MONDAY AND TUESDAY SO WILL CONTINUE TO GO WITH PERIODIC CHANCES FOR SHOWERS AND THUNDERSTORMS BOTH DAYS. ALSO BASED ON PROGGED LOW LEVEL THICKNESSES...APPEARS TEMPERATURES AND DEW POINTS WILL BE GETTING INTO THAT UNCOMFORTABLE RANGE AGAIN WITH DEW POINTS IN THE MID 70S (OR HIGHER EVEN?) POSSIBLE...AND HIGHS IN THE MID/UPPER 80S TO AROUND 90 ACROSS THE SOUTHERN HALF OF THE CWA. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... ISSUED AT 216 PM EDT SAT JUN 20 2015 MODELS ARE CLOSE ENOUGH THAT THE SUPERBLEND INITIALIZATION WAS ACCEPTED FOR MOST ITEMS. AN UPPER RIDGE WILL REMAIN ACROSS THE SOUTH AND SOUTHWEST USA DURING MUCH OF THE LONG TERM...SETTING UP A NORTHWEST FLOW ALOFT ACROSS CENTRAL INDIANA. BY NEXT WEEKEND A TROUGH MAY DIG INTO THE AREA. THIS FLOW WILL ALLOW A SURFACE FRONT TO STALL OUT ACROSS CENTRAL INDIANA THROUGH THE EXTENDED. AS UPPER WAVES INTERACT WITH THE FRONT...SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE EACH DAY. MORE RAIN WILL BE POSSIBLE WITH THE UPPER TROUGH SATURDAY. TEMPERATURES WILL REMAIN NEAR TO ABOVE AVERAGE THROUGH MUCH OF THE PERIOD...WITH SOME COOLER CONDITIONS PERHAPS ARRIVING FOR NEXT WEEKEND. && .AVIATION /DISCUSSION FOR 210000Z TAF ISSUANCE/... ISSUED AT 636 PM EDT SAT JUN 20 2015 MODEL RH TIME SECTIONS WERE SHOWING AN INCREASE IN NEAR SURFACE MOISTURE TONIGHT AFTER 04Z. HOWEVER...NOT CONFIDENT IN STRATUS CEILINGS AS APPROACHING COLD FRONT AND POSSIBLE MCS SHOULD ERODE THE LOW LEVEL INVERSION PER RAP SOUNDINGS. SO...WILL GO WITH MVFR THROUGH 01Z AND THEN IT SHOULD SCATTER BEFORE THE STORMS MOVE IN OVERNIGHT. WILL GO WITH VCTS AFTER 04Z AT LAF AND HUF AND AFTER 06Z AT IND AND BMG. COULD CERTAINLY SEE MVFR CEILINGS IN THUNDERSTORMS...BUT FOR NOW WITH TIMING AND EVOLUTION OF IOWA STORMS STILL A BIT UP IN THE AIR...WILL JUST KEEP FLYING CONDITIONS AS VFR AND TRY AND FINE TUNE TIMING OF ANY WORSE CONDITIONS WITH THE 06Z TAF ISSUANCE OR LATE EVENING AMENDMENTS. WILL TIME THE COLD FRONT TO LAF AROUND 15Z SUNDAY...IND AND HUF AT 18Z AND BMG AT 00Z. SOUTHWEST WINDS 10 TO 15 KNOTS ON SUNDAY WILL SHIFT TO NORTHWEST BEHIND THE FRONT. WINDS TONIGHT WILL BE SOUTHWEST LESS THAN 10 KNOTS. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...SMF NEAR TERM...SMF SHORT TERM...SMF LONG TERM...50 AVIATION...MK 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
430 PM EDT SAT JUN 20 2015 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 328 PM EDT SAT JUN 20 2015 A REMNANT TROPICAL SYSTEM WILL CONTINUE TO PUSH EASTWARD INTO TONIGHT. THEN A FRONTAL SYSTEM WILL MOVE INTO THE AREA EARLY SUNDAY AND LINGER INTO NEXT WEEK...RESULTING IN MORE PERIODIC THUNDERSTORM CHANCES. && .NEAR TERM /TONIGHT/... ISSUED AT 328 PM EDT SAT JUN 20 2015 AN UPPER LEVEL SYSTEM IS SLOWLY MOVING SOUTHEASTWARD ACROSS PORTIONS OF EASTERN IOWA AND WESTERN WISCONSIN AND IS EXPECTED TO APPROACH THE NORTHWEST COUNTIES OF CENTRAL INDIANA AROUND MIDNIGHT TONIGHT. GUIDANCE SEEMS TO BE IN AGREEMENT WITH INITIALLY SHOWING THIS SYSTEM TO BE QUITE PROGRESSIVE AS IT MOVE TOWARD THE CENTRAL CWA DURING THE WEE EARLY HOURS SUNDAY MORNING...THEN BEGINS TO SLOW DOWN AND POSSIBLY EVEN STALL OUT AS IT DROPS SOUTH OF THE I 70 CORRIDOR. TRIED TO DEPICT POPS IN THE FORECAST AS IN THE HRRR AND OTHER NEAR TERM GUIDANCE WITH HIGHER POPS ACROSS THE NORTHWEST SHORTLY AFTER MIDNIGHT...THEN SLOWLY MOVING THIS SYSTEM SOUTHEAST ACROSS THE FORECAST AREA OVERNIGHT TIL IT REACH THE SOUTHERN TWO TO THREE TIERS OF COUNTIES OF THE CWA AND EITHER SLOWS DOWN...WEAKENS...OR ALL TOGETHER JUST STALLS OUT AND LATER WEAKENS. SEVERE WX THREAT FOR TONIGHT VERY MARGINAL WITH ONLY WARREN COUNTY INCLUDED IN SPC/S DAY 1 SLIGHT RISK. SO SOME OF THESE STORMS DO HAVE THE POTENTIAL TO BE STRONG WITH DAMAGING WINDS AND HAIL AS THE MAIN THREATS. AND HEAVY DOWNPOURS AND CLOUD-TO-GROUND LIGHTNING NOT TO BE DISCOUNTED IN ANY THUNDERSTORMS. A BLEND OF GUIDANCE FOR LOW TEMPERATURES TONIGHT SEEMS REASONABLE AS THE NUMBERS ARE COMING IN SIMILAR FOR LOWS AROUND 70. && .SHORT TERM /SUNDAY THROUGH TUESDAY/... ISSUED AT 328 PM EDT SAT JUN 20 2015 A COLD FRONT WILL BEGIN MOVING INTO THE AREA LATER SUNDAY AFTERNOON FOLLOWING THE UPPER LEVEL SYSTEM MOVING SOUTHEAST ACROSS THE FORECAST AREA THAT MORNING. STEEP LAPSE RATES AND SUFFICIENT DEEP LAYER SHEAR SUGGEST AN ORGANIZED SEVERE THREAT IS POSSIBLE WITH THE FRONT...AND THE MAIN FOCUS FOR ANY STRONG TO SEVERE STORMS AS BEEN SHUNTED SOUTHWARD BASED ON THE FASTER TIMING OF THIS SYSTEM...SO NOW THE ONLY COUNTIES IN THE DAY 2 SLIGHT RISK FOR KIND CWA LIE JUST SOUTH OF THAT COMMON DIVIDING LINE THAT IT THE I 70 CORRIDOR. BASICALLY KEEPING HIGHER CHANCE POPS ACROSS THIS AREA TO THE SOUTH AND ONLY SLIGHT CHANCE TO ZERO POPS ACROSS THE NORTHERN COUNTIES. LATER SUNDAY NIGHT THE FRONT MAY SAG FAR ENOUGH TO THE SOUTH FOR A LULL IN THE THUNDERSTORM THREAT...BUT WILL KEEP SOME SMALL/WEAK CHANCES FOR POPS GOING SUNDAY NIGHT IN CASE THE FRONT ENDS UP MORE STATIONARY. APPEARS THE FRONT WILL BEGIN DRIFTING BACK TO THE NORTH DURING MONDAY AND TUESDAY SO WILL CONTINUE TO GO WITH PERIODIC CHANCES FOR SHOWERS AND THUNDERSTORMS BOTH DAYS. ALSO BASED ON PROGGED LOW LEVEL THICKNESSES...APPEARS TEMPERATURES AND DEW POINTS WILL BE GETTING INTO THAT UNCOMFORTABLE RANGE AGAIN WITH DEW POINTS IN THE MID 70S (OR HIGHER EVEN?) POSSIBLE...AND HIGHS IN THE MID/UPPER 80S TO AROUND 90 ACROSS THE SOUTHERN HALF OF THE CWA. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... ISSUED AT 216 PM EDT SAT JUN 20 2015 MODELS ARE CLOSE ENOUGH THAT THE SUPERBLEND INITIALIZATION WAS ACCEPTED FOR MOST ITEMS. AN UPPER RIDGE WILL REMAIN ACROSS THE SOUTH AND SOUTHWEST USA DURING MUCH OF THE LONG TERM...SETTING UP A NORTHWEST FLOW ALOFT ACROSS CENTRAL INDIANA. BY NEXT WEEKEND A TROUGH MAY DIG INTO THE AREA. THIS FLOW WILL ALLOW A SURFACE FRONT TO STALL OUT ACROSS CENTRAL INDIANA THROUGH THE EXTENDED. AS UPPER WAVES INTERACT WITH THE FRONT...SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE EACH DAY. MORE RAIN WILL BE POSSIBLE WITH THE UPPER TROUGH SATURDAY. TEMPERATURES WILL REMAIN NEAR TO ABOVE AVERAGE THROUGH MUCH OF THE PERIOD...WITH SOME COOLER CONDITIONS PERHAPS ARRIVING FOR NEXT WEEKEND. && .AVIATION /DISCUSSION FOR 202100Z IND TAF UPDATE/... ISSUED AT 430 PM EDT SAT JUN 20 2015 DELAYED VFR CEILINGS TIL 23Z PER TRENDS. PREVIOUS DISCUSSION FOLLOWS... ISSUED AT 1243 PM EDT SAT JUN 20 2015 MVFR CONDITIONS WILL GIVE WAY TO VFR BY LATE AFTERNOON. GENERALLY VFR AFTERWARD WITH POTENTIAL FOR CONVECTION OVERNIGHT INTO SUNDAY. STUBBORN MVFR DECK WILL REMAIN ACROSS THE SITES FOR A WHILE THIS AFTERNOON...BUT IT WILL GRADUALLY LIFT TO VFR BY LATE AFTERNOON. A THUNDERSTORM COMPLEX MAY MOVE INTO THE AREA AFTER 05Z OR SO TONIGHT...THEN MORE CONVECTION MAY ARRIVE INTO THE DAY SUNDAY AS A COLD FRONT MOVES IN. PLENTY OF UNCERTAINTY ON TIMING AND COVERAGE SO CONTINUED JUST A VCTS MENTION AS IN PREVIOUS FORECASTS. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...SMF NEAR TERM...SMF SHORT TERM...SMF LONG TERM...50 AVIATION...50/MK 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
333 PM EDT SAT JUN 20 2015 .UPDATE... THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 328 PM EDT SAT JUN 20 2015 A REMNANT TROPICAL SYSTEM WILL CONTINUE TO PUSH EASTWARD INTO TONIGHT. THEN A FRONTAL SYSTEM WILL MOVE INTO THE AREA EARLY SUNDAY AND LINGER INTO NEXT WEEK...RESULTING IN MORE PERIODIC THUNDERSTORM CHANCES. && .NEAR TERM /TONIGHT/... ISSUED AT 328 PM EDT SAT JUN 20 2015 AN UPPER LEVEL SYSTEM IS SLOWLY MOVING SOUTHEASTWARD ACROSS PORTIONS OF EASTERN IOWA AND WESTERN WISCONSIN AND IS EXPECTED TO APPROACH THE NORTHWEST COUNTIES OF CENTRAL INDIANA AROUND MIDNIGHT TONIGHT. GUIDANCE SEEMS TO BE IN AGREEMENT WITH INITIALLY SHOWING THIS SYSTEM TO BE QUITE PROGRESSIVE AS IT MOVE TOWARD THE CENTRAL CWA DURING THE WEE EARLY HOURS SUNDAY MORNING...THEN BEGINS TO SLOW DOWN AND POSSIBLY EVEN STALL OUT AS IT DROPS SOUTH OF THE I 70 CORRIDOR. TRIED TO DEPICT POPS IN THE FORECAST AS IN THE HRRR AND OTHER NEAR TERM GUIDANCE WITH HIGHER POPS ACROSS THE NORTHWEST SHORTLY AFTER MIDNIGHT...THEN SLOWLY MOVING THIS SYSTEM SOUTHEAST ACROSS THE FORECAST AREA OVERNIGHT TIL IT REACH THE SOUTHERN TWO TO THREE TIERS OF COUNTIES OF THE CWA AND EITHER SLOWS DOWN...WEAKENS...OR ALL TOGETHER JUST STALLS OUT AND LATER WEAKENS. SEVERE WX THREAT FOR TONIGHT VERY MARGINAL WITH ONLY WARREN COUNTY INCLUDED IN SPC/S DAY 1 SLIGHT RISK. SO SOME OF THESE STORMS DO HAVE THE POTENTIAL TO BE STRONG WITH DAMAGING WINDS AND HAIL AS THE MAIN THREATS. AND HEAVY DOWNPOURS AND CLOUD-TO-GROUND LIGHTNING NOT TO BE DISCOUNTED IN ANY THUNDERSTORMS. A BLEND OF GUIDANCE FOR LOW TEMPERATURES TONIGHT SEEMS REASONABLE AS THE NUMBERS ARE COMING IN SIMILAR FOR LOWS AROUND 70. && .SHORT TERM /SUNDAY THROUGH TUESDAY/... ISSUED AT 328 PM EDT SAT JUN 20 2015 A COLD FRONT WILL BEGIN MOVING INTO THE AREA LATER SUNDAY AFTERNOON FOLLOWING THE UPPER LEVEL SYSTEM MOVING SOUTHEAST ACROSS THE FORECAST AREA THAT MORNING. STEEP LAPSE RATES AND SUFFICIENT DEEP LAYER SHEAR SUGGEST AN ORGANIZED SEVERE THREAT IS POSSIBLE WITH THE FRONT...AND THE MAIN FOCUS FOR ANY STRONG TO SEVERE STORMS AS BEEN SHUNTED SOUTHWARD BASED ON THE FASTER TIMING OF THIS SYSTEM...SO NOW THE ONLY COUNTIES IN THE DAY 2 SLIGHT RISK FOR KIND CWA LIE JUST SOUTH OF THAT COMMON DIVIDING LINE THAT IT THE I 70 CORRIDOR. BASICALLY KEEPING HIGHER CHANCE POPS ACROSS THIS AREA TO THE SOUTH AND ONLY SLIGHT CHANCE TO ZERO POPS ACROSS THE NORTHERN COUNTIES. LATER SUNDAY NIGHT THE FRONT MAY SAG FAR ENOUGH TO THE SOUTH FOR A LULL IN THE THUNDERSTORM THREAT...BUT WILL KEEP SOME SMALL/WEAK CHANCES FOR POPS GOING SUNDAY NIGHT IN CASE THE FRONT ENDS UP MORE STATIONARY. APPEARS THE FRONT WILL BEGIN DRIFTING BACK TO THE NORTH DURING MONDAY AND TUESDAY SO WILL CONTINUE TO GO WITH PERIODIC CHANCES FOR SHOWERS AND THUNDERSTORMS BOTH DAYS. ALSO BASED ON PROGGED LOW LEVEL THICKNESSES...APPEARS TEMPERATURES AND DEW POINTS WILL BE GETTING INTO THAT UNCOMFORTABLE RANGE AGAIN WITH DEW POINTS IN THE MID 70S (OR HIGHER EVEN?) POSSIBLE...AND HIGHS IN THE MID/UPPER 80S TO AROUND 90 ACROSS THE SOUTHERN HALF OF THE CWA. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... ISSUED AT 216 PM EDT SAT JUN 20 2015 MODELS ARE CLOSE ENOUGH THAT THE SUPERBLEND INITIALIZATION WAS ACCEPTED FOR MOST ITEMS. AN UPPER RIDGE WILL REMAIN ACROSS THE SOUTH AND SOUTHWEST USA DURING MUCH OF THE LONG TERM...SETTING UP A NORTHWEST FLOW ALOFT ACROSS CENTRAL INDIANA. BY NEXT WEEKEND A TROUGH MAY DIG INTO THE AREA. THIS FLOW WILL ALLOW A SURFACE FRONT TO STALL OUT ACROSS CENTRAL INDIANA THROUGH THE EXTENDED. AS UPPER WAVES INTERACT WITH THE FRONT...SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE EACH DAY. MORE RAIN WILL BE POSSIBLE WITH THE UPPER TROUGH SATURDAY. TEMPERATURES WILL REMAIN NEAR TO ABOVE AVERAGE THROUGH MUCH OF THE PERIOD...WITH SOME COOLER CONDITIONS PERHAPS ARRIVING FOR NEXT WEEKEND. && .AVIATION /DISCUSSION FOR 201800Z TAF ISSUANCE/... ISSUED AT 1243 PM EDT SAT JUN 20 2015 MVFR CONDITIONS WILL GIVE WAY TO VFR BY LATE AFTERNOON. GENERALLY VFR AFTERWARD WITH POTENTIAL FOR CONVECTION OVERNIGHT INTO SUNDAY. STUBBORN MVFR DECK WILL REMAIN ACROSS THE SITES FOR A WHILE THIS AFTERNOON...BUT IT WILL GRADUALLY LIFT TO VFR BY LATE AFTERNOON. A THUNDERSTORM COMPLEX MAY MOVE INTO THE AREA AFTER 05Z OR SO TONIGHT...THEN MORE CONVECTION MAY ARRIVE INTO THE DAY SUNDAY AS A COLD FRONT MOVES IN. PLENTY OF UNCERTAINTY ON TIMING AND COVERAGE SO CONTINUED JUST A VCTS MENTION AS IN PREVIOUS FORECASTS. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...SMF NEAR TERM...SMF SHORT TERM...SMF LONG TERM...50 AVIATION...50 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 DES MOINES IA
650 PM CDT SAT JUN 20 2015 .UPDATE... ISSUED AT 645 PM CDT SAT JUN 20 2015 COLD FRONT MAKING RAPID PROGRESS TO THE SOUTHEAST WITH THE AIRMASS BECOMING MORE STABLE BEHIND THE FRONT. EXPECT THE STORMS TO TRANSITION TO A BIG WIND THREAT AS THEY PUSH TO THE SOUTHEAST BUT FOR CENTRAL IOWA...STORMS SHOULD EXIT THE REGION BY 02Z WITH CLEARING SKIES ACROSS THE EAST BY 03Z. THE REMAINDER OF TONIGHT WILL BE QUIET. && .SHORT TERM /TONIGHT/... ISSUED AT 224 PM CDT SAT JUN 20 2015 FORECAST PROBLEM FOR TONIGHT WILL BE THUNDERSTORM DEVELOPMENT ALONG A FRONTAL BOUNDARY MAKING ITS WAY ACROSS CENTRAL IOWA. AT 20Z THE FRONTAL BOUNDARY WAS LOCATED ROUGHLY FROM OMAHA TO ATLANTIC THEN NORTHEAST TO FORT DODGE TO FOREST CITY. THE MAIN AREA OF CONCERN WILL BE THE I-80 CORRIDOR AND ESPECIALLY SOUTH WHERE IT HAS BEEN SUNNY ALL DAY AND HAS BEEN ABLE TO REALLY DESTABILIZE. MESOANALYSIS SHOWS AN UNCAPPED ENVIRONMENT WITH 5000-6000 CAPES ACROSS THE AREAS WEST OF I-35 AND SOUTH OF I-80. ONCE THE FRONT PUSHES TO THIS AREA THUNDERSTORMS SHOULD RAPIDLY DEVELOP AND BECOME SEVERE. AT THIS TIME IT LOOKS LIKE THE DES MOINES METRO AREA WILL BE ON THE WESTERN FRINGE OF THE DEVELOPMENT SO BETWEEN 21Z AND 00Z WE SHOULD SEE STORMS BLOW UP. STRONG LOW LEVEL SHEAR IN THE VICINITY OF THE FRONT WILL ALLOW FOR ROBUST UPDRAFTS AND THE POTENTIAL FOR A FEW TORNADOES. LARGE HAIL WILL ALSO BE A THREAT. THE STORMS WILL EVENTUALLY EVOLVE INTO A WIND THREAT AS WELL BUT THAT MAY BE EAST/SOUTH OF OUR AREA. THE STORMS SHOULD BE EAST OF THE AREA BY 06Z HOWEVER THE HRRR IS INDICATING A SECONDARY LINE DEVELOPING ALONG THE 850 FRONT AND PUSHING SOUTH BEFORE STALLING NEAR THE IA/MO BORDER. IF THIS HAPPENS SOUTHERN IOWA WILL BE GETTING SOME HEAVY RAINFALL AMOUNTS. AT THIS TIME CONFIDENCE IS LOW ON THAT SECOND SHOT OF RAINFALL SO I HAVE GRIDS CLEARING AFTER 06Z. .LONG TERM /SUNDAY THROUGH SATURDAY/... ISSUED AT 224 PM CDT SAT JUN 20 2015 SURFACE HIGH PRESSURE WILL BUILD ACROSS THE MIDWEST INTO THE OHIO VALLEY ON SUNDAY. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO BE SOUTH OF IOWA IN THE MORNING. A SHORTWAVE MOVING THROUGH THE WESTERLY FLOW ALOFT ACROSS THE NORTHERN PLAINS WILL STRENGTHEN A SURFACE LOW IN THE DAKOTAS SUNDAY AFTERNOON. THE PRESSURE GRADIENT IS EXPECTED TO TIGHTEN WITH SOUTHERLY SURFACE FLOW LIFTING A WARM FRONT NORTH. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP NEAR THE FRONT LATE IN THE DAY WITH CONVECTION BECOMING MORE WIDESPREAD DURING THE EVENING AND OVERNIGHT HOURS. INSTABILITY AND DEEP LAYER SHEAR WILL BE SUFFICIENT FOR A FEW STRONG TO SEVERE THUNDERSTORMS WITH DAMAGING WINDS AND HAIL THE PRIMARY HAZARDS. PRECIPITATION WILL END FROM SOUTHWEST TO NORTHEAST MONDAY. WARM FRONT LOOKS TO SETUP ACROSS NORTHERN KANSAS AND MISSOURI ON TUESDAY...GRADUALLY LIFTING NORTH AND PROVIDING A FOCUS FOR ADDITIONAL SHOWERS AND THUNDERSTORMS. THE LATE AFTERNOON THROUGH THE OVERNIGHT HOURS IS THE MOST LIKELY TIMEFRAME FOR PRECIPITATION. ANOTHER SHORTWAVE TROUGH MOVES THROUGH THE NORTHERN PLAINS INTO THE MIDWEST ON WEDNESDAY. OCCASIONAL SHOWERS AND THUNDERSTORMS COULD FESTER THROUGH THE DAY AIDED BY MULTIPLE SHORTWAVES MOVING THROUGH THE UPPER FLOW AND NEARBY FRONTAL BOUNDARY. PATTERN LOOKS TO REMAIN ACTIVE THROUGH THE END OF THE WEEK INTO NEXT WEEKEND WITH WEST AND NORTHWEST UPPER FLOW...MULTIPLE OUTFLOW BOUNDARIES AND A SURFACE FRONT SUPPORTING CHANCES FOR THUNDERSTORMS. && .AVIATION...21/00Z ISSUED AT 645 PM CDT SAT JUN 20 2015 COLD FRONT PUSHING RAPIDLY SOUTHEAST ACROSS TAF LOCATIONS WITH CLEARING BEHIND THE FRONT. EXPECT STORMS TO CLEAR KOTM BY 01Z WITH VFR CONDITIONS BY 02Z. VFR CONDITIONS EXPECTED THROUGH THE REMAINDER OF THE TAF FORECAST WITH SFC WIND SWITCHING AROUND TO THE SOUTH AFT 16Z. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...FAB SHORT TERM...FAB LONG TERM...ANGLE AVIATION...FAB
AREA FORECAST DISCUSSION
NWS DES MOINES IA
346 PM CDT SAT JUN 20 2015 .SHORT TERM /TONIGHT/... ISSUED AT 224 PM CDT SAT JUN 20 2015 FORECAST PROBLEM FOR TONIGHT WILL BE THUNDERSTORM DEVELOPMENT ALONG A FRONTAL BOUNDARY MAKING ITS WAY ACROSS CENTRAL IOWA. AT 20Z THE FRONTAL BOUNDARY WAS LOCATED ROUGHLY FROM OMAHA TO ATLANTIC THEN NORTHEAST TO FORT DODGE TO FOREST CITY. THE MAIN AREA OF CONCERN WILL BE THE I-80 CORRIDOR AND ESPECIALLY SOUTH WHERE IT HAS BEEN SUNNY ALL DAY AND HAS BEEN ABLE TO REALLY DESTABILIZE. MESOANALYSIS SHOWS AN UNCAPPED ENVIRONMENT WITH 5000-6000 CAPES ACROSS THE AREAS WEST OF I-35 AND SOUTH OF I-80. ONCE THE FRONT PUSHES TO THIS AREA THUNDERSTORMS SHOULD RAPIDLY DEVELOP AND BECOME SEVERE. AT THIS TIME IT LOOKS LIKE THE DES MOINES METRO AREA WILL BE ON THE WESTERN FRINGE OF THE DEVELOPMENT SO BETWEEN 21Z AND 00Z WE SHOULD SEE STORMS BLOW UP. STRONG LOW LEVEL SHEAR IN THE VICINITY OF THE FRONT WILL ALLOW FOR ROBUST UPDRAFTS AND THE POTENTIAL FOR A FEW TORNADOES. LARGE HAIL WILL ALSO BE A THREAT. THE STORMS WILL EVENTUALLY EVOLVE INTO A WIND THREAT AS WELL BUT THAT MAY BE EAST/SOUTH OF OUR AREA. THE STORMS SHOULD BE EAST OF THE AREA BY 06Z HOWEVER THE HRRR IS INDICATING A SECONDARY LINE DEVELOPING ALONG THE 850 FRONT AND PUSHING SOUTH BEFORE STALLING NEAR THE IA/MO BORDER. IF THIS HAPPENS SOUTHERN IOWA WILL BE GETTING SOME HEAVY RAINFALL AMOUNTS. AT THIS TIME CONFIDENCE IS LOW ON THAT SECOND SHOT OF RAINFALL SO I HAVE GRIDS CLEARING AFTER 06Z. .LONG TERM /SUNDAY THROUGH SATURDAY/... ISSUED AT 224 PM CDT SAT JUN 20 2015 SURFACE HIGH PRESSURE WILL BUILD ACROSS THE MIDWEST INTO THE OHIO VALLEY ON SUNDAY. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO BE SOUTH OF IOWA IN THE MORNING. A SHORTWAVE MOVING THROUGH THE WESTERLY FLOW ALOFT ACROSS THE NORTHERN PLAINS WILL STRENGTHEN A SURFACE LOW IN THE DAKOTAS SUNDAY AFTERNOON. THE PRESSURE GRADIENT IS EXPECTED TO TIGHTEN WITH SOUTHERLY SURFACE FLOW LIFTING A WARM FRONT NORTH. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP NEAR THE FRONT LATE IN THE DAY WITH CONVECTION BECOMING MORE WIDESPREAD DURING THE EVENING AND OVERNIGHT HOURS. INSTABILITY AND DEEP LAYER SHEAR WILL BE SUFFICIENT FOR A FEW STRONG TO SEVERE THUNDERSTORMS WITH DAMAGING WINDS AND HAIL THE PRIMARY HAZARDS. PRECIPITATION WILL END FROM SOUTHWEST TO NORTHEAST MONDAY. WARM FRONT LOOKS TO SETUP ACROSS NORTHERN KANSAS AND MISSOURI ON TUESDAY...GRADUALLY LIFTING NORTH AND PROVIDING A FOCUS FOR ADDITIONAL SHOWERS AND THUNDERSTORMS. THE LATE AFTERNOON THROUGH THE OVERNIGHT HOURS IS THE MOST LIKELY TIMEFRAME FOR PRECIPITATION. ANOTHER SHORTWAVE TROUGH MOVES THROUGH THE NORTHERN PLAINS INTO THE MIDWEST ON WEDNESDAY. OCCASIONAL SHOWERS AND THUNDERSTORMS COULD FESTER THROUGH THE DAY AIDED BY MULTIPLE SHORTWAVES MOVING THROUGH THE UPPER FLOW AND NEARBY FRONTAL BOUNDARY. PATTERN LOOKS TO REMAIN ACTIVE THROUGH THE END OF THE WEEK INTO NEXT WEEKEND WITH WEST AND NORTHWEST UPPER FLOW...MULTIPLE OUTFLOW BOUNDARIES AND A SURFACE FRONT SUPPORTING CHANCES FOR THUNDERSTORMS. && .AVIATION...20/18Z ISSUED AT 1257 PM CDT SAT JUN 20 2015 A COLD FRONT EXTENDS FROM ROUGHLY KEST SW TO KOFK AT 18Z AND WILL PUSH SE THROUGH 06Z..STALLING AROUND THE IA/MO BORDER. THUNDERSTORMS WILL INCREASE IN COVERAGE AND INTENSITY ALONG THIS BOUNDARY AFFECTING KALO THROUGH 23Z KDSM THROUGH 00Z AND KOTM THROUGH 06Z. MVFR COND CAN BE EXPECTED INVOF THE FRONTAL BOUNDARY DUE TO CIGS PRIMARILY BUT VSBYS WILL DROP AS WELL IN HEAVY RAINFALL. SFC FLOW WILL BECOME 35015KT IMMEDIATELY BEHIND THE FRONT THEN DIMINISH WITH LIGHTER WINDS EXPECTED AFT 02Z. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...FAB LONG TERM...ANGLE AVIATION...FAB
AREA FORECAST DISCUSSION
NWS DES MOINES IA
120 PM CDT SAT JUN 20 2015 .UPDATE... ISSUED AT 1257 PM CDT SAT JUN 20 2015 THE FORECAST REMAINS VERY DIFFICULT TODAY. MORNING THUNDERSTORMS HAVE LAID OUT NUMEROUS BOUNDARIES ACROSS CENTRAL IOWA. WE REMAIN VERY UNSTABLE ACROSS CENTRAL IOWA WITH THE BEST FORCING AT THE PRESENT TIME ACROSS EASTERN IOWA. THERE IS ALSO AN AREA OF BETTER THETA-E ADVECTION ACROSS EASTERN IOWA WHICH IS LIKELY WHY THE STRONGER STORMS ARE SUSTAINED ACROSS THAT AREA. THUNDERSTORMS ARE CONTINUING TO DEVELOP ACROSS NORTHERN IOWA AHEAD OF THE FRONTAL BOUNDARY IN AREAS WHERE MORNING CONVECTION HAS ALREADY OCCURRED. THE STORMS ARE MORE ELEVATED AND NOT TAPPING INTO THE BETTER LOW LEVEL SHEAR AND INSTABILITY AND THUS STORMS THERE ARE BENIGN. SOUTHERN/SOUTHEASTERN IOWA IS THE MAIN AREA OF CONCERN AT THIS POINT IN TIME. THIS AREA REMAINS IN A RELATIVELY CLOUD FREE AREA AND HAS BEEN HEATING UP AND DESTABILIZING ALL DAY. AS THE FRONT APPROACHES...STORMS WILL BECOME MORE SURFACE BASED AND SHOULD TAP THE BETTER LOW LEVEL SHEAR ASSOCIATED WITH THE FRONTAL BOUNDARY. THIS IS WHERE STRONG/SEVERE STORMS ARE EXPECTED TO EXPLODE LATER THIS AFTERNOON INTO THE EVENING. THE HRRR SEEMS TO DEVELOP ADDITIONAL STORMS ALONG THE 850MB BOUNDARY LATER THIS EVENING AND DROP IT SOUTH ALONG THE IA/MO BORDER FOR A SECOND ROUND OF STORMS AND ESPECIALLY HEAVY RAINFALL. NOT SURE IF I BUY THIS SCENARIO BUT SOUTHERN IA WILL BE UNDER THE GUN ANYWAY FOR PREVIOUSLY MENTIONED REASONS. SHOULD BE AN ACTIVE FEW HOURS THIS LATE AFTERNOON AND EVENING. && .SHORT TERM /TODAY/... ISSUED AT 347 AM CDT SAT JUN 20 2015 COMPLEX CONVECTIVE SCENARIO TODAY WITH MULTIPLE ROUNDS OF THUNDERSTORMS LIKELY. SYNOPTICALLY...WARM AND INCREASINGLY HUMID SOUTHERLY FLOW WILL COVER MUCH OF THE REGION TODAY BEFORE A COOL FRONT SURGES IN FROM THE NORTHWEST THIS AFTERNOON...PROGRESSING ACROSS THE FORECAST AREA THROUGH THIS EVENING. HOWEVER...THIS STRAIGHTFORWARD SCENARIO IS COMPLICATED BY A SEVERE MCS/BOW ECHO ROCKETING EASTWARD FROM SOUTH DAKOTA INTO SOUTHWEST MINNESOTA AND FAR NORTHWEST IOWA AT THIS HOUR. IT IS EXPECTED THAT THIS MCS WILL GRADUALLY DIMINISH IN INTENSITY AS IT MOVES EASTWARD ALONG THE IOWA/MINNESOTA BORDER...BUT STILL PRODUCE RAINFALL AND LEAVE BEHIND AN OUTFLOW BOUNDARY THAT SHOULD SAG SOUTHWARD BEFORE STALLING SOMEWHERE ACROSS NORTH CENTRAL IOWA. THIS BOUNDARY...AND DIFFERENTIAL HEATING CAUSED BY THE SOUTHERN EXTENSION OF THE ANVIL CLOUDS THROWN OFF BY THIS MCS...WILL CREATE MULTIPLE OPPORTUNITIES FOR FOCUS MECHANISMS ALONG WITH THE SYNOPTIC BOUNDARY MOVING IN LATER TODAY AS DAYTIME HEATING AND DESTABILIZATION OCCUR. IN OTHER WORDS...WHEN THUNDERSTORMS BREAK OUT AGAIN THIS AFTERNOON AND EVENING IT IS DIFFICULT TO PIN DOWN WHERE INITIATION WILL OCCUR AS IT WILL LIKELY BE DEPENDENT ON THE AFTER EFFECTS OF THE MORNING CONVECTION. AT ANY RATE...THIS INITIATION SHOULD OCCUR SOMEWHERE IN CENTRAL IOWA WITH STORMS THEN DEVELOPING GENERALLY TOWARD THE EAST AND SOUTHEAST AS THE SYNOPTIC BOUNDARY MOVES THROUGH THIS EVENING. THERE WILL BE A PRONOUNCED SEVERE WEATHER THREAT WITH THESE LATE DAY STORMS AS WELL OUTLINED IN CURRENT SPC PRODUCTS. THERE IS ALSO SOME QUESTION AS TO HOW MUCH PRECIPITATION WILL BE ABLE TO LINGER OR DEVELOP IN THE LATE MORNING AND MIDDAY HOURS...AFTER THE DEPARTURE OF THE EARLY MORNING MCS AND BEFORE AFTERNOON REDEVELOPMENT...AND HAVE MAINTAINED CHANCE POPS THROUGH THIS PERIOD BUT WITH LOW CONFIDENCE. OTHER THAN STORM/PRECIP TRENDS AND POTENTIAL FOR RESULTING SEVERE WEATHER...OTHER FORECAST FIELDS ARE BENIGN AND UNEVENTFUL TODAY. .LONG TERM /TONIGHT THROUGH FRIDAY/... ISSUED AT 347 AM CDT SAT JUN 20 2015 SUNDAY LOOKS TO BE MAINLY DRY ACROSS OUR CWA AS A SFC HIGH WILL BE CENTERED OVER OUR CWA DURING THE DAYTIME HOURS. MID TO UPPER LEVEL CLOUDS SHOULD BE PRESENT AS MODELS TRACKING AN IMPULSE WHICH CORRECTLY TRACES BACK TO THE PACIFIC COAST IN INITIALIZATION. SPEAKING OF INITIALIZATION...NAM NOT HANDLING SFC DWPTS VERY WELL FROM SOURCE REGION. NAM ABOUT 5 OR SO DEGREES TOO MOIST. SHOULDN/T HAVE MUCH OF AN IMPACT ON SENSIBLE WX AND DISCREPANCIES RESOLVE THEMSELVES BETTER FOR MONDAY/S SYSTEM. GFS AND NAM IN GOOD AGREEMENT WITH PICKING UP ON AN SFC LOW THAT IS EXPECTED TO PUSH THROUGH SOUTHERN MINNESOTA ON MONDAY. THERE WILL BE AN ATTENDANT BOUNDARY DRAPING FROM KALO THROUGH KDSM AT AROUND 00Z TUE. SVR WX MUST BE CONSIDERED NEAR THIS BOUNDARY DURING PEAK HEATING HOURS AS 0-6KM MUCAPE VALUES EASILY EXCEED 2000 J/KG. OVERALL SVR SETUP ON THE MARGINAL SIDE. PWATS OF 1.25 TO 1.5 AHEAD OF THIS BOUNDARY GOOD BUT NOT GREAT...AS IS 0-6KM BULK SHEAR OF 40 TO 45KTS WITH THE BOUNDARY. TODAY/S SVR WX ENV DEFINITELY MORE IMPRESSIVE. IN TRUE FASHION...NAM HAS CAP BEING EASILY BROKEN WHEREAS THE GFS HOLDS THE CAP. AS OF NOW...LOOKS LIKE ENOUGH FORCING/LIFT PRESENT TO PUNCH THROUGH CAP. MODELS COME INTO LINE WITH BRINGING HIGH PRESSURE ACROSS SOUTHERN MN ON TUESDAY...PLACING THE DMX CWA IN N/NE FLOW. THIS IS A BIT OF A SHIFT FROM MODEL OUTPUT A FEW DAYS AGO WHERE THE CWA WAS IN STRONG SOUTHERLY FLOW. CURRENT SOLUTION LOOKS GOOD SO HAVE DROPPED TEMPS A FEW DEGREES AND DROPPED POPS. FOR WEDNESDAY...THE AFOREMENTIONED SFC HIGH QUICKLY MOVES TOWARDS THE GREAT LAKES. MODELS HAVE BEEN CONSISTENT ON PICKING UP ON A THETA-E BOUNDARY SLOWLY PROPAGATING NORTHWARD INTO SOUTHERN IA. PWATS ARE A SOLID +1 TO +2 STD DEV WITH THIS FEATURE. FOR THE AFTERNOON...THE GFS HAS PWATS SOUTH OF I-80 IN THE 2 TO 2.25 INCH RANGE. UPWARD MOISTURE FLUX SETUP VERY IMPRESSIVE AS 0-6KM MUCAPE OVER 1000 J/KG AND 0-6KM MIXING RATIOS OVER 8 G/KG. VERY SATURATED PROFILE...ESPECIALLY EVIDENT ON KOTM FCST SOUNDING...COULD LEAD TO HEAVY RAIN. WITH PWATS SO HIGH...EXPECTING LITTLE TO NO SVR WX THREAT...BUT SIGNIFICANT RAIN POSSIBLE WED INTO THU AM. BEYOND THIS SYSTEM...MODELS BECOME VERY INCONSISTENT. TRENDS ARE COOLER AND DRIER...WITH HIGHS DROPPING BACK INTO THE MID 70S TO LOW 80S. && .AVIATION...20/18Z ISSUED AT 1257 PM CDT SAT JUN 20 2015 A COLD FRONT EXTENDS FROM ROUGHLY KEST SW TO KOFK AT 18Z AND WILL PUSH SE THROUGH 06Z..STALLING AROUND THE IA/MO BORDER. THUNDERSTORMS WILL INCREASE IN COVERAGE AND INTENSITY ALONG THIS BOUNDARY AFFECTING KALO THROUGH 23Z KDSM THROUGH 00Z AND KOTM THROUGH 06Z. MVFR COND CAN BE EXPECTED INVOF THE FRONTAL BOUNDARY DUE TO CIGS PRIMARILY BUT VSBYS WILL DROP AS WELL IN HEAVY RAINFALL. SFC FLOW WILL BECOME 35015KT IMMEDIATELY BEHIND THE FRONT THEN DIMINISH WITH LIGHTER WINDS EXPECTED AFT 02Z. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...FAB SHORT TERM...LEE LONG TERM...KOTENBERG AVIATION...FAB
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1030 PM CDT SAT JUN 20 2015 ...UPDATE TO SYNOPSIS... .SYNOPSIS... ISSUED AT 1030 PM CDT SAT JUN 20 2015 WV IMAGERY AND 00Z UPPER AIR ANALYSIS INDICATE A NORTHWESTERLY FLOW ALOFT PREVAILING ACROSS THE WESTERN HIGH PLAINS AS A WEAK UPPER LEVEL RIDGE OF HIGH PRESSURE TRANSITIONS EASTWARD ACROSS THE INTERMOUNTAIN WEST. NEAR THE SURFACE, A NEAR STATIONARY FRONTAL BOUNDARY EXTENDS FROM SOUTHWESTERN KANSAS NORTHEAST ACROSS CENTRAL KANSAS. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 313 PM CDT SAT JUN 20 2015 UPPER LEVEL WESTERLY FLOW CONTINUES TO BE SITUATED ACROSS THE NORTHERN CONUS TODAY WITH UPPER LEVEL HIGH PRESSURE CENTERED OVER THE DESERT SOUTHWEST. A WEAK MID LEVEL DISTURBANCE WAS MOVING EAST OVER NEBRASKA THIS AFTERNOON WHILE A STRONGER WAVE WAS MOVING OVER MONTANA. A COOL FRONT WAS SLOWLY PUSHING SOUTH FROM EASTERN COLORADO INTO NORTH CENTRAL KANSAS BY EARLY AFTERNOON. THE FRONT SHOULD MOVE SOUTH A LITTLE MORE EARLY THIS EVENING BEFORE BECOMING STATIONARY AND THEN SLOWLY LIFTING BACK TO THE NORTH LATER TONIGHT. THE RAP AND HRRR MODELS INDICATE SOME CONVECTION BREAKING OUT ALONG THE FRONT LATE THIS AFTERNOON. THESE ARE THE ONLY MODELS THAT DO SO AS THE HIRES ARW/NMM MODELS AS WELL AS THE OPERATIONAL NAM AND GFS KEEP THINGS DRY. THE MESOSCALE MODELS HAVE BEEN SHOWING A TENDENCY FOR CONVECTIVE TEMPERATURES TO BE REACHED IN CENTRAL KANSAS WHICH WOULD EXPLAIN THE CONVECTION. FOR NOW WILL KEEP THE FORECAST DRY IN CENTRAL KANSAS. TEMPERATURES TONIGHT WILL CONTINUE FAIRLY MILD IN THE MID 60S ALONG THE COLORADO BORDER TO THE LOWER 70S IN SOUTH CENTRAL KANSAS. SOUTHERLY WINDS WILL INCREASE AGAIN ON SUNDAY BUT SHOULD NOT HAVE QUITE THE DOWNSLOPE COMPONENT AS TODAY. IN SPITE OF THIS, WARMER AIR IN THE MID LEVELS WILL BE SPREADING OUT OF THE WEST AS THE UPPER LEVEL HIGH PRESSURE IN THE WEST MOVES TOWARD THE PLAINS. HIGHS WILL AGAIN BE VERY WARM...IN THE 95-100 DEGREE RANGE. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 248 PM CDT SAT JUN 20 2015 UPPER LEVEL RIDGING WILL PERSIST ACROSS THE SOUTHERN ROCKIES AND SOUTHERN PLAINS THROUGH MIDWEEK BEFORE SHIFTING WESTWARD INTO THE ROCKIES BY THURSDAY AND THEN AMPLIFYING OVER THE WESTERN UNITED STATES INTO THE WEEKEND. THIS WILL GENERALLY BE A HOT PATTERN, WITH LITTLE IN THE WAY OF PRECIPITATION. WEAK COLD FRONTS MAY GET CLOSE ENOUGH TO WESTERN KANSAS LATE TUESDAY THROUGH FRIDAY, PARTICULARLY NEAR INTERSTATE 70 SO THAT A FEW THUNDERSTORMS ARE POSSIBLE. BUT THESE STORMS OUGHT TO BE ISOLATED TO SCATTERED; AND GIVEN THE WEAK WINDS AT UPPER LEVELS, WILL PROBABLY NOT BE SEVERE OTHER THAN AN ISOLATED DAMAGING WIND GUST. IF THE UPPER LEVEL RIDGE RETROGRADES BACK OVER UTAH BY FRIDAY AND SATURDAY AS THE MODELS SUGGEST, THEN HIGH TEMPERATURES COULD DROP BACK INTO THE UPPER 80S TO LOWER 90S STARTING FRIDAY, ALONG WITH A FEW THUNDERSTORMS AS THE COLD FRONT PASSES. BUT UNTIL THEN, EXPECT HIGHS TO BE IN THE 90S TO POSSIBLY NEAR 100F, WITH LOWS IN THE UPPER 60S TO LOWER 70S. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 558 PM CDT SAT JUN 20 2015 A FRONTAL BOUNDARY WILL STALL OUT NEAR KHYS AND KGCK, THEN MOVE BACK NORTH TOWARDS DAWN. EXPECT VFR CONDITIONS. THERE COULD BE SOME LOWER STRATUS AND FOG NEAR KHYS AFTER 09Z. THERE IS ALSO A SMALL CHANCE FOR A FEW THUNDERSTORMS NEAR THE FRONTAL BOUNDARY IN THE KHYS AREA THIS EVENING, BUT TOO LOW OF CONFIDENCE TO PUT INTO THE TAF. && .PRELIMINARY POINT TEMPS/POPS... DDC 68 98 71 96 / 0 0 0 0 GCK 68 100 70 101 / 0 0 0 0 EHA 67 99 69 100 / 0 0 0 0 LBL 69 98 69 97 / 0 0 0 0 HYS 69 99 73 101 / 0 0 0 10 P28 72 96 73 96 / 0 0 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...JJOHNSON SHORT TERM...GERARD LONG TERM...FINCH AVIATION...KRUSE
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
603 PM CDT SAT JUN 20 2015 ...UPDATED FOR AVIATION... .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 313 PM CDT SAT JUN 20 2015 UPPER LEVEL WESTERLY FLOW CONTINUES TO BE SITUATED ACROSS THE NORTHERN CONUS TODAY WITH UPPER LEVEL HIGH PRESSURE CENTERED OVER THE DESERT SOUTHWEST. A WEAK MID LEVEL DISTURBANCE WAS MOVING EAST OVER NEBRASKA THIS AFTERNOON WHILE A STRONGER WAVE WAS MOVING OVER MONTANA. A COOL FRONT WAS SLOWLY PUSHING SOUTH FROM EASTERN COLORADO INTO NORTH CENTRAL KANSAS BY EARLY AFTERNOON. THE FRONT SHOULD MOVE SOUTH A LITTLE MORE EARLY THIS EVENING BEFORE BECOMING STATIONARY AND THEN SLOWLY LIFTING BACK TO THE NORTH LATER TONIGHT. THE RAP AND HRRR MODELS INDICATE SOME CONVECTION BREAKING OUT ALONG THE FRONT LATE THIS AFTERNOON. THESE ARE THE ONLY MODELS THAT DO SO AS THE HIRES ARW/NMM MODELS AS WELL AS THE OPERATIONAL NAM AND GFS KEEP THINGS DRY. THE MESOSCALE MODELS HAVE BEEN SHOWING A TENDENCY FOR CONVECTIVE TEMPERATURES TO BE REACHED IN CENTRAL KANSAS WHICH WOULD EXPLAIN THE CONVECTION. FOR NOW WILL KEEP THE FORECAST DRY IN CENTRAL KANSAS. TEMPERATURES TONIGHT WILL CONTINUE FAIRLY MILD IN THE MID 60S ALONG THE COLORADO BORDER TO THE LOWER 70S IN SOUTH CENTRAL KANSAS. SOUTHERLY WINDS WILL INCREASE AGAIN ON SUNDAY BUT SHOULD NOT HAVE QUITE THE DOWNSLOPE COMPONENT AS TODAY. IN SPITE OF THIS, WARMER AIR IN THE MID LEVELS WILL BE SPREADING OUT OF THE WEST AS THE UPPER LEVEL HIGH PRESSURE IN THE WEST MOVES TOWARD THE PLAINS. HIGHS WILL AGAIN BE VERY WARM...IN THE 95-100 DEGREE RANGE. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 248 PM CDT SAT JUN 20 2015 UPPER LEVEL RIDGING WILL PERSIST ACROSS THE SOUTHERN ROCKIES AND SOUTHERN PLAINS THROUGH MIDWEEK BEFORE SHIFTING WESTWARD INTO THE ROCKIES BY THURSDAY AND THEN AMPLIFYING OVER THE WESTERN UNITED STATES INTO THE WEEKEND. THIS WILL GENERALLY BE A HOT PATTERN, WITH LITTLE IN THE WAY OF PRECIPITATION. WEAK COLD FRONTS MAY GET CLOSE ENOUGH TO WESTERN KANSAS LATE TUESDAY THROUGH FRIDAY, PARTICULARLY NEAR INTERSTATE 70 SO THAT A FEW THUNDERSTORMS ARE POSSIBLE. BUT THESE STORMS OUGHT TO BE ISOLATED TO SCATTERED; AND GIVEN THE WEAK WINDS AT UPPER LEVELS, WILL PROBABLY NOT BE SEVERE OTHER THAN AN ISOLATED DAMAGING WIND GUST. IF THE UPPER LEVEL RIDGE RETROGRADES BACK OVER UTAH BY FRIDAY AND SATURDAY AS THE MODELS SUGGEST, THEN HIGH TEMPERATURES COULD DROP BACK INTO THE UPPER 80S TO LOWER 90S STARTING FRIDAY, ALONG WITH A FEW THUNDERSTORMS AS THE COLD FRONT PASSES. BUT UNTIL THEN, EXPECT HIGHS TO BE IN THE 90S TO POSSIBLY NEAR 100F, WITH LOWS IN THE UPPER 60S TO LOWER 70S. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 558 PM CDT SAT JUN 20 2015 A FRONTAL BOUNDARY WILL STALL OUT NEAR KHYS AND KGCK, THEN MOVE BACK NORTH TOWARDS DAWN. EXPECT VFR CONDITIONS. THERE COULD BE SOME LOWER STRATUS AND FOG NEAR KHYS AFTER 09Z. THERE IS ALSO A SMALL CHANCE FOR A FEW THUNDERSTORMS NEAR THE FRONTAL BOUNDARY IN THE KHYS AREA THIS EVENING, BUT TOO LOW OF CONFIDENCE TO PUT INTO THE TAF. && .PRELIMINARY POINT TEMPS/POPS... DDC 68 98 71 96 / 0 0 0 0 GCK 68 100 70 101 / 0 0 0 0 EHA 67 99 69 100 / 0 0 0 0 LBL 69 98 69 97 / 0 0 0 0 HYS 69 99 73 101 / 10 10 10 10 P28 72 96 73 96 / 0 0 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...GERARD LONG TERM...FINCH AVIATION...KRUSE
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
314 PM CDT SAT JUN 20 2015 ...UPDATED SHORT TERM DISCUSSION... .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 313 PM CDT SAT JUN 20 2015 UPPER LEVEL WESTERLY FLOW CONTINUES TO BE SITUATED ACROSS THE NORTHERN CONUS TODAY WITH UPPER LEVEL HIGH PRESSURE CENTERED OVER THE DESERT SOUTHWEST. A WEAK MID LEVEL DISTURBANCE WAS MOVING EAST OVER NEBRASKA THIS AFTERNOON WHILE A STRONGER WAVE WAS MOVING OVER MONTANA. A COOL FRONT WAS SLOWLY PUSHING SOUTH FROM EASTERN COLORADO INTO NORTH CENTRAL KANSAS BY EARLY AFTERNOON. THE FRONT SHOULD MOVE SOUTH A LITTLE MORE EARLY THIS EVENING BEFORE BECOMING STATIONARY AND THEN SLOWLY LIFTING BACK TO THE NORTH LATER TONIGHT. THE RAP AND HRRR MODELS INDICATE SOME CONVECTION BREAKING OUT ALONG THE FRONT LATE THIS AFTERNOON. THESE ARE THE ONLY MODELS THAT DO SO AS THE HIRES ARW/NMM MODELS AS WELL AS THE OPERATIONAL NAM AND GFS KEEP THINGS DRY. THE MESOSCALE MODELS HAVE BEEN SHOWING A TENDENCY FOR CONVECTIVE TEMPERATURES TO BE REACHED IN CENTRAL KANSAS WHICH WOULD EXPLAIN THE CONVECTION. FOR NOW WILL KEEP THE FORECAST DRY IN CENTRAL KANSAS. TEMPERATURES TONIGHT WILL CONTINUE FAIRLY MILD IN THE MID 60S ALONG THE COLORADO BORDER TO THE LOWER 70S IN SOUTH CENTRAL KANSAS. SOUTHERLY WINDS WILL INCREASE AGAIN ON SUNDAY BUT SHOULD NOT HAVE QUITE THE DOWNSLOPE COMPONENT AS TODAY. IN SPITE OF THIS, WARMER AIR IN THE MID LEVELS WILL BE SPREADING OUT OF THE WEST AS THE UPPER LEVEL HIGH PRESSURE IN THE WEST MOVES TOWARD THE PLAINS. HIGHS WILL AGAIN BE VERY WARM...IN THE 95-100 DEGREE RANGE. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 248 PM CDT SAT JUN 20 2015 UPPER LEVEL RIDGING WILL PERSIST ACROSS THE SOUTHERN ROCKIES AND SOUTHERN PLAINS THROUGH MIDWEEK BEFORE SHIFTING WESTWARD INTO THE ROCKIES BY THURSDAY AND THEN AMPLIFYING OVER THE WESTERN UNITED STATES INTO THE WEEKEND. THIS WILL GENERALLY BE A HOT PATTERN, WITH LITTLE IN THE WAY OF PRECIPITATION. WEAK COLD FRONTS MAY GET CLOSE ENOUGH TO WESTERN KANSAS LATE TUESDAY THROUGH FRIDAY, PARTICULARLY NEAR INTERSTATE 70 SO THAT A FEW THUNDERSTORMS ARE POSSIBLE. BUT THESE STORMS OUGHT TO BE ISOLATED TO SCATTERED; AND GIVEN THE WEAK WINDS AT UPPER LEVELS, WILL PROBABLY NOT BE SEVERE OTHER THAN AN ISOLATED DAMAGING WIND GUST. IF THE UPPER LEVEL RIDGE RETROGRADES BACK OVER UTAH BY FRIDAY AND SATURDAY AS THE MODELS SUGGEST, THEN HIGH TEMPERATURES COULD DROP BACK INTO THE UPPER 80S TO LOWER 90S STARTING FRIDAY, ALONG WITH A FEW THUNDERSTORMS AS THE COLD FRONT PASSES. BUT UNTIL THEN, EXPECT HIGHS TO BE IN THE 90S TO POSSIBLY NEAR 100F, WITH LOWS IN THE UPPER 60S TO LOWER 70S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1218 PM CDT SAT JUN 20 2015 GUSTY SOUTHWEST WINDS WILL CONTINUE AT THE TERMINALS THIS AFTERNOON BUT THE WINDS AT GARDEN CITY SHOULD DIMINISH THROUGH EARLY AFTERNOON AS A WEAK COLD FRONT PUSHES INTO THE AREA. WINDS AT GARDEN CITY AND HAYS ARE EXPECTED TO BECOME NORTHERLY BY LATE AFTERNOON OR EARLY EVENING AS THE FRONT MOVES IN. WINDS WILL BE LIGHT AND VARIABLE OVERNIGHT AS THE FRONT STALLS AND THEN BEGINS LIFTING BACK NORTHWARD. THERE IS A SMALL CHANCE FOR THUNDERSTORMS TO DEVELOP AROUND HAYS AROUND 21-23Z BUT CONFIDENCE IN THIS IS TOO LOW TO INCLUDE IN THE TAF AT THIS TIME. && .PRELIMINARY POINT TEMPS/POPS... DDC 68 98 71 96 / 0 0 0 0 GCK 68 100 70 101 / 0 0 0 0 EHA 67 99 69 100 / 0 0 0 0 LBL 69 98 69 97 / 0 0 0 0 HYS 69 99 73 101 / 10 10 10 10 P28 72 96 73 96 / 0 0 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...GERARD LONG TERM...FINCH AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1145 PM CDT THU JUN 18 2015 .DISCUSSION... 19/06Z TAF ISSUANCE. && .AVIATION... MUCH QUIETER CONDITIONS ACRS THE AREA COMPARED TO LAST NIGHT. LITTLE ACTIVITY NOTED ON RADAR WITH THE EXCEPTION OF A FEW SHRA WELL SW OF THE AREA AND OVER THE COASTAL WATERS. LATEST STLT SHOWS MOSTLY HIGH CLOUDS STREAMING NE OVER THE AREA...ALONG WITH A FEW STRATOCU IN THE LOWER LVLS. VFR TO PREVAIL THROUGH THE PERIOD ALTHOUGH SOME LOW MVFR CIGS MAY DEVELOP BRIEFLY NEAR DAYBREAK. LOW CIGS WILL LIFT/DISSIPATE BY MID-MORNING WITH SWLY WINDS AROUND 10 KT OR LESS DURING THE DAY. WITH THE AREA REMAINING UNDER A WEAKNESS ALOFT AS THE REMNANTS OF BILL PASS NORTH OF THE REGION AND DECENT MOISTURE STILL STREAMING FM SRN/SE TX INTO NRN LA...WENT AHEAD AND INSERTED VCSH FOR BPT AND AEX DURING THE DAY TOMORROW WITH ANY ACTIVITY ELSEWHERE EXPECTED TO REMAIN TOO ISLTD FOR MENTION AT THIS TIME. 24 && .PREV DISCUSSION... /ISSUED 919 PM CDT THU JUN 18 2015/ UPDATE...DUE TO AREAL FLOODING AND POTENTIAL FOR SOME SHOWER AND THUNDERSTORM ACTIVITY LATE TONIGHT...HAVE OPTED TO KEEP THE FLASH FLOOD WATCH GOING THROUGH TONIGHT. WHILE RAIN HAS DISSIPATED IN THE EARLY EVENING...LATEST HRRR HINTS AT SOME DEVELOPMENT ACROSS SE TEXAS LATE TONIGHT AND EVEN MODEST AMOUNTS COULD POSE SOME PROBLEMS TONIGHT OVER WATCH AREA. NO OTHER CHANGES AT THIS MOMENT. AP PREV DISCUSSION... /ISSUED 339 PM CDT THU JUN 18 2015/ DISCUSSION...SCATTERED SHOWERS AND A FEW THUNDERSTORMS SHOWN BY RADAR MOSAIC FROM SOUTH TEXAS TO THE WESTERN EDGE OF THE LOCAL FORECAST AREA...AND THEN EXTENDING FURTHER NORTHEAST. ACTIVITY FOCUSED WITHIN MOISTURE PLUME LEFT FROM TROPICAL DEPRESSION BILL NOW OVER EAST CENTRAL OKLAHOMA AND ON A NORTHEAST TRACK. FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 7 PM CDT FOR SOUTHEAST TEXAS AND WEST CENTRAL LOUISIANA. CONVECTION HAS SLIPPED A LITTLE FURTHER EAST THROUGH THE AFTERNOON HOURS AND IS NOW KNOCKING ON THE DOORS OF HARDIN AND TYLER COUNTIES. WILL CONTINUE TO CLOSELY MONITOR CONVECTION...AND HOPEFULLY IT WILL TREND TOWARD MODEL GUIDANCE LIMITING ANY ADDITIONAL SIGNIFICANT RAINFALL ACROSS THIS AREA. NONE-THE-LESS...MODELS HAVE BEEN LESS THAN SCHOLAR REGARDING THE EASTERN EXTENT OF MASS FIELDS ASSOCIATED WITH BILL. HAVE MAINTAINED RESPECTABLE POPS ACROSS SOUTHEAST TEXAS/WEST CENTRAL LOUISIANA FOR THE OVERNIGHT HOURS. BILL WILL CONTINUE TO ADVANCE NORTHEAST. AREA WILL HOWEVER REMAIN UNDER A WEAKNESS ALOFT BETWEEN THE SUBTROPICAL HIGH AND SOUTHWEST CONUS ANTICYCLONE. WITH A MOIST SOUTHERLY LOW LEVEL FLOW REMAINING IN PLACE AND NO CAPPING...SHOULD SEE SOME ISOLATED TO SCATTERED SHOWER AND THUNDERSTORM DEVELOPMENT BOTH FRIDAY AND SATURDAY...MAINLY DURING THE AFTERNOON AND EARLY EVENING. THE NEW WEEK WILL SEE AN EASTWARD EXPANSION OF SOUTHWEST CONUS RIDGE INTO THE AREA. THIS WILL SET UP THE LIKELIHOOD OF LITTLE IF ANY RAINS...AS WELL AS TEMPERATURES TICKING UPWARD. MARINE...A LIGHT AND OCCASIONAL MODERATE ONSHORE FLOW CAN BE EXPECTED AS THE SUBTROPICAL HIGH BECOMES REESTABLISHED OVER THE REGION. RAIN CHANCES WILL REMAIN MINIMAL. 23 && .PRELIMINARY POINT TEMPS/POPS... AEX 75 90 74 92 / 20 30 10 20 LCH 76 89 76 89 / 20 20 10 20 LFT 76 89 75 90 / 20 20 10 20 BPT 76 89 75 90 / 30 30 10 20 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...FLASH FLOOD WATCH UNTIL 7 AM CDT FRIDAY FOR LAZ027-030. TX...FLASH FLOOD WATCH UNTIL 7 AM CDT FRIDAY FOR TXZ180-201-215-216- 259>262. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
249 PM EDT FRI JUN 19 2015 .SYNOPSIS... THE REMNANTS OF TROPICAL SYSTEM BILL WILL BRING SHOWERS SATURDAY...FOLLOWED BY A STRONG SUNDAY COLD FRONT. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... A SURFACE BOUNDARY FROM SW PA INTO CENTRAL OH IS PROGGED TO DRIFT SLOWLY SOUTH THIS EVENING. MOISTURE POOLING NEAR THE BOUNDARY AND A CROSSING SHORTWAVE WILL CONTINUE TO BRING SHOWER CHANCES TO THE REGION SOUTH OF I 80. USED A BLEND OF THE GFS/ECMWF AND HRRR WITH THE NAM TRACKING UNREALISTIC SURFACE LOWS ACROSS THE AREA. LOWS SHOULD BE SEVERAL DEGREES ABOVE SEASONAL LEVELS. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/... THE REMNANTS OF TROPICAL STORM BILL ARE PROGGED TO APPROACH AND CROSS THE REGION SATURDAY AND SATURDAY EVENING. MODELS KEEP THE HEAVIEST QPF ACROSS WV AND KY AND THIS SEEMS REASONABLE. LOCALLY HEAVY RAIN IS STILL EXPECTED ESPECIALLY SOUTH OF PIT...BUT WITH A PROGGED INCREASE IN THE SPEED OF THE SYSTEM NO FLOOD WATCH IS PLANNED. WILL MENTION LOCALIZED FLOODING IN THE HWO WHERE ANY TRAINING OF HEAVIER RAIN OCCURS. INSTABILITY IS PROGGED TO REMAIN LIMITED SO ONLY INCLUDED A CHANCE OF THUNDER. THIS SHOULD QUICKLY EXIT SATURDAY EVENING. RIDGING BRIEFLY BUILDS IN SATURDAY NIGHT BEFORE A STRONG COLD FRONT APPROACHES AND CROSSES THE REGION SUNDAY. SHEAR AND INSTABILITY ARE SUFFICIENT FOR POTENTIAL SEVERE STORMS. WILL MONITOR TRENDS AND INCLUDE IN THE HWO FOR NOW. RIDGING IS PROGGED FOR LATER SUNDAY NIGHT INTO MONDAY BEFORE THE APPROACH OF THE NEXT SHORTWAVE LATER MONDAY. GENERALLY FOLLOWED GFS/ECMWF SOLUTIONS...WITH SEASONALLY WARM TEMPERATURES THROUGH THE PERIOD. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... A BREAK IN THE ACTIVE WEATHER PATTERN WILL ARRIVE BY MIDWEEK AS HIGH PRESSURE BUILDS INTO THE UPPER OHIO VALLEY. THIS REPRIEVE WILL BE SHORT LIVED...AS ANOTHER WARM FRONT WILL BRING THE RISK FOR SHOWERS AND STORMS ON THURSDAY. && .AVIATION /19Z FRIDAY THROUGH WEDNESDAY/... RAIN AND RESTRICTION POTENTIAL WILL CONTINUE INTO SATURDAY AS A CROSSING DISTURBANCE INTERACTS WITH THE FRONTAL BOUNDARY SAGGING OVER THE REGION...THEN AS THE REMNANT TROPICAL LOW APPROACHES AND SHUNTS ADDITIONAL MOISTURE INTO THE FRONTAL ZONE. THE BETTER CHANCE OF PROLONGED DEGRADATION WILL THUS BE OVER PORTS FROM PIT SOUTHWARD. .OUTLOOK.../SATURDAY THROUGH TUESDAY/... FURTHER RESTRICTIONS ARE LIKELY ON SUNDAY WITH PASSAGE OF COLD FRONT. && .HYDROLOGY... THE MOISTURE ASSOCIATED WITH REMNANTS OF TROPICAL STORM BILL WILL BRING A PERIOD OF HEAVY RAIN SATURDAY AFTERNOON AND SATURDAY NIGHT TO PARTS OF THE AREA. THE HEAVIEST RAINS ARE EXPECTED OVER KENTUCKY/WEST VIRGINIA AND NOT OVER OHIO/PENNSYLVANIA. FORECAST CHANGE: THE RAIN SYSTEM IS EXPECTED TO MOVE SLIGHTLY FASTER WITH A DOWNWARD ADJUSTMENT IN THE PROJECTED RAINFALL AMOUNTS THAN PREVIOUSLY FORECAST. IT IS ESTIMATED THAT THE MONONGAHELA AND CHEAT BASINS WILL RECEIVE BETWEEN 1.50 AND 2.00 INCHES. BETWEEN 0.50 AND 0.75 IS EXPECTED IN THE IMMEDIATE PITTSBURGH AREA WITH LESS THAN 0.50 INCH OVER THE ALLEGHENY BASIN. UNCERTAINTY REMAINS. A SHIFT TO THE NORTH COULD MEAN HIGHER AMOUNTS OF OHIO AND PENNSYLVANIA. HEIGHTENED AWARENESS IS NEEDED THIS WEEKEND AND EARLY NEXT WEEK ON AREA RIVERS. CURRENTLY NO RIVER FLOODING IS EXPECTED, BUT STREAMS AND CREEKS COULD EXPERIENCE FLOODING WHERE THE HEAVY RAINS FALL. CRESTS ARE EXPECTED ON THE CHEAT RIVER SUNDAY AFTERNOON, AND CRESTS ON THE MONONGAHELA AND OHIO WILL COME ON MONDAY. PARSONS IS EXPECTED TO CREST AROUND 8 FEET. GRAYS LANDING IS PROJECTED TO CREST JUST BELOW 15 FEET. PITTSBURGH WILL REMAIN IN POOL THROUGH THE ENTIRE PERIOD. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ 07/15
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
712 PM EDT SAT JUN 20 2015 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 420 PM EDT SAT JUN 20 2015 WV IMAGERY AND RAP ANALYSIS INDICATED A ZONAL PATTERN ACROSS THE NRN CONUS. THE SHORTWAVE TROUGH THAT BROUGHT THE LARGE AREA OF RAIN THROUGH UPPER MI WAS EXITING THE AREA LEAVING MAINLY JUST PATCHY LIGHT RAIN OF DRIZZLE OVER THE NORTH AND EAST. ANOTHER TRAILING SHRTWV OVER NE MN SUPPORTED SCT SHRA FROM THE MN ARROWHEAD INTO WRN LAKE SUPERIOR. OTHER UPSTREAM SHORTWAVES WERE LOCATED OVER NRN ND AND SE SASK. TONIGHT...EXPECT ISOLD/SCT -SHRA INTO THE CWA THIS EVENING ASSOCIATED WITH THE MN SHRTWV THAT SHOULD DIMINISH AND END AFTER 03Z. OTHERWISE...WITH ABUNDANT LOW LEVEL MOISTURE OVER THE REGION...PATCHY FOG WILL SHOULD DEVELOP. NNW UPSLOPE 10-15 KNOT 950- 900 MB FLOW INTO N CNTRL UPPER MI MAY ALSO SUPPORT SOME DRIZZLE OVERNIGHT INTO EARLY SUNDAY. SUN...THERE MAY BE SOME ISOLATED LIGHT SHOWERS ASSOCIATED WITH THE SASK/ND SHRTWVS EARLY OVER THE NORTH. OTHERWISE...EXPECT A WEAK SFC RIDGE TO BUILD INTO THE AREA WITH MAINLY LIGHT WINDS ALLOWING LAKE BREEZES TO DEVELOP. MODEL CONSENSUS SHOWS MLCAPE VALUES COULD CLIMB INTO THE 500-1000 J/KG RANGE OVER MAINLY THE SRN CWA FROM NEAR IMT- MNM. THIS MAY BE ENOUGH TO ALLOW SOME SHRA/TSRA TO DEVELOP...ESPECIALLY NEAR THE LAKE MI BREEZE BOUNDARY. WITH LIMITED INSTABILITY FARTHER NORTH AND SOME MID LEVEL CAPPING NEAR 700 MB...NO AFTERNOON PCPN IS EXPECTED OVER THE REST OF THE CWA. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 310 PM EDT SAT JUN 20 2015 UPPER GREAT LAKES REGION WILL STILL BE UNDER THE INFLUENCE OF A HIGH PRESSURE RIDGE AT THE START OF THE LONG TERM PERIOD...BUT ITS INFLUENCE WILL BE SHORT LIVED AS A POTENT SHORTWAVE AND ASSOCIATED LOW PRESSURE SYSTEM WILL SWEEP ACROSS THE AREA ON MONDAY. THE SHORTWAVE THAT WILL AFFECT THE AREA ON MONDAY IS ACTUALLY TWO SEPARATE WAVES AT THIS TIME...ONE OVER BRITISH COLUMBIA AND THE OTHER OVER THE PACIFIC TO THE WEST OF OREGON. THESE TWO WAVES WILL MERGE OVER THE NORTHERN ROCKIES TOMORROW AND THEN QUICKLY SHIFT EAST INTO THE AREA FOR MONDAY. A LOW AVERAGING 1000MB WILL SLIDE NORTHEAST...TRACKING FROM EASTERN WYOMING ON SUNDAY AFTERNOON...TO MINNESOTA ON MONDAY AFTERNOON AND THEN ACROSS THE UPPER GREAT LAKES ON MONDAY NIGHT. MUCH OF THE FORECAST DEPENDS BOTH ON THE TRACK OF THE SHORTWAVE AND THE DEVELOPMENT OF CONVECTION ALONG THE WARM FRONT AHEAD OF THE LOW. LATEST MODEL RUNS SHOW THE SHORTWAVE TRACKING ACROSS SOUTHERN UPPER MICHIGAN OR NORTHERN WISCONSIN...WITH THE WARM FRONT LIKELY LOCATED IN NORTHERN/CENTRAL WISCONSIN. THAT IS CLOSE ENOUGH TO CONTINUE TO SHOW LIKELY TO DEFINITE POPS SPREADING EAST INTO THE AREA ON MONDAY MORNING AND CONTINUING INTO EARLY MONDAY EVENING AS THE MAIN FORCING MOVES THROUGH THE UPPER GREAT LAKES. THE POSITION OF THE WARM FRONT WILL DETERMINE SEVERE WEATHER POTENTIAL...AS THAT WILL BE THE AREA WHERE THE NOSE OF THE 35-40KT 850MB JET AND INSTABILITY GRADIENT WILL BE LOCATED. WHILE SOME MODELS DO TRY TO SHIFT IT NORTH INTO OUR AREA...BELIEVE THAT CONVECTION AND POSSIBLE MCS THAT DEVELOPS UPSTREAM IN MINNESOTA ON SUNDAY NIGHT WILL SUPPRESS THE BOUNDARY FARTHER TO THE SOUTH. ASSUMING THAT OCCURS...THE BETTER INSTABILITY WILL BE WELL TO THE SOUTH OF THE AREA AND THE GRADIENT SOMEWHERE IN CENTRAL/NORTHERN WISCONSIN. THINK THE LATEST DAY 3 OUTLOOK FROM SPC HAS A GOOD HANDLE ON WHERE THE STRONGEST STORMS WILL BE AND GENERALLY TO THE SOUTH OF THE U.P.. WILL CONTINUE TO MENTION SLIGHT/CHANCE THUNDERSTORMS OVER THE SOUTHERN HALF TO TWO-THIRDS OF THE CWA WHICH IS CLOSE ENOUGH TO POTENTIAL EXPERIENCE SOME RUMBLES OF THUNDER. WITH THE DYNAMICS OF THE SYSTEM...IF THE INSTABILITY OR WARM FRONT SHIFTS FARTHER TO THE NORTH...SEVERE STORMS WOULD BE POSSIBLE. AS THE LOW DEPARTS ON MONDAY NIGHT...EXPECT A WEST TO EAST DIMINISHMENT OF POPS AND CLOUD COVER ACROSS THE AREA. HAVE TRENDED WINDS UP BASED OFF ALL OF THE LATEST RUNS...WITH 925MB WINDS AROUND 35KTS. THAT WIND WILL LIMIT THE POTENTIAL FOR FOG ON MONDAY NIGHT ACROSS THE U.P.. THINK THE MAIN AREAS THAT WILL SEE FOG WILL BE ALONG THE LAKE MICHIGAN SHORELINE ON MONDAY EVENING AND SHORELINES ALONG CENTRAL/EASTERN LAKE SUPERIOR AS THE WINDS TURN TO THE NORTHWEST AND PUSH THE FOG ONSHORE. WINDS WILL BE DECREASING ON TUESDAY. THE AREA WILL BE UNDER WEST-NORTHWEST FLOW ALOFT FOR TUESDAY AND WEDNESDAY...AS A HIGH PRESSURE RIDGE MOVES OVER THE AREA FOR TUESDAY AND THEN DEPARTS ON WEDNESDAY AS THE PARENT HIGH MOVES INTO THE OHIO RIVER VALLEY. WHILE THE RIDGE IS OVER THE AREA...EXPECT DRY CONDITIONS AND TEMPERATURES TO BE NEAR NORMAL. THE NEXT SHORTWAVE WILL MOVE THROUGH THE AREA SOMETIME BETWEEN LATE WEDNESDAY AFTERNOON AND THURSDAY...THROUGH THE WEST-NORTHWEST FLOW ALOFT. WITH THE SOURCE REGION...AND THE WARM FRONT SITUATED OVER THE CENTRAL PLAINS...EXPECT MOISTURE TO BE LIMITED AND WILL ONLY INCLUDE SLIGHT/CHANCE POPS FOR THE PASSAGE OF THE WAVE. INSTABILITY IS ALSO LIMITED AND WILL KEEP VALUES CAPPED AT SLIGHT CHANCES...BUT WILL NEED TO WATCH DIURNAL HEATING ON THURSDAY...WHICH COULD INCREASE POTENTIAL SOME. A WEAK HIGH WILL MOVE OVER THE AREA ON THURSDAY NIGHT AND THE FIRST PART OF FRIDAY BEFORE ANOTHER SHORTWAVE DROPS SOUTHEAST INTO THE AREA FOR LATER FRIDAY INTO SATURDAY. WHILE THERE IS THE POTENTIAL FOR RAIN DURING THIS PERIOD...THE MORE NOTABLE ITEM IS THE AMPLIFICATION OF AN UPPER TROUGH OVER THE GREAT LAKES REGION FOR NEXT WEEKEND AND LIKELY CONTINUING INTO NEXT WEEK. BOTH THE ECMWF/GFS ENSEMBLES SUPPORT THAT IDEA...AND EVEN SHOW HINTS OF THAT TROUGH REMAINING IN PLACE TOWARDS THE FOURTH OF JULY. IF THAT SETUP OCCURS...THE U.P. WOULD EXPERIENCE A COOL AND DRY PERIOD OF WEATHER FOR THE END OF JUNE AND START OF JULY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 712 PM EDT SAT JUN 20 2015 LOW LEVEL MOISTURE WILL REMAIN INTO SUNDAY AFTERNOON BEFORE DRIER AIR ARRIVES. UNTIL THEN...LIFR/VLIFR CONDITIONS WILL BE EXPECTED AT ALL THE TAF SITES INTO SUN MORNING BEFORE A SLOW IMPROVEMENT TO VFR TAKES PLACE SUN AFTERNOON. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 420 PM EDT SAT JUN 20 2015 TYPICAL SUMMERTIME CONDITIONS WITH GENERALLY LIGHT WINDS WILL DOMINATE ACROSS LAKE SUPERIOR THROUGH THE FCST PERIOD. WITH WEAK HIGH PRES BUILDING INTO THE AREA BEHIND THE DISTURBANCE MOVING OUT OF THE AREA TONIGHT...LIGHTER WINDS WILL FOLLOW FOR THE LAST HALF THE WEEKEND. THESE LIGHT WINDS...UNDER 20KT...WILL LIKELY CONTINUE THRU THE FIRST HALF OF NEXT WEEK AS A WEAK SUMMERTIME PRES GRADIENT SHOULD PREVAIL. THE RAIN TODAY WILL SUPPORT FOG ACROSS THE LAKE...THAT COULD BE LOCALLY DENSE. EXPECT THE FOG TO LINGER INTO EARLY NEXT WEEK DUE TO A LACK OF STRONG ADVECTION OF DRIER AIR. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...SRF AVIATION...07 MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
420 PM EDT SAT JUN 20 2015 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 420 PM EDT SAT JUN 20 2015 WV IMAGERY AND RAP ANALYSIS INDICATED A ZONAL PATTERN ACROSS THE NRN CONUS. THE SHORTWAVE TROUGH THAT BROUGHT THE LARGE AREA OF RAIN THROUGH UPPER MI WAS EXITING THE AREA LEAVING MAINLY JUST PATCHY LIGHT RAIN OF DRIZZLE OVER THE NORTH AND EAST. ANOTHER TRAILING SHRTWV OVER NE MN SUPPORTED SCT SHRA FROM THE MN ARROWHEAD INTO WRN LAKE SUPERIOR. OTHER UPSTREAM SHORTWAVES WERE LOCATED OVER NRN ND AND SE SASK. TONIGHT...EXPECT ISOLD/SCT -SHRA INTO THE CWA THIS EVENING ASSOCIATED WITH THE MN SHRTWV THAT SHOULD DIMINISH AND END AFTER 03Z. OTHERWISE...WITH ABUNDANT LOW LEVEL MOISTURE OVER THE REGION...PATCHY FOG WILL SHOULD DEVELOP. NNW UPSLOPE 10-15 KNOT 950- 900 MB FLOW INTO N CNTRL UPPER MI MAY ALSO SUPPORT SOME DRIZZLE OVERNIGHT INTO EARLY SUNDAY. SUN...THERE MAY BE SOME ISOLATED LIGHT SHOWERS ASSOCIATED WITH THE SASK/ND SHRTWVS EARLY OVER THE NORTH. OTHERWISE...EXPECT A WEAK SFC RIDGE TO BUILD INTO THE AREA WITH MAINLY LIGHT WINDS ALLOWING LAKE BREEZES TO DEVELOP. MODEL CONSENSUS SHOWS MLCAPE VALUES COULD CLIMB INTO THE 500-1000 J/KG RANGE OVER MAINLY THE SRN CWA FROM NEAR IMT- MNM. THIS MAY BE ENOUGH TO ALLOW SOME SHRA/TSRA TO DEVELOP...ESPECIALLY NEAR THE LAKE MI BREEZE BOUNDARY. WITH LIMITED INSTABILITY FARTHER NORTH AND SOME MID LEVEL CAPPING NEAR 700 MB...NO AFTERNOON PCPN IS EXPECTED OVER THE REST OF THE CWA. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 310 PM EDT SAT JUN 20 2015 UPPER GREAT LAKES REGION WILL STILL BE UNDER THE INFLUENCE OF A HIGH PRESSURE RIDGE AT THE START OF THE LONG TERM PERIOD...BUT ITS INFLUENCE WILL BE SHORT LIVED AS A POTENT SHORTWAVE AND ASSOCIATED LOW PRESSURE SYSTEM WILL SWEEP ACROSS THE AREA ON MONDAY. THE SHORTWAVE THAT WILL AFFECT THE AREA ON MONDAY IS ACTUALLY TWO SEPARATE WAVES AT THIS TIME...ONE OVER BRITISH COLUMBIA AND THE OTHER OVER THE PACIFIC TO THE WEST OF OREGON. THESE TWO WAVES WILL MERGE OVER THE NORTHERN ROCKIES TOMORROW AND THEN QUICKLY SHIFT EAST INTO THE AREA FOR MONDAY. A LOW AVERAGING 1000MB WILL SLIDE NORTHEAST...TRACKING FROM EASTERN WYOMING ON SUNDAY AFTERNOON...TO MINNESOTA ON MONDAY AFTERNOON AND THEN ACROSS THE UPPER GREAT LAKES ON MONDAY NIGHT. MUCH OF THE FORECAST DEPENDS BOTH ON THE TRACK OF THE SHORTWAVE AND THE DEVELOPMENT OF CONVECTION ALONG THE WARM FRONT AHEAD OF THE LOW. LATEST MODEL RUNS SHOW THE SHORTWAVE TRACKING ACROSS SOUTHERN UPPER MICHIGAN OR NORTHERN WISCONSIN...WITH THE WARM FRONT LIKELY LOCATED IN NORTHERN/CENTRAL WISCONSIN. THAT IS CLOSE ENOUGH TO CONTINUE TO SHOW LIKELY TO DEFINITE POPS SPREADING EAST INTO THE AREA ON MONDAY MORNING AND CONTINUING INTO EARLY MONDAY EVENING AS THE MAIN FORCING MOVES THROUGH THE UPPER GREAT LAKES. THE POSITION OF THE WARM FRONT WILL DETERMINE SEVERE WEATHER POTENTIAL...AS THAT WILL BE THE AREA WHERE THE NOSE OF THE 35-40KT 850MB JET AND INSTABILITY GRADIENT WILL BE LOCATED. WHILE SOME MODELS DO TRY TO SHIFT IT NORTH INTO OUR AREA...BELIEVE THAT CONVECTION AND POSSIBLE MCS THAT DEVELOPS UPSTREAM IN MINNESOTA ON SUNDAY NIGHT WILL SUPPRESS THE BOUNDARY FARTHER TO THE SOUTH. ASSUMING THAT OCCURS...THE BETTER INSTABILITY WILL BE WELL TO THE SOUTH OF THE AREA AND THE GRADIENT SOMEWHERE IN CENTRAL/NORTHERN WISCONSIN. THINK THE LATEST DAY 3 OUTLOOK FROM SPC HAS A GOOD HANDLE ON WHERE THE STRONGEST STORMS WILL BE AND GENERALLY TO THE SOUTH OF THE U.P.. WILL CONTINUE TO MENTION SLIGHT/CHANCE THUNDERSTORMS OVER THE SOUTHERN HALF TO TWO-THIRDS OF THE CWA WHICH IS CLOSE ENOUGH TO POTENTIAL EXPERIENCE SOME RUMBLES OF THUNDER. WITH THE DYNAMICS OF THE SYSTEM...IF THE INSTABILITY OR WARM FRONT SHIFTS FARTHER TO THE NORTH...SEVERE STORMS WOULD BE POSSIBLE. AS THE LOW DEPARTS ON MONDAY NIGHT...EXPECT A WEST TO EAST DIMINISHMENT OF POPS AND CLOUD COVER ACROSS THE AREA. HAVE TRENDED WINDS UP BASED OFF ALL OF THE LATEST RUNS...WITH 925MB WINDS AROUND 35KTS. THAT WIND WILL LIMIT THE POTENTIAL FOR FOG ON MONDAY NIGHT ACROSS THE U.P.. THINK THE MAIN AREAS THAT WILL SEE FOG WILL BE ALONG THE LAKE MICHIGAN SHORELINE ON MONDAY EVENING AND SHORELINES ALONG CENTRAL/EASTERN LAKE SUPERIOR AS THE WINDS TURN TO THE NORTHWEST AND PUSH THE FOG ONSHORE. WINDS WILL BE DECREASING ON TUESDAY. THE AREA WILL BE UNDER WEST-NORTHWEST FLOW ALOFT FOR TUESDAY AND WEDNESDAY...AS A HIGH PRESSURE RIDGE MOVES OVER THE AREA FOR TUESDAY AND THEN DEPARTS ON WEDNESDAY AS THE PARENT HIGH MOVES INTO THE OHIO RIVER VALLEY. WHILE THE RIDGE IS OVER THE AREA...EXPECT DRY CONDITIONS AND TEMPERATURES TO BE NEAR NORMAL. THE NEXT SHORTWAVE WILL MOVE THROUGH THE AREA SOMETIME BETWEEN LATE WEDNESDAY AFTERNOON AND THURSDAY...THROUGH THE WEST-NORTHWEST FLOW ALOFT. WITH THE SOURCE REGION...AND THE WARM FRONT SITUATED OVER THE CENTRAL PLAINS...EXPECT MOISTURE TO BE LIMITED AND WILL ONLY INCLUDE SLIGHT/CHANCE POPS FOR THE PASSAGE OF THE WAVE. INSTABILITY IS ALSO LIMITED AND WILL KEEP VALUES CAPPED AT SLIGHT CHANCES...BUT WILL NEED TO WATCH DIURNAL HEATING ON THURSDAY...WHICH COULD INCREASE POTENTIAL SOME. A WEAK HIGH WILL MOVE OVER THE AREA ON THURSDAY NIGHT AND THE FIRST PART OF FRIDAY BEFORE ANOTHER SHORTWAVE DROPS SOUTHEAST INTO THE AREA FOR LATER FRIDAY INTO SATURDAY. WHILE THERE IS THE POTENTIAL FOR RAIN DURING THIS PERIOD...THE MORE NOTABLE ITEM IS THE AMPLIFICATION OF AN UPPER TROUGH OVER THE GREAT LAKES REGION FOR NEXT WEEKEND AND LIKELY CONTINUING INTO NEXT WEEK. BOTH THE ECMWF/GFS ENSEMBLES SUPPORT THAT IDEA...AND EVEN SHOW HINTS OF THAT TROUGH REMAINING IN PLACE TOWARDS THE FOURTH OF JULY. IF THAT SETUP OCCURS...THE U.P. WOULD EXPERIENCE A COOL AND DRY PERIOD OF WEATHER FOR THE END OF JUNE AND START OF JULY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 136 PM EDT SAT JUN 20 2015 RAIN THIS AFTERNOON IS EXPECTED TO TAPER OFF TOWARD EVENING...BUT LOW LEVEL MOISTENING WILL RESULT IN CIGS DROPPING TO MVFR THIS AFTERNOON AND LIKELY TO IFR THIS EVENING AND OVERNIGHT AS WINDS REMAIN LIGHT. CONFIDENCE IS LOWER WHETHER CONDITIONS WILL DROP TO LIFR/VLIFR. SOME IMPROVEMENT IS POSSIBLE BY MID TO LATE SUN MORNING WITH DAYTIME HEATING/MIXING. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 420 PM EDT SAT JUN 20 2015 TYPICAL SUMMERTIME CONDITIONS WITH GENERALLY LIGHT WINDS WILL DOMINATE ACROSS LAKE SUPERIOR THROUGH THE FCST PERIOD. WITH WEAK HIGH PRES BUILDING INTO THE AREA BEHIND THE DISTURBANCE MOVING OUT OF THE AREA TONIGHT...LIGHTER WINDS WILL FOLLOW FOR THE LAST HALF THE WEEKEND. THESE LIGHT WINDS...UNDER 20KT...WILL LIKELY CONTINUE THRU THE FIRST HALF OF NEXT WEEK AS A WEAK SUMMERTIME PRES GRADIENT SHOULD PREVAIL. THE RAIN TODAY WILL SUPPORT FOG ACROSS THE LAKE...THAT COULD BE LOCALLY DENSE. EXPECT THE FOG TO LINGER INTO EARLY NEXT WEEK DUE TO A LACK OF STRONG ADVECTION OF DRIER AIR. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...SRF AVIATION...JLB MARINE...JLB
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1248 PM EDT SAT JUN 20 2015 .AVIATION... OBSERVATIONS LEADING UP TO FORECAST ISSUANCE SHOWED IMPROVEMENT IN CEILING THROUGH THE DTW CORRIDOR WHICH IS EXPECTED TO CONTINUE THROUGH THE AFTERNOON. STRATUS WILL LIFT AND CHANGE INTO A VFR CUMULUS CEILING IN THAT AREA UNDER A MIX OF HIGH CLOUDS LEFT OVER FROM UPSTREAM CONVECTION THAT WILL COVER THE REST OF THE NORTHERN TERMINALS. VFR WILL THEN CONTINUE THROUGH THE EVENING LEAVING POSSIBLE THUNDERSTORM DEVELOPMENT OVERNIGHT AS THE MAIN AVIATION CONCERN. AT THIS POINT...STORMS COULD MOVE IN FROM THE AREA OF WISCONSIN/ILLINOIS AS PART OF NEW AFTERNOON ACTIVITY THERE...OR DEVELOP OVERHEAD AS HUMIDITY INCREASES FURTHER OVER SE MICHIGAN DURING THE NIGHT. BOTH SITUATIONS ARE LOOSELY TIMED AFTER MIDNIGHT WITH COVERAGE REQUIRING REFINEMENT BEFORE ADDITION TO THE FORECAST. AFTER THAT...BORDERLINE IFR/MVFR CEILING IS LIKELY TO DEVELOP IN THE WARM/HUMID AIR MASS AHEAD OF THE FRONT SETTLING INTO LOWER MICHIGAN SUNDAY MORNING. //DTW THRESHOLD PROBABILITIES... * MEDIUM POTENTIAL FOR CEILING OF 5000 FEET OR LESS TODAY AND SUNDAY MORNING. * LOW POTENTIAL FOR THUNDERSTORMS AFTER APPROXIMATELY 03Z THROUGH TONIGHT. && .PREV DISCUSSION...ISSUED 1107 AM EDT SAT JUN 20 2015 UPDATE... EARLIER UPDATE NUDGED CHANCE OF SHOWERS NORTHWARD TOWARD M-59 CORRIDOR BASED ON RADAR TRENDS. WEAK ACTIVITY CONTINUES DUE TO ADVECTIVE PROCESSES WITHIN THE MOISTURE GRADIENT ON THE NORTHWEST FLANK OF TROPICAL REMNANTS. DISSIPATION OVER OUR AREA WILL OCCUR DUE TO VEERING LOW TO MID LEVEL FLOW AS THE REMNANTS MOVE EASTWARD. THIS WILL ALLOW THE MID LEVEL THETA-E TROUGH THAT IS OVER CENTRAL LOWER MICHIGAN TO SLIDE MORE TOWARD THE OHIO BORDER. LOWER CLOUDS MAY BE A BIT MORE STUBBORN THAN THE SHOWERS BUT EXPECT SOME MODEST IMPROVEMENT IN A COMBINATION OF DISSIPATING STRATUS AND REDEVELOPMENT OF CUMULUS BY LATE AFTERNOON. PREV DISCUSSION...ISSUED 352 AM EDT SAT JUN 20 2015 SHORT TERM...TODAY AND TONIGHT VERY DRY COLUMN THROUGH THE DEPTH OF THE TROPOSPHERE IS ENTRENCHED OVER SOUTHEAST MICHIGAN PER 00Z DTX RAOB. LOWEST 6KFT OR SO CAN BE EXPECTED TO BECOME INCREASINGLY SATURATED OVER THE NEXT SEVERAL HOURS AS SHARP THETA-E GRADIENT LIFTS INTO THE AREA AS TROPICAL REMNANTS LIFT NORTHEAST ALONG THE OHIO RIVER. A LOW COVERAGE OF SHOWERS DISPLACED NORTHWARD FROM CENTER OF CIRCULATION IS NOTED ON REGIONAL RADAR MOSAIC OVER CENTRAL INDIANA. 00Z NWP REMAIN INSISTENT THAT THIS ACTIVITY WILL INCREASE IN COVERAGE, AND 05Z HRRR REMAINS BULLISH AT PRESS TIME. THE PRIMARY FORCING APPEARS TO BE WEAK THETA- E ADVECTION AND A MODEST COMPONENT OF MID-LEVEL DEFORMATION. AT 0730Z SHOWERS WERE NOTED INCREASING IN COVERAGE OVER NORTHERN INDIANA, WARRANTING THE ADVERTISED LOW CHC POP SOUTH OF THE METRO AREA THROUGH MID MORNING. GREATER SENSIBLE WX IMPACT WILL LIKELY BE EXTENSIVE CLOUDS, WHICH WILL AGGRESSIVELY LIFT INTO THE SOUTH OF M59 FOR MUCH OF THE DAY BEFORE DIURNAL HEATING ALLOWS FOR SOME BREAKS BY MID AFTERNOON. THETA-E TROUGH WILL HOLD FOR MOST OF THE DAY ACROSS THE NORTH, ENSURING DRY AND MOSTLY SUNNY CONDITIONS ACROSS THE NORTHERN COUNTIES. NO COMPLAINTS WITH 00Z TEMPERATURE GUIDANCE WHICH SUGGESTS 77-80F AREAWIDE, WARMEST IN THE SAGINAW VALLEY. FORECAST BECOMES MORE NUANCED LATE THIS EVENING THROUGH TONIGHT. CORE OF ENHANCED MID-LEVEL WESTERLIES AND ATTENDANT HEIGHT FALLS WILL PUSH INTO LOWER MICHIGAN FROM THE WEST. REMNANTS OF PERHAPS THE CLEANEST EML OF THE SEASON WILL FOLD ACROSS THE CWA AFTER 21Z WITH A HEALTHY PLUME OF DEEP 7C/KM MID-LEVEL LAPSE RATES POSSIBLE DEPENDING ON MODULATION BY UPSTREAM CONVECTION BEFORE IT ADVECTS INTO THE AREA. REMNANTS OF UPSTREAM CONVECTION MAY HOLD TOGETHER ALONG THE LEAD EDGE OF THE HIGHER MID-LEVEL LAPSE RATES, WARRANTING CHC POPS AS EARLY AS THIS EVENING. SEVERE THREAT DURING THIS TIME WILL REMAIN WELL UPSTREAM AND MOST LIKELY CONFINED TO THE NEIGHBORHOOD OF THE INSTABILITY GRADIENT OVER PORTIONS OF THE MIDDLE/UPPER MS VALLEY. LOCALLY, LOW-LEVEL JET WILL CONTRIBUTE TO AN INCREASINGLY VEERED WIND PROFILE AND POTENTIAL MODERATE ELEVATED NOCTURNAL DESTABILIZATION AS THE LOWER PORTION OF THE COLUMN WARMS BENEATH STEEPER LAPSE RATES. BULK SHEAR WITHIN THE ELEVATED/EFFECTIVE LAYER SHOULD EASILY HOLD IN THE 35KT RANGE, SO AT LEAST A LOWER END THREAT FOR ROTATING UPDRAFTS CAPABLE OF PRODUCING SEVERE HAIL EXISTS ACROSS THE ENTIRE AREA THROUGH TONIGHT. LONG TERM... SUNDAY THROUGH FRIDAY QUASI-ZONAL LOW AMPLITUDE MID LEVEL WEST/WNW FLOW WILL LARGELY DICTATE CONDITIONS LOCALLY RIGHT THROUGH THE EARLY WEEK PERIOD. FLOW RIPE WITH WEAK IMPULSES AND ASSOCIATED UPPER JET MAXIMA OF CENTRAL PACIFIC ORIGIN WILL MAINTAIN AN INTERMITTENTLY ACTIVE STRETCH OF WEATHER THROUGH THE LONG TERM PERIOD. THIS PATTERN WILL TEND TO FAVOR A GENERALLY SEASONABLE TEMPERATURE REGIME GIVEN LIMITED DAY TO DAY VARIATION IN THE GOVERNING THICKNESS/HEIGHT FIELD AND LACK OF GREATER MEAN AMPLITUDE. ILL-DEFINED SHORTWAVE ENERGY WILL BE PROGRESSING THROUGH LOWER MICHIGAN EARLY SUNDAY...ANCHORED WITHIN A NARROW REGION OF LEFT EXIT REGION UPPER JET DYNAMICS. ATTENDANT SURFACE WAVE/COLD FRONTAL STRUCTURE WILL TRAIL THE LEAD HEIGHT FALLS...THE MOST FAVORED FRONTAL TIMING LOCALLY PER RECENT MODEL GUIDANCE COMMENCING DURING THE MIDDAY PERIOD. WHILE THE DEEPEST MOISTURE PLUME WILL EXIT EASTWARD BY MID MORNING...MOISTURE QUALITY THROUGH 700 MB REMAINS RESPECTABLE WITH GREATER POST-FRONTAL DRY AIR ADVECTION NOT TAKING A STRONGER HOLD UNTIL MID-LATE AFTERNOON. THE OVERALL FRONTAL TIMING AND LIMITED ENSUING COLD AIR ADVECTION INITIALLY WILL ALLOW HIGHS TO PUSH 80F/LOWER 80S. THIS IN CONJUNCTION WITH STEEPER MID LEVEL LAPSE RATES WILL PROVIDE A MODEST DEGREE OF INSTABILITY. THIS WILL LEAVE A WINDOW FOR SOME DEGREE OF RENEWED CONVECTIVE DEVELOPMENT DURING THE DAYLIGHT PERIOD...ALLOWING FOR A COMBINATION OF FRONTAL CONVERGENCE AND MID LEVEL ASCENT ACCOMPANYING FAVORABLE UPPER JET FORCING/HEIGHT FALLS TO CAPITALIZE ON DIURNAL DESTABILIZATION. BRIEF PERIOD OF DRIER AND MORE STABLE CONDITIONS SUNDAY NIGHT AND EARLY MONDAY WITH THE REGION BETWEEN MID LEVEL WAVES AND UNDER THE INFLUENCE OF SURFACE RIDGING. NEXT INBOUND SHORTWAVE WILL ELICIT A MORE PRONOUNCED LOW LEVEL RESPONSE RELATIVE TO EARLIER IMPULSES... A PERIOD OF GREATER SURFACE CYCLOGENESIS EMERGING AS THE SYSTEM LIFTS OUT OF THE PLAINS ON MONDAY. THIS LOW IS FORECAST TO EJECT NORTHEAST MONDAY AND MONDAY NIGHT...REACHING NORTHERN LAKE HURON BY EARLY TUESDAY MORNING. STEADY INCREASE IN LOW-MID LEVEL WARM AIR ADVECTION LOCALLY THROUGHOUT MONDAY AS SOUTHWEST FLOW STRENGTHENS DOWNSTREAM OF THIS SYSTEM. ACCOMPANYING UPTICK IN MOISTURE TRANSPORT APPEARS TO LAG IN TIMING...INITIAL PERIOD OF MID LEVEL MOISTURE ADVECTION ON MONDAY AND ANY ENSUING DESTABILIZATION LACKING DEPTH TO SUPPORT GREATER CONVECTIVE POTENTIAL PRIOR TO 21Z. WILL LEAN THE FORECAST DRIER ACCORDINGLY THROUGH THE FIRST HALF OF THE DAY. HIGHS ON MONDAY CENTERED ON THE LOWER AND MIDDLE 80S. STRONGEST PRE-FRONTAL FORCING WILL TEND TO ARC FROM NORTHERN WISCONSIN BACK THROUGH CHICAGO BY MONDAY AFTERNOON...POSITIONING OF THE STRONGEST 850 MB FLOW FAVORING CONVECTIVE EXPANSION TOWARD THE EAST/NORTHEAST INTO THE EVENING HOURS. THIS WILL LEAVE AT LEAST NORTHERN PORTIONS OF THE FORECAST AREA VULNERABLE TO ANY LEAD CONVECTIVE CLUSTERS EMBEDDED WITHIN THE INCREASING PRE-FRONTAL CONVERGENCE ZONE FOCUSED JUST UPSTREAM. POTENTIAL DOES EXIST FOR GREATER UPSCALE GROWTH INTO A MORE SIZABLE/SEVERE MCS ACROSS LOWER MICHIGAN MONDAY EVENING...PARTICULARLY SHOULD THE TIMING ALLOW FOR GREATER DESTABILIZATION TO OCCUR IMMEDIATELY DOWNSTREAM. SOLID WIND FIELD IN PLACE TO SUPPORT GREATER CONVECTIVE ORGANIZATION... QUESTION AGAIN CENTERS ON THE DEGREE OF INSTABILITY. AS NOTED IN THE LATEST SPC DAY3 OUTLOOK...ECMWF NOT NEARLY AS ROBUST RELATIVE TO THE GFS/NAM WITH EITHER THE DYNAMICS OR THERMODYNAMIC ENVIRONMENT... SO PLENTY OF UNCERTAINTY YET IN DEFINING THE SEVERE POTENTIAL/ MAGNITUDE WITHIN THIS SETUP. MARINE... LIGHT SOUTHEAST FLOW ACROSS ALL MARINE AREAS TODAY AS WEAKENING HIGH PRESSURE SLIDES ACROSS THE REGION. COLD FRONT TRACKING ACROSS THE REGION WILL BRING A CHANCE FOR THUNDERSTORMS TONIGHT AND SUNDAY. MODEST WEST TO NORTHWEST WINDS WILL DEVELOP ON SUNDAY WITH THE FRONTAL PASSAGE. WINDS QUICKLY DIMINISH SUNDAY EVENING AS THE NEXT RIDGE OF HIGH PRESSURE BUILDS ACROSS THE REGION. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MICHIGAN WATERS OF LAKE ERIE...NONE. && $$ AVIATION.....BT UPDATE.......BT SHORT TERM...JVC LONG TERM....MR MARINE.......MR YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1107 AM EDT SAT JUN 20 2015 .UPDATE... EARLIER UPDATE NUDGED CHANCE OF SHOWERS NORTHWARD TOWARD M-59 CORRIDOR BASED ON RADAR TRENDS. WEAK ACTIVITY CONTINUES DUE TO ADVECTIVE PROCESSES WITHIN THE MOISTURE GRADIENT ON THE NORTHWEST FLANK OF TROPICAL REMNANTS. DISSIPATION OVER OUR AREA WILL OCCUR DUE TO VEERING LOW TO MID LEVEL FLOW AS THE REMNANTS MOVE EASTWARD. THIS WILL ALLOW THE MID LEVEL THETA-E TROUGH THAT IS OVER CENTRAL LOWER MICHIGAN TO SLIDE MORE TOWARD THE OHIO BORDER. LOWER CLOUDS MAY BE A BIT MORE STUBBORN THAN THE SHOWERS BUT EXPECT SOME MODEST IMPROVEMENT IN A COMBINATION OF DISSIPATING STRATUS AND REDEVELOPMENT OF CUMULUS BY LATE AFTERNOON. && .AVIATION...ISSUED 550 AM EDT SAT JUN 20 2015 PARTIAL COVERAGE OF SHOWERS BLOSSOMED OVER NORTHERN IN/OH EARLY THIS MORNING AND WILL POTENTIALLY BRING A PASSING SHOWER TO THE IMMEDIATE DETROIT TAF SITES THROUGH 15Z. BIGGER AVIATION CONCERN WILL BE PERSISTENT MVFR CIGS THAT WILL HOLD FIRM WELL INTO THE AFTERNOON ONCE THEY ARRIVE NEAR OR SHORTLY AFTER FORECAST ISSUANCE TIME. DIURNAL HEATING SHOULD ALLOW SOME BREAKS TO DEVELOP BUT EXPECT CEILING TO PERSIST REGARDLESS. WINDS WILL GRADUALLY VEER FROM NE THIS MORNING TO SSE TONIGHT. POSSIBILITY EXISTS FOR THUNDERSTORMS TONIGHT AS MORE UNSTABLE AIR SPREADS INTO SE MICHIGAN BUT CONFIDENCE IN BOTH DEVELOPMENT AND COVERAGE REMAINS ON THE LOW END ATTM. BEST CHANCE WOULD BE ROUGHLY 03-09Z. //DTW THRESHOLD PROBABILITIES... * HIGH CONFIDENCE IN CIG AOB 5KFT * LOW CONFIDENCE THAT A TSTORM WILL IMPACT KDTW AIRSPACE AFTER APPROX 03Z. && .PREV DISCUSSION...ISSUED 352 AM EDT SAT JUN 20 2015 SHORT TERM...TODAY AND TONIGHT VERY DRY COLUMN THROUGH THE DEPTH OF THE TROPOSPHERE IS ENTRENCHED OVER SOUTHEAST MICHIGAN PER 00Z DTX RAOB. LOWEST 6KFT OR SO CAN BE EXPECTED TO BECOME INCREASINGLY SATURATED OVER THE NEXT SEVERAL HOURS AS SHARP THETA-E GRADIENT LIFTS INTO THE AREA AS TROPICAL REMNANTS LIFT NORTHEAST ALONG THE OHIO RIVER. A LOW COVERAGE OF SHOWERS DISPLACED NORTHWARD FROM CENTER OF CIRCULATION IS NOTED ON REGIONAL RADAR MOSAIC OVER CENTRAL INDIANA. 00Z NWP REMAIN INSISTENT THAT THIS ACTIVITY WILL INCREASE IN COVERAGE, AND 05Z HRRR REMAINS BULLISH AT PRESS TIME. THE PRIMARY FORCING APPEARS TO BE WEAK THETA- E ADVECTION AND A MODEST COMPONENT OF MID-LEVEL DEFORMATION. AT 0730Z SHOWERS WERE NOTED INCREASING IN COVERAGE OVER NORTHERN INDIANA, WARRANTING THE ADVERTISED LOW CHC POP SOUTH OF THE METRO AREA THROUGH MID MORNING. GREATER SENSIBLE WX IMPACT WILL LIKELY BE EXTENSIVE CLOUDS, WHICH WILL AGGRESSIVELY LIFT INTO THE SOUTH OF M59 FOR MUCH OF THE DAY BEFORE DIURNAL HEATING ALLOWS FOR SOME BREAKS BY MID AFTERNOON. THETA-E TROUGH WILL HOLD FOR MOST OF THE DAY ACROSS THE NORTH, ENSURING DRY AND MOSTLY SUNNY CONDITIONS ACROSS THE NORTHERN COUNTIES. NO COMPLAINTS WITH 00Z TEMPERATURE GUIDANCE WHICH SUGGESTS 77-80F AREAWIDE, WARMEST IN THE SAGINAW VALLEY. FORECAST BECOMES MORE NUANCED LATE THIS EVENING THROUGH TONIGHT. CORE OF ENHANCED MID-LEVEL WESTERLIES AND ATTENDANT HEIGHT FALLS WILL PUSH INTO LOWER MICHIGAN FROM THE WEST. REMNANTS OF PERHAPS THE CLEANEST EML OF THE SEASON WILL FOLD ACROSS THE CWA AFTER 21Z WITH A HEALTHY PLUME OF DEEP 7C/KM MID-LEVEL LAPSE RATES POSSIBLE DEPENDING ON MODULATION BY UPSTREAM CONVECTION BEFORE IT ADVECTS INTO THE AREA. REMNANTS OF UPSTREAM CONVECTION MAY HOLD TOGETHER ALONG THE LEAD EDGE OF THE HIGHER MID-LEVEL LAPSE RATES, WARRANTING CHC POPS AS EARLY AS THIS EVENING. SEVERE THREAT DURING THIS TIME WILL REMAIN WELL UPSTREAM AND MOST LIKELY CONFINED TO THE NEIGHBORHOOD OF THE INSTABILITY GRADIENT OVER PORTIONS OF THE MIDDLE/UPPER MS VALLEY. LOCALLY, LOW-LEVEL JET WILL CONTRIBUTE TO AN INCREASINGLY VEERED WIND PROFILE AND POTENTIAL MODERATE ELEVATED NOCTURNAL DESTABILIZATION AS THE LOWER PORTION OF THE COLUMN WARMS BENEATH STEEPER LAPSE RATES. BULK SHEAR WITHIN THE ELEVATED/EFFECTIVE LAYER SHOULD EASILY HOLD IN THE 35KT RANGE, SO AT LEAST A LOWER END THREAT FOR ROTATING UPDRAFTS CAPABLE OF PRODUCING SEVERE HAIL EXISTS ACROSS THE ENTIRE AREA THROUGH TONIGHT. LONG TERM... SUNDAY THROUGH FRIDAY QUASI-ZONAL LOW AMPLITUDE MID LEVEL WEST/WNW FLOW WILL LARGELY DICTATE CONDITIONS LOCALLY RIGHT THROUGH THE EARLY WEEK PERIOD. FLOW RIPE WITH WEAK IMPULSES AND ASSOCIATED UPPER JET MAXIMA OF CENTRAL PACIFIC ORIGIN WILL MAINTAIN AN INTERMITTENTLY ACTIVE STRETCH OF WEATHER THROUGH THE LONG TERM PERIOD. THIS PATTERN WILL TEND TO FAVOR A GENERALLY SEASONABLE TEMPERATURE REGIME GIVEN LIMITED DAY TO DAY VARIATION IN THE GOVERNING THICKNESS/HEIGHT FIELD AND LACK OF GREATER MEAN AMPLITUDE. ILL-DEFINED SHORTWAVE ENERGY WILL BE PROGRESSING THROUGH LOWER MICHIGAN EARLY SUNDAY...ANCHORED WITHIN A NARROW REGION OF LEFT EXIT REGION UPPER JET DYNAMICS. ATTENDANT SURFACE WAVE/COLD FRONTAL STRUCTURE WILL TRAIL THE LEAD HEIGHT FALLS...THE MOST FAVORED FRONTAL TIMING LOCALLY PER RECENT MODEL GUIDANCE COMMENCING DURING THE MIDDAY PERIOD. WHILE THE DEEPEST MOISTURE PLUME WILL EXIT EASTWARD BY MID MORNING...MOISTURE QUALITY THROUGH 700 MB REMAINS RESPECTABLE WITH GREATER POST-FRONTAL DRY AIR ADVECTION NOT TAKING A STRONGER HOLD UNTIL MID-LATE AFTERNOON. THE OVERALL FRONTAL TIMING AND LIMITED ENSUING COLD AIR ADVECTION INITIALLY WILL ALLOW HIGHS TO PUSH 80F/LOWER 80S. THIS IN CONJUNCTION WITH STEEPER MID LEVEL LAPSE RATES WILL PROVIDE A MODEST DEGREE OF INSTABILITY. THIS WILL LEAVE A WINDOW FOR SOME DEGREE OF RENEWED CONVECTIVE DEVELOPMENT DURING THE DAYLIGHT PERIOD...ALLOWING FOR A COMBINATION OF FRONTAL CONVERGENCE AND MID LEVEL ASCENT ACCOMPANYING FAVORABLE UPPER JET FORCING/HEIGHT FALLS TO CAPITALIZE ON DIURNAL DESTABILIZATION. BRIEF PERIOD OF DRIER AND MORE STABLE CONDITIONS SUNDAY NIGHT AND EARLY MONDAY WITH THE REGION BETWEEN MID LEVEL WAVES AND UNDER THE INFLUENCE OF SURFACE RIDGING. NEXT INBOUND SHORTWAVE WILL ELICIT A MORE PRONOUNCED LOW LEVEL RESPONSE RELATIVE TO EARLIER IMPULSES... A PERIOD OF GREATER SURFACE CYCLOGENESIS EMERGING AS THE SYSTEM LIFTS OUT OF THE PLAINS ON MONDAY. THIS LOW IS FORECAST TO EJECT NORTHEAST MONDAY AND MONDAY NIGHT...REACHING NORTHERN LAKE HURON BY EARLY TUESDAY MORNING. STEADY INCREASE IN LOW-MID LEVEL WARM AIR ADVECTION LOCALLY THROUGHOUT MONDAY AS SOUTHWEST FLOW STRENGTHENS DOWNSTREAM OF THIS SYSTEM. ACCOMPANYING UPTICK IN MOISTURE TRANSPORT APPEARS TO LAG IN TIMING...INITIAL PERIOD OF MID LEVEL MOISTURE ADVECTION ON MONDAY AND ANY ENSUING DESTABILIZATION LACKING DEPTH TO SUPPORT GREATER CONVECTIVE POTENTIAL PRIOR TO 21Z. WILL LEAN THE FORECAST DRIER ACCORDINGLY THROUGH THE FIRST HALF OF THE DAY. HIGHS ON MONDAY CENTERED ON THE LOWER AND MIDDLE 80S. STRONGEST PRE-FRONTAL FORCING WILL TEND TO ARC FROM NORTHERN WISCONSIN BACK THROUGH CHICAGO BY MONDAY AFTERNOON...POSITIONING OF THE STRONGEST 850 MB FLOW FAVORING CONVECTIVE EXPANSION TOWARD THE EAST/NORTHEAST INTO THE EVENING HOURS. THIS WILL LEAVE AT LEAST NORTHERN PORTIONS OF THE FORECAST AREA VULNERABLE TO ANY LEAD CONVECTIVE CLUSTERS EMBEDDED WITHIN THE INCREASING PRE-FRONTAL CONVERGENCE ZONE FOCUSED JUST UPSTREAM. POTENTIAL DOES EXIST FOR GREATER UPSCALE GROWTH INTO A MORE SIZABLE/SEVERE MCS ACROSS LOWER MICHIGAN MONDAY EVENING...PARTICULARLY SHOULD THE TIMING ALLOW FOR GREATER DESTABILIZATION TO OCCUR IMMEDIATELY DOWNSTREAM. SOLID WIND FIELD IN PLACE TO SUPPORT GREATER CONVECTIVE ORGANIZATION... QUESTION AGAIN CENTERS ON THE DEGREE OF INSTABILITY. AS NOTED IN THE LATEST SPC DAY3 OUTLOOK...ECMWF NOT NEARLY AS ROBUST RELATIVE TO THE GFS/NAM WITH EITHER THE DYNAMICS OR THERMODYNAMIC ENVIRONMENT... SO PLENTY OF UNCERTAINTY YET IN DEFINING THE SEVERE POTENTIAL/ MAGNITUDE WITHIN THIS SETUP. MARINE... LIGHT SOUTHEAST FLOW ACROSS ALL MARINE AREAS TODAY AS WEAKENING HIGH PRESSURE SLIDES ACROSS THE REGION. COLD FRONT TRACKING ACROSS THE REGION WILL BRING A CHANCE FOR THUNDERSTORMS TONIGHT AND SUNDAY. MODEST WEST TO NORTHWEST WINDS WILL DEVELOP ON SUNDAY WITH THE FRONTAL PASSAGE. WINDS QUICKLY DIMINISH SUNDAY EVENING AS THE NEXT RIDGE OF HIGH PRESSURE BUILDS ACROSS THE REGION. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MICHIGAN WATERS OF LAKE ERIE...NONE. && $$ UPDATE.......BT AVIATION.....JVC SHORT TERM...JVC LONG TERM....MR MARINE.......MR YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
550 AM EDT SAT JUN 20 2015 .AVIATION... PARTIAL COVERAGE OF SHOWERS BLOSSOMED OVER NORTHERN IN/OH EARLY THIS MORNING AND WILL POTENTIALLY BRING A PASSING SHOWER TO THE IMMEDIATE DETROIT TAF SITES THROUGH 15Z. BIGGER AVIATION CONCERN WILL BE PERSISTENT MVFR CIGS THAT WILL HOLD FIRM WELL INTO THE AFTERNOON ONCE THEY ARRIVE NEAR OR SHORTLY AFTER FORECAST ISSUANCE TIME. DIURNAL HEATING SHOULD ALLOW SOME BREAKS TO DEVELOP BUT EXPECT CEILING TO PERSIST REGARDLESS. WINDS WILL GRADUALLY VEER FROM NE THIS MORNING TO SSE TONIGHT. POSSIBILITY EXISTS FOR THUNDERSTORMS TONIGHT AS MORE UNSTABLE AIR SPREADS INTO SE MICHIGAN BUT CONFIDENCE IN BOTH DEVELOPMENT AND COVERAGE REMAINS ON THE LOW END ATTM. BEST CHANCE WOULD BE ROUGHLY 03-09Z. //DTW THRESHOLD PROBABILITIES... * HIGH CONFIDENCE IN CIG AOB 5KFT * LOW CONFIDENCE THAT A TSTORM WILL IMPACT KDTW AIRSPACE AFTER APPROX 03Z. && .PREV DISCUSSION...ISSUED 352 AM EDT SAT JUN 20 2015 SHORT TERM...TODAY AND TONIGHT VERY DRY COLUMN THROUGH THE DEPTH OF THE TROPOSPHERE IS ENTRENCHED OVER SOUTHEAST MICHIGAN PER 00Z DTX RAOB. LOWEST 6KFT OR SO CAN BE EXPECTED TO BECOME INCREASINGLY SATURATED OVER THE NEXT SEVERAL HOURS AS SHARP THETA-E GRADIENT LIFTS INTO THE AREA AS TROPICAL REMNANTS LIFT NORTHEAST ALONG THE OHIO RIVER. A LOW COVERAGE OF SHOWERS DISPLACED NORTHWARD FROM CENTER OF CIRCULATION IS NOTED ON REGIONAL RADAR MOSAIC OVER CENTRAL INDIANA. 00Z NWP REMAIN INSISTENT THAT THIS ACTIVITY WILL INCREASE IN COVERAGE, AND 05Z HRRR REMAINS BULLISH AT PRESS TIME. THE PRIMARY FORCING APPEARS TO BE WEAK THETA- E ADVECTION AND A MODEST COMPONENT OF MID-LEVEL DEFORMATION. AT 0730Z SHOWERS WERE NOTED INCREASING IN COVERAGE OVER NORTHERN INDIANA, WARRANTING THE ADVERTISED LOW CHC POP SOUTH OF THE METRO AREA THROUGH MID MORNING. GREATER SENSIBLE WX IMPACT WILL LIKELY BE EXTENSIVE CLOUDS, WHICH WILL AGGRESSIVELY LIFT INTO THE SOUTH OF M59 FOR MUCH OF THE DAY BEFORE DIURNAL HEATING ALLOWS FOR SOME BREAKS BY MID AFTERNOON. THETA-E TROUGH WILL HOLD FOR MOST OF THE DAY ACROSS THE NORTH, ENSURING DRY AND MOSTLY SUNNY CONDITIONS ACROSS THE NORTHERN COUNTIES. NO COMPLAINTS WITH 00Z TEMPERATURE GUIDANCE WHICH SUGGESTS 77-80F AREAWIDE, WARMEST IN THE SAGINAW VALLEY. FORECAST BECOMES MORE NUANCED LATE THIS EVENING THROUGH TONIGHT. CORE OF ENHANCED MID-LEVEL WESTERLIES AND ATTENDANT HEIGHT FALLS WILL PUSH INTO LOWER MICHIGAN FROM THE WEST. REMNANTS OF PERHAPS THE CLEANEST EML OF THE SEASON WILL FOLD ACROSS THE CWA AFTER 21Z WITH A HEALTHY PLUME OF DEEP 7C/KM MID-LEVEL LAPSE RATES POSSIBLE DEPENDING ON MODULATION BY UPSTREAM CONVECTION BEFORE IT ADVECTS INTO THE AREA. REMNANTS OF UPSTREAM CONVECTION MAY HOLD TOGETHER ALONG THE LEAD EDGE OF THE HIGHER MID-LEVEL LAPSE RATES, WARRANTING CHC POPS AS EARLY AS THIS EVENING. SEVERE THREAT DURING THIS TIME WILL REMAIN WELL UPSTREAM AND MOST LIKELY CONFINED TO THE NEIGHBORHOOD OF THE INSTABILITY GRADIENT OVER PORTIONS OF THE MIDDLE/UPPER MS VALLEY. LOCALLY, LOW-LEVEL JET WILL CONTRIBUTE TO AN INCREASINGLY VEERED WIND PROFILE AND POTENTIAL MODERATE ELEVATED NOCTURNAL DESTABILIZATION AS THE LOWER PORTION OF THE COLUMN WARMS BENEATH STEEPER LAPSE RATES. BULK SHEAR WITHIN THE ELEVATED/EFFECTIVE LAYER SHOULD EASILY HOLD IN THE 35KT RANGE, SO AT LEAST A LOWER END THREAT FOR ROTATING UPDRAFTS CAPABLE OF PRODUCING SEVERE HAIL EXISTS ACROSS THE ENTIRE AREA THROUGH TONIGHT. LONG TERM... SUNDAY THROUGH FRIDAY QUASI-ZONAL LOW AMPLITUDE MID LEVEL WEST/WNW FLOW WILL LARGELY DICTATE CONDITIONS LOCALLY RIGHT THROUGH THE EARLY WEEK PERIOD. FLOW RIPE WITH WEAK IMPULSES AND ASSOCIATED UPPER JET MAXIMA OF CENTRAL PACIFIC ORIGIN WILL MAINTAIN AN INTERMITTENTLY ACTIVE STRETCH OF WEATHER THROUGH THE LONG TERM PERIOD. THIS PATTERN WILL TEND TO FAVOR A GENERALLY SEASONABLE TEMPERATURE REGIME GIVEN LIMITED DAY TO DAY VARIATION IN THE GOVERNING THICKNESS/HEIGHT FIELD AND LACK OF GREATER MEAN AMPLITUDE. ILL-DEFINED SHORTWAVE ENERGY WILL BE PROGRESSING THROUGH LOWER MICHIGAN EARLY SUNDAY...ANCHORED WITHIN A NARROW REGION OF LEFT EXIT REGION UPPER JET DYNAMICS. ATTENDANT SURFACE WAVE/COLD FRONTAL STRUCTURE WILL TRAIL THE LEAD HEIGHT FALLS...THE MOST FAVORED FRONTAL TIMING LOCALLY PER RECENT MODEL GUIDANCE COMMENCING DURING THE MIDDAY PERIOD. WHILE THE DEEPEST MOISTURE PLUME WILL EXIT EASTWARD BY MID MORNING...MOISTURE QUALITY THROUGH 700 MB REMAINS RESPECTABLE WITH GREATER POST-FRONTAL DRY AIR ADVECTION NOT TAKING A STRONGER HOLD UNTIL MID-LATE AFTERNOON. THE OVERALL FRONTAL TIMING AND LIMITED ENSUING COLD AIR ADVECTION INITIALLY WILL ALLOW HIGHS TO PUSH 80F/LOWER 80S. THIS IN CONJUNCTION WITH STEEPER MID LEVEL LAPSE RATES WILL PROVIDE A MODEST DEGREE OF INSTABILITY. THIS WILL LEAVE A WINDOW FOR SOME DEGREE OF RENEWED CONVECTIVE DEVELOPMENT DURING THE DAYLIGHT PERIOD...ALLOWING FOR A COMBINATION OF FRONTAL CONVERGENCE AND MID LEVEL ASCENT ACCOMPANYING FAVORABLE UPPER JET FORCING/HEIGHT FALLS TO CAPITALIZE ON DIURNAL DESTABILIZATION. BRIEF PERIOD OF DRIER AND MORE STABLE CONDITIONS SUNDAY NIGHT AND EARLY MONDAY WITH THE REGION BETWEEN MID LEVEL WAVES AND UNDER THE INFLUENCE OF SURFACE RIDGING. NEXT INBOUND SHORTWAVE WILL ELICIT A MORE PRONOUNCED LOW LEVEL RESPONSE RELATIVE TO EARLIER IMPULSES... A PERIOD OF GREATER SURFACE CYCLOGENESIS EMERGING AS THE SYSTEM LIFTS OUT OF THE PLAINS ON MONDAY. THIS LOW IS FORECAST TO EJECT NORTHEAST MONDAY AND MONDAY NIGHT...REACHING NORTHERN LAKE HURON BY EARLY TUESDAY MORNING. STEADY INCREASE IN LOW-MID LEVEL WARM AIR ADVECTION LOCALLY THROUGHOUT MONDAY AS SOUTHWEST FLOW STRENGTHENS DOWNSTREAM OF THIS SYSTEM. ACCOMPANYING UPTICK IN MOISTURE TRANSPORT APPEARS TO LAG IN TIMING...INITIAL PERIOD OF MID LEVEL MOISTURE ADVECTION ON MONDAY AND ANY ENSUING DESTABILIZATION LACKING DEPTH TO SUPPORT GREATER CONVECTIVE POTENTIAL PRIOR TO 21Z. WILL LEAN THE FORECAST DRIER ACCORDINGLY THROUGH THE FIRST HALF OF THE DAY. HIGHS ON MONDAY CENTERED ON THE LOWER AND MIDDLE 80S. STRONGEST PRE-FRONTAL FORCING WILL TEND TO ARC FROM NORTHERN WISCONSIN BACK THROUGH CHICAGO BY MONDAY AFTERNOON...POSITIONING OF THE STRONGEST 850 MB FLOW FAVORING CONVECTIVE EXPANSION TOWARD THE EAST/NORTHEAST INTO THE EVENING HOURS. THIS WILL LEAVE AT LEAST NORTHERN PORTIONS OF THE FORECAST AREA VULNERABLE TO ANY LEAD CONVECTIVE CLUSTERS EMBEDDED WITHIN THE INCREASING PRE-FRONTAL CONVERGENCE ZONE FOCUSED JUST UPSTREAM. POTENTIAL DOES EXIST FOR GREATER UPSCALE GROWTH INTO A MORE SIZABLE/SEVERE MCS ACROSS LOWER MICHIGAN MONDAY EVENING...PARTICULARLY SHOULD THE TIMING ALLOW FOR GREATER DESTABILIZATION TO OCCUR IMMEDIATELY DOWNSTREAM. SOLID WIND FIELD IN PLACE TO SUPPORT GREATER CONVECTIVE ORGANIZATION... QUESTION AGAIN CENTERS ON THE DEGREE OF INSTABILITY. AS NOTED IN THE LATEST SPC DAY3 OUTLOOK...ECMWF NOT NEARLY AS ROBUST RELATIVE TO THE GFS/NAM WITH EITHER THE DYNAMICS OR THERMODYNAMIC ENVIRONMENT... SO PLENTY OF UNCERTAINTY YET IN DEFINING THE SEVERE POTENTIAL/ MAGNITUDE WITHIN THIS SETUP. MARINE... LIGHT SOUTHEAST FLOW ACROSS ALL MARINE AREAS TODAY AS WEAKENING HIGH PRESSURE SLIDES ACROSS THE REGION. COLD FRONT TRACKING ACROSS THE REGION WILL BRING A CHANCE FOR THUNDERSTORMS TONIGHT AND SUNDAY. MODEST WEST TO NORTHWEST WINDS WILL DEVELOP ON SUNDAY WITH THE FRONTAL PASSAGE. WINDS QUICKLY DIMINISH SUNDAY EVENING AS THE NEXT RIDGE OF HIGH PRESSURE BUILDS ACROSS THE REGION. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MICHIGAN WATERS OF LAKE ERIE...NONE. && $$ AVIATION.....JVC SHORT TERM...JVC LONG TERM....MR MARINE.......MR YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
352 AM EDT SAT JUN 20 2015 .SHORT TERM...TODAY AND TONIGHT VERY DRY COLUMN THROUGH THE DEPTH OF THE TROPOSPHERE IS ENTRENCHED OVER SOUTHEAST MICHIGAN PER 00Z DTX RAOB. LOWEST 6KFT OR SO CAN BE EXPECTED TO BECOME INCREASINGLY SATURATED OVER THE NEXT SEVERAL HOURS AS SHARP THETA-E GRADIENT LIFTS INTO THE AREA AS TROPICAL REMNANTS LIFT NORTHEAST ALONG THE OHIO RIVER. A LOW COVERAGE OF SHOWERS DISPLACED NORTHWARD FROM CENTER OF CIRCULATION IS NOTED ON REGIONAL RADAR MOSAIC OVER CENTRAL INDIANA. 00Z NWP REMAIN INSISTENT THAT THIS ACTIVITY WILL INCREASE IN COVERAGE, AND 05Z HRRR REMAINS BULLISH AT PRESS TIME. THE PRIMARY FORCING APPEARS TO BE WEAK THETA- E ADVECTION AND A MODEST COMPONENT OF MID-LEVEL DEFORMATION. AT 0730Z SHOWERS WERE NOTED INCREASING IN COVERAGE OVER NORTHERN INDIANA, WARRANTING THE ADVERTISED LOW CHC POP SOUTH OF THE METRO AREA THROUGH MID MORNING. GREATER SENSIBLE WX IMPACT WILL LIKELY BE EXTENSIVE CLOUDS, WHICH WILL AGGRESSIVELY LIFT INTO THE SOUTH OF M59 FOR MUCH OF THE DAY BEFORE DIURNAL HEATING ALLOWS FOR SOME BREAKS BY MID AFTERNOON. THETA-E TROUGH WILL HOLD FOR MOST OF THE DAY ACROSS THE NORTH, ENSURING DRY AND MOSTLY SUNNY CONDITIONS ACROSS THE NORTHERN COUNTIES. NO COMPLAINTS WITH 00Z TEMPERATURE GUIDANCE WHICH SUGGESTS 77-80F AREAWIDE, WARMEST IN THE SAGINAW VALLEY. FORECAST BECOMES MORE NUANCED LATE THIS EVENING THROUGH TONIGHT. CORE OF ENHANCED MID-LEVEL WESTERLIES AND ATTENDANT HEIGHT FALLS WILL PUSH INTO LOWER MICHIGAN FROM THE WEST. REMNANTS OF PERHAPS THE CLEANEST EML OF THE SEASON WILL FOLD ACROSS THE CWA AFTER 21Z WITH A HEALTHY PLUME OF DEEP 7C/KM MID-LEVEL LAPSE RATES POSSIBLE DEPENDING ON MODULATION BY UPSTREAM CONVECTION BEFORE IT ADVECTS INTO THE AREA. REMNANTS OF UPSTREAM CONVECTION MAY HOLD TOGETHER ALONG THE LEAD EDGE OF THE HIGHER MID-LEVEL LAPSE RATES, WARRANTING CHC POPS AS EARLY AS THIS EVENING. SEVERE THREAT DURING THIS TIME WILL REMAIN WELL UPSTREAM AND MOST LIKELY CONFINED TO THE NEIGHBORHOOD OF THE INSTABILITY GRADIENT OVER PORTIONS OF THE MIDDLE/UPPER MS VALLEY. LOCALLY, LOW-LEVEL JET WILL CONTRIBUTE TO AN INCREASINGLY VEERED WIND PROFILE AND POTENTIAL MODERATE ELEVATED NOCTURNAL DESTABILIZATION AS THE LOWER PORTION OF THE COLUMN WARMS BENEATH STEEPER LAPSE RATES. BULK SHEAR WITHIN THE ELEVATED/EFFECTIVE LAYER SHOULD EASILY HOLD IN THE 35KT RANGE, SO AT LEAST A LOWER END THREAT FOR ROTATING UPDRAFTS CAPABLE OF PRODUCING SEVERE HAIL EXISTS ACROSS THE ENTIRE AREA THROUGH TONIGHT. && .LONG TERM... SUNDAY THROUGH FRIDAY QUASI-ZONAL LOW AMPLITUDE MID LEVEL WEST/WNW FLOW WILL LARGELY DICTATE CONDITIONS LOCALLY RIGHT THROUGH THE EARLY WEEK PERIOD. FLOW RIPE WITH WEAK IMPULSES AND ASSOCIATED UPPER JET MAXIMA OF CENTRAL PACIFIC ORIGIN WILL MAINTAIN AN INTERMITTENTLY ACTIVE STRETCH OF WEATHER THROUGH THE LONG TERM PERIOD. THIS PATTERN WILL TEND TO FAVOR A GENERALLY SEASONABLE TEMPERATURE REGIME GIVEN LIMITED DAY TO DAY VARIATION IN THE GOVERNING THICKNESS/HEIGHT FIELD AND LACK OF GREATER MEAN AMPLITUDE. ILL-DEFINED SHORTWAVE ENERGY WILL BE PROGRESSING THROUGH LOWER MICHIGAN EARLY SUNDAY...ANCHORED WITHIN A NARROW REGION OF LEFT EXIT REGION UPPER JET DYNAMICS. ATTENDANT SURFACE WAVE/COLD FRONTAL STRUCTURE WILL TRAIL THE LEAD HEIGHT FALLS...THE MOST FAVORED FRONTAL TIMING LOCALLY PER RECENT MODEL GUIDANCE COMMENCING DURING THE MIDDAY PERIOD. WHILE THE DEEPEST MOISTURE PLUME WILL EXIT EASTWARD BY MID MORNING...MOISTURE QUALITY THROUGH 700 MB REMAINS RESPECTABLE WITH GREATER POST-FRONTAL DRY AIR ADVECTION NOT TAKING A STRONGER HOLD UNTIL MID-LATE AFTERNOON. THE OVERALL FRONTAL TIMING AND LIMITED ENSUING COLD AIR ADVECTION INITIALLY WILL ALLOW HIGHS TO PUSH 80F/LOWER 80S. THIS IN CONJUNCTION WITH STEEPER MID LEVEL LAPSE RATES WILL PROVIDE A MODEST DEGREE OF INSTABILITY. THIS WILL LEAVE A WINDOW FOR SOME DEGREE OF RENEWED CONVECTIVE DEVELOPMENT DURING THE DAYLIGHT PERIOD...ALLOWING FOR A COMBINATION OF FRONTAL CONVERGENCE AND MID LEVEL ASCENT ACCOMPANYING FAVORABLE UPPER JET FORCING/HEIGHT FALLS TO CAPITALIZE ON DIURNAL DESTABILIZATION. BRIEF PERIOD OF DRIER AND MORE STABLE CONDITIONS SUNDAY NIGHT AND EARLY MONDAY WITH THE REGION BETWEEN MID LEVEL WAVES AND UNDER THE INFLUENCE OF SURFACE RIDGING. NEXT INBOUND SHORTWAVE WILL ILLICIT A MORE PRONOUNCED LOW LEVEL RESPONSE RELATIVE TO EARLIER IMPULSES...A PERIOD OF GREATER SURFACE CYCLOGENESIS EMERGING AS THE SYSTEM LIFTS OUT OF THE PLAINS ON MONDAY. THIS LOW IS FORECAST TO EJECT NORTHEAST MONDAY AND MONDAY NIGHT...REACHING NORTHERN LAKE HURON BY EARLY TUESDAY MORNING. STEADY INCREASE IN LOW-MID LEVEL WARM AIR ADVECTION LOCALLY THROUGHOUT MONDAY AS SOUTHWEST FLOW STRENGTHENS DOWNSTREAM OF THIS SYSTEM. ACCOMPANYING UPTICK IN MOISTURE TRANSPORT APPEARS TO LAG IN TIMING...INITIAL PERIOD OF MID LEVEL MOISTURE ADVECTION ON MONDAY AND ANY ENSUING DESTABILIZATION LACKING DEPTH TO SUPPORT GREATER CONVECTIVE POTENTIAL PRIOR TO 21Z. WILL LEAN THE FORECAST DRIER ACCORDINGLY THROUGH THE FIRST HALF OF THE DAY. HIGHS ON MONDAY CENTERED ON THE LOWER AND MIDDLE 80S. STRONGEST PRE-FRONTAL FORCING WILL TEND TO ARC FROM NORTHERN WISCONSIN BACK THROUGH CHICAGO BY MONDAY AFTERNOON...POSITIONING OF THE STRONGEST 850 MB FLOW FAVORING CONVECTIVE EXPANSION TOWARD THE EAST/NORTHEAST INTO THE EVENING HOURS. THIS WILL LEAVE AT LEAST NORTHERN PORTIONS OF THE FORECAST AREA VULNERABLE TO ANY LEAD CONVECTIVE CLUSTERS EMBEDDED WITHIN THE INCREASING PRE-FRONTAL CONVERGENCE ZONE FOCUSED JUST UPSTREAM. POTENTIAL DOES EXIST FOR GREATER UPSCALE GROWTH INTO A MORE SIZABLE/SEVERE MCS ACROSS LOWER MICHIGAN MONDAY EVENING...PARTICULARLY SHOULD THE TIMING ALLOW FOR GREATER DESTABILIZATION TO OCCUR IMMEDIATELY DOWNSTREAM. SOLID WIND FIELD IN PLACE TO SUPPORT GREATER CONVECTIVE ORGANIZATION... QUESTION AGAIN CENTERS ON THE DEGREE OF INSTABILITY. AS NOTED IN THE LATEST SPC DAY3 OUTLOOK...ECMWF NOT NEARLY AS ROBUST RELATIVE TO THE GFS/NAM WITH EITHER THE DYNAMICS OR THERMODYNAMIC ENVIRONMENT... SO PLENTY OF UNCERTAINTY YET IN DEFINING THE SEVERE POTENTIAL/ MAGNITUDE WITHIN THIS SETUP. && .MARINE... LIGHT SOUTHEAST FLOW ACROSS ALL MARINE AREAS TODAY AS WEAKENING HIGH PRESSURE SLIDES ACROSS THE REGION. COLD FRONT TRACKING ACROSS THE REGION WILL BRING A CHANCE FOR THUNDERSTORMS TONIGHT AND SUNDAY. MODEST WEST TO NORTHWEST WINDS WILL DEVELOP ON SUNDAY WITH THE FRONTAL PASSAGE. WINDS QUICKLY DIMINISH SUNDAY EVENING AS THE NEXT RIDGE OF HIGH PRESSURE BUILDS ACROSS THE REGION. && .AVIATION...ISSUED 1221 AM EDT SAT JUN 20 2015 QUIET AVIATION WEATHER WILL CONTINUE THROUGHOUT THE NIGHT WITH A SURFACE HIGH PRESSURE RIDGE AXIS PARKED OVER LAKE HURON. AS THE RIDGE STRIPS OUT WITH SURFACE HIGH PRESSURE BUILDING EASTWARD...RETURN SOUTHERLY FLOW WILL INCREASE. WATCHING A BAND OF SHOWERS SLOWLY LIFT NORTHWARD ACROSS PORTIONS OF CENTRAL IN/OH. MODELS SUGGEST THERE IS SOME LOW POTENTIAL FOR SHOWERS TO LIFT TO AROUND THE MI/OH STATE LINE VERY LATE TONIGHT. NEVERTHELESS...EXPECTING DRY CONDITIONS AT DTW. MODELS REMAIN BULLISH IN MVFR STRATUS/STRATOCUMULUS DECK LIFTING INTO SECTIONS ALOGN AND SOUTH OF M59 TOMORROW MORNING AND ONLY SLOWLY EVOLVING/LIFTING TO CUMULUS. MVFR CONDITIONS ARE LIKELY INTO THE AFTERNOON HOURS. //DTW THRESHOLD PROBABILITIES... * HIGH CONFIDENCE WITH CIGS BELOW 5000 FEET AFTER 11Z SATURDAY MORNING AND PERSISTING INTO THE AFTERNOON. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MICHIGAN WATERS OF LAKE ERIE...NONE. && $$ SHORT TERM...JVC LONG TERM....MR MARINE.......MR AVIATION.....JVC YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
135 AM EDT SAT JUN 20 2015 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 357 PM EDT FRI JUN 19 2015 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF OVER THE PACIFIC NW/SW CANADA...SUBTLE RIDGING OVER MT/WY INTO THE WRN DAKOTAS AND WEAK TROFFING INTO NEW ENGLAND. LOW-LEVEL JET OVER THE WRN HIGH PLAINS FUELED SHRA/TSRA ACROSS THE DAKOTAS EARLY TODAY. MUCH OF THAT PCPN HAS SINCE DISSIPATED...BUT REMNANTS ARE STRENGTHENING AGAIN OVER ERN SD. OTHER REMNANT SHRA ARE MOVING ACROSS NW MN/SRN SASKATCHEWAN AND JUST ACROSS THE BORDER INTO NRN ONTARIO. CLOSER TO HOME...SFC HIGH PRES OVER THE UPPER LAKES IS PROVIDING A PLEASANT MID JUN AFTN ACROSS THE AREA. AFTER ABUNDANT SUNSHINE EARLIER TODAY...CU BLOSSOMED OVER THE E...BUT THOSE CLOUDS ARE NOW DISSIPATING. SCT-BKN MOSTLY THIN HIGH CLOUDS ARE ALSO STREAMING INTO PARTS OF THE AREA. QUIET WEATHER WILL BEGIN THE SHORT TERM WITH LINGERING DRY AIR MASS ASSOCIATED WITH SFC HIGH PRES MOVING FROM THE UPPER GREAT LAKES THIS AFTN TO NEW ENGLAND BY SAT MORNING. LATER TONIGHT AND INTO SAT... ATTENTION TURNS TO A COMPLEX SERIES OF SHORTWAVES STREAKING ACROSS THE NRN CONUS/SRN CANADA. IT APPEARS THAT THERE IS A SUBTLE WAVE SUPPORTING THE SHRA ACTIVITY CURRENTLY IN NW MN/SRN SASKATCHEWAN. THIS WAVE MAY CONTINUE TO AID SHRA AND MAYBE SOME TSRA INTO NRN LAKE SUPERIOR/ADJACENT NRN ONTARIO TONIGHT. ON THE NOSE OF THE 850MB THETA-E RIDGE WITH LOW-LEVEL JET INCREASING DURING THE NIGHT...THIS ACTIVITY MAY TEND TO INCREASE SOME AS THE NIGHT PROGRESSES. THE UNCERTAINTY IS IN WHETHER THIS CONVECTION WILL BUILD S FAR ENOUGH TO IMPACT NW UPPER MI LATE TONIGHT. MUCH OF THE MODEL GUIDANCE SUGGESTS PCPN WILL STAY N OF THE AREA. GIVEN PROXIMITY OF LOW-LEVEL JET/THETA- E AXIS...WILL MAINTAIN A SCHC MENTION INTO FAR WRN UPPER MI LATE TONIGHT. FARTHER W...THERE IS A CONSISTENT SIGNAL IN ALL MODEL GUIDANCE THAT ANOTHER CLUSTER OF SHRA/TSRA WILL DEVELOP/EXPAND IN THE ERN DAKOTAS/MN TONIGHT AHEAD OF ANOTHER SHORTWAVE...ON THE NOSE OF A STRONGER PORTION OF THE STRENGTHENING LOW-LEVEL JET AND THE ON NRN EDGE OF STRONG INSTABILITY OVER THE PLAINS. THIS ACTIVITY SHOULD STILL BE W OF UPPER MI AT 12Z SAT. FCST ON SAT WILL HINGE SOMEWHAT ON WHAT DEVELOPS OUT OF THE CONVECTION TO THE W TONIGHT. IF A SFC LOW CONVECTIVELY SPINS UP AND MOVES ACROSS NRN WI...IT COULD SUPPORT A LARGE AREA OF SHRA AND SOME ISOLD EMBEDDED THUNDER SPREADING E ACROSS THE FCST AREA DURING THE DAY. IT`S NOT CLEAR IF THAT WILL OCCUR. IN ANY EVENT...SHORTWAVE MOVING THRU THE UPPER LAKES SHOULD SUPPORT A GOOD POTENTIAL OF SHRA SPREADING W TO E ACROSS THE AREA SAT. IN GENERAL...LIKELY POPS LOOK REASONABLE. SINCE THE GFS HAS PULLED BACK ON INSTABILITY TO BECOME SIMILAR TO THE NAM IN SHOWING ALMOST NO INSTABILITY DEVELOPING INTO UPPER MI ON SAT...NOT EXPECTING ANY SVR STORMS SAT. LATEST DAY2 OUTLOOK FROM SPC HAS ALSO SHIFTED MRGL RISK FARTHER S INTO CNTRL WI AS WELL. IF FOR SOME REASON CLOUDS BREAK ALLOWING A BUILDING OF INSTABILITY...THEN THERE COULD BE SOME SVR STORMS SINCE DEEP LAYER SHEAR IS FCST TO BE IN EXCESS OF 50KT. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 441 PM EDT FRI JUN 19 2015 A ZONAL PATTERN WILL ALLOW A SERIES OF SHORTWAVES TO MOVE THROUGH THE NRN CONUS. AS THE RIDGE BUILDS OVER THE SW CONUS TOWARD THE END OF THE WEEK...A TRANSITION TOWARD MORE NW FLOW IS EXPECTED. TEMPS WILL GENERALLY REMAIN AT OR SLIGHTLY BELOW NORMAL WITH THE MAIN FRONTAL BOUNDARY REMAINING TO THE SOUTH OF THE REGION. SAT NIGHT...THE MODELS HAVE TRENDED SLIGHTLY SLOWER WITH THE PROGRESSION OF THE SHORTWAVE TROUGH AND ASSOCIATED PCPN. EXPECT SCT/NMRS SHRA OVER THE EAST HALF DURING THE EVENING TO MOVE OUT OF MOST OF THE CWA BY LATE EVENING BUT MAY LINGER OVER THE EAST AFT 03Z/SUN. NAM FCST MUCPE VALUES IN THE 300-600 J/KG RANGE MAY SUPPORT SOME ISOLD TSRA. OTHERWISE...SOME DRIZZLE MAY DEVELOP INTO N CNTRL UPPER MI WITH LINGERING LOW LEVEL MOISTURE AND UPSLOPE NRLY FLOW DEVELOPING BEHIND THE SFC TROUGH. SUN...EXPECT WEAK SFC RIDGE TO BUILD INTO THE AREA WITH MAINLY LIGHT WINDS ALLOWING LAKE BREEZES TO DEVELOP. ALTHOUGH MLCAPE MLCAPE VALUES INTO THE 500-1000 J/KG RANGE MAY BE POSSIBLE...MID LEVEL CAPPING QVECTOR/DIV SUBSIDENCE OVER THE AREA WILL NOT BE FAVORABLE FOR SHRA/TSRA DEVELOPMENT. SUN NIGHT AND MONDAY...ANOTHER SHORTWAVE TROUGH WILL MOVE THROUGH THE NRN LAKES WITH A PERIOD OF MODERATE TO STRONG QVECTOR CONV. ALTHOUGH ONLY CHANCE POPS WERE MENTIONED FOR NOW...MODEL TRENDS TOWARD A STRONGER/SLOWER SHRTWV SUGGESTS POPS MAY INCREASE CLOSER TO THE SHRA/TSRA EVENT. TUE-FRI...THE PROGRESSIVE PATTERN WILL FAVOR ADDITIONAL SHORTWAVES MOVING INTO THE AREA. HOWEVER...THE TIMING/STRENGTH OF ANY OF THESE FEATURES IS MORE DIFFICULT TO DETERMINE. SO...MODELS CONSENSUS LOWER END CHANCE POPS PREVAIL THROUGH THE PERIOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 134 AM EDT SAT JUN 20 2015 VFR CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW THRU SAT MORNING. INCREASING WINDS OVER NOCTURNAL INVERSION WILL RESULT IN MARGINAL LLWS AT KIWD/KCMX OVERNIGHT. ON SAT...AREA OF SHRA SHOULD SPREAD E INTO UPPER MI...AFFECTING KIWD/KCMX IN THE MORNING. ARRIVAL OF HEAVIER PCPN SAT AFTERNOON WILL DROP ALL SITES TO MVFR CONDITIONS AND THEN TO IFR LATER IN THE AFTERNOON WHICH WILL LAST INTO SAT EVENING. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 357 PM EDT FRI JUN 19 2015 TYPICAL SUMMERTIME CONDITIONS WITH GENERALLY LIGHT WINDS WILL DOMINATE ACROSS LAKE SUPERIOR THRU THIS FCST PERIOD. STRONGEST WINDS WILL PROBABLY OCCUR TONIGHT THRU SAT MORNING AHEAD OF AN APPROACHING DISTURBANCE. OVER THE E HALF OF THE LAKE WHICH IS FAVORED FOR STRONGEST WINDS IN THIS TYPE OF PATTERN...S WINDS WILL LIKELY GUST TO AROUND 20KT AT TIMES. THE HIGHEST OBS PLATFORMS WILL PROBABLY GUST TO AROUND 30KT. WITH ONLY WEAK HIGH PRES BUILDING INTO THE AREA BEHIND THE DISTURBANCE...LIGHTER WINDS WILL FOLLOW FOR THE LAST HALF THE WEEKEND. THESE LIGHT WINDS...UNDER 20KT...WILL LIKELY CONTINUE THRU THE FIRST HALF OF NEXT WEEK AS A WEAK SUMMERTIME PRES GRADIENT SHOULD PREVAIL. EXPECTED RAINFALL SAT SHOULD RESULT IN SOME FOG DEVELOPING ACROSS THE LAKE...AND THE FOG COULD BECOME LOCALLY DENSE. IF THE FOG DOES IN FACT DEVELOP...FOG PATCHES MAY LINGER INTO EARLY NEXT WEEK DUE TO A LACK OF STRONG ADVECTION OF DRIER AIR. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...JLB AVIATION...07 MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
715 PM EDT FRI JUN 19 2015 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 357 PM EDT FRI JUN 19 2015 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF OVER THE PACIFIC NW/SW CANADA...SUBTLE RIDGING OVER MT/WY INTO THE WRN DAKOTAS AND WEAK TROFFING INTO NEW ENGLAND. LOW-LEVEL JET OVER THE WRN HIGH PLAINS FUELED SHRA/TSRA ACROSS THE DAKOTAS EARLY TODAY. MUCH OF THAT PCPN HAS SINCE DISSIPATED...BUT REMNANTS ARE STRENGTHENING AGAIN OVER ERN SD. OTHER REMNANT SHRA ARE MOVING ACROSS NW MN/SRN SASKATCHEWAN AND JUST ACROSS THE BORDER INTO NRN ONTARIO. CLOSER TO HOME...SFC HIGH PRES OVER THE UPPER LAKES IS PROVIDING A PLEASANT MID JUN AFTN ACROSS THE AREA. AFTER ABUNDANT SUNSHINE EARLIER TODAY...CU BLOSSOMED OVER THE E...BUT THOSE CLOUDS ARE NOW DISSIPATING. SCT-BKN MOSTLY THIN HIGH CLOUDS ARE ALSO STREAMING INTO PARTS OF THE AREA. QUIET WEATHER WILL BEGIN THE SHORT TERM WITH LINGERING DRY AIR MASS ASSOCIATED WITH SFC HIGH PRES MOVING FROM THE UPPER GREAT LAKES THIS AFTN TO NEW ENGLAND BY SAT MORNING. LATER TONIGHT AND INTO SAT... ATTENTION TURNS TO A COMPLEX SERIES OF SHORTWAVES STREAKING ACROSS THE NRN CONUS/SRN CANADA. IT APPEARS THAT THERE IS A SUBTLE WAVE SUPPORTING THE SHRA ACTIVITY CURRENTLY IN NW MN/SRN SASKATCHEWAN. THIS WAVE MAY CONTINUE TO AID SHRA AND MAYBE SOME TSRA INTO NRN LAKE SUPERIOR/ADJACENT NRN ONTARIO TONIGHT. ON THE NOSE OF THE 850MB THETA-E RIDGE WITH LOW-LEVEL JET INCREASING DURING THE NIGHT...THIS ACTIVITY MAY TEND TO INCREASE SOME AS THE NIGHT PROGRESSES. THE UNCERTAINTY IS IN WHETHER THIS CONVECTION WILL BUILD S FAR ENOUGH TO IMPACT NW UPPER MI LATE TONIGHT. MUCH OF THE MODEL GUIDANCE SUGGESTS PCPN WILL STAY N OF THE AREA. GIVEN PROXIMITY OF LOW-LEVEL JET/THETA- E AXIS...WILL MAINTAIN A SCHC MENTION INTO FAR WRN UPPER MI LATE TONIGHT. FARTHER W...THERE IS A CONSISTENT SIGNAL IN ALL MODEL GUIDANCE THAT ANOTHER CLUSTER OF SHRA/TSRA WILL DEVELOP/EXPAND IN THE ERN DAKOTAS/MN TONIGHT AHEAD OF ANOTHER SHORTWAVE...ON THE NOSE OF A STRONGER PORTION OF THE STRENGTHENING LOW-LEVEL JET AND THE ON NRN EDGE OF STRONG INSTABILITY OVER THE PLAINS. THIS ACTIVITY SHOULD STILL BE W OF UPPER MI AT 12Z SAT. FCST ON SAT WILL HINGE SOMEWHAT ON WHAT DEVELOPS OUT OF THE CONVECTION TO THE W TONIGHT. IF A SFC LOW CONVECTIVELY SPINS UP AND MOVES ACROSS NRN WI...IT COULD SUPPORT A LARGE AREA OF SHRA AND SOME ISOLD EMBEDDED THUNDER SPREADING E ACROSS THE FCST AREA DURING THE DAY. IT`S NOT CLEAR IF THAT WILL OCCUR. IN ANY EVENT...SHORTWAVE MOVING THRU THE UPPER LAKES SHOULD SUPPORT A GOOD POTENTIAL OF SHRA SPREADING W TO E ACROSS THE AREA SAT. IN GENERAL...LIKELY POPS LOOK REASONABLE. SINCE THE GFS HAS PULLED BACK ON INSTABILITY TO BECOME SIMILAR TO THE NAM IN SHOWING ALMOST NO INSTABILITY DEVELOPING INTO UPPER MI ON SAT...NOT EXPECTING ANY SVR STORMS SAT. LATEST DAY2 OUTLOOK FROM SPC HAS ALSO SHIFTED MRGL RISK FARTHER S INTO CNTRL WI AS WELL. IF FOR SOME REASON CLOUDS BREAK ALLOWING A BUILDING OF INSTABILITY...THEN THERE COULD BE SOME SVR STORMS SINCE DEEP LAYER SHEAR IS FCST TO BE IN EXCESS OF 50KT. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 441 PM EDT FRI JUN 19 2015 A ZONAL PATTERN WILL ALLOW A SERIES OF SHORTWAVES TO MOVE THROUGH THE NRN CONUS. AS THE RIDGE BUILDS OVER THE SW CONUS TOWARD THE END OF THE WEEK...A TRANSITION TOWARD MORE NW FLOW IS EXPECTED. TEMPS WILL GENERALLY REMAIN AT OR SLIGHTLY BELOW NORMAL WITH THE MAIN FRONTAL BOUNDARY REMAINING TO THE SOUTH OF THE REGION. SAT NIGHT...THE MODELS HAVE TRENDED SLIGHTLY SLOWER WITH THE PROGRESSION OF THE SHORTWAVE TROUGH AND ASSOCIATED PCPN. EXPECT SCT/NMRS SHRA OVER THE EAST HALF DURING THE EVENING TO MOVE OUT OF MOST OF THE CWA BY LATE EVENING BUT MAY LINGER OVER THE EAST AFT 03Z/SUN. NAM FCST MUCPE VALUES IN THE 300-600 J/KG RANGE MAY SUPPORT SOME ISOLD TSRA. OTHERWISE...SOME DRIZZLE MAY DEVELOP INTO N CNTRL UPPER MI WITH LINGERING LOW LEVEL MOISTURE AND UPSLOPE NRLY FLOW DEVELOPING BEHIND THE SFC TROUGH. SUN...EXPECT WEAK SFC RIDGE TO BUILD INTO THE AREA WITH MAINLY LIGHT WINDS ALLOWING LAKE BREEZES TO DEVELOP. ALTHOUGH MLCAPE MLCAPE VALUES INTO THE 500-1000 J/KG RANGE MAY BE POSSIBLE...MID LEVEL CAPPING QVECTOR/DIV SUBSIDENCE OVER THE AREA WILL NOT BE FAVORABLE FOR SHRA/TSRA DEVELOPMENT. SUN NIGHT AND MONDAY...ANOTHER SHORTWAVE TROUGH WILL MOVE THROUGH THE NRN LAKES WITH A PERIOD OF MODERATE TO STRONG QVECTOR CONV. ALTHOUGH ONLY CHANCE POPS WERE MENTIONED FOR NOW...MODEL TRENDS TOWARD A STRONGER/SLOWER SHRTWV SUGGESTS POPS MAY INCREASE CLOSER TO THE SHRA/TSRA EVENT. TUE-FRI...THE PROGRESSIVE PATTERN WILL FAVOR ADDITIONAL SHORTWAVES MOVING INTO THE AREA. HOWEVER...THE TIMING/STRENGTH OF ANY OF THESE FEATURES IS MORE DIFFICULT TO DETERMINE. SO...MODELS CONSENSUS LOWER END CHANCE POPS PREVAIL THROUGH THE PERIOD. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING) ISSUED AT 715 PM EDT FRI JUN 19 2015 VFR CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW THRU SAT MORNING. INCREASING WINDS OVER NOCTURNAL INVERSION WILL RESULT IN MARGINAL LLWS AT KIWD/KCMX TONIGHT. ON SAT...AREA OF SHRA SHOULD SPREAD E INTO UPPER MI...AFFECTING KIWD/KCMX IN THE MORNING. ARRIVAL OF HEAVIER PCPN SAT AFTERNOON WILL DROP ALL SITES TO MVFR CONDITIONS. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 357 PM EDT FRI JUN 19 2015 TYPICAL SUMMERTIME CONDITIONS WITH GENERALLY LIGHT WINDS WILL DOMINATE ACROSS LAKE SUPERIOR THRU THIS FCST PERIOD. STRONGEST WINDS WILL PROBABLY OCCUR TONIGHT THRU SAT MORNING AHEAD OF AN APPROACHING DISTURBANCE. OVER THE E HALF OF THE LAKE WHICH IS FAVORED FOR STRONGEST WINDS IN THIS TYPE OF PATTERN...S WINDS WILL LIKELY GUST TO AROUND 20KT AT TIMES. THE HIGHEST OBS PLATFORMS WILL PROBABLY GUST TO AROUND 30KT. WITH ONLY WEAK HIGH PRES BUILDING INTO THE AREA BEHIND THE DISTURBANCE...LIGHTER WINDS WILL FOLLOW FOR THE LAST HALF THE WEEKEND. THESE LIGHT WINDS...UNDER 20KT...WILL LIKELY CONTINUE THRU THE FIRST HALF OF NEXT WEEK AS A WEAK SUMMERTIME PRES GRADIENT SHOULD PREVAIL. EXPECTED RAINFALL SAT SHOULD RESULT IN SOME FOG DEVELOPING ACROSS THE LAKE...AND THE FOG COULD BECOME LOCALLY DENSE. IF THE FOG DOES IN FACT DEVELOP...FOG PATCHES MAY LINGER INTO EARLY NEXT WEEK DUE TO A LACK OF STRONG ADVECTION OF DRIER AIR. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...JLB AVIATION...07 MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
442 PM EDT FRI JUN 19 2015 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 357 PM EDT FRI JUN 19 2015 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF OVER THE PACIFIC NW/SW CANADA...SUBTLE RIDGING OVER MT/WY INTO THE WRN DAKOTAS AND WEAK TROFFING INTO NEW ENGLAND. LOW-LEVEL JET OVER THE WRN HIGH PLAINS FUELED SHRA/TSRA ACROSS THE DAKOTAS EARLY TODAY. MUCH OF THAT PCPN HAS SINCE DISSIPATED...BUT REMNANTS ARE STRENGTHENING AGAIN OVER ERN SD. OTHER REMNANT SHRA ARE MOVING ACROSS NW MN/SRN SASKATCHEWAN AND JUST ACROSS THE BORDER INTO NRN ONTARIO. CLOSER TO HOME...SFC HIGH PRES OVER THE UPPER LAKES IS PROVIDING A PLEASANT MID JUN AFTN ACROSS THE AREA. AFTER ABUNDANT SUNSHINE EARLIER TODAY...CU BLOSSOMED OVER THE E...BUT THOSE CLOUDS ARE NOW DISSIPATING. SCT-BKN MOSTLY THIN HIGH CLOUDS ARE ALSO STREAMING INTO PARTS OF THE AREA. QUIET WEATHER WILL BEGIN THE SHORT TERM WITH LINGERING DRY AIR MASS ASSOCIATED WITH SFC HIGH PRES MOVING FROM THE UPPER GREAT LAKES THIS AFTN TO NEW ENGLAND BY SAT MORNING. LATER TONIGHT AND INTO SAT... ATTENTION TURNS TO A COMPLEX SERIES OF SHORTWAVES STREAKING ACROSS THE NRN CONUS/SRN CANADA. IT APPEARS THAT THERE IS A SUBTLE WAVE SUPPORTING THE SHRA ACTIVITY CURRENTLY IN NW MN/SRN SASKATCHEWAN. THIS WAVE MAY CONTINUE TO AID SHRA AND MAYBE SOME TSRA INTO NRN LAKE SUPERIOR/ADJACENT NRN ONTARIO TONIGHT. ON THE NOSE OF THE 850MB THETA-E RIDGE WITH LOW-LEVEL JET INCREASING DURING THE NIGHT...THIS ACTIVITY MAY TEND TO INCREASE SOME AS THE NIGHT PROGRESSES. THE UNCERTAINTY IS IN WHETHER THIS CONVECTION WILL BUILD S FAR ENOUGH TO IMPACT NW UPPER MI LATE TONIGHT. MUCH OF THE MODEL GUIDANCE SUGGESTS PCPN WILL STAY N OF THE AREA. GIVEN PROXIMITY OF LOW-LEVEL JET/THETA- E AXIS...WILL MAINTAIN A SCHC MENTION INTO FAR WRN UPPER MI LATE TONIGHT. FARTHER W...THERE IS A CONSISTENT SIGNAL IN ALL MODEL GUIDANCE THAT ANOTHER CLUSTER OF SHRA/TSRA WILL DEVELOP/EXPAND IN THE ERN DAKOTAS/MN TONIGHT AHEAD OF ANOTHER SHORTWAVE...ON THE NOSE OF A STRONGER PORTION OF THE STRENGTHENING LOW-LEVEL JET AND THE ON NRN EDGE OF STRONG INSTABILITY OVER THE PLAINS. THIS ACTIVITY SHOULD STILL BE W OF UPPER MI AT 12Z SAT. FCST ON SAT WILL HINGE SOMEWHAT ON WHAT DEVELOPS OUT OF THE CONVECTION TO THE W TONIGHT. IF A SFC LOW CONVECTIVELY SPINS UP AND MOVES ACROSS NRN WI...IT COULD SUPPORT A LARGE AREA OF SHRA AND SOME ISOLD EMBEDDED THUNDER SPREADING E ACROSS THE FCST AREA DURING THE DAY. IT`S NOT CLEAR IF THAT WILL OCCUR. IN ANY EVENT...SHORTWAVE MOVING THRU THE UPPER LAKES SHOULD SUPPORT A GOOD POTENTIAL OF SHRA SPREADING W TO E ACROSS THE AREA SAT. IN GENERAL...LIKELY POPS LOOK REASONABLE. SINCE THE GFS HAS PULLED BACK ON INSTABILITY TO BECOME SIMILAR TO THE NAM IN SHOWING ALMOST NO INSTABILITY DEVELOPING INTO UPPER MI ON SAT...NOT EXPECTING ANY SVR STORMS SAT. LATEST DAY2 OUTLOOK FROM SPC HAS ALSO SHIFTED MRGL RISK FARTHER S INTO CNTRL WI AS WELL. IF FOR SOME REASON CLOUDS BREAK ALLOWING A BUILDING OF INSTABILITY...THEN THERE COULD BE SOME SVR STORMS SINCE DEEP LAYER SHEAR IS FCST TO BE IN EXCESS OF 50KT. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 441 PM EDT FRI JUN 19 2015 A ZONAL PATTERN WILL ALLOW A SERIES OF SHORTWAVES TO MOVE THROUGH THE NRN CONUS. AS THE RIDGE BUILDS OVER THE SW CONUS TOWARD THE END OF THE WEEK...A TRANSITION TOWARD MORE NW FLOW IS EXPECTED. TEMPS WILL GENERALLY REMAIN AT OR SLIGHTLY BELOW NORMAL WITH THE MAIN FRONTAL BOUNDARY REMAINING TO THE SOUTH OF THE REGION. SAT NIGHT...THE MODELS HAVE TRENDED SLIGHTLY SLOWER WITH THE PROGRESSION OF THE SHORTWAVE TROUGH AND ASSOCIATED PCPN. EXPECT SCT/NMRS SHRA OVER THE EAST HALF DURING THE EVENING TO MOVE OUT OF MOST OF THE CWA BY LATE EVENING BUT MAY LINGER OVER THE EAST AFT 03Z/SUN. NAM FCST MUCPE VALUES IN THE 300-600 J/KG RANGE MAY SUPPORT SOME ISOLD TSRA. OTHERWISE...SOME DRIZZLE MAY DEVELOP INTO N CNTRL UPPER MI WITH LINGERING LOW LEVEL MOISTURE AND UPSLOPE NRLY FLOW DEVELOPING BEHIND THE SFC TROUGH. SUN...EXPECT WEAK SFC RIDGE TO BUILD INTO THE AREA WITH MAINLY LIGHT WINDS ALLOWING LAKE BREEZES TO DEVELOP. ALTHOUGH MLCAPE MLCAPE VALUES INTO THE 500-1000 J/KG RANGE MAY BE POSSIBLE...MID LEVEL CAPPING QVECTOR/DIV SUBSIDENCE OVER THE AREA WILL NOT BE FAVORABLE FOR SHRA/TSRA DEVELOPMENT. SUN NIGHT AND MONDAY...ANOTHER SHORTWAVE TROUGH WILL MOVE THROUGH THE NRN LAKES WITH A PERIOD OF MODERATE TO STRONG QVECTOR CONV. ALTHOUGH ONLY CHANCE POPS WERE MENTIONED FOR NOW...MODEL TRENDS TOWARD A STRONGER/SLOWER SHRTWV SUGGESTS POPS MAY INCREASE CLOSER TO THE SHRA/TSRA EVENT. TUE-FRI...THE PROGRESSIVE PATTERN WILL FAVOR ADDITIONAL SHORTWAVES MOVING INTO THE AREA. HOWEVER...THE TIMING/STRENGTH OF ANY OF THESE FEATURES IS MORE DIFFICULT TO DETERMINE. SO...MODELS CONSENSUS LOWER END CHANCE POPS PREVAIL THROUGH THE PERIOD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 113 PM EDT FRI JUN 19 2015 VFR CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW THRU TONIGHT AS DRY LOW-LEVEL AIR MASS ASSOCIATED WITH DEPARTING HIGH PRES LINGERS OVER THE AREA. APPROACHING DISTURBANCE COULD BRING A FEW -SHRA TO KCMX/KIWD LATE TONIGHT...BUT EXPECTATION IS FOR PCPN TO PASS BY TO THE N. INCREASING WINDS OVER NOCTURNAL INVERSION WILL RESULT IN MARGINAL LLWS AT KIWD/KCMX TONIGHT. ON SAT...AREA OF SHRA SHOULD SPREAD E INTO UPPER MI...AFFECTING KIWD/KCMX IN THE MORNING. POSSIBLE ARRIVAL OF HEAVIER PCPN BY LATE MORNING AT KIWD MAY DROP CONDITIONS TO MVFR. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 357 PM EDT FRI JUN 19 2015 TYPICAL SUMMERTIME CONDITIONS WITH GENERALLY LIGHT WINDS WILL DOMINATE ACROSS LAKE SUPERIOR THRU THIS FCST PERIOD. STRONGEST WINDS WILL PROBABLY OCCUR TONIGHT THRU SAT MORNING AHEAD OF AN APPROACHING DISTURBANCE. OVER THE E HALF OF THE LAKE WHICH IS FAVORED FOR STRONGEST WINDS IN THIS TYPE OF PATTERN...S WINDS WILL LIKELY GUST TO AROUND 20KT AT TIMES. THE HIGHEST OBS PLATFORMS WILL PROBABLY GUST TO AROUND 30KT. WITH ONLY WEAK HIGH PRES BUILDING INTO THE AREA BEHIND THE DISTURBANCE...LIGHTER WINDS WILL FOLLOW FOR THE LAST HALF THE WEEKEND. THESE LIGHT WINDS...UNDER 20KT...WILL LIKELY CONTINUE THRU THE FIRST HALF OF NEXT WEEK AS A WEAK SUMMERTIME PRES GRADIENT SHOULD PREVAIL. EXPECTED RAINFALL SAT SHOULD RESULT IN SOME FOG DEVELOPING ACROSS THE LAKE...AND THE FOG COULD BECOME LOCALLY DENSE. IF THE FOG DOES IN FACT DEVELOP...FOG PATCHES MAY LINGER INTO EARLY NEXT WEEK DUE TO A LACK OF STRONG ADVECTION OF DRIER AIR. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...JLB AVIATION...ROLFSON MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
358 PM EDT FRI JUN 19 2015 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 357 PM EDT FRI JUN 19 2015 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF OVER THE PACIFIC NW/SW CANADA...SUBTLE RIDGING OVER MT/WY INTO THE WRN DAKOTAS AND WEAK TROFFING INTO NEW ENGLAND. LOW-LEVEL JET OVER THE WRN HIGH PLAINS FUELED SHRA/TSRA ACROSS THE DAKOTAS EARLY TODAY. MUCH OF THAT PCPN HAS SINCE DISSIPATED...BUT REMNANTS ARE STRENGTHENING AGAIN OVER ERN SD. OTHER REMNANT SHRA ARE MOVING ACROSS NW MN/SRN SASKATCHEWAN AND JUST ACROSS THE BORDER INTO NRN ONTARIO. CLOSER TO HOME...SFC HIGH PRES OVER THE UPPER LAKES IS PROVIDING A PLEASANT MID JUN AFTN ACROSS THE AREA. AFTER ABUNDANT SUNSHINE EARLIER TODAY...CU BLOSSOMED OVER THE E...BUT THOSE CLOUDS ARE NOW DISSIPATING. SCT-BKN MOSTLY THIN HIGH CLOUDS ARE ALSO STREAMING INTO PARTS OF THE AREA. QUIET WEATHER WILL BEGIN THE SHORT TERM WITH LINGERING DRY AIR MASS ASSOCIATED WITH SFC HIGH PRES MOVING FROM THE UPPER GREAT LAKES THIS AFTN TO NEW ENGLAND BY SAT MORNING. LATER TONIGHT AND INTO SAT... ATTENTION TURNS TO A COMPLEX SERIES OF SHORTWAVES STREAKING ACROSS THE NRN CONUS/SRN CANADA. IT APPEARS THAT THERE IS A SUBTLE WAVE SUPPORTING THE SHRA ACTIVITY CURRENTLY IN NW MN/SRN SASKATCHEWAN. THIS WAVE MAY CONTINUE TO AID SHRA AND MAYBE SOME TSRA INTO NRN LAKE SUPERIOR/ADJACENT NRN ONTARIO TONIGHT. ON THE NOSE OF THE 850MB THETA-E RIDGE WITH LOW-LEVEL JET INCREASING DURING THE NIGHT...THIS ACTIVITY MAY TEND TO INCREASE SOME AS THE NIGHT PROGRESSES. THE UNCERTAINTY IS IN WHETHER THIS CONVECTION WILL BUILD S FAR ENOUGH TO IMPACT NW UPPER MI LATE TONIGHT. MUCH OF THE MODEL GUIDANCE SUGGESTS PCPN WILL STAY N OF THE AREA. GIVEN PROXIMITY OF LOW-LEVEL JET/THETA- E AXIS...WILL MAINTAIN A SCHC MENTION INTO FAR WRN UPPER MI LATE TONIGHT. FARTHER W...THERE IS A CONSISTENT SIGNAL IN ALL MODEL GUIDANCE THAT ANOTHER CLUSTER OF SHRA/TSRA WILL DEVELOP/EXPAND IN THE ERN DAKOTAS/MN TONIGHT AHEAD OF ANOTHER SHORTWAVE...ON THE NOSE OF A STRONGER PORTION OF THE STRENGTHENING LOW-LEVEL JET AND THE ON NRN EDGE OF STRONG INSTABILITY OVER THE PLAINS. THIS ACTIVITY SHOULD STILL BE W OF UPPER MI AT 12Z SAT. FCST ON SAT WILL HINGE SOMEWHAT ON WHAT DEVELOPS OUT OF THE CONVECTION TO THE W TONIGHT. IF A SFC LOW CONVECTIVELY SPINS UP AND MOVES ACROSS NRN WI...IT COULD SUPPORT A LARGE AREA OF SHRA AND SOME ISOLD EMBEDDED THUNDER SPREADING E ACROSS THE FCST AREA DURING THE DAY. IT`S NOT CLEAR IF THAT WILL OCCUR. IN ANY EVENT...SHORTWAVE MOVING THRU THE UPPER LAKES SHOULD SUPPORT A GOOD POTENTIAL OF SHRA SPREADING W TO E ACROSS THE AREA SAT. IN GENERAL...LIKELY POPS LOOK REASONABLE. SINCE THE GFS HAS PULLED BACK ON INSTABILITY TO BECOME SIMILAR TO THE NAM IN SHOWING ALMOST NO INSTABILITY DEVELOPING INTO UPPER MI ON SAT...NOT EXPECTING ANY SVR STORMS SAT. LATEST DAY2 OUTLOOK FROM SPC HAS ALSO SHIFTED MRGL RISK FARTHER S INTO CNTRL WI AS WELL. IF FOR SOME REASON CLOUDS BREAK ALLOWING A BUILDING OF INSTABILITY...THEN THERE COULD BE SOME SVR STORMS SINCE DEEP LAYER SHEAR IS FCST TO BE IN EXCESS OF 50KT. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 439 AM EDT FRI JUN 19 2015 MEDIUM RANGE MODEL GUIDANCE THROUGH EXTENDED FCST PD IN FAIRLY GOOD AGREEMENT SHOWING A PERSISTENT ZONAL FLOW ACROSS THE NRN CONUS TO THE N OF A SUBTROPICAL UPR RDG OVER THE SRN STATES. MAIN FCST CHALLENGES WL BE TIMING PCPN EVENTS ASSOCIATED WITH DISTURBANCES STREAMING W-E IN THIS FAST FLOW. SINCE THE VERY WARM AND HUMID AIR WL REMAIN TO THE S CLOSER TO THE RDG...EXPECT TEMPS TO AVERAGE AT OR BELOW NORMAL DURING THIS PERIOD. SATURDAY...00Z MODELS AND EVEN MANY OF YESTERDAYS 12Z RUNS APPEAR TO HAVE INITIAL SHORTWAVE AND ASSOC BEST WAA/ISENTROPIC LIFT MOVING ACROSS THE UPPER GREAT LAKES SAT MORNING INTO EARLY SAT AFTERNOON. MODELS THEN INDICATE A SECONDARY SHORTWAVE MOVING INTO THE AREA SAT EVENING. THIS SECONDARY SHORTWAVE SHOULD BE WHAT PROPELS COLD FRONT INTO AREA LATE SAT AFTERNOON/EVENING. DEEP LAYER SHEAR NEAR 50 KT WOULD SUPPORT ORGANIZED STORMS AND POSSIBLY SVR RISK IF SUFFICIENT INSTABILITY DEVELOPS...BUT MODELS REALLY SHOW INSTABILITY LACKING. ONLY THE NAM INDICATES 300-400 J/KG MLCAPE BY 00Z SUNDAY OVER THE CENTRAL U.P. AND ALSO...MODELS INDICATE STEEPEST MID-LVL LAPSE RATES OF 7C/KM OR GREATER STAYING WELL SE OF THE FCST AREA CLOSER TO ORIENTATION AND AXIS OF 8H JET MAX OVER LOWER MIDWEST AND LOWER GREAT LAKES. THIS SHOULD LIMIT ANY SVR RISK AND SEEMS REASONABLE THAT SPC KEEPS SLIGHT RISK FOR SVR SOUTH OF FCST ON DAY3 CONVECTIVE OUTLOOK. HIGH PWAT OF 1.5 INCHES MOVING OVR THE AREA LATE SAT AFTERNOON/SAT EVENING AHEAD OF THE COLD FRONT COULD STILL SUPPORT HEAVIER SHOWERS AND MAYBE SOME ISOLD TSRA. AFTER SAT EVENING SHOWERS...MODELS INDICATE Q-VECT DIV AND DRYING/SUBSIDENCE IN WAKE OF SECONDARY SHORTWAVE AND COLD FROPA WHICH SHOULD SUPPORT GENERALLY DRIER FCST OVERNIGHT SAT NIGHT. HEADING INTO SUN...A FEW OF THE MODELS STILL HINT AT THE POSSIBILITY OF SOME TRAILING SHORTWAVES EMBEDDED IN THE WNW FLOW ALOFT. WHETHER THESE SHORTWAVES WILL HAVE AN IMPACT REMAINS IN QUESTION. PERHAPS THEY COULD AID IN GENERATING SOME LAKE BREEZE CONVERGENCE SHOWERS WITH DAYTIME HEATING UNDER LIGHT WIND FIELDS FROM WEAK SFC HIGH PRES MOVING INTO THE UPPER LAKES. AT THIS TIME WILL RETAIN SCHC POPS OVER THE INTERIOR CNTRL AND E FOR THIS POSSIBILITY. SUN NIGHT AND MONDAY...MODELS ADVERTISE YET ANOTHER WNW FLOW SHORTWAVE MOVING ACROSS THE UPPER GREAT LAKES WITH INCREASING DEEP LAYER Q-VECT AND MOISTENING. THIS WILL WARRANT ANOTHER INCREASE IN POPS FOR SHRA AND ISOLD TSRA SUN NIGHT INTO EARLY MONDAY. DRYING BEHIND THE SHORTWAVE SHOULD ALLOW FOR DRIER CONDITIONS THROUGH MUCH OF DAY ON MONDAY. THE PROGRESSIVE FLOW/ZONAL FLOW REGIME NEXT WEEK WILL MAKE IT INCREASINGLY DIFFICULT FOR FORECAST MODELS TO DETERMINE TIMING/STRENGTH/TRACK OF SHORTWAVES. AT THIS POINT...THERE ARE NO INDICATIONS FOR A WIDESPREAD/SIGNIFICANT PCPN EVENT IN THE MON THRU THU TIME FRAME. WHEN PCPN DOES OCCUR IN UPPER MI...COVERAGE WILL LIKELY BE ISOLD TO SCT. FOR NOW...WILL CONTINUE TO UTILIZE A SIMPLE CONSENSUS APPROACH OF MODELS GUIDANCE TO CONSTRUCT FCST. RESULT IS SCHC TO LOW CHC POPS ON MOST DAYS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 113 PM EDT FRI JUN 19 2015 VFR CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW THRU TONIGHT AS DRY LOW-LEVEL AIR MASS ASSOCIATED WITH DEPARTING HIGH PRES LINGERS OVER THE AREA. APPROACHING DISTURBANCE COULD BRING A FEW -SHRA TO KCMX/KIWD LATE TONIGHT...BUT EXPECTATION IS FOR PCPN TO PASS BY TO THE N. INCREASING WINDS OVER NOCTURNAL INVERSION WILL RESULT IN MARGINAL LLWS AT KIWD/KCMX TONIGHT. ON SAT...AREA OF SHRA SHOULD SPREAD E INTO UPPER MI...AFFECTING KIWD/KCMX IN THE MORNING. POSSIBLE ARRIVAL OF HEAVIER PCPN BY LATE MORNING AT KIWD MAY DROP CONDITIONS TO MVFR. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 357 PM EDT FRI JUN 19 2015 TYPICAL SUMMERTIME CONDITIONS WITH GENERALLY LIGHT WINDS WILL DOMINATE ACROSS LAKE SUPERIOR THRU THIS FCST PERIOD. STRONGEST WINDS WILL PROBABLY OCCUR TONIGHT THRU SAT MORNING AHEAD OF AN APPROACHING DISTURBANCE. OVER THE E HALF OF THE LAKE WHICH IS FAVORED FOR STRONGEST WINDS IN THIS TYPE OF PATTERN...S WINDS WILL LIKELY GUST TO AROUND 20KT AT TIMES. THE HIGHEST OBS PLATFORMS WILL PROBABLY GUST TO AROUND 30KT. WITH ONLY WEAK HIGH PRES BUILDING INTO THE AREA BEHIND THE DISTURBANCE...LIGHTER WINDS WILL FOLLOW FOR THE LAST HALF THE WEEKEND. THESE LIGHT WINDS...UNDER 20KT...WILL LIKELY CONTINUE THRU THE FIRST HALF OF NEXT WEEK AS A WEAK SUMMERTIME PRES GRADIENT SHOULD PREVAIL. EXPECTED RAINFALL SAT SHOULD RESULT IN SOME FOG DEVELOPING ACROSS THE LAKE...AND THE FOG COULD BECOME LOCALLY DENSE. IF THE FOG DOES IN FACT DEVELOP...FOG PATCHES MAY LINGER INTO EARLY NEXT WEEK DUE TO A LACK OF STRONG ADVECTION OF DRIER AIR. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...VOSS AVIATION...ROLFSON MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
633 PM CDT SAT JUN 20 2015 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 359 PM CDT SAT JUN 20 2015 WE REMAIN WITHIN A BELT OF RATHER HEALTHY WESTERLIES TODAY...THOUGH WATER VAPOR IMAGERY SHOWS WE ARE IN A ZONE OF SUBSIDENCE AND DRYING IN THE WAKE OF THE WAVE THAT PUSHED THE SHOWERS AND THUNDERSTORMS ACROSS THE REGION THIS MORNING. AT THE SFC...A TROUGH WITH A WIND SHIFT OVER TO THE NW HAD PUSHED TO ABOUT I-35 AS OF 230 PM. SPC MESO- ANALYSIS SHOWS 500-1500 J/KG OF MLCAPE ACROSS MOST OF THE AREA. HOWEVER...VIEW OUT THE WINDOW AND ON VISIBLE SATELLITE SHOWS THE CU FIELD ASSOCIATED WITH THIS INSTABILITY HAS A RATHER STABLE LOOK TO IT...SO NOT ANTICIPATING MUCH IN THE WAY OF PRECIP THIS AFTERNOON. SOME OF THE HI-RES CAMS /ESPECIALLY THE HRRR/ CONTINUE TO DEVELOP SOME ISO/SCT SHOWERS ALONG/AHEAD OF THE TROUGH FROM EC MN INTO WC MN...SO HAVE CONTINUED MENTION OF 20/30 POPS THIS AFTERNOON IN OUR EAST TO ACCOUNT FOR THAT. NEXT AREA TO WATCH FOR PRECIP THIS EVENING IS WRN MN. IR IMAGERY SHOWS A SHORT WAVE WORKING ACROSS NW SODAK. STARTING TO SEE STORMS BUBBLE UP FROM NW SODAK INTO NC NODAK BENEATH A PLUME OF STEEP MID- LEVEL LAPSE RATES. THE HRRR HAS PICKED UP ON THIS BIT OF FORCING...SHOWING A BROKEN LINE OF THUNDERSTORMS MOVING ACROSS THE DAKOTAS THE REST OF THE AFTERNOON AND MAKING A RUN FOR WEST CENTRAL MN BETWEEN 7PM AND 10PM. AS THESE STORMS RUN TOWARD MN...THE RAP SHOWS MUCAPE WANING...SO THINK THESE WILL RUN OUT OF STEAM BEFORE GETTING INTO MN...THOUGH WE MAY NEED TO GET SOME LOW PROBS FOR -SHRA INTO OUR WEST THIS EVENING. NEXT FEATURE OF INTEREST IS A STRONG SHORTWAVE EVIDENT ON WATER VAPOR IMAGERY THAT BETWEEN 7 AM AND 3 PM HAS GONE FROM OFF THE OREGON COAST TO WRN MT. DETERMINISTIC MODELS AND CAMS ARE IN GOOD AGREEMENT ON THIS WAVE KICKING OFF ANOTHER MCS OVER THE BLACK HILLS TONIGHT THAT WILL DIVE SE TOWARD OMAHA. AS IT DOES SO...ITS OUTFLOW BOUNDARY WILL BECOME A WARM FRONT THAT WILL BEGIN LIFTING NORTH ACROSS NEBRASKA TOWARD SW MN SUNDAY AFTERNOON. NAM/GFS SHOW A BAND OF ENHANCED INSTABILITY /1000-1500 J/KG OF MLCAPE/ DEVELOPING DURING THE AFTERNOON MORE OR LESS ALONG THE UPPER MN RIVER VALLEY. SEEING SOME INDICATIONS IN BOTH CAMS AND DETERMINISTIC MODELS OF SOME ISO/SCT TYPE CONVECTION DEVELOPING SUNDAY AFTERNOON WITHIN THIS INSTABILITY AXIS...SO HAVE LEFT SOME 20 POPS IN THERE TO ACCOUNT FOR THAT...THOUGH EXPECT IT TO BE MAINLY DRY FOR SUNDAY. FOR THE FOG THREAT TONIGHT...THINK NAM IS OVERDONE WITH THE AMOUNT OF LOW LEVEL MOISTURE IT HAS AND IS THEREFORE OVERDOING ITS FOG POTENTIAL IN WRN WI. LIKE THE IDEA OF THE RAP/GFS WITH FOG THREAT BEING PRIMARILY UP NE MN INTO NW WI. FINALLY...DID BOOST HIGHS FOR SUNDAY A FEW DEGREES ACROSS THE AREA. NAM/GFS SHOW US MIXING UP TO 800 MB...AND MIXING DOWN FROM THIS LEVEL YIELDED POTENTIAL HIGHS IN THE MID/UPPER 80S...SO MIXED THAT IN WITH OUR GOING FORECAST TO GET MOST FOLKS UP INTO THE LOW/MID 80S FOR HIGHS SUNDAY. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 359 PM CDT SAT JUN 20 2015 CONCERNS IN THE LONG TERM ARE CENTERED AROUND SEVERE WEATHER CHANCES SUNDAY NIGHT AND MONDAY AS A DEEPENING SHORT WAVE PASSES ACROSS THE FA. THIS RESULTS IN STRENGTHENING SURFACE LOW PRESSURE OVER SOUTH DAKOTA SUNDAY NIGHT ALONG WITH A WARM FRONT LIFTING NORTHEAST INTO SOUTHERN MINNESOTA AND WISCONSIN LATE IN THE NIGHT. MODEL CONSENSUS INDICATES THE NOSE OF THE LOW LEVEL JET EXCEEDS 50 KNOTS INTO SOUTH CENTRAL AND SOUTHEAST MINNESOTA MONDAY MORNING ACCOMPANIED BY PW VALUES IN EXCESS OF 2 INCHES...ONCE AGAIN ABOVE THE TOP OF KMPX SOUNDING CLIMATOLOGY. THE LOW AND WARM FRONT SHOULD PUSH RATHER QUICKLY ACROSS THE FA DURING THE DAY ON MONDAY WITH SEVERE WEATHER CHANCES LESSENING IN THE AFTERNOON. THE SETUP SUNDAY NIGHT AND EARLY MONDAY SHOULD YIELD A COMPLEX OF STORMS PUSHING ACROSS SOUTHERN MN AND ADJOINING AREAS OF WI. PROFILE DATA INDICATES A STRONG WARM LAYER DEVELOPING IN THE LOW LEVELS DURING THE NIGHT WITH VIRTUALLY ALL OF THE CAPE (1500 J/KG) BEING ABOVE 850 MB. HENCE...DUE TO THE STRONGLY VEERING WIND PROFILE CONFIDENCE FOR HAIL IS HIGHER THAN WIND EARLY ON IN THIS EVENT. IN ADDITION...THE 925-850MB FN VECTOR DIVERGENCE ALSO RUNS ALONG THE I-90 CORRIDOR LEADING TO HIGHER CONFIDENCE ON WHERE THE HEAVIEST RAIN MAY FALL. AT THIS POINT...CAMS THAT REACH OUT TO MONDAY MORNING ARE SHOWING A COMPLEX OF STORMS PASSING ALONG THE MN/IA BORDER. THEREFORE...COLLABORATION TODAY WAS TO BREAK POPS INTO 3 HOUR GROUPS AND DRIVE THUNDERSTORMS ACROSS OUR FAR SOUTHERN FA LATE SUNDAY NIGHT AND EARLY MONDAY. IN THE WAKE OF THIS FEATURE...MONDAY NIGHT AND TUESDAY ARE DRY AS HIGH PRESSURE SLIDES BY. A SURFACE FRONTAL BOUNDARY WILL BE STRENGTHENING ACROSS THE CENTRAL PLAINS INTO THE LOWER GREAT LAKES FOR WEDNESDAY AND THURSDAY WITH THE HIGHEST CHANCES FOR PRECIPITATION TO OUR SOUTH WITH SMALL CHANCES EXTENDING ACROSS PORTIONS OF OUR FA. CONFIDENCE IS NOT HIGH ON THE PRECIPITATION CHANCES FOR THESE PERIODS. THE STRONG WESTERLY UPPER AIR PATTERN IS STILL FORECAST TO BUCKLE LATE IN THE WEEK AND WEEKEND AS RIDGING DEVELOPS ACROSS IN THE WESTERN CONUS WITH A PRETTY DEEP TROUGH IN THE EAST. THIS TRANSITION PERIOD (FRIDAY AND SATURDAY) WILL OFFER THE NEXT PERIOD OF HIGH CHANCE POPS ACROSS THE FA. TEMPERATURES WILL BE CLOSE TO SEASONAL VALUES THROUGH THURSDAY WITH A SMALL DOWNWARD TREND ON HIGH TEMPERATURES THROUGH THE UPCOMING WEEKEND. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 635 PM CDT SAT JUN 20 2015 HIGH CONFIDENCE IN VFR...WITH THE EXCEPTION OF MVFR OR POSSIBLY IFR VSBY IN FOG OVER WC WI AROUND SUNRISE. OTHERWISE...WINDS WILL BECOME MORE WEST SUNDAY MORNING. KMSP... HIGH CONFIDENCE IN VFR CONDS THRU THE TAF PERIOD WITH WINDS FROM THE NW TONIGHT...MORE WEST/SW SUNDAY. /OUTLOOK FOR KMSP/ MON...VFR. CHC MVFR WITH TSRA/SHRA. WIND S 5-10 KT BCMG NW 10KTS. TUE...VFR. WINDS NW TO W AT 5 KT. WED...VFR. CHC OF TSRA. WINDS E-SE 5 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...MPG LONG TERM...RAH AVIATION...JLT
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
359 PM CDT SAT JUN 20 2015 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 359 PM CDT SAT JUN 20 2015 WE REMAIN WITHIN A BELT OF RATHER HEALTHY WESTERLIES TODAY...THOUGH WATER VAPOR IMAGERY SHOWS WE ARE IN A ZONE OF SUBSIDENCE AND DRYING IN THE WAKE OF THE WAVE THAT PUSHED THE SHOWERS AND THUNDERSTORMS ACROSS THE REGION THIS MORNING. AT THE SFC...A TROUGH WITH A WIND SHIFT OVER TO THE NW HAD PUSHED TO ABOUT I-35 AS OF 230 PM. SPC MESO- ANALYSIS SHOWS 500-1500 J/KG OF MLCAPE ACROSS MOST OF THE AREA. HOWEVER...VIEW OUT THE WINDOW AND ON VISIBLE SATELLITE SHOWS THE CU FIELD ASSOCIATED WITH THIS INSTABILITY HAS A RATHER STABLE LOOK TO IT...SO NOT ANTICIPATING MUCH IN THE WAY OF PRECIP THIS AFTERNOON. SOME OF THE HI-RES CAMS /ESPECIALLY THE HRRR/ CONTINUE TO DEVELOP SOME ISO/SCT SHOWERS ALONG/AHEAD OF THE TROUGH FROM EC MN INTO WC MN...SO HAVE CONTINUED MENTION OF 20/30 POPS THIS AFTERNOON IN OUR EAST TO ACCOUNT FOR THAT. NEXT AREA TO WATCH FOR PRECIP THIS EVENING IS WRN MN. IR IMAGERY SHOWS A SHORT WAVE WORKING ACROSS NW SODAK. STARTING TO SEE STORMS BUBBLE UP FROM NW SODAK INTO NC NODAK BENEATH A PLUME OF STEEP MID- LEVEL LAPSE RATES. THE HRRR HAS PICKED UP ON THIS BIT OF FORCING...SHOWING A BROKEN LINE OF THUNDERSTORMS MOVING ACROSS THE DAKOTAS THE REST OF THE AFTERNOON AND MAKING A RUN FOR WEST CENTRAL MN BETWEEN 7PM AND 10PM. AS THESE STORMS RUN TOWARD MN...THE RAP SHOWS MUCAPE WANING...SO THINK THESE WILL RUN OUT OF STEAM BEFORE GETTING INTO MN...THOUGH WE MAY NEED TO GET SOME LOW PROBS FOR -SHRA INTO OUR WEST THIS EVENING. NEXT FEATURE OF INTEREST IS A STRONG SHORTWAVE EVIDENT ON WATER VAPOR IMAGERY THAT BETWEEN 7 AM AND 3 PM HAS GONE FROM OFF THE OREGON COAST TO WRN MT. DETERMINISTIC MODELS AND CAMS ARE IN GOOD AGREEMENT ON THIS WAVE KICKING OFF ANOTHER MCS OVER THE BLACK HILLS TONIGHT THAT WILL DIVE SE TOWARD OMAHA. AS IT DOES SO...ITS OUTFLOW BOUNDARY WILL BECOME A WARM FRONT THAT WILL BEGIN LIFTING NORTH ACROSS NEBRASKA TOWARD SW MN SUNDAY AFTERNOON. NAM/GFS SHOW A BAND OF ENHANCED INSTABILITY /1000-1500 J/KG OF MLCAPE/ DEVELOPING DURING THE AFTERNOON MORE OR LESS ALONG THE UPPER MN RIVER VALLEY. SEEING SOME INDICATIONS IN BOTH CAMS AND DETERMINISTIC MODELS OF SOME ISO/SCT TYPE CONVECTION DEVELOPING SUNDAY AFTERNOON WITHIN THIS INSTABILITY AXIS...SO HAVE LEFT SOME 20 POPS IN THERE TO ACCOUNT FOR THAT...THOUGH EXPECT IT TO BE MAINLY DRY FOR SUNDAY. FOR THE FOG THREAT TONIGHT...THINK NAM IS OVERDONE WITH THE AMOUNT OF LOW LEVEL MOISTURE IT HAS AND IS THEREFORE OVERDOING ITS FOG POTENTIAL IN WRN WI. LIKE THE IDEA OF THE RAP/GFS WITH FOG THREAT BEING PRIMARILY UP NE MN INTO NW WI. FINALLY...DID BOOST HIGHS FOR SUNDAY A FEW DEGREES ACROSS THE AREA. NAM/GFS SHOW US MIXING UP TO 800 MB...AND MIXING DOWN FROM THIS LEVEL YIELDED POTENTIAL HIGHS IN THE MID/UPPER 80S...SO MIXED THAT IN WITH OUR GOING FORECAST TO GET MOST FOLKS UP INTO THE LOW/MID 80S FOR HIGHS SUNDAY. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 359 PM CDT SAT JUN 20 2015 CONCERNS IN THE LONG TERM ARE CENTERED AROUND SEVERE WEATHER CHANCES SUNDAY NIGHT AND MONDAY AS A DEEPENING SHORT WAVE PASSES ACROSS THE FA. THIS RESULTS IN STRENGTHENING SURFACE LOW PRESSURE OVER SOUTH DAKOTA SUNDAY NIGHT ALONG WITH A WARM FRONT LIFTING NORTHEAST INTO SOUTHERN MINNESOTA AND WISCONSIN LATE IN THE NIGHT. MODEL CONSENSUS INDICATES THE NOSE OF THE LOW LEVEL JET EXCEEDS 50 KNOTS INTO SOUTH CENTRAL AND SOUTHEAST MINNESOTA MONDAY MORNING ACCOMPANIED BY PW VALUES IN EXCESS OF 2 INCHES...ONCE AGAIN ABOVE THE TOP OF KMPX SOUNDING CLIMATOLOGY. THE LOW AND WARM FRONT SHOULD PUSH RATHER QUICKLY ACROSS THE FA DURING THE DAY ON MONDAY WITH SEVERE WEATHER CHANCES LESSENING IN THE AFTERNOON. THE SETUP SUNDAY NIGHT AND EARLY MONDAY SHOULD YIELD A COMPLEX OF STORMS PUSHING ACROSS SOUTHERN MN AND ADJOINING AREAS OF WI. PROFILE DATA INDICATES A STRONG WARM LAYER DEVELOPING IN THE LOW LEVELS DURING THE NIGHT WITH VIRTUALLY ALL OF THE CAPE (1500 J/KG) BEING ABOVE 850 MB. HENCE...DUE TO THE STRONGLY VEERING WIND PROFILE CONFIDENCE FOR HAIL IS HIGHER THAN WIND EARLY ON IN THIS EVENT. IN ADDITION...THE 925-850MB FN VECTOR DIVERGENCE ALSO RUNS ALONG THE I-90 CORRIDOR LEADING TO HIGHER CONFIDENCE ON WHERE THE HEAVIEST RAIN MAY FALL. AT THIS POINT...CAMS THAT REACH OUT TO MONDAY MORNING ARE SHOWING A COMPLEX OF STORMS PASSING ALONG THE MN/IA BORDER. THEREFORE...COLLABORATION TODAY WAS TO BREAK POPS INTO 3 HOUR GROUPS AND DRIVE THUNDERSTORMS ACROSS OUR FAR SOUTHERN FA LATE SUNDAY NIGHT AND EARLY MONDAY. IN THE WAKE OF THIS FEATURE...MONDAY NIGHT AND TUESDAY ARE DRY AS HIGH PRESSURE SLIDES BY. A SURFACE FRONTAL BOUNDARY WILL BE STRENGTHENING ACROSS THE CENTRAL PLAINS INTO THE LOWER GREAT LAKES FOR WEDNESDAY AND THURSDAY WITH THE HIGHEST CHANCES FOR PRECIPITATION TO OUR SOUTH WITH SMALL CHANCES EXTENDING ACROSS PORTIONS OF OUR FA. CONFIDENCE IS NOT HIGH ON THE PRECIPITATION CHANCES FOR THESE PERIODS. THE STRONG WESTERLY UPPER AIR PATTERN IS STILL FORECAST TO BUCKLE LATE IN THE WEEK AND WEEKEND AS RIDGING DEVELOPS ACROSS IN THE WESTERN CONUS WITH A PRETTY DEEP TROUGH IN THE EAST. THIS TRANSITION PERIOD (FRIDAY AND SATURDAY) WILL OFFER THE NEXT PERIOD OF HIGH CHANCE POPS ACROSS THE FA. TEMPERATURES WILL BE CLOSE TO SEASONAL VALUES THROUGH THURSDAY WITH A SMALL DOWNWARD TREND ON HIGH TEMPERATURES THROUGH THE UPCOMING WEEKEND. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 106 PM CDT SAT JUN 20 2015 MVFR CIGS QUICKLY LIFTING THIS AFTERNOON AS THE BOUNDARY LAYER CONTINUES TO DEEPEN. EXPECT MAINLY VFR CONDS BY 21Z AREA WIDE...WITH CIGS STAYING THAT WAY THE REST OF THE PERIOD. WE MAY SEE SOME ISOLATED SHRA/TSRA DEVELOP THIS AFTERNOON IN WRN WI...BUT COVERAGE IS EXPECTED TO BE SPARSE ENOUGH TO LEAVE ANY SORT OF PRECIP MENTION OUT OF WI TAFS. TONIGHT...SOME CONCERN BASED ON NAM SOUNDINGS THAT FOG COULD BE AN ISSUE FOR EAU...BUT THINK NAM IS OVERDONE ON ITS LOW LEVEL MOISTURE WHEN COMPARED TO WHAT THE RAP/GFS SHOW...SO LIMITED ANY VIS RESTRICTIONS THERE TO JUST AN MVFR BR. FOG POTENTIAL LOOKS MUCH BETTER FARTHER NORTH ACROSS NW WI AND NE MN. KMSP...WILL SEE OCCASIONAL MVFR CIGS FOR THE FIRST HOUR...BUT AFTER THAT...ITS VFR WITH W/NW WINDS THE REST OF THE TAF. NO WEATHER CONCERNS AT MSP UNTIL LATE SUNDAY NIGHT INTO MONDAY MORNING. /OUTLOOK FOR KMSP/ MON...VFR. CHC MVFR WITH TSRA/SHRA. WIND S 5-10 KT BCMG NW 10KTS. TUE...VFR. WINDS N AT 5 KT. WED...VFR. WINDS VRB AT 5KT. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...MPG LONG TERM...RAH AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1142 PM CDT FRI JUN 19 2015 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 345 PM CDT FRI JUN 19 2015 EVERYTHING STILL LOOKS ON TRACK TO SEE A BOWING MCS MOVE ACROSS THE AREA TONIGHT. WHERE THERE IS MORE UNCERTAINTY IS WHAT HAPPENS OUT AHEAD OF THIS SYSTEM IN SRLY FLOW AND WAA. THIS HAS RESULTED IN AN IMPRESSIVE LINE OF THUNDERSTORMS OVER CENTRAL SODAK. NONE OF THE GUIDANCE REALLY PICKED UP ON THIS ALL THAT WELL...BUT BY 00Z...THE HRRR AND A COUPLE OF THE HOPWRF MEMBERS SHOW SOME ACTIVITY IN WRN MN. BASED ON WHERE ACTIVITY AND INSTABILITY ARE AT THE MOMENT... THINK THIS IS TOO FAR EAST TO SEE ANYTHING THIS EVENING AND THINK ANY OF THIS SORT OF ACTIVITY WOULD STAY TO OUR WEST/SW...BACK WHERE THE INSTABILITY RESIDES. FOR TONIGHT...THERE IS STRONG MODEL AGREEMENT IN THE CAMS ON AN BOWING MCS DEVELOPING OVER SODAK. THIS MAKES PLENTY OF SENSE WHEN LOOKING AT THE DETERMINISTIC MODELS...WHICH CONTINUE TO SHOW A SRLY LLJ INCREASING TO AROUND 50 KTS BENEATH A WRLY 60 KT MID-LEVEL JET. THE WAVE THAT WILL BE RESPONSIBLE FOR THIS SYSTEM IS CURRENTLY MOVING ACROSS MT. STORMS SHOULD BEGIN TO BUILD IN ERN MONTANA BETWEEN 3 AND 5 PM AND CONGEAL INTO A FORWARD PROPAGATING MCS BETWEEN 7 AND 10 PM ALONG THE WRN NORTH/SOUTH DAKOTA BORDER. STORM MOTION OFF THE HI-RES MODELS IS NEARLY 50 MPH...WHICH MATCHES UP WELL WITH THE FORWARD PROPAGATING CORFIDI VECTORS OFF THE NAM. THIS FORWARD MOTION IS WHAT WILL DRIVE THE HIGH WIND THREAT THIS EVENING...BUT WILL ALSO DIMINISH PRECIPITATION TOTALS THAT WE SEE. THOUGH PWATS UP NEAR 1.5 INCHES FAVOR A HEAVY RAIN THREAT...THE FORWARD MOTION OF THE SYSTEM WILL REALLY CUT DOWN ON RAINFALL TOTALS AND THINK ANY FLASH FLOOD THREAT WE HAVE TONIGHT WOULD COME WITHIN THE COMMA HEAD OF A MATURE MCS IF ONE WERE TO DEVELOP. AS FOR TIMING THIS SYSTEM IN THE GRIDS...GIVEN THE SPEED ITS MOVING...FOLLOWED THE FASTER CAMS. THIS RESULTED IN SOMETHING CLOSE TO WHAT THE HRRR HAS...SWITCHING TO THE HIRES-ARW ONCE WE GET PAST THE 15 HOURS OF THE HRRR. ONE CONCERN FOR SEEING CONVECTION EARLIER IS SOME OF THE CAMS ARE ALSO SHOWING A LEAD BAND OF WAA ELEVATED CONVECTION DEVELOPING DIRECTLY AHEAD OF THE BOW. IF THIS WERE TO OCCUR IT WOULD LEAD TO TWO THINGS...AN INCREASE IN THE SEVERE THREAT...INCLUDING THE POSSIBILITY OF SOME BRIEF SPIN UPS. BESIDE THAT...THIS WOULD HELP WITH THE HEAVY RAIN TREAT AS THE WAA BAND WOULD RESULT IN A LEAD BAND OF HEAVY RAIN OUT AHEAD OF THE SQUALL LINE...AND THIS WOULD ALSO BE THE SAME REGION WHERE COMMA HEAD PRECIP WOULD BE MOST LIKELY. FOR SATURDAY...THIS LINE WILL BE FALLING APART DURING THE MORNING OVER WRN WI. BY THE AFTERNOON...NW WINDS WILL BE DEVELOPING WITH DRIER AIR WORKING IN. LOOKING MORE AND MORE LIKELY THAT WE WILL NOT SEE ANY ADDITIONAL PRECIP IN THE MPX CWA THE REST OF SATURDAY...WITH AFTERNOON CONVECTION DEVELOPING FROM THE QUAD CITIES UP TOWARD GREEN BAY. LEFT SOME CHANCE POPS IN DURING THE AFTERNOON FOR CONTINUITY... BUT IF HI-RES MODELS CONTINUE TO SHOW A LACK OF STORMS SATURDAY AFTERNOON IN THE MPX AREA...WE COULD PROBABLY JUST GO DRY FOR SATURDAY. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 345 PM CDT FRI JUN 19 2015 THE FIRST HALF OF THE LONGER TERM WILL FEATURE PERIODIC PRECIPITATION EVENTS AS A SERIES OF SHORT WAVES PUSH THROUGH IN THE STRONG BELT OF WESTERLY ACROSS THE NORTHERN TIER OF STATES. THE POLAR FRONT WILL MEANDER BACK AND FORTH ACROSS OUR AREA THROUGH EARLY NEXT WEEK RESULTING IN SMALL CHANCES FOR SHOWERS AND THUNDERSTORMS. THE BEST AGREEMENT FOR PRECIPITATION EARLY ON BETWEEN THE GFS AND ECMWF IS SUNDAY NIGHT INTO EARLY MONDAY AND THEN AGAIN FROM LATE TUESDAY INTO WEDNESDAY. THE FRONTAL BOUNDARY THEN BECOMES MORE STATIONARY BY MID WEEK FROM NEBRASKA THROUGH NORTHERN ILLINOIS. IT/S THE MID WEEK PERIOD THAT IS TROUBLESOME FOR HEAVY RAIN WITH THUNDERSTORM COMPLEXES EXPECTED TO MOVE ALONG AND NORTH OF THIS BOUNDARY. A CHECK OF THE CIPS ANALOGS SHOWS THE CHANCES FOR SIGNIFICANT RAIN AMOUNTS HIGHEST FROM NORTHERN IA THROUGH NORTHERN IL...WHICH IS QUITE SIMILAR TO THE FORECAST FROM THE 12Z ECMWF. HENCE...GRIDDED PRECIPITATION CHANCES ARE HIGHEST ACROSS SOUTHERN MN THROUGH THE MID WEEK PERIOD. THE LATER HALF OF NEXT WEEK INTO THE WEEKEND WILL FEATURE A BUILDING RIDGE IN THE WEST WITH A DEEP TROUGH DEVELOPING ACROSS THE WESTERN GREAT LAKES. THIS WILL LEAD TO MORE SHOWER CHANCES...ESPECIALLY FROM FRIDAY ONWARD AS WELL AS SPREAD OUT MORE EVENLY ACROSS THE FA. LOW/HIGH TEMPERATURES THROUGH NEXT FRIDAY (FIRST WEEK OF SUMMER) ARE FORECAST TO BE QUITE CLOSE TO SEASONAL VALUES. LOOKING AT THIS COMING SATURDAY NIGHT...THERE IS GOOD AGREEMENT IN THE DETERMINISTIC MODELS THAT A COOL FRONT WILL BE PUSHING EAST OF OUR WI COUNTIES IN THE EVENING. HENCE...ONLY A FEW SHOWERS ARE EXPECTED IN THE EVENING ACROSS WEST CENTRAL WI WITH DRY WEATHER ELSEWHERE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1135 PM CDT FRI JUN 19 2015 SHORT TERM MODELS CONTINUE TO ADVERTISE A LINE OF THUNDERSTORMS FORMING ACROSS SD AND MOVING EAST RAPIDLY ACROSS WESTERN AND INTO EASTERN MN BETWEEN 7-13Z. CURRENT REGIONAL RADAR DOES SUPPORT THIS SCENARIO AS TWO AREAS OF TSRA ARE DEVELOPING/CONTINUING TO FORM OVER CENTRAL SD...NE INTO SE ND. BASED ON THE SPEED OF THIS LINE...WIND GUSTS WILL ACCOMPANY THIS TSRA LINE...BUT CONFIDENCE IS LOW ON HOW WIDESPREAD 30-40 KT WINDS PROPAGATE EASTWARD. BEST SCENARIO IS TO HOLD ONTO A 2-3 HR PERIOD OF SHRA AND EMBEDDED TSRA STARTING AT KAXN/KRWF ARND 7-8Z...AND INTO KSTC BY 9-10Z. ALTHOUGH CIGS WILL LOWER IN THE VCNTY OF THE TSRA...THE BIG FACTOR IS THE VSBY WHICH IS LIKELY TO HOLD IN THE MVFR RANGE FOR 1-2 HRS...WITH SMALL PERIODS OF IFR/LIFR VSBY IN HEAVY RAINFALL. WILL HOLD ONTO THE 3SM TSRA...BUT CONFIDENCE IS HIGH FOR A SHORT PERIOD OF IFR VSBY OR LOWER. BEHIND THE MAIN COMPLEX OF SHRA/TSRA...MVFR/IFR CIGS WILL LIKELY DEVELOP SATURDAY MORNING...WITH A SLOW RISE DURING THE AFTN BEFORE VFR SATURDAY EVENING. KMSP... CONFIDENCE IS HIGH THAT A LINE OF TSRA/SHRA WILL MOVE ACROSS THE AIRFIELD BETWEEN 11-13Z. VCTS IS POSSIBLE AS EARLY AS 9Z WITH AN ISOLD TSRA AHEAD OF THIS LINE. THERE IS ALSO HIGH CONFIDENCE OF A PERIOD OF IFR/MVFR VSBY IN HEAVIER RAINFALL. THERE IS ALSO A POSSIBILITY OF WIND GUSTS ALONG THIS LINE OF 40 KTS. BUT CONFIDENCE IS TOO LOW FOR TIMING AND SPECIFICS. MVFR CIGS ARE ALSO LIKELY BEHIND THE MAIN AREA OF SHRA/TSRA...AND WILL LIKELY LAST UNTIL THE EARLY AFTN...WITH VFR CONDS SATURDAY EVENING. WINDS WILL BE GENERALLY S/SE AHEAD OF THIS TSRA COMPLEX...WITH WINDS SHIFTING TO THE WEST/NW BY THE AFTN. /OUTLOOK FOR KMSP/ SUN...VFR WITH TSRA/SHRA POSSIBLE SUNDAY NIGHT. WINDS W AT 5-10 KT. MON...VFR. WIND NW AT 5-10 KT. TUE...VFR. CHC TSRA/SHRA. WINDS E AT 5-10 KT. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...MPG LONG TERM...RAH AVIATION...JLT
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
638 PM CDT FRI JUN 19 2015 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 345 PM CDT FRI JUN 19 2015 EVERYTHING STILL LOOKS ON TRACK TO SEE A BOWING MCS MOVE ACROSS THE AREA TONIGHT. WHERE THERE IS MORE UNCERTAINTY IS WHAT HAPPENS OUT AHEAD OF THIS SYSTEM IN SRLY FLOW AND WAA. THIS HAS RESULTED IN AN IMPRESSIVE LINE OF THUNDERSTORMS OVER CENTRAL SODAK. NONE OF THE GUIDANCE REALLY PICKED UP ON THIS ALL THAT WELL...BUT BY 00Z...THE HRRR AND A COUPLE OF THE HOPWRF MEMBERS SHOW SOME ACTIVITY IN WRN MN. BASED ON WHERE ACTIVITY AND INSTABILITY ARE AT THE MOMENT... THINK THIS IS TOO FAR EAST TO SEE ANYTHING THIS EVENING AND THINK ANY OF THIS SORT OF ACTIVITY WOULD STAY TO OUR WEST/SW...BACK WHERE THE INSTABILITY RESIDES. FOR TONIGHT...THERE IS STRONG MODEL AGREEMENT IN THE CAMS ON AN BOWING MCS DEVELOPING OVER SODAK. THIS MAKES PLENTY OF SENSE WHEN LOOKING AT THE DETERMINISTIC MODELS...WHICH CONTINUE TO SHOW A SRLY LLJ INCREASING TO AROUND 50 KTS BENEATH A WRLY 60 KT MID-LEVEL JET. THE WAVE THAT WILL BE RESPONSIBLE FOR THIS SYSTEM IS CURRENTLY MOVING ACROSS MT. STORMS SHOULD BEGIN TO BUILD IN ERN MONTANA BETWEEN 3 AND 5 PM AND CONGEAL INTO A FORWARD PROPAGATING MCS BETWEEN 7 AND 10 PM ALONG THE WRN NORTH/SOUTH DAKOTA BORDER. STORM MOTION OFF THE HI-RES MODELS IS NEARLY 50 MPH...WHICH MATCHES UP WELL WITH THE FORWARD PROPAGATING CORFIDI VECTORS OFF THE NAM. THIS FORWARD MOTION IS WHAT WILL DRIVE THE HIGH WIND THREAT THIS EVENING...BUT WILL ALSO DIMINISH PRECIPITATION TOTALS THAT WE SEE. THOUGH PWATS UP NEAR 1.5 INCHES FAVOR A HEAVY RAIN THREAT...THE FORWARD MOTION OF THE SYSTEM WILL REALLY CUT DOWN ON RAINFALL TOTALS AND THINK ANY FLASH FLOOD THREAT WE HAVE TONIGHT WOULD COME WITHIN THE COMMA HEAD OF A MATURE MCS IF ONE WERE TO DEVELOP. AS FOR TIMING THIS SYSTEM IN THE GRIDS...GIVEN THE SPEED ITS MOVING...FOLLOWED THE FASTER CAMS. THIS RESULTED IN SOMETHING CLOSE TO WHAT THE HRRR HAS...SWITCHING TO THE HIRES-ARW ONCE WE GET PAST THE 15 HOURS OF THE HRRR. ONE CONCERN FOR SEEING CONVECTION EARLIER IS SOME OF THE CAMS ARE ALSO SHOWING A LEAD BAND OF WAA ELEVATED CONVECTION DEVELOPING DIRECTLY AHEAD OF THE BOW. IF THIS WERE TO OCCUR IT WOULD LEAD TO TWO THINGS...AN INCREASE IN THE SEVERE THREAT...INCLUDING THE POSSIBILITY OF SOME BRIEF SPIN UPS. BESIDE THAT...THIS WOULD HELP WITH THE HEAVY RAIN TREAT AS THE WAA BAND WOULD RESULT IN A LEAD BAND OF HEAVY RAIN OUT AHEAD OF THE SQUALL LINE...AND THIS WOULD ALSO BE THE SAME REGION WHERE COMMA HEAD PRECIP WOULD BE MOST LIKELY. FOR SATURDAY...THIS LINE WILL BE FALLING APART DURING THE MORNING OVER WRN WI. BY THE AFTERNOON...NW WINDS WILL BE DEVELOPING WITH DRIER AIR WORKING IN. LOOKING MORE AND MORE LIKELY THAT WE WILL NOT SEE ANY ADDITIONAL PRECIP IN THE MPX CWA THE REST OF SATURDAY...WITH AFTERNOON CONVECTION DEVELOPING FROM THE QUAD CITIES UP TOWARD GREEN BAY. LEFT SOME CHANCE POPS IN DURING THE AFTERNOON FOR CONTINUITY... BUT IF HI-RES MODELS CONTINUE TO SHOW A LACK OF STORMS SATURDAY AFTERNOON IN THE MPX AREA...WE COULD PROBABLY JUST GO DRY FOR SATURDAY. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 345 PM CDT FRI JUN 19 2015 THE FIRST HALF OF THE LONGER TERM WILL FEATURE PERIODIC PRECIPITATION EVENTS AS A SERIES OF SHORT WAVES PUSH THROUGH IN THE STRONG BELT OF WESTERLY ACROSS THE NORTHERN TIER OF STATES. THE POLAR FRONT WILL MEANDER BACK AND FORTH ACROSS OUR AREA THROUGH EARLY NEXT WEEK RESULTING IN SMALL CHANCES FOR SHOWERS AND THUNDERSTORMS. THE BEST AGREEMENT FOR PRECIPITATION EARLY ON BETWEEN THE GFS AND ECMWF IS SUNDAY NIGHT INTO EARLY MONDAY AND THEN AGAIN FROM LATE TUESDAY INTO WEDNESDAY. THE FRONTAL BOUNDARY THEN BECOMES MORE STATIONARY BY MID WEEK FROM NEBRASKA THROUGH NORTHERN ILLINOIS. IT/S THE MID WEEK PERIOD THAT IS TROUBLESOME FOR HEAVY RAIN WITH THUNDERSTORM COMPLEXES EXPECTED TO MOVE ALONG AND NORTH OF THIS BOUNDARY. A CHECK OF THE CIPS ANALOGS SHOWS THE CHANCES FOR SIGNIFICANT RAIN AMOUNTS HIGHEST FROM NORTHERN IA THROUGH NORTHERN IL...WHICH IS QUITE SIMILAR TO THE FORECAST FROM THE 12Z ECMWF. HENCE...GRIDDED PRECIPITATION CHANCES ARE HIGHEST ACROSS SOUTHERN MN THROUGH THE MID WEEK PERIOD. THE LATER HALF OF NEXT WEEK INTO THE WEEKEND WILL FEATURE A BUILDING RIDGE IN THE WEST WITH A DEEP TROUGH DEVELOPING ACROSS THE WESTERN GREAT LAKES. THIS WILL LEAD TO MORE SHOWER CHANCES...ESPECIALLY FROM FRIDAY ONWARD AS WELL AS SPREAD OUT MORE EVENLY ACROSS THE FA. LOW/HIGH TEMPERATURES THROUGH NEXT FRIDAY (FIRST WEEK OF SUMMER) ARE FORECAST TO BE QUITE CLOSE TO SEASONAL VALUES. LOOKING AT THIS COMING SATURDAY NIGHT...THERE IS GOOD AGREEMENT IN THE DETERMINISTIC MODELS THAT A COOL FRONT WILL BE PUSHING EAST OF OUR WI COUNTIES IN THE EVENING. HENCE...ONLY A FEW SHOWERS ARE EXPECTED IN THE EVENING ACROSS WEST CENTRAL WI WITH DRY WEATHER ELSEWHERE. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING) ISSUED AT 630 PM CDT FRI JUN 19 2015 A COMPLEX OF THUNDERSTORMS IN EASTERN SD WILL BE THE MAIN CONCERN IN THE FIRST 6 HRS WITH ISOLD/SCT CONVECTION AFFECTING KRWF/KAXN. CONFIDENCE IS LOW ON AFFECTING THE AIRPORT GROUNDS. SO KEPT VCSH OR NIL AT THIS TIME. INSTABILITY IS LACKING IN EASTERN MN THIS EVENING...SO IF ANY ACTIVITY MOVES INTO THIS AREA...ANY PRECIPITATION WILL BE ISOLD. CIGS WILL BE VFR...EXCEPT IN THE VCNTY OF THE TSRA. AFT MIDNIGHT...A LINE OF TSRA REMAINS ON TRACK TO AFFECT KAXN/KRWF WITH A PERIOD OF HEAVY RAINFALL AND GUSTY WINDS BETWEEN 6-9Z. SOME OF THE WIND GUSTS COULD APPROACH SVR LIMITS. CONFIDENCE IS MEDIUM ON THIS LINE MOVING THRU WESTERN MN AFTER MIDNIGHT. FURTHER EAST...THIS LINE WILL LIKELY WEAKEN SOME BUT STILL HAVE THE POTENTIAL OF PRODUCING HEAVY RAINFALL WITH LOW VSBY. MVFR CIGS WILL LIKELY OCCUR AFTER THE MAIN AREA OF SHRA/TSRA SATURDAY MORNING...WITH MVFR CIGS LIKELY CONTINUING THRU THE EARLY AFTN. WINDS WILL BE SOUTH/SE TONIGHT...BECOMING WEST/NW BY SATURDAY MORNING. KMSP... AN ISOLD SHRA IS POSSIBLE BETWEEN 3-6Z...BUT CONFIDENCE IS VERY LOW. THE MAIN LINE OF SHRA/TSRA WILL OCCUR AFT 9Z...WITH HIGHER CONFIDENCE ARND 10-12Z. MVFR CIGS ARE POSSIBLE AS WINDS SHIFT TO THE WEST/NW DURING THE MORNING...AND LINGER DURING THE EARLY AFTN. /OUTLOOK FOR KMSP/ SUN...VFR WITH TSRA/SHRA POSSIBLE OVERNIGHT. WINDS W AT 5-10 KT. MON...VFR. WIND NW AT 5-10 KT. TUE...VFR. CHC TSRA/SHRA. WINDS E AT 5-10 KT. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...MPG LONG TERM...RAH AVIATION...JLT
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
345 PM CDT FRI JUN 19 2015 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 345 PM CDT FRI JUN 19 2015 EVERYTHING STILL LOOKS ON TRACK TO SEE A BOWING MCS MOVE ACROSS THE AREA TONIGHT. WHERE THERE IS MORE UNCERTAINTY IS WHAT HAPPENS OUT AHEAD OF THIS SYSTEM IN SRLY FLOW AND WAA. THIS HAS RESULTED IN AN IMPRESSIVE LINE OF THUNDERSTORMS OVER CENTRAL SODAK. NONE OF THE GUIDANCE REALLY PICKED UP ON THIS ALL THAT WELL...BUT BY 00Z...THE HRRR AND A COUPLE OF THE HOPWRF MEMBERS SHOW SOME ACTIVITY IN WRN MN. BASED ON WHERE ACTIVITY AND INSTABILITY ARE AT THE MOMENT... THINK THIS IS TOO FAR EAST TO SEE ANYTHING THIS EVENING AND THINK ANY OF THIS SORT OF ACTIVITY WOULD STAY TO OUR WEST/SW...BACK WHERE THE INSTABILITY RESIDES. FOR TONIGHT...THERE IS STRONG MODEL AGREEMENT IN THE CAMS ON AN BOWING MCS DEVELOPING OVER SODAK. THIS MAKES PLENTY OF SENSE WHEN LOOKING AT THE DETERMINISTIC MODELS...WHICH CONTINUE TO SHOW A SRLY LLJ INCREASING TO AROUND 50 KTS BENEATH A WRLY 60 KT MID-LEVEL JET. THE WAVE THAT WILL BE RESPONSIBLE FOR THIS SYSTEM IS CURRENTLY MOVING ACROSS MT. STORMS SHOULD BEGIN TO BUILD IN ERN MONTANA BETWEEN 3 AND 5 PM AND CONGEAL INTO A FORWARD PROPAGATING MCS BETWEEN 7 AND 10 PM ALONG THE WRN NORTH/SOUTH DAKOTA BORDER. STORM MOTION OFF THE HI-RES MODELS IS NEARLY 50 MPH...WHICH MATCHES UP WELL WITH THE FORWARD PROPAGATING CORFIDI VECTORS OFF THE NAM. THIS FORWARD MOTION IS WHAT WILL DRIVE THE HIGH WIND THREAT THIS EVENING...BUT WILL ALSO DIMINISH PRECIPITATION TOTALS THAT WE SEE. THOUGH PWATS UP NEAR 1.5 INCHES FAVOR A HEAVY RAIN THREAT...THE FORWARD MOTION OF THE SYSTEM WILL REALLY CUT DOWN ON RAINFALL TOTALS AND THINK ANY FLASH FLOOD THREAT WE HAVE TONIGHT WOULD COME WITHIN THE COMMA HEAD OF A MATURE MCS IF ONE WERE TO DEVELOP. AS FOR TIMING THIS SYSTEM IN THE GRIDS...GIVEN THE SPEED ITS MOVING...FOLLOWED THE FASTER CAMS. THIS RESULTED IN SOMETHING CLOSE TO WHAT THE HRRR HAS...SWITCHING TO THE HIRES-ARW ONCE WE GET PAST THE 15 HOURS OF THE HRRR. ONE CONCERN FOR SEEING CONVECTION EARLIER IS SOME OF THE CAMS ARE ALSO SHOWING A LEAD BAND OF WAA ELEVATED CONVECTION DEVELOPING DIRECTLY AHEAD OF THE BOW. IF THIS WERE TO OCCUR IT WOULD LEAD TO TWO THINGS...AN INCREASE IN THE SEVERE THREAT...INCLUDING THE POSSIBILITY OF SOME BRIEF SPIN UPS. BESIDE THAT...THIS WOULD HELP WITH THE HEAVY RAIN TREAT AS THE WAA BAND WOULD RESULT IN A LEAD BAND OF HEAVY RAIN OUT AHEAD OF THE SQUALL LINE...AND THIS WOULD ALSO BE THE SAME REGION WHERE COMMA HEAD PRECIP WOULD BE MOST LIKELY. FOR SATURDAY...THIS LINE WILL BE FALLING APART DURING THE MORNING OVER WRN WI. BY THE AFTERNOON...NW WINDS WILL BE DEVELOPING WITH DRIER AIR WORKING IN. LOOKING MORE AND MORE LIKELY THAT WE WILL NOT SEE ANY ADDITIONAL PRECIP IN THE MPX CWA THE REST OF SATURDAY...WITH AFTERNOON CONVECTION DEVELOPING FROM THE QUAD CITIES UP TOWARD GREEN BAY. LEFT SOME CHANCE POPS IN DURING THE AFTERNOON FOR CONTINUITY... BUT IF HI-RES MODELS CONTINUE TO SHOW A LACK OF STORMS SATURDAY AFTERNOON IN THE MPX AREA...WE COULD PROBABLY JUST GO DRY FOR SATURDAY. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 345 PM CDT FRI JUN 19 2015 THE FIRST HALF OF THE LONGER TERM WILL FEATURE PERIODIC PRECIPITATION EVENTS AS A SERIES OF SHORT WAVES PUSH THROUGH IN THE STRONG BELT OF WESTERLY ACROSS THE NORTHERN TIER OF STATES. THE POLAR FRONT WILL MEANDER BACK AND FORTH ACROSS OUR AREA THROUGH EARLY NEXT WEEK RESULTING IN SMALL CHANCES FOR SHOWERS AND THUNDERSTORMS. THE BEST AGREEMENT FOR PRECIPITATION EARLY ON BETWEEN THE GFS AND ECMWF IS SUNDAY NIGHT INTO EARLY MONDAY AND THEN AGAIN FROM LATE TUESDAY INTO WEDNESDAY. THE FRONTAL BOUNDARY THEN BECOMES MORE STATIONARY BY MID WEEK FROM NEBRASKA THROUGH NORTHERN ILLINOIS. IT/S THE MID WEEK PERIOD THAT IS TROUBLESOME FOR HEAVY RAIN WITH THUNDERSTORM COMPLEXES EXPECTED TO MOVE ALONG AND NORTH OF THIS BOUNDARY. A CHECK OF THE CIPS ANALOGS SHOWS THE CHANCES FOR SIGNIFICANT RAIN AMOUNTS HIGHEST FROM NORTHERN IA THROUGH NORTHERN IL...WHICH IS QUITE SIMILAR TO THE FORECAST FROM THE 12Z ECMWF. HENCE...GRIDDED PRECIPITATION CHANCES ARE HIGHEST ACROSS SOUTHERN MN THROUGH THE MID WEEK PERIOD. THE LATER HALF OF NEXT WEEK INTO THE WEEKEND WILL FEATURE A BUILDING RIDGE IN THE WEST WITH A DEEP TROUGH DEVELOPING ACROSS THE WESTERN GREAT LAKES. THIS WILL LEAD TO MORE SHOWER CHANCES...ESPECIALLY FROM FRIDAY ONWARD AS WELL AS SPREAD OUT MORE EVENLY ACROSS THE FA. LOW/HIGH TEMPERATURES THROUGH NEXT FRIDAY (FIRST WEEK OF SUMMER) ARE FORECAST TO BE QUITE CLOSE TO SEASONAL VALUES. LOOKING AT THIS COMING SATURDAY NIGHT...THERE IS GOOD AGREEMENT IN THE DETERMINISTIC MODELS THAT A COOL FRONT WILL BE PUSHING EAST OF OUR WI COUNTIES IN THE EVENING. HENCE...ONLY A FEW SHOWERS ARE EXPECTED IN THE EVENING ACROSS WEST CENTRAL WI WITH DRY WEATHER ELSEWHERE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 115 PM CDT FRI JUN 19 2015 CONFIDENCE IS HIGH IN A SQUALL LINE COMING OUT OF SODAK AND WORKING ACROSS MN THIS EVENING. GIVEN THE BOWING NATURE OF THE LINE EXPECTED...FOLLOWED THE FASTER SOLUTIONS FOR TIMING THE LINE THROUGH...WHICH IN THIS CASE WAS CLOSE TO THE ARW. WHERE UNCERTAINTY EXISTS IS IF WE WILL SEE SOME ELEVATED STORMS IN THE WAA OUT AHEAD OF THE LINE...WHICH IS WHAT THE HRRR AND SOME OF THE HOPWRF MEMBERS SHOW OCCURRING. IF THIS OCCURS...THIS WOULD RESULT IN EARLIER TSRA ACTIVITY IN CENTRAL MN. ALSO FOLLOWED THE IDEA OF THE LAV/NAM WITH SOME IFR/MVFR STRATUS DEVELOPING IN THE WAKE OF THIS SYSTEM...THOUGH LESS CONFIDENCE ON HOW WIDESPREAD AND LONG LASTING THAT WILL BE. KMSP...CONFIDENCE IS HIGH IN TSRA IMPACTING MSP BETWEEN 10 AND 12Z SAT MORNING. BY THEN...THE SEVERE PUNCH WILL LIKELY BE LIMITED...BUT SOME GUSTY WEST WINDS WILL STILL BE POSSIBLE AS THE LINE COMES THROUGH. HAVE MVFR CIGS IN THE WAKE OF THE SYSTEM RIGHT NOW FOR SATURDAY MORNING...BUT MODELS COULD BE OVERDONE WITH HOW WIDESPREAD THOSE CIGS ARE. BY SAT AFTERNOON...WINDS WILL BE OUT OF THE NW...BRINING IN SLIGHTLY DRIER AIR AND KEEPING ANY AFTN CONVECTION WELL EAST OF THE TWIN CITIES. /OUTLOOK FOR KMSP/ SUN...VFR WITH TSRA/SHRA POSSIBLE OVERNIGHT. WINDS W AT 5-10 KT. MON...VFR. WIND NW AT 5-10 KT. TUE...VFR. CHC TSRA/SHRA. WINDS E AT 5-10 KT. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...MPG LONG TERM...RAH AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
115 PM CDT FRI JUN 19 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 407 AM CDT FRI JUN 19 2015 EARLY MORNING WATER VAPOR IMAGERY TOGETHER WITH GFS 500MB HEIGHTS AND WINDS SHOWED AROUND 50KTS OF ZONAL FLOW FROM THE PACIFIC NORTHWEST TOWARD THE GREAT LAKES. BOOKENDING THIS ZONAL FLOW WERE TWO UPPER LEVEL LOWS...ONE OFF THE BRITISH COLUMBIA COAST...AND THE OTHER OVER NORTHERN QUEBEC. THE UPSTREAM LOW IS THE ONE OF MOST INTEREST...SINCE SHORTWAVE ENERGY ROTATING AROUND THIS LOW WILL BREAK OFF INTO THE ZONAL FLOW...CROSS THE ROCKIES...AND BE THE TRIGGER FOR HIGH PLAINS CONVECTION THIS AFTERNOON...WHICH WILL CARRY OVER TO MN/WI FRIDAY NIGHT AS DISCUSSED IN MORE DETAIL IN THE LONG TERM SECTION. MEANWHILE...A NOCTURNAL THUNDERSTORM COMPLEX ONGOING ACROSS THE BADLANDS OF SOUTH DAKOTA WILL FALL APART BY THE TIME IT REACHES THE TWIN CITIES. THE 19.05 HRRR DEPICTS THIS...AND THE CAUSE IS A MORE STABLE AIRMASS...AS WELL AS SLIGHT LARGE SCALE SUBSIDENCE. AS A RESULT EXPECT NOTHING MORE THAN CONVECTIVE DEBRIS TODAY. SOUTHERLY WINDS WILL BRING TEMPERATURES NEAR 80 ACROSS MN...AND MID 70S IN WESTERN WI. A FEW AFTERNOON SHOWERS ARE POSSIBLE ACROSS FAR WESTERN MN WITH THE WARM AIR ADVECTION AHEAD OF A DEVELOPING SURFACE TROUGH. CONTINUED WITH 30 PERCENT CHANCE FOR PRECIP...BUT TRIMMED DOWN THE AREA CLOSER TO THE HIRES MODEL CONSENSUS. 925-850MB MOISTURE TRANSPORT BLOSSOMS ACROSS EASTERN SD AND WESTERN MN BY 06Z SATURDAY ON THE NOSE OF A 50 KT LOW LEVEL JET. THIS SHOULD HELP FUEL THE DIURNAL CONVECTION THAT IS EXPECTED TO HAVE DEVELOPED OVER THE WESTERN/CENTRAL DAKOTAS...AND ACCELERATE IT EASTWARD ACROSS THE FORECAST AREA OVERNIGHT AND SATURDAY MORNING. STILL LOOKS TO BE A POTENTIAL WIND- MAKER...ALTHOUGH IT SHOULD BE LOSING SOME STEAM AS IT WORKS EASTWARD INTO A MORE STABLE ENVIRONMENT. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 407 AM CDT FRI JUN 19 2015 AT DAYBREAK SATURDAY...THE AFOREMENTIONED LINE OF THUNDERSTORMS SHOULD BE ONGOING ACROSS WESTERN/CENTRAL MN. HI-RES MODELS INDICATE A QUASI-BOW STRUCTURE WILL DEVELOP...ALTHOUGH IT IS FORECAST TO DEINTENSIFY BY THE TIME IT REACHES THE I-35 CORRIDOR. BY 18Z SATURDAY...THE ACTIVITY SHOULD BE LIMITED TO SCATTERED SHOWERS OVER WEST CENTRAL WI DOWN INTO SOUTH CENTRAL MN. DEPENDING ON HOW MUCH CLEARING AND SUBSEQUENT DESTABILIZATION WE CAN TAP INTO...SHOULD SEE REDEVELOPMENT SATURDAY AFTERNOON ALONG THE COLD FRONT. SATURDAY AFTERNOON CONVECTION WILL HAVE A DECENT CHANCE OF BEING STRONG AGAIN. HOWEVER...IT IS CURRENTLY EXPECTED THAT THE NOCTURNAL CONVECTION WILL HELP PUSH THE BOUNDARY OUT OF THE MAJORITY OF THE FORECAST AREA...THUS REDUCING THE THREAT FOR SEVERE STORMS IN OUR FORECAST AREA. IF THE OVERNIGHT COMPLEX DOES NOT END UP BEING AS STRONG AS EXPECTED...SATURDAY AFTERNOON WILL LIKELY HAVE A HIGHER RISK FOR STRONG/SEVERE STORMS FROM CENTRAL/SOUTH CENTRAL MN EAST ACROSS WEST CENTRAL WI. ON SUNDAY INTO THE BEGINNING OF THE UPCOMING WEEK...THE FRONT WOBBLES IN AND OUT OF THE FORECAST AREA...AS EMBEDDED SHORTWAVES TRAVERSE THE FAST WESTERLY MID LEVEL FLOW REGIME. THERE WILL BE A THREAT FOR HEAVY RAINFALL ALONG THE BOUNDARY...ALTHOUGH THAT THREAT IS LOOKING MORE LIKELY TO LIE SOUTH OF THE AREA. TEMPERATURES THROUGH THE PERIOD LOOK TO BE NEAR NORMAL OVERALL...WITH A TEMPORARY UPTICK TO HIGHS IN THE 80S OVER THE WEEKEND. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 115 PM CDT FRI JUN 19 2015 CONFIDENCE IS HIGH IN A SQUALL LINE COMING OUT OF SODAK AND WORKING ACROSS MN THIS EVENING. GIVEN THE BOWING NATURE OF THE LINE EXPECTED...FOLLOWED THE FASTER SOLUTIONS FOR TIMING THE LINE THROUGH...WHICH IN THIS CASE WAS CLOSE TO THE ARW. WHERE UNCERTAINTY EXISTS IS IF WE WILL SEE SOME ELEVATED STORMS IN THE WAA OUT AHEAD OF THE LINE...WHICH IS WHAT THE HRRR AND SOME OF THE HOPWRF MEMBERS SHOW OCCURRING. IF THIS OCCURS...THIS WOULD RESULT IN EARLIER TSRA ACTIVITY IN CENTRAL MN. ALSO FOLLOWED THE IDEA OF THE LAV/NAM WITH SOME IFR/MVFR STRATUS DEVELOPING IN THE WAKE OF THIS SYSTEM...THOUGH LESS CONFIDENCE ON HOW WIDESPREAD AND LONG LASTING THAT WILL BE. KMSP...CONFIDENCE IS HIGH IN TSRA IMPACTING MSP BETWEEN 10 AND 12Z SAT MORNING. BY THEN...THE SEVERE PUNCH WILL LIKELY BE LIMITED...BUT SOME GUSTY WEST WINDS WILL STILL BE POSSIBLE AS THE LINE COMES THROUGH. HAVE MVFR CIGS IN THE WAKE OF THE SYSTEM RIGHT NOW FOR SATURDAY MORNING...BUT MODELS COULD BE OVERDONE WITH HOW WIDESPREAD THOSE CIGS ARE. BY SAT AFTERNOON...WINDS WILL BE OUT OF THE NW...BRINING IN SLIGHTLY DRIER AIR AND KEEPING ANY AFTN CONVECTION WELL EAST OF THE TWIN CITIES. /OUTLOOK FOR KMSP/ SUN...VFR WITH TSRA/SHRA POSSIBLE OVERNIGHT. WINDS W AT 5-10 KT. MON...VFR. WIND NW AT 5-10 KT. TUE...VFR. CHC TSRA/SHRA. WINDS E AT 5-10 KT. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...JRB/LS LONG TERM...LS AVIATION...MPG
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1250 PM CDT FRI JUN 19 2015 .UPDATE... ISSUED AT 1250 PM CDT FRI JUN 19 2015 UPDATED FOR THE NEW 18Z AVIATION DISCUSSION BELOW. UPDATE ISSUED AT 939 AM CDT FRI JUN 19 2015 BRIEF UPDATE TO WINDS AND SKY COVER...MAINLY TO INCREASE WIND SPEEDS ACROSS PARTS OF NORTHEAST MINNESOTA WHERE BREEZY WINDS ARE EXPECTED TO DEVELOP THIS AFTERNOON. EXPECTING WINDS OF 10 TO 15 MPH WITH GUSTS TO 25 MPH IN THE BRAINERD TO GRAND RAPIDS REGION...WITH A FEW GUSTS TO 30 MPH POSSIBLE. LATEST RAP MODEL SOUNDING FOR BRD DEPICTING MIXING TO NEARLY 750 MB...RESULTING IN 25-30 KT WINDS POSSIBLY MIXING DOWN. UPDATE ISSUED AT 653 AM CDT FRI JUN 19 2015 RAIN IN NW MN HAS SHOWN SOME EROSION ON THE LEADING EDGE AS IT APPROACHES NE MN. HAVE SLOWED DOWN THE ONSET OF THE RAIN AS A RESULT. REST OF THE FORECAST ON TRACK. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 326 AM CDT FRI JUN 19 2015 HIGH PRESSURE WAS DRIFTING OVER THE FORECAST AREA AT 0730Z. A CANOPY OF CIRRUS WAS FLOATING OVER THE TOP OF THE HIGH BEING DRIVE BY SHORT WAVE ENERGY DRIFTING OVER THE DAKOTAS. A FEW SHOWERS WERE OCCURRING AS A RESULT OVER EASTERN ND. LATEST SHORT TERM HIRES MODELS ARE IN AGREEMENT WITH THE OTHER MODELS IN BRINGING THIS RAIN INTO THE WESTERN EDGE OF THE AREA JUST AFTER 12Z. THERE IS SOME EROSION OCCURRING WITH IS SHOWER ACTIVITY IS IT MOVES CLOSER TO THE HIGH AND ITS DRIER AIRMASS. HAVE THE HIGHEST POPS ALONG THE INTERNATIONAL BORDER AS THIS SHORT WAVE ENERGY MOVES ALONG THE BORDER. THIS IS ALSO IN AN AREA OF FGEN THAT STICKS NEAR THE BORDER THROUGH 18Z. MAINTAIN THE HIGH POPS ALONG THE BORDER THROUGH THE AFTERNOON AS FGEN INCREASES IN THE IN THE 925MB LAYER. THIS FGEN SIGNAL THEN LIFTS N OF THE BORDER AFTER 00Z AND THUS LOWERED THE POPS. MODEL DIFFERENCES REVEAL THEMSELVES THIS EVENING IN REGARDS TO A THUNDERSTORM COMPLEX FORECAST TO AFFECT THE AREA. A SLOWER TREND HAS BEEN NOTED IN THE LATEST MODEL GUIDANCE AND HAVE SLOWED THE ONSET THE OF THE STORMS A BIT. THE MODELS HAVE ALSO COME INTO A BIT BETTER AGREEMENT THAN 24 HOURS AGO AND ARE POINTING TO THE THUNDERSTORM COMPLEX BEING FARTHER SOUTH. THIS IS CONFIRMED BY THE MODELS HAVING THE THE HIGHEST MUCAPE AXIS OVER SOUTHERN MN BY 12Z SATURDAY. BEST FGEN FORCING IS OVER CENTRAL AND SOUTHERN MN AND HAVE ALIGNED THE HIGHER POPS OVER THE SOUTHERN EDGE OF THE REGION. THERE WILL BE AN AREA OF THUNDERSTORMS MOVING ALONG THE CANADIAN BORDER TONIGHT AS WELL. THESE STORMS ARE IN RESPONSE TO A POTENT SHORT WAVE TROF DIVING SEWD FROM NE ND/SOUTH CENTRAL CANADA THEN OVER LAKE SUPERIOR BY 12Z SATURDAY. THERE WILL BE PERIODS OF MODERATE RAINFALL WITH PWATS APPROACHING 1.5 INCHES...BUT WILL REFRAIN FROM HEAVY RAIN WORDING ATTM. MODEL DIFFERENCES BECOME LARGER ON SATURDAY. THE QUASI ZONAL UPPER FLOW WILL BE ANCHORED OVER THE AREA. AS A RESULT...A PARADE OF SHORT WAVES WILL PLOW THROUGH THE FORECAST AREA ON SATURDAY. THIS WILL RESULT IN MORE THUNDERSTORMS AFFECTING THE ENTIRE REGION SATURDAY MORNING BEFORE DIMINISHING SOMEWHAT IN THE AFTERNOON. THE STRONGEST SHORT WAVE CRUISES THROUGH NORTHERN MN IN THE MORNING AND NW WI IN THE EARLY AFTERNOON BEFORE DEPARTING. HAVE HIGH POPS IN THE MORNING ACROSS THE AREA AND THEN THE HIGHEST POPS WILL BE OVER THE EASTERN EDGE OF THE FORECAST AREA IN THE AFTERNOON. PWATS DECREASE THROUGH THE DAY SATURDAY SO NO MENTION OF HEAVY RAIN. LAPSE RATES ARE MARGINAL FOR ANY SEVERE HAIL AND AM NOT ANTICIPATING ANY OF THE STORMS TO BE SEVERE ON SATURDAY. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 326 AM CDT FRI JUN 19 2015 A ZONAL FLOW ALOFT WILL KEEP THE WEATHER CONDITIONS ACTIVE THROUGH THE EXTENDED PERIOD WITH PERIODS OF SHOWERS AND STORMS. UPPER TROUGH AND ASSOCIATED SFC COLD FRONT WILL BE EXITING TO THE EAST SAT EVENING WITH WEAK HIGH PRESSURE BUILDING IN OVER THE UPPER MIDWEST. COULD SEE A FEW AFTERNOON SHOWERS AND WEAK STORMS ON SUNDAY...BUT THE MAIN PUSH OF PRECIPITATION WILL BE SEEN WITH THE NEXT INCOMING DISTURBANCE AFTER MIDNIGHT AND MONDAY MORNING. MODEST WAA AND A STRONG PUSH OF MOISTURE FROM THE SOUTH AHEAD OF THE FRONT WILL AID IN THE DEVELOPMENT OF SHOWERS AND STORMS INTO EARLY MONDAY AFTERNOON. ANOTHER BROAD AREA OF HIGH PRESSURE SETTLES IN OVER THE REGION MON NIGHT BEFORE THE NEXT SYSTEM TRACKS EWD ACROSS THE MID MS VALLEY REGION...WELL TO THE SOUTH OF THE NORTHLAND. THE NRN EDGE OF THIS SYSTEM WILL BRUSH THE SRN COUNTIES WITH ADDITIONAL SHOWERS AND STORMS LATE TUE INTO WED. HOWEVER...MOST OF THE AREA SHOULD REMAIN DRY. AN UPPER TROUGH RIDES IN FROM THE NW ON THURSDAY...BUT DOES NOT HAVE ENOUGH MOISTURE TO REALLY DO TOO MUCH. TEMPERATURES THROUGH THE WEEKEND AND MOST OF NEXT WEEK WILL REMAIN ON THE WARM SIDE WITH HIGHS IN THE MID TO UPPER 70S...AND OVERNIGHT LOWS IN THE 50S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1250 PM CDT FRI JUN 19 2015 THE VFR CONDITIONS ACROSS NE MINNESOTA AND NW WISCONSIN WILL LIKELY CONTINUE THROUGH THIS EVENING. GUSTY SOUTHERLY WINDS WILL DEVELOP BY LATE THIS AFTERNOON...BUT THEN WEAKEN NEAR SUNSET. THERE WILL BE INCREASING CHANCES OF -SHRA AND -TSRA LATE THIS EVENING...MAINLY OVER FAR NORTHERN MINNESOTA NEAR WHERE THERE WILL BE A STATIONARY FRONT. THE CHANCES OF SHOWERS AND STORMS WILL SPREAD TO THE REST OF THE REGION OVERNIGHT AS THAT FRONT BEGINS TO SAG SOUTH AND A STRONG LOW LEVEL JET STREAM DEVELOPS OVER THE REGION. THE LOW LEVEL JET WILL CAUSE PERIODS OF LLWS AT TERMINALS TONIGHT AND LINGERING INTO SATURDAY MORNING. THE THREAT OF OVERNIGHT THUNDER WILL BE GREATER FOR THE KINL/KHIB/KDLH AREAS. THE KBRD AND KHYR ARE MORE LIKELY TO BE AFFECTED BY JUST -RA...POSSIBLY GUSTY WINDS...FROM THE NORTHERN FRINGES OF STORM COMPLEX THAT WILL LIKELY HIT THE SOUTHERN HALF OF MINNESOTA AND ADJACENT AREAS OF WISCONSIN. THERE WILL LIKELY BE A TRANSITION FROM VFR TO IFR/MVFR CONDITIONS EARLY SATURDAY WITH LOWERING CIGS AND VSBY DUE TO RAINY AND MISTY CONDITIONS. THERE MAY BE ENOUGH IMPROVEMENT IN THE LATE MORNING TO RETURN TO MVFR/VFR CONDITIONS BY THE AFTERNOON. && .PRELIMINARY POINT TEMPS/POPS... DLH 72 59 75 55 / 10 60 70 20 INL 71 59 73 52 / 70 60 50 10 BRD 77 63 80 58 / 20 70 60 10 HYR 72 61 75 58 / 0 50 80 20 ASX 72 60 73 54 / 0 60 70 20 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. LS...NONE. && $$ UPDATE...GROCHOCINSKI SHORT TERM...GSF LONG TERM...TENTINGER AVIATION...GROCHOCINSKI
AREA FORECAST DISCUSSION
NWS DULUTH MN
939 AM CDT FRI JUN 19 2015 .UPDATE... ISSUED AT 939 AM CDT FRI JUN 19 2015 BRIEF UPDATE TO WINDS AND SKY COVER...MAINLY TO INCREASE WIND SPEEDS ACROSS PARTS OF NORTHEAST MINNESOTA WHERE BREEZY WINDS ARE EXPECTED TO DEVELOP THIS AFTERNOON. EXPECTING WINDS OF 10 TO 15 MPH WITH GUSTS TO 25 MPH IN THE BRAINERD TO GRAND RAPIDS REGION...WITH A FEW GUSTS TO 30 MPH POSSIBLE. LATEST RAP MODEL SOUNDING FOR BRD DEPICTING MIXING TO NEARLY 750 MB...RESULTING IN 25-30 KT WINDS POSSIBLY MIXING DOWN. UPDATE ISSUED AT 653 AM CDT FRI JUN 19 2015 RAIN IN NW MN HAS SHOWN SOME EROSION ON THE LEADING EDGE AS IT APPROACHES NE MN. HAVE SLOWED DOWN THE ONSET OF THE RAIN AS A RESULT. REST OF THE FORECAST ON TRACK. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 326 AM CDT FRI JUN 19 2015 HIGH PRESSURE WAS DRIFTING OVER THE FORECAST AREA AT 0730Z. A CANOPY OF CIRRUS WAS FLOATING OVER THE TOP OF THE HIGH BEING DRIVE BY SHORT WAVE ENERGY DRIFTING OVER THE DAKOTAS. A FEW SHOWERS WERE OCCURRING AS A RESULT OVER EASTERN ND. LATEST SHORT TERM HIRES MODELS ARE IN AGREEMENT WITH THE OTHER MODELS IN BRINGING THIS RAIN INTO THE WESTERN EDGE OF THE AREA JUST AFTER 12Z. THERE IS SOME EROSION OCCURRING WITH IS SHOWER ACTIVITY IS IT MOVES CLOSER TO THE HIGH AND ITS DRIER AIRMASS. HAVE THE HIGHEST POPS ALONG THE INTERNATIONAL BORDER AS THIS SHORT WAVE ENERGY MOVES ALONG THE BORDER. THIS IS ALSO IN AN AREA OF FGEN THAT STICKS NEAR THE BORDER THROUGH 18Z. MAINTAIN THE HIGH POPS ALONG THE BORDER THROUGH THE AFTERNOON AS FGEN INCREASES IN THE IN THE 925MB LAYER. THIS FGEN SIGNAL THEN LIFTS N OF THE BORDER AFTER 00Z AND THUS LOWERED THE POPS. MODEL DIFFERENCES REVEAL THEMSELVES THIS EVENING IN REGARDS TO A THUNDERSTORM COMPLEX FORECAST TO AFFECT THE AREA. A SLOWER TREND HAS BEEN NOTED IN THE LATEST MODEL GUIDANCE AND HAVE SLOWED THE ONSET THE OF THE STORMS A BIT. THE MODELS HAVE ALSO COME INTO A BIT BETTER AGREEMENT THAN 24 HOURS AGO AND ARE POINTING TO THE THUNDERSTORM COMPLEX BEING FARTHER SOUTH. THIS IS CONFIRMED BY THE MODELS HAVING THE THE HIGHEST MUCAPE AXIS OVER SOUTHERN MN BY 12Z SATURDAY. BEST FGEN FORCING IS OVER CENTRAL AND SOUTHERN MN AND HAVE ALIGNED THE HIGHER POPS OVER THE SOUTHERN EDGE OF THE REGION. THERE WILL BE AN AREA OF THUNDERSTORMS MOVING ALONG THE CANADIAN BORDER TONIGHT AS WELL. THESE STORMS ARE IN RESPONSE TO A POTENT SHORT WAVE TROF DIVING SEWD FROM NE ND/SOUTH CENTRAL CANADA THEN OVER LAKE SUPERIOR BY 12Z SATURDAY. THERE WILL BE PERIODS OF MODERATE RAINFALL WITH PWATS APPROACHING 1.5 INCHES...BUT WILL REFRAIN FROM HEAVY RAIN WORDING ATTM. MODEL DIFFERENCES BECOME LARGER ON SATURDAY. THE QUASI ZONAL UPPER FLOW WILL BE ANCHORED OVER THE AREA. AS A RESULT...A PARADE OF SHORT WAVES WILL PLOW THROUGH THE FORECAST AREA ON SATURDAY. THIS WILL RESULT IN MORE THUNDERSTORMS AFFECTING THE ENTIRE REGION SATURDAY MORNING BEFORE DIMINISHING SOMEWHAT IN THE AFTERNOON. THE STRONGEST SHORT WAVE CRUISES THROUGH NORTHERN MN IN THE MORNING AND NW WI IN THE EARLY AFTERNOON BEFORE DEPARTING. HAVE HIGH POPS IN THE MORNING ACROSS THE AREA AND THEN THE HIGHEST POPS WILL BE OVER THE EASTERN EDGE OF THE FORECAST AREA IN THE AFTERNOON. PWATS DECREASE THROUGH THE DAY SATURDAY SO NO MENTION OF HEAVY RAIN. LAPSE RATES ARE MARGINAL FOR ANY SEVERE HAIL AND AM NOT ANTICIPATING ANY OF THE STORMS TO BE SEVERE ON SATURDAY. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 326 AM CDT FRI JUN 19 2015 A ZONAL FLOW ALOFT WILL KEEP THE WEATHER CONDITIONS ACTIVE THROUGH THE EXTENDED PERIOD WITH PERIODS OF SHOWERS AND STORMS. UPPER TROUGH AND ASSOCIATED SFC COLD FRONT WILL BE EXITING TO THE EAST SAT EVENING WITH WEAK HIGH PRESSURE BUILDING IN OVER THE UPPER MIDWEST. COULD SEE A FEW AFTERNOON SHOWERS AND WEAK STORMS ON SUNDAY...BUT THE MAIN PUSH OF PRECIPITATION WILL BE SEEN WITH THE NEXT INCOMING DISTURBANCE AFTER MIDNIGHT AND MONDAY MORNING. MODEST WAA AND A STRONG PUSH OF MOISTURE FROM THE SOUTH AHEAD OF THE FRONT WILL AID IN THE DEVELOPMENT OF SHOWERS AND STORMS INTO EARLY MONDAY AFTERNOON. ANOTHER BROAD AREA OF HIGH PRESSURE SETTLES IN OVER THE REGION MON NIGHT BEFORE THE NEXT SYSTEM TRACKS EWD ACROSS THE MID MS VALLEY REGION...WELL TO THE SOUTH OF THE NORTHLAND. THE NRN EDGE OF THIS SYSTEM WILL BRUSH THE SRN COUNTIES WITH ADDITIONAL SHOWERS AND STORMS LATE TUE INTO WED. HOWEVER...MOST OF THE AREA SHOULD REMAIN DRY. AN UPPER TROUGH RIDES IN FROM THE NW ON THURSDAY...BUT DOES NOT HAVE ENOUGH MOISTURE TO REALLY DO TOO MUCH. TEMPERATURES THROUGH THE WEEKEND AND MOST OF NEXT WEEK WILL REMAIN ON THE WARM SIDE WITH HIGHS IN THE MID TO UPPER 70S...AND OVERNIGHT LOWS IN THE 50S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 633 AM CDT FRI JUN 19 2015 VFR CONDITIONS EXPECTED THIS MORNING AND THROUGH THE AFTERNOON WITH AN AREA OF WEAKENING CONVECTION OVER THE DAKOTAS MOVING INTO NRN MN BY THE LATE MORNING AND EARLY AFTERNOON. THIS PRECIPITATION WILL DISSIPATE THROUGH THE AFTERNOON WITH RE-DEVELOPMENT IN THE DAKOTAS LATER TODAY. THIS CONVECTION WILL MOVE EWD TONIGHT WITH SHOWERS AND STORMS SPREADING ACROSS THE NORTHLAND THROUGH SAT MORNING. COULD SEE IFR VSBYS IN THE HEAVIER SHOWERS/STORMS...WITH MVFR CIGS. SOUTH WINDS COULD BECOME GUSTY THIS AFTERNOON. && .PRELIMINARY POINT TEMPS/POPS... DLH 72 59 75 55 / 10 60 70 20 INL 71 59 73 52 / 70 60 50 10 BRD 77 63 80 58 / 20 70 60 10 HYR 72 61 75 58 / 0 50 80 20 ASX 72 60 73 54 / 0 60 70 20 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. LS...NONE. && $$ UPDATE...JJM SHORT TERM...GSF LONG TERM...TENTINGER AVIATION...TENTINGER
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
538 AM CDT FRI JUN 19 2015 .UPDATED FOR 12Z AVIATION DISCUSSION... ISSUED AT 529 AM CDT FRI JUN 19 2015 && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 407 AM CDT FRI JUN 19 2015 EARLY MORNING WATER VAPOR IMAGERY TOGETHER WITH GFS 500MB HEIGHTS AND WINDS SHOWED AROUND 50KTS OF ZONAL FLOW FROM THE PACIFIC NORTHWEST TOWARD THE GREAT LAKES. BOOKENDING THIS ZONAL FLOW WERE TWO UPPER LEVEL LOWS...ONE OFF THE BRITISH COLUMBIA COAST...AND THE OTHER OVER NORTHERN QUEBEC. THE UPSTREAM LOW IS THE ONE OF MOST INTEREST...SINCE SHORTWAVE ENERGY ROTATING AROUND THIS LOW WILL BREAK OFF INTO THE ZONAL FLOW...CROSS THE ROCKIES...AND BE THE TRIGGER FOR HIGH PLAINS CONVECTION THIS AFTERNOON...WHICH WILL CARRY OVER TO MN/WI FRIDAY NIGHT AS DISCUSSED IN MORE DETAIL IN THE LONG TERM SECTION. MEANWHILE...A NOCTURNAL THUNDERSTORM COMPLEX ONGOING ACROSS THE BADLANDS OF SOUTH DAKOTA WILL FALL APART BY THE TIME IT REACHES THE TWIN CITIES. THE 19.05 HRRR DEPICTS THIS...AND THE CAUSE IS A MORE STABLE AIRMASS...AS WELL AS SLIGHT LARGE SCALE SUBSIDENCE. AS A RESULT EXPECT NOTHING MORE THAN CONVECTIVE DEBRIS TODAY. SOUTHERLY WINDS WILL BRING TEMPERATURES NEAR 80 ACROSS MN...AND MID 70S IN WESTERN WI. A FEW AFTERNOON SHOWERS ARE POSSIBLE ACROSS FAR WESTERN MN WITH THE WARM AIR ADVECTION AHEAD OF A DEVELOPING SURFACE TROUGH. CONTINUED WITH 30 PERCENT CHANCE FOR PRECIP...BUT TRIMMED DOWN THE AREA CLOSER TO THE HIRES MODEL CONSENSUS. 925-850MB MOISTURE TRANSPORT BLOSSOMS ACROSS EASTERN SD AND WESTERN MN BY 06Z SATURDAY ON THE NOSE OF A 50 KT LOW LEVEL JET. THIS SHOULD HELP FUEL THE DIURNAL CONVECTION THAT IS EXPECTED TO HAVE DEVELOPED OVER THE WESTERN/CENTRAL DAKOTAS...AND ACCELERATE IT EASTWARD ACROSS THE FORECAST AREA OVERNIGHT AND SATURDAY MORNING. STILL LOOKS TO BE A POTENTIAL WIND- MAKER...ALTHOUGH IT SHOULD BE LOSING SOME STEAM AS IT WORKS EASTWARD INTO A MORE STABLE ENVIRONMENT. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 407 AM CDT FRI JUN 19 2015 AT DAYBREAK SATURDAY...THE AFOREMENTIONED LINE OF THUNDERSTORMS SHOULD BE ONGOING ACROSS WESTERN/CENTRAL MN. HI-RES MODELS INDICATE A QUASI-BOW STRUCTURE WILL DEVELOP...ALTHOUGH IT IS FORECAST TO DEINTENSIFY BY THE TIME IT REACHES THE I-35 CORRIDOR. BY 18Z SATURDAY...THE ACTIVITY SHOULD BE LIMITED TO SCATTERED SHOWERS OVER WEST CENTRAL WI DOWN INTO SOUTH CENTRAL MN. DEPENDING ON HOW MUCH CLEARING AND SUBSEQUENT DESTABILIZATION WE CAN TAP INTO...SHOULD SEE REDEVELOPMENT SATURDAY AFTERNOON ALONG THE COLD FRONT. SATURDAY AFTERNOON CONVECTION WILL HAVE A DECENT CHANCE OF BEING STRONG AGAIN. HOWEVER...IT IS CURRENTLY EXPECTED THAT THE NOCTURNAL CONVECTION WILL HELP PUSH THE BOUNDARY OUT OF THE MAJORITY OF THE FORECAST AREA...THUS REDUCING THE THREAT FOR SEVERE STORMS IN OUR FORECAST AREA. IF THE OVERNIGHT COMPLEX DOES NOT END UP BEING AS STRONG AS EXPECTED...SATURDAY AFTERNOON WILL LIKELY HAVE A HIGHER RISK FOR STRONG/SEVERE STORMS FROM CENTRAL/SOUTH CENTRAL MN EAST ACROSS WEST CENTRAL WI. ON SUNDAY INTO THE BEGINNING OF THE UPCOMING WEEK...THE FRONT WOBBLES IN AND OUT OF THE FORECAST AREA...AS EMBEDDED SHORTWAVES TRAVERSE THE FAST WESTERLY MID LEVEL FLOW REGIME. THERE WILL BE A THREAT FOR HEAVY RAINFALL ALONG THE BOUNDARY...ALTHOUGH THAT THREAT IS LOOKING MORE LIKELY TO LIE SOUTH OF THE AREA. TEMPERATURES THROUGH THE PERIOD LOOK TO BE NEAR NORMAL OVERALL...WITH A TEMPORARY UPTICK TO HIGHS IN THE 80S OVER THE WEEKEND. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 529 AM CDT FRI JUN 19 2015 VFR CONDITIONS TODAY. THE STORMS THAT ARE CURRENTLY ACROSS SOUTH DAKOTA ARE EXPECTED TO FALL APART THIS MORNING...AND NOT IMPACT THE TAF SITES. HOWEVER...A LINE OF THUNDERSTORMS IS EXPECTED TO DEVELOP TONIGHT BRINGING MVFR/IFR CONDITIONS AND POTENTIALLY GUSTY WINDS. TRIED TO TIME THE CONVECTION WITH A NARROW TEMPO WINDOW BASED ON THE CONSENSUS GUIDANCE OF SEVERAL HIRES MODELS. KMSP... WIND FORECAST THIS MORNING IS A CHALLENGE WITH LIGHT EASTERLY WINDS SHOWING SHOWING BOTH A NORTHERLY AND SOUTHERLY COMPONENT AT TIMES. FEEL THAT NORTHERLY COMPONENT MAY PERSIST FOR THE NEXT HOUR OR SO...BUT THE SOUTHERLY COMPONENT SHOULD BECOME MORE PROMINENT BY MID MORNING AS MIXING INCREASES. TIMING OF THE THUNDERSTORMS...WHICH WILL BE WEAKENING WHEN IT REACHES MSP...APPEARS TO BE CENTERED AROUND 10Z SATURDAY MORNING. /OUTLOOK FOR KMSP/ SAT...TSRA/RA LIKELY EARLY WITH MVFR CIGS POSSIBLE...WINDS SSW AT 10G15 KT. SUN...VFR WITH TSRA/SHRA POSSIBLE. WINDS W AT 5-10 KT. MON...VFR WITH TSRA/SHRA POSSIBLE. WIND N AT 5-10 KT. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...JRB/LS LONG TERM...LS AVIATION...JRB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
406 AM CDT FRI JUN 19 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 407 AM CDT FRI JUN 19 2015 EARLY MORNING WATER VAPOR IMAGERY TOGETHER WITH GFS 500MB HEIGHTS AND WINDS SHOWED AROUND 50KTS OF ZONAL FLOW FROM THE PACIFIC NORTHWEST TOWARD THE GREAT LAKES. BOOKENDING THIS ZONAL FLOW WERE TWO UPPER LEVEL LOWS...ONE OFF THE BRITISH COLUMBIA COAST...AND THE OTHER OVER NORTHERN QUEBEC. THE UPSTREAM LOW IS THE ONE OF MOST INTEREST...SINCE SHORTWAVE ENERGY ROTATING AROUND THIS LOW WILL BREAK OFF INTO THE ZONAL FLOW...CROSS THE ROCKIES...AND BE THE TRIGGER FOR HIGH PLAINS CONVECTION THIS AFTERNOON...WHICH WILL CARRY OVER TO MN/WI FRIDAY NIGHT AS DISCUSSED IN MORE DETAIL IN THE LONG TERM SECTION. MEANWHILE...A NOCTURNAL THUNDERSTORM COMPLEX ONGOING ACROSS THE BADLANDS OF SOUTH DAKOTA WILL FALL APART BY THE TIME IT REACHES THE TWIN CITIES. THE 19.05 HRRR DEPICTS THIS...AND THE CAUSE IS A MORE STABLE AIRMASS...AS WELL AS SLIGHT LARGE SCALE SUBSIDENCE. AS A RESULT EXPECT NOTHING MORE THAN CONVECTIVE DEBRIS TODAY. SOUTHERLY WINDS WILL BRING TEMPERATURES NEAR 80 ACROSS MN...AND MID 70S IN WESTERN WI. A FEW AFTERNOON SHOWERS ARE POSSIBLE ACROSS FAR WESTERN MN WITH THE WARM AIR ADVECTION AHEAD OF A DEVELOPING SURFACE TROUGH. CONTINUED WITH 30 PERCENT CHANCE FOR PRECIP...BUT TRIMMED DOWN THE AREA CLOSER TO THE HIRES MODEL CONSENSUS. 925-850MB MOISTURE TRANSPORT BLOSSOMS ACROSS EASTERN SD AND WESTERN MN BY 06Z SATURDAY ON THE NOSE OF A 50 KT LOW LEVEL JET. THIS SHOULD HELP FUEL THE DIURNAL CONVECTION THAT IS EXPECTED TO HAVE DEVELOPED OVER THE WESTERN/CENTRAL DAKOTAS...AND ACCELERATE IT EASTWARD ACROSS THE FORECAST AREA OVERNIGHT AND SATURDAY MORNING. STILL LOOKS TO BE A POTENTIAL WIND- MAKER...ALTHOUGH IT SHOULD BE LOSING SOME STEAM AS IT WORKS EASTWARD INTO A MORE STABLE ENVIRONMENT. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 407 AM CDT FRI JUN 19 2015 AT DAYBREAK SATURDAY...THE AFOREMENTIONED LINE OF THUNDERSTORMS SHOULD BE ONGOING ACROSS WESTERN/CENTRAL MN. HI-RES MODELS INDICATE A QUASI-BOW STRUCTURE WILL DEVELOP...ALTHOUGH IT IS FORECAST TO DEINTENSIFY BY THE TIME IT REACHES THE I-35 CORRIDOR. BY 18Z SATURDAY...THE ACTIVITY SHOULD BE LIMITED TO SCATTERED SHOWERS OVER WEST CENTRAL WI DOWN INTO SOUTH CENTRAL MN. DEPENDING ON HOW MUCH CLEARING AND SUBSEQUENT DESTABILIZATION WE CAN TAP INTO...SHOULD SEE REDEVELOPMENT SATURDAY AFTERNOON ALONG THE COLD FRONT. SATURDAY AFTERNOON CONVECTION WILL HAVE A DECENT CHANCE OF BEING STRONG AGAIN. HOWEVER...IT IS CURRENTLY EXPECTED THAT THE NOCTURNAL CONVECTION WILL HELP PUSH THE BOUNDARY OUT OF THE MAJORITY OF THE FORECAST AREA...THUS REDUCING THE THREAT FOR SEVERE STORMS IN OUR FORECAST AREA. IF THE OVERNIGHT COMPLEX DOES NOT END UP BEING AS STRONG AS EXPECTED...SATURDAY AFTERNOON WILL LIKELY HAVE A HIGHER RISK FOR STRONG/SEVERE STORMS FROM CENTRAL/SOUTH CENTRAL MN EAST ACROSS WEST CENTRAL WI. ON SUNDAY INTO THE BEGINNING OF THE UPCOMING WEEK...THE FRONT WOBBLES IN AND OUT OF THE FORECAST AREA...AS EMBEDDED SHORTWAVES TRAVERSE THE FAST WESTERLY MID LEVEL FLOW REGIME. THERE WILL BE A THREAT FOR HEAVY RAINFALL ALONG THE BOUNDARY...ALTHOUGH THAT THREAT IS LOOKING MORE LIKELY TO LIE SOUTH OF THE AREA. TEMPERATURES THROUGH THE PERIOD LOOK TO BE NEAR NORMAL OVERALL...WITH A TEMPORARY UPTICK TO HIGHS IN THE 80S OVER THE WEEKEND. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 106 AM CDT FRI JUN 19 2015 VFR CONDITIONS THROUGHOUT. EASTERLY WINDS WILL BECOME SOUTHERLY BY MID MORNING...WITH GUSTS NEAR 20KTS IN THE AFTERNOON. GUSTS WILL DECREASE AFTER SUNSET. THE POTENTIAL REMAINS FOR A THUNDERSTORM COMPLEX TO MOVE OUT OF THE DAKOTAS AND INTO MN/WI FRIDAY NIGHT. HANDLED THAT WITH A VCTS GROUP. KMSP... VFR THROUGHOUT. NO NOTEWORTHY DIFFERENCES FROM GENERAL AVIATION DISCUSSION /OUTLOOK FOR KMSP/ SAT...TSRA/RA LIKELY EARLY...WINDS SSW AT 10G15 KT. SUN...VFR WITH TSRA/SHRA POSSIBLE. WINDS W AT 5-10 KT. MON...VFR WITH TSRA/SHRA POSSIBLE. WIND N AT 5-10 KT. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...JRB/LS LONG TERM...LS AVIATION...JRB
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1007 AM CDT SAT JUN 20 2015 .UPDATE...NO CHANGES PLANNED TO THE FORECAST THIS MORNING. ISOLATED SHOWERS ARE ONGOING ALONG THE MS HIGHWAY 12 CORRIDOR BETWEEN HOLLANDALE AND TCHULA. ELSEWHERE AREAS OF LOW STRATUS WERE BEGINNING TO SCATTER OUT, ALLOWING FOR INCREASING INSOLATION. LATEST HIGH RES GUIDANCE CONSENSUS CONTINUES TO SUGGEST THE BEST OPPORTUNITY FOR CONVECTION THROUGH THE DAY WILL BE GENERALLY NORTH OF I-20, THOUGH A MOIST AIRMASS EXISTS ACROSS THE ENTIRE AREA AND AN ISOLATED SHOWER CANNOT BE RULED OUT FARTHER SOUTH. 12Z SOUNDINGS/LATEST MESOANALYSIS CONTINUE TO SUGGEST MARGINAL LAPSE RATES WILL HELP LIMIT STRONG STORM/WET MICROBURST THREAT. /DL/ && .AVIATION...MVFR CIGS WERE HANGING ON THIS MORNING A LITTLE LONGER THAN EXPECTED IN THE VERY MOIST SOUTHWEST FLOW ACROSS THE FORECAST AREA. CIGS WL CONTINUE TO RISE ABOVE 3KFT BY 17Z AND VFR CONDITIONS WL PREVAIL THIS AFTN INTO THE EVENING/OVERNIGHT. ISOLATED TO SCATTERED SHRA/TSRA WILL CONTINUE TO DEVELOP IN THE GLH/GWO/GTR CORRIDOR TODAY IN ASSOCIATION WITH DEPARTING TROPICAL DEPRESSION BILL...BUT EXPECT ANY CONVECTIVE ACTIVITY TO DISSIPATE QUICKLY THIS EVENING. IN FOLLOWING PERSISTENCE...WOULD EXPECT ANOTHER ROUND OF LOWER STRATUS LATE TONIGHT/EARLY SUNDAY MORNING. /22/EC/ && .DISCUSSION... /ISSUED AT 448 AM CDT SAT JUN 20 2015/ TODAY THROUGH SUNDAY NIGHT... TROPICAL DEPRESSION BILL WILL FINALLY DEPART THE REGION THIS WEEKEND...EVENTUALLY ALLOWING THE SUBTROPICAL RIDGE TO EXPAND AND INTENSIFY OVER THE ARKLAMISS. FOR TODAY...LINGERING ENERGY ASSOCIATED WITH THE EXITING TROPICAL SYSTEM WILL COMBINE WITH PRECIPITABLE WATER AIRMASS ~ 1.75 INCHES TO INCREASE SHOWER/TSTM CHANCES MAINLY NORTH OF THE I-2O CORRIDOR. ISOLATED CONVECTIVE ACTIVITY THIS MORNING IS FORECAST BY THE HRRR TO INCREASE DURING THE EARLY MORNING HOURS WITH COVERAGE PEAKING BY MID MORNING. POOR LAPSE RATES WITH VERTICAL TOTALS ~25 AND 0-3 KM LAPSE RATES GENERALLY LESS THAN 8 DEG C/KM WILL LIMIT MICROBURST POTENTIAL...BUT LOW/MID LEVEL FLOW OF 15-20 KTS WILL SUPPORT MULTICELL STORMS CAPABLE OF STRONG WIND GUSTS. CONVECTIVE PRECIPITATION SHOULD DIMINISH QUICKLY WITH SUNSET AS THE SUBTROPICAL RIDGE INCREASES OVER THE REGION. FOR SUNDAY INTO SUNDAY NIGHT EXPECT SHOWER/TSTM COVERAGE TO BE MORE DIURNAL IN NATURE WITH INCREASING BOUNDARY LAYER HEAT AND MID LEVEL LAPSE RATES PERHAPS HELPING TO INCREASE THUNDERSTORM INTENSITY. BUT THE OVERALL LACK OF FORCING/FOCUSING AND LIGHT FLOW SHOULD LIMIT STORM COVERAGE. HEAT STRESS WILL START TO INCREASE THIS WEEKEND WITH MAX HEAT INDICES GETTING UP TO OR SLIGHTLY ABOVE 100 DEG F. /EC/ MONDAY THROUGH FRIDAY... THE SUBTROPICAL RIDGE WILL REMAIN THE DOMINATE FEATURE OVER THE CWA THROUGH MUCH OF THE THE WORK WEEK. HOT AND VERY HUMID CONDITIONS DURING THIS TIME...HIGHS PEAKING IN THE MIDDLE 90S AND DEW POINTS IN THE LOW TO MID 70S...WILL LIKELY RESULT IN DANGEROUS HEAT INDICES MOST AFTERNOONS NEXT WEEK AS THEY`RE PROGGED TO RANGE BETWEEN 100-105F. THIS LEVEL OF HEAT WILL BE MONITORED THROUGH THE PERIOD AS HEAT ADVISORIES MAY BE NEEDED FOR PORTIONS OF THE AREA. RAIN CHANCES WILL ALSO BE CONFINED TO THE AFTERNOON AND EARLY EVENING HOURS AND LIMITED TO MAINLY ISOLATED STORMS. HOWEVER... MODELS DO SUGGEST THAT EASTERLY FLOW SOUTH OF THE AFOREMENTIONED RIDGE COULD INTERACT WITH CONVECTION ALONG THE SEABREEZE DURING THE WEEK. THIS COULD POTENTIALLY HELP TO INCREASE THE COVERAGE OF CONVECTION OVER THE SOUTHERN HALF OF FORECAST AREA MONDAY AND TUESDAY...THEN THE NORTHERN HALF OF THE CWA WEDNESDAY AND PERHAPS THURSDAY. AS FRIDAY ROLLS AROUND...MODELS ARE CURRENTLY IN AGREEMENT WITH THE RIDGE BEGINNING TO RETROGRADE WEST OF THE CWA. THIS WILL ALLOW A TROUGH TO BEGIN DIGGING SOUTH AND INTO THE DEEP SOUTH HEADING INTO WHAT WILL THEN BE THE UPCOMING WEEKEND. HOT HUMID CONDITIONS WILL PERSIST DURING THIS TIME...WITH ISOLATED CONVECTION POSSIBLE DURING THE AFTERNOON. /19/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 92 73 94 73 / 20 7 13 6 MERIDIAN 93 72 94 73 / 23 9 15 10 VICKSBURG 92 73 93 71 / 17 6 14 7 HATTIESBURG 94 74 95 74 / 13 8 18 14 NATCHEZ 90 73 91 72 / 13 5 21 15 GREENVILLE 94 75 94 74 / 25 7 9 5 GREENWOOD 92 74 93 74 / 39 11 8 5 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ DL/22/EC/19
AREA FORECAST DISCUSSION
NWS JACKSON MS
448 AM CDT SAT JUN 20 2015 .DISCUSSION... TODAY THROUGH SUNDAY NIGHT... TROPICAL DEPRESSION BILL WILL FINALLY DEPART THE REGION THIS WEEKEND...EVENTUALLY ALLOWING THE SUBTROPICAL RIDGE TO EXPAND AND INTENSIFY OVER THE ARKLAMISS. FOR TODAY...LINGERING ENERGY ASSOCIATED WITH THE EXITING TROPICAL SYSTEM WILL COMBINE WITH PRECIPITABLE WATER AIRMASS ~ 1.75 INCHES TO INCREASE SHOWER/TSTM CHANCES MAINLY NORTH OF THE I-2O CORRIDOR. ISOLATED CONVECTIVE ACTIVITY THIS MORNING IS FORECAST BY THE HRRR TO INCREASE DURING THE EARLY MORNING HOURS WITH COVERAGE PEAKING BY MID MORNING. POOR LAPSE RATES WITH VERTICAL TOTALS ~25 AND 0-3 KM LAPSE RATES GENERALLY LESS THAN 8 DEG C/KM WILL LIMIT MICROBURST POTENTIAL...BUT LOW/MID LEVEL FLOW OF 15-20 KTS WILL SUPPORT MULTICELL STORMS CAPABLE OF STRONG WIND GUSTS. CONVECTIVE PRECIPITATION SHOULD DIMINISH QUICKLY WITH SUNSET AS THE SUBTROPICAL RIDGE INCREASES OVER THE REGION. FOR SUNDAY INTO SUNDAY NIGHT EXPECT SHOWER/TSTM COVERAGE TO BE MORE DIURNAL IN NATURE WITH INCREASING BOUNDARY LAYER HEAT AND MID LEVEL LAPSE RATES PERHAPS HELPING TO INCREASE THUNDERSTORM INTENSITY. BUT THE OVERALL LACK OF FORCING/FOCUSING AND LIGHT FLOW SHOULD LIMIT STORM COVERAGE. HEAT STRESS WILL START TO INCREASE THIS WEEKEND WITH MAX HEAT INDICES GETTING UP TO OR SLIGHTLY ABOVE 100 DEG F. /EC/ MONDAY THROUGH FRIDAY... THE SUBTROPICAL RIDGE WILL REMAIN THE DOMINATE FEATURE OVER THE CWA THROUGH MUCH OF THE THE WORK WEEK. HOT AND VERY HUMID CONDITIONS DURING THIS TIME...HIGHS PEAKING IN THE MIDDLE 90S AND DEW POINTS IN THE LOW TO MID 70S...WILL LIKELY RESULT IN DANGEROUS HEAT INDICES MOST AFTERNOONS NEXT WEEK AS THEY`RE PROGGED TO RANGE BETWEEN 100-105F. THIS LEVEL OF HEAT WILL BE MONITORED THROUGH THE PERIOD AS HEAT ADVISORIES MAY BE NEEDED FOR PORTIONS OF THE AREA. RAIN CHANCES WILL ALSO BE CONFINED TO THE AFTERNOON AND EARLY EVENING HOURS AND LIMITED TO MAINLY ISOLATED STORMS. HOWEVER... MODELS DO SUGGEST THAT EASTERLY FLOW SOUTH OF THE AFOREMENTIONED RIDGE COULD INTERACT WITH CONVECTION ALONG THE SEABREEZE DURING THE WEEK. THIS COULD POTENTIALLY HELP TO INCREASE THE COVERAGE OF CONVECTION OVER THE SOUTHERN HALF OF FORECAST AREA MONDAY AND TUESDAY...THEN THE NORTHERN HALF OF THE CWA WEDNESDAY AND PERHAPS THURSDAY. AS FRIDAY ROLLS AROUND...MODELS ARE CURRENTLY IN AGREEMENT WITH THE RIDGE BEGINNING TO RETROGRADE WEST OF THE CWA. THIS WILL ALLOW A TROUGH TO BEGIN DIGGING SOUTH AND INTO THE DEEP SOUTH HEADING INTO WHAT WILL THEN BE THE UPCOMING WEEKEND. HOT HUMID CONDITIONS WILL PERSIST DURING THIS TIME...WITH ISOLATED CONVECTION POSSIBLE DURING THE AFTERNOON. /19/ .AVIATION...MVFR/IFR CATEGORY STRATUS DEVELOPING IN VERY MOIST SOUTHWEST FLOW ACROSS MUCH OF THE FORECAST AREA EARLY THIS MORNING WILL MIX UPWARD DURING MID/LATE MORNING HOURS FOLLOWED BY PREVAILING VFR CONDITIONS FOR THE AFTERNOON INTO THE EVENING/OVERNIGHT. SCATTERED SHRA/TSRA WILL CONTINUE TO DEVELOP IN THE GLH/GWO/GTR CORRIDOR TODAY IN ASSOCIATION WITH DEPARTING TROPICAL DEPRESSION BILL...BUT EXPECT ANY CONVECTIVE ACTIVITY TO DISSIPATE QUICKLY THIS EVENING. IN FOLLOWING PERSISTENCE...WOULD EXPECT ANOTHER ROUND OF LOWER STRATUS LATE TONIGHT/EARLY SUNDAY MORNING. /EC/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 92 73 94 73 / 20 7 13 6 MERIDIAN 93 72 94 73 / 23 9 15 10 VICKSBURG 92 73 93 71 / 17 6 14 7 HATTIESBURG 94 74 95 74 / 13 8 18 14 NATCHEZ 90 73 91 72 / 13 5 21 15 GREENVILLE 94 75 94 74 / 25 7 9 5 GREENWOOD 92 74 93 74 / 39 11 8 5 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ EC/19/
AREA FORECAST DISCUSSION
NWS BILLINGS MT
154 AM MDT FRI JUN 19 2015 .UPDATE... LAST OF SEVERE STORMS HAS EXITED CARTER COUNTY AND HAVE CANCELLED THE SEVERE THUNDERSTORM WATCH WHICH WAS IN EFFECT FOR POWDER RIVER AND CARTER COUNTIES...THOUGH WEAKER CONVECTION REMAINS AS FAR WEST AS ROSEBUD COUNTY. CLEARING SKIES AND DRY WX EXIST ACROSS OUR WEST HALF. JKL && .SHORT TERM...VALID FOR FRI AND SAT... CURRENT FORECAST CONTINUES TO LOOK ON TRACK WITH SEVERE THUNDERSTORMS A GOOD POSSIBILITY LATE THIS AFTERNOON THROUGH THE LATE EVENING HOURS AND INTO THE OVERNIGHT HOURS OUT TOWARD THE DAKOTA BORDERS. WEAK RIDGING OVER SOUTH CENTRAL MONTANA WILL FLATTEN WITH LOWERING HEIGHTS AS A SHORTWAVE OVER IDAHO MOVES ACROSS THE AREA. AN EASTERLY SURFACE FLOW COMBINED WITH LOW CLOUDS ACROSS THE FAR EAST HAS KEPT TEMPERATURES IN THE LOWER 60S SO FAR TODAY. SATELLITE IS SHOWING AREAS OF SUN ACROSS OUR CENTRAL ZONES WITH CONSIDERABLE CLOUDINESS MOVING IN FROM THE WEST. CURRENTLY BEST CAPES ARE WHERE THERE HAS BEEN SUN. EASTERLY SURFACE WINDS AND CLOUDS ARE KEEPING THE ATMOSPHERE CAPPED AND SOUNDINGS CONCUR WITH THIS. HOWEVER...AS THE SHORTWAVE APPROACHES AND MOVES OVER OUR AREA THE CAP IS EXPECTED TO BREAK BY LATE AFTERNOON. MAJORITY OF THE ENSEMBLE MODELS SHOW STORMS FIRING WEST OF BILLINGS BY LATE AFTERNOON AND MOVING EAST INTO THE BILLINGS AREA BY 7 OR 8 PM. HOWEVER...SOME MODELS TAKE THE STORMS JUST NORTH AND SOUTH OF BILLINGS SO UNCERTAINTY REMAINS ON EXACT LOCATIONS OF STORM DEVELOPMENT. ALL PARAMETERS POINT TO THE POSSIBILITY OF ANY STORM CONTAINING LARGE HAIL AND DAMAGING WINDS. MODELS THEN SHOW INDIVIDUAL STORMS FORMING MORE OF A COMPLEX OF STORMS JUST EAST OF BILLINGS BY MID EVENING. LATEST HRRR MODEL RUN IS NOW SHOWING A COUPLE SUPERCELLS DEVELOPING BY LATE AFTERNOON ACROSS SOUTHERN ROSEBUD...POWDER RIVER AND CARTER COUNTIES. ALL THE MODELS AGREE ON MERGING THE STORMS INTO AN MCS LATE THIS EVENING THROUGH THE EARLY MORNING HOURS FRIDAY FOR OUR FAR EASTERN COUNTIES. WE REMAIN CONCERNED WITH THE CURRENT CAP BUT WE STILL BELIEVE IT WILL BREAK IN PLACES. LATEST MODEL GUIDANCE ACTUALLY SHOWS FRIDAY TO HAVE BETTER CHANCES FOR A SEVERE THUNDERSTORM EVENT THAN TODAY. HOWEVER...UNCERTAINTY DOES EXIST AS TONIGHTS STORMS MAY PLACE A ROLE IN HOW THE ATMOSPHERE WILL REACT FRIDAY. MODEL GUIDANCE IS HIGHLIGHTING AREAS FROM BILLINGS EASTWARD WITH THE POSSIBILITY OF A DAMAGING WIND EVENT. THE WEEKEND IS LOOKING TO BE LESS ACTIVE AS A MORE STABLE AIRMASS WORKS ITS WAY INTO THE FORECAST AREA. THERE WILL STILL BE A SLIGHT CHANCE FOR A THUNDERSTORM SATURDAY AFTERNOON/EVENING BUT SEVERE WEATHER IS NOT ANTICIPATED AT THIS TIME. HOOLEY .LONG TERM...VALID FOR SUN...MON...TUE...WED...THU... A FAST FLOW ALOFT WILL CONTINUE OVER THE FORECAST AREA THROUGH THE EXTENDED PERIOD. WHILE THE ENSEMBLES WERE IN GENERAL AGREEMENT OVER THE UPCOMING PATTERN...THERE WERE SOME DIFFERENCES IN THE DETAILS OF THE DETERMINISTIC GFS AND ECMWF. SUN AND SUN NIGHT WILL BE MAINLY DRY ACROSS THE AREA AS RIDGING MOVES OVER THE AREA. SOME ENERGY AND MOISTURE MOVES THROUGH THE FLOW MON AND MON NIGHT BRINGING A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS TO THE REGION. MODELS DISAGREED ON THE PROGRESSION OF A PACIFIC SHORTWAVE TUE AND TUE NIGHT SO LEFT INHERITED POPS ACROSS THE AREA ALONE. DIFFERENCES CONTINUED THROUGH WED NIGHT DUE TO THE PACIFIC WAVE...SO AGAIN MADE NO CHANGES. THE GFS SHOWED HIGH CAPES OVER CENTRAL AND EASTERN PARTS OF THE AREA TUE AFTERNOON THROUGH WED...AND BULK SHEAR WAS STRONG AS WELL. THE GFS WAS STRONGER WITH THE SHORTWAVE THAN THE ECMWF...SO IF THE GFS VERIFIES...THERE WILL BE POSSIBLE STRONG TO SEVERE STORMS TUE AFTERNOON THROUGH WED. NW FLOW ALOFT WILL SUPPORT LOW PRECIPITATION CHANCES ON THU. HIGH TEMPERATURES THROUGH THE PERIOD WILL REACH INTO THE 80S WHICH IS A LITTLE ABOVE NORMAL. ARTHUR && .AVIATION... THUNDERSTORMS WILL MOVE OUT OF SOUTH CENTRAL AND INTO SOUTHEASTERN MT BY ABOUT 06 UTC...AND THEN EXIT SOUTHEASTERN MT BY 12 UTC. MVFR TO IFR CONDITIONS WITH STRONG WINDS...HAIL AND HEAVY RAINFALL WILL ACCOMPANY THE STRONGEST CELLS. ANOTHER ROUND OF STRONG TO SEVERE THUNDERSTORMS IS POSSIBLE FRIDAY AFTERNOON AND EVENING. SCHULTZ && .PRELIMINARY POINT TEMP/POPS... FRI SAT SUN MON TUE WED THU ----------------------------------------------------------- BIL 061/084 056/081 056/080 055/084 058/083 059/082 059/085 13/T 22/T 21/B 12/T 22/T 33/T 32/T LVM 054/083 047/079 048/081 050/083 051/083 051/081 050/085 14/T 22/T 21/B 22/T 23/T 33/T 32/T HDN 060/087 056/082 055/081 056/086 057/085 058/084 059/086 13/T 42/T 21/B 11/B 12/T 33/T 32/T MLS 061/086 057/081 055/080 055/081 058/082 060/081 057/082 43/T 41/B 22/W 12/T 22/T 33/T 32/T 4BQ 061/086 056/080 056/081 056/083 059/082 059/081 057/082 83/T 61/B 22/W 22/T 22/T 33/T 32/T BHK 060/084 055/080 053/078 053/077 056/078 058/078 054/078 63/T 61/U 22/T 22/T 22/T 44/T 32/T SHR 056/084 052/077 052/078 053/084 055/083 055/080 054/082 13/T 52/T 21/B 11/B 12/T 32/T 22/T && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
1108 PM MDT THU JUN 18 2015 .UPDATE... WE HAVE ISSUED A SEVERE THUNDERSTORM WATCH FOR POWDER RIVER AND CARTER COUNTIES DOWNSTREAM OF THE INTENSE...BUT SMALL AND BOWING MCS WHICH IS CENTERED ON TONGUE RIVER RESERVOIR AT 11 PM MDT. THE SEVERE STORMS ARE WELL-ORGANIZED NOW WITH IMPRESSIVE MID-ALTITUDE RADIAL CONVERGENCE SIGNATURES INDICATIVE OF SEVERE WINDS AT THE SURFACE. THE WATCH GOES UNTIL 5 AM MDT...BUT WILL LIKELY BE CANCELLED MUCH EARLIER THAN THAT ONCE THE STORMS MOVE PAST THOSE COUNTIES. THE RISK OF SEVERE STORMS ELSEWHERE IS LIKELY OVER FOR THE NIGHT. SCHULTZ PREVIOUS UPDATE...ISSUED AT 810 PM MDT THU JUN 18 2015... CONVECTION NEAR BIG TIMBER IS INTENSIFYING JUST BEFORE 8 PM...BUT IT REMAINS TO BE SEEN IF IT WILL BE ABLE TO MAINTAIN ITS INTENSITY DOWNSTREAM WHERE THE AIR MASS IS AND HAS BEEN UNDER THE INFLUENCE OF A RATHER STRONG CAP. WE ARE NONETHELESS MAINTAINING A MENTION OF SEVERE THUNDERSTORMS ALONG AND AHEAD OF THE CURRENT ACTIVITY... WHICH WILL LIKELY MAINTAIN ITSELF IN SOME MANNER INTO SOUTHEASTERN MT OVERNIGHT GIVEN A NOCTURNAL 40-50 KT LOW-LEVEL JET. ALL WE DID FOR THE EVENING FORECAST UPDATE WAS ADJUST BOTH POPS AND HOURLY TEMPERATURES BASED ON RECENT OBSERVATIONAL TRENDS. SCHULTZ && .SHORT TERM...VALID FOR FRI AND SAT... CURRENT FORECAST CONTINUES TO LOOK ON TRACK WITH SEVERE THUNDERSTORMS A GOOD POSSIBILITY LATE THIS AFTERNOON THROUGH THE LATE EVENING HOURS AND INTO THE OVERNIGHT HOURS OUT TOWARD THE DAKOTA BORDERS. WEAK RIDGING OVER SOUTH CENTRAL MONTANA WILL FLATTEN WITH LOWERING HEIGHTS AS A SHORTWAVE OVER IDAHO MOVES ACROSS THE AREA. AN EASTERLY SURFACE FLOW COMBINED WITH LOW CLOUDS ACROSS THE FAR EAST HAS KEPT TEMPERATURES IN THE LOWER 60S SO FAR TODAY. SATELLITE IS SHOWING AREAS OF SUN ACROSS OUR CENTRAL ZONES WITH CONSIDERABLE CLOUDINESS MOVING IN FROM THE WEST. CURRENTLY BEST CAPES ARE WHERE THERE HAS BEEN SUN. EASTERLY SURFACE WINDS AND CLOUDS ARE KEEPING THE ATMOSPHERE CAPPED AND SOUNDINGS CONCUR WITH THIS. HOWEVER...AS THE SHORTWAVE APPROACHES AND MOVES OVER OUR AREA THE CAP IS EXPECTED TO BREAK BY LATE AFTERNOON. MAJORITY OF THE ENSEMBLE MODELS SHOW STORMS FIRING WEST OF BILLINGS BY LATE AFTERNOON AND MOVING EAST INTO THE BILLINGS AREA BY 7 OR 8 PM. HOWEVER...SOME MODELS TAKE THE STORMS JUST NORTH AND SOUTH OF BILLINGS SO UNCERTAINTY REMAINS ON EXACT LOCATIONS OF STORM DEVELOPMENT. ALL PARAMETERS POINT TO THE POSSIBILITY OF ANY STORM CONTAINING LARGE HAIL AND DAMAGING WINDS. MODELS THEN SHOW INDIVIDUAL STORMS FORMING MORE OF A COMPLEX OF STORMS JUST EAST OF BILLINGS BY MID EVENING. LATEST HRRR MODEL RUN IS NOW SHOWING A COUPLE SUPERCELLS DEVELOPING BY LATE AFTERNOON ACROSS SOUTHERN ROSEBUD...POWDER RIVER AND CARTER COUNTIES. ALL THE MODELS AGREE ON MERGING THE STORMS INTO AN MCS LATE THIS EVENING THROUGH THE EARLY MORNING HOURS FRIDAY FOR OUR FAR EASTERN COUNTIES. WE REMAIN CONCERNED WITH THE CURRENT CAP BUT WE STILL BELIEVE IT WILL BREAK IN PLACES. LATEST MODEL GUIDANCE ACTUALLY SHOWS FRIDAY TO HAVE BETTER CHANCES FOR A SEVERE THUNDERSTORM EVENT THAN TODAY. HOWEVER...UNCERTAINTY DOES EXIST AS TONIGHTS STORMS MAY PLACE A ROLE IN HOW THE ATMOSPHERE WILL REACT FRIDAY. MODEL GUIDANCE IS HIGHLIGHTING AREAS FROM BILLINGS EASTWARD WITH THE POSSIBILITY OF A DAMAGING WIND EVENT. THE WEEKEND IS LOOKING TO BE LESS ACTIVE AS A MORE STABLE AIRMASS WORKS ITS WAY INTO THE FORECAST AREA. THERE WILL STILL BE A SLIGHT CHANCE FOR A THUNDERSTORM SATURDAY AFTERNOON/EVENING BUT SEVERE WEATHER IS NOT ANTICIPATED AT THIS TIME. HOOLEY .LONG TERM...VALID FOR SUN...MON...TUE...WED...THU... A FAST FLOW ALOFT WILL CONTINUE OVER THE FORECAST AREA THROUGH THE EXTENDED PERIOD. WHILE THE ENSEMBLES WERE IN GENERAL AGREEMENT OVER THE UPCOMING PATTERN...THERE WERE SOME DIFFERENCES IN THE DETAILS OF THE DETERMINISTIC GFS AND ECMWF. SUN AND SUN NIGHT WILL BE MAINLY DRY ACROSS THE AREA AS RIDGING MOVES OVER THE AREA. SOME ENERGY AND MOISTURE MOVES THROUGH THE FLOW MON AND MON NIGHT BRINGING A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS TO THE REGION. MODELS DISAGREED ON THE PROGRESSION OF A PACIFIC SHORTWAVE TUE AND TUE NIGHT SO LEFT INHERITED POPS ACROSS THE AREA ALONE. DIFFERENCES CONTINUED THROUGH WED NIGHT DUE TO THE PACIFIC WAVE...SO AGAIN MADE NO CHANGES. THE GFS SHOWED HIGH CAPES OVER CENTRAL AND EASTERN PARTS OF THE AREA TUE AFTERNOON THROUGH WED...AND BULK SHEAR WAS STRONG AS WELL. THE GFS WAS STRONGER WITH THE SHORTWAVE THAN THE ECMWF...SO IF THE GFS VERIFIES...THERE WILL BE POSSIBLE STRONG TO SEVERE STORMS TUE AFTERNOON THROUGH WED. NW FLOW ALOFT WILL SUPPORT LOW PRECIPITATION CHANCES ON THU. HIGH TEMPERATURES THROUGH THE PERIOD WILL REACH INTO THE 80S WHICH IS A LITTLE ABOVE NORMAL. ARTHUR && .AVIATION... THUNDERSTORMS WITH STRONG WINDS...HAIL AND HEAVY RAINFALL WILL CROSS FAR SOUTHEASTERN MT OVERNIGHT...MOVING INTO SD BY 11 UTC. ANOTHER ROUND OF STRONG TO SEVERE THUNDERSTORMS IS POSSIBLE ACROSS THE WHOLE AREA ON FRIDAY AFTERNOON AND EVENING. SCHULTZ && .PRELIMINARY POINT TEMP/POPS... FRI SAT SUN MON TUE WED THU ----------------------------------------------------------- BIL 061/084 056/081 056/080 055/084 058/083 059/082 059/085 43/T 22/T 21/B 12/T 22/T 33/T 32/T LVM 054/083 047/079 048/081 050/083 051/083 051/081 050/085 34/T 22/T 21/B 22/T 23/T 33/T 32/T HDN 060/087 056/082 055/081 056/086 057/085 058/084 059/086 43/T 42/T 21/B 11/B 12/T 33/T 32/T MLS 061/086 057/081 055/080 055/081 058/082 060/081 057/082 63/T 41/B 22/W 12/T 22/T 33/T 32/T 4BQ 061/086 056/080 056/081 056/083 059/082 059/081 057/082 93/T 61/B 22/W 22/T 22/T 33/T 32/T BHK 060/084 055/080 053/078 053/077 056/078 058/078 054/078 63/T 61/U 22/T 22/T 22/T 44/T 32/T SHR 056/084 052/077 052/078 053/084 055/083 055/080 054/082 23/T 52/T 21/B 11/B 12/T 32/T 22/T && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...SEVERE THUNDERSTORM WATCH 312 IN EFFECT UNTIL 5 AM MDT FRIDAY FOR ZONES 36-37. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
659 PM CDT SAT JUN 20 2015 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 324 PM CDT SAT JUN 20 2015 UPPER AIR AND SATELLITE DATA SHOW THE AREA SITTING UNDER GENERALLY ZONAL FLOW...AN AREA OF HIGH PRESSURE IS SETTLED OVER THE SWRN COAST...WHILE LOW PRESSURE SLIDES EAST ACROSS THE MIDWEST. ANOTHER SHORTWAVE DISTURBANCE IS MOVING ACROSS NRN MN INTO THE GREAT LAKES REGION...WITH IT BEING RESPONSIBLE FOR THE FRONTAL BOUNDARY ACROSS THE AREA. AS EXPECTED...THE FRONT HAS GRADUALLY SAGGED SOUTH THROUGH THE DAY...AND CURRENTLY SITS ACROSS THE FAR SERN CORNER OF THE CWA. STARTING AROUND MID MORNING...HAD A FEW ISOLATED SHOWERS AND RUMBLES OF THUNDER DEVELOP ALONG THE FRONT...ENDED UP THROWING SOME SLIGHT POPS IN THE FORECAST. SINCE THEN...HASNT BEEN ANY INCREASE IN ACTIVITY...WITH THE SPC MESO PAGE SHOWING CAPPING IN PLACE WITH 700MB TEMPS AROUND 14C. HASNT BEEN ANY SURPRISES WITH TEMPERATURES OR DPTS...WITH 3 PM OBS RANGING FROM THE LOWER 80S IN THE FAR NORTH TO MID 90S IN THE SOUTHEAST. HEAT INDEX VALUES HAVE REACH NEAR 100 IN THE FAR SOUTHEAST. THE RAP AND HRRR CONTINUE TO SHOW THAT LATE THIS AFTERNOON /BANKING ON A WEAKENING CAP/ THAT THUNDERSTORMS WILL DEVELOP ALONG THE FRONT ACROSS THE EXTREME SE CORNER OF THE CWA...AND WILL CONTINUE TO CARRY SOME SLIGHT POPS IN THAT AREA...OTHER MODELS SHOW NOTHING DEVELOPING. OUTSIDE OF THAT...THE EVENING HOURS ARE EXPECTED TO BE DRY. LATER TONIGHT AND INTO A PORTION OF THE DAY TOMORROW...CONTINUED TO CARRY THE POPS ACROSS ROUGHLY THE NRN HALF OF THE CWA...WITH MODELS SHOWING ANOTHER WEAK UPPER LEVEL SHORTWAVE DISTURBANCE MOVING OUT OF THE ROCKIES. LITTLE UNCERTAINTY WITH THE TIMING...AND OVERALL COVERAGE...WITH THE LATEST HRRR COMING IN WITH MORE ACTIVITY THAN BASICALLY ANY OTHER MODEL. WILL HAVE TO SEE HOW UPCOMING MODEL RUN TRENDS AND MONITOR ACTIVITY TO THE W/NW THIS EVENING...AND ADJUST AS NECESSARY. AT THIS POINT...KEPT THOSE POPS CONFINED TO AFTER 06Z...CONTINUING INTO THE FIRST HALF OF THE DAY TOMORROW...WITH A DRY AFTERNOON. AT THE SFC...EXPECTING HIGHER PRESSURE TO SETTLE IN ACROSS THE AREA TONIGHT...RESULTING IN LIGHTER WINDS...BUT BECOMING MORE E/SERLY WITH TIME. LOW PRESSURE BECOMES ORGANIZED TOMORROW OVER THE HIGH PLAINS...WITH THE POTENTIAL FOR A WARM FRONTAL BOUNDARY TO SET UP NEAR THE STATE LINE. MODELS SHOW THAT SERLY COMPONENT TO THE WINDS REMAINING MAINLY OVER NEB...WITH MORE SRLY WINDS OVER NC KS. AS FAR AS TEMPERATURES GO...CURRENT FORECAST CALLS FOR CONDITIONS SIMILAR TO TODAY...MID 80S IN THE NORTH...MID/UPPER 90S IN THE S/SW. LOOKING AT HEAT INDEX VALUES AROUND 100 AGAIN POSSIBLE ROUGHLY NEAR/SOUTH OF THE STATE LINE. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 324 PM CDT SAT JUN 20 2015 GUIDANCE SUGGESTS UPPER TROPOSPHERIC RIDGING WILL BE NOTED OVER THE WESTERN HALF OF THE CONUS TO START THE LONG-TERM FORECAST PERIOD AT 00 MONDAY. THIS RIDGE IS EXPECTED TO WEAKEN SOMEWHAT THROUGH WEDNESDAY...WITH A STRENGTHENING RIDGE ACROSS THE WESTERN CONUS EXPECTED THURSDAY ONWARD. AS A RESULT...QUASI-ZONAL TO AT TIME NORTHWESTERLY UPPER TROPOSPHERIC FLOW IS EXPECTED OVER OUR AREA MONDAY THROUGH WEDNESDAY...WITH INCREASINGLY NORTHWESTERLY FLOW THURSDAY ONWARD. STARTING WITH SUNDAY NIGHT INTO EARLY MONDAY MORNING...GUIDANCE CONTINUES SHIFTING ANY APPRECIABLE CHANCE AT PRECIPITATION TO THE NORTH/NORTHEAST OF OUR AREA...MORE ALONG THE PRIMARY AXIS OF ENHANCED UPPER TROPOSPHERIC FLOW. ALTHOUGH THE OPERATIONAL GFS DOES SUGGEST A VERY ISOLATED AREA ACROSS OUR FAR NORTHWESTERN CWA COULD SEE PRECIPITATION EARLY MONDAY MORNING...THIS OUTPUT IS THE OUTLIER WHEN COMPARED TO THE NAM AND EC WHICH BOTH KEEP ANY PRECIPITATION WELL TO OUR NORTH/NORTHEAST. GIVEN THIS...OPTED TO GO AHEAD WITH DRY CONDITIONS SUNDAY NIGHT INTO EARLY MONDAY MORNING. DRY CONDITIONS ALSO REMAIN IN THE FORECAST DURING THE DAY MONDAY AND MONDAY EVENING AS AN OVERALL LACK IN OMEGA PERSISTS ACROSS THE REGION. STARTING EARLY TUESDAY MORNING AND CONTINUING INTO THE DAY TUESDAY...A SUBTLE PERTURBATION ADVANCING EAST/NORTHEAST FROM THE MID ROCKIES...MOST EVIDENT NEAR 700MB PER MODEL GUIDANCE...COULD BRING OUR NEXT CHANCE FOR PRECIPITATION...ESPECIALLY ACROSS CENTRAL AND NORTHERN PORTIONS OF THE CWA. THIS IS A SOLUTION SUPPORTED BY QPF FIELDS FROM THE NAM AND OPERATIONAL GFS...AND TO A LESSER EXTENT THE EC. GIVEN THIS...OPTED TO GO AHEAD WITH 20-30% POPS ACROSS CENTRAL AND NORTHERN PORTIONS OF THE CWA EARLY TUESDAY MORNING THROUGH THE DAY TUESDAY. TUESDAY NIGHT AND BEYOND...AS PREVIOUSLY MENTIONED...INCREASING NORTHWESTERLY UPPER TROPOSPHERIC FLOW SHOULD DEVELOP OVER OUR AREA A THE WESTERN CONUS RIDGE STRENGTHENS...THUS INCREASING THE CHANCES FOR MULTIPLE SMALL-SCALE PERTURBATION TO CLEAR THE REGION. AS MENTIONED BY THE PREVIOUS SHIFT...CONFIDENCE WITH RESPECT TO THE REALIZATION OF PRECIPITATION ON ANY GIVEN DAY DURING THIS TIME PERIOD REMAINS LOW...BUT ITS HARD TO JUSTIFY A DRY FORECAST BASED ON MODEL GUIDANCE AND AS A RESULT...WENT AHEAD AND MAINTAINED POPS...GENERALLY IN THE 20-40% RANGE...ACROSS MUCH OF THE AREA TUESDAY NIGHT THROUGH SATURDAY. GUIDANCE SUGGESTS RESPECTABLE VALUES OF LOWER TROPOSPHERIC MOISTURE...WORKING IN CONCERT WITH VARYING LAPSE RATES WITH THE PASSAGE OF UPPER TROPOSPHERIC PERTURBATIONS...WILL PRESENT POTENTIAL ENERGY VALUES GENERALLY IN THE 1000-3000J/KG RANGE EACH DAY DURING THE LONG-TERM FORECAST PERIOD. DEEP-LAYER BULK SHEAR OF ~30KTS WILL ALSO BE POSSIBLE AS THE ENHANCED UPPER TROPOSPHERIC FLOW ESTABLISHES ITSELF OVER THE REGION. THAT SAID...FORECAST PROXIMITY SOUNDINGS FROM THE ACROSS THE CWA...PER THE NAM AND OPERATIONAL GFS...SUGGEST A HEALTHY LOWER TROPOSPHERIC CAPPING INVERSION WILL BE PRESENT EACH DAY AND WITH OMEGA REMAINING ON THE QUESTIONABLE SIDE...ITS HARD TO SAY THAT ANY ONE DAY HAS A GREATER CHANCE OF SEVERE WEATHER OVER THE NEXT. OBVIOUSLY...ANY DAY THAT CAN REALIZE CONVECTIVE INITIALIZATION WILL HAVE AT LEAST A CHANCE OF STRONG TO SEVERE THUNDERSTORM ACTIVITY...BUT CONFIDENCE IS NOT HIGH ENOUGH TO DEFINITIVELY MENTION SUCH CONDITIONS IN THE HWO. GIVEN THIS...FOR THE HWO...WILL SIMPLY STATE THAT SEVERE CONVECTION IS NOT OUT OF THE QUESTION DURING THE LONG-TERM FORECAST PERIOD...AND THE FORECAST WILL NEED TO BE MONITORED FOR THE POSSIBILITY OF SEVERE WEATHER DURING THE MIDDLE TO LATE PART OF NEXT WEEK. PRE-FRONTAL WARMING AHEAD OF A BOUNDARY-LAYER BAROCLINIC ZONE COULD PRESENT A VERY WARM DAY ON MONDAY..WITH GUIDANCE CURRENTLY SUGGESTING AFTERNOON TEMPERATURE READINGS COULD SPIKE TO AROUND 100 DEGREES MONDAY AFTERNOON ACROSS OUR SOUTHERN ZONES...AND MORE INTO THE 90S FARTHER NORTH ACROSS THE AREA. ITS IMPORTANT TO NOTE THAT FRONTAL POSITION WILL PLAY A CRUCIAL ROLE IN TEMPERATURE READINGS ON MONDAY AND THIS WILL NEED TO BE CLOSELY MONITORED. THE INFILTRATION OF A COOLER BOUNDARY-LAYER AIR MASS POST-FROPA SHOULD THEN ALLOW FOR HIGHS IN THE 80S AND LOW 90S TO FINISH THE FORECAST PERIOD. FINALLY...RESULTANT HEAT INDEX READINGS MONDAY AFTERNOON ARE EXPECTED TO CLIMB INTO THE 100-105 RANGE ACROSS OUR KANSAS COUNTIES AND AS A RESULT...WILL CONTINUE MENTIONING THIS IN THE HWO. && .AVIATION...(FOR THE 00Z KGRI/KEAR TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 650 PM CDT SAT JUN 20 2015 VFR CONDITIONS ARE EXPECTED AT BOTH TERMINALS THROUGH THE PERIOD. EXPECT GUSTY NORTHWESTERLY WINDS TO SUBSIDE OVER THE NEXT HOUR OR TWO...WITH WINDS SHIFTING AND BECOMING SOUTHEASTERLY TOMORROW. MAY SEE SOME MID LEVEL CLOUDS ENCROACH ON THE TERMINALS OVERNIGHT AND ON SUNDAY...AS A DISTURBANCE FROM SOUTH DAKOTA MOVES ACROSS THE REGION...BUT THESE CLOUDS ARE NOT EXPECTED TO HAVE AN IMPACT ON CONDITIONS. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...ADP LONG TERM...BRYANT AVIATION...ROSSI
AREA FORECAST DISCUSSION
NWS HASTINGS NE
326 PM CDT SAT JUN 20 2015 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 324 PM CDT SAT JUN 20 2015 UPPER AIR AND SATELLITE DATA SHOW THE AREA SITTING UNDER GENERALLY ZONAL FLOW...AN AREA OF HIGH PRESSURE IS SETTLED OVER THE SWRN COAST...WHILE LOW PRESSURE SLIDES EAST ACROSS THE MIDWEST. ANOTHER SHORTWAVE DISTURBANCE IS MOVING ACROSS NRN MN INTO THE GREAT LAKES REGION...WITH IT BEING RESPONSIBLE FOR THE FRONTAL BOUNDARY ACROSS THE AREA. AS EXPECTED...THE FRONT HAS GRADUALLY SAGGED SOUTH THROUGH THE DAY...AND CURRENTLY SITS ACROSS THE FAR SERN CORNER OF THE CWA. STARTING AROUND MID MORNING...HAD A FEW ISOLATED SHOWERS AND RUMBLES OF THUNDER DEVELOP ALONG THE FRONT...ENDED UP THROWING SOME SLIGHT POPS IN THE FORECAST. SINCE THEN...HASNT BEEN ANY INCREASE IN ACTIVITY...WITH THE SPC MESO PAGE SHOWING CAPPING IN PLACE WITH 700MB TEMPS AROUND 14C. HASNT BEEN ANY SURPRISES WITH TEMPERATURES OR DPTS...WITH 3 PM OBS RANGING FROM THE LOWER 80S IN THE FAR NORTH TO MID 90S IN THE SOUTHEAST. HEAT INDEX VALUES HAVE REACH NEAR 100 IN THE FAR SOUTHEAST. THE RAP AND HRRR CONTINUE TO SHOW THAT LATE THIS AFTERNOON /BANKING ON A WEAKENING CAP/ THAT THUNDERSTORMS WILL DEVELOP ALONG THE FRONT ACROSS THE EXTREME SE CORNER OF THE CWA...AND WILL CONTINUE TO CARRY SOME SLIGHT POPS IN THAT AREA...OTHER MODELS SHOW NOTHING DEVELOPING. OUTSIDE OF THAT...THE EVENING HOURS ARE EXPECTED TO BE DRY. LATER TONIGHT AND INTO A PORTION OF THE DAY TOMORROW...CONTINUED TO CARRY THE POPS ACROSS ROUGHLY THE NRN HALF OF THE CWA...WITH MODELS SHOWING ANOTHER WEAK UPPER LEVEL SHORTWAVE DISTURBANCE MOVING OUT OF THE ROCKIES. LITTLE UNCERTAINTY WITH THE TIMING...AND OVERALL COVERAGE...WITH THE LATEST HRRR COMING IN WITH MORE ACTIVITY THAN BASICALLY ANY OTHER MODEL. WILL HAVE TO SEE HOW UPCOMING MODEL RUN TRENDS AND MONITOR ACTIVITY TO THE W/NW THIS EVENING...AND ADJUST AS NECESSARY. AT THIS POINT...KEPT THOSE POPS CONFINED TO AFTER 06Z...CONTINUING INTO THE FIRST HALF OF THE DAY TOMORROW...WITH A DRY AFTERNOON. AT THE SFC...EXPECTING HIGHER PRESSURE TO SETTLE IN ACROSS THE AREA TONIGHT...RESULTING IN LIGHTER WINDS...BUT BECOMING MORE E/SERLY WITH TIME. LOW PRESSURE BECOMES ORGANIZED TOMORROW OVER THE HIGH PLAINS...WITH THE POTENTIAL FOR A WARM FRONTAL BOUNDARY TO SET UP NEAR THE STATE LINE. MODELS SHOW THAT SERLY COMPONENT TO THE WINDS REMAINING MAINLY OVER NEB...WITH MORE SRLY WINDS OVER NC KS. AS FAR AS TEMPERATURES GO...CURRENT FORECAST CALLS FOR CONDITIONS SIMILAR TO TODAY...MID 80S IN THE NORTH...MID/UPPER 90S IN THE S/SW. LOOKING AT HEAT INDEX VALUES AROUND 100 AGAIN POSSIBLE ROUGHLY NEAR/SOUTH OF THE STATE LINE. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 324 PM CDT SAT JUN 20 2015 GUIDANCE SUGGESTS UPPER TROPOSPHERIC RIDGING WILL BE NOTED OVER THE WESTERN HALF OF THE CONUS TO START THE LONG-TERM FORECAST PERIOD AT 00 MONDAY. THIS RIDGE IS EXPECTED TO WEAKEN SOMEWHAT THROUGH WEDNESDAY...WITH A STRENGTHENING RIDGE ACROSS THE WESTERN CONUS EXPECTED THURSDAY ONWARD. AS A RESULT...QUASI-ZONAL TO AT TIME NORTHWESTERLY UPPER TROPOSPHERIC FLOW IS EXPECTED OVER OUR AREA MONDAY THROUGH WEDNESDAY...WITH INCREASINGLY NORTHWESTERLY FLOW THURSDAY ONWARD. STARTING WITH SUNDAY NIGHT INTO EARLY MONDAY MORNING...GUIDANCE CONTINUES SHIFTING ANY APPRECIABLE CHANCE AT PRECIPITATION TO THE NORTH/NORTHEAST OF OUR AREA...MORE ALONG THE PRIMARY AXIS OF ENHANCED UPPER TROPOSPHERIC FLOW. ALTHOUGH THE OPERATIONAL GFS DOES SUGGEST A VERY ISOLATED AREA ACROSS OUR FAR NORTHWESTERN CWA COULD SEE PRECIPITATION EARLY MONDAY MORNING...THIS OUTPUT IS THE OUTLIER WHEN COMPARED TO THE NAM AND EC WHICH BOTH KEEP ANY PRECIPITATION WELL TO OUR NORTH/NORTHEAST. GIVEN THIS...OPTED TO GO AHEAD WITH DRY CONDITIONS SUNDAY NIGHT INTO EARLY MONDAY MORNING. DRY CONDITIONS ALSO REMAIN IN THE FORECAST DURING THE DAY MONDAY AND MONDAY EVENING AS AN OVERALL LACK IN OMEGA PERSISTS ACROSS THE REGION. STARTING EARLY TUESDAY MORNING AND CONTINUING INTO THE DAY TUESDAY...A SUBTLE PERTURBATION ADVANCING EAST/NORTHEAST FROM THE MID ROCKIES...MOST EVIDENT NEAR 700MB PER MODEL GUIDANCE...COULD BRING OUR NEXT CHANCE FOR PRECIPITATION...ESPECIALLY ACROSS CENTRAL AND NORTHERN PORTIONS OF THE CWA. THIS IS A SOLUTION SUPPORTED BY QPF FIELDS FROM THE NAM AND OPERATIONAL GFS...AND TO A LESSER EXTENT THE EC. GIVEN THIS...OPTED TO GO AHEAD WITH 20-30% POPS ACROSS CENTRAL AND NORTHERN PORTIONS OF THE CWA EARLY TUESDAY MORNING THROUGH THE DAY TUESDAY. TUESDAY NIGHT AND BEYOND...AS PREVIOUSLY MENTIONED...INCREASING NORTHWESTERLY UPPER TROPOSPHERIC FLOW SHOULD DEVELOP OVER OUR AREA A THE WESTERN CONUS RIDGE STRENGTHENS...THUS INCREASING THE CHANCES FOR MULTIPLE SMALL-SCALE PERTURBATION TO CLEAR THE REGION. AS MENTIONED BY THE PREVIOUS SHIFT...CONFIDENCE WITH RESPECT TO THE REALIZATION OF PRECIPITATION ON ANY GIVEN DAY DURING THIS TIME PERIOD REMAINS LOW...BUT ITS HARD TO JUSTIFY A DRY FORECAST BASED ON MODEL GUIDANCE AND AS A RESULT...WENT AHEAD AND MAINTAINED POPS...GENERALLY IN THE 20-40% RANGE...ACROSS MUCH OF THE AREA TUESDAY NIGHT THROUGH SATURDAY. GUIDANCE SUGGESTS RESPECTABLE VALUES OF LOWER TROPOSPHERIC MOISTURE...WORKING IN CONCERT WITH VARYING LAPSE RATES WITH THE PASSAGE OF UPPER TROPOSPHERIC PERTURBATIONS...WILL PRESENT POTENTIAL ENERGY VALUES GENERALLY IN THE 1000-3000J/KG RANGE EACH DAY DURING THE LONG-TERM FORECAST PERIOD. DEEP-LAYER BULK SHEAR OF ~30KTS WILL ALSO BE POSSIBLE AS THE ENHANCED UPPER TROPOSPHERIC FLOW ESTABLISHES ITSELF OVER THE REGION. THAT SAID...FORECAST PROXIMITY SOUNDINGS FROM THE ACROSS THE CWA...PER THE NAM AND OPERATIONAL GFS...SUGGEST A HEALTHY LOWER TROPOSPHERIC CAPPING INVERSION WILL BE PRESENT EACH DAY AND WITH OMEGA REMAINING ON THE QUESTIONABLE SIDE...ITS HARD TO SAY THAT ANY ONE DAY HAS A GREATER CHANCE OF SEVERE WEATHER OVER THE NEXT. OBVIOUSLY...ANY DAY THAT CAN REALIZE CONVECTIVE INITIALIZATION WILL HAVE AT LEAST A CHANCE OF STRONG TO SEVERE THUNDERSTORM ACTIVITY...BUT CONFIDENCE IS NOT HIGH ENOUGH TO DEFINITIVELY MENTION SUCH CONDITIONS IN THE HWO. GIVEN THIS...FOR THE HWO...WILL SIMPLY STATE THAT SEVERE CONVECTION IS NOT OUT OF THE QUESTION DURING THE LONG-TERM FORECAST PERIOD...AND THE FORECAST WILL NEED TO BE MONITORED FOR THE POSSIBILITY OF SEVERE WEATHER DURING THE MIDDLE TO LATE PART OF NEXT WEEK. PRE-FRONTAL WARMING AHEAD OF A BOUNDARY-LAYER BAROCLINIC ZONE COULD PRESENT A VERY WARM DAY ON MONDAY..WITH GUIDANCE CURRENTLY SUGGESTING AFTERNOON TEMPERATURE READINGS COULD SPIKE TO AROUND 100 DEGREES MONDAY AFTERNOON ACROSS OUR SOUTHERN ZONES...AND MORE INTO THE 90S FARTHER NORTH ACROSS THE AREA. ITS IMPORTANT TO NOTE THAT FRONTAL POSITION WILL PLAY A CRUCIAL ROLE IN TEMPERATURE READINGS ON MONDAY AND THIS WILL NEED TO BE CLOSELY MONITORED. THE INFILTRATION OF A COOLER BOUNDARY-LAYER AIR MASS POST-FROPA SHOULD THEN ALLOW FOR HIGHS IN THE 80S AND LOW 90S TO FINISH THE FORECAST PERIOD. FINALLY...RESULTANT HEAT INDEX READINGS MONDAY AFTERNOON ARE EXPECTED TO CLIMB INTO THE 100-105 RANGE ACROSS OUR KANSAS COUNTIES AND AS A RESULT...WILL CONTINUE MENTIONING THIS IN THE HWO. && .AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1225 PM CDT SAT JUN 20 2015 SFC FRONTAL BOUNDARY CONTINUES TO PUSH E/SE AT THIS TIME...BUT HAS MOVED SOUTH OF THE TERMINAL AREAS. NORTHERLY WINDS HAVE BUILT IN BEHIND THE FRONT...AND ARE EXPECTED TO REMAIN THAT WAY THE REST OF THIS AFTERNOON...WITH GUSTS NEAR 20 MPH EXPECTED. LIGHTER WINDS ARE EXPECTED TONIGHT...GRADUALLY TURNING MORE EASTERLY THEN SOUTHEASTERLY WITH TIME. CURRENTLY HAVE THE TAF PERIOD DRY...CONFIDENCE IN ANY PRECIP CHANCES LATE IN THE PERIOD LOW ENOUGH TO KEEP ANY MENTION OUT FOR NOW. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...ADP LONG TERM...BRYANT AVIATION...ADP
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1236 PM CDT SAT JUN 20 2015 .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 337 AM CDT SAT JUN 20 2015 POTENTIAL FOR NIGHTLY DEVELOPMENT OF MESOSCALE CONVECTIVE SYSTEMS OVER THE WESTERN HIGH PLAINS TONIGHT AND SUNDAY NIGHT. MAIN UNCERTAINTY WILL BE THE ABILITY OF THESE STORM COMPLEXES TO OVERCOME MID LEVEL CAP IN PLACE ACROSS THE AREA. NORTHERN NEBRASKA WILL BE ON THE SOUTHERN EDGE OF MORE ACTIVE UPPER FLOW ACROSS THE NORTHERN PLAINS DURING THE PERIOD WITH PERIODIC INTRUSION OF FRONTAL BOUNDARIES TO THE SOUTHERN BORDER BEHIND THESE SYSTEMS TODAY THROUGH MONDAY. COLD FRONT LAGS BEHIND ONGOING COMPLEX OVER EASTERN SOUTH DAKOTA EARLY THIS MORNING WITH LATEST RAP MODEL BRINGING FRONT INTO NORTHEAST NEBRASKA BY MID MORNING. SOME SMALL CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS THROUGH THE MORNING ALONG THIS BOUNDARY BUT DRY CONDITIONS EXPECTED THIS AFTERNOON WITH THE FRONT AS IT TRACKS TOWARD FAR SOUTHEAST NEBRASKA REACHING THAT POSITION BY LATE AFTERNOON. SIMILAR PATTERN INDICATED TO DEVELOP TONIGHT AND AGAIN ON SUNDAY NIGHT. TEMPERATURES ALSO LOOK TO BE A CHALLENGE WITH THE VARIOUS STORM COMPLEXES MOVING THROUGH THE AREA AND TIMING AND LOCATION OF FRONTS AND BOUNDARIES. .LONG TERM...(MONDAY NIGHT THROUGH FRIDAY) ISSUED AT 337 AM CDT SAT JUN 20 2015 SAME GENERAL PATTERN EXTENDS INTO MOST OF THE EXTENDED PERIOD BEFORE PATTERN AMPILFIES BY FRIDAY WITH RIDGE BUILDING IN THE WEST AND TROUGH DEVELOPS IN THE EAST. && .AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1228 PM CDT SAT JUN 20 2015 VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD. A COLD FRONT WILL MOVE ACROSS THE KOMA AND KLNK SITES EARLY IN THE FORECAST PERIOD. PUT IN A QUICK TEMPO GROUP IN FOR EACH WITH 5SM -TSRA BETWEEN 19Z AND 20Z. CONFIDENCE NOT REAL HIGH AS CONVECTION THAT IS ATTEMPTING TO FIRE ALONG THE FRONT HAS TO BATTLE VERY WARM TEMPS ALOFT. AFTER THE COLD FRONT PASSES WINDS WILL SHIFT TO THE NORTHWEST AROUND 15G25KT THROUGH 00Z AT WHICH TIME THEY WILL DIMINISH TO BETWEEN 05KT TO 10KT. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...FOBERT LONG TERM...FOBERT AVIATION...MEYER
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
619 AM CDT SAT JUN 20 2015 .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 337 AM CDT SAT JUN 20 2015 POTENTIAL FOR NIGHTLY DEVELOPMENT OF MESOSCALE CONVECTIVE SYSTEMS OVER THE WESTERN HIGH PLAINS TONIGHT AND SUNDAY NIGHT. MAIN UNCERTAINTY WILL BE THE ABILITY OF THESE STORM COMPLEXES TO OVERCOME MID LEVEL CAP IN PLACE ACROSS THE AREA. NORTHERN NEBRASKA WILL BE ON THE SOUTHERN EDGE OF MORE ACTIVE UPPER FLOW ACROSS THE NORTHERN PLAINS DURING THE PERIOD WITH PERIODIC INTRUSION OF FRONTAL BOUNDARIES TO THE SOUTHERN BORDER BEHIND THESE SYSTEMS TODAY THROUGH MONDAY. COLD FRONT LAGS BEHIND ONGOING COMPLEX OVER EASTERN SOUTH DAKOTA EARLY THIS MORNING WITH LATEST RAP MODEL BRINGING FRONT INTO NORTHEAST NEBRASKA BY MID MORNING. SOME SMALL CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS THROUGH THE MORNING ALONG THIS BOUNDARY BUT DRY CONDITIONS EXPECTED THIS AFTERNOON WITH THE FRONT AS IT TRACKS TOWARD FAR SOUTHEAST NEBRASKA REACHING THAT POSITION BY LATE AFTERNOON. SIMILAR PATTERN INDICATED TO DEVELOP TONIGHT AND AGAIN ON SUNDAY NIGHT. TEMPERATURES ALSO LOOK TO BE A CHALLENGE WITH THE VARIOUS STORM COMPLEXES MOVING THROUGH THE AREA AND TIMING AND LOCATION OF FRONTS AND BOUNDARIES. .LONG TERM...(MONDAY NIGHT THROUGH FRIDAY) ISSUED AT 337 AM CDT SAT JUN 20 2015 SAME GENERAL PATTERN EXTENDS INTO MOST OF THE EXTENDED PERIOD BEFORE PATTERN AMPILFIES BY FRIDAY WITH RIDGE BUILDING IN THE WEST AND TROUGH DEVELOPS IN THE EAST. && .AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 614 AM CDT SAT JUN 20 2015 VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. COLD FRONT WILL MOVE THROUGH ALL 3 TAF SITES FROM LATE MORNING INTO THE EARLY AFTERNOON SWITCHING THE WINDS TO THE NORTHWEST FOR THE REST OF THE AFTN AND MOST OF THE EVNG. BEHIND THE COLD FRONT WE WILL SEE CU DEVELOPMENT AT FL040-050 AT ALL SITES WITH A PERIOD OF BKN POSSIBLE. WINDS WILL DIMINISH AND BECOMING NORTH TONIGHT WITH MOSTLY SKY CLEAR CONDITIONS. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...FOBERT LONG TERM...FOBERT AVIATION...
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
359 AM CDT SAT JUN 20 2015 .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 337 AM CDT SAT JUN 20 2015 POTENTIAL FOR NIGHTLY DEVELOPMENT OF MESOSCALE CONVECTIVE SYSTEMS OVER THE WESTERN HIGH PLAINS TONIGHT AND SUNDAY NIGHT. MAIN UNCERTAINTY WILL BE THE ABILITY OF THESE STORM COMPLEXES TO OVERCOME MID LEVEL CAP IN PLACE ACROSS THE AREA. NORTHERN NEBRASKA WILL BE ON THE SOUTHERN EDGE OF MORE ACTIVE UPPER FLOW ACROSS THE NORTHERN PLAINS DURING THE PERIOD WITH PERIODIC INTRUSION OF FRONTAL BOUNDARIES TO THE SOUTHERN BORDER BEHIND THESE SYSTEMS TODAY THROUGH MONDAY. COLD FRONT LAGS BEHIND ONGOING COMPLEX OVER EASTERN SOUTH DAKOTA EARLY THIS MORNING WITH LATEST RAP MODEL BRINGING FRONT INTO NORTHEAST NEBRASKA BY MID MORNING. SOME SMALL CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS THROUGH THE MORNING ALONG THIS BOUNDARY BUT DRY CONDITIONS EXPECTED THIS AFTERNOON WITH THE FRONT AS IT TRACKS TOWARD FAR SOUTHEAST NEBRASKA REACHING THAT POSITION BY LATE AFTERNOON. SIMILAR PATTERN INDICATED TO DEVELOP TONIGHT AND AGAIN ON SUNDAY NIGHT. TEMPERATURES ALSO LOOK TO BE A CHALLENGE WITH THE VARIOUS STORM COMPLEXES MOVING THROUGH THE AREA AND TIMING AND LOCATION OF FRONTS AND BOUNDARIES. .LONG TERM...(MONDAY NIGHT THROUGH FRIDAY) ISSUED AT 337 AM CDT SAT JUN 20 2015 SAME GENERAL PATTERN EXTENDS INTO MOST OF THE EXTENDED PERIOD BEFORE PATTERN AMPILFIES BY FRIDAY WITH RIDGE BUILDING IN THE WEST AND TROUGH DEVELOPS IN THE EAST. && .AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1144 PM CDT FRI JUN 19 2015 VFR CONDITIONS ARE FORECAST THROUGH THE TAF PERIOD. LINE OF THUNDERSTORMS MOVING INTO CENTRAL SOUTH DAKOTA COULD ROLL INTO NORTHEAST NEBRASKA BETWEEN 09Z AND 12Z...BUT SHOULD STAY NORTH OF KOFK. HOWEVER THERE IS A SMALL CHANCE MVFR CIGS/VSBYS COULD AFFECT KOFK BRIEFLY. OTHERWISE SOUTH TO SOUTHEAST WINDS 15 TO 25KT WILL CONTINUE OVERNIGHT UNTIL A COOL FRONT SLIPS INTO EASTERN NEBRASKA BETWEEN 15Z AND 21Z...TURNING WINDS TO THE NORTHWEST AT ALL TAF SITES. LOW LEVEL WIND SHEAR IS ALSO EXPECTED THROUGH 14Z WITH 50KT SOUTHWEST WINDS NEAR FL015-FL020 OVERRIDING SOUTHEAST SURFACE FLOW. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...FOBERT LONG TERM...FOBERT AVIATION...DERGAN
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
1150 PM PDT FRI JUN 19 2015 .SYNOPSIS...HIGH PRESSURE WILL RESULT IN CONTINUED HOT AND DRY CONDITIONS AND BREEZY AFTERNOONS THROUGH EARLY NEXT WEEK. THE HOTTEST TEMPERATURES ARE EXPECTED SATURDAY AND SUNDAY. && .UPDATE...THICKER SMOKE HAS WORKED ITS WAY INTO THE BISHOP AREA TONIGHT. VISIBILITY AT THE BISHOP AIRPORT HAS BEEN UP AND DOWN BETWEEN 1.75 AND 6 MILES OVER THE LAST HOUR. THE CALIFORNIA HIGHWAY PATROL IS NOT AWARE OF ANY NEW FIRES IN THE AREA THUS IT IS BELIEVED THIS LOW LEVEL SMOKE IS FROM THE SKY FIRE SOUTH OF YOSEMITE. THE CURRENT 700-500MB FLOW WOULD FAVOR TRANSPORT OVER THE SIERRA...AND OVERNIGHT DRAINAGE WINDS ARE LIKELY FUNNELING THE SMOKE INTO THE OWENS VALLEY. HAVE UPDATED THE WX GRIDS TO BRING A MENTION OF SMOKE TO THAT AREA AS WELL AS IN THE MORONGO VALLEY AREA WHERE SMOKE FROM THE LAKE FIRE IS EXPECTED TO CONTINUE. && .AVIATION...FOR MCCARRAN...HOT TEMPERATURES WILL CONTINUE WITH GUSTY SOUTHWESTERLY WINDS DURING THE LATE AFTERNOON AND EVENING. SMOKE FROM CALIFORNIA WILDFIRES SHOULD STAY CLEAR OF THE AREA THIS MORNING...BUT MAY BEGIN TO DRIFT TOWARD THE VALLEY BY THIS AFTERNOON/EVENING. OUTSIDE OF WINDS AND TEMPERATURES...NO OPERATIONALLY SIGNIFICANT WEATHER IS EXPECTED THIS WEEKEND. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...HOT TEMPERATURES WILL BRING HIGH DENSITY ALTITUDES THROUGH THE WEEKEND. TYPICAL AFTERNOON BREEZES CAN BE EXPECTED WITH THE STRONGEST WINDS LATE THIS AFTERNOON INTO THIS EVENING. SMOKE FROM WILDFIRES BURNING IN THE SIERRA AND SAN BERNARDINO MOUNTAINS COULD CREATE VISIBILITY ISSUES AT BETWEEN THE SURFACE AND 20KFT TO THE EAST OF THE FIRE LOCATIONS. AS OF 645Z SMOKE WAS BEGINNING TO IMPACT KBIH...WHERE VISIBILITY WAS OSCILLATING BETWEEN 1.75 AND 6 MILES. SMOKE SHOULD BEGIN TO THIN AFTER SUNRISE...IF NOT BEFORE. && .PREV UPDATE...920 PM...NUDGED WINDS CLOSERS TO THE HRRR GUIDANCE WHICH SEEMS TO HAVE THE BEST HANDLE ON THE CURRENT SITUATION. OTHERWISE NO SIGNIFICANT CHANGES THROUGH TONIGHT. && .PREV DISCUSSION... 240 PM PDT FRI JUN 19 2015 .SHORT TERM...TONIGHT THROUGH MONDAY HIGH PRESSURE CONTINUES TO ENCOMPASS ALL OF THE SOUTHERN CONUS INCLUDING THE DESERT SOUTHWEST. THIS WILL ALLOW TEMPERATURES TO REMAIN WELL ABOVE NORMAL BUT SHORT OF RECORD LEVELS. HIGH TEMPERATURES FOR THE WEEKEND WILL BE A COUPLE DEGREES WARMER THAN TODAY BUT WE SHOULD SEE SLIGHTLY LESS HOT TEMPERATURES EARLY NEXT WEEK. BREEZY SOUTHERLY WINDS WILL ACCOMPANY THE HEAT IN THE AFTERNOONS. AS THE WILDFIRE SEASON GETS UNDERWAY...SMOKE COULD AFFECT SOME AREAS OF THE CWA. IN PARTICULAR...THE LAKE FIRE WILL BRING SMOKE TO THE MORONGO BASIN AND BE VISIBLE FROM MUCH OF SOUTHERN SAN BERNARDINO AND MOHAVE COUNTIES. .LONG TERM...TUESDAY THROUGH FRIDAY A DRY AND HOT PERIOD IS FORECAST THROUGH MUCH OF NEXT WEEK WITH TEMPERATURES REMAINING WELL ABOVE NORMAL. AN INCREASE IN CLOUDS AND AN UPTICK IN HUMIDITY IS POSSIBLE LATER IN THE WEEK AS AN INVERTED TROUGH MOVES WEST ALONG NORTHERN MEXICO AND WEAK LOW PRESSURE SETS UP JUST OFF THE BAJA WEST COAST. 12Z MOS GUIDANCE CAME IN WARMER WITH EXTENDED TEMPS AT KLAS BETWEEN 107-109 DEGREES OR 6-8 DEGREES ABOVE NORMAL WITH NO DROPOFF LATE IN THE WEEK AS INDICATED BY EARLIER GUIDANCE. THE LARGE SCALE PATTERN SHOWS QUITE A FEW POSSIBLE FEATURES IN PLAY DURING THIS TIME FRAME SO OVERALL CONFIDENCE IS LOW IN ANY ACTUAL OUTCOME. CLIMATOLOGICALLY SPEAKING, A HOTTER...DRIER PATTERN IS FAVORED SO THE FORECAST WAS TRENDED THAT WAY BUT IF LATER MODEL FORECASTS CONTINUE TO SHOW HIGH PRESSURE STRENGTHENING OVER THE FOUR CORNERS AND A PERSISTENT SOUTH TO SOUTHEAST FLOW SETTING UP, A SERIOUS LOOK WILL NEED TO TAKEN ON WHAT THAT WOULD MEAN FOR OUR FORECAST AREA. && .SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. && $$ UPDATES/AVIATION...WOLCOTT PREV DISCUSSION....BERC/SALMEN FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE: HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
920 PM PDT FRI JUN 19 2015 .SYNOPSIS...HIGH PRESSURE WILL RESULT IN CONTINUED HOT AND DRY CONDITIONS AND BREEZY AFTERNOONS THROUGH EARLY NEXT WEEK. THE HOTTEST TEMPERATURES ARE EXPECTED SATURDAY AND SUNDAY. && .UPDATE...NUDGED WINDS CLOSERS TO THE HRRR GUIDANCE WHICH SEEMS TO HAVE THE BEST HANDLE ON THE CURRENT SITUATION. OTHERWISE NO SIGNIFICANT CHANGES THROUGH TONIGHT. NO FURTHER UPDATES PLANNED THIS EVENING. && .PREV DISCUSSION... 240 PM PDT FRI JUN 19 2015 .SHORT TERM...TONIGHT THROUGH MONDAY HIGH PRESSURE CONTINUES TO ENCOMPASS ALL OF THE SOUTHERN CONUS INCLUDING THE DESERT SOUTHWEST. THIS WILL ALLOW TEMPERATURES TO REMAIN WELL ABOVE NORMAL BUT SHORT OF RECORD LEVELS. HIGH TEMPERATURES FOR THE WEEKEND WILL BE A COUPLE DEGREES WARMER THAN TODAY BUT WE SHOULD SEE SLIGHTLY LESS HOT TEMPERATURES EARLY NEXT WEEK. BREEZY SOUTHERLY WINDS WILL ACCOMPANY THE HEAT IN THE AFTERNOONS. AS THE WILDFIRE SEASON GETS UNDERWAY...SMOKE COULD AFFECT SOME AREAS OF THE CWA. IN PARTICULAR...THE LAKE FIRE WILL BRING SMOKE TO THE MORONGO BASIN AND BE VISIBLE FROM MUCH OF SOUTHERN SAN BERNARDINO AND MOHAVE COUNTIES. .LONG TERM...TUESDAY THROUGH FRIDAY A DRY AND HOT PERIOD IS FORECAST THROUGH MUCH OF NEXT WEEK WITH TEMPERATURES REMAINING WELL ABOVE NORMAL. AN INCREASE IN CLOUDS AND AN UPTICK IN HUMIDITY IS POSSIBLE LATER IN THE WEEK AS AN INVERTED TROUGH MOVES WEST ALONG NORTHERN MEXICO AND WEAK LOW PRESSURE SETS UP JUST OFF THE BAJA WEST COAST. 12Z MOS GUIDANCE CAME IN WARMER WITH EXTENDED TEMPS AT KLAS BETWEEN 107-109 DEGREES OR 6-8 DEGREES ABOVE NORMAL WITH NO DROPOFF LATE IN THE WEEK AS INDICATED BY EARLIER GUIDANCE. THE LARGE SCALE PATTERN SHOWS QUITE A FEW POSSIBLE FEATURES IN PLAY DURING THIS TIME FRAME SO OVERALL CONFIDENCE IS LOW IN ANY ACTUAL OUTCOME. CLIMATOLOGICALLY SPEAKING, A HOTTER...DRIER PATTERN IS FAVORED SO THE FORECAST WAS TRENDED THAT WAY BUT IF LATER MODEL FORECASTS CONTINUE TO SHOW HIGH PRESSURE STRENGTHENING OVER THE FOUR CORNERS AND A PERSISTENT SOUTH TO SOUTHEAST FLOW SETTING UP, A SERIOUS LOOK WILL NEED TO TAKEN ON WHAT THAT WOULD MEAN FOR OUR FORECAST AREA. && .AVIATION...FOR MCCARRAN...HOT TEMPERATURES WILL CONTINUE WITH GUSTY SOUTHWESTERLY WINDS DURING THE LATE AFTERNOON AND EVENING. SMOKE FROM CALIFORNIA WILDFIRES SHOULD STAY CLEAR OF THE AREA TODAY. OUTSIDE OF WINDS AND TEMPERATURES...NO OPERATIONALLY SIGNIFICANT WEATHER IS EXPECTED THIS WEEKEND. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...HOT TEMPERATURES WILL BRING HIGH DENSITY ALTITUDES THROUGH THE WEEKEND. TYPICAL AFTERNOON BREEZES CAN BE EXPECTED WITH THE STRONGEST WINDS LATE THIS AFTERNOON INTO THIS EVENING. ELEVATED SMOKE FROM WILDFIRES BURNING IN THE SIERRA AND SAN BERNARDINO MOUNTAINS COULD CREATE VISIBILITY ISSUES AT ALTITUDE TO THE EAST OF THE FIRE LOCATIONS. && .SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. && $$ UPDATE...WOLCOTT PREV DISCUSSION...BERC/SALMEN FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE: HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS RALEIGH NC
740 AM EDT FRI JUN 19 2015 .SYNOPSIS... A PERSISTENT UPPER-LEVEL RIDGE OF HIGH PRESSURE ACROSS THE SOUTHEAST U.S. WILL WEAKEN THROUGH OVER THE WEEKEND AS THE REMNANTS OF TROPICAL STORM BILL APPROACHES THE REGION FROM THE WEST. THE RIDGE WILL STRENGTHEN AGAIN NEXT WEEK AS A STATIONARY FRONT LINGERS ACROSS THE OHIO VALLEY AND THE VIRGINIAS. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 345 AM FRIDAY... A FEW LINGERING SHOWERS ARE POSSIBLE THROUGH AROUND DAYBREAK ACROSS THE COASTAL PLAIN. OTHERWISE EXPECT PARTLY TO MOSTLY CLEAR SKIES WITH A VEIL OF HIGHS CLOUDS TO START THE DAY. MANY OF THE SAME WEATHER FEATURES THAT HAVE BEEN AROUND FOR THE PAST DAY OR TWO ARE STILL PRESENT TODAY. THE PERSISTENT SOUTHEAST RIDGE SHIFTS SOUTH TODAY AND HEIGHTS FALL A BIT RESULTING IN MAXES TODAY THAT ARE A COUPLE OF DEGREES COOLER THAN THURSDAY. HIGHS SHOULD RANGE FROM 91 IN THE TRIAD TO 98 NEAR THE SC BORDER. A HEAT ADVISORY WILL ONCE AGAIN BE IN EFFECT FOR THE SOUTHERN AND CENTRAL COASTAL PLAIN...THE SANDHILLS AND THE SOUTHEAST PIEDMONT. HEAT INDEX VALUES IN THESE AREAS WILL RANGE FROM 101 TO 105 AGAIN TODAY MAKING IT THE 3RD OR 4TH DAY THIS WEEK WITH SUCH HIGH HEAT INDEX VALUES. EXPECT CONVECTION TO FIRE ONCE AGAIN THIS AFTERNOON WITH A FOCUS INITIALLY ACROSS THE FOOTHILLS AND WESTERN PIEDMONT IN A REGION OF WEAK TO MODERATE INSTABILITY WITH MODEST BULK SHEAR VALUES. ADDITIONAL CONVECTION IS LIKELY TO DEVELOP IN THE SANDHILLS AND SOUTHERN COASTAL PLAIN IN A REGION OF MODERATE TO EVEN STRONG INSTABILITY AND RAP PROGGED DCAPE VALUES GREATER THAN 1300 J/KG. SIMILAR TO THURSDAY...THE MAIN SEVERE WEATHER THREAT WILL BE FROM LOW END ORGANIZED OR MULTICELL STORMS PRODUCING DOWNBURST WINDS. -BLAES && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... AS OF 345 AM EDT FRIDAY... CONVECTION IS LIKELY TO BE ONGOING TONIGHT AT THE START OF THE SHORT TERM PERIOD. THE CONVECTION WILL SHIFT EASTWARD WITH TIME AND DEMONSTRATE A SLOW WEAKENING LATE IN THE EVENING AND DURING THE OVERNIGHT HOURS. LOWS SHOULD RANGE IN THE 60 TO 75 RANGE. THE REMNANTS OF BILL WILL MOVE FROM THE MID-MISSISSIPPI VALLEY TOWARD THE SOUTHERN APPALACHIANS ON SATURDAY. AN INCREASE IN CLOUD COVER AND THE WEAKENING RIDGE WILL RESULT IN MAX TEMPERATURES SIMILAR OR JUST A NUDGE COOLER THAN FRIDAY. SCATTERED CONVECTION IS ONCE AGAIN EXPECTED ON SATURDAY AFTERNOON... MOST FAVORED ACROSS THE WESTERN AND NORTHERN PIEDMONT IN PROXIMITY TO THE APPROACHING UPPER TROUGH AND DEEP MOISTURE. -BLAES && ..LONG TERM/SATURDAY NIGHT THROUGH THURSDAY/... AS OF 350 AM FRIDAY... SATURDAY NIGHT THROUGH SUNDAY NIGHT: REMNANTS OF TC BILL...PROGGED TO BE INVOF THE LOWER MS/TN VALLEY REGION SATURDAY MORNING WILL FINALLY GET PICKED BY THE MAIN BELT OF WESTERLIES ON SATURDAY AND WILL GET SWEPT EASTWARD THROUGH THE REGION...SHEARING ALONG THE WAY INTO A COMPACT OPEN TROUGH AS IT CROSSES THE MID-ATLANTIC STATES SATURDAY NIGHT/EARLY SUNDAY. NOT QUITE THE MOST FAVORABLE DIURNAL TIMING AS THE BOUNDARY LAYER WILL STABILIZE OVERNIGHT...BUT THERE WILL BE COPIOUS CAPE ABOVE THE INVERSION THAT WILL HELP CONVECTION TO SUSTAIN OVERNIGHT AS PWATS INCREASE TO ~2.0". EXPECT POPS TO INCREASE LATE SATURDAY AFTERNOON/EARLY EVENING FROM THE WEST AND SPREAD EAST OVERNIGHT/EARLY SUNDAY MORNING. HAVE BUMPED UP POPS TO LOW LIKELY/HIGH CHANCE ACROSS THE NORTHERN TIER IN PROXIMITY TO THE BETTER FORCING...TO SMALL CHANCES ACROSS THE SOUTH. RAIN SHOULD BE IN THE PROCESS OF EXITING THE COASTAL PLAIN BY MID MORNING WITH FCST SOUNDINGS SHOWING PRONOUNCED SUBSIDENCE/WARMING ALOFT IN THE WAKE OF THE EXITING TROUGH THAT WILL SUPPRESS CONVECTION SUNDAY AFTERNOON . WHILE ANY LINGERING MORNING CONVECTION AND ASSOCIATED CLOUDINESS MAY RESULT IN A SLUGGISH WARM-UP...FULL SUN DURING THE AFTERNOON WILL SEND TEMPERATURES SOARING TO WHAT WE HAVE COME ACCUSTOM TO LATELY. HIGHS TO THE MID 90S NORTH AND UPPER 90S SOUTH. LOWS IN THE LOWER TO MID 70S. MONDAY THROUGH THURSDAY: ZONAL FLOW ON MONDAY WILL QUICKLY VEER TO NORTHWESTERLY AS AN UPPER RIDGE AMPLIFIES IN THE MIDWEST AND MIGRATES EAST THROUGH THURSDAY. NO RELIEF FROM THE HEAT IS IN SIGHT FOR THE UPCOMING WORK WEEK WITH PROJECTED LOW-LEVEL THICKNESSES 1440-1450 METERS WHILE H8 TEMPERATURES ARE EXPECTED TO HOVER BETWEEN 20 TO 22C...WHICH WILL EASILY SUPPORT HIGHS EACH DAY IN THE MID 90S NW TO LOWER 100-102 ACROSS THE SOUTH/SOUTHEAST. THESE HOT TEMPERATURES COMBINED WITH DEWPOINTS IN THE UPPER 60S TO LOWER 70S WILL RESULT IN A A PROLONGED 4 TO 5 CONSECUTIVE DAY STRETCH OF HEAT INDICES OF 102 TO 105 RANGE ACROSS THE EASTERN TWO-THIRDS OF THE FORECAST AREA...WHICH WILL LIKELY WARRANT FUTURE HEAT ADVISORIES FOR MUCH OF THE UPCOMING WORK WEEK. STRONG ADIABATIC HEATING WILL SUPPORT SLIGHT TO LOW CHANCE OF CONVECTION EACH DAY...WITH BEST RAIN CHANCES IN THE FAR WEST ALONG THE HIGHER TERRAIN...AND ALONG COASTAL SECTIONS WITH INLAND PENETRATION OF SEABREEZE. DISTURBANCES IN THE AFOREMENTIONED NW FLOW ALOFT COULD PROVIDE HIGHER/MORE WIDESPREAD RAIN CHANCES...WILL WOULD GREATLY OFFER SOME RELIEF FROM THE HEAT(FINGERS CROSSED)...HOWEVER MODEL CONFIDENCE IN SUCH MESOSCALE FEATURES THIS FAR OUT IS TOO LOW AT THIS TIME. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... AS OF 740 AM THURSDAY... EVENING AND OVERNIGHT CONVECTION HAS DIMINISHED TO JUST A ROGUE SHOWER OR TWO NOTED AT DAYBREAK WITH AN AREA OF SCT-BKN MID CLOUDS ACROSS THE COASTAL PLAIN AND EASTERN PIEDMONT. A FEW NON TAF SITE LOCATIONS WERE REPORTING SOME MVFR CIGS AND VSBYS. GENERALLY FAIR WEATHER IS EXPECTED DURING THE MORNING HOURS TODAY WITH A VEIL OF HIGH CIRRUS. DIURNAL CUMULUS WILL DEVELOP DURING THE LATE MORNING WITH ANOTHER STORMY LATE AFTERNOON AND EVENING EXPECTED. THUNDERSTORMS WILL INITIALLY BE MOST NUMEROUS ACROSS THE TRIAD AREA AND TRANSITION EASTWARD AS ADDITIONAL CONVECTION DEVELOPS IN THE SANDHILLS AND SOUTHERN PIEDMONT. THE CONVECTION WILL GENERALLY DECREASE IN COVERAGE AND INTENSITY LATE IN THE EVENING...ALTHOUGH SOME PRECIPITATION WILL PERSIST IN THE EARLY MORNING HOURS ON SATURDAY. THE SURFACE PRESSURE FIELD WILL REMAIN WEAK TODAY RESULTING IN GENERALLY LIGHT AND VARIABLE WINDS FROM THE SOUTHWEST THAT SHOULD VEER AROUND TO MORE NORTHERLY LATER TODAY. LOOKING BEYOND THE 24 HOUR TAF PERIOD...VFR CONDITIONS ARE GENERALLY EXPECTED FOR MUCH OF THE PERIOD ALTHOUGH ANOTHER ROUND OF SCATTERED AFTERNOON AND EVENING CONVECTION IS EXPECTED ON SATURDAY. SUNDAY MAY FEATURE A LULL IN THE PRECIPITATION COVERAGE BEFORE MORE AFTERNOON AND EVENING STORMS ARRIVE FOR MONDAY AND TUESDAY. -BLAES && .CLIMATE... REC REC HI DAY MAX YR MIN YR RDU RECORDS 06/19 102 1944 73 2010 06/20 102 1887 77 1924 06/21 101 1933 75 1933 GSO RECORDS 06/19 100 1944 77 1970 06/20 100 1924 75 2009 06/21 100 1933 75 1924 FAY RECORDS 06/19 102 1944 75 1948 06/20 102 1970 77 2009 06/21 105 1933 74 1999 && .RAH WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY FROM NOON TODAY TO 7 PM EDT THIS EVENING FOR NCZ042-043-077-078-085-086-088-089. && $$ SYNOPSIS...BLAES NEAR TERM...BLAES SHORT TERM...BLAES LONG TERM...CBL AVIATION...BLAES CLIMATE...RAH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
350 AM EDT FRI JUN 19 2015 .SYNOPSIS... A PERSISTENT UPPER-LEVEL RIDGE OF HIGH PRESSURE ACROSS THE SOUTHEAST U.S. WILL WEAKEN THROUGH OVER THE WEEKEND AS THE REMNANTS OF TROPICAL STORM BILL APPROACHES THE REGION FROM THE WEST. THE RIDGE WILL STRENGTHEN AGAIN NEXT WEEK AS A STATIONARY FRONT LINGERS ACROSS THE OHIO VALLEY AND THE VIRGINIAS. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 345 AM FRIDAY... A FEW LINGERING SHOWERS ARE POSSIBLE THROUGH AROUND DAYBREAK ACROSS THE COASTAL PLAIN. OTHERWISE EXPECT PARTLY TO MOSTLY CLEAR SKIES WITH A VEIL OF HIGHS CLOUDS TO START THE DAY. MANY OF THE SAME WEATHER FEATURES THAT HAVE BEEN AROUND FOR THE PAST DAY OR TWO ARE STILL PRESENT TODAY. THE PERSISTENT SOUTHEAST RIDGE SHIFTS SOUTH TODAY AND HEIGHTS FALL A BIT RESULTING IN MAXES TODAY THAT ARE A COUPLE OF DEGREES COOLER THAN THURSDAY. HIGHS SHOULD RANGE FROM 91 IN THE TRIAD TO 98 NEAR THE SC BORDER. A HEAT ADVISORY WILL ONCE AGAIN BE IN EFFECT FOR THE SOUTHERN AND CENTRAL COASTAL PLAIN...THE SANDHILLS AND THE SOUTHEAST PIEDMONT. HEAT INDEX VALUES IN THESE AREAS WILL RANGE FROM 101 TO 105 AGAIN TODAY MAKING IT THE 3RD OR 4TH DAY THIS WEEK WITH SUCH HIGH HEAT INDEX VALUES. EXPECT CONVECTION TO FIRE ONCE AGAIN THIS AFTERNOON WITH A FOCUS INITIALLY ACROSS THE FOOTHILLS AND WESTERN PIEDMONT IN A REGION OF WEAK TO MODERATE INSTABILITY WITH MODEST BULK SHEAR VALUES. ADDITIONAL CONVECTION IS LIKELY TO DEVELOP IN THE SANDHILLS AND SOUTHERN COASTAL PLAIN IN A REGION OF MODERATE TO EVEN STRONG INSTABILITY AND RAP PROGGED DCAPE VALUES GREATER THAN 1300 J/KG. SIMILAR TO THURSDAY...THE MAIN SEVERE WEATHER THREAT WILL BE FROM LOW END ORGANIZED OR MULTICELL STORMS PRODUCING DOWNBURST WINDS. -BLAES && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... AS OF 345 AM EDT FRIDAY... CONVECTION IS LIKELY TO BE ONGOING TONIGHT AT THE START OF THE SHORT TERM PERIOD. THE CONVECTION WILL SHIFT EASTWARD WITH TIME AND DEMONSTRATE A SLOW WEAKENING LATE IN THE EVENING AND DURING THE OVERNIGHT HOURS. LOWS SHOULD RANGE IN THE 60 TO 75 RANGE. THE REMNANTS OF BILL WILL MOVE FROM THE MID-MISSISSIPPI VALLEY TOWARD THE SOUTHERN APPALACHIANS ON SATURDAY. AN INCREASE IN CLOUD COVER AND THE WEAKENING RIDGE WILL RESULT IN MAX TEMPERATURES SIMILAR OR JUST A NUDGE COOLER THAN FRIDAY. SCATTERED CONVECTION IS ONCE AGAIN EXPECTED ON SATURDAY AFTERNOON... MOST FAVORED ACROSS THE WESTERN AND NORTHERN PIEDMONT IN PROXIMITY TO THE APPROACHING UPPER TROUGH AND DEEP MOISTURE. -BLAES && ..LONG TERM/SATURDAY NIGHT THROUGH THURSDAY/... AS OF 350 AM FRIDAY... SATURDAY NIGHT THROUGH SUNDAY NIGHT: REMNANTS OF TC BILL...PROGGED TO BE INVOF THE LOWER MS/TN VALLEY REGION SATURDAY MORNING WILL FINALLY GET PICKED BY THE MAIN BELT OF WESTERLIES ON SATURDAY AND WILL GET SWEPT EASTWARD THROUGH THE REGION...SHEARING ALONG THE WAY INTO A COMPACT OPEN TROUGH AS IT CROSSES THE MID-ATLANTIC STATES SATURDAY NIGHT/EARLY SUNDAY. NOT QUITE THE MOST FAVORABLE DIURNAL TIMING AS THE BOUNDARY LAYER WILL STABILIZE OVERNIGHT...BUT THERE WILL BE COPIOUS CAPE ABOVE THE INVERSION THAT WILL HELP CONVECTION TO SUSTAIN OVERNIGHT AS PWATS INCREASE TO ~2.0". EXPECT POPS TO INCREASE LATE SATURDAY AFTERNOON/EARLY EVENING FROM THE WEST AND SPREAD EAST OVERNIGHT/EARLY SUNDAY MORNING. HAVE BUMPED UP POPS TO LOW LIKELY/HIGH CHANCE ACROSS THE NORTHERN TIER IN PROXIMITY TO THE BETTER FORCING...TO SMALL CHANCES ACROSS THE SOUTH. RAIN SHOULD BE IN THE PROCESS OF EXITING THE COASTAL PLAIN BY MID MORNING WITH FCST SOUNDINGS SHOWING PRONOUNCED SUBSIDENCE/WARMING ALOFT IN THE WAKE OF THE EXITING TROUGH THAT WILL SUPPRESS CONVECTION SUNDAY AFTERNOON . WHILE ANY LINGERING MORNING CONVECTION AND ASSOCIATED CLOUDINESS MAY RESULT IN A SLUGGISH WARM-UP...FULL SUN DURING THE AFTERNOON WILL SEND TEMPERATURES SOARING TO WHAT WE HAVE COME ACCUSTOM TO LATELY. HIGHS TO THE MID 90S NORTH AND UPPER 90S SOUTH. LOWS IN THE LOWER TO MID 70S. MONDAY THROUGH THURSDAY: ZONAL FLOW ON MONDAY WILL QUICKLY VEER TO NORTHWESTERLY AS AN UPPER RIDGE AMPLIFIES IN THE MIDWEST AND MIGRATES EAST THROUGH THURSDAY. NO RELIEF FROM THE HEAT IS IN SIGHT FOR THE UPCOMING WORK WEEK WITH PROJECTED LOW-LEVEL THICKNESSES 1440-1450 METERS WHILE H8 TEMPERATURES ARE EXPECTED TO HOVER BETWEEN 20 TO 22C...WHICH WILL EASILY SUPPORT HIGHS EACH DAY IN THE MID 90S NW TO LOWER 100-102 ACROSS THE SOUTH/SOUTHEAST. THESE HOT TEMPERATURES COMBINED WITH DEWPOINTS IN THE UPPER 60S TO LOWER 70S WILL RESULT IN A A PROLONGED 4 TO 5 CONSECUTIVE DAY STRETCH OF HEAT INDICES OF 102 TO 105 RANGE ACROSS THE EASTERN TWO-THIRDS OF THE FORECAST AREA...WHICH WILL LIKELY WARRANT FUTURE HEAT ADVISORIES FOR MUCH OF THE UPCOMING WORK WEEK. STRONG ADIABATIC HEATING WILL SUPPORT SLIGHT TO LOW CHANCE OF CONVECTION EACH DAY...WITH BEST RAIN CHANCES IN THE FAR WEST ALONG THE HIGHER TERRAIN...AND ALONG COASTAL SECTIONS WITH INLAND PENETRATION OF SEABREEZE. DISTURBANCES IN THE AFOREMENTIONED NW FLOW ALOFT COULD PROVIDE HIGHER/MORE WIDESPREAD RAIN CHANCES...WILL WOULD GREATLY OFFER SOME RELIEF FROM THE HEAT(FINGERS CROSSED)...HOWEVER MODEL CONFIDENCE IN SUCH MESOSCALE FEATURES THIS FAR OUT IS TOO LOW AT THIS TIME. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... AS OF 245 AM THURSDAY... A LINGERING ARC OF SCATTERED SHOWERS AND STORMS WILL MOVE EASTWARD ACROSS CENTRAL NC AND GRADUALLY WEAKEN DURING THE PREDAWN HOURS. OUTSIDE OF THIS CONVECTION WITH ITS ASSOCIATED LOCAL VSBY AND CIG RESTRICTIONS... MOST OF CENTRAL NC SHOULD EXPERIENCE VFR CONDITIONS DURING THE MORNING HOURS. A BRIEF PERIOD OF FOG OR SHALLOW STRATUS IS POSSIBLE BEFORE DAYBREAK AS SKIES CLEAR AND WINDS RELAX. GENERALLY FAIR WEATHER IS EXPECTED DURING THE MORNING HOURS WITH A VEIL OF HIGH CLOUDS. DIURNAL CUMULUS WILL DEVELOP DURING THE LATE MORNING WITH ANOTHER STORMY LATE AFTERNOON AND EVENING EXPECTED. THE STORMS WILL INITIALLY BE MOST NUMEROUS ACROSS THE TRIAD AREA AND TRANSITION EASTWARD AS ADDITIONAL CONVECTION DEVELOPS IN THE SANDHILLS AND SOUTHERN PIEDMONT. THE CONVECTION WILL GENERALLY DECREASE IN COVERAGE AND INTENSITY LATE IN THE EVENING ALTHOUGH SOME PRECIPITATION WILL PERSIST IN THE EARLY MORNING HOURS ON SATURDAY. LOOKING BEYOND THE 24 HOUR TAF PERIOD...VFR CONDITIONS ARE GENERALLY EXPECTED FOR MUCH OF THE PERIOD ALTHOUGH ANOTHER ROUND OF SCATTERED AFTERNOON AND EVENING CONVECTION IS EXPECTED ON SATURDAY. SUNDAY MAY FEATURE A LULL IN THE PRECIPITATION COVERAGE BEFORE MORE AFTERNOON AND EVENING STORMS ARRIVE FOR MONDAY AND TUESDAY. -BLAES && .CLIMATE... REC REC HI DAY MAX YR MIN YR RDU RECORDS 06/19 102 1944 73 2010 06/20 102 1887 77 1924 06/21 101 1933 75 1933 GSO RECORDS 06/19 100 1944 77 1970 06/20 100 1924 75 2009 06/21 100 1933 75 1924 FAY RECORDS 06/19 102 1944 75 1948 06/20 102 1970 77 2009 06/21 105 1933 74 1999 && .RAH WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY FROM NOON TODAY TO 7 PM EDT THIS EVENING FOR NCZ042-043-077-078-085-086-088-089. && $$ SYNOPSIS...BLAES NEAR TERM...BLAES SHORT TERM...BLAES LONG TERM...CBL AVIATION...BLAES CLIMATE...RAH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
346 AM EDT FRI JUN 19 2015 .SYNOPSIS... A PERSISTENT UPPER-LEVEL RIDGE OF HIGH PRESSURE ACROSS THE SOUTHEAST U.S. WILL WEAKEN THROUGH OVER THE WEEKEND AS THE REMNANTS OF TROPICAL STORM BILL APPROACHES THE REGION FROM THE WEST. THE RIDGE WILL STRENGTHEN AGAIN NEXT WEEK AS A STATIONARY FRONT LINGERS ACROSS THE OHIO VALLEY AND THE VIRGINIAS. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 345 AM FRIDAY... A FEW LINGERING SHOWERS ARE POSSIBLE THROUGH AROUND DAYBREAK ACROSS THE COASTAL PLAIN. OTHERWISE EXPECT PARTLY TO MOSTLY CLEAR SKIES WITH A VEIL OF HIGHS CLOUDS TO START THE DAY. MANY OF THE SAME WEATHER FEATURES THAT HAVE BEEN AROUND FOR THE PAST DAY OR TWO ARE STILL PRESENT TODAY. THE PERSISTENT SOUTHEAST RIDGE SHIFTS SOUTH TODAY AND HEIGHTS FALL A BIT RESULTING IN MAXES TODAY THAT ARE A COUPLE OF DEGREES COOLER THAN THURSDAY. HIGHS SHOULD RANGE FROM 91 IN THE TRIAD TO 98 NEAR THE SC BORDER. A HEAT ADVISORY WILL ONCE AGAIN BE IN EFFECT FOR THE SOUTHERN AND CENTRAL COASTAL PLAIN...THE SANDHILLS AND THE SOUTHEAST PIEDMONT. HEAT INDEX VALUES IN THESE AREAS WILL RANGE FROM 101 TO 105 AGAIN TODAY MAKING IT THE 3RD OR 4TH DAY THIS WEEK WITH SUCH HIGH HEAT INDEX VALUES. EXPECT CONVECTION TO FIRE ONCE AGAIN THIS AFTERNOON WITH A FOCUS INITIALLY ACROSS THE FOOTHILLS AND WESTERN PIEDMONT IN A REGION OF WEAK TO MODERATE INSTABILITY WITH MODEST BULK SHEAR VALUES. ADDITIONAL CONVECTION IS LIKELY TO DEVELOP IN THE SANDHILLS AND SOUTHERN COASTAL PLAIN IN A REGION OF MODERATE TO EVEN STRONG INSTABILITY AND RAP PROGGED DCAPE VALUES GREATER THAN 1300 J/KG. SIMILAR TO THURSDAY...THE MAIN SEVERE WEATHER THREAT WILL BE FROM LOW END ORGANIZED OR MULTICELL STORMS PRODUCING DOWNBURST WINDS. -BLAES && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... AS OF 345 AM EDT FRIDAY... CONVECTION IS LIKELY TO BE ONGOING TONIGHT AT THE START OF THE SHORT TERM PERIOD. THE CONVECTION WILL SHIFT EASTWARD WITH TIME AND DEMONSTRATE A SLOW WEAKENING LATE IN THE EVENING AND DURING THE OVERNIGHT HOURS. LOWS SHOULD RANGE IN THE 60 TO 75 RANGE. THE REMNANTS OF BILL WILL MOVE FROM THE MID-MISSISSIPPI VALLEY TOWARD THE SOUTHERN APPALACHIANS ON SATURDAY. AN INCREASE IN CLOUD COVER AND THE WEAKENING RIDGE WILL RESULT IN MAX TEMPERATURES SIMILAR OR JUST A NUDGE COOLER THAN FRIDAY. SCATTERED CONVECTION IS ONCE AGAIN EXPECTED ON SATURDAY AFTERNOON... MOST FAVORED ACROSS THE WESTERN AND NORTHERN PIEDMONT IN PROXIMITY TO THE APPROACHING UPPER TROUGH AND DEEP MOISTURE. -BLAES && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... AS OF 245 PM THURSDAY... REMNANTS OF TC BILL WILL BE PICKED UP IN THE WESTERLIES AND SWEPT EAST ACROSS THE SOUTHERN OHIO VALLEY INTO THE MID ATLANTIC NORTH OF THE AREA. THE SOUTHERN TAIL OF THE WEAKENING SHEAR AXIS ASSOCIATED WITH THE SHORT WAVE WILL MOVE ACROSS THE AREA SATURDAY NIGHT INTO SUNDAY MORNING. NOT QUITE THE MOST FAVORABLE DIURNAL TIMING AS THE BOUNDARY LAYER WILL STABILIZE OVERNIGHT...BUT THERE WILL BE COPIOUS CAPE ABOVE THE INVERSION AND WOULD EXPECT A LINE OF CONVECTION TO ACCOMPANY THE WAVE AND WILL INCREASE POPS ACROSS THE NORTHERN TIER. SUBSIDENCE BEHIND THE WAVE WILL SUPPRESS CONVECTION ON SUNDAY. HIGHS SATURDAY WILL BE MAINLY IN THE MID 90S...AND WHILE THERE MAY BE LINGERING CLOUDINESS TO DECREASE RADIATION EARLY SUNDAY...SUBSIDENCE WILL ACT AS A COUNTERBALANCE AND LOW LEVEL THICKNESSES RISE 10 METERS SUNDAY...INDICATIVE OF A 2-3 DEGREE RISE...SO WILL BUMP HIGHS TO THE MID 90S NORTH AND UPPER 90S SOUTH. INITIAL ZONAL FLOW MONDAY WILL TIP TO THE NORTHWEST AS AN UPPER RIDGE AMPLIFIES IN THE MIDWEST AND MIGRATES EAST THROUGH THURSDAY. THIS WILL UNFORTUNATELY PROLONG THE HEAT WAVE AS LOW LEVEL THICKNESSES BETWEEN 1430-1440 METERS AND H85 TEMPERATURES ARE EXPECTED TO HOVER AROUND 22C...INDICATIVE OF HIGHS FROM 95 TO 100 EACH DAY. LOWS WILL BE PERSISTENCE...GENERALLY IN THE 72-76 RANGE. HAVE LOW CONFIDENCE IN FORECASTING MESOSCALE CONVECTIVE TRIGGERS IN NORTHWEST FLOW AT THIS TIME RANGE...BUT EXPECT STRONG DIURNAL HEATING TO FIRE CONVECTION IN THE CLIMATOLOGICALLY FAVORED AREAS...IN THE FAR WEST ALONG THE HIGHER TERRAIN...AND ALONG COASTAL SECTIONS WITH INLAND PENETRATION OF SEABREEZE. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... AS OF 245 AM THURSDAY... A LINGERING ARC OF SCATTERED SHOWERS AND STORMS WILL MOVE EASTWARD ACROSS CENTRAL NC AND GRADUALLY WEAKEN DURING THE PREDAWN HOURS. OUTSIDE OF THIS CONVECTION WITH ITS ASSOCIATED LOCAL VSBY AND CIG RESTRICTIONS... MOST OF CENTRAL NC SHOULD EXPERIENCE VFR CONDITIONS DURING THE MORNING HOURS. A BRIEF PERIOD OF FOG OR SHALLOW STRATUS IS POSSIBLE BEFORE DAYBREAK AS SKIES CLEAR AND WINDS RELAX. GENERALLY FAIR WEATHER IS EXPECTED DURING THE MORNING HOURS WITH A VEIL OF HIGH CLOUDS. DIURNAL CUMULUS WILL DEVELOP DURING THE LATE MORNING WITH ANOTHER STORMY LATE AFTERNOON AND EVENING EXPECTED. THE STORMS WILL INITIALLY BE MOST NUMEROUS ACROSS THE TRIAD AREA AND TRANSITION EASTWARD AS ADDITIONAL CONVECTION DEVELOPS IN THE SANDHILLS AND SOUTHERN PIEDMONT. THE CONVECTION WILL GENERALLY DECREASE IN COVERAGE AND INTENSITY LATE IN THE EVENING ALTHOUGH SOME PRECIPITATION WILL PERSIST IN THE EARLY MORNING HOURS ON SATURDAY. LOOKING BEYOND THE 24 HOUR TAF PERIOD...VFR CONDITIONS ARE GENERALLY EXPECTED FOR MUCH OF THE PERIOD ALTHOUGH ANOTHER ROUND OF SCATTERED AFTERNOON AND EVENING CONVECTION IS EXPECTED ON SATURDAY. SUNDAY MAY FEATURE A LULL IN THE PRECIPITATION COVERAGE BEFORE MORE AFTERNOON AND EVENING STORMS ARRIVE FOR MONDAY AND TUESDAY. -BLAES && .CLIMATE... REC REC HI DAY MAX YR MIN YR RDU RECORDS 06/19 102 1944 73 2010 06/20 102 1887 77 1924 06/21 101 1933 75 1933 GSO RECORDS 06/19 100 1944 77 1970 06/20 100 1924 75 2009 06/21 100 1933 75 1924 FAY RECORDS 06/19 102 1944 75 1948 06/20 102 1970 77 2009 06/21 105 1933 74 1999 && .RAH WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY FROM NOON TODAY TO 7 PM EDT THIS EVENING FOR NCZ042-043-077-078-085-086-088-089. && $$ SYNOPSIS...BLAES NEAR TERM...BLAES SHORT TERM...BLAES LONG TERM...CBL AVIATION...BLAES CLIMATE...RAH
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
154 AM EDT FRI JUN 19 2015 .SYNOPSIS... HIGH HUMIDITY AND HEAT WILL CONTINUE THROUGH THE WEEKEND INTO NEXT WEEK. A HEAT ADVISORY REMAINS IN EFFECT FOR TODAY. A FEW SHOWERS AND THUNDERSTORMS WILL ACCOMPANY THE HEAT THROUGH THE WEEKEND MAINLY IN THE AFTERNOON AND EVENINGS. HEAT ADVISORIES MAY BE NEEDED FOR PORTIONS OF NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1100 PM THURSDAY...PATTERN REMAINS RELATIVELY UNCHANGED FROM THE PAST FEW DAYS...WITH A LARGE RIDGE OVERHEAD THAT IS SOMEWHAT TEMPERED BY A STATIONARY BOUNDARY ACROSS THE MID-ATLANTIC AND SEVERAL UPPER IMPULSES ROTATING AROUND THE RIDGE PERIPHERY. AT THE SURFACE...BERMUDA HIGH PRESSURE REMAINS THE DOMINANT FEATURE...BUT ONCE AGAIN A THERMAL TROUGH ACROSS THE PIEDMONT IS DRIVING CONVECTION IN WHAT IS STILL A VERY UNSTABLE AIRMASS JUST ABOVE THE SURFACE. ALTHOUGH THE LOCAL ATMOSPHERE IS QUITE WORKED OVER FROM EARLIER STORMS...THE RESIDUAL LAYER IS MAINTAINING STEEP LAPSE RATES FROM EXTREME SURFACE HEATING THIS AFTN...AND ONCE AGAIN SMALL DISTURBANCES ALOFT WILL TAP THIS AND DRIVE TSTMS OVERNIGHT. AS WINDS HAVE VEERED AROUND TO THE SW ONCE AGAIN...IT APPEARS THE PIEDMONT TROUGH IS REDEVELOPING EVEN AT THIS LATE HOUR...AND AN EXPANSIVE AREA OF SHOWERS AND STORMS HAS FIRED WEST OF THE CWA. MOST OF THIS SHOULD STAY NORTH OF THE LOCAL AREA...BUT A FEW STORMS WILL BE POSSIBLE ESPECIALLY WEST OF I-95...WHERE CHC POP IS CARRIED FOR THE NEXT FEW HOURS. OTHERWISE...ONLY ISOLATED SHOWERS OR TSTMS ARE EXPECTED...AND THE NSSL WRF AND HRRR SHOW A MOSTLY DRY NIGHT LOCALLY. TEMPS WILL AGAIN STAY WELL ABOVE NORMAL...AND MINS HAVE ALREADY BEEN REACHED MOST PLACES WHERE RAIN-COOLED AIR DEVELOPED LATE IN THE EVE. TEMPS WILL BE STEADY OR EVEN RISE A BIT OVERNIGHT...RANGING FROM 75-80. && .SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY NIGHT/... AS OF 300 PM THURSDAY...HOT AND HUMID CONDITIONS CONTINUE WELL INTO THE WEEKEND ALONG WITH INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS EACH DAY AS SURFACE FEATURES...INCREASING MOISTURE AND INSTABILITY COME INTO PLAY. WITH MID TO UPPER RIDGE STILL IN PLACE ACROSS THE SOUTHEAST...JUST BARELY SOUTH AND EAST OF THE FORECAST AREA...A WEAK SFC TROUGH WILL SHIFT INTO THE FORECAST AREA ON FRIDAY WHILE THE REMNANTS OF TROPICAL STORM BILL PUSH EAST-NORTHEASTWARD TOWARDS THE OHIO VALLEY. AS A RESULT...EXPECT SCATTERED CONVECTION ACROSS THE AREA ON FRIDAY...ESPECIALLY ALONG THE SEABREEZE AND ANY LINGERING BOUNDARIES FROM PREVIOUS DAYS CONVECTION. INTO SATURDAY AFTERNOON...A MORE EASTWARD TRACK OF REMNANTS OF BILL...NOW A SHORTWAVE...BECOMES EVIDENT IN LATEST GUIDANCE...WITH A TRACK ALONG THE VA/NC BORDER. AS THIS OCCURS...WILL SEE THE UPPER RIDGE COMPLETELY BREAK DOWN...ALLOWING FOR THE PREDOMINANT FLOW TO CONTINUE OUT OF THE SOUTHWEST. WITH THE AFTERNOON SEABREEZE PUSHING INLAND...EXPECT MAJORITY OF THE MORE ISOLATED IN NATURE CONVECTION TO REMAIN INLAND...THOUGH CANNOT ENTIRELY RULE OUT DEVELOPMENT NEAR THE COAST. WITH PRECIPITABLE WATER VALUES REACHING JUST OVER THE 2 INCH MARK EACH DAY...RAINFALL AMOUNTS COULD AMOUNT TO AROUND THREE QUARTERS OF AN INCH GIVE OR TAKE...WHICH FALLS IN LINE WITH CURRENT WPC QPF FORECAST THROUGH SUNDAY 12Z. A HEAT ADVISORY WILL BE IN EFFECT FOR PORTIONS OF THE AREA ON FRIDAY...WHILE COULD SEE CONDITIONS MET AGAIN ON SATURDAY. THERE WILL BE A BIT OF RELIEF IN ACTUAL TEMPERATURES THOUGH...TRENDING A FEW DEGREES LOWER THAN HAVE SEEN IN PAST DAYS WITH LOW TO MID 90S ALONG THE COAST AND MID 90S INLAND. THIS IS A RESULT OF THE AREA LOOSING THE INFLUENCE OF THE UPPER RIDGE...ALONG WITH ANTICIPATED INCREASED CLOUD COVER AND RAIN COOLED AIR FOR SHOWERS AND THUNDERSTORMS. AS FOR OVERNIGHT LOWS...EXPECT MID 70S EACH NIGHT. && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 300 PM THURSDAY...THE THEME FOR THE EXTENDED REMAINS THE SAME...HOT AND MOSTLY DRY AS THE ATMOSPHERE ACROSS THE SOUTHEAST WILL BE DOMINATED BY DEEP LAYER HIGH PRESSURE. THE AXIS OF THE MID LEVEL RIDGE WILL TAKE ON A SLIGHT NORTHWEST TO SOUTHEAST TILT FROM THE CENTRAL PLAINS TO THE EASTERN GULF COAST. WITH THIS CONFIGURATION...THERE ARE SOME SIGNALS THE AREA COULD BE ON THE SOUTHERN PERIPHERY OF AN OCCASIONAL MCS OR TWO BUT THESE ARE ALL BUT IMPOSSIBLE TO FORECAST DURING THIS TIME FRAME. HAVE MAINTAINED THE MOSTLY SLIGHT CHANCE POPS WITH A SLIGHT NOD TO A DIURNAL PATTERN. THE LATEST MEX NUMBERS HAVE COOLED SLIGHTLY SO THE OFFICIAL FORECAST REMAINS ESSENTIALLY AN UPDATE OF THE PREVIOUS PACKAGE...NOT WANTING TO JUMP ON A COOLING TREND WITHOUT MORE CONSISTENCY. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... AS OF 06Z...ATTM...RESIDUAL AND DYING TSRA AND SHRA CONTINUES TO AFFECT SOUTHEAST NC AND NORTHEAST SC. A DISSIPATING TREND WILL CONTINUE AND SHOULD SEE ALL TERMINALS IN THE CLEAR BY 08Z. THERE IS A REMOTE CHANCE OF TEMPO MVFR VSBYS FROM BR AT KFLO/KLBT DURING THESE PRE-DAWN HOURS IF SKIES CLEAR OUT AND WINDS BECOME LIGHT ENOUGH. CONFIDENCE REMAINS LOW AND WILL HOLD OFF FROM PLACING IT IN THE TAFS. OVERALL...WINDS WILL RECOVER AND BECOME GENERALLY FROM THE SSW-WSW DIRECTION LESS THAN 6 KTS FOR THE REMAINDER OF THE OVERNIGHT. AFTER DAYLIGHT...WINDS WILL BECOME WSW AT 5 TO 10 KT ACROSS ALL TERMINALS. BY EARLY AFTN...THE COASTAL TERMS WILL SEE WINDS BACK TO THE S-SSW 10-15 KT AS A RESULT OF THE SEA BREEZE. ONCE THE ATMOSPHERE DE-STABILIZES BY MIDDAY FRI AND WITH NUMEROUS OUTFLOW BOUNDARIES ACROSS THE FA FROM YESTERDAYS CONVECTIVE ACTIVITY...SHRA/TSRA WILL LIKELY RE-FIRE BY EARLY TO MID-AFTERNOON FRI AND CONTINUE INTO FRI EVENING. EXTENDED OUTLOOK...CHANCE OF SHOWERS/THUNDERSTORMS EACH DAY WITH MAINLY VFR. LESSER CHANCES MONDAY AND TUESDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1100 PM THURSDAY...BERMUDA HIGH HAS RE-ESTABLISHED ITSELF AFTER CONVECTION THIS EVENING CAUSED MESOSCALE CHANGES TO THE WINDS ACROSS THE LOCAL WATERS. AS THIS OCCURS...SW WINDS WILL GRADUALLY INCREASE ONCE AGAIN TO 10-15 KTS...AND THEN PERSIST AT THESE SPEEDS THROUGH THE REST OF THE OVERNIGHT HOURS. SEAS WHICH LIKELY BECAME CHOPPY WITH THE MYRIAD BOUNDARIES AND WIND SHIFTS EARLIER...WILL RE- ATTAIN THE PREDOMINANT SW WIND CHOP...WITH SEAS 2-3 FT INTO FRIDAY MORNING. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 300 PM THURSDAY...A SFC BOUNDARY ON FRIDAY WILL BE FOLLOWED BY THE DECLINING INFLUENCE OF THE UPPER RIDGE ON SATURDAY AS ANOTHER SFC TROUGH PUSHES INTO THE AREA ON SATURDAY. AS A RESULT...EXPECT SOUTHWEST WINDS WILL SHIFT AND BECOME MORE SOUTHERLY BY FRIDAY AFTERNOON...WITH WINDS 10 TO 15 KTS AND SLIGHTLY HIGHER GUSTS POSSIBLE AT TIMES. INTO SATURDAY MORNING...SOUTH-SOUTHWEST WINDS WILL PREVAIL THROUGHOUT THE DAY WITH WINDS AROUND 10 KTS OR LESS. EXPECT SEAS TO RANGE BETWEEN 2 TO 4 FT. LONG TERM /SUNDAY THROUGH TUESDAY/... AS OF 300 PM THURSDAY...SOUTHWEST WINDS OF 10-15 KNOTS WILL PREVAIL ACROSS THE WATERS BASICALLY THROUGH THE PERIOD. EXPECT SOME INCREASE BOTH SUNDAY AND MONDAY NIGHTS VIA A SLIGHTLY ENHANCED NOCTURNAL JET BUT THIS SHOULD JUST ADD A KNOT OR TWO TO THE WIND SPEEDS. SEAS ARE MOSTLY 2-4 FEET. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...HEAT ADVISORY FROM 11 AM THIS MORNING TO 7 PM EDT THIS EVENING FOR SCZ017-023-024-032-033-039-053-055. NC...HEAT ADVISORY FROM 11 AM THIS MORNING TO 7 PM EDT THIS EVENING FOR NCZ087-096-099-105-107-109. MARINE...NONE. && $$ SYNOPSIS...SGL NEAR TERM...MJC SHORT TERM...SGL LONG TERM...SHK AVIATION...DCH/MRR
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1254 PM CDT SAT JUN 20 2015 .UPDATE... ISSUED AT 1244 PM CDT SAT JUN 20 2015 THE FORECAST FOCUS WILL REMAIN ON THE POTENTIAL FOR SEVERE THUNDERSTORMS. THE LATEST STORM PREDICTION CENTER OUTLOOK REMOVED NORTH DAKOTA FROM THE MARGINAL CHANCE OF SEVERE THUNDERSTORMS. THE APPROACHING SHORTWAVE EVIDENT IN WATER VAPOR IMAGERY OVER THE IDAHO PANHANDLE MAY MANAGE TO SPARK A FEW STRONG THUNDERSTORMS AS MIXED LAYER CAPES ARE FORECAST TO BE AROUND 1500 J/KG THIS AFTERNOON. STILL...IT APPEARS COVERAGE WILL BE LOW BASED ON 12 UTC HIRES ARW AND NMM RUNS. UPDATE ISSUED AT 923 AM CDT SAT JUN 20 2015 DENSE FOG ADVISORY HAS EXPIRED AS VISIBILITY HAS IMPROVED ACROSS THE AREA. ALSO ADDED IN A SLIGHT CHANCE OF THUNDERSTORMS SOUTHWEST FOR THE MORNING AS REFLECTIVITY SHOWS STORMS THAT PRODUCED A COUPLE LIGHTNING STRIKES IN MONTANA MOVING INTO FAR SOUTHWESTERN COUNTIES. DO EXPECT THESE STORMS TO DISSIPATE RATHER QUICKLY THIS MORNING AS THEY PROGRESS SOUTHEAST. UPDATE ISSUED AT 632 AM CDT SAT JUN 20 2015 DENSE FOG CONTINUES ACROSS NORTHWEST AND NORTH CENTRAL NORTH DAKOTA. SURFACE OBSERVATIONS AND AREA WXCAMS INDICATE DENSE FOG HAS DRIFTED FARTHER SOUTH OVER CENTRAL NORTH DAKOTA. HAVE EXPANDED THE DENSE FOG ADVISORY AS FAR SOUTH AS THE BISMARCK MANDAN METRO AREA. LOWERED POPS EARLY THIS MORNING ACROSS THE NORTH. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 243 AM CDT SAT JUN 20 2015 MAIN ISSUES IN THE SHORT TERM INCLUDE EARLY MORNING FOG AND AFTERNOON THUNDERSTORMS. MOISTURE IS POOLING IN THE WAKE OF THE DEPARTING MCS IN SOUTH DAKOTA. WITH DEWPOINT DEPRESSIONS RIGHT AROUND ZERO AND LIGHT WINDS...PATCHY TO WIDESPREAD FOG IS EXPECTED TO CONTINUE TO DEVELOP NORTH AND SPREAD SOUTH THROUGH THE EARLY MORNING HOURS. THUNDERSTORMS WILL ONCE AGAIN BE POSSIBLE THIS AFTERNOON/EVENING. AN INVERTED SURFACE TROUGH ACROSS WESTERN NORTH DAKOTA WILL BE THE FOCUS FOR LIFT AND AFTERNOON HEATING WILL PROVIDE THE INSTABILITY. FORCING AND MOISTURE WILL BE LESS THAN TODAY...HOWEVER...WITH AROUND 40 KNOTS OF SHEAR AND 2000 J/KG CAPE FORECAST BY THE WRF/NAM/RAP...SOME STORMS COULD BE STRONG TO SEVERE WITH GUSTY WINDS AND HAIL THE MAIN THREATS. THE 00 UTC WRF AND HRRR SHOW SCATTERED THUNDERSTORMS DEVELOPING NORTH AND EAST OF THE MISSOURI RIVER BY AROUND 3PM THIS AFTERNOON. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 243 AM CDT SAT JUN 20 2015 A CONTINUATION OF SHORTWAVE TROUGHS MIGRATING THROUGH A QUASI-ZONAL FLOW PRODUCING CHANCES FOR SHOWERS/THUNDERSTORMS REMAINS THE THEME. SUNDAY WILL FEATURE A SHORTWAVE TROUGH SLIDING ACROSS NORTHERN NORTH DAKOTA/SOUTHERN CANADA ACCOMPANIED BY A 90KT JET STREAK...IN ADDITION TO A 90 TO 100KT JET STREAK TRACKING FROM THE NORTHERN ROCKIES INTO THE WESTERN DAKOTAS. THERE ARE SOME MODEL DIFFERENCES AND TIMING LOOKS A LITTLE SLOWER THAN PREVIOUS RUNS...BUT THE COMBINED FORCING OF THE TWO JET STREAKS COMBINED WITH DAYTIME HEATING IS EXPECTED TO PRODUCE THUNDERSTORMS OVER EASTERN MONTANA AND THE WESTERN DAKOTAS BY SUNDAY AFTERNOON...AND TRANSLATING ACROSS THE STATE SUNDAY NIGHT. ONCE AGAIN...SOME THUNDERSTORMS COULD BE STRONG TO SEVERE. POSSIBLY SOME LINGERING SHOWER/THUNDERSTORM ACTIVITY OVER THE EASTERN CWA MONDAY MORNING...OTHERWISE MONDAY IS EXPECTED TO BE DRY. AS WE MOVE THROUGH THE REST OF WEEK WE SEE SHORTWAVE TROUGHS EVERY 24HR TO 36HR PROMOTING CHANCES OF SHOWERS/THUNDERSTORMS TUESDAY THROUGH FRIDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1244 PM CDT SAT JUN 20 2015 CONDITIONS HAVE IMPROVED TO MVFR/VFR AT ALL TAF SITES. SCATTERED THUNDERSTORMS ARE FORECAST...BUT TOO LOW CONFIDENCE TO ADD TO TAFS. THE BEST CHANCE FOR ANOTHER ROUND OF IFR FOG IS AT KMOT AFTER 07 UTC TONIGHT. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SCHECK SHORT TERM...AJ LONG TERM...TWH AVIATION...SCHECK
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1240 PM CDT SAT JUN 20 2015 .UPDATE... ISSUED AT 1240 PM CDT SAT JUN 20 2015 NO CHANGES TO PREVIOUS THINKING. VISIBLE SATELLITE SHOWS THINNING OF THE STRATUS DECK WEST OF THE RRV AND INTO WC MN. WITH THE STRONG JUNE SUN...EVEN WITH SOME DIURNAL CUMULUS...TEMPS SHOULD RESPOND QUICKLY...WITH THE COOLEST TEMPS FARTHER NORTH WHERE CLOUDS ARE MORE PERSISTENT. THE HRRR/HOPWRF CONTINUE TO INDICATE SOME DIURNAL CONVECTION DEVELOPING OVER DEVILS LAKE BASIN BY MID-AFTERNOON AND PERSISTING INTO THE EVENING EASTWARD. AN ISOLATED STRONGER STORM IS POSSIBLE...BUT WEAK SFC CONVERGENCE/MODEST INSTABILITY SHOULD LIMIT THIS THREAT IN SPACE/TIME. UPDATE ISSUED AT 945 AM CDT SAT JUN 20 2015 AN AREA OF SHOWERS FROM OTTER TAIL UP THROUGH BELTRAMI COUNTIES CONTINUES TO PUSH EASTWARD...BUT HAVE MAINTAINED HIGHER POPS FOR ANOTHER HOUR. A FEW MORE SHOWERS ARE PUSHING INTO THE FAR NW PART OF THE AREA...SO HAVE MADE SLIGHT POP ADJUSTMENTS. OTHERWISE...THE QUESTIONS FOR TODAY WILL BE HOW QUICKLY CLEARING OCCURS...AND SUBSEQUENT IMPACTS FOR TEMPS AND CONVECTIVE CHANCES. FOR NOW...HAVE JUST SLIGHTLY LOWERED HIGHS OVER THE NE COUNTIES WHERE CLOUDS LOOK TO HANG ON THE LONGEST...AND WILL MONITOR CLOUD TRENDS OVER THE NEXT FEW HOURS. SOME SPOTTY DIURNAL CONVECTION STILL IS POSSIBLE THIS AFTERNOON...WITH THE HRRR FOCUSING ACTIVITY FROM THE N RRV TOWARDS DEVILS LAKE WHERE MID LEVEL TEMPS ARE SLIGHTLY COOLER. SFC CONVERGENCE LOOKS WEAK...AND UPPER FORCING ALSO LOOKS FAIRLY NONDESCRIPT...WITH ANY EMBEDDED IMPULSES QUITE WEAK. WHILE DESTABILIZATION WILL DEPEND ON HOW CLOUD COVER EVOLVES...RAP MUCAPE IS CURRENTLY ONLY ON THE ORDER OF 500-700 J/KG THIS AFTERNOON TOWARDS DEVILS LAKE...WITH DEEP SHEAR AROUND 30-35 KTS. THUS...NOT TOO EXCITED ABOUT STRONGER STORMS...BUT WILL CONTINUE TO MONITOR AS THE DAY WEARS ON. UPDATE ISSUED AT 600 AM CDT SAT JUN 20 2015 WE WILL TWEAK POPS A BIT TO MATCH THE CURRENT TRENDS. THE LOW CLOUDS AND FOG CONTINUES TO EXPAND SOUTH AND WILL ADD SOME AREAS OF FOG TO THE NORTH AND EXTEND UNTIL 15Z. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 340 AM CDT SAT JUN 20 2015 THE MAIN CHALLENGE WILL BE CONVECTIVE CHANCES. MODELS ARE IN GOOD OVERALL AGREEMENT...WITH THE NEXT CHANCE FOR MORE ORGANIZED SHOWERS AND STORMS POSSIBLE SUNDAY NIGHT. FOR TODAY...SPC HAS ADDED A MARGINAL RISK FOR A FEW SEVERE STORMS WITH HAIL/WIND TO THE DEVILS LAKE BASIN. THERE WILL BE A FEW SHORTWAVES IN ACTIVE WESTERLY FLOW ALOFT...COMBINED WITH SFC CAPE AROUND 1500 J/KG. THERE COULD BE SOME LINGERING CONVECTION IN THE EAST AND SOUTH EARLY THIS MORNING...WITH MOST AREAS DRY TODAY. A BAND OF LOWER CLOUDS IN THE NORTH COULD AFFECT TEMPS TODAY UNTIL THEY BURN OFF LATER THIS MORNING. FOR TONIGHT...THERE COULD BE A FEW DIURNALLY DRIVEN SHOWERS AND STORMS MAINLY ALONG AND WEST OF THE VALLEY THIS EVENING. OTHERWISE...EXPECT A DRY NIGHT AND CAN/T RULE OUT SOME FOG WHERE IT CLEARS WITH A WEAK SFC HIGH BUILDING IN. ON SUNDAY...EXPECT A DRY DAY WITH WEAK RIDGING AND FAIRLY WARM TEMPS AROUND 80 FOR MOST. THERE WILL BE A SHORTWAVE APPROACHING THE FAR WEST LATE IN THE DAY...BUT ANY CONVECTION SHOULD HOLD OFF UNTIL SUNDAY NIGHT. THERE COULD BE A FEW SHOWERS AND STORMS IN THE FAR EAST CLOSER TO A DEPARTING COOL POOL ALOFT. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 340 AM CDT SAT JUN 20 2015 FOR SUNDAY NIGHT...EXPECT A STRONG SHORTWAVE TO MOVE THROUGH FAST WESTERLY FLOW ALOFT. THERE WILL BE FAIRLY STRONG MID LEVEL MOISTURE TRANSPORT WITH SHOWALTERS FALLING TO AROUND -4C AND A 40KT LLJ INTO THE AREA. MODELS ALL AGREE THAT A FAIRLY ORGANIZED CONVECTIVE CLUSTER IS LIKELY...WITH MOST AREAS GETTING MEASURABLE RAIN AT LEAST. WILL GO WITH LIKELY POPS FOR MOST AREAS WITH A FEW STRONGER STORMS POSSIBLE AS WELL. ON MONDAY...THERE WILL BE SOME LINGERING CONVECTION IN THE MORNING WITH MOST AREAS DRY BY AFTERNOON. TEMPS WILL COOL SOME FROM MONDAY BEHIND A COOL FRONT. TUESDAY TO FRIDAY...ACTIVE WEATHER PATTERN IS EXPECTED TO CONTINUE WITH SHORT WAVES IN THE ZONAL TO WEAK NW FLOW INTERACTING WITH INCREASING PWATS AS EVAPOTRANSPIRATION IS BEGINNING TO TAKE OFF ACROSS THE CENTRAL AND NORTHERN PLAINS. DRY FOR TUESDAY WITH 20 TO 30 POP EXPECTED TUES NIGHT NIGHT THRU THURSDAY AND THEN DRY FRIDAY. AGAIN SCATTERED NATURE OF THE RAINFALL WITH NO WIDE SPREAD RAINS EXPECTED. TEMPS TO BE NEAR NORMAL WITH UPPER 70S TO 80 FOR HIGHS AND UPPER 50S TO NEAR 60 FOR LOWS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1240 PM CDT SAT JUN 20 2015 LOW CLOUDS WILL GRADUALLY BREAK UP THIS AFTN AND THE TIMING OF THIS IS THE CHALLENGE THRU 00Z. THE LOW CLOUDS WILL BREAK UP AND WITH ENOUGH SUN A HIGHER BASED CU WILL FORM....BROKEN IN COVERAGE. SKIES WILL SCATTER OUT TOWARD SUNSET WITH VFR CONDITIONS OVERNIGHT INTO SUNDAY MORNING. COULD BE SOME PATCHY FOG LATE TONIGHT/SUN MORNING BUT NOT INCLUDED DUE TO LOW CONFIDENCE IN ANY ONE SPOT. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...MAKOWSKI SHORT TERM...DK LONG TERM...JK/DK AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
945 AM CDT SAT JUN 20 2015 .UPDATE... ISSUED AT 945 AM CDT SAT JUN 20 2015 AN AREA OF SHOWERS FROM OTTER TAIL UP THROUGH BELTRAMI COUNTIES CONTINUES TO PUSH EASTWARD...BUT HAVE MAINTAINED HIGHER POPS FOR ANOTHER HOUR. A FEW MORE SHOWERS ARE PUSHING INTO THE FAR NW PART OF THE AREA...SO HAVE MADE SLIGHT POP ADJUSTMENTS. OTHERWISE...THE QUESTIONS FOR TODAY WILL BE HOW QUICKLY CLEARING OCCURS...AND SUBSEQUENT IMPACTS FOR TEMPS AND CONVECTIVE CHANCES. FOR NOW...HAVE JUST SLIGHTLY LOWERED HIGHS OVER THE NE COUNTIES WHERE CLOUDS LOOK TO HANG ON THE LONGEST...AND WILL MONITOR CLOUD TRENDS OVER THE NEXT FEW HOURS. SOME SPOTTY DIURNAL CONVECTION STILL IS POSSIBLE THIS AFTERNOON...WITH THE HRRR FOCUSING ACTIVITY FROM THE N RRV TOWARDS DEVILS LAKE WHERE MID LEVEL TEMPS ARE SLIGHTLY COOLER. SFC CONVERGENCE LOOKS WEAK...AND UPPER FORCING ALSO LOOKS FAIRLY NONDESCRIPT...WITH ANY EMBEDDED IMPULSES QUITE WEAK. WHILE DESTABILIZATION WILL DEPEND ON HOW CLOUD COVER EVOLVES...RAP MUCAPE IS CURRENTLY ONLY ON THE ORDER OF 500-700 J/KG THIS AFTERNOON TOWARDS DEVILS LAKE...WITH DEEP SHEAR AROUND 30-35 KTS. THUS...NOT TOO EXCITED ABOUT STRONGER STORMS...BUT WILL CONTINUE TO MONITOR AS THE DAY WEARS ON. UPDATE ISSUED AT 600 AM CDT SAT JUN 20 2015 WE WILL TWEAK POPS A BIT TO MATCH THE CURRENT TRENDS. THE LOW CLOUDS AND FOG CONTINUES TO EXPAND SOUTH AND WILL ADD SOME AREAS OF FOG TO THE NORTH AND EXTEND UNTIL 15Z. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 340 AM CDT SAT JUN 20 2015 THE MAIN CHALLENGE WILL BE CONVECTIVE CHANCES. MODELS ARE IN GOOD OVERALL AGREEMENT...WITH THE NEXT CHANCE FOR MORE ORGANIZED SHOWERS AND STORMS POSSIBLE SUNDAY NIGHT. FOR TODAY...SPC HAS ADDED A MARGINAL RISK FOR A FEW SEVERE STORMS WITH HAIL/WIND TO THE DEVILS LAKE BASIN. THERE WILL BE A FEW SHORTWAVES IN ACTIVE WESTERLY FLOW ALOFT...COMBINED WITH SFC CAPE AROUND 1500 J/KG. THERE COULD BE SOME LINGERING CONVECTION IN THE EAST AND SOUTH EARLY THIS MORNING...WITH MOST AREAS DRY TODAY. A BAND OF LOWER CLOUDS IN THE NORTH COULD AFFECT TEMPS TODAY UNTIL THEY BURN OFF LATER THIS MORNING. FOR TONIGHT...THERE COULD BE A FEW DIURNALLY DRIVEN SHOWERS AND STORMS MAINLY ALONG AND WEST OF THE VALLEY THIS EVENING. OTHERWISE...EXPECT A DRY NIGHT AND CAN/T RULE OUT SOME FOG WHERE IT CLEARS WITH A WEAK SFC HIGH BUILDING IN. ON SUNDAY...EXPECT A DRY DAY WITH WEAK RIDGING AND FAIRLY WARM TEMPS AROUND 80 FOR MOST. THERE WILL BE A SHORTWAVE APPROACHING THE FAR WEST LATE IN THE DAY...BUT ANY CONVECTION SHOULD HOLD OFF UNTIL SUNDAY NIGHT. THERE COULD BE A FEW SHOWERS AND STORMS IN THE FAR EAST CLOSER TO A DEPARTING COOL POOL ALOFT. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 340 AM CDT SAT JUN 20 2015 FOR SUNDAY NIGHT...EXPECT A STRONG SHORTWAVE TO MOVE THROUGH FAST WESTERLY FLOW ALOFT. THERE WILL BE FAIRLY STRONG MID LEVEL MOISTURE TRANSPORT WITH SHOWALTERS FALLING TO AROUND -4C AND A 40KT LLJ INTO THE AREA. MODELS ALL AGREE THAT A FAIRLY ORGANIZED CONVECTIVE CLUSTER IS LIKELY...WITH MOST AREAS GETTING MEASURABLE RAIN AT LEAST. WILL GO WITH LIKELY POPS FOR MOST AREAS WITH A FEW STRONGER STORMS POSSIBLE AS WELL. ON MONDAY...THERE WILL BE SOME LINGERING CONVECTION IN THE MORNING WITH MOST AREAS DRY BY AFTERNOON. TEMPS WILL COOL SOME FROM MONDAY BEHIND A COOL FRONT. TUESDAY TO FRIDAY...ACTIVE WEATHER PATTERN IS EXPECTED TO CONTINUE WITH SHORT WAVES IN THE ZONAL TO WEAK NW FLOW INTERACTING WITH INCREASING PWATS AS EVAPOTRANSPIRATION IS BEGINNING TO TAKE OFF ACROSS THE CENTRAL AND NORTHERN PLAINS. DRY FOR TUESDAY WITH 20 TO 30 POP EXPECTED TUES NIGHT NIGHT THRU THURSDAY AND THEN DRY FRIDAY. AGAIN SCATTERED NATURE OF THE RAINFALL WITH NO WIDE SPREAD RAINS EXPECTED. TEMPS TO BE NEAR NORMAL WITH UPPER 70S TO 80 FOR HIGHS AND UPPER 50S TO NEAR 60 FOR LOWS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 600 AM CDT SAT JUN 20 2015 A FAIRLY LARGE AREA OF IFR CIGS AND SOME FOG HAS DEVELOPED IN THE RED RIVER VALLEY INTO THE DEVILS LAKE BASIN. THE LATEST HRRR IS SLOW TO ERODE THIS FEATURE...AND THEY SHOULD LINGER UNTIL AT LEAST 18-20Z TIMEFRAME. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...MAKOWSKI SHORT TERM...DK LONG TERM...JK/DK AVIATION...DK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
932 AM CDT SAT JUN 20 2015 .UPDATE... ISSUED AT 923 AM CDT SAT JUN 20 2015 DENSE FOG ADVISORY HAS EXPIRED AS VISIBILITY HAS IMPROVED ACROSS THE AREA. ALSO ADDED IN A SLIGHT CHANCE OF THUNDERSTORMS SOUTHWEST FOR THE MORNING AS REFLECTIVITY SHOWS STORMS THAT PRODUCED A COUPLE LIGHTNING STRIKES IN MONTANA MOVING INTO FAR SOUTHWESTERN COUNTIES. DO EXPECT THESE STORMS TO DISSIPATE RATHER QUICKLY THIS MORNING AS THEY PROGRESS SOUTHEAST. UPDATE ISSUED AT 632 AM CDT SAT JUN 20 2015 DENSE FOG CONTINUES ACROSS NORTHWEST AND NORTH CENTRAL NORTH DAKOTA. SURFACE OBSERVATIONS AND AREA WXCAMS INDICATE DENSE FOG HAS DRIFTED FARTHER SOUTH OVER CENTRAL NORTH DAKOTA. HAVE EXPANDED THE DENSE FOG ADVISORY AS FAR SOUTH AS THE BISMARCK MANDAN METRO AREA. LOWERED POPS EARLY THIS MORNING ACROSS THE NORTH. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 243 AM CDT SAT JUN 20 2015 MAIN ISSUES IN THE SHORT TERM INCLUDE EARLY MORNING FOG AND AFTERNOON THUNDERSTORMS. MOISTURE IS POOLING IN THE WAKE OF THE DEPARTING MCS IN SOUTH DAKOTA. WITH DEWPOINT DEPRESSIONS RIGHT AROUND ZERO AND LIGHT WINDS...PATCHY TO WIDESPREAD FOG IS EXPECTED TO CONTINUE TO DEVELOP NORTH AND SPREAD SOUTH THROUGH THE EARLY MORNING HOURS. THUNDERSTORMS WILL ONCE AGAIN BE POSSIBLE THIS AFTERNOON/EVENING. AN INVERTED SURFACE TROUGH ACROSS WESTERN NORTH DAKOTA WILL BE THE FOCUS FOR LIFT AND AFTERNOON HEATING WILL PROVIDE THE INSTABILITY. FORCING AND MOISTURE WILL BE LESS THAN TODAY...HOWEVER...WITH AROUND 40 KNOTS OF SHEAR AND 2000 J/KG CAPE FORECAST BY THE WRF/NAM/RAP...SOME STORMS COULD BE STRONG TO SEVERE WITH GUSTY WINDS AND HAIL THE MAIN THREATS. THE OO UTC WRF AND HRRR SHOW SCATTERED THUNDERSTORMS DEVELOPING NORTH AND EAST OF THE MISSOURI RIVER BY AROUND 3PM THIS AFTERNOON. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 243 AM CDT SAT JUN 20 2015 A CONTINUATION OF SHORTWAVE TROUGHS MIGRATING THROUGH A QUASI-ZONAL FLOW PRODUCING CHANCES FOR SHOWERS/THUNDERSTORMS REMAINS THE THEME. SUNDAY WILL FEATURE A SHORTWAVE TROUGH SLIDING ACROSS NORTHERN NORTH DAKOTA/SOUTHERN CANADA ACCOMPANIED BY A 90KT JETSTREAK...IN ADDITION TO A 90 TO 100KT JETSTREAK TRACKING FROM THE NORTHERN ROCKIES INTO THE WESTERN DAKOTAS. THERE ARE SOME MODEL DIFFERENCES AND TIMING LOOKS A LITTLE SLOWER THAN PREVIOUS RUNS...BUT THE COMBINED FORCING OF THE TWO JET STREAKS COMBINED WITH DAYTIME HEATING IS EXPECTED TO PRODUCE THUNDERSTORMS OVER EASTERN MONTANA AND THE WESTERN DAKOTAS BY SUNDAY AFTERNOON...AND TRANSLATING ACROSS THE STATE SUNDAY NIGHT. ONCE AGAIN...SOME THUNDERSTORMS COULD BE STRONG TO SEVERE. POSSIBLY SOME LINGERING SHOWER/THUNDERSTORM ACTIVITY OVER THE EASTERN CWA MONDAY MORNING...OTHERWISE MONDAY IS EXPECTED TO BE DRY. AS WE MOVE THROUGH THE REST OF WEEK WE SEE SHORTWAVE TROUGHS EVERY 24HR TO 36HR PROMOTING CHANCES OF SHOWERS/THUNDERSTORMS TUESDAY THROUGH FRIDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 632 AM CDT SAT JUN 20 2015 LIFR CONDITIONS IN FOG WILL CONTINUE AT KMOT THROUGH THE EARLY MORNING HOURS...AND HAD EXPANDED SOUTH TO INCLUDE KBIS AT 12 UTC. OTHERWISE...OCCASIONAL MVFR/IFR CONDITIONS ARE POSSIBLE AT KJMS AND KISN...WITH VFR EXPECTED AT KDIK. CONDITIONS WILL IMPROVE ACROSS ALL TAF SITES BY LATE MORNING. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...MM SHORT TERM...AJ LONG TERM...TWH AVIATION...TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
637 AM CDT SAT JUN 20 2015 .UPDATE... ISSUED AT 632 AM CDT SAT JUN 20 2015 DENSE FOG CONTINUES ACROSS NORTHWEST AND NORTH CENTRAL NORTH DAKOTA. SURFACE OBSERVATIONS AND AREA WXCAMS INDICATE DENSE FOG HAS DRIFTED FARTHER SOUTH OVER CENTRAL NORTH DAKOTA. HAVE EXPANDED THE DENSE FOG ADVISORY AS FAR SOUTH AS THE BISMARCK MANDAN METRO AREA. LOWERED POPS EARLY THIS MORNING ACROSS THE NORTH. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 243 AM CDT SAT JUN 20 2015 MAIN ISSUES IN THE SHORT TERM INCLUDE EARLY MORNING FOG AND AFTERNOON THUNDERSTORMS. MOISTURE IS POOLING IN THE WAKE OF THE DEPARTING MCS IN SOUTH DAKOTA. WITH DEWPOINT DEPRESSIONS RIGHT AROUND ZERO AND LIGHT WINDS...PATCHY TO WIDESPREAD FOG IS EXPECTED TO CONTINUE TO DEVELOP NORTH AND SPREAD SOUTH THROUGH THE EARLY MORNING HOURS. THUNDERSTORMS WILL ONCE AGAIN BE POSSIBLE THIS AFTERNOON/EVENING. AN INVERTED SURFACE TROUGH ACROSS WESTERN NORTH DAKOTA WILL BE THE FOCUS FOR LIFT AND AFTERNOON HEATING WILL PROVIDE THE INSTABILITY. FORCING AND MOISTURE WILL BE LESS THAN TODAY...HOWEVER...WITH AROUND 40 KNOTS OF SHEAR AND 2000 J/KG CAPE FORECAST BY THE WRF/NAM/RAP...SOME STORMS COULD BE STRONG TO SEVERE WITH GUSTY WINDS AND HAIL THE MAIN THREATS. THE OO UTC WRF AND HRRR SHOW SCATTERED THUNDERSTORMS DEVELOPING NORTH AND EAST OF THE MISSOURI RIVER BY AROUND 3PM THIS AFTERNOON. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 243 AM CDT SAT JUN 20 2015 A CONTINUATION OF SHORTWAVE TROUGHS MIGRATING THROUGH A QUASI-ZONAL FLOW PRODUCING CHANCES FOR SHOWERS/THUNDERSTORMS REMAINS THE THEME. SUNDAY WILL FEATURE A SHORTWAVE TROUGH SLIDING ACROSS NORTHERN NORTH DAKOTA/SOUTHERN CANADA ACCOMPANIED BY A 90KT JETSTREAK...IN ADDITION TO A 90 TO 100KT JETSTREAK TRACKING FROM THE NORTHERN ROCKIES INTO THE WESTERN DAKOTAS. THERE ARE SOME MODEL DIFFERENCES AND TIMING LOOKS A LITTLE SLOWER THAN PREVIOUS RUNS...BUT THE COMBINED FORCING OF THE TWO JET STREAKS COMBINED WITH DAYTIME HEATING IS EXPECTED TO PRODUCE THUNDERSTORMS OVER EASTERN MONTANA AND THE WESTERN DAKOTAS BY SUNDAY AFTERNOON...AND TRANSLATING ACROSS THE STATE SUNDAY NIGHT. ONCE AGAIN...SOME THUNDERSTORMS COULD BE STRONG TO SEVERE. POSSIBLY SOME LINGERING SHOWER/THUNDERSTORM ACTIVITY OVER THE EASTERN CWA MONDAY MORNING...OTHERWISE MONDAY IS EXPECTED TO BE DRY. AS WE MOVE THROUGH THE REST OF WEEK WE SEE SHORTWAVE TROUGHS EVERY 24HR TO 36HR PROMOTING CHANCES OF SHOWERS/THUNDERSTORMS TUESDAY THROUGH FRIDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 632 AM CDT SAT JUN 20 2015 LIFR CONDITIONS IN FOG WILL CONTINUE AT KMOT THROUGH THE EARLY MORNING HOURS...AND HAD EXPANDED SOUTH TO INCLUDE KBIS AT 12 UTC. OTHERWISE...OCCASIONAL MVFR/IFR CONDITIONS ARE POSSIBLE AT KJMS AND KISN...WITH VFR EXPECTED AT KDIK. CONDITIONS WILL IMPROVE ACROSS ALL TAF SITES BY LATE MORNING. && .BIS WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR NDZ001>005- 009>013-019>023-034-035. && $$ UPDATE...TWH SHORT TERM...AJ LONG TERM...TWH AVIATION...TWH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
559 AM CDT SAT JUN 20 2015 .UPDATE... ISSUED AT 600 AM CDT SAT JUN 20 2015 WE WILL TWEAK POPS A BIT TO MATCH THE CURRENT TRENDS. THE LOW CLOUDS AND FOG CONTINUES TO EXPAND SOUTH AND WILL ADD SOME AREAS OF FOG TO THE NORTH AND EXTEND UNTIL 15Z. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 340 AM CDT SAT JUN 20 2015 THE MAIN CHALLENGE WILL BE CONVECTIVE CHANCES. MODELS ARE IN GOOD OVERALL AGREEMENT...WITH THE NEXT CHANCE FOR MORE ORGANIZED SHOWERS AND STORMS POSSIBLE SUNDAY NIGHT. FOR TODAY...SPC HAS ADDED A MARGINAL RISK FOR A FEW SEVERE STORMS WITH HAIL/WIND TO THE DEVILS LAKE BASIN. THERE WILL BE A FEW SHORTWAVES IN ACTIVE WESTERLY FLOW ALOFT...COMBINED WITH SFC CAPE AROUND 1500 J/KG. THERE COULD BE SOME LINGERING CONVECTION IN THE EAST AND SOUTH EARLY THIS MORNING...WITH MOST AREAS DRY TODAY. A BAND OF LOWER CLOUDS IN THE NORTH COULD AFFECT TEMPS TODAY UNTIL THEY BURN OFF LATER THIS MORNING. FOR TONIGHT...THERE COULD BE A FEW DIURNALLY DRIVEN SHOWERS AND STORMS MAINLY ALONG AND WEST OF THE VALLEY THIS EVENING. OTHERWISE...EXPECT A DRY NIGHT AND CAN/T RULE OUT SOME FOG WHERE IT CLEARS WITH A WEAK SFC HIGH BUILDING IN. ON SUNDAY...EXPECT A DRY DAY WITH WEAK RIDGING AND FAIRLY WARM TEMPS AROUND 80 FOR MOST. THERE WILL BE A SHORTWAVE APPROACHING THE FAR WEST LATE IN THE DAY...BUT ANY CONVECTION SHOULD HOLD OFF UNTIL SUNDAY NIGHT. THERE COULD BE A FEW SHOWERS AND STORMS IN THE FAR EAST CLOSER TO A DEPARTING COOL POOL ALOFT. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 340 AM CDT SAT JUN 20 2015 FOR SUNDAY NIGHT...EXPECT A STRONG SHORTWAVE TO MOVE THROUGH FAST WESTERLY FLOW ALOFT. THERE WILL BE FAIRLY STRONG MID LEVEL MOISTURE TRANSPORT WITH SHOWALTERS FALLING TO AROUND -4C AND A 40KT LLJ INTO THE AREA. MODELS ALL AGREE THAT A FAIRLY ORGANIZED CONVECTIVE CLUSTER IS LIKELY...WITH MOST AREAS GETTING MEASURABLE RAIN AT LEAST. WILL GO WITH LIKELY POPS FOR MOST AREAS WITH A FEW STRONGER STORMS POSSIBLE AS WELL. ON MONDAY...THERE WILL BE SOME LINGERING CONVECTION IN THE MORNING WITH MOST AREAS DRY BY AFTERNOON. TEMPS WILL COOL SOME FROM MONDAY BEHIND A COOL FRONT. TUESDAY TO FRIDAY...ACTIVE WEATHER PATTERN IS EXPECTED TO CONTINUE WITH SHORT WAVES IN THE ZONAL TO WEAK NW FLOW INTERACTING WITH INCREASING PWATS AS EVAPOTRANSPIRATION IS BEGINNING TO TAKE OFF ACROSS THE CENTRAL AND NORTHERN PLAINS. DRY FOR TUESDAY WITH 20 TO 30 POP EXPECTED TUES NIGHT NIGHT THRU THURSDAY AND THEN DRY FRIDAY. AGAIN SCATTERED NATURE OF THE RAINFALL WITH NO WIDE SPREAD RAINS EXPECTED. TEMPS TO BE NEAR NORMAL WITH UPPER 70S TO 80 FOR HIGHS AND UPPER 50S TO NEAR 60 FOR LOWS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 600 AM CDT SAT JUN 20 2015 A FAIRLY LARGE AREA OF IFR CIGS AND SOME FOG HAS DEVELOPED IN THE RED RIVER VALLEY INTO THE DEVILS LAKE BASIN. THE LATEST HRRR IS SLOW TO ERODE THIS FEATURE...AND THEY SHOULD LINGER UNTIL AT LEAST 18-20Z TIMEFRAME. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...DK SHORT TERM...DK LONG TERM...JK/DK AVIATION...DK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
313 AM CDT SAT JUN 20 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 243 AM CDT SAT JUN 20 2015 MAIN ISSUES IN THE SHORT TERM INCLUDE EARLY MORNING FOG AND AFTERNOON THUNDERSTORMS. MOISTURE IS POOLING IN THE WAKE OF THE DEPARTING MCS IN SOUTH DAKOTA. WITH DEWPOINT DEPRESSIONS RIGHT AROUND ZERO AND LIGHT WINDS...PATCHY TO WIDESPREAD FOG IS EXPECTED TO CONTINUE TO DEVELOP NORTH AND SPREAD SOUTH THROUGH THE EARLY MORNING HOURS. THUNDERSTORMS WILL ONCE AGAIN BE POSSIBLE THIS AFTERNOON/EVENING. AN INVERTED SURFACE TROUGH ACROSS WESTERN NORTH DAKOTA WILL BE THE FOCUS FOR LIFT AND AFTERNOON HEATING WILL PROVIDE THE INSTABILITY. FORCING AND MOISTURE WILL BE LESS THAN TODAY...HOWEVER...WITH AROUND 40 KNOTS OF SHEAR AND 2000 J/KG CAPE FORECAST BY THE WRF/NAM/RAP...SOME STORMS COULD BE STRONG TO SEVERE WITH GUSTY WINDS AND HAIL THE MAIN THREATS. THE OO UTC WRF AND HRRR SHOW SCATTERED THUNDERSTORMS DEVELOPING NORTH AND EAST OF THE MISSOURI RIVER BY AROUND 3PM THIS AFTERNOON. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 243 AM CDT SAT JUN 20 2015 A CONTINUATION OF SHORTWAVE TROUGHS MIGRATING THROUGH A QUASI-ZONAL FLOW PRODUCING CHANCES FOR SHOWERS/THUNDERSTORMS REMAINS THE THEME. SUNDAY WILL FEATURE A SHORTWAVE TROUGH SLIDING ACROSS NORTHERN NORTH DAKOTA/SOUTHERN CANADA ACCOMPANIED BY A 90KT JETSTREAK...IN ADDITION TO A 90 TO 100KT JETSTREAK TRACKING FROM THE NORTHERN ROCKIES INTO THE WESTERN DAKOTAS. THERE ARE SOME MODEL DIFFERENCES AND TIMING LOOKS A LITTLE SLOWER THAN PREVIOUS RUNS...BUT THE COMBINED FORCING OF THE TWO JET STREAKS COMBINED WITH DAYTIME HEATING IS EXPECTED TO PRODUCE THUNDERSTORMS OVER EASTERN MONTANA AND THE WESTERN DAKOTAS BY SUNDAY AFTERNOON...AND TRANSLATING ACROSS THE STATE SUNDAY NIGHT. ONCE AGAIN...SOME THUNDERSTORMS COULD BE STRONG TO SEVERE. POSSIBLY SOME LINGERING SHOWER/THUNDERSTORM ACTIVITY OVER THE EASTERN CWA MONDAY MORNING...OTHERWISE MONDAY IS EXPECTED TO BE DRY. AS WE MOVE THROUGH THE REST OF WEEK WE SEE SHORTWAVE TROUGHS EVERY 24HR TO 36HR PROMOTING CHANCES OF SHOWERS/THUNDERSTORMS TUESDAY THROUGH FRIDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1146 PM CDT FRI JUN 19 2015 THUNDERSTORMS WILL MOVE OUT OF KJMS SHORTLY AFTER THE 06Z ISSUANCE. KBIS WILL BRIEFLY SEE SHOWERS AND VCTS OVER THE NEXT COUPLE OF HOURS. OTHERWISE VFR...WITH SOME POSSIBLE MVFR CONDITIONS LATER TONIGHT. CIGS WILL IMPROVE BY MID MORNING SATURDAY TO VFR EVERYWHERE. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...AJ LONG TERM...TWH AVIATION...AJ
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1150 PM CDT FRI JUN 19 2015 .UPDATE... ISSUED AT 1150 PM CDT FRI JUN 19 2015 STORMS MOVING INTO EASTERN ND HAVE LOST THE BOWING AND HIGH WINDS THEY HAD EARLIER...BUT WILL HAVE TO WATCH CONVECTION POPPING UP AHEAD OF THE MCS FOR ANY PULSING UP TO PRODUCE SOME HAIL OR WIND GUSTS. OVERALL THERE SEEMS TO BE A WEAKENING TREND AS STORMS BECOME ELEVATED. RAP HAS BEEN DOING POORLY WITH PRECIP SO LEANED MORE TOWARDS THE NAM FOR THE REST OF THE NIGHT. SHOWERS AND STORMS WILL CONTINUE TO BE NUMEROUS MAINLY IN THE SOUTHERN COUNTIES...BUT THERE SHOULD BE A DECENT CHANCE FOR PRECIP FURTHER NORTH ALSO. THE ACTIVITY WILL BE MAINLY OVER WEST CENTRAL AND NORTHWEST MN TOWARDS MORNING...AND SOME PRECIP MAY BE LINGERING IN THE FAR EASTERN TIER AFTER 12Z. UPDATE ISSUED AT 951 PM CDT FRI JUN 19 2015 STORMS OVER THE WESTERN PART OF ND HAVE EVOLVED INTO A MCS CURRENTLY MOVING THROUGH THE EASTERN PART OF BIS CWA. SUBSIDENCE HAS KEPT CONVECTION ALONG THE FRONT INTO THE RED RIVER VALLEY SUPPRESSED...BUT ACTIVITY SHOULD BE INCREASING AS THE MCS MOVES INTO EASTERN ND. THERE IS STILL A GOOD AMOUNT OF INSTABILITY TO WORK WITH...AND WILL HAVE TO WATCH HOW IT INTERACTS WITH THE FRONTAL BOUNDARY CURRENTLY ACROSS THE CENTRAL CWA. THINK THAT THE BEST SEVERE CHANCES WILL BE ACROSS THE SOUTHERN CWA WHICH FITS THE TRACK OF THE BOW...SO KEPT SEVERE T MENTION THERE BUT AT THIS POINT IT SEEMS THE DEVILS LAKE BASIN WILL NOT GET MUCH WIND OR HAIL SO REMOVED SEVERE WORDING THERE. UPDATE ISSUED AT 652 PM CDT FRI JUN 19 2015 SOME CU AND SHOWERS HAVE TRIED TO GO UP ALONG THE FRONTAL BOUNDARY DRAPED FROM COOPERSTOWN TO GRAFTON TO THE LAKE OF THE WOODS AREA. OVER OUR NORTHEASTERN COUNTIES THERE HAS BEEN SOME ONGOING ACTIVITY ON THE NOSE OF THE LOW LEVEL JET...BUT FURTHER WEST CELLS HAVE STRUGGLED UNDER THE SUBSIDENCE ON THE BACKSIDE OF A DEPARTING SHORTWAVE TROUGH. DO NOT THINK WE WILL SEE MUCH UNTIL THE NEXT SHORTWAVE COMES OUT OF MONTANA LATER TONIGHT. HAVE SOME POPS COMING INTO OUR WEST AROUND 03Z...ALONG WITH ONGOING POPS IN THE NORTHEASTERN CORNER. CONVECTION SHOULD PICK UP LATER TONIGHT AS WE GET THE SHORTWAVE COMING OUT. KEPT HIGHEST POPS IN THE SOUTH FOR NOW BUT WILL ADJUST AS NEEDED DEPENDING ON HOW THE STORMS JUST MOVING INTO WESTERN ND BEHAVE. && .SHORT TERM...(THIS EVENING AND OVERNIGHT) ISSUED AT 315 PM CDT FRI JUN 19 2015 LATEST GUIDANCE AND OBSERVATIONS AGREE WITH PREVIOUS THINKING. SFC BOUNDARY WITH MLCAPE 1000-1500 J/KG HAS SET UP FROM SW ND INTO THE GRAND FORKS AREA. THIS REGION IS CURRENTLY ON THE SUBSIDENCE SIDE OF A DEPARTING SHORTWAVE...WHICH WILL LIKELY SUPPRESS CONVECTION FOR A FEW MORE HOURS. STRONGER SYNOPTIC FORCING ARRIVES THIS EVENING...SPREADING ACTIVITY INTO THE REGION. LATEST CAM GUIDANCE CONTINUES TO SUGGEST STRONGEST STORMS WILL BE ACROSS SOUTH DAKOTA (STRONGEST FORCING ON NOSE OF THE LOW LEVEL JET...INSTABILITY..ETC). HOWEVER...THERE WILL BE A SEVERE THREAT ACROSS SOUTHEAST NORTH DAKOTA INTO WEST CENTRAL MINNESOTA DURING THE 03Z-09Z PERIOD WITH FORCING FROM A MORE NORTHERN UPPER WAVE OVERRIDING THE REGION. GUIDANCE SUGGESTS THIS FORCING WILL INTERACT WITH MUCAPE 1000-1500 J/KG AND 35-45 KNOTS DEEP LAYER SHEAR. HRRR SUGGESTS A FEW STRONGER STORMS WILL BE POSSIBLE WITHIN THIS ENVIRONMENT (MARGINALLY LARGE HAIL WITH MARGINALLY SEVERE WIND GUSTS THE LIKELY THREATS...TORNADO THREAT APPEARS LOW GIVEN WEAK 0-3KM BULK SHEAR DURING THIS TIMEFRAME). SEVERE THREAT WOULD APPEAR TO QUICKLY DROP TOWARD THE INTERNATIONAL BORDER AS THE SOUTHERN ACTIVITY DOMINATES THE SCENE. WILL ALSO NEED TO WATCH FOR HEAVY RAIN AND FLASH FLOOD POTENTIAL IF A WEST TO EAST BOUNDARY (AND TRAINING STORMS) SETS UP NEAR THE SOUTHERN FA. THIS IS A POSSIBILITY...BUT A LOW PROBABILITY GIVEN THE STRONGER SYSTEM EXPECTED ACROSS SOUTH DAKOTA. .LONG TERM...(SATURDAY THROUGH FRIDAY) ISSUED AT 315 PM CDT FRI JUN 19 2015 SATURDAY-MONDAY...ACTIVE ZONAL FLOW CONTINUES WITH THUNDER CHANCES SATURDAY AND SUNDAY...MAINLY DURING THE AFTERNOON HOURS. ON SATURDAY THERE WILL BE A WEAK LOW LEVEL BOUNDARY AND A MARGINAL CHANCE FOR SEVERE THUNDERSTORMS DURING PEAK HEATING (GIVEN WEAK INSTABILITY AND MARGINAL DEEP LAYER SHEAR). ON SUNDAY...SEVERE CHANCES APPEAR BETTER GIVEN A STRONGER UPPER LEVEL WAVE...ALTHOUGH MUCH WILL DEPEND ON TIMING OF THIS FEATURE. HIGH PRESSURE ON MONDAY SHOULD LEAD TO DRY WEATHER. MONDAY NIGHT-FRIDAY...GOOD AGREEMENT BETWEEN THE GFS AND ECMWF IN THE EXTENDED AS LATE WEEKEND WAVE HAS PUSHED WELL EAST OF FORECAST AREA AND IS REPLACED BY ZONAL FLOW TO START EXTENDED PERIOD. SEVERAL SHORT WAVES MOVING THROUGH THIS REGIME WILL CREATE THUNDER CHANCES...WITH PLENTY OF DRY INTERVALS MIXED IN. IN TERMS OF A PROBABILITY FORECAST WE ARE KIND OF LEFT WITH LOW CHANCE POPS FOR ESSENTIALLY THE ENTIRE TIME THROUGH FRIDAY. HOWEVER THE BEST SIGNAL FOR PCPN CHANCES COMES DURING THE WEDNESDAY INTO WEDNESDAY NIGHT BLOCK OF TIME. NEAR NORMAL TEMPERATURES ARE IN THE OFFING FOR NEXT WEEK WITH HIGHS MOSTLY IN THE UPPER 70S WHILE LOWS DROP TO BETWEEN 55 AND 60. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1150 PM CDT FRI JUN 19 2015 CONVECTION HAS MOVED INTO THE FORECAST AREA...WITH VCTS AT KGFK KFAR AND KTVF AT THE START OF THE 06Z TAF PERIOD. STORMS WILL MOVE INTO THE KBJI AREA BEFORE DAYBREAK. THE PRECIP WILL CLEAR OUT DURING THE MORNING HOURS...BUT SOME MVFR CIGS AND EVEN SOME LIGHT BR WILL BE POSSIBLE BEHIND IT TOWARDS DAYBREAK. THINK THE 1500-3000 FT CIGS WILL HANG AROUND THROUGH MUCH OF THE MORNING...THEN CONDITIONS WILL BECOME VFR BY AFTERNOON. LIGHT NORTH WINDS ACROSS ALL BUT KFAR WITH A FRONTAL BOUNDARY OVER THE AREA. WINDS WILL SHIFT AT KFAR LATER THIS MORNING AND ALL SITES WILL SEE NORTH TO NORTHWEST WINDS BELOW 12 KTS. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...JR SHORT TERM...TG LONG TERM...WJB/TG AVIATION...JR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
951 PM CDT FRI JUN 19 2015 .UPDATE... ISSUED AT 951 PM CDT FRI JUN 19 2015 STORMS OVER THE WESTERN PART OF ND HAVE EVOLVED INTO A MCS CURRENTLY MOVING THROUGH THE EASTERN PART OF BIS CWA. SUBSIDENCE HAS KEPT CONVECTION ALONG THE FRONT INTO THE RED RIVER VALLEY SUPPRESSED...BUT ACTIVITY SHOULD BE INCREASING AS THE MCS MOVES INTO EASTERN ND. THERE IS STILL A GOOD AMOUNT OF INSTABILITY TO WORK WITH...AND WILL HAVE TO WATCH HOW IT INTERACTS WITH THE FRONTAL BOUNDARY CURRENTLY ACROSS THE CENTRAL CWA. THINK THAT THE BEST SEVERE CHANCES WILL BE ACROSS THE SOUTHERN CWA WHICH FITS THE TRACK OF THE BOW...SO KEPT SEVERE T MENTION THERE BUT AT THIS POINT IT SEEMS THE DEVILS LAKE BASIN WILL NOT GET MUCH WIND OR HAIL SO REMOVED SEVERE WORDING THERE. UPDATE ISSUED AT 652 PM CDT FRI JUN 19 2015 SOME CU AND SHOWERS HAVE TRIED TO GO UP ALONG THE FRONTAL BOUNDARY DRAPED FROM COOPERSTOWN TO GRAFTON TO THE LAKE OF THE WOODS AREA. OVER OUR NORTHEASTERN COUNTIES THERE HAS BEEN SOME ONGOING ACTIVITY ON THE NOSE OF THE LOW LEVEL JET...BUT FURTHER WEST CELLS HAVE STRUGGLED UNDER THE SUBSIDENCE ON THE BACKSIDE OF A DEPARTING SHORTWAVE TROUGH. DO NOT THINK WE WILL SEE MUCH UNTIL THE NEXT SHORTWAVE COMES OUT OF MONTANA LATER TONIGHT. HAVE SOME POPS COMING INTO OUR WEST AROUND 03Z...ALONG WITH ONGOING POPS IN THE NORTHEASTERN CORNER. CONVECTION SHOULD PICK UP LATER TONIGHT AS WE GET THE SHORTWAVE COMING OUT. KEPT HIGHEST POPS IN THE SOUTH FOR NOW BUT WILL ADJUST AS NEEDED DEPENDING ON HOW THE STORMS JUST MOVING INTO WESTERN ND BEHAVE. && .SHORT TERM...(THIS EVENING AND OVERNIGHT) ISSUED AT 315 PM CDT FRI JUN 19 2015 LATEST GUIDANCE AND OBSERVATIONS AGREE WITH PREVIOUS THINKING. SFC BOUNDARY WITH MLCAPE 1000-1500 J/KG HAS SET UP FROM SW ND INTO THE GRAND FORKS AREA. THIS REGION IS CURRENTLY ON THE SUBSIDENCE SIDE OF A DEPARTING SHORTWAVE...WHICH WILL LIKELY SUPPRESS CONVECTION FOR A FEW MORE HOURS. STRONGER SYNOPTIC FORCING ARRIVES THIS EVENING...SPREADING ACTIVITY INTO THE REGION. LATEST CAM GUIDANCE CONTINUES TO SUGGEST STRONGEST STORMS WILL BE ACROSS SOUTH DAKOTA (STRONGEST FORCING ON NOSE OF THE LOW LEVEL JET...INSTABILITY..ETC). HOWEVER...THERE WILL BE A SEVERE THREAT ACROSS SOUTHEAST NORTH DAKOTA INTO WEST CENTRAL MINNESOTA DURING THE 03Z-09Z PERIOD WITH FORCING FROM A MORE NORTHERN UPPER WAVE OVERRIDING THE REGION. GUIDANCE SUGGESTS THIS FORCING WILL INTERACT WITH MUCAPE 1000-1500 J/KG AND 35-45 KNOTS DEEP LAYER SHEAR. HRRR SUGGESTS A FEW STRONGER STORMS WILL BE POSSIBLE WITHIN THIS ENVIRONMENT (MARGINALLY LARGE HAIL WITH MARGINALLY SEVERE WIND GUSTS THE LIKELY THREATS...TORNADO THREAT APPEARS LOW GIVEN WEAK 0-3KM BULK SHEAR DURING THIS TIMEFRAME). SEVERE THREAT WOULD APPEAR TO QUICKLY DROP TOWARD THE INTERNATIONAL BORDER AS THE SOUTHERN ACTIVITY DOMINATES THE SCENE. WILL ALSO NEED TO WATCH FOR HEAVY RAIN AND FLASH FLOOD POTENTIAL IF A WEST TO EAST BOUNDARY (AND TRAINING STORMS) SETS UP NEAR THE SOUTHERN FA. THIS IS A POSSIBILITY...BUT A LOW PROBABILITY GIVEN THE STRONGER SYSTEM EXPECTED ACROSS SOUTH DAKOTA. .LONG TERM...(SATURDAY THROUGH FRIDAY) ISSUED AT 315 PM CDT FRI JUN 19 2015 SATURDAY-MONDAY...ACTIVE ZONAL FLOW CONTINUES WITH THUNDER CHANCES SATURDAY AND SUNDAY...MAINLY DURING THE AFTERNOON HOURS. ON SATURDAY THERE WILL BE A WEAK LOW LEVEL BOUNDARY AND A MARGINAL CHANCE FOR SEVERE THUNDERSTORMS DURING PEAK HEATING (GIVEN WEAK INSTABILITY AND MARGINAL DEEP LAYER SHEAR). ON SUNDAY...SEVERE CHANCES APPEAR BETTER GIVEN A STRONGER UPPER LEVEL WAVE...ALTHOUGH MUCH WILL DEPEND ON TIMING OF THIS FEATURE. HIGH PRESSURE ON MONDAY SHOULD LEAD TO DRY WEATHER. MONDAY NIGHT-FRIDAY...GOOD AGREEMENT BETWEEN THE GFS AND ECMWF IN THE EXTENDED AS LATE WEEKEND WAVE HAS PUSHED WELL EAST OF FORECAST AREA AND IS REPLACED BY ZONAL FLOW TO START EXTENDED PERIOD. SEVERAL SHORT WAVES MOVING THROUGH THIS REGIME WILL CREATE THUNDER CHANCES...WITH PLENTY OF DRY INTERVALS MIXED IN. IN TERMS OF A PROBABILITY FORECAST WE ARE KIND OF LEFT WITH LOW CHANCE POPS FOR ESSENTIALLY THE ENTIRE TIME THROUGH FRIDAY. HOWEVER THE BEST SIGNAL FOR PCPN CHANCES COMES DURING THE WEDNESDAY INTO WEDNESDAY NIGHT BLOCK OF TIME. NEAR NORMAL TEMPERATURES ARE IN THE OFFING FOR NEXT WEEK WITH HIGHS MOSTLY IN THE UPPER 70S WHILE LOWS DROP TO BETWEEN 55 AND 60. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING) ISSUED AT 652 PM CDT FRI JUN 19 2015 VFR CONDITIONS CONTINUE AS CU STRUGGLES TO GET GOING ACROSS PORTIONS OF THE FORECAST AREA. THINK THAT THE TAF SITES WILL NOT SEE MUCH CONVECTION UNTIL LATER TONIGHT...SO MOVED THE VCTS MENTION UNTIL 03Z FOR KDVL AND EVEN LATER FOR THE EASTERN SITES. SHOULD BE A TRANSITION TO MORE SHOWERS DURING THE EARLY MORNING HOURS...WITH SOME MVFR CIGS DEVELOPING. SOME 3-5SM BR IS NOT OUT OF THE QUESTION BUT WILL KEEP VIS ABOVE 6SM FOR NOW. THE MVFR CIGS WILL CONTINUE FOR A TIME SATURDAY MORNING BEFORE IMPROVING TO VFR BY AFTERNOON. WINDS WILL BE TRICKY WITH A COLD FRONT STALLED ACROSS THE REGION THIS EVENING. KDVL HAS ALREADY SHIFTED TO THE NORTH AND THE OTHER TAF SITES SHOULD SEE A WIND SHIFT LATER TONIGHT AS THE BOUNDARY FINALLY BEGINS TO PUSH SOUTH AND EAST. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...JR SHORT TERM...TG LONG TERM...WJB/TG AVIATION...JR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
652 PM CDT FRI JUN 19 2015 .UPDATE... ISSUED AT 652 PM CDT FRI JUN 19 2015 SOME CU AND SHOWERS HAVE TRIED TO GO UP ALONG THE FRONTAL BOUNDARY DRAPPED FROM COOPERSTOWN TO GRAFTON TO THE LAKE OF THE WOODS AREA. OVER OUR NORTHEASTERN COUNTIES THERE HAS BEEN SOME ONGOING ACTIVITY ON THE NOSE OF THE LOW LEVEL JET...BUT FURTHER WEST CELLS HAVE STRUGGLED UNDER THE SUBSIDENCE ON THE BACKSIDE OF A DEPARTING SHORTWAVE TROUGH. DO NOT THINK WE WILL SEE MUCH UNTIL THE NEXT SHORTWAVE COMES OUT OF MONTANA LATER TONIGHT. HAVE SOME POPS COMING INTO OUR WEST AROUND 03Z...ALONG WITH ONGOING POPS IN THE NORTHEASTERN CORNER. CONVECTION SHOULD PICK UP LATER TONIGHT AS WE GET THE SHORTWAVE COMING OUT. KEPT HIGHEST POPS IN THE SOUTH FOR NOW BUT WILL ADJUST AS NEEDED DEPENDING ON HOW THE STORMS JUST MOVING INTO WESTERN ND BEHAVE. && .SHORT TERM...(THIS EVENING AND OVERNIGHT) ISSUED AT 315 PM CDT FRI JUN 19 2015 LATEST GUIDANCE AND OBSERVATIONS AGREE WITH PREVIOUS THINKING. SFC BOUNDARY WITH MLCAPE 1000-1500 J/KG HAS SET UP FROM SW ND INTO THE GRAND FORKS AREA. THIS REGION IS CURRENTLY ON THE SUBSIDENCE SIDE OF A DEPARTING SHORTWAVE...WHICH WILL LIKELY SUPPRESS CONVECTION FOR A FEW MORE HOURS. STRONGER SYNOPTIC FORCING ARRIVES THIS EVENING...SPREADING ACTIVITY INTO THE REGION. LATEST CAM GUIDANCE CONTINUES TO SUGGEST STRONGEST STORMS WILL BE ACROSS SOUTH DAKOTA (STRONGEST FORCING ON NOSE OF THE LOW LEVEL JET...INSTABILITY..ETC). HOWEVER...THERE WILL BE A SEVERE THREAT ACROSS SOUTHEAST NORTH DAKOTA INTO WEST CENTRAL MINNESOTA DURING THE 03Z-09Z PERIOD WITH FORCING FROM A MORE NORTHERN UPPER WAVE OVERRIDING THE REGION. GUIDANCE SUGGESTS THIS FORCING WILL INTERACT WITH MUCAPE 1000-1500 J/KG AND 35-45 KNOTS DEEP LAYER SHEAR. HRRR SUGGESTS A FEW STRONGER STORMS WILL BE POSSIBLE WITHIN THIS ENVIRONMENT (MARGINALLY LARGE HAIL WITH MARGINALLY SEVERE WIND GUSTS THE LIKELY THREATS...TORNADO THREAT APPEARS LOW GIVEN WEAK 0-3KM BULK SHEAR DURING THIS TIMEFRAME). SEVERE THREAT WOULD APPEAR TO QUICKLY DROP TOWARD THE INTERNATIONAL BORDER AS THE SOUTHERN ACTIVITY DOMINATES THE SCENE. WILL ALSO NEED TO WATCH FOR HEAVY RAIN AND FLASH FLOOD POTENTIAL IF A WEST TO EAST BOUNDARY (AND TRAINING STORMS) SETS UP NEAR THE SOUTHERN FA. THIS IS A POSSIBILITY...BUT A LOW PROBABILITY GIVEN THE STRONGER SYSTEM EXPECTED ACROSS SOUTH DAKOTA. .LONG TERM...(SATURDAY THROUGH FRIDAY) ISSUED AT 315 PM CDT FRI JUN 19 2015 SATURDAY-MONDAY...ACTIVE ZONAL FLOW CONTINUES WITH THUNDER CHANCES SATURDAY AND SUNDAY...MAINLY DURING THE AFTERNOON HOURS. ON SATURDAY THERE WILL BE A WEAK LOW LEVEL BOUNDARY AND A MARGINAL CHANCE FOR SEVERE THUNDERSTORMS DURING PEAK HEATING (GIVEN WEAK INSTABILITY AND MARGINAL DEEP LAYER SHEAR). ON SUNDAY...SEVERE CHANCES APPEAR BETTER GIVEN A STRONGER UPPER LEVEL WAVE...ALTHOUGH MUCH WILL DEPEND ON TIMING OF THIS FEATURE. HIGH PRESSURE ON MONDAY SHOULD LEAD TO DRY WEATHER. MONDAY NIGHT-FRIDAY...GOOD AGREEMENT BETWEEN THE GFS AND ECMWF IN THE EXTENDED AS LATE WEEKEND WAVE HAS PUSHED WELL EAST OF FORECAST AREA AND IS REPLACED BY ZONAL FLOW TO START EXTENDED PERIOD. SEVERAL SHORT WAVES MOVING THROUGH THIS REGIME WILL CREATE THUNDER CHANCES...WITH PLENTY OF DRY INTERVALS MIXED IN. IN TERMS OF A PROBABILITY FORECAST WE ARE KIND OF LEFT WITH LOW CHANCE POPS FOR ESSENTIALLY THE ENTIRE TIME THROUGH FRIDAY. HOWEVER THE BEST SIGNAL FOR PCPN CHANCES COMES DURING THE WEDNESDAY INTO WEDNESDAY NIGHT BLOCK OF TIME. NEAR NORMAL TEMPERATURES ARE IN THE OFFING FOR NEXT WEEK WITH HIGHS MOSTLY IN THE UPPER 70S WHILE LOWS DROP TO BETWEEN 55 AND 60. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING) ISSUED AT 652 PM CDT FRI JUN 19 2015 VFR CONDITIONS CONTINUE AS CU STRUGGLES TO GET GOING ACROSS PORTIONS OF THE FORECAST AREA. THINK THAT THE TAF SITES WILL NOT SEE MUCH CONVECTION UNTIL LATER TONIGHT...SO MOVED THE VCTS MENTION UNTIL 03Z FOR KDVL AND EVEN LATER FOR THE EASTERN SITES. SHOULD BE A TRANSITION TO MORE SHOWERS DURING THE EARLY MORNING HOURS...WITH SOME MVFR CIGS DEVELOPING. SOME 3-5SM BR IS NOT OUT OF THE QUESTION BUT WILL KEEP VIS ABOVE 6SM FOR NOW. THE MVFR CIGS WILL CONTINUE FOR A TIME SATURDAY MORNING BEFORE IMPROVING TO VFR BY AFTERNOON. WINDS WILL BE TRICKY WITH A COLD FRONT STALLED ACROSS THE REGION THIS EVENING. KDVL HAS ALREADY SHIFTED TO THE NORTH AND THE OTHER TAF SITES SHOULD SEE A WIND SHIFT LATER TONIGHT AS THE BOUNDARY FINALLY BEGINS TO PUSH SOUTH AND EAST. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...JR SHORT TERM...TG LONG TERM...WJB/TG AVIATION...JR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
315 PM CDT FRI JUN 19 2015 .SHORT TERM...(THIS EVENING AND OVERNIGHT) ISSUED AT 315 PM CDT FRI JUN 19 2015 LATEST GUIDANCE AND OBSERVATIONS AGREE WITH PREVIOUS THINKING. SFC BOUNDARY WITH MLCAPE 1000-1500 J/KG HAS SET UP FROM SW ND INTO THE GRAND FORKS AREA. THIS REGION IS CURRENTLY ON THE SUBSIDENCE SIDE OF A DEPARTING SHORTWAVE...WHICH WILL LIKELY SUPPRESS CONVECTION FOR A FEW MORE HOURS. STRONGER SYNOPTIC FORCING ARRIVES THIS EVENING...SPREADING ACTIVITY INTO THE REGION. LATEST CAM GUIDANCE CONTINUES TO SUGGEST STRONGEST STORMS WILL BE ACROSS SOUTH DAKOTA (STRONGEST FORCING ON NOSE OF THE LOW LEVEL JET...INSTABILITY..ETC). HOWEVER...THERE WILL BE A SEVERE THREAT ACROSS SOUTHEAST NORTH DAKOTA INTO WEST CENTRAL MINNESOTA DURING THE 03Z-09Z PERIOD WITH FORCING FROM A MORE NORTHERN UPPER WAVE OVERRIDING THE REGION. GUIDANCE SUGGESTS THIS FORCING WILL INTERACT WITH MUCAPE 1000-1500 J/KG AND 35-45 KNOTS DEEP LAYER SHEAR. HRRR SUGGESTS A FEW STRONGER STORMS WILL BE POSSIBLE WITHIN THIS ENVIRONMENT (MARGINALLY LARGE HAIL WITH MARGINALLY SEVERE WIND GUSTS THE LIKELY THREATS...TORNADO THREAT APPEARS LOW GIVEN WEAK 0-3KM BULK SHEAR DURING THIS TIMEFRAME). SEVERE THREAT WOULD APPEAR TO QUICKLY DROP TOWARD THE INTERNATIONAL BORDER AS THE SOUTHERN ACTIVITY DOMINATES THE SCENE. WILL ALSO NEED TO WATCH FOR HEAVY RAIN AND FLASH FLOOD POTENTIAL IF A WEST TO EAST BOUNDARY (AND TRAINING STORMS) SETS UP NEAR THE SOUTHERN FA. THIS IS A POSSIBILITY...BUT A LOW PROBABILITY GIVEN THE STRONGER SYSTEM EXPECTED ACROSS SOUTH DAKOTA. .LONG TERM...(SATURDAY THROUGH FRIDAY) ISSUED AT 315 PM CDT FRI JUN 19 2015 SATURDAY-MONDAY...ACTIVE ZONAL FLOW CONTINUES WITH THUNDER CHANCES SATURDAY AND SUNDAY...MAINLY DURING THE AFTERNOON HOURS. ON SATURDAY THERE WILL BE A WEAK LOW LEVEL BOUNDARY AND A MARGINAL CHANCE FOR SEVERE THUNDERSTORMS DURING PEAK HEATING (GIVEN WEAK INSTABILITY AND MARGINAL DEEP LAYER SHEAR). ON SUNDAY...SEVERE CHANCES APPEAR BETTER GIVEN A STRONGER UPPER LEVEL WAVE...ALTHOUGH MUCH WILL DEPEND ON TIMING OF THIS FEATURE. HIGH PRESSURE ON MONDAY SHOULD LEAD TO DRY WEATHER. MONDAY NIGHT-FRIDAY...GOOD AGREEMENT BETWEEN THE GFS AND ECMWF IN THE EXTENDED AS LATE WEEKEND WAVE HAS PUSHED WELL EAST OF FORECAST AREA AND IS REPLACED BY ZONAL FLOW TO START EXTENDED PERIOD. SEVERAL SHORT WAVES MOVING THROUGH THIS REGIME WILL CREATE THUNDER CHANCES...WITH PLENTY OF DRY INTERVALS MIXED IN. IN TERMS OF A PROBABILITY FORECAST WE ARE KIND OF LEFT WITH LOW CHANCE POPS FOR ESSENTIALLY THE ENTIRE TIME THROUGH FRIDAY. HOWEVER THE BEST SIGNAL FOR PCPN CHANCES COMES DURING THE WEDNESDAY INTO WEDNESDAY NIGHT BLOCK OF TIME. NEAR NORMAL TEMPERATURES ARE IN THE OFFING FOR NEXT WEEK WITH HIGHS MOSTLY IN THE UPPER 70S WHILE LOWS DROP TO BETWEEN 55 AND 60. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 105 PM CDT FRI JUN 19 2015 THE MAIN CHALLENGE WILL BE RETURN OF SHOWERS AND THUNDERSTORMS LATER THIS AFTERNOON INTO TONIGHT. THIS DEPENDS LARGELY ON ORIENTATION AND MOVEMENT OF SFC BOUNDARY. INTRODUCED -TSRA TO ALL SITES AT OR AFTER 00Z TRENDING TO SHRA OVERNIGHT. MVFR CONDS TO ACCOMPANY TSRA AND LINGER INTO SAT MORNING. SOUTH WINDS WILL SHIFT TO NORTH WHEN BOUNDARY SINKS TO THE SOUTH THIS EVENING OR OVERNIGHT. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ SHORT TERM...TG LONG TERM...WJB/TG AVIATION...WJB
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
105 PM CDT FRI JUN 19 2015 .UPDATE... ISSUED AT 105 PM CDT FRI JUN 19 2015 LATEST GUIDANCE CONTINUES TO TREND WITH THE IDEA THAT THE SEVERE THREAT ACROSS EASTERN NORTH DAKOTA WILL BE MORE TOWARD 03Z...AND CLOSER TO 05Z/06Z INTO THE VALLEY. ATMOSPHERE REMAINS STABLE ACROSS EASTERN NORTH DAKOTA AT 18Z...AND WILL LIKELY NOT BE UNSTABLE ENOUGH (CAPPING ISSUES) FOR STORMS TO FORM ALONG THE SFC BOUNDARY THIS AFTERNOON...WAITING FOR THE STRONGER SYNOPTIC FORCING TO OVERRIDE THE REGION CLOSER TO 03Z. LATEST CAM GUIDANCE CONTINUES TO SUGGEST STRONGEST STORMS WILL BE ACROSS SOUTH DAKOTA (STRONGEST FORCING ON NOSE OF THE LOW LEVEL JET...INSTABILITY..ETC). HOWEVER...THERE WILL BE A SEVERE THREAT ACROSS SOUTHEAST NORTH DAKOTA INTO WEST CENTRAL MINNESOTA DURING THE 03Z-09Z PERIOD WITH FORCING FROM A MORE NORTHERN UPPER WAVE OVERRIDING THE REGION. GUIDANCE SUGGESTS THIS FORCING WILL INTERACT WITH MUCAPE 1000-1500 J/KG AND 35-45 KNOTS DEEP LAYER SHEAR. HRRR SUGGESTS A FEW STRONGER STORMS WILL BE POSSIBLE WITHIN THIS ENVIRONMENT (MARGINALLY LARGE HAIL WITH MARGINALLY SEVERE WIND GUSTS THE LIKELY THREATS...TORNADO THREAT APPEARS LOW GIVEN WEAK 0-3KM BULK SHEAR DURING THIS TIMEFRAME). ADJUSTED THE FORECAST TO THE ABOVE THINKING. SEVERE THREAT WOULD APPEAR TO QUICKLY DROP TOWARD THE INTERNATIONAL BORDER AS THE SOUTHERN ACTIVITY DOMINATES THE SCENE. UPDATE ISSUED AT 1001 AM CDT FRI JUN 19 2015 UPPER WAVE EVIDENT ON WATER VAPOR IMAGERY ACROSS CENTRAL NORTH DAKOTA INDUCING 850MB LOW LEVEL JET AND ENHANCED REGION OF 850MB WARM AIR ADVECTION...WITH ASSOCIATED RADAR RETURNS ACROSS NE ND AND NW MN. LATEST GUIDANCE INDICATES THIS FORCING WILL CONTINUE TO PROPAGATE TO THE EAST/NORTHEAST THROUGH THE DAY. INCREASED POPS FOR THIS AREA OF SHOWERS/ISOLD THUNDER ACTIVITY (FOLLOWING THE LATEST HRRR FOR TIMING). LIGHTNING ACTIVITY IS DECREASING...A SIGN THAT THIS FORCING IS OUTRUNNING INSTABILITY. THERE WILL BE A PERIOD OF DRY WEATHER BEHIND THIS SYSTEM...IN AN AREA OF SUBSIDENCE BEHIND THE SHORTWAVE...EVIDENT FROM SATELLITE IMAGERY. MAJOR QUESTIONS FOR SEVERE POTENTIAL THIS AFTERNOON/EVENING WILL BE DEVELOPMENT ALONG THE SFC BOUNDARY/WARM FRONT...AND THEN HOW FAR NORTH WILL THE MCS THAT DEVELOPMENTS ACROSS THE WESTERN DAKOTAS TRACK OVERNIGHT. LATEST SYNOPTIC MODELS AND CAM GUIDANCE TRENDING TOWARD MINIMAL DEVELOPMENT ALONG THE SFC BOUNDARY (DUE TO CAPPING ISSUES). THIS SFC BOUNDARY (WARM FRONT) WILL BE POSITIONED FROM SOUTHWEST NORTH DAKOTA INTO NORTHEAST NORTH DAKOTA. SYNOPTIC FORCING (FROM A STRONGER UPPER LEVEL WAVE) WILL BE DELAYED UNTIL CLOSER TO 03Z. THUS...LIKE THE IDEA OF POSSIBLY ISOLD STORMS CLOSER TO 00Z ALONG THE SFC BOUNDARY (AND POSSIBLY NO STORMS). ADJUSTED POPS AND DELAYED T+ MENTION UNTIL 00Z. AS THE SYNOPTIC FORCING OVERRIDES THE REGION...THINKING THAT THUNDERSTORM COVERAGE WILL INCREASE...INCREASING SEVERE POTENTIAL. THERE WILL ALSO BE THE MCS THAT INITIATES ACROSS THE WESTERN DAKOTAS...AND NOT SURE THE AFFECT THIS WILL HAVE ON ACTIVITY TO THE NORTH...OR WHERE THIS SYSTEM WILL TRACK (MAY AFFECT THE SOUTHERN FA). WILL CONTINUE TO MONITOR AND HOPEFULLY HAVE MORE DETAILS WITH THE 1PM UPDATE. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 330 AM CDT FRI JUN 19 2015 A BAND OF ELEVATED CONVECTION IS FORMING IN CENTRAL INTO NE ND EARLY THIS MORNING THE HRRR AND OTHER CAM MODELS HAVE THIS WELL IN HAND...AND EXPECT THIS CONVECTION TO CONTINUE TO MOVE/DEVELOP INTO THE DEVILS LAKE BASIN INTO THE NORTHERN VALLEY THROUGH THIS MORNING. MODELS ARE IN GOOD OVERALL AGREEMENT WITH LARGE SCALE FEATURES THROUGH THE PERIOD. THE EXACT DETAILS ARE ALWAYS CHALLENGING WITH CONVECTION...SO THIS WILL NEED TO BE IRONED OUT OVER THE NEXT SEVERAL DAYS. FOR TODAY AND TONIGHT...EXPECT A FAIRLY LARGE AREA OF ELEVATED CONVECTION THROUGH THE MORNING IN THE NORTH. THERE WILL BE INCREASING INSTABILITY THROUGH THE DAY ALONG AND WEST OF THE VALLEY. MODELS HINT AT SOME RE-DEVELOPMENT IN THE NORTH AND WESTERN FORECAST AREA THIS AFTERNOON...WITH SFC CAPE AROUND 2000 J/KG. IT APPEARS THAT THE MAIN CONVECTION WILL DEVELOP OVER THE WESTERN DAKOTAS LATER THIS AFTERNOON/EVENING...ALTHOUGH ANY AREAS THAT HEAT OUT TODAY WITH TDS INCREASING WILL HAVE TO BE WATCHED. DEEP LAYERED SHEAR THROUGH TONIGHT WILL BE STRONG...AROUND 50KT...SO ANY STORMS THAT FORM IN THE SLIGHT RISK AREA COULD BE SUPERCELLULAR INITIALLY. THERE SHOULD BE A LARGER SEVERE TYPE MCS MOVING FROM THE WESTERN DAKOTAS INTO THE SOUTHERN VALLEY...OR VERY CLOSE...LATER TONIGHT FROM 6Z-12Z. THIS WILL BE FED BY A STRONG LLJ AROUND 50KT AND PWATS APPROACHING 2 INCHES ON THE GFS AND NAM. WILL MENTION SEVERE IN THE SLIGHT RISK AREA 18Z-06Z...THEN IN THE SOUTHERN FA 6Z-12Z WITH SOME HEAVY RAIN POSSIBLE HERE ALSO. FOR SATURDAY...THERE WILL BE INSTABILITY BY AFTERNOON WITH ANOTHER SHORTWAVE MOVING THROUGH ACTIVE W/NW FLOW ALOFT. THE OVERALL LACK OF STRONGER FORCING/CONVERGENCE SHOULD LEAD TO ISOLATED COVERAGE FOR ANY AFTERNOON STORMS. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 330 AM CDT FRI JUN 19 2015 ON SUNDAY...A STRONG SHORTWAVE WILL APPROACH THE WESTERN FORECAST AREA BY AFTERNOON. THERE WILL BE ABOUT 1500 J/KG OF SFC CAPE AHEAD OF THE WAVE...AND STRONG DEEP SHEAR AROUND 55KT. THE MAIN THING WILL BE TIMING OF THE SHORTWAVE...AND SPC HAS INTRODUCED A MARGINAL RISK FOR SEVERE WEATHER IN THE RED RIVER VALLEY FOR FATHERS DAY. MONDAY TO THURSDAY...GOOD AGREEMENT IN THE EXTENDED WITH ZONAL TO NW FLOW ALOFT WITH PERIODIC SHORT WAVES AND FROPAS PUSHING ACROSS THE AREA. TIMING AND PLACEMENT OF THESE WAVES WITH WHERE AND WHEN TO INCREASE OR DECREASE POPS IS TOO UNCERTAIN OTHER THAN MAKE A CHC MENTION FOR MOST OF THE AREAS EVERYDAY IN THE EXTENDED. THE EXCEPTION IS MONDAY WITH A DRY DAY EXPECTED AS A WEAK SFC HIGH IS PROGGED TO MOVE ACROSS THE AREA. NEAR NORMAL TEMPERATURES NEXT WEEK WITH UPP70S TO NEAR 80 FOR HIGHS AND LOWS IN THE UPPER 50S TO LOW 60S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 105 PM CDT FRI JUN 19 2015 THE MAIN CHALLENGE WILL BE RETURN OF SHOWERS AND THUNDERSTORMS LATER THIS AFTERNOON INTO TONIGHT. THIS DEPENDS LARGELY ON ORIENTATION AND MOVEMENT OF SFC BOUNDARY. INTRODUCED -TSRA TO ALL SITES AT OR AFTER 00Z TRENDING TO SHRA OVERNIGHT. MVFR CONDS TO ACCOMPANY TSRA AND LINGER INTO SAT MORNING. SOUTH WINDS WILL SHIFT TO NORTH WHEN BOUNDARY SINKS TO THE SOUTH THIS EVENING OR OVERNIGHT. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...TG SHORT TERM...DK LONG TERM...JK/DK AVIATION...WJB
AREA FORECAST DISCUSSION
NWS BISMARCK ND
100 PM CDT FRI JUN 19 2015 .UPDATE... ISSUED AT 1258 PM CDT FRI JUN 19 2015 LITTLE CHANGE FROM THE PREVIOUS FORECAST UPDATE REGARDING TIMING AND THREATS AS SUPPORTED BY 14-16 UTC HRRR ITERATIONS AND THE FULL 12 UTC DETERMINISTIC SUITE. ONGOING FORECAST BLENDED TO OBSERVED TRENDS THROUGH 17 UTC. UPDATE ISSUED AT 946 AM CDT FRI JUN 19 2015 THE 11-13 UTC HRRR ITERATIONS...00 UTC SPC WRF AND 12 UTC NAM ARE IN GOOD AGREEMENT REGARDING THE POTENTIAL EVOLUTION OF THE SEVERE CONVECTIVE EVENT LATE THIS AFTERNOON AND THROUGH THE EVENING. THE CONSENSUS IS FOR POTENTIAL SUPERCELLS TO INITIATE OR CROSS INTO FAR WESTERN NORTH DAKOTA AROUND 22 UTC WITH THE ARRIVAL OF MULTIPLE IMPULSES EMBEDDED IN THE FAST WESTERLIES ALOFT. 2000-2500 J/KG OF ML CAPE AND STRONG DEEP LAYER SHEAR OF 40-50 KTS GENERALLY SOUTH OF ND HIGHWAY 200 SUPPORTS SUPERCELLS WITH LARGE HAIL AND DAMAGING WINDS THE PRIMARY THREATS. WHILE LOW LEVEL SHEAR IS WEAK AND LCLS A BIT HIGH...CERTAINLY CANNOT RULE OUT A TORNADO OR TWO GIVEN DISCRETE SUPERCELLS TO BEGIN THE EVENT. CONGEALING OF STORMS INTO A POSSIBLE MCS IS STILL FAVORED LATE THIS EVENING ACROSS NORTH CENTRAL SOUTH DAKOTA INTO SOUTH CENTRAL NORTH DAKOTA. ACROSS NORTHERN NORTH DAKOTA...LOW LEVEL STRATUS THIS MORNING MAY HELP TO LIMIT THE OVERALL SEVERE THREAT FOR TODAY. UPDATE ISSUED AT 631 AM CDT FRI JUN 19 2015 ONGOING ELEVATED CONVECTION OVER NORTH CENTRAL NORTH DAKOTA WILL CONTINUE TO TRACK EASTWARD THIS MORNING. RAISED POPS NORTH CENTRAL THIS MORNING...AND UPDATED POPS BASED ON LATEST RADAR TRENDS. OTHERWISE NO SIGNIFICANT CHANGES TO THE GOING FORECAST. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 253 AM CDT FRI JUN 19 2015 THE MAIN FOCUS FOR THE SHORT TERM IS SEVERE STORMS THIS AFTERNOON AND EVENING. EARLY THIS MORNING A COMPLEX OF SEVERE STORMS WAS MOVING ACROSS NORTHWESTERN SOUTH DAKOTA. THIS SHOULD STAY SOUTH OF NORTH DAKOTA. LOCATIONS ALONG THE ND/SD BORDER COULD SEE SOME LIGHT RAIN AND LIGHTNING...BUT THE MAIN STORM WILL BE FURTHER SOUTH. OTHERWISE...SCATTERED THUNDERSTORMS WERE RAPIDLY FORMING ACROSS NORTHERN NORTH DAKOTA ON THE NOSE OF A POTENT LOW LEVEL JET. THIS ACTIVITY WAS PICKED UP WELL BY THE HRRR AND IS EXPECTED TO CONTINUE ACROSS THE NORTH THROUGH THE EARLY MORNING HOURS. THIS EARLY MORNING CONVECTION IS NOT EXPECTED TO DIMINISH SEVERE CHANCES LATER THIS AFTERNOON AS SKIES SHOULD CLEAR AND LEAD TO PLENTY OF AFTERNOON HEATING. GENERAL MODEL CONSENSUS INDICATES THUNDERSTORM DEVELOPMENT BY LATE THIS AFTERNOON ACROSS WESTERN NORTH DAKOTA. INITIAL STORMS COULD RAPIDLY INTENSIFY AND BECOME SUPERCELLULAR WITH 2K+ CAPE...50 KNOTS OF 0-6 KM SHEAR...STEEP LAPSE RATES AND AMPLE FORCING PROVIDED BY A SURFACE LOW AND APPROACHING UPPER-LEVEL SHORTWAVE TROUGH. INITIAL THREATS WITH THESE STORMS WOULD BE VERY LARGE HAIL...A FEW TORNADOES...VERY HEAVY RAIN AND DAMAGING WIND. CONVECTIVE MODELS (WRFS) THEN INDICATE MERGING OF CELLS INTO A LINE SEGMENT ACROSS CENTRAL AND SOUTHERN NORTH DAKOTA. THERE IS SOME UNCERTAINTY AS TO WHERE EXACTLY THIS POTENTIAL LINE WOULD DEVELOP/MOVE. THE NSSL WRF SHOWS THE BULK OF THE LINE QUICKLY DIVING INTO SOUTH DAKOTA...FOLLOWING A SIMILAR TRACK TO THE THIS EARLY MORNING`S COMPLEX. DAMAGING WINDS WOULD BE THE MAIN THREAT WITH AN EVENING/OVERNIGHT SQUALL LINE. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 253 AM CDT FRI JUN 19 2015 DETERMINISTIC AND ENSEMBLE GUIDANCE CONTINUES TO SUGGEST AN ACTIVE PATTERN TO CONTINUE THROUGH THE EXTENDED PERIOD. ON SATURDAY...A NEARLY ZONAL FLOW OVER THE FORECAST AREA WILL CONTINUE TO PROVIDE SUPPORT FOR ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS. 19 JUN 00 UTC ECMWF/GFS MODEL GUIDANCE DEPICTS 20 TO 40 KNOTS OF BULK SHEAR OVER THE FORECAST AREA WITH 1000-2000J/KG MUCAPE SATURDAY AFTERNOON. DEEP LAYER MOISTURE IS LACKING COMPARED TO FRIDAY...BUT WE COULD SEE A FEW STRONGER STORMS. ON SUNDAY A STRONGER SHORTWAVE TROUGH AND ASSOCIATED JET MAX TRACK ACROSS THE FORECAST AREA. EVEN HIGHER BULK SHEAR WILL BE IN PLACE WITH MUCAPES AGAIN CLIMBING TO 1000-2000J/KG. EXPECT MORE WIDESPREAD SHOWERS AND THUNDERSTORMS TO TRAVERSE THE FORECAST AREA ON SUNDAY... WITH ANOTHER POSSIBILITY OF STRONG TO SEVERE STORMS. AN ACTIVE QUASI-ZONAL FLOW PATTERN CONTINUES THROUGH THE MIDDLE OF NEXT WEEK WITH NEARLY DAILY CHANCES OF SHOWERS AND THUNDERSTORMS. IN GENERAL...EXPECT DAYTIME HIGHS IN THE 70S AND MORNING LOWS IN THE 50S THROUGHOUT THE EXTENDED PERIOD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1258 PM CDT FRI JUN 19 2015 SEVERE THUNDERSTORMS INITIATING AFTER 20Z FRIDAY IN WESTERN NORTH DAKOTA AND AROUND 00Z SATURDAY IN CENTRAL NORTH DAKOTA...IS THE MAIN HAZARD FOR THE TERMINALS. STRONG WINDS...HAIL...AND HEAVY RAINFALL WILL BE THE PRIMARY THREATS. ENOUGH CONFIDENCE AT THIS TIME TO MENTION HEAVY THUNDERSTORMS WITH GUSTS TO 45KT AT KDIK/KBIS/KJMS LATE FRIDAY AFTERNOON INTO FRIDAY EVENING. KISN/KMOT REMAINS MORE UNCERTAIN AT THIS TIME FOR HEAVY THUNDERSTORMS AND HAVE DECIDED TO MENTION MODERATE AT KISN AND VCTS AT KMOT. SEVERE WEATHER WILL DIMINISH BY AROUND 06Z WITH KJMS THE LAST REMAINING AERODROME TO HAVE SHOWERS THROUGH 07Z. STRATUS/MVFR CIGS TO FOLLOW FOR KJMS SATURDAY MORNING...WITH SCT CLOUDS ELSEWHERE. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AYD SHORT TERM...AJ LONG TERM...TWH AVIATION...KS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1001 AM CDT FRI JUN 19 2015 .UPDATE... ISSUED AT 1001 AM CDT FRI JUN 19 2015 UPPER WAVE EVIDENT ON WATER VAPOR IMAGERY ACROSS CENTRAL NORTH DAKOTA INDUCING 850MB LOW LEVEL JET AND ENHANCED REGION OF 850MB WARM AIR ADVECTION...WITH ASSOCIATED RADAR RETURNS ACROSS NE ND AND NW MN. LATEST GUIDANCE INDICATES THIS FORCING WILL CONTINUE TO PROPAGATE TO THE EAST/NORTHEAST THROUGH THE DAY. INCREASED POPS FOR THIS AREA OF SHOWERS/ISOLD THUNDER ACTIVITY (FOLLOWING THE LATEST HRRR FOR TIMING). LIGHTNING ACTIVITY IS DECREASING...A SIGN THAT THIS FORCING IS OUTRUNNING INSTABILITY. THERE WILL BE A PERIOD OF DRY WEATHER BEHIND THIS SYSTEM...IN AN AREA OF SUBSIDENCE BEHIND THE SHORTWAVE...EVIDENT FROM SATELLITE IMAGERY. MAJOR QUESTIONS FOR SEVERE POTENTIAL THIS AFTERNOON/EVENING WILL BE DEVELOPMENT ALONG THE SFC BOUNDARY/WARM FRONT...AND THEN HOW FAR NORTH WILL THE MCS THAT DEVELOPMENTS ACROSS THE WESTERN DAKOTAS TRACK OVERNIGHT. LATEST SYNOPTIC MODELS AND CAM GUIDANCE TRENDING TOWARD MINIMAL DEVELOPMENT ALONG THE SFC BOUNDARY (DUE TO CAPPING ISSUES). THIS SFC BOUNDARY (WARM FRONT) WILL BE POSITIONED FROM SOUTHWEST NORTH DAKOTA INTO NORTHEAST NORTH DAKOTA. SYNOPTIC FORCING (FROM A STRONGER UPPER LEVEL WAVE) WILL BE DELAYED UNTIL CLOSER TO 03Z. THUS...LIKE THE IDEA OF POSSIBLY ISOLD STORMS CLOSER TO 00Z ALONG THE SFC BOUNDARY (AND POSSIBLY NO STORMS). ADJUSTED POPS AND DELAYED T+ MENTION UNTIL 00Z. AS THE SYNOPTIC FORCING OVERRIDES THE REGION...THINKING THAT THUNDERSTORM COVERAGE WILL INCREASE...INCREASING SEVERE POTENTIAL. THERE WILL ALSO BE THE MCS THAT INITIATES ACROSS THE WESTERN DAKOTAS...AND NOT SURE THE AFFECT THIS WILL HAVE ON ACTIVITY TO THE NORTH...OR WHERE THIS SYSTEM WILL TRACK (MAY AFFECT THE SOUTHERN FA). WILL CONTINUE TO MONITOR AND HOPEFULLY HAVE MORE DETAILS WITH THE 1PM UPDATE. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 330 AM CDT FRI JUN 19 2015 A BAND OF ELEVATED CONVECTION IS FORMING IN CENTRAL INTO NE ND EARLY THIS MORNING THE HRRR AND OTHER CAM MODELS HAVE THIS WELL IN HAND...AND EXPECT THIS CONVECTION TO CONTINUE TO MOVE/DEVELOP INTO THE DEVILS LAKE BASIN INTO THE NORTHERN VALLEY THROUGH THIS MORNING. MODELS ARE IN GOOD OVERALL AGREEMENT WITH LARGE SCALE FEATURES THROUGH THE PERIOD. THE EXACT DETAILS ARE ALWAYS CHALLENGING WITH CONVECTION...SO THIS WILL NEED TO BE IRONED OUT OVER THE NEXT SEVERAL DAYS. FOR TODAY AND TONIGHT...EXPECT A FAIRLY LARGE AREA OF ELEVATED CONVECTION THROUGH THE MORNING IN THE NORTH. THERE WILL BE INCREASING INSTABILITY THROUGH THE DAY ALONG AND WEST OF THE VALLEY. MODELS HINT AT SOME RE-DEVELOPMENT IN THE NORTH AND WESTERN FORECAST AREA THIS AFTERNOON...WITH SFC CAPE AROUND 2000 J/KG. IT APPEARS THAT THE MAIN CONVECTION WILL DEVELOP OVER THE WESTERN DAKOTAS LATER THIS AFTERNOON/EVENING...ALTHOUGH ANY AREAS THAT HEAT OUT TODAY WITH TDS INCREASING WILL HAVE TO BE WATCHED. DEEP LAYERED SHEAR THROUGH TONIGHT WILL BE STRONG...AROUND 50KT...SO ANY STORMS THAT FORM IN THE SLIGHT RISK AREA COULD BE SUPERCELLULAR INITIALLY. THERE SHOULD BE A LARGER SEVERE TYPE MCS MOVING FROM THE WESTERN DAKOTAS INTO THE SOUTHERN VALLEY...OR VERY CLOSE...LATER TONIGHT FROM 6Z-12Z. THIS WILL BE FED BY A STRONG LLJ AROUND 50KT AND PWATS APPROACHING 2 INCHES ON THE GFS AND NAM. WILL MENTION SEVERE IN THE SLIGHT RISK AREA 18Z-06Z...THEN IN THE SOUTHERN FA 6Z-12Z WITH SOME HEAVY RAIN POSSIBLE HERE ALSO. FOR SATURDAY...THERE WILL BE INSTABILITY BY AFTERNOON WITH ANOTHER SHORTWAVE MOVING THROUGH ACTIVE W/NW FLOW ALOFT. THE OVERALL LACK OF STRONGER FORCING/CONVERGENCE SHOULD LEAD TO ISOLATED COVERAGE FOR ANY AFTERNOON STORMS. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 330 AM CDT FRI JUN 19 2015 ON SUNDAY...A STRONG SHORTWAVE WILL APPROACH THE WESTERN FORECAST AREA BY AFTERNOON. THERE WILL BE ABOUT 1500 J/KG OF SFC CAPE AHEAD OF THE WAVE...AND STRONG DEEP SHEAR AROUND 55KT. THE MAIN THING WILL BE TIMING OF THE SHORTWAVE...AND SPC HAS INTRODUCED A MARGINAL RISK FOR SEVERE WEATHER IN THE RED RIVER VALLEY FOR FATHERS DAY. MONDAY TO THURSDAY...GOOD AGREEMENT IN THE EXTENDED WITH ZONAL TO NW FLOW ALOFT WITH PERIODIC SHORT WAVES AND FROPAS PUSHING ACROSS THE AREA. TIMING AND PLACEMENT OF THESE WAVES WITH WHERE AND WHEN TO INCREASE OR DECREASE POPS IS TOO UNCERTAIN OTHER THAN MAKE A CHC MENTION FOR MOST OF THE AREAS EVERYDAY IN THE EXTENDED. THE EXCEPTION IS MONDAY WITH A DRY DAY EXPECTED AS A WEAK SFC HIGH IS PROGGED TO MOVE ACROSS THE AREA. NEAR NORMAL TEMPERATURES NEXT WEEK WITH UPP70S TO NEAR 80 FOR HIGHS AND LOWS IN THE UPPER 50S TO LOW 60S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 620 AM CDT FRI JUN 19 2015 THE MAIN CHALLENGE WILL BE SHOWERS AND STORMS THROUGH TONIGHT. AFTER THIS MORNINGS BAND OF ELEVATED SHOWERS AND STORMS...STRONGER STORMS MAY DEVELOP THIS AFTERNOON AND OVERNIGHT. EXPECT OVERALL VFR CONDITIONS ALTHOUGH MVFR CONDITIONS ARE POSSIBLE NEAR STRONGER SHOWERS AND STORMS. SOUTHERLY WINDS WILL SHIFT MORE NORTHERLY OVERNIGHT BEHIND A SFC BOUNDARY. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...TG SHORT TERM...DK LONG TERM...JK/DK AVIATION...DK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
959 AM CDT FRI JUN 19 2015 .UPDATE... ISSUED AT 946 AM CDT FRI JUN 19 2015 THE 11-13 UTC HRRR ITERATIONS...00 UTC SPC WRF AND 12 UTC NAM ARE IN GOOD AGREEMENT REGARDING THE POTENTIAL EVOLUTION OF THE SEVERE CONVECTIVE EVENT LATE THIS AFTERNOON AND THROUGH THE EVENING. THE CONSENSUS IS FOR POTENTIAL SUPERCELLS TO INITIATE OR CROSS INTO FAR WESTERN NORTH DAKOTA AROUND 22 UTC WITH THE ARRIVAL OF MULTIPLE IMPULSES EMBEDDED IN THE FAST WESTERLIES ALOFT. 2000-2500 J/KG OF ML CAPE AND STRONG DEEP LAYER SHEAR OF 40-50 KTS GENERALLY SOUTH OF ND HIGHWAY 200 SUPPORTS SUPERCELLS WITH LARGE HAIL AND DAMAGING WINDS THE PRIMARY THREATS. WHILE LOW LEVEL SHEAR IS WEAK AND LCLS A BIT HIGH...CERTAINLY CANNOT RULE OUT A TORNADO OR TWO GIVEN DISCRETE SUPERCELLS TO BEGIN THE EVENT. CONGEALING OF STORMS INTO A POSSIBLE MCS IS STILL FAVORED LATE THIS EVENING ACROSS NORTH CENTRAL SOUTH DAKOTA INTO SOUTH CENTRAL NORTH DAKOTA. ACROSS NORTHERN NORTH DAKOTA...LOW LEVEL STRATUS THIS MORNING MAY HELP TO LIMIT THE OVERALL SEVERE THREAT FOR TODAY. UPDATE ISSUED AT 631 AM CDT FRI JUN 19 2015 ONGOING ELEVATED CONVECTION OVER NORTH CENTRAL NORTH DAKOTA WILL CONTINUE TO TRACK EASTWARD THIS MORNING. RAISED POPS NORTH CENTRAL THIS MORNING...AND UPDATED POPS BASED ON LATEST RADAR TRENDS. OTHERWISE NO SIGNIFICANT CHANGES TO THE GOING FORECAST. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 253 AM CDT FRI JUN 19 2015 THE MAIN FOCUS FOR THE SHORT TERM IS SEVERE STORMS THIS AFTERNOON AND EVENING. EARLY THIS MORNING A COMPLEX OF SEVERE STORMS WAS MOVING ACROSS NORTHWESTERN SOUTH DAKOTA. THIS SHOULD STAY SOUTH OF NORTH DAKOTA. LOCATIONS ALONG THE ND/SD BORDER COULD SEE SOME LIGHT RAIN AND LIGHTNING...BUT THE MAIN STORM WILL BE FURTHER SOUTH. OTHERWISE...SCATTERED THUNDERSTORMS WERE RAPIDLY FORMING ACROSS NORTHERN NORTH DAKOTA ON THE NOSE OF A POTENT LOW LEVEL JET. THIS ACTIVITY WAS PICKED UP WELL BY THE HRRR AND IS EXPECTED TO CONTINUE ACROSS THE NORTH THROUGH THE EARLY MORNING HOURS. THIS EARLY MORNING CONVECTION IS NOT EXPECTED TO DIMINISH SEVERE CHANCES LATER THIS AFTERNOON AS SKIES SHOULD CLEAR AND LEAD TO PLENTY OF AFTERNOON HEATING. GENERAL MODEL CONSENSUS INDICATES THUNDERSTORM DEVELOPMENT BY LATE THIS AFTERNOON ACROSS WESTERN NORTH DAKOTA. INITIAL STORMS COULD RAPIDLY INTENSIFY AND BECOME SUPERCELLULAR WITH 2K+ CAPE...50 KNOTS OF 0-6 KM SHEAR...STEEP LAPSE RATES AND AMPLE FORCING PROVIDED BY A SURFACE LOW AND APPROACHING UPPER-LEVEL SHORTWAVE TROUGH. INITIAL THREATS WITH THESE STORMS WOULD BE VERY LARGE HAIL...A FEW TORNADOES...VERY HEAVY RAIN AND DAMAGING WIND. CONVECTIVE MODELS (WRFS) THEN INDICATE MERGING OF CELLS INTO A LINE SEGMENT ACROSS CENTRAL AND SOUTHERN NORTH DAKOTA. THERE IS SOME UNCERTAINTY AS TO WHERE EXACTLY THIS POTENTIAL LINE WOULD DEVELOP/MOVE. THE NSSL WRF SHOWS THE BULK OF THE LINE QUICKLY DIVING INTO SOUTH DAKOTA...FOLLOWING A SIMILAR TRACK TO THE THIS EARLY MORNING`S COMPLEX. DAMAGING WINDS WOULD BE THE MAIN THREAT WITH AN EVENING/OVERNIGHT SQUALL LINE. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 253 AM CDT FRI JUN 19 2015 DETERMINISTIC AND ENSEMBLE GUIDANCE CONTINUES TO SUGGEST AN ACTIVE PATTERN TO CONTINUE THROUGH THE EXTENDED PERIOD. ON SATURDAY...A NEARLY ZONAL FLOW OVER THE FORECAST AREA WILL CONTINUE TO PROVIDE SUPPORT FOR ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS. 19 JUN 00 UTC ECMWF/GFS MODEL GUIDANCE DEPICTS 20 TO 40 KNOTS OF BULK SHEAR OVER THE FORECAST AREA WITH 1000-2000J/KG MUCAPE SATURDAY AFTERNOON. DEEP LAYER MOISTURE IS LACKING COMPARED TO FRIDAY...BUT WE COULD SEE A FEW STRONGER STORMS. ON SUNDAY A STRONGER SHORTWAVE TROUGH AND ASSOCIATED JET MAX TRACK ACROSS THE FORECAST AREA. EVEN HIGHER BULK SHEAR WILL BE IN PLACE WITH MUCAPES AGAIN CLIMBING TO 1000-2000J/KG. EXPECT MORE WIDESPREAD SHOWERS AND THUNDERSTORMS TO TRAVERSE THE FORECAST AREA ON SUNDAY... WITH ANOTHER POSSIBILITY OF STRONG TO SEVERE STORMS. AN ACTIVE QUASI-ZONAL FLOW PATTERN CONTINUES THROUGH THE MIDDLE OF NEXT WEEK WITH NEARLY DAILY CHANCES OF SHOWERS AND THUNDERSTORMS. IN GENERAL...EXPECT DAYTIME HIGHS IN THE 70S AND MORNING LOWS IN THE 50S THROUGHOUT THE EXTENDED PERIOD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 946 AM CDT FRI JUN 19 2015 MVFR/IFR STRATUS ACROSS NORTHWEST AND NORTH CENTRAL NORTH DAKOTA THIS MORNING WILL SLOWLY LIFT WITH DAYTIME HEATING. THUNDERSTORM CHANCES INCREASE LATE THIS AFTERNOON AND THROUGH THE EVENING ACROSS WESTERN AND CENTRAL NORTH DAKOTA. SOME STORMS MAY BE SEVERE WITH LARGE HAIL...DAMAGING WINDS AND LIFR CONDITIONS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AYD SHORT TERM...AJ LONG TERM...TWH AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
637 AM CDT FRI JUN 19 2015 .UPDATE... ISSUED AT 631 AM CDT FRI JUN 19 2015 ONGOING ELEVATED CONVECTION OVER NORTH CENTRAL NORTH DAKOTA WILL CONTINUE TO TRACK EASTWARD THIS MORNING. RAISED POPS NORTH CENTRAL THIS MORNING...AND UPDATED POPS BASED ON LATEST RADAR TRENDS. OTHERWISE NO SIGNIFICANT CHANGES TO THE GOING FORECAST. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 253 AM CDT FRI JUN 19 2015 THE MAIN FOCUS FOR THE SHORT TERM IS SEVERE STORMS THIS AFTERNOON AND EVENING. EARLY THIS MORNING A COMPLEX OF SEVERE STORMS WAS MOVING ACROSS NORTHWESTERN SOUTH DAKOTA. THIS SHOULD STAY SOUTH OF NORTH DAKOTA. LOCATIONS ALONG THE ND/SD BORDER COULD SEE SOME LIGHT RAIN AND LIGHTNING...BUT THE MAIN STORM WILL BE FURTHER SOUTH. OTHERWISE...SCATTERED THUNDERSTORMS WERE RAPIDLY FORMING ACROSS NORTHERN NORTH DAKOTA ON THE NOSE OF A POTENT LOW LEVEL JET. THIS ACTIVITY WAS PICKED UP WELL BY THE HRRR AND IS EXPECTED TO CONTINUE ACROSS THE NORTH THROUGH THE EARLY MORNING HOURS. THIS EARLY MORNING CONVECTION IS NOT EXPECTED TO DIMINISH SEVERE CHANCES LATER THIS AFTERNOON AS SKIES SHOULD CLEAR AND LEAD TO PLENTY OF AFTERNOON HEATING. GENERAL MODEL CONSENSUS INDICATES THUNDERSTORM DEVELOPMENT BY LATE THIS AFTERNOON ACROSS WESTERN NORTH DAKOTA. INITIAL STORMS COULD RAPIDLY INTENSIFY AND BECOME SUPERCELLULAR WITH 2K+ CAPE...50 KNOTS OF 0-6 KM SHEAR...STEEP LAPSE RATES AND AMPLE FORCING PROVIDED BY A SURFACE LOW AND APPROACHING UPPER-LEVEL SHORTWAVE TROUGH. INITIAL THREATS WITH THESE STORMS WOULD BE VERY LARGE HAIL...A FEW TORNADOES...VERY HEAVY RAIN AND DAMAGING WIND. CONVECTIVE MODELS (WRFS) THEN INDICATE MERGING OF CELLS INTO A LINE SEGMENT ACROSS CENTRAL AND SOUTHERN NORTH DAKOTA. THERE IS SOME UNCERTAINTY AS TO WHERE EXACTLY THIS POTENTIAL LINE WOULD DEVELOP/MOVE. THE NSSL WRF SHOWS THE BULK OF THE LINE QUICKLY DIVING INTO SOUTH DAKOTA...FOLLOWING A SIMILAR TRACK TO THE THIS EARLY MORNING`S COMPLEX. DAMAGING WINDS WOULD BE THE MAIN THREAT WITH AN EVENING/OVERNIGHT SQUALL LINE. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 253 AM CDT FRI JUN 19 2015 DETERMINISTIC AND ENSEMBLE GUIDANCE CONTINUES TO SUGGEST AN ACTIVE PATTERN TO CONTINUE THROUGH THE EXTENDED PERIOD. ON SATURDAY...A NEARLY ZONAL FLOW OVER THE FORECAST AREA WILL CONTINUE TO PROVIDE SUPPORT FOR ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS. 19 JUN 00 UTC ECMWF/GFS MODEL GUIDANCE DEPICTS 20 TO 40 KNOTS OF BULK SHEAR OVER THE FORECAST AREA WITH 1000-2000J/KG MUCAPE SATURDAY AFTERNOON. DEEP LAYER MOISTURE IS LACKING COMPARED TO FRIDAY...BUT WE COULD SEE A FEW STRONGER STORMS. ON SUNDAY A STRONGER SHORTWAVE TROUGH AND ASSOCIATED JET MAX TRACK ACROSS THE FORECAST AREA. EVEN HIGHER BULK SHEAR WILL BE IN PLACE WITH MUCAPES AGAIN CLIMBING TO 1000-2000J/KG. EXPECT MORE WIDESPREAD SHOWERS AND THUNDERSTORMS TO TRAVERSE THE FORECAST AREA ON SUNDAY... WITH ANOTHER POSSIBILITY OF STRONG TO SEVERE STORMS. AN ACTIVE QUASI-ZONAL FLOW PATTERN CONTINUES THROUGH THE MIDDLE OF NEXT WEEK WITH NEARLY DAILY CHANCES OF SHOWERS AND THUNDERSTORMS. IN GENERAL...EXPECT DAYTIME HIGHS IN THE 70S AND MORNING LOWS IN THE 50S THROUGHOUT THE EXTENDED PERIOD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 631 AM CDT FRI JUN 19 2015 SHOWERS AND THUNDERSTORMS WITH MVFR CEILINGS AND VISIBILITIES TO BEGIN THE 12Z TAF PERIOD AT MINOT. LINGERING MVFR CEILINGS AT KISN THROUGH AROUND 15 UTC. MAINLY VFR CONDIITONS EXPECTED THIS MORNING FROM KDIK-KBIS-KJMS. THUNDERSTORM CHANCES INCREASE BY FRIDAY AFTERNOON...WITH SOME STORMS BECOMING SEVERE. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...TWH SHORT TERM...AJ LONG TERM...TWH AVIATION...TWH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
619 AM CDT FRI JUN 19 2015 .UPDATE... ISSUED AT 620 AM CDT FRI JUN 19 2015 NO MAJOR CHANGES THIS MORNING. THE BAND OF ELEVATED SHOWERS WITH A FEW LIGHTNING STRIKES WILL AFFECT MAINLY NORTHERN AREAS THIS MORNING. THE NAM/GFS STILL INDICATE THE THREAT FOR SFC BASED CONVECTION AFTER 21Z NEAR THE DEVILS LAKE BASIN...THEN MOVING EAST THIS EVENING. THE MORE ORGANIZED SEVERE MCS SHOULD AFFECT THE FAR SOUTHERN VALLEY LATER TONIGHT...AND WE WILL MONITOR SEVERE THREAT TODAY CLOSELY. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 330 AM CDT FRI JUN 19 2015 A BAND OF ELEVATED CONVECTION IS FORMING IN CENTRAL INTO NE ND EARLY THIS MORNING THE HRRR AND OTHER CAM MODELS HAVE THIS WELL IN HAND...AND EXPECT THIS CONVECTION TO CONTINUE TO MOVE/DEVELOP INTO THE DEVILS LAKE BASIN INTO THE NORTHERN VALLEY THROUGH THIS MORNING. MODELS ARE IN GOOD OVERALL AGREEMENT WITH LARGE SCALE FEATURES THROUGH THE PERIOD. THE EXACT DETAILS ARE ALWAYS CHALLENGING WITH CONVECTION...SO THIS WILL NEED TO BE IRONED OUT OVER THE NEXT SEVERAL DAYS. FOR TODAY AND TONIGHT...EXPECT A FAIRLY LARGE AREA OF ELEVATED CONVECTION THROUGH THE MORNING IN THE NORTH. THERE WILL BE INCREASING INSTABILITY THROUGH THE DAY ALONG AND WEST OF THE VALLEY. MODELS HINT AT SOME RE-DEVELOPMENT IN THE NORTH AND WESTERN FORECAST AREA THIS AFTERNOON...WITH SFC CAPE AROUND 2000 J/KG. IT APPEARS THAT THE MAIN CONVECTION WILL DEVELOP OVER THE WESTERN DAKOTAS LATER THIS AFTERNOON/EVENING...ALTHOUGH ANY AREAS THAT HEAT OUT TODAY WITH TDS INCREASING WILL HAVE TO BE WATCHED. DEEP LAYERED SHEAR THROUGH TONIGHT WILL BE STRONG...AROUND 50KT...SO ANY STORMS THAT FORM IN THE SLIGHT RISK AREA COULD BE SUPERCELLULAR INITIALLY. THERE SHOULD BE A LARGER SEVERE TYPE MCS MOVING FROM THE WESTERN DAKOTAS INTO THE SOUTHERN VALLEY...OR VERY CLOSE...LATER TONIGHT FROM 6Z-12Z. THIS WILL BE FED BY A STRONG LLJ AROUND 50KT AND PWATS APPROACHING 2 INCHES ON THE GFS AND NAM. WILL MENTION SEVERE IN THE SLIGHT RISK AREA 18Z-06Z...THEN IN THE SOUTHERN FA 6Z-12Z WITH SOME HEAVY RAIN POSSIBLE HERE ALSO. FOR SATURDAY...THERE WILL BE INSTABILITY BY AFTERNOON WITH ANOTHER SHORTWAVE MOVING THROUGH ACTIVE W/NW FLOW ALOFT. THE OVERALL LACK OF STRONGER FORCING/CONVERGENCE SHOULD LEAD TO ISOLATED COVERAGE FOR ANY AFTERNOON STORMS. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 330 AM CDT FRI JUN 19 2015 ON SUNDAY...A STRONG SHORTWAVE WILL APPROACH THE WESTERN FORECAST AREA BY AFTERNOON. THERE WILL BE ABOUT 1500 J/KG OF SFC CAPE AHEAD OF THE WAVE...AND STRONG DEEP SHEAR AROUND 55KT. THE MAIN THING WILL BE TIMING OF THE SHORTWAVE...AND SPC HAS INTRODUCED A MARGINAL RISK FOR SEVERE WEATHER IN THE RED RIVER VALLEY FOR FATHERS DAY. MONDAY TO THURSDAY...GOOD AGREEMENT IN THE EXTENDED WITH ZONAL TO NW FLOW ALOFT WITH PERIODIC SHORT WAVES AND FROPAS PUSHING ACROSS THE AREA. TIMING AND PLACEMENT OF THESE WAVES WITH WHERE AND WHEN TO INCREASE OR DECREASE POPS IS TOO UNCERTAIN OTHER THAN MAKE A CHC MENTION FOR MOST OF THE AREAS EVERYDAY IN THE EXTENDED. THE EXCEPTION IS MONDAY WITH A DRY DAY EXPECTED AS A WEAK SFC HIGH IS PROGGED TO MOVE ACROSS THE AREA. NEAR NORMAL TEMPERATURES NEXT WEEK WITH UPP70S TO NEAR 80 FOR HIGHS AND LOWS IN THE UPPER 50S TO LOW 60S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 620 AM CDT FRI JUN 19 2015 THE MAIN CHALLENGE WILL BE SHOWERS AND STORMS THROUGH TONIGHT. AFTER THIS MORNINGS BAND OF ELEVATED SHOWERS AND STORMS...STRONGER STORMS MAY DEVELOP THIS AFTERNOON AND OVERNIGHT. EXPECT OVERALL VFR CONDITIONS ALTHOUGH MVFR CONDITIONS ARE POSSIBLE NEAR STRONGER SHOWERS AND STORMS. SOUTHERLY WINDS WILL SHIFT MORE NORTHERLY OVERNIGHT BEHIND A SFC BOUNDARY. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...DK SHORT TERM...DK LONG TERM...JK/DK AVIATION...DK
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
332 AM CDT FRI JUN 19 2015 .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 330 AM CDT FRI JUN 19 2015 A BAND OF ELEVATED CONVECTION IS FORMING IN CENTRAL INTO NE ND EARLY THIS MORNING THE HRRR AND OTHER CAM MODELS HAVE THIS WELL IN HAND...AND EXPECT THIS CONVECTION TO CONTINUE TO MOVE/DEVELOP INTO THE DEVILS LAKE BASIN INTO THE NORTHERN VALLEY THROUGH THIS MORNING. MODELS ARE IN GOOD OVERALL AGREEMENT WITH LARGE SCALE FEATURES THROUGH THE PERIOD. THE EXACT DETAILS ARE ALWAYS CHALLENGING WITH CONVECTION...SO THIS WILL NEED TO BE IRONED OUT OVER THE NEXT SEVERAL DAYS. FOR TODAY AND TONIGHT...EXPECT A FAIRLY LARGE AREA OF ELEVATED CONVECTION THROUGH THE MORNING IN THE NORTH. THERE WILL BE INCREASING INSTABILITY THROUGH THE DAY ALONG AND WEST OF THE VALLEY. MODELS HINT AT SOME RE-DEVELOPMENT IN THE NORTH AND WESTERN FORECAST AREA THIS AFTERNOON...WITH SFC CAPE AROUND 2000 J/KG. IT APPEARS THAT THE MAIN CONVECTION WILL DEVELOP OVER THE WESTERN DAKOTAS LATER THIS AFTERNOON/EVENING...ALTHOUGH ANY AREAS THAT HEAT OUT TODAY WITH TDS INCREASING WILL HAVE TO BE WATCHED. DEEP LAYERED SHEAR THROUGH TONIGHT WILL BE STRONG...AROUND 50KT...SO ANY STORMS THAT FORM IN THE SLIGHT RISK AREA COULD BE SUPERCELLULAR INITIALLY. THERE SHOULD BE A LARGER SEVERE TYPE MCS MOVING FROM THE WESTERN DAKOTAS INTO THE SOUTHERN VALLEY...OR VERY CLOSE...LATER TONIGHT FROM 6Z-12Z. THIS WILL BE FED BY A STRONG LLJ AROUND 50KT AND PWATS APPROACHING 2 INCHES ON THE GFS AND NAM. WILL MENTION SEVERE IN THE SLIGHT RISK AREA 18Z-06Z...THEN IN THE SOUTHERN FA 6Z-12Z WITH SOME HEAVY RAIN POSSIBLE HERE ALSO. FOR SATURDAY...THERE WILL BE INSTABILITY BY AFTERNOON WITH ANOTHER SHORTWAVE MOVING THROUGH ACTIVE W/NW FLOW ALOFT. THE OVERALL LACK OF STRONGER FORCING/CONVERGENCE SHOULD LEAD TO ISOLATED COVERAGE FOR ANY AFTERNOON STORMS. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 330 AM CDT FRI JUN 19 2015 ON SUNDAY...A STRONG SHORTWAVE WILL APPROACH THE WESTERN FORECAST AREA BY AFTERNOON. THERE WILL BE ABOUT 1500 J/KG OF SFC CAPE AHEAD OF THE WAVE...AND STRONG DEEP SHEAR AROUND 55KT. THE MAIN THING WILL BE TIMING OF THE SHORTWAVE...AND SPC HAS INTRODUCED A MARGINAL RISK FOR SEVERE WEATHER IN THE RED RIVER VALLEY FOR FATHERS DAY. MONDAY TO THURSDAY...GOOD AGREEMENT IN THE EXTENDED WITH ZONAL TO NW FLOW ALOFT WITH PERIODIC SHORT WAVES AND FROPAS PUSHING ACROSS THE AREA. TIMING AND PLACEMENT OF THESE WAVES WITH WHERE AND WHEN TO INCREASE OR DECREASE POPS IS TOO UNCERTAIN OTHER THAN MAKE A CHC MENTION FOR MOST OF THE AREAS EVERYDAY IN THE EXTENDED. THE EXCEPTION IS MONDAY WITH A DRY DAY EXPECTED AS A WEAK SFC HIGH IS PROGGED TO MOVE ACROSS THE AREA. NEAR NORMAL TEMPERATURES NEXT WEEK WITH UPP70S TO NEAR 80 FOR HIGHS AND LOWS IN THE UPPER 50S TO LOW 60S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1138 PM CDT THU JUN 18 2015 VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD AS HIGH PRESSURE REMAINS IN CONTROL. LIGHT AND VARIABLE WINDS WILL TURN MORE SOUTHERLY LATER IN THE PERIOD AS LOW PRESSURE BEGINS TO MOVE INTO THE DAKOTAS. AN UPPER LEVEL WAVE IS STILL PROGGED TO CROSS THE AREA GENERATING SOME SHOWER ACTIVITY AROUND 12Z...AND MADE MENTION IN THE TAFS. CONFIDENCE IN THUNDER INCREASING A BIT FOR LATE IN THE TAF PERIOD AS THE LOW PRESSURE SYSTEM CROSSES THE FA...WITH BEST CHANCES AFTER THE 00Z TIME FRAME. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ SHORT TERM...DK LONG TERM...JK/DK AVIATION...HOPKINS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
317 AM CDT FRI JUN 19 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 253 AM CDT FRI JUN 19 2015 THE MAIN FOCUS FOR THE SHORT TERM IS SEVERE STORMS THIS AFTERNOON AND EVENING. EARLY THIS MORNING A COMPLEX OF SEVERE STORMS WAS MOVING ACROSS NORTHWESTERN SOUTH DAKOTA. THIS SHOULD STAY SOUTH OF NORTH DAKOTA. LOCATIONS ALONG THE ND/SD BORDER COULD SEE SOME LIGHT RAIN AND LIGHTNING...BUT THE MAIN STORM WILL BE FURTHER SOUTH. OTHERWISE...SCATTERED THUNDERSTORMS WERE RAPIDLY FORMING ACROSS NORTHERN NORTH DAKOTA ON THE NOSE OF A POTENT LOW LEVEL JET. THIS ACTIVITY WAS PICKED UP WELL BY THE HRRR AND IS EXPECTED TO CONTINUE ACROSS THE NORTH THROUGH THE EARLY MORNING HOURS. THIS EARLY MORNING CONVECTION IS NOT EXPECTED TO DIMINISH SEVERE CHANCES LATER THIS AFTERNOON AS SKIES SHOULD CLEAR AND LEAD TO PLENTY OF AFTERNOON HEATING. GENERAL MODEL CONSENSUS INDICATES THUNDERSTORM DEVELOPMENT BY LATE THIS AFTERNOON ACROSS WESTERN NORTH DAKOTA. INITIAL STORMS COULD RAPIDLY INTENSIFY AND BECOME SUPERCELLULAR WITH 2K+ CAPE...50 KNOTS OF 0-6 KM SHEAR...STEEP LAPSE RATES AND AMPLE FORCING PROVIDED BY A SURFACE LOW AND APPROACHING UPPER-LEVEL SHORTWAVE TROUGH. INITIAL THREATS WITH THESE STORMS WOULD BE VERY LARGE HAIL...A FEW TORNADOES...VERY HEAVY RAIN AND DAMAGING WIND. CONVECTIVE MODELS (WRFS) THEN INDICATE MERGING OF CELLS INTO A LINE SEGMENT ACROSS CENTRAL AND SOUTHERN NORTH DAKOTA. THERE IS SOME UNCERTAINTY AS TO WHERE EXACTLY THIS POTENTIAL LINE WOULD DEVELOP/MOVE. THE NSSL WRF SHOWS THE BULK OF THE LINE QUICKLY DIVING INTO SOUTH DAKOTA...FOLLOWING A SIMILAR TRACK TO THE THIS EARLY MORNING`S COMPLEX. DAMAGING WINDS WOULD BE THE MAIN THREAT WITH AN EVENING/OVERNIGHT SQUALL LINE. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 253 AM CDT FRI JUN 19 2015 DETERMINISTIC AND ENSEMBLE GUIDANCE CONTINUES TO SUGGEST AN ACTIVE PATTERN TO CONTINUE THROUGH THE EXTENDED PERIOD. ON SATURDAY...A NEARLY ZONAL FLOW OVER THE FORECAST AREA WILL CONTINUE TO PROVIDE SUPPORT FOR ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS. 19 JUN 00 UTC ECMWF/GFS MODEL GUIDANCE DEPICTS 20 TO 40 KNOTS OF BULK SHEAR OVER THE FORECAST AREA WITH 1000-2000J/KG MUCAPE SATURDAY AFTERNOON. DEEP LAYER MOISTURE IS LACKING COMPARED TO FRIDAY...BUT WE COULD SEE A FEW STRONGER STORMS. ON SUNDAY A STRONGER SHORTWAVE TROUGH AND ASSOCIATED JET MAX TRACK ACROSS THE FORECAST AREA. EVEN HIGHER BULK SHEAR WILL BE IN PLACE WITH MUCAPES AGAIN CLIMBING TO 1000-2000J/KG. EXPECT MORE WIDESPREAD SHOWERS AND THUNDERSTORMS TO TRAVERSE THE FORECAST AREA ON SUNDAY... WITH ANOTHER POSSIBILITY OF STRONG TO SEVERE STORMS. AN ACTIVE QUASI-ZONAL FLOW PATTERN CONTINUES THROUGH THE MIDDLE OF NEXT WEEK WITH NEARLY DAILY CHANCES OF SHOWERS AND THUNDERSTORMS. IN GENERAL...EXPECT DAYTIME HIGHS IN THE 70S AND MORNING LOWS IN THE 50S THROUGHOUT THE EXTENDED PERIOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1223 AM CDT FRI JUN 19 2015 MAINLY VFR CONDITIONS THROUGH THE TAF PERIOD. SOME SHOWERS WITH A FEW THUNDERSTORMS MAY DEVELOP EARLY THIS MORNING NEAR KISN/KMOT. A COMPLEX OF THUNDERSTORMS ACROSS SOUTHEASTERN MONTANA SHOULD STAY WELL TO THE SOUTH OF KDIK. THUNDERSTORM CHANCES INCREASE BY FRIDAY AFTERNOON...WITH SOME STORMS BECOMING SEVERE. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...AJ LONG TERM...TWH AVIATION...AJ
AREA FORECAST DISCUSSION
NWS NORMAN OK
1045 PM CDT SAT JUN 20 2015 .AVIATION... COULD SEE SOME LOW CLOUDS DEVELOP NORTHWARD INTO NORTH TEXAS INTO SOUTHWEST AND CENTRAL OKLAHOMA LATE TONIGHT. HAVE GONE AHEAD AND ADDED A TEMPO GROUP FOR A PERIOD OF MVFR CEILINGS AT SPS/LAW/OKC/OUN. SHOULD SEE BREAK UP/RISE BY MID-MORNING. OTHERWISE S/SW WINDS WILL INCREASE AGAIN DURING THE DAY SUNDAY WITH SOME GUSTS APPROACHING 30KTS BY AFTN. 30 && .PREV DISCUSSION... /ISSUED 904 PM CDT SAT JUN 20 2015/ .UPDATE... DELAYED RAIN CHANCES IN SOUTHERN OKLAHOMA UNTIL AFTER 4 AM TONIGHT. MADE VERY SMALL ADJUSTMENTS TO CLOUD COVER TONIGHT AS WELL. && .DISCUSSION... WARM AND MUGGY WEATHER WILL CONTINUE TONIGHT. ANY RAIN CHANCES SHOULD BE CONFINED TO LOCATIONS SOUTH OF A WICHITA FALLS TO ADA LINE AND AFTER 4 AM TONIGHT. BASED ON LATEST RADARS INDICATING NO ECHOES IN THE LOCATIONS MENTIONED ABOVE AND LATEST HRRR RUNS...DELAYED RAIN CHANCES UNTIL AFTER 4 AM TONIGHT IN THOSE LOCATIONS. NO STRONG OR SEVERE STORMS ARE EXPECTED...THOUGH LOCALLY HEAVY RAINFALL COULD OCCUR AS THE AIR IS QUITE MOIST WITH SURFACE DEWPOINTS IN THE LOWER 70S. LATEST HRRR RUNS HAVE ALSO HINTED THAT WEAKENING CONVECTION FROM A DECAYING MCS COULD MOVE INTO FAR NORTHERN OKLAHOMA AFTER 6 AM SUNDAY MORNING. THIS SEEMS TO BE TOO FAR SOUTH AND UNLIKELY AS MID LEVEL TEMPERATURES AND CAPPING SEEM TO BE VERY STRONG OVER THE AREA...SO DISCOUNTED THIS SOLUTION. CLOUD COVER WAS ADJUSTED SLIGHTLY UPWARDS SOUTH OF I-40 TONIGHT. OVERNIGHT LOWS ARE IN GOOD SHAPE AND WERE NOT ALTERED. AVIATION DISCUSSION FOR THE 00Z TAFS IS BELOW. MBS && .AVIATION... VFR CONDITIONS ARE EXPECTED TO CONTINUE. THERE IS A CHANCE FOR MVFR CONDITIONS 09-16Z SOUTH OF KCSM- KSWO...BUT WAS NOT MENTIONED DUE TO LOW CONFIDENCE. 30/17 && .PREV DISCUSSION... /ISSUED 252 PM CDT SAT JUN 20 2015/ DISCUSSION... A MID-LEVEL LOW/SHEAR AXIS OVER TEXAS...WILL AID IN THE DEVELOP OF WIDELY SCATTERED SHOWERS AND STORMS THROUGH SUNDAY. SOUTH CENTRAL AND SOUTHEAST OKLAHOMA WILL HAVE THE BEST OPPORTUNITY FOR RAIN...AS THIS FEATURE MOVES NORTHEAST. MEANWHILE...HEIGHT RISES WILL OCCUR AS AN ELONGATED RIDGE BUILDS OVER THE SOUTHERN PLAINS. BREEZY SOUTHWEST WINDS WILL BACK THIS AFTERNOON/EARLY EVENING. BY EARLY SUNDAY...SOME LOW TO MID CLOUDS SHOULD COVER AT LEAST THE SOUTHERN THIRD OF THE FA. DRY AND HOT WEATHER IS EXPECTED MONDAY THROUGH WEDNESDAY. BY THURSDAY/FRIDAY...A WEST TO NORTHWEST FLOW ALOFT IS EXPECTED ACROSS THE CENTRAL AND SOUTHERN PLAINS. THIS COMBINED WITH A SYSTEM MOVING ACROSS THE NORTHERN PLAINS/UPPER MIDWEST...SHOULD PUSH A COLD FRONT CLOSER TO NORTHERN OKLAHOMA. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 73 92 72 92 / 0 10 10 0 HOBART OK 71 94 72 95 / 0 0 0 0 WICHITA FALLS TX 73 93 73 95 / 10 10 10 10 GAGE OK 71 95 71 95 / 0 0 0 0 PONCA CITY OK 74 95 75 95 / 0 0 0 0 DURANT OK 74 91 72 93 / 30 40 30 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 17/30
AREA FORECAST DISCUSSION
NWS TULSA OK
941 PM CDT SAT JUN 20 2015 .DISCUSSION... FORECAST ON-TRACK. HRRR TAKES MINOR NORTHEAST TEXAS CONVECTION NEAR/INTO EXTREME SOUTHEASTERN ZONES LATE TONIGHT SUNDAY MORNING. LOW CHANCE POPS AT THIS TIME. GW && .PRELIMINARY POINT TEMPS/POPS... TUL 77 92 76 95 / 0 0 10 10 FSM 73 92 74 95 / 0 20 10 10 MLC 74 89 75 92 / 0 10 10 10 BVO 73 92 73 95 / 0 0 10 10 FYV 69 87 71 90 / 0 20 10 10 BYV 74 88 72 90 / 0 10 10 10 MKO 73 90 73 93 / 0 10 10 10 MIO 73 91 74 93 / 0 10 10 10 F10 73 89 74 92 / 0 0 10 10 HHW 75 89 73 91 / 20 20 10 10 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ SHORT TERM...21 LONG TERM....21
AREA FORECAST DISCUSSION
NWS NORMAN OK
904 PM CDT SAT JUN 20 2015 .UPDATE... DELAYED RAIN CHANCES IN SOUTHERN OKLAHOMA UNTIL AFTER 4 AM TONIGHT. MADE VERY SMALL ADJUSTMENTS TO CLOUD COVER TONIGHT AS WELL. && .DISCUSSION... WARM AND MUGGY WEATHER WILL CONTINUE TONIGHT. ANY RAIN CHANCES SHOULD BE CONFINED TO LOCATIONS SOUTH OF A WICHITA FALLS TO ADA LINE AND AFTER 4 AM TONIGHT. BASED ON LATEST RADARS INDICATING NO ECHOES IN THE LOCATIONS MENTIONED ABOVE AND LATEST HRRR RUNS...DELAYED RAIN CHANCES UNTIL AFTER 4 AM TONIGHT IN THOSE LOCATIONS. NO STRONG OR SEVERE STORMS ARE EXPECTED...THOUGH LOCALLY HEAVY RAINFALL COULD OCCUR AS THE AIR IS QUITE MOIST WITH SURFACE DEWPOINTS IN THE LOWER 70S. LATEST HRRR RUNS HAVE ALSO HINTED THAT WEAKENING CONVECTION FROM A DECAYING MCS COULD MOVE INTO FAR NORTHERN OKLAHOMA AFTER 6 AM SUNDAY MORNING. THIS SEEMS TO BE TOO FAR SOUTH AND UNLIKELY AS MID LEVEL TEMPERATURES AND CAPPING SEEM TO BE VERY STRONG OVER THE AREA...SO DISCOUNTED THIS SOLUTION. CLOUD COVER WAS ADJUSTED SLIGHTLY UPWARDS SOUTH OF I-40 TONIGHT. OVERNIGHT LOWS ARE IN GOOD SHAPE AND WERE NOT ALTERED. AVIATION DISCUSSION FOR THE 00Z TAFS IS BELOW. MBS && .AVIATION... VFR CONDITIONS ARE EXPECTED TO CONTINUE. THERE IS A CHANCE FOR MVFR CONDITIONS 09-16Z SOUTH OF KCSM- KSWO...BUT WAS NOT MENTIONED DUE TO LOW CONFIDENCE. 30/17 && .PREV DISCUSSION... /ISSUED 252 PM CDT SAT JUN 20 2015/ DISCUSSION... A MID-LEVEL LOW/SHEAR AXIS OVER TEXAS...WILL AID IN THE DEVELOP OF WIDELY SCATTERED SHOWERS AND STORMS THROUGH SUNDAY. SOUTH CENTRAL AND SOUTHEAST OKLAHOMA WILL HAVE THE BEST OPPORTUNITY FOR RAIN...AS THIS FEATURE MOVES NORTHEAST. MEANWHILE...HEIGHT RISES WILL OCCUR AS AN ELONGATED RIDGE BUILDS OVER THE SOUTHERN PLAINS. BREEZY SOUTHWEST WINDS WILL BACK THIS AFTERNOON/EARLY EVENING. BY EARLY SUNDAY...SOME LOW TO MID CLOUDS SHOULD COVER AT LEAST THE SOUTHERN THIRD OF THE FA. DRY AND HOT WEATHER IS EXPECTED MONDAY THROUGH WEDNESDAY. BY THURSDAY/FRIDAY...A WEST TO NORTHWEST FLOW ALOFT IS EXPECTED ACROSS THE CENTRAL AND SOUTHERN PLAINS. THIS COMBINED WITH A SYSTEM MOVING ACROSS THE NORTHERN PLAINS/UPPER MIDWEST...SHOULD PUSH A COLD FRONT CLOSER TO NORTHERN OKLAHOMA. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 73 92 72 92 / 0 10 10 0 HOBART OK 71 94 72 95 / 0 0 0 0 WICHITA FALLS TX 73 93 73 95 / 10 10 10 10 GAGE OK 71 95 71 95 / 0 0 0 0 PONCA CITY OK 74 95 75 95 / 0 0 0 0 DURANT OK 74 91 72 93 / 30 40 30 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 17/30
AREA FORECAST DISCUSSION
NWS TULSA OK
1206 PM CDT FRI JUN 19 2015 .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. FOR THE 18Z TAFS... VFR CONDITIONS WILL PREVAIL AT ALL SITES THROUGHOUT THE 24 HOUR FORECAST PERIOD. DUE TO THE SATURATED GROUND THERE WILL BE A POSSIBILITY OF PATCHY FOG SATURDAY MORNING. HOWEVER... FORECASTING FOG FOR ANY PARTICULAR SITE WILL BE IMPOSSIBLE AT THIS TIME... SO IS NOT INCLUDED IN ANY TAFS. && .PREV DISCUSSION... /ISSUED 1100 AM CDT FRI JUN 19 2015/ DISCUSSION... HAVE UPDATED THE FORECAST PRODUCTS EARLIER THIS MORNING TO REMOVE ALL POPS FROM THE ENTIRE FORECAST AREA. ALL OTHER FORECAST ELEMENTS REMAIN ON TRACK AT THIS TIME. PREV DISCUSSION... /ISSUED 629 AM CDT FRI JUN 19 2015/ AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. MVFR OR LOWER CEILINGS WILL PREVAIL INTO THIS AFTERNOON AT THE NORTHWEST ARKANSAS TAF SITES. THE EASTERN OKLAHOMA SITES MAY SEE OCCASIONAL MVFR CEILINGS THIS MORNING...BUT VFR WILL BE MOST PREVALENT. ALL SITES WILL BE VFR FROM LATE THIS AFTERNOON THROUGH TONIGHT. PREV DISCUSSION... /ISSUED 249 AM CDT FRI JUN 19 2015/ DISCUSSION... THE CENTER OF BILL HAS EXITED THE TULSA COUNTY WARNING AREA AND IS NOW CENTERED OVER FAR EASTERN JOHNSON COUNTY ARKANSAS. MODERATE RAIN CONTINUES TO WRAP AROUND BILL AND AFFECT NORTHWEST ARKANSAS AT THIS HOUR. WILL KEEP FLASH FLOOD WATCH IN PLACE THROUGH 12Z. MAY TRIM THE OKLAHOMA COUNTIES OUT OF THE WATCH PRIOR TO THE ISSUANCE OF THIS FORECAST PACKAGE. WILL KEEP SOME POPS THROUGH 18Z FOR PORTIONS OF NORTHWEST ARKANSAS. THE HRRR HAS THE BULK OF THE ACTIVITY WELL EAST OF THE FORECAST AREA BY EARLY AFTERNOON. OVER THE WEEKEND AND INTO NEXT WEEK....THE HEAT AND HUMIDITY WILL BE THE BIG STORY. AN UPPER LEVEL RIDGE WILL BUILD INTO THE REGION FROM THE WEST AS HIGH PRESSURE PREVAILS AT THE SURFACE. HIGH TEMPERATURES WILL BE IN THE UPPER 80S TO MID 90S. THE HUMIDITY WILL MAKE IT FEEL EVEN HOTTER. HOWEVER...BELOW HEAT ADVISORY CRITERIA FOR NOW. A WEAK FRONTAL BOUNDARY MAY SNEAK INTO THE NORTHERN PORTIONS OF THE FORECAST AREA LATE NEXT WEEK AS THE UPPER LEVEL RIDGE RETROGRADES TO THE WEST...RESULTING IN A NORTHWESTERLY FLOW ALOFT ACROSS THE REGION. HOWEVER... THIS OCCURS JUST BEYOND THE SCOPE OF THIS FORECAST. && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ SHORT TERM...99 LONG TERM....99 AVIATION...06
AREA FORECAST DISCUSSION
NWS TULSA OK
1100 AM CDT FRI JUN 19 2015 .DISCUSSION... HAVE UPDATED THE FORECAST PRODUCTS EARLIER THIS MORNING TO REMOVE ALL POPS FROM THE ENTIRE FORECAST AREA. ALL OTHER FORECAST ELEMENTS REMAIN ON TRACK AT THIS TIME. && .PREV DISCUSSION... /ISSUED 629 AM CDT FRI JUN 19 2015/ AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. MVFR OR LOWER CEILINGS WILL PREVAIL INTO THIS AFTERNOON AT THE NORTHWEST ARKANSAS TAF SITES. THE EASTERN OKLAHOMA SITES MAY SEE OCCASIONAL MVFR CEILINGS THIS MORNING...BUT VFR WILL BE MOST PREVALENT. ALL SITES WILL BE VFR FROM LATE THIS AFTERNOON THROUGH TONIGHT. PREV DISCUSSION... /ISSUED 249 AM CDT FRI JUN 19 2015/ DISCUSSION... THE CENTER OF BILL HAS EXITED THE TULSA COUNTY WARNING AREA AND IS NOW CENTERED OVER FAR EASTERN JOHNSON COUNTY ARKANSAS. MODERATE RAIN CONTINUES TO WRAP AROUND BILL AND AFFECT NORTHWEST ARKANSAS AT THIS HOUR. WILL KEEP FLASH FLOOD WATCH IN PLACE THROUGH 12Z. MAY TRIM THE OKLAHOMA COUNTIES OUT OF THE WATCH PRIOR TO THE ISSUANCE OF THIS FORECAST PACKAGE. WILL KEEP SOME POPS THROUGH 18Z FOR PORTIONS OF NORTHWEST ARKANSAS. THE HRRR HAS THE BULK OF THE ACTIVITY WELL EAST OF THE FORECAST AREA BY EARLY AFTERNOON. OVER THE WEEKEND AND INTO NEXT WEEK....THE HEAT AND HUMIDITY WILL BE THE BIG STORY. AN UPPER LEVEL RIDGE WILL BUILD INTO THE REGION FROM THE WEST AS HIGH PRESSURE PREVAILS AT THE SURFACE. HIGH TEMPERATURES WILL BE IN THE UPPER 80S TO MID 90S. THE HUMIDITY WILL MAKE IT FEEL EVEN HOTTER. HOWEVER...BELOW HEAT ADVISORY CRITERIA FOR NOW. A WEAK FRONTAL BOUNDARY MAY SNEAK INTO THE NORTHERN PORTIONS OF THE FORECAST AREA LATE NEXT WEEK AS THE UPPER LEVEL RIDGE RETROGRADES TO THE WEST...RESULTING IN A NORTHWESTERLY FLOW ALOFT ACROSS THE REGION. HOWEVER... THIS OCCURS JUST BEYOND THE SCOPE OF THIS FORECAST. && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ SHORT TERM...06 LONG TERM....99
AREA FORECAST DISCUSSION
NWS TULSA OK
629 AM CDT FRI JUN 19 2015 .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. MVFR OR LOWER CEILINGS WILL PREVAIL INTO THIS AFTERNOON AT THE NORTHWEST ARKANSAS TAF SITES. THE EASTERN OKLAHOMA SITES MAY SEE OCCASIONAL MVFR CEILINGS THIS MORNING...BUT VFR WILL BE MOST PREVALENT. ALL SITES WILL BE VFR FROM LATE THIS AFTERNOON THROUGH TONIGHT. && .PREV DISCUSSION... /ISSUED 249 AM CDT FRI JUN 19 2015/ DISCUSSION... THE CENTER OF BILL HAS EXITED THE TULSA COUNTY WARNING AREA AND IS NOW CENTERED OVER FAR EASTERN JOHNSON COUNTY ARKANSAS. MODERATE RAIN CONTINUES TO WRAP AROUND BILL AND AFFECT NORTHWEST ARKANSAS AT THIS HOUR. WILL KEEP FLASH FLOOD WATCH IN PLACE THROUGH 12Z. MAY TRIM THE OKLAHOMA COUNTIES OUT OF THE WATCH PRIOR TO THE ISSUANCE OF THIS FORECAST PACKAGE. WILL KEEP SOME POPS THROUGH 18Z FOR PORTIONS OF NORTHWEST ARKANSAS. THE HRRR HAS THE BULK OF THE ACTIVITY WELL EAST OF THE FORECAST AREA BY EARLY AFTERNOON. OVER THE WEEKEND AND INTO NEXT WEEK....THE HEAT AND HUMIDITY WILL BE THE BIG STORY. AN UPPER LEVEL RIDGE WILL BUILD INTO THE REGION FROM THE WEST AS HIGH PRESSURE PREVAILS AT THE SURFACE. HIGH TEMPERATURES WILL BE IN THE UPPER 80S TO MID 90S. THE HUMIDITY WILL MAKE IT FEEL EVEN HOTTER. HOWEVER...BELOW HEAT ADVISORY CRITERIA FOR NOW. A WEAK FRONTAL BOUNDARY MAY SNEAK INTO THE NORTHERN PORTIONS OF THE FORECAST AREA LATE NEXT WEEK AS THE UPPER LEVEL RIDGE RETROGRADES TO THE WEST...RESULTING IN A NORTHWESTERLY FLOW ALOFT ACROSS THE REGION. HOWEVER... THIS OCCURS JUST BEYOND THE SCOPE OF THIS FORECAST. && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...FLASH FLOOD WATCH UNTIL 7 AM FRIDAY FOR ARZ002-ARZ011-ARZ020. && $$ AVIATION...05
AREA FORECAST DISCUSSION
NWS TULSA OK
249 AM CDT FRI JUN 19 2015 .DISCUSSION... THE CENTER OF BILL HAS EXITED THE TULSA COUNTY WARNING AREA AND IS NOW CENTERED OVER FAR EASTERN JOHNSON COUNTY ARKANSAS. MODERATE RAIN CONTINUES TO WRAP AROUND BILL AND AFFECT NORTHWEST ARKANSAS AT THIS HOUR. WILL KEEP FLASH FLOOD WATCH IN PLACE THROUGH 12Z. MAY TRIM THE OKLAHOMA COUNTIES OUT OF THE WATCH PRIOR TO THE ISSUANCE OF THIS FORECAST PACKAGE. WILL KEEP SOME POPS THROUGH 18Z FOR PORTIONS OF NORTHWEST ARKANSAS. THE HRRR HAS THE BULK OF THE ACTIVITY WELL EAST OF THE FORECAST AREA BY EARLY AFTERNOON. OVER THE WEEKEND AND INTO NEXT WEEK....THE HEAT AND HUMIDITY WILL BE THE BIG STORY. AN UPPER LEVEL RIDGE WILL BUILD INTO THE REGION FROM THE WEST AS HIGH PRESSURE PREVAILS AT THE SURFACE. HIGH TEMPERATURES WILL BE IN THE UPPER 80S TO MID 90S. THE HUMIDITY WILL MAKE IT FEEL EVEN HOTTER. HOWEVER...BELOW HEAT ADVISORY CRITERIA FOR NOW. A WEAK FRONTAL BOUNDARY MAY SNEAK INTO THE NORTHERN PORTIONS OF THE FORECAST AREA LATE NEXT WEEK AS THE UPPER LEVEL RIDGE RETROGRADES TO THE WEST...RESULTING IN A NORTHWESTERLY FLOW ALOFT ACROSS THE REGION. HOWEVER... THIS OCCURS JUST BEYOND THE SCOPE OF THIS FORECAST. && .PRELIMINARY POINT TEMPS/POPS... TUL 88 73 93 76 / 10 0 10 10 FSM 86 72 94 73 / 30 10 10 10 MLC 87 71 90 75 / 10 10 10 0 BVO 88 69 94 72 / 0 0 10 10 FYV 81 64 89 70 / 40 10 10 10 BYV 79 66 91 71 / 70 10 10 10 MKO 86 70 90 73 / 10 10 10 10 MIO 84 69 92 74 / 10 0 10 10 F10 87 71 90 74 / 10 10 10 10 HHW 89 71 90 73 / 10 10 10 10 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...FLASH FLOOD WATCH UNTIL 7 AM FRIDAY FOR OKZ058-OKZ063-OKZ068- OKZ069. AR...FLASH FLOOD WATCH UNTIL 7 AM FRIDAY FOR ARZ001-ARZ002-ARZ010- ARZ011-ARZ019-ARZ020. && $$ SHORT TERM...05 LONG TERM....10
AREA FORECAST DISCUSSION
NWS NORMAN OK
247 AM CDT FRI JUN 19 2015 .UPDATE... ADDED PRECIP/WX TO W/NW OKLAHOMA THIS MORNING... && .DISCUSSION... AN ISOLATED AREA OF THUNDERSTORMS HAS DEVELOPED ALONG A NARROW AXIS OF MID-LEVEL MOISTURE AND LIFT ACROSS THE NERN TX/ERN OK PANHANDLES THIS MORNING. OVERALL... FOR THE PAST HOUR... THIS ACTIVITY HAS REMAINED FAIRLY STATIONARY. HOWEVER... RECENT RUNS OF THE HRRR SUGGEST A FEW STORMS MAY DRIFT SLOWLY EASTWARD INTO W/NW OK AS THE SFC/MID-LVL TROUGH GRADUALLY SHIFTS EASTWARD THROUGH SUNRISE. GIVEN MLCAPES OF 1000-1500 J/KG AND MINIMAL CIN... HAVE NO QUALMS WITH THE HRRR SOLUTION... EXCEPT IT MAY BE A TAD AGGRESSIVE. WILL KEEP CHANCE POPS THROUGH SUNRISE... WITH SLIGHT CHANCE THROUGH MID MORNING. JTK && .PREV DISCUSSION... /ISSUED 929 PM CDT THU JUN 18 2015/ DISCUSSION... HAVE REMOVED MENTION OF RAIN/STORMS FOR TONIGHT THROUGHOUT OUR FORECAST AREA. IT APPEARS THAT SUBSIDENCE BEHIND THE DEPARTING TROPICAL DEPRESSION WILL SUPPRESS ANY CONVECTION OVER OUR EASTERN COUNTIES THIS EVENING...AND THAT THE TEXAS PANHANDLE CONVECTION WILL CONTINUE TO SPREAD SOUTHWEST...AWAY FROM OUR AREA. SEVERAL MODELS DO SHOW SOME RAIN IN OUR FAR WESTERN COUNTIES LATE TONIGHT...BUT THERE DOES NOT APPEAR TO BE ANY ACTUAL MECHANISM TO BRING THAT ABOUT. WILL HAVE TO WATCH FOR ANY HINTS THAT THIS WILL HAPPEN...BUT WILL NOT INTRODUCE ANY CHANCES AT THIS TIME. OTHERWISE...THE CURRENT FORECAST LOOKS GOOD...AND NO OTHER CHANGES ARE PLANNED FOR THIS EVENING. PREV DISCUSSION... /ISSUED 359 PM CDT THU JUN 18 2015/ DISCUSSION... THE CIRCULATION WITH REMNANTS OF BILL IS JUST EAST OF FORT SMITH THIS AFTERNOON. WIDELY SCATTERED SHOWERS WILL CONTINUE TO MOVE ACROSS EASTERN OKLAHOMA INTO THE EARLY EVENING...MAINLY ALONG AND EAST OF A SHAWNEE TO ADA AND DURANT LINE. BRIEF HEAVY DOWNPOURS ARE POSSIBLE BUT OVERALL RAINFALL AMOUNTS WILL BE LIGHT. OTHER ISOLATED STORMS HAVE DEVELOP IN THE TEXAS PANHANDLE ALONG AN OUTFLOW BOUNDARY. STORMS ARE EXPECTED TO MOVE SOUTH AND SOUTHWEST SO STORM CHANCES IN FAR WESTERN OKLAHOMA WILL REMAIN RATHER LOW. CLOUD COVER WILL DECREASE THIS EVENING...ESPECIALLY ACROSS THE WESTERN HALF OF OKLAHOMA. THIS COMBINED WITH LIGHT WINDS BY EARLY FRIDAY MORNING MAY RESULT IN SOME LIGHT FOG. OVER THE NEXT SEVERAL DAYS...RIDGING OVER SOUTHERN CALIFORNIA AND THE DESERT SOUTHWEST WILL BUILD EAST. THIS WILL RESULT IN MAINLY DRY WEATHER...WITH HOT AND MUGGY CONDITIONS THROUGH AT LEAST THE MIDDLE OF NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 89 71 92 71 / 10 10 0 0 HOBART OK 93 71 96 71 / 10 0 0 0 WICHITA FALLS TX 93 72 94 72 / 10 0 0 0 GAGE OK 91 71 96 71 / 20 0 0 0 PONCA CITY OK 89 73 96 75 / 0 0 0 0 DURANT OK 90 72 91 73 / 10 10 0 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 04/17
AREA FORECAST DISCUSSION
NWS PORTLAND OR
917 AM PDT FRI JUN 19 2015 .SYNOPSIS...LOW PRESSURE MOVING INTO BRITISH COLUMBIA WILL PUSH THE TAIL END OF A COLD FRONT THROUGH SOUTHWEST WASHINGTON AND NORTHWEST OREGON THIS MORNING...BRINGING A CHANCE OF LIGHT RAIN OR DRIZZLE TO AREAS NORTH OF SALEM. A FEW SHOWERS MAY LINGER INTO THE AFTERNOON IN THE HIGHER TERRAIN. CLOUD COVER AND COOLER AIR BEHIND THE FRONT SHOULD KEEP TEMPERATURES CLOSER TO JUNE NORMALS FRIDAY. HOWEVER TEMPERATURES WILL BE QUICK TO REBOUND BACK ABOVE NORMAL THIS WEEKEND AS HIGH PRESSURE MOVES ACROSS THE REGION. ANOTHER UPPER TROUGH AND SLIGHT COOL DOWN APPEAR LIKELY EARLY NEXT WEEK...BUT NO SIGNIFICANT RAIN IS EXPECTED. && .SHORT TERM...MORNING UPDATE...WEAK SURFACE FRONT DISSIPATING ALONG THE COAST STILL PUSHING SOME LIGHT PRECIPITATION ALONG THE SW WASHINGTON/FAR NW OREGON COAST...RIGHT AROUND ASTORIA. RADAR IMAGERY SHOWS A BAND OF LIGHT SHOWERS WEAKENING AS IT DRIFTS A LITTLE SOUTHWARD INTO THE COAST RANGE THIS MORNING. THIS BAND BROUGHT 0.18" OF MEASURABLE PRECIPITATION TO KAST...WHILE SURROUNDING COASTAL CITIES SUCH AS TILLAMOOK SAW 0.02" IN THE PAST 6 HOURS. COULD STILL SEE SOME LIGHT DRIZZLE GET SQUEEZED OUT OF THIS BAND AS THE TROUGH SHIFTS FURTHER INLAND LATER THIS MORNING. THE 15Z HRRR DATA IS SUGGESTING THE MAIN THREAT FOR DRIZZLE/LIGHT RAIN OVER THE COAST RANGE AND JUST CLIPPING THE NORTHERN VALLEYS. LOCATIONS SOUTH OF WILSONVILLE WILL STAY DRY. HIGHS TODAY WILL BE THE COOLEST INLAND THROUGH THE SHORT TERM PERIOD WITH HIGHS IN THE MID TO UPPER 70S. /27 FLOW THEN REMAINS RATHER ZONAL ACROSS THE PACIFIC NORTHWEST THROUGH SATURDAY MORNING...SO THERE IS A REASONABLE CHANCE OF LOW CLOUDS PUSHING INLAND SATURDAY MORNING...ESPECIALLY UP THE COLUMBIA TOWARD THE PDX METRO. MODELS ARE NOT SUGGESTING MUCH CLOUD COVER SAT MORNING AND SINCE THEY HAVE ACTUALLY BEEN OVERDOING THE INLAND EXTENT OF LOW CLOUDS THE PAST COUPLE WEEKS WILL BACK OFF ON INLAND CLOUD COVER. SUNDAY SHOULD BE EVEN WARMER AS FLOW ALOFT TURNS MORE S-SWLY AND ONSHORE PRESSURE GRADIENTS WEAKEN AND MAY GO BRIEFLY OFFSHORE IN THE MORNING. 00Z GFS/00Z ECMWF SUGGEST THERMAL LOW PRESSURE WILL START SUNDAY OVER THE WILLAMETTE VALLEY...MOVING ACROSS THE CASCADES SUNDAY AFTERNOON. WILL NEED TO WATCH FOR THE POSSIBILITY OF THUNDER ON THE CASCADE CREST SUNDAY AFTERNOON AS FLOW ALOFT BECOMES INCREASINGLY DIFFLUENT AHEAD OF AN APPROACHING SHORTWAVE. LOW-LEVEL INSTABILITY DUE TO THE THERMAL TROUGH CROSSING THE CASCADES COULD PROVIDE AN ASSIST TO SURFACE-BASED CONVECTION... ESPECIALLY WITH THE SYNOPTIC TRIGGERS ALOFT. WILL LEAVE THUNDER OUT OF THE FORECAST FOR NOW...AS SW FLOW ALOFT IS NOT OFTEN FAVORABLE FOR THUNDER ON OUR SIDE OF THE CASCADE CREST. WEAGLE /26 .LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...SUNDAY NIGHT THROUGH THURSDAY...OVERALL DRY WITH MORNING CLOUDS WILL CONTINUE THROUGH THE EXTENDED PERIOD. AN UPPER LEVEL TROUGH WILL MOVE ACROSS THE PACIFIC NORTHWEST LATE SUNDAY INTO MONDAY...TRIGGERING A BRIEF COOLDOWN FOR MONDAY WITH MORE OF A MARINE PUSH BRINGING MORE MARINE STRATUS TO INLAND VALLEYS. THE ECMWF IS A LITTLE FASTER IN PUSHING THE TROUGH FARTHER EAST OF THE AREA BY TUESDAY...WHILE THE GFS KEEPS IT LINGERING OVERHEAD THROUGH TUESDAY NIGHT. SHOULD SEE A PERIOD OF JUST BELOW OR RIGHT NEAR NORMAL TEMPERATURES TUESDAY AND WEDNESDAY...BEFORE MORE UPPER LEVEL RIDGING DEVELOPS BY THE MIDDLE OF NEXT WEEK. BOTH MODELS ARE HINTING AT A THERMAL TROUGH SETTING UP OVER THE SOUTH COAST BY TUESDAY NIGHT...AND IF THE GFS GETS ITS WAY WE COULD SEE IT STRENGTHENING AND LASTING LATE INTO THE WEEK. /27 && .AVIATION...REMNANTS OF WEAK FRONT OVER THE REGION...BUT BIG SPREAD IN CONDITIONS. IFR ON UNDER THICKEST DECK AFFECTING FAR NW CORNER...WITH MVFR FURTHER INLAND TOWARDS COWLITZ VALLEY AND S WASHINGTON CASCADES. TO SOUTH OF THAT...MOSTLY VFR WITH CIGS NEAR 4000 FT TO KSLE...THEN SCATTERED CLOUDS TO SOUTH OF KSLE. OVERALL NOT A LOT OF CHANGE THIS AM...BUT WILL TREND TO GENERALLY VFR FOR ALL AREAS THIS AFTERNOON...WITH SCT TO BKN CIGS AROUND 4500 FT. CIGS WILL REFORM TONIGHT UNDER LIGHT TO MODERATE ONSHORE FLOW. KPDX AND APPROACHES...VFR TODAY...WITH CIGS 4000 TO 4500 FT UNTIL 22Z...THEN SCATTERED CLOUDS. CIGS LIKELY TO REFORM AFTER 05Z AS MARINE LAYER COOLS...BUT SHOULD REMAIN LOW VFR. ROCKEY. && .MARINE...NOT A LOT OF CHANGE. WINDS 15 KT OR LESS TODAY AND TONIGHT...WITH SEAS 2 TO 4 FT. HIGH PRES WILL REBUILD OVER THE PAC NW ON SAT...WITH RETURN OF GUSTY N WINDS...MAINLY FOR THE CENTRAL OREGON COASTAL WATERS. LIKELY NEED AN ADVISORY FOR THAT AREA ON SAT INTO EARLY SUN AS WINDS GUST 20 TO 25 KT. IN CONJUNCTION WITH THE WINDS...SEAS WILL BUILD UP A TAD...WITH 4 TO 5 FT AND CHOPPY. ANOTHER WEAK FRONT WILL PASS ACROSS REGION LATER SUN AND MON WITH ANOTHER PERIOD OF WEAKER WINDS. BUT AFTERWARDS...NORTHERLY WINDS INCREASE AGAIN AS N TO S PRES GRADIENTS BUILD. ROCKEY. && .PQR WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. PZ...NONE. && && .PQR WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. PZ...NONE. && $$ INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/NWSPORTLAND WWW.TWITTER.COM/NWSPORTLAND THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
425 PM EDT SAT JUN 20 2015 .SYNOPSIS... THE MOISTURE WITH THE REMNANTS OF TROPICAL STORM BILL WILL BRING CLOUDS AND RAIN TO THE REGION OVER THE NEXT 18 TO 24 HOURS. SOME HEAVY RAIN IS POSSIBLE MAINLY IN THE SOUTHEAST. A COLD FRONT SWEEPS THROUGH THE REGION SUNDAY. COOLER AND DRIER AIR MOVES SUNDAY NIGHT INTO MONDAY. THE REGION WILL BE IN WEAK WESTERLY FLOW JUST NORTH OF A MONSTER SUBTROPICAL RIDGE. WE WILL BE ON THE NORTHERN EDGE OF THIS SYSTEM SO THE WEEK LOOKS RELATIVELY DRY BUT QUITE WARM. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... SEVERE THUNDERSTORM WATCH ISSUED FOR SOUTHERNMOST COUNTIES THIS AFTERNOON AND EVENING. INSTABILITY...STRONG SHEAR AND BANDS ABOUT THE CIRCULATION ASSOCIATED WITH THE REMNANTS OF BILL COULD PRODUCE SEVERE STORMS. AT THIS TIME HIGHEST THREAT ACROSS OUR SOUTHERN TIER AND SOUTH. HRRR SHOWS MORE LINEAR LOOKING CONVECTION IMPLYING HIGH WIND POTENTIAL. ANY TORNADOES WOULD BE ISOLATED AND RELATIVELY WEAK. MODELS SHOW LOTS OF ISSUES WITH CONFIDENCE IN THE RAIN THIS EVENING AND OVERNIGHT. NCEP GEFS/GFS AND THE 16Z HRRR SHIFTED THE THREAT TO THE NORTH. AWAIT MORE GUIDANCE BEFORE WE MAKE ANY BIG CHANGES. GEFS SHOWS 20 PERCENT CHANCE OF 2 OR MORE INCHES NORTH OF OUR CURRENT FLOOD WATCH. BUT SOME INCONSISTENCIES SO MADE NO BIG CHANGES. GOOD CHANCE OF 1 TO 2 INCHES IN OUR EASTERN AREAS OVERNIGHT AS THE CIRCULATION MOVES ON BY. MOST GUIDANCE SHOWS QUICK END TO RAINFALL IN THE 11 TO 2 AM TIMEFRAME. AMOUNTS LOWER TO THE NORTH AND WEST. WHERE THE CONVECTION SETS AND MOVES THROUGH UP WILL DICTATE THE AREA OF HEAVIEST RAINFALL. AREAS OF PATCHY FOG WILL DEVELOP BEHIND THE RAIN BEFORE AND AROUND SUNRISE. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/... BACK EDGE OF THE BILL/TROPICAL RELATED RAINFALL IN THE SREF PASSES EAST OF OUR REGION BETWEEN 8 AND 10 AM SUNDAY. LINGERING SHOWERS POSSIBLE IN THE EASTERNMOST AREAS. THERE IS A POP AND PW MINIMUM BETWEEN THIS SYSTEM AND THE APPROACHING COLD FRONT TO THE WEST. THIS COULD ALLOW FOR SOME HEATING AND THE MODELS ALL SHOW A SECOND BAND OF SHOWERS AND THUNDERSTORMS IN THE AFTERNOON MOVING WEST TO EAST ACROSS THE REGION. THE DRIER AIR AND LOWER PWS BEGIN TO MOVE LATE SUNDAY AFTERNOON AND EVENING. EARLY IN THE WEST. NEXT PERIOD SUNDAY NIGHT INTO MONDAY IS WHEN IT REALLY SHOULD DRY OUT ACROSS OUR REGION. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... FAST ZONAL FLOW WILL BE THE PERSISTENT SYNOPTIC FEATURE ACROSS THE LOWER 48 DURING THE LONG TERM PERIOD...AND THE DRYING OF SUNDAY EVENING INTO MONDAY WILL BE SHORT-LIVED. WITH A HOT 594DM 500 MB UPPER RIDGE CENTERED FROM THE TEXAS PANHANDLE TO THE MID TENNESSEE RIVER VALLEY ON TUESDAY...RETURN FLOW OF MOISTURE AND ANOTHER FRONTAL SYSTEM WILL MOVE ACROSS THE REGION TUESDAY NIGHT AND WEDNESDAY WITH ANOTHER CHANCE OF SHOWERS AND THUNDERSTORMS. THIS BOUNDARY NOW APPEARS TO STALL OUT ALONG OR SOUTH OF THE PA/MD BORDER FOR THE REMAINDER OF THE WEEK...GIVING SOME HOPE OF A PROLONGED PERIOD OF DRIER WEATHER TO AT LEAST NORTHERN PA. HOWEVER...JUST A SLIGHT NORTHWARD OSCILLATION IN THE PATTERN WOULD NUDGE MOISTURE AND SHOWER CHANCES BACK TO THE NORTH. && .AVIATION /21Z SATURDAY THROUGH THURSDAY/... THE REMNANTS OF BILL WILL BE PUSHING ACROSS THE MID-ATLANTIC OVERNIGHT BRINING RAIN AND LOW CIGS TO THE REGION FROM WEST TO EAST THIS MORNING AND EARLY TONIGHT. THUNDERSTORMS ARE POSSIBLE IN SOUTHERN PA IN THE WARMER AIR. WEAK BANDS ARE ALREADY MOVING ACROSS WESTERN/WEST CENTRAL PA. MODIFIED THE TAFS TO SHOW THE MVFR/VFR MOVING MORE STEADILY THIS AFTERNOON/EVENING AS THE RAIN FILLS IN OVERTIME. THE HIGH RESOLUTION GUIDANCE SUGGEST 23Z TO 04Z WILL BE PEAK LOWERED CIGS/VSBY WITH RAIN AND SCATTERED THUNDERSTORMS. THE RAIN AND MOIST AIR WILL PRODUCE FOG AS THE STEADIER RAINFALL LIFTS TO OUR EAST. COULD BE SOME BREAKS IN CLOUDS AS COLD FRONT APPROACHES IN THE AFTERNOON. THIS FEATURE COULD TRIGGER A ROUND OF SHOWERS AND THUNDERSTORMS BEFORE DRIER AIR MOVES IN. MONDAY LOOKS RELATIVELY QUIET...WE WILL BE ON THE EDGE OF A MASSIVE RIDGE WHICH IMPLIES WARM DAYS AND MVFR POSSIBLE IN FOG/HAZE IN MORNINGS. PERHAPS EVEN AFTERNOON THUNDERSTORMS BY MID-WEEK. OUTLOOK... MON...GENERALLY VFR. TUE...REDUCTIONS PSBL IN SCT SHRA/TSRA. WED-THU...GENERALLY VFR AREAS AM MVFR IN FOG/HAZE. && .CTP WATCHES/WARNINGS/ADVISORIES... FLOOD WATCH FROM 8 PM EDT THIS EVENING THROUGH SUNDAY EVENING FOR PAZ033>036-056>059-063>066. && $$ SYNOPSIS...GRUMM NEAR TERM...GRUMM SHORT TERM...GRUMM LONG TERM...DEVOIR/GARTNER AVIATION...GRUMM
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
241 PM EDT SAT JUN 20 2015 .SYNOPSIS... THE MOISTURE WITH THE REMNANTS OF TROPICAL STORM BILL WILL BRING CLOUDS AND RAIN TO THE REGION OVER THE NEXT 18 TO 24 HOURS. SOME HEAVY RAIN IS POSSIBLE MAINLY IN THE SOUTHEAST. A COLD FRONT SWEEPS THROUGH THE REGION SUNDAY. COOLER AND DRIER AIR MOVES SUNDAY NIGHT INTO MONDAY. THE REGION WILL BE IN WEAK WESTERLY FLOW JUST NORTH OF A MONSTER SUBTROPICAL RIDGE. WE WILL BE ON THE NORTHERN EDGE OF THIS SYSTEM SO THE WEEK LOOKS RELATIVELY DRY BUT QUITE WARM. && .NEAR TERM /THROUGH TONIGHT/... SEVERE THUNDERSTORM WATCH ISSUED FOR SOUTHERNMOST COUNTIES THIS AFTERNOON AND EVENING. INSTABILITY...STRONG SHEAR AND BANDS ABOUT THE CIRCULATION ASSOCIATED WITH THE REMNANTS OF BILL COULD PRODUCE SEVERE STORMS. AT THIS TIME HIGHEST THREAT ACROSS OUR SOUTHERN TIER AND SOUTH. HRRR SHOWS MORE LINEAR LOOKING CONVECTION IMPLYING HIGH WIND POTENTIAL. ANY TORNADOES WOULD BE ISOLATED AND RELATIVELY WEAK. MODELS SHOW LOTS OF ISSUES WITH CONFIDENCE IN THE RAIN THIS EVENING AND OVERNIGHT. NCEP GEFS/GFS AND THE 16Z HRRR SHIFTED THE THREAT TO THE NORTH. AWAIT MORE GUIDANCE BEFORE WE MAKE ANY BIG CHANGES. GEFS SHOWS 20 PERCENT CHANCE OF 2 OR MORE INCHES NORTH OF OUR CURRENT FLOOD WATCH. BUT SOME INCONSISTENCIES SO MADE NO BIG CHANGES. GOOD CHANCE OF 1 TO 2 INCHES IN OUR EASTERN AREAS OVERNIGHT AS THE CIRCULATION MOVES ON BY. MOST GUIDANCE SHOWS QUICK END TO RAINFALL IN THE 11 TO 2 AM TIMEFRAME. AMOUNTS LOWER TO THE NORTH AND WEST. WHERE THE CONVECTION SETS AND MOVES THROUGH UP WILL DICTATE THE AREA OF HEAVIEST RAINFALL. AREAS OF PATCHY FOG WILL DEVELOP BEHIND THE RAIN BEFORE AND AROUND SUNRISE. && .SHORT TERM /SUNDAY/... BACK EDGE OF THE BILL/TROPICAL RELATED RAINFALL IN THE SREF PASSES EAST OF OUR REGION BETWEEN 8 AND 10 AM SUNDAY. LINGERING SHOWERS POSSIBLE IN THE EASTERNMOST AREAS. THERE IS A POP AND PW MINIMUM BETWEEN THIS SYSTEM AND THE APPROACHING COLD FRONT TO THE WEST. THIS COULD ALLOW FOR SOME HEATING AND THE MODELS ALL SHOW A SECOND BAND OF SHOWERS AND THUNDERSTORMS IN THE AFTERNOON MOVING WEST TO EAST ACROSS THE REGION. THE DRIER AIR AND LOWER PWS BEGIN TO MOVE LATE SUNDAY AFTERNOON AND EVENING. EARLY IN THE WEST. NEXT PERIOD SUNDAY NIGHT INTO MONDAY IS WHEN IT REALLY SHOULD DRY OUT ACROSS OUR REGION. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... FAST ZONAL FLOW WILL BE THE PERSISTENT SYNOPTIC FEATURE ACROSS THE LOWER 48 THIS WEEK...AND THE DRYING OF SUNDAY EVENING INTO MONDAY WILL BE SHORT-LIVED. WITH A HOT 594DM 500 MB UPPER RIDGE CENTERED FROM THE TEXAS PANHANDLE TO THE MID TENNESSEE RIVER VALLEY ON TUESDAY...RETURN FLOW OF MOISTURE AND ANOTHER FRONTAL SYSTEM WILL MOVE ACROSS THE REGION TUESDAY NIGHT AND WEDNESDAY WITH ANOTHER CHANCE OF SHOWERS AND THUNDERSTORMS. THIS BOUNDARY NOW APPEARS TO STALL OUT ALONG OR SOUTH OF THE PA/MD BORDER FOR THE REMAINDER OF THE WEEK...GIVING SOME HOPE OF A PROLONGED PERIOD OF DRIER WEATHER TO AT LEAST NORTHERN PA. HOWEVER...JUST A SLIGHT NORTHWARD OSCILLATION IN THE PATTERN WOULD NUDGE MOISTURE AND SHOWER CHANCES BACK TO THE NORTH. && .AVIATION /19Z SATURDAY THROUGH THURSDAY/... THE REMNANTS OF BILL WILL BE PUSHING ACROSS THE MID-ATLANTIC OVERNIGHT BRINING RAIN AND LOW CIGS TO THE REGION FROM WEST TO EAST THIS MORNING AND EARLY TONIGHT. THUNDERSTORMS ARE POSSIBLE IN SOUTHERN PA IN THE WARMER AIR. WEAK BANDS ARE ALREADY MOVING ACROSS WESTERN/WEST CENTRAL PA. MODIFIED THE TAFS TO SHOW THE MVFR/VFR MOVING MORE STEADILY THIS AFTERNOON/EVENING AS THE RAIN FILLS IN OVERTIME. THE HIGH RESOLUTION GUIDANCE SUGGEST 23Z TO 04Z WILL BE PEAK LOWERED CIGS/VSBY WITH RAIN AND SCATTERED THUNDERSTORMS. THE RAIN AND MOIST AIR WILL PRODUCE FOG AS THE STEADIER RAINFALL LIFTS TO OUR EAST. COULD BE SOME BREAKS IN CLOUDS AS COLD FRONT APPROACHES IN THE AFTERNOON. THIS FEATURE COULD TRIGGER A ROUND OF SHOWERS AND THUNDERSTORMS BEFORE DRIER AIR MOVES IN. MONDAY LOOKS RELATIVELY QUIET...WE WILL BE ON THE EDGE OF A MASSIVE RIDGE WHICH IMPLIES WARM DAYS AND MVFR POSSIBLE IN FOG/HAZE IN MORNINGS. PERHAPS EVEN AFTERNOON THUNDERSTORMS BY MID-WEEK. OUTLOOK... MON...GENERALLY VFR. TUE...REDUCTIONS PSBL IN SCT SHRA/TSRA. WED-THU...GENERALLY VFR AREAS AM MVFR IN FOG/HAZE. && .CTP WATCHES/WARNINGS/ADVISORIES... FLOOD WATCH FROM 8 PM EDT THIS EVENING THROUGH SUNDAY EVENING FOR PAZ033>036-056>059-063>066. && $$ SYNOPSIS...GRUMM NEAR TERM...GRUMM SHORT TERM...GRUMM LONG TERM...GRUMM AVIATION...GRUMM
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
126 PM EDT SAT JUN 20 2015 .SYNOPSIS... THE MOISTURE WITH THE REMNANTS OF TROPICAL STORM BILL WILL BRING CLOUDS AND RAIN TO THE REGION OVER THE NEXT 18 TO 24 HOURS. SOME HEAVY RAIN IS POSSIBLE MAINLY IN THE SOUTHEAST. A COLD FRONT SWEEPS THROUGH THE REGION SUNDAY. COOLER AND DRIER AIR MOVES SUNDAY NIGHT INTO MONDAY. THE REGION WILL BE IN WEAK WESTERLY FLOW JUST NORTH OF A MONSTER SUBTROPICAL RIDGE. WE WILL BE ON THE NORTHERN EDGE OF THIS SYSTEM SO THE WEEK LOOKS RELATIVELY DRY BUT QUITE WARM. && .NEAR TERM /THROUGH TONIGHT/... UPDATED FORECAST BASED ON SOME NEW GUIDANCE FROM SREF AND HRRR. RADAR SHOWS RAIN CLOSE TO OUR SOUTHWESTERN COUNTIES. THE HRRR IMPLIES A FEW TENTHS OF RAIN LATER THIS MORNING AND EARLY AFTERNOON IN THE SOUTHWEST. MORE ORGANIZED AND WIDESPREAD RAINFALL STILL APPEARS TO COME IN SLOWLY FROM SOUTHWEST TO NORTHEAST TODAY. DESPITE HIGH POPS IN THE 40 AND 50S IN MOST NCEP EFS...HRRR WOULD IMPLY OUR NORTHEASTERNMOST COUNTIES MIGHT NOT SEE RAIN UNTIL THIS EVENING OR EARLY TONIGHT. WILLIAMSPORT GETS RAIN AN HOUR OR SO EITHER SIDE OF 8 PM AND NOTHING TO THE NORTHEAST OF THEIR UNTIL LATER. CENTRAL AND EASTERN AREAS PROBABLY WILL NOT SEE STEADY/WIDESPREAD RAINS UNTIL THIS AFTERNOON. CENTRAL AREAS LIKE STATE COLLEGE ARE IN THE 3 TO 5 PM RANGE FOR RAIN COMING IN AND LIGHT AT FIRST. BY ABOUT 11 PM THE ENTIRE REGION SHOULD SEE RAIN. WITH THE BACK EDGE ALREADY MOVING TOWARD OUR WESTERN COUNTIES. THE HRRR ALSO SHOWS A NICE RAIN BAND WITH SOME EMBEDDED STRONGER CONVECTION. MOST OF THIS IN THE LATEST RUN STAYS TO OUR SOUTH. THE RAINFALL SHOULD RANGE ABOUT 0.5 TO 2.0 INCHES. MOST AREAS IN THE SOUTHEAST SHOULD SEE AN INCH OR MORE. THE SREF AND GEFS DO NOT AGREE BUT NOW THE SREF TOO SHOWS 50 PERCENT CHANCE OF 2 INCHES OR MORE BY EARLY SUNDAY MORNING OF 2 INCHES OF RAINFALL. BEST CHANCE OF 1 TO 3 INCHES OF RAIN WOULD BE IN SOUTH- SOUTHEASTERN AREAS OVERNIGHT. && .SHORT TERM /SUNDAY/... BACK EDGE OF THE BILL/TROPICAL RELATED RAINFALL IN THE SREF PASSES EAST OF OUR REGION BETWEEN 8 AND 10 AM SUNDAY. LINGERING SHOWERS POSSIBLE IN THE EASTERNMOST AREAS. THERE IS A POP AND PW MINIMUM BETWEEN THIS SYSTEM AND THE APPROACHING COLD FRONT TO THE WEST. THIS COULD ALLOW FOR SOME HEATING AND THE MODELS ALL SHOW A SECOND BAND OF SHOWERS AND THUNDERSTORMS IN THE AFTERNOON MOVING WEST TO EAST ACROSS THE REGION. THE DRIER AIR AND LOWER PWS BEGIN TO MOVE LATE SUNDAY AFTERNOON AND EVENING. EARLY IN THE WEST. NEXT PERIOD SUNDAY NIGHT INTO MONDAY IS WHEN IT REALLY SHOULD DRY OUT ACROSS OUR REGION. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... FAST ZONAL FLOW WILL BE THE PERSISTENT SYNOPTIC FEATURE ACROSS THE LOWER 48 THIS WEEK...AND THE DRYING OF SUNDAY EVENING INTO MONDAY WILL BE SHORT-LIVED. WITH A HOT 594DM 500 MB UPPER RIDGE CENTERED FROM THE TEXAS PANHANDLE TO THE MID TENNESSEE RIVER VALLEY ON TUESDAY...RETURN FLOW OF MOISTURE AND ANOTHER FRONTAL SYSTEM WILL MOVE ACROSS THE REGION TUESDAY NIGHT AND WEDNESDAY WITH ANOTHER CHANCE OF SHOWERS AND THUNDERSTORMS. THIS BOUNDARY NOW APPEARS TO STALL OUT ALONG OR SOUTH OF THE PA/MD BORDER FOR THE REMAINDER OF THE WEEK...GIVING SOME HOPE OF A PROLONGED PERIOD OF DRIER WEATHER TO AT LEAST NORTHERN PA. HOWEVER...JUST A SLIGHT NORTHWARD OSCILLATION IN THE PATTERN WOULD NUDGE MOISTURE AND SHOWER CHANCES BACK TO THE NORTH. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... THE REMNANTS OF BILL WILL BE PUSHING ACROSS THE MID-ATLANTIC OVERNIGHT BRINING RAIN AND LOW CIGS TO THE REGION FROM WEST TO EAST THIS MORNING AND EARLY TONIGHT. THUNDERSTORMS ARE POSSIBLE IN SOUTHERN PA IN THE WARMER AIR. WEAK BANDS ARE ALREADY MOVING ACROSS WESTERN/WEST CENTRAL PA. MODIFIED THE TAFS TO SHOW THE MVFR/VFR MOVING MORE STEADILY THIS AFTERNOON/EVENING AS THE RAIN FILLS IN OVERTIME. THE HIGH RESOLUTION GUIDANCE SUGGEST 23Z TO 04Z WILL BE PEAK LOWERED CIGS/VSBY WITH RAIN AND SCATTERED THUNDERSTORMS. THE RAIN AND MOIST AIR WILL PRODUCE FOG AS THE STEADIER RAINFALL LIFTS TO OUR EAST. COULD BE SOME BREAKS IN CLOUDS AS COLD FRONT APPROACHES IN THE AFTERNOON. THIS FEATURE COULD TRIGGER A ROUND OF SHOWERS AND THUNDERSTORMS BEFORE DRIER AIR MOVES IN. MONDAY LOOKS RELATIVELY QUIET...WE WILL BE ON THE EDGE OF A MASSIVE RIDGE WHICH IMPLIES WARM DAYS AND MVFR POSSIBLE IN FOG/HAZE IN MORNINGS. PERHAPS EVEN AFTERNOON THUNDERSTORMS BY MID-WEEK. OUTLOOK... MON...GENERALLY VFR. TUE...REDUCTIONS PSBL IN SCT SHRA/TSRA. WED-THU...GENERALLY VFR AREAS AM MVFR IN FOG/HAZE. && .CTP WATCHES/WARNINGS/ADVISORIES... FLOOD WATCH FROM 8 PM EDT THIS EVENING THROUGH SUNDAY EVENING FOR PAZ033>036-056>059-063>066. && $$ SYNOPSIS...GRUMM NEAR TERM...GRUMM SHORT TERM...GRUMM LONG TERM...GRUMM AVIATION...GRUMM
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1113 AM EDT SAT JUN 20 2015 .SYNOPSIS... THE MOISTURE WITH THE REMNANTS OF TROPICAL STORM BILL WILL BRING CLOUDS AND RAIN TO THE REGION OVER THE NEXT 18 TO 24 HOURS. SOME HEAVY RAIN IS POSSIBLE MAINLY IN THE SOUTHEAST. A COLD FRONT SWEEPS THROUGH THE REGION SUNDAY. COOLER AND DRIER AIR MOVES SUNDAY NIGHT INTO MONDAY. THE REGION WILL BE IN WEAK WESTERLY FLOW JUST NORTH OF A MONSTER SUBTROPICAL RIDGE. WE WILL BE ON THE NORTHERN EDGE OF THIS SYSTEM SO THE WEEK LOOKS RELATIVELY DRY BUT QUITE WARM. && .NEAR TERM /THROUGH TONIGHT/... UPDATED FORECAST BASED ON SOME NEW GUIDANCE FROM SREF AND HRRR. RADAR SHOWS RAIN CLOSE TO OUR SOUTHWESTERN COUNTIES. THE HRRR IMPLIES A FEW TENTHS OF RAIN LATER THIS MORNING AND EARLY AFTERNOON IN THE SOUTHWEST. MORE ORGANIZED AND WIDESPREAD RAINFALL STILL APPEARS TO COME IN SLOWLY FROM SOUTHWEST TO NORTHEAST TODAY. DESPITE HIGH POPS IN THE 40 AND 50S IN MOST NCEP EFS...HRRR WOULD IMPLY OUR NORTHEASTERNMOST COUNTIES MIGHT NOT SEE RAIN UNTIL THIS EVENING OR EARLY TONIGHT. WILLIAMSPORT GETS RAIN AN HOUR OR SO EITHER SIDE OF 8 PM AND NOTHING TO THE NORTHEAST OF THEIR UNTIL LATER. CENTRAL AND EASTERN AREAS PROBABLY WILL NOT SEE STEADY/WIDESPREAD RAINS UNTIL THIS AFTERNOON. CENTRAL AREAS LIKE STATE COLLEGE ARE IN THE 3 TO 5 PM RANGE FOR RAIN COMING IN AND LIGHT AT FIRST. BY ABOUT 11 PM THE ENTIRE REGION SHOULD SEE RAIN. WITH THE BACK EDGE ALREADY MOVING TOWARD OUR WESTERN COUNTIES. THE HRRR ALSO SHOWS A NICE RAIN BAND WITH SOME EMBEDDED STRONGER CONVECTION. MOST OF THIS IN THE LATEST RUN STAYS TO OUR SOUTH. THE RAINFALL SHOULD RANGE ABOUT 0.5 TO 2.0 INCHES. MOST AREAS IN THE SOUTHEAST SHOULD SEE AN INCH OR MORE. THE SREF AND GEFS DO NOT AGREE BUT NOW THE SREF TOO SHOWS 50 PERCENT CHANCE OF 2 INCHES OR MORE BY EARLY SUNDAY MORNING OF 2 INCHES OF RAINFALL. BEST CHANCE OF 1 TO 3 INCHES OF RAIN WOULD BE IN SOUTH- SOUTHEASTERN AREAS OVERNIGHT. && .SHORT TERM /SUNDAY/... BACK EDGE OF THE BILL/TROPICAL RELATED RAINFALL IN THE SREF PASSES EAST OF OUR REGION BETWEEN 8 AND 10 AM SUNDAY. LINGERING SHOWERS POSSIBLE IN THE EASTERNMOST AREAS. THERE IS A POP AND PW MINIMUM BETWEEN THIS SYSTEM AND THE APPROACHING COLD FRONT TO THE WEST. THIS COULD ALLOW FOR SOME HEATING AND THE MODELS ALL SHOW A SECOND BAND OF SHOWERS AND THUNDERSTORMS IN THE AFTERNOON MOVING WEST TO EAST ACROSS THE REGION. THE DRIER AIR AND LOWER PWS BEGIN TO MOVE LATE SUNDAY AFTERNOON AND EVENING. EARLY IN THE WEST. NEXT PERIOD SUNDAY NIGHT INTO MONDAY IS WHEN IT REALLY SHOULD DRY OUT ACROSS OUR REGION. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... FAST ZONAL FLOW WILL BE THE PERSISTENT SYNOPTIC FEATURE ACROSS THE LOWER 48 THIS WEEK...AND THE DRYING OF SUNDAY EVENING INTO MONDAY WILL BE SHORT-LIVED. WITH A HOT 594DM 500 MB UPPER RIDGE CENTERED FROM THE TEXAS PANHANDLE TO THE MID TENNESSEE RIVER VALLEY ON TUESDAY...RETURN FLOW OF MOISTURE AND ANOTHER FRONTAL SYSTEM WILL MOVE ACROSS THE REGION TUESDAY NIGHT AND WEDNESDAY WITH ANOTHER CHANCE OF SHOWERS AND THUNDERSTORMS. THIS BOUNDARY NOW APPEARS TO STALL OUT ALONG OR SOUTH OF THE PA/MD BORDER FOR THE REMAINDER OF THE WEEK...GIVING SOME HOPE OF A PROLONGED PERIOD OF DRIER WEATHER TO AT LEAST NORTHERN PA. HOWEVER...JUST A SLIGHT NORTHWARD OSCILLATION IN THE PATTERN WOULD NUDGE MOISTURE AND SHOWER CHANCES BACK TO THE NORTH. && .AVIATION /15Z SATURDAY THROUGH WEDNESDAY/... REMNANTS OF TS BILL WILL BE PUSHING ACROSS THE MID-ATLANTIC OVERNIGHT BRINING RAIN AND LOW CIGS TO THE REGION FROM WEST TO EAST THIS MORNING AND EARLY TONIGHT. MODIFIED THE TAFS TO SHOW SOME SLOWER ONSET TIMES BASED ON BOTH RADAR AND OUR HIGH RESOLUTION MODEL. SLOWER ONSET OF RAIN AND LOWER CIGS TO EAST AND NORTH. RAIN IS ALREADY MOVING INTO SOMERSET COUNTY AND WILL CONTINUE TO PUSH TO THE NORTH AND EAST. GUIDANCE SHOWS RAIN FROM BILL BEGINS TO END WEST TO EAST AROUND 03Z AND MOST AREAS GO OVER TO SHOWER AND SOME MVFR/IFR IN MIST AND FOG AS SYSTEM MOVES TO OUR EAST IN THE 12Z TIMEFRAME SUNDAY. MODELS SHOW BRIEF LULL IN THE SHOWERS BETWEEN EXITING BILL SUNDAY MORNING AND APPROACHING COLD FRONT...SO SLOW IMPROVEMENT WILL BEGIN SUNDAY...AS THE TROPICAL MOISTURE PULLS OFF THE ATLANTIC COAST. SCT SHRA/TSRA REMAIN POSSIBLE...AS A COLD FRONT CROSSES PA LATE SUNDAY. MONDAY LOOKS RELATIVELY QUIET...BEFORE ANOTHER COLD FRONT CROSSES THE AREA ON TUES WITH A RENEWED CHC FOR SHRA/TSRA. BEHIND THE FRONT...WEDNESDAY SHOULD BE GENERALLY VFR. OUTLOOK... MON...GENERALLY VFR. ISOLATED TSRA POSS...MAINLY WEST. TUE...REDUCTIONS PSBL IN SCT SHRA/TSRA. WED...GENERALLY VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... FLOOD WATCH FROM 8 PM EDT THIS EVENING THROUGH SUNDAY EVENING FOR PAZ033>036-056>059-063>066. && $$ SYNOPSIS...DEVOIR/GARTNER NEAR TERM...GRUMM SHORT TERM...GRUMM LONG TERM...GRUMM AVIATION...GRUMM/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1041 AM EDT SAT JUN 20 2015 .SYNOPSIS... RICH TROPICAL MOISTURE FROM THE REMNANTS OF FORMER TROPICAL STORM BILL WILL PRODUCE SHOWERS AND THUNDERSTORMS ACROSS CENTRAL PENNSYLVANIA THIS AFTERNOON THROUGH SUNDAY. LOCALLY HEAVY RAIN IS POSSIBLE OVER THE SOUTHERN TIER OF PENNSYLVANIA. A DRIER AIR MASS WILL OVERSPREAD PENNSYLVANIA LATE SUNDAY AND MONDAY. ANOTHER FRONTAL SYSTEM WILL TRACK ACROSS THE REGION MONDAY NIGHT INTO TUESDAY AND STALL SOUTH OF PENNSYLVANIA FOR MOST OF NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... UPDATED FORECAST BASED ON SOME NEW GUIDANCE FROM SREF AND HRRR. RADAR SHOWS RAIN CLOSE TO OUR SOUTHWESTERN COUNTIES. THE HRRR IMPLIES A FEW TENTHS OF RAIN LATER THIS MORNING AND EARLY AFTERNOON IN THE SOUTHWEST. MORE ORGANIZED AND WIDESPREAD RAINFALL STILL APPEARS TO COME IN SLOWLY FROM SOUTHWEST TO NORTHEAST TODAY. DESPITE HIGH POPS IN THE 40 AND 50S IN MOST NCEP EFS...HRRR WOULD IMPLY OUR NORTHEASTERNMOST COUNTIES MIGHT NOT SEE RAIN UNTIL THIS EVENING OR EARLY TONIGHT. WILLIAMSPORT GETS RAIN AN HOUR OR SO EITHER SIDE OF 8 PM AND NOTHING TO THE NORTHEAST OF THEIR UNTIL LATER. CENTRAL AND EASTERN AREAS PROBABLY WILL NOT SEE STEADY/WIDESPREAD RAINS UNTIL THIS AFTERNOON. CENTRAL AREAS LIKE STATE COLLEGE ARE IN THE 3 TO 5 PM RANGE FOR RAIN COMING IN AND LIGHT AT FIRST. BY ABOUT 11 PM THE ENTIRE REGION SHOULD SEE RAIN. WITH THE BACK EDGE ALREADY MOVING TOWARD OUR WESTERN COUNTIES. THE HRRR ALSO SHOWS A NICE RAIN BAND WITH SOME EMBEDDED STRONGER CONVECTION. MOST OF THIS IN THE LATEST RUN STAYS TO OUR SOUTH. THE RAINFALL SHOULD RANGE ABOUT 0.5 TO 2.0 INCHES. MOST AREAS IN THE SOUTHEAST SHOULD SEE AN INCH OR MORE. THE SREF AND GEFS DO NOT AGREE BUT NOW THE SREF TOO SHOWS 50 PERCENT CHANCE OF 2 INCHES OR MORE BY EARLY SUNDAY MORNING OF 2 INCHES OF RAINFALL. BEST CHANCE OF 1 TO 3 INCHES OF RAIN WOULD BE IN SOUTH- SOUTHEASTERN AREAS OVERNIGHT. && .SHORT TERM /SUNDAY/... BACK EDGE OF THE BILL/TROPICAL RELATED RAINFALL IN THE SREF PASSES EAST OF OUR REGION BETWEEN 8 AND 10 AM SUNDAY. LINGERING SHOWERS POSSIBLE IN THE EASTERNMOST AREAS. THERE IS A POP AND PW MINIMUM BETWEEN THIS SYSTEM AND THE APPROACHING COLD FRONT TO THE WEST. THIS COULD ALLOW FOR SOME HEATING AND THE MODELS ALL SHOW A SECOND BAND OF SHOWERS AND THUNDERSTORMS IN THE AFTERNOON MOVING WEST TO EAST ACROSS THE REGION. THE DRIER AIR AND LOWER PWS BEGIN TO MOVE LATE SUNDAY AFTERNOON AND EVENING. EARLY IN THE WEST. NEXT PERIOD SUNDAY NIGHT INTO MONDAY IS WHEN IT REALLY SHOULD DRY OUT ACROSS OUR REGION. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... FAST ZONAL FLOW WILL BE THE PERSISTENT SYNOPTIC FEATURE ACROSS THE LOWER 48 THIS WEEK...AND THE DRYING OF SUNDAY EVENING INTO MONDAY WILL BE SHORT-LIVED. WITH A HOT 594DM 500 MB UPPER RIDGE CENTERED FROM THE TEXAS PANHANDLE TO THE MID TENNESSEE RIVER VALLEY ON TUESDAY...RETURN FLOW OF MOISTURE AND ANOTHER FRONTAL SYSTEM WILL MOVE ACROSS THE REGION TUESDAY NIGHT AND WEDNESDAY WITH ANOTHER CHANCE OF SHOWERS AND THUNDERSTORMS. THIS BOUNDARY NOW APPEARS TO STALL OUT ALONG OR SOUTH OF THE PA/MD BORDER FOR THE REMAINDER OF THE WEEK...GIVING SOME HOPE OF A PROLONGED PERIOD OF DRIER WEATHER TO AT LEAST NORTHERN PA. HOWEVER...JUST A SLIGHT NORTHWARD OSCILLATION IN THE PATTERN WOULD NUDGE MOISTURE AND SHOWER CHANCES BACK TO THE NORTH. && .AVIATION /15Z SATURDAY THROUGH WEDNESDAY/... REMNANTS OF TS BILL WILL BE PUSHING EAST ACROSS THE OHIO VALLEY AND MID-ATLANTIC STATES THIS WEEKEND. GENERALLY MVFR CONDITIONS ACROSS THE WESTERN HALF OF CWA WITH VFR IN THE EAST AT 11Z. MVFR CIGS WILL LIKELY SLIP INTO KIPT SHORTLY AND LINGER THROUGH THE MORNING HOURS. BY 18Z...MOST LOCALES SHOULD IMPROVE TO VFR...THOUGH RAIN SHOWERS WILL BE SPREADING IN FROM THE SW AS AS THE CORE OF BILL/S MOISTURE APPROACHES THE MID-ATLANTIC REGION. THERE WILL BE ENOUGH CAPE TO GENERATE SCT TSRA THIS AFT AS WELL...MAINLY ACROSS SOUTHERN PORTION OF CWA. EXPECT THE DEEPEST MOISTURE TO AFFECT SRN PA TONIGHT INTO EARLY SUNDAY...WITH THE POTENTIAL FOR LOCALIZED DOWNPOURS IN SCT TSTMS - AGAIN MAINLY ACROSS THE SOUTH. GENERALLY MVFR RESTRICTIONS DEVELOP AGAIN THIS EVENING...WITH IFR CONDITIONS EXPECTED TO SETTLE IN FOR THE OVERNIGHT. SLOW IMPROVEMENT WILL BEGIN SUNDAY...AS THE TROPICAL MOISTURE PULLS OFF THE ATLANTIC COAST. SCT SHRA/TSRA REMAIN POSSIBLE...AS A COLD FRONT CROSSES PA LATE SUNDAY. MONDAY LOOKS RELATIVELY QUIET...BEFORE ANOTHER COLD FRONT CROSSES THE AREA ON TUES WITH A RENEWED CHC FOR SHRA/TSRA. BEHIND THE FRONT...WEDNESDAY SHOULD BE GENERALLY VFR. OUTLOOK... MON...GENERALLY VFR. ISOLATED TSRA POSS...MAINLY WEST. TUE...REDUCTIONS PSBL IN SCT SHRA/TSRA. WED...GENERALLY VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... FLOOD WATCH FROM 8 PM EDT THIS EVENING THROUGH SUNDAY EVENING FOR PAZ033>036-056>059-063>066. && $$ SYNOPSIS...DEVOIR/GARTNER NEAR TERM...GRUMM SHORT TERM...GRUMM LONG TERM...GRUMM AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
821 AM EDT SAT JUN 20 2015 .SYNOPSIS... RICH TROPICAL MOISTURE FROM THE REMNANTS OF FORMER TROPICAL STORM BILL WILL PRODUCE SHOWERS AND THUNDERSTORMS ACROSS CENTRAL PENNSYLVANIA THIS AFTERNOON THROUGH SUNDAY. LOCALLY HEAVY RAIN IS POSSIBLE OVER THE SOUTHERN TIER OF PENNSYLVANIA. A DRIER AIR MASS WILL OVERSPREAD PENNSYLVANIA LATE SUNDAY AND MONDAY. ANOTHER FRONTAL SYSTEM WILL TRACK ACROSS THE REGION MONDAY NIGHT INTO TUESDAY AND STALL SOUTH OF PENNSYLVANIA FOR MOST OF NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... ADVANCING PLUME OF CLOUDS AND MOISTURE WITH THE SURFACE CIRCULATION OVER THE KY/IN BORDER IS STEADILY MOVING EAST. REGIONAL RADAR SHOWS SOME SHOWERS OVER SOUTHWESTERN PA. HRRR FORECASTS THIS TO WEAKEN...BUT ANOTHER BATCH IS A FEW HOURS BEHIND IT. THE IMPLICATIONS ARE FOR CLOUDY SKIES WITH BETTER CHANCE OF SHOWERS IN SOUTHWEST THIS MORNING. THE RAINFALL SHOULD BECOME MORE WIDESPREAD THIS AFTERNOON AND THIS EVENING. HRRR EVEN IMPLIES SOME CONVECTION WHICH MAY BE ENHANCED RAINFALL RATHER THAN SEVERE WEATHER. SOME OF THE IMPLIED SIGNATURES ARE QUITE STRONG IMPLYING THERE IS POTENTIAL FOR SOME STRONGER LINEAR CONVECTION THIS EVENING ACROSS SOUTHERN AREAS. MOST OF SOUTHERN AND CENTRAL AREAS SHOULD SEE SOME RAIN BY LATE THIS AFTERNOON AND EARLY EVENING. THE RAIN COULD HOLD OFF UNTIL LATER NEAR THE NY BORDER. THE RAINFALL PICKS UP OVERNIGHT WITH EMBEDDED CONVECTION. THE GFS AND GEFS IMPLY AREAS OF 1 TO 2 INCHES AND LOCALLY 3 INCHES IN THE SOUTHEAST. BUT THE SREF AND NAM PUSH THE RAINFALL FARTHER SOUTH AND SHOW ABOUT ONLY 60 TO 70 PERCENT OF THE AMOUNTS. STILL CONSIDERABLE UNCERTAINTY AS TO THE HEAVY RAINFALL POTENTIAL. CONVECTION IN NON-CONVECTIVE ALLOWING MODELS IS ALWAYS A CHALLENGE. && .SHORT TERM /SUNDAY/... MOST GUIDANCE IMPLIES THE HEAVIER AND HIGHER PROBABILITY OF RAINFALL IS BEFORE 8 TO 12 AM. WEATHER CONDITIONS SHOULD IMPROVE WEST TO EAST DURING THE DAY AS THE TROPICAL MOISTURE MOVES EAST. BY LATE DAY SOME AREAS SHOULD EVEN GET SOME GLIMPSES OF THE SUN. AT THIS TIME MOST MODELS SHOW THE COLD FRONT LAGS THE TROPICAL PLUME...SO IN THE AFTERNOON AND EVENING WE WILL HAVE TO DEAL WITH A COLD FRONTAL PASSAGE AND POTENTIAL SHOWERS WITH THAT FEATURE TOO. SHOULD BE MORE SCATTERED AND LESS ORGANIZED. THE REAL DRY AIR BEHIND THIS FRONT COMES IN...IN THE OVERNIGHT SUNDAY TO MONDAY TIMEFRAME. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... FAST ZONAL FLOW WILL BE THE PERSISTENT SYNOPTIC FEATURE ACROSS THE LOWER 48 THIS WEEK...AND THE DRYING OF SUNDAY EVENING INTO MONDAY WILL BE SHORT-LIVED. WITH A HOT 594DM 500 MB UPPER RIDGE CENTERED FROM THE TEXAS PANHANDLE TO THE MID TENNESSEE RIVER VALLEY ON TUESDAY...RETURN FLOW OF MOISTURE AND ANOTHER FRONTAL SYSTEM WILL MOVE ACROSS THE REGION TUESDAY NIGHT AND WEDNESDAY WITH ANOTHER CHANCE OF SHOWERS AND THUNDERSTORMS. THIS BOUNDARY NOW APPEARS TO STALL OUT ALONG OR SOUTH OF THE PA/MD BORDER FOR THE REMAINDER OF THE WEEK...GIVING SOME HOPE OF A PROLONGED PERIOD OF DRIER WEATHER TO AT LEAST NORTHERN PA. HOWEVER...JUST A SLIGHT NORTHWARD OSCILLATION IN THE PATTERN WOULD NUDGE MOISTURE AND SHOWER CHANCES BACK TO THE NORTH. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... REMNANTS OF TS BILL WILL BE PUSHING EAST ACROSS THE OHIO VALLEY AND MID-ATLANTIC STATES THIS WEEKEND. GENERALLY MVFR CONDITIONS ACROSS THE WESTERN HALF OF CWA WITH VFR IN THE EAST AT 11Z. MVFR CIGS WILL LIKELY SLIP INTO KIPT SHORTLY AND LINGER THROUGH THE MORNING HOURS. BY 18Z...MOST LOCALES SHOULD IMPROVE TO VFR...THOUGH RAIN SHOWERS WILL BE SPREADING IN FROM THE SW AS AS THE CORE OF BILL/S MOISTURE APPROACHES THE MID-ATLANTIC REGION. THERE WILL BE ENOUGH CAPE TO GENERATE SCT TSRA THIS AFT AS WELL...MAINLY ACROSS SOUTHERN PORTION OF CWA. EXPECT THE DEEPEST MOISTURE TO AFFECT SRN PA TONIGHT INTO EARLY SUNDAY...WITH THE POTENTIAL FOR LOCALIZED DOWNPOURS IN SCT TSTMS - AGAIN MAINLY ACROSS THE SOUTH. GENERALLY MVFR RESTRICTIONS DEVELOP AGAIN THIS EVENING...WITH IFR CONDITIONS EXPECTED TO SETTLE IN FOR THE OVERNIGHT. SLOW IMPROVEMENT WILL BEGIN SUNDAY...AS THE TROPICAL MOISTURE PULLS OFF THE ATLANTIC COAST. SCT SHRA/TSRA REMAIN POSSIBLE...AS A COLD FRONT CROSSES PA LATE SUNDAY. MONDAY LOOKS RELATIVELY QUIET...BEFORE ANOTHER COLD FRONT CROSSES THE AREA ON TUES WITH A RENEWED CHC FOR SHRA/TSRA. BEHIND THE FRONT...WEDNESDAY SHOULD BE GENERALLY VFR. OUTLOOK... MON...GENERALLY VFR. ISOLATED TSRA POSS...MAINLY WEST. TUE...REDUCTIONS PSBL IN SCT SHRA/TSRA. WED...GENERALLY VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... FLOOD WATCH FROM 8 PM EDT THIS EVENING THROUGH SUNDAY EVENING FOR PAZ033>036-056>059-063>066. && $$ SYNOPSIS...DEVOIR/GARTNER NEAR TERM...GRUMM SHORT TERM...GRUMM LONG TERM...GRUMM AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
231 PM EDT FRI JUN 19 2015 .SYNOPSIS... A DEEPENING TROUGH MOVING OVER THE STRONG RIDGE TO OUR SOUTH WILL DOMINATE OUR WEATHER FOR THE NEXT 7 DAYS. WARM AIR COMING OVER THE RIDGE COMBINED WITH REMAINS OF BILL AND A NORTHERN STREAM SHORT- WAVE WILL KEEP IT UNSETTLED HERE. WITH THE POTENTIAL FOR A SOAKING AND POTENTIALLY HEAVY RAIN EVENT SATURDAY INTO SUNDAY. DRIER AND SLIGHTLY COOLER AIR SHOULD PROVIDE RELATIVELY PLEASANT WORK WEEK AFTER THE WEEKEND RAIN. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... FRONTAL BOUNDARY SAGGING SOUTH ACROSS CWA THIS MORNING. THE MAJORITY OF THE CWA WILL BE DRY TODAY, WITH JUST A FEW LIGHT SHOWERS DRIFTING SOUTH WITH FRONTAL BOUNDARY AND ANOTHER AREA OF SHOWERS MOVING INTO SW PA THIS AFTERNOON...THE FIRST BATCH OF MOISTURE FROM REMNANTS OF BILL. HRRR SHOWS THESE SHOWERS WILL SLIDE ALONG OR SOUTH OF PA/MD BORDER. SATELLITE SHOWS SOME BREAKS IN CLOUDS BUT EXPECT THAT TO FILL IN AND SUNSHINE WILL BE LIMITED ACROSS THE CWA TODAY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... DEWPOINTS SLOWLY DECREASE THIS AFTERNOON AND TONIGHT PROVIDING A MORE COMFORTABLE SLEEPING NIGHT FOR MUCH OF CENTRAL AND NORTH CENTRAL PA. DEWPOINTS ACROSS THE SOUTH WILL REMAIN IN THE LOWER 60S OVERNIGHT. PROXIMITY TO STALLED BOUNDARY ALSO MEANS PRECIP CHANCE CANNOT BE RULED OUT ACROSS THE SOUTHERN THIRD OF CENTRAL PA OVERNIGHT.KEPT SLIGHT CHANCES GOING OVER THE LAUREL HIGHLANDS EXTENDING INTO THE SOUTH CENTRAL MOUNTAINS OVERNIGHT. CENTRAL AND NORTHERN AREAS WILL REMAIN DRY. MINS WILL DROP TO AROUND 50F NORTH TO AROUND 60F SOUTH. MOISTURE GRADUALLY INCREASES AGAIN ON SATURDAY AS QUASI STATIONARY BOUNDARY WAGGLES BACK NORTHWARD. THE DEEPEST MOISTURE ASSOCIATED WITH THE TROPICAL MOISTURE REMNANTS FROM BILL ARE PROGGED TO MOVED THROUGH THE LOWER OHIO VALLEY AND MAINLY SOUTH OF THE MASON DIXON LINE ON SATURDAY. HOWEVER...PRECIPITABLE H20 VALUES 1.5" TO 2.0" ARE EXPECTED BY SATURDAY AFTERNOON...ALONG WITH INCREASING BOUNDARY LAYER CONVERGENCE AND MODERATE CAPES...FUELING SCT TO NMRS SHRA AND TSRA AND SOME LOCALLY HEAVY DOWNPOURS. HIGHS WILL RANGE FROM THE MID 70S NORTH TO AROUND 80 SOUTH. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... THE KEY TO THIS FORECAST PERIOD IS THE POTENTIAL RAINFALL AND POTENTIAL HEAVY RAINFALL SATURDAY NIGHT INTO SUNDAY. THAT WILL BE THE FOCUS. FROM MONDAY UNTIL NEXT THURSDAY...THE GEFS AND NAEFS SHOW LOWER HEIGHTS AND THE HEAT SUPPRESSED TO OUR SOUTH. THUS OUR PRECIPITABLE WATER (PW) DROPS TO NORMAL OR SLIGHTLY BELOW NORMAL MOST OF THIS PERIOD. THIS SHOULD KEEP US ON THE DRIER SIDE WITH NEAR NORMAL 850 HPA TEMPERATURES. THE FOCUS OF THE HOT AIR WILL BE JUST TO OUR SOUTH. BUT THE HIGHER CONFIDENCE FORECAST IS RELATIVELY DRY WITH NEAR NORMAL TEMPERATURES DURING THAT PERIOD. THE BIG ISSUE IS THE DEEP PW PLUME...THE CIRCULATION WITH BILL AND THE SHORTWAVE IN THE NORTHERN STREAM. GUIDANCE SHOWS LOTS OF UNCERTAINTY WITH THE AREA OF HEAVY RAINFALL. THE NCEP GEFS IMPLIES SOME POTENTIAL AT THE 5 TO 40 PERCENT LEVEL OF OVER 2 INCHES OF RAINFALL. AT THE SAME TIME THE 12Z GFS SHOWS AREAS OF OVER 3 INCHES OF RAINFALL IN SOUTH/SOUTHEASTERN PENNSYLVANIA. THIS WOULD BE ABOUT 75 PERCENT OF OUR 100 YEAR RETURN RAINFALL RATE. ANYTHING OVER 50 YEAR RETURNS NORMALLY GIVES US SOME MINOR FLOOD ISSUES TO CONTEND WITH. OUR BLENDS IMPLY MORE LIKE 0.40 TO 1.2 INCHES OVER OUR REGION. BUT CLEARLY THERE ARE INDICATIONS OF HIGHER AMOUNTS. WITH A REMNENANT TROPICAL CIRCULATIONS FORECAST TO PASS OVER OR NEAR SOUTHEASTERN PENNSYLVANIA THE POTENTIAL FOR HIGH END QPF AMOUNTS IS AN ISSUE MAINLY SATURDAY EVENING INTO EARLY SUNDAY. THE PW PEAKS NEAR 50 MM (2 INCHES) AND ABOUT 2 SIGMA ABOVE NORMAL WITH STRONG SOUTHWESTERLY FLOW. ALL SIGNALS POINT TO THE POTENTIAL FOR HEAVY RAINFALL IN THE MID-ATLANTIC REGION. WE JUST DO NOT KNOW WHERE. THE M-CLIMATE SHOWS...SOUTH OF OUR AREA IN THE 00Z GEFS...THAT THE GEFS IS PRODUCING CLOSE TO AN ALL-TIME HIGH QPF EVENT. BUT THIS RAINFALL AXIS OF HIGH QPF WAS SOUTH OUR OUR AREA WITH US ON THE NORTHERN EDGE. NEW GUIDANCE WAS NOT AVAILABLE TO FORECAST TIME. THE 12Z GEFS SEEMS TO HAVE MOVED THIS REGION FARTHER NORTH. IN SUMMARY MOST FORECAST SYSTEM SHOW POTENTIAL BUT MEAN QPF NOT MUCH MORE THAN AN INCH. VALID RANGE IS LIKELY 0.5 TO 3 INCHES AND TIMING AND LOCATION WILL CHANGE. WE FOCUSED OUR RAINFALL IN SOUTHERN AND SOUTHEASTERN PA AND STAYED CLOSE TO THE MEAN. THE HIGH PW WOULD IMPLY EMBEDDED THUNDER COULD EASILY PUT DOWN 1-2 INCHES OVERNIGHT SATURDAY INTO EARLY SUNDAY. THE DRYING OUT SHOULD BEGIN SUNDAY...LOWER POPS LATER IN DAY AND DRY AIR COULD MOVE IN MONDAY. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... BROAD UPPER TROF AND 40KT 850 MB JET DRIVING AREA OF RAIN AND SCT CONVECTION TO CENTRAL PA EARLY THIS MORNING. OVERALL AREA IS SLOWLY DIMINISHING...BUT SCT SHRA/TSTMS WILL REMAIN POSS WITH ACTIVITY SHIFTING TO THE NORTHERN MTNS THROUGH THE OVERNIGHT. MVFR/IFR CIGS SHOULD SETTLE IN OVER NORTHERN AND CENTRAL MTNS OVER NEXT COUPLE OF HOURS...WITH FAIRLY SHORT-LIVED MVFR FOG RESTRICTIONS POSS OVER THE SE. CONDITIONS IMPROVE TO VFR DURING THE MID/LATE MORNING HOURS. ISOLATED TSTMS POSS ACROSS SOUTHERN TIER. OUTLOOK... FRI...BCMG VFR. ISO TSTMS POSS SOUTH. SAT-SUN...CIG REDUCTIONS LIKELY WITH PERIODS OF SHRA/TSRA. LOCALLY +RA PSBL SAT NGT INTO EARLY SUNDAY. MON...MAINLY VFR. MVFR WEST WITH ISOLATED TSRA. TUE...MAINLY VFR. CHANCE TSRA. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...GRUMM NEAR TERM...ROSS SHORT TERM...DEVOIR LONG TERM...GRUMM AVIATION...ROSS
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1025 AM EDT FRI JUN 19 2015 .SYNOPSIS... AN UNSETTLED PATTERN WILL PERSIST THROUGH THE WEEKEND AND EARLY NEXT WEEK AS ZONAL FLOW PERSISTS ACROSS THE LOWER 48 STATES. FREQUENT UPPER LEVEL TROUGHS AND NORTHWARD AND SOUTHWARD OSCILLATIONS OF A TROPICAL MOISTURE BOUNDARY WILL LEAD TO PERIODS OF SHOWERS AND THUNDERSTORMS THROUGHOUT THIS TIME. A DRIER PATTERN MAY EMERGE BY THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... FRONTAL BOUNDARY SAGGING SOUTH ACROSS CWA THIS MORNING. THE MAJORITY OF THE CWA WILL BE DRY TODAY, WITH JUST A FEW LIGHT SHOWERS DRIFTING SOUTH WITH FRONTAL BOUNDARY AND ANOTHER AREA OF SHOWERS MOVING INTO SW PA THIS AFTERNOON...THE FIRST BATCH OF MOISTURE FROM REMNANTS OF BILL. HRRR SHOWS THESE SHOWERS WILL SLIDE ALONG OR SOUTH OF PA/MD BORDER. SATELLITE SHOWS SOME BREAKS IN CLOUDS BUT EXPECT THAT TO FILL IN AND SUNSHINE WILL BE LIMITED ACROSS THE CWA TODAY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... DEWPOINTS SLOWLY DECREASE THIS AFTERNOON AND TONIGHT PROVIDING A MORE COMFORTABLE SLEEPING NIGHT FOR MUCH OF CENTRAL AND NORTH CENTRAL PA. DEWPOINTS ACROSS THE SOUTH WILL REMAIN IN THE LOWER 60S OVERNIGHT. PROXIMITY TO STALLED BOUNDARY ALSO MEANS PRECIP CHANCE CANNOT BE RULED OUT ACROSS THE SOUTHERN THIRD OF CENTRAL PA OVERNIGHT.KEPT SLIGHT CHANCES GOING OVER THE LAUREL HIGHLANDS EXTENDING INTO THE SOUTH CENTRAL MOUNTAINS OVERNIGHT. CENTRAL AND NORTHERN AREAS WILL REMAIN DRY. MINS WILL DROP TO AROUND 50F NORTH TO AROUND 60F SOUTH. MOISTURE GRADUALLY INCREASES AGAIN ON SATURDAY AS QUASI STATIONARY BOUNDARY WAGGLES BACK NORTHWARD. THE DEEPEST MOISTURE ASSOCIATED WITH THE TROPICAL MOISTURE REMNANTS FROM BILL ARE PROGGED TO MOVED THROUGH THE LOWER OHIO VALLEY AND MAINLY SOUTH OF THE MASON DIXON LINE ON SATURDAY. HOWEVER...PRECIPITABLE H20 VALUES 1.5" TO 2.0" ARE EXPECTED BY SATURDAY AFTERNOON...ALONG WITH INCREASING BOUNDARY LAYER CONVERGENCE AND MODERATE CAPES...FUELING SCT TO NMRS SHRA AND TSRA AND SOME LOCALLY HEAVY DOWNPOURS. HIGHS WILL RANGE FROM THE MID 70S NORTH TO AROUND 80 SOUTH. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... RAINFALL FROM THE TROPICAL MOISTURE REMNANTS OF BILL MAY BRING A WIDESPREAD ONE TO TWO INCHES OF RAIN ACROSS THE SOUTHERN HALF OF THE STATE SATURDAY AFTERNOON AND NIGHT...WITH LESS TO THE NORTH OF STATE COLLEGE. HEAVY DOWNPOURS WITH ANY THUNDERSTORMS COULD PRODUCE LOCALLY HIGHER AMOUNTS AND SO THIS IS STILL A CONCERN SATURDAY NIGHT AND SUNDAY. HOWEVER...MOST OF THE RAINFALL WILL BE BENEFICIAL FOR DROUGHT RELIEF. THE MAIN CONCERN REMAINS FOR POTENTIAL OF LOCALIZED FLOODING IF THUNDERSTORMS REPEATEDLY MOVE OVER THE SAME LOCATIONS. CLOUDS AND HUMIDITY WILL LINGER BEHIND UNTIL THE COLD FRONT SWEEPS THROUGH SUNDAY NIGHT. THE FRONT MAY TRIGGER ADDITIONAL SHOWERS AND THUNDERSTORMS SUNDAY AFTERNOON AND NIGHT. UPR LEVEL RIDGE SETS UP OVER THE CENTRAL U.S. WITH NW FLOW ACROSS PA BEGINNING MONDAY INTO TUESDAY. MODEL UNCERTAINTY INCREASES FOR MID WEEK ON TIMING AND STRENGTH OF THE NEXT SYSTEMS. GENERALLY LOOKING AT A VIGOROUS LOW PRESSURE CENTER MOVES FROM THE GREAT LAKES INTO PA MONDAY NIGHT INTO TUESDAY MORNING SPREADING MORE SHOWERS ACROSS THE STATE. AN ASSOCIATED COLD FRONT SWEEPS THROUGH WITH WEATHER CLEARING BY TUESDAY NIGHT. HIGH PRESSURE BUILDS IN FOR WEDNESDAY BRINGING COOLER NIGHTS AND DRIER WEATHER. BUT THE ACTIVE PATTERN CONTINUES WITH THE NEXT WAVE APPROACHING SW PA WITH A WARM FRONT AND SHOWERS POSSIBLE AGAIN ON THURSDAY. && .AVIATION /14Z FRIDAY THROUGH TUESDAY/... BROAD UPPER TROF AND 40KT 850 MB JET DRIVING AREA OF RAIN AND SCT CONVECTION TO CENTRAL PA EARLY THIS MORNING. OVERALL AREA IS SLOWLY DIMINISHING...BUT SCT SHRA/TSTMS WILL REMAIN POSS WITH ACTIVITY SHIFTING TO THE NORTHERN MTNS THROUGH THE OVERNIGHT. MVFR/IFR CIGS SHOULD SETTLE IN OVER NORTHERN AND CENTRAL MTNS OVER NEXT COUPLE OF HOURS...WITH FAIRLY SHORT-LIVED MVFR FOG RESTRICTIONS POSS OVER THE SE. CONDITIONS IMPROVE TO VFR DURING THE MID/LATE MORNING HOURS. ISOLATED TSTMS POSS ACROSS SOUTHERN TIER. OUTLOOK... FRI...BCMG VFR. ISO TSTMS POSS SOUTH. SAT-SUN...CIG REDUCTIONS LIKELY WITH PERIODS OF SHRA/TSRA. LOCALLY +RA PSBL SAT NGT INTO EARLY SUNDAY. MON...MAINLY VFR. MVFR WEST WITH ISOLATED TSRA. TUE...MAINLY VFR. CHANCE TSRA. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DEVOIR NEAR TERM...ROSS SHORT TERM...DEVOIR LONG TERM...WATSON AVIATION...RXR
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1038 PM EDT SAT JUN 20 2015 .SYNOPSIS... HIGH PRESSURE WILL STEADILY BUILD BACK INTO THE AREA FROM SUNDAY THROUGH THE MIDDLE OF NEXT WEEK...WITH HOT TEMPERATURES RETURNING AS A STALLED FRONT REMAINS NORTH OF THE REGION. BY THE END OF THE WORK WEEK THE HOT PATTERN IS EXPECTED TO BREAK DOWN AS A TROUGH MOVES SOUTHWARD OUT OF CANADA. && .NEAR TERM /THROUGH SUNDAY/... ZCZC GSPWRKNRT 000 TTAA00 KCAE 202323 0200 UTC UPDATE...A LINE OF SHOWERS NORTH OF KCLT POPPED-UP IN THE LAST HOUR...BUT QUICKLY DISPERSED...LEAVING THE CWA NEARLY SHOWER- FREE. REMNANTS OF THESE SHOWERS...THEMSELVES RELATED TO THE OUTER RAIN BANDS OF THE REMNANTS OF TS BILL...ARE FORECAST TO GRADUALLY PROGRESS SOUTH EASTWARD BEFORE COMPLETELY DISSIPATING. REST OF UPDATES TO BLEND IN LATEST OBS FOR SKY AND TEMPERATURES. AS OF 720 PM...MOST SHOWERS AND ALL LIGHTNING HAS LEFT THE AREA WITH A FEW LIGHT SHOWERS REMAINING...MOSTLY OVER THE MOUNTAINS OF WESTERN NORTH CAROLINA. HRRR CONTINUES THE TREND OF DECLINING PRECIP SUNDAY MORNING. UPDATED FORECAST TO CLEAR MOST PRECIPITATION AND UPDATE WINDS AND TEMPERATURE TRENDS. FOR THE OVERNIGHT...THE SURFACE TROUGH ASSOCIATED WITH THE REMNANTS OF BILL WILL MOVE SOUTH OF THE AREA WITH WEAK HIGH PRESSURE BUILDING OVER THE AREA FROM THE WEST BY EARLY SUNDAY. LOOKS LIKE CONVECTIVE CHANCES ON SUNDAY WILL BE LIMITED BY OVERALL WEAK SUBSIDENCE AND LOW LEVEL CIN TO OVERCOME. HENCE...POPS WILL BE LIMITED TO ISOLATED IN NATURE OVER THE HIGH TERRAIN WHERE CIN MAY BE OVERCOME WITH AFTERNOON HEATING. WITH DOWNSLOPE FLOW...TEMPS SHOULD HAVE NO TROUBLE WARMING WELL INTO THE 90S EAST OF THE MOUNTAINS...WITH 80S MOUNTAIN VALLEYS. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/... AS OF 200 PM EDT SATURDAY...THE SHORT RANGE FCST PERIOD INITIALIZES SUNDAY EVENING AMIDST BUILDING HEIGHTS ALOFT OVER THE DEEP SOUTH THANKS TO STRENGTHENING UPPER ANTICYCLONE. THE SURFACE PATTERN FEATURES AN ELONGATED/CLOSED LOW PRESSURE SYSTEM SLIDING ACROSS THE NORTHEAST CONUS...WHILE A TRAILING COLD FRONT STRETCHES ALONG THE OHIO VALLEY REGION NORTHWARD. CLOSER TO HOME...A TROF IN PLACE ACROSS THE ATLANTIC SEABOARD WILL WEAKEN INTO THE EVENING AS THE PARENT LOW PRESSURE SYSTEM MOVES AWAY. GUIDANCE SUGGESTS THAT THE AFORE MENTIONED FRONT COULD STALL JUST NORTH OF THE FORECAST AREA SUNDAY NIGHT...WITH THE NAM ACTUALLY PROVIDING HINTS OF AN ONGOING FRONTAL MCS MAKING A RUN AT THE NC MOUNTAINS. WITH UPPER HEIGHTS BEING LOWEST AND ABUNDANT INSTABILITY BEING PRESENT ACROSS THESE ZONES...CANNOT RULE OUT SUCH. EXPECTING ANY OF THIS ACTIVITY TO STRUGGLE AS IT SLIDES DEEPER INTO THE SUBSIDENCE LAYER BY EARLY MORNING MONDAY...IF IT SURVIVES A TRIP ACROSS THE MTNS IN THE FIRST PLACE. POPS WILL INITIALIZE AT SLIGHT CHANCE LEVELS OVER THE BLUE RIDGE BEFORE TAPERING INTO THE OVERNIGHT/MORNING. FROM THAT POINT ON GUIDANCE FAVORS INCREASED DEEP LAYER RIDGING THROUGH MIDWEEK WITH ANY SHRA/TSRA ACTIVITY BEING DIURNAL IN NATURE. OVERALL THE BEST PRECIPITATION CHANCES WILL BE ON MONDAY AFTERNOON WHERE SLIGHT/CHANCE MTN AND FOOTHILL POPS ARE FAVORED. SOUNDINGS ON TUESDAY GIVE MUCH SUPPORT TO THE RIDGE WITH MOST OF THE AREA STRUGGLING TO BREAK ANY CAPPING THAT IS IN PLACE...THUS TUESDAYS POPS FEATURE SLIGHT CHANCES OVER THE SW MTNS. WEAK FLOW ALOFT WILL LIMIT SHEAR THUS EXPECTING ANY CONVECTION EITHER DAY TO BE PULSE IN NATURE. TEMPERATURES THROUGH THE SHORT TERM PERIOD WILL ALSO BE OF NOTE AS ZONAL FLOW OVER THE NORTH COMBINES WITH THE AFORE MENTIONED UPPER RIDGE OVER THE SOUTH TO YIELD INCREASINGLY HOT/HUMID DAYS. HIGHS BOTH MONDAY AND TUESDAY ARE EXPECTED TO BE WELL ABOVE NORMAL WITH THE PIEDMONT APPROACHING/EXCEEDING THE CENTURY MARK...POTENTIALLY BREAKING RECORDS. EXPECTING HEAT INDEX VALUES TO APPROACH DANGEROUS LEVELS WITH HEAT ADVISORIES BEING A POSSIBILITY EACH DAY. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 200 PM SAT...THE FLAT BUT STILL HOT UPPER RIDGE WILL REMAIN OVER THE SOUTHERN STATES THRU MIDWEEK...WHILE FASTER FLOW CONTINUES OVER THE RIDGE ACRS THE NERN CONUS. CONSENSUS OF THE LONG RANGE MODELS IS THAT AS A SHORTWAVE EMBEDDED IN THAT FLOW WILL LAY OUT A COLD FRONT ACRS THE OHIO VALLEY...WHICH STALLS TO OUR NORTH WED AS THE WAVE PULLS AWAY. LATEST AVBL DETERMINISTIC AND ENSEMBLE GUIDANCE HOWEVER DOES SHOW HEIGHTS BEGINNING TO FALL OVER OUR AREA THU AS A SHORTWAVE MOVES FROM THE CANADIAN PRAIRIE INTO THE GREAT LAKES REGION. THE PATTERN SUBSEQUENTLY BECOMES MORE AMPLIFIED...AND THAT FRONT IS EXPECTED TO FINALLY ARRIVE THU NIGHT. SOLUTIONS DIVERGE THEREAFTER BUT THERE ARE INDICATIONS WE WILL SEE ACTIVE WX GOING INTO NEXT WEEKEND AS A PRONOUNCED TROUGH DIGS INTO THE MISSISSIPPI VALLEY AND INTERACTS WITH THE EXISTING BOUNDARY. WE WILL CONTINUE TO FCST NEAR-RECORD MAXES WED AND THU...THOUGH THE FAVORED BLEND HAS TRENDED SLIGHTLY COOLER FROM THE LAST CYCLE...SO A HWO MENTION STILL IS UNWARRANTED. TEMPS WILL COOL A BIT FOR FRIDAY...BUT NOT RETURNING TO NEAR NORMAL UNTIL SATURDAY. CONVECTION IS POSSIBLE EACH DAY OF THE PERIOD. GFS PROFILES HAD PREVIOUSLY INDICATED POOR MIDLEVEL TEMPS WITHIN THE RIDGE WOULD KEEP MUCH OF THE PIEDMONT CAPPED WED AND THU AFTNS...BUT THE LATEST RUN SEEMS TO REFLECT A WEAKER RIDGE AND SUGGESTS FREE CONVECTION THERE. WEAK SHEAR PROFILES AND MODEST INSTABILITY MEAN PULSE STORMS WILL PROBABLY BE OF SOME CONCERN ON THESE DAYS. WEAK DOWNSLOPING WILL LIKELY LIMIT THE COVERAGE HOWEVER. TO SUMMARIZE...ON WED-THU POPS PEAK AT A HIGH CHC MTNS AND SCHC TO LOW CHC PIEDMONT. THE FRONT WARRANTS POPS PERSISTING OVERNIGHT THU NIGHT WITH MOST OF THE CWFA SOLIDLY IN CHC RANGE THRU EARLY SUNDAY ON ACCOUNT OF THE AFOREMENTIONED SYNOPTIC FEATURES. SHEAR PARAMETERS WAX LATE IN THE PERIOD BUT ARE NOT CURRENTLY INDICATIVE OF A SIGNIFICANT SEVERE THREAT. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/... ZCZC GSPWRKTAF 201802 TTAA00 KGSP DDHHMM AT KCLT...CONVECTIVE ACTIVITY HAS ENDED FOR THE EVENING WITH REDUCED CHANCES FOR SHOWER ACTIVITY FOR THE NEXT 24 HOURS DUE TO THE MOVEMENT OF THE REMNANTS OF TROPICAL STORM BILL MOVING RAPIDLY EASTWARD. ELSEWHERE...ONLY A FEW LIGHT SHOWERS REMAIN OVER THE APPALACHIANS IN NORTH CAROLINA...AND THESE ARE EXPECTED TO CONTINUE TO DECLINE WITH THE HRRR HAVING NO ACTIVITY AFTER 3Z. FOG REMAINS IN THE FORECAST FOR AVL AND HKY DUE TO MOIST BOUNDARY LAYER AND CLIMATIC TREND. THUNDER SHOWER ACTIVITY IS AGAIN POSSIBLE ON SUNDAY...BUT PRIMARILY OVER AND JUST DOWN WIND OF THE HIGHER TERRAIN OF WESTERN NORTH CAROLINA. OUTLOOK...PRECIPITATION CHANCES WILL BE DIURNAL AS ANOTHER SUBTROPICAL RIDGE SETS UP LATE IN THE WEEKEND INTO THE NEW WORK WEEK. AS A RESULT...THE GREATEST CHANCES FOR AFTERNOON SHRA/TSRA WILL BE ACROSS WESTERN NC WHERE THE LEAST SUBSIDENCE WILL RESIDE. MORNING RESTRICTIONS DUE TO FOG AND/OR STRATUS ARE POSSIBLE... PARTICULARLY WHERE HEAVY RAIN FELL THE PREVIOUS DAY...AND IN MTN VALLEYS. CONFIDENCE TABLE... 02-08Z 08-14Z 14-20Z 20-00Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 83% HIGH 100% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .CLIMATE... RECORD MAXIMUM TEMPERATURES FOR NEXT WEEK...WITH YEARS IN WHICH THE VALUES WERE LAST REACHED. MONDAY JUNE 22... AVL 94 1964 CLT 98 1956 GSP 99 2006 TUESDAY JUNE 23... AVL 93 1988 CLT 98 1988 GSP 99 1988 WEDNESDAY JUNE 24... AVL 94 1952 CLT 102 1930 GSP 100 1952 THURSDAY JUNE 25... AVL 96 1952 CLT 102 1914 GSP 101 1952 && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...WIMBERLEY NEAR TERM...LG/WJM SHORT TERM...CDG LONG TERM...WIMBERLEY AVIATION...WJM CLIMATE...
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
750 PM EDT SAT JUN 20 2015 .SYNOPSIS... HIGH PRESSURE WILL STEADILY BUILD BACK INTO THE AREA FROM SUNDAY THROUGH THE MIDDLE OF NEXT WEEK...WITH HOT TEMPERATURES RETURNING AS A STALLED FRONT REMAINS NORTH OF THE REGION. BY THE END OF THE WORK WEEK THE HOT PATTERN IS EXPECTED TO BREAK DOWN AS A TROUGH MOVES SOUTHWARD OUT OF CANADA. && .NEAR TERM /THROUGH SUNDAY/... AS OF 720 PM...MOST SHOWERS AND ALL LIGHTNING HAS LEFT THE AREA WITH A FEW LIGHT SHOWERS REMAINING...MOSTLY OVER THE MOUNTAINS OF WESTERN NORTH CAROLINA. HRRR CONTINUES THE TREND OF DECLINING PRECIP SUNDAY MORNING. UPDATED FORECAST TO CLEAR MOST PRECIPITATION AND UPDATE WINDS AND TEMPERATURE TRENDS. 2000 UTC UPDATE...ADJUSTED POPS/SKY/WINDS AND TEMPS FOR LATEST OBSERVATIONS. BANDS OF PRECIPITATION ROTATING AROUND THE REMNANTS OF TS BILL FAR TO THE NORTH ARE CURRENTLY AFFECTING PRIMARILY THE EASTERN AND SOUTHERN PORTIONS OF THE CWA...WITH MORE SHOWERS POSSIBLE LATER ELSEWHERE. AS OF 215 PM...AS THE UPPER TROUGH ASSOCIATED WITH THE REMNANTS OF TS BILL MOVE BY TO THE NORTH...ENOUGH FORCING WILL SWEEP ACROSS THE SOUTHERN APPALACHIANS AND WESTERN CAROLINAS TO GENERATE CONSIDERABLE CONVECTION THIS AFTERNOON. CURRENT RADAR SHOWS ACTIVITY DEVELOPING IN BANDS...ONE TO THE WEST OF CLT AND THE OTHER FROM THE NC MOUNTAINS...SW THROUGH WESTERN SC INTO GA. THESE FEATURES SHOULD MOVE EASTWARD DURING THE REMAINDER OF THE AFTERNOON AND AFFECT MOST AREAS. HENCE...POPS HAVE BEEN RAISED INTO THE LIKELY CATEGORY MOST AREAS. THE ATMOSPHERE HAS DESTABILIZED CONSIDERABLE ESPECIALLY OUTSIDE THE MOUNTAINS WHERE SBCAPES IN THE 2000-3000J EXIST. HOWEVER...THE AXIS OF BEST DCAPE CONTINUES TO SHIFT EASTWARD TO THE COAST. SHEAR IS INCREASING BUT THE 25KT OR BETTER BULK SHEAR REMAINS OVER THE MOUNTAINS WHERE LOWER INSTABILITY EXISTS. HOWEVER WITH THE HIGH CAPES...CAN`T RULE OUT A FEW SEVERE STORMS. FOR THE OVERNIGHT...THE SURFACE TROUGH ASSOCIATED WITH THE REMNANTS OF BILL WILL MOVE SOUTH OF THE AREA WITH WEAK HIGH PRESSURE BUILDING OVER THE AREA FROM THE WEST BY EARLY SUNDAY. LOOKS LIKE CONVECTIVE CHANCES ON SUNDAY WILL BE LIMITED BY OVERALL WEAK SUBSIDENCE AND LOW LEVEL CIN TO OVERCOME. HENCE...POPS WILL LIMITED TO ISOLATED IN NATURE OVER THE HIGH TERRAIN WHERE CIN MAY BE OVERCOME WITH AFTERNOON HEATING. WITH DOWNSLOPE FLOW...TEMPS SHOULD HAVE NO TROUBLE WARMING WELL INTO THE 90S EAST OF THE MOUNTAINS...WITH 80S MOUNTAIN VALLEYS. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/... AS OF 200 PM EDT SATURDAY...THE SHORT RANGE FCST PERIOD INITIALIZES SUNDAY EVENING AMIDST BUILDING HEIGHTS ALOFT OVER THE DEEP SOUTH THANKS TO STRENGTHENING UPPER ANTICYCLONE. THE SURFACE PATTERN FEATURES AN ELONGATED/CLOSED LOW PRESSURE SYSTEM SLIDING ACROSS THE NORTHEAST CONUS...WHILE A TRAILING COLD FRONT STRETCHES ALONG THE OHIO VALLEY REGION NORTHWARD. CLOSER TO HOME...A TROF IN PLACE ACROSS THE ATLANTIC SEABOARD WILL WEAKEN INTO THE EVENING AS THE PARENT LOW PRESSURE SYSTEM MOVES AWAY. GUIDANCE SUGGESTS THAT THE AFORE MENTIONED FRONT COULD STALL JUST NORTH OF THE FORECAST AREA SUNDAY NIGHT...WITH THE NAM ACTUALLY PROVIDING HINTS OF AN ONGOING FRONTAL MCS MAKING A RUN AT THE NC MOUNTAINS. WITH UPPER HEIGHTS BEING LOWEST AND ABUNDANT INSTABILITY BEING PRESENT ACROSS THESE ZONES...CANNOT RULE OUT SUCH. EXPECTING ANY OF THIS ACTIVITY TO STRUGGLE AS IT SLIDES DEEPER INTO THE SUBSIDENCE LAYER BY EARLY MORNING MONDAY...IF IT SURVIVES A TRIP ACROSS THE MTNS IN THE FIRST PLACE. POPS WILL INITIALIZE AT SLIGHT CHANCE LEVELS OVER THE BLUE RIDGE BEFORE TAPERING INTO THE OVERNIGHT/MORNING. FROM THAT POINT ON GUIDANCE FAVORS INCREASED DEEP LAYER RIDGING THROUGH MIDWEEK WITH ANY SHRA/TSRA ACTIVITY BEING DIURNAL IN NATURE. OVERALL THE BEST PRECIPITATION CHANCES WILL BE ON MONDAY AFTERNOON WHERE SLIGHT/CHANCE MTN AND FOOTHILL POPS ARE FAVORED. SOUNDINGS ON TUESDAY GIVE MUCH SUPPORT TO THE RIDGE WITH MOST OF THE AREA STRUGGLING TO BREAK ANY CAPPING THAT IS IN PLACE...THUS TUESDAYS POPS FEATURE SLIGHT CHANCES OVER THE SW MTNS. WEAK FLOW ALOFT WILL LIMIT SHEAR THUS EXPECTING ANY CONVECTION EITHER DAY TO BE PULSE IN NATURE. TEMPERATURES THROUGH THE SHORT TERM PERIOD WILL ALSO BE OF NOTE AS ZONAL FLOW OVER THE NORTH COMBINES WITH THE AFORE MENTIONED UPPER RIDGE OVER THE SOUTH TO YIELD INCREASINGLY HOT/HUMID DAYS. HIGHS BOTH MONDAY AND TUESDAY ARE EXPECTED TO BE WELL ABOVE NORMAL WITH THE PIEDMONT APPROACHING/EXCEEDING THE CENTURY MARK...POTENTIALLY BREAKING RECORDS. EXPECTING HEAT INDEX VALUES TO APPROACH DANGEROUS LEVELS WITH HEAT ADVISORIES BEING A POSSIBILITY EACH DAY. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 200 PM SAT...THE FLAT BUT STILL HOT UPPER RIDGE WILL REMAIN OVER THE SOUTHERN STATES THRU MIDWEEK...WHILE FASTER FLOW CONTINUES OVER THE RIDGE ACRS THE NERN CONUS. CONSENSUS OF THE LONG RANGE MODELS IS THAT AS A SHORTWAVE EMBEDDED IN THAT FLOW WILL LAY OUT A COLD FRONT ACRS THE OHIO VALLEY...WHICH STALLS TO OUR NORTH WED AS THE WAVE PULLS AWAY. LATEST AVBL DETERMINISTIC AND ENSEMBLE GUIDANCE HOWEVER DOES SHOW HEIGHTS BEGINNING TO FALL OVER OUR AREA THU AS A SHORTWAVE MOVES FROM THE CANADIAN PRAIRIE INTO THE GREAT LAKES REGION. THE PATTERN SUBSEQUENTLY BECOMES MORE AMPLIFIED...AND THAT FRONT IS EXPECTED TO FINALLY ARRIVE THU NIGHT. SOLUTIONS DIVERGE THEREAFTER BUT THERE ARE INDICATIONS WE WILL SEE ACTIVE WX GOING INTO NEXT WEEKEND AS A PRONOUNCED TROUGH DIGS INTO THE MISSISSIPPI VALLEY AND INTERACTS WITH THE EXISTING BOUNDARY. WE WILL CONTINUE TO FCST NEAR-RECORD MAXES WED AND THU...THOUGH THE FAVORED BLEND HAS TRENDED SLIGHTLY COOLER FROM THE LAST CYCLE...SO A HWO MENTION STILL IS UNWARRANTED. TEMPS WILL COOL A BIT FOR FRIDAY...BUT NOT RETURNING TO NEAR NORMAL UNTIL SATURDAY. CONVECTION IS POSSIBLE EACH DAY OF THE PERIOD. GFS PROFILES HAD PREVIOUSLY INDICATED POOR MIDLEVEL TEMPS WITHIN THE RIDGE WOULD KEEP MUCH OF THE PIEDMONT CAPPED WED AND THU AFTNS...BUT THE LATEST RUN SEEMS TO REFLECT A WEAKER RIDGE AND SUGGESTS FREE CONVECTION THERE. WEAK SHEAR PROFILES AND MODEST INSTABILITY MEAN PULSE STORMS WILL PROBABLY BE OF SOME CONCERN ON THESE DAYS. WEAK DOWNSLOPING WILL LIKELY LIMIT THE COVERAGE HOWEVER. TO SUMMARIZE...ON WED-THU POPS PEAK AT A HIGH CHC MTNS AND SCHC TO LOW CHC PIEDMONT. THE FRONT WARRANTS POPS PERSISTING OVERNIGHT THU NIGHT WITH MOST OF THE CWFA SOLIDLY IN CHC RANGE THRU EARLY SUNDAY ON ACCOUNT OF THE AFOREMENTIONED SYNOPTIC FEATURES. SHEAR PARAMETERS WAX LATE IN THE PERIOD BUT ARE NOT CURRENTLY INDICATIVE OF A SIGNIFICANT SEVERE THREAT. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... AT KCLT...CONVECTIVE ACTIVITY HAS ENDED FOR THE EVENING WITH REDUCED CHANCES FOR SHOWER ACTIVITY FOR THE NEXT 24 HOURS DUE TO THE MOVEMENT OF THE REMNANTS OF TROPICAL STORM BILL MOVING RAPIDLY EASTWARD. ELSEWHERE...ONLY A FEW LIGHT SHOWERS REMAIN OVER THE APPALACHIANS IN NORTH CAROLINA...AND THESE ARE EXPECTED TO CONTINUE TO DECLINE WITH THE HRRR HAVING NO ACTIVITY AFTER 3Z. FOG REMAINS IN THE FORECAST FOR AVL AND HKY DUE TO MOIST BOUNDARY LAYER AND CLIMATIC TREND. THUNDER SHOWER ACTIVITY IS AGAIN POSSIBLE ON SUNDAY...BUT PRIMARILY OVER AND JUST DOWN WIND OF THE HIGHER TERRAIN OF WESTERN NORTH CAROLINA. OUTLOOK...PRECIPITATION CHANCES WILL BE DIURNAL AS ANOTHER SUBTROPICAL RIDGE SETS UP LATE IN THE WEEKEND INTO THE NEW WORK WEEK. AS A RESULT...THE GREATEST CHANCES FOR AFTERNOON SHRA/TSRA WILL BE ACROSS WESTERN NC WHERE THE LEAST SUBSIDENCE WILL RESIDE. MORNING RESTRICTIONS DUE TO FOG AND/OR STRATUS ARE POSSIBLE... PARTICULARLY WHERE HEAVY RAIN FELL THE PREVIOUS DAY...AND IN MTN VALLEYS. CONFIDENCE TABLE... 23-05Z 05-11Z 11-17Z 17-18Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .CLIMATE... RECORD MAXIMUM TEMPERATURES FOR NEXT WEEK...WITH YEARS IN WHICH THE VALUES WERE LAST REACHED. MONDAY JUNE 22... AVL 94 1964 CLT 98 1956 GSP 99 2006 TUESDAY JUNE 23... AVL 93 1988 CLT 98 1988 GSP 99 1988 WEDNESDAY JUNE 24... AVL 94 1952 CLT 102 1930 GSP 100 1952 THURSDAY JUNE 25... AVL 96 1952 CLT 102 1914 GSP 101 1952 && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...WIMBERLEY NEAR TERM...LG/WJM SHORT TERM...CDG LONG TERM...WIMBERLEY AVIATION...WJM CLIMATE...
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
725 PM EDT SAT JUN 20 2015 .SYNOPSIS... HIGH PRESSURE WILL STEADILY BUILD BACK INTO THE AREA FROM SUNDAY THROUGH THE MIDDLE OF NEXT WEEK...WITH HOT TEMPERATURES RETURNING AS A STALLED FRONT REMAINS NORTH OF THE REGION. BY THE END OF THE WORK WEEK THE HOT PATTERN IS EXPECTED TO BREAK DOWN AS A TROUGH MOVES SOUTHWARD OUT OF CANADA. && .NEAR TERM /THROUGH SUNDAY/... AS OF 720 PM...MOST SHOWERS AND ALL LIGHTNING HAS LEFT THE AREA WITH A FEW LIGHT SHOWERS REMAINING...MOSTLY OVER THE MOUNTAINS OF WESTERN NORTH CAROLINA. HRRR CONTINUES THE TREND OF DECLINING PRECIP SUNDAY MORNING. UPDATED FORECAST TO CLEAR MOST PRECIPITATION AND UPDATE WINDS AND TEMPERATURE TRENDS. 2000 UTC UPDATE...ADJUSTED POPS/SKY/WINDS AND TEMPS FOR LATEST OBSERVATIONS. BANDS OF PRECIPITATION ROTATING AROUND THE REMNANTS OF TS BILL FAR TO THE NORTH ARE CURRENTLY AFFECTING PRIMARILY THE EASTERN AND SOUTHERN PORTIONS OF THE CWA...WITH MORE SHOWERS POSSIBLE LATER ELSEWHERE. AS OF 215 PM...AS THE UPPER TROUGH ASSOCIATED WITH THE REMNANTS OF TS BILL MOVE BY TO THE NORTH...ENOUGH FORCING WILL SWEEP ACROSS THE SOUTHERN APPALACHIANS AND WESTERN CAROLINAS TO GENERATE CONSIDERABLE CONVECTION THIS AFTERNOON. CURRENT RADAR SHOWS ACTIVITY DEVELOPING IN BANDS...ONE TO THE WEST OF CLT AND THE OTHER FROM THE NC MOUNTAINS...SW THROUGH WESTERN SC INTO GA. THESE FEATURES SHOULD MOVE EASTWARD DURING THE REMAINDER OF THE AFTERNOON AND AFFECT MOST AREAS. HENCE...POPS HAVE BEEN RAISED INTO THE LIKELY CATEGORY MOST AREAS. THE ATMOSPHERE HAS DESTABILIZED CONSIDERABLE ESPECIALLY OUTSIDE THE MOUNTAINS WHERE SBCAPES IN THE 2000-3000J EXIST. HOWEVER...THE AXIS OF BEST DCAPE CONTINUES TO SHIFT EASTWARD TO THE COAST. SHEAR IS INCREASING BUT THE 25KT OR BETTER BULK SHEAR REMAINS OVER THE MOUNTAINS WHERE LOWER INSTABILITY EXISTS. HOWEVER WITH THE HIGH CAPES...CAN`T RULE OUT A FEW SEVERE STORMS. FOR THE OVERNIGHT...THE SURFACE TROUGH ASSOCIATED WITH THE REMNANTS OF BILL WILL MOVE SOUTH OF THE AREA WITH WEAK HIGH PRESSURE BUILDING OVER THE AREA FROM THE WEST BY EARLY SUNDAY. LOOKS LIKE CONVECTIVE CHANCES ON SUNDAY WILL BE LIMITED BY OVERALL WEAK SUBSIDENCE AND LOW LEVEL CIN TO OVERCOME. HENCE...POPS WILL LIMITED TO ISOLATED IN NATURE OVER THE HIGH TERRAIN WHERE CIN MAY BE OVERCOME WITH AFTERNOON HEATING. WITH DOWNSLOPE FLOW...TEMPS SHOULD HAVE NO TROUBLE WARMING WELL INTO THE 90S EAST OF THE MOUNTAINS...WITH 80S MOUNTAIN VALLEYS. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/... AS OF 200 PM EDT SATURDAY...THE SHORT RANGE FCST PERIOD INITIALIZES SUNDAY EVENING AMIDST BUILDING HEIGHTS ALOFT OVER THE DEEP SOUTH THANKS TO STRENGTHENING UPPER ANTICYCLONE. THE SURFACE PATTERN FEATURES AN ELONGATED/CLOSED LOW PRESSURE SYSTEM SLIDING ACROSS THE NORTHEAST CONUS...WHILE A TRAILING COLD FRONT STRETCHES ALONG THE OHIO VALLEY REGION NORTHWARD. CLOSER TO HOME...A TROF IN PLACE ACROSS THE ATLANTIC SEABOARD WILL WEAKEN INTO THE EVENING AS THE PARENT LOW PRESSURE SYSTEM MOVES AWAY. GUIDANCE SUGGESTS THAT THE AFORE MENTIONED FRONT COULD STALL JUST NORTH OF THE FORECAST AREA SUNDAY NIGHT...WITH THE NAM ACTUALLY PROVIDING HINTS OF AN ONGOING FRONTAL MCS MAKING A RUN AT THE NC MOUNTAINS. WITH UPPER HEIGHTS BEING LOWEST AND ABUNDANT INSTABILITY BEING PRESENT ACROSS THESE ZONES...CANNOT RULE OUT SUCH. EXPECTING ANY OF THIS ACTIVITY TO STRUGGLE AS IT SLIDES DEEPER INTO THE SUBSIDENCE LAYER BY EARLY MORNING MONDAY...IF IT SURVIVES A TRIP ACROSS THE MTNS IN THE FIRST PLACE. POPS WILL INITIALIZE AT SLIGHT CHANCE LEVELS OVER THE BLUE RIDGE BEFORE TAPERING INTO THE OVERNIGHT/MORNING. FROM THAT POINT ON GUIDANCE FAVORS INCREASED DEEP LAYER RIDGING THROUGH MIDWEEK WITH ANY SHRA/TSRA ACTIVITY BEING DIURNAL IN NATURE. OVERALL THE BEST PRECIPITATION CHANCES WILL BE ON MONDAY AFTERNOON WHERE SLIGHT/CHANCE MTN AND FOOTHILL POPS ARE FAVORED. SOUNDINGS ON TUESDAY GIVE MUCH SUPPORT TO THE RIDGE WITH MOST OF THE AREA STRUGGLING TO BREAK ANY CAPPING THAT IS IN PLACE...THUS TUESDAYS POPS FEATURE SLIGHT CHANCES OVER THE SW MTNS. WEAK FLOW ALOFT WILL LIMIT SHEAR THUS EXPECTING ANY CONVECTION EITHER DAY TO BE PULSE IN NATURE. TEMPERATURES THROUGH THE SHORT TERM PERIOD WILL ALSO BE OF NOTE AS ZONAL FLOW OVER THE NORTH COMBINES WITH THE AFORE MENTIONED UPPER RIDGE OVER THE SOUTH TO YIELD INCREASINGLY HOT/HUMID DAYS. HIGHS BOTH MONDAY AND TUESDAY ARE EXPECTED TO BE WELL ABOVE NORMAL WITH THE PIEDMONT APPROACHING/EXCEEDING THE CENTURY MARK...POTENTIALLY BREAKING RECORDS. EXPECTING HEAT INDEX VALUES TO APPROACH DANGEROUS LEVELS WITH HEAT ADVISORIES BEING A POSSIBILITY EACH DAY. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 200 PM SAT...THE FLAT BUT STILL HOT UPPER RIDGE WILL REMAIN OVER THE SOUTHERN STATES THRU MIDWEEK...WHILE FASTER FLOW CONTINUES OVER THE RIDGE ACRS THE NERN CONUS. CONSENSUS OF THE LONG RANGE MODELS IS THAT AS A SHORTWAVE EMBEDDED IN THAT FLOW WILL LAY OUT A COLD FRONT ACRS THE OHIO VALLEY...WHICH STALLS TO OUR NORTH WED AS THE WAVE PULLS AWAY. LATEST AVBL DETERMINISTIC AND ENSEMBLE GUIDANCE HOWEVER DOES SHOW HEIGHTS BEGINNING TO FALL OVER OUR AREA THU AS A SHORTWAVE MOVES FROM THE CANADIAN PRAIRIE INTO THE GREAT LAKES REGION. THE PATTERN SUBSEQUENTLY BECOMES MORE AMPLIFIED...AND THAT FRONT IS EXPECTED TO FINALLY ARRIVE THU NIGHT. SOLUTIONS DIVERGE THEREAFTER BUT THERE ARE INDICATIONS WE WILL SEE ACTIVE WX GOING INTO NEXT WEEKEND AS A PRONOUNCED TROUGH DIGS INTO THE MISSISSIPPI VALLEY AND INTERACTS WITH THE EXISTING BOUNDARY. WE WILL CONTINUE TO FCST NEAR-RECORD MAXES WED AND THU...THOUGH THE FAVORED BLEND HAS TRENDED SLIGHTLY COOLER FROM THE LAST CYCLE...SO A HWO MENTION STILL IS UNWARRANTED. TEMPS WILL COOL A BIT FOR FRIDAY...BUT NOT RETURNING TO NEAR NORMAL UNTIL SATURDAY. CONVECTION IS POSSIBLE EACH DAY OF THE PERIOD. GFS PROFILES HAD PREVIOUSLY INDICATED POOR MIDLEVEL TEMPS WITHIN THE RIDGE WOULD KEEP MUCH OF THE PIEDMONT CAPPED WED AND THU AFTNS...BUT THE LATEST RUN SEEMS TO REFLECT A WEAKER RIDGE AND SUGGESTS FREE CONVECTION THERE. WEAK SHEAR PROFILES AND MODEST INSTABILITY MEAN PULSE STORMS WILL PROBABLY BE OF SOME CONCERN ON THESE DAYS. WEAK DOWNSLOPING WILL LIKELY LIMIT THE COVERAGE HOWEVER. TO SUMMARIZE...ON WED-THU POPS PEAK AT A HIGH CHC MTNS AND SCHC TO LOW CHC PIEDMONT. THE FRONT WARRANTS POPS PERSISTING OVERNIGHT THU NIGHT WITH MOST OF THE CWFA SOLIDLY IN CHC RANGE THRU EARLY SUNDAY ON ACCOUNT OF THE AFOREMENTIONED SYNOPTIC FEATURES. SHEAR PARAMETERS WAX LATE IN THE PERIOD BUT ARE NOT CURRENTLY INDICATIVE OF A SIGNIFICANT SEVERE THREAT. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... AT KCLT...MAIN CONCERN FOR THIS TAF CYCLE IS THE THUNDERSTORM POTENTIAL. A BAND OF TSRA IS BEGINNING TO DEVELOP JUST WEST OF THE AIRFILED WITH ANOTHER IN WESTERN SC INTO GA. THEREFORE...EXPECT THAT THE AIRFIELD MAY SEE A COUPLE ROUNDS OF TSRA IN THE 19Z-23Z TIMEFRAME. HENCE HAVE A TEMPO WITH RESTRICTIONS. CONVECTIVE THREAT SHOULD END AFTER 00Z AS A SFC TROUGH MOVES SE OF THE AREA. OTHERWISE...VFR CONDITIONS. ELSEWHERE...CONVECTION DEVELOPING IN BANDS ACROSS THE AREA ONE WEST OF CLT AND ANOTHER OVER WESTERN SC INTO GA. THESE FEATURES WILL MOVE EASTWARD. THEREFORE...EXPECT ALL AIRFIELDS WILL EXPERIENCE A TSRA PRIOR TO 00Z. WILL HAVE TEMPOS WITH RESTRICTIONS AT ALL TAF SITES. CONVECTIVE THREAT WILL END AFTER 00Z AS A SFC TROUGH MOVES SE OF THE AREA. AFTER 00Z EXPECT VFR GENERALLY CONDITIONS. THE EXCEPTION WILL BE THE POTENTIAL FOR FOG DEVLOPMENT AT AVL AND HKY EARLY SUNDAY. UTLOOK...PRECIPITATION CHANCES WILL BE DIURNAL AS ANOTHER SUBTROPICAL RIDGE SETS UP LATE IN THE WEEKEND INTO THE NEW WORK WEEK. AS A RESULT...THE GREATEST CHANCES FOR AFTERNOON SHRA/TSRA WILL BE ACROSS WESTERN NC WHERE THE LEAST SUBSIDENCE WILL RESIDE. MORNING RESTRICTIONS DUE TO FOG AND/OR STRATUS ARE POSSIBLE... PARTICULARLY WHERE HEAVY RAIN FELL THE PREVIOUS DAY...AND IN MTN VALLEYS. CONFIDENCE TABLE... 23-05Z 05-11Z 11-17Z 17-18Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .CLIMATE... RECORD MAXIMUM TEMPERATURES FOR NEXT WEEK...WITH YEARS IN WHICH THE VALUES WERE LAST REACHED. MONDAY JUNE 22... AVL 94 1964 CLT 98 1956 GSP 99 2006 TUESDAY JUNE 23... AVL 93 1988 CLT 98 1988 GSP 99 1988 WEDNESDAY JUNE 24... AVL 94 1952 CLT 102 1930 GSP 100 1952 THURSDAY JUNE 25... AVL 96 1952 CLT 102 1914 GSP 101 1952 && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...WIMBERLEY NEAR TERM...LG/WJM SHORT TERM...CDG LONG TERM...WIMBERLEY AVIATION...LG CLIMATE...
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
203 PM EDT SAT JUN 20 2015 .SYNOPSIS... THE REMNANT CIRCULATION OF TROPICAL SYSTEM BILL WILL MOVE UP THE OHIO VALLEY TODAY...CROSS THE APPALACHIANS TONIGHT...THEN MOVE OFF THE MID ATLANTIC COAST ON SUNDAY. DEEPER MOISTURE WITH THIS SYSTEM WILL BRUSH WESTERN NORTH CAROLINA MAINLY THIS EVENING. HIGH PRESSURE WILL STEADILY BUILD BACK INTO THE AREA BEHIND THE DEPARTING WAVE THROUGH THE MIDDLE OF NEXT WEEK...WITH HOT TEMPERATURES RETURNING AS A STATIONARY FRONT STAYS NORTH OF THE REGION. THE RIDGE OF HIGH PRESSURE WILL START TO BREAK DOWN TOWARD NEXT WEEKEND. && .NEAR TERM /THROUGH SUNDAY/... AT 1225 PM...RADAR SHOWS A BAND OF SHOWERS/TSRA FROM THE NORTHERN NC MOUNTAINS SW INTO NE GA. THIS BAND SHOULD MOVE EASTWARD THROUGHOUT THE AFTERNOON. SOME WIDELY SCT SHOWERS DEVELOPING IN UNSTABLE AIRMASS OVER THE PIEDMONT AS SBCAPES IN THE 2000J PLUS THERE. BUMPED POPS UPWARD ACROSS NE GA AND UPSTATE SC IN DEFERENCE TO CURRENT RADAR TRENDS. LATEST DCAPE FROM SPC MESO ANAL SHOWS THE AXIS OF 1000J PLUS NOW WELL EAST OF THE AREA WITH ABOUT 800J NEAR CLT. HENCE...GREATEST THREAT FOR SEVERE STILL SEEMS TO BE OVER EASTERN AREAS WITH THE BEST OVERLAP OF CAPE/DCAPE MAXES. AT 10 AM...REGIONAL RADARS SHOW AN AREA OF SHOWERS OVER FAR WESTERN NC WHICH WAS MOVING EAST. LATEST HRRR BRINGS ANOTHER BAND OF SHRA/TSRA INTO THE MOUNTAINS FROM TN CIRCA 18Z AND MOVES THIS EASTWARD THROUGH 00Z. THE HRRR ALSO GENERATES SOME WIDELY SCT TSRA OVER UPSTATE SC. 12Z NAM IS FAVORING WESTERN NC AS WELL WITH GREATEST QPF RESPONSE...SO WILL MAINTAIN LIKELY/CAT POPS THROUGH THE MOUNTAINS THIS AFTERNOON... TRENDING DOWNWARD TO WIDELY SCT TYPE POPS LOWER PIEDMONT. ADJUSTED MAX TEMPS UPWARD EASTERN AREAS WHERE THE MOST INSOLATION WILL OCCUR. CURRENT INDICATIONS ARE THAT PERHAPS THE GREATEST THREAT FOR SEVERE STORMS WILL BE OVER EASTERN AREAS WHERE CAPES IN EXCESS OF 2000J/KG WILL OVERLAP WITH DCAPES AROUND 1000J. 630 AM EDT UPDATE...NOT MUCH CHANGE IN THE GOING GRIDS WITH TEMPS AND TD/S REMAINING FAIRLY STEADY STEADY STATE. CLOUDS AND POPS WERE ADJ UP ACROSS THE SW NC MTNS WHERE THE FIRST WAVES OF MOISTURE ARE COMING IN FROM EXTROP STORM BILL AND PRODUCING MODERATE SHOWERS. THE REMNANTS OF TS BILL WILL MOVE NE ACROSS WRN KY TODAY WITH THE BEST DYNAMICAL QG FORCING MAINTAINED NW OF THE CWFA. THERE WILL BE SOME LOW END H7/H5 DCVA CROSSING THE WRN ZONES AS THE UPPER S/W TROF AXIS APPROACHES THE APPS. EVEN WITH THE UPPER RIDGE BREAKING DOWN THERE WILL MAINLY BE A SUPRESSIVE ATMOS IN PLACE ACROSS MOST OF THE FA DUE TO MLVL WAA AND MOISTURE ADV. DROPPED SOUNDINGS ACROSS THE WRN ZONES SHOW MLVL THETA/E INCREASING AND SATURATED PROFILES AFT 18Z ABOVE H7...WHILE THE SE/RN AREAS REMAIN RELATIVELY DRY ABOVE THE LFC. THUS...SBCAPE VALUES WILL VARY SIGFNTLY AND ACTUALLY DECREASE THROUGHOUT THE DAY ACROSS THE NC MTN AND FTHILL ZONES...WITH SOME MEASURE OF DECREASE OVER THE UPSTATE AND NE GA AS WELL. THE BEST CHANCE FOR DEEP CONVECTION THEREFORE WILL BE ACROSS THE I-77 CORRIDOOR AND ALONG AND NORTH OF THE I-40 CORRIDOOR. BULK SHEAR WILL INCREASE AS THE EXTROP SYSTEM NEARS AND THE BEST OVERLAP WITH INSTABILITY WILL GENRALLY BE OVER THE I-77 CORRIDOOR. DIFFERNTIAL HEATING ACROSS THE NC PIEDMONT AND ERN FTHILLS SHOULD ALLOW STRONG MULTICELL CLUSTER STORMS TO DEVELOP AS WELL WITH THE MAIN THREAT BEING DAMAGING STRAIGHT-LINE WINDS. HODOS REMAIN TOO STRAIGHT FOR MUCH OF A TOR THREAT...BUT AN ISOL WEAK TOR IS POSSIBLE GIVEN THE INCREASING SHEAR AND HORIZONTAL VORTICITY. LLVL LAPSE RATES AND DRY SUB CLOUD LAYER AIR OUTSIDE THE MTNS ALSO SUPPORT A WIND THREAT AND GUSTY CONDS WILL PREVAIL THROUGH THE AFTERNOON. TEMPERATURES WILL BE TRICKY DEPENDING ON THE AMOUNT OF MOIST ADV...BUT BELIEVE WITH THE LOWERING THICKNESSES MAXES WILL BE A CAT OR SO LOWER THAN FRI/S HIGHS OVER MOST LOCALES. LINGERING LOW TO MID LEVEL MOISTURE WILL TRAVERSE THE CWFA OVERNIGHT AS THE BASE OF THE TROF AXIS SLOWLY LIFTS NE. CHANCE POPS WILL BE LIMITED TO NC MTNS AND NRN FTHILLS IN MOIST WLY FLOW THROUGH 06Z OR SO AND DIMINISH THROUGH DAYBREAK WITH LOSS OF FORCING. MINS WILL BE A COUPLE DEGREES COOLER THAN THE LATEST TRENDS YET STILL A CAT ABOVE NORMAL. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/... AS OF 300 AM EDT SATURDAY...THE MID LEVEL TROUGH AND LOW LEVEL CIRCULATION ASSOCIATED WITH THE REMNANTS OF TROPICAL SYSTEM BILL WILL DEPART THE MID ATLANTIC COAST ON SUNDAY. EXPECT A WESTERLY DOWNSLOPING FLOW ACROSS THE REGION IN THE WAKE OF THE SYSTEM. THIS WILL LEAD TO SURFACE RIDGING OVER THE APPALACHIANS...WITH PIEDMONT TROUGHING SETTING UP SUNDAY THROUGH TUESDAY. LOW LEVELS WILL HEAT UP AGAIN VERY QUICKLY...WITH STEEP 850 TO 500 MB LAPSE RATES OF 7 TO 7.5 DEG C/KM EACH DAY GETTING ESTABLISHED. HOWEVER... MODEL PROFILES VARY WIDELY ON SB CAPE VALUES EACH AFTERNOON DUE TO VARIATIONS IN THE MID LEVEL TEMPS AND DEGREE OF CAPPING. WILL PLAN ON A LITTLE LESS CAPPING EACH DAY...AND SLOWLY IMPROVING DIURNAL POPS AS A SERIES OF WEAK UPSTREAM SHORTWAVES PASSES NORTH OF THE AREA. ANY CONVECTION THAT GETS GOING COULD BE QUITE STRONG WITH ANTICIPATED TOTAL TOTALS WELL INTO THE 50S. EXPECT TEMPS ABOUT TWO CATEGORIES ABOVE CLIMO ON SUNDAY TO SURGE TO SOME 10 TO 14 DEGREES ABOVE CLIMO BY TUESDAY. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 300 AM EDT SATURDAY...A FLAT RIDGE WILL PERSIST OVER THE SOUTH WED THROUGH FRI. AT THE SURFACE...A WEAK FRONTAL ZONE WILL STALL OUT ALONG THE NC/VA LINE TUE NIGHT INTO WED...BUT THEN LIFT BACK NORTHWARD AS A WARM FRONT THROUGH THU. FLOW WILL BE GENERALLY WESTERLY DURING THIS PERIOD WHICH WILL ENHANCE WARMING BUT COULD ALSO LEAD TO SOME DOWNSLOPE MIXING/DRYING OF DEWPOINTS EACH AFTERNOON. ANTICIPATE PLENTY OF UPPER 90S TO 100S TEMPS EACH AFTERNOON...SO EVEN IF DEWPOINTS MIX TOWARD THE LOWER TO MIDDLE 60S...SE PIEDMONT HEAT INDEX VALUES COULD APPROACH 105...ESPECIALLY ON WED. AN HWO MENTION COULD BE NEEDED. DESPITE THE WEAK CAPPING ALOFT...WILL FEATURE FAIRLY SOLID CHC POPS IN THE MTNS AND ISOLD POPS EAST CLOSER TO THE LEE TROUGH EACH AFTN/EVENING. ANY TSTMS THAT DEVELOP COULD BE QUITE ROBUST GIVEN THE WARM TEMPERATURES AND CONTINUED STEEP TOTAL TOTALS IN MODEL PROFILES. HEIGHT FALLS ARE EXPECTED FROM THE NW ON FRI...WITH AN APPROACHING COLD FRONT AS WELL. LOW LEVEL THICKNESSES WILL REMAIN WARM ENOUGH FOR ADDITIONAL MID TO UPPER 90S MAXES IN THE SE HALF...BUT THE HEAT WAVE SHOULD START COMING TO AN END WITH THE PATTERN CHANGE TOWARD AN EASTERN TROUGH HEADING INTO NEXT WEEKEND. WILL FEATURE CONTINUED DIURNAL CHANCE POPS AHEAD OF THE APPROACHING FRONT. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... AT KCLT...MAIN CONCERN FOR THIS TAF CYCLE IS THE THUNDERSTORM POTENTIAL. A BAND OF TSRA IS BEGINNING TO DEVELOP JUST WEST OF THE AIRFILED WITH ANOTHER IN WESTERN SC INTO GA. THEREFORE...EXPECT THAT THE AIRFIELD MAY SEE A COUPLE ROUNDS OF TSRA IN THE 19Z-23Z TIMEFRAME. HENCE HAVE A TEMPO WITH RESTRICTIONS. CONVECTIVE THREAT SHOULD END AFTER 00Z AS A SFC TROUGH MOVES SE OF THE AREA. OTHERWISE...VFR CONDITIONS. ELSEWHERE...CONVECTION DEVELOPING IN BANDS ACROSS THE AREA ONE WEST OF CLT AND ANOTHER OVER WESTERN SC INTO GA. THESE FEATURES WILL MOVE EASTWARD. THEREFORE...EXPECT ALL AIRFIELDS WILL EXPERIENCE A TSRA PRIOR TO 00Z. WILL HAVE TEMPOS WITH RESTRICTIONS AT ALL TAF SITES. CONVECTIVE THREAT WILL END AFTER 00Z AS A SFC TROUGH MOVES SE OF THE AREA. AFTER 00Z EXPECT VFR GENERALLY CONDITIONS. THE EXCEPTION WILL BE THE POTENTIAL FOR FOG DEVLOPMENT AT AVL AND HKY EARLY SUNDAY. OUTLOOK...PRECIPITATION CHANCES WILL BE DIURNAL AS ANOTHER SUBTROPICAL RIDGE SETS UP LATE IN THE WEEKEND INTO THE NEW WORK WEEK. AS A RESULT...THE GREATEST CHANCES FOR AFTERNOON SHRA/TSRA WILL BE ACROSS WESTERN NC WHERE THE LEAST SUBSIDENCE WILL RESIDE. MORNING RESTRICTIONS DUE TO FOG AND/OR STRATUS ARE POSSIBLE... PARTICULARLY WHERE HEAVY RAIN FELL THE PREVIOUS DAY...AND IN MTN VALLEYS. CONFIDENCE TABLE... 18-24Z 00-06Z 06-12Z 12-18Z KCLT HIGH 94% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 94% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 88% HIGH 100% HIGH 88% HIGH 97% KHKY HIGH 94% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 88% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 88% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .CLIMATE... RECORD MAXIMUM TEMPERATURES FOR TUESDAY JUNE 23RD... AVL 93 1988 CLT 98 1988 GSP 99 1988 RECORD MAXIMUM TEMPERATURES FOR WEDNESDAY JUNE 24TH... AVL 94 1952 CLT 102 1930 GSP 100 1952 RECORD MAXIMUM TEMPERATURES FOR THURSDAY JUNE 25TH... AVL 96 1952 CLT 102 1914 GSP 101 1952 && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...HG NEAR TERM...LG SHORT TERM...HG LONG TERM...HG AVIATION...LG CLIMATE...
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1233 PM EDT SAT JUN 20 2015 .SYNOPSIS... THE REMNANT CIRCULATION OF TROPICAL SYSTEM BILL WILL MOVE UP THE OHIO VALLEY TODAY...CROSS THE APPALACHIANS TONIGHT...THEN MOVE OFF THE MID ATLANTIC COAST ON SUNDAY. DEEPER MOISTURE WITH THIS SYSTEM WILL BRUSH WESTERN NORTH CAROLINA MAINLY THIS EVENING. HIGH PRESSURE WILL STEADILY BUILD BACK INTO THE AREA BEHIND THE DEPARTING WAVE THROUGH THE MIDDLE OF NEXT WEEK...WITH HOT TEMPERATURES RETURNING AS A STATIONARY FRONT STAYS NORTH OF THE REGION. THE RIDGE OF HIGH PRESSURE WILL START TO BREAK DOWN TOWARD NEXT WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AT 1225 PM...RADAR SHOWS A BAND OF SHOWERS/TSRA FROM THE NORTHERN NC MOUNTAINS SW INTO NE GA. THIS BAND SHOULD MOVE EASTWARD THROUGHOUT THE AFTERNOON. SOME WIDELY SCT SHOWERS DEVELOPING IN UNSTABLE AIRMASS OVER THE PIEDMONT AS SBCAPES IN THE 2000J PLUS THERE. BUMPED POPS UPWARD ACROSS NE GA AND UPSTATE SC IN DEFERENCE TO CURRENT RADAR TRENDS. LATEST DCAPE FROM SPC MESO ANAL SHOWS THE AXIS OF 1000J PLUS NOW WELL EAST OF THE AREA WITH ABOUT 800J NEAR CLT. HENCE...GREATEST THREAT FOR SEVERE STILL SEEMS TO BE OVER EASTERN AREAS WITH THE BEST OVERLAP OF CAPE/DCAPE MAXES. AT 10 AM...REGIONAL RADARS SHOW AN AREA OF SHOWERS OVER FAR WESTERN NC WHICH WAS MOVING EAST. LATEST HRRR BRINGS ANOTHER BAND OF SHRA/TSRA INTO THE MOUNTAINS FROM TN CIRCA 18Z AND MOVES THIS EASTWARD THROUGH 00Z. THE HRRR ALSO GENERATES SOME WIDELY SCT TSRA OVER UPSTATE SC. 12Z NAM IS FAVORING WESTERN NC AS WELL WITH GREATEST QPF RESPONSE...SO WILL MAINTAIN LIKELY/CAT POPS THROUGH THE MOUNTAINS THIS AFTERNOON... TRENDING DOWNWARD TO WIDELY SCT TYPE POPS LOWER PIEDMONT. ADJUSTED MAX TEMPS UPWARD EASTERN AREAS WHERE THE MOST INSOLATION WILL OCCUR. CURRENT INDICATIONS ARE THAT PERHAPS THE GREATEST THREAT FOR SEVERE STORMS WILL BE OVER EASTERN AREAS WHERE CAPES IN EXCESS OF 2000J/KG WILL OVERLAP WITH DCAPES AROUND 1000J. 630 AM EDT UPDATE...NOT MUCH CHANGE IN THE GOING GRIDS WITH TEMPS AND TD/S REMAINING FAIRLY STEADY STEADY STATE. CLOUDS AND POPS WERE ADJ UP ACROSS THE SW NC MTNS WHERE THE FIRST WAVES OF MOISTURE ARE COMING IN FROM EXTROP STORM BILL AND PRODUCING MODERATE SHOWERS. THE REMNANTS OF TS BILL WILL MOVE NE ACROSS WRN KY TODAY WITH THE BEST DYNAMICAL QG FORCING MAINTAINED NW OF THE CWFA. THERE WILL BE SOME LOW END H7/H5 DCVA CROSSING THE WRN ZONES AS THE UPPER S/W TROF AXIS APPROACHES THE APPS. EVEN WITH THE UPPER RIDGE BREAKING DOWN THERE WILL MAINLY BE A SUPRESSIVE ATMOS IN PLACE ACROSS MOST OF THE FA DUE TO MLVL WAA AND MOISTURE ADV. DROPPED SOUNDINGS ACROSS THE WRN ZONES SHOW MLVL THETA/E INCREASING AND SATURATED PROFILES AFT 18Z ABOVE H7...WHILE THE SE/RN AREAS REMAIN RELATIVELY DRY ABOVE THE LFC. THUS...SBCAPE VALUES WILL VARY SIGFNTLY AND ACTUALLY DECREASE THROUGHOUT THE DAY ACROSS THE NC MTN AND FTHILL ZONES...WITH SOME MEASURE OF DECREASE OVER THE UPSTATE AND NE GA AS WELL. THE BEST CHANCE FOR DEEP CONVECTION THEREFORE WILL BE ACROSS THE I-77 CORRIDOOR AND ALONG AND NORTH OF THE I-40 CORRIDOOR. BULK SHEAR WILL INCREASE AS THE EXTROP SYSTEM NEARS AND THE BEST OVERLAP WITH INSTABILITY WILL GENRALLY BE OVER THE I-77 CORRIDOOR. DIFFERNTIAL HEATING ACROSS THE NC PIEDMONT AND ERN FTHILLS SHOULD ALLOW STRONG MULTICELL CLUSTER STORMS TO DEVELOP AS WELL WITH THE MAIN THREAT BEING DAMAGING STRAIGHT-LINE WINDS. HODOS REMAIN TOO STRAIGHT FOR MUCH OF A TOR THREAT...BUT AN ISOL WEAK TOR IS POSSIBLE GIVEN THE INCREASING SHEAR AND HORIZONTAL VORTICITY. LLVL LAPSE RATES AND DRY SUB CLOUD LAYER AIR OUTSIDE THE MTNS ALSO SUPPORT A WIND THREAT AND GUSTY CONDS WILL PREVAIL THROUGH THE AFTERNOON. TEMPERATURES WILL BE TRICKY DEPENDING ON THE AMOUNT OF MOIST ADV...BUT BELIEVE WITH THE LOWERING THICKNESSES MAXES WILL BE A CAT OR SO LOWER THAN FRI/S HIGHS OVER MOST LOCALES. LINGERING LOW TO MID LEVEL MOISTURE WILL TRAVERSE THE CWFA OVERNIGHT AS THE BASE OF THE TROF AXIS SLOWLY LIFTS NE. CHANCE POPS WILL BE LIMITED TO NC MTNS AND NRN FTHILLS IN MOIST WLY FLOW THROUGH 06Z OR SO AND DIMINISH THROUGH DAYBREAK WITH LOSS OF FORCING. MINS WILL BE A COUPLE DEGREES COOLER THAN THE LATEST TRENDS YET STILL A CAT ABOVE NORMAL. && .SHORT TERM /SUNDAY THROUGH TUESDAY/... AS OF 300 AM EDT SATURDAY...THE MID LEVEL TROUGH AND LOW LEVEL CIRCULATION ASSOCIATED WITH THE REMNANTS OF TROPICAL SYSTEM BILL WILL DEPART THE MID ATLANTIC COAST ON SUNDAY. EXPECT A WESTERLY DOWNSLOPING FLOW ACROSS THE REGION IN THE WAKE OF THE SYSTEM. THIS WILL LEAD TO SURFACE RIDGING OVER THE APPALACHIANS...WITH PIEDMONT TROUGHING SETTING UP SUNDAY THROUGH TUESDAY. LOW LEVELS WILL HEAT UP AGAIN VERY QUICKLY...WITH STEEP 850 TO 500 MB LAPSE RATES OF 7 TO 7.5 DEG C/KM EACH DAY GETTING ESTABLISHED. HOWEVER... MODEL PROFILES VARY WIDELY ON SB CAPE VALUES EACH AFTERNOON DUE TO VARIATIONS IN THE MID LEVEL TEMPS AND DEGREE OF CAPPING. WILL PLAN ON A LITTLE LESS CAPPING EACH DAY...AND SLOWLY IMPROVING DIURNAL POPS AS A SERIES OF WEAK UPSTREAM SHORTWAVES PASSES NORTH OF THE AREA. ANY CONVECTION THAT GETS GOING COULD BE QUITE STRONG WITH ANTICIPATED TOTAL TOTALS WELL INTO THE 50S. EXPECT TEMPS ABOUT TWO CATEGORIES ABOVE CLIMO ON SUNDAY TO SURGE TO SOME 10 TO 14 DEGREES ABOVE CLIMO BY TUESDAY. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 300 AM EDT SATURDAY...A FLAT RIDGE WILL PERSIST OVER THE SOUTH WED THROUGH FRI. AT THE SURFACE...A WEAK FRONTAL ZONE WILL STALL OUT ALONG THE NC/VA LINE TUE NIGHT INTO WED...BUT THEN LIFT BACK NORTHWARD AS A WARM FRONT THROUGH THU. FLOW WILL BE GENERALLY WESTERLY DURING THIS PERIOD WHICH WILL ENHANCE WARMING BUT COULD ALSO LEAD TO SOME DOWNSLOPE MIXING/DRYING OF DEWPOINTS EACH AFTERNOON. ANTICIPATE PLENTY OF UPPER 90S TO 100S TEMPS EACH AFTERNOON...SO EVEN IF DEWPOINTS MIX TOWARD THE LOWER TO MIDDLE 60S...SE PIEDMONT HEAT INDEX VALUES COULD APPROACH 105...ESPECIALLY ON WED. AN HWO MENTION COULD BE NEEDED. DESPITE THE WEAK CAPPING ALOFT...WILL FEATURE FAIRLY SOLID CHC POPS IN THE MTNS AND ISOLD POPS EAST CLOSER TO THE LEE TROUGH EACH AFTN/EVENING. ANY TSTMS THAT DEVELOP COULD BE QUITE ROBUST GIVEN THE WARM TEMPERATURES AND CONTINUED STEEP TOTAL TOTALS IN MODEL PROFILES. HEIGHT FALLS ARE EXPECTED FROM THE NW ON FRI...WITH AN APPROACHING COLD FRONT AS WELL. LOW LEVEL THICKNESSES WILL REMAIN WARM ENOUGH FOR ADDITIONAL MID TO UPPER 90S MAXES IN THE SE HALF...BUT THE HEAT WAVE SHOULD START COMING TO AN END WITH THE PATTERN CHANGE TOWARD AN EASTERN TROUGH HEADING INTO NEXT WEEKEND. WILL FEATURE CONTINUED DIURNAL CHANCE POPS AHEAD OF THE APPROACHING FRONT. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... AT KCLT...AREA OBS INDICATE VSBYS LOWERING INTO THE MVFR RANGE NORTH OF THE AIRFIELD WHERE PREVIOUS PRECIP WAS THE GREATEST YESTERDAY. DOESN/T LOOK LIKE THE AIRFIELD WILL BE AFFECTED WITH TDD/S REMAINING AT 6 DEGREES F. STRONG AFTERNOON CONVECTION WILL ONCE AGAIN BE IN PLAY AND A PROB30 TS WILL COVER THE SCT POTENTIAL THRU 00Z. WINDS WILL INCREASE OUT OF THE SW AND BECOME MODERATELY GUSTY AS THE PGRAD TIGHTENS WITHIN GOOD MIXING. NO SIGFNT ISSUES OVERNIGHT AS UPPER TROF PULLS NE AND MID/HIGH CLOUDS MOVE IN...PERHAPS SOME LATE MORNING MVFR VSBY. ELSEWHERE...LOW CIGS AND VSBY AT KAVL AND KHKY WILL BEGIN TO IMPROVE THROUGH 13Z/14Z AS WINDS ARE INFLUENCED BY EXTROP STORM BILL. NC SITES WILL BE UNDER A PROB30 TS THIS AFTERNOON WITH WITH VCTS AT THE SC SITES DUE TO UNCERTAINTY WITH INSTABILITY. THE PGRAD TIGHTENS THROUGH THE DAY AND GOOD MIXING INTO LOW THETA/E WILL ALLOW FOR MODERATE SW/LY GUSTINESS AT ALL SITES THROUGH 00Z. KAVL SHOULD SEE LOWER END GUSTS DUE TO TERRAIN BLOCKAGE OF THE MEAN FLOW. MTN VALLEYS FG EARLY MORNING IS UNCERTAIN DUE TO PERSISTENT SFC FLOW...SO WILL LEAVE OUT OF KAVL TAF FOR NOW. OUTLOOK...PRECIPITATION CHANCES WILL BECOME INCREASINGLY DIURNAL AS ANOTHER SUBTROPICAL RIDGE SETS UP LATE IN THE WEEKEND INTO THE NEW WORK WEEK. AS A RESULT...THE GREATEST CHANCES FOR AFTERNOON SHRA/TSRA WILL BE ACROSS WESTERN NC WHERE THE LEAST SUBSIDENCE WILL RESIDE. MORNING RESTRICTIONS DUE TO FOG AND/OR STRATUS ARE POSSIBLE...PARTICULARLY WHERE HEAVY RAIN FELL THE PREVIOUS DAY...AND IN MTN VALLEYS. CONFIDENCE TABLE... 16-22Z 22-04Z 04-10Z 10-12Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 100% MED 74% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .CLIMATE... RECORD MAXIMUM TEMPERATURES FOR TUESDAY JUNE 23RD... AVL 93 1988 CLT 98 1988 GSP 99 1988 RECORD MAXIMUM TEMPERATURES FOR WEDNESDAY JUNE 24TH... AVL 94 1952 CLT 102 1930 GSP 100 1952 RECORD MAXIMUM TEMPERATURES FOR THURSDAY JUNE 25TH... AVL 96 1952 CLT 102 1914 GSP 101 1952 && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...HG NEAR TERM...LG SHORT TERM...HG LONG TERM...HG AVIATION...SBK CLIMATE...
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1024 AM EDT SAT JUN 20 2015 .SYNOPSIS... THE REMNANT CIRCULATION OF TROPICAL SYSTEM BILL WILL MOVE UP THE OHIO VALLEY TODAY...CROSS THE APPALACHIANS TONIGHT...THEN MOVE OFF THE MID ATLANTIC COAST ON SUNDAY. DEEPER MOISTURE WITH THIS SYSTEM WILL BRUSH WESTERN NORTH CAROLINA MAINLY THIS EVENING. HIGH PRESSURE WILL STEADILY BUILD BACK INTO THE AREA BEHIND THE DEPARTING WAVE THROUGH THE MIDDLE OF NEXT WEEK...WITH HOT TEMPERATURES RETURNING AS A STATIONARY FRONT STAYS NORTH OF THE REGION. THE RIDGE OF HIGH PRESSURE WILL START TO BREAK DOWN TOWARD NEXT WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AT 10 AM...REGIONAL RADARS SHOW AN AREA OF SHOWERS OVER FAR WESTERN NC WHICH WAS MOVING EAST. LATEST HRRR BRINGS ANOTHER BAND OF SHRA/TSRA INTO THE MOUNTAINS FROM TN CIRCA 18Z AND MOVES THIS EASTWARD THROUGH 00Z. THE HRRR ALSO GENERATES SOME WIDELY SCT TSRA OVER UPSTATE SC. 12Z NAM IS FAVORING WESTERN NC AS WELL WITH GREATEST QPF RESPONSE...SO WILL MAINTAIN LIKELY/CAT POPS THROUGH THE MOUNTAINS THIS AFTERNOON... TRENDING DOWNWARD TO WIDELY SCT TYPE POPS LOWER PIEDMONT. ADJUSTED MAX TEMPS UPWARD EASTERN AREAS WHERE THE MOST INSOLATION WILL OCCUR. CURRENT INDICATIONS ARE THAT PERHAPS THE GREATEST THREAT FOR SEVERE STORMS WILL BE OVER EASTERN AREAS WHERE CAPES IN EXCESS OF 2000J/KG WILL OVERLAP WITH DCAPES AROUND 1000J. 630 AM EDT UPDATE...NOT MUCH CHANGE IN THE GOING GRIDS WITH TEMPS AND TD/S REMAINING FAIRLY STEADY STEADY STATE. CLOUDS AND POPS WERE ADJ UP ACROSS THE SW NC MTNS WHERE THE FIRST WAVES OF MOISTURE ARE COMING IN FROM EXTROP STORM BILL AND PRODUCING MODERATE SHOWERS. THE REMNANTS OF TS BILL WILL MOVE NE ACROSS WRN KY TODAY WITH THE BEST DYNAMICAL QG FORCING MAINTAINED NW OF THE CWFA. THERE WILL BE SOME LOW END H7/H5 DCVA CROSSING THE WRN ZONES AS THE UPPER S/W TROF AXIS APPROACHES THE APPS. EVEN WITH THE UPPER RIDGE BREAKING DOWN THERE WILL MAINLY BE A SUPRESSIVE ATMOS IN PLACE ACROSS MOST OF THE FA DUE TO MLVL WAA AND MOISTURE ADV. DROPPED SOUNDINGS ACROSS THE WRN ZONES SHOW MLVL THETA/E INCREASING AND SATURATED PROFILES AFT 18Z ABOVE H7...WHILE THE SE/RN AREAS REMAIN RELATIVELY DRY ABOVE THE LFC. THUS...SBCAPE VALUES WILL VARY SIGFNTLY AND ACTUALLY DECREASE THROUGHOUT THE DAY ACROSS THE NC MTN AND FTHILL ZONES...WITH SOME MEASURE OF DECREASE OVER THE UPSTATE AND NE GA AS WELL. THE BEST CHANCE FOR DEEP CONVECTION THEREFORE WILL BE ACROSS THE I-77 CORRIDOOR AND ALONG AND NORTH OF THE I-40 CORRIDOOR. BULK SHEAR WILL INCREASE AS THE EXTROP SYSTEM NEARS AND THE BEST OVERLAP WITH INSTABILITY WILL GENRALLY BE OVER THE I-77 CORRIDOOR. DIFFERNTIAL HEATING ACROSS THE NC PIEDMONT AND ERN FTHILLS SHOULD ALLOW STRONG MULTICELL CLUSTER STORMS TO DEVELOP AS WELL WITH THE MAIN THREAT BEING DAMAGING STRAIGHT-LINE WINDS. HODOS REMAIN TOO STRAIGHT FOR MUCH OF A TOR THREAT...BUT AN ISOL WEAK TOR IS POSSIBLE GIVEN THE INCREASING SHEAR AND HORIZONTAL VORTICITY. LLVL LAPSE RATES AND DRY SUB CLOUD LAYER AIR OUTSIDE THE MTNS ALSO SUPPORT A WIND THREAT AND GUSTY CONDS WILL PREVAIL THROUGH THE AFTERNOON. TEMPERATURES WILL BE TRICKY DEPENDING ON THE AMOUNT OF MOIST ADV...BUT BELIEVE WITH THE LOWERING THICKNESSES MAXES WILL BE A CAT OR SO LOWER THAN FRI/S HIGHS OVER MOST LOCALES. LINGERING LOW TO MID LEVEL MOISTURE WILL TRAVERSE THE CWFA OVERNIGHT AS THE BASE OF THE TROF AXIS SLOWLY LIFTS NE. CHANCE POPS WILL BE LIMITED TO NC MTNS AND NRN FTHILLS IN MOIST WLY FLOW THROUGH 06Z OR SO AND DIMINISH THROUGH DAYBREAK WITH LOSS OF FORCING. MINS WILL BE A COUPLE DEGREES COOLER THAN THE LATEST TRENDS YET STILL A CAT ABOVE NORMAL. && .SHORT TERM /SUNDAY THROUGH TUESDAY/... AS OF 300 AM EDT SATURDAY...THE MID LEVEL TROUGH AND LOW LEVEL CIRCULATION ASSOCIATED WITH THE REMNANTS OF TROPICAL SYSTEM BILL WILL DEPART THE MID ATLANTIC COAST ON SUNDAY. EXPECT A WESTERLY DOWNSLOPING FLOW ACROSS THE REGION IN THE WAKE OF THE SYSTEM. THIS WILL LEAD TO SURFACE RIDGING OVER THE APPALACHIANS...WITH PIEDMONT TROUGHING SETTING UP SUNDAY THROUGH TUESDAY. LOW LEVELS WILL HEAT UP AGAIN VERY QUICKLY...WITH STEEP 850 TO 500 MB LAPSE RATES OF 7 TO 7.5 DEG C/KM EACH DAY GETTING ESTABLISHED. HOWEVER... MODEL PROFILES VARY WIDELY ON SB CAPE VALUES EACH AFTERNOON DUE TO VARIATIONS IN THE MID LEVEL TEMPS AND DEGREE OF CAPPING. WILL PLAN ON A LITTLE LESS CAPPING EACH DAY...AND SLOWLY IMPROVING DIURNAL POPS AS A SERIES OF WEAK UPSTREAM SHORTWAVES PASSES NORTH OF THE AREA. ANY CONVECTION THAT GETS GOING COULD BE QUITE STRONG WITH ANTICIPATED TOTAL TOTALS WELL INTO THE 50S. EXPECT TEMPS ABOUT TWO CATEGORIES ABOVE CLIMO ON SUNDAY TO SURGE TO SOME 10 TO 14 DEGREES ABOVE CLIMO BY TUESDAY. && .LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/... AS OF 300 AM EDT SATURDAY...A FLAT RIDGE WILL PERSIST OVER THE SOUTH WED THROUGH FRI. AT THE SURFACE...A WEAK FRONTAL ZONE WILL STALL OUT ALONG THE NC/VA LINE TUE NIGHT INTO WED...BUT THEN LIFT BACK NORTHWARD AS A WARM FRONT THROUGH THU. FLOW WILL BE GENERALLY WESTERLY DURING THIS PERIOD WHICH WILL ENHANCE WARMING BUT COULD ALSO LEAD TO SOME DOWNSLOPE MIXING/DRYING OF DEWPOINTS EACH AFTERNOON. ANTICIPATE PLENTY OF UPPER 90S TO 100S TEMPS EACH AFTERNOON...SO EVEN IF DEWPOINTS MIX TOWARD THE LOWER TO MIDDLE 60S...SE PIEDMONT HEAT INDEX VALUES COULD APPROACH 105...ESPECIALLY ON WED. AN HWO MENTION COULD BE NEEDED. DESPITE THE WEAK CAPPING ALOFT...WILL FEATURE FAIRLY SOLID CHC POPS IN THE MTNS AND ISOLD POPS EAST CLOSER TO THE LEE TROUGH EACH AFTN/EVENING. ANY TSTMS THAT DEVELOP COULD BE QUITE ROBUST GIVEN THE WARM TEMPERATURES AND CONTINUED STEEP TOTAL TOTALS IN MODEL PROFILES. HEIGHT FALLS ARE EXPECTED FROM THE NW ON FRI...WITH AN APPROACHING COLD FRONT AS WELL. LOW LEVEL THICKNESSES WILL REMAIN WARM ENOUGH FOR ADDITIONAL MID TO UPPER 90S MAXES IN THE SE HALF...BUT THE HEAT WAVE SHOULD START COMING TO AN END WITH THE PATTERN CHANGE TOWARD AN EASTERN TROUGH HEADING INTO NEXT WEEKEND. WILL FEATURE CONTINUED DIURNAL CHANCE POPS AHEAD OF THE APPROACHING FRONT. && .AVIATION /15Z SATURDAY THROUGH WEDNESDAY/... AT KCLT...AREA OBS INDICATE VSBYS LOWERING INTO THE MVFR RANGE NORTH OF THE AIRFIELD WHERE PREVIOUS PRECIP WAS THE GREATEST YESTERDAY. DOESN/T LOOK LIKE THE AIRFIELD WILL BE AFFECTED WITH TDD/S REMAINING AT 6 DEGREES F. STRONG AFTERNOON CONVECTION WILL ONCE AGAIN BE IN PLAY AND A PROB30 TS WILL COVER THE SCT POTENTIAL THRU 00Z. WINDS WILL INCREASE OUT OF THE SW AND BECOME MODERATELY GUSTY AS THE PGRAD TIGHTENS WITHIN GOOD MIXING. NO SIGFNT ISSUES OVERNIGHT AS UPPER TROF PULLS NE AND MID/HIGH CLOUDS MOVE IN...PERHAPS SOME LATE MORNING MVFR VSBY. ELSEWHERE...LOW CIGS AND VSBY AT KAVL AND KHKY WILL BEGIN TO IMPROVE THROUGH 13Z/14Z AS WINDS ARE INFLUENCED BY EXTROP STORM BILL. NC SITES WILL BE UNDER A PROB30 TS THIS AFTERNOON WITH WITH VCTS AT THE SC SITES DUE TO UNCERTAINTY WITH INSTABILITY. THE PGRAD TIGHTENS THROUGH THE DAY AND GOOD MIXING INTO LOW THETA/E WILL ALLOW FOR MODERATE SW/LY GUSTINESS AT ALL SITES THROUGH 00Z. KAVL SHOULD SEE LOWER END GUSTS DUE TO TERRAIN BLOCKAGE OF THE MEAN FLOW. MTN VALLEYS FG EARLY MORNING IS UNCERTAIN DUE TO PERSISTENT SFC FLOW...SO WILL LEAVE OUT OF KAVL TAF FOR NOW. OUTLOOK...PRECIPITATION CHANCES WILL BECOME INCREASINGLY DIURNAL AS ANOTHER SUBTROPICAL RIDGE SETS UP LATE IN THE WEEKEND INTO THE NEW WORK WEEK. AS A RESULT...THE GREATEST CHANCES FOR AFTERNOON SHRA/TSRA WILL BE ACROSS WESTERN NC WHERE THE LEAST SUBSIDENCE WILL RESIDE. MORNING RESTRICTIONS DUE TO FOG AND/OR STRATUS ARE POSSIBLE...PARTICULARLY WHERE HEAVY RAIN FELL THE PREVIOUS DAY...AND IN MTN VALLEYS. CONFIDENCE TABLE... 14-20Z 20-02Z 02-08Z 08-12Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 85% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .CLIMATE... RECORD MAXIMUM TEMPERATURES FOR TUESDAY JUNE 23RD... AVL 93 1988 CLT 98 1988 GSP 99 1988 RECORD MAXIMUM TEMPERATURES FOR WEDNESDAY JUNE 24TH... AVL 94 1952 CLT 102 1930 GSP 100 1952 RECORD MAXIMUM TEMPERATURES FOR THURSDAY JUNE 25TH... AVL 96 1952 CLT 102 1914 GSP 101 1952 && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...HG NEAR TERM...LG SHORT TERM...HG LONG TERM...HG AVIATION...SBK CLIMATE...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1215 PM CDT FRI JUN 19 2015 .UPDATE... ISSUED AT 1213 PM CDT FRI JUN 19 2015 MCS FROM OVERNIGHT HOURS HAS GREATLY DISSIPATED FROM EARLIER OVERNIGHT STATUS. REPEATED ATTEMPTS FOR CLUSTERS OF THUNDERSTORMS TO PUSH TO THE EAST OF THE JAMES VALLEY HAS MET WITH A STRONG WEAKENING OR DISSIPATION WITH THE MUCH MORE STABLE CONDITIONS. HRRR/RAP MODELS HAVE NOT DONE WELL IN SUGGESTING THIS DISSIPATION... AND CONTINUE TO STRUGGLE WITH OVERPREDICTION OF CONVECTIVE THREAT IN THE IMMEDIATE TERM. WILL CONTINUE WITH SOME SCATTERED TO LIKELY LEVEL POPS IN THE NORTH FOR A COUPLE HOURS...BUT GRADUALLY SHOULD SEE THREAT DIMINISH TO BARE MINIMUM ALONG MID LEVEL BOUNDARY IN THE FAR NORTH. OTHERWISE...LARGE STRATUS FIELD ACROSS CENTRAL/WESTERN NEBRASKA CONTINUES TO TAUNT THE FAR WESTERN CWA. SHOULD CONTINUE TO UNDERGO DISSIPATION AS IT ADVECTS NORTH TO NORTHEAST THROUGH THE AFTERNOON...BUT MAY HOLD CLOUDS IN FOR A LONGER PERIOD...AND EVEN WITH DISSIPATION...LONG ENOUGH TO IMPACT POTENTIAL HIGHS WEST OF THE JAMES...AND HAVE TRIMMED BACK HIGHS A BIT FOR BOTH THIS AREA...AND THOSE LOCATIONS NEAR THE MORE LINGERING PRECIPITATION THREAT INTO EARLY AFTERNOON. OTHERWISE...FOCUS FOR THE SHORT TERM FORECAST CONTINUES TO BE THE SEVERE CONVECTIVE THREAT TONIGHT. STRONG WAVE MOVING THROUGH IDAHO WILL BE THE TRIGGER THIS EVENING FOR DEVELOPMENT OF MORE SIGNIFICANT CONVECTIVE ACTIVITY ACROSS SOUTHEAST MONTANA/NORTHWEST SOUTH DAKOTA...WHICH WILL PLOW TO THE EAST/SOUTHEAST OVERNIGHT. 0-3KM SHEAR HAS COME IN A BIT STRONGER IN THE PRE COMPLEX ENVIRONMENT...AND LIKELY TO GET SOME ML/ELEVATED CAPE UP TO 1500 J/KG. EVOLUTION TO A LARGER SCALE BOW ECHO WOULD SEEM VERY PLAUSIBLE...PRIMARILY WITH A THREAT FOR DAMAGING WINDS GUSTS 70 TO 80 MPH. SOME LARGE HAIL POTENTIAL WILL EXIST ACROSS THE WEST AND SOUTHERN FLANKS WITH STRONG LOW LEVEL JET. RAPID MOVEMENT OF SYSTEM ONCE EVOLVED WITH LIKELY LIMIT THE PRECIPITATION AMOUNTS...BUT RATES WILL LIKELY BE QUITE HIGH FOR A BRIEF TIME... WHICH WOULD INTRODUCE THREAT FOR MORE URBANIZED AND POOR DRAINAGE AREAS TO EXPERIENCE SOME WATER ISSUES AS SYSTEM PUSHES THROUGH. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 347 AM CDT FRI JUN 19 2015 COMPLICATED FORECAST FOR TODAY. STRONG MCS CURRENTLY WORKING INTO WESTERN PORTIONS OF THE STATE AS OF 08Z....AND IS EXPECTED TO APPROACH THE WESTERN EDGE OF THE FORECAST AREA IN THE 13-14 Z TIME FRAME. WHAT IS INTERESTING...IS THAT THE AIR OVER THE FORECAST AREA IS COMPLETELY STABLE...BUT OFTEN TIMES...STRONG...WELL ESTABLISHED MCS CAN OUTRUN THE INSTABILITY. HRRR HAS BEEN VERY CONSISTENT WITH THIS...AND RAP IS NOW BEGINNING TO TREND IN THIS DIRECTION AS WELL. HAVE BEGUN TO TREND UPWARDS WITH POPS IN NORTHWEST FORECAST AREA IN CENTRAL SOUTH DAKOTA...BUT TRAIL POPS OFF TO THE EAST AS COMPLEX IS EXPECTED TO FALL APART AS IT WORKS DEEPER INTO THE STABLE AIR. RESIDUAL CLOUD COVER WILL REDUCE HEATING POTENTIAL FOR TODAY...AND HAVE CUT BACK HIGH TEMPERATURES ACROSS THE AREA...WITH GREATEST ADJUSTMENTS IN CENTRAL SOUTH DAKOTA. LOW LEVEL CONVERGENCE INCREASES THIS EVENING AS 35-45 KNOT LOW LEVEL JET DEVELOPS ACROSS THE CENTRAL PLAINS. WHILE STILL CAN/T RULE OUT AN ISOLATED STORM THROUGH THE EVENING HOURS...IT DOES APPEAR THAT THE CAP WILL BE STRONG ENOUGH AHEAD OF THE COLD FRONT AND ASSOCIATED MID LEVEL WAVE TO LIMIT CONVECTIVE POTENTIAL INITIALLY TO ISOLATED AT BEST. MUCH BETTER FOCUS FOR CONVECTION WILL BE ACROSS THE WESTERN REACHES OF THE STATE IN THE EVENING HOURS ALONG THE COLD FRONT. BASED ON SHEAR AND STORM MOTION...EXPECTING STORMS TO ORGANIZE INTO A MATURE MCS AND WORK INTO WESTERN PORTIONS OF THE FORECAST AREA 05-07Z. EXPECT STORMS TO BE ELEVATED...BUT WITH RELATIVELY DRY LAYER FROM 750 UP TO 300 MB...POTENTIAL FOR STRONG ORGANIZED MCS TO CREATE DAMAGING WINDS. 0-3 KM BULK SHEAR VECTORS NEAR 30-35 KNOTS ACROSS THE NORTHERN HALF OF THE FORECAST AREA....INDICATING DAMAGING WIND POTENTIAL ALONG AND NORTH OF I-90. AS STORMS WORK EAST OF I-29 AFTER 9Z...SEVERE WEATHER PARAMETERS DECREASE AND AM EXPECTING THE OVERALL INTENSITY TO DECREASE. WITH THAT SAID...STILL KEPT POPS IN THE CATEGORICAL RANGE ACROSS THE NORTH CLOSEST TO THE MID LEVEL WAVE...WITH LESSER CHANCES TO THE SOUTH ESPECIALLY SOUTH OF I-90 AS ONE GETS FURTHER AWAY FROM THE MID LEVEL WAVE AND THE UPPER JET. HAVE ADDED MENTION OF CHANCE OF LARGE HAIL AND DAMAGING WINDS TO WEATHER GRIDS...BUT WAS LESS CONFIDENT EAST OF I-29 AND DECREASED TO SLIGHT CHANCE ACROSS SOUTHWEST MINNESOTA WHERE SEVERE PARAMETERS AND SPC OUTLOOK DECREASE. HAVE COOLED LOWS SLIGHTLY ACROSS THE NORTH WHERE CONVECTION SEEMS LIKELY...AND LEFT TEMPERATURES SOUTH OF I-90 QUITE MILD IN THE UPPER 60S WHERE WIDESPREAD RAIN CHANCES ARE. WITH 0-2 KM VGP AND 0-3 KM EHI SUGGESTING SUPERCELLS...WILL KEEP MENTION OF LARGE HAIL AND DAMAGING WINDS IN THE HWO. HAVE ALSO MENTIONED IN THE GRIDS...WITH LESSER CHANCES OF WIDESPREAD SEVERE EAST OF I-29. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 347 AM CDT FRI JUN 19 2015 ON SATURDAY...THE CONVECTIVE COMPLEX SHOULD BE RAPIDLY EXITING OUR EASTERN ZONES IN THE MORNING. FURTHERMORE...THE WIND SHIFT TO THE NORTH AND NORTHWEST IS FORECAST TO MOVE ACROSS THE FORECAST AREA FAIRLY EARLY IN THE DAY WHICH SHOULD BUILD STORMS AWAY FROM OUR LOCATION IN THE AFTERNOON. WITH GOOD MIXING POTENTIAL AND SOME DRY AIR ADVECTION...HIGHS STILL LOOK WARM WITH WIDESPREAD 80S. CURRENTLY HAVE 89 AT SIOUX CITY BUT WOULD NOT BE SURPRISED IF THEY HIT 90 OR THE LOWER 90S IF THE MID AND UPPER CLOUD COVER EXITS QUICKLY ENOUGH BY MIDDAY. HIGH PRESSURE DOMINATES SATURDAY NIGHT...HELPING TO GIVE LIGHT WINDS AND WHAT SHOULD BE A DRY NIGHT. THEN ON SUNDAY...THE VARIOUS MODELS INCLUDING THE GFS...ECMWF AND NAM SHOW A WEAK SHORT WAVE IMPACTING THE FORECAST AREA...ESPECIALLY FOR LOCATIONS WEST OF I 29 AND NORTH OF I 90 IN OUR SOUTH DAKOTA ZONES. LOW LEVEL MOISTURE IS A BIT LACKING AFTER THE WIND SHIFT ON SATURDAY...BUT PLENTY OF MID LEVEL MOISTURE EXISTS WITH SOME DECENT LAPSE RATES BETWEEN 700 AND 500MB. THEREFORE CHANCE POPS ARE WARRANTED IN THE AFOREMENTIONED AREA WITH LESS CHANCES ELSEWHERE. ON SUNDAY NIGHT...SUNDAYS MID LEVEL SHORT WAVE WEAKENS IN OUR EASTERN ZONES AS IT MOVES EASTWARD...REPLACED BY A STRONG SHORT WAVE RAPIDLY MOVING SOUTHEASTWARD ACROSS NORTH DAKOTA AND THE NORTHERN HALF OF MINNESOTA. MOST OF THE DYNAMICS REMAINS NORTH OF THE FORECAST AREA...SO THEREFORE ONLY CHANCE POPS ARE WARRANTED WITH THE HIGHEST POPS ALONG THE HIGHWAY 14 CORRIDOR IN OUR NORTHERN ZONES. LOWS STILL LOOK MILD...ABOUT 60 TO 65 DEGREES WITH THE WINDS CHANGING TO THE NORTH BEHIND THE SHORT WAVE PASSAGE LATE AT NIGHT. CONFIDENCE IS RATHER LOW IN THE EXTENDED IN TERMS OF WHEN AND WHERE THUNDERSTORM CHANCES ARE. IN GENERAL...BOTH THE GFS AND ECMWF ARE SHOWING AN UPPER RIDGE BUILDING ACROSS THE SOUTHERN HALF OF THE UNITED STATES WITH A BRISK QUASI ZONAL FLOW THROUGHOUT THE NORTHERN HALF. THIS TYPE OF PATTERN SHOULD GIVE MILD TEMPERATURES THROUGHOUT THE FORECAST...WITH HIGHS IN THE UPPER 70S TO MID 80S BASED ON THE LATEST 850MB TEMPERATURES OFF OF THE LATEST ECMWF AND GFS. LOWS ARE PRIMARILY IN THE LOWER AND MID 60S...BUT IF WE GET LIGHT WINDS COUPLED WITH CLEAR SKIES...WOULD NOT BE SURPRISED IF LOWS ERROR ON THE COOL SIDE OF SUPERBLEND LOWS HERE AND THERE. DUE TO THE DIFFERENCE BETWEEN THE VARIOUS MODELS WITH SPECIFIC SHORT WAVE TIMING MOVING ACROSS THE FAST UPPER FLOW...PIN POINTING RAIN CHANCES IS REAL PROBLEMATIC. AT THIS TIME...THERE DOES NOT LOOK TO BE A WIDESPREAD RAIN EVENT. THE ONE EXCEPTION TO THIS WHERE THERE IS SOME AGREEMENT IS IN NORTHWEST IOWA AND EXTREME NORTHEAST NEBRASKA LATE TUESDAY NIGHT AND WEDNESDAY MORNING. HOWEVER...BOTH MODELS LOOK LIKE THEY DEVELOP A CONVECTIVELY INDUCED SHORT WAVE...THEREFORE THE SHORT WAVE IN THAT AREA MAY BE A RESPONSE TO CONVECTIVE FEEDBACK. VERY DIFFICULT TO TELL THIS FAR OUT. THERE IS AN 850MB BOUNDARY CLOSE TO NORTHWEST IOWA...AT LEAST EXTENDING THROUGH THE SOUTHERN PORTION OF NORTHWEST IA. SO ITS WORTH WATCHING BUT HIGH POPS ARE NOT WARRANTED YET AT THIS TIME. ANOTHER WEAK COLD FRONT MOVES THROUGH LATER WEDNESDAY NIGHT AND THURSDAY MORNING...BUT AT THIS TIME THE FRONTAL PASSAGE DOES NOT LOOK TO HAVE A LOT OF SHOWER OR STORM ACTIVITY WITH IT. ONE THING OF INTEREST IS THE LONGER RANGE STILL SHOWS THE UPPER RIDGE MIGRATING AND BUILDING ACROSS THE WESTERN UNITED STATES BEYOND THE EXTENDED PERIOD. THAT WOULD PUT THE NORTHERN PLAINS IN A SHORT NORTHWEST FLOW ALOFT FOR THIS TIME OF YEAR. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1213 PM CDT FRI JUN 19 2015 MAIN CONCERN WITH CONVECTIVE SYSTEM EXPECTED TO PUSH ACROSS THE KHON AREA AROUND MIDNIGHT...KFSD A COUPLE HOURS LATER...AND CLIPPING PAST KSUX. VERY STRONG WINDS WILL LIKELY ACCOMPANY THE STORMS...WITH POTENTIAL FOR KHON AREA FOR GUSTS OF 60 TO 65 KTS. LIKELY TO FIND BRIEF PERIODS OF IFR CONDITIONS IN THUNDERSTORMS... BUT WILL LIKELY LIMIT MENTION OVER A COUPLE HOURS TO MVFR AT THIS TIME. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ UPDATE...CHAPMAN SHORT TERM... LONG TERM...MJ AVIATION...CHAPMAN
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
600 AM CDT FRI JUN 19 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 347 AM CDT FRI JUN 19 2015 COMPLICATED FORECAST FOR TODAY. STRONG MCS CURRENTLY WORKING INTO WESTERN PORTIONS OF THE STATE AS OF 08Z....AND IS EXPECTED TO APPROACH THE WESTERN EDGE OF THE FORECAST AREA IN THE 13-14 Z TIME FRAME. WHAT IS INTERESTING...IS THAT THE AIR OVER THE FORECAST AREA IS COMPLETELY STABLE...BUT OFTEN TIMES...STRONG...WELL ESTABLISHED MCS CAN OUTRUN THE INSTABILITY. HRRR HAS BEEN VERY CONSISTENT WITH THIS...AND RAP IS NOW BEGINNING TO TREND IN THIS DIRECTION AS WELL. HAVE BEGUN TO TREND UPWARDS WITH POPS IN NORTHWEST FORECAST AREA IN CENTRAL SOUTH DAKOTA...BUT TRAIL POPS OFF TO THE EAST AS COMPLEX IS EXPECTED TO FALL APART AS IT WORKS DEEPER INTO THE STABLE AIR. RESIDUAL CLOUD COVER WILL REDUCE HEATING POTENTIAL FOR TODAY...AND HAVE CUT BACK HIGH TEMPERATURES ACROSS THE AREA...WITH GREATEST ADJUSTMENTS IN CENTRAL SOUTH DAKOTA. LOW LEVEL CONVERGENCE INCREASES THIS EVENING AS 35-45 KNOT LOW LEVEL JET DEVELOPS ACROSS THE CENTRAL PLAINS. WHILE STILL CAN/T RULE OUT AN ISOLATED STORM THROUGH THE EVENING HOURS...IT DOES APPEAR THAT THE CAP WILL BE STRONG ENOUGH AHEAD OF THE COLD FRONT AND ASSOCIATED MID LEVEL WAVE TO LIMIT CONVECTIVE POTENTIAL INITIALLY TO ISOLATED AT BEST. MUCH BETTER FOCUS FOR CONVECTION WILL BE ACROSS THE WESTERN REACHES OF THE STATE IN THE EVENING HOURS ALONG THE COLD FRONT. BASED ON SHEAR AND STORM MOTION...EXPECTING STORMS TO ORGANIZE INTO A MATURE MCS AND WORK INTO WESTERN PORTIONS OF THE FORECAST AREA 05-07Z. EXPECT STORMS TO BE ELEVATED...BUT WITH RELATIVELY DRY LAYER FROM 750 UP TO 300 MB...POTENTIAL FOR STRONG ORGANIZED MCS TO CREATE DAMAGING WINDS. 0-3 KM BULK SHEAR VECTORS NEAR 30-35 KNOTS ACROSS THE NORTHERN HALF OF THE FORECAST AREA....INDICATING DAMAGING WIND POTENTIAL ALONG AND NORTH OF I-90. AS STORMS WORK EAST OF I-29 AFTER 9Z...SEVERE WEATHER PARAMETERS DECREASE AND AM EXPECTING THE OVERALL INTENSITY TO DECREASE. WITH THAT SAID...STILL KEPT POPS IN THE CATEGORICAL RANGE ACROSS THE NORTH CLOSEST TO THE MID LEVEL WAVE...WITH LESSER CHANCES TO THE SOUTH ESPECIALLY SOUTH OF I-90 AS ONE GETS FURTHER AWAY FROM THE MID LEVEL WAVE AND THE UPPER JET. HAVE ADDED MENTION OF CHANCE OF LARGE HAIL AND DAMAGING WINDS TO WEATHER GRIDS...BUT WAS LESS CONFIDENT EAST OF I-29 AND DECREASED TO SLIGHT CHANCE ACROSS SOUTHWEST MINNESOTA WHERE SEVERE PARAMETERS AND SPC OUTLOOK DECREASE. HAVE COOLED LOWS SLIGHTLY ACROSS THE NORTH WHERE CONVECTION SEEMS LIKELY...AND LEFT TEMPERATURES SOUTH OF I-90 QUITE MILD IN THE UPPER 60S WHERE WIDESPREAD RAIN CHANCES ARE. WITH 0-2 KM VGP AND 0-3 KM EHI SUGGESTING SUPERCELLS...WILL KEEP MENTION OF LARGE HAIL AND DAMAGING WINDS IN THE HWO. HAVE ALSO MENTIONED IN THE GRIDS...WITH LESSER CHANCES OF WIDESPREAD SEVERE EAST OF I-29. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 347 AM CDT FRI JUN 19 2015 ON SATURDAY...THE CONVECTIVE COMPLEX SHOULD BE RAPIDLY EXITING OUR EASTERN ZONES IN THE MORNING. FURTHERMORE...THE WIND SHIFT TO THE NORTH AND NORTHWEST IS FORECAST TO MOVE ACROSS THE FORECAST AREA FAIRLY EARLY IN THE DAY WHICH SHOULD BUILD STORMS AWAY FROM OUR LOCATION IN THE AFTERNOON. WITH GOOD MIXING POTENTIAL AND SOME DRY AIR ADVECTION...HIGHS STILL LOOK WARM WITH WIDESPREAD 80S. CURRENTLY HAVE 89 AT SIOUX CITY BUT WOULD NOT BE SURPRISED IF THEY HIT 90 OR THE LOWER 90S IF THE MID AND UPPER CLOUD COVER EXITS QUICKLY ENOUGH BY MIDDAY. HIGH PRESSURE DOMINATES SATURDAY NIGHT...HELPING TO GIVE LIGHT WINDS AND WHAT SHOULD BE A DRY NIGHT. THEN ON SUNDAY...THE VARIOUS MODELS INCLUDING THE GFS...ECMWF AND NAM SHOW A WEAK SHORT WAVE IMPACTING THE FORECAST AREA...ESPECIALLY FOR LOCATIONS WEST OF I 29 AND NORTH OF I 90 IN OUR SOUTH DAKOTA ZONES. LOW LEVEL MOISTURE IS A BIT LACKING AFTER THE WIND SHIFT ON SATURDAY...BUT PLENTY OF MID LEVEL MOISTURE EXISTS WITH SOME DECENT LAPSE RATES BETWEEN 700 AND 500MB. THEREFORE CHANCE POPS ARE WARRANTED IN THE AFOREMENTIONED AREA WITH LESS CHANCES ELSEWHERE. ON SUNDAY NIGHT...SUNDAYS MID LEVEL SHORT WAVE WEAKENS IN OUR EATERN ZONES AS IT MOVES EASTWARD...REPLACED BY A STRONG SHORT WAVE RAPIDLY MOVING SOUTHEASTWARD ACROSS NORTH DAKOTA AND THE NORTHERN HALF OF MINNESOTA. MOST OF THE DYNAMICS REMAINS NORTH OF THE FORECAST AREA...SO THEREFORE ONLY CHANCE POPS ARE WARRANTED WITH THE HIGHEST POPS ALONG THE HIGHWAY 14 CORRIDOR IN OUR NORTHERN ZONES. LOWS STILL LOOK MILD...ABOUT 60 TO 65 DEGREES WITH THE WINDS CHANGING TO THE NORTH BEHIND THE SHORT WAVE PASSAGE LATE AT NIGHT. CONFIDENCE IS RATHER LOW IN THE EXTENDED IN TERMS OF WHEN AND WHERE THUNDERSTORM CHANCES ARE. IN GENERAL...BOTH THE GFS AND ECMWF ARE SHOWING AN UPPER RIDGE BUILDING ACROSS THE SOUTHERN HALF OF THE UNITED STATES WITH A BRISK QUASI ZONAL FLOW THROUGHOUT THE NORTHERN HALF. THIS TYPE OF PATTERN SHOULD GIVE MILD TEMPERATURES THROUGHOUT THE FORECAST...WITH HIGHS IN THE UPPER 70S TO MID 80S BASED ON THE LATEST 850MB TEMPERATURES OFF OF THE LATEST ECMWF AND GFS. LOWS ARE PRIMARILY IN THE LOWER AND MID 60S...BUT IF WE GET LIGHT WINDS COUPLED WITH CLEAR SKIES...WOULD NOT BE SURPRISED IF LOWS ERROR ON THE COOL SIDE OF SUPERBLEND LOWS HERE AND THERE. DUE TO THE DIFFERENCE BETWEEN THE VARIOUS MODELS WITH SPECIFIC SHORT WAVE TIMING MOVING ACROSS THE FAST UPPER FLOW...PIN POINTING RAIN CHANCES IS REAL PROBLEMATIC. AT THIS TIME...THERE DOES NOT LOOK TO BE A WIDESPREAD RAIN EVENT. THE ONE EXCEPTION TO THIS WHERE THERE IS SOME AGREEMENT IS IN NORTHWEST IOWA AND EXTREME NORTHEAST NEBRASKA LATE TUESDAY NIGHT AND WEDNESDAY MORNING. HOWEVER...BOTH MODELS LOOK LIKE THEY DEVELOP A CONVECTIVELY INDUCED SHORT WAVE...THEREFORE THE SHORT WAVE IN THAT AREA MAY BE A RESPONSE TO CONVECTIVE FEEDBACK. VERY DIFFICULT TO TELL THIS FAR OUT. THERE IS AN 850MB BOUNDARY CLOSE TO NORTHWEST IOWA...AT LEAST EXTENDING THROUGH THE SOUTHERN PORTION OF NORTHWEST IA. SO ITS WORTH WATCHING BUT HIGH POPS ARE NOT WARRANTED YET AT THIS TIME. ANOTHER WEAK COLD FRONT MOVES THROUGH LATER WEDNESDAY NIGHT AND THURSDAY MORNING...BUT AT THIS TIME THE FRONTAL PASSAGE DOES NOT LOOK TO HAVE A LOT OF SHOWER OR STORM ACTIVITY WITH IT. ONE THING OF INTEREST IS THE LONGER RANGE STILL SHOWS THE UPPER RIDGE MIGRATING AND BUILDING ACROSS THE WESTERN UNITED STATES BEYOND THE EXTENDED PERIOD. THAT WOULD PUT THE NORTHERN PLAINS IN A SHORT NORTHWEST FLOW ALOFT FOR THIS TIME OF YEAR. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 552 AM CDT FRI JUN 19 2015 COMPLEX OF WEAKENING STORMS MOVING FROM CENTRAL SOUTH DAKOTA WILL AFFECT HURON AND AREAS NORTH OF I-90 THIS MORNING. EXPECT CONDITIONS TO REMAIN VFR. BREEZY SOUTHEASTERLY WILL DEVELOP THROUGHOUT THE DAY TODAY. AN MCS IS EXPECTED TO ORGANIZE ACROSS THE WESTERN HALF OF THE STATE THIS EVENING...MOVING EAST OF THE MISSOURI RIVER VALLEY AROUND MIDNIGHT. HAVE NOT ADDED WIND POTENTIAL TO THE HURON TAF...BUT MAY NEED TO DO THAT IN FUTURE 18 OR 00Z ISSUANCE. CONFIDENCE IN THUNDERSTORMS FURTHER TO THE SOUTH IS LESS...AND THEREFORE HAVE LEFT MENTION OUT FOR NOW. HOWEVER...STRONG LOW LEVEL JET IS EXPECTED TO DEVELOP ACROSS THE CENTRAL AND NORTHERN PLAINS TONIGHT AND HAVE ADDED MENTION OF LOW LEVEL WIND SHEAR TO SIOUX CITY AND SIOUX FALLS. MAY NEED TO ADD CONVECTION TO TAF AS WELL FOR SIOUX FALLS...BUT CONFIDENCE IS NOT HIGH ENOUGH AT THIS TIME TO INCLUDE MENTION. BEST CHANCES FOR CONVECTION IN SIOUX FALLS WILL BE IN THE 08-11Z TIME FRAME. .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ SHORT TERM... LONG TERM...MJ AVIATION...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
348 AM CDT FRI JUN 19 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 347 AM CDT FRI JUN 19 2015 COMPLICATED FORECAST FOR TODAY. STRONG MCS CURRENTLY WORKING INTO WESTERN PORTIONS OF THE STATE AS OF 08Z....AND IS EXPECTED TO APPROACH THE WESTERN EDGE OF THE FORECAST AREA IN THE 13-14 Z TIME FRAME. WHAT IS INTERESTING...IS THAT THE AIR OVER THE FORECAST AREA IS COMPLETELY STABLE...BUT OFTEN TIMES...STRONG...WELL ESTABLISHED MCS CAN OUTRUN THE INSTABILITY. HRRR HAS BEEN VERY CONSISTENT WITH THIS...AND RAP IS NOW BEGINNING TO TREND IN THIS DIRECTION AS WELL. HAVE BEGUN TO TREND UPWARDS WITH POPS IN NORTHWEST FORECAST AREA IN CENTRAL SOUTH DAKOTA...BUT TRAIL POPS OFF TO THE EAST AS COMPLEX IS EXPECTED TO FALL APART AS IT WORKS DEEPER INTO THE STABLE AIR. RESIDUAL CLOUD COVER WILL REDUCE HEATING POTENTIAL FOR TODAY...AND HAVE CUT BACK HIGH TEMPERATURES ACROSS THE AREA...WITH GREATEST ADJUSTMENTS IN CENTRAL SOUTH DAKOTA. LOW LEVEL CONVERGENCE INCREASES THIS EVENING AS 35-45 KNOT LOW LEVEL JET DEVELOPS ACROSS THE CENTRAL PLAINS. WHILE STILL CAN/T RULE OUT AN ISOLATED STORM THROUGH THE EVENING HOURS...IT DOES APPEAR THAT THE CAP WILL BE STRONG ENOUGH AHEAD OF THE COLD FRONT AND ASSOCIATED MID LEVEL WAVE TO LIMIT CONVECTIVE POTENTIAL INITIALLY TO ISOLATED AT BEST. MUCH BETTER FOCUS FOR CONVECTION WILL BE ACROSS THE WESTERN REACHES OF THE STATE IN THE EVENING HOURS ALONG THE COLD FRONT. BASED ON SHEAR AND STORM MOTION...EXPECTING STORMS TO ORGANIZE INTO A MATURE MCS AND WORK INTO WESTERN PORTIONS OF THE FORECAST AREA 05-07Z. EXPECT STORMS TO BE ELEVATED...BUT WITH RELATIVELY DRY LAYER FROM 750 UP TO 300 MB...POTENTIAL FOR STRONG ORGANIZED MCS TO CREATE DAMAGING WINDS. 0-3 KM BULK SHEAR VECTORS NEAR 30-35 KNOTS ACROSS THE NORTHERN HALF OF THE FORECAST AREA....INDICATING DAMAGING WIND POTENTIAL ALONG AND NORTH OF I-90. AS STORMS WORK EAST OF I-29 AFTER 9Z...SEVERE WEATHER PARAMETERS DECREASE AND AM EXPECTING THE OVERALL INTENSITY TO DECREASE. WITH THAT SAID...STILL KEPT POPS IN THE CATEGORICAL RANGE ACROSS THE NORTH CLOSEST TO THE MID LEVEL WAVE...WITH LESSER CHANCES TO THE SOUTH ESPECIALLY SOUTH OF I-90 AS ONE GETS FURTHER AWAY FROM THE MID LEVEL WAVE AND THE UPPER JET. HAVE ADDED MENTION OF CHANCE OF LARGE HAIL AND DAMAGING WINDS TO WEATHER GRIDS...BUT WAS LESS CONFIDENT EAST OF I-29 AND DECREASED TO SLIGHT CHANCE ACROSS SOUTHWEST MINNESOTA WHERE SEVERE PARAMETERS AND SPC OUTLOOK DECREASE. HAVE COOLED LOWS SLIGHTLY ACROSS THE NORTH WHERE CONVECTION SEEMS LIKELY...AND LEFT TEMPERATURES SOUTH OF I-90 QUITE MILD IN THE UPPER 60S WHERE WIDESPREAD RAIN CHANCES ARE. WITH 0-2 KM VGP AND 0-3 KM EHI SUGGESTING SUPERCELLS...WILL KEEP MENTION OF LARGE HAIL AND DAMAGING WINDS IN THE HWO. HAVE ALSO MENTIONED IN THE GRIDS...WITH LESSER CHANCES OF WIDESPREAD SEVERE EAST OF I-29. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 347 AM CDT FRI JUN 19 2015 ON SATURDAY...THE CONVECTIVE COMPLEX SHOULD BE RAPIDLY EXITING OUR EASTERN ZONES IN THE MORNING. FURTHERMORE...THE WIND SHIFT TO THE NORTH AND NORTHWEST IS FORECAST TO MOVE ACROSS THE FORECAST AREA FAIRLY EARLY IN THE DAY WHICH SHOULD BUILD STORMS AWAY FROM OUR LOCATION IN THE AFTERNOON. WITH GOOD MIXING POTENTIAL AND SOME DRY AIR ADVECTION...HIGHS STILL LOOK WARM WITH WIDESPREAD 80S. CURRENTLY HAVE 89 AT SIOUX CITY BUT WOULD NOT BE SURPRISED IF THEY HIT 90 OR THE LOWER 90S IF THE MID AND UPPER CLOUD COVER EXITS QUICKLY ENOUGH BY MIDDAY. HIGH PRESSURE DOMINATES SATURDAY NIGHT...HELPING TO GIVE LIGHT WINDS AND WHAT SHOULD BE A DRY NIGHT. THEN ON SUNDAY...THE VARIOUS MODELS INCLUDING THE GFS...ECMWF AND NAM SHOW A WEAK SHORT WAVE IMPACTING THE FORECAST AREA...ESPECIALLY FOR LOCATIONS WEST OF I 29 AND NORTH OF I 90 IN OUR SOUTH DAKOTA ZONES. LOW LEVEL MOISTURE IS A BIT LACKING AFTER THE WIND SHIFT ON SATURDAY...BUT PLENTY OF MID LEVEL MOISTURE EXISTS WITH SOME DECENT LAPSE RATES BETWEEN 700 AND 500MB. THEREFORE CHANCE POPS ARE WARRANTED IN THE AFOREMENTIONED AREA WITH LESS CHANCES ELSEWHERE. ON SUNDAY NIGHT...SUNDAYS MID LEVEL SHORT WAVE WEAKENS IN OUR EATERN ZONES AS IT MOVES EASTWARD...REPLACED BY A STRONG SHORT WAVE RAPIDLY MOVING SOUTHEASTWARD ACROSS NORTH DAKOTA AND THE NORTHERN HALF OF MINNESOTA. MOST OF THE DYNAMICS REMAINS NORTH OF THE FORECAST AREA...SO THEREFORE ONLY CHANCE POPS ARE WARRANTED WITH THE HIGHEST POPS ALONG THE HIGHWAY 14 CORRIDOR IN OUR NORTHERN ZONES. LOWS STILL LOOK MILD...ABOUT 60 TO 65 DEGREES WITH THE WINDS CHANGING TO THE NORTH BEHIND THE SHORT WAVE PASSAGE LATE AT NIGHT. CONFIDENCE IS RATHER LOW IN THE EXTENDED IN TERMS OF WHEN AND WHERE THUNDERSTORM CHANCES ARE. IN GENERAL...BOTH THE GFS AND ECMWF ARE SHOWING AN UPPER RIDGE BUILDING ACROSS THE SOUTHERN HALF OF THE UNITED STATES WITH A BRISK QUASI ZONAL FLOW THROUGHOUT THE NORTHERN HALF. THIS TYPE OF PATTERN SHOULD GIVE MILD TEMPERATURES THROUGHOUT THE FORECAST...WITH HIGHS IN THE UPPER 70S TO MID 80S BASED ON THE LATEST 850MB TEMPERATURES OFF OF THE LATEST ECMWF AND GFS. LOWS ARE PRIMARILY IN THE LOWER AND MID 60S...BUT IF WE GET LIGHT WINDS COUPLED WITH CLEAR SKIES...WOULD NOT BE SURPRISED IF LOWS ERROR ON THE COOL SIDE OF SUPERBLEND LOWS HERE AND THERE. DUE TO THE DIFFERENCE BETWEEN THE VARIOUS MODELS WITH SPECIFIC SHORT WAVE TIMING MOVING ACROSS THE FAST UPPER FLOW...PIN POINTING RAIN CHANCES IS REAL PROBLEMATIC. AT THIS TIME...THERE DOES NOT LOOK TO BE A WIDESPREAD RAIN EVENT. THE ONE EXCEPTION TO THIS WHERE THERE IS SOME AGREEMENT IS IN NORTHWEST IOWA AND EXTREME NORTHEAST NEBRASKA LATE TUESDAY NIGHT AND WEDNESDAY MORNING. HOWEVER...BOTH MODELS LOOK LIKE THEY DEVELOP A CONVECTIVELY INDUCED SHORT WAVE...THEREFORE THE SHORT WAVE IN THAT AREA MAY BE A RESPONSE TO CONVECTIVE FEEDBACK. VERY DIFFICULT TO TELL THIS FAR OUT. THERE IS AN 850MB BOUNDARY CLOSE TO NORTHWEST IOWA...AT LEAST EXTENDING THROUGH THE SOUTHERN PORTION OF NORTHWEST IA. SO ITS WORTH WATCHING BUT HIGH POPS ARE NOT WARRANTED YET AT THIS TIME. ANOTHER WEAK COLD FRONT MOVES THROUGH LATER WEDNESDAY NIGHT AND THURSDAY MORNING...BUT AT THIS TIME THE FRONTAL PASSAGE DOES NOT LOOK TO HAVE A LOT OF SHOWER OR STORM ACTIVITY WITH IT. ONE THING OF INTEREST IS THE LONGER RANGE STILL SHOWS THE UPPER RIDGE MIGRATING AND BUILDING ACROSS THE WESTERN UNITED STATES BEYOND THE EXTENDED PERIOD. THAT WOULD PUT THE NORTHERN PLAINS IN A SHORT NORTHWEST FLOW ALOFT FOR THIS TIME OF YEAR. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1027 PM CDT THU JUN 18 2015 VFR CONDITIONS EXPECTED TO CONTINUE INTO FRIDAY MORNING. MCS ACTIVITY SLOW TO DEVELOP UPSTREAM...AND EVEN IF IT DOES...IT WILL STRUGGLE TO REACH MID-SOUTH DAKOTA BY DAYBREAK. ONLY EXPECTING A BIT OF AN INCREASE IN MID-LVL CLOUDS INTO THE MORNING. VFR CONDITIONS WITH BREEZY SOUTHERLY WINDS WILL PREVAIL FRIDAY...WITH SKIES CLEARING OUT EARLY FRIDAY EVENING. WHILE JUST AT THE EDGE OF THE CURRENT TAF PERIOD...WATCH OUT FOR STRONG CONVECTION AROUND 06Z SATURDAY. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ SHORT TERM... LONG TERM...MJ AVIATION...DUX
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
905 PM CDT SAT JUN 20 2015 .DISCUSSION...WATER VAPOR SATELLITE TRENDS/00Z UPPER AIR ANALYSIS INDICATES AN UPPER LEVEL RIDGE PRESENT OVER THE LOWER MISSISSIPPI VALLEY WHILE A MESOSCALE CONVECTIVE SYSTEM /MCS/ HAS DEVELOPED OVER SOUTHEAST IOWA/NORTHEAST MISSOURI. ISOLATED SHOWERS AND THUNDERSTORMS OVER THE PAST COUPLE OF HOURS HAVE DIMINISHED WITH THE LOSS OF DAYTIME INSTABILITY AND THE ONLY REMNANTS IS AN ISOLATED RAIN SHOWER OVER SOUTHERN HAYWOOD AND MADISON COUNTIES IN TENNESSEE. LATEST HRRR AND 00Z WRF INDICATE ANY ADDITIONAL SHOWER/THUNDERSTORM POTENTIAL WILL REMAIN MINIMAL AT BEST. WILL MAKE SOME MINOR ADJUSTMENTS TO FORECAST TO ACCOUNT FOR LATEST TRENDS. OTHERWISE...FORECAST OVERALL IS IN GREAT SHAPE. UPDATED GRIDS WILL BE AVAILABLE SHORTLY. CJC && .PREV DISCUSSION... /ISSUED 616 PM CDT SAT JUN 20 2015/ UPDATE...AVIATION DISCUSSION. PREV DISCUSSION... /ISSUED 252 PM CDT SAT JUN 20 2015/ DISCUSSION... HEAT AND HUMIDITY WILL DOMINATE THE FIRST HALF OF THE FORECAST PERIOD AS AN UPPER RIDGE OF HIGH PRESSURE GRADUALLY BUILDS INTO THE AREA OVER THE NEXT COUPLE OF DAYS. CURRENTLY...DIURNAL SHOWERS AND THUNDERSTORMS ARE POPPING UP ACROSS PORTIONS OF EASTERN ARKANSAS AND NORTHWEST MISSISSIPPI. TEMPERATURES HAVE WARMED INTO THE UPPER 80S TO LOWER 90S THUS FAR TODAY. CURRENT HEAT INDEX READING IN MEMPHIS IS AROUND 101-102 DEGREES. THE DIURNAL CONVECTION SHOULD DIE OFF AROUND 7 PM. CIRRUS CURRENTLY OVER TEXAS WILL SPREAD OVER THE CWA THIS SHOULD KEEP LOW TEMPERATURES UP COMPARED TO LAST NIGHT. READINGS WILL BE IN THE MID TO UPPER 70S. EXPECT CONDITIONS TO BE WARMER ON SUNDAY THUS HEAT INDICES COULD REACH 105 DEGREES IN A FEW LOCATIONS. A HEAT ADVISORY MAY BECOME NECESSARY. THE HEAT WILL BUILD DURING THE EARLY TO MIDDLE PART OF NEXT WEEK AS THE RIDGE MOVES INTO THE AREA. MODELS ARE WAVERING ON HOW STRONG THE RIDGE WILL BE THUS ISOLATED DIURNAL CONVECTION COULD OCCUR ON ABOUT EACH DAY BUT NOT ENOUGH AGREEMENT AMONG MODELS TO PUT ANY MENTION IN FORECAST YET. BY WEDNESDAY...BETTER AGREEMENT OCCURS THUS HAVE ADDED IN MENTION OF SHOWERS AND THUNDERSTORMS. HIGHS WILL GENERALLY BE IN THE MID TO UPPER 90S. HEAT INDICES SHOULD HIT AROUND 105 DEGREES EACH DAY. BY THURSDAY...THE UPPER RIDGE BEGINS TO BREAK DOWN. CHANCES FOR SHOWERS AND THUNDERSTORMS WILL INCREASE FROM THURSDAY INTO EARLY NEXT WEEKEND AS A COLD FRONT MOVES INTO THE AREA. TEMPERATURES WILL RETURN TO NORMAL DURING THIS TIME PERIOD DUE TO CLOUD COVER AND CONVECTION. KRM && .AVIATION... 00Z TAFS VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. WINDS WILL BE S-SW BETWEEN 5-10 KT. && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1231 PM CDT SAT JUN 20 2015 .DISCUSSION... UPDATED FOR 18Z AVIATION DISCUSSION && .PREV DISCUSSION... /ISSUED 1104 AM CDT SAT JUN 20 2015/ UPDATE... REMNANTS OF BILL REMAIN OVER THE OHIO VALLEY THIS MORNING. OUTER CLOUD BANDS ASSOCIATED WITH BILL CONTINUE TO AFFECT PORTIONS OF NORTHWEST TENNESSEE BUT THESE SHOULD GRADUALLY DIMINISH AS THE DAY GOES ON. MEANWHILE...AN AREA OF CLOUDS ALSO STRETCHES FROM CHARLESTON MISSISSIPPI TO AMORY MISSISSIPPI. HRRR SHOWS SOME POP UP THUNDERSTORMS DEVELOPING THIS AFTERNOON NEAR THIS AREA OF CLOUDS. WILL CONTINUE WITH THE 20 POP. OTHERWISE...THE BUILDING HEAT WILL BE THE MAIN CONCERN OVER THE NEXT SEVERAL DAYS. EXPECT HIGHS TODAY TO GET INTO THE LOWER 90S. UPDATE TO REMOVE MORNING WORDING WILL BE OUT SHORTLY. KRM DISCUSSION... /ISSUED 427 AM CDT SAT JUN 20 2015/ IT WILL BE BACK TO THE SUMMER HEAT TODAY WILL LITTLE IF ANY RAIN FOR THE NEXT SEVERAL DAYS AS TROPICAL DEPRESSION BILL PUSHES AWAY FROM THE MIDSOUTH. EXCESSIVE HEAT IS FORECAST TO DEVELOP SUNDAY INTO THE UPCOMING WORK WEEK...BUT THE GOOD NEWS IS THAT MODELS HAVE BEEN CONSISTENT IN SHOWING THE EXCESSIVE HEAT WILL BE RELATIVELY SHORT LIVED THIS TIME AROUND WITH A CHANCE OF SHOWERS AND THUNDERSTORMS TOWARD THE END OF THE WORK WEEK AND SOMEWHAT COOLER TEMPERATURES SPREADING INTO THE AREA FROM THE NORTHWEST NEXT WEEKEND. EARLY THIS MORNING...TROPICAL DEPRESSION BILL WAS CENTERED ALONG THE IN / KY BORDER AND WAS MOVING EAST-NORTHEASTWARD. ACROSS THE MIDSOUTH...ONLY A FEW LINGERING SHOWERS WERE NOTED IN THE EXTREME SOUTHERN PORTIONS OF NORTH MS. CLOUDS WERE CLEARING FROM THE WEST. SOUTHWEST WINDS IN THE WAKE OF BILL ARE FORECAST TO PUSH HOT AIR INTO THE REGION TODAY. HIGH TEMPERATURES WILL BE MOSTLY IN THE LOWER 90S EXCEPT UPPER 80S TOWARD PARIS TN. AFTERNOON HEAT INDEX READINGS ARE FORECAST TO CLIMB TO BETWEEN 100 AND 103 DEGREES FROM PORTIONS OF NORTHEAST AND EAST CENTRAL AR INTO SOUTHWEST TN AROUND MEMPHIS...AND MUCH OF NORTH MS. LINGERING CLOUDS MAINLY ALONG THE TN RIVER VALLEY WILL CONTINUE TO DECREASE THIS MORNING LEAVING MOSTLY TO PARTLY SUNNY SKIES ACROSS THE MIDSOUTH. MODELS INDICATE THE POSSIBILITY OF ISOLATED SHOWERS AND THUNDERSTORMS OCCURRING WITH DAYTIME HEATING AND LINGERING MOISTURE TODAY ACROSS PORTIONS OF NORTH MS...INDICATED A 20 PERCENT POP FOR THIS AREA TODAY. UPPER LEVEL RIDGING WILL BEGIN TO STRENGTHEN ACROSS THE MIDSOUTH SUNDAY WITH A SOUTHWEST LOW LEVEL FLOW PUSHING EVEN HOTTER AIR INTO THE AREA. AFTERNOON HEAT INDEX READINGS MAY REACH 105 DEGREES ESPECIALLY FROM EAST CENTRAL AR INTO NORTHWEST MS WHERE A HEAT ADVISORY MAY BE NEEDED IN LATER FORECASTS. WILL NEED TO SEE HOW MUCH IF ANY AFTERNOON DEW POINTS MIX OUT THIS AFTERNOON TO GET A BETTER HANDLE ON WHERE THE HEAT ADVISORY WILL BE NEEDED SUNDAY IF ANYWHERE. ANY CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE LESS THAN MENTIONABLE LEVELS. MONDAY LOOKS TO BE A VERY HOT DAY. STRONG HIGH PRESSURE ALOFT WILL BUILD OVER THE REGION FROM THE WEST WITH MOSTLY SUNNY SKIES. HIGH TEMPERATURES WILL CLIMB INTO THE MIDDLE AND UPPER 90S. HEAT INDEX READINGS ARE FORECAST TO CLIMB TO NEAR OR ABOVE 105 DEGREES ACROSS MUCH OF THE AREA. A HEAT ADVISORY WILL PROBABLY BE NEEDED. LITTLE CHANGE IN THE HOT AND MOSTLY RAIN FREE WEATHER IS SEEN INTO THURSDAY. SMALL CHANCES FOR AFTERNOON THUNDERSTORMS ARE POSSIBLE ACROSS PORTIONS OF THE AREA WEDNESDAY AND THURSDAY BUT CONFIDENCE IS LOW. MODELS INDICATE THE UPPER LEVEL RIDGE WILL BREAK DOWN ACROSS THE MIDSOUTH THURSDAY NIGHT INTO FRIDAY. NORTHWEST FLOW ALOFT WILL STRENGTHEN ACROSS THE REGION LEADING TO A CHANCE OF SHOWERS AND THUNDERSTORMS LATE IN THE WORK WEEK OR EARLY NEXT WEEKEND. MODELS DIFFER ON HOW THIS WILL EVOLVE WITH THE POSSIBILITY OF A MESOSCALE CONVECTIVE SYSTEM AFFECTING THE REGION. JCL && .AVIATION... 18Z TAFS VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. AN ISOLATED THUNDERSTORM COULD POP UP INVOF KTUP THIS AFTERNOON...BUT CONFIDENCE IS TOO LOW TO MENTION AT THIS TIME. WINDS WILL BE S-SW BETWEEN 10-15 MPH THIS AFTERNOON...DIMINISHING THIS EVENING. SJM && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1104 AM CDT SAT JUN 20 2015 .UPDATE... REMNANTS OF BILL REMAIN OVER THE OHIO VALLEY THIS MORNING. OUTER CLOUD BANDS ASSOCIATED WITH BILL CONTINUE TO AFFECT PORTIONS OF NORTHWEST TENNESSEE BUT THESE SHOULD GRADUALLY DIMINISH AS THE DAY GOES ON. MEANWHILE...AN AREA OF CLOUDS ALSO STRETCHES FROM CHARLESTON MISSISSIPPI TO AMORY MISSISSIPPI. HRRR SHOWS SOME POP UP THUNDERSTORMS DEVELOPING THIS AFTERNOON NEAR THIS AREA OF CLOUDS. WILL CONTINUE WITH THE 20 POP. OTHERWISE...THE BUILDING HEAT WILL BE THE MAIN CONCERN OVER THE NEXT SEVERAL DAYS. EXPECT HIGHS TODAY TO GET INTO THE LOWER 90S. UPDATE TO REMOVE MORNING WORDING WILL BE OUT SHORTLY. KRM && .DISCUSSION... /ISSUED 427 AM CDT SAT JUN 20 2015/ IT WILL BE BACK TO THE SUMMER HEAT TODAY WILL LITTLE IF ANY RAIN FOR THE NEXT SEVERAL DAYS AS TROPICAL DEPRESSION BILL PUSHES AWAY FROM THE MIDSOUTH. EXCESSIVE HEAT IS FORECAST TO DEVELOP SUNDAY INTO THE UPCOMING WORK WEEK...BUT THE GOOD NEWS IS THAT MODELS HAVE BEEN CONSISTENT IN SHOWING THE EXCESSIVE HEAT WILL BE RELATIVELY SHORT LIVED THIS TIME AROUND WITH A CHANCE OF SHOWERS AND THUNDERSTORMS TOWARD THE END OF THE WORK WEEK AND SOMEWHAT COOLER TEMPERATURES SPREADING INTO THE AREA FROM THE NORTHWEST NEXT WEEKEND. EARLY THIS MORNING...TROPICAL DEPRESSION BILL WAS CENTERED ALONG THE IN / KY BORDER AND WAS MOVING EAST-NORTHEASTWARD. ACROSS THE MIDSOUTH...ONLY A FEW LINGERING SHOWERS WERE NOTED IN THE EXTREME SOUTHERN PORTIONS OF NORTH MS. CLOUDS WERE CLEARING FROM THE WEST. SOUTHWEST WINDS IN THE WAKE OF BILL ARE FORECAST TO PUSH HOT AIR INTO THE REGION TODAY. HIGH TEMPERATURES WILL BE MOSTLY IN THE LOWER 90S EXCEPT UPPER 80S TOWARD PARIS TN. AFTERNOON HEAT INDEX READINGS ARE FORECAST TO CLIMB TO BETWEEN 100 AND 103 DEGREES FROM PORTIONS OF NORTHEAST AND EAST CENTRAL AR INTO SOUTHWEST TN AROUND MEMPHIS...AND MUCH OF NORTH MS. LINGERING CLOUDS MAINLY ALONG THE TN RIVER VALLEY WILL CONTINUE TO DECREASE THIS MORNING LEAVING MOSTLY TO PARTLY SUNNY SKIES ACROSS THE MIDSOUTH. MODELS INDICATE THE POSSIBILITY OF ISOLATED SHOWERS AND THUNDERSTORMS OCCURRING WITH DAYTIME HEATING AND LINGERING MOISTURE TODAY ACROSS PORTIONS OF NORTH MS...INDICATED A 20 PERCENT POP FOR THIS AREA TODAY. UPPER LEVEL RIDGING WILL BEGIN TO STRENGTHEN ACROSS THE MIDSOUTH SUNDAY WITH A SOUTHWEST LOW LEVEL FLOW PUSHING EVEN HOTTER AIR INTO THE AREA. AFTERNOON HEAT INDEX READINGS MAY REACH 105 DEGREES ESPECIALLY FROM EAST CENTRAL AR INTO NORTHWEST MS WHERE A HEAT ADVISORY MAY BE NEEDED IN LATER FORECASTS. WILL NEED TO SEE HOW MUCH IF ANY AFTERNOON DEW POINTS MIX OUT THIS AFTERNOON TO GET A BETTER HANDLE ON WHERE THE HEAT ADVISORY WILL BE NEEDED SUNDAY IF ANYWHERE. ANY CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE LESS THAN MENTIONABLE LEVELS. MONDAY LOOKS TO BE A VERY HOT DAY. STRONG HIGH PRESSURE ALOFT WILL BUILD OVER THE REGION FROM THE WEST WITH MOSTLY SUNNY SKIES. HIGH TEMPERATURES WILL CLIMB INTO THE MIDDLE AND UPPER 90S. HEAT INDEX READINGS ARE FORECAST TO CLIMB TO NEAR OR ABOVE 105 DEGREES ACROSS MUCH OF THE AREA. A HEAT ADVISORY WILL PROBABLY BE NEEDED. LITTLE CHANGE IN THE HOT AND MOSTLY RAIN FREE WEATHER IS SEEN INTO THURSDAY. SMALL CHANCES FOR AFTERNOON THUNDERSTORMS ARE POSSIBLE ACROSS PORTIONS OF THE AREA WEDNESDAY AND THURSDAY BUT CONFIDENCE IS LOW. MODELS INDICATE THE UPPER LEVEL RIDGE WILL BREAK DOWN ACROSS THE MIDSOUTH THURSDAY NIGHT INTO FRIDAY. NORTHWEST FLOW ALOFT WILL STRENGTHEN ACROSS THE REGION LEADING TO A CHANCE OF SHOWERS AND THUNDERSTORMS LATE IN THE WORK WEEK OR EARLY NEXT WEEKEND. MODELS DIFFER ON HOW THIS WILL EVOLVE WITH THE POSSIBILITY OF A MESOSCALE CONVECTIVE SYSTEM AFFECTING THE REGION. JCL && .AVIATION... 12Z TAFS VFR CONDITIONS EXPECTED AT ALL TERMINALS OVER THE NEXT 24 HOURS. THERE IS A SMALL CHANCE THAT AN ISOLATED THUNDERSTORM COULD IMPACT TUP THIS AFTERNOON...BUT CONFIDENCE IS TOO LOW TO INCLUDE IN TAF AT THIS TIME. WINDS WILL BE SOUTH-SOUTHWESTERLY BETWEEN 10-15 MPH TODAY. TVT && && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1123 PM CDT FRI JUN 19 2015 .UPDATE...AVIATION DISCUSSION. && .PREV DISCUSSION... /ISSUED 855 PM CDT FRI JUN 19 2015/ DISCUSSION...WATER VAPOR SATELLITE/WSR-88D VAD WIND PROFILES THIS EVENING CENTER THE REMNANTS OF BILL JUST NORTHEAST OF METROPOLIS ILLINOIS. SHORTWAVE TROUGHS ROTATING AROUND THE REMNANTS ARE PRODUCING BANDS OF RAIN SHOWERS AND ISOLATED THUNDERSTORMS ACROSS THE MID SOUTH WITH THE BEST COVERAGE AS OF 8 PM CDT OVER NORTH MISSISSIPPI. LATEST HRRR AND THE 00Z WRF MODELS INDICATE BILL WILL MOVE EAST OVERNIGHT WITH THE BEST CHANCES FOR ANY ADDITIONAL SHOWER ISOLATED THUNDERSTORM DEVELOPMENT OCCURRING PREDOMINANTLY ACROSS PORTIONS OF NORTHEAST MISSISSIPPI AND WEST TENNESSEE NEAR THE TENNESSEE RIVER. WILL UPDATE POPS AND ALL OTHER ELEMENTS AS NEEDED TO REFLECT CURRENT TRENDS. UPDATED GRIDS WILL BE AVAILABLE SHORTLY. CJC PREV DISCUSSION... /ISSUED 633 PM CDT FRI JUN 19 2015/ UPDATE...AVIATION DISCUSSION. PREV DISCUSSION... /ISSUED 323 PM CDT FRI JUN 19 2015/ DISCUSSION... REMNANTS OF BILL CONTINUE TO AFFECT THE MIDSOUTH THIS AFTERNOON. BANDS OF SHOWERS AND THUNDERSTORMS CONTINUE TO ROTATE AROUND THE CENTER WHICH IS NOW LOCATED NEAR POPLAR BLUFF. WINDS HAVE BEEN GUSTY WITH SPEEDS NEAR 30 MPH AT TIMES. RAINFALL AMOUNTS HAVE NOT BEEN AS HIGH AS PREVIOUSLY THOUGHT THUS WILL GO AHEAD AND CANCEL THE FLASH FLOOD WATCH. THERE WILL STILL BE THE CHANCE FOR LOCALIZED FLASH FLOODING IF THUNDERSTORMS TRAIN FOR A PERIOD OF TIME OVER A PARTICULAR LOCATION BUT THAT COULD OCCUR ANYWHERE IN THE CWA. IN ADDITION...ISOLATED TORNADOES WILL STILL BE POSSIBLE WITHIN SOME OF THE THUNDERSTORMS MOVING THROUGH WEST TENNESSEE AND NORTHEAST MISSISSIPPI. THE CENTER OF BILL WILL CONTINUE TO PUSH OFF TO THE NORTHEAST TONIGHT. BY SATURDAY MORNING...LINGERING SHOWERS AND THUNDERSTORMS WILL LIKELY ONLY REMAIN ACROSS WEST TENNESSEE NEAR THE TENNESSEE RIVER AND POSSIBLY NORTHEAST MISSISSIPPI. ONCE BILL DEPARTS...ALL ATTENTION WILL TURN TO THE HEAT AS AN UPPER RIDGE WILL BUILD OVER THE AREA BY THE LATTER PART OF THE WEEKEND INTO MUCH OF NEXT WEEK. HIGHS WILL REACH INTO MID TO UPPER 90S. THE COMBINATION OF THE HOT TEMPERATURES AND HIGH HUMIDITY WILL PRODUCE HEAT INDICES 105 DEGREES OR GREATER POSSIBLY AS EARLY AS SUNDAY. THESE CONDITIONS MAY CONTINUE THROUGH AT LEAST THURSDAY. ISOLATED DIURNAL THUNDERSTORMS MAY OCCUR DURING THE AFTERNOON AND EARLY EVENING HOURS ON WEDNESDAY AND THURSDAY...OTHERWISE EXPECT DRY CONDITIONS TO OCCUR. BY THE END OF THE WEEK...MODELS ARE SHOWING THE RIDGE BREAKING DOWN ALLOWING FOR A FRONT TO APPROACH THE AREA. BETTER CHANCES FOR SHOWERS AND THUNDERSTORMS MAY OCCUR IF THIS HAPPENS BUT SOMETIMES THE RIDGE ENDS UP HANGING ON LONGER. WILL HAVE TO WAIT AND SEE. KRM && .AVIATION...06Z TAF CYCLE RAIN/TS HAS ENDED AT MKL...JBR AND MEM. TUP WILL LIKELY SEE MVFR VIS DUE TO RAINFALL OVER THE NEXT HOUR OF SO. EXPECT MAINLY VFR CONDS OVERNIGHT WITH SOME LOW CLOUDS AT KMKL AND KTUP TOWARD MORNING. VFR CONDS RETURN AREAWIDE SATURDAY MORNING AS THE REMNANTS OF BILL DEPART. WINDS WILL BE STRONG ACROSS MUCH OF THE AREA THIS AFTERNOON WITH GUSTS UP TO 30 KTS AT KMEM...KJBR AND KMKL. WINDS WILL DIMINISH THIS EVENING. STRATUS IS EXPECTED TO DEVELOP AROUND SUNRISE...MOST LIKELY NEAR MKL AND TUP RESULTING IN MVFR CIGS...BUT SHOULD MIX OUT BY MID MORNING. NO ADDITIONAL RAINFALL IS EXPECTED TOMORROW. VFR CONDITIONS ARE EXPECTED. && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
855 PM CDT FRI JUN 19 2015 .DISCUSSION...WATER VAPOR SATELLITE/WSR-88D VAD WIND PROFILES THIS EVENING CENTER THE REMNANTS OF BILL JUST NORTHEAST OF METROPOLIS ILLINOIS. SHORTWAVE TROUGHS ROTATING AROUND THE REMNANTS ARE PRODUCING BANDS OF RAIN SHOWERS AND ISOLATED THUNDERSTORMS ACROSS THE MID SOUTH WITH THE BEST COVERAGE AS OF 8 PM CDT OVER NORTH MISSISSIPPI. LATEST HRRR AND THE 00Z WRF MODELS INDICATE BILL WILL MOVE EAST OVERNIGHT WITH THE BEST CHANCES FOR ANY ADDITIONAL SHOWER ISOLATED THUNDERSTORM DEVELOPMENT OCCURRING PREDOMINANTLY ACROSS PORTIONS OF NORTHEAST MISSISSIPPI AND WEST TENNESSEE NEAR THE TENNESSEE RIVER. WILL UPDATE POPS AND ALL OTHER ELEMENTS AS NEEDED TO REFLECT CURRENT TRENDS. UPDATED GRIDS WILL BE AVAILABLE SHORTLY. CJC && .PREV DISCUSSION... /ISSUED 633 PM CDT FRI JUN 19 2015/ UPDATE...AVIATION DISCUSSION. PREV DISCUSSION... /ISSUED 323 PM CDT FRI JUN 19 2015/ DISCUSSION... REMNANTS OF BILL CONTINUE TO AFFECT THE MIDSOUTH THIS AFTERNOON. BANDS OF SHOWERS AND THUNDERSTORMS CONTINUE TO ROTATE AROUND THE CENTER WHICH IS NOW LOCATED NEAR POPLAR BLUFF. WINDS HAVE BEEN GUSTY WITH SPEEDS NEAR 30 MPH AT TIMES. RAINFALL AMOUNTS HAVE NOT BEEN AS HIGH AS PREVIOUSLY THOUGHT THUS WILL GO AHEAD AND CANCEL THE FLASH FLOOD WATCH. THERE WILL STILL BE THE CHANCE FOR LOCALIZED FLASH FLOODING IF THUNDERSTORMS TRAIN FOR A PERIOD OF TIME OVER A PARTICULAR LOCATION BUT THAT COULD OCCUR ANYWHERE IN THE CWA. IN ADDITION...ISOLATED TORNADOES WILL STILL BE POSSIBLE WITHIN SOME OF THE THUNDERSTORMS MOVING THROUGH WEST TENNESSEE AND NORTHEAST MISSISSIPPI. THE CENTER OF BILL WILL CONTINUE TO PUSH OFF TO THE NORTHEAST TONIGHT. BY SATURDAY MORNING...LINGERING SHOWERS AND THUNDERSTORMS WILL LIKELY ONLY REMAIN ACROSS WEST TENNESSEE NEAR THE TENNESSEE RIVER AND POSSIBLY NORTHEAST MISSISSIPPI. ONCE BILL DEPARTS...ALL ATTENTION WILL TURN TO THE HEAT AS AN UPPER RIDGE WILL BUILD OVER THE AREA BY THE LATTER PART OF THE WEEKEND INTO MUCH OF NEXT WEEK. HIGHS WILL REACH INTO MID TO UPPER 90S. THE COMBINATION OF THE HOT TEMPERATURES AND HIGH HUMIDITY WILL PRODUCE HEAT INDICES 105 DEGREES OR GREATER POSSIBLY AS EARLY AS SUNDAY. THESE CONDITIONS MAY CONTINUE THROUGH AT LEAST THURSDAY. ISOLATED DIURNAL THUNDERSTORMS MAY OCCUR DURING THE AFTERNOON AND EARLY EVENING HOURS ON WEDNESDAY AND THURSDAY...OTHERWISE EXPECT DRY CONDITIONS TO OCCUR. BY THE END OF THE WEEK...MODELS ARE SHOWING THE RIDGE BREAKING DOWN ALLOWING FOR A FRONT TO APPROACH THE AREA. BETTER CHANCES FOR SHOWERS AND THUNDERSTORMS MAY OCCUR IF THIS HAPPENS BUT SOMETIMES THE RIDGE ENDS UP HANGING ON LONGER. WILL HAVE TO WAIT AND SEE. KRM && .AVIATION...00Z TAF CYCLE REMNANTS OF BILL TRACKING JUST NORTH OF THE AREA. NUMEROUS SHRAS AND SCATTERED TSRAS WILL MOVE ACROSS THE MIDSOUTH THROUGH EARLY THIS EVENING. EXPECT MAINLY VFR CONDS WITH MVFR...ISOLD IFR...CONDS IN THE BANDS OF SHRAS/TSRAS. PRECIPITATION WILL START TO TAPER OFF THIS EVENING. EXPECT MAINLY VFR CONDS OVERNIGHT WITH SOME LOW CLOUDS POSSIBLE AT KMKL AND KTUP TOWARD MORNING. VFR CONDS RETURN AREAWIDE SATURDAY MORNING AS THE REMNANTS OF BILL DEPART. WINDS WILL BE STRONG ACROSS MUCH OF THE AREA THIS AFTERNOON WITH GUSTS UP TO 30 KTS AT KMEM...KJBR AND KMKL. WINDS WILL DIMINISH THIS EVENING. STRATUS IS EXPECTED TO DEVELOP AROUND SUNRISE...MOST LIKELY NEAR MKL AND TUP RESULTING IN MVFR CIGS...BUT SHOULD MIX OUT BY MID MORNING. && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1253 PM CDT FRI JUN 19 2015 .DISCUSSION... UPDATED FOR 18Z AVIATION DISCUSSION && .PREV DISCUSSION... /ISSUED 1029 AM CDT FRI JUN 19 2015/ UPDATE... REMNANTS OF BILL CONTINUE TO AFFECT NORTHEAST ARKANSAS THIS MORNING. IN ADDITION...NEW SHOWER DEVELOPMENT HAS BEGUN ALONG AND JUST EAST OF THE MISSISSIPPI RIVER. LATEST HRRR SHOWS THIS AREA REALLY BLOSSOMING OVER THE NEXT 2-4 HOURS WHILE THE BAND OF RAIN OVER NORTHEAST ARKANSAS MAY SHOW SIGNS OF DISSIPATING. MAY NEED TO ADJUST POPS THIS AFTERNOON BUT FOR NOW CURRENT FORECAST HAS A GOOD HANDLE. KRM DISCUSSION.... /ISSUED 438 AM CDT FRI JUN 19 2015/ THE REMNANTS OF TROPICAL DEPRESSION BILL WILL AFFECT THE MIDSOUTH TODAY AND TONIGHT BRINGING THE THREAT OF FLASH FLOODING AND SEVERE THUNDERSTORMS. EARLY THIS MORNING...BILL REMAINED A TROPICAL DEPRESSION AND WAS TRACKING EAST-NORTHEASTWARD THROUGH NORTHWEST ARKANSAS. A BROKEN BAND OF SHOWERS HAD SPREAD INTO THE MIDSOUTH AHEAD OF THIS SYSTEM AND WAS INCREASING IN COVERAGE AND INTENSITY. BILL IS EXPECTED TO TRANSITION TO AN EXTRATROPICAL LOW PRESSURE SYSTEM TODAY AS IT CONTINUE EAST-NORTHEASTWARD. THE LOW WILL TRACK ALONG THE AR AND MO BORDER MOVING INTO SOUTHEAST MISSOURI BY LATE AFTERNOON. BREEZY SOUTHWEST WINDS WILL DEVELOP ACROSS THE MIDSOUTH IN ASSOCIATION WITH THIS SYSTEM. ATTM...THINK WINDS WILL REMAIN BELOW WIND ADVISORY CRITERIA...BUT SOMETHING TO KEEP AN EYE ON. TROPICAL MOISTURE WITH VERY HIGH PRECIPITABLE WATER VALUES BETWEEN 2.4 AND 2.5 INCHES ARE FORECAST TO SPREAD INTO THE MIDSOUTH TODAY. MODELS INDICATE THAT THE WIDESPREAD HEAVIEST RAINFALL WILL TRACK CLOSE TO OR JUST NORTH OF THE NORTHERN REACHES OF OUR FORECAST AREA...NEAR THE THE TRACK OF THE LOW PRESSURE CENTER. KEPT THE FLASH FLOOD WATCH GOING FOR TODAY AND TONIGHT FOR PORTIONS OF NORTHEAST AR AND THE MISSOURI BOOTHEEL GENERALLY ALONG AND NORTH OF A LINE FROM WALNUT RIDGE AR TO CARUTHERSVILLE MO. FLASH FLOOD VALUES ARE FAIRLY HIGH ACROSS THE MIDSOUTH...BUT RAINFALL MAY BE HEAVY ENOUGH IN A SHORT TIME TO CAUSE SOME FLASH FLOODING IN THE WATCH AREA. ELSEWHERE ACROSS THE MIDSOUTH...LOCALLY HEAVY DOWNPOURS WITH LOCALIZED FLASH FLOODING MAY OCCUR AS SPIRAL BANDS OF SHOWERS AND THUNDERSTORMS EXPAND WITH DAYTIME HEATING. THERE WILL ALSO BE A SEVERE WEATHER THREAT TODAY AND TONIGHT ACROSS THE MIDSOUTH. A FEW EMBEDDED SUPERCELLS ARE POSSIBLE THAT COULD RESULT IN ISOLATED TORNADOES AND DAMAGING WINDS. OF THE VARIOUS MODELS...THE NAM INDICATES THE GREATEST DIRECTIONAL SHEAR ACROSS THE REGION WITH THE POSSIBILITY OF ROTATING SUPERCELLS. HOWEVER...THE SEVERE WEATHER THREAT WILL DEPEND ON HOW MUCH INSTABILITY CAN BE REALIZED. THE REMNANTS OF BILL WILL MOVE TO NEAR THE KY / IN BORDER BY 12Z SATURDAY. MODELS INDICATE THAT LINGERING SHOWERS AND THUNDERSTORMS WILL MOVE EAST OF THE AREA BY NOON SATURDAY. CLOUDS WILL DECREASE AS THE LOW PRESSURE SYSTEM PUSHES FURTHER TO THE EAST. SOUTHWEST LOW LEVEL WINDS ARE FORECAST TO PUSH HOT AIR INTO THE REGION WITH THE NAM BEING THE MOST ROBUST. STRONG HIGH PRESSURE IN THE UPPER ATMOSPHERE WILL GRADUALLY BUILD OVER THE MIDSOUTH FROM THE WEST BEGINNING SUNDAY. THIS WILL LEAD TO A MOSTLY RAIN FREE AND PERIOD OF EXCESSIVE HEAT. HEAT INDEX READINGS WILL PROBABLY CLIMB TO ABOVE 105 DEGREES WITH A HEAT ADVISORY BECOMING NECESSARY FOR MUCH OF THE MIDSOUTH. DIFFICULT TO DETERMINE HOW MUCH DRY WILL WORK ITS WAY DOWN TO THE SURFACE FROM ALOFT DURING THE AFTERNOONS...BUT USUALLY FOLLOWING TROPICAL SYSTEMS THE LOWER LEVELS REMAIN QUITE MOIST. MODELS INDICATE THE UPPER LEVEL RIDGE WEAKENING BY THE END OF THE WORK WEEK WITH A CHANCE OF SHOWERS AND THUNDERSTORMS RETURNING. THIS IS A LONG WAYS OFF AND REMAINS TO BE SEEN. JCL && .AVIATION... 18Z TAF CYCLE REMNANTS OF BILL TRACKING JUST NORTH OF THE AREA. NUMEROUS SHRAS AND SCATTERED TSRAS WILL MOVE ACROSS THE MIDSOUTH THROUGH EARLY THIS EVENING. EXPECT MAINLY VFR CONDS WITH MVFR...ISOLD IFR...CONDS IN THE BANDS OF SHRAS/TSRAS. PRECIPITATION WILL START TO TAPER OFF THIS EVENING. EXPECT MAINLY VFR CONDS OVERNIGHT WITH SOME LOW CLOUDS POSSIBLE AT KMKL AND KTUP TOWARD MORNING. VFR CONDS RETURN AREAWIDE SATURDAY MORNING AS THE REMNANTS OF BILL DEPART. WINDS WILL BE STRONG ACROSS MUCH OF THE AREA THIS AFTERNOON WITH GUSTS UP TO 30 KTS AT KMEM...KJBR AND KMKL. WINDS WILL DIMINISH THIS EVENING. SJM && .MEG WATCHES/WARNINGS/ADVISORIES... AR...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR CLAY-GREENE- LAWRENCE-RANDOLPH. MO...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR DUNKLIN-PEMISCOT. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1029 AM CDT FRI JUN 19 2015 .UPDATE... REMNANTS OF BILL CONTINUE TO AFFECT NORTHEAST ARKANSAS THIS MORNING. IN ADDITION...NEW SHOWER DEVELOPMENT HAS BEGUN ALONG AND JUST EAST OF THE MISSISSIPPI RIVER. LATEST HRRR SHOWS THIS AREA REALLY BLOSSOMING OVER THE NEXT 2-4 HOURS WHILE THE BAND OF RAIN OVER NORTHEAST ARKANSAS MAY SHOW SIGNS OF DISSIPATING. MAY NEED TO ADJUST POPS THIS AFTERNOON BUT FOR NOW CURRENT FORECAST HAS A GOOD HANDLE. KRM && .DISCUSSION.... /ISSUED 438 AM CDT FRI JUN 19 2015/ THE REMNANTS OF TROPICAL DEPRESSION BILL WILL AFFECT THE MIDSOUTH TODAY AND TONIGHT BRINGING THE THREAT OF FLASH FLOODING AND SEVERE THUNDERSTORMS. EARLY THIS MORNING...BILL REMAINED A TROPICAL DEPRESSION AND WAS TRACKING EAST-NORTHEASTWARD THROUGH NORTHWEST ARKANSAS. A BROKEN BAND OF SHOWERS HAD SPREAD INTO THE MIDSOUTH AHEAD OF THIS SYSTEM AND WAS INCREASING IN COVERAGE AND INTENSITY. BILL IS EXPECTED TO TRANSITION TO AN EXTRATROPICAL LOW PRESSURE SYSTEM TODAY AS IT CONTINUE EAST-NORTHEASTWARD. THE LOW WILL TRACK ALONG THE AR AND MO BORDER MOVING INTO SOUTHEAST MISSOURI BY LATE AFTERNOON. BREEZY SOUTHWEST WINDS WILL DEVELOP ACROSS THE MIDSOUTH IN ASSOCIATION WITH THIS SYSTEM. ATTM...THINK WINDS WILL REMAIN BELOW WIND ADVISORY CRITERIA...BUT SOMETHING TO KEEP AN EYE ON. TROPICAL MOISTURE WITH VERY HIGH PRECIPITABLE WATER VALUES BETWEEN 2.4 AND 2.5 INCHES ARE FORECAST TO SPREAD INTO THE MIDSOUTH TODAY. MODELS INDICATE THAT THE WIDESPREAD HEAVIEST RAINFALL WILL TRACK CLOSE TO OR JUST NORTH OF THE NORTHERN REACHES OF OUR FORECAST AREA...NEAR THE THE TRACK OF THE LOW PRESSURE CENTER. KEPT THE FLASH FLOOD WATCH GOING FOR TODAY AND TONIGHT FOR PORTIONS OF NORTHEAST AR AND THE MISSOURI BOOTHEEL GENERALLY ALONG AND NORTH OF A LINE FROM WALNUT RIDGE AR TO CARUTHERSVILLE MO. FLASH FLOOD VALUES ARE FAIRLY HIGH ACROSS THE MIDSOUTH...BUT RAINFALL MAY BE HEAVY ENOUGH IN A SHORT TIME TO CAUSE SOME FLASH FLOODING IN THE WATCH AREA. ELSEWHERE ACROSS THE MIDSOUTH...LOCALLY HEAVY DOWNPOURS WITH LOCALIZED FLASH FLOODING MAY OCCUR AS SPIRAL BANDS OF SHOWERS AND THUNDERSTORMS EXPAND WITH DAYTIME HEATING. THERE WILL ALSO BE A SEVERE WEATHER THREAT TODAY AND TONIGHT ACROSS THE MIDSOUTH. A FEW EMBEDDED SUPERCELLS ARE POSSIBLE THAT COULD RESULT IN ISOLATED TORNADOES AND DAMAGING WINDS. OF THE VARIOUS MODELS...THE NAM INDICATES THE GREATEST DIRECTIONAL SHEAR ACROSS THE REGION WITH THE POSSIBILITY OF ROTATING SUPERCELLS. HOWEVER...THE SEVERE WEATHER THREAT WILL DEPEND ON HOW MUCH INSTABILITY CAN BE REALIZED. THE REMNANTS OF BILL WILL MOVE TO NEAR THE KY / IN BORDER BY 12Z SATURDAY. MODELS INDICATE THAT LINGERING SHOWERS AND THUNDERSTORMS WILL MOVE EAST OF THE AREA BY NOON SATURDAY. CLOUDS WILL DECREASE AS THE LOW PRESSURE SYSTEM PUSHES FURTHER TO THE EAST. SOUTHWEST LOW LEVEL WINDS ARE FORECAST TO PUSH HOT AIR INTO THE REGION WITH THE NAM BEING THE MOST ROBUST. STRONG HIGH PRESSURE IN THE UPPER ATMOSPHERE WILL GRADUALLY BUILD OVER THE MIDSOUTH FROM THE WEST BEGINNING SUNDAY. THIS WILL LEAD TO A MOSTLY RAIN FREE AND PERIOD OF EXCESSIVE HEAT. HEAT INDEX READINGS WILL PROBABLY CLIMB TO ABOVE 105 DEGREES WITH A HEAT ADVISORY BECOMING NECESSARY FOR MUCH OF THE MIDSOUTH. DIFFICULT TO DETERMINE HOW MUCH DRY WILL WORK ITS WAY DOWN TO THE SURFACE FROM ALOFT DURING THE AFTERNOONS...BUT USUALLY FOLLOWING TROPICAL SYSTEMS THE LOWER LEVELS REMAIN QUITE MOIST. MODELS INDICATE THE UPPER LEVEL RIDGE WEAKENING BY THE END OF THE WORK WEEK WITH A CHANCE OF SHOWERS AND THUNDERSTORMS RETURNING. THIS IS A LONG WAYS OFF AND REMAINS TO BE SEEN. JCL && .AVIATION... 12Z TAF CYCLE VFR CONDITIONS CURRENTLY AT ALL TERMINALS WITH SHOWERS INCREASING IN COVERAGE THROUGH THE MORNING ASSOCIATED WITH THE REMNANTS OF BILL. WINDS HAVE ALSO INCREASED IN ASSOCIATED WITH THE STRONGER LOW LEVEL WIND FIELDS IN CLOSER PROXIMITY TO THE CENTER OF CIRCULATION. WINDS WILL GAIN A MORE SOUTHWESTERLY COMPONENT THROUGH THE AFTERNOON REMAINING BETWEEN 15 AND 25 KTS. VCTS IS ALSO POSSIBLE AFTER 18Z AS SOME DAYTIME HEATING IS REALIZED. EXPECT SHOWERS TO PERSIST THROUGH THE OVERNIGHT...BEGINNING TO DECREASE TOWARD 09Z SATURDAY. TVT && && .MEG WATCHES/WARNINGS/ADVISORIES... AR...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR CLAY-GREENE- LAWRENCE-RANDOLPH. MO...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR DUNKLIN-PEMISCOT. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
950 PM CDT SAT JUN 20 2015 .UPDATE... MCS THAT FORMED JUST SOUTH OF THE RIO GRANDE ALONG THE GULF OF COAST OF MEXICO LATE THIS MORNING AND MOVED ACROSS SOUTH CENTRAL TEXAS THIS AFTERNOON INTO EARLY EVENING WAS DISSIPATING OVER NORTH CENTRAL TEXAS LEAVING SOME LIGHT RAIN AND ISOLATED SHOWERS OVER SOUTH CENTRAL TEXAS. SATELLITE AND UPPER AIR OBSERVATIONS SHOW A MID AND UPPER LEVEL TROUGH OVER CENTRAL TEXAS TO THE RIO GRANDE. MODELS INDICATE THIS FEATURE TO LINGER INTO AT LEAST SUNDAY. THE SAME DATA SHOWS PWS RANGE FROM 1.5 INCHES OVER THE LOWER PECOS VALLEY TO 2.1 INCHES NEAR THE COASTAL PLAINS. EXPECT REDEVELOPMENT OF SHOWERS AND THUNDERSTORMS OVERNIGHT DUE TO UPWARD FORCING OF THE MOIST AIRMASS AND HAVE MAINTAINED CURRENT POPS. THE OUTFLOW FROM THE MCS COOLED OFF TEMPERATURES TO NEAR OR SLIGHTLY BELOW FORECASTED LOWS AND HAVE RE-ESTABLISHED TRENDS TO THE TEMPERATURES AND GONE 1 TO 3 DEGREES COOLER ON THE LOWS. REMAINDER OF SOUTH CENTRAL TEXAS FORECAST IS ON TRACK. SUNDAY LOOKS TO BE SIMILAR TO TODAY. && .PREV DISCUSSION... /ISSUED 652 PM CDT SAT JUN 20 2015/ AVIATION... /00Z TAF UPDATE/ A SQUALL WILL PULL NORTH OF THE AUS VCNTY IN THE NEXT 15 MINUTES OR SO. AFTERWARDS...CONVECTION SHOULD BE MOSTLY BETWEEN THE I-35 TAF SITES AND DRT. LIGHT SHRA OVER THE SAT/SSF AREA COULD BE PRODUCING BRIEF STRATUS FRACTUS...BUT WILL NOT SHOW THIS IN TAFS DESPITE A BKN IFR CIG AT SSF AT 2339Z. MORE IFR CIGS SHOULD DEVELOP LATE TONIGHT AFTER A MOSTLY STABLE REST OF THE EVENING IN THE WAKE OF THE SQUALLS. WILL STICK WITH PERSISTENCE AND CONSISTENCY WITH EARLIER TAFS ON THE TIMING OF THE CIG CATEGORY CHANGES. BASED ON THE HRRR AND OTHER FINE RESOLUTION MODELS...CONVECTION IS EXPECTED TO PICK UP EARLY IN THE DAY AGAIN SUNDAY...BUT WILL EXPECT LESS COVERAGE AND NOT MENTION THE POTENTIAL FOR THUNDER OR TIMING AT THIS POINT. PREV DISCUSSION... /ISSUED 229 PM CDT SAT JUN 20 2015/ SHORT TERM (TONIGHT THROUGH SUNDAY NIGHT)... ONGOING CONVECTION IN THE CWA AND APPROACHING CONVECTION FROM SOUTH TEXAS WILL BRING SCATTERED COVERAGE OF STORMS LATE THIS AFTERNOON AND EVENING ACROSS THE ENTIRE AREA. THE FOCUS AFTER MIDNIGHT WILL SHIFT TOWARD THE RIO GRANDE PLAINS AND WINTER GARDEN AREA...CLOSER TO THE UPPER LEVEL TROUGH AXIS AND HIGHEST PW AIR. THERE IS ALSO MENTION OF LOCALLY HEAVY RAIN IN THIS AREA...BUT THAT SHOULD BE SPOTTY AND PROBABLY UNDER 3 INCHES FOR ANY SINGLE POINT...HENCE A FLASH FLOOD WATCH WILL NOT BE ISSUED. CONDITIONS DO NOT CHANGE MUCH THROUGH SUNDAY NIGHT EXCEPT A SLIGHT REDUCTION IN PW TO 1.8-2.0 INCHES AND THE BEGINNING OF THE TROUGH WEAKENING. THUS...SIMILAR CHANCE POPS AND LOW TO MODERATE QPF. LONG TERM (MONDAY THROUGH SATURDAY)... THE LONGER TERM REGIONAL AND GLOBAL MODELS ARE IN GOOD AGREEMENT OVER THE NEXT WEEK WITH THE SUBTROPICAL RIDGE BECOMING ESTABLISHED ACROSS THE SOUTHERN U.S....EFFECTIVELY REMOVING THE TROUGH CURRENTLY IN PLACE. THIS SHOULD ALLOW FOR DRYING AND WARMING SUCH THAT ONLY ISOLATED CONVECTION ALONG THE SEA BREEZE AND SERRANIAS DEL BURRO IN MEXICO OCCURS...WHILE TEMPERATURES RETURN TO NEAR NORMAL LOWER 90S. THE FORECAST UNDERCUTS MAX TEMPS 1-3 F DUE TO THE EXPECTATION OF NEAR-SURFACE MOISTURE HAVING TO EVAPORATE OFF. THE SUBTROPICAL RIDGE SPLITS IN TWO AS THE LONGWAVE PATTERN FORCES A LARGE WESTERN U.S. RIDGE AND OHIO RIVER VALLEY TROUGH...AND BERMUDA RIDGE...WITH A BREAK IN THE RIDGES EXTENDING FROM THE TROUGH INTO EAST TEXAS. THIS SHOULD OPEN UP THE GULF FOR A MOIST AIR SURGE NEXT WEEKEND INTO THE FOLLOWING WEEK...AND THUS INCREASED POPS A LITTLE MORE INLAND FROM THE COAST. KEPT TEMPERATURES NEAR OR JUST A LITTLE BELOW NORMAL THROUGH THE EXTENDED PERIOD. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 72 89 75 91 74 / 40 30 20 10 - AUSTIN BERGSTROM INTL AIRPORT 73 88 74 91 73 / 40 30 20 10 - NEW BRAUNFELS MUNI AIRPORT 73 89 75 91 74 / 40 30 20 20 - BURNET MUNI AIRPORT 71 87 74 90 72 / 40 30 20 10 - DEL RIO INTL AIRPORT 74 89 75 91 75 / 50 30 30 20 10 GEORGETOWN MUNI AIRPORT 72 88 75 91 73 / 40 30 20 10 - HONDO MUNI AIRPORT 73 87 75 90 73 / 50 40 30 20 10 SAN MARCOS MUNI AIRPORT 73 88 75 91 74 / 40 30 20 20 - LA GRANGE - FAYETTE REGIONAL 74 89 76 91 74 / 40 30 20 20 - SAN ANTONIO INTL AIRPORT 75 88 77 91 75 / 40 30 20 20 10 STINSON MUNI AIRPORT 74 88 76 91 75 / 40 40 20 20 10 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...OAKS SYNOPTIC/GRIDS...04
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
652 PM CDT SAT JUN 20 2015 .AVIATION... /00Z TAF UPDATE/ A SQUALL WILL PULL NORTH OF THE AUS VCNTY IN THE NEXT 15 MINUTES OR SO. AFTERWARDS...CONVECTION SHOULD BE MOSTLY BETWEEN THE I-35 TAF SITES AND DRT. LIGHT SHRA OVER THE SAT/SSF AREA COULD BE PRODUCING BRIEF STRATUS FRACTUS...BUT WILL NOT SHOW THIS IN TAFS DESPITE A BKN IFR CIG AT SSF AT 2339Z. MORE IFR CIGS SHOULD DEVELOP LATE TONIGHT AFTER A MOSTLY STABLE REST OF THE EVENING IN THE WAKE OF THE SQUALLS. WILL STICK WITH PERSISTENCE AND CONSISTENCY WITH EARLIER TAFS ON THE TIMING OF THE CIG CATEGORY CHANGES. BASED ON THE HRRR AND OTHER FINE RESOLUTION MODELS...CONVECTION IS EXPECTED TO PICK UP EARLY IN THE DAY AGAIN SUNDAY...BUT WILL EXPECT LESS COVERAGE AND NOT MENTION THE POTENTIAL FOR THUNDER OR TIMING AT THIS POINT. && .PREV DISCUSSION... /ISSUED 229 PM CDT SAT JUN 20 2015/ SHORT TERM (TONIGHT THROUGH SUNDAY NIGHT)... ONGOING CONVECTION IN THE CWA AND APPROACHING CONVECTION FROM SOUTH TEXAS WILL BRING SCATTERED COVERAGE OF STORMS LATE THIS AFTERNOON AND EVENING ACROSS THE ENTIRE AREA. THE FOCUS AFTER MIDNIGHT WILL SHIFT TOWARD THE RIO GRANDE PLAINS AND WINTER GARDEN AREA...CLOSER TO THE UPPER LEVEL TROUGH AXIS AND HIGHEST PW AIR. THERE IS ALSO MENTION OF LOCALLY HEAVY RAIN IN THIS AREA...BUT THAT SHOULD BE SPOTTY AND PROBABLY UNDER 3 INCHES FOR ANY SINGLE POINT...HENCE A FLASH FLOOD WATCH WILL NOT BE ISSUED. CONDITIONS DO NOT CHANGE MUCH THROUGH SUNDAY NIGHT EXCEPT A SLIGHT REDUCTION IN PW TO 1.8-2.0 INCHES AND THE BEGINNING OF THE TROUGH WEAKENING. THUS...SIMILAR CHANCE POPS AND LOW TO MODERATE QPF. LONG TERM (MONDAY THROUGH SATURDAY)... THE LONGER TERM REGIONAL AND GLOBAL MODELS ARE IN GOOD AGREEMENT OVER THE NEXT WEEK WITH THE SUBTROPICAL RIDGE BECOMING ESTABLISHED ACROSS THE SOUTHERN U.S....EFFECTIVELY REMOVING THE TROUGH CURRENTLY IN PLACE. THIS SHOULD ALLOW FOR DRYING AND WARMING SUCH THAT ONLY ISOLATED CONVECTION ALONG THE SEA BREEZE AND SERRANIAS DEL BURRO IN MEXICO OCCURS...WHILE TEMPERATURES RETURN TO NEAR NORMAL LOWER 90S. THE FORECAST UNDERCUTS MAX TEMPS 1-3 F DUE TO THE EXPECTATION OF NEAR-SURFACE MOISTURE HAVING TO EVAPORATE OFF. THE SUBTROPICAL RIDGE SPLITS IN TWO AS THE LONGWAVE PATTERN FORCES A LARGE WESTERN U.S. RIDGE AND OHIO RIVER VALLEY TROUGH...AND BERMUDA RIDGE...WITH A BREAK IN THE RIDGES EXTENDING FROM THE TROUGH INTO EAST TEXAS. THIS SHOULD OPEN UP THE GULF FOR A MOIST AIR SURGE NEXT WEEKEND INTO THE FOLLOWING WEEK...AND THUS INCREASED POPS A LITTLE MORE INLAND FROM THE COAST. KEPT TEMPERATURES NEAR OR JUST A LITTLE BELOW NORMAL THROUGH THE EXTENDED PERIOD. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 74 89 75 91 74 / 40 30 20 10 - AUSTIN BERGSTROM INTL AIRPORT 74 88 74 91 73 / 40 30 20 10 - NEW BRAUNFELS MUNI AIRPORT 74 89 75 91 74 / 40 30 20 20 - BURNET MUNI AIRPORT 73 87 74 90 72 / 40 30 20 10 - DEL RIO INTL AIRPORT 74 89 75 91 75 / 50 30 30 20 10 GEORGETOWN MUNI AIRPORT 74 88 75 91 73 / 40 30 20 10 - HONDO MUNI AIRPORT 73 87 75 90 73 / 50 40 30 20 10 SAN MARCOS MUNI AIRPORT 74 88 75 91 74 / 40 30 20 20 - LA GRANGE - FAYETTE REGIONAL 76 89 76 91 74 / 40 30 20 20 - SAN ANTONIO INTL AIRPORT 75 88 77 91 75 / 40 30 20 20 10 STINSON MUNI AIRPORT 75 88 76 91 75 / 40 40 20 20 10 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...OAKS SYNOPTIC/GRIDS...04 PUBLIC SERVICE/DATA COLLECTION...TREADWAY
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1245 PM CDT FRI JUN 19 2015 .AVIATION... ISOLATED TO SCATTERED THUNDERSTORMS WILL BE POSSIBLE AGAIN THIS EVENING AT ANY TAF SITE. HOWEVER...CONFIDENCE IS VERY LOW WITH REGARD TO LOCATIONS OF ANY STORMS DUE TO EXPECTED LIMITED COVERAGE. && .PREV DISCUSSION... /ISSUED 626 AM CDT FRI JUN 19 2015/ AVIATION... -SHRA/-TSRA THAT WERE IMPACTING KLBB AND KPVW HAVE DIMINISHED. WINDS HAVE THEREFORE BECOME VARIABLE BUT WILL EVENTUALLY SETTLE TO THE SOUTHEAST LATER THIS MORNING...BEFORE VEERING TO THE SOUTH SOUTHWEST BY THIS AFTERNOON. COMPUTER MODELS HINT AT THE POTENTIAL FOR ISOLATED -TSRA TO DEVELOP LATE THIS AFTERNOON/EARLY THIS EVENING...THOUGH THE EXACT LOCATION IS UNCERTAIN AND THE MODELS COULD BE OVERDOING THIS CONVECTION. AS SUCH...CONFIDENCE IS NOT HIGH ENOUGH TO INSERT A PRECIP MENTION FOR THIS TAF CYCLE...AND OPT TO WAIT AND SEE HOW TRENDS GO LATER THIS AFTERNOON. WILL OF COURSE AMEND AS NECESSARY. PREV DISCUSSION... /ISSUED 315 AM CDT FRI JUN 19 2015/ SHORT TERM... AS TROPICAL DEPRESSION BILL CONTINUED TO PUSH ENEWRD ACROSS NRN AR EARLY THIS MORNING...BROAD UA RIDGING ACROSS THE SWRN CONUS HAS GRADUALLY EXPANDED EWRD TO NEAR REGION. THUS...THE WRN PERIPHERY WAS ACROSS THE SOUTHERN PLAINS. AS SUCH...N-NW FLOW ALOFT PREVAILED WHICH HAS RESULTED IN A WANING MCS HAVING THE CAPABILITY TO SAG SWRD ACROSS THE TX/NM STATE LINE PER 07Z WATER VAPOR SATELLITE IMAGERY. FURTHERMORE...RADAR ANALYSIS SHOWED THE DEVELOPMENT OF ISOLATED TO SCATTERED STORMS IN THE WAKE OF AN OUTFLOW BOUNDARY TRANSLATING SE ACROSS THE SOUTH PLAINS AND TOWARDS LOCALES OFF THE CAPROCK. ALTHOUGH THIS SCATTERED CONVECTION IS MOVING...THE RATHER MOIST ENVIRONMENT /DEWPOINTS IN THE 50S AND 60S/ HAS ALLOWED THIS ACTIVITY TO BRIEFLY DROP MODERATE RAINFALL. A TTU MESONSET SITE LOCATED AT REESE CENTER RECORDED A TOTAL OF 0.53 INCHES THAT OCCURRED WITH ONE HOUR...AND AT THE NWS OFFICE...AROUND 0.70 INCHES FELL. KEEPING IN MIND THAT MODEL SOLUTIONS HAVE DONE A POOR JOB IN EVEN SHOWING THIS MORNING/S CONVECTION...WILL ADJUST POPS IN THE PRE-FIRST PERIOD INTO THE SLIGHT CHANCE CATEGORY OFF THE CAPROCK...GIVEN STORMS HAVE POPPED UP ACROSS BRISCOE COUNTY. THIS CONVECTION SHOULD DEMISE IN THE NEXT SEVERAL HOURS...AND THE HRRR HINTS AT FOG DEVELOPING AND REMAINING SOUTH OF THE CWA. WILL KEEP AN EYE OUT TO SEE IF THIS INDEEDS OCCUR. TODAY...THE WRN PERIPHERY OF THE UA RIDGE IS EXPECTED TO EXPAND EVER SO SLIGHTLY EWRD ACROSS THE REGION AND ONE WOULD EXPECT DECREASING CHANCES FOR PRECIP. HOWEVER...THE NAM AND LONG TERM SOLUTIONS HINT AT STORMS FIRING UP ONCE AGAIN ACROSS THE MOUNTAINOUS TERRAIN OF NERN NM AND SERN CO THIS AFTN/EVENING. W-SW MEAN FLOW RAISES EYEBROWS FOR THIS ACTIVITY TO POSSIBLY SHIFT TOWARDS THE CWA ONCE AGAIN TONIGHT...HOWEVER THE MEAN FLOW IS RATHER WEAK /AOA 10 KTS/ WHICH COULD MITIGATE THIS FROM OCCURRING. WHAT IS INTERESTING TO NOTE IS THAT HIGH-RES SOLUTIONS SUCH AS THE HRRR AND THE TTU WRF EXHIBITED ISOLATED-SCATTERED STORMS DEVELOPING THIS AFTN JUST ABOUT ANYWHERE ACROSS THE FA...WITH THE CAP EXPECTING TO BREAK BY LATE AFTN. THIS IS A POSSIBILITY ESPECIALLY SINCE THE UA RIDGE IS NOT QUITE DIRECTLY OVERHEAD...HOWEVER MODELS PERFORMING POORLY AS OF LATE DOES NOT BODE WELL FOR CONFIDENCE. WILL OPT TO RAISE POPS TO 10- 12 PERCENT WITH HIGHEST POPS NOTED ACROSS THE NWRN ZONES THIS AFTN...AND KEEPING POPS AROUND 12 PERCENT ACROSS THE NWRN ZONES ONCE AGAIN FOR TONIGHT. WILL LET LATER SHIFTS SEE HOW RADAR TRENDS ARE SHAPING UP THIS AFTN AND EVENING AND WHETHER OR NOT POPS NEED TO BE RAISED TO MENTIONABLE LEVELS. IF STORMS DO INDEED DEVELOP...MUCAPE OF 2-2.5 KJ/KG MAY RAISE CONCERNS FOR THE POTENTIAL FOR STRONG STORMS...HOWEVER RATHER WEAK 0-6 KM BULK SHEAR /LESS THAN 20 KTS/ MAY KEEP STORM STRENGTH ON THE TAME SIDE. OTHERWISE...ANOTHER DAY OF SEASONAL WARMTH IS ON TAP /LOWER 90S/ FOLLOWED BY A MILD NIGHT /LOWER 60S ACROSS NW TO LOWER 70S FAR EAST/. LONG TERM... THE UPPER RIDGE OVER THE SWRN CONUS AND ADJACENT WATERS OFF THE COAST OF SRN AND BAJA CALIF WILL EXPAND EWD THROUGH THE WEEKEND RESULTING IN NEAR NORMAL TEMPERATURES AND FAIR BUT BREEZY WEATHER THROUGH AT LEAST THE FIRST HALF OF NEXT WEEK. A WWD-MOVING INVERTED UPPER TROUGH WILL MOVE ACROSS DEEP SOUTH TEXAS THIS WEEKEND AND ONTO THE MOUNTAINS OF NRN MEXICO TOWARD THE MIDDLE OF NEXT WEEK. AS MOISTURE FROM THIS SYSTEM SPREADS NWD INTO NEW MEXICO AND AS A LOW-AMPLITUDE UPPER TROUGH DEVELOPS OVER CALIF COULD SEE SOME PRECIP RETURN TO NEW MEXICO AND POSSIBLY THE SOUTH PLAINS AND PANHANDLE. CONFIDENCE OF THIS DEVELOPMENT BY DAYS 6 AND 7 OF THE FCST TOO LOW TO INSERT PRECIP MENTION JUST YET. UNTIL THEN WARM AND DRY WITH ONLY MINOR ADJUSTMENTS TO PREVIOUS FCST. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 64 92 63 91 / 10 0 0 0 TULIA 66 92 65 90 / 0 0 0 0 PLAINVIEW 65 91 65 89 / 0 0 0 0 LEVELLAND 65 92 66 90 / 0 0 0 0 LUBBOCK 66 92 68 89 / 0 0 0 0 DENVER CITY 63 92 64 90 / 0 0 0 0 BROWNFIELD 65 92 66 90 / 0 0 0 0 CHILDRESS 70 95 70 93 / 0 0 0 0 SPUR 68 93 67 90 / 0 0 0 0 ASPERMONT 70 94 70 92 / 0 0 0 10 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 01
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
626 AM CDT FRI JUN 19 2015 .AVIATION... -SHRA/-TSRA THAT WERE IMPACTING KLBB AND KPVW HAVE DIMINISHED. WINDS HAVE THEREFORE BECOME VARIABLE BUT WILL EVENTUALLY SETTLE TO THE SOUTHEAST LATER THIS MORNING...BEFORE VEERING TO THE SOUTH SOUTHWEST BY THIS AFTERNOON. COMPUTER MODELS HINT AT THE POTENTIAL FOR ISOLATED -TSRA TO DEVELOP LATE THIS AFTERNOON/EARLY THIS EVENING...THOUGH THE EXACT LOCATION IS UNCERTAIN AND THE MODELS COULD BE OVERDOING THIS CONVECTION. AS SUCH...CONFIDENCE IS NOT HIGH ENOUGH TO INSERT A PRECIP MENTION FOR THIS TAF CYCLE...AND OPT TO WAIT AND SEE HOW TRENDS GO LATER THIS AFTERNOON. WILL OF COURSE AMEND AS NECESSARY. && .PREV DISCUSSION... /ISSUED 315 AM CDT FRI JUN 19 2015/ SHORT TERM... AS TROPICAL DEPRESSION BILL CONTINUED TO PUSH ENEWRD ACROSS NRN AR EARLY THIS MORNING...BROAD UA RIDGING ACROSS THE SWRN CONUS HAS GRADUALLY EXPANDED EWRD TO NEAR REGION. THUS...THE WRN PERIPHERY WAS ACROSS THE SOUTHERN PLAINS. AS SUCH...N-NW FLOW ALOFT PREVAILED WHICH HAS RESULTED IN A WANING MCS HAVING THE CAPABILITY TO SAG SWRD ACROSS THE TX/NM STATE LINE PER 07Z WATER VAPOR SATELLITE IMAGERY. FURTHERMORE...RADAR ANALYSIS SHOWED THE DEVELOPMENT OF ISOLATED TO SCATTERED STORMS IN THE WAKE OF AN OUTFLOW BOUNDARY TRANSLATING SE ACROSS THE SOUTH PLAINS AND TOWARDS LOCALES OFF THE CAPROCK. ALTHOUGH THIS SCATTERED CONVECTION IS MOVING...THE RATHER MOIST ENVIRONMENT /DEWPOINTS IN THE 50S AND 60S/ HAS ALLOWED THIS ACTIVITY TO BRIEFLY DROP MODERATE RAINFALL. A TTU MESONSET SITE LOCATED AT REESE CENTER RECORDED A TOTAL OF 0.53 INCHES THAT OCCURRED WITH ONE HOUR...AND AT THE NWS OFFICE...AROUND 0.70 INCHES FELL. KEEPING IN MIND THAT MODEL SOLUTIONS HAVE DONE A POOR JOB IN EVEN SHOWING THIS MORNING/S CONVECTION...WILL ADJUST POPS IN THE PRE-FIRST PERIOD INTO THE SLIGHT CHANCE CATEGORY OFF THE CAPROCK...GIVEN STORMS HAVE POPPED UP ACROSS BRISCOE COUNTY. THIS CONVECTION SHOULD DEMISE IN THE NEXT SEVERAL HOURS...AND THE HRRR HINTS AT FOG DEVELOPING AND REMAINING SOUTH OF THE CWA. WILL KEEP AN EYE OUT TO SEE IF THIS INDEEDS OCCUR. TODAY...THE WRN PERIPHERY OF THE UA RIDGE IS EXPECTED TO EXPAND EVER SO SLIGHTLY EWRD ACROSS THE REGION AND ONE WOULD EXPECT DECREASING CHANCES FOR PRECIP. HOWEVER...THE NAM AND LONG TERM SOLUTIONS HINT AT STORMS FIRING UP ONCE AGAIN ACROSS THE MOUNTAINOUS TERRAIN OF NERN NM AND SERN CO THIS AFTN/EVENING. W-SW MEAN FLOW RAISES EYEBROWS FOR THIS ACTIVITY TO POSSIBLY SHIFT TOWARDS THE CWA ONCE AGAIN TONIGHT...HOWEVER THE MEAN FLOW IS RATHER WEAK /AOA 10 KTS/ WHICH COULD MITIGATE THIS FROM OCCURRING. WHAT IS INTERESTING TO NOTE IS THAT HIGH-RES SOLUTIONS SUCH AS THE HRRR AND THE TTU WRF EXHIBITED ISOLATED-SCATTERED STORMS DEVELOPING THIS AFTN JUST ABOUT ANYWHERE ACROSS THE FA...WITH THE CAP EXPECTING TO BREAK BY LATE AFTN. THIS IS A POSSIBILITY ESPECIALLY SINCE THE UA RIDGE IS NOT QUITE DIRECTLY OVERHEAD...HOWEVER MODELS PERFORMING POORLY AS OF LATE DOES NOT BODE WELL FOR CONFIDENCE. WILL OPT TO RAISE POPS TO 10- 12 PERCENT WITH HIGHEST POPS NOTED ACROSS THE NWRN ZONES THIS AFTN...AND KEEPING POPS AROUND 12 PERCENT ACROSS THE NWRN ZONES ONCE AGAIN FOR TONIGHT. WILL LET LATER SHIFTS SEE HOW RADAR TRENDS ARE SHAPING UP THIS AFTN AND EVENING AND WHETHER OR NOT POPS NEED TO BE RAISED TO MENTIONABLE LEVELS. IF STORMS DO INDEED DEVELOP...MUCAPE OF 2-2.5 KJ/KG MAY RAISE CONCERNS FOR THE POTENTIAL FOR STRONG STORMS...HOWEVER RATHER WEAK 0-6 KM BULK SHEAR /LESS THAN 20 KTS/ MAY KEEP STORM STRENGTH ON THE TAME SIDE. OTHERWISE...ANOTHER DAY OF SEASONAL WARMTH IS ON TAP /LOWER 90S/ FOLLOWED BY A MILD NIGHT /LOWER 60S ACROSS NW TO LOWER 70S FAR EAST/. LONG TERM... THE UPPER RIDGE OVER THE SWRN CONUS AND ADJACENT WATERS OFF THE COAST OF SRN AND BAJA CALIF WILL EXPAND EWD THROUGH THE WEEKEND RESULTING IN NEAR NORMAL TEMPERATURES AND FAIR BUT BREEZY WEATHER THROUGH AT LEAST THE FIRST HALF OF NEXT WEEK. A WWD-MOVING INVERTED UPPER TROUGH WILL MOVE ACROSS DEEP SOUTH TEXAS THIS WEEKEND AND ONTO THE MOUNTAINS OF NRN MEXICO TOWARD THE MIDDLE OF NEXT WEEK. AS MOISTURE FROM THIS SYSTEM SPREADS NWD INTO NEW MEXICO AND AS A LOW-AMPLITUDE UPPER TROUGH DEVELOPS OVER CALIF COULD SEE SOME PRECIP RETURN TO NEW MEXICO AND POSSIBLY THE SOUTH PLAINS AND PANHANDLE. CONFIDENCE OF THIS DEVELOPMENT BY DAYS 6 AND 7 OF THE FCST TOO LOW TO INSERT PRECIP MENTION JUST YET. UNTIL THEN WARM AND DRY WITH ONLY MINOR ADJUSTMENTS TO PREVIOUS FCST. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 90 64 92 63 / 10 10 0 0 TULIA 91 66 92 65 / 10 0 0 0 PLAINVIEW 91 65 91 65 / 10 0 0 0 LEVELLAND 93 65 92 66 / 10 0 0 0 LUBBOCK 93 66 92 68 / 10 0 0 0 DENVER CITY 91 63 92 64 / 10 0 0 0 BROWNFIELD 92 65 92 66 / 10 0 0 0 CHILDRESS 94 70 95 70 / 10 0 0 0 SPUR 94 68 93 67 / 10 0 0 0 ASPERMONT 95 70 94 70 / 10 0 0 0 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 29/7/29
AREA FORECAST DISCUSSION
NWS EL PASO TX/SANTA TERESA NM
406 AM MDT FRI JUN 19 2015 .SYNOPSIS... HIGH PRESSURE ALOFT WILL BRING HOT AND MOSTLY DRY WEATHER TO SOUTHERN NEW MEXICO AND WEST TEXAS TODAY THROUGH MONDAY. HOWEVER THERE WILL BE ENOUGH MOISTURE AND INSTABILITY IN THE ATMOSPHERE TO BRING A SLIGHT CHANCE OF THUNDERSTORMS TO THE BORDERLAND EACH DAY WITH MOST OF THE STORMS OCCURRING OVER THE HIGHER MOUNTAINS. AN UPPER LEVEL DISTURBANCE APPROACHING FROM THE EAST WILL GENERATE INCREASING SHOWER AND THUNDERSTORM ACTIVITY TUESDAY THROUGH NEXT THURSDAY. && .DISCUSSION... ANOTHER ACTIVE NIGHT FOR SOUTHERN NEW MEXICO AND WEST TEXAS WITH SHOWERS/THUNDERSTORMS PERSISTING INTO THE EARLY MORNING DESPITE ALL THE MODELS INCLUDING THE HRRR PREDICTING DRY WEATHER. LIKE LAST NIGHT THERE IS AS POSSIBLE POORLY ANALYZED UPPER WAVE MOVING AROUND THE RIDGE INTO EASTERN SECTIONS OF THE CWA FROM THE NORTH. THE WEST TO EAST ORIENTED UPPER RIDGE NOW EXTENDING INTO THE CWA WILL FURTHER EXPAND AND STRENGTHEN INTO THE WEEKEND WITH HIGH PRESSURE CENTER ALOFT LOCATED OVER NORTHERN NEW MEXICO BY LATE SUNDAY. ASSOCIATED SUBSIDENCE PLUS ABUNDANT SUNSHINE WILL SUPPORT HOT ABOVE NORMAL DAYTIME TEMPERATURES THROUGH MONDAY. WARM AIR ALOFT AND SUBSIDENCE WILL ALSO GREATLY INHIBIT CONVECTION ACROSS MOST AREAS DESPITE HOT AND MODERATELY MOIST CONDITIONS AT LOW LEVELS. THUS EXPECT MOST CONVECTION WILL BE LIMITED TO THE MOUNTAIN AREAS THROUGH MONDAY THOUGH VERY ISOLATED STORMS MAY DEVELOP OVER THE LOWER ELEVATIONS VIA HEATING PLUS OUTFLOW BOUNDARIES. MODELS HAVE REMAINED CONSISTENT AND IN AGREEMENT IN MOVING RATHER HIGH AMPLITUDE INVERTED TROUGH SLOWLY INTO WEST AND SOUTHERN NEW MEXICO TUESDAY THROUGH THURSDAY. TRAJECTORIES AROUND THE TROUGH WILL ADVECT ABUNDANT MOISTURE INTO THE CWA CAUSING PRECIPITABLE WATER TO RISE ABOVE AN INCH WITH THE AIR MASS BECOMING WEAKLY UNSTABLE. LIFTING AHEAD OF THE UPPER TROUGH SHOULD CONSEQUENTLY INDUCE MORE WIDESPREAD CONVECTION ACROSS THE AREA. IF MODELS PROVE CORRECT POTENTIAL FOR HEAVY RAINS AND FLOODING WILL INCREASE WEDNESDAY AND THURSDAY SO SITUATION SHOULD BE MONITORED LATER FORECAST PERIODS. && .AVIATION...19/12Z-20/12Z. ISOLATED AREAS OF MVFR CEILINGS AND VISIBILITIES IN SHOWERS AND THUNDERSTORMS...OTHERWISE VFR CONDITIONS MOST AREAS WITH AREAS OF CEILINGS ABOVE 10,000 FEET AGL. THUNDERSTORMS MAY PRODUCE WIND GUSTS TO 50 MPH WITH WINDS OTHERWISE HAVING SPEEDS AROUND 5 TO 15 MPH. && .FIRE WEATHER... HIGH PRESSURE ALOFT WILL BRING HOT AND MOSTLY DRY WEATHER TO SOUTHERN NEW MEXICO AND WEST TEXAS TODAY THROUGH MONDAY WITH TEMPERATURES REMAINING ABOVE NORMAL. HOWEVER THERE WILL BE ENOUGH MOISTURE AND INSTABILITY IN THE ATMOSPHERE TO BRING A SLIGHT CHANCE OF THUNDERSTORMS TO THE AREA EACH DAY WITH MOST OF THE STORMS OCCURRING OVER THE HIGHER MOUNTAINS. WINDS MAY GUST TO 50 MPH NEAR STORMS...OTHERWISE WIND SPEEDS WILL BE MOSTLY AROUND 5 TO 15 MPH. LOWEST AFTERNOON HUMIDITY WILL BE AROUND 5 TO 15 PERCENT LOWLANDS AND 20 TO 30 PERCENT MOUNTAINS TODAY THROUGH THE WEEKEND. AN UPPER LEVEL DISTURBANCE APPROACHING FROM THE EAST WILL GENERATE INCREASING SHOWER AND THUNDERSTORM ACTIVITY TUESDAY THROUGH NEXT THURSDAY. && .PRELIMINARY POINT TEMPS/POPS... EL PASO 100 75 102 76 / 10 10 0 0 SIERRA BLANCA 94 69 96 70 / 10 10 10 0 LAS CRUCES 98 69 101 70 / 10 10 0 0 ALAMOGORDO 96 68 99 69 / 10 10 0 0 CLOUDCROFT 77 50 79 53 / 30 30 20 10 TRUTH OR CONSEQUENCES 97 68 99 69 / 10 20 0 0 SILVER CITY 93 61 94 62 / 10 20 0 0 DEMING 99 65 101 66 / 10 10 0 0 LORDSBURG 99 67 100 67 / 10 10 0 0 WEST EL PASO METRO 99 76 102 76 / 10 10 0 0 DELL CITY 94 67 99 68 / 10 10 0 0 FORT HANCOCK 97 73 100 73 / 10 10 10 0 LOMA LINDA 94 67 98 69 / 10 10 0 0 FABENS 100 72 102 73 / 10 10 10 0 SANTA TERESA 99 71 101 71 / 10 10 0 0 WHITE SANDS HQ 96 70 100 71 / 10 10 0 0 JORNADA RANGE 97 66 100 67 / 10 10 0 0 HATCH 98 66 101 67 / 10 10 0 0 COLUMBUS 99 70 101 70 / 10 10 0 0 OROGRANDE 97 72 99 73 / 10 10 0 0 MAYHILL 83 54 88 56 / 30 30 20 10 MESCALERO 85 53 89 55 / 30 30 10 10 TIMBERON 83 51 87 54 / 30 30 10 0 WINSTON 91 57 96 60 / 20 20 0 0 HILLSBORO 97 63 101 64 / 10 20 0 0 SPACEPORT 98 66 100 67 / 10 10 0 0 LAKE ROBERTS 91 54 94 58 / 20 20 0 0 HURLEY 94 61 96 62 / 10 10 0 0 CLIFF 98 56 99 55 / 10 10 0 0 MULE CREEK 97 52 98 51 / 10 10 0 0 FAYWOOD 94 62 97 64 / 10 10 0 0 ANIMAS 100 68 101 67 / 10 10 0 0 HACHITA 100 67 101 66 / 10 10 0 0 ANTELOPE WELLS 99 66 100 65 / 10 10 0 0 CLOVERDALE 98 64 98 62 / 10 10 0 0 && .EPZ WATCHES/WARNINGS/ADVISORIES... NM...NONE. TX...NONE. && $$ 05 ROGASH
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
315 AM CDT FRI JUN 19 2015 .SHORT TERM... AS TROPICAL DEPRESSION BILL CONTINUED TO PUSH ENEWRD ACROSS NRN AR EARLY THIS MORNING...BROAD UA RIDGING ACROSS THE SWRN CONUS HAS GRADUALLY EXPANDED WRD TO NEAR REGION. THUS...THE WRN PERIPHERY WAS ACROSS THE SOUTHERN PLAINS. AS SUCH...N-NW FLOW ALOFT PREVAILED WHICH HAS RESULTED IN A WANING MCS HAVING THE CAPABILITY TO SAG SWRD ACROSS THE TX/NM STATE LINE PER 07Z WATER VAPOR SATELLITE IMAGERY. FURTHERMORE...RADAR ANALYSIS SHOWED THE DEVELOPMENT OF ISOLATED TO SCATTERED STORMS IN THE WAKE OF AN OUTFLOW BOUNDARY TRANSLATING SE ACROSS THE SOUTH PLAINS AND TOWARDS LOCALES OFF THE CAPROCK. ALTHOUGH THIS SCATTERED CONVECTION IS MOVING...THE RATHER MOIST ENVIRONMENT /DEWPOINTS IN THE 50S AND 60S/ HAS ALLOWED THIS ACTIVITY TO BRIEFLY DROP MODERATE RAINFALL. A TTU MESONSET SITE LOCATED AT REESE CENTER RECORDED A TOTAL OF 0.53 INCHES THAT OCCURRED WITH ONE HOUR...AND AT THE NWS OFFICE...AROUND 0.70 INCHES FELL. KEEPING IN MIND THAT MODEL SOLUTIONS HAVE DONE A POOR JOB IN EVEN SHOWING THIS MORNING/S CONVECTION...WILL ADJUST POPS IN THE PRE-FIRST PERIOD INTO THE SLIGHT CHANCE CATEGORY OFF THE CAPROCK...GIVEN STORMS HAVE POPPED UP ACROSS BRISCOE COUNTY. THIS CONVECTION SHOULD DEMISE IN THE NEXT SEVERAL HOURS...AND THE HRRR HINTS AT FOG DEVELOPING AND REMAINING SOUTH OF THE CWA. WILL KEEP AN EYE OUT TO SEE IF THIS INDEEDS OCCUR. TODAY...THE WRN PERIPHERY OF THE UA RIDGE IS EXPECTED TO EXPAND EVER SO SLIGHTLY WRD ACROSS THE REGION AND ONE WOULD EXPECT DECREASING CHANCES FOR PRECIP. HOWEVER...THE NAM AND LONG TERM SOLUTIONS HINT AT STORMS FIRING UP ONCE AGAIN ACROSS THE MOUNTAINOUS TERRAIN OF NERN NM AND SERN CO THIS AFTN/EVENING. W-SW MEAN FLOW RAISES EYEBROWS FOR THIS ACTIVITY TO POSSIBLY SHIFT TOWARDS THE CWA ONCE AGAIN TONIGHT...HOWEVER THE MEAN FLOW IS RATHER WEAK /AOA 10 KTS/ WHICH COULD MITIGATE THIS FROM OCCURRING. WHAT IS INTERESTING TO NOTE IS THAT HIGH-RES SOLUTIONS SUCH AS THE HRRR AND THE TTU WRF EXHIBITED ISOLATED-SCATTERED STORMS DEVELOPING THIS AFTN JUST ABOUT ANYWHERE ACROSS THE FA...WITH THE CAP EXPECTING TO BREAK BY LATE AFTN. THIS IS A POSSIBILITY ESPECIALLY SINCE THE UA RIDGE IS NOT QUITE DIRECTLY OVERHEAD...HOWEVER MODELS PERFORMING POORLY AS OF LATE DOES NOT BODE WELL FOR CONFIDENCE. WILL OPT TO RAISE POPS TO 10- 12 PERCENT WITH HIGHEST POPS NOTED ACROSS THE NWRN ZONES THIS AFTN...AND KEEPING POPS AROUND 12 PERCENT ACROSS THE NWRN ZONES ONCE AGAIN FOR TONIGHT. WILL LET LATER SHIFTS SEE HOW RADAR TRENDS ARE SHAPING UP THIS AFTN AND EVENING AND WHETHER OR NOT POPS NEED TO BE RAISED TO MENTIONABLE LEVELS. IF STORMS DO INDEED DEVELOP...MUCAPE OF 2-2.5 KJ/KG MAY RAISE CONCERNS FOR THE POTENTIAL FOR STRONG STORMS...HOWEVER RATHER WEAK 0-6 KM BULK SHEAR /LESS THAN 20 KTS/ MAY KEEP STORM STRENGTH ON THE TAME SIDE. OTHERWISE...ANOTHER DAY OF SEASONAL WARMTH IS ON TAP /LOWER 90S/ FOLLOWED BY A MILD NIGHT /LOWER 60S ACROSS NW TO LOWER 70S FAR EAST/. .LONG TERM... THE UPPER RIDGE OVER THE SWRN CONUS AND ADJACENT WATERS OFF THE COAST OF SRN AND BAJA CALIF WILL EXPAND EWD THROUGH THE WEEKEND RESULTING IN NEAR NORMAL TEMPERATURES AND FAIR BUT BREEZY WEATHER THROUGH AT LEAST THE FIRST HALF OF NEXT WEEK. A WWD-MOVING INVERTED UPPER TROUGH WILL MOVE ACROSS DEEP SOUTH TEXAS THIS WEEKEND AND ONTO THE MOUNTAINS OF NRN MEXICO TOWARD THE MIDDLE OF NEXT WEEK. AS MOISTURE FROM THIS SYSTEM SPREADS NWD INTO NEW MEXICO AND AS A LOW-AMPLITUDE UPPER TROUGH DEVELOPS OVER CALIF COULD SEE SOME PRECIP RETURN TO NEW MEXICO AND POSSIBLY THE SOUTH PLAINS AND PANHANDLE. CONFIDENCE OF THIS DEVELOPMENT BY DAYS 6 AND 7 OF THE FCST TOO LOW TO INSERT PRECIP MENTION JUST YET. UNTIL THEN WARM AND DRY WITH ONLY MINOR ADJUSTMENTS TO PREVIOUS FCST. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 90 64 92 63 / 10 10 0 0 TULIA 91 66 92 65 / 10 0 0 0 PLAINVIEW 91 65 91 65 / 10 0 0 0 LEVELLAND 93 65 92 66 / 10 0 0 0 LUBBOCK 93 66 92 68 / 10 0 0 0 DENVER CITY 91 63 92 64 / 10 0 0 0 BROWNFIELD 92 65 92 66 / 10 0 0 0 CHILDRESS 94 70 95 70 / 10 0 0 0 SPUR 94 68 93 67 / 10 0 0 0 ASPERMONT 95 70 94 70 / 10 0 0 0 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 29/07
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1136 PM CDT Thu Jun 18 2015 .AVIATION... /06Z TAFS/ Little change made to the previous set of TAFs. Low level moisture is still expected to return northward, resulting in MVFR CIGs at southern locations. Thunderstorms from earlier may delay these low clouds somewhat, but should not keep them from making progress north later tonight. By mid to late morning, all sites should scatter out to VFR conditions with only scattered cumulus affecting the area tomorrow afternoon, but no SHRA or TSRA expected tomorrow. We may see a few gusts near 15 knots during the afternoon at southern sites. && .PREV DISCUSSION... /ISSUED 808 PM CDT Thu Jun 18 2015/ UPDATE... Made a quick update to the forecast to carry higher rain chances across our far southeastern counties this evening, and to include a mention of locally heavy rainfall. Scattered, slow moving showers and thunderstorms are occurring southeast of a Sonora to Brady line. Outflow boundary emanating from this convection is moving slowly to the northwest, and some new development is possible along and behind this outflow boundary. Expect this shower and thunderstorms activity to dissipate prior to 11 PM tonight. PREV DISCUSSION... /ISSUED 649 PM CDT Thu Jun 18 2015/ AVIATION... /00Z TAFS/ VFR conditions currently prevail across the area. There are a few isolated showers and thunderstorms near KSOA, KJCT, and KBBD, so will have a mention of VCTS for this activity through the evening hours. Otherwise, expect MVFR to possibly IFR conditions to develop after 06Z again tonight, mainly for the four southern terminals. Just mentioned a SCT020 group for KABI as they will probably be too far north for low clouds again. Light and variable or light southerly winds can be expected. 20 PREV DISCUSSION... /ISSUED 342 PM CDT Thu Jun 18 2015/ SHORT TERM... (Tonight and Friday) Bill remnants well to the northeast, with a weak shear axis draped from the Hill Country northeast into the center of Bill. Have continued to see scattered showers and storms across the Hill Country and these should continue. Both the HRRR and the TTU WRF to a lesser extent show a little convection developing later this afternoon across much of the remainder of the area. Will continue the mention of a few isolated showers and storms for a few hours this evening. A few storms possible again on Friday afternoon across the southeast as the shear axis slowly erodes, but rain chances at most locations will be so small that will not mention in the forecast. Otherwise, warm and humid air mass in place with surface dewpoints hanging near 70 in most locations. LONG TERM... (Friday Night through Thursday) Upper high pressure will continue to build eastward over the southwestern states this weekend as an inverted upper trough expands into south Texas from northern Mexico. There is a slight chance of showers and thunderstorms associated with the Mexican disturbance over the Interstate 10 corridor Saturday afternoon and through Saturday night. The presence of the Mexican upper low will keep a slight chance of rainfall over primarily the southern portions of the forecast area south of Interstate 20 through Monday night. As the center of the upper high pressure area moves east over the southern Plains late Monday the upper inverted trough will be deflected to our west as will any associated rainfall. The forecast will therefore remain dry Monday through Thursday. Temperatures will remain seasonal with afternoon highs in the upper 80s to the lower 90s and morning lows around 70. 15 && .PRELIMINARY POINT TEMPS/POPS... Abilene 71 91 72 91 72 / 10 10 5 5 5 San Angelo 71 90 70 89 70 / 10 10 5 5 10 Junction 70 87 71 87 71 / 40 20 10 20 20 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
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AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
904 PM EDT SAT JUN 20 2015 .SYNOPSIS... THE REMNANTS OF TROPICAL DEPRESSION BILL WILL PROGRESS EASTWARD THROUGH WEST VIRGINIA AND PENNSYLVANIA TONIGHT INTO TOMORROW. FOR NEXT WEEK...THE AREA WILL BE IN A WEATHER PATTERN THAT WILL ALLOW FOR MULTIPLE SYSTEMS TO PROGRESS SOUTHEAST INTO THE AREA FROM THE GREAT LAKES REGION...EACH ONE WITH THE POTENTIAL FOR ADDITIONAL SHOWERS AND STORMS...ESPECIALLY ACROSS WESTERN AND NORTHERN PARTS OF THE AREA. && .NEAR TERM /THROUGH SUNDAY/... AS OF 840 PM EDT SATURDAY... THE SEVERE THUNDERSTORM AND FLASH FLOOD WATCHES HAVE BEEN CANCELLED FOR THE BLACKSBURG FORECAST AREA. A SMALL AREA OF SHOWERS SHIFTING ACROSS SE WV SHOULD STAY ON THE LIGHT OR MODERATE SIDE SUCH THAT HEAVY DOWNPOURS THAT COULD LEAD TO FLASH FLOODING HAS ENDED. NO OTHER CHANGES MADE TO THE FORECAST AS OF THIS AFD. LATEST HRRR FAVORS DRYING OVERNIGHT INTO THE SW CWA WITH SHOWERS LINGERING OVER NW CWA ACROSS SE WV INTO THE HIGHLANDS...AND ADJUSTED POPS TO SHOW THIS. PREVIOUS VALID DISCUSSION... LATE TONIGHT...THE AREA WILL BE ON THE BACK SIDE OF THE SYSTEM...BUT MODERATELY STRONG 850 MB NORTHWEST WINDS WILL HELP MAINTAIN UPSLOPE CLOUD COVER AND ISOLATED TO SCATTERED SHOWERS. LOW TEMPERATURES WILL REMAIN ON THE MILD SIDE...ABOUT 10 DEGREES ABOVE NORMAL...WITH UPPER 60S ACROSS THE MOUNTAINS AND LOWER 70S ACROSS THE PIEDMONT. ON SUNDAY...DRIER AIR WILL WORK ITS WAY INTO THE REGION AND HELP TO ERODE THE EARLY MORNING CLOUD COVER BY THE LATE MORNING. HOWEVER...EXPECT A RETURN OF INCREASING CLOUD COVER AND ISOLATED TO SCATTERED SHOWERS ACROSS THE WESTERN PARTS OF THE REGION. A FRONTAL BOUNDARY WILL APPROACH FROM THE NORTHWEST A BE THE TRIGGER FOR THIS ADDITIONAL CONVECTIVE ACTIVITY. HIGH TEMPERATURES WILL BE ABOUT 10 DEGREE ABOVE NORMAL WITH MID TO UPPER 80S ACROSS THE MOUNTAINS AND LOWER 90S ACROSS THE PIEDMONT. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/... AS OF 300 PM EDT SATURDAY... SURFACE FRONT PUSHES SOUTH INTO THE OHIO VALLEY AND MID ATLANTIC REGION ON SUNDAY NIGHT...BUT MIGHT STALL BEFORE PASSING ALL THE WAY THROUGH THE FORECAST AREA. BY TUESDAY 850 TEMPERATURES PEAK AROUND +20 TO +24 ON TUESDAY...BUT THE HOT AIR MASS WILL ALSO HAVE A STRONG CAP WITH 700 MB TEMPERATURES CLOSE TO +12. WITH SURFACE DEW POINTS ABOVE 70 AND MUCAPES APPROACHING 3000 J/KG ANY STORMS THAT DO FIRE MAY BE STRONG TO SEVERE. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 300 PM EDT SATURDAY... ANOTHER FRONT APPROACHES THE AREA ON TUESDAY NIGHT AND WEDNESDAY BUT STILL WITH LIMITED PROGRESS SOUTH THROUGH THE MID ATLANTIC REGION. PATTERN EVOLVES ON THURSDAY AND FRIDAY FROM ZONAL AT 500 MB TO A MORE AMPLIFIED RIDGE OVER THE WESTERN UNITED STATES AND TROF IN THE EAST. ECMWF HAS SOME SHORT WAVES AND LIFT COMING THROUGH THE NORTHERN JET STREAM INTO THE FORECAST AREA ON THURSDAY AND FRIDAY. A DECENT COLD FRONT FRONT WILL COME THROUGH THE AREA ON THURSDAY AND FRIDAY...FOLLOWED BY A COOLER AIR MASS AND EASTERLY LOW LEVEL FLOW ON SATURDAY. && .AVIATION /01Z SUNDAY THROUGH THURSDAY/... AS OF 725 PM EDT SATURDAY... EXPECT SHRA AROUND LWB TO LYH/DAN POSSIBLE TS AT DAN TIL 01Z. OTHERWISE VFR RIGHT THRU THE EVENING TO BECOME MVFR AT LEAST TOWARD THE BLF/LWB/BCB AREA WITH WNW FLOW AND UPSLOPE SHOWERS INVOF OF THOSE TERMINALS. MAY ALSO HAVE FOG FORMATION...BUT GIVEN CLOUD COVER...THE CONFIDENCE OF FOG BELOW IFR IS LOW. WINDS WILL BE GUSTY AT TIMES THIS EVENING...THEN DIMINISH OVERNIGHT...WITH SOME BRIEF GUSTINESS SUNDAY MORNING.. LOWER CIGS WILL SCATTER OUT TO SKC/SCT VFR BY LATE MORNING. NOT SEEING MUCH OF A THREAT OF PRECIP SO LEFT OUT OF TAFS FOR SUNDAY AFTERNOON...THOUGH A FEW SHRA/TSRA MAY HEAD CLOSER TO LWB/BLF AFTER 21Z SUNDAY. AVIATION EXTENDED DISCUSSION... A COLD FRONT WILL APPROACH AND ENTER THE REGION SUNDAY NIGHT. ANTICIPATE A RETURN OF SCATTERED SHOWERS AND STORMS TO MAINLY WESTERN PARTS OF THE REGION...ALONG WITH POCKETS OF BRIEF MVFR CONDITIONS. THE REGION WILL REMAIN IN AN UNSETTLED WEATHER PATTERN THROUGH THURSDAY. ADDITIONAL SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED...AGAIN PRIMARILY IN THE WEST...THANKS TO ADDITIONAL NORTHWEST FLOW DISTURBANCES...OR ADDITIONAL FRONTAL BOUNDARIES THAT APPROACH OR MOVE INTO THE AREA. && .EQUIPMENT... HINTON NOAA WEATHER RADIO TRANSMITTER BROADCASTING ON A FREQUENCY OF 162.425 MHZ HAS BEEN OFF THE AIR SINCE EARLY THIS AFTERNOON. THIS IS DUE TO TELEPHONE OUTAGE...THAT THE LOCAL TELEPHONE COMPANY IS WORKING ON. THERE IS NO ESTIMATED TIME FOR THIS REPAIR TO BE FIXED. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...DS NEAR TERM...DS/WP SHORT TERM...AMS LONG TERM...AMS AVIATION...DS/WP EQUIPMENT...WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
844 PM EDT SAT JUN 20 2015 .SYNOPSIS... THE REMNANTS OF TROPICAL DEPRESSION BILL WILL PROGRESS EASTWARD THROUGH WEST VIRGINIA AND PENNSYLVANIA TONIGHT INTO TOMORROW. FOR NEXT WEEK...THE AREA WILL BE IN A WEATHER PATTERN THAT WILL ALLOW FOR MULTIPLE SYSTEMS TO PROGRESS SOUTHEAST INTO THE AREA FROM THE GREAT LAKES REGION...EACH ONE WITH THE POTENTIAL FOR ADDITIONAL SHOWERS AND STORMS...ESPECIALLY ACROSS WESTERN AND NORTHERN PARTS OF THE AREA. && .NEAR TERM /THROUGH SUNDAY/... AS OF 840 PM EDT SATURDAY... THE SEVERE THUNDERSTORM AND FLASH FLOOD WATCHES HAVE BEEN CANCELLED FOR THE BLACKSBURG FORECAST AREA. A SMALL AREA OF SHOWERS SHIFTING ACROSS SE WV SHOULD STAY ON THE LIGHT OR MODERATE SIDE SUCH THAT HEAVY DOWNPOURS THAT COULD LEAD TO FLASH FLOODING HAS ENDED. NO OTHER CHANGES MADE TO THE FORECAST AS OF THIS AFD. LATEST HRRR FAVORS DRYING OVERNIGHT INTO THE SW CWA WITH SHOWERS LINGERING OVER NW CWA ACROSS SE WV INTO THE HIGHLANDS...AND ADJUSTED POPS TO SHOW THIS. PREVIOUS VALID DISCUSSION... LATE TONIGHT...THE AREA WILL BE ON THE BACK SIDE OF THE SYSTEM...BUT MODERATELY STRONG 850 MB NORTHWEST WINDS WILL HELP MAINTAIN UPSLOPE CLOUD COVER AND ISOLATED TO SCATTERED SHOWERS. LOW TEMPERATURES WILL REMAIN ON THE MILD SIDE...ABOUT 10 DEGREES ABOVE NORMAL...WITH UPPER 60S ACROSS THE MOUNTAINS AND LOWER 70S ACROSS THE PIEDMONT. ON SUNDAY...DRIER AIR WILL WORK ITS WAY INTO THE REGION AND HELP TO ERODE THE EARLY MORNING CLOUD COVER BY THE LATE MORNING. HOWEVER...EXPECT A RETURN OF INCREASING CLOUD COVER AND ISOLATED TO SCATTERED SHOWERS ACROSS THE WESTERN PARTS OF THE REGION. A FRONTAL BOUNDARY WILL APPROACH FROM THE NORTHWEST A BE THE TRIGGER FOR THIS ADDITIONAL CONVECTIVE ACTIVITY. HIGH TEMPERATURES WILL BE ABOUT 10 DEGREE ABOVE NORMAL WITH MID TO UPPER 80S ACROSS THE MOUNTAINS AND LOWER 90S ACROSS THE PIEDMONT. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/... AS OF 300 PM EDT SATURDAY... SURFACE FRONT PUSHES SOUTH INTO THE OHIO VALLEY AND MID ATLANTIC REGION ON SUNDAY NIGHT...BUT MIGHT STALL BEFORE PASSING ALL THE WAY THROUGH THE FORECAST AREA. BY TUESDAY 850 TEMPERATURES PEAK AROUND +20 TO +24 ON TUESDAY...BUT THE HOT AIR MASS WILL ALSO HAVE A STRONG CAP WITH 700 MB TEMPERATURES CLOSE TO +12. WITH SURFACE DEW POINTS ABOVE 70 AND MUCAPES APPROACHING 3000 J/KG ANY STORMS THAT DO FIRE MAY BE STRONG TO SEVERE. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 300 PM EDT SATURDAY... ANOTHER FRONT APPROACHES THE AREA ON TUESDAY NIGHT AND WEDNESDAY BUT STILL WITH LIMITED PROGRESS SOUTH THROUGH THE MID ATLANTIC REGION. PATTERN EVOLVES ON THURSDAY AND FRIDAY FROM ZONAL AT 500 MB TO A MORE AMPLIFIED RIDGE OVER THE WESTERN UNITED STATES AND TROF IN THE EAST. ECMWF HAS SOME SHORT WAVES AND LIFT COMING THROUGH THE NORTHERN JET STREAM INTO THE FORECAST AREA ON THURSDAY AND FRIDAY. A DECENT COLD FRONT FRONT WILL COME THROUGH THE AREA ON THURSDAY AND FRIDAY...FOLLOWED BY A COOLER AIR MASS AND EASTERLY LOW LEVEL FLOW ON SATURDAY. && .AVIATION /01Z SUNDAY THROUGH THURSDAY/... AS OF 725 PM EDT SATURDAY... EXPECT SHRA AROUND LWB TO LYH/DAN POSSIBLE TS AT DAN TIL 01Z. OTHERWISE VFR RIGHT THRU THE EVENING TO BECOME MVFR AT LEAST TOWARD THE BLF/LWB/BCB AREA WITH WNW FLOW AND UPSLOPE SHOWERS INVOF OF THOSE TERMINALS. MAY ALSO HAVE FOG FORMATION...BUT GIVEN CLOUD COVER...THE CONFIDENCE OF FOG BELOW IFR IS LOW. WINDS WILL BE GUSTY AT TIMES THIS EVENING...THEN DIMINISH OVERNIGHT...WITH SOME BRIEF GUSTINESS SUNDAY MORNING.. LOWER CIGS WILL SCATTER OUT TO SKC/SCT VFR BY LATE MORNING. NOT SEEING MUCH OF A THREAT OF PRECIP SO LEFT OUT OF TAFS FOR SUNDAY AFTERNOON...THOUGH A FEW SHRA/TSRA MAY HEAD CLOSER TO LWB/BLF AFTER 21Z SUNDAY. AVIATION EXTENDED DISCUSSION... A COLD FRONT WILL APPROACH AND ENTER THE REGION SUNDAY NIGHT. ANTICIPATE A RETURN OF SCATTERED SHOWERS AND STORMS TO MAINLY WESTERN PARTS OF THE REGION...ALONG WITH POCKETS OF BRIEF MVFR CONDITIONS. THE REGION WILL REMAIN IN AN UNSETTLED WEATHER PATTERN THROUGH THURSDAY. ADDITIONAL SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED...AGAIN PRIMARILY IN THE WEST...THANKS TO ADDITIONAL NORTHWEST FLOW DISTURBANCES...OR ADDITIONAL FRONTAL BOUNDARIES THAT APPROACH OR MOVE INTO THE AREA. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...DS NEAR TERM...DS/WP SHORT TERM...AMS LONG TERM...AMS AVIATION...DS/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
736 PM EDT SAT JUN 20 2015 .SYNOPSIS... THE REMNANTS OF TROPICAL DEPRESSION BILL WILL PROGRESS EASTWARD THROUGH WEST VIRGINIA AND PENNSYLVANIA TONIGHT INTO TOMORROW. THIS SYSTEM WILL CONTINUE TO BRING ISOLATED TO SCATTERED SHOWERS AND STORMS TO THE AREA THIS EVENING AND OVERNIGHT. FOR NEXT WEEK...THE AREA WILL BE IN A WEATHER PATTERN THAT WILL ALLOW FOR MULTIPLE SYSTEMS TO PROGRESS SOUTHEAST INTO THE AREA FROM THE GREAT LAKES REGION...EACH ONE WITH THE POTENTIAL FOR ADDITIONAL SHOWERS AND STORMS...ESPECIALLY ACROSS WESTERN AND NORTHERN PARTS OF THE AREA. && .NEAR TERM /THROUGH SUNDAY/... AS OF 720 PM EDT SATURDAY... STRONG/SEVERE THUNDERSTORMS RIGHT ON THE ERN FRINGE OF OUR CWA...AND WILL BE CANCELLING A GOOD CHUNK OF SVR WATCH 381 SOON...LEAVING IT UP FOR OUR FAR ERN COUNTIES TIL STORMS CLEAR. PER COLLABORATION WITH WFO CHARLESTON WV...AM LEANING TOWARD DROPPING THE FLASH FLOOD WATCH LATER THIS EVENING AS DEEP CONVECTION SEEMS TO BE LACKING OVER THE WV MTNS. THINK RAINFALL RATES WILL BE LOWER THEREFORE LOWERING ANY FLASH FLOOD THREAT. LATEST HRRR FAVORS DRYING OVERNIGHT INTO THE SW CWA WITH SHOWERS LINGERING OVER NW CWA ACROSS SE WV INTO THE HIGHLANDS...AND ADJUSTED POPS TO SHOW THIS. NO OTHER MAJOR CHANGES TO THE FORECAST BEYOND THE SVR WATCH AND POPS/WX. PREVIOUS VALID DISCUSSION... LATE TONIGHT...THE AREA WILL BE ON THE BACK SIDE OF THE SYSTEM...BUT MODERATELY STRONG 850 MB NORTHWEST WINDS WILL HELP MAINTAIN UPSLOPE CLOUD COVER AND ISOLATED TO SCATTERED SHOWERS. LOW TEMPERATURES WILL REMAIN ON THE MILD SIDE...ABOUT 10 DEGREES ABOVE NORMAL...WITH UPPER 60S ACROSS THE MOUNTAINS AND LOWER 70S ACROSS THE PIEDMONT. ON SUNDAY...DRIER AIR WILL WORK ITS WAY INTO THE REGION AND HELP TO ERODE THE EARLY MORNING CLOUD COVER BY THE LATE MORNING. HOWEVER...EXPECT A RETURN OF INCREASING CLOUD COVER AND ISOLATED TO SCATTERED SHOWERS ACROSS THE WESTERN PARTS OF THE REGION. A FRONTAL BOUNDARY WILL APPROACH FROM THE NORTHWEST A BE THE TRIGGER FOR THIS ADDITIONAL CONVECTIVE ACTIVITY. HIGH TEMPERATURES WILL BE ABOUT 10 DEGREE ABOVE NORMAL WITH MID TO UPPER 80S ACROSS THE MOUNTAINS AND LOWER 90S ACROSS THE PIEDMONT. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/... AS OF 300 PM EDT SATURDAY... SURFACE FRONT PUSHES SOUTH INTO THE OHIO VALLEY AND MID ATLANTIC REGION ON SUNDAY NIGHT...BUT MIGHT STALL BEFORE PASSING ALL THE WAY THROUGH THE FORECAST AREA. BY TUESDAY 850 TEMPERATURES PEAK AROUND +20 TO +24 ON TUESDAY...BUT THE HOT AIR MASS WILL ALSO HAVE A STRONG CAP WITH 700 MB TEMPERATURES CLOSE TO +12. WITH SURFACE DEW POINTS ABOVE 70 AND MUCAPES APPROACHING 3000 J/KG ANY STORMS THAT DO FIRE MAY BE STRONG TO SEVERE. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 300 PM EDT SATURDAY... ANOTHER FRONT APPROACHES THE AREA ON TUESDAY NIGHT AND WEDNESDAY BUT STILL WITH LIMITED PROGRESS SOUTH THROUGH THE MID ATLANTIC REGION. PATTERN EVOLVES ON THURSDAY AND FRIDAY FROM ZONAL AT 500 MB TO A MORE AMPLIFIED RIDGE OVER THE WESTERN UNITED STATES AND TROF IN THE EAST. ECMWF HAS SOME SHORT WAVES AND LIFT COMING THROUGH THE NORTHERN JET STREAM INTO THE FORECAST AREA ON THURSDAY AND FRIDAY. A DECENT COLD FRONT FRONT WILL COME THROUGH THE AREA ON THURSDAY AND FRIDAY...FOLLOWED BY A COOLER AIR MASS AND EASTERLY LOW LEVEL FLOW ON SATURDAY. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... AS OF 725 PM EDT SATURDAY... EXPECT SHRA AROUND LWB TO LYH/DAN POSSIBLE TS AT DAN TIL 01Z. OTHERWISE VFR RIGHT THRU THE EVENING TO BECOME MVFR AT LEAST TOWARD THE BLF/LWB/BCB AREA WITH WNW FLOW AND UPSLOPE SHOWERS INVOF OF THOSE TERMINALS. MAY ALSO HAVE FOG FORMATION...BUT GIVEN CLOUD COVER...THE CONFIDENCE OF FOG BELOW IFR IS LOW. WINDS WILL BE GUSTY AT TIMES THIS EVENING...THEN DIMINISH OVERNIGHT...WITH SOME BRIEF GUSTINESS SUNDAY MORNING.. LOWER CIGS WILL SCATTER OUT TO SKC/SCT VFR BY LATE MORNING. NOT SEEING MUCH OF A THREAT OF PRECIP SO LEFT OUT OF TAFS FOR SUNDAY AFTERNOON...THOUGH A FEW SHRA/TSRA MAY HEAD CLOSER TO LWB/BLF AFTER 21Z SUNDAY. AVIATION EXTENDED DISCUSSION... A COLD FRONT WILL APPROACH AND ENTER THE REGION SUNDAY NIGHT. ANTICIPATE A RETURN OF SCATTERED SHOWERS AND STORMS TO MAINLY WESTERN PARTS OF THE REGION...ALONG WITH POCKETS OF BRIEF MVFR CONDITIONS. THE REGION WILL REMAIN IN AN UNSETTLED WEATHER PATTERN THROUGH THURSDAY. ADDITIONAL SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED...AGAIN PRIMARILY IN THE WEST...THANKS TO ADDITIONAL NORTHWEST FLOW DISTURBANCES...OR ADDITIONAL FRONTAL BOUNDARIES THAT APPROACH OR MOVE INTO THE AREA. && .HYDROLOGY... AS OF 730 PM EDT SATURDAY... RADAR SHOWING WEAKENING BAND OF SHOWERS ACROSS WV...AND WILL NOT ANY DEEP CONVECTION OVERNIGHT. RAINFALL FROM STORMS EARLIER DUMPED ABOUT 1/2 TO 1 INCH IN A FEW SPOTS...BUT DUE TO FAST MOVEMENT FLOODING WAS NOT A THREAT. SINCE THE HEAVY RAIN THREAT IS LESSENING MAY DROP THE FLASH FLOOD WATCH LATER THIS EVENING. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...FLASH FLOOD WATCH THROUGH SUNDAY MORNING FOR VAZ007-009>014- 018>020-022>024. NC...NONE. WV...FLASH FLOOD WATCH THROUGH SUNDAY MORNING FOR WVZ042>044-507- 508. && $$ SYNOPSIS...DS NEAR TERM...DS/WP SHORT TERM...AMS LONG TERM...AMS AVIATION...DS/WP HYDROLOGY...WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
202 PM EDT SAT JUN 20 2015 .SYNOPSIS... SHOWER AND THUNDERSTORM ACTIVITY WILL INCREASE THIS MORNING AND AFTERNOON AS TROPICAL DEPRESSION BILL APPROACHES FROM THE WEST... WITH HEAVY RAIN EXPECTED FOR THIS EVENING INTO TONIGHT. WITH THE SYSTEMS DEPARTURE BY DAWN SUNDAY...ATTENTION TURNS TO UPPER LEVEL RIDGING ACROSS THE PLAINS...WHICH WILL BRING NORTHWESTERLY WINDFLOW ALOFT TO THE MID ATLANTIC. DISTURBANCES EMBEDDED WITHIN THE NORTHWESTERLY FLOW WILL BRING ROUNDS OF THUNDERSTORM ACTIVITY THROUGH THE MIDDLE OF NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1245 PM EDT SATURDAY... THERE WILL BE NO MAJOR CHANGES TO THE FORECAST FOR THE REMAINDER OF THE AFTERNOON. HOWEVER...SOME MINOR ADJUSTMENTS HAVE BEEN MADE. A FEW AREAS ACROSS THE REGION HAVE REACHED TEMPERATURES THAT ARE AT OR A COUPLE OF DEGREES ABOVE THE FORECAST HIGH TEMPERATURE. HOWEVER...THESE SAME LOCATIONS...MAINLY IN THE WEST...ARE IN STORE FOR PLENTY OF CLOUD COVER AND INCREASING CHANCES OF PRECIPITATION THIS AFTERNOON. HAVE RAISED THE EXPECTED HIGHS...BUT BY NOT MUCH ABOVE THE CURRENT READINGS. SHOWERS HAVE STARTED ARRIVING IN THE WEST...FROM THE WEST...AND SOME HAVE ALSO STARTED TO DEVELOP...ALSO IN WESTERN PARTS OF THE REGION. HAVE MADE MINOR ADJUSTMENTS TO THE PRECIPITATION CHANCES IN THIS REGION BASED UPON THE LATEST COVERAGE AND EXPECTED TRENDS THE NEXT COUPLE OF HOURS. AS OF 950 AM EDT SATURDAY... THE OVERALL FORECAST FOR TODAY STILL LOOKS ON TRACK. WE WILL BE MAKING SOME ADJUSTMENTS IN THE NEAR TERM...AND ALSO THE QUANTITY OF PRECIPITATION EXPECTED THROUGH TONIGHT. THE FIRST ADJUSTMENT IS THE TIMING OF THE ARRIVAL OF PRECIPITATION...ESPECIALLY ACROSS THE FAR WESTERN PARTS OF THE REGION. NO PRECIPITATION IS CURRENTLY BEING DETECTED ON RADAR IN THE FORECAST AREA. THIS IS EXPECTED TO CHANGE. LOOKING TO OUR WEST...REGIONAL RADARS ARE DETECTING THE FIRST BAND OF SHOWERS THAT WILL ARRIVE IN THE WEST...AND AS DAYTIME HEATING INCREASES...THESE SHOWERS WILL HAVE A GREATER CHANCE OF HAVING SOME THUNDER AROUND THE TIME THEY ARRIVE. CURRENTLY...THAT TIME LOOKS BETWEEN 1100 AM AND NOON. ADDITIONAL ISOLATED CONVECTION IS ALSO EXPECTED THROUGH THE END OF THE MORNING HOURS JUST IN ADVANCE OF THIS FIRST BAND. THE AFTERNOON FORECAST STILL LOOK ON TRACK WITH THE BULK OF THE PRECIPITATION ARRIVING DURING THE MID TO LATE AFTERNOON...WITH THE GREATEST FOCUS ACROSS THE NORTHWEST PARTS OF THE AREA. REGARDING PRECIPITATION TOTALS....THE LATEST SOLUTION FROM WPC DEPICTS ON AVERAGE ABOUT ANOTHER QUARTER OF A INCH ACROSS MOST OF THE AREA THAT IS CURRENTLY HIGHLIGHTED BY THE FLASH FLOOD WATCH...THUS ADDING GREATER CREDENCE TO THE CONTINUATION OF THE WATCH. NO OTHER SIGNIFICANT CHANGES PLANNED AT THIS TIME. FOR PROVISION OF ADDITIONAL UPPER AIR DATA...THERE WILL BE A SPECIAL 18Z/2PM UPPER AIR WEATHER BALLOON LAUNCH BY THIS OFFICE...WEATHER PERMITTING. AS OF 400 AM EDT SATURDAY... RADAR INDICATING BANDS OF SHOWER ACTIVITY ACROSS KENTUCKY THIS MORNING AS TD BILL MAKES ITS APPROACH UP THE OHIO RIVER VALLEY. RAPID UPDATE WEATHER MODELS SUCH AS THE HRRR AND THE RAP ARE IN GOOD AGREEMENT THAT THE LEADING BANDS WILL ENTER OUR MOUNTAIN EMPIRE/ SOUTHEAST WEST VIRGINIA COUNTIES AROUND SUNRISE...BRINGING SPOTTY SHOWER ACTIVITY. STILL...DEEPER MOISTURE AND INCREASED CLOUD COVER WILL NOT ARRIVE UNTIL AFTERNOON...AND BELIEVE WE WILL STILL HAVE ENOUGH SUNSHINE TO ALLOW FOR SIGNIFICANT HEATING DURING THE MORNING...ESPECIALLY EAST OF THE BLUE RIDGE. AS SUCH...STILL EXPECT SOME SHOWERS TO INTENSIFY INTO THUNDERSTORMS DURING LATE MORNING AND EARLY AFTERNOON...A FEW OF WHICH WILL BECOME STRONG TO SEVERE GIVEN CAPE EXCEEDING 1000 J/KG FOR MUCH OF THE AREA DURING EARLY AFTERNOON...AS WELL AS INCREASING LOW LEVEL WIND SHEAR TOWARD EVENING AS THE CENTER OF BILL PASSES ACROSS SOUTHERN OHIO. OUTSIDE OF SEVERE POTENTIAL...BILL WILL ALSO BRING DEEP TROPICAL MOISTURE...WITH PRECIPITABLE WATER VALUES REACHING 2+ INCHES DURING THE EVENING FOR MUCH OF THE AREA. FACTORING IN OROGRAPHIC LIFT... BELIEVE WE WILL SEE RAINFALL AMOUNTS ON AVERAGE RANGE FROM 1 TO 1.5 INCHES FOR THE BLUE RIDGE WESTWARD...WITH 2 TO 3 INCHES IN A FEW SPOTS...ESPECIALLY WESTERN GREENBRIER COUNTY. FURTHER EAST... RAINFALL AMOUNTS WILL TAPER DOWN TO AROUND A HALF INCH THE PIEDMONT OF NORTH CAROLINA. BUT GIVEN THE DEEP MOISTURE AND INSTABILITY OF THE SYSTEM...COMBINED WITH THE POTENTIAL FOR TRAINING OF CELLS OVER THE SAME LOCATIONS...WILL CONTINUE WITH THE FLASH FLOOD WATCH CURRENTLY IN EFFECT. BILL IS A FAST MOVING SYSTEM...AND AS QUICKLY AS IT ARRIVES...WE WILL SEE RAINFALL BEGIN TO DIMINISH QUICKLY AFTER 2 AM SUNDAY AS THE MAIN ENERGY OF THE SYSTEM EXITS TO THE EAST. BY SUNRISE SUNDAY... SHOULD ONLY SEE SPOTTY UPSLOPE SHOWER ACTIVITY ACROSS THE WESTERN RIDGES...AND PERHAPS A FEW SHOWERS ACROSS THE PIEDMONT. && .SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/... AS OF 415 AM EDT SATURDAY... CONSIDERABLY QUIET WEATHER EXPECTED AT THE BEGINNING OF THIS PERIOD AS THE REMNANTS OF T.S. BILL ARE LOCATED IN THE DCA/BWI AREA AT THE 12Z SUN...RAPIDLY ACCELERATING OFF THE NJ/NY COAST BY SUNDAY EVENING. NO ADDITIONAL CONCERNS FROM BILL THIS PERIOD. HOWEVER...THE PERIOD WILL BE QUITE UNSETTLED WITH DAILY ROUNDS OF CONVECTION LIKELY AND INCREASING POTENTIAL FOR NORTHWEST FLOW MCS DURING THIS TIME FRAME. AS A RESULT...THERE WILL BE MULTIPLE CHANCES FOR STRONG TO SEVERE THUNDERSTORMS THIS TIME FRAME...WITH AN EVEN GREATER CHANCE FOR SUCH DURING THE LONG TERM PERIOD. ONCE BILL DEPARTS THE AREA EARLY SUNDAY...THE MEAN JET WILL BE LOCATED ACROSS THE NORTHERN STATES ON THE NORTH SIDE OF A BROAD SUBTROPICAL UPPER RIDGE CENTERED IN THE DESERT SOUTHWEST...BUT ACTUALLY EXTENDING EASTWARD AND WESTWARD FROM THIS LOCATION ACROSS ALL SOUTHERN STATES. AS THE WEEK PROGRESSES...THE UPPER RIDGE WILL AMPLIFY ACROSS THE WESTERN STATES...RESULTING IN DECREASING HEIGHTS ACROSS THE EASTERN U.S. AS TROUGHING DEVELOPS VICINITY OF THE GREAT LAKES. THIS WILL LEAVE OUR REGION AMIDST AN INCREASINGLY ACTIVE AND UNSTABLE NORTHWEST FLOW ALOFT. FOR SUN/SUN EVENING...A SHORT WAVE WILL BE TRACKING ON THE HEELS EASTWARD ACROSS THE OH VALLEY ON THE HEELS OF THE REMNANTS OF T.S. BILL. A VERY UNSTABLE AIR MASS WILL RESIDE ACROSS THE OH VALLEY AS THIS DISTURBANCE TRACKS THROUGH. SPC HAS ALREADY OUTLOOKED A WEST-EAST ORIENTED SLIGHT RISK AREA ACROSS THE OH VALLEY INTO PA...WITH A MARGINAL RISK SURROUNDING THIS TO THE SOUTH. IF AN MCS WERE ABLE TO GET GOING AS APPEARS POSSIBLE SUN AFTERNOON...THE TRAJECTORY WOULD CARRY THE REMNANTS OF THIS SOUTHEAST INTO OUR REGION BY EVENING BEFORE IT DISSIPATES AS IT MOVES TOWARD THE UPPER RIDGE TO THE SOUTH. MAIN THREAT WOULD BE DAMAGING WINDS AS IS COMMON WITH THIS TYPE OF SYSTEM. MON APPEARS TO BE THE QUIETEST DAY OF THE SHORT TERM AS THE AFOREMENTIONED SHORT WAVE TRACKS EAST AND THE UPPER RIDGE ACROSS THE CENTRAL U.S. EXTENDS BRIEFLY EASTWARD TUE-WED. HOWEVER...A WEAK REMNANT BAROCLINIC ZONE WILL LINGER ACROSS THE SW/SC/SE PART OF THE CWA AND COULD WELL BE THE FOCUS FOR SCATTERED AFTERNOON/EVENING THUNDERSTORMS...THUS HAVE INDICATED CHANCE POPS IN THIS AREA AS A RESULT...WITH LOWER POPS TO THE NORTH. TUE PROMISES TO BE MORE ACTIVE AS YET ANOTHER SHORT WAVE TRACKS ACROSS THE GREAT LAKES INTO THE NE STATES AS UPPER HEIGHTS LOWER IN RESPONSE TO THE AMPLIFICATION OF THE RIDGE IN THE WESTERN U.S. AGAIN...ANY THUNDERSTORMS THAT DEVELOP ACROSS THE OH VALLEY WILL HAVE THE CHANCE TO TRACK SOUTHEAST TOWARD OUR REGION DURING THE AFTERNOON/EVENING...AND AN EVEN BETTER CHANCE OF DOING SO TUE THAN ON SUN. THERE WILL ALSO BE A CONCERN FOR HEAT DURING THIS TIME FRAME. WITH WESTERLY SFC FLOW AND THE UPPER RIDGE JUST TO OUR SOUTH...POCKETS OF +20 TO +22C CREEP INTO MUCH OF THE CWA SUN-TUE...BUT ON TUE...EVEN POCKETS OF +25C CREEP INTO THE PIEDMONT PER GFS...ONLY +23 ON THE ECMWF/CANADIAN. THIS WILL CERTAINLY SUPPORT TEMPERATURES WELL INTO THE 90S...UPPER 90S PIEDMONT. AS OF NOW...HEIGHT INDICES REMAIN BELOW 100...BUT LATER RUNS OF THE MODELS MAY DICTATE THE NEED TO CONSIDER HEAT ADVISORIES ACROSS THE PIEDMONT...ESPECIALLY TUE. AT ANY RATE...IT WILL BE HOT AND HUMID THROUGHOUT THE PERIOD. ANY SIGNIFICANT COOLING WILL HAVE TO WAIT UNTIL THE UPPER TROUGH DEEPENS ACROSS THE EASTERN U.S...WHICH IS NOT PROGGED TO TAKE PLACE UNTIL THE END OF THE WEEK INTO NEXT WEEKEND. FOR NOW...HAVE GONE WITH A MIDDLE OF THE ROAD APPROACH ON MAX TEMPS...OPTING NOT TO ADVERTISE THE UPPER 90 TO LOW 100 READINGS INDICATED BY THE GFS ACROSS THE PIEDMONT. && .LONG TERM /WEDNESDAY THROUGH FRIDAY/... AS OF 430 AM EDT SATURDAY... UNSTABLE PATTERN AND POTENTIAL FOR MCS THUNDERSTORM SYSTEMS INCREASES THROUGH THE PERIOD AS NORTHWEST FLOW ALOFT STRENGTHS ACROSS THE REGION IN RESPONSE TO AMPLIFICATION OF THE UPPER FLOW WITH A HIGH AMPLITUDE UPPER RIDGE EXPECTED TO DEVELOP ACROSS THE WESTERN U.S. BY NEXT WEEKEND AND AN EQUALLY DEEP UPPER TROUGH EXPECTED TO EVOLVE ACROSS THE GREAT LAKES AND EASTERN U.S...WELL INTO THE SOUTHEAST STATES IN FACT. THIS COULD EVENTUALLY SERVE TO PUSH THE GREATEST THUNDERSTORM THREAT FURTHER SOUTH INTO AL/GA/SC/FL WITH TIME...BUT FOR THIS TIME FRAME...WE WILL BE PRETTY MUCH CENTERED RIGHT IN THE MIDDLE OF A VERY ACTIVE BAROCLINIC ZONE. ALL MODELS BROAD BRUSH HIGH POPS/QPF ACROSS THE REGION WITH DAILY THUNDERSTORMS THROUGH THIS ENTIRE PERIOD...WITH THE GREATEST COVERAGE ACROSS THE WEST. REALLY CANT ARGUE WITH THIS GIVEN THE PATTERN. THUS...HAVE ADVERTISED CHANCE TO HIGH CHANCE POPS AND IN A FEW CASES 60 PERCENT POPS EACH DAY THROUGH THE PERIOD...WITH A DEFINITE DIURNAL SWING TO THE POPS...HIGHEST IN THE AFTERNOON/EVENINGS DURING PEAK HEATING. WITH RESPECT TO TEMPERATURES...WE SHOULD SEE A VERY SLOW COOLING TREND AS UPPER HEIGHTS LOWER DURING THE LATER HALF OF THE WEEK IN RESPONSE TO THE DEEPENING EASTERN U.S. TROUGH AS WELL AS INCREASING CLOUDS/PRECIPITATION. 850MB TEMPS SHOULD FINALLY DROP BELOW +20C BY THE END OF THE WEEK AS THE POCKET OF +20C AND GREATER 850MB TEMPS SINKS SOUTHWARD INTO THE SOUTHEAST STATE. IT WILL REMAIN VERY HUMID...HOWEVER...WITH DEWPOINTS HOVERING NEAR 70 THROUGHOUT THE PERIOD UNTIL THE WEEKEND...WHEN THEY SHOULD DROP BACK A FEW DEGREES INTO THE 60S. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... AS OF 145 PM EDT SATURDAY... THIS AFTERNOON THROUGH TONIGHT THE REMNANTS OF TD BILL WILL PROGRESS EASTWARD THROUGH THE OHIO VALLEY. SCATTERED SHOWERS AND STORMS ARE EXPECTED TO SPREAD ACROSS THE AREA THIS AFTERNOON AND EVENING IN ASSOCIATION WITH THIS SYSTEM. MOST OF THE ACTIVITY WILL BE CONFINED TO BANDS OF ACTIVITY...ALTHOUGH ISOLATED DEVELOPMENT OUTSIDE OF THESE BANDS IS ALSO EXPECTED. OUTSIDE OF THE CONVECTION...VFR CONDITIONS ARE EXPECTED. WITHIN THE CONVECTION...BRIEF MVFR/IFR CIGS/VSBYS ARE ANTICIPATED. WIND SPEEDS WILL CONTINUE TO INCREASE ACROSS THE AREA AND SLOWLY VEER SW WITH SURFACE GUSTS OF 20-25 KTS EXPECTED. OVERNIGHT...THE AXIS OF THE TD BILL REMNANTS WILL SHIFT EAST OF THE REGION. THIS WILL CONTINUE THE VEER OF THE LOW LEVEL WINDS TO W-NW BUT CONTINUING TO BE GUSTY. A WINTER-LIKE PATTERN WILL DEVELOP WITH LOW LEVEL MOISTURE WITHIN AN UPSLOPE PATTERN YIELDING PLENTY OF MVFR CLOUD COVER ACROSS THE MOUNTAINS WITH POCKETS OF IFR ALSO EXPECTED. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL ALSO CONTINUE TO BE POSSIBLE IN THE PREFERRED UPSLOPE AREAS OF SOUTHEAST WEST VIRGINIA...SOUTH INTO THE NORTHERN MOUNTAINS OF NORTH CAROLINA. DRIER AIR WILL WORK ITS WAY INTO THE REGION LATE TONIGHT INTO THE DAY SUNDAY...FROM THE MID LEVELS AND DOWN. LOW CLOUDS WILL ERODE AROUND 15Z/11AM SUNDAY AND WINDS WILL CONTINUE TO BE GUSTY...BUT NOT QUITE AS STRONG AS THIS AFTERNOON AND OVERNIGHT. AVIATION EXTENDED DISCUSSION... A COLD FRONT WILL APPROACH AND ENTER THE REGION LATE SUNDAY AFTERNOON INTO SUNDAY NIGHT. ANTICIPATE A RETURN OF SCATTERED SHOWERS AND STORMS TO MAINLY WESTERN PARTS OF THE REGION...ALONGWITH POCKETS OF BRIEF MVFR CONDITIONS. THE REGION WILL REMAIN IN AN UNSETTLED WEATHER PATTERN THROUGH THURSDAY. ADDITIONAL SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED...AGAIN PRIMARILY IN THE WEST...THANKS TO ADDITION NORTHWEST FLOW DISTURBANCES...OR ADDITIONAL FRONTAL BOUNDARIES THAT APPROACH OR MOVE INTO THE AREA. && .HYDROLOGY... THE REMNANT LOW OF ONCE TROPICAL STORM BILL WILL PASS JUST NORTH OF THE AREA SATURDAY NIGHT. DEEP TROPICAL MOISTURE ASSOCIATED WITH THIS SYSTEM WILL COMBINE WITH A RESIDUAL FRONT ACROSS THE AREA TO POSSIBLY PRODUCE MORE WIDESPREAD SHOWERS AND STORMS TODAY...AND MORE IN THE WAY OF STEADIER HEAVIER RAINFALL SATURDAY NIGHT OVER THE MOUNTAINS. A GENERAL 1 TO 3 INCHES OF RAIN IS EXPECTED WITH LOCALLY HIGHER TOTALS WHERE HEAVIER RATES WITH EMBEDDED CONVECTION OCCURS. THIS LOOKS MOST LIKELY TO OCCUR OVER PARTS OF SOUTHEAST WEST VIRGINIA AS WELL AS THE VIRGINIA HIGHLANDS AT THIS POINT. ALTHOUGH RAINFALL HAS BEEN RATHER SPOTTY IN THE LAST FEW DAYS...SOME LOCATIONS HAVE RECEIVED AS MUCH AS 3 INCHES MAKING THOSE AREAS MORE PRONE TO FLOODING. THUS GIVEN THE FORECAST RAINFALL AND POTENTIAL FOR MUCH MORE WIDESPREAD MODERATE TO HEAVY RAIN THAN SEEN OF LATE...A FLASH FLOOD WATCH HAS BEEN ISSUED FOR MANY OF THE MOUNTAIN COUNTIES IN VIRGINIA...AND WEST VIRGINIA FOR SATURDAY AFTERNOON INTO THE EARLY MORNING HOURS OF SUNDAY FOR AT LEAST LOCALIZED FLOODING. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...FLASH FLOOD WATCH THROUGH SUNDAY MORNING FOR VAZ007-009>014- 018>020-022>024. NC...NONE. WV...FLASH FLOOD WATCH THROUGH SUNDAY MORNING FOR WVZ042>044-507- 508. && $$ SYNOPSIS...NF NEAR TERM...DS/NF SHORT TERM...RAB LONG TERM...JH/RAB AVIATION...DS HYDROLOGY...DS/JH
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1253 PM EDT SAT JUN 20 2015 .SYNOPSIS... SHOWER AND THUNDERSTORM ACTIVITY WILL INCREASE THIS MORNING AND AFTERNOON AS TROPICAL DEPRESSION BILL APPROACHES FROM THE WEST... WITH HEAVY RAIN EXPECTED FOR THIS EVENING INTO TONIGHT. WITH THE SYSTEMS DEPARTURE BY DAWN SUNDAY...ATTENTION TURNS TO UPPER LEVEL RIDGING ACROSS THE PLAINS...WHICH WILL BRING NORTHWESTERLY WINDFLOW ALOFT TO THE MID ATLANTIC. DISTURBANCES EMBEDDED WITHIN THE NORTHWESTERLY FLOW WILL BRING ROUNDS OF THUNDERSTORM ACTIVITY THROUGH THE MIDDLE OF NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1245 PM EDT SATURDAY... THERE WILL BE NO MAJOR CHANGES TO THE FORECAST FOR THE REMAINDER OF THE AFTERNOON. HOWEVER...SOME MINOR ADJUSTMENTS HAVE BEEN MADE. A FEW AREAS ACROSS THE REGION HAVE REACHED TEMPERATURES THAT ARE AT OR A COUPLE OF DEGREES ABOVE THE FORECAST HIGH TEMPERATURE. HOWEVER...THESE SAME LOCATIONS...MAINLY IN THE WEST...ARE IN STORE FOR PLENTY OF CLOUD COVER AND INCREASING CHANCES OF PRECIPITATION THIS AFTERNOON. HAVE RAISED THE EXPECTED HIGHS...BUT BY NOT MUCH ABOVE THE CURRENT READINGS. SHOWERS HAVE STARTED ARRIVING IN THE WEST...FROM THE WEST...AND SOME HAVE ALSO STARTED TO DEVELOP...ALSO IN WESTERN PARTS OF THE REGION. HAVE MADE MINOR ADJUSTMENTS TO THE PRECIPITATION CHANCES IN THIS REGION BASED UPON THE LATEST COVERAGE AND EXPECTED TRENDS THE NEXT COUPLE OF HOURS. AS OF 950 AM EDT SATURDAY... THE OVERALL FORECAST FOR TODAY STILL LOOKS ON TRACK. WE WILL BE MAKING SOME ADJUSTMENTS IN THE NEAR TERM...AND ALSO THE QUANTITY OF PRECIPITATION EXPECTED THROUGH TONIGHT. THE FIRST ADJUSTMENT IS THE TIMING OF THE ARRIVAL OF PRECIPITATION...ESPECIALLY ACROSS THE FAR WESTERN PARTS OF THE REGION. NO PRECIPITATION IS CURRENTLY BEING DETECTED ON RADAR IN THE FORECAST AREA. THIS IS EXPECTED TO CHANGE. LOOKING TO OUR WEST...REGIONAL RADARS ARE DETECTING THE FIRST BAND OF SHOWERS THAT WILL ARRIVE IN THE WEST...AND AS DAYTIME HEATING INCREASES...THESE SHOWERS WILL HAVE A GREATER CHANCE OF HAVING SOME THUNDER AROUND THE TIME THEY ARRIVE. CURRENTLY...THAT TIME LOOKS BETWEEN 1100 AM AND NOON. ADDITIONAL ISOLATED CONVECTION IS ALSO EXPECTED THROUGH THE END OF THE MORNING HOURS JUST IN ADVANCE OF THIS FIRST BAND. THE AFTERNOON FORECAST STILL LOOK ON TRACK WITH THE BULK OF THE PRECIPITATION ARRIVING DURING THE MID TO LATE AFTERNOON...WITH THE GREATEST FOCUS ACROSS THE NORTHWEST PARTS OF THE AREA. REGARDING PRECIPITATION TOTALS....THE LATEST SOLUTION FROM WPC DEPICTS ON AVERAGE ABOUT ANOTHER QUARTER OF A INCH ACROSS MOST OF THE AREA THAT IS CURRENTLY HIGHLIGHTED BY THE FLASH FLOOD WATCH...THUS ADDING GREATER CREDENCE TO THE CONTINUATION OF THE WATCH. NO OTHER SIGNIFICANT CHANGES PLANNED AT THIS TIME. FOR PROVISION OF ADDITIONAL UPPER AIR DATA...THERE WILL BE A SPECIAL 18Z/2PM UPPER AIR WEATHER BALLOON LAUNCH BY THIS OFFICE...WEATHER PERMITTING. AS OF 400 AM EDT SATURDAY... RADAR INDICATING BANDS OF SHOWER ACTIVITY ACROSS KENTUCKY THIS MORNING AS TD BILL MAKES ITS APPROACH UP THE OHIO RIVER VALLEY. RAPID UPDATE WEATHER MODELS SUCH AS THE HRRR AND THE RAP ARE IN GOOD AGREEMENT THAT THE LEADING BANDS WILL ENTER OUR MOUNTAIN EMPIRE/ SOUTHEAST WEST VIRGINIA COUNTIES AROUND SUNRISE...BRINGING SPOTTY SHOWER ACTIVITY. STILL...DEEPER MOISTURE AND INCREASED CLOUD COVER WILL NOT ARRIVE UNTIL AFTERNOON...AND BELIEVE WE WILL STILL HAVE ENOUGH SUNSHINE TO ALLOW FOR SIGNIFICANT HEATING DURING THE MORNING...ESPECIALLY EAST OF THE BLUE RIDGE. AS SUCH...STILL EXPECT SOME SHOWERS TO INTENSIFY INTO THUNDERSTORMS DURING LATE MORNING AND EARLY AFTERNOON...A FEW OF WHICH WILL BECOME STRONG TO SEVERE GIVEN CAPE EXCEEDING 1000 J/KG FOR MUCH OF THE AREA DURING EARLY AFTERNOON...AS WELL AS INCREASING LOW LEVEL WIND SHEAR TOWARD EVENING AS THE CENTER OF BILL PASSES ACROSS SOUTHERN OHIO. OUTSIDE OF SEVERE POTENTIAL...BILL WILL ALSO BRING DEEP TROPICAL MOISTURE...WITH PRECIPITABLE WATER VALUES REACHING 2+ INCHES DURING THE EVENING FOR MUCH OF THE AREA. FACTORING IN OROGRAPHIC LIFT... BELIEVE WE WILL SEE RAINFALL AMOUNTS ON AVERAGE RANGE FROM 1 TO 1.5 INCHES FOR THE BLUE RIDGE WESTWARD...WITH 2 TO 3 INCHES IN A FEW SPOTS...ESPECIALLY WESTERN GREENBRIER COUNTY. FURTHER EAST... RAINFALL AMOUNTS WILL TAPER DOWN TO AROUND A HALF INCH THE PIEDMONT OF NORTH CAROLINA. BUT GIVEN THE DEEP MOISTURE AND INSTABILITY OF THE SYSTEM...COMBINED WITH THE POTENTIAL FOR TRAINING OF CELLS OVER THE SAME LOCATIONS...WILL CONTINUE WITH THE FLASH FLOOD WATCH CURRENTLY IN EFFECT. BILL IS A FAST MOVING SYSTEM...AND AS QUICKLY AS IT ARRIVES...WE WILL SEE RAINFALL BEGIN TO DIMINISH QUICKLY AFTER 2 AM SUNDAY AS THE MAIN ENERGY OF THE SYSTEM EXITS TO THE EAST. BY SUNRISE SUNDAY... SHOULD ONLY SEE SPOTTY UPSLOPE SHOWER ACTIVITY ACROSS THE WESTERN RIDGES...AND PERHAPS A FEW SHOWERS ACROSS THE PIEDMONT. && .SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/... AS OF 415 AM EDT SATURDAY... CONSIDERABLY QUIET WEATHER EXPECTED AT THE BEGINNING OF THIS PERIOD AS THE REMNANTS OF T.S. BILL ARE LOCATED IN THE DCA/BWI AREA AT THE 12Z SUN...RAPIDLY ACCELERATING OFF THE NJ/NY COAST BY SUNDAY EVENING. NO ADDITIONAL CONCERNS FROM BILL THIS PERIOD. HOWEVER...THE PERIOD WILL BE QUITE UNSETTLED WITH DAILY ROUNDS OF CONVECTION LIKELY AND INCREASING POTENTIAL FOR NORTHWEST FLOW MCS DURING THIS TIME FRAME. AS A RESULT...THERE WILL BE MULTIPLE CHANCES FOR STRONG TO SEVERE THUNDERSTORMS THIS TIME FRAME...WITH AN EVEN GREATER CHANCE FOR SUCH DURING THE LONG TERM PERIOD. ONCE BILL DEPARTS THE AREA EARLY SUNDAY...THE MEAN JET WILL BE LOCATED ACROSS THE NORTHERN STATES ON THE NORTH SIDE OF A BROAD SUBTROPICAL UPPER RIDGE CENTERED IN THE DESERT SOUTHWEST...BUT ACTUALLY EXTENDING EASTWARD AND WESTWARD FROM THIS LOCATION ACROSS ALL SOUTHERN STATES. AS THE WEEK PROGRESSES...THE UPPER RIDGE WILL AMPLIFY ACROSS THE WESTERN STATES...RESULTING IN DECREASING HEIGHTS ACROSS THE EASTERN U.S. AS TROUGHING DEVELOPS VICINITY OF THE GREAT LAKES. THIS WILL LEAVE OUR REGION AMIDST AN INCREASINGLY ACTIVE AND UNSTABLE NORTHWEST FLOW ALOFT. FOR SUN/SUN EVENING...A SHORT WAVE WILL BE TRACKING ON THE HEELS EASTWARD ACROSS THE OH VALLEY ON THE HEELS OF THE REMNANTS OF T.S. BILL. A VERY UNSTABLE AIR MASS WILL RESIDE ACROSS THE OH VALLEY AS THIS DISTURBANCE TRACKS THROUGH. SPC HAS ALREADY OUTLOOKED A WEST-EAST ORIENTED SLIGHT RISK AREA ACROSS THE OH VALLEY INTO PA...WITH A MARGINAL RISK SURROUNDING THIS TO THE SOUTH. IF AN MCS WERE ABLE TO GET GOING AS APPEARS POSSIBLE SUN AFTERNOON...THE TRAJECTORY WOULD CARRY THE REMNANTS OF THIS SOUTHEAST INTO OUR REGION BY EVENING BEFORE IT DISSIPATES AS IT MOVES TOWARD THE UPPER RIDGE TO THE SOUTH. MAIN THREAT WOULD BE DAMAGING WINDS AS IS COMMON WITH THIS TYPE OF SYSTEM. MON APPEARS TO BE THE QUIETEST DAY OF THE SHORT TERM AS THE AFOREMENTIONED SHORT WAVE TRACKS EAST AND THE UPPER RIDGE ACROSS THE CENTRAL U.S. EXTENDS BRIEFLY EASTWARD TUE-WED. HOWEVER...A WEAK REMNANT BAROCLINIC ZONE WILL LINGER ACROSS THE SW/SC/SE PART OF THE CWA AND COULD WELL BE THE FOCUS FOR SCATTERED AFTERNOON/EVENING THUNDERSTORMS...THUS HAVE INDICATED CHANCE POPS IN THIS AREA AS A RESULT...WITH LOWER POPS TO THE NORTH. TUE PROMISES TO BE MORE ACTIVE AS YET ANOTHER SHORT WAVE TRACKS ACROSS THE GREAT LAKES INTO THE NE STATES AS UPPER HEIGHTS LOWER IN RESPONSE TO THE AMPLIFICATION OF THE RIDGE IN THE WESTERN U.S. AGAIN...ANY THUNDERSTORMS THAT DEVELOP ACROSS THE OH VALLEY WILL HAVE THE CHANCE TO TRACK SOUTHEAST TOWARD OUR REGION DURING THE AFTERNOON/EVENING...AND AN EVEN BETTER CHANCE OF DOING SO TUE THAN ON SUN. THERE WILL ALSO BE A CONCERN FOR HEAT DURING THIS TIME FRAME. WITH WESTERLY SFC FLOW AND THE UPPER RIDGE JUST TO OUR SOUTH...POCKETS OF +20 TO +22C CREEP INTO MUCH OF THE CWA SUN-TUE...BUT ON TUE...EVEN POCKETS OF +25C CREEP INTO THE PIEDMONT PER GFS...ONLY +23 ON THE ECMWF/CANADIAN. THIS WILL CERTAINLY SUPPORT TEMPERATURES WELL INTO THE 90S...UPPER 90S PIEDMONT. AS OF NOW...HEIGHT INDICES REMAIN BELOW 100...BUT LATER RUNS OF THE MODELS MAY DICTATE THE NEED TO CONSIDER HEAT ADVISORIES ACROSS THE PIEDMONT...ESPECIALLY TUE. AT ANY RATE...IT WILL BE HOT AND HUMID THROUGHOUT THE PERIOD. ANY SIGNIFICANT COOLING WILL HAVE TO WAIT UNTIL THE UPPER TROUGH DEEPENS ACROSS THE EASTERN U.S...WHICH IS NOT PROGGED TO TAKE PLACE UNTIL THE END OF THE WEEK INTO NEXT WEEKEND. FOR NOW...HAVE GONE WITH A MIDDLE OF THE ROAD APPROACH ON MAX TEMPS...OPTING NOT TO ADVERTISE THE UPPER 90 TO LOW 100 READINGS INDICATED BY THE GFS ACROSS THE PIEDMONT. && .LONG TERM /WEDNESDAY THROUGH FRIDAY/... AS OF 430 AM EDT SATURDAY... UNSTABLE PATTERN AND POTENTIAL FOR MCS THUNDERSTORM SYSTEMS INCREASES THROUGH THE PERIOD AS NORTHWEST FLOW ALOFT STRENGTHS ACROSS THE REGION IN RESPONSE TO AMPLIFICATION OF THE UPPER FLOW WITH A HIGH AMPLITUDE UPPER RIDGE EXPECTED TO DEVELOP ACROSS THE WESTERN U.S. BY NEXT WEEKEND AND AN EQUALLY DEEP UPPER TROUGH EXPECTED TO EVOLVE ACROSS THE GREAT LAKES AND EASTERN U.S...WELL INTO THE SOUTHEAST STATES IN FACT. THIS COULD EVENTUALLY SERVE TO PUSH THE GREATEST THUNDERSTORM THREAT FURTHER SOUTH INTO AL/GA/SC/FL WITH TIME...BUT FOR THIS TIME FRAME...WE WILL BE PRETTY MUCH CENTERED RIGHT IN THE MIDDLE OF A VERY ACTIVE BAROCLINIC ZONE. ALL MODELS BROAD BRUSH HIGH POPS/QPF ACROSS THE REGION WITH DAILY THUNDERSTORMS THROUGH THIS ENTIRE PERIOD...WITH THE GREATEST COVERAGE ACROSS THE WEST. REALLY CANT ARGUE WITH THIS GIVEN THE PATTERN. THUS...HAVE ADVERTISED CHANCE TO HIGH CHANCE POPS AND IN A FEW CASES 60 PERCENT POPS EACH DAY THROUGH THE PERIOD...WITH A DEFINITE DIURNAL SWING TO THE POPS...HIGHEST IN THE AFTERNOON/EVENINGS DURING PEAK HEATING. WITH RESPECT TO TEMPERATURES...WE SHOULD SEE A VERY SLOW COOLING TREND AS UPPER HEIGHTS LOWER DURING THE LATER HALF OF THE WEEK IN RESPONSE TO THE DEEPENING EASTERN U.S. TROUGH AS WELL AS INCREASING CLOUDS/PRECIPITATION. 850MB TEMPS SHOULD FINALLY DROP BELOW +20C BY THE END OF THE WEEK AS THE POCKET OF +20C AND GREATER 850MB TEMPS SINKS SOUTHWARD INTO THE SOUTHEAST STATE. IT WILL REMAIN VERY HUMID...HOWEVER...WITH DEWPOINTS HOVERING NEAR 70 THROUGHOUT THE PERIOD UNTIL THE WEEKEND...WHEN THEY SHOULD DROP BACK A FEW DEGREES INTO THE 60S. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... AS OF 745 AM EDT SATURDAY... TD BILL APPROACHES FROM THE OHIO RIVER VALLEY...WITH FEEDER BANDS ALREADY EVIDENT ACROSS KY/WV AND WESTERN WV. THESE WILL INCREASE WITH DAYTIME HEATING. ANY FOG WILL BURN OFF QUICKLY SHORTLY AFTER SUNRISE. RAPID UPDATE MODELS INDICATE THAT SHOWER ACTIVITY WILL INCREASE THROUGH THE MORNING ACROSS THE MOUNTAINS AS BILL APPROACHES. BELIEVE WE WILL SEE ENOUGH HEATING TAKE PLACE BEFORE THE INCREASED CLOUD COVER ASSOCIATED WITH BILL ARRIVES THAT SOME OF THE SHOWERS WILL INTENSIFY INTO THUNDERSTORMS. HAVE ENOUGH CONFIDENCE...WITH PWATS RAMPING UP TO NEARLY TWO INCHES...COUPLED WITH INCREASING SHEAR AND INSTABILITY ALOFT...THAT HAVE ENTERED THUNDERSTORMS INTO ALL TAFS FOR AFTERNOON AND EARLY EVENING. THESE STORMS MAY BE STRONG AND MAY PRODUCE GUSTY WINDS. THE MAIN ENERGY ASSOCIATED WITH BILL WILL PASS ACROSS THE AREA DURING THE 21/00Z TO 21/06Z TIMEFRAME... RESULTING IN MODERATE TO HEAVY RAIN ALONG WITH REDUCED CEILINGS AND VISIBILITY. BILL IS A FAST MOVING SYSTEM...SO CONDITIONS WILL IMPROVE FROM WEST TO EAST AFTER 21/06Z. SOMEWHAT DRIER AIR LOOKS TO ARRIVE LATE IN THE WEEKEND INTO EARLY NEXT WEEK...BUT IMPULSES TRACKING SOUTHEAST FROM THE UPPER MIDWEST MAY BRING A COUPLE ADDITIONAL ROUNDS OF SHOWERS/STORMS AND POSSIBLE SUB-VFR CONDITIONS AS THE WEEK PROGRESSES. && .HYDROLOGY... THE REMNANT LOW OF ONCE TROPICAL STORM BILL WILL PASS JUST NORTH OF THE AREA SATURDAY NIGHT. DEEP TROPICAL MOISTURE ASSOCIATED WITH THIS SYSTEM WILL COMBINE WITH A RESIDUAL FRONT ACROSS THE AREA TO POSSIBLY PRODUCE MORE WIDESPREAD SHOWERS AND STORMS TODAY...AND MORE IN THE WAY OF STEADIER HEAVIER RAINFALL SATURDAY NIGHT OVER THE MOUNTAINS. A GENERAL 1 TO 3 INCHES OF RAIN IS EXPECTED WITH LOCALLY HIGHER TOTALS WHERE HEAVIER RATES WITH EMBEDDED CONVECTION OCCURS. THIS LOOKS MOST LIKELY TO OCCUR OVER PARTS OF SOUTHEAST WEST VIRGINIA AS WELL AS THE VIRGINIA HIGHLANDS AT THIS POINT. ALTHOUGH RAINFALL HAS BEEN RATHER SPOTTY IN THE LAST FEW DAYS...SOME LOCATIONS HAVE RECEIVED AS MUCH AS 3 INCHES MAKING THOSE AREAS MORE PRONE TO FLOODING. THUS GIVEN THE FORECAST RAINFALL AND POTENTIAL FOR MUCH MORE WIDESPREAD MODERATE TO HEAVY RAIN THAN SEEN OF LATE...A FLASH FLOOD WATCH HAS BEEN ISSUED FOR MANY OF THE MOUNTAIN COUNTIES IN VIRGINIA...AND WEST VIRGINIA FOR SATURDAY AFTERNOON INTO THE EARLY MORNING HOURS OF SUNDAY FOR AT LEAST LOCALIZED FLOODING. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...FLASH FLOOD WATCH THROUGH SUNDAY MORNING FOR VAZ007-009>014- 018>020-022>024. NC...NONE. WV...FLASH FLOOD WATCH THROUGH SUNDAY MORNING FOR WVZ042>044-507- 508. && $$ SYNOPSIS...NF NEAR TERM...DS/NF SHORT TERM...RAB LONG TERM...JH/RAB AVIATION...DS HYDROLOGY...DS/JH
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1005 AM EDT SAT JUN 20 2015 .SYNOPSIS... SHOWER AND THUNDERSTORM ACTIVITY WILL INCREASE THIS MORNING AND AFTERNOON AS TROPICAL DEPRESSION BILL APPROACHES FROM THE WEST... WITH HEAVY RAIN EXPECTED FOR THIS EVENING INTO TONIGHT. WITH THE SYSTEMS DEPARTURE BY DAWN SUNDAY...ATTENTION TURNS TO UPPER LEVEL RIDGING ACROSS THE PLAINS...WHICH WILL BRING NORTHWESTERLY WINDFLOW ALOFT TO THE MID ATLANTIC. DISTURBANCES EMBEDDED WITHIN THE NORTHWESTERLY FLOW WILL BRING ROUNDS OF THUNDERSTORM ACTIVITY THROUGH THE MIDDLE OF NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 950 AM EDT SATURDAY... THE OVERALL FORECAST FOR TODAY STILL LOOKS ON TRACK. WE WILL BE MAKING SOME ADJUSTMENTS IN THE NEAR TERM...AND ALSO THE QUANTITY OF PRECIPITATION EXPECTED THROUGH TONIGHT. THE FIRST ADJUSTMENT IS THE TIMING OF THE ARRIVAL OF PRECIPITATION...ESPECIALLY ACROSS THE FAR WESTERN PARTS OF THE REGION. NO PRECIPITATION IS CURRENTLY BEING DETECTED ON RADAR IN THE FORECAST AREA. THIS IS EXPECTED TO CHANGE. LOOKING TO OUR WEST...REGIONAL RADARS ARE DETECTING THE FIRST BAND OF SHOWERS THAT WILL ARRIVE IN THE WEST...AND AS DAYTIME HEATING INCREASES...THESE SHOWERS WILL HAVE A GREATER CHANCE OF HAVING SOME THUNDER AROUND THE TIME THEY ARRIVE. CURRENTLY...THAT TIME LOOKS BETWEEN 1100 AM AND NOON. ADDITIONAL ISOLATED CONVECTION IS ALSO EXPECTED THROUGH THE END OF THE MORNING HOURS JUST IN ADVANCE OF THIS FIRST BAND. THE AFTERNOON FORECAST STILL LOOK ON TRACK WITH THE BULK OF THE PRECIPITATION ARRIVING DURING THE MID TO LATE AFTERNOON...WITH THE GREATEST FOCUS ACROSS THE NORTHWEST PARTS OF THE AREA. REGARDING PRECIPITATION TOTALS....THE LATEST SOLUTION FROM WPC DEPICTS ON AVERAGE ABOUT ANOTHER QUARTER OF A INCH ACROSS MOST OF THE AREA THAT IS CURRENTLY HIGHLIGHTED BY THE FLASH FLOOD WATCH...THUS ADDING GREATER CREDENCE TO THE CONTINUATION OF THE WATCH. NO OTHER SIGNIFICANT CHANGES PLANNED AT THIS TIME. FOR PROVISION OF ADDITIONAL UPPER AIR DATA...THERE WILL BE A SPECIAL 18Z/2PM UPPER AIR WEATHER BALLOON LAUNCH BY THIS OFFICE...WEATHER PERMITTING. AS OF 400 AM EDT SATURDAY... RADAR INDICATING BANDS OF SHOWER ACTIVITY ACROSS KENTUCKY THIS MORNING AS TD BILL MAKES ITS APPROACH UP THE OHIO RIVER VALLEY. RAPID UPDATE WEATHER MODELS SUCH AS THE HRRR AND THE RAP ARE IN GOOD AGREEMENT THAT THE LEADING BANDS WILL ENTER OUR MOUNTAIN EMPIRE/ SOUTHEAST WEST VIRGINIA COUNTIES AROUND SUNRISE...BRINGING SPOTTY SHOWER ACTIVITY. STILL...DEEPER MOISTURE AND INCREASED CLOUD COVER WILL NOT ARRIVE UNTIL AFTERNOON...AND BELIEVE WE WILL STILL HAVE ENOUGH SUNSHINE TO ALLOW FOR SIGNIFICANT HEATING DURING THE MORNING...ESPECIALLY EAST OF THE BLUE RIDGE. AS SUCH...STILL EXPECT SOME SHOWERS TO INTENSIFY INTO THUNDERSTORMS DURING LATE MORNING AND EARLY AFTERNOON...A FEW OF WHICH WILL BECOME STRONG TO SEVERE GIVEN CAPE EXCEEDING 1000 J/KG FOR MUCH OF THE AREA DURING EARLY AFTERNOON...AS WELL AS INCREASING LOW LEVEL WIND SHEAR TOWARD EVENING AS THE CENTER OF BILL PASSES ACROSS SOUTHERN OHIO. OUTSIDE OF SEVERE POTENTIAL...BILL WILL ALSO BRING DEEP TROPICAL MOISTURE...WITH PRECIPITABLE WATER VALUES REACHING 2+ INCHES DURING THE EVENING FOR MUCH OF THE AREA. FACTORING IN OROGRAPHIC LIFT... BELIEVE WE WILL SEE RAINFALL AMOUNTS ON AVERAGE RANGE FROM 1 TO 1.5 INCHES FOR THE BLUE RIDGE WESTWARD...WITH 2 TO 3 INCHES IN A FEW SPOTS...ESPECIALLY WESTERN GREENBRIER COUNTY. FURTHER EAST... RAINFALL AMOUNTS WILL TAPER DOWN TO AROUND A HALF INCH THE PIEDMONT OF NORTH CAROLINA. BUT GIVEN THE DEEP MOISTURE AND INSTABILITY OF THE SYSTEM...COMBINED WITH THE POTENTIAL FOR TRAINING OF CELLS OVER THE SAME LOCATIONS...WILL CONTINUE WITH THE FLASH FLOOD WATCH CURRENTLY IN EFFECT. BILL IS A FAST MOVING SYSTEM...AND AS QUICKLY AS IT ARRIVES...WE WILL SEE RAINFALL BEGIN TO DIMINISH QUICKLY AFTER 2 AM SUNDAY AS THE MAIN ENERGY OF THE SYSTEM EXITS TO THE EAST. BY SUNRISE SUNDAY... SHOULD ONLY SEE SPOTTY UPSLOPE SHOWER ACTIVITY ACROSS THE WESTERN RIDGES...AND PERHAPS A FEW SHOWERS ACROSS THE PIEDMONT. && .SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/... AS OF 415 AM EDT SATURDAY... CONSIDERABLY QUIET WEATHER EXPECTED AT THE BEGINNING OF THIS PERIOD AS THE REMNANTS OF T.S. BILL ARE LOCATED IN THE DCA/BWI AREA AT THE 12Z SUN...RAPIDLY ACCELERATING OFF THE NJ/NY COAST BY SUNDAY EVENING. NO ADDITIONAL CONCERNS FROM BILL THIS PERIOD. HOWEVER...THE PERIOD WILL BE QUITE UNSETTLED WITH DAILY ROUNDS OF CONVECTION LIKELY AND INCREASING POTENTIAL FOR NORTHWEST FLOW MCS DURING THIS TIME FRAME. AS A RESULT...THERE WILL BE MULTIPLE CHANCES FOR STRONG TO SEVERE THUNDERSTORMS THIS TIME FRAME...WITH AN EVEN GREATER CHANCE FOR SUCH DURING THE LONG TERM PERIOD. ONCE BILL DEPARTS THE AREA EARLY SUNDAY...THE MEAN JET WILL BE LOCATED ACROSS THE NORTHERN STATES ON THE NORTH SIDE OF A BROAD SUBTROPICAL UPPER RIDGE CENTERED IN THE DESERT SOUTHWEST...BUT ACTUALLY EXTENDING EASTWARD AND WESTWARD FROM THIS LOCATION ACROSS ALL SOUTHERN STATES. AS THE WEEK PROGRESSES...THE UPPER RIDGE WILL AMPLIFY ACROSS THE WESTERN STATES...RESULTING IN DECREASING HEIGHTS ACROSS THE EASTERN U.S. AS TROUGHING DEVELOPS VICINITY OF THE GREAT LAKES. THIS WILL LEAVE OUR REGION AMIDST AN INCREASINGLY ACTIVE AND UNSTABLE NORTHWEST FLOW ALOFT. FOR SUN/SUN EVENING...A SHORT WAVE WILL BE TRACKING ON THE HEELS EASTWARD ACROSS THE OH VALLEY ON THE HEELS OF THE REMNANTS OF T.S. BILL. A VERY UNSTABLE AIR MASS WILL RESIDE ACROSS THE OH VALLEY AS THIS DISTURBANCE TRACKS THROUGH. SPC HAS ALREADY OUTLOOKED A WEST-EAST ORIENTED SLIGHT RISK AREA ACROSS THE OH VALLEY INTO PA...WITH A MARGINAL RISK SURROUNDING THIS TO THE SOUTH. IF AN MCS WERE ABLE TO GET GOING AS APPEARS POSSIBLE SUN AFTERNOON...THE TRAJECTORY WOULD CARRY THE REMNANTS OF THIS SOUTHEAST INTO OUR REGION BY EVENING BEFORE IT DISSIPATES AS IT MOVES TOWARD THE UPPER RIDGE TO THE SOUTH. MAIN THREAT WOULD BE DAMAGING WINDS AS IS COMMON WITH THIS TYPE OF SYSTEM. MON APPEARS TO BE THE QUIETEST DAY OF THE SHORT TERM AS THE AFOREMENTIONED SHORT WAVE TRACKS EAST AND THE UPPER RIDGE ACROSS THE CENTRAL U.S. EXTENDS BRIEFLY EASTWARD TUE-WED. HOWEVER...A WEAK REMNANT BAROCLINIC ZONE WILL LINGER ACROSS THE SW/SC/SE PART OF THE CWA AND COULD WELL BE THE FOCUS FOR SCATTERED AFTERNOON/EVENING THUNDERSTORMS...THUS HAVE INDICATED CHANCE POPS IN THIS AREA AS A RESULT...WITH LOWER POPS TO THE NORTH. TUE PROMISES TO BE MORE ACTIVE AS YET ANOTHER SHORT WAVE TRACKS ACROSS THE GREAT LAKES INTO THE NE STATES AS UPPER HEIGHTS LOWER IN RESPONSE TO THE AMPLIFICATION OF THE RIDGE IN THE WESTERN U.S. AGAIN...ANY THUNDERSTORMS THAT DEVELOP ACROSS THE OH VALLEY WILL HAVE THE CHANCE TO TRACK SOUTHEAST TOWARD OUR REGION DURING THE AFTERNOON/EVENING...AND AN EVEN BETTER CHANCE OF DOING SO TUE THAN ON SUN. THERE WILL ALSO BE A CONCERN FOR HEAT DURING THIS TIME FRAME. WITH WESTERLY SFC FLOW AND THE UPPER RIDGE JUST TO OUR SOUTH...POCKETS OF +20 TO +22C CREEP INTO MUCH OF THE CWA SUN-TUE...BUT ON TUE...EVEN POCKETS OF +25C CREEP INTO THE PIEDMONT PER GFS...ONLY +23 ON THE ECMWF/CANADIAN. THIS WILL CERTAINLY SUPPORT TEMPERATURES WELL INTO THE 90S...UPPER 90S PIEDMONT. AS OF NOW...HEIGHT INDICES REMAIN BELOW 100...BUT LATER RUNS OF THE MODELS MAY DICTATE THE NEED TO CONSIDER HEAT ADVISORIES ACROSS THE PIEDMONT...ESPECIALLY TUE. AT ANY RATE...IT WILL BE HOT AND HUMID THROUGHOUT THE PERIOD. ANY SIGNIFICANT COOLING WILL HAVE TO WAIT UNTIL THE UPPER TROUGH DEEPENS ACROSS THE EASTERN U.S...WHICH IS NOT PROGGED TO TAKE PLACE UNTIL THE END OF THE WEEK INTO NEXT WEEKEND. FOR NOW...HAVE GONE WITH A MIDDLE OF THE ROAD APPROACH ON MAX TEMPS...OPTING NOT TO ADVERTISE THE UPPER 90 TO LOW 100 READINGS INDICATED BY THE GFS ACROSS THE PIEDMONT. && .LONG TERM /WEDNESDAY THROUGH FRIDAY/... AS OF 430 AM EDT SATURDAY... UNSTABLE PATTERN AND POTENTIAL FOR MCS THUNDERSTORM SYSTEMS INCREASES THROUGH THE PERIOD AS NORTHWEST FLOW ALOFT STRENGTHS ACROSS THE REGION IN RESPONSE TO AMPLIFICATION OF THE UPPER FLOW WITH A HIGH AMPLITUDE UPPER RIDGE EXPECTED TO DEVELOP ACROSS THE WESTERN U.S. BY NEXT WEEKEND AND AN EQUALLY DEEP UPPER TROUGH EXPECTED TO EVOLVE ACROSS THE GREAT LAKES AND EASTERN U.S...WELL INTO THE SOUTHEAST STATES IN FACT. THIS COULD EVENTUALLY SERVE TO PUSH THE GREATEST THUNDERSTORM THREAT FURTHER SOUTH INTO AL/GA/SC/FL WITH TIME...BUT FOR THIS TIME FRAME...WE WILL BE PRETTY MUCH CENTERED RIGHT IN THE MIDDLE OF A VERY ACTIVE BAROCLINIC ZONE. ALL MODELS BROAD BRUSH HIGH POPS/QPF ACROSS THE REGION WITH DAILY THUNDERSTORMS THROUGH THIS ENTIRE PERIOD...WITH THE GREATEST COVERAGE ACROSS THE WEST. REALLY CANT ARGUE WITH THIS GIVEN THE PATTERN. THUS...HAVE ADVERTISED CHANCE TO HIGH CHANCE POPS AND IN A FEW CASES 60 PERCENT POPS EACH DAY THROUGH THE PERIOD...WITH A DEFINITE DIURNAL SWING TO THE POPS...HIGHEST IN THE AFTERNOON/EVENINGS DURING PEAK HEATING. WITH RESPECT TO TEMPERATURES...WE SHOULD SEE A VERY SLOW COOLING TREND AS UPPER HEIGHTS LOWER DURING THE LATER HALF OF THE WEEK IN RESPONSE TO THE DEEPENING EASTERN U.S. TROUGH AS WELL AS INCREASING CLOUDS/PRECIPITATION. 850MB TEMPS SHOULD FINALLY DROP BELOW +20C BY THE END OF THE WEEK AS THE POCKET OF +20C AND GREATER 850MB TEMPS SINKS SOUTHWARD INTO THE SOUTHEAST STATE. IT WILL REMAIN VERY HUMID...HOWEVER...WITH DEWPOINTS HOVERING NEAR 70 THROUGHOUT THE PERIOD UNTIL THE WEEKEND...WHEN THEY SHOULD DROP BACK A FEW DEGREES INTO THE 60S. && .AVIATION /14Z SATURDAY THROUGH WEDNESDAY/... AS OF 745 AM EDT SATURDAY... TD BILL APPROACHES FROM THE OHIO RIVER VALLEY...WITH FEEDER BANDS ALREADY EVIDENT ACROSS KY/WV AND WESTERN WV. THESE WILL INCREASE WITH DAYTIME HEATING. ANY FOG WILL BURN OFF QUICKLY SHORTLY AFTER SUNRISE. RAPID UPDATE MODELS INDICATE THAT SHOWER ACTIVITY WILL INCREASE THROUGH THE MORNING ACROSS THE MOUNTAINS AS BILL APPROACHES. BELIEVE WE WILL SEE ENOUGH HEATING TAKE PLACE BEFORE THE INCREASED CLOUD COVER ASSOCIATED WITH BILL ARRIVES THAT SOME OF THE SHOWERS WILL INTENSIFY INTO THUNDERSTORMS. HAVE ENOUGH CONFIDENCE...WITH PWATS RAMPING UP TO NEARLY TWO INCHES...COUPLED WITH INCREASING SHEAR AND INSTABILITY ALOFT...THAT HAVE ENTERED THUNDERSTORMS INTO ALL TAFS FOR AFTERNOON AND EARLY EVENING. THESE STORMS MAY BE STRONG AND MAY PRODUCE GUSTY WINDS. THE MAIN ENERGY ASSOCIATED WITH BILL WILL PASS ACROSS THE AREA DURING THE 21/00Z TO 21/06Z TIMEFRAME... RESULTING IN MODERATE TO HEAVY RAIN ALONG WITH REDUCED CEILINGS AND VISIBILITY. BILL IS A FAST MOVING SYSTEM...SO CONDITIONS WILL IMPROVE FROM WEST TO EAST AFTER 21/06Z. SOMEWHAT DRIER AIR LOOKS TO ARRIVE LATE IN THE WEEKEND INTO EARLY NEXT WEEK...BUT IMPULSES TRACKING SOUTHEAST FROM THE UPPER MIDWEST MAY BRING A COUPLE ADDITIONAL ROUNDS OF SHOWERS/STORMS AND POSSIBLE SUB-VFR CONDITIONS AS THE WEEK PROGRESSES. && .HYDROLOGY... THE REMNANT LOW OF ONCE TROPICAL STORM BILL WILL PASS JUST NORTH OF THE AREA SATURDAY NIGHT. DEEP TROPICAL MOISTURE ASSOCIATED WITH THIS SYSTEM WILL COMBINE WITH A RESIDUAL FRONT ACROSS THE AREA TO POSSIBLY PRODUCE MORE WIDESPREAD SHOWERS AND STORMS TODAY...AND MORE IN THE WAY OF STEADIER HEAVIER RAINFALL SATURDAY NIGHT OVER THE MOUNTAINS. A GENERAL 1 TO 3 INCHES OF RAIN IS EXPECTED WITH LOCALLY HIGHER TOTALS WHERE HEAVIER RATES WITH EMBEDDED CONVECTION OCCURS. THIS LOOKS MOST LIKELY TO OCCUR OVER PARTS OF SOUTHEAST WEST VIRGINIA AS WELL AS THE VIRGINIA HIGHLANDS AT THIS POINT. ALTHOUGH RAINFALL HAS BEEN RATHER SPOTTY IN THE LAST FEW DAYS...SOME LOCATIONS HAVE RECEIVED AS MUCH AS 3 INCHES MAKING THOSE AREAS MORE PRONE TO FLOODING. THUS GIVEN THE FORECAST RAINFALL AND POTENTIAL FOR MUCH MORE WIDESPREAD MODERATE TO HEAVY RAIN THAN SEEN OF LATE...A FLASH FLOOD WATCH HAS BEEN ISSUED FOR MANY OF THE MOUNTAIN COUNTIES IN VIRGINIA...AND WEST VIRGINIA FOR SATURDAY AFTERNOON INTO THE EARLY MORNING HOURS OF SUNDAY FOR AT LEAST LOCALIZED FLOODING. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...FLASH FLOOD WATCH THROUGH SUNDAY MORNING FOR VAZ007-009>014- 018>020-022>024. NC...NONE. WV...FLASH FLOOD WATCH THROUGH SUNDAY MORNING FOR WVZ042>044-507- 508. && $$ SYNOPSIS...NF NEAR TERM...DS/NF SHORT TERM...RAB LONG TERM...JH/RAB AVIATION...AMS/NF/WP HYDROLOGY...DS/JH
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
745 AM EDT SAT JUN 20 2015 .SYNOPSIS... SHOWER AND THUNDERSTORM ACTIVITY WILL INCREASE THIS MORNING AND AFTERNOON AS TROPICAL DEPRESSION BILL APPROACHES FROM THE WEST... WITH HEAVY RAIN EXPECTED FOR THIS EVENING INTO TONIGHT. WITH THE SYSTEMS DEPARTURE BY DAWN SUNDAY...ATTENTION TURNS TO UPPER LEVEL RIDGING ACROSS THE PLAINS...WHICH WILL BRING NORTHWESTERLY WINDFLOW ALOFT TO THE MID ATLANTIC. DISTURBANCES EMBEDDED WITHIN THE NORTHWESTERLY FLOW WILL BRING ROUNDS OF THUNDERSTORM ACTIVITY THROUGH THE MIDDLE OF NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 400 AM EDT SATURDAY... RADAR INDICATING BANDS OF SHOWER ACTIVITY ACROSS KENTUCKY THIS MORNING AS TD BILL MAKES ITS APPROACH UP THE OHIO RIVER VALLEY. RAPID UPDATE WEATHER MODELS SUCH AS THE HRRR AND THE RAP ARE IN GOOD AGREEMENT THAT THE LEADING BANDS WILL ENTER OUR MOUNTAIN EMPIRE/ SOUTHEAST WEST VIRGINIA COUNTIES AROUND SUNRISE...BRINGING SPOTTY SHOWER ACTIVITY. STILL...DEEPER MOISTURE AND INCREASED CLOUD COVER WILL NOT ARRIVE UNTIL AFTERNOON...AND BELIEVE WE WILL STILL HAVE ENOUGH SUNSHINE TO ALLOW FOR SIGNIFICANT HEATING DURING THE MORNING...ESPECIALLY EAST OF THE BLUE RIDGE. AS SUCH...STILL EXPECT SOME SHOWERS TO INTENSIFY INTO THUNDERSTORMS DURING LATE MORNING AND EARLY AFTERNOON...A FEW OF WHICH WILL BECOME STRONG TO SEVERE GIVEN CAPE EXCEEDING 1000 J/KG FOR MUCH OF THE AREA DURING EARLY AFTERNOON...AS WELL AS INCREASING LOW LEVEL WIND SHEAR TOWARD EVENING AS THE CENTER OF BILL PASSES ACROSS SOUTHERN OHIO. OUTSIDE OF SEVERE POTENTIAL...BILL WILL ALSO BRING DEEP TROPICAL MOISTURE...WITH PRECIPITABLE WATER VALUES REACHING 2+ INCHES DURING THE EVENING FOR MUCH OF THE AREA. FACTORING IN OROGRAPHIC LIFT... BELIEVE WE WILL SEE RAINFALL AMOUNTS ON AVERAGE RANGE FROM 1 TO 1.5 INCHES FOR THE BLUE RIDGE WESTWARD...WITH 2 TO 3 INCHES IN A FEW SPOTS...ESPECIALLY WESTERN GREENBRIER COUNTY. FURTHER EAST... RAINFALL AMOUNTS WILL TAPER DOWN TO AROUND A HALF INCH THE PIEDMONT OF NORTH CAROLINA. BUT GIVEN THE DEEP MOISTURE AND INSTABILITY OF THE SYSTEM...COMBINED WITH THE POTENTIAL FOR TRAINING OF CELLS OVER THE SAME LOCATIONS...WILL CONTINUE WITH THE FLASH FLOOD WATCH CURRENTLY IN EFFECT. BILL IS A FAST MOVING SYSTEM...AND AS QUICKLY AS IT ARRIVES...WE WILL SEE RAINFALL BEGIN TO DIMINISH QUICKLY AFTER 2 AM SUNDAY AS THE MAIN ENERGY OF THE SYSTEM EXITS TO THE EAST. BY SUNRISE SUNDAY... SHOULD ONLY SEE SPOTTY UPSLOPE SHOWER ACTIVITY ACROSS THE WESTERN RIDGES...AND PERHAPS A FEW SHOWERS ACROSS THE PIEDMONT. && .SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/... AS OF 415 AM EDT SATURDAY... CONSIDERABLY QUIET WEATHER EXPECTED AT THE BEGINNING OF THIS PERIOD AS THE REMNANTS OF T.S. BILL ARE LOCATED IN THE DCA/BWI AREA AT THE 12Z SUN...RAPIDLY ACCELERATING OFF THE NJ/NY COAST BY SUNDAY EVENING. NO ADDITIONAL CONCERNS FROM BILL THIS PERIOD. HOWEVER...THE PERIOD WILL BE QUITE UNSETTLED WITH DAILY ROUNDS OF CONVECTION LIKELY AND INCREASING POTENTIAL FOR NORTHWEST FLOW MCS DURING THIS TIME FRAME. AS A RESULT...THERE WILL BE MULTIPLE CHANCES FOR STRONG TO SEVERE THUNDERSTORMS THIS TIME FRAME...WITH AN EVEN GREATER CHANCE FOR SUCH DURING THE LONG TERM PERIOD. ONCE BILL DEPARTS THE AREA EARLY SUNDAY...THE MEAN JET WILL BE LOCATED ACROSS THE NORTHERN STATES ON THE NORTH SIDE OF A BROAD SUBTROPICAL UPPER RIDGE CENTERED IN THE DESERT SOUTHWEST...BUT ACTUALLY EXTENDING EASTWARD AND WESTWARD FROM THIS LOCATION ACROSS ALL SOUTHERN STATES. AS THE WEEK PROGRESSES...THE UPPER RIDGE WILL AMPLIFY ACROSS THE WESTERN STATES...RESULTING IN DECREASING HEIGHTS ACROSS THE EASTERN U.S. AS TROUGHING DEVELOPS VICINITY OF THE GREAT LAKES. THIS WILL LEAVE OUR REGION AMIDST AN INCREASINGLY ACTIVE AND UNSTABLE NORTHWEST FLOW ALOFT. FOR SUN/SUN EVENING...A SHORT WAVE WILL BE TRACKING ON THE HEELS EASTWARD ACROSS THE OH VALLEY ON THE HEELS OF THE REMNANTS OF T.S. BILL. A VERY UNSTABLE AIR MASS WILL RESIDE ACROSS THE OH VALLEY AS THIS DISTURBANCE TRACKS THROUGH. SPC HAS ALREADY OUTLOOKED A WEST-EAST ORIENTED SLIGHT RISK AREA ACROSS THE OH VALLEY INTO PA...WITH A MARGINAL RISK SURROUNDING THIS TO THE SOUTH. IF AN MCS WERE ABLE TO GET GOING AS APPEARS POSSIBLE SUN AFTERNOON...THE TRAJECTORY WOULD CARRY THE REMNANTS OF THIS SOUTHEAST INTO OUR REGION BY EVENING BEFORE IT DISSIPATES AS IT MOVES TOWARD THE UPPER RIDGE TO THE SOUTH. MAIN THREAT WOULD BE DAMAGING WINDS AS IS COMMON WITH THIS TYPE OF SYSTEM. MON APPEARS TO BE THE QUIETEST DAY OF THE SHORT TERM AS THE AFOREMENTIONED SHORT WAVE TRACKS EAST AND THE UPPER RIDGE ACROSS THE CENTRAL U.S. EXTENDS BRIEFLY EASTWARD TUE-WED. HOWEVER...A WEAK REMNANT BAROCLINIC ZONE WILL LINGER ACROSS THE SW/SC/SE PART OF THE CWA AND COULD WELL BE THE FOCUS FOR SCATTERED AFTERNOON/EVENING THUNDERSTORMS...THUS HAVE INDICATED CHANCE POPS IN THIS AREA AS A RESULT...WITH LOWER POPS TO THE NORTH. TUE PROMISES TO BE MORE ACTIVE AS YET ANOTHER SHORT WAVE TRACKS ACROSS THE GREAT LAKES INTO THE NE STATES AS UPPER HEIGHTS LOWER IN RESPONSE TO THE AMPLIFICATION OF THE RIDGE IN THE WESTERN U.S. AGAIN...ANY THUNDERSTORMS THAT DEVELOP ACROSS THE OH VALLEY WILL HAVE THE CHANCE TO TRACK SOUTHEAST TOWARD OUR REGION DURING THE AFTERNOON/EVENING...AND AN EVEN BETTER CHANCE OF DOING SO TUE THAN ON SUN. THERE WILL ALSO BE A CONCERN FOR HEAT DURING THIS TIME FRAME. WITH WESTERLY SFC FLOW AND THE UPPER RIDGE JUST TO OUR SOUTH...POCKETS OF +20 TO +22C CREEP INTO MUCH OF THE CWA SUN-TUE...BUT ON TUE...EVEN POCKETS OF +25C CREEP INTO THE PIEDMONT PER GFS...ONLY +23 ON THE ECMWF/CANADIAN. THIS WILL CERTAINLY SUPPORT TEMPERATURES WELL INTO THE 90S...UPPER 90S PIEDMONT. AS OF NOW...HEIGHT INDICES REMAIN BELOW 100...BUT LATER RUNS OF THE MODELS MAY DICTATE THE NEED TO CONSIDER HEAT ADVISORIES ACROSS THE PIEDMONT...ESPECIALLY TUE. AT ANY RATE...IT WILL BE HOT AND HUMID THROUGHOUT THE PERIOD. ANY SIGNIFICANT COOLING WILL HAVE TO WAIT UNTIL THE UPPER TROUGH DEEPENS ACROSS THE EASTERN U.S...WHICH IS NOT PROGGED TO TAKE PLACE UNTIL THE END OF THE WEEK INTO NEXT WEEKEND. FOR NOW...HAVE GONE WITH A MIDDLE OF THE ROAD APPROACH ON MAX TEMPS...OPTING NOT TO ADVERTISE THE UPPER 90 TO LOW 100 READINGS INDICATED BY THE GFS ACROSS THE PIEDMONT. && .LONG TERM /WEDNESDAY THROUGH FRIDAY/... AS OF 430 AM EDT SATURDAY... UNSTABLE PATTERN AND POTENTIAL FOR MCS THUNDERSTORM SYSTEMS INCREASES THROUGH THE PERIOD AS NORTHWEST FLOW ALOFT STRENGTHS ACROSS THE REGION IN RESPONSE TO AMPLIFICATION OF THE UPPER FLOW WITH A HIGH AMPLITUDE UPPER RIDGE EXPECTED TO DEVELOP ACROSS THE WESTERN U.S. BY NEXT WEEKEND AND AN EQUALLY DEEP UPPER TROUGH EXPECTED TO EVOLVE ACROSS THE GREAT LAKES AND EASTERN U.S...WELL INTO THE SOUTHEAST STATES IN FACT. THIS COULD EVENTUALLY SERVE TO PUSH THE GREATEST THUNDERSTORM THREAT FURTHER SOUTH INTO AL/GA/SC/FL WITH TIME...BUT FOR THIS TIME FRAME...WE WILL BE PRETTY MUCH CENTERED RIGHT IN THE MIDDLE OF A VERY ACTIVE BAROCLINIC ZONE. ALL MODELS BROAD BRUSH HIGH POPS/QPF ACROSS THE REGION WITH DAILY THUNDERSTORMS THROUGH THIS ENTIRE PERIOD...WITH THE GREATEST COVERAGE ACROSS THE WEST. REALLY CANT ARGUE WITH THIS GIVEN THE PATTERN. THUS...HAVE ADVERTISED CHANCE TO HIGH CHANCE POPS AND IN A FEW CASES 60 PERCENT POPS EACH DAY THROUGH THE PERIOD...WITH A DEFINITE DIURNAL SWING TO THE POPS...HIGHEST IN THE AFTERNOON/EVENINGS DURING PEAK HEATING. WITH RESPECT TO TEMPERATURES...WE SHOULD SEE A VERY SLOW COOLING TREND AS UPPER HEIGHTS LOWER DURING THE LATER HALF OF THE WEEK IN RESPONSE TO THE DEEPENING EASTERN U.S. TROUGH AS WELL AS INCREASING CLOUDS/PRECIPITATION. 850MB TEMPS SHOULD FINALLY DROP BELOW +20C BY THE END OF THE WEEK AS THE POCKET OF +20C AND GREATER 850MB TEMPS SINKS SOUTHWARD INTO THE SOUTHEAST STATE. IT WILL REMAIN VERY HUMID...HOWEVER...WITH DEWPOINTS HOVERING NEAR 70 THROUGHOUT THE PERIOD UNTIL THE WEEKEND...WHEN THEY SHOULD DROP BACK A FEW DEGREES INTO THE 60S. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... AS OF 745 AM EDT SATURDAY... TD BILL APPROACHES FROM THE OHIO RIVER VALLEY...WITH FEEDER BANDS ALREADY EVIDENT ACROSS KY/WV AND WESTERN WV. THESE WILL INCREASE WITH DAYTIME HEATING. ANY FOG WILL BURN OFF QUICKLY SHORTLY AFTER SUNRISE. RAPID UPDATE MODELS INDICATE THAT SHOWER ACTIVITY WILL INCREASE THROUGH THE MORNING ACROSS THE MOUNTAINS AS BILL APPROACHES. BELIEVE WE WILL SEE ENOUGH HEATING TAKE PLACE BEFORE THE INCREASED CLOUD COVER ASSOCIATED WITH BILL ARRIVES THAT SOME OF THE SHOWERS WILL INTENSIFY INTO THUNDERSTORMS. HAVE ENOUGH CONFIDENCE...WITH PWATS RAMPING UP TO NEARLY TWO INCHES...COUPLED WITH INCREASING SHEAR AND INSTABILITY ALOFT...THAT HAVE ENTERED THUNDERSTORMS INTO ALL TAFS FOR AFTERNOON AND EARLY EVENING. THESE STORMS MAY BE STRONG AND MAY PRODUCE GUSTY WINDS. THE MAIN ENERGY ASSOCIATED WITH BILL WILL PASS ACROSS THE AREA DURING THE 21/00Z TO 21/06Z TIMEFRAME... RESULTING IN MODERATE TO HEAVY RAIN ALONG WITH REDUCED CEILINGS AND VISIBILITY. BILL IS A FAST MOVING SYSTEM...SO CONDITIONS WILL IMPROVE FROM WEST TO EAST AFTER 21/06Z. SOMEWHAT DRIER AIR LOOKS TO ARRIVE LATE IN THE WEEKEND INTO EARLY NEXT WEEK...BUT IMPULSES TRACKING SOUTHEAST FROM THE UPPER MIDWEST MAY BRING A COUPLE ADDITIONAL ROUNDS OF SHOWERS/STORMS AND POSSIBLE SUB-VFR CONDITIONS AS THE WEEK PROGRESSES. && .HYDROLOGY... THE REMNANT LOW OF ONCE TROPICAL STORM BILL WILL APPROACH THE REGION FROM THE WEST LATER TONIGHT INTO SATURDAY BEFORE PASSING JUST NORTH OF THE AREA SATURDAY NIGHT. DEEP TROPICAL MOISTURE ASSOCIATED WITH THIS SYSTEM WILL COMBINE WITH A RESIDUAL FRONT ACROSS THE AREA TO POSSIBLY PRODUCE MORE WIDESPREAD SHOWERS AND STORMS LATER SATURDAY...AND MORE IN THE WAY OF STEADIER HEAVIER RAINFALL SATURDAY NIGHT OVER THE MOUNTAINS. A GENERAL 1 TO 3 INCHES OF RAIN IS EXPECTED WITH LOCALLY HIGHER TOTALS WHERE HEAVIER RATES WITH EMBEDDED CONVECTION OCCURS. THIS LOOKS MOST LIKELY TO OCCUR OVER PARTS OF SOUTHEAST WEST VIRGINIA AS WELL AS THE VIRGINIA HIGHLANDS AT THIS POINT. ALTHOUGH RAINFALL HAS BEEN RATHER SPOTTY IN THE LAST FEW DAYS...SOME LOCATIONS HAVE RECEIVED AS MUCH AS 3 INCHES MAKING THOSE AREAS MORE PRONE TO FLOODING. THUS GIVEN THE FORECAST RAINFALL AND POTENTIAL FOR MUCH MORE WIDESPREAD MODERATE TO HEAVY RAIN THAN SEEN OF LATE...A FLASH FLOOD WATCH HAS BEEN ISSUED FOR MANY OF THE MOUNTAIN COUNTIES IN VIRGINIA...AND WEST VIRGINIA FOR SATURDAY AFTERNOON INTO THE EARLY MORNING HOURS OF SUNDAY FOR AT LEAST LOCALIZED FLOODING. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...FLASH FLOOD WATCH FROM NOON EDT TODAY THROUGH SUNDAY MORNING FOR VAZ007-009>014-018>020-022>024. NC...NONE. WV...FLASH FLOOD WATCH FROM NOON EDT TODAY THROUGH SUNDAY MORNING FOR WVZ042>044-507-508. && $$ SYNOPSIS...NF NEAR TERM...NF SHORT TERM...RAB LONG TERM...JH/RAB AVIATION...AMS/NF/WP HYDROLOGY...JH
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
454 AM EDT SAT JUN 20 2015 .SYNOPSIS... SHOWER AND THUNDERSTORM ACTIVITY WILL INCREASE THIS MORNING AND AFTERNOON AS TROPICAL DEPRESSION BILL APPROACHES FROM THE WEST... WITH HEAVY RAIN EXPECTED FOR THIS EVENING INTO TONIGHT. WITH THE SYSTEMS DEPARTURE BY DAWN SUNDAY...ATTENTION TURNS TO UPPER LEVEL RIDGING ACROSS THE PLAINS...WHICH WILL BRING NORTHWESTERLY WINDFLOW ALOFT TO THE MID ATLANTIC. DISTURBANCES EMBEDDED WITHIN THE NORTHWESTERLY FLOW WILL BRING ROUNDS OF THUNDERSTORM ACTIVITY THROUGH THE MIDDLE OF NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 400 AM EDT SATURDAY... RADAR INDICATING BANDS OF SHOWER ACTIVITY ACROSS KENTUCKY THIS MORNING AS TD BILL MAKES ITS APPROACH UP THE OHIO RIVER VALLEY. RAPID UPDATE WEATHER MODELS SUCH AS THE HRRR AND THE RAP ARE IN GOOD AGREEMENT THAT THE LEADING BANDS WILL ENTER OUR MOUNTAIN EMPIRE/ SOUTHEAST WEST VIRGINIA COUNTIES AROUND SUNRISE...BRINGING SPOTTY SHOWER ACTIVITY. STILL...DEEPER MOISTURE AND INCREASED CLOUD COVER WILL NOT ARRIVE UNTIL AFTERNOON...AND BELIEVE WE WILL STILL HAVE ENOUGH SUNSHINE TO ALLOW FOR SIGNIFICANT HEATING DURING THE MORNING...ESPECIALLY EAST OF THE BLUE RIDGE. AS SUCH...STILL EXPECT SOME SHOWERS TO INTENSIFY INTO THUNDERSTORMS DURING LATE MORNING AND EARLY AFTERNOON...A FEW OF WHICH WILL BECOME STRONG TO SEVERE GIVEN CAPE EXCEEDING 1000 J/KG FOR MUCH OF THE AREA DURING EARLY AFTERNOON...AS WELL AS INCREASING LOW LEVEL WIND SHEAR TOWARD EVENING AS THE CENTER OF BILL PASSES ACROSS SOUTHERN OHIO. OUTSIDE OF SEVERE POTENTIAL...BILL WILL ALSO BRING DEEP TROPICAL MOISTURE...WITH PRECIPITABLE WATER VALUES REACHING 2+ INCHES DURING THE EVENING FOR MUCH OF THE AREA. FACTORING IN OROGRAPHIC LIFT... BELIEVE WE WILL SEE RAINFALL AMOUNTS ON AVERAGE RANGE FROM 1 TO 1.5 INCHES FOR THE BLUE RIDGE WESTWARD...WITH 2 TO 3 INCHES IN A FEW SPOTS...ESPECIALLY WESTERN GREENBRIER COUNTY. FURTHER EAST... RAINFALL AMOUNTS WILL TAPER DOWN TO AROUND A HALF INCH THE PIEDMONT OF NORTH CAROLINA. BUT GIVEN THE DEEP MOISTURE AND INSTABILITY OF THE SYSTEM...COMBINED WITH THE POTENTIAL FOR TRAINING OF CELLS OVER THE SAME LOCATIONS...WILL CONTINUE WITH THE FLASH FLOOD WATCH CURRENTLY IN EFFECT. BILL IS A FAST MOVING SYSTEM...AND AS QUICKLY AS IT ARRIVES...WE WILL SEE RAINFALL BEGIN TO DIMINISH QUICKLY AFTER 2 AM SUNDAY AS THE MAIN ENERGY OF THE SYSTEM EXITS TO THE EAST. BY SUNRISE SUNDAY... SHOULD ONLY SEE SPOTTY UPSLOPE SHOWER ACTIVITY ACROSS THE WESTERN RIDGES...AND PERHAPS A FEW SHOWERS ACROSS THE PIEDMONT. && .SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/... AS OF 415 AM EDT SATURDAY... CONSIDERABLY QUIET WEATHER EXPECTED AT THE BEGINNING OF THIS PERIOD AS THE REMNANTS OF T.S. BILL ARE LOCATED IN THE DCA/BWI AREA AT THE 12Z SUN...RAPIDLY ACCELERATING OFF THE NJ/NY COAST BY SUNDAY EVENING. NO ADDITIONAL CONCERNS FROM BILL THIS PERIOD. HOWEVER...THE PERIOD WILL BE QUITE UNSETTLED WITH DAILY ROUNDS OF CONVECTION LIKELY AND INCREASING POTENTIAL FOR NORTHWEST FLOW MCS DURING THIS TIME FRAME. AS A RESULT...THERE WILL BE MULTIPLE CHANCES FOR STRONG TO SEVERE THUNDERSTORMS THIS TIME FRAME...WITH AN EVEN GREATER CHANCE FOR SUCH DURING THE LONG TERM PERIOD. ONCE BILL DEPARTS THE AREA EARLY SUNDAY...THE MEAN JET WILL BE LOCATED ACROSS THE NORTHERN STATES ON THE NORTH SIDE OF A BROAD SUBTROPICAL UPPER RIDGE CENTERED IN THE DESERT SOUTHWEST...BUT ACTUALLY EXTENDING EASTWARD AND WESTWARD FROM THIS LOCATION ACROSS ALL SOUTHERN STATES. AS THE WEEK PROGRESSES...THE UPPER RIDGE WILL AMPLIFY ACROSS THE WESTERN STATES...RESULTING IN DECREASING HEIGHTS ACROSS THE EASTERN U.S. AS TROUGHING DEVELOPS VICINITY OF THE GREAT LAKES. THIS WILL LEAVE OUR REGION AMIDST AN INCREASINGLY ACTIVE AND UNSTABLE NORTHWEST FLOW ALOFT. FOR SUN/SUN EVENING...A SHORT WAVE WILL BE TRACKING ON THE HEELS EASTWARD ACROSS THE OH VALLEY ON THE HEELS OF THE REMNANTS OF T.S. BILL. A VERY UNSTABLE AIR MASS WILL RESIDE ACROSS THE OH VALLEY AS THIS DISTURBANCE TRACKS THROUGH. SPC HAS ALREADY OUTLOOKED A WEST-EAST ORIENTED SLIGHT RISK AREA ACROSS THE OH VALLEY INTO PA...WITH A MARGINAL RISK SURROUNDING THIS TO THE SOUTH. IF AN MCS WERE ABLE TO GET GOING AS APPEARS POSSIBLE SUN AFTERNOON...THE TRAJECTORY WOULD CARRY THE REMNANTS OF THIS SOUTHEAST INTO OUR REGION BY EVENING BEFORE IT DISSIPATES AS IT MOVES TOWARD THE UPPER RIDGE TO THE SOUTH. MAIN THREAT WOULD BE DAMAGING WINDS AS IS COMMON WITH THIS TYPE OF SYSTEM. MON APPEARS TO BE THE QUIETEST DAY OF THE SHORT TERM AS THE AFOREMENTIONED SHORT WAVE TRACKS EAST AND THE UPPER RIDGE ACROSS THE CENTRAL U.S. EXTENDS BRIEFLY EASTWARD TUE-WED. HOWEVER...A WEAK REMNANT BAROCLINIC ZONE WILL LINGER ACROSS THE SW/SC/SE PART OF THE CWA AND COULD WELL BE THE FOCUS FOR SCATTERED AFTERNOON/EVENING THUNDERSTORMS...THUS HAVE INDICATED CHANCE POPS IN THIS AREA AS A RESULT...WITH LOWER POPS TO THE NORTH. TUE PROMISES TO BE MORE ACTIVE AS YET ANOTHER SHORT WAVE TRACKS ACROSS THE GREAT LAKES INTO THE NE STATES AS UPPER HEIGHTS LOWER IN RESPONSE TO THE AMPLIFICATION OF THE RIDGE IN THE WESTERN U.S. AGAIN...ANY THUNDERSTORMS THAT DEVELOP ACROSS THE OH VALLEY WILL HAVE THE CHANCE TO TRACK SOUTHEAST TOWARD OUR REGION DURING THE AFTERNOON/EVENING...AND AN EVEN BETTER CHANCE OF DOING SO TUE THAN ON SUN. THERE WILL ALSO BE A CONCERN FOR HEAT DURING THIS TIME FRAME. WITH WESTERLY SFC FLOW AND THE UPPER RIDGE JUST TO OUR SOUTH...POCKETS OF +20 TO +22C CREEP INTO MUCH OF THE CWA SUN-TUE...BUT ON TUE...EVEN POCKETS OF +25C CREEP INTO THE PIEDMONT PER GFS...ONLY +23 ON THE ECMWF/CANADIAN. THIS WILL CERTAINLY SUPPORT TEMPERATURES WELL INTO THE 90S...UPPER 90S PIEDMONT. AS OF NOW...HEIGHT INDICES REMAIN BELOW 100...BUT LATER RUNS OF THE MODELS MAY DICTATE THE NEED TO CONSIDER HEAT ADVISORIES ACROSS THE PIEDMONT...ESPECIALLY TUE. AT ANY RATE...IT WILL BE HOT AND HUMID THROUGHOUT THE PERIOD. ANY SIGNIFICANT COOLING WILL HAVE TO WAIT UNTIL THE UPPER TROUGH DEEPENS ACROSS THE EASTERN U.S...WHICH IS NOT PROGGED TO TAKE PLACE UNTIL THE END OF THE WEEK INTO NEXT WEEKEND. FOR NOW...HAVE GONE WITH A MIDDLE OF THE ROAD APPROACH ON MAX TEMPS...OPTING NOT TO ADVERTISE THE UPPER 90 TO LOW 100 READINGS INDICATED BY THE GFS ACROSS THE PIEDMONT. && .LONG TERM /WEDNESDAY THROUGH FRIDAY/... AS OF 430 AM EDT SATURDAY... UNSTABLE PATTERN AND POTENTIAL FOR MCS THUNDERSTORM SYSTEMS INCREASES THROUGH THE PERIOD AS NORTHWEST FLOW ALOFT STRENGTHS ACROSS THE REGION IN RESPONSE TO AMPLIFICATION OF THE UPPER FLOW WITH A HIGH AMPLITUDE UPPER RIDGE EXPECTED TO DEVELOP ACROSS THE WESTERN U.S. BY NEXT WEEKEND AND AN EQUALLY DEEP UPPER TROUGH EXPECTED TO EVOLVE ACROSS THE GREAT LAKES AND EASTERN U.S...WELL INTO THE SOUTHEAST STATES IN FACT. THIS COULD EVENTUALLY SERVE TO PUSH THE GREATEST THUNDERSTORM THREAT FURTHER SOUTH INTO AL/GA/SC/FL WITH TIME...BUT FOR THIS TIME FRAME...WE WILL BE PRETTY MUCH CENTERED RIGHT IN THE MIDDLE OF A VERY ACTIVE BAROCLINIC ZONE. ALL MODELS BROAD BRUSH HIGH POPS/QPF ACROSS THE REGION WITH DAILY THUNDERSTORMS THROUGH THIS ENTIRE PERIOD...WITH THE GREATEST COVERAGE ACROSS THE WEST. REALLY CANT ARGUE WITH THIS GIVEN THE PATTERN. THUS...HAVE ADVERTISED CHANCE TO HIGH CHANCE POPS AND IN A FEW CASES 60 PERCENT POPS EACH DAY THROUGH THE PERIOD...WITH A DEFINITE DIURNAL SWING TO THE POPS...HIGHEST IN THE AFTERNOON/EVENINGS DURING PEAK HEATING. WITH RESPECT TO TEMPERATURES...WE SHOULD SEE A VERY SLOW COOLING TREND AS UPPER HEIGHTS LOWER DURING THE LATER HALF OF THE WEEK IN RESPONSE TO THE DEEPENING EASTERN U.S. TROUGH AS WELL AS INCREASING CLOUDS/PRECIPITATION. 850MB TEMPS SHOULD FINALLY DROP BELOW +20C BY THE END OF THE WEEK AS THE POCKET OF +20C AND GREATER 850MB TEMPS SINKS SOUTHWARD INTO THE SOUTHEAST STATE. IT WILL REMAIN VERY HUMID...HOWEVER...WITH DEWPOINTS HOVERING NEAR 70 THROUGHOUT THE PERIOD UNTIL THE WEEKEND...WHEN THEY SHOULD DROP BACK A FEW DEGREES INTO THE 60S. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... AS OF 200 AM EDT SATURDAY... SPOTTY SHOWER ACTIVITY WILL PASS ACROSS THE MOUNTAINS OVERNIGHT AS TD BILL APPROACHES UP THE OHIO RIVER VALLEY. WILL SEE A FEW POCKETS OF FOG DEVELOP AND POSSIBLY LOW CLOUDS. ANY FOG WILL BURN OFF QUICKLY SHORTLY AFTER SUNRISE. RAPID UPDATE MODELS INDICATE THAT SHOWER ACTIVITY WILL INCREASE THROUGH THE MORNING ACROSS THE MOUNTAINS AS BILL APPROACHES. BELIEVE WE WILL SEE ENOUGH HEATING TAKE PLACE BEFORE THE INCREASED CLOUD COVER ASSOCIATED WITH BILL ARRIVES THAT SOME OF THE SHOWERS WILL INTENSIFY INTO THUNDERSTORMS. HAVE ENOUGH CONFIDENCE...WITH PWATS RAMPING UP TO NEARLY TWO INCHES...COUPLED WITH INCREASING SHEAR AND INSTABILITY ALOFT...THAT HAVE ENTERED THUNDERSTORMS INTO ALL TAFS FOR AFTERNOON AND EARLY EVENING. THESE STORMS MAY BE STRONG AND MAY PRODUCE GUSTY WINDS. THE MAIN ENERGY ASSOCIATED WITH BILL WILL PASS ACROSS THE AREA DURING THE 21/00Z TO 21/06Z TIMEFRAME... RESULTING IN MODERATE TO HEAVY RAIN ALONG WITH REDUCED CEILINGS AND VISIBILITY. BILL IS A FAST MOVING SYSTEM...SO CONDITIONS WILL IMPROVE FROM WEST TO EAST AFTER 21/06Z. SOMEWHAT DRIER AIR LOOKS TO ARRIVE LATE IN THE WEEKEND INTO EARLY NEXT WEEK...BUT IMPULSES TRACKING SOUTHEAST FROM THE UPPER MIDWEST MAY BRING A COUPLE ADDITIONAL ROUNDS OF SHOWERS/STORMS AND POSSIBLE SUB-VFR CONDITIONS AS THE WEEK PROGRESSES. && .HYDROLOGY... THE REMNANT LOW OF ONCE TROPICAL STORM BILL WILL APPROACH THE REGION FROM THE WEST LATER TONIGHT INTO SATURDAY BEFORE PASSING JUST NORTH OF THE AREA SATURDAY NIGHT. DEEP TROPICAL MOISTURE ASSOCIATED WITH THIS SYSTEM WILL COMBINE WITH A RESIDUAL FRONT ACROSS THE AREA TO POSSIBLY PRODUCE MORE WIDESPREAD SHOWERS AND STORMS LATER SATURDAY...AND MORE IN THE WAY OF STEADIER HEAVIER RAINFALL SATURDAY NIGHT OVER THE MOUNTAINS. A GENERAL 1 TO 3 INCHES OF RAIN IS EXPECTED WITH LOCALLY HIGHER TOTALS WHERE HEAVIER RATES WITH EMBEDDED CONVECTION OCCURS. THIS LOOKS MOST LIKELY TO OCCUR OVER PARTS OF SOUTHEAST WEST VIRGINIA AS WELL AS THE VIRGINIA HIGHLANDS AT THIS POINT. ALTHOUGH RAINFALL HAS BEEN RATHER SPOTTY IN THE LAST FEW DAYS...SOME LOCATIONS HAVE RECEIVED AS MUCH AS 3 INCHES MAKING THOSE AREAS MORE PRONE TO FLOODING. THUS GIVEN THE FORECAST RAINFALL AND POTENTIAL FOR MUCH MORE WIDESPREAD MODERATE TO HEAVY RAIN THAN SEEN OF LATE...A FLASH FLOOD WATCH HAS BEEN ISSUED FOR MANY OF THE MOUNTAIN COUNTIES IN VIRGINIA...AND WEST VIRGINIA FOR SATURDAY AFTERNOON INTO THE EARLY MORNING HOURS OF SUNDAY FOR AT LEAST LOCALIZED FLOODING. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...FLASH FLOOD WATCH FROM NOON EDT TODAY THROUGH SUNDAY MORNING FOR VAZ007-009>014-018>020-022>024. NC...NONE. WV...FLASH FLOOD WATCH FROM NOON EDT TODAY THROUGH SUNDAY MORNING FOR WVZ042>044-507-508. && $$ SYNOPSIS...NF NEAR TERM...NF SHORT TERM...RAB LONG TERM...JH/RAB AVIATION...AMS/NF/WP HYDROLOGY...JH
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
842 PM CDT SAT JUN 20 2015 .UPDATE... THE SHOWERS AND STORMS THIS EVENING REMAIN ANCHORED OVER THE FAR SOUTHERN TIER OF COUNTIES ALONG THE STATELINE. SOME ACTIVITY STILL LINGERS AT MID EVENING OVER SOUTHERN ROCK OVER KENOSHA COUNTY AND THIS WILL STEADILY DIMINISH AND SHIFT SOUTH OF WISCONSIN THIS EVENING. QUIET WEATHER IS EXPECTED ACROSS THE REST OF THE FORECAST AREA TONIGHT. THE APPROACHING SFC COLD FRONT HAS SOME SHOWERS WITH IT EAST NORTHEAST OF LA CROSSE...BUT THEY ARE DISSIPATING. THE FRONT IS EXPECTED TO WEAKEN AS WELL. CAN/T COMPLETELY RULE OUT SOME SHOWERS AS THE FRONT LIMPS THROUGH THE AREA...BUT THE GUIDANCE SAYS IT SHOULD STAY DRY...SO WILL GO THAT ROUTE. && .AVIATION/06Z TAFS/... A LIGHT FLOW WILL COMBINE WITH LINGERING HIGH DEWPOINTS TO RAISE THE RISK OF SOME FOG OVERNIGHT...3 TO 5 MILE STUFF. WE MAY EVEN SEE SOME MVFR CIGS DEVELOP FOR A FEW HOURS JUST PRIOR TO AND FOR A FEW HOURS POST SUNRISE SUNDAY OVER MAINLY SOUTHEAST WISCONSIN. OTHERWISE...MAINLY VFR CONDITIONS DURING THE TAF PERIOD. && .PREV DISCUSSION... /ISSUED 407 PM CDT SAT JUN 20 2015/ SHORT TERM... TONIGHT AND SUNDAY...FORECAST CONFIDENCE IS MEDIUM. CURRENT CONVECTION OVER LAFAYETTE COUNTY SHOULD CONTINUE TO SHIFT EAST SOUTHEAST...POSSIBLY CLIPPING THE FAR SOUTHERN COUNTIES TO THE EAST OVER THE NEXT FEW HOURS. IT MAY END UP SLIDING MORE TO THE SOUTHEAST AND MISSING THESE AREAS. HAVE HIGHER END POPS TO COVER THIS. ALSO MORE SCATTERED SHOWERS AND STORMS OVER THE AREA WILL CONTINUE TO SHIFT EASTWARD OVER THE NEXT FEW HOURS. THIS CONVECTION WAS ELEVATED IN NATURE...DRIVEN BY LOW LEVEL JET WHICH WAS TAPPING ELEVATED CAPES UP TO 1200 J/KG OR SO. DEEP LAYER SHEAR IS AROUND 50 KNOTS...THOUGH EFFECTIVE LAYER SHEAR IS NOT AS STRONG. STILL COULD SEE SOME HAIL AND GUSTY WINDS WITH THE STRONGER STORMS. STILL THINKING THE SEVERE CONVECTION WILL REMAIN OVER EASTERN IOWA INTO NORTHWEST ILLINOIS...WHERE SPC DAY 1 SLIGHT/ENHANCED RISK AREA IS LOCATED. STILL LIKE THE TREND WITH THE LATEST HRRR MODEL RUNS...WITH MORE SCATTERED CONVECTION CONTINUING THROUGH THE AREA THIS EVENING...AS THE LOW LEVEL JET AXIS AND LOW PRESSURE/COLD FRONT MOVE THROUGH. ADJUSTED POPS DOWNWARD TO REFLECT MORE SCATTERED NATURE OF CONVECTION THROUGH THIS EVENING. QUIET WEATHER IS THEN EXPECTED LATER TONIGHT INTO SUNDAY...WITH WEAK HIGH PRESSURE MOVING INTO THE AREA. NAM/GFS SOUNDINGS ARE OVERDONE WITH DEW POINTS DURING THIS TIME...WITH RESULT IN BOGUS MEAN LAYER CAPES. SHOULD SEE SOME LOW CLOUDS MOVE SOUTHWARD INTO NORTHERN AND EASTERN PORTIONS OF THE AREA LATER TONIGHT INTO SUNDAY MORNING...WITH PATCHY FOG. THINGS SHOULD MIX OUT BY AFTERNOON AT THE LATEST...WITH LOWER TO MID 80S INLAND. ONSHORE WINDS SHOULD KEEP LAKESHORE AREAS COOLER. SUNDAY NIGHT THROUGH TUESDAY...FORECAST CONFIDENCE MEDIUM. HIGH PRESSURE WILL MOVE EAST SUN NT WITH LOW PRESSURE ORGANIZING OVER THE MID MO RIVER VALLEY BY 12Z MON. THE ONSET OF LOW TO MID LEVEL WARM...MOIST ADVECTION WILL BRING SMALL CHANCES OF SHOWERS/TSTORMS TO THE WRN CWA BEFORE 12Z. THE SHORTWAVE TROUGH ASSOCIATED WITH THE LOW WILL THEN TRACK ACROSS CENTRAL WI ON MON WITH A 1000 MB LOW REACHING NE WI OR ADJACENT UPPER MI BY 00Z TUE. STRONG LOW TO MID LEVEL WARM...MOIST ADVECTION ON A DEVELOPING LLJ IS EXPECTED FOR MON WITH THE NRN CWA AND CENTRAL WI EXPECTED TO SEE REPEATED ROUNDS OF TSTORMS. A STRONG N-S MLCAPE GRADIENT WILL SET UP OVER THE SRN HALF OF WI WITH STRONG DEEP LAYER AND LOW LEVEL SHEAR AS A 70 KT 500 MB WIND MAXIMUM MOVES EAST ACROSS CENTRAL WI. THE SEVERE POTENTIAL WILL DEPEND ON WHETHER MLCAPE VALUES CAN CLIMB ABOVE 1000 J/KG. A SLIGHT TO ENHANCED RISK IS CURRENTLY FCST BY SPC. SOME SVR STORMS WILL LIKELY OCCUR EVEN WITH LOW CAPE GIVEN THE LIFT AND STRONG WIND SHEAR BUT HIGHER CAPE VALUES WOULD INCREASE THE PROBABILITIES OF MORE SIGNIFICANT SVR STORMS INCLUDING SUPERCELLS AND TORNADOES. ALSO CONCERNED ABOUT FLASH FLOODING TOWARD CENTRAL WI DUE TO REPEATED ROUNDS OF CONVECTION AND PWS OF 1.5-1.7 INCHES. THE CONVECTION AND SVR POTENTIAL WILL CARRY INTO MON EVE WITH THE COLD FROPA. NWLY SFC WINDS TO FOLLOW INTO TUE WITH HIGH PRESSURE BUILDING INTO WI LATER ON TUE. LONG TERM...WEDNESDAY THROUGH SATURDAY...FORECAST CONFIDENCE MEDIUM. CHANCES OF TSTORMS WILL CONTINUE FOR WED AND THU WITH A WEST TO EAST FRONT LOCATED JUST TO THE SOUTH AND AN UPPER TROUGH MOVING INTO THE GREAT LAKES FROM CANADA FOR THU. SLIGHT CHANCES OF THUNDER TO FOLLOW FOR FRI BUT HIGHER FOR SAT AS ANOTHER UPPER TROUGH DIGS SEWD FROM CANADA INTO WI AND IL. SEASONAL TEMPS EXPECTED FOR THE WEEK. AVIATION/00Z TAFS/... LOW PRESSURE AND A COLD FRONT MOVING THROUGH THE AREA THROUGH THIS EVENING WILL BRING SCATTERED SHOWERS AND SOME THUNDERSTORMS. FOR NOW...WILL USE VICINITY THUNDER WORDING IN TAFS DUE TO UNCERTAINTY WITH AREAL COVERAGE. MVFR/IFR VISIBILITIES ARE POSSIBLE IN ANY STORMS. SOUTH WINDS ARE EXPECTED AT MADISON AND WAUKESHA...WITH SOUTHEAST WINDS POSSIBLE AT MILWAUKEE AND KENOSHA INTO THE EARLY EVENING. WINDS WILL SHIFT TO THE NORTHWEST LATER TONIGHT AND REMAIN WEST NORTHWEST ON SUNDAY. SHOULD SEE AN AREA OF MVFR CEILINGS AT TAF SITES LATER TONIGHT INTO SUNDAY MORNING...ALONG WITH MVFR VISIBILITIES WITH LIGHT FOG. VFR CONDITIONS SHOULD RETURN BY SUNDAY AFTERNOON. MARINE... PATCHY FOG IS EXPECTED TO LINGER TONIGHT INTO SUNDAY...WITH DEW POINTS JUST HIGH ENOUGH OVER THE LAKE MICHIGAN WATER TEMPERATURES. NOT EXPECTING ANY DENSE FOG AT THIS TIME. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ UPDATE...DAVIS TONIGHT/SUNDAY AND AVIATION/MARINE...WOOD SUNDAY NIGHT THROUGH SATURDAY...GEHRING
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
407 PM CDT SAT JUN 20 2015 .SHORT TERM... TONIGHT AND SUNDAY...FORECAST CONFIDENCE IS MEDIUM. CURRENT CONVECTION OVER LAFAYETTE COUNTY SHOULD CONTINUE TO SHIFT EAST SOUTHEAST...POSSIBLY CLIPPING THE FAR SOUTHERN COUNTIES TO THE EAST OVER THE NEXT FEW HOURS. IT MAY END UP SLIDING MORE TO THE SOUTHEAST AND MISSING THESE AREAS. HAVE HIGHER END POPS TO COVER THIS. ALSO MORE SCATTERED SHOWERS AND STORMS OVER THE AREA WILL CONTINUE TO SHIFT EASTWARD OVER THE NEXT FEW HOURS. THIS CONVECTION WAS ELEVATED IN NATURE...DRIVEN BY LOW LEVEL JET WHICH WAS TAPPING ELEVATED CAPES UP TO 1200 J/KG OR SO. DEEP LAYER SHEAR IS AROUND 50 KNOTS...THOUGH EFFECTIVE LAYER SHEAR IS NOT AS STRONG. STILL COULD SEE SOME HAIL AND GUSTY WINDS WITH THE STRONGER STORMS. STILL THINKING THE SEVERE CONVECTION WILL REMAIN OVER EASTERN IOWA INTO NORTHWEST ILLINOIS...WHERE SPC DAY 1 SLIGHT/ENHANCED RISK AREA IS LOCATED. STILL LIKE THE TREND WITH THE LATEST HRRR MODEL RUNS...WITH MORE SCATTERED CONVECTION CONTINUING THROUGH THE AREA THIS EVENING...AS THE LOW LEVEL JET AXIS AND LOW PRESSURE/COLD FRONT MOVE THROUGH. ADJUSTED POPS DOWNWARD TO REFLECT MORE SCATTERED NATURE OF CONVECTION THROUGH THIS EVENING. QUIET WEATHER IS THEN EXPECTED LATER TONIGHT INTO SUNDAY...WITH WEAK HIGH PRESSURE MOVING INTO THE AREA. NAM/GFS SOUNDINGS ARE OVERDONE WITH DEW POINTS DURING THIS TIME...WITH RESULT IN BOGUS MEAN LAYER CAPES. SHOULD SEE SOME LOW CLOUDS MOVE SOUTHWARD INTO NORTHERN AND EASTERN PORTIONS OF THE AREA LATER TONIGHT INTO SUNDAY MORNING...WITH PATCHY FOG. THINGS SHOULD MIX OUT BY AFTERNOON AT THE LATEST...WITH LOWER TO MID 80S INLAND. ONSHORE WINDS SHOULD KEEP LAKESHORE AREAS COOLER. SUNDAY NIGHT THROUGH TUESDAY...FORECAST CONFIDENCE MEDIUM. HIGH PRESSURE WILL MOVE EAST SUN NT WITH LOW PRESSURE ORGANIZING OVER THE MID MO RIVER VALLEY BY 12Z MON. THE ONSET OF LOW TO MID LEVEL WARM...MOIST ADVECTION WILL BRING SMALL CHANCES OF SHOWERS/TSTORMS TO THE WRN CWA BEFORE 12Z. THE SHORTWAVE TROUGH ASSOCIATED WITH THE LOW WILL THEN TRACK ACROSS CENTRAL WI ON MON WITH A 1000 MB LOW REACHING NE WI OR ADJACENT UPPER MI BY 00Z TUE. STRONG LOW TO MID LEVEL WARM...MOIST ADVECTION ON A DEVELOPING LLJ IS EXPECTED FOR MON WITH THE NRN CWA AND CENTRAL WI EXPECTED TO SEE REPEATED ROUNDS OF TSTORMS. A STRONG N-S MLCAPE GRADIENT WILL SET UP OVER THE SRN HALF OF WI WITH STRONG DEEP LAYER AND LOW LEVEL SHEAR AS A 70 KT 500 MB WIND MAXIMUM MOVES EAST ACROSS CENTRAL WI. THE SEVERE POTENTIAL WILL DEPEND ON WHETHER MLCAPE VALUES CAN CLIMB ABOVE 1000 J/KG. A SLIGHT TO ENHANCED RISK IS CURRENTLY FCST BY SPC. SOME SVR STORMS WILL LIKELY OCCUR EVEN WITH LOW CAPE GIVEN THE LIFT AND STRONG WIND SHEAR BUT HIGHER CAPE VALUES WOULD INCREASE THE PROBABILITIES OF MORE SIGNIFICANT SVR STORMS INCLUDING SUPERCELLS AND TORNADOES. ALSO CONCERNED ABOUT FLASH FLOODING TOWARD CENTRAL WI DUE TO REPEATED ROUNDS OF CONVECTION AND PWS OF 1.5-1.7 INCHES. THE CONVECTION AND SVR POTENTIAL WILL CARRY INTO MON EVE WITH THE COLD FROPA. NWLY SFC WINDS TO FOLLOW INTO TUE WITH HIGH PRESSURE BUILDING INTO WI LATER ON TUE. .LONG TERM...WEDNESDAY THROUGH SATURDAY...FORECAST CONFIDENCE MEDIUM. CHANCES OF TSTORMS WILL CONTINUE FOR WED AND THU WITH A WEST TO EAST FRONT LOCATED JUST TO THE SOUTH AND AN UPPER TROUGH MOVING INTO THE GREAT LAKES FROM CANADA FOR THU. SLIGHT CHANCES OF THUNDER TO FOLLOW FOR FRI BUT HIGHER FOR SAT AS ANOTHER UPPER TROUGH DIGS SEWD FROM CANADA INTO WI AND IL. SEASONAL TEMPS EXPECTED FOR THE WEEK. && .AVIATION/00Z TAFS/... LOW PRESSURE AND A COLD FRONT MOVING THROUGH THE AREA THROUGH THIS EVENING WILL BRING SCATTERED SHOWERS AND SOME THUNDERSTORMS. FOR NOW...WILL USE VICINITY THUNDER WORDING IN TAFS DUE TO UNCERTAINTY WITH AREAL COVERAGE. MVFR/IFR VISIBILITIES ARE POSSIBLE IN ANY STORMS. SOUTH WINDS ARE EXPECTED AT MADISON AND WAUKESHA...WITH SOUTHEAST WINDS POSSIBLE AT MILWAUKEE AND KENOSHA INTO THE EARLY EVENING. WINDS WILL SHIFT TO THE NORTHWEST LATER TONIGHT AND REMAIN WEST NORTHWEST ON SUNDAY. SHOULD SEE AN AREA OF MVFR CEILINGS AT TAF SITES LATER TONIGHT INTO SUNDAY MORNING...ALONG WITH MVFR VISIBILITIES WITH LIGHT FOG. VFR CONDITIONS SHOULD RETURN BY SUNDAY AFTERNOON. && .MARINE... PATCHY FOG IS EXPECTED TO LINGER TONIGHT INTO SUNDAY...WITH DEW POINTS JUST HIGH ENOUGH OVER THE LAKE MICHIGAN WATER TEMPERATURES. NOT EXPECTING ANY DENSE FOG AT THIS TIME. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ TONIGHT/SUNDAY AND AVIATION/MARINE...WOOD SUNDAY NIGHT THROUGH SATURDAY...GEHRING
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1152 AM CDT SAT JUN 20 2015 .UPDATE... SHOULD SEE SOUTHEAST WIND GUSTS IN THE 20 TO 30 KNOT RANGE SPREAD EAST ACROSS MOST OF THE REST OF SOUTHEAST AND EAST CENTRAL WISCONSIN FOR THE NEXT HOUR OR TWO. THIS IS IN RESPONSE TO A GOOD ISALLOBARIC GRADIENT FROM A WAKE LOW SPREADING ACROSS THE AREA. COULD SEE A FEW GUSTS TO 35 KNOTS. GUSTS ALREADY ENDING IN THE NORTHWESTERN PORTIONS OF THE AREA. LIKE THE TREND WITH THE LATEST HRRR MODEL WITH CONVECTIVE TRENDS LATER THIS AFTERNOON INTO THIS EVENING. IT HAS MOST OF THE STRONG TO SEVERE CONVECTION DEVELOPING IN NORTHEAST IOWA LATER THIS AFTERNOON AND KEEPING IT SOUTHWEST OF THE AREA THIS EVENING. THIS MAKES SENSE...AS THE BEST INSTABILITY AND FORCING FOR UPWARD VERTICAL MOTION FROM THE COLD FRONT ARE IN THAT AREA. THUS...LATEST SPC DAY 1 OUTLOOK HAS BACKED OFF ON THE SLIGHT RISK TO JUST THE FAR SOUTHWEST COUNTIES. THINK OVERALL SEVERE RISK IS SMALL IN THE FORECAST AREA. STILL THINK THERE WILL BE MORE SCATTERED SHOWER AND SOME THUNDERSTORM ACTIVITY ACROSS THE AREA LATER THIS AFTERNOON AND THIS EVENING...AS LOW PRESSURE AND A COLD FRONT MOVES ACROSS THE AREA. AMOUNT OF MEAN LAYER CAPE WILL DEPEND ON HOW MUCH SUN WE CAN GET. FORECAST SOUNDINGS SHOWING MOST OF THIS CAPE IS ROOTED ABOVE 700 MB LEVEL...SO LOW LEVEL CAPE WILL BE MINIMAL. THIS SHOULD LEAD TO MORE SCATTERED TYPE CONVECTION/PRECIPITATION...AND WILL TREND THE POPS IN THIS DIRECTION. && .AVIATION/18Z TAFS/... SOUTHEAST WINDS GUSTING BETWEEN 20 AND 30 KNOTS ARE POSSIBLE AT TAF SITES FOR THE NEXT HOUR OR TWO...BEFORE WEAKENING. OTHERWISE...VFR CONDITIONS ARE EXPECTED THIS AFTERNOON...AS MIDDLE TO HIGH CLOUDS LINGER IN SPOTS. WINDS SHOULD BECOME SOUTH...THOUGH MAY REMAIN SOUTHEAST AT MILWAUKEE AND KENOSHA IF LAKE BREEZE DEVELOPS. LOW PRESSURE AND A COLD FRONT MOVING THROUGH THE AREA THIS EVENING WILL BRING SCATTERED SHOWERS AND SOME THUNDERSTORMS. FOR NOW...WILL USE VICINITY THUNDER WORDING IN TAFS DUE TO SOME UNCERTAINTY WITH AREAL COVERAGE. MVFR/IFR VISIBILITIES ARE POSSIBLE IN ANY STORMS. WINDS WILL SHIFT TO THE NORTHWEST LATER TONIGHT AND REMAIN WEST NORTHWEST ON SUNDAY. SHOULD SEE AN AREA OF MVFR CEILINGS AT TAF SITES LATER TONIGHT INTO SUNDAY MORNING...ALONG WITH MVFR VISIBILITIES WITH LIGHT FOG. VFR CONDITIONS SHOULD RETURN BY SUNDAY AFTERNOON. && .MARINE... SOUTHEAST WINDS WILL GUST BETWEEN 20 AND 30 KNOTS FOR AN HOUR OR TWO...BEFORE DIMINISHING BY MID AFTERNOON. MARINE WEATHER STATEMENT WAS ISSUED TO HIGHLIGHT THESE WINDS. && .PREV DISCUSSION... /ISSUED 551 AM CDT SAT JUN 20 2015/ TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM. MAIN ISSUE REMAINS SEVERE WEATHER CHANCES LATE THIS AFTERNOON AND EVENING. ALL HI-RES/RAPID UPDATE MESO MODELS TAKE CURRENT MCS MOVING THROUGH ERN SOUTH DAKOTA ACROSS SRN MINNESOTA/NRN IOWA AND THEN DIURNALLY WEAKEN IT BY MID-MORNING. ACCOUNTED FOR PCPN FROM THE MCS REMAINS MOVING INTO WESTERN CWA MID TO LATE MORNING. KEY TO EXTENT OF STRONG TO SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING IS WHERE COLD POOL AND DEBRIS CLOUDS FROM MCS ALLOW EFFECTIVE WARM FRONT TO SET UP. STRONG 500 MB FLOW CONTRIBUTES TO 0- 6KM BULK SHEAR IN THE 40-50KT RANGE. MODELS SHOW 850 MB WINDS OF 30 TO 35 KNOTS APPROACHING WESTERN WI AT 18Z THAT HEEL OVER ACROSS THE SOUTH THROUGH THE LATE AFTERNOON INTO EARLY EVENING. IF DEBRIS CLOUDS NOT TOO EXTENSIVE...THIS WILL BRING SURFACE TEMPS UP INTO THE UPPER 70S TO LOWER 80S...WITH SOUTHEAST WINDS HOLDING HIGHS INT EH UPPER 60S TO MID 70S NEAR THE LAKE. CAPE VALUES IN THE 1200 TO 1500 J/KG RANGE. 4 KM SPC WRF...ARW...NMM AND NAM NEST ALL SHOW REDEVELOPMENT OVER EASTERN/NORTHEASTERN IOWA WITH RESULTING MCS SKIMMING FAR SRN WI AS IT MOVES EAST-SOUTHEAST ACROSS IL. NAM...GFS AND ECMWF SIMILAR WITH REDEVELOPMENT A BIT FARTHER NORTH THAT WOULD PLACE MORE OF CWA IN A SEVERE THREAT. WILL FOLLOW BLENDED SOLUTION THAT SUPPORTS SPC SLIGHT RISK ROUGHLY SOUTHWEST OF A DELLS TO PLEASANT PRAIRIE LINE. MODELS TAKE SHOWERS AND STORMS EAST OF CWA BETWEEN 06Z AND 09Z...BUT RESIDUAL CLOUD COVER/MOISTURE AND LACK OF STRONG COLD ADVECTION SHOULD KEEP LOW TEMPERATURES IN THE MID 60S. SUNDAY INTO EARLY MONDAY MORNING...FORECAST CONFIDENCE...MEDIUM. IN THE WAKE OF THE SYSTEM THAT MOVES THROUGH TODAY...SURFACE TO UPPER LEVEL RIDGING WILL MOVE INTO THE REGION WHICH WILL BRING DRY AIR AND SUBSIDENCE IN ALONG WITH IT. HOWEVER...THIS RIDGING WILL BE SHORT LIVED...PARTICULARLY IN THE LOW LEVELS WHERE MOISTURE TRANSPORT WILL BE ON THE INCREASE IN THE OVERNIGHT/EARLY MONDAY MORNING HOURS AS A SURFACE/850MB LOW PROPAGATES EAST ACROSS THE HIGH PLAINS. THIS COULD LEAD TO SOME CONVECTION DEVELOPING ALONG THE NOSE OF THE MOISTURE TRANSPORT AND SURFACE WARM FRONT...WHICH LOOKS LIKE IT WILL BE ADVANCING NORTHWARD THROUGH THE NIGHT. ELEVATED INSTABILITY WILL BE ON THE INCREASE AS SURFACE DEW POINTS START TO CLIMB WITH THE APPROACHING WARM FRONT. WITH THE INCREASING ELEVATED INSTABILITY...DECENT LOW LEVEL LIFT FROM THE MOISTURE TRANSPORT...AND STRONG MID LEVEL WINDS/SHEAR...CAN NOT RULE OUT SOME ISOLATED STRONG TO SEVERE STORMS EARLY MONDAY. THE 20.00Z NAM/GFS/ECMWF HINT AT MCS DEVELOPMENT SOMEWHERE IN THE MINNESOTA/IOWA REGION BEFORE TRACKING EAST INTO WISCONSIN LATER MONDAY MORNING. MONDAY INTO MONDAY NIGHT...FORECAST CONFIDENCE...MEDIUM. THE 20.00Z GUIDANCE HAS COME TOGETHER TO PROVIDE A MORE AMPLIFIED SOLUTION FOR MONDAY WHICH RESULTS IN THE SURFACE LOW/WARM FRONT LIFTING FURTHER NORTH THAN PREVIOUSLY FORECAST. AS IS THE CASE FOR TODAY...MUCH OF THE SEVERE POTENTIAL WILL LINGER ON EARLY MORNING CONVECTION AND HOW MUCH THE SYNOPTIC FLOW CAN ALTER THE ENVIRONMENT IN ITS WAKE. A NUMBER OF FAVORABLE FACTORS LOOK TO BE IN PLACE ON MONDAY FOR THE DEVELOPMENT OF ORGANIZED CONVECTION. THE 20.00Z NAM/GFS/ECMWF ALL SHOW INCREASING 500MB WINDS AS A SHORT WAVE TROUGH PROPAGATES EAST ALONG THE US/CANADIAN BORDER. AT THE SURFACE...A LOW PRESSURE SYSTEM WILL BE MOVING INTO THE WESTERN GREAT LAKES BY LATE AFTERNOON/EARLY EVENING WITH A WARM FRONT EXTENDING WEST TO EAST FROM IT AND A COLD FRONT DROPPING DOWN TO THE SOUTHWEST OF IT. THERE IS SOME UNCERTAINTY WITH HOW FAR NORTH THE LOW TRACKS WITH EACH OF THE THREE MODELS HAVING A SLIGHTLY DIFFERENT PLACEMENT OF THE CENTER OF THE LOW BY 00Z TUESDAY. REGARDLESS...THE TIMING OF THIS FEATURE COMING THROUGH WILL BE IDEAL FOR CONVECTIVE INITIATION ACROSS SOUTHERN WISCONSIN. THIS PATH WILL LIKELY BE DEPENDENT UPON THE EARLY MORNING CONVECTION AND WHERE THAT TRACKS THROUGH. A HIGHLY UNSTABLE ENVIRONMENT IS FORECAST TO DEVELOP DURING THE DAY THOUGH THE 20.00Z NAM & GFS ARE LIKELY TOO HIGH ON ITS INSTABILITY DUE TO THEM HAVING SURFACE DEW POINTS BETWEEN 75F TO 80F. STILL...MODIFIED SOUNDINGS WITH SURFACE DEW POINTS OF AROUND 70F STILL YIELD A FAT CAPE PROFILE WITH MLCAPE VALUES IN THE 3000-4000 J/KG RANGE. THE MOST PRIME AREA FOR SUPERCELL DEVELOPMENT WILL BE IN THE VICINITY OF THE WARM FRONT WHERE THERE WILL BE MORE DIRECTIONAL WIND SHEAR TO COMPLIMENT THE STRONG SPEED SHEAR. 0-1KM WIND SHEAR WILL ALSO BE MAXIMIZED IN THIS WARM FRONT VICINITY AND WILL BE THE MAIN FOCUS FOR ANY POTENTIAL TORNADOES. WE STILL ARE THREE DAYS OUT AND A LOT CAN CHANGE AS THE EVENT APPROACHES...BUT WILL HAVE TO WATCH THIS ONE CLOSELY. TUESDAY THROUGH FRIDAY...FORECAST CONFIDENCE...LOW. THE BOUNDARY WILL THEN SET UP ACROSS IOWA AND NORTHERN ILLINOIS AS THE SYSTEM TRACKS EAST THROUGH THE GREAT LAKES. THE MAIN QUESTION WILL BE WITH HOW FAR NORTH THE BOUNDARY CAN RECOVER THROUGH THE WEEK IN THE ZONAL FLOW ALOFT. GUIDANCE HAS WAVERED BACK AND FORTH ON WHERE TO PLACE IT...BUT SOME TRENDS APPEAR TO BE FAVORING A MORE SOUTHERN PLACEMENT. REGARDLESS...IF ANY CONVECTION CAN MAKE IT INTO THE REGION...IT WILL HAVE TO BE WATCHED FOR SEVERE POTENTIAL AS THE BELT OF STRONG MID LEVEL WINDS REMAINS IN PLACE THROUGH MUCH OF THE WEEK. SOME HEAVY RAINFALL POTENTIAL IS THERE AS WELL...ESPECIALLY IF THE FRONT DOES NOT MEANDER MUCH OVER THIS PERIOD. AVIATION/12Z TAFS/... EXPECT VFR CONDITIONS TO START...WITH THUNDERSTORM COMPLEX OVER MN/NRN IA TO WEAKEN BUT STILL BRING SOME SHOWERS AND A FEW STORMS INTO THE WESTERN FORECAST AREA...THOUGH UNCERTAIN IT WILL REACH KMSN. CHANCES FOR SHOWERS AND STORMS INCREASE THIS AFTERNOON AND TONIGHT AS LOW PRESSURE AND A COLD FRONT CROSS THE REGION. THERE IS A CHANCE FOR SEVERE STORMS ALONG AND SOUTHEAST OF A DELLS TO PLEASANT PRAIRIE LINE...INCLUDING KMSN. ALL TAF SITES WILL LIKELY SEE STORMS WITH GUSTY WINDS AND HEAVY RAIN AT TIMES...WITH MVFR CIGS AND VSBYS. MODEL GUIDANCE HINTING AT IFR CIGS DROPPING IN BEHIND LOW AFTER 06Z THROUGH 12Z SUNDAY...BUT WILL TREND WITH GFS FORECAST SOUNDINGS THAT KEEP CIGS AT MVFR LEVELS. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ UPDATE...WOOD TODAY/TONIGHT AND AVIATION/MARINE...REM SUNDAY THROUGH FRIDAY...HALBACH
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
840 PM CDT FRI JUN 19 2015 .UPDATE... A VERY QUIET AND SEASONABLY COOL NIGHT CAN BE EXPECTED ACROSS SOUTHERN WISCONSIN TONIGHT. LOWS ARE ON TRACK TO DIP INTO THE LOWER AND MID 50S. I CAN/T REALLY OFFER MUCH INSIGHT INTO HOW THINGS WILL PROGRESS TOMORROW AS MUCH DEPENDS ON HOW THINGS PROGRESS TONIGHT INTO TOMORROW MORNING. THE CONVECTION OVER SOUTHWEST MN THIS EVENING WILL FADE QUICKLY...BUT THE LINE OF STORMS OVER THE DAKOTAS IS STILL PROGD BY THE HRRR TO REACH THE MS RIVER...LIKELY IN A RAPIDLY DIMINISHING PHASE...BY MID MORNING TOMORROW. THIS SHOULD CONTINUE TO FIZZLE OUT WITH REDEVELOPMENT EXPECTED IN THE AFTERNOON. IT/S QUITE POSSIBLE THE DEBRIS AND COLD POOL LEFT FROM THE MORNING ACTIVITY WILL KEEP THE FOCUS FOR NEW CONVECTION MAINLY SOUTH OF WISCONSIN TOMORROW. BUT...WE CAN/T BE CERTAIN ABOUT IT YET. FOR THE DETAILS ON THE SETUP...SEE THE PREVIOUS DISCUSSION BELOW. && .AVIATION/06Z TAFS/... VFR CONDITIONS ARE EXPECTED THROUGH AT LEAST 00Z SUN. THUNDERSTORM CHANCES INCREASE AT KMSN BY ABOUT 20-21Z SATURDAY AND AROUND 00Z SUN FOR KMKE/KUES/KENW AS A LOW PRESSURE SYSTEM AND COLD FRONT APPROACH. SOME OF THE GUIDANCE IS SUGGESTING A PERIOD OF MVFR CIGS MOVING INTO SOUTHERN WISCONSIN LATER SATURDAY EVENING...OR 02-05Z SUN...IN THE WAKE OF THE PASSING COLD FRONT. IT LOOKS LIKE IT MAY PERSIST INTO SUNDAY MORNING IF IT OCCURS. CONFIDENCE ISN/T VERY HIGH IN THAT SCENARIO...ESPECIALLY THIS TIME OF YEAR. && .PREV DISCUSSION... /ISSUED 325 PM CDT FRI JUN 19 2015/ TONIGHT AND SATURDAY...FORECAST CONFIDENCE IS MEDIUM. MODELS ARE IN GOOD AGREEMENT FOR TONIGHT...TAKING HIGH PRESSURE EAST OF THE REGION. QUIET WEATHER IS EXPECTED ACROSS THE AREA. MIDDLE TO HIGH CLOUDS WILL GRADUALLY INCREASE...AS DECAYING MESOSCALE CONVECTIVE SYSTEM MOVES EASTWARD INTO WESTERN WISCONSIN. LOWS SHOULD REMAIN IN THE LOWER TO MID 50S ACROSS THE AREA...NEAR CONSENSUS OF SHORT TERM MODELS. MAIN ISSUE WILL BE SEVERE WEATHER CHANCES SATURDAY AFTERNOON AND EVENING. LOW LEVEL WARM AIR ADVECTION RAMPS UP ON THE MODELS...BRINGING MID TO UPPER 60S FAHRENHEIT DEW POINTS BY SATURDAY AFTERNOON. SURFACE LOW PRESSURE AND COLD FRONT MOVES SOUTHEASTWARD TOWARD THE AREA DURING THE AFTERNOON...PER GFS/CANADIAN/ECMWF MODELS. THE NAM IS FURTHER NORTH WITH THE LOW TRACK...WHICH MAY BE AN OUTLIER SOLUTION. THIS TREND TO THE SOUTHWEST IS REFLECTED IN THE HRRR MODEL OUTPUT...WHICH KEEPS BULK OF CONVECTION JUST SOUTHWEST OF THE AREA. WRF/ARW AND NMM SOLUTIONS KEEP THE SOUTHWEST HALF OF THE AREA WITHIN THE LINE OF CONVECTION LATE IN THE AFTERNOON. THIS TRENDS TOWARD THE LATEST SPC DAY 2 OUTLOOK...WHICH HAS THE SOUTHWEST HALF OF THE AREA IN A SLIGHT RISK. FORECAST SOUNDINGS DO SHOW STRONG DEEP LAYER BULK SHEAR...WITH MEAN LAYER CAPES DEPENDENT ON HOW MUCH MIDDLE TO HIGH CLOUDS LIMIT DAYTIME HEATING. BULK OF CAPE ABOVE 700 MB LEVEL IN THE AFTERNOON...WITH MODEST UPWARD VERTICAL MOTION AHEAD OF THE LOW AND FRONT. THUS...SOME UNCERTAINTY HERE FOR SEVERE CONVECTION. KEPT LIKELY POPS FOR THUNDER ACROSS THE NORTHWEST HALF OF THE AREA BY LATE AFTERNOON...WITH LOWER POPS TO THE SOUTHEAST. KEPT UPPER 70S NORTH AND LOWER 80S SOUTH...WITH COOLER TEMPERATURES NEAR THE LAKE WITH A LAKE BREEZE LATE IN THE DAY. SATURDAY NIGHT THROUGH MONDAY...FORECAST CONFIDENCE...MEDIUM THUNDERSTORMS WITH ABOVE MENTIONED SEVERE RISK WILL LIKELY BE ONGOING BY SATURDAY EVENING...EXITING THE SOUTHEAST BY LATE EVENING AS THE COLD FRONT PUSHES THROUGH SOUTHERN WISCONSIN. TAPERED POPS TO DRY BY LATER IN THE NIGHT AS HIGH PRESSURE MOVES IN BEHIND THE FRONT. SHOULD BE DRY SUNDAY UNDER THE HIGH. THERE WILL BE SOME MOISTURE RETURN FROM THE SOUTHWEST BY SUNDAY NIGHT AS THE HIGH SCOOTS EASTWARD...WITH SHOWER/STORM CHANCES RETURNING AFTER MIDNIGHT AND PERSISTING INTO MONDAY AS A SHORTWAVE MOVES THROUGH. SHOULD SEE HIGH TEMPS NEAR TO A COUPLE DEGREES ABOVE NORMAL SUNDAY AND MONDAY. THERE IS LESS CERTAINTY WITH TEMPS MONDAY THOUGH GIVEN THE CONVECTIVE POTENTIAL. TUESDAY THROUGH FRIDAY...FORECAST CONFIDENCE...MEDIUM LOOKS MAINLY DRY TUESDAY AS HIGH PRESSURE BRIEFLY MOVES THROUGH...THOUGH KEPT SOME LOWER POPS FOR NOW UNTIL MODELS SETTLE ON THIS SOLUTION. HAVE SHOWER/STORM CHANCES GOING FOR TUESDAY THROUGH FRIDAY...AS MODELS CONTINUE TO SHOW A SERIES OF WAVES MOVING THROUGH MAINLY ZONAL FLOW. BIGGEST ISSUES DURING THIS PERIOD ARE TIMING OF INDIVIDUAL WAVES AND WHERE A FRONTAL BOUNDARY SETS UP...RESULTING IN MODEL DIFFERENCES IN TEMPS AND INSTABILITY. STUCK PRETTY CLOSE TO A CONSENSUS OF MODELS GIVEN THE UNCERTAINTY. AVIATION/00Z TAFS/....AVIATION/00Z TAFS/... VFR CONDITIONS ARE EXPECTED TONIGHT AND SATURDAY ACROSS TAF SITES. HIGH PRESSURE WILL SLIDE EAST OF THE REGION TONIGHT. MAINLY LIGHT EAST/NORTHEAST WINDS WILL GRADUALLY SHIFT SOUTHEAST LATER TONIGHT. MAY SEE LIGHT FOG WITH MVFR VISIBILITIES AT THE EASTERN SITES BETWEEN 09Z AND 13Z SATURDAY. LEFT OUT OF TAFS FOR NOW DUE TO UNCERTAINTY IN AREAL COVERAGE. WINDS WILL SHIFT TO THE SOUTH/SOUTHWEST ON SATURDAY...INCREASING IN SPEED DURING THE AFTERNOON. WINDS MAY REMAIN SOUTHEAST NEAR MILWAUKEE AND KENOSHA IN THE AFTERNOON WITH LAKE BREEZE. SHOWERS AND THUNDERSTORMS MAY AFFECT MADISON LATE IN THE DAY. MOST OF THE ACTIVITY SHOULD OCCUR SATURDAY EVENING...AS LOW PRESSURE AND A COLD FRONT MOVES SOUTHEAST THROUGH THE AREA. POTENTIAL FOR SEVERE STORMS IS MORE UNCERTAIN AT TAF SITES. BEST CHANCES WOULD BE AT MADISON IN THE LATE AFTERNOON AND EARLY EVENING. MVFR CEILINGS AND IFR VISIBILITIES ARE POSSIBLE IN ANY STORMS. MARINE... DEW POINTS IN THE 55 TO 60 DEGREE FAHRENHEIT RANGE MOVING OVER THE COOL LAKE MICHIGAN WATERS SHOULD BRING AT LEAST PATCHY FOG SATURDAY AFTERNOON...PERHAPS INTO SATURDAY NIGHT. WINDS WILL BE RELATIVELY LIGHT DURING THIS TIME...SHIFTING NORTHWEST TOWARD SUNDAY MORNING. DENSE FOG IS NOT EXPECTED AT THIS TIME. BEACHES... MODERATE SWIM RISK REMAINS INTO EARLY THIS EVENING ACROSS BEACHES IN MILWAUKEE COUNTY AND SOUTHWARD. NORTHEAST WINDS WILL WEAKEN BY EARLY EVENING. UNTIL THEN...BREAKING WAVES AND CURRENTS ARE EXPECTED. SWIMMERS ARE ADVISED TO STAY AWAY FROM DANGEROUS AREAS LIKE PIERS...BREAKWALLS AND RIVER OUTLETS. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ UPDATE...DAVIS TONIGHT/SATURDAY AND AVIATION/MARINE...WOOD SATURDAY NIGHT THROUGH FRIDAY...DDV
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
325 PM CDT FRI JUN 19 2015 .TONIGHT AND SATURDAY...FORECAST CONFIDENCE IS MEDIUM. MODELS ARE IN GOOD AGREEMENT FOR TONIGHT...TAKING HIGH PRESSURE EAST OF THE REGION. QUIET WEATHER IS EXPECTED ACROSS THE AREA. MIDDLE TO HIGH CLOUDS WILL GRADUALLY INCREASE...AS DECAYING MESOSCALE CONVECTIVE SYSTEM MOVES EASTWARD INTO WESTERN WISCONSIN. LOWS SHOULD REMAIN IN THE LOWER TO MID 50S ACROSS THE AREA...NEAR CONSENSUS OF SHORT TERM MODELS. MAIN ISSUE WILL BE SEVERE WEATHER CHANCES SATURDAY AFTERNOON AND EVENING. LOW LEVEL WARM AIR ADVECTION RAMPS UP ON THE MODELS...BRINGING MID TO UPPER 60S FAHRENHEIT DEW POINTS BY SATURDAY AFTERNOON. SURFACE LOW PRESSURE AND COLD FRONT MOVES SOUTHEASTWARD TOWARD THE AREA DURING THE AFTERNOON...PER GFS/CANADIAN/ECMWF MODELS. THE NAM IS FURTHER NORTH WITH THE LOW TRACK...WHICH MAY BE AN OUTLIER SOLUTION. THIS TREND TO THE SOUTHWEST IS REFLECTED IN THE HRRR MODEL OUTPUT...WHICH KEEPS BULK OF CONVECTION JUST SOUTHWEST OF THE AREA. WRF/ARW AND NMM SOLUTIONS KEEP THE SOUTHWEST HALF OF THE AREA WITHIN THE LINE OF CONVECTION LATE IN THE AFTERNOON. THIS TRENDS TOWARD THE LATEST SPC DAY 2 OUTLOOK...WHICH HAS THE SOUTHWEST HALF OF THE AREA IN A SLIGHT RISK. FORECAST SOUNDINGS DO SHOW STRONG DEEP LAYER BULK SHEAR...WITH MEAN LAYER CAPES DEPENDENT ON HOW MUCH MIDDLE TO HIGH CLOUDS LIMIT DAYTIME HEATING. BULK OF CAPE ABOVE 700 MB LEVEL IN THE AFTERNOON...WITH MODEST UPWARD VERTICAL MOTION AHEAD OF THE LOW AND FRONT. THUS...SOME UNCERTAINTY HERE FOR SEVERE CONVECTION. KEPT LIKELY POPS FOR THUNDER ACROSS THE NORTHWEST HALF OF THE AREA BY LATE AFTERNOON...WITH LOWER POPS TO THE SOUTHEAST. KEPT UPPER 70S NORTH AND LOWER 80S SOUTH...WITH COOLER TEMPERATURES NEAR THE LAKE WITH A LAKE BREEZE LATE IN THE DAY. .SATURDAY NIGHT THROUGH MONDAY...FORECAST CONFIDENCE...MEDIUM THUNDERSTORMS WITH ABOVE MENTIONED SEVERE RISK WILL LIKELY BE ONGOING BY SATURDAY EVENING...EXITING THE SOUTHEAST BY LATE EVENING AS THE COLD FRONT PUSHES THROUGH SOUTHERN WISCONSIN. TAPERED POPS TO DRY BY LATER IN THE NIGHT AS HIGH PRESSURE MOVES IN BEHIND THE FRONT. SHOULD BE DRY SUNDAY UNDER THE HIGH. THERE WILL BE SOME MOISTURE RETURN FROM THE SOUTHWEST BY SUNDAY NIGHT AS THE HIGH SCOOTS EASTWARD...WITH SHOWER/STORM CHANCES RETURNING AFTER MIDNIGHT AND PERSISTING INTO MONDAY AS A SHORTWAVE MOVES THROUGH. SHOULD SEE HIGH TEMPS NEAR TO A COUPLE DEGREES ABOVE NORMAL SUNDAY AND MONDAY. THERE IS LESS CERTAINTY WITH TEMPS MONDAY THOUGH GIVEN THE CONVECTIVE POTENTIAL. .TUESDAY THROUGH FRIDAY...FORECAST CONFIDENCE...MEDIUM LOOKS MAINLY DRY TUESDAY AS HIGH PRESSURE BRIEFLY MOVES THROUGH...THOUGH KEPT SOME LOWER POPS FOR NOW UNTIL MODELS SETTLE ON THIS SOLUTION. HAVE SHOWER/STORM CHANCES GOING FOR TUESDAY THROUGH FRIDAY...AS MODELS CONTINUE TO SHOW A SERIES OF WAVES MOVING THROUGH MAINLY ZONAL FLOW. BIGGEST ISSUES DURING THIS PERIOD ARE TIMING OF INDIVIDUAL WAVES AND WHERE A FRONTAL BOUNDARY SETS UP...RESULTING IN MODEL DIFFERENCES IN TEMPS AND INSTABILITY. STUCK PRETTY CLOSE TO A CONSENSUS OF MODELS GIVEN THE UNCERTAINTY. && .AVIATION/00Z TAFS/....AVIATION/00Z TAFS/... VFR CONDITIONS ARE EXPECTED TONIGHT AND SATURDAY ACROSS TAF SITES. HIGH PRESSURE WILL SLIDE EAST OF THE REGION TONIGHT. MAINLY LIGHT EAST/NORTHEAST WINDS WILL GRADUALLY SHIFT SOUTHEAST LATER TONIGHT. MAY SEE LIGHT FOG WITH MVFR VISIBILITIES AT THE EASTERN SITES BETWEEN 09Z AND 13Z SATURDAY. LEFT OUT OF TAFS FOR NOW DUE TO UNCERTAINTY IN AREAL COVERAGE. WINDS WILL SHIFT TO THE SOUTH/SOUTHWEST ON SATURDAY...INCREASING IN SPEED DURING THE AFTERNOON. WINDS MAY REMAIN SOUTHEAST NEAR MILWAUKEE AND KENOSHA IN THE AFTERNOON WITH LAKE BREEZE. SHOWERS AND THUNDERSTORMS MAY AFFECT MADISON LATE IN THE DAY. MOST OF THE ACTIVITY SHOULD OCCUR SATURDAY EVENING...AS LOW PRESSURE AND A COLD FRONT MOVES SOUTHEAST THROUGH THE AREA. POTENTIAL FOR SEVERE STORMS IS MORE UNCERTAIN AT TAF SITES. BEST CHANCES WOULD BE AT MADISON IN THE LATE AFTERNOON AND EARLY EVENING. MVFR CEILINGS AND IFR VISIBILITIES ARE POSSIBLE IN ANY STORMS. && .MARINE... DEW POINTS IN THE 55 TO 60 DEGREE FAHRENHEIT RANGE MOVING OVER THE COOL LAKE MICHIGAN WATERS SHOULD BRING AT LEAST PATCHY FOG SATURDAY AFTERNOON...PERHAPS INTO SATURDAY NIGHT. WINDS WILL BE RELATIVELY LIGHT DURING THIS TIME...SHIFTING NORTHWEST TOWARD SUNDAY MORNING. DENSE FOG IS NOT EXPECTED AT THIS TIME. && .BEACHES... MODERATE SWIM RISK REMAINS INTO EARLY THIS EVENING ACROSS BEACHES IN MILWAUKEE COUNTY AND SOUTHWARD. NORTHEAST WINDS WILL WEAKEN BY EARLY EVENING. UNTIL THEN...BREAKING WAVES AND CURRENTS ARE EXPECTED. SWIMMERS ARE ADVISED TO STAY AWAY FROM DANGEROUS AREAS LIKE PIERS...BREAKWALLS AND RIVER OUTLETS. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ TONIGHT/SATURDAY AND AVIATION/MARINE/BEACHES...WOOD SATURDAY NIGHT THROUGH FRIDAY...DDV
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1247 AM MDT FRI JUN 19 2015 .UPDATE... ISSUED AT 637 PM MDT THU JUN 18 2015 UPDATED THIS EVENINGS FORECAST AND 00Z AVIATION FORECAST PACKAGE. HAD ONE STRONG TSTORM WHICH DEVELOPED WEST OF WHEATLAND AND DISSIPATED JUST WEST OF CHUGWATER. DO NOT ANTICIPATE ANY OTHER ACTIVITY THIS EVENING...BUT KEPT POP NEAR 20 PERCENT EAST OF THE SOUTHERN LARAMIE RANGE AND INTO WESTERN NEBRASKA SINCE THERE MAY BE SOME OUTFLOW ASSOCIATED WITH THAT STORM. OTHERWISE...SHOULD BE A MOSTLY CLEAR AND QUIET NIGHT. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 220 PM MDT THU JUN 18 2015 A RELENTLESS PERIOD OF SEVERE WEATHER FINALLY APPEARS TO BE COMING TO AN END THIS AFTERNOON. LOW-LEVEL WARM ADVECTION IS CONTRIBUTING TO STRONG CAPPING ACROSS MUCH OF THE PLAINS...AND ANY LARGER SCALE FORCING MECHANISMS ARE LIMITED. RESIDUAL OUTFLOW BOUNDARIES FROM YESTERDAYS CONVECTION...DIFFERENTIAL HEATING ACROSS LARAMIE COUNTY FROM MORNING STRATUS...AND WEAK LLVL UPSLOPE WILL BE THE FOCI FOR CONVECTIVE DEVELOPMENT THIS AFTERNOON. HRRR SHOWS ONE OR TWO STORMS ALONG THE LARAMIE RANGE AFTER 20Z...BUT THE LAST SEVERAL RUNS HAVE SHOWN VIRTUALLY NO DEVELOPMENT OR EASTWARD PROGRESS. WILL MAINTAIN MENTION OF ISOLATED THUNDER OVER THE PLAINS...BUT CONFIDENCE IS LOW THAT ANYWHERE EAST OF I25 WILL SEE MUCH. IF STORMS DEVELOP...THE BOUNDARY LAYER AIR MASS IS VERY MOIST WITH DEWPOINTS IN THE 55-65 F RANGE. MUCAPES OF 2500-3500 J/KG COMBINED WITH AVERAGE 0-6 KM SHEAR VALUES AROUND 30 KTS WILL SUPPORT SUPERCELLS...SO DO NOT SEE A GOOD REASON TO REMOVE SEVERE WORDING. SIMILAR TO LAST NIGHT...NOCTURNAL SOUTHERLY LLVL/H85 JET WILL CRANK UP OVER WESTERN NEB. CANNOT RULE OUT AN ELEVATED STORM LATE...BUT THINK THIS FEATURE WILL BE FEEDING AN MCS WELL TO THE NORTH OVER WESTERN SD. IT WILL BE BREEZY TONIGHT ALONG THE PINE RIDGE IN DAWES/SIOUX COUNTIES. A TOASTY AFTERNOON FOR FRIDAY WITH THE GFS/NAM/ECM/GEM ALL SHOWING H7 TEMPS AROUND 17-18 DEG C AND 1000-500 MB THICKNESS VALUES AROUND 585 DM OVER THE PLAINS. DESPITE LLVL CONVERGENCE ALONG A STRONG SFC TROUGH/DRYLINE ALONG THE WYO/NEB BORDER...WARM AIR ALOFT AND LARGER SCALE RIDGING WILL SUPPRESS ANY CONVECTION. SUBSIDENCE SHOULD SUPPORT MOSTLY SUNNY SKIES AS WELL. DEPENDING ON HOW MUCH AFTERNOON CUMULUS WE SEE...NEAR RECORD HIGHS ARE POSSIBLE WITH UPPER 90S TO NEAR 100 F OVER THE SOUTHERN PANHANDLE. IN ADDITION...THIS IS A GREAT PATTERN FOR NIGHTLY MCS COMPLEXES OVER NORTHEAST WY AND WESTERN SD...SO WE CANNOT RULE OUT NIGHT TIME OR EARLY AM CONVECTION ACROSS OUR FAR NORTHERN ZONES...MOVING IN FROM NEIGHBORING CWAS. OTHERWISE WE CAN ENJOY A PLEASANT...ALBEIT WARM AFTERNOON/EVENING FREE OF ANY SHOWER OR THUNDERSTORM ACTIVITY. COOLER ON SAT WITH A COLD FROPA...ALONG WITH A CHANCE FOR ISOLATED AFTERNOON CONVECTION. THE DAY 3 OUTLOOK FROM SPC HAS A GOOD CHUNK OF THE AREA IN A MRGNL RISK...WHICH SEEMS APPROPRIATE WITH THE NAM SHOWING STRONG INSTABILITY AND GOOD SHEAR BENEATH 50 KT FLOW AT H5. COULD SEE THE RISK CATEGORY BEING BUMPED UP IN THE FUTURE DEPENDING ON THE DEGREE OF FORCING/CAPPING. KEPT POPS ISOLATED FOR NOW...BUT EXPECT A REVISION UPWARDS. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 220 PM MDT THU JUN 18 2015 THE MAIN CONCERN WITH THIS PORTION OF THE FORECAST PACKAGE IS HOW MUCH CAP WILL BE IN PLACE THROUGH THE WEEK. LATEST WATER VAPOR LOOP WAS SHOWING DRIER AIR STARTING TO PUSH EAST ACROSS THE SOUTHWEST. THIS IS IN RESPONSE TO WEAK UPPER LEVEL RIDGING THAT WILL CONTINUE TO PUSH EAST INTO THE SOUTHERN HIGH PLAINS THIS WEEKEND. THIS IN COMBINATION WITH WEAK TROFS MOVING THROUGH THE PACIFIC NORTHWEST WILL RESULT IN A MORE ZONAL PATTERN OVER OUR REGION THROUGH THE WEEK. SATURDAY NIGHT: THIS TIMEFRAME APPEARS TO BE THE MAIN CONCERN AS A STRONG (90-100KT) JET AND MID LEVEL SHORTWAVE MOVES THROUGH WYOMING. THIS JET WILL PROVIDE STRONG WINDS ALOFT. IN ADDITION...THE LOW LEVEL FLOW IS EXPECTED TO TURN TO EAST- SOUTHEAST AHEAD OF SHORTWAVE WHICH WILL RESULT IN ADVECTION OF DEEPER MOISTURE WITH 0-6KM SHEAR VALUES AROUND 40 TO 50KTS. ONGOING THUNDERSTORMS IN THE AFTERNOON SHOULD GENERALLY TRACK WEST TO EAST AT AROUND 15 TO 20KTS WITH RIGHT MOVING SUPERCELLS TRACKING SOUTHEAST AT 15KTS. WE ARE A BIT WORRIED THAT THIS CONVECTION MAY TRY TO SLOW DOWN LATE SATURDAY EVENING AS THE LOW LEVEL JET INCREASES TO AROUND 30 TO 35 KTS WHICH MAY YIELD TO BACKBUILDING STORMS AND POSSIBLE HEAVY RAINFALL. SUNDAY-TUESDAY NIGHT: THE MODELS ARE IN PRETTY GOOD AGREEMENT IS BUILDING THE UPPER LEVEL RIDGE SLIGHTLY OVER OUR REGION. THIS SHOULD SUPPORT SOME GOOD CAPPING OVER THE AREA WHICH WILL RESULT IN WARMER TEMPERATURES AND LIMITED CONVECTION. THIS SHOULD ALSO ALLOW FOR SOILS TO DRY OUT. CANNOT RULE SOME ISOLATED CONVECTION ON TUESDAY AS THE CAP BEGINS TO WEAKEN IN RESPONSE TO WEAK POTENTIAL VORTICITY ANOMALY MOVING THROUGH THE AREA. WEDNESDAY-THURSDAY: THE GFS SHOWS A POTENTIAL VORTICITY ANOMALY PUSHING THROUGH NORTHERN MONTANA AND SOUTHERN CANADA ON WEDNESDAY INTO THURSDAY. THE ECMWF IS MUCH WEAKER WITH THIS WAVE BUT SHOWS MORE RIDGING BUILDING OVER INTERMOUNTAIN WEST...AND PROVIDES MORE TROFFING OVER THE NORTHERN PLAINS. EITHER WAY...THIS MAY RESULT IN ANOTHER CHANCE OF AFTERNOON THUNDERSTORMS DUE TO A WEAKER CAP ESPECIALLY ALONG AND EAST OF THE LARAMIE RANGE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1247 AM MDT FRI JUN 19 2015 IFR-MVFR STRATUS WILL CONTINUE TO DEVELOP ACROSS THE PANHANDLE TONIGHT AND WILL PERSIST THROUGH MID-MORNING. SOUTHERLY WINDS WILL REMAIN GUSTY OVER THE PLAINS OVERNIGHT AND THROUGH MUCH OF LATE FRIDAY MORNING...WITH GUSTY WESTERLY WINDS DEVELOPING OUT WEST IN THE MORNING AS WELL. THUNDERSTORM CHANCES CONTINUE TO LOOK MINIMAL FRIDAY AFTERNOON WITH A STRONG MIDLEVEL CAP IN PLACE. && .FIRE WEATHER... ISSUED AT 220 PM MDT THU JUN 18 2015 VERY WARM AND DRY CONDITIONS ARE EXPECTED FOR FRIDAY. ELEVATED FIRE WEATHER CONDITIONS ARE EXPECTED. AFTERNOON RH VALUES WILL FALL TO BETWEEN 10 AND 20 PERCENT...WITH WESTERLY WINDS GUSTING TO 25 MPH ALONG AND WEST OF THE LARAMIE RANGE. ISOLATED SHOWERS/THUNDERSTORMS ARE POSSIBLE TODAY AND SATURDAY...POSSIBLY SEVERE. WINDS COULD BE GUSTY AND ERRATIC NEAR CONVECTION. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ UPDATE...TJT/JG SHORT TERM...REC LONG TERM...CLH AVIATION...RJM FIRE WEATHER...CLH
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1106 PM MDT SAT JUN 20 2015 .UPDATE... ISSUED AT 842 PM MDT SAT JUN 20 2015 UPDATED TO END SHOWERS AND THUNDERSTORMS ACROSS THE AREA FOR THE REMAINDER OF THE NIGHT. RADAR AND SATELLITE INDICATE A COUPLE OF SHOWERS STILL OVER THE SAN JUAN RANGE...BUT HAVE QUICKLY BEEN DISSIPATING AND SHOULD COME TO AN END BY 10 PM. NO OTHER UPDATES AT THIS TIME. MOZLEY && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 256 PM MDT SAT JUN 20 2015 WEAK COLD FRONT WHICH PUSHED THROUGH THE PLAINS EARLIER TODAY HAS BROUGHT E-NE WINDS AND SLIGHTLY COOLER TEMPS TO THE PLAINS/ERN MOUNTAINS...WHILE TEMPS FARTHER WEST OVER THE MOUNTAINS AND INTERIOR VALLEYS REMAIN LITTLE CHANGED. LOW LEVEL MOISTURE/INSTABILITY LOOK SUFFICIENT FOR SOME ISOLATED TSRA OVER THE ERN MOUNTAINS...THOUGH LACK OF ANY TRIGGER AND FAIRLY SUBSTANTIAL CIN HAS SO FAR KEPT THINGS IN CHECK. LAST COUPLE RUNS OF THE NAM STILL HAVE SOME WEAK TSRA DEVELOPING...WHILE HRRR AND OTHER MESOSCALE MODELS ARE MAINLY DRY. WILL KEEP JUST SOME VERY LOW POPS FOR A FEW OF THE HIGHER PEAKS INTO EARLY EVENING...THOUGH WOULD NOT BE TOO SURPRISED TO SEE AREA REMAIN CONVECTION FREE AT THIS POINT. ANY CLOUDS WILL CLEAR QUICKLY AFTER SUNSET...WITH OVERNIGHT LOWS JUST SLIGHTLY COOLER THAN SAT MORNING MOST LOCATIONS. ON SUNDAY...HEIGHTS BUILD SLIGHTLY AND WITH PRESSURE FALLS OVER THE PLAINS PRODUCING A RETURN TO S-SW WINDS...EXPECT ALL AREAS TO BECOME VERY HOT ONCE AGAIN...WITH READINGS NEAR/OVER 100F ACROSS THE LOWER ARK VALLEY. AIR MASS LOOKS TOO DRY TO SUPPORT ANY CONVECTION...SO WILL KEEP A DRY FORECAST GOING ALL AREAS THROUGH THE AFTERNOON. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 256 PM MDT SAT JUN 20 2015 SUNDAY NIGHT AND MONDAY...STRONG UPPER RIDGE WILL BRING MAINLY DRY AND HOT WEATHER ACROSS THE CWA. THERE WILL ONLY BE A VERY SLIGHT CHANCE FOR LATE AFTERNOON AND EVENING HIGH BASED CONVECTION OVER THE EASTERN PART OF THE AREA. HIGH TEMPERATURES WILL RANGE FROM 90 TO 100 ACROSS THE I-25 CORRIDOR AND SOUTHEAST PLAINS...70S AND 80S HIGH VALLEYS...AND 60S AND 70S MOUNTAINS. TUESDAY AND WEDNESDAY...UPPER RIDGE PUSHES EAST SOME...ALLOWING A FETCH OF MODEST MOISTURE TO ENTER THE AREA. IN ADDITION...A SURFACE BOUNDARY WILL BE IN THE VICINITY OF THE EASTERN PLAINS...SO ISOLATED TO SCATTERED PRECIPITATION WILL BE EVIDENT DURING THE AFTERNOON AND EVENING HOURS. MODELS DIVERGENT ON HOW MUCH CONVECTION WILL BE ACROSS THE EAST TUESDAY EVENING. GFS HAS THE MOST...WITH EUROPEAN BARELY ANY. THERE IS THE POTENTIAL FOR A FEW SEVERE STORMS BOTH DAYS WITH INSTABILITY VALUES INCREASING. WITH SOME CLOUD COVER...TEMPERATURES WILL BE A LITTLE LOWER THAN OVER THE WEEKEND. THURSDAY THROUGH SUNDAY...UPPER RIDGE FORECAST TO BUILD TO OUR WEST DURING THE PERIOD. GFS SHOWS A SHORTWAVE RIDING DOWN THE NORTHEAST SIDE OF THE RIDGE IN THE THURSDAY TO FRIDAY TIME FRAME...MORE SO THAN THE EUROPEAN. THERE WILL LIKELY BE DIURNAL SHOWERS AND STORMS EACH DAY WITH NORTHWEST FLOW ALOFT ON THE FRONT SIDE OF THE RIDGE....MORE CONCENTRATED ACROSS THE EASTERN HALF OF THE CWA. HIGH TEMPERATURES WILL BE NEAR SEASONAL AVERAGES...IN THE 80S AND 90S PLAINS...70S AND 80S HIGH VALLEYS AND 50S TO 70S MOUNTAINS. -TLM- && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1105 PM MDT SAT JUN 20 2015 VFR CONDITIONS AT ALL THREE TERMINALS THROUGH THE NEXT 24 HOURS. A FEW AFTERNOON WIND GUSTS TO NEAR 25 KTS ARE POSSIBLE AT KCOS ON SUNDAY AFTERNOON. MOZLEY && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...MOZLEY SHORT TERM...PETERSEN LONG TERM...TM AVIATION...MOZLEY
AREA FORECAST DISCUSSION
NWS ALBANY NY
213 AM EDT SUN JUN 21 2015 .SYNOPSIS... THE REMNANTS OF TROPICAL STORM BILL WILL IMPACT THE REGION TONIGHT INTO SUNDAY BRINGING A MODERATE TO HEAVY RAINFALL TO AREAS TO THE SOUTH AND EAST OF THE CAPITAL DISTRICT. A LOW PRESSURE SYSTEM WILL APPROACH THE REGION TONIGHT AND MOVE ACROSS THE AREA SUNDAY AND SUNDAY NIGHT TRIGGERING SHOWERS AND THUNDERSTORMS MAINLY DURING THE AFTERNOON INTO THE EVENING HOURS. SOME THUNDERSTORMS MAYBE STRONG TO POSSIBLY SEVERE TO THE NORTH AND WEST OF THE CAPITAL DISTRICT. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1230 AM EDT...RADAR CONTINUES TO SHOW WIDESPREAD LIGHT TO MODERATE RAIN FOR MOST AREAS NEAR AND SOUTH OF INTERSTATE 90...ALONG WITH EMBEDDED POCKETS OF HEAVIER RAIN. IN FACT...SOME CG LIGHTNING STRIKES HAVE BEEN NOTED ACROSS PORTIONS OF NORTHERN ULSTER CO. THE REMNANTS OF TC BILL PASSING TO THE SOUTH WILL COMBINE WITH THE RETURN FLOW AROUND A DEPARTING HIGH TO HELP PWATS RISE. THEY ARE EXPECTED TO INCREASE TO 1 1/2+ INCHES ACROSS THE FORECAST AREA WITH AROUND 2 INCHES ACROSS THE SOUTHERN MOST PORTION AS THE REMNANTS OF BILL MOVE ACROSS THE MID ATLANTIC REGION TOWARD THE NEW YORK METROPOLITAN AREA FOR LATER TONIGHT. THE NEW 00Z NAM...AS WELL AS THE 3KM HRRR GUIDANCE...ALL SUGGEST STEADY AND HEAVIER RAINFALL WILL CONTINUE TO OVERSPREAD OUR REGION OVER THE NEXT SEVERAL HOURS...AS THE LOW PASSES SOUTH OF THE AREA...AND SOME OF THE HEAVIER PRECIP OVER PA STARTS TO ROTATE TOWARDS SOUTHERN PORTIONS OF THE REGION. THIS WILL ESPECIALLY BE TRUE FOR AREAS FROM THE CAPITAL REGION ON SOUTHWARD. RAINFALL LOOKS TO BE FAIRLY STEADY THROUGH DAYBREAK...AND MAY BE LOCALLY HEAVY...ESPECIALLY FOR FAR SOUTHERN AREAS. CANNOT RULE OUT ADDITIONAL RUMBLES OF THUNDER IN A FEW SPOTS DUE TO SOME SMALL AMOUNTS OF ELEVATED INSTABILITY IN PLACE AS WELL. NO FLOOD WATCH HAS BEEN ISSUED SINCE RAIN RATES WON/T APPEAR TO EXCEED FLASH FLOOD GUIDANCE. STILL...SOME PONDING OF WATER ON ROADWAYS AND IN URBAN AND LOW LYING AREAS MAY STILL OCCUR IN A FEW LOCATIONS...AND THIS WILL CONTINUE TO BE HIGHLIGHTED IN THE HWO STATEMENT. THIS RAINFALL WILL BE HELPING ACROSS THESE SOUTHERN AND EASTER AREAS...AS THE ANNUAL DEPARTURE FROM NORMAL FOR POUGHKEEPSIE NY STANDS AT -7.62 INCHES AND IS PITTSFIELD MA -4.18 INCHES. OVERNIGHT LOWS WILL MAINLY BE IN THE 60S...ALONG WITH THE MUGGY AND CLOUDY CONDITIONS. && .SHORT TERM /6 AM THIS MORNING THROUGH MONDAY NIGHT/... THE REMNANTS OF BILL ARE EXPECTED TO TRACK TO ACROSS THE NEW YORK METRO AREA AND LONG ISLAND AND WILL CONTINUE TO IMPACTS MAINLY THE AREAS TO THE SOUTH AND EAST OF THE CAPITAL DISTRICT THROUGH THE MORNING INTO THE EARLY AFTERNOON HOURS. A SHORT WAVE TROUGH AND LOW PRESSURE SYSTEM MOVING THROUGH THE FAST ZONAL FLOW WILL BE ON THE APPROACH FOR SUNDAY. THE SYSTEM`S WARM FRONT IS EXPECTED TO LIFT ACROSS THE REGION SUNDAY PLACING US IN THE WARM SECTOR. THE AMOUNT OF INSTABILITY IS THE BIG QUESTION. FLOW WILL BE UNIDIRECTIONAL WITH SHEAR INCREASING AS THE AFTERNOON PROGRESSES INTO THE EVENING HOURS. IF THERE IS ENOUGH INSTABILITY TO WORK MULTICELLS CLUSTERS SHOULD FORM. HOWEVER GUIDANCE IS NOT IN AGREEMENT ABOUT HOW STEEP THE LAPSE RATES SHOULD GET. THE STORM PREDICTION CENTER HAS UPGRADED THE SEVERE WEATHER RISK TO SLIGHT FOR MUCH OF EAST CENTRAL NEW YORK...FOR AREAS TO THE NORTH AND WEST OF THE CAPITAL DISTRICT...WITH THE REST OF THE FORECAST AREA UNDER A MARGINAL RISK. HAVE ENHANCED WORDING IN THE FORECAST FOR GUSTY WINDS...SMALL HAIL AND HEAVY RAINFALL ADDRESSING THE THREAT. CHANCES FOR STORMS WILL DECREASE OVERNIGHT SUNDAY INTO MONDAY AS THE SHORT WAVE MOVES OFF TO OUR EAST. SOME RIDGING WILL BRIEFLY BUILD IN BETWEEN SHORT WAVES RESULTING IN MAINLY FAIR WEATHER WITH SEASONABLE TEMPERATURES MONDAY. && .LONG TERM /TUESDAY THROUGH SATURDAY/... THIS WILL BE A PREDOMINANTLY WET PERIOD WITH MAINLY SEASONABLE TEMPERATURES. THE ONLY DRY PERIOD IS EXPECTED TO RUN FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. THERE WILL BE PERIODS OF SUNSHINE... BUT ASIDE FROM TUESDAY...INSTABILITY AND MOISTURE WILL BE LIMITED...SO THE MENTION IS FOR JUST SHOWERS. HIGH TEMPERATURES WILL START OFF TUESDAY FROM AROUND 70 DEGREES IN THE WESTERN ADIRONDACKS...TO THE UPPER 80S IN THE LOWER MID HUDSON VALLEY...BUT WILL GRADUALLY COOL DOWN...TO HIGHS RANGING FROM THE MID 60S TO MID 70S BY FRIDAY. SATURDAY WILL AVERAGE ONLY SLIGHTLY WARMER. TUESDAY NIGHT WILL BE MILDEST...WITH LOWS FROM THE MID 50S TO LOWER 60S. BY FRIDAY NIGHT...LOWS WILL RANGE FROM AROUND 50 DEGREES IN THE NORTHERN HIGH PEAKS...TO THE UPPER 50S IN THE MID HUDSON VALLEY. NORMAL HIGHS AND LOWS FOR ALBANY DURING THIS PERIOD ARE LOWER 80S AND AROUND 59 DEGREES...RESPECTIVELY. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... FLYING CONDITIONS WILL BE MVFR/IFR THROUGH 09Z AS PLENTY OF LOW- LEVEL MOISTURE AND RAIN SHOWERS MOVE ACROSS THE REGION. FLYING CONDITIONS ARE EXPECTED TO BE PREDOMINATELY MVFR VISIBILITIES...WITH PREDOMINATELY IFR CEILINGS DUE TO LOW STRATUS. HAVE PLACED TEMPO GROUPS AT THE TAF SITES FROM 06Z TO 09Z FOR BRIEF IFR VISIBILITY REDUCTIONS ASSOCIATED WITH HEAVY RAIN SHOWERS. LATEST RADAR TRENDS INDICATE RAIN WILL CONTINUE TO BECOME MORE OF A SHOWERY NATURE...BEFORE TAPERING OFF BETWEEN BY AROUND 10Z TO 14Z. WINDS OVERNIGHT WILL BE SOUTHEAST...BUT LIGHT AROUND 4-8 KNOTS. FLYING CONDITIONS SHOULD IMPROVE ABOVE IFR AFTER 12Z AS SHOWERS END...BUT IT MAY TAKE UNTIL THE MID TO LATE MORNING FOR FLYING CONDITIONS TO RETURN TO ABOVE MVFR LEVELS. DURING THE MID TO LATE AFTN HOURS...THERE MAY BE SOME ADDITIONAL SHOWERS OR T-STORMS AROUND...BUT THESE WILL BE RATHER SCATTERED IN NATURE. SOUTHERLY WINDS WILL EVENTUALLY BECOME WESTERLY AROUND 10 KTS. OUTLOOK... SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. LIKELY SHRA...TSRA. MONDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. MONDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. TUESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. WEDNESDAY: NO OPERATIONAL IMPACT. NO SIG WX. WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. THURSDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. && .FIRE WEATHER... THE REMNANTS OF TROPICAL STORM BILL WILL IMPACT THE REGION TONIGHT INTO SUNDAY BRINGING A MODERATE TO HEAVY RAINFALL TO AREAS TO THE SOUTH AND EAST OF THE CAPITAL DISTRICT. A LOW PRESSURE SYSTEM WILL APPROACH THE REGION TONIGHT AND MOVE ACROSS THE AREA SUNDAY AND SUNDAY NIGHT TRIGGERING SHOWERS AND THUNDERSTORMS MAINLY DURING THE AFTERNOON INTO THE EVENING HOURS. CONDITIONS DRY OUT FOR MONDAY...HOWEVER MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED TUESDAY. && .HYDROLOGY... PWATS WILL BE IN THE RISE AND ARE EXPECTED TO INCREASE TO 1 1/2+ INCHES ACROSS THE FORECAST AREA WITH AROUND 2 INCHES ACROSS THE SOUTHERN MOST PORTION AS THE REMNANTS OF BILL MOVE ACROSS THE MID ATLANTIC REGION TOWARD THE NEW YORK METROPOLITAN AREA. THE GUIDANCE HAS TRENDED A BIT NORTHWARD WITH THE HEAVIER QPF. THE GFS IS THE MOST AGGRESSIVE HOWEVER IT APPEARS TO BE HAVING CONVECTIVE FEEDBACK ISSUES AND CAN BE TRUSTED. A MODERATE TO HEAVY RAINFALL IS EXPECTED TO THE SOUTH AND EAST OF THE CAPITAL DISTRICT AS THE HIGHER PWATS ARRIVE. NO FLOOD WATCH HAS BEEN ISSUED. THE SOUTHEASTERN PORTION OF THE FORECAST UNDER THE SEVERE DROUGHT CATEGORY ON THE U.S. DROUGHT MONITOR. THE ANNUAL DEPARTURE FROM NORMAL FOR POUGHKEEPSIE NY STANDS AT -7.62 INCHES AND IS PITTSFIELD MA -4.18 INCHES. SOME URBAN AND POOR DRAINING FLOODING IS POSSIBLE. PWATS WILL DECREASE SOME SUNDAY AS THE REMNANTS OF BILL MOVE AWAY FROM THE REGION. HOWEVER A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE AREA SUNDAY TRIGGERING SHOWERS AND THUNDERSTORMS. THE FOCUS FOR THIS ACTIVITY WILL BE MAINLY TO THE NORTH AND WEST OF THE CAPITAL DISTRICT SUNDAY AFTERNOON INTO THE EVENING. LOCALLY HEAVY RAINFALL WILL BE POSSIBLE WITH SOME THUNDERSTORMS. CONDITIONS DRY OUT FOR MONDAY...HOWEVER MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED TUESDAY. 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...IAA NEAR TERM...IAA/FRUGIS/KL SHORT TERM...IAA LONG TERM...ELH AVIATION...IRL FIRE WEATHER...IAA HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS ALBANY NY
1233 AM EDT SUN JUN 21 2015 .SYNOPSIS... THE REMNANTS OF TROPICAL STORM BILL WILL IMPACT THE REGION TONIGHT INTO SUNDAY BRINGING A MODERATE TO HEAVY RAINFALL TO AREAS TO THE SOUTH AND EAST OF THE CAPITAL DISTRICT. A LOW PRESSURE SYSTEM WILL APPROACH THE REGION TONIGHT AND MOVE ACROSS THE AREA SUNDAY AND SUNDAY NIGHT TRIGGERING SHOWERS AND THUNDERSTORMS MAINLY DURING THE AFTERNOON INTO THE EVENING HOURS. SOME THUNDERSTORMS MAYBE STRONG TO POSSIBLY SEVERE TO THE NORTH AND WEST OF THE CAPITAL DISTRICT. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1230 AM EDT...RADAR CONTINUES TO SHOW WIDESPREAD LIGHT TO MODERATE RAIN FOR MOST AREAS NEAR AND SOUTH OF INTERSTATE 90...ALONG WITH EMBEDDED POCKETS OF HEAVIER RAIN. IN FACT...SOME CG LIGHTNING STRIKES HAVE BEEN NOTED ACROSS PORTIONS OF NORTHERN ULSTER CO. THE REMNANTS OF TC BILL PASSING TO THE SOUTH WILL COMBINE WITH THE RETURN FLOW AROUND A DEPARTING HIGH TO HELP PWATS RISE. THEY ARE EXPECTED TO INCREASE TO 1 1/2+ INCHES ACROSS THE FORECAST AREA WITH AROUND 2 INCHES ACROSS THE SOUTHERN MOST PORTION AS THE REMNANTS OF BILL MOVE ACROSS THE MID ATLANTIC REGION TOWARD THE NEW YORK METROPOLITAN AREA FOR LATER TONIGHT. THE NEW 00Z NAM...AS WELL AS THE 3KM HRRR GUIDANCE...ALL SUGGEST STEADY AND HEAVIER RAINFALL WILL CONTINUE TO OVERSPREAD OUR REGION OVER THE NEXT SEVERAL HOURS...AS THE LOW PASSES SOUTH OF THE AREA...AND SOME OF THE HEAVIER PRECIP OVER PA STARTS TO ROTATE TOWARDS SOUTHERN PORTIONS OF THE REGION. THIS WILL ESPECIALLY BE TRUE FOR AREAS FROM THE CAPITAL REGION ON SOUTHWARD. RAINFALL LOOKS TO BE FAIRLY STEADY THROUGH DAYBREAK...AND MAY BE LOCALLY HEAVY...ESPECIALLY FOR FAR SOUTHERN AREAS. CANNOT RULE OUT ADDITIONAL RUMBLES OF THUNDER IN A FEW SPOTS DUE TO SOME SMALL AMOUNTS OF ELEVATED INSTABILITY IN PLACE AS WELL. NO FLOOD WATCH HAS BEEN ISSUED SINCE RAIN RATES WON/T APPEAR TO EXCEED FLASH FLOOD GUIDANCE. STILL...SOME PONDING OF WATER ON ROADWAYS AND IN URBAN AND LOW LYING AREAS MAY STILL OCCUR IN A FEW LOCATIONS...AND THIS WILL CONTINUE TO BE HIGHLIGHTED IN THE HWO STATEMENT. THIS RAINFALL WILL BE HELPING ACROSS THESE SOUTHERN AND EASTER AREAS...AS THE ANNUAL DEPARTURE FROM NORMAL FOR POUGHKEEPSIE NY STANDS AT -7.62 INCHES AND IS PITTSFIELD MA -4.18 INCHES. OVERNIGHT LOWS WILL MAINLY BE IN THE 60S...ALONG WITH THE MUGGY AND CLOUDY CONDITIONS. && .SHORT TERM /6 AM THIS MORNING THROUGH MONDAY NIGHT/... THE REMNANTS OF BILL ARE EXPECTED TO TRACK TO ACROSS THE NEW YORK METRO AREA AND LONG ISLAND AND WILL CONTINUE TO IMPACTS MAINLY THE AREAS TO THE SOUTH AND EAST OF THE CAPITAL DISTRICT THROUGH THE MORNING INTO THE EARLY AFTERNOON HOURS. A SHORT WAVE TROUGH AND LOW PRESSURE SYSTEM MOVING THROUGH THE FAST ZONAL FLOW WILL BE ON THE APPROACH FOR SUNDAY. THE SYSTEM`S WARM FRONT IS EXPECTED TO LIFT ACROSS THE REGION SUNDAY PLACING US IN THE WARM SECTOR. THE AMOUNT OF INSTABILITY IS THE BIG QUESTION. FLOW WILL BE UNIDIRECTIONAL WITH SHEAR INCREASING AS THE AFTERNOON PROGRESSES INTO THE EVENING HOURS. IF THERE IS ENOUGH INSTABILITY TO WORK MULTICELLS CLUSTERS SHOULD FORM. HOWEVER GUIDANCE IS NOT IN AGREEMENT ABOUT HOW STEEP THE LAPSE RATES SHOULD GET. THE STORM PREDICTION CENTER HAS UPGRADED THE SEVERE WEATHER RISK TO SLIGHT FOR MUCH OF EAST CENTRAL NEW YORK...FOR AREAS TO THE NORTH AND WEST OF THE CAPITAL DISTRICT...WITH THE REST OF THE FORECAST AREA UNDER A MARGINAL RISK. HAVE ENHANCED WORDING IN THE FORECAST FOR GUSTY WINDS...SMALL HAIL AND HEAVY RAINFALL ADDRESSING THE THREAT. CHANCES FOR STORMS WILL DECREASE OVERNIGHT SUNDAY INTO MONDAY AS THE SHORT WAVE MOVES OFF TO OUR EAST. SOME RIDGING WILL BRIEFLY BUILD IN BETWEEN SHORT WAVES RESULTING IN MAINLY FAIR WEATHER WITH SEASONABLE TEMPERATURES MONDAY. && .LONG TERM /TUESDAY THROUGH SATURDAY/... THIS WILL BE A PREDOMINANTLY WET PERIOD WITH MAINLY SEASONABLE TEMPERATURES. THE ONLY DRY PERIOD IS EXPECTED TO RUN FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. THERE WILL BE PERIODS OF SUNSHINE... BUT ASIDE FROM TUESDAY...INSTABILITY AND MOISTURE WILL BE LIMITED...SO THE MENTION IS FOR JUST SHOWERS. HIGH TEMPERATURES WILL START OFF TUESDAY FROM AROUND 70 DEGREES IN THE WESTERN ADIRONDACKS...TO THE UPPER 80S IN THE LOWER MID HUDSON VALLEY...BUT WILL GRADUALLY COOL DOWN...TO HIGHS RANGING FROM THE MID 60S TO MID 70S BY FRIDAY. SATURDAY WILL AVERAGE ONLY SLIGHTLY WARMER. TUESDAY NIGHT WILL BE MILDEST...WITH LOWS FROM THE MID 50S TO LOWER 60S. BY FRIDAY NIGHT...LOWS WILL RANGE FROM AROUND 50 DEGREES IN THE NORTHERN HIGH PEAKS...TO THE UPPER 50S IN THE MID HUDSON VALLEY. NORMAL HIGHS AND LOWS FOR ALBANY DURING THIS PERIOD ARE LOWER 80S AND AROUND 59 DEGREES...RESPECTIVELY. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... FLYING CONDITIONS HAVE LOWERED DOWN TO MVFR CONDITIONS FOR CIGS FOR ALL SITES DUE TO ABUNDANT LOW LEVEL MOISTURE CAUSING PLENTY OF LOW STRATUS TO FORM. OVER THE NEXT FEW HOURS...RAIN SHOWERS WILL SPREAD ACROSS THE REGION FROM THE WEST. THIS WILL DROP VSBYS DOWN TO MVFR LEVELS AS WELL...AND EVENTUALLY IFR CONDITIONS FOR BOTH VSBYS/CIGS BY AROUND MIDNIGHT OR SO. THIS WILL CONTINUE THROUGH THE REMAINDER OF THE OVERNIGHT HOURS...WITH LIGHT TO CALM WINDS. SHOWERS WILL TAPER OFF BY AROUND 6-9 AM OVER THE REGION. IFR CONDITIONS SHOULD END ONCE THE RAIN STOPS...BUT IT MAY TAKE UNTIL THE MID TO LATE MORNING FOR FLYING CONDITIONS TO RETURN TO ABOVE MVFR LEVELS. DURING THE MID TO LATE AFTN HOURS...THERE MAY BE SOME ADDITIONAL SHOWERS OR T-STORMS AROUND...BUT THESE WILL BE RATHER SCT IN NATURE. SOUTHERLY WINDS WILL EVENTUALLY BECOME WESTERLY AROUND 10 KTS OR SO. OUTLOOK... SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. LIKELY SHRA...TSRA. MONDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. MONDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. TUESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. WEDNESDAY: NO OPERATIONAL IMPACT. NO SIG WX. WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. THURSDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. && .FIRE WEATHER... THE REMNANTS OF TROPICAL STORM BILL WILL IMPACT THE REGION TONIGHT INTO SUNDAY BRINGING A MODERATE TO HEAVY RAINFALL TO AREAS TO THE SOUTH AND EAST OF THE CAPITAL DISTRICT. A LOW PRESSURE SYSTEM WILL APPROACH THE REGION TONIGHT AND MOVE ACROSS THE AREA SUNDAY AND SUNDAY NIGHT TRIGGERING SHOWERS AND THUNDERSTORMS MAINLY DURING THE AFTERNOON INTO THE EVENING HOURS. CONDITIONS DRY OUT FOR MONDAY...HOWEVER MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED TUESDAY. && .HYDROLOGY... PWATS WILL BE IN THE RISE AND ARE EXPECTED TO INCREASE TO 1 1/2+ INCHES ACROSS THE FORECAST AREA WITH AROUND 2 INCHES ACROSS THE SOUTHERN MOST PORTION AS THE REMNANTS OF BILL MOVE ACROSS THE MID ATLANTIC REGION TOWARD THE NEW YORK METROPOLITAN AREA. THE GUIDANCE HAS TRENDED A BIT NORTHWARD WITH THE HEAVIER QPF. THE GFS IS THE MOST AGGRESSIVE HOWEVER IT APPEARS TO BE HAVING CONVECTIVE FEEDBACK ISSUES AND CAN BE TRUSTED. A MODERATE TO HEAVY RAINFALL IS EXPECTED TO THE SOUTH AND EAST OF THE CAPITAL DISTRICT AS THE HIGHER PWATS ARRIVE. NO FLOOD WATCH HAS BEEN ISSUED. THE SOUTHEASTERN PORTION OF THE FORECAST UNDER THE SEVERE DROUGHT CATEGORY ON THE U.S. DROUGHT MONITOR. THE ANNUAL DEPARTURE FROM NORMAL FOR POUGHKEEPSIE NY STANDS AT -7.62 INCHES AND IS PITTSFIELD MA -4.18 INCHES. SOME URBAN AND POOR DRAINING FLOODING IS POSSIBLE. PWATS WILL DECREASE SOME SUNDAY AS THE REMNANTS OF BILL MOVE AWAY FROM THE REGION. HOWEVER A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE AREA SUNDAY TRIGGERING SHOWERS AND THUNDERSTORMS. THE FOCUS FOR THIS ACTIVITY WILL BE MAINLY TO THE NORTH AND WEST OF THE CAPITAL DISTRICT SUNDAY AFTERNOON INTO THE EVENING. LOCALLY HEAVY RAINFALL WILL BE POSSIBLE WITH SOME THUNDERSTORMS. CONDITIONS DRY OUT FOR MONDAY...HOWEVER MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED TUESDAY. 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...IAA NEAR TERM...IAA/FRUGIS/KL SHORT TERM...IAA LONG TERM...ELH AVIATION...FRUGIS FIRE WEATHER...IAA HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
325 AM CDT SUN JUN 21 2015 .SHORT TERM... 329 PM CDT THROUGH TONIGHT... STILL LINGERING UNCERTAINTY REGARDING THE POTENTIAL FOR STRONG TO SEVERE STORMS THIS EVENING...WITH AN OVERALL TREND TOWARD A LOWER THREAT FOR THE THE NORTHEAST 1/2 TO 2/3 OF THE CWA. AS NOTED EARLIER...CLOUD COVER HAS OVERALL LIMITED DESTABILIZATION PROCESS EVEN IN PRESENCE OF GRADUALLY MOISTENING DEWPOINTS. ALSO A VERY STOUT WARM NOSE AT BASE OF EML ADVECTING WESTWARD CENTERED FROM 750-850 MB NOTED ON 18Z DVN SOUNDING WILL RESULT IN CAPPING/CINH AS DESTABILIZATION OCCURS LATE THIS AFTERNOON. ITS APPEARS THAT LINGERING CLUSTER OF THUNDERSTORMS OVER NORTHEAST IA AND NORTHWEST IL ON NOSE OF SPEED MAX SEEN ON W/V IMAGERY COULD BE MAIN FOCUS FOR WHAT OCCURS THIS EVENING...ONCE STRONGER FORCING ARRIVES AND WEAKENS THE CAP. IT STILL LOOKS THAT STRONGEST INSTABILITY AXIS WITH MLCAPE UP TO 1K TO 2K J/KG WILL RESIDE NEAR OR JUST WEST OF THE FAR WEST AND SOUTHWEST CWA. MORE ROBUST CONVECTION LIKELY WILL RIDE THIS NORTH- NORTHWEST TO SOUTH- SOUTHEAST AXIS THIS EVENING. THEREFORE...IN PRESENCE OF DEEP LAYER SHEAR OF 40-50 KT...HIGHEST POTENTIAL FOR SEVERE WEATHER IS FAVORED TO BE WEST OF DIXON TO OTTAWA TO PAXTON LINE...FAIRLY SIMILAR TO RECENT RUNS OF HRRR. UPSCALE GROWTH INTO MCS MAY BE OCCURRING BY TIME STORMS ARRIVE...SO PRIMARY THREATS FROM ANY SEVERE STORMS LOOK TO BE DAMAGING WIND GUSTS AND LARGE HAIL. FOR REST OF AREA...IT APPEARS BAND OF SHOWERS AND EMBEDDED STORMS WILL STILL PRESS SOUTHEAST AHEAD OF COLD FRONT AS DEPICTED ON RECENT HRRR RUNS...BUT WITH MUCH LOWER CHANCE FOR STRONG TO SEVERE THUNDERSTORMS. CLOUD TO GROUND LIGHTNING POTENTIAL MAY BE LIMITED BUT ALSO NON-ZERO FOR NORTHEAST ILLINOIS AND NORTHWEST INDIANA...SOMETHING TO KEEP IN MIND FOR OUTDOOR ACTIVITIES THIS EVENING. COULD END UP BEING MORE OF A SHOWER/EMBEDDED THUNDER SCENARIO. FINALLY...ANY ORGANIZED THUNDERSTORMS COULD PRODUCE HEAVY DOWNPOURS WITH HIGH PWAT IN 1.7 TO 1.8 INCH RANGE SAGGING SOUTHWARD AHEAD OF THE FRONT. THUS GIVEN RECENT HEAVY RAINS...WILL ALSO NEED TO MONITOR FOR FLOOD POTENTIAL THIS EVENING EVEN IN FASTER STORM MOTIONS. OVERNIGHT LOWS WILL BE IN THE UPPER 60S TO LOWER 70S...WITH 60S DEWPOINTS YIELDING MUGGY CONDITIONS. RC && .LONG TERM... 329 PM CDT SUNDAY THROUGH SATURDAY... MAIN FORECAST CONCERNS/CHALLENGES FOR THE PERIOD REMAIN WITH AN ACTIVE WEATHER PATTERN WITH PERIODIC CHANCES FOR SHOWERS/THUNDERSTORMS CONTINUING NEXT WEEK. THE PERIOD WILL BEGIN WITH FRONTAL BOUNDARY STILL LIKELY LINGERING ACROSS THE SOUTHERN THIRD OF THE CWA...WHERE UPPER 60S DEWPOINTS WILL STILL LIKELY RESIDE. WHILE CONVECTION FROM THE OVERNIGHT WILL HAVE LIKELY EXITED THE AREA BY THE MORNING...THERE APPEARS TO BE A CHANCE FOR FURTHER DEVELOPMENT ACROSS EAST CENTRAL ILLINOIS AND PORTIONS OF NORTHWEST INDIANA MAINLY SOUTH OF PONTIAC ILLINOIS TO MOROCCO INDIANA LINE. FORECAST SOUNDINGS IN THESE LOCATIONS ARE INDICATING INCREASING INSTABILITY WITH LITTLE TO NO CIN DURING THE MORNING AND ALTHOUGH THE CHANCE FOR ADDITIONAL DEVELOPMENT IS LOW...THERE DOES APPEAR TO BE A SMALL WINDOW BEFORE THE AXIS OF BEST DEVELOPMENT ALONG THIS BOUNDARY PUSHES SOUTH OF THE CWA BY MIDDAY. THE AFTERNOON WILL LIKELY BE DRY WITH CLEARING SKIES...AND WITH TEMPERATURES INCREASING INTO THE 80S. WINDS NEAR THE LAKE WILL BEGIN OUT OF THE NORTHWEST TO NORTH AND WITH A SHIFT TO THE NORTHEAST/EAST LIKELY BY MIDDAY...LIMITING TEMPS TO THE 70S. CONDITIONS APPEAR TO BE QUIET SUNDAY EVENING AND THROUGH MUCH OF SUNDAY NIGHT. HOWEVER...ATTENTION TURNS BACK WEST TOWARDS INCREASING MID LEVEL ENERGY AND A STRENGTHENING LLJ. THESE FEATURES WILL ALLOW FOR SHOWER/THUNDERSTORM DEVELOPMENT WELL WEST OF THE CWA ACROSS IOWA FOR MOST OF THE NIGHT. SOME OF THIS DEVELOPMENT COULD POSSIBLY REACH THE FAR WESTERN CWA LATE SUNDAY NIGHT INTO MONDAY MORNING AND HAVE MAINTAINED SLIGHT CHANCE WORDING DURING THIS TIME. THE BETTER CHANCES WILL COME MONDAY MORNING WHEN SCATTERED THUNDERSTORM DEVELOPMENT APPEARS POSSIBLE. VEERING LLJ...APPROACHING MID LEVEL SUPPORT...AND GOOD MOIST/TEMP ADVECTION SHOULD PROVIDE AMPLE SUPPORT FOR AT LEAST SCATTERED THUNDERSTORM DEVELOPMENT. WITH THIS DECENT FORCING IN PLACE AND WHILE MODERATE/STRONG INSTABILITY ALOFT QUICKLY LIFTS NORTH ACROSS THE CWA...COULD ALLOW FOR SOME OF THESE STORMS TO BE STRONG TO SEVERE. THE LIKELY HAZARD WOULD BE FOR LARGE HAIL...BEFORE THIS DEVELOPMENT LIFTS NORTH OF THE CWA BY MIDDAY. GUIDANCE DOES VARY TO HOW MONDAY AFTERNOON WILL EVOLVE WITH REGARD TO ADDITIONAL THUNDERSTORM DEVELOPMENT...BUT IT WOULD APPEAR THAT THERE WILL BE A DRY WINDOW DURING THIS TIME. PERSISTING WARM/MOIST PUSH RIDING ALONG STRONG SOUTH TO SOUTHWEST WINDS WILL BE OBSERVED MONDAY AND IF THE CLOUDS CAN DEPART...TEMPS IN THE MID TO UPPER 80S WILL BE LIKELY. ANOTHER DECENT CHANCE FOR THUNDERSTORM ARRIVING MONDAY NIGHT WITH THE POTENTIAL FOR SOME OF THEM TO BE STRONG TO SEVERE. HAVE NOT INCREASE POPS DURING THIS TIME TOO MUCH OWING TO SOME UNCERTAINTY WITH COVERAGE AND EXACT TIMING. HOWEVER...WITH A SURFACE TROUGH AND FRONT PUSHING THROUGH THE AREA...DEVELOPMENT DEFINITELY APPEARS POSSIBLE. THIS FRONT SHOULD PUSH THROUGH THE CWA BY TUESDAY BUT THERE IS A POSSIBILITY THAT IT COULD LINGER ACROSS THE SOUTHERN CWA DURING THIS TIME. IF IT DOES...THERE WILL BE ADDITIONAL CHANCES OVER THE SOUTHERN CWA. RODRIGUEZ && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * MVFR CIGS AND MVFR VSBYS OVERNIGHT INTO SUNDAY MORNING. * WINDS BECOMING GUSTY FROM THE NORTHWEST BY LATE MORNING. * POSSIBLE LAKE BREEZE/NORTHEAST WIND SHIFT LATE SUNDAY AFTERNOON/ EARLY EVENING. ED F //DISCUSSION...UPDATED 06Z... ISOLATED SHOWERS OVER NE ILLINOIS IN THE WAKE OF THE LARGE COMPLEX OF RAIN AND STORMS HAVING EXITED TO THE SOUTH EARLIER TONIGHT TO ALSO SLIDE SE/DISSIPATE NEXT COUPLE OF HOURS. MEANWHILE MVFR CIGS WILL SPREAD OUT ACROSS THE AREA GIVEN THE LACK OF ANY STRONG DRYING WITH THE WEAK COLD FRONT POISED TO DROP SOUTH ACROSS THE AREA THE REST OF TONIGHT. ALONG WITH RESIDUAL LOW LEVEL MOISTURE... WET GROUND AND LIGHT WINDS EXPECT VSBYS TO ALSO LOWER IN LIGHT FOG OVERNIGHT HOWEVER LOW CLOUDS WILL PREVENT VSBYS FROM DROPPING BELOW 3-4 SM AT ORD AND MDW. NO RAIN EXPECTED SUNDAY WITH NORTHWEST WINDS INCREASING BEHIND THE COLD FRONT BY LATE MORNING AND BECOMING GUSTY. SOME QUESTION AS TO WHETHER A LAKE BREEZE BOUNDARY MAY DEVELOP AND REACH THE TERMINALS BY LATE IN THE DAY WITH FAIRLY STOUT NORTHWEST TO WEST GRADIENT WIND DIMINISHING POSSIBLY ENOUGH BY LATE AFTERNOON. ED F //ORD AND MDW CONFIDENCE...UPDATED 06Z... * MEDIUM TO HIGH FOR MVFR CIGS AND MVFR VSBYS OVERNIGHT INTO SUNDAY MORNING. * MEDIUM FOR WIND TRENDS TONIGHT AND SUNDAY. * HIGH FOR OTHER FORECAST ELEMENTS. ED F //OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z... * MONDAY...CHANCE OF SHRA/TSRA. STRONG/GUSTY SOUTHWEST WINDS. * TUESDAY...DRY/VFR. NORTHEAST WINDS. * WEDNESDAY AND THURSDAY...CHANCE OF SHRA/TSRA. EASTERLY WINDS. * FRIDAY...SLIGHT CHANCE OF SHRA/TSRA. NORTHEAST WINDS. && .MARINE... 325 AM CDT LOW PRESSURE AND ITS ASSOCIATED COLD FRONT EXITING THE WESTERN GREAT LAKES THIS MORNING WILL TURN WINDS NORTHWEST ACROSS LAKE MICHIGAN. WEAK HIGH PRESSURE BUILDING EAST QUICKLY BEHIND THE COLD FRONT WILL CAUSE WINDS TO SLACKEN BY EVENING FOLLOWED BY A PERIOD OF LIGHT AND VARIABLE WINDS TONIGHT BEFORE RETURN SOUTHERLY FLOW SETS UP MONDAY. SOUTH WINDS WILL INTENSIFY RAPIDLY MONDAY AHEAD OF FAIRLY STRONG LOW PRESSURE FOR THIS TIME OF YEAR. AS THE LOW MOVES TO THE U P OF MICHIGAN BY MONDAY EVENING AND THEN QUICKLY INTO ONTARIO MONDAY NIGHT... IT WILL DRIVE A COLD FRONT SOUTHEAST ACROSS THE LENGTH OF THE LAKE BY DAYBREAK TUESDAY. WINDS AND WAVES WILL THEN EASE TUESDAY AS THE GRADIENT RELAXES AS THE LOW AND FRONT PULL AWAY AND ANOTHER AREA OF HIGH PRESSURE BUILDS EAST INTO THE AREA TUESDAY NIGHT INTO WEDNESDAY. YET ANOTHER AREA OF LOW PRESSURE WILL MOVE EAST TO SOUTHERN LAKE MICHIGAN THURSDAY MORNING. ED F && .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/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
109 AM CDT SUN JUN 21 2015 .SHORT TERM... 329 PM CDT THROUGH TONIGHT... STILL LINGERING UNCERTAINTY REGARDING THE POTENTIAL FOR STRONG TO SEVERE STORMS THIS EVENING...WITH AN OVERALL TREND TOWARD A LOWER THREAT FOR THE THE NORTHEAST 1/2 TO 2/3 OF THE CWA. AS NOTED EARLIER...CLOUD COVER HAS OVERALL LIMITED DESTABILIZATION PROCESS EVEN IN PRESENCE OF GRADUALLY MOISTENING DEWPOINTS. ALSO A VERY STOUT WARM NOSE AT BASE OF EML ADVECTING WESTWARD CENTERED FROM 750-850 MB NOTED ON 18Z DVN SOUNDING WILL RESULT IN CAPPING/CINH AS DESTABILIZATION OCCURS LATE THIS AFTERNOON. ITS APPEARS THAT LINGERING CLUSTER OF THUNDERSTORMS OVER NORTHEAST IA AND NORTHWEST IL ON NOSE OF SPEED MAX SEEN ON W/V IMAGERY COULD BE MAIN FOCUS FOR WHAT OCCURS THIS EVENING...ONCE STRONGER FORCING ARRIVES AND WEAKENS THE CAP. IT STILL LOOKS THAT STRONGEST INSTABILITY AXIS WITH MLCAPE UP TO 1K TO 2K J/KG WILL RESIDE NEAR OR JUST WEST OF THE FAR WEST AND SOUTHWEST CWA. MORE ROBUST CONVECTION LIKELY WILL RIDE THIS NORTH- NORTHWEST TO SOUTH- SOUTHEAST AXIS THIS EVENING. THEREFORE...IN PRESENCE OF DEEP LAYER SHEAR OF 40-50 KT...HIGHEST POTENTIAL FOR SEVERE WEATHER IS FAVORED TO BE WEST OF DIXON TO OTTAWA TO PAXTON LINE...FAIRLY SIMILAR TO RECENT RUNS OF HRRR. UPSCALE GROWTH INTO MCS MAY BE OCCURRING BY TIME STORMS ARRIVE...SO PRIMARY THREATS FROM ANY SEVERE STORMS LOOK TO BE DAMAGING WIND GUSTS AND LARGE HAIL. FOR REST OF AREA...IT APPEARS BAND OF SHOWERS AND EMBEDDED STORMS WILL STILL PRESS SOUTHEAST AHEAD OF COLD FRONT AS DEPICTED ON RECENT HRRR RUNS...BUT WITH MUCH LOWER CHANCE FOR STRONG TO SEVERE THUNDERSTORMS. CLOUD TO GROUND LIGHTNING POTENTIAL MAY BE LIMITED BUT ALSO NON-ZERO FOR NORTHEAST ILLINOIS AND NORTHWEST INDIANA...SOMETHING TO KEEP IN MIND FOR OUTDOOR ACTIVITIES THIS EVENING. COULD END UP BEING MORE OF A SHOWER/EMBEDDED THUNDER SCENARIO. FINALLY...ANY ORGANIZED THUNDERSTORMS COULD PRODUCE HEAVY DOWNPOURS WITH HIGH PWAT IN 1.7 TO 1.8 INCH RANGE SAGGING SOUTHWARD AHEAD OF THE FRONT. THUS GIVEN RECENT HEAVY RAINS...WILL ALSO NEED TO MONITOR FOR FLOOD POTENTIAL THIS EVENING EVEN IN FASTER STORM MOTIONS. OVERNIGHT LOWS WILL BE IN THE UPPER 60S TO LOWER 70S...WITH 60S DEWPOINTS YIELDING MUGGY CONDITIONS. RC && .LONG TERM... 329 PM CDT SUNDAY THROUGH SATURDAY... MAIN FORECAST CONCERNS/CHALLENGES FOR THE PERIOD REMAIN WITH AN ACTIVE WEATHER PATTERN WITH PERIODIC CHANCES FOR SHOWERS/THUNDERSTORMS CONTINUING NEXT WEEK. THE PERIOD WILL BEGIN WITH FRONTAL BOUNDARY STILL LIKELY LINGERING ACROSS THE SOUTHERN THIRD OF THE CWA...WHERE UPPER 60S DEWPOINTS WILL STILL LIKELY RESIDE. WHILE CONVECTION FROM THE OVERNIGHT WILL HAVE LIKELY EXITED THE AREA BY THE MORNING...THERE APPEARS TO BE A CHANCE FOR FURTHER DEVELOPMENT ACROSS EAST CENTRAL ILLINOIS AND PORTIONS OF NORTHWEST INDIANA MAINLY SOUTH OF PONTIAC ILLINOIS TO MOROCCO INDIANA LINE. FORECAST SOUNDINGS IN THESE LOCATIONS ARE INDICATING INCREASING INSTABILITY WITH LITTLE TO NO CIN DURING THE MORNING AND ALTHOUGH THE CHANCE FOR ADDITIONAL DEVELOPMENT IS LOW...THERE DOES APPEAR TO BE A SMALL WINDOW BEFORE THE AXIS OF BEST DEVELOPMENT ALONG THIS BOUNDARY PUSHES SOUTH OF THE CWA BY MIDDAY. THE AFTERNOON WILL LIKELY BE DRY WITH CLEARING SKIES...AND WITH TEMPERATURES INCREASING INTO THE 80S. WINDS NEAR THE LAKE WILL BEGIN OUT OF THE NORTHWEST TO NORTH AND WITH A SHIFT TO THE NORTHEAST/EAST LIKELY BY MIDDAY...LIMITING TEMPS TO THE 70S. CONDITIONS APPEAR TO BE QUIET SUNDAY EVENING AND THROUGH MUCH OF SUNDAY NIGHT. HOWEVER...ATTENTION TURNS BACK WEST TOWARDS INCREASING MID LEVEL ENERGY AND A STRENGTHENING LLJ. THESE FEATURES WILL ALLOW FOR SHOWER/THUNDERSTORM DEVELOPMENT WELL WEST OF THE CWA ACROSS IOWA FOR MOST OF THE NIGHT. SOME OF THIS DEVELOPMENT COULD POSSIBLY REACH THE FAR WESTERN CWA LATE SUNDAY NIGHT INTO MONDAY MORNING AND HAVE MAINTAINED SLIGHT CHANCE WORDING DURING THIS TIME. THE BETTER CHANCES WILL COME MONDAY MORNING WHEN SCATTERED THUNDERSTORM DEVELOPMENT APPEARS POSSIBLE. VEERING LLJ...APPROACHING MID LEVEL SUPPORT...AND GOOD MOIST/TEMP ADVECTION SHOULD PROVIDE AMPLE SUPPORT FOR AT LEAST SCATTERED THUNDERSTORM DEVELOPMENT. WITH THIS DECENT FORCING IN PLACE AND WHILE MODERATE/STRONG INSTABILITY ALOFT QUICKLY LIFTS NORTH ACROSS THE CWA...COULD ALLOW FOR SOME OF THESE STORMS TO BE STRONG TO SEVERE. THE LIKELY HAZARD WOULD BE FOR LARGE HAIL...BEFORE THIS DEVELOPMENT LIFTS NORTH OF THE CWA BY MIDDAY. GUIDANCE DOES VARY TO HOW MONDAY AFTERNOON WILL EVOLVE WITH REGARD TO ADDITIONAL THUNDERSTORM DEVELOPMENT...BUT IT WOULD APPEAR THAT THERE WILL BE A DRY WINDOW DURING THIS TIME. PERSISTING WARM/MOIST PUSH RIDING ALONG STRONG SOUTH TO SOUTHWEST WINDS WILL BE OBSERVED MONDAY AND IF THE CLOUDS CAN DEPART...TEMPS IN THE MID TO UPPER 80S WILL BE LIKELY. ANOTHER DECENT CHANCE FOR THUNDERSTORM ARRIVING MONDAY NIGHT WITH THE POTENTIAL FOR SOME OF THEM TO BE STRONG TO SEVERE. HAVE NOT INCREASE POPS DURING THIS TIME TOO MUCH OWING TO SOME UNCERTAINTY WITH COVERAGE AND EXACT TIMING. HOWEVER...WITH A SURFACE TROUGH AND FRONT PUSHING THROUGH THE AREA...DEVELOPMENT DEFINITELY APPEARS POSSIBLE. THIS FRONT SHOULD PUSH THROUGH THE CWA BY TUESDAY BUT THERE IS A POSSIBILITY THAT IT COULD LINGER ACROSS THE SOUTHERN CWA DURING THIS TIME. IF IT DOES...THERE WILL BE ADDITIONAL CHANCES OVER THE SOUTHERN CWA. RODRIGUEZ && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * MVFR CIGS AND MVFR VSBYS OVERNIGHT INTO SUNDAY MORNING. * WINDS BECOMING GUSTY FROM THE NORTHWEST BY LATE MORNING. * POSSIBLE LAKE BREEZE/NORTHEAST WIND SHIFT LATE SUNDAY AFTERNOON/ EARLY EVENING. ED F //DISCUSSION...UPDATED 06Z... ISOLATED SHOWERS OVER NE ILLINOIS IN THE WAKE OF THE LARGE COMPLEX OF RAIN AND STORMS HAVING EXITED TO THE SOUTH EARLIER TONIGHT TO ALSO SLIDE SE/DISSIPATE NEXT COUPLE OF HOURS. MEANWHILE MVFR CIGS WILL SPREAD OUT ACROSS THE AREA GIVEN THE LACK OF ANY STRONG DRYING WITH THE WEAK COLD FRONT POISED TO DROP SOUTH ACROSS THE AREA THE REST OF TONIGHT. ALONG WITH RESIDUAL LOW LEVEL MOISTURE... WET GROUND AND LIGHT WINDS EXPECT VSBYS TO ALSO LOWER IN LIGHT FOG OVERNIGHT HOWEVER LOW CLOUDS WILL PREVENT VSBYS FROM DROPPING BELOW 3-4 SM AT ORD AND MDW. NO RAIN EXPECTED SUNDAY WITH NORTHWEST WINDS INCREASING BEHIND THE COLD FRONT BY LATE MORNING AND BECOMING GUSTY. SOME QUESTION AS TO WHETHER A LAKE BREEZE BOUNDARY MAY DEVELOP AND REACH THE TERMINALS BY LATE IN THE DAY WITH FAIRLY STOUT NORTHWEST TO WEST GRADIENT WIND DIMINISHING POSSIBLY ENOUGH BY LATE AFTERNOON. ED F //ORD AND MDW CONFIDENCE...UPDATED 06Z... * MEDIUM TO HIGH FOR MVFR CIGS AND MVFR VSBYS OVERNIGHT INTO SUNDAY MORNING. * MEDIUM FOR WIND TRENDS TONIGHT AND SUNDAY. * HIGH FOR OTHER FORECAST ELEMENTS. ED F //OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z... * MONDAY...CHANCE OF SHRA/TSRA. STRONG/GUSTY SOUTHWEST WINDS. * TUESDAY...DRY/VFR. NORTHEAST WINDS. * WEDNESDAY AND THURSDAY...CHANCE OF SHRA/TSRA. EASTERLY WINDS. * FRIDAY...SLIGHT CHANCE OF SHRA/TSRA. NORTHEAST WINDS. && .MARINE... 408 PM CDT THERE WAS A BRIEF PERIOD OF STRONGER WINDS EARLIER THIS AFTERNOON OVER THE SOUTHERN HALF OF THE LAKE...POSSIBLY UP TO 33 KT FOR A TIME. HOWEVER...WINDS HAVE SINCE DIMINISHED BACK TO THE 10 TO 15 KT RANGE IN THE NEAR TERM. THESE SPEEDS WITH GENERALLY SOUTHERLY FLOW WILL CONTINUE THIS EVENING AND INTO A PORTION OF THE OVERNIGHT...BEFORE A TROUGH AND FRONTAL BOUNDARY MOVE ACROSS THE REGION. THIS WILL ALLOW FOR A WIND SHIFT TO THE NORTHWEST AND ALTHOUGH THERE COULD BE A SMALL WINDOW OF 10 TO 20 KT WINDS WITH THIS WIND SHIFT...THE MORE PREVAILING SPEEDS WILL BE IN THE 10 TO 15 KT RANGE. NORTHERLY FLOW WILL REMAIN SUNDAY MORNING BUT DIMINISH AND THEN LIKELY BECOME MORE LIGHT AND VARIABLE THROUGH THE REMAINDER OF THE DAY. EXPECT WINDS TO SHIFT BACK MORE SOUTHERLY SUNDAY NIGHT INTO MONDAY...AND THEN INCREASE DURING THIS TIME. THIS INCREASE WILL ESPECIALLY OCCUR MONDAY AFTERNOON INTO THE EVENING...WHEN SOUTHERLY WINDS UP TO 30 KT ARE APPEARING LIKELY. THIS WILL PERSIST UNTIL ANOTHER SYSTEM MOVES THROUGH MONDAY NIGHT...WITH WINDS THEN EXPECTED TO TURN TO THE NORTHWEST WHILE DIMINISHING. 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/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1241 AM CDT SUN JUN 21 2015 .UPDATE... ISSUED AT 857 PM CDT SAT JUN 20 2015 A LINE OF STRONG TO SEVERE THUNDERSTORMS IS MOVING INTO WEST CENTRAL IL FROM THE NORTHWEST AHEAD OF A COLD FRONT MOVING SOUTHEASTWARD INTO THE AREA. SPC MESOANALYSIS SHOWING AROUND 4000 J/KG MLCAPE VALUES ALONG/SOUTH OF THE LINE WITH 30-50 KTS 0-6KM BULK SHEAR ACROSS NORTHERN HALF OF IL. AS A RESULT...ORGANIZED SEVERE CONVECTION SHOULD CONTINUE FOR MUCH OF THE EVENING THROUGH WEST CENTRAL IL AND A TORNADO WATCH REMAINS IN EFFECT UNTIL 11 PM. SEVERE WEATHER THREATS IN THIS AREA INCLUDE DAMAGING WIND GUSTS TO 60 MPH OR GREATER...LARGE HAIL...AND THE THREAT FOR AN ISOLATED TORNADO OR TWO. THUNDERSTORM ACTIVITY SHOULD SPREAD EAST AND SOUTH THROUGH CENTRAL/SE IL OVERNIGHT WITH SEVERE THUNDERSTORM THREAT SLOWLY DIMINISHING AND LARGELY SINKING SOUTHEASTWARD TOWARD SOUTH CENTRAL IL TOWARD POCKET OF STRONGEST INSTABILITY. HAVE SENT UPDATES TO FORECASTS FOR SHORT-TERM TRENDS IN THUNDERSTORM ACTIVITY LARGELY USING HRRR MODEL GUIDANCE WHICH APPEARS TO HAVE A GOOD HANDLE ON RECENT CONVECTIVE TRENDS. && .SHORT TERM...(TONIGHT) ISSUED AT 303 PM CDT SAT JUN 20 2015 THE REMNANTS OF TROPICAL STORM BILL DEFINED BY 1006 MB SURFACE LOW OVER SOUTHERN OHIO WITH 580 DM 500 MB LOW WILL TRACK INTO THE MID ATLANTIC STATES BY DAWN SUNDAY. BROKEN TO OVERCAST CLOUDS 1.5-3K FT OVER EASTERN HALF OF CWA WILL CONTINUE TO DECREASE FROM WEST TO EAST DURING LATE AFTERNOON AND EARLY EVENING. A CAPPED ATMOSPHERE IS KEEPING CENTRAL AND SOUTHEAST IL DRY SO FAR TODAY. HOWEVER, SHOWERS AND THUNDERSTORMS OVER EASTERN IA AND TRACKING EAST INTO NW IL AND SW WI MAINLY NORTH OF I-80 WILL EVOLVE INTO A LARGER MCS SYSTEM THAT WILL DROP SE TOWARD THE IL RIVER LATE THIS AFTERNOON/EARLY EVENING AND ACROSS MOST OF CENTRAL IL DURING THIS EVENING, REACHING SOUTHEAST IL OVERNIGHT WHERE CONVECTION CHANCES LOWER TO 30% FROM I-70 SOUTH. SPC HAS SLIGHT RISK OF SEVERE STORMS AS FAR SE AS A TAYLORVILLE TO DANVILLE LINE TONIGHT WHILE ENHANCED RISK WAS EXPANDED SE TO NEAR THE IL RIVER. AREAS WEST OF IL RIVER HAVE 30% RISK OF LARGE HAIL (2 INCH DIAMETER OR LARGER) AND DAMAGING WIND GUSTS ALONG WITH A 5% RISK OF TORNADOES. VERY UNSTABLE AIRMASS DEVELOPING LATE THIS AFTERNOON AND INTO THIS EVENING WITH CAPES RISING TO 2500-4500 J/KG IN WESTERN COUNTIES (EVEN NEAR 5000 J/KG BY 00Z/7 PM IN SW IA/NE MO AND FAR WEST CENTRAL IL AROUND QUINCY. MEANWHILE BULK SHEAR IS 30-40 KTS OVER NORTHERN CWA MAINLY FROM I-72 NORTH. PRECIPITABLE WATER VALUES OF 1.5-1.8 INCHES OVER IA THIS AFTERNOON TO SHIFT INTO CENTRAL IL THIS EVENING AND COULD CAUSE SOME LOCALLY HEAVY RAINS WITH THUNDERSTORMS ALONG WITH FREQUENT LIGHTNING. MUGGY LOWS TONIGHT IN THE LOWER 70S OVER CENTRAL/SE IL WITH UPPER 60S FAR NW BY GALESBURG. .LONG TERM...(SUNDAY THROUGH SATURDAY) ISSUED AT 303 PM CDT SAT JUN 20 2015 OUTFLOW BOUNDARY/FRONTAL BOUNDARY WILL REMAIN DRAPED OVER THE AREA TOMORROW AND THIS WILL BE THE FOCUS FOR ADDITIONAL SHOWERS AND THUNDERSTORMS. COULD BE SOME LINGERING THUNDERSTORMS FROM THE OVERNIGHT MCS THAT MOVES THROUGH. HOWEVER...BIG QUESTION IS HOW FAR SOUTH WILL THE OUTFLOW BOUNDARY GET BY MORNING. FORCING ALONG THE BOUNDARY AND MOISTURE WILL BE SUFFICIENT FOR MORE STORMS AND AGREE WITH SPC THAT A SLIGHT RISK IS WARRANTED OVER PARTS OF THE CWA TOMORROW THROUGH TOMORROW NIGHT. THIS BOUNDARY WILL THEN LIFT NORTHWARD A LITTLE THROUGH THE FIRST PART OF THE WEEK...SO PCPN CHANCES WILL SHIFT NORTHWARD SOME. HOWEVER...ALL MODELS FORECASTING STORMS TO CONTINUE THROUGH THE WEEK AND THIS WILL KEEP THE FRONT FROM GOING TOO FAR NORTH...AND WILL LIKELY BE OVER OR NEAR THE AREA THROUGH SATURDAY. THEREFORE...A CHANCE OF SHOWERS AND STORMS WILL CONTINUE THROUGH THE ENTIRE WEEK. THERE WILL BE SOME BREAKS IN THE PCPN...BUT TIMING OF WHEN THESE WILL BE THIS FAR OUT IS TOO UNCERTAIN. SO WILL JUST KEEP POPS THE WHOLE TIME AND THEN MAKE ADJUSTMENTS AS THE EVENTS GET CLOSER. TEMPS WILL BE WARM THROUGH THE PERIOD WITH THE WARMEST DAYS BEING MON THROUGH WED. A RELATIVELY STRONGER FRONT LOOKS TO MOVE THROUGH LATE IN THE WEEK AND THIS SHOULD BRING SLIGHTLY COOLER TEMPS FOR FRI AND SAT. GUIDANCE NUMBERS LOOK OK BUT WENT LITTLE WARMER IN THE EXTENDED THAN MEX GUIDANCE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1241 AM CDT SUN JUN 21 2015 WIDESPREAD SHRA AND SCATTERED TSRA ACROSS CENTRAL IL TERMINALS AT 06Z. EMBEDDED IFR/MVFR CONDITIONS MAINLY DUE TO LOW VISIBILITIES...HOWEVER PRIMARILY VFR CONDITIONS. PRECIPITATION/THUNDERSTORMS EXPECTED TO SHIFT SOUTHWARD OVERNIGHT AND WILL LINGER LONGEST AT KSPI-KDEC-KCMI...POTENTIALLY UNTIL AROUND 10-12Z. AS FRONTAL BOUNDARY CAUSING ACTIVITY SHIFTS BACK NORTHWARD DURING THE DAY SUNDAY...SHRA/TSRA WILL SPREAD BACK NORTHWARD ACROSS CENTRAL IL TERMINALS FROM AROUND 21-24Z AND HAVE INCLUDED VCTS BACK INTO TAFS AT THAT TIME. WINDS VARIABLE OVERNIGHT IN THE WAKE OF THUNDERSTORM ACTIVITY...TRANSITIONING BACK TO W-SW 5-10 KTS OVER NEXT SEVERAL HOURS && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...ONTON SHORT TERM...07 LONG TERM...AUTEN AVIATION...ONTON
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
350 AM AM EDT SUN JUN 21 2015 .UPDATE... THE SYNOPSIS...LONG TERM SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 323 AM EDT SUN JUN 21 2015 A MEANDERING FRONTAL ZONE IS EXPECTED TO LINGER NEARBY FOR THE BALANCE OF THE WEEK...RESULTING IN PERIODIC THUNDERSTORM CHANCES. && .NEAR TERM /TODAY/... ISSUED AT 323 AM EDT SUN JUN 21 2015 LINE OF THUNDERSTORMS CURRENTLY MOVING THROUGH THE LOCAL AREA HAS BEEN GRADUALLY WEAKENING WITH TIME. STILL SOME POCKETS OF HIGH WINDS ASSOCIATED WITH THIS FEATURE. OUTFLOW BOUNDARY CURRENTLY EXTENDS FROM SOUTHEAST INDIANA...THROUGH FAR SOUTHERN ILLINOIS...AND THEN BACK INTO NORTHWEST MISSOURI. ADDITIONAL CONVECTION IS OCCURRING OVER WESTERN ILLINOIS/NORTHERN MISSOURI ALONG THE TAIL END OF THIS BOUNDARY. CURRENT THUNDERSTORM ACTIVITY SHOULD BE MOVING EAST OF THE AREA OVER THE NEXT COUPLE OF HOURS. THUNDERSTORM POTENTIAL LATER TODAY ALONG COLD FRONT IS LESS CLEAR CUT BASED ON CURRENT ACTIVITY. STEEP LAPSE RATES OBSERVED ON LAST EVENING/S UPPER AIR HAVE LIKELY BEEN WORKED OVER...SO THINK SEVERE POTENTIAL FOR TODAY HAS DIMINISHED. POSSIBLE SOME OF THE ACTIVITY OVER WESTERN ILLINOIS MAY MOVE INTO THE SOUTHWEST ZONES LATER THIS MORNING. MODEL DATA ALSO SUGGEST SOME DEVELOPMENT POSSIBLE ALONG THE COLD FRONT OVER ABOUT THE SOUTHERN HALF OF THE FORECAST AREA BY EARLY AFTERNOON. WILL GO WITH CHANCE POPS ALL AREAS TODAY...WITH THE HIGHEST POPS OVER THE SOUTHERN ZONES. LOW LEVEL THICKNESSES SUGGEST THE GFS MOS HIGHS FOR TODAY MAY BE TOO WARM. WILL NUDGE THE GUIDANCE HIGHS DOWN A FEW DEGREES. && .SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/... ISSUED AT 323 AM EDT SUN JUN 21 2015 MODEL DATA SUGGEST FRONT WILL STALL OUT NEAR THE OHIO RIVER FOR A TIME EARLY TONIGHT BEFORE BEGINNING TO DRIFT BACK NORTH TOWARDS MORNING. LOW LEVEL JET WILL BE FOCUSED MUCH FARTHER WEST TONIGHT...SO DON/T THINK ANY NOCTURNAL CONVECTION WILL BE WIDESPREAD. WILL CONTINUE WITH CHANCE POPS...WITH THE HIGHEST POPS IN THE SOUTH. REMNANTS OF FRONT EXPECTED TO PUSH OFF TO THE NORTHEAST DURING THE DAY ON MONDAY AS LOW PRESSURE DEVELOPS OVER THE PLAINS. LAPSE RATES AND DEEP LAYER SHEAR FAVORABLE FOR SEVERE STORMS MONDAY AND MONDAY NIGHT. HOWEVER...A GOOD FOCUS FOR CONVECTION WILL BE LACKING WITH THE BETTER FORCING FARTHER NORTH OVER THE GREAT LAKES. IT IS POSSIBLE SOME CONVECTION MAY SNEAK INTO THE AREA MONDAY NIGHT FROM THE NORTH OR NORTHWEST. BASED ON ABOVE...WILL CONTINUE WITH CHANCE POPS FOR MONDAY AND MONDAY NIGHT. MODELS SUGGEST ANOTHER COLD FRONT WILL DROP INTO THE AREA ON TUESDAY...PROBABLY STALLING OUT NEAR THE OHIO RIVER TUESDAY NIGHT. WILL GO WITH CHANCE POPS AT THOSE TIMES AS WELL. BASED ON PROGGED LOW LEVEL THICKNESSES...THE GFS TEMPERATURE GUIDANCE IN THE LATER PERIODS OF THE SHORT TERM LOOK OK AT THIS POINT. ONLY MINOR ADJUSTMENTS PLANNED. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... ISSUED AT 350 AM EDT SUN JUN 21 2015 A FLAT UPPER RIDGE OVER THE SOUTHERN U.S. WILL RETROGRADE BACK INTO THE ROCKIES WHICH WILL ALLOW AN UPPER TROUGH TO DIG INTO THE GREAT LAKES BY NEXT WEEKEND. ACTIVE WEATHER WILL CONTINUE THROUGH THIS PERIOD AS A FRONTAL SYSTEM REMAINS ACROSS OUR AREA AND A SERIES OF SYSTEMS TRACK EAST SOUTHEAST ACROSS OUR REGION WITH THE MOST SIGNIFICANT ONES BEING EARLY THURSDAY AND SATURDAY. MODELS ARE CLOSE ENOUGH THAT THE SUPERBLEND INITIALIZATION WAS ACCEPTED FOR MOST ITEMS. WENT WITH CHANCE POPS MOST PERIODS WITH LIKELY POPS ACROSS OUR NORTH WEDNESDAY NIGHT AND SLIGHT CHANCE POPS MOST AREAS FRIDAY. TEMPERATURES WILL BE NEAR SEASONAL VALUES EARLY ON...BUT WILL BECOME COOLER TOWARDS NEXT WEEKEND. && .AVIATION /DISCUSSION FOR 210600Z TAF ISSUANCE/... ISSUED AT 1244 AM EDT SUN JUN 21 2015 RAPID REFRESH AND RADAR TRENDS SUGGEST EASTERN ILLINOIS BOW ECHO WILL BE NEAR LAF AND HUF AROUND 06Z AND TO IND AND BMG AROUND 08Z. SO...WILL HAVE A TEMPO MVFR THUNDERSTORM GROUP FOR AN HOUR OR TWO AT EACH SITE AND ALSO A WIND SHIFT TO NORTHWEST WITH GUSTS TO 40 KNOTS. AFTER THAT...COVERAGE LOOKS TO LOW TO MENTION ANY SHOWERS OR THUNDERSTORMS. MODEL RH TIME SECTIONS WERE THEN SHOWING AN INCREASE IN NEAR SURFACE MOISTURE THROUGH THE REST OF THE OVERNIGHT AND TIL AROUND 15Z. SO...COULD SEE STRATUS BEHIND THE CONVECTIVE ACTIVITY...BUT NOT CONFIDENT ENOUGH TO GO WITH CEILINGS WITH LACK OF STRONG LOW LEVEL INVERSION PER RAP SOUNDINGS. WILL TIME THE COLD FRONT TO LAF AROUND 15Z...IND AND HUF AROUND 18Z AND BMG AROUND 00Z. SOUTHWEST WINDS AROUND KNOTS WILL SHIFT TO NORTHWEST BEHIND THE FRONT AND BECOMING LIGHT AFTER DARK. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...JAS NEAR TERM...JAS SHORT TERM...JAS LONG TERM...JH AVIATION...MK/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
327 AM EDT SUN JUN 21 2015 .UPDATE... THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 323 AM EDT SUN JUN 21 2015 A MEANDERING FRONTAL ZONE IS EXPECTED TO LINGER NEARBY FOR THE BALANCE OF THE WEEK...RESULTING IN PERIODIC THUNDERSTORM CHANCES. && .NEAR TERM /TODAY/... ISSUED AT 323 AM EDT SUN JUN 21 2015 LINE OF THUNDERSTORMS CURRENTLY MOVING THROUGH THE LOCAL AREA HAS BEEN GRADUALLY WEAKENING WITH TIME. STILL SOME POCKETS OF HIGH WINDS ASSOCIATED WITH THIS FEATURE. OUTFLOW BOUNDARY CURRENTLY EXTENDS FROM SOUTHEAST INDIANA...THROUGH FAR SOUTHERN ILLINOIS...AND THEN BACK INTO NORTHWEST MISSOURI. ADDITIONAL CONVECTION IS OCCURRING OVER WESTERN ILLINOIS/NORTHERN MISSOURI ALONG THE TAIL END OF THIS BOUNDARY. CURRENT THUNDERSTORM ACTIVITY SHOULD BE MOVING EAST OF THE AREA OVER THE NEXT COUPLE OF HOURS. THUNDERSTORM POTENTIAL LATER TODAY ALONG COLD FRONT IS LESS CLEAR CUT BASED ON CURRENT ACTIVITY. STEEP LAPSE RATES OBSERVED ON LAST EVENING/S UPPER AIR HAVE LIKELY BEEN WORKED OVER...SO THINK SEVERE POTENTIAL FOR TODAY HAS DIMINISHED. POSSIBLE SOME OF THE ACTIVITY OVER WESTERN ILLINOIS MAY MOVE INTO THE SOUTHWEST ZONES LATER THIS MORNING. MODEL DATA ALSO SUGGEST SOME DEVELOPMENT POSSIBLE ALONG THE COLD FRONT OVER ABOUT THE SOUTHERN HALF OF THE FORECAST AREA BY EARLY AFTERNOON. WILL GO WITH CHANCE POPS ALL AREAS TODAY...WITH THE HIGHEST POPS OVER THE SOUTHERN ZONES. LOW LEVEL THICKNESSES SUGGEST THE GFS MOS HIGHS FOR TODAY MAY BE TOO WARM. WILL NUDGE THE GUIDANCE HIGHS DOWN A FEW DEGREES. && .SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/... ISSUED AT 323 AM EDT SUN JUN 21 2015 MODEL DATA SUGGEST FRONT WILL STALL OUT NEAR THE OHIO RIVER FOR A TIME EARLY TONIGHT BEFORE BEGINNING TO DRIFT BACK NORTH TOWARDS MORNING. LOW LEVEL JET WILL BE FOCUSED MUCH FARTHER WEST TONIGHT...SO DON/T THINK ANY NOCTURNAL CONVECTION WILL BE WIDESPREAD. WILL CONTINUE WITH CHANCE POPS...WITH THE HIGHEST POPS IN THE SOUTH. REMNANTS OF FRONT EXPECTED TO PUSH OFF TO THE NORTHEAST DURING THE DAY ON MONDAY AS LOW PRESSURE DEVELOPS OVER THE PLAINS. LAPSE RATES AND DEEP LAYER SHEAR FAVORABLE FOR SEVERE STORMS MONDAY AND MONDAY NIGHT. HOWEVER...A GOOD FOCUS FOR CONVECTION WILL BE LACKING WITH THE BETTER FORCING FARTHER NORTH OVER THE GREAT LAKES. IT IS POSSIBLE SOME CONVECTION MAY SNEAK INTO THE AREA MONDAY NIGHT FROM THE NORTH OR NORTHWEST. BASED ON ABOVE...WILL CONTINUE WITH CHANCE POPS FOR MONDAY AND MONDAY NIGHT. MODELS SUGGEST ANOTHER COLD FRONT WILL DROP INTO THE AREA ON TUESDAY...PROBABLY STALLING OUT NEAR THE OHIO RIVER TUESDAY NIGHT. WILL GO WITH CHANCE POPS AT THOSE TIMES AS WELL. BASED ON PROGGED LOW LEVEL THICKNESSES...THE GFS TEMPERATURE GUIDANCE IN THE LATER PERIODS OF THE SHORT TERM LOOK OK AT THIS POINT. ONLY MINOR ADJUSTMENTS PLANNED. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... ISSUED AT 216 PM EDT SAT JUN 20 2015 MODELS ARE CLOSE ENOUGH THAT THE SUPERBLEND INITIALIZATION WAS ACCEPTED FOR MOST ITEMS. AN UPPER RIDGE WILL REMAIN ACROSS THE SOUTH AND SOUTHWEST USA DURING MUCH OF THE LONG TERM...SETTING UP A NORTHWEST FLOW ALOFT ACROSS CENTRAL INDIANA. BY NEXT WEEKEND A TROUGH MAY DIG INTO THE AREA. THIS FLOW WILL ALLOW A SURFACE FRONT TO STALL OUT ACROSS CENTRAL INDIANA THROUGH THE EXTENDED. AS UPPER WAVES INTERACT WITH THE FRONT...SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE EACH DAY. MORE RAIN WILL BE POSSIBLE WITH THE UPPER TROUGH SATURDAY. TEMPERATURES WILL REMAIN NEAR TO ABOVE AVERAGE THROUGH MUCH OF THE PERIOD...WITH SOME COOLER CONDITIONS PERHAPS ARRIVING FOR NEXT WEEKEND. && .AVIATION /DISCUSSION FOR 210600Z TAF ISSUANCE/... ISSUED AT 1244 AM EDT SUN JUN 21 2015 RAPID REFRESH AND RADAR TRENDS SUGGEST EASTERN ILLINOIS BOW ECHO WILL BE NEAR LAF AND HUF AROUND 06Z AND TO IND AND BMG AROUND 08Z. SO...WILL HAVE A TEMPO MVFR THUNDERSTORM GROUP FOR AN HOUR OR TWO AT EACH SITE AND ALSO A WIND SHIFT TO NORTHWEST WITH GUSTS TO 40 KNOTS. AFTER THAT...COVERAGE LOOKS TO LOW TO MENTION ANY SHOWERS OR THUNDERSTORMS. MODEL RH TIME SECTIONS WERE THEN SHOWING AN INCREASE IN NEAR SURFACE MOISTURE THROUGH THE REST OF THE OVERNIGHT AND TIL AROUND 15Z. SO...COULD SEE STRATUS BEHIND THE CONVECTIVE ACTIVITY...BUT NOT CONFIDENT ENOUGH TO GO WITH CEILINGS WITH LACK OF STRONG LOW LEVEL INVERSION PER RAP SOUNDINGS. WILL TIME THE COLD FRONT TO LAF AROUND 15Z...IND AND HUF AROUND 18Z AND BMG AROUND 00Z. SOUTHWEST WINDS AROUND KNOTS WILL SHIFT TO NORTHWEST BEHIND THE FRONT AND BECOMING LIGHT AFTER DARK. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...JAS NEAR TERM...JAS SHORT TERM...JAS LONG TERM...50 AVIATION...MK/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
1244 AM EDT SUN JUN 21 2015 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 328 PM EDT SAT JUN 20 2015 A REMNANT TROPICAL SYSTEM WILL CONTINUE TO PUSH EASTWARD INTO TONIGHT. THEN A FRONTAL SYSTEM WILL MOVE INTO THE AREA EARLY SUNDAY AND LINGER INTO NEXT WEEK...RESULTING IN MORE PERIODIC THUNDERSTORM CHANCES. && .NEAR TERM /REST OF TONIGHT/... ISSUED AT 1007 PM EDT SAT JUN 20 2015 UPDATE... CURRENT FORECAST IS ON TRACK...SO NO CHANGES. LATEST RADAR MOSAIC SHOWS WIDESPREAD SHOWERS AND THUNDERSTORMS CURRENTLY TRACKING ACROSS CENTRAL AND NORTHERN ILLINOIS. NORTHWESTERN PORTIONS OF CENTRAL INDIANA COULD START SEEING SOME PRECIP WITHIN THE NEXT FEW HOURS WITH THE BULK OF THE CONVECTION MOVING IN AFTER MIDNIGHT. THE ONLY COUNTY STILL UNDER SLIGHT RISK OF SEVERE WEATHER IS WARREN COUNTY. UPDATED GRIDS HAVE BEEN SENT. PREVIOUS DISCUSSION... AN UPPER LEVEL SYSTEM IS SLOWLY MOVING SOUTHEASTWARD ACROSS PORTIONS OF EASTERN IOWA AND WESTERN WISCONSIN AND IS EXPECTED TO APPROACH THE NORTHWEST COUNTIES OF CENTRAL INDIANA AROUND MIDNIGHT TONIGHT. GUIDANCE SEEMS TO BE IN AGREEMENT WITH INITIALLY SHOWING THIS SYSTEM TO BE QUITE PROGRESSIVE AS IT MOVES TOWARD THE CENTRAL CWA DURING THE WEE EARLY HOURS SUNDAY MORNING...THEN BEGINS TO SLOW DOWN AND POSSIBLY EVEN STALL OUT AS IT DROPS SOUTH OF THE I 70 CORRIDOR. TRIED TO DEPICT POPS IN THE FORECAST AS IN THE HRRR AND OTHER NEAR TERM GUIDANCE WITH HIGHER POPS ACROSS THE NORTHWEST SHORTLY AFTER MIDNIGHT...THEN SLOWLY MOVING THIS SYSTEM SOUTHEAST ACROSS THE FORECAST AREA OVERNIGHT TIL IT REACHES THE SOUTHERN TWO TO THREE TIERS OF COUNTIES OF THE CWA AND EITHER SLOWS DOWN...WEAKENS...OR ALL TOGETHER JUST STALLS OUT AND LATER WEAKENS. SEVERE WX THREAT FOR TONIGHT VERY MARGINAL WITH ONLY WARREN COUNTY INCLUDED IN SPC/S DAY 1 SLIGHT RISK. SO SOME OF THESE STORMS DO HAVE THE POTENTIAL TO BE STRONG WITH DAMAGING WINDS AND HAIL AS THE MAIN THREATS. AND HEAVY DOWNPOURS AND CLOUD-TO-GROUND LIGHTNING NOT TO BE DISCOUNTED IN ANY THUNDERSTORMS. A BLEND OF GUIDANCE FOR LOW TEMPERATURES TONIGHT SEEMS REASONABLE AS THE NUMBERS ARE COMING IN SIMILAR FOR LOWS AROUND 70. && .SHORT TERM /SUNDAY THROUGH TUESDAY/... ISSUED AT 328 PM EDT SAT JUN 20 2015 A COLD FRONT WILL BEGIN MOVING INTO THE AREA LATER SUNDAY AFTERNOON FOLLOWING THE UPPER LEVEL SYSTEM MOVING SOUTHEAST ACROSS THE FORECAST AREA THAT MORNING. STEEP LAPSE RATES AND SUFFICIENT DEEP LAYER SHEAR SUGGEST AN ORGANIZED SEVERE THREAT IS POSSIBLE WITH THE FRONT...AND THE MAIN FOCUS FOR ANY STRONG TO SEVERE STORMS AS BEEN SHUNTED SOUTHWARD BASED ON THE FASTER TIMING OF THIS SYSTEM...SO NOW THE ONLY COUNTIES IN THE DAY 2 SLIGHT RISK FOR KIND CWA LIE JUST SOUTH OF THAT COMMON DIVIDING LINE THAT IT THE I 70 CORRIDOR. BASICALLY KEEPING HIGHER CHANCE POPS ACROSS THIS AREA TO THE SOUTH AND ONLY SLIGHT CHANCE TO ZERO POPS ACROSS THE NORTHERN COUNTIES. LATER SUNDAY NIGHT THE FRONT MAY SAG FAR ENOUGH TO THE SOUTH FOR A LULL IN THE THUNDERSTORM THREAT...BUT WILL KEEP SOME SMALL/WEAK CHANCES FOR POPS GOING SUNDAY NIGHT IN CASE THE FRONT ENDS UP MORE STATIONARY. APPEARS THE FRONT WILL BEGIN DRIFTING BACK TO THE NORTH DURING MONDAY AND TUESDAY SO WILL CONTINUE TO GO WITH PERIODIC CHANCES FOR SHOWERS AND THUNDERSTORMS BOTH DAYS. ALSO BASED ON PROGGED LOW LEVEL THICKNESSES...APPEARS TEMPERATURES AND DEW POINTS WILL BE GETTING INTO THAT UNCOMFORTABLE RANGE AGAIN WITH DEW POINTS IN THE MID 70S (OR HIGHER EVEN?) POSSIBLE...AND HIGHS IN THE MID/UPPER 80S TO AROUND 90 ACROSS THE SOUTHERN HALF OF THE CWA. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... ISSUED AT 216 PM EDT SAT JUN 20 2015 MODELS ARE CLOSE ENOUGH THAT THE SUPERBLEND INITIALIZATION WAS ACCEPTED FOR MOST ITEMS. AN UPPER RIDGE WILL REMAIN ACROSS THE SOUTH AND SOUTHWEST USA DURING MUCH OF THE LONG TERM...SETTING UP A NORTHWEST FLOW ALOFT ACROSS CENTRAL INDIANA. BY NEXT WEEKEND A TROUGH MAY DIG INTO THE AREA. THIS FLOW WILL ALLOW A SURFACE FRONT TO STALL OUT ACROSS CENTRAL INDIANA THROUGH THE EXTENDED. AS UPPER WAVES INTERACT WITH THE FRONT...SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE EACH DAY. MORE RAIN WILL BE POSSIBLE WITH THE UPPER TROUGH SATURDAY. TEMPERATURES WILL REMAIN NEAR TO ABOVE AVERAGE THROUGH MUCH OF THE PERIOD...WITH SOME COOLER CONDITIONS PERHAPS ARRIVING FOR NEXT WEEKEND. && .AVIATION /DISCUSSION FOR 210600Z TAF ISSUANCE/... ISSUED AT 1244 AM EDT SUN JUN 21 2015 RAPID REFRESH AND RADAR TRENDS SUGGEST EASTERN ILLINOIS BOW ECHO WILL BE NEAR LAF AND HUF AROUND 06Z AND TO IND AND BMG AROUND 08Z. SO...WILL HAVE A TEMPO MVFR THUNDERSTORM GROUP FOR AN HOUR OR TWO AT EACH SITE AND ALSO A WIND SHIFT TO NORTHWEST WITH GUSTS TO 40 KNOTS. AFTER THAT...COVERAGE LOOKS TO LOW TO MENTION ANY SHOWERS OR THUNDERSTORMS. MODEL RH TIME SECTIONS WERE THEN SHOWING AN INCREASE IN NEAR SURFACE MOISTURE THROUGH THE REST OF THE OVERNIGHT AND TIL AROUND 15Z. SO...COULD SEE STRATUS BEHIND THE CONVECTIVE ACTIVITY...BUT NOT CONFIDENT ENOUGH TO GO WITH CEILINGS WITH LACK OF STRONG LOW LEVEL INVERSION PER RAP SOUNDINGS. WILL TIME THE COLD FRONT TO LAF AROUND 15Z...IND AND HUF AROUND 18Z AND BMG AROUND 00Z. SOUTHWEST WINDS AROUND KNOTS WILL SHIFT TO NORTHWEST BEHIND THE FRONT AND BECOMING LIGHT AFTER DARK. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...SMF NEAR TERM...SMF/TDUD SHORT TERM...SMF LONG TERM...50 AVIATION...MK/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 DES MOINES IA
1151 PM CDT SAT JUN 20 2015 .UPDATE... ISSUED AT 645 PM CDT SAT JUN 20 2015 COLD FRONT MAKING RAPID PROGRESS TO THE SOUTHEAST WITH THE AIRMASS BECOMING MORE STABLE BEHIND THE FRONT. EXPECT THE STORMS TO TRANSITION TO A BIG WIND THREAT AS THEY PUSH TO THE SOUTHEAST BUT FOR CENTRAL IOWA...STORMS SHOULD EXIT THE REGION BY 02Z WITH CLEARING SKIES ACROSS THE EAST BY 03Z. THE REMAINDER OF TONIGHT WILL BE QUIET. && .SHORT TERM /TONIGHT/... ISSUED AT 224 PM CDT SAT JUN 20 2015 FORECAST PROBLEM FOR TONIGHT WILL BE THUNDERSTORM DEVELOPMENT ALONG A FRONTAL BOUNDARY MAKING ITS WAY ACROSS CENTRAL IOWA. AT 20Z THE FRONTAL BOUNDARY WAS LOCATED ROUGHLY FROM OMAHA TO ATLANTIC THEN NORTHEAST TO FORT DODGE TO FOREST CITY. THE MAIN AREA OF CONCERN WILL BE THE I-80 CORRIDOR AND ESPECIALLY SOUTH WHERE IT HAS BEEN SUNNY ALL DAY AND HAS BEEN ABLE TO REALLY DESTABILIZE. MESOANALYSIS SHOWS AN UNCAPPED ENVIRONMENT WITH 5000-6000 CAPES ACROSS THE AREAS WEST OF I-35 AND SOUTH OF I-80. ONCE THE FRONT PUSHES TO THIS AREA THUNDERSTORMS SHOULD RAPIDLY DEVELOP AND BECOME SEVERE. AT THIS TIME IT LOOKS LIKE THE DES MOINES METRO AREA WILL BE ON THE WESTERN FRINGE OF THE DEVELOPMENT SO BETWEEN 21Z AND 00Z WE SHOULD SEE STORMS BLOW UP. STRONG LOW LEVEL SHEAR IN THE VICINITY OF THE FRONT WILL ALLOW FOR ROBUST UPDRAFTS AND THE POTENTIAL FOR A FEW TORNADOES. LARGE HAIL WILL ALSO BE A THREAT. THE STORMS WILL EVENTUALLY EVOLVE INTO A WIND THREAT AS WELL BUT THAT MAY BE EAST/SOUTH OF OUR AREA. THE STORMS SHOULD BE EAST OF THE AREA BY 06Z HOWEVER THE HRRR IS INDICATING A SECONDARY LINE DEVELOPING ALONG THE 850 FRONT AND PUSHING SOUTH BEFORE STALLING NEAR THE IA/MO BORDER. IF THIS HAPPENS SOUTHERN IOWA WILL BE GETTING SOME HEAVY RAINFALL AMOUNTS. AT THIS TIME CONFIDENCE IS LOW ON THAT SECOND SHOT OF RAINFALL SO I HAVE GRIDS CLEARING AFTER 06Z. .LONG TERM /SUNDAY THROUGH SATURDAY/... ISSUED AT 224 PM CDT SAT JUN 20 2015 SURFACE HIGH PRESSURE WILL BUILD ACROSS THE MIDWEST INTO THE OHIO VALLEY ON SUNDAY. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO BE SOUTH OF IOWA IN THE MORNING. A SHORTWAVE MOVING THROUGH THE WESTERLY FLOW ALOFT ACROSS THE NORTHERN PLAINS WILL STRENGTHEN A SURFACE LOW IN THE DAKOTAS SUNDAY AFTERNOON. THE PRESSURE GRADIENT IS EXPECTED TO TIGHTEN WITH SOUTHERLY SURFACE FLOW LIFTING A WARM FRONT NORTH. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP NEAR THE FRONT LATE IN THE DAY WITH CONVECTION BECOMING MORE WIDESPREAD DURING THE EVENING AND OVERNIGHT HOURS. INSTABILITY AND DEEP LAYER SHEAR WILL BE SUFFICIENT FOR A FEW STRONG TO SEVERE THUNDERSTORMS WITH DAMAGING WINDS AND HAIL THE PRIMARY HAZARDS. PRECIPITATION WILL END FROM SOUTHWEST TO NORTHEAST MONDAY. WARM FRONT LOOKS TO SETUP ACROSS NORTHERN KANSAS AND MISSOURI ON TUESDAY...GRADUALLY LIFTING NORTH AND PROVIDING A FOCUS FOR ADDITIONAL SHOWERS AND THUNDERSTORMS. THE LATE AFTERNOON THROUGH THE OVERNIGHT HOURS IS THE MOST LIKELY TIMEFRAME FOR PRECIPITATION. ANOTHER SHORTWAVE TROUGH MOVES THROUGH THE NORTHERN PLAINS INTO THE MIDWEST ON WEDNESDAY. OCCASIONAL SHOWERS AND THUNDERSTORMS COULD FESTER THROUGH THE DAY AIDED BY MULTIPLE SHORTWAVES MOVING THROUGH THE UPPER FLOW AND NEARBY FRONTAL BOUNDARY. PATTERN LOOKS TO REMAIN ACTIVE THROUGH THE END OF THE WEEK INTO NEXT WEEKEND WITH WEST AND NORTHWEST UPPER FLOW...MULTIPLE OUTFLOW BOUNDARIES AND A SURFACE FRONT SUPPORTING CHANCES FOR THUNDERSTORMS. && .AVIATION...21/06Z ISSUED AT 1151 PM CDT SAT JUN 20 2015 THUNDERSTORMS ARE EXPECTED TO REMAIN SOUTH OF THE SITES OVERNIGHT WITH WINDS BECOMING LIGHT AND VARIABLE AND CIGS REMAINING VFR. SOME POTENTIAL FOR FOG TO DEVELOP OVERNIGHT WILL HAVE TO MONITOR SITES THAT HAD AN ABUNDANCE OF RAIN THIS EVENING FOR DEVELOPMENT. VFR CONDITIONS ARE FORECAST ON SUNDAY WITH WINDS BECOMING SOUTHERLY. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...FAB SHORT TERM...FAB LONG TERM...ANGLE AVIATION...DONAVON
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1202 AM CDT SUN JUN 21 2015 ...UPDATE TO AVIATION... .SYNOPSIS... ISSUED AT 1030 PM CDT SAT JUN 20 2015 WV IMAGERY AND 00Z UPPER AIR ANALYSIS INDICATE A NORTHWESTERLY FLOW ALOFT PREVAILING ACROSS THE WESTERN HIGH PLAINS AS A WEAK UPPER LEVEL RIDGE OF HIGH PRESSURE TRANSITIONS EASTWARD ACROSS THE INTERMOUNTAIN WEST. NEAR THE SURFACE, A NEAR STATIONARY FRONTAL BOUNDARY EXTENDS FROM SOUTHWESTERN KANSAS NORTHEAST ACROSS CENTRAL KANSAS. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 313 PM CDT SAT JUN 20 2015 UPPER LEVEL WESTERLY FLOW CONTINUES TO BE SITUATED ACROSS THE NORTHERN CONUS TODAY WITH UPPER LEVEL HIGH PRESSURE CENTERED OVER THE DESERT SOUTHWEST. A WEAK MID LEVEL DISTURBANCE WAS MOVING EAST OVER NEBRASKA THIS AFTERNOON WHILE A STRONGER WAVE WAS MOVING OVER MONTANA. A COOL FRONT WAS SLOWLY PUSHING SOUTH FROM EASTERN COLORADO INTO NORTH CENTRAL KANSAS BY EARLY AFTERNOON. THE FRONT SHOULD MOVE SOUTH A LITTLE MORE EARLY THIS EVENING BEFORE BECOMING STATIONARY AND THEN SLOWLY LIFTING BACK TO THE NORTH LATER TONIGHT. THE RAP AND HRRR MODELS INDICATE SOME CONVECTION BREAKING OUT ALONG THE FRONT LATE THIS AFTERNOON. THESE ARE THE ONLY MODELS THAT DO SO AS THE HIRES ARW/NMM MODELS AS WELL AS THE OPERATIONAL NAM AND GFS KEEP THINGS DRY. THE MESOSCALE MODELS HAVE BEEN SHOWING A TENDENCY FOR CONVECTIVE TEMPERATURES TO BE REACHED IN CENTRAL KANSAS WHICH WOULD EXPLAIN THE CONVECTION. FOR NOW WILL KEEP THE FORECAST DRY IN CENTRAL KANSAS. TEMPERATURES TONIGHT WILL CONTINUE FAIRLY MILD IN THE MID 60S ALONG THE COLORADO BORDER TO THE LOWER 70S IN SOUTH CENTRAL KANSAS. SOUTHERLY WINDS WILL INCREASE AGAIN ON SUNDAY BUT SHOULD NOT HAVE QUITE THE DOWNSLOPE COMPONENT AS TODAY. IN SPITE OF THIS, WARMER AIR IN THE MID LEVELS WILL BE SPREADING OUT OF THE WEST AS THE UPPER LEVEL HIGH PRESSURE IN THE WEST MOVES TOWARD THE PLAINS. HIGHS WILL AGAIN BE VERY WARM...IN THE 95-100 DEGREE RANGE. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 248 PM CDT SAT JUN 20 2015 UPPER LEVEL RIDGING WILL PERSIST ACROSS THE SOUTHERN ROCKIES AND SOUTHERN PLAINS THROUGH MIDWEEK BEFORE SHIFTING WESTWARD INTO THE ROCKIES BY THURSDAY AND THEN AMPLIFYING OVER THE WESTERN UNITED STATES INTO THE WEEKEND. THIS WILL GENERALLY BE A HOT PATTERN, WITH LITTLE IN THE WAY OF PRECIPITATION. WEAK COLD FRONTS MAY GET CLOSE ENOUGH TO WESTERN KANSAS LATE TUESDAY THROUGH FRIDAY, PARTICULARLY NEAR INTERSTATE 70 SO THAT A FEW THUNDERSTORMS ARE POSSIBLE. BUT THESE STORMS OUGHT TO BE ISOLATED TO SCATTERED; AND GIVEN THE WEAK WINDS AT UPPER LEVELS, WILL PROBABLY NOT BE SEVERE OTHER THAN AN ISOLATED DAMAGING WIND GUST. IF THE UPPER LEVEL RIDGE RETROGRADES BACK OVER UTAH BY FRIDAY AND SATURDAY AS THE MODELS SUGGEST, THEN HIGH TEMPERATURES COULD DROP BACK INTO THE UPPER 80S TO LOWER 90S STARTING FRIDAY, ALONG WITH A FEW THUNDERSTORMS AS THE COLD FRONT PASSES. BUT UNTIL THEN, EXPECT HIGHS TO BE IN THE 90S TO POSSIBLY NEAR 100F, WITH LOWS IN THE UPPER 60S TO LOWER 70S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1200 AM CDT SUN JUN 21 2015 VFR CONDITIONS ARE EXPECTED TO PREVAIL AT ALL TAF SITES THROUGH LATE SUNDAY AFTERNOON. LIGHT EASTERLY WINDS WILL PREVAIL ACROSS CENTRAL KANSAS OVERNIGHT AS A FRONTAL BOUNDARY REMAINS STALLED OUT FROM SOUTHWEST KANSAS NORTHEAST INTO CENTRAL KANSAS. WINDS SOUTH OF THE BOUNDARY WILL BE SOUTHERLY 5 TO 15KT. THE FRONTAL BOUNDARY WILL LIFT BACK TO THE NORTH SUNDAY TURNING WINDS SOUTHERLY ACROSS THE ENTIRE REGION WHILE INCREASING UP TO AROUND 15 TO 25KT BY SUNDAY AFTERNOON. && .PRELIMINARY POINT TEMPS/POPS... DDC 71 96 71 96 / 0 0 0 0 GCK 70 101 71 99 / 0 0 0 0 EHA 69 100 69 97 / 0 0 0 0 LBL 69 97 70 96 / 0 0 0 0 HYS 73 101 72 97 / 0 10 10 10 P28 73 96 73 95 / 0 0 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...JJOHNSON SHORT TERM...GERARD LONG TERM...FINCH AVIATION...JJOHNSON
AREA FORECAST DISCUSSION
NWS JACKSON KY
330 AM EDT SUN JUN 21 2015 .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 330 AM EDT SUN JUN 21 2015 TODAY/S FORECAST IS A BIT MORE COMPLICATED THAN I WOULD LIKE DUE TO UPSTREAM MCS AND THE EFFECT IT/S DEBRIS CLOUDS WILL HAVE ON POTENTIAL CONVECTIVE DEVELOPMENT LATER TODAY ACROSS OUR AREA. BASED ON RAW EXTRAPOLATION...THE LINE OF SHOWERS AND THUNDERSTORMS CURRENTLY OVER INDIANA WILL BE ENTERING OUR NORTHWEST COUNTIES BY AROUND DAWN. I EXPECT THIS LINE TO WEAKEN BUT A SMALL POP WILL BE INCLUDED UP NORTH EARLY ON TO ACCOUNT FOR THIS ACTIVITY. CONSIDERABLE MID AND HIGH LEVEL CLOUDINESS WILL LINGER THROUGH THE MORNING OVER THE OHIO VALLEY AND THIS SHOULD LIMIT DESTABILIZATION EARLY ON IN THE DAY DRAWING INTO QUESTION THE DEVELOPMENT OF ANOTHER COMPLEX OF STORMS SHOWN TO TAKE PLACE SO QUICKLY IN THE 21/00Z NAM OVER INDIANA AND OHIO. RECENT HRRR AND 21/00Z HIRES NMM SEEM MORE REASONABLE IN HOLDING OFF ANY SHOWER AND THUNDERSTORM DEVELOPMENT UNTIL LATER IN THE AFTERNOON. IT IS AT THIS TIME THAT AT LEAST SCATTERED THUNDERSTORMS WILL LIKELY DEVELOP OVER EASTERN KENTUCKY...AND THEY COULD BECOME QUITE STRONG AS THEY HAVE A RICH FUEL SOURCE OF LOW 70 DEGREE SURFACE DEWPOINTS TO TAP INTO. SPC CONTINUES TO HIGHLIGHT A GOOD CHUNK OF THE AREA IN A SLIGHT RISK AND WILL CONTINUE TO MENTION THIS IN OUR LOCAL HAZARDOUS WEATHER OUTLOOK. THUNDERSTORMS THAT DEVELOP THIS AFTERNOON WILL SETTLE SOUTHEAST AND WEAKEN DURING THE EVENING. LEFT OVER BOUNDARIES MAY THEN BE THE FOCUS FOR ADDITIONAL THUNDERSTORM ACTIVITY ON MONDAY AFTERNOON...BUT THESE SHOULD REMAIN WIDELY SCATTERED AS AN UPPER LEVEL RIDGE STARTS TO BUILD IN FROM THE WEST. HEAT AND HUMIDITY WILL BE ANOTHER CONCERN DURING THE SHORT TERM. CLOUD COVER EARLY IN THE DAY TODAY SHOULD SLOW OUR RISE A BIT...BUT STILL EXPECT TEMPS TO REACH AROUND 90 BY AFTERNOON AND THEN AGAIN MONDAY AFTERNOON. WITH DEWPOINTS PROGGED TO RISE INTO THE LOWER 70S FOR MOST LOCATIONS...AFTERNOON HEAT INDEX VALUES WILL RISE INTO THE MID TO UPPER 90S. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 330 AM EDT SUN JUN 21 2015 THE MODELS ARE GENERALLY IN GOOD AGREEMENT WITH THE LONG WAVE PATTERN THROUGH THE PERIOD. AN UPPER LEVEL RIDGE WILL START OUT ACROSS THE SOUTHERN PLAINS AND MISSISSIPPI VALLEY. THIS RIDGE WILL GRADUALLY WEAKEN AND GET DIRECTED TOWARD THE EAST...AS TRAVERSING NORTHERN STREAM SHORT WAVE ENERGY PROVIDES GLANCING BLOWS THROUGH EARLY NEXT WEEK. TOWARDS THE MIDDLE AND ESPECIALLY THE END OF NEXT WEEK...THE RIDGE WILL RE-ESTABLISH ITSELF ACROSS THE DESERT SOUTHWEST...ALLOWING FOR MORE TROUGHING TO RESIDE ACROSS THE MISSISSIPPI VALLEY. FOR EASTERN KENTUCKY...THIS WILL TRANSLATE INTO PLENTY OF HEAT AND HUMIDITY EARLY ON...ALONG WITH THE DAILY THREAT OF THUNDERSTORMS...MOST LIKELY PEAKING WITHIN THE NORMAL DIURNAL REGIME...ALTHOUGH AS MENTIONED PREVIOUSLY...LARGER THUNDERSTORM COMPLEX ACTIVITY WILL ALSO PLAY A ROLE. HIGHS WILL PEAK IN THE LOW 90S FOR MOST LOCATIONS THROUGH TUESDAY...BEFORE TAKING A BIT OF A HIT AS A SHEARED OUT COLD FRONT ATTEMPTS TO MOVE IN FROM THE NORTHWEST. HIGHS WILL DROP BACK INTO MAINLY THE 80S FOR THE SECOND HALF OF THE WORKWEEK...WITH SOME RELIEF FROM THE HUMIDITY BY THE START OF NEXT WEEKEND. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY EVENING) ISSUED AT 142 AM EDT SUN JUN 21 2015 PATCHY DENSE FOG HAS BEGUN TO FORM NOW THAT CLOUDS ARE SCATTERING OUT. HOWEVER...MID AND HIGH LEVEL CLOUDS WILL BE STREAMING IN QUICKLY FROM AN UPSTREAM THUNDERSTORM COMPLEX. THIS SHOULD ACT TO LIMIT THE FOG DEVELOPMENT AND LIKELY CAUSE IMPROVING CONDITIONS WHERE FOG HAS ALREADY SET UP. OTHERWISE...A WARM AND HUMID DAY IS ON THE WAY FOR SUNDAY. THERE REMAINS A POSSIBILITY FOR THUNDERSTORM DEVELOPMENT DURING THE AFTERNOON AND EVENING HOURS BUT TOO MUCH UNCERTAINTY EXISTS AT THIS TIME FOR MORE THAN A VCTS/CB MENTION IN THE TAFS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...ABE LONG TERM...GEOGERIAN AVIATION...ABE
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
449 AM EDT SUN JUN 21 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 449 AM EDT SUN JUN 21 2015 WV IMAGERY AND RAP ANALYSIS INDICATED A ZONAL PATTERN ACROSS THE NRN CONUS WITH A SHORTWAVE NOTED UPSTREAM OVER THE NRN MN. LINGERING LOW LEVEL MOISTURE ACROSS THE AREA HAS RESULTED IN THE DEVELOPMENT OF PATCHY FOG THIS MORNING. TODAY...WEAK SFC RIDGING BUILDING OVER THE AREA WILL ALLOW LAKE BREEZES TO DEVELOP BY AFTERNOON. AT SAME TIME MODEL CONSENSUS SHOWS MLCAPE VALUES COULD CLIMB NEAR 500 J/KG OVER MAINLY THE SCNTRL FCST AREA FROM NEAR ESC TO CRYSTAL FALLS. THIS INSTABILITY ALONG WITH THE FOCUS PROVIDED BY THE LAKE BREEZE BOUNDARIES MAY BE ENOUGH TO TRIGGER SOME ISOLD SHRA/TSRA OVER THE SCNTRL FCST AREA...ESPECIALLY WITH MODELS SHOWING HINT OF A SHORTWAVE MOVING THROUGH THE AREA LATE MORNING/EARLY AFTERNOON. WITH LIMITED INSTABILITY FARTHER NORTH AND SOME MID LEVEL CAPPING NEAR 700 MB...NO AFTERNOON PCPN IS EXPECTED OVER THE REST OF THE CWA. LOOK FOR HIGH TEMPS RANGING FROM THE MID TO UPPER 60S NORTH AND EAST TO THE LOWER 70S ALONG THE WISCONSIN BORDER COUNTIES. TONIGHT...MID-LVL RIDGING MOVING ACROSS THE AREA WILL KEEP THE FCST AREA DRY THROUGH MUCH OF THE NIGHT. INCREASING Q-VECT CONVERGENCE AND DEEP LAYER MOISTURE AHEAD OF A STRONG SHORTWAVE APPROACHING FROM THE NORTHERN PLAINS WILL BRING IN A CHANCE OF SHRA/TSRA TO THE FAR WESTERN CWA TOWARD 12Z MONDAY. HIGHER DEW POINTS IN THE UPPER 50S ADVECTING IN WITH A DEVELOPING SOUTHERLY FLOW AHEAD OF PLAINS SYSTEM WILL ALSO CONTRIBUTE TO MORE FOG/STRATUS FORMATION ACROSS MUCH OF THE CWA...ESPECIALLY LATE TONIGHT OVER THE EAST HALF OF UPPER MI...DOWNWIND OF LAKE MICHIGAN. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 352 AM EDT SUN JUN 21 2015 MAIN FORECAST CONCERN IS THE SETUP FOR MON WHEN TWO WAVES (ONE W OF OR AND WA AND ANOTHER OVER BC CANADA) MERGE AND SEND A POTENT SHORTWAVE THROUGH THE REGION. WHILE THERE IS SOME DISAGREEMENT/VARIABILITY...MODELS GENERALLY INDICATE A LOW AROUND 1000MB MOVING FROM CENTRAL/SRN MN TO THE CENTRAL U.P. MON AFTERNOON/EVENING. THE WARM FRONT ASSOCIATED WITH THE SYSTEM LOOKS TO HANG UP OVER CENTRAL OR NRN WI...WHICH IS SUFFICIENT TO KEEP LIKELY/CATEGORICAL POPS OVER THE CWA. THE FORECAST FOR MON IS EXTREMELY DEPENDENT ON CONVECTION AND EXACTLY WHERE THE WARM FRONT SETS UP. MORNING CONVECTION WILL PLAY A ROLE IN THE COMPLICATION...WITH AN UNKNOWN LEVEL OF CLEARING/DESTABILIZATION. CURRENT THINKING CONTINUES TO BE THAT EITHER A STRONG CONVECTIVE COMPLEX OR CLUSTER OF SUPERCELL STORMS WILL MOVE S OF THE CWA IN THE AFTERNOON/EVENING. HOWEVER...IF THE FRONT SURGES FARTHER N OR IF ENOUGH INSTABILITY CAN DEVELOP...SHEAR WILL BE VERY STRONG AND THE OVERALL SYSTEM QUITE POTENT SO SEVERE STORMS WOULD LIKELY RESULT...WITH LARGE HAIL...DAMAGING WINDS AND TORNADOES ALL CONDITIONALLY POSSIBLE. IT SEEMS THAT SOME LOCATIONS IN THE WI/MI REGION (LIKELY FROM CENTRAL WI TO LOWER MI) WILL SEE A SIGNIFICANT SEVERE EVENT. AT THIS TIME WILL CONTINUE TO FAVOR A MORE CLIMATOLOGICAL APPROACH (WHICH IS SUPPORTED BY THE GFS/ECMWF/GEM) WHICH KEEP STRONGER STORMS S OF THE CWA AND WILL NOT PUT ANY STRONG/SEVERE EMPHASIS INTO THE HWO. SHOULD SEE GRADUALLY CLEARING CONDITIONS BY TUE MORNING WITH HIGH PRESSURE DOMINATING THE CENTRAL U.S.. SHOULD SEE MARINE FOG NEAR ERN LAKE SUPERIOR MON NIGHT AS NW WINDS BEHIND THE SHORTWAVE SWEEP FOG ONSHORE. OTHERWISE...SUNNY SKIES WILL PREVAIL ON TUE. NEXT CHANCE OF SHOWERS AND POSSIBLE SOME THUNDER ARRIVES ON WED AFTERNOON AND CONTINUES OFF AND ON THROUGH THU AS A SHORTWAVE MOVES THROUGH THE AREA. LIMITED THUNDER POTENTIAL TO SLIGHT CHANCES GIVEN LIMITED INSTABILITY. AN UPPER TROUGH LOOKS TO BECOME DOMINANT OVER THE GREAT LAKES REGION...WHICH WILL MAKE FOR COOLER CONDITIONS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 127 AM EDT SUN JUN 21 2015 LOW LEVEL MOISTURE WILL REMAIN INTO SUNDAY AFTERNOON BEFORE DRIER AIR ARRIVES. UNTIL THEN...VLIFR CONDITIONS WILL BE EXPECTED AT ALL THE TAF SITES INTO SUN MORNING BEFORE A SLOW IMPROVEMENT TO VFR TAKES PLACE SUN AFTERNOON AND LASTS INTO SUN EVENING. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 449 AM EDT SUN JUN 21 2015 HIGH PRES OVER THE AREA TODAY AND TONIGHT WILL KEEP WINDS UNDER 20 KTS. A LOW PRES SYSTEM WILL THEN MOVE OVER THE UPPER GREAT LAKES MONDAY INTO MON EVENING. COLD ADVECTION ON THE BACK SIDE OF THIS LOW WILL SUPPORT WNW WINDS 20 TO 30 KTS MONDAY NIGHT INTO TUE MORNING...STRONGEST OVER THE EAST HALF OF LAKE SUPERIOR. HIGH PRES BUILDING BACK OVER THE AREA WILL THEN KEEP WINDS LIGHT AGAIN FROM LATE TUE INTO THU. LINGERING LOW-LVL MOISTURE WILL SUPPORT FOG ACROSS THE LAKE...THAT COULD BE LOCALLY DENSE FROM TODAY INTO MONDAY EVENING. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...VOSS LONG TERM...TITUS AVIATION...07 MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
353 AM EDT SUN JUN 21 2015 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 420 PM EDT SAT JUN 20 2015 WV IMAGERY AND RAP ANALYSIS INDICATED A ZONAL PATTERN ACROSS THE NRN CONUS. THE SHORTWAVE TROUGH THAT BROUGHT THE LARGE AREA OF RAIN THROUGH UPPER MI WAS EXITING THE AREA LEAVING MAINLY JUST PATCHY LIGHT RAIN OF DRIZZLE OVER THE NORTH AND EAST. ANOTHER TRAILING SHRTWV OVER NE MN SUPPORTED SCT SHRA FROM THE MN ARROWHEAD INTO WRN LAKE SUPERIOR. OTHER UPSTREAM SHORTWAVES WERE LOCATED OVER NRN ND AND SE SASK. TONIGHT...EXPECT ISOLD/SCT -SHRA INTO THE CWA THIS EVENING ASSOCIATED WITH THE MN SHRTWV THAT SHOULD DIMINISH AND END AFTER 03Z. OTHERWISE...WITH ABUNDANT LOW LEVEL MOISTURE OVER THE REGION...PATCHY FOG WILL SHOULD DEVELOP. NNW UPSLOPE 10-15 KNOT 950- 900 MB FLOW INTO N CNTRL UPPER MI MAY ALSO SUPPORT SOME DRIZZLE OVERNIGHT INTO EARLY SUNDAY. SUN...THERE MAY BE SOME ISOLATED LIGHT SHOWERS ASSOCIATED WITH THE SASK/ND SHRTWVS EARLY OVER THE NORTH. OTHERWISE...EXPECT A WEAK SFC RIDGE TO BUILD INTO THE AREA WITH MAINLY LIGHT WINDS ALLOWING LAKE BREEZES TO DEVELOP. MODEL CONSENSUS SHOWS MLCAPE VALUES COULD CLIMB INTO THE 500-1000 J/KG RANGE OVER MAINLY THE SRN CWA FROM NEAR IMT- MNM. THIS MAY BE ENOUGH TO ALLOW SOME SHRA/TSRA TO DEVELOP...ESPECIALLY NEAR THE LAKE MI BREEZE BOUNDARY. WITH LIMITED INSTABILITY FARTHER NORTH AND SOME MID LEVEL CAPPING NEAR 700 MB...NO AFTERNOON PCPN IS EXPECTED OVER THE REST OF THE CWA. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 352 AM EDT SUN JUN 21 2015 MAIN FORECAST CONCERN IS THE SETUP FOR MON WHEN TWO WAVES (ONE W OF OR AND WA AND ANOTHER OVER BC CANADA) MERGE AND SEND A POTENT SHORTWAVE THROUGH THE REGION. WHILE THERE IS SOME DISAGREEMENT/VARIABILITY...MODELS GENERALLY INDICATE A LOW AROUND 1000MB MOVING FROM CENTRAL/SRN MN TO THE CENTRAL U.P. MON AFTERNOON/EVENING. THE WARM FRONT ASSOCIATED WITH THE SYSTEM LOOKS TO HANG UP OVER CENTRAL OR NRN WI...WHICH IS SUFFICIENT TO KEEP LIKELY/CATEGORICAL POPS OVER THE CWA. THE FORECAST FOR MON IS EXTREMELY DEPENDENT ON CONVECTION AND EXACTLY WHERE THE WARM FRONT SETS UP. MORNING CONVECTION WILL PLAY A ROLE IN THE COMPLICATION...WITH AN UNKNOWN LEVEL OF CLEARING/DESTABILIZATION. CURRENT THINKING CONTINUES TO BE THAT EITHER A STRONG CONVECTIVE COMPLEX OR CLUSTER OF SUPERCELL STORMS WILL MOVE S OF THE CWA IN THE AFTERNOON/EVENING. HOWEVER...IF THE FRONT SURGES FARTHER N OR IF ENOUGH INSTABILITY CAN DEVELOP...SHEAR WILL BE VERY STRONG AND THE OVERALL SYSTEM QUITE POTENT SO SEVERE STORMS WOULD LIKELY RESULT...WITH LARGE HAIL...DAMAGING WINDS AND TORNADOES ALL CONDITIONALLY POSSIBLE. IT SEEMS THAT SOME LOCATIONS IN THE WI/MI REGION (LIKELY FROM CENTRAL WI TO LOWER MI) WILL SEE A SIGNIFICANT SEVERE EVENT. AT THIS TIME WILL CONTINUE TO FAVOR A MORE CLIMATOLOGICAL APPROACH (WHICH IS SUPPORTED BY THE GFS/ECMWF/GEM) WHICH KEEP STRONGER STORMS S OF THE CWA AND WILL NOT PUT ANY STRONG/SEVERE EMPHASIS INTO THE HWO. SHOULD SEE GRADUALLY CLEARING CONDITIONS BY TUE MORNING WITH HIGH PRESSURE DOMINATING THE CENTRAL U.S.. SHOULD SEE MARINE FOG NEAR ERN LAKE SUPERIOR MON NIGHT AS NW WINDS BEHIND THE SHORTWAVE SWEEP FOG ONSHORE. OTHERWISE...SUNNY SKIES WILL PREVAIL ON TUE. NEXT CHANCE OF SHOWERS AND POSSIBLE SOME THUNDER ARRIVES ON WED AFTERNOON AND CONTINUES OFF AND ON THROUGH THU AS A SHORTWAVE MOVES THROUGH THE AREA. LIMITED THUNDER POTENTIAL TO SLIGHT CHANCES GIVEN LIMITED INSTABILITY. AN UPPER TROUGH LOOKS TO BECOME DOMINANT OVER THE GREAT LAKES REGION...WHICH WILL MAKE FOR COOLER CONDITIONS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 127 AM EDT SUN JUN 21 2015 LOW LEVEL MOISTURE WILL REMAIN INTO SUNDAY AFTERNOON BEFORE DRIER AIR ARRIVES. UNTIL THEN...VLIFR CONDITIONS WILL BE EXPECTED AT ALL THE TAF SITES INTO SUN MORNING BEFORE A SLOW IMPROVEMENT TO VFR TAKES PLACE SUN AFTERNOON AND LASTS INTO SUN EVENING. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 420 PM EDT SAT JUN 20 2015 TYPICAL SUMMERTIME CONDITIONS WITH GENERALLY LIGHT WINDS WILL DOMINATE ACROSS LAKE SUPERIOR THROUGH THE FCST PERIOD. WITH WEAK HIGH PRES BUILDING INTO THE AREA BEHIND THE DISTURBANCE MOVING OUT OF THE AREA TONIGHT...LIGHTER WINDS WILL FOLLOW FOR THE LAST HALF THE WEEKEND. THESE LIGHT WINDS...UNDER 20KT...WILL LIKELY CONTINUE THRU THE FIRST HALF OF NEXT WEEK AS A WEAK SUMMERTIME PRES GRADIENT SHOULD PREVAIL. THE RAIN TODAY WILL SUPPORT FOG ACROSS THE LAKE...THAT COULD BE LOCALLY DENSE. EXPECT THE FOG TO LINGER INTO EARLY NEXT WEEK DUE TO A LACK OF STRONG ADVECTION OF DRIER AIR. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...TITUS AVIATION...07 MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
129 AM EDT SUN JUN 21 2015 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 420 PM EDT SAT JUN 20 2015 WV IMAGERY AND RAP ANALYSIS INDICATED A ZONAL PATTERN ACROSS THE NRN CONUS. THE SHORTWAVE TROUGH THAT BROUGHT THE LARGE AREA OF RAIN THROUGH UPPER MI WAS EXITING THE AREA LEAVING MAINLY JUST PATCHY LIGHT RAIN OF DRIZZLE OVER THE NORTH AND EAST. ANOTHER TRAILING SHRTWV OVER NE MN SUPPORTED SCT SHRA FROM THE MN ARROWHEAD INTO WRN LAKE SUPERIOR. OTHER UPSTREAM SHORTWAVES WERE LOCATED OVER NRN ND AND SE SASK. TONIGHT...EXPECT ISOLD/SCT -SHRA INTO THE CWA THIS EVENING ASSOCIATED WITH THE MN SHRTWV THAT SHOULD DIMINISH AND END AFTER 03Z. OTHERWISE...WITH ABUNDANT LOW LEVEL MOISTURE OVER THE REGION...PATCHY FOG WILL SHOULD DEVELOP. NNW UPSLOPE 10-15 KNOT 950- 900 MB FLOW INTO N CNTRL UPPER MI MAY ALSO SUPPORT SOME DRIZZLE OVERNIGHT INTO EARLY SUNDAY. SUN...THERE MAY BE SOME ISOLATED LIGHT SHOWERS ASSOCIATED WITH THE SASK/ND SHRTWVS EARLY OVER THE NORTH. OTHERWISE...EXPECT A WEAK SFC RIDGE TO BUILD INTO THE AREA WITH MAINLY LIGHT WINDS ALLOWING LAKE BREEZES TO DEVELOP. MODEL CONSENSUS SHOWS MLCAPE VALUES COULD CLIMB INTO THE 500-1000 J/KG RANGE OVER MAINLY THE SRN CWA FROM NEAR IMT- MNM. THIS MAY BE ENOUGH TO ALLOW SOME SHRA/TSRA TO DEVELOP...ESPECIALLY NEAR THE LAKE MI BREEZE BOUNDARY. WITH LIMITED INSTABILITY FARTHER NORTH AND SOME MID LEVEL CAPPING NEAR 700 MB...NO AFTERNOON PCPN IS EXPECTED OVER THE REST OF THE CWA. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 310 PM EDT SAT JUN 20 2015 UPPER GREAT LAKES REGION WILL STILL BE UNDER THE INFLUENCE OF A HIGH PRESSURE RIDGE AT THE START OF THE LONG TERM PERIOD...BUT ITS INFLUENCE WILL BE SHORT LIVED AS A POTENT SHORTWAVE AND ASSOCIATED LOW PRESSURE SYSTEM WILL SWEEP ACROSS THE AREA ON MONDAY. THE SHORTWAVE THAT WILL AFFECT THE AREA ON MONDAY IS ACTUALLY TWO SEPARATE WAVES AT THIS TIME...ONE OVER BRITISH COLUMBIA AND THE OTHER OVER THE PACIFIC TO THE WEST OF OREGON. THESE TWO WAVES WILL MERGE OVER THE NORTHERN ROCKIES TOMORROW AND THEN QUICKLY SHIFT EAST INTO THE AREA FOR MONDAY. A LOW AVERAGING 1000MB WILL SLIDE NORTHEAST...TRACKING FROM EASTERN WYOMING ON SUNDAY AFTERNOON...TO MINNESOTA ON MONDAY AFTERNOON AND THEN ACROSS THE UPPER GREAT LAKES ON MONDAY NIGHT. MUCH OF THE FORECAST DEPENDS BOTH ON THE TRACK OF THE SHORTWAVE AND THE DEVELOPMENT OF CONVECTION ALONG THE WARM FRONT AHEAD OF THE LOW. LATEST MODEL RUNS SHOW THE SHORTWAVE TRACKING ACROSS SOUTHERN UPPER MICHIGAN OR NORTHERN WISCONSIN...WITH THE WARM FRONT LIKELY LOCATED IN NORTHERN/CENTRAL WISCONSIN. THAT IS CLOSE ENOUGH TO CONTINUE TO SHOW LIKELY TO DEFINITE POPS SPREADING EAST INTO THE AREA ON MONDAY MORNING AND CONTINUING INTO EARLY MONDAY EVENING AS THE MAIN FORCING MOVES THROUGH THE UPPER GREAT LAKES. THE POSITION OF THE WARM FRONT WILL DETERMINE SEVERE WEATHER POTENTIAL...AS THAT WILL BE THE AREA WHERE THE NOSE OF THE 35-40KT 850MB JET AND INSTABILITY GRADIENT WILL BE LOCATED. WHILE SOME MODELS DO TRY TO SHIFT IT NORTH INTO OUR AREA...BELIEVE THAT CONVECTION AND POSSIBLE MCS THAT DEVELOPS UPSTREAM IN MINNESOTA ON SUNDAY NIGHT WILL SUPPRESS THE BOUNDARY FARTHER TO THE SOUTH. ASSUMING THAT OCCURS...THE BETTER INSTABILITY WILL BE WELL TO THE SOUTH OF THE AREA AND THE GRADIENT SOMEWHERE IN CENTRAL/NORTHERN WISCONSIN. THINK THE LATEST DAY 3 OUTLOOK FROM SPC HAS A GOOD HANDLE ON WHERE THE STRONGEST STORMS WILL BE AND GENERALLY TO THE SOUTH OF THE U.P.. WILL CONTINUE TO MENTION SLIGHT/CHANCE THUNDERSTORMS OVER THE SOUTHERN HALF TO TWO-THIRDS OF THE CWA WHICH IS CLOSE ENOUGH TO POTENTIAL EXPERIENCE SOME RUMBLES OF THUNDER. WITH THE DYNAMICS OF THE SYSTEM...IF THE INSTABILITY OR WARM FRONT SHIFTS FARTHER TO THE NORTH...SEVERE STORMS WOULD BE POSSIBLE. AS THE LOW DEPARTS ON MONDAY NIGHT...EXPECT A WEST TO EAST DIMINISHMENT OF POPS AND CLOUD COVER ACROSS THE AREA. HAVE TRENDED WINDS UP BASED OFF ALL OF THE LATEST RUNS...WITH 925MB WINDS AROUND 35KTS. THAT WIND WILL LIMIT THE POTENTIAL FOR FOG ON MONDAY NIGHT ACROSS THE U.P.. THINK THE MAIN AREAS THAT WILL SEE FOG WILL BE ALONG THE LAKE MICHIGAN SHORELINE ON MONDAY EVENING AND SHORELINES ALONG CENTRAL/EASTERN LAKE SUPERIOR AS THE WINDS TURN TO THE NORTHWEST AND PUSH THE FOG ONSHORE. WINDS WILL BE DECREASING ON TUESDAY. THE AREA WILL BE UNDER WEST-NORTHWEST FLOW ALOFT FOR TUESDAY AND WEDNESDAY...AS A HIGH PRESSURE RIDGE MOVES OVER THE AREA FOR TUESDAY AND THEN DEPARTS ON WEDNESDAY AS THE PARENT HIGH MOVES INTO THE OHIO RIVER VALLEY. WHILE THE RIDGE IS OVER THE AREA...EXPECT DRY CONDITIONS AND TEMPERATURES TO BE NEAR NORMAL. THE NEXT SHORTWAVE WILL MOVE THROUGH THE AREA SOMETIME BETWEEN LATE WEDNESDAY AFTERNOON AND THURSDAY...THROUGH THE WEST-NORTHWEST FLOW ALOFT. WITH THE SOURCE REGION...AND THE WARM FRONT SITUATED OVER THE CENTRAL PLAINS...EXPECT MOISTURE TO BE LIMITED AND WILL ONLY INCLUDE SLIGHT/CHANCE POPS FOR THE PASSAGE OF THE WAVE. INSTABILITY IS ALSO LIMITED AND WILL KEEP VALUES CAPPED AT SLIGHT CHANCES...BUT WILL NEED TO WATCH DIURNAL HEATING ON THURSDAY...WHICH COULD INCREASE POTENTIAL SOME. A WEAK HIGH WILL MOVE OVER THE AREA ON THURSDAY NIGHT AND THE FIRST PART OF FRIDAY BEFORE ANOTHER SHORTWAVE DROPS SOUTHEAST INTO THE AREA FOR LATER FRIDAY INTO SATURDAY. WHILE THERE IS THE POTENTIAL FOR RAIN DURING THIS PERIOD...THE MORE NOTABLE ITEM IS THE AMPLIFICATION OF AN UPPER TROUGH OVER THE GREAT LAKES REGION FOR NEXT WEEKEND AND LIKELY CONTINUING INTO NEXT WEEK. BOTH THE ECMWF/GFS ENSEMBLES SUPPORT THAT IDEA...AND EVEN SHOW HINTS OF THAT TROUGH REMAINING IN PLACE TOWARDS THE FOURTH OF JULY. IF THAT SETUP OCCURS...THE U.P. WOULD EXPERIENCE A COOL AND DRY PERIOD OF WEATHER FOR THE END OF JUNE AND START OF JULY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 127 AM EDT SUN JUN 21 2015 LOW LEVEL MOISTURE WILL REMAIN INTO SUNDAY AFTERNOON BEFORE DRIER AIR ARRIVES. UNTIL THEN...VLIFR CONDITIONS WILL BE EXPECTED AT ALL THE TAF SITES INTO SUN MORNING BEFORE A SLOW IMPROVEMENT TO VFR TAKES PLACE SUN AFTERNOON AND LASTS INTO SUN EVENING. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 420 PM EDT SAT JUN 20 2015 TYPICAL SUMMERTIME CONDITIONS WITH GENERALLY LIGHT WINDS WILL DOMINATE ACROSS LAKE SUPERIOR THROUGH THE FCST PERIOD. WITH WEAK HIGH PRES BUILDING INTO THE AREA BEHIND THE DISTURBANCE MOVING OUT OF THE AREA TONIGHT...LIGHTER WINDS WILL FOLLOW FOR THE LAST HALF THE WEEKEND. THESE LIGHT WINDS...UNDER 20KT...WILL LIKELY CONTINUE THRU THE FIRST HALF OF NEXT WEEK AS A WEAK SUMMERTIME PRES GRADIENT SHOULD PREVAIL. THE RAIN TODAY WILL SUPPORT FOG ACROSS THE LAKE...THAT COULD BE LOCALLY DENSE. EXPECT THE FOG TO LINGER INTO EARLY NEXT WEEK DUE TO A LACK OF STRONG ADVECTION OF DRIER AIR. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...SRF AVIATION...07 MARINE...JLB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1154 PM CDT SAT JUN 20 2015 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 359 PM CDT SAT JUN 20 2015 WE REMAIN WITHIN A BELT OF RATHER HEALTHY WESTERLIES TODAY...THOUGH WATER VAPOR IMAGERY SHOWS WE ARE IN A ZONE OF SUBSIDENCE AND DRYING IN THE WAKE OF THE WAVE THAT PUSHED THE SHOWERS AND THUNDERSTORMS ACROSS THE REGION THIS MORNING. AT THE SFC...A TROUGH WITH A WIND SHIFT OVER TO THE NW HAD PUSHED TO ABOUT I-35 AS OF 230 PM. SPC MESO- ANALYSIS SHOWS 500-1500 J/KG OF MLCAPE ACROSS MOST OF THE AREA. HOWEVER...VIEW OUT THE WINDOW AND ON VISIBLE SATELLITE SHOWS THE CU FIELD ASSOCIATED WITH THIS INSTABILITY HAS A RATHER STABLE LOOK TO IT...SO NOT ANTICIPATING MUCH IN THE WAY OF PRECIP THIS AFTERNOON. SOME OF THE HI-RES CAMS /ESPECIALLY THE HRRR/ CONTINUE TO DEVELOP SOME ISO/SCT SHOWERS ALONG/AHEAD OF THE TROUGH FROM EC MN INTO WC MN...SO HAVE CONTINUED MENTION OF 20/30 POPS THIS AFTERNOON IN OUR EAST TO ACCOUNT FOR THAT. NEXT AREA TO WATCH FOR PRECIP THIS EVENING IS WRN MN. IR IMAGERY SHOWS A SHORT WAVE WORKING ACROSS NW SODAK. STARTING TO SEE STORMS BUBBLE UP FROM NW SODAK INTO NC NODAK BENEATH A PLUME OF STEEP MID- LEVEL LAPSE RATES. THE HRRR HAS PICKED UP ON THIS BIT OF FORCING...SHOWING A BROKEN LINE OF THUNDERSTORMS MOVING ACROSS THE DAKOTAS THE REST OF THE AFTERNOON AND MAKING A RUN FOR WEST CENTRAL MN BETWEEN 7PM AND 10PM. AS THESE STORMS RUN TOWARD MN...THE RAP SHOWS MUCAPE WANING...SO THINK THESE WILL RUN OUT OF STEAM BEFORE GETTING INTO MN...THOUGH WE MAY NEED TO GET SOME LOW PROBS FOR -SHRA INTO OUR WEST THIS EVENING. NEXT FEATURE OF INTEREST IS A STRONG SHORTWAVE EVIDENT ON WATER VAPOR IMAGERY THAT BETWEEN 7 AM AND 3 PM HAS GONE FROM OFF THE OREGON COAST TO WRN MT. DETERMINISTIC MODELS AND CAMS ARE IN GOOD AGREEMENT ON THIS WAVE KICKING OFF ANOTHER MCS OVER THE BLACK HILLS TONIGHT THAT WILL DIVE SE TOWARD OMAHA. AS IT DOES SO...ITS OUTFLOW BOUNDARY WILL BECOME A WARM FRONT THAT WILL BEGIN LIFTING NORTH ACROSS NEBRASKA TOWARD SW MN SUNDAY AFTERNOON. NAM/GFS SHOW A BAND OF ENHANCED INSTABILITY /1000-1500 J/KG OF MLCAPE/ DEVELOPING DURING THE AFTERNOON MORE OR LESS ALONG THE UPPER MN RIVER VALLEY. SEEING SOME INDICATIONS IN BOTH CAMS AND DETERMINISTIC MODELS OF SOME ISO/SCT TYPE CONVECTION DEVELOPING SUNDAY AFTERNOON WITHIN THIS INSTABILITY AXIS...SO HAVE LEFT SOME 20 POPS IN THERE TO ACCOUNT FOR THAT...THOUGH EXPECT IT TO BE MAINLY DRY FOR SUNDAY. FOR THE FOG THREAT TONIGHT...THINK NAM IS OVERDONE WITH THE AMOUNT OF LOW LEVEL MOISTURE IT HAS AND IS THEREFORE OVERDOING ITS FOG POTENTIAL IN WRN WI. LIKE THE IDEA OF THE RAP/GFS WITH FOG THREAT BEING PRIMARILY UP NE MN INTO NW WI. FINALLY...DID BOOST HIGHS FOR SUNDAY A FEW DEGREES ACROSS THE AREA. NAM/GFS SHOW US MIXING UP TO 800 MB...AND MIXING DOWN FROM THIS LEVEL YIELDED POTENTIAL HIGHS IN THE MID/UPPER 80S...SO MIXED THAT IN WITH OUR GOING FORECAST TO GET MOST FOLKS UP INTO THE LOW/MID 80S FOR HIGHS SUNDAY. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 359 PM CDT SAT JUN 20 2015 CONCERNS IN THE LONG TERM ARE CENTERED AROUND SEVERE WEATHER CHANCES SUNDAY NIGHT AND MONDAY AS A DEEPENING SHORT WAVE PASSES ACROSS THE FA. THIS RESULTS IN STRENGTHENING SURFACE LOW PRESSURE OVER SOUTH DAKOTA SUNDAY NIGHT ALONG WITH A WARM FRONT LIFTING NORTHEAST INTO SOUTHERN MINNESOTA AND WISCONSIN LATE IN THE NIGHT. MODEL CONSENSUS INDICATES THE NOSE OF THE LOW LEVEL JET EXCEEDS 50 KNOTS INTO SOUTH CENTRAL AND SOUTHEAST MINNESOTA MONDAY MORNING ACCOMPANIED BY PW VALUES IN EXCESS OF 2 INCHES...ONCE AGAIN ABOVE THE TOP OF KMPX SOUNDING CLIMATOLOGY. THE LOW AND WARM FRONT SHOULD PUSH RATHER QUICKLY ACROSS THE FA DURING THE DAY ON MONDAY WITH SEVERE WEATHER CHANCES LESSENING IN THE AFTERNOON. THE SETUP SUNDAY NIGHT AND EARLY MONDAY SHOULD YIELD A COMPLEX OF STORMS PUSHING ACROSS SOUTHERN MN AND ADJOINING AREAS OF WI. PROFILE DATA INDICATES A STRONG WARM LAYER DEVELOPING IN THE LOW LEVELS DURING THE NIGHT WITH VIRTUALLY ALL OF THE CAPE (1500 J/KG) BEING ABOVE 850 MB. HENCE...DUE TO THE STRONGLY VEERING WIND PROFILE CONFIDENCE FOR HAIL IS HIGHER THAN WIND EARLY ON IN THIS EVENT. IN ADDITION...THE 925-850MB FN VECTOR DIVERGENCE ALSO RUNS ALONG THE I-90 CORRIDOR LEADING TO HIGHER CONFIDENCE ON WHERE THE HEAVIEST RAIN MAY FALL. AT THIS POINT...CAMS THAT REACH OUT TO MONDAY MORNING ARE SHOWING A COMPLEX OF STORMS PASSING ALONG THE MN/IA BORDER. THEREFORE...COLLABORATION TODAY WAS TO BREAK POPS INTO 3 HOUR GROUPS AND DRIVE THUNDERSTORMS ACROSS OUR FAR SOUTHERN FA LATE SUNDAY NIGHT AND EARLY MONDAY. IN THE WAKE OF THIS FEATURE...MONDAY NIGHT AND TUESDAY ARE DRY AS HIGH PRESSURE SLIDES BY. A SURFACE FRONTAL BOUNDARY WILL BE STRENGTHENING ACROSS THE CENTRAL PLAINS INTO THE LOWER GREAT LAKES FOR WEDNESDAY AND THURSDAY WITH THE HIGHEST CHANCES FOR PRECIPITATION TO OUR SOUTH WITH SMALL CHANCES EXTENDING ACROSS PORTIONS OF OUR FA. CONFIDENCE IS NOT HIGH ON THE PRECIPITATION CHANCES FOR THESE PERIODS. THE STRONG WESTERLY UPPER AIR PATTERN IS STILL FORECAST TO BUCKLE LATE IN THE WEEK AND WEEKEND AS RIDGING DEVELOPS ACROSS IN THE WESTERN CONUS WITH A PRETTY DEEP TROUGH IN THE EAST. THIS TRANSITION PERIOD (FRIDAY AND SATURDAY) WILL OFFER THE NEXT PERIOD OF HIGH CHANCE POPS ACROSS THE FA. TEMPERATURES WILL BE CLOSE TO SEASONAL VALUES THROUGH THURSDAY WITH A SMALL DOWNWARD TREND ON HIGH TEMPERATURES THROUGH THE UPCOMING WEEKEND. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1150 PM CDT SAT JUN 20 2015 MAIN AVIATION CONCERN IS FOG POTENTIAL AT KRNH/KEAU OVERNIGHT AS LIGHT WINDS AND MOSTLY CLEAR SKIES SHOULD LEAD TO FOG FORMATION. HOW DENSE THE FOG BECOMES IS THE MAIN ISSUE. WILL CONTINUE WITH IFR CONDS AT BOTH KEAU/KRNH THRU 13Z /STARTING ARND 8Z/. OTHERWISE...VFR CONDS WILL PREVAIL ACROSS THE REST OF MPX CWA WITH WINDS GENERALLY FROM THE WNW TONIGHT/SUNDAY...BECOMING SW SUNDAY EVENING. ANY PRECIPITATION SHOULD HOLD OFF UNTIL AFT 6Z MONDAY. KMSP... HIGH CONFIDENCE IN VFR CONDS THRU MOST OF THE TAF PERIOD...WITH CONDS POSSIBLY LOWERING TO MVFR BY THE END OF THE TAF PERIOD WITH TSRA/SHRA. DUE TO UNCERTAINTIES ON TIMING OF THE NEXT SYSTEM MOVING ACROSS THE NORTHERN PLAINS/UPPER MIDWEST...WILL KEEP VFR AT THIS TIME WITH CIGS LOWERING TO 9K. WINDS WILL REMAIN FROM THE WNW TONIGHT/SUNDAY...BECOMING SW/S SUNDAY EVENING. /OUTLOOK FOR KMSP/ MON...VFR. CHC MVFR WITH AM TSRA/SHRA. WIND S 5-10 KT BCMG NW 10KTS. TUE...VFR. WINDS NW TO W AT 5 KT. WED...VFR. CHC OF TSRA. WINDS E-SE 5 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...MPG LONG TERM...RAH AVIATION...JLT
AREA FORECAST DISCUSSION
NWS JACKSON MS
451 AM CDT SUN JUN 21 2015 .DISCUSSION... TODAY THROUGH MONDAY NIGHT... THE SUBTROPICAL RIDGE WILL GRADUALLY BUILD OVER THE ARKLAMISS AS WE GO THROUGH EARLY THIS WEEK...EVENTUALLY PEAKING OVER THE AREA LATER IN THE WEEK. IN THE NEAR TERM...A WEAKNESS IN THE RIDGE JUST WEST OF THE ARKLAMISS WILL HELP TO DRAW DEEP LAYER MOISTURE NORTHWARD. THIS HIGH PRECIPITABLE WATER AIR WILL CIRCULATE THROUGH THE RIDGE AND HELP TO INCREASE DIURNAL CONVECTIVE POTENTIAL IN SPITE OF MOSTLY SUBSIDENT ANTI-CYCLONIC FLOW. THE MAIN FOCUS FOR CONVECTIVE POTENTIAL LATE THIS AFTN/EVNG SHOULD BE OVER THE PINE BELT WHERE COASTAL CONVERGENCE AND LESS RIDGE INFLUENCE WILL BE FELT...A ALONG/W OF THE MS RIVER IN CLOSER PROXIMITY TO RIDGE WEAKNESS. THE SPC SSEO REFLECTS THIS GENERAL PATTERN AS DOES THE HRRR...ALTHOUGH THE HRRR SEEMS A BIT TOO GENEROUS WITH COVERAGE. IN ANY CASE HAVE BOOSTED POPS UP ABOVE MOST GUIDANCE VALUES IN THOSE AREAS...BUT THEY ARE STILL ON THE LOW SIDE. THERE SHOULD BE SOME POTENTIAL FOR STRONG/SVR MICROBURSTS ASSUMING THAT STORMS DEVELOP GIVEN STEEPER LAPSE RATES (VERTICAL TOTALS ~27-28, 0-3KM LAPSE RATES > 8.5 DEG C/KM). WILL HOLD OFF ON ANY MENTION OF SEVERE POTENTIAL IN THE HAZARD PRODUCTS GIVEN VERY LIMITED COVERAGE. AS HAS BEEN ADVERTISED...HEAT STRESS WILL BECOME A BIGGER CONCERN GOING INTO MONDAY DUE TO THE INTENSIFYING RIDGE. FORECAST HEAT INDICES ARE EXPECTED TO APPROACH 105 BY MONDAY AFTN...SO WILL GO AHEAD AND FORMALLY INTRODUCE A LIMITED THREAT FOR DANGEROUS HEAT STRESS IN THE HWO/GRAPHICS. OTHERWISE...MORE ISOLATED/SCT DIURNAL TSTM ACTIVITY MAINLY OVER SOUTHERN PORTIONS OF THE ARKLAMISS CAN BE EXPECTED. MODELS SUGGEST THERE COULD BE GREATER INSTABILITY AND POTENTIAL FOR STRONG/SVR MICROBURST ACTIVITY WITH STORMS LIKELY NOT DISSIPATING UNTIL AFTER SUNSET IN HOT/HUMID AIRMASS. /EC/ TUESDAY THROUGH SATURDAY... THE SUBTROPICAL RIDGE WILL OVERALL REMAIN INTACT OVER THE CWA THROUGH MOST OF THE WORK WEEK. HOT AND HUMID CONDITIONS WILL PERSIST DURING THIS TIME AS HIGHS PEAK IN THE MID 90S AND DEW POINTS IN THE LOW TO MID 70S. THIS MAY RESULT IN DANGEROUS HEAT INDICES DURING SEVERAL AFTERNOONS NEXT WEEK...PARTICULARLY TUESDAY AND WEDNESDAY AFTERNOON....AS THEY`RE PROGGED TO RANGE BETWEEN 100-105F. THUS...I`LL MAINTAIN THE "LIMITED" POTENTIAL FOR AFTERNOON HEAT INDICES REACHING TO NEAR 105F IN THE HWO FOR BOTH TUESDAY AND WEDNESDAY AFTERNOONS. OF COURSE... THIS COULD BE EXPANDED FOR LATER IN THE WEEK IF NEEDED. WITH ALL THAT SAID...THIS LEVEL OF HEAT WILL BE MONITORED DURING THE PERIOD AS HEAT ADVISORIES MAY BE NEEDED FOR PORTIONS OF THE AREA. RAIN CHANCES WILL BE CONFINED TO THE AFTERNOON AND EARLY EVENING HOURS. MODELS CONTINUE TO SUGGEST THAT EASTERLY FLOW SOUTH OF THE AFOREMENTIONED RIDGE COULD INTERACT WITH CONVECTION ALONG THE SEABREEZE TUESDAY. THIS COULD POTENTIALLY HELP TO INCREASE THE COVERAGE OF CONVECTION OVER THE SOUTHERN AND CENTRAL PORTIONS OF THE FORECAST AREA DURING THIS TIME. HENCE...THE BEST RAIN CHANCES DURING THE PERIOD CURRENTLY LOOK TO FALL ON TUESDAY AFTERNOON. AS FRIDAY AND SATURDAY ROLL AROUND...MODELS ARE CURRENTLY IN AGREEMENT THAT THE RIDGE WILL BEGIN TO RETROGRADE BACK WEST OF THE REGION. THIS WILL ALLOW A TROUGH TO BEGIN DIGGING SOUTH AND INTO THE DEEP SOUTH DURING NEXT WEEKEND. /19/ && .AVIATION...STRATUS AND PATCHY AREAS OF FOG WILL BE LESS PREVALENT THIS MORNING THAN IN RECENT DAYS GIVEN LIGHTER AND MORE WESTERLY FLOW AS THE RIDGE BUILDS OVER THE REGION. EXPECT VFR CONDITIONS TO PREVAIL FOR THE MOST PART TODAY THROUGH TONIGHT WITH LIMITED TSRA COVERAGE MAINLY ALONG AND SOUTH OF THE JAN/HKS/MEI CORRIDOR. /EC/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 94 75 95 74 / 18 18 15 15 MERIDIAN 94 72 95 72 / 26 26 15 15 VICKSBURG 93 74 95 74 / 24 24 12 11 HATTIESBURG 94 75 95 75 / 26 26 27 23 NATCHEZ 92 74 93 75 / 26 26 22 20 GREENVILLE 93 75 96 75 / 12 12 11 6 GREENWOOD 94 74 96 75 / 10 10 14 9 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ EC/19/
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
243 AM CDT Sun Jun 21 2015 .SHORT TERM...(Today and Tonight) It was a typical June night over extreme southeast Kansas and the Missouri Ozarks. Temperatures had cooled into the lower 70s, under mostly clear skies and light southwesterly breezes. A complex of thunderstorms were ongoing across northeast Missouri. This feature threw an outflow boundary to the southwest, which was moving into central Missouri. Convection was not developing along the outflow, due to dry air in the mid levels, and strong convective inhibition present within the Ozarks lower trop. The hi-res ARW and NMM suggest that convection will eventually fire along this boundary by 9-12z this morning. The HRRR along with several other models keeps the Ozarks dry today. Given the 00z RAOB from last night, we will keep the forecast dry through today, for the exception of some low end pops in central Missouri. Look for temperatures to warm into the upper 80s and lower 90s today. .LONG TERM...(Monday through Saturday) The summertime high attempts to build over the nation`s midsection Monday through Thursday. This will bring sunshine, humidity, and hot temperatures. Look for temperatures to range from the upper 80s to the lower 90s on an afternoon basis through Thursday. The periphery of the summertime high will act as a storm track for a series of shortwave troughs. This storm track will reside across northern Missouri or southern Iowa, so we will need to watch any convection that may attempt to sneak into central Missouri. Right now we`re going to keep precipitation chances in central Missouri very conservative through Thursday. All other locations south of Highway 54 can expect hot and dry weather through Thursday. By Thursday night or Friday, the summer high re-positions across the Mountain West, forcing northwest flow and a cold front into southern Missouri. This will not only cool temperatures off, but also bring our next widespread chance for showers and thunderstorms. Both the GFS and the ECMWF suggests precipitation chances to continue through the upcoming weekend. It`s a little ways out to get too specific about details, but we`ll have some chances going in the forecast. && .AVIATION...(For the 06Z TAFS through 06Z Sunday Night) Issued at 1118 PM CDT SAT JUN 20 2015 Low level wind shear will be the main concern for the terminals through tonight, as a fairly strong low level jet overspreads the region. Southwest winds will then become gusty by mid morning on Sunday, continuing through sunset. && .SGF WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ SHORT TERM...Cramer LONG TERM...Cramer AVIATION...Boxell
AREA FORECAST DISCUSSION
NWS BILLINGS MT
256 AM MDT SUN JUN 21 2015 .SHORT TERM...VALID FOR TDY AND MON... QUIET WEATHER ACROSS OUR CWA EARLY THIS MORNING AS WE REMAIN UNDER THE INFLUENCE OF FLAT UPPER LEVEL RIDGING...WITH CONVECTION AT NOSE OF LOW LEVEL JET STILL DEVELOPING TO OUR SOUTHEAST FROM NORTHEAST WY INTO SOUTHWEST SD. WATER VAPOR IMAGERY SHOWS A COUPLE FEATURES OF INTEREST...ONE SHORTWAVE MOVING INTO OR AND ANOTHER IN SOUTHERN BC. THESE WAVES WILL PARTIALLY PHASE TOGETHER AND BRING US A GOOD CHANCE OF SHOWERS AND TSTMS LATER TODAY THROUGH TONIGHT. POTENTIAL EXISTS FOR SEVERE STORMS IN OUR EAST THIS AFTERNOON MAINLY ALONG AND EAST OF A MILES CITY TO ALZADA LINE. MOIST ADVECTION ALREADY OCCURRING PER SOUTHEASTERLY FLOW UP THE HIGH PLAINS WITH LATEST ANALYSIS SHOWING PWATS TO AN INCH IN SOUTHEAST MT. WEAK MID LEVEL SHORTWAVE AND SFC WARM FRONT WILL PUSH ACROSS OUR CWA THIS MORNING. THOUGH THE BOUNDARY LAYER WILL BECOME WELL- MIXED AND DRIER ACROSS OUR WEST AND CENTRAL PARTS...MOISTURE AND INSTABILITY WILL BECOME DEEPER EAST OF SFC TROF. LATEST HRRR RUNS SEEM VERY REASONABLE IN DEVELOPING CONVECTION IN OUR FAR EAST BY AROUND 19Z AS CAPES BUILD TO 1500+ J/KG. INSTABILITY AND PLENTIFUL EFFECTIVE BULK SHEAR ARE SUGGESTIVE OF SEVERE STORMS IN THIS AREA THROUGH AROUND 00Z...BY WHICH THE PRE-FRONTAL SFC TROF SHOULD SHIFT INTO THE WESTERN DAKOTAS. LARGE HAIL AND DAMAGING WINDS ARE MAIN THREATS BUT CANNOT RULE OUT A TORNADO EITHER ESPECIALLY IF SFC DEW PTS CLIMB TO NEAR 60F. AGAIN THIS POTENTIAL IS IN OUR FAR EAST AND STORMS MAY INITIATE AS EARLY AS 19Z. OTHER AREA OF CONCERN IS OUR WEST AS SHOWERS AND TSTMS EXPECTED TO DEVELOP THIS AFTERNOON AND EVENING AS LARGE SCALE ASCENT INCREASES IN COMBINATION W/ A COLD FRONTAL PASSAGE. MAIN RISK IN OUR WEST WILL BE WIND PER FRONTAL PUSH AND DEEPLY MIXED PRE- FRONTAL BOUNDARY LAYER...IE A COMBINATION OF CONVECTIVE AND FRONTAL WINDS...THOUGH CANNOT RULE OUT SMALL HAIL AS WELL. FRONT IS EXPECTED TO IMPACT LVM-3HT BY LATE AFTERNOON THEN BIL/SHR DURING THE EVENING. WILL CONTINUE TO HIGHLIGHT ALL OF THESE POTENTIAL IMPACTS IN HWO AND GRAPHIC. TEMPS TODAY WILL CLIMB INTO THE 80S IN PRE-FRONTAL REGIME...WITH HIGHS BACK DOWN TO THE MID TO UPPER 70S MONDAY. COULD SEE SOME AFTERNOON/EVENING SHOWERS AND WEAKER STORMS IN OUR WEST TOMORROW. ACTIVITY MAY SPREAD TO OUR SOUTHEAST BY LATE MONDAY NIGHT AS NEXT AREA OF PV COMES OFF THE PACIFIC AND SOUTHEASTERLY LOW LEVEL JET BEGINS TO ADVECT MOISTURE BACK TO SOUTHEAST MT. NO SEVERE WX ANTICIPATED MONDAY OR MONDAY NIGHT. JKL .LONG TERM...VALID FOR TUE...WED...THU...FRI...SAT... EXTENDED FORECAST PERIOD KEEPS AN UNSETTLED BUT WARM ZONAL FLOW ACROSS THE AREA TUESDAY INTO FRIDAY WHICH WILL MAINTAIN THE CHANCES FOR THUNDERSTORM ACTIVITY A FEW DAYS LATER THAN PREVIOUSLY INDICATED. MODELS SHOW EPISODES OF EASTERLY FLOW AT THE LOW LEVELS DURING THIS PERIOD WHICH WILL PROVIDE HIGHER DEWPOINTS SUPPORTING THE THUNDERSTORMS. TIMING AND STRENGTH OF SHORTWAVES DURING THIS PERIOD IS LESS CERTAIN BUT HAVE THUNDERSTORMS MENTIONED EACH DAY AND WILL HAVE TO WATCH CAPE VALUES TO SEE IF SEVERE WEATHER WILL BE POSSIBLE. TEMPERATURES WILL BE SLIGHTLY ABOVE NORMAL DURING THE PERIOD IN THE MID 80S FOR MOST PLACES. MODELS SHOWING THE RIDGE BEGINNING TO ASSERT ITS INFLUENCE FOR SATURDAY AND SUNDAY OVER WESTERN MONTANA WHICH LOOKS TO DISRUPT THE LOW LEVEL EASTERLY FLOW FOR MOST OF THE AREA. PREVIOUSLY ADVERTISED WARMUP LOOKS A BIT SLOWER BUT STILL SHOULD BEGIN TO APPROACH 90 BY SUNDAY...POSSIBLY SATURDAY FOR A FEW AREAS. WILL SEE A DRYING TREND DURING THE WEEKEND. BORSUM && .AVIATION... MOSTLY CLEAR CONDITIONS TO START THE DAY WITH A FEW MID LEVEL CLOUDS. TWO AREAS OF THUNDERSTORM ACTIVITY ARE EXPECTED DURING THE AFTERNOON HOURS. DURING THE EARLY AFTERNOON SEVERE THUNDERSTORMS ARE EXPECTED ALONG AND EAST OF A KMLS TO K4BQ LINE WITH STORMS CAPABLE OF PRODUCING LARGE HAIL ALONG WITH VERY STRONG WINDS. A SECOND AREA OF THUNDERSTORMS WILL MOVE INTO THE WESTERN HALF OF THE FORECAST AREA DURING THE MID AFTERNOON HOURS WITH STORMS NOT AS INTENSE BUT ASSOCIATED WITH A COLD FRONT WHICH WILL BRING A THREAT OF STRONG WIND GUSTS. THESE STORMS WILL IMPACT KLVM AROUND 21Z AND REACH KBIL AROUND 23Z. BORSUM && .PRELIMINARY POINT TEMP/POPS... TDY MON TUE WED THU FRI SAT ------------------------------------------------------- BIL 086 055/078 056/081 057/083 060/090 063/088 062/086 2/T 41/B 23/T 32/T 21/B 11/U 11/U LVM 084 048/077 050/081 050/084 053/090 055/089 054/087 2/T 42/T 33/T 32/T 21/B 11/U 11/U HDN 088 054/080 055/083 058/085 060/092 062/089 061/087 1/B 31/B 33/T 33/T 21/B 11/B 11/U MLS 087 057/078 057/081 057/082 059/087 060/086 060/083 2/T 51/B 33/T 33/T 22/T 22/T 21/U 4BQ 086 055/077 056/079 056/081 059/087 061/087 059/083 2/T 31/B 43/T 43/T 32/T 22/T 21/U BHK 083 054/075 054/078 055/078 056/082 059/082 056/079 4/T 52/T 23/T 44/T 33/T 33/T 32/T SHR 086 052/076 052/079 053/080 054/087 057/086 056/082 1/B 20/B 23/T 32/T 22/T 22/T 21/B && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1258 AM CDT SUN JUN 21 2015 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 324 PM CDT SAT JUN 20 2015 UPPER AIR AND SATELLITE DATA SHOW THE AREA SITTING UNDER GENERALLY ZONAL FLOW...AN AREA OF HIGH PRESSURE IS SETTLED OVER THE SWRN COAST...WHILE LOW PRESSURE SLIDES EAST ACROSS THE MIDWEST. ANOTHER SHORTWAVE DISTURBANCE IS MOVING ACROSS NRN MN INTO THE GREAT LAKES REGION...WITH IT BEING RESPONSIBLE FOR THE FRONTAL BOUNDARY ACROSS THE AREA. AS EXPECTED...THE FRONT HAS GRADUALLY SAGGED SOUTH THROUGH THE DAY...AND CURRENTLY SITS ACROSS THE FAR SERN CORNER OF THE CWA. STARTING AROUND MID MORNING...HAD A FEW ISOLATED SHOWERS AND RUMBLES OF THUNDER DEVELOP ALONG THE FRONT...ENDED UP THROWING SOME SLIGHT POPS IN THE FORECAST. SINCE THEN...HASNT BEEN ANY INCREASE IN ACTIVITY...WITH THE SPC MESO PAGE SHOWING CAPPING IN PLACE WITH 700MB TEMPS AROUND 14C. HASNT BEEN ANY SURPRISES WITH TEMPERATURES OR DPTS...WITH 3 PM OBS RANGING FROM THE LOWER 80S IN THE FAR NORTH TO MID 90S IN THE SOUTHEAST. HEAT INDEX VALUES HAVE REACH NEAR 100 IN THE FAR SOUTHEAST. THE RAP AND HRRR CONTINUE TO SHOW THAT LATE THIS AFTERNOON /BANKING ON A WEAKENING CAP/ THAT THUNDERSTORMS WILL DEVELOP ALONG THE FRONT ACROSS THE EXTREME SE CORNER OF THE CWA...AND WILL CONTINUE TO CARRY SOME SLIGHT POPS IN THAT AREA...OTHER MODELS SHOW NOTHING DEVELOPING. OUTSIDE OF THAT...THE EVENING HOURS ARE EXPECTED TO BE DRY. LATER TONIGHT AND INTO A PORTION OF THE DAY TOMORROW...CONTINUED TO CARRY THE POPS ACROSS ROUGHLY THE NRN HALF OF THE CWA...WITH MODELS SHOWING ANOTHER WEAK UPPER LEVEL SHORTWAVE DISTURBANCE MOVING OUT OF THE ROCKIES. LITTLE UNCERTAINTY WITH THE TIMING...AND OVERALL COVERAGE...WITH THE LATEST HRRR COMING IN WITH MORE ACTIVITY THAN BASICALLY ANY OTHER MODEL. WILL HAVE TO SEE HOW UPCOMING MODEL RUN TRENDS AND MONITOR ACTIVITY TO THE W/NW THIS EVENING...AND ADJUST AS NECESSARY. AT THIS POINT...KEPT THOSE POPS CONFINED TO AFTER 06Z...CONTINUING INTO THE FIRST HALF OF THE DAY TOMORROW...WITH A DRY AFTERNOON. AT THE SFC...EXPECTING HIGHER PRESSURE TO SETTLE IN ACROSS THE AREA TONIGHT...RESULTING IN LIGHTER WINDS...BUT BECOMING MORE E/SERLY WITH TIME. LOW PRESSURE BECOMES ORGANIZED TOMORROW OVER THE HIGH PLAINS...WITH THE POTENTIAL FOR A WARM FRONTAL BOUNDARY TO SET UP NEAR THE STATE LINE. MODELS SHOW THAT SERLY COMPONENT TO THE WINDS REMAINING MAINLY OVER NEB...WITH MORE SRLY WINDS OVER NC KS. AS FAR AS TEMPERATURES GO...CURRENT FORECAST CALLS FOR CONDITIONS SIMILAR TO TODAY...MID 80S IN THE NORTH...MID/UPPER 90S IN THE S/SW. LOOKING AT HEAT INDEX VALUES AROUND 100 AGAIN POSSIBLE ROUGHLY NEAR/SOUTH OF THE STATE LINE. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 324 PM CDT SAT JUN 20 2015 GUIDANCE SUGGESTS UPPER TROPOSPHERIC RIDGING WILL BE NOTED OVER THE WESTERN HALF OF THE CONUS TO START THE LONG-TERM FORECAST PERIOD AT 00 MONDAY. THIS RIDGE IS EXPECTED TO WEAKEN SOMEWHAT THROUGH WEDNESDAY...WITH A STRENGTHENING RIDGE ACROSS THE WESTERN CONUS EXPECTED THURSDAY ONWARD. AS A RESULT...QUASI-ZONAL TO AT TIME NORTHWESTERLY UPPER TROPOSPHERIC FLOW IS EXPECTED OVER OUR AREA MONDAY THROUGH WEDNESDAY...WITH INCREASINGLY NORTHWESTERLY FLOW THURSDAY ONWARD. STARTING WITH SUNDAY NIGHT INTO EARLY MONDAY MORNING...GUIDANCE CONTINUES SHIFTING ANY APPRECIABLE CHANCE AT PRECIPITATION TO THE NORTH/NORTHEAST OF OUR AREA...MORE ALONG THE PRIMARY AXIS OF ENHANCED UPPER TROPOSPHERIC FLOW. ALTHOUGH THE OPERATIONAL GFS DOES SUGGEST A VERY ISOLATED AREA ACROSS OUR FAR NORTHWESTERN CWA COULD SEE PRECIPITATION EARLY MONDAY MORNING...THIS OUTPUT IS THE OUTLIER WHEN COMPARED TO THE NAM AND EC WHICH BOTH KEEP ANY PRECIPITATION WELL TO OUR NORTH/NORTHEAST. GIVEN THIS...OPTED TO GO AHEAD WITH DRY CONDITIONS SUNDAY NIGHT INTO EARLY MONDAY MORNING. DRY CONDITIONS ALSO REMAIN IN THE FORECAST DURING THE DAY MONDAY AND MONDAY EVENING AS AN OVERALL LACK IN OMEGA PERSISTS ACROSS THE REGION. STARTING EARLY TUESDAY MORNING AND CONTINUING INTO THE DAY TUESDAY...A SUBTLE PERTURBATION ADVANCING EAST/NORTHEAST FROM THE MID ROCKIES...MOST EVIDENT NEAR 700MB PER MODEL GUIDANCE...COULD BRING OUR NEXT CHANCE FOR PRECIPITATION...ESPECIALLY ACROSS CENTRAL AND NORTHERN PORTIONS OF THE CWA. THIS IS A SOLUTION SUPPORTED BY QPF FIELDS FROM THE NAM AND OPERATIONAL GFS...AND TO A LESSER EXTENT THE EC. GIVEN THIS...OPTED TO GO AHEAD WITH 20-30% POPS ACROSS CENTRAL AND NORTHERN PORTIONS OF THE CWA EARLY TUESDAY MORNING THROUGH THE DAY TUESDAY. TUESDAY NIGHT AND BEYOND...AS PREVIOUSLY MENTIONED...INCREASING NORTHWESTERLY UPPER TROPOSPHERIC FLOW SHOULD DEVELOP OVER OUR AREA A THE WESTERN CONUS RIDGE STRENGTHENS...THUS INCREASING THE CHANCES FOR MULTIPLE SMALL-SCALE PERTURBATION TO CLEAR THE REGION. AS MENTIONED BY THE PREVIOUS SHIFT...CONFIDENCE WITH RESPECT TO THE REALIZATION OF PRECIPITATION ON ANY GIVEN DAY DURING THIS TIME PERIOD REMAINS LOW...BUT ITS HARD TO JUSTIFY A DRY FORECAST BASED ON MODEL GUIDANCE AND AS A RESULT...WENT AHEAD AND MAINTAINED POPS...GENERALLY IN THE 20-40% RANGE...ACROSS MUCH OF THE AREA TUESDAY NIGHT THROUGH SATURDAY. GUIDANCE SUGGESTS RESPECTABLE VALUES OF LOWER TROPOSPHERIC MOISTURE...WORKING IN CONCERT WITH VARYING LAPSE RATES WITH THE PASSAGE OF UPPER TROPOSPHERIC PERTURBATIONS...WILL PRESENT POTENTIAL ENERGY VALUES GENERALLY IN THE 1000-3000J/KG RANGE EACH DAY DURING THE LONG-TERM FORECAST PERIOD. DEEP-LAYER BULK SHEAR OF ~30KTS WILL ALSO BE POSSIBLE AS THE ENHANCED UPPER TROPOSPHERIC FLOW ESTABLISHES ITSELF OVER THE REGION. THAT SAID...FORECAST PROXIMITY SOUNDINGS FROM THE ACROSS THE CWA...PER THE NAM AND OPERATIONAL GFS...SUGGEST A HEALTHY LOWER TROPOSPHERIC CAPPING INVERSION WILL BE PRESENT EACH DAY AND WITH OMEGA REMAINING ON THE QUESTIONABLE SIDE...ITS HARD TO SAY THAT ANY ONE DAY HAS A GREATER CHANCE OF SEVERE WEATHER OVER THE NEXT. OBVIOUSLY...ANY DAY THAT CAN REALIZE CONVECTIVE INITIALIZATION WILL HAVE AT LEAST A CHANCE OF STRONG TO SEVERE THUNDERSTORM ACTIVITY...BUT CONFIDENCE IS NOT HIGH ENOUGH TO DEFINITIVELY MENTION SUCH CONDITIONS IN THE HWO. GIVEN THIS...FOR THE HWO...WILL SIMPLY STATE THAT SEVERE CONVECTION IS NOT OUT OF THE QUESTION DURING THE LONG-TERM FORECAST PERIOD...AND THE FORECAST WILL NEED TO BE MONITORED FOR THE POSSIBILITY OF SEVERE WEATHER DURING THE MIDDLE TO LATE PART OF NEXT WEEK. PRE-FRONTAL WARMING AHEAD OF A BOUNDARY-LAYER BAROCLINIC ZONE COULD PRESENT A VERY WARM DAY ON MONDAY..WITH GUIDANCE CURRENTLY SUGGESTING AFTERNOON TEMPERATURE READINGS COULD SPIKE TO AROUND 100 DEGREES MONDAY AFTERNOON ACROSS OUR SOUTHERN ZONES...AND MORE INTO THE 90S FARTHER NORTH ACROSS THE AREA. ITS IMPORTANT TO NOTE THAT FRONTAL POSITION WILL PLAY A CRUCIAL ROLE IN TEMPERATURE READINGS ON MONDAY AND THIS WILL NEED TO BE CLOSELY MONITORED. THE INFILTRATION OF A COOLER BOUNDARY-LAYER AIR MASS POST-FROPA SHOULD THEN ALLOW FOR HIGHS IN THE 80S AND LOW 90S TO FINISH THE FORECAST PERIOD. FINALLY...RESULTANT HEAT INDEX READINGS MONDAY AFTERNOON ARE EXPECTED TO CLIMB INTO THE 100-105 RANGE ACROSS OUR KANSAS COUNTIES AND AS A RESULT...WILL CONTINUE MENTIONING THIS IN THE HWO. && .AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1247 AM CDT SUN JUN 21 2015 OUR EAST NORTHEAST WIND WILL GRADUALLY BECOME MORE EASTERLY AS WE NEAR DAWN AND SHOULD BECOME MORE SOUTHEAST BY AFTERNOON. OVERALL THE WIND WILL BE LIGHT. LOW LEVEL WIND SHEAR MAY BE A PROBLEM LATE THIS EVENING ESPECIALLY FROM GRAND ISLAND EASTWARD AS THE LOW LEVEL JET INCREASES AND PUSHES BACK NORTH. THERE WILL BE A FAIR AMOUNT OF CLOUDS AROUND TODAY...BUT MOST GUIDANCE INDICATES CEILINGS WILL REMAIN VFR WITH CLOUD BASES AT OR ABOVE 4000 FT AGL. CAN NOT RULE OUT THE CHANCE OF A THUNDERSTORM PRIMARILY THIS MORNING...BUT TOO LOW OF A CHANCE TO INCLUDE IT IN THE TAF AT THIS POINT IN TIME. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...ADP LONG TERM...BRYANT AVIATION...WESELY
AREA FORECAST DISCUSSION
NWS TULSA OK
1152 PM CDT SAT JUN 20 2015 .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. FOR THE 6Z TAFS... VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES THROUGHOUT THE 24 HOUR FORECAST PERIOD. SOUTHWEST WINDS WILL INCREASE SUNDAY DURING THE DAY ACROSS THE REGION. && .PREV DISCUSSION... /ISSUED 941 PM CDT SAT JUN 20 2015/ DISCUSSION... FORECAST ON-TRACK. HRRR TAKES MINOR NORTHEAST TEXAS CONVECTION NEAR/INTO EXTREME SOUTHEASTERN ZONES LATE TONIGHT SUNDAY MORNING. LOW CHANCE POPS AT THIS TIME. GW && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ AVIATION...06
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
451 AM EDT SUN JUN 21 2015 .SYNOPSIS... DEEP HIGH PRESSURE WILL BUILD BACK ACROSS THE REGION TODAY AND REMAIN THROUGH THE MIDDLE OF THE WEEK. HOT TEMPERATURES WILL ALSO RETURN AS A STALLED FRONT REMAINS NORTH OF THE FORECAST AREA. BY THE END OF THE WORK WEEK...THE HOT PATTERN IS EXPECTED TO BREAK DOWN AS A TROUGH MOVES SOUTH OUT OF CANADA. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 0430 AM EDT UPDATE...CURRENT NEAR TERM FCST IS IN GOOD SHAPE. MADE MINOR TWEAKS TO HR/LY TEMPS. ADDED AFTERNOON ISOL TSTMS ACROSS THE WRN UPSTATE AND NE GA BASED ON LATEST CAM AND RAP TRENDS TOWARD LESS CCL-LFC CIN LEVELS. THE LARGE SCALE PATTERN SHIFTS BACK INTO A MORE NORMAL SUMMERTIME CONFIG TODAY. SUBTROPICAL RIDGING WILL REASSERT ITSELF ACROSS THE SE CONUS CREATING A DIFFUSE WIND PROFILE ALOFT. CROSS SECTIONS SHOW DEEP NEGATIVE OMEGA OUTSIDE THE MTNS DURING THE AFTERNOON WITH LIMITED AVAILABLE LLVL MOISTURE. YET THE OP MODELS ARE MIXED WRT TO AMOUNT OF PARCEL DESTABILIZATION. THE NAM SHOWS A POTENTIAL OF THE SUBS INVERSION BEING BROKE AND ISOL EXPLOSIVE STORMS POSSIBLE OVER THE NON/MTNS. THE NAM ALSO HOLDS ONTO SOME MEASURE OF CIN ARND THE CCL THO. THE GFS ON THE OTHER HAND HAS UNBREAKABLE SBCIN AND NO POTENTIAL FOR SIGFNT CONVECTION. WENT WITH A BLEND OF THE RAW MODELS FOR POP WHICH KEEPS LESS THAN ISOL NON/MTNS ANS ISOL/SCT MTNS. THIS AGREES WELL WITH THE SREF OUTPUT AND THE LATEST CAMS...BUT FUTURE UPDATES COULD INTRODUCE ISOL CONVEC NON/MTNS. MAX TEMPS WILL REACH A FEW DEGREES WARMER THAN YESTERDAY...LIKELY M90S EAST AND U80S MTN VALLEYS. THE BEST AFTERNOON TD MIXING WILL OCCUR ACROSS THE ERN ZONES WHICH WILL KEEP MENTION OF HI/S OUT OF THE HWO. THE OVERNIGHT WILL FEATURE A QUICK REDUCTION OF DEBRIS CLOUDS AND STEEP SFC-BASED INVERSIONS. MTN VALLEYS...MAINLY THE FRENCH BROAD AND LITTLE TN...WILL ONCE AGAIN BE SUBJECT TO FG/BR ISSUES ARND DAYBREAK...ESP WHERE PRECIP FALLS THIS EVENING. EVEN WITH GOOD RAD COOLING THE ATMOS REMAINS RATHER STAGNANT WRT MIXING RATIOS...THUS MINS WILL REMAIN A COUPLE CATS ABOVE NORMAL. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/... AS OF 245 AM EDT SUNDAY...A FLAT UPPER RIDGE WILL BUILD FROM THE SOUTHERN PLAINS TO THE SOUTHERN APPALACHIANS ON MONDAY. AN MCS ORIGINATING IN THE UPPER MIDWEST MAY PASS JUST N OF THE AREA MONDAY NIGHT. OTHERWISE...ISOLD CONVECTION SHOULD BE CONFINED IN AND NEAR THE MTNS IN LOW LEVEL WIND FIELD CONVERGENCE DURING THE DIURNALLY FAVORED AFTERNOON AND EVENING PERIODS. TEMPERATURES WILL INCREASE ONCE AGAIN UNDER THE BUILDING RIDGE WITH SOME HEAT INDEX VALUES REACHING 100 TO 105 IN THE SOUTHEAST HALF MON AFTN. STRONG UPPER HEIGHTS WILL REMAIN IN PLACE ON TUE AS THE BELT OF BETTER WESTERLIES STAYS JUST NORTH OF THE FORECAST AREA. 850 MB WINDS WILL TURN MORE WESTERLY AND A PIEDMONT SFC TROUGH SHOULD BECOME A BIT MORE PROMINENT. HOWEVER...MODEL PROFILES RETAIN QUITE A BIT OF CAPPING AND NEGATIVE AREA ALOFT SO CONVECTIVE COVERAGE WILL LIKELY BE MINIMIZED. WILL CONFINED ISOLD COVERAGE TO THE MTNS...BUT TSTMS WILL BE STRONG ANY PLACE THEY MANAGE TO FORM. MAX TEMPS WILL APPROACH 100 MAINLY ALONG/SOUTHEAST OF INTERSTATE 85. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 255 AM EDT SUNDAY...STRONG RIDGING CONTINUES ON WED BUT WITH A POSSIBLE MCS TRACK SETTING UP IN THE WNW FLOW FROM THE MIDWEST TO THE NC/VA LINE ALONG A STALLED FRONTAL ZONE. THERE APPEARS TO BE A TOUCH LESS CAPPING IN PROFILES...WHICH SHOULD PERMIT BETTER SCATTERED CONVECTIVE COVERAGE DURING THE AFTN/EVENING. WILL FEATURE A NORTH TO SOUTH GRADIENT IN POP WITH HIGH CHANCES OVER THE ELEVATED TERRAIN AND NORTH OF INTERSTATE 40 NEARER ANY POSSIBLE MCS TRACKS THROUGH WED EVENING. ANOTHER ROUND OF UPPER 90S TEMPS IS LIKELY WED AFTN ACROSS THE SE HALF...WITH WELL ABOVE CLIMO MAXES/MINS THROUGHOUT. HEIGHTS SHOULD GRADUALLY FALL THU THROUGH FRI ACROSS THE SOUTHEAST...BUT WITH THE REGION REMAINING IN THE WARM SECTOR AHEAD OF ANY COLD FRONTS APPROACHING FROM THE N OR NW. MAXES/MINS REMAIN 10 DEGREES ABOVE CLIMO THU BUT THEN SLOWLY MODERATING WHILE STAYING ABOVE NORMAL INTO THE WEEKEND. THERE REMAINS CONSIDERABLE SPREAD OVER THE DEVELOPMENT OF EASTERN TROUGHING BY NEXT WEEKEND. THE GFS SHOWS BROAD AND WEAK ERN TROUGHING WITH BETTER HEIGHT FALLS OVER THE NORTHERN PLAINS...WHILE THE ECMWF SHOWS MORE ROBUST EASTERN TROUGHING WITH A CLOSED SYSTEM OVER THE GREAT LAKES. THE GFS ENSEMBLE MEANS HAVE TRENDED MORE ECMWF LIKE RECENTLY AND THE FORECAST WILL LEAN IN THAT DIRECTION. TEMPS WILL REMAIN A CATEGORY ABOVE CLIMO THROUGH SATURDAY WITH CONVECTIVE COVERAGE PICKING UP AS A COLD FRONT APPROACHES/ARRIVES FROM THE NW. && .AVIATION /09Z SUNDAY THROUGH THURSDAY/... AT KCLT...NO FLIGHT RESTRICTIONS THRU THE PERIOD. BROAD ULVL RIDGING WILL RETURN TO THE SE CONUS AND GOOD SUBS WILL KEEP VERTICAL CLOUD DEVELOPMENT AT BAY. WINDS WILL REMAIN LIGHT THROUGH THE COLUMN WITH SFC WINDS 5-9 KTS ALIGNING S OF WEST DURING THE AFTERNOON. ELSEWHERE...ONLY RESTRICTIONS WILL BE MORNING FG/BR AT KAVL AND KHKY. SHUD BURN OFF QUICKLY AFT SUNRISE WITH GOOD SFC HEATING. DEEP HIGH PRESSURE WILL KEEP AFTERNOON CONVECTION LIMITED...MAINLY ISOL ACROSS THE NC/GA/SC MTNS WITH NO TAF MENTION NEEDED AT KAVL. RELATIVELY LIGHT WINDS WILL MAINTAIN UPVALLEY AT KAVL AND SW/LY TO W/LY ALL OTHER TERMINALS. OUTLOOK...PRECIPITATION CHANCES WILL REMAIN DIURNAL INTO THE WORK WEEK. AS A RESULT...THE GREATEST CHANCES FOR AFTERNOON SHRA/TSRA WILL BE ACROSS WESTERN NC WHERE THE LEAST SUBSIDENCE WILL RESIDE. MORNING RESTRICTIONS DUE TO FOG AND/OR STRATUS ARE POSSIBLE... PARTICULARLY WHERE HEAVY RAIN FELL THE PREVIOUS DAY. CONFIDENCE TABLE... 09-15Z 15-21Z 21-03Z 03-06Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 96% HIGH 100% HIGH 100% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .CLIMATE... RECORD MAXIMUM TEMPERATURES FOR THIS WEEK...WITH YEARS IN WHICH THE VALUES WERE LAST REACHED. MONDAY JUNE 22... AVL 94 1964 CLT 98 1956 GSP 99 2006 TUESDAY JUNE 23... AVL 93 1988 CLT 98 1988 GSP 99 1988 WEDNESDAY JUNE 24... AVL 94 1952 CLT 102 1930 GSP 100 1952 THURSDAY JUNE 25... AVL 96 1952 CLT 102 1914 GSP 101 1952 && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...SBK NEAR TERM...SBK SHORT TERM...HG LONG TERM...HG AVIATION...SBK CLIMATE...GSP
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
131 AM EDT SUN JUN 21 2015 .SYNOPSIS... HIGH PRESSURE WILL STEADILY BUILD BACK INTO THE AREA FROM SUNDAY THROUGH THE MIDDLE OF NEXT WEEK...WITH HOT TEMPERATURES RETURNING AS A STALLED FRONT REMAINS NORTH OF THE REGION. BY THE END OF THE WORK WEEK THE HOT PATTERN IS EXPECTED TO BREAK DOWN AS A TROUGH MOVES SOUTHWARD OUT OF CANADA. && .NEAR TERM /THROUGH TODAY/... 0530 UTC UPDATE...NO SIGFNT CHANGES NEEDED TO THE FCST GRIDS. SKY AND POP WERE ADJ DOWN WHILE TEMPS AND TD/S WERE WITHIN THE DIURNAL FCST CURVE MOST LOCALES. 0200 UTC UPDATE...A LINE OF SHOWERS NORTH OF KCLT POPPED-UP IN THE LAST HOUR...BUT QUICKLY DISPERSED...LEAVING THE CWA NEARLY SHOWER-FREE. REMNANTS OF THESE SHOWERS...THEMSELVES RELATED TO THE OUTER RAIN BANDS OF THE REMNANTS OF TS BILL...ARE FORECAST TO GRADUALLY PROGRESS SOUTH EASTWARD BEFORE COMPLETELY DISSIPATING. REST OF UPDATES TO BLEND IN LATEST OBS FOR SKY AND TEMPERATURES. AS OF 720 PM...MOST SHOWERS AND ALL LIGHTNING HAS LEFT THE AREA WITH A FEW LIGHT SHOWERS REMAINING...MOSTLY OVER THE MOUNTAINS OF WESTERN NORTH CAROLINA. HRRR CONTINUES THE TREND OF DECLINING PRECIP SUNDAY MORNING. UPDATED FORECAST TO CLEAR MOST PRECIPITATION AND UPDATE WINDS AND TEMPERATURE TRENDS. FOR THE OVERNIGHT...THE SURFACE TROUGH ASSOCIATED WITH THE REMNANTS OF BILL WILL MOVE SOUTH OF THE AREA WITH WEAK HIGH PRESSURE BUILDING OVER THE AREA FROM THE WEST BY EARLY SUNDAY. LOOKS LIKE CONVECTIVE CHANCES ON SUNDAY WILL BE LIMITED BY OVERALL WEAK SUBSIDENCE AND LOW LEVEL CIN TO OVERCOME. HENCE...POPS WILL BE LIMITED TO ISOLATED IN NATURE OVER THE HIGH TERRAIN WHERE CIN MAY BE OVERCOME WITH AFTERNOON HEATING. WITH DOWNSLOPE FLOW...TEMPS SHOULD HAVE NO TROUBLE WARMING WELL INTO THE 90S EAST OF THE MOUNTAINS...WITH 80S MOUNTAIN VALLEYS. && .SHORT TERM /TONIGHT THROUGH TUESDAY/... AS OF 200 PM EDT SATURDAY...THE SHORT RANGE FCST PERIOD INITIALIZES SUNDAY EVENING AMIDST BUILDING HEIGHTS ALOFT OVER THE DEEP SOUTH THANKS TO STRENGTHENING UPPER ANTICYCLONE. THE SURFACE PATTERN FEATURES AN ELONGATED/CLOSED LOW PRESSURE SYSTEM SLIDING ACROSS THE NORTHEAST CONUS...WHILE A TRAILING COLD FRONT STRETCHES ALONG THE OHIO VALLEY REGION NORTHWARD. CLOSER TO HOME...A TROF IN PLACE ACROSS THE ATLANTIC SEABOARD WILL WEAKEN INTO THE EVENING AS THE PARENT LOW PRESSURE SYSTEM MOVES AWAY. GUIDANCE SUGGESTS THAT THE AFORE MENTIONED FRONT COULD STALL JUST NORTH OF THE FORECAST AREA SUNDAY NIGHT...WITH THE NAM ACTUALLY PROVIDING HINTS OF AN ONGOING FRONTAL MCS MAKING A RUN AT THE NC MOUNTAINS. WITH UPPER HEIGHTS BEING LOWEST AND ABUNDANT INSTABILITY BEING PRESENT ACROSS THESE ZONES...CANNOT RULE OUT SUCH. EXPECTING ANY OF THIS ACTIVITY TO STRUGGLE AS IT SLIDES DEEPER INTO THE SUBSIDENCE LAYER BY EARLY MORNING MONDAY...IF IT SURVIVES A TRIP ACROSS THE MTNS IN THE FIRST PLACE. POPS WILL INITIALIZE AT SLIGHT CHANCE LEVELS OVER THE BLUE RIDGE BEFORE TAPERING INTO THE OVERNIGHT/MORNING. FROM THAT POINT ON GUIDANCE FAVORS INCREASED DEEP LAYER RIDGING THROUGH MIDWEEK WITH ANY SHRA/TSRA ACTIVITY BEING DIURNAL IN NATURE. OVERALL THE BEST PRECIPITATION CHANCES WILL BE ON MONDAY AFTERNOON WHERE SLIGHT/CHANCE MTN AND FOOTHILL POPS ARE FAVORED. SOUNDINGS ON TUESDAY GIVE MUCH SUPPORT TO THE RIDGE WITH MOST OF THE AREA STRUGGLING TO BREAK ANY CAPPING THAT IS IN PLACE...THUS TUESDAYS POPS FEATURE SLIGHT CHANCES OVER THE SW MTNS. WEAK FLOW ALOFT WILL LIMIT SHEAR THUS EXPECTING ANY CONVECTION EITHER DAY TO BE PULSE IN NATURE. TEMPERATURES THROUGH THE SHORT TERM PERIOD WILL ALSO BE OF NOTE AS ZONAL FLOW OVER THE NORTH COMBINES WITH THE AFORE MENTIONED UPPER RIDGE OVER THE SOUTH TO YIELD INCREASINGLY HOT/HUMID DAYS. HIGHS BOTH MONDAY AND TUESDAY ARE EXPECTED TO BE WELL ABOVE NORMAL WITH THE PIEDMONT APPROACHING/EXCEEDING THE CENTURY MARK...POTENTIALLY BREAKING RECORDS. EXPECTING HEAT INDEX VALUES TO APPROACH DANGEROUS LEVELS WITH HEAT ADVISORIES BEING A POSSIBILITY EACH DAY. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 200 PM SAT...THE FLAT BUT STILL HOT UPPER RIDGE WILL REMAIN OVER THE SOUTHERN STATES THRU MIDWEEK...WHILE FASTER FLOW CONTINUES OVER THE RIDGE ACRS THE NERN CONUS. CONSENSUS OF THE LONG RANGE MODELS IS THAT AS A SHORTWAVE EMBEDDED IN THAT FLOW WILL LAY OUT A COLD FRONT ACRS THE OHIO VALLEY...WHICH STALLS TO OUR NORTH WED AS THE WAVE PULLS AWAY. LATEST AVBL DETERMINISTIC AND ENSEMBLE GUIDANCE HOWEVER DOES SHOW HEIGHTS BEGINNING TO FALL OVER OUR AREA THU AS A SHORTWAVE MOVES FROM THE CANADIAN PRAIRIE INTO THE GREAT LAKES REGION. THE PATTERN SUBSEQUENTLY BECOMES MORE AMPLIFIED...AND THAT FRONT IS EXPECTED TO FINALLY ARRIVE THU NIGHT. SOLUTIONS DIVERGE THEREAFTER BUT THERE ARE INDICATIONS WE WILL SEE ACTIVE WX GOING INTO NEXT WEEKEND AS A PRONOUNCED TROUGH DIGS INTO THE MISSISSIPPI VALLEY AND INTERACTS WITH THE EXISTING BOUNDARY. WE WILL CONTINUE TO FCST NEAR-RECORD MAXES WED AND THU...THOUGH THE FAVORED BLEND HAS TRENDED SLIGHTLY COOLER FROM THE LAST CYCLE...SO A HWO MENTION STILL IS UNWARRANTED. TEMPS WILL COOL A BIT FOR FRIDAY...BUT NOT RETURNING TO NEAR NORMAL UNTIL SATURDAY. CONVECTION IS POSSIBLE EACH DAY OF THE PERIOD. GFS PROFILES HAD PREVIOUSLY INDICATED POOR MIDLEVEL TEMPS WITHIN THE RIDGE WOULD KEEP MUCH OF THE PIEDMONT CAPPED WED AND THU AFTNS...BUT THE LATEST RUN SEEMS TO REFLECT A WEAKER RIDGE AND SUGGESTS FREE CONVECTION THERE. WEAK SHEAR PROFILES AND MODEST INSTABILITY MEAN PULSE STORMS WILL PROBABLY BE OF SOME CONCERN ON THESE DAYS. WEAK DOWNSLOPING WILL LIKELY LIMIT THE COVERAGE HOWEVER. TO SUMMARIZE...ON WED-THU POPS PEAK AT A HIGH CHC MTNS AND SCHC TO LOW CHC PIEDMONT. THE FRONT WARRANTS POPS PERSISTING OVERNIGHT THU NIGHT WITH MOST OF THE CWFA SOLIDLY IN CHC RANGE THRU EARLY SUNDAY ON ACCOUNT OF THE AFOREMENTIONED SYNOPTIC FEATURES. SHEAR PARAMETERS WAX LATE IN THE PERIOD BUT ARE NOT CURRENTLY INDICATIVE OF A SIGNIFICANT SEVERE THREAT. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... AT KCLT...NO FLIGHT RESTRICTIONS THRU THE PERIOD. BROAD ULVL RIDGING WILL RETURN TO THE SE CONUS AND GOOD SUBS WILL KEEP VERTICAL CLOUD DEVELOPMENT AT BAY. WINDS WILL REMAIN LIGHT THROUGH THE COLUMN WITH SFC WINDS 5-9 KTS ALIGNING S OF WEST DURING THE AFTERNOON. ELSEWHERE...ONLY RESTRICTIONS WILL BE MORNING FG/BR AT KAVL AND KHKY. SHUD BURN OFF QUICKLY AFT SUNRISE WITH GOOD SFC HEATING. DEEP HIGH PRESSURE WILL KEEP AFTERNOON CONVECTION LIMITED...MAINLY ISOL ACROSS THE NC/GA/SC MTNS WITH NO TAF MENTION NEEDED AT KAVL. RELATIVELY LIGHT WINDS WILL MAINTAIN UPVALLEY AT KAVL AND SW/LY TO W/LY ALL OTHER TERMINALS. OUTLOOK...PRECIPITATION CHANCES WILL REMAIN DIURNAL INTO THE WORK WEEK. AS A RESULT...THE GREATEST CHANCES FOR AFTERNOON SHRA/TSRA WILL BE ACROSS WESTERN NC WHERE THE LEAST SUBSIDENCE WILL RESIDE. MORNING RESTRICTIONS DUE TO FOG AND/OR STRATUS ARE POSSIBLE... PARTICULARLY WHERE HEAVY RAIN FELL THE PREVIOUS DAY. CONFIDENCE TABLE... 05-11Z 11-17Z 17-23Z 23-00Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .CLIMATE... RECORD MAXIMUM TEMPERATURES FOR NEXT WEEK...WITH YEARS IN WHICH THE VALUES WERE LAST REACHED. MONDAY JUNE 22... AVL 94 1964 CLT 98 1956 GSP 99 2006 TUESDAY JUNE 23... AVL 93 1988 CLT 98 1988 GSP 99 1988 WEDNESDAY JUNE 24... AVL 94 1952 CLT 102 1930 GSP 100 1952 THURSDAY JUNE 25... AVL 96 1952 CLT 102 1914 GSP 101 1952 && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...WIMBERLEY NEAR TERM...LG/SBK/WJM SHORT TERM...CDG LONG TERM...WIMBERLEY AVIATION...SBK CLIMATE...DEO/WIMBERLEY
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
437 AM CDT SUN JUN 21 2015 .DISCUSSION... EXCESSIVE HEAT IS THE MAIN PROBLEM OF CONCERN IN THIS FORECAST. SOUTHWEST WINDS AND HIGH DEW POINTS WERE HOLDING TEMPERATURES UP INTO THE 70S THIS MORNING WITH LOCATIONS IN AND AROUND MEMPHIS STRUGGLING TO DROP TO BELOW 80 DEGREES. SKIES WERE MOSTLY CLEAR TO PARTLY CLOUDY WITH RAIN FREE CONDITIONS. THE HRRR IS NOT SHOWING MUCH IN THE WAY OF ANY SHOWERS OR THUNDERSTORMS TODAY...THUS CONTINUED TO KEEP POPS BELOW MENTIONABLE LEVELS ALTHOUGH COULD BE A STRAY SHOWER / THUNDERSTORM. SOUTHWEST WINDS WILL CONTINUE TO PUSH HOT AIR INTO THE REGION WITH HIGHS A DEGREE OR SO HOTTER THAN YESTERDAY. WENT AHEAD AND ISSUED A HEAT ADVISORY BEGINNING THIS AFTERNOON FOR SOUTHWEST TN INCLUDING THE CITY OF MEMPHIS...EAST CENTRAL AR...AND NORTHWEST MS. IT LOOKS TO BE A BORDERLINE SITUATION THIS AFTERNOON WITH HEAT INDEX READINGS NEAR OR JUST SHY OF THE 105 DEGREE MARK...BUT PREFERRED TO ERR ON THE SIDE OF CAUTION AND THUS ISSUED THE ADVISORY. BIGGEST QUESTIONS ARE IF HIGH LEVEL CLOUDS APPROACHING FROM THE WEST WILL HAVE MUCH AFFECT ON HIGH TEMPERATURES...AND HOW MUCH SURFACE DEW POINTS WILL MIX OUT THIS AFTERNOON FROM DRIER AIR ALOFT. YESTERDAY...SURFACE DEW POINTS DID NOT MIX OUT VERY MUCH. FOR HIGH TEMPERATURES...LEANED TOWARD THE NAM / MET GUIDANCE WHICH DID A GOOD JOB FORECASTING THE HIGHS YESTERDAY. THE MIDSOUTH WILL BE SANDWICHED TODAY BETWEEN A STRONG HOT UPPER LEVEL HIGH PRESSURE SYSTEM CENTERED OVER THE SOUTHWESTERN UNITED STATES AND HIGH PRESSURE ALOFT CENTERED OFF THE ATLANTIC COAST. SOME HIGH LEVEL CLOUDS WILL OCCUR TODAY AND TONIGHT IN A WEAKNESS BETWEEN THE TWO HIGH PRESSURE SYSTEMS ESPECIALLY FROM EAST CENTRAL AR INTO NORTH MS. MONDAY AND TUESDAY...THE STRONG UPPER LEVEL RIDGE OVER THE SOUTHWESTERN UNITED STATES WILL EXPAND EASTWARD AND INCLUDE THE MIDSOUTH. THIS WILL LEAD TO VERY HOT CONDITIONS EXPANDING OVER THE MIDSOUTH WITH LITTLE IF ANY RAIN. H5 HEIGHTS ARE FORECAST BY THE GFS TO INCREASE TO NEAR 597 DM TUESDAY. CONTINUED THE HEAT ADVISORY MONDAY FOR PORTIONS OF SOUTHWEST TN...EAST CENTRAL AR AND NORTHWEST MS. THE HEAT ADVISORY MAY NEED TO BE EXPANDED IN LATER FORECASTS TO INCLUDE MORE OF THE MIDSOUTH FOR MONDAY. IN ADDITION...AS THE HEAT EXPANDS TUESDAY A HEAT ADVISORY MAY BECOMING NECESSARY FOR MUCH OF THE MIDSOUTH. WEDNESDAY...THE HEAT WILL CONTINUE WITH A SMALL CHANCE OF SHOWERS AND THUNDERSTORMS. SOME MOISTURE IS FORECAST TO INCREASE FROM THE SOUTH. TOWARD THE END OF THE WORK WEEK..THE UPPER LEVEL RIDGE IS FORECAST TO BREAK DOWN ACROSS THE MIDSOUTH WITH THE REGION MOVING INTO NORTHWEST FLOW ALOFT. THIS WILL LEAD TO INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS ALONG WITH A DECREASE IN HIGH TEMPERATURES. WILL ALSO NEED TO WATCH FOR DEVELOPMENT OF MESOSCALE CONVECTIVE SYSTEMS UPSTREAM AS WE EVOLVE INTO NORTHWEST FLOW ALOFT...BUT THIS IS DIFFICULT TO PINPOINT AT THIS TIME. THE ECMWF AND GFS DIFFER ON THE POSSIBLE PASSAGE OF A COLD FRONT OVER THE WEEKEND. JCL && .AVIATION... 06Z TAFS VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. WINDS WILL BE S-SW BETWEEN 5-10 KT. && .MEG WATCHES/WARNINGS/ADVISORIES... AR...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 7 PM CDT MONDAY FOR CRITTENDEN-CROSS-LEE AR-PHILLIPS-ST. FRANCIS. MO...NONE. MS...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 7 PM CDT MONDAY FOR COAHOMA-DESOTO-PANOLA-QUITMAN-TALLAHATCHIE-TATE-TUNICA. TN...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 7 PM CDT MONDAY FOR SHELBY. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1115 PM CDT SAT JUN 20 2015 .UPDATE...AVIATION DISCUSSION. && .PREV DISCUSSION... /ISSUED 905 PM CDT SAT JUN 20 2015/ DISCUSSION...WATER VAPOR SATELLITE TRENDS/00Z UPPER AIR ANALYSIS INDICATES AN UPPER LEVEL RIDGE PRESENT OVER THE LOWER MISSISSIPPI VALLEY WHILE A MESOSCALE CONVECTIVE SYSTEM /MCS/ HAS DEVELOPED OVER SOUTHEAST IOWA/NORTHEAST MISSOURI. ISOLATED SHOWERS AND THUNDERSTORMS OVER THE PAST COUPLE OF HOURS HAVE DIMINISHED WITH THE LOSS OF DAYTIME INSTABILITY AND THE ONLY REMNANTS IS AN ISOLATED RAIN SHOWER OVER SOUTHERN HAYWOOD AND MADISON COUNTIES IN TENNESSEE. LATEST HRRR AND 00Z WRF INDICATE ANY ADDITIONAL SHOWER/THUNDERSTORM POTENTIAL WILL REMAIN MINIMAL AT BEST. WILL MAKE SOME MINOR ADJUSTMENTS TO FORECAST TO ACCOUNT FOR LATEST TRENDS. OTHERWISE...FORECAST OVERALL IS IN GREAT SHAPE. UPDATED GRIDS WILL BE AVAILABLE SHORTLY. CJC PREV DISCUSSION... /ISSUED 616 PM CDT SAT JUN 20 2015/ UPDATE...AVIATION DISCUSSION. PREV DISCUSSION... /ISSUED 252 PM CDT SAT JUN 20 2015/ DISCUSSION... HEAT AND HUMIDITY WILL DOMINATE THE FIRST HALF OF THE FORECAST PERIOD AS AN UPPER RIDGE OF HIGH PRESSURE GRADUALLY BUILDS INTO THE AREA OVER THE NEXT COUPLE OF DAYS. CURRENTLY...DIURNAL SHOWERS AND THUNDERSTORMS ARE POPPING UP ACROSS PORTIONS OF EASTERN ARKANSAS AND NORTHWEST MISSISSIPPI. TEMPERATURES HAVE WARMED INTO THE UPPER 80S TO LOWER 90S THUS FAR TODAY. CURRENT HEAT INDEX READING IN MEMPHIS IS AROUND 101-102 DEGREES. THE DIURNAL CONVECTION SHOULD DIE OFF AROUND 7 PM. CIRRUS CURRENTLY OVER TEXAS WILL SPREAD OVER THE CWA THIS SHOULD KEEP LOW TEMPERATURES UP COMPARED TO LAST NIGHT. READINGS WILL BE IN THE MID TO UPPER 70S. EXPECT CONDITIONS TO BE WARMER ON SUNDAY THUS HEAT INDICES COULD REACH 105 DEGREES IN A FEW LOCATIONS. A HEAT ADVISORY MAY BECOME NECESSARY. THE HEAT WILL BUILD DURING THE EARLY TO MIDDLE PART OF NEXT WEEK AS THE RIDGE MOVES INTO THE AREA. MODELS ARE WAVERING ON HOW STRONG THE RIDGE WILL BE THUS ISOLATED DIURNAL CONVECTION COULD OCCUR ON ABOUT EACH DAY BUT NOT ENOUGH AGREEMENT AMONG MODELS TO PUT ANY MENTION IN FORECAST YET. BY WEDNESDAY...BETTER AGREEMENT OCCURS THUS HAVE ADDED IN MENTION OF SHOWERS AND THUNDERSTORMS. HIGHS WILL GENERALLY BE IN THE MID TO UPPER 90S. HEAT INDICES SHOULD HIT AROUND 105 DEGREES EACH DAY. BY THURSDAY...THE UPPER RIDGE BEGINS TO BREAK DOWN. CHANCES FOR SHOWERS AND THUNDERSTORMS WILL INCREASE FROM THURSDAY INTO EARLY NEXT WEEKEND AS A COLD FRONT MOVES INTO THE AREA. TEMPERATURES WILL RETURN TO NORMAL DURING THIS TIME PERIOD DUE TO CLOUD COVER AND CONVECTION. KRM && .AVIATION...06Z TAFS VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. WINDS WILL BE S-SW BETWEEN 5-10 KT. && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
351 AM CDT SUN JUN 21 2015 .TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM. SOME PATCHY FOG DEVELOPED IN THE FAR SOUTH CENTRAL AND SOUTHWEST THAT SAW THE BETTER RAINFALL ON SATURDAY. WEB CAMS AND OBS CURRENTLY SHOW CONDITIONS ARE NOT WIDESPREAD ENOUGH FOR AN ADVISORY...PROBABLY DUE TO SLOWLY RETREATING CIRRUS SHIELD. WILL CONTINUE TO HANDLE WITH SPS AND MONITOR CLOSELY. OTHERWISE LOOKING FOR QUIET WEATHER TODAY INTO THIS EVENING AS WEAK HIGH PRESSURE MOVES ACROSS REGION. SHOULD SEE ANY LOW STRATUS/FOG MIX OUT BY MID TO LATE MORNING WITH ENOUGH SUN AND 925 MB TEMPS SUPPORTING HIGHS IN THE LOW 80S INLAND...WITH UPPER 60S TO MID 70S CLOSER TO THE LAKE. CYCLOGENESIS IN THE CENTRAL PLAINS AHEAD OF POTENT SHORT WAVE...WITH PRECIPITATION DEVELOPING IN THE WARM ADVECTION REGIME...TRIGGERING A THUNDERSTORM COMPLEX OVER SOUTH DAKOTA. WILL BRING IN CHANCE POPS INTO THE WEST BETWEEN 09Z AND 12Z WITH CONVERGENCE ALONG LEADING EDGE OF STRONGER LOW-LEVEL JET. .MONDAY INTO MONDAY EVENING...FORECAST CONFIDENCE IS MEDIUM. ZONAL MID LEVEL FLOW WILL START TO BUCKLE AS A SHORT WAVE TROUGH PROPAGATES EAST ALONG THE US/CANADIAN BORDER. WHILE MUCH OF THE MID LEVEL LIFT FROM THIS FEATURE WILL STAY NORTH OF THE REGION...IT WILL CAUSE A TIGHTENING OF MID LEVEL HEIGHTS AND INCREASE WIND SPEEDS INTO THE 70-80KT RANGE BY AFTERNOON/EVENING. IT WILL ALSO AID IN THE DEVELOPMENT OF A SURFACE LOW OVER THE NORTHERN PLAINS EARLY ON MONDAY WHICH WILL HELP TO INCREASE LOW LEVEL SOUTHERLY FLOW INTO THE REGION. A STRENGTHENING LOW LEVEL JET WILL NOSE UP INTO EASTERN MINNESOTA/WESTERN WISCONSIN AROUND DAYBREAK MONDAY BEFORE SHIFTING EASTWARD INTO THE GREAT LAKES THROUGH THE MORNING. THE FORCING ALONG THE NOSE OF THE LLJ SHOULD BE ENOUGH TO MAINTAIN CONVECTION ACROSS EASTERN MINNESOTA ON INTO WISCONSIN THROUGH THE REST OF THE MORNING. EXACTLY WHERE THIS CONVECTION TRACKS IS STILL A BIT UNCERTAIN...BUT THE CENTRAL TO NORTHERN PORTIONS OF WISCONSIN SEEMS TO BE A CONVERGENCE POINT IN THE 21.00Z MODELS. ELEVATED INSTABILITY WILL BE ON THE INCREASE AND FEEDING INTO THESE MORNING STORMS...SO WILL HAVE TO WATCH FOR THE POTENTIAL OF SOME SEVERE WEATHER IN THE MORNING HOURS AS THIS FEATURE MOVES THROUGH. LARGE HAIL AND DAMAGING WINDS ARE THE MAIN CONCERNS WITH THIS FIRST WAVE OF STORMS IF THEY ENTER THE REGION. THE FOCUS THEN SHIFTS TO THE AFTERNOON AND THE SECOND ROUND OF CONVECTION WHICH IS EXPECTED TO INITIATE AHEAD OF THE COLD FRONT. THE 21.00Z NAM/GFS/ECMWF/GEM ALL ARE CONSISTENT WITH TAKING THE SURFACE LOW NORTH OF THE REGION THROUGH THE UP OF MICHIGAN WITH A TRAILING COLD FRONT ANGLING DOWN TOWARD EASTERN IOWA BY 00Z TUESDAY. THIS SHOULD FIRMLY PUT SOUTHEASTERN WISCONSIN INTO THE WARM SECTOR THROUGH MUCH OF THE AFTERNOON. A WARM LAYER AROUND 700MB SHOULD KEEP SOUTHERN WISCONSIN CAPPED OFF THROUGH THE EARLY PORTION OF THE AFTERNOON AND ALLOW FOR THE ENVIRONMENT TO BECOME HIGHLY UNSTABLE AS SURFACE TEMPERATURES CLIMB INTO THE 80S AND DEW POINTS RISE TO THE LOW 70S. SB/MLCAPE SHOULD APPROACH 4000 J/KG BASED ON MODIFIED 21.00Z NAM/GFS SOUNDINGS WHICH ARE STILL PRODUCING TOO HIGH OF SFC DEW POINTS OF AROUND 77-80F. THIS CAP SHOULD SHIFT TO THE EAST BY MID AFTERNOON AND ALLOW FOR CONVECTION TO INITIATE AHEAD OF THE FRONT. 0-6KM SHEAR LOOKS VERY FAVORABLE FOR ORGANIZING CONVECTION...BUT DOES LOOK FAIRLY UNIDIRECTIONAL WITH LITTLE VEERING FROM THE SOUTHWEST TO WEST SURFACE WINDS GOING UP TO WESTERLY MID LEVEL WINDS. THE ONLY SOURCE FOR SOME BETTER LOW LEVEL SOUTHEASTERLIES WOULD BE IF THERE IS ANY LEFTOVER OUTFLOW BOUNDARIES FROM THE MORNING CONVECTION THOUGH THE INCREASING SOUTHERLY LOW LEVEL FLOW MAY WIPE ANY OF THIS OUT. THE 0-6KM SHEAR VECTOR DOES ANGLE ABOUT 45 DEGREES OFF OF THE BOUNDARY...SO SOME OF THE INITIAL CONVECTION COULD START OUT AS DISCRETE SUPERCELLS BEFORE MERGING INTO A SQUALL LINE AS THE FRONT SWINGS THROUGH. 0-1KM WIND SHEAR DOES LOOK STRONG ENOUGH TO SUPPORT TORNADO DEVELOPMENT...BUT SEEMS TO BE ON THE DECLINE THROUGH THE AFTERNOON AS THE LLJ SHIFTS EAST. OVERALL...QUITE A BIT OF FAVORABLE CONDITIONS IN PLACE FOR A SEVERE WEATHER OUTBREAK...BUT ALSO STILL SOME QUESTIONS REGARDING STORM EVOLUTION...HOW FAST CONVECTION INITIATES ONCE THE CAP SHIFTS EAST...AND HOW BIG IS THE TORNADO THREAT. TUESDAY THROUGH SATURDAY...FORECAST CONFIDENCE IS LOW. ZONAL FLOW ALOFT LINGERS THROUGH THE REST OF THE WEEK...BUT STARTS TO BECOME MORE NORTHWESTERLY AS THE WEEK PROGRESSES. MUCH OF THE PRECIPITATION CHANCES WILL BE TIED TO ANY QUICK MOVING SHORT WAVE TROUGHS THAT PROPAGATE THROUGH THE FLOW. THE MAIN SURFACE WARM/STATIONARY FRONT LOOKS LIKE IT WILL STAY TO THE SOUTH OF THE REGION...BUT COULD LIFT NORTH WITH ANY SYSTEM THAT MOVES IN. TRYING TO TIME DOWN ANY OF THESE SYSTEM IS TOUGH AT THIS POINT...THOUGH THE 21.00Z GFS/ECMWF/GEM DO TRY AND DEVELOP SOME CONVECTION ALONG THE FRONT TUESDAY NIGHT INTO THURSDAY. TEMPERATURES SHOULD STAY SEASONAL WITH THE REGION STAYING MAINLY ON THE COOL SIDE OF THE BOUNDARY THROUGH MUCH OF THE WEEK. && .AVIATION/12Z TAFS/... SEEING PATCHY/AREAS OF FOG AND IFR CIGS IN FAR SOUTH CENTRAL/SOUTHWEST LOCATIONS THAT HAVE ABUNDANT LOW-LEVEL MOISTURE FROM SATURDAY RAINS. LOWER CLOUD COVER BEING REVEALED ON SATELLITE FOG PRODUCT BELOW SLOWLY DEPARTING CIRRUS SHIELD SHOWS HOW PATCHY IT CURRENTLY IS. SREF VSBY PROBABILITY FORECASTS HANDLING THE CURRENT SITUATION BETTER THAN THE MORE WIDESPREAD HRRR SO NOT EXPECTING CONDITIONS TO DETERIORATE EVERYWHERE.WILL MONITOR CLOSELY...BUT EXPECT ONLY LOCAL IFR VSBYS/CIGS THAT WILL MIX OUT BY MID MORNING. THEN VFR CONDITIONS THROUGH THE REMAINDER OF THE FORECAST. WARM AIR ADVECTION SHOWERS AND THUNDERSTORMS WILL BEGIN TO MOVE INTO WESTERN FORECAST AREA BETWEEN 09Z AND 12Z MONDAY...WARRANTING NO MORE THAN A PROB30 AT KMSN AND NOTHING EAST UNTIL AFTER 12Z. && .MARINE... PATCHY FOG IS EXPECTED TO LINGER TONIGHT INTO SUNDAY...WITH DEW POINTS JUST HIGH ENOUGH OVER THE LAKE MICHIGAN WATER TEMPERATURES. NOT EXPECTING ANY DENSE FOG AT THIS TIME. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ TODAY/TONIGHT AND AVIATION/MARINE...REM MONDAY THROUGH SATURDAY...HALBACH
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1124 AM EDT SUN JUN 21 2015 .SYNOPSIS... THE REMNANTS OF TROPICAL DEPRESSION BILL WILL CONTINUE TO LIFT NORTHEAST AWAY FROM THE REGION TODAY. A WEAK COLD FRONT FOLLOWS TONIGHT WITH A STRONGER COLD FRONT EXPECTED TO SWING THROUGH OUR REGION LATE TUESDAY. A COMPLEX FRONTAL SYSTEM WILL AFFECT THE MID ATLANTIC STATES LATE IN THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WITH THE REMNANTS OF BILL PULLING AWAY FROM OUR REGION AND TRACKING UP TOWARD SOUTHERN NEW ENGLAND, WE SIGNIFICANTLY LOWERED POPS ACROSS THE FORECAST AREA THROUGH THE REST OF THE MORNING, AS MOST LOCATIONS WILL EXPERIENCE DRY CONDITIONS AND GRADUAL CLEARING SKIES OVER THE NEXT SEVERAL HOURS. FOR THIS AFTERNOON, WITH A DESTABILIZING ATMOSPHERE AND AN APPROACHING SHORTWAVE AND COLD FRONT FROM THE WEST, WE INTRODUCE SOME CHANCE POPS, ESPECIALLY FOR OUR NORTHWEST ZONES, WITH BOTH THE HRRR AND RAP SUPPORTING THIS REGION FOR POSSIBLE CONVECTIVE DEVELOPMENT. HOURLY TEMPS AND DEWPOINTS WERE ALSO ADJUSTED USING THE LAV/LAMP GUIDANCE. OTHERWISE...HIGH TEMPS LOOK TO BE AROUND 90, AND DEW POINTS WILL BE CLOSE TO 70 WHICH WILL MAKE IT FEEL A BIT STICKY. THE ONLY SAVING GRACE WILL BE THAT THE WIND WILL BECOME MORE WLY BEHIND THE CFP AND IT WILL BE A BIT BREEZY. THE SUMMER SOLSTICE OCCURS AT 1238 PM. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/... AFTER ANY EVE SHWRS/TSTMS AS MENTIONED ABOVE, WK HIGH PRES WILL BUILD IN FOR SUN NIGHT AND PRECIP WILL END AND HUMIDITY LEVELS WILL DROP AS THE WIND CONTINUES FROM THE W AND EVEN PSBLY NW BRINGS IN DRIER AIR. && .LONG TERM /MONDAY THROUGH SATURDAY/... DRAFT: **HOT TUESDAY, POSSIBLY NEAR RECORD** 500 MB: WARM HIGH PRESSURE COVERS THE SOUTHERN UNITED STATES WITH A PREDOMINANTLY WEST-NORTHWEST FLOW ALONG THE PERIPHERY OF THE RIDGE IN THE NORTHERN UNITED STATES TRENDING TO A TROUGH OVER THE WESTERN GREAT LAKES NEXT WEEKEND. CALENDAR DAY AVERAGES TUESDAY WILL BE 5 TO 10 DEGREES ABOVE NORMAL, AND THEN PROBABLY WITHIN 3 DEGREES OF NORMAL WEDNESDAY THROUGH SUNDAY. DAYTIME MAX`S FRIDAY MIGHT BE 10 DEGREES OR MORE BELOW NORMAL-A COOLISH DAY! FORECAST BASIS: UNLESS OTHERWISE NOTED, A 50 50 BLEND 12Z/21 GFS/NAM MOS GUIDANCE MONDAY NIGHT-TUESDAY NIGHT, 12Z/21 MEX MOS WEDNESDAY AND WEDNESDAY NIGHT, THEN THE 1521Z/21 WPC GRIDDED ELEMENTS OF MAX/MIN TEMP, 12 HOUR POP, 6 HOUR DEWPOINT-SKY-WIND FROM THURSDAY THROUGH NEXT MONDAY. THE DAILIES... MONDAY...FOR THE MOST PART, MONDAY LOOKS VERY NICE. PLENTY OF SUNSHINE. PWAT ONLY 1 INCH! SFC DEWPOINTS ALMOST 10F LOWER THAN THE VALUES OF SUNDAY AFTERNOON. WEST WIND GUSTS GENERALLY UNDER 15 MPH. CONFIDENCE: ABOVE AVERAGE. MONDAY NIGHT...WAA MID AND HIGH CLOUD ARRIVES LATE. SMALL CHANCE AND NOT YET MENTIONED, OF A SHOWER GRAZING THE POCONOS AT DAWN TUESDAY. CONFIDENCE ON SCENARIO: ABOVE AVERAGE. TUESDAY...HOT AND HUMID! A COLD FRONT IS EXPECTED TO ARRIVE IN THE LATTER HALF OF THE DAY. AS SUCH, SHOULD SEE CONVECTIVE CHANCES AHEAD OF AND WITH THE FRONT. SREF PWAT 1.5 TO 1.75 INCHES DURING THE AFTERNOON/EVENING. MLCAPE OVER 2000J BY LATE IN THE DAY. 0-6KM BULK QUITE STRONG WITH 50 KT AT 500MB NEAR AND N I-78 AND TT LOWER 50S WITH SWI -4. LANCE POINTED OUT THE ELEVATED MIXED LAYER (EML) IN THE SOUNDING AND NICELY SEEN IN BOTH THE EC AND GFS PLAN VIEW BREAKING FREE FROM THE OHIO VALLEY MONDAY AND APPEARING ALONG AND SOUTH OF THE MASON DIXON LINE 18Z TUESDAY. THE EML OFFERS ADDITIONAL STRENGTH POTENTIAL IF CONVECTION ERUPTS. WE`RE ALSO NOTING HIGH FORECAST SHERB VALUES FOR OUR AREA TUESDAY (VALUES OVER 1). POPS LOOKED A LITTLE LOW BUT ITS POSSIBLE THAT THERE MIGHT NOT BE ENOUGH CONVERGENCE TO INITIATE CONVECTION. CONFIDENCE ON HEAT INCLUDING 95-96F AT PHL IS ABOVE AVG. CONFIDENCE ON CONVECTION: AVERAGE WITH MODELED PARAMETERS FOR SVR IMPRESSIVE. WEDNESDAY...PROBABLY DRY AND NICE AGAIN. CONFIDENCE: AVERAGE OR A BIT ABOVE. THURSDAY THROUGH SATURDAY...COMPLEX AND NOT GIVEN TO ADDING MUCH INFORMATION EXCEPT TO SAY THERE IS A CHANCE OF PERIODIC CONVECTION, ESPECIALLY NEXT SATURDAY. CONFIDENCE OVERALL IS AVERAGE. && .AVIATION /15Z SUNDAY THROUGH THURSDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. CONTINUED IMPROVEMENT FROM MVFR CIGS TO VFR CIGS IS EXPECTED THROUGH LATE MORNING FOR THE TAF SITES. WEST-NORTHWEST WINDS IN THE 10 TO 15 KNOT RANGE WILL GUST AT TIMES TO BETWEEN 20 TO 25 KNOTS, BEFORE SUBSIDING THIS EVENING. LATER IN THE DAY, THERE COULD BE SCATTERED SHWRS OR EVEN A TSTM AS THE CDFNT ASSOCD WITH THE LOW AND AN UPR LVL DISTURBANCE PASSES BY. HOWEVER, AREAL COVERAGE IS ONCE AGAIN EXPECTED TO BE SMALL, SO NOT INCLUDING IN THE TAFS AT THIS TIME. OUTSIDE OF ANY SHRA/TSRA, VFR CONDS SHUD PREVAIL FOR THE BALANCE OF THE DAY AFTER THIS MORNING. OUTLOOK... MONDAY...VFR SCT AOA 5000 FT. NW GUST 20 POSSIBLY 25 KT EARLY THEN DIMINISHES LATE DAY. CONFIDENCE: ABOVE AVERAGE. MONDAY NIGHT...VFR LIGHT WIND. VFR CIGS DEVELOPING LATE AT NIGHT. CONFIDENCE: ABOVE AVERAGE. TUESDAY...VFR SCT-BKN AOA 5000 FT LOWERING TO BRIEF IFR CONDITIONS WITH SHOWERS AND STRONG GUSTY TSTORMS LATE IN THE DAY OR MORE LIKELY EVENING. GRADIENT SW WIND GUSTS 20-25 KT SHIFT NW AT NIGHT BUT GUSTS UNDER 20 KT. CONFIDENCE: ABOVE AVERAGE WEDNESDAY...VFR DAYTIME WITH POSSIBLE CIGS ARRIVING AT NIGHT. NW GUSTS UNDER 15 KT BECOMING LIGHT NE AT NIGHT. CONFIDENCE: AVERAGE THURSDAY...VFR CIGS DURING THE DAY WITH CHANCE OF A SHOWER OR TSTM. MVFR/IFR CONDS IN STRATUS-FOG POSSIBLE LATE AT NIGHT. CONFIDENCE: AVERAGE. && .MARINE... THE SCA WILL BE CONTINUED THRU 22/00Z. AFTER THAT CONFIDENCE IS MUCH LOWER SO IT WAS NOT EXTENDED ATTM. IF THERE NEEDS TO BE AN EXTENSION, IT WUD LIKELY BE FOR SEAS AS WIND SHUD BE BELOW CRITERIA. OTHERWISE, ONCE WE GET BEYOND THIS SCA, NO ADDITIONAL MARINE FLAGS ARE ANTICIPATED. OUTLOOK... MONDAY...SCA POSSIBLE IN THE MORNING FOR THE ATLC WATERS THEN NW WINDS SUBSIDE AFTERNOON/EVENING. CONFIDENCE: AVERAGE. TUESDAY...SCA SW WIND GUSTS POSSIBLE DURING THE AFTERNOON ALONG THE NEARSHORE WATERS. CONFIDENCE: AVERAGE. WEDNESDAY AND MOST OF THURSDAY...WINDS AND SEAS SHOULD STAY BELOW SCA CRITERIA. CONFIDENCE: AVERAGE. && .RIP CURRENTS... 11 AM ASSESSMENT INCLUDING INFORMATION GATHERED FROM OUR 1015 AM CONFERENCE CALL WITH 4 BEACH PATROLS. THE FORMATION RISK WAS PROBABLY HIGHEST THIS MRNG. NOW THAT WINDS ARE WLY, WE`RE NO LONGER BUILDING THE WATER LEVEL IN THE SURF ZONE. ON THE OTHER HAND AS THE TIDE MOVES INTO THE LOWER HALF OF THE TIDE CYCLE AFTER 2 PM...WHATEVER RISK FOR THE FORMATION OF DANGEROUS RIP CURRENTS EXISTS, IT TENDS TO ELEVATE DUE TO SAND BAR EXPOSURE AND RESIDUAL WATER BUILD UP. LONG PERIOD SWELLS ARE AT A MINIMUM TODAY SO THE CONTRIBUTUION OF WATER BUILDUP BEHIND THE BARS SHOULD BE PRIMARILY ASSOCIATED WITH A GRADUALLY LOWERING SHORT PERIOD SOUTHERLY SWELL. WE HAD A COUPLE OF REPORTS FROM NORTH WILDWOOD AND ISLAND BEACH STATE PARK ABOUT CONCERN THAT THE RIP CURRENT FORMATION LATE THIS MORNING WAS BORDERING HIGH RISK. FOR NOW..DUE TO THE EXPECTED WESTERLY WIND IMPACT, WE`LL MAINTAIN A MODERATE RISK FOR THE FORMATION OF DANGEROUS RIP CURRENTS ALONG THE NJ COAST. MEDIA ARE RECOMMENDED TO ADVISE CAUTION FOR SWIMMERS GOING INTO THE WATERS THIS AFTERNOON AND PLEASE SWIM IN THE PRESENCE OF LIFEGUARDS. THERE IS MORE THAN THE USUAL RISK FOR THE FORMATION OF DANGEROUS RIP CURRENTS. && .CLIMATE... VULNERABLE TO THE MAX TEMP WITHIN 2F OF EQUALING THE RECORD MAX TEMPERATURES FOR TUESDAY JUNE 23 KACY 98-1988 KILG 100-1894 KPHL 97-1888 KABE 95-1965 KTTN 97-1894 KRDG 96-1908 KMPO 90-1908 KGED 100-1988 RAINFALL: THE PAST WEEK FROM THE 14TH THROUGH 20TH "NOT INCLUDING TODAYS SO FAR". A GRAPHIC AND LINK WITH MORE DETAIL WILL POST ON OUR SOCIAL MEDIA FB PAGE AND WILL BE TWEETED. KMPO 2.07 7 CONSEC DAYS OF SOME RAIN KRDG 1.69 7 CONSEC DAYS OF SOME RAIN KABE 1.91 6 OF 7 DAYS IT RAINED KTTN 0.84 6 OF 7 DAYS IT RAINED KPHL 1.49 7 CONSEC DAYS OF RAIN KILG 2.70 7 CONSEC DAYS OF RAIN KACY 1.18 6 OF 7 DAYS IT RAINED KGED 1.06 6 OF 7 DAYS IT RAINED WHEN WE ADD TODAYS RAINFALL THROUGH 9 AM... IT WILL HAVE RAINED 8 CONSEC DAYS AT KMPO/KRDG/KPHL AND KILG AND 7 OF 8 ELSEWHERE. KILG: THE 9.18 INCHES FOR THE MONTH AS OF 845 AM THIS MORNING IS STILL 4TH WETTEST JUNE ON RECORD. 2013 13.66 2003 9.90 2006 9.40 2015 9.18 POR FOR THIS STATION IN JUNE IS BACK TO 1896. INTERESTINGLY, IN THE NEARLY 120 YEAR PERIOD OF RECORD, THE TOP 4 MONTHLY JUNE RAINFALL TOTALS ALL OCCURRED IN THE LAST 13 YEARS. TEMPS THROUGH THE 20TH ARE AVERAGING 1.3 TO 2.4 DEGREES ABOVE NORMAL THROUGHOUT THE CWA. && .EQUIPMENT... RTPPHI IS MISSING A FAIR AMOUNT OF DATA THIS MORNING DUE TO THE FAA MAINTENANCE PERIOD FROM 315Z-815Z OVERNIGHT. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ450>455. && $$ SYNOPSIS...DRAG/JOHNSON NEAR TERM...KLINE/NIERENBERG SHORT TERM...NIERENBERG LONG TERM...DRAG AVIATION...DRAG/KLINE/NIERENBERG MARINE...DRAG/NIERENBERG RIP CURRENTS...DRAG 1123 CLIMATE... EQUIPMENT...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1033 AM EDT SUN JUN 21 2015 .SYNOPSIS... THE REMNANTS OF TROPICAL DEPRESSION BILL WILL CONTINUE TO LIFT NORTHEAST AWAY FROM THE REGION TODAY. A WEAK COLD FRONT FOLLOWS TONIGHT WITH A STRONGER COLD FRONT EXPECTED TO SWING THROUGH OUR REGION LATE TUESDAY. A COMPLEX FRONTAL SYSTEM WILL AFFECT THE MID ATLANTIC STATES LATE IN THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WITH THE REMNANTS OF BILL PULLING AWAY FROM OUR REGION AND TRACKING UP TOWARD SOUTHERN NEW ENGLAND, WE SIGNIFICANTLY LOWERED POPS ACROSS THE FORECAST AREA THROUGH THE REST OF THE MORNING, AS MOST LOCATIONS WILL EXPERIENCE DRY CONDITIONS AND GRADUAL CLEARING SKIES OVER THE NEXT SEVERAL HOURS. FOR THIS AFTERNOON, WITH A DESTABILIZING ATMOSPHERE AND AN APPROACHING SHORTWAVE AND COLD FRONT FROM THE WEST, WE INTRODUCE SOME CHANCE POPS, ESPECIALLY FOR OUR NORTHWEST ZONES, WITH BOTH THE HRRR AND RAP SUPPORTING THIS REGION FOR POSSIBLE CONVECTIVE DEVELOPMENT. HOURLY TEMPS AND DEWPOINTS WERE ALSO ADJUSTED USING THE LAV/LAMP GUIDANCE. OTHERWISE...HIGH TEMPS LOOK TO BE AROUND 90, AND DEW POINTS WILL BE CLOSE TO 70 WHICH WILL MAKE IT FEEL A BIT STICKY. THE ONLY SAVING GRACE WILL BE THAT THE WIND WILL BECOME MORE WLY BEHIND THE CFP AND IT WILL BE A BIT BREEZY. THE SUMMER SOLSTICE OCCURS AT 1238 PM. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/... AFTER ANY EVE SHWRS/TSTMS AS MENTIONED ABOVE, WK HIGH PRES WILL BUILD IN FOR SUN NIGHT AND PRECIP WILL END AND HUMIDITY LEVELS WILL DROP AS THE WIND CONTINUES FROM THE W AND EVEN PSBLY NW BRINGS IN DRIER AIR. && .LONG TERM /MONDAY THROUGH SATURDAY/... FEW CHANGES MADE TO THE LONG TERM OVERNIGHT TO FOCUS ON CURRENT EVENT. PREVIOUS LONG TERM DISCUSSION: **RATHER HOT TUESDAY, POSSIBLY NEAR RECORD** 500 MB: WARM HIGH PRESSURE COVERS THE SOUTHERN UNITED STATES WITH A PREDOMINANTLY ZONAL FLOW IN THE NORTHERN UNITED STATES TRENDING TO A TROUGH OVER THE MIDWEST NEXT WEEKEND. JUNE THROUGH THE FIRST 19 DAYS HAS AVERAGED 1 TO 2.5 DEGREES ABOVE NORMAL. CALENDAR DAY AVERAGES MONDAY AND TUESDAY WILL AVERAGE 5 TO 10 DEGREES ABOVE NORMAL, NEAR 5 ABOVE NORMAL WEDNESDAY AND THEN PROBABLY NEAR NORMAL NEXT THURSDAY-FRIDAY-SATURDAY. FORECAST BASIS: UNLESS OTHERWISE NOTED, A 50 50 BLEND 12Z/20 GFS/NAM MOS GUIDANCE SUNDAY NIGHT-MONDAY NIGHT, 12Z/20 MEX MOS TUESDAY AND TUESDAY NIGHT, THEN THE 1521Z/20 WPC GRIDDED ELEMENTS OF MAX/MIN TEMP, 12 HOUR POP, 6 HOUR DEWPOINT-SKY-WIND FROM WEDNESDAY THROUGH NEXT SUNDAY. THE DAILIES... MONDAY...FOR THE MOST PART, MONDAY LOOKS VERY NICE. PLENTY OF SUNSHINE. PWAT ONLY 1 INCH! SFC DEWPOINTS ALMOST 10F LOWER THAN THE VALUES OF SUNDAY AFTERNOON. WEST WIND GUSTS GENERALLY UNDER 15 MPH. CONFIDENCE: ABOVE AVERAGE. MONDAY NIGHT...WAA MID AND HIGH CLOUD ARRIVES LATE. SMALL CHANCE AND NOT YET MENTIONED, OF A SHOWER GRAZING THE POCONOS AT DAWN TUESDAY. CONFIDENCE ON SCENARIO: ABOVE AVERAGE. TUESDAY...HOT AND HUMID! A COLD FRONT IS EXPECTED TO ARRIVE IN THE LATTER HALF OF THE DAY. AS SUCH, SHOULD SEE CONVECTIVE CHANCES AHEAD OF AND WITH THE FRONT. SREF PWAT 1.5 TO 1.75 INCHES DURING THE AFTERNOON/EVENING. MLCAPE OVER 2000J BY LATE IN THE DAY. 0-6KM BULK QUITE STRONG WITH 50 KT AT 500MB NEAR AND N I-78 AND TT LOWER 50S WITH SWI -4. LANCE POINTED OUT THE ELEVATED MIXED LAYER (EML) IN THE SOUNDING AND NICELY SEEN IN BOTH THE EC AND GFS PLAN VIEW BREAKING FREE FROM THE OHIO VALLEY MONDAY AND APPEARING ALONG AND SOUTH OF THE MASON DIXON LINE 18Z TUESDAY. THE EML OFFERS ADDITIONAL STRENGTH POTENTIAL IF CONVECTION ERUPTS. WE`RE ALSO NOTING HIGH FORECAST SHERB VALUES FOR OUR AREA TUESDAY (VALUES OVER 1). POPS LOOKED A LITTLE LOW BUT ITS POSSIBLE THAT THERE MIGHT NOT BE ENOUGH CONVERGENCE TO INITIATE CONVECTION. CONFIDENCE ON HEAT INCLUDING 95-96F AT PHL IS ABOVE AVG. CONFIDENCE ON CONVECTION: AVERAGE WITH MODELED PARAMETERS FOR SVR IMPRESSIVE. WEDNESDAY...PROBABLY DRY AND NICE AGAIN. CONFIDENCE: AVERAGE OR A BIT ABOVE. THURSDAY THROUGH SATURDAY...COMPLEX AND NOT GIVEN TO ADDING MUCH INFORMATION EXCEPT TO SAY THERE IS A CHANCE OF PERIODIC CONVECTION, ESPECIALLY NEXT SATURDAY. CONFIDENCE OVERALL IS AVERAGE. && .AVIATION /14Z SUNDAY THROUGH THURSDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. CONTINUED IMPROVEMENT FROM MVFR CIGS TO VFR CIGS IS EXPECTED THROUGH LATE MORNING FOR THE TAF SITES. WEST-NORTHWEST WINDS IN THE 10 TO 15 KNOT RANGE WILL GUST AT TIMES TO BETWEEN 20 TO 25 KNOTS, BEFORE SUBSIDING THIS EVENING. LATER IN THE DAY, THERE COULD BE SCATTERED SHWRS OR EVEN A TSTM AS THE CDFNT ASSOCD WITH THE LOW AND AN UPR LVL DISTURBANCE PASSES BY. HOWEVER, AREAL COVERAGE IS ONCE AGAIN EXPECTED TO BE SMALL, SO NOT INCLUDING IN THE TAFS AT THIS TIME. OUTSIDE OF ANY SHRA/TSRA, VFR CONDS SHUD PREVAIL FOR THE BALANCE OF THE DAY AFTER THIS MORNING. OUTLOOK... MONDAY...VFR SCT AOA 5000 FT. NW GUST 20 POSSIBLY 25 KT EARLY THEN DIMINISHES LATE DAY. CONFIDENCE: ABOVE AVERAGE. MONDAY NIGHT...VFR LIGHT WIND. VFR CIGS DEVELOPING LATE AT NIGHT. CONFIDENCE: ABOVE AVERAGE. TUESDAY...VFR SCT-BKN AOA 5000 FT LOWERING TO BRIEF IFR CONDITIONS WITH SHOWERS AND STRONG GUSTY TSTORMS LATE IN THE DAY OR MORE LIKELY EVENING. GRADIENT SW WIND GUSTS 20-25 KT SHIFT NW AT NIGHT BUT GUSTS UNDER 20 KT. CONFIDENCE: ABOVE AVERAGE WEDNESDAY...VFR DAYTIME WITH POSSIBLE CIGS ARRIVING AT NIGHT. NW GUSTS UNDER 15 KT BECOMING LIGHT NE AT NIGHT. CONFIDENCE: AVERAGE THURSDAY...VFR CIGS DURING THE DAY WITH CHANCE OF A SHOWER OR TSTM. MVFR/IFR CONDS IN STRATUS-FOG POSSIBLE LATE AT NIGHT. CONFIDENCE: AVERAGE. && .MARINE... THE SCA WILL BE CONTINUED THRU 22/00Z. AFTER THAT CONFIDENCE IS MUCH LOWER SO IT WAS NOT EXTENDED ATTM. IF THERE NEEDS TO BE AN EXTENSION, IT WUD LIKELY BE FOR SEAS AS WIND SHUD BE BELOW CRITERIA. OTHERWISE, ONCE WE GET BEYOND THIS SCA, NO ADDITIONAL MARINE FLAGS ARE ANTICIPATED. OUTLOOK... MONDAY...SCA POSSIBLE IN THE MORNING FOR THE ATLC WATERS THEN NW WINDS SUBSIDE AFTERNOON/EVENING. CONFIDENCE: AVERAGE. TUESDAY...SCA SW WIND GUSTS POSSIBLE DURING THE AFTERNOON ALONG THE NEARSHORE WATERS. CONFIDENCE: AVERAGE. WEDNESDAY AND MOST OF THURSDAY...WINDS AND SEAS SHOULD STAY BELOW SCA CRITERIA. CONFIDENCE: AVERAGE. && .RIP CURRENTS... WITH A GUSTY WIND AND ELEVATED SEAS, GUID INDICATES THAT RIP CURRENT RISK WILL BE MODERATE TODAY. HOWEVER, ITS POSSIBLE THAT THE RISK MAY BE HIGHEST IN THE MRNG, BECAUSE AS THE WIND BECOMES MORE WLY AND NWLY AND THE WAVES ARE PUSHED AWAY FROM THE SHORE, THE RISK CUD LOWER AS THE SEAS DO. CONDS WILL BE FURTHER ASSESSED LATER TODAY. && .CLIMATE... VULNERABLE TO THE MAX TEMP WITHIN 2F OF EQUALING THE RECORD MAX TEMPERATURES FOR TUESDAY JUNE 23 KACY 98-1988 KILG 100-1894 KPHL 97-1888 KABE 95-1965 KTTN 97-1894 KRDG 96-1908 KMPO 90-1908 KGED 100-1988 RAINFALL: THE PAST WEEK FROM THE 14TH THROUGH 20TH "NOT INCLUDING TODAYS SO FAR". A GRAPHIC AND LINK WITH MORE DETAIL WILL POST ON OUR SOCIAL MEDIA FB PAGE AND WILL BE TWEETED. KMPO 2.07 7 CONSEC DAYS OF SOME RAIN KRDG 1.69 7 CONSEC DAYS OF SOME RAIN KABE 1.91 6 OF 7 DAYS IT RAINED KTTN 0.84 6 OF 7 DAYS IT RAINED KPHL 1.49 7 CONSEC DAYS OF RAIN KILG 2.70 7 CONSEC DAYS OF RAIN KACY 1.18 6 OF 7 DAYS IT RAINED KGED 1.06 6 OF 7 DAYS IT RAINED WHEN WE ADD TODAYS RAINFALL THROUGH 9 AM... IT WILL HAVE RAINED 8 CONSEC DAYS AT KMPO/KRDG/KPHL AND KILG AND 7 OF 8 ELSEWHERE. KILG: THE 9.18 INCHES FOR THE MONTH AS OF 845 AM THIS MORNING IS STILL 4TH WETTEST JUNE ON RECORD. 2013 13.66 2003 9.90 2006 9.40 2015 9.18 POR FOR THIS STATION IN JUNE IS BACK TO 1896. INTERESTINGLY, IN THE NEARLY 120 YEAR PERIOD OF RECORD, THE TOP 4 MONTHLY JUNE RAINFALL TOTALS ALL OCCURRED IN THE LAST 13 YEARS. TEMPS THROUGH THE 20TH ARE AVERAGING 1.3 TO 2.4 DEGREES ABOVE NORMAL THROUGHOUT THE CWA. && .EQUIPMENT... RTPPHI IS MISSING A FAIR AMOUNT OF DATA THIS MORNING DUE TO THE FAA MAINTENANCE PERIOD FROM 315Z-815Z OVERNIGHT. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ450>455. && $$ SYNOPSIS...DRAG/JOHNSON NEAR TERM...KLINE/NIERENBERG SHORT TERM...NIERENBERG LONG TERM...DRAG AVIATION...DRAG/KLINE/NIERENBERG MARINE...DRAG/NIERENBERG RIP CURRENTS... CLIMATE...DRAG EQUIPMENT...DRAG
AREA FORECAST DISCUSSION...UPDATED
NWS QUAD CITIES IA IL
656 AM CDT SUN JUN 21 2015 .UPDATE... ISSUED AT 650 AM CDT SUN JUN 21 2015 DENSE FOG HAS FORMED IN THE AREAS THAT THE MOST RAIN YESTERDAY ALONG WITH WHERE THE ANVIL FROM THE CONVECTION HAD MOVED OUT OF THE AREA. AS A RESULT A DENSE FOG ADVISORY IS IN EFFECT UNTIL 9AM TODAY. OTHERWISE DECAYING CONVECTION TO THE WEST MAY MAKE IT INTO THE AREA THIS AFTERNOON AS SPRINKLES OR LIGHT RAIN. THE HRRR HAS CONSISTENTLY FORECAST THIS. MY CONFIDENCE IS LOW IN THIS OCCURRING SO DECIDED TO LEAVE IT OUT. OTHERWISE NO UPDATES TO THE FORECAST WERE MADE. && .SYNOPSIS... ISSUED AT 327 AM CDT SUN JUN 21 2015 A MCS THAT MOVED THROUGH THE AREA ON SATURDAY EVENING HAD STALLED OUT JUST SOUTH OF THE CWA. MOST OF THE RAIN WAS OVER ACROSS THE AREA. 24 MPE SUGGESTS THAT THERE WERE 2 AREAS OF 1 TO 2 INCH RAINFALL ACROSS THE AREA TODAY. I80 WAS THE SEPARATION BETWEEN THESE TWO AREAS. DENSE FOG HAS DEVELOPED ACROSS THE THE NW ZONES AS LIGHT WIND AN AMPLE MOISTURE WAS LEADING TO FOG DEVELOPMENT. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 327 AM CDT SUN JUN 21 2015 MAIN FORECAST CONCERN FOR THE SHORT TERM FORECAST ARE THE CHANCES FOR POPS TONIGHT INTO MONDAY MORNING. OVERALL CHANCES APPEAR TO BE LOW FOR SCATTERED THUNDERSTORMS ON WHATEVER BOUNDARY DECIDES TO COALESCE AND MOVE NORTH AS A WARM FRONT OVERNIGHT. TODAY WILL BE A NICE DAY THAT WILL LEAD TO DRYING OUT ACROSS THE AREA. TEMPERATURES WILL BE WARM. THE BOUNDARY...OR LACK THERE OF...IS THE MAIN FORECAST PROBLEM. A PURELY MESOSCALE ISSUE PREDICTED BY SYNOPTIC MODELS USUALLY IS A DIFFICULT FORECAST. LOOKING AT MSAS THERE APPEARS TO BE DRIER AIR SINKING INTO THE AREA FROM THE NORTH. CONVECTION TO THE SOUTH OF US WILL LIKELY DIE OUT THIS MORNING LEAVING OFBS. THROUGH DIFFERENTIAL HEATING...THIS AREA SHOULD BE WHERE THE BOUNDARY SHOULD EXIST. A LOW PRESSURE....MOVING OUT OF SOUTH DAKOTA WILL FORCE THIS BOUNDARY NORTH OVERNIGHT. WE WILL RESIDE WELL INTO THE WARM SECTOR. HIRES MESO MODELS...SUGGEST LITTLE TO NO STORM COVERAGE OVERNIGHT TONIGHT. WENT WITH SCATTERED POPS...BUT DO BELIEVE IT MAY BE VERY ISOLATED OR NON-EXISTENT...JUST DO NOT HAVE THE CONFIDENCE TO GO THAT WAY YET. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 327 AM CDT SUN JUN 21 2015 SEASONABLY WARM WITH POTENTIALLY SIGNIFICANT RAINS MID WEEK AND THEN TURNING COOLER. LONG TERM FORECAST CONFIDENCE ASSESSMENT...FAIR OR AVERAGE OVERALL EXCEPT POOR WED/THU WITH WAVE AND TIMING AND PLACEMENT OF HEAVY RAINS DUE TO POOR PHYSICS ISSUES OF ALL SOLUTIONS. CONCEPTUAL TRENDS SUGGEST HEAVIEST PRECIPITATION WOULD TEND TO BE FURTHER SOUTH THAN MOST SOLUTIONS. OVERVIEW...INITIALIZATION AND VERIFICATION GOOD WITH AGAIN DISPLACED SOUTHWARD CONVECTION FROM SOLUTIONS NOTED THAT SUPPORTS THIS AS AN ONGOING CONCERN FOR MID WEEK DUE TO BL MOISTURE IMBALANCES AS IS COMMON. RUN TO RUN CONTINUITY SUPPORTS A 70/30 MIX OF GFS TO HI-RES ECMWF ON FORCING AND THEN TRY AND APPLY ECMWF RAIN PACKAGE. MONDAY AND MONDAY NIGHT...VERY WARM...BREEZY AND HUMID WITH HIGHS MOSTLY 85 TO 90 SUGGESTED WITH A CONCERN NORTH SECTIONS MAY BE COOLER FROM MCS NEAR OR JUST NORTH OF HIGHWAY 20 FOR LATER SHIFTS TO MONITOR SINCE TENDENCY IS FOR GUIDANCE SOLUTIONS TO DISPLACE RAINS TOO FAR NORTH. POPS IN NORTH MAY BE A BIT TOO LOW WITH POPS SOUTH OF I-80 MAY BE TOO HIGH BASED ON JET AXIS AND 850 PARAMETERS. TUESDAY AND TUESDAY NIGHT...WEAK HIGH PRESSURE TO RESULT IN A FAIR DAY AND MOSTLY DRY TO DRY AND LOWERED HIGH TEMPERATURES AND DEWPOINTS. LATER SHIFTS MAY NEED TO LOWER DEWPOINTS FURTHER IN NORTH SECTIONS. TUESDAY NIGHT...REGION FAVORED TO EXPERIENCE LATE AN MCS WITH HEAVIEST RAINS ALONG AND SOUTH OF HIGHWAY 34. POPS MAY NEED RAISING WHEN TIMING ISSUES ARE BETTER RESOLVED WITH 1+ INCH AMOUNTS SUGGESTED AND LOW TO MARGINAL RISK OF SEVERE. WEDNESDAY...LOTS OF CLOUDS AND PRECIPITATION WITH HEAVIEST PRECIPITATION TO BE ALONG AND ESPECIALLY SOUTH OF I-80. FORCING AND MOISTURE PROFILES FAVOR WIDESPREAD .5 TO 1.5+ AMOUNTS WITH LOCALLY 2 TO 3 INCHES THAT COMBINED WITH TUESDAY NIGHT EVENT COULD RESULT IN RENEWED HYDRO ISSUES. SEVERE RISK APPEARS WILL BE ALONG AND MAYBE SOUTH OF IA/MO BORDER. HIGH TEMPERATURES BASED ON THIS PATTERN MAY NEED LOWERING BY LATER SHIFTS BY UP TO 5 DEGREES. LOWS ALSO WITH EVAPORATIVE COOLING MAY NEED LOWERING. THURSDAY THROUGH SATURDAY...BECOMING COOLER AND LESS HUMID AND MOSTLY DRY TO DRY AS NORTHWEST FLOW PATTERN DEVELOPS. HIGHS MID 70S TO LOWER 80S AND MINS UPPER 50S TO LOWER 60S WITH MODERATE HUMIDITY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 605 AM CDT SUN JUN 21 2015 LIFR AND IFR CONDITIONS TO CONTINUE FOR THE NEXT COUPLE OF HOURS AT THE TAF SITES. WITH THE SUN RISING...EXPECT THESE ISSUES TO GO AWAY. AFTER THIS SITES SHOULD VFR THROUGH THE PERIOD. WINDS WILL BE LIGHT AND VARIABLE THEN SHIFT TO THE SOUTH NEAR MID EVENING. THERE IS A SLIGHT CHANCE FOR THUNDER TONIGHT...HOWEVER LOW CONFIDENCE PRECLUDES ANY MENTION IN THE TAF. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR BENTON- BUCHANAN-CEDAR-CLINTON-DELAWARE-DUBUQUE-IOWA-JACKSON- JEFFERSON-JOHNSON-JONES-KEOKUK-LINN-VAN BUREN-WASHINGTON. IL...DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR CARROLL-JO DAVIESS-STEPHENSON. MO...NONE. && $$ UPDATE...GIBBS SYNOPSIS...GIBBS SHORT TERM...GIBBS LONG TERM...NICHOLS AVIATION...GIBBS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
815 AM MDT SUN JUN 21 2015 .UPDATE... ISSUED AT 810 AM MDT SUN JUN 21 2015 JUST COMPLETED AN UPDATE. THIS WAS DONE MAINLY TO ADD THUNDERSTORMS TO THIS MORNING FOR THE NORTHEAST PORTION OF THE AREA DUE TO THE THUNDERSTORM COMPLEX MOVING OUT OF CENTRAL NEBRASKA. THIS COMPLEX HAS THROWN OUT AN OUTFLOW BOUNDARY AND HAS CAUSED ADDITIONAL CLOUD COVER TO DEVELOP. THE RUC HAS CAUGHT THIS GENERAL SCENARIO WELL WHICH KEEPS NORTHERLY WINDS AROUND INTO THE AFTERNOON. SO IN ADDITION TO THE PRECIPITATION INCREASED CLOUD COVER AND CHANGED THE WIND FIELD. DID LOWER THE TEMPERATURES A LITTLE ESPECIALLY IN THE NORTHEAST. HOWEVER AFTER THIS COMPLEX GOES PASSED...RUC DOES WANT TO SHIFT THE WINDS BACK TO A SOUTHERLY DIRECTION AND STILL BRING IN HOT TEMPERATURES. NOT SURE ABOUT THAT AND WILL WAIT/WATCH TO SEE WHAT HAPPENS THIS MORNING BEFORE MAKING FURTHER IF ANY ADJUSTMENTS. && .SHORT TERM...(TODAY THROUGH TUESDAY NIGHT) ISSUED AT 330 AM MDT SUN JUN 21 2015 TODAY-TONIGHT...FORECAST CONCERN IS THE HEAT. STATIONARY FRONT CURRENTLY TO THE SOUTH OF THE FORECAST AREA THIS MORNING WITH MUCH OF THE AREA UNDER EAST/NORTHEAST WINDS. NAM/RUC BOUNDARY LAYER RH INCREASE SIGNIFICANTLY ALONG/NORTH OF THE FRONT RESULTING IN AREAS OF FOG THROUGH MID MORNING. DURING THE AFTERNOON HOURS FRONT SLOWLY LIFTS NORTH WITH INCREASING SOUTHERLY WINDS BEHIND IT. A GENERALLY SUNNY SKY EXPECTED WITH AFTERNOON TEMPERATURES IN THE MID 90S TO AROUND 100 ALONG/NORTH OF THE INTERSTATE WITH UPPER 90S TO AROUND 103 SOUTH. LUCKILY NOT EXPECTING FULL MIXING AT 850MB WHICH BASED ON THE PAST 5 DAYS WOULD SUPPORT READINGS ABOUT 4F HIGHER AND PRODUCE SOME NEAR RECORD HIGHS. FOR TONIGHT WARM FRONT CONTINUES NORTH WITH BREEZY TO WINDY SOUTH WINDS THROUGH MIDNIGHT BEFORE VEERING TO THE SOUTHWEST LATE AHEAD OF AN APPROACHING FRONT. LOW TEMPERATURES IN THE LOW TO MID 60S IN FAR EASTERN COLORADO WITH MID 60S TO MID 70S EAST OF THE STATE LINE. HEAT INDEX VALUES MAY APPROACH 100 DEGREES IN THE HILL CITY AND GOVE AREAS...BELOW 105 THRESHOLD FOR HEAT ADVISORY. MONDAY-MONDAY NIGHT...BROAD 594-596DM HIGH PRESSURE CENTER EXTENDS FROM SOUTHERN KANSAS TO ARIZONA DURING THE DAY SLOWLY LIFTING NORTHWARD DURING THE NIGHT. NAM/GFS/SREF/ECMWF ALL SHOWING AN AREA OF INCREASING MID LEVEL MOISTURE LIFTING NORTHEAST INTO THE AREA DURING THE NIGHT...EXITING THE NORTHEAST CORNER OF THE AREA AROUND 12Z TUESDAY MORNING. NOSE OF MODEST LOW LEVEL JET FEEDING INTO THIS FEATURE AND ELEVATED CONVECTIVE INHIBITION LOW ENOUGH TO WARRANT A SLIGHT CHANCE AND LOW CHANCE OF THUNDERSTORMS. COLD FRONT MOVES TH