Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/24/12
SOUTHEAST ALASKA FORECAST DISCUSSION
NWS JUNEAU AK
357 PM AKDT MON JUL 23 2012
.SHORT TERM...A SIGNIFICANT MARINE LAYER PERSIST OVER THE GULF
OF ALASKA AND MOST OF SOUTHEAST ALASKA THROUGH THE SHORT TERM. A
WEAK COLD FRONT IN THE MID LEVELS OVER SOUTHEAST ALASKA AND ABOVE
THE MARINE LAYER...CONTINUES TO MOVE EAST AND WEAKEN. A SURFACE
RIDGE REBUILDS INTO THE EASTERN GULF THIS AFTERNOON THROUGH
TONIGHT THEN DROPS A BIT TO THE SOUTHEAST ON TUESDAY. A WEAK WARM
FRONT IN THE MID LEVELS OVER THE CENTRAL GULF WILL PUSH ACROSS
THE NORTHERN PANHANDLE TONIGHT. THIS IS FOLLOWED BY A WEAK COLD
FRONT ALOFT ON TUESDAY.
A FAIRLY DEEP MARINE LAYER...AROUND 6K FEET...IS KEEPING LOWER
LEVELS QUITE STABLE AND CAPPING OFF A MARINE LAYER OVER MUCH OF
THE AREA. ALONG THE COAST AND NEAR OCEAN ENTRANCES HAVE LOW CLOUDS
PERSISTING WELL INTO THE AFTERNOON. WEAK COLD FRONT ALOFT PASSING
OVER THIS INVERSION IS TRIGGERING AREAS OF DRIZZLE OR LIGHT RAIN
ACROSS NORTHERN PANHANDLE. BREAKS IN CLOUD COVER ACROSS SOUTHERN
AREAS THIS MORNING WILL FILL IN THROUGH THE AFTERNOON.
WILL KEEP RAIN AND DRIZZLE LIKELY FOR PAYA WESTWARD AND A CHANCE
OF LIGHT RAIN OR DRIZZLE ACROSS THE NORTHERN HALF OF SOUTHEAST
ALASKA AS A WEAK WARM FRONT ALOFT MOVES THROUGH TONIGHT AND A
CHANCE OF RAIN AGAIN ON TUESDAY AS A WEAK COLD FRONT ALOFT MOVES
THROUGH. KEPT PRECIP OUT OF SOUTHERN AREAS BUT WILL MENTION PATCHY
FOG LATE TONIGHT AND EARLY TUESDAY.
HAVE A LIGHT PRESSURE GRADIENT PATTERN ACROSS THE GULF AND
CENTRAL AREAS OF SOUTHEAST ALASKA THROUGH TUESDAY WITH NO
SIGNIFICANT WINDS. GRADIENT IS TIGHTENING UP A BIT ACROSS SOUTHERN
AREAS WITH WEST TO NORTHWEST WINDS INCREASING UP TO 20 KT THROUGH
THIS EVENING. AGAIN THERMAL GRADIENT BETWEEN COOL AND CLOUDY
SOUTHEAST ALASKA AND SUNNY WARMER CANADIAN INTERIOR IS FORECAST TO
DRIVE A SOUTH TO SOUTHWEST WIND THROUGH INTERIOR PASSES THIS
AFTERNOON ALTHOUGH HAVE BACKED OF ON SPEED A LITTLE WITH MUCH OF
THE GRADIENT ON CANADIAN SIDE OF MOUNTAINS (POSSIBLY DUE TO DEEPER
THAN USUAL MARINE LAYER ALLOWING SOME MARITIME AIR ON CANADIAN
SIDE OF MOUNTAINS?)
MAINLY USED NAM TO UPDATE GRIDS BUT DID ADD IN SOME GEM AND EC
FOR QPF AND FOUND AN HRRR AND BIAS CORRECTED GFS BLEND A GOOD
SOLUTION FOR RH/TD OVER GULF.
&&
.LONG TERM...THERE IS A WEAKENING DISTURBANCE DRIFTING SOUTHEAST
ACROSS THE GULF OF ALASKA WEDNESDAY AS A RIDGE AS POPS BACK OVER
NORTHERN GULF. ANOTHER WEAK SHORT WAVE/ FRONT SPREADS ACROSS THE
ALASKA PENINSULA TO THE WESTERN GULF BY FRIDAY MORNING. THIS
FEATURE WILL BE SPREAD ACROSS THE SOUTH CENTRAL GULF OF ALASKA.
FOR THE WEEKEND AND LONG RANGE TIME FRAME A LARGER SPREAD OF
SOLUTIONS ARE RESULTING IN FAIRLY DIFFERING WEATHER SOLUTIONS...
SO AM NOT MAKING SIGNIFICANT CHANGES TO THE LONG RANGE FORECAST
PATTERN.
FOR TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...ONLY DID MINOR
ADJUSTMENTS WITH A BLEND OF SEVERAL SOLUTIONS. WILL HAVE SOME
LIGHT RAIN TRYING TO SPREAD INTO THE PANHANDLE BUT FOR THE MOMENT
AM HOLDING THAT OFFSHORE.
FORECAST CONFIDENCE IS LOW FROM THURSDAY NIGHT ONWARD DUE TO
CONSISTENCY ISSUES.
.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ012.
&&
$$
MM/BEZENEK
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
250 PM MDT SUN JUL 22 2012
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 248 PM MDT SUN JUL 22 2012
RIDGE OVER THE GREAT PLAINS AND TROUGH OVER THE WEST COAST CONTNUE
TO ALLOW A MOIST SOUTHERLY FETCH OVER THE FORECAST AREA THROUGH
THE SHORT TERM PERIOD. A BIT MORE CLOUD COVER THIS MORNING HAS
DELAYED ONSET OF CONVECTION BUT AS CONDITIONS ARE STARTING TO
CLEAR OUT EARLY THIS AFTERNOON ACTIVITY HAS PULSED UP IN THE LAST
HOUR. RUC13 AND WV ARE SHOWING TWO POTENTIAL TRIGGERS IN THIS FLOW
THIS AFTERNOON. ONE IS OVER CENTRAL ARIZONA WHICH IS EXPECTED TO
MOVE EAST ACROSS THE FOUR CORNERS REGION BY LATE THIS AFTERNOON.
THE OTHER IS OVER SOUTHWESTERN COLORADO EARLY THIS AFTERNOON AND
IS EXPECTED TO MOVE SLOWLY NORTHEAST THIS AFTERNOON. THE MAIN
THREAT ONCE AGAIN WILL BE HEAVY RAIN WITH SOME ISOLATED FLASH
FLOODING POSSIBLE...ALONG WITH FREQUENT CLOUD TO RAIN LIGHTNING.
SHOWER AND THUNDERSTORM ACTIVITY WILL DECREASE AFTER MIDNIGHT. BY
MONDAY...PACIFIC NORTHWEST TROUGH WILL MOVE SLOWLY
EAST...OTHERWISE NOT MUCH CHANGE IN WEATHER PATTERN WITH ABUNDANT
MOISTURE IN PLACE...EXPECT ANOTHER ROUND OF SCATTERED TO NUMEROUS
AFTERNOON AND EVENING THUNDERSTORMS WITH THE POTENTIAL FOR HEAVY
RAIN.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 248 PM MDT SUN JUL 22 2012
UPPER CLOSED LOW OVER SRN ALBERTA WILL DRIFT SLOWLY EWRD TUESDAY...
FLATTENING THE RIDGE OF HIGH PRESSURE THAT HAS BEEN OVER OUR REGION.
THIS WILL ALSO USHER IN A WIND SHIFT TO THE NORTHWEST. SOME DYNAMIC
INSTABILITY WILL HELP TO GENERATE ANOTHER AFTERNOON OF WIDESPREAD
CONVECTION TUESDAY AFTERNOON. HOWEVER SIGNIFICANT DRYING ALOFT IS
SEEN FROM THE NORTHWEST TUESDAY NIGHT AND WEDNESDAY. THIS WILL
RESULT IN A NOTABLE DOWNTURN IN CONVECTION WEDNESDAY OVER MOST OF
THE CWA...EXCEPT NEAR AND ALONG THE CONTINENTAL DIVIDE WHERE A
LITTLE DEEPER MOISTURE WILL RESIDE. SHEAR PROFILE ALSO LOOKS LIKE IT
MAY BECOME A LITTLE MORE FAVORABLE FOR STRONGER STORM DEVELOPMENT IN
THAT AREA.
HIGH PRESSURE WILL START TO REBUILD OVER THE SRN GRT BASIN THURSDAY
HELPING HELPING TO SUPPRESS CONVECTION...BUT LOW LEVEL MOISTURE SHOULD
STILL BE IN PLACE FOR AT LEAST ISOLATED STORM DEVELOPMENT. THE NEXT
UPSTREAM TROF IN THE GULF OF ALASKA WILL APPROACH OUR PACIFIC COAST
FRIDAY WHICH WILL PUSH THE ABOVE MENTIONED HIGH PRESSURE CELL
EASTWARD...WHICH WILL THEN ALLOW A SOUTHWESTERLY FLOW TO REDEVELOP.
ACCOMPANYING THIS FLOW WILL BE ANOTHER SURGE OF SUB-TROPICAL
MOISTURE. THIS WILL BRING INCREASING CHANCES OF SHOWER AND
THUNDERSTORM DEVELOPMENT FRIDAY AFTERNOON THROUGH THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 248 PM MDT SUN JUL 22 2012
DIURNAL HEATING COMBINING WITH ABUNDANT SOUTHERLY FETCH OF MOISTURE
IS GENERATING ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS WHICH
WILL CONTINUE INTO THE EVENING HOURS ACROSS MUCH OF THE FORECAST
AREA. EXPECT SCATTERED TO NUMEROUS THUNDERSTORM COVERAGE BY LATE
THIS AFTERNOON WHICH WILL RESULT IN FREQUENT MOUNTAIN OBSCURATIONS AND
GUSTY OUTFLOW WINDS FROM 30 TO 40 MPH. REGIONAL AIRPORTS IN CLOSE
PROXIMITY TO HIGHER TERRAIN WILL SEE THE BEST CHANCE OF
THUNDERSTORM ACTIVITY FROM 22Z TO 03Z. THESE STORMS WILL BRING
BRIEF MVFR CIGS AND/OR VSBY IN HEAVY RAIN. SHOWER ACTIVITY WIL
DECREASE OVERNIGHT.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
SHORT TERM...MPM
LONG TERM...MC
AVIATION...TGJT
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1017 PM MDT SAT JUL 21 2012
.UPDATE...
ISSUED AT 1011 PM MDT SAT JUL 21 2012
MOST OF THE CONVECTION HAS MOVED NORTH OF I-70 AND SPREADING
ACROSS THE NORTHWEST PLATEAU ACROSS RIO BLANCO AND MOFFAT
COUNTIES. ONLY A FEW STRAY LIGHTNING STRIKES REMAIN. SOUTH OF I-70
SHOWERS AND TSTMS HAVE DECREASED SUBSTANTIALLY. HAVE TRENDED AREAL
COVERAGE DOWN QUICKLY ACROSS THE FORECAST AREA OVER THE NEXT 6 HOURS.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 247 PM MDT SAT JUL 21 2012
MOIST SUBTROPICAL FLOW WITH CONTINUE THROUGH THE WEEKEND. ATMOSPHERE
CONTINUES TO BE QUITE MOIST AS SHOWN BY THE GJT SOUNDING AND MODEL
SOLUTIONS. WATER VAPOR AND RUC13 PICKING UP A SHORT WAVE MOVING
NORTHWEST ACROSS UTAH THIS AFTERNOON WHICH WILL KEEP BEST FORCING
FROM THIS WAVE WEST OF THE CWA. HOWEVER...AS DIURNAL HEATING
INCREASES THIS AFTERNOON EXPECT CONVECTION TO INCREASE INTO THE
EVENING HOURS. IN ADDITION...RUC13 AND NAM12 ALSO SHOW INDICATIONS
OF ANOTHER SHORT WAVE WHICH WILL MOVE NORTH ACROSS SOUTHWESTERN
COLORADO THIS EVENING AND PRODUCE ADDITIONAL LIFT FOR THIS MOIST AND
UNSTABLE AIRMASS. SHOWERS AND THUNDERSTORM ACTIVITY WILL DECREASE
OVERNIGHT...BUT WOULD NOT RULE OUT SOME ADDITIONAL ACTIVITY DURING
THE EARLY MORNING HOURS. MODELS SHOW MORE OF THE SAME FOR SUNDAY AS
MOIST UNSTABLE SOUTHERLY FETCH CONTINUES OVER THE FORECAST AREA WITH
ANOTHER ROUND OF AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS...DECREASING OVERNIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 247 PM MDT SAT JUL 21 2012
A COUPLE OF MINOR CHANGES SEEN DURING THIS PERIOD...OTHERWISE VERY
LITTLE DIFFERENCE SEEN IN THE SENSIBLE WX PATTERN. HIGH PRESSURE
OVER THE PLAINS CONTINUES TO BE A FAVORABLE POSITION TO BRING A
STEADY STREAM OF MONSOONAL MOISTURE INTO THE SWRN U.S. INCLUDING ERN UT
AND WRN CO. IN THE MEANTIME A CLOSED UPPER LOW OVER THE PACIFIC NW
MOVES EWRD INTO SRN ALBERTA BY TUESDAY AFTERNOON. THIS FLATTENS
THE RIDGE SOME AND RESULTS IN THE UPPER LEVEL WINDS TRANSITIONING
FROM SWRLY TO NWRLY BY TUES AFTERNOON. BUT LIKE STATED ABOVE
LITTLE IF ANY IMPACT IS SEEN ON OUR SENSIBLE WX PATTERN. THIS HAS
BEEN HIGHLIGHTED BY AFTERNOON AND EVENING SHOWER AND THUNDERSTORM
FORMATION FOCUSED OVER THE HIGHER TERRAIN.
A SLIGHT DOWNTURN IN CONVECTION IS SEEN WED/THU AS A DRIER
NORTHWESTERLY FLOW INVADES THE REGION. HOWEVER IT IS QUICKLY
FOLLOWED BY THE NEXT SURGE OF SUBTROPICAL MOISTURE WHICH SHOULD
OCCUR FRIDAY AND SATURDAY AS THE FLOW SWITCHES BACK TO THE
SOUTHWEST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1011 PM MDT SAT JUL 21 2012
VFR CONDITIONS AREA EXPECTED OVERNIGHT AND THROUGH EARLY SUNDAY
AFTERNOON AT ALL TAF SITES. BY MID-AFTERNOON SUNDAY EXPECT
SCATTERED TO NUMEROUS SHOWERS AND TSTMS TO DEVELOP AGAIN...
PRODUCING LOCAL MVFR CIGS AND VSBY IN HEAVIER SHOWERS.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...CC
SHORT TERM...MPM
LONG TERM...MC
AVIATION...CC
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1159 PM EDT MON JUL 23 2012
.SYNOPSIS...
A STRONG COLD FRONT OVER THE GREAT LAKES WILL TRACK SOUTHEAST
INTO OUR AREA ON TUESDAY. THIS FRONT EVENTUALLY STALLS TO OUR
SOUTH ON WEDNESDAY AS HIGH PRESSURE BRIEFLY INFLUENCES OUR AREA.
ON THURSDAY INTO FRIDAY, A WARM FRONT WILL LIFT NORTHEAST THROUGH
THE REGION, FOLLOWED BY A COLD FRONT FROM THE WEST TRACKING ACROSS
THE MID ATLANTIC AROUND SATURDAY. A HIGH PRESSURE SYSTEM WILL THEN
BUILD INTO THE NORTHEAST ON SUNDAY AND MONDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
THE LINE OF CONVECTIVE LOOKING ELEMENTS APPROACHING THE DELAWARE
VALLEY HAS DIMINISHED...EVEN THOUGH THE AIRMASS IS STILL MARGINALLY
UNSTABLE. THE INSTABILITY APPEARS TO HAVE BECOME MORE ELEVATED...BASED
ON THE EXPANDING CLUTTER ON THE KDIX RADAR...AND THE PATCHY FOG
TRYING TO FORM HERE AT THE OFFICE (AND OTHER PLACES RAIN FELL).
THIS ACTIVITY WILL BE REMOVED FROM THE FORECAST WITH THE NEXT
UPDATE.
THE NEXT PROBLEM IS THE CONVECTION FORMING EAST OF LAKE ERIE...IN
THE POOL OF THE BEST AVAILABLE INSTABILITY. IT WOULD APPEAR THAT
MOST OF THE CONVECTIVE WOULD CONTINUE MOVING EAST IN THE WEST
NORTHWEST MID LEVEL FLOW...FOLLOWING THE BEST LOW TO MID LEVEL
THETA E. THE LATEST RUN OF THE HRRR KEEPS THE ACTIVITY OUT OF THE
AREA...AS DOES THE 0000 UTC NAM. THE CURRENT FORECAST CARRIES ONLY
A SLIGHT CHANCE FAR NORTH...AND THIS WILL BE RETAINED FOR NOW.
PATCHY FOG IS FORMING IN LOCATIONS WHERE IT RAINED...AND THE
MENTION OF PATCHY FOG WILL BE EXPANDED TO INCLUDE PORTIONS OF
CENTRAL NEW JERSEY AND THE LEHIGH VALLEY. NO SIGNIFICANT CHANGES
TO THE TEMPERATURES OR WINDS FOR THE OVERNIGHT.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
NORTHWEST FLOW ALOFT WILL LIKELY CARRY ANY SHORTWAVES AND TSTM
ACTIVITY AWAY FROM OUR CWA LATE TONIGHT AND TUE. DRIER BUT STILL
RATHER WARM AIR WILL BE ACROSS THE REGION TUESDAY. WE WILL JUST KEEP
LOW CHC POPS FOR A TSTM ACROSS THE AREA TUE WITH SOMEWHAT HIGHER CHC
ACROSS THE LOWER DELMARVA. HIGH TEMPERATURES TUE WILL BE MOSTLY IN
THE UPPER 80S TO LOW 90S...BUT SOME MID 90S MAY OCCUR OVER DELAWARE
AND THE MD ERN SHORE. HUMIDITY LEVELS WILL BE LESS THAN TODAY SO
HEAT INDEX VALUES WILL BE LOW ENOUGH TO PRECLUDE ANY HEAT HEADLINES
ATTM.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
WE HAVE SEEN SIMILAR INITIALIZATION WINNERS AGAIN TODAY WITH THE GFS
SLIGHTLY BETTER THAN THE WRF-NMMB AT 850MB (TEMPS AND DEWS) AND
925MB AND THE WRF-NMMB AT 500MB. SO THE GENERAL IDEAS OF THE
WRF-NMMB WERE FOLLOWED MORE WITH THE GFS THERMAL FIELDS USED FOR
SFC ADJUSTMENTS.
WE CONTINUED A LOW CHANCE EARLY FOR LEFTOVER TSTMS SOUTH. OTHERWISE,
CLEARING AND COOLER WEATHER IS FORECAST FOR TUESDAY NIGHT. BECAUSE
THE GRADIENT MIGHT BE SUFFICIENT, WE DID NOT LOWER THE MINS TO THE
DEW POINTS. STAT GUIDANCE OVERALL LOOKS REASONABLE.
WEDNESDAY STILL IS ON TAP TO BE "THE DAY" THIS WEEK WITH MOSTLY
SUNNY SKIES AND LOW HUMIDITY LEVELS. FCST 1000-850MB THICKNESSES AND
925MB TEMPS ARE STILL SUGGESTING A WARM DAY WITH MANY MAX TEMPS IN
THE MID TO UPPER 80S PRETTY MUCH IN LINE WITH CURRENT FCST AND STAT
GUIDANCE.
THE MODEL TREND BEYOND WEDNESDAY HAS BEEN TOWARD A FASTER RETURN OF
HOTTER AND MORE HUMID WEATHER AS WELL AS PRECIPITATION CHANCES. AN
ANOMALOUSLY STRONG LOW PRESSURE SYSTEM FOR JULY IS EXPECTED TO PASS
NORTH OF OUR CWA ON THURSDAY. WHILE THE GFS SOLUTION IS A VERY
ROBUST OUTLIER, THE GENERAL IDEA OF THE OTHER MODELS ARE THE
SAME. WE HAVE STARTED THE CHANCE OF WAA INDUCED PRECIPITATION IN
THE NORTHERN PART OF OUR CWA AFTER MIDNIGHT. ITS POSSIBLE THUNDER
MIGHT GET INVOLVED. BUT GIVEN THE GFS ROBUST SOLUTION IS THE
QUICKEST, WE OPTED TO LEAVE IT OUT FOR NOW. ITS ALSO POSSIBLE THAT
THE WAA INDUCED PCPN MIGHT STAY NORTH OF OUR CWA, BUT EVENTS LIKE
THIS TEND TO SEEP SOUTH MORE THAN THE MODELS THINK.
EVEN THROTTLING BACK THE GFS TO THE FOLD ON THURSDAY, IT SHOULD BE A
HOTTER AND MORE HUMID DAY WITH LEGITIMATE THUNDERSTORM CHANCES.
HIGHEST POPS ARE NORTH CLOSER PROXIMITY TO THE SURFACE LOW AND
FRONTAL BOUNDARY. MAX TEMPS WERE NUDGED UP SOUTH BASED ON SOME BREAK
IN THE CLOUDS. BECAUSE OF THE TREND, WE ARE EDGING CLOSER TO HEAT
CRITERIA FOR URBAN AREAS.
THEN FROM THURSDAY NIGHT INTO SATURDAY, THE FRONTAL BOUNDARY IS
EXPECTED TO REMAIN CLOSE TO OUR CWA. THIS PACKAGE CONTINUED TO LEAN
CLOSER TO THE HPC AND ECMWF SOLUTION THAN THE GFS PARTLY BECAUSE OF
CONTINUITY AND ALSO BECAUSE OF THE RECENT 12Z GFS RUN. THIS
SHOULD BE A RATHER UNSETTLED PERIOD WITH SCATTERED SHOWERS AND
THUNDERSTORMS AROUND UNTIL THE FRONT PASSES ABOUT SATURDAY.
ON SUNDAY, THE FRONTAL SYSTEM SHOULD BE MOVING OFFSHORE AND OUT TO
SEA. HOWEVER, THERE MAY BE SOME LINGERING SHOWERS, ESPECIALLY EARLY,
BEFORE THE MID-LEVEL TROUGH FULLY MOVES THROUGH. BY SUNDAY NIGHT
INTO MONDAY, HIGH PRESSURE AT THE SURFACE IS EXPECTED TO BUILD INTO
THE REGION, WHICH SHOULD PROVIDE DRY WEATHER. THE GFS INDICATES THAT
WE MAY GET SOME SHOWER ACTIVITY DEVELOP DURING THE DAY MONDAY, WHILE
THE ECMWF KEEPS IT DRY. SINCE IT`S PRETTY FAR OUT, WE WILL GO POP
LESS AT THIS TIME. WITH WEAK TROUGHING ACROSS THE NORTHEAST,
TEMPERATURES ARE EXPECTED TO BE RIGHT AROUND NORMAL FOR SUNDAY AND
MONDAY.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
WE CARRY MAINLY VFR TAFS, ALTHOUGH IN THE NORTHWEST WHERE RAIN
FELL WE ARE CARRYING SOME MVFR TO IFR VSBYS LATE TONIGHT. THE
CHANCE OF CONVECTION OVERNIGHT WAS NOT HIGH ENOUGH LATE THIS
EVENING TO CARRY IN THE TAFS.
TUE...MOSTLY SUNNY WITH A GUSTY W TO NW WINDS DEVELOPING. A FEW
SHOWERS POSSIBLE ESPECIALLY ACROSS THE DELMARVA.
OUTLOOK...
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...VFR CONDITIONS. C
THURSDAY...VFR CONDITIONS FOR THE MORNING. SCATTERED SHOWERS AND
TSTMS MAY PRODUCE SOME MVFR IN THE LATTER PART OF THE DAY.
THURSDAY NIGHT THROUGH FRIDAY...SHWR AND TSTM ACTIVITY
ASSOCIATED WITH A WARM FRONT IS EXPECTED TO YIELD MVFR OR EVEN IFR
FOR A TIME.
FRIDAY NIGHT AND SATURDAY...SOME MVFR TO IFR CONDITIONS POSSIBLE IN
FOG AND LOW CLOUDS FRIDAY NIGHT AND ANY SHOWERS AND TSTMS FRIDAY
NIGHT AND SATURDAY.
&&
.MARINE...
NO MARINE FLAGS WILL BE NEEDED TONIGHT, AND LIKELY NONE WILL BE
NEEDED ON TUE. SCT TSTMS WITH LOCAL HIGHER WINDS/SEAS ARE THE
PRIMARY HAZARDS IN THE SHORT TERM. SYNOPTIC WINDS MOSTLY S OR SW
TODAY THEN N OR NW TUESDAY. WIND SPEEDS MOSTLY 10 TO 15 KTS WITH A
FEW G20 THIS EVENING AND TUE.
OUTLOOK...
THERE IS A CHANCE FOR SMALL CRAFT ADVISORY CRITERIA ON TUESDAY NIGHT
ON THE OCEAN IN THE COOL AIR ADVECTION. EVEN IF IT WERE TO OCCUR,
THE DURATION IS LIKELY TO BE CONFINED TO JUST TUESDAY NIGHT. BEYOND
THAT WINDS AND SEAS SHOULD BE FURTHER AWAY FROM SMALL CRAFT ADVISORY
CRITERIA ON WEDNESDAY AS WEAKENING HIGH PRESSURE BUILDS INTO THE
COASTAL WATERS.
THE NEXT CHANCE FOR SMALL CRAFT ADVISORY CONDITIONS MAY COME ON
THURSDAY IN THE SOUTHWEST FLOW BETWEEN THE DEPARTING HIGH AND THE
APPROACHING LOW PRESSURE SYSTEM. BECAUSE THE GFS SOLUTION WAS SO
ROBUST, WE TOOK ABOUT 1 TO 2 FT OFF THE 12Z WAVE WATCH GUIDANCE AND
ARE NOT CONFIDENT ABOUT GRADIENT WIND GUSTS REACHING THE CRITERIA.
HIGHER CHANCE OVER THE OCEAN THAN THE BAY. WE WILL CONTINUE TO
MONITOR.
AFTER THURSDAY NIGHT, THE FRONTAL PROXIMITY SHOULD KEEP WINDS AND
SEAS BELOW CRITERIA AGAIN INTO SATURDAY WITH LOCAL CONDITIONS AROUND
THUNDERSTORMS AND POSSIBLY SOME FOG BEING THE LARGER MARINE
THREATS.
&&
.RIP CURRENTS...
THE IS A MODERATE RISK OF RIP CURRENTS FORECAST FOR TUESDAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GIGI/KLINE
NEAR TERM...HAYES
SHORT TERM...O`HARA
LONG TERM...GIGI/ROBERTSON
AVIATION...GIGI/KLINE/O`HARA
MARINE...GIGI/KLINE/O`HARA
RIP CURRENTS...DELISI
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
953 PM EDT MON JUL 23 2012
.SYNOPSIS...
A STRONG COLD FRONT OVER THE GREAT LAKES WILL TRACK SOUTHEAST
INTO OUR AREA ON TUESDAY. THIS FRONT EVENTUALLY STALLS TO OUR
SOUTH ON WEDNESDAY AS HIGH PRESSURE BRIEFLY INFLUENCES OUR AREA.
ON THURSDAY INTO FRIDAY, A WARM FRONT WILL LIFT NORTHEAST THROUGH
THE REGION, FOLLOWED BY A COLD FRONT FROM THE WEST TRACKING ACROSS
THE MID ATLANTIC AROUND SATURDAY. A HIGH PRESSURE SYSTEM WILL THEN
BUILD INTO THE NORTHEAST ON SUNDAY AND MONDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
SOME INSTABILITY STILL LINGERS AROUND THE AREA, BUT MODELS INDICATE
THE INSTABILITY MOSTLY WAS ALOFT. THUNDERSTORMS THAT MOVED ACROSS
THE FAR NORTHERN ZONES EARLIER HAD MADE THAT AREA MORE STABLE. AS
OF 0145Z, THERE WAS ONLY ISOLATED ACTIVITY AROUND.
INDICATIONS REGARDING ANOTHER ROUND OF CONVECTION LATER TONIGHT
WERE RATHER WEAK AS OF 0145Z. ACTIVITY THAT FORMED OVER LAKE ERIE
WHERE THERE MODELS SHOWED A CONFLUENCE OF H8 THETA E ADVECTION
AND Q-VECTOR CONVERGENCE HAD NOT YET BLOSSOMED INTO MORE THAN
SCATTERED ACTIVITY, AND THE LATEST HRRR RUN WIPED IT OUT
COMPLETELY BEFORE IT ENTERS OUR AREA. THE HRRR HAS BEEN
INCONSISTENT IN ITS HANDLING OF THE ACTIVITY TO THE NORTHWEST, SO
WE`VE ONLY TAKEN THE SOUTHERN ZONES OUT OF ANY POPS OVERNIGHT.
MIN TEMPERATURES WERE MASSAGED A LITTLE TO ACOUNT FOR THE RAKING
OF THE TEMPERATURES ACROSS THE NORTH THAT THE CONVECTION CAUSED.
WE ADDED PATCHY FOG WHERE SIGNIFICANT RAINFALL OCCURRED.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
NORTHWEST FLOW ALOFT WILL LIKELY CARRY ANY SHORTWAVES AND TSTM
ACTIVITY AWAY FROM OUR CWA LATE TONIGHT AND TUE. DRIER BUT STILL
RATHER WARM AIR WILL BE ACROSS THE REGION TUESDAY. WE WILL JUST KEEP
LOW CHC POPS FOR A TSTM ACROSS THE AREA TUE WITH SOMEWHAT HIGHER CHC
ACROSS THE LOWER DELMARVA. HIGH TEMPERATURES TUE WILL BE MOSTLY IN
THE UPPER 80S TO LOW 90S...BUT SOME MID 90S MAY OCCUR OVER DELAWARE
AND THE MD ERN SHORE. HUMIDITY LEVELS WILL BE LESS THAN TODAY SO
HEAT INDEX VALUES WILL BE LOW ENOUGH TO PRECLUDE ANY HEAT HEADLINES
ATTM.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
WE HAVE SEEN SIMILAR INITIALIZATION WINNERS AGAIN TODAY WITH THE GFS
SLIGHTLY BETTER THAN THE WRF-NMMB AT 850MB (TEMPS AND DEWS) AND
925MB AND THE WRF-NMMB AT 500MB. SO THE GENERAL IDEAS OF THE
WRF-NMMB WERE FOLLOWED MORE WITH THE GFS THERMAL FIELDS USED FOR
SFC ADJUSTMENTS.
WE CONTINUED A LOW CHANCE EARLY FOR LEFTOVER TSTMS SOUTH. OTHERWISE,
CLEARING AND COOLER WEATHER IS FORECAST FOR TUESDAY NIGHT. BECAUSE
THE GRADIENT MIGHT BE SUFFICIENT, WE DID NOT LOWER THE MINS TO THE
DEW POINTS. STAT GUIDANCE OVERALL LOOKS REASONABLE.
WEDNESDAY STILL IS ON TAP TO BE "THE DAY" THIS WEEK WITH MOSTLY
SUNNY SKIES AND LOW HUMIDITY LEVELS. FCST 1000-850MB THICKNESSES AND
925MB TEMPS ARE STILL SUGGESTING A WARM DAY WITH MANY MAX TEMPS IN
THE MID TO UPPER 80S PRETTY MUCH IN LINE WITH CURRENT FCST AND STAT
GUIDANCE.
THE MODEL TREND BEYOND WEDNESDAY HAS BEEN TOWARD A FASTER RETURN OF
HOTTER AND MORE HUMID WEATHER AS WELL AS PRECIPITATION CHANCES. AN
ANOMALOUSLY STRONG LOW PRESSURE SYSTEM FOR JULY IS EXPECTED TO PASS
NORTH OF OUR CWA ON THURSDAY. WHILE THE GFS SOLUTION IS A VERY
ROBUST OUTLIER, THE GENERAL IDEA OF THE OTHER MODELS ARE THE
SAME. WE HAVE STARTED THE CHANCE OF WAA INDUCED PRECIPITATION IN
THE NORTHERN PART OF OUR CWA AFTER MIDNIGHT. ITS POSSIBLE THUNDER
MIGHT GET INVOLVED. BUT GIVEN THE GFS ROBUST SOLUTION IS THE
QUICKEST, WE OPTED TO LEAVE IT OUT FOR NOW. ITS ALSO POSSIBLE THAT
THE WAA INDUCED PCPN MIGHT STAY NORTH OF OUR CWA, BUT EVENTS LIKE
THIS TEND TO SEEP SOUTH MORE THAN THE MODELS THINK.
EVEN THROTTLING BACK THE GFS TO THE FOLD ON THURSDAY, IT SHOULD BE A
HOTTER AND MORE HUMID DAY WITH LEGITIMATE THUNDERSTORM CHANCES.
HIGHEST POPS ARE NORTH CLOSER PROXIMITY TO THE SURFACE LOW AND
FRONTAL BOUNDARY. MAX TEMPS WERE NUDGED UP SOUTH BASED ON SOME BREAK
IN THE CLOUDS. BECAUSE OF THE TREND, WE ARE EDGING CLOSER TO HEAT
CRITERIA FOR URBAN AREAS.
THEN FROM THURSDAY NIGHT INTO SATURDAY, THE FRONTAL BOUNDARY IS
EXPECTED TO REMAIN CLOSE TO OUR CWA. THIS PACKAGE CONTINUED TO LEAN
CLOSER TO THE HPC AND ECMWF SOLUTION THAN THE GFS PARTLY BECAUSE OF
CONTINUITY AND ALSO BECAUSE OF THE RECENT 12Z GFS RUN. THIS
SHOULD BE A RATHER UNSETTLED PERIOD WITH SCATTERED SHOWERS AND
THUNDERSTORMS AROUND UNTIL THE FRONT PASSES ABOUT SATURDAY.
ON SUNDAY, THE FRONTAL SYSTEM SHOULD BE MOVING OFFSHORE AND OUT TO
SEA. HOWEVER, THERE MAY BE SOME LINGERING SHOWERS, ESPECIALLY EARLY,
BEFORE THE MID-LEVEL TROUGH FULLY MOVES THROUGH. BY SUNDAY NIGHT
INTO MONDAY, HIGH PRESSURE AT THE SURFACE IS EXPECTED TO BUILD INTO
THE REGION, WHICH SHOULD PROVIDE DRY WEATHER. THE GFS INDICATES THAT
WE MAY GET SOME SHOWER ACTIVITY DEVELOP DURING THE DAY MONDAY, WHILE
THE ECMWF KEEPS IT DRY. SINCE IT`S PRETTY FAR OUT, WE WILL GO POP
LESS AT THIS TIME. WITH WEAK TROUGHING ACROSS THE NORTHEAST,
TEMPERATURES ARE EXPECTED TO BE RIGHT AROUND NORMAL FOR SUNDAY AND
MONDAY.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
WE CARRY MAINLY VFR TAFS, ALTHOUGH IN THE NORTHWEST WHERE RAIN
FELL WE ARE CARRYING SOME MVFR TO IFR VSBYS LATE TONIGHT. THE
CHANCE OF CONVECTION OVERNIGHT WAS NOT HIGH ENOUGH LATE THIS
EVENING TO CARRY IN THE TAFS.
TUE...MOSTLY SUNNY WITH A GUSTY W TO NW WINDS DEVELOPING. A FEW
SHOWERS POSSIBLE ESPECIALLY ACROSS THE DELMARVA.
OUTLOOK...
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...VFR CONDITIONS. C
THURSDAY...VFR CONDITIONS FOR THE MORNING. SCATTERED SHOWERS AND
TSTMS MAY PRODUCE SOME MVFR IN THE LATTER PART OF THE DAY.
THURSDAY NIGHT THROUGH FRIDAY...SHWR AND TSTM ACTIVITY
ASSOCIATED WITH A WARM FRONT IS EXPECTED TO YIELD MVFR OR EVEN IFR
FOR A TIME.
FRIDAY NIGHT AND SATURDAY...SOME MVFR TO IFR CONDITIONS POSSIBLE IN
FOG AND LOW CLOUDS FRIDAY NIGHT AND ANY SHOWERS AND TSTMS FRIDAY
NIGHT AND SATURDAY.
&&
.MARINE...
NO MARINE FLAGS WILL BE NEEDED TONIGHT, AND LIKELY NONE WILL BE
NEEDED ON TUE. SCT TSTMS WITH LOCAL HIGHER WINDS/SEAS ARE THE
PRIMARY HAZARDS IN THE SHORT TERM. SYNOPTIC WINDS MOSTLY S OR SW
TODAY THEN N OR NW TUESDAY. WIND SPEEDS MOSTLY 10 TO 15 KTS WITH A
FEW G20 THIS EVENING AND TUE.
OUTLOOK...
THERE IS A CHANCE FOR SMALL CRAFT ADVISORY CRITERIA ON TUESDAY NIGHT
ON THE OCEAN IN THE COOL AIR ADVECTION. EVEN IF IT WERE TO OCCUR,
THE DURATION IS LIKELY TO BE CONFINED TO JUST TUESDAY NIGHT. BEYOND
THAT WINDS AND SEAS SHOULD BE FURTHER AWAY FROM SMALL CRAFT ADVISORY
CRITERIA ON WEDNESDAY AS WEAKENING HIGH PRESSURE BUILDS INTO THE
COASTAL WATERS.
THE NEXT CHANCE FOR SMALL CRAFT ADVISORY CONDITIONS MAY COME ON
THURSDAY IN THE SOUTHWEST FLOW BETWEEN THE DEPARTING HIGH AND THE
APPROACHING LOW PRESSURE SYSTEM. BECAUSE THE GFS SOLUTION WAS SO
ROBUST, WE TOOK ABOUT 1 TO 2 FT OFF THE 12Z WAVE WATCH GUIDANCE AND
ARE NOT CONFIDENT ABOUT GRADIENT WIND GUSTS REACHING THE CRITERIA.
HIGHER CHANCE OVER THE OCEAN THAN THE BAY. WE WILL CONTINUE TO
MONITOR.
AFTER THURSDAY NIGHT, THE FRONTAL PROXIMITY SHOULD KEEP WINDS AND
SEAS BELOW CRITERIA AGAIN INTO SATURDAY WITH LOCAL CONDITIONS AROUND
THUNDERSTORMS AND POSSIBLY SOME FOG BEING THE LARGER MARINE
THREATS.
&&
.RIP CURRENTS...
THE IS A MODERATE RISK OF RIP CURRENTS FORECAST FOR TUESDAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GIGI/KLINE
NEAR TERM...O`HARA/DELISI
SHORT TERM...O`HARA
LONG TERM...GIGI/ROBERTSON
AVIATION...GIGI/KLINE/O`HARA/DELISI
MARINE...GIGI/KLINE/O`HARA/DELISI
RIP CURRENTS...DELISI
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
746 PM EDT MON JUL 23 2012
.SYNOPSIS...
A STRONG COLD FRONT OVER THE GREAT LAKES WILL TRACK SOUTHEAST
INTO OUR AREA ON TUESDAY. THIS FRONT EVENTUALLY STALLS TO OUR
SOUTH ON WEDNESDAY AS HIGH PRESSURE BRIEFLY INFLUENCES OUR AREA.
ON THURSDAY INTO FRIDAY, A WARM FRONT WILL LIFT NORTHEAST THROUGH
THE REGION, FOLLOWED BY A COLD FRONT FROM THE WEST TRACKING ACROSS
THE MID ATLANTIC AROUND SATURDAY. A HIGH PRESSURE SYSTEM WILL THEN
BUILD INTO THE NORTHEAST ON SUNDAY AND MONDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
A SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL 11 PM FOR THE
NORTHERN AND CENTRAL PART OF THE CWA. THIS MAY BE REVISITED SOON.
INSTABILITY STILL LINGERS, BUT MODELS INDICATE THE INSTABILITY IS
INCREASINGLY ALOFT ESPECIALLY OVER THE SOUTHERN PART OF THE WATCH
AREA WHERE SHEAR ALSO IS WEAKER. INDICATIONS REGARDING ANOTHER
ROUND OF CONVECTION LATER TONIGHT WERE WEAK UNTIL 23Z, WHEN SOME
ACTIVITY BEGAN TO DEVELOP OVER WESTERN LAKE ERIE. THE HRRR HAS
ONLY A MODEST HANDLE ON THIS, AND ISOFAR AS IT TRACKS THE AREA OF
CONVECTION IT WEAKENS IT AS IT MOVES INTO OUR AREA.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
NORTHWEST FLOW ALOFT WILL LIKELY CARRY ANY SHORTWAVES AND TSTM
ACTIVITY AWAY FROM OUR CWA LATE TONIGHT AND TUE. DRIER BUT STILL
RATHER WARM AIR WILL BE ACROSS THE REGION TUESDAY. WE WILL JUST KEEP
LOW CHC POPS FOR A TSTM ACROSS THE AREA TUE WITH SOMEWHAT HIGHER CHC
ACROSS THE LOWER DELMARVA. HIGH TEMPERATURES TUE WILL BE MOSTLY IN
THE UPPER 80S TO LOW 90S...BUT SOME MID 90S MAY OCCUR OVER DELAWARE
AND THE MD ERN SHORE. HUMIDITY LEVELS WILL BE LESS THAN TODAY SO
HEAT INDEX VALUES WILL BE LOW ENOUGH TO PRECLUDE ANY HEAT HEADLINES
ATTM.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
WE HAVE SEEN SIMILAR INITIALIZATION WINNERS AGAIN TODAY WITH THE GFS
SLIGHTLY BETTER THAN THE WRF-NMMB AT 850MB (TEMPS AND DEWS) AND
925MB AND THE WRF-NMMB AT 500MB. SO THE GENERAL IDEAS OF THE
WRF-NMMB WERE FOLLOWED MORE WITH THE GFS THERMAL FIELDS USED FOR
SFC ADJUSTMENTS.
WE CONTINUED A LOW CHANCE EARLY FOR LEFTOVER TSTMS SOUTH. OTHERWISE,
CLEARING AND COOLER WEATHER IS FORECAST FOR TUESDAY NIGHT. BECAUSE
THE GRADIENT MIGHT BE SUFFICIENT, WE DID NOT LOWER THE MINS TO THE
DEW POINTS. STAT GUIDANCE OVERALL LOOKS REASONABLE.
WEDNESDAY STILL IS ON TAP TO BE "THE DAY" THIS WEEK WITH MOSTLY
SUNNY SKIES AND LOW HUMIDITY LEVELS. FCST 1000-850MB THICKNESSES AND
925MB TEMPS ARE STILL SUGGESTING A WARM DAY WITH MANY MAX TEMPS IN
THE MID TO UPPER 80S PRETTY MUCH IN LINE WITH CURRENT FCST AND STAT
GUIDANCE.
THE MODEL TREND BEYOND WEDNESDAY HAS BEEN TOWARD A FASTER RETURN OF
HOTTER AND MORE HUMID WEATHER AS WELL AS PRECIPITATION CHANCES. AN
ANOMALOUSLY STRONG LOW PRESSURE SYSTEM FOR JULY IS EXPECTED TO PASS
NORTH OF OUR CWA ON THURSDAY. WHILE THE GFS SOLUTION IS A VERY
ROBUST OUTLIER, THE GENERAL IDEA OF THE OTHER MODELS ARE THE
SAME. WE HAVE STARTED THE CHANCE OF WAA INDUCED PRECIPITATION IN
THE NORTHERN PART OF OUR CWA AFTER MIDNIGHT. ITS POSSIBLE THUNDER
MIGHT GET INVOLVED. BUT GIVEN THE GFS ROBUST SOLUTION IS THE
QUICKEST, WE OPTED TO LEAVE IT OUT FOR NOW. ITS ALSO POSSIBLE THAT
THE WAA INDUCED PCPN MIGHT STAY NORTH OF OUR CWA, BUT EVENTS LIKE
THIS TEND TO SEEP SOUTH MORE THAN THE MODELS THINK.
EVEN THROTTLING BACK THE GFS TO THE FOLD ON THURSDAY, IT SHOULD BE A
HOTTER AND MORE HUMID DAY WITH LEGITIMATE THUNDERSTORM CHANCES.
HIGHEST POPS ARE NORTH CLOSER PROXIMITY TO THE SURFACE LOW AND
FRONTAL BOUNDARY. MAX TEMPS WERE NUDGED UP SOUTH BASED ON SOME BREAK
IN THE CLOUDS. BECAUSE OF THE TREND, WE ARE EDGING CLOSER TO HEAT
CRITERIA FOR URBAN AREAS.
THEN FROM THURSDAY NIGHT INTO SATURDAY, THE FRONTAL BOUNDARY IS
EXPECTED TO REMAIN CLOSE TO OUR CWA. THIS PACKAGE CONTINUED TO LEAN
CLOSER TO THE HPC AND ECMWF SOLUTION THAN THE GFS PARTLY BECAUSE OF
CONTINUITY AND ALSO BECAUSE OF THE RECENT 12Z GFS RUN. THIS
SHOULD BE A RATHER UNSETTLED PERIOD WITH SCATTERED SHOWERS AND
THUNDERSTORMS AROUND UNTIL THE FRONT PASSES ABOUT SATURDAY.
ON SUNDAY, THE FRONTAL SYSTEM SHOULD BE MOVING OFFSHORE AND OUT TO
SEA. HOWEVER, THERE MAY BE SOME LINGERING SHOWERS, ESPECIALLY EARLY,
BEFORE THE MID-LEVEL TROUGH FULLY MOVES THROUGH. BY SUNDAY NIGHT
INTO MONDAY, HIGH PRESSURE AT THE SURFACE IS EXPECTED TO BUILD INTO
THE REGION, WHICH SHOULD PROVIDE DRY WEATHER. THE GFS INDICATES THAT
WE MAY GET SOME SHOWER ACTIVITY DEVELOP DURING THE DAY MONDAY, WHILE
THE ECMWF KEEPS IT DRY. SINCE IT`S PRETTY FAR OUT, WE WILL GO POP
LESS AT THIS TIME. WITH WEAK TROUGHING ACROSS THE NORTHEAST,
TEMPERATURES ARE EXPECTED TO BE RIGHT AROUND NORMAL FOR SUNDAY AND
MONDAY.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
MOSTLY VFR THE REST OF THE AFTERNOON AND EARLY TONIGHT WITH TSTM
ACTIVITY MOSTLY REMAINING NORTH OF OUR TAF SITES. AMDS WILL BE
ISSUED IF ACTIVITY MOVES TOWARD TTN-ABE-RDG. LATER TONIGHT...SOME
MVFR IN BR/HZ POSSIBLE WITH LIGHT WINDS AND P/C SKIES. TUE...MOSTLY
SUNNY WITH A GUSTY W TO NW WINDS DEVELOPING. A FEW SHOWERS POSSIBLE
ESPECIALLY ACROSS THE DELMARVA.
OUTLOOK...
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...VFR CONDITIONS. C
THURSDAY...VFR CONDITIONS FOR THE MORNING. SCATTERED SHOWERS AND
TSTMS MAY PRODUCE SOME MVFR IN THE LATTER PART OF THE DAY.
THURSDAY NIGHT THROUGH FRIDAY...SHWR AND TSTM ACTIVITY
ASSOCIATED WITH A WARM FRONT IS EXPECTED TO YIELD MVFR OR EVEN IFR
FOR A TIME.
FRIDAY NIGHT AND SATURDAY...SOME MVFR TO IFR CONDITIONS POSSIBLE IN
FOG AND LOW CLOUDS FRIDAY NIGHT AND ANY SHOWERS AND TSTMS FRIDAY
NIGHT AND SATURDAY.
&&
.MARINE...
NO MARINE FLAGS WILL BE NEEDED TONIGHT OR TUE. SCT TSTMS WITH
LOCAL HIGHER WINDS/SEAS ARE THE PRIMARY HAZARDS IN THE SHORT TERM.
SYNOPTIC WINDS MOSTLY S OR SW TODAY THEN N OR NW TUESDAY. WIND
SPEEDS MOSTLY 10 TO 15 KTS WITH A FEW G20 LATE TODAY AND TUE.
OUTLOOK...
THERE IS A CHANCE FOR SMALL CRAFT ADVISORY CRITERIA ON TUESDAY NIGHT
ON THE OCEAN IN THE COOL AIR ADVECTION. EVEN IF IT WERE TO OCCUR,
THE DURATION IS LIKELY TO BE CONFINED TO JUST TUESDAY NIGHT. BEYOND
THAT WINDS AND SEAS SHOULD BE FURTHER AWAY FROM SMALL CRAFT ADVISORY
CRITERIA ON WEDNESDAY AS WEAKENING HIGH PRESSURE BUILDS INTO THE
COASTAL WATERS.
THE NEXT CHANCE FOR SMALL CRAFT ADVISORY CONDITIONS MAY COME ON
THURSDAY IN THE SOUTHWEST FLOW BETWEEN THE DEPARTING HIGH AND THE
APPROACHING LOW PRESSURE SYSTEM. BECAUSE THE GFS SOLUTION WAS SO
ROBUST, WE TOOK ABOUT 1 TO 2 FT OFF THE 12Z WAVE WATCH GUIDANCE AND
ARE NOT CONFIDENT ABOUT GRADIENT WIND GUSTS REACHING THE CRITERIA.
HIGHER CHANCE OVER THE OCEAN THAN THE BAY. WE WILL CONTINUE TO
MONITOR.
AFTER THURSDAY NIGHT, THE FRONTAL PROXIMITY SHOULD KEEP WINDS AND
SEAS BELOW CRITERIA AGAIN INTO SATURDAY WITH LOCAL CONDITIONS AROUND
THUNDERSTORMS AND POSSIBLY SOME FOG BEING THE LARGER MARINE
THREATS.
&&
.RIP CURRENTS...
THERE IS A MODERATE RISK OF RIP CURRENTS FOR THE EVENING.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GIGI/KLINE
NEAR TERM...O`HARA/DELISI
SHORT TERM...O`HARA
LONG TERM...GIGI/ROBERTSON
AVIATION...GIGI/KLINE/O`HARA
MARINE...GIGI/KLINE/O`HARA
RIP CURRENTS...O`HARA
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1022 PM CDT MON JUL 23 2012
.DISCUSSION...
857 PM...EVENING UPDATE...EXTENSIVE MID/HIGH CLOUDS CONTINUE TO
SPREAD SOUTHEAST ACROSS THE AREA THIS EVENING WITH SOME SPRINKLES
AND A FEW LIGHT SHOWERS. HAVE SEEN VERY LITTLE CONVECTIVE
DEVELOPMENT AND THESE TRENDS APPEAR TO CONTINUE INTO THE EARLY
MORNING HRS AND WILL BE BACKING OFF TO JUST A SLIGHT CHANCE OF
SHOWERS FOR THE REST OF THIS EVENING. A STRONGER WAVE CURRENTLY
MOVING SOUTHEAST ACROSS MN AND NORTHWEST WI APPEARS TO HAVE A BIT
BETTER ORGANIZED AREA OF PRECIP WITH IT...BUT STILL RATHER MEAGER.
AS THIS CONTINUES TO THE SOUTHEAST OVERNIGHT...SHORT RANGE
GUIDANCE STILL SUGGESTS THAT ADDITIONAL SHOWERS AND THUNDERSTORMS
MAY DEVELOP ACROSS NORTHERN IL AND NORTHWEST INDIANA...GENERALLY
AFTER 08Z- 09Z. FOR THIS REASON...WILL HANG ONTO GOING LIKELY POPS
BUT CONFIDENCE REGARDING COVERAGE ARE LOW. RATHER IMPRESSIVE
PRECIPITABLE WATER VALUES AT OR SLIGHTLY ABOVE 2 INCHES TOWARD
DAYBREAK TUESDAY...THUS ANYTHING THAT DOES DEVELOP WILL CONTINUE
TO HAVE THE POTENTIAL TO PRODUCE LOCALLY HEAVY RAIN. ELSEWHERE...
THE COLD FRONT CONTINUES TO SLOWLY SAG SOUTH AND APPEARS TO HAVE
SLOWED FROM PREVIOUS TIMING. WOULD EXPECT SOME MOISTURE POOLING
AHEAD OF THE FRONT BUT DEWPOINTS ARE ALREADY IN THE MID TO EVEN A
FEW UPPER 70S ACROSS THE AREA. OVERNIGHT HRS WILL REMAIN QUITE
WARM AND MUGGY. CMS
//PREV DISCUSSION...
342 PM CDT
MAIN CONCERNS AND QUESTIONS REVOLVE AROUND CHANCES FOR SHOWERS AND
THUNDERSTORMS LATE THIS AFTERNOON INTO THE
EVENING...OVERNIGHT...AS WELL AS OVER THE NEXT SEVERAL DAYS WITH
SEVERE WEATHER AND HEAVY RAINFALL A CONCERN FOR EACH TIME FRAME.
IN THE NEAR TERM...SCATTERED MID AND HIGH LEVEL CLOUD COVER
CONTINUE TO SPILL SOUTHEAST ACROSS MUCH OF THE CWA. ALTHOUGH THERE
HAVE BEEN SOME BREAKS OBSERVED TODAY...THE MAJORITY OF THE DAY HAS
OBSERVED PARTLY CLOUDY TO PARTLY SUNNY SKIES. THIS CLOUD COVER HAS
LIMITED OVERALL TEMPS TODAY WITH MOST AREAS NOT QUITE RISING AS
HIGH AS PREVIOUSLY ANTICIPATED. WITH THE BREAKS...IT DIDNT TAKE
MUCH FOR SURFACE TEMPS TO RISE INTO THE MID 90S WITH SOME ISOLATED
UPPER 90S. THIS GENERAL TREND HAS BEEN GOOD WITH REGARD TO THE
HEAT AND HUMIDITY WHICH WAS EXPECTED TODAY...AS DEWPOINTS DID NOT
QUITE MIX OUT WITH MANY LOCATIONS ACROSS NORTHERN ILLINOIS
CURRENTLY OBSERVING LOW TO MID 70 DEWPOINTS. AREAS MAY OBSERVE
TEMPS RISE A COUPLE OF DEGREES OVER THE NEXT COUPLE OF
HOURS...BEFORE THICKER CLOUD COVER UPSTREAM ACROSS SOUTHWEST
WISCONSIN MOVES SOUTHEAST ACROSS THE CWA AND STIFLES ANY FURTHER
HEATING. WITH SEVERAL RIPPLES IN THE FLOW ALOFT SHIFTING OVERHEAD
TODAY...SCATTERED LIGHT SHOWERS HAVE BEEN OBSERVED ACROSS THE
SOUTHWEST PORTION OF THE CWA TODAY WITH SOME ISOLATED LIGHTNING
STRIKES OBSERVED. WITH A DECENT CAP IN PLACE AND CLOUD COVER
HELPING TO LIMIT LOW AND MID LEVEL LAPSE RATES...CONVECTION HAS
BEEN KEPT IN CHECK TODAY. ALTHOUGH...CONCERNS AND QUESTIONS STILL
REMAIN FOR LATE THIS AFTERNOON INTO THE EVENING. HAVE BEEN
MONITORING A STRONGER MID LEVEL FEATURE DROPPING SOUTHEAST ACROSS
SOUTHEAST MINNESOTA AND SOUTHWEST WISCONSIN WITH LATEST RADAR
IMAGERY SHOWING SOME RETURNS/SHOWERS MOVING INTO EASTERN IOWA. MY
CONCERNS WITH THESE SHOWERS ARE THAT UPSCALE GROWTH COULD OCCUR AS
THEY ENCOUNTER A DESTABILIZING ATMOSPHERE OVER NORTHERN ILLINOIS.
LATEST RUC ANALYSIS IS INDICATING THAT THE ATMOSPHERE IS
DESTABILIZING WITH CIN ERODING AND LOW LEVEL LAPSE RATES
STEEPENING. ALTHOUGH THIS IS PROBABLY OCCURRING...I WONDER IF THIS
LATEST ANALYSIS MIGHT BE OVERDONE. WHERE FAIRLY STEEP LAPSE RATES
OVERLAP THIS MID LEVEL WAVE/SHOWERS...LIGHTNING AND UPSCALE GROWTH
HAS BEEN NONEXISTENT. ALSO...AS MID AND HIGH LEVEL CLOUD COVER
CONTINUE TO MOVE OVERHEAD...NOT ANTICIPATING ANY REAL GOOD
DESTABILIZATION TO CONTINUE ACROSS THE AREA WITH WARM AIR ALOFT
REMAINING. SO DESPITE MY CONCERNS...A BETTER SOLUTION FOR THE NEAR
TERM INTO THE EVENING ARE THAT SHOWERS MOVE INTO NORTHERN ILLINOIS
WITH SOME FURTHER DEVELOPMENT AND ISOLATED STRONGER
DEVELOPMENT...BUT WITH THE PREVIOUSLY MENTIONED LIMITING FACTORS
HELPING TO ONCE AGAIN KEEP THE CONVECTION AND ANY SEVERE POTENTIAL
IN CHECK.
CONCERNS THEN SHIFT TOWARDS LATE TONIGHT INTO EARLY TUESDAY
MORNING. ANOTHER STRONGER AND MORE DEFINED MID LEVEL WAVE NOTED ON
LATEST WATER VAPOR IMAGERY ACROSS THE DAKOTAS WILL DROP SOUTHEAST
ACROSS THE REGION. THIS WAVE WILL ENCOUNTER A STRENGTHENING LOW
LEVEL JET ADVECTING A VERY MOIST AIR MASS INTO IT AND OVER A LOW
LEVEL BAROCLINIC ZONE DROPPING SOUTH THROUGH THE CWA...WITH
DEVELOPMENT EXPECTED ACROSS CENTRAL WISCONSIN. THIS WAVE/FORCING
AND STEERING FLOW WILL SHIFT THIS CLUSTER OF SHOWERS/THUNDERSTORMS
SOUTHEAST ACROSS NORTHERN ILLINOIS AND NORTHWEST INDIANA...WITH
THE BEST CHANCES EXPECTED NORTH OF LINE FROM DIXON IN ILLINOIS TO
FOWLER IN INDIANA AND THE BEST CHANCES WITH REGARDS TO TIMING
EXPECTED TO BE AFTER MIDNIGHT. AS THIS COMPLEX MOVES ACROSS THE
AREA IT WILL ENCOUNTER A VERY MOIST AND UNSTABLE ATMOSPHERE WITH
HIGH DEWPOINT/PWAT AIR IN PLACE. CONCERNS DURING THIS TIME FRAME
WOULD BE FOR SOME ISOLATED LARGE HAIL...BUT WITH CONCERNS MORE
TOWARD THE HEAVY RAIN POTENTIAL. ALTHOUGH THIS DOES NOT APPEAR TO
BE A CLASSIC HEAVY RAIN SETUP...MANY FEATURES ARE IN PLACE TO
PROVIDE SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS THAT WILL ALL
HAVE THE POTENTIAL TO PRODUCE HEAVY DOWNPOURS...INCLUDING LOW
LEVEL FLOW BRIEFLY ORIENTING ITSELF WITH REGARD TO THE BAROCLINIC
ZONE SUCH TO BRING AT LEAST SOME PERIOD OF POTENTIAL TRAINING OF
CELLS. WILL CONTINUE TO MAKE MENTION OF THESE THREATS IN THE HWO
AS WELL AS AN ESF.
RODRIGUEZ
THURSDAY THROUGH MONDAY...MEDIUM RANGE GUIDANCE IS IN PRETTY
DECENT AGREEMENT WITH THE MAIN FEATURES INTO EARLY NEXT WEEK.
SURFACE LOW PRESSURE WILL BE EXITING OFF TO THE EAST THURSDAY
MORNING WITH ITS TRAILING COLD FRONT SOMEWHERE NEAR THE AREA.
GUIDANCE DOES DIFFER ON HOW QUICKLY THE FRONT MOVES ACROSS THE
AREA THURSDAY. WILL KEEP POPS IN WITH THE BEST CHANCE DURING THE
MORNING BUT IT IS POSSIBLE THE FRONT COULD BE EXITING BY THAT
TIME. BEYOND THAT...A CLOSED UPPER LOW CURRENTLY SPINNING OVER
SOUTHERN BRITISH COLUMBIA WILL SLOWLY MOVE EASTWARD INTO UPPER
RIDGING OVER SASKATCHEWAN. BY THURSDAY MORNING...THE LOW WILL BE
IN THE VICINITY OF NORTHWEST MN/NORTHEAST NORTH DAKOTA HEADING
SOUTHEAST BRINGING A SURFACE LOW WITH IT. THIS WILL BEGIN TO
AFFECT THE AREA LATER THURSDAY NIGHT OR FRIDAY MORNING WITH
ANOTHER COOL FRONT DROPPING ACROSS THE AREA. AN UPPER TROUGH AXIS
LOOKS TO LAG THIS SYSTEM SO AT LEAST LOW PRECIP CHANCES WILL
LINGER INTO FRIDAY. SURFACE HIGH PRESSURE THEN ARRIVES INTO
SATURDAY MORNING AS UPPER RIDGING BECOMES RE-ESTABLISHED ACROSS
THE WESTERN U.S. A TROUGH MOVES THROUGH THE RIDGE SPAWNING SURFACE
LOW DEVELOPMENT ACROSS THE HIGH PLAINS LATER SATURDAY AND
SPREADING WARM ADVECTION EASTWARD ACROSS THE LOCAL AREA FOLLOWED
BY THE PASSAGE OF ANOTHER SURFACE LOW INTO MONDAY. THIS WHOLE
SYSTEM RESULTS IN CHANCES FOR SHOWERS AND STORMS FROM LATE SUNDAY
ON. TEMPS LOOK TO REMAIN MORE IN CHECK GIVEN PERIODIC CHANCES FOR
PRECIP...GENERALLY LOWER HEIGHTS OVER THE AREA AND OCCASIONAL
FRONTAL PASSAGES. DEPENDING ON FRONTAL TIMING THURSDAY...SOUTHERN
AREAS MAY REACH THE 90S...BUT OTHER THAN THAT WILL KEEP HIGHS IN
THE MID TO UPPER 80S FOR NOW.
MDB
&&
.CLIMATE...
400 AM CDT
RECORDS HIGHS FOR TODAY JULY 23RD ARE:
CHICAGO 99 /1914/
ROCKFORD 104 /1934/
RECORD WARM LOWS FOR TODAY JULY 23RD ARE:
CHICAGO 78 /1965/
ROCKFORD 76 /1965/
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* SHRA/TSRA TRENDS OVERNIGHT THROUGH TUESDAY MORNING.
* POTENTIAL FOR ADDITIONAL SHRA/TSRA TUESDAY AFTERNOON/NIGHT.
* WIND SHIFT FROM LIGHT WESTERLY TO NORTHEAST TOWARD DAYBREAK
TUESDAY.
RC
//DISCUSSION...UPDATED 00Z...
COMPLEX AND LOW CONFIDENCE FORECAST FOR THIS TAF CYCLE. GUIDANCE
HAS BEEN VERY MUCH OVERDONE ON SHRA AND TSRA THIS EVENING WITH
CURRENT MIDLEVEL WAVE SLIDING OVERHEAD. RELYING ON RADAR AND IR
SATELLITE TRENDS AND THE LACK OF LIGHTNING WITH ACTIVITY IN THE
REGION THERE IS NO GOOD REASON TO BELIEVE THE TRACON AREA WILL SEE
TSRA THIS EVENING. EVEN THE SHRA OVER WISCONSIN HAVE STRUGGLED
AGAINST THE CAPPED ATMOSPHERE DESPITE MESOANALYSIS SHOWING PLENTY
OF ELEVATED INSTABILITY. SO INTO THE OVERNIGHT HAVE GONE WITH A
VCSH MENTION IN THE TAFS...THOUGH THERE MAY BE A COUPLE
SHOWERS/SPRINKLES MOVING OVER THE TERMINALS FROM TIME TO TIME.
LATER OVERNIGHT INTO EARLY TUESDAY MORNING...A FRONTAL BOUNDARY
DRAPED ACROSS CENTRAL AND NORTHERN WISCONSIN WILL SAG SOUTH OVER
THE TERMINALS...AND ANOTHER MIDLEVEL SYSTEM MAY COMBINE TO RESULT
IN A BETTER CHANCE FOR PREVAILING SHRA/POSSIBLY TSRA. DO NOT HAVE
VERY HIGH CONFIDENCE...BUT INCLUDED VCTS WITH PREVAILING -SHRA FOR
THIS TIME PERIOD. IF ANY GOOD SHOWER ACTIVITY DOES GET
GOING...COULD SEE SOME LOWERING OF CEILINGS...BUT NOT EXPECTING A
DIP BELOW VFR. THERE MAY BE OPPORTUNITIES FOR MORE SHRA/TSRA TO
DEVELOP DURING THE DAY TUESDAY INTO TUESDAY NIGHT AS MORE MIDLEVEL
FEATURES DROP SOUTHEAST AND THE FRONT STALLS NEAR THE AREA.
HOWEVER...NOT NEARLY ENOUGH CONFIDENCE TO INCLUDE MENTION IN THIS
SET OF TAFS.
FOR WINDS...DUE TO SLOWER FRONTAL TIMING...HAVE SLOWED TIMING OF
WIND SHIFT TO EAST AND NORTHEAST AT THE TERMINALS. BEFORE THIS
OCCURS...WINDS SHOULD BE OUT OF THE WEST-SOUTHWEST AROUND OR LESS
THAN 10 KT...EVENTUALLY BECOMING WEST-NORTHWEST. THEN ON
TUESDAY...WINDS SHOULD STAY OUT OF THE EAST AND NORTHEAST WITH THE
FRONT SOUTH OF THE TERMINALS. ORD/MDW WILL LIKELY GO FROM
NORTHEAST TO MORE EASTERLY DURING THE DAY.
RC
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* MEDIUM/HIGH CONFIDENCE NO TSRA WILL IMPACT TERMINALS LATE THIS
EVENING THROUGH EARLY OVERNIGHT.
* MEDIUM CONFIDENCE IN SHRA/TSRA IN NORTHERN TRACON AREA TOWARD
DAYBREAK INTO TUESDAY MORNING...WITH LOW CONFIDENCE IN TSRA
DIRECTLY IMPACTING TERMINALS AND EXACT TIMING.
* LOW CONFIDENCE IN ANY TSRA TUESDAY AFTERNOON AND TUESDAY EVENING.
* LOW/MEDIUM CONFIDENCE IN TIMING OF WIND SHIFT...MEDIUM/HIGH
CONFIDENCE IN OVERALL WIND TRENDS.
RC
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY THROUGH FRIDAY...CHANCES FOR OCCASIONAL TSRA...OTHERWISE
VFR.
SATURDAY...VFR.
SUNDAY...CHANCE FOR TSRA...ESPECIALLY LATE. OTHERWISE VFR.
RC
&&
.MARINE...
300 PM CDT
RATHER ACTIVE FORECAST PERIOD LIES AHEAD WITH THE FIRST OF SEVERAL
LOWS AND FRONTS AFFECTING THE LAKE THIS AFTERNOON. SURFACE LOW
PRESSURE HAS MOVES INTO CENTRAL QUEBEC AND WILL LIFT NORTHEASTWARD
WHILE DEEPENING AS IT REACHES NEWFOUNDLAND TUESDAY MORNING/EARLY
AFTERNOON. THE COLD FRONT ASSOCIATED WITH THIS LOW IS MAKING
SOUTHEASTWARD PROGRESS AND RUNS FROM NEAR THE STRAITS OF MACKINAC
SOUTHEASTWARD TO NEAR MANITOWOC AT 2 PM CDT. WINDS WILL TURN
NORTHERLY AS THE FRONT PASSES THROUGH THE EVENING. IT APPEARS THAT
THERE MAY BE A BRIEF PERIOD OF STRONGER WINDS FROM NEAR THE MANITOU
ISLANDS NORTHWARD TO THE STRAITS EARLY THIS EVENING BEHIND THE FRONT
WITH 25 KT GUSTS POSSIBLE BEFORE SETTLING DOWN. A SIMILAR INCREASE
IN SPEEDS MAY OCCUR EARLY TONIGHT ACROSS THE SOUTHERN PART OF THE
LAKE BEHIND THE FRONT. HIGH PRESSURE WILL APPROACH TUESDAY ALLOWING
WINDS TO DIMINISH WITH A NORTHEASTERLY DIRECTION IN PLACE.
ATTENTION THEN TURNS TO LOW PRESSURE DEVELOPING ACROSS
THE CENTRAL/NORTHERN PLAINS INTO WEDNESDAY. THIS LOW LOOKS TO
REACH THE LAKE WEDNESDAY EVENING BUT THE STRENGTH IS SOMEWHAT IN
QUESTION. SOME MODEL GUIDANCE CONTINUES TO REALLY DEEPEN IN AS IT
CROSSES THE LAKE BUT THIS STILL LOOKS OVERDONE. DO EXPECT A LOW
WITH A PRESSURE OF AROUND 29.5 INCHES...THOUGH IT COULD BE
STRONGER...TO CROSS THE CENTRAL PART OF THE LAKE. SOUTH WINDS WILL
INCREASE AHEAD OF THE LOW ACROSS THE SOUTHERN HALF OF THE LAKE
WEDNESDAY MORNING WHILE EAST OR NORTHEAST WINDS WILL OCCUR NORTH.
DEPENDING ON THE STRENGTH OF THE LOW WIND SPEEDS MAY NEED TO BE
INCREASED OVER CURRENT FORECAST VALUES. SHOULD A MUCH DEEPER
SCENARIO PAN OUT...WHICH AGAIN LOOKS TO BE A RATHER LOW
PROBABILITY...THEN GALES COULD DEVELOP. THE LOW THEN CLEARS TO THE
EAST THURSDAY MORNING LEAVING A WEAK PRESSURE GRADIENT BEHIND IT
BUT AHEAD OF A WEAKER LOW WHICH WILL CROSS THE LAKE FRIDAY
MORNING. HIGH PRESSURE WILL GRADUALLY BUILD ON SATURDAY.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
857 PM CDT MON JUL 23 2012
.DISCUSSION...
857 PM...EVENING UPDATE...EXTENSIVE MID/HIGH CLOUDS CONTINUE TO
SPREAD SOUTHEAST ACROSS THE AREA THIS EVENING WITH SOME SPRINKLES
AND A FEW LIGHT SHOWERS. HAVE SEEN VERY LITTLE CONVECTIVE
DEVELOPMENT AND THESE TRENDS APPEAR TO CONTINUE INTO THE EARLY
MORNING HRS AND WILL BE BACKING OFF TO JUST A SLIGHT CHANCE OF
SHOWERS FOR THE REST OF THIS EVENING. A STRONGER WAVE CURRENTLY
MOVING SOUTHEAST ACROSS MN AND NORTHWEST WI APPEARS TO HAVE A BIT
BETTER ORGANIZED AREA OF PRECIP WITH IT...BUT STILL RATHER MEAGER.
AS THIS CONTINUES TO THE SOUTHEAST OVERNIGHT...SHORT RANGE
GUIDANCE STILL SUGGESTS THAT ADDITIONAL SHOWERS AND THUNDERSTORMS
MAY DEVELOP ACROSS NORTHERN IL AND NORTHWEST INDIANA...GENERALLY
AFTER 08Z- 09Z. FOR THIS REASON...WILL HANG ONTO GOING LIKELY POPS
BUT CONFIDENCE REGARDING COVERAGE ARE LOW. RATHER IMPRESSIVE
PRECIPITABLE WATER VALUES AT OR SLIGHTLY ABOVE 2 INCHES TOWARD
DAYBREAK TUESDAY...THUS ANYTHING THAT DOES DEVELOP WILL CONTINUE
TO HAVE THE POTENTIAL TO PRODUCE LOCALLY HEAVY RAIN. ELSEWHERE...
THE COLD FRONT CONTINUES TO SLOWLY SAG SOUTH AND APPEARS TO HAVE
SLOWED FROM PREVIOUS TIMING. WOULD EXPECT SOME MOISTURE POOLING
AHEAD OF THE FRONT BUT DEWPOINTS ARE ALREADY IN THE MID TO EVEN A
FEW UPPER 70S ACROSS THE AREA. OVERNIGHT HRS WILL REMAIN QUITE
WARM AND MUGGY. CMS
&&
.PREV DISCUSSION...
342 PM CDT
MAIN CONCERNS AND QUESTIONS REVOLVE AROUND CHANCES FOR SHOWERS AND
THUNDERSTORMS LATE THIS AFTERNOON INTO THE
EVENING...OVERNIGHT...AS WELL AS OVER THE NEXT SEVERAL DAYS WITH
SEVERE WEATHER AND HEAVY RAINFALL A CONCERN FOR EACH TIME FRAME.
IN THE NEAR TERM...SCATTERED MID AND HIGH LEVEL CLOUD COVER
CONTINUE TO SPILL SOUTHEAST ACROSS MUCH OF THE CWA. ALTHOUGH THERE
HAVE BEEN SOME BREAKS OBSERVED TODAY...THE MAJORITY OF THE DAY HAS
OBSERVED PARTLY CLOUDY TO PARTLY SUNNY SKIES. THIS CLOUD COVER HAS
LIMITED OVERALL TEMPS TODAY WITH MOST AREAS NOT QUITE RISING AS
HIGH AS PREVIOUSLY ANTICIPATED. WITH THE BREAKS...IT DIDNT TAKE
MUCH FOR SURFACE TEMPS TO RISE INTO THE MID 90S WITH SOME ISOLATED
UPPER 90S. THIS GENERAL TREND HAS BEEN GOOD WITH REGARD TO THE
HEAT AND HUMIDITY WHICH WAS EXPECTED TODAY...AS DEWPOINTS DID NOT
QUITE MIX OUT WITH MANY LOCATIONS ACROSS NORTHERN ILLINOIS
CURRENTLY OBSERVING LOW TO MID 70 DEWPOINTS. AREAS MAY OBSERVE
TEMPS RISE A COUPLE OF DEGREES OVER THE NEXT COUPLE OF
HOURS...BEFORE THICKER CLOUD COVER UPSTREAM ACROSS SOUTHWEST
WISCONSIN MOVES SOUTHEAST ACROSS THE CWA AND STIFLES ANY FURTHER
HEATING. WITH SEVERAL RIPPLES IN THE FLOW ALOFT SHIFTING OVERHEAD
TODAY...SCATTERED LIGHT SHOWERS HAVE BEEN OBSERVED ACROSS THE
SOUTHWEST PORTION OF THE CWA TODAY WITH SOME ISOLATED LIGHTNING
STRIKES OBSERVED. WITH A DECENT CAP IN PLACE AND CLOUD COVER
HELPING TO LIMIT LOW AND MID LEVEL LAPSE RATES...CONVECTION HAS
BEEN KEPT IN CHECK TODAY. ALTHOUGH...CONCERNS AND QUESTIONS STILL
REMAIN FOR LATE THIS AFTERNOON INTO THE EVENING. HAVE BEEN
MONITORING A STRONGER MID LEVEL FEATURE DROPPING SOUTHEAST ACROSS
SOUTHEAST MINNESOTA AND SOUTHWEST WISCONSIN WITH LATEST RADAR
IMAGERY SHOWING SOME RETURNS/SHOWERS MOVING INTO EASTERN IOWA. MY
CONCERNS WITH THESE SHOWERS ARE THAT UPSCALE GROWTH COULD OCCUR AS
THEY ENCOUNTER A DESTABILIZING ATMOSPHERE OVER NORTHERN ILLINOIS.
LATEST RUC ANALYSIS IS INDICATING THAT THE ATMOSPHERE IS
DESTABILIZING WITH CIN ERODING AND LOW LEVEL LAPSE RATES
STEEPENING. ALTHOUGH THIS IS PROBABLY OCCURRING...I WONDER IF THIS
LATEST ANALYSIS MIGHT BE OVERDONE. WHERE FAIRLY STEEP LAPSE RATES
OVERLAP THIS MID LEVEL WAVE/SHOWERS...LIGHTNING AND UPSCALE GROWTH
HAS BEEN NONEXISTENT. ALSO...AS MID AND HIGH LEVEL CLOUD COVER
CONTINUE TO MOVE OVERHEAD...NOT ANTICIPATING ANY REAL GOOD
DESTABILIZATION TO CONTINUE ACROSS THE AREA WITH WARM AIR ALOFT
REMAINING. SO DESPITE MY CONCERNS...A BETTER SOLUTION FOR THE NEAR
TERM INTO THE EVENING ARE THAT SHOWERS MOVE INTO NORTHERN ILLINOIS
WITH SOME FURTHER DEVELOPMENT AND ISOLATED STRONGER
DEVELOPMENT...BUT WITH THE PREVIOUSLY MENTIONED LIMITING FACTORS
HELPING TO ONCE AGAIN KEEP THE CONVECTION AND ANY SEVERE POTENTIAL
IN CHECK.
CONCERNS THEN SHIFT TOWARDS LATE TONIGHT INTO EARLY TUESDAY
MORNING. ANOTHER STRONGER AND MORE DEFINED MID LEVEL WAVE NOTED ON
LATEST WATER VAPOR IMAGERY ACROSS THE DAKOTAS WILL DROP SOUTHEAST
ACROSS THE REGION. THIS WAVE WILL ENCOUNTER A STRENGTHENING LOW
LEVEL JET ADVECTING A VERY MOIST AIR MASS INTO IT AND OVER A LOW
LEVEL BAROCLINIC ZONE DROPPING SOUTH THROUGH THE CWA...WITH
DEVELOPMENT EXPECTED ACROSS CENTRAL WISCONSIN. THIS WAVE/FORCING
AND STEERING FLOW WILL SHIFT THIS CLUSTER OF SHOWERS/THUNDERSTORMS
SOUTHEAST ACROSS NORTHERN ILLINOIS AND NORTHWEST INDIANA...WITH
THE BEST CHANCES EXPECTED NORTH OF LINE FROM DIXON IN ILLINOIS TO
FOWLER IN INDIANA AND THE BEST CHANCES WITH REGARDS TO TIMING
EXPECTED TO BE AFTER MIDNIGHT. AS THIS COMPLEX MOVES ACROSS THE
AREA IT WILL ENCOUNTER A VERY MOIST AND UNSTABLE ATMOSPHERE WITH
HIGH DEWPOINT/PWAT AIR IN PLACE. CONCERNS DURING THIS TIME FRAME
WOULD BE FOR SOME ISOLATED LARGE HAIL...BUT WITH CONCERNS MORE
TOWARD THE HEAVY RAIN POTENTIAL. ALTHOUGH THIS DOES NOT APPEAR TO
BE A CLASSIC HEAVY RAIN SETUP...MANY FEATURES ARE IN PLACE TO
PROVIDE SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS THAT WILL ALL
HAVE THE POTENTIAL TO PRODUCE HEAVY DOWNPOURS...INCLUDING LOW
LEVEL FLOW BRIEFLY ORIENTING ITSELF WITH REGARD TO THE BAROCLINIC
ZONE SUCH TO BRING AT LEAST SOME PERIOD OF POTENTIAL TRAINING OF
CELLS. WILL CONTINUE TO MAKE MENTION OF THESE THREATS IN THE HWO
AS WELL AS AN ESF.
RODRIGUEZ
THURSDAY THROUGH MONDAY...MEDIUM RANGE GUIDANCE IS IN PRETTY
DECENT AGREEMENT WITH THE MAIN FEATURES INTO EARLY NEXT WEEK.
SURFACE LOW PRESSURE WILL BE EXITING OFF TO THE EAST THURSDAY
MORNING WITH ITS TRAILING COLD FRONT SOMEWHERE NEAR THE AREA.
GUIDANCE DOES DIFFER ON HOW QUICKLY THE FRONT MOVES ACROSS THE
AREA THURSDAY. WILL KEEP POPS IN WITH THE BEST CHANCE DURING THE
MORNING BUT IT IS POSSIBLE THE FRONT COULD BE EXITING BY THAT
TIME. BEYOND THAT...A CLOSED UPPER LOW CURRENTLY SPINNING OVER
SOUTHERN BRITISH COLUMBIA WILL SLOWLY MOVE EASTWARD INTO UPPER
RIDGING OVER SASKATCHEWAN. BY THURSDAY MORNING...THE LOW WILL BE
IN THE VICINITY OF NORTHWEST MN/NORTHEAST NORTH DAKOTA HEADING
SOUTHEAST BRINGING A SURFACE LOW WITH IT. THIS WILL BEGIN TO
AFFECT THE AREA LATER THURSDAY NIGHT OR FRIDAY MORNING WITH
ANOTHER COOL FRONT DROPPING ACROSS THE AREA. AN UPPER TROUGH AXIS
LOOKS TO LAG THIS SYSTEM SO AT LEAST LOW PRECIP CHANCES WILL
LINGER INTO FRIDAY. SURFACE HIGH PRESSURE THEN ARRIVES INTO
SATURDAY MORNING AS UPPER RIDGING BECOMES RE-ESTABLISHED ACROSS
THE WESTERN U.S. A TROUGH MOVES THROUGH THE RIDGE SPAWNING SURFACE
LOW DEVELOPMENT ACROSS THE HIGH PLAINS LATER SATURDAY AND
SPREADING WARM ADVECTION EASTWARD ACROSS THE LOCAL AREA FOLLOWED
BY THE PASSAGE OF ANOTHER SURFACE LOW INTO MONDAY. THIS WHOLE
SYSTEM RESULTS IN CHANCES FOR SHOWERS AND STORMS FROM LATE SUNDAY
ON. TEMPS LOOK TO REMAIN MORE IN CHECK GIVEN PERIODIC CHANCES FOR
PRECIP...GENERALLY LOWER HEIGHTS OVER THE AREA AND OCCASIONAL
FRONTAL PASSAGES. DEPENDING ON FRONTAL TIMING THURSDAY...SOUTHERN
AREAS MAY REACH THE 90S...BUT OTHER THAN THAT WILL KEEP HIGHS IN
THE MID TO UPPER 80S FOR NOW.
MDB
&&
.CLIMATE...
400 AM CDT
RECORDS HIGHS FOR TODAY JULY 23RD ARE:
CHICAGO 99 /1914/
ROCKFORD 104 /1934/
RECORD WARM LOWS FOR TODAY JULY 23RD ARE:
CHICAGO 78 /1965/
ROCKFORD 76 /1965/
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* SHRA/TSRA TRENDS TONIGHT THROUGH TUESDAY.
* WIND SHIFT FROM WESTERLY TO NORTHEAST TOWARD DAYBREAK TUESDAY.
RC
//DISCUSSION...UPDATED 00Z...
COMPLEX AND LOW CONFIDENCE FORECAST FOR THIS TAF CYCLE. GUIDANCE
HAS BEEN VERY MUCH OVERDONE ON SHRA AND TSRA THIS EVENING WITH
CURRENT MIDLEVEL WAVE SLIDING OVERHEAD. RELYING ON RADAR AND IR
SATELLITE TRENDS AND THE LACK OF LIGHTNING WITH ACTIVITY IN THE
REGION THERE IS NO GOOD REASON TO BELIEVE THE TRACON AREA WILL SEE
TSRA THIS EVENING. EVEN THE SHRA OVER WISCONSIN HAVE STRUGGLED
AGAINST THE CAPPED ATMOSPHERE DESPITE MESOANALYSIS SHOWING PLENTY
OF ELEVATED INSTABILITY. SO INTO THE OVERNIGHT HAVE GONE WITH A
VCSH MENTION IN THE TAFS...THOUGH THERE MAY BE A COUPLE
SHOWERS/SPRINKLES MOVING OVER THE TERMINALS FROM TIME TO TIME.
LATER OVERNIGHT INTO EARLY TUESDAY MORNING...A FRONTAL BOUNDARY
DRAPED ACROSS CENTRAL AND NORTHERN WISCONSIN WILL SAG SOUTH OVER
THE TERMINALS...AND ANOTHER MIDLEVEL SYSTEM MAY COMBINE TO RESULT
IN A BETTER CHANCE FOR PREVAILING SHRA/POSSIBLY TSRA. DO NOT HAVE
VERY HIGH CONFIDENCE...BUT INCLUDED VCTS WITH PREVAILING -SHRA FOR
THIS TIME PERIOD. IF ANY GOOD SHOWER ACTIVITY DOES GET
GOING...COULD SEE SOME LOWERING OF CEILINGS...BUT NOT EXPECTING A
DIP BELOW VFR. THERE MAY BE OPPORTUNITIES FOR MORE SHRA/TSRA TO
DEVELOP DURING THE DAY TUESDAY INTO TUESDAY NIGHT AS MORE MIDLEVEL
FEATURES DROP SOUTHEAST AND THE FRONT STALLS NEAR THE AREA.
HOWEVER...NOT NEARLY ENOUGH CONFIDENCE TO INCLUDE MENTION IN THIS
SET OF TAFS.
FOR WINDS...DUE TO SLOWER FRONTAL TIMING...HAVE SLOWED TIMING OF
WIND SHIFT TO EAST AND NORTHEAST AT THE TERMINALS. BEFORE THIS
OCCURS...WINDS SHOULD BE OUT OF THE WEST-SOUTHWEST AROUND OR LESS
THAN 10 KT...EVENTUALLY BECOMING WEST-NORTHWEST. THEN ON
TUESDAY...WINDS SHOULD STAY OUT OF THE EAST AND NORTHEAST WITH THE
FRONT SOUTH OF THE TERMINALS. ORD/MDW WILL LIKELY GO FROM
NORTHEAST TO MORE EASTERLY DURING THE DAY.
RC
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* MEDIUM/HIGH CONFIDENCE NO TSRA WILL IMPACT TERMINALS THIS
EVENING INTO EARLY OVERNIGHT.
* LOW CONFIDENCE IN SHRA/TSRA TRENDS LATE OVERNIGHT INTO EARLY
TUESDAY.
* LOW CONFIDENCE IN ANY TSRA TUESDAY AFTERNOON AND TUESDAY EVENING.
* LOW/MEDIUM CONFIDENCE IN TIMING OF WIND SHIFT...MEDIUM/HIGH
CONFIDENCE IN OVERALL WIND TRENDS.
RC
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY THROUGH FRIDAY...CHANCES FOR OCCASIONAL TSRA...OTHERWISE
VFR.
SATURDAY...VFR.
SUNDAY...CHANCE FOR TSRA...ESPECIALLY LATE. OTHERWISE VFR.
RC
&&
.MARINE...
300 PM CDT
RATHER ACTIVE FORECAST PERIOD LIES AHEAD WITH THE FIRST OF SEVERAL
LOWS AND FRONTS AFFECTING THE LAKE THIS AFTERNOON. SURFACE LOW
PRESSURE HAS MOVES INTO CENTRAL QUEBEC AND WILL LIFT NORTHEASTWARD
WHILE DEEPENING AS IT REACHES NEWFOUNDLAND TUESDAY MORNING/EARLY
AFTERNOON. THE COLD FRONT ASSOCIATED WITH THIS LOW IS MAKING
SOUTHEASTWARD PROGRESS AND RUNS FROM NEAR THE STRAITS OF MACKINAC
SOUTHEASTWARD TO NEAR MANITOWOC AT 2 PM CDT. WINDS WILL TURN
NORTHERLY AS THE FRONT PASSES THROUGH THE EVENING. IT APPEARS THAT
THERE MAY BE A BRIEF PERIOD OF STRONGER WINDS FROM NEAR THE MANITOU
ISLANDS NORTHWARD TO THE STRAITS EARLY THIS EVENING BEHIND THE FRONT
WITH 25 KT GUSTS POSSIBLE BEFORE SETTLING DOWN. A SIMILAR INCREASE
IN SPEEDS MAY OCCUR EARLY TONIGHT ACROSS THE SOUTHERN PART OF THE
LAKE BEHIND THE FRONT. HIGH PRESSURE WILL APPROACH TUESDAY ALLOWING
WINDS TO DIMINISH WITH A NORTHEASTERLY DIRECTION IN PLACE.
ATTENTION THEN TURNS TO LOW PRESSURE DEVELOPING ACROSS
THE CENTRAL/NORTHERN PLAINS INTO WEDNESDAY. THIS LOW LOOKS TO
REACH THE LAKE WEDNESDAY EVENING BUT THE STRENGTH IS SOMEWHAT IN
QUESTION. SOME MODEL GUIDANCE CONTINUES TO REALLY DEEPEN IN AS IT
CROSSES THE LAKE BUT THIS STILL LOOKS OVERDONE. DO EXPECT A LOW
WITH A PRESSURE OF AROUND 29.5 INCHES...THOUGH IT COULD BE
STRONGER...TO CROSS THE CENTRAL PART OF THE LAKE. SOUTH WINDS WILL
INCREASE AHEAD OF THE LOW ACROSS THE SOUTHERN HALF OF THE LAKE
WEDNESDAY MORNING WHILE EAST OR NORTHEAST WINDS WILL OCCUR NORTH.
DEPENDING ON THE STRENGTH OF THE LOW WIND SPEEDS MAY NEED TO BE
INCREASED OVER CURRENT FORECAST VALUES. SHOULD A MUCH DEEPER
SCENARIO PAN OUT...WHICH AGAIN LOOKS TO BE A RATHER LOW
PROBABILITY...THEN GALES COULD DEVELOP. THE LOW THEN CLEARS TO THE
EAST THURSDAY MORNING LEAVING A WEAK PRESSURE GRADIENT BEHIND IT
BUT AHEAD OF A WEAKER LOW WHICH WILL CROSS THE LAKE FRIDAY
MORNING. HIGH PRESSURE WILL GRADUALLY BUILD ON SATURDAY.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
719 PM CDT MON JUL 23 2012
.DISCUSSION...
342 PM CDT
MAIN CONCERNS AND QUESTIONS REVOLVE AROUND CHANCES FOR SHOWERS AND
THUNDERSTORMS LATE THIS AFTERNOON INTO THE
EVENING...OVERNIGHT...AS WELL AS OVER THE NEXT SEVERAL DAYS WITH
SEVERE WEATHER AND HEAVY RAINFALL A CONCERN FOR EACH TIME FRAME.
IN THE NEAR TERM...SCATTERED MID AND HIGH LEVEL CLOUD COVER
CONTINUE TO SPILL SOUTHEAST ACROSS MUCH OF THE CWA. ALTHOUGH THERE
HAVE BEEN SOME BREAKS OBSERVED TODAY...THE MAJORITY OF THE DAY HAS
OBSERVED PARTLY CLOUDY TO PARTLY SUNNY SKIES. THIS CLOUD COVER HAS
LIMITED OVERALL TEMPS TODAY WITH MOST AREAS NOT QUITE RISING AS
HIGH AS PREVIOUSLY ANTICIPATED. WITH THE BREAKS...IT DIDNT TAKE
MUCH FOR SURFACE TEMPS TO RISE INTO THE MID 90S WITH SOME ISOLATED
UPPER 90S. THIS GENERAL TREND HAS BEEN GOOD WITH REGARD TO THE
HEAT AND HUMIDITY WHICH WAS EXPECTED TODAY...AS DEWPOINTS DID NOT
QUITE MIX OUT WITH MANY LOCATIONS ACROSS NORTHERN ILLINOIS
CURRENTLY OBSERVING LOW TO MID 70 DEWPOINTS. AREAS MAY OBSERVE
TEMPS RISE A COUPLE OF DEGREES OVER THE NEXT COUPLE OF
HOURS...BEFORE THICKER CLOUD COVER UPSTREAM ACROSS SOUTHWEST
WISCONSIN MOVES SOUTHEAST ACROSS THE CWA AND STIFLES ANY FURTHER
HEATING. WITH SEVERAL RIPPLES IN THE FLOW ALOFT SHIFTING OVERHEAD
TODAY...SCATTERED LIGHT SHOWERS HAVE BEEN OBSERVED ACROSS THE
SOUTHWEST PORTION OF THE CWA TODAY WITH SOME ISOLATED LIGHTNING
STRIKES OBSERVED. WITH A DECENT CAP IN PLACE AND CLOUD COVER
HELPING TO LIMIT LOW AND MID LEVEL LAPSE RATES...CONVECTION HAS
BEEN KEPT IN CHECK TODAY. ALTHOUGH...CONCERNS AND QUESTIONS STILL
REMAIN FOR LATE THIS AFTERNOON INTO THE EVENING. HAVE BEEN
MONITORING A STRONGER MID LEVEL FEATURE DROPPING SOUTHEAST ACROSS
SOUTHEAST MINNESOTA AND SOUTHWEST WISCONSIN WITH LATEST RADAR
IMAGERY SHOWING SOME RETURNS/SHOWERS MOVING INTO EASTERN IOWA. MY
CONCERNS WITH THESE SHOWERS ARE THAT UPSCALE GROWTH COULD OCCUR AS
THEY ENCOUNTER A DESTABILIZING ATMOSPHERE OVER NORTHERN ILLINOIS.
LATEST RUC ANALYSIS IS INDICATING THAT THE ATMOSPHERE IS
DESTABILIZING WITH CIN ERODING AND LOW LEVEL LAPSE RATES
STEEPENING. ALTHOUGH THIS IS PROBABLY OCCURRING...I WONDER IF THIS
LATEST ANALYSIS MIGHT BE OVERDONE. WHERE FAIRLY STEEP LAPSE RATES
OVERLAP THIS MID LEVEL WAVE/SHOWERS...LIGHTNING AND UPSCALE GROWTH
HAS BEEN NONEXISTENT. ALSO...AS MID AND HIGH LEVEL CLOUD COVER
CONTINUE TO MOVE OVERHEAD...NOT ANTICIPATING ANY REAL GOOD
DESTABILIZATION TO CONTINUE ACROSS THE AREA WITH WARM AIR ALOFT
REMAINING. SO DESPITE MY CONCERNS...A BETTER SOLUTION FOR THE NEAR
TERM INTO THE EVENING ARE THAT SHOWERS MOVE INTO NORTHERN ILLINOIS
WITH SOME FURTHER DEVELOPMENT AND ISOLATED STRONGER
DEVELOPMENT...BUT WITH THE PREVIOUSLY MENTIONED LIMITING FACTORS
HELPING TO ONCE AGAIN KEEP THE CONVECTION AND ANY SEVERE POTENTIAL
IN CHECK.
CONCERNS THEN SHIFT TOWARDS LATE TONIGHT INTO EARLY TUESDAY
MORNING. ANOTHER STRONGER AND MORE DEFINED MID LEVEL WAVE NOTED ON
LATEST WATER VAPOR IMAGERY ACROSS THE DAKOTAS WILL DROP SOUTHEAST
ACROSS THE REGION. THIS WAVE WILL ENCOUNTER A STRENGTHENING LOW
LEVEL JET ADVECTING A VERY MOIST AIR MASS INTO IT AND OVER A LOW
LEVEL BAROCLINIC ZONE DROPPING SOUTH THROUGH THE CWA...WITH
DEVELOPMENT EXPECTED ACROSS CENTRAL WISCONSIN. THIS WAVE/FORCING
AND STEERING FLOW WILL SHIFT THIS CLUSTER OF SHOWERS/THUNDERSTORMS
SOUTHEAST ACROSS NORTHERN ILLINOIS AND NORTHWEST INDIANA...WITH
THE BEST CHANCES EXPECTED NORTH OF LINE FROM DIXON IN ILLINOIS TO
FOWLER IN INDIANA AND THE BEST CHANCES WITH REGARDS TO TIMING
EXPECTED TO BE AFTER MIDNIGHT. AS THIS COMPLEX MOVES ACROSS THE
AREA IT WILL ENCOUNTER A VERY MOIST AND UNSTABLE ATMOSPHERE WITH
HIGH DEWPOINT/PWAT AIR IN PLACE. CONCERNS DURING THIS TIME FRAME
WOULD BE FOR SOME ISOLATED LARGE HAIL...BUT WITH CONCERNS MORE
TOWARD THE HEAVY RAIN POTENTIAL. ALTHOUGH THIS DOES NOT APPEAR TO
BE A CLASSIC HEAVY RAIN SETUP...MANY FEATURES ARE IN PLACE TO
PROVIDE SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS THAT WILL ALL
HAVE THE POTENTIAL TO PRODUCE HEAVY DOWNPOURS...INCLUDING LOW
LEVEL FLOW BRIEFLY ORIENTING ITSELF WITH REGARD TO THE BAROCLINIC
ZONE SUCH TO BRING AT LEAST SOME PERIOD OF POTENTIAL TRAINING OF
CELLS. WILL CONTINUE TO MAKE MENTION OF THESE THREATS IN THE HWO
AS WELL AS AN ESF.
RODRIGUEZ
THURSDAY THROUGH MONDAY...MEDIUM RANGE GUIDANCE IS IN PRETTY
DECENT AGREEMENT WITH THE MAIN FEATURES INTO EARLY NEXT WEEK.
SURFACE LOW PRESSURE WILL BE EXITING OFF TO THE EAST THURSDAY
MORNING WITH ITS TRAILING COLD FRONT SOMEWHERE NEAR THE AREA.
GUIDANCE DOES DIFFER ON HOW QUICKLY THE FRONT MOVES ACROSS THE
AREA THURSDAY. WILL KEEP POPS IN WITH THE BEST CHANCE DURING THE
MORNING BUT IT IS POSSIBLE THE FRONT COULD BE EXITING BY THAT
TIME. BEYOND THAT...A CLOSED UPPER LOW CURRENTLY SPINNING OVER
SOUTHERN BRITISH COLUMBIA WILL SLOWLY MOVE EASTWARD INTO UPPER
RIDGING OVER SASKATCHEWAN. BY THURSDAY MORNING...THE LOW WILL BE
IN THE VICINITY OF NORTHWEST MN/NORTHEAST NORTH DAKOTA HEADING
SOUTHEAST BRINGING A SURFACE LOW WITH IT. THIS WILL BEGIN TO
AFFECT THE AREA LATER THURSDAY NIGHT OR FRIDAY MORNING WITH
ANOTHER COOL FRONT DROPPING ACROSS THE AREA. AN UPPER TROUGH AXIS
LOOKS TO LAG THIS SYSTEM SO AT LEAST LOW PRECIP CHANCES WILL
LINGER INTO FRIDAY. SURFACE HIGH PRESSURE THEN ARRIVES INTO
SATURDAY MORNING AS UPPER RIDGING BECOMES RE-ESTABLISHED ACROSS
THE WESTERN U.S. A TROUGH MOVES THROUGH THE RIDGE SPAWNING SURFACE
LOW DEVELOPMENT ACROSS THE HIGH PLAINS LATER SATURDAY AND
SPREADING WARM ADVECTION EASTWARD ACROSS THE LOCAL AREA FOLLOWED
BY THE PASSAGE OF ANOTHER SURFACE LOW INTO MONDAY. THIS WHOLE
SYSTEM RESULTS IN CHANCES FOR SHOWERS AND STORMS FROM LATE SUNDAY
ON. TEMPS LOOK TO REMAIN MORE IN CHECK GIVEN PERIODIC CHANCES FOR
PRECIP...GENERALLY LOWER HEIGHTS OVER THE AREA AND OCCASIONAL
FRONTAL PASSAGES. DEPENDING ON FRONTAL TIMING THURSDAY...SOUTHERN
AREAS MAY REACH THE 90S...BUT OTHER THAN THAT WILL KEEP HIGHS IN
THE MID TO UPPER 80S FOR NOW.
MDB
&&
.CLIMATE...
400 AM CDT
RECORDS HIGHS FOR TODAY JULY 23RD ARE:
CHICAGO 99 /1914/
ROCKFORD 104 /1934/
RECORD WARM LOWS FOR TODAY JULY 23RD ARE:
CHICAGO 78 /1965/
ROCKFORD 76 /1965/
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* SHRA/TSRA TRENDS TONIGHT THROUGH TUESDAY.
* WIND SHIFT FROM WESTERLY TO NORTHEAST TOWARD DAYBREAK TUESDAY.
RC
//DISCUSSION...UPDATED 00Z...
COMPLEX AND LOW CONFIDENCE FORECAST FOR THIS TAF CYCLE. GUIDANCE
HAS BEEN VERY MUCH OVERDONE ON SHRA AND TSRA THIS EVENING WITH
CURRENT MIDLEVEL WAVE SLIDING OVERHEAD. RELYING ON RADAR AND IR
SATELLITE TRENDS AND THE LACK OF LIGHTNING WITH ACTIVITY IN THE
REGION THERE IS NO GOOD REASON TO BELIEVE THE TRACON AREA WILL SEE
TSRA THIS EVENING. EVEN THE SHRA OVER WISCONSIN HAVE STRUGGLED
AGAINST THE CAPPED ATMOSPHERE DESPITE MESOANALYSIS SHOWING PLENTY
OF ELEVATED INSTABILITY. SO INTO THE OVERNIGHT HAVE GONE WITH A
VCSH MENTION IN THE TAFS...THOUGH THERE MAY BE A COUPLE
SHOWERS/SPRINKLES MOVING OVER THE TERMINALS FROM TIME TO TIME.
LATER OVERNIGHT INTO EARLY TUESDAY MORNING...A FRONTAL BOUNDARY
DRAPED ACROSS CENTRAL AND NORTHERN WISCONSIN WILL SAG SOUTH OVER
THE TERMINALS...AND ANOTHER MIDLEVEL SYSTEM MAY COMBINE TO RESULT
IN A BETTER CHANCE FOR PREVAILING SHRA/POSSIBLY TSRA. DO NOT HAVE
VERY HIGH CONFIDENCE...BUT INCLUDED VCTS WITH PREVAILING -SHRA FOR
THIS TIME PERIOD. IF ANY GOOD SHOWER ACTIVITY DOES GET
GOING...COULD SEE SOME LOWERING OF CEILINGS...BUT NOT EXPECTING A
DIP BELOW VFR. THERE MAY BE OPPORTUNITIES FOR MORE SHRA/TSRA TO
DEVELOP DURING THE DAY TUESDAY INTO TUESDAY NIGHT AS MORE MIDLEVEL
FEATURES DROP SOUTHEAST AND THE FRONT STALLS NEAR THE AREA.
HOWEVER...NOT NEARLY ENOUGH CONFIDENCE TO INCLUDE MENTION IN THIS
SET OF TAFS.
FOR WINDS...DUE TO SLOWER FRONTAL TIMING...HAVE SLOWED TIMING OF
WIND SHIFT TO EAST AND NORTHEAST AT THE TERMINALS. BEFORE THIS
OCCURS...WINDS SHOULD BE OUT OF THE WEST-SOUTHWEST AROUND OR LESS
THAN 10 KT...EVENTUALLY BECOMING WEST-NORTHWEST. THEN ON
TUESDAY...WINDS SHOULD STAY OUT OF THE EAST AND NORTHEAST WITH THE
FRONT SOUTH OF THE TERMINALS. ORD/MDW WILL LIKELY GO FROM
NORTHEAST TO MORE EASTERLY DURING THE DAY.
RC
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* MEDIUM/HIGH CONFIDENCE NO TSRA WILL IMPACT TERMINALS THIS
EVENING INTO EARLY OVERNIGHT.
* LOW CONFIDENCE IN SHRA/TSRA TRENDS LATE OVERNIGHT INTO EARLY
TUESDAY.
* LOW CONFIDENCE IN ANY TSRA TUESDAY AFTERNOON AND TUESDAY EVENING.
* LOW/MEDIUM CONFIDENCE IN TIMING OF WIND SHIFT...MEDIUM/HIGH
CONFIDENCE IN OVERALL WIND TRENDS.
RC
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY THROUGH FRIDAY...CHANCES FOR OCCASIONAL TSRA...OTHERWISE
VFR.
SATURDAY...VFR.
SUNDAY...CHANCE FOR TSRA...ESPECIALLY LATE. OTHERWISE VFR.
RC
&&
.MARINE...
300 PM CDT
RATHER ACTIVE FORECAST PERIOD LIES AHEAD WITH THE FIRST OF SEVERAL
LOWS AND FRONTS AFFECTING THE LAKE THIS AFTERNOON. SURFACE LOW
PRESSURE HAS MOVES INTO CENTRAL QUEBEC AND WILL LIFT NORTHEASTWARD
WHILE DEEPENING AS IT REACHES NEWFOUNDLAND TUESDAY MORNING/EARLY
AFTERNOON. THE COLD FRONT ASSOCIATED WITH THIS LOW IS MAKING
SOUTHEASTWARD PROGRESS AND RUNS FROM NEAR THE STRAITS OF MACKINAC
SOUTHEASTWARD TO NEAR MANITOWOC AT 2 PM CDT. WINDS WILL TURN
NORTHERLY AS THE FRONT PASSES THROUGH THE EVENING. IT APPEARS THAT
THERE MAY BE A BRIEF PERIOD OF STRONGER WINDS FROM NEAR THE MANITOU
ISLANDS NORTHWARD TO THE STRAITS EARLY THIS EVENING BEHIND THE FRONT
WITH 25 KT GUSTS POSSIBLE BEFORE SETTLING DOWN. A SIMILAR INCREASE
IN SPEEDS MAY OCCUR EARLY TONIGHT ACROSS THE SOUTHERN PART OF THE
LAKE BEHIND THE FRONT. HIGH PRESSURE WILL APPROACH TUESDAY ALLOWING
WINDS TO DIMINISH WITH A NORTHEASTERLY DIRECTION IN PLACE.
ATTENTION THEN TURNS TO LOW PRESSURE DEVELOPING ACROSS
THE CENTRAL/NORTHERN PLAINS INTO WEDNESDAY. THIS LOW LOOKS TO
REACH THE LAKE WEDNESDAY EVENING BUT THE STRENGTH IS SOMEWHAT IN
QUESTION. SOME MODEL GUIDANCE CONTINUES TO REALLY DEEPEN IN AS IT
CROSSES THE LAKE BUT THIS STILL LOOKS OVERDONE. DO EXPECT A LOW
WITH A PRESSURE OF AROUND 29.5 INCHES...THOUGH IT COULD BE
STRONGER...TO CROSS THE CENTRAL PART OF THE LAKE. SOUTH WINDS WILL
INCREASE AHEAD OF THE LOW ACROSS THE SOUTHERN HALF OF THE LAKE
WEDNESDAY MORNING WHILE EAST OR NORTHEAST WINDS WILL OCCUR NORTH.
DEPENDING ON THE STRENGTH OF THE LOW WIND SPEEDS MAY NEED TO BE
INCREASED OVER CURRENT FORECAST VALUES. SHOULD A MUCH DEEPER
SCENARIO PAN OUT...WHICH AGAIN LOOKS TO BE A RATHER LOW
PROBABILITY...THEN GALES COULD DEVELOP. THE LOW THEN CLEARS TO THE
EAST THURSDAY MORNING LEAVING A WEAK PRESSURE GRADIENT BEHIND IT
BUT AHEAD OF A WEAKER LOW WHICH WILL CROSS THE LAKE FRIDAY
MORNING. HIGH PRESSURE WILL GRADUALLY BUILD ON SATURDAY.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
902 PM CDT MON JUL 23 2012
.UPDATE /HEAT/...
FOR PUBLIC AWARENESS...HAVE DECIDED TO ISSUE A HEAT ADVISORY THROUGH
WEDNESDAY ON THE NORTH AND EAST SIDES OF THE EXISTING HEAT WARNING.
TWO DAYS HAVE ALREADY SEEN TEMPERATURES NEAR OR ABOVE 100...SOMEWHAT
WARMER THAN ANTICIPATED...AND NIGHTS WILL BE WARM. STILL SOME
UNCERTAINTY WHETHER SURFACE BOUNDARY...WHICH IS CURRENTLY RUNNING
FROM ALGONA TO NORTH OF WATERLOO...WILL SAG FARTHER SOUTH PER
SEVERAL NUMERICAL MODELS. HOWEVER...WITH 00Z SOUNDINGS NOT REALLY
FAVORABLE FOR CONVECTION IN IOWA AND CURRENT ACTIVITY DEVELOPING
WELL NORTH IN WESTERN MINNESOTA...IT APPEARS ANY BOUNDARY PUSH SOUTH
WILL NOT LAST TOO LONG. ANOTHER FACTOR CONSIDERED IS THAT DEWPOINTS
JUMP INTO 70S NORTH OF THAT BOUNDARY...PROVIDING LITTLE RELIEF.
WAITING TO SEE THE 00Z MODELS...BUT WEDNESDAY COULD BE HOTTEST YET
WITH A VERY WARM START IF BOUNDARY REMAINS NORTH.
.SHORT TERM /TONIGHT/...
MAIN FORECAST CONCERN IS POTENTIAL FOR CONVECTION ACROSS NORTHERN
IOWA TONIGHT. WEAK BOUNDARY EXTENDS ACROSS SOUTHERN MN COMBINED WITH
AN 500MB VORT MAX WILL BE THE FOCUS FOR THUNDERSTORMS LATER THIS
EVENING INTO TUESDAY MORNING.
NAM/SREF/RAP KEEP CONVECTION ALONG THE BORDER OVERNIGHT...4.0KM WRF
FROM NCEP HAS SOME ISOLATED CONVECTION ACROSS THE NORTHERN TWO TIERS
OF COUNTIES AND THE NSSL 4.0KM WRF IS SIMILAR. LATEST HRRR (17Z RUN)
IS MORE BULLISH IN BREAKING OUT CONVECTION THIS AFTERNOON INTO THE
EVENING AND SEEMS MORE WIDESPREAD THAN ANY OTHER MODEL. LEANED
TOWARD A BLEND OF THE NAM12/SREF WITH TIMING AND PLACEMENT OF
CONVECTION OVER NORTHERN IOWA PAST 03Z TUESDAY. WITH THE VERY DRY
AIR MASS IN THE LOWER LEVELS AND BUFR SOUNDINGS INDICATIVE OF MAINLY
WIND THREAT AS THEY MIX UP TO AROUND 850-700MB DEPENDING ON WHICH
MODEL...CANNOT RULE AN ISOLATED SEVERE POTENTIAL TONIGHT ACROSS
NORTHERN IOWA. EFFECTIVE SHEAR AROUND 35-40KTS BUT THERE IS
LITTLE...IF ANY...LOW LEVEL SHEAR WITH 0-1KM AND 0-3KM SHEAR LESS
THAN 15KTS AND 30KTS RESPECTIVELY. THERE IS PLENTY OF INSTABILITY
PRESENT BUT WITH SUCH A STRONG CAP IN PLACE...IT WILL TAKE SOME TIME
FOR IT ERODE. WITH THE UPPER LEVEL VORT MAX TIMING TO MOVE INTO
NORTHERN IOWA AFTER 03Z...HAVE HIGHEST POPS B/T 06-12Z TUESDAY.
.LONG TERM /TUESDAY THROUGH MONDAY/...
THERE IS LITTLE CHANGE NEEDED TO THE GOING FORECAST. IT WILL REMAIN
HOT THROUGH WEDNESDAY WITH CHANCES FOR SHOWERS/THUNDERSTORMS ACROSS
THE NORTHEAST AND EAST. SOUNDING ARE SHOWING SOME DRY AIR ALOFT AND
A CLASSIC INVERTED V SO THERE IS SOME POTENTIAL FOR STRONG/DAMAGING
WIND WITH THESE STORMS AND THAT IS COVERED IN VARIOUS OUTLOOKS. THE
MODELS ARE A LITTLE SLOWER IN BRINGING THE FRONT THROUGH SO
WEDNESDAY HIGHS MAY NEED TO BE BROUGHT UP BUT I WOULD LIKE TO SEE
WHAT CLOUDS/CONVECTIVE TRENDS WILL DO BEFORE RAISING THEM MORE THAN
I HAVE DONE. SOMETHING ELSE OF NOTE THAT MAY BE A CAVEAT TO THE
SEVERE POTENTIAL IS THAT THE MODELS HAD BEEN ADVERTISING A VORT MAX
TO DROP DOWN THE RIDGE ACROSS THE EAT/NORTHEAST AND NOW THEY ARE
TAKING THAT VORT MAX EAST AND NOT DROPPING IT SOUTH. QPF IS ALSO
LESS NOW FOR THE AREA WHICH IS NOT A SURPRISE REALLY. OTHER THINGS
OF NOTE IS THAT A SHORTWAVE THAT WAS PROGGED FOR SATURDAY NIGHT IS
NOW COMING THROUGH ON SUNDAY. THIS IS ADVERTISED BY BOTH THE GFS
AND EURO SO I LEFT SATURDAY DRY AND INCREASED POPS ON SUNDAY. TEMPS
WILL STILL BE SEASONAL BUT COMPARED TO WHAT WE HAVE THE TERM
"COOLER" CAN BE APPLIED HERE AND IT WILL IN DEED FEEL THAT WAY.
HIGHS FOR THE WEEKEND WILL BE IN THE LOWER TO MID 80S WITH MAYBE
SOME 90S ACROSS THE FAR SOUTHWEST.
THE COOLER TEMPS DO NOT APPEAR TO BE STAYING AS WAS ELUDED TO
YESTERDAY...THE MODELS REBUILD THE RIDGE OVER THE ROCKIES AND TRENDS
ARE TO BRING THE UPPER RIDGE BACK INTO THE MIDWEST. THIS WILL OCCUR
BEYOND THE EXTENDED PERIOD SO JUST HOW MUCH HEAT WE WILL SEE IS
STILL GOING TO NEED TO BE EVALUATED. WE WILL AT LEAST SEE A SEVERAL
DAY BREAK FROM THE OPPRESSIVE HEAT LATER THIS WEEK.
&&
.AVIATION...24/00Z
EXPECTING VFR CONDITIONS THROUGHOUT THE TAF FORECAST PERIOD EVEN
WITH THE SURFACE BOUNDARY POSSIBLY SAGGING SOUTH OF KMCW/KALO
OVERNIGHT. ISOLATED TSTM ARE STILL POSSIBLE THIS EVENING...BUT
INDICATIONS ARE IT WILL STAY NORTH OF KMCW/KALO. OTHERWISE...WINDS
MIX DOWN AGAIN TOMORROW WITH SOME GUSTS TO AROUND 15KTS POSSIBLE.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
EXCESSIVE HEAT WARNING UNTIL 7 PM CDT WEDNESDAY FOR ADAIR-ADAMS-
APPANOOSE-AUDUBON-BOONE-CALHOUN-CARROLL-CASS-CLARKE-CRAWFORD-
DALLAS-DAVIS-DECATUR-GREENE-GUTHRIE-HAMILTON-JASPER-LUCAS-
MADISON-MAHASKA-MARION-MONROE-POLK-RINGGOLD-SAC-STORY-TAYLOR-
UNION-WAPELLO-WARREN-WAYNE-WEBSTER.
HEAT ADVISORY UNTIL 7 PM CDT WEDNESDAY FOR BLACK HAWK-BREMER-
BUTLER-FRANKLIN-GRUNDY-HARDIN-HUMBOLDT-MARSHALL-POCAHONTAS-POWESHIEK-
TAMA-WRIGHT.
&&
$$
UPDATE...JUNGBLUTH
LONG TERM...FAB
SHORT TERM...PODRAZIK
AVIATION...JUNGBLUTH
AREA FORECAST DISCUSSION
NWS DES MOINES IA
648 PM CDT MON JUL 23 2012
...UPDATE TO AVIATION FORECAST 24/00Z...
.SHORT TERM /TONIGHT/...
MAIN FORECAST CONCERN IS POTENTIAL FOR CONVECTION ACROSS NORTHERN
IOWA TONIGHT. WEAK BOUNDARY EXTENDS ACROSS SOUTHERN MN COMBINED WITH
AN 500MB VORT MAX WILL BE THE FOCUS FOR THUNDERSTORMS LATER THIS
EVENING INTO TUESDAY MORNING.
NAM/SREF/RAP KEEP CONVECTION ALONG THE BORDER OVERNIGHT...4.0KM WRF
FROM NCEP HAS SOME ISOLATED CONVECTION ACROSS THE NORTHERN TWO TIERS
OF COUNTIES AND THE NSSL 4.0KM WRF IS SIMILAR. LATEST HRRR (17Z RUN)
IS MORE BULLISH IN BREAKING OUT CONVECTION THIS AFTERNOON INTO THE
EVENING AND SEEMS MORE WIDESPREAD THAN ANY OTHER MODEL. LEANED
TOWARD A BLEND OF THE NAM12/SREF WITH TIMING AND PLACEMENT OF
CONVECTION OVER NORTHERN IOWA PAST 03Z TUESDAY. WITH THE VERY DRY
AIR MASS IN THE LOWER LEVELS AND BUFR SOUNDINGS INDICATIVE OF MAINLY
WIND THREAT AS THEY MIX UP TO AROUND 850-700MB DEPENDING ON WHICH
MODEL...CANNOT RULE AN ISOLATED SEVERE POTENTIAL TONIGHT ACROSS
NORTHERN IOWA. EFFECTIVE SHEAR AROUND 35-40KTS BUT THERE IS
LITTLE...IF ANY...LOW LEVEL SHEAR WITH 0-1KM AND 0-3KM SHEAR LESS
THAN 15KTS AND 30KTS RESPECTIVELY. THERE IS PLENTY OF INSTABILITY
PRESENT BUT WITH SUCH A STRONG CAP IN PLACE...IT WILL TAKE SOME TIME
FOR IT ERODE. WITH THE UPPER LEVEL VORT MAX TIMING TO MOVE INTO
NORTHERN IOWA AFTER 03Z...HAVE HIGHEST POPS B/T 06-12Z TUESDAY.
.LONG TERM /TUESDAY THROUGH MONDAY/...
THERE IS LITTLE CHANGE NEEDED TO THE GOING FORECAST. IT WILL REMAIN
HOT THROUGH WEDNESDAY WITH CHANCES FOR SHOWERS/THUNDERSTORMS ACROSS
THE NORTHEAST AND EAST. SOUNDING ARE SHOWING SOME DRY AIR ALOFT AND
A CLASSIC INVERTED V SO THERE IS SOME POTENTIAL FOR STRONG/DAMAGING
WIND WITH THESE STORMS AND THAT IS COVERED IN VARIOUS OUTLOOKS. THE
MODELS ARE A LITTLE SLOWER IN BRINGING THE FRONT THROUGH SO
WEDNESDAY HIGHS MAY NEED TO BE BROUGHT UP BUT I WOULD LIKE TO SEE
WHAT CLOUDS/CONVECTIVE TRENDS WILL DO BEFORE RAISING THEM MORE THAN
I HAVE DONE. SOMETHING ELSE OF NOTE THAT MAY BE A CAVEAT TO THE
SEVERE POTENTIAL IS THAT THE MODELS HAD BEEN ADVERTISING A VORT MAX
TO DROP DOWN THE RIDGE ACROSS THE EAT/NORTHEAST AND NOW THEY ARE
TAKING THAT VORT MAX EAST AND NOT DROPPING IT SOUTH. QPF IS ALSO
LESS NOW FOR THE AREA WHICH IS NOT A SURPRISE REALLY. OTHER THINGS
OF NOTE IS THAT A SHORTWAVE THAT WAS PROGGED FOR SATURDAY NIGHT IS
NOW COMING THROUGH ON SUNDAY. THIS IS ADVERTISED BY BOTH THE GFS
AND EURO SO I LEFT SATURDAY DRY AND INCREASED POPS ON SUNDAY. TEMPS
WILL STILL BE SEASONAL BUT COMPARED TO WHAT WE HAVE THE TERM
"COOLER" CAN BE APPLIED HERE AND IT WILL IN DEED FEEL THAT WAY.
HIGHS FOR THE WEEKEND WILL BE IN THE LOWER TO MID 80S WITH MAYBE
SOME 90S ACROSS THE FAR SOUTHWEST.
THE COOLER TEMPS DO NOT APPEAR TO BE STAYING AS WAS ELUDED TO
YESTERDAY...THE MODELS REBUILD THE RIDGE OVER THE ROCKIES AND TRENDS
ARE TO BRING THE UPPER RIDGE BACK INTO THE MIDWEST. THIS WILL OCCUR
BEYOND THE EXTENDED PERIOD SO JUST HOW MUCH HEAT WE WILL SEE IS
STILL GOING TO NEED TO BE EVALUATED. WE WILL AT LEAST SEE A SEVERAL
DAY BREAK FROM THE OPPRESSIVE HEAT LATER THIS WEEK.
&&
.AVIATION...24/00Z
EXPECTING VFR CONDITIONS THROUGHOUT THE TAF FORECAST PERIOD EVEN
WITH THE SURFACE BOUNDARY POSSIBLY SAGGING SOUTH OF KMCW/KALO
OVERNIGHT. ISOLATED TSTM ARE STILL POSSIBLE THIS EVENING...BUT
INDICATIONS ARE IT WILL STAY NORTH OF KMCW/KALO. OTHERWISE...WINDS
MIX DOWN AGAIN TOMORROW WITH SOME GUSTS TO AROUND 15KTS POSSIBLE.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
EXCESSIVE HEAT WARNING UNTIL 7 PM CDT WEDNESDAY
ADAIR-ADAMS-APPANOOSE-AUDUBON-BOONE-CALHOUN-CARROLL-CASS-CLARKE-
CRAWFORD-DALLAS-DAVIS-DECATUR-GREENE-GUTHRIE-HAMILTON-JASPER-LUCAS-
MADISON-MAHASKA-MARION-MONROE-POLK-RINGGOLD-SAC-STORY-TAYLOR-UNION-
WAPELLO-WARREN-WAYNE-WEBSTER.
&&
$$
LONG TERM...FAB
SHORT TERM...PODRAZIK
AVIATION...JUNGBLUTH
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1203 AM CDT SUN JUL 22 2012
.UPDATE...
ADDED 06Z TAF DISCUSSION.
CONVECTION HAS ALREADY EXPANDED ACROSS FAR SRN SD AND SRN MN SO HAVE
UPPED PRECIP CHANCES FAR NORTH.
PREVIOUS UPDATE...NO APPRECIABLE CHANGES TO FORECAST TONIGHT. WAS
SOME CONCERN REGARDING FATE OF SMALL CONVECTIVE CLUSTER APPROACHING
YANKTON AS IT RODE TOP OF ELEVATED MIXED LAYER...BUT THAT CONTINUES
TO DISSIPATE. EXAMINATION OF RAP ELEVATED INSTABILITY LAYERS
SUGGESTS MOST FAVORABLE CAPE/CIN ALOFT CONTINUES TO LIFT NORTHWARD
INTO SD AND MN OVERNIGHT. THIS APPEARS TO BE COINCIDENT WITH SHARP
BAROCLINIC ZONE NOTED ALONG RAP 315K ISENT SURFACE. STRONG UVM AND
MOISTURE CONVERGENCE IS NOTED ON NOSE OF 30-40KT FLOW AFTER MIDNIGHT
WITH ISENT SURFACE CHANGING FROM 900-700MB ALONG TRAJECTORY FROM
CENTRAL NE INTO SWRN MN. WITH THIS IN MIND EXPECT CURRENT WRN SD
MCS TO EXPAND EASTWARD EARLY SUN MORNING...AND/OR AN INCREASE OF
CURRENT ELEVATED SHOWERS FESTERING OVER SRN MN. MAY EVEN SEE SOME
SORT OF CONNECTION. SEVERAL SUPPORTING WRF RUNS AND THE LATEST HRRR
FOCUS ALONG THE SD/MN BORDER...WITH THE HRRR EVEN BLOSSOMING
CONVECTION INTO IA OVERNIGHT. FEEL THIS IS TOO AGGRESSIVE SOUTH
CONSIDERING THE MEAN WIND BEING MORE EAST THAN SOUTH...BUT SEE NO
REASON TO CHANGE CURRENT OVERNIGHT LOW POPS NORTH AT THIS POINT.
&&
.SHORT TERM /TONIGHT/...
SERIES OF VORTICITY CENTERS TUMBLING DOWN EAST SIDE OF UPPER RIDGE
AND SOME MID-LEVEL WARM ADVECTION HAVE KEPT SHOWERS GOING INTO THE
AFTERNOON ACROSS NORTHERN AND EASTERN IOWA. ASSOCIATED SPILLAGE OF
CLOUDS FARTHER SOUTH HELD DOWN HIGH TEMPERATURES SOMEWHAT TODAY BUT
DID NOT PRODUCE ANY BENEFICIAL RAINFALL. IT APPEARS THE PATTERN
WON`T CHANGE MUCH OVERNIGHT...AND WITH ANOTHER VORTICITY CENTER
SHOWING UP NEAR THE BLACK HILLS AND ANOTHER SURGE OF 850 MB WINDS
OVERNIGHT...CONVECTION SHOULD DEVELOP AGAIN NEAR THE MINNESOTA
BORDER BY MIDNIGHT OR SO. AGAIN...THIS SHOULD NOT BE VERY INTENSE
AND WILL REMAIN ELEVATED...BUT IT WILL HAVE CONSEQUENCES FOR CLOUD
COVER INTO SUNDAY. LIGHT SOUTH FLOW WILL PERSIST OVERNIGHT AT THE
SURFACE WITH THE LOW PRESSURE CENTER REMAINING IN SOUTH DAKOTA. TO
THIS POINT...THE SOUTH WINDS ARE NOT BRINGING IN A LOT OF
HUMIDITY...EXCEPT IN NORTHERN IOWA NEARER THE SURFACE BOUNDARY WHICH
IS POSITIONED IN SOUTHERN MINNESOTA. AS A RESULT...LOW TEMPERATURES
SHOULD DROP TO NEAR 70 DEGREES IN MOST LOCATIONS WITH THE EXCEPTION
OF THE DES MOINES AND CENTRAL IOWA HEAT ISLANDS.
.LONG TERM /SUNDAY THROUGH SATURDAY/...
FORECAST CONCERNS IN THE EXTENDED REVOLVE AROUND WHERE THE
CONVECTION AND CLOUDS WILL HAMPER TEMPS AND AFFECT THE EXCESSIVE
HEAT WARNING. THE EFFECTS OF WHICH WERE MADE EVIDENT TODAY. THE
MODELS ARE CONSISTENT IN KEEPING SHORTWAVES RIDGING OVER THE
PERIPHERY OF THE UPPER LEVEL RIDGE. MODELS ARE CONSISTENT IN
DEVELOPING STORMS OVER SOUTHERN MINNESOTA AND CORFIDI VECTORS DROP
THE STORMS INTO NORTHERN/EASTERN IOWA...MUCH LIKE TODAY...EXCEPT
THAT THE SOUTHERN EXTEND OF THE STORMS IS A BIT MORE IN QUESTION.
NONE THE LESS...CLOUD COVER WILL BE OVER THE AREA AND AFFECT THE
TEMPS. HEAT INDICES...ESPECIALLY ACROSS THE SOUTH AND WEST...WHILE
A LITTLE LOWER ARE STILL IN THE 101-106 RANGE. THIS FALLS A BIT
SHORT OF THE WARNING CRITERIA BUT IF WE GET A LITTLE MORE SUN OR
THE STORMS DON`T EVOLVE AS FAR SOUTH THEN WE WILL HAVE NO PROBLEM
HEATING UP. MY CONFIDENCE IS NOT HIGH ENOUGH TO CHANGE THE WARNING
AT THIS POINT. THERE IS ONE EXCEPTION...NORTH OF HIGHWAY 20 IS THE
MOST UNLIKELY AREA TO SEE EXCESSIVE HEAT. SHOWERS/CLOUDS WILL
PLAGUE THIS AREA JUST ABOUT EVERY DAY OF THE WARNING. FOR THIS
REASON I HAVE DROPPED THE WARNING NORTH OF HIGHWAY 20 WHICH
AMOUNTS TO ONE TIER OF COUNTIES.
MONDAY AND TUESDAY DEFINITELY LOOK LIKE THE HOTTEST DAYS OF THE
WEEK SO LITTLE CHANGES MADE TO THE FORECAST HERE EXCEPT TO TWEAK
TEMPS A BIT.
FOR WEDNESDAY A STRONG UPPER LEVEL LOW TRAVELING ACROSS SOUTHERN
CANADA WILL FLATTEN THE RIDGE WHILE AT THE SURFACE A WEAK COLD
FRONT WILL SHIFT ACROSS THE FORECAST AREA. THERE IS DECENT FORCING
ALONG THE BOUNDARY AND OFFERS OUR BEST CHANCE AT SEEING
CLOUDS/STORMS. TIMING OF THE BOUNDARY AT THIS POINT REMAINS IN
QUESTION WHICH PUTS INTO QUESTION WHETHER WE WILL NEED AN
EXCESSIVE HEAT WARNING FOR WEDNESDAY BUT AGAIN...MY CONFIDENCE IS
NOT HIGH ENOUGH TO DROP IT FOR THE PERIOD SO I WILL LET IT RIDE
FOR NOW. HOWEVER...I DID INCREASE POPS/CLOUDS AND KNOCK TEMPS
BACK A BIT. THE SAME LOGIC IS APPLIED FOR THIS PERIOD AS WELL. WE
FALL A BIT SHY ON THE CRITERIA BUT IF WE GET A BIT MORE SUN OR THE
FRONT SLOWS...WE WILL HAVE NO PROBLEM REACHING CRITERIA.
AS FOR THE REST OF THE EXTENDED...THE RIDGE REBUILDS TO OUR WEST
PUTTING US IN A MORE NW FLOW WITH WEAK HIGH PRESSURE AT THE
SURFACE. THIS WILL BRING A BREAK TO THE HEAT AND ACTUALLY PRODUCE
HIGHS THAT ARE MORE SEASONAL. HIGHS BY NEXT WEEKEND WILL BE IN THE
MID TO UPPER 80S WHICH WILL BE A WELCOME RELIEF TO WHAT WE HAVE HAD.
&&
.AVIATION...22/06Z
PRIMARY CONCERN WILL BE CONVECTIVE TRENDS OVERNIGHT. THUNDERSTORMS
CONTINUE TO EXPAND OVER SRN SD AND SRN MN AND EXPECT THE COMPLEXES
EVENTUALLY TURN SEWD AFFECTING NRN SITES /KMCW/KALO/. CIGS WILL
PRIMARY REMAIN VFR THROUGH THE PERIOD...BUT COULD BRIEFLY DIP TO
MVFR CIGS OR VSBYS IF A HEAVIER STORM IMPACTS A SITE. CONFIDENCE IN
THIS OCCURRING IS NOT GREAT HOWEVER SO HAVE NOTHING MORE THAN VFR
VCTS. ANY CONVECTION SHOULD EXIT THE AREA BY SUN MORNING WITH SLY
WINDS INCREASING AND BECOMING SOMEWHAT GUSTY.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
EXCESSIVE HEAT WARNING UNTIL 3PM WED
ADAIR-ADAMS-APPANOOSE-AUDUBON-BOONE-CALHOUN-CARROLL-CASS-CLARKE-
CRAWFORD-DALLAS-DECATUR-GREENE-GUTHRIE-HAMILTON-JASPER-LUCAS-MADISON-
MARION-MONROE-POLK-RINGGOLD-SAC-STORY-TAYLOR-UNION-WARREN-WAYNE-
WEBSTER
EXCESSIVE HEAT WARNING FROM 1PM SUN TO 3PM WED
BLACK HAWK-DAVIS-GRUNDY-HARDIN-MAHASKA-MARSHALL-POWESHIEK-TAMA-
WAPELLO
&&
$$
LONG TERM...FAB
SHORT TERM...JUNGBLUTH
AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1054 PM MDT SAT JUL 21 2012
.UPDATE...
ISSUED AT 903 PM MDT SAT JUL 21 2012
THE RED FLAG WARNING WAS ALLOWED TO EXPIRE.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 1251 PM MDT SAT JUL 21 2012
AS OF EARLY THIS AFTERNOON THE CENTER OF THE UPPER LEVEL HIGH IS
JUST NORTHEAST OF THE CWA ALLOWING THIN CIRRUS TO ROTATE NORTHWEST
OVER MUCH OF THE AREA. SOME FLAT CU HAS ALSO DEVELOPED OVER THE FAR
WRN QUARTER OF THE CWA ATOP A LEE TROUGH. TEMPS THUS FAR FOR MOST
LOCATIONS ARE AT OR ABOVE THE CENTURY MARK.
FOR THE REST OF THE AFTERNOON RELATIVE HUMIDITIES SHOULD CONTINUE
TO SLOWLY DECREASE ESPECIALLY ACROSS THE WRN ZONES WHERE THE RED FLAG
WARNING IS IN PLACE. THE SFC WINDS HAVE BEEN RATHER LIGHT IN THE
15 TO 25 MPH RANGE THUS FAR...SO ONLY PORTIONS OF THE WARNING ARE
VERIFYING TO THIS POINT. HAVE LEFT THE FCST DRY TODAY THROUGH
TOMORROW DESPITE THE HRRR GENERATING ISOLATED STORMS THIS
AFTERNOON ALONG/NEAR THE SFC TROUGH (WHERE THE CU IS CURRENTLY
LOCATED).
FOR TONIGHT I WENT WITH A PERSISTENCE FORECAST FOLLOWING LAST
NIGHT/S LOW TEMPS ALONG WITH LIGHT SOUTHERLY WINDS AND MOSTLY
CLEAR SKIES. TOMORROW WILL ONCE AGAIN BE HOT WITH LOW 100S ACROSS
THE BOARD...WARMEST EAST WHERE THE HEAT ADVISORY IS. HAVE DEBATED
WHETHER TO ISSUE A FIRE WEATHER WATCH FOR TOMORROW FOR GENERALLY
THE SAME LOCATIONS AS TODAY/S RED FLAG WARNING. THE FORECASTED
RELATIVE HUMIDITIES REACH CRITERIA BUT THE WINDS APPEAR A BIT TOO
LIGHT. WANT TO SEE HOW TODAY PLAYS OUT AS TODAY AND TOMORROW ARE
NEARLY IDENTICAL FOR MET CONDITIONS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 233 PM MDT SAT JUL 21 2012
THE STRONG H5 RIDGE REMAINS IN PLACE THROUGH MONDAY NIGHT. VERY
LITTLE CHANGES REGARDING THE AIRMASS ALOFT WITH SIMILAR HIGH TEMPS
EACH DAY THROUGH MIDWEEK. NO CHANGE TO CURRENT HEAT ADVISORY WITH
EASTERN LOCATIONS EXPECTED TO HAVE HEAT INDEX VALUES AROUND 105.
TEMPERATURES ALOFT WILL COOL SOME AFTER TUESDAY AS H5 HEIGHTS
BEGIN TO DECREASE...HOWEVER WITH RIDGING OF SOME FASHION EXPECTED
TO CONTINUE...ABOVE NORMAL TEMPERATURES IN THE UPPER 90S/NEAR 100
WILL CONTINUE THROUGH THE EXTENDED PERIODS.
DRY CONDITIONS ARE EXPECTED TO PERSIST WITH RED FLAG CONDITIONS
POSSIBLE AGAIN ON MONDAY...DEPENDING ON WINDS. BEST CHANCE FOR PRECIP
WILL BE TUESDAY AFTERNOON THROUGH WEDNESDAY NIGHT WHEN A STRONG
UPPER LOW MOVES ACROSS SOUTHERN CANADA...AND A TRAILING SHORTWAVE
TROUGH MOVES ACROSS THE PLAINS. THERE REMAINS UNCERTAINTY REGARDING
THE POSITION/STRENGTH OF THE TRAINING SHORTWAVE...WITH ECMWF FURTHER
SOUTH AND STRONGER. IGNORING THE DIFFERENCES REGARDING LARGE SCALE
ASCENT...MOISTURE PROFILES ARE UNIMPRESSIVE. DEEP DRY LAYER TO 650MB
REMAINS IN PLACE THROUGH THESE PERIODS. BASED ON SOUNDINGS ISOLATED
DRY THUNDERSTORMS MAY ULTIMATELY BE FAVORED...HOWEVER WITH BOTH GFS
AND ECMWF ARE BOTH SHOWING QPF OF SOME SORT AROUND THE AREA SO
MEASURABLE PRECIP CANT BE RULED OUT. I DECIDED TO KEEP ISOLATED
THUNDERSTORM MENTION FOR NOW. RIDGING BEGINS TO BUILD BACK OVER THE
INTER-MOUNTAIN WEST ON THURSDAY AND SHOULD CONTINUE TO DOMINATE THE
WEATHER OVER THE PLAINS THROUGH NEXT WEEKEND. THERE IS SOME
INDICATION OF A SHORTWAVE TROUGH PASSAGE NEXT WEEKEND OVER EASTERN
NEBRASKA...HOWEVER MOISTURE SEEMS TO BE CUT OFF FROM OUR AREA. WITH
STABLE AIR MASS ALOFT OVER OUR CWA..CONFIDENCE IS LOW IN ANY
ACTIVITY INITIATING OVER OUR CWA...SO I KEPT FORECAST DRY AFTER
WEDNESDAY NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1053 PM MDT SAT JUL 21 2012
LITTLE TO NO CHANGE WITH VFR CONDITIONS EXPECTED THROUGH THE
PERIOD. SOUTHERLY WINDS WILL BECOME GUSTY AS THE AIR MASS QUICKLY
HEATS UP.
&&
.CLIMATE...
ISSUED AT 233 PM MDT SAT JUL 21 2012
VERY HOT TEMPERATURES ARE EXPECTED TO CONTINUE THROUGH NEXT
WEEK...WITH SEVERAL LOCATIONS POSSIBLY BREAKING DAILY TEMPERATURE
RECORDS.
DAILY RECORDS FOR SUNDAY (JUL 22)...
GOODLAND.....105 (1934)
HILL CITY....108 (1934)
BURLINGTON...104 (1990)
MCCOOK.......110 (1931)
YUMA.........109
TRIBUNE......107
COLBY........107
DAILY RECORDS FOR MONDAY (JUL 23)...
GOODLAND.....110 (1936)
HILL CITY....107 (1940)
BURLINGTON...105 (1963)
MCCOOK.......106 (1940)
YUMA.........107
TRIBUNE......107
COLBY........105
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...HEAT ADVISORY UNTIL 9 PM CDT TUESDAY FOR KSZ002>004-014>016-028-
029-042.
CO...NONE.
NE...HEAT ADVISORY UNTIL 9 PM CDT TUESDAY FOR NEZ080-081.
&&
$$
UPDATE...BULLER
SHORT TERM...05
LONG TERM...DR
AVIATION...BULLER
CLIMATE...DR
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
810 PM EDT MON JUL 23 2012
.UPDATE...
ISSUED AT 810 PM EDT MON JUL 23 2012
RAN ANOTHER UPDATE TO KEEP THE GRIDS IN CHECK WITH THE CURRENT
CONDITIONS AND TRENDS. THE ATMOSPHERE REMAINS UNSTABLE...BUT ANY
TRIGGERS FOR ARE LACKING. WILL BE WATCHING FOR ANY DEVELOPMENT WITH
THE CONVECTION TRYING TO POP UP OVER SOUTHEAST INDIANA...BUT
INSTABILITY OVER EAST KENTUCKY WILL BE DIMINISHING THROUGH THE
EVENING AND OVERNIGHT. ACCORDINGLY...WILL KEEP POPS LOW THROUGH THE
NIGHT...BUT NOT COMPLETELY ZEROED OUT. ALSO ADDED A TOUCH OF DEEPER
VALLEY FOG TO THE GRIDS. UPDATES TO NDFD...THE WEB AND ZONES WILL BE
ISSUED SHORTLY.
UPDATE ISSUED AT 545 PM EDT MON JUL 23 2012
DID A QUICK UPDATE TO THE GRIDS AND WEB FORECAST TO ACCOUNT FOR
CONVECTIVE TRENDS...OR LACK THERE OF...INTO THE EVENING. ALSO UPDATED
THE SKY...TEMPERATURE AND DEWPOINT GRIDS FOR THEIR CURRENT
OBSERVATIONS AND TRENDS. UPDATES SENT TO THE WEB AND NDFD...THE
ZONES ARE STILL FINE.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 313 PM EDT MON JUL 23 2012
HIGH PRESSURE RIDGE CONTINUES TO DOMINATE TO OUR WEST AND
SOUTH...WITH EASTERN KENTUCKY SITTING ON THE PERIPHERALS. THIS
MEANS...OUR AREA REMAINS A FOCUS OF CONCERN FOR REPEATED CHANCES FOR
SHOWERS AND THUNDERSTORMS OVER THE NEXT 24 TO 48 HOURS. A FEW
ISOLATED SHOWERS HANGING ON NEAR THE VIRGINIA BORDER THIS
AFTERNOON...BUT THESE SHOULD EXIT INTO VIRGINIA IN THE NEXT HOUR OR
SO. A LULL IS EXPECTED INTO THIS EVENING. HOWEVER...A SHORTWAVE
TROUGH IS PUSHING INTO SOUTHERN OHIO AND INDIANA. PRESENTLY...NOT MUCH
ACTIVITY ASSOCIATED WITH THIS FEATURE. IN FACT...THE SHOWER ACTIVITY
EARLIER HAS ALMOST COMPLETELY DRIED UP. STILL SOME QUESTION ON HOW
MUCH DEVELOPMENT WILL OCCUR AS THIS TROUGH AXIS PUSHES SOUTH INTO
A MORE UNSTABLE AIRMASS. IT IS POSSIBLE WE COULD SEE A FEW ISOLATED
SUPERCELLS CAPABLE OF DAMAGING WINDS THROUGH 9 OR 10 PM. THE HRRR HAS
HELD CONSISTENT WITH THE IDEA OF ISOLATED SUPERCELLS DEVELOPING AFTER
8 PM...AND TRACKING INTO AREAS NORTH OF I-64 AROUND 9 OR 10 PM. THERE
IS SOME WEAK DIRECTIONAL SHEAR TO SUPPORT THIS IDEA. THUS...PLAN TO
INCLUDE A SLIGHT CHANCE OF SHOWERS AND STORMS THROUGH LATE EVENING.
THIS ACTIVITY WILL GRADUALLY WEAKEN AS IT PUSHES FURTHER SOUTH...SO
THE SECOND HALF OF THE NIGHT SHOULD BE MAINLY DRY.
MOVING ON TO TOMORROW...IT LOOKS LIKE ANOTHER DECENT WAVE WILL DROP
SOUTHEAST FROM MIDDAY INTO THE EVENING HOURS...PRODUCING AN EVEN
BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS. WIND SHEAR WILL BE EVEN
BETTER TOMORROW WITH 700MB WINDS AROUND 30 KNOTS AND 500MB WINDS 35
KNOTS. THERE IS SOME DIRECTIONAL SHEAR AS WELL. THUS...SEVERE THREAT
LOOKS PRETTY GOOD TOMORROW FOR SOME DAMAGING WINDS. THE BIGGER
CONCERN COULD BE SOME LOCALLY HEAVY RAIN WITH PW VALUES AROUND 2
INCHES AND FREEZING LEVELS OVER 15KFT. ANY STORMS THAT HIT THE SAME
AREAS COULD LEAD TO FLASH FLOODING. NOT CONFIDENT ENOUGH TO GO WITH A
WATCH...BUT CERTAINLY SOMETHING TO KEEP AN EYE ON.
BY TOMORROW NIGHT...THE FIRST ROUND OF CONVECTION WILL DEPART...BUT
WE WILL REMAIN IN A FAVORABLE SPOT FOR MORE DEVELOPMENT
UPSTREAM...WITH PERHAPS A NOCTURNAL MCS DEVELOPING AND TRACKING INTO
OUR AREA. THUS...WILL KEEP SOME CHANCE POPS GOING THROUGH TOMORROW
NIGHT.
TEMPERATURES WILL REMAIN MILD WITH HIGHS ON TUESDAY CLIMBING TO
AROUND 90 AND LOWS TONIGHT AND TOMORROW NIGHT IN THE LOWER 70S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 341 PM EDT MON JUL 23 2012
THE MODELS START OUT IN VERY GOOD AGREEMENT WITH A FAIRLY ZONAL FLOW
NORTH OF 40 DEGREES AND UPPER RIDGING DOMINATES SOUTH OF 40 DEGREES.
THE SYSTEM TO WATCH IS AN UPPER LOW IN SOUTHWEST MANITOBA WITH A
TROUGH EXTENDING INTO THE CENTRAL PLAINS. THIS UPPER LOW STARTS
MOVING SLOWLY TO THE EAST SOUTHEAST AND AS IT DOES...IT IS PUSHING
THE POLAR FRONT TO THE SOUTH. THE TROUGH CONTINUE PUSHING TO THE ESE
AND WILL PUSH A FRONT ACROSS THE COAL FIELDS ON FRIDAY. THIS FRONT
WILL STAY JUST SOUTH OF THE AREA AND WILL PUSH BACK INTO THE AREA ON
SUNDAY NIGHT. THE DIFFERENCE IN SHORT WAVE TIMING INCREASES WITH
TIME...HOWEVER THE GENERAL PATTERN TRANSITION IS IN PRETTY GOOD
AGREEMENT. THE SEQUENCING HAS HIGH CONFIDENCE...HOWEVER THE TIMING
OF THE SHORT WAVES DECREASES CONFIDENCE IN WITH TIME. FOR
TEMPS...NUDGED THE FORECAST TOWARD THE MODEL BLEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 810 PM EDT MON JUL 23 2012
THE REMAINING CU WILL DISSIPATE THIS EVENING...THEN REDEVELOP AFTER
DAYBREAK TOMORROW MORNING. A FAIRLY STRONG DISTURBANCE IS POISED TO
DROP IN FROM THE NORTH TOMORROW...PROVIDING A BETTER CHANCE FOR
SHOWERS AND THUNDERSTORMS. FOR THE AVIATION GRIDS AND TAFS HAVE PUT
THE BEST TIMING ON THE CONVECTIVE DEVELOPMENT AS AFTER 14Z PEAKING
BETWEEN 16-22Z FROM NORTH TO SOUTH ACROSS THE CWA PER THE LATEST
GUIDANCE. GUSTY WINDS WILL BE POSSIBLE WITH THE STORMS AND THESE
HAVE BEEN INCLUDED IN THE AFTERNOON TEMPO GROUPS. ALSO...WITH
DEWPOINTS AROUND 70...SOME PATCHY VALLEY FOG WILL BE POSSIBLE AGAIN
LATE TONIGHT...BUT SHOULD NOT AFFECT THE TAF SITES. WINDS WILL BE
LIGHT AND VARIABLE THROUGH THE NIGHT...BUT COULD BE BREEZY FROM THE
WEST SOUTHWEST DURING THE DAY TUESDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...KAS
LONG TERM....JJ
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
801 PM EDT MON JUL 23 2012
.SYNOPSIS...
HIGH PRESSURE BUILDS EAST FROM THE PLAINS THROUGH TUESDAY...AS A
SERIES OF WEAK DISTURBANCES TRACK FROM THE UPPER MIDWEST TO THE
EAST COAST. A COLD FRONT SWEEPS THROUGH THE REGION TUESDAY NIGHT
FOLLOWED BY HIGH PRESSURE BUILDING IN FROM THE NORTH WEDNESDAY.
ANOTHER COLD FRONT CROSSES THE MID ATLANTIC LATE IN THE WEEK.
&&
.NEAR TERM /THROUGH TUESDAY/...
SCT SHWRS/TSTMS CURRENTLY OVER THE PIEDMONT WILL SLOWLY SPREAD
EAST THIS AFTN INTO ERLY EVNG. LACK OF FORCING WILL BE A MAIN
INHIBITOR TOWARDS SVR THREAT AS BEST S/W ENERGY IS STILL OFF TO
THE NW OVER EASTERN OH SO ANY CONVECTION WILL BE MAINLY TRIGGERED
BY LEE TROF AND OUTFLOW BNDRYS. SPC HAS INCLUDED THE ENTIRE
REGION IN A SLGT RISK FOR SVR WX AS CONDITIONS ARE FAVORABLE FOR
ISO SVR STORMS DUE TO STEEP LO-LVL LAPSE RATES AND MLCAPE GREATER
THAN 2500 J/KG PER LATEST RAP ANALYSIS. 0-6 KM BULK SHEAR IS
FAIRLY WEAK (~20 KT) AND UNIDIRECTIONAL SO STORM ORGANIZATION WILL
BE LIMITED. MAIN THREATS ARE DAMAGING WIND GUSTS AND HEAVY
RAINFALL. ACTIVITY SHOULD DECREASE THIS EVNG FOLLOWING THE LOSS OF
DAYTIME HEATING. FOG MAY BE POSSIBLE IN SOME AREAS BUT DEBRIS
CLOUDINESS WILL LIMIT LOW CLOUD/FOG FORMATION. ERLY MRNG LOW TEMPS
IN THE LOW TO MID 70S.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
BETTER CHC FOR STRONG STORMS ON TUE AS A POTENT MID-LVL S/W
EMBEDDED WITHIN NW FLOW ALOFT PUSHES THROUGH THE MID ATLANTIC
ALONGSIDE A PREFRONTAL TROF IN THE AFTN AND EVNG HRS.
THERMODYNAMIC FIELDS ARE AGAIN CONDUCIVE TO SVR WX...WITH 0-6 KM
BULK SHEAR GREATER THAN MON (30-35 KT). MAIN THREATS ARE AGAIN
HEAVY RAIN AND DAMAGING WINDS. WILL CONTINUE TO REFLECT SEVERE WX
THREAT IN HWO.
OTHER BIG STORY WILL BE HOTTER TEMPS...EXACERBATED BY COMPRESSIONAL
HEATING AHEAD OF AN APPROACHING COLD FRONT. THE EVENTUAL ONSET OF
CONVECTIVE ACTIVITY WILL CAST SOME UNCERTAINTY ON ACTUAL MAXIMA.
FORECAST MAXIMA ATTM GENERALLY IN THE MID 90S TUE...AND WITH HEAT
INDICES CURRENTLY FORECASTED TO MAX OUT AROUND 101-105...HEAT
ADVISORY CRITERIA WILL BE APPROACHED IN SOME AREAS. WILL HOLD OFF
FOR NOW ON ANY HEAT HEADLINES ACROSS THE FA AS CONFIDENCE FOR
REACHING CRITERIA IS STILL LOW DUE TO CLOUDS...PRECIP
POTENTIAL...AND DOWNWARD TREND IN HI TEMPS WITH MUCH OF TDY`S 12Z
GUIDANCE.
AFOREMENTIONED ADVANCING S/W TROF ON TUE WILL PULL THE COLD FRONT
THROUGH THE REGION TUE NGT/ERLY WED...USHERING IN DRIER
CONDITIONS WED AS DEWPTS DROP INTO THE L0W 60S IN MOST SPOTS.
HIGHS WILL ONLY BE IN THE UPR 80S TO LWR 90S. S/SW FLOW RETURNS
THU AHEAD OF THE NEXT FRONTAL SYSTEM WITH TEMPS REACHING THE MID
90S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
BROAD UPR LVL TROUGH TO RMN ANCHOR OVR THE NE CONUS W/ RIDGE OVR THE
NATIONS MIDSECTION FOR THE EXTENDED PD...RESULTING IN NWLY FLO INTO
THE MDATLC RGN. TIMING SYSTEMS IN SUCH A PATTERN DIFFICULT FROM THIS
FAR OUT. CDFNT TO CROSS THE RGN THU NGT INTO FRI...THEN LINGER OVR
THE CAROLINAS. SERIES OF WK AREAS OF SFC LO PRES FCST TO TRACK ALG
THE LINGERING BNDRY. OVRALL...MNLY PCLDY W/ PRIMARILY DIURNAL
POPS...ESP FRI AND AGN SAT. TEMPS AVGG A FEW DEGS F ABV NRML (THOUGH
RMNG LARGELY W/ +1 STANDARD DEVIATION OF NRML). HI TEMPS IN THE
L/M90S FRI...U80S TO L90S SAT AND SUN...AND 80S MON. LO TEMPS IN THE
M/U70S THU NGT/FRI NGT...AND L/M70S SAT NGT/SUN NGT.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 00Z...SCATTERED SHOWERS EXTEND FROM THE CITY OF RICHMOND
SOUTH TO THE NC BORDER MOVG SE. SOME ISOLATED THUNDER WITH THE
RAIN BUT MOST OF THE PRECIP HAS STRATIFIED. MOST OF THE PRECIP
RESULT OF A SFC TROF MOVG ACROSS THE CWA. THE TROF WILL MOVE TO
THE COAST BEFORE MIDNIGHT AND MOST OF THE PRECIP SHOULD BE
DIMINISHED. WNDS WILL BE W-NW OVERNIGHT. CIG AND VSBY RESTRICTIONS
WILL BE LIMITED DUE TO W-NW FLOW SO GENERALLY VFR CONDS EXPECTED
THRU THE OVERNIGHT. VFR AT TIMES. CUMULUS SHOULD CLEAR BY LATE
THIS EVENING.
OUTLOOK...CHANCES FOR CONVECTION RETURN TUESDAY AFTN AS A COLD
FRONT APPROACHES. FROM WEDNESDAY THROUGH FRIDAY...CONDITIONS WILL
BE MAINLY DRY AND VFR.
&&
.MARINE...
NO SCA UFN. WNDS MNLY SSW TNGT INTO TUE MRNG BCMG W. FNTL BNDRY XPCD
TO DROP SE ACRS THE WTRS FM LT TUE AFTN THROUGH EVE. SPDS TO RMN AOB
15 KT THROUGH TUE. A PD OF NNW WNDS XPCD POST FNT TUE NGT INTO WED.
CONFIDENCE RMNS LO RIGHT NOW ON ABT OF LLVL SURGE FM THE N DVLPS
(I.E., ENHANCED WINDSPEEDS/PSBL HEADLINE). MNLY CAPPED SPDS AT ABT
15 KT. MODELS HAVE WNDS BMCG SSW AGN BY THU.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAS/MAM
NEAR TERM...MAS
SHORT TERM...MAS
LONG TERM...ALB
AVIATION...JEF/LSA
MARINE...ALB
AS WITH PREVIOUS FORECAST DISCUSSIONS...IT LOOKS AS THOUGH AN
ACTIVE WEATHER PATTERN WILL DEVELOP TUE AND LAST INTO WED AS A
SERIES OF SHRTWV/S AND A STRONG THERMAL GRADIENT DEVELOPS ALONG
THE MN/IA BORDER. DUE TO HIGH PRECIPITABLE WATER VALUES...THERE
SHOULD BE SEVERAL ROUNDS OF HEAVY RAINFALL SOMETIME
TUE/WED...BEFORE TAPERING OFF LATE WED/THU AS THE COOLER AND DRIER
AIR FILTERS SOUTHWARD ACROSS THE UPPER MIDWEST. ONE DIFFERENCE IN
THE EXTENDED PERIOD IS THE ORIENTATION OF THE MAIN JET
STREAM...WHICH HAS BEEN WELL NORTH ACROSS OUR REGION. AS THE
STRONGER SYSTEM MOVES ACROSS THE AREA THU...THE PATTERN BEGINS TO
CHG WITH THE JET SAGGING SOUTHWARD BY THE END OF THE WEEK.
ALTHOUGH THICKNESS VALUES DUE BEGIN TO RISE BY LATE NEXT
WEEKEND...THE MEAN FLOW IS MUCH FASTER ACROSS THE UPPER
MIDWEST...WITH THE JET STREAM FURTHER SOUTH THAN IN PREVIOUS
WEEKS. SO...A MORE ACTIVE WEATHER PATTERN IS BECOMING MORE LIKELY
NEXT WEEK /THE BEGINNING OF AUGUST/ ALONG WITH MORE SEASONABLE
TEMPS. ..JLT..
&&
.AVIATION.../18Z TAF ISSUANCE/
THE LIGHT SHOWERS HAD ENDED ACROSS THE REGION...WITH A FEW HIGH
CLOUDS STILL OVERHEAD. COULD SEE SOME REDEVELOPMENT ACROSS THE FAR
SOUTH...BUT THIS SHOULD NOT IMPACT THE TAF SITES. MAIN CONCERN
WILL BE THE POTENTIAL FOR SOME FOG OVERNIGHT AS A WARM AND HUMID
AIRMASS REMAINS IN PLACE. CURRENTLY DATA SUGGESTS THAT KNRH AND
KEAU WILL BE MOST FAVORED SITES FOR FOG. TOMORROW MID LEVEL CLOUDS
SHOULD MOVE OVERHEAD...WITH A FEW SHOWERS POSSIBLE LATE IN THE
AFTERNOON.
KMSP...LIGHT SOUTHERLY WINDS SHOULD PREVAIL TODAY...WITH VARIABLE
WINDS OVERNIGHT. COULD SEE SOME MVFR VISBYS DURING THE EARLY
MORNING HOURS...BUT OPTIMISTIC THAT THEY WILL STAY VFR. TOMORROW A
THIN MID LEVEL CLOUD DECK WILL MOVE IN FROM THE WEST...WITH A FEW
SHOWERS POSSIBLE DURING THE LATE AFTERNOON HOURS.
/OUTLOOK/
TUESDAY...VFR/MVFR WITH TSRA POSSIBLE. WINDS E AT 10KTS.
WEDNESDAY...VFR/MVFR WITH TSRA POSSIBLE. WINDS E AT 10KTS.
THURSDAY...VFR WITH TSRA POSSIBLE. WINDS SW AT 10KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JLT/JRB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
105 AM CDT SUN JUL 22 2012
.UPDATE...
06Z AVIATION ADDED BELOW.
&&
.DISCUSSION...
/ISSUED 223 PM CDT SAT JUL 21 2012/
THE 00Z AND 12Z ECMWF GIVE SOME HINTS OF A POSSIBLE CHANGE IN THE
LARGE SCALE PATTERN BY NEXT WEEKEND... BUT THERE IS FAR FROM A
CONSENSUS IN THE LONG RANGE GUIDANCE. THE GFS AND MANY OF THE GEFS
AND ECMWF ENSEMBLE SOLUTIONS... AS WELL AS THE CANADIAN...
CONTINUE TO HANG ONTO THE BASIC THEME OF MAINTAINING A BROAD UPPER
RIDGE OVER MUCH OF THE CENTRAL CONUS AND SOUTH CENTRAL CANADA
THROUGH THE FORESEEABLE FUTURE. SHOULD THE ECMWF PAN OUT... WE
WOULD SEE RIDGING RETROGRADE A BIT TO THE WESTERN SIDE OF THE
CONTINENT... WITH GOOD TROUGHING OVER EASTERN CANADA HELPING TO
BRING MORE CONSISTENT NEAR AND PERHAPS BELOW NORMAL TEMPERATURES
INTO OUR VICINITY. WE STILL LOOK TO BE NEAR THE PERIPHERY OF THE
UPPER RIDGE THROUGH MOST OF THE UPCOMING WEEK REGARDLESS OFF
WHETHER A SHIFT EVENTUALLY OCCURS... AND AS SUCH WILL CONTINUE TO
SEE WARM TEMPERATURES BALANCED WITH PERIODIC CHANCES FOR SHRA/TSRA
AS THE BAROCLINIC ZONE FLIRTS WITH OUR AREA.
TONIGHT AND SUNDAY...WEAK SFC FRONT EXTENDING E-W OVER CENTRAL MN
INTO NRN WI WILL CONTINUE TO DRIFT S OVERNIGHT INTO SUN...EVENTUALLY
SETTLING NEAR OR JUST S OF THE IA/MN BORDER INTO SRN WI. MOST OF THE
SHWRS/TSTMS AHEAD OF THIS FRONT OVER SRN MN HAS DISSIPATED AND
SHIFTED OFF TO THE S. CLOUDS HAVE THINNED OUT OVER MUCH OF
NRN-CENTRAL PORTIONS OF THE COVERAGE AREA AND THIS TREND WILL
CONTINUE TONIGHT AS THE FRONT MOVES S. MOST LOCATIONS WILL END UP
MOSTLY CLEAR TNGT. THE ONLY EXCEPTION WILL BE FAR SRN MN IN CLOSE
PROXIMITY TO THE FNT WHERE ISOLD SHWRS/TSTMS ARE STILL POSSIBLE.
EVEN WITH THE FNT DROPPING S...VIRTUALLY NO CHANGE IN AIRMASS IS
EXPECTED TNGT SO WITH WINDS GOING LIGHT TO CALM...NO TEMP ADVECTION
IS EXPECTED. THEREFORE...WILL LOOK FOR LOWS SUN MORNING SIMILAR TO
WHAT WAS RECORDED THIS MORNING...IN THE LOWER 60S TO LOWER 70S. HIGH
TEMPS ON SUN COULD BE A LITTLE TRICKY DEPENDING ON THE EXTENT OF
CLOUD COVER. UNDER FULL SUN AND MIXING...HIGHS COULD EASILY REACH
THE MID 90S WITH 850-925MB TEMPS FORECAST TO BE HIGHER SUNDAY THAN
TDA...AND AREAS WITHOUT CLOUDS TDA HAVE ALREADY HIT THE MID 80S.
HOWEVER...S AND SE PORTIONS OF THE CWFA WILL SEE ADDITIONAL CLOUD
COVER THAN THE REST OF THE CWFA...LEADING TO SLIGHTLY COOLER TEMPS.
THAT SAID...AM STILL LOOKING FOR HIGHS ARND 90 DEGREES...ESPECIALLY
AS WINDS SWING AROUND TO HAVE A MORE PRONOUNCED SLY COMPONENT.
TOMORROW NIGHT AND MONDAY LOOK LIKE THEY SHOULD BE WARM AND DRY
OVER MOST OF THE AREA... ALTHOUGH SOME PCPN COULD SNEAK INTO THE
SOUTH AND SOUTHWEST ON MONDAY AS ANOTHER SHORTWAVE WORKS AROUND
THE UPPER RIDGE AND INTERACTS WITH THE STALLED FRONTAL BOUNDARY.
THE TRICK OF COURSE WILL CONTINUE TO BE FIGURING OUT EXACTLY WHERE
THAT BOUNDARY WILL BE... AND SINCE EACH ROUND OF MCS AND
ASSOCIATED SHRA/TSRA CAN SHIFT ITS LOCATION... THE CHANCES ON
MONDAY COULD BE FARTHER NORTH... SOUTH... OR EAST. BUT FOR NOW...
THE CONSENSUS OPINION FROM THE ECMWF... NAM... AND SREF WOULD BE
TO HIGHLIGHT SOME POTENTIAL OVER THE SOUTHWEST INTO THE SOUTH
CENTRAL PORTION OF THE AREA... BEGINNING ON MONDAY THEN SHIFTING
OVER MUCH OF THE AREA MONDAY NIGHT INTO TUESDAY NIGHT AS A MORE
SIGNIFICANT SHORTWAVE WORKS IN AND THE FRONTAL BOUNDARY BECOMES
MORE ACTIVE. THERE MAY BE SOME POTENTIAL FOR HEAVY RAIN GIVEN THE
POSSIBILITY OF TRAINING PCPN MONDAY NIGHT THROUGH TUESDAY... BUT
IT/S DEFINITELY TOO EARLY TO PIN DOWN THAT POSSIBILITY BOTH FROM
AND OCCURRENCE AND PARTICULARLY FROM A LOCATION PERSPECTIVE.
HOWEVER... IT WILL BE SOMETHING TO KEEP AN EYE ON OVER THE NEXT
DAY OR TWO... SINCE IT MIGHT NEED TO BE HIGHLIGHTED IN LATER
FORECASTS AND OUTLOOK PRODUCTS. THE POTENTIAL COULD CERTAINLY
PERSIST THROUGH INTO WEDNESDAY NIGHT SINCE THE OVERALL BIG PICTURE
CHANGES LITTLE... UNTIL WE EVENTUALLY SEE A SUFFICIENTLY
SIGNIFICANT UPPER WAVE ARRIVE BY THURSDAY TO SHIFT THINGS OUT OF
HERE FOR A TIME. HOWEVER... THE PREDICTABILITY OF THE BOUNDARY
POSITION AND INSTABILITY/MOISTURE AXIS DECREASES MARKEDLY AFTER
TUESDAY NIGHT SINCE MUCH WILL DEPEND ON HOW THINGS EVOLVE MONDAY
NIGHT AND TUESDAY... AND AS A RESULT THE NWP SOLUTIONS VARY QUITE
A BIT BY MID-WEEK WITH RESPECT TO THE DETAILS. BUT... IF WE MANAGE
TO MAINTAIN THE UPPER RIDGE AND BAROCLINIC ZONE IN A REASONABLY
SIMILAR LOCATION THROUGH MIDWEEK... SOME LOCATIONS COULD
DEFINITELY SEE SOME SIGNIFICANT THREE OR FOUR DAY PCPN TOTALS. THE
MOST LIKELY AREA AT THIS POINT IN TIME... BASED ON MODEL CONSENSUS
OF THE LARGE SCALE MASS/MOISTURE FIELDS AND PERSISTENCE... WOULD
BE NEAR THE I-94 CORRIDOR.
KEPT CHANCES FOR PCPN IN FOR THURSDAY AS THE MAIN UPPER WAVE
FINALLY WORKS THROUGH THE REGION AND PUSHES THE BAROCLINIC ZONE
SOUTH/EAST OF US. ALSO LINGERED SOME CHANCES INTO FRIDAY OVER THE
EASTERN PORTION OF THE CWFA WHERE A SECONDARY COLD FRONTAL
BOUNDARY MAY HAVE ENCOUNTER ENOUGH LINGERING INSTABILITY TO KICK
OFF SOME SHRA/TSRA GIVEN THE PRESENCE OF THE COOLER TEMPERATURES
ALOFT. DRIED THINGS OUT FOR FRIDAY NIGHT AND SATURDAY WITH THE
EXPECTATION OF A SURFACE HIGH AND SOME COOL/DRY ADVECTION FROM THE
NORTH. OVERALL... CONFIDENCE IN THE FORECAST DETAILS DECREASES
MARKEDLY AFTER TUESDAY... SO IDEAS BY FRIDAY AND SATURDAY SHOULD
REALLY BE TAKEN WITH THAT IN MIND. HOWEVER... THERE IS A
REASONABLE CONSENSUS IN THE OVERALL IDEA OF PUSHING THE BAROCLINIC
ZONE OUT OF THE AREA DURING THE SECOND HALF OF THE WEEK... ITS
JUST A QUESTION OF WHEN AND HOW FAR. AFTER THAT... IT BECOMES A
QUESTION OF WHETHER IT WILL BE GONE FOR A WHILE AS SUGGESTED BY
THE ECMWF OR WHETHER IT WILL REASSERT ITSELF QUICKLY AS SUGGESTED
BY THE GFS.
&&
.AVIATION.../06Z TAF ISSUANCE/
MAIN CONCERN THIS TAF PERIOD DEALS WITH EVOLUTION OF CONVECTION
OVERNIGHT. THIS CONVECTION IS SITTING ON THE NOSE OF A LLJ AND
FULLY EXPECT THIS ACTIVITY FOLLOW THIS FORCING FEATURE ACROSS THE
AREA. SEEING TWO CAMPS FOR THE EVOLUTION OF THE LLJ OVERNIGHT.
THE GFS/SREF SHOW THE LLJ BASICALLY LAYING OVER ALMOST DUE EAST
OVERNIGHT...TAKING BULK OF ACTIVITY SOUTH OF ALL BUT RWF.
NAM/ECMWF/RAP SHOW THE LLJ COMING A BIT FARTHER NORTH BEFORE
TURNING EAST...ALLOWING FOR THE CONVECTIVE POTENTIAL TO WORK INTO
MSP AND POSSIBLY EVEN AS FAR NORTH AND EAST AS RNH. WITH THE HRRR
SUPPORTING THE LATER SOLUTION...CONTINUED THE MENTION OF SHRA AT
MSP AFTER 10Z. AS WITH THE PAST COUPLE OF NIGHTS...ANY CONVECTION
OUT THERE SHOULD QUICKLY DIMINISH AFTER 15Z AS LLJ WEAKENS AND
SHIFTS EAST. ANY CONVECTION THIS AFTERNOON SHOULD BE CONFINED TO
ERN WI AND THE ARROWHEAD WHERE BETTER LOW LEVEL FORCING WILL
RESIDE. FOR TONIGHT...ALL MODELS CONTINUE TO SHOW A BRIEF BREAK
FROM THE NOCTURNAL LLJ...SO NOT ANTICIPATING A THIRD NIGHT IN A
ROW OF OVERNIGHT CONVECTION.
OTHER CONCERN FOR THE REST OF THIS EVENING WILL BE THE FOG
POTENTIAL...ESPECIALLY IN WI. SFC HIGH IS CURRENTLY CENTERED OVER
THE MI/WI BORDER. DEWPOINT DEPRESSIONS GENERALLY 3 DEGREES OR
LESS...AND WITH CALM WINDS AND CURRENTLY A MOSTLY CLEAR SKY...FG
COULD BE AN ISSUE /SEE 1/2SM VIS AT RPD/. HOWEVER...CLOUD COVER
STREAMING IN FROM THE WEST SHOULD HELP LIMIT THE FOG. IS A LOW
CONFIDENCE FOG SITUATION THERE...SO WILL CONTINUE TO MONITOR FOR
POSSIBLE AMDS THROUGH THE EVENING.
KMSP...BASED ON REASONING ABOVE...DO EXPECT A BAND OF SHRA/TSRA TO
MOVE ACROSS THE FIELD IN THE 11-13Z WINDOW. WILL BE TROPICAL TYPE
SHOWERS WITH THIS ACTIVITY...SO IFR VSBYS WILL POSSIBLE IF A CORE
DOES GO OVER THE FIELD...OTHERWISE ITS VFR CONDS FOR THIS TAF
PERIOD. AS WITH YESTERDAY...WILL SEE A RAPID IMPROVEMENT IN SKY
CONDITIONS IN THE MORNING...WITH MOSTLY SUNNY SKIES BY THE
AFTERNOON. FOR WINDS...WEAK SFC LOW CURRENTLY OVER SE SODAK IS
PEGGED BY THE HRRR TO MOVE INTO SW MN THIS MORNING...WITH GRADIENT
TIGHTENING THIS MORNING. NET RESULT OF THIS WOULD BE TO CREATE A
BIT STRONGER SOUTH WIND THAN CURRENTLY INDICATED. EXTREME CASE FOR
WINDS TODAY WOULD BE A 18012G21KT TYPE WIND AT 18Z...AS NAM BUFR
SOUNDING WOULD INDICATE.
//OUTLOOK...
MONDAY...VFR EXPECTED. WINDS LGT/VRB BECOMING N 5 KT.
MONDAY NIGHT THROUGH WEDNESDAY...MVFR CONDITIONS POSSIBLE DUE TO
SCATTERED SHRA/TSRA. WINDS NE TO E 5-10 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
TRH/MPG
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
818 PM EDT MON JUL 23 2012
.SYNOPSIS...
SCATTERED SHOWERS AND THUNDERSTORMS CAN BE EXPECTED ACROSS THE
AREA THROUGH TONIGHT AHEAD OF A COLD FRONT MOVING SOUTHEAST TOWARD
THE AREA FROM ONTARIO. A FEW STORMS COULD BE SEVERE THROUGH THIS
EVENING. HIGH PRESSURE WILL BRING A RETURN TO DRY WEATHER TUESDAY
THROUGH WEDNESDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
8 PM UPDATE...
UPDATE TO THE GRIDS. ADJUSTED TO CURRENT. MIN TEMPS UPPED. WITH
CLOUDS AND CONVECTION MOST OF THE NIGHT TEMPERATURES WILL FALL
LITTLE. ALSO DEWPOINT TEMPERATURES ARE IN THE MID AND UPPER 60S.
AND MOS GUIDANCE HAS BEEN TOO COLD FOR THE LAST SEVERAL DAYS.
THUNDERSTORMS EXITING THE SE COUNTIES BUT MORE THUNDERSTORMS
APPROACHING FROM THE NW AS IT CROSSES LAKE ONTARIO. UPPED POPS IN
THE NORTH. SEVERE WEATHER STILL OCCURRING IN ONEIDA ATTM.
PREVIOUS DISCUSSION...
SCATTERED THUNDERSTORMS CONTINUE THIS AFTERNOON ALONG AND AHEAD OF
A WEAK SURFACE TROUGH EXTENDING FROM CENTRAL NEW YORK SOUTH
THROUGH CENTRAL PENNSYLVANIA. SPC ANALYSIS INDICATES THAT MLCAPES
ACROSS THE REGION THIS AFTERNOON RANGE FROM 2000 TO 2500 J/KG.
DEEP LAYER (0-6 KM) SHEAR VALUES HAVE BEEN ONLY MARGINALLY
SUPPORTIVE OF ORGANIZED SEVERE WEATHER...ABOUT 25 TO 30 KTS...
THROUGH MID- AFTERNOON. HOWEVER THIS ENVIRONMENT HAS BEEN
SUFFICIENT TO GENERATE SOME SEVERE STORMS.
A STRONG MID-UPPER LEVEL WIND SPEED MAX WILL APPROACH THE AREA LATE
THIS AFTERNOON THROUGH THIS EVENING INCREASING THE WIND SHEAR
SIGNIFICANTLY. 0-6 KM SHEAR VALUES ARE FORECAST TO INCREASE TO
AROUND 40 KTS BY 03Z. STORMS MAY INCREASE IN INTENSITY AS THIS
SPEED MAX APPROACHES THE AREA LATE THIS AFTERNOON... THEN EXPECT
THUNDERSTORM ACTIVITY TO DIMINISH FOR A PERIOD THIS EVENING AS THE
DRY AIR ALOFT SWEEPS OVER THE AREA INHIBITING THE CONVECTION. THIS
BRIEF LULL MAY BE FOLLOWED BY ANOTHER ROUND OF SHOWERS AND STORMS LATER
THIS EVENING INTO THE OVERNIGHT PERIOD AS A SURFACE COLD FRONT
APPROACHES FROM THE NORTHWEST. RUC SOUNDINGS INDICATE THAT CAPES
REMAIN ABOVE 1000 J/KG UNTIL WELL AFTER MIDNIGHT AND WITH STRONG
SHEAR IN PLACE ANY STORMS THAT CAN DEVELOP ALONG THE COLD FRONT
COULD ONCE AGAIN BECOME SEVERE. STORMS SHOULD FINALLY DIMINISH
ACROSS THE AREA LATE TONIGHT AS THE COLD FRONT PASSES SOUTHEAST
OF THE AREA.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY/...
QUIET WEATHER RETURNS THROUGH THIS PERIOD. HIGH PRESSURE BUILD
SOUTHEAST ON TUESDAY BRINGING DRY COOLER WEATHER WITH GUSTY
NORTHWEST WINDS. WEDNESDAY WILL BE DRY AND SEASONABLY WARM WITH
HIGH PRESSURE MOVING ACROSS THE MID-ATLANTIC.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
AFTER A BEAUTIFUL WEDNESDAY...CONDITIONS WILL QUICKLY TAKE A TURN
FOR THE WORSE WEDNESDAY NIGHT INTO THURSDAY AS THE FIRST OF
SEVERAL DISTURBANCES BARE DOWN ON THE REGION. AS HIGHLIGHTED IN
RECENT DAYS...A SERIES OF UPPER-LEVEL SHORTWAVES DIVING SOUTHEAST
FROM A BUILDING RIDGE ACROSS THE NORTHERN ROCKIES COMBINED WITH A
NEARLY STATIONARY UPPER LOW ACROSS NORTHERN QUEBEC WILL RESULT IN
A STAGNANT UPPER-LEVEL PATTERN. UNDER THIS SCENARIO...VERY SLOW
MOVING SHORTWAVE TROUGHS CUTOFF FROM THE MAIN UPPER-LEVEL WIND
FIELDS WILL GRADUALLY MOVE SOUTHWEST TOWARDS OUR REGION IN
WEST-NORTHWEST FLOW ALOFT.
FCST MODELS ALL AGREE THAT THE FIRST ROUND OF SHWRS WILL BE UPON
US BY 12Z THU AS STRONG L0W-LEVEL JET WINDS OF ROUGHLY 40 KTS
ASCEND A NORTHWARD LIFTING WARM FRONT. ADDITIONAL FORCING WILL BE
PROVIDED BY STRONG UPPER-LEVEL DIVERGENCE ALOFT AS REGION WILL
RESIDE UNDER THE FAVORABLE LEFT ENTRANCE REGION OF AN
ANTICYCLONICALLY CURVED JET STREAK ROUNDING THE BASE OF THE
AFOREMENTIONED UPPER LOW ACROSS NORTHERN QUEBEC. CURRENTLY MODELS
TAKE THE SFC LOW EAST ACROSS WESTERN AND CENTRAL NY THROUGH THE
DAY ON THURSDAY...WITH THE HEAVIEST PRECIP AXIS SUGGESTED JUST NORTH
OF OUR FCST AREA ACROSS NORTHERN NY AND SOUTHERN ONTARIO. THAT
SAID...IF CONDITIONS WORK OUT AS ADVERTISED...MUCH NEEDED RAINFALL
WILL OCCUR ACROSS THE NORTHERN FINGER LAKES AND WESTERN MOHAWK
VALLEY.
BEYOND THIS...THE GFS QUICKLY EXITS THE SFC LOW STAGE RIGHT WHICH
WOULD SET UP A TEMPORARY LULL ON FRIDAY IN ADVANCE OF NEXT UPPER
SHORTWAVE DISTURBANCE. THE ECMWF ON THE OTHER HAND SUGGEST THE SFC
LOW WILL STALL OVER THE REGION WHICH WOULD LEAD TO CONTINUED RAIN
CHANCES RIGHT THROUGH THE END OF THE WEEK. QUICK LOOK AT THE
CANADIAN-CMC MODEL FAVORS THE SLOWER SOLUTION AS OFFERED BY THE
ECMWF AND THUS WILL KEEP CHC POPS THROUGH FRIDAY. AS MENTIONED
ABOVE...NEXT MAJOR TROUGH TO ENTER THE REGION BY SATURDAY WHICH
WILL BRING RENEWED CHANCES FOR SHWRS AND STORMS BEFORE CONDITIONS
BEGIN TO DRY OUT BY SUNDAY AS UPPER TROUGH PULLS AWAY FROM THE
REGION. EXPECT NEAR TO BELOW AVERAGE TEMPS THROUGH THE PERIOD
WITH CONTINUED RAIN CHANCES AND ABUNDANT CLOUD COVER ALOFT.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
730 PM UPDATE...
THUNDERSTORMS MOVED OUT OF KBGM AND KAVP BUT ARE IN KRME AND KSYR.
THIS WILL CONTINUE FOR THE NEXT 2 HOURS. THERE WILL BE A GAP THEN
THUNDERSTORMS OVER LAKE ONTARIO WILL MOVE IN TOWARDS 4Z. CLOUDS
WILL CONTINUE OVER THE AREA TONIGHT INTO TUESDAY. WITH THE CLOUDS
AND LOW LEVEL WINDS AROUND 20 KTS VALLEY FOG SHOULDN`T BE AN
ISSUE. TUESDAY VFR CIGS. OBSERVATIONS FROM KAVP ONLY HAVE
PRESSURE.
SW WINDS AT 10 KTS DROPPING TO 5 TO 10 KTS. DURING THE OVERNIGHT
WINDS SHIFT TO THE WEST THEN THE NW WITH A COLD FRONTAL PASSAGE.
TUESDAY BY 15Z WINDS INCREASE TO 10 TO 15 KTS WITH GUSTS TO 20.
OUTLOOK...
TUE NGT...POSSIBLE MVFR/IFR VSBY RESTRICTIONS...ESPECIALLY AT ELM.
WED...VFR.
WED NGT TO SAT...RESTRICTIONS PSBL IN SHRA/TSRA.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MSE
NEAR TERM...MSE/TAC
SHORT TERM...MSE/SLI
LONG TERM...CMG
AVIATION...TAC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1058 AM EDT SUN JUL 22 2012
.SYNOPSIS...
A WEAK TROUGH WILL MAKE ITS WAY INTO THE AREA THIS
AFTERNOON...BRINGING A CHANCE FOR SOME SHOWERS AND POSSIBLY A
THUNDERSTORM WITH IT...ESPECIALLY TO THE FINGER LAKES AND SOUTHERN
TIER REGIONS. A STRONGER TROUGH WILL MOVE THROUGH ON MONDAY
AFTERNOON...BRINGING YET ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS. HIGH PRESSURE WILL BUILD BACK INTO THE AREA FOR THE
MIDDLE OF THE WEEK..
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1030 AM UPDATE... THE VSBL SAT LOOP SHOWS AN EXPANDING AREA OF LWR
CLDS ATTM ACRS NE PA...INTO PTNS OF NY`S SRN TIER. WE DO EXPECT
THAT THIS CLD MASS...IN GENERAL...WILL EVOLVE INTO AN OPEN
CELLULAR CU FIELD BY EARLY AFTN. OTHWS...SUNNY SKIES WILL GIVE WAY
TO SCT-BKN MID-LVL CLDS AND SOME CU BY ARND 18Z...AS MOIST ADVECTS
IN FROM THE W. THE UPSHOT OF ALL THIS...IS THAT PTLY SUNNY SKIES
CAN BE ANTICIPATED AREA-WIDE THIS AFTN.
AS FAR AS CONVECTIVE POTENTIAL GOES...A WEAK MID-LVL TROUGH (SEEN
BEST ARND 700 MB) WILL BE DRIFTING ESEWD INTO WRN/CNTRL NY LTR
THIS AFTN INTO THE EVE...COUPLED WITH VERY WEAK LOW-LVL WAA. THIS
COMBO SHOULD HELP TRIGGER ISOLD-SCTD SHRA/TSRA...MAINLY ALG AND W
OF THE I-81 CORRIDOR. OVERALL...SVR POTENTIAL LOOKS LOW...AS MRNG
SNDGS SHOW SOME CINH IN THE 700-800 MB LYR AT BOTH ALY/BUF...WHICH
SHOULD SLOW PARCEL ACCELERATIONS A BIT (EVEN PROJECTED SB CAPE
VALUES ARE ONLY ARND 1000 J/KG ANYWAY). ALSO...DEEP-LYRD SHEAR IS
FAIRLY WEAK (20 KT OR SO IN THE LWST 6 KM).
BASED ON 925-850 MB TEMPS AT 12Z...AND ANTICIPATED WEAK THERMAL
ADVECTIONS...OUR FCST MAX TEMPS LOOK DECENT...AND ONLY VERY MINOR
CHGS WERE MADE.
PREV DISC... 630AM UPDATE...MODELS CONTINUE TO SHOW THE
FRONT/TROUGH FALLING APART AS IT REACHES THE CWA SOMETIME AFTER
MID DAY. THE HRRR IS A LITTLE FASTER, BUT APPEARS TO BE ALREADY
OVERDOING PRECIPITATION THIS MORNING. EVEN SO, IT SHOWS ONLY SOME
SHOWERS ALONG THE WESTERN CWA BORDER AND THEN BREAKING UP LATER
TODAY. DID DECIDE TO SPREAD POPS A LITTLE FURTHER EAST THIS
AFTERNOON, BUT REALLY DID NOT RAISE THEM ABOVE THE LOW END CHC
POPS THAT WERE ALREADY THERE. THERE IS JUST GREAT UNCERTAINTY WITH
THIS FORECAST, AS THERE IS UNCERTAINTY IN REGARDS TO THE STRENGTH
AND EXACT TIMING OF THE TROUGH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
THE TROUGH, OR WHAT IS LEFT OF IT, SHOULD STALL IN THE VICINITY OF
THE CWA. THIS KEEPS A MENTION OF SHOWERS AND STORMS IN THE
FORECAST SUNDAY NIGHT. POPS INCREASE QUITE A BIT FOR MONDAY AS A
MORE VIGOROUS SHORT WAVE AND A PRE- FRONTAL TROUGH APPROACH THE
REGION. THE MAIN COLD FRONT WILL MOVE THROUGH MONDAY NIGHT, WHICH
WILL KEEP CONVECTION GOING THROUGH THE NIGHT AND INTO TUESDAY MORNING,
ALBEIT LOWER POPS WITH THE LOSS OF DAYTIME HEATING. HIGH PRESSURE
WILL QUICKLY TRY TO BUILD IN BEHIND THIS FRONT, BRINGING A HALT TO
SHOWERS BY LATE TUESDAY AFTERNOON OR EARLY TUESDAY EVENING.
HIGH TEMPERATURES WILL BE PERSISTENT FROM SUNDAY THROUGH TUESDAY,
REACHING INTO THE LOW TO MID 80S, TO POSSIBLY EVEN NEAR 90 TOWARDS
THE LAKE PLAIN. LOWS FOR MONDAY AND TUESDAY WILL ALSO BE
PERSISTENT, ON GETTING INTO THE MID 60S OVER MOST OF THE AREA.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
UPPER PATTERN DURING THIS TIME FRAME WILL BE DOMINATED BY DEEP
CLOSED LOW PRESSURE ACROSS EASTERN CANADA...WITH A BUILDING RIDGE
ACROSS THE AMERICAN/CANADIAN WEST. FAIR AND DRY WX EXPECTED AT THE
START OF THE EXTENDED PERIOD AS HIGH PRESSURE DIVES SOUTH FROM
SOUTHERN CANADA. WITH WEAK NORTHERLY FLOW EXPECTED...TEMPS WILL
HOVER JUST BELOW NORMAL FOR DAYTIME HIGHS UNDER MOSTLY SUNNY
SKIES. HIGH PRESSURE WILL EXIT STAGE RIGHT WEDNESDAY NGT IN
ADVANCE OF A SLOW MOVING DISTURBANCE APPROACHING FROM THE WESTERN
AND CENTRAL GREAT LAKES. FCST MODELS IN RECENT DAYS HAVE BEEN
SUGGESTING A SLOW MOVING EASTWARD PROGRESSING SHORTWAVE/CLOSED LOW
EMANATING FROM BUILDING HEIGHTS OUT WEST...HOWEVER RECENT MODEL
RUNS HAVE STRUGGLED WITH TIMING AND LOCATION OF SEVERAL FEATURES
TO INCLUDE SFC LOW AND ASSOCIATED FRONTAL BOUNDARY POSITIONS. THAT
SAID...MODELS APPEAR TO BE CONVERGING ON A SOLUTION THAT BRINGS
THE FIRST SFC LOW EAST ACROSS OUR AREA ON THU...WITH CONTINUED
UNSETTLED CONDITIONS THEN EXPECTED THROUGH THE DURATION OF THE
FCST PERIOD AS ADDITIONAL SFC WAVES INTERACT WITH A STALLED FRONT
ACROSS THE NORTHERN MID-ATLANTIC AND OHIO VLY REGIONS.
AFOREMENTIONED CLOSED LOW WILL EVENTUALLY BEGIN UNDERCUTTING
EASTERN CANADIAN UPPER LOW BY LATE WEEK...HOWEVER WITH ANY POLAR
STREAM WINDS DISPLACED WELL TO THE NORTH...SHORTWAVE ENERGY/UPPER
LOW APPROACHING FROM THE NORTHWEST WILL INCH ALONG EVER SO SLOWLY. THE
END RESULT WILL BE CONTINUED CHANCES FOR RA/STORMS THROUGH THE
NEXT WEEKEND WITH AT OR BELOW NORMAL TEMPS.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
UPSTREAM RADAR OBSERVATIONS INDICATING DEVELOPING CONVECTION THIS
HOUR JUST SOUTH OF TORONTO. FCST MODELS CONTINUE TO SUGGEST
SHWR/STORMS DEVELOPING FROM WEST TO EAST AS THE LATE
MORNING/AFTERNOON HRS PROGRESS AS A WEAK SURFACE TROUGH AND
SHORTWAVE MOVE OVER THE REGION. FOR NOW...OVERALL CONVECTIVE
CONVERGE REMAINS HIGHLY IN QUESTION AND BASED ON THIS...DO NOT
HAVE ENOUGH CONFIDENCE TO INCLUDE TSRA MENTION IN THE FCST. THAT
SAID...HAVE DECIDED TO INTRODUCE A TEMPO SHRA MENTION AT
ELM/BGM/ITH WHERE INSTABILITY WILL BE GREATEST. DAY SHIFT WILL HAVE
TO MONITOR TRENDS AND ADD OTHER TERMINALS IF DEEMED NECESSARY.
LGT SOUTHWEST WINDS EARLY ON WILL BECOME WESTERLY 5-10 KTS BY
MID/LATE AFTERNOON AS THE AFOREMENTIONED TROUGH PASSES. EXPECT
DEVELOPING CU BETWEEN 4-5 KFT LATER THIS MORNING AS DAYTIME
HEATING COMMENCES. BY TONIGHT...MODEL RH FIELDS SUGGEST INCREASING
AMOUNTS OF DRY AIR ALOFT WHICH WOULD LIKELY LEAD TO A GRADUAL
EROSION OF LINGERING LOW STRATUS FROM WEST TO EAST AND POTENTIAL
FOG DEVELOPMENT AT BOTH ITH AND ELM. FOG POSSIBILITIES WILL
INCREASE IF TERMINALS RECEIVE RAIN DURING THE DAY TODAY. FOR
NOW...HAVE MADE MVFR MENTION AT BOTH LOCATIONS.
OUTLOOK...
MON AND TUE...VFR...CHC MVFR IN SHWR/TSTM MAINLY IN THE AFTERNOON.
WED/THU...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...SLI
NEAR TERM...MLJ/SLI
SHORT TERM...SLI
LONG TERM...TAC
AVIATION...CMG
AREA FORECAST DISCUSSION...CORRECTED
NWS BINGHAMTON NY
655 AM EDT SUN JUL 22 2012
.SYNOPSIS...
A WEAK TROUGH WILL MAKE ITS WAY INTO THE AREA THIS
AFTERNOON...BRINGING A CHANCE FOR SOME SHOWERS AND POSSIBLY A
THUNDERSTORM WITH IT...ESPECIALLY TO THE FINGER LAKES AND SOUTHERN
TIER REGIONS. A STRONGER TROUGH WILL MOVE THROUGH ON MONDAY
AFTERNOON...BRINGING YET ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS. HIGH PRESSURE WILL BUILD BACK INTO THE AREA FOR THE
MIDDLE OF THE WEEK..
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
630AM UPDATE...MODELS CONTINUE TO SHOW THE FRONT/TROUGH FALLING
APART AS IT REACHES THE CWA SOMETIME AFTER MID DAY. THE HRRR IS A
LITTLE FASTER, BUT APPEARS TO BE ALREADY OVERDOING PRECIPITATION
THIS MORNING. EVEN SO, IT SHOWS ONLY SOME SHOWERS ALONG THE
WESTERN CWA BORDER AND THEN BREAKING UP LATER TODAY. DID DECIDE TO
SPREAD POPS A LITTLE FURTHER EAST THIS AFTERNOON, BUT REALLY DID
NOT RAISE THEM ABOVE THE LOW END CHC POPS THAT WERE ALREADY THERE.
THERE IS JUST GREAT UNCERTAINTY WITH THIS FORECAST, AS THERE IS
UNCERTAINTY IN REGARDS TO THE STRENGTH AND EXACT TIMING OF THE
TROUGH.
PREVIOUS DISCUSSION...A COLD FRONT WILL APPROACH THE AREA AND
BEGIN TO DISSIPATE INTO MORE OF A WEAK TROUGH. IT MAY BE ENOUGH TO
TRIGGER SOME ISOLATED TO SCATTERED SHOWERS OR THUNDERSTORMS OVER
THE CWA...WITH THE FINGER LAKES SEEING THE BEST CHANCE AT SEEING
CONVECTIVE DEVELOPMENT. CAPE VALUES OVER THE FINGER LAKES WILL BE
BETWEEN 1500 AND 2000 JOULES. LIS WILL BE AROUND -6. HOWEVER, THE
BEST CAPE WILL NOT OCCUR UNTIL LATE AFTERNOON INTO EARLY EVENING.
SO, IT MAY NOT BE ABLE TO CAPITALIZE ON DAYTIME HEATING. ALSO, MID
AND UPPER LEVEL LAPSE RATES ARE NOT IN FAVOR OF DEVELOPMENT. THE
MAIN LOW WILL BE PULLING WELL TO THE NORTH OF THE CWA, AS IT WILL
BE CENTERED NORTH OF THE HUDSON BAY. MODELS SHOW THE FRONT
CONTINUES TO DETERIORATE AS IT MOVES INTO THE CWA. BUT, STILL CAN
NOT RULE OUT SOME DEVELOPMENT LATER TODAY, SO AGAIN, CHC POPS IN
THE FINGER LAKE AND ISOLD IN THE REST OF THE AREA FOR NOW.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
THE TROUGH, OR WHAT IS LEFT OF IT, SHOULD STALL IN THE VICINITY OF
THE CWA. THIS KEEPS A MENTION OF SHOWERS AND STORMS IN THE
FORECAST SUNDAY NIGHT. POPS INCREASE QUITE A BIT FOR MONDAY AS A
MORE VIGOROUS SHORT WAVE AND A PRE- FRONTAL TROUGH APPROACH THE
REGION. THE MAIN COLD FRONT WILL MOVE THROUGH MONDAY NIGHT, WHICH
WILL KEEP CONVECTION GOING THROUGH THE NIGHT AND INTO TUESDAY MORNING,
ALBEIT LOWER POPS WITH THE LOSS OF DAYTIME HEATING. HIGH PRESSURE
WILL QUICKLY TRY TO BUILD IN BEHIND THIS FRONT, BRINGING A HALT TO
SHOWERS BY LATE TUESDAY AFTERNOON OR EARLY TUESDAY EVENING.
HIGH TEMPERATURES WILL BE PERSISTENT FROM SUNDAY THROUGH TUESDAY,
REACHING INTO THE LOW TO MID 80S, TO POSSIBLY EVEN NEAR 90 TOWARDS
THE LAKE PLAIN. LOWS FOR MONDAY AND TUESDAY WILL ALSO BE
PERSISTENT, ON GETTING INTO THE MID 60S OVER MOST OF THE AREA.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
UPPER PATTERN DURING THIS TIME FRAME WILL BE DOMINATED BY DEEP
CLOSED LOW PRESSURE ACROSS EASTERN CANADA...WITH A BUILDING RIDGE
ACROSS THE AMERICAN/CANADIAN WEST. FAIR AND DRY WX EXPECTED AT THE
START OF THE EXTENDED PERIOD AS HIGH PRESSURE DIVES SOUTH FROM
SOUTHERN CANADA. WITH WEAK NORTHERLY FLOW EXPECTED...TEMPS WILL
HOVER JUST BELOW NORMAL FOR DAYTIME HIGHS UNDER MOSTLY SUNNY
SKIES. HIGH PRESSURE WILL EXIT STAGE RIGHT WEDNESDAY NGT IN
ADVANCE OF A SLOW MOVING DISTURBANCE APPROACHING FROM THE WESTERN
AND CENTRAL GREAT LAKES. FCST MODELS IN RECENT DAYS HAVE BEEN
SUGGESTING A SLOW MOVING EASTWARD PROGRESSING SHORTWAVE/CLOSED LOW
EMANATING FROM BUILDING HEIGHTS OUT WEST...HOWEVER RECENT MODEL
RUNS HAVE STRUGGLED WITH TIMING AND LOCATION OF SEVERAL FEATURES
TO INCLUDE SFC LOW AND ASSOCIATED FRONTAL BOUNDARY POSITIONS. THAT
SAID...MODELS APPEAR TO BE CONVERGING ON A SOLUTION THAT BRINGS
THE FIRST SFC LOW EAST ACROSS OUR AREA ON THU...WITH CONTINUED
UNSETTLED CONDITIONS THEN EXPECTED THROUGH THE DURATION OF THE
FCST PERIOD AS ADDITIONAL SFC WAVES INTERACT WITH A STALLED FRONT
ACROSS THE NORTHERN MID-ATLANTIC AND OHIO VLY REGIONS.
AFOREMENTIONED CLOSED LOW WILL EVENTUALLY BEGIN UNDERCUTTING
EASTERN CANADIAN UPPER LOW BY LATE WEEK...HOWEVER WITH ANY POLAR
STREAM WINDS DISPLACED WELL TO THE NORTH...SHORTWAVE ENERGY/UPPER
LOW APPROACHING FROM THE NORTHWEST WILL INCH ALONG EVER SO SLOWLY. THE
END RESULT WILL BE CONTINUED CHANCES FOR RA/STORMS THROUGH THE
NEXT WEEKEND WITH AT OR BELOW NORMAL TEMPS.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
UPSTREAM RADAR OBSERVATIONS INDICATING DEVELOPING CONVECTION THIS
HOUR JUST SOUTH OF TORONTO. FCST MODELS CONTINUE TO SUGGEST
SHWR/STORMS DEVELOPING FROM WEST TO EAST AS THE LATE
MORNING/AFTERNOON HRS PROGRESS AS A WEAK SURFACE TROUGH AND
SHORTWAVE MOVE OVER THE REGION. FOR NOW...OVERALL CONVECTIVE
CONVERGE REMAINS HIGHLY IN QUESTION AND BASED ON THIS...DO NOT
HAVE ENOUGH CONFIDENCE TO INCLUDE TSRA MENTION IN THE FCST. THAT
SAID...HAVE DECIDED TO INTRODUCE A TEMPO SHRA MENTION AT
ELM/BGM/ITH WHERE INSTABILITY WILL BE GREATEST. DAYSHIFT WILL HAVE
TO MONITOR TRENDS AND ADD OTHER TERMINALS IF DEEMED NECESSARY.
LGT SOUTHWEST WINDS EARLY ON WILL BECOME WESTERLY 5-10 KTS BY
MID/LATE AFTERNOON AS THE AFOREMENTIONED TROUGH PASSES. EXPECT
DEVELOPING CU BETWEEN 4-5 KFT LATER THIS MORNING AS DAYTIME
HEATING COMMENCES. BY TONIGHT...MODEL RH FIELDS SUGGEST INCREASING
AMOUNTS OF DRY AIR ALOFT WHICH WOULD LIKELY LEAD TO A GRADUAL
EROSION OF LINGERING LOW STRATUS FROM WEST TO EAST AND POTENTIAL
FOG DEVELOPMENT AT BOTH ITH AND ELM. FOG POSSIBILITIES WILL
INCREASE IF TERMINALS RECEIVE RAIN DURING THE DAY TODAY. FOR
NOW...HAVE MADE MVFR MENTION AT BOTH LOCATIONS.
OUTLOOK...
MON AND TUE...VFR...CHC MVFR IN SHWR/TSTM MAINLY IN THE AFTERNOON.
WED/THU...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...SLI
NEAR TERM...SLI
SHORT TERM...SLI
LONG TERM...TAC
AVIATION...CMG
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
629 AM EDT SUN JUL 22 2012
.SYNOPSIS...
A WEAK TROUGH WILL MAKE ITS WAY INTO THE AREA THIS
AFTERNOON...BRINGING A CHANCE FOR SOME SHOWERS AND POSSIBLY A
THUNDERSTORM WITH IT...ESPECIALLY TO THE FINGER LAKES AND SOUTHERN
TIER REGIONS. A STRONGER TROUGH WILL MOVE THROUGH ON MONDAY
AFTERNOON...BRINGING YET ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS. HIGH PRESSURE WILL BUILD BACK INTO THE AREA FOR THE
MIDDLE OF THE WEEK..
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
630AM UPDATE...MODELS CONTINUE TO SHOW THE FRONT/TROUGH FALLING
APART AS IT REACHES THE CWA SOMETIME AFTER MID DAY. THE HRRR IS A
LITTLE FASTER, BUT APPEARS TO BE ALREADY OVERDOING PRECIPITATION
THIS MORNING. EVEN SO, IT SHOWS ONLY SOME SHOWERS ALONG THE
WESTERN CWA BORDER AND THEN BREAKING UP LATER TODAY. DID DECIDE TO
SPREAD POPS A LITTLE FURTHER EAST THIS AFTERNOON, BUT REALLY DID
NOT RAISE THEM ABOVE THE LOW END CHC POPS THAT WERE ALREADY THERE.
THERE IS JUST GREAT UNCERTAINTY WITH THIS FORECAST, AS THERE IS
UNCERTAINTY IN REGARDS TO THE STRENGTH AND EXACT TIMING OF THE
TROUGH.
PREVIOUS DISCUSSION...A COLD FRONT WILL APPROACH THE AREA AND
BEGIN TO DISSIPATE INTO MORE OF A WEAK TROUGH. IT MAY BE ENOUGH TO
TRIGGER SOME ISOLATED TO SCATTERED SHOWERS OR THUNDERSTORMS OVER
THE CWA...WITH THE FINGER LAKES SEEING THE BEST CHANCE AT SEEING
CONVECTIVE DEVELOPMENT. CAPE VALUES OVER THE FINGER LAKES WILL BE
BETWEEN 1500 AND 2000 JOULES. LIS WILL BE AROUND -6. HOWEVER, THE
BEST CAPE WILL NOT OCCUR UNTIL LATE AFTERNOON INTO EARLY EVENING.
SO, IT MAY NOT BE ABLE TO CAPITALIZE ON DAYTIME HEATING. ALSO, MID
AND UPPER LEVEL LAPSE RATES ARE NOT IN FAVOR OF DEVELOPMENT. THE
MAIN LOW WILL BE PULLING WELL TO THE NORTH OF THE CWA, AS IT WILL
BE CENTERED NORTH OF THE HUDSON BAY. MODELS SHOW THE FRONT
CONTINUES TO DETERIORATE AS IT MOVES INTO THE CWA. BUT, STILL CAN
NOT RULE OUT SOME DEVELOPMENT LATER TODAY, SO AGAIN, CHC POPS IN
THE FINGER LAKE AND ISOLD IN THE REST OF THE AREA FOR NOW.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
THE TROUGH, OR WHAT IS LEFT OF IT, SHOULD STALL IN THE VICINITY OF
THE CWA. THIS KEEPS A MENTION OF SHOWERS AND STORMS IN THE
FORECAST SUNDAY NIGHT. POPS INCREASE QUITE A BIT FOR MONDAY AS A
MORE VIGOROUS SHORT WAVE AND A PRE- FRONTAL TROUGH APPROACH THE
REGION. THE MAIN COLD FRONT WILL MOVE THROUGH MONDAY NIGHT, WHICH
WILL KEEP CONVECTION GOING THROUGH THE NIGHT AND INTO TUESDAY MORNING,
ALBEIT LOWER POPS WITH THE LOSS OF DAYTIME HEATING. HIGH PRESSURE
WILL QUICKLY TRY TO BUILD IN BEHIND THIS FRONT, BRINGING A HALT TO
SHOWERS BY LATE TUESDAY AFTERNOON OR EARLY TUESDAY EVENING.
HIGH TEMPERATURES WILL BE PERSISTENT FROM SUNDAY THROUGH TUESDAY,
REACHING INTO THE LOW TO MID 80S, TO POSSIBLY EVEN NEAR 90 TOWARDS
THE LAKE PLAIN. LOWS FOR MONDAY AND TUESDAY WILL ALSO BE
PERSISTENT, ON GETTING INTO THE MID 60S OVER MOST OF THE AREA.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
UPPER PATTERN DURING THIS TIME FRAME WILL BE DOMINATED BY DEEP
CLOSED LOW PRESSURE ACROSS EASTERN CANADA...WITH A BUILDING RIDGE
ACROSS THE AMERICAN/CANADIAN WEST. FAIR AND DRY WX EXPECTED AT THE
START OF THE EXTENDED PERIOD AS HIGH PRESSURE DIVES SOUTH FROM
SOUTHERN CANADA. WITH WEAK NORTHERLY FLOW EXPECTED...TEMPS WILL
HOVER JUST BELOW NORMAL FOR DAYTIME HIGHS UNDER MOSTLY SUNNY
SKIES. HIGH PRESSURE WILL EXIT STAGE RIGHT WEDNESDAY NGT IN
ADVANCE OF A SLOW MOVING DISTURBANCE APPROACHING FROM THE WESTERN
AND CENTRAL GREAT LAKES. FCST MODELS IN RECENT DAYS HAVE BEEN
SUGGESTING A SLOW MOVING EASTWARD PROGRESSING SHORTWAVE/CLOSED LOW
EMANATING FROM BUILDING HEIGHTS OUT WEST...HOWEVER RECENT MODEL
RUNS HAVE STRUGGLED WITH TIMING AND LOCATION OF SEVERAL FEATURES
TO INCLUDE SFC LOW AND ASSOCIATED FRONTAL BOUNDARY POSITIONS. THAT
SAID...MODELS APPEAR TO BE CONVERGING ON A SOLUTION THAT BRINGS
THE FIRST SFC LOW EAST ACROSS OUR AREA ON THU...WITH CONTINUED
UNSETTLED CONDITIONS THEN EXPECTED THROUGH THE DURATION OF THE
FCST PERIOD AS ADDITIONAL SFC WAVES INTERACT WITH A STALLED FRONT
ACROSS THE NORTHERN MID-ATLANTIC AND OHIO VLY REGIONS.
AFOREMENTIONED CLOSED LOW WILL EVENTUALLY BEGIN UNDERCUTTING
EASTERN CANADIAN UPPER LOW BY LATE WEEK...HOWEVER WITH ANY POLAR
STREAM WINDS DISPLACED WELL TO THE NORTH...SHORTWAVE ENERGY/UPPER
LOW APPROACHING FROM THE NORTHWEST WILL INCH ALONG EVER SO SLOWLY. THE
END RESULT WILL BE CONTINUED CHANCES FOR RA/STORMS THROUGH THE
NEXT WEEKEND WITH AT OR BELOW NORMAL TEMPS.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
MID-LEVEL CLOUD DECK CURRENTLY MOVING OVER THE AREA IN ADVANCE OF
A WEAK SFC TROUGH OFF TO OUR WEST. UPSTREAM SFC OBS INDICATE
NEARLY STEADY TEMPS AS FAR WEST AS SOUTHERN ONTARIO AND EASTERN MI
THIS HR AS A RESULT OF INCREASING WARM AIR ADVECTION AHEAD OF
AFOREMENTIONED TROUGH. CONSIDERING CROSSOVER TEMPS WERE IN THE UPPER
50S YESTERDAY AFTERNOON IN ELM...AND WITH BEST MOISTURE POOLING SOUTH
ACROSS CENTRAL AND SOUTHERN PA THIS HR...HAVE BACKED OFF ON IFR
FOG MENTION AT THE ELM TERMINAL FOR NOW. FURTHER SOUTH AT
AVP...LATEST 11-3.9U SATELLITE IMAGERY SHOWING LEADING EDGE OF LOW
STRATUS SLOWLY WORKING NORTH THROUGH THE LWR WYOMING VLY. THAT
SAID...HAVE INSERTED A TEMPO MVFR MENTION AT 09Z TO ACCOUNT FOR
THE POSSIBILITY OF THESE CLOUDS MOVING OVER THE TERMINAL.
REMAINING SITES...EXPECT VFR THROUGH THE EARLY MORNING HRS.
AS WE PROGRESS THROUGH THE DAY TODAY...EXPECT LGT SW TO W WINDS
BETWEEN 5-10 KTS. PLENTY OF MID-LEVEL MOISTURE WILL REMAIN IN
PLACE THUS EXPECT A DEVELOPING STRATOCU ONCE AGAIN. FCST MODELS DO
HINT AT DEVELOPING SHWRS/STORMS BY EARLY AFTERNOON AS THETA-E
RIDGE MOVES INTO THE AREA...HOWEVER WITH VERY LITTLE UPPER-LEVEL
SUPPORT...NOT ENOUGH CONFIDENCE EXISTS FOR INCLUSION AT THIS
TIME.
OUTLOOK...
MON AND TUE...VFR...CHC MVFR IN SHWR/TSTM MAINLY IN THE AFTERNOON.
WED/THU...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...SLI
NEAR TERM...SLI
SHORT TERM...SLI
LONG TERM...TAC
AVIATION...CMG
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1015 PM EDT MON JUL 23 2012
.SYNOPSIS...
A SERIES OF UPPER LEVEL DISTURBANCES WILL CROSS THE MID ATLANTIC
REGION THROUGH TUESDAY NIGHT. THESE DISTURBANCES WILL GLANCE CENTRAL
NORTH CAROLINA...CAUSING SCATTERED THUNDERSTORMS TO OCCUR.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 PM MONDAY...
AN UPPER LEVEL WAVE ALONG WITH MERGING OUTFLOWS HELPED TO PRODUCE A
BROKEN LINE OF CONVECTION THAT WAS RESPONSIBLE FOR SEVERAL SEVERE
STORMS THIS EVENING...WHICH HAS NOW PUSHED EAST OF THE CWA.
ADDITIONAL SHOWERS AND STORMS WERE MOVING OFF OF THE HIGHER TERRAIN
OF VA AROUND SUNSET BUT HAVE SINCE DISSIPATED WITH STABILIZATION AND
SUBSIDENCE IN THE WAKE OF THE UPPER WAVE. WATER VAPOR IMAGERY LOOKS
TO BE VOID OF ANY ADDITIONAL UPPER LEVEL DISTURBANCES FOR THE
OVERNIGHT PERIOD...SO THERE SHOULD NOT BE MORE THAN AN ISOLATED
SHOWER/STORM OR TWO ON A REMNANT OUTFLOW...MAINLY PRIOR TO 06Z.
SOME CLEARING IS EVIDENT OVER VA ON IR IMAGERY...AND RUC RH CROSS
SECTIONS SUGGEST ENOUGH NEAR SURFACE MOISTURE FOR FOG TO DEVELOP.
HOWEVER...A LIGHT SOUTHERLY WIND SHOULD STIR ENOUGH TO KEEP PATCHY
FOG LIMITED TO AREAS WHERE RAIN WAS PARTICULARLY HEAVY...MAINLY
SOUTHEAST OF THE TRIANGLE. STRATUS IS ALSO NOT FORECAST BY THE
MODELS BUT IT WOULD NOT BE SURPRISING TO SEE SOME DEVELOP OVER THE
COASTAL PLAIN IN THE WAKE OF THE RAINFALL. OTHERWISE..THE ONLY
CHANGES TO THE FORECAST WERE TO TRIM LOWS SLIGHTLY ACROSS THE NORTH
WHERE SKIES MAY CLEAR OFF AND DEWPOINTS ARE SLIGHTLY LOWER...70-74
NORTH TO SOUTH.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 321 PM MONDAY...
TUESDAY AND TUESDAY NIGHT...ANOTHER IN A SERIES OF UPPER LEVEL
DISTURBANCES WILL APPROACH FROM THE NW IN THE MORNING AND AFFECT
CENTRAL TUESDAY AFTERNOON AND TUESDAY NIGHT. MID LEVEL SHEAR A TAD
BETTER THAN THIS AFTERNOON WHICH SUGGEST BETTER CHANCE FOR
STRONG/DAMAGING WIND GUSTS WITH THE STRONGEST CONVECTION. APPEARS TO
BE ENOUGH AMPLE TIME IN THE MORNING THROUGH EARLY AFTERNOON FOR
STRONG INSOLATION TO ACHIEVE SBCAPE VALUES 4000-5000 J/KG AND MLCAPE
2500-3500 J/KG. INSTABILITY ALOFT SUGGEST POTENTIAL FOR DAMAGING
WIND GUSTS AND MARGINALLY SEVERE HAIL. IN ADDITION...A FEW OF THE
STORMS COULD PRODUCE A LARGE AMOUNT OF LIGHTNING.
WITH LOW LEVEL THICKNESSES COMPARABLE TO TODAY...EXPECT SIMILAR
TEMPS TUESDAY AFTERNOON IN THE MID 90S...THOUGH COULD BE A TOUCH
"COOLER" IF CLOUDS COME IN SOONER/THICKER IN THE NW PIEDMONT.
CONVECTION WILL SLOWLY DIMINISH TUESDAY EVENING WITH BULK OF
ACTIVITY AFTER MIDNIGHT EXPECTED OVER THE SOUTHERN COUNTIES THOUGH
APPROACH OF ANOTHER DISTURBANCE INT EH NW FLOW MAY SPARK A FEW
SHOWERS IN THE NW PIEDMONT AFTER 2 AM. MIN TEMPS 69-74. -WSS
NORTHWEST MID LEVEL FLOW WILL BE DIRECTED INTO THE AREA ON
WEDNESDAY...WITH PERTURBATIONS IN THE SHEAR AXIS MOVING ACROSS THE
AREA DURING THE DAY. MEANWHILE...WEAK AND COOLER SURFACE HIGH
PRESSURE BUILDS BRIEFLY INTO THE REGION...WITH DRIER NORTHERLY FLOW
EDGING INTO THE NORTHERN TIER. WILL CONTINUE A CHANCE POP GRADUATED
HIGHER SOUTH. LOW LEVEL THICKNESSES SUGGESTS THAT HIGH TEMPS WILL BE
MOSTLY IN THE LOW 90S. DRYING CONTINUES WITH A TRANSITION TO LOW
AMPLITUDE RIDGING WEDNESDAY NIGHT...COULD ARGUE FOR A LINGERING
SLIGHT CHANCE POP ACROSS THE SOUTH AND EAST EARLY WED NIGHT...NOT
ENOUGH CONSISTENCY TO INCLUDE AT THIS POINT. MINS WILL BE
PERSISTENCE...70 TO 75. -MLM
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 100 PM MONDAY...
THE INITIAL EXTENDED FORECAST STARTS OUT THURSDAY WITH A FAMILIAR
PATTERN...SURFACE LEE TROFFING OVER CENTRAL NC AND WESTERLY FLOW
ALOFT. THE RESULTING HIGH INSTABILITY (HIGHS 92-96) BUT LACK OF
FORCING MECHANISMS ARE CONDUCIVE TO WIDELY SCATTERED DIURNAL
CONVECTION...WITH SLIGHT NODS FOR HIGHER POPS IN THE WEST WHERE
DIFFERENTIAL HEATING AND EASTWARD DRIFT OF SUBSEQUENT CONVECTION...
AND SEA BREEZE PENETRATION INTO THE COASTAL PLAIN.
A FRONT SAGGING SOUTH LATER FRIDAY OR FRIDAY NIGHT WILL PROVIDE SOME
ENHANCED LOW LEVEL CONVERGENCE W/ENHANCED CONVECTIVE CHANCES AS IT
WILL BE ACCOMPANIED BY SHARPENING OF AN UPPER TROF OVER THE EASTERN
CONUS. WILL CONTINUE CHANCE POPS FRIDAY AND SLIGHT CHANCES FRIDAY
NIGHT WITH FROPA CURRENTLY PROGGED FRIDAY NIGHT...WHICH WOULD BE
LEAST FAVORABLE STABILITY-WISE. HIGHS FRIDAY WILL REACH THE LOW TO
MID 90S.
UPPER TROF WILL BE IN PLACE SATURDAY AND MIGRATING SLOWLY EAST
THROUGH MONDAY...WITH ATTENDANT NORTHWEST FLOW. TEMPS WILL BE
SEASONABLE...LOW 90S AFTER MORNING LOWS 70 TO 75. CONVECTION WILL BE
MAINLY DRIVEN BY SMALLER SCALE PERTURBATIONS IN THE MID LEVEL
FLOW...WHICH OF COURSE ARE NOT FORECASTABLE THIS EARLY IN THE GAME.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 920 PM MONDAY...
SHOWERS AND STORMS HAVE GENERALLY DISSIPATED/MOVED TO THE EAST OF
THE AREA THIS EVENING. HOWEVER.... A SHOWER OR STORM MAY STILL
AFFECT KFAY OVER THE NEXT SEVERAL HOURS... GENERALLY THROUGH 03-04Z.
THUS... OUTSIDE OF ANY LINGERING SHOWERS AND STORMS EXPECTED VFR
CONDITIONS FOR THE REMAINDER OF THE EVENING... WITH THE POSSIBILITY
OF SOME MVFR VISBYS AFTER MIDNIGHT UNTIL DAYBREAK (MAYBE IFR AT
KRWI) AT LOCATIONS WHICH RECEIVED SOME RAINFALL... MAINLY KRDU AND
KRWI. THUS... WILL GO WITH A TEMPO GROUP OF MVFR VISBYS AT KRDU IN
THE 08-12Z TIMEFRAME... WITH PREDOMINATE MVFR VISBYS AFTER MIDNIGHT
AND TEMPO IFR VISBYS AT KRWI UNTIL AROUND DAYBREAK. ELSEWHERE...
GIVEN SURFACE WINDS ARE TO REMAIN IN THE 4 TO 10 KT RANGE
OVERNIGHT... EXPECT VISBYS SHOULD REMAIN VFR. HOWEVER... A LOW LEVEL
JET (30-35KTS) CENTERED BETWEEN 2000-3000FT OVERNIGHT MAY CREATE A
WIND PROFILE JUST SHY OF LOW LEVEL WIND SHEAR CRITERIA.
TUESDAY...ANOTHER UPPER LEVEL DISTURBANCE WILL CAUSE ANOTHER THREAT
OF SCATTERED STRONG CONVECTION LATE IN THE DAY AND WELL INTO THE
EVENING HOURS. FOR WEDNESDAY THROUGH SATURDAY...EXPECT A DAILY
THREAT FOR ISOLATED TO SCATTERED CONVECTION IN THE AFTERNOON-EARLY
EVENING HOURS WITH ASSOCIATED MVFR CEILINGS/VISIBILITY. IN
ADDITION...THERE WILL BE POCKETS OF MVFR/IFR FOG AND STRATUS BETWEEN
5 AM AND 9 AM EACH MORNING.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...WSS/SMITH
SHORT TERM...WSS/MLM
LONG TERM...MLM
AVIATION...BSD/WSS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
210 AM EDT SUN JUL 22 2012
.SYNOPSIS...
UPPER LEVEL DISTURBANCES TRACKING SOUTHEAST INTO A MOIST AND
UNSTABLE AIRMASS OVER THE REGION WILL RESULT IN SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS AGAIN THIS AFTERNOON AND EVENING.
WARMER TEMPERATURES AND DAILY CHANCES FOR AFTERNOON SHOWERS AND
THUNDERSTORMS ARE EXPECTED THROUGH MUCH OF THE UPCOMING WORK WEEK IN
ASSOCIATION WITH A PERSISTENT PATTERN OF NORTHWEST FLOW ALOFT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 955 PM SATURDAY...
DPVA ASSOCIATED WITH AN ELONGATING SHEAR AXIS APPROACHING FROM THE
NORTHWEST AND A COUPLE SUBTLE DISTURBANCES NOTED IN WATER VAPOR
IMAGERY AND RUC 500MB ANALYSIS... ARE HELPING TO SUSTAIN CONVECTION
ALONG VARIOUS OUTFLOWS AND PRESUMABLY THE ORIGINAL WEAK COLD FRONT
NEAR THE VA BORDER EARLIER THIS AFTERNOON. THE APPROACH OF THE
UPPER LEVEL SHEAR AXIS AND MERGING COLD POOLS APPEARS TO BE HELPING
TO PUSH THE FRONT SOUTHWARD TOWARD THE US HWY 64 CORRIDOR...WHERE
ONGOING THUNDERSTORMS CURRENTLY STRETCH FROM NEAR ASHEBORO TO
RALEIGH TO THE ROCKY MOUNT AREA. WHILE MUCH OF THE CWA HAS BEEN
STABILIZED BY CONVECTION DURING THE PAST 6 HOURS...PW IS STILL
AROUND 2 INCHES AND THE SPC MESOANALYSIS SHOWS AN AXIS OF MLCAPE
EXTENDING FROM THE SOUTHERN PIEDMONT TO THE SANDHILLS....WHICH
SHOULD SUPPORT SCATTERED SHOWERS AND STORMS INTO THE OVERNIGHT
HOURS. MOST OF THE OPERATIONAL MODELS KEEP CONVECTION GOING THROUGH
12Z WHILE THE SHEAR AXIS MOVES ACROSS THE AREA...WITH MOST QPF
SHIFTING TOWARD THE COAST. THE SEVERE THREAT...WHICH HAS BEEN
LIMITED TO JUST A FEW STORMS THIS EVENING...WILL ALSO BE ON DOWNWARD
TREND AS INSTABILITY WANES. RAINFALL WAS RATHER HEAVY THIS EVENING
WITH A FEW AREAS RECEIVING 2-4 INCHES...ESPECIALLY OVER THE NORTHERN
COASTAL PLAIN...SO THERE MAY BE SOME PATCHY FOG LATE TONIGHT. THE
HRRR AND RUC RH CROSS-SECTIONS SUGGEST STRATUS WILL REDEVELOP BY
09Z...AND THERE ARE SIGNS OF STRATUS ALREADY DEVELOPING NORTH OF THE
NC/VA BORDER. LOWS SHOULD HOLD IN THE LOW TO MID 70S.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 210 AM SUNDAY...
THE MODELS ARE IN AGREEMENT IN THAT STRONG UPPER RIDGING CENTERED
OVER KS/MO WILL EXTEND EASTWARD OVER THE TENNESSEE AND OHIO VALLEYS
TO THE SOUTHEAST ATLANTIC COAST MONDAY THROUGH TUESDAY NIGHT. THE
CORE OF THE RIDGING IS FORECAST TO REMAIN OVER THE CENTRAL PLAINS
BUT EXTEND ESE ACROSS THE GULF COAST STATES MONDAY INTO MONDAY
NIGHT. MODELS THEN FORECAST ANOTHER SHORT WAVE TROUGH TO DEVELOP AND
DIVE SE FROM THE GREAT LAKES TO THE MID-ATLANTIC LATE TUESDAY AND
WEDNESDAY. THE BOTTOM LINE FOR NORTH CAROLINA... HOT AND HUMID WITH
TYPICAL SUMMERTIME WEATHER WITH THE CORE OF THE EXTREME HEAT AND
DROUGHT EXPECTED TO REMAIN WELL WEST OF OUR REGION OVER KS/MO TO
IA/IL. MONDAY AND TUESDAY SHOULD BRING THE LEAST CHANCES OF
AFTERNOON AND EVENING THUNDERSTORMS. WE WILL CARRY ONLY 20-30 POP
WITH THE HIGHEST POP EXPECTED ALONG AND EAST OF THE PIEDMONT TROUGH
(WHICH MAY BE PUSHED TO THE FAR EASTERN PIEDMONT OR WESTERN COASTAL
PLAIN AND SANDHILLS BOTH DAYS. THEREFORE... 20 POP NW AND 30 POP SE
LOOKS REASONABLE. EXPECT MOSTLY SUNNY TO PARTLY SUNNY SKIES BOTH
DAYS WITH HIGHS IN THE LOWER TO MID 90S. LOWS WILL BE IN THE LOWER
TO MID 70S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 210 AM SUNDAY...
THE OVERALL FLOW PATTERN ACROSS THE UNITED STATES IS FORECAST TO
CONTINUE TO REPEAT ITSELF WITH THE MEAN UPPER RIDGE EXPECTED TO BE
LOCKED OVER THE PLAINS AND ROCKIES... AND THE NORTHEAST UNITES
STATES TROUGH WILL REESTABLISH ITSELF LATE WEEK. PERIODIC
DISTURBANCES IN THE NW FLOW ALOFT WILL POSSIBLY BRING ENHANCED
CHANCES OF THUNDERSTORMS... FOLLOWED BY A STRONGER UPPER SHORT WAVE
TROUGH AGAIN LATE WEEK. ONE WAVY FRONT SHOULD MAKE A RUN AT THE
REGION AROUND WEDNESDAY... FOLLOWED BY ANOTHER STRONGER FRONT BY
LATE WEEK OR THE WEEKEND. THESE FEATURES ARE DIFFICULT TO TIME THIS
FAR OUT. FOR NOW... WE WILL MAINTAIN A CHANCE OF MAINLY AFTERNOON
AND EVENING THUNDERSTORMS WEDNESDAY THROUGH SATURDAY... WITH THE
BEST CHANCES WITH THE APPROACH OF THE AFOREMENTIONED HARD TO TIME
FEATURES AND ASSOCIATED COLD FRONTS. IT APPEARS THAT ANY FRONT WILL
CONTINUE TO HAVE A VERY DIFFICULT TIME PROVIDING ANY COOLER DRIER
AIR. HOWEVER... AND MORE IMPORTANTLY... THE FRONTS WILL CONTINUE TO
SUPPLY THE REGION WITH MUCH NEEDED DRENCHING AND COOLING
THUNDERSTORMS ON A SCATTERED BASIS. HIGHS WILL REMAIN 90-95. LOWS
70-75 WED-SAT.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 150 AM SUNDAY...
24-HR TAF PERIOD:
ISOLATED SHOWER ACTIVITY WILL REMAIN POSSIBLE AT ALL TAF SITES
THROUGH THE REMAINDER OF THE MORNING. GIVEN LITTLE CHANGE IN THE
ATMOSPHERE OVER CENTRAL NC COMPARED TO THE PAST SEVERAL DAYS...
EXPECT AREAS OF IFR/LIFR CEILINGS TO DEVELOP PRIOR TO SUNRISE AND
PERSIST THROUGH MID/LATE MORNING...LIFTING TO MVFR AND EVENTUALLY
SCATTERING OUT BETWEEN 15-18Z...WITH AFTERNOON CEILINGS GENERALLY
RANGING BETWEEN 3000-4000 FT AGL. ONCE AGAIN...EXPECT SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS TO DEVELOP FROM MID/LATE
AFTERNOON THROUGH THIS EVENING AS UPPER LEVEL DISTURBANCES TRACK
THROUGH A MOIST/UNSTABLE AIRMASS OVER THE REGION. ANTICIPATE THE
MOST LIKELY TIME-FRAME FOR CONVECTION WILL BE BETWEEN 19Z THIS
AFTERNOON AND 03Z TONIGHT. THE LATEST MODEL GUIDANCE INDICATES
STRENGTHENING WEST/SW FLOW BETWEEN 1500-5000 FT AGL ADVECTING A
DRIER LOW-LEVEL AIRMASS INTO CENTRAL NC BY THE END OF THE TAF PERIOD
(06-12Z MONDAY)...AND IT APPEARS THAT IFR/LIFR CEILINGS ARE LESS
LIKELY TO DEVELOP DURING THE PRE-DAWN HOURS MONDAY MORNING.
HOWEVER...FORECAST SOUNDINGS INDICATE A 25-30 KT SOUTHWESTERLY
LOW-LEVEL JET DEVELOPING AT ~1500 FT AGL PRIOR TO SUNRISE MONDAY
MORNING IN THE PRESENCE OF LIGHT/VARIABLE SURFACE WINDS. AS A
RESULT...A SHORT PERIOD OF SOUTHWESTERLY LOW LEVEL WIND SHEAR WILL
BE POSSIBLE BETWEEN 06-12Z MONDAY MORNING.
LOOKING AHEAD:
NORTHWEST FLOW ALOFT WILL BE IN PLACE OVER THE REGION THROUGHOUT
MUCH (IF NOT ALL) OF THE UPCOMING WORK WEEK. AS A RESULT...EXPECT
DAILY CHANCES FOR SCATTERED SHOWERS AND THUNDERSTORMS (MOST LIKELY
AFTERNOON/EVENING) AND A POTENTIAL FOR FOG OR LOW CEILINGS DURING
THE PRE-DAWN HOURS EACH MORNING. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...DJF/SMITH
SHORT TERM...BADGETT
LONG TERM...BADGETT
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
203 AM EDT SUN JUL 22 2012
.SYNOPSIS...
UPPER LEVEL DISTURBANCES TRACKING SOUTHEAST INTO A MOIST AND
UNSTABLE AIRMASS OVER THE REGION WILL RESULT IN SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS AGAIN THIS AFTERNOON AND EVENING.
WARMER TEMPERATURES AND DAILY CHANCES FOR AFTERNOON SHOWERS AND
THUNDERSTORMS ARE EXPECTED THROUGH MUCH OF THE UPCOMING WORK WEEK IN
ASSOCIATION WITH A PERSISTENT PATTERN OF NORTHWEST FLOW ALOFT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 955 PM SATURDAY...
DPVA ASSOCIATED WITH AN ELONGATING SHEAR AXIS APPROACHING FROM THE
NORTHWEST AND A COUPLE SUBTLE DISTURBANCES NOTED IN WATER VAPOR
IMAGERY AND RUC 500MB ANALYSIS... ARE HELPING TO SUSTAIN CONVECTION
ALONG VARIOUS OUTFLOWS AND PRESUMABLY THE ORIGINAL WEAK COLD FRONT
NEAR THE VA BORDER EARLIER THIS AFTERNOON. THE APPROACH OF THE
UPPER LEVEL SHEAR AXIS AND MERGING COLD POOLS APPEARS TO BE HELPING
TO PUSH THE FRONT SOUTHWARD TOWARD THE US HWY 64 CORRIDOR...WHERE
ONGOING THUNDERSTORMS CURRENTLY STRETCH FROM NEAR ASHEBORO TO
RALEIGH TO THE ROCKY MOUNT AREA. WHILE MUCH OF THE CWA HAS BEEN
STABILIZED BY CONVECTION DURING THE PAST 6 HOURS...PW IS STILL
AROUND 2 INCHES AND THE SPC MESOANALYSIS SHOWS AN AXIS OF MLCAPE
EXTENDING FROM THE SOUTHERN PIEDMONT TO THE SANDHILLS....WHICH
SHOULD SUPPORT SCATTERED SHOWERS AND STORMS INTO THE OVERNIGHT
HOURS. MOST OF THE OPERATIONAL MODELS KEEP CONVECTION GOING THROUGH
12Z WHILE THE SHEAR AXIS MOVES ACROSS THE AREA...WITH MOST QPF
SHIFTING TOWARD THE COAST. THE SEVERE THREAT...WHICH HAS BEEN
LIMITED TO JUST A FEW STORMS THIS EVENING...WILL ALSO BE ON DOWNWARD
TREND AS INSTABILITY WANES. RAINFALL WAS RATHER HEAVY THIS EVENING
WITH A FEW AREAS RECEIVING 2-4 INCHES...ESPECIALLY OVER THE NORTHERN
COASTAL PLAIN...SO THERE MAY BE SOME PATCHY FOG LATE TONIGHT. THE
HRRR AND RUC RH CROSS-SECTIONS SUGGEST STRATUS WILL REDEVELOP BY
09Z...AND THERE ARE SIGNS OF STRATUS ALREADY DEVELOPING NORTH OF THE
NC/VA BORDER. LOWS SHOULD HOLD IN THE LOW TO MID 70S.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
AS OF 250 PM SATURDAY...
WHILE MOISTURE REMAINS PLENTIFUL OVERALL...WITH PRECIPITABLE WATER
VALUES TO AROUND TWO INCHES PARTICULARLY ON THE NAM...THE GFS BUFR
SOUNDINGS ARE NOTICEABLY MORE STABLE PARTICULARLY WITH SLIGHT
WARMING IN THE LAYER AROUND 850MB. THE SHEAR AXIS WEAKENS AND SHOULD
PIVOT WEST AND WEAKEN IN RESPONSE TO INCREASING HEIGHTS ALOFT. WHILE
OVERALL INSTABILITY APPEARS BETTER SUNDAY AFTERNOON AS OPPOSED TO
THIS AFTERNOON...WITH MLCAPE LIKELY REACHING OR JUST EXCEEDING
2000J/KG...OVERALL COVERAGE OF SHOWERS AND THUNDERSTORMS IN CENTRAL
NORTH CAROLINA IS LIKELY TO BE LESS AS A RESULT OF WHAT SHOULD BE
DIMINISHING SYNOPTIC SUPPORT. THE FRONT SHOULD CONTINUE TO SLOWLY
WEAKEN...AND WITH THE SHEAR AXIS WEAKENING AS WELL...WILL CONTINUE
THE FORECAST OF SCATTERED SHOWERS AND THUNDERSTORMS FROM THE
AFTERNOON THROUGH THE EARLY EVENING. THERE IS STILL THE POTENTIAL
FOR AN ISOLATED DAMAGING WIND THREAT...AND AGREE WITH THE SPC DAY 2
ASSESSMENT OF THAT ISOLATED POTENTIAL. DOWNDRAFT CAPE IS 500-900J/KG
AS FORECAST BY THE MORE ROBUST NAM...UNDER A RELATIVE MAXIMUM OF
850MB THETA-E. HIGH TEMPERATURES SHOULD MOSTLY BE IN THE LOWER 90S...
WITH A FEW HIGHS POSSIBLE AROUND 90 OR TOWARD 95 DEPENDING ON HOW
QUICKLY ANY MORNING LOW CLOUDS DIMINISH...AND THE ONSET OF ANY DEEP
CONVECTION.
SUNDAY NIGHT...BOTH THE NAM AND THE GFS BUFR SOUNDINGS BECOME FAIRLY
STABLE TO DEEP CONVECTION. THE GFS DOES FORECAST SOME OVERNIGHT
QPF...BUT ITS MOS GUIDANCE CHANCES OF RAIN ARE LOW LATE AT NIGHT...
AND WITH CONVERGENCE ALOFT FORECAST OVERNIGHT SUNDAY...IT WOULD SEEM
CHANCES FOR ANY SHOWERS AND THUNDERSTORMS SHOULD FALL BELOW SLIGHT
CHANCE BY AROUND MIDNIGHT. OVERNIGHT LOWS ONCE AGAIN SHOULD BE
MOSTLY IN THE RANGE OF 70 TO 75.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 250 PM SATURDAY...
THE MAIN WEATHER FEATURE DURING MUCH OF THE LONG TERM PERIOD WILL BE
BROAD MID LEVEL RIDGING THAT IS PROGGED TO EXTEND FROM THE CENTRAL
PLAINS INTO THE SOUTHEAST...WITH CENTRAL NC ON THE NORTHERN
PERIPHERY OF THIS RIDGE. THEREFORE...WE WILL BE UNDER NORTHWESTERLY
FLOW ALOFT FOR MUCH OF THE PERIOD AND HENCE THE POTENTIAL FOR WEAK
DISTURBANCES TO IMPACT THE AREA WILL LIKELY BE OUR MAIN CHANCES FOR
ANY PRECIP BEYOND TYPICAL SUMMERTIME CONVECTION. MODELS ALSO
INDICATE (TO VARYING DEGREES) A BACK DOOR FRONT APPROACHING THE AREA
MIDWEEK...BUT GIVEN THE TIME OF YEAR...WILL KEEP THE FRONT NORTH OF
REGION FOR NOW. AS A RESULT...SINCE IT IS IMPOSSIBLE TO TIME ANY
WEAK UPPER LEVEL DISTURBANCES THIS FAR OUT...AM EXPECTING MOSTLY
ISOLATED TO SCATTERED DIURNAL TYPE PRECIP AS A WEAK SURFACE TROUGH
WILL BE IN PLACE OVER THE REGION. THEN...AT THE END OF THE WORK
WEEK...A SHORT WAVE TROUGH IS PROGGED TO AMPLIFY ACROSS THE NORTHERN
PLAINS WHICH WILL EVENTUALLY SUPPRESS THE RIDGE. AS THIS SHORT WAVE
MOVES EAST AND AMPLIFIES EVEN MORE...IT SHOULD BEGIN TO CARVE AN
UPPER LEVEL TROUGH OVER THE REGION BY THE WEEKEND...WITH AN
ASSOCIATED SURFACE FRONT APPROACHING FROM THE NORTHWEST. WILL STILL
KEEP ONLY SCATTERED DIURNAL CONVECTION IN THE FORECAST FOR THIS TIME
FRAME...BUT WILL SHOW A SLIGHT INCREASE IN THE POPS. THE HEAT WILL
ALSO RETURN TO THE REGION...WITH GENERALLY MID (AND SOME UPPER) 90S
EXPECTED FOR MOST OF THE PERIOD. OVERNIGHT LOWS WILL REMAIN IN THE
LOW TO MID 70S.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 150 AM SUNDAY...
24-HR TAF PERIOD:
ISOLATED SHOWER ACTIVITY WILL REMAIN POSSIBLE AT ALL TAF SITES
THROUGH THE REMAINDER OF THE MORNING. GIVEN LITTLE CHANGE IN THE
ATMOSPHERE OVER CENTRAL NC COMPARED TO THE PAST SEVERAL DAYS...
EXPECT AREAS OF IFR/LIFR CEILINGS TO DEVELOP PRIOR TO SUNRISE AND
PERSIST THROUGH MID/LATE MORNING...LIFTING TO MVFR AND EVENTUALLY
SCATTERING OUT BETWEEN 15-18Z...WITH AFTERNOON CEILINGS GENERALLY
RANGING BETWEEN 3000-4000 FT AGL. ONCE AGAIN...EXPECT SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS TO DEVELOP FROM MID/LATE
AFTERNOON THROUGH THIS EVENING AS UPPER LEVEL DISTURBANCES TRACK
THROUGH A MOIST/UNSTABLE AIRMASS OVER THE REGION. ANTICIPATE THE
MOST LIKELY TIME-FRAME FOR CONVECTION WILL BE BETWEEN 19Z THIS
AFTERNOON AND 03Z TONIGHT. THE LATEST MODEL GUIDANCE INDICATES
STRENGTHENING WEST/SW FLOW BETWEEN 1500-5000 FT AGL ADVECTING A
DRIER LOW-LEVEL AIRMASS INTO CENTRAL NC BY THE END OF THE TAF PERIOD
(06-12Z MONDAY)...AND IT APPEARS THAT IFR/LIFR CEILINGS ARE LESS
LIKELY TO DEVELOP DURING THE PRE-DAWN HOURS MONDAY MORNING.
HOWEVER...FORECAST SOUNDINGS INDICATE A 25-30 KT SOUTHWESTERLY
LOW-LEVEL JET DEVELOPING AT ~1500 FT AGL PRIOR TO SUNRISE MONDAY
MORNING IN THE PRESENCE OF LIGHT/VARIABLE SURFACE WINDS. AS A
RESULT...A SHORT PERIOD OF SOUTHWESTERLY LOW LEVEL WIND SHEAR WILL
BE POSSIBLE BETWEEN 06-12Z MONDAY MORNING.
LOOKING AHEAD:
NORTHWEST FLOW ALOFT WILL BE IN PLACE OVER THE REGION THROUGHOUT
MUCH (IF NOT ALL) OF THE UPCOMING WORK WEEK. AS A RESULT...EXPECT
DAILY CHANCES FOR SCATTERED SHOWERS AND THUNDERSTORMS (MOST LIKELY
AFTERNOON/EVENING) AND A POTENTIAL FOR FOG OR LOW CEILINGS DURING
THE PRE-DAWN HOURS EACH MORNING. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...DJF/SMITH
SHORT TERM...DJF
LONG TERM...KRR
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1254 AM EDT SUN JUL 22 2012
.SYNOPSIS...
TYPICAL SUMMERTIME WEATHER WILL CONTINUE WITH BERMUDA HIGH PRESSURE
OFFSHORE AND SURFACE LOW PRESSURE INLAND PRODUCING SOUTHWEST WINDS
AND LOCALIZED THUNDERSTORMS TO THE EASTERN CAROLINAS. A BUILDING
RIDGE ALOFT WILL BRING A WARMING TREND THROUGH THIS NEW WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 100 AM SUNDAY...PLENTY OF THICK MID-LEVEL CLOUD COVER
(ALTOCUMULUS) COVERS THE EASTERN CAROLINAS EARLY THIS MORNING. THIS
MOISTURE IS ASSOCIATED WITH A MID-LEVEL SHEAR AXIS THAT LIES JUST
EAST OF INTERSTATE 95. RADAR LOOPS SHOW SPRINKLES AND A FEW VERY
LIGHT SHOWERS MOVING WEST TO EAST. THE PAST FEW HRRR MODEL RUNS
ACTUALLY DEVELOP MORE IMPRESSIVE SHOWERS AND THUNDERSTORMS JUST
AHEAD OF THE SHEAR AXIS IN THE NEXT HOUR OR TWO. WHILE I CAN SAY I`M
NOT TOO IMPRESSED WITH THE HRRR`S DUBIOUS TRACK RECORD WITH
CONVECTIVE INITIATION OVER THE PAST WEEK...I`LL ADD SMALL POPS
(20-30 PERCENT) FROM NOW THROUGH 10Z (6 AM) MAINLY FOR THE COASTAL
COUNTIES. WITH CLOUDS AND A STEADY SW SURFACE WIND WE`RE PROBABLY
WITHIN A COUPLE DEGREES OF OUR ULTIMATE OVERNIGHT LOWS...MID 70S
INLAND AND 77-81 NEAR THE COAST. PREVIOUS DISCUSSION FROM 1030 PM
SATURDAY FOLLOWS...
LATEST SFC ANALYSIS PLACES THE STATIONARY FRONT JUST NORTH OF THE
AREA...EXTENDING FROM ROUGHLY DUCK NC WEST-SOUTHWEST TO NASHVILLE
NC. THIS KEEPS THE FA WITHIN THE JUICY AIR MASS PAINTED WITH PWS OF
2+ INCHES. THE MAJORITY OF THE DAYS CONVECTION HAS WANED ACROSS THE
AREA AND WAS LIKELY A PRODUCT FROM SFC FORCING...IE. SEA BREEZE AND
RESIDUAL OUTFLOW BOUNDARIES. MID-LEVEL TROFFINESS WILL PERSIST
TONIGHT INTO SUNDAY. A WEAK IMPULSE EMBEDDED IN 5H FLOW IS PROGGED
TO MOVE FROM GSP THIS EVENING ACROSS PORTIONS OF THE FA OVERNIGHT TO
THE SOUTHERN OUTER BANKS AFTER SUNDAYS SUNRISE. THE DYNAMICS FROM
THE IMPULSE WILL BE ENOUGH TO IGNITE ISOLATED/WIDELY SCATTERED TSRA
DURING A PORTION OF THE OVERNIGHT. AND FOR THAT REASON HAVE KEPT AN
ACTIVE OVERNIGHT POP ACROSS THE NORTHERN PORTIONS OF THE FA THROUGH
THE MID TO LATE EVENING HRS. ANOTHER WARM AND STICKY NIGHT ON TAP
FOR THE FA...WITH LOW TEMPS RANGING FROM THE MID 70S INLAND TO THE
UPPER 70S TO AROUND 80 ALONG THE IMMEDIATE COAST. THE SFC PG IS NOT
AS PRONOUNCED LIKE PREVIOUS NIGHTS. THIS WILL RESULT IN SW WINDS 5
MPH OR LESS INLAND...5 TO 15 MPH ALONG THE IMMEDIATE COAST. THE
UPPER RANGE LIMIT WILL OCCUR THIS EVENING DUE TO THE DECAY OF AN
ACTIVE SEA BREEZE CIRCULATION.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 PM SATURDAY...BERMUDA HIGH AND PIEDMONT TROUGH REMAIN TWO
DOMINANT SURFACE FEATURES CONTROLLING COASTAL CAROLINAS WEATHER.
THIS WILL MAINTAIN A SW SFC FLOW VEERING AROUND TO MORE WESTERLY
THROUGH THE LOW TO MID LEVELS. 850 TO 700 MB WINDS WILL BE 15 TO
25 KTS SUN AFTN INCREASING UP TO 20 TO 30 KTS MON AFTN AS THEY
VEER TOWARD THE NW. MID TO UPPER TROUGH LIFTS OFF TO THE NORTH
NORTHEAST AS RIDGE BUILDS IN FROM EAST AND WEST EXPANDING ACROSS
THE SOUTHEAST SUNDAY THROUGH MONDAY. ANY SHORTWAVE ENERGY TOPPING
THE RIDGE SHOULD REMAIN JUST TO NORTH OF LOCAL CWA. H5 HEIGHTS WILL
RISE UP TO 595 DEM AND WILL SEE INCREASED BUT WEAKER SUBSIDENCE
AND DRIER AIR THROUGH THE MID LEVELS. WITH BEST UPPER LEVEL SUPPORT
TO THE NORTH AND STRONG WESTERLY LOW TO MID LEVEL FLOW...EXPECT
MORE LOCALIZED CONVECTION ALONG CONVERGENT BOUNDARIES TYPICAL OF
SUMMERTIME...WITH BETTER CHC OVER NC. SEA BREEZE SHOULD REMAIN FAIRLY
CLOSE TO THE COAST WITH STRONGER WESTERLY COMPONENT TO
FLOW...ESPECIALLY ON MONDAY. THEREFORE ANY CONVECTION THAT FORMS
ALONG SEA BREEZE BOUNDARY WILL BE CLOSER TO THE COAST AND WILL
MOVE RAPIDLY OFF TO THE EAST TOWARD THE WATERS. ALSO EXPECT OTHER
SHWRS/TSTMS TO DEVELOP ALONG PIEDMONT TROUGH FURTHER INLAND AND
MOVE EAST TOWARD THE COAST. MOISTURE PROFILES DO SHOW VERY MOIST
UPPER LEVELS WITH WINDS ABOVE H4 HAVING GOOD NW-N COMPONENT.
THEREFORE EXPECT PERIODS OF CIRRUS...MAINLY FROM CONVECTIVE DEBRIS
CLOUDS FROM CONVECTION UPSTREAM. THIS SHOULD FILTER OUT SOME OF
THE SUN.
WITH RISING H5 HEIGHTS AND STRONG LOW LEVEL WESTERLY COMPONENT TO
THE FLOW...EXPECT WARM SUMMERTIME TEMPS RUNNING BETWEEN 90 AND 95
MOST PLACES.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 300 PM SATURDAY...A RETURN TO HOT AND HUMID WEATHER EXPECTED
FOR MUCH OF THE EXTENDED...WITH ABOVE CLIMO PRECIP CHANCES THROUGH
LATE WEEK.
LARGE ELONGATED UPPER RIDGE EXTENDING FROM NEBRASKA SOUTHEAST INTO
FLORIDA WILL GET GRADUALLY PUSHED SOUTHWARD AS A LARGE UPPER LOW
ACROSS CANADA SHEARS OFF AND DROPS VORT IMPULSES INTO A BROAD
EASTERN LONGWAVE TROUGH. AS THIS OCCURS...W/NW FLOW DEVELOPS THROUGH
MUCH OF THE COLUMN ABOVE THE IMMEDIATE SURFACE. AT THE
SURFACE...LARGE BERMUDA HIGH PRESSURE GETS SHUNTED SOUTH AS
WELL...BUT NEAR SURFACE S/SW FLOW PERSISTS THROUGH THE PERIOD.
THE COMBINATION OF THE MID LEVEL TROUGH...850MB TEMPS AROUND
20C...AND MOIST RETURN SURFACE FLOW WILL CREATE DECENT CONVECTION
CHANCES EACH DAY...WITH WIDESPREAD COVERAGE POSSIBLE ESPECIALLY ON
WEDNESDAY. AN ACTIVE PIEDMONT TROUGH AND SEA BREEZE FRONT WILL OCCUR
EACH DAY...ALTHOUGH WITH THE DEEP W/NW FLOW THE SEA BREEZE WILL
REMAIN PINNED NEAR THE COAST. PWATS OF TWO INCHES OR GREATER AND
HIGH THETA-E AIR COMBINED WITH STEEP LOW LEVEL LAPSE RATES AND
SUBTLE VORT IMPULSES WILL SPAWN CONVECTION EACH AFTN...BUT MOST
ACTIVITY WILL BE DIURNALLY FORCED AND WILL KEEP INHERITED
CHC-BY-DAY...SILENT-BY-NIGHT POP. THE BEST TSTM COVERAGE WILL BE
WEDNESDAY AHEAD OF A COLD FRONT WHICH WILL TRY TO DROP SOUTH INTO
THE ILM CWA. EXPECT THIS BOUNDARY TO GET HUNG UP JUST NORTH OF THE
AREA...BUT THIS WILL STILL SERVE AS AN ADDITIONAL FOCUS FOR
CONVECTION DURING WED/WED NIGHT. OVERALL POP WILL TREND DOWNWARD
LATE IN THE PERIOD AS 500MB RIDGE BUILDS BACK TO THE NORTH.
HOWEVER...WILL KEEP SCHC POP (SILENT BY DAY 6/7) FOR ISOLATED TSTMS
IN A STILL VERY WARM/MOIST AIR MASS.
850MB TEMPS AROUND 20C WILL SUPPORT HIGHS WELL INTO THE 90S MOST
DAYS EVEN WITH THE LIMITING IMPACT OF CLOUD COVER. MINS AT NIGHT
WILL FALL ONLY INTO THE MID 70S...NEAR 80 SOME NIGHTS AT THE COAST.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 06Z...HRRR MODEL STILL WANTS TO DEVELOP ANOTHER ROUND OF
CONVECTION BETWEEN NOW AND 10Z. MUCH OF THE CWA ATMOSPHERE HAS NOT
BEEN WORKED OVER...SO THIS REMAINS A POSSIBILITY HOWEVER CONFIDENCE
IS RATHER LOW GIVEN THE HRRR`S DUBIOUS TRACK RECORD WITH CONVECTIVE
INITIATION OVER THE PAST WEEK. WE DO EXPECT BKN MID-LEVEL CLOUD
COVER TO REMAIN IN PLACE...WITH LIGHT SOUTHWEST SURFACE WINDS
THROUGH DAYBREAK.
AREAS THAT RECEIVED DECENT RAINFALL...MAINLY LBT...COULD SEE SOME
MVFR FOG TOWARD SUNRISE. AFTER DAYBREAK CONTINUED SOUTHWEST FLOW IS
EXPECTED...A BIT WEAKER THAN SATURDAY. LIKEWISE DEEP MOISTURE IS A
BIT LESS THAN WAS OBSERVED ON SATURDAY...BUT STILL COULD SQUEEZE OUT
ISOLATED CONVECTION IN THE AFTERNOON...MAINLY ALONG THE SEABREEZE
BOUNDARY AND PERHAPS NEAR THE PIEDMONT TROUGH AXIS INLAND.
EXTENDED OUTLOOK...CHANCE OF AFTERNOON THUNDERSTORMS EACH DAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 100 AM SUNDAY...A MODEST SOUTHWEST WIND WILL CONTINUE THROUGH
THE NIGHT AVERAGING 15 KT. A FEW GUSTS COULD APPROACH 20 KT AT
TIMES...ESPECIALLY NEAR THE TIP OF CAPE FEAR...AND OFFSHORE NORTH OF
CAPE FEAR. SEAS RANGE FROM 4 FT AT THE FRYING PAN SHOALS BUOY TO 3
FT AT THE NEARSHORE WRIGHTSVILLE BEACH CORMP BUOY...BOTH RIGHT ON
TARGET WITH OUR PREVIOUS FORECASTS. THE LATEST HRRR MODEL INDICATES
WE MAY SEE RENEWED DEVELOPMENT OF SHOWERS AND THUNDERSTORMS
OVERNIGHT...ESPECIALLY FROM MYRTLE BEACH TO SOUTHPORT. THE HRRR`S
TRACK RECORD IS NOT TOO GOOD SO WE`LL KEEP THE PROBABILITY OF NEW
SHOWERS AND STORMS IN THE "ISOLATED" CATEGORY FOR NOW. PREVIOUS
DISCUSSION FROM 1030 PM SATURDAY FOLLOWS...
THE DECAYING SEA BREEZE WILL RESULT IN SSW-SW WINDS 15 TO
OCCASIONALLY 20 KT THROUGH THIS MID-EVENING HRS ...BEFORE FINALLY
BACKING DOWN TO SW 10 TO 15 KT DURING THE PRE-DAWN HRS OF SUNDAY.
THE SFC PG WILL NOT BE NEARLY AS TIGHT LIKE THE PREVIOUS FEW
DAYS...AND THE NOCTURNAL 925MB JET IS NOT AS PRONOUNCED LIKE THE
PREVIOUS FEW DAYS. THUS...THE REASONS FOR THE LOWER FORECAST WIND
SPEEDS FOR THE OVERNIGHT INTO SUNDAY. SIG SEAS WILL RUN 2 TO 4 FT
AND BE RULED BY THE 5 TO 6 SECOND SHORT PERIOD LOCALLY PRODUCED WIND
DRIVEN WAVES. WAVEWATCH3 ILLUSTRATES AN INCREASE OF THE 9-10 SECOND
PERIOD ESE GROUND SWELL FROM 1/2 FT THIS EVENING TO 1+ FT BY SUNRISE
SUNDAY. THIS WILL OFFSET THE SUBSIDING WIND DRIVEN WAVE HEIGHTS AS A
RESULT OF THE DIMINISHING WIND FIELD.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 PM SATURDAY...SOUTHWEST FLOW WILL CONTINUE BETWEEN
BERMUDA HIGH TO THE EAST AND PIEDMONT TROUGH OVER INLAND
CAROLINAS. NAM SHOWING DECENT LOW LEVEL JETTING BOTH SUN AND MON
NIGHT BUT STRONGER MON NIGHT AS WINDS ALOFT INCREASE UP TO 25 TO
30 KTS. OVERALL EXPECT SFC WINDS AROUND 15 KTS SUNDAY INCREASING
UP TO 15 TO 20 KTS ON MONDAY AND VEERING SLIGHTLY MORE TO THE
W-SW. EACH AFTERNOON WINDS WILL BECOME SLIGHTLY MORE ON SHORE AND
GUSTIER CLOSE TO THE COAST AS SEA BREEZE DEVELOPS. WNA SHOWING
LONGER PERIOD UP TO 10 SECOND SWELLS MIXING WITH LOCALLY DRIVEN
WIND WAVES TO PRODUCE SEAS 2 TO 4 FT. SHOULD REACH UP TO 4 TO 5 FT
IN OUTER WATERS MON NIGHT IN STRONGER W-SW WINDS.
LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 300 PM SATURDAY...TYPICAL SUMMERTIME PATTERN THROUGH THE
EXTENDED WITH PERSISTENT SW RETURN FLOW DOMINATING THE SYNOPTIC
WIND. SW WINDS OF 15-20 KTS WILL OCCUR ON BOTH TUESDAY AND
WEDNESDAY...EASING TO AROUND 10 KTS AND VEERING TO SLIGHTLY MORE
W/SW BY THURSDAY AS A BACK DOOR TYPE FRONT APPROACHES FROM THE
NORTH. THESE SW WINDS WILL KEEP A 4-5FT/5SEC SW WIND WAVE ONGOING
THROUGH THE PERIOD...ALTHOUGH AMPLITUDE WILL DECAY SLIGHTLY ON
THURSDAY. AT THE SAME TIME...THE PERSISTENT FLOW AROUND HIGH
PRESSURE RIDGE OVER THE ATLANTIC WILL KEEP A SE GROUND SWELL PRESENT
WITHIN THE WAVE SPECTRUM. SWELL INITIALLY OF 2FT/9SEC WILL BECOME
2FT/13 SEC BY THURSDAY. SEAS OF 3-5 FT TUESDAY WILL SLOWLY
DECREASE...BECOMING 2-3 FT THURSDAY THANKS TO EASING WINDS AND THE
LONGER PERIOD SWELL DECAYING MORE QUICKLY DUE TO OCEAN BOTTOM
FRICTION.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...DCH/TRA
SHORT TERM...RGZ
LONG TERM...JDW
AVIATION...HDL/TRA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
954 PM CDT MON JUL 23 2012
.DISCUSSION...A LINE OF THUNDERSTORMS WILL CONTINUE TO PUSH EAST
ACROSS EASTERN MONTANA AND WILL APPROACHING MT/ND BORDER AROUND 06Z.
THE SHORT RANGE MODEL GUIDANCE HAS BEEN TOO SLOW WITH THESE STORMS
WITH THE HRRR CONSISTENTLY SHOWING A FASTER PROGRESSION OF
CONVECTION WITH EACH HOURLY MODEL RUN. AS A RESULT...UPDATED THE
EVENING FORECAST TO ADD TEMPORAL RESOLUTION TO THE FIRST PERIOD
POPS AFTER MIDNIGHT. THIS ALSO NUDGED POPS A LITTLE FARTHER EAST
FOR THE TUESDAY MORNING PERIOD. THESE STORMS ARE EXPECTED TO
REMAIN BELOW SEVERE LIMITS AS THEY PUSH INTO WESTERN NORTH DAKOTA
AFTER MIDNIGHT. AS A RESULT...WILL KEEP SEVERE WORDING OUT OF THE
FORECAST FOR TONIGHT. THE REMAINING WEATHER ELEMENTS ARE IN GOOD
SHAPE. THE UPDATED GRIDDED AND TEXT PRODUCTS WILL BE OUT SHORTLY.
&&
.AVIATION...A SLOW MOVING COLD FRONT WILL BEGIN TO AFFECT THE
WESTERN NORTH DAKOTA TERMINAL AERODROMES (KISN/KDIK) AROUND 09Z
TUESDAY. THUNDERSTORMS SHOULD CREATE BRIEF PERIODS OF MVFR
CONDITIONS. HOWEVER...DUE TO THE TIMING UNCERTAINTY...INDICATED
VCTS IN THE AFFECTED TAFS. THE THUNDERSTORMS WILL SLOWLY PROGRESS
EAST AND IMPACT KMOT/KBIS BETWEEN 18Z-21Z TUESDAY. KJMS WILL
LIKELY SEE THUNDERSTORM ACTIVITY TOWARDS THE END OF THE TAF
PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
TM...UPDATE/AVIATION
AREA FORECAST DISCUSSION
NWS BISMARCK ND
714 PM CDT MON JUL 23 2012
.DISCUSSION...THUNDERSTORMS ARE DEVELOPING ALONG A COLD FRONT
MOVING ACROSS CENTRAL MONTANA. THE SHORT RANGE MODEL GUIDANCE
SUGGESTS THAT THIS ACTIVITY SHOULD HOLD TOGETHER AS THE FRONT
MOVES INTO EASTERN MONTANA. THE LATEST HRRR IS THE FASTEST
SOLUTION PUSHING THIS ACTIVITY INTO WESTERN NORTH DAKOTA AROUND
06Z TONIGHT. THE ECMWF/GEM/NAM PUSH IT INTO WESTERN NORTH DAKOTA
AROUND 12Z. DUE TO THE TIMING UNCERTAINTY...BROAD-BRUSHED HIGH-END
CHANCE POPS NORTHWEST FOR THE 06Z-12Z PERIOD. OTHERWISE...THE
REMAINING WEATHER ELEMENTS ARE IN GOOD SHAPE. THE UPDATED GRIDDED
AND TEXT PRODUCTS HAVE BEEN SENT.
&&
.AVIATION...A SLOW MOVING COLD FRONT WILL BEGIN TO AFFECT THE
WESTERN NORTH DAKOTA TERMINAL AERODROMES (KISN/KDIK) AROUND 10Z
TUESDAY. THUNDERSTORMS SHOULD CREATE BRIEF PERIODS OF MVFR
CONDITIONS. HOWEVER...DUE TO THE TIMING UNCERTAINTY...INDICATED
VCTS IN THE AFFECTED TAFS. THE THUNDERSTORMS WILL SLOWLY PROGRESS
EAST AND IMPACT KMOT/KBIS BETWEEN 18Z-21Z TUESDAY. KJMS WILL
LIKELY SEE THUNDERSTORM ACTIVITY TOWARDS THE END OF THE TAF
PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
TM...UPDATE/AVIATION
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1027 PM EDT MON JUL 23 2012
.SYNOPSIS...
A COLD FRONT WILL PUSH SOUTH INTO THE OHIO VALLEY ON TUESDAY. THIS
FRONT WILL WEAKEN AND THEN LIFT NORTHWARD AS A WARM FRONT ON
WEDNESDAY. IN THE WEAK WESTERLY FLOW ALOFT...A SURFACE LOW WILL
DEVELOP OVER THE GREAT LAKES AND SLOWLY MOVE EAST...PUSHING A COLD
FRONT THROUGH THE OHIO VALLEY THURSDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
CONDITIONS ARE QUIESCENT ACROSS THE REGION THIS EVENING AND SHOULD
REMAIN THAT WAY INTO THE LATE NIGHT. LARGE AREA OF MID CLOUDS WILL
SPREAD SOUTHEAST ACROSS THE REGION. THESE CLOUDS ALONG WITH SOUTH
SOUTHWEST WINDS STAYING UP WILL RESULT IN RATHER WARM LOWS. HAVE
BUMPED THEM UP SLIGHTLY.
BIG QUESTION IS WHETHER SHOWERS AND THUNDERSTORMS WILL DEVELOP
LATE TONIGHT AND MOVE INTO THE REGION BEFORE DAYBREAK. LOOKS LIKE
THE 00Z NAM IS DELAYING THIS PRECIPITATION UNTIL TUESDAY. BUT
SEVERAL RUNS OF THE HRRR ALONG WITH SEVERAL 18Z SYNOPTIC MODELS
ARE BRINGING STORMS INTO THE WESTERN PART OF THE FORECAST AREA.
HAVE TAILORED FORECAST ALONG THESE LINES AND BROUGHT POPS IN FROM
THE NORTHWEST LATE.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
STORM DEVELOPMENT SHOULD CONTINUE SOUTHEAST ACROSS THE FORECAST
AREA THROUGH THE DAY AS A FRONT SAGS INTO THE REGION. AS THE
COLD FRONT SAGS INTO KENTUCKY TUESDAY...THERE IS AN INCREASED
CHANCE FOR RAIN RUNNING NORTHWEST TO SOUTHEAST THROUGH NORTHERN
KENTUCKY OVERNIGHT. THE DAYTIME HOURS WILL SEE A BIT MUCH MIXING
THAT THE CHANCE FOR DEVELOPMENT IS DECREASING ON WEDNESDAY AS THE
FRONT LIFTS NORTHWARD AS A WARM FRONT. IT WILL BE EVEN HARDER IN A
WARM ADVECTION PATTERN TO SPARK STORMS OVERNIGHT WEDNESDAY AS THE
NECESSARY FORCING IS NOWHERE TO BE FOUND OVER THE OHIO VALLEY.
WHILE THE MECHANISMS FOR STORMS OVER THE NEXT FEW DAYS APPEAR
LACKING...THE ENVIRONMENT IS SUPPORTIVE OF THEM AND ANY LINGERING
BOUNDARIES OR ONGOING CONVECTION MAY INSTIGATE DEVELOPMENT AS WELL
SO A DRY FORECAST IS NOT PRUDENT.
HIGH TEMPERATURES WITHIN A FEW DEGREES OF 90...COOLEST IN
NORTHEAST CWA AND LOWS IN THE UPPER 60S TO LOWER 70S SEEM
REASONABLE THROUGH MID WEEK.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
MODELS SHOW DESCENT AGREEMENT WITH THE PATTERN OVER THE REGION AT
THE BEGINNING OF THE PERIOD. IN A NW FLOW FROM RIDGING OVER THE
ROCKIES...THEY PLACE A S/W DROPPING ACROSS THE LAKES. THE GFS HAS
MORE ENERGY WITH AN INITIAL WAVE AND IS THEREFORE STRONGER WITH
ITS SURFACE REFLECTION. THE OTHER EXTENDED MODELS ARE MORE MUTED
WITH THIS LOW...SO WILL LEAN TOWARDS THE CONSENSUS. AT THE SFC ON
THURSDAY THE REGION IS WARM SECTORED...SO CANT RULE OUT SOME POP
UP CONVECTION. PUT THE HIGHEST POPS IN THE N CLOSER TO THE S/W
WITH GRADUALLY DECREASING POPS AS YOU HEAD S.
THE MAIN H5 S/W SWINGS ACROSS THE LAKES THU NGT INTO FRI. THIS
PULLS A CDFNT THROUGH THE REGION. EXPECT CONVECTION ALONG THE
FRONT...BUT SINCE FROPA APPEARS TO BE MAINLY THU NGT...ONLY KEPT
POPS IN THE CHC CATEGORY. THE S/W DOESNT SWING THRU UNTIL
FRIDAY...SO THIS SHOULD STALL THE MOVEMENT OF THE FRONT EWD AND
SHOULD KICKOFF ADDITION CONVECTION ON FRIDAY. WENT WITH THE HIGHER
POPS IN THE E ON FRIDAY.
WEAK HIGH PRESSURE BUILDS IN FOR SATURDAY INTO SUNDAY. LOOKS LIKE A
WRMFNT MIGHT BE PUSHED OUT OF THE PLAINS INTO THE REGION FOR
MONDAY...BRINGING ANOTHER CHANCE OF PCPN.
FOR TEMPERATURES...LOOKS LIKE THURSDAY WITH BE THE HOTTEST DAY WITH
THE REGION WARM SECTORED. USED A BLEND OF ECMWF/HPC GUIDANCE...WHICH
PUTS HIGHS ON THU IN THE LOWER TO MID 90S. TEMPERATURES FALL BACK
INTO THE UPPER 80S FRIDAY DUE TO THE CLOUD COVER AND CONVECTION. THE
WEEKEND TEMPERATURES LOOK TO STAY IN THE MID TO UPPER 80S.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
ONLY EXPECT A FEW CLOUDS FOR THE EARLY PART OF THE TAF PERIOD. A
DISTURBANCE WILL DROP SOUTHEAST ACROSS THE REGION LATE TONIGHT
INTO TOMORROW. IT APPEARS THAT INITIALLY THERE WILL BE PRIMARILY A
MID DECK BUT THERE COULD BE A FEW HIGH BASED SHOWERS OR
THUNDERSTORMS WITHIN THAT. SEEMS THAT A BETTER CHANCE OF STORMS
WILL COME AFTER 12Z. UNCERTAINTY REGARDING CONVECTIVE EVOLUTION
INCREASES FURTHER OUT IN TIME. THERE IS SOME SUGGESTION THAT THE
CHANCE OF STORMS WILL CONTINUE AFTER 18Z IN THE CINCINNATI AREA.
BUT UNCERTAINTY PRECLUDES ANY PRECIPITATION BEING USED IN THE
TAFS THAT FAR OUT. SOUTHWEST WINDS WILL VEER TO WESTERLY TOWARDS
12Z AND THEN SWITCH MORE TO THE NORTHWEST LATE IN THE TAF PERIOD.
OUTLOOK...THUNDERSTORMS POSSIBLE TUESDAY NIGHT AND WEDNESDAY AND
THEN AGAIN THURSDAY AFTERNOON INTO FRIDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...FRANKS
NEAR TERM...
SHORT TERM...FRANKS
LONG TERM...SITES
AVIATION...
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
630 AM CDT SUN JUL 22 2012
.AVIATION...
ELEVATED THUNDERSTORMS HAVE DEVELOPED THIS MORNING SOUTH OF THE
METROPLEX IN ASSOCIATION WITH A SUBTLE EASTERLY WAVE. ACTIVITY
EXTENDS SOUTHWARD BEYOND THE SOUTHERN CWA AND WILL LIKELY AFFECT
THE WACO TERMINAL PERIODICALLY OVER THE NEXT FEW HOURS. WILL
INCLUDE VCTS FOR KACT THROUGH 14Z...WITH THE THOUGHT THAT ACTIVITY
WILL SHIFT WEST AND WEAKEN AFTER SUNRISE. THE HRRR HAS DONE A GOOD
JOB SO FAR AND ALSO INDICATES WEAKENING AFTER 13Z. SO FAR STORMS
HAVE REMAINED SOUTH OF TARRANT AND DALLAS COUNTIES...AND WILL
LIKELY LEAVE OUT MENTION OF TS AT METROPLEX-AREA TERMINALS UNLESS
FUTURE TRENDS DEMAND OTHERWISE. IR LOOP DOES SHOW ACCAS SPREADING
ACROSS THE METROPLEX...SO MAY INCLUDE A VCSH FOR THE NEXT FEW
HOURS DUE TO THE POSSIBILITY OF A FEW ELEVATED SHOWERS DEVELOPING
IN THE AREA. ISOLATED STORMS MAY AGAIN BECOME POSSIBLE THIS
AFTERNOON BUT COVERAGE SHOULD REMAIN LOWER THAN THE PAST FEW DAYS.
AT THIS TIME...FEEL THE CHANCE WILL BE TOO LOW TO MENTION AT TAF
SITES. VFR CONDITIONS WITH SOUTH WINDS AROUND 10KT WILL CONTINUE
IN THE EVENING AND OVERNIGHT FORECASTS.
30
&&
.PREV DISCUSSION... /ISSUED 402 AM CDT SUN JUL 22 2012/
12Z UPPER AIR ANALYSIS INDICATED AN ELONGATED CYCLONIC SHEAR AXIS
AT THE H250 LEVEL EXTENDING FROM THE CAROLINAS WEST OVER THE
SOUTHEASTERN CONUS AND OVER THE RED RIVER IN THE SOUTHERN PLAINS.
ALTHOUGH SUBTLE...H700 STREAMLINES HINT AT A WEAK MID-LEVEL
DISTURBANCE OVER THE WESTERN GOMEX WITH LA AND TX COASTAL UPPER
AIR OBSERVATIONS HINT AT WEAK CYCLONIC CURVATURE. WATER VAPOR
IMAGERY DEPICTS THE ELONGATED SHEAR AXIS WELL AS A POCKET OF DRIER
AIR WITH A COUPLE OF EMBEDDED CYCLONIC EDDIES. ONE OF THESE EDDIES
WAS LOCATED OVER THE NORTHEASTERN PORTIONS OF THE CWA EARLY THIS
MORNING...AND WAS MOVING WEST-SOUTHWEST. REGIONAL RADARS INDICATED
ISOLATED THUNDERSTORM AND RAIN SHOWER ACTIVITY ALONG A LINE FROM
LUFKIN TOWARDS GOLDTHWAITE MOVING SOUTH AS OF 08Z.
TODAY AND TONIGHT...THE CYCLONIC CIRCULATION OVER THE NORTHEASTERN
CWA EARLY THIS MORNING IS ESSENTIALLY A WEAK SHORTWAVE TROUGH.
THIS FEATURE WILL CONTINUE TO MOVE WEST-SOUTHWEST THIS MORNING
PROVIDING SOME VERY WEAK LARGE SCALE FORCING FOR ASCENT OVER NORTH
TX. AS A RESULT WENT AHEAD AND KEPT A MENTION OF ISOLATED
THUNDERSTORMS IN ACROSS NORTH TX THIS MORNING AS SOME ELEVATED
THUNDERSTORM ACTIVITY CANNOT BE RULED OUT. ANY STORMS THAT DEVELOP
THIS MORNING ARE NOT EXPECTED TO BE STRONG OR SEVERE BUT COULD
PRODUCE CLOUD TO GROUND LIGHTNING. THIS TROUGH IS EXPECTED TO MOVE
WEST OF THE FORECAST AREA THIS AFTERNOON LEAVING WEAK FORCING FOR
SUBSIDENCE IN ITS WAKE. DESPITE WEAK SUBSIDENCE OVER THE AREA THIS
AFTERNOON...FORECAST SOUNDINGS FROM MOST GUIDANCE INDICATE AN
UNCAPPED ATMOSPHERE OVER NORTH AND CENTRAL TX. WITHOUT ANY
SIGNIFICANT FORCING TO FOCUS CONVECTION...WENT AHEAD AND LOWERED
POPS TO 10 PERCENT FOR ALL LOCATIONS AND ONLY MENTIONED ISOLATED
THUNDERSTORMS THROUGH THIS EVENING. ANY STORMS THAT DEVELOP ARE
EXPECTED TO BE PULSE TYPE STORMS PRIMARILY CAPABLE OF PRODUCING
MICROBURST WINDS. STORMS ARE NOT EXPECTED TO HOLD TOGETHER LONG
ENOUGH TO BE HAIL OR HEAVY RAIN PRODUCERS AT THIS TIME. EXPECT ANY
THUNDERSTORM ACTIVITY WILL DISSIPATE QUICKLY AROUND SUNSET.
AS THE SHORTWAVE MOVES WEST OF THE CWA...SURFACE LOW PRESSURE IS
EXPECTED TO FOLLOW SUIT WITH THE SURFACE LOW NEAR WICHITA FALLS
EARLY THIS MORNING EXPECTED TO MOVE TOWARDS GUTHRIE BY 21Z THIS
AFTERNOON. THIS IS IMPORTANT FOR NORTH AND CENTRAL TX BECAUSE
WHILE THE LOW REMAINS IN PLACE NEAR WICHITA FALLS...LOW LEVEL WIND
FIELDS MAINTAIN A WEST-SOUTHWESTERLY COMPONENT WHICH EQUATES TO
WEAK WARM AIR ADVECTION FOR AREAS GENERALLY ALONG AND WEST OF THE
INTERSTATE 35/35E CORRIDOR. CONSIDERING WE HAD ANOTHER DAY OF
RECORD HEAT YESTERDAY...WEAK WARM AIR ADVECTION WOULD NOT BRING
MUCH RELIEF FROM THE HEAT. ASSUMING THE SURFACE LOW MOVES WEST AS
EXPECTED BY THIS AFTERNOON...THIS SHOULD ALLOW LOW LEVEL WIND
FIELDS TO BACK AROUND TOWARDS THE SOUTH-SOUTHEAST WHICH WILL
RESULT IN COLD AIR ADVECTION AND COOLER TEMPERATURES FOR MUCH OF
NORTH AND CENTRAL TX. BECAUSE THIS TRANSITION TO COLD AIR
ADVECTION IS NOT EXPECTED UNTIL LATER IN THE DAY...HIGHS WILL
LIKELY TOP OUT ABOVE THE CENTURY MARK FOR THE WESTERN HALF OF THE
CWA ONCE AGAIN TODAY.
LOW LEVEL THICKNESS VALUES CONTINUE TO BE GREATER ALONG AND NORTH
OF INTERSTATE 20 TODAY...SO EXPECT THE WARMEST TEMPERATURES TO
OCCUR OVER THE NORTHWESTERN CWA WHERE HIGHS MAY ONCE AGAIN PEAK OUT
NEAR 105 DEGREES EARLY THIS AFTERNOON. SPC MESOANALYSIS INDICATES
THAT THE EASTERN HALF OF THE FORECAST AREA REMAINS VERY MOIST
DESPITE YESTERDAYS THUNDERSTORM ACTIVITY. MESOANALYSIS INDICATES
PWAT VALUES OF 1.8 INCHES EAST OF THE INTERSTATE 35 CORRIDOR AS OF
08Z. WHEN FACTORING IN HIGHER AFTERNOON RH VALUES WITH TODAYS
FORECAST HIGHS...HEAT INDEX VALUES ARE ONCE AGAIN EXPECTED TO TOP
OUT ABOVE THE 105 DEGREE MARK FOR THE NORTHERN HALF OF THE
FORECAST AREA. WILL MAINTAIN THE HEAT ADVISORY FOR THESE LOCATIONS
THROUGH THIS AFTERNOON AS A RESULT. SOUTHEASTERLY FLOW IS EXPECTED
TO PERSIST INTO EARLY NEXT WEEK WHICH WILL KEEP WEAK COLD AIR
ADVECTION IN PLACE AND SHOULD PREVENT ANY EXTENSION OF THE HEAT
ADVISORY INTO MONDAY.
MONDAY...SUNDAY NIGHT AND INTO MONDAY MODELS CONSISTENTLY BRING
THE WEAK MID-LEVEL CYCLONIC FEATURE OVER THE WESTERN GOMEX WEST
OVER SOUTH TX. EARLY MORNING WATER VAPOR IMAGERY DOES NOT SEEM TO
HAVE THIS FEATURE RESOLVED...SO THE ASSUMPTION IS THAT THIS SYSTEM
IS STRONGEST AT THE MID-LEVELS AND POSSIBLY REPRESENTS THE
REMNANTS OF OLD THUNDERSTORM ACTIVITY. EITHER WAY THIS FEATURE
LOOKS TO REMAIN JUST SOUTH OF THE FORECAST AREA AND SHOULD NOT
HAVE ANY DIRECT IMPACT ON PRECIPITATION CHANCES DURING THE DAY ON
MONDAY. AS THIS FEATURE MOVES WEST...IT WILL ALLOW SOUTHEASTERLY
FLOW TO DEEPEN OVER NORTH AND CENTRAL TX AND MODELS RESPOND BY
BRINGING PWATS UP TO NEARLY 2 INCHES ACROSS THE EASTERN TWO-THIRDS
OF THE CWA BY MONDAY AFTERNOON. THE GFS INDICATES THAT A PIECE OF
ENERGY FROM THE UPPER LEVEL SHEAR AXIS WILL MOVE WEST TOWARDS THE
FORECAST AREA SUNDAY NIGHT AS THE SHEAR AXIS LOSES IDENTITY AND IS
REPLACED BY UPPER LEVEL RIDGING FOR EARLY NEXT WEEK. WITH TROPICAL
MOISTURE IN PLACE...THIS FEATURE IS EXPECTED TO ACT LIKE A TUTT
LOW AND SPREAD LARGE SCALE FORCING FOR ASCENT OVER NORTH TX AS IT
MOVES OVERHEAD MONDAY AFTERNOON. AS A RESULT WENT AHEAD AND SPREAD
THE COVERAGE OF 20 POPS TO COVER MOST AREAS ALONG AND SOUTH OF
INTERSTATE 30 AND ALONG AND EAST OF INTERSTATE 35.
IF THIS FEATURE IS REAL...POPS MAY NEED TO BE INCREASED BEFORE
MONDAY AFTERNOON AS THUNDERSTORM COVERAGE MAY BE MORE SCATTERED IN
NATURE. AT THIS TIME IT IS DIFFICULT TO PICK OUT WHICH PORTION OF
THE UPPER SHEAR AXIS IS GOING TO ORGANIZE AND MOVE WEST...SO DID
NOT HAVE THE CONFIDENCE TO GO WITH HIGHER PERCENTAGES AT THIS
TIME. IF IT PANS OUT AS THE GFS FORECASTS...LOCALLY HEAVY RAINFALL
WOULD BE POSSIBLE AS TALL-SKINNY CAPE PROFILES IN A RELATIVELY
WEAKLY SHEARED ENVIRONMENT WOULD BE EXPECTED TO BE EFFICIENT
RAINFALL PRODUCERS. WET MICROBURSTS COULD NOT BE RULED OUT...BUT
OVERALL THE ENVIRONMENT WOULD NOT SUPPORT A GOOD MICROBURST/WIND
DAMAGE THREAT.
REMAINDER OF THE FORECAST...UPPER LEVEL RIDGING IS EXPECTED TO
BUILD OVER THE WESTERN GULF WHILE THE SOUTH TX MID-LEVEL LOW MOVES
TOWARDS NEW MEXICO AND MERGES WITH OUR WESTWARD MOVING SHORTWAVE
TROUGH INTO ONE LARGE UPPER LEVEL WEAKNESS OVER THE SOUTHERN HIGH
PLAINS. IN GENERAL EXPECT WEAK UPPER RIDGING TO DOMINATE NORTH AND
CENTRAL TX...SO MAINTAINED A DRY FORECAST FOR THE REMAINDER OF THE
WEEK. PERSISTENT WEAK SUBSIDENCE WILL SLOWLY WORK AWAY AT THE
HIGH PWAT AIR OVER THE FORECAST AREA DIMINISHING THE POTENTIAL FOR
PEAK HEATING ISOLATED STORMS LATER IN THE WEEK. BECAUSE DEEP
MOISTURE WILL REMAIN IN PLACE ON TUESDAY...CANNOT RULE OUT SOME
ISOLATED STORMS DURING THE PEAK HEATING HOURS OF THE DAY...BUT DID
NOT INCLUDE ANYTHING IN THE WORDED FORECAST AS THERE IS NO
DISCERNABLE FORCING FOR ASCENT AT THIS TIME. TEMPERATURES SHOULD
REMAIN JUST ABOVE NORMAL WITH HIGHS TOPPING OUT IN THE UPPER 90S
DAILY.
CAVANAUGH
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 101 78 97 76 97 / 10 10 20 10 5
WACO, TX 100 76 96 76 97 / 10 10 20 10 5
PARIS, TX 98 74 95 73 96 / 10 10 10 10 5
DENTON, TX 101 77 98 76 97 / 10 10 10 10 5
MCKINNEY, TX 99 76 97 75 96 / 10 10 20 10 5
DALLAS, TX 101 79 97 76 97 / 10 10 20 10 5
TERRELL, TX 99 76 95 74 96 / 10 10 20 10 5
CORSICANA, TX 98 77 94 74 95 / 10 10 20 10 5
TEMPLE, TX 100 74 96 73 96 / 10 10 20 10 5
MINERAL WELLS, TX 102 74 99 73 98 / 10 10 10 10 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR TXZ091>095-100>107-
115>123.
&&
$$
30/69
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1245 PM EDT SUN JUL 22 2012
.SYNOPSIS...
A FRONTAL BOUNDARY FROM NORTH CAROLINA INTO TENNESSEE WILL
DISSIPATE TODAY. HIGH PRESSURE WILL STRETCH FROM THE CENTRAL
PLAINS TO THE SOUTHEAST COAST FROM TONIGHT INTO MONDAY. A COLD
FRONT WILL APPROACH THE AREA FROM THE NORTH BY WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1235 PM EDT SUNDAY...
IT TOOK A LITTLE WHILE BUT LOW CLOUDS ARE LIFTING/BREAKING THIS
AFTERNOON AS A WEAK SURFACE WEDGE ERODES. TEMPERATURES WARMING VERY
QUICKLY WHERE THE SUN IS OUT AND SOUTHERLY IS REESTABLISHED TO PUSH
TEMPERATURES INTO THE 80S THIS AFTERNOON. A WEAK LEE TROUGH
ACROSS THE PIEDMONT AND DECAYING SURFACE BOUNDARY OVER NORTH
CAROLINA WILL GENERATE SCATTERED SHOWERS AND THUNDERSTORMS ALONG THE
NC/VA BORDER...EAST OF THE BLUE RIDGE. CAN NOT RULE OUT A STRONG
STORM OR TWO IN THE SOUTH BUT SEVERE THREAT IS KLESS THAN 5
PERCENT.
AS OF 935 AM EDT SUNDAY...
CLOUDY SKIES WILL LINGER THROUGH MUCH OF THE MORNING...THEN SCOUR
DURING THE AFTERNOON. A FEW SHOWERS TRACKING ACROSS THE NORTH
CAROLINA AND GRAYSON HIGHLANDS THIS MORNING. THESE SHOWERS SHOULD
FADE SOME IN AREAL COVERAGE MOVING EAST...THEN REMNANTS/OUTFLOW
BOUNDARIES WILL GENERATE MORE SHOWERS AND THUNDERSTORMS THIS
AFTERNOON. MAJORITY OF THE MODELS HAVE GENEROUS POPS ACROSS RNK
SOUTHERN TIER COUNTIES THIS AFTERNOON. THEREFORE WILL MAINTAIN
SOME SHOWERS IN THE AFTERNOON WHILE KEEPING THE NORTH DRY.
AS OF 415 AM EDT SUNDAY...
RADAR SHOWED ISOLATED SHOWERS FROM SMYTH AND GRAYSON COUNTIES
INTO THE NORTHWEST NORTH CAROLINA MOUNTAINS. THEY REST OF THE
PRECIPITATION FROM EARLIER TONIGHT HAS EITHER DISSIPATED OR MOVED
SOUTHEAST OUT OF THE FORECAST AREA. VAD WIND PROFILES FROM AREA
RADARS SHOWED A NORTH TO NORTHEAST WIND IN THE LOWER 1-4KFT WITH
WEST WINDS ABOVE THIS LAYER. FRONT EXTENDING ACROSS NORTH CAROLINA
AND TENNESSEE WILL CONTINUE TO WEAKEN AND DISSIPATE TODAY WITH THE
WEDGE ERODING AND SURFACE WINDS BECOMING SOUTH TO SOUTHWEST OVER
THE FORECAST AREA BY MID AFTERNOON.
EXPECT LOW CLOUDS TO HOLD IN EAST OF THE BLUE RIDGE THIS MORNING.
EVEN IF COUNTIES IN THE NORTHEAST PART OF THE FORECAST AREA DO NOT
SCATTER OUT UNTIL LATER TODAY...EVEN JUST A COUPLE HOURS OF SUN
WILL BRING TEMPERATURES WELL INTO THE 80S. USED A NON DIURNAL
HOURLY TEMPERATURE FORECAST BASED ON THE GRIDDED LAMP GUIDANCE AND
EXPECTED CLOUD COVER.
FR PROBABILITY OF PRECIPITATION...MODELS HELD ON TO A LOW CHANCE
THIS MORNING. HRRR AND LOCAL WRF SHOWED SHOWERS AND THUNDERSTORMS
DEVELOPING THIS AFTERNOON SOUTH OF HWY 460. ADJUSTED TIMING AND
COVERAGE OF THE PRECIPITATION IN THE SOUTH THIS AFTERNOON.
ONCE STORMS DISSIPATE IN THE EVENING...LITTLE TO NO PRECIPITATION
EXPECTED OVERNIGHT. MAV GUIDANCE LOOKED REASONABLE FOR MINIMUM
TEMPERATURES.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 400 AM EDT SUNDAY...
HEIGHTS INCREASE INTO EARLY NEXT WEEK AS A SLICE OF THE UPPER RIDGE
RESPONSIBLE FOR THE HOT WEATHER ACROSS THE HEARTLAND STRETCHES
EASTWARD. H85 TEMPS WILL RISE TO AROUND +20C. CONSIDERING THE
MOVEMENT OF THE UPPER RIDGE AND ITS POSITION BY TUESDAY ...MOVING
JUST TO OUR SW WHICH WILL DELIVER A DOWNSLOPING NW COMPONENT...TEMPS
MAY VERIFY THE WARMEST GUIDANCE VALUES. MOS HAS BEEN TOO COOL WITH
TEMPS ACROSS THE MIDWEST...AND THIS MAY CONTINUE INTO THE OHIO
VALLEY AND MIDDLE ATLANTIC. GFS/NAM HAVING A HARD TIME PINPOINTING
WHICH DAY WOULD BE BEST FOR AN MCS TO ROLL THROUGH AND INSTEAD HAVE
SEVERAL WAVES OF PRECIP MOVING THROUGH MONDAY THROUGH WEDNESDAY. THIS
PROBABLY HAS LED TO SOME OF THE COOLER MAX TEMPS OFF THE MET. THE
BEST CHANCE FOR AN MCS TO APPROACH OUR REGION LOOKS TO BE LATER
TUESDAY AND TUESDAY NIGHT...AS CORFIDI VECTORS HAVE SUFFICIENT
MAGNITUDE AND DIRECTION TO LEAD SOMETHING TO SE WEST VA FROM THE NW.
ALTHOUGH IT MAY STILL OCCUR...WIDESPREAD STORMS AND HIGH QPF EARLY
TUESDAY LOOKS OVERDONE. NOT ENOUGH CONFIDENCE TO GO LIKELY BUT WILL
KEEP THE HIGHEST POPS IN THE TUESDAY PM AND TUESDAY NIGHT
TIME FRAME...WITH MORE PULSE TYPE STORMS ON MONDAY AND SMALLER POPS.
COLD FRONT DRAPED WEST TO EAST THROUGH THE GREAT LAKES ON TUESDAY
SINKS TO SE WEST VA AND NEAR NW NC INTO WEDNESDAY. THEREFORE THOSE
SPOTS HAVE THE BEST CHANCE OF STORMS CONTINUING INTO MIDWEEK.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 1222 PM EDT SATURDAY...
LOOKS LIKE WE WILL BE STUCK IN A HUMID SOMEWHAT STORMY BUT TYPICAL
LATE JULY PATTERN WITH THE RIDGE STAYING RIGHT ON THE SWRN DOORSTEP
OF OUR REGION...WITH THE BLACKSBURG FORECAST AREA REMAINING ON THE
SRN FRINGE OF THE TROUGH OVER THE NORTHEAST.
WILL BE GOING WITH DAILY THREAT OF SHRA/TSRA BUT WILL SEE ENHANCED
PROBABILITIES AS A SERIES OF SHORTWAVES GRAZE BY...BUT TIMING AT
THIS POINT IS UP IN THE AIR...WITH FRONTAL BOUNDARY SWINGING TOWARD
US IN THE WED-THU TIME FRAME THEN LIFTING NORTH AGAIN BY THE WEEKEND.
LOWS AT NIGHT WILL STAY IN THE 60S IN THE MTNS WITH LOWER 70S EAST
WITH HIGHS IN THE MID-UPPER 80S MTNS TO LOWER TO MID 90S EAST. OF
COURSE ANY CONVECTION AND OR BLOWOFF OF STORMS WILL LIMIT SOME
HEATING FROM TIME TO TIME DURING THE DAY.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
AS OF 1245 PM EDT SUNDAY...
SUB VFR CLOUDS STARTED LIFTING ACROSS THE MOUNTAINS AROUND 15Z/11A
SUNDAY. WE WILL SEE THIS TREND IN THE EAST THROUGH EARLY THIS
AFTERNOON. A FRONTAL BOUNDARY ACROSS NORTH CAROLINA BACK INTO THE
TENNESEE VALLEY GENERATING A FEW SHOWERS TOWARD ABINGTON (VJI)
LATE THIS MORNING. WITH THE SUN COMING THROUGH THE CLOUDS...EXPECT
THIS SHOWERS TO CONTINUE TO MOVE EAST AND ALONG THE NC/VA BORDER
INTO THIS EVENING. CONFIDENCE IS LOW THAT ANYONE OF THESE SHOWERS
WILL LOWER CEILINGS BELOW VFR THIS AFTERNOON. THE CHANCES FOR A
THUNDERSTORMS HITTING AN AIRPORT IS ALSO LOW. WILL TIME THE
SHOWERS AS BEST I CAN BUT LEAVE TS AND CB OUT OF THE FORECAST.
FLIGHT PATHS WILL HAVE A BETTER CHANCE OF BEING AFFECTED SOUTH OF
THE VA/NC BORDER.
NW FLOW ALOFT LOOKS TO PERSIST MONDAY THRU THURSDAY...RESULTING
IN BOUTS OF SHRA/TSRA THRU THE PERIOD. OTHERWISE EXPECTING VFR
OUTSIDE OF ANY PERIODS OF THUNDERSTORMS...AND CONTINUED LATE NIGHT
FOG THROUGH MID OR LATE WEEK.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/RCS
SHORT TERM...KM
LONG TERM...WP
AVIATION...AMS/RCS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
945 AM EDT SUN JUL 22 2012
.SYNOPSIS...
A FRONTAL BOUNDARY FROM NORTH CAROLINA INTO TENNESSEE WILL
DISSIPATE TODAY. HIGH PRESSURE WILL STRETCH FROM THE CENTRAL
PLAINS TO THE SOUTHEAST COAST FROM TONIGHT INTO MONDAY. A COLD
FRONT WILL APPROACH THE AREA FROM THE NORTH BY WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 935 AM EDT SUNDAY...
CLOUDY SKIES WILL LINGER THROUGH MUCH OF THE MORNING...THEN SCOUR
DURING THE AFTERNOON. A FEW SHOWERS TRACKING ACROSS THE NORTH
CAROLINA AND GRAYSON HIGHLANDS THIS MORNING. THESE SHOWERS SHOULD
FADE SOME IN AREAL COVERAGE MOVING EAST...THEN REMNANTS/OUTFLOW
BOUNDARIES WILL GENERATE MORE SHOWERS AND THUNDERSTORMS THIS
AFTERNOON. MAJORITY OF THE MODELS HAVE GENEROUS POPS ACROSS RNK
SOUTHERN TIER COUNTIES THIS AFTERNOON. THEREFORE WILL MAINTAIN SOME
SHOWERS IN THE AFTERNOON WHILE KEEPING THE NORTH DRY.
AS OF 415 AM EDT SUNDAY...
RADAR SHOWED ISOLATED SHOWERS FROM SMYTH AND GRAYSON COUNTIES
INTO THE NORTHWEST NORTH CAROLINA MOUNTAINS. THEY REST OF THE
PRECIPITATION FROM EARLIER TONIGHT HAS EITHER DISSIPATED OR MOVED
SOUTHEAST OUT OF THE FORECAST AREA. VAD WIND PROFILES FROM AREA
RADARS SHOWED A NORTH TO NORTHEAST WIND IN THE LOWER 1-4KFT WITH
WEST WINDS ABOVE THIS LAYER. FRONT EXTENDING ACROSS NORTH CAROLINA
AND TENNESSEE WILL CONTINUE TO WEAKEN AND DISSIPATE TODAY WITH THE
WEDGE ERODING AND SURFACE WINDS BECOMING SOUTH TO SOUTHWEST OVER
THE FORECAST AREA BY MID AFTERNOON.
EXPECT LOW CLOUDS TO HOLD IN EAST OF THE BLUE RIDGE THIS MORNING.
EVEN IF COUNTIES IN THE NORTHEAST PART OF THE FORECAST AREA DO NOT
SCATTER OUT UNTIL LATER TODAY...EVEN JUST A COUPLE HOURS OF SUN
WILL BRING TEMPERATURES WELL INTO THE 80S. USED A NON DIURNAL
HOURLY TEMPERATURE FORECAST BASED ON THE GRIDDED LAMP GUIDANCE AND
EXPECTED CLOUD COVER.
FR PROBABILITY OF PRECIPITATION...MODELS HELD ON TO A LOW CHANCE
THIS MORNING. HRRR AND LOCAL WRF SHOWED SHOWERS AND THUNDERSTORMS
DEVELOPING THIS AFTERNOON SOUTH OF HWY 460. ADJUSTED TIMING AND
COVERAGE OF THE PRECIPITATION IN THE SOUTH THIS AFTERNOON.
ONCE STORMS DISSIPATE IN THE EVENING...LITTLE TO NO PRECIPITATION
EXPECTED OVERNIGHT. MAV GUIDANCE LOOKED REASONABLE FOR MINIMUM
TEMPERATURES.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 400 AM EDT SUNDAY...
HEIGHTS INCREASE INTO EARLY NEXT WEEK AS A SLICE OF THE UPPER RIDGE
RESPONSIBLE FOR THE HOT WEATHER ACROSS THE HEARTLAND STRETCHES
EASTWARD. H85 TEMPS WILL RISE TO AROUND +20C. CONSIDERING THE
MOVEMENT OF THE UPPER RIDGE AND ITS POSITION BY TUESDAY ...MOVING
JUST TO OUR SW WHICH WILL DELIVER A DOWNSLOPING NW COMPONENT...TEMPS
MAY VERIFY THE WARMEST GUIDANCE VALUES. MOS HAS BEEN TOO COOL WITH
TEMPS ACROSS THE MIDWEST...AND THIS MAY CONTINUE INTO THE OHIO
VALLEY AND MIDDLE ATLANTIC. GFS/NAM HAVING A HARD TIME PINPOINTING
WHICH DAY WOULD BE BEST FOR AN MCS TO ROLL THROUGH AND INSTEAD HAVE
SEVERAL WAVES OF PRECIP MOVING THROUGH MONDAY THROUGH WEDNESDAY. THIS
PROBABLY HAS LED TO SOME OF THE COOLER MAX TEMPS OFF THE MET. THE
BEST CHANCE FOR AN MCS TO APPROACH OUR REGION LOOKS TO BE LATER
TUESDAY AND TUESDAY NIGHT...AS CORFIDI VECTORS HAVE SUFFICIENT
MAGNITUDE AND DIRECTION TO LEAD SOMETHING TO SE WEST VA FROM THE NW.
ALTHOUGH IT MAY STILL OCCUR...WIDESPREAD STORMS AND HIGH QPF EARLY
TUESDAY LOOKS OVERDONE. NOT ENOUGH CONFIDENCE TO GO LIKELY BUT WILL
KEEP THE HIGHEST POPS IN THE TUESDAY PM AND TUESDAY NIGHT
TIME FRAME...WITH MORE PULSE TYPE STORMS ON MONDAY AND SMALLER POPS.
COLD FRONT DRAPED WEST TO EAST THROUGH THE GREAT LAKES ON TUESDAY
SINKS TO SE WEST VA AND NEAR NW NC INTO WEDNESDAY. THEREFORE THOSE
SPOTS HAVE THE BEST CHANCE OF STORMS CONTINUING INTO MIDWEEK.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 1222 PM EDT SATURDAY...
LOOKS LIKE WE WILL BE STUCK IN A HUMID SOMEWHAT STORMY BUT TYPICAL
LATE JULY PATTERN WITH THE RIDGE STAYING RIGHT ON THE SWRN DOORSTEP
OF OUR REGION...WITH THE BLACKSBURG FORECAST AREA REMAINING ON THE
SRN FRINGE OF THE TROUGH OVER THE NORTHEAST.
WILL BE GOING WITH DAILY THREAT OF SHRA/TSRA BUT WILL SEE ENHANCED
PROBABILITIES AS A SERIES OF SHORTWAVES GRAZE BY...BUT TIMING AT
THIS POINT IS UP IN THE AIR...WITH FRONTAL BOUNDARY SWINGING TOWARD
US IN THE WED-THU TIME FRAME THEN LIFTING NORTH AGAIN BY THE WEEKEND.
LOWS AT NIGHT WILL STAY IN THE 60S IN THE MTNS WITH LOWER 70S EAST
WITH HIGHS IN THE MID-UPPER 80S MTNS TO LOWER TO MID 90S EAST. OF
COURSE ANY CONVECTION AND OR BLOWOFF OF STORMS WILL LIMIT SOME
HEATING FROM TIME TO TIME DURING THE DAY.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
AS OF 145 AM EDT SUNDAY...
GRIDDED LAMP GUIDANCE HAD CLOUDS LIFTING TO MVFR AROUND 16Z AT
ROA/LYH/DAN AND BCB BUT CONFIDENCE IS LOW THAT IMPROVEMENT WILL BE
THAT QUICK. THINK ALL LOCATIONS SHOULD FINALLY REACH VFR CIGS BY
MID AFTERNOON WITH LYH LIKELY BEING THE LAST AIRPORT TO SCATTER
OUT THE LOW CLOUDS.
ONCE CLOUDS BURN OFF...AN UPPER LEVEL TROUGH AND AFTERNOON
HEATING MAY GENERATE AN ISOLATED SHOWER OR THUNDERSTORM THIS
AFTERNOON BUT TOO ISOLATED TO INCLUDE MENTION IN THE TAFS.
FOG MAY REFORM ACROSS THE MOUNTAIN VALLEYS TONIGHT INTO MONDAY
MORNING. HAVE ADDED LIFR FOG IN THE GREENBRIER VALLEY FOR THE LWB
AIRPORT.
NW FLOW ALOFT LOOKS TO PERSIST MONDAY THRU THURSDAY...RESULTING
IN BOUTS OF SHRA/TSRA THRU THE PERIOD. OTHERWISE EXPECTING VFR
OUTSIDE OF ANY PERIODS OF THUNDERSTORMS...AND CONTINUED LATE NIGHT
FOG THROUGH MID OR LATE WEEK.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/RCS
SHORT TERM...KM
LONG TERM...WP
AVIATION...AMS/JH
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
725 AM EDT SUN JUL 22 2012
.SYNOPSIS...
A FRONTAL BOUNDARY FROM NORTH CAROLINA INTO TENNESSEE WILL
DISSIPATE TODAY. HIGH PRESSURE WILL STRETCH FROM THE CENTRAL
PLAINS TO THE SOUTHEAST COAST FROM TONIGHT INTO MONDAY. A COLD
FRONT WILL APPROACH THE AREA FROM THE NORTH BY WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 415 AM EDT SUNDAY...
RADAR SHOWED ISOLATED SHOWERS FROM SMYTH AND GRAYSON COUNTIES INTO
THE NORTHWEST NORTH CAROLINA MOUNTAINS. THEY REST OF THE
PRECIPITATION FROM EARLIER TONIGHT HAS EITHER DISSIPATED OR MOVD
SOUTHEAST OUT OF THE FORECAST AREA. VAD WIND PROFILES FROM AREA
RADARS SHOWED A NORTH TO NORTHEAST WIND IN THE LOWER 1-4KFT WITH
WEST WINDS ABOVE THIS LAYER. FRONT EXTENDING ACROSS NORTH CAROLINA
AND TENNESSEE WILL CONTINUE TO WEAKEN AND DISSIPATE TODAY WITH
THE WEDGE ERODING AND SURFACE WINDS BECOMING SOUTH TO SOUTHWEST
OVER THE FORECAST AREA BY MID AFTERNOON.
EXPECT LOW CLOUDS TO HOLD IN EAST OF THE BLUE RIDGE THIS MORNING.
EVEN IF COUNTIES IN THE NORTHEAST PART OF THE FORECAST AREA DO NOT
SCATTER OUT UNTIL LATER TODAY...EVEN JUST A COUPLE HOURS OF SUN
WILL BRING TEMPERATURES WELL INTO THE 80S. USED A NON DIURNAL
HOURLY TEMPERATURE FORECAST BASED ON THE GRIDDED LAMP GUIDANCE AND
EXPECTED CLOUD COVER.
FR PROBABILITY OF PRECIPITATION...MODELS HELD ON TO A LOW CHANCE
THIS MORNING. HRRR AND LOCAL WRF SHOWED SHOWERS AND THUNDERSTORMS
DEVELOPING THIS AFTERNOON SOUTH OF HWY 460. ADJUSTED TIMING AND
COVERAGE OF THE PRECIPITATION IN THE SOUTH THIS AFTERNOON.
ONCE STORMS DISSIPATE IN THE EVENING...LITTLE TO NO PRECIPITATION
EXPECTED OVERNIGHT. MAV GUIDANCE LOOKED REASONABLE FOR MINIMUM
TEMPERATURES.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 400 AM EDT SUNDAY...
HEIGHTS INCREASE INTO EARLY NEXT WEEK AS A SLICE OF THE UPPER RIDGE
RESPONSIBLE FOR THE HOT WEATHER ACROSS THE HEARTLAND STRETCHES
EASTWARD. H85 TEMPS WILL RISE TO AROUND +20C. CONSIDERING THE
MOVEMENT OF THE UPPER RIDGE AND ITS POSITION BY TUESDAY ...MOVING
JUST TO OUR SW WHICH WILL DELIVER A DOWNSLOPING NW COMPONENT...TEMPS
MAY VERIFY THE WARMEST GUIDANCE VALUES. MOS HAS BEEN TOO COOL WITH
TEMPS ACROSS THE MIDWEST...AND THIS MAY CONTINUE INTO THE OHIO
VALLEY AND MIDDLE ATLANTIC. GFS/NAM HAVING A HARD TIME PINPOINTING
WHICH DAY WOULD BE BEST FOR AN MCS TO ROLL THROUGH AND INSTEAD HAVE
SEVERAL WAVES OF PRECIP MOVING THROUGH MONDAY THROUGH WEDNESDAY. THIS
PROBABLY HAS LED TO SOME OF THE COOLER MAX TEMPS OFF THE MET. THE
BEST CHANCE FOR AN MCS TO APPROACH OUR REGION LOOKS TO BE LATER
TUESDAY AND TUESDAY NIGHT...AS CORFIDI VECTORS HAVE SUFFICIENT
MAGNITUDE AND DIRECTION TO LEAD SOMETHING TO SE WEST VA FROM THE NW.
ALTHOUGH IT MAY STILL OCCUR...WIDESPREAD STORMS AND HIGH QPF EARLY
TUESDAY LOOKS OVERDONE. NOT ENOUGH CONFIDENCE TO GO LIKELY BUT WILL
KEEP THE HIGHEST POPS IN THE TUESDAY PM AND TUESDAY NIGHT
TIME FRAME...WITH MORE PULSE TYPE STORMS ON MONDAY AND SMALLER POPS.
COLD FRONT DRAPED WEST TO EAST THROUGH THE GREAT LAKES ON TUESDAY
SINKS TO SE WEST VA AND NEAR NW NC INTO WEDNESDAY. THEREFORE THOSE
SPOTS HAVE THE BEST CHANCE OF STORMS CONTINUING INTO MIDWEEK.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 1222 PM EDT SATURDAY...
LOOKS LIKE WE WILL BE STUCK IN A HUMID SOMEWHAT STORMY BUT TYPICAL
LATE JULY PATTERN WITH THE RIDGE STAYING RIGHT ON THE SWRN DOORSTEP
OF OUR REGION...WITH THE BLACKSBURG FORECAST AREA REMAINING ON THE
SRN FRINGE OF THE TROUGH OVER THE NORTHEAST.
WILL BE GOING WITH DAILY THREAT OF SHRA/TSRA BUT WILL SEE ENHANCED
PROBABILITIES AS A SERIES OF SHORTWAVES GRAZE BY...BUT TIMING AT
THIS POINT IS UP IN THE AIR...WITH FRONTAL BOUNDARY SWINGING TOWARD
US IN THE WED-THU TIME FRAME THEN LIFTING NORTH AGAIN BY THE WEEKEND.
LOWS AT NIGHT WILL STAY IN THE 60S IN THE MTNS WITH LOWER 70S EAST
WITH HIGHS IN THE MID-UPPER 80S MTNS TO LOWER TO MID 90S EAST. OF
COURSE ANY CONVECTION AND OR BLOWOFF OF STORMS WILL LIMIT SOME
HEATING FROM TIME TO TIME DURING THE DAY.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 145 AM EDT SUNDAY...
GRIDDED LAMP GUIDANCE HAD CLOUDS LIFTING TO MVFR AROUND 16Z AT
ROA/LYH/DAN AND BCB BUT CONFIDENCE IS LOW THAT IMPROVEMENT WILL BE
THAT QUICK. THINK ALL LOCATIONS SHOULD FINALLY REACH VFR CIGS BY
MID AFTERNOON WITH LYH LIKELY BEING THE LAST AIRPORT TO SCATTER
OUT THE LOW CLOUDS.
ONCE CLOUDS BURN OFF...AN UPPER LEVEL TROUGH AND AFTERNOON
HEATING MAY GENERATE AN ISOLATED SHOWER OR THUNDERSTORM THIS
AFTERNOON BUT TOO ISOLATED TO INCLUDE MENTION IN THE TAFS.
FOG MAY REFORM ACROSS THE MOUNTAIN VALLEYS TONIGHT INTO MONDAY
MORNING. HAVE ADDED LIFR FOG IN THE GREENBRIER VALLEY FOR THE LWB
AIRPORT.
NW FLOW ALOFT LOOKS TO PERSIST MONDAY THRU THURSDAY...RESULTING
IN BOUTS OF SHRA/TSRA THRU THE PERIOD. OTHERWISE EXPECTING VFR
OUTSIDE OF ANY PERIODS OF THUNDERSTORMS...AND CONTINUED LATE NIGHT
FOG THROUGH MID OR LATE WEEK.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...KM
LONG TERM...WP
AVIATION...AMS/JH
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
437 AM EDT SUN JUL 22 2012
.SYNOPSIS...
A FRONTAL BOUNDARY FROM NORTH CAROLINA INTO TENNESSEE WILL
DISSIPATE TODAY. HIGH PRESSURE WILL STRETCH FROM THE CENTRAL
PLAINS TO THE SOUTHEAST COAST FROM TONIGHT INTO MONDAY. A COLD
FRONT WILL APPROACH THE AREA FROM THE NORTH BY WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 415 AM EDT SUNDAY...
RADAR SHOWED ISOLATED SHOWERS FROM SMYTH AND GRAYSON COUNTIES INTO
THE NORTHWEST NORTH CAROLINA MOUNTAINS. THEY REST OF THE
PRECIPITATION FROM EARLIER TONIGHT HAS EITHER DISSIPATED OR MOVD
SOUTHEAST OUT OF THE FORECAST AREA. VAD WIND PROFILES FROM AREA
RADARS SHOWED A NORTH TO NORTHEAST WIND IN THE LOWER 1-4KFT WITH
WEST WINDS ABOVE THIS LAYER. FRONT EXTENDING ACROSS NORTH CAROLINA
AND TENNESSEE WILL CONTINUE TO WEAKEN AND DISSIPATE TODAY WITH
THE WEDGE ERODING AND SURFACE WINDS BECOMING SOUTH TO SOUTHWEST
OVER THE FORECAST AREA BY MID AFTERNOON.
EXPECT LOW CLOUDS TO HOLD IN EAST OF THE BLUE RIDGE THIS MORNING.
EVEN IF COUNTIES IN THE NORTHEAST PART OF THE FORECAST AREA DO NOT
SCATTER OUT UNTIL LATER TODAY...EVEN JUST A COUPLE HOURS OF SUN
WILL BRING TEMPERATURES WELL INTO THE 80S. USED A NON DIURNAL
HOURLY TEMPERATURE FORECAST BASED ON THE GRIDDED LAMP GUIDANCE AND
EXPECTED CLOUD COVER.
FR PROBABILITY OF PRECIPITATION...MODELS HELD ON TO A LOW CHANCE
THIS MORNING. HRRR AND LOCAL WRF SHOWED SHOWERS AND THUNDERSTORMS
DEVELOPING THIS AFTERNOON SOUTH OF HWY 460. ADJUSTED TIMING AND
COVERAGE OF THE PRECIPITATION IN THE SOUTH THIS AFTERNOON.
ONCE STORMS DISSIPATE IN THE EVENING...LITTLE TO NO PRECIPITATION
EXPECTED OVERNIGHT. MAV GUIDANCE LOOKED REASONABLE FOR MINIMUM
TEMPERATURES.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 400 AM EDT SUNDAY...
HEIGHTS INCREASE INTO EARLY NEXT WEEK AS A SLICE OF THE UPPER RIDGE
RESPONSIBLE FOR THE HOT WEATHER ACROSS THE HEARTLAND STRETCHES
EASTWARD. H85 TEMPS WILL RISE TO AROUND +20C. CONSIDERING THE
MOVEMENT OF THE UPPER RIDGE AND ITS POSITION BY TUESDAY ...MOVING
JUST TO OUR SW WHICH WILL DELIVER A DOWNSLOPING NW COMPONENT...TEMPS
MAY VERIFY THE WARMEST GUIDANCE VALUES. MOS HAS BEEN TOO COOL WITH
TEMPS ACROSS THE MIDWEST...AND THIS MAY CONTINUE INTO THE OHIO
VALLEY AND MIDDLE ATLANTIC. GFS/NAM HAVING A HARD TIME PINPOINTING
WHICH DAY WOULD BE BEST FOR AN MCS TO ROLL THROUGH AND INSTEAD HAVE
SEVERAL WAVES OF PRECIP MOVING THROUGH MONDAY THROUGH WEDNESDAY. THIS
PROBABLY HAS LED TO SOME OF THE COOLER MAX TEMPS OFF THE MET. THE
BEST CHANCE FOR AN MCS TO APPROACH OUR REGION LOOKS TO BE LATER
TUESDAY AND TUESDAY NIGHT...AS CORFIDI VECTORS HAVE SUFFICIENT
MAGNITUDE AND DIRECTION TO LEAD SOMETHING TO SE WEST VA FROM THE NW.
ALTHOUGH IT MAY STILL OCCUR...WIDESPREAD STORMS AND HIGH QPF EARLY
TUESDAY LOOKS OVERDONE. NOT ENOUGH CONFIDENCE TO GO LIKELY BUT WILL
KEEP THE HIGHEST POPS IN THE TUESDAY PM AND TUESDAY NIGHT
TIME FRAME...WITH MORE PULSE TYPE STORMS ON MONDAY AND SMALLER POPS.
COLD FRONT DRAPED WEST TO EAST THROUGH THE GREAT LAKES ON TUESDAY
SINKS TO SE WEST VA AND NEAR NW NC INTO WEDNESDAY. THEREFORE THOSE
SPOTS HAVE THE BEST CHANCE OF STORMS CONTINUING INTO MIDWEEK.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 1222 PM EDT SATURDAY...
LOOKS LIKE WE WILL BE STUCK IN A HUMID SOMEWHAT STORMY BUT TYPICAL
LATE JULY PATTERN WITH THE RIDGE STAYING RIGHT ON THE SWRN DOORSTEP
OF OUR REGION...WITH THE BLACKSBURG FORECAST AREA REMAINING ON THE
SRN FRINGE OF THE TROUGH OVER THE NORTHEAST.
WILL BE GOING WITH DAILY THREAT OF SHRA/TSRA BUT WILL SEE ENHANCED
PROBABILITIES AS A SERIES OF SHORTWAVES GRAZE BY...BUT TIMING AT
THIS POINT IS UP IN THE AIR...WITH FRONTAL BOUNDARY SWINGING TOWARD
US IN THE WED-THU TIME FRAME THEN LIFTING NORTH AGAIN BY THE WEEKEND.
LOWS AT NIGHT WILL STAY IN THE 60S IN THE MTNS WITH LOWER 70S EAST
WITH HIGHS IN THE MID-UPPER 80S MTNS TO LOWER TO MID 90S EAST. OF
COURSE ANY CONVECTION AND OR BLOWOFF OF STORMS WILL LIMIT SOME
HEATING FROM TIME TO TIME DURING THE DAY.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
AS OF 145 AM EDT SUNDAY...
GRIDDED LAMP GUIDANCE BRINGS IFR CEILINGS INTO ROA/BLF AND BCB BY
09Z. EAST TO NORTHEAST DIRECTION OF THE SURFACE AND LOW LEVEL
WINDS WILL PRODUCE SOME FOG AND DRIZZLE...ESPECIALLY ON THE EAST
SLOPES OF THE BLUE RIDGE OVERNIGHT. LAMP GUIDANCE HAD CLOUDS
LIFTING TO MVFR AROUND 14-15Z BUT CONFIDENCE IS LOW THAT
IMPROVEMENT WILL BE THAT QUICK. THINK ALL LOCATIONS SHOULD
FINALLY REACH VFR CIGS BY MID AFTERNOON WITH LYH LIKELY BEING THE
LAST AIRPORT TO SCATTER OUT THE LOW CLOUDS.
ONCE CLOUDS BURN OFF...AN UPPER LEVEL TROUGH AND AFTERNOON
HEATING MAY GENERATE AN ISOLATED SHOWER OR THUNDERSTORM THIS
AFTERNOON BUT TOO ISOLATED TO INCLUDE MENTION IN THE TAFS.
FOG MAY REFORM ACROSS THE MOUNTAIN VALLEYS TONIGHT INTO MONDAY
MORNING.
NW FLOW ALOFT LOOKS TO PERSIST MONDAY THRU THURSDAY...RESULTING
IN BOUTS OF SHRA/TSRA THRU THE PERIOD. OTHERWISE EXPECTING VFR
OUTSIDE OF ANY PERIODS OF THUNDERSTORMS...AND CONTINUED LATE NIGHT
FOG THROUGH MID OR LATE WEEK.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...KM
LONG TERM...WP
AVIATION...AMS/JH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
311 PM CDT SUN JUL 22 2012
.SHORT TERM...TONIGHT THROUGH WEDNESDAY
311 PM CDT SUN JUL 22 2012
THE MAIN FOCUS GOING THROUGH MID WEEK IS WITH THE PRECIPITATION
CHANCES AND HOW WARM IT WILL GET TOMORROW.
LITTLE TO NO CHANGE TO THE UPPER LEVEL PATTERN AS A LARGE...YET
FLAT RIDGE OF HIGH PRESSURE REMAINS CENTERED ON THE CENTRAL
PLAINS. THE FOCUS FOR ANY PRECIPITATION CHANCES HAS BEEN WITH ANY
MID LEVEL SHORT WAVE TROUGHS THAT HAVE DROPPED DOWN FROM THE
NORTHWEST FROM THE DAKOTAS. THIS MORNINGS SHORT WAVE HAS
PROPAGATED OFF TO THE EAST WITH A CLOSED MID LEVEL LOW TRACKING
EAST ACROSS SOUTH CENTRAL CANADA. THIS MORE POTENT MID LEVEL LOW
HAS LED TO STRONGER SOUTHERLY LOW LEVEL FLOW WITH ONE SURFACE
LOW/LEFT OVER MCV OVER SOUTHERN MINNESOTA AND A DEEPER LOW NORTH
OF WINNIPEG.
THE INITIAL FOCUS FOR THE REST OF THIS AFTERNOON AND EVENING IS
WITH THE WARM FRONT THAT EXTENDS EAST OUT OF THE MCV LOW TOWARD
EAU CLAIRE AND HAS BEEN LIFTING NORTH THROUGH THE AFTERNOON. SKIES
HAVE CLEARED ACROSS MUCH OF NORTHERN IOWA WITH SCATTERED
CONVECTION/CLOUD COVER STILL OVERHEAD THROUGH MUCH OF SOUTHERN
MINNESOTA AND WESTERN WISCONSIN. WITH INVERTED V SOUNDINGS NOTED
FROM THE WARM SECTOR WHERE SURFACE TEMPERATURES QUICKLY JUMPED
INTO THE 90S...THE CONCERN IS THAT SOME SURFACE BASED STORMS WILL
BE IGNITED AS THE MCV MOVES IN AND BRINGS SOME STRONG WINDS ALONG
WITH IT. THIS AFTERNOON/S HRRR RUNS HAVE BEEN HITTING WESTERN
WISCONSIN HARDER WITH CONVECTION ALONG THE WARM FRONT WHICH
APPEARS TO BE OVERDONE. WHILE CONFIDENCE IS LOW WITH HOW THE REST
OF THIS AFTERNOON AND EVENING WILL PAN OUT...THERE APPEARS TO BE
ENOUGH OF A THREAT TO CARRY SOME CHANCES FOR PRECIPITATION INTO
THE EVENING.
BEYOND TONIGHT...THE MAIN COLD FRONT DROPS SOUTH TOMORROW AND
BECOMES STATIONARY IN NORTHERN IOWA BY TOMORROW NIGHT. THIS
FEATURE MAY BE ENOUGH OF A KICKER TO INITIATE CONVECTION ALONG IT
TOMORROW DESPITE HIGH LFC/S AND LACK OF UPPER LEVEL SUPPORT.
WITH INCREASING 850-500MB FRONTOGENESIS ALONG THIS FRONTAL
ZONE...ADDED SOME SMALL SHOWER/STORM CHANCES TOMORROW AFTERNOON
AND INCREASED THE EVENING CHANCES. SEVERE WEATHER DOES NOT LOOK
VERY LIKELY...BUT INVERTED V SOUNDINGS OUT AHEAD OF THE FRONT
COULD LEAD TO SOME GUSTY WINDS WITH SOME OF THE STORMS THAT DO
MANAGE TO DEVELOP.
WITH THE COLD FRONT BRINGING SOME CLOUD COVER ALONG WITH IT AND
DEEP AFTERNOON MIXING LEADING TO DRYING DEW POINTS...IT DOES NOT
APPEAR AS THOUGH HEAT INDICES WILL WARM UP MUCH BEYOND 100 DEGREES.
THE MISSISSIPPI AND WISCONSIN RIVER VALLEYS MAY BE THE EXCEPTION
WHERE TEMPERATURES WILL BE A FEW DEGREES HIGHER. AFTER COLLABORATION
WITH NEIGHBORING OFFICES...HAVE DECIDED TO NOT ISSUE A HEAT
ADVISORY FOR TOMORROW ACROSS NORTHEAST IOWA/SOUTHWEST WISCONSIN.
THE BAROCLINIC ZONE ALONG THE FRONT BECOMES MORE ACTIVE MONDAY
NIGHT THROUGH WEDNESDAY AS THE LOW LEVEL FRONTOGENESIS STAYS
STRONG AND THE LOW LEVEL MOISTURE TRANSPORT INCREASES. CONFIDENCE
IS PRETTY HIGH THAT SOME MORE SIGNIFICANT RAINS WILL COME AS THIS
PATTERN SETS UP...PARTICULARLY AT NIGHT WHEN THE LOW LEVEL JET
DEVELOPS AND NOSES UP INTO THE REGION. CAN NOT RULE OUT SOME
SEVERE WEATHER OVER THIS TIME FRAME AS WELL WITH UNSTABLE AIR
POOLING ALONG THE FRONT ALONG WITH DECENT DEEP LAYER
SHEAR...PARTICULARLY IF THE BOUNDARY HANGS UP ACROSS THE AREA IN
NORTHEAST IOWA AND NOT TO THE SOUTH AS FORECAST. THE BETTER
CHANCES FOR ORGANIZED CONVECTION MAY BE ON TUESDAY NIGHT INTO
WEDNESDAY AS A MID LEVEL SHORT WAVE TROUGH COMES THROUGH AND
BRINGS A LOW ALONG THE STATIONARY FRONT.
.LONG TERM...WEDNESDAY NIGHT THROUGH SATURDAY NIGHT
311 PM CDT SUN JUL 22 2012
THE STATIONARY FRONT WILL GET A KICK TO THE SOUTH IN THE WAKE OF
THE SURFACE LOW THAT COMES THROUGH ON WEDNESDAY THOUGH CHANCES FOR
SHOWERS AND THUNDERSTORMS WILL PERSIST INTO FRIDAY AS A CLOSED MID
LEVEL LOW DROPS SOUTHEAST FROM THE NORTHERN PLAINS INTO THE GREAT
LAKES. RIDGING THEN MOVES IN FROM THE WEST FRIDAY NIGHT INTO
SATURDAY AT THE SURFACE AND ALOFT AND SHOULD BRING DRIER
CONDITIONS ALONG WITH IT. TEMPERATURES LOOK SEASONAL IN THE LOW TO
MID 80S ACROSS THE REGION WITH 850MB TEMPERATURES DROPPING INTO
THE +15C AREA.
&&
.AVIATION...THROUGH 18Z MONDAY
1243 PM CDT SUN JUL 22 2012
CURRENTLY WATCHING A WEAKENING MID-LEVEL TROUGH WHICH CAUSED
OVERNIGHT/MORNING CONVECTION ROTATE EAST OF THE RIVER. AS A
RESULT...BULK OF SHRA/ISOLD TS ACTIVITY NOW EAST OF THE TAF SITES.
OTHERWISE...A SURFACE WARM FROM WAS LOCATED FROM NEAR THE TWIN
CITIES AND THEN SOUTHEAST APPROXIMATELY ALONG I-94. SOUTH WINDS
HAVE BEEN PICKING UP IN THE WARM SECTOR AT KRST/KLSE THE LAST
COUPLE OF HOURS WITH SOME GUSTINESS EXPECTED THROUGH THE AFTERNOON
TO AROUND 20-25KT AT KRST. KLSE EXPECTED TO STAY IN THE 10-15KT
RANGE. SKY COVER EXPECTED TO BE SCATTERED AC/ACCAS IN BROAD WARM
AIR ADVECTION. OVERNIGHT PERIOD LOOKS RELATIVELY QUIET WITH
SCATTERED AC/ACCAS CONTINUING AND WINDS SLACKENING. WINDS WILL
START VEERING TO THE WEST/NORTHWEST MONDAY MORNING IN THE 14-15Z
TIME FRAME AS A SURFACE COLD FRONT MOVES SOUTHEAST THROUGH THE
AREA. ONCE THE FRONT SLIPS JUST SOUTH OF THE AREA IT IS EXPECTED
TO STALL OUT ACROSS NORTHERN IA/IL. ANOTHER WEAK MID-LEVEL TROUGH
IS THEN EXPECTED TO INTERACT WITH THIS FRONTAL BOUNDARY BY MONDAY
AFTERNOON FOR A CHANCE OF SHRA/TS...WITH MOST OF THIS ACTIVITY
EXPECTED TO REMAIN SOUTH OF THE TAF SITES. OTHERWISE...APPEARS VFR
CONDITIONS WILL PREVAIL THROUGH MONDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
311 PM CDT SUN JUL 22 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...DAS
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
308 PM CDT SUN JUL 22 2012
.SHORT TERM...
.TONIGHT AND MONDAY...FORECAST CONFIDENCE IS MEDIUM.
WIDELY SCATTERED SHOWERS HAVE BEEN MOVING INTO AREAS WEST OF MADISON
ALL DAY...AND HAVE DIMINISHED WITH DRY AIR IN LOW LEVELS OF THE
ATMOSPHERE. THESE SHOWERS DRIVEN BY LOW LEVEL JET NOSE/WARM AIR
ADVECTION AND PASSING VORTICITY MAXIMUM. ANOTHER VORTICITY MAXIMUM
IN SOUTHWEST MINNESOTA SHOULD SHIFT EAST ACROSS THE AREA THROUGH
THIS EVENING. IN ADDITION...LOW LEVEL JET NOSE SHIFTS EAST ACROSS
THE AREA THIS EVENING...WITH FOCUSED WARM AIR ADVECTION.
AREA FORECAST SOUNDINGS FROM NAM SHOWING ELEVATED CAPES ONLY UP TO
500 J/KG...WITH GOOD DEEP LAYER SHEAR. MEAN LAYER CAPE MUCH HIGHER
ON RAP ANALYSIS...BUT DEWPOINTS SEEM OVERDONE BY SEVERAL DEGREES.
LEVEL OF FREE CONVECTION NEAR 700MB AS WELL...WITH A BIT OF A CAP TO
WORK THROUGH. INVERTED V TYPE STRUCTURE TO SOUNDINGS DO INDICATE
DOWNBURST WIND POTENTIAL IF ANY DECENT CELLS DEVELOP. MESOSCALE
MODELS DIFFER A FAIR AMOUNT WITH TRENDS THROUGH THE NIGHT.
GIVEN SOME UNCERTAINTY WITH EXACT EVOLUTION OF POSSIBLE
CONVECTION...WITH GO WITH CHANCE POPS FOR THUNDER THROUGH THE
EVENING...LINGERING IN THE SOUTHEAST AFTER 06Z MONDAY.
OTHERWISE...MID LEVEL CLOUDS SHOULD LINGER...WITH MILD LOWS IN THE
70S ACROSS MOST OF THE AREA.
WEST SOUTHWEST WINDS AHEAD OF COLD FRONT PULL HOT AIRMASS INTO THE
AREA. 925MB TEMPERATURES FROM NAM SUGGEST HIGHS OF AROUND 100 OR A
BIT HIGHER...BUT SHOULD HAVE AT LEAST SOME MID LEVEL CLOUDS IN THE
AREA WITH PASSING VORTICITY MAXIMUM. WITH UNCERTAINTY WITH AMOUNT OF
CLOUDS IN THE AREA...OPTED TO GO MID TO UPPER 90S FOR HIGHS...WHICH
KEEPS HEAT INDEX VALUES JUST UNDER 100. THUS...WILL HOLD OFF ON A
HEAT ADVISORY FOR NOW.
ALSO...WEAK COLD FRONT DROPPING SOUTHEAST INTO THE AREA DURING THE
AFTERNOON MAY HELP GENERATE SHOWERS AND A FEW STORMS. SOMEWHAT
BETTER MEAN LAYER CAPES WITH GOOD DEEP LAYER SHEAR EXPECTED...BUT
WILL HAVE TO AGAIN REACH NEAR 700MB LEVEL OF FREE CONVECTION. SLIGHT
CHANCES FOR THUNDER SEEM REASONABLE FOR NOW.
.MONDAY NIGHT AND TUESDAY...FORECAST CONFIDENCE MEDIUM TO HIGH.
THE NEAR 100 KNOT JET MAX NEAR LAKE SUPERIOR MONDAY EVENING WILL
WEAKEN A BIT AS IT REACHES LAKE HURON EARLY TUESDAY MORNING...WITH
WISCONSIN IN A NORTHWEST MID/UPPER FLOW. THERE IS SOME 250 MB UPPER
DIVERGENCE MONDAY NIGHT ACROSS SOUTHERN WISCONSIN...WITH SOME
CONVECTIVE FEEDBACK ON THE NAM GIVING SEVERAL BULLS EYES OF MORE
MODERATE DIVERGENCE.
THE SURFACE BOUNDARY IS PUSHED SOUTH ACROSS EASTERN IOWA AND
FAR NORTHERN ILLINOIS TUESDAY NIGHT...THEN ACROSS CENTRAL ILLINOIS
TO SOUTHERN INDIANA LATE MONDAY EVENING. THE 925/850 MB THERMAL
RIDGE IS PUSHED TO THE SOUTH OF WISCONSIN ROUGHLY PARALLELING THE
SURFACE BOUNDARY. THE 700 MB RELATIVE HUMIDITY IS FAIRLY HIGH
MONDAY NIGHT WITH MODERATE 700 MB UPWARD MOTION AROUND 11 MICROBARS/SEC
ALONG AND JUST NORTH OF THE BOUNDARY...WHILE THE 700 MB MOISTURE
CONVERGENCE IS HIGHEST ACROSS SOUTHERN WISCONSIN.
THE FORECAST SOUNDINGS ARE FAIRLY MOIST WITH PRECIPITABLE WATER
VALUES AROUND 2 INCHES ACROSS MUCH OF THE FORECAST AREA. SOME
ELEVATED CAPE OF AROUND 1000 J/KG ALSO EXISTS DURING THE
EVENING...BUT THIS IS IF LIFTED FROM JUST ABOVE THE DEVELOPING
NOCTURNAL INVERSION. GIVEN ALL THIS WILL CONTINUE THE CHANCE OF
THUNDERSTORMS.
.TUESDAY NIGHT AND WEDNESDAY...FORECAST CONFIDENCE MEDIUM TO HIGH.
THE MID/UPPER FLOW BECOMES MORE WEST WEDNESDAY AS THE SOUTHWEST
CANADIAN MID/UPPER LOW MOVES INTO SOUTHERN SASKATCHEWAN...THEN
TOWARDS LAKE WINNIPEG. THERE IS MODERATE UPPER DIVERGENCE ACROSS
MUCH OF THE FORECAST AREA TUESDAY NIGHT...THEN EXITING TO THE EAST
BY NOON WEDNESDAY. MODERATE 700 MB MOISTURE CONVERGENCE OF UP TO
20 G/KG/12 HOUR EXTENDS ACROSS THE FORECAST AREA TUESDAY NIGHT
INTO WEDNESDAY. THE 850 MB FLOW BECOMES SOUTHWEST MAINLY JUST TO
OUR SOUTH WITH AROUND 10 G/KG/12 HOUR VALUES OF 850 MB MOISTURE
CONVERGENCE. 800 AND 700 MB LI`S ARE AROUND -3 TUESDAY NIGHT AND
WEDNESDAY WITH ELEVATED CAPE AROUND 800 J/KG LIFTED FROM THE
MOISTURE LAYER AT 8 THSD FT. PRECIPITABLE VALUES REMAIN AROUND 2
INCHES OVER MUCH OF THIS TIME FRAME...WITH MOST MODELS INDICATING
PRECIPITATION WITH MODERATE AMOUNTS AROUND 0.50 INCH.
THE NORTHERN PORTION OF THE 850 MB THERMAL RIDGE DOES PUSH INTO
EASTERN IOWA AND NORTHERN ILLINOIS WITH THE SOUTHWEST PORTIONS OF
THE FORECAST AREA ON THE NOSE OF THE THERMAL RIDGE WITH TEMPERATURES
NEAR 24 CELSIUS.
THE 12Z NAM AND 06Z DGEX KEEPS THE SURFACE FRONT ACROSS IOWA AND
NORTHERN ILLINOIS. HOWEVER THE 12Z GFS AND 00Z ECMWF DOES PUSH A
WARM FRONT INTO SOUTHWEST PORTIONS OF THE FORECAST AREA FROM NEAR
MADISON TO JANESVILLE. THICKNESS VALUES ARE NEAR 582 DECAMETERS ON
MOST OF THE MODELS NEAR THE ILLINOIS BORDER.
FAIRLY DECENT PRECIPITATION CHANCES DURING THIS TIME FRAME.
THE LOCAL CWASP SEVERE WEATHER INDEX HAS VALUES NEAR 60 PERCENT
ON THE GFS WEDNESDAY AFTERNOON WHILE THE NAM HAS IT CLOSER TO THE
LOW OVER NORTHERN MINNESOTA...WHICH SEEMS TO BE MORE REASONABLE.
.LONG TERM...
.WEDNESDAY NIGHT AND THURSDAY...FORECAST CONFIDENCE MEDIUM TO HIGH.
BY THURSDAY THE UPPER LOW/TROUGH AXIS REACHES FAR NORTHERN
MINNESOTA.
THE SURFACE LOW PATTERN HAS A DOUBLE LOW STRUCTURE WITH ONE LOW
NEAR THE BOUNDARY AND ANOTHER CLOSER TO THE MID LEVEL TROUGH.
FAIRLY DECENT PRECIPITATION CHANCES CONTINUE WEDNESDAY NIGHT INTO
THURSDAY.
.FRIDAY AND SATURDAY...FORECAST CONFIDENCE MEDIUM TO HIGH.
THE ECMWF AND GFS TAKES THE UPPER TROUGH ACROSS THE GREAT LAKES
FRIDAY AND OFF TO THE NORTHEAST U.S. AND SOUTHEAST CANADA
SATURDAY.
BOTH THE GFS AND ECMWF BRINGS SOME INSTABILITY SHOWERS FRIDAY
BEFORE HIGH PRESSURE EXTENDS ACROSS THE UPPER MISSISSIPPI VALLEY
AND WESTERN GREAT LAKES SATURDAY.
.SUNDAY...FORECAST CONFIDENCE MEDIUM.
A MORE ZONAL FLOW RETURNS ACROSS THE NORTHERN U.S. ON SUNDAY. THE
12Z GFS AND 06Z DGEX ARE DRY...BUT THE 00Z/12Z ECMWF HAS SOME
PRECIPITATION IN THE RETURN WARM AIR ADVECTION REGION GETTING
INTO PORTIONS OF SOUTHERN WISCONSIN. WILL LEAN TOWARDS A CONSENSUS
FORECAST.
&&
.AVIATION/00Z TAFS/...
VFR CONDITIONS EXPECTED THROUGH MONDAY ACROSS TAF SITES. BROKEN
MIDDLE TO HIGH CLOUDS SHOULD CONTINUE TO SPREAD ACROSS TAF SITES
LATE THIS AFTERNOON...AND LINGER TONIGHT. ANY SHOWERS AND
THUNDERSTORMS THAT TRY TO FORM AND MOVE THROUGH SOUTHERN WISCONSIN
DURING THIS TIME WILL HAVE TO BATTLE DRIER LOW LEVEL AIRMASS OVER
THE AREA. THERE SHOULD STILL BE ENOUGH LIFT WITH LOW LEVEL JET
STREAM TO BRING CHANCES FOR SHOWERS AND THUNDERSTORMS AROUND TAF
SITES. CONFIDENCE IS LOW IN EXACT TIMING...SO USED VICINITY WORDING
IN TAFS FOR NOW.
POSSIBILITY FOR LOW LEVEL WIND SHEAR BETWEEN 04Z AND 09Z WITH 40
KNOT PLUS WINDS AT 2000 FEET ABOVE GROUND LEVEL. CONFIDENCE LOW IN
THE MAGNITUDE OF THESE WINDS...SO LEFT MENTION OUT OF TAFS FOR NOW.
LIGHT TO MODERATE SOUTH SOUTHWEST WINDS BY 00Z MONDAY SHOULD BECOME
SOUTHWEST LATER TONIGHT...AND WESTERLY ON MONDAY. HOT AIRMASS MONDAY
EXPECTED. COLD FRONT PASSING SOUTHEAST THROUGH THE AREA DURING THE
AFTERNOON WILL BRING SLIGHT CHANCES OF SHOWERS AND
THUNDERSTORMS...BUT LEFT MENTION OUT OF TAFS FOR NOW DUE TO LOW
CONFIDENCE IN TIMING AND COVERAGE. SCATTERED TO BROKEN MID LEVEL
CLOUDS SHOULD CONTINUE INTO MONDAY AS WELL.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TONIGHT/MONDAY AND AVIATION/MARINE...WOOD
MONDAY NIGHT THROUGH SUNDAY...HENTZ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1243 PM CDT SUN JUL 22 2012
.SHORT TERM...THROUGH TUESDAY
227 AM CDT SUN JUL 22 2012
MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES THROUGH THE PERIOD.
SURFACE ANALYSIS THIS MORNING SHOWED A WEAK AREA OF LOW
PRESSURE OVER SOUTH DAKOTA WITH A WARM FRONT EXTENDING EAST ACROSS
SOUTHERN MINNESOTA INTO CENTRAL WISCONSIN. LOCAL AND REGIONAL
RADARS SHOWING A COMPLEX OF SHOWERS AND THUNDERSTORMS ALONG AND
SOUTH OF THE BOUNDARY OVER SOUTHERN MINNESOTA.
WATER VAPOR IMAGERY LOOP SHOWS A WEAK SHORT WAVE TROUGH OVER
WESTERN MINNESOTA HELPED TO SPARK THE CONVECTION THIS MORNING. THE
22.03Z RAP BRINGS THIS SHORT WAVE TROUGH ACROSS THE AREA ON ITS
WAY TO THE SOUTHERN TIP OF LAKE MICHIGAN BY LATE MORNING. THE WAVE
IS PRODUCING AROUND 4 PVU/S OF VORTICITY ADVECTION IN THE 500-300
MB LAYER AND IS EXPECTED TO CONTINUE DOING SO AS IT MOVES
OVERHEAD. THE LOW LEVEL MOISTURE TRANSPORT INTO THE ACTIVITY IS
EXPECTED TO GRADUALLY TURN TO THE SOUTHWEST THE FARTHER EAST THE
ACTIVITY GETS...BUT SHOULD CONTINUE TO FEED INTO IT UNTIL AFTER
SUNRISE. WILL CONTINUE TO MONITOR RADAR TRENDS BUT THINKING THERE
SHOULD BE DECENT COVERAGE OF SHOWERS FOR AREAS WEST OF THE
MISSISSIPPI RIVER FOR THE FIRST HALF OF THE MORNING. COVERAGE
SHOULD THEN START TO DIMINISH AS THE MOISTURE FEED STARTS TO
WEAKEN WITH ONLY SOME WIDELY SCATTERED ACTIVITY LEFT OVER FOR THE
AFTERNOON.
ONCE THE FRONT GOES THROUGH TODAY...IT WILL BECOME STATIONARY JUST
SOUTH OF THE AREA AND BECOME THE FOCUS FOR THE REMAINDER OF THE
PERIOD. THE 22.00Z NAM...AND TO A LESSER DEGREE...THE 21.12Z ECMWF
SHOW THE FRONTOGENESIS GRADUALLY INCREASING AND BECOMING DEEPER
ALONG THE FRONT STARTING MONDAY. BY LATE MONDAY NIGHT INTO TUESDAY
MORNING...THE FRONTOGENESIS IS EXPECTED TO BE MODERATE IN
STRENGTH IN THE 1000-850 MB LAYER AND WEAK IN THE 850-500 MB
LAYER. THE NEXT SURFACE LOW WILL BE TAKING SHAPE OVER NEBRASKA OR
SOUTH DAKOTA ALONG THE WESTERN PART OF THE FRONT. AS THIS
CONTINUES TO DEVELOP...THE LOW LEVEL WARM AIR ADVECTION OVER THE
FRONT WILL BE INCREASING WITH THE ECMWF SHOWING AROUND 2 UBAR/S
OF UP GLIDE ON THE 315K ISENTROPIC SURFACE OVER THE FRONT. THESE
HAVE BEEN CONSISTENT SIGNALS SO HAVE RAISED THE RAIN CHANCES UP TO
50 PERCENT FOR A GOOD SHARE OF THE AREA NORTH OF THE FRONT. THE
MOISTURE TRANSPORT INTO THE FRONT DOES NOT LOOK TO BE VERY STRONG
WITH BOTH THE NAM AND ECMWF SUGGESTING IT WILL BE MORE PARALLEL TO
THE FRONT INSTEAD OF INTO IT. THE FORCING THEN STARTS TO WEAKEN
BUT DOES NOT TOTALLY DISSIPATE TUESDAY AFTERNOON SO MAINTAINED A
30 PERCENT CHANCE FOR MUCH OF THE AREA.
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
227 AM CDT SUN JUL 22 2012
BOTH THE 21.12Z AND 22.00Z RUNS OF THE ECMWF HAVE SUGGESTED A
PATTERN SHIFT WILL BE TAKING PLACE THROUGH THE EXTENDED. THE MEAN
UPPER LEVEL RIDGE IS EXPECTED TO GET FLATTENED AND PUSHED TO THE
SOUTHEAST AS AN UPPER LEVEL LOW MOVES ALONG THE CANADIAN BORDER.
AS THIS SYSTEM MOVES BY LATE IN THE PERIOD...THE RIDGE THEN DOES
NOT BUILD BACK OVER THE ROCKIES NEARLY AS STRONG AS ANOTHER STORM
SYSTEM LOOKS TO BE MOVING ONSHORE WITH MEAN TROUGHING DEVELOPING
ALONG THE WEST COAST KEEPING THE FLOW OVER THE UPPER MIDWEST MORE
OF A ZONAL TO WEAK NORTHWEST PATTERN. AS THE UPPER LEVEL LOW
APPROACHES...THE SURFACE LOW WILL TRACK EAST ALONG THE FRONTAL
BOUNDARY WITH INCREASING FRONTOGENESIS AND ISENTROPIC UP GLIDE.
THIS FORCING WILL COMBINE WITH THE LIFT AHEAD OF THE UPPER LEVEL
LOW AND PROVIDE GOOD FORCING FOR RAIN OVER THE AREA TUESDAY NIGHT
INTO WEDNESDAY NIGHT. THE RAIN CHANCES WILL CONTINUE THURSDAY INTO
FRIDAY BUT WILL BE ON THE DECREASE AS THE SYSTEM MOVES SLOWLY PAST
THE AREA.
&&
.AVIATION...THROUGH 18Z MONDAY
1243 PM CDT SUN JUL 22 2012
CURRENTLY WATCHING A WEAKENING MID-LEVEL TROUGH WHICH CAUSED
OVERNIGHT/MORNING CONVECTION ROTATE EAST OF THE RIVER. AS A
RESULT...BULK OF SHRA/ISOLD TS ACTIVITY NOW EAST OF THE TAF SITES.
OTHERWISE...A SURFACE WARM FROM WAS LOCATED FROM NEAR THE TWIN
CITIES AND THEN SOUTHEAST APPROXIMATELY ALONG I-94. SOUTH WINDS
HAVE BEEN PICKING UP IN THE WARM SECTOR AT KRST/KLSE THE LAST
COUPLE OF HOURS WITH SOME GUSTINESS EXPECTED THROUGH THE AFTERNOON
TO AROUND 20-25KT AT KRST. KLSE EXPECTED TO STAY IN THE 10-15KT
RANGE. SKY COVER EXPECTED TO BE SCATTERED AC/ACCAS IN BROAD WARM
AIR ADVECTION. OVERNIGHT PERIOD LOOKS RELATIVELY QUIET WITH
SCATTERED AC/ACCAS CONTINUING AND WINDS SLACKENING. WINDS WILL
START VEERING TO THE WEST/NORTHWEST MONDAY MORNING IN THE 14-15Z
TIME FRAME AS A SURFACE COLD FRONT MOVES SOUTHEAST THROUGH THE
AREA. ONCE THE FRONT SLIPS JUST SOUTH OF THE AREA IT IS EXPECTED
TO STALL OUT ACROSS NORTHERN IA/IL. ANOTHER WEAK MID-LEVEL TROUGH
IS THEN EXPECTED TO INTERACT WITH THIS FRONTAL BOUNDARY BY MONDAY
AFTERNOON FOR A CHANCE OF SHRA/TS...WITH MOST OF THIS ACTIVITY
EXPECTED TO REMAIN SOUTH OF THE TAF SITES. OTHERWISE...APPEARS VFR
CONDITIONS WILL PREVAIL THROUGH MONDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
227 AM CDT SUN JUL 22 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
556 AM CDT SUN JUL 22 2012
.SHORT TERM...THROUGH TUESDAY
227 AM CDT SUN JUL 22 2012
MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES THROUGH THE PERIOD.
SURFACE ANALYSIS THIS MORNING SHOWED A WEAK AREA OF LOW
PRESSURE OVER SOUTH DAKOTA WITH A WARM FRONT EXTENDING EAST ACROSS
SOUTHERN MINNESOTA INTO CENTRAL WISCONSIN. LOCAL AND REGIONAL
RADARS SHOWING A COMPLEX OF SHOWERS AND THUNDERSTORMS ALONG AND
SOUTH OF THE BOUNDARY OVER SOUTHERN MINNESOTA.
WATER VAPOR IMAGERY LOOP SHOWS A WEAK SHORT WAVE TROUGH OVER
WESTERN MINNESOTA HELPED TO SPARK THE CONVECTION THIS MORNING. THE
22.03Z RAP BRINGS THIS SHORT WAVE TROUGH ACROSS THE AREA ON ITS
WAY TO THE SOUTHERN TIP OF LAKE MICHIGAN BY LATE MORNING. THE WAVE
IS PRODUCING AROUND 4 PVU/S OF VORTICITY ADVECTION IN THE 500-300
MB LAYER AND IS EXPECTED TO CONTINUE DOING SO AS IT MOVES
OVERHEAD. THE LOW LEVEL MOISTURE TRANSPORT INTO THE ACTIVITY IS
EXPECTED TO GRADUALLY TURN TO THE SOUTHWEST THE FARTHER EAST THE
ACTIVITY GETS...BUT SHOULD CONTINUE TO FEED INTO IT UNTIL AFTER
SUNRISE. WILL CONTINUE TO MONITOR RADAR TRENDS BUT THINKING THERE
SHOULD BE DECENT COVERAGE OF SHOWERS FOR AREAS WEST OF THE
MISSISSIPPI RIVER FOR THE FIRST HALF OF THE MORNING. COVERAGE
SHOULD THEN START TO DIMINISH AS THE MOISTURE FEED STARTS TO
WEAKEN WITH ONLY SOME WIDELY SCATTERED ACTIVITY LEFT OVER FOR THE
AFTERNOON.
ONCE THE FRONT GOES THROUGH TODAY...IT WILL BECOME STATIONARY JUST
SOUTH OF THE AREA AND BECOME THE FOCUS FOR THE REMAINDER OF THE
PERIOD. THE 22.00Z NAM...AND TO A LESSER DEGREE...THE 21.12Z ECMWF
SHOW THE FRONTOGENESIS GRADUALLY INCREASING AND BECOMING DEEPER
ALONG THE FRONT STARTING MONDAY. BY LATE MONDAY NIGHT INTO TUESDAY
MORNING...THE FRONTOGENESIS IS EXPECTED TO BE MODERATE IN
STRENGTH IN THE 1000-850 MB LAYER AND WEAK IN THE 850-500 MB
LAYER. THE NEXT SURFACE LOW WILL BE TAKING SHAPE OVER NEBRASKA OR
SOUTH DAKOTA ALONG THE WESTERN PART OF THE FRONT. AS THIS
CONTINUES TO DEVELOP...THE LOW LEVEL WARM AIR ADVECTION OVER THE
FRONT WILL BE INCREASING WITH THE ECMWF SHOWING AROUND 2 UBAR/S
OF UP GLIDE ON THE 315K ISENTROPIC SURFACE OVER THE FRONT. THESE
HAVE BEEN CONSISTENT SIGNALS SO HAVE RAISED THE RAIN CHANCES UP TO
50 PERCENT FOR A GOOD SHARE OF THE AREA NORTH OF THE FRONT. THE
MOISTURE TRANSPORT INTO THE FRONT DOES NOT LOOK TO BE VERY STRONG
WITH BOTH THE NAM AND ECMWF SUGGESTING IT WILL BE MORE PARALLEL TO
THE FRONT INSTEAD OF INTO IT. THE FORCING THEN STARTS TO WEAKEN
BUT DOES NOT TOTALLY DISSIPATE TUESDAY AFTERNOON SO MAINTAINED A
30 PERCENT CHANCE FOR MUCH OF THE AREA.
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
227 AM CDT SUN JUL 22 2012
BOTH THE 21.12Z AND 22.00Z RUNS OF THE ECMWF HAVE SUGGESTED A
PATTERN SHIFT WILL BE TAKING PLACE THROUGH THE EXTENDED. THE MEAN
UPPER LEVEL RIDGE IS EXPECTED TO GET FLATTENED AND PUSHED TO THE
SOUTHEAST AS AN UPPER LEVEL LOW MOVES ALONG THE CANADIAN BORDER.
AS THIS SYSTEM MOVES BY LATE IN THE PERIOD...THE RIDGE THEN DOES
NOT BUILD BACK OVER THE ROCKIES NEARLY AS STRONG AS ANOTHER STORM
SYSTEM LOOKS TO BE MOVING ONSHORE WITH MEAN TROUGHING DEVELOPING
ALONG THE WEST COAST KEEPING THE FLOW OVER THE UPPER MIDWEST MORE
OF A ZONAL TO WEAK NORTHWEST PATTERN. AS THE UPPER LEVEL LOW
APPROACHES...THE SURFACE LOW WILL TRACK EAST ALONG THE FRONTAL
BOUNDARY WITH INCREASING FRONTOGENESIS AND ISENTROPIC UP GLIDE.
THIS FORCING WILL COMBINE WITH THE LIFT AHEAD OF THE UPPER LEVEL
LOW AND PROVIDE GOOD FORCING FOR RAIN OVER THE AREA TUESDAY NIGHT
INTO WEDNESDAY NIGHT. THE RAIN CHANCES WILL CONTINUE THURSDAY INTO
FRIDAY BUT WILL BE ON THE DECREASE AS THE SYSTEM MOVES SLOWLY PAST
THE AREA.
&&
.AVIATION...TODAY AND TONIGHT
556 AM CDT SUN JUL 22 2012
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL PERSIST ACROSS THE
AREA THROUGH THE MID MORNING HOURS. A FEW SHOWERS AND PERHAPS AN
ISOLATED THUNDERSTORM COULD IMPACT THE TAF SITES THIS MORNING. WILL
BE INCLUDED -SHRA AND VCTS AT BOTH TAF SITES THROUGH 14Z AT KRST
AND THROUGH 15Z AT KLSE TO ACCOUNT FOR THIS ACTIVITY. IF ANY
THUNDERSTORMS MOVE OVER THE TAF SITES...A BRIEF PERIOD OF MVFR
CONDITIONS WOULD OCCUR WITH CEILINGS LOWERING TO AROUND 2000 FT.
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO TAPER OFF LATER THIS
MORNING AS A WARM FRONT LIFTS TO THE NORTH OF THE TAF SITES AND
DRIER AIR ALOFT MOVES IN FROM THE SOUTHWEST. PLAN ON SOUTHWEST
WINDS INCREASING INTO THE 10 TO 15 KTS RANGE. FORECAST SOUNDINGS
ARE SUGGESTING WINDS COULD INCREASE INTO THE 15 TO 20 KT RANGE
WITH GUSTS AROUND 30 KTS POSSIBLE. THE MIXING SEEMS TOO AGGRESSIVE
IN THESE SOUNDINGS WITH SOME CLOUD COVER EXPECTED TO BE IN PLACE
THROUGH MUCH OF THE DAY. WILL HAVE TO MONITOR CLOUD TRENDS AND
MIXING CLOSELY LATE THIS MORNING INTO EARLY THIS AFTERNOON. THERE
IS A SLIGHT CHANCE OF A HIGH BASED SHOWER OR THUNDERSTORMS THIS
AFTERNOON. IF ANY STORMS WOULD DEVELOP...THEY WOULD BE CAPABLE OF
PRODUCING GUSTY WINDS. THINKING THE DRIER AIR MOVING IN SHOULD
KEEP STORMS FROM FORMING THIS AFTERNOON AT THE TAF SITES SO HAVE
NOT INCLUDED ANY SHOWER OR STORM MENTION IN THE THE TAFS AT THIS
TIME. A STRONG INVERSION IS EXPECTED ACROSS THE REGION OVERNIGHT
TONIGHT BRINGING THE POTENTIAL FOR LOW LEVEL WIND SHEAR. SURFACE
WINDS WILL DROP OFF THIS EVENING AS SURFACE HEATING DECREASES. A
MODEST LOW LEVEL JET LOOKS TO SET UP MAINLY AT KLSE TONIGHT WITH
WINDS JUST ABOVE THE SURFACE INCREASING TO AROUND 40 KTS. WILL
HAVE TO CLOSELY MONITOR SURFACE WINDS TONIGHT AND HOW MUCH
DECOUPLING OCCURS. OTHERWISE...PLAN ON VFR CONDITIONS DURING THE
OVERNIGHT HOURS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
227 AM CDT SUN JUL 22 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...WETENKAMP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
227 AM CDT SUN JUL 22 2012
.SHORT TERM...THROUGH TUESDAY
227 AM CDT SUN JUL 22 2012
MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES THROUGH THE PERIOD.
SURFACE ANALYSIS THIS MORNING SHOWED A WEAK AREA OF LOW
PRESSURE OVER SOUTH DAKOTA WITH A WARM FRONT EXTENDING EAST ACROSS
SOUTHERN MINNESOTA INTO CENTRAL WISCONSIN. LOCAL AND REGIONAL
RADARS SHOWING A COMPLEX OF SHOWERS AND THUNDERSTORMS ALONG AND
SOUTH OF THE BOUNDARY OVER SOUTHERN MINNESOTA.
WATER VAPOR IMAGERY LOOP SHOWS A WEAK SHORT WAVE TROUGH OVER
WESTERN MINNESOTA HELPED TO SPARK THE CONVECTION THIS MORNING. THE
22.03Z RAP BRINGS THIS SHORT WAVE TROUGH ACROSS THE AREA ON ITS
WAY TO THE SOUTHERN TIP OF LAKE MICHIGAN BY LATE MORNING. THE WAVE
IS PRODUCING AROUND 4 PVU/S OF VORTICITY ADVECTION IN THE 500-300
MB LAYER AND IS EXPECTED TO CONTINUE DOING SO AS IT MOVES
OVERHEAD. THE LOW LEVEL MOISTURE TRANSPORT INTO THE ACTIVITY IS
EXPECTED TO GRADUALLY TURN TO THE SOUTHWEST THE FARTHER EAST THE
ACTIVITY GETS...BUT SHOULD CONTINUE TO FEED INTO IT UNTIL AFTER
SUNRISE. WILL CONTINUE TO MONITOR RADAR TRENDS BUT THINKING THERE
SHOULD BE DECENT COVERAGE OF SHOWERS FOR AREAS WEST OF THE
MISSISSIPPI RIVER FOR THE FIRST HALF OF THE MORNING. COVERAGE
SHOULD THEN START TO DIMINISH AS THE MOISTURE FEED STARTS TO
WEAKEN WITH ONLY SOME WIDELY SCATTERED ACTIVITY LEFT OVER FOR THE
AFTERNOON.
ONCE THE FRONT GOES THROUGH TODAY...IT WILL BECOME STATIONARY JUST
SOUTH OF THE AREA AND BECOME THE FOCUS FOR THE REMAINDER OF THE
PERIOD. THE 22.00Z NAM...AND TO A LESSER DEGREE...THE 21.12Z ECMWF
SHOW THE FRONTOGENESIS GRADUALLY INCREASING AND BECOMING DEEPER
ALONG THE FRONT STARTING MONDAY. BY LATE MONDAY NIGHT INTO TUESDAY
MORNING...THE FRONTOGENESIS IS EXPECTED TO BE MODERATE IN
STRENGTH IN THE 1000-850 MB LAYER AND WEAK IN THE 850-500 MB
LAYER. THE NEXT SURFACE LOW WILL BE TAKING SHAPE OVER NEBRASKA OR
SOUTH DAKOTA ALONG THE WESTERN PART OF THE FRONT. AS THIS
CONTINUES TO DEVELOP...THE LOW LEVEL WARM AIR ADVECTION OVER THE
FRONT WILL BE INCREASING WITH THE ECMWF SHOWING AROUND 2 UBAR/S
OF UP GLIDE ON THE 315K ISENTROPIC SURFACE OVER THE FRONT. THESE
HAVE BEEN CONSISTENT SIGNALS SO HAVE RAISED THE RAIN CHANCES UP TO
50 PERCENT FOR A GOOD SHARE OF THE AREA NORTH OF THE FRONT. THE
MOISTURE TRANSPORT INTO THE FRONT DOES NOT LOOK TO BE VERY STRONG
WITH BOTH THE NAM AND ECMWF SUGGESTING IT WILL BE MORE PARALLEL TO
THE FRONT INSTEAD OF INTO IT. THE FORCING THEN STARTS TO WEAKEN
BUT DOES NOT TOTALLY DISSIPATE TUESDAY AFTERNOON SO MAINTAINED A
30 PERCENT CHANCE FOR MUCH OF THE AREA.
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
227 AM CDT SUN JUL 22 2012
BOTH THE 21.12Z AND 22.00Z RUNS OF THE ECMWF HAVE SUGGESTED A
PATTERN SHIFT WILL BE TAKING PLACE THROUGH THE EXTENDED. THE MEAN
UPPER LEVEL RIDGE IS EXPECTED TO GET FLATTENED AND PUSHED TO THE
SOUTHEAST AS AN UPPER LEVEL LOW MOVES ALONG THE CANADIAN BORDER.
AS THIS SYSTEM MOVES BY LATE IN THE PERIOD...THE RIDGE THEN DOES
NOT BUILD BACK OVER THE ROCKIES NEARLY AS STRONG AS ANOTHER STORM
SYSTEM LOOKS TO BE MOVING ONSHORE WITH MEAN TROUGHING DEVELOPING
ALONG THE WEST COAST KEEPING THE FLOW OVER THE UPPER MIDWEST MORE
OF A ZONAL TO WEAK NORTHWEST PATTERN. AS THE UPPER LEVEL LOW
APPROACHES...THE SURFACE LOW WILL TRACK EAST ALONG THE FRONTAL
BOUNDARY WITH INCREASING FRONTOGENESIS AND ISENTROPIC UP GLIDE.
THIS FORCING WILL COMBINE WITH THE LIFT AHEAD OF THE UPPER LEVEL
LOW AND PROVIDE GOOD FORCING FOR RAIN OVER THE AREA TUESDAY NIGHT
INTO WEDNESDAY NIGHT. THE RAIN CHANCES WILL CONTINUE THURSDAY INTO
FRIDAY BUT WILL BE ON THE DECREASE AS THE SYSTEM MOVES SLOWLY PAST
THE AREA.
&&
.AVIATION...TONIGHT AND SUNDAY
1141 PM CDT SAT JUL 21 2012
SUBTLE SHORT WAVE TROUGH GENERATING ENOUGH LIFT AND LOW LEVEL
RESPONSE TO SPARK CONVECTION OVER SOUTHWEST MINNESOTA LATE THIS
EVENING AS FORECAST. MESOSCALE MODELS TRACK THIS EAST-SOUTHEAST SO
EXPECT SOME IMPACT TO TAF SITES BUT SHOULD STILL REMAIN MAINLY VFR.
ADDED THREAT FOR -TSRA AT KRST AFTER 22/07Z BUT EXPECT CONVECTION TO
WEAKEN AS IT PROGRESSES EAST BY DAYBREAK.
AFTER THIS MORNING SHOWER ACTIVITY...HARD TO FIND ANY TYPE OF
FEATURE THAT WOULD GENERATE MORE LATER IN THE DAY SO EXCEPT FOR SOME
OCCASIONAL MID/HIGH LEVEL CLOUDS...VFR CONDITIONS TO PREVAIL INTO
SUNDAY NIGHT AND BROAD UPPER RIDGE CONTINUES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
227 AM CDT SUN JUL 22 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION.....SHEA
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
200 AM MST TUE JUL 24 2012
.SYNOPSIS...
THUNDERSTORM CHANCES WILL BEGIN TO DECREASE OVER THE NEXT FEW DAYS
AS DRIER AIR SLOWLY WORKS IN FROM THE WEST. AFTER TODAY...STORM
CHANCES WILL MAINLY BE CONFINED TO THE HIGHER TERRAIN AREAS EAST OF
PHOENIX. DRIER AND SLIGHTLY WARMER WEATHER WILL SETTLE ACROSS THE
REGION FOR LATE THIS WEEK INTO THE WEEKEND...BEFORE A MORE ACTIVE
MONSOON PATTERN IS POSSIBLE BY THE EARLY PART OF NEXT WEEK.
&&
.DISCUSSION...
CONVECTION CONTINUES FROM GILA TO YAVAPAI COUNTIES THIS
MORNING...SENDING OUTFLOWS INTO THE VALLEY AND SPAWNING ISOLATED
SHOWERS AND THUNDERSTORMS AS FAR WEST AS THE ESTRELLA MOUNTAINS AS
OF 2 AM. NOT MUCH IN THE WAY OF SEVERE WEATHER PER SE...BUT THERE
HAVE BEEN REPORTS OF NEARLY 2 INCHES OF RAIN SINCE APPROX 10PM LAST
EVENING WITH THE STRONGEST STORMS. ONLY THE HRRR MODEL HAS ANY SENSE
OF WHATS GOING ON AT THE MOMENT...SHOWING STORMS DIMINISHING AROUND
12Z. WITH THIS IN MIND...I WILL MAINTAIN A CHANCE OF SHOWERS AND
THUNDERSTORMS IN THE FORECAST THROUGH THE PRE-DAWN HOURS EAST OF
PHOENIX.
ONGOING CONVECTION AND NUMEROUS OUTFLOWS ARE WREAKING HAVOC ON OUR
PRECIP CHANCES FOR LATER TODAY. ATMOSPHERE REMAINS PRIMED FOR
CONVECTION AT THE MOMENT PROVIDED THERE IS ENOUGH FORCING IN
PLACE...BUT MOISTURE WILL BEGIN ERODING FROM THE WEST LATER THIS
AFTERNOON AND CONSEQUENTLY...INSTABILITY IS EXPECTED TO DIMINISH
RAPIDLY BY 00Z. ON TOP OF THAT...THE ATMOSPHERE WILL ALMOST
CERTAINLY BE WORKED OVER ACROSS THE HIGHER TERRAIN. WHILE IT APPEARS
THERE IS STILL A CHANCE OF STORMS LATER TODAY...I HAVE REDUCED POPS
GIVEN THE ABOVE CONCERNS. AREAL COVERAGE AND EXTENT OF STORMS WOULD
HAVE BEEN LESSER TODAY ANYWAY GIVEN ERODING MOISTURE BUT I THINK
THIS OVERNIGHT COMPLEX WILL LESSEN COVERAGE EVEN MORE.
A BIT OF A BREAK FROM THE MONSOON LOOKS LIKELY FROM WEDNESDAY
THROUGH SATURDAY AS MOISTURE DECREASES AND INSTABILITY DROPS TO
NOTHING. PRECIP CHANCES WERE CHANGED ONLY SLIGHTLY EACH
DAY...GENERALLY CLIMO MINUS 10 OR 15 PERCENT. SOME SUGGESTION OF AN
EASTERLY WAVE/INVERTED TROUGH MOVING THROUGH THE AREA LATE THIS
WEEKEND INTO EARLY NEXT WEEK. WITH THIS IN MIND...I STARTED BRINGING
POPS BACK INTO THE DESERTS ON SUNDAY AND MONDAY ALTHOUGH FIGURING
OUT THE EXACT TIMING THIS FAR IN ADVANCE IS TRICKY AT BEST.
&&
.AVIATION...
SOUTH CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
MAINLY EAST TO SOUTHEAST WIND FOR TERMINALS TONIGHT AND TOMORROW
MORNING. SLIGHT CHANCE FOR A THUNDERSTORM THIS EVENING UNTIL AROUND
06Z...BUT NOT ENOUGH CONFIDENCE IN TIMING OR LOCATION OF STORM
DEVELOPMENT TO INCLUDE VCTS IN THE TAFS.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
WINDS MOSTLY FROM THE SOUTH ACROSS THE REGION. NO STORMS EXPECTED
TONIGHT.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
EXPECT THUNDERSTORM ACTIVITY TO BEGIN PICKING UP AGAIN BEGINNING
FRIDAY AND RUNNING THROUGH THE WEEKEND. HUMIDITIES WILL ALSO BE
INCREASING THROUGH THE WEEKEND. MOST ACTIVITY SHOULD BE TO THE EAST
OF THE COLORADO RIVER.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...LEINS
AVIATION...DG
FIRE WEATHER...WATERS
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1244 AM EDT TUE JUL 24 2012
.SYNOPSIS...
A STRONG COLD FRONT OVER THE GREAT LAKES WILL TRACK SOUTHEAST
INTO OUR AREA TODAY. THIS FRONT EVENTUALLY STALLS TO OUR SOUTH ON
WEDNESDAY AS HIGH PRESSURE BRIEFLY INFLUENCES OUR AREA. ON THURSDAY
INTO FRIDAY, A WARM FRONT WILL LIFT NORTHEAST THROUGH THE REGION,
FOLLOWED BY A COLD FRONT FROM THE WEST TRACKING ACROSS THE MID
ATLANTIC AROUND SATURDAY. A HIGH PRESSURE SYSTEM WILL THEN BUILD
INTO THE NORTHEAST ON SUNDAY AND MONDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE LINE OF CONVECTIVE LOOKING ELEMENTS APPROACHING THE DELAWARE
VALLEY HAS DIMINISHED...EVEN THOUGH THE AIRMASS IS STILL MARGINALLY
UNSTABLE. THE INSTABILITY APPEARS TO HAVE BECOME MORE ELEVATED...BASED
ON THE EXPANDING CLUTTER ON THE KDIX RADAR...AND THE PATCHY FOG
TRYING TO FORM HERE AT THE OFFICE (AND OTHER PLACES RAIN FELL).
THIS ACTIVITY WILL BE REMOVED FROM THE FORECAST WITH THE NEXT
UPDATE.
THE NEXT PROBLEM IS THE CONVECTION FORMING EAST OF LAKE ERIE...IN
THE POOL OF THE BEST AVAILABLE INSTABILITY. IT WOULD APPEAR THAT
MOST OF THE CONVECTIVE WOULD CONTINUE MOVING EAST IN THE WEST
NORTHWEST MID LEVEL FLOW...FOLLOWING THE BEST LOW TO MID LEVEL
THETA E. THE LATEST RUN OF THE HRRR KEEPS THE ACTIVITY OUT OF THE
AREA...AS DOES THE 0000 UTC NAM. THE CURRENT FORECAST CARRIES ONLY
A SLIGHT CHANCE FAR NORTH...AND THIS WILL BE RETAINED FOR NOW.
PATCHY FOG IS FORMING IN LOCATIONS WHERE IT RAINED...AND THE
MENTION OF PATCHY FOG WILL BE EXPANDED TO INCLUDE PORTIONS OF
CENTRAL NEW JERSEY AND THE LEHIGH VALLEY. NO SIGNIFICANT CHANGES
TO THE TEMPERATURES OR WINDS FOR THE OVERNIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THIS EVENING/...
NORTHWEST FLOW ALOFT WILL LIKELY CARRY ANY SHORTWAVES AND TSTM
ACTIVITY AWAY FROM OUR CWA LATE TONIGHT AND TUE. DRIER BUT STILL
RATHER WARM AIR WILL BE ACROSS THE REGION TUESDAY. WE WILL JUST KEEP
LOW CHC POPS FOR A TSTM ACROSS THE AREA TUE WITH SOMEWHAT HIGHER CHC
ACROSS THE LOWER DELMARVA. HIGH TEMPERATURES TUE WILL BE MOSTLY IN
THE UPPER 80S TO LOW 90S...BUT SOME MID 90S MAY OCCUR OVER DELAWARE
AND THE MD ERN SHORE. HUMIDITY LEVELS WILL BE LESS THAN TODAY SO
HEAT INDEX VALUES WILL BE LOW ENOUGH TO PRECLUDE ANY HEAT HEADLINES
ATTM.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
WE HAVE SEEN SIMILAR INITIALIZATION WINNERS AGAIN TODAY WITH THE GFS
SLIGHTLY BETTER THAN THE WRF-NMMB AT 850MB (TEMPS AND DEWS) AND
925MB AND THE WRF-NMMB AT 500MB. SO THE GENERAL IDEAS OF THE
WRF-NMMB WERE FOLLOWED MORE WITH THE GFS THERMAL FIELDS USED FOR
SFC ADJUSTMENTS.
WE CONTINUED A LOW CHANCE EARLY FOR LEFTOVER TSTMS SOUTH. OTHERWISE,
CLEARING AND COOLER WEATHER IS FORECAST FOR TUESDAY NIGHT. BECAUSE
THE GRADIENT MIGHT BE SUFFICIENT, WE DID NOT LOWER THE MINS TO THE
DEW POINTS. STAT GUIDANCE OVERALL LOOKS REASONABLE.
WEDNESDAY STILL IS ON TAP TO BE "THE DAY" THIS WEEK WITH MOSTLY
SUNNY SKIES AND LOW HUMIDITY LEVELS. FCST 1000-850MB THICKNESSES AND
925MB TEMPS ARE STILL SUGGESTING A WARM DAY WITH MANY MAX TEMPS IN
THE MID TO UPPER 80S PRETTY MUCH IN LINE WITH CURRENT FCST AND STAT
GUIDANCE.
THE MODEL TREND BEYOND WEDNESDAY HAS BEEN TOWARD A FASTER RETURN OF
HOTTER AND MORE HUMID WEATHER AS WELL AS PRECIPITATION CHANCES. AN
ANOMALOUSLY STRONG LOW PRESSURE SYSTEM FOR JULY IS EXPECTED TO PASS
NORTH OF OUR CWA ON THURSDAY. WHILE THE GFS SOLUTION IS A VERY
ROBUST OUTLIER, THE GENERAL IDEA OF THE OTHER MODELS ARE THE
SAME. WE HAVE STARTED THE CHANCE OF WAA INDUCED PRECIPITATION IN
THE NORTHERN PART OF OUR CWA AFTER MIDNIGHT. ITS POSSIBLE THUNDER
MIGHT GET INVOLVED. BUT GIVEN THE GFS ROBUST SOLUTION IS THE
QUICKEST, WE OPTED TO LEAVE IT OUT FOR NOW. ITS ALSO POSSIBLE THAT
THE WAA INDUCED PCPN MIGHT STAY NORTH OF OUR CWA, BUT EVENTS LIKE
THIS TEND TO SEEP SOUTH MORE THAN THE MODELS THINK.
EVEN THROTTLING BACK THE GFS TO THE FOLD ON THURSDAY, IT SHOULD BE A
HOTTER AND MORE HUMID DAY WITH LEGITIMATE THUNDERSTORM CHANCES.
HIGHEST POPS ARE NORTH CLOSER PROXIMITY TO THE SURFACE LOW AND
FRONTAL BOUNDARY. MAX TEMPS WERE NUDGED UP SOUTH BASED ON SOME BREAK
IN THE CLOUDS. BECAUSE OF THE TREND, WE ARE EDGING CLOSER TO HEAT
CRITERIA FOR URBAN AREAS.
THEN FROM THURSDAY NIGHT INTO SATURDAY, THE FRONTAL BOUNDARY IS
EXPECTED TO REMAIN CLOSE TO OUR CWA. THIS PACKAGE CONTINUED TO LEAN
CLOSER TO THE HPC AND ECMWF SOLUTION THAN THE GFS PARTLY BECAUSE OF
CONTINUITY AND ALSO BECAUSE OF THE RECENT 12Z GFS RUN. THIS
SHOULD BE A RATHER UNSETTLED PERIOD WITH SCATTERED SHOWERS AND
THUNDERSTORMS AROUND UNTIL THE FRONT PASSES ABOUT SATURDAY.
ON SUNDAY, THE FRONTAL SYSTEM SHOULD BE MOVING OFFSHORE AND OUT TO
SEA. HOWEVER, THERE MAY BE SOME LINGERING SHOWERS, ESPECIALLY EARLY,
BEFORE THE MID-LEVEL TROUGH FULLY MOVES THROUGH. BY SUNDAY NIGHT
INTO MONDAY, HIGH PRESSURE AT THE SURFACE IS EXPECTED TO BUILD INTO
THE REGION, WHICH SHOULD PROVIDE DRY WEATHER. THE GFS INDICATES THAT
WE MAY GET SOME SHOWER ACTIVITY DEVELOP DURING THE DAY MONDAY, WHILE
THE ECMWF KEEPS IT DRY. SINCE IT`S PRETTY FAR OUT, WE WILL GO POP
LESS AT THIS TIME. WITH WEAK TROUGHING ACROSS THE NORTHEAST,
TEMPERATURES ARE EXPECTED TO BE RIGHT AROUND NORMAL FOR SUNDAY AND
MONDAY.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
VFR CONDITIONS CONTINUE EARLY THIS MORNING ACROSS THE REGION. PATCHY
FOG IS TRYING TO FORM IN LOCATIONS THAT SAW RAIN MONDAY AFTERNOON
AND EVENING. PLACES LIKE KRDG...KABE AND KMIV MAY SEE PATCHY MVFR
FOG...MAINLY BETWEEN 0800 AND 1100 UTC. SCATTERED THUNDERSTORMS ARE
EXPECTED TO REMAIN NORTH OF THE TERMINAL LOCATIONS DURING THE EARLY
MORNING HOURS.
VFR CONDITIONS ARE EXPECTED TODAY...AS A COLD FRONT CROSSES THE
REGION. SCATTERED THUNDERSTORMS ARE EXPECTED ALONG THE FRONT...BUT
MAINLY SOUTH OF THE AREA. THERE IS A LOW PROBABILITY THAT KILG...
KACY AND KMIV COULD SEE A THUNDERSTORM BETWEEN 1600 AND 2100 UTC.
HOWEVER...THE PROBABILITIES WERE NOT HIGH ENOUGH TO INCLUDE IN THE
NEW TERMINAL FORECASTS. WEST TO WEST NORTHWEST WINDS WILL GUST
BETWEEN 21 AND 26 KNOTS BETWEEN 1500 AND 2300 UTC.
VFR CONDITIONS ARE EXPECTED TONIGHT UNDER MAINLY CLEAR SKIES. THE
NORTHERLY GRADIENT WILL INCREASE AFTER 0300 UTC...AND A FEW GUSTS
ARE POSSIBLE AT KACY BETWEEN 0600 UTC AND 0900 UTC WEDNESDAY.
OUTLOOK...
WEDNESDAY AND WEDNESDAY NIGHT...VFR CONDITIONS.
THURSDAY...VFR CONDITIONS FOR THE MORNING. SCATTERED SHOWERS AND
TSTMS MAY PRODUCE SOME MVFR IN THE LATTER PART OF THE DAY.
THURSDAY NIGHT THROUGH FRIDAY...SHWR AND TSTM ACTIVITY
ASSOCIATED WITH A WARM FRONT IS EXPECTED TO YIELD MVFR OR EVEN IFR
FOR A TIME.
FRIDAY NIGHT AND SATURDAY...SOME MVFR TO IFR CONDITIONS POSSIBLE IN
FOG AND LOW CLOUDS FRIDAY NIGHT AND ANY SHOWERS AND TSTMS FRIDAY
NIGHT AND SATURDAY.
&&
.MARINE...
NO MARINE FLAGS WILL BE NEEDED DURING THE OVERNIGHT, AND LIKELY
NONE WILL BE NEEDED ON TODAY. SCT TSTMS WITH LOCAL HIGHER WINDS/SEAS
ARE THE PRIMARY HAZARDS IN THE SHORT TERM. SYNOPTIC WINDS MOSTLY S
OR SW TODAY THEN N OR NW TUESDAY. WIND SPEEDS MOSTLY 10 TO 15 KTS
WITH A FEW G20 TODAY.
OUTLOOK...
THERE IS A CHANCE FOR SMALL CRAFT ADVISORY CRITERIA TONIGHT
ON THE OCEAN IN THE COOL AIR ADVECTION. EVEN IF IT WERE TO OCCUR,
THE DURATION IS LIKELY TO BE CONFINED TO JUST TONIGHT. BEYOND THAT
WINDS AND SEAS SHOULD BE FURTHER AWAY FROM SMALL CRAFT ADVISORY
CRITERIA ON WEDNESDAY AS WEAKENING HIGH PRESSURE BUILDS INTO THE
COASTAL WATERS.
THE NEXT CHANCE FOR SMALL CRAFT ADVISORY CONDITIONS MAY COME ON
THURSDAY IN THE SOUTHWEST FLOW BETWEEN THE DEPARTING HIGH AND THE
APPROACHING LOW PRESSURE SYSTEM. BECAUSE THE GFS SOLUTION WAS SO
ROBUST, WE TOOK ABOUT 1 TO 2 FT OFF THE 12Z WAVE WATCH GUIDANCE AND
ARE NOT CONFIDENT ABOUT GRADIENT WIND GUSTS REACHING THE CRITERIA.
HIGHER CHANCE OVER THE OCEAN THAN THE BAY. WE WILL CONTINUE TO
MONITOR.
AFTER THURSDAY NIGHT, THE FRONTAL PROXIMITY SHOULD KEEP WINDS AND
SEAS BELOW CRITERIA AGAIN INTO SATURDAY WITH LOCAL CONDITIONS AROUND
THUNDERSTORMS AND POSSIBLY SOME FOG BEING THE LARGER MARINE
THREATS.
&&
.RIP CURRENTS...
THE IS A MODERATE RISK OF RIP CURRENTS FORECAST TODAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GIGI/KLINE
NEAR TERM...HAYES
SHORT TERM...O`HARA
LONG TERM...GIGI/ROBERTSON
AVIATION...GIGI/HAYES/KLINE
MARINE...GIGI/KLINE/O`HARA
RIP CURRENTS...DELISI
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
255 AM CDT TUE JUL 24 2012
.DISCUSSION...
857 PM...EVENING UPDATE...EXTENSIVE MID/HIGH CLOUDS CONTINUE TO
SPREAD SOUTHEAST ACROSS THE AREA THIS EVENING WITH SOME SPRINKLES
AND A FEW LIGHT SHOWERS. HAVE SEEN VERY LITTLE CONVECTIVE
DEVELOPMENT AND THESE TRENDS APPEAR TO CONTINUE INTO THE EARLY
MORNING HRS AND WILL BE BACKING OFF TO JUST A SLIGHT CHANCE OF
SHOWERS FOR THE REST OF THIS EVENING. A STRONGER WAVE CURRENTLY
MOVING SOUTHEAST ACROSS MN AND NORTHWEST WI APPEARS TO HAVE A BIT
BETTER ORGANIZED AREA OF PRECIP WITH IT...BUT STILL RATHER MEAGER.
AS THIS CONTINUES TO THE SOUTHEAST OVERNIGHT...SHORT RANGE
GUIDANCE STILL SUGGESTS THAT ADDITIONAL SHOWERS AND THUNDERSTORMS
MAY DEVELOP ACROSS NORTHERN IL AND NORTHWEST INDIANA...GENERALLY
AFTER 08Z- 09Z. FOR THIS REASON...WILL HANG ONTO GOING LIKELY POPS
BUT CONFIDENCE REGARDING COVERAGE ARE LOW. RATHER IMPRESSIVE
PRECIPITABLE WATER VALUES AT OR SLIGHTLY ABOVE 2 INCHES TOWARD
DAYBREAK TUESDAY...THUS ANYTHING THAT DOES DEVELOP WILL CONTINUE
TO HAVE THE POTENTIAL TO PRODUCE LOCALLY HEAVY RAIN. ELSEWHERE...
THE COLD FRONT CONTINUES TO SLOWLY SAG SOUTH AND APPEARS TO HAVE
SLOWED FROM PREVIOUS TIMING. WOULD EXPECT SOME MOISTURE POOLING
AHEAD OF THE FRONT BUT DEWPOINTS ARE ALREADY IN THE MID TO EVEN A
FEW UPPER 70S ACROSS THE AREA. OVERNIGHT HRS WILL REMAIN QUITE
WARM AND MUGGY. CMS
//PREV DISCUSSION...
342 PM CDT
MAIN CONCERNS AND QUESTIONS REVOLVE AROUND CHANCES FOR SHOWERS AND
THUNDERSTORMS LATE THIS AFTERNOON INTO THE
EVENING...OVERNIGHT...AS WELL AS OVER THE NEXT SEVERAL DAYS WITH
SEVERE WEATHER AND HEAVY RAINFALL A CONCERN FOR EACH TIME FRAME.
IN THE NEAR TERM...SCATTERED MID AND HIGH LEVEL CLOUD COVER
CONTINUE TO SPILL SOUTHEAST ACROSS MUCH OF THE CWA. ALTHOUGH THERE
HAVE BEEN SOME BREAKS OBSERVED TODAY...THE MAJORITY OF THE DAY HAS
OBSERVED PARTLY CLOUDY TO PARTLY SUNNY SKIES. THIS CLOUD COVER HAS
LIMITED OVERALL TEMPS TODAY WITH MOST AREAS NOT QUITE RISING AS
HIGH AS PREVIOUSLY ANTICIPATED. WITH THE BREAKS...IT DIDNT TAKE
MUCH FOR SURFACE TEMPS TO RISE INTO THE MID 90S WITH SOME ISOLATED
UPPER 90S. THIS GENERAL TREND HAS BEEN GOOD WITH REGARD TO THE
HEAT AND HUMIDITY WHICH WAS EXPECTED TODAY...AS DEWPOINTS DID NOT
QUITE MIX OUT WITH MANY LOCATIONS ACROSS NORTHERN ILLINOIS
CURRENTLY OBSERVING LOW TO MID 70 DEWPOINTS. AREAS MAY OBSERVE
TEMPS RISE A COUPLE OF DEGREES OVER THE NEXT COUPLE OF
HOURS...BEFORE THICKER CLOUD COVER UPSTREAM ACROSS SOUTHWEST
WISCONSIN MOVES SOUTHEAST ACROSS THE CWA AND STIFLES ANY FURTHER
HEATING. WITH SEVERAL RIPPLES IN THE FLOW ALOFT SHIFTING OVERHEAD
TODAY...SCATTERED LIGHT SHOWERS HAVE BEEN OBSERVED ACROSS THE
SOUTHWEST PORTION OF THE CWA TODAY WITH SOME ISOLATED LIGHTNING
STRIKES OBSERVED. WITH A DECENT CAP IN PLACE AND CLOUD COVER
HELPING TO LIMIT LOW AND MID LEVEL LAPSE RATES...CONVECTION HAS
BEEN KEPT IN CHECK TODAY. ALTHOUGH...CONCERNS AND QUESTIONS STILL
REMAIN FOR LATE THIS AFTERNOON INTO THE EVENING. HAVE BEEN
MONITORING A STRONGER MID LEVEL FEATURE DROPPING SOUTHEAST ACROSS
SOUTHEAST MINNESOTA AND SOUTHWEST WISCONSIN WITH LATEST RADAR
IMAGERY SHOWING SOME RETURNS/SHOWERS MOVING INTO EASTERN IOWA. MY
CONCERNS WITH THESE SHOWERS ARE THAT UPSCALE GROWTH COULD OCCUR AS
THEY ENCOUNTER A DESTABILIZING ATMOSPHERE OVER NORTHERN ILLINOIS.
LATEST RUC ANALYSIS IS INDICATING THAT THE ATMOSPHERE IS
DESTABILIZING WITH CIN ERODING AND LOW LEVEL LAPSE RATES
STEEPENING. ALTHOUGH THIS IS PROBABLY OCCURRING...I WONDER IF THIS
LATEST ANALYSIS MIGHT BE OVERDONE. WHERE FAIRLY STEEP LAPSE RATES
OVERLAP THIS MID LEVEL WAVE/SHOWERS...LIGHTNING AND UPSCALE GROWTH
HAS BEEN NONEXISTENT. ALSO...AS MID AND HIGH LEVEL CLOUD COVER
CONTINUE TO MOVE OVERHEAD...NOT ANTICIPATING ANY REAL GOOD
DESTABILIZATION TO CONTINUE ACROSS THE AREA WITH WARM AIR ALOFT
REMAINING. SO DESPITE MY CONCERNS...A BETTER SOLUTION FOR THE NEAR
TERM INTO THE EVENING ARE THAT SHOWERS MOVE INTO NORTHERN ILLINOIS
WITH SOME FURTHER DEVELOPMENT AND ISOLATED STRONGER
DEVELOPMENT...BUT WITH THE PREVIOUSLY MENTIONED LIMITING FACTORS
HELPING TO ONCE AGAIN KEEP THE CONVECTION AND ANY SEVERE POTENTIAL
IN CHECK.
CONCERNS THEN SHIFT TOWARDS LATE TONIGHT INTO EARLY TUESDAY
MORNING. ANOTHER STRONGER AND MORE DEFINED MID LEVEL WAVE NOTED ON
LATEST WATER VAPOR IMAGERY ACROSS THE DAKOTAS WILL DROP SOUTHEAST
ACROSS THE REGION. THIS WAVE WILL ENCOUNTER A STRENGTHENING LOW
LEVEL JET ADVECTING A VERY MOIST AIR MASS INTO IT AND OVER A LOW
LEVEL BAROCLINIC ZONE DROPPING SOUTH THROUGH THE CWA...WITH
DEVELOPMENT EXPECTED ACROSS CENTRAL WISCONSIN. THIS WAVE/FORCING
AND STEERING FLOW WILL SHIFT THIS CLUSTER OF SHOWERS/THUNDERSTORMS
SOUTHEAST ACROSS NORTHERN ILLINOIS AND NORTHWEST INDIANA...WITH
THE BEST CHANCES EXPECTED NORTH OF LINE FROM DIXON IN ILLINOIS TO
FOWLER IN INDIANA AND THE BEST CHANCES WITH REGARDS TO TIMING
EXPECTED TO BE AFTER MIDNIGHT. AS THIS COMPLEX MOVES ACROSS THE
AREA IT WILL ENCOUNTER A VERY MOIST AND UNSTABLE ATMOSPHERE WITH
HIGH DEWPOINT/PWAT AIR IN PLACE. CONCERNS DURING THIS TIME FRAME
WOULD BE FOR SOME ISOLATED LARGE HAIL...BUT WITH CONCERNS MORE
TOWARD THE HEAVY RAIN POTENTIAL. ALTHOUGH THIS DOES NOT APPEAR TO
BE A CLASSIC HEAVY RAIN SETUP...MANY FEATURES ARE IN PLACE TO
PROVIDE SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS THAT WILL ALL
HAVE THE POTENTIAL TO PRODUCE HEAVY DOWNPOURS...INCLUDING LOW
LEVEL FLOW BRIEFLY ORIENTING ITSELF WITH REGARD TO THE BAROCLINIC
ZONE SUCH TO BRING AT LEAST SOME PERIOD OF POTENTIAL TRAINING OF
CELLS. WILL CONTINUE TO MAKE MENTION OF THESE THREATS IN THE HWO
AS WELL AS AN ESF.
RODRIGUEZ
THURSDAY THROUGH MONDAY...MEDIUM RANGE GUIDANCE IS IN PRETTY
DECENT AGREEMENT WITH THE MAIN FEATURES INTO EARLY NEXT WEEK.
SURFACE LOW PRESSURE WILL BE EXITING OFF TO THE EAST THURSDAY
MORNING WITH ITS TRAILING COLD FRONT SOMEWHERE NEAR THE AREA.
GUIDANCE DOES DIFFER ON HOW QUICKLY THE FRONT MOVES ACROSS THE
AREA THURSDAY. WILL KEEP POPS IN WITH THE BEST CHANCE DURING THE
MORNING BUT IT IS POSSIBLE THE FRONT COULD BE EXITING BY THAT
TIME. BEYOND THAT...A CLOSED UPPER LOW CURRENTLY SPINNING OVER
SOUTHERN BRITISH COLUMBIA WILL SLOWLY MOVE EASTWARD INTO UPPER
RIDGING OVER SASKATCHEWAN. BY THURSDAY MORNING...THE LOW WILL BE
IN THE VICINITY OF NORTHWEST MN/NORTHEAST NORTH DAKOTA HEADING
SOUTHEAST BRINGING A SURFACE LOW WITH IT. THIS WILL BEGIN TO
AFFECT THE AREA LATER THURSDAY NIGHT OR FRIDAY MORNING WITH
ANOTHER COOL FRONT DROPPING ACROSS THE AREA. AN UPPER TROUGH AXIS
LOOKS TO LAG THIS SYSTEM SO AT LEAST LOW PRECIP CHANCES WILL
LINGER INTO FRIDAY. SURFACE HIGH PRESSURE THEN ARRIVES INTO
SATURDAY MORNING AS UPPER RIDGING BECOMES RE-ESTABLISHED ACROSS
THE WESTERN U.S. A TROUGH MOVES THROUGH THE RIDGE SPAWNING SURFACE
LOW DEVELOPMENT ACROSS THE HIGH PLAINS LATER SATURDAY AND
SPREADING WARM ADVECTION EASTWARD ACROSS THE LOCAL AREA FOLLOWED
BY THE PASSAGE OF ANOTHER SURFACE LOW INTO MONDAY. THIS WHOLE
SYSTEM RESULTS IN CHANCES FOR SHOWERS AND STORMS FROM LATE SUNDAY
ON. TEMPS LOOK TO REMAIN MORE IN CHECK GIVEN PERIODIC CHANCES FOR
PRECIP...GENERALLY LOWER HEIGHTS OVER THE AREA AND OCCASIONAL
FRONTAL PASSAGES. DEPENDING ON FRONTAL TIMING THURSDAY...SOUTHERN
AREAS MAY REACH THE 90S...BUT OTHER THAN THAT WILL KEEP HIGHS IN
THE MID TO UPPER 80S FOR NOW.
MDB
&&
.CLIMATE...
400 AM CDT
RECORDS HIGHS FOR TODAY JULY 23RD ARE:
CHICAGO 99 /1914/
ROCKFORD 104 /1934/
RECORD WARM LOWS FOR TODAY JULY 23RD ARE:
CHICAGO 78 /1965/
ROCKFORD 76 /1965/
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* SHRA/TSRA EARLY-MID THIS MORNING.
* MVFR...POSSIBLY LOWER...VSBY IN TSRA THIS MORNING. POTENTIAL FOR MVFR
CIGS IN HEAVIER TSRA.
* TSRA TUESDAY AFTERNOON AND NIGHT.
* WIND TRENDS.
RC
//DISCUSSION...UPDATED 06Z...
FOCUS IN THE NEAR TERM IS NW TO SE ORIENTED CLUSTER OF SHRA/TSRA
EXTENDING INTO SE MN/SW WI. A COOL FRONT CONTINUES TO SLOWLY SAG
SOUTH THROUGH WISCONSIN AS WELL. RADAR TRENDS AND LATEST GUIDANCE
POINT TO MN/WI ACTIVITY HOLDING TOGETHER AND MOVING SOUTHEAST OVER
THE TERMINALS EARLY THROUGH MID THIS MORNING...ROUGHLY 9Z-13Z IN
RFD AREA AND 10Z-14Z IN ORD/MDW/DPA/GYY AREA. TIMING MAY NEED
REFINING IN 09Z UPDATE OR SOONER...BUT HAVE DECENT CONFIDENCE
THAT TERMINALS WILL SEE BOTH SHRA AND TSRA DUE TO LOW LEVEL JET
DIRECTING INTO AREA AND PLENTY OF ELEVATED INSTABILITY. THE FRONT
DROPPING SOUTH MAY ALSO PROVIDE A FOCUS FOR MAINTAINING THE
ACTIVITY. IT IS TOO EARLY TO TELL IF TSRA WILL DEVELOP
VARIABLE/GUSTY WINDS...THUS BIGGEST CONCERN IS AT LEAST TEMPORARY
MVFR VSBY IN TSRA AND POSSIBLY A FURTHER LOWERING OF CIGS THAN
INDICATED IN TAFS IN VERY MOIST AIRMASS. PRIOR TO ARRIVAL OF
SHRA/TSRA...CANNOT RULE OUT LIGHT SHRA BREAKING OUT...AND AM ALSO
CONCERNED ACTIVITY COULD LINGER LONGER SO CARRIED -SHRA TO 16/17Z
AT TAF SITES. WILL NEED TO MONITOR TRENDS. AFTER THE MORNING
ACTIVITY...THERE COULD BE ADDITIONAL SHRA/TSRA DURING THE
DAY...BUT NOT CONFIDENT ENOUGH FOR MENTION DURING THIS TIME. A
BETTER CHANCE MAY EXIST LATER IN THE EVENING AS THE FRONTAL
BOUNDARY LIFTS BACK NORTH. INDICATED PROB30 FOR TSRA IN RFD AND
ORD TAFS WITH THIS IN MIND.
WINDS CURRENTLY ARE VERY LIGHT OUT OF THE WEST WHERE THEY ARE NOT
COMPLETELY CALM AND SHOULD REMAIN FAIRLY LIGHT EVEN AS FRONT
PUSHES SOUTH THROUGH THE TERMINALS...TURNING WINDS NORTHEAST. WITH
SOME SITES NORTH OF MKE REPORTING SLIGHTLY STRONGER NORTHEAST
WINDS...WILL NEED TO WATCH FOR THIS OCCURRING AT ORD/MDW/GYY.
WINDS WILL STAY MORE NORTHEASTERLY AT THE EASTERN TAF SITES
BEFORE BECOMING EAST SOUTHEAST LATE TUESDAY EVENING. THE RFD AREA
IS LIKELY TO SEE WINDS EAST-NORTHEAST FOR A TIME AFTER THE FRONTAL
PASSAGE...BUT THEN BECOME EASTERLY BY LATE MORNING AND REMAIN SO
UNTIL POSSIBLY BECOMING MORE EAST-SOUTHEAST TOMORROW EVENING.
RC
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM/HIGH CONFIDENCE IN SHRA/TSRA OCCURRING AT TERMINALS EARLY
THROUGH MID THIS MORNING...LOW CONFIDENCE IN EXACT TIMING AND
DURATION.
* MEDIUM/HIGH CONFIDENCE IN AT LEAST TEMPO MVFR VSBY IN SHRA/TSRA
EARLY THROUGH MID THIS MORNING...LOW CONFIDENCE IN IFR VSBY AND
LOW CONFIDENCE IN MVFR CIGS.
* LOW CONFIDENCE IN TSRA THIS AFTERNOON AND LOW/MEDIUM CONFIDENCE
IN TSRA LATE THIS EVENING.
* MEDIUM CONFIDENCE IN WIND TRENDS...WITH LOW CONFIDENCE IN
NEEDING TO ADD GUSTS TO TSRA ACTIVITY THIS MORNING.
RC
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY THROUGH FRIDAY...CHANCES FOR OCCASIONAL TSRA...OTHERWISE
VFR.
SATURDAY...VFR.
SUNDAY...CHANCE FOR TSRA...ESPECIALLY LATE. OTHERWISE VFR.
RC
&&
.MARINE...
250 AM CDT
A COLD FRONT DROPPING SOUTH ACROSS THE REGION HAS ALL BUT CLEARED
FAR SOUTHERN LAKE MICHIGAN WITH NORTHERLY WINDS TAKING HOLD IN THE
WAKE OF THE FRONT. THIS MORNING...SHOWERS AND THUNDERSTORMS ARE
EXPECTED DEVELOP ALONG AND NORTH OF THE FRONT...IMPACTING THE
SOUTHERN THIRD OR SO OF LAKE MICHIGAN. HIGH PRESSURE WILL BUILD
ACROSS NORTHERN LAKE MICHIGAN TODAY ALLOWING WINDS TO SUBSIDE
ACROSS THE NORTH. WEDNESDAY...LOW PRESSURE WILL DEEPEN OVER THE
NORTHERN PLAINS AS IT MOVES INTO THE UPPER MIDWEST AND WESTERN
GREAT LAKES REGION. THE FRONTAL ZONE WILL LIFT BACK NORTH WITH
SOUTH TO SOUTHEASTERLY WINDS MOVING BACK UP THE LAKE. THE LOW IS
FORECAST TO CROSS MIDLAKE LATE WEDNESDAY EVENING CAUSING WINDS TO
BECOME NORTHEASTERLY ACROSS THE NORTHERN PORTIONS OF THE LAKE.
SOUTHWESTERLY WINDS THE SOUTHERN HALF OF THE LAKE WILL BECOME
NORTHWEST AFTER A TRAILING COLD FRONT SWEEPS ACROSS. WINDS WILL
INCREASE WEDNESDAY AND WEDNESDAY NIGHT...ESPECIALLY ACROSS THE
NORTHERN PART OF THE LAKE WHERE NORTHEAST WINDS TO 30 KT ARE
EXPECTED. ACROSS SOUTHERN LAKE MICHIGAN...20 TO 25 KT OF OFFSHORE
FLOW IS POSSIBLE WEDNESDAY EVENING...BUT A STABLE MARINE LAYER
SHOULD HELP KEEP WINDS IN CHECK OVER THE OPEN WATERS. A SMALL
CRAFT ADVISORY MAY BE NEEDED FOR THE INDIANA AND ILLINOIS
NEARSHORE WATERS. ANOTHER WEAKER LOW PRESSURE SYSTEM WILL CROSS
THE LAKE THURSDAY NIGHT CAUSING ADDITIONAL SHIFTS IN THE WIND
FIELD. HIGH PRESSURE IS EXPECTED TO BUILD INTO THE REGION THIS
WEEKEND OFFERING AT LEAST A BRIEF REPRIEVE FROM THE ACTIVE
WEATHER. BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
138 AM CDT TUE JUL 24 2012
.DISCUSSION...
857 PM...EVENING UPDATE...EXTENSIVE MID/HIGH CLOUDS CONTINUE TO
SPREAD SOUTHEAST ACROSS THE AREA THIS EVENING WITH SOME SPRINKLES
AND A FEW LIGHT SHOWERS. HAVE SEEN VERY LITTLE CONVECTIVE
DEVELOPMENT AND THESE TRENDS APPEAR TO CONTINUE INTO THE EARLY
MORNING HRS AND WILL BE BACKING OFF TO JUST A SLIGHT CHANCE OF
SHOWERS FOR THE REST OF THIS EVENING. A STRONGER WAVE CURRENTLY
MOVING SOUTHEAST ACROSS MN AND NORTHWEST WI APPEARS TO HAVE A BIT
BETTER ORGANIZED AREA OF PRECIP WITH IT...BUT STILL RATHER MEAGER.
AS THIS CONTINUES TO THE SOUTHEAST OVERNIGHT...SHORT RANGE
GUIDANCE STILL SUGGESTS THAT ADDITIONAL SHOWERS AND THUNDERSTORMS
MAY DEVELOP ACROSS NORTHERN IL AND NORTHWEST INDIANA...GENERALLY
AFTER 08Z- 09Z. FOR THIS REASON...WILL HANG ONTO GOING LIKELY POPS
BUT CONFIDENCE REGARDING COVERAGE ARE LOW. RATHER IMPRESSIVE
PRECIPITABLE WATER VALUES AT OR SLIGHTLY ABOVE 2 INCHES TOWARD
DAYBREAK TUESDAY...THUS ANYTHING THAT DOES DEVELOP WILL CONTINUE
TO HAVE THE POTENTIAL TO PRODUCE LOCALLY HEAVY RAIN. ELSEWHERE...
THE COLD FRONT CONTINUES TO SLOWLY SAG SOUTH AND APPEARS TO HAVE
SLOWED FROM PREVIOUS TIMING. WOULD EXPECT SOME MOISTURE POOLING
AHEAD OF THE FRONT BUT DEWPOINTS ARE ALREADY IN THE MID TO EVEN A
FEW UPPER 70S ACROSS THE AREA. OVERNIGHT HRS WILL REMAIN QUITE
WARM AND MUGGY. CMS
//PREV DISCUSSION...
342 PM CDT
MAIN CONCERNS AND QUESTIONS REVOLVE AROUND CHANCES FOR SHOWERS AND
THUNDERSTORMS LATE THIS AFTERNOON INTO THE
EVENING...OVERNIGHT...AS WELL AS OVER THE NEXT SEVERAL DAYS WITH
SEVERE WEATHER AND HEAVY RAINFALL A CONCERN FOR EACH TIME FRAME.
IN THE NEAR TERM...SCATTERED MID AND HIGH LEVEL CLOUD COVER
CONTINUE TO SPILL SOUTHEAST ACROSS MUCH OF THE CWA. ALTHOUGH THERE
HAVE BEEN SOME BREAKS OBSERVED TODAY...THE MAJORITY OF THE DAY HAS
OBSERVED PARTLY CLOUDY TO PARTLY SUNNY SKIES. THIS CLOUD COVER HAS
LIMITED OVERALL TEMPS TODAY WITH MOST AREAS NOT QUITE RISING AS
HIGH AS PREVIOUSLY ANTICIPATED. WITH THE BREAKS...IT DIDNT TAKE
MUCH FOR SURFACE TEMPS TO RISE INTO THE MID 90S WITH SOME ISOLATED
UPPER 90S. THIS GENERAL TREND HAS BEEN GOOD WITH REGARD TO THE
HEAT AND HUMIDITY WHICH WAS EXPECTED TODAY...AS DEWPOINTS DID NOT
QUITE MIX OUT WITH MANY LOCATIONS ACROSS NORTHERN ILLINOIS
CURRENTLY OBSERVING LOW TO MID 70 DEWPOINTS. AREAS MAY OBSERVE
TEMPS RISE A COUPLE OF DEGREES OVER THE NEXT COUPLE OF
HOURS...BEFORE THICKER CLOUD COVER UPSTREAM ACROSS SOUTHWEST
WISCONSIN MOVES SOUTHEAST ACROSS THE CWA AND STIFLES ANY FURTHER
HEATING. WITH SEVERAL RIPPLES IN THE FLOW ALOFT SHIFTING OVERHEAD
TODAY...SCATTERED LIGHT SHOWERS HAVE BEEN OBSERVED ACROSS THE
SOUTHWEST PORTION OF THE CWA TODAY WITH SOME ISOLATED LIGHTNING
STRIKES OBSERVED. WITH A DECENT CAP IN PLACE AND CLOUD COVER
HELPING TO LIMIT LOW AND MID LEVEL LAPSE RATES...CONVECTION HAS
BEEN KEPT IN CHECK TODAY. ALTHOUGH...CONCERNS AND QUESTIONS STILL
REMAIN FOR LATE THIS AFTERNOON INTO THE EVENING. HAVE BEEN
MONITORING A STRONGER MID LEVEL FEATURE DROPPING SOUTHEAST ACROSS
SOUTHEAST MINNESOTA AND SOUTHWEST WISCONSIN WITH LATEST RADAR
IMAGERY SHOWING SOME RETURNS/SHOWERS MOVING INTO EASTERN IOWA. MY
CONCERNS WITH THESE SHOWERS ARE THAT UPSCALE GROWTH COULD OCCUR AS
THEY ENCOUNTER A DESTABILIZING ATMOSPHERE OVER NORTHERN ILLINOIS.
LATEST RUC ANALYSIS IS INDICATING THAT THE ATMOSPHERE IS
DESTABILIZING WITH CIN ERODING AND LOW LEVEL LAPSE RATES
STEEPENING. ALTHOUGH THIS IS PROBABLY OCCURRING...I WONDER IF THIS
LATEST ANALYSIS MIGHT BE OVERDONE. WHERE FAIRLY STEEP LAPSE RATES
OVERLAP THIS MID LEVEL WAVE/SHOWERS...LIGHTNING AND UPSCALE GROWTH
HAS BEEN NONEXISTENT. ALSO...AS MID AND HIGH LEVEL CLOUD COVER
CONTINUE TO MOVE OVERHEAD...NOT ANTICIPATING ANY REAL GOOD
DESTABILIZATION TO CONTINUE ACROSS THE AREA WITH WARM AIR ALOFT
REMAINING. SO DESPITE MY CONCERNS...A BETTER SOLUTION FOR THE NEAR
TERM INTO THE EVENING ARE THAT SHOWERS MOVE INTO NORTHERN ILLINOIS
WITH SOME FURTHER DEVELOPMENT AND ISOLATED STRONGER
DEVELOPMENT...BUT WITH THE PREVIOUSLY MENTIONED LIMITING FACTORS
HELPING TO ONCE AGAIN KEEP THE CONVECTION AND ANY SEVERE POTENTIAL
IN CHECK.
CONCERNS THEN SHIFT TOWARDS LATE TONIGHT INTO EARLY TUESDAY
MORNING. ANOTHER STRONGER AND MORE DEFINED MID LEVEL WAVE NOTED ON
LATEST WATER VAPOR IMAGERY ACROSS THE DAKOTAS WILL DROP SOUTHEAST
ACROSS THE REGION. THIS WAVE WILL ENCOUNTER A STRENGTHENING LOW
LEVEL JET ADVECTING A VERY MOIST AIR MASS INTO IT AND OVER A LOW
LEVEL BAROCLINIC ZONE DROPPING SOUTH THROUGH THE CWA...WITH
DEVELOPMENT EXPECTED ACROSS CENTRAL WISCONSIN. THIS WAVE/FORCING
AND STEERING FLOW WILL SHIFT THIS CLUSTER OF SHOWERS/THUNDERSTORMS
SOUTHEAST ACROSS NORTHERN ILLINOIS AND NORTHWEST INDIANA...WITH
THE BEST CHANCES EXPECTED NORTH OF LINE FROM DIXON IN ILLINOIS TO
FOWLER IN INDIANA AND THE BEST CHANCES WITH REGARDS TO TIMING
EXPECTED TO BE AFTER MIDNIGHT. AS THIS COMPLEX MOVES ACROSS THE
AREA IT WILL ENCOUNTER A VERY MOIST AND UNSTABLE ATMOSPHERE WITH
HIGH DEWPOINT/PWAT AIR IN PLACE. CONCERNS DURING THIS TIME FRAME
WOULD BE FOR SOME ISOLATED LARGE HAIL...BUT WITH CONCERNS MORE
TOWARD THE HEAVY RAIN POTENTIAL. ALTHOUGH THIS DOES NOT APPEAR TO
BE A CLASSIC HEAVY RAIN SETUP...MANY FEATURES ARE IN PLACE TO
PROVIDE SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS THAT WILL ALL
HAVE THE POTENTIAL TO PRODUCE HEAVY DOWNPOURS...INCLUDING LOW
LEVEL FLOW BRIEFLY ORIENTING ITSELF WITH REGARD TO THE BAROCLINIC
ZONE SUCH TO BRING AT LEAST SOME PERIOD OF POTENTIAL TRAINING OF
CELLS. WILL CONTINUE TO MAKE MENTION OF THESE THREATS IN THE HWO
AS WELL AS AN ESF.
RODRIGUEZ
THURSDAY THROUGH MONDAY...MEDIUM RANGE GUIDANCE IS IN PRETTY
DECENT AGREEMENT WITH THE MAIN FEATURES INTO EARLY NEXT WEEK.
SURFACE LOW PRESSURE WILL BE EXITING OFF TO THE EAST THURSDAY
MORNING WITH ITS TRAILING COLD FRONT SOMEWHERE NEAR THE AREA.
GUIDANCE DOES DIFFER ON HOW QUICKLY THE FRONT MOVES ACROSS THE
AREA THURSDAY. WILL KEEP POPS IN WITH THE BEST CHANCE DURING THE
MORNING BUT IT IS POSSIBLE THE FRONT COULD BE EXITING BY THAT
TIME. BEYOND THAT...A CLOSED UPPER LOW CURRENTLY SPINNING OVER
SOUTHERN BRITISH COLUMBIA WILL SLOWLY MOVE EASTWARD INTO UPPER
RIDGING OVER SASKATCHEWAN. BY THURSDAY MORNING...THE LOW WILL BE
IN THE VICINITY OF NORTHWEST MN/NORTHEAST NORTH DAKOTA HEADING
SOUTHEAST BRINGING A SURFACE LOW WITH IT. THIS WILL BEGIN TO
AFFECT THE AREA LATER THURSDAY NIGHT OR FRIDAY MORNING WITH
ANOTHER COOL FRONT DROPPING ACROSS THE AREA. AN UPPER TROUGH AXIS
LOOKS TO LAG THIS SYSTEM SO AT LEAST LOW PRECIP CHANCES WILL
LINGER INTO FRIDAY. SURFACE HIGH PRESSURE THEN ARRIVES INTO
SATURDAY MORNING AS UPPER RIDGING BECOMES RE-ESTABLISHED ACROSS
THE WESTERN U.S. A TROUGH MOVES THROUGH THE RIDGE SPAWNING SURFACE
LOW DEVELOPMENT ACROSS THE HIGH PLAINS LATER SATURDAY AND
SPREADING WARM ADVECTION EASTWARD ACROSS THE LOCAL AREA FOLLOWED
BY THE PASSAGE OF ANOTHER SURFACE LOW INTO MONDAY. THIS WHOLE
SYSTEM RESULTS IN CHANCES FOR SHOWERS AND STORMS FROM LATE SUNDAY
ON. TEMPS LOOK TO REMAIN MORE IN CHECK GIVEN PERIODIC CHANCES FOR
PRECIP...GENERALLY LOWER HEIGHTS OVER THE AREA AND OCCASIONAL
FRONTAL PASSAGES. DEPENDING ON FRONTAL TIMING THURSDAY...SOUTHERN
AREAS MAY REACH THE 90S...BUT OTHER THAN THAT WILL KEEP HIGHS IN
THE MID TO UPPER 80S FOR NOW.
MDB
&&
.CLIMATE...
400 AM CDT
RECORDS HIGHS FOR TODAY JULY 23RD ARE:
CHICAGO 99 /1914/
ROCKFORD 104 /1934/
RECORD WARM LOWS FOR TODAY JULY 23RD ARE:
CHICAGO 78 /1965/
ROCKFORD 76 /1965/
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* SHRA/TSRA EARLY-MID THIS MORNING.
* MVFR...POSSIBLY LOWER...VSBY IN TSRA THIS MORNING. POTENTIAL FOR MVFR
CIGS IN HEAVIER TSRA.
* TSRA TUESDAY AFTERNOON AND NIGHT.
* WIND TRENDS.
RC
//DISCUSSION...UPDATED 06Z...
FOCUS IN THE NEAR TERM IS NW TO SE ORIENTED CLUSTER OF SHRA/TSRA
EXTENDING INTO SE MN/SW WI. A COOL FRONT CONTINUES TO SLOWLY SAG
SOUTH THROUGH WISCONSIN AS WELL. RADAR TRENDS AND LATEST GUIDANCE
POINT TO MN/WI ACTIVITY HOLDING TOGETHER AND MOVING SOUTHEAST OVER
THE TERMINALS EARLY THROUGH MID THIS MORNING...ROUGHLY 9Z-13Z IN
RFD AREA AND 10Z-14Z IN ORD/MDW/DPA/GYY AREA. TIMING MAY NEED
REFINING IN 09Z UPDATE OR SOONER...BUT HAVE DECENT CONFIDENCE
THAT TERMINALS WILL SEE BOTH SHRA AND TSRA DUE TO LOW LEVEL JET
DIRECTING INTO AREA AND PLENTY OF ELEVATED INSTABILITY. THE FRONT
DROPPING SOUTH MAY ALSO PROVIDE A FOCUS FOR MAINTAINING THE
ACTIVITY. IT IS TOO EARLY TO TELL IF TSRA WILL DEVELOP
VARIABLE/GUSTY WINDS...THUS BIGGEST CONCERN IS AT LEAST TEMPORARY
MVFR VSBY IN TSRA AND POSSIBLY A FURTHER LOWERING OF CIGS THAN
INDICATED IN TAFS IN VERY MOIST AIRMASS. PRIOR TO ARRIVAL OF
SHRA/TSRA...CANNOT RULE OUT LIGHT SHRA BREAKING OUT...AND AM ALSO
CONCERNED ACTIVITY COULD LINGER LONGER SO CARRIED -SHRA TO 16/17Z
AT TAF SITES. WILL NEED TO MONITOR TRENDS. AFTER THE MORNING
ACTIVITY...THERE COULD BE ADDITIONAL SHRA/TSRA DURING THE
DAY...BUT NOT CONFIDENT ENOUGH FOR MENTION DURING THIS TIME. A
BETTER CHANCE MAY EXIST LATER IN THE EVENING AS THE FRONTAL
BOUNDARY LIFTS BACK NORTH. INDICATED PROB30 FOR TSRA IN RFD AND
ORD TAFS WITH THIS IN MIND.
WINDS CURRENTLY ARE VERY LIGHT OUT OF THE WEST WHERE THEY ARE NOT
COMPLETELY CALM AND SHOULD REMAIN FAIRLY LIGHT EVEN AS FRONT
PUSHES SOUTH THROUGH THE TERMINALS...TURNING WINDS NORTHEAST. WITH
SOME SITES NORTH OF MKE REPORTING SLIGHTLY STRONGER NORTHEAST
WINDS...WILL NEED TO WATCH FOR THIS OCCURRING AT ORD/MDW/GYY.
WINDS WILL STAY MORE NORTHEASTERLY AT THE EASTERN TAF SITES
BEFORE BECOMING EAST SOUTHEAST LATE TUESDAY EVENING. THE RFD AREA
IS LIKELY TO SEE WINDS EAST-NORTHEAST FOR A TIME AFTER THE FRONTAL
PASSAGE...BUT THEN BECOME EASTERLY BY LATE MORNING AND REMAIN SO
UNTIL POSSIBLY BECOMING MORE EAST-SOUTHEAST TOMORROW EVENING.
RC
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM/HIGH CONFIDENCE IN SHRA/TSRA OCCURRING AT TERMINALS EARLY
THROUGH MID THIS MORNING...LOW CONFIDENCE IN EXACT TIMING AND
DURATION.
* MEDIUM/HIGH CONFIDENCE IN AT LEAST TEMPO MVFR VSBY IN SHRA/TSRA
EARLY THROUGH MID THIS MORNING...LOW CONFIDENCE IN IFR VSBY AND
LOW CONFIDENCE IN MVFR CIGS.
* LOW CONFIDENCE IN TSRA THIS AFTERNOON AND LOW/MEDIUM CONFIDENCE
IN TSRA LATE THIS EVENING.
* MEDIUM CONFIDENCE IN WIND TRENDS...WITH LOW CONFIDENCE IN
NEEDING TO ADD GUSTS TO TSRA ACTIVITY THIS MORNING.
RC
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY THROUGH FRIDAY...CHANCES FOR OCCASIONAL TSRA...OTHERWISE
VFR.
SATURDAY...VFR.
SUNDAY...CHANCE FOR TSRA...ESPECIALLY LATE. OTHERWISE VFR.
RC
&&
.MARINE...
300 PM CDT
RATHER ACTIVE FORECAST PERIOD LIES AHEAD WITH THE FIRST OF SEVERAL
LOWS AND FRONTS AFFECTING THE LAKE THIS AFTERNOON. SURFACE LOW
PRESSURE HAS MOVES INTO CENTRAL QUEBEC AND WILL LIFT NORTHEASTWARD
WHILE DEEPENING AS IT REACHES NEWFOUNDLAND TUESDAY MORNING/EARLY
AFTERNOON. THE COLD FRONT ASSOCIATED WITH THIS LOW IS MAKING
SOUTHEASTWARD PROGRESS AND RUNS FROM NEAR THE STRAITS OF MACKINAC
SOUTHEASTWARD TO NEAR MANITOWOC AT 2 PM CDT. WINDS WILL TURN
NORTHERLY AS THE FRONT PASSES THROUGH THE EVENING. IT APPEARS THAT
THERE MAY BE A BRIEF PERIOD OF STRONGER WINDS FROM NEAR THE MANITOU
ISLANDS NORTHWARD TO THE STRAITS EARLY THIS EVENING BEHIND THE FRONT
WITH 25 KT GUSTS POSSIBLE BEFORE SETTLING DOWN. A SIMILAR INCREASE
IN SPEEDS MAY OCCUR EARLY TONIGHT ACROSS THE SOUTHERN PART OF THE
LAKE BEHIND THE FRONT. HIGH PRESSURE WILL APPROACH TUESDAY ALLOWING
WINDS TO DIMINISH WITH A NORTHEASTERLY DIRECTION IN PLACE.
ATTENTION THEN TURNS TO LOW PRESSURE DEVELOPING ACROSS
THE CENTRAL/NORTHERN PLAINS INTO WEDNESDAY. THIS LOW LOOKS TO
REACH THE LAKE WEDNESDAY EVENING BUT THE STRENGTH IS SOMEWHAT IN
QUESTION. SOME MODEL GUIDANCE CONTINUES TO REALLY DEEPEN IN AS IT
CROSSES THE LAKE BUT THIS STILL LOOKS OVERDONE. DO EXPECT A LOW
WITH A PRESSURE OF AROUND 29.5 INCHES...THOUGH IT COULD BE
STRONGER...TO CROSS THE CENTRAL PART OF THE LAKE. SOUTH WINDS WILL
INCREASE AHEAD OF THE LOW ACROSS THE SOUTHERN HALF OF THE LAKE
WEDNESDAY MORNING WHILE EAST OR NORTHEAST WINDS WILL OCCUR NORTH.
DEPENDING ON THE STRENGTH OF THE LOW WIND SPEEDS MAY NEED TO BE
INCREASED OVER CURRENT FORECAST VALUES. SHOULD A MUCH DEEPER
SCENARIO PAN OUT...WHICH AGAIN LOOKS TO BE A RATHER LOW
PROBABILITY...THEN GALES COULD DEVELOP. THE LOW THEN CLEARS TO THE
EAST THURSDAY MORNING LEAVING A WEAK PRESSURE GRADIENT BEHIND IT
BUT AHEAD OF A WEAKER LOW WHICH WILL CROSS THE LAKE FRIDAY
MORNING. HIGH PRESSURE WILL GRADUALLY BUILD ON SATURDAY.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1155 PM CDT MON JUL 23 2012
...UPDATED AVIATION DISCUSSION...
.UPDATE /HEAT/...
FOR PUBLIC AWARENESS...HAVE DECIDED TO ISSUE A HEAT ADVISORY THROUGH
WEDNESDAY ON THE NORTH AND EAST SIDES OF THE EXISTING HEAT WARNING.
TWO DAYS HAVE ALREADY SEEN TEMPERATURES NEAR OR ABOVE 100...SOMEWHAT
WARMER THAN ANTICIPATED...AND NIGHTS WILL BE WARM. STILL SOME
UNCERTAINTY WHETHER SURFACE BOUNDARY...WHICH IS CURRENTLY RUNNING
FROM ALGONA TO NORTH OF WATERLOO...WILL SAG FARTHER SOUTH PER
SEVERAL NUMERICAL MODELS. HOWEVER...WITH 00Z SOUNDINGS NOT REALLY
FAVORABLE FOR CONVECTION IN IOWA AND CURRENT ACTIVITY DEVELOPING
WELL NORTH IN WESTERN MINNESOTA...IT APPEARS ANY BOUNDARY PUSH SOUTH
WILL NOT LAST TOO LONG. ANOTHER FACTOR CONSIDERED IS THAT DEWPOINTS
JUMP INTO 70S NORTH OF THAT BOUNDARY...PROVIDING LITTLE RELIEF.
WAITING TO SEE THE 00Z MODELS...BUT WEDNESDAY COULD BE HOTTEST YET
WITH A VERY WARM START IF BOUNDARY REMAINS NORTH.
.SHORT TERM /TONIGHT/...
MAIN FORECAST CONCERN IS POTENTIAL FOR CONVECTION ACROSS NORTHERN
IOWA TONIGHT. WEAK BOUNDARY EXTENDS ACROSS SOUTHERN MN COMBINED WITH
AN 500MB VORT MAX WILL BE THE FOCUS FOR THUNDERSTORMS LATER THIS
EVENING INTO TUESDAY MORNING.
NAM/SREF/RAP KEEP CONVECTION ALONG THE BORDER OVERNIGHT...4.0KM WRF
FROM NCEP HAS SOME ISOLATED CONVECTION ACROSS THE NORTHERN TWO TIERS
OF COUNTIES AND THE NSSL 4.0KM WRF IS SIMILAR. LATEST HRRR (17Z RUN)
IS MORE BULLISH IN BREAKING OUT CONVECTION THIS AFTERNOON INTO THE
EVENING AND SEEMS MORE WIDESPREAD THAN ANY OTHER MODEL. LEANED
TOWARD A BLEND OF THE NAM12/SREF WITH TIMING AND PLACEMENT OF
CONVECTION OVER NORTHERN IOWA PAST 03Z TUESDAY. WITH THE VERY DRY
AIR MASS IN THE LOWER LEVELS AND BUFR SOUNDINGS INDICATIVE OF MAINLY
WIND THREAT AS THEY MIX UP TO AROUND 850-700MB DEPENDING ON WHICH
MODEL...CANNOT RULE AN ISOLATED SEVERE POTENTIAL TONIGHT ACROSS
NORTHERN IOWA. EFFECTIVE SHEAR AROUND 35-40KTS BUT THERE IS
LITTLE...IF ANY...LOW LEVEL SHEAR WITH 0-1KM AND 0-3KM SHEAR LESS
THAN 15KTS AND 30KTS RESPECTIVELY. THERE IS PLENTY OF INSTABILITY
PRESENT BUT WITH SUCH A STRONG CAP IN PLACE...IT WILL TAKE SOME TIME
FOR IT ERODE. WITH THE UPPER LEVEL VORT MAX TIMING TO MOVE INTO
NORTHERN IOWA AFTER 03Z...HAVE HIGHEST POPS B/T 06-12Z TUESDAY.
.LONG TERM /TUESDAY THROUGH MONDAY/...
THERE IS LITTLE CHANGE NEEDED TO THE GOING FORECAST. IT WILL REMAIN
HOT THROUGH WEDNESDAY WITH CHANCES FOR SHOWERS/THUNDERSTORMS ACROSS
THE NORTHEAST AND EAST. SOUNDING ARE SHOWING SOME DRY AIR ALOFT AND
A CLASSIC INVERTED V SO THERE IS SOME POTENTIAL FOR STRONG/DAMAGING
WIND WITH THESE STORMS AND THAT IS COVERED IN VARIOUS OUTLOOKS. THE
MODELS ARE A LITTLE SLOWER IN BRINGING THE FRONT THROUGH SO
WEDNESDAY HIGHS MAY NEED TO BE BROUGHT UP BUT I WOULD LIKE TO SEE
WHAT CLOUDS/CONVECTIVE TRENDS WILL DO BEFORE RAISING THEM MORE THAN
I HAVE DONE. SOMETHING ELSE OF NOTE THAT MAY BE A CAVEAT TO THE
SEVERE POTENTIAL IS THAT THE MODELS HAD BEEN ADVERTISING A VORT MAX
TO DROP DOWN THE RIDGE ACROSS THE EAT/NORTHEAST AND NOW THEY ARE
TAKING THAT VORT MAX EAST AND NOT DROPPING IT SOUTH. QPF IS ALSO
LESS NOW FOR THE AREA WHICH IS NOT A SURPRISE REALLY. OTHER THINGS
OF NOTE IS THAT A SHORTWAVE THAT WAS PROGGED FOR SATURDAY NIGHT IS
NOW COMING THROUGH ON SUNDAY. THIS IS ADVERTISED BY BOTH THE GFS
AND EURO SO I LEFT SATURDAY DRY AND INCREASED POPS ON SUNDAY. TEMPS
WILL STILL BE SEASONAL BUT COMPARED TO WHAT WE HAVE THE TERM
"COOLER" CAN BE APPLIED HERE AND IT WILL IN DEED FEEL THAT WAY.
HIGHS FOR THE WEEKEND WILL BE IN THE LOWER TO MID 80S WITH MAYBE
SOME 90S ACROSS THE FAR SOUTHWEST.
THE COOLER TEMPS DO NOT APPEAR TO BE STAYING AS WAS ELUDED TO
YESTERDAY...THE MODELS REBUILD THE RIDGE OVER THE ROCKIES AND TRENDS
ARE TO BRING THE UPPER RIDGE BACK INTO THE MIDWEST. THIS WILL OCCUR
BEYOND THE EXTENDED PERIOD SO JUST HOW MUCH HEAT WE WILL SEE IS
STILL GOING TO NEED TO BE EVALUATED. WE WILL AT LEAST SEE A SEVERAL
DAY BREAK FROM THE OPPRESSIVE HEAT LATER THIS WEEK.
&&
.AVIATION...24/00Z
STILL DOES NOT APPEAR LIKELY THAT MINNESOTA THUNDERSTORMS WILL
AFFECT IOWA...BUT THERE MAY BE SOME VERY HIGH BASED SHOWERS OR
THUNDER THAT BRUSH BY KMCW LATE TONIGHT. OTHERWISE EXPECTING VFR
CONDITIONS THROUGHOUT THE TAF FORECAST. SURFACE BOUNDARY HAS SAGGED
SOUTH OF KMCW/KALO FOR THE OVERNIGHT...POSSIBLY REINFORCED BY
OUTFLOW FROM STORMS FAR TO THE NORTH. IT WILL RETURN DURING THE DAY
TUESDAY WITH SOUTH FLOW.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
EXCESSIVE HEAT WARNING UNTIL 7 PM CDT WEDNESDAY FOR ADAIR-ADAMS-
APPANOOSE-AUDUBON-BOONE-CALHOUN-CARROLL-CASS-CLARKE-CRAWFORD-
DALLAS-DAVIS-DECATUR-GREENE-GUTHRIE-HAMILTON-JASPER-LUCAS-
MADISON-MAHASKA-MARION-MONROE-POLK-RINGGOLD-SAC-STORY-TAYLOR-
UNION-WAPELLO-WARREN-WAYNE-WEBSTER.
HEAT ADVISORY UNTIL 7 PM CDT WEDNESDAY FOR BLACK HAWK-BREMER-
BUTLER-FRANKLIN-GRUNDY-HARDIN-HUMBOLDT-MARSHALL-POCAHONTAS-POWESHIEK-
TAMA-WRIGHT.
&&
$$
UPDATE...JUNGBLUTH
LONG TERM...FAB
SHORT TERM...PODRAZIK
AVIATION...JUNGBLUTH
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
413 AM CDT TUE JUL 24 2012
...UPDATED SHORT TERM AND LONG TERM SECTIONS...
.SYNOPSIS...
ISSUED AT 112 AM CDT TUE JUL 24 2012
A FAIRLY IMPRESSIVE UPPER LOW BY MID-SUMMER STANDARDS WAS CENTERED
OVER SOUTHERN ALBERTA AS OF 24.05Z WITH A COMPACT 70-80 KNOT JET
STREAK ON THE SOUTHEAST SIDE OF THE LOW AT 400MB (PER RAP ANALYSIS).
THERE WAS ANOTHER DEPARTING MID-UPPER LEVEL TROUGH ACROSS
SOUTHEASTERN CANADA TO THE NORTHERN GREAT LAKES REGION. IN THE
LOWER TROPOSPHERE...A FRONT WAS EVIDENT IN THE 850MB ANALYSIS
EXTENDING FROM LOWER MICHIGAN TO SOUTHERN MINNESOTA. THE FRONT
CONTINUED WEST TOWARD JUST SOUTH OF THE BLACK HILLS REGION WHICH
COULD BE FOLLOWED BACK NORTHWEST INTO CENTRAL/EASTERN MONTANA.
FAIRLY STRONG COLD FRONTOGENESIS WAS BECOMING INCREASINGLY EVIDENT
ACROSS WESTERN MONTANA WITH 850MB TEMPERATURES BEHIND THE COLD FRONT
IN WASHINGTON STATE FROM +6 TO +11C. THE HOTTEST TEMPERATURES AT
850MB WERE FOUND ALONG A LINE FROM ROUGHLY THE NEBRASKA PANHANDLE TO
SOUTHEASTERN SOUTH DAKOTA WHERE TEMPS RANGED FROM +30 TO +33C ALONG
THIS AXIS. WITHIN THIS HEAT AXIS...VALENTINE NEBRASKA REACHED A HIGH
TEMPERATURE OF 109F.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 406 AM CDT TUE JUL 24 2012
AS THE STRONG, COMPACT UPPER LOW MOVES EAST ACROSS THE CANADIAN
PRAIRIES TODAY...THE COLD FRONT TIED TO THIS UPPER FEATURE WILL MOVE
SOUTH DOWN THE NORTHERN HIGH PLAINS TODAY AND TONIGHT. AS THIS IS
HAPPENING...THE LEE TROUGH OVER EASTERN COLORADO WILL FURTHER
DEEPEN AS WELL RESULTING IN INCREASED PRESSURE GRADIENT AND STRONGER
SURFACE WINDS. 18 TO 22 KT SURFACE WINDS ARE FORECAST ACROSS
SOUTHWEST KANSAS FROM THE SOUTH-SOUTHWEST. HIGHS WILL BE SIMILAR TO
THAT OF THE PAST FEW DAYS...WITH WARMEST TEMPERATURES FARTHER NORTH
WHERE THE LOW LEVEL THERMAL NOSE WILL ADVANCE FARTHER EAST IN
NORTHWEST KANSAS SUPPORTING 105 TO 107 DEGREE LATE AFTERNOON
TEMPERATURES. ELSEWHERE SOUTH OF A SCOTT CITY TO HAYS LINE HIGHS
WILL RANGE FROM 100 TO 103F. TONIGHT...THE PRESSURE GRADIENT WILL
STILL BE STRONG ENOUGH TO KEEP WINDS UP IN THE 10-15 KNOT RANGE
THROUGH THE NIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 406 AM CDT TUE JUL 24 2012
MEDIUM RANGE MODELS INDICATE AN UPPER LEVEL SHORTWAVE TROUGH OF LOW
PRESSURE EJECTING EASTWARD OUT OF THE CENTRAL AND SOUTHERN ROCKIES
INTO THE WESTERN HIGH PLAINS WEDNESDAY BRINGING A MUCH NEEDED CHANCE
FOR PRECIP TO PORTIONS OF WESTERN KANSAS. AN ATTENDANT COLD FRONT IS
PROJECTED TO PUSH SOUTHEAST INTO WESTERN KANSAS SOMETIME BY EARLY TO
MID AFTERNOON WEDNESDAY SETTING THE STAGE FOR POSSIBLE SHOWER AND
THUNDERSTORM DEVELOPMENT. AS THE FRONT BEGINS TO PUSH INTO THE STATE,
THE NAM, GEM, GFS, AND ECMWF POINT TO A SURFACE LOW DEVELOPING ALONG
THE FRONT, GENERALLY ACROSS SOUTHWEST KANSAS. THIS WILL INCREASE LOW
LEVEL FORCING, PARTICULARLY TO THE NORTH AND EAST OF THE SURFACE LOW
ALONG THE BOUNDARY ITSELF. AMPLE MOISTURE WILL BE ON HAND AS A
PREVAILING LOW LEVEL SOUTHERLY FLOW IS EXPECTED TO DRIVE IT NORTH
WITH H85 DEWPOINTS JUST ABOVE 10C ACROSS MUCH OF CENTRAL AND WESTERN
KANSAS. ADDITIONALLY, NAM AND GFS MODEL SOUNDINGS DO POINT TO PLENTY
OF AVAILABLE MID/UPPER LEVEL INSTABILITY BY WEDNESDAY AFTERNOON WITH
CAPE VALUES IN EXCESS OF 1500 TO 2000 J/KG. HOWEVER, A COUPLE OF
FACTORS MAY LIMIT CONVECTION ACROSS WESTERN KANSAS AS THE FRONTAL
BOUNDARY BEGINS TO PUSH INTO THE AREA. FIRST WILL BE AN EXPECTED
WEAK FLOW ALOFT AS ALL MODELS KEEP THE UPPER LEVEL JET JUST OFF TO
OUR NORTH ACROSS THE NORTHERN PLAINS. CAPPING COULD ALSO PLAY A
LIMITING FACTOR AS A HOT AFTERNOON THE PREVIOUS DAY WILL HAVE HIGH
TEMPERATURES UP NEAR TO JUST ABOVE 100F.
BECAUSE OF THE WEAK FLOW ALOFT AND THE LIKELY LOCATION OF THE
DEVELOPING SURFACE LOW, WILL KEEP 30 POPS IN ACROSS MUCH OF THE AREA
WITH 40 POPS FURTHER NORTHEAST IN CENTRAL KANSAS, ALONG WHERE THE
BOUNDARY IS EXPECTED TO BE LATE WEDNESDAY. ANY DEVELOPING STORMS ARE
ALSO EXPECTED TO BE ELEVATED WITH STRONG OUTFLOW WINDS THE PRIMARY
THREAT. DRIER CONDITIONS ARE EXPECTED THROUGH THE REMAINDER OF THE
PERIOD AS UPPER LEVEL RIDGING REDEVELOPS ACROSS THE INTERMOUNTAIN
WEST BY THURSDAY AND PUSHES SLOWLY EAST INTO THE WESTERN HIGH PLAINS
THROUGH THE WEEKEND.
TEMPERATURES ARE EXPECTED TO BE ABOVE NORMAL WEDNESDAY EVEN AS THE
COLD FRONT BEGINS TO PUSH SOUTHEAST INTO WESTERN KANSAS BY MID DAY.
AHEAD OF THE COLD FRONT, THE NAM, GFS, AND ECMWF SHOW H85
TEMPERATURES RANGING FROM THE UPPER 20S(C) ACROSS CENTRAL KANSAS
TO JUST ABOVE 30C ACROSS MUCH OF SOUTHWEST KANSAS. CONSIDERING HOW
SLOW THE MODELS HAVE THE FRONT PROJECTED TO MOVE THROUGH THE AREA,
LOOK FOR HIGHS ABOVE 100F ACROSS CENTRAL AND MUCH OF SOUTHWEST
KANSAS AGAIN WEDNESDAY AFTERNOON. HOWEVER, A BRIEF REPRIEVE FROM
TRIPLE DIGIT HIGHS IS LIKELY THURSDAY IN WAKE OF THE SLOW MOVING
COLD FRONT. A NORTH TO NORTHEAST LOW LEVEL FLOW INTO WESTERN KANSAS
WILL HELP LOWER H85 TEMPERATURES BY JUST A FEW DEGREES. EVEN SO,
EXPECT HIGHS ONLY UP INTO THE 90S(F) THURSDAY AFTERNOON. A GRADUAL
WARMING TREND IS THEN EXPECTED AGAIN AS THE AFOREMENTIONED UPPER
LEVEL RIDGING DEVELOPS ACROSS THE INTERMOUNTAIN WEST BY THURSDAY AND
BEGINS TO PUSH EAST INTO THE WESTERN HIGH PLAINS THROUGH THE WEEKEND.
SHOULD SEE HIGHS CLIMBING BACK TO JUST ABOVE 100F BY THE WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 112 AM CDT TUE JUL 24 2012
A LEESIDE TROUGH WILL CONTINUE TO STRENGTHEN ACROSS EASTERN COLORADO
ON TUESDAY WHICH WILL SUPPORT STRONGER SURFACE WINDS. WINDS ARE
EXPECTED TO RANGE FROM 18 TO 22 KNOTS DURING THE MIDDAY TO EARLY
EVENING HOURS WITH SOME GUSTS APPROACHING 30 KNOTS AT TIMES. THIS
WILL BE THE MAIN AVIATION WEATHER HIGHLIGHT AS SKIES WILL CONTINUE
TO BE CLEAR TO MOSTLY CLEAR WITH VFR CATEGORY PREVAILING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 101 73 103 69 / 10 10 20 30
GCK 104 70 102 68 / 10 10 30 30
EHA 99 70 98 66 / 20 20 30 30
LBL 100 72 102 69 / 20 20 30 30
HYS 106 73 104 69 / 0 10 30 40
P28 102 75 104 72 / 10 10 10 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...UMSCHEID
SHORT TERM...UMSCHEID
LONG TERM...JJOHNSON
AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
113 AM CDT TUE JUL 24 2012
...UPDATED SYNOPSIS AND AVIATION SECTION FOR 06Z TAFS...
.SYNOPSIS...
ISSUED AT 112 AM CDT TUE JUL 24 2012
A FAIRLY IMPRESSIVE UPPER LOW BY MID-SUMMER STANDARDS WAS CENTERED
OVER SOUTHERN ALBERTA AS OF 24.05Z WITH A COMPACT 70-80 KNOT JET
STREAK ON THE SOUTHEAST SIDE OF THE LOW AT 400MB (PER RAP ANALYSIS).
THERE WAS ANOTHER DEPARTING MID-UPPER LEVEL TROUGH ACROSS
SOUTHEASTERN CANADA TO THE NORTHERN GREAT LAKES REGION. IN THE
LOWER TROPOSPHERE...A FRONT WAS EVIDENT IN THE 850MB ANALYSIS
EXTENDING FROM LOWER MICHIGAN TO SOUTHERN MINNESOTA. THE FRONT
CONTINUED WEST TOWARD JUST SOUTH OF THE BLACK HILLS REGION WHICH
COULD BE FOLLOWED BACK NORTHWEST INTO CENTRAL/EASTERN MONTANA.
FAIRLY STRONG COLD FRONTOGENESIS WAS BECOMING INCREASINGLY EVIDENT
ACROSS WESTERN MONTANA WITH 850MB TEMPERATURES BEHIND THE COLD FRONT
IN WASHINGTON STATE FROM +6 TO +11C. THE HOTTEST TEMPERATURES AT
850MB WERE FOUND ALONG A LINE FROM ROUGHLY THE NEBRASKA PANHANDLE TO
SOUTHEASTERN SOUTH DAKOTA WHERE TEMPS RANGED FROM +30 TO +33C ALONG
THIS AXIS. WITHIN THIS HEAT AXIS...VALENTINE NEBRASKA REACHED A HIGH
TEMPERATURE OF 109F.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 329 PM CDT MON JUL 23 2012
OVER THE NEXT 24-36 HOURS, THE UPPER LEVEL RIDGE AXIS THAT HAS
PERSISTED OVER THE CENTRAL PLAINS WILL START TO WEAKEN IN RESPONSE
TO THE AFOREMENTIONED UPPER-LEVEL TROUGHING PROGRESSING ACROSS THE
NORTHERN PLAINS, WITH 500MB HEIGHTS DROPPING SEVERAL DECAMETERS.
HOWEVER, SEA LEVEL PRESSURE VALUES ARE PROGGED TO FALL ACROSS THE
HIGH PLAINS OF EASTERN COLORADO BY TUESDAY AS THE WEAK BOUNDARY OR
WARM FRONT MOVES NORTHWARD INTO SOUTHWEST KANSAS IN RESPONSE TO THE
UPPER LEVEL SYSTEMS. SO DESPITE THE 500MB HEIGHT FALLS, THE SURFACE
PRESSURES AND 1000MB HEIGHTS WILL ALSO BE FALLING, RESULTING IN
SIMILAR THICKNESS PATTERNS AND A CONTINUATION OF HOT TEMPERATURES.
THE ECMWF SHOWS VEERED 850MB WINDS LATE TONIGHT, PROVIDING A BURST
OF DOWNSLOPE FLOW THAT WILL MIX DOWN TO THE SURFACE WITH DAYTIME
HEATING. THUS, IT SHOULD BE A FEW DEGREES WARMER TOMORROW AS THE
WARM FRONT PASSES SINCE THE WINDS WILL BE MORE SOUTHERLY WITH NO
UPSLOPE COMPONENT, AND SINCE MIXING WILL BE STRONGER AND DEEPER.
UNTIL THEN, TONIGHT`S LOWS WILL BE SLIGHTLY HIGHER THAN LAST
NIGHT`S SINCE SURFACE WINDS ARE EXPECTED TO INCREASE BY 09-12Z AS
THE SURFACE BOUNDARY APPROACHES. VERY SMALL CHANCES FOR
THUNDERSTORMS WERE INTRODUCED FOR FAR SOUTHWEST KANSAS FOR
TUESDAY AFTERNOON BASED ON WHAT IS OCCURRING THIS AFTERNOON IN
WEST TEXAS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 347 PM CDT MON JUL 23 2012
A NORTHERN BRANCH SHORTWAVE TROUGH MOVES ACROSS THE NORTHERN AND
CENTRAL PLAINS ON WEDNESDAY. THIS WAVE WILL PUSH A WEAK COLD FRONT
ACROSS WESTERN KANSAS ON WEDNESDAY AND WEDNESDAY NIGHT. WILL
MAINTAIN A 30 POP FOR THUNDERSTORMS WITH THE FRONT. FORECAST CAPES
ARE AROUND 1000 J/KG HOWEVER UPPER LEVEL WINDS WILL BE WEAK. SURFACE
MOISTURE CONVERGENCE ALONG THE FRONT WILL BE THE MAIN SOURCE OF
LIFT. A FEW STORMS COULD HAVE SMALL HAIL AND STRONG WINDS, BUT
SEVERE THUNDERSTORMS ARE NOT ANTICIPATED. TEMPERATURES WILL BE HOT
AHEAD OF THE FRONT WITH 100 TO 105 DEGREES. COOLER TEMPS IN THE MID
90S ARE EXPECTED BEHIND THE FRONT ON THURSDAY. BY FRIDAY AND INTO
SATURDAY THE HOT UPPER LEVEL RIDGE REBUILDS INTO THE CENTRAL PLAINS
WITH 500MB HEIGHTS BACK TO 595 DECAMETERS. THIS WILL PUSH TEMPS BACK
TO AROUND THE CENTURY MARK. ON SUNDAY AND MONDAY ANOTHER NORTHERN
BRANCH WAVE IS FORECAST TO TOP THE RIDGE AND BRING DOWN ANOTHER
FRONTAL BOUNDARY. OVERNIGHT LOWS WILL BE MILD THROUGH THIS LONG TERM
PERIOD FROM THE UPPER 60S TO LOW TO MID 70S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 112 AM CDT TUE JUL 24 2012
A LEESIDE TROUGH WILL CONTINUE TO STRENGTHEN ACROSS EASTERN COLORADO
ON TUESDAY WHICH WILL SUPPORT STRONGER SURFACE WINDS. WINDS ARE
EXPECTED TO RANGE FROM 18 TO 22 KNOTS DURING THE MIDDAY TO EARLY
EVENING HOURS WITH SOME GUSTS APPROACHING 30 KNOTS AT TIMES. THIS
WILL BE THE MAIN AVIATION WEATHER HIGHLIGHT AS SKIES WILL CONTINUE
TO BE CLEAR TO MOSTLY CLEAR WITH VFR CATEGORY PREVAILING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 104 73 103 72 / 10 10 20 30
GCK 104 70 102 71 / 10 10 30 30
EHA 101 70 98 69 / 20 20 30 30
LBL 103 72 102 72 / 20 20 20 30
HYS 106 73 104 72 / 0 10 30 40
P28 104 75 104 75 / 10 10 10 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...UMSCHEID
SHORT TERM...FINCH
LONG TERM...KRUSE
AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS JACKSON KY
150 AM EDT TUE JUL 24 2012
.UPDATE...
ISSUED AT 150 AM EDT TUE JUL 24 2012
WITH 06Z TAFS...HAVE UPDATED SKY CONDITION GRIDS BASED ON 00Z MODEL
RUNS.
UPDATE ISSUED AT 810 PM EDT MON JUL 23 2012
RAN ANOTHER UPDATE TO KEEP THE GRIDS IN CHECK WITH THE CURRENT
CONDITIONS AND TRENDS. THE ATMOSPHERE REMAINS UNSTABLE...BUT ANY
TRIGGERS FOR ARE LACKING. WILL BE WATCHING FOR ANY DEVELOPMENT WITH
THE CONVECTION TRYING TO POP UP OVER SOUTHEAST INDIANA...BUT
INSTABILITY OVER EAST KENTUCKY WILL BE DIMINISHING THROUGH THE
EVENING AND OVERNIGHT. ACCORDINGLY...WILL KEEP POPS LOW THROUGH THE
NIGHT...BUT NOT COMPLETELY ZEROED OUT. ALSO ADDED A TOUCH OF DEEPER
VALLEY FOG TO THE GRIDS. UPDATES TO NDFD...THE WEB AND ZONES WILL BE
ISSUED SHORTLY.
UPDATE ISSUED AT 545 PM EDT MON JUL 23 2012
DID A QUICK UPDATE TO THE GRIDS AND WEB FORECAST TO ACCOUNT FOR
CONVECTIVE TRENDS...OR LACK THERE OF...INTO THE EVENING. ALSO UPDATED
THE SKY...TEMPERATURE AND DEW POINT GRIDS FOR THEIR CURRENT
OBSERVATIONS AND TRENDS. UPDATES SENT TO THE WEB AND NDFD...THE
ZONES ARE STILL FINE.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 313 PM EDT MON JUL 23 2012
HIGH PRESSURE RIDGE CONTINUES TO DOMINATE TO OUR WEST AND
SOUTH...WITH EASTERN KENTUCKY SITTING ON THE PERIPHERALS. THIS
MEANS...OUR AREA REMAINS A FOCUS OF CONCERN FOR REPEATED CHANCES FOR
SHOWERS AND THUNDERSTORMS OVER THE NEXT 24 TO 48 HOURS. A FEW
ISOLATED SHOWERS HANGING ON NEAR THE VIRGINIA BORDER THIS
AFTERNOON...BUT THESE SHOULD EXIT INTO VIRGINIA IN THE NEXT HOUR OR
SO. A LULL IS EXPECTED INTO THIS EVENING. HOWEVER...A SHORTWAVE
TROUGH IS PUSHING INTO SOUTHERN OHIO AND INDIANA. PRESENTLY...NOT MUCH
ACTIVITY ASSOCIATED WITH THIS FEATURE. IN FACT...THE SHOWER ACTIVITY
EARLIER HAS ALMOST COMPLETELY DRIED UP. STILL SOME QUESTION ON HOW
MUCH DEVELOPMENT WILL OCCUR AS THIS TROUGH AXIS PUSHES SOUTH INTO
A MORE UNSTABLE AIR MASS. IT IS POSSIBLE WE COULD SEE A FEW ISOLATED
SUPERCELLS CAPABLE OF DAMAGING WINDS THROUGH 9 OR 10 PM. THE HRRR HAS
HELD CONSISTENT WITH THE IDEA OF ISOLATED SUPERCELLS DEVELOPING AFTER
8 PM...AND TRACKING INTO AREAS NORTH OF I-64 AROUND 9 OR 10 PM. THERE
IS SOME WEAK DIRECTIONAL SHEAR TO SUPPORT THIS IDEA. THUS...PLAN TO
INCLUDE A SLIGHT CHANCE OF SHOWERS AND STORMS THROUGH LATE EVENING.
THIS ACTIVITY WILL GRADUALLY WEAKEN AS IT PUSHES FURTHER SOUTH...SO
THE SECOND HALF OF THE NIGHT SHOULD BE MAINLY DRY.
MOVING ON TO TOMORROW...IT LOOKS LIKE ANOTHER DECENT WAVE WILL DROP
SOUTHEAST FROM MIDDAY INTO THE EVENING HOURS...PRODUCING AN EVEN
BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS. WIND SHEAR WILL BE EVEN
BETTER TOMORROW WITH 700MB WINDS AROUND 30 KNOTS AND 500MB WINDS 35
KNOTS. THERE IS SOME DIRECTIONAL SHEAR AS WELL. THUS...SEVERE THREAT
LOOKS PRETTY GOOD TOMORROW FOR SOME DAMAGING WINDS. THE BIGGER
CONCERN COULD BE SOME LOCALLY HEAVY RAIN WITH PW VALUES AROUND 2
INCHES AND FREEZING LEVELS OVER 15KFT. ANY STORMS THAT HIT THE SAME
AREAS COULD LEAD TO FLASH FLOODING. NOT CONFIDENT ENOUGH TO GO WITH A
WATCH...BUT CERTAINLY SOMETHING TO KEEP AN EYE ON.
BY TOMORROW NIGHT...THE FIRST ROUND OF CONVECTION WILL DEPART...BUT
WE WILL REMAIN IN A FAVORABLE SPOT FOR MORE DEVELOPMENT
UPSTREAM...WITH PERHAPS A NOCTURNAL MCS DEVELOPING AND TRACKING INTO
OUR AREA. THUS...WILL KEEP SOME CHANCE POPS GOING THROUGH TOMORROW
NIGHT.
TEMPERATURES WILL REMAIN MILD WITH HIGHS ON TUESDAY CLIMBING TO
AROUND 90 AND LOWS TONIGHT AND TOMORROW NIGHT IN THE LOWER 70S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 341 PM EDT MON JUL 23 2012
THE MODELS START OUT IN VERY GOOD AGREEMENT WITH A FAIRLY ZONAL FLOW
NORTH OF 40 DEGREES AND UPPER RIDGING DOMINATES SOUTH OF 40 DEGREES.
THE SYSTEM TO WATCH IS AN UPPER LOW IN SOUTHWEST MANITOBA WITH A
TROUGH EXTENDING INTO THE CENTRAL PLAINS. THIS UPPER LOW STARTS
MOVING SLOWLY TO THE EAST SOUTHEAST AND AS IT DOES...IT IS PUSHING
THE POLAR FRONT TO THE SOUTH. THE TROUGH CONTINUE PUSHING TO THE ESE
AND WILL PUSH A FRONT ACROSS THE COAL FIELDS ON FRIDAY. THIS FRONT
WILL STAY JUST SOUTH OF THE AREA AND WILL PUSH BACK INTO THE AREA ON
SUNDAY NIGHT. THE DIFFERENCE IN SHORT WAVE TIMING INCREASES WITH
TIME...HOWEVER THE GENERAL PATTERN TRANSITION IS IN PRETTY GOOD
AGREEMENT. THE SEQUENCING HAS HIGH CONFIDENCE...HOWEVER THE TIMING
OF THE SHORT WAVES DECREASES CONFIDENCE IN WITH TIME. FOR
TEMPS...NUDGED THE FORECAST TOWARD THE MODEL BLEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 150 AM EDT TUE JUL 24 2012
FOG LIMITED TO THE DEEPER VALLEYS IS POSSIBLE DURING THE LATE NIGHT
AND EARLY MORNING. OTHERWISE...VFR IS ANTICIPATED INTO THE AFTERNOON.
WILL EXPECT THUNDERSTORMS...ESPECIALLY FOR THE NE PART OF THE
FORECAST AREA...BETWEEN ABOUT 17Z AND 23Z...WITH A POTENTIAL FOR
BRIEF IFR. QUIET WX IS THEN EXPECTED TO FINISH THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...KAS
LONG TERM....JJ
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
225 AM EDT TUE JUL 24 2012
.SYNOPSIS...
A SERIES OF UPPER LEVEL DISTURBANCES WILL CROSS THE MID ATLANTIC
REGION THROUGH TUESDAY NIGHT...PRODUCING SCATTERED THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1015 PM MONDAY...
AN UPPER LEVEL WAVE ALONG WITH MERGING OUTFLOWS HELPED TO PRODUCE A
BROKEN LINE OF CONVECTION THAT WAS RESPONSIBLE FOR SEVERAL SEVERE
STORMS THIS EVENING...WHICH HAS NOW PUSHED EAST OF THE CWA.
ADDITIONAL SHOWERS AND THUNDERSTORMS WERE MOVING OFF OF THE HIGHER
TERRAIN OF VIRGINIA AROUND SUNSET BUT HAVE SINCE DISSIPATED WITH
STABILIZATION AND SUBSIDENCE IN THE WAKE OF THE UPPER WAVE. WATER
VAPOR IMAGERY LOOKS TO BE VOID OF ANY ADDITIONAL UPPER LEVEL
DISTURBANCES FOR THE OVERNIGHT PERIOD...SO THERE SHOULD NOT BE
MORE THAN AN ISOLATED SHOWER OR THUNDERSTORM OR TWO ON A REMNANT
OUTFLOW...MAINLY PRIOR TO 06Z. SOME CLEARING IS EVIDENT OVER
VIRGINIA ON INFRA RED IMAGERY... AND RAP RH CROSS SECTIONS SUGGEST
ENOUGH NEAR SURFACE MOISTURE FOR FOG TO DEVELOP. HOWEVER...A LIGHT
SOUTHERLY WIND SHOULD STIR ENOUGH TO KEEP PATCHY FOG LIMITED TO
AREAS WHERE RAIN WAS PARTICULARLY HEAVY...MAINLY SOUTHEAST OF THE
TRIANGLE. STRATUS IS ALSO NOT FORECAST BY THE MODELS BUT IT WOULD
NOT BE SURPRISING TO SEE SOME DEVELOP OVER THE COASTAL PLAIN IN
THE WAKE OF THE RAINFALL. OTHERWISE..THE ONLY CHANGES TO THE
FORECAST WERE TO TRIM LOWS SLIGHTLY ACROSS THE NORTH WHERE SKIES
MAY CLEAR OFF AND DEWPOINTS ARE SLIGHTLY LOWER...70 TO 74 NORTH
TO SOUTH.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 321 PM MONDAY...
TUESDAY AND TUESDAY NIGHT...ANOTHER IN A SERIES OF UPPER LEVEL
DISTURBANCES WILL APPROACH FROM THE NORTHWEST IN THE MORNING AND
AFFECT CENTRAL TUESDAY AFTERNOON AND TUESDAY NIGHT. MID LEVEL
SHEAR A TAD BETTER THAN THIS AFTERNOON WHICH SUGGEST BETTER CHANCE
FOR STRONG/DAMAGING WIND GUSTS WITH THE STRONGEST CONVECTION.
APPEARS TO BE ENOUGH AMPLE TIME IN THE MORNING THROUGH EARLY
AFTERNOON FOR STRONG INSOLATION TO ACHIEVE SURFACE BASED CAPE
VALUES 4000 TO 5000 J/KG AND MIXED LAYER CAPE 2500 TO 3500 J/KG.
INSTABILITY ALOFT SUGGEST POTENTIAL FOR DAMAGING WIND GUSTS AND
MARGINALLY SEVERE HAIL. IN ADDITION...A FEW OF THE STORMS COULD
PRODUCE A LARGE AMOUNT OF LIGHTNING.
WITH LOW LEVEL THICKNESSES COMPARABLE TO TODAY...EXPECT SIMILAR
TEMPERATURES TUESDAY AFTERNOON IN THE MID 90S...THOUGH COULD BE A
TOUCH COOLER IF CLOUDS COME IN SOONER OR THICKER IN THE
NORTHWEST PIEDMONT.
CONVECTION WILL SLOWLY DIMINISH TUESDAY EVENING WITH BULK OF
ACTIVITY AFTER MIDNIGHT EXPECTED OVER THE SOUTHERN COUNTIES THOUGH
APPROACH OF ANOTHER DISTURBANCE IN THE NORTHWEST FLOW MAY SPARK A
FEW SHOWERS IN THE NORTHWEST PIEDMONT AFTER 2 AM. MINIMUM
TEMPERATURES 69 TO 74. -WSS
NORTHWEST MID LEVEL FLOW WILL BE DIRECTED INTO THE AREA ON
WEDNESDAY...WITH PERTURBATIONS IN THE SHEAR AXIS MOVING ACROSS THE
AREA DURING THE DAY. MEANWHILE...WEAK AND COOLER SURFACE HIGH
PRESSURE BUILDS BRIEFLY INTO THE REGION...WITH DRIER NORTHERLY FLOW
EDGING INTO THE NORTHERN TIER. WILL CONTINUE A CHANCE POP GRADUATED
HIGHER SOUTH. LOW LEVEL THICKNESSES SUGGESTS THAT HIGH
TEMPERATURES WILL BE MOSTLY IN THE LOW 90S. DRYING CONTINUES
WITH A TRANSITION TO LOW AMPLITUDE RIDGING WEDNESDAY NIGHT...COULD
ARGUE FOR A LINGERING SLIGHT CHANCE POP ACROSS THE SOUTH AND EAST
EARLY WEDNESDAY NIGHT... NOT ENOUGH CONSISTENCY TO INCLUDE AT THIS
POINT. MINIMUM TEMPERATURES WILL BE PERSISTENCE...70 TO 75. -MLM
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 100 PM MONDAY...
THE INITIAL EXTENDED FORECAST STARTS OUT THURSDAY WITH A FAMILIAR
PATTERN...SURFACE LEE TROUGH OVER CENTRAL NORTH CAROLINA AND WESTERLY FLOW
ALOFT. THE RESULTING HIGH INSTABILITY (HIGHS 92 TO 96) BUT LACK
OF FORCING MECHANISMS ARE CONDUCIVE TO WIDELY SCATTERED DIURNAL
CONVECTION... WITH SLIGHT NODS FOR HIGHER POPS IN THE WEST WHERE
DIFFERENTIAL HEATING AND EASTWARD DRIFT OF SUBSEQUENT
CONVECTION... AND SEA BREEZE PENETRATION INTO THE COASTAL PLAIN.
A FRONT SAGGING SOUTH LATER FRIDAY OR FRIDAY NIGHT WILL PROVIDE SOME
ENHANCED LOW LEVEL CONVERGENCE W/ENHANCED CONVECTIVE CHANCES AS IT
WILL BE ACCOMPANIED BY SHARPENING OF AN UPPER TROUGH OVER THE EASTERN
CONUS. WILL CONTINUE CHANCE POPS FRIDAY AND SLIGHT CHANCES FRIDAY
NIGHT WITH FRONTAL PASSAGE CURRENTLY FORECAST FRIDAY NIGHT...
WHICH WOULD BE LEAST FAVORABLE STABILITY WISE. HIGHS FRIDAY WILL
REACH THE LOW TO MID 90S.
UPPER TROUGH WILL BE IN PLACE SATURDAY AND MIGRATING SLOWLY EAST
THROUGH MONDAY...WITH ATTENDANT NORTHWEST FLOW. TEMPERATURES WILL BE
SEASONABLE... LOW 90S AFTER MORNING LOWS 70 TO 75. CONVECTION
WILL BE MAINLY DRIVEN BY SMALLER SCALE PERTURBATIONS IN THE MID
LEVEL FLOW... WHICH OF COURSE ARE NOT FORECASTABLE THIS EARLY IN
THE GAME.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 220 AM...
ONLY VERY LOCALIZED MVFR FOG THIS MORNING. AN ISOLATED THUNDERSTORM
POSSIBLE THROUGH THE MORNING. EXPECTING THUNDERSTORMS TO DROP OUT
OF VIRGINIA THIS AFTERNOON AND SWEEP ACROSS CENTRAL NORTH
CAROLINA... EXITING AFTER MIDNIGHT. SOUTHWEST TO WEST WIND 10 TO
12 MPH BY MID MORNING... CONTINUING INTO LATE AFTERNOON.
MOSTLY MVFR FOG DEVELOPING LATE TONIGHT AS WINDS SUBSIDE. THEN A
DAILY THREAT FOR ISOLATED TO SCATTERED CONVECTION IN THE
AFTERNOON AND EVENING HOURS WITH ASSOCIATED MVFR CEILINGS AND
VISIBILITY. THERE WILL BE POCKETS OF MVFR TO IFR FOG AND STRATUS
BETWEEN 5 AM AND 9 AM EACH MORNING.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
NEAR TERM...SMITH/WSS
SHORT TERM...SMITH/WSS
LONG TERM...MLM
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
146 AM EDT TUE JUL 24 2012
.SYNOPSIS...
A COLD FRONT WILL PUSH SOUTH INTO THE OHIO VALLEY ON TUESDAY. THIS
FRONT WILL WEAKEN AND THEN LIFT NORTHWARD AS A WARM FRONT ON
WEDNESDAY. IN THE WEAK WESTERLY FLOW ALOFT...A SURFACE LOW WILL
DEVELOP OVER THE GREAT LAKES AND SLOWLY MOVE EAST...PUSHING A COLD
FRONT THROUGH THE OHIO VALLEY THURSDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
CONDITIONS ARE QUIESCENT ACROSS THE REGION THIS EVENING AND SHOULD
REMAIN THAT WAY INTO THE LATE NIGHT. LARGE AREA OF MID CLOUDS WILL
SPREAD SOUTHEAST ACROSS THE REGION. THESE CLOUDS ALONG WITH SOUTH
SOUTHWEST WINDS STAYING UP WILL RESULT IN RATHER WARM LOWS. HAVE
BUMPED THEM UP SLIGHTLY.
BIG QUESTION IS WHETHER SHOWERS AND THUNDERSTORMS WILL DEVELOP
LATE TONIGHT AND MOVE INTO THE REGION BEFORE DAYBREAK. LOOKS LIKE
THE 00Z NAM IS DELAYING THIS PRECIPITATION UNTIL TUESDAY. BUT
SEVERAL RUNS OF THE HRRR ALONG WITH SEVERAL 18Z SYNOPTIC MODELS
ARE BRINGING STORMS INTO THE WESTERN PART OF THE FORECAST AREA.
HAVE TAILORED FORECAST ALONG THESE LINES AND BROUGHT POPS IN FROM
THE NORTHWEST LATE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
STORM DEVELOPMENT SHOULD CONTINUE SOUTHEAST ACROSS THE FORECAST
AREA THROUGH THE DAY AS A FRONT SAGS INTO THE REGION. AS THE
COLD FRONT SAGS INTO KENTUCKY TUESDAY...THERE IS AN INCREASED
CHANCE FOR RAIN RUNNING NORTHWEST TO SOUTHEAST THROUGH NORTHERN
KENTUCKY OVERNIGHT. THE DAYTIME HOURS WILL SEE A BIT MUCH MIXING
THAT THE CHANCE FOR DEVELOPMENT IS DECREASING ON WEDNESDAY AS THE
FRONT LIFTS NORTHWARD AS A WARM FRONT. IT WILL BE EVEN HARDER IN A
WARM ADVECTION PATTERN TO SPARK STORMS OVERNIGHT WEDNESDAY AS THE
NECESSARY FORCING IS NOWHERE TO BE FOUND OVER THE OHIO VALLEY.
WHILE THE MECHANISMS FOR STORMS OVER THE NEXT FEW DAYS APPEAR
LACKING...THE ENVIRONMENT IS SUPPORTIVE OF THEM AND ANY LINGERING
BOUNDARIES OR ONGOING CONVECTION MAY INSTIGATE DEVELOPMENT AS WELL
SO A DRY FORECAST IS NOT PRUDENT.
HIGH TEMPERATURES WITHIN A FEW DEGREES OF 90...COOLEST IN
NORTHEAST CWA AND LOWS IN THE UPPER 60S TO LOWER 70S SEEM
REASONABLE THROUGH MID WEEK.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
MODELS SHOW DESCENT AGREEMENT WITH THE PATTERN OVER THE REGION AT
THE BEGINNING OF THE PERIOD. IN A NW FLOW FROM RIDGING OVER THE
ROCKIES...THEY PLACE A S/W DROPPING ACROSS THE LAKES. THE GFS HAS
MORE ENERGY WITH AN INITIAL WAVE AND IS THEREFORE STRONGER WITH
ITS SURFACE REFLECTION. THE OTHER EXTENDED MODELS ARE MORE MUTED
WITH THIS LOW...SO WILL LEAN TOWARDS THE CONSENSUS. AT THE SFC ON
THURSDAY THE REGION IS WARM SECTORED...SO CANT RULE OUT SOME POP
UP CONVECTION. PUT THE HIGHEST POPS IN THE N CLOSER TO THE S/W
WITH GRADUALLY DECREASING POPS AS YOU HEAD S.
THE MAIN H5 S/W SWINGS ACROSS THE LAKES THU NGT INTO FRI. THIS
PULLS A CDFNT THROUGH THE REGION. EXPECT CONVECTION ALONG THE
FRONT...BUT SINCE FROPA APPEARS TO BE MAINLY THU NGT...ONLY KEPT
POPS IN THE CHC CATEGORY. THE S/W DOESNT SWING THRU UNTIL
FRIDAY...SO THIS SHOULD STALL THE MOVEMENT OF THE FRONT EWD AND
SHOULD KICKOFF ADDITION CONVECTION ON FRIDAY. WENT WITH THE HIGHER
POPS IN THE E ON FRIDAY.
WEAK HIGH PRESSURE BUILDS IN FOR SATURDAY INTO SUNDAY. LOOKS LIKE A
WRMFNT MIGHT BE PUSHED OUT OF THE PLAINS INTO THE REGION FOR
MONDAY...BRINGING ANOTHER CHANCE OF PCPN.
FOR TEMPERATURES...LOOKS LIKE THURSDAY WITH BE THE HOTTEST DAY WITH
THE REGION WARM SECTORED. USED A BLEND OF ECMWF/HPC GUIDANCE...WHICH
PUTS HIGHS ON THU IN THE LOWER TO MID 90S. TEMPERATURES FALL BACK
INTO THE UPPER 80S FRIDAY DUE TO THE CLOUD COVER AND CONVECTION. THE
WEEKEND TEMPERATURES LOOK TO STAY IN THE MID TO UPPER 80S.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
SHORT WAVE ENERGY DROPPING DOWN ACROSS THE WESTERN GREAT LAKES
WILL WORK ITS WAY INTO OUR AREA THROUGH THE MORNING HOURS.
SCATTERED PCPN ASSOCIATED WITH THIS IS MOVING DOWN ACROSS NORTHERN
ILLINOIS AND INTO NORTHERN INDIANA EARLY THIS MORNING. THE MODELS
ARE HAVING A DIFFICULT TIME THOUGH RESOLVING EXACTLY HOW TO HANDLE
THINGS THROUGH THE DAY TODAY. OVERALL...EXPECT TO SEE PCPN BECOME A
BIT MORE WIDESPREAD AS THE LOW LEVEL JET INCREASES SOMEWHAT THROUGH
THE PRE DAWN HOURS. BASED ON THE CURRENT TRAJECTORY...WOULD EXPECT
BEST CHANCE FOR ANY SHOWERS THIS MORNING TO BE AT THE NORTHERN/WESTERN TAF
SITES (KDAY). WE MAY SEE A WEAKENING TREND THOUGH AS THE PCPN APPROACHES
OUR AREA AS WE WILL BEGIN TO GET INTO A DIURNALLY LESS FAVORABLE
TIME PERIOD. WILL THEREFORE GENERALLY JUST COVER PCPN THREAT WITH
A VCSH IN THE TAFS. PCPN CHANCES FOR LATER THIS AFTERNOON ARE
ALSO A BIT UNCERTAIN. WE SHOULD DESTABILIZE NICELY THROUGH THIS
AFTERNOON...ESPECIALLY ALONG AND SOUTH OF A COLD FRONT SAGGING
DOWN TOWARD CENTRAL OHIO. WOULD EXPECT TO SEE THE BEST CHANCE FOR
ANY DEVELOPMENT THIS AFTERNOON ACROSS OUR SOUTHERN AREAS SO WILL
ONLY INCLUDE A VCTS AT KCVG/KLUK FOR NOW.
OUTLOOK...THUNDERSTORMS POSSIBLE WEDNESDAY AND THEN AGAIN THURSDAY
AFTERNOON INTO FRIDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...FRANKS
NEAR TERM...
SHORT TERM...FRANKS
LONG TERM...SITES
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS SPOKANE WA
231 PM PDT Sun Jul 22 2012
.SYNOPSIS...
A strong upper level low will cross the region tonight through
Monday night and result in a chance of thunderstorms for mountain
locations. A few strong storms are possible in the Idaho panhandle
this evening. After the low exits Tuesday, expect a return to dry
and seasonably warm weather for the rest of the week.
&&
.DISCUSSION...
Tonight through Monday: The deep upper level low pressure system is
slowly pushing its way into the Pac NW this afternoon. Water vapor
imagery shows the tightly wound center of the low just southwest
of Vancouver Island with a leading upper level front pushing into
the Cascades. A -24 Celsius cold pool at 500 mbs will accompany
this system as it moves into the Northern Cascades just south of
the Canadian border. This is a fairly anomalous cold pool for mid
July as it is between 2-3 standard deviations colder than what is
average for is time of year and for this region. Models are all in
good agreement moving the center of the low from west to east,
generally right along the Canadian Border. As this system moves
along, we are expecting showers and possibly some thunderstorms to
develop in association with the upper level cold pool in the
northern mountains.
This low is situated at the base of a trough, which is expected to
deepen a bit through this evening. As the trough deepens, we will
see the atmospheric flow pattern become slightly more southerly.
This will allow some monsoonal moisture to ride up northward into
extreme eastern WA and into the Idaho Panhandle. The monsoonal
moisture is reflective of the expansive area of surface convection
and thunderstorms blossoming over southern and central Idaho.
Models have been consistent in showing elevated convection late
this evening into tonight from the northeast Blue Mountains into
the Northern Panhandle and points southeastward. The RUC model
shows increasing 700-850 mb Theta E temperatures across this area,
which is indicative of destabilization of the atmosphere at mid
and upper levels. Dew point temperatures have been falling across
the basin through the afternoon, indicating drier more stable air.
Places like Pullman, Lewiston, Coeur d`Alene and Bonners Ferry
have held on to higher dew points in the low to mid 50s, compared
to dew points in the 40s for places like Moses Lake and Spokane.
This makes me more confident that any convection tonight across
the southeast will not make it much further westward than the
Spokane Area.
Winds will pick up tonight with the passage of the cold front.
Expect these winds to pick up in the Wenatchee Area first in the
early evening hours and then spread eastward into the basin
tonight. winds will be sustained at around 15 to 25 mph with gusts
as high as 25 to 35 mph. Wenatchee could be even slightly more
windy with strong cold air advection through the Cascade gaps this
evening. High temperatures tomorrow will be well below average
with highs expected to be in the 70s for most valley locations.
The northern valleys will have a hard time breaking 70 due to
cloud cover and precipitation. /SVH
Monday night through Wednesday...The next closed upper level low
will slowly track northeast-east and in to Alberta Monday night.
Behind the exiting low the flow will turn northwest. The 00z and
now the 12z models runs are now picking up on another much weaker
low pressure system forming just of Vancouver Island Tuesday, then
deepening as it moves into northwest Washington Tuesday night and
Wednesday. This is a little bit different solution than what we
saw yesterday.
Monday night and Tuesday. As the low kicks out of the region
Monday night moisture will wrap around the low. There isn`t much
in the way of dynamical lift left, save for some orographics. But
there will be some lingering instability and this will support
isolated showers across the northern mountains through the night.
There will be enough instability across north Idaho for an
outside chance of a thunderstorm through the evening hours.
Showers will be on the decrease through the night and Tuesday
morning. Both surface based and ML cape increase through the day
again Tuesday. And while the cape is capped there will be an
opportunity for showers across the northern tier of zones late in
the afternoon. 850 temps increase to 17-18C and with mostly sunny
skies temperatures should show a rebound over the cooler
temperatures from Monday.
Tuesday night and Wednesday the low off Vancouver island begins to
deepen as it moves off the coast. This will swing the upper level
flow back around to the southwest and allow some Pacific moisture
back into the northern mountains. Surface based cape increases to
around 500 J/kg, LI`s -1 to -2 and 700-500 theta e lapse rates
decrease across the north cascades and northern mountains. So
instability is only marginal and there is no decent forcing
mechanism. The models are picking up on a few little waves in the
southwest flow, but these look to be pretty weak. Still, there
will be a chance of surfaced based convection and isolated showers
and a few embedded thunderstorms in the late afternoon.
Temperatures will continue to increase and should be near normal
by Wednesday. /Tobin
Wednesday night through Sunday: A long-wave trough migrates to
the B.C. coast and keeps the Inland Northwest under a dirty ridge,
as weak shortwaves slip in on the southwest flow. This will bring
occasional clouds to the CWA, a lingering threat of mainly
mountains showers and thunderstorms, and warmer temperatures.
Temperatures are expected to warm to average and slightly above
through the period. Guidance shows 850mb temperatures peaking
Thursday and Friday, with a slight cooling trend next weekend
behind the one shortwave, and surface temperatures are forecast to
follow this same trend.
One shortwave, which was coming across the southern Gulf of
Alaska Sunday evening, arrives at the Pacific Northwest coast
Wednesday evening. As the aforementioned long-wave trough migrates
toward the B.C. coast through the end of the work week, the
shortwave is drawn across the CWA. Per the PWAT projections,
moisture pools near the Canadian border and Cascades Wednesday
night through Friday and increases across the southeast CWA
Thursday afternoon and Friday. PWATs rise to between 110-130% of
normal. Models also indicate some low-grade instability. SBCAPE
values between 100-400 J/kg are indicated across the northern
third of the CWA Wednesday evening and again Thursday afternoon
and evening. The passing impulse and upslope flow will help bring
the shower and thunderstorm threat to these areas. Similar SBCAPE
values come into the southeast CWA Thursday afternoon and evening,
from the Blues to Central Panhandle Mountains and will lead to
some shower and thunderstorm threat here too.
By Friday the best moisture and instability retreats into the far
southeast CWA and against the northern Cascades. This leaves the
primary shower potential across northwest Okanogan county, the
Blues, southeast Shoshone county and the Camas Prairie. Guidance
currently indicates CIN values between 100-200 J/kg from the Blues
through the Camas Prairie and southwest Shoshone county, which
would likely inhibit the convection. However there is potential
for showers to develop south of here, where the CIN is weak, and
advect into these areas before falling apart.
Additionally low-end breezy conditions are expected with the
passing wave, especially Friday. At this time, however, relative
humidities and sustained wind speeds are not expected to result in
red flag conditions.
By Saturday the region is under drier, more stable air, lending
to a dry forecast. Then by Sunday another potential shortwave
impulse and injection of monsoonal moisture will return a threat
of showers to the mountains, particularly the far southeast.
Models are not in good agreement with the track and timing of this
potential shortwave, so PoPs are decidedly low. /J. Cote`
&&
.AVIATION...
18z TAFS: A low pressure system will push through a cold front
late this afternoon through this evening. This will result in
increasing westerly winds, beginning with KEAT after 22Z and
spread eastward reaching the Panhandle by 02Z early this evening. We
will likely see some wind gusts up to around 25 to 35 mph through
the evening. We should then lose the gusts as we decouple tonight
with possibly some weak low level wind shear. Winds are expected
to relax a bit by tomorrow morning. Showers and thunderstorms will
remain across the northern mountains this afternoon. Some moisture
moving up from the south may produce some elevated thunderstorms
across the Northeast Blues into the Northern Panhandle by late
this evening. However, there is some question if we will get this
moisture, so confidence is low at this point. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 53 72 54 81 57 85 / 10 10 0 0 0 10
Coeur d`Alene 55 71 52 80 53 83 / 20 10 10 10 10 10
Pullman 49 73 47 79 50 84 / 20 0 0 0 0 0
Lewiston 60 83 56 89 59 92 / 30 0 0 0 0 0
Colville 56 75 52 83 55 86 / 20 30 10 10 10 20
Sandpoint 54 71 49 80 51 83 / 40 30 20 10 10 10
Kellogg 56 69 49 77 53 82 / 40 10 10 10 10 10
Moses Lake 55 79 54 86 57 90 / 10 0 0 0 0 0
Wenatchee 58 80 57 86 61 90 / 10 0 0 0 10 0
Omak 56 77 52 86 57 89 / 30 20 10 10 10 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
339 AM CDT TUE JUL 24 2012
.TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM
DIMINISHING TREND NOTED IN CONVECTION OVER SOUTHWEST WI OVER LAST
HOUR OR SO. SCATTERED TO NUMEROUS CONVECTION EXTENDS WELL TO THE
WEST ACROSS SOUTHERN MN INTO EASTERN SODAK. HOWEVER FRONTAL
BOUNDARY SAGGING ACROSS SOUTHERN WI ATTM...WL CONTINUE INTO NRN IL
EARLY THIS MRNG. THIS WILL TIGHTEN THE BAROCLINICITY ACROSS
SOUTHERN WI AND INCREASE THE LOW LEVEL FN VECTOR RESPONSE TO
FRONTOGENESIS. THIS SHOULD HELP CONTINUE THE SCATTERED TO NUMEROUS
CONVECTION OVER PORTIONS OF SOUTHERN WISCONSIN THROUGH MID-MORNING
BEFORE DIMINISHING. PWAT VALUES IN THE 1.75 TO 2.0 INCH
RANGE...WHICH IS ABOUT 160 PERCENT OF NORMAL. BOTH THE RAP AND
NAM40KM SHOW LAYER FWF LINGERING OVER SOUTH CENTRAL WI TO AROUND 15Z
BEFORE DIMINISHING. HENCE WL CONTINUE LIKELY WORDING IN THE SOUTH
CENTRAL AREAS...DIMINISHING TO CHC/SCT IN THE NORTHEAST.
UPSTREAM SHORT WAVE OVER ERN SODAK IS EXPECTED TO MOVE ESE ACROSS
SRN MN INTO SRN WI LATER THIS MRNG...SO WL CONTINUE CHANCE INTO THE
LATE MORNING. SHORT WAVE AND FRONTOGENETICAL FORCING WEAKENS AND
SLIDES SOUTHEAST FOR THE AFTN.
STRONG SURGE OF RETURN FLOW AND LOW LEVEL THETA-E ADVECTION
ACCOMPANY DEVELOPING LOW LEVEL JET TONIGHT. FOCUS OF LLJ TO THE
NORTHWEST OF CWA...HOWEVER STILL GET CLIPPED BY INCREASING WARM AIR
ADVECTION. HENCE WL CONTINUE LIKELY POPS IN THE NORTH TONIGHT.
.WEDNESDAY AND THURSDAY...FORECAST CONFIDENCE...MEDIUM
CONVECTION NEAR WARM FRONT SHOULD WIND DOWN WEDNESDAY MORNING ACROSS
THE NORTHERN FORECAST AREA. WARM FRONT THEN EXPECTED TO LINGER JUST
NORTH OF THE CWA THROUGH THE DAY. MODELS INDICATING THAT TEMPS WILL
SOAR IN THE WARM SECTOR...WITH 925 MB TEMPS UP TO AROUND 32C ON THE
ECMWF AND EVEN WARMER WITH THE NAM. CONCERN IS CERTAINLY THERE THAT
OVERNIGHT CONVECTION MAY KEEP THE WARM FRONT FARTHER SOUTH...AND
THEN ALSO PULL IN COOLER AIR OFF THE LAKE NORTH OFF THE FRONT. FOR
NOW THOUGH...WENT WITH WHAT THE MODELS ARE SHOWING AND BUMPED TEMPS
UP TO AROUND 100 MOST PLACES...EXCEPT FOR IN THE NORTH TOWARD THE
WARM FRONT. TOO MUCH UNCERTAINTY WITH LINGERING CONVECTION/CLOUDS
AND PLACEMENT OF THE WARM FRONT...SO HELD OFF ON HEAT ADVISORY FOR
NOW. WILL EVENTUALLY NEED ONE IF MODELS CONTINUE DOWN THIS ROAD AND
FORECAST CONFIDENCE INCREASES. EVEN WITH DEWPOINTS MIXING INTO THE
MID AND UPPER 60S...TEMPS AROUND 100 WOULD RESULT IN HEAT INDICES IN
THE 100-105 RANGE.
CONVECTION WITH THE TRAILING COLD FRONT IS EXPECTED TO MAINLY HOLD
OFF UNTIL THE EVENING AND OVERNIGHT HOURS. WITH 30 KT LLJ ACROSS THE
AREA AND CAPES IN EXCESS OF 1000 J/KG...STILL THINKING STORMS SEVERE
STORMS ARE A POSSIBILITY AND SPC IS MAINTAINING A SLIGHT RISK.
KEPT SOME POPS THURSDAY MORNING...AS THE ECMWF LINGERS POST FRONTAL
PRECIP. OTHERWISE...SHOULD MAINLY BE DRY THURSDAY. A WEAK WAVE MAY
BRING A FEW MORE SHOWERS/STORMS TO THE AREA LATER IN THE DAY AND
OVERNIGHT.
THINKING THE SUN MAY POKE OUT FOR A TIME THURSDAY...SO PUSHED HIGHS
UP INTO THE MID AND UPPER 80S PER 925 MB TEMPS IN THE 22-25C RANGE.
.FRIDAY AND SATURDAY...FORECAST CONFIDENCE...MEDIUM
PRECIP MAY LINGER INTO FRIDAY MORNING AS THE SHORTWAVE EXITS...WITH
DRY WEATHER EXPECTED SATURDAY AS SFC HIGH PRESSURE MOVES OVERHEAD.
SHOULD SEE HIGHS COMFORTABLY NEAR NORMAL BOTH DAYS.
.SUNDAY AND MONDAY...FORECAST CONFIDENCE...MEDIUM
WITH UPPER RIDGE BUILDING IN TO THE WEST SUNDAY AND
MONDAY...COMBINATION OF WARM AIR ADVECTION AND A WEAK WAVE OR TWO
MAY KICK OFF SHOWERS/STORMS AT TIMES. WILL LIKELY SEE TEMPS START TO
WARM BACK UP.
&&
.AVIATION/12Z TAFS/...SCATTERED TO NUMEROUS CONVECTION LIKELY THIS
MORNING WITH MOST NUMEROUS CONVECTION TOWARDS KMSN. ENOUGH RAINFALL
TO MOISTEN LOW LEVELS EXPECTED TO PRODUCE PERIOD OF MVFR CIGS AT
KMSN. NOT AS CONFIDENT ON LOW CIGS FARTHER EAST WHERE RAINFALL MAY
BE A BIT MORE SCATTERED. MAY USE A TEMPO GROUP WITH 12Z ISSUANCE.
ANY LOWER CIGS SHOULD LIFT TO VFR THIS AFTN AS FORCING SLIDES SOUTH
OF AREA AND SLIGHTLY DRIER AIR GETS PULLED INTO THE LOWER LEVELS.
MORE SCT CONVECTION TONIGHT WITH STRONG RETURN FLOW.
&&
.MARINE...ONE TO TWO HOURS OF GUSTY NORTHEAST WINDS ACCOMPANIED
FROPA AS IT MOVED SOUTH ALONG THE LAKE MICHIGAN SHORE EARLY THIS
MORNING. THE FRONT WILL CONTINUE SAGGING SOUTHWARD WITH NORTHEAST
WINDS SETTLING DOWN TO 5 TO 15 KNOTS. SCATTERED T TO AFFECT NEAR
SHORE WATERS THIS MORNING AND AGAIN LATER TNGT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...MBK
WEDNESDAY THROUGH MONDAY...DDV
AREA FORECAST DISCUSSION...UPDATED
NWS PHOENIX AZ
535 AM MST TUE JUL 24 2012
.UPDATE...
UPDATED AVIATION AND FIRE WEATHER SECTIONS.
&&
.SYNOPSIS...
THUNDERSTORM CHANCES WILL BEGIN TO DECREASE OVER THE NEXT FEW DAYS
AS DRIER AIR SLOWLY WORKS IN FROM THE WEST. AFTER TODAY...STORM
CHANCES WILL MAINLY BE CONFINED TO THE HIGHER TERRAIN AREAS EAST OF
PHOENIX. DRIER AND SLIGHTLY WARMER WEATHER WILL SETTLE ACROSS THE
REGION FOR LATE THIS WEEK INTO THE WEEKEND...BEFORE A MORE ACTIVE
MONSOON PATTERN IS POSSIBLE BY THE EARLY PART OF NEXT WEEK.
&&
.DISCUSSION...
CONVECTION CONTINUES FROM GILA TO YAVAPAI COUNTIES THIS
MORNING...SENDING OUTFLOWS INTO THE VALLEY AND SPAWNING ISOLATED
SHOWERS AND THUNDERSTORMS AS FAR WEST AS THE ESTRELLA MOUNTAINS AS
OF 2 AM. NOT MUCH IN THE WAY OF SEVERE WEATHER PER SE...BUT THERE
HAVE BEEN REPORTS OF NEARLY 2 INCHES OF RAIN SINCE APPROX 10PM LAST
EVENING WITH THE STRONGEST STORMS. ONLY THE HRRR MODEL HAS ANY SENSE
OF WHATS GOING ON AT THE MOMENT...SHOWING STORMS DIMINISHING AROUND
12Z. WITH THIS IN MIND...I WILL MAINTAIN A CHANCE OF SHOWERS AND
THUNDERSTORMS IN THE FORECAST THROUGH THE PRE-DAWN HOURS EAST OF
PHOENIX.
ONGOING CONVECTION AND NUMEROUS OUTFLOWS ARE WREAKING HAVOC ON OUR
PRECIP CHANCES FOR LATER TODAY. ATMOSPHERE REMAINS PRIMED FOR
CONVECTION AT THE MOMENT PROVIDED THERE IS ENOUGH FORCING IN
PLACE...BUT MOISTURE WILL BEGIN ERODING FROM THE WEST LATER THIS
AFTERNOON AND CONSEQUENTLY...INSTABILITY IS EXPECTED TO DIMINISH
RAPIDLY BY 00Z. ON TOP OF THAT...THE ATMOSPHERE WILL ALMOST
CERTAINLY BE WORKED OVER ACROSS THE HIGHER TERRAIN. WHILE IT APPEARS
THERE IS STILL A CHANCE OF STORMS LATER TODAY...I HAVE REDUCED POPS
GIVEN THE ABOVE CONCERNS. AREAL COVERAGE AND EXTENT OF STORMS WOULD
HAVE BEEN LESSER TODAY ANYWAY GIVEN ERODING MOISTURE BUT I THINK
THIS OVERNIGHT COMPLEX WILL LESSEN COVERAGE EVEN MORE.
A BIT OF A BREAK FROM THE MONSOON LOOKS LIKELY FROM WEDNESDAY
THROUGH SATURDAY AS MOISTURE DECREASES AND INSTABILITY DROPS TO
NOTHING. PRECIP CHANCES WERE CHANGED ONLY SLIGHTLY EACH
DAY...GENERALLY CLIMO MINUS 10 OR 15 PERCENT. SOME SUGGESTION OF AN
EASTERLY WAVE/INVERTED TROUGH MOVING THROUGH THE AREA LATE THIS
WEEKEND INTO EARLY NEXT WEEK. WITH THIS IN MIND...I STARTED BRINGING
POPS BACK INTO THE DESERTS ON SUNDAY AND MONDAY ALTHOUGH FIGURING
OUT THE EXACT TIMING THIS FAR IN ADVANCE IS TRICKY AT BEST.
&&
.AVIATION...
SOUTH CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
SHOWER AND THUNDERSTORM ACTIVITY OVER HIGHER TERRAIN NORTH AND EAST
OF THE PHOENIX AREA IS FINALLY TRENDING DOWN EARLY THIS MORNING.
SOME ISOLATED WEAK SHOWERS MAY STILL POP UP OVER THE METRO AREA
BEFORE 16Z BUT TOO LOW A PROBABILITY TO INCLUDE IN THE TAFS.
ANTICIPATE THUNDERSTORM ACTIVITY TO FLIRT WITH THE METRO AREA ONCE
AGAIN LATER TODAY AND TONIGHT WITH OUTFLOW WINDS CAUSING ERRATIC
WIND SHIFTS. NO WIDESPREAD STORM DEVELOPMENT IS ANTICIPATED OVER THE
METRO BUT STORMS CAN BE EXPECTED AFTER 23Z NEAR THE FOOTHILLS.
CONFIDENCE IN STORM OCCURRENCE AT THE TAF SITES NOT HIGH ENOUGH AT
THIS TIME TO INSERT TEMPO/PROB TSRA IN THE TAFS. OTHERWISE...WINDS
WILL BE LIGHT AND FAVOR TYPICAL DIURNAL PATTERNS.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
VERY ISOLATED SHOWERS OVER SOUTHEAST CALIFORNIA ARE ANTICIPATED TO
DISSIPATE BY 15Z AND MAY DRIFT OVER KBLH. OTHERWISE...STORM ACTIVITY
LATER TODAY IS EXPECTED TO BE EAST OF THE LOWER COLORADO RIVER
VALLEY. ANTICIPATE WINDS TO FOLLOW A SIMILAR PATTERN TO THE PREVIOUS
24 HOURS WITH AFTERNOON GUSTS A BIT STRONGER AT KBLH THAN YESTERDAY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
ATMOSPHERIC MOISTURE AND ASSOCIATED THUNDERSTORM ACTIVITY IS
EXPECTED TO BEGIN TRENDING UPWARD LATE THIS WEEK INTO EARLY NEXT
WEEK AS A WEATHER DISTURBANCE TRACKS WESTWARD ACROSS FAR NORTHERN
MEXICO. ACCORDINGLY...HUMIDITIES WILL TREND SLOWLY UPWARD FROM EAST
TO WEST. APART FROM THUNDERSTORMS...WINDS ARE EXPECTED TO FOLLOW
FAMILIAR WARM SEASON DIURNAL PATTERNS. THUNDERSTORM CHANCES ARE
EXPECTED TO REMAIN PRIMARILY EAST OF THE LOWER COLORADO RIVER
VALLEY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...LEINS
AVIATION...AJ
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1159 AM EDT Tue Jul 24 2012
.NEAR TERM [Through Tonight]...
This mornings upper level RAP analysis shows the ridge centered
over the middle Mississippi Valley nosing southeast into our local
area. At the surface, a weak tropical low is found centered in
Apalachee Bay, sandwiched between two areas of high pressure.
This mornings sounding was slightly more moist than this time
yesterday, with most of this moisture residing in the the lower
troposphere. The aforementioned upper level ridge is responsible
for the drier middle to upper levels, especially across Alabama
and Georgia. Nevertheless, low level convergence associated with
the embattled wind field between the surface low and high pressure
systems will provide the mesoscale forcing needed to generate
showers and thunderstorms this afternoon. The best moisture will
be found across portions of north Florida, as clearly noted by the
early onset of CU this morning. Deep moist convection is not
expected for most areas this afternoon, storms that form will
remain rather shallow and benign. The only exception may be across
the panhandle of Florida and extreme SE Alabama, where a storm or
two may become mature enough to produce sub-severe downbursts.
Although the dry air will limit the deep convection, still expect
a rather healthy scattering of storms along the convergent zone
from say Albany, southwest to Pensacola. This loosely organized
line of storms will drift southeast through the late afternoon and
evening and diminish before midnight. Will have to be aware of the
evolution of convection across the Mid-Atlantic states this
afternoon as there are subtle hints of an MCS diving southwest
into our region late this evening. However, confidence in this
solution is low.
Max temperatures today will be similar to yesterday, warmer closer
to the upper ridge (NW) and more seasonable elsewhere (SW).
&&
.SHORT TERM [Wednesday Through Thursday]...
Wednesday, the upper ridge will build closer to the region
keeping temps above climo. Most areas along and north of I-10 will
reach the mid to upper 90s with maximum heat indices of 107-109
across the northern half of the forecast area. PoPs will also
increase to around climo (40-60). Thursday will be very similar to
Wednesday.
&&
.LONG TERM [Thursday Night through Monday]...
Not too much change to the previous thinking for the long term
forecast this cycle. The large ridge that has been in place across
the Southeast will gradually break down as the overall pattern
shifts to a trough in the Eastern CONUS and a ridge out west. Both
the GFS and Euro are consistent in bringing a weak frontal boundary
into the region by the weekend. PoPs are expected to increase
slightly this weekend as a result of the weakening ridge/approaching
boundary and the daily sea breeze circulation. This boundary should
weaken and dissipate by the first of the week, but with the presence
of the East Coast trough, rain chances late in the period are
expected to remain near climatological norms.
The temps will not vary greatly during the long term forecast, with
lows in the upper 70s and during the day the highs reaching mid 90s.
&&
.AVIATION [Beginning 16Z Tuesday]...
VFR conditions expected for the remainder of the afternoon.
Scattered storms are expected to impact KABY, KDHN, and KECP later
this afternoon. The storms have the potential to impact KTLH and
KVLD closer to the evening hours. Areas receiving rain will have a
greater threat of experiencing IFR to MVFR fog, transitioning to
low ceilings tomorrow morning.
&&
.MARINE...
The surface ridge axis will remain parked south of the area through
the entire forecast period. Therefore we can expect mainly southwest
winds (occasionally west) at speeds below headline criteria. There
will be some modest enhancement near the coast in the afternoon sea
breeze and of course near any convection.
&&
.FIRE WEATHER...
With low level south to southwesterly flow persisting through much
of this week, moisture levels are expected to remain well above
critical thresholds precluding red flag criteria.
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...Harrigan
SHORT TERM...Wool
LONG TERM...Godsey
AVIATION...
MARINE...Wool
FIRE WEATHER...Godsey
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
605 AM CDT TUE JUL 24 2012
...UPDATE TO AVIATION...
.SYNOPSIS...
ISSUED AT 112 AM CDT TUE JUL 24 2012
A FAIRLY IMPRESSIVE UPPER LOW BY MID-SUMMER STANDARDS WAS CENTERED
OVER SOUTHERN ALBERTA AS OF 24.05Z WITH A COMPACT 70-80 KNOT JET
STREAK ON THE SOUTHEAST SIDE OF THE LOW AT 400MB (PER RAP ANALYSIS).
THERE WAS ANOTHER DEPARTING MID-UPPER LEVEL TROUGH ACROSS
SOUTHEASTERN CANADA TO THE NORTHERN GREAT LAKES REGION. IN THE
LOWER TROPOSPHERE...A FRONT WAS EVIDENT IN THE 850MB ANALYSIS
EXTENDING FROM LOWER MICHIGAN TO SOUTHERN MINNESOTA. THE FRONT
CONTINUED WEST TOWARD JUST SOUTH OF THE BLACK HILLS REGION WHICH
COULD BE FOLLOWED BACK NORTHWEST INTO CENTRAL/EASTERN MONTANA.
FAIRLY STRONG COLD FRONTOGENESIS WAS BECOMING INCREASINGLY EVIDENT
ACROSS WESTERN MONTANA WITH 850MB TEMPERATURES BEHIND THE COLD FRONT
IN WASHINGTON STATE FROM +6 TO +11C. THE HOTTEST TEMPERATURES AT
850MB WERE FOUND ALONG A LINE FROM ROUGHLY THE NEBRASKA PANHANDLE TO
SOUTHEASTERN SOUTH DAKOTA WHERE TEMPS RANGED FROM +30 TO +33C ALONG
THIS AXIS. WITHIN THIS HEAT AXIS...VALENTINE NEBRASKA REACHED A HIGH
TEMPERATURE OF 109F.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 406 AM CDT TUE JUL 24 2012
AS THE STRONG, COMPACT UPPER LOW MOVES EAST ACROSS THE CANADIAN
PRAIRIES TODAY...THE COLD FRONT TIED TO THIS UPPER FEATURE WILL MOVE
SOUTH DOWN THE NORTHERN HIGH PLAINS TODAY AND TONIGHT. AS THIS IS
HAPPENING...THE LEE TROUGH OVER EASTERN COLORADO WILL FURTHER
DEEPEN AS WELL RESULTING IN INCREASED PRESSURE GRADIENT AND STRONGER
SURFACE WINDS. 18 TO 22 KT SURFACE WINDS ARE FORECAST ACROSS
SOUTHWEST KANSAS FROM THE SOUTH-SOUTHWEST. HIGHS WILL BE SIMILAR TO
THAT OF THE PAST FEW DAYS...WITH WARMEST TEMPERATURES FARTHER NORTH
WHERE THE LOW LEVEL THERMAL NOSE WILL ADVANCE FARTHER EAST IN
NORTHWEST KANSAS SUPPORTING 105 TO 107 DEGREE LATE AFTERNOON
TEMPERATURES. ELSEWHERE SOUTH OF A SCOTT CITY TO HAYS LINE HIGHS
WILL RANGE FROM 100 TO 103F. TONIGHT...THE PRESSURE GRADIENT WILL
STILL BE STRONG ENOUGH TO KEEP WINDS UP IN THE 10-15 KNOT RANGE
THROUGH THE NIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 406 AM CDT TUE JUL 24 2012
MEDIUM RANGE MODELS INDICATE AN UPPER LEVEL SHORTWAVE TROUGH OF LOW
PRESSURE EJECTING EASTWARD OUT OF THE CENTRAL AND SOUTHERN ROCKIES
INTO THE WESTERN HIGH PLAINS WEDNESDAY BRINGING A MUCH NEEDED CHANCE
FOR PRECIP TO PORTIONS OF WESTERN KANSAS. AN ATTENDANT COLD FRONT IS
PROJECTED TO PUSH SOUTHEAST INTO WESTERN KANSAS SOMETIME BY EARLY TO
MID AFTERNOON WEDNESDAY SETTING THE STAGE FOR POSSIBLE SHOWER AND
THUNDERSTORM DEVELOPMENT. AS THE FRONT BEGINS TO PUSH INTO THE STATE,
THE NAM, GEM, GFS, AND ECMWF POINT TO A SURFACE LOW DEVELOPING ALONG
THE FRONT, GENERALLY ACROSS SOUTHWEST KANSAS. THIS WILL INCREASE LOW
LEVEL FORCING, PARTICULARLY TO THE NORTH AND EAST OF THE SURFACE LOW
ALONG THE BOUNDARY ITSELF. AMPLE MOISTURE WILL BE ON HAND AS A
PREVAILING LOW LEVEL SOUTHERLY FLOW IS EXPECTED TO DRIVE IT NORTH
WITH H85 DEWPOINTS JUST ABOVE 10C ACROSS MUCH OF CENTRAL AND WESTERN
KANSAS. ADDITIONALLY, NAM AND GFS MODEL SOUNDINGS DO POINT TO PLENTY
OF AVAILABLE MID/UPPER LEVEL INSTABILITY BY WEDNESDAY AFTERNOON WITH
CAPE VALUES IN EXCESS OF 1500 TO 2000 J/KG. HOWEVER, A COUPLE OF
FACTORS MAY LIMIT CONVECTION ACROSS WESTERN KANSAS AS THE FRONTAL
BOUNDARY BEGINS TO PUSH INTO THE AREA. FIRST WILL BE AN EXPECTED
WEAK FLOW ALOFT AS ALL MODELS KEEP THE UPPER LEVEL JET JUST OFF TO
OUR NORTH ACROSS THE NORTHERN PLAINS. CAPPING COULD ALSO PLAY A
LIMITING FACTOR AS A HOT AFTERNOON THE PREVIOUS DAY WILL HAVE HIGH
TEMPERATURES UP NEAR TO JUST ABOVE 100F.
BECAUSE OF THE WEAK FLOW ALOFT AND THE LIKELY LOCATION OF THE
DEVELOPING SURFACE LOW, WILL KEEP 30 POPS IN ACROSS MUCH OF THE AREA
WITH 40 POPS FURTHER NORTHEAST IN CENTRAL KANSAS, ALONG WHERE THE
BOUNDARY IS EXPECTED TO BE LATE WEDNESDAY. ANY DEVELOPING STORMS ARE
ALSO EXPECTED TO BE ELEVATED WITH STRONG OUTFLOW WINDS THE PRIMARY
THREAT. DRIER CONDITIONS ARE EXPECTED THROUGH THE REMAINDER OF THE
PERIOD AS UPPER LEVEL RIDGING REDEVELOPS ACROSS THE INTERMOUNTAIN
WEST BY THURSDAY AND PUSHES SLOWLY EAST INTO THE WESTERN HIGH PLAINS
THROUGH THE WEEKEND.
TEMPERATURES ARE EXPECTED TO BE ABOVE NORMAL WEDNESDAY EVEN AS THE
COLD FRONT BEGINS TO PUSH SOUTHEAST INTO WESTERN KANSAS BY MID DAY.
AHEAD OF THE COLD FRONT, THE NAM, GFS, AND ECMWF SHOW H85
TEMPERATURES RANGING FROM THE UPPER 20S(C) ACROSS CENTRAL KANSAS
TO JUST ABOVE 30C ACROSS MUCH OF SOUTHWEST KANSAS. CONSIDERING HOW
SLOW THE MODELS HAVE THE FRONT PROJECTED TO MOVE THROUGH THE AREA,
LOOK FOR HIGHS ABOVE 100F ACROSS CENTRAL AND MUCH OF SOUTHWEST
KANSAS AGAIN WEDNESDAY AFTERNOON. HOWEVER, A BRIEF REPRIEVE FROM
TRIPLE DIGIT HIGHS IS LIKELY THURSDAY IN WAKE OF THE SLOW MOVING
COLD FRONT. A NORTH TO NORTHEAST LOW LEVEL FLOW INTO WESTERN KANSAS
WILL HELP LOWER H85 TEMPERATURES BY JUST A FEW DEGREES. EVEN SO,
EXPECT HIGHS ONLY UP INTO THE 90S(F) THURSDAY AFTERNOON. A GRADUAL
WARMING TREND IS THEN EXPECTED AGAIN AS THE AFOREMENTIONED UPPER
LEVEL RIDGING DEVELOPS ACROSS THE INTERMOUNTAIN WEST BY THURSDAY AND
BEGINS TO PUSH EAST INTO THE WESTERN HIGH PLAINS THROUGH THE WEEKEND.
SHOULD SEE HIGHS CLIMBING BACK TO JUST ABOVE 100F BY THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 603 AM CDT TUE JUL 24 2012
VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES THROUGH LATE THIS
EVENING. AS FOR WINDS, A LEE SIDE TROUGH OF LOW PRESSURE WILL
STRENGTHEN ACROSS EXTREME EASTERN COLORADO TODAY. AS A RESULT,
SOUTHERLY WINDS OF 10 TO 15KT EARLY THIS MORNING WILL INCREASE
UP TO AROUND 20 TO 30KT THROUGH EARLY THIS AFTERNOON. WINDS WILL
SUBSIDE BACK TO AROUND 10 TO 15KT THIS EVENING WITH THE LOSS OF
DAYTIME HEATING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 101 73 103 69 / 10 10 20 30
GCK 104 70 102 68 / 10 10 30 30
EHA 99 70 98 66 / 20 20 30 30
LBL 100 72 102 69 / 20 20 30 30
HYS 106 73 104 69 / 0 10 30 40
P28 102 75 104 72 / 10 10 10 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...UMSCHEID
SHORT TERM...UMSCHEID
LONG TERM...JJOHNSON
AVIATION...JJOHNSON
AREA FORECAST DISCUSSION
NWS JACKSON KY
1057 AM EDT TUE JUL 24 2012
.UPDATE...
ISSUED AT 1057 AM EDT TUE JUL 24 2012
COMPLEX OF SHOWERS AND STORMS CURRENTLY DROPPING SOUTHEAST ACROSS
EASTERN KENTUCKY. VERY COMPLEX PATTERN SETTING UP FOR THIS AFTERNOON.
IT LOOKS LIKE A DIFFERENTIAL TEMPERATURE BOUNDARY MAY BECOME
ESTABLISHED AFTER THIS MORNINGS ACTIVITY EXITS...CREATING A FOCUS FOR
NEW DEVELOPMENT BASICALLY ALONG AND SOUTHWEST OF A LINE FROM MOUNT
STERLING...THROUGH JACKSON...TO HARLAN. THUS...BELIEVE THE TARGETED
AREA WILL BE OUR MORE SOUTHWESTERN ZONES...CONTRARY TO THE PREVIOUS
FORECAST. THE HRRR SUPPORTS THIS IDEA WITH MOST OF THE ACTIVITY THIS
AFTERNOON AND EVENING IN OUR SOUTHWEST. THIS IS ALSO SUPPORTED BY AN
OUTFLOW BOUNDARY GENERATED FROM AN MCS CURRENTLY PUSHING INTO
SOUTHWEST OHIO. THIS WILL LIKELY PUSH THIS OUTFLOW BOUNDARY INTO
EASTERN KENTUCKY AS THIS SYSTEM TRACKS SOUTH AND EAST INTO WEST
VIRGINIA BY MIDDAY. THE AREA SEEING THE SHOWER AND STORM ACTIVITY
PRESENTLY WILL HAVE A TOUGH TIME REGENERATING ANY INSTABILITY...BUT
AREAS UNTAPPED TO THE SOUTHWEST WILL BE A DIFFERENT STORY. THUS...THE
SEVERE THREAT STILL SEEMS REASONABLE...BUT MAINLY FOR THE SOUTHWEST
ZONES. DAMAGING WINDS WILL BE THE PRIMARY THREAT. IT APPEARS THE MAIN
THREAT FOR SEVERE WEATHER WILL START AFTER 3 PM UNTIL 9 OR 10 PM.
UPDATE ISSUED AT 804 AM EDT TUE JUL 24 2012
UPDATED TO ALLOW FOR EARLIER ARRIVAL OF PRECIP POTENTIAL TODAY...WITH
SCATTERED SHOWERS AND STORMS ALREADY PRESENTLY DEVELOPING AND
ENTERING THE FORECAST AREA FROM THE NW.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 352 AM EDT TUE JUL 24 2012
THUNDERSTORMS WERE EXPLODING UPSTREAM OVER NORTH CENTRAL INDIANA AT
3 AM...WITH MORE OF THEM FURTHER NORTHWEST OVER THE UPPER MISSISSIPPI
VALLEY. THIS ACTIVITY INITIATED NEAR A FRONTAL BOUNDARY UNDER THE
PERIPHERY OF AN UPPER RIDGE. MODELS SHOW CONVECTION RUNNING AROUND
THE PERIPHERY OF THE RIDGE AND DEVELOPING/PROPAGATING INTO THE LOCAL
AREA DURING THE DAY. FORECAST SOUNDINGS SHOW AMPLE INSTABILITY
BUILDING DURING THE DAY...WITH CAPE LIKELY REACHING 2500-3000 J/KG.
ALTHOUGH SHEAR WILL NOT BE PHENOMENAL...IT SHOULD AT LEAST ALLOW FOR
ORGANIZATION...WITH A LIMITED AMOUNT OF BOTH SPEED AND DIRECTIONAL
SHEAR. IT WILL BE THROUGH A DEEP LAYER AND NOT CONCENTRATED IN THE
LOW LEVELS. ALSO FREEZING LEVELS WILL BE HIGH...IN THE NEIGHBORHOOD
OF 14-14.5K FEET. THUS...THE MAIN SEVERE THREAT LOOKS TO BE
WIND...BUT WITH STRONG INSTABILITY AND SOME POTENTIAL FOR STORM
ROTATION...HAIL ALSO NEEDS TO BE CONSIDERED.
THE SURFACE COLD FRONT IS EXPECTED TO SAG INTO KY TONIGHT...AND WOULD
NOT RULE OUT ADDITIONAL CONVECTION DEVELOPING. HOWEVER...IF
INSTABILITY IS SPENT ON EARLIER CONVECTION...CONFIDENCE IN COVERAGE
IS NOT AS HIGH DURING THE NIGHT.
ON WEDNESDAY...THE FRONT RETREATS TO THE NORTHEAST AND UPPER RIDGING
ALSO SHIFTS EASTWARD OVER THE AREA...WITH WINDS ALOFT WEAKENING. LOW
LEVEL MOISTURE SHOULD ALSO BE SLIGHTLY LESS...WHILE MID LEVEL TEMPS
WARM SLIGHTLY. ALL COMBINED...CONDITIONS WILL NOT BE AS FAVORABLE FOR
WIDESPREAD CONVECTION...AND HAVE USED LOWER POPS ONLY IN THE SLIGHT
CHANCE RANGE ON WEDNESDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 400 AM EDT TUE JUL 24 2012
THE 24.00Z MODEL SUITE REMAINS IN FAIRLY GOOD AGREEMENT WITH THE
EVOLUTION OF THE UPPER LEVEL PATTERN THROUGH THE MAJORITY OF THE
PERIOD BUT DOES SHOW MINOR DIFFERENCES WITH HOW THINGS END UP TOWARDS
THE BEGINNING OF NEXT WEEK. AS SUCH...HAVE GENERALLY RELIED ON A
BLENDED CONSENSUS WITH A LITTLE MORE WEIGHT TO A SLIGHTLY MORE
REASONABLE 24.00Z ECMWF FOR SPECIFICS. WILL KICK OFF WITH ANY
LINGERING ACTIVITY FROM WEDNESDAY DWINDLING WITH THE USUAL LOSS OF
DAYTIME HEATING INFLUENCES AS ANOTHER LOW PRESSURE SYSTEM CURRENTLY
OVER THE CANADIAN ROCKIES BEGINS CARVING INTO THE NRN PLAINS AND
UPPER MIDWEST. THE SFC REFLECTION IS EXPECTED TO BEGIN TRAVERSING THE
GREAT LAKES WEDNESDAY NIGHT INTO THURSDAY WITH THE ASSOCIATED RAINS
ALONG THE COLD FRONT STILL OVER THE MIDWEST AND UPPER MS VALLEY.
CURRENT CONSENSUS BRINGS THE FORCING ASSOCIATED WITH THE FRONT INTO
THE LOCAL PICTURE LATE THURSDAY/THURSDAY NIGHT AND CONTINUING
THROUGH THE DAY ON FRIDAY AS FAVORABLE RIGHT ENTRANCE DYNAMICS OF AN
UPPER LEVEL JET GRACES THE OHIO VALLEY. HAVE TRENDED THE FORECAST
DRIER FOR MUCH OF THE AREA THROUGH MOST OF THURSDAY WITH POPS
PEAKING THURSDAY NIGHT AND FRIDAY. MODELS ARE FAIRLY PROGRESSIVE
WITH THE PARENT UPPER LEVEL TROF...PUSHING IT THROUGH THE COAL
FIELDS ON SATURDAY AS HEIGHTS BEGIN SLOWLY REBOUNDING OVER ERN KY IN
RESPONSE TO SFC HIGH PRESSURE BUILDING DOWN FROM THE GREAT LAKES
WHILE THE PERSISTENT UPPER LEVEL PLAINS RIDGE BEGINS REBUILDING AND
EXPANDING ACROSS THE MS VALLEY. THIS SHOULD PROVIDE FOR A RELATIVELY
QUIET...IF NOT DRY SPELL OVER MOST OF THE UPCOMING WEEKEND.
AS FOR TEMPERATURES...GIVEN THE RELATIVELY GOOD AGREEMENT AMONG THE
GUIDANCE SAW NO REASON TO DEVIATE TOO FAR FROM THE LATEST OFFERINGS
WHICH WERE STILL IN LINE WITH THE INHERITED NUMBERS. THIS RESULTED
IN TEMPS GENERALLY RUNNING ABOVE NORMAL EARLY IN THE PERIOD...WITH
HEAT INDICES ON THURSDAY QUITE POSSIBLY RETURNING TO THE TRIPLE
DIGITS AHEAD OF THE FRONT...BEFORE TURNING TOWARDS CLIMO ON FRIDAY
WITH HIGHS IN THE MID TO UPPER 80S AND OVERNIGHT LOWS GENERALLY IN
THE UPPER 60S THROUGH THE REMAINDER OF THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 804 AM EDT TUE JUL 24 2012
SCATTERED SHOWERS AND THUNDERSTORMS WERE ENTERING THE FORECAST AREA
FROM THE NORTHWEST AT THE START OF THE PERIOD...AND WILL CONTINUE TO
INCREASE IN COVERAGE. THEY WILL BRING LOCALIZED IFR TODAY. IF ENOUGH
DESTABILIZATION CAN OCCUR...SOME OF THE STORMS MAY BRING STRONG WINDS
AND POSSIBLY HAIL IN THE AFTERNOON. WILL EXPECT A RELATIVE LULL IN
PRECIP LATE THIS EVENING AND OVERNIGHT. HOWEVER...FOG WILL BE A
THREAT TONIGHT...ESPECIALLY IN VALLEY LOCATIONS IF CLOUDS BREAK UP.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...HAL
LONG TERM....MB
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1022 AM EDT TUE JUL 24 2012
.SYNOPSIS...
A COLD FRONT, MOVING SOUTHWARD THROUGH THE UPPER OHIO VALLEY, CAN
STILL CAUSE SCATTERED THUNDERSTORMS INTO EARLY EVENING, MORE SO
SOUTH OF THE INTERSTATE 70 CORRIDOR THAN NORTH. ANOTHER FRONT
WILL BRING SCATTERED THUNDERSTORMS THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
RECENT RADAR AND SURFACE DATA SHOW THE INITIAL BATCH OF SEVERE
THUNDERSTORMS HAS EXITED EAST PAST THE APPALACHIAN MOUNTAINS,
WHILE ADDITIONAL PREFRONTAL SCATTERED SHOWERS AND THUNDERSTORMS
WERE MOVING SOUTHEASTWARD ACROSS EAST CENTRAL OHIO.
USING THIS DATA AS WELL AS RECENT HRRR AND WRF-NMM MODEL OUTPUT, HAVE
ACCORDINGLY ADJUSTED MENTION OF THUNDERSTORM COVERAGE, AND
TEMPERATURES THROUGH AFTERNOON.
THUNDERSTORMS CAN BE SCATTERED AS FAR NORTH AS THE NEW
PHILADELPHIA-PITTSBURGH CORRIDOR THIS AFTERNOON. HIGH TEMPERATURES
HAVE BEEN TRIMMED BY 1-2 DEGREES DUE TO EVAPORATIVE-COOLING
EFFECTS OF THIS MORNINGS RAINFALL.
EXPECT POSTFRONTAL NORTHWESTERLY WINDS TO END REMAINING SHOWERS
THIS EVENING, AND PROVIDE LOWER DEW POINTS. WILL CONSIDER LATE
NIGHT FOG PROSPECTS WITH NEXT UPDATE.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
TODAY/S FRONT SHOULD LIFT BACK TO THE NORTH WEDNESDAY AND WEDNESDAY
NIGHT AS A WARM FRONT. STILL UNSURE AS TO JUST HOW PRECIPITATION THE
FRONT WILL GENERATE ON ITS RETURN TRIP. 00Z MODEL RUNS HAVE
ACCELERATED THE WARM FRONT PASSAGE...AND NOW SHOW THAT THE FRONT
WILL LIKELY MOVE THROUGH WEDNESDAY EVENING. THIS TIMING SHOULD LIMIT
DIURNAL ENHANCEMENT OF SHOWERS/STORMS. THE FASTER TIMING WILL ALSO
KEEP WEDNESDAY NIGHT LOWS A BIT HIGHER AS WELL WITH THE REGION
RETURNING TO THE WARM SECTOR MORE QUICKLY.
LOW PRESSURE WILL TRACK FROM LOWER MICHIGAN TOWARDS NEW ENGLAND ON
THURSDAY...DRAGGING A COLD FRONT TO THE SOUTHEAST. WITH THE FRONT
SLIDING THROUGH THE REGION SLOWLY...THIS COULD PROVIDE AN EXTENDED
PERIOD FOR SHOWERS AND STORMS FOR ALL OF THURSDAY AND FRIDAY. ANY
POTENTIAL FOR SEVERE WEATHER ON THURSDAY WILL BE DEPENDENT ON
LOCATION OF THE FRONT. FOR NOW...SPC HAS DEPICTED A BROAD AREA FOR
SEVERE POTENTIAL ON THURSDAY..INCLUDING THE ENTIRE FORECAST AREA.
THURSDAY APPEARS TO BE THE WARMEST DAY WHILE THE REGION IS IN THE
WARM SECTOR...WITH TEMPERATURES AROUND 90. TEMPS SHOULD BE SEASONAL
FOR WEDNESDAY AND FRIDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
LATEST MEDIUM RANGE MODELS STILL DIG A SHORT WAVE TROUGH ACROSS THE
GREAT LAKES REGION FRIDAY AND SLOWLY MOVE THE TROUGH AXIS MOVE EAST
TO THE NEW ENGLAND COAST BY MONDAY.
KEPT SCATTERED SHOWERS AND THUNDERSTORMS IN THE FORECAST FRIDAY
NIGHT AND SATURDAY...WITH DRY WEATHER EXPECTED SUNDAY INTO MONDAY
AS THE UPPER TROUGH MOVES EAST AND A WEAK SURFACE HIGH BRINGS
DRIER AIR IN FROM THE NORTHWEST.
FORECAST TEMPERATURES ARE CLOSE TO HPC GUIDANCE AND NEAR NORMAL
THROUGH THE EXTENDED PERIOD.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
PER RECENT SURFACE AND RADAR DATA, COUPLED WITH HRRR MODEL OUTPUT,
MAINTAINED MENTION OF TEMPO MVFR RESTRICTIONS WITH SHOWERS AND
SCATTERED THUNDERSTORMS KZZV-KPIT AND SOUTH. SURFACE WINDS WILL
BECOME NORTHWEST NEAR 10 KTS WITH GUSTS TO 20 KTS. HIGHER GUSTS
POSSIBLE NEAR THUNDERSTORMS.
POSTFRONTAL DRYING WILL PROMOTE VFR STARTING THIS EVENING.
POTENTIAL FOR LATE NIGHT PATCHY FOG MAY PRODUCE RESTRICTIONS, BUT
NOT ENOUGH CONFIDENCE TO MENTION IN TAF.
OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
GEN VFR...BUT WITH PERIODIC CHCS FOR TSRA/ASSOCIATED RESTRICTIONS
ARE EXPECTED FOR THE REMAINDER OF THE WEEK AS A SERIES OF SHRTWVS
TRACK ACRS THE UPR OH VALLEY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
608 AM EDT TUE JUL 24 2012
.SYNOPSIS...
AS A COLD FRONT MOVES THROUGH TODAY...SEVERE WEATHER COULD IMPACT
LOCATIONS TO THE SOUTH OF PITTSBURGH. ANOTHER FRONT WILL BRING
SCATTERED THUNDERSTORMS FOR THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
COLD FRONT IS CURRENTLY DRAPED ACROSS LOWER MICHIGAN...EXTENDING
EAST TO JUST NORTH OF LAKE ERIE. THE FRONT WILL DROP SOUTH THROUGH
THE REGION TODAY...WITH ENHANCEMENT PROVIDED BY AN UPPER LEVEL
SHORTWAVE THAT IS EXPECTED TO TRACK FROM WISCONSIN SOUTHEAST INTO
NORTH CAROLINA. WHILE EFFECTIVE SHEAR VALUES AROUND 30-35 KTS ARE
EXPECTED TO TRACK ALONG THE FRONT...MODERATE CAPE VALUES WILL
PRIMARILY REMAIN SOUTH OF THE MASON-DIXON LINE. AS A RESULT...THINK
THAT BEST LOCAL POTENTIAL FOR SEVERE WILL REMAIN GENERALLY SOUTH OF
A LINE FROM ZANESVILLE TO MORGANTOWN. HOWEVER...IMPORTANT TO NOTE
THAT SPC SLIGHT RISK FOR SEVERE WEATHER INCLUDES ALL LOCATIONS SOUTH
OF A LINE FROM NEW PHILADELPHIA TO WHEELING AND LATROBE. WITH THE
SHORTWAVE RACING SOUTHEAST...BEST CHANCE FOR ANY PRECIPITATION
SHOULD BE LATE MORNING AND THE EARLY AFTERNOON...PROVIDING ANOTHER
POTENTIAL LIMITING FACTOR FOR SEVERE WEATHER. EXPECT DRY
CONDITIONS EVERYWHERE TONIGHT...AND MUCH COOLER/DRIER AIR. LOWS
SHOULD DROP INTO THE 50S IN ALL LOCATIONS.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
TODAY/S FRONT SHOULD LIFT BACK TO THE NORTH WEDNESDAY AND WEDNESDAY
NIGHT AS A WARM FRONT. STILL UNSURE AS TO JUST HOW PRECIPITATION THE
FRONT WILL GENERATE ON ITS RETURN TRIP. 00Z MODEL RUNS HAVE
ACCELERATED THE WARM FRONT PASSAGE...AND NOW SHOW THAT THE FRONT
WILL LIKELY MOVE THROUGH WEDNESDAY EVENING. THIS TIMING SHOULD LIMIT
DIURNAL ENHANCEMENT OF SHOWERS/STORMS. THE FASTER TIMING WILL ALSO
KEEP WEDNESDAY NIGHT LOWS A BIT HIGHER AS WELL WITH THE REGION
RETURNING TO THE WARM SECTOR MORE QUICKLY.
LOW PRESSURE WILL TRACK FROM LOWER MICHIGAN TOWARDS NEW ENGLAND ON
THURSDAY...DRAGGING A COLD FRONT TO THE SOUTHEAST. WITH THE FRONT
SLIDING THROUGH THE REGION SLOWLY...THIS COULD PROVIDE AN EXTENDED
PERIOD FOR SHOWERS AND STORMS FOR ALL OF THURSDAY AND FRIDAY. ANY
POTENTIAL FOR SEVERE WEATHER ON THURSDAY WILL BE DEPENDENT ON
LOCATION OF THE FRONT. FOR NOW...SPC HAS DEPICTED A BROAD AREA FOR
SEVERE POTENTIAL ON THURSDAY..INCLUDING THE ENTIRE FORECAST AREA.
THURSDAY APPEARS TO BE THE WARMEST DAY WHILE THE REGION IS IN THE
WARM SECTOR...WITH TEMPERATURES AROUND 90. TEMPS SHOULD BE SEASONAL
FOR WEDNESDAY AND FRIDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
LATEST MEDIUM RANGE MODELS STILL DIG A SHORT WAVE TROUGH ACROSS THE
GREAT LAKES REGION FRIDAY AND SLOWLY MOVE THE TROUGH AXIS MOVE EAST
TO THE NEW ENGLAND COAST BY MONDAY.
KEPT SCATTERED SHOWERS AND THUNDERSTORMS IN THE FORECAST FRIDAY
NIGHT AND SATURDAY...WITH DRY WEATHER EXPECTED SUNDAY INTO MONDAY
AS THE UPPER TROUGH MOVES EAST AND A WEAK SURFACE HIGH BRINGS
DRIER AIR IN FROM THE NORTHWEST.
FORECAST TEMPERATURES ARE CLOSE TO HPC GUIDANCE AND NEAR NORMAL
THROUGH THE EXTENDED PERIOD.
&&
.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
SHRTWV IN NW FLOW WL SUPPORT MOIST...DEEP CONVECTION ALONG SWD SAGGING
CDFNT TODAY. THIS WEATHER IS EXPECTED TO AFFECT PORTS FM PIT SWD
WITH MVFR/ISOLD IFR CONDITIONS AND TAFS HAVE BEEN CONSTRUCTED
ACCORDINGLY USING THE LATEST HRRR TIMING AND GENL PLACEMENT.
OTHERWISE SFC WND WL VEER TO THE W AND NW WITH PASSAGE OF THE SFC
REFLECTION. BUILDING SFC HIGH IS EXPECTED TO RESULT IN VFR
CONDITIONS AT ALL PORTS BY LATE AFTN.
OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
GENL VFR...BUT WITH PERIODIC CHCS FOR TSRA/ASSOCIATED RESTRICTIONS
ARE EXPECTED FOR THE REMAINDER OF THE WEEK AS A SERIES OF SHRTWVS
TRACK ACRS THE UPR OH VALLEY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1109 AM EDT TUE JUL 24 2012
.SYNOPSIS...
A WEAK UPPER LEVEL RIDGE WILL BUILD ACROSS THE REGION AND PERSIST
THROUGH THURSDAY. A COLD FRONT IS THEN EXPECTED TO PUSH INTO THE
CAROLINAS AND NORTHEAST GEORGIA ON FRIDAY AND BECOME STATIONARY OVER
THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1105 AM EDT...THE ATMOSPHERE IS BECOMING VERY UNSTABLE ALREADY
THIS MORNING AS MOST OF THE FA IS EXPERIENCING FULL SUN. CONVECTION
IS DEVELOPING UPSTREAM OF THE FA OVER ERN KY AND WV. A LONG LIVED
MCS IS MOVING SE AT OVER 50 KTS ACROSS CENTRAL IN AND WRN OH ATTM.
I/M NOT SURE IF THIS FEATURE WILL HOLD TOGETHER AND AFFECT OUR NRN
ZONES STARTING AROUND 20 UTC...OR IF THE LEAD CONVECTION WILL
DEVELOP IT/S OWN COLD POOL AND BECOME AN MCS. HOWEVER...I/M
CONFIDENT THAT ONE OF THESE FEATURES WILL AFFECT THE FA STARTING
BETWEEN ABOUT 2 AND 3 PM. THE WRF-ARW DROPS A WELL FORMED MCS ACROSS
MOST OF THE FORECAST AREA BETWEEN 19-22 UTC. I/VE USED THIS TIMING
TO ADJUST POPS UP INTO THE CATEGORICAL RANGE ALONG THE PROBABLE MCS
PATH LATER IN THE AFTN. THE RAP 0-3 KM BULK SHEAR IS ALSO SUPPORTIVE
OF THIS AS IT INCREASES TO OVER 30 KTS OVER THE NC ZONES AND THE ERN
PART OF THE UPSTATE BY LATE AFTN. I/VE ADDED DAMAGING WIND WORDING
TO THE ZONES IN THESE AREAS AND THE HWO WILL BE PUNCHED UP AS WELL.
ALL OF THIS MATCHES WITH SPC/S 30 PERCENT DAMAGING WIND PROBS FOR
THE FORECAST AREA NORTH AND EAST OF A GREENVILLE TO ASHEVILLE LINE
FOR LATER TODAY.
AS OF 640 AM...NOT MUCH IN THE WAY OF FOG THIS MRNG SO REDUCED
MENTION MOST AREAS. TEMPS WERE TWEAKED WITH LATEST TRENDS...
OTHERWISE FCST IN GOOD SHAPE FOR THIS UPDATE.
STRONGER FLOW ALOFT...INCLUDING A SERIES OF EMBEDDED SHORTWAVES...
COMBINED WITH GOOD INSTABILITY AND STRONG INSOLATION...IS EXPECTED
TO AID THE DEVELOPMENT OF SHWRS AND TSTMS ACROSS THE AREA LATER
TODAY. BETTER SHEAR WILL INCREASE THE CHC OF SEVERE STORMS ACROSS
THE REGION AND SPC HAS PUT THE ENTIRE CWA IN A SLIGHT RISK AREA FOR
SVR STORMS TODAY. THE MAIN CONCERN WILL BE STRAIGHT-LINE WIND DAMAGE
BUT LARGE HAIL AND EVEN AN ISOLD TORNADO WILL ALSO BE PSBL THIS AFTN
AND EVE. COULD ALSO SEE AN MCS DEVELOP UPSTREAM AND DRIFT INTO THE
AREA THIS EVE. ABOVE AVG HIGHS WILL REACH INTO THE MID 90S ACROSS
THE PIEDMONT WITH A FEW UPPER 90S IN THE S ZONES. LOWER MTN VLYS
WILL WARM INTO THE MID-UPPER 80S. CONVECTION SHOULD TAPER OFF LATE
THIS EVE BUT A SLIGHT CHC WILL LINGER OVERNIGHT ACROSS THE MTNS AS
ANOTHER WEAK SHORTWAVE APPROACHES FROM THE NW. LOWS TONIGHT SHOULD
BE A COUPLE DEG ABOVE AVG.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 130 AM EDT TUESDAY...THE SHORT TERM FCST PICKS UP AT 12Z ON
WEDNESDAY WITH AN UPPER RIDGE CENTERED OVER MISSISSIPPI/ALABAMA WITH
NW FLOW ACROSS THE SOUTHERN APPALACHIAN REGION. OVER THE NEXT 24 TO
36 HRS...THE RIDGE FLATTENS A FAIR AMOUNT AS A POTENT LOOKING
SHORTWAVE...THAT IS EMBEDDED WITHIN A BROADER H5 TROF...BEGINS TO DIVE
DOWN FROM THE GREAT LAKES BY THE END OF THE PERIOD AT 12Z ON FRIDAY.
ON WEDNESDAY...A BACKDOOR COLD FRONT WILL MOVE INTO THE CENTRAL
CAROLINAS EARLY IN THE MORNING BRINGING A DECENT SURGE OF LOW TO MID
LVL MOISTURE. FORECAST SOUNDINGS CONTINUE TO DISPLAY 0 TO 6KM BULK
SHEAR VALUES ON THE ORDER OF 20 TO 30KTS OVER THE AREA WITH SFC
BASED CAPE ON THE ORDER OF 500 TO 1000 J/KG. AN MCS COULD DEVELOP TO
OUR NW AND TRACK OVER THE CAROLINAS DURING THE MORNING...WITH
REMNANT CONVECTION MOVING ACROSS THE WESTERN CAROLINAS AND NORTHEAST
GEORGIA DURING THE DAY/EVENING. SOME ORGANIZED CELLS COULD FORM THRU
THE DAY WITH SHEAR VALUES STAYING UP IN THE 20KT RANGE AND HIGH
TEMPS ABOUT A CATEGORY ABOVE NORMAL. THINGS SHOULD EVENTUALLY SETTLE
DOWN OVERNIGHT AS THE LOW LVLS COOL.
ON THURSDAY...BULK SHEAR SHOULD WEAKEN ACROSS THE REGION AS THE
UPPER FLOW BECOMES MORE WESTERLY AND HEIGHTS RISE SLIGHTLY. AT THE
SFC...A LEE TROF WILL LIKELY REMAIN ACROSS THE FCST AREA WITH WEAK
DOWNSLOPE FLOW AND DEEPER MIXING. THIS SHOULD BRING DOWN LOW LVL
DEWPTS MAKING ANY WIDESPREAD TSRA LESS LIKELY. I REDUCED POPS
OVERALL FROM THE PREVIOUS FCST AND ONLY HAVE A SOLID CHANCE OVER THE
HIGHER TERRAIN WITH SLIGHT CHANCE ELSEWHERE. HIGH TEMPERATURES
SHOULD APPROACH 90 DEGREES ACROSS THE MTN VALLEYS WITH MID TO UPPER
90S ACROSS THE LOWER ELEVATIONS.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 2 AM EDT...NO SIGNIFICANT CHANGES WERE MADE TO THE MEDIUM
RANGE FCST. STILL ANTICIPATING ANOTHER COLD FRONTAL PASSAGE ON
FRIDAY WITH SFC RIDGING MOVING IN BEHIND THE FRONT AND LINGERING
INTO NEXT WEEK.
PREVIOUS DISCUSSION...
AS OF 100 PM EDT MONDAY...THE LATEST OP MODELS AND GFS ENSEMBLE
MEMBERS ARE IN GOOD AGREEMENT FRI THROUGH THE WEEKEND WITH A OMEGA
BLOCK SETTING UP ACROSS THE NRN ATL OCEAN. THIS WILL INDUCE AND
DEEPEN ANOTHER EAST COAST TROF AND ALLOW A COLD FRONT INTO THE
AREA BY SAT. THE FRONT IS EXPECTED TO STALL ACROSS THE CWFA SAT
THROUGH SUN AND PERHAPS LIFT A LITTLE NORTH ON MON. THE STRONGEST
UPPER FORCING WILL REMAIN NORTH OF THE AREA...HOWEVER GOOD OVERALL
DYNAMICAL LIFT AND H3 DIV ALONG WITH PLENTY OF LLVL INSTABILITY WILL
BE AVAILABLE FOR STRONG TO SEVERE DIURNAL TSTMS EACH DAY EXPECT
PERHAPS SUN. NOCTURNAL ACTIVITY IS ALSO PROBABLE FRI/SAT NIGHT WITH
THE FROPA LATE FRI AND A REINFORCING S/W PUSHING IN LATE SAT. POPS
WERE MAINTAINED AT NEAR CLIMO...HOWEVER IF THIS PATTERN AND S/W
TIMING PERSISTS OVER THE NEXT COUPLE MODEL RUNS...AN INCREASE IN
POPS WILL BE WARRANTED FOR FRI/SAT. SUN LOOKS TO BE THE DRIEST DAY
WITH FAIRLY STRONG HIGH PRESSURE BUILDING IN...YET THE FRONT WILL BE
SHUNTED JUST TO THE SOUTH...SO SLIGHT CHANCE POPS WERE CARRIED
THROUGH THE DAY. MON WILL BE ACTIVE AGAIN AS ANOTHER SHOT OF UPPER
ENERGY ROUNDS THE WRN RIDGE AND TRAVERSES THE REGION. MAX AND MIN
TEMPS WILL BE RIGHT AROUND OR PERHAPS A COUPLE DEGREES ABOVE NORMAL
FRI/SAT. WITH NW/LY FLOW SETTING UP SUN...EXPECT A COUPLE DEGREES
COOLER IN THE MTNS SUN AND PERHAPS EVEN MON. YET...A GOOD DOWNSLOPE
WARMING COMPONENT WILL ENABLE MAXES RIGHT AROUND NORMAL OVER THE
NON/MTNS BOTH SUN AND MON.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
AT KCLT AND ELSEWHERE...ANY PATCHY FOG THAT DEVELOPS SHOULD
DISSIPATE QUICKLY THIS MRNG...THEN CUMULUS WILL INCREASE AND BUILD
IN THE AFTN WITH AT LEAST SCT TSTMS ACROSS THE CWA BY MID-LATE AFTN.
ALL LOCATIONS GET A PROB30 FOR TSTMS TIL 00Z BUT EXPECT ISOLD-SCT
CONVECTION THIS EVE. LGT WINDS EARLY WILL PICK UP WITH MIXING FROM W
TO NW BY AFTN AT 7-10KT.
OUTLOOK...EXPECT SOLID CHC CONVECTION WED AS A COUPLE WEAK
SHORTWAVES MOVE INTO THE AREA FROM THE NW. BEST CHC OF OVERNIGHT
RESTRICTIONS WILL BE IN AREAS THAT SEE LOCALLY HEAVY RAIN. A
STRONGER SHORTWAVE AND ASSOC COLD FRONT MAY BRING MORE WIDESPREAD
CONVECTION THIS WEEKEND.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JPT
NEAR TERM...MCAVOY
SHORT TERM...JPT
LONG TERM...JPT
AVIATION...RB
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1000 AM CDT TUE JUL 24 2012
.UPDATE...HOISTED HEAT ADVISORY FOR WEDNESDAY. IMPRESSIVELY HOT
THERMAL AXIS DRIVES INTO SRN WI. 925 TEMPS SOAR INTO THE LOW TO
MID 30S AND 850 TEMPS 26-29C...VERY CONDUCIVE TO OPPRESSIVELY HOT
TEMPERATURES. HIGHER DEW POINTS EXPECTED...UPPER 60S/LOW 70S. NAM
DEWS WHICH HAVE BEEN BETTER OF LATE ARE EVEN SUGGESTING SOME DEWS
NEAR 70. GFS DEWS IN MID 70S...TYPICALLY TOO MOIST...THOUGH BL
LAYER BECOMING MORE FAVORABLE FOR HIGHER DEWS WITH THE RECENT
RAINS IN SOME AREAS.
PC
&&
.PREV DISCUSSION... /ISSUED 339 AM CDT TUE JUL 24 2012/
TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM
DIMINISHING TREND NOTED IN CONVECTION OVER SOUTHWEST WI OVER LAST
HOUR OR SO. SCATTERED TO NUMEROUS CONVECTION EXTENDS WELL TO THE
WEST ACROSS SOUTHERN MN INTO EASTERN SODAK. HOWEVER FRONTAL
BOUNDARY SAGGING ACROSS SOUTHERN WI ATTM...WL CONTINUE INTO NRN IL
EARLY THIS MRNG. THIS WILL TIGHTEN THE BAROCLINICITY ACROSS
SOUTHERN WI AND INCREASE THE LOW LEVEL FN VECTOR RESPONSE TO
FRONTOGENESIS. THIS SHOULD HELP CONTINUE THE SCATTERED TO NUMEROUS
CONVECTION OVER PORTIONS OF SOUTHERN WISCONSIN THROUGH MID-MORNING
BEFORE DIMINISHING. PWAT VALUES IN THE 1.75 TO 2.0 INCH
RANGE...WHICH IS ABOUT 160 PERCENT OF NORMAL. BOTH THE RAP AND
NAM40KM SHOW LAYER FWF LINGERING OVER SOUTH CENTRAL WI TO AROUND 15Z
BEFORE DIMINISHING. HENCE WL CONTINUE LIKELY WORDING IN THE SOUTH
CENTRAL AREAS...DIMINISHING TO CHC/SCT IN THE NORTHEAST.
UPSTREAM SHORT WAVE OVER ERN SODAK IS EXPECTED TO MOVE ESE ACROSS
SRN MN INTO SRN WI LATER THIS MRNG...SO WL CONTINUE CHANCE INTO THE
LATE MORNING. SHORT WAVE AND FRONTOGENETICAL FORCING WEAKENS AND
SLIDES SOUTHEAST FOR THE AFTN.
STRONG SURGE OF RETURN FLOW AND LOW LEVEL THETA-E ADVECTION
ACCOMPANY DEVELOPING LOW LEVEL JET TONIGHT. FOCUS OF LLJ TO THE
NORTHWEST OF CWA...HOWEVER STILL GET CLIPPED BY INCREASING WARM AIR
ADVECTION. HENCE WL CONTINUE LIKELY POPS IN THE NORTH TONIGHT.
WEDNESDAY AND THURSDAY...FORECAST CONFIDENCE...MEDIUM
CONVECTION NEAR WARM FRONT SHOULD WIND DOWN WEDNESDAY MORNING ACROSS
THE NORTHERN FORECAST AREA. WARM FRONT THEN EXPECTED TO LINGER JUST
NORTH OF THE CWA THROUGH THE DAY. MODELS INDICATING THAT TEMPS WILL
SOAR IN THE WARM SECTOR...WITH 925 MB TEMPS UP TO AROUND 32C ON THE
ECMWF AND EVEN WARMER WITH THE NAM. CONCERN IS CERTAINLY THERE THAT
OVERNIGHT CONVECTION MAY KEEP THE WARM FRONT FARTHER SOUTH...AND
THEN ALSO PULL IN COOLER AIR OFF THE LAKE NORTH OFF THE FRONT. FOR
NOW THOUGH...WENT WITH WHAT THE MODELS ARE SHOWING AND BUMPED TEMPS
UP TO AROUND 100 MOST PLACES...EXCEPT FOR IN THE NORTH TOWARD THE
WARM FRONT. TOO MUCH UNCERTAINTY WITH LINGERING CONVECTION/CLOUDS
AND PLACEMENT OF THE WARM FRONT...SO HELD OFF ON HEAT ADVISORY FOR
NOW. WILL EVENTUALLY NEED ONE IF MODELS CONTINUE DOWN THIS ROAD AND
FORECAST CONFIDENCE INCREASES. EVEN WITH DEWPOINTS MIXING INTO THE
MID AND UPPER 60S...TEMPS AROUND 100 WOULD RESULT IN HEAT INDICES IN
THE 100-105 RANGE.
CONVECTION WITH THE TRAILING COLD FRONT IS EXPECTED TO MAINLY HOLD
OFF UNTIL THE EVENING AND OVERNIGHT HOURS. WITH 30 KT LLJ ACROSS THE
AREA AND CAPES IN EXCESS OF 1000 J/KG...STILL THINKING STORMS SEVERE
STORMS ARE A POSSIBILITY AND SPC IS MAINTAINING A SLIGHT RISK.
KEPT SOME POPS THURSDAY MORNING...AS THE ECMWF LINGERS POST FRONTAL
PRECIP. OTHERWISE...SHOULD MAINLY BE DRY THURSDAY. A WEAK WAVE MAY
BRING A FEW MORE SHOWERS/STORMS TO THE AREA LATER IN THE DAY AND
OVERNIGHT.
THINKING THE SUN MAY POKE OUT FOR A TIME THURSDAY...SO PUSHED HIGHS
UP INTO THE MID AND UPPER 80S PER 925 MB TEMPS IN THE 22-25C RANGE.
FRIDAY AND SATURDAY...FORECAST CONFIDENCE...MEDIUM
PRECIP MAY LINGER INTO FRIDAY MORNING AS THE SHORTWAVE EXITS...WITH
DRY WEATHER EXPECTED SATURDAY AS SFC HIGH PRESSURE MOVES OVERHEAD.
SHOULD SEE HIGHS COMFORTABLY NEAR NORMAL BOTH DAYS.
SUNDAY AND MONDAY...FORECAST CONFIDENCE...MEDIUM
WITH UPPER RIDGE BUILDING IN TO THE WEST SUNDAY AND
MONDAY...COMBINATION OF WARM AIR ADVECTION AND A WEAK WAVE OR TWO
MAY KICK OFF SHOWERS/STORMS AT TIMES. WILL LIKELY SEE TEMPS START TO
WARM BACK UP.
AVIATION/12Z TAFS/...SCATTERED TO NUMEROUS CONVECTION LIKELY THIS
MORNING WITH MOST NUMEROUS CONVECTION TOWARDS KMSN. ENOUGH RAINFALL
TO MOISTEN LOW LEVELS EXPECTED TO PRODUCE PERIOD OF MVFR CIGS AT
KMSN. NOT AS CONFIDENT ON LOW CIGS FARTHER EAST WHERE RAINFALL MAY
BE A BIT MORE SCATTERED. MAY USE A TEMPO GROUP WITH 12Z ISSUANCE.
ANY LOWER CIGS SHOULD LIFT TO VFR THIS AFTN AS FORCING SLIDES SOUTH
OF AREA AND SLIGHTLY DRIER AIR GETS PULLED INTO THE LOWER LEVELS.
MORE SCT CONVECTION TONIGHT WITH STRONG RETURN FLOW.
MARINE...ONE TO TWO HOURS OF GUSTY NORTHEAST WINDS ACCOMPANIED
FROPA AS IT MOVED SOUTH ALONG THE LAKE MICHIGAN SHORE EARLY THIS
MORNING. THE FRONT WILL CONTINUE SAGGING SOUTHWARD WITH NORTHEAST
WINDS SETTLING DOWN TO 5 TO 15 KNOTS. SCATTERED T TO AFFECT NEAR
SHORE WATERS THIS MORNING AND AGAIN LATER TNGT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...HEAT ADVISORY FROM 11 AM TO 9 PM CDT WEDNESDAY FOR WIZ051-052-
058>060-062>072.
HEAT ADVISORY FROM 11 AM TO 7 PM CDT WEDNESDAY FOR WIZ046-047-
056-057.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...MBK
WEDNESDAY THROUGH MONDAY...DDV
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
622 AM CDT TUE JUL 24 2012
.SHORT TERM...TODAY THROUGH THURSDAY
330 AM CDT TUE JUL 24 2012
FORECAST CONCERNS ARE ON SHOWER AND THUNDERSTORM CHANCES TODAY
THOUGH THURSDAY...WITH THE POTENTIAL FOR A ROUND OF SEVERE
THUNDERSTORMS THIS AFTERNOON WEST OF THE MISSISSIPPI RIVER...THEN
ACROSS THE ENTIRE AREA ON WEDNESDAY. ADDITIONAL CONCERNS ARE ON
HEAT INDEX VALUES WEDNESDAY AFTERNOON...WHEN INDICES COULD CLIMB
TO AROUND 105 FOR LOCATIONS ALONG AND SOUTH OF INTERSTATE 90.
LATEST RADAR IMAGERY SHOWED A BAND OF SHOWERS AND THUNDERSTORMS
EXTENDING FROM FAR NORTHEAST SOUTH DAKOTA...THROUGH CENTRAL
MINNESOTA TO ALONG THE MISSISSIPPI RIVER INTO FAR SOUTHWEST
WISCONSIN. BRIEF HEAVY DOWNPOURS AND WIND GUSTS IN THE 30 TO 40 KT
RANGE HAVE BEEN REPORTED WITH SOME OF THE STORMS.
SHOWERS AND THUNDERSTORMS WILL BE ONGOING THIS MORNING ACROSS
PORTIONS OF SOUTHEAST MINNESOTA...NORTHEAST IOWA AND SOUTHWEST AND
WEST CENTRAL WISCONSIN AS STRONG 850 MB MOISTURE TRANSPORT IS
FOCUSED ALONG AND WEST OF THE MISSISSIPPI RIVER. THE LOW LEVEL JET
WILL START TO SUBSIDE THIS MORNING WITH THE SHOWERS AND STORMS
GRADUALLY TAPERING OFF AND SHIFTING TO THE SOUTHEAST. A WARM FRONT
WILL BE POSITIONED FROM SOUTHWEST MINNESOTA INTO NORTHEAST IOWA..AND
NORTHERN ILLINOIS THIS AFTERNOON. THE FRONT WILL BE THE FOCUS FOR
SHOWER AND THUNDERSTORM DEVELOPMENT THIS AFTERNOON INTO TONIGHT AS
IT LIFTS NORTHEAST AS SURFACE LOW PRESSURE DEEPENS OVER SOUTHEAST
SOUTH DAKOTA. AFTERNOON MUCAPE VALUES INCREASE INTO THE 2500-3500
J/KG RANGE BY 21Z THIS AFTERNOON. 0-6 KM BULK SHEAR WILL BE AROUND
40 KTS THIS AFTERNOON LEADING TO THE POTENTIAL FOR A FEW STRONG TO
SEVERE THUNDERSTORMS. HOWEVER...THERE WILL BE A VERY STRONG CAP IN
PLACE WITH 850 MB TEMPERATURE CLIMBING TO INTO THE MID 20S LATE
THIS AFTERNOON INTO THIS EVENING. THINKING THAT CONVECTION WILL
LIKELY WAIT TO FIRE UNTIL THIS EVENING AS MOISTURE TRANSPORT AND
STRONG 850 MB WARM AIR ADVECTION RAPIDLY INCREASE...LEADING TO
WIDESPREAD ELEVATED CONVECTION. AT THIS TIME IT APPEARS THE
SHOWERS AND STORMS SHOULD FIRE ACROSS SOUTHEAST MINNESOTA INTO
SOUTHWEST WISCONSIN THIS EVENING...WITH THE HIGHEST CHANCES NORTH
OF A LINE FROM ROCHESTER MN...TO LA CROSSE TO RICHLAND CENTER. THE
NAM SUGGESTS THE BULK OF THIS ACTIVITY SHOULD FIRE ALONG AND EAST
OF THE MISSISSIPPI RIVER...SO WILL HAVE TO KEEP A CLOSE WATCH ON
THIS. PRECIPITATION CHANCES MAY NEED TO BE FOCUSED MORE ACROSS
THESE AREAS DURING THE OVERNIGHT HOURS. FORECAST SOUNDINGS SHOW
AROUND 1500 J/KG ELEVATED CAPE WHEN LIFTING FROM 800 MB. OVERALL
SHEAR LOOKS MARGINAL WITH 1-6 KM BULK SHEAR OF 30 TO 38 KTS. COULD
SEE SOME MARGINALLY SEVERE HAIL TONIGHT WITH SOME OF THE STORMS
AND POSSIBLY SOME GUSTY WINDS. THE MAIN THREAT LOOKS TO BE BRIEF
HEAVY RAIN AND FREQUENT LIGHTNING. THE HIGHEST CHANCES FOR STRONG
TO SEVERE STORMS WOULD BE MAINLY ALONG AND EAST OF THE MISSISSIPPI
WHERE SHEAR IS A LITTLE STRONGER.
THE WARM FRONT IS EXPECTED TO PUSH INTO NORTHERN WISCONSIN WEDNESDAY
MORNING AS SURFACE LOW PRESSURE MOVES INTO SOUTHWEST MINNESOTA. THIS
WILL LEAVE MUCH OF THE FORECAST AREA IN THE WARM SECTOR FROM
WEDNESDAY MORNING INTO WEDNESDAY AFTERNOON. HOT AIR WILLS SURGE
NORTH INTO THE AREA...WITH TEMPERATURES EXPECTED TO CLIMB INTO THE
MID TO UPPER 90S. A FEW LOCATIONS ACROSS NORTHEAST IOWA AND FAR
SOUTHWEST WISCONSIN COLD REACH THE 100 DEGREE MARK. THIS SURGE OF HOT
AIR WILL LEAD TO HEAT INDEX CONCERNS. THE DEWPOINTS MAY MIX OUT
DURING THE DAY BUT SHOULD AT LEAST HOLD IN THE 60S. EVEN IF THE
DEWPOINTS FALL AS FORECAST SOUNDINGS SUGGEST...WITH INVERTED V TYPE
SOUNDINGS...WILL STILL SEE THE HOT TEMPERATURES SURGE INTO THE AREA.
A HEAT ADVISORY WILL LIKELY BE NEEDED ON WEDNESDAY. A COLD FRONT IS
EXPECTED TO PUSH INTO THE ARE FROM THE NORTHWEST WEDNESDAY
AFTERNOON. HOW FAR SOUTH THIS FRONT GETS DURING THE AFTERNOON HOURS
WILL DETERMINE WHAT AREAS WILL EXPERIENCE THE HOTTEST TEMPERATURES.
CURRENT THINKING IS THAT AREAS ALONG AND SOUTH OF INTERSTATE 90 WILL
NEED A HEAT ADVISORY WEDNESDAY AFTERNOON...WHERE HEAT INDEX VALUES
ARE EXPECTED TO CLIMB INTO THE 100-105 DEGREE RANGE. WILL HAVE TO
KEEP A CLOSE WATCH ON THE WARM FRONT ON WEDNESDAY FOR THE OUTSIDE
CHANCE OF AN ISOLATED TORNADO...ESPECIALLY FOR LOCATIONS ALONG AND
NORTH OF I-94. THE SURFACE LOW IS EXPECTED TO PUSH INTO SOUTHEAST
MINNESOTA EARLY WEDNESDAY AFTERNOON. 0-1 KM SHEAR INCREASES INTO THE
20 TO 30 KT RANGE BY 18Z ALONG AND NORTH OF I-94...WITH MLCAPE
VALUES CLIMBING TO AROUND 2500 J/KG RIGHT ALONG THE WARM FRONT. LCL
HEIGHTS REALLY CLIMB IN THE WARM SECTOR DURING THE AFTERNOON HOURS
BUT FEEL THERE IS THE POTENTIAL FOR THE WARM FRONT TO STALL A LITTLE
FURTHER SOUTH THAN MODEL GUIDANCE SUGGEST WITH AN MCS ROLLING ACROSS
FAR NORTHERN WISCONSIN POTENTIALLY PUSHING AN OUT FLOW BOUNDARY
SOUTHWARD STALLING THE FRONT. ANOTHER FACTOR LEANING AGAINST STORMS
DEVELOPING NEAR THE WARM FRONT IS A STRONG CAP IN PLACE...WITH
SURFACE BASED CIN OF NEARLY NEGATIVE 300 J/KG. THE COLD FRONT WILL
DRIFT SOUTHEAST ACROSS THE FORECAST AREA THROUGH THE AFTERNOON WITH
SHOWERS AND THUNDERSTORMS DEVELOPING ALONG THE FRONT. THE STRONGEST
SHEAR TO SUPPORT ORGANIZED CONVECTION WILL BE LOCATED RIGHT ALONG
AND BEHIND THE FRONT. THE INVERTED V TYPE SOUNDINGS IN THE WARM
SECTOR LEAD TO DAMAGING WIND CONCERNS WITH ANY THUNDERSTORMS THAT
MAY DEVELOP ALONG THE FRONT. GIVEN THE STRONG INSTABILITY THAT
DEVELOPS WEDNESDAY AFTERNOON...MUCAPE AROUND 3000 J/KG CANNOT RULE
OUT SOME LARGE HAIL WITH THE STORMS WEDNESDAY AFTERNOON.
THE COLD FRONT IS EXPECTED TO MOVE INTO SOUTHERN IOWA AND CENTRAL
IOWA LATE WEDNESDAY NIGHT WITH SHOWER AND THUNDERSTORM CHANCES
SHIFTING SOUTH OF THE FORECAST AREA LATE. A POTENT UPPER LEVEL
TROUGH WILL DIVE INTO NORTHERN MINNESOTA EARLY THURSDAY MORNING AND
IS EXPECTED TO PROGRESS SOUTHEAST INTO NORTHWEST BY EARLY THURSDAY
AFTERNOON. THE TROUGH WILL MOVE INTO THE FORECAST AREA LATE THURSDAY
AFTERNOON INTO EARLY THURSDAY EVENING BRINGING A CHANCE OF SHOWERS
AND THUNDERSTORMS TO THE AREA. FORECAST SOUNDINGS SHOW SURFACE BASED
CAPE INCREASING TO AROUND 1500 J/KG AHEAD OF THIS WAVE. 0-6 KM BULK
SHEAR IS EXPECTED TO BE AROUND 40 KTS...SO THINKING THERE COULD BE
ORGANIZED CONVECTION DURING THE AFTERNOON HOURS. THE STRONGEST
FORCING ALOFT PASSES OVER NORTHERN AND NORTH CENTRAL WISCONSIN SO
HIGHEST THUNDERSTORM CHANCES WILL BE ACROSS THESE AREAS. WILL HAVE
TO KEEP A CLOSE EYE ON THE NEXT FEW MODEL RUNS WITH THE POTENTIAL
FOR A FEW SEVERE STORMS THURSDAY AFTERNOON. HIGHS ON THURSDAY WILL
BE MORE SEASONABLE WITH TEMPERATURES RANGING FROM THE LOWER 80S
ACROSS NORTHERN WISCONSIN TO THE UPPER 80S OVER NORTHEAST IOWA.
.LONG TERM...FRIDAY THROUGH MONDAY
330 AM CDT TUE JUL 24 2012
24.00 FORECAST MODELS ARE IN AGREEMENT FRIDAY THROUGH SATURDAY
INDICATING SURFACE NORTHWEST FLOW ALOFT AND SURFACE HIGH PRESSURE IN
PLACE ACROSS THE UPPER MISSISSIPPI RIVER VALLEY. PLAN ON VERY
COMFORTABLE TEMPERATURES ON FRIDAY WITH HIGHS RANGING FROM THE MID 70S
ACROSS NORTHERN WISCONSIN TO AROUND 80 OVER NORTHEAST IOWA. ANOTHER
PLEASANT DAY IS ANTICIPATED ACROSS THE REGION ON SATURDAY WITH
MOSTLY SUNNY SKIES AND HIGHS IN THE 80S. A WEAK EMBEDDED SHORTWAVE
WILL MOVE INTO THE REGION LATE SATURDAY NIGHT INTO SUNDAY BRINGING A
CHANCE OF SHOWERS AND THUNDERSTORMS TO THE AREA. SHOWER AND
THUNDERSTORM CHANCES WILL CONTINUE THROUGH MONDAY AS WEAK UPPER LEVEL
SHORTWAVES MOVE ACROSS THE UPPER MIDWEST. TEMPERATURES LOOK TO HOVER
AROUND SEASONAL VALUES WITH HIGHS RANGING FROM THE LOWER TO UPPER
80S.
&&
.AVIATION...TODAY AND TONIGHT
622 AM CDT TUE JUL 24 2012
REGIONAL RADARS INDICATE THE BAND OF SHOWERS AND THUNDERSTORMS
EXTENDS BACK INTO CENTRAL MINNESOTA AND THEN BECOMES MORE
SCATTERED IN NATURE ACROSS WESTERN MINNESOTA INTO EASTERN SOUTH
DAKOTA. WOULD EXPECT THIS ACTIVITY TO CONTINUE PROPAGATING
SOUTHEAST THIS MORNING WITH THE BACK EDGE DIMINISHING AS THE LOW
LEVEL JET CONTINUES TO TURN AND BECOME MORE OUT OF THE SOUTHWEST
TO WEST. THE 24.08Z HRRR LOOKS TO HAVE A GOOD HANDLE ON THE
CURRENT ACTIVITY AND MAINTAINS A PRETTY SOLID BAND THROUGH ABOUT
14Z AND THEN QUICKLY DIMINISHES IT BETWEEN 14 AND 16Z. THIS MAKES
SENSE AS THE 24.06Z NAM INDICATES THE SHORT WAVE TROUGH SHOULD BE
MOVING OFF TO THE EAST ABOUT THEN. WILL CARRY CATEGORICAL SHOWERS
AT BOTH TAF SITES INTO THE MID MORNING AND THEN DROP BACK TO VCSH.
THE WARM FRONT TO THE SOUTH WILL MOVE SLOWLY NORTH TONIGHT BUT IS
NOT EXPECTED TO MOVE THROUGH EITHER TAF SITE BY 12Z. AS THE NEXT
SHORT WAVE TROUGH COMES OUT AND THE LOW LEVEL JET INTERSECTS THE
FRONT TONIGHT...ANOTHER ROUND OF SHOWERS AND STORMS IS EXPECTED TO
DEVELOP. MOST OF THIS ACTIVITY LOOKS TO BE NORTH OF THE TAF SITES
WITH KLSE POSSIBLY HAVING A CHANCE OF SEE SOME SCATTERED ACTIVITY.
DID NOT INCLUDE ANY CONVECTION FOR KRST AS THE MID LEVEL WARM AIR
LOOKS TO COME IN AND CAP OFF THAT AREA.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
330 AM CDT TUE JUL 24 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...04
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
901 AM MST TUE JUL 24 2012
.SYNOPSIS...
THUNDERSTORM CHANCES WILL BEGIN TO DECREASE OVER THE NEXT FEW DAYS
AS DRIER AIR SLOWLY WORKS IN FROM THE WEST. AFTER TODAY...STORM
CHANCES WILL MAINLY BE CONFINED TO THE HIGHER TERRAIN AREAS EAST OF
PHOENIX. DRIER AND SLIGHTLY WARMER WEATHER WILL SETTLE ACROSS THE
REGION FOR LATE THIS WEEK INTO THE WEEKEND...BEFORE A MORE ACTIVE
MONSOON PATTERN IS POSSIBLE BY THE EARLY PART OF NEXT WEEK.
&&
.DISCUSSION...
OVERNIGHT SCATTERED SHOWERS AND THUNDERSTORMS MAINLY EAST OF PHOENIX
CONTINUE TO REDEVELOP ACROSS FAR NORTHERN PINAL AND SOUTHERN GILA
COUNTIES. A SIGNATURE OF AN MCV CAN BE SEEN ON RADAR EARLIER THIS
MORNING OVER GILA COUNTY...WHILE THE LATEST 12Z NAM SHOWS A SMALL
500 MB CIRCULATION CENTERED OVER EAST-CENTRAL ARIZONA. DECENT
700-500 MB OMEGA FROM A FLAGSTAFF TO JUST EAST OF PHOENIX LINE AND
EAST...ALONG WITH A GOOD LOW LEVEL MOISTURE GRADIENT CONTINUE TO
FUEL THE ONGOING CONVECTION. COULD CONTINUE TO SEE SHOWERS REDEVELOP
INTO THE LATE MORNING HOURS ACROSS PINAL AND GILA COUNTIES DEPENDING
ON HOW QUICKLY THE MCV MOVES EASTWARD. THIS ACTIVITY WILL LIKELY
HINDER CHANCES LATER TODAY AS THE EXTENSIVE CLOUD DECK WILL BE SLOW
TO BURN OFF IF IT ACTUALLY EVER DOES. INCREASED POPS EAST OF PHOENIX
IN THE NEAR-TERM...AND WILL HAVE TO KEEP MONITORING THE SITUATION
FOR ANY FURTHER ADJUSTMENTS NEEDED FOR THIS AFTERNOON.
ELSEWHERE...NORTHWESTERLY FLOW AND DRY AIR IS WORKING IT/S WAY
EASTWARD THROUGH WESTERN ARIZONA AND WILL LIKELY PUSH INTO MUCH OF
CENTRAL ARIZONA THIS AFTERNOON. AFTERNOON SLIGHT CHANCE POPS ACROSS
PORTIONS OF SOUTHWEST AND SOUTH-CENTRAL ARIZONA ARE STILL LOOKING
GOOD. THERE SHOULD BE ENOUGH HEATING AND RESIDUAL MOISTURE TO SPARK
OFF A FEW SHOWERS AND THUNDERSTORMS ACROSS HIGHER TERRAIN AREAS OF
THE LOWER DESERTS THIS AFTERNOON. HOWEVER...WARMING IN THE MID
LEVELS AND THE DRYING NORTHWESTERLY FLOW WILL DEFINITELY HINDER
DEVELOPMENT AREAS WEST OF MARICOPA COUNTY TODAY.
&&
.PREVIOUS DISCUSSION...
CONVECTION CONTINUES FROM GILA TO YAVAPAI COUNTIES THIS
MORNING...SENDING OUTFLOWS INTO THE VALLEY AND SPAWNING ISOLATED
SHOWERS AND THUNDERSTORMS AS FAR WEST AS THE ESTRELLA MOUNTAINS AS
OF 2 AM. NOT MUCH IN THE WAY OF SEVERE WEATHER PER SE...BUT THERE
HAVE BEEN REPORTS OF NEARLY 2 INCHES OF RAIN SINCE APPROX 10PM LAST
EVENING WITH THE STRONGEST STORMS. ONLY THE HRRR MODEL HAS ANY SENSE
OF WHATS GOING ON AT THE MOMENT...SHOWING STORMS DIMINISHING AROUND
12Z. WITH THIS IN MIND...I WILL MAINTAIN A CHANCE OF SHOWERS AND
THUNDERSTORMS IN THE FORECAST THROUGH THE PRE-DAWN HOURS EAST OF
PHOENIX.
ONGOING CONVECTION AND NUMEROUS OUTFLOWS ARE WREAKING HAVOC ON OUR
PRECIP CHANCES FOR LATER TODAY. ATMOSPHERE REMAINS PRIMED FOR
CONVECTION AT THE MOMENT PROVIDED THERE IS ENOUGH FORCING IN
PLACE...BUT MOISTURE WILL BEGIN ERODING FROM THE WEST LATER THIS
AFTERNOON AND CONSEQUENTLY...INSTABILITY IS EXPECTED TO DIMINISH
RAPIDLY BY 00Z. ON TOP OF THAT...THE ATMOSPHERE WILL ALMOST
CERTAINLY BE WORKED OVER ACROSS THE HIGHER TERRAIN. WHILE IT APPEARS
THERE IS STILL A CHANCE OF STORMS LATER TODAY...I HAVE REDUCED POPS
GIVEN THE ABOVE CONCERNS. AREAL COVERAGE AND EXTENT OF STORMS WOULD
HAVE BEEN LESSER TODAY ANYWAY GIVEN ERODING MOISTURE BUT I THINK
THIS OVERNIGHT COMPLEX WILL LESSEN COVERAGE EVEN MORE.
A BIT OF A BREAK FROM THE MONSOON LOOKS LIKELY FROM WEDNESDAY
THROUGH SATURDAY AS MOISTURE DECREASES AND INSTABILITY DROPS TO
NOTHING. PRECIP CHANCES WERE CHANGED ONLY SLIGHTLY EACH
DAY...GENERALLY CLIMO MINUS 10 OR 15 PERCENT. SOME SUGGESTION OF AN
EASTERLY WAVE/INVERTED TROUGH MOVING THROUGH THE AREA LATE THIS
WEEKEND INTO EARLY NEXT WEEK. WITH THIS IN MIND...I STARTED BRINGING
POPS BACK INTO THE DESERTS ON SUNDAY AND MONDAY ALTHOUGH FIGURING
OUT THE EXACT TIMING THIS FAR IN ADVANCE IS TRICKY AT BEST.
&&
.AVIATION...
SOUTH CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
SHOWER AND THUNDERSTORM ACTIVITY OVER HIGHER TERRAIN NORTH AND EAST
OF THE PHOENIX AREA IS FINALLY TRENDING DOWN EARLY THIS MORNING.
SOME ISOLATED WEAK SHOWERS MAY STILL POP UP OVER THE METRO AREA
BEFORE 16Z BUT TOO LOW A PROBABILITY TO INCLUDE IN THE TAFS.
ANTICIPATE THUNDERSTORM ACTIVITY TO FLIRT WITH THE METRO AREA ONCE
AGAIN LATER TODAY AND TONIGHT WITH OUTFLOW WINDS CAUSING ERRATIC
WIND SHIFTS. NO WIDESPREAD STORM DEVELOPMENT IS ANTICIPATED OVER THE
METRO BUT STORMS CAN BE EXPECTED AFTER 23Z NEAR THE FOOTHILLS.
CONFIDENCE IN STORM OCCURRENCE AT THE TAF SITES NOT HIGH ENOUGH AT
THIS TIME TO INSERT TEMPO/PROB TSRA IN THE TAFS. OTHERWISE...WINDS
WILL BE LIGHT AND FAVOR TYPICAL DIURNAL PATTERNS.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
VERY ISOLATED SHOWERS OVER SOUTHEAST CALIFORNIA ARE ANTICIPATED TO
DISSIPATE BY 15Z AND MAY DRIFT OVER KBLH. OTHERWISE...STORM ACTIVITY
LATER TODAY IS EXPECTED TO BE EAST OF THE LOWER COLORADO RIVER
VALLEY. ANTICIPATE WINDS TO FOLLOW A SIMILAR PATTERN TO THE PREVIOUS
24 HOURS WITH AFTERNOON GUSTS A BIT STRONGER AT KBLH THAN YESTERDAY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
ATMOSPHERIC MOISTURE AND ASSOCIATED THUNDERSTORM ACTIVITY IS
EXPECTED TO BEGIN TRENDING UPWARD LATE THIS WEEK INTO EARLY NEXT
WEEK AS A WEATHER DISTURBANCE TRACKS WESTWARD ACROSS FAR NORTHERN
MEXICO. ACCORDINGLY...HUMIDITIES WILL TREND SLOWLY UPWARD FROM EAST
TO WEST. APART FROM THUNDERSTORMS...WINDS ARE EXPECTED TO FOLLOW
FAMILIAR WARM SEASON DIURNAL PATTERNS. THUNDERSTORM CHANCES ARE
EXPECTED TO REMAIN PRIMARILY EAST OF THE LOWER COLORADO RIVER
VALLEY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...KUHLMAN
PREVIOUS DISCUSSION...LEINS
AVIATION...AJ
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
1017 AM PDT TUE JUL 24 2012
.SHORT TERM DISCUSSION...
THE UPPER LOW WHICH BROUGHT CONVECTION OVER THE PAST FEW DAYS IS
WEAKENING AND SHIFTING EAST OF THE AREA. WATER VAPOR IMAGERY
SHOWS DRY SOUTHWEST FLOW SETTING UP OVER REGION. SOME MOISTURE
LINGERS OVER THE FAR NORTHERN SIERRA AND THE BURNEY BASIN BUT EVEN
THIS SHOULD BE EXITING LATER TODAY. A PERSISTENT UPPER LEVEL
PATTERN OF COASTAL TROUGHING AND INLAND RIDGING WILL SET UP AND
CONTINUE FOR MUCH OF THE FORECAST PERIOD.
VISIBLE SATELLITE SHOWS A CONSIDERABLE MARINE LAYER ALONG THE
COAST. THE FORT ORD PROFILER HAS THE MARINE LAYER ABOUT 2200 FEET
THICK. STRATUS THIS MORNING SPREAD ONLY INTO THE DELTA WEST OF
FAIRFIELD. WITHOUT A SIGNIFICANT SHORTWAVE TROUGH INCURSIONS OF
MARINE AIR SHOULD BE RELATIVELY LIMITED FOR THE REST OF THE WORK
WEEK. THE DELTA BREEZE BROUGHT COOL AIR INTO THE DELTA/SOUTHERN
SACRAMENTO VALLEY THIS MORNING. THIS IS EXPECTED TO STRENGTHEN
AGAIN OVERNIGHT KEEPING ADJACENT AREAS FAIRLY COOL.
THE MAIN ISSUE FOR TODAY IS THE POTENTIAL FOR AN ISOLATED SHOWER
OR THUNDERSTORM OVER THE BURNEY BASING AREA. THE WRF ARW IS SHOWING
SOME CONVECTION DEVELOPING THERE IN THE EARLY AFTERNOON BUT THIS
IS QUITE LIKELY OVERDONE AS THE TROUGH IS MOVING OUT FAIRLY
QUICKLY. THE LATEST HRRR AND NAM12 MODELS ARE SHOWING THE AIRMASS
DRYING AND BECOMING STABLE OVER THE FORECAST AREA. WILL CONSIDER
PULLING OUT THE ISOLATED SHOWERS/THUNDERSTORMS BUT FOR THE MOMENT
WILL KEEP THEM IN THE FORECAST. OTHERWISE...THE FORECAST LOOKS
DRY FOR TODAY.
HIGHS TODAY WILL BE A COUPLE DEGREES BELOW NORMAL. TEMPERATURES
SHOULD TREND DOWN A LITTLE MORE THROUGH FRIDAY. WARMING TO NEAR
NORMAL IS EXPECTED FOR THE WEEKEND AS RIDGING BUILDS. HIGHS MAY
REACH A LITTLE ABOVE NORMAL EARLY NEXT WEEK. EK
.EXTENDED DISCUSSION (SATURDAY THROUGH TUESDAY)
THE EXTENDED PERIOD WILL FEATURE SOUTHWEST FLOW ALOFT OVER NORCAL
WITH WEAK TROUGHING OFF THE WEST COAST AND A RIDGE OVER THE
INTERMOUNTAIN WEST. EXTENDED MODELS ATTEMPT TO ROTATE WEAK
SHORTWAVES AT TIMES THROUGH THE FLOW AND INTO NORCAL...ALTHOUGH
THEY CURRENTLY HAVE NO CONSENSUS ON TIMING. TEMPERATURES LOOK
SEASONAL WITH THE POTENTIAL FOR DAILY DELTA BREEZE COOLING GIVEN
THE TROUGH POSITION AND PERHAPS SOME OVERNIGHT LOW CLOUDS
EXTENDING INTO THE DELTA REGION. DRY WEATHER IS EXPECTED THROUGH
THE PERIOD AS THE MONSOONAL FLOW REMAINS WELL EASTWARD OF OUR AREA.
&&
.AVIATION...
VFR CONDS WILL CONTINUE NEXT 24 HOURS. ONSHORE FLOW PERSISTS
WITH STRONGEST WINDS IN THE DELTA REGION AT 15-25 KTS FROM THE
WEST. VALLEY WINDS WILL START OFF LIGHT THIS MORNING...THEN
STRENGTHEN LATER THIS AFTN/EVENING TO SW 10-15 KTS. WINDS ALOFT
WILL GENERALLY BE LIGHT FROM THE SW TODAY AND WEDNESDAY. -DVC
&&
.STO WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...CORRECTED
NWS CHARLESTON SC
546 PM EDT TUE JUL 24 2012
...SLIGHT RISK OF SEVERE THUNDERSTORMS...
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL REMAIN SOUTH OF THE AREA THROUGH THE
WEEK AS A TROUGH OF LOW PRESSURE PERSISTS INLAND. A WEAK COLD FRONT
MAY APPROACH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
A WEAK SURFACE TROUGH EXTENDS FROM SOUTHWEST GEORGIA THROUGH THE
EASTERN MIDLANDS INTO COASTAL NORTH CAROLINA. SCATTERED SHOWERS
AND TSTMS HAVE RECENTLY POPPED IN THE VICINITY OF THIS FEATURE
WITH THE LARGEST CONCENTRATION OCCURRING NEAR VIDALIA. WHILE THIS
ACTIVITY MAY LINGER FOR ANOTHER FEW HOURS WITHIN AN AXIS OF MODEST
INSTABILITY...WEAK SHEAR AND THE LACK OF AN UPPER LEVEL FORCING
MECHANISM SUGGESTS MOST OF THIS SHOULD DISSIPATE NEAR OR JUST
AFTER SUNSET.
FARTHER UPSTREAM...OUTFLOW GENERATED BY A LARGE MESOSCALE
CONVECTIVE SYSTEM /MCS/ MOVING THROUGH EASTERN NORTH CAROLINA WAS
MOVING SOUTH INTO THE SOUTH CAROLINA UPSTATE AND NORTHERN
MIDLANDS. SECONDARY OUTFLOW ASSOCIATED WITH CONVECTION MOVING
THROUGH THE NORTH CAROLINA MOUNTAINS WAS ALSO MOVING QUICKLY
SOUTH. BOTH ARE EXPECTED TO MERGE AND POTENTIALLY REFIRE A
SECONDARY AREA OF CONVECTION LATER THIS EVENING ACROSS CENTRAL AND
NORTHERN SOUTH CAROLINA AS SHORTWAVE ENERGY EMBEDDED IN THE
NORTHWEST FLOW ALOFT MOVES ACROSS NORTH CAROLINA. WHILE IT REMAINS
TO BE SEEN HOW THIS POTENTIAL SECONDARY MCS WILL EVOLVE...SEVERAL
HIGHER RESOLUTION MESOSCALE MODELS SUGGEST SCATTERED SHOWERS/TSTMS
WILL IMPACT PARTS OF SOUTHERN SOUTH CAROLINA. WITH MODEST
INSTABILITY IN PLACE AND RAP SHEAR PROFILES SHOWING 0-6KM BULK
SHEAR INCREASE TO NEAR 30 KT ACROSS THE MIDLANDS AFTER
SUNSET...SUSPECT THERE IS A REASONABLE CHANCE THAT SOME SORT OF
MCS COULD MAKE IT INTO PARTS OF THE LOCAL FORECAST AREA LATER THIS
EVENING...ESPECIALLY SHOULD A COLD POOL DEVELOP WITH UPSTREAM
CONVECTION.
WILL CONTINUE WITH A 20-50 POP REGIME FOR THE EVENING HOURS WITH
THE HIGHEST POPS CLUSTERED OVER THE CHARLESTON TRI-COUNTY AREA.
WILL ALSO KEEP A MENTION OF LARGE HAIL AND DAMAGING WINDS IN THE
VARIOUS GRIDDED PRODUCTS...MAINLY FROM COLLETON COUNTY NORTH INTO
THE CHARLESTON AND MONCKS CORNER AREAS. POPS WILL DROP OFF TO
SLIGHT CHANCE AFTER MIDNIGHT FOR ALL AREAS. FURTHER REFINEMENTS
WILL BE NEEDED AS THE EVENING PROGRESSES AND SHORT TERM MESOSCALE
TRENDS BECOME MORE APPARENT.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
THE 500 MB RIDGE AXIS IS PROGGED TO SHIFT OVER THE AREA ON WEDNESDAY
AND OFF THE EASTERN SEABOARD THURSDAY AND FRIDAY...ALLOWING THE
INLAND TROUGH TO STRENGTHEN. LOW-LEVELS WILL REMAIN VERY MOIST
THROUGH THE PERIOD WITH DEWPOINTS REMAINING IN THE MIDDLE 70S. THE
SEABREEZE LOOKS TO REMAIN PINNED NEAR THE COAST UNTIL LATER IN THE
AFTERNOONS DUE TO A DEEP WEST SOUTHWEST FLOW. HIGH TEMPS WILL REMAIN
ABOVE NORMAL WITH HIGHS IN THE MID AND UPPER 90S EACH DAY.
CONVECTION WILL LIKELY TAKE UNTIL EARLY AFTERNOON TO BEGIN POPPING
DUE TO A STRONG CAP IN PLACE. HEAT ADVISORY CONDITIONS MAY BE
REACHED IN SOME PLACES THURSDAY OR FRIDAY DUE TO VALUES REACHING
110F FOR 2-3 HOURS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE GREAT LAKES SHORT WAVE MOVES INTO THE NE SATURDAY...WHICH
AMPLIFIES THE TROUGH IN THE EAST. THE APEX OF THIS TROUGH STRETCHES
SOUTH TO GA/FL...AND IT MOVES LITTLE THROUGH SUNDAY. BEYOND THAT FOR
EARLY NEXT WEEK WE/RE NOT YET CERTAIN AS TO WHETHER OR NOT
ADDITIONAL SHORT WAVES DROP INTO THE TROUGH TO MAINTAIN ITS PLACE
OVER THE EAST AND SE...OR DOES IT REMAIN VOID OF ANY PERTURBATIONS
AND INSTEAD BEGINS TO LIFT OUT. AT THE SURFACE OUR CONFIDENCE IS
GOOD THAT THE INLAND TROUGH WILL REMAIN NOT FAR FROM THE LOCAL AREA
THROUGH THE WEEKEND. BUT THEN THE QUESTION REMAINS IS TO WHETHER OR
NOT A COLD FRONT IS ABLE TO REACH THE FORECAST AREA EARLY NEXT WEEK.
CLIMATOLOGY WOULD SUGGEST THE FRONT NEVER GETS THIS FAR SE...SO THIS
REMAINS TO BE SEEN. RAIN CHANCES WILL BE IN THE ISOLATED TO
SCATTERED RANGE OVER THE WEEKEND...THEN WE PREFER NOTHING MORE THAN
ISOLATED COVERAGE MONDAY AND TUESDAY SINCE OUR CONFIDENCE LOWERS.
TEMPS WILL REMAIN ABOVE SEASONAL LEVELS SATURDAY AND
SUNDAY...TRENDING BACK CLOSER TO NORMAL MONDAY AND TUESDAY.
&&
.AVIATION /22Z TUESDAY THROUGH SUNDAY/...
WE HAVE MAINTAINED PREVAILING VFR CONDITIONS THROUGH 18Z
WEDNESDAY. HOWEVER...THERE ARE INDICATIONS THAT AN MCS COULD
IMPACT THE AREA EARLY TONIGHT. PROSPECTS FOR THIS TO OCCUR ARE
GREATER AT KCHS THAN AT KSAV BUT ARE STILL PRETTY LOW SO WILL
MAINTAIN PROB30 ...THUS OUR INCLUSION OF A PROB30 FOR TSRA AT
KCHS FROM 01-05Z. IF ORGANIZED TSRA DOES DEVELOP...THEN STRONG
WINDS ARE POSSIBLE...WITH PERIODIC MVFR OR LOWER CONDITIONS TO
OCCUR.
EXTENDED AVIATION OUTLOOK...DIURNAL SHOWERS AND THUNDERSTORMS
POSSIBLE THROUGH THE WEEK.
&&
.MARINE...
TONIGHT...THE LOCAL WATERS WILL CONTINUE TO BE POSITIONED IN AN
AREA BETWEEN THE INLAND TROUGH OF LOW PRESSURE AND SUBTROPICAL HIGH
OVER THE ATLANTIC. THIS WILL MAINTAIN THE RELATIVELY TIGHT
PRESSURE GRADIENT AND KEEP THE LOW-LEVEL SW FLOW ELEVATED. WINDS
WILL MAINLY REMAIN BELOW 20 KT...HIGHEST ACROSS THE SC WATERS. SEAS
WILL RUN 2-4 FT WITHIN 20 NM...AND 4-5 FT BEYOND. THUNDERSTORMS
MAY MOVE INTO PORTIONS OF THE WATERS THIS EVENING...ESPECIALLY
THE SC WATERS...SOME OF WHICH WILL BE STRONG OR EVEN SEVERE WITH
DAMAGING WINDS AND FREQUENT LIGHTNING THE MAIN HAZARDS.
WEDNESDAY THROUGH SUNDAY...THE GRADIENT WILL RELAX A BIT ON
WEDNESDAY BUT TIGHTEN AGAIN THURSDAY INTO FRIDAY AS ATLANTIC HIGH
PRESSURE STRENGTHENS TO OUR EAST AND THE INLAND TROUGH DEEPENS.
CONDITIONS LOOK TO REMAIN BELOW SMALL CRAFT CRITERIA BUT WE COULD
SEE SOME SOLID 15-20 KTS DURING OVERNIGHT SURGES AND THE COASTAL
SEABREEZE COULD EXCEED 15 KT AT TIMES DURING THE AFTERNOONS. SEAS
WILL BE A MIXTURE OF SHORT PERIOD WIND DRIVEN WAVES AND LONGER
PERIOD SWELL WAVES...WITH THE RESULTING COMBINED SEAS MOSTLY HELD
AT OR BELOW 4 OR 5 FT.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...JRL
LONG TERM...
AVIATION...RJB
MARINE...
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
324 PM CDT TUE JUL 24 2012
.SYNOPSIS...
ISSUED AT 112 AM CDT TUE JUL 24 2012
A FAIRLY IMPRESSIVE UPPER LOW BY MID-SUMMER STANDARDS WAS CENTERED
OVER SOUTHERN ALBERTA AS OF 24.05Z WITH A COMPACT 70-80 KNOT JET
STREAK ON THE SOUTHEAST SIDE OF THE LOW AT 400MB (PER RAP ANALYSIS).
THERE WAS ANOTHER DEPARTING MID-UPPER LEVEL TROUGH ACROSS
SOUTHEASTERN CANADA TO THE NORTHERN GREAT LAKES REGION. IN THE
LOWER TROPOSPHERE...A FRONT WAS EVIDENT IN THE 850MB ANALYSIS
EXTENDING FROM LOWER MICHIGAN TO SOUTHERN MINNESOTA. THE FRONT
CONTINUED WEST TOWARD JUST SOUTH OF THE BLACK HILLS REGION WHICH
COULD BE FOLLOWED BACK NORTHWEST INTO CENTRAL/EASTERN MONTANA.
FAIRLY STRONG COLD FRONTOGENESIS WAS BECOMING INCREASINGLY EVIDENT
ACROSS WESTERN MONTANA WITH 850MB TEMPERATURES BEHIND THE COLD FRONT
IN WASHINGTON STATE FROM +6 TO +11C. THE HOTTEST TEMPERATURES AT
850MB WERE FOUND ALONG A LINE FROM ROUGHLY THE NEBRASKA PANHANDLE TO
SOUTHEASTERN SOUTH DAKOTA WHERE TEMPS RANGED FROM +30 TO +33C ALONG
THIS AXIS. WITHIN THIS HEAT AXIS...VALENTINE NEBRASKA REACHED A HIGH
TEMPERATURE OF 109F.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 406 AM CDT TUE JUL 24 2012
AS THE STRONG, COMPACT UPPER LOW MOVES EAST ACROSS THE CANADIAN
PRAIRIES TODAY...THE COLD FRONT TIED TO THIS UPPER FEATURE WILL MOVE
SOUTH DOWN THE NORTHERN HIGH PLAINS TODAY AND TONIGHT. AS THIS IS
HAPPENING...THE LEE TROUGH OVER EASTERN COLORADO WILL FURTHER
DEEPEN AS WELL RESULTING IN INCREASED PRESSURE GRADIENT AND STRONGER
SURFACE WINDS. 18 TO 22 KT SURFACE WINDS ARE FORECAST ACROSS
SOUTHWEST KANSAS FROM THE SOUTH-SOUTHWEST. HIGHS WILL BE SIMILAR TO
THAT OF THE PAST FEW DAYS...WITH WARMEST TEMPERATURES FARTHER NORTH
WHERE THE LOW LEVEL THERMAL NOSE WILL ADVANCE FARTHER EAST IN
NORTHWEST KANSAS SUPPORTING 105 TO 107 DEGREE LATE AFTERNOON
TEMPERATURES. ELSEWHERE SOUTH OF A SCOTT CITY TO HAYS LINE HIGHS
WILL RANGE FROM 100 TO 103F. TONIGHT...THE PRESSURE GRADIENT WILL
STILL BE STRONG ENOUGH TO KEEP WINDS UP IN THE 10-15 KNOT RANGE
THROUGH THE NIGHT.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 320 PM CDT TUE JUL 24 2012
AN UPPER LEVEL SHORTWAVE TROUGH AND ASSOCIATED COOL FRONT WILL BE
MOVING ACROSS THE NORTHERN AND CENTRAL PLAINS ON WEDNESDAY NIGHT.
WITH GOOD SURFACE MOISTURE CONVERGENCE, CAPES AROUND 2000 J/KG, AND
LAYER PRECIPITABLE WATER RUNNING AROUND 125 PERCENT OF NORMAL WILL
MAINTAIN 30 TO 40 POPS ON WEDNESDAY NIGHT. WITH WEAK WINDS ALOFT AND
SLOW STORM MOVEMENT ANY STORMS THAT DEVELOP WILL BE CAPABLE OF BRIEF
HEAVY DOWNPOURS AND STRONG WIND GUSTS. THE GFS OPERATIONAL RUN
HOWEVER HAS LITTLE IF ANY MEASURABLE RAINFALL WHILE THE NAM LOOKS
MUCH MORE REASONABLE WITH QPF AND POP CHANCES. AFTER THE PASSAGE OF
THE UPPER LEVEL SHORTWAVE TROUGH THE UPPER RIDGE BUILDS BACK INTO
THE PLAINS INTO EARLY NEXT WEEK WITH HOT TEMPERATURES RETURNING.
OVERNIGHT LOWS ARE EXPECTED TO BE MILD FROM 68 TO 75 THROUGH THE
PERIOD. WE WILL HAVE A SMALL BREAK IN THE HEAT ON THURSDAY WITH THE
PASSAGE OF THE COOL FRONT WITH HIGHS IN THE MID 90S. HIGH TEMPS THEN
WARM TO NEAR THE CENTURY MARK ON FRIDAY, AND FROM 100 TO 105 INTO
THE WEEKEND AND INTO EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1257 PM CDT TUE JUL 24 2012
A SURFACE TROUGH WILL PERSIST IN THE LEE OF THE ROCKIES THROUGH
THE TAF PERIOD, CAUSING SOUTH WINDS AT 10 TO 20 KTS. A COLD FRONT
WILL APPROACH THE TAF SITES AFTER 18Z WEDNESDAY, RESULTING IN
THUNDERSTORM CHANCES AFTER THE TAF VALID PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 75 104 70 96 / 10 30 30 10
GCK 72 103 68 95 / 10 30 40 10
EHA 71 102 68 93 / 20 30 30 20
LBL 72 104 69 95 / 20 30 30 20
HYS 75 104 69 95 / 10 30 30 10
P28 77 103 74 98 / 10 10 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 8 PM CDT THIS EVENING FOR KSZ043-044-062-
063-074-075-084.
&&
$$
SYNOPSIS...UMSCHEID
SHORT TERM...UMSCHEID
LONG TERM...KRUSE
AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
107 PM CDT TUE JUL 24 2012
...UPDATED FOR AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 112 AM CDT TUE JUL 24 2012
A FAIRLY IMPRESSIVE UPPER LOW BY MID-SUMMER STANDARDS WAS CENTERED
OVER SOUTHERN ALBERTA AS OF 24.05Z WITH A COMPACT 70-80 KNOT JET
STREAK ON THE SOUTHEAST SIDE OF THE LOW AT 400MB (PER RAP ANALYSIS).
THERE WAS ANOTHER DEPARTING MID-UPPER LEVEL TROUGH ACROSS
SOUTHEASTERN CANADA TO THE NORTHERN GREAT LAKES REGION. IN THE
LOWER TROPOSPHERE...A FRONT WAS EVIDENT IN THE 850MB ANALYSIS
EXTENDING FROM LOWER MICHIGAN TO SOUTHERN MINNESOTA. THE FRONT
CONTINUED WEST TOWARD JUST SOUTH OF THE BLACK HILLS REGION WHICH
COULD BE FOLLOWED BACK NORTHWEST INTO CENTRAL/EASTERN MONTANA.
FAIRLY STRONG COLD FRONTOGENESIS WAS BECOMING INCREASINGLY EVIDENT
ACROSS WESTERN MONTANA WITH 850MB TEMPERATURES BEHIND THE COLD FRONT
IN WASHINGTON STATE FROM +6 TO +11C. THE HOTTEST TEMPERATURES AT
850MB WERE FOUND ALONG A LINE FROM ROUGHLY THE NEBRASKA PANHANDLE TO
SOUTHEASTERN SOUTH DAKOTA WHERE TEMPS RANGED FROM +30 TO +33C ALONG
THIS AXIS. WITHIN THIS HEAT AXIS...VALENTINE NEBRASKA REACHED A HIGH
TEMPERATURE OF 109F.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 406 AM CDT TUE JUL 24 2012
AS THE STRONG, COMPACT UPPER LOW MOVES EAST ACROSS THE CANADIAN
PRAIRIES TODAY...THE COLD FRONT TIED TO THIS UPPER FEATURE WILL MOVE
SOUTH DOWN THE NORTHERN HIGH PLAINS TODAY AND TONIGHT. AS THIS IS
HAPPENING...THE LEE TROUGH OVER EASTERN COLORADO WILL FURTHER
DEEPEN AS WELL RESULTING IN INCREASED PRESSURE GRADIENT AND STRONGER
SURFACE WINDS. 18 TO 22 KT SURFACE WINDS ARE FORECAST ACROSS
SOUTHWEST KANSAS FROM THE SOUTH-SOUTHWEST. HIGHS WILL BE SIMILAR TO
THAT OF THE PAST FEW DAYS...WITH WARMEST TEMPERATURES FARTHER NORTH
WHERE THE LOW LEVEL THERMAL NOSE WILL ADVANCE FARTHER EAST IN
NORTHWEST KANSAS SUPPORTING 105 TO 107 DEGREE LATE AFTERNOON
TEMPERATURES. ELSEWHERE SOUTH OF A SCOTT CITY TO HAYS LINE HIGHS
WILL RANGE FROM 100 TO 103F. TONIGHT...THE PRESSURE GRADIENT WILL
STILL BE STRONG ENOUGH TO KEEP WINDS UP IN THE 10-15 KNOT RANGE
THROUGH THE NIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 406 AM CDT TUE JUL 24 2012
MEDIUM RANGE MODELS INDICATE AN UPPER LEVEL SHORTWAVE TROUGH OF LOW
PRESSURE EJECTING EASTWARD OUT OF THE CENTRAL AND SOUTHERN ROCKIES
INTO THE WESTERN HIGH PLAINS WEDNESDAY BRINGING A MUCH NEEDED CHANCE
FOR PRECIP TO PORTIONS OF WESTERN KANSAS. AN ATTENDANT COLD FRONT IS
PROJECTED TO PUSH SOUTHEAST INTO WESTERN KANSAS SOMETIME BY EARLY TO
MID AFTERNOON WEDNESDAY SETTING THE STAGE FOR POSSIBLE SHOWER AND
THUNDERSTORM DEVELOPMENT. AS THE FRONT BEGINS TO PUSH INTO THE STATE,
THE NAM, GEM, GFS, AND ECMWF POINT TO A SURFACE LOW DEVELOPING ALONG
THE FRONT, GENERALLY ACROSS SOUTHWEST KANSAS. THIS WILL INCREASE LOW
LEVEL FORCING, PARTICULARLY TO THE NORTH AND EAST OF THE SURFACE LOW
ALONG THE BOUNDARY ITSELF. AMPLE MOISTURE WILL BE ON HAND AS A
PREVAILING LOW LEVEL SOUTHERLY FLOW IS EXPECTED TO DRIVE IT NORTH
WITH H85 DEWPOINTS JUST ABOVE 10C ACROSS MUCH OF CENTRAL AND WESTERN
KANSAS. ADDITIONALLY, NAM AND GFS MODEL SOUNDINGS DO POINT TO PLENTY
OF AVAILABLE MID/UPPER LEVEL INSTABILITY BY WEDNESDAY AFTERNOON WITH
CAPE VALUES IN EXCESS OF 1500 TO 2000 J/KG. HOWEVER, A COUPLE OF
FACTORS MAY LIMIT CONVECTION ACROSS WESTERN KANSAS AS THE FRONTAL
BOUNDARY BEGINS TO PUSH INTO THE AREA. FIRST WILL BE AN EXPECTED
WEAK FLOW ALOFT AS ALL MODELS KEEP THE UPPER LEVEL JET JUST OFF TO
OUR NORTH ACROSS THE NORTHERN PLAINS. CAPPING COULD ALSO PLAY A
LIMITING FACTOR AS A HOT AFTERNOON THE PREVIOUS DAY WILL HAVE HIGH
TEMPERATURES UP NEAR TO JUST ABOVE 100F.
BECAUSE OF THE WEAK FLOW ALOFT AND THE LIKELY LOCATION OF THE
DEVELOPING SURFACE LOW, WILL KEEP 30 POPS IN ACROSS MUCH OF THE AREA
WITH 40 POPS FURTHER NORTHEAST IN CENTRAL KANSAS, ALONG WHERE THE
BOUNDARY IS EXPECTED TO BE LATE WEDNESDAY. ANY DEVELOPING STORMS ARE
ALSO EXPECTED TO BE ELEVATED WITH STRONG OUTFLOW WINDS THE PRIMARY
THREAT. DRIER CONDITIONS ARE EXPECTED THROUGH THE REMAINDER OF THE
PERIOD AS UPPER LEVEL RIDGING REDEVELOPS ACROSS THE INTERMOUNTAIN
WEST BY THURSDAY AND PUSHES SLOWLY EAST INTO THE WESTERN HIGH PLAINS
THROUGH THE WEEKEND.
TEMPERATURES ARE EXPECTED TO BE ABOVE NORMAL WEDNESDAY EVEN AS THE
COLD FRONT BEGINS TO PUSH SOUTHEAST INTO WESTERN KANSAS BY MID DAY.
AHEAD OF THE COLD FRONT, THE NAM, GFS, AND ECMWF SHOW H85
TEMPERATURES RANGING FROM THE UPPER 20S(C) ACROSS CENTRAL KANSAS
TO JUST ABOVE 30C ACROSS MUCH OF SOUTHWEST KANSAS. CONSIDERING HOW
SLOW THE MODELS HAVE THE FRONT PROJECTED TO MOVE THROUGH THE AREA,
LOOK FOR HIGHS ABOVE 100F ACROSS CENTRAL AND MUCH OF SOUTHWEST
KANSAS AGAIN WEDNESDAY AFTERNOON. HOWEVER, A BRIEF REPRIEVE FROM
TRIPLE DIGIT HIGHS IS LIKELY THURSDAY IN WAKE OF THE SLOW MOVING
COLD FRONT. A NORTH TO NORTHEAST LOW LEVEL FLOW INTO WESTERN KANSAS
WILL HELP LOWER H85 TEMPERATURES BY JUST A FEW DEGREES. EVEN SO,
EXPECT HIGHS ONLY UP INTO THE 90S(F) THURSDAY AFTERNOON. A GRADUAL
WARMING TREND IS THEN EXPECTED AGAIN AS THE AFOREMENTIONED UPPER
LEVEL RIDGING DEVELOPS ACROSS THE INTERMOUNTAIN WEST BY THURSDAY AND
BEGINS TO PUSH EAST INTO THE WESTERN HIGH PLAINS THROUGH THE WEEKEND.
SHOULD SEE HIGHS CLIMBING BACK TO JUST ABOVE 100F BY THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1257 PM CDT TUE JUL 24 2012
A SURFACE TROUGH WILL PERSIST IN THE LEE OF THE ROCKIES THROUGH
THE TAF PERIOD, CAUSING SOUTH WINDS AT 10 TO 20 KTS. A COLD FRONT
WILL APPROACH THE TAF SITES AFTER 18Z WEDNESDAY, RESULTING IN
THUNDERSTORM CHANCES AFTER THE TAF VALID PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 104 75 106 69 / 10 10 30 30
GCK 105 72 105 68 / 10 10 30 20
EHA 101 71 104 66 / 20 20 30 20
LBL 102 72 106 69 / 20 20 30 20
HYS 106 75 106 69 / 0 10 30 20
P28 104 77 105 72 / 10 10 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 8 PM CDT THIS EVENING FOR KSZ043-044-062-
063-074-075-084.
&&
$$
SYNOPSIS...UMSCHEID
SHORT TERM...UMSCHEID
LONG TERM...JJOHNSON
AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS JACKSON KY
633 PM EDT TUE JUL 24 2012
.UPDATE...
ISSUED AT 633 PM EDT TUE JUL 24 2012
WITH A MUGGY AND UNSTABLE AIRMASS STILL IN PLACE ACROSS THE SOUTHWEST
ZONES...SPC HAS ISSUED A NEW SEVERE THUNDERSTORM WATCH UNTIL 11 PM.
ONLY A FEW STORMS AFFECTING THE AREA PRESENTLY...BUT WE COULD STILL
SEE SOME NEW DEVELOPMENT THIS EVENING. MEANWHILE...QUIET CONDITIONS
ACROSS A GOOD CHUNK OF EASTERN KENTUCKY WILL LIKELY STAY THAT WAY
THROUGH MUCH OF TONIGHT. THUS...POPS HAVE BEEN REMOVED OR LOWERED
ACROSS THE BOARD. ALSO...WITH TEMPERATURES ALREADY ON THE COOL SIDE
AND RECENT RAINFALL...WE MAY SEE SOME PATCHY FOG OVERNIGHT. ZONE
UPDATE IS ALREADY OUT.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 339 PM EDT TUE JUL 24 2012
IMMEDIATE SHORT TERM ISSUES REVOLVE AROUND THE ONGOING WATCH. WITH
MORE OF THE ACTIVITY SHIFTING SOUTHWARD...GOING TO CLEAR MORE
COUNTIES OUT OF EASTERN KENTUCKY OVER THE NEXT HOUR.
MEANWHILE...STILL WATCHING AN OUTFLOW BOUNDARY...FROM CENTRAL ESTILL
COUNTY...SOUTHEAST INTO SOUTHERN BREATHITT COUNTY. THIS BOUNDARY
COULD TRIGGER ADDITIONAL STORMS AS IT SINKS SOUTHWARD THIS EVENING.
THUS...THE WATCH WILL CONTINUE ACROSS OUR SOUTHWEST COUNTIES UNTIL
THIS BOUNDARY PUSHES ACROSS THIS AREA. THE HRRR CONTINUES TO SHOW NEW
DEVELOPMENT...BUT THUS FAR...HAVE NOT SEEN ANY DEVELOPMENT ALONG THIS
BOUNDARY.
AS THIS BOUNDARY AND COMPLEX OF STORMS EXITS TO THE SOUTH THIS
EVENING...THERE WILL LIKELY BE A TEMPORARY BREAK FROM THE CONVECTION.
HOWEVER...ANOTHER WEAK WAVE IS POISED TO DROP SOUTHWARD OVERNIGHT AND
COULD GENERATE MORE SHOWERS AND THUNDERSTORMS. WITH LITTLE ACTIVITY
UPSTREAM PRESENTLY...OPTING TO KEEP POPS ON THE LOWER SIDE UNTIL
BETTER CONFIDENCE CAN BE OBTAINED.
A NORTH/SOUTH BOUNDARY WILL THEN SET UP OVER FAR EASTERN KENTUCKY
THROUGH TOMORROW AFTERNOON AND EVENING. THIS WILL KEEP UNSETTLED
WEATHER IN THE FORECAST THROUGH WEDNESDAY EVENING AS DAYTIME
INSTABILITY WILL ONCE AGAIN FUEL STORM DEVELOPMENT...ESPECIALLY OVER
SOUTHEAST AND FAR EASTERN KENTUCKY. THE FURTHER WEST YOU GO AWAY FROM
THE BOUNDARY...THE MORE LIKELIHOOD TO MISS OUT ON ANY STORMS
TOMORROW. BASED ON THE WEAK STORM MOVEMENT TOMORROW AFTERNOON...WE
MAY HAVE TO WATCH FOR TRAINING STORMS AND FLASH FLOODING POTENTIAL.
PW`S WILL STILL BE CLOSE TO 2 INCHES TOMORROW...SO CLEARLY GOING TO
HAVE TO KEEP AN EYE ON THE FLOODING POTENTIAL. WE MAY NEED A FLASH
FLOOD WATCH...BUT WILL LET THE MIDNIGHT SHIFT REEVALUATE.
THIS BOUNDARY WILL EVENTUALLY DEPART TO THE NORTHEAST TOMORROW
NIGHT...TAKING THE THREAT OF PRECIPITATION WITH IT AND PUTTING THE
AREA UNDER STRONGER INFLUENCE OF THE HIGH. MILD CONDITIONS WILL
CONTINUE WITH HIGHS ON WEDNESDAY WELL INTO THE 80S...AND LOWS TONIGHT
AND WEDNESDAY NIGHT IN THE LOWER 70S.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 339 PM EDT TUE JUL 24 2012
THE MODELS ARE IN VERY GOOD AGREEMENT WITH THE GENERAL LONG WAVE
PATTERN. THURSDAY STARTS OUT WITH A UPPER LOW OVER MINNESOTA WITH A
TROUGH EXTENDING SOUTH ALONG THE I35 CORRIDOR. THE TROUGH WILL MOVE
TO THE EAST AND WILL PASS EASTERN KENTUCKY ON FRIDAY NIGHT/SATURDAY
MORNING TIME FRAME. THE TROUGH WILL FINALLY PUSH A LINGERING COLD
FRONT SOUTH AND EAST OF THE AREA ON FRIDAY. THIS WILL HELP TO BRING
SOME COOLER AND DRIER AIR INTO THE AREA. WITH THE MODELS IN SUCH
GOOD AGREEMENT...RELIED VERY HEAVILY ON THE MODEL BLEND FOR ALL
FIELDS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 130 PM EDT TUE JUL 24 2012
ALL OF EASTERN KENTUCKY IS UNDER A SEVERE THUNDERSTORM WATCH UNTIL
23Z. AS SUCH...THE THUNDERSTORMS OVER THE AREA ARE VERY DANGEROUS
AND THE POTENTIAL FOR LLWS IS GREATER THAN NORMAL. ONCE THE
THUNDERSTORMS MOVE THROUGH THE AREA...THEN FOG WILL BE A THREAT
TONIGHT...ESPECIALLY IN VALLEY LOCATIONS. HAVE PUT FOG IN FOR THE TAF
STATIONS...HOWEVER IF PRECIPITATION IS NOT VERY WIDESPREAD...THEN THE
FOG IS NOT AS LIKELY AT SME AND LOZ. SOMETIMES AFTER A RAIN...THERE
IS A TEMPO FOG CONDITION THAT IS NOT VERY LONG LIVED...HOWEVER TRYING
TO TIME IT IS ALMOST IMPOSSIBLE THIS FAR OUT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...KAS
LONG TERM....JJ
AVIATION...JJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
340 PM EDT TUE JUL 24 2012
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 339 PM EDT TUE JUL 24 2012
IMMEDIATE SHORT TERM ISSUES REVOLVE AROUND THE ONGOING WATCH. WITH
MORE OF THE ACTIVITY SHIFTING SOUTHWARD...GOING TO CLEAR MORE
COUNTIES OUT OF EASTERN KENTUCKY OVER THE NEXT HOUR.
MEANWHILE...STILL WATCHING AN OUTFLOW BOUNDARY...FROM CENTRAL ESTILL
COUNTY...SOUTHEAST INTO SOUTHERN BREATHITT COUNTY. THIS BOUNDARY
COULD TRIGGER ADDITIONAL STORMS AS IT SINKS SOUTHWARD THIS EVENING.
THUS...THE WATCH WILL CONTINUE ACROSS OUR SOUTHWEST COUNTIES UNTIL
THIS BOUNDARY PUSHES ACROSS THIS AREA. THE HRRR CONTINUES TO SHOW NEW
DEVELOPMENT...BUT THUS FAR...HAVE NOT SEEN ANY DEVELOPMENT ALONG THIS
BOUNDARY.
AS THIS BOUNDARY AND COMPLEX OF STORMS EXITS TO THE SOUTH THIS
EVENING...THERE WILL LIKELY BE A TEMPORARY BREAK FROM THE CONVECTION.
HOWEVER...ANOTHER WEAK WAVE IS POISED TO DROP SOUTHWARD OVERNIGHT AND
COULD GENERATE MORE SHOWERS AND THUNDERSTORMS. WITH LITTLE ACTIVITY
UPSTREAM PRESENTLY...OPTING TO KEEP POPS ON THE LOWER SIDE UNTIL
BETTER CONFIDENCE CAN BE OBTAINED.
A NORTH/SOUTH BOUNDARY WILL THEN SET UP OVER FAR EASTERN KENTUCKY
THROUGH TOMORROW AFTERNOON AND EVENING. THIS WILL KEEP UNSETTLED
WEATHER IN THE FORECAST THROUGH WEDNESDAY EVENING AS DAYTIME
INSTABILITY WILL ONCE AGAIN FUEL STORM DEVELOPMENT...ESPECIALLY OVER
SOUTHEAST AND FAR EASTERN KENTUCKY. THE FURTHER WEST YOU GO AWAY FROM
THE BOUNDARY...THE MORE LIKELIHOOD TO MISS OUT ON ANY STORMS
TOMORROW. BASED ON THE WEAK STORM MOVEMENT TOMORROW AFTERNOON...WE
MAY HAVE TO WATCH FOR TRAINING STORMS AND FLASH FLOODING POTENTIAL.
PW`S WILL STILL BE CLOSE TO 2 INCHES TOMORROW...SO CLEARLY GOING TO
HAVE TO KEEP AN EYE ON THE FLOODING POTENTIAL. WE MAY NEED A FLASH
FLOOD WATCH...BUT WILL LET THE MIDNIGHT SHIFT REEVALUATE.
THIS BOUNDARY WILL EVENTUALLY DEPART TO THE NORTHEAST TOMORROW
NIGHT...TAKING THE THREAT OF PRECIPITATION WITH IT AND PUTTING THE
AREA UNDER STRONGER INFLUENCE OF THE HIGH. MILD CONDITIONS WILL
CONTINUE WITH HIGHS ON WEDNESDAY WELL INTO THE 80S...AND LOWS TONIGHT
AND WEDNESDAY NIGHT IN THE LOWER 70S.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 339 PM EDT TUE JUL 24 2012
THE MODELS ARE IN VERY GOOD AGREEMENT WITH THE GENERAL LONG WAVE
PATTERN. THURSDAY STARTS OUT WITH A UPPER LOW OVER MINNESOTA WITH A
TROUGH EXTENDING SOUTH ALONG THE I35 CORRIDOR. THE TROUGH WILL MOVE
TO THE EAST AND WILL PASS EASTERN KENTUCKY ON FRIDAY NIGHT/SATURDAY
MORNING TIME FRAME. THE TROUGH WILL FINALLY PUSH A LINGERING COLD
FRONT SOUTH AND EAST OF THE AREA ON FRIDAY. THIS WILL HELP TO BRING
SOME COOLER AND DRIER AIR INTO THE AREA. WITH THE MODELS IN SUCH
GOOD AGREEMENT...RELIED VERY HEAVILY ON THE MODEL BLEND FOR ALL
FIELDS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 130 PM EDT TUE JUL 24 2012
ALL OF EASTERN KENTUCKY IS UNDER A SEVERE THUNDERSTORM WATCH UNTIL
23Z. AS SUCH...THE THUNDERSTORMS OVER THE AREA ARE VERY DANGEROUS
AND THE POTENTIAL FOR LLWS IS GREATER THAN NORMAL. ONCE THE
THUNDERSTORMS MOVE THROUGH THE AREA...THEN FOG WILL BE A THREAT
TONIGHT...ESPECIALLY IN VALLEY LOCATIONS. HAVE PUT FOG IN FOR THE TAF
STATIONS...HOWEVER IF PRECIPITATION IS NOT VERY WIDESPREAD...THEN THE
FOG IS NOT AS LIKELY AT SME AND LOZ. SOMETIMES AFTER A RAIN...THERE
IS A TEMPO FOG CONDITION THAT IS NOT VERY LONG LIVED...HOWEVER TRYING
TO TIME IT IS ALMOST IMPOSSIBLE THIS FAR OUT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KAS
LONG TERM....JJ
AVIATION...JJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
259 PM EDT TUE JUL 24 2012
.UPDATE...
ISSUED AT 258 PM EDT TUE JUL 24 2012
CLEARED COUNTIES NORTH OF I-64 OUT OF THE WATCH WITH THE COMPLEX OF
STORMS PUSHING OFF TO THE SOUTH. MAIN THREAT FOR SHOWERS AND STORMS
IN THE IMMEDIATE FUTURE IS BASICALLY EAST AND SOUTH OF JACKSON.
HOWEVER...STILL SOME BOUNDARIES PUSHING INTO AREAS FURTHER WEST...SO
CANNOT RULE OUT SOME REDEVELOPMENT THROUGH THE EVENING HOURS.
UPDATE ISSUED AT 1237 PM EDT TUE JUL 24 2012
MCS CONTINUES TO PROGRESS SOUTHWARD AND A WATCH HAS BEEN ISSUED FOR
ALL OF EASTERN KENTUCKY. THE MAIN THREAT WILL BE DAMAGING WINDS AS
THIS SYSTEM PUSHES SOUTH THROUGH THE AFTERNOON HOURS. EXPECTED
ARRIVAL TIMES IS FROM AROUND 1 PM IN THE NORTH TO 5 PM IN THE SOUTH
(NEAR THE TENNESSEE BORDER). STILL RECEIVING LOTS OF REPORTS OF
DAMAGE TO THE NORTH...SO THINGS COULD GET VERY INTERESTING IN OUR
NECK OF THE WOODS THIS AFTERNOON...ESPECIALLY WITH AREAS IN OUR
SOUTHWEST ALREADY VERY UNSTABLE WITH 3000J/KG OF SBCAPE.
UPDATE ISSUED AT 1216 PM EDT TUE JUL 24 2012
MCS IN SOUTHERN OHIO HAS TAKEN MORE OF A TURN TO THE SOUTH AND NOW IS
LOOKING LIKE IT MAY TAKE AIM ON MUCH OF EASTERN KENTUCKY. THIS SYSTEM
HAS BEEN PRODUCING PRETTY WIDESPREAD WIND DAMAGE AS IT HAS TRACKED
SOUTHWARD...SO IF IT HOLDS TOGETHER SPC MAY END UP ISSUING A WATCH
FOR OUR AREA. THIS SYSTEM MAY EXPAND A BIT TO THE WEST AS IT TRACKS
SOUTH WITH PLENTY OF INSTABILITY TO TO FEED OFF OF JUST TO THE WEST.
UPDATE ISSUED AT 1057 AM EDT TUE JUL 24 2012
COMPLEX OF SHOWERS AND STORMS CURRENTLY DROPPING SOUTHEAST ACROSS
EASTERN KENTUCKY. VERY COMPLEX PATTERN SETTING UP FOR THIS AFTERNOON.
IT LOOKS LIKE A DIFFERENTIAL TEMPERATURE BOUNDARY MAY BECOME
ESTABLISHED AFTER THIS MORNINGS ACTIVITY EXITS...CREATING A FOCUS FOR
NEW DEVELOPMENT BASICALLY ALONG AND SOUTHWEST OF A LINE FROM MOUNT
STERLING...THROUGH JACKSON...TO HARLAN. THUS...BELIEVE THE TARGETED
AREA WILL BE OUR MORE SOUTHWESTERN ZONES...CONTRARY TO THE PREVIOUS
FORECAST. THE HRRR SUPPORTS THIS IDEA WITH MOST OF THE ACTIVITY THIS
AFTERNOON AND EVENING IN OUR SOUTHWEST. THIS IS ALSO SUPPORTED BY AN
OUTFLOW BOUNDARY GENERATED FROM AN MCS CURRENTLY PUSHING INTO
SOUTHWEST OHIO. THIS WILL LIKELY PUSH THIS OUTFLOW BOUNDARY INTO
EASTERN KENTUCKY AS THIS SYSTEM TRACKS SOUTH AND EAST INTO WEST
VIRGINIA BY MIDDAY. THE AREA SEEING THE SHOWER AND STORM ACTIVITY
PRESENTLY WILL HAVE A TOUGH TIME REGENERATING ANY INSTABILITY...BUT
AREAS UNTAPPED TO THE SOUTHWEST WILL BE A DIFFERENT STORY. THUS...THE
SEVERE THREAT STILL SEEMS REASONABLE...BUT MAINLY FOR THE SOUTHWEST
ZONES. DAMAGING WINDS WILL BE THE PRIMARY THREAT. IT APPEARS THE MAIN
THREAT FOR SEVERE WEATHER WILL START AFTER 3 PM UNTIL 9 OR 10 PM.
UPDATE ISSUED AT 804 AM EDT TUE JUL 24 2012
UPDATED TO ALLOW FOR EARLIER ARRIVAL OF PRECIP POTENTIAL TODAY...WITH
SCATTERED SHOWERS AND STORMS ALREADY PRESENTLY DEVELOPING AND
ENTERING THE FORECAST AREA FROM THE NW.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 352 AM EDT TUE JUL 24 2012
THUNDERSTORMS WERE EXPLODING UPSTREAM OVER NORTH CENTRAL INDIANA AT
3 AM...WITH MORE OF THEM FURTHER NORTHWEST OVER THE UPPER MISSISSIPPI
VALLEY. THIS ACTIVITY INITIATED NEAR A FRONTAL BOUNDARY UNDER THE
PERIPHERY OF AN UPPER RIDGE. MODELS SHOW CONVECTION RUNNING AROUND
THE PERIPHERY OF THE RIDGE AND DEVELOPING/PROPAGATING INTO THE LOCAL
AREA DURING THE DAY. FORECAST SOUNDINGS SHOW AMPLE INSTABILITY
BUILDING DURING THE DAY...WITH CAPE LIKELY REACHING 2500-3000 J/KG.
ALTHOUGH SHEAR WILL NOT BE PHENOMENAL...IT SHOULD AT LEAST ALLOW FOR
ORGANIZATION...WITH A LIMITED AMOUNT OF BOTH SPEED AND DIRECTIONAL
SHEAR. IT WILL BE THROUGH A DEEP LAYER AND NOT CONCENTRATED IN THE
LOW LEVELS. ALSO FREEZING LEVELS WILL BE HIGH...IN THE NEIGHBORHOOD
OF 14-14.5K FEET. THUS...THE MAIN SEVERE THREAT LOOKS TO BE
WIND...BUT WITH STRONG INSTABILITY AND SOME POTENTIAL FOR STORM
ROTATION...HAIL ALSO NEEDS TO BE CONSIDERED.
THE SURFACE COLD FRONT IS EXPECTED TO SAG INTO KY TONIGHT...AND WOULD
NOT RULE OUT ADDITIONAL CONVECTION DEVELOPING. HOWEVER...IF
INSTABILITY IS SPENT ON EARLIER CONVECTION...CONFIDENCE IN COVERAGE
IS NOT AS HIGH DURING THE NIGHT.
ON WEDNESDAY...THE FRONT RETREATS TO THE NORTHEAST AND UPPER RIDGING
ALSO SHIFTS EASTWARD OVER THE AREA...WITH WINDS ALOFT WEAKENING. LOW
LEVEL MOISTURE SHOULD ALSO BE SLIGHTLY LESS...WHILE MID LEVEL TEMPS
WARM SLIGHTLY. ALL COMBINED...CONDITIONS WILL NOT BE AS FAVORABLE FOR
WIDESPREAD CONVECTION...AND HAVE USED LOWER POPS ONLY IN THE SLIGHT
CHANCE RANGE ON WEDNESDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 400 AM EDT TUE JUL 24 2012
THE 24.00Z MODEL SUITE REMAINS IN FAIRLY GOOD AGREEMENT WITH THE
EVOLUTION OF THE UPPER LEVEL PATTERN THROUGH THE MAJORITY OF THE
PERIOD BUT DOES SHOW MINOR DIFFERENCES WITH HOW THINGS END UP TOWARDS
THE BEGINNING OF NEXT WEEK. AS SUCH...HAVE GENERALLY RELIED ON A
BLENDED CONSENSUS WITH A LITTLE MORE WEIGHT TO A SLIGHTLY MORE
REASONABLE 24.00Z ECMWF FOR SPECIFICS. WILL KICK OFF WITH ANY
LINGERING ACTIVITY FROM WEDNESDAY DWINDLING WITH THE USUAL LOSS OF
DAYTIME HEATING INFLUENCES AS ANOTHER LOW PRESSURE SYSTEM CURRENTLY
OVER THE CANADIAN ROCKIES BEGINS CARVING INTO THE NRN PLAINS AND
UPPER MIDWEST. THE SFC REFLECTION IS EXPECTED TO BEGIN TRAVERSING THE
GREAT LAKES WEDNESDAY NIGHT INTO THURSDAY WITH THE ASSOCIATED RAINS
ALONG THE COLD FRONT STILL OVER THE MIDWEST AND UPPER MS VALLEY.
CURRENT CONSENSUS BRINGS THE FORCING ASSOCIATED WITH THE FRONT INTO
THE LOCAL PICTURE LATE THURSDAY/THURSDAY NIGHT AND CONTINUING
THROUGH THE DAY ON FRIDAY AS FAVORABLE RIGHT ENTRANCE DYNAMICS OF AN
UPPER LEVEL JET GRACES THE OHIO VALLEY. HAVE TRENDED THE FORECAST
DRIER FOR MUCH OF THE AREA THROUGH MOST OF THURSDAY WITH POPS
PEAKING THURSDAY NIGHT AND FRIDAY. MODELS ARE FAIRLY PROGRESSIVE
WITH THE PARENT UPPER LEVEL TROF...PUSHING IT THROUGH THE COAL
FIELDS ON SATURDAY AS HEIGHTS BEGIN SLOWLY REBOUNDING OVER ERN KY IN
RESPONSE TO SFC HIGH PRESSURE BUILDING DOWN FROM THE GREAT LAKES
WHILE THE PERSISTENT UPPER LEVEL PLAINS RIDGE BEGINS REBUILDING AND
EXPANDING ACROSS THE MS VALLEY. THIS SHOULD PROVIDE FOR A RELATIVELY
QUIET...IF NOT DRY SPELL OVER MOST OF THE UPCOMING WEEKEND.
AS FOR TEMPERATURES...GIVEN THE RELATIVELY GOOD AGREEMENT AMONG THE
GUIDANCE SAW NO REASON TO DEVIATE TOO FAR FROM THE LATEST OFFERINGS
WHICH WERE STILL IN LINE WITH THE INHERITED NUMBERS. THIS RESULTED
IN TEMPS GENERALLY RUNNING ABOVE NORMAL EARLY IN THE PERIOD...WITH
HEAT INDICES ON THURSDAY QUITE POSSIBLY RETURNING TO THE TRIPLE
DIGITS AHEAD OF THE FRONT...BEFORE TURNING TOWARDS CLIMO ON FRIDAY
WITH HIGHS IN THE MID TO UPPER 80S AND OVERNIGHT LOWS GENERALLY IN
THE UPPER 60S THROUGH THE REMAINDER OF THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 130 PM EDT TUE JUL 24 2012
ALL OF EASTERN KENTUCKY IS UNDER A SEVERE THUNDERSTORM WATCH UNTIL
23Z. AS SUCH...THE THUNDERSTORMS OVER THE AREA ARE VERY DANGEROUS
AND THE POTENTIAL FOR LLWS IS GREATER THAN NORMAL. ONCE THE
THUNDERSTORMS MOVE THROUGH THE AREA...THEN FOG WILL BE A THREAT
TONIGHT...ESPECIALLY IN VALLEY LOCATIONS. HAVE PUT FOG IN FOR THE TAF
STATIONS...HOWEVER IF PRECIPITATION IS NOT VERY WIDESPREAD...THEN THE
FOG IS NOT AS LIKELY AT SME AND LOZ. SOMETIMES AFTER A RAIN...THERE
IS A TEMPO FOG CONDITION THAT IS NOT VERY LONG LIVED...HOWEVER TRYING
TO TIME IT IS ALMOST IMPOSSIBLE THIS FAR OUT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...HAL
LONG TERM....MB
AVIATION...JJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
130 PM EDT TUE JUL 24 2012
.UPDATE...
ISSUED AT 1237 PM EDT TUE JUL 24 2012
MCS CONTINUES TO PROGRESS SOUTHWARD AND A WATCH HAS BEEN ISSUED FOR
ALL OF EASTERN KENTUCKY. THE MAIN THREAT WILL BE DAMAGING WINDS AS
THIS SYSTEM PUSHES SOUTH THROUGH THE AFTERNOON HOURS. EXPECTED
ARRIVAL TIMES IS FROM AROUND 1 PM IN THE NORTH TO 5 PM IN THE SOUTH
(NEAR THE TENNESSEE BORDER). STILL RECEIVING LOTS OF REPORTS OF
DAMAGE TO THE NORTH...SO THINGS COULD GET VERY INTERESTING IN OUR
NECK OF THE WOODS THIS AFTERNOON...ESPECIALLY WITH AREAS IN OUR
SOUTHWEST ALREADY VERY UNSTABLE WITH 3000J/KG OF SBCAPE.
UPDATE ISSUED AT 1216 PM EDT TUE JUL 24 2012
MCS IN SOUTHERN OHIO HAS TAKEN MORE OF A TURN TO THE SOUTH AND NOW IS
LOOKING LIKE IT MAY TAKE AIM ON MUCH OF EASTERN KENTUCKY. THIS SYSTEM
HAS BEEN PRODUCING PRETTY WIDESPREAD WIND DAMAGE AS IT HAS TRACKED
SOUTHWARD...SO IF IT HOLDS TOGETHER SPC MAY END UP ISSUING A WATCH
FOR OUR AREA. THIS SYSTEM MAY EXPAND A BIT TO THE WEST AS IT TRACKS
SOUTH WITH PLENTY OF INSTABILITY TO TO FEED OFF OF JUST TO THE WEST.
UPDATE ISSUED AT 1057 AM EDT TUE JUL 24 2012
COMPLEX OF SHOWERS AND STORMS CURRENTLY DROPPING SOUTHEAST ACROSS
EASTERN KENTUCKY. VERY COMPLEX PATTERN SETTING UP FOR THIS AFTERNOON.
IT LOOKS LIKE A DIFFERENTIAL TEMPERATURE BOUNDARY MAY BECOME
ESTABLISHED AFTER THIS MORNINGS ACTIVITY EXITS...CREATING A FOCUS FOR
NEW DEVELOPMENT BASICALLY ALONG AND SOUTHWEST OF A LINE FROM MOUNT
STERLING...THROUGH JACKSON...TO HARLAN. THUS...BELIEVE THE TARGETED
AREA WILL BE OUR MORE SOUTHWESTERN ZONES...CONTRARY TO THE PREVIOUS
FORECAST. THE HRRR SUPPORTS THIS IDEA WITH MOST OF THE ACTIVITY THIS
AFTERNOON AND EVENING IN OUR SOUTHWEST. THIS IS ALSO SUPPORTED BY AN
OUTFLOW BOUNDARY GENERATED FROM AN MCS CURRENTLY PUSHING INTO
SOUTHWEST OHIO. THIS WILL LIKELY PUSH THIS OUTFLOW BOUNDARY INTO
EASTERN KENTUCKY AS THIS SYSTEM TRACKS SOUTH AND EAST INTO WEST
VIRGINIA BY MIDDAY. THE AREA SEEING THE SHOWER AND STORM ACTIVITY
PRESENTLY WILL HAVE A TOUGH TIME REGENERATING ANY INSTABILITY...BUT
AREAS UNTAPPED TO THE SOUTHWEST WILL BE A DIFFERENT STORY. THUS...THE
SEVERE THREAT STILL SEEMS REASONABLE...BUT MAINLY FOR THE SOUTHWEST
ZONES. DAMAGING WINDS WILL BE THE PRIMARY THREAT. IT APPEARS THE MAIN
THREAT FOR SEVERE WEATHER WILL START AFTER 3 PM UNTIL 9 OR 10 PM.
UPDATE ISSUED AT 804 AM EDT TUE JUL 24 2012
UPDATED TO ALLOW FOR EARLIER ARRIVAL OF PRECIP POTENTIAL TODAY...WITH
SCATTERED SHOWERS AND STORMS ALREADY PRESENTLY DEVELOPING AND
ENTERING THE FORECAST AREA FROM THE NW.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 352 AM EDT TUE JUL 24 2012
THUNDERSTORMS WERE EXPLODING UPSTREAM OVER NORTH CENTRAL INDIANA AT
3 AM...WITH MORE OF THEM FURTHER NORTHWEST OVER THE UPPER MISSISSIPPI
VALLEY. THIS ACTIVITY INITIATED NEAR A FRONTAL BOUNDARY UNDER THE
PERIPHERY OF AN UPPER RIDGE. MODELS SHOW CONVECTION RUNNING AROUND
THE PERIPHERY OF THE RIDGE AND DEVELOPING/PROPAGATING INTO THE LOCAL
AREA DURING THE DAY. FORECAST SOUNDINGS SHOW AMPLE INSTABILITY
BUILDING DURING THE DAY...WITH CAPE LIKELY REACHING 2500-3000 J/KG.
ALTHOUGH SHEAR WILL NOT BE PHENOMENAL...IT SHOULD AT LEAST ALLOW FOR
ORGANIZATION...WITH A LIMITED AMOUNT OF BOTH SPEED AND DIRECTIONAL
SHEAR. IT WILL BE THROUGH A DEEP LAYER AND NOT CONCENTRATED IN THE
LOW LEVELS. ALSO FREEZING LEVELS WILL BE HIGH...IN THE NEIGHBORHOOD
OF 14-14.5K FEET. THUS...THE MAIN SEVERE THREAT LOOKS TO BE
WIND...BUT WITH STRONG INSTABILITY AND SOME POTENTIAL FOR STORM
ROTATION...HAIL ALSO NEEDS TO BE CONSIDERED.
THE SURFACE COLD FRONT IS EXPECTED TO SAG INTO KY TONIGHT...AND WOULD
NOT RULE OUT ADDITIONAL CONVECTION DEVELOPING. HOWEVER...IF
INSTABILITY IS SPENT ON EARLIER CONVECTION...CONFIDENCE IN COVERAGE
IS NOT AS HIGH DURING THE NIGHT.
ON WEDNESDAY...THE FRONT RETREATS TO THE NORTHEAST AND UPPER RIDGING
ALSO SHIFTS EASTWARD OVER THE AREA...WITH WINDS ALOFT WEAKENING. LOW
LEVEL MOISTURE SHOULD ALSO BE SLIGHTLY LESS...WHILE MID LEVEL TEMPS
WARM SLIGHTLY. ALL COMBINED...CONDITIONS WILL NOT BE AS FAVORABLE FOR
WIDESPREAD CONVECTION...AND HAVE USED LOWER POPS ONLY IN THE SLIGHT
CHANCE RANGE ON WEDNESDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 400 AM EDT TUE JUL 24 2012
THE 24.00Z MODEL SUITE REMAINS IN FAIRLY GOOD AGREEMENT WITH THE
EVOLUTION OF THE UPPER LEVEL PATTERN THROUGH THE MAJORITY OF THE
PERIOD BUT DOES SHOW MINOR DIFFERENCES WITH HOW THINGS END UP TOWARDS
THE BEGINNING OF NEXT WEEK. AS SUCH...HAVE GENERALLY RELIED ON A
BLENDED CONSENSUS WITH A LITTLE MORE WEIGHT TO A SLIGHTLY MORE
REASONABLE 24.00Z ECMWF FOR SPECIFICS. WILL KICK OFF WITH ANY
LINGERING ACTIVITY FROM WEDNESDAY DWINDLING WITH THE USUAL LOSS OF
DAYTIME HEATING INFLUENCES AS ANOTHER LOW PRESSURE SYSTEM CURRENTLY
OVER THE CANADIAN ROCKIES BEGINS CARVING INTO THE NRN PLAINS AND
UPPER MIDWEST. THE SFC REFLECTION IS EXPECTED TO BEGIN TRAVERSING THE
GREAT LAKES WEDNESDAY NIGHT INTO THURSDAY WITH THE ASSOCIATED RAINS
ALONG THE COLD FRONT STILL OVER THE MIDWEST AND UPPER MS VALLEY.
CURRENT CONSENSUS BRINGS THE FORCING ASSOCIATED WITH THE FRONT INTO
THE LOCAL PICTURE LATE THURSDAY/THURSDAY NIGHT AND CONTINUING
THROUGH THE DAY ON FRIDAY AS FAVORABLE RIGHT ENTRANCE DYNAMICS OF AN
UPPER LEVEL JET GRACES THE OHIO VALLEY. HAVE TRENDED THE FORECAST
DRIER FOR MUCH OF THE AREA THROUGH MOST OF THURSDAY WITH POPS
PEAKING THURSDAY NIGHT AND FRIDAY. MODELS ARE FAIRLY PROGRESSIVE
WITH THE PARENT UPPER LEVEL TROF...PUSHING IT THROUGH THE COAL
FIELDS ON SATURDAY AS HEIGHTS BEGIN SLOWLY REBOUNDING OVER ERN KY IN
RESPONSE TO SFC HIGH PRESSURE BUILDING DOWN FROM THE GREAT LAKES
WHILE THE PERSISTENT UPPER LEVEL PLAINS RIDGE BEGINS REBUILDING AND
EXPANDING ACROSS THE MS VALLEY. THIS SHOULD PROVIDE FOR A RELATIVELY
QUIET...IF NOT DRY SPELL OVER MOST OF THE UPCOMING WEEKEND.
AS FOR TEMPERATURES...GIVEN THE RELATIVELY GOOD AGREEMENT AMONG THE
GUIDANCE SAW NO REASON TO DEVIATE TOO FAR FROM THE LATEST OFFERINGS
WHICH WERE STILL IN LINE WITH THE INHERITED NUMBERS. THIS RESULTED
IN TEMPS GENERALLY RUNNING ABOVE NORMAL EARLY IN THE PERIOD...WITH
HEAT INDICES ON THURSDAY QUITE POSSIBLY RETURNING TO THE TRIPLE
DIGITS AHEAD OF THE FRONT...BEFORE TURNING TOWARDS CLIMO ON FRIDAY
WITH HIGHS IN THE MID TO UPPER 80S AND OVERNIGHT LOWS GENERALLY IN
THE UPPER 60S THROUGH THE REMAINDER OF THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 130 PM EDT TUE JUL 24 2012
ALL OF EASTERN KENTUCKY IS UNDER A SEVERE THUNDERSTORM WATCH UNTIL
23Z. AS SUCH...THE THUNDERSTORMS OVER THE AREA ARE VERY DANGEROUS
AND THE POTENTIAL FOR LLWS IS GREATER THAN NORMAL. ONCE THE
THUNDERSTORMS MOVE THROUGH THE AREA...THEN FOG WILL BE A THREAT
TONIGHT...ESPECIALLY IN VALLEY LOCATIONS. HAVE PUT FOG IN FOR THE TAF
STATIONS...HOWEVER IF PRECIPITATION IS NOT VERY WIDESPREAD...THEN THE
FOG IS NOT AS LIKELY AT SME AND LOZ. SOMETIMES AFTER A RAIN...THERE
IS A TEMPO FOG CONDITION THAT IS NOT VERY LONG LIVED...HOWEVER TRYING
TO TIME IT IS ALMOST IMPOSSIBLE THIS FAR OUT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...HAL
LONG TERM....MB
AVIATION...JJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
1237 PM EDT TUE JUL 24 2012
.UPDATE...
ISSUED AT 1237 PM EDT TUE JUL 24 2012
MCS CONTINUES TO PROGRESS SOUTHWARD AND A WATCH HAS BEEN ISSUED FOR
ALL OF EASTERN KENTUCKY. THE MAIN THREAT WILL BE DAMAGING WINDS AS
THIS SYSTEM PUSHES SOUTH THROUGH THE AFTERNOON HOURS. EXPECTED
ARRIVAL TIMES IS FROM AROUND 1 PM IN THE NORTH TO 5 PM IN THE SOUTH
(NEAR THE TENNESSEE BORDER). STILL RECEIVING LOTS OF REPORTS OF
DAMAGE TO THE NORTH...SO THINGS COULD GET VERY INTERESTING IN OUR
NECK OF THE WOODS THIS AFTERNOON...ESPECIALLY WITH AREAS IN OUR
SOUTHWEST ALREADY VERY UNSTABLE WITH 3000J/KG OF SBCAPE.
UPDATE ISSUED AT 1216 PM EDT TUE JUL 24 2012
MCS IN SOUTHERN OHIO HAS TAKEN MORE OF A TURN TO THE SOUTH AND NOW IS
LOOKING LIKE IT MAY TAKE AIM ON MUCH OF EASTERN KENTUCKY. THIS SYSTEM
HAS BEEN PRODUCING PRETTY WIDESPREAD WIND DAMAGE AS IT HAS TRACKED
SOUTHWARD...SO IF IT HOLDS TOGETHER SPC MAY END UP ISSUING A WATCH
FOR OUR AREA. THIS SYSTEM MAY EXPAND A BIT TO THE WEST AS IT TRACKS
SOUTH WITH PLENTY OF INSTABILITY TO TO FEED OFF OF JUST TO THE WEST.
UPDATE ISSUED AT 1057 AM EDT TUE JUL 24 2012
COMPLEX OF SHOWERS AND STORMS CURRENTLY DROPPING SOUTHEAST ACROSS
EASTERN KENTUCKY. VERY COMPLEX PATTERN SETTING UP FOR THIS AFTERNOON.
IT LOOKS LIKE A DIFFERENTIAL TEMPERATURE BOUNDARY MAY BECOME
ESTABLISHED AFTER THIS MORNINGS ACTIVITY EXITS...CREATING A FOCUS FOR
NEW DEVELOPMENT BASICALLY ALONG AND SOUTHWEST OF A LINE FROM MOUNT
STERLING...THROUGH JACKSON...TO HARLAN. THUS...BELIEVE THE TARGETED
AREA WILL BE OUR MORE SOUTHWESTERN ZONES...CONTRARY TO THE PREVIOUS
FORECAST. THE HRRR SUPPORTS THIS IDEA WITH MOST OF THE ACTIVITY THIS
AFTERNOON AND EVENING IN OUR SOUTHWEST. THIS IS ALSO SUPPORTED BY AN
OUTFLOW BOUNDARY GENERATED FROM AN MCS CURRENTLY PUSHING INTO
SOUTHWEST OHIO. THIS WILL LIKELY PUSH THIS OUTFLOW BOUNDARY INTO
EASTERN KENTUCKY AS THIS SYSTEM TRACKS SOUTH AND EAST INTO WEST
VIRGINIA BY MIDDAY. THE AREA SEEING THE SHOWER AND STORM ACTIVITY
PRESENTLY WILL HAVE A TOUGH TIME REGENERATING ANY INSTABILITY...BUT
AREAS UNTAPPED TO THE SOUTHWEST WILL BE A DIFFERENT STORY. THUS...THE
SEVERE THREAT STILL SEEMS REASONABLE...BUT MAINLY FOR THE SOUTHWEST
ZONES. DAMAGING WINDS WILL BE THE PRIMARY THREAT. IT APPEARS THE MAIN
THREAT FOR SEVERE WEATHER WILL START AFTER 3 PM UNTIL 9 OR 10 PM.
UPDATE ISSUED AT 804 AM EDT TUE JUL 24 2012
UPDATED TO ALLOW FOR EARLIER ARRIVAL OF PRECIP POTENTIAL TODAY...WITH
SCATTERED SHOWERS AND STORMS ALREADY PRESENTLY DEVELOPING AND
ENTERING THE FORECAST AREA FROM THE NW.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 352 AM EDT TUE JUL 24 2012
THUNDERSTORMS WERE EXPLODING UPSTREAM OVER NORTH CENTRAL INDIANA AT
3 AM...WITH MORE OF THEM FURTHER NORTHWEST OVER THE UPPER MISSISSIPPI
VALLEY. THIS ACTIVITY INITIATED NEAR A FRONTAL BOUNDARY UNDER THE
PERIPHERY OF AN UPPER RIDGE. MODELS SHOW CONVECTION RUNNING AROUND
THE PERIPHERY OF THE RIDGE AND DEVELOPING/PROPAGATING INTO THE LOCAL
AREA DURING THE DAY. FORECAST SOUNDINGS SHOW AMPLE INSTABILITY
BUILDING DURING THE DAY...WITH CAPE LIKELY REACHING 2500-3000 J/KG.
ALTHOUGH SHEAR WILL NOT BE PHENOMENAL...IT SHOULD AT LEAST ALLOW FOR
ORGANIZATION...WITH A LIMITED AMOUNT OF BOTH SPEED AND DIRECTIONAL
SHEAR. IT WILL BE THROUGH A DEEP LAYER AND NOT CONCENTRATED IN THE
LOW LEVELS. ALSO FREEZING LEVELS WILL BE HIGH...IN THE NEIGHBORHOOD
OF 14-14.5K FEET. THUS...THE MAIN SEVERE THREAT LOOKS TO BE
WIND...BUT WITH STRONG INSTABILITY AND SOME POTENTIAL FOR STORM
ROTATION...HAIL ALSO NEEDS TO BE CONSIDERED.
THE SURFACE COLD FRONT IS EXPECTED TO SAG INTO KY TONIGHT...AND WOULD
NOT RULE OUT ADDITIONAL CONVECTION DEVELOPING. HOWEVER...IF
INSTABILITY IS SPENT ON EARLIER CONVECTION...CONFIDENCE IN COVERAGE
IS NOT AS HIGH DURING THE NIGHT.
ON WEDNESDAY...THE FRONT RETREATS TO THE NORTHEAST AND UPPER RIDGING
ALSO SHIFTS EASTWARD OVER THE AREA...WITH WINDS ALOFT WEAKENING. LOW
LEVEL MOISTURE SHOULD ALSO BE SLIGHTLY LESS...WHILE MID LEVEL TEMPS
WARM SLIGHTLY. ALL COMBINED...CONDITIONS WILL NOT BE AS FAVORABLE FOR
WIDESPREAD CONVECTION...AND HAVE USED LOWER POPS ONLY IN THE SLIGHT
CHANCE RANGE ON WEDNESDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 400 AM EDT TUE JUL 24 2012
THE 24.00Z MODEL SUITE REMAINS IN FAIRLY GOOD AGREEMENT WITH THE
EVOLUTION OF THE UPPER LEVEL PATTERN THROUGH THE MAJORITY OF THE
PERIOD BUT DOES SHOW MINOR DIFFERENCES WITH HOW THINGS END UP TOWARDS
THE BEGINNING OF NEXT WEEK. AS SUCH...HAVE GENERALLY RELIED ON A
BLENDED CONSENSUS WITH A LITTLE MORE WEIGHT TO A SLIGHTLY MORE
REASONABLE 24.00Z ECMWF FOR SPECIFICS. WILL KICK OFF WITH ANY
LINGERING ACTIVITY FROM WEDNESDAY DWINDLING WITH THE USUAL LOSS OF
DAYTIME HEATING INFLUENCES AS ANOTHER LOW PRESSURE SYSTEM CURRENTLY
OVER THE CANADIAN ROCKIES BEGINS CARVING INTO THE NRN PLAINS AND
UPPER MIDWEST. THE SFC REFLECTION IS EXPECTED TO BEGIN TRAVERSING THE
GREAT LAKES WEDNESDAY NIGHT INTO THURSDAY WITH THE ASSOCIATED RAINS
ALONG THE COLD FRONT STILL OVER THE MIDWEST AND UPPER MS VALLEY.
CURRENT CONSENSUS BRINGS THE FORCING ASSOCIATED WITH THE FRONT INTO
THE LOCAL PICTURE LATE THURSDAY/THURSDAY NIGHT AND CONTINUING
THROUGH THE DAY ON FRIDAY AS FAVORABLE RIGHT ENTRANCE DYNAMICS OF AN
UPPER LEVEL JET GRACES THE OHIO VALLEY. HAVE TRENDED THE FORECAST
DRIER FOR MUCH OF THE AREA THROUGH MOST OF THURSDAY WITH POPS
PEAKING THURSDAY NIGHT AND FRIDAY. MODELS ARE FAIRLY PROGRESSIVE
WITH THE PARENT UPPER LEVEL TROF...PUSHING IT THROUGH THE COAL
FIELDS ON SATURDAY AS HEIGHTS BEGIN SLOWLY REBOUNDING OVER ERN KY IN
RESPONSE TO SFC HIGH PRESSURE BUILDING DOWN FROM THE GREAT LAKES
WHILE THE PERSISTENT UPPER LEVEL PLAINS RIDGE BEGINS REBUILDING AND
EXPANDING ACROSS THE MS VALLEY. THIS SHOULD PROVIDE FOR A RELATIVELY
QUIET...IF NOT DRY SPELL OVER MOST OF THE UPCOMING WEEKEND.
AS FOR TEMPERATURES...GIVEN THE RELATIVELY GOOD AGREEMENT AMONG THE
GUIDANCE SAW NO REASON TO DEVIATE TOO FAR FROM THE LATEST OFFERINGS
WHICH WERE STILL IN LINE WITH THE INHERITED NUMBERS. THIS RESULTED
IN TEMPS GENERALLY RUNNING ABOVE NORMAL EARLY IN THE PERIOD...WITH
HEAT INDICES ON THURSDAY QUITE POSSIBLY RETURNING TO THE TRIPLE
DIGITS AHEAD OF THE FRONT...BEFORE TURNING TOWARDS CLIMO ON FRIDAY
WITH HIGHS IN THE MID TO UPPER 80S AND OVERNIGHT LOWS GENERALLY IN
THE UPPER 60S THROUGH THE REMAINDER OF THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 804 AM EDT TUE JUL 24 2012
SCATTERED SHOWERS AND THUNDERSTORMS WERE ENTERING THE FORECAST AREA
FROM THE NORTHWEST AT THE START OF THE PERIOD...AND WILL CONTINUE TO
INCREASE IN COVERAGE. THEY WILL BRING LOCALIZED IFR TODAY. IF ENOUGH
DESTABILIZATION CAN OCCUR...SOME OF THE STORMS MAY BRING STRONG WINDS
AND POSSIBLY HAIL IN THE AFTERNOON. WILL EXPECT A RELATIVE LULL IN
PRECIP LATE THIS EVENING AND OVERNIGHT. HOWEVER...FOG WILL BE A
THREAT TONIGHT...ESPECIALLY IN VALLEY LOCATIONS IF CLOUDS BREAK UP.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...HAL
LONG TERM....MB
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
1216 PM EDT TUE JUL 24 2012
.UPDATE...
ISSUED AT 1216 PM EDT TUE JUL 24 2012
MCS IN SOUTHERN OHIO HAS TAKEN MORE OF A TURN TO THE SOUTH AND NOW IS
LOOKING LIKE IT MAY TAKE AIM ON MUCH OF EASTERN KENTUCKY. THIS SYSTEM
HAS BEEN PRODUCING PRETTY WIDESPREAD WIND DAMAGE AS IT HAS TRACKED
SOUTHWARD...SO IF IT HOLDS TOGETHER SPC MAY END UP ISSUING A WATCH
FOR OUR AREA. THIS SYSTEM MAY EXPAND A BIT TO THE WEST AS IT TRACKS
SOUTH WITH PLENTY OF INSTABILITY TO TO FEED OFF OF JUST TO THE WEST.
UPDATE ISSUED AT 1057 AM EDT TUE JUL 24 2012
COMPLEX OF SHOWERS AND STORMS CURRENTLY DROPPING SOUTHEAST ACROSS
EASTERN KENTUCKY. VERY COMPLEX PATTERN SETTING UP FOR THIS AFTERNOON.
IT LOOKS LIKE A DIFFERENTIAL TEMPERATURE BOUNDARY MAY BECOME
ESTABLISHED AFTER THIS MORNINGS ACTIVITY EXITS...CREATING A FOCUS FOR
NEW DEVELOPMENT BASICALLY ALONG AND SOUTHWEST OF A LINE FROM MOUNT
STERLING...THROUGH JACKSON...TO HARLAN. THUS...BELIEVE THE TARGETED
AREA WILL BE OUR MORE SOUTHWESTERN ZONES...CONTRARY TO THE PREVIOUS
FORECAST. THE HRRR SUPPORTS THIS IDEA WITH MOST OF THE ACTIVITY THIS
AFTERNOON AND EVENING IN OUR SOUTHWEST. THIS IS ALSO SUPPORTED BY AN
OUTFLOW BOUNDARY GENERATED FROM AN MCS CURRENTLY PUSHING INTO
SOUTHWEST OHIO. THIS WILL LIKELY PUSH THIS OUTFLOW BOUNDARY INTO
EASTERN KENTUCKY AS THIS SYSTEM TRACKS SOUTH AND EAST INTO WEST
VIRGINIA BY MIDDAY. THE AREA SEEING THE SHOWER AND STORM ACTIVITY
PRESENTLY WILL HAVE A TOUGH TIME REGENERATING ANY INSTABILITY...BUT
AREAS UNTAPPED TO THE SOUTHWEST WILL BE A DIFFERENT STORY. THUS...THE
SEVERE THREAT STILL SEEMS REASONABLE...BUT MAINLY FOR THE SOUTHWEST
ZONES. DAMAGING WINDS WILL BE THE PRIMARY THREAT. IT APPEARS THE MAIN
THREAT FOR SEVERE WEATHER WILL START AFTER 3 PM UNTIL 9 OR 10 PM.
UPDATE ISSUED AT 804 AM EDT TUE JUL 24 2012
UPDATED TO ALLOW FOR EARLIER ARRIVAL OF PRECIP POTENTIAL TODAY...WITH
SCATTERED SHOWERS AND STORMS ALREADY PRESENTLY DEVELOPING AND
ENTERING THE FORECAST AREA FROM THE NW.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 352 AM EDT TUE JUL 24 2012
THUNDERSTORMS WERE EXPLODING UPSTREAM OVER NORTH CENTRAL INDIANA AT
3 AM...WITH MORE OF THEM FURTHER NORTHWEST OVER THE UPPER MISSISSIPPI
VALLEY. THIS ACTIVITY INITIATED NEAR A FRONTAL BOUNDARY UNDER THE
PERIPHERY OF AN UPPER RIDGE. MODELS SHOW CONVECTION RUNNING AROUND
THE PERIPHERY OF THE RIDGE AND DEVELOPING/PROPAGATING INTO THE LOCAL
AREA DURING THE DAY. FORECAST SOUNDINGS SHOW AMPLE INSTABILITY
BUILDING DURING THE DAY...WITH CAPE LIKELY REACHING 2500-3000 J/KG.
ALTHOUGH SHEAR WILL NOT BE PHENOMENAL...IT SHOULD AT LEAST ALLOW FOR
ORGANIZATION...WITH A LIMITED AMOUNT OF BOTH SPEED AND DIRECTIONAL
SHEAR. IT WILL BE THROUGH A DEEP LAYER AND NOT CONCENTRATED IN THE
LOW LEVELS. ALSO FREEZING LEVELS WILL BE HIGH...IN THE NEIGHBORHOOD
OF 14-14.5K FEET. THUS...THE MAIN SEVERE THREAT LOOKS TO BE
WIND...BUT WITH STRONG INSTABILITY AND SOME POTENTIAL FOR STORM
ROTATION...HAIL ALSO NEEDS TO BE CONSIDERED.
THE SURFACE COLD FRONT IS EXPECTED TO SAG INTO KY TONIGHT...AND WOULD
NOT RULE OUT ADDITIONAL CONVECTION DEVELOPING. HOWEVER...IF
INSTABILITY IS SPENT ON EARLIER CONVECTION...CONFIDENCE IN COVERAGE
IS NOT AS HIGH DURING THE NIGHT.
ON WEDNESDAY...THE FRONT RETREATS TO THE NORTHEAST AND UPPER RIDGING
ALSO SHIFTS EASTWARD OVER THE AREA...WITH WINDS ALOFT WEAKENING. LOW
LEVEL MOISTURE SHOULD ALSO BE SLIGHTLY LESS...WHILE MID LEVEL TEMPS
WARM SLIGHTLY. ALL COMBINED...CONDITIONS WILL NOT BE AS FAVORABLE FOR
WIDESPREAD CONVECTION...AND HAVE USED LOWER POPS ONLY IN THE SLIGHT
CHANCE RANGE ON WEDNESDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 400 AM EDT TUE JUL 24 2012
THE 24.00Z MODEL SUITE REMAINS IN FAIRLY GOOD AGREEMENT WITH THE
EVOLUTION OF THE UPPER LEVEL PATTERN THROUGH THE MAJORITY OF THE
PERIOD BUT DOES SHOW MINOR DIFFERENCES WITH HOW THINGS END UP TOWARDS
THE BEGINNING OF NEXT WEEK. AS SUCH...HAVE GENERALLY RELIED ON A
BLENDED CONSENSUS WITH A LITTLE MORE WEIGHT TO A SLIGHTLY MORE
REASONABLE 24.00Z ECMWF FOR SPECIFICS. WILL KICK OFF WITH ANY
LINGERING ACTIVITY FROM WEDNESDAY DWINDLING WITH THE USUAL LOSS OF
DAYTIME HEATING INFLUENCES AS ANOTHER LOW PRESSURE SYSTEM CURRENTLY
OVER THE CANADIAN ROCKIES BEGINS CARVING INTO THE NRN PLAINS AND
UPPER MIDWEST. THE SFC REFLECTION IS EXPECTED TO BEGIN TRAVERSING THE
GREAT LAKES WEDNESDAY NIGHT INTO THURSDAY WITH THE ASSOCIATED RAINS
ALONG THE COLD FRONT STILL OVER THE MIDWEST AND UPPER MS VALLEY.
CURRENT CONSENSUS BRINGS THE FORCING ASSOCIATED WITH THE FRONT INTO
THE LOCAL PICTURE LATE THURSDAY/THURSDAY NIGHT AND CONTINUING
THROUGH THE DAY ON FRIDAY AS FAVORABLE RIGHT ENTRANCE DYNAMICS OF AN
UPPER LEVEL JET GRACES THE OHIO VALLEY. HAVE TRENDED THE FORECAST
DRIER FOR MUCH OF THE AREA THROUGH MOST OF THURSDAY WITH POPS
PEAKING THURSDAY NIGHT AND FRIDAY. MODELS ARE FAIRLY PROGRESSIVE
WITH THE PARENT UPPER LEVEL TROF...PUSHING IT THROUGH THE COAL
FIELDS ON SATURDAY AS HEIGHTS BEGIN SLOWLY REBOUNDING OVER ERN KY IN
RESPONSE TO SFC HIGH PRESSURE BUILDING DOWN FROM THE GREAT LAKES
WHILE THE PERSISTENT UPPER LEVEL PLAINS RIDGE BEGINS REBUILDING AND
EXPANDING ACROSS THE MS VALLEY. THIS SHOULD PROVIDE FOR A RELATIVELY
QUIET...IF NOT DRY SPELL OVER MOST OF THE UPCOMING WEEKEND.
AS FOR TEMPERATURES...GIVEN THE RELATIVELY GOOD AGREEMENT AMONG THE
GUIDANCE SAW NO REASON TO DEVIATE TOO FAR FROM THE LATEST OFFERINGS
WHICH WERE STILL IN LINE WITH THE INHERITED NUMBERS. THIS RESULTED
IN TEMPS GENERALLY RUNNING ABOVE NORMAL EARLY IN THE PERIOD...WITH
HEAT INDICES ON THURSDAY QUITE POSSIBLY RETURNING TO THE TRIPLE
DIGITS AHEAD OF THE FRONT...BEFORE TURNING TOWARDS CLIMO ON FRIDAY
WITH HIGHS IN THE MID TO UPPER 80S AND OVERNIGHT LOWS GENERALLY IN
THE UPPER 60S THROUGH THE REMAINDER OF THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 804 AM EDT TUE JUL 24 2012
SCATTERED SHOWERS AND THUNDERSTORMS WERE ENTERING THE FORECAST AREA
FROM THE NORTHWEST AT THE START OF THE PERIOD...AND WILL CONTINUE TO
INCREASE IN COVERAGE. THEY WILL BRING LOCALIZED IFR TODAY. IF ENOUGH
DESTABILIZATION CAN OCCUR...SOME OF THE STORMS MAY BRING STRONG WINDS
AND POSSIBLY HAIL IN THE AFTERNOON. WILL EXPECT A RELATIVE LULL IN
PRECIP LATE THIS EVENING AND OVERNIGHT. HOWEVER...FOG WILL BE A
THREAT TONIGHT...ESPECIALLY IN VALLEY LOCATIONS IF CLOUDS BREAK UP.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...HAL
LONG TERM....MB
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
441 PM EDT TUE JUL 24 2012
.SYNOPSIS...
A COLD FRONT WILL DROP SOUTH ACROSS THE REGION TONIGHT...STALLING
ACROSS THE CAROLINAS ON WEDNESDAY. HIGH PRESSURE WILL BRIEFLY
BUILD IN FROM THE NORTH THROUGH WEDNESDAY NIGHT...BEFORE THE FRONT
SURGES BACK NORTH AS A WARM FRONT EARLY THURSDAY. ANOTHER COLD
FRONT CROSSES THE MID ATLANTIC OVER THE UPCOMING WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
SVR TSTM WATCHES 510 AND 513 ARE IN EFFECT FOR THE ENTIRE FA. SCT
SHWRS/TSTMS EXPECTED THIS AFTN/EVNG IN ASSOCIATION WITH UPSTREAM
MID-LVL ENERGY AND A PRE-FRONTAL TROF. COVERAGE IS STILL A
QUESTION AS WESTERLY LO-LVL FLOW IS NOT PARTICULARLY
FAVORABLE...BUT WILL CONTINUE 50-60% POPS ATTM. CONDITIONS
CONTINUE TO BE CONDUCIVE TO STRONG TO SVR STORMS THROUGHOUT THE FA
AS MLCAPE IS 3000-4000 J/KG...0-6 KM BULK SHEAR IS 30-35 KT...AND
LIFTED INDICES ARE AROUND -10 PER LATEST RAP ANALYSIS. MID
ATLANTIC REGION REMAINS IN SLIGHT RISK AREA FOR TODAY...WITH AKQ
CWA REMAINING HIGHLIGHTED IN HIGHEST WIND PROBABILITY AREA. WILL
CONTINUE TO REFLECT SEVERE WX THREAT IN HWO.
PRECIP WILL ADVANCE SE THROUGH THE REGION THIS EVNG...CLEARING BY
AROUND MIDNGT. COLD FROPA OCCURS TNGT WITH MSTLY CLR SKIES AND
TEMPS DROPPING INTO THE UPR 60S/LWR 70S.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
DRY CONDITIONS EXPECTED FOR THE REMAINDER OF THE WORK WEEK WITH A
DRIER AIR MASS IN PLACE. SFC HI PRES BLDS IN FROM THE NORTH WED
WITH DEWPTS DROPPING INTO THE LOW 60S AND HIGH TEMPS ONLY IN THE
UPR 80S TO NEAR 90. WARM FRONT PUSHES NORTH THROUGH THE AREA WED
NGT...WITH S/SW FLOW AND HOT CONDITIONS RETURNING THU. TEMPS WILL
CLIMB INTO THE MID TO UPR 90S...APPROACHING 100 OVER AREAS
ALONG/WEST OF I-95. HIGHS AGAIN IN THE MID TO UPR 90S FRI AHEAD OF
THE NEXT FRONTAL SYSTEM.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
BROAD UPR LVL TROUGH TO RMN ANCHOR OVR THE NE CONUS W/ RIDGE OVR THE
NATIONS MIDSECTION FOR THE EXTENDED PD...RESULTING IN NWLY FLO INTO
THE MDATLC RGN. TIMING SYSTEMS IN SUCH A PATTERN RMNG DIFFICULT. A
FNTL BNDRY IS SLO TO REACH THE CSTL CAROLINAS FRI NGT INTO SAT...AND
IS NOW FCST TO CONT MOVG SSE THROUGH SUN. WK SFC HI PRES TO SLIDE BY
N OF THE RGN LT WKND INTO MON/TUE.
OVRALL...CLR-PCLDY THROUGH THE PD. WILL CONT W/ CHC POPS E AND SE
FRI NGT INTO SAT...THEN HAVE SLGT CHC/CHC POPS (MNLY INLAND) MON AND
TUE AS WINDS BCM E THEN S EARLY NEXT WEEK. HI TEMPS IN THE L/M90S
FRI...U80S TO L90S SAT...THEN IN THE 80S TO ARND 90F SUN/MON/TUE.
LO TEMPS IN THE L/M70S.
&&
.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
AS OF 18Z...SCT TSTMS ARE EXPECTED ACROSS THE FORECAST AREA THIS
AFTN AND EARLY EVENING. SEVERE TSTM WATCH 510 COVERS RIC AND SBY TIL
22Z AND ANOTHER WATCH MAY BE ISSUED LATER THIS AFTN FOR THE REST OF
THE TAF SITES.
WILL HOLD OFF ON INCLUDING TSTMS IN THE TAFS UNTIL CONFIDENCE IN
TIMING IS HIGH. CURRENTLY THERE ARE TSTMS IN THE MOUNTAINS UPSTREAM
FROM RIC AND WITH THE WATCH ENDING AT 22Z...INCLUDED TEMPO GROUP
FROM 20-22Z THERE. SOME TAF SITES COULD MISS THE TSTMS AS COVERAGE
IS EXPECTED TO BE SCATTERED.
THE COLD FRONT MOVES THROUGH BETWEEN 00 AND 06Z AND BRINGS A WIND
SHIFT TO NW/N EXCEPT BECOMING N/NE AT ORF. VFR CONDITIONS WILL
CONTINUE THROUGH THE MORNING HOURS WITH WIND AND LOWERING DEW POINTS
INHIBITING FOG FORMATION. MOSTLY CLEAR SKIES ARE EXPECTED DURING THE
DAY WEDNESDAY.
OUTLOOK...DRY/VFR CONDITIONS WILL CONTINUE THURSDAY. OTHER THAN A
SLGT CHC FOR TSTMS FRIDAY AFTN...DRY WEATHER SHOULD PREVAIL THROUGH
THE WEEKEND. THE CHANCES FOR EARLY MORNING FOG APPEAR MINIMAL AT
THIS TIME.
&&
.MARINE...
WILL CONT W/ A (MARGINAL) SCA...MNLY FM AFT MDNGT INTO WED
MRNG...FOR THE CHES BAY AND ATLC WTRS. CDFNT TO SETTLE S ACRS THE
WTRS THROUGH THE EVE INTO THE OVRNGT HRS. PD OF NNW WNDS POST FNTL
XPCD...THOUGH RMNS UNCERTAIN AS TO JUST HOW MUCH OF A SURGE IN SPD
THERE WILL BE. A COOLER/DRIER AMS TO ARRIVE FM THE N OVR THE WARMER
WTRS...AND IF A MONTH OR TWO LATER...WOULD LIKELY BE A HIGHER PROB.
FOR NOW...CAPPING WINDS MNLY FM 15 TO 20 KT. CORRESPONDING
WAVES/SEAS TO RISE TO LWR END OF SCA (WHICH IS 4 FT ON THE BAY/5 FT
ON THE OCN). AFT A PD OF LGT/VRB WNDS FM LT WED INTO WED
NGT...MODELS HAVE WNDS BMCG SSW AGN BY THU WHL INCRSG IN SPD BACK TO
ABT 10 TO 15 KT. ANOTHER FNT TO CROSS THE WTRS LT FRI INTO SAT MRNG.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NCZ012>017-
030>032.
VA...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR VAZ087>097.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 AM EDT WEDNESDAY FOR ANZ650-652-
654-656-658.
SMALL CRAFT ADVISORY UNTIL 11 AM EDT WEDNESDAY FOR ANZ630>632-
634.
&&
$$
SYNOPSIS...MAS/MAM
NEAR TERM...MAS
SHORT TERM...MAS
LONG TERM...ALB
AVIATION...LSA
MARINE...ALB
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
345 PM EDT TUE JUL 24 2012
.SYNOPSIS...
A COLD FRONT WILL DROP SOUTH ACROSS THE REGION TONIGHT...STALLING
ACROSS THE CAROLINAS ON WEDNESDAY. HIGH PRESSURE WILL BRIEFLY
BUILD IN FROM THE NORTH THROUGH WEDNESDAY NIGHT...BEFORE THE FRONT
SURGES BACK NORTH AS A WARM FRONT EARLY THURSDAY. ANOTHER COLD
FRONT CROSSES THE MID ATLANTIC OVER THE UPCOMING WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
SVR TSTM WATCH 510 IS IN EFFECT FOR NW HALF OF THE FA UNTIL 8 PM.
SCT SHWRS/TSTMS EXPECTED THIS AFTN/EVNG IN ASSOCIATION WITH
UPSTREAM MID-LVL ENERGY AND A PRE-FRONTAL TROF. COVERAGE IS STILL
A QUESTION AS WESTERLY LO-LVL FLOW IS NOT PARTICULARLY
FAVORABLE...BUT WILL CONTINUE 50-60% POPS ATTM. CONDITIONS
CONTINUE TO BE CONDUCIVE TO STRONG TO SVR STORMS THROUGHOUT THE FA
AS MLCAPE IS 3000-4000 J/KG...0-6 KM BULK SHEAR IS 30-35 KT...AND
LIFTED INDICES ARE AROUND -10 PER LATEST RAP ANALYSIS. MID
ATLANTIC REGION REMAINS IN SLIGHT RISK AREA FOR TODAY...WITH AKQ
CWA REMAINING HIGHLIGHTED IN HIGHEST WIND PROBABILITY AREA. WILL
CONTINUE TO REFLECT SEVERE WX THREAT IN HWO.
PRECIP WILL ADVANCE SE THROUGH THE REGION THIS EVNG...CLEARING BY
AROUND MIDNGT. COLD FROPA OCCURS TNGT WITH MSTLY CLR SKIES AND
TEMPS DROPPING INTO THE UPR 60S/LWR 70S.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
DRY CONDITIONS EXPECTED FOR THE REMAINDER OF THE WORK WEEK WITH A
DRIER AIR MASS IN PLACE. SFC HI PRES BLDS IN FROM THE NORTH WED
WITH DEWPTS DROPPING INTO THE LOW 60S AND HIGH TEMPS ONLY IN THE
UPR 80S TO NEAR 90. WARM FRONT PUSHES NORTH THROUGH THE AREA WED
NGT...WITH S/SW FLOW AND HOT CONDITIONS RETURNING THU. TEMPS WILL
CLIMB INTO THE MID TO UPR 90S...APPROACHING 100 OVER AREAS
ALONG/WEST OF I-95. HIGHS AGAIN IN THE MID TO UPR 90S FRI AHEAD OF
THE NEXT FRONTAL SYSTEM.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
BROAD UPR LVL TROUGH TO RMN ANCHOR OVR THE NE CONUS W/ RIDGE OVR THE
NATIONS MIDSECTION FOR THE EXTENDED PD...RESULTING IN NWLY FLO INTO
THE MDATLC RGN. TIMING SYSTEMS IN SUCH A PATTERN RMNG DIFFICULT. A
FNTL BNDRY IS SLO TO REACH THE CSTL CAROLINAS FRI NGT INTO SAT...AND
IS NOW FCST TO CONT MOVG SSE THROUGH SUN. WK SFC HI PRES TO SLIDE BY
N OF THE RGN LT WKND INTO MON/TUE.
OVRALL...CLR-PCLDY THROUGH THE PD. WILL CONT W/ CHC POPS E AND SE
FRI NGT INTO SAT...THEN HAVE SLGT CHC/CHC POPS (MNLY INLAND) MON AND
TUE AS WINDS BCM E THEN S EARLY NEXT WEEK. HI TEMPS IN THE L/M90S
FRI...U80S TO L90S SAT...THEN IN THE 80S TO ARND 90F SUN/MON/TUE.
LO TEMPS IN THE L/M70S.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
AS OF 18Z...SCT TSTMS ARE EXPECTED ACROSS THE FORECAST AREA THIS
AFTN AND EARLY EVENING. SEVERE TSTM WATCH 510 COVERS RIC AND SBY TIL
22Z AND ANOTHER WATCH MAY BE ISSUED LATER THIS AFTN FOR THE REST OF
THE TAF SITES.
WILL HOLD OFF ON INCLUDING TSTMS IN THE TAFS UNTIL CONFIDENCE IN
TIMING IS HIGH. CURRENTLY THERE ARE TSTMS IN THE MOUNTAINS UPSTREAM
FROM RIC AND WITH THE WATCH ENDING AT 22Z...INCLUDED TEMPO GROUP
FROM 20-22Z THERE. SOME TAF SITES COULD MISS THE TSTMS AS COVERAGE
IS EXPECTED TO BE SCATTERED.
THE COLD FRONT MOVES THROUGH BETWEEN 00 AND 06Z AND BRINGS A WIND
SHIFT TO NW/N EXCEPT BECOMING N/NE AT ORF. VFR CONDITIONS WILL
CONTINUE THROUGH THE MORNING HOURS WITH WIND AND LOWERING DEW POINTS
INHIBITING FOG FORMATION. MOSTLY CLEAR SKIES ARE EXPECTED DURING THE
DAY WEDNESDAY.
OUTLOOK...DRY/VFR CONDITIONS WILL CONTINUE THURSDAY. OTHER THAN A
SLGT CHC FOR TSTMS FRIDAY AFTN...DRY WEATHER SHOULD PREVAIL THROUGH
THE WEEKEND. THE CHANCES FOR EARLY MORNING FOG APPEAR MINIMAL AT
THIS TIME.
&&
.MARINE...
WILL CONT W/ A (MARGINAL) SCA...MNLY FM AFT MDNGT INTO WED
MRNG...FOR THE CHES BAY AND ATLC WTRS. CDFNT TO SETTLE S ACRS THE
WTRS THROUGH THE EVE INTO THE OVRNGT HRS. PD OF NNW WNDS POST FNTL
XPCD...THOUGH RMNS UNCERTAIN AS TO JUST HOW MUCH OF A SURGE IN SPD
THERE WILL BE. A COOLER/DRIER AMS TO ARRIVE FM THE N OVR THE WARMER
WTRS...AND IF A MONTH OR TWO LATER...WOULD LIKELY BE A HIGHER PROB.
FOR NOW...CAPPING WINDS MNLY FM 15 TO 20 KT. CORRESPONDING
WAVES/SEAS TO RISE TO LWR END OF SCA (WHICH IS 4 FT ON THE BAY/5 FT
ON THE OCN). AFT A PD OF LGT/VRB WNDS FM LT WED INTO WED
NGT...MODELS HAVE WNDS BMCG SSW AGN BY THU WHL INCRSG IN SPD BACK TO
ABT 10 TO 15 KT. ANOTHER FNT TO CROSS THE WTRS LT FRI INTO SAT MRNG.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NCZ012>017-
030>032.
VA...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR VAZ087>097.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 AM EDT WEDNESDAY FOR ANZ650-652-
654-656-658.
SMALL CRAFT ADVISORY UNTIL 11 AM EDT WEDNESDAY FOR ANZ630>632-
634.
&&
$$
SYNOPSIS...MAS/MAM
NEAR TERM...MAS
SHORT TERM...MAS
LONG TERM...ALB
AVIATION...LSA
MARINE...ALB
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
342 PM EDT TUE JUL 24 2012
.SYNOPSIS...
A COLD FRONT, MOVING SOUTHWARD THROUGH THE UPPER OHIO VALLEY, CAN
STILL CAUSE SCATTERED THUNDERSTORMS MAINLY SOUTH OF PITTSBURGH
EARLY THIS EVENING. ANOTHER FRONT WILL BRING SCATTERED
THUNDERSTORMS WEDNESDAY NIGHT, THURSDAY, AND FRIDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
TREND OF RECENT RADAR DATA AND HRRR MODEL OUTPUT SHOWS SCATTERED
THUNDERSTORMS WILL BE ENDING THIS EVENING, AS THE PASSING DEW
POINT FRONT CONTINUES MOVING SOUTHEASTWARD THROUGH THE UPPER OHIO
VALLEY.
HAVE MADE ADDED ADJUSTMENTS TO LATE AFTERNOON AND EVENING
TEMPERATURES BASED ON EVAPORATIVE-COOLING EFFECTS OF RECENT
THUNDERSTORM RAINS.
LIKEWISE, HAVE ADDED LATE NIGHT PATCHY FOG TO AREAS SOUTH OF THE
NEW PHILADELPHIA OHIO, AND PITTSBURGH AND INDIANA PENNSYLVANIA
CORRIDOR, DUE TO EXPECTED LOW LEVEL CONDENSATION AS RAIN-MOISTENED
SURFACE LAYER NOCTURNALLY COOLS TO SATURATION.
FORECASTED LOW TEMPERATURES AND DEW POINTS TONIGHT USING BLEND OF
GFS MOS AND NAM MODEL OUTPUT.
RECENT SREF MODEL OUTPUT SHOWS THE DEW POINT FRONT WILL BE ACROSS
WEST VIRGINIA WEDNESDAY, SO EXPECT RAINFREE CONDITIONS. THIS WILL
PROMOTE A GOOD BIT OF SUNSHINE, AND SO WARMER THAN NORMAL
TEMPERATURES, PER BLEND OF NAM AND GFS MOS.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
WITH SREF MODEL OUTPUT SHOWING LOW LEVEL WINDS BECOMING SOUTH AND
SOUTHWEST ACROSS THE UPPER OHIO VALLEY WEDNESDAY NIGHT, THE
SURFACE LAYER WILL BECOME HUMID.
ADDITIONALLY, MOST SREF MODEL MEMBERS SHOW FRONTOGENESIS ACROSS
THE GREAT LAKES WEDNESDAY NIGHT, DUE TO AN UPPER LEVEL JET MAX,
THAT WILL CONTRIBUTE TO THE DEVELOPMENT OF A LOW PRESSURE CENTER
NEAR WISCONSIN. THE RESULTING COLD FRONT WILL THEN BEGIN TO MOVE
VERY SLOWLY SOUTHEASTWARD ACROSS THE UPPER OHIO VALLEY THURSDAY
INTO FRIDAY.
ONSET OF INCREASED PREFRONTAL CONVERGENCE WITHIN A HUMID AND
UNSTABLE AIR MASS, WILL PRODUCE A CHANCE OF THUNDERSTORMS LATE
WEDNESDAY NIGHT INTO FRIDAY. CONCUR WITH SPC REGARDING A SLIGHT
RISK OF SEVERE THUNDERSTORMS, DUE TO STRONGER WINDS ALOFT
RESULTING IN INCREASED VERTICAL WIND SHEAR.
REGARDING TEMPERATURES, BLEND OF NAM AND GFS MOS SHOW SOME SPOTS
WITH HIGHS OF 90 THURSDAY. HIGHS FRIDAY WILL BE A TAD LESS. LOWS
WEDNESDAY NIGHT AND THURSDAY NIGHT WILL BE MAINLY IN THE UPPER 60S
TO LOWER 70S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
LATEST MEDIUM RANGE MODELS MOVE A SHORT WAVE TROUGH OVER THE GREAT
LAKES EAST TO THE NEW ENGLAND COAST BY SUNDAY NIGHT. SCATTERED
SHOWERS AND THUNDERSTORMS WILL CONTINUE UNTIL A COLD FRONT PUSHES
SOUTH OF THE REGION SATURDAY NIGHT.
SURFACE HIGH PRESSURE SHOULD BUILD INTO THE REGION AND PROVIDE DRY
WEATHER SUNDAY AND MONDAY. ISOLATED SHOWERS AND STORMS ARE
FORECAST TO RETURN BY TUESDAY, AS THE NEXT SYSTEM APPROACHES FROM
THE MIDWEST.
FORECAST TEMPERATURES ARE CLOSE TO HPC GUIDANCE AND WILL BE NEAR
NORMAL THROUGH SUNDAY...WARMING TO AROUND 5 DEGREES ABOVE NORMAL
FOR MONDAY AND TUESDAY.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
PER RECENT SURFACE AND RADAR DATA, COUPLED WITH HRRR MODEL OUTPUT,
MAINTAINED MENTION OF TEMPO IFR/MVFR RESTRICTIONS FOR SHOWERS AND
THUNDERSTORMS KPIT AND SOUTH THROUGH 21Z. SURFACE WINDS WILL BE
NORTHWEST 10 KT GUSTING TO 20 KT...WITH HIGHER GUSTS POSSIBLE NEAR
THUNDERSTORMS.
POSTFRONTAL DRYING WILL PROMOTE VFR BEGINNING THIS EVENING.
POTENTIAL EXISTS FOR LATE NIGHT PATCHY FOG, BUT NOT ENOUGH
CONFIDENCE TO MENTION IN TAFS, EXCEPT FOR TEMPO 3SM AT KLBE AFT 08Z.
NORTHWEST SURFACE WINDS SHOULD DIMINISH TO LIGHT AND VARIABLE LATE
TONIGHT...THEN BECOME SOUTHERLY 5 TO 10 KT WEDNESDAY.
OUTLOOK...WEDNESDAY NIGHT THROUGH SUNDAY...
GENERALLY VFR WILL PREVAIL. POTENTIAL EXISTS FOR OCCASIONAL
RESTRICTIONS IN THUNDERSTORMS LATE THURSDAY THROUGH SATURDAY EVENING
AS A SERIES OF WAVES TRACK ALONG A FRONTAL BOUNDARY STRETCHED ACROSS
THE OHIO VALLEY. A SURFACE RIDGE SHOULD PROVIDE DRY WEATHER SUNDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
218 PM EDT TUE JUL 24 2012
.SYNOPSIS...
A COLD FRONT, MOVING SOUTHWARD THROUGH THE UPPER OHIO VALLEY, CAN
STILL CAUSE SCATTERED THUNDERSTORMS MAINLY SOUTH OF PITTSBURGH, WITH GUSTY
WIND, HAIL, AND HEAVY RAIN, INTO EARLY EVENING. ANOTHER FRONT
WILL BRING SCATTERED THUNDERSTORMS WEDNESDAY NIGHT, THURSDAY AND
FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
RECENT RADAR AND SURFACE DATA SHOW ADDITIONAL PREFRONTAL
SCATTERED THUNDERSTORMS WILL BE MOVING SOUTHEASTWARD ACROSS THE
UPPER OHIO VALLEY, MAINLY SOUTH OF NEW PHILADELPHIA OHIO, AND
PITTSBURGH AND INDIANA PENNSYLVANIA. SOME STORMS CAN HAVE GUSTY
WIND, HAIL, HEAVY RAIN, AND FREQUENT LIGHTNING. SPC GUIDANCE
CONTINUES TO SHOW STORMS CAN REACH SEVERE LIMITS.
HAVE MADE ADDED ADJUSTMENTS TO AFTERNOON AND EVENING TEMPERATURES
BASED ON EVAPORATIVE-COOLING EFFECTS OF RECENT THUNDERSTORM RAINS.
LIKEWISE, HAVE ADDED LATE NIGHT PATCHY FOG TO AREAS SOUTH OF THE
NEW PHILADELPHIA OHIO, AND PITTSBURGH AND INDIANA PENNSYLVANIA
CORRIDOR, DUE TO EXPECTED LOW LEVEL CONDENSATION AS RAIN-MOISTENED
SURFACE LAYER NOCTURNALLY COOLS TO SATURATION.
FORECASTED LOW TEMPERATURES AND DEW POINTS TONIGHT USING BLEND OF
GFS MOS AND NAM MODEL OUTPUT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
RECENT SREF MODEL OUTPUT SHOWS THE DEW POINT FRONT WILL BE ACROSS
WEST VIRGINIA WEDNESDAY, SO EXPECT RAINFREE CONDITIONS. THIS WILL
PROMOTE A GOOD BIT OF SUNSHINE, AND SO WARMER THAN NORMAL
TEMPERATURES, PER BLEND OF NAM AND GFS MOS.
WITH LOW LEVEL WINDS BECOMING SOUTH AND SOUTHWEST WEDNESDAY NIGHT,
THE SURFACE LAYER WILL BECOME HUMID ACROSS THE UPPER OHIO VALLEY.
MOST SREF MODEL MEMBERS SHOW FRONTOGENESIS ACROSS THE GREAT LAKES
WEDNESDAY NIGHT, DUE TO AN UPPER LEVEL JET MAX, THAT WILL
CONTRIBUTE TO THE DEVELOPMENT OF A LOW PRESSURE CENTER NEAR
WISCONSIN. THE RESULTING COLD FRONT WILL THEN MOVE SLOWLY
SOUTHEASTWARD ACROSS THE UPPER OHIO VALLEY THURSDAY INTO FRIDAY.
ONSET OF THIS INCREASED CONVERGENCE WITHIN A HUMID AND UNSTABLE
AIR MASS, WILL PRODUCE A CHANCE OF THUNDERSTORMS LATE WEDNESDAY
NIGHT INTO FRIDAY. CONCUR WITH SPC REGARDING A SLIGHT RISK OF
SEVERE THUNDERSTORMS, DUE TO INCREASED VERTICAL WIND SHEAR.
REGARDING TEMPERATURES, BLEND OF NAM AND GFS MOS SHOW SOME SPOTS
WITH HIGHS OF 90 THURSDAY. HIGHS FRIDAY WILL BE A TAD LESS. LOWS
WEDNESDAY NIGHT AND THURSDAY NIGHT WILL BE MAINLY IN THE UPPER 60S
TO LOWER 70S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
LATEST MEDIUM RANGE MODELS STILL DIG A SHORT WAVE TROUGH ACROSS THE
GREAT LAKES REGION FRIDAY AND SLOWLY MOVE THE TROUGH AXIS MOVE EAST
TO THE NEW ENGLAND COAST BY MONDAY.
KEPT SCATTERED SHOWERS AND THUNDERSTORMS IN THE FORECAST FRIDAY
NIGHT AND SATURDAY...WITH DRY WEATHER EXPECTED SUNDAY INTO MONDAY
AS THE UPPER TROUGH MOVES EAST AND A WEAK SURFACE HIGH BRINGS
DRIER AIR IN FROM THE NORTHWEST.
FORECAST TEMPERATURES ARE CLOSE TO HPC GUIDANCE AND NEAR NORMAL
THROUGH THE EXTENDED PERIOD.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
PER RECENT SURFACE AND RADAR DATA, COUPLED WITH HRRR MODEL OUTPUT,
MAINTAINED MENTION OF TEMPO MVFR RESTRICTIONS WITH SHOWERS AND
SCATTERED THUNDERSTORMS KZZV-KPIT AND SOUTH. SURFACE WINDS WILL
BECOME NORTHWEST NEAR 10 KTS WITH GUSTS TO 20 KTS. HIGHER GUSTS
POSSIBLE NEAR THUNDERSTORMS.
POSTFRONTAL DRYING WILL PROMOTE VFR STARTING THIS EVENING.
POTENTIAL FOR LATE NIGHT PATCHY FOG MAY PRODUCE RESTRICTIONS, BUT
NOT ENOUGH CONFIDENCE TO MENTION IN TAF.
OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
GEN VFR...BUT WITH PERIODIC CHCS FOR TSRA/ASSOCIATED RESTRICTIONS
ARE EXPECTED FOR THE REMAINDER OF THE WEEK AS A SERIES OF SHRTWVS
TRACK ACRS THE UPR OH VALLEY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
206 PM EDT TUE JUL 24 2012
.SYNOPSIS...
A COLD FRONT WILL DROP SOUTH ACROSS THE REGION TONIGHT...STALLING
ACROSS THE CAROLINAS ON WEDNESDAY. HIGH PRESSURE WILL BRIEFLY
BUILD IN FROM THE NORTH THROUGH WEDNESDAY NIGHT...BEFORE THE FRONT
SURGES BACK NORTH AS A WARM FRONT EARLY THURSDAY. ANOTHER COLD
FRONT CROSSES THE MID ATLANTIC OVER THE UPCOMING WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
SCT SHWRS/TSTMS EXPECTED THIS AFTN/EVNG IN ASSOCIATION WITH
UPSTREAM MID-LVL ENERGY AND A PRE-FRONTAL TROF. COVERAGE IS STILL
A QUESTION AS WESTERLY LO-LVL FLOW IS NOT PARTICULARLY
FAVORABLE...BUT WILL CONTINUE 50% POPS ATTM. CONDITIONS CONTINUE TO
BE CONDUCIVE TO STRONG TO SVR STORMS THROUGHOUT THE FA AS MLCAPE
IS 3000-4000 J/KG...0-6 KM BULK SHEAR IS 30-35 KT...AND LIFTED
INDICES ARE AROUND -10 PER LATEST RAP ANALYSIS. MID ATLANTIC
REGION REMAINS IN SLIGHT RISK AREA FOR TODAY...WITH AKQ CWA
REMAINING HIGHLIGHTED IN HIGHEST WIND PROBABILITY AREA. WILL
CONTINUE TO REFLECT SEVERE WX THREAT IN HWO.
OTHER BIG STORY TODAY WILL BE HOTTER TEMPS...EXACERBATED BY
COMPRESSIONAL HEATING AHEAD OF APPROACHING COLD FRONT TO THE
NORTH. FORECAST MAXIMA REMAIN IN THE MID 90S FOR MOST OF THE CWA,
AND WITH JUST ENOUGH AFTN MIXING TO DROP DEWPOINTS BACK INTO THE
UPPER 60S INLAND, CONCERN FOR HEAT ADVISORY REMAINS MAINLY OVER
THE SE VA/NE NC COASTAL PLAIN. GIVEN DEWPOINTS EXPECTED TO REMAIN
IN THE LOWER 70S, A PERIOD OF HEAT ADVY CRITERIA WILL LKLY BE
ACHIEVED OVER HAMPTON ROADS/TIDEWATER AREA, INCLUDING NC COUNTIES.
ACCORDINGLY, HV GONE AHEAD WITH HEAT ADVISORY FOR THESE AREAS.
ELSEWHERE, EXPECT APPARENT TEMP VALUES TO VARY A BIT LESS FROM AIR
TEMP, WITH HEAT INDICES HANGING RIGHT ~100 F FOR EARLY AFTN.
SCT CONVECTION WILL SLIDE TOWARDS SOUTHERN PORTIONS OF CWA BY EARLY
THIS EVENING, WITH THE FRONT TO DROP SOUTH ACROSS THE AREA IN BACK
DOOR FRONT ORIENTATION OVERNIGHT. GRADUALLY DIMINISHED POPS AFTER
SUNSET, WITH GRADUAL CLEARING AND RAIN CHCS ENDING AFTER MIDNIGHT
FOR ALL BUT FAR SE CWA AS COOLER/DRIER AIR SLOWLY OOZE SOUTH
OVERNIGHT INTO WEDNESDAY MORNING. LOOK FOR EARLY MORNING LOWS WED
INTO THE U60S ACROSS THE NORTH/MID 70S SOUTH.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
WEAK CAA CONTINUES WED AS DEWPOINTS DROP BACK INTO THE L0W 60S (AT
LEAST) IN MOST SPOTS. PLEASANT DAY WXWISE WITH HIGHS ONLY IN THE
UPR 80S TO ~90 UNDER A SUNNY TO MOSTLY SUNNY SKY. THE FRONT THAT
DROPS SOUTH ACROSS THE AREA LATE TONIGHT AND WED, WILL LIFT BACK
NORTH OF THE REGION AS A WARM FRONT LATE WEDNESDAY NIGHT INTO THU.
RESULTANT VEERING OF WINDS AROUND TO THE S/SW WILL YIELD RETURN OF
HEAT FOR THU. MAXIMA ARE EXPECTED TO QUICKLY SURGE BACK INTO THE
MID 90S. RAIN CHCS REMAIN RATHER LOW DURING THIS PERIOD. THOUGH
HAVE ALLOWED FOR SLIGHT CHC WEST OF RIC ON WED IN ASSN WITH
ADDITIONAL SPOKES OF S/W ENERGY DROPPING SE ALONG PERIPHERY OF
RETROGRADING UPPER ANTICYCLONE. WENT WITH SLIGHT CHC/LOW CHC ON
THURSDAY WITH ISO- WIDELY SCT TSRA POSSIBLE ALONG DEVELOPING LEE
SIDE TROUGH.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
BROAD UPR LVL TROUGH TO RMN ANCHOR OVR THE NE CONUS W/ RIDGE OVR THE
NATIONS MIDSECTION FOR THE EXTENDED PD...RESULTING IN NWLY FLO INTO
THE MDATLC RGN. TIMING SYSTEMS IN SUCH A PATTERN DIFFICULT FROM THIS
FAR OUT. CDFNT TO CROSS THE RGN THU NGT INTO FRI...THEN LINGER OVR
THE CAROLINAS. SERIES OF WK AREAS OF SFC LO PRES FCST TO TRACK ALG
THE LINGERING BNDRY. OVRALL...MNLY PCLDY W/ PRIMARILY DIURNAL
POPS...ESP FRI AND AGN SAT. TEMPS AVGG A FEW DEGS F ABV NRML (THOUGH
RMNG LARGELY W/ +1 STANDARD DEVIATION OF NRML). HI TEMPS IN THE
L/M90S FRI...U80S TO L90S SAT AND SUN...AND 80S MON. LO TEMPS IN THE
M/U70S THU NGT/FRI NGT...AND L/M70S SAT NGT/SUN NGT.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 18Z...SCT TSTMS ARE EXPECTED ACROSS THE FORECAST AREA THIS
AFTN AND EARLY EVENING. SEVERE TSTM WATCH 510 COVERS RIC AND SBY TIL
22Z AND ANOTHER WATCH MAY BE ISSUED LATER THIS AFTN FOR THE REST OF
THE TAF SITES.
WILL HOLD OFF ON INCLUDING TSTMS IN THE TAFS UNTIL CONFIDENCE IN
TIMING IS HIGH. CURRENTLY THERE ARE TSTMS IN THE MOUNTAINS UPSTREAM
FROM RIC AND WITH THE WATCH ENDING AT 22Z...INCLUDED TEMPO GROUP
FROM 20-22Z THERE. SOME TAF SITES COULD MISS THE TSTMS AS COVERAGE
IS EXPECTED TO BE SCATTERED.
THE COLD FRONT MOVES THROUGH BETWEEN 00 AND 06Z AND BRINGS A WIND
SHIFT TO NW/N EXCEPT BECOMING N/NE AT ORF. VFR CONDITIONS WILL
CONTINUE THROUGH THE MORNING HOURS WITH WIND AND LOWERING DEW POINTS
INHIBITING FOG FORMATION. MOSTLY CLEAR SKIES ARE EXPECTED DURING THE
DAY WEDNESDAY.
OUTLOOK...DRY/VFR CONDITIONS WILL CONTINUE THURSDAY. OTHER THAN A
SLGT CHC FOR TSTMS FRIDAY AFTN...DRY WEATHER SHOULD PREVAIL THROUGH
THE WEEKEND. THE CHANCES FOR EARLY MORNING FOG APPEAR MINIMAL AT
THIS TIME.
&&
.MARINE...
SW WINDS TODAY WILL BECOME BREEZY BY THIS AFTERNOON AS A COLD FRONT
APPROACHES THE REGION. EXPECT WINDS TO SHIFT TO THE W THIS EVENING...
BECOMING NW-N BEHIND THE FRONT AS IT TRACKS FROM NORTHWEST TO
SOUTHEAST ACROSS THE WATERS. CAA STILL DOES NOT APPEAR TO BE VERY
STRONG BUT A PROLONGED PERIOD OF NLY WINDS INTO WED HAS PROMPTED
THE ISSUANCE OF SCA FLAGS THROUGH EARLY WED MORNING. WINDS OVER
THE BAY/SOUND SHOULD TOP OUT AROUND 25 KT WITH WAVES OF 2-3 FT AND
UP TO 4 FT AT TIMES. NRN OCEAN WATERS WILL FIRST EXPERIENCE GUSTS
OF 25 KT AND SEAS OF 3-5 FT...WHILE SRN OCEAN WATERS WILL SEE
GUSTS OF 25 KT AFTER MIDNIGHT AND SEAS OF GENERALLY 2-4 FT.
HIGH PRESSURE BUILDS IN FROM THE NORTHWEST ON WED AND THE GRADIENT
RELAXES. WINDS WILL THEN VEER TO THE S-SW LATE WED NIGHT THROUGH FRI
AS A LOW PRESSURE SYSTEM MOVING ACROSS CENTRAL PENNSYLVANIA DRAGS A
WEAK FRONT ACROSS THE WATERS THURSDAY NIGHT INTO FRIDAY MORNING.
SEAS WILL GENERALLY BE 2-3 FT (OCCASIONALLY 4 FT NEAR 20 NM) AND
WAVES 1-2 FT (INCREASING TO 3 FT AT TIMES...ESPECIALLY DURING THE
OVERNIGHT HOURS DUE TO DIURNAL INSTABILITY EFFECTS).
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NCZ012>017-
030>032.
VA...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR VAZ087>097.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 9 AM EDT
WEDNESDAY FOR ANZ638-650-652-654.
SMALL CRAFT ADVISORY FROM 2 AM TO 9 AM EDT WEDNESDAY FOR
ANZ633-656-658.
SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
WEDNESDAY FOR ANZ630>632-634.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAS/MAM
SHORT TERM...MAS/MAM
LONG TERM...ALB
AVIATION...LSA
MARINE...BMD
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1214 PM EDT TUE JUL 24 2012
.SYNOPSIS...
A COLD FRONT WILL DROP SOUTH ACROSS THE REGION TONIGHT...STALLING
ACROSS THE CAROLINAS ON WEDNESDAY. HIGH PRESSURE WILL BRIEFLY
BUILD IN FROM THE NORTH THROUGH WEDNESDAY NIGHT...BEFORE THE FRONT
SURGES BACK NORTH AS A WARM FRONT EARLY THURSDAY. ANOTHER COLD
FRONT CROSSES THE MID ATLANTIC OVER THE UPCOMING WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
SCT SHWRS/TSTMS EXPECTED THIS AFTN/EVNG IN ASSOCIATION WITH
UPSTREAM MID-LVL ENERGY AND A PRE-FRONTAL TROF. COVERAGE IS STILL
A QUESTION AS WESTERLY LO-LVL FLOW IS NOT PARTICULARLY
FAVORABLE...BUT WILL CONTINUE 50% POPS ATTM. CONDITIONS CONTINUE TO
BE CONDUCIVE TO STRONG TO SVR STORMS THROUGHOUT THE FA AS MLCAPE
IS 3000-4000 J/KG...0-6 KM BULK SHEAR IS 30-35 KT...AND LIFTED
INDICES ARE AROUND -10 PER LATEST RAP ANALYSIS. MID ATLANTIC
REGION REMAINS IN SLIGHT RISK AREA FOR TODAY...WITH AKQ CWA
REMAINING HIGHLIGHTED IN HIGHEST WIND PROBABILITY AREA. WILL
CONTINUE TO REFLECT SEVERE WX THREAT IN HWO.
OTHER BIG STORY TODAY WILL BE HOTTER TEMPS...EXACERBATED BY
COMPRESSIONAL HEATING AHEAD OF APPROACHING COLD FRONT TO THE
NORTH. FORECAST MAXIMA REMAIN IN THE MID 90S FOR MOST OF THE CWA,
AND WITH JUST ENOUGH AFTN MIXING TO DROP DEWPOINTS BACK INTO THE
UPPER 60S INLAND, CONCERN FOR HEAT ADVISORY REMAINS MAINLY OVER
THE SE VA/NE NC COASTAL PLAIN. GIVEN DEWPOINTS EXPECTED TO REMAIN
IN THE LOWER 70S, A PERIOD OF HEAT ADVY CRITERIA WILL LKLY BE
ACHIEVED OVER HAMPTON ROADS/TIDEWATER AREA, INCLUDING NC COUNTIES.
ACCORDINGLY, HV GONE AHEAD WITH HEAT ADVISORY FOR THESE AREAS.
ELSEWHERE, EXPECT APPARENT TEMP VALUES TO VARY A BIT LESS FROM AIR
TEMP, WITH HEAT INDICES HANGING RIGHT ~100 F FOR EARLY AFTN.
SCT CONVECTION WILL SLIDE TOWARDS SOUTHERN PORTIONS OF CWA BY EARLY
THIS EVENING, WITH THE FRONT TO DROP SOUTH ACROSS THE AREA IN BACK
DOOR FRONT ORIENTATION OVERNIGHT. GRADUALLY DIMINISHED POPS AFTER
SUNSET, WITH GRADUAL CLEARING AND RAIN CHCS ENDING AFTER MIDNIGHT
FOR ALL BUT FAR SE CWA AS COOLER/DRIER AIR SLOWLY OOZE SOUTH
OVERNIGHT INTO WEDNESDAY MORNING. LOOK FOR EARLY MORNING LOWS WED
INTO THE U60S ACROSS THE NORTH/MID 70S SOUTH.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
WEAK CAA CONTINUES WED AS DEWPOINTS DROP BACK INTO THE L0W 60S (AT
LEAST) IN MOST SPOTS. PLEASANT DAY WXWISE WITH HIGHS ONLY IN THE
UPR 80S TO ~90 UNDER A SUNNY TO MOSTLY SUNNY SKY. THE FRONT THAT
DROPS SOUTH ACROSS THE AREA LATE TONIGHT AND WED, WILL LIFT BACK
NORTH OF THE REGION AS A WARM FRONT LATE WEDNESDAY NIGHT INTO THU.
RESULTANT VEERING OF WINDS AROUND TO THE S/SW WILL YIELD RETURN OF
HEAT FOR THU. MAXIMA ARE EXPECTED TO QUICKLY SURGE BACK INTO THE
MID 90S. RAIN CHCS REMAIN RATHER LOW DURING THIS PERIOD. THOUGH
HAVE ALLOWED FOR SLIGHT CHC WEST OF RIC ON WED IN ASSN WITH
ADDITIONAL SPOKES OF S/W ENERGY DROPPING SE ALONG PERIPHERY OF
RETROGRADING UPPER ANTICYCLONE. WENT WITH SLIGHT CHC/LOW CHC ON
THURSDAY WITH ISO- WIDELY SCT TSRA POSSIBLE ALONG DEVELOPING LEE
SIDE TROUGH.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
BROAD UPR LVL TROUGH TO RMN ANCHOR OVR THE NE CONUS W/ RIDGE OVR THE
NATIONS MIDSECTION FOR THE EXTENDED PD...RESULTING IN NWLY FLO INTO
THE MDATLC RGN. TIMING SYSTEMS IN SUCH A PATTERN DIFFICULT FROM THIS
FAR OUT. CDFNT TO CROSS THE RGN THU NGT INTO FRI...THEN LINGER OVR
THE CAROLINAS. SERIES OF WK AREAS OF SFC LO PRES FCST TO TRACK ALG
THE LINGERING BNDRY. OVRALL...MNLY PCLDY W/ PRIMARILY DIURNAL
POPS...ESP FRI AND AGN SAT. TEMPS AVGG A FEW DEGS F ABV NRML (THOUGH
RMNG LARGELY W/ +1 STANDARD DEVIATION OF NRML). HI TEMPS IN THE
L/M90S FRI...U80S TO L90S SAT AND SUN...AND 80S MON. LO TEMPS IN THE
M/U70S THU NGT/FRI NGT...AND L/M70S SAT NGT/SUN NGT.
&&
.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
UPDATE...POTENTIAL FOR FOG IS LOW FOR TONIGHT AS WINDS HOVER AROUND
10 KT OVERNIGHT. HOWEVER...KSBY COULD SEE SOME REDUCTIONS TO
VISIBILITIES BUT ANY LIMITATIONS SHOULD STAY WITHIN MVFR THRESHOLDS.
OTHERWISE...TAF TRENDS APPEAR TO BE ON TRACK FOR TODAY AND TONIGHT.
PREVIOUS DISCUSSION...SOUTHWEST WINDS OF 5-10 KT OVERNIGHT WILL
PREVENT FOG DEVELOPMENT TOWARD DAYBREAK THIS MORNING. OVERALL...HIGH
CLOUDS WILL STREAM OVER THE REGION THIS MORNING...GRADUALLY LOWERING
AND THICKENING THROUGH THE DAY AS A COLD FRONT APPROACHES FROM THE
NORTHWEST AND TRACKS TO THE SOUTHEAST THIS EVENING INTO TONIGHT.
EXPECT THUNDERSTORMS TO DEVELOP THIS AFTERNOON...PRIMARILY AFTER
23/1800Z. THE SURFACE PRESSURE GRADIENT WILL TIGHTEN AHEAD OF THE
FRONT...RESULTING IN BREEZY SOUTHWEST WINDS WITH GUSTS OF 20-25 KT
THROUGHOUT THE AFTERNOON AND EARLY EVENING HOURS. ONCE
SHOWERS/STORMS END LATE THIS EVENING...SKIES WILL BEGIN TO CLEAR AS
HIGH PRESSURE BUILDS IN FROM THE NORTHWEST. THE COMBINATION OF AMPLE
LOW LEVEL MOISTURE AND DRIER...MORE STABLE AIR ALOFT WILL CREATE
FAVORABLE CONDITIONS FOR FOG AS SURFACE INVERSIONS DEVELOP OVERNIGHT
INTO WEDNESDAY MORNING. HOWEVER...DRY DOWNSLOPE WESTERLY FLOW AND
WINDS MAINTAINING SPEEDS OF 5-10 KT MAY RESULT IN A STRATUS DECK
RATHER THAN GROUND FOG. WILL RE-EVALUATE THIS POTENTIAL WITH THE 12Z
TAF ISSUANCE.
HIGH PRESSURE PREVAILS WEDNESDAY INTO THURSDAY. A LOW PRESSURE
SYSTEM MOVING ACROSS CENTRAL PENNSYLVANIA ON THURSDAY WILL DRAG A
WEAK FRONT OVER THE AREA THURSDAY NIGHT INTO FRIDAY MORNING.
&&
.MARINE...
SW WINDS TODAY WILL BECOME BREEZY BY THIS AFTERNOON AS A COLD FRONT
APPROACHES THE REGION. EXPECT WINDS TO SHIFT TO THE W THIS EVENING...
BECOMING NW-N BEHIND THE FRONT AS IT TRACKS FROM NORTHWEST TO
SOUTHEAST ACROSS THE WATERS. CAA STILL DOES NOT APPEAR TO BE VERY
STRONG BUT A PROLONGED PERIOD OF NLY WINDS INTO WED HAS PROMPTED
THE ISSUANCE OF SCA FLAGS THROUGH EARLY WED MORNING. WINDS OVER
THE BAY/SOUND SHOULD TOP OUT AROUND 25 KT WITH WAVES OF 2-3 FT AND
UP TO 4 FT AT TIMES. NRN OCEAN WATERS WILL FIRST EXPERIENCE GUSTS
OF 25 KT AND SEAS OF 3-5 FT...WHILE SRN OCEAN WATERS WILL SEE
GUSTS OF 25 KT AFTER MIDNIGHT AND SEAS OF GENERALLY 2-4 FT.
HIGH PRESSURE BUILDS IN FROM THE NORTHWEST ON WED AND THE GRADIENT
RELAXES. WINDS WILL THEN VEER TO THE S-SW LATE WED NIGHT THROUGH FRI
AS A LOW PRESSURE SYSTEM MOVING ACROSS CENTRAL PENNSYLVANIA DRAGS A
WEAK FRONT ACROSS THE WATERS THURSDAY NIGHT INTO FRIDAY MORNING.
SEAS WILL GENERALLY BE 2-3 FT (OCCASIONALLY 4 FT NEAR 20 NM) AND
WAVES 1-2 FT (INCREASING TO 3 FT AT TIMES...ESPECIALLY DURING THE
OVERNIGHT HOURS DUE TO DIURNAL INSTABILITY EFFECTS).
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NCZ012>017-
030>032.
VA...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR VAZ087>097.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 9 AM EDT
WEDNESDAY FOR ANZ638-650-652-654.
SMALL CRAFT ADVISORY FROM 2 AM TO 9 AM EDT WEDNESDAY FOR
ANZ633-656-658.
SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
WEDNESDAY FOR ANZ630>632-634.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAS/MAM
SHORT TERM...MAS/MAM
LONG TERM...ALB
AVIATION...BMD
MARINE...BMD
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1205 PM EDT TUE JUL 24 2012
.SYNOPSIS...
A COLD FRONT, MOVING SOUTHWARD THROUGH THE UPPER OHIO VALLEY, CAN
STILL CAUSE SCATTERED THUNDERSTORMS, WITH GUSTY WIND, HAIL, AND
HEAVY RAIN, INTO EARLY EVENING, MAINLY SOUTH OF THE INTERSTATE
80 CORRIDOR. ANOTHER FRONT WILL BRING SCATTERED THUNDERSTORMS
THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
RECENT RADAR AND SURFACE DATA SHOW ADDITIONAL PREFRONTAL
SCATTERED SHOWERS AND THUNDERSTORMS WILL BE MOVING SOUTHEASTWARD
ACROSS THE UPPER OHIO VALLEY SOUTH OF I-80 INTO EARLY EVENING.
SOME STORMS CAN HAVE GUSTY WIND, HAIL, HEAVY RAIN, AND FREQUENT
LIGHTNING. SPC HAS INDICATED STORMS CAN REACH SEVERE LIMITS.
THUNDERSTORMS CAN BE SCATTERED AS FAR NORTH AS THE NEW
PHILADELPHIA-PITTSBURGH CORRIDOR THIS AFTERNOON. HIGH TEMPERATURES
HAVE BEEN TRIMMED BY 1-2 DEGREES DUE TO EVAPORATIVE-COOLING
EFFECTS OF THIS MORNINGS RAINFALL.
EXPECT POSTFRONTAL NORTHWESTERLY WINDS TO END REMAINING SHOWERS
THIS EVENING, AND PROVIDE LOWER DEW POINTS. WILL CONSIDER LATE
NIGHT FOG PROSPECTS WITH NEXT UPDATE.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
TODAY/S FRONT SHOULD LIFT BACK TO THE NORTH WEDNESDAY AND WEDNESDAY
NIGHT AS A WARM FRONT. STILL UNSURE AS TO JUST HOW PRECIPITATION THE
FRONT WILL GENERATE ON ITS RETURN TRIP. 00Z MODEL RUNS HAVE
ACCELERATED THE WARM FRONT PASSAGE...AND NOW SHOW THAT THE FRONT
WILL LIKELY MOVE THROUGH WEDNESDAY EVENING. THIS TIMING SHOULD LIMIT
DIURNAL ENHANCEMENT OF SHOWERS/STORMS. THE FASTER TIMING WILL ALSO
KEEP WEDNESDAY NIGHT LOWS A BIT HIGHER AS WELL WITH THE REGION
RETURNING TO THE WARM SECTOR MORE QUICKLY.
LOW PRESSURE WILL TRACK FROM LOWER MICHIGAN TOWARDS NEW ENGLAND ON
THURSDAY...DRAGGING A COLD FRONT TO THE SOUTHEAST. WITH THE FRONT
SLIDING THROUGH THE REGION SLOWLY...THIS COULD PROVIDE AN EXTENDED
PERIOD FOR SHOWERS AND STORMS FOR ALL OF THURSDAY AND FRIDAY. ANY
POTENTIAL FOR SEVERE WEATHER ON THURSDAY WILL BE DEPENDENT ON
LOCATION OF THE FRONT. FOR NOW...SPC HAS DEPICTED A BROAD AREA FOR
SEVERE POTENTIAL ON THURSDAY..INCLUDING THE ENTIRE FORECAST AREA.
THURSDAY APPEARS TO BE THE WARMEST DAY WHILE THE REGION IS IN THE
WARM SECTOR...WITH TEMPERATURES AROUND 90. TEMPS SHOULD BE SEASONAL
FOR WEDNESDAY AND FRIDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
LATEST MEDIUM RANGE MODELS STILL DIG A SHORT WAVE TROUGH ACROSS THE
GREAT LAKES REGION FRIDAY AND SLOWLY MOVE THE TROUGH AXIS MOVE EAST
TO THE NEW ENGLAND COAST BY MONDAY.
KEPT SCATTERED SHOWERS AND THUNDERSTORMS IN THE FORECAST FRIDAY
NIGHT AND SATURDAY...WITH DRY WEATHER EXPECTED SUNDAY INTO MONDAY
AS THE UPPER TROUGH MOVES EAST AND A WEAK SURFACE HIGH BRINGS
DRIER AIR IN FROM THE NORTHWEST.
FORECAST TEMPERATURES ARE CLOSE TO HPC GUIDANCE AND NEAR NORMAL
THROUGH THE EXTENDED PERIOD.
&&
.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
PER RECENT SURFACE AND RADAR DATA, COUPLED WITH HRRR MODEL OUTPUT,
MAINTAINED MENTION OF TEMPO MVFR RESTRICTIONS WITH SHOWERS AND
SCATTERED THUNDERSTORMS KZZV-KPIT AND SOUTH. SURFACE WINDS WILL
BECOME NORTHWEST NEAR 10 KTS WITH GUSTS TO 20 KTS. HIGHER GUSTS
POSSIBLE NEAR THUNDERSTORMS.
POSTFRONTAL DRYING WILL PROMOTE VFR STARTING THIS EVENING.
POTENTIAL FOR LATE NIGHT PATCHY FOG MAY PRODUCE RESTRICTIONS, BUT
NOT ENOUGH CONFIDENCE TO MENTION IN TAF.
OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
GEN VFR...BUT WITH PERIODIC CHCS FOR TSRA/ASSOCIATED RESTRICTIONS
ARE EXPECTED FOR THE REMAINDER OF THE WEEK AS A SERIES OF SHRTWVS
TRACK ACRS THE UPR OH VALLEY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
355 PM EDT TUE JUL 24 2012
.SYNOPSIS...
WEAK FRONT SETTLES SOUTH INTO CENTRAL WV AND SOUTHERN OHIO OVERNIGHT
THEN LIFTS BACK NORTH WEDNESDAY AFTERNOON AND EVENING. COLD FRONT
PASSES THURSDAY NIGHT INTO FRIDAY.
&&
.NEAR TERM /UNTIL 3 AM WEDNESDAY MORNING/...
UPDATED FORECAST TO REMOVE THE FLASH FLOOD WATCH AND THE SEVERE
THUNDERSTORM WATCH AS STRONGER STORMS HAVE MOVED EAST AND SOUTH OF
THE AREA. WILL ALSO LOWER POPS CONSIDERABLY NORTH OF THE COMPLEX AND
BETTER TIME THE COMPLEX OUT OF THE AREA.
&&
.SHORT TERM /3 AM WEDNESDAY MORNING THROUGH FRIDAY NIGHT/...
WARM FRONTAL BOUNDARY WILL CONTINUE TO MOVE NORTH THROUGH THE CWA
WEDNESDAY NIGHT...WITH WARM HUMID AIR SURGING BACK NORTH AGAIN AS IT
DOES SO. THURSDAY LOOKS TO BE ANOTHER HOT AND HUMID DAY...WITH
RISING HEIGHTS AHEAD OF APPROACHING UPPER TROUGH AND MAX
TEMPERATURES IN THE LOWER TO MID 90S...AND DEW POINTS PROGGED TO
REMAIN IN THE 70S...MAY NEED TO CONSIDER A HEAT ADVISORY FOR
THURSDAY...PARTICULARLY ACROSS NORTHERN HALF OF CWA. WILL HIGHLIGHT
THIS IN THE HWO FOR NOW.
COLD FRONT WILL APPROACH CWA THURSDAY NIGHT/FRIDAY. OUT AHEAD OF THE
FRONT...PLENTY OF WARM...UNSTABLE AIR...WITH MODELS SUGGESTING CAPE
OF OVER 2000 J/KG...20-30KT 0-6KM SHEAR...AND 30-40 KT LLJ ACROSS
THE CWA. A SLIGHT RISK HAS ALREADY BEEN ISSUED BY SPC FOR THURSDAY
ACROSS NORTHERN ZONES. IN ADDITION...PW VALUES WILL ONCE AGAIN BE
BACK UP TO AROUND 2 INCHES...HOWEVER...WITH THE OVERALL FAST FLOW
ALOFT EXPECTED...THIS SHOULD HELP TO LIMIT ANY MAJOR WATER
ISSUES...ALTHOUGH HEAVY DOWNPOURS ARE ONCE AGAIN EXPECTED.
USED A BLEND OF THE MET/MAV FOR MAX TEMPERATURES IN THE SHORT TERM.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
ISOLD SHOWER/STORM ACTIVITY WILL PERSIST ACROSS THE CWA ON SATURDAY
AS THE REGION REMAINS UNDER THE INFLUENCE OF AN UPPER LEVEL TROUGH.
HOWEVER...HIGH PRESSURE WILL GRADUALLY BEGIN TO BUILD INTO THE
REGION...PUSHING DRIER AIR INTO THE CWA. THIS WILL SET THE STAGE FOR
A BRIEF DRY PERIOD SUNDAY INTO EARLY NEXT WEEK. REMAINDER OF THE
LONG TERM LOOKS UNSETTLED.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
HEAVIEST CONVECTION WILL BE CROSSING THE MOUNTAINOUS COUNTIES 18Z TO
21Z. LINGERING LIGHTER SHOWERS FURTHER WEST AND NORTH. STILL
QUESTIONABLE ON ANY REDEVELOPMENT OF STORMS...SAY OUT TOWARD SOUTHERN
INDIANA FOR LATE THIS AFTERNOON OR EARLY THIS EVENING. RAP SHOWS
ANOTHER VORT MAX AT 500 MB DROPPING THROUGH SE THRU OHIO INTO WV BY
03Z. SO WILL HOLD ONTO SOME CHANCE POPS IN THE SOUTH AND WEST.
SOME 5 MILES IN HAZE MAY LINGER AFTER THE CONVECTION FOR LATE
AFTERNOON THROUGH SUNSET.
HAVE STRATUS AOB 1 THSD FT BKN AND VSBY AOB 3 MILES IN PATCHES OF FOG
FORMING 03Z TO 06Z...MAINLY EKN-CRW-HTS ON SOUTH INTO THE SOUTHERN
WV COAL FIELDS.
HAVE THE CLOUDS LIFTING 12Z TO 15Z...BECOMING MOSTLY 2 TO 4 THSD FT
BKN BY 18Z. DID NOT INCLUDE ANY CONVECTION IN TAFS BEFORE 18Z...BUT
HAVE CHANCE POPS ACROSS TRI STATE INTO SOUTHERN WV. SOME CONVECTION
NEAR WEAK FRONT MAY REACH NORTH CENTRAL WV TOWARD 18Z WED.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY...
FORECAST CONFIDENCE: LOW TO MEDIUM.
ALTERNATE SCENARIOS: FOG AND STRATUS DEVELOPMENT OVERNIGHT IS
MAY VARY IN COVERAGE AND INTENSITY..MAINLY FOR THE 06Z TO 12Z
WEDNESDAY PERIOD.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H M M M M M M L
HTS CONSISTENCY M M M M M H H H H M M M
BKW CONSISTENCY H H H H H H H H H M M H
EKN CONSISTENCY M M M M M H H H M M M M
PKB CONSISTENCY H H H M H H H H H M M M
CKB CONSISTENCY H H H H H H M H M M M M
AFTER 18Z WEDNESDAY...
IFR POSSIBLE IN CONVECTION THURSDAY AFTERNOON AND THURSDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JMV/26
NEAR TERM...RPY
SHORT TERM...SL
LONG TERM...SL
AVIATION...
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
241 PM EDT TUE JUL 24 2012
.SYNOPSIS...
WEAK FRONT SETTLES SOUTH INTO CENTRAL WV AND SOUTHERN OHIO OVERNIGHT
THEN LIFTS BACK NORTH WEDNESDAY AFTERNOON AND EVENING. COLD FRONT
PASSES THURSDAY NIGHT INTO FRIDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
COLD FRONT STILL NORTH OF INTERSTATE 70 IN OHIO AT 18Z. NO SIGNS OF
ANY REDEVELOPMENT IN SOUTHERN INDIANA AT 18Z. MEANWHILE COVERAGE
INCREASING IN NORTH CENTRAL WV. A REDEFINING STATEMENT ADDED A
FEW COUNTIES TOWARD EKN INTO WATCH 509 PER COORDINATION WITH SPC.
ALSO STARTED TO DROP COUNTIES FURTHER WEST INCLUDING SOUTHEAST OHIO.
THE HIGHER POPS QUICKLY DROP FROM NW TO SE LATE THIS AFTERNOON. WILL
LEAVE SOME HAZE IN ITS WAKE. NO MAJOR CHANGES IN POP
FIELD...LEAVING SOME 20 TO 30 PERCENT POPS LATE TONIGHT FROM HTS-CRW
AND BKW. SOME LOWER CLOUDS COULD FORM OVERNIGHT FROM EKN DOWN THRU
CRW AND POINTS SOUTH...SO LEFT MINIMUM TEMPERATURE TOWARD THE WARMER
NAM MOS.
WITH THE WEAK SUMMER FRONT STILL IN THE VICINITY...WILL NOT BUY GFS
BONE DRY POPS YET. HAVE SOME CHANCE POPS CREEPING BACK NORTH
WEDNESDAY AFTERNOON.
MAY BE ABLE TO DROP THE FLASH FLOOD WATCH EARLY...BUT NO REASON TO
JUMP ON THAT AT THIS TIME...ESPECIALLY WITH THE NEW CONVECTION
HEADING INTO THE CENTRAL MOUNTAINS.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
WARM FRONTAL BOUNDARY WILL CONTINUE TO MOVE NORTH THROUGH THE CWA
WEDNESDAY NIGHT...WITH WARM HUMID AIR SURGING BACK NORTH AGAIN AS IT
DOES SO. THURSDAY LOOKS TO BE ANOTHER HOT AND HUMID DAY...WITH
RISING HEIGHTS AHEAD OF APPROACHING UPPER TROUGH AND MAX
TEMPERATURES IN THE LOWER TO MID 90S...AND DEW POINTS PROGGED TO
REMAIN IN THE 70S...MAY NEED TO CONSIDER A HEAT ADVISORY FOR
THURSDAY...PARTICULARLY ACROSS NORTHERN HALF OF CWA. WILL HIGHLIGHT
THIS IN THE HWO FOR NOW.
COLD FRONT WILL APPROACH CWA THURSDAY NIGHT/FRIDAY. OUT AHEAD OF THE
FRONT...PLENTY OF WARM...UNSTABLE AIR...WITH MODELS SUGGESTING CAPE
OF OVER 2000 J/KG...20-30KT 0-6KM SHEAR...AND 30-40 KT LLJ ACROSS
THE CWA. A SLIGHT RISK HAS ALREADY BEEN ISSUED BY SPC FOR THURSDAY
ACROSS NORTHERN ZONES. IN ADDITION...PW VALUES WILL ONCE AGAIN BE
BACK UP TO AROUND 2 INCHES...HOWEVER...WITH THE OVERALL FAST FLOW
ALOFT EXPECTED...THIS SHOULD HELP TO LIMIT ANY MAJOR WATER
ISSUES...ALTHOUGH HEAVY DOWNPOURS ARE ONCE AGAIN EXPECTED.
USED A BLEND OF THE MET/MAV FOR MAX TEMPERATURES IN THE SHORT TERM.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
ISOLD SHOWER/STORM ACTIVITY WILL PERSIST ACROSS THE CWA ON SATURDAY
AS THE REGION REMAINS UNDER THE INFLUENCE OF AN UPPER LEVEL TROUGH.
HOWEVER...HIGH PRESSURE WILL GRADUALLY BEGIN TO BUILD INTO THE
REGION...PUSHING DRIER AIR INTO THE CWA. THIS WILL SET THE STAGE FOR
A BRIEF DRY PERIOD SUNDAY INTO EARLY NEXT WEEK. REMAINDER OF THE
LONG TERM LOOKS UNSETTLED.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
HEAVIEST CONVECTION WILL BE CROSSING THE MOUNTAINOUS COUNTIES 18Z TO
21Z. LINGERING LIGHTER SHOWERS FURTHER WEST AND NORTH. STILL
QUESTIONABLE ON ANY REDEVELOPMENT OF STORMS...SAY OUT TOWARD SOUTHERN
INDIANA FOR LATE THIS AFTERNOON OR EARLY THIS EVENING. RAP SHOWS
ANOTHER VORT MAX AT 500 MB DROPPING THROUGH SE THRU OHIO INTO WV BY
03Z. SO WILL HOLD ONTO SOME CHANCE POPS IN THE SOUTH AND WEST.
SOME 5 MILES IN HAZE MAY LINGER AFTER THE CONVECTION FOR LATE
AFTERNOON THROUGH SUNSET.
HAVE STRATUS AOB 1 THSD FT BKN AND VSBY AOB 3 MILES IN PATCHES OF FOG
FORMING 03Z TO 06Z...MAINLY EKN-CRW-HTS ON SOUTH INTO THE SOUTHERN
WV COAL FIELDS.
HAVE THE CLOUDS LIFTING 12Z TO 15Z...BECOMING MOSTLY 2 TO 4 THSD FT
BKN BY 18Z. DID NOT INCLUDE ANY CONVECTION IN TAFS BEFORE 18Z...BUT
HAVE CHANCE POPS ACROSS TRI STATE INTO SOUTHERN WV. SOME CONVECTION
NEAR WEAK FRONT MAY REACH NORTH CENTRAL WV TOWARD 18Z WED.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY...
FORECAST CONFIDENCE: LOW TO MEDIUM.
ALTERNATE SCENARIOS: FOG AND STRATUS DEVELOPMENT OVERNIGHT IS
MAY VARY IN COVERAGE AND INTENSITY..MAINLY FOR THE 06Z TO 12Z
WEDNESDAY PERIOD.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H M M M M M M L
HTS CONSISTENCY M M M M M H H H H M M M
BKW CONSISTENCY H H H H H H H H H M M H
EKN CONSISTENCY M M M M M H H H M M M M
PKB CONSISTENCY H H H M H H H H H M M M
CKB CONSISTENCY H H H H H H M H M M M M
AFTER 18Z WEDNESDAY...
IFR POSSIBLE IN CONVECTION THURSDAY AFTERNOON AND THURSDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR WVZ005>008-
013>016-018-024>030-033>040-046-047.
OH...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR OHZ083-086-
087.
KY...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR KYZ101>103-
105.
VA...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR VAZ003-004.
&&
$$
SYNOPSIS...JMV/26
NEAR TERM...KTB
SHORT TERM...SL
LONG TERM...SL
AVIATION...KTB
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
219 PM EDT TUE JUL 24 2012
.SYNOPSIS...
WEAK FRONT SETTLES SOUTH INTO CENTRAL WV AND SOUTHERN OHIO OVERNIGHT
THEN LIFTS BACK NORTH WEDNESDAY AFTERNOON AND EVENING. COLD FRONT
PASSES THURSDAY NIGHT INTO FRIDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
COLD FRONT STILL NORTH OF INTERSTATE 70 IN OHIO AT 18Z. NO SIGNS OF
ANY REDEVELOPMENT IN SOUTHERN INDIANA AT 18Z. MEANWHILE COVERAGE
INCREASING IN NORTH CENTRAL WV. A REDEFINING STATEMENT ADDED A
FEW COUNTIES TOWARD EKN INTO WATCH 509 PER COORDINATION WITH SPC.
ALSO STARTED TO DROP COUNTIES FURTHER WEST INCLUDING SOUTHEAST OHIO.
THE HIGHER POPS QUICKLY DROP FROM NW TO SE LATE THIS AFTERNOON. WILL
LEAVE SOME HAZE IN ITS WAKE. NO MAJOR CHANGES IN POP
FIELD...LEAVING SOME 20 TO 30 PERCENT POPS LATE TONIGHT FROM HTS-CRW
AND BKW. SOME LOWER CLOUDS COULD FORM OVERNIGHT FROM EKN DOWN THRU
CRW AND POINTS SOUTH...SO LEFT MINIMUM TEMPERATURE TOWARD THE WARMER
NAM MOS.
WITH THE WEAK SUMMER FRONT STILL IN THE VICINITY...WILL NOT BUY GFS
BONE DRY POPS YET. HAVE SOME CHANCE POPS CREEPING BACK NORTH
WEDNESDAY AFTERNOON.
MAY BE ABLE TO DROP THE FLASH FLOOD WATCH EARLY...BUT NO REASON TO
JUMP ON THAT AT THIS TIME...ESPECIALLY WITH THE NEW CONVECTION
HEADING INTO THE CENTRAL MOUNTAINS.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
WARM FRONTAL BOUNDARY WILL CONTINUE TO MOVE NORTH THROUGH THE CWA
WEDNESDAY NIGHT...WITH WARM HUMID AIR SURGING BACK NORTH AGAIN AS IT
DOES SO. THURSDAY LOOKS TO BE ANOTHER HOT AND HUMID DAY...WITH
RISING HEIGHTS AHEAD OF APPROACHING UPPER TROUGH AND MAX
TEMPERATURES IN THE LOWER TO MID 90S...AND DEW POINTS PROGGED TO
REMAIN IN THE 70S...MAY NEED TO CONSIDER A HEAT ADVISORY FOR
THURSDAY...PARTICULARLY ACROSS NORTHERN HALF OF CWA. WILL HIGHLIGHT
THIS IN THE HWO FOR NOW.
COLD FRONT WILL APPROACH CWA THURSDAY NIGHT/FRIDAY. OUT AHEAD OF THE
FRONT...PLENTY OF WARM...UNSTABLE AIR...WITH MODELS SUGGESTING CAPE
OF OVER 2000 J/KG...20-30KT 0-6KM SHEAR...AND 30-40 KT LLJ ACROSS
THE CWA. A SLIGHT RISK HAS ALREADY BEEN ISSUED BY SPC FOR THURSDAY
ACROSS NORTHERN ZONES. IN ADDITION...PW VALUES WILL ONCE AGAIN BE
BACK UP TO AROUND 2 INCHES...HOWEVER...WITH THE OVERALL FAST FLOW
ALOFT EXPECTED...THIS SHOULD HELP TO LIMIT ANY MAJOR WATER
ISSUES...ALTHOUGH HEAVY DOWNPOURS ARE ONCE AGAIN EXPECTED.
USED A BLEND OF THE MET/MAV FOR MAX TEMPERATURES IN THE SHORT TERM.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
ISOLD SHOWER/STORM ACTIVITY WILL PERSIST ACROSS THE CWA ON SATURDAY
AS THE REGION REMAINS UNDER THE INFLUENCE OF AN UPPER LEVEL TROUGH.
HOWEVER...HIGH PRESSURE WILL GRADUALLY BEGIN TO BUILD INTO THE
REGION...PUSHING DRIER AIR INTO THE CWA. THIS WILL SET THE STAGE FOR
A BRIEF DRY PERIOD SUNDAY INTO EARLY NEXT WEEK. REMAINDER OF THE
LONG TERM LOOKS UNSETTLED.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
HEAVIEST CONVECTION WILL BE CROSSING THE MOUNTAINOUS COUNTIES 18Z TO
21Z. LINGERING LIGHTER SHOWERS FURTHER WEST AND NORTH. STILL
QUESTIONABLE ON ANY REDEVELOPMENT OF STORMS...SAY OUT TOWARD SOUTHERN
INDIANA FOR LATE THIS AFTERNOON OR EARLY THIS EVENING. RAP SHOWS
ANOTHER VORT MAX AT 500 MB DROPPING THROUGH SE THRU OHIO INTO WV BY
03Z. SO WILL HOLD ONTO SOME CHANCE POPS IN THE SOUTH AND WEST.
SOME 5 MILES IN HAZE MAY LINGER AFTER THE CONVECTION FOR LATE
AFTERNOON THROUGH SUNSET.
HAVE STRATUS AOB 1 THSD FT BKN AND VSBY AOB 3 MILES IN PATCHES OF FOG
FORMING 03Z TO 06Z...MAINLY EKN-CRW-HTS ON SOUTH INTO THE SOUTHERN
WV COAL FIELDS.
HAVE THE CLOUDS LIFTING 12Z TO 15Z...BECOMING MOSTLY 2 TO 4 THSD FT
BKN BY 18Z. DID NOT INCLUDE ANY CONVECTION IN TAFS BEFORE 18Z...BUT
HAVE CHANCE POPS ACROSS TRI STATE INTO SOUTHERN WV. SOME CONVECTION
NEAR WEAK FRONT MAY REACH NORTH CENTRAL WV TOWARD 18Z WED.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY...
FORECAST CONFIDENCE: LOW TO MEDIUM.
ALTERNATE SCENARIOS: FOG AND STRATUS DEVELOPMENT OVERNIGHT IS
MAY VARY IN COVERAGE AND INTENSITY..MAINLY FOR THE 06Z TO 12Z
WEDNESDAY PERIOD.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H M M M M M M L
HTS CONSISTENCY M M M M M H H H H M M M
BKW CONSISTENCY H H H H H H H H H M M H
EKN CONSISTENCY M M M M M H H H M M M M
PKB CONSISTENCY H H H M H H H H H M M M
CKB CONSISTENCY H H H H H H M H M M M M
AFTER 18Z WEDNESDAY...
IFR POSSIBLE IN CONVECTION THURSDAY AFTERNOON AND THURSDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR WVZ005>008-
013>016-018-024>030-033>040-046-047.
OH...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR OHZ083-086-
087.
KY...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR KYZ101>103-
105.
VA...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR VAZ003-004.
&&
$$
SYNOPSIS...JMV/26
NEAR TERM...KTB
SHORT TERM...SL
LONG TERM...SL
AVIATION...KTB
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
251 PM EDT TUE JUL 24 2012
.SYNOPSIS...
A WEAK UPPER LEVEL RIDGE WILL BUILD ACROSS THE REGION TONIGHT AND
PERSIST THROUGH THURSDAY. A COLD FRONT IS THEN EXPECTED TO MOVE
ACROSS THE CAROLINAS AND NORTHEAST GEORGIA ON LATE FRIDAY INTO
SATURDAY. ANOTHER RIDGE OF HIGH PRESSURE BUILDS BACK IN SUN AND
REMAINS THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 250 PM...AN MCS WHICH ORIGINATED OVER THE DAKOTAS LAST NIGHT
HAS CONTINUED TO PROGRESS TO THE SE AND WAS LOCATED OVER ERN KY AND
WRN WV. THE LATEST RAP ANALYSIS SHOWS THAT THE SQUALL LINE IS
EMBEDDED IN AN AREA OF 40-50 KT 0-3KM SHEAR. THIS SHOULD PROVIDE
AMPLE SUPPORT FOR THE MCS TO CONTINUE TO MOVE SE DURING THE REST OF
THE AFTN. THE EASTERN END OF THE LINE IS LOCATED IN AN AREA OF
FAIRLY STABLE AIR AND HAS BEEN DECAYING OF LATE. THE WESTERN
END...HOWEVER...IS IN MUCH MORE UNSTABLE AIR AND CONTINUES TO
EXHIBIT VIGOROUS CONVECTIVE DEVELOPMENT. BASED ON IT/S CURRENT
MOVEMENT...IT SHOULD ENTER THE NC MTNS A LITTLE BEFORE 5 PM. FARTHER
TO THE EAST CONVECTION HAS NOT MAINTAINED AS MUCH ORGANIZATION AS I
EARLIER THROUGH IT WOULD. HOWEVER...VERY INTENSE CELLS HAVE RECENTLY
DEVELOPED JUST EAST OF THE FA IN THE NC PIEDMONT. SPC HAS PLACED
MUCH OF THE NC FOOTHILLS AND PIEDMONT AND THE NE UPSTATE UNDER A
SEVERE TSTM WATCH UNTIL 10 PM AND THERE IS A GOOD CHANCE THAT
DISCRETE SEVERE STORMS WILL BEGIN TO DEVELOP BACK ACROSS OUR
FORECAST AREA OVER THE NEXT HOUR OR TWO. ALL TOLD...LIKELY TO
CATEGORICAL POPS STILL LOOK GOOD THE REST OF THE AFTN AND
EVENING...BUT THE TIMING WAS A LITTLE TOO AGGRESSIVE OVER WESTERN NC.
LATER TONIGHT A WEAK SFC BNDRY WILL MOVE IN FROM THE NORTHEAST. OR
IT MAY SIMPLY BE A MODEL REFLECTION OF EXTENSIVE OUTFLOW BNDRYS.
EITHER WAY...THE NAM KEEPS QUITE A BIT OF CAPE OVER THE REGION
TONIGHT...AND SHRA/TSTMS MAY PERSIST IN SPOTS MUCH OF THE NIGHT. THE
BEST CHANCES WILL PROBABLY BE ALONG THE TN LINE WHERE NW FLOW WILL
GIVE AN OROGRAPHIC BOOST TO CONVECTION. IN THESE AREAS I/VE
MAINTAINED CHANCE POPS THROUGH THE NIGHT...THOUGH ELSEWHERE I TAKE
THEM INTO THE SLIGHT CHANCE RANGE AFTER THE INITIAL ROUNDS OF
CONVECTION.
THE NAM POOLS HIGH DEWPOINTS AND QUITE A BIT OF CAPE OVER THE FA ON
WEDNESDAY. SPC HAS PLACED THE REGION UNDER A 5 PERCENT SEVERE RISK.
THE DEEP LAYER RIDGE WILL TRY TO NOSE BACK INTO THE FA...BUT THE
AMOUNT OF INSTABILITY AND WEAK SFC CONVERGENCE SHOULD SUPPORT GOOD
CONVECTIVE COVERAGE OVER THE WESTERN CAROLINAS AND NE GA DURING THE
AFTN HOURS. SOME OF THESE WILL PROBABLY REACH PULSE SEVERE LIMITS
WITH SMALL AREAS OF WIND DAMAGE AND LARGE HAIL. MAX TEMPS WILL RUN A
COUPLE CATEGORIES ABOVE NORMAL.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
AS OF 220 PM EDT TUESDAY...SHORT RANGE MODELS INDICATE THAT THE MID
LEVEL RIDGE WILL BUILD OVER THE REGION ON THURSDAY. H85 TEMPS WITHIN
THE LEE OF THE MOUNTAINS INCREASE TO AROUND 24C DURING THE
AFTERNOON. A WEAK SUBSIDENCE IS EXPECTED TO DEVELOP BETWEEN H7 TO
H8...YIELDING AN SHALLOW LAYER OF CIN BETWEEN 10 TO 30 J/KG. IT
APPEARS THAT WEAK LEE TROF MAY DEEPEN SLIGHTLY WITH WEST H85
FLOW...BUT SFC MOISTURE CONVERGENCE SHOULD REMAIN WEAK. COVERAGE OF
DIURNAL CONVECTION SHOULD BE LIMITED BY AFTERNOON MIXING OF SFC
DEWPOINTS AND PERSISTENT WEAK CAPPING. I WILL FORECAST MID AFTERNOON
INITIATION ACROSS THE RIDGES...WITH CHC POPS INTO THE EARLY EVENING.
COVERAGE EAST OF THE MTNS SHOULD REMAIN LIMITED TO A SCHC. THE MAIN
CONCERN ON THURSDAY WILL BE THE HOT AFTERNOON TEMPERATURES. USING A
BLEND OF MOS...HIGH TEMPERATURES ARE FORECAST TO RANGE FROM AROUND
90 WITHIN THE MTN VALLEYS TO U90S EAST...3 TO 5 DEGREES LOWER THAN
RECORDS. HOWEVER...EVEN WITH MIXING DEWPOINTS...HEAT INDEX VALUES
NEAR THE CLT METRO MAY MEET HEAT ADVISORY CRITERIA.
ON FRIDAY...A WEAK COLD FRONT IS EXPECTED TO MOVE ACROSS THE
SOUTHERN APPALACHIANS DURING THE AFTERNOON. THE ENVIRONMENT AHEAD OF
THE FRONT IS EXPECTED TO DEVELOP CAPE VALUES BETWEEN 1500 TO 2000
J/KG WITH LITTLE TO NO CIN. IN ADDITION...UPPER DIVERGENCE MAY
DEVELOP OVER THE REGION AS THE CORE OF A H3 JET PUSHES ACROSS PA.
GIVEN THE APPROACH OF THE SFC FRONT...WIDESPREAD INSTABILITY...AND
UPPER SUPPORT...I WILL FORECAST LIKELY POPS ACROSS THE MTNS AND 30
TO 40 POPS EAST. SEVERE MULTICELL THUNDERSTORMS MAY DEVELOP ALONG
AND AHEAD OF THE FRONT.
HEAT WILL REMAIN A CONCERN ACROSS THE PIEDMONT AS DEWPOINTS RECOVER
TO THE U60S AND HIGHS ONCE AGAIN REACH INTO THE U90S. HEAT INDEX
VALUES ALONG AND EAST OF I-85 MAY REACH HEAT ADVISORY CRITERIA.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 2 PM EDT TUESDAY...THE LATEST MEDIUM RANGE MODELS CONTINUE TO
INDICATE THAT A COLD FRONT WILL MOVE ACROSS THE AREA ON LATE FRI/SAT
AS AN UPPER TROF DEEPENS OVER THE EAST COAST. THE FRONT IS EXPECTED
TO STALL OVER SOUTH OF THE AREA SUN AND DISSIPATES MON AS A RIDGE
BUILDS IN FROM THE SE. THE STRONGEST UPPER FORCING WILL REMAIN NORTH
OF THE AREA...HOWEVER GOOD OVERALL DYNAMICAL LIFT AND H3 DIV ALONG
WITH PLENTY OF LLVL INSTABILITY WILL BE AVAILABLE FOR SCATTERED
DIURNAL TSTMS EACH DAY THROUGH THE PERIOD. POPS WERE MAINTAINED AT
NEAR CLIMO...HOWEVER IF THIS PATTERN AND S/W TIMING PERSISTS OVER
THE NEXT COUPLE MODEL RUNS...AN INCREASE IN POPS WILL BE WARRANTED
FOR FRI/SAT. SUN LOOKS TO BE THE DRIEST DAY WITH FAIRLY STRONG HIGH
PRESSURE BUILDING IN...YET THE FRONT WILL REMAIN JUST TO THE
SOUTH...SO SLIGHT CHANCE POPS WERE MENTIONED THROUGH THE DAY. MON
WILL BE ACTIVE AGAIN AS ANOTHER SHOT OF UPPER ENERGY ROUNDS THE WRN
RIDGE AND TRAVERSES THE REGION. TEMPERATURES WILL BE NEAR...OR A
COUPLE DEGREES ABOVE NORMAL FRI/SAT. WITH NW/LY FLOW SETTING UP
SUN...EXPECT A COUPLE DEGREES COOLER IN THE MTNS SUN/MON. YET...A
GOOD DOWNSLOPE WARMING COMPONENT WILL ENABLE MAXES RIGHT AROUND
NORMAL OVER THE LOWER PIEDMONT.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
AT KCLT...HAVE HELD ON TO TEMPO GROUP FOR CONVECTION FROM 20-22 UTC
THIS AFTN. TSTMS ARE MOVING INTO THE NC MTNS ATTM. HOWEVER...THEY
HAVE LOST SOME OF THEIR ORGANIZATION. I STILL THINK THEY WILL
ORGANIZE AS THEY EMERGE INTO THE FOOTHILLS AND CONFIDENCE IS STILL
GOOD IN A SQUALL LINE LATER IN THE AFTN. WINDS WILL PROBABLY AVERAGE
FROM THE WNW THE REST OF THE AFTN...THOUGH THEY MAY BACK TO THE WSW
AT TIMES. THEY WILL TURN MORE OUT OF THE NORTH BEHIND A WEAK COLD
FRONT LATE TONIGHT. WHILE NOTHING HAS BEEN CARRIED IN THE
TAF...THERE ARE INDICATIONS THAT SHRA/TSTM ACTIVITY COULD BE IN THE
VCNTY MUCH OF THE NIGHT.
ELSEWHERE...SCT TSTMS WILL CONTINUE TO DEVELOP ACROSS THE REGION
THIS AFTN. A STRONG SQUALL LINE IS EXPECTED TO DROP ACROSS THE
REGION THIS EVENING. FOR NOW I/M JUST GOING TO CARRY VCTS FOR
SEVERAL HOURS...BUT AS THE LINE GETS CLOSER WE SHOULD BE ABLE TO ADD
A PERIOD OF TEMPO OR PREVAILING THUNDER. A WEAK COLD FRONT WILL
STALL OVER THE REGION LATE TONIGHT...AND THIS MAY ALLOW SCT
SHRA/TSTMS TO LAST INTO THE MORNING HOURS...THOUGH FOR NOW THAT
HASN/T BEEN CARRIED IN THE TAF. WINDS WILL BE WSW TO W OVER THE
UPSTATE AND NW OVER WRN NC. WINDS LATER TONIGHT WILL BECOME LIGHT OR
SHIFT TO LIGHT OUT OF THE NORTH BEHIND THE FRONT AND THUNDERSTORM
COMPLEXES.
OUTLOOK...EXPECT SOLID CHC CONVECTION WED AFTERNOON AND EVENING.
BEST CHC OF OVERNIGHT RESTRICTIONS WILL BE IN AREAS THAT SEE LOCALLY
HEAVY RAIN. A COLD FRONT MAY BRING MORE WIDESPREAD CONVECTION FRI
AND FRI NIGHT.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JPT
NEAR TERM...MCAVOY
SHORT TERM...NED
LONG TERM...JOH
AVIATION...MCAVOY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
157 PM EDT TUE JUL 24 2012
.SYNOPSIS...
A WEAK UPPER LEVEL RIDGE WILL BUILD ACROSS THE REGION TONIGHT AND
PERSIST THROUGH THURSDAY. A COLD FRONT IS THEN EXPECTED TO MOVE
ACROSS THE CAROLINAS AND NORTHEAST GEORGIA ON LATE FRIDAY INTO
SATURDAY. ANOTHER RIDGE OF HIGH PRESSURE BUILDS BACK IN SUN AND
REMAINS THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 155 PM EDT...CONVECTION IS STARTING TO DEVELOP ACROSS THE
MOUNTAINS AND NORTH OF I-40. THIS IS IN LINE WITH THE GRIDS AND ONLY
MINOR TWEAKS HAVE BEEN MADE TO THE FORECAST OVER THE NEXT FEW HOURS.
AS OF 1105 AM EDT...THE ATMOSPHERE IS BECOMING VERY UNSTABLE ALREADY
THIS MORNING AS MOST OF THE FA IS EXPERIENCING FULL SUN. CONVECTION
IS DEVELOPING UPSTREAM OF THE FA OVER ERN KY AND WV. A LONG LIVED
MCS IS MOVING SE AT OVER 50 KTS ACROSS CENTRAL IN AND WRN OH ATTM.
I/M NOT SURE IF THIS FEATURE WILL HOLD TOGETHER AND AFFECT OUR NRN
ZONES STARTING AROUND 20 UTC...OR IF THE LEAD CONVECTION WILL
DEVELOP IT/S OWN COLD POOL AND BECOME AN MCS. HOWEVER...I/M
CONFIDENT THAT ONE OF THESE FEATURES WILL AFFECT THE FA STARTING
BETWEEN ABOUT 2 AND 3 PM. THE WRF-ARW DROPS A WELL FORMED MCS ACROSS
MOST OF THE FORECAST AREA BETWEEN 19-22 UTC. I/VE USED THIS TIMING
TO ADJUST POPS UP INTO THE CATEGORICAL RANGE ALONG THE PROBABLE MCS
PATH LATER IN THE AFTN. THE RAP 0-3 KM BULK SHEAR IS ALSO SUPPORTIVE
OF THIS AS IT INCREASES TO OVER 30 KTS OVER THE NC ZONES AND THE ERN
PART OF THE UPSTATE BY LATE AFTN. I/VE ADDED DAMAGING WIND WORDING
TO THE ZONES IN THESE AREAS AND THE HWO WILL BE PUNCHED UP AS WELL.
ALL OF THIS MATCHES WITH SPC/S 30 PERCENT DAMAGING WIND PROBS FOR
THE FORECAST AREA NORTH AND EAST OF A GREENVILLE TO ASHEVILLE LINE
FOR LATER TODAY.
AS OF 640 AM...NOT MUCH IN THE WAY OF FOG THIS MRNG SO REDUCED
MENTION MOST AREAS. TEMPS WERE TWEAKED WITH LATEST TRENDS...
OTHERWISE FCST IN GOOD SHAPE FOR THIS UPDATE.
STRONGER FLOW ALOFT...INCLUDING A SERIES OF EMBEDDED SHORTWAVES...
COMBINED WITH GOOD INSTABILITY AND STRONG INSOLATION...IS EXPECTED
TO AID THE DEVELOPMENT OF SHWRS AND TSTMS ACROSS THE AREA LATER
TODAY. BETTER SHEAR WILL INCREASE THE CHC OF SEVERE STORMS ACROSS
THE REGION AND SPC HAS PUT THE ENTIRE CWA IN A SLIGHT RISK AREA FOR
SVR STORMS TODAY. THE MAIN CONCERN WILL BE STRAIGHT-LINE WIND DAMAGE
BUT LARGE HAIL AND EVEN AN ISOLD TORNADO WILL ALSO BE PSBL THIS AFTN
AND EVE. COULD ALSO SEE AN MCS DEVELOP UPSTREAM AND DRIFT INTO THE
AREA THIS EVE. ABOVE AVG HIGHS WILL REACH INTO THE MID 90S ACROSS
THE PIEDMONT WITH A FEW UPPER 90S IN THE S ZONES. LOWER MTN VLYS
WILL WARM INTO THE MID-UPPER 80S. CONVECTION SHOULD TAPER OFF LATE
THIS EVE BUT A SLIGHT CHC WILL LINGER OVERNIGHT ACROSS THE MTNS AS
ANOTHER WEAK SHORTWAVE APPROACHES FROM THE NW. LOWS TONIGHT SHOULD
BE A COUPLE DEG ABOVE AVG.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 130 AM EDT TUESDAY...THE SHORT TERM FCST PICKS UP AT 12Z ON
WEDNESDAY WITH AN UPPER RIDGE CENTERED OVER MISSISSIPPI/ALABAMA WITH
NW FLOW ACROSS THE SOUTHERN APPALACHIAN REGION. OVER THE NEXT 24 TO
36 HRS...THE RIDGE FLATTENS A FAIR AMOUNT AS A POTENT LOOKING
SHORTWAVE...THAT IS EMBEDDED WITHIN A BROADER H5 TROF...BEGINS TO DIVE
DOWN FROM THE GREAT LAKES BY THE END OF THE PERIOD AT 12Z ON FRIDAY.
ON WEDNESDAY...A BACKDOOR COLD FRONT WILL MOVE INTO THE CENTRAL
CAROLINAS EARLY IN THE MORNING BRINGING A DECENT SURGE OF LOW TO MID
LVL MOISTURE. FORECAST SOUNDINGS CONTINUE TO DISPLAY 0 TO 6KM BULK
SHEAR VALUES ON THE ORDER OF 20 TO 30KTS OVER THE AREA WITH SFC
BASED CAPE ON THE ORDER OF 500 TO 1000 J/KG. AN MCS COULD DEVELOP TO
OUR NW AND TRACK OVER THE CAROLINAS DURING THE MORNING...WITH
REMNANT CONVECTION MOVING ACROSS THE WESTERN CAROLINAS AND NORTHEAST
GEORGIA DURING THE DAY/EVENING. SOME ORGANIZED CELLS COULD FORM THRU
THE DAY WITH SHEAR VALUES STAYING UP IN THE 20KT RANGE AND HIGH
TEMPS ABOUT A CATEGORY ABOVE NORMAL. THINGS SHOULD EVENTUALLY SETTLE
DOWN OVERNIGHT AS THE LOW LVLS COOL.
ON THURSDAY...BULK SHEAR SHOULD WEAKEN ACROSS THE REGION AS THE
UPPER FLOW BECOMES MORE WESTERLY AND HEIGHTS RISE SLIGHTLY. AT THE
SFC...A LEE TROF WILL LIKELY REMAIN ACROSS THE FCST AREA WITH WEAK
DOWNSLOPE FLOW AND DEEPER MIXING. THIS SHOULD BRING DOWN LOW LVL
DEWPTS MAKING ANY WIDESPREAD TSRA LESS LIKELY. I REDUCED POPS
OVERALL FROM THE PREVIOUS FCST AND ONLY HAVE A SOLID CHANCE OVER THE
HIGHER TERRAIN WITH SLIGHT CHANCE ELSEWHERE. HIGH TEMPERATURES
SHOULD APPROACH 90 DEGREES ACROSS THE MTN VALLEYS WITH MID TO UPPER
90S ACROSS THE LOWER ELEVATIONS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 2 PM EDT TUESDAY...THE LATEST MEDIUM RANGE MODELS CONTINUE TO
INDICATE THAT A COLD FRONT WILL MOVE ACROSS THE AREA ON LATE FRI/SAT
AS AN UPPER TROF DEEPENS OVER THE EAST COAST. THE FRONT IS EXPECTED
TO STALL OVER SOUTH OF THE AREA SUN AND DISSIPATES MON AS A RIDGE
BUILDS IN FROM THE SE. THE STRONGEST UPPER FORCING WILL REMAIN NORTH
OF THE AREA...HOWEVER GOOD OVERALL DYNAMICAL LIFT AND H3 DIV ALONG
WITH PLENTY OF LLVL INSTABILITY WILL BE AVAILABLE FOR SCATTERED
DIURNAL TSTMS EACH DAY THROUGH THE PERIOD. POPS WERE MAINTAINED AT
NEAR CLIMO...HOWEVER IF THIS PATTERN AND S/W TIMING PERSISTS OVER
THE NEXT COUPLE MODEL RUNS...AN INCREASE IN POPS WILL BE WARRANTED
FOR FRI/SAT. SUN LOOKS TO BE THE DRIEST DAY WITH FAIRLY STRONG HIGH
PRESSURE BUILDING IN...YET THE FRONT WILL REMAIN JUST TO THE
SOUTH...SO SLIGHT CHANCE POPS WERE MENTIONED THROUGH THE DAY. MON
WILL BE ACTIVE AGAIN AS ANOTHER SHOT OF UPPER ENERGY ROUNDS THE WRN
RIDGE AND TRAVERSES THE REGION. TEMPERATURES WILL BE NEAR...OR A
COUPLE DEGREES ABOVE NORMAL FRI/SAT. WITH NW/LY FLOW SETTING UP
SUN...EXPECT A COUPLE DEGREES COOLER IN THE MTNS SUN/MON. YET...A
GOOD DOWNSLOPE WARMING COMPONENT WILL ENABLE MAXES RIGHT AROUND
NORMAL OVER THE LOWER PIEDMONT.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AT KCLT...HAVE HELD ON TO TEMPO GROUP FOR CONVECTION FROM 20-22 UTC
THIS AFTN. TSTMS ARE MOVING INTO THE NC MTNS ATTM. HOWEVER...THEY
HAVE LOST SOME OF THEIR ORGANIZATION. I STILL THINK THEY WILL
ORGANIZE AS THEY EMERGE INTO THE FOOTHILLS AND CONFIDENCE IS STILL
GOOD IN A SQUALL LINE LATER IN THE AFTN. WINDS WILL PROBABLY AVERAGE
FROM THE WNW THE REST OF THE AFTN...THOUGH THEY MAY BACK TO THE WSW
AT TIMES. THEY WILL TURN MORE OUT OF THE NORTH BEHIND A WEAK COLD
FRONT LATE TONIGHT. WHILE NOTHING HAS BEEN CARRIED IN THE
TAF...THERE ARE INDICATIONS THAT SHRA/TSTM ACTIVITY COULD BE IN THE
VCNTY MUCH OF THE NIGHT.
ELSEWHERE...SCT TSTMS WILL CONTINUE TO DEVELOP ACROSS THE REGION
THIS AFTN. A STRONG SQUALL LINE IS EXPECTED TO DROP ACROSS THE
REGION THIS EVENING. FOR NOW I/M JUST GOING TO CARRY VCTS FOR
SEVERAL HOURS...BUT AS THE LINE GETS CLOSER WE SHOULD BE ABLE TO ADD
A PERIOD OF TEMPO OR PREVAILING THUNDER. A WEAK COLD FRONT WILL
STALL OVER THE REGION LATE TONIGHT...AND THIS MAY ALLOW SCT
SHRA/TSTMS TO LAST INTO THE MORNING HOURS...THOUGH FOR NOW THAT
HASN/T BEEN CARRIED IN THE TAF. WINDS WILL BE WSW TO W OVER THE
UPSTATE AND NW OVER WRN NC. WINDS LATER TONIGHT WILL BECOME LIGHT OR
SHIFT TO LIGHT OUT OF THE NORTH BEHIND THE FRONT AND THUNDERSTORM
COMPLEXES.
OUTLOOK...EXPECT SOLID CHC CONVECTION WED AFTERNOON AND EVENING.
BEST CHC OF OVERNIGHT RESTRICTIONS WILL BE IN AREAS THAT SEE LOCALLY
HEAVY RAIN. A COLD FRONT MAY BRING MORE WIDESPREAD CONVECTION FRI
AND FRI NIGHT.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JPT
NEAR TERM...MCAVOY
SHORT TERM...JPT
LONG TERM...JPT
AVIATION...RB
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
316 PM CDT TUE JUL 24 2012
.SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT
316 PM CDT TUE JUL 24 2012
FORECAST CONCERNS THIS PACKAGE...SHRA/TSRA CHANCES TONIGHT INTO FRI
NIGHT...SEVERE THREAT WED AFTERNOON/EVENING...DANGEROUS HEAT INDICES
WED AFTERNOON/EARLY WED EVENING.
DATA ANALYSIS AT 18Z HAD THE ORIGINAL FRONTAL BOUNDARY ACROSS
CENTRAL IL TO SOUTHERN IA WITH EAST TO SOUTHEAST FLOW NORTH OF IT.
SECONDARY BOUNDARY WAS LOCATED CENTRAL MN TO EAST CENTRAL WI...
ASSOCIATED WITH LINGERING SHRA/TSRA...CLOUDS AND COOLER TEMPS UNDER
THE CLOUDS. WEAK SHORTWAVE MOVING ACROSS EAST CENTRAL MN PLUS WINDS
BECOMING MORE SOUTHERLY ACROSS SOUTHERN MN ADVECTING THE MOIST/
UNSTABLE AIRMASS NORTHWARD OVER THE COOL DOME CONTINUES TO PRODUCE
SHRA AND OCCASIONAL TSRA FROM NORTH OF KLSE INTO NORTHEAST SD.
24.12Z MODELS INITIALIZED RATHER WELL...BUT FOR THE GFS WITH ITS
ABOUT 5F HIGH BIAS ON SFC DEW POINTS IN THE MOISTURE PLUME ACROSS
MUCH OF THE MID/UPPER MS VALLEY. SOLUTIONS QUITE SIMILAR THRU WED
NIGHT THEN BEGIN TO DIVERGE WITH THE SPEED OF THE SHORTWAVE TROUGH
TO DROP ACROSS THE WESTERN GREAT LAKES THU THRU FRI. DPROG/DT OF
500MB HGTS AT 24.12Z SHOWED MODEL RUNS OF 22.12Z AND 23.12Z
VERIFIED QUITE WELL ACROSS NOAM/EASTERN PAC...OFFERING A TIGHTER
COMPROMISE CONSENSUS OF THEIR EARLIER RUNS. CONSENSUS CONTINUES TO
TIGHTEN FOR TONIGHT THRU THU AS HGTS FALL...A STRONG SHORTWAVE
TROUGH TOPS THE CENTRAL NOAM RIDGE AND DROPS INTO THE WESTERN GREAT
LAKES. CONSISTENCY REMAINS QUITE GOOD THU NIGHT INTO FRI NIGHT AS
THIS TROUGH CROSSES WI THEN LIFTS OUT WITH RISING HGTS INTO THE
WEEKEND. ECMWF AGAIN MAINTAINS THE BETTER RUN-TO-RUN CONSISTENCY
THRU THE PERIOD. CHECK OF OBS VS. MODEL DATA AT 18Z SHOWED MODELS
REASONABLE WITH SFC FEATURES ACROSS THE CENTRAL CONUS. GFS REMAINED
TOO HIGH WITH SFC DEW POINTS OVER THE CORN BELT/MID MS VALLEY...
WHILE ECMWF WAS A BIT ON THE LOW SIDE. PER WV IMAGERY GEM/ECMWF
TENDED TO LOOK A BIT BETTER WITH THE SHORTWAVE DETAILS OVER CENTRAL
NOAM. ALL TENDED TO STRUGGLE A BIT WITH THE CONVECTION THIS MORNING/
EARLY THIS AFTERNOON ACROSS THE REGION. A COMPROMISE/ CONSENSUS
LOOKED BEST WITH THIS. NO CLEAR MODEL FAVORITE BUT WITH ECMWF
OFFERING SOME BETTER CONSISTENCY FAVORED A MODEL/ENSEMBLE BLEND
WEIGHTED TOWARD THE ECMWF. SHORT TERM FCST CONFIDENCE AVERAGE THIS
CYCLE.
IN THE SHORT TERM...WEAK SHORTWAVES RIPPLING SOUTHEAST ACROSS THE
AREA COMBINED WITH WEAK CONVERGENCE/LIFT NEAR THE ENHANCED THERMAL
ZONE LOOK TO CONTINUE PRODUCING SCT SHRA/TSRA ACROSS MAINLY THE
NORTHEAST 2/3 OF THE FCST AREA THIS AFTERNOON INTO THIS EVENING.
GIVEN CLOUD COVER TODAY AND LIMITED WARMING/DESTABILIZATION OVER
MUCH OF THE FCST AREA...SEVERE THREAT LATE THIS AFTERNOON/EVENING
LOOKS LOW BUT CANNOT BE RULED OUT.
AS THE NEXT STRONGER SHORTWAVE MOVES ACROSS THE DAKOTAS INTO MN
TONIGHT...STRONGER OF THE SFC-700MB MOISTURE TRANSPORT/THETA-E
CONVERGENCE/WARM ADVECTION FOCUS INTO WESTERN/NORTH-CENTRAL MN THIS
EVENING. CONSENSUS FOR THIS IS FURTHER NORTH THAN THE EARLIER RUNS
WITH MORE WARMING/CAPPING AT 700MB BUILDING OVER THE FCST AREA THRU
THE NIGHT. HAVE SHIFTED HIGHER SHRA/TSRA CHANCES TONIGHT/WED MORNING
NORTH AND EAST...TOWARD THE STRONGER FORCING AND EDGE OF THE
CAPPING. LOWERED RAIN CHANCES OVER THE SOUTH/WEST PARTS OF THE FCST
AREA INTO THE 15-30 PERCENT RANGE OR REMOVED THEM FOR THESE PERIODS.
A VERY WARM 925-700MB AIRMASS PROGGED TO ADVECT NORTHEAST ACROSS THE
CENTRAL/SOUTHEAST PARTS OF THE FCST AREA WED AS THE NEB/SD SFC-
850MB LOW/TROUGH LIFTS INTO CENTRAL/NORTHERN WI. WITH STRONGER
SOUTHWEST GRADIENT FLOW FOR MIXING ON WED...HIGHS ACROSS THE
SOUTHEAST 2/3 OF THE FCST AREA LOOK HEADED FOR THE 95 TO 103 RANGE.
THIS COMBINED WITH HIGHER HUMIDITY. HAVE ALREADY ISSUED A HEAT
ADVISORY FOR THE SOUTHEAST 1/3 OF THE FCST AREA FOR WED AFTERNOON/
EARLY EVENING AND WILL EXPAND THIS NORTHWARD TO INCLUDE PRESTON AND
WINONA MN EASTWARD TO ADAMS/JUNEAU COUNTIES IN WI. POTENTIAL TO
REACH EXCESSIVE HEAT WARNING CRITERIA OVER THE SOUTHEAST END OF THE
FCST AREA WED AFTERNOON BUT DEW POINTS IN QUESTION. POTENTIAL FOR
DEEP MIXING TO AS HIGH AS 800-750MB IN THE WARM SECTOR...WITH DEW
POINTS MIXING OUT INTO THE LOWER 60S. THESE DEW POINTS WOULD NOT
SUPPORT AN EXCESSIVE HEAT WARNING AND HAVE LEFT HEADLINE AS HEAT
ADVISORY FOR NOW.
NEXT CONCERN IS THE LOW/COLD FRONT TO MOVE SOUTHEAST ACROSS THE
AREA WED AFTERNOON/EVENING AND SEVERE THREAT. AIRMASS WILL BE
CAPPED WITH 700MB TEMPS IN THE +12C TO +13C RANGE. BOUNDARY LAYER
COLD ADVECTION WITH THE FRONT LOOKS TO ADVANCE SOUTHEAST BEFORE THE
850-700MB LEVELS COOL. QUESTION IF THERE WILL BE ENOUGH CONVERGENCE/
LIFT...SOME MDT SFC-850MB FN CONVERGENCE INDICATED...WITH THE
FRONTAL PASSAGE TO OVERCOME THE CAPPING. MODEL SOUNDINGS INDICATE
THE HIGHER CHANCE OF THIS OVER THE SOUTHEAST 1/3 TO HALF OF THE
FCST AREA LATER IN THE AFTERNOON. CAPPING WEAKEST WITH SFC TEMPS
AROUND 100F. LIMITED SHRA/TSRA CHANCES TO 30-50 PERCENT WED
AFTERNOON THEN LIMITED THESE TO MAINLY THE SOUTHEAST END OF THE FCST
AREA WED EVENING. ML CAPE AND INCREASING SHEAR WED AFTERNOON/EARLY
EVENING WOULD SUPPORT SEVERE RISK PER SWODY2. WITH THE DEEP MIXED
LAYER...INVERTED V SOUNDINGS AND BULK OF SHEAR IN THE 0-3KM LAYER...
ANY TSRA LOOK CAPABLE OF STRONG/DAMAGING WINDS.
STRONGER SHORTWAVE/TROUGH THEN DROPS SOUTHEAST ACROSS THE AREA
THU/THU NIGHT WITH STRONG HGT FALLS AND INCREASING PV ADVECTION
ALOFT. WITH A DIURNAL INCREASE OF CAPE AND THE DEEP LAYER CYCLONIC
FLOW/CONVERGENCE...SHRA/TSRA CHANCES IN THE 20-50 PERCENT RANGE...
HIGHEST OVER THE NORTH/EAST END OF THE FCST AREA...LOOK REASONABLE
THU AFTERNOON/EVENING AND BLEND WELL WITH NEIGHBORING GRIDS.
LINGERED A SMALL SHRA/TSRA CHANCE OVER THE NORTHEAST END OF THE FCST
AREA FRI WITH WEAK CAPE...STEEP LOW/MID LEVEL LAPSE RATES AND SOME
CYCLONIC CONVERGENCE. DRIER/COOLER HIGH PRESSURE BEGINS TO BUILD IN
FRI NIGHT.
GENERALLY FAVORED A BLEND OF THE NUMERICAL TEMP GUIDANCE FOR TONIGHT
THRU FRI NIGHT. HOWEVER...WITH STRONGER/DEEP MIXING UNDER THE 850-
700MB THERMAL RIDGE...DID FAVOR WARMER OF GUIDANCE HIGHS WED.
.LONG TERM...SATURDAY THROUGH TUESDAY
316 PM CDT TUE JUL 24 2012
24.00Z/24.12Z MEDIUM RANGE MODEL RUNS IN DECENT AGREEMENT WITH EACH
OTHER AND THEIR PREVIOUS RUNS SAT AS LONGWAVE TROUGHING MOVES INTO
THE EASTERN CONUS AND HGTS GRADUALLY RISE OVER THE UPPER MIDWEST.
CONSISTENCY REMAINS GOOD SUN FOR A WAVE TO TOP THE RIDGE AND MOVE
ACROSS THE REGION. MODELS CONVERGED TOWARD A COMPROMISE OF THEIR
EARLIER RUNS FOR SUNDAY. SOME CONSISTENCY AMONG MODELS FOR ANOTHER
SHORTWAVE TO TOP THE RIDGE AND MOVE ACROSS THE NORTHERN PLAINS/UPPER
MIDWEST MON/TUE. HOWEVER DIFFERENCES ON THE TIMING/STRENGTH DETAILS
INCREASE IN THE MON/TUE TIMEFRAME. LONG-TERM FCST CONFIDENCE ABOVE
AVERAGE SAT/SUN THEN AVERAGE MON/TUE. CANADIAN HIGH PRESSURE SETTLES
SOUTH ACROSS THE AREA SAT...EAST OF THE MID LEVEL RIDGE AXIS. A DRY/
SEASONABLE DAY EXPECTED FOR SAT. FIRST WAVE TOPPING THE RIDGE MOVES
INTO MN/IA/WI FOR SAT NIGHT/SUN. SFC-850MB MOISTURE/MOISTURE
TRANSPORT/WARM ADVECTION AHEAD OF THE SFC-LOW LEVEL TROUGH INCREASE
INTO THE AREA THRU SAT NIGHT/SUN...WITH SHRA/TSRA CHANCES SPREADING
BACK INTO/ACROSS THE AREA. THE SECOND WAVE FOR EARLY NEXT WEEK
KEEPS SOME LOWER LEVEL THERMO-DYNAMIC FORCING/LIFT OVER THE AREA
MON/TUE...ALONG WITH THE LOWERING HGTS AND SOME PV ADVECTION ALOFT.
SHRA/TSRA CHANCES LOOK TO CONTINUE ACROSS THE AREA MON/TUE. FAVORING
A MODEL/ENSEMBLE BLEND AND UNCERTAINTIES WITH CLOUD/SHRA/TSRA
COVERAGE ON DAYS 5-7...MODEL CONSENSUS HIGHS/LOWS FOR SAT THRU TUE
LOOK WELL TRENDED AT THIS TIME.
&&
.AVIATION...THROUGH 18Z WEDNESDAY
1240 PM CDT TUE JUL 24 2012
MONITORING THE MESOSCALE CONVECTIVE VORTEX SPINNING INTO THE
NORTHERN TWIN CITIES AREA...WHICH IS HELPING TO FUEL A LINE OF
THUNDERSTORMS FROM RED WING AND WABASHA BACK TO NEAR MANKATO. THIS
ACTIVITY IS BEING ENHANCED ALONG THE DIFFERENTIAL HEATING BOUNDARY
WHERE THE CLEAR AND MUGGY AIRMASS OVER SOUTHERN MN IS FEEDING INTO
THE COOL AIR ACROSS CENTRAL MN. THE LATEST 15Z HRRR MODEL SEEMS TO
HAVE A GOOD HANDLE ON THIS DEVELOPMENT AND TAKES A CONVECTIVE LINE
DOWN ACROSS THE TAF LOCATIONS BETWEEN 21Z AND 23Z. BEYOND
THAT...IT APPEARS THAT MOST OF THE CONVECTION THREAT WILL SHIFT
NORTH AND EAST OF THE TAF LOCATIONS. PLAYED THE FORECASTS THAT WAY
FOR THE 18Z ISSUANCE.
THERE IS SOME INDICATION VIA MODEL GUIDANCE THAT WE COULD SEE SOME
LIGHT FOG DEVELOP LATE TONIGHT DUE TO THE ADDITION OF THE BOUNDARY
LAYER MOISTURE VIA RAINFALL. HOWEVER...WITH SOUTHERLY WINDS ON THE
INCREASE...FEEL THE LOWER ATMOSPHERE WILL BE TOO MIXED TO ALLOW
FOR LIGHT FOG/MIST DEVELOPMENT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
316 PM CDT TUE JUL 24 2012
WI...HEAT ADVISORY FROM NOON TO 9 PM CDT WEDNESDAY FOR WIZ054-055-
061.
HEAT ADVISORY FROM NOON TO 7 PM CDT WEDNESDAY FOR WIZ041>044-
053.
MN...HEAT ADVISORY FROM NOON TO 7 PM CDT WEDNESDAY FOR MNZ088-095-
096.
IA...HEAT ADVISORY FROM NOON TO 9 PM CDT WEDNESDAY FOR IAZ010-011-
018-019-029-030.
HEAT ADVISORY FROM NOON TO 7 PM CDT WEDNESDAY FOR IAZ008-
&&
$$
SHORT TERM...RRS
LONG TERM....RRS
AVIATION.....MW
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1252 PM CDT TUE JUL 24 2012
.SHORT TERM...
1240 PM CDT TUE JUL 24 2012
AFTER ANALYZING A GOOD PORTION OF THE EARLY MORNING GUIDANCE
COMING IN...IT SEEMS PRETTY CERTAIN THAT HEAT ADVISORY CRITERIA
CONDITIONS WILL BE MET OVER THE SOUTHERN PORTION OF THE FORECAST
AREA TOMORROW AFTERNOON. THUS AFTER COORDINATION WITH SURROUNDING
OFFICES WE ISSUED A HEAT ADVISORY FOR NORTHEAST IA AND SOUTHWEST
WI.
ALSO MONITORING THE MESOSCALE CONVECTIVE VORTEX SPINNING INTO THE
NORTHERN TWIN CITIES AREA...WHICH IS HELPING TO FUEL A LINE OF
THUNDERSTORMS FROM RED WING AND WABASHA BACK TO NEAR MANKATO. THIS
ACTIVITY IS BEING ENHANCED ALONG THE DIFFERENTIAL HEATING BOUNDARY
WHERE THE CLEAR AND MUGGY AIRMASS OVER SOUTHERN MN IS FEEDING INTO
THE COOL AIR ACROSS CENTRAL MN. THE LATEST 15Z HRRR MODEL SEEMS TO
HAVE A GOOD HANDLE ON THIS DEVELOPMENT AND TAKES A CONVECTIVE LINE
DOWN ACROSS THE AREA LATER THIS AFTERNOON. WILL MAKE ADJUSTMENTS
TO THE FORECAST GRIDS AND TEXT FORECASTS AS THIS MOVES THROUGH.
.LONG TERM...FRIDAY THROUGH MONDAY
330 AM CDT TUE JUL 24 2012
24.00 FORECAST MODELS ARE IN AGREEMENT FRIDAY THROUGH SATURDAY
INDICATING SURFACE NORTHWEST FLOW ALOFT AND SURFACE HIGH PRESSURE IN
PLACE ACROSS THE UPPER MISSISSIPPI RIVER VALLEY. PLAN ON VERY
COMFORTABLE TEMPERATURES ON FRIDAY WITH HIGHS RANGING FROM THE MID 70S
ACROSS NORTHERN WISCONSIN TO AROUND 80 OVER NORTHEAST IOWA. ANOTHER
PLEASANT DAY IS ANTICIPATED ACROSS THE REGION ON SATURDAY WITH
MOSTLY SUNNY SKIES AND HIGHS IN THE 80S. A WEAK EMBEDDED SHORTWAVE
WILL MOVE INTO THE REGION LATE SATURDAY NIGHT INTO SUNDAY BRINGING A
CHANCE OF SHOWERS AND THUNDERSTORMS TO THE AREA. SHOWER AND
THUNDERSTORM CHANCES WILL CONTINUE THROUGH MONDAY AS WEAK UPPER LEVEL
SHORTWAVES MOVE ACROSS THE UPPER MIDWEST. TEMPERATURES LOOK TO HOVER
AROUND SEASONAL VALUES WITH HIGHS RANGING FROM THE LOWER TO UPPER
80S.
&&
.AVIATION...THROUGH 18Z WEDNESDAY
1240 PM CDT TUE JUL 24 2012
MONITORING THE MESOSCALE CONVECTIVE VORTEX SPINNING INTO THE
NORTHERN TWIN CITIES AREA...WHICH IS HELPING TO FUEL A LINE OF
THUNDERSTORMS FROM RED WING AND WABASHA BACK TO NEAR MANKATO. THIS
ACTIVITY IS BEING ENHANCED ALONG THE DIFFERENTIAL HEATING BOUNDARY
WHERE THE CLEAR AND MUGGY AIRMASS OVER SOUTHERN MN IS FEEDING INTO
THE COOL AIR ACROSS CENTRAL MN. THE LATEST 15Z HRRR MODEL SEEMS TO
HAVE A GOOD HANDLE ON THIS DEVELOPMENT AND TAKES A CONVECTIVE LINE
DOWN ACROSS THE TAF LOCATIONS BETWEEN 21Z AND 23Z. BEYOND
THAT...IT APPEARS THAT MOST OF THE CONVECTION THREAT WILL SHIFT
NORTH AND EAST OF THE TAF LOCATIONS. PLAYED THE FORECASTS THAT WAY
FOR THE 18Z ISSUANCE.
THERE IS SOME INDICATION VIA MODEL GUIDANCE THAT WE COULD SEE SOME
LIGHT FOG DEVELOP LATE TONIGHT DUE TO THE ADDITION OF THE BOUNDARY
LAYER MOISTURE VIA RAINFALL. HOWEVER...WITH SOUTHERLY WINDS ON THE
INCREASE...FEEL THE LOWER ATMOSPHERE WILL BE TOO MIXED TO ALLOW
FOR LIGHT FOG/MIST DEVELOPMENT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
1240 PM CDT TUE JUL 24 2012
WI...HEAT ADVISORY FROM NOON TO 7 PM CDT WEDNESDAY FOR WIZ053>055-061.
MN...NONE.
IA...HEAT ADVISORY FROM NOON TO 7 PM CDT WEDNESDAY FOR IAZ008>011-018-
019-029-030.
&&
$$
SHORT TERM...MW
LONG TERM...WETENKAMP
AVIATION...MW
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1201 PM CDT TUE JUL 24 2012
.AVIATION/18Z TAFS/...VFR FOR THIS FORECAST PERIOD. MAIN CONCERN
WILL BE ON PRECIP/CONVECTION ASSOCIATED WITH 850 BAROCLINIC ZONE
AND RETURN LOW LEVEL JET TONIGHT. MAIN FOCUS EXPECTED TO BE ACROSS
NW WI...THOUGH MESO MODELS DO DEVELOP SCATTERED CONVECTION ACROSS
SRN WI LATER TONIGHT. ANY MVFR CEILINGS EXPECTED TO BE SHORT
LIVED. CONVECTION EXPECTED TO WHISK NE AS HOT AIRMASS OVERTAKES
THE AREA. THE NAM AND GFS APPEAR TOO QUICK AND FAR SOUTHEAST INTO
THE HOT AIRMASS WITH THE QPF WEDNESDAY AFTERNOON. MAY NEED TO WAIT
FOR BETTER LOW LEVEL FRONTAL FORCING TO BREAK THE CAP WEDNESDAY EVENING.
PC
&&
.PREV DISCUSSION... /ISSUED 1000 AM CDT TUE JUL 24 2012/
UPDATE...HOISTED HEAT ADVISORY FOR WEDNESDAY. IMPRESSIVELY HOT
THERMAL AXIS DRIVES INTO SRN WI. 925 TEMPS SOAR INTO THE LOW TO
MID 30S AND 850 TEMPS 26-29C...VERY CONDUCIVE TO OPPRESSIVELY HOT
TEMPERATURES. HIGHER DEW POINTS EXPECTED...UPPER 60S/LOW 70S. NAM
DEWS WHICH HAVE BEEN BETTER OF LATE ARE EVEN SUGGESTING SOME DEWS
NEAR 70. GFS DEWS IN MID 70S...TYPICALLY TOO MOIST...THOUGH BL
LAYER BECOMING MORE FAVORABLE FOR HIGHER DEWS WITH THE RECENT
RAINS IN SOME AREAS.
PC
PREV DISCUSSION... /ISSUED 339 AM CDT TUE JUL 24 2012/
TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM
DIMINISHING TREND NOTED IN CONVECTION OVER SOUTHWEST WI OVER LAST
HOUR OR SO. SCATTERED TO NUMEROUS CONVECTION EXTENDS WELL TO THE
WEST ACROSS SOUTHERN MN INTO EASTERN SODAK. HOWEVER FRONTAL
BOUNDARY SAGGING ACROSS SOUTHERN WI ATTM...WL CONTINUE INTO NRN IL
EARLY THIS MRNG. THIS WILL TIGHTEN THE BAROCLINICITY ACROSS
SOUTHERN WI AND INCREASE THE LOW LEVEL FN VECTOR RESPONSE TO
FRONTOGENESIS. THIS SHOULD HELP CONTINUE THE SCATTERED TO NUMEROUS
CONVECTION OVER PORTIONS OF SOUTHERN WISCONSIN THROUGH MID-MORNING
BEFORE DIMINISHING. PWAT VALUES IN THE 1.75 TO 2.0 INCH
RANGE...WHICH IS ABOUT 160 PERCENT OF NORMAL. BOTH THE RAP AND
NAM40KM SHOW LAYER FWF LINGERING OVER SOUTH CENTRAL WI TO AROUND 15Z
BEFORE DIMINISHING. HENCE WL CONTINUE LIKELY WORDING IN THE SOUTH
CENTRAL AREAS...DIMINISHING TO CHC/SCT IN THE NORTHEAST.
UPSTREAM SHORT WAVE OVER ERN SODAK IS EXPECTED TO MOVE ESE ACROSS
SRN MN INTO SRN WI LATER THIS MRNG...SO WL CONTINUE CHANCE INTO THE
LATE MORNING. SHORT WAVE AND FRONTOGENETICAL FORCING WEAKENS AND
SLIDES SOUTHEAST FOR THE AFTN.
STRONG SURGE OF RETURN FLOW AND LOW LEVEL THETA-E ADVECTION
ACCOMPANY DEVELOPING LOW LEVEL JET TONIGHT. FOCUS OF LLJ TO THE
NORTHWEST OF CWA...HOWEVER STILL GET CLIPPED BY INCREASING WARM AIR
ADVECTION. HENCE WL CONTINUE LIKELY POPS IN THE NORTH TONIGHT.
WEDNESDAY AND THURSDAY...FORECAST CONFIDENCE...MEDIUM
CONVECTION NEAR WARM FRONT SHOULD WIND DOWN WEDNESDAY MORNING ACROSS
THE NORTHERN FORECAST AREA. WARM FRONT THEN EXPECTED TO LINGER JUST
NORTH OF THE CWA THROUGH THE DAY. MODELS INDICATING THAT TEMPS WILL
SOAR IN THE WARM SECTOR...WITH 925 MB TEMPS UP TO AROUND 32C ON THE
ECMWF AND EVEN WARMER WITH THE NAM. CONCERN IS CERTAINLY THERE THAT
OVERNIGHT CONVECTION MAY KEEP THE WARM FRONT FARTHER SOUTH...AND
THEN ALSO PULL IN COOLER AIR OFF THE LAKE NORTH OFF THE FRONT. FOR
NOW THOUGH...WENT WITH WHAT THE MODELS ARE SHOWING AND BUMPED TEMPS
UP TO AROUND 100 MOST PLACES...EXCEPT FOR IN THE NORTH TOWARD THE
WARM FRONT. TOO MUCH UNCERTAINTY WITH LINGERING CONVECTION/CLOUDS
AND PLACEMENT OF THE WARM FRONT...SO HELD OFF ON HEAT ADVISORY FOR
NOW. WILL EVENTUALLY NEED ONE IF MODELS CONTINUE DOWN THIS ROAD AND
FORECAST CONFIDENCE INCREASES. EVEN WITH DEWPOINTS MIXING INTO THE
MID AND UPPER 60S...TEMPS AROUND 100 WOULD RESULT IN HEAT INDICES IN
THE 100-105 RANGE.
CONVECTION WITH THE TRAILING COLD FRONT IS EXPECTED TO MAINLY HOLD
OFF UNTIL THE EVENING AND OVERNIGHT HOURS. WITH 30 KT LLJ ACROSS THE
AREA AND CAPES IN EXCESS OF 1000 J/KG...STILL THINKING STORMS SEVERE
STORMS ARE A POSSIBILITY AND SPC IS MAINTAINING A SLIGHT RISK.
KEPT SOME POPS THURSDAY MORNING...AS THE ECMWF LINGERS POST FRONTAL
PRECIP. OTHERWISE...SHOULD MAINLY BE DRY THURSDAY. A WEAK WAVE MAY
BRING A FEW MORE SHOWERS/STORMS TO THE AREA LATER IN THE DAY AND
OVERNIGHT.
THINKING THE SUN MAY POKE OUT FOR A TIME THURSDAY...SO PUSHED HIGHS
UP INTO THE MID AND UPPER 80S PER 925 MB TEMPS IN THE 22-25C RANGE.
FRIDAY AND SATURDAY...FORECAST CONFIDENCE...MEDIUM
PRECIP MAY LINGER INTO FRIDAY MORNING AS THE SHORTWAVE EXITS...WITH
DRY WEATHER EXPECTED SATURDAY AS SFC HIGH PRESSURE MOVES OVERHEAD.
SHOULD SEE HIGHS COMFORTABLY NEAR NORMAL BOTH DAYS.
SUNDAY AND MONDAY...FORECAST CONFIDENCE...MEDIUM
WITH UPPER RIDGE BUILDING IN TO THE WEST SUNDAY AND
MONDAY...COMBINATION OF WARM AIR ADVECTION AND A WEAK WAVE OR TWO
MAY KICK OFF SHOWERS/STORMS AT TIMES. WILL LIKELY SEE TEMPS START TO
WARM BACK UP.
AVIATION/12Z TAFS/...SCATTERED TO NUMEROUS CONVECTION LIKELY THIS
MORNING WITH MOST NUMEROUS CONVECTION TOWARDS KMSN. ENOUGH RAINFALL
TO MOISTEN LOW LEVELS EXPECTED TO PRODUCE PERIOD OF MVFR CIGS AT
KMSN. NOT AS CONFIDENT ON LOW CIGS FARTHER EAST WHERE RAINFALL MAY
BE A BIT MORE SCATTERED. MAY USE A TEMPO GROUP WITH 12Z ISSUANCE.
ANY LOWER CIGS SHOULD LIFT TO VFR THIS AFTN AS FORCING SLIDES SOUTH
OF AREA AND SLIGHTLY DRIER AIR GETS PULLED INTO THE LOWER LEVELS.
MORE SCT CONVECTION TONIGHT WITH STRONG RETURN FLOW.
MARINE...ONE TO TWO HOURS OF GUSTY NORTHEAST WINDS ACCOMPANIED
FROPA AS IT MOVED SOUTH ALONG THE LAKE MICHIGAN SHORE EARLY THIS
MORNING. THE FRONT WILL CONTINUE SAGGING SOUTHWARD WITH NORTHEAST
WINDS SETTLING DOWN TO 5 TO 15 KNOTS. SCATTERED T TO AFFECT NEAR
SHORE WATERS THIS MORNING AND AGAIN LATER TNGT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...HEAT ADVISORY FROM 11 AM TO 9 PM CDT WEDNESDAY FOR WIZ051-052-
058>060-062>072.
HEAT ADVISORY FROM 11 AM TO 7 PM CDT WEDNESDAY FOR WIZ046-047-
056-057.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...MBK
WEDNESDAY THROUGH MONDAY...DDV