Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/15/12
AREA FORECAST DISCUSSION...UPDATED
NWS LITTLE ROCK AR
1223 PM CDT MON AUG 13 2012
.DISCUSSION...
UPDATED FOR 18Z AVIATION DISCUSSION BELOW...
&&
.AVIATION...
FRONT PUSHING SE ACROSS THE STATE THIS AFTERNOON...WITH DRIER AIR
FILTERING INTO WRN SECTIONS OF THE STATE. THIS WILL KEEP VFR
CONDITIONS IN PLACE FOR MOST TAF SITES. SOME SHRA/TSRA WILL BE
POSSIBLE AHEAD OF THE FRONT THIS AFTERNOON...MAINLY ACROSS FAR ERN
AND SERN SECTIONS OF AR. HAVE MENTIONED VCTS AT LLQ FOR THIS
REASON. TAFS ALREADY OUT.
&&
.PREV DISCUSSION... /ISSUED 1043 AM CDT MON AUG 13 2012/
UPDATE...
15Z SURFACE ANALYSIS INDICATES THE COLD FRONT HAS REACHED A LINE
FROM FLIPPIN...TO JUST SOUTH OF MENA. FORECASTS HAVE BEEN ADJUSTED
TO LOWER PRECIPITATION CHANCES THIS AFTERNOON...AS A FAIR AMOUNT
OF CONVECTIVE OVERTURNING HAS OCCURRED AHEAD OF THE BOUNDARY.
55
PREV DISCUSSION... /ISSUED 500 AM CDT MON AUG 13 2012/
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
WL BE BRIEF THIS MRNG DUE TO STRONG/SVR STORMS OVR THE AREA. WARM
FNT WAS LOCATED ACRS CNTRL AR EARLY THIS MRNG. CONVECTION DVLPD
UPSTREAM OF THE FA LATE SUN EVENING AND EVENTUALLY TRACKED ALONG THE
BNDRY OVERNIGHT INTO NRN AND CNTRL AR. THIS ACTIVITY IS EXPECTED TO
CONT WORKING EWD THRU THE MRNG HRS AS ASSOCD SHRTWV MOVES THRU THE
REGION.
AFTER THE MRNG CONVECTIVE ACTIVITY...FOCUS WL SHIFT TO THE CDFNT
THAT WL MOVE THRU THE AREA LATER TODAY AND EARLY TNGT. THE FNT WAS
CURRENTLY ALONG THE I-44 CORRIDOR. THE POTENTIAL FOR STORMS TO FIRE
ALONG THE ACTUAL FNTL BNDRY LATER TODAY IS THE MAIN CONCERN. LAST
FEW RUNS OF THE HRRR MODEL INDC THAT SCTD STORMS SHLD DVLP THIS
AFTN...MAINLY ACRS ERN AND SRN AR.
FNTL BNDRY WL EVENTUALLY STALL OUT S OF AR BY TUE AS HIGH PRES BLDS
INTO THE REGION. HOWEVER...NWLY FLOW ALOFT WL BRING SEVERAL IMPULSES
SEWD TOWARD THE FA LATER TUE AND WED. THESE FEATURES WL PRODUCE SCTD
CONVECTION OVR PORTIONS OF THE AREA...WITH THE MAIN FOCUS ACRS THE
SWRN HALF OF THE STATE. UNSETTLED CONDS WL CONT INTO THE LONG TERM
AS A NEW CDFNT APCHS FM THE PLAINS.
LONG TERM...THURSDAY THROUGH SUNDAY
GUIDANCE IN RELATIVELY GOOD AGREEMENT IN THE LONG TERM IN SHOWING
WIDESPREAD RAINFALL FOR THE END OF THE WEEK. WARM FRONT WILL MOVE
NORTH THURSDAY BRINGING GULF MOISTURE TO THE STATE...AND COLD FRONT
WILL APPROACH THURSDAY NIGHT INTO FRIDAY. THERE IS A POSSIBILITY FOR
SOME SIGNIFICANT RAINFALL...BUT THIS SYSTEM IS SEVERAL DAYS
AWAY...AND SEVERAL DETAILS WILL NEED TO IRONED OUT IN REGARDS TO
RAINFALL AMOUNTS. THE GOOD NEWS IS THAT COOLER TEMPERATURES WILL
FOLLOW THE FRONT...WITH HIGHS IN THE 80S AND LOWER 90S.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 91 65 86 65 / 30 10 10 10
CAMDEN AR 95 67 91 67 / 50 20 10 20
HARRISON AR 88 63 84 66 / 10 0 10 10
HOT SPRINGS AR 95 67 89 67 / 30 10 20 20
LITTLE ROCK AR 93 67 87 67 / 40 10 10 20
MONTICELLO AR 94 69 89 68 / 50 20 10 10
MOUNT IDA AR 93 65 89 64 / 20 10 20 20
MOUNTAIN HOME AR 89 63 85 63 / 10 0 10 10
NEWPORT AR 91 66 86 65 / 40 10 10 10
PINE BLUFF AR 93 67 88 66 / 50 20 10 10
RUSSELLVILLE AR 91 67 88 66 / 10 10 10 20
SEARCY AR 90 66 86 65 / 40 10 10 10
STUTTGART AR 91 67 87 66 / 50 20 10 10
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AVIATION...62
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
1043 AM CDT MON AUG 13 2012
.UPDATE...
15Z SURFACE ANALYSIS INDICATES THE COLD FRONT HAS REACHED A LINE
FROM FLIPPIN...TO JUST SOUTH OF MENA. FORECASTS HAVE BEEN ADJUSTED
TO LOWER PRECIPITATION CHANCES THIS AFTERNOON...AS A FAIR AMOUNT
OF CONVECTIVE OVERTURNING HAS OCCURRED AHEAD OF THE BOUNDARY.
55
&&
.PREV DISCUSSION... /ISSUED 626 AM CDT MON AUG 13 2012/
AVIATION...
AREA OF CONVECTION MOVING ACROSS CENTRAL ARKANSAS THIS
MORNING...AS SHORTWAVES MOVES ACROSS THE STATE. THIS AREA OF
CONVECTION WILL MOVE OUT OF THE AREA IN THE NEXT COUPLE OF
HOURS...AND MAY CLIP KPBF THIS MORNING. EXPECT SOME REDEVELOPMENT
ACROSS SOUTHEAST ARKANSAS LATER THIS AFTERNOON AS COLD FRONT MOVES
INTO THE STATE. ACROSS THE NORTH...SKIES HAVE ALREADY
CLEARED...BUT SOME MVFR CIGS COULD DEVELOP LATER ON THIS MORNING.
WILL HAVE TO MONITOR FOR FOG DEVELOPMENT TONIGHT...ESPECIALLY IN
AREAS THAT RECEIVED HEAVY RAIN TODAY.
PREV DISCUSSION... /ISSUED 500 AM CDT MON AUG 13 2012/
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
WL BE BRIEF THIS MRNG DUE TO STRONG/SVR STORMS OVR THE AREA. WARM
FNT WAS LOCATED ACRS CNTRL AR EARLY THIS MRNG. CONVECTION DVLPD
UPSTREAM OF THE FA LATE SUN EVENING AND EVENTUALLY TRACKED ALONG THE
BNDRY OVERNIGHT INTO NRN AND CNTRL AR. THIS ACTIVITY IS EXPECTED TO
CONT WORKING EWD THRU THE MRNG HRS AS ASSOCD SHRTWV MOVES THRU THE
REGION.
AFTER THE MRNG CONVECTIVE ACTIVITY...FOCUS WL SHIFT TO THE CDFNT
THAT WL MOVE THRU THE AREA LATER TODAY AND EARLY TNGT. THE FNT WAS
CURRENTLY ALONG THE I-44 CORRIDOR. THE POTENTIAL FOR STORMS TO FIRE
ALONG THE ACTUAL FNTL BNDRY LATER TODAY IS THE MAIN CONCERN. LAST
FEW RUNS OF THE HRRR MODEL INDC THAT SCTD STORMS SHLD DVLP THIS
AFTN...MAINLY ACRS ERN AND SRN AR.
FNTL BNDRY WL EVENTUALLY STALL OUT S OF AR BY TUE AS HIGH PRES BLDS
INTO THE REGION. HOWEVER...NWLY FLOW ALOFT WL BRING SEVERAL IMPULSES
SEWD TOWARD THE FA LATER TUE AND WED. THESE FEATURES WL PRODUCE SCTD
CONVECTION OVR PORTIONS OF THE AREA...WITH THE MAIN FOCUS ACRS THE
SWRN HALF OF THE STATE. UNSETTLED CONDS WL CONT INTO THE LONG TERM
AS A NEW CDFNT APCHS FM THE PLAINS.
LONG TERM...THURSDAY THROUGH SUNDAY
GUIDANCE IN RELATIVELY GOOD AGREEMENT IN THE LONG TERM IN SHOWING
WIDESPREAD RAINFALL FOR THE END OF THE WEEK. WARM FRONT WILL MOVE
NORTH THURSDAY BRINGING GULF MOISTURE TO THE STATE...AND COLD FRONT
WILL APPROACH THURSDAY NIGHT INTO FRIDAY. THERE IS A POSSIBILITY FOR
SOME SIGNIFICANT RAINFALL...BUT THIS SYSTEM IS SEVERAL DAYS
AWAY...AND SEVERAL DETAILS WILL NEED TO IRONED OUT IN REGARDS TO
RAINFALL AMOUNTS. THE GOOD NEWS IS THAT COOLER TEMPERATURES WILL
FOLLOW THE FRONT...WITH HIGHS IN THE 80S AND LOWER 90S.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 91 65 86 65 / 30 10 10 10
CAMDEN AR 95 67 91 67 / 50 20 10 20
HARRISON AR 88 63 84 66 / 10 0 10 10
HOT SPRINGS AR 95 67 89 67 / 30 10 20 20
LITTLE ROCK AR 93 67 87 67 / 40 10 10 20
MONTICELLO AR 94 69 89 68 / 50 20 10 10
MOUNT IDA AR 93 65 89 64 / 20 10 20 20
MOUNTAIN HOME AR 89 63 85 63 / 10 0 10 10
NEWPORT AR 91 66 86 65 / 40 10 10 10
PINE BLUFF AR 93 67 88 66 / 50 20 10 10
RUSSELLVILLE AR 91 67 88 66 / 10 10 10 20
SEARCY AR 90 66 86 65 / 40 10 10 10
STUTTGART AR 91 67 87 66 / 50 20 10 10
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AVIATION...99
AREA FORECAST DISCUSSION...UPDATED
NWS LITTLE ROCK AR
626 AM CDT MON AUG 13 2012
.AVIATION...
AREA OF CONVECTION MOVING ACROSS CENTRAL ARKANSAS THIS
MORNING...AS SHORTWAVES MOVES ACROSS THE STATE. THIS AREA OF
CONVECTION WILL MOVE OUT OF THE AREA IN THE NEXT COUPLE OF
HOURS...AND MAY CLIP KPBF THIS MORNING. EXPECT SOME REDEVELOPMENT
ACROSS SOUTHEAST ARKANSAS LATER THIS AFTERNOON AS COLD FRONT MOVES
INTO THE STATE. ACROSS THE NORTH...SKIES HAVE ALREADY
CLEARED...BUT SOME MVFR CIGS COULD DEVELOP LATER ON THIS MORNING.
WILL HAVE TO MONITOR FOR FOG DEVELOPMENT TONIGHT...ESPECIALLY IN
AREAS THAT RECEIVED HEAVY RAIN TODAY.
&&
.PREV DISCUSSION... /ISSUED 500 AM CDT MON AUG 13 2012/
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
WL BE BRIEF THIS MRNG DUE TO STRONG/SVR STORMS OVR THE AREA. WARM
FNT WAS LOCATED ACRS CNTRL AR EARLY THIS MRNG. CONVECTION DVLPD
UPSTREAM OF THE FA LATE SUN EVENING AND EVENTUALLY TRACKED ALONG THE
BNDRY OVERNIGHT INTO NRN AND CNTRL AR. THIS ACTIVITY IS EXPECTED TO
CONT WORKING EWD THRU THE MRNG HRS AS ASSOCD SHRTWV MOVES THRU THE
REGION.
AFTER THE MRNG CONVECTIVE ACTIVITY...FOCUS WL SHIFT TO THE CDFNT
THAT WL MOVE THRU THE AREA LATER TODAY AND EARLY TNGT. THE FNT WAS
CURRENTLY ALONG THE I-44 CORRIDOR. THE POTENTIAL FOR STORMS TO FIRE
ALONG THE ACTUAL FNTL BNDRY LATER TODAY IS THE MAIN CONCERN. LAST
FEW RUNS OF THE HRRR MODEL INDC THAT SCTD STORMS SHLD DVLP THIS
AFTN...MAINLY ACRS ERN AND SRN AR.
FNTL BNDRY WL EVENTUALLY STALL OUT S OF AR BY TUE AS HIGH PRES BLDS
INTO THE REGION. HOWEVER...NWLY FLOW ALOFT WL BRING SEVERAL IMPULSES
SEWD TOWARD THE FA LATER TUE AND WED. THESE FEATURES WL PRODUCE SCTD
CONVECTION OVR PORTIONS OF THE AREA...WITH THE MAIN FOCUS ACRS THE
SWRN HALF OF THE STATE. UNSETTLED CONDS WL CONT INTO THE LONG TERM
AS A NEW CDFNT APCHS FM THE PLAINS.
LONG TERM...THURSDAY THROUGH SUNDAY
GUIDANCE IN RELATIVELY GOOD AGREEMENT IN THE LONG TERM IN SHOWING
WIDESPREAD RAINFALL FOR THE END OF THE WEEK. WARM FRONT WILL MOVE
NORTH THURSDAY BRINGING GULF MOISTURE TO THE STATE...AND COLD FRONT
WILL APPROACH THURSDAY NIGHT INTO FRIDAY. THERE IS A POSSIBILITY FOR
SOME SIGNIFICANT RAINFALL...BUT THIS SYSTEM IS SEVERAL DAYS
AWAY...AND SEVERAL DETAILS WILL NEED TO IRONED OUT IN REGARDS TO
RAINFALL AMOUNTS. THE GOOD NEWS IS THAT COOLER TEMPERATURES WILL
FOLLOW THE FRONT...WITH HIGHS IN THE 80S AND LOWER 90S.
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AVIATION...58
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
500 AM CDT MON AUG 13 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
WL BE BRIEF THIS MRNG DUE TO STRONG/SVR STORMS OVR THE AREA. WARM
FNT WAS LOCATED ACRS CNTRL AR EARLY THIS MRNG. CONVECTION DVLPD
UPSTREAM OF THE FA LATE SUN EVENING AND EVENTUALLY TRACKED ALONG THE
BNDRY OVERNIGHT INTO NRN AND CNTRL AR. THIS ACTIVITY IS EXPECTED TO
CONT WORKING EWD THRU THE MRNG HRS AS ASSOCD SHRTWV MOVES THRU THE
REGION.
AFTER THE MRNG CONVECTIVE ACTIVITY...FOCUS WL SHIFT TO THE CDFNT
THAT WL MOVE THRU THE AREA LATER TODAY AND EARLY TNGT. THE FNT WAS
CURRENTLY ALONG THE I-44 CORRIDOR. THE POTENTIAL FOR STORMS TO FIRE
ALONG THE ACTUAL FNTL BNDRY LATER TODAY IS THE MAIN CONCERN. LAST
FEW RUNS OF THE HRRR MODEL INDC THAT SCTD STORMS SHLD DVLP THIS
AFTN...MAINLY ACRS ERN AND SRN AR.
FNTL BNDRY WL EVENTUALLY STALL OUT S OF AR BY TUE AS HIGH PRES BLDS
INTO THE REGION. HOWEVER...NWLY FLOW ALOFT WL BRING SEVERAL IMPULSES
SEWD TOWARD THE FA LATER TUE AND WED. THESE FEATURES WL PRODUCE SCTD
CONVECTION OVR PORTIONS OF THE AREA...WITH THE MAIN FOCUS ACRS THE
SWRN HALF OF THE STATE. UNSETTLED CONDS WL CONT INTO THE LONG TERM
AS A NEW CDFNT APCHS FM THE PLAINS.
&&
.LONG TERM...THURSDAY THROUGH SUNDAY
GUIDANCE IN RELATIVELY GOOD AGREEMENT IN THE LONG TERM IN SHOWING
WIDESPREAD RAINFALL FOR THE END OF THE WEEK. WARM FRONT WILL MOVE
NORTH THURSDAY BRINGING GULF MOISTURE TO THE STATE...AND COLD FRONT
WILL APPROACH THURSDAY NIGHT INTO FRIDAY. THERE IS A POSSIBILITY FOR
SOME SIGNIFICANT RAINFALL...BUT THIS SYSTEM IS SEVERAL DAYS
AWAY...AND SEVERAL DETAILS WILL NEED TO IRONED OUT IN REGARDS TO
RAINFALL AMOUNTS. THE GOOD NEWS IS THAT COOLER TEMPERATURES WILL
FOLLOW THE FRONT...WITH HIGHS IN THE 80S AND LOWER 90S.
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...44 / LONG TERM...58
AREA FORECAST DISCUSSION
NWS TUCSON AZ
220 PM MST MON AUG 13 2012
.SYNOPSIS...EXPECT HOT DAYTIME TEMPERATURES TUESDAY WITH RECORD OR
NEAR RECORD HIGHS IN SOME LOCATIONS. OTHERWISE...EXPECT A GRADUAL
INCREASE IN THUNDERSTORM CHANCES AND A GRADUAL COOLING TREND THIS
WEEK.
&&
.DISCUSSION...SCATTERED SHOWERS AND THUNDERSTORMS ONGOING ACROSS SE
AZ AT THIS TIME. 18Z RUC HRRR FAVORS THE TOHONO O`ODHAM NATION WITH
THE MOST SIGNIFICANT SHOWER/TSTM ACTIVITY DURING THE NEXT FEW HOURS.
MEANWHILE...ADDITIONAL SHOWERS/TSTMS ARE PROGGED TO DEVELOP FURTHER
EAST AND SOUTH OF TUCSON LATE THIS AFTERNOON AND EARLY THIS EVENING.
13/18Z SPECIAL KTWC SOUNDING YIELDED A FAIRLY DRY REGIME...WITH
PRECIP WATER AROUND 0.90 INCH WITH MINIMAL CAPE. STEERING FLOW WAS
SELY ONLY AROUND 5 KTS OR SO. THUS...THE MAIN THREAT DURING THE NEXT
FEW HOURS WILL BE BRIEF STRONG WIND GUSTS FOLLOWED BY PERHAPS
LOCALLY HEAVY RAINFALL LATE THIS AFTERNOON AND EARLY THIS EVENING.
THE OFFICIAL FORECAST DEPICTS SCATTERED SHOWERS/TSTMS MOST SECTIONS
THRU THIS EVENING. HAVE MAINTAINED A SLIGHT CHANCE OF SHOWERS/TSTMS
EAST AND SOUTH OF TUCSON LATE TONIGHT WITH GENERALLY PRECIP-FREE
CONDITIONS ELSEWHERE.
TUE-FRI...
DAILY PRECIP CHANCES WILL INCREASE ESPECIALLY THUR-FRI AS FAVORABLE
FLOW IMPORTS DEEPER MOISTURE INTO SE AZ. IN SUMMARY...SCATTERED
MAINLY AFTERNOON AND EVENING SHOWERS/TSTMS TO OCCUR PARTICULARLY
FROM TUCSON EWD/SWD WITH SLIGHTLY LESSER SHOWER/TSTM ACTIVITY ACROSS
WRN SECTIONS.
SAT-MON...
SLIGHTLY LESS SHOWER/TSTM ACTIVITY THIS PERIOD VERSUS THUR-FRI.
THERE WILL STILL BE ENOUGH MOISTURE TO JUSTIFY CHANCE-CATEGORY POPS
MOST SECTIONS...ESPECIALLY DURING THE AFTERNOON/EVENING HOURS. AT
THIS TIME APPEARS THAT THE FAVORED AREAS FOR SHOWERS/TSTMS WILL BE
ACROSS THE WHITE MOUNTAINS AS WELL AS ACROSS SANTA CRUZ COUNTY AND
SOUTHERN COCHISE COUNTY.
HIGH TEMPS TUE WILL STILL AVERAGE NEARLY 10 DEGS F ABOVE NORMAL.
COOLING TREND TO OCCUR WED-FRI DUE TO THE PROSPECT FOR INCREASED
MOISTURE ACROSS THE AREA. DAYTIME TEMPS SAT-MON EXPECTED AT THIS
TIME TO BE SLIGHTLY ABOVE NORMAL.
&&
.AVIATION...ISOLD-SCT TSRA/SHRA INTO THIS EVENING THEN A SLIGHT
CHANCE OF -TSRA/-SHRA EAST OF KTUS 06Z-12Z TUESDAY. SCT TSRA/SHRA
TUESDAY AFTERNOON. OTHERWISE...VFR CONDITIONS AND SURFACE WIND
GENERALLY LESS THAN 10 KTS THRU TUESDAY AFTERNOON OR 15/00Z.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...EXPECT SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS THROUGH THE WEEKEND. STRONG...ERRATIC AND GUSTY WINDS
WILL OCCUR WITH THE STRONGEST THUNDERSTORMS. OTHERWISE...A GRADUAL
COOLING TREND WILL OCCUR THROUGH FRIDAY ALONG WITH NORMAL DIURNAL
WIND TRENDS.
&&
.CLIMATE...THE FORECAST HIGH TEMPERATURE TODAY FOR THE TUCSON
INTERNATIONAL AIRPORT IS 110 DEGREES. NOT ONLY WILL THIS TEMPERATURE
SET A NEW DAILY RECORD FOR AUGUST 13TH BREAKING THE OLD RECORD OF
106 DEGREES WHICH OCCURRED IN 1996/1194/1962...IT WOULD ALSO BE THE
FIRST BACK-TO-BACK 109 OR GREATER DURING AUGUST SINCE 1994 WHEN IT
OCCURRED THREE STRAIGHT DAYS (2ND-4TH). ALSO...TODAY WILL BE 8
STRAIGHT DAYS WITH A HIGH OF 105 DEGREES OR WARMER IN TUCSON...
WHICH IS 2 DAYS SHY OF THE AUGUST RECORD OF DAYS THAT OCCURRED IN
1995 (1ST-10TH).
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 6 PM MST THIS EVENING FOR AZZ501-502-504-505.
$$
AREA FORECAST DISCUSSION
NWS TUCSON AZ
930 AM MST MON AUG 13 2012
.SYNOPSIS...EXPECT HOT DAYTIME TEMPERATURES TODAY AND TUESDAY WITH
RECORD OR NEAR RECORD HIGHS IN SOME LOCATIONS. STILL ENOUGH MOISTURE
FOR ISOLATED THUNDERSTORMS TODAY. SCATTERED MAINLY AFTERNOON AND
EVENING THUNDERSTORMS WILL THEN OCCUR FOR THE REMAINDER OF THE WEEK
AS MOISTURE INCREASES ACROSS THE AREA.
&&
.DISCUSSION...KEMX WSR-88D DETECTED ISOLATED 30-50 DBZ ECHOES MOVING
NWWD ACROSS NRN CENTRAL PIMA COUNTY AND SOUTH CENTRAL PINAL COUNTY
AT 1605Z. THE REST OF SE AZ WAS VOID OF PRECIP ECHOES AT THIS TIME.
DEWPOINTS VALID 16Z GENERALLY RANGED FROM THE UPPER 40S-50S F...AND
THESE TEMPS WERE NEARLY 5-10 DEGS F LOWER VERSUS 24 HOURS AGO.
13/12Z KTWC SOUNDING PRECIP WATER VALUE WAS SIMILAR TO 24 HOURS
AGO...AND DEPICTED A VERY DRY SURFACE-700 MB LAYER. 13/12Z UPPER AIR
PLOTS INDICATED 594 DM HIGH CENTERED OVER CENTRAL NEW MEXICO AND
BROAD TROUGH WAS OVER THE ERN CONUS. LIGHT SELY/SLY FLOW PREVAILED
ABOVE 700 MB ACROSS SE AZ.
OUTFLOW BOUNDARY FROM SHOWERS/TSTMS THAT OCCURRED LAST NIGHT MOSTLY
ACROSS ERN NEW MEXICO WAS ADVANCING WWD ACROSS CENTRAL PIMA COUNTY
AT THIS TIME. THE AFOREMENTIONED ISOLATED SHOWERS/TSTMS WERE
GENERATED ALONG THIS BOUNDARY WHICH EXTENDING FURTHER NWD INTO
CENTRAL AZ.
FORECAST CHALLENGE FOR LATER TODAY IS MAINLY REGARDING SHOWER/TSTM
DEVELOPMENT AND EVENTUAL EVOLUTION. 13/13Z RUC HRRR FAVORS SHOWERS/
TSTMS TO OCCUR ACROSS WRN/CENTRAL PIMA COUNTY AND SRN PINAL COUNTY
THRU 19Z. SHOWERS/TSTMS TO THEN DEVELOP EARLY THIS AFTERNOON ACROSS
THE MOUNTAINS EXTENDING FROM SWRN GRAHAM COUNTY-ERN PIMA COUNTY-
SANTA CRUZ COUNTY.
GIVEN THE VERY DRY NEAR-SURFACE ENVIRONMENT AND STRONG DAYTIME
HEATING...MAIN CONCERN IS WITH REGARD TO STRONG DOWNBURSTS AND AN
INCREASED POTENTIAL FOR DAMAGING WIND GUSTS. HAVE NOTED A DOWNTREND
VIA THE 13/13Z RUC HRRR REGARDING SHOWERS/TSTMS LATER THIS AFTERNOON
INTO THIS EVENING.
AT ANY RATE...HAVE OPTED FOR A SPECIAL 18Z KTWC SOUNDING. FOR NOW...
NO ADJUSTMENTS REGARDING THE INHERITED OFFICIAL FORECASTS FOR THE
REST OF TODAY. THE UPSHOT...ISOLATED-SCATTERED SHOWERS/TSTMS THIS
AFTERNOON GENERALLY FROM TUCSON EWD/SWD...THEN SCATTERED SHOWERS/
TSTMS THIS EVENING EXCEPT IN WRN PIMA COUNTY WHERE PRECIP-FREE
CONDITIONS SHOULD CONTINUE.
ALSO...HEAT ADVISORY IS IN EFFECT FROM 1 PM THIS AFTERNOON TO 6 PM
MST THIS EVENING FOR PIMA COUNTY AND SOUTH CENTRAL PINAL COUNTY.
&&
.PREV DISCUSSION...FOR THE REMAINDER OF THE WEEK...WILL SEE A
GRADUAL INCREASE IN MOISTURE ACROSS SOUTHEAST ARIZONA. TROPICAL
STORM HECTOR NO LONGER WILL BE AN INFLUENCE FOR THE AREA. HOWEVER IT
DID INCREASE MOISTURE OVER THE SOUTHERN PARTS OF THE GULF OF
CALIFORNIA ON SUNDAY. THE GULF REMAINS VERY MOIST WITH PW VALUES
OVER 1.50". WILL SEE MORE THUNDERSTORM COMPLEXES DEVELOP OVER SONORA
MEXICO...SENDING LOW LEVEL OUTFLOWS AND ITS MOISTURE NORTH ACROSS
SOUTHERN ARIZONA AND ALSO PUSHING OUTFLOWS INTO THE GULF WITH
RESULTANT INCREASE IN LOW LEVEL MOISTURE INTO THE LOWER DESERTS.
DIDN`T MAKE MANY CHANGES TO THE INHERITED FORECAST AS IT HAD A VERY
GOOD HANDLE ON THE TRENDS FOR THE WEEK. WILL THERE BE DAILY CHANGES.
SURE...BUT OVERALL THE FORECAST LOOKS JUST FINE.
ALTHOUGH TUESDAY WILL BE A FEW DEGREES COOLER THAN TODAY...IT WILL
STILL BE PRETTY HOT WITH A FEW DAILY RECORD FALLING. THEN LOOK FOR
COOLER TEMPERATURES FOR THE REMAINDER OF THE WORK WEEK.
&&
.AVIATION...ISOLD-SCT TSRA/SHRA INTO THIS EVENING THEN A SLIGHT
CHANCE OF -TSRA/-SHRA EAST OF KTUS 06Z-12Z TUESDAY. OTHERWISE...VFR
CONDITIONS AND SURFACE WIND GENERALLY LESS THAN 10 KTS THRU EARLY
TUESDAY MORNING OR 14/12Z. AVIATION DISCUSSION NOT UPDATED FOR
TAF AMENDMENTS.
&&
.FIRE WEATHER...THUNDERSTORM CHANCES WILL GRADUALLY INCREASE THIS
WEEK AS DEEPER MOISTURE RETURNS TO THE AREA. OTHERWISE...EXPECT
NORMAL DIURNAL WIND TRENDS THIS WEEK.
&&
.CLIMATE...THE FORECAST HIGH TODAY FOR THE TUCSON AIRPORT IS 110.
NOT ONLY WILL THIS SET A NEW DAILY RECORD FOR AUGUST 13TH BREAKING
THE OLD RECORD OF 106 DEGREES WHICH OCCURRED IN 1996/1194/1962...IT
WOULD ALSO BE THE FIRST BACK-TO-BACK 109 OR GREATER DURING AUGUST
SINCE 1994 WHEN IT OCCURRED THREE STRAIGHT DAYS (2ND-4TH). ALSO
TODAY WOULD BE 8 STRAIGHT DAYS WITH A HIGH OF 105 OR GREATER IN
TUCSON...WHICH IS TWO DAYS SHY OF THE AUGUST RECORD OF DAYS WHICH
OCCURRED IN 1995 (1ST-10TH).
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY TODAY FROM 1 PM TO 6 PM MST FOR AZZ501-502-504-505.
$$
WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS TUCSON AZ
645 AM MST MON AUG 13 2012
.SYNOPSIS...EXPECT HOT DAYTIME TEMPERATURES TODAY AND TUESDAY WITH
RECORD OR NEAR RECORD HIGHS IN SOME LOCATIONS. STILL ENOUGH MOISTURE
FOR ISOLATED THUNDERSTORMS TODAY. SCATTERED MAINLY AFTERNOON AND
EVENING THUNDERSTORMS WILL THEN OCCUR FOR THE REMAINDER OF THE WEEK
AS MOISTURE INCREASES ACROSS THE AREA.
&&
.UPDATE...RAN OUT A QUICK UPDATE TO THE FORECAST FOR THE SPOTTY
SHOWERS THAT ARE AROUND THIS MORNING...BUT DID EMPHASIS BETTER
CHANCES IN WESTERN PIMA COUNTY SINCE THE HRRR HAS BEEN HITTING THIS
AREA WITH MORE LIGHT SHOWERS IN THE PAST 3 HOURLY RUNS. THIS MODEL
DID HIT THE EARLY MORNING SPOTTY SHOWERS THAT MOVED THROUGH AREAS
EAST OF TUCSON. TAKING A LOOK AT THE TUCSON SOUNDING...IT IS A BIT
WARMER AT THE SURFACE THAT IS WAS ON SUNDAY...SO 109 OR 110 LOOKS
PRETTY GOOD.
&&
.DISCUSSION...KIND OF AN INTERESTING DAY ON TAP FOR SOUTHEAST
ARIZONA. FIRST THERE IS A BACK DOOR COLD FRONT AND SEVERAL OUTFLOW
BOUNDARIES MOVING THROUGH SOUTHWEST NEW MEXICO WHICH HAS DEVELOPED
ISOLATED THUNDERSTORMS. LATEST HRRR RUNS INDICATE THAT THERE WILL BE
SOME WEAK SHOWERS...POSSIBLY A THUNDERSTORM...ALONG/NEAR THE AZ/NM
BORDER THIS MORNING. BASED ON WHAT IS CURRENTLY OCCURRING IN SE NEW
MEXICO...WILL UP POPS THIS MORNING ALONG/NEAR THE AZ/NM BORDER. FOR
THE REMAINDER OF TODAY...STILL RATHER DRY WITH PW VALUES AROUND ONE
INCH. STORMS FOR THE MOST PART WILL BE NEAR THE HIGHER TERRAIN. IF A
FEW DO MOVE INTO THE VALLEYS...THE COULD BE SEVERE DUE TO A VERY HOT
BOUNDARY LAYER. THE OTHER STORY FOR TODAY WILL BE THE CONTINUE VERY
HOT TEMPERATURES FOR MID AUGUST. HIGHS TODAY WILL BE SIMILAR TO WHAT
OCCURRED SUNDAY WITH HEAT ADVISORY IN EFFECT FOR THE LOWER
ELEVATIONS OF PIMA AND PINAL COUNTIES.
FOR THE REMAINDER OF THE WEEK...WILL SEE A GRADUAL INCREASE IN
MOISTURE ACROSS SOUTHEAST ARIZONA. TROPICAL STORM HECTOR NO LONGER
WILL BE AN INFLUENCE FOR THE AREA. HOWEVER IT DID INCREASE MOISTURE
OVER THE SOUTHERN PARTS OF THE GULF OF CALIFORNIA ON SUNDAY. THE
GULF REMAINS VERY MOIST WITH PW VALUES OVER 1.50". WILL SEE MORE
THUNDERSTORM COMPLEXES DEVELOP OVER SONORA MEXICO...SENDING LOW
LEVEL OUTFLOWS AND ITS MOISTURE NORTH ACROSS SOUTHERN ARIZONA AND
ALSO PUSHING OUTFLOWS INTO THE GULF WITH RESULTANT INCREASE IN LOW
LEVEL MOISTURE INTO THE LOWER DESERTS. DIDN`T MAKE MANY CHANGES TO
THE INHERITED FORECAST AS IT HAD A VERY GOOD HANDLE ON THE TRENDS
FOR THE WEEK. WILL THERE BE DAILY CHANGES. SURE...BUT OVERALL THE
FORECAST LOOKS JUST FINE.
ALTHOUGH TUESDAY WILL BE A FEW DEGREES COOLER THAN TODAY...IT WILL
STILL BE PRETTY HOT WITH A FEW DAILY RECORD FALLING. THEN LOOK FOR
COOLER TEMPERATURES FOR THE REMAINDER OF THE WORK WEEK.
&&
.AVIATION...ISOLD-SCT TSRA/SHRA MAINLY FROM KTUS EWD/SWD INTO THIS
EVENING. OTHERWISE...VFR CONDITIONS AND SURFACE WIND GENERALLY LESS
THAN 10 KTS THRU MIDNIGHT OR 14/07Z. AVIATION DISCUSSION NOT UPDATED
FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...THUNDERSTORM CHANCES WILL GRADUALLY INCREASE THIS
WEEK AS DEEPER MOISTURE RETURNS TO THE AREA. OTHERWISE...EXPECT
NORMAL DIURNAL WIND TRENDS THIS WEEK.
&&
.CLIMATE...THE FORECAST HIGH TODAY FOR THE TUCSON AIRPORT IS 110.
NOT ONLY WILL THIS SET A NEW DAILY RECORD FOR AUGUST 13TH BREAKING
THE OLD RECORD OF 106 DEGREES WHICH OCCURRED IN 1996/1194/1962...IT
WOULD ALSO BE THE FIRST BACK-TO-BACK 109 OR GREATER DURING AUGUST
SINCE 1994 WHEN IT OCCURRED THREE STRAIGHT DAYS (2ND-4TH). ALSO
TODAY WOULD BE 8 STRAIGHT DAYS WITH A HIGH OF 105 OR GREATER IN
TUCSON...WHICH IS TWO DAYS SHY OF THE AUGUST RECORD OF DAYS WHICH
OCCURRED IN 1995 (1ST-10TH).
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY TODAY FROM 1 PM TO 6 PM MST FOR AZZ501-502-504-505.
$$
WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS TUCSON AZ
222 AM MST MON AUG 13 2012
.SYNOPSIS...EXPECT HOT DAYTIME TEMPERATURES TODAY AND TUESDAY WITH
RECORD OR NEAR RECORD HIGHS IN SOME LOCATIONS. STILL ENOUGH MOISTURE
FOR ISOLATED THUNDERSTORMS TODAY. SCATTERED MAINLY AFTERNOON AND
EVENING THUNDERSTORMS WILL THEN OCCUR FOR THE REMAINDER OF THE WEEK
AS MOISTURE INCREASES ACROSS THE AREA.
&&
.DISCUSSION...KIND OF AN INTERESTING DAY ON TAP FOR SOUTHEAST
ARIZONA. FIRST THERE IS A BACK DOOR COLD FRONT AND SEVERAL OUTFLOW
BOUNDARIES MOVING THROUGH SOUTHWEST NEW MEXICO WHICH HAS DEVELOPED
ISOLATED THUNDERSTORMS. LATEST HRRR RUNS INDICATE THAT THERE WILL BE
SOME WEAK SHOWERS...POSSIBLY A THUNDERSTORM...ALONG/NEAR THE AZ/NM
BORDER THIS MORNING. BASED ON WHAT IS CURRENTLY OCCURRING IN SE NEW
MEXICO...WILL UP POPS THIS MORNING ALONG/NEAR THE AZ/NM BORDER. FOR
THE REMAINDER OF TODAY...STILL RATHER DRY WITH PW VALUES AROUND ONE
INCH. STORMS FOR THE MOST PART WILL BE NEAR THE HIGHER TERRAIN. IF A
FEW DO MOVE INTO THE VALLEYS...THE COULD BE SEVERE DUE TO A VERY HOT
BOUNDARY LAYER. THE OTHER STORY FOR TODAY WILL BE THE CONTINUE VERY
HOT TEMPERATURES FOR MID AUGUST. HIGHS TODAY WILL BE SIMILAR TO WHAT
OCCURRED SUNDAY WITH HEAT ADVISORY IN EFFECT FOR THE LOWER
ELEVATIONS OF PIMA AND PINAL COUNTIES.
FOR THE REMAINDER OF THE WEEK...WILL SEE A GRADUAL INCREASE IN
MOISTURE ACROSS SOUTHEAST ARIZONA. TROPICAL STORM HECTOR NO LONGER
WILL BE AN INFLUENCE FOR THE AREA. HOWEVER IT DID INCREASE MOISTURE
OVER THE SOUTHERN PARTS OF THE GULF OF CALIFORNIA ON SUNDAY. THE
GULF REMAINS VERY MOIST WITH PW VALUES OVER 1.50". WILL SEE MORE
THUNDERSTORM COMPLEXES DEVELOP OVER SONORA MEXICO...SENDING LOW
LEVEL OUTFLOWS AND ITS MOISTURE NORTH ACROSS SOUTHERN ARIZONA AND
ALSO PUSHING OUTFLOWS INTO THE GULF WITH RESULTANT INCREASE IN LOW
LEVEL MOISTURE INTO THE LOWER DESERTS. DIDN`T MAKE MANY CHANGES TO
THE INHERITED FORECAST AS IT HAD A VERY GOOD HANDLE ON THE TRENDS
FOR THE WEEK. WILL THERE BE DAILY CHANGES. SURE...BUT OVERALL THE
FORECAST LOOKS JUST FINE.
ALTHOUGH TUESDAY WILL BE A FEW DEGREES COOLER THAN TODAY...IT WILL
STILL BE PRETTY HOT WITH A FEW DAILY RECORD FALLING. THEN LOOK FOR
COOLER TEMPERATURES FOR THE REMAINDER OF THE WORK WEEK.
&&
.AVIATION...ISOLD-SCT TSRA/SHRA MAINLY FROM KTUS EWD/SWD INTO THIS
EVENING. OTHERWISE...VFR CONDITIONS AND SURFACE WIND GENERALLY LESS
THAN 10 KTS THRU MIDNIGHT OR 14/07Z. AVIATION DISCUSSION NOT UPDATED
FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...THUNDERSTORM CHANCES WILL GRADUALLY INCREASE THIS
WEEK AS DEEPER MOISTURE RETURNS TO THE AREA. OTHERWISE...EXPECT
NORMAL DIURNAL WIND TRENDS THIS WEEK.
&&
.CLIMATE...THE FORECAST HIGH TODAY FOR THE TUCSON AIRPORT IS 110.
NOT ONLY WILL THIS SET A NEW DAILY RECORD FOR AUGUST 13TH BREAKING
THE OLD RECORD OF 106 DEGREES WHICH OCCURRED IN 1996/1194/1962...IT
WOULD ALSO BE THE FIRST BACK-TO-BACK 109 OR GREATER DURING AUGUST
SINCE 1994 WHEN IT OCCURRED THREE STRAIGHT DAYS (2ND-4TH). ALSO
TODAY WOULD BE 8 STRAIGHT DAYS WITH A HIGH OF 105 OR GREATER IN
TUCSON...WHICH IS TWO DAYS SHY OF THE AUGUST RECORD OF DAYS WHICH
OCCURRED IN 1995 (1ST-10TH).
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY TODAY FROM 1 PM TO 6 PM MST FOR AZZ501-502-504-505.
$$
WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS PUEBLO CO
318 PM MDT MON AUG 13 2012
.SHORT TERM...
(TONIGHT AND TOMORROW)
...SCATTERED STORMS FOR EVERYONE NEXT 6-9 HOURS OR SO...
CURRENTLY...
WATER VAPOR AT 2 PM SHOWS A HEALTHY DISTURBANCE UP IN WYOMING AND IT
WAS MOVING EAST SOUTHEAST TOWARDS THE REGION. A RATHER LARGE AREA OF
RAIN WAS NOTED OVER THE GENERAL NW SXTNS OF THE STATE OF CO...WITH
QUITE A FEW SHOWER SURROUNDING THIS AREA OF RAIN. A COUPLE OF
VORTICES WERE IMPLIED IN THE RAIN SHIELD (ORIENTATION OF CURVED
RAINSHIELD ON RADAR IMGY)...WITH ONE NW OF LARAMIE AND ANOTHER
ENTERING NW CO.
REST OF TODAY AND INTO TONIGHT...
SHOWERS AND STORMS WILL CONTINUE TO INCREASE IN COVERAGE OVER THE
REGION...AND THERE IS A PRETTY GOOD CHANCE NEARLY ALL OF US WILL SEE
SOME RAIN DURING THE NEXT 9 HOURS OR SO. PRECIP WAS ALREADY
DEVELOPING ON THE PLAINS AS I WRITE (2 PM) AND HRRR FCST THIS TO
EXPAND AND MOVE TO THE EAST-SOUTHEAST. EVEN GFS HAS A LARGE BULLSEYE
OF PRECIP OVER THE FAR SE PLAINS LATER TODAY. AS FOR THE BURN
SCAR...LATEST HI RES GUIDANCE SHOWS THE BEST CHANCE BETWEEN 3 AND 5
PM. LOCALLY HEAVY RAIN COULD OCCUR BUT I AM NOT ALL THAT CONFIDENT
AS IT MAY BE TOO STABLE FOR ANY HEAVIER RAIN OVER THE SCAR...HOWEVER
I AM PRETTY CERTAIN THEY WILL GET MORE PRECIP TODAY. PRECIP OVER THE
REST OF THE MTNS WILL CONTINUE TO BLOSSOM AS THE AFTERNOON
PROGRESSES.
SHOWERS AND STORMS WILL BE ONGOING ACROSS THE PLAINS THIS EVENING.
ACTIVITY OVER THE MTNS WILL STILL BE ONGOING...BUT WILL BE ON A
GRADUAL DOWNWARD TREND AS THE EVENING PROGRESSES. I WOULD EXPECT BY
MID EVENING THE HEAVIEST STORMS WILL BE OVER THE EASTERN
PLAINS...ESPECIALLY THE FAR E PLAINS. A FEW STRONGER STORMS WILL BE
POSSIBLE BUT WILL ONLY BE MARGINALLY SEVERE AT BEST GIVEN THE
LIMITED CAPE/SHEAR FIELDS CURRENTLY IN PLACE.
BY MIDNIGHT...ISOLATED PRECIP MAY BE OVER THE MTNS WITH PRECIP OVER
THE FAR E PLAIN MOVING OUT OF THE STATE.
TOMORROW...
RATHER STABLE AIRMASS WILL LIKELY BE OVER THE PLAINS AND DO NOT
EXPECT ANY PRECIP. THE ONLY EXCEPTION MAY BE THAT PART OF THE PLAINS
ABOVE 6000 FEET WHICH MAY SEE A SHOWER LATE IN THE DAY. THE MTNS
WILL CONTINUE TO SEE SCTD COVERAGE..ESPECIALLY ALONG THE CONTDVD. I
DID KNOCK DOWN TEMPS A FEW DEGREES AS IT WILL LIKELY BE A BIT COOLER
TOMORROW THAN EARLIER ADVERTISED.
.LONG TERM...
(TUESDAY NIGHT THROUGH MONDAY)
TUESDAY NIGHT THROUGH WEDNESDAY AFTERNOON...AS THE UPPER WAVE
DEPARTS AND THE RIDGE CONTINUES TO BREAK DOWN...SUBSIDENCE SHOULD
RESTRICT CONVECTION TO THE MTS THROUGH THE EVE...THEN THE TYPICAL
ISOLATED TO LOW SCATTERED CONVECTION FOR THE MTS WED AFTN. A WARM
AND BREEZY DAY IS ON TAP FOR WED...AHEAD OF THE NEXT INCOMING SFC
FRONT.
WEDNESDAY NIGHT THROUGH FRIDAY...MODELS INDICATE A RATHER STRONG
SHORTWAVE DROPS DOWN OUT OF CANADA AND ACROSS THE NORTHERN PLAINS ON
WED...PUSHING A SFC FRONT DOWN INTO COLORADO WED EVE. NAM MODEL
SHOWS A PRE-FRONTAL NORTHERLY PUSH THROUGH THE DAY WED...WITH THE
TRUE SFC FRONT CROSSING THE PALMER DVD RIGHT BETWEEN 00Z AND 06Z.
SO...NORTHERLY WINDS LATE WED NIGHT INTO THU MORNING...WITH WINDS
SWINGING AROUND TO THE EAST BY THU AFTN. PCPN SHOULD BE FAIRLY
WIDESPREAD LATE WED NIGHT AND LINGER INTO THE EARLY MORNING HRS OF
THU...THEN FIRE UP AGAIN QUICKLY ON THU WITH UPSLOPE SHOVING THE
MOISTURE UP AGAINST THE SOUTHERN FRONT RANGE. PCPN WILL TAPPER OFF
FROM N TO S THU EVE...THEN A LITTLE LESS COVERAGE IS THEN FORECAST
FOR FRI. MAX TEMPS ON THU ARE CURRENTLY FORECAST TO WARM INTO THE
70S TO NEAR 80 F FOR THE PLAINS...BUT WITH THE EXPECTED CLOUD COVER
THIS MAY BE SLIGHTLY TOO WARM...AND WILL HAVE TO REVISIT MAX TEMP
GRIDS AGAIN OVER THE NEXT FEW MODEL RUNS. THE COOL TEMPS SHOULD
CARRY OVER INTO FRI AS THE LLVL COOL AIR AND MOISTURE GRADUALLY
ERODES.
SATURDAY THROUGH MONDAY...UPPER RIDGE STRENGTHENS OVER THE WESTERN
US FOR THE WEEKEND...WITH CONVECTIVE ACTIVITY SLIPPING BACK INTO A
DIURNAL PATTERN WITH MORE ISOLATED COVERAGE TIED TO THE HIGHER
TERRAIN. GFS MODEL IS INDICATING A LOT MORE POSSIBLE PCPN OVER THE
PLAINS...WHICH IS LIKELY A RESULT OF THE RIDGE BREAKING DOWN FASTER
THAN WHAT THE ECMWF SHOWS...SO WILL MAINTAIN THE FORECAST OF DIURNAL
MT CONVECTION AND MAX TEMPS CLIMBING BACK INTO THE 90S FOR THE
PLAINS AND 80S FOR THE HIGH VALLEYS. MOORE
&&
.AVIATION...
ALL TAFS SITES WILL SEE STORMS TODAY. A FEW SHOWERS HAVE ALREADY
MOVED ACROSS KALS AND KCOS AS PER RADAR IMGY. WITH THE VORT MAX
MOVING ACROSS THE AREA LATER TODAY AND EARLY THIS EVENING SCATTERED
STORMS WILL MOVE ACROSS THE TAF SITES...WITH THE BEST CHANCE BETWEEN
3 AND 7 PM AT KCOS AND 3 AND 8 PM ACROSS KPUB. SHOWERS WILL MOVE
ACROSS KALS BETWEEN NOW AND 8 PM THIS EVENING. CIGS SHOULD REMAIN
ABOVE MVFR BUT WE MAY SEE BRIEF HVY RAINS WHICH WILL BRING MVFR
CONDITIONS TO THE TAF SITES.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
34/27
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1151 PM EDT TUE AUG 14 2012
.SYNOPSIS...
LOW PRESSURE AND A COMPLEX WEAK FRONTAL SYSTEM SPRAWLED FROM THE
MID ATLANTIC STATES TO OHIO WILL CROSS THE MID ATLANTIC COAST LATE
WEDNESDAY. HIGH PRESSURE SHOULD MOVE BACK IN BEHIND THE DEPARTING
SYSTEM THURSDAY. ANOTHER COLD FRONT SLOWLY MOVES THROUGH LATER ON
FRIDAY INTO SATURDAY BEFORE HIGH PRESSURE CAN POSSIBLY BUILD BACK
IN LATE SUNDAY AND MONDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THE ACTIVITY ACROSS MOVING INTO THE LEHIGH VALLEY AND NORTHEAST
MARYLAND IS STARTING TO WANE AS THE IT IS NOW FUELED MAINLY BY IN
SITU INSTABILITY. THE BEST SHEAR WILL PASS SOUTH OF THE AREA
DURING THE NEXT THREE HOURS...AND MID LEVEL LAPSE RATES ARE
MARGINAL AT BEST. FOR NOW...THE MENTION OF HEAVY RAIN (AS THE
CONVECTION SITS IN AN AREA OF 1.70 INCH PRECIPITABLE
WATER)...GUSTY WINDS AND LIGHTNING WILL BE LEFT IN THE FORECAST
(THOUGH LOCALIZED FLOODING MAY BE THE BIGGEST THREAT.
THE LATEST HRRR WEAKENS THE ACTIVITY AS IT MOVES TO THE NORTHEAST...
INTO LESS UNSTABLE AIR. THE LOW LEVELS SHOULD TEND TO STABILIZE
AHEAD OF IT...SO THIS MAKES SOME SENSE. THE OVERNIGHT SHOWER AND
THUNDERSTORM FORECAST WILL BE REVISED A BIT TO FIT THE ABOVE
THINKING.
THE CLOUD COVER FORECAST WILL ALSO HAVE TO BE ADJUSTED TO ACCOUNT
FOR SOME STRATUS ACROSS PORTIONS OF WEST CENTRAL NEW JERSEY. IT IS
NOT CLEAR AT THIS POINT HOW WIDESPREAD THE STRATUS WILL GET...BUT
IT MAY END UP SPREADING INTO EASTERN PENNSYLVANIA DURING THE NEXT
THREE HOURS OR SO. THE STRATUS SHOULD TEND TO LESS THEN FOG
THREAT...BUT THIS MAY END UP BEING DICTATED BY WHERE THE RAIN
FALLS EARLY THIS MORNING IN A LIGHT BOUNDARY FLOW.
NO SIGNIFICANT CHANGES WERE MADE TO THE TEMPERATURE AND WIND
FORECASTS FOR THE REST OF THE NIGHT.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
THE UPPER TROUGH WILL BE CROSSING THE AREA WED. MOISTURE WILL REMAIN
RATHER HIGH AND WITH THE FRONT AND WEAK LOW NEARBY...THERE REMAINS
THE CHC FOR SCATTERED SHOWERS/TSTMS. WE HAVE KEPT THE CHC FOR PRECIP
MOSTLY IN THE CHC RANGE FOR NOW. SPC HAS MOST OF OUR AREA IN A
GENERAL TSTM OUTLOOK...BUT SLGT CHC EXISTS OVER SRN DELAWARE. HIGH
TEMPERATURES WEDNESDAY WILL TOP OUT IN THE LOW 80S ACROSS THE NORTH
AND MID TO UPPER 80S ELSEWHERE.
MORE ML CAPE THAN TODAY AND IT LOOKS LIKE A LITTLE HIGHER TT BUT
SHEAR IS MARGINAL AT BEST.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
A DOWNWARD TREND IN SHOWERY ACTIVITY IS EXPECTED DURING THE
OVERNIGHT HOURS WEDNESDAY AS THE FINAL MID-LEVEL IMPULSE PULLS
THROUGH AND TO OUR NORTHEAST. WEAK MID-LEVEL RIDGING WILL BUILD IN
ALLOWING MID-LEVELS WINDS TO BECOME SOMEWHAT ZONAL OR SLIGHTLY
NORTHWEST ON THURSDAY AND FRIDAY. SURFACE HIGH PRESSURE WILL MOVE
ACROSS THE REGION ON THURSDAY INTO EARLY FRIDAY AND KEEP OUR
SENSIBLE WEATHER RATHER QUIET. SHOULD HAVE AMPLE SUNSHINE ON
THURSDAY TO ALLOW TEMPERATURES TO CLIMB BACK TO AROUND SEASONAL OR
SLIGHTLY ABOVE.
HIGH SLIDES OFF THE COAST EARLY ON FRIDAY WITH A RETURN FLOW SETTING
UP. MORE MOISTURE AND WARMER TEMPERATURES ARE ADVECTED BACK INTO THE
REGION JUST IN TIME FOR AN APPROACHING MID-LEVEL WAVE AND SURFACE
COLD FRONT TO MOVE THROUGH. COULD SEE A LEE SIDE TROUGH FORM AND
MOVE THROUGH OUR SOUTHERN ZONES DURING THE AFTERNOON HOURS AND WITH
AMPLE SURFACE BASED INSTABILITY CONVECTION IS LIKELY, ALTHOUGH THIS
ALL DEPENDENT ON THE TIMING OF THE AFOREMENTIONED COLD FRONT AND LEE
SIDE TROUGH. MODEL TIMING ON THE FRONTAL PASSAGE HAS NOT BEEN GOOD
WITH SOME BRINGING IT THROUGH FRIDAY EVENING AND SOME NOT CLEARING
THE REGION UNTIL SUNDAY MORNING. THOUGH THE FLOW IN THE MID-LEVELS
DOES NOT LOOK AS FORCEFUL AS IT DID YESTERDAY, WITH A MORE
MERIDIONAL REGIME IN PLACE, A SLOWER TIMING LOOKS MORE LIKELY. THIS
WOULD INTRODUCE HIGHER CHANCES OF SHOWERS AND THUNDERSTORMS BY
FRIDAY EVENING/NIGHT SPREADING INTO SATURDAY EVENING. ANOTHER WAVE
OF LOW PRESSURE FORMS ALONG THE FRONTAL BOUNDARY AND SLOWS ITS
EASTWARD MOVEMENT EVEN MORE. THAT BEING SAID DECIDED TO KEEP THE
CHANCE POPS IN FOR MUCH OF SATURDAY.
FINALLY WE SHOULD BE ABLE TO KICK THE FRONT FAR ENOUGH TO THE EAST
BY LATE SATURDAY OR SUNDAY MORNING AND DRY OUT. MID-LEVEL TROUGHING
WILL REMAIN ACROSS THE REGION FOR THE DURATION OF THE LONG TERM AND
THIS COULD KEEP US RATHER UNSETTLED FOR THE START OF THE NEW WORK
WEEK. LOOKS LIKE OUR NEXT SHOT AT SEEING PRECIPITATION IS ON TUESDAY
AS ANOTHER PIECE OF ENERGY IN THE MID-LEVELS DIVES INTO THE BASE OF
THE EAST COAST TROUGH AND THEN MOVES UP TO THE NORTHEAST WITHIN THE
SOUTHWEST FLOW ALOFT.
TEMPERATURES THROUGH THE LONG TERM WILL BE NEAR NORMAL TO SLIGHTLY
ABOVE NORMAL BY THE END OF THE WEEK. ONCE THE MID-LEVEL TROUGH
RE-ESTABLISHES ITSELF NEARBY AND THE FRONTAL SYSTEM CLOSE BY, WE
COULD SEE AMPLE CLOUD COVER ALLOWING FOR SLIGHTLY BELOW NORMAL
TEMPERATURES SATURDAY THROUGH TUESDAY.
&&
.AVIATION /04Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
REST OF TONIGHT...VFR SCT-BKN CLOUDS AOA 4000 FT. BUT AREAS OF IFR
ST/FOG POSSIBLE...ESP E PA AND NNJ. CHC OF A SHOWER OR TSTM
OVERNIGHT. LIGHT WIND.
WEDNESDAY...VFR SCT-BKN CLDS AOA 4000 FT AFTER ANY EARLY MORNING
ST/FOG/HAZE/ THINS OUT-DISSIPATES. LIGHT S WIND BECOMES LIGHT WNW
LATE.
SCT-BKN SHOWERS AND EMBEDDED TSTMS EXPECTED IN THE AFTN...A COUPLE OF
WHICH SHOULD PRODUCE VERY HEAVY RAIN...FQT LIGHTING AND GUSTY WINDS.
FOR NOW THE TAFS HAVE VCSH AND A PROB30 FOR TSTM IN A SMALL TIME
FRAME WED AFTN WHICH WILL NEED ADJUSTMENT SINCE THE WINDOW OF
OPPORTUNITY LOOKS LARGER.
OUTLOOK...
WEDNESDAY NIGHT THROUGH FRIDAY...MAINLY VFR WITH LIGHT WEST
WINDS. COULD BE SOME LOCAL MVFR VSBYS EARLY THURSDAY MORNING.
FRIDAY NIGHT THROUGH SATURDAY...ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS POSSIBLE. VFR CONDITIONS EXPECTED.
SATURDAY NIGHT THROUGH SUNDAY...VFR EXPECTED. COULD BE A FEW
LINGERING SHOWERS EARLY SATURDAY NIGHT.
&&
.MARINE...
NO SCA THROUGH WEDNESDAY. MAINLY S-SE WIND 10-15 KTS TONIGHT BECOME S-SW
WEDNESDAY AND THEN W LATE IN THE DAY. G WINDS NEAR ANY TSTMS.
OUTLOOK...
SUB-ADVISORY CONDITIONS ARE EXPECTED ACROSS THE WATERS
THROUGH THE WEEKEND. HIGH PRESSURE WILL BUILD IN ON THURSDAY
PROVIDING TRANQUIL CONDITIONS. WINDS TURN TO THE SOUTH ON FRIDAY
AND SEAS WILL BEGIN TO CLIMB TO 3 TO 4 FEET FOR A TIME DURING THE
AFTERNOON HOURS...DEPENDING ON HOW LONG WE TRULY KEEP THE
SOUTHERLY FETCH. ANOTHER FRONTAL SYSTEM TRIES TO ENTER FROM THE
WEST EARLY ON SATURDAY PROVIDING MORE SHOWERS AND THUNDERSTORMS.
THIS FRONT SHOULD THEN PUSH OFF TO THE EAST BY LATE IN THE DAY AND
WINDS TURN TOWARDS THE WEST-NORTHWEST.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...DRAG/HEAVENER
NEAR TERM...HAYES
SHORT TERM...DRAG/O`HARA
LONG TERM...HEAVENER
AVIATION...DRAG/HEAVENER
MARINE...DRAG/HEAVENER
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
552 PM EDT MON AUG 13 2012
.UPDATE...
DIFFICULT FORECAST FOR TONIGHT...WITH NONE OF THE MODELS REALLY HAVING
A GOOD HANDLE ON THE CURRENT SHOWER AND THUNDERSTORM ACTIVITY.
HAVE SIGNIFICANTLY UPDATED POPS AND WEATHER GRIDS TO ACCOUNT FOR
CURRENT CONVECTION ASSOCIATED WITH MCS THAT MOVED EASTWARD OUT OF
TN/AL THIS AFTERNOON. LATEST LAPS SHOWING BEST INSTABILITY ALONG
THE GA/AL LINE...WITH AREAS FURTHER EAST FAR MORE STABLE. IN
GENERAL...EXPECT AN OVERALL WEAKENING TREND AS THIS LARGE AREA OF
PRECIPITATION CONTINUES TO MOVE EASTWARD.
WILL BE MAKING PERIODIC UPDATES TO THE FORECAST AS NECESSARY AS
THIS EVENT CONTINUES TO UNFOLD. HAVE GONE AHEAD AND CANCELLED THE
SVR WATCH FOR THE FAR NORTHEAST PORTION OF THE STATE.
31
&&
.PREV DISCUSSION... /ISSUED 308 PM EDT MON AUG 13 2012/
..SEVERE STORMS EXPECTED THROUGH THIS EVENING EXTREME NW GEORGIA...
SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
ALL EYES ON MCS OVER TENNESSEE AND ALABAMA WHICH CONTINUES TO MAKE
STEADY PROGRESS TO THE EAST. NOW HAVE A WATCH UP FOR THE EXTREME
NW CORNER OF THE FORECAST AREA WHERE THERE IS IRONICALLY LITTLE TO
NO INSTABILITY AT THIS TIME. SYSTEM HAS HOWEVER BEEN ABLE TO BRING
ALONG ITS OWN ENHANCED MOISTURE AND INSTABILITY ALTHOUGH ITS
ABILITY TO DO SO AS IT APPROACHES THE FORECAST AREA REMAINS IN
QUESTION. RAP SHORT TERM GUIDANCE DOES SHOW INCREASED INSTABILITY
WITHIN THE NEXT 2 HOURS PUSHING INTO THE NW ZONES BUT ONLY ON THE
ORDER OF 1500 TO 2000 J/KG...MUCH LESS THAN UPSTREAM VALUES WE HAVE
SEEN. SO IN SHORT...EXPECTING SVR POTENTIAL TO INCREASE FOR THE
EXTREME NW AND WESTERN TIER OVER THE NEXT SEVERAL HOURS BUT TRENDS
IN INSTABILITY SUGGEST A LIMITED TIMEFRAME FOR CONVECTIVE
POTENTIAL. ALSO WATCHING DEVELOPING AREA OF DCAPE IN EXCESS OF
1000 J/KG WHICH COULD ALLOW FOR ISOLATED SVR OUTSIDE OF CURRENT
WATCH AREA FROM COLUMBUS UP TO LA GRANGE.
QUESTIONS ALSO SURROUND HOW FAR ACTUAL LINE OF SHOWERS AND STORMS
MAKES IT TO THE EAST. AS MENTIONED...EXPECTING A SHARP INSTABILITY
GRADIENT AND MOMENTUM LOOKS TO ONLY TAKE THIS SYSTEM SO FAR. HRRR
IS DIMINISHING LINE AND THEN GENERATES NEW CONVECTION ALONG ACTUAL
FRONT INTO THE OVERNIGHT HOURS. GIVEN CURRENT TRENDS...WILL EXPAND
POP COVERAGE SLIGHTLY EASTWARD BUT ONLY CARRY LOW END CHANCE POPS
INTO THE OVERNIGHT PERIOD FOR THE ATLANTA METRO AND POINTS NORTH
AND WEST.
BY 12Z...FRONT WILL SAG INTO NORTH GEORGIA WITH DRIER AIR
BEGINNING TO FILTER IN. WILL BE IN LARGE SCALE TROUGH PATTERN BUT
NO NOTABLE SHORTWAVES EMBEDDED IN FLOW UNTIL 00Z. THIS COULD
ENHANCE POPS FIELD BUT PRIMARILY OVER THE SOUTHERN TIER WHERE I
HAVE INCLUDED LIKELY POPS.
DEESE
LONG TERM /WEDNESDAY THROUGH MONDAY/...
NO SIGNIFICANT CHANGES PLANNED.
BDL
MEDIUM RANGE MODELS REMAIN CONSISTENT THROUGH THE EXTENDED
FORECAST PERIOD KEEPING THE EASTERN U.S. UNDER PERSISTENT LONG
WAVE TROUGHING. ALTHOUGH THE LARGE SCALE PATTERN REMAINS FAIRLY
STATIC...THE SMALLER SCALE REMAINS QUITE ACTIVE AS SHORT WAVES
SWING THROUGH THE TROUGH DIGGING OUT OF THE NORTHERN PLAINS INTO
THE OHIO VALLEY. THIS PATTERN KEEPS THE BEST UPPER DYNAMICS NORTH
OF THE REGION...BUT MANAGES TO DRIVE A SERIES OF ASSOCIATED
SURFACE FRONTS THROUGH THE STATE. FIRST SYSTEM IS EXITING AS WE
HEAD INTO THE EXTENDED PERIOD SO ANOTHER SHOT OF MILDER AND FAIRLY
DRY AIR SETTLES IN FOR THE MIDDLE OF THE WEEK. NEXT SYSTEM IS
EXPECTED FOR THE END OF THE WEEK INTO THE WEEKEND. THIS
CORRESPONDS WELL WITH PREVIOUS MODEL RUNS SO THERE ARE NO
SIGNIFICANT CHANGES TO THE PREVIOUS EXTENDED FORECAST THEMES.
20
AVIATION...
18Z UPDATE...
CONTINUING TO WATCH THE ADVANCEMENT OF SQUALL LINE THROUGH
NORTHERN AND CENTRAL ALABAMA WITH NO WEAKENING TREND AS OF YET.
DESPITE THIS...ALL GUIDANCE INDICATES IT WILL BEGIN TO DISSIPATE
BY THE TIME IT REACHES THE AL/GA LINE WITH JUST RESIDUAL SHRA FOR
ATL AND SURROUNDING TERMINALS THROUGH THE OVERNIGHT PERIOD. MUCH
UNCERTAINTY EXISTS WITH THIS ASPECT OF THE FORECAST HOWEVER AND
CHANGES WILL BE HANDLED WITH SUBSEQUENT AMENDMENTS. DO EXPECT LINE
OF TSRA TO DEVELOP ONCE AGAIN MID MORNING ON TUESDAY AND HAVE
INCLUDED PROB30 THROUGH THE EARLY AFTERNOON HOURS.
//ATL CONFIDENCE...18Z UPDATE...
LOW ON CONVECTION POTENTIAL THIS EVENING.
HIGH ON REMAINING ELEMENTS.
DEESE
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 65 90 69 91 / 20 40 20 10
ATLANTA 70 87 71 88 / 60 30 20 10
BLAIRSVILLE 63 83 64 85 / 50 30 20 5
CARTERSVILLE 67 87 68 89 / 70 30 20 5
COLUMBUS 71 90 74 91 / 60 40 20 20
GAINESVILLE 67 87 69 88 / 50 30 20 10
MACON 67 91 72 91 / 20 50 30 20
ROME 67 87 68 89 / 50 30 20 5
PEACHTREE CITY 67 87 69 89 / 60 30 20 10
VIDALIA 70 92 75 92 / 10 60 50 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...41
LONG TERM....31
AVIATION...41
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
308 PM EDT MON AUG 13 2012
...SEVERE STORMS EXPECTED THROUGH THIS EVENING EXTREME NW GEORGIA...
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
ALL EYES ON MCS OVER TENNESSEE AND ALABAMA WHICH CONTINUES TO MAKE
STEADY PROGRESS TO THE EAST. NOW HAVE A WATCH UP FOR THE EXTREME
NW CORNER OF THE FORECAST AREA WHERE THERE IS IRONICALLY LITTLE TO
NO INSTABILITY AT THIS TIME. SYSTEM HAS HOWEVER BEEN ABLE TO BRING
ALONG ITS OWN ENHANCED MOISTURE AND INSTABILITY ALTHOUGH ITS
ABILITY TO DO SO AS IT APPROACHES THE FORECAST AREA REMAINS IN
QUESTION. RAP SHORT TERM GUIDANCE DOES SHOW INCREASED INSTABILITY
WITHIN THE NEXT 2 HOURS PUSHING INTO THE NW ZONES BUT ONLY ON THE
ORDER OF 1500 TO 2000 J/KG...MUCH LESS THAN UPSTREAM VALUES WE HAVE
SEEN. SO IN SHORT...EXPECTING SVR POTENTIAL TO INCREASE FOR THE
EXTREME NW AND WESTERN TIER OVER THE NEXT SEVERAL HOURS BUT TRENDS
IN INSTABILITY SUGGEST A LIMITED TIMEFRAME FOR CONVECTIVE
POTENTIAL. ALSO WATCHING DEVELOPING AREA OF DCAPE IN EXCESS OF
1000 J/KG WHICH COULD ALLOW FOR ISOLATED SVR OUTSIDE OF CURRENT
WATCH AREA FROM COLUMBUS UP TO LA GRANGE.
QUESTIONS ALSO SURROUND HOW FAR ACTUAL LINE OF SHOWERS AND STORMS
MAKES IT TO THE EAST. AS MENTIONED...EXPECTING A SHARP INSTABILITY
GRADIENT AND MOMENTUM LOOKS TO ONLY TAKE THIS SYSTEM SO FAR. HRRR
IS DIMINISHING LINE AND THEN GENERATES NEW CONVECTION ALONG ACTUAL
FRONT INTO THE OVERNIGHT HOURS. GIVEN CURRENT TRENDS...WILL EXPAND
POP COVERAGE SLIGHTLY EASTWARD BUT ONLY CARRY LOW END CHANCE POPS
INTO THE OVERNIGHT PERIOD FOR THE ATLANTA METRO AND POINTS NORTH
AND WEST.
BY 12Z...FRONT WILL SAG INTO NORTH GEORGIA WITH DRIER AIR
BEGINNING TO FILTER IN. WILL BE IN LARGE SCALE TROUGH PATTERN BUT
NO NOTABLE SHORTWAVES EMBEDDED IN FLOW UNTIL 00Z. THIS COULD
ENHANCE POPS FIELD BUT PRIMARILY OVER THE SOUTHERN TIER WHERE I
HAVE INCLUDED LIKELY POPS.
DEESE
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
NO SIGNIFICANT CHANGES PLANNED.
BDL
MEDIUM RANGE MODELS REMAIN CONSISTENT THROUGH THE EXTENDED
FORECAST PERIOD KEEPING THE EASTERN U.S. UNDER PERSISTENT LONG
WAVE TROUGHING. ALTHOUGH THE LARGE SCALE PATTERN REMAINS FAIRLY
STATIC...THE SMALLER SCALE REMAINS QUITE ACTIVE AS SHORT WAVES
SWING THROUGH THE TROUGH DIGGING OUT OF THE NORTHERN PLAINS INTO
THE OHIO VALLEY. THIS PATTERN KEEPS THE BEST UPPER DYNAMICS NORTH
OF THE REGION...BUT MANAGES TO DRIVE A SERIES OF ASSOCIATED
SURFACE FRONTS THROUGH THE STATE. FIRST SYSTEM IS EXITING AS WE
HEAD INTO THE EXTENDED PERIOD SO ANOTHER SHOT OF MILDER AND FAIRLY
DRY AIR SETTLES IN FOR THE MIDDLE OF THE WEEK. NEXT SYSTEM IS
EXPECTED FOR THE END OF THE WEEK INTO THE WEEKEND. THIS
CORRESPONDS WELL WITH PREVIOUS MODEL RUNS SO THERE ARE NO
SIGNIFICANT CHANGES TO THE PREVIOUS EXTENDED FORECAST THEMES.
20
&&
.AVIATION...
18Z UPDATE...
CONTINUING TO WATCH THE ADVANCEMENT OF SQUALL LINE THROUGH
NORTHERN AND CENTRAL ALABAMA WITH NO WEAKENING TREND AS OF YET.
DESPITE THIS...ALL GUIDANCE INDICATES IT WILL BEGIN TO DISSIPATE
BY THE TIME IT REACHES THE AL/GA LINE WITH JUST RESIDUAL SHRA FOR
ATL AND SURROUNDING TERMINALS THROUGH THE OVERNIGHT PERIOD. MUCH
UNCERTAINTY EXISTS WITH THIS ASPECT OF THE FORECAST HOWEVER AND
CHANGES WILL BE HANDLED WITH SUBSEQUENT AMENDMENTS. DO EXPECT LINE
OF TSRA TO DEVELOP ONCE AGAIN MID MORNING ON TUESDAY AND HAVE
INCLUDED PROB30 THROUGH THE EARLY AFTERNOON HOURS.
//ATL CONFIDENCE...18Z UPDATE...
LOW ON CONVECTION POTENTIAL THIS EVENING.
HIGH ON REMAINING ELEMENTS.
DEESE
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 65 90 69 91 / 20 40 20 10
ATLANTA 70 87 71 88 / 30 30 20 10
BLAIRSVILLE 63 83 64 85 / 30 30 20 5
CARTERSVILLE 67 87 68 89 / 30 30 20 5
COLUMBUS 71 90 74 91 / 40 40 20 20
GAINESVILLE 67 87 69 88 / 30 30 20 10
MACON 67 91 72 91 / 20 50 30 20
ROME 67 87 68 89 / 60 20 20 5
PEACHTREE CITY 67 87 69 89 / 30 30 20 10
VIDALIA 70 92 75 92 / 10 60 50 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
SEVERE THUNDERSTORM WATCH UNTIL 9 PM EDT THIS EVENING FOR THE
FOLLOWING ZONES: CATOOSA...CHATTOOGA...DADE...FLOYD...WALKER.
&&
$$
SHORT TERM...DEESE
LONG TERM....BDL
AVIATION...DEESE
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1142 PM CDT SUN AUG 12 2012
.DISCUSSION...
ISSUED 910 PM CDT SUN AUG 12 2012
EARLIER SPRINKLES HAVE EXITED THE AREA. NEXT ROUND OF SHOWERS HAS
BEEN INCREASING NORTHWEST OF THE ILLINOIS RIVER OVER THE LAST HOUR
OR TWO...WITH SOME EMBEDDED THUNDERSTORMS MAINLY IN AREAS NEAR AND
NORTHWEST OF QUINCY. BULK OF THE RAIN HAS BEEN ALONG AND NORTH OF
A WARM FRONT/TROUGH THAT EXTENDS ACROSS NORTHERN MISSOURI TO NEAR
BLOOMINGTON. LATEST HRRR GUIDANCE HAS BEEN DOING A REASONABLE JOB
WITH THE COVERAGE OF THESE SHOWERS...AND SHOWS THE HIGHEST RAIN
CHANCES OVER THE NORTHERN HALF OF THE CWA OVER THE NEXT SEVERAL
HOURS. SOUTH OF THE BOUNDARY...SCATTERED SHOWERS AND STORMS HAVE
BEEN DEVELOPING AHEAD OF A COLD FRONT WHICH EXTENDS SOUTHWEST TO
NORTHEAST ACROSS MISSOURI. IT WILL LIKELY TAKE UNTIL AFTER
MIDNIGHT BEFORE THESE REACH THE SOUTHEAST CWA. THE SHOWERS WILL
PROBABLY BE EXITING THE SOUTHEAST CWA SHORTLY BEFORE SUNRISE... AS
SOME DRY SLOTTING TAKES PLACE OVER WEST CENTRAL ILLINOIS.
UPDATED ZONES/GRIDS HAVE BEEN SENT.
GEELHART
&&
.AVIATION...
ISSUED 1140 PM CDT SUN AUG 12 2012
MAIN CONCERN FOR THIS TAF PERIOD WILL BE PINNING DOWN CONVECTION
TIMING/ENDING AT THE TERMINALS...AS LOW PRESSURE SYSTEM EDGES TO
THE EAST AND DRAGS A COLD FRONT ACROSS THE AREA ON MONDAY. CURRENT
RADAR TRENDS SHOW AN AREA OF SHOWERS AND THUNDERSTORMS STEADILY
PROGRESSING EASTWARD. LATEST MODEL RUNS SHOW FAIRLY WIDESPREAD
SHOWERS PERSISTING THROUGH AROUND 12Z AT PIA...AND AROUND 14Z AT
CMI. CIGS WILL ALSO BE A CONCERN...AS MODEL SOUNDINGS HINT THAT
SOME MVFR CIGS MIGHT DEVELOP LATE MORNING INTO THE AFTERNOON AND
HANG AROUND FOR MOST OF THE DAY. CMI/BMI/DEC MIGHT SEE THESE
CONDITIONS CONTINUE INTO THE OVERNIGHT AS THEY REMAIN IN CLOSER
PROXIMITY TO THE LOW.
WINDS WILL GENERALLY BE LIGHT OUT OF THE EAST/SOUTHEAST...AND THEN
BECOME NORTHERLY AND PICK UP SPEED AFTER FRONTAL PASSAGE.
ECT/GEELHART
&&
.PREV DISCUSSION...
ISSUED 259 PM CDT SUN AUG 12 2012
ANOTHER RELATIVELY COOL DAY ACROSS MOST OF CENTRAL ILLINOIS...
WHILE SOUTHEAST ILLINOIS IS WARMER DUE TO RECEIVING MORE SUN
BEFORE THE CLOUDS MOVED IN. THESE CLOUDS ARE ASSOCIATED WITH AN
APPROACHING CLIPPER TYPE SYSTEM...SOMEWHAT UNUSUAL FOR THE MIDDLE
OF SUMMER...THAT IS EXPECTED TO IMPACT THE AREA FOR THE NEXT 24-36
HOURS. MAIN FORECAST CONCERNS TODAY REVOLVE AROUND PRECIPITATION
CHANCES AND TEMPERATURES WHILE THIS SYSTEM MOVES THROUGH. OTHER
THAN THAT...THE WEATHER FOR THE COMING WEEK IS RATHER QUIET..WITH
THE EXCEPTION BEING A STRONG FRONTAL PASSAGE AROUND THURSDAY NIGHT
AND THE ASSOCIATED RISK OF SHOWERS/STORMS. TEMPERATURES WILL
AVERAGE COOLER THAN NORMAL FOR MUCH OF THE WEEK...ESPECIALLY BY
NEXT WEEKEND...A RARE OCCURRENCE THIS SUMMER..
12Z MODELS IN GOOD AGREEMENT OVERALL. HOWEVER...THE GFS HAS BEEN
IGNORED FOR THE APPROACHING SYSTEM. THE MORE SOUTHERN SURFACE LOW
TRACK ADVERTISED BY THE MODEL CONSENSUS IS SUPPORTED BY RECENT
SURFACE PRESSURE FALLS AND MAKES MORE SENSE CONSIDERING THE LOW
LEVEL THERMAL FIELD.
SHORT TERM...TONIGHT THROUGH WEDNESDAY...THE UPSTREAM SYSTEM IS
PROGGED TO TRACK THROUGH THE LOWER MIDWEST...WITH THE SURFACE
LOW TRACKING IN THE VICINITY OF THE MO/IL BORDER. WEAK
WAA/ISENTROPIC LIFT IN ADVANCE OF THE SYSTEM HAS RESULTED IN
ABUNDANT MID/HIGH LEVEL CLOUDINESS AND SOME LIGHT SHOWERS. MANY OF
THE ECHOES ON RADAR ARE NOT REACHING THE GROUND OR ONLY FALLING AS
VERY LIGHT SPRINKLES DUE TO A DRY LOW LEVEL AIRMASS. WHILE MOST OF
THE FORECAST AREA SHOULD BE NORTH OF THE SURFACE LOW TRACK...THE
EXPECTED FORCING AND MOISTURE AVAILABILITY AS THE SYSTEM MOVES
THROUGH SHOULD PRECLUDE SIGNIFICANT RAINFALL. WATER VAPOR IMAGERY
IS ALREADY SHOWING DRY AIR BEING WRAPPED INTO UPPER WAVE WHICH IS
NOT GOING TO BE CONDUCIVE FOR IT BEING A GOOD RAIN PRODUCER.
PRECIPITATION CHANCES WILL END FROM WEST TO EAST MONDAY AS THE
SYSTEM DEPARTS.
HIGH PRESSURE AT THE SURFACE AND NEUTRAL FLOW ALOFT WILL BUILD IN
BEHIND THE EARLY WEEK SYSTEM AND PROVIDE QUIET WEATHER.
TEMPERATURES WILL MODERATE EACH DAY...WITH WEDNESDAY EXPECTED TO
BE THE HOTTEST DAY OF THE WEEK WITH THE BEST COMBINATION OF
SUNSHINE AND SOUTHERLY RETURN FLOW.
LONG TERM...THURSDAY THROUGH SUNDAY...A VIGOROUS WAVE/STRONG COLD
FRONT IS PROGGED TO ARRIVE AROUND THURSDAY NIGHT. THERE HAS BEEN A
SLIGHTLY SLOWER TREND IN THE MODEL CONSENSUS...AND HAVE REMOVED
MENTIONABLE POPS FROM WEDNESDAY NIGHT. IF THE SLOWER TREND
CONTINUES...THURSDAY MAY END UP DRY AS WELL. WHILE IT IS TOO SOON
TO TELL WITH ANY CERTAINTY...THIS SYSTEM IS APT TO BE STRONG
ENOUGH TO BE A SEVERE WEATHER PRODUCER...ESPECIALLY IF THE FRONT
ARRIVES AT THE RIGHT TIME OF DAY. THE UPPER LEVEL FLOW IS EXPECTED
TO AMPLIFY HEADING INTO THE WEEKEND BEHIND THE WAVE/FRONT AND
SHOULD USHER IN ANOTHER UNSEASONABLY COOL AUGUST AIRMASS AS
TROFFING DIGS ACROSS THE EASTERN UNITED STATES.
BAK
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1133 AM EDT MON AUG 13 2012
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 337 AM EDT MON AUG 13 2012
AN AREA OF LOW PRESSURE WILL MOVE THROUGH THE AREA TODAY AND TONIGHT
BRINGING SHOWERS AND THUNDERSTORMS. A COLD FRONT WILL MOVE INTO THE
AREA ON THURSDAY...BRINGING ANOTHER CHANCE FOR RAIN FOR THE END OF
THE WEEK. BEHIND THIS COLD FRONT...BELOW AVERAGE TEMPERATURES WILL
RETURN FOR NEXT WEEKEND.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1133 AM EDT MON AUG 13 2012
LOW PRESSURE CONTINUES TO SPIN NEAR ST. LOUIS. THIS LOW WILL SLOWLY
WORK ITS WAY TOWARD THE FORECAST AREA THIS AFTERNOON.
MAIN AREA OF SHOWERS AND THUNDERSTORMS IS SKIRTING THE FAR SOUTHERN
FORECAST AREA THIS MORNING. THIS IS BEING DRIVEN BY A LOW LEVEL JET.
THIS AREA SHOULD CONTINUE TO SLIDE OFF TO THE EAST INTO EARLY
AFTERNOON. OTHER SCATTERED SHOWERS WERE DEVELOPING ACROSS NORTHWEST
INDIANA AND NORTHERN ILLINOIS IN ISENTROPIC LIFT AHEAD OF THE LOW.
WITH THE BULK OF THE RAIN REMAINING TO THE SOUTH THROUGH MID
AFTERNOON CLOSER TO THE LOW LEVEL JET...HAVE ONLY WENT CHANCE POPS
THROUGH MID AFTERNOON. ISENTROPIC LIFT AHEAD OF THE LOW WILL
CONTINUE TO PRODUCE SCATTERED SHOWERS...AND PERHAPS A THUNDERSTORM.
DID KEEP LIKELY POPS LATE THIS AFTERNOON ACROSS THE WEST AS MODELS
CONTINUE TO HINT AT SOME CONVECTIVE DEVELOPMENT AHEAD OF THE LOW.
LOWERED TEMPERATURES A LITTLE THIS AFTERNOON DUE TO CLOUD
COVER...BUT SATELLITE DOES SHOW SOME BREAKS IN THE CLOUDS AHEAD OF
THE LOW. TEMPERATURES SHOULD REBOUND WELL IN THE AREAS OF
SUNSHINE...SO DIDN/T CUT TEMPERATURES TOO MUCH.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 337 AM EDT MON AUG 13 2012
AS STATED ABOVE MODELS ARE NOT SO PROGRESSIVE WITH THIS SYSTEM.
HAVE OPTED TO CARRY LIKELY POPS...ESPECIALLY ACROSS THE EASTERN
HALF OF THE CWA WELL INTO THIS EVENING. LAST OF THE PRECIP DOES
NOT LOOK TO EXIT THE FORECAST AREA UNTIL EARLY TUESDAY MORNING.
AN UPPER TROUGH WILL REMAIN ACROSS THE AREA ON TUESDAY HOWEVER
CONDITIONS WILL BE DRY AND SKIES WILL SLOWLY BEGIN TO CLEAR. HIGH
PRESSURE WILL THEN KEEP DRY CONDITIONS THROUGH MID WEEK.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
ISSUED AT 337 AM EDT MON AUG 13 2012
MODELS MAINTAIN CONSISTENCY IN REGARD TO SYSTEM AT THE BEGINNING OF
THE EXTENDED PERIOD. INITIALIZATION CONTINUES TO PULL IN LIKELY
POPS ON THURSDAY NIGHT AS AN ASSOCIATED COLD FRONT TRACKS ACROSS
CENTRAL INDIANA. SCATTERED SHOWERS AND THUNDERSTORMS WILL PERSIST
THROUGH FRIDAY AFTERNOON...AND THEN TAPER OFF AS THE SYSTEM EXITS
THE REGION. IN ITS WAKE...A LARGE RIDGE OF HIGH PRESSURE OVER THE
WESTERN U.S. WILL CONTRIBUTE TO DRIER CONDITIONS AND COOLER TEMPS
FOR THE REMAINDER OF THE LONG TERM PERIOD.
&&
.AVIATION /DISCUSSION FOR THE IND 131500Z TAF UPDATE/...
VFR CONDITIONS EXPECTED TO CONTINUE THIS AFTERNOON.
RADAR TRENDS SHOW PRECIP SHIELD STRETCHING EAST OF INDIANAPOLIS
SOUTHWEST TOWARD EVANSVILLE. THE PRECIPITATION WAS SLOWLY SLIDING
EAST...HOWEVER ISOLATED SHRA WERE POPPING UP IN WESTERN INDIANA IN
THE WAKE. BEST FORCING WILL CONTINUE TO DRIFT EAST THIS
AFTERNOON...ENDING THE WIDESPREAD RAIN CHCS. HOWEVER HRRR SUGGEST
CONVECTION DEVELOPING IN WESTERN INDIANA THIS AFTERNOON AND
SPREADING ACROSS CENTRAL INDIANA INCLUDING THE IND AREA. THUS WILL
INCLUDE SOME VCTS LATER THIS AFTERNOON AND EVENING DURING MAX
HEATING HOURS.
/DISCUSSION FOR THE 13/12Z TAF ISSUANCE/...
ISSUED AT 717 AM EDT MON AUG 13 2012
WIDESPREAD SHOWERS AND THUNDERSTORMS WILL COVER ALL TAF SITES FOR
THE MAJORITY OF THE TAF PERIOD. ANTICIPATE MAINLY RAINFALL WITH
SOME EMBEDDED LIGHTNING THROUGH THE COURSE OF THE DAY...SO WILL
ONLY COVER WITH VCTS FOR NOW. IF ANYTHING BECOMES MORE
ORGANIZED...IT WILL HAVE TO BE ADDRESSED WITH FUTURE UPDATES...BUT
BEST CHANCES FOR SEVERE STORMS ARE SOUTH OF TAF SITES. FOR
NOW...EXPECTING VFR CONDITIONS THROUGH THE DURATION OF TAF PERIOD.
HOWEVER...WILL NOT RULE OUT POSSIBLE FOG FORMATION LATE
TONIGHT...ESPECIALLY AT KLAF AND KHUF WHERE THERE COULD BE
CLEARING SOONER THAN AT OTHER TAF SITES. CONFIDENCE IS NOT HIGH
THOUGH BECAUSE WINDS MAY BE A BIT TOO STRONG...AND CURRENT
THINKING IS THAT CLOUDS WILL HANG IN THERE. AS A RESULT...WILL
LEAVE MENTION OUT OF TAFS FOR NOW. WINDS WILL START OUT
SOUTHEASTERLY AND THEN VEER TO THE SOUTH...AND FINALLY WEST BY
TONIGHT. SUSTAINED SPEEDS WILL RANGE FROM 5 TO 10 KTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SMF
NEAR TERM...50
SHORT TERM...SMF
LONG TERM....TDUD
AVIATION...TDUD/JP
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1030 AM EDT MON AUG 13 2012
.UPDATE...
AVIATION SECTION UPDATED
&&
.SYNOPSIS...
ISSUED AT 337 AM EDT MON AUG 13 2012
AN AREA OF LOW PRESSURE WILL MOVE THROUGH THE AREA TODAY AND TONIGHT
BRINGING SHOWERS AND THUNDERSTORMS. A COLD FRONT WILL MOVE INTO THE
AREA ON THURSDAY...BRINGING ANOTHER CHANCE FOR RAIN FOR THE END OF
THE WEEK. BEHIND THIS COLD FRONT...BELOW AVERAGE TEMPERATURES WILL
RETURN FOR NEXT WEEKEND.
&&
.NEAR TERM /TODAY/...
ISSUED AT 337 AM EDT MON AUG 13 2012
FORECAST FOCUS IS ON RAIN THIS PERIOD. MODELS ARE IN GENERAL
AGREEMENT...WITH SOME MINOR DIFFERENCES SO WILL USE A BLEND.
NOTED TWO DIFFERENT THINGS WITH THIS MODEL RUN AS COMPARED TO THIS
TIME YESTERDAY. FIRST THIS SYSTEM IS NOT AS PROGRESSIVE AS
ORIGINALLY DEPICTED...INSTEAD TRANSVERSING VERY SLOWLY OVER A 12+
HR PERIOD ACROSS INDIANA. AND SECOND IT IS NOT AS BULLISH WITH THE
QPF AMOUNTS...SURPRISING SOMEWHAT CONSIDERING THE SLOWER TIMING.
SEVERE THREAT APPEARS MINIMAL...HOWEVER CENTRAL INDIANA WILL
LIKELY SEE PERIODS OF HEAVY RAIN AND CHANCES FOR HAIL...AND STRONG
WINDS. BETTER INSTABILITY AND SLIGHT RISK FOR SEVERE WEATHER LIES
JUST TO THE SOUTH OF THE FORECAST AREA. GRAZING ONLY THE FAR SW
COUNTIES OF CWA.
KEPT POPS LIKELY FOR TODAY. TRIED TO SHOW THE TRANSITION OF HIGHER
POPS FROM W TO E GOING INTO THIS EVENING. WENT SLIGHTLY BELOW MOS TO
ACCOUNT FOR CLOUDS/RAIN FOR HIGHS IN THE UPPER 70S TO LOW/MID 80S.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 337 AM EDT MON AUG 13 2012
AS STATED ABOVE MODELS ARE NOT SO PROGRESSIVE WITH THIS SYSTEM.
HAVE OPTED TO CARRY LIKELY POPS...ESPECIALLY ACROSS THE EASTERN
HALF OF THE CWA WELL INTO THIS EVENING. LAST OF THE PRECIP DOES
NOT LOOK TO EXIT THE FORECAST AREA UNTIL EARLY TUESDAY MORNING.
AN UPPER TROUGH WILL REMAIN ACROSS THE AREA ON TUESDAY HOWEVER
CONDITIONS WILL BE DRY AND SKIES WILL SLOWLY BEGIN TO CLEAR. HIGH
PRESSURE WILL THEN KEEP DRY CONDITIONS THROUGH MID WEEK.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
ISSUED AT 337 AM EDT MON AUG 13 2012
MODELS MAINTAIN CONSISTENCY IN REGARD TO SYSTEM AT THE BEGINNING OF
THE EXTENDED PERIOD. INITIALIZATION CONTINUES TO PULL IN LIKELY
POPS ON THURSDAY NIGHT AS AN ASSOCIATED COLD FRONT TRACKS ACROSS
CENTRAL INDIANA. SCATTERED SHOWERS AND THUNDERSTORMS WILL PERSIST
THROUGH FRIDAY AFTERNOON...AND THEN TAPER OFF AS THE SYSTEM EXITS
THE REGION. IN ITS WAKE...A LARGE RIDGE OF HIGH PRESSURE OVER THE
WESTERN U.S. WILL CONTRIBUTE TO DRIER CONDITIONS AND COOLER TEMPS
FOR THE REMAINDER OF THE LONG TERM PERIOD.
&&
.AVIATION /DISCUSSION FOR THE IND 131500Z TAF UPDATE/...
VFR CONDITIONS EXPECTED TO CONTINUE THIS AFTERNOON.
RADAR TRENDS SHOW PRECIP SHIELD STRETCHING EAST OF INDIANAPOLIS
SOUTHWEST TOWARD EVANSVILLE. THE PRECIPITATION WAS SLOWLY SLIDING
EAST...HOWEVER ISOLATED SHRA WERE POPPING UP IN WESTERN INDIANA IN
THE WAKE. BEST FORCING WILL CONTINUE TO DRIFT EAST THIS
AFTERNOON...ENDING THE WIDESPREAD RAIN CHCS. HOWEVER HRRR SUGGEST
CONVECTION DEVELOPING IN WESTERN INDIANA THIS AFTERNOON AND
SPREADING ACROSS CENTRAL INDIANA INCLUDING THE IND AREA. THUS WILL
INCLUDE SOME VCTS LATER THIS AFTERNOON AND EVENING DURING MAX
HEATING HOURS.
/DISCUSSION FOR THE 13/12Z TAF ISSUANCE/...
ISSUED AT 717 AM EDT MON AUG 13 2012
WIDESPREAD SHOWERS AND THUNDERSTORMS WILL COVER ALL TAF SITES FOR
THE MAJORITY OF THE TAF PERIOD. ANTICIPATE MAINLY RAINFALL WITH
SOME EMBEDDED LIGHTNING THROUGH THE COURSE OF THE DAY...SO WILL
ONLY COVER WITH VCTS FOR NOW. IF ANYTHING BECOMES MORE
ORGANIZED...IT WILL HAVE TO BE ADDRESSED WITH FUTURE UPDATES...BUT
BEST CHANCES FOR SEVERE STORMS ARE SOUTH OF TAF SITES. FOR
NOW...EXPECTING VFR CONDITIONS THROUGH THE DURATION OF TAF PERIOD.
HOWEVER...WILL NOT RULE OUT POSSIBLE FOG FORMATION LATE
TONIGHT...ESPECIALLY AT KLAF AND KHUF WHERE THERE COULD BE
CLEARING SOONER THAN AT OTHER TAF SITES. CONFIDENCE IS NOT HIGH
THOUGH BECAUSE WINDS MAY BE A BIT TOO STRONG...AND CURRENT
THINKING IS THAT CLOUDS WILL HANG IN THERE. AS A RESULT...WILL
LEAVE MENTION OUT OF TAFS FOR NOW. WINDS WILL START OUT
SOUTHEASTERLY AND THEN VEER TO THE SOUTH...AND FINALLY WEST BY
TONIGHT. SUSTAINED SPEEDS WILL RANGE FROM 5 TO 10 KTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....TDUD
AVIATION...TDUD/JP
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
427 AM EDT MON AUG 13 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 337 AM EDT MON AUG 13 2012
AN AREA OF LOW PRESSURE WILL MOVE THROUGH THE AREA TODAY AND TONIGHT
BRINGING SHOWERS AND THUNDERSTORMS. A COLD FRONT WILL MOVE INTO THE
AREA ON THURSDAY...BRINGING ANOTHER CHANCE FOR RAIN FOR THE END OF
THE WEEK. BEHIND THIS COLD FRONT...BELOW AVERAGE TEMPERATURES WILL
RETURN FOR NEXT WEEKEND.
&&
.NEAR TERM /TODAY/...
ISSUED AT 337 AM EDT MON AUG 13 2012
FORECAST FOCUS IS ON RAIN THIS PERIOD. MODELS ARE IN GENERAL
AGREEMENT...WITH SOME MINOR DIFFERENCES SO WILL USE A BLEND.
NOTED TWO DIFFERENT THINGS WITH THIS MODEL RUN AS COMPARED TO THIS
TIME YESTERDAY. FIRST THIS SYSTEM IS NOT AS PROGRESSIVE AS
ORIGINALLY DEPICTED...INSTEAD TRANSVERSING VERY SLOWLY OVER A 12+
HR PERIOD ACROSS INDIANA. AND SECOND IT IS NOT AS BULLISH WITH THE
QPF AMOUNTS...SURPRISING SOMEWHAT CONSIDERING THE SLOWER TIMING.
SEVERE THREAT APPEARS MINIMAL...HOWEVER CENTRAL INDIANA WILL
LIKELY SEE PERIODS OF HEAVY RAIN AND CHANCES FOR HAIL...AND STRONG
WINDS. BETTER INSTABILITY AND SLIGHT RISK FOR SEVERE WEATHER LIES
JUST TO THE SOUTH OF THE FORECAST AREA. GRAZING ONLY THE FAR SW
COUNTIES OF CWA.
KEPT POPS LIKELY FOR TODAY. TRIED TO SHOW THE TRANSITION OF HIGHER
POPS FROM W TO E GOING INTO THIS EVENING. WENT SLIGHTLY BELOW MOS TO
ACCOUNT FOR CLOUDS/RAIN FOR HIGHS IN THE UPPER 70S TO LOW/MID 80S.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 337 AM EDT MON AUG 13 2012
AS STATED ABOVE MODELS ARE NOT SO PROGRESSIVE WITH THIS SYSTEM.
HAVE OPTED TO CARRY LIKELY POPS...ESPECIALLY ACROSS THE EASTERN
HALF OF THE CWA WELL INTO THIS EVENING. LAST OF THE PRECIP DOES
NOT LOOK TO EXIT THE FORECAST AREA UNTIL EARLY TUESDAY MORNING.
AN UPPER TROUGH WILL REMAIN ACROSS THE AREA ON TUESDAY HOWEVER
CONDITIONS WILL BE DRY AND SKIES WILL SLOWLY BEGIN TO CLEAR. HIGH
PRESSURE WILL THEN KEEP DRY CONDITIONS THROUGH MID WEEK.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
ISSUED AT 337 AM EDT MON AUG 13 2012
MODELS MAINTAIN CONSISTENCY IN REGARD TO SYSTEM AT THE BEGINNING OF
THE EXTENDED PERIOD. INITIALIZATION CONTINUES TO PULL IN LIKELY
POPS ON THURSDAY NIGHT AS AN ASSOCIATED COLD FRONT TRACKS ACROSS
CENTRAL INDIANA. SCATTERED SHOWERS AND THUNDERSTORMS WILL PERSIST
THROUGH FRIDAY AFTERNOON...AND THEN TAPER OFF AS THE SYSTEM EXITS
THE REGION. IN ITS WAKE...A LARGE RIDGE OF HIGH PRESSURE OVER THE
WESTERN U.S. WILL CONTRIBUTE TO DRIER CONDITIONS AND COOLER TEMPS
FOR THE REMAINDER OF THE LONG TERM PERIOD.
&&
.AVIATION /DISCUSSION FOR THE 13/09Z TAF UPDATE /...
ISSUED AT 419 AM EDT MON AUG 13 2012
UPDATE...
NO CHANGES.
PREVIOUS DISCUSSION...
VFR THROUGH THE PERIOD.
MIDLEVEL OVERCAST ASSOCIATED WITH APPROACHING DISTURBANCE WILL
CONTINUE TO OVERSPREAD THE SITES DURING THE PERIOD. AN AREA OF
ECHOES ON REGIONAL RADAR MOSAIC...INCLUDING SOME THUNDERSTORMS...ARE
UNLIKELY TO SURVIVE INTO THE AREA IN THEIR CURRENT FORM PER HRRR AND
SREF PROBABILITIES. WILL MAINTAIN VCTS MENTION FOR TOMORROW FROM
PREVIOUS TAFS AS SURFACE AND UPPER LOW APPROACH.
WINDS WILL BE LIGHT AND VARIABLE EARLY...BECOMING SOUTHERLY IN THE
MORNING...GENERALLY REMAINING 10KT OR BELOW.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....TDUD
AVIATION...NIELD/TDUD
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
347 AM EDT MON AUG 13 2012
.UPDATE...
THE SYNOPSIS...NEAR TERM...SHORT TERM AND LONG TERM SECTIONS HAVE
BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 337 AM EDT MON AUG 13 2012
AN AREA OF LOW PRESSURE WILL MOVE THROUGH THE AREA TODAY AND TONIGHT
BRINGING SHOWERS AND THUNDERSTORMS. A COLD FRONT WILL MOVE INTO THE
AREA ON THURSDAY...BRINGING ANOTHER CHANCE FOR RAIN FOR THE END OF
THE WEEK. BEHIND THIS COLD FRONT...BELOW AVERAGE TEMPERATURES WILL
RETURN FOR NEXT WEEKEND.
&&
.NEAR TERM /TODAY/...
ISSUED AT 337 AM EDT MON AUG 13 2012
FORECAST FOCUS IS ON RAIN THIS PERIOD. MODELS ARE IN GENERAL
AGREEMENT...WITH SOME MINOR DIFFERENCES SO WILL USE A BLEND.
NOTED TWO DIFFERENT THINGS WITH THIS MODEL RUN AS COMPARED TO THIS
TIME YESTERDAY. FIRST THIS SYSTEM IS NOT AS PROGRESSIVE AS
ORIGINALLY DEPICTED...INSTEAD TRANSVERSING VERY SLOWLY OVER A 12+
HR PERIOD ACROSS INDIANA. AND SECOND IT IS NOT AS BULLISH WITH THE
QPF AMOUNTS...SURPRISING SOMEWHAT CONSIDERING THE SLOWER TIMING.
SEVERE THREAT APPEARS MINIMAL...HOWEVER CENTRAL INDIANA WILL
LIKELY SEE PERIODS OF HEAVY RAIN AND CHANCES FOR HAIL...AND STRONG
WINDS. BETTER INSTABILITY AND SLIGHT RISK FOR SEVERE WEATHER LIES
JUST TO THE SOUTH OF THE FORECAST AREA. GRAZING ONLY THE FAR SW
COUNTIES OF CWA.
KEPT POPS LIKELY FOR TODAY. TRIED TO SHOW THE TRANSITION OF HIGHER
POPS FROM W TO E GOING INTO THIS EVENING. WENT SLIGHTLY BELOW MOS TO
ACCOUNT FOR CLOUDS/RAIN FOR HIGHS IN THE UPPER 70S TO LOW/MID 80S.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 337 AM EDT MON AUG 13 2012
AS STATED ABOVE MODELS ARE NOT SO PROGRESSIVE WITH THIS SYSTEM.
HAVE OPTED TO CARRY LIKELY POPS...ESPECIALLY ACROSS THE EASTERN
HALF OF THE CWA WELL INTO THIS EVENING. LAST OF THE PRECIP DOES
NOT LOOK TO EXIT THE FORECAST AREA UNTIL EARLY TUESDAY MORNING.
AN UPPER TROUGH WILL REMAIN ACROSS THE AREA ON TUESDAY HOWEVER
CONDITIONS WILL BE DRY AND SKIES WILL SLOWLY BEGIN TO CLEAR. HIGH
PRESSURE WILL THEN KEEP DRY CONDITIONS THROUGH MID WEEK.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
ISSUED AT 337 AM EDT MON AUG 13 2012
MODELS MAINTAIN CONSISTENCY IN REGARD TO SYSTEM AT THE BEGINNING OF
THE EXTENDED PERIOD. INITIALIZATION CONTINUES TO PULL IN LIKELY
POPS ON THURSDAY NIGHT AS AN ASSOCIATED COLD FRONT TRACKS ACROSS
CENTRAL INDIANA. SCATTERED SHOWERS AND THUNDERSTORMS WILL PERSIST
THROUGH FRIDAY AFTERNOON...AND THEN TAPER OFF AS THE SYSTEM EXITS
THE REGION. IN ITS WAKE...A LARGE RIDGE OF HIGH PRESSURE OVER THE
WESTERN U.S. WILL CONTRIBUTE TO DRIER CONDITIONS AND COOLER TEMPS
FOR THE REMAINDER OF THE LONG TERM PERIOD.
&&
.AVIATION /DISCUSSION FOR THE 13/06Z TAFS/...
ISSUED AT 105 AM EDT MON AUG 13 2012
VFR THROUGH THE PERIOD.
MIDLEVEL OVERCAST ASSOCIATED WITH APPROACHING DISTURBANCE WILL
CONTINUE TO OVERSPREAD THE SITES DURING THE PERIOD. AN AREA OF
ECHOES ON REGIONAL RADAR MOSAIC...INCLUDING SOME THUNDERSTORMS...ARE
UNLIKELY TO SURVIVE INTO THE AREA IN THEIR CURRENT FORM PER HRRR AND
SREF PROBABILITIES. WILL MAINTAIN VCTS MENTION FOR TOMORROW FROM
PREVIOUS TAFS AS SURFACE AND UPPER LOW APPROACH.
WINDS WILL BE LIGHT AND VARIABLE EARLY...BECOMING SOUTHERLY IN THE
MORNING...GENERALLY REMAINING 10KT OR BELOW.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....TDUD
AVIATION...NIELD
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
112 AM EDT MON AUG 13 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 242 PM EDT SUN AUG 12 2012
AN AREA OF LOW PRESSURE WILL MOVE THROUGH THE AREA ON MONDAY
BRINGING SHOWERS AND THUNDERSTORMS. A COLD FRONT WILL MOVE INTO
THE AREA ON THURSDAY...BRINGING ANOTHER CHANCE FOR RAIN FOR THE
END OF THE WEEK. BEHIND THIS COLD FRONT...BELOW AVERAGE
TEMPERATURES WILL RETURN FOR NEXT WEEKEND.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 1000 PM EDT SUN AUG 12 2012
MODEL ISENTROPIC DATA ON THE 305K LEVEL SUGGESTS BEST CHANCE OF
LIGHT SHOWERS WILL BE ACROSS NORTHWEST PARTS OF THE FORECAST AREA
OVERNIGHT. SO...BUMPED UP POPS A BIT THERE TO AROUND 40 PERCENT AND
KEEP THE REST OF THE FORECAST AREA ESENTIALLY THE SAME.
OTHERWISE...HAD TO MAKE SOME CHANGES TO TEMPERATURES AND DEW POINTS
THE NEXT COUPLE OF HOURS BASED ON 01Z OBS AND TRENDS.
PREVIOUS DISCUSSION FOLLOWS...
ISENTROPIC LIFT WILL TRY TO GENERATE RAIN ACROSS THE FORECAST AREA
TONIGHT...BUT A DRY LOWER ATMOSPHERE WILL WORK AGAINST THE RAIN.
DEWPOINTS THIS AFTERNOON ARE IN THE 40S ACROSS PARTS OF THE
FORECAST AREA...WITH DEWPOINTS IN THE 50S EXTENDING WEST WELL INTO
ILLINOIS.
ANY RAIN THAT HAS TRIED TO MAKE IT EAST TOWARD THE FORECAST AREA
THIS AFTERNOON HAS DRIED OUT THANKS TO THE DRY ATMOSPHERE IN
PLACE. THIS TREND WILL CONTINUE THROUGH THE EVENING...SO HAVE LEFT
THE EVENING DRY. OVERNIGHT...MOISTURE IMPROVES AND FORCING GETS
BETTER ACROSS THE WESTERN HALF OF THE FORECAST AREA...BUT NOTHING
IS IMPRESSIVE.
THUS WILL ONLY GO LOW POPS ACROSS THE WESTERN FORECAST AREA
OVERNIGHT...AND WILL TIME FOR MAINLY AFTER 09Z.
WITH INCREASING CLOUDS TONIGHT...A BLEND OF MODEL TEMPERATURES
LOOKS GOOD FOR LOW TEMPERATURES.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
ISSUED AT 242 PM EDT SUN AUG 12 2012
FOCUS IS ON CHANCES FOR RAIN EARLY IN THE PERIOD. FOR THE MOST
PART MODELS ARE IN DECENT AGREEMENT. GFS IS FARTHER NORTH THAN THE
OTHER MODELS WITH THE SURFACE LOW ON MONDAY...BUT SREF MEAN IS
ALSO FARTHER NORTH. THUS AM NOT GOING TO COMPLETELY DISREGARD THE
GFS...BUT WILL KEEP IT IN THE BLEND.
MODELS ARE NOT QUITE AS BULLISH WITH RAINFALL WITH THE NEXT
SYSTEM. HOWEVER FORCING AHEAD OF THE SURFACE LOW ON MONDAY SHOULD
BE ENOUGH FOR LIKELY POPS MOST AREAS. WITH LESS CONFIDENCE THOUGH
WILL ONLY GO ON LOW END OF LIKELY CATEGORY MONDAY.
THE LOW WILL EXIT THE AREA MONDAY NIGHT. WILL GO HIGHEST POPS
DURING THE EVENING THEN DIMINISH OVERNIGHT AS LOW EXITS THE AREA.
AN UPPER TROUGH REMAINS ACROSS THE AREA ON TUESDAY...BUT MOISTURE
SHOULD BE OUT OF THE AREA BY THEN. AS USUAL GFS OVERDOES MOISTURE
AND THUS GENERATES RAINFALL ON TUESDAY...BUT OTHER MODELS ARE
DRY. WILL THUS KEEP DRY FORECAST.
HIGH PRESSURE WILL THEN KEEP DRY CONDITIONS INTO WEDNESDAY.
MOS ACTUALLY DOES NOT LOOK TOO BAD FOR HIGHS MONDAY GIVEN EXPECTED
CONDITIONS. STUCK WITH A MODEL BLEND FOR LOWS MONDAY NIGHT AND
TUESDAY NIGHT. GIVEN RETURN OF SUNSHINE DURING TUESDAY WENT AT OR
ABOVE MOS FOR HIGHS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
ISSUED AT 205 PM EDT SUN AUG 12 2012
GFS AND ECMWF CONTINUE A PERSISTENT NW FLOW ALOFT DURING THIS
FORECAST PERIOD. THE MAIN WX EVENT DURING THE PERIOD WILL BE A
SHORT WAVE THAT WILL APPROACH AND PUSH THROUGH THE AREA ON
WEDNESDAY NIGHT THROUGH FRIDAY...BRINGING CHANCES FOR SHOWERS AND
THUNDERSTORMS. THE UPPER PATTERN CONTINUES TO INDICATE A HIGHLY
AMPLIFIED PATTERN THROUGH NEXT WEEKEND WITH STRONG RIDGING
BUILDING ACROSS THE WESTERN UNITED STATES AND COOL NORTHWEST FLOW
SPILLING INTO THE OHIO VALLEY FROM CENTRAL CANADA. THUS OTHER THAN
THE PREVIOUSLY MENTIONED PASSING SHORT WAVE...DRY AND COOLER
WEATHER WILL BE EXPECTED WITH HIGH TEMPERATURES AT OR BELOW
SEASONAL NORMALS.
&&
.AVIATION /DISCUSSION FOR THE 13/06Z TAFS/...
ISSUED AT 105 AM EDT MON AUG 13 2012
VFR THROUGH THE PERIOD.
MIDLEVEL OVERCAST ASSOCIATED WITH APPROACHING DISTURBANCE WILL
CONTINUE TO OVERSPREAD THE SITES DURING THE PERIOD. AN AREA OF
ECHOES ON REGIONAL RADAR MOSAIC...INCLUDING SOME THUNDERSTORMS...ARE
UNLIKELY TO SURVIVE INTO THE AREA IN THEIR CURRENT FORM PER HRRR AND
SREF PROBABILITIES. WILL MAINTAIN VCTS MENTION FOR TOMORROW FROM
PREVIOUS TAFS AS SURFACE AND UPPER LOW APPROACH.
WINDS WILL BE LIGHT AND VARIABLE EARLY...BECOMING SOUTHERLY IN THE
MORNING...GENERALLY REMAINING 10KT OR BELOW.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...50/MK
SHORT TERM...50
LONG TERM....PUMA
AVIATION...NIELD
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
642 AM CDT MON AUG 13 2012
.UPDATE...
A NARROW BAND OF FORCING/CONVERGENCE IS HELPING TO MAINTAIN LIGHT
RAIN FROM ROUGHLY KOTM TO SOUTH OF KRFD. BASED ON OVERALL CLOUD
MOVEMENT ACROSS THE DAKOTAS/MINNESOTA SKIES WILL BE SLOW TO CLEAR
DURING THE DAY. SAID CLEARING WILL HAVE AN IMPACT ON MAX TEMPERATURES
TODAY.
SFC OBS INDICATE DZ IS OCCURRING BUT NOT TO THE EXTENT OF A FEW
HOURS AGO. LOW CLOUDS AND CONDENSATION PRESSURE DEFICITS INDICATE
THAT DZ WILL BE POSSIBLE IN AREAS THAT DO NOT HAVE SHRA OR LIGHT
RAIN. RAP TRENDS WITH FCST SOUNDINGS DO SHOW A SLOW DRYING ALOFT
SUGGESTING DZ THROUGH THE MORNING HOURS.
CURRENT PLAN IS TO UPDATE THE FCST TO THE CURRENT TRENDS/THINKING.
THE APPARENT BACK EDGE OF ANY -RA/DZ APPEARS TO BE THE AXIS OF THE
NEXT VORT MAX DROPPING DOWN THROUGH THE SHORTWAVE. IF THE RAP
TRENDS ARE CORRECT...MOST AREAS WEST OF THE MISSISSIPPI SHOULD BE
DRY DURING THE AFTERNOON AS NVA BEHIND THE VORT MAX TAKES OVER.
NON-MEASURABLE PRECIP MAY LINGER INTO THE AFTERNOON EAST OF THE
MISSISSIPPI DUE TO THE WEAKENING VORT MAX. ..08..
&&
.AVIATION...
CONDITIONS RANGE FROM IFR TO VFR BUT WILL SLOWLY IMPROVE VFR
THROUGH 00Z/14. THE LIGHT RAIN/DRIZZLE WILL SLOWLY END FROM WEST
TO EAST AS A STORM SYSTEM NEAR KSTL MOVES INTO THE OHIO VALLEY.
HIGH PRESSURE BUILDING INTO THE AREA AFT 00Z/14 WILL CREATE LIGHT
WINDS. THE LIGHT WINDS AND WET GROUND MAY ALLOW FG TO DVLP AFT
06Z/14 AS HAS HAPPENED IN MINNESOTA. FG POTENTIAL WAS SUGGESTED
WITH THE 12Z TAFS WITH A FEW CLOUDS BLO 1KFT AGL. THE POTENTIAL
DOES EXIST FOR IFR/LIFR CONDITIONS AFT 06Z/14. ..08..
&&
.PREV DISCUSSION... /ISSUED 310 AM CDT MON AUG 13 2012/
SYNOPSIS...
06Z SFC ANALYSIS HAS A LOW NEAR KCOU WITH A WARM FRONT EAST ACROSS
SOUTHERN ILLINOIS. INVERTED TROFS RAN NORTHWEST FROM THE LOW INTO
WESTERN IOWA AND NORTHEAST INTO NORTHERN ILLINOIS. DEW POINTS WERE
IN THE 50S ACROSS MUCH OF THE MIDWEST EXCEPT FOR 60S AROUND THE LOW
AND INVERTED TROFS.
SHORT TERM...TODAY AND TONIGHT...
THE STRENGTHENING SYSTEM IN THE LOWER MISSOURI VALLEY WILL SLOWLY
MOVE INTO THE LOWER OHIO VALLEY BY MID DAY. BASED ON RADAR AND RAP
MODEL TRENDS THE DEFORMATION ZONE ACROSS THE AREA WILL SLOWLY WEAKEN
DURING THE MORNING HOURS. THE BETTER PRECIPITATION SHOULD BE EAST OF
THE MISSISSIPPI DURING THE MORNING WITH MORE SPRINKLES/DRIZZLE/LIGHT
RAIN WEST OF THE MISSISSIPPI. BY LATE MORNING CONDENSATION PRESSURE
DEFICITS BEGIN SLOWLY RISING OVER THE FAR NORTHWEST/WEST PARTS OF
THE CWFA SO RAIN THERE SHOULD END.
DURING THE AFTERNOON...THE OVERALL FORCING CONTINUES TO WEAKEN WITH
CONDENSATION PRESSURE DEFICITS SLOWLY RISING. THUS RAIN WILL DECAY
TO SHOWERS/SPRINKLES THAT END FROM WEST TO EAST DURING THE AFTERNOON
FROM THE MISSISSIPPI ON EAST.
TEMPERATURES WILL BE TRICKY TODAY AND WILL DEPEND UPON WHEN IT
CLEARS. BASED ON THE CURRENT POSITION OF THE CLOUDS...CLEARING
SHOULD BEGIN AROUND MID DAY IN THE FAR NORTHWEST PARTS OF THE CWFA
THAT SLOWLY MOVES EAST DURING THE AFTERNOON. THE FAR EASTERN PARTS
OF THE CWFA WILL LIKELY CLEAR JUST BEFORE/AFTER SUNSET. AS SUCH THE
EASTERN PARTS OF THE CWFA WILL LIKELY NOT GET OUT OF THE 60S TODAY
WHILE THE WESTERN THIRD TO HALF OF THE CWFA WILL BE IN THE MID 70S.
TONIGHT...QUIET AND DRY CONDITIONS ARE EXPECTED. THE LATE CLEARING
OF THE CLOUDS COMBINED WITH LIGHT WINDS AND WET GROUND RAISES THE
QUESTION OF FOG DEVELOPMENT. BASED ON WHAT IS CURRENTLY HAPPENING
UPSTREAM WHERE IT HAS CLEARED THIS CONCERN APPEARS VALID. FOR NOW
WILL CONFINE ANY MENTION OF FOG TO THE RIVER VALLEYS AND WORD IT AS
PATCHY. SUBSEQUENT SHIFTS WILL HAVE TO RE-EVALUATE THE FOG POTENTIAL
FOR LATE TONIGHT.
08
LONG TERM...TUESDAY THROUGH NEXT SUNDAY...
LIGHT TO MODERATE RAIN EVENT WITH NEXT SIGNIFICANT COLD FRONT LATE
WEDNESDAY INTO THURSDAY REMAINS THE PRIMARY FORECAST ISSUE.
OVERVIEW...
INITIALIZATION AND VERIFICATION IS POOR WITH PRECIPITATION AND
MOISTURE WITH MIDWEST STORM SYSTEM BUT ADEQUATE WITH UPSTREAM ENERGY
AFFECTING DAYS 2-7. VERIFICATION AT 06Z SUPPORTS A 50/50 BLEND OF GFS
AND HI-RES ECMWF WITH ONLY SENSIBLE WEATHER THE MID WEEK FRONTAL
PASSAGE.
TUESDAY/WEDNESDAY...ONLY MINOR CHANGES...FAIR SKIES AND A WARMING
TREND WITH MAXES IN THE LOWER 80S TUESDAY AND MID/UPPER 80S WEDNESDAY
AHEAD OF NEXT FRONT. MINS WEDNESDAY MORNING UPPER 50S TO AROUND 60
DEGREES. SOUTH WINDS TO INCREASE TO 10 TO 20+ MPH BY WEDNESDAY
AFTERNOON. WEDNESDAY NIGHT...AN AREA OR LINE OF SHOWERS AND STORMS TO
MOVE INTO NW SECTIONS BY MIDNIGHT AS COOL FRONT APPROACHES. TIMING
AT NIGHT AND LIMITED INSTABILITY DO NOT SUPPORT SEVERE ATTM WITH
LIGHT TO MODERATE RAIN AMOUNTS. HAVE HIGH CHANCE POPS NW TO SLIGHT
CHANCE POPS SE SECTIONS. MINS MOSTLY IN THE UPPER 60S TO AROUND 70.
THURSDAY...FRONT TO PASS EARLY DURING THE DAY AND TURNING COOLER.
MOST AREAS HAVE LIKELY POPS WITH FRONT SOUTHEAST OF AREA BY MID
AFTERNOON LIMITING CHANCE OF SEVERE. PW/S 1.25-1.5 CONTINUE TO
SUPPORT AT LEAST LIGHT TO MODERATE AMOUNTS OF RAIN. NORTHWEST WINDS
MAY INCREASE TO 15 TO 25 MPH BY MID TO LATE AFTERNOON BEHIND THE
FRONT WITH CLEARING SKIES.
FRIDAY AND SUNDAY...FAIR SKIES...PLEASANTLY COOL AND COMFORTABLE FOR
LATE SUMMER WITH HIGHS MOSTLY IN THE 70S WITH SOME UPPER 60S NORTH
SECTIONS POSSIBLE. THIS IS WELL BELOW NORMAL TEMPERATURES BY 10 TO 15
DEGREES FOR MID AUGUST. LOWS MAY NEED LOWERING BY UP TO 5 DEGREES
WITH MID 40S TO THE MID 50S. THIS MAY THREATEN THE LOW TEMP RECORDS
FOR SATURDAY AND SUNDAY MORNING THAT ARE IN THE UPPER 40S.
NICHOLS
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
1151 PM CDT SUN AUG 12 2012
.AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
MVFR CIGS CURRENTLY OVER NEBRASKA AND IOWA WILL FILTER SOUTH
TONIGHT...APPROACHING KSLN BY 10-12Z AND KCNU BY 12-14Z...AND
PERSISTING THROUGH A GOOD PORTION OF THE MORNING. CIGS HAVE THE
POTENTIAL TO GO BELOW 2000 FT AGL...BUT ONLY WENT BKN025 FOR NOW.
WESTERN EDGE OF CIGS MAY FLIRT WITH KHUT-KICT...BUT LEFT OUT OF
THOSE TAFS FOR NOW. OTHERWISE...LOW CIGS WILL DISSIPATE FAIRLY
QUICKLY WITH DAYTIME HEATING ALTHOUGH THEY COULD HANG INTO THE
EARLY AFTERNOON AT KCNU. MODEST/GUSTY NORTH WINDS WILL PREVAIL
FOR MOST SITES MONDAY.
KLEINSASSER
&&
.PREV DISCUSSION... /ISSUED 749 PM CDT SUN AUG 12 2012/
UPDATE...
STILL A SMALL OPPORTUNITY FOR A FEW THUNDERSTORMS OVER EXTREME
SOUTHEAST KANSAS THROUGH ABOUT 10 PM...AS THE COLD FRONT CONTINUES
TO SLOWLY MOVE SOUTHEAST. POOR LAPSE RATES PER 00Z SPRINGFIELD
SOUNDING AND ONLY MODEST LOW-LEVEL MOISTURE IS PREVENTING OFF THE
CHARTS INSTABILITY...ALTHOUGH 40 KTS OF DEEP LAYER SHEAR WOULD
SUPPORT STRONG TO MARGINALLY SEVERE WIND/HAIL WITH ANY ACTIVITY
THAT CAN DEVELOP. THREAT SHOULD END BY 10 PM.
KLEINSASSER
PREV DISCUSSION... /ISSUED 636 PM CDT SUN AUG 12 2012/
AVIATION...00Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
NARROW WINDOW FOR A STRAY THUNDERSTORM AT KCNU WILL END BY 01-02Z
THIS EVENING...ALONG A COLD FRONT SHIFTING SOUTHEAST ACROSS THE
REGION. DUE TO LOW PROBABILITIES...DID NOT INCLUDE VCTS IN KCNU
TAF. OTHERWISE...MODEST NORTH WINDS WILL CONTINUE TONIGHT. BY
11-13Z EARLY MONDAY MORNING...ANTICIPATING MVFR CIGS TO FILTER
SOUTH ACROSS EASTERN KS...AFFECTING PRIMARILY KCNU ALTHOUGH
WESTERN EDGE COULD CLIP KICT-KSLN. CIGS SHOULD RISE ABOVE MVFR BY
LATE MORNING/EARLY AFTERNOON...WITH MODESTLY GUSTY NORTH WINDS
ANTICIPATED AGAIN MONDAY MORNING THROUGH AFTERNOON.
KLEINSASSER
PREV DISCUSSION... /ISSUED 351 PM CDT SUN AUG 12 2012/
DISCUSSION...
SHORT RANGE...TONIGHT THROUGH TUESDAY
IN THE VERY SHORT TERM...SMALL CU BEGINNING TO DEVELOP ACROSS EXTREME
EASTERN KANSAS DUE TO DIURNAL MIXING AND WEAK ISENTROPIC LIFT...WITH
ADDITIONAL COLD CORE CU MOVING INTO NORTHEAST KANSAS. RIGHT
NOW...CU DEVELOPMENT IS NOT OVERLY IMPRESSIVE...HOWEVER SPC MESO
GRAPHICS INDICATED UNCAPPED ENVIRONMENT ACROSS SOUTHEAST KANSAS
AHEAD OF FRONTAL BOUNDARY CURRENTLY BISECTING CWA. HRRR AND RUC
BOTH GIVING INFINITESIMAL CHANCE OF THUNDERSTORMS BRUSHING EXTREME
SOUTHEASTERN CWA BETWEEN 21/12 AND 01/13...THUS WILL MAINTAIN LOW
CHANCE PO0PS IN THIS AREA. THE REST OF THE CWA WILL REMAIN DRY
OVERNIGHT.
NEXT CHANCE OF PRECIPITATION COMES LATE MONDAY NIGHT INTO TUESDAY
AS MCS ROLLS OFF LEE SLOPE OF ROCKIES. MITIGATING FACTOR FOR
COVERAGE WILL BE LOW LEVEL MOISTURE AS FRONT CURRENTLY MOVING
THROUGH PLAINS WILL SCOUR MOISTURE. ISENTROPIC LIFT/MOIST ADVECTION
IMPROVES BETWEEN 06 AND 12 UTC ON TUESDAY...SO WILL TREND POPS UP IN
THIS TIME PERIOD. DISCREPANCY AS WELL ON EXACT TRACK AND SOUTHERN
DEVELOPMENT OF STORMS BETWEEN SHORT TERM MODELS AND ENSEMBLES...WILL
LEAN TOWARD EC SOLUTION WHICH KEEPS BULK OF PRECIP IN CLOSE
PROXIMITY TO BETTER QG AND ISENTROPIC FORCING. MCS THAT ROLLS
THROUGH APPEARS TO LEAVE BOUNDARIES AROUND THAT WILL ALLOW
ADDITIONAL DEVELOPMENT TUES AFTERNOON EVENING AS RRQ OF UPPER LEVEL
JET DIVES FROM CENTRAL PLAINS INTO LOWER MISSISSIPPI VALLEY.
OVERALL...TRENDED LOWER ON QPF AS WELL GIVEN DROUGHT TRENDS.
TEMPERATURES WILL BE PLEASANT...WITH NARY A 100 DEGREE IN SITE FOR
SOME TIME. LARGE SCALE TROUGH ACROSS EASTERN TWO THIRDS OF NATION
WILL KEEP HEAT AT BAY FOR A WHILE. NORTH TO NORTHEAST FLOW MONDAY
WILL KEEP TEMPERATURES BELOW NORMAL FOR THE FIRST TIME IN A LONG
TIME. THAT TREND CONTINUES THROUGH THE SHORT TERM...AS CLOUDS AND
CONVECTION WILL KEEP THINGS A LITTLE COOLER ON TUESDAY AS WELL.
DRYNESS OF SOIL WILL ALLOW FOR SUPERADIABATIC HEATING...SO WILL
TREND TOWARD HIGHER END OF GUIDANCE FOR THE MOST PART.
MEDIUM RANGE...WEDNESDAY THROUGH SATURDAY
ANOTHER ROUND OF SHOWERS AND STORMS POSSIBLE WEDNESDAY NIGHT INTO
THURSDAY AS POTENT SHORT WAVE MOVING THROUGH NORTHERN STREAM DRIVES
ANOTHER FRONTAL SYSTEM THROUGH CWA. MOISTURE AGAIN WILL BE
LIMITED...SO LITTLE SUSPECT OF GREATER POPS PROBABILITIES BEING
GENERATED BY GEFS AND CONSENSUS BLENDS. GIVEN RECENT DROUGHT
TRENDS...TONED PROBABILITIES BACK A LITTLE. AFTER
THURSDAY...SURFACE RIDGING WILL BE IN PLACE THROUGH THE EARLY
WEEKEND...THEN UPPER RIDGING BEGINS TO BUILD BACK INTO CENTRAL
PLAINS AS EASTERN U.S. LARGE SCALE TROUGH EDGES EAST. THERE IS AN
OUTSIDE CHANCE OF CONVECTION RETURNING LATE IN THE WEEKEND DUE TO
ENHANCED RETURNED FLOW...BUT WILL LEAVE FORECAST DRY FOR NOW.
TEMPERATURES RETURN TO NORMAL ON WEDNESDAY HEAD OF AFOREMENTIONED
FRONTAL BOUNDARY...THEN ANOTHER SEVERAL DAYS OF BELOW NORMAL
TEMPERATURES IN STORE FOR THE CWA IN TERMS OF MAXIMUMS AND
MINIMUMS. USED A BLEND OF CONSENSUS FOR HIGHS AND GFS40 FOR
MINS...WHICH HAS BEEN DOING AMAZINGLY WELL GIVEN HOW POORLY IT HAS
HANDLED MAX TEMPERATURES OF LATE.
SF
PREV DISCUSSION... /ISSUED 1222 PM CDT SUN AUG 12 2012/
AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
VFR CONDITIONS EXPECTED TO PREVAIL THRU THE FORECAST VALID PERIOD.
ISOLATED CONVECTION IS EXPECTED ALONG A COLD FRONT LATE THIS
AFTERNOON...WITH A FEW STORMS POSSIBLY AFFECTING SOUTHEAST KANSAS.
FRONTAL TIMING SUGGESTS THIS ACTIVITY WILL BE JUST SOUTH OF KCNU
THOUGH INCLUDED A VCTS FOR A FEW HOURS AT START OF FORECAST.
OTHERWISE GUSTY NORTH-NORTHWEST WINDS BEHIND THE FRONT WILL
DIMINISH THIS EVENING...ONLY TO PICK UP AGAIN AFTER SUNRISE ON
MONDAY MORNING ACROSS THE AREA.
KED
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 62 90 62 87 / 0 0 20 30
HUTCHINSON 60 87 62 88 / 0 0 20 30
NEWTON 60 86 60 88 / 0 0 20 30
ELDORADO 61 89 58 88 / 0 0 10 30
WINFIELD-KWLD 64 91 62 88 / 0 0 10 30
RUSSELL 57 87 60 88 / 0 0 30 30
GREAT BEND 58 87 61 88 / 0 0 30 30
SALINA 59 87 61 89 / 0 0 20 30
MCPHERSON 59 87 62 88 / 0 0 20 30
COFFEYVILLE 64 93 60 88 / 0 0 0 30
CHANUTE 62 89 58 88 / 0 0 0 30
IOLA 62 88 58 87 / 0 10 0 30
PARSONS-KPPF 64 90 60 88 / 0 0 0 30
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PADUCAH KY
529 PM CDT MON AUG 13 2012
.UPDATE...
ISSUED AT 529 PM CDT MON AUG 13 2012
FROM A MESOSCALE PERSPECTIVE...THE CURRENT CONVECTION REMAINS IN A
QUASI-STEADY STATE. THE BEST THETA-E CONVERGENCE VIA LAPS DATA IS
BEING FOCUSED IN A ROUGHLY A 25 NAUTICAL MILE WIDE BAND ALONG THE
SURFACE FRONT...BUT WEST OF THE NORTH/SOUTH ORIENTED 2300 J2/K2
CAPE MAXIMUM ORIENTED NEAR INTERSTATE 55 IN SOUTHWEST ILLINOIS AND
SOUTHEAST MISSOURI. THE MAIN SURFACE LOW /WAVE/ IS OVER JACKSON
COUNTY ILLINOIS...AND WILL LIKELY MOVE NEAR MOUNT VERNON IN THE
NEXT COUPLE OF HOURS. UNFORTUNATELY...THE CORE OF THE HIGHER CAPE
VALUES HAS NOT BEEN PROGRESSING FURTHER NORTH...WHICH MAY LIMIT
UNCONDITIONAL SURFACE BASED INSTABILITY THROUGH THE EVENING.
THE HRRR AND 12KM NAM GUIDANCE APPEAR TO A HAVE A GENERAL IDEA OF
THE PROGRESSION OF THE FRONT AND OVERALL SYSTEM...BUT THE
PROJECTED FORECAST REFLECTIVITY GRIDS ARE ABOUT 80 TO 100 NM TOO
FAR TO THE SOUTHWEST. THE TIMING FOR SURFACE BASED CONVECTION WILL
BECOME MORE LIMITED THROUGH 00Z TUESDAY /7 PM CDT/ TONIGHT.
THERE IS A SUGGESTION IN THE 12KM NAM-WRF GUIDANCE THAT ENOUGH
FORECAST SHEAR /30-40KTS BULK SHEAR IN THE ZERO TO SIX KILOMETER
LAYER/ MOVING UP FROM EAST OF THE MISSISSIPPI RIVER IN WEST
TENNESSEE BETWEEN 23Z AND 02Z...THAT SOME MORE STORM DEVELOPMENT
AND ORGANIZATION MAY OCCUR TO SUSTAIN UPDRAFTS AS WEAK LOW LEVEL
WIND TRY TO INCREASE AT OR ABOVE THE DEVELOPING BOUNDARY LAYER
INVERSION AHEAD OF THE COLD FRONT. LOW LEVEL SHEAR IS QUITE
WEAK...SO ANY SUPPORT FOR RENEWED CONVECTION INTO WESTERN KENTUCKY
WILL HAVE TO COME FROM MID/UPPER LEVEL FORCING AND INSTABILITY.
THE KNQA VAD WIND PROFILE HAS BEEN SHOWING SOME INCREASE IN WINDS
NEAR 20KFT AS THE BASE OF THE UPPER WAVE. WHETHER THAT WILL BE
ENOUGH AS THE SHORTWAVE MOVES ACROSS WESTERN KY WILL BE THE 20
THOUSAND DOLLAR QUESTION.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 124 PM CDT MON AUG 13 2012
BOUNDARY AT 18Z WAS STILL OVER SOUTHEAST MISSOURI. AIRMASS
CONTINUES TO DESTABILIZE...WITH SOME ENHANCED CU SEEN NW OF
KCGI UP TOWARD PERRYVILLE MO. WILL CONTINUE TO MONITOR THIS
CORRIDOR AND POINTS EAST THROUGH THE AFTERNOON AND EARLY
EVENING FOR A FEW STRONG TO POSSIBLY SEVERE STORMS. OTHERWISE
THE ACTIVITY WILL PUSH EAST TONIGHT. QUIET WEATHER EXPECTED
TUESDAY AND TUESDAY NIGHT WITH VERY WEAK HIGH PRESSURE
FORECAST TO BUILD INTO THE AREA.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 124 PM CDT MON AUG 13 2012
BY WEDNESDAY...UPPER HEIGHTS BEGIN TO RISE ACROSS THE AREA AND THIS
SHOULD RESULT IN WARMER TEMPERATURES...BUT WE SHOULD REMAIN RIGHT
AROUND NORMAL. THE SFC HIGH THAT WILL BE OVER THE AREA ON WEDNESDAY
WILL CONTINUE PROGRESSING TO THE EAST AND BY WEDNESDAY NIGHT...OUR
AREA SHOULD BE IN SOUTHERLY FLOW...WITH A WARM FRONT DEVELOPING TO
OUR SOUTH THAT WILL INCH SLOWLY TO THE NORTH. HOWEVER...WE WILL
REMAIN DRY WEDNESDAY NIGHT.
BY 12Z THURSDAY...A COLD FRONT WILL STRETCH FROM THE GREAT LAKES TO
WEST TEXAS...AND BE MOVING EASTWARD ACROSS OUR AREA WITH TIME. BOTH
THE GFS AND ECMWF HAVE BEEN IN REALLY GOOD AGREEMENT WITH THE
PROGRESSION OF THIS FRONT. HOWEVER...THE GFS/ECMWF HAVE DEFINITELY
SLOWED DOWN EVEN MORE WITH THE ONSET OF PRECIP...AND ACTUALLY
INDICATE THAT MOST OF THURSDAY MIGHT END UP BEING FAIRLY DRY...WITH
OUR WESTERN SECTIONS HAVING THE BEST CHANCES BY LATER IN THE
AFTERNOON. THIS WILL MEAN THAT WE WILL PROBABLY SEE WARMER HIGHS ON
THURSDAY AS WELL. WITH HIGHS IN THE UPPER 80S/LOWER 90S AND
DEWPOINTS IN THE UPPER 60S/LOWER 70S...IT WILL DEFINITELY FEEL LIKE
SUMMER IS BACK. SO...WILL KEEP WITH MIDNIGHT SHIFTS THOUGHT OF
BREAKING THE THURSDAY TIME PERIOD INTO TWO...SHOWING BETTER CHANCES
DURING THE AFTERNOON. THE BULK OF THE RAIN WILL ARRIVE ON THURSDAY
NIGHT AS THE FRONT PASSES THROUGH...SO WILL CONTINUE WITH LIKELY
POPS.
BY 12Z FRIDAY...BOTH THE GFS/ECMWF/GEM HAVE THE FRONTAL BOUNDARY IN
OUR EASTERN COUNTIES OR JUST EAST OF THE AREA. BELIEVE WE WILL SEE
THE POSSIBILITY OF PRECIPITATION LINGERING FRIDAY MORNING MAINLY IN
THE SOUTHEASTERN HALF OF THE CWA. COULD ALMOST GO DRY FOR FRIDAY
AFTERNOON...BUT WITH THE MODELS TRENDING SLOWER WITH THIS
FRONT...WILL FORGO THAT FOR NOW.
FRIDAY NIGHT APPEARS DRY ATTM...AS HIGH PRESSURE BUILDS INTO THE
AREA FROM CANADA. MUCH COOLER TEMPERATURES SHOULD RESULT AS 850 MB
TEMPS DIVE INTO THE LOW TEENS BY SATURDAY. THIS SHOULD RESULT IN
TEMPERATURES THAT ARE WELL BELOW NORMAL. GIVEN THE VERY DRY AIR THAT
WILL LIKELY FILTER INTO THE REGION...HIGH TEMPERATURES WILL PROBABLY
END UP BEING HIGHER THAN WHAT THE CURRENT GUIDANCE NUMBERS ARE
SUGGESTING. THE GFS AND ECMWF INDICATE AN INCREASE IN
MOISTURE/PRECIPITATION AS EARLY AS SATURDAY NIGHT AND INTO
SUNDAY...AS SOME ENERGY WRAPS AROUND AN UPPER LOW IN EASTERN CANADA
AND DIVES DOWN INTO OUR AREA. THE ECMWF APPEARS TO BE FASTER AND A
LITTLE MORE GUNG HO ON THIS IDEA...SHOWING A MORE PRONOUNCED TROUGH
SWINGING THROUGH. WITH CURRENT MODEL DIFFERENCES...WILL LEAVE THINGS
DRY FOR THE WEEKEND AND MONDAY...UNTIL WE CAN OBTAIN SOME BETTER
CONSISTENCY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 529 PM CDT MON AUG 13 2012
MAIN CHALLENGE WITH THE 00Z TUESDAY TAF ISSUANCE WILL BE THE
TIMING AND EXTENT OF THE CONVECTION /SHOWERS AND THUNDERSTORMS/
OVER THE KPAH/KEVV/KOWB TAF SITES THIS EVENING. AT THIS
TIME...PLAN TO UTILIZED MVFR CEILINGS AND VISIBILITIES WITH ANY
EXPECTED STORMS AHEAD OF THE FRONT...WITH VFR CEILINGS OR CLOUD
BASES FOLLOWING FRONTAL PASSAGE. THERE WILL BE A SIX TO EIGHT HOUR
PERIOD OF SCATTERED CLOUDS /NO CEILINGS/ A FEW HOURS AFTER THE
COLD FRONTAL PASSAGE. PLAN TO REINTRODUCE VFR CEILINGS FOR
KCGI/KPAH WITH THE DIURNAL STRATOCUMULUS IN THE 11Z-13Z TUESDAY
TIME FRAME...WITH LATE MORNING /15Z OR LATER/ VFR AT KEVV/KOWB.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...SMITH
AVIATION...SMITH
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
1127 PM EDT TUE AUG 14 2012
.SYNOPSIS...
A WEAK WARM FRONT WILL LIFT ACROSS THE AREA TONIGHT. AT THE SAME
TIME...LOW PRESSURE WILL CONTINUE TO DEVELOP OVER THE DELMARVA
PENINSULA. SHOWERS AND THUNDERSTORMS WILL BE LIKELY ON WEDNESDAY.
THIS WILL WILL VERY GRADUALLY LIFT NORTHEASTWARD ON
WEDNESDAY...AND MOVE TO A POSITION NEAR THE SOUTHERN TIP OF NOVA
SCOTIA LATE THURSDAY. A COLD FRONT WILL THEN PUSH ACROSS THE
REGION FRIDAY AFTERNOON OR EVENING. WEAK LOW PRESSURE MAY DEVELOP
JUST OFFSHORE ALONG THIS FRONT OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
UPDATE...HAVE UPPED POP ACROSS SWRN ZONES OF THE CWA BASED ON
RADAR TRENDS. AS EXPECTED THE MID LVL WARM FNT IS PUSHING NWD INTO
THE CWA. THIS WAA IS LEADING TO ISOLD SHRA ACROSS SULLIVAN AND
GRAFTON COUNTIES ATTM. THIS ACTIVITY WILL CONTINUE TO LIFT INTO
THE CWA...AS MORE ORGANIZED CONVECTION WORKS IN FROM THE W EARLY
THIS MORNING. THE LATEST HRRR EVOLUTION LOOKS TO BE A GOOD
STARTING POINT...BUT TIMING APPEARS TO BE A LITTLE SLOW IN THE
MODEL. THE FCST MAINTAINS A CLOSER ARRIVAL TO MIDNIGHT THAN TO
12Z.
PREVIOUS DISCUSSION...A BROAD SHORT WAVE TROUGH CENTERED OVER
THE GREAT LAKES WILL GRADUALLY APPROACH NEW ENGLAND TONIGHT. AT
THE SAME TIME...A WEAK WARM FRONT WILL PASS NORTHWARD ACROSS THE
AREA OVERNIGHT. POP-UP SHOWERS AND PERHAPS AN ISOLD RUMBLE ACROSS
THE NRN NH AND WRN ME MOUNTAINS AND FOOTHILLS SHOULD GRADUALLY
WANE THIS EVENING WITH THE LOSS OF DAYTIME HEATING. WE EXPECT MOST
OF THE NIGHT TO REMAIN DRY...BUT CAN/T RULE OUT A COUPLE OF
SHOWERS HERE AND THERE...ESPECIALLY OVER WESTERN ZONES. PATCHY FOG
IS LIKELY ONCE AGAIN. LOW TEMPS ARE A CONSENSUS BETWEEN THE
MET/MAV/NAM GUIDANCE.
&&
.SHORT TERM /WEDNESDAY NIGHT/...
SHORT WAVE TROUGH WILL CONTINUE TO APPROACH ON WEDNESDAY WHILE LOW
LEVEL MOISTURE INCREASES. 500MB TEMPS WILL COOL TO BETWEEN -10C
AND -12C AND SHOULD RESULT IN SOME MODEST INSTABILITY STARTING
EARLY IN THE DAY WITH LITTLE IN THE WAY OF CAPPING. THEREFORE...WE
EXPECT CONVECTIVE SHOWERS TO DEVELOP DURING THE MORNING AWAY FROM
THE COAST...WITH NUMEROUS SHOWERS AND THUNDERSTORMS PRETTY MUCH
EVERYWHERE BY EARLY AFTERNOON. FLOW ALOFT IS WEAK AND MBE VECTORS
ARE SHORT. THEREFORE...SHOULD BE SOME SLOW MOVING STORMS WITH THE
ATTENDANT THREAT FOR LOCALLY BRIEF TORRENTIAL DOWNPOURS. GIVEN THE
LACK OF DEEP LAYER SHEAR...THE THREAT FOR SEVERE WIND AND/OR HAIL
APPEARS QUITE LOW AT THIS TIME.
AS THE UPPER LEVEL TROUGH AMPLIFIES AND SWINGS OVER THE REGION
WEDNESDAY NIGHT...THE CHANCE FOR SHOWERS ALONG WITH A FEW
THUNDERSTORMS WILL BE QUITE HIGH. LIKELY POPS FOR NOW...BUT MAY
NEED CATEGORICAL EVENTUALLY.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
UPPER LEVEL TROUGH MAY TRY TO CLOSE OFF OVERHEAD FOR A TIME ON
THURSDAY...AND THIS MAY MEAN SHOWERS FOR A GOOD PART OF THE DAY.
BEST CHANCE FOR WIDESPREAD PRECIP WILL BE IN THE MORNING. MAY NEED
TO CONSIDER RAISING POPS FOR MUCH OF THE AREA...HOWEVER.
RETURN FLOW AHEAD OF ANOTHER APPROACHING FRONT WILL PRODUCE WARM
AND MUGGY CONDITIONS ON FRIDAY. THE COLD FRONT WILL MOVE ACROSS
THE CWA DURING THE EVENING HOURS ON FRIDAY. IF THE FRONT SPEEDS UP
A LITTLE BIT THEN WE COULD SEE SOME STRONGER THUNDERSTORMS AS MAX
INSTABILITY WOULD COINCIDE WITH PEAK DIURNAL HEATING. COOLER AND
DRIER CONDITIONS WILL FOLLOW THE FRONT ON SATURDAY AND SUNDAY.
EXPECT TEMPERATURES TO RETURN TO NEAR NORMAL AND DEWPOINTS WILL
FALL UNDER NORTHWESTERLY FLOW.
BROAD UPPER LEVEL TROUGH OVER THE MIDDLE OF THE COUNTRY ON MONDAY
AND TUESDAY WILL PUT MAINE AND NEW HAMPSHIRE UNDER SOUTHWESTERLY
FLOW ALOFT. THIS WILL LIKELY PRODUCE UNSETTLED CONDITIONS AS WE
HEAD INTO THE EARLY PART OF THE WORK WEEK.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM /THROUGH WEDNESDAY NIGHT/...LOCAL MVFR IN FOG OR PATCHY
STRATUS OVERNIGHT...BUT THE BULK OF THE NIGHT LOOKS TO BE VFR. ON
WEDNESDAY...SHOWERS AND THUNDERSTORMS SHOULD DEVELOP BETWEEN 15Z
AND 18Z...PERHAPS A TAD LATER ON THE COAST. LOCAL IFR CONDITIONS
EXPECTED WITH THOSE. SAME GOES FOR WED NIGHT.
LONG TERM /THURSDAY MORNING THROUGH SUNDAY/...MVFR/IFR CONDITIONS
IN RAIN AND FOG AS COLD FRONT MOVES THROUGH THE REGION WILL
IMPROVE TO VFR LATE THURSDAY MORNING. ANOTHER FRONTAL BOUNDARY
WILL BRING CONDITIONS DOWN TO MVFR/IFR AGAIN LATE FRIDAY BEFORE
HIGH PRESSURE BRINGS VFR CONDITIONS BACK FOR SATURDAY AND SUNDAY.
&&
.MARINE...
SHORT TERM /THROUGH WEDNESDAY/...WIND AND WAVES TO REMAIN BELOW
SCA LEVEL. VSBY RESTRICTIONS POSSIBLE TONIGHT AND WEDNESDAY MAINLY
IN FOG AND HAZE. VSBY RESTRICTIONS POSSIBLE IN RAIN WEDNESDAY
NIGHT AND THURSDAY.
LONG TERM...NO FLAGS EXPECTED. EXPECT SOME LINGERING FOG AND
SHOWERS THURSDAY UNTIL FRONTAL BOUNDARY MOVES NORTH AND EAST OF
THE REGION LATE DAY. OTHERWISE...NO ISSUES NOTED.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
LEGRO
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
1047 PM EDT TUE AUG 14 2012
.SYNOPSIS...
A WEAK WARM FRONT WILL LIFT ACROSS THE AREA TONIGHT. AT THE SAME
TIME...LOW PRESSURE WILL CONTINUE TO DEVELOP OVER THE DELMARVA
PENINSULA. SHOWERS AND THUNDERSTORMS WILL BE LIKELY ON WEDNESDAY.
THIS WILL WILL VERY GRADUALLY LIFT NORTHEASTWARD ON
WEDNESDAY...AND MOVE TO A POSITION NEAR THE SOUTHERN TIP OF NOVA
SCOTIA LATE THURSDAY. A COLD FRONT WILL THEN PUSH ACROSS THE
REGION FRIDAY AFTERNOON OR EVENING. WEAK LOW PRESSURE MAY DEVELOP
JUST OFFSHORE ALONG THIS FRONT OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
UPDATE...HAVE UPPED POP ACROSS SWRN ZONES OF THE CWA BASED ON
RADAR TRENDS. AS EXPECTED THE MID LVL WARM FNT IS PUSHING NWD INTO
THE CWA. THIS WAA IS LEADING TO ISOLD SHRA ACROSS SULLIVAN AND
GRAFTON COUNTIES ATTM. THIS ACTIVITY WILL CONTINUE TO LIFT INTO
THE CWA...AS MORE ORGANIZED CONVECTION WORKS IN FROM THE W EARLY
THIS MORNING. THE LATEST HRRR EVOLUTION LOOKS TO BE A GOOD
STARTING POINT...BUT TIMING APPEARS TO BE A LITTLE SLOW IN THE
MODEL. THE FCST MAINTAINS A CLOSER ARRIVAL TO MIDNIGHT THAN TO
12Z.
PREVIOUS DISCUSSION...A BROAD SHORT WAVE TROUGH CENTERED OVER
THE GREAT LAKES WILL GRADUALLY APPROACH NEW ENGLAND TONIGHT. AT
THE SAME TIME...A WEAK WARM FRONT WILL PASS NORTHWARD ACROSS THE
ARE OVERNIGHT. POP-UP SHOWERS AND PERHAPS AN ISOLD RUMBLE ACROSS
THE NRN NH AND WRN ME MOUNTAINS AND FOOTHILLS SHOULD GRADUALLY
WANE THIS EVENING WILL THE LOSS OF DAYTIME HEATING. WE EXPECT MOST
OF THE NIGHT TO REMAIN DRY...BUT CAN/T RULE OUT A COUPLE OF
SHOWERS HERE AND THERE...ESPECIALLY OVER WESTERN ZONES. PATCHY FOG
IS LIKELY ONCE AGAIN. LOW TEMPS ARE A CONSENSUS BETWEEN THE
MET/MAV/NAM GUIDANCE.
&&
.SHORT TERM /WEDNESDAY NIGHT/...
SHORT WAVE TROUGH WILL CONTINUE TO APPROACH ON WEDNESDAY WHILE LOW
LEVEL MOISTURE INCREASES. 500MB TEMPS WILL COOL TO BETWEEN -10C
AND -12C AND SHOULD RESULT IN SOME MODEST INSTABILITY STARTING
EARLY IN THE DAY WITH LITTLE IN THE WAY OF CAPPING. THEREFORE...WE
EXPECT CONVECTIVE SHOWERS TO DEVELOP DURING THE MORNING AWAY FROM
THE COAST...WITH NUMEROUS SHOWERS AND THUNDERSTORMS PRETTY MUCH
EVERYWHERE BY EARLY AFTERNOON. FLOW ALOFT IS WEAK AND MBE VECTORS
ARE SHORT. THEREFORE...SHOULD BE SOME SLOW MOVING STORMS WILL THE
ATTENDANT THREAT FOR LOCALLY BRIEF TORRENTIAL DOWNPOURS. GIVEN THE
LACK OF DEEP LAYER SHEAR...THE THREAT FOR SEVERE WIND AND/OR HAIL
APPEARS QUITE LOW AT THIS TIME.
AS THE UPPER LEVEL TROUGH AMPLIFIES AND SWINGS OVER THE REGION
WEDNESDAY NIGHT...THE CHANCE FOR SHOWERS ALONG WITH A FEW
THUNDERSTORMS WILL BE QUITE HIGH. LIKELY POPS FOR NOW...BUT MAY
NEED CAT EVENTUALLY.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
UPPER LEVEL TROUGH MAY TRY TO CLOSE OFF OVERHEAD FOR A TIME ON
THURSDAY...AND THIS MAY MEAN SHOWERS FOR A GOOD PART OF THE DAY.
BEST CHANCE FOR WIDESPREAD PRECIP WILL BE IN THE MORNING. MAY NEED
TO CONSIDER RAISING POPS FOR MUCH OF THE AREA...HOWEVER.
RETURN FLOW AHEAD OF ANOTHER APPROACHING FRONT WILL PRODUCE WARM
AND MUGGY CONDITIONS ON FRIDAY. THE COLD FRONT WILL MOVE ACROSS
THE CWA DURING THE EVENING HOURS ON FRIDAY. IF THE FRONT SPEEDS UP
A LITTLE BIT THEN WE COULD SEE SOME STRONGER THUNDERSTORMS AS MAX
INSTABILITY WOULD COINCIDE WITH PEAK DIURNAL HEATING. COOLER AND
DRIER CONDITIONS WILL FOLLOW THE FRONT ON SATURDAY AND SUNDAY.
EXPECT TEMPERATURES TO RETURN TO NEAR NORMAL AND DEWPOINTS WILL
FALL UNDER NORTHWESTERLY FLOW.
BROAD UPPER LEVEL TROUGH OVER THE MIDDLE OF THE COUNTRY ON MONDAY
AND TUESDAY WILL PUT MAINE AND NEW HAMPSHIRE UNDER SOUTHWESTERLY
FLOW ALOFT. THIS WILL LIKELY PRODUCE UNSETTLED CONDITIONS AS WE
HEAD INTO THE EARLY PART OF THE WORK WEEK.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM /THROUGH WEDNESDAY NIGHT/...LOCAL MVFR IN FOG OR PATCHY
STRATUS OVERNIGHT...BUT THE BULK OF THE NIGHT LOOKS TO BE VFR. ON
WEDNESDAY...SHOWERS AND THUNDERSTORMS SHOULD DEVELOP BETWEEN 15Z
AND 18Z...PERHAPS A TAD LATER ON THE COAST. LOCAL IFR CONDITIONS
EXPECTED WITH THOSE. SAME GOES FOR WED NIGHT.
LONG TERM /THURSDAY MORNING THROUGH SUNDAY/...MVFR/IFR CONDITIONS
IN RAIN AND FOG AS COLD FRONT MOVES THROUGH THE REGION WILL
IMPROVE TO VFR LATE THURSDAY MORNING. ANOTHER FRONTAL BOUNDARY
WILL BRING CONDITIONS DOWN TO MVFR/IFR AGAIN LATE FRIDAY BEFORE
HIGH PRESSURE BRINGS VFR CONDITIONS BACK FOR SATURDAY AND SUNDAY.
&&
.MARINE...
SHORT TERM /THROUGH WEDNESDAY/...WIND AND WAVES TO REMAIN BELOW
SCA LEVEL. VSBY RESTRICTIONS POSSIBLE TONIGHT AND WEDNESDAY MAINLY
IN FOG AND HAZE. VSBY RESTRICTIONS POSSIBLE IN RAIN WEDNESDAY
NIGHT AND THURSDAY.
LONG TERM...NO FLAGS EXPECTED. EXPECT SOME LINGERING FOG AND
SHOWERS THURSDAY UNTIL FRONTAL BOUNDARY MOVES NORTH AND EAST OF
THE REGION LATE DAY. OTHERWISE...NO ISSUES NOTED.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
LEGRO
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1153 PM EDT TUE AUG 14 2012
.SYNOPSIS...
ISSUED AT 312 PM EDT TUE AUG 14 2012
AN AREA OF HIGH PRESSURE WILL PASS SOUTH OF MICHIGAN TONIGHT INTO
WEDNESDAY. THIS WILL PROVIDE PARTLY CLOUDY SKIES AND LIGHT WINDS
OVERNIGHT. AS THE HIGH MOVES EAST OF THE AREA WEDNESDAY SOUTHERLY
WINDS WILL BRING HIGHS INTO THE LOWER 80S INLAND OF LAKE MICHIGAN
BY MID AFTERNOON. A COLD FRONT WILL MOVE THROUGH THE AREA THURSDAY
WITH SHOWERS AND THUNDERSTORMS. BEHIND THE FRONT EXPECT COOLER
WEATHER INTO THE WEEKEND WITH ONLY A SLIGHT CHANCE OF SHOWERS EACH
DAY.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 312 PM EDT TUE AUG 14 2012
THE MAIN ISSUE WITH THIS FORECAST IS THE THREAT FOR STRONG
THUNDERSTORMS ON THURSDAY WITH THE COLD FRONT. THERE IS ALSO A
LESSER ISSUE WITH THE SHOWERS ASSOCIATED WITH THE WEAK FRONT
MOVING THROUGH THE AREA THIS EVENING.
AS FOR THE EVENING SHOWERS... THE RAP MODEL SOUNDING SHOW THE
EQUILIBRIUM LEVEL NEAR 36,000 FT AGL FOR LATE AFTERNOON AND
EVENING WITH CAPES NEAR 1000 J/KG NORTH AND EAST OF GRR. HOWEVER
THOSE SAME SOUNDING SHOW DEW POINT DEPRESSIONS OF OVER 25C BETWEEN
700 AND 400 MB. AS IT TURNS OUT THE SHOWERS ARE ACTUALLY TOPPING
OUT BELOW 20000 FT AGL. THESE SHOWERS ARE ON A WEAK SHORTWAVE AND
THE SURFACE COLD FRONT MOVING ACROSS CENTRAL LOWER MICHIGAN. ALL
OF THIS SHOULD BE EAST OF THE CWA BY SUNSET.
AS FOR THE CONVECTION ON THE COLD FRONT THURSDAY... SEEMS THE
MODELS ARE SIMILAR NOW IN THE TIMING OF THE FRONT... DURING THE
MID TO LATE AFTERNOON. THAT WOULD SUPPORT THE IDEA OF STRONGER
STORMS AS WOULD THE FORECAST OF A STRENGTHENING LOW LEVEL JET HOWEVER
THE CORE OF THE SPEED MAX IS NORTH AND EAST OF GRR THURSDAY
AFTERNOON WHICH MEANS SPEED DIVERGENCE OVER MOST OF THE CWA DURING
THE PRIME THUNDERSTORM DEVELOPMENT TIME. ALSO NOT SO GOOD IS THE
NAM IS SHOWING UPPER CONVERGENCE OVER SURFACE CONVERGENCE AT 18Z
THURSDAY. RATHER NOT CONDUCIVE FOR STRONG STORMS EITHER. THAT IS
BECAUSE GRR IS UNDER THE RIGHT EXIT REGION OF THE UPPER JET. BY
EVENING AS THE CONVECTION REACHES EASTERN LOWER MICHIGAN THE
DYNAMICS IMPROVE. BESIDE ALL OF THAT THERE WILL BE CONSIDERABLE
CLOUDS OVER THE CWA WITH THE FRONT WHICH WILL HOLD DOWN THE
SURFACE TEMPS TOO. SO MY SPIN IS WE WILL SEE A LINE OF
STRENGTHENING STORMS OVER OUR EASTERN CWA DURING THE AFTERNOON.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 345 PM EDT TUE AUG 14 2012
MAIN FORECAST CHALLENGE IS RAIN CHANCES. MAIN CHANGE WAS TO FEATURE
AT LEAST SLIGHT CHANCE POPS FOR ALMOST THE ENTIRE PERIOD.
MODELS FEATURE STRONGLY CYCLONIC FLOW ALOFT ACROSS THE GREAT LAKES
DURING THIS PERIOD. THIS IS ASSOCIATED WITH A PERSISTENT UPPER LOW
CENTERED OVER HUDSON BAY. SEVERAL REINFORCING POT VORT MAXES
ROTATING AROUND THE LOW SHOULD HELP TO ANCHOR IT AND FORCE MULTIPLE
EPISODES OF RAIN SHOWERS OVER OUR AREA. THE SPECIFICS ON
PRECIPITATION FREQUENCY...TIMING AND AMOUNTS ALL REMAIN VERY
UNCERTAIN. HOWEVER...THE HIGHLY UNSETTLED OVERALL PATTERN JUSTIFIES
AT LEAST SLIGHT CHANCE POPS THROUGHOUT. TEMPERATURES WILL BE
SIGNIFICANTLY COOLER THAN NORMAL WITH SOME DAYS POSSIBLY STRUGGLING
TO GET INTO THE 60S DEPENDING ON THE TIMING AND INTENSITY OF
PRECIPITATION THAT OCCURS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1153 PM EDT TUE AUG 14 2012
STILL CONCERNED ABOUT THE POSSIBILITY OF SOME PATCHY IFR/LIFR
CATEGORY FOG 08Z-13Z. HOWEVER WILL NOT FCST CONDITIONS AS LOW AS
LAST NIGHT SINCE THE BOUNDARY LAYER DRIED OUT A BIT ON TUESDAY AND
THERE IS SOME MID AND HIGH LEVEL CLOUDINESS PASSING THROUGH.
OUTSIDE OF ANY AREAS OF RADIATION FOG TONIGHT AND EARLY
WEDNESDAY... VFR CONDITIONS AND LIGHT WINDS ARE EXPECTED TO
PREVAIL.
&&
.MARINE...
ISSUED AT 312 PM EDT TUE AUG 14 2012
WINDS WILL BE CONDUCIVE TO HIGHER WAVES THURSDAY AHEAD OF THE
FRONT AND EVEN MORE SO BEHIND THE COLD FRONT THURSDAY NIGHT. WE
WILL LIKELY HAVE TO ISSUE A SMALL CRAFT ADVISORY AND BEACH HAZARD
STATEMENTS.
&&
.HYDROLOGY...
ISSUED AT 312 PM EDT TUE AUG 14 2012
RIVERS ARE RUNNING WELL BELOW ADVISORY LEVELS AND RAINFALL
THURSDAY WILL NOT BE ENOUGH TO CHANGE THAT.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...TJT
AVIATION...MEADE
HYDROLOGY...WDM
MARINE...WDM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
759 PM EDT TUE AUG 14 2012
.SYNOPSIS...
ISSUED AT 312 PM EDT TUE AUG 14 2012
AN AREA OF HIGH PRESSURE WILL PASS SOUTH OF MICHIGAN TONIGHT INTO
WEDNESDAY. THIS WILL PROVIDE PARTLY CLOUDY SKIES AND LIGHT WINDS
OVERNIGHT. AS THE HIGH MOVES EAST OF THE AREA WEDNESDAY SOUTHERLY
WINDS WILL BRING HIGHS INTO THE LOWER 80S INLAND OF LAKE MICHIGAN
BY MID AFTERNOON. A COLD FRONT WILL MOVE THROUGH THE AREA THURSDAY
WITH SHOWERS AND THUNDERSTORMS. BEHIND THE FRONT EXPECT COOLER
WEATHER INTO THE WEEKEND WITH ONLY A SLIGHT CHANCE OF SHOWERS EACH
DAY.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 312 PM EDT TUE AUG 14 2012
THE MAIN ISSUE WITH THIS FORECAST IS THE THREAT FOR STRONG
THUNDERSTORMS ON THURSDAY WITH THE COLD FRONT. THERE IS ALSO A
LESSER ISSUE WITH THE SHOWERS ASSOCIATED WITH THE WEAK FRONT
MOVING THROUGH THE AREA THIS EVENING.
AS FOR THE EVENING SHOWERS... THE RAP MODEL SOUNDING SHOW THE
EQUILIBRIUM LEVEL NEAR 36,000 FT AGL FOR LATE AFTERNOON AND
EVENING WITH CAPES NEAR 1000 J/KG NORTH AND EAST OF GRR. HOWEVER
THOSE SAME SOUNDING SHOW DEW POINT DEPRESSIONS OF OVER 25C BETWEEN
700 AND 400 MB. AS IT TURNS OUT THE SHOWERS ARE ACTUALLY TOPPING
OUT BELOW 20000 FT AGL. THESE SHOWERS ARE ON A WEAK SHORTWAVE AND
THE SURFACE COLD FRONT MOVING ACROSS CENTRAL LOWER MICHIGAN. ALL
OF THIS SHOULD BE EAST OF THE CWA BY SUNSET.
AS FOR THE CONVECTION ON THE COLD FRONT THURSDAY... SEEMS THE
MODELS ARE SIMILAR NOW IN THE TIMING OF THE FRONT... DURING THE
MID TO LATE AFTERNOON. THAT WOULD SUPPORT THE IDEA OF STRONGER
STORMS AS WOULD THE FORECAST OF A STRENGTHENING LOW LEVEL JET HOWEVER
THE CORE OF THE SPEED MAX IS NORTH AND EAST OF GRR THURSDAY
AFTERNOON WHICH MEANS SPEED DIVERGENCE OVER MOST OF THE CWA DURING
THE PRIME THUNDERSTORM DEVELOPMENT TIME. ALSO NOT SO GOOD IS THE
NAM IS SHOWING UPPER CONVERGENCE OVER SURFACE CONVERGENCE AT 18Z
THURSDAY. RATHER NOT CONDUCIVE FOR STRONG STORMS EITHER. THAT IS
BECAUSE GRR IS UNDER THE RIGHT EXIT REGION OF THE UPPER JET. BY
EVENING AS THE CONVECTION REACHES EASTERN LOWER MICHIGAN THE
DYNAMICS IMPROVE. BESIDE ALL OF THAT THERE WILL BE CONSIDERABLE
CLOUDS OVER THE CWA WITH THE FRONT WHICH WILL HOLD DOWN THE
SURFACE TEMPS TOO. SO MY SPIN IS WE WILL SEE A LINE OF
STRENGTHENING STORMS OVER OUR EASTERN CWA DURING THE AFTERNOON.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 345 PM EDT TUE AUG 14 2012
MAIN FORECAST CHALLENGE IS RAIN CHANCES. MAIN CHANGE WAS TO FEATURE
AT LEAST SLIGHT CHANCE POPS FOR ALMOST THE ENTIRE PERIOD.
MODELS FEATURE STRONGLY CYCLONIC FLOW ALOFT ACROSS THE GREAT LAKES
DURING THIS PERIOD. THIS IS ASSOCIATED WITH A PERSISTENT UPPER LOW
CENTERED OVER HUDSON BAY. SEVERAL REINFORCING POT VORT MAXES
ROTATING AROUND THE LOW SHOULD HELP TO ANCHOR IT AND FORCE MULTIPLE
EPISODES OF RAIN SHOWERS OVER OUR AREA. THE SPECIFICS ON
PRECIPITATION FREQUENCY...TIMING AND AMOUNTS ALL REMAIN VERY
UNCERTAIN. HOWEVER...THE HIGHLY UNSETTLED OVERALL PATTERN JUSTIFIES
AT LEAST SLIGHT CHANCE POPS THROUGHOUT. TEMPERATURES WILL BE
SIGNIFICANTLY COOLER THAN NORMAL WITH SOME DAYS POSSIBLY STRUGGLING
TO GET INTO THE 60S DEPENDING ON THE TIMING AND INTENSITY OF
PRECIPITATION THAT OCCURS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 759 PM EDT TUE AUG 14 2012
THE MAIN AVIATION CONCERN IS THE FOG POTENTIAL LATE TONIGHT AND
EARLY WEDNESDAY MORNING. THE SET UP DOES NOT LOOK QUITE AS GOOD AS
LAST NIGHT SINCE THE BOUNDARY LAYER HAS DRIED OUT TODAY... BUT THE
CURRENT SFC DEW PT IN THE LOWER 60S NEAR LK MI AT MKG MAY ALLOW
SOME THICKER IFR/LIFR FOG TO DEVELOP THERE AFTER MIDNIGHT. THE
THREAT FOR IFR/LIFR FOG OVERNIGHT APPEARS TO BE LESS THE FARTHER
EAST YOU GO AS THE DEW PT AT LAN AND JXN IS CURRENTLY IN THE MID
50S. OUTSIDE OF ANY AREAS OF FOG TONIGHT AND EARLY WEDNESDAY...
VFR CONDITIONS AND LIGHT WINDS ARE EXPECTED TO PREVAIL.
&&
.MARINE...
ISSUED AT 312 PM EDT TUE AUG 14 2012
WINDS WILL BE CONDUCIVE TO HIGHER WAVES THURSDAY AHEAD OF THE
FRONT AND EVEN MORE SO BEHIND THE COLD FRONT THURSDAY NIGHT. WE
WILL LIKELY HAVE TO ISSUE A SMALL CRAFT ADVIOSRY AND BEACH HAZARD
STATEMENTS.
&&
.HYDROLOGY...
ISSUED AT 312 PM EDT TUE AUG 14 2012
RIVERS ARE RUNNING WELL BELOW ADVISORY LEVELS AND RAINFALL
THURSDAY WILL NOT BE ENOUGH TO CHANGE THAT.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...TJT
AVIATION...MEADE
HYDROLOGY...WDM
MARINE...WDM
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
752 PM EDT TUE AUG 14 2012
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 359 PM EDT TUE AUG 14 2012
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NW FLOW OVER THE
UPR GRT LKS BTWN TROF CENTERED NEAR HUDSON BAY AND UPR RDG JUST OFF
THE CA COAST. STRONGER SHRTWV RESPONSIBLE FOR YDAYS SHRA IS OVER
LOWER MI AND MOVING INTO SE ONTARIO. ANOTHER WEAKER DISTURBANCE
ROTATING ARND THE ONTARIO VORTEX IS PRESENT JUST N OF THE MN/ONTARIO
BORDER AND HEADING ESEWD. 12Z INL/GRB RAOBS SHOW MODEST LLVL MSTR
CONFINED BLO INVRN ARND H7 AND VERY DRY AIR IN THE MID/UPR LVLS.
SINCE THE SHRTWV JUST N OF THE BORDER AND ACCOMPANYING H3 JET MAX
ARE ON TRACK TO STAY N OF THE CWA WITH ACCOMPANYING H5 CAD/DPVA/
DEEP LYR QVECTOR CNVGC JUST BRUSHING THE NRN TIER...LATEST NAM/RUC
FCST SDNGS HINT MID LVL INVRN/DRY AIR WL REMAIN IN PLACE. BUT WITH
THE LLVL MSTR/SFC DEWPTS AS HI AS 55 TO 60 OVER THE E THAT IS
CAUSING SOME CU TO DVLP AS THE SFC WARMS TO THE CONVECTIVE TEMP IN
THE LO 70S...A FEW SHRA HAVE DVLPD OVER THE E ALONG LK BREEZE BNDRYS
WHERE COOLING AT H5 IS A BIT MORE PRONOUNCED AND WHERE THE 12Z CNDN
MODEL HINTED SHRA WOULD BE MOST LIKELY TO FORM. BEHIND THIS
DISTURBANCE...A SHRTWV RDG/ SFC HI IS PRESENT OVER MANITOBA/FAR NW
ONTARIO...BRINGING TRANQUIL WX TO THIS AREA IN CONCERT WITH FAIRLY
DRY AIRMASS DEPICTED BY THE 12Z THE PAS MANITOBA RAOB NEAR LK
WINNIPEG. ANOTHER POTENT SHRTWV IS DIGGING SEWD THRU BRITISH
COLUMBIA.
LATE THIS AFTN...MAINTAINED LO CHC POPS IN THE AREAS OVER THE
CENTRAL AND E MOST LIKELY TO BE IMPACTED BY THE LK BREEZE CNVGC.
HOWEVER...WITH WARM MID LVLS AND ENVIRONMENTAL LAPSE RATES NEAR
MOIST ADIABATIC...ANY SHRA/TS WL BE ISOLD/SCT AND ON THE RELATIVELY
WEAK SIDE WITH DEEP LYR SHEAR NO HIER THAN 25-30 KTS.
TNGT...WITH LOSS OF DAYTIME HEATING AND APRCH OF SHRTWV RDG/DNVA/
DEEP LYR QVECTOR DVGC...EXPECT ANY SHRA/TS TO DIMINISH DURING THE
EVNG. WITH LGT WINDS/DRYING ALF ASSOCIATED WITH INCOMING HI PRES...
EXPECT ENUF DIURNAL COOLING TO SUPPORT GOING PATCHY FOG FCST OVER
THE INTERIOR E HALF...WHERE SFC DEWPTS ARE HIER THIS AFTN.
WED...HI PRES OVER UPR MI IN THE MRNG IS PROGGED TO DRIFT TO THE E
THRU THE DAY AS SHRTWV RDG MOVES TO THE E IN ADVANCE OF DISTURBANCE
NOW IN BRITISH COLUMBIA AND THAT IS FCST TO REACH THE NRN PLAINS BY
00Z THU. ALTHOUGH THE SHARPEST DPVA/DEEP LYR QVECTOR CNVGC IN
ADVANCE OF THIS DISTURBANCE IS FCST TO REMAIN TO THE W THRU 00Z...
THE BULK OF THE NUMERICAL GUIDANCE GENERATES SOME GENERALLY LGT PCPN
OVER THE W HALF IN THE AFTN. HOWEVER...SINCE THE NAM/GFS FCST SDNGS
SHOW WARM MID LVL TEMPS IN THE ABSENCE OF ANY DYNAMIC FORCING AND
HINT THAT LLVL MSTR RETURN IN ADVANCE OF THE SHRTWV WL BE MARGINAL
DUE TO DRYNESS OF AIRMASS IN THE NRN PLAINS THIS AFTN...OPTED TO
RESTRICT POPS TO JUST THE FAR W LATER IN THE DAY WHERE THE GFS/NAM
SHOW HIER H85 DEWPTS NEAR 12C RETURNING TOWARD 00Z IN THE
STRENGTHENING SSW FLOW AHEAD OF THIS DISTURBANCE. WITH H85 TEMPS
RECOVERING TO ABOUT 13C OVER THE E TO 17C OVER THE W BY LATER IN THE
DAY...EXPECT HI TEMPS TO REACH THE 80S AT MOST PLACES AWAY FM LK MI
MODERATION.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 359 PM EDT TUE AUG 14 2012
WEDNESDAY NIGHT THROUGH THURSDAY...UPPER LEVEL LOW AND ASSOCIATED
SURFACE LOW OVER WESTERN ONTARIO WILL SHIFT SLOWLY EAST THROUGHOUT
THIS TIME PERIOD. AS THIS HAPPENS THE LOW WILL SWEEP A COLD FRONT
ACROSS THE AREA WEDNESDAY NIGHT THROUGH THURSDAY AS SHOWN BY
PLOTTING SURFACE WINDS/MSLP/H850 THETA E. MODELS ARE FAIRLY SIMILAR
ON TIMING AS THE FRONT IS EXPECTED TO FIRST MOVE INTO THE WESTERN
PORTION OF THE UPPER PENINSULA AROUND 06Z THURSDAY AND THEN REACHING
THE EASTERN UPPER PENINSULA AROUND 18Z THURSDAY. THE GFS IS SLIGHTLY
FASTER THAN THE EC/NAM AT BRINGING THE FRONT THROUGH THE
REGION...WITH THE PRECIP SHOWN TO START A COUPLE OF HOURS EARLIER.
THE 06Z RUN OF THE GFS IS SHOWING A TREND TOWARD SLOWING THE
PRECIPITATION...WHICH WOULD BE MORE IN LINE WITH THE PREVIOUSLY
MENTIONED MODELS. HAVE LEANED MORE TOWARD THE EC FOR TIMING. THE
BEST CHANCE FOR HEAVIER PRECIPITATION ALONG WITH THUNDERSTORMS WILL
BE ALONG AND JUST AHEAD OF THE COLD FRONT WEDNESDAY NIGHT INTO
THURSDAY MORNING AS THIS IS BEST COLLOCATION OF DEEPER MOISTURE AND
FORCING...AS SHOWN BY OVERLAYING 1000-500MB RH AND 500-300MB QDIV.
CAPE VALUES AHEAD OF THE SYSTEM ARE EXPECTED TO TOP OUT AROUND
500-600 J/KG OVER THE WESTERN U.P. DURING THE EVENING AND SLOWLY
DECREASE AS THE SYSTEM MOVES EAST LATER IN THE NIGHT. CAPE IN THE
HAIL GROWTH ZONE IS EXPECTED TO BE AROUND 100-200 J/KG. AS THE FRONT
REACHES THE U.P. DEEP LAYER SHEAR VALUES ARE EXPECTED TO BE PARALLEL
TO THE FRONT AT 30 TO 35 KNOTS ALONG AND JUST AHEAD OF
IT...INCREASING TO AROUND 50 KNOTS BEHIND THE FRONT. WITH THAT BEING
SAID...THE SEVERE WEATHER POTENTIAL APPEARS TO BE MARGINAL AT BEST
ACROSS MAINLY THE FAR WESTERN PORTION OF THE UPPER PENINSULA.
THURSDAY NIGHT THROUGH FRIDAY...HAVE KEPT SIMILAR FORECAST TREND
WITH DEVELOPING LAKE EFFECT RAIN SHOWERS ACROSS MAINLY CENTRAL AND
EASTERN PORTIONS OF THE U.P. AS THE UPPER LEVEL 500MB LOW AND
SURFACE LOW BECOME VERTICALLY STACKED NEAR JAMES BAY. THIS WILL
ALLOW AN UPPER LEVEL TROUGH TO EXTEND ACROSS MUCH OF THE GREAT LAKES
REGION KEEPING TEMPERATURES ALOFT COOL ENOUGH...2 TO 4 C AT
H850...TO KEEP THE CHANCE OF RAIN SHOWERS IN THE FORECAST. SURFACE
TEMPERATURES WILL BE AROUND 17C ALLOWING FOR A SURFACE TO H850 DELTA
T OF AROUND 13 TO 15 C. ALONG WITH THE CHANCE OF RAIN
SHOWERS...WINDS MAY ALSO BECOME FAIRLY STRONG ON LAKE SUPERIOR AS
WINDS AROUND H850 ARE EXPECTED TO BE AROUND 25 TO 30 KNOTS. THESE
WINDS SHOULD BE ABLE TO MIX DOWN TO THE LAKE SURFACE WITH UNSTABLE
CONDITIONS SET UP BY THE CAA BEHIND THE LOW.
FRIDAY NIGHT THROUGH TUESDAY...UPPER LEVEL LOW REMAINS FAIRLY
STATIONARY OVER JAMES BAY FRIDAY NIGHT INTO SATURDAY. BY SATURDAY
NIGHT THE GFS AND EC DIFFER ON THE UPPER LEVEL LOW PLACEMENT WITH
THE EC DRIFTING THE LOW NORTHWARD...WHILE THE GFS SINKS THE LOW
SOUTHWARD INTO CENTRAL ONTARIO. CONFIDENCE IS LOW ENOUGH AT THIS
POINT TO STICK WITH A CONSENSUS OF THE MODELS SOLUTIONS. WITH THAT
BEING SAID THE WEATHER PATTERN APPEARS AS THOUGH COOLER WEATHER WILL
LIKELY LINGER INTO AT LEAST THE FIRST PART OF NEXT WEEK WITH
INTERMITTENT CHANCES OF SHOWERS AS MINOR DISTURBANCES ROTATE AROUND
THE LOW. SUNDAY MAY BRING A SLIGHTLY BETTER CHANCE OF SHOWERS AS THE
GFS AND EC SHOW A SHORTWAVE PASSING THROUGH THE AREA...HOWEVER...AS
PREVIOUSLY MENTIONED CONSIDERABLE TIMING DIFFERENCES EXIST.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 751 PM EDT TUE AUG 14 2012
VFR CONDITIONS SHOULD PREVAIL AT ALL SITES THROUGH THE TAF PERIOD.
THERE IS A SMALL CHANCE THAT PATCHY FOG COULD DEVELOP AT SAW
OVERNIGHT...BUT CONDITIONS APPEAR DRY ENOUGH TO PREVENT ANY
FORMATION. HIGH CLOUDS WILL BEGIN TO FILTER IN FROM THE WEST ON
WEDNESDAY AS A TROUGH APPROACHES. SOME WARM ADVECTION MAY KICK OFF
ISOLATED SHOWERS BY LATE AFTERNOON AT IWD..OTHERWISE...CONDITIONS
SHOULD BE DRY AT ALL TAF SITES.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 359 PM EDT TUE AUG 14 2012
EXPECT LIGHT WINDS INTO WED MORNING AS AREA OF HI PRES CROSSES THE
UPPER GREAT LAKES. ONCE THE HI CENTER SHIFTS TO THE E AND A COLD
FRONT MOVES IN FROM THE W...WINDS WILL BECOME SSE AND PICK UP AS HI
AS 20 KTS. PLAN ON A SHARP WIND SHIFT TO THE NW LATE ON WED NIGHT/
THU FOLLOWING THIS FRONTAL PASSAGE. THE ARRIVAL OF MUCH COOLER AIR
IN THE WAKE OF THE FRONT OVER THE WARM WATERS OF LAKE SUPERIOR WILL
ALSO RESULT IN ENHANCED MIXING OVER THE LAKE WITH NW WINDS UP TO 30
KTS...STRONGEST ON THU AFTERNOON/EVENING OVER THE E HALF...WHERE
TERRAIN ENHANCES THIS FLOW. EXPECT THE STRONGER NW WINDS TO SLOWLY
SUBSIDE ON FRI THRU THE WEEKEND AS A WEAKER PRES GRADIENT MORE
TYPICAL OF AUG RETURNS TO THE UPPER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KEC
AVIATION...TK
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
416 PM EDT MON AUG 13 2012
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 407 PM EDT MON AUG 13 2012
WV LOOP AND RAOBS INDICATE UPPER TROUGHS FROM NORTHERN ONTARIO
THROUGH THE WESTERN GREAT LAKES REGION. STRONGEST SHORTWAVES IN
THE MEAN TROUGH ARE OVER NORTHERN ONTARIO AND ALSO SOUTHERN LOWER
MICHIGAN. SHORTWAVE BTWN THE TWO TROUGHS AND SFC TROUGH MERGED UP
WITH LAKE BREEZES OVR CNTRL UPR MICHIGAN EARLIER THIS AFTN TO KICK
OFF ISOLD SHRA AND STORMS. CONVECTIVE DEPTH WAS SHALLOW...BUT RADAR
ESTIMATED PRECIP AMOUNTS UP TO 1-1.5 INCHES SEEMED REASONABLE AS
STORM MOTION WAS SLOW AND EVEN TRIED TO BACKBUILD OVR EXTREME
SOUTH CENTRAL MARQUETTE COUNTY AS ONE STORM BRIEFLY BECAME A RIGHT
MOVER.
AS OF 19Z...THE MESS OF THE SYNOPTIC TROUGH AND LAKE BREEZE
CONVERGENCE BOUNDARY IS ORIENTED FM ROUGHLY WATERSMEET THROUGH JUST
NORTH OF CRYSTAL FALLS AND IRON MOUNTAIN AND EAST TOWARD NEWBERRY
AND SAULT STE MARIE. ISOLD-SCATTERED SHRA/TSRA ARE LOCATED ALONG THE
TROUGH WITH STORM MOTIONS GENERALLY ESE AROUND 15 MPH. BASED ON
RADAR TRENDS AND HRRR MODEL...HIGHLIGHTED HIGHEST POPS EARLY THIS
EVENING OVR SCNTRL UPR MICHIGAN...WITH DIMINISHING TREND BY LATE
EVENING DUE TO LOSS OF DAYTIME INSTABILITY AND LOW-LEVEL
CONVERGENCE. STILL...AT LEAST ISOLD SHRA/TSRA MAY TRY TO STICK
AROUND THROUGH EVEN AFTER MIDNIGHT IN THE FAR SCNTRL WITH LINGERING
WEAKER SHORTWAVE ENERGY OVERHEAD AND STEEPER MID-LEVEL LAPSE RATES
AND H85-H7 MOISTURE. ALL CONVECTION SHOULD BE OUT OF CWA BY LATE
TONIGHT. TEMPS OVER INTERIOR WEST MAY TRY TO FALL OFF INTO THE 40S
LATE TONIGHT WITH A LOWER PWAT MIN LOCATED THERE. A BIT OF WIND AND
POSSIBLE SCT-BKN MID CLOUDS SHOULD KEEP REST OF CWA IN THE 50S.
ON TUESDAY...DAY STARTS OFF WITH THE SCT-BKN MID CLOUDS WITH CU
BUILDUP BY LATE MORNING AS CONVECTIVE TEMPS ARE IN THE LOWER 70S.
SHORTWAVE ON BACK SIDE OF LARGER SCALE TROUGH IN CNTRL SASKATCHEWAN
AND/OR MANITOBA FCST TO SLIDE INTO CNTRL CWA BY MID AFTN. GIVEN
SIMILAR FCST SBCAPES IN THE 700-1000J/KG RANGE COULD SEE REPEAT
PERFORMANCE OF TODAY...OR AT LEAST SOMEWHAT SIMILAR...WITH
ISOLD-SCATTERED SHRA/TSRA FORMING SHORTLY AFTER CONVECTIVE TEMPS
ARE REACHED. MAIN DIFFERENCE IS THE SHORTWAVE IS NOT AS STRONG AND
LOW-LEVEL CONVERGENCE WILL BE STRICTLY DRIVEN BY LAKE BREEZES FM
LAKE SUPERIOR/LAKE MICHIGAN. MSLP/WIND PATTERN POINTS TO AREA BTWN
SAW-IMT-ESC STAND TO SEE BEST COVERAGE OF SHRA/TSRA. FREEZING LEVELS
AROUND 11KFT AGL AND H85-H7 WINDS FAIRLY SIMILAR TO TODAY AS
WELL...SO AGAIN COULD SEE SLOW MOVING STORMS WITH MAIN HAZARDS
LIGHTNING AND HEAVY DOWNPOURS. SMALL HAIL COULD ALSO OCCUR WITH
STRONGEST STORMS. CONVERGENCE WANES BY LATE AFTN SO KEPT WITH IDEA
THAT POPS WILL BE OUT OF THE CWA BY EARLY TUESDAY EVENING.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 407 PM EDT MON AUG 13 2012
TUESDAY NIGHT THROUGH WEDNESDAY AFTERNOON...THE UPPER LEVEL TROUGH
WITH AXIS EXTENDING SOUTHWARD FROM CENTRAL ONTARIO THROUGH THE
EASTERN HALF OF UPPER MI AND INTO THE WESTERN HALF OF LOWER MI WILL
SHIFT EASTWARD OVERNIGHT...REACHING THE LOWER GREAT LAKES BY
WEDNESDAY AFTERNOON. AS THIS TROUGH SHIFTS EASTWARD A SURFACE AND
WEAK UPPER LEVEL RIDGE WILL BUILD INTO THE UPPER GREAT LAKES
REGION...BRIEFLY BRINGING AND END TO THE CHANCES OF PRECIPITATION.
WEDNESDAY EVENING THROUGH FRIDAY NIGHT...AS THE SURFACE RIDGE AND
UPPER LEVEL RIDGE BEGIN TO SHIFT EASTWARD TO THE LOWER GREAT LAKES
ATTENTION WILL THEN TURN TO AN APPROACHING LOW PRESSURE SYSTEM
CENTERED OVER NORTHERN MN...WITH ASSOCIATED UPPER LEVEL TROUGH TO
THE WEST OF THE SURFACE LOW...INDICATED BY BOTH THE
EC/GFS...SUGGESTING THAT THE SURFACE LOW IS EXPECTED TO INTENSIFY.
THE LOW WILL PASS TO THE NORTH OF THE UPPER PENINSULA BY 12Z
THURSDAY AS IT DRAGS A COLD FRONT THROUGH INTO CENTRAL UPPER MI
AROUND THE SAME TIME AS INDICATED BY PLOTTING MSLP/850 THETA
E/SURFACE WINDS. THE MAIN AREA OF PRECIPITATION WILL LIKELY BE
PEGGED TO THE FRONT OF THE COLD FRONT AS THE FORCING APPEARS THE
GREATEST ALONG THIS AREA AS SHOWN BY PLOTTING 500-300MB DIVQ ALONG
WITH 1000-500 RH VALUES. MU CAPE VALUES AREA PROGGED TO BE AROUND
500-800 J/KG OVER MUCH OF THE AREA OVER THE WESTERN HALF OF THE AREA
AROUND 06Z SHIFTING TO THE EAST HALF AROUND 12Z THURSDAY. 0-6 KM
SHEAR VALUES ARE EXPECTED TO BE AROUND 30 TO 35 KNOTS AHEAD OF THE
FRONT WITH VALUES INCREASING TO AROUND 50 KNOTS ALONG AND BEHIND THE
FRONT. SHEAR VALUES BEING MARGINAL FOR SEVERE WEATHER AHEAD OF THE
FRONT ALONG WITH CAPE IN THE HAIL GROWTH ZONE AROUND 100-200 J/KG
WOULD INDICATE ONLY A MARGINAL THREAT OF HAIL. DCAPE VALUES ARE
FAIRLY LOW WITH VALUES AROUND 100-150 J/KG DUE TO A LACK OF DRY AIR
IN THE MID LEVEL. THURSDAY NIGHT THROUGH FRIDAY NIGHT THE UPPER
LEVEL TROUGH WILL REMAIN OVER UPPER MI...WHILE SHIFTING EVER SO
SLOWLY TO THE EAST AS THE SURFACE LOW PULLS OT THE NORTHEAST TO
WESTERN QUEBEC. THE COOLER AIR WRAPPING AROUND THE BACK SIDE OF THE
LOW ALONG WITH DECREASED TEMPERATURES ALOFT...AROUND 4 TO 6C AT
H850...WILL HELP TO INCREASE THE CHANCE OF LAKE EFFECT SHOWERS OVER
THOSE AREAS FAVORED BY NORTH WINDS. HAVE ALSO INCREASED THE WINDS
OVER THE CENTRAL AND EASTERN PORTIONS OF THE LAKE AS CAA KICKS
IN...EXPECT THE STRONGER WINDS TO MIX DOWN AS H850 WINDS ARE AROUND
35 KNOTS. WILL HAVE TO KEEP AN EYE ON THIS THROUGH LATER SHIFTS.
SATURDAY THROUGH MONDAY...BOTH THE EC AND GFS KEEP THE UPPER LEVEL
500MB TROUGH SITUATED OVER MUCH OF THE UPPER GREAT LAKES
REGION...HELPING TO KEEP ON AND OFF CHANCES OF SHOWERS IN THE
FORECAST THROUGH MONDAY AFTERNOON. THE BEST CHANCE OF RAIN SHOWERS
THROUGH THIS PERIOD WOULD BE MONDAY AS A SURFACE LOW APPROACHES THE
AREA FROM THE WEST. MOISTURE THROUGH THIS TIME PERIOD APPEARS TO BE
FAIRLY LIMITED AS A SURFACE HIGH WILL REMAIN JUST TO THE SOUTH OF
THE REGION KEEPING DRY WESTERLY WINDS PUSHING INTO THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 225 PM EDT MON AUG 13 2012
WEAK COLD FRONT COULD TRIGGER ADDITIONAL SHRA/TSRA AT SAW THIS
AFTERNOON. IWD AND CMX SHOULD REMAIN DRY. IFR/MVFR CONDITIONS WITH
THE SHRA/TSRA EARLY THIS AFTN AT SAW...BUT OTHERWISE SHOULD BE VFR
AT ALL THE TAF SITES. ONCE FRONT MOVES THROUGH LATER TODAY...EXPECT
SCT-BKN MID CLOUDS AT ALL TAF SITES TONIGHT INTO TUESDAY MORNING
WITH OVERALL LIGHT WINDS. IF SKIES CAN CLEAR OUT SOME TONIGHT MAY
SEE PATCHY FOG FORM AT SAW DUE TO THE ADDITIONAL MOISTURE FROM
SHRA/TSRA THAT OCCURRED EARLY THIS AFTN. SHOT AT ISOLATED SHRA ON
TUESDAY AT SAW BUT THIS WOULD BE AFTER THIS TAF PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 407 PM EDT MON AUG 13 2012
QUIET MARINE WEATHER THROUGH WEDNESDAY AS HIGH PRESSURE SLIDES
OVERHEAD. BY LATER THURSDAY...PASSAGE OF A STRONG COLD FRONT WILL
KICK UP NORTHWEST WINDS TO 25 KTS OVER MUCH OF THE LAKE. WINDS TO 30
KTS ARE EXPECTED OVER CENTRAL AND EASTERN SECTIONS AS COLDER AIRMASS
PUSHES ACROSS THE STILL WARMER WATERS OF LAKE SUPERIOR. THE UNSTABLE
PROFILE WILL LEAD TO BUILDING WAVES THURSDAY NIGHT INTO FRIDAY.
EXPECT THE STRONG WINDS AND HIGH WAVES TO CONTINUE INTO SATURDAY
BEFORE DIMINISHING WITH ARRIVAL OF HIGH PRESSURE. EXPECT THE HIGHER
WAVES TO LEAD TO AN INCREASED RISK OF RIP CURRENTS LATE THURSDAY
THROUGH FRIDAY ALONG THE BEACHES OF EASTERN LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...KEC
AVIATION...JLA
MARINE...JLA
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
331 PM EDT MON AUG 13 2012
.SYNOPSIS...
ISSUED AT 311 PM EDT MON AUG 13 2012
RAIN SHOWERS WILL CONTINUE INTO TONIGHT AS LOW PRESSURE MOVES
SOUTH OF LOWER MICHIGAN. FAIR WEATHER WILL FOLLOW FOR TUESDAY AND
WEDNESDAY BUT STRONG THUNDERSTORMS ARE POSSIBLE THURSDAY NIGHT AS
A COLD FRONT MOVES THROUGH.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 311 PM EDT MON AUG 13 2012
LOWERED POPS A BIT TONIGHT AND TUESDAY MORNING. DROPPED POPS FOR
TUESDAY AFTERNOON AND WEDNESDAY NIGHT.
RADAR TRENDS AND HRRR INDICATE THAT MOST OF THE SHOWERS WILL BE
ACROSS THE SOUTHERN HALF OF THE FORECAST AREA WITH MORE SCATTERED
RAIN SHOWERS ACROSS THE NORTH. ADJUSTED POPS TO REFLECT THIS AND
ADDED AREAS OF FOG AFTER MIDNIGHT GIVEN THE EXPECTED LIGHT WINDS
AND HIGH LOW LEVEL RH. LEFT THUNDER OUT OF THE FORECAST DUE TO
MARGINAL INSTABILITY BUT CANNOT RULE OUT AN ISOLATED THUNDERSTORM.
NAM AND GFS CROSS SECTIONS SHOW A QUICKER DEPARTURE OF THE DEEPER
RH ON TUESDAY...SO TRIMMED POPS FOR THE MORNING AND DROPPED THEM
FOR THE AFTERNOON FOR ALL ZONES.
WEAK SFC RIDGING MOVES IN FOR TUESDAY NIGHT AND WEDNESDAY BUT
UPPER TROUGH AMPLIFICATION WILL LEAD TO STRONG SFC COLD FRONT
MOVING TOWARDS LOWER MICHIGAN WEDNESDAY NIGHT. AT HIS POINT IT
APPEARS THE ST ROMS ALONG THE FRONT WILL HOLD OFF UNTIL LATER
THURSDAY...SO DROPPED POPS FOR WEDNESDAY NIGHT.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 311 PM EDT MON AUG 13 2012
MAIN FOCUS OF THE FCST CONTINUES TO BE THE STRONG FRONT EXPECTED TO
MOVE THROUGH THU/THU NIGHT. THE WEEKEND LOOKS COOL AND POTENTIALLY A
LITTLE UNSETTLED WITH TROUGHING HANGING OUT OVER THE REGION. NO REAL
CHANGES WERE MADE TO THE FCST.
PCPN CHANCES WILL BE GRADUALLY INCREASING AT THE BEGINNING OF THE
LONG TERM PERIOD ON THU. THIS OCCURS AS UPPER RIDGING MOVES EAST OF
THE AREA...AND THE STRONG UPPER SYSTEM CURRENTLY MOVING INTO NW
BRITISH COLUMBIA DIGS INTO THE REGION. MODELS CONTINUE TO INDICATE
THAT MOST OF THE PCPN WITH THE SFC FRONT WILL BE RIGHT ALONG AND
JUST BEHIND THE FRONT. THIS IS WHERE THE TAIL END OF THE UPPER
TROUGH AND SFC FRONT OVERLAP.
IT CONTINUES TO LOOK LIKE CLOUDS OUT AHEAD OF THE FRONT WILL
SUPPRESS DIURNAL INSTABILITY SOME. MODELS INDICATE THAT AT LEAST A
FEW HUNDRED J/KG OF ML CAPE WILL BE LIKELY...AND THE GFS /LIKELY
OVERDONE DUE TO SFC DEW POINTS/ SHOWS MORE POTENTIAL INSTABILITY.
DEEP LAYER SHEAR STILL LOOKS TO BE MARGINAL ALONG THE FRONT...WITH
MUCH BETTER VALUES POST-FRONTAL. WE STILL EXPECT THAT STRONG STORMS
WILL BE POSSIBLE DUE TO THE STRENGTH OF THE FRONT AND UPPER TROUGH
THAT COULD COMPENSATE FOR MARGINAL SHEAR AND INSTABILITY.
ONCE THE UPPER TROUGH SUPPORTING THE FRONT MOVES IN...IT LOOKS TO
BECOME ESTABLISHED OVER THE AREA THROUGH THE REMAINDER OF THE
PERIOD. WE WILL SEE SHORT WAVE ENERGY CONTINUE TO DIVE INTO THE MEAN
TROUGH OVER THE GREAT LAKES...HELPING TO REINFORCE IT. THIS WILL
KEEP A CHC OF MAINLY DIURNAL SHOWERS AROUND THROUGH NEXT MON. THE
AREA WILL SEE FALL-LIKE TEMPS IN THE 60S AND TO AROUND 70 FOR THE
WEEKEND. TEMPS WILL SLOWLY MODIFY INTO THE 70S BY MON NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 147 PM EDT MON AUG 13 2012
RAIN TRENDS AND FOG/STRATUS POTENTIAL ARE THE MAIN ITEMS OF CONCERN
WITH THIS SET OF FCSTS.
LIGHT RAIN/SHOWERS HAVE BEEN PUSHING THROUGH ALL MORNING LONG.
SOMEWHAT DRY LOW LEVELS HAVE LIMITED THE INTENSITY OF THE RAIN...
ALONG WITH THE CIGS AND VISBYS REMAINING HIGH. MODELS HAVE TRENDED
FURTHER SOUTH WITH THE ENTIRE SYSTEM. NO IT APPEARS BASED ON
UPSTREAM TRENDS IN CONDITIONS THAT ONLY THE I-94 TERMINALS MAY SEE
SOME MVFR CONDITIONS LATER THIS AFTERNOON AND EVENING. RAIN SHOULD
GRADUALLY END LATER THIS EVENING AND OVERNIGHT FROM WNW TO E/SE.
IFR IS LOOKING LIKELY AT MOST SITES LATER TONIGHT. MODELS ARE
INDICATING STRATUS MOVING IN ACROSS KJXN AND KLAN LATER TONIGHT. AT
THE OTHER SITES...THE RAIN AND CLOUDS LOOK TO CLEAR OUT. LIGHT WINDS
AND A MOIST LOW LEVEL ATMOSPHERE WILL LIKELY PRODUCE FOG AT THE
REMAINDER OF THE SITES.
FOG AND STRATUS WILL CLEAR/MIX OUT BY MID TUE MORNING. CUMULUS CAN
BE EXPECTED TO DEVELOP WITH CONTINUED LIGHT WINDS.
&&
.MARINE...
ISSUED AT 311 PM EDT MON AUG 13 2012
SOME FOG IS POSSIBLE ALONG THE COAST WHERE COOLER WATERS HAVE BEEN
STIRRED UP BY LAST WEEKS STORM. OTHERWISE...NO SIGNIFICANT WEATHER
IS EXPECTED UNTIL THURSDAY OR THURSDAY NIGHT WHEN A COLD FRONT
BRINGS THE CHANCE FOR STRONG THUNDERSTORMS.
&&
.HYDROLOGY...
ISSUED AT 311 PM EDT MON AUG 13 2012
RAINS TODAY AND TONIGHT SHOULD NOT AFFECT RIVER LEVELS. SOME
HEAVIER RAINS ARE POSSIBLE THURSDAY AND THURSDAY NIGHT WITH A HALF
TO AN INCH OF BASIN AVERAGE QPF POSSIBLE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS...OSTUNO
SHORT TERM...OSTUNO
LONG TERM...NJJ
AVIATION...NJJ
HYDROLOGY...OSTUNO
MARINE...OSTUNO
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
152 PM EDT MON AUG 13 2012
.AVIATION...
//DISCUSSION...
MESOSCALE WAVE IS LIFTING UP THROUGH SE MI AT THE MOMENT LEADING TO
ENHANCEMENT IN THE PRECIP SHIELD OVER THE STATE WHICH IS TIED TO THE
SURFACE LOW TO OUR SOUTH. SOME MODERATE SHOWERS WILL BE POSSIBLE FOR
MBS AND TO A LESSER EXTENT FNT THIS AFTERNOON. POINTS SOUTH WILL BE
MORE OF SCATTERED LIGHT SHOWERS. COVERAGE WILL INCREASE THROUGH THE
LATE EVENING AS AN UPPER LEVEL WAVE MOVES THROUGH THE REGION.
CEILINGS HAVE BEEN FLUCTUATING BETWEEN 3KFT-7KFT BUT IT LOOKS LIKELY
THAT 4500FT WILL BE MOST COMMON AND WILL LOWER THROUGH THE
EVENING/NIGHT. VISIBILITIES WILL DEGRADE OVERNIGHT AS WELL WITH
FOG/HAZE APPEARING TOWARD MORNING AS THE HEAVIER PRECIP WORKS EAST.
FOR DTW...CEILINGS WILL FLUCTUATE AROUND 5000FT THROUGH THE
AFTERNOON BEFORE DROPPING TO MVFR AFTER MIDNIGHT AND POSSIBLY IFR BY
MORNING. RAIN SHOWERS WILL INCREASE IN COVERAGE OVERNIGHT.
//DTW THRESHOLD THREATS...
* MEDIUM CONFIDENCE CEILINGS WILL BE BELOW 5000FT AT TIMES THIS
AFTERNOON WITH HIGHER CONFIDENCE OVERNIGHT.
&&
.PREV DISCUSSION...ISSUED 703 AM EDT MON AUG 13 2012
UPDATE...
MORNING SHOWERS HAVE POPPED UP OVER WESTERN MICHIGAN IN
CONJUNCTION WITH A SURGE OF HIGHER THETA E AIR. WHILE MUCH OF THIS
ACTIVITY IS QUICKLY DYING OUT AS IT APPROACHES THE WESTERN
CWA...THE SHOWERS APPROACHING THE SAGINAW VALLEY ARE HOLDING
TOGETHER FAIRLY WELL. THEREFORE WILL RAISE POPS DURING THE MORNING
HOURS GIVEN THE UPTICK IN ACTIVITY THIS MORNING. DESPITE THE
RAISED POPS THESE MORNING SHOWERS WILL BE ISOLATED AND LIGHT IN
NATURE...WITH LITTLE QPF OR A TRACE AMOUNT OF RAIN AS THEY PASS
THROUGH GIVEN THE LOW LEVEL DRY AIR IN PLACE. MAIN EVENT IS STILL
SLATED FOR LATER TODAY AND INTO TONIGHT AS 500 MB SHORTWAVE
EVIDENT ON WATER VAPOR APPROACHES FROM THE WEST.
PREV DISCUSSION...ISSUED 347 AM EDT MON AUG 13 2012
SHORT TERM...TODAY AND TONIGHT
A SURFACE LOW PRESSURE SYSTEM CURRENTLY OVER THE MID-MISSISSIPPI
VALLEY WILL TRACK EAST THROUGH THE NORTHERN OHIO VALLEY TODAY AND
TONIGHT. WHILE THE MODELS HAVE COME INTO BETTER AGREEMENT WITH
REGARDS TO THE TRACK OF THE SURFACE LOW...THERE IS STILL MAJOR
DISAGREEMENT WITH THE TIMING...EXTENT AND QPF AMOUNTS ASSOCIATED
WITH THE PRECIPITATION. THE GFS IS ONCE AGAIN THE POOREST PERFORMER
AS INITIALIZATION HAS WAY TOO MUCH PRECIPITATION IN AN AREA THAT IS
CURRENTLY DRY. WHILE THE NAM IS LESS BROAD BRUSHED WITH ITS QPF...IT
IS TOO SLOW IN PUSHING THE PRECIPITATION EAST AS INITIALIZATION HAS
ABSOLUTELY NO RAIN IN EASTERN ILLINOIS. THE CANADIAN MODEL OFFERS
LITTLE HELP AS IT TRACKS THE LOW THROUGH THE CENTRAL OHIO
VALLEY...THE ONLY MODEL THAT IS THIS FAR SOUTH. THE BEST MODEL
INITIALIZATION IS CURRENTLY THE 3KM HRRR MODEL WHICH UNFORTUNATELY
ONLY GOES OUT THROUGH 18Z WITH THE 03Z MODEL RUN. DESPITE THE TIMING
ISSUES THE NAM SEEMS TO HAVE A GOOD HANDLE ON THE PRECIPITATION
HEADING EAST...AS A GOOD CHUNK OF THE INITIAL SURGE OF RAIN IS
EATEN AWAY THIS AFTERNOON AS THE RAIN RUNS INTO THE ABUNDANT DRY AIR
OVER SOUTHEAST MICHIGAN SHOWN ON THE 00Z KDTX RAOB THANKS TO A DRY
UPPER LEVEL RIDGE CURRENTLY IN PLACE ACROSS THE CENTRAL GREAT LAKES.
DESPITE THE SURGE OF HIGHER THETA E AIR INTO THE AREA THIS AFTERNOON
THE DRY AIR MAY ERODE ENOUGH OF THE RAIN TO WARRANT KEEPING POPS AS
IS WITH THE BEST CHANCES OUT ACROSS THE WESTERN CWA GIVEN THE
SHORTER DISTANCE THE RAIN TRACKS THROUGH THE DRY AIR.
THIS INITIAL SURGE OF MOISTURE SHOULD MOISTEN UP THE ATMOSPHERE BY
THIS EVENING WITH A BETTER CHANCE FOR RAIN AS THE MID LEVEL TROUGH
SWINGS THROUGH THE CENTRAL GREAT LAKES WITH ASSISTANCE FROM UPPER
LEVEL DIVERGENCE ON THE RIGHT REAR OF A WEAK JET STREAK. THE ADDED
DYNAMICS AND MOISTENING UP SHOULD LEND ITSELF TO A PERIOD OF STEADY
RAIN ACROSS SOUTHEAST MICHIGAN TONIGHT...WITH EMBEDDED THUNDERSTORMS
AS MUCAPE VALUES GET TO A FEW HUNDRED J/KG AND SHOWALTERS FALL TO
AROUND ZERO. DESPITE THE PROLONGED PERIOD OF RAIN...QPF AMOUNTS
SHOULD NOT BE EXCESSIVE AS PORTRAYED BY THE NAM GIVEN THE MEAGER
INSTABILITY AND SURFACE LOW WELL TO OUR SOUTH AS DYNAMICS...WHILE
PRESENT...ARE NOT OVERLY IMPRESSIVE.
WITH PRECIPITATION NOT EXPECTED TO MAKE IT INTO THE REGION UNTIL THE
LATE MORNING AND EARLY AFTERNOON...HIGH TEMPERATURES SHOULD BE ABLE
TO GET INTO THE MIDDLE TO UPPER 70S GIVEN THE RELATIVELY WARM START
AFFORDED BY THE OVERNIGHT CLOUD COVER. RAIN AND ABUNDANT CLOUDS
SHOULD KEEP OVERNIGHT LOWS IN THE LOWER TO MIDDLE 60S.
LONG TERM...TUESDAY THROUGH SUNDAY
UPPER TROUGH AXIS AND BACK EDGE OF DEFORMATION WILL SLOWLY PUSH OUT
OF SOUTHEAST MICHIGAN DURING THE MORNING HOURS ON TUESDAY. POTENTIAL
FOR SHOWERS AND THUNDERSTORMS WILL THEREFORE BE HIGHEST IN THE
MORNING...WITH LOWER CHANCES BY AFTERNOON AND EARLY EVENING. CLOUD
COVER SHOULD HELP KEEP MAX TEMPS CONFINED TO THE 70S.
UPPER SHORTWAVE RIDGE WILL THEN CROSS OVER THE AREA TUESDAY NIGHT
AND WEDNESDAY...ALLOWING SURFACE HIGH PRESSURE CENTERED OVER THE
TENNESSEE VALLEY TO EXPAND NORTHWARD INTO THE AREA. DRY WEATHER IS
EXPECTED UNDER THE HIGH...WITH GOOD INSOLATION HELPING TO BOOST
TEMPS BACK INTO THE UPPER 70S TO LOW 80S.
UPPER WAVE ON WATER VAPOR NOW SOUTH OF ALASKA WILL TRACK EAST AND
ACROSS ONTARIO BY EARLY THURSDAY. THE WAVE WILL THEN LIFT NORTH
TOWARDS HUDSON BAY ON FRIDAY AND SATURDAY...FORMING A LARGE UPPER
LOW OVER EASTERN CANADA. THIS WILL KEEP MICHIGAN CONFINED WITHIN A
BROAD UPPER TROUGH THROUGH EARLY NEXT WEEK...WITH MAX TEMPS EXPECTED
TO RUN WELL BELOW NORMAL ON FRIDAY AND THROUGH THE WEEKEND.
A WARM FRONT WILL FIRST LIFT ACROSS LOWER MICHIGAN WEDNESDAY NIGHT
AS SURFACE LOW PRESSURE QUICKLY SPINS UP LEE OF THE ROCKIES AND
BEGINS TO TRACK EAST. NAM SHOWS ISENTROPIC ASCENT WILL INCREASE
OVERNIGHT...BUT SOUNDINGS INDICATE MOISTURE WILL BE LACKING IN THE
LOWER LEVELS TO WORK WITH THE FORCING. WITH LOW-LEVEL DRY AIR
NEEDING TO FIRST BE OVERCOME...THINK PRECIPITATION FOR THE MOST PART
WILL HOLD OFF UNTIL LATE THURSDAY WHEN LOW-LEVEL JET IS FINALLY ABLE
TO PUMP HIGHER MOISTURE UP INTO THE GREAT LAKES (1.75 INCHES PER
GFS)...AND A STRONG COLD FRONT APPROACHES. GFS/EURO/GEM SHOW
PRECIPITATION WILL MAINLY BE TIED TO THE FRONTAL PASSAGE...BUT
EXPECT A FAIRLY BROAD AREA OF RAIN/TSTORMS TO DEVELOP AS GOOD UPPER
DIVERGENCE BECOMES POSITIONED OVER THE FRONT AND FAIRLY HEALTHY
LOW-LEVEL JET FEEDS MOISTURE UP INTO THE AREA. ALSO CANNOT RULE OUT
THE POSSIBILITY OF AN MCS DEVELOPING OVERHEAD...OR MOVING INTO LOWER
MICHIGAN FROM UPSTREAM. SOUTHEAST MICHIGAN LOOKS TO PICK UP ANOTHER
0.25 TO 0.50 INCHES OF RAINFALL FROM THIS SYSTEM BEFORE IT EXITS TO
OUR EAST ON FRIDAY.
MARINE...
QUIET MARINE CONDITIONS WILL BE MAINTAINED THIS MORNING AS A WEAK
RIDGE OF HIGH PRESSURE TRACKS EAST OF THE CENTRAL GREAT LAKES. IN
ITS WAKE A LOW PRESSURE SYSTEM WILL TRACK ACROSS THE SOUTHERN GREAT
LAKES TONIGHT AND TUESDAY. THIS SYSTEM WILL ONCE AGAIN PROVIDE HIGH
CHANCES FOR RAIN AND THUNDERSTORMS DURING IT`S TRANSIT ACROSS THE
AREA. ANOTHER LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT WILL
THEN AFFECT THE AREA THURSDAY NIGHT AND FRIDAY. DESPITE THE ACTIVE
WEATHER PATTERN...WINDS AND WAVES SHOULD BE BELOW HEADLINE CRITERIA
THROUGH THE WORK WEEK.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....DRK
UPDATE.......KURIMSKI
SHORT TERM...KURIMSKI
LONG TERM....HLO
MARINE.......KURIMSKI
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
703 AM EDT MON AUG 13 2012
.UPDATE...
MORNING SHOWERS HAVE POPPED UP OVER WESTERN MICHIGAN IN
CONJUNCTION WITH A SURGE OF HIGHER THETA E AIR. WHILE MUCH OF THIS
ACTIVITY IS QUICKLY DYING OUT AS IT APPROACHES THE WESTERN
CWA...THE SHOWERS APPROACHING THE SAGINAW VALLEY ARE HOLDING
TOGETHER FAIRLY WELL. THEREFORE WILL RAISE POPS DURING THE MORNING
HOURS GIVEN THE UPTICK IN ACTIVITY THIS MORNING. DESPITE THE
RAISED POPS THESE MORNING SHOWERS WILL BE ISOLATED AND LIGHT IN
NATURE...WITH LITTLE QPF OR A TRACE AMOUNT OF RAIN AS THEY PASS
THROUGH GIVEN THE LOW LEVEL DRY AIR IN PLACE. MAIN EVENT IS STILL
SLATED FOR LATER TODAY AND INTO TONIGHT AS 500 MB SHORTWAVE
EVIDENT ON WATER VAPOR APPROACHES FROM THE WEST.
&&
.AVIATION...ISSUED 653 AM EDT MON AUG 13 2012
//DISCUSSION...
A WEAK RIDGE OF HIGH PRESSURE WILL RESIDE OVER SRN MI THIS MORNING.
WINDS WILL THUS REMAIN QUITE LIGHT THROUGH AT LEAST 15Z. A MID LEVEL
WAVE NOW TRACKING ACROSS THE UPPER MIDWEST WILL ROTATE INTO LOWER MI
THIS AFTERNOON...WHILE THE ASSOCIATED SURFACE LOW REMAINS WELL SOUTH
OF THE STATE. THIS SYSTEM WILL ONLY RESULT IN AN INCREASE IN CLOUDS
ABOVE 10K FT THIS MORNING DUE TO RESIDUAL DRY LOW LEVEL AIR OVER SRN
MI. HOWEVER A FEW SHOWERS MAY MAKE IT OVER MBS THIS MORNING...SO
WILL INCLUDE A TEMPO GROUP TO START THE TAF OUT...BUT SHOULD ONLY
RESULT IN A FEW RAINDROPS WITH LITTLE IF ANY MEASURABLE RAIN.
RAIN WILL THEN OVERSPREAD THE AREA THIS AFTERNOON AND WILL RESULT IN
A RATHER ABRUPT LOWERING IN CEILINGS AND VISIBILITY AS RAIN
INTENSIFIES DURING THE EVENING AND CONTINUE INTO THE OVERNIGHT
HOURS.
FOR DTW...THE APPROACH OF THE UPPER WAVE WILL PROVIDE A GOOD CHANCE
OF RAIN AFTER 20Z. CEILINGS WILL GRADUALLY LOWER DURING THE
DAY...BUT ARE NOT EXPECTED TO DROP BELOW 5000 FT UNTIL AFTER 00Z.
//DTW THRESHOLD THREATS...
* MEDIUM CONFIDENCE CEILINGS WILL DROP BELOW 5000 FT AFTER 02Z.
&&
.PREV DISCUSSION...ISSUED 347 AM EDT MON AUG 13 2012
SHORT TERM...TODAY AND TONIGHT
A SURFACE LOW PRESSURE SYSTEM CURRENTLY OVER THE MID-MISSISSIPPI
VALLEY WILL TRACK EAST THROUGH THE NORTHERN OHIO VALLEY TODAY AND
TONIGHT. WHILE THE MODELS HAVE COME INTO BETTER AGREEMENT WITH
REGARDS TO THE TRACK OF THE SURFACE LOW...THERE IS STILL MAJOR
DISAGREEMENT WITH THE TIMING...EXTENT AND QPF AMOUNTS ASSOCIATED
WITH THE PRECIPITATION. THE GFS IS ONCE AGAIN THE POOREST PERFORMER
AS INITIALIZATION HAS WAY TOO MUCH PRECIPITATION IN AN AREA THAT IS
CURRENTLY DRY. WHILE THE NAM IS LESS BROAD BRUSHED WITH ITS QPF...IT
IS TOO SLOW IN PUSHING THE PRECIPITATION EAST AS INITIALIZATION HAS
ABSOLUTELY NO RAIN IN EASTERN ILLINOIS. THE CANADIAN MODEL OFFERS
LITTLE HELP AS IT TRACKS THE LOW THROUGH THE CENTRAL OHIO
VALLEY...THE ONLY MODEL THAT IS THIS FAR SOUTH. THE BEST MODEL
INITIALIZATION IS CURRENTLY THE 3KM HRRR MODEL WHICH UNFORTUNATELY
ONLY GOES OUT THROUGH 18Z WITH THE 03Z MODEL RUN. DESPITE THE TIMING
ISSUES THE NAM SEEMS TO HAVE A GOOD HANDLE ON THE PRECIPITATION
HEADING EAST...AS A GOOD CHUNK OF THE INITIAL SURGE OF RAIN IS
EATEN AWAY THIS AFTERNOON AS THE RAIN RUNS INTO THE ABUNDANT DRY AIR
OVER SOUTHEAST MICHIGAN SHOWN ON THE 00Z KDTX RAOB THANKS TO A DRY
UPPER LEVEL RIDGE CURRENTLY IN PLACE ACROSS THE CENTRAL GREAT LAKES.
DESPITE THE SURGE OF HIGHER THETA E AIR INTO THE AREA THIS AFTERNOON
THE DRY AIR MAY ERODE ENOUGH OF THE RAIN TO WARRANT KEEPING POPS AS
IS WITH THE BEST CHANCES OUT ACROSS THE WESTERN CWA GIVEN THE
SHORTER DISTANCE THE RAIN TRACKS THROUGH THE DRY AIR.
THIS INITIAL SURGE OF MOISTURE SHOULD MOISTEN UP THE ATMOSPHERE BY
THIS EVENING WITH A BETTER CHANCE FOR RAIN AS THE MID LEVEL TROUGH
SWINGS THROUGH THE CENTRAL GREAT LAKES WITH ASSISTANCE FROM UPPER
LEVEL DIVERGENCE ON THE RIGHT REAR OF A WEAK JET STREAK. THE ADDED
DYNAMICS AND MOISTENING UP SHOULD LEND ITSELF TO A PERIOD OF STEADY
RAIN ACROSS SOUTHEAST MICHIGAN TONIGHT...WITH EMBEDDED THUNDERSTORMS
AS MUCAPE VALUES GET TO A FEW HUNDRED J/KG AND SHOWALTERS FALL TO
AROUND ZERO. DESPITE THE PROLONGED PERIOD OF RAIN...QPF AMOUNTS
SHOULD NOT BE EXCESSIVE AS PORTRAYED BY THE NAM GIVEN THE MEAGER
INSTABILITY AND SURFACE LOW WELL TO OUR SOUTH AS DYNAMICS...WHILE
PRESENT...ARE NOT OVERLY IMPRESSIVE.
WITH PRECIPITATION NOT EXPECTED TO MAKE IT INTO THE REGION UNTIL THE
LATE MORNING AND EARLY AFTERNOON...HIGH TEMPERATURES SHOULD BE ABLE
TO GET INTO THE MIDDLE TO UPPER 70S GIVEN THE RELATIVELY WARM START
AFFORDED BY THE OVERNIGHT CLOUD COVER. RAIN AND ABUNDANT CLOUDS
SHOULD KEEP OVERNIGHT LOWS IN THE LOWER TO MIDDLE 60S.
LONG TERM...TUESDAY THROUGH SUNDAY
UPPER TROUGH AXIS AND BACK EDGE OF DEFORMATION WILL SLOWLY PUSH OUT
OF SOUTHEAST MICHIGAN DURING THE MORNING HOURS ON TUESDAY. POTENTIAL
FOR SHOWERS AND THUNDERSTORMS WILL THEREFORE BE HIGHEST IN THE
MORNING...WITH LOWER CHANCES BY AFTERNOON AND EARLY EVENING. CLOUD
COVER SHOULD HELP KEEP MAX TEMPS CONFINED TO THE 70S.
UPPER SHORTWAVE RIDGE WILL THEN CROSS OVER THE AREA TUESDAY NIGHT
AND WEDNESDAY...ALLOWING SURFACE HIGH PRESSURE CENTERED OVER THE
TENNESSEE VALLEY TO EXPAND NORTHWARD INTO THE AREA. DRY WEATHER IS
EXPECTED UNDER THE HIGH...WITH GOOD INSOLATION HELPING TO BOOST
TEMPS BACK INTO THE UPPER 70S TO LOW 80S.
UPPER WAVE ON WATER VAPOR NOW SOUTH OF ALASKA WILL TRACK EAST AND
ACROSS ONTARIO BY EARLY THURSDAY. THE WAVE WILL THEN LIFT NORTH
TOWARDS HUDSON BAY ON FRIDAY AND SATURDAY...FORMING A LARGE UPPER
LOW OVER EASTERN CANADA. THIS WILL KEEP MICHIGAN CONFINED WITHIN A
BROAD UPPER TROUGH THROUGH EARLY NEXT WEEK...WITH MAX TEMPS EXPECTED
TO RUN WELL BELOW NORMAL ON FRIDAY AND THROUGH THE WEEKEND.
A WARM FRONT WILL FIRST LIFT ACROSS LOWER MICHIGAN WEDNESDAY NIGHT
AS SURFACE LOW PRESSURE QUICKLY SPINS UP LEE OF THE ROCKIES AND
BEGINS TO TRACK EAST. NAM SHOWS ISENTROPIC ASCENT WILL INCREASE
OVERNIGHT...BUT SOUNDINGS INDICATE MOISTURE WILL BE LACKING IN THE
LOWER LEVELS TO WORK WITH THE FORCING. WITH LOW-LEVEL DRY AIR
NEEDING TO FIRST BE OVERCOME...THINK PRECIPITATION FOR THE MOST PART
WILL HOLD OFF UNTIL LATE THURSDAY WHEN LOW-LEVEL JET IS FINALLY ABLE
TO PUMP HIGHER MOISTURE UP INTO THE GREAT LAKES (1.75 INCHES PER
GFS)...AND A STRONG COLD FRONT APPROACHES. GFS/EURO/GEM SHOW
PRECIPITATION WILL MAINLY BE TIED TO THE FRONTAL PASSAGE...BUT
EXPECT A FAIRLY BROAD AREA OF RAIN/TSTORMS TO DEVELOP AS GOOD UPPER
DIVERGENCE BECOMES POSITIONED OVER THE FRONT AND FAIRLY HEALTHY
LOW-LEVEL JET FEEDS MOISTURE UP INTO THE AREA. ALSO CANNOT RULE OUT
THE POSSIBILITY OF AN MCS DEVELOPING OVERHEAD...OR MOVING INTO LOWER
MICHIGAN FROM UPSTREAM. SOUTHEAST MICHIGAN LOOKS TO PICK UP ANOTHER
0.25 TO 0.50 INCHES OF RAINFALL FROM THIS SYSTEM BEFORE IT EXITS TO
OUR EAST ON FRIDAY.
MARINE...
QUIET MARINE CONDITIONS WILL BE MAINTAINED THIS MORNING AS A WEAK
RIDGE OF HIGH PRESSURE TRACKS EAST OF THE CENTRAL GREAT LAKES. IN
ITS WAKE A LOW PRESSURE SYSTEM WILL TRACK ACROSS THE SOUTHERN GREAT
LAKES TONIGHT AND TUESDAY. THIS SYSTEM WILL ONCE AGAIN PROVIDE HIGH
CHANCES FOR RAIN AND THUNDERSTORMS DURING IT`S TRANSIT ACROSS THE
AREA. ANOTHER LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT WILL
THEN AFFECT THE AREA THURSDAY NIGHT AND FRIDAY. DESPITE THE ACTIVE
WEATHER PATTERN...WINDS AND WAVES SHOULD BE BELOW HEADLINE CRITERIA
THROUGH THE WORK WEEK.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
UPDATE.......KURIMSKI
AVIATION.....KURIMSKI
SHORT TERM...KURIMSKI
LONG TERM....HLO
MARINE.......KURIMSKI
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
653 AM EDT MON AUG 13 2012
.AVIATION...
//DISCUSSION...
A WEAK RIDGE OF HIGH PRESSURE WILL RESIDE OVER SRN MI THIS MORNING.
WINDS WILL THUS REMAIN QUITE LIGHT THROUGH AT LEAST 15Z. A MID LEVEL
WAVE NOW TRACKING ACROSS THE UPPER MIDWEST WILL ROTATE INTO LOWER MI
THIS AFTERNOON...WHILE THE ASSOCIATED SURFACE LOW REMAINS WELL SOUTH
OF THE STATE. THIS SYSTEM WILL ONLY RESULT IN AN INCREASE IN CLOUDS
ABOVE 10K FT THIS MORNING DUE TO RESIDUAL DRY LOW LEVEL AIR OVER SRN
MI. HOWEVER A FEW SHOWERS MAY MAKE IT OVER MBS THIS MORNING...SO
WILL INCLUDE A TEMPO GROUP TO START THE TAF OUT...BUT SHOULD ONLY
RESULT IN A FEW RAINDROPS WITH LITTLE IF ANY MEASURABLE RAIN.
RAIN WILL THEN OVERSPREAD THE AREA THIS AFTERNOON AND WILL RESULT IN
A RATHER ABRUPT LOWERING IN CEILINGS AND VISIBILITY AS RAIN
INTENSIFIES DURING THE EVENING AND CONTINUE INTO THE OVERNIGHT
HOURS.
FOR DTW...THE APPROACH OF THE UPPER WAVE WILL PROVIDE A GOOD CHANCE
OF RAIN AFTER 20Z. CEILINGS WILL GRADUALLY LOWER DURING THE
DAY...BUT ARE NOT EXPECTED TO DROP BELOW 5000 FT UNTIL AFTER 00Z.
//DTW THRESHOLD THREATS...
* MEDIUM CONFIDENCE CEILINGS WILL DROP BELOW 5000 FT AFTER 02Z.
&&
.PREV DISCUSSION...ISSUED 347 AM EDT MON AUG 13 2012
SHORT TERM...TODAY AND TONIGHT
A SURFACE LOW PRESSURE SYSTEM CURRENTLY OVER THE MID-MISSISSIPPI
VALLEY WILL TRACK EAST THROUGH THE NORTHERN OHIO VALLEY TODAY AND
TONIGHT. WHILE THE MODELS HAVE COME INTO BETTER AGREEMENT WITH
REGARDS TO THE TRACK OF THE SURFACE LOW...THERE IS STILL MAJOR
DISAGREEMENT WITH THE TIMING...EXTENT AND QPF AMOUNTS ASSOCIATED
WITH THE PRECIPITATION. THE GFS IS ONCE AGAIN THE POOREST PERFORMER
AS INITIALIZATION HAS WAY TOO MUCH PRECIPITATION IN AN AREA THAT IS
CURRENTLY DRY. WHILE THE NAM IS LESS BROAD BRUSHED WITH ITS QPF...IT
IS TOO SLOW IN PUSHING THE PRECIPITATION EAST AS INITIALIZATION HAS
ABSOLUTELY NO RAIN IN EASTERN ILLINOIS. THE CANADIAN MODEL OFFERS
LITTLE HELP AS IT TRACKS THE LOW THROUGH THE CENTRAL OHIO
VALLEY...THE ONLY MODEL THAT IS THIS FAR SOUTH. THE BEST MODEL
INITIALIZATION IS CURRENTLY THE 3KM HRRR MODEL WHICH UNFORTUNATELY
ONLY GOES OUT THROUGH 18Z WITH THE 03Z MODEL RUN. DESPITE THE TIMING
ISSUES THE NAM SEEMS TO HAVE A GOOD HANDLE ON THE PRECIPITATION
HEADING EAST...AS A GOOD CHUNK OF THE INITIAL SURGE OF RAIN IS
EATEN AWAY THIS AFTERNOON AS THE RAIN RUNS INTO THE ABUNDANT DRY AIR
OVER SOUTHEAST MICHIGAN SHOWN ON THE 00Z KDTX RAOB THANKS TO A DRY
UPPER LEVEL RIDGE CURRENTLY IN PLACE ACROSS THE CENTRAL GREAT LAKES.
DESPITE THE SURGE OF HIGHER THETA E AIR INTO THE AREA THIS AFTERNOON
THE DRY AIR MAY ERODE ENOUGH OF THE RAIN TO WARRANT KEEPING POPS AS
IS WITH THE BEST CHANCES OUT ACROSS THE WESTERN CWA GIVEN THE
SHORTER DISTANCE THE RAIN TRACKS THROUGH THE DRY AIR.
THIS INITIAL SURGE OF MOISTURE SHOULD MOISTEN UP THE ATMOSPHERE BY
THIS EVENING WITH A BETTER CHANCE FOR RAIN AS THE MID LEVEL TROUGH
SWINGS THROUGH THE CENTRAL GREAT LAKES WITH ASSISTANCE FROM UPPER
LEVEL DIVERGENCE ON THE RIGHT REAR OF A WEAK JET STREAK. THE ADDED
DYNAMICS AND MOISTENING UP SHOULD LEND ITSELF TO A PERIOD OF STEADY
RAIN ACROSS SOUTHEAST MICHIGAN TONIGHT...WITH EMBEDDED THUNDERSTORMS
AS MUCAPE VALUES GET TO A FEW HUNDRED J/KG AND SHOWALTERS FALL TO
AROUND ZERO. DESPITE THE PROLONGED PERIOD OF RAIN...QPF AMOUNTS
SHOULD NOT BE EXCESSIVE AS PORTRAYED BY THE NAM GIVEN THE MEAGER
INSTABILITY AND SURFACE LOW WELL TO OUR SOUTH AS DYNAMICS...WHILE
PRESENT...ARE NOT OVERLY IMPRESSIVE.
WITH PRECIPITATION NOT EXPECTED TO MAKE IT INTO THE REGION UNTIL THE
LATE MORNING AND EARLY AFTERNOON...HIGH TEMPERATURES SHOULD BE ABLE
TO GET INTO THE MIDDLE TO UPPER 70S GIVEN THE RELATIVELY WARM START
AFFORDED BY THE OVERNIGHT CLOUD COVER. RAIN AND ABUNDANT CLOUDS
SHOULD KEEP OVERNIGHT LOWS IN THE LOWER TO MIDDLE 60S.
LONG TERM...TUESDAY THROUGH SUNDAY
UPPER TROUGH AXIS AND BACK EDGE OF DEFORMATION WILL SLOWLY PUSH OUT
OF SOUTHEAST MICHIGAN DURING THE MORNING HOURS ON TUESDAY. POTENTIAL
FOR SHOWERS AND THUNDERSTORMS WILL THEREFORE BE HIGHEST IN THE
MORNING...WITH LOWER CHANCES BY AFTERNOON AND EARLY EVENING. CLOUD
COVER SHOULD HELP KEEP MAX TEMPS CONFINED TO THE 70S.
UPPER SHORTWAVE RIDGE WILL THEN CROSS OVER THE AREA TUESDAY NIGHT
AND WEDNESDAY...ALLOWING SURFACE HIGH PRESSURE CENTERED OVER THE
TENNESSEE VALLEY TO EXPAND NORTHWARD INTO THE AREA. DRY WEATHER IS
EXPECTED UNDER THE HIGH...WITH GOOD INSOLATION HELPING TO BOOST
TEMPS BACK INTO THE UPPER 70S TO LOW 80S.
UPPER WAVE ON WATER VAPOR NOW SOUTH OF ALASKA WILL TRACK EAST AND
ACROSS ONTARIO BY EARLY THURSDAY. THE WAVE WILL THEN LIFT NORTH
TOWARDS HUDSON BAY ON FRIDAY AND SATURDAY...FORMING A LARGE UPPER
LOW OVER EASTERN CANADA. THIS WILL KEEP MICHIGAN CONFINED WITHIN A
BROAD UPPER TROUGH THROUGH EARLY NEXT WEEK...WITH MAX TEMPS EXPECTED
TO RUN WELL BELOW NORMAL ON FRIDAY AND THROUGH THE WEEKEND.
A WARM FRONT WILL FIRST LIFT ACROSS LOWER MICHIGAN WEDNESDAY NIGHT
AS SURFACE LOW PRESSURE QUICKLY SPINS UP LEE OF THE ROCKIES AND
BEGINS TO TRACK EAST. NAM SHOWS ISENTROPIC ASCENT WILL INCREASE
OVERNIGHT...BUT SOUNDINGS INDICATE MOISTURE WILL BE LACKING IN THE
LOWER LEVELS TO WORK WITH THE FORCING. WITH LOW-LEVEL DRY AIR
NEEDING TO FIRST BE OVERCOME...THINK PRECIPITATION FOR THE MOST PART
WILL HOLD OFF UNTIL LATE THURSDAY WHEN LOW-LEVEL JET IS FINALLY ABLE
TO PUMP HIGHER MOISTURE UP INTO THE GREAT LAKES (1.75 INCHES PER
GFS)...AND A STRONG COLD FRONT APPROACHES. GFS/EURO/GEM SHOW
PRECIPITATION WILL MAINLY BE TIED TO THE FRONTAL PASSAGE...BUT
EXPECT A FAIRLY BROAD AREA OF RAIN/TSTORMS TO DEVELOP AS GOOD UPPER
DIVERGENCE BECOMES POSITIONED OVER THE FRONT AND FAIRLY HEALTHY
LOW-LEVEL JET FEEDS MOISTURE UP INTO THE AREA. ALSO CANNOT RULE OUT
THE POSSIBILITY OF AN MCS DEVELOPING OVERHEAD...OR MOVING INTO LOWER
MICHIGAN FROM UPSTREAM. SOUTHEAST MICHIGAN LOOKS TO PICK UP ANOTHER
0.25 TO 0.50 INCHES OF RAINFALL FROM THIS SYSTEM BEFORE IT EXITS TO
OUR EAST ON FRIDAY.
MARINE...
QUIET MARINE CONDITIONS WILL BE MAINTAINED THIS MORNING AS A WEAK
RIDGE OF HIGH PRESSURE TRACKS EAST OF THE CENTRAL GREAT LAKES. IN
ITS WAKE A LOW PRESSURE SYSTEM WILL TRACK ACROSS THE SOUTHERN GREAT
LAKES TONIGHT AND TUESDAY. THIS SYSTEM WILL ONCE AGAIN PROVIDE HIGH
CHANCES FOR RAIN AND THUNDERSTORMS DURING IT`S TRANSIT ACROSS THE
AREA. ANOTHER LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT WILL
THEN AFFECT THE AREA THURSDAY NIGHT AND FRIDAY. DESPITE THE ACTIVE
WEATHER PATTERN...WINDS AND WAVES SHOULD BE BELOW HEADLINE CRITERIA
THROUGH THE WORK WEEK.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....KURIMSKI
SHORT TERM...KURIMSKI
LONG TERM....HLO
MARINE.......KURIMSKI
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
259 AM CDT MON AUG 13 2012
.DISCUSSION...
SHORT TERM CONCERNS DEAL WITH WEAK FRONTAL BOUNDARY ACROSS
NORTHERN MN...MOVING SE ACROSS THE FA DURING THE LATE MORNING/AFTN
TIME FRAME WHICH MAY GENERATE AN ISOLATED SHRA/TSRA IN THE FAR
EASTERN 1/4 OF THE FA. OTHER CONCERNS DEAL WITH TEMPS WED
AFTN...AND ONSET OF PRECIPITATION WED/WED NIGHT.
A BROKEN LINE OF SHRA/TSRA WAS OCCURRING IN NE MN PRIOR TO 3 AM.
THIS BROKEN LINE WAS ASSOCIATED WITH A MID-LEVEL SHRTWV ACROSS
SOUTH CENTRAL CANADA...ENHANCED BY A 25H JET STREAK ACROSS ND.
AMPLE MOISTURE AT MID LEVELS AND WEAK INSTABILITY DURING THE
AFTN...SHOULD BE ENOUGH TO GENERATE SCATTERED SHRA/TSRA FOR MAINLY
WC WI...BUT COVERAGE SHOULD BE LESS THAN 30%.
THE NEXT SYSTEM THAT WILL AFFECT THE UPPER MIDWEST WAS ACROSS THE
GULF OF ALASKA EARLY THIS MORNING...WHICH WILL TRANSLATE E/SE
ACROSS WESTERN CANADA...AND INTO THE NORTHERN ROCKIES BY TUESDAY.
TIMING OF THE FRONTAL PASSAGE WITH THIS SYSTEM HAS BEEN FAIRLY
CONSISTENT FOR WEDNESDAY AFTN/EVENING. THERE STILL REMAINS SOME
UNCERTAINTY WITH THE WAA REGIME DEVELOPING TUESDAY NIGHT/WED
AHEAD OF THE MAIN UPPER SUPPORT. THE LLJ IS NOT CONDUCIVE FOR OUR
REGION TO DEVELOP NOCTURNAL CONVECTION ALONG THE LEADING EDGE OF
THE MUCH WARMER AIR...AND WITH THE MAIN FORCING NORTH OF THE FA.
HOWEVER...THE UNCERTAINTY OF WHERE THIS LLJ DEVELOPS AT LEAST
WARRANTS SLIGHT CHC/S...OR UNTIL WED AFTN/EVENING WHEN THE MAIN
UPPER JET AND THE FRONTAL BOUNDARY MOVES ACROSS THE AREA. HIGHS ON
WED WILL BE DIFFICULT. THERE COULD BE SOME AREAS IN THE SW FA
WHICH READINGS REACH THE 90S...WITH 70S IN THE N FA DUE TO BETTER
CHC/S OF PRECIPITATION AND DENSER CLOUD COVER. WILL LEAN TOWARD
HIGHER TEMPS IN THE SOUTH...BUT THESE COULD BE CONSERVATIVE IF THE
FRONT SLOWS...AND LESS CLOUD COVER EXISTS.
AS WITH PREVIOUS FORECAST...THIS FRONT IS FAIRLY STRONG WHICH WILL
LEAD TO SVR WX CONCERNS WED. WILL HIGHLIGHT MORNING HWO BASED ON
THIS SCENARIO AND SEE WHAT SPC HIGHLIGHTS.
BEHIND THIS SYSTEM...TEMPS FALL TO WELL BELOW MID AUGUST READINGS.
SOME OF THE NORMALIZED ANOMALIES /GEFS/ OF 92/85/70H TEMPS ARE
RUNNING 1-2 STANDARD DEVIATIONS BELOW NORMAL ACROSS THE UPPER
MIDWEST THRU MOST OF THE PERIOD PAST WED. IN SOME PARTS OF THE
PLAINS...THESE ANOMALIES ARE 2-3 STANDARD DEVIATIONS BELOW NORMAL
FOR MID AUGUST. BASICALLY...OUR ABNORMAL WARM TEMPS WE HAVE BEEN
EXPERIENCING WILL END. WITH AT LEAST A PERIOD OF BELOW NORMAL
TEMPS THRU NEXT WEEK...AFT THE FRONTAL PASSAGE WED. LITTLE IN THE
WAY OF PRECIPITATION IS EXPECTED AS THE MAIN STORM SYSTEMS MOVE
SOUTH OF THE REGION. ..JLT..
&&
.AVIATION.../06Z TAF ISSUANCE/
LOW CIGS AND PRECIP NOW EXITING SRN MN AND ALL TERMINALS ARE NOW
DONE WITH THAT SYSTEM WITH A WORRISOME CLEARING /FROM THE FOG
POTENTIAL PERSPECTIVE/ QUICKLY WORKING SE OUT OF WRN MN. AT 330Z...A
COLD FRONT STRETCHED FROM NEAR GRAND FORKS UP TOWARD LAKE OF THE
WOODS AND WAS MOVING SOUTH AT ONLY ABOUT 10-15 KTS. MID LEVEL
CLOUDS ASSOCIATED WITH THE FRONT WILL CERTAINLY COMPLICATE THE FOG
SITUATION THIS EVENING. AS FOR THE FOG...MOST SITES IN WRN MN HAVE
A DEWP DEPRESSION LESS THAN 5 DEGS...AND WITH RWF PICKING UP OVER
AN INCH OF RAIN OVER THE LAST 24 HOURS...FOG IS CERTAINLY A CONCERN
NOW THAT SKIES HAVE CLEARED OUT. HRRR HAS BEEN PAINTING DENSE FOG
ACROSS SW MN AS WELL FOR SEVERAL RUNS NOW...SO DID INCREASE FG
MENTION AT RWF...COULD CERTAINLY HAVE A FEW HOURS OF DENSE FOG
THERE INTO THE MORNING. ACROSS CENTRAL MN...CLOUDS COMING DOWN
WITH THE FRONT WILL COMPLICATE THE FOG SITUATION...BUT IF STC CAN
SPEND A COUPLE OF HOURS CLOUD FREE...THEY COULD EASILY GO DOWN TO
1/2SM OR LESS BEFORE FRONTAL CLOUDS SHOW UP. AS FOR
WINDS...FOLLOWED MORE OF A MET/HRRR IDEA FOR DIRECTIONS WITH THE
SLOWER FROPA GIVEN SPEED WITH WHICH FRONT IS CURRENTLY MOVING. FOR
MONDAY...CU RULE QUITE NEGATIVE BY LATE MORNING ON THE NAM...AND
EXPECT CU TO COME IN RATHER QUICKLY IN THE MORNING AND FADE DURING
THE AFTERNOON AS PROGRESSIVELY DRIER AIR WORKS IN.
KMSP...SLOWED THE ARRIVAL OF NW WINDS A BIT FROM THE GOING TAF AND
IT MAY NOT BE UNTIL CLOSER TO 15Z THAT THE FIELD TURNS OVER TO A
300 DIRECTION. WILL LIKELY CLEAR MID CLOUDS OUT FOR A BIT THIS
EVENING BEFORE FRONTAL CLOUD BAND MOVES IN...WHICH COULD ALLOW FOR
SOME VALLEY FOR THAT COULD IMPACT PARTS OF THE FIELD CLOSEST TO
THE MN RIVER VALLEY. FOR WINDS...NAM/RUC SHOWING SOME 20 KT WINDS
WITHIN 3K FT OF THE SFC IN THE MORNING...SO MAY SEE A FEW GUSTS UP
OVER 15 KTS THROUGH 20Z...BEFORE HIGH PRESSURE MOVING IN FROM THE
DAKOTAS BEGINS TO CUT BACK ON WIND SPEEDS.
OUTLOOK...
.TUESDAY...VFR. TSRA POSSIBLE LATE TUE NIGHT. VARIABLE WINDS 5 KTS.
.WEDNESDAY...CHANCE TSRA DURING THE DAY...TSRA LIKELY AT NIGHT. S
WINDS 10-20 KTS.
.THURSDAY...SHRA AND ISOLD TSRA ENDING EARLY. NW WINDS 10-20 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JLT/MPG
AREA FORECAST DISCUSSION
NWS GLASGOW MT
847 AM MDT MON AUG 13 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH WEDNESDAY...
MORNING UPDATE...
THUNDERSTORMS DEVELOPED EARLIER THIS MORNING ALONG A NOW NON-EXISTENT
THETA-E RIDGE. A THIN SLIVER OF CAPE APPEARS ON THE MORNING
SOUNDING WHICH THE STORMS ARE CONTINUING TO CONSUME FROM ABOUT 700
MB UP. HOWEVER THESE STORMS WILL NEED TO MOVE OUT OF THEIR
LOCATION TO MAINTAIN AND ARE GRADUALLY PUSHING SOUTH AND EAST.
BEST GUESS FOR THE BLAINE COUNTY STORMS IS THROUGH NORTHERN
PHILLIPS AND INTO VALLEY COUNTY THROUGH THE MORNING HOURS. HOWEVER
THEY ARE NOT EXPECTED TO SURVIVE LONG TODAY AND SHOULD BEGIN TO
DISSIPATE INTO REGULAR RAIN SHOWERS BY THE AFTERNOON HOURS. POP
AND SKY GRIDS HAVE BEEN MODIFIED TO ACCOUNT FOR THIS ALONG WITH A
SLIGHT TWEAK TO DAYTIME HIGHS FOR A MINIMAL RAIN COOLED SHADOW.
GAH
PREVIOUS SHORT TERM DISCUSSION...
WEAK DISTURBANCE CROSSING THE NORTHERN ROCKIES THIS MORNING WHICH
HAD RESULTED IN A MCS COMPLEX OVER SOUTHERN ALBERTA THIS MORNING.
THIS MCS IS CURRENTLY HEADING IN THE DIRECTION OF NORTHEAST
MONTANA. SHORT TERM MODELS SUCH AD THE 4 KM WRF AND HRRR HAVE BEEN
SHOWING THIS FEATURE MOST OF THE NIGHT AND THE 00Z NAM AND GFS
HAVE SORT OF CAUGHT ONTO THIS SOLUTIONS. DECIDED TO PUT SLIGHT
CHANCE POPS IN THE FORECAST FOR THIS MORNING AND KEPT IT IN THE
FORECAST THROUGH THIS AFTERNOON. COULD HAVE GONE HIGHER ON THE
POPS BUT SOMETIMES THESE THINGS TEND TO DIE AS THE SUN RISES. DAY
SHIFT MIGHT NEED TO INCREASE POPS LATER THIS MORNING IF THIS THING
IS STILL CHUGGING AWAY IN OUR DIRECTION.
MONDAY AFTERNOON CONTINUED WITH THE SLIGHT CHANCE POPS ACROSS OUR
EAST AS WE ARE LIKE TO SEE A WARM SURGE OF AIR MOVE ACROSS THE
AREA TODAY. A WEAK WARM FRONT IF YOU WILL THAT WILL STALL ACROSS
OUR EASTERN AND NORTHEAST ZONES AND PROVIDE SOME SURFACE
LIFT AS AN UPPER LEVEL DISTURBANCE CROSSES FOR THE NORTHWEST.
DECIDED TO CONTINUE WITH THE SLIGHT CHANCE POPS MONDAY EVENING AND
MONDAY NIGHT ACROSS THE EAST. THE WIND ACROSS THE REGION WILL BE
IN THE 15 TO 20 MPH RANGE WITH OCCASIONAL HIGHER GUSTS. DECIDED TO
HOLD OFF ON A LAKE WIND ADVISORY AND LET THE DAY SHIFT TAKE A
LOOK AT CONDITIONS LATER THIS MORNING. THE CLOUD COVER MIGHT KEEP
THE MIXING DOWN.
TUESDAY THROUGH WEDNESDAY...A WIDE RANGE OF PROBLEMS EXIST IN THIS
TIME FRAME. FIRST OFF WE HAVE A SHORTWAVE OVER NORTHERN BC THAT
WILL EXIT THE FRONT RANGE AND THEN TAP INTO THE ARCTIC AIR MASS
BUILDING OVER NUNAVUT... CREATING AN EXPRESS LANE DOWN THE
CANADIAN PRAIRIES FOR ONE WHOPPER OF A COLD FRONT. THE NEXT
PROBLEM ON TUESDAY WILL COME IN THE AFTERNOON AS COMPRESSIONAL
WARMING OUT AHEAD OF THE COLD FRONT WILL SHOW UP TUESDAY MORNING
AND LAST INTO THE AFTERNOON HOURS. THIS WILL CAUSE THE RELATIVE
HUMIDITIES TO DROP SOUTH OF THE MISSOURI RIVER INTO THE LOWER TEEN.
THE WINDS WILL INCREASE AHEAD OF THIS COLD FRONT IN THE SAME AREA
OUT OF THE WEST TUESDAY AFTERNOON CREATING CRITICAL FIRE WEATHER
CONDITIONS.
THE FRONT WILL BLOW THROUGH THE REGION EARLY WEDNESDAY MORNING AND
OUR TEMPER TUES WILL BEGIN TO DROP. THE WINDS WILL INCREASE DUE TO
THE CAA BEHIND THE FRONT SO EXPECT GUSTY NORTHERLY WINDS TUESDAY
NIGHT THROUGH WEDNESDAY AFTERNOON. A LAKE WIND ADVISORY WILL
LIKELY BE NEEDED FOR THIS TIME FRAME. ALSO ALL PRECIPITATION LOOKS
TO BE POST FRONTAL SO HAVE INCREASED POPS BEHIND THE FRONT THROUGH
WEDNESDAY AFTERNOON. MOSTLY SHOWERS BUT COULD HAVE SOME EMBEDDED
THUNDER WITH THESE SHOWERS. ALSO LOWERED THE HIGHS ON WEDNESDAY AS
I EXPECT SOME AREAS TO STAY IN THE MID 60S ALONG THE INTERNATIONAL
BORDER. VERY FALL LIKE FOR EARLY AUGUST. RSMITH
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...
THE EXTENDED FORECAST BEGINS WITH THE STRONG FALL LIKE COLD FRONT
THROUGH THE AREA AND HIGH PRESSURE MOVING IN FROM ALBERTA. THIS
WILL BRING STRONG NORTHWEST FLOW TO THE REGION. THE RESULT WILL BE
DRY AND COOL WEATHER WITH BELOW NORMAL TEMPERATURES FOR THURSDAY
AND FRIDAY.
THEN FOR SATURDAY THROUGH MONDAY A WEST COAST RIDGE BUILDS IN
BRINGING BACK THE ABOVE NORMAL TEMPERATURES AND CONTINUED DRY
WEATHER.
DAY 8 NEXT TUESDAY THE EC AND GFS DO HAVE DIFFERENT IDEAS
THEREFORE WILL OPT FOR DAY 7 PERSISTENCE FOR NOW. PROTON
&&
.AVIATION...
VFR. TWO MCS/S OVER SOUTHERN ALBERTA ARE ON TRACK FOR MOVING INTO
THE AREA EARLY THIS MORNING. BASED ON THEIR CURRENT MOVEMENT THEY
WOULD ARRIVE IN NORTHERN PHILLIPS COUNTY BY 13-14Z... THEN KGGW BY
16-17Z. MODELS DO HAVE THEM MAKING IT TO THE AREA THEREFORE HAVE
FAIR CONFIDENCE THAT TSRA WILL AFFECT THE KGGW LOCATION LATER THIS
MORNING. OTHERWISE ISOLATED TSRA COULD BRING FLIGHT CATEGORIES
DOWN TO MVFR BRIEFLY IF THEY PASS OVERHEAD. PROTON
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING
FOR MTZ122-135>137.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS GLASGOW MT
418 AM MDT MON AUG 13 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH WEDNESDAY...
WEAK DISTURBANCE CROSSING THE NORTHERN ROCKIES THIS MORNING WHICH
HAD RESULTED IN A MCS COMPLEX OVER SOUTHERN ALBERTA THIS MORNING.
THIS MCS IS CURRENTLY HEADING IN THE DIRECTION OF NORTHEAST
MONTANA. SHORT TERM MODELS SUCH AD THE 4 KM WRF AND HRRR HAVE BEEN
SHOWING THIS FEATURE MOST OF THE NIGHT AND THE 00Z NAM AND GFS
HAVE SORT OF CAUGHT ONTO THIS SOLUTIONS. DECIDED TO PUT SLIGHT
CHANCE POPS IN THE FORECAST FOR THIS MORNING AND KEPT IT IN THE
FORECAST THROUGH THIS AFTERNOON. COULD HAVE GONE HIGHER ON THE
POPS BUT SOMETIMES THESE THINGS TEND TO DIE AS THE SUN RISES. DAY
SHIFT MIGHT NEED TO INCREASE POPS LATER THIS MORNING IF THIS THING
IS STILL CHUGGING AWAY IN OUR DIRECTION.
MONDAY AFTERNOON CONTINUED WITH THE SLIGHT CHANCE POPS ACROSS OUR
EAST AS WE ARE LIKE TO SEE A WARM SURGE OF AIR MOVE ACROSS THE
AREA TODAY. A WEAK WARM FRONT IF YOU WILL THAT WILL STALL ACROSS
OUR EASTERN AND NORTHEAST ZONES AND PROVIDE SOME SURFACE
LIFT AS AN UPPER LEVEL DISTURBANCE CROSSES FOR THE NORTHWEST.
DECIDED TO CONTINUE WITH THE SLIGHT CHANCE POPS MONDAY EVENING AND
MONDAY NIGHT ACROSS THE EAST. THE WIND ACROSS THE REGION WILL BE
IN THE 15 TO 20 MPH RANGE WITH OCCASIONAL HIGHER GUSTS. DECIDED TO
HOLD OFF ON A LAKE WIND ADVISORY AND LET THE DAY SHIFT TAKE A
LOOK AT CONDITIONS LATER THIS MORNING. THE CLOUD COVER MIGHT KEEP
THE MIXING DOWN.
TUESDAY THROUGH WEDNESDAY...A WIDE RANGE OF PROBLEMS EXIST IN THIS
TIME FRAME. FIRST OFF WE HAVE A SHORTWAVE OVER NORTHERN BC THAT
WILL EXIT THE FRONT RANGE AND THEN TAP INTO THE ARCTIC AIR MASS
BUILDING OVER NUNAVUT... CREATING AN EXPRESS LANE DOWN THE
CANADIAN PRAIRIES FOR ONE WHOPPER OF A COLD FRONT. THE NEXT
PROBLEM ON TUESDAY WILL COME IN THE AFTERNOON AS COMPRESSIONAL
WARMING OUT AHEAD OF THE COLD FRONT WILL SHOW UP TUESDAY MORNING
AND LAST INTO THE AFTERNOON HOURS. THIS WILL CAUSE THE RELATIVE
HUMIDITIES TO DROP SOUTH OF THE MISSOURI RIVER INTO THE LOWER TEEN.
THE WINDS WILL INCREASE AHEAD OF THIS COLD FRONT IN THE SAME AREA
OUT OF THE WEST TUESDAY AFTERNOON CREATING CRITICAL FIRE WEATHER
CONDITIONS.
THE FRONT WILL BLOW THROUGH THE REGION EARLY WEDNESDAY MORNING AND
OUR TEMPER TUES WILL BEGIN TO DROP. THE WINDS WILL INCREASE DUE TO
THE CAA BEHIND THE FRONT SO EXPECT GUSTY NORTHERLY WINDS TUESDAY
NIGHT THROUGH WEDNESDAY AFTERNOON. A LAKE WIND ADVISORY WILL
LIKELY BE NEEDED FOR THIS TIME FRAME. ALSO ALL PRECIPITATION LOOKS
TO BE POST FRONTAL SO HAVE INCREASED POPS BEHIND THE FRONT THROUGH
WEDNESDAY AFTERNOON. MOSTLY SHOWERS BUT COULD HAVE SOME EMBEDDED
THUNDER WITH THESE SHOWERS. ALSO LOWERED THE HIGHS ON WEDNESDAY AS
I EXPECT SOME AREAS TO STAY IN THE MID 60S ALONG THE INTERNATIONAL
BORDER. VERY FALL LIKE FOR EARLY AUGUST. RSMITH
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...
THE EXTENDED FORECAST BEGINS WITH THE STRONG FALL LIKE COLD FRONT
THROUGH THE AREA AND HIGH PRESSURE MOVING IN FROM ALBERTA. THIS
WILL BRING STRONG NORTHWEST FLOW TO THE REGION. THE RESULT WILL BE
DRY AND COOL WEATHER WITH BELOW NORMAL TEMPERATURES FOR THURSDAY
AND FRIDAY.
THEN FOR SATURDAY THROUGH MONDAY A WEST COAST RIDGE BUILDS IN
BRINGING BACK THE ABOVE NORMAL TEMPERATURES AND CONTINUED DRY
WEATHER.
DAY 8 NEXT TUESDAY THE EC AND GFS DO HAVE DIFFERENT IDEAS
THEREFORE WILL OPT FOR DAY 7 PERSISTENCE FOR NOW. PROTON
&&
.AVIATION...
VFR. TWO MCS/S OVER SOUTHERN ALBERTA ARE ON TRACK FOR MOVING INTO
THE AREA EARLY THIS MORNING. BASED ON THEIR CURRENT MOVEMENT THEY
WOULD ARRIVE IN NORTHERN PHILLIPS COUNTY BY 13-14Z... THEN KGGW BY
16-17Z. MODELS DO HAVE THEM MAKING IT TO THE AREA THEREFORE HAVE
FAIR CONFIDENCE THAT TSRA WILL AFFECT THE KGGW LOCATION LATER THIS
MORNING. OTHERWISE ISOLATED TSRA COULD BRING FLIGHT CATEGORIES
DOWN TO MVFR BRIEFLY IF THEY PASS OVERHEAD. PROTON
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING
FOR MTZ122-135>137.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
711 PM CDT TUE AUG 14 2012
.AVIATION...
00Z TAFS FOR KOMA...KLNK...AND KOFK.
VFR CONDITIONS EXPECTED THROUGH THE PERIOD WITH SCT-BKN
MID CLOUDS AT TIMES. SOUTH WINDS INCREASING AFTER 14Z
WITH GUSTS APPROACHING 30 KTS.
&&
.PREV DISCUSSION... /ISSUED 237 PM CDT TUE AUG 14 2012/
DISCUSSION...
88D MOSAIC LOOP THIS AFTERNOON SHOWING SMALL AREA OF ELEVATED
CONVECTION SLOWLY MOVING ACROSS THE NRN CWA. A FEW STATIONS HAVE
HAD HOURLY PCPN AROUND A TENTH OR SO. EXPECT THOUGH ACTIVITY WILL
WEAKEN AS IT PROGRESSES EASTWARD INTO AREA OF HIGHER CINH.
FOR TONIGHT...NAM/GFS/ECM ALL PLACING SMALL AREA OF QPF IN THE
VICINITY OF THE NRN CWA ASSOCIATED WITH WAA FORCING LIFTING NORTH
INTO THE DAKOTAS/UPPER MIDWEST. HOWEVER...12Z RUN OF 4KM WRF IS DRY
AS WELL AS RAP GUIDANCE.
OTHERWISE...LARGE SCALE FLOW CONSISTING OF A DEEP BROAD TROF
ESTABLISHED OVER THE EASTERN CONUS WITH UPSTREAM NORTHWEST FLOW
EXTENDING ALL THE WAY TO THE BRITISH COLUMBIA COASTLINE. PATTERN
THOUGH WILL GRADUALLY ALTER LATER THIS WEEK WHEN DEEP LOW PRESSURE
OVER THE ALASKAN GULF SHIFT EAST AND PUSHES AN AMPLIFYING RIDGE
TOWARD THE ROCKIES.
IN THE MEANTIME...SHORT TERM FEATURE OF INTEREST CONTINUES TO BE
ANTICIPATED COLD FRONT PUSHING DEEP INTO PLAINS ON WEDNESDAY. LEADING
EDGE OF COLD FRONT SHOULD BE PUSHING INTO THE NRN CWA BY AFTERNOON
AND QUICKLY SLIDE SEWD THROUGH THURSDAY MORNING. SVR STORM THREAT AS
THE BNDRY PUSHES THRU QUITE POSSIBLE IF NOT LIKELY WHEN CAP WEAKENS
BY LATE AFTN. INSTABILITY AND SHEAR WILL BE ABUNDANT...MUCAPE 3500
J/KG...LI -7...EFFECTIVE SHEAR 30-40KT...TO PRODUCE STORMS
CONTAINING LARGE HAIL AND DAMAGING WINDS. EXPECT LINGERING PCPN
ACTIVITY THURSDAY MORNING...FOR THE MOST PART SOUTH OF I-80...SHOULD
COME TO A CLOSE BEFORE AFTN. THIS FRONT WILL BRING A NOTICEABLE
CHANCE IN TEMPS...COMPARED TO AS OF LATE...WITH HIGHS THURSDAY THRU
SUNDAY IN THE MID/UPPER 70S.
FOR MONDAY AND TUESDAY...EXPECT A SLIGHT WARMING TREND OVER THE
CNTRL PLAINS AS AFOREMENTIONED UPPER RIDGE SLIDES CLOSER TO THE
REGION. SHOULD BE ABLE TO REACH LOW/MID 80S FOR AFTN HIGHS.
DEE
AVIATION...
18Z TAFS FOR KOMA...KLNK...AND KOFK.
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ASSOCIATED WITH A
WEAK UPPER LEVEL IMPULSE...ALONG AND AND NORTH A WEAK MID LEVEL
FRONTAL BOUNDARY WILL CONTINUE TO MOVE THROUGH NORTHEAST
NEBRASKA...AFFECTING THE KOFK TAF SITE THROUGH ABOUT 20Z.
OTHERWISE...VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD WITH
SOUTH SOUTHWESTERLY WINDS AROUND 12 KNOTS. COULD BE SOME SPORADIC
GUSTS UP TO ABOUT 18 KNOTS. GUSTS COULD REDEVELOP BY 15/15Z
TOMORROW AS WELL AHEAD OF THE NEXT COLD FRONT.
DEWALD
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
FOBERT
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
939 PM EDT TUE AUG 14 2012
.SYNOPSIS...
WEAK COLD FRONT WILL APPROACH THE REGION TOMORROW AND CROSS THE
AREA LATE WEDNESDAY NIGHT INTO THURSDAY MORNING. ANOTHER FRONT
WILL MOVE INTO THE AREA THIS WEEKEND AND BECOME STATIONARY ACROSS THE
REGION INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 935 PM TUESDAY...SOME CONVECTION OVER THE SOUTHERN COASTAL
PLAINS CURRENTLY AHEAD OF WEAK SURFACE TROUGH OVER THE PIEDMONT.
WHILE THIS ACTIVITY HAS DIMINISHED IN COVERAGE OVER THE PAST
HOUR...LATEST RAP ALONG WITH GFS/NAM12 ALL SHOW SOME ADDITIONAL
SHOWERS/TSTMS DEVELOPING AFTER MIDNIGHT AHEAD OF MID-LEVEL VORTMAX
CROSSING OUR NORTHERN COUNTIES. THE RAP SHOWS THE BEST CHANCE OF
ACTIVITY WILL BE ALONG THE COAST AND HAVE TRENDED POPS TO LOW
CHANCE IN THESE AREAS. NO CHANGES TO FORECAST TEMPERATURES
OVERNIGHT.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
AS OF 345 PM TUESDAY...COLD FRONT WITH ITS ASSOCIATED SHORTWAVE
TROUGH WILL BE OVER CENTRAL NC BY WED MORNING. AS THE FRONT
CONTINUES TO MOVE EASTWARD...THIS WILL PRODUCE SCATTERED SHOWERS
AND THUNDERSTORMS DEVELOPING AHEAD OF THE FRONT. SPC HAS UPGRADED
OUR AREA TO SLIGHT RISK FOR SVR WX. THE LATEST MODELS INDICATE
FOR WED AFTERNOON INTO THE EVENING...CAPE LEVELS OF 3000-4000 AND
LIFTED INDEX TO -7 TO -8. THE MAIN THREAT WILL BE DAMAGING WINDS
AND HAIL.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
AS OF 330 PM TUES...SHORT WAVE TROF AND ASSOCIATED SFC FRONT WILL
BE PASSING OF THE NC COAST WED NIGHT WITH DECREASING PRECIP
CHANCES FROM WEST TO EAST OVERNIGHT. SHORT WAVE RIDGING BUILDS
INTO THE AREA THU RESULTING IN LESS THAN CLIMO PRECIP CHANCES AND
SLIGHTLY ABOVE NORMAL TEMPS.
SHORT WAVE RIDGE MOVES OFFSHORE THU NIGHT WITH ZONAL FLOW DEVELOPING
ON FRIDAY. HAVE LOWERED PRECIP CHANCES AND BACKED OFF ON THE PRECIP
TIMING FRIDAY AFTN GIVEN THE MODEL TRENDS FOR A SLOWER ADVANCE OF
DOWNSTREAM FORCING. SO FRIDAY WILL FEATURE ANOTHER MAINLY DRY DAY
WITH ABOVE NORMAL TEMPS.
FOLLOWING HPC GUIDANCE FOR A SLOWER ECMWF/ECMWF ENS MEAN SOLUTION
WITH REGARD TO FRONTAL SYSTEM TO AFFECT THE FCST AREA THIS WEEKEND
AND BEYOND. WITH BROAD TROF DEVELOPING ALOFT OVER THE EASTERN
STATES...THE SFC FRONT WILL BECOME STALLED OVER THE REGION LEADING
TO AN EXTENDED PERIOD OF UNSETTLED WEATHER. SCATTERED SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE AT JUST ABOUT ANY TIME SAT THROUGH
EARLY NEXT WEEK WITH THE MOST FAVORABLE TIMES DURING PEAK HEATING.
HIGH TEMPS WILL GENERALLY BE IN THE 80S GIVEN EXPECTED CLOUD COVER
AND SCATTERED PCPN.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM /TONIGHT AND TUESDAY/...
AS OF 730 PM TUESDAY...LIGHT WINDS AND HIGH BOUNDARY LAYER
MOISTURE WILL AGAIN FAVOR SOME PATCHY DENSE FOG AT THE TAF SITES
LATE TONIGHT. ANY FOG FORMATION SHOULD MIX OUT BY 13Z WEDNESDAY.
CONDITIONS WILL MOST VFR TOMORROW...WITH SOME SCATTERED CONVECTION
DURING THE AFTERNOON AND EVENING HOURS.
LONG TERM /WEDNESDAY THROUGH SATURDAY/
AS OF 330 PM TUES...LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
PRECIP CHANCES WILL BE DECREASING AS POST FRONTAL DRIER AIR MOVES
INTO THE AREA WED NIGHT. EXPECT MAINLY VFR CONDITIONS WITH HIGH
PRESSURE BUILDING INTO THE AREA THU THROUGH FRIDAY. SCATTERED STORMS
DURING THE WEEKEND WILL LEAD TO INCREASING CLOUDS AND PRECIP
CHANCES...AND CHANCES FOR SUB-VFR INTERVALS THRU SUNDAY.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT THROUGH WEDNESDAY/...
AS OF 945 PM TUESDAY...DECENT GRADIENT CONTINUES ACROSS THE WATERS
BETWEEN TROUGH INLAND AND HIGH OFFSHORE. WINDS ARE GUSTING INTO
THE MID TO UPPER TEENS. SEAS WILL GRADUALLY BUILD TONIGHT FROM 1 TO
3 FEET UP TO 3 TO 4 FOOT BY LATE TONIGHT AND REMAIN IN THAT RANGE
THROUGH WEDNESDAY.
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 330 PM TUES...GOOD BOATING CONDITIONS EXPECTED THURS AND
FRI. WINDS WILL BRIEFLY TURN NORTHERLY BEHIND FRONTAL PASSAGE
EARLY THURS MORNING BUT REMAIN 15 KNOTS OR LESS. WINDS WILL SHIFT
BACK SW THURS NIGHT AND CONTINUE INTO THE EARLY WEEKEND. EXPECT
SEAS 2-3 FT THURS AND FRI. MINOR ADJUSTMENTS TO 00Z WAVEWATCH III
GUIDANCE WITH OVERALL SMALL CHANGES FROM PREVIOUS FORECAST.
MODERATE SW WINDS CONTINUE AHEAD OF FRONT SATURDAY WITH SEAS
BUILDING 2-4 FT. FRONT DROPS INTO THE MARINE AREA SAT NIGHT AND
SUNDAY WITH POST-FRONTAL WINDS TURNING NORTH BUT GENERALLY REMAINING
LESS THAN 15 KT. STILL QUESTIONABLE WHERE FRONT WILL EVENTUALLY
STALL SOMEWHERE OVER SOUTHERN COASTAL WATERS ON SUNDAY.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BM
NEAR TERM...CTC
SHORT TERM...BM
LONG TERM...BTC
AVIATION...CTC/BTC/BM
MARINE...CTC/BTC/BM
AREA FORECAST DISCUSSION
NWS RALEIGH NC
905 PM EDT TUE AUG 14 2012
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST TONIGHT...THEN MOVE
THROUGH THE REGION ON WEDNESDAY. WEAK HIGH PRESSURE WILL BUILD INTO
THE AREA WEDNESDAY NIGHT THROUGH THURSDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY NIGHT/...
AS OF 900 PM TUESDAY...
THROUGH TONIGHT: THE RISK FOR WIDELY SCATTERED STORMS WILL PERSIST
FOR AT LEAST A FEW MORE HOURS. WATER VAPOR IMAGERY REVEALS AN
ELONGATED SHORTWAVE TROUGH OVER ERN NC... ACCOMPANYING A POCKET OF
WEAK UPPER DIVERGENCE. A SECOND WEAKER MID LEVEL WAVE OVER THE NC
FOOTHILLS HAS HELPED FUEL ISOLATED STRONG TO SEVERE STORMS IN THE
HIGHER TERRAIN... AND FOLLOWING THE MEAN CLOUD LAYER FLOW THESE
SHOULD MOVE TO THE NE AND ENE INTO CENTRAL NC. THE STEADY LOW LEVEL
FLOW FROM THE SW AHEAD OF THE INCOMING COLD FRONT HAS HELPED KEEP
DEW POINTS IN THE UPPER 60S TO AROUND 70... YIELDING MODERATELY
UNSTABLE MLCAPE VALUES OF 1500-2500 J/KG... WHILE LOW LEVEL LAPSE
RATES REMAIN STEEP AT 6.5-7.0 C/KM WITH A FAVORABLE EFFECTIVE SHEAR
NEAR 25 KTS. BUT THE GRADUAL LOSS OF HEATING... AS WELL AS THE
EVENTUAL DEPARTURE OF THE WEAK WRN-NC WAVE UP INTO VA AND DAMPENING
IN FAVOR OF THE STRONGER MID MISS VALLEY TROUGH MOVING THROUGH KY
TONIGHT... SHOULD ALLOW FOR A SLOW REDUCTION OF (ALREADY-SMALL)
STORM COVERAGE AND STRENGTH AS WE HEAD THROUGH THE REST OF THE
EVENING AND INTO THE OVERNIGHT HOURS. THIS IS SUPPORTED BY A NUMBER
OF CONVECTION-ALLOWING MODELS INCLUDING THE HRRR AND LOCAL WRF-ARW.
WILL DEPICT SCATTERED STORMS FOR A FEW MORE HOURS FOLLOWED BY A
TREND TOWARD NO POPS SHORTLY AFTER MIDNIGHT. GIVEN THE INSTABILITY
AND SHEAR... ANY STORMS FOR THE NEXT FEW HOURS COULD STILL BE
STRONG. EXPECT PRIMARILY PARTLY CLOUDY SKIES TONIGHT WITH A
COMBINATION OF CONVECTIVE DEBRIS CLOUDS AND CIRRUS OUT AHEAD OF THE
MID MISS VALLEY WAVE. LOWS OF 67-72 STILL APPEAR REASONABLE AND ARE
IN LINE WITH THE PACE OF THE CURRENT TEMPERATURE FALLS. -GIH
WEDNESDAY AND WEDNESDAY NIGHT:
WEAK COLD FRONT IS EXPECTED TO CROSS THE MOUNTAINS WEDNESDAY MORNING
AND EVENTUALLY WORK ITS WAY EASTWARD ACROSS THE AREA THROUGH
DAYLIGHT HOURS. WHILE HEIGHT FALLS ALOFT ARE EXPECTED TO BE RATHER
WEAK(20 METERS)...AMPLIFYING SHORTWAVE ENERGY CURRENTLY OVER THE
CENTRAL PLAINS/MID WILL ROTATE EASTWARD THROUGH THE AREA BETWEEN 12Z
WED TO 00Z THU...LIKELY AUGMENTING VERTICAL ACCELERATIONS
WITHIN THE JET DIVERGENCE REGION OF A 45KT AND 65KT MID AND UPPER
LEVEL JET STREAK TRAVERSING THE AREA. UNLIKE THE PAST FEW
DAYS...CAPE WILL BE AT PREMIUM...AIDED BY THE PRESENCE OF STEEPER
LAPSE RATES ALOFT OF 7.0-7.5 C/KM PER LATEST GFS...WITH MODELS
DEPICTING MODERATE TO STRONG DESTABILIZATION(2000 TO 3000 J/KG OF
MLCAPE) FROM US 1 EAST. DRIER AIR ALOFT ADVECTING WEST TO EAST
THROUGH THE CAROLINAS COULD LIMIT AREAL CONVECTIVE
COVERAGE...ESPECIALLY IN THE WEST...BUT EXPECT STRONG INSTABILITY IN
THE EAST TO HELP OVERCOME DRYING ALOFT TO SUPPORT AT LEAST CHANCE
POPS. THIS MID LEVEL DRY AIR COULD ALSO HOWEVER RESULT IN A GREATER
RISK DAMAGING THUNDERSTORM WIND GUSTS WITH ANY STRONG CELL THAT DOES
DEVELOP. AS SUCH...SPC HAS AREAS FROM US 1 EAST IN THE DAY 2 SLIGHT
RISK.
THE SHORTWAVE VORT MAX IS FORECAST TO CLEAR BY 00Z...WITH TRAILING
SFC FRONT SOON AFTERWARD. THUS EXPECT STORMS TO QUICKLY SHIFT EAST
OF THE AREA SHORTLY AFTER 00Z THU WITH SKIES BECOMING CLEAR AS DRY
SURFACE HIGH PRESSURE BUILDS INTO THE AREA OVERNIGHT.
HIGHS WEDNESDAY MUCH LIKE TODAY...RANGING FROM MID 80S WEST TO UPPER
80S TO AROUND 90 PRETTY MUCH EVERYWHERE ELSE. SLIGHTLY COOLER WITH
DRIER AIR BUILDING IN AND DECENT RADIATIONAL COOLING. MINS IN THE
LOWER TO MID 60S NORTH AND WEST TO UPPER 60S SOUTHEAST. -CBL
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
AS OF 300 PM TUESDAY...
FOR THURSDAY...FAIR WEATHER CONDITIONS ARE EXPECTED AS SURFACE HIGH
PRESSURE AND WEAK UPPER LEVEL RIDGING MOVE IN FROM THE WEST BEHIND
THE DEPARTING TROUGH. TEMPS WILL BE NEAR TO SLIGHTLY BELOW NORMAL...
WITH HIGHS IN THE UPPER 80S TO NEAR 90 DEGREES AND OVERNIGHT LOWS
THE UPPER 60S TO NEAR 70 DEGREES.
ON FRIDAY...AN UPPER LEVEL TROUGH AND ASSOCIATED SURFACE FRONT WILL
BE APPROACHING THE REGION FROM THE WEST. ON FRIDAY MORNING...THE
FRONT IS PROGGED TO STRETCH FROM NY TO LA...WHICH SHOULD RESULT IN
CENTRAL NC REMAINING MOSTLY DRY FOR MUCH OF THE DAYTIME HOURS.
HOWEVER...THERE COULD BE SOME DIURNAL TYPE PRECIP THAT DEVELOPS IN
ASSOCIATION WITH THE PIEDMONT TROUGH...ALTHOUGH COVERAGE WOULD BE
VERY ISOLATED AS MOISTURE WILL STILL BE RATHER LIMITED (PWAT VALUES
LESS THAN 1.5 INCHES). HIGHS SHOULD RISE INTO THE UPPER 80S TO LOWER
90S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 300 PM TUESDAY...
THE AFOREMENTIONED UPPER LEVEL TROUGH AND ASSOCIATED SURFACE FRONT
WILL MOVE CLOSER TO AND EVENTUALLY MOVE THROUGH THE AREA LATE FRIDAY
AND INTO THE WEEKEND. THERE IS STILL SOME UNCERTAINTY ON THE
PROGRESSION OF THIS FRONT THROUGH THE REMAINDER OF THE WEEKEND...BUT
MODELS CONTINUE TO INDICATE IT STALLING SOMEWHERE BETWEEN CENTRAL NC
AND THE COAST. AS A RESULT PRECIP CHANCES WILL INCREASE LATE FRIDAY
AND THEN CONTINUE THROUGH AT LEAST SUNDAY AND MAYBE EVEN INTO EARLY
NEXT WEEK (ESPECIALLY ACROSS THE EASTERN HALF OF THE FORECAST AREA).
WITH MODELS SHOWING MODERATE INSTABILITY AND BULK SHEAR VALUES OF AT
LEAST 30 KNOTS (ESPECIALLY ON SATURDAY)...THE SEVERE THREAT WILL
HAVE TO BE MONITORED CLOSELY. ALSO...WITH PWAT VALUES APPROACHING OR
EVEN EXCEEDING 2 INCHES...HEAVY RAINFALL WILL CERTAINLY BE A THREAT.
PRECIP CHANCES SHOULD BEGIN TO DIMINISH EARLY NEXT WEEK...ALTHOUGH
MINIMAL CHANCES WILL BE CARRIED THROUGH THE END OF THE FORECAST
PERIOD AS THE MID LEVEL TROUGH REMAINS NEAR THE REGION AND
UNCERTAINTY CONTINUES WITH RESPECT TO THE POSITION OF THE SURFACE
FRONT. TEMPS WILL BE BELOW NORMAL THROUGH THE LONG TERM PERIOD
(ESPECIALLY THE LATTER HALF OF THE PERIOD)...WITH HIGH GENERALLY IN
THE LOW TO MID 80S AND LOWS IN THE LOW TO MID 60S.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
AS OF 745 PM TUESDAY...
24-HR TAF PERIOD...
SCATTERED SHOWERS AND STORMS AROUND THE REGION HAVE REMAINED OUTSIDE
OF CENTRAL NC THUS FAR THIS EVENING. RADAR TRENDS SUGGEST A SMALL
CLUSTER OF STORMS NEAR KHKY MAY IMPACT KINT AND/OR KGSO BY
01-02Z...WITH MVFR OR IFR CEILINGS/VSBYS AND WIND GUSTS OF 30-40MPH
POSSIBLE. SHOWERS AND STORMS MAY CONTINUE TO DEVELOP THIS EVENING
AS AN UPPER LEVEL DISTURBANCE SWINGS ACROSS THE AREA FROM THE
WEST...BUT DWINDLING INSTABILITY SHOULD LIMIT THE COVERAGE AND
INTENSITY. OTHERWISE...MVFR PRE-DAWN MVFR VSBYS ARE MOSTLY LIKELY
AT KRWI AND KFAY.
FOR WEDNESDAY...A WEAK COLD FRONT WILL MOVE INTO THE AREA DURING THE
DAY...AND SHOULD BE THE FOCUS FOR STORMS ACROSS MAINLY EASTERN NC
WEDNESDAY AFTERNOON. HAVE KEPT THE MENTION OF VCSH FROM THE
PREVIOUS TAF...AND SUBSEQUENT ISSUANCES MAY HAVE BETTER CONFIDENCE
IN THE POTENTIAL TIMING OF STORMS AT KFAY AND KRWI.
OUTLOOK...
DRY/VFR CONDITIONS THU AND THU NIGHT AS WEAK HIGH PRESSURE BUILDS
INTO THE AREA FROM THE WEST. A PROLONGED PERIOD OF ADVERSE AVIATION
CONDITIONS ARE POSSIBLE BY LATE FRIDAY AND THROUGH THE WEEKEND
AS UNSEASONABLY STRONG UPPER LEVEL TROUGH SETTLES OVER THE EASTERN
US...RESULTING IN WIDESPREAD SHOWERS AND STORMS.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...HARTFIELD/CBL
SHORT TERM...KRR
LONG TERM...KRR
AVIATION...CBL/SMITH
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1255 PM EDT MON AUG 13 2012
.SYNOPSIS...
WEAK HIGH PRESSURE WILL BUILD OVER EASTERN NORTH CAROLINA THROUGH
TUESDAY AS A WEAK FRONT REMAINS STALLED WELL NORTH OF THE AREA. A
COLD FRONT WILL MOVE INTO AREA WEDNESDAY WITH ANOTHER STRONGER
FRONT APPROACHING THE REGION ON FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1250 PM MONDAY...SHOWERS HAVE DEVELOPED IN AXIS OF SLIGHTLY
HIGHER SURFACE THETA-E OVER THE FAR NORTHEASTERN CWA. EXPECT SOME
ADDITIONAL SHOWERS AND PERHAPS A THUNDERSTORM OR TWO TO DEVELOP
SOUTHWEST ALONG THE SEA BREEZE THROUGH EARLY EVENING. HAVE RAISED
POPS SLIGHTLY OVER TYRRELL AND DARE COUNTIES WITH SLIGHT CHC
CONTINUING ELSEWHERE. LATEST RAP MODEL INDICATES ALL PRECIPITATION
SHOULD END BY 8 PM THIS EVENING. NO OTHER MAJOR CHANGES AT THIS
TIME.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
AS OF 330 AM MONDAY...DRY CONDITIONS CONTINUE INTO MONDAY NIGHT.
WILL SEE A FEW CLOUDS SPREADING ACROSS THE AREA...THAT WILL LIMIT
FOG POTENTIAL. ALTHOUGH COULD SEE SOME LIGHT BRIEFLY PATCHY GROUND
FOG MONDAY NIGHT...IT WILL NOT BE NEAR THE POTENTIAL THERE IS THIS
MORNING.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 330 AM MON...BROAD LOW AMPLITUDE UPPER TROUGH WILL DEVELOP
ACROSS THE UPPER MISSISSIPPI VALLEY MON AND PUSH EAST TOWARDS THE
GREAT LAKES AND NORTHEASTERN U.S. TUES INTO WED. SURFACE LOW
DEVELOPMENT WILL OCCUR ACROSS THE OHIO RIVER VALLEY WITH A COLD
FRONT EXTENDING SOUTH TO NEAR THE CENTRAL GULF COAST. AS THE UPPER
TROUGH SHIFTS WEST TUES INTO WED A STRONG SHORTWAVE TROUGH WILL
PUSH EAST FROM THE CENTRAL PLAINS AND WILL AID IN SHOWER AND
THUNDERSTORM DEVELOPMENT ALONG THE SURFACE TROUGH TUES NIGHT INTO
WED. TUES WILL BE DRY WITH MID/UPPER LEVELS MOISTENING AS THE FRONT
APPROACHES LATE. PWATS BUILD BACK OVER 1.50 INCHES TUES NIGHT AS
SOUTHERLY FLOW TAKES OVER. OVERALL ONLY MINOR TWEAKS TO PREVIOUS
POPS/WX FORECAST TO REFLECT CHANGES IN GENERAL MODEL BLEND TUES
THROUGH THURS. HAVE MAINTAINED SLIGHT CHANCE TUES NIGHT INCREASING
TO 35-40 PERCENT CHANCE POPS WED. MODEL BLEND QPF FOR THE FRONTAL
PASSAGE WED RANGES 0.25-0.50 INCHES. LOW LEVEL THICKNESSES WILL
RANGE 1410-1415 METERS TUES THROUGH WED WHICH WILL PRODUCE MAX
TEMPS IN THE UPPER 80S WITH SOME SOUTHERN LOCALES REACHING THE
LOWER 90S.
SURFACE RIDGE WILL BUILD IN FROM THE NW THURS BEHIND THE EXITING
FRONT...WITH QUASI-ZONAL FLOW DEVELOPING ALOFT AND THUS KEPT THURS
DRY. LOW LEVEL THICKNESSES CONTINUE 1410-1415 METERS WITH CLEAR
SKIES EXPECTED THURS...MAX TEMPS WILL BUILD INTO THE UPPER 80S TO
LOWER 90S.
TIMING DIFFERENCES ARE APPARENT IN THE EXTENDED FROM FRI TO SUN...HAVE
HEDGED CLOSER TO THE 12Z/12TH ECMWF FOR THIS MORNINGS PACKAGE. THE
RIDGE WILL SHIFT OFFSHORE FRI MORNING ALLOWING RETURN SURFACE FLOW
TO DEVELOP BY FRI. CONTINUED SLIGHT CHANCE POPS FRI AFTERNOON FOR
DIURNAL CONVECTION. ANOTHER UPPER LEVEL TROUGH WILL DEVELOP ACROSS
THE NORTHERN PLAINS STATES FRI THEN AMPLIFY AS IT HEADS EAST
TOWARDS THE GREAT LAKES INTO SAT. AT THE SURFACE A COLD FRONT WILL
EXTEND FROM THE NORTHEASTERN STATES SOUTHWEST TO TN/MS/AL
AND PUSH EAST TOWARDS EASTERN NC ON SAT...BRINGING ANOTHER CHANCE
FOR SHOWERS AND THUNDERSTORMS. ADJUSTED POPS/WX TO BETTER REFLECT
TRENDS IN THE EXTENDED 12Z/12TH ECMWF...HOWEVER 00Z/13TH ECMWF
TRENDED CLOSER TO 00Z/13TH GFS WHICH HANGS UP THE SURFACE TROUGH
ACROSS THE CAROLINAS SAT THROUGH EARLY NEXT WEEK. IF 00Z SCENARIOS
MATERIALIZE THEN WE COULD SEE ANOTHER PROLONGED PERIOD OF UNSETTLED
WEATHER WITH SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE SAT
THROUGH EARLY NEXT WEEK. LOW LEVEL THICKNESSES CHANGE LITTLE
FRI/SAT THEN FALL TO NEAR 1400 METERS SUN. THESE VALUES WITH
INCREASING CLOUD COVER AND PRECIP SUPPORT TEMPS IN THE MID/UPPER
80S FRI/SAT...THEN LOW TO MID 80S SUN.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
SHORT TERM /THROUGH MONDAY NIGHT/...
AS OF 330 AM MONDAY...A FEW SPOTS SAW SOME PATCHY FOG
DEVELOP...WITH CONDITIONS FLUCTUATING WILDLY BETWEEN
LIFR...IFR...AND MVFR CURRENTLY. FOG SHOULD QUICKLY BURN OFF AFTER
SUNRISE. VFR CONDITIONS WILL PERSIST THROUGH MOST OF MONDAY
NIGHT...AS RIDGING BUILDS OVER THE AREA. THERE IS JUST AN ISOLATED
THREAT OF A THUNDERSTORM ON THE SEA BREEZE OR OLD FRONTAL
BOUNDARY. COULD SEE SOME PATCHY FOG DEVELOP AGAIN MONDAY NIGHT. WILL
ALLOW FOR SOME MVFR VISIBILITIES IN THE TAFS TOWARDS MORNING.
LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 330 AM MON...MAINLY VFR CONDITIONS THROUGH THE LONG TERM.
EXPECT DRY CONDITIONS ON TUES. ISOLATED TO SCATTERED STORMS
POSSIBLE WED ASSOCIATED WITH A FRONTAL PASSAGE. EXPECT DRY
CONDITIONS AGAIN THURS WITH INCREASING CLOUDS AND PRECIP CHANCES
FRI AS ANOTHER FRONTAL SYSTEM APPROACHES FROM THE WEST. CANNOT
RULE OUT BRIEF/SHALLOW FOG LATE NIGHT/EARLY MORNING AS WINDS
DECOUPLE TO CALM JUST PRIOR TO SUNRISE.
&&
.MARINE...
SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
AS OF 1255 PM MONDAY...OPTIMAL MARINE CONDITIONS CONTINUE WITH
LIGHT S/SW WINDS...EXCEPT A SLIGHTLY BACKED SE FLOW OVER THE FAR
NORTHERN WATERS NEAR A WEAK BOUNDARY. SEAS REMAIN 2 TO 3 FEET. NO
SIGNIFICANT CHANGES NEEDED TO CURRENT FORECAST.
LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 AM MON...LIGHT FLOW TUES MORNING WILL BECOME SSW AROUND
10-15 KNOTS BY LATE TUES AFTERNOON/NIGHT AS SURFACE GRADIENT
TIGHTENS SLIGHTLY AHEAD OF APPROACHING FRONT. MAY SEE GUSTS
NEARING 20 KT TUES NIGHT BUT EXPECT WINDS TO REMAIN BELOW SCA
LEVELS. SEAS WILL BUILD 2-4 FT WED AS THE FRONT CROSSES THE
WATERS. WINDS WILL BRIEFLY TURN NORTHERLY BEHIND FRONTAL PASSAGE
EARLY THURS MORNING BUT REMAIN 10 KNOTS OR LESS. WINDS WILL SHIFT
BACK SW THURS NIGHT THROUGH THE WEEKEND AND INCREASE 10-15 KNOTS
WITH SEAS 2-4 FT. MINOR ADJUSTMENTS TO 00Z WAVEWATCH III GUIDANCE
WITH OVERALL SMALL CHANGES FROM PREVIOUS FORECAST. SPECTRAL WAVE
GUIDANCE CONTINUES TO INDICATE SE SWELL OF 2 FT AT 9 SECONDS
PERSISTING WED INTO LATE WEEK.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...RSB
NEAR TERM...CTC
SHORT TERM...RSB
LONG TERM...DAG
AVIATION...RSB/DAG
MARINE...RSB/CTC/DAG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
946 PM CDT TUE AUG 14 2012
.DISCUSSION...
HAVE DELAYED ENTRY OF SCT POPS INTO THE DVL BASIN UNTIL AFT 09Z...
ELSE NO SIG CHANGES TO THE FORECAST PACKAGE THIS EVENING. WARM
FRONTAL BAND OF HIGH CIRRUS NOW STRETCHES ACROSS THE AREA ...BUT MID
CLOUD IS STILL ENTERING SWRN MAN AS SFC LOW PRESSURE CENTER STARTS
TO DIG INTO SERN SASK. 00Z NAM AND RAP GUIDANCE IS CONSISTENT WITH
00Z/03Z SFC ANAL IN SHOWING A SLIGHT DELAY IN ARRIVAL OF LOW LEVEL
MOISTURE INTO THE EASTERN DKTAS... MORE COINCIDENT WITH SFC TROFING
AND TRAILING COLD FRONTAL BOUNDARY INTO ERN ND FROM 15-18Z. THEN
EXPECTING ONSET OF SIG PRECIP IN ERN ND FROM LATE FORENOON AND INTO
NWRN MN FRO EARLY AFTERNOON.
&&
.AVIATION...
VFR CONDS WITH SERLY BLAYER FLOW THROUGH EARLY MORNING. INCREASING
LOW TO MID CLOUD AND AREAS OF MVFR CIGS... SCT SHOWERS AND ISOLD
TSTMS INTO ERN ND 15-20Z AND INTO NWRN AND WCNTRL MN 18-01Z.
&&
.PREV DISCUSSION... /ISSUED 246 PM CDT TUE AUG 14 2012/
WED-FRI...GENERALLY SPEAKING THE CONSENSUS OF THE MODELS BRING THE
COLD FRONT INTO THE RED RIVER VALLEY REGION AROUND 18Z WED AND JUST
OUT OF THE FA BY 00Z THU. NOT EXACTLY SURE HOW THINGS WILL PLAY OUT
AS THERE COULD BE A LOT OF CLOUD COVER AROUND IN THE MORNING HELPING
TO RESTRICT WARMING. SPC HAS BEEN SLOWLY BACKING UP THE SLIGHT RISK
AREA FURTHER INTO THE FA BUT IT STILL BASICALLY COVERS JUST THE FAR
EASTERN FA. BEST UPPER JET FOCUS IS INTO NORTHWEST MN BUT THERE WILL
STILL BE GOOD BULK SHEAR ACROSS THE ENTIRE AREA. AMOUNT OF LOW LEVEL
MOISTURE NOT THE BEST WHICH SPC HAS ALSO NOTED. WILL KEEP THE LIKELY
PCPN CHANCES IN THE EASTERN FA FOR WED AFTERNOON AND THEN DROP THEM
BY WED NIGHT INTO THU MORNING. PRETTY DECENT SURGE OF COOLER AIR
BEHIND THE FRONT WHICH WILL RESULT IN BELOW NORMAL TEMPS.
.LONG TERM (FRI NIGHT-TUES)...
LONG RANGE MODELS IN GENERAL AGREEMENT IN HAVING UPPER TROUGH OVER
EASTERN ONTARIO INTO THE WEEKEND...WITH A SECOND WEAK COLD FRONT/500
MB SHORT WAVE DROPPING SOUTH THRU THE AREA LATER FRI NIGHT/SAT
MORNING. ALL BLEND GAVE SOME LOW POPS FOR -SHRA FOR SATURDAY AND
BASED ON DLH/MPX DECIDED TO LEAVE IN LOW POPS FOR BJI-FFM AREAS
SOUTH AND EAST. HIGH PRESSURE FOLLOWS THIS SYSTEM FOR SAT NIGHT-SUN
THEN RETURN FLOW SETS UP MON-TUES AS UPPER TROUGH MOVES EAST AND A
WEAK 500 MB RIDGE BUILDS IN AHEAD OF NEXT SYSTEM DROPPING SOUTH THRU
WRN-CNTRL CANADA. ANY PRECIPITATION FROM THAT SYSTEM WILL HOLD OFF
TIL WED OF NEXT WEEK. TEMPS WILL REMAIN A BIT COOLER THAN AVERAGE
OVER THE WEEKEND AND THEN WARM UP CLOSER TO NORMAL LEVELS EARLY NEXT
WEEK.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
GUST/HOPPES
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
723 AM EDT MON AUG 13 2012
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO MOVE EAST TODAY. THIS WILL ALLOW
LOW PRESSURE TO MOVE INTO THE OHIO VALLEY BY THIS EVENING AND NEAR
LAKE ONTARIO BY LATE TUESDAY. A COLD FRONT WILL SWEEP ACROSS THE REGION
ON TUESDAY. HIGH PRESSURE WILL THEN RETURN TO THE OHIO VALLEY
TUESDAY NIGHT AND WILL PERSIST INTO THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE AT THE SURFACE WILL MOVE EAST TODAY AHEAD OF A
SURFACE LOW AND FRONT. THE WEATHER ISSUES FOR TODAY ARE HOW THICK
WILL THE CLOUDS BE AND WHEN WILL THE SHOWERS MOVE INTO THE AREA
AND WILL THERE BE ANY SPRINKLES BEFORE THE SHOWERS ARRIVE.
THERE WILL BE PLENTY OF CLOUDS TODAY...STARTING OFF AS MID AND
HIGH AND THEN SLOWLY LOWERING. AT THIS TIME LEANING TOWARD MOSTLY
CLOUDY BUT THERE WILL BE SOME FILTERED SUNSHINE. SOME SPRINKLES
HAVE OCCURRED OVER CENTRAL AND SOUTHERN OHIO DURING THE EARLY
MORNING HOURS. WITH THE UPDATE ADDED SPRINKLES TO THE FORECAST FOR
MUCH OF THE AREA THIS MORNING.
WATCHING THE SHOWERS OVER INDIANA. THEY SEEM TO BE DECREASING SOME
AS THEY MOVE EAST. WILL HAVE A CHANCE OF SHOWERS BY 11 AM OVER
EXTREME NORTHWEST OHIO AND THEN SPREAD THE CHANCE EAST. STILL SOME
QUESTION HOW FAR EAST THE SHOWERS COULD SPREAD OR DEVELOP. MANY OF
THE MODELS HAVE QPF OVER THE ENTIRE FORECAST AREA BY 8 PM THIS
EVENING. INCREASED POPS OVER PARTS OF NORTHWEST OHIO THIS
AFTERNOON. MOST INDICATIONS ARE THAT IT WILL BE STABLE
ENOUGH...SO NO MENTION OF THUNDER TODAY. THE HRRR MODEL AND SREF
DATA SEEMS TO AGREE WITH THAT.
HIGH TEMPERATURES ARE TOUGH TODAY WITH THE CLOUDINESS. USED A
BLEND OF GUIDANCE BUT WENT TOWARD THE COOLER SIDE BECAUSE I AM
EXPECTING ONLY LIMITED AMOUNTS OF SUNSHINE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
A LOW AND FRONT WILL BE APPROACHING TONIGHT. SLOWLY INCREASING
POPS FROM WEST TO EAST. SOME QUESTION AS TO HOW MUCH THUNDER WILL BE
OCCURRING. WILL NOT DIFFERENTIATE BETWEEN CHANCE THUNDER VERSUS
SHOWERS AND THUNDERSTORMS LIKELY. THE THREAT WILL CONTINUE ON
TUESDAY BUT START DECREASING FROM WEST TO EAST. HIGH PRESSURE WILL
BEGIN BUILDING IN TUESDAY NIGHT AND THEN MOVE EAST ON THURSDAY AS
ANOTHER COLD FRONT APPROACHES FOR THURSDAY NIGHT. AT THIS MOMENT
CONTINUED TO KEEP NORTHWEST OHIO DRY THURSDAY...BUT IT COULD BE
CLOSE. THIS WILL HAVE TO BE MONITORED. THE ECMWF IS A LITTLE
SLOWER THAN THE GFS. USED A BLEND OF GUIDANCE FOR THE
TEMPERATURES.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
A COLD FRONT WILL MOVE RATHER QUICKLY ACROSS THE AREA EARLY FRIDAY
MORNING SETTING UP ANOTHER ROUND OF LAKE EFFECT AND LAKE ENHANCEMENT
PRECIPITATION FOR NORTHEAST OHIO AND NORTHWEST PENNSYLVANIA. MODELS
DIFFER IN THE TIMING OF THE WIND SHIFT AWAY FROM THE LAKE TO END THE
PRECIPITATION. CURRENT THINKING IS THE PRECIPITATION SHOULD FINALLY
END BY SUNDAY MORNING AS HIGH PRESSURE BECOMES THE DOMINANT FEATURE.
IN THE MEAN TIME PRECIPITATION ASSOCIATED WITH THE COLD FRONT WILL
SWEEP EAST AND OUT OF THE REGION ALLOWING FOR FAIR WEATHER TO RETURN
TO MUCH OF THE FORECAST AREA...EXCEPTION BEING NORTHEAST.
SINCE COLD FRONT MOVES THROUGH THE AREA EARLY FRIDAY
MORNING...MINIMAL RECOVERY IN TEMPERATURES WILL OCCUR ON FRIDAY AS
COLD AIR ADVECTION BEGINS TO TAKE PLACE. COOL DOWN LASTS INTO THE
WEEKEND UNTIL ABOUT SATURDAY WHEN THE SURFACE HIGH MOVES EAST OF THE
REGION AND BEGINS A SLOW WARM UP ACROSS THE AREA.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
LATEST EUROPEAN MODEL APPEARS TO BE PICKING UP ON A WEAK
SHORTWAVE TROUGH IN THE UPPER LEVELS MOVING EAST TOWARD THE
REGION. THIS FEATURE FITS WELL WITH THE ACTIVITY MOVING THROUGH
INDIANA AT THIS TIME. THIS FEATURE IS PROGGED TO MARCH EAST ACROSS
OUR AREA THIS MORNING AND BE EAST OF THE AREA AFTER 21Z TIME
FRAME. EXPECTING SOME LOWERING OF THE CEILINGS AND VISIBILITIES
OVERNIGHT. OTHERWISE...WINDS SHOULD BE RELATIVELY LIGHT EXCEPT
SLIGHTLY HIGHER WINDS AROUND 10 KNOTS AT MANSFIELD AND AKRON
CANTON. THIS AREA SHOULD END UP SOUTH OF THE WEAK WARM FRONT BY
THIS EVENING.
.OUTLOOK...NON VFR PROBABLE TUESDAY IN SHOWERS/THUNDERSTORMS.
&&
.MARINE...
LAKE SHOULD BE RELATIVELY QUIET UNTIL ABOUT TUESDAY NIGHT WHEN
SOUTHWEST FLOW AHEAD OF THE COLD FRONT DEVELOPS. THIS SHOULD KICK UP
WAVES TO BETWEEN 2 AND 3 FEET. COLD FRONT MOVES EAST ACROSS THE LAKE
EARLY FRIDAY MORNING AND WITH COLD AIR ADVECTION TAKING
PLACE...EXPECTING WAVES TO BUILD TO AROUND 4 FEET AND WILL LIKELY
NEED TO HOIST A SMALL CRAFT ADVISORY. AS COLD AIR ADVECTION OCCURS
OVER THE LAKE ON FRIDAY INTO SATURDAY...POTENTIAL FOR WATER SPOUTS
WILL EXIST ONCE AGAIN.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...KIELTYKA
SHORT TERM...KIELTYKA
LONG TERM...LOMBARDY
AVIATION...LOMBARDY
MARINE...LOMBARDY
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
649 AM EDT MON AUG 13 2012
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO MOVE EAST TODAY. THIS WILL ALLOW
LOW PRESSURE TO MOVE INTO THE OHIO VALLEY BY THIS EVENING AND NEAR
LAKE ONTARIO BY LATE TUESDAY. A COLD FRONT WILL SWEEP ACROSS THE REGION
ON TUESDAY. HIGH PRESSURE WILL THEN RETURN TO THE OHIO VALLEY
TUESDAY NIGHT AND WILL PERSIST INTO THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE AT THE SURFACE WILL MOVE EAST TODAY AHEAD OF A
SURFACE LOW AND FRONT. THE WEATHER ISSUES FOR TODAY ARE HOW THICK
WILL THE CLOUDS BE AND WHEN WILL THE SHOWERS MOVE INTO THE AREA
AND WILL THERE BE ANY SPRINKLES BEFORE THE SHOWERS ARRIVE.
THERE WILL BE PLENTY OF CLOUDS TODAY...STARTING OFF AS MID AND
HIGH AND THEN SLOWLY LOWERING. AT THIS TIME LEANING TOWARD MOSTLY
CLOUDY BUT THERE WILL BE SOME FILTERED SUNSHINE. SOME SPRINKLES
HAVE OCCURRED OVER CENTRAL AND SOUTHERN OHIO DURING THE EARLY
MORNING HOURS. WITH THE UPDATE ADDED SPRINKLES TO THE FORECAST FOR
MUCH OF THE AREA THIS MORNING.
WATCHING THE SHOWERS OVER INDIANA. THEY SEEM TO BE DECREASING SOME
AS THEY MOVE EAST. WILL HAVE A CHANCE OF SHOWERS BY 11 AM OVER
EXTREME NORTHWEST OHIO AND THEN SPREAD THE CHANCE EAST. STILL SOME
QUESTION HOW FAR EAST THE SHOWERS COULD SPREAD OR DEVELOP. MANY OF
THE MODELS HAVE QPF OVER THE ENTIRE FORECAST AREA BY 8 PM THIS
EVENING. INCREASED POPS OVER PARTS OF NORTHWEST OHIO THIS
AFTERNOON. MOST INDICATIONS ARE THAT IT WILL BE STABLE
ENOUGH...SO NO MENTION OF THUNDER TODAY. THE HRRR MODEL AND SREF
DATA SEEMS TO AGREE WITH THAT.
HIGH TEMPERATURES ARE TOUGH TODAY WITH THE CLOUDINESS. USED A
BLEND OF GUIDANCE BUT WENT TOWARD THE COOLER SIDE BECAUSE I AM
EXPECTING ONLY LIMITED AMOUNTS OF SUNSHINE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
A LOW AND FRONT WILL BE APPROACHING TONIGHT. SLOWLY INCREASING
POPS FROM WEST TO EAST. SOME QUESTION AS TO HOW MUCH THUNDER WILL BE
OCCURRING. WILL NOT DIFFERENTIATE BETWEEN CHANCE THUNDER VERSUS
SHOWERS AND THUNDERSTORMS LIKELY. THE THREAT WILL CONTINUE ON
TUESDAY BUT START DECREASING FROM WEST TO EAST. HIGH PRESSURE WILL
BEGIN BUILDING IN TUESDAY NIGHT AND THEN MOVE EAST ON THURSDAY AS
ANOTHER COLD FRONT APPROACHES FOR THURSDAY NIGHT. AT THIS MOMENT
CONTINUED TO KEEP NORTHWEST OHIO DRY THURSDAY...BUT IT COULD BE
CLOSE. THIS WILL HAVE TO BE MONITORED. THE ECMWF IS A LITTLE
SLOWER THAN THE GFS. USED A BLEND OF GUIDANCE FOR THE
TEMPERATURES.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
A COLD FRONT WILL MOVE RATHER QUICKLY ACROSS THE AREA EARLY FRIDAY
MORNING SETTING UP ANOTHER ROUND OF LAKE EFFECT AND LAKE ENHANCEMENT
PRECIPITATION FOR NORTHEAST OHIO AND NORTHWEST PENNSYLVANIA. MODELS
DIFFER IN THE TIMING OF THE WIND SHIFT AWAY FROM THE LAKE TO END THE
PRECIPITATION. CURRENT THINKING IS THE PRECIPITATION SHOULD FINALLY
END BY SUNDAY MORNING AS HIGH PRESSURE BECOMES THE DOMINANT FEATURE.
IN THE MEAN TIME PRECIPITATION ASSOCIATED WITH THE COLD FRONT WILL
SWEEP EAST AND OUT OF THE REGION ALLOWING FOR FAIR WEATHER TO RETURN
TO MUCH OF THE FORECAST AREA...EXCEPTION BEING NORTHEAST.
SINCE COLD FRONT MOVES THROUGH THE AREA EARLY FRIDAY
MORNING...MINIMAL RECOVERY IN TEMPERATURES WILL OCCUR ON FRIDAY AS
COLD AIR ADVECTION BEGINS TO TAKE PLACE. COOL DOWN LASTS INTO THE
WEEKEND UNTIL ABOUT SATURDAY WHEN THE SURFACE HIGH MOVES EAST OF THE
REGION AND BEGINS A SLOW WARM UP ACROSS THE AREA.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
CLOUDS CONTINUE TO MOVE EAST TOWARD THE REGION AT THIS TIME IN
ADVANCE OF THE NEXT STORM SYSTEM. MODELS HINTING AT THE FIRST
ARRIVAL OF MEASURABLE RAIN TO ARRIVE IN TOLEDO FINDLAY AREA BY
00Z THIS EVENING. PRECIPITATION WILL GRADUALLY SPREAD FROM WEST TO
EAST DURING THE NIGHT. PRECIPITATION SHOULD NOT REACH AKRON
CANTON...YOUNGSTOWN AND ERIE UNTIL AFTER THIS TAF PERIOD. CEILINGS
AND VISIBILITIES ARE EXPECTED TO REMAIN VFR THROUGH THE TAF PERIOD
BUT DROP TO MVFR AFTER 06Z AT CLEVELAND. WINDS SHOULD BE LIGHT
THROUGH TODAY BUT START TO INCREASE AS WARM FRONT LIFTS NORTH
ACROSS THE REGION. EXPECTING THE HIGHER WINDS AROUND 10 KNOTS
SOUTH OF THE FRONTAL BOUNDARY...ESPECIALLY AT AKRON CANTON.
.OUTLOOK...NON VFR PROBABLE TUESDAY IN SHOWERS/THUNDERSTORMS.
&&
.MARINE...
LAKE SHOULD BE RELATIVELY QUIET UNTIL ABOUT TUESDAY NIGHT WHEN
SOUTHWEST FLOW AHEAD OF THE COLD FRONT DEVELOPS. THIS SHOULD KICK UP
WAVES TO BETWEEN 2 AND 3 FEET. COLD FRONT MOVES EAST ACROSS THE LAKE
EARLY FRIDAY MORNING AND WITH COLD AIR ADVECTION TAKING
PLACE...EXPECTING WAVES TO BUILD TO AROUND 4 FEET AND WILL LIKELY
NEED TO HOIST A SMALL CRAFT ADVISORY. AS COLD AIR ADVECTION OCCURS
OVER THE LAKE ON FRIDAY INTO SATURDAY...POTENTIAL FOR WATER SPOUTS
WILL EXIST ONCE AGAIN.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...KIELTYKA
SHORT TERM...KIELTYKA
LONG TERM...LOMBARDY
AVIATION...LOMBARDY
MARINE...LOMBARDY
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
647 AM EDT MON AUG 13 2012
.SYNOPSIS...
LOW PRESSURE AND ITS ASSOCIATED COLD FRONT WILL SLOWLY TRACK EAST
ACROSS THE LOWER GREAT LAKES AND OHIO VALLEY THROUGH TUESDAY. HIGH
PRESSURE WILL THEN BUILD BACK ACROSS THE REGION BY THE MIDDLE OF
THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MODELS ARE IN FAIRLY DECENT AGREEMENT IN TERMS OF SYNOPTIC SCALE
SYSTEMS AND THEIR ASSOCIATED STRENGTH AND TIMING. HOWEVER...THERE
WILL BE SOME POTENTIAL PITFALLS IN THE NEAR TERM FORECAST.
SURFACE ANALYSIS DEPICTED AN AREA OF WEAK LOW PRESSURE OVER NE
MISSOURI THIS MORNING. MOSAIC RADAR TO OUR WEST WAS SHOWING A
SIZABLE AREA OF SHOWERS AND EMBEDDED THUNDERSTORMS EXTENDING FROM
NW INDIANA SW ACRS MUCH OF ILLINOIS THEN INTO MISSOURI. THE SHOWERS
ACROSS THE NORTHERN SECTIONS OF ILLINOIS AND INDIANA APPEAR TO BE
THE RESULT OF MID LVL ISENTROPIC LIFT OCCURRING IN THE 8 TO 12 K FT
RANGE. FARTHER SOUTH...SHOWERS AND EMBEDDED THUNDERSTORMS WERE
BEING AIDED BY A 925-850 MB LOW LEVEL JET. IT APPEARS THAT THE
SHOWERS ACRS NRN ILLINOIS AND NW INDIANA WILL PUSH EAST THIS
MORNING AWAY FROM ITS ISENTROPIC SOURCE REGION TOWARD OUR NW
FORECAST AREA. IT IS STILL UNCLEAR AT THIS POINT HOW LONG THESE
SHOWERS WILL STAY IN TACT AS THEY CONTINUE TO MOVE EAST AWAY FROM
THEIR SOURCE REGION. HAVE WENT AHEAD AND GONE WITH LIKELY POPS ACRS
OUR NW ZONES AS THE LATEST HRRR MODEL INDICATES THAT THE SHOWERS
SHOULD AT LEAST MAKE IT HERE BEFORE THEY WEAKEN FURTHER TOWARD THE
AFTERNOON HOURS. FARTHER SOUTH...IT BECOMES TRICKY CONSIDERING
AFOREMENTIONED LOW LEVEL JET WILL WEAKEN SOME TOWARD MORNING. HAVE
PLACED CHANCES POPS HERE AND WILL MONITOR RADAR TRENDS AND HRRR
TRENDS SHOULD HIGHER POPS BE NEEDED. IT APPEARS THAT ALL PCPN
SHOULD BE IN THE FORM OF SHOWERS THROUGH EARLY AFTN AS HIGHER
INSTABILITY IS EXPECTED TO REMAIN TO OUR WEST.
THEREAFTER...MID LVL S/WV WILL CONTINUE TO DIG SE ACRS THE WESTERN
GREAT LAKES THROUGH THE REMAINDER OF THE DAY AS SFC LOW PRESSURE
MOVES TOWARD THE ENE TO SRN INDIANA BY THIS EVENING. THERE SHOULD
BE A RELATIVE LULL IN THE PCPN ACTIVITY THIS AFTERNOON BEFORE
HIGHER CHANCES OF SHOWERS/STORMS ARRIVE TONIGHT.
TEMPERATURES WILL BE HARD TO PIN DOWN GIVEN THE TIMING OF PCPN
AND THE AMOUNT OF CLOUD COVER THAT WILL OCCUR FROM TIME TO TIME
TODAY. HAVE TAKEN A BLEND OF ALL AVAILABLE OPERATIONAL MODELS
WHICH YIELD HIGHS FROM THE UPPER 70S NORTHWEST TO THE MID 80S
ALONG AND SOUTH OF THE OHIO RIVER.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
MID LVL S/WV WILL CONTINUE EAST ACRS OUR AREA OVERNIGHT AS SFC LOW
PRESSURE AND WEAK COLD FRONT MOVE EAST AS WELL. THERE IS ENOUGH
EVIDENCE BY THE MODELS TO GO AHEAD AND RAMP POPS UP INTO THE
LIKELY CATEGORY FOR ALL LOCATIONS AS THERE SHOULD BE ENOUGH LOW
LEVEL CONVERGENCE PER A LOW LEVEL JET AND UPR LVL SUPPORT.
ON TUESDAY...LOW PRESSURE WILL SLOWLY MOVE OFF TO THE NE. ITS
ASSOCIATED WEAK COLD FRONT WILL MEANDER SLOWLY EAST AS WELL.
LIKELY POPS ARE EXPECTED EARLY ON ACRS OUR ERN ZONES...THEN POPS
WILL SLOWLY DECREASE THROUGH THE DAY AS DRIER AIR SLOWLY
INFILTRATES FROM THE WEST.
WEAKENING FRONTAL BOUNDARY IS EXPECTED TO BE EAST OF THE AREA BY
WEDNESDAY NIGHT AS WEAK SFC HIGH PRESSURE BUILDS IN FROM THE WEST.
SKIES WILL GRADUALLY CLEAR.
HIGH PRESSURE WILL SETTLE ACROSS THE OHIO VALLEY ON WEDNESDAY.
MOSTLY SUNNY SKIES ARE EXPECTED WITH SLIGHTLY BELOW NORMAL
TEMPERATURES FOR MID AUGUST. THE HIGH WILL BEGIN TO MOVE EAST OF
THE AREA WEDNESDAY NIGHT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS THE HIGH CONTINUES OFF TO THE EAST ON THURSDAY...WE WILL GET
INTO A RETURN FLOW... RESULTING IN THE WARMEST DAY OF THE WEEK
WITH HIGHS INTO THE UPPER 80S TO THE LOWER 90S.
THE 00Z ECMWF HAS CONTINUED TO TREND SLOWER WITH THE APPROACH OF THE
NEXT SHORT WAVE FOR LATE IN THE WORK WEEK AND IS NOW ABOUT 18 HOURS
OR SO SLOWER THAN THE 12Z GFS. THE 12Z CMC IS ALSO TRENDING SLOWER
SO HAVE TRIMMED BACK THE ONSET OF PCPN FOR THURSDAY NIGHT...WITH THE
BEST CHANCE ON INTO FRIDAY. IT LOOKS LIKE A PRETTY GOOD CHANCE FOR
PCPN SOMETIME THURSDAY NIGHT INTO FRIDAY...BUT GIVEN THE TIMING
ISSUES AM HESITANT TO GO HIGHER THAN CHANCE AT THIS POINT FOR ANY
GIVEN PERIOD. A MUCH COOLER AIRMASS WILL FILTER DOWN INTO OUR AREA
FOR THE WEEKEND AS A 500 MB LOW SETTLES IN OVER THE WESTERN GREAT
LAKES. 850 MB TEMPERATURES WILL DROP DOWN INTO THE 6 TO 8 DEGREE
RANGE AT TIMES SATURDAY INTO SUNDAY. THIS WOULD KEEP HIGHS BOTH
DAYS GENERALLY IN THE LOWER 70S.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
THROUGH THE FIRST PART OF THE DAY...ISOLATED SHOWERS ARE EXPECTED
TO BE POSSIBLE. WHILE THIS ACTIVITY WOULD BE MOST LIKELY AT THE
CINCINNATI TAF SITES (AS DENOTED WITH A TEMPO GROUP)...THEY WILL
BE POSSIBLE AT ALL THE TAF SITES AS THE MORNING PROGRESSES (AND
EARLY AFTERNOON FOR COLUMBUS). THE AIR MASS IS STILL
SATURATING...SO THESE SHOWERS SHOULD REMAIN VFR...GENERALLY
FALLING OUT OF CLOUD DECKS ABOVE 5000 FEET (SOME OF THEM UP INTO
THE MID LEVELS).
ADDITIONAL SHOWERS AND POSSIBLY SOME THUNDERSTORMS WILL DEVELOP
DURING THE LATE AFTERNOON AND EVENING. CONFIDENCE IN THUNDERSTORM
COVERAGE IS NOT PARTICULARLY HIGH...SO THUNDER HAS BEEN EXCLUDED
FROM THE TAFS AT THIS TIME. INSTABILITY WILL BE GREATEST IN THE
SOUTHWEST PART OF THE ILN CWA...MEANING THAT THE CINCINNATI TAF
SITES WILL HAVE THE GREATEST CHANCE FOR THUNDER. WHETHER OR NOT
THUNDER OCCURS...SOME OF THE HEAVIER SHOWERS WILL BE CAPABLE OF
MVFR OR MAYBE EVEN IFR CONDITIONS.
OVERALL...THE GREATEST CHANCE FOR PRECIPITATION WILL COME DURING
THE OVERNIGHT HOURS AS A SURFACE LOW MOVES THROUGH THE REGION.
MOST OF THIS RAIN (POSSIBLY WITH SOME EMBEDDED THUNDER) WILL ALSO
REMAIN VFR...BUT BY DAYBREAK TUESDAY...SOME OF THE CEILINGS ARE
EXPECTED TO BE DROPPING INTO THE MVFR RANGE.
.OUTLOOK...SHOWERS AND THUNDERSTORMS POSSIBLE TUESDAY...ALONG WITH
MVFR AND POSSIBLY IFR CEILINGS.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...HICKMAN
SHORT TERM...HICKMAN
LONG TERM...HICKMAN/JGL
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
419 AM EDT MON AUG 13 2012
.SYNOPSIS...
LOW PRESSURE AND ITS ASSOCIATED COLD FRONT WILL SLOWLY TRACK EAST
ACROSS THE LOWER GREAT LAKES AND OHIO VALLEY THROUGH TUESDAY. HIGH
PRESSURE WILL THEN BUILD BACK ACROSS THE REGION BY THE MIDDLE OF
THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MODELS ARE IN FAIRLY DECENT AGREEMENT IN TERMS OF SYNOPTIC SCALE
SYSTEMS AND THEIR ASSOCIATED STRENGTH AND TIMING. HOWEVER...THERE
WILL BE SOME POTENTIAL PITFALLS IN THE NEAR TERM FORECAST.
SURFACE ANALYSIS DEPICTED AN AREA OF WEAK LOW PRESSURE OVER NE
MISSOURI THIS MORNING. MOSAIC RADAR TO OUR WEST WAS SHOWING A
SIZABLE AREA OF SHOWERS AND EMBEDDED THUNDERSTORMS EXTENDING FROM
NW INDIANA SW ACRS MUCH OF ILLINOIS THEN INTO MISSOURI. THE SHOWERS
ACROSS THE NORTHERN SECTIONS OF ILLINOIS AND INDIANA APPEAR TO BE
THE RESULT OF MID LVL ISENTROPIC LIFT OCCURRING IN THE 8 TO 12 K FT
RANGE. FARTHER SOUTH...SHOWERS AND EMBEDDED THUNDERSTORMS WERE
BEING AIDED BY A 925-850 MB LOW LEVEL JET. IT APPEARS THAT THE
SHOWERS ACRS NRN ILLINOIS AND NW INDIANA WILL PUSH EAST THIS
MORNING AWAY FROM ITS ISENTROPIC SOURCE REGION TOWARD OUR NW
FORECAST AREA. IT IS STILL UNCLEAR AT THIS POINT HOW LONG THESE
SHOWERS WILL STAY IN TACT AS THEY CONTINUE TO MOVE EAST AWAY FROM
THEIR SOURCE REGION. HAVE WENT AHEAD AND GONE WITH LIKELY POPS ACRS
OUR NW ZONES AS THE LATEST HRRR MODEL INDICATES THAT THE SHOWERS
SHOULD AT LEAST MAKE IT HERE BEFORE THEY WEAKEN FURTHER TOWARD THE
AFTERNOON HOURS. FARTHER SOUTH...IT BECOMES TRICKY CONSIDERING
AFOREMENTIONED LOW LEVEL JET WILL WEAKEN SOME TOWARD MORNING. HAVE
PLACED CHANCES POPS HERE AND WILL MONITOR RADAR TRENDS AND HRRR
TRENDS SHOULD HIGHER POPS BE NEEDED. IT APPEARS THAT ALL PCPN
SHOULD BE IN THE FORM OF SHOWERS THROUGH EARLY AFTN AS HIGHER
INSTABILITY IS EXPECTED TO REMAIN TO OUR WEST.
THEREAFTER...MID LVL S/WV WILL CONTINUE TO DIG SE ACRS THE WESTERN
GREAT LAKES THROUGH THE REMAINDER OF THE DAY AS SFC LOW PRESSURE
MOVES TOWARD THE ENE TO SRN INDIANA BY THIS EVENING. THERE SHOULD
BE A RELATIVE LULL IN THE PCPN ACTIVITY THIS AFTERNOON BEFORE
HIGHER CHANCES OF SHOWERS/STORMS ARRIVE TONIGHT.
TEMPERATURES WILL BE HARD TO PIN DOWN GIVEN THE TIMING OF PCPN
AND THE AMOUNT OF CLOUD COVER THAT WILL OCCUR FROM TIME TO TIME
TODAY. HAVE TAKEN A BLEND OF ALL AVAILABLE OPERATIONAL MODELS
WHICH YIELD HIGHS FROM THE UPPER 70S NORTHWEST TO THE MID 80S
ALONG AND SOUTH OF THE OHIO RIVER.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
MID LVL S/WV WILL CONTINUE EAST ACRS OUR AREA OVERNIGHT AS SFC LOW
PRESSURE AND WEAK COLD FRONT MOVE EAST AS WELL. THERE IS ENOUGH
EVIDENCE BY THE MODELS TO GO AHEAD AND RAMP POPS UP INTO THE
LIKELY CATEGORY FOR ALL LOCATIONS AS THERE SHOULD BE ENOUGH LOW
LEVEL CONVERGENCE PER A LOW LEVEL JET AND UPR LVL SUPPORT.
ON TUESDAY...LOW PRESSURE WILL SLOWLY MOVE OFF TO THE NE. ITS
ASSOCIATED WEAK COLD FRONT WILL MEANDER SLOWLY EAST AS WELL.
LIKELY POPS ARE EXPECTED EARLY ON ACRS OUR ERN ZONES...THEN POPS
WILL SLOWLY DECREASE THROUGH THE DAY AS DRIER AIR SLOWLY
INFILTRATES FROM THE WEST.
WEAKENING FRONTAL BOUNDARY IS EXPECTED TO BE EAST OF THE AREA BY
WEDNESDAY NIGHT AS WEAK SFC HIGH PRESSURE BUILDS IN FROM THE WEST.
SKIES WILL GRADUALLY CLEAR.
HIGH PRESSURE WILL SETTLE ACROSS THE OHIO VALLEY ON WEDNESDAY.
MOSTLY SUNNY SKIES ARE EXPECTED WITH SLIGHTLY BELOW NORMAL
TEMPERATURES FOR MID AUGUST. THE HIGH WILL BEGIN TO MOVE EAST OF
THE AREA WEDNESDAY NIGHT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS THE HIGH CONTINUES OFF TO THE EAST ON THURSDAY...WE WILL GET
INTO A RETURN FLOW... RESULTING IN THE WARMEST DAY OF THE WEEK
WITH HIGHS INTO THE UPPER 80S TO THE LOWER 90S.
THE 00Z ECMWF HAS CONTINUED TO TREND SLOWER WITH THE APPROACH OF THE
NEXT SHORT WAVE FOR LATE IN THE WORK WEEK AND IS NOW ABOUT 18 HOURS
OR SO SLOWER THAN THE 12Z GFS. THE 12Z CMC IS ALSO TRENDING SLOWER
SO HAVE TRIMMED BACK THE ONSET OF PCPN FOR THURSDAY NIGHT...WITH THE
BEST CHANCE ON INTO FRIDAY. IT LOOKS LIKE A PRETTY GOOD CHANCE FOR
PCPN SOMETIME THURSDAY NIGHT INTO FRIDAY...BUT GIVEN THE TIMING
ISSUES AM HESITANT TO GO HIGHER THAN CHANCE AT THIS POINT FOR ANY
GIVEN PERIOD. A MUCH COOLER AIRMASS WILL FILTER DOWN INTO OUR AREA
FOR THE WEEKEND AS A 500 MB LOW SETTLES IN OVER THE WESTERN GREAT
LAKES. 850 MB TEMPERATURES WILL DROP DOWN INTO THE 6 TO 8 DEGREE
RANGE AT TIMES SATURDAY INTO SUNDAY. THIS WOULD KEEP HIGHS BOTH
DAYS GENERALLY IN THE LOWER 70S.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
ALTHOUGH A FEW SPRINKLES OR LIGHT SHOWERS ARE POSSIBLE BETWEEN 06Z
AND 08Z (MAINLY AT THE WESTERN TAF SITES)...THE FIRST 8 HOURS OF
THE FORECAST PERIOD APPEAR TO BE RELATIVELY TRANQUIL. MID LEVEL
MOISTURE WILL CONTINUE TO INCREASE OVERNIGHT AND INTO
MONDAY...AND HIGH-RESOLUTION COMPUTER GUIDANCE IS INDICATING THAT
RAIN SHOWERS WILL BE POSSIBLE BY EARLY AFTERNOON FOR THE WESTERN
TAF SITES (AND SLIGHTLY LATER FOR THE COLUMBUS SITES). THIS
ACTIVITY WILL GENERALLY BE DISORGANIZED AND IN THE VFR
CATEGORY...BUT BY LATE AFTERNOON THE DIURNAL CYCLE MAY LEAD TO
SOME HEAVIER SHOWERS. WITH INSTABILITY APPEARING MARGINAL...HAVE
LIMITED THE MENTION OF VCTS TO JUST THE CINCINNATI TAF SITES.
SOME SHOWERS MAY PERSIST INTO MONDAY NIGHT...AS WINDS SHIFT FROM
THE SOUTH TO WEST LATE IN THE FORECAST PERIOD.
.OUTLOOK...THUNDERSTORMS ARE POSSIBLE TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...HICKMAN
SHORT TERM...HICKMAN
LONG TERM...HICKMAN/JGL
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
136 AM EDT MON AUG 13 2012
.SYNOPSIS...
HIGH PRESSURE WILL BEGIN TO SLIDE EAST OF OUR AREA LATE TONIGHT AS
LOW PRESSURE MOVES EASTWARD ACROSS THE NORTHERN PLAINS. THE LOW
WILL TRACK TOWARD THE LOWER GREAT LAKES ON MONDAY NIGHT BRINGING A
COLD FRONT AND CHANCES FOR SHOWERS AND THUNDERSTORMS TO OUR AREA.
HIGH PRESSURE WILL THEN BUILD BACK ACROSS THE REGION BY THE
MIDDLE OF THE WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
SFC HIGH PRESSURE WILL SLIDE OFF TO THE EAST AS LOW PRESSURE
DEVELOPS INTO THE MID MS VLY IN RESPONSE TO DIGGING UPR SYSTEM
OVERNIGHT. WEAK ISENTROPIC LIFT AHD OF THIS SYSTEM HAS LED TO
VERY LIGHT RAIN SHOWERS/SPRINKLES. RADAR SHOWS THESE LIGHT
SHOWERS/SPRINKLES MOVING ACRS INDIANA AND WEAKENING. EXPECT
THIS TREND TO CONTINUE AS THE SHOWERS MOVE INTO A LESS FAVORABLE
ENVIRONMENT WITH DRIER AIR IN PLACE.
HAVE ALLOWED FOR AN INCREASE IN MID LEVEL CLOUD COVER. THESE
CONDITIONS WILL RESULT IN MOSTLY CLOUDY SKY CONDITIONS. MORE BREAKS
WILL BE PSBL IN THE SW AS INITIAL S/W PASSES BY LATE TONIGHT.
CONTINUING TO FOLLOW LATEST HRRR RUNS...HAVE ALLOWED FOR SPRINKLES
TO WORK ACRS ILN/S FA OVERNIGHT.
HAVE FCST LOWS RANGING FROM THE LOW TO MID 50S FAR EAST TO THE
LOW TO MID 60S WEST.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM TUESDAY/...
THE LOW WILL CROSS ILLINOIS AND INDIANA DURING THE DAY MONDAY.
THIS MEANS OUR AREA WILL BE UNDER SOUTHERLY FLOW WITH PLENTY OF
CLOUD COVER DURING THE DAYTIME. THIS SCENARIO WILL YIELD
TEMPERATURES IN THE LOW TO MIDDLE 80S...SIMILAR TO WHAT IS BEING
EXPERIENCED UPSTREAM OVER EASTERN ILLINOIS TODAY.
MODELS DIFFER SOMEWHAT ON THE TRACK OF THE SURFACE LOW MONDAY
NIGHT. THE NAM/CMC REGIONAL/ECMWF TRACK THE LOW ACROSS OUR FORECAST
AREA TUESDAY MORNING....WHILE THE SREF AND GFS PIVOT THE LOW
ACROSS LAKE HURON. THE LATTER SOLUTION IS FASTER AND BASED ON
SATELLITE TRENDS THIS APPEARS TO BE THE MOST LIKELY SCENARIO. THIS
WOULD DRAG A COLD FRONT ACROSS OUR AREA TUESDAY MORNING. AHEAD OF
THIS FRONT...DYNAMIC FORCING WILL SUPPORT CONVECTIVE DEVELOPMENT
ACROSS INDIANA LATE MONDAY AFTERNOON WITH THIS CONVECTION SHIFTING
EAST ACROSS OUR AREA OVERNIGHT MONDAY NIGHT. THIS MEANS THE
CONVECTION WILL BE IN A WEAKENING MODE AS IT PUSHES ACROSS OUR
AREA. HOWEVER...WITH SUFFICIENT PRE-FRONTAL FORCING
OCCURRING...SHOWERS AND THUNDERSTORMS WILL LIKELY HOLD TOGETHER AS
THEY CROSS THE FORECAST AREA...WITH A WANING SEVERE WEATHER THREAT
DUE TO THE LOSS OF DAYTIME HEATING. HAVE KEPT SIMILAR POPS TO THE
PREVIOUS FORECAST PACKAGE...WITH CHANCE POPS ACROSS THE SOUTH AND
LIKELY ACROSS THE NORTH...WHERE BETTER FORCING WOULD BE OCCURRING.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
QUITE A BIT OF VARIABILITY AMONG THE MODELS IN REGARD TO THE SPEED
AND TRACK OF THE SYSTEM EXITING THE AREA ON TUESDAY. THE 12Z NAM IS
THE SLOWEST AND FARTHEST SOUTH...WITH THE SURFACE LOW JUST TO OUR
SOUTHWEST AT 12Z TUESDAY. MEANWHILE THE 12Z GFS IS FASTER AND MUCH
FARTHER NORTH WITH THE LOW. THE 12Z CMC AND ECMWF ARE MORE IN THE
MIDDLE AND WILL TREND THE FORECAST THAT WAY...SLOWING THE END OF
PCPN A BIT THROUGH THE DAY ON TUESDAY. WILL CONTINUE WITH HIGHS ON
TUESDAY IN THE UPPER 70S TO LOWER 80S...BUT THEY MAY END UP BEING A
LITTLE TRICKY DEPENDING ON THE EXACT PLACEMENT/TIMING OF THE LOW AND
RESULTING CLOUD COVER.
SKIES WILL BECOME MOSTLY CLEAR TUESDAY NIGHT INTO WEDNESDAY AS HIGH
PRESSURE BUILDS IN FROM THE WEST. THIS WILL LEAD TO A BRIEF SHOT OF
WEAK CAA WHICH SHOULD HELP KEEP TEMPERATURES DOWN IN THE LOWER TO
POSSIBLY MID 80S ON WEDNESDAY. AS THE HIGH SLIDES OFF TO THE EAST
THROUGH THE DAY ON THURSDAY...WE WILL GET INTO RETURN FLOW...
RESULTING IN THE WARMEST DAY OF THE WEEK WITH HIGHS INTO THE MID TO
UPPER 80S.
THE 00Z ECMWF HAS CONTINUED TO TREND SLOWER WITH THE APPROACH OF THE
NEXT SHORT WAVE FOR LATE IN THE WORK WEEK AND IS NOW ABOUT 18 HOURS
OR SO SLOWER THAN THE 12Z GFS. THE 12Z CMC IS ALSO TRENDING SLOWER
SO HAVE TRIMMED BACK THE ONSET OF PCPN FOR THURSDAY NIGHT...WITH THE
BEST CHANCE ON INTO FRIDAY. IT LOOKS LIKE A PRETTY GOOD CHANE FOR
PCPN SOMETIME THURSDAY NIGHT INTO FRIDAY...BUT GIVEN THE TIMING
ISSUES AM HESITANT TO GO HIGHER THAN CHANCE AT THIS POINT FOR ANY
GIVEN PERIOD. A MUCH COOLER AIRMASS WILL FILTER DOWN INTO OUR AREA
FOR THE WEEKEND AS A 500 MB LOW SETTLES IN OVER THE WESTERN GREAT
LAKES. 850 MB TEMPERATURES WILL DROP DOWN INTO THE 6 TO 8 DEGREE
RANGE AT TIMES SATURDAY INTO SUNDAY. THIS WOULD KEEP HIGHS BOTH DAYS
GENERALLY IN THE LOWER 70S.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
ALTHOUGH A FEW SPRINKLES OR LIGHT SHOWERS ARE POSSIBLE BETWEEN 06Z
AND 08Z (MAINLY AT THE WESTERN TAF SITES)...THE FIRST 8 HOURS OF
THE FORECAST PERIOD APPEAR TO BE RELATIVELY TRANQUIL. MID LEVEL
MOISTURE WILL CONTINUE TO INCREASE OVERNIGHT AND INTO
MONDAY...AND HIGH-RESOLUTION COMPUTER GUIDANCE IS INDICATING THAT
RAIN SHOWERS WILL BE POSSIBLE BY EARLY AFTERNOON FOR THE WESTERN
TAF SITES (AND SLIGHTLY LATER FOR THE COLUMBUS SITES). THIS
ACTIVITY WILL GENERALLY BE DISORGANIZED AND IN THE VFR
CATEGORY...BUT BY LATE AFTERNOON THE DIURNAL CYCLE MAY LEAD TO
SOME HEAVIER SHOWERS. WITH INSTABILITY APPEARING MARGINAL...HAVE
LIMITED THE MENTION OF VCTS TO JUST THE CINCINNATI TAF SITES.
SOME SHOWERS MAY PERSIST INTO MONDAY NIGHT...AS WINDS SHIFT FROM
THE SOUTH TO WEST LATE IN THE FORECAST PERIOD.
.OUTLOOK...THUNDERSTORMS ARE POSSIBLE TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...LATTO
NEAR TERM...AR
SHORT TERM...LATTO
LONG TERM...JGL
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS TULSA OK
1153 PM CDT SUN AUG 12 2012
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
COLD FRONT IS CURRENTLY NEAR A KGMJ-KOKM LINE. SCATTERED
STRONG TO SEVERE THUNDERSTORMS CONTINUE AHEAD OF THE FRONT
ACROSS PORTIONS OF EASTERN OKLAHOMA AND NORTHWEST ARKANSAS...
MAINLY NORTH OF INTERSTATE 40 AND EAST OF US HIGHWAY 69. WILL
GO WITH A TEMPO THUNDER GROUP FOR A COUPLE OF HOURS AT THE
ARKANSAS TAF SITES AS THE COLD FRONT WORKS EAST ACROSS THE AREA.
OTHERWISE...VFR CONDITIONS ARE EXPECTED.
&&
.PREV DISCUSSION... /ISSUED 745 PM CDT SUN AUG 12 2012/
DISCUSSION...
TEXT PRODUCTS WERE UPDATED TO INCLUDE SVR WATCH FOR SE OK. SLOW
MOVING FRONT EXTENDS FROM SE KS DOWN TO THE WEST OF TULSA AND THEN
DOWN INTO SOUTH CENTRAL OK. SEVERE STORMS HAVE ERUPTED OVER SOUTH
CENTRAL OK DOWN WHERE THE BEST INSTABILITY LIES...AND WITH 30KTS
OF 500MB FLOW...THERE IS ENOUGH SHEAR TO FOR SUSTAINED CELLS TO
ROTATE. FAIRLY UNIDIRECTIONAL WNW FLOW ALOFT IS FAVORING SPLITTING
CELLS...AND INDEED A LEFT SPLIT IS MOVING TOWARD PUSHMATAHA COUNTY
AS I TYPE. OTHER CELLS ARE DEVELOPING TO ITS NORTH AS WELL...SO
SOME CELL MERGERS COULD OCCUR AS WELL. VERY LARGE HAIL AND
DAMAGING WINDS WILL BE THE PRIMARY THREATS. WILL CONTINUE TO
MONITOR AREAS TO THE NORTH ALONG THE FRONT...AS THE LATEST RUNS OF
THE HRRR MODEL CONTINUE TO INDICATE SCT DVLPMT THIS EVENING.
LACY
PREV DISCUSSION... /ISSUED 621 PM CDT SUN AUG 12 2012/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
A COLD FRONT IS POISED TO MOVE THROUGH KBVO AND THE TULSA
TAF SITES DURING THE NEXT HOUR OR SO. THE FRONT WILL SLOWLY
WORK THROUGH THE AREA TONIGHT MAKING IT THROUGH FSM AROUND 10Z.
SCATTERED THUNDERSTORMS ARE EXPECTED ALONG AND AHEAD OF THE FRONT
TONIGHT. HAVE GONE WITH TEMPO THUNDER AT KMLC AND VCTS AT THE
ARKANSAS TAF SITES FOR NOW. VFR CONDITIONS ARE EXPECTED ON
MONDAY.
PREV DISCUSSION... /ISSUED 355 PM CDT SUN AUG 12 2012/
DISCUSSION...
A SHORTWAVE CURRENTLY LOCATED OVER THE NORTHERN PLAINS WAS PUSHING
A COLD FRONT THROUGH WESTERN AND CENTRAL OKLAHOMA THIS AFTERNOON.
AHEAD OF THE FRONT...TEMPS HAVE WARMED INTO THE LOW 90S TO AROUND
100 DEGREES WITH BREEZY SOUTHERLY WINDS. THIS FRONT IS EXPECTED TO
ENTER INTO EASTERN OKLAHOMA DURING THE LATE AFTERNOON/EVENING
HOURS AND NORTHWEST ARKANSAS OVERNIGHT. CHANCES FOR SHOWERS AND
THUNDERSTORMS REMAIN PROBABLE ACROSS THE REGION AS THE FRONT
PUSHES THROUGH. TEMPS THIS AFTERNOON ARE WARMING ENOUGH TO DEVELOP
INSTABILITY OVER THE REGION WHICH WILL CREATE THE POTENTIAL FOR
SEVERE THUNDERSTORMS THROUGH THE EVENING HOURS. DAMAGING WINDS AND
LARGE HAIL STILL LOOK TO BE THE MAIN THREATS. WINDS WILL SHIFT OUT
OF THE NORTH-NORTHWEST BEHIND THE FRONTAL PASSAGE...WHICH COULD
CREATE A CONCERN FOR THE FIGHTING OF ANY WILDFIRES. THE COLD FRONT
SHOULD BE NEAR THE RED RIVER VALLEY MONDAY MORNING...WITH MOST OF
THE PRECIP HAVING PUSHED OUT OF THE AREA. WILL LEAVE A SLIGHT
CHANCE POP ACROSS FAR SOUTHEAST OKLAHOMA.
BEHIND THE FRONTAL BOUNDARY...LATEST MODEL SOLUTIONS DEVELOP A MCS
OVER EASTERN COLORADO/WESTERN KANSAS MONDAY NIGHT AND PUSH IT
EAST/SOUTHEASTWARD TUESDAY MORNING. THE LOCATION OF THE MCS
TUESDAY MORNING STILL REMAINS SOME WHAT UNCERTAIN THOUGH ANY
OUTFLOW BOUNDARY COULD PUSH THROUGH THE REGION IF THE MCS STAYS
OVER KANSAS. THUS...WILL CONTINUE CHANCE POPS TUESDAY AND COOLER
TEMP NORTH OF I-40. IF INDICATIONS ARE THAT THE SYSTEM COULD REMAIN
NORTH OF THE REGION...THEN THESE TEMPS WILL NEED TO BE BUMPED BACK
UP.
A PIECE OF ENERGY WITHIN THE NORTHWESTERLY UPPER LEVEL FLOW LOOKS
TO MOVE ACROSS THE SOUTHERN PLAINS TUESDAY AND WEDNESDAY AS WELL
WHICH WILL KEEP POPS IN THE GRIDS THROUGH WEDNESDAY. THE GREATEST
CHANCES FOR SHOWERS AND THUNDERSTORMS CONTINUE TO BE THURSDAY INTO
FRIDAY IN RESPONSE TO A STRONGER COLD FRONT MOVING ACROSS THE
PLAINS. TEMPS BEHIND THIS FRONT SHOULD BE ABLE TO BE BELOW NORMAL
WITH HIGHS IN THE 80S FOR MOST LOCATIONS INTO THE WEEKEND. USED THE
ECMWF FOR DETAILS IN THE EXTENDED PERIODS AS IT CONTINUES TO BE
THE MOST CONSISTENT WITH THIS SYSTEM.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...10
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1046 PM EDT TUE AUG 14 2012
.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION OVERNIGHT REACHING THE COAST BY
THURSDAY. HIGH PRESSURE WILL LINGER OVER OUR REGION WEDNESDAY AND
THURSDAY BEFORE THE NEXT COLD FRONT REACHES OUR AREA FROM THE
NORTHWEST LATE FRIDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 1045 PM...A FEW SHOWERS AND THUNDERSTORMS MAY TRACK ACROSS THE
CWA ALONG AND AHEAD OF A COLD FRONT. I WILL INDICATE CHC TO SCHC
THROUGH THE EARLY MORNING HOURS. I WILL KEEP FOG AND LOW CLOUDS IN
PLACE.
AS OF 8 PM...CONVECTION COVERAGE HAS REMAINED LIMITED SO FAR THIS
EVENING. I WILL UPDATE THE FORECAST TO REDUCE POPS. A COLD FRONT
WILL SLOWLY SLIDE INTO THE REGION OVERNIGHT...I WILL KEEP CHC TO
SCHC POPS. IN ADDITION...AREAS OF RAINFALL THIS EVENING SHOULD BE
PRIMED FOR FOG AND LOW CLOUDS TONIGHT. I WILL UPDATE THE FORECAST TO
INCREASE MENTION OF FOG OVER SATURATED SOIL AND MAKE SOME ADJUSTMENT
TO SKY.
AS OF 530 PM...RECENT RADAR IMAGES INDICATE THAT COVERAGE OF TSRA
HAS BEEN INCREASING ACROSS THE FOOTHILLS OF THE CAROLINAS AND
NORTHEAST GA. LATEST CAPE ANALYSIS INDICATES THAT VALUES RANGE FROM
1500 TO 2000 J/KG ACROSS THE FOOTHILLS AND PIEDMONT...WITH DCAPE
VALUES RANGING FROM 1000 TO 1300 J/KG EAST OF THE MTNS. IN
ADDITION...EFFECTIVE SHEAR RANGES FROM 20 TO 30 KTS. GIVEN THE
ENVIRONMENT...FOOTHILL STORMS SHOULD ORGANIZE IN CLUSTERS...FORM
COLD POOLS...AND TRACK EAST. THE PRIMARY THREAT WILL REMAIN DAMAGING
WINDS...A FEW STRONGER STORMS MAY PRODUCE LARGE HAIL. I WILL UPDATE
THE FORECAST FOR POP PLACEMENT AND TIMING.
AS OF 145 PM...POPS HAD TO BE ADJUSTED AGAIN TO CHASE TRENDS. A
HEALTHY CU FIELD CAN BE SEEN ON VISIBLE...BUT JUST DOESN/T SEEM TO
BE ABLE TO BREAK THRU. THE 13Z HRRR IS THE CLOSEST TO REALITY...AND
IT REALLY ONLY HAS A FEW CELLS DEVELOPING ACRS THE NC MTNS THRU THE
AFTN HOURS. SO POPS WERE PUSHED BACK TO LATE AFTN/EVE...WHICH ARE
PROBABLY STILL OVERDONE. TEMPS ARE STILL LAGGING. ONE THING TO NOTE
IS THAT THE MODIFIED FFC SOUNDING THIS MORNING SHOWED THAT A FCST
MAX TEMP OF 87-89 STILL RESULTED IN SOME CIN. STILL EXPECT A VORT
MAX TO ENTER THE AREA LATER THIS AFTN...AND THAT MAY BE ENUF TO
BREAK THE CAP. WE/LL SEE.
LATER TONIGHT...AS WITH THE CONVECTION...FCST SNDGS AND MOISTURE
PROGS ON THE NAM AND GFS ARE VAGUE ON HOW MUCH CLOUD COVER WILL
LINGER OVERNIGHT. ANOTHER (STRONGER) VORT MAX...CURRENTLY OVER
MO...WILL PROVIDE DECENT QG FORCING LATE TNGT INTO WED MORNING. THIS
FEATURE WILL LIKELY KEEP SOME MID-HIGH CLOUDS AROUND. MEANWHILE...A
COLD FRONT WILL PUSH INTO THE AREA TOWARD DAYBREAK...HELPING KEEP
THINGS MIXED. SO TEMPS WILL BE NEAR NORMAL WITH PROBABLY NOT MUCH IN
THE WAY OF FOG. I ALSO KEEP A LINGERING SLGT CHC TO LOW-END CHC POP
DUE TO THE PASSAGE OF THE VORT MAX.
WEDNESDAY...THE COLD FRONT SHUD BE ABLE TO PUSH THRU THE REST OF THE
CWFA DURING THE DAY. GUIDANCE DOES TRY TO DEVELOP A LITTLE
CONVECTION ACRS MAINLY THE SE ZONES WITH DAYTIME HEATING NEAR THE
FRONT. OTHERWISE...SHUD BE A RELATIVELY DRY DAY WITH DECREASING
CLOUDS AND HIGHS NEAR NORMAL.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
AS OF 245 PM TUESDAY...ZONAL FLOW DEVELOPS FOR THU AS SHORT WAVE
MOVES EAST OF THE AREA. SFC HIGH PRESSURE BUILDS IN AS WELL. EXPECT
DRYING LOW LEVELS AND WARMING MID LEVELS THU HELPING TO CAP THE
ATMOS. SHUD BE A DRY FCST WITH LOWS A LITTLE BELOW NORMAL AND HIGHS
NEAR NORMAL. HEIGHTS FALL FRI AS SHORT WAVES DIVE TOWARD THE AREA.
THIS HELPS PUSH A COLD FRONT FROM THE OH VALLEY TO JUST WEST OF THE
CWFA. LEE TROF DEVELOPS TO HELP PRODUCE LOW LEVEL CONVERGENCE. UPPER
DIVERGENCE BEGINS TO INCREASE AS UPPER JET MOVES TOWARD THE AREA AS
WELL. EXPECT INSTABILITY TO RETURN WITH MOISTENING LOW LEVELS AND
COOLING MID LEVELS. BEST CHC FOR PRECIP WILL BE OVER THE MTNS WHERE
MOISTURE AND FORCING ARE HIGHER...BUT SCT CONVECTION SHUD DEVELOP
ALL AREAS BY LATE AFTERNOON. LOWS THU NITE RISE TO AROUND NORMAL
WITH HIGHS FRIDAY NEAR TO SLIGHTLY ABOVE NORMAL.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 230 PM TUESDAY...MUCH BETTER AGREEMENT BETWEEN THE 12Z GFS AND
THE 00Z ECMWF REGARDING THE DEVELOPING LONG WAVE TROF OVER THE ERN
CONUS THAN BETWEEN THE 06Z GFS AND 00Z ECMWF. AS MENTIONED ABOVE...
LONG WAVE TROF DEVELOPS OVER THE ERN CONUS AND REMAINS IN PLACE THRU
THE PERIOD. A SERIES OF WEAK SHORT WAVES MOVE THRU THE FLOW WITH THE
STRONGEST ON MONDAY. THE GFS THEN SHIFTS THE AXIS OF THE LONG WAVE
EAST ON TUE WHILE THE ECMWF HOLDS IN IN PLACE. AT THE SFC..A COLD
FRONT MOVES ACROSS THE AREA SAT...THEN STALLS TO OUR EAST AND SOUTH
THRU THE PERIOD. THE WAVE ON MONDAY MAY HELP DRAG THE FRONT BACK
TOWARD THE AREA BEFORE IT PUSHES SOUTH AND EAST OF US AGAIN FOR TUE.
GOOD AGREEMENT ON AT LEAST SCT POP SAT WITH THE FRONT...THEN
GUIDANCE DIFFERS FROM DAY TO DAY WITH PRECIP POTENTIAL DEPENDING ON
WHERE ANY WAVES MOVE ALONG THE FRONT AND IF THEY CAN PULL MOISTURE
BACK NORTH INTO THE CWFA. HAVE GONE WITH SCT POP SAT...SLIGHT CHC
SUN/MON THEN DRY TUE. TEMPS REMAIN NEARLY STEADY NEAR TO SLIGHTLY
BELOW NORMAL SAT THRU MON...THEN RISE BACK TO NEAR NORMAL FOR TUE.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT...UPSTREAM CONVECTION REMAINS VERY LIMITED. BASED ON RADAR
TRENDS AND PASSAGE OF A MID LEVEL S/W...I WILL KEEP THE TAF DRY.
SOME GUIDANCE HAS IFR STRATUS DEVELOPING OVER THE TERMINAL AROUND
SUNRISE FOLLOWING A ROUND OF TSRA THIS EVENING. WITHOUT RAINFALL
THIS EVENING...IT APPEARS THAT VFR CONDITIONS WILL CONTINUE THROUGH
TONIGHT. I WILL MENTION 6SM BR BETWEEN 10Z TO 13Z BASED ON CROSSOVER
TEMPERATURES. A COLD FRONT IS EXPECTED TO MOVE ACROSS THE TERMINAL
AROUND SUNRISE. BEHIND THE FRONT...LIGHT NORTHWEST WINDS AND CU
BETWEEN 040 TO 050 IS EXPECTED.
ELSEWHERE...CONVECTION REMAINS VERY LIMITED AT THIS TIME.
HOWEVER...RAINFALL HAS OCCUR AT OR AROUND THE KAVL AND KHKY
TERMINALS. BASED ON RADAR TRENDS AND PASSAGE OF A MID LEVEL S/W...I
WILL KEEP THE KGMU...KGSP...AND KAND TAFS DRY. SOME GUIDANCE HAS IFR
STRATUS DEVELOPING OVER THE TERMINALS AROUND SUNRISE FOLLOWING A
ROUND OF TSRA THIS EVENING. WITHOUT RAINFALL THIS EVENING...IT
APPEARS THAT VFR CONDITIONS WILL CONTINUE THROUGH TONIGHT.
HOWEVER...GIVEN THE APPROACHING FRONT AND RECENT RAINFALL...I WILL
INDICATE IFR CONDITIONS AT KAVL AND KHKY LATE TONIGHT THROUGH 14Z. A
COLD FRONT IS EXPECTED TO MOVE EAST OF THE MTNS AROUND SUNRISE.
BEHIND THE FRONT...LIGHT NORTHWEST WINDS AND CU BETWEEN 040 TO 060
IS EXPECTED.
OUTLOOK...THE CENTER OF SURFACE HIGH PRESSURE WILL SETTLE OVER THE
REGION ON WEDNESDAY AND REMAIN THROUGH THE WORK WEEK. A COLD FRONT
WILL BRING SOME MOISTURE TO THE AREA LATE FRIDAY INTO SATURDAY.
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...PAT
NEAR TERM...NED
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...NED
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
803 PM EDT TUE AUG 14 2012
.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION OVERNIGHT REACHING THE COAST BY
THURSDAY. HIGH PRESSURE WILL LINGER OVER OUR REGION WEDNESDAY AND
THURSDAY BEFORE THE NEXT COLD FRONT REACHES OUR AREA FROM THE
NORTHWEST LATE FRIDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 8 PM...CONVECTION COVERAGE HAS REMAINED LIMITED SO FAR THIS
EVENING. I WILL UPDATE THE FORECAST TO REDUCE POPS. A COLD FRONT
WILL SLOWLY SLIDE INTO THE REGION OVERNIGHT...I WILL KEEP CHC TO
SCHC POPS. IN ADDITION...AREAS OF RAINFALL THIS EVENING SHOULD BE
PRIMED FOR FOG AND LOW CLOUDS TONIGHT. I WILL UPDATE THE FORECAST TO
INCREASE MENTION OF FOG OVER SATURATED SOIL AND MAKE SOME ADJUSTMENT
TO SKY.
AS OF 530 PM...RECENT RADAR IMAGES INDICATE THAT COVERAGE OF TSRA
HAS BEEN INCREASING ACROSS THE FOOTHILLS OF THE CAROLINAS AND
NORTHEAST GA. LATEST CAPE ANALYSIS INDICATES THAT VALUES RANGE FROM
1500 TO 2000 J/KG ACROSS THE FOOTHILLS AND PIEDMONT...WITH DCAPE
VALUES RANGING FROM 1000 TO 1300 J/KG EAST OF THE MTNS. IN
ADDITION...EFFECTIVE SHEAR RANGES FROM 20 TO 30 KTS. GIVEN THE
ENVIRONMENT...FOOTHILL STORMS SHOULD ORGANIZE IN CLUSTERS...FORM
COLD POOLS...AND TRACK EAST. THE PRIMARY THREAT WILL REMAIN DAMAGING
WINDS...A FEW STRONGER STORMS MAY PRODUCE LARGE HAIL. I WILL UPDATE
THE FORECAST FOR POP PLACEMENT AND TIMING.
AS OF 145 PM...POPS HAD TO BE ADJUSTED AGAIN TO CHASE TRENDS. A
HEALTHY CU FIELD CAN BE SEEN ON VISIBLE...BUT JUST DOESN/T SEEM TO
BE ABLE TO BREAK THRU. THE 13Z HRRR IS THE CLOSEST TO REALITY...AND
IT REALLY ONLY HAS A FEW CELLS DEVELOPING ACRS THE NC MTNS THRU THE
AFTN HOURS. SO POPS WERE PUSHED BACK TO LATE AFTN/EVE...WHICH ARE
PROBABLY STILL OVERDONE. TEMPS ARE STILL LAGGING. ONE THING TO NOTE
IS THAT THE MODIFIED FFC SOUNDING THIS MORNING SHOWED THAT A FCST
MAX TEMP OF 87-89 STILL RESULTED IN SOME CIN. STILL EXPECT A VORT
MAX TO ENTER THE AREA LATER THIS AFTN...AND THAT MAY BE ENUF TO
BREAK THE CAP. WE/LL SEE.
LATER TONIGHT...AS WITH THE CONVECTION...FCST SNDGS AND MOISTURE
PROGS ON THE NAM AND GFS ARE VAGUE ON HOW MUCH CLOUD COVER WILL
LINGER OVERNIGHT. ANOTHER (STRONGER) VORT MAX...CURRENTLY OVER
MO...WILL PROVIDE DECENT QG FORCING LATE TNGT INTO WED MORNING. THIS
FEATURE WILL LIKELY KEEP SOME MID-HIGH CLOUDS AROUND. MEANWHILE...A
COLD FRONT WILL PUSH INTO THE AREA TOWARD DAYBREAK...HELPING KEEP
THINGS MIXED. SO TEMPS WILL BE NEAR NORMAL WITH PROBABLY NOT MUCH IN
THE WAY OF FOG. I ALSO KEEP A LINGERING SLGT CHC TO LOW-END CHC POP
DUE TO THE PASSAGE OF THE VORT MAX.
WEDNESDAY...THE COLD FRONT SHUD BE ABLE TO PUSH THRU THE REST OF THE
CWFA DURING THE DAY. GUIDANCE DOES TRY TO DEVELOP A LITTLE
CONVECTION ACRS MAINLY THE SE ZONES WITH DAYTIME HEATING NEAR THE
FRONT. OTHERWISE...SHUD BE A RELATIVELY DRY DAY WITH DECREASING
CLOUDS AND HIGHS NEAR NORMAL.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
AS OF 245 PM TUESDAY...ZONAL FLOW DEVELOPS FOR THU AS SHORT WAVE
MOVES EAST OF THE AREA. SFC HIGH PRESSURE BUILDS IN AS WELL. EXPECT
DRYING LOW LEVELS AND WARMING MID LEVELS THU HELPING TO CAP THE
ATMOS. SHUD BE A DRY FCST WITH LOWS A LITTLE BELOW NORMAL AND HIGHS
NEAR NORMAL. HEIGHTS FALL FRI AS SHORT WAVES DIVE TOWARD THE AREA.
THIS HELPS PUSH A COLD FRONT FROM THE OH VALLEY TO JUST WEST OF THE
CWFA. LEE TROF DEVELOPS TO HELP PRODUCE LOW LEVEL CONVERGENCE. UPPER
DIVERGENCE BEGINS TO INCREASE AS UPPER JET MOVES TOWARD THE AREA AS
WELL. EXPECT INSTABILITY TO RETURN WITH MOISTENING LOW LEVELS AND
COOLING MID LEVELS. BEST CHC FOR PRECIP WILL BE OVER THE MTNS WHERE
MOISTURE AND FORCING ARE HIGHER...BUT SCT CONVECTION SHUD DEVELOP
ALL AREAS BY LATE AFTERNOON. LOWS THU NITE RISE TO AROUND NORMAL
WITH HIGHS FRIDAY NEAR TO SLIGHTLY ABOVE NORMAL.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 230 PM TUESDAY...MUCH BETTER AGREEMENT BETWEEN THE 12Z GFS AND
THE 00Z ECMWF REGARDING THE DEVELOPING LONG WAVE TROF OVER THE ERN
CONUS THAN BETWEEN THE 06Z GFS AND 00Z ECMWF. AS MENTIONED ABOVE...
LONG WAVE TROF DEVELOPS OVER THE ERN CONUS AND REMAINS IN PLACE THRU
THE PERIOD. A SERIES OF WEAK SHORT WAVES MOVE THRU THE FLOW WITH THE
STRONGEST ON MONDAY. THE GFS THEN SHIFTS THE AXIS OF THE LONG WAVE
EAST ON TUE WHILE THE ECMWF HOLDS IN IN PLACE. AT THE SFC..A COLD
FRONT MOVES ACROSS THE AREA SAT...THEN STALLS TO OUR EAST AND SOUTH
THRU THE PERIOD. THE WAVE ON MONDAY MAY HELP DRAG THE FRONT BACK
TOWARD THE AREA BEFORE IT PUSHES SOUTH AND EAST OF US AGAIN FOR TUE.
GOOD AGREEMENT ON AT LEAST SCT POP SAT WITH THE FRONT...THEN
GUIDANCE DIFFERS FROM DAY TO DAY WITH PRECIP POTENTIAL DEPENDING ON
WHERE ANY WAVES MOVE ALONG THE FRONT AND IF THEY CAN PULL MOISTURE
BACK NORTH INTO THE CWFA. HAVE GONE WITH SCT POP SAT...SLIGHT CHC
SUN/MON THEN DRY TUE. TEMPS REMAIN NEARLY STEADY NEAR TO SLIGHTLY
BELOW NORMAL SAT THRU MON...THEN RISE BACK TO NEAR NORMAL FOR TUE.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT...UPSTREAM CONVECTION REMAINS VERY LIMITED. BASED ON RADAR
TRENDS AND PASSAGE OF A MID LEVEL S/W...I WILL KEEP THE TAF DRY.
SOME GUIDANCE HAS IFR STRATUS DEVELOPING OVER THE TERMINAL AROUND
SUNRISE FOLLOWING A ROUND OF TSRA THIS EVENING. WITHOUT RAINFALL
THIS EVENING...IT APPEARS THAT VFR CONDITIONS WILL CONTINUE THROUGH
TONIGHT. I WILL MENTION 6SM BR BETWEEN 10Z TO 13Z BASED ON CROSSOVER
TEMPERATURES. A COLD FRONT IS EXPECTED TO MOVE ACROSS THE TERMINAL
AROUND SUNRISE. BEHIND THE FRONT...LIGHT NORTHWEST WINDS AND CU
BETWEEN 040 TO 050 IS EXPECTED.
ELSEWHERE...CONVECTION REMAINS VERY LIMITED AT THIS TIME.
HOWEVER...RAINFALL HAS OCCUR AT OR AROUND THE KAVL AND KHKY
TERMINALS. BASED ON RADAR TRENDS AND PASSAGE OF A MID LEVEL S/W...I
WILL KEEP THE KGMU...KGSP...AND KAND TAFS DRY. SOME GUIDANCE HAS IFR
STRATUS DEVELOPING OVER THE TERMINALS AROUND SUNRISE FOLLOWING A
ROUND OF TSRA THIS EVENING. WITHOUT RAINFALL THIS EVENING...IT
APPEARS THAT VFR CONDITIONS WILL CONTINUE THROUGH TONIGHT.
HOWEVER...GIVEN THE APPROACHING FRONT AND RECENT RAINFALL...I WILL
INDICATE IFR CONDITIONS AT KAVL AND KHKY LATE TONIGHT THROUGH 14Z. A
COLD FRONT IS EXPECTED TO MOVE EAST OF THE MTNS AROUND SUNRISE.
BEHIND THE FRONT...LIGHT NORTHWEST WINDS AND CU BETWEEN 040 TO 060
IS EXPECTED.
OUTLOOK...THE CENTER OF SURFACE HIGH PRESSURE WILL SETTLE OVER THE
REGION ON WEDNESDAY AND REMAIN THROUGH THE WORK WEEK. A COLD FRONT
WILL BRING SOME MOISTURE TO THE AREA LATE FRIDAY INTO SATURDAY.
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...PAT
NEAR TERM...NED
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...NED
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
546 PM EDT MON AUG 13 2012
.SYNOPSIS...
A COLD FRONT WILL APPROACH THE AREA FROM THE NORTHWEST TONIGHT AS
HIGH PRESSURE MOVES OFF THE ATLANTIC COAST. THIS FRONT WILL CROSS
OUR REGION LATE TUESDAY FOLLOWED BY HIGH PRESSURE WEDNESDAY AND
THURSDAY. ANOTHER COLD FRONT IS EXPECTED TO CROSS THE AREA LATE IN
THE WEEK.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS OF 545 PM...RECENT RADAR IMAGES INDICATE A WEAKENING LINE OF
SHOWERS AND EMBEDDED TSRA ACROSS EASTERN TN AND NRN GA. RECENT IR
SATELLITE IMAGES INDICATE THAT CLOUD TOP TEMPERATURES ARE WARMING
STEADILY WITH CLOUD TO GROUND LIGHTNING COUNTS DECREASING
SIGNIFICANTLY. HOWEVER...THE BAND SHOULD SURVIVE TO PRODUCE
MEASURABLE RAINFALL ACROSS THE WESTERN NC MTNS AND NE GA THROUGH
EARLY THIS EVENING. BASED ON RADAR AND SATELLITE TRENDS AND THE
CURRENT TEMPERATURE PROFILES...IT APPEARS THAT RAINFALL WILL
DISSIPATE RAPIDLY EAST OF THE SAVANNAH AND FRENCH BROAD RIVER
VALLEYS.
AS OF 430 PM...A BROAD NORTH TO SOUTH ORIENTED LINE OF SHOWERS AND
THUNDERSTORMS WAS LOCATED ALONG THE NORTHERN BORDER BETWEEN AL AND
GA. THE LINE IS PUSHING EAST INTO WEAKLY UNSTABLE AIR...WITH THE
LATEST CAPE ANALYSIS INDICATING ONLY 100 J/KG OF CAPE OVER THE
WESTERN NC MTNS. BASED ON THE RADAR TRENDS...LIGHTNING RATES...AND
RATE OF WARMING CLOUD TOP TEMPERATURES...A BAND OF FADING CONVECTION
WILL REACH THE WESTERN NC MTNS BEFORE TOTALLY DISSIPATING DURING THE
LATE EVENING. I WILL INCREASE POPS TO CHC ACROSS THE WESTERN NC MTNS
AND HIGHLIGHT GENERAL THUNDERSTORMS IN THE HWO. I WILL ALSO UPDATE
THE FORECAST TO ALIGN TEMPS AND DWPTS WITH OBSERVATIONS.
AS OF 145 PM...THE MAIN THING OF CONCERN FOR THIS UPDATE IS A LINE
OF CONVECTION CROSSING CENTRAL TN AND AL ATTM. THE MODELS DO NOT
SEEM TO BE HANDLING THIS VERY WELL. ATTM...IT STILL LOOKED LIKE THE
LINE WILL LOSE STEAM AS IT ENCOUNTERS STABLE AIR OVER ERN TN AND GA.
WITH THAT SAID...THE LATEST RAP BRINGS INSTBY WITH THE LINE (AS IT
IS NOT MOVING VERY FAST)...SUCH THAT THE SW NC MTNS DO DEVELOP ABOUT
1000-1500 J/KG OF CAPE BY 23Z AS THE LINE ARRIVES. THE CONVECTION
WILL HAVE THE ASSOCIATED MCV TO HELP WITH FORCING AS WELL. SO
ANOTHER UPDATE MAY BE NEEDED SHORTLY TO BUMP UP POP THERE. FOR
SURE...THE MOISTURE WILL SPREAD IN THIS EVENING/OVERNIGHT BRINGING
MAINLY MID AND HIGH CLOUDS. SOME SHWRS MAY SURVIVE INTO THE NC MTNS
THRU DAYBREAK. TEMPS ARE STILL FCST TO DROP TO NORMAL OR EVEN A
CATEGORY BELOW (THO THOSE MAY BE TOO COOL GIVEN EXPECTED CLOUD
COVER).
TUESDAY...A SHORTWAVE TROF WILL ROUND THE BASE OF THE LONGWAVE TROF
AXIS INVOF THE OH/TN VLYS. MEANWHILE...AN ASSOCIATED SFC LOW WILL
TRACK FROM THE MID MS VLY TO AROUND LAKE ERIE BY TUESDAY EVENING.
THE LOW PRES SYSTEM WILL PUSH A COLD FRONT ACRS THE OH/TN VLYS ON
TUESDAY...WITH PRE-FRONTAL BAND OF MOISTURE CROSSING THE CWFA.
GUIDANCE IN GOOD AGREEMENT OF HIGH-END CHC POPS FOR MOST OF THE AREA
WITH DECENT INSTBY AND NOMINAL BULK SHEAR. LLVL CONVERGENCE AND UPR
SUPPORT DO NOT LOOK THAT IMPRESSIVE. SO NOT EXPECTING TOO MUCH
ORGANIZATION. HOWEVER...A FEW SEVERE STORM CLUSTERS WILL BE POSSIBLE
TUESDAY AFTN. TEMPS WILL BE ONE TO TWO CATEGORIES BELOW NORMAL UNDER
MOSTLY CLOUDY SKIES.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
AS OF 245 PM MONDAY...A SHORT WAVE SWINGS ACROSS THE AREA TUE NITE
THEN EAST ON WED...LEAVING NEARLY ZONAL FLOW IN ITS WAKE FOR THU. AT
THE SFC...A COLD FRONT MOVES THRU WITH THE WAVE TUE NITE THEN EAST
OF THE AREA WED AS WELL. HIGH PRESSURE BUILDS IN FOR THU. EXPECT SCT
CONVECTION TO BE ONGOING TUE EVENING WHICH THEN DISSIPATES OVERNIGHT
WITH LOSS OF INSTABILITY. HOWEVER...ISOLATED SHRA COULD LINGER OVER
THE EAST NEAR THE FRONT AND OVER THE MTNS IN THE DEVELOPING WLY FLOW
AND LINGERING LOW LEVEL MOISTURE. ATMOS BECOMES CAPPED WED WITH
WARMER MID LEVEL TEMPS AND DIMINISHING LOW LEVEL MOISTURE IN THE
DEVELOPING WLY FLOW. TEMPS NEAR NORMAL TUE NITE AND WED. ATMOS
REMAINS CAPPED THU AS RELATIVELY WARM MID LEVEL TEMPS CONTINUE. LOW
LEVEL MOISTURE WILL BE LIMITED AS WELL. HOWEVER...ENUF H85 MOISTURE
WILL BE AROUND FOR A DECENT CU FIELD TO DEVELOP DURING THE
AFTERNOON. THEREFORE...HAVE A CONTINUED DRY FCST WITH LOWS FALLING A
LITTLE BELOW NORMAL BUT HIGHS REMAINING NEARLY STEADY AROUND NORMAL.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 230 PM EDT MONDAY...THE LATEST MEDIUM RANGE MODELS INDICATE
THAT A WEAK RIDGE OF HIGH OVER OUR AREA MOVES OFF TO THE EAST ON
LATE THURSDAY AS A COLD FRONT AND ASSOCIATED UPPER TROUGH OVER THE
GREAT LAKES REGION DIGS SOUTH INTO TN/OH. THE FRONT IS EXPECTED TO
SLIP FURTHER SOUTH INTO THE APPALACHIANS BY FRIDAY AND CROSSES OUR
CWA ON SATURDAY. WITH DEEPENING MOISTURE...MODERATE INSTABILITY
AND UPPER LEVEL DIVERGENCE...WILL INCREASE POPS INTO THE 30-40
PERCENT RANGE FRI/SAT. SOME THUNDERSTORMS COULD BE SEVERE ON
SATURDAY MAINLY OVER THE BLUE RIDGE AND NORTH CAROLINA PIEDMONT AS
MODEL SOUNDINGS SHOW FAIRLY STRONG 0-6KM BULK WIND SHEAR MAGNITUDE
OF +30KT AND MODERATE CAPE VALUES THERE. AS THE FRONT MOVES OFF TO
THE EAST...HIGH PRESSURE WILL BUILD IN FROM THE NORTHWEST SUNDAY AND
REMAIN THROUGH MONDAY. TEMPERATURES WILL REMAIN 3 TO 5 DEGREES BELOW
NORMAL WITH AFTERNOON HIGHS IN THE LOW TO MID 80S DURING THE PERIOD.
&&
.AVIATION /22Z MONDAY THROUGH SATURDAY/...
AT KCLT...FAIR WX (VFR CONDITIONS) EXPECTED THRU THE PERIOD WITH A
LIGHT SLY/SWLY WIND. MOISTURE WILL GRADUALLY INCREASE FROM THE WEST
OVERNIGHT THRU TUESDAY MORNING (GENERALLY MID AND UPR LVL).
CONVECTION WILL APPROACH FROM THE WEST AS WELL...BUT NOT EXPECTING
ANY CONVECTION AT KCLT THRU 18Z TUESDAY AT THIS TIME.
ELSEWHERE...FAIR WX CU AND INCREASING MID AND HIGH CLOUDS INTO THIS
EVENING. THE VFR CLOUDS MAY LIMIT ANY FOG/STRATUS DEVELOP...ALTHOUGH
LLVL MOISTURE WILL ALSO INCREASE FROM THE WEST LATE TNGT. LEFT OUT
ANY MENTION OF RESTRICTIONS FOR NOW. CONVECTION WILL ALSO BE
POSSIBLE WITH THIS MOISTURE BY MIDDAY TUESDAY...SO PROB30 ALREADY
ADDED FOR LAST 2-3 HOURS OF TAFS FOR KAVL/KHKY/KAND. LESS CONFIDENT
FOR KGSP/KGMU AT THIS TIME.
OUTLOOK...A SLOW MOVING COLD FRONT IS EXPECTED TO CROSS THE SOUTHERN
APPALACHIAN REGION TUESDAY AFTERNOON THROUGH TUESDAY
NIGHT...BRINGING A CHC FOR SHRA/TSRA. THE CENTER OF SURFACE HIGH
PRESSURE WILL SETTLE OVER THE REGION ON WEDNESDAY AND REMAIN THROUGH
THE WORK WEEK.
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...JOH
NEAR TERM...NED
SHORT TERM...RWH
LONG TERM...JOH
AVIATION...ARK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
432 PM EDT MON AUG 13 2012
.SYNOPSIS...
A COLD FRONT WILL APPROACH THE AREA FROM THE NORTHWEST TONIGHT AS
HIGH PRESSURE MOVES OFF THE ATLANTIC COAST. THIS FRONT WILL CROSS
OUR REGION LATE TUESDAY FOLLOWED BY HIGH PRESSURE WEDNESDAY AND
THURSDAY. ANOTHER COLD FRONT IS EXPECTED TO CROSS THE AREA LATE IN
THE WEEK.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS OF 430 PM...A BROAD NORTH TO SOUTH ORIENTED LINE OF SHOWERS AND
THUNDERSTORMS WAS LOCATED ALONG THE NORTHERN BORDER BETWEEN AL AND
GA. THE LINE IS PUSHING EAST INTO WEAKLY UNSTABLE AIR...WITH THE
LATEST CAPE ANALYSIS INDICATING ONLY 100 J/KG OF CAPE OVER THE
WESTERN NC MTNS. BASED ON THE RADAR TRENDS...LIGHTNING RATES...AND
RATE OF WARMING CLOUD TOP TEMPERATURES...A BAND OF FADING CONVECTION
WILL REACH THE WESTERN NC MTNS BEFORE TOTALLY DISSIPATING DURING THE
LATE EVENING. I WILL INCREASE POPS TO CHC ACROSS THE WESTERN NC MTNS
AND HIGHLIGHT GENERAL THUNDERSTORMS IN THE HWO. I WILL ALSO UPDATE
THE FORECAST TO ALIGN TEMPS AND DWPTS WITH OBSERVATIONS.
AS OF 145 PM...THE MAIN THING OF CONCERN FOR THIS UPDATE IS A LINE
OF CONVECTION CROSSING CENTRAL TN AND AL ATTM. THE MODELS DO NOT
SEEM TO BE HANDLING THIS VERY WELL. ATTM...IT STILL LOOKED LIKE THE
LINE WILL LOSE STEAM AS IT ENCOUNTERS STABLE AIR OVER ERN TN AND GA.
WITH THAT SAID...THE LATEST RAP BRINGS INSTBY WITH THE LINE (AS IT
IS NOT MOVING VERY FAST)...SUCH THAT THE SW NC MTNS DO DEVELOP ABOUT
1000-1500 J/KG OF CAPE BY 23Z AS THE LINE ARRIVES. THE CONVECTION
WILL HAVE THE ASSOCIATED MCV TO HELP WITH FORCING AS WELL. SO
ANOTHER UPDATE MAY BE NEEDED SHORTLY TO BUMP UP POP THERE. FOR
SURE...THE MOISTURE WILL SPREAD IN THIS EVENING/OVERNIGHT BRINGING
MAINLY MID AND HIGH CLOUDS. SOME SHWRS MAY SURVIVE INTO THE NC MTNS
THRU DAYBREAK. TEMPS ARE STILL FCST TO DROP TO NORMAL OR EVEN A
CATEGORY BELOW (THO THOSE MAY BE TOO COOL GIVEN EXPECTED CLOUD
COVER).
TUESDAY...A SHORTWAVE TROF WILL ROUND THE BASE OF THE LONGWAVE TROF
AXIS INVOF THE OH/TN VLYS. MEANWHILE...AN ASSOCIATED SFC LOW WILL
TRACK FROM THE MID MS VLY TO AROUND LAKE ERIE BY TUESDAY EVENING.
THE LOW PRES SYSTEM WILL PUSH A COLD FRONT ACRS THE OH/TN VLYS ON
TUESDAY...WITH PRE-FRONTAL BAND OF MOISTURE CROSSING THE CWFA.
GUIDANCE IN GOOD AGREEMENT OF HIGH-END CHC POPS FOR MOST OF THE AREA
WITH DECENT INSTBY AND NOMINAL BULK SHEAR. LLVL CONVERGENCE AND UPR
SUPPORT DO NOT LOOK THAT IMPRESSIVE. SO NOT EXPECTING TOO MUCH
ORGANIZATION. HOWEVER...A FEW SEVERE STORM CLUSTERS WILL BE POSSIBLE
TUESDAY AFTN. TEMPS WILL BE ONE TO TWO CATEGORIES BELOW NORMAL UNDER
MOSTLY CLOUDY SKIES.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
AS OF 245 PM MONDAY...A SHORT WAVE SWINGS ACROSS THE AREA TUE NITE
THEN EAST ON WED...LEAVING NEARLY ZONAL FLOW IN ITS WAKE FOR THU. AT
THE SFC...A COLD FRONT MOVES THRU WITH THE WAVE TUE NITE THEN EAST
OF THE AREA WED AS WELL. HIGH PRESSURE BUILDS IN FOR THU. EXPECT SCT
CONVECTION TO BE ONGOING TUE EVENING WHICH THEN DISSIPATES OVERNIGHT
WITH LOSS OF INSTABILITY. HOWEVER...ISOLATED SHRA COULD LINGER OVER
THE EAST NEAR THE FRONT AND OVER THE MTNS IN THE DEVELOPING WLY FLOW
AND LINGERING LOW LEVEL MOISTURE. ATMOS BECOMES CAPPED WED WITH
WARMER MID LEVEL TEMPS AND DIMINISHING LOW LEVEL MOISTURE IN THE
DEVELOPING WLY FLOW. TEMPS NEAR NORMAL TUE NITE AND WED. ATMOS
REMAINS CAPPED THU AS RELATIVELY WARM MID LEVEL TEMPS CONTINUE. LOW
LEVEL MOISTURE WILL BE LIMITED AS WELL. HOWEVER...ENUF H85 MOISTURE
WILL BE AROUND FOR A DECENT CU FIELD TO DEVELOP DURING THE
AFTERNOON. THEREFORE...HAVE A CONTINUED DRY FCST WITH LOWS FALLING A
LITTLE BELOW NORMAL BUT HIGHS REMAINING NEARLY STEADY AROUND NORMAL.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 230 PM EDT MONDAY...THE LATEST MEDIUM RANGE MODELS INDICATE
THAT A WEAK RIDGE OF HIGH OVER OUR AREA MOVES OFF TO THE EAST ON
LATE THURSDAY AS A COLD FRONT AND ASSOCIATED UPPER TROUGH OVER THE
GREAT LAKES REGION DIGS SOUTH INTO TN/OH. THE FRONT IS EXPECTED TO
SLIP FURTHER SOUTH INTO THE APPALACHIANS BY FRIDAY AND CROSSES OUR
CWA ON SATURDAY. WITH DEEPENING MOISTURE...MODERATE INSTABILITY
AND UPPER LEVEL DIVERGENCE...WILL INCREASE POPS INTO THE 30-40
PERCENT RANGE FRI/SAT. SOME THUNDERSTORMS COULD BE SEVERE ON
SATURDAY MAINLY OVER THE BLUE RIDGE AND NORTH CAROLINA PIEDMONT AS
MODEL SOUNDINGS SHOW FAIRLY STRONG 0-6KM BULK WIND SHEAR MAGNITUDE
OF +30KT AND MODERATE CAPE VALUES THERE. AS THE FRONT MOVES OFF TO
THE EAST...HIGH PRESSURE WILL BUILD IN FROM THE NORTHWEST SUNDAY AND
REMAIN THROUGH MONDAY. TEMPERATURES WILL REMAIN 3 TO 5 DEGREES BELOW
NORMAL WITH AFTERNOON HIGHS IN THE LOW TO MID 80S DURING THE PERIOD.
&&
.AVIATION /21Z MONDAY THROUGH SATURDAY/...
AT KCLT...FAIR WX (VFR CONDITIONS) EXPECTED THRU THE PERIOD WITH A
LIGHT SLY/SWLY WIND. MOISTURE WILL GRADUALLY INCREASE FROM THE WEST
OVERNIGHT THRU TUESDAY MORNING (GENERALLY MID AND UPR LVL).
CONVECTION WILL APPROACH FROM THE WEST AS WELL...BUT NOT EXPECTING
ANY CONVECTION AT KCLT THRU 18Z TUESDAY AT THIS TIME.
ELSEWHERE...FAIR WX CU AND INCREASING MID AND HIGH CLOUDS INTO THIS
EVENING. THE VFR CLOUDS MAY LIMIT ANY FOG/STRATUS DEVELOP...ALTHOUGH
LLVL MOISTURE WILL ALSO INCREASE FROM THE WEST LATE TNGT. LEFT OUT
ANY MENTION OF RESTRICTIONS FOR NOW. CONVECTION WILL ALSO BE
POSSIBLE WITH THIS MOISTURE BY MIDDAY TUESDAY...SO PROB30 ALREADY
ADDED FOR LAST 2-3 HOURS OF TAFS FOR KAVL/KHKY/KAND. LESS CONFIDENT
FOR KGSP/KGMU AT THIS TIME.
OUTLOOK...A SLOW MOVING COLD FRONT IS EXPECTED TO CROSS THE SOUTHERN
APPALACHIAN REGION TUESDAY AFTERNOON THROUGH TUESDAY
NIGHT...BRINGING A CHC FOR SHRA/TSRA. THE CENTER OF SURFACE HIGH
PRESSURE WILL SETTLE OVER THE REGION ON WEDNESDAY AND REMAIN THROUGH
THE WORK WEEK.
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...JOH
NEAR TERM...NED
SHORT TERM...RWH
LONG TERM...JOH
AVIATION...ARK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
320 PM EDT MON AUG 13 2012
.SYNOPSIS...
A COLD FRONT WILL APPROACH THE AREA FROM THE NORTHWEST TONIGHT AS
HIGH PRESSURE MOVES OFF THE ATLANTIC COAST. THIS FRONT WILL CROSS
OUR REGION LATE TUESDAY FOLLOWED BY HIGH PRESSURE WEDNESDAY AND
THURSDAY. ANOTHER COLD FRONT IS EXPECTED TO CROSS THE AREA LATE IN
THE WEEK.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS OF 145 PM...THE MAIN THING OF CONCERN FOR THIS UPDATE IS A LINE
OF CONVECTION CROSSING CENTRAL TN AND AL ATTM. THE MODELS DO NOT
SEEM TO BE HANDLING THIS VERY WELL. ATTM...IT STILL LOOKED LIKE THE
LINE WILL LOSE STEAM AS IT ENCOUNTERS STABLE AIR OVER ERN TN AND GA.
WITH THAT SAID...THE LATEST RAP BRINGS INSTBY WITH THE LINE (AS IT
IS NOT MOVING VERY FAST)...SUCH THAT THE SW NC MTNS DO DEVELOP ABOUT
1000-1500 J/KG OF CAPE BY 23Z AS THE LINE ARRIVES. THE CONVECTION
WILL HAVE THE ASSOCIATED MCV TO HELP WITH FORCING AS WELL. SO
ANOTHER UPDATE MAY BE NEEDED SHORTLY TO BUMP UP POP THERE. FOR
SURE...THE MOISTURE WILL SPREAD IN THIS EVENING/OVERNIGHT BRINGING
MAINLY MID AND HIGH CLOUDS. SOME SHWRS MAY SURVIVE INTO THE NC MTNS
THRU DAYBREAK. TEMPS ARE STILL FCST TO DROP TO NORMAL OR EVEN A
CATEGORY BELOW (THO THOSE MAY BE TOO COOL GIVEN EXPECTED CLOUD
COVER).
TUESDAY...A SHORTWAVE TROF WILL ROUND THE BASE OF THE LONGWAVE TROF
AXIS INVOF THE OH/TN VLYS. MEANWHILE...AN ASSOCIATED SFC LOW WILL
TRACK FROM THE MID MS VLY TO AROUND LAKE ERIE BY TUESDAY EVENING.
THE LOW PRES SYSTEM WILL PUSH A COLD FRONT ACRS THE OH/TN VLYS ON
TUESDAY...WITH PRE-FRONTAL BAND OF MOISTURE CROSSING THE CWFA.
GUIDANCE IN GOOD AGREEMENT OF HIGH-END CHC POPS FOR MOST OF THE AREA
WITH DECENT INSTBY AND NOMINAL BULK SHEAR. LLVL CONVERGENCE AND UPR
SUPPORT DO NOT LOOK THAT IMPRESSIVE. SO NOT EXPECTING TOO MUCH
ORGANIZATION. HOWEVER...A FEW SEVERE STORM CLUSTERS WILL BE POSSIBLE
TUESDAY AFTN. TEMPS WILL BE ONE TO TWO CATEGORIES BELOW NORMAL UNDER
MOSTLY CLOUDY SKIES.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
AS OF 245 PM MONDAY...A SHORT WAVE SWINGS ACROSS THE AREA TUE NITE
THEN EAST ON WED...LEAVING NEARLY ZONAL FLOW IN ITS WAKE FOR THU. AT
THE SFC...A COLD FRONT MOVES THRU WITH THE WAVE TUE NITE THEN EAST
OF THE AREA WED AS WELL. HIGH PRESSURE BUILDS IN FOR THU. EXPECT SCT
CONVECTION TO BE ONGOING TUE EVENING WHICH THEN DISSIPATES OVERNIGHT
WITH LOSS OF INSTABILITY. HOWEVER...ISOLATED SHRA COULD LINGER OVER
THE EAST NEAR THE FRONT AND OVER THE MTNS IN THE DEVELOPING WLY FLOW
AND LINGERING LOW LEVEL MOISTURE. ATMOS BECOMES CAPPED WED WITH
WARMER MID LEVEL TEMPS AND DIMINISHING LOW LEVEL MOISTURE IN THE
DEVELOPING WLY FLOW. TEMPS NEAR NORMAL TUE NITE AND WED. ATMOS
REMAINS CAPPED THU AS RELATIVELY WARM MID LEVEL TEMPS CONTINUE. LOW
LEVEL MOISTURE WILL BE LIMITED AS WELL. HOWEVER...ENUF H85 MOISTURE
WILL BE AROUND FOR A DECENT CU FIELD TO DEVELOP DURING THE
AFTERNOON. THEREFORE...HAVE A CONTINUED DRY FCST WITH LOWS FALLING A
LITTLE BELOW NORMAL BUT HIGHS REMAINING NEARLY STEADY AROUND NORMAL.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 230 PM EDT MONDAY...THE LATEST MEDIUM RANGE MODELS INDICATE
THAT A WEAK RIDGE OF HIGH OVER OUR AREA MOVES OFF TO THE EAST ON
LATE THURSDAY AS A COLD FRONT AND ASSOCIATED UPPER TROUGH OVER THE
GREAT LAKES REGION DIGS SOUTH INTO TN/OH. THE FRONT IS EXPECTED TO
SLIP FURTHER SOUTH INTO THE APPALACHIANS BY FRIDAY AND CROSSES OUR
CWA ON SATURDAY. WITH DEEPENING MOISTURE...MODERATE INSTABILITY
AND UPPER LEVEL DIVERGENCE...WILL INCREASE POPS INTO THE 30-40
PERCENT RANGE FRI/SAT. SOME THUNDERSTORMS COULD BE SEVERE ON
SATURDAY MAINLY OVER THE BLUE RIDGE AND NORTH CAROLINA PIEDMONT AS
MODEL SOUNDINGS SHOW FAIRLY STRONG 0-6KM BULK WIND SHEAR MAGNITUDE
OF +30KT AND MODERATE CAPE VALUES THERE. AS THE FRONT MOVES OFF TO
THE EAST...HIGH PRESSURE WILL BUILD IN FROM THE NORTHWEST SUNDAY AND
REMAIN THROUGH MONDAY. TEMPERATURES WILL REMAIN 3 TO 5 DEGREES BELOW
NORMAL WITH AFTERNOON HIGHS IN THE LOW TO MID 80S DURING THE PERIOD.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
AT KCLT...FAIR WX (VFR CONDITIONS) EXPECTED THRU THE PERIOD WITH A
LIGHT SLY/SWLY WIND. MOISTURE WILL GRADUALLY INCREASE FROM THE WEST
OVERNIGHT THRU TUESDAY MORNING (GENERALLY MID AND UPR LVL).
CONVECTION WILL APPROACH FROM THE WEST AS WELL...BUT NOT EXPECTING
ANY CONVECTION AT KCLT THRU 18Z TUESDAY AT THIS TIME.
ELSEWHERE...FAIR WX CU AND INCREASING MID AND HIGH CLOUDS INTO THIS
EVENING. THE VFR CLOUDS MAY LIMIT ANY FOG/STRATUS DEVELOP...ALTHOUGH
LLVL MOISTURE WILL ALSO INCREASE FROM THE WEST LATE TNGT. LEFT OUT
ANY MENTION OF RESTRICTIONS FOR NOW. CONVECTION WILL ALSO BE
POSSIBLE WITH THIS MOISTURE BY MIDDAY TUESDAY...SO PROB30 ALREADY
ADDED FOR LAST 2-3 HOURS OF TAFS FOR KAVL/KHKY/KAND. LESS CONFIDENT
FOR KGSP/KGMU AT THIS TIME.
OUTLOOK...A SLOW MOVING COLD FRONT IS EXPECTED TO CROSS THE SOUTHERN
APPALACHIAN REGION TUESDAY AFTERNOON THROUGH TUESDAY
NIGHT...BRINGING A CHC FOR SHRA/TSRA. THE CENTER OF SURFACE HIGH
PRESSURE WILL SETTLE OVER THE REGION ON WEDNESDAY AND REMAIN THROUGH
THE WORK WEEK.
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...JOH
NEAR TERM...ARK
SHORT TERM...RWH
LONG TERM...JOH
AVIATION...ARK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
254 PM EDT MON AUG 13 2012
.SYNOPSIS...
A COLD FRONT WILL APPROACH THE AREA FROM THE NORTHWEST TONIGHT AS
HIGH PRESSURE MOVES OFF THE ATLANTIC COAST. THIS FRONT WILL CROSS
OUR REGION LATE TUESDAY FOLLOWED BY HIGH PRESSURE WEDNESDAY AND
THURSDAY. ANOTHER COLD FRONT IS EXPECTED TO CROSS THE AREA LATE IN
THE WEEK.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS OF 145 PM...THE MAIN THING OF CONCERN FOR THIS UPDATE IS A LINE
OF CONVECTION CROSSING CENTRAL TN AND AL ATTM. THE MODELS DO NOT
SEEM TO BE HANDLING THIS VERY WELL. ATTM...IT STILL LOOKED LIKE THE
LINE WILL LOSE STEAM AS IT ENCOUNTERS STABLE AIR OVER ERN TN AND GA.
WITH THAT SAID...THE LATEST RAP BRINGS INSTBY WITH THE LINE (AS IT
IS NOT MOVING VERY FAST)...SUCH THAT THE SW NC MTNS DO DEVELOP ABOUT
1000-1500 J/KG OF CAPE BY 23Z AS THE LINE ARRIVES. THE CONVECTION
WILL HAVE THE ASSOCIATED MCV TO HELP WITH FORCING AS WELL. SO
ANOTHER UPDATE MAY BE NEEDED SHORTLY TO BUMP UP POP THERE. FOR
SURE...THE MOISTURE WILL SPREAD IN THIS EVENING/OVERNIGHT BRINGING
MAINLY MID AND HIGH CLOUDS. SOME SHWRS MAY SURVIVE INTO THE NC MTNS
THRU DAYBREAK. TEMPS ARE STILL FCST TO DROP TO NORMAL OR EVEN A
CATEGORY BELOW (THO THOSE MAY BE TOO COOL GIVEN EXPECTED CLOUD
COVER).
TUESDAY...A SHORTWAVE TROF WILL ROUND THE BASE OF THE LONGWAVE TROF
AXIS INVOF THE OH/TN VLYS. MEANWHILE...AN ASSOCIATED SFC LOW WILL
TRACK FROM THE MID MS VLY TO AROUND LAKE ERIE BY TUESDAY EVENING.
THE LOW PRES SYSTEM WILL PUSH A COLD FRONT ACRS THE OH/TN VLYS ON
TUESDAY...WITH PRE-FRONTAL BAND OF MOISTURE CROSSING THE CWFA.
GUIDANCE IN GOOD AGREEMENT OF HIGH-END CHC POPS FOR MOST OF THE AREA
WITH DECENT INSTBY AND NOMINAL BULK SHEAR. LLVL CONVERGENCE AND UPR
SUPPORT DO NOT LOOK THAT IMPRESSIVE. SO NOT EXPECTING TOO MUCH
ORGANIZATION. HOWEVER...A FEW SEVERE STORM CLUSTERS WILL BE POSSIBLE
TUESDAY AFTN. TEMPS WILL BE ONE TO TWO CATEGORIES BELOW NORMAL UNDER
MOSTLY CLOUDY SKIES.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
AS OF 245 PM MONDAY...A SHORT WAVE SWINGS ACROSS THE AREA TUE NITE
THEN EAST ON WED...LEAVING NEARLY ZONAL FLOW IN ITS WAKE FOR THU. AT
THE SFC...A COLD FRONT MOVES THRU WITH THE WAVE TUE NITE THEN EAST
OF THE AREA WED AS WELL. HIGH PRESSURE BUILDS IN FOR THU. EXPECT SCT
CONVECTION TO BE ONGOING TUE EVENING WHICH THEN DISSIPATES OVERNIGHT
WITH LOSS OF INSTABILITY. HOWEVER...ISOLATED SHRA COULD LINGER OVER
THE EAST NEAR THE FRONT AND OVER THE MTNS IN THE DEVELOPING WLY FLOW
AND LINGERING LOW LEVEL MOISTURE. ATMOS BECOMES CAPPED WED WITH
WARMER MID LEVEL TEMPS AND DIMINISHING LOW LEVEL MOISTURE IN THE
DEVELOPING WLY FLOW. TEMPS NEAR NORMAL TUE NITE AND WED. ATMOS
REMAINS CAPPED THU AS RELATIVELY WARM MID LEVEL TEMPS CONTINUE. LOW
LEVEL MOISTURE WILL BE LIMITED AS WELL. HOWEVER...ENUF H85 MOISTURE
WILL BE AROUND FOR A DECENT CU FIELD TO DEVELOP DURING THE
AFTERNOON. THEREFORE...HAVE A CONTINUED DRY FCST WITH LOWS FALLING A
LITTLE BELOW NORMAL BUT HIGHS REMAINING NEARLY STEADY AROUND NORMAL.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 230 PM EDT MONDAY...THE LATEST MEDIUM RANGE MODELS INDICATE
THAT A WEAK RIDGE OF HIGH OVER OUR AREA MOVES OFF TO THE EAST ON
LATE THURSDAY AS A COLD FRONT AND ASSOCIATED UPPER TROUGH OVER THE
GREAT LAKES REGION DIGS SOUTH INTO TN/OH. THE FRONT IS EXPECTED TO
SLIP FURTHER SOUTH INTO THE APPALACHIANS BY FRIDAY AND CROSSES OUR
CWA ON SATURDAY. WITH DEEPENING MOISTURE...MODERATE INSTABILITY
AND UPPER LEVEL DIVERGENCE...WILL INCREASE POPS INO THE 30-40
PERCENT RANGE FRI/SAT. SOME THUNDERSTORMS COULD BE SEVERE ON
SATURDAY MAINLY OVER THE BLUE RIDGE AND NORTH CAROLINA PIEDMONT AS
MODEL SOUNDINGS SHOW FAIRLY STRONG 0-6KM BULK WIND SHEAR MAGNITUDE
OF +30KT AND MODERATE CAPE VALUES THERE. AS THE FRONT MOVES OFF TO
THE EAST...HIGH PRESSURE WILL BUILD IN FROM THE NORTHWEST SUNDAY AND
REMAIN THROUGH MONDAY. TEMPERATURES WILL REMAIN 5 TO 10 DEGREES
BELOW NORMALS WITH HIGHS IN THE LOW TO MID 80S SATURDAY THROUGH
MONDAY.
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
AT KCLT...FAIR WX (VFR CONDITIONS) EXPECTED THRU THE PERIOD WITH A
LIGHT SLY/SWLY WIND. MOISTURE WILL GRADUALLY INCREASE FROM THE WEST
OVERNIGHT THRU TUESDAY MORNING (GENERALLY MID AND UPR LVL).
CONVECTION WILL APPROACH FROM THE WEST AS WELL...BUT NOT EXPECTING
ANY CONVECTION AT KCLT THRU 18Z TUESDAY AT THIS TIME.
ELSEWHERE...FAIR WX CU AND INCREASING MID AND HIGH CLOUDS INTO THIS
EVENING. THE VFR CLOUDS MAY LIMIT ANY FOG/STRATUS DEVELOP...ALTHOUGH
LLVL MOISTURE WILL ALSO INCREASE FROM THE WEST LATE TNGT. LEFT OUT
ANY MENTION OF RESTRICTIONS FOR NOW. CONVECTION WILL ALSO BE
POSSIBLE WITH THIS MOISTURE BY MIDDAY TUESDAY...SO PROB30 ALREADY
ADDED FOR LAST 2-3 HOURS OF TAFS FOR KAVL/KHKY/KAND. LESS CONFIDENT
FOR KGSP/KGMU AT THIS TIME.
OUTLOOK...A SLOW MOVING COLD FRONT IS EXPECTED TO CROSS THE SOUTHERN
APPALACHIAN REGION TUESDAY AFTERNOON THROUGH TUESDAY
NIGHT...BRINGING A CHC FOR SHRA/TSRA. THE CENTER OF SURFACE HIGH
PRESSURE WILL SETTLE OVER THE REGION ON WEDNESDAY AND REMAIN THROUGH
THE WORK WEEK.
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...JOH
NEAR TERM...ARK
SHORT TERM...RWH
LONG TERM...JOH
AVIATION...ARK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
206 PM EDT MON AUG 13 2012
.SYNOPSIS...
A COLD FRONT WILL APPROACH THE AREA FROM THE NORTHWEST TONIGHT AS
HIGH PRESSURE MOVES OFF THE ATLANTIC COAST. THIS FRONT WILL CROSS
OUR REGION LATE TUESDAY FOLLOWED BY HIGH PRESSURE WEDNESDAY AND
THURSDAY. ANOTHER COLD FRONT IS EXPECTED TO CROSS THE AREA LATE IN
THE WEEK.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS OF 145 PM...THE MAIN THING OF CONCERN FOR THIS UPDATE IS A LINE
OF CONVECTION CROSSING CENTRAL TN AND AL ATTM. THE MODELS DO NOT
SEEM TO BE HANDLING THIS VERY WELL. ATTM...IT STILL LOOKED LIKE THE
LINE WILL LOSE STEAM AS IT ENCOUNTERS STABLE AIR OVER ERN TN AND GA.
WITH THAT SAID...THE LATEST RAP BRINGS INSTBY WITH THE LINE (AS IT
IS NOT MOVING VERY FAST)...SUCH THAT THE SW NC MTNS DO DEVELOP ABOUT
1000-1500 J/KG OF CAPE BY 23Z AS THE LINE ARRIVES. THE CONVECTION
WILL HAVE THE ASSOCIATED MCV TO HELP WITH FORCING AS WELL. SO
ANOTHER UPDATE MAY BE NEEDED SHORTLY TO BUMP UP POP THERE. FOR
SURE...THE MOISTURE WILL SPREAD IN THIS EVENING/OVERNIGHT BRINGING
MAINLY MID AND HIGH CLOUDS. SOME SHWRS MAY SURVIVE INTO THE NC MTNS
THRU DAYBREAK. TEMPS ARE STILL FCST TO DROP TO NORMAL OR EVEN A
CATEGORY BELOW (THO THOSE MAY BE TOO COOL GIVEN EXPECTED CLOUD
COVER).
TUESDAY...A SHORTWAVE TROF WILL ROUND THE BASE OF THE LONGWAVE TROF
AXIS INVOF THE OH/TN VLYS. MEANWHILE...AN ASSOCIATED SFC LOW WILL
TRACK FROM THE MID MS VLY TO AROUND LAKE ERIE BY TUESDAY EVENING.
THE LOW PRES SYSTEM WILL PUSH A COLD FRONT ACRS THE OH/TN VLYS ON
TUESDAY...WITH PRE-FRONTAL BAND OF MOISTURE CROSSING THE CWFA.
GUIDANCE IN GOOD AGREEMENT OF HIGH-END CHC POPS FOR MOST OF THE AREA
WITH DECENT INSTBY AND NOMINAL BULK SHEAR. LLVL CONVERGENCE AND UPR
SUPPORT DO NOT LOOK THAT IMPRESSIVE. SO NOT EXPECTING TOO MUCH
ORGANIZATION. HOWEVER...A FEW SEVERE STORM CLUSTERS WILL BE POSSIBLE
TUESDAY AFTN. TEMPS WILL BE ONE TO TWO CATEGORIES BELOW NORMAL UNDER
MOSTLY CLOUDY SKIES.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AT 315 AM EDT MONDAY...UPPER LEVEL HEIGHTS WILL FALL THROUGHOUT THE
DAY TUE AHEAD OF A WEAKLY FORCED COLD FRONT. THE BEST MID TO UPPER
LEVEL DPVA WILL BE WELL NORTH OF THE AREA AND THE BEST THERMAL
FORCING TO THE SOUTH. THE SOUNDINGS DO DEPICT A DEEP LAYER OF
UNSTABLE AREA....BUT THE DEGREE OF UPWARD ACCELERATION WILL BE ON
THE LOW SIDE DUE TO A RELATIVELY WARM MID/UPPER LAYER. THE BEST LLVL
MOISTURE WILL BE ASSOCIATED WITH THE FRONTAL CONVERGENCE ZONE AS IT
CROSSES THE MTNS AND THEREFORE THE BEST CHANCE POPS WILL BE
MAINTAINED THERE...GENERALLY SCATTERED DIURNAL STORM COVERAGE. SOME
OF THESE STORMS COULD BECOME FAIRLY STRONG TO SEVERE HOWEVER...WITH
DAMAGING DOWNBURSTS BEING THE MAIN THREAT. THE TROF AXIS TRANSITIONS
EAST OF THE AREA EARLY WED...BUT IT WILL HAVE VERY LIMITED MOISTURE
TO WORK WITH AS A SFC LAYERED ANTICYCLONE BUILDS IN AND DRIES UP THE
COLUMN...RAISING LCLS TO AROUND 7 KFT WITH AN ASSOCIATED SHALLOW
MOIST LAYER. POPS FOR THU WILL REMAIN LOW AND NO GOOD CHANCE OF
-SHRA/TSTMS WILL BE ADVERTISED. MAX TEMPS WILL BE RIGHT AROUND
NORMAL TUE AND A BIT HIGHER WED WITH THE INCREASING SUBSIDENCE.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AT 130 AM EDT MONDAY...A SMALL SCALE UPPER RIDGE CONTIUNES MOVING
EAST OF THE AREA THU AND THIS WILL KEEP THINGS MOSTLY DRY AND ABOVE
NORMAL TEMPERTURE/WISE. ISOL LATE AFTERNOON MTN SHOWERS AND A COUPLE
TSTMS ARE PROBABLE...BUT AM NOT EXPECTING LONG LIVED OR VERY STRONG
CONVECTION AS THE ACTIVITY WILL BE MAINLY DIURNALLY FORCED. AS H5
HEIGHTS LOWER FRI...A PRE/FROTNAL TROF PUSHES INTO THE CWFA AND WILL
INSTIGATE AFTERNOON -SHRA/TSTMS ONCE AGAIN...YET MORE WIDESPREAD AND
EAST THAN ON THU. MODELS ARE VERY STINGY WITH LLVL AND ELEVATED
INSTABILITY LEVELS WHILE A BROAD HEIGHT FIELD PRODUCES LITTLE DEEP
LAYERD SHEAR. SO...THE CHANCE FOR A SIGFNT STRONG/SEVERE THREAT
SHOULD BE RATHER LIMITED. FROPA IS EXPECTED FRI NIGHT AND MILD
AIRMASS MIX WILL HELP KEEP SFC BASED INSTABILITY LOW SAT. THE 00Z
GFS IS BRINGING IN TOO MUCH STREAMLINED VORT DUE TO CONV FEEDBACK
OVER THE SRN PLAINS...SO IT/S SOLN OF WIDEPREAD PRECIP AND
CONVECTIVE ACTIVITY WAS GIVEN LITTLE WEIGHT FOR POPS AND SENSIBLE
WEATHER SAT AFTERNOON AND SIDED MORESO WITH THE ECMWF. THUS...EXPECT
A MAINLY DRY WEEKEND WITH RATHER NICE TEMPS AROUND OR A LITTLE BELOW
SEASONAL LEVELS.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AT KCLT...FAIR WX (VFR CONDITIONS) EXPECTED THRU THE PERIOD WITH A
LIGHT SLY/SWLY WIND. MOISTURE WILL GRADUALLY INCREASE FROM THE WEST
OVERNIGHT THRU TUESDAY MORNING (GENERALLY MID AND UPR LVL).
CONVECTION WILL APPROACH FROM THE WEST AS WELL...BUT NOT EXPECTING
ANY CONVECTION AT KCLT THRU 18Z TUESDAY AT THIS TIME.
ELSEWHERE...FAIR WX CU AND INCREASING MID AND HIGH CLOUDS INTO THIS
EVENING. THE VFR CLOUDS MAY LIMIT ANY FOG/STRATUS DEVELOP...ALTHOUGH
LLVL MOISTURE WILL ALSO INCREASE FROM THE WEST LATE TNGT. LEFT OUT
ANY MENTION OF RESTRICTIONS FOR NOW. CONVECTION WILL ALSO BE
POSSIBLE WITH THIS MOISTURE BY MIDDAY TUESDAY...SO PROB30 ALREADY
ADDED FOR LAST 2-3 HOURS OF TAFS FOR KAVL/KHKY/KAND. LESS CONFIDENT
FOR KGSP/KGMU AT THIS TIME.
OUTLOOK...A SLOW MOVING COLD FRONT IS EXPECTED TO CROSS THE SOUTHERN
APPALACHIAN REGION TUESDAY AFTERNOON THROUGH TUESDAY
NIGHT...BRINGING A CHC FOR SHRA/TSRA. THE CENTER OF SURFACE HIGH
PRESSURE WILL SETTLE OVER THE REGION ON WEDNESDAY AND REMAIN THROUGH
THE WORK WEEK.
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...SBK
NEAR TERM...ARK
SHORT TERM...SBK
LONG TERM...SBK
AVIATION...ARK
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1054 PM CDT TUE AUG 14 2012
.DISCUSSION.../ISSUED AT 950 PM CDT/
FORECAST LOOKS IN GOOD SHAPE FOR THE OVERNIGHT HOURS. THETAE
ADVECTION ASSOCIATED WITH THE LOW LEVEL JET APPEARS TO FOCUS ACROSS
SOUTHWEST MINNESOTA LATER THIS EVENING INTO REST OF THE NIGHT. LAPSE
RATES NOT TOO IMPRESSIVE...BUT COULD SEE SOME WEAK ELEVATED
INSTABILITY DEVELOP. THUS KEPT IN THE CHANCE OF SHOWERS...AND MAYBE
AN ISOLATED THUNDERSTORM...ACROSS MAINLY OUR MINNESOTA COUNTIES.
OTHERWISE IT LOOKS TO REMAIN PARTLY CLOUDY OVER THE REST OF THE
AREA. A LIGHT SOUTHERLY BREEZE AND CLOUD COVER SHOULD HELP KEEP
TEMPERATURES IN THE LOW TO MID 60S. EXPECT ANY SCATTERED SHOWER
ACTIVITY TO BE OUT OF THE CWA BY AROUND 12Z. /CHENARD
&&
.AVIATION.../FOR THE 06Z TAF ISSUANCE/
VFR CONDITIONS EXPECTED THROUGH THE REST OF TONIGHT AND WEDNESDAY.
THE MOST SIGNIFICANT FEATURE IS A STRONG COLD FRONT MOVING THROUGH
OUR FORECAST AREA WEDNESDAY AFTERNOON AND EVENING. AN ABRUPT WIND
SHIFT TO THE NORTHWEST AND NORTH WILL FOLLOW THE FRONT...AND WIND
SPEEDS WILL BECOME QUITE STRONG APPROACHING CENTRAL SOUTH DAKOTA BY
AFTERNOON WITH FREQUENT GUSTS OVER 30 KNOTS. ALONG THE FRONT...THE
BEST CHANCE FOR STRONG THUNDERSTORMS WILL OCCUR WEDNESDAY EVENING
GENERALLY ALONG AND SOUTH OF A SIOUX CITY TO SPENCER IOWA LINE.
THERE ARE ALSO POST FRONTAL SHOWERS AND THUNDERSTORMS POSSIBLE ALL
EVENING LONG...ALONG AND EAST OF A TYNDALL SOUTH DAKOTA TO DE SMET
SOUTH DAKOTA LINE.
&&
.PREVIOUS DISCUSSION.../ISSUED AT 339 PM CDT/
COMPLEX WEAK TROUGH WORKING ACROSS THE EASTERN DAKOTAS THIS
AFTERNOON. ONE CORE DIGGING SOUTHWARD THROUGH EASTERN
NEBRASKA...WITH COOL AIR POOL LEFTOVER AROUND THE KYKN AREA FROM
EARLIER SHOWERS/THUNDERSTORMS TO THE SOUTH. CAN SEE A SECONDARY
IMPULSE DROPPING SOUTHEAST FROM SOUTHERN NORTH DAKOTA TOWARD
SOUTHWEST MINNESOTA. SUBTLE BOUNDARY ON RADAR NORTH OF KFSD...AND
BEST LOWER TO MID LEVEL BOUNDARY WILL REMAIN JUST NORTH AND EAST OF
THE AREA THROUGH THE EVENING HOURS BEFORE STARTING TO NUDGE
NORTHEAST. ELEVATED THETA E ADVECTION FOCUSES THROUGH THE NORTHEAST
HALF OF THE AREA OVERNIGHT...AND CONCENTRATION TO POPS MADE THROUGH
THAT AREA... WINDING DOWN LATER IN THE NIGHT. HRRR HAS SOME SUPPORT
TO DEVELOPMENT DURING THE EVENING IN THIS AREA...KICKING UP AS THE
LOW LEVEL JET STARTS TO INCREASE AROUND SUNSET.
ON WEDNESDAY...MUCH OF THE DAY LOOKS TO BE INERT WEATHERWISE...
WITH VERY WARM 700 HPA TEMPERATURES AND SURFACE FRONT APPROACHING
FROM THE WEST. 3 HOUR PRESSURE RISES OF 5-6 HPA/3H WILL PRESS IN
BEHIND BOUNDARY...WITH MIXED LAYER WINDS TOPPING OUT 30-35 KNOTS.
HAVE ISSUED A WIND ADVISORY FOR THE FAR SOUTHWEST AREAS...WITH A
POTENTIAL THAT MAY NEED A SLIGHT EASTWARD EXPANSION TOWARD THE JAMES
VALLEY.
HARD TO PICTURE SURFACE BOUNDARY GOING CONVECTIVE WITH A MID
AFTERNOON INHIBITION OF 200-300 J/KG...SO MAY END UP GOING A BIT
BEHIND BOUNDARY INITIALLY...SO HEDGED POPS A BIT FURTHER BACK
WESTWARD FROM EXPECTED BOUNDARY LOCATION...WHICH SHOULD BE NEAR A
KOTG TO KLCG LINE BY 00Z. DEEP LAYER SHEAR AROUND 40 KNOTS WILL
SUGGEST A GOOD POTENTIAL FOR ORGANIZATION AND DISCRETE STRUCTURES
INITIALLY WITH CROSS BOUNDARY SHEAR. ONE PROBLEM WILL BE THE
AVAILABLE MOISTURE...AS DO EXPECT THAT PREFRONTAL AREAS WILL MIX
VERY WELL...WELL INTO THE 90S TEMPWISE...WITH DEWPOINTS PERHAPS INTO
THE LOWER 50S. CAPE WILL PROBABLY BE LIMITED TO 1000-1500 J/KG.
SHOULD BE ENOUGH FOR A HAIL/WIND THREAT FOR THE VERY LATE AFTERNOON.
/CHAPMAN
WEDNESDAY NIGHT WILL SEE THE CONVECTION ALONG THE FRONT RACE QUICKLY
EAST OUT OF THE CWA...WILL HAVE SOME LOWER POPS IN THE FAR EASTERN
PART OF THE CWA THROUGH ABOUT 9Z IN CASE BOUNDARY IS A LITTLE SLOWER
BUT OVERALL MOST ACTIVITY LIKELY TO BE FROM ABOUT 23Z THROUGH 4Z AND
MAINLY IN SOUTHWEST MINNESOTA AND NORTHWEST IOWA. WILL MAINTAIN A
THREAT FOR SEVERE WEATHER THROUGH THIS TIME AS THE DEEPER BULK SHEAR
VALUES INCREASE TO ABOUT 40 KNOTS WITH FAIRLY STRONG CAPE VALUES.
COOLER AND DRIER AIR WILL PUSH IN BEHIND THE FRONT WITH BREEZY
EVENING CONDITIONS LEADING INTO A BIT OF A BREEZY AND COOL THURSDAY.
LOWS IN THE MID 50S WITH 10 TO 15 MPH WIND WILL LEAD TOWARDS HIGHS
THURSDAY FROM THE UPPER 60S IN SOUTHWEST MINNESOTA TO THE MID 70S IN
SOUTH CENTRAL SOUTH DAKOTA. EXPECTING A BIT OF CLOUD COVER TO LINGER
OVER THE SOOTH AND EAST PARTS OF THE CWA AS THE WAVE ROTATES
EASTWARD WHICH WILL AID IN LIMITING THE HIGH TEMPERATURE POTENTIAL.
FRIDAY MORNING PUTS THE AREA IN THE HEART OF THE COOLER AIR AS HIGH
PRESSURE SHOULD BE NEAR THE BIG SIOUX RIVER VALLEY AROUND 12Z
FRIDAY. UTILITY OF THE LOCAL EXTREME CLIMATOLOGY FITS WELL FOR
RECORD TO NEAR RECORD MORNING LOWS SO WILL AIM A LITTLE BELOW THE
COLDEST GUIDANCE WITH MOST AREAS DROPPING DOWN INTO THE LOWER TO
MIDDLE 40S.
FRIDAY WILL BE A FAIRLY COOL BUT VERY PLEASANT DAY WITH DRY AIR IN
PLACE...HIGH PRESSURE ONLY GRADUALLY SHIFTING SOUTHEAST AND 925MB
TEMPERATURES IN THE MID TO UPPER TEENS. THIS SHOULD BRING A MOSTLY
SUNNY DAY WITH HIGHS FROM THE LOWER TO MIDDLE 70S.
IN THE LATTER PERIODS(SAT/TUE)...MODELS FAIRLY AGREEABLE UPON
DEVELOPING A LARGE SCALE HUDSON BAY LOW...WITH RIDGING OVER THE
WESTERN UNITED STATES. THIS SUGGESTS NORMAL TO BELOW NORMAL
CONDITIONS WITH ONLY SPOTTY CHANCES FOR RAIN AND THUNDERSTORMS. THE
GFS IS THE MOST AGGRESSIVE AT DEVELOPING THIS LOW WHILE THE ECMWF
AND CANADIAN SUGGEST THAT A SHORTWAVE WILL ROUND THE RIDGE IN THE
WEST LATE IN THE PERIOD AND HELP EJECT THE HUDSON BAY LOW EASTWARD.
NOT BUYING INTO THIS SCENARIO COMPLETELY AS THIS WAVE COULD JUST
ROUND THE WESTERN SIDE OF THE HUDSON BAY LOW...FURTHER DEEPENING IT.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...WIND ADVISORY 18Z WED THROUGH 00Z WED FOR SDZ050-057-063.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
950 PM CDT TUE AUG 14 2012
.DISCUSSION.../ISSUED AT 950 PM CDT/
FORECAST LOOKS IN GOOD SHAPE FOR THE OVERNIGHT HOURS. THETAE
ADVECTION ASSOCIATED WITH THE LOW LEVEL JET APPEARS TO FOCUS ACROSS
SOUTHWEST MINNESOTA LATER THIS EVENING INTO REST OF THE NIGHT. LAPSE
RATES NOT TOO IMPRESSIVE...BUT COULD SEE SOME WEAK ELEVATED
INSTABILITY DEVELOP. THUS KEPT IN THE CHANCE OF SHOWERS...AND MAYBE
AN ISOLATED THUNDERSTORM...ACROSS MAINLY OUR MINNESOTA COUNTIES.
OTHERWISE IT LOOKS TO REMAIN PARTLY CLOUDY OVER THE REST OF THE
AREA. A LIGHT SOUTHERLY BREEZE AND CLOUD COVER SHOULD HELP KEEP
TEMPERATURES IN THE LOW TO MID 60S. EXPECT ANY SCATTERED SHOWER
ACTIVITY TO BE OUT OF THE CWA BY AROUND 12Z. /CHENARD
&&
.AVIATION.../FOR THE 00Z TAF ISSUANCE/
VFR CONDITIONS EXPECTED THROUGH THE REST OF TONIGHT AND WEDNESDAY.
THE MOST SIGNIFICANT FEATURE IS A STRONG COLD FRONT MOVING THROUGH
OUR SOUTH DAKOTA ZONES AND PART OF OUR MINNESOTA ZONES WEDNESDAY
AFTERNOON. WINDS WILL BECOME NORTHWEST AND STRONG BEHIND THE FRONT
APPROACHING OUR CENTRAL SOUTH DAKOTA COUNTIES...WITH FREQUENT GUSTS
OVER 30 KNOTS IN THOSE AREAS BY WEDNESDAY AFTERNOON. OTHERWISE...
THUNDERSTORM COVERAGE WILL BE SPOTTY WEDNESDAY AFTERNOON AND NOT
INCLUDED IN ANY TAF SITE AT THIS TIME. BETTER COVERAGE OF
THUNDERSTORMS IS ANTICIPATED IN SOUTHWEST MN...EXTREME SOUTHEAST SD
AND NORTHWEST IA BUT NOT UNTIL SHORTLY AFTER 00Z THURSDAY.
&&
.PREVIOUS DISCUSSION.../ISSUED AT 339 PM CDT/
COMPLEX WEAK TROUGH WORKING ACROSS THE EASTERN DAKOTAS THIS
AFTERNOON. ONE CORE DIGGING SOUTHWARD THROUGH EASTERN
NEBRASKA...WITH COOL AIR POOL LEFTOVER AROUND THE KYKN AREA FROM
EARLIER SHOWERS/THUNDERSTORMS TO THE SOUTH. CAN SEE A SECONDARY
IMPULSE DROPPING SOUTHEAST FROM SOUTHERN NORTH DAKOTA TOWARD
SOUTHWEST MINNESOTA. SUBTLE BOUNDARY ON RADAR NORTH OF KFSD...AND
BEST LOWER TO MID LEVEL BOUNDARY WILL REMAIN JUST NORTH AND EAST OF
THE AREA THROUGH THE EVENING HOURS BEFORE STARTING TO NUDGE
NORTHEAST. ELEVATED THETA E ADVECTION FOCUSES THROUGH THE NORTHEAST
HALF OF THE AREA OVERNIGHT...AND CONCENTRATION TO POPS MADE THROUGH
THAT AREA... WINDING DOWN LATER IN THE NIGHT. HRRR HAS SOME SUPPORT
TO DEVELOPMENT DURING THE EVENING IN THIS AREA...KICKING UP AS THE
LOW LEVEL JET STARTS TO INCREASE AROUND SUNSET.
ON WEDNESDAY...MUCH OF THE DAY LOOKS TO BE INERT WEATHERWISE...
WITH VERY WARM 700 HPA TEMPERATURES AND SURFACE FRONT APPROACHING
FROM THE WEST. 3 HOUR PRESSURE RISES OF 5-6 HPA/3H WILL PRESS IN
BEHIND BOUNDARY...WITH MIXED LAYER WINDS TOPPING OUT 30-35 KNOTS.
HAVE ISSUED A WIND ADVISORY FOR THE FAR SOUTHWEST AREAS...WITH A
POTENTIAL THAT MAY NEED A SLIGHT EASTWARD EXPANSION TOWARD THE JAMES
VALLEY.
HARD TO PICTURE SURFACE BOUNDARY GOING CONVECTIVE WITH A MID
AFTERNOON INHIBITION OF 200-300 J/KG...SO MAY END UP GOING A BIT
BEHIND BOUNDARY INITIALLY...SO HEDGED POPS A BIT FURTHER BACK
WESTWARD FROM EXPECTED BOUNDARY LOCATION...WHICH SHOULD BE NEAR A
KOTG TO KLCG LINE BY 00Z. DEEP LAYER SHEAR AROUND 40 KNOTS WILL
SUGGEST A GOOD POTENTIAL FOR ORGANIZATION AND DISCRETE STRUCTURES
INITIALLY WITH CROSS BOUNDARY SHEAR. ONE PROBLEM WILL BE THE
AVAILABLE MOISTURE...AS DO EXPECT THAT PREFRONTAL AREAS WILL MIX
VERY WELL...WELL INTO THE 90S TEMPWISE...WITH DEWPOINTS PERHAPS INTO
THE LOWER 50S. CAPE WILL PROBABLY BE LIMITED TO 1000-1500 J/KG.
SHOULD BE ENOUGH FOR A HAIL/WIND THREAT FOR THE VERY LATE AFTERNOON.
/CHAPMAN
WEDNESDAY NIGHT WILL SEE THE CONVECTION ALONG THE FRONT RACE QUICKLY
EAST OUT OF THE CWA...WILL HAVE SOME LOWER POPS IN THE FAR EASTERN
PART OF THE CWA THROUGH ABOUT 9Z IN CASE BOUNDARY IS A LITTLE SLOWER
BUT OVERALL MOST ACTIVITY LIKELY TO BE FROM ABOUT 23Z THROUGH 4Z AND
MAINLY IN SOUTHWEST MINNESOTA AND NORTHWEST IOWA. WILL MAINTAIN A
THREAT FOR SEVERE WEATHER THROUGH THIS TIME AS THE DEEPER BULK SHEAR
VALUES INCREASE TO ABOUT 40 KNOTS WITH FAIRLY STRONG CAPE VALUES.
COOLER AND DRIER AIR WILL PUSH IN BEHIND THE FRONT WITH BREEZY
EVENING CONDITIONS LEADING INTO A BIT OF A BREEZY AND COOL THURSDAY.
LOWS IN THE MID 50S WITH 10 TO 15 MPH WIND WILL LEAD TOWARDS HIGHS
THURSDAY FROM THE UPPER 60S IN SOUTHWEST MINNESOTA TO THE MID 70S IN
SOUTH CENTRAL SOUTH DAKOTA. EXPECTING A BIT OF CLOUD COVER TO LINGER
OVER THE SOOTH AND EAST PARTS OF THE CWA AS THE WAVE ROTATES
EASTWARD WHICH WILL AID IN LIMITING THE HIGH TEMPERATURE POTENTIAL.
FRIDAY MORNING PUTS THE AREA IN THE HEART OF THE COOLER AIR AS HIGH
PRESSURE SHOULD BE NEAR THE BIG SIOUX RIVER VALLEY AROUND 12Z
FRIDAY. UTILITY OF THE LOCAL EXTREME CLIMATOLOGY FITS WELL FOR
RECORD TO NEAR RECORD MORNING LOWS SO WILL AIM A LITTLE BELOW THE
COLDEST GUIDANCE WITH MOST AREAS DROPPING DOWN INTO THE LOWER TO
MIDDLE 40S.
FRIDAY WILL BE A FAIRLY COOL BUT VERY PLEASANT DAY WITH DRY AIR IN
PLACE...HIGH PRESSURE ONLY GRADUALLY SHIFTING SOUTHEAST AND 925MB
TEMPERATURES IN THE MID TO UPPER TEENS. THIS SHOULD BRING A MOSTLY
SUNNY DAY WITH HIGHS FROM THE LOWER TO MIDDLE 70S.
IN THE LATTER PERIODS(SAT/TUE)...MODELS FAIRLY AGREEABLE UPON
DEVELOPING A LARGE SCALE HUDSON BAY LOW...WITH RIDGING OVER THE
WESTERN UNITED STATES. THIS SUGGESTS NORMAL TO BELOW NORMAL
CONDITIONS WITH ONLY SPOTTY CHANCES FOR RAIN AND THUNDERSTORMS. THE
GFS IS THE MOST AGGRESSIVE AT DEVELOPING THIS LOW WHILE THE ECMWF
AND CANADIAN SUGGEST THAT A SHORTWAVE WILL ROUND THE RIDGE IN THE
WEST LATE IN THE PERIOD AND HELP EJECT THE HUDSON BAY LOW EASTWARD.
NOT BUYING INTO THIS SCENARIO COMPLETELY AS THIS WAVE COULD JUST
ROUND THE WESTERN SIDE OF THE HUDSON BAY LOW...FURTHER DEEPENING IT.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...WIND ADVISORY 18Z WED THROUGH 00Z WED FOR SDZ050-057-063.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
707 PM CDT TUE AUG 14 2012
.DISCUSSION.../ISSUED AT 339 PM CDT/
COMPLEX WEAK TROUGH WORKING ACROSS THE EASTERN DAKOTAS THIS
AFTERNOON. ONE CORE DIGGING SOUTHWARD THROUGH EASTERN
NEBRASKA...WITH COOL AIR POOL LEFTOVER AROUND THE KYKN AREA FROM
EARLIER SHOWERS/THUNDERSTORMS TO THE SOUTH. CAN SEE A SECONDARY
IMPULSE DROPPING SOUTHEAST FROM SOUTHERN NORTH DAKOTA TOWARD
SOUTHWEST MINNESOTA. SUBTLE BOUNDARY ON RADAR NORTH OF KFSD...AND
BEST LOWER TO MID LEVEL BOUNDARY WILL REMAIN JUST NORTH AND EAST OF
THE AREA THROUGH THE EVENING HOURS BEFORE STARTING TO NUDGE
NORTHEAST. ELEVATED THETA E ADVECTION FOCUSES THROUGH THE NORTHEAST
HALF OF THE AREA OVERNIGHT...AND CONCENTRATION TO POPS MADE THROUGH
THAT AREA... WINDING DOWN LATER IN THE NIGHT. HRRR HAS SOME SUPPORT
TO DEVELOPMENT DURING THE EVENING IN THIS AREA...KICKING UP AS THE
LOW LEVEL JET STARTS TO INCREASE AROUND SUNSET.
ON WEDNESDAY...MUCH OF THE DAY LOOKS TO BE INERT WEATHERWISE...
WITH VERY WARM 700 HPA TEMPERATURES AND SURFACE FRONT APPROACHING
FROM THE WEST. 3 HOUR PRESSURE RISES OF 5-6 HPA/3H WILL PRESS IN
BEHIND BOUNDARY...WITH MIXED LAYER WINDS TOPPING OUT 30-35 KNOTS.
HAVE ISSUED A WIND ADVISORY FOR THE FAR SOUTHWEST AREAS...WITH A
POTENTIAL THAT MAY NEED A SLIGHT EASTWARD EXPANSION TOWARD THE JAMES
VALLEY.
HARD TO PICTURE SURFACE BOUNDARY GOING CONVECTIVE WITH A MID
AFTERNOON INHIBITION OF 200-300 J/KG...SO MAY END UP GOING A BIT
BEHIND BOUNDARY INITIALLY...SO HEDGED POPS A BIT FURTHER BACK
WESTWARD FROM EXPECTED BOUNDARY LOCATION...WHICH SHOULD BE NEAR A
KOTG TO KLCG LINE BY 00Z. DEEP LAYER SHEAR AROUND 40 KNOTS WILL
SUGGEST A GOOD POTENTIAL FOR ORGANIZATION AND DISCRETE STRUCTURES
INITIALLY WITH CROSS BOUNDARY SHEAR. ONE PROBLEM WILL BE THE
AVAILABLE MOISTURE...AS DO EXPECT THAT PREFRONTAL AREAS WILL MIX
VERY WELL...WELL INTO THE 90S TEMPWISE...WITH DEWPOINTS PERHAPS INTO
THE LOWER 50S. CAPE WILL PROBABLY BE LIMITED TO 1000-1500 J/KG.
SHOULD BE ENOUGH FOR A HAIL/WIND THREAT FOR THE VERY LATE AFTERNOON.
/CHAPMAN
WEDNESDAY NIGHT WILL SEE THE CONVECTION ALONG THE FRONT RACE QUICKLY
EAST OUT OF THE CWA...WILL HAVE SOME LOWER POPS IN THE FAR EASTERN
PART OF THE CWA THROUGH ABOUT 9Z IN CASE BOUNDARY IS A LITTLE SLOWER
BUT OVERALL MOST ACTIVITY LIKELY TO BE FROM ABOUT 23Z THROUGH 4Z AND
MAINLY IN SOUTHWEST MINNESOTA AND NORTHWEST IOWA. WILL MAINTAIN A
THREAT FOR SEVERE WEATHER THROUGH THIS TIME AS THE DEEPER BULK SHEAR
VALUES INCREASE TO ABOUT 40 KNOTS WITH FAIRLY STRONG CAPE VALUES.
COOLER AND DRIER AIR WILL PUSH IN BEHIND THE FRONT WITH BREEZY
EVENING CONDITIONS LEADING INTO A BIT OF A BREEZY AND COOL THURSDAY.
LOWS IN THE MID 50S WITH 10 TO 15 MPH WIND WILL LEAD TOWARDS HIGHS
THURSDAY FROM THE UPPER 60S IN SOUTHWEST MINNESOTA TO THE MID 70S IN
SOUTH CENTRAL SOUTH DAKOTA. EXPECTING A BIT OF CLOUD COVER TO LINGER
OVER THE SOOTH AND EAST PARTS OF THE CWA AS THE WAVE ROTATES
EASTWARD WHICH WILL AID IN LIMITING THE HIGH TEMPERATURE POTENTIAL.
FRIDAY MORNING PUTS THE AREA IN THE HEART OF THE COOLER AIR AS HIGH
PRESSURE SHOULD BE NEAR THE BIG SIOUX RIVER VALLEY AROUND 12Z
FRIDAY. UTILITY OF THE LOCAL EXTREME CLIMATOLOGY FITS WELL FOR
RECORD TO NEAR RECORD MORNING LOWS SO WILL AIM A LITTLE BELOW THE
COLDEST GUIDANCE WITH MOST AREAS DROPPING DOWN INTO THE LOWER TO
MIDDLE 40S.
FRIDAY WILL BE A FAIRLY COOL BUT VERY PLEASANT DAY WITH DRY AIR IN
PLACE...HIGH PRESSURE ONLY GRADUALLY SHIFTING SOUTHEAST AND 925MB
TEMPERATURES IN THE MID TO UPPER TEENS. THIS SHOULD BRING A MOSTLY
SUNNY DAY WITH HIGHS FROM THE LOWER TO MIDDLE 70S.
IN THE LATTER PERIODS(SAT/TUE)...MODELS FAIRLY AGREEABLE UPON
DEVELOPING A LARGE SCALE HUDSON BAY LOW...WITH RIDGING OVER THE
WESTERN UNITED STATES. THIS SUGGESTS NORMAL TO BELOW NORMAL
CONDITIONS WITH ONLY SPOTTY CHANCES FOR RAIN AND THUNDERSTORMS. THE
GFS IS THE MOST AGGRESSIVE AT DEVELOPING THIS LOW WHILE THE ECMWF
AND CANADIAN SUGGEST THAT A SHORTWAVE WILL ROUND THE RIDGE IN THE
WEST LATE IN THE PERIOD AND HELP EJECT THE HUDSON BAY LOW EASTWARD.
NOT BUYING INTO THIS SCENARIO COMPLETELY AS THIS WAVE COULD JUST
ROUND THE WESTERN SIDE OF THE HUDSON BAY LOW...FURTHER DEEPENING IT.
&&
.AVIATION.../FOR THE 00Z TAF ISSUANCE/
VFR CONDITIONS EXPECTED THROUGH THE REST OF TONIGHT AND WEDNESDAY.
THE MOST SIGNIFICANT FEATURE IS A STRONG COLD FRONT MOVING THROUGH
OUR SOUTH DAKOTA ZONES AND PART OF OUR MINNESOTA ZONES WEDNESDAY
AFTERNOON. WINDS WILL BECOME NORTHWEST AND STRONG BEHIND THE FRONT
APPROACHING OUR CENTRAL SOUTH DAKOTA COUNTIES...WITH FREQUENT GUSTS
OVER 30 KNOTS IN THOSE AREAS BY WEDNESDAY AFTERNOON. OTHERWISE...
THUNDERSTORM COVERAGE WILL BE SPOTTY WEDNESDAY AFTERNOON AND NOT
INCLUDED IN ANY TAF SITE AT THIS TIME. BETTER COVERAGE OF
THUNDERSTORMS IS ANTICIPATED IN SOUTHWEST MN...EXTREME SOUTHEAST SD
AND NORTHWEST IA BUT NOT UNTIL SHORTLY AFTER 00Z THURSDAY.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...WIND ADVISORY 18Z WED THROUGH 00Z WED FOR SDZ050-057-063.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
226 PM CDT MON AUG 13 2012
.DISCUSSION...
MORNING CONVECTION HAS MOVED EAST OF THE MIDSOUTH AS EXPECTED WITH
PARTIAL SUNSHINE SPREADING OVER THE AREA FROM THE WEST.
MEANWHILE...A COLD FRONT IS PUSHING INTO NORTHEAST ARKANSAS AND
STRETCHES SOUTHWESTWARD INTO NORTHEAST TX. THE FRONT HAS MOVED
THROUGH WALNUT RIDGE ARKANSAS AND IS APPROACHING JONESBORO.
STILL THINK THERE IS A CHANCE OF SEVERE THUNDERSTORMS LATER THIS
AFTERNOON INTO THIS EVENING ALONG AND AHEAD OF THE COLD
FRONT...ALTHOUGH THE SITUATION IS NOT CLEAR CUT. WATER VAPOR IMAGERY
INDICATES THE MAIN UPPER LEVEL TROUGH IS MOVING EAST OF THE MIDSOUTH
WITH UPPER LEVEL SUPPORT NOW LIMITED ACROSS OUR FORECAST AREA. WATER
VAPOR IMAGERY IS ALSO SHOWING VERY DRY AIR ALOFT MOVING INTO OUR
FORECAST AREA. HOWEVER...VERY WARM AND UNSTABLE AIR IS PUSHING INTO
THE AREA AHEAD OF THE FRONT ON SOUTHWEST SURFACE WINDS. TEMPERATURES
IN NORTHEAST AND EAST CENTRAL AR ARE MOVING INTO THE LOWER 90S AND
SURFACE BASED CAPES HAVE INCREASED TO BETWEEN 2000 AND 2500 J/KG AND
LIFTED INDICES HAVE DECREASED TO ABOUT MINUS 6.
LATEST HIGH RESOLUTION RAPID REFRESH (HRRR) MODEL INDICATES THAT
SCATTERED SHOWERS AND THUNDERSTORMS WILL BEGIN TO FORM ALONG THE
COLD FRONT BY 3 OR 4 PM...THEN BECOME A LITTLE BETTER ORGANIZED AS
THE STORMS MOVE EAST OF THE MS RIVER BY LATE AFTERNOON AND EVENING.
MODELS CONTINUE TO INDICATE THE ATMOSPHERE WILL BECOME QUITE
UNSTABLE AHEAD OF THE FRONT WITH SURFACE BASED CAPES INCREASING TO
BETWEEN 32000 AND 4200 J/KG WITH LIFTED INDICES DECREASING TO MINUS
8. ALTHOUGH...THE HRRR MODEL INDICATES THE STORMS WILL STRUGGLE IN
COVERAGE WITH SUCH DRY AIR ALOFT LIMITING THE MOISTURE.
ALTHOUGH...THE DRY AIR ALOFT WILL ENHANCE THE DOWNDRAFT POTENTIAL
WITH DAMAGING STRAIGHT LINE WINDS POSSIBLE IN THE STRONGER STORMS.
LARGE HAIL IS ALSO POSSIBLE.
THE COLD FRONT IS FORECAST NEAR THE MS RIVER BY LATE
AFTERNOON...THEN WILL MOVE SOUTHEASTWARD THROUGH THE MIDSOUTH
TONIGHT. THINK THE SEVERE WEATHER THREAT WILL END BY LATE EVENING.
NOT MUCH CHANGE TO THE EARLIER FORECAST CONCERNING TUESDAY THROUGH
THE WEEKEND. HIGH PRESSURE AND DRIER AIR WILL SPREAD OVER THE
MIDSOUTH TUESDAY INTO WEDNESDAY ALLOWING FOR GOOD DIURNAL SPREADS IN
TEMPERATURES WITH RELATIVELY COOL NIGHTS AND VERY WARM AFTERNOONS.
A WARM FRONT IS FORECAST TO PUSH THROUGH THE MIDSOUTH THURSDAY WITH
VERY UNSTABLE AND MOIST AIR SPREADING BACK OVER THE AREA. THIS WILL
CAUSE A CHANCE OF SHOWERS AND THUNDERSTORMS. A COLD FRONT WILL
APPROACH FROM THE NORTHWEST THURSDAY NIGHT AND MOVE SLOWLY THROUGH
THE REGION FRIDAY INCREASING THE THREAT OF SHOWERS AND
THUNDERSTORMS. THERE WILL BE A LINGERING CHANCE OF SHOWERS AND
THUNDERSTORMS ACROSS EAST CENTRAL ARKANSAS AND NORTH MS SATURDAY BUT
OTHERWISE KEPT WITH A RAINFREE FORECAST FOR THE WEEKEND INTO NEXT
MONDAY. HOWEVER...THERE IS SOME QUESTION HOW FAR THE COLD FRONT WILL
SETTLE SOUTHWARD BECOMING STALLING...SO SOME CHANCE OF SHOWERS AND
THUNDERSTORMS COULD LINGER ACROSS EAST CENTRAL AR AND NORTH MS INTO
SUNDAY.
JCL
&&
.AVIATION...
18Z TAF CYCLE
VFR CONDITIONS WILL PERSIST AT TAF SITES FOR THIS TAF PERIOD
OUTSIDE OF THUNDERSTORMS. A LINE OF SHOWERS AND THUNDERSTORMS MAY
DEVELOP NEAR OR JUST EAST OF THE MISSISSIPPI RIVER THIS AFTERNOON
AS THE ATMOSPHERE DESTABILIZES AGAIN AND AN ASSOCIATED COLD FRONT
PUSHES THROUGH THE AREA. SOUTH TO SOUTHWEST WINDS WILL RANGE FROM
10-12 KTS THIS AFTERNOON VEER NORTHWEST TONIGHT AS THE COLD FRONT
PASSES THROUGH THE AREA. MVFR CONDITIONS ALSO POSSIBLE AT MKL/TUP
BETWEEN 14/08-12Z.
SWC
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 70 88 68 93 / 20 0 10 10
MKL 66 86 59 90 / 30 10 10 10
JBR 65 87 62 92 / 10 0 10 10
TUP 71 89 65 91 / 50 10 10 10
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1222 PM CDT MON AUG 13 2012
.DISCUSSION...
SEE AVIATION DISCUSSION BELOW.
&&
.AVIATION...
PORTIONS OF SE TX MAY EXPERIENCE AN ISOLATED THUNDERSTORM LATE
THIS AFTERNOON INTO THE EARLY EVENING. GENERALLY EXPECT THIS
ACTIVITY TO BE ASSOCIATED WITH THE SEABREEZE AND POSSIBLE FROM
OUTFLOWS WHICH MOVE SOUTHWARD FROM ANY ACTIVITY WHICH MAY DEVELOP
NORTH OF KUTS. OTHERWISE EXPECT VFR ALTHOUGH THERE IS AN OUTSIDE
CHANCE OF MVFR CEILINGS AROUND AND AFTER SUNRISE TUESDAY MORNING.
40
&&
.PREV DISCUSSION... /ISSUED 949 AM CDT MON AUG 13 2012/
UPDATE...
MINOR UPDATES FOR TODAY FOR OBSERVED TRENDS AND TO CLEAN UP ZONE
WORDING.
DISCUSSION...
24 HOUR DIFFERENCE FROM 14Z YESTERDAY SHOWS MOST LOCATIONS AT OR
WITHIN A DEGREE OF YESTERDAY. SMALL UPDATES TO HOURLY/MAX TEMPS
AND DEW POINTS FOR TODAY. STILL HOT AND HUMID WITH HEAT INDICES IN
THE 100-105 RANGE. FCST SOUNDINGS AND MDCRS/AIRCRAFT SOUNDINGS
THIS MORNING SHOW 11 TO 12C 700MB TEMPERATURES WHICH SHOULD KEEP
CONVECTION ISOLATED ALONG THE SEA BREEZE TODAY. DID INCLUDE ISO
POPS FOR SOUTHERN COUNTIES JUST INLAND PER 11Z HRRR FCST
REFLECTIVITY FIELDS. SLIGHTLY BETTER SHRA/TSRA CHANCES FOR
NORTHERN AND NORTHEASTERN COUNTIES THIS AFTERNOON FROM LEFTOVER
OUTFLOW BOUNDARIES AND CLOSER TO 850MB TROUGH EVIDENT IN AREA
VWP/PROFILER WINDS. 04
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 99 76 100 76 99 / 20 10 10 10 10
HOUSTON (IAH) 96 78 97 77 96 / 20 10 20 10 10
GALVESTON (GLS) 91 82 90 82 90 / 10 10 20 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...04
AVIATION/MARINE...40
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
949 AM CDT MON AUG 13 2012
.UPDATE...
MINOR UPDATES FOR TODAY FOR OBSERVED TRENDS AND TO CLEAN UP ZONE
WORDING.
&&
.DISCUSSION...
24 HOUR DIFFERENCE FROM 14Z YESTERDAY SHOWS MOST LOCATIONS AT OR
WITHIN A DEGREE OF YESTERDAY. SMALL UPDATES TO HOURLY/MAX TEMPS
AND DEW POINTS FOR TODAY. STILL HOT AND HUMID WITH HEAT INDICES IN
THE 100-105 RANGE. FCST SOUNDINGS AND MDCRS/AIRCRAFT SOUNDINGS
THIS MORNING SHOW 11 TO 12C 700MB TEMPERATURES WHICH SHOULD KEEP
CONVECTION ISOLATED ALONG THE SEA BREEZE TODAY. DID INCLUDE ISO
POPS FOR SOUTHERN COUNTIES JUST INLAND PER 11Z HRRR FCST
REFLECTIVITY FIELDS. SLIGHTLY BETTER SHRA/TSRA CHANCES FOR
NORTHERN AND NORTHEASTERN COUNTIES THIS AFTERNOON FROM LEFTOVER
OUTFLOW BOUNDARIES AND CLOSER TO 850MB TROUGH EVIDENT IN AREA
VWP/PROFILER WINDS. 04
&&
.PREV DISCUSSION... /ISSUED 701 AM CDT MON AUG 13 2012/
DISCUSSION...
12Z TAF DISCUSSION IN AVIATION SECTION BELOW.
AVIATION...
MONITORING SHORT WAVE TROUGH AXIS ROTATING THROUGH NE TX WHICH
HAS KICKED OFF A FEW ISO TSRA TO THE NE OF KUTS/KCXO. POSSIBLE
THAT A FEW SHOWERS/TCU COULD WORK THROUGH THE TERMINALS THIS
MORNING BUT THINK CAPPING IS STRONG ENOUGH FOR NOW. WITH THE
PASSING OF THIS WAVE...MAY HAVE WEAKENED THE CAP ENOUGH FOR ISO TO
SCT TSRA BY THE AFTERNOON. LOCAL WRF-ARW HAS CONVECTION DEVELOPING
AROUND 21-22Z ALONG A PREFRONT TROUGH AHEAD OF A FRONTAL BOUNDARY
THAT COULD AFFECT KCLL/KUTS/KCXO TERMINALS. POSSIBLE SOME OF THIS
CONVECTION COULD WORK SOUTH INTO THE HOUSTON TERMINALS WHILE SEA
BREEZE PUSHES UP FROM THE SOUTH. SEA BREEZE COULD BE THE OTHER
FOCUS FOR CONVECTION SO DECIDED TO AT LEAST PUT VCTS FOR
KCLL/KUTS/KCXO AND KIAH. MODELS NOT REALLY INITIATING CONVECTION
ON THE SEA BREEZE SO NOT AS CONFIDENT WITH VCTS IN KHOU/KSGR TAFS.
WILL LIKELY NEED TO UPDATE OR AMEND DEPENDING ON CONVECTIVE
TRENDS. OTHERWISE EXPECT VFR CIGS WITH SW WINDS BECOMING S/SE WITH
THE DEVELOPING SEA BREEZE DURING THE AFTERNOON.
39
PREV DISCUSSION... /ISSUED 548 AM CDT MON AUG 13 2012/
UPDATE...
A QUICK UPDATE FOR SHOWERS AND THUNDERSTORMS DEVELOPING NEAR
GROVETON WITH THE PASSAGE OF S/W TROUGH AND OTHER SHOWERS AND
THUNDERSTORMS TO THE NORTH NEAR THE SHEAR AXIS. EXPECT THESE TO
WEAKEN AROUND 8-10 AM AND REMAIN GENERALLY NORTH OF MADISONVILLE
TO LIVINGSTON LINE.
45
PREV DISCUSSION... /ISSUED 433 AM CDT MON AUG 13 2012/
DISCUSSION...
UPPER RIDGING OVER NEW MEXICO/WEST TEXAS WILL FLATTEN WITH
NORTHWEST FLOW FROM COLORADO TO MISSISSIPPI WITH SETX ON THE
EASTERN PERIPHERY OF THE RIDGING. S/W TRACKING THROUGH ARKANSAS
THIS MORNING MAY BE AIDING DEVELOPMENT OF SHRA/TSRA NORTHEAST OF
THE AREA NEAR LUFKIN. ANOTHER S/W IN EASTERN COLORADO WILL SWING
DOWN TO THE NORTHERN ZONES LATE THIS AFTERNOON WHICH SHOULD
PROVIDE SOME LIFT BUT THE RIDGES INFLUENCE WITH VERY WARM PROFILES
SHOULD FIGHT THIS WITH CAPPING. THE GREATER CHANCES THOUGH SLIM
WILL BE THE OVER THE NORTHERN COUNTIES THIS AFTERNOON AND EVENING.
ISOLATED SHOWERS OR A THUNDERSTORM WILL BE POSSIBLE NEAR THE COAST
ALONG THE LATE AFTERNOON SEABREEZE. SPEAKING OF SLIM RAIN CHANCES
THESE WILL CONTINUE THROUGH THURSDAY MAINLY DURING THE LATE
AFTERNOON HOURS NEAR THE COAST AND EASTERN COUNTIES WITH THE
WEAKENING OF THE RIDGE AND DAYTIME HEATING POSSIBLY AIDED BY THE
SERIES OF S/W TRACKING SOUTH FROM THE PLAINS INTO THE PERSISTENT
EASTERN U.S. TROUGH UP THROUGH THE GREAT LAKES. EXPECTING
TEMPERATURES DOWN A DEGREE OR TWO THE NEXT FEW DAYS. A LITTLE
DRIER AS WELL SO HEAT INDEX READINGS SHOULD BE IN THE 100-105
DEGREE RANGE...SO NO HEAT ADVISORY NEEDED GIVEN CURRENT FORECAST.
RAIN CHANCES INCREASING ON FRIDAY AS STRONGER S/W MOVES SE TOWARD
THE AREA AND A WEAK COLD FRONT DRIFTS SOUTHWARD TO THE RED
RIVER/NORTHEAST TEXAS REGION. THIS WOULD MAKE FOR GOOD SOURCE OF
THUNDERSTORMS AND WITH THE NORTHWEST/NORTH FLOW ALOFT WOULD CARRY
THESE SOUTH INTO SETX. IN ADDITION AN OPEN WAVE (POSSIBLY REMNANTS
OF TD7) WILL TRACK INTO THE SOUTHWEST GULF PUSHING RICHER MOISTURE
UP INTO SETX LATE FRIDAY THROUGH SUNDAY. COOLING FROM THE CLOUD
COVER AND RETREAT OF RIDGING WESTWARD THIS COMING WEEKEND SHOULD
BRING SOME RELIEF FROM HIGHS IN THE MID- UPPER 90S DURING MID WEEK
TIME FRAME. 45
MARINE...
OVERALL NOT A LOT OF CHANGE IN THE FORECAST AS A TYPICAL SUMMER TIME
PATTERN PERSISTS OVER THE UPPER TX COAST. MODERATE SOUTHERLY WINDS
SHOULD CONTINUE WITH LOW SEAS.
39
AVIATION...
ANOTHER WEAK FRONTAL BOUNDARY MAY APPROACH SE TX TODAY. LOCAL WRF-
ARW SHOWING SOME CONVECTION FORMING FROM KCLL TO KUTS AROUND 22-23Z
THIS EVENING JUST SOUTH OF THE BOUNDARY. OTHERWISE MAY SEE SOME ISO
STORMS FORM ALONG THE SEA BREEZE AGAIN. COVERAGE OF STORMS IS NOT
EXPECTED TO BE ALL THAT MUCH SO WILL LIKELY GO WITH THE WAIT AND SEE
ROUTE. WILL KEEP MENTION OF CONVECTION OUT OF TAFS AND THEN AMEND
ACCORDINGLY AS CONVECTION DEVELOPS IF AT ALL. OTHERWISE THINK VFR
CIGS WILL BE EXPECTED WITH SW/S WINDS TURNING TO THE SE BEHIND THE
SEA BREEZE FOR TERMINALS ALONG THE COAST.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 99 76 100 76 99 / 20 10 10 10 10
HOUSTON (IAH) 96 78 97 77 96 / 20 10 20 10 10
GALVESTON (GLS) 91 82 90 82 90 / 10 10 20 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...04
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1139 PM CDT SUN AUG 12 2012
.AVIATION...
THIS ROUND OF CONVECTION IS OVER FOR THE TAF SITES. VFR CONDITIONS
EXPECTED THROUGH PERIOD. AHEAD OF THE WEAK FRONT THE WINDS WILL
VARY AROUND FROM SOUTHWEST TO WEST...AND THEN SHIFT TO NORTH
NORTHEAST AFTER SUNRISE IN THE METROPLEX AND NEAR NOON AT WACO.
84
&&
.UPDATE...
EXTENDED WATCH SOUTH INTO MILLS COUNTY AND CANCELED FOR AREAS
NORTH OF CONVECTION INCLUDING METROPLEX. 84
&&
.PREV DISCUSSION... /ISSUED 332 PM CDT SUN AUG 12 2012/
ALTHOUGH THE PRIMARY MODEL GUIDANCE REMAINS IN DISAGREEMENT
REGARDING THE CONVECTIVE POTENTIAL THIS EVENING...SHORT-TERM
MESOSCALE TRENDS ARE SUGGESTING THAT THE WETTER NAM...HI-RES WRF
AND HRRR MODELS ARE ON THE RIGHT TRACK. THE COLD FRONT IS MAKING
STEADY PROGRESS TO THE SOUTH AND AT 3 PM HAS PASSED THROUGH
WICHITA FALLS. HOWEVER OBS AND RADAR INDICATE A REGION OF LOW
LEVEL CONFLUENCE FROM ABILENE TO GRAHAM TO BOWIE. THIS AREA WILL
BE THE FAVORABLE REGION FOR INITIATION...AND CONVECTION LOOKS LIKE
IT WILL INITIATE WELL AHEAD OF THE FRONT. LOCAL OBJECTIVE ANALYSIS
INDICATES AN AXIS OF 1000-2500 J/KG OF CAPE ALONG AND EAST OF A
LINE FROM GAINESVILLE TO MINERAL WELLS TO LAMPASAS...WHILE DEEP
LAYER SHEAR IS NOW RUNNING NEAR 35KT ACROSS MUCH OF THE AREA.
UNLIKE PREVIOUS SUMMERTIME CONVECTIVE EVENTS...IT HAS BEEN A
COUPLE MONTHS SINCE WE HAVE HAD THIS MUCH 0-6KM WIND SHEAR
AVAILABLE. GIVEN THE AVAILABLE INSTABILITY AND SHEAR...BRIEF
SUPERCELLS WILL BE POSSIBLE...BUT THE MOST LIKELY CONVECTIVE MODE
WILL BE LINE SEGMENTS. SURFACE TEMPERATURES ARE 105+ ACROSS THE NW
ZONES AHEAD OF THE FRONT...WHILE DEWPOINTS ARE IN THE MID 50S.
THIS WILL CREATE AN EXTREMELY FAVORABLE ENVIRONMENT FOR
DOWNBURSTS. DAMAGING WINDS WILL BE THE PRIMARY THREAT THIS
EVENING...AND BECAUSE DEEP LAYER SHEAR IS AVAILABLE IT WILL ALSO
ENHANCE THE POTENTIAL FOR LINE SEGMENTS PRODUCING ORGANIZED COLD
POOLS. STRONG OUTFLOW WINDS MAY IMPACT A MUCH WIDER AREA THAN
ACTUAL RAINFALL. WILL ALSO INCLUDE A MENTION OF HAIL IN
HWO..ALTHOUGH HOT TEMPS MAY LIMIT HAIL SIZE. THE SCATTERED
CONVECTION IS EXPECTED TO TRACK NORTHWEST TO SOUTHEAST ACROSS THE
CWA THIS EVENING...AND THE HIGHEST POPS WILL BE PLACED IN A BAND
ACROSS THE CENTRAL CWA.
THE TRUE COLD FRONT WILL LIKELY BE TEMPORARILY HELD UP AS OUTFLOW
FROM CONVECTION OVER OUR AREA RESULTS IN PREDOMINANTLY SOUTHERLY
WINDS ON ITS NORTH SIDE. FRONT PROBABLY WILL NOT REACH THE
METROPLEX UNTIL DAYBREAK AND WILL LIKELY PUSH INTO THE SOUTHERN ZONES
BY AFTERNOON. HIGH TEMPERATURES TOMORROW WILL BE TRICKY...WITH
LOCATIONS ALONG AND SOUTH OF THE FRONT IN THE AFTERNOON BENEFITING
FROM SUBSIDENCE WARMING AND THE TEMPS FORECAST HERE MAY BE TOO
LOW. ON THE OTHER HAND...CURRENT OBSERVATIONS SUGGEST THE FRONT
HAS A STRONG PUSH...AND THEREFORE AM LEANING TOWARD THE GUIDANCE
THAT SHOWS SOME DECENT COLD ADVECTION IN THE LOW LEVELS ACROSS THE
NORTH AND NORTHEAST ZONES. WILL RETAIN A MENTION OF LOW POPS IN
THE SOUTHERN ZONES TOMORROW WHERE THE FRONT SHOULD BECOME ACTIVE
IN THE AFTERNOON HOURS.
NORTHWEST FLOW ALOFT WILL REMAIN IN PLACE THROUGH TUESDAY. MODEL
GUIDANCE IS HAVING SOME TIMING DIFFERENCES WITH RESPECT TO THE
NEXT SHORTWAVE...EITHER AS EARLY AS TUESDAY MORNING AND AS LATE AS
OVERNIGHT TUESDAY. INSTABILITY/SHEAR WILL BE SUFFICIENT FOR A MCS
OR REMNANT MCS OUTFLOW TO AFFECT THE AREA FROM OKLAHOMA DURING
THIS TIME. WILL CONTINUE WITH SLIGHT CHANCE POPS TUESDAY AND TUESDAY
NIGHT. SOUTHERLY WINDS RETURN BY WEDNESDAY AND NORTHWEST FLOW
ALOFT WEAKENS. CONVECTIVE POTENTIAL SHOULD ALSO DIMINISH...WHILE
TEMPS RETURN TO NEAR 100 DEGREES AREA WIDE THROUGH THURSDAY.
IN THE EXTENDED...THE STRONGER COLD FRONT STILL LOOKS ON TRACK.
IT SHOULD ARRIVE FRIDAY MORNING AND GRADUALLY WORK SOUTH THROUGH
THE REGION INTO SATURDAY MORNING. WILL CONTINUE WITH LOW POPS
STARTING THURSDAY NIGHT IN THE NORTH...WITH 30 PERCENT EVERYWHERE
FRIDAY. WILL HAVE POPS GRADUALLY CLEAR OUT FROM NORTH TO SOUTH ON
SATURDAY. THE LINGERING POPS ON SATURDAY ARE FAVORING THE GFS
SOLUTION WHICH IS WEAKER WITH THE FRONT...AND MAKES SENSE GIVEN
THE TIME OF THE YEAR. THE WEAKER THE FRONT...THE LONGER IT WILL
TAKE FOR IT TO CLEAR OUT THE MOISTURE. REGARDLESS...HIGH
TEMPERATURES SHOULD DROP INTO THE LOW 90S THIS WEEKEND DUE TO
EITHER LOWER THICKNESS VALUES AND/OR INCREASED CLOUDS/RAIN.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 77 99 73 98 76 / 10 10 5 10 20
WACO, TX 77 101 72 100 76 / 20 10 10 10 10
PARIS, TX 73 97 66 95 70 / 10 10 5 10 20
DENTON, TX 73 98 67 97 72 / 10 5 5 20 20
MCKINNEY, TX 73 98 67 96 71 / 10 10 5 10 20
DALLAS, TX 78 99 74 98 76 / 10 10 5 10 20
TERRELL, TX 77 99 70 96 73 / 10 10 5 10 20
CORSICANA, TX 76 100 73 98 75 / 20 10 5 10 20
TEMPLE, TX 75 100 72 100 75 / 20 20 10 10 10
MINERAL WELLS, TX 71 100 66 99 71 / 10 5 5 20 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
620 PM EDT MON AUG 13 2012
.SYNOPSIS...
HIGH PRESSURE WILL EXIT THE REGION TONIGHT AND MAKE WAY FOR AN
APPROACHING COLD FRONT. THIS FRONT WILL MOVE THROUGH THE REGION
TOMORROW EVENING. IN ITS WAKE...HIGH PRESSURE WILL RETURN TO THE
REGION WITH YET ANOTHER...AND PERHAPS STRONGER...COLD FRONT SLATED
TO CROSS THE REGION FRIDAY INTO SATURDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS OF 612 PM EDT MONDAY...
EARLY EVENING UPDATE MAINLY TO REDUCE POPS ACROSS THE SW THIS
EVENING GIVEN MAIN AXIS OF SHRA PASSING TO THE SW...AND THEN TO
INCLUDE SOME CHANCE POPS AFTER MIDNIGHT ACROSS THE WEST PER SHRA
DEVELOPMENT BEHIND THE PRE-FRONTAL RH LOBE ATTM. THIS SUPPORTED
VIA THE LATEST HRRR WHICH BRINGS SOME OF THIS LEFTOVER CONVECTION
INTO THE WESTERN ZONES LATE IN CONJUNCTION WITH MOISTENING OF MID
LEVELS OFF LATEST FORECAST RAOBS. ALSO LOWERED TEMPS SOME OVER THE
SW WHERE HEATING WAS LESS DUE TO EARLY ARRIVAL OF THE MID DECK
CANOPY.
AS OF 315 PM EDT MONDAY...
INFLUENCE OF HIGH PRESSURE WILL CONTINUE THROUGH THIS EVENING.
PRECIPITATION WILL BE VERY LIMITED...IF EXISTS AT ALL. THE GREAT
POTENTIAL WILL BE ALONG THE CREST OF THE BLUE RIDGE SOUTHWEST OF
FLOYD INTO THE NORTHERN MOUNTAINS OF NORTH CAROLINA...AND IN AREAS
ALONG AND NEAR THE NC/VA BORDER.
OVERNIGHT...MID TO HIGH LEVEL CLOUD COVER IS EXPECTED TO OVERSPREAD
THE REGION AS DEBRIS CLOUD COVER FROM AN APPROACHING COLD FRONT
ADVECTS INTO THE REGION. THIS WILL HAVE THE RESULT OF
LIMITED...ALTHOUGH NOT COMPLETELY PREVENTING...THE DEVELOPMENT OF
PRIMARILY LATE NIGHT MOUNTAIN VALLEY FOG...ESPECIALLY OVER PARTS OF
THE GREENBRIER AND NEW RIVER VALLEYS. SOME ISOLATED TO SCATTERED
SHOWERS WILL BE POSSIBLE OVER SOUTHEAST WEST VIRGINIA BY SUNRISE IN
ASSOCIATION WITH THE APPROACHING FRONT.
ON TUESDAY...THE FRONT WILL DRAW EVEN CLOSE TO THE REGION DURING THE
DAY TUESDAY. ISENTROPIC LIFT IN ADVANCE OF THE FRONT WILL HELP TO
PROVIDE GENEROUS COVERAGE OF SHOWERS AND STORMS BY MIDDAY ACROSS ALL
BUT THE FAR EASTERN SECTIONS OF THE REGION. BY THE LATE
AFTERNOON...ALL AREAS ARE EXPECTED TO HAVE AT LEAST SCATTERED
COVERAGE OF SHOWERS AND STORMS...WITH THE GREATEST COVERAGE ACROSS
SOUTHEAST WEST VIRGINIA AND AREAS ALONG AND NEAR THE CREST OF THE
BLUE RIDGE.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
AS OF 112 PM EDT MONDAY...
JUST SOME MINOR TWEAKS TO THE PREVIOUS FORECAST FOR THIS TIME
PERIOD. MODELS SHOW A DECENT SHORTWAVE SHIFTING EAST ACROSS THE ARE
TUE NIGHT INTO WED MORNING...SO EXPECT TO SEE LINGERING SHOWERS OR
STORMS IN THE EAST TUE EVENING AND SOME UPSLOPE ENHANCE SHOWERS
ACROSS THE MTNS INTO WED MORNING BEFORE SUBSIDENCE STARTS TO DRY THE
COLUMN OUT SUBSTANTIALLY. THE UPPER FLOW STAYS IN A GENERAL WRLY
DIRECTION AFTER THE FRONTAL PASSAGE AND ONLY EXPECTING MEAGER DROPS
IN THE DEWPOINTS WITH TEMPS REMAINING JUST AS WARM AS TUESDAY.
A WEAK HIGH PRESSURE SYSTEM LINGERS ACROSS THE AREA INTO THURSDAY
DURING WHICH SKIES SHOULD REMAIN CLEAR-PARTLY CLOUDY.
SHOULD SEE INCREASING CLOUDS AHEAD OF NEXT TROUGH AND SFC FRONT LATE
THU NIGHT...BUT ANY PRECIP SHOULD HOLD OFF UNTIL FRIDAY.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 112 PM EDT MONDAY...
POSITIVE PNA PATTERN WITH TROUGH IN THE EASTERN U.S./TROUGH WEST
COAST WILL BE THE UPPER AIR FLOW INTO THE EXTENDED PERIOD WITH SOME
BREAKDOWN IN THE WRN RIDGE AFTER NEXT MONDAY.
THE NEXT FRONT WILL SLIDE INTO THE AREA FRIDAY INTO SATURDAY. UPPER
PATTERN SUPPORTS SLOWER MOVEMENT OF FRONT AND COULD SEE THE FRONT
STALL JUST SOUTH AND EAST OF THE FORECAST AREA OVER THE WEEKEND. THE
ECMWF ALLUDES TO MORE CLOUDS ACROSS THE SRN CWA INTO SUNDAY WITH AN
INCREASE IN PRECIP CHANCES HEADING INTO MONDAY ACROSS SRN VA/NRN NC.
FOR NOW WILL KEEP THE AREA DRY MONDAY...PER HPC AND ENSEMBLE
LEANINGS...GIVEN THE TROUGH DOES LOOK TO DEEPEN JUST ENOUGH.
SO FOR THIS PERIOD...THINK AT LEAST A CHANCE POPS WARRANTED FRI-SAT
WITH SOME DRYING ACROSS THE REGION SAT NIGHT-SUN WITH A FEW
LINGERING SHOWERS IN THE PIEDMONT...THEN MAINLY DRY WITH INCREASING
CLOUDS AROUND SUN NIGHT INTO MONDAY ACROSS THE PIEDMONT SOUTHWEST
INTO THE NC FOOTHILLS.
TEMPS THIS PERIOD SHOULD COOL OFF AGAIN TOWARD WHAT WE HAD THIS PAST
WEEKEND WITH HIGHS IN THE 70S WEST TO LOWER 80S EAST...WHILE LOWS AT
NIGHT RANGE FROM THE LOWER 50S WEST TO LOWER 60S EAST.
&&
.AVIATION /22Z MONDAY THROUGH SATURDAY/...
AS OF 140 PM EDT MONDAY...
VFR CONDITIONS ARE EXPECTED THROUGH THE EVENING HOURS FOR THE VAST
MAJORITY OF THE REGION. ISOLATED SHOWERS...AND PERHAPS A
THUNDERSTORM OR TWO...ARE POSSIBLE THIS AFTERNOON MAINLY NEAR THE
NC/VA BORDER...AND ALONG THE CREST OF THE BLUE RIDGE FROM SOUTH OF
KROA TO NEAR KTNB. OVERNIGHT...MID TO HIGH LEVEL CLOUDINESS WILL
OVERSPREAD THE AREA IN ADVANCE OF OUR NEXT COLD FRONT. THIS WILL
LIMIT THE EXTENT OF ANY MVFR MOUNTAIN OR RIVER VALLEY FOG. THE
ADVANCING COLD FRONT WILL PROMPT AN INCREASE IN SHOWERS AND STORMS
DURING THE DAY TOMORROW. ANTICIPATE THE KBLF-KLWB AREA WILL HAVE
SCATTERED SHOWERS AND PERHAPS A RUMBLE OR TWO OF THUNDER AFTER
14Z...10AM. HAVE INDICATED VCSH IN THE WEATHER GROUP AT THESE TAF
SITES TOMORROW TO INDICATE THIS.
LOCALIZED SUB-VFR CIGS AND VSBYS WILL BE POSSIBLE UNDER THE
STRONGEST CONVECTIVE CELLS TUESDAY AND TUESDAY EVENING.
NIGHTTIME SUB-VFR MOUNTAIN OR RIVER VALLEY FOG WILL BE POSSIBLE
THIS WEEK...ESPECIALLY IN AREAS THAT RECEIVE RAIN ON TUESDAY.
INCREASED COVERAGE OF SHOWERS AND STORMS AGAIN FRIDAY INTO
SATURDAY WITH THE PASSAGE OF THE NEXT COLD FRONT.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...DS
NEAR TERM...DS/JH
SHORT TERM...WP
LONG TERM...WP
AVIATION...DS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1057 PM CDT TUE AUG 14 2012
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND WEDNESDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW WEAK HIGH
PRESSURE CENTERED OVER THE MISSISSIPPI VALLEY EARLY THIS AFTERNOON.
DIURNAL CU HAS BEEN FEISTY IN SPOTS WITH A FEW SHOWERS POPPING UP
OVER CENTRAL AND SOUTHERN WISCONSIN AND ALSO OVER THE UPPER
PENINSULA. MEANWHILE UPSTREAM...A BAND OF MID AND HIGH LEVEL CLOUDS
ARE PUSHING SOUTHEAST OVER MINNESOTA WHERE AREA RADARS ARE PICKING
UP ON WEAK RETURNS. EVEN FARTHER WEST..THE NEXT STORM SYSTEM IS
GATHERING STRENGTH NORTH OF THE MONTANA BORDER. AS RETURN FLOW
DEVELOPS ALOFT AND MID LEVEL CLOUDS ARRIVE...CLOUD COVER AND SMALL
PRECIP CHANCES ARE THE MAIN FORECAST CONCERNS OVER THE NEXT 24 HOURS.
TONIGHT...ANY SPOTTY SHOWERS THIS AFTERNOON WILL DIMINISH EARLY WITH
LOSS OF HEATING. OTHERWISE...NORTHWEST FLOW ALOFT WILL PREVAIL
ACROSS THE STATE AND BRING IN A BATCH OF MID AND HIGH CLOUDS FROM
MINNESOTA. WEAK LIFT ALONG THE 700MB THETAE GRADIENT MAY EVEN TRY
TO BRING A FEW SHOWERS TO CENTRAL WISCONSIN AFTER MIDNIGHT. WILL BE
FALLING OUT OF A MID DECK AND NOT CONFIDENT THAT ANY SHOWERS WILL
MEASURE...BUT WILL ADD A SLIGHT CHANCE TO THE FORECAST. WITH THE
CLOUD COVER...NOT EXPECTING A REPEAT OF THE FOG OVER N-C WISCONSIN
TONIGHT. A PARTLY TO MOSTLY CLOUDY NIGHT WITH LOWS RANGING THROUGH
THE 50S.
WEDNESDAY...AS A STRONG COLD FRONT MOVES INTO MINNESOTA...SW TO WEST
WINDS WILL BE WARM AND MOIST ADVECTING BETWEEN 850-700MB ACROSS THE
AREA OVER THE COURSE OF THE DAY. PROGGED SOUNDINGS DRY OUT BELOW
800MB...BUT PRECIP OVER THE EASTERN DAKOTAS AND MINNESOTA IS STILL
REACHING THE GROUND SO WILL EXPAND SLIGHT CHANCE OF SHOWERS TO THE
WESTERN FOX VALLEY. MID-LEVEL LAPSE RATE GRADIENT WILL ALSO NUDGE
INTO CENTRAL WISCONSIN INTO THE AFTERNOON...AND WILL KEEP A MENTION
OF ISOLATED THUNDER THERE. WITH THE BKN MID CLOUD DECK AND POTENTIAL
FOR LIGHT SHOWERS...TEMPERATURES WILL BE A STRUGGLE...MORE OR LESS
WENT WITH A BLEND OF THE PREVIOUS FORECAST WITH THE BCALLBLEND.
THIS WOULD PUT HIGHS IN THE UPPER 70S NORTH TO MID 80S SOUTH.
.LONG TERM...WEDNESDAY NIGHT THROUGH NEXT TUESDAY. THE MODELS ARE
NOW IN GOOD AGREEMENT WITH MOVING THE UPPER TROUGH FROM THE
CANADIAN ROCKIES TO GREAT LAKES OVER THE NEXT SEVERAL DAYS WITH A
REINFORCING UPPER TROUGH SATURDAY. THIS SHOULD KEEP CYCLONIC UPPER
FLOW ACROSS THE REGION THROUGH THE PERIOD WITH COOLER THAN NORMAL
TEMPERATURES AND DRY WEATHER MOST OF THE TIME.
SHOWERS AND THUNDERSTORMS WILL ARRIVE IN THE WESTERN PORTION OF
THE FORECAST AREA LATE WEDNESDAY NIGHT IN AN AREA OF UPPER
DIFFLUENCE AND LOW LEVEL WARM ADVECTION AND MOISTURE CONVERGENCE.
THE ARRIVAL OF THE FRONT DURING THE NIGHT TIME HOURS WILL MINIMIZE
THE SEVERAL THREAT. THE ACTIVITY WILL MOVE ACROSS EASTERN
WISCONSIN THURSDAY MORNING AND SHOULD EXIT THE AREA DURING THE
AFTERNOON. BREEZY AND COOLER THURSDAY NIGHT AND FRIDAY AS UPPER
HEIGHTS FALL AND BIG COOL SURFACE HIGH BUILDS IN FROM THE NORTHERN
PLAINS. CLEAR SKIES AND LIGHT WINDS SHOULD ALLOW TEMPERATURES TO
FALL INTO THE 30S IN THE USUAL COOL PLACES FRIDAY NIGHT WITH
POSSIBLE FROST.
AN UPPER TROUGH AND ASSOCIATED SURFACE FRONT WILL BRING A
REINFORCING PUSH OF COOL AIR SATURDAY AFTERNOON AND MAY BE
ACCOMPANIED BY A FEW SHOWERS. SCATTERED SHOWERS POSSIBLE ALSO
SUNDAY AFTERNOON IN CYCLONIC COLD UPPER FLOW.
&&
.AVIATION...MAINLY MID/HIGH CLOUDS WILL AFFECT THE REGION OVERNIGHT
INTO WEDNESDAY. SOME MVFR/IFR FOG IS EXPECTED TO DEVELOP OVERNIGHT...
ESPECIALLY IN THE FAVORED AREAS OF NC WI...INCLUDING THE RHI TAF SITE.
SCT LIGHT SHOWERS MAY FALL FROM A MID-LEVEL CLOUD DECK IN PARTS
OF CENTRAL WI LATE TONIGHT...AND OVER MOST OF THE FORECAST AREA ON
WEDNESDAY. SCT SHRA/TSRA SHOULD DEVELOP IN NC/C WI LATE WEDS EVG...
AS A COLD FRONT APPROACHES FROM MINNESOTA. MORE WIDESPREAD TSTM
ACTIVITY WILL OCCUR LATE WEDS NGT INTO THU MORNING...BEYOND THE
SCOPE OF THIS TAF PERIOD. HAVE ADDED SOME BORDERLINE LLWS TO THE
TAFS WEDS EVG...AS S-SW WINDS INCREASE TO 30-35 KTS JUST OFF THE
SURFACE.
KIECKBUSCH
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
637 PM CDT TUE AUG 14 2012
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND WEDNESDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW WEAK HIGH
PRESSURE CENTERED OVER THE MISSISSIPPI VALLEY EARLY THIS AFTERNOON.
DIURNAL CU HAS BEEN FEISTY IN SPOTS WITH A FEW SHOWERS POPPING UP
OVER CENTRAL AND SOUTHERN WISCONSIN AND ALSO OVER THE UPPER
PENINSULA. MEANWHILE UPSTREAM...A BAND OF MID AND HIGH LEVEL CLOUDS
ARE PUSHING SOUTHEAST OVER MINNESOTA WHERE AREA RADARS ARE PICKING
UP ON WEAK RETURNS. EVEN FARTHER WEST..THE NEXT STORM SYSTEM IS
GATHERING STRENGTH NORTH OF THE MONTANA BORDER. AS RETURN FLOW
DEVELOPS ALOFT AND MID LEVEL CLOUDS ARRIVE...CLOUD COVER AND SMALL
PRECIP CHANCES ARE THE MAIN FORECAST CONCERNS OVER THE NEXT 24 HOURS.
TONIGHT...ANY SPOTTY SHOWERS THIS AFTERNOON WILL DIMINISH EARLY WITH
LOSS OF HEATING. OTHERWISE...NORTHWEST FLOW ALOFT WILL PREVAIL
ACROSS THE STATE AND BRING IN A BATCH OF MID AND HIGH CLOUDS FROM
MINNESOTA. WEAK LIFT ALONG THE 700MB THETAE GRADIENT MAY EVEN TRY
TO BRING A FEW SHOWERS TO CENTRAL WISCONSIN AFTER MIDNIGHT. WILL BE
FALLING OUT OF A MID DECK AND NOT CONFIDENT THAT ANY SHOWERS WILL
MEASURE...BUT WILL ADD A SLIGHT CHANCE TO THE FORECAST. WITH THE
CLOUD COVER...NOT EXPECTING A REPEAT OF THE FOG OVER N-C WISCONSIN
TONIGHT. A PARTLY TO MOSTLY CLOUDY NIGHT WITH LOWS RANGING THROUGH
THE 50S.
WEDNESDAY...AS A STRONG COLD FRONT MOVES INTO MINNESOTA...SW TO WEST
WINDS WILL BE WARM AND MOIST ADVECTING BETWEEN 850-700MB ACROSS THE
AREA OVER THE COURSE OF THE DAY. PROGGED SOUNDINGS DRY OUT BELOW
800MB...BUT PRECIP OVER THE EASTERN DAKOTAS AND MINNESOTA IS STILL
REACHING THE GROUND SO WILL EXPAND SLIGHT CHANCE OF SHOWERS TO THE
WESTERN FOX VALLEY. MID-LEVEL LAPSE RATE GRADIENT WILL ALSO NUDGE
INTO CENTRAL WISCONSIN INTO THE AFTERNOON...AND WILL KEEP A MENTION
OF ISOLATED THUNDER THERE. WITH THE BKN MID CLOUD DECK AND POTENTIAL
FOR LIGHT SHOWERS...TEMPERATURES WILL BE A STRUGGLE...MORE OR LESS
WENT WITH A BLEND OF THE PREVIOUS FORECAST WITH THE BCALLBLEND.
THIS WOULD PUT HIGHS IN THE UPPER 70S NORTH TO MID 80S SOUTH.
.LONG TERM...WEDNESDAY NIGHT THROUGH NEXT TUESDAY. THE MODELS ARE
NOW IN GOOD AGREEMENT WITH MOVING THE UPPER TROUGH FROM THE
CANADIAN ROCKIES TO GREAT LAKES OVER THE NEXT SEVERAL DAYS WITH A
REINFORCING UPPER TROUGH SATURDAY. THIS SHOULD KEEP CYCLONIC UPPER
FLOW ACROSS THE REGION THROUGH THE PERIOD WITH COOLER THAN NORMAL
TEMPERATURES AND DRY WEATHER MOST OF THE TIME.
SHOWERS AND THUNDERSTORMS WILL ARRIVE IN THE WESTERN PORTION OF
THE FORECAST AREA LATE WEDNESDAY NIGHT IN AN AREA OF UPPER
DIFFLUENCE AND LOW LEVEL WARM ADVECTION AND MOISTURE CONVERGENCE.
THE ARRIVAL OF THE FRONT DURING THE NIGHT TIME HOURS WILL MINIMIZE
THE SEVERAL THREAT. THE ACTIVITY WILL MOVE ACROSS EASTERN
WISCONSIN THURSDAY MORNING AND SHOULD EXIT THE AREA DURING THE
AFTERNOON. BREEZY AND COOLER THURSDAY NIGHT AND FRIDAY AS UPPER
HEIGHTS FALL AND BIG COOL SURFACE HIGH BUILDS IN FROM THE NORTHERN
PLAINS. CLEAR SKIES AND LIGHT WINDS SHOULD ALLOW TEMPERATURES TO
FALL INTO THE 30S IN THE USUAL COOL PLACES FRIDAY NIGHT WITH
POSSIBLE FROST.
AN UPPER TROUGH AND ASSOCIATED SURFACE FRONT WILL BRING A
REINFORCING PUSH OF COOL AIR SATURDAY AFTERNOON AND MAY BE
ACCOMPANIED BY A FEW SHOWERS. SCATTERED SHOWERS POSSIBLE ALSO
SUNDAY AFTERNOON IN CYCLONIC COLD UPPER FLOW.
&&
.AVIATION...MAINLY MID/HIGH CLOUDS WILL AFFECT THE REGION TONIGHT
AND WEDNESDAY. SOME SPOTTY MVFR/IFR FOG MAY DEVELOP OVERNIGHT IF
THE CLOUDS THIN OUT ENOUGH...ESPECIALLY IN THE FAVORED AREAS OF
NC WI. SCT LIGHT SHOWERS MAY FALL FROM A MID-LEVEL CLOUD DECK IN
PARTS OF CENTRAL WI LATE TONIGHT...AND OVER MOST OF THE FORECAST
AREA ON WEDNESDAY.
KIECKBUSCH
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
610 PM CDT TUE AUG 14 2012
.SHORT TERM...TONIGHT THROUGH FRIDAY
300 PM CDT TUE AUG 14 2012
SHOWER/THUNDERSTORM CHANCES THROUGH THURSDAY AND TEMPERATURES ARE
THE MAIN CONCERN THROUGH THE SHORT TERM PERIOD.
LATEST WATER VAPOR IMAGERY ALONG WITH RAP 500MB HEIGHT ANALYSIS
SHOWS A COUPLE MID-LEVEL SHORTWAVE TROUGHS DROPPING THROUGH
NORTHWEST FLOW ALOFT ACROSS IA AND MN INTO NEBRASKA. MORE ENERGETIC
WAVE POISED TO AFFECT THE AREA IN THE NEXT 12-24 HOURS WAS MAKING
ITS WAY SOUTHEAST ACROSS THE ALBERTA ROCKIES. RADAR MOSAIC
SHOWING A BAND OF SCATTERED ELEVATED SHRA ACTIVITY ACROSS SOUTHEAST
ND INTO SOUTHWEST MN IN DECENT ISENTROPIC LIFT/MOISTURE TRANSPORT
AHEAD OF THE MN/NEB WAVE AND SURFACE WARM FRONT. MEANWHILE...
VISIBLE SATELLITE SHOWING AN EXPANSIVE FIELD OF CUMULUS ACROSS THE
LOCAL FORECAST AREA WITH INFLUENCE OF LINGERING COLD AIR ALOFT/STEEP
LAPSE RATES. TEMPERATURES ACROSS THE AREA AT 2 PM WERE IN THE 70S
TO LOWER 80S.
14.12Z NCEP MODELS/14.09Z SREF IN GOOD AGREEMENT WITH SYNOPTIC SETUP
THROUGH THE SHORT TERM PERIOD.
WILL BE WATCHING THE MN-NEB MID-LEVEL TROUGH AND SURFACE WARM FRONT
APPROACH THE AREA THIS EVENING/OVERNIGHT. NAM INDICATING
INCREASING/IMPRESSIVE 305K ISENTROPIC LIFT ALONG WITH STRONG
850-700MB FRONTOGENESIS/MOISTURE TRANSPORT AHEAD OF THE WARM FRONT
FOR ACCAS DEVELOPMENT ALONG WITH LIKELIHOOD OF SHRA/ISOLD T
ACTIVITY. BASED ON THIS SIGNAL...BUMPED POPS INTO 50-60 PERCENT
RANGE...WITH AREAS FROM LAKE CITY MN THROUGH LA CROSSE AND VIROQUA
LIKELY BEING THE AXIS OF HIGHEST PROBABILITIES. RIGHT NOW...IT
APPEARS THUNDER WILL BE ISOLATED IN NATURE WITH ELEVATED
CAPE/850-700MB ONLY APPROACHING 500J/KG.
GOOD CHANCE OF LINGERING SHRA/ISOLD THUNDER FOR AREAS ALONG/NORTH OF
I-94 WEDNESDAY MORNING AS THE WARM FRONT PUSHES THROUGH SOUTHEAST MN
INTO SOUTHWEST WI. APPEARS THE WARM FRONT WILL PUSH NORTHEAST OF THE
AREA BY AFTERNOON WITH THE AREA IN GENERAL WARM AIR ADVECTION AHEAD
OF A FAIRLY STRONG COLD FRONT PUSHING EAST ACROSS MN. KEPT SLIGHT
SHRA/TS CHANCES IN FOR AREAS ALONG/NORTHEAST OF I-94 THROUGH THE
AFTERNOON TO ACCOUNT FOR EXITING WARM FRONT. OTHERWISE...LOOK FOR
TEMPERATURES TO TOP OFF IN THE MIDDLE/UPPER 80S SOUTHWEST OF I-94
AND IN THE UPPER 70S/AROUND 80 NORTHEAST OF I-94 WITH MORE CLOUD
COVER THERE.
WILL HAVE TO WATCH FOR SEVERE POTENTIAL GOING INTO WEDNESDAY
EVENING. ANTICIPATING A FAIRLY SOLID LINE OF THUNDERSTORMS FIRING
ALONG THE COLD FRONT ACROSS MN INTO NORTHWEST IA BY LATER WEDNESDAY
AFTERNOON AS 0-3KM MUCAPE PUSH INTO THE 2500-5000J/KG RANGE ALONG
WITH AMPLE BULK SHEAR. THIS FRONT/LINE OF THUNDERSTORMS WILL BE
MOVING INTO THE AREA WEDNESDAY EVENING/OVERNIGHT. LINE SHOULD BE IN
A WEAKENING STATE OVERNIGHT AS CAPE WANES. HOWEVER..CANNOT RULE OUT
SEVERE HAIL/WIND THREAT FOR WESTERN PORTIONS OF THE FORECAST
AREA...MAINLY WEST OF A LINE FROM LAKE CITY AND ROCHESTER MN...TO
CHARLES CITY IA.
LOOK FOR THE COLD FRONT TO PUSH SOUTHEAST OF THE AREA BY THURSDAY
MORNING...TAKING THE BULK OF THE SHOWER/THUNDERSTORMS WITH IT.
HOWEVER...IT APPEARS A SECONDARY TROUGH/SURFACE REFLECTION OF
MID-LEVEL TROUGH LAGS THE COLD FRONT FOR SHRA/TS CHANCES LINGERING
THROUGH THE MORNING HOURS ACROSS THE ENTIRE AREA AND SOUTHEAST OF A
MAUSTON TO PRAIRIE DU CHIEN LINE DURING THE AFTERNOON.
MEANWHILE...VERY COLD AIR ALOFT/STEEPENING LAPSE RATES DURING THE
AFTERNOON ALSO EXPECTED TO KICK OFF QUITE A BIT OF CUMULUS ACROSS
THE REMAINDER OF THE AREA. HIGHS ON THURSDAY ONLY EXPECTED TO TOP
OFF IN THE UPPER 60S TO MIDDLE 70S.
THURSDAY NIGHT THROUGH FRIDAY WILL BE COOLER THAN NORMAL WITH DEEP
MID-LEVEL TROUGH DIGGING INTO THE CENTRAL CONUS/GREAT LAKES REGIONS.
CUMULUS FIELD SHOULD BE QUITE IMPRESSIVE FRIDAY AFTERNOON AS WELL
WITH THE COLD AIR ALOFT/STEEP LAPSE RATES. LOOK FOR LOWS IN THE
UPPER 40S/LOWER 50S THURSDAY NIGHT AND HIGHS ON FRIDAY IN THE UPPER
60S/LOWER 70S.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
300 PM CDT TUE AUG 14 2012
LATEST GFS/ECMWF SHOWING LONG WAVE TROUGH CARVED OUT ACROSS THE
UPPER MISSISSIPPI RIVER VALLEY/GREAT LAKES REGION. STEEP LAPSE RATES
WILL EXIST THROUGH THE PERIOD WITH MODELS SHOWING A SHORTWAVE TROUGH
DROPPING IN ACROSS THE AREA SATURDAY FOR A TRIGGER FOR ISOLATED SHRA
DEVELOPMENT. LOOKS LIKE ANOTHER INNOCUOUS EMBEDDED SHORTWAVE TROUGH
WITHIN THE LONG WAVE/COLD TROUGH MAY BE ENOUGH ON SUNDAY FOR ANOTHER
ROUND OF ISOLATED SHOWERS. TEMPERATURES WILL REMAIN COOLER THAN
NORMAL UNDER THE TROUGH WITH HIGHS SATURDAY/SUNDAY TOPPING OFF IN
THE UPPER 60S/LOWER 70S. LOOK FOR THE TROUGH AXIS TO MOVE EAST OF
THE AREA ON MONDAY WITH SOME RIDGING ALOFT FOR DRIER AND SLIGHT
WARMER CONDITIONS. HIGHS ON MONDAY EXPECTED TO BE IN THE LOW/MID 70S.
THE GFS/EC DIVERGE ON THEIR SOLUTION ON TUESDAY. THE GFS BRINGS A
WING OF WARM AIR ADVECTION -SHRA/TS ACTIVITY INTO THE AREA WHEREAS
THE ECMWF MAINTAINS DRY SCENARIO IN WARM AIR ADVECTION. WENT WITH
MODEL CONSENSUS WHICH YIELDS A SLIGHT CHANCE OF SHOWER AND
THUNDERSTORMS. OTHERWISE...HIGHS ON TUESDAY EXPECTED TO WARM INTO
THE UPPER 70S/LOWER 80S.
&&
.AVIATION...TONIGHT AND WEDNESDAY
610 PM CDT TUE AUG 14 2012
THE MAIN FOCUS AT THE TAF SITES INITIALLY IS WITH THE RAIN CHANCES
TONIGHT AS A WARM FRONT BEGINS TO LIFT BACK TO THE NORTH THROUGH
THE REGION. LIGHT RAIN SHOWERS HAVE ALREADY BEGUN TO FALL OUT OF A
10KFT DECK WITH VISIBILITY STAYING UP AT P6SM. EXPECT MUCH OF THE
SAME THIS EVENING BEFORE THE LOW LEVEL FORCING INCREASES TOWARD
MIDNIGHT WHEN SHOWERS SHOULD BECOME MORE PREVALENT. STILL...WITH
A DRY LOW LEVEL AIR MASS IN PLACE...THINKING THAT CONDITIONS
SHOULD STAY VFR WITH CIGS UP AROUND 5-8KFT AND VISIBILITY AT 6SM
OR BETTER.
AFTER THE FRONT LIFTS NORTH OVERNIGHT...WINDS WILL COME AROUND TO
THE SOUTH AND BECOME GUSTY BETWEEN 20-25KT TOMORROW AFTERNOON
AHEAD OF THE NEXT SYSTEM. A COLD FRONT WILL BE MARCHING ACROSS
MINNESOTA WITH SHOWERS/THUNDERSTORMS DEVELOPING ALONG/AHEAD OF
IT...BUT THEY SHOULD NOT BE INTO RST BEFORE 00Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
300 PM CDT TUE AUG 14 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
259 PM CDT MON AUG 13 2012
.SHORT TERM...TONIGHT AND TUESDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SHORTWAVE
TROUGHING MOVING ACROSS EASTERN WISCONSIN EARLY THIS AFTERNOON. A
SECONDARY FRONT IS MOVING INTO NORTHWEST WISCONSIN AS WELL WHICH IS
INTERACTING WITH STEEP LOW LEVEL LAPSE RATES AND 200-400 J/KG OF ML
CAPE TO CREATE SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS.
LOOKING UPSTREAM...PLENTY OF CU OVER MINNESOTA AND SOUTH-CENTRAL
CANADA WHERE ADDITIONAL WEAK SHORTWAVE ENERGY IS MOVING INTO THE
WESTERN LAKE WINNIPEG REGION. THE MAIN FORECAST CONCERNS INCLUDE
TIMING THE END OF PRECIP CHANCES THIS EVENING...AND SMALL PRECIP
CHANCE TOMORROW AFTERNOON.
TONIGHT...THE SHORTWAVE TROUGH OVER EASTERN WISCONSIN WILL EXIT
DURING THE EVENING AND SHOWERS WILL BE WEAKENING WITH LOSS OF
HEATING. THE LATEST SHORT RANGE GUIDANCE AND ESTIMATES FROM STORM
MOTION SUGGEST SHOWERS WILL LINGER INTO EARLY THIS EVENING OVER FAR
NE INTO CENTRAL WISCONSIN...SO WILL KEEP A SHOWER MENTION TROUGH MID
EVENING. CLOUDS MAY BE SLOWER TO DISSIPATE AS A WEAK FRONT WASHES
OUT ACROSS THE REGION. WILL SHOW PARTLY CLOUDY CONDITIONS BECOMING
MOSTLY CLEAR OVERNIGHT. LOW LEVEL MOISTURE IS NOT REALLY ALL THAT
DRY THOUGH...SO WITH CLEARING SKIES AND LIGHT WINDS...COULD SEE
PATCHY FOG DEVELOP LATE...ESPECIALLY OVER THE COLD SPOTS OF N-C
WISCONSIN. LOWS IN THE UPPER 40S NORTH TO MID 50S SOUTH.
TUESDAY...NORTHWEST FLOW WILL PREVAIL ALOFT WHILE WEAK HIGH PRESSURE
WILL BE AT THE SURFACE. A WEAK SHORTWAVE NOW OVER SOUTHERN MANITOBA
WILL SLOWLY PASS ACROSS THE STATE. PROGGED SOUNDINGS LOOK SIMILAR TO
TODAYS..WITH STEEP LOW LEVEL LAPSE RATES AND ML CAPES UP TO 500 J/KG
DEVELOPING IN THE AFTERNOON. WILL HAVE WEAK CONVERGENCE ALONG THE
LAKE BREEZE FOR A FOCUS MECHANISM SO LIKE HAVING A CHANCE OF SHOWERS
OVER NORTHERN WISCONSIN FOR THE AFTERNOON. WARMED HIGHS UP A COUPLE
DEGREES AND WENT MID 70S TO LOW 80S.
.LONG TERM...TUESDAY NIGHT THROUGH NEXT MONDAY. OTHER THAN TIMING
OF THE COLD FRONT LATE WEDNESDAY NIGHT OR THURSDAY THE MEDIUM
RANGE MODELS ARE IN PRETTY GOOD AGREEMENT INTO EARLY NEXT WEEK.
WEAK UPPER RIDGING SHOULD PROVIDE DRY WEATHER TUESDAY NIGHT AND
WEDNESDAY. UPPER DIFFLUENCE INCREASES WEDNESDAY NIGHT AS THE UPPER
TOUGH APPROACHES AND LOW LEVEL MOISTURE INCREASES AS WELL. SHOULD
GET A GOOD AREA OF SHOWERS AND THUNDERSTORMS MOVING INTO THE
WESTERN PART OF THE FORECAST AREA LATE WEDNESDAY NIGHT AND ACROSS
THE EAST THURSDAY MORNING. TIMING OF THE FRONT IS NOT IDEAL FOR
SEVERE THUNDERSTORMS SO THINK THAT THE SEVERE THREAT IS LOW.
UPPER FLOW BECOMES NORTHWEST FRIDAY AND SATURDAY AND A LARGE
SURFACE HIGH DROPS IN FROM THE NORTHERN PLAINS. WHILE IT SHOULD BE
GENERALLY DRY THERE IS A SMALL CHANCE OF MAINLY AFTERNOON SHOWERS
ACROSS THE NORTH IN THE COLD AND CYCLONIC FLOW. SURFACE HIGH
SHOULD BE RIGHT OVER THE AREA FRIDAY NIGHT AND WOULD NOT BE
SURPRISED TO SEE SOME FROST IN THE FAR NORTH.
&&
.AVIATION...A WEAK STORM SYSTEM WILL PASS ACROSS THE STATE THIS
AFTERNOON BEFORE EXITING THIS EVENING. A FEW SHOWERS ARE POSSIBLE
OVER NORTH-CENTRAL WISCONSIN THIS AFTERNOON...AND INCLUDED A TEMP
GROUP THIS AFTERNOON AT RHI. WILL SEE BKN VFR CIGS DEVELOP THIS
AFTERNOON AS INSTABILITY DEVELOPS WITH THE HEAT OF THE DAY...BUT
CLEARING WILL ENSUE ONCE THE SUN GOES DOWN. CALM WINDS AND CLEARING
SKIES WILL LEAD TO PATCHY FOG DEVELOPMENT EARLY TUESDAY MORNING.
VSBYS MAY FALL TO THE IFR RANGE WITHIN ANY GROUND FOG. VFR
CONDITIONS ON TUESDAY WITH CLOUDS BUILDING MIDDAY.
MPC
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MPC/RDM
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1140 PM CDT SUN AUG 12 2012
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND MONDAY
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SHORTWAVE
TROUGHING MOVING EAST OVER IOWA AND MINNESOTA AND SURFACE LOW
PRESSURE CENTERED OVER NE KANSAS EARLY THIS AFTERNOON. ARCING BAND
OF PRECIP STRETCHING FROM SOUTHERN MINNESOTA TO WESTERN ILLINOIS HAS
GENERALLY BEEN DECAYING AS IT MOVES INTO DRIER AIR OVER WISCONSIN.
A SECONDARY AND MORE POTENT BAND IS MOVING NE OVER NORTHEAST IOWA
WHILE ANOTHER AREA OF PRECIP EXISTS OVER EASTERN NORTH DAKOTA WITHIN
THE COMMA HEAD OF THE SHORTWAVE AND ALONG A CANADIAN COOL FRONT. AS
THE SHORTWAVE ENERGY MOVES EAST OVER THE STATE...PRECIP CHANCES ARE
THE MAIN FORECAST CONCERNS IN THE SHORT TERM.
TONIGHT...SHORTWAVE TROUGH OVER THE NORTHERN PLAINS WILL MOVE EAST
INTO THE STATE OF WISCONSIN TONIGHT. ASSOCIATED ELONGATED SURFACE
LOW WILL ALSO MOVE EAST INTO ILLINOIS. THE LATEST NAM AND ECMWF
SHOW 300K ISENTROPIC ASCENT AND FGEN WILL REMAIN OVER NORTHERN
ILLINOIS AND SOUTHERN WISCONSIN TONIGHT...WHERE THE LOW LEVEL
MOISTURE WILL ALSO BE THE MOST ABUNDANT. PROGGED SOUNDINGS AND
UPSTREAM OBS CONTINUE TO SHOW DRY WEDGES BELOW 700MB WHERE THE
ATMOSPHERE STRUGGLES TO SATURATE BELOW 10KFT. WILL STILL HAVE THE
MID-LEVEL WAVE MOVE OVERHEAD THOUGH...SO SPRINKLES OR LIGHT SHOWERS
CANNOT BE RULED OUT. BUT WILL PLACE THE HIGHEST PROBABILITY OF
SHOWERS OVER CENTRAL AND EAST-CENTRAL WISCONSIN...THOUGH THE
PROBABILITY WILL ONLY BE IN THE LOW CHANCE RANGE. A MOSTLY CLOUDY
NIGHT WITH LOWS IN THE MID 50S TO LOW 60S.
MONDAY...THE SHORTWAVE TROUGH WILL SLOWLY MOVE ACROSS CENTRAL AND
EASTERN WISCONSIN IN THE MORNING AND EASTERN WISCONSIN AND LAKE
MICHIGAN IN THE AFTERNOON. NOT QUITE AS BULLISH IN QPF AS THE SREF
OR THE GFS SINCE THINK THAT LOW LEVEL FORCING WILL RESIDE FARTHER
SOUTH. BUT STILL LOOKS LIKE THE BEST CHANCES OF PRECIP WILL OCCUR
IN THE MORNING WHEN EAST-CENTRAL WISCONSIN WILL BE ON THE NORTHERN
PERIPHERY OF THE DEEPER MOISTURE...AND THE COMMA HEAD OF THE
SHORTWAVE MOVES OVER NORTH-CENTRAL WISCONSIN. SOME INTERACTION WITH
DAYTIME INSTABILITY APPEARS POSSIBLE AS ML CAPES UP TO 400 J/KG WILL
BE POSSIBLE BY MIDDAY. WILL KEEP A CHANCE IN THE AFTERNOON TO
ACCOUNT FOR ANY DIURNAL INSTABILITY ACTIVITY. PLENTY OF CLOUD COVER
WILL KEEP HIGHS IN THE LOW TO MID 70S.
.LONG TERM...MONDAY NIGHT THROUGH NEXT SUNDAY. UPPER TROUGH WILL
EXIT THE AREA MONDAY NIGHT AND SCATTERED SHOWERS WILL END. THEN
MAINLY DRY NORTHWEST UPPER FLOW EXPECTED TUESDAY THROUGH
WEDNESDAY. THERE COULD BE ISOLATED OR WIDELY SCATTERED SHOWERS
TUESDAY AFTERNOON BUT LEFT THEM OUT OF THE FORECAST FOR NOW. A
SIGNIFICANT UPPER TROUGH WILL APPROACH THE REGION WEDNESDAY NIGHT
AND THURSDAY. THERE CONTINUES TO BE TIMING DIFFERENCES BETWEEN THE
MEDIUM RANGE MODELS SO DID NOT GO WITH LIKELY PROBABILITIES OF
PRECIPITATION AS THERE IS UNCERTAINTY AS TO WHICH PERIOD(S) RAIN
WILL FALL. EITHER WAY IT WILL BE MILDER AND A LITTLE MORE HUMID
WEDNESDAY AS WINDS BECOME SOUTH AND MOISTURE INCREASES. THE UPPER
TROUGH REALLY ESTABLISHES ITSELF ACROSS THE GREAT LAKES FRIDAY
THROUGH SUNDAY. WE MAY SEE THE FIRST PERIOD OF COOLER THAN NORMAL
WEATHER THIS SUMMER THAT LASTS MORE THAN A DAY OR TWO. FROST LOOKS
POSSIBLE FRIDAY NIGHT IN NORTHERN WISCONSIN WITH BIG SURFACE HIGH
OVERHEAD AND LOW DEW POINTS. MENTIONED THIS POSSIBILITY IN THE
HAZARDOUS WEATHER OUTLOOK.
&&
.AVIATION...A LOW PRESSURE SYSTEM WILL TRACK WELL SOUTH OF THE REGION
LATE TONIGHT INTO MONDAY...TAKING MOST OF THE SHOWER ACTIVITY SOUTH
OF THE FORECAST AREA. SOME LIGHT SHOWER ACTIVITY WILL BRUSH PARTS
OF C/EC WI LATE TONIGHT INTO EARLY MONDAY. AN UPPER LEVEL TROF AND
WEAK SFC COLD FRONT WILL PASS THROUGH THE AREA ON MONDAY...AND
SHOULD BRING SCATTERED SHOWERS TO THE ENTIRE REGION. A FEW TSTMS
ARE POSSIBLE DURING THE AFTERNOON...ESPECIALLY OVER NORTHERN WI...
ALTHOUGH THE PROBABILITY IS TOO LOW TO ADD TO THE RHI TAF AT THIS
TIME. EXPECT SOME CLEARING TO OCCUR BY MONDAY EVG. VFR CONDITIONS
SHOULD PREVAIL THROUGH MOST OF THE TAF PERIOD.
KIECKBUSCH
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NEW YORK NY
530 AM EDT WED AUG 15 2012
.SYNOPSIS...
A WEAK LOW PRESSURE TROUGH WILL LINGER OVER THE REGION TODAY AND
HELP TRIGGER SCATTERED TO NUMEROUS THUNDERSTORMS INTO THIS
EVENING. THE TROUGH WILL THEN PASS TO THE EAST LATE WEDNESDAY
NIGHT. WEAK HIGH PRESSURE WILL BUILD ACROSS THURSDAY THROUGH
FRIDAY...THEN A SLOW MOVING COLD FRONT WILL MOVE ACROSS FRIDAY
NIGHT THROUGH SATURDAY. LOW PRESSURE DEVELOPING ALONG THE FRONT
WILL PASS THROUGH THE REGION OVER THE WEEKEND. HIGH PRESSURE WILL
THEN RETURN FOR THE NEW WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ONGOING CONVECTION ACROSS ERN LONG ISLAND AND NOW OVER THE LOWER
HUDSON VALLEY AND SW CT SHOULD PROGRESS SLOWLY E-NE THIS MORNING
AS A WEAK SFC TROUGH ENTERS AND REMAINS OVER THE REGION
TODAY...FUELED BY MLCAPE 1000-2000 J/KG. WINDS HAVE LOCALLY BACKED
TO THE SE ACROSS SW CT AS OF 08Z AS WAS THE CASE EARLIER TONIGHT
OVER LONG ISLAND...INCREASING BULK SHEAR AS WELL AS 0-1 KM SREH TO
OVER 100 M2/S2. THINK THIS SHOULD MAINLY PROMOTE SUSTAINED
UPDRAFTS WITH ENHANCED HEAVY RAIN POTENTIAL...BUT CANNOT TOTALLY
RULE OUT STRONG WINDS VIA PRECIP LOADING OF ANY QUICKLY COLLAPSING
STRONGER CELLS...MAYBE EVEN AN ISOLD SHORT-LIVED TORNADO.
THERE MAY BE A SHORT BREAK IN THE ACTION BEFORE TSTMS FIRE UP
AGAIN THIS AFTERNOON...BECOMING NUMEROUS IN COVERAGE ESPECIALLY
LATE THIS AFTERNOON AND THIS EVENING AS A VIGOROUS MID LEVEL
SHORTWAVE TROUGH APPROACHES FROM THE OH VALLEY AND PHASES WITH
ANOTHER APPROACHING UPPER TROUGH TO ITS NORTH. CONCUR WITH SPC DAY
1 SLIGHT RISK FOR ENTIRE CWA...WITH PULSE/MULTICELL CONVECTION
CAPABLE OF PRODUCING DAMAGING WIND GUSTS...ALSO FREQUENT
LIGHTNING...AND HEAVY RAIN AS PW REMAINS NEAR 1.75 INCHES AND
CORFIDI VECTORS INDICATE POTENTIAL FOR BACK-BUILDING OF STORM
CLUSTERS AND TRAINING OF CELLS.
CONVECTIVE THREAT SHOULD SHIFT TO THE EAST AND WANE LATER
TONIGHT...WITH PATCHY FOG POSSIBLE WHERE HEAVY RAIN HAS FALLEN.
HIGH TEMPS TODAY WILL BE IN THE 80S...WITH LOWS TONIGHT IN THE 60S
TO LOWER 70S...CLOSE TO A 00Z MAV/MET GUIDANCE BLEND.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
LAST OF THE CONVECTION MAY STILL BE CLEARING ERN SECTIONS EARLY IN
THE MORNING PER SLOWER 00Z AS COMPARED TO THE GFS. OTHERWISE...EXPECT
DRY CONDITIONS...WITH PLENTY OF SUNSHINE AND ONLY SOME FAIR WX
CU...WITH SLIGHTLY WARMER TEMPS IN THE MID AND UPPER 80S...BUT
WITH LOWER DEWPOINTS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
HIGH PRES OVER THE AREA DEPARTS FRIDAY MORNING...THEN A SLOW MOVING
COLD FRONT APPROACHES FROM THE WEST. SHOWERS AND THUNDERSTORMS AHEAD
OF THE FRONT WILL ENTER THE REGION FROM WEST TO EAST DURING THE DAY
ON FRIDAY. SHOWERS AND THUNDERSTORMS WILL BECOME MORE WIDESPREAD
OVER THE AREA FRIDAY NIGHT INTO SATURDAY AS THE COLD FRONT MOVES
CLOSER AND HAS UPPER LEVEL SUPPORT FROM AN H5 TROUGH AND MID-LEVEL
SHORTWAVES.
THEREAFTER...LOW CONFIDENCE FORECAST FOR THE WEEKEND AS THE MODELS
HAVE DIFFERENT SOLUTIONS. LOW PRES FORMS OVER THE DELMARVA SOMETIME
EARLY SATURDAY...THEN TRACKS NORTHEAST ALONG THE FRONT. THE GFS
BRINGS THE FRONT THROUGH THE REGION MUCH QUICKER THAN THE ECMWF...
AND KEEPS THE LOW EAST OF THE REGION. THE ECMWF BRINGS THE LOW OVER
THE AREA DURING THE DAY SATURDAY INTO SATURDAY NIGHT. PRECIPITATION
WOULD THEN LINGER INTO SUNDAY AS H5 TROUGH FOLLOWS THROUGH THE
REGION. WILL CARRY CHANCE POPS FOR MOST OF THE WEEKEND...BUT THIS IS
SUBJECT TO ADJUSTMENTS.
LOCALLY HEAVY RAIN IS POSSIBLE WITH PWATS AROUND 2" STARTING ON
FRIDAY.
HIGH PRES BEGINS TO BUILD INTO THE REGION STARTING ON SUNDAY. PRECIP
TAPERS OFF FROM WEST TO EAST...THOUGH A FEW LINGERING SHOWERS AND
POSSIBLE THUNDERSTORMS ARE POSSIBLE THROUGH MONDAY AS UPPER TROUGH
AND H5 SHORTWAVES TRACK ACROSS THE REGION. DRY WEATHER EXPECTED BY
FRIDAY WITH HIGH PRES BUILDING EAST.
SOUTHERLY FLOW ON FRIDAY WILL PUSH TEMPS INTO THE MID-UPPER 80S AND
MAY COME CLOSE TO 90 IN/AROUND NYC. OTHERWISE...HIGHS WILL BE IN THE
UPPER 70S TO LOWER 80S DURING THE PERIOD...WHICH IS RIGHT AROUND
NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
UPPER LEVEL DISTURBANCE CURRENTLY MOVING THROUGH THE REGION. WEAK
LOW PRES OVER NJ WILL SLOWLY LIFT TOWARDS NYC TODAY AND THEN PASS
OVER OR JUST SOUTH OF THE AREA TONIGHT.
SCT TSTMS WILL LIFT NE EARLY THIS MORNING. COULD SEE ADDITIONAL
CELLS DEVELOP THROUGH 12Z MAINLY OVER EASTERN TERMINALS WHICH
WOULD WARRANT QUICK AMENDMENTS. LATEST HRRR KEEPS STORMS E OF NYC
THIS MORNING AND THEN FIRES THEM UP AGAIN THIS AFTN WITH
INCREASING INSTABILITY WHICH FITS CURRENT THINKING.
GENERALLY VFR CONDS THROUGH THE PERIOD...ALTHOUGH SCT V BKN MVFR
CIGS POSSIBLE EARLY. MVFR TO LOCALLY IFR CONDS IN SHRA/TSTM
ACTIVITY THIS AFTN AND EVE. BEST TIMING FOR CONVECTION WILL BE
BETWEEN 17Z AND 21Z ACROSS WESTERN TERMINALS AND 20Z TO 00Z AT
EASTERN TERMINALS. SOME OF THIS ACTIVITY MAY LINGER BEYOND THIS
TIME FRAME AS THE LOW AND UPPER LEVEL TROUGH SLOWLY PASSES THROUGH
BUT CONFIDENCE IS LOW ATTM SO HAVE ONLY KEPT -SHRA IN THE
FORECAST.
WINDS ARE EXPECTED TO BACK TO THE SE THIS MORNING AND REMAIN BLO
10 KT THROUGH THE FORECAST PERIOD. WITH THE SFC LOW PRES NEAR THE
AREA TODAY...DIRECTIONS BECOME TROUBLESOME AND HIGHLY UNCERTAIN AFT
18Z.
...NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT: HTTP://WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: LOW CONFIDENCE IN WIND FORECAST AFT 18Z.
TSTMS MAY CONTINUE INTO THE EVE.
KLGA FCSTER COMMENTS: LOW CONFIDENCE IN WIND FORECAST AFT 18Z.
TSTMS MAY CONTINUE INTO THE EVE.
KEWR FCSTER COMMENTS: LOW CONFIDENCE IN WIND FORECAST AFT 18Z.
TSTMS MAY CONTINUE INTO THE EVE.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: LOW CONFIDENCE IN WIND FORECAST AFT 18Z.
TSTMS MAY CONTINUE INTO THE EVE.
KHPN FCSTER COMMENTS: TSTMS MAY CONTINUE INTO THE EVE.
KISP FCSTER COMMENTS: TSTMS MAY CONTINUE INTO THE EVE.
OUTLOOK FOR 06Z THURSDAY THROUGH SATURDAY...
.WED NIGHT...MVFR CONDITIONS WITH ANY SHRA/TSRA...MAINLY EASTERN
TERMINALS. PATCHY MVFR FOG ALSO POSSIBLE OUTSIDE OF NYC TERMINALS.
.THU...VFR. NW FLOW.
.FRI...TSTMS (POSSIBLE LINE) LATE FRI AFTN INTO OVERNIGHT WITH
PASSAGE OF A COLD FRONT.
.SAT-SUN...VFR. N-NW FLOW.
&&
.MARINE...
PREVAILING SUB-SCA CONDS EXPECTED THROUGH THE WEEKEND.
THUNDERSTORMS TROUGH TONIGHT AND AGAIN FRIDAY AFTERNOON THROUGH
SUNDAY COULD RESULT IN LOCALLY REDUCED VSBY AND WIND GUSTS OVER
35 KT.
&&
.HYDROLOGY...
BASIN AVG QPF THROUGH WED NIGHT SHOULD RANGE FROM 3/4 TO 1 1/4
INCH...HIGHER OVER LONG ISLAND AND CT. LOCALLY HIGHER AMOUNTS OVER
2 INCHES ARE POSSIBLE. FLASH FLOOD THREAT IS LOW TO MODERATE...AND
MAY EVENTUALLY REQUIRE A SHORT FUSED WATCH FOR THIS AFTERNOON
AND EVENING.
A SLOW MOVING COLD FRONT WILL MOVE ACROSS FROM FRIDAY AFTERNOON
THROUGH EARLY SATURDAY...THEN LOW PRES MAY IMPACT THE REGION
SATURDAY THROUGH SUNDAY. PW VALUES NEAR 2 INCHES AHEAD OF THE FRONT
WILL BRING AN ELEVATED THREAT OF HEAVY RAIN...WHICH COULD RESULT IN
MINOR FLOODING IN SOME AREAS.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GOODMAN/MPS
NEAR TERM...GOODMAN
SHORT TERM...GOODMAN
LONG TERM...MPS
AVIATION...
MARINE...GOODMAN/MPS
HYDROLOGY...GOODMAN/MPS
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
102 AM EDT WED AUG 15 2012
.SYNOPSIS...
LOW PRESSURE AND A COMPLEX WEAK FRONTAL SYSTEM SPRAWLED FROM THE
MID ATLANTIC STATES TO OHIO WILL CROSS THE MID ATLANTIC COAST LATE
TODAY. HIGH PRESSURE SHOULD MOVE BACK IN BEHIND THE DEPARTING
SYSTEM THURSDAY. ANOTHER COLD FRONT SLOWLY MOVES THROUGH LATER ON
FRIDAY INTO SATURDAY BEFORE HIGH PRESSURE CAN POSSIBLY BUILD BACK
IN LATE SUNDAY AND MONDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE ACTIVITY ACROSS MOVING INTO THE LEHIGH VALLEY AND NORTHEAST
MARYLAND IS STARTING TO WANE AS THE IT IS NOW FUELED MAINLY BY IN
SITU INSTABILITY. THE BEST SHEAR WILL PASS SOUTH OF THE AREA
DURING THE NEXT THREE HOURS...AND MID LEVEL LAPSE RATES ARE
MARGINAL AT BEST. FOR NOW...THE MENTION OF HEAVY RAIN (AS THE
CONVECTION SITS IN AN AREA OF 1.70 INCH PRECIPITABLE
WATER)...GUSTY WINDS AND LIGHTNING WILL BE LEFT IN THE FORECAST
(THOUGH LOCALIZED FLOODING MAY BE THE BIGGEST THREAT.
THE LATEST HRRR WEAKENS THE ACTIVITY AS IT MOVES TO THE NORTHEAST...
INTO LESS UNSTABLE AIR. THE LOW LEVELS SHOULD TEND TO STABILIZE
AHEAD OF IT...SO THIS MAKES SOME SENSE. THE OVERNIGHT SHOWER AND
THUNDERSTORM FORECAST WILL BE REVISED A BIT TO FIT THE ABOVE
THINKING.
THE CLOUD COVER FORECAST WILL ALSO HAVE TO BE ADJUSTED TO ACCOUNT
FOR SOME STRATUS ACROSS PORTIONS OF WEST CENTRAL NEW JERSEY. IT IS
NOT CLEAR AT THIS POINT HOW WIDESPREAD THE STRATUS WILL GET...BUT
IT MAY END UP SPREADING INTO EASTERN PENNSYLVANIA DURING THE NEXT
THREE HOURS OR SO. THE STRATUS SHOULD TEND TO LESS THEN FOG
THREAT...BUT THIS MAY END UP BEING DICTATED BY WHERE THE RAIN
FALLS EARLY THIS MORNING IN A LIGHT BOUNDARY FLOW.
NO SIGNIFICANT CHANGES WERE MADE TO THE TEMPERATURE AND WIND
FORECASTS FOR THE REST OF THE NIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THIS EVENING/...
THE UPPER TROUGH WILL BE CROSSING THE AREA WED. MOISTURE WILL REMAIN
RATHER HIGH AND WITH THE FRONT AND WEAK LOW NEARBY...THERE REMAINS
THE CHC FOR SCATTERED SHOWERS/TSTMS. WE HAVE KEPT THE CHC FOR PRECIP
MOSTLY IN THE CHC RANGE FOR NOW. SPC HAS MOST OF OUR AREA IN A
GENERAL TSTM OUTLOOK...BUT SLGT CHC EXISTS OVER SRN DELAWARE. HIGH
TEMPERATURES WEDNESDAY WILL TOP OUT IN THE LOW 80S ACROSS THE NORTH
AND MID TO UPPER 80S ELSEWHERE.
MORE ML CAPE THAN TODAY AND IT LOOKS LIKE A LITTLE HIGHER TT BUT
SHEAR IS MARGINAL AT BEST.
&&
.LONG TERM /WEDNESDAY EVENING THROUGH TUESDAY/...
A DOWNWARD TREND IN SHOWERY ACTIVITY IS EXPECTED DURING THE
OVERNIGHT HOURS WEDNESDAY AS THE FINAL MID-LEVEL IMPULSE PULLS
THROUGH AND TO OUR NORTHEAST. WEAK MID-LEVEL RIDGING WILL BUILD IN
ALLOWING MID-LEVELS WINDS TO BECOME SOMEWHAT ZONAL OR SLIGHTLY
NORTHWEST ON THURSDAY AND FRIDAY. SURFACE HIGH PRESSURE WILL MOVE
ACROSS THE REGION ON THURSDAY INTO EARLY FRIDAY AND KEEP OUR
SENSIBLE WEATHER RATHER QUIET. SHOULD HAVE AMPLE SUNSHINE ON
THURSDAY TO ALLOW TEMPERATURES TO CLIMB BACK TO AROUND SEASONAL OR
SLIGHTLY ABOVE.
HIGH SLIDES OFF THE COAST EARLY ON FRIDAY WITH A RETURN FLOW SETTING
UP. MORE MOISTURE AND WARMER TEMPERATURES ARE ADVECTED BACK INTO THE
REGION JUST IN TIME FOR AN APPROACHING MID-LEVEL WAVE AND SURFACE
COLD FRONT TO MOVE THROUGH. COULD SEE A LEE SIDE TROUGH FORM AND
MOVE THROUGH OUR SOUTHERN ZONES DURING THE AFTERNOON HOURS AND WITH
AMPLE SURFACE BASED INSTABILITY CONVECTION IS LIKELY, ALTHOUGH THIS
ALL DEPENDENT ON THE TIMING OF THE AFOREMENTIONED COLD FRONT AND LEE
SIDE TROUGH. MODEL TIMING ON THE FRONTAL PASSAGE HAS NOT BEEN GOOD
WITH SOME BRINGING IT THROUGH FRIDAY EVENING AND SOME NOT CLEARING
THE REGION UNTIL SUNDAY MORNING. THOUGH THE FLOW IN THE MID-LEVELS
DOES NOT LOOK AS FORCEFUL AS IT DID YESTERDAY, WITH A MORE
MERIDIONAL REGIME IN PLACE, A SLOWER TIMING LOOKS MORE LIKELY. THIS
WOULD INTRODUCE HIGHER CHANCES OF SHOWERS AND THUNDERSTORMS BY
FRIDAY EVENING/NIGHT SPREADING INTO SATURDAY EVENING. ANOTHER WAVE
OF LOW PRESSURE FORMS ALONG THE FRONTAL BOUNDARY AND SLOWS ITS
EASTWARD MOVEMENT EVEN MORE. THAT BEING SAID DECIDED TO KEEP THE
CHANCE POPS IN FOR MUCH OF SATURDAY.
FINALLY WE SHOULD BE ABLE TO KICK THE FRONT FAR ENOUGH TO THE EAST
BY LATE SATURDAY OR SUNDAY MORNING AND DRY OUT. MID-LEVEL TROUGHING
WILL REMAIN ACROSS THE REGION FOR THE DURATION OF THE LONG TERM AND
THIS COULD KEEP US RATHER UNSETTLED FOR THE START OF THE NEW WORK
WEEK. LOOKS LIKE OUR NEXT SHOT AT SEEING PRECIPITATION IS ON TUESDAY
AS ANOTHER PIECE OF ENERGY IN THE MID-LEVELS DIVES INTO THE BASE OF
THE EAST COAST TROUGH AND THEN MOVES UP TO THE NORTHEAST WITHIN THE
SOUTHWEST FLOW ALOFT.
TEMPERATURES THROUGH THE LONG TERM WILL BE NEAR NORMAL TO SLIGHTLY
ABOVE NORMAL BY THE END OF THE WEEK. ONCE THE MID-LEVEL TROUGH
RE-ESTABLISHES ITSELF NEARBY AND THE FRONTAL SYSTEM CLOSE BY, WE
COULD SEE AMPLE CLOUD COVER ALLOWING FOR SLIGHTLY BELOW NORMAL
TEMPERATURES SATURDAY THROUGH TUESDAY.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
VARIABLE CONDITIONS AROUND THE AREA EARLY THIS MORNING. MAINLY VFR
ACROSS SOUTHEAST NEW JERSEY AND KILG...WHICH ARE SOUTH AND EAST OF
THE MAIN AREA OF RAIN AND THUNDER. MVFR CONDITIONS ACROSS THE KPHL
METRO AIRPORTS...WITH THUNDER NEAR KPH. MVFR TO LOCALLY IFR AT KRDG
AND KABE...WITH THUNDER AT BOTH LOCATIONS.
MVFR TO LOCALLY IFR CONDITIONS ARE EXPECTED ALONG THE PATH OF THE
THUNDERSTORMS EARLY THIS MORNING (THROUGH ABOUT 0900 UTC). THIS
INCLUDE KABE AND KRDG...BUT THE KPHL METRO AIRPORTS SHOULD REMAIN
SOUTH OF THAT AREA. STRATUS NEAR 1500 FEET IS EXPECTED AT KPNE AND
KTTN IN THE MOIST LOW LEVEL FLOW...BUT WHETHER KPHL GETS THIS LOW
(OR LOWER) IS STILL PROBLEMATIC.
THE STRATUS MAY AFFECT KMIV...BUT BOTH KMIV AND KACY WILL SEE A
PERIOD OF MVFR VISIBILITIES. MOST LOCATIONS SHOULD RETURN TO VFR
CONDITIONS AROUND 1400 UTC. AFTER THIS...A MAINLY VFR MID MORNING
TO EARLY AFTERNOON IS EXPECTED. AFTER THIS...THUNDERSTORMS ARE
EXPECTED AHEAD OF A SLOW MOVING COLD FRONT. FOR NOW...A PROB30 WAS
INCLUDED IN THE TERMINAL FORECASTS TO INDICATE THE POTENTIAL...AND
THIS WILL BE REVISED WITH THE 1200 UTC FORECASTS.
AFTER THE THUNDERSTORM THREAT ENDS (NEAR 0000 UTC)...MAINLY VFR
CONDITIONS ARE EXPECTED. MVFR VISIBILITIES ARE POSSIBLE AT THE
USUAL LOCATIONS AFTER 0600 UTC THURSDAY.
OUTLOOK...
THURSDAY AND THROUGH FRIDAY...MAINLY VFR WITH LIGHT WEST WINDS.
FRIDAY NIGHT THROUGH SATURDAY...ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS POSSIBLE. VFR CONDITIONS EXPECTED.
SATURDAY NIGHT THROUGH SUNDAY...VFR EXPECTED. COULD BE A FEW
LINGERING SHOWERS EARLY SATURDAY NIGHT.
&&
.MARINE...
NO SCA THROUGH WEDNESDAY. MAINLY S-SE WIND 10-15 KTS TONIGHT BECOME S-SW
WEDNESDAY AND THEN W LATE IN THE DAY. G WINDS NEAR ANY TSTMS.
OUTLOOK...
SUB-ADVISORY CONDITIONS ARE EXPECTED ACROSS THE WATERS
THROUGH THE WEEKEND. HIGH PRESSURE WILL BUILD IN ON THURSDAY
PROVIDING TRANQUIL CONDITIONS. WINDS TURN TO THE SOUTH ON FRIDAY
AND SEAS WILL BEGIN TO CLIMB TO 3 TO 4 FEET FOR A TIME DURING THE
AFTERNOON HOURS...DEPENDING ON HOW LONG WE TRULY KEEP THE
SOUTHERLY FETCH. ANOTHER FRONTAL SYSTEM TRIES TO ENTER FROM THE
WEST EARLY ON SATURDAY PROVIDING MORE SHOWERS AND THUNDERSTORMS.
THIS FRONT SHOULD THEN PUSH OFF TO THE EAST BY LATE IN THE DAY AND
WINDS TURN TOWARDS THE WEST-NORTHWEST.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...DRAG/HEAVENER
NEAR TERM...HAYES
SHORT TERM...DRAG/O`HARA
LONG TERM...HEAVENER
AVIATION...HAYES/HEAVENER
MARINE...DRAG/HEAVENER
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
431 AM CDT WED AUG 15 2012
.SYNOPSIS...
ISSUED AT 430 AM CDT WED AUG 15 2012
THE 00 UTC UPPER AIR OBJECTIVE ANALYSIS INDICATED A SPLIT FLOW
PATTERN AT 300 MB, FEATURING A SOUTHERN JET ACROSS THE SOUTHERN
PLAINS INTO THE MID MISSISSIPPI VALLEY AND A STRONGER JET SWINGING
THROUGH SOUTHWEST CANADA TOWARD THE NORTHERN PLAINS. THIS PATTERN
LEFT THE HIGH PLAINS REGION IN A BROAD WEAK NORTHWEST UPPER FLOW
PATTERN WITH WESTERN KANSAS ON THE THERMALLY DIRECT SUBSIDENT REGION
OF THE EXITING JET. THE 00 UTC KDDC SOUNDING INDICATED SHALLOW
MOISTURE BELOW 800 MB, BUT A VERY DRY LAYER ALOFT THROUGH THE COLUMN
WITH LARGE DEW POINT DEPRESSIONS. A LARGE AREA OF FOG HAD EXPANDED
FROM THE WESTERN OKLAHOMA INTO THE AREAS WEST OF HIGHWAY 283 NEAR
STATE LINE. THIS AREA OF FOG WAS SLOWLY EXPANDING NORTHWARD THOUGH
THE OVERNIGHT.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 430 AM CDT WED AUG 15 2012
FOG WILL BE A PROBLEM THIS MORNING. THE SURFACE LAYER OF MOISTURE IS
QUITE SHALLOW, AND JUST HOW DENSE AND WIDESPREAD THE FOG WILL BECOME
HAS NOT BEEN DETERMINED AT THIS TIME. THE HRRR CAPTURED THE INITIAL
DEVELOPMENT ACROSS CLARK-MEADE-FORD AND GRAY COUNTIES VERY WELL BUT
THE VISIBILITIES HAD BEEN SLOW TO BECOME DENSE. THE SHALLOW NATURE
OF THE MOISTURE MAY JUST PREVENT THAT TOO, HOWEVER, A WIDE AREA OF
DEW POINT DEPRESSIONS BELOW 3 DEGREES HAVE BEEN OBSERVED BETWEEN
HIGHWAYS 83 AND 283.
FOG SHOULD RAPIDLY DISSIPATE AFTER SUNRISE AS SOUTHWEST KANSAS IN
UNDER A CLEAR SKY. SURFACE WINDS WILL REMAIN SOUTHEASTERLY AND
LIGHT, BUT BEGIN TO GUST SLIGHTLY AS VERTICAL MIXING COMMENCES. WITH
MORE INSOLATION TODAY AND A SLIGHT MORE WARM ADVECTION, TEMPERATURES
THIS AFTERNOON SHOULD BE SEVERAL DEGREES WARMER ON AVERAGE THAN THE
PREVIOUS DAY. WIDESPREAD HIGHS IN THE UPPER 90S WITH POTENTIAL TO
TEST 100 DEGREES IS POSSIBLE.
A COLD FRONT WILL ENTER THE AREA TONIGHT, IN THE MID EVENING HOURS AS
DEPICTED BY THE NAM/WRF. THE MODEL APPEARS RELATIVELY DRY AT LEAST
INITIALLY WITH RESPECT TO CONVECTIVE DEVELOPMENT. SURFACE BASED
INSTABILITY IS WEAK TO MODERATE IN THE WARM SECTOR, AND GIVEN THE STEEP
MID LEVEL LAPSE RATES, THE MUCAPES ARE A BIT LARGER. THERE IS A
SUBTLE 700 MB WAVE RIGHT BEHIND THE BOUNDARY. THIS COULD BE THE
CATALYST TO SET OFF A FEW STORMS WITH THE SYSTEM, AS THE SURFACE
BASED POTENTIAL FOR THE FRONT DOESN`T APPEAR GREAT. WITH THIS IN
MIND, THUNDERSTORMS CHANCES WILL REMAIN IN THE ISOLATED CATEGORY AND
STRONG WIND GUSTS AND LIGHTNING APPEAR TO BE THE ONLY THREATS LATE
TONIGHT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 430 AM CDT WED AUG 15 2012
MODELS IN EXCELLENT AGREEMENT WITH A STRONG AND PROGRESSIVE
SHORTWAVE TROUGH MOVING INTO THE NORTHERN AND CENTRAL PLAINS ON
THURSDAY PUSHING A SIGNIFICANT COLD FRONT ACROSS THE REGION. THE
COLD FRONT IS FORECAST TO EXTEND FROM NORTHERN MISSOURI INTO EASTERN
KANSAS, NORTHERN OKLAHOMA, AND INTO THE WESTERN TEXAS PANHANDLE ON
THURSDAY MORNING THEN DROP SOUTH INTO THE SOUTHERN PLAINS DURING THE
AFTERNOON. A BROAD AREA OF COOLER HIGH PRESSURE IN ITS WAKE WILL
BRING A SIGNIFICANT COOL DOWN TO DAYTIME HIGHS INTO THE WEEKEND.
WILL CONTINUE WITH A 20 TO 30 POP ALONG THE COLD FRONT ON THURSDAY
MORNING MAINLY SOUTH OF A LINE FROM SAINT JOHN TO MEADE. SCATTERED
THUNDERSTORMS AND LIGHT SHOWERS MAY LINGER ACROSS THE SOUTHERN TIER
COUNTIES ALONG THE OKLAHOMA BORDER INTO THURSDAY NIGHT. NORTH WINDS
WILL GUST TO 30 MPH ON THURSDAY BEHIND THE COLD FRONT. A SECONDARY
VORT MAX ON THE BACK SIDE OF THE UPPER LOW COULD BRING IN ANOTHER
CHANCE FOR SHOWERS AND THUNDERSTORMS INTO FAR WESTERN KANSAS ON
FRIDAY THEN INTO MUCH OF SOUTHWEST AND SOUTH CENTRAL KANSAS ON
SATURDAY AND SATURDAY NIGHT. WILL MAINTAIN A 20 TO 30 POP FOR NOW.
THE LARGE UPPER TROUGH WILL THEN BEGIN TO MOVE EAST INTO THE EASTERN
CONUS FROM SUNDAY INTO EARLY NEXT WEEK WITH A WARMING TREND INTO THE
WESTERN HIGH PLAINS. THE MODELS SHOW ANOTHER CHANCE FOR
THUNDERSTORMS ON TUESDAY AS AN UPPER JET MOVES ACROSS THE PLAINS
ALONG WITH INCREASING LOW LEVEL MOISTURE AND WARM AIR ADVECTION.
OVERNIGHT LOWS WILL BE IN THE 50S FRIDAY AND SATURDAY MORNINGS THEN
SLOWLY WARMING INTO THE LOW TO MID 60S INTO EARLY NEXT WEEK. DAYTIME
HIGHS WILL WARM FROM AROUND 80 ON THURSDAY AND FRIDAY, THEN SLOWLY
WARM THROUGH THE MID TO UPPER 80S INTO MONDAY AND INTO THE LOWER 90S
BY TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 103 AM CDT WED AUG 15 2012
ONLY THIN PATCHY CIRRUS WILL BE STREAMING ACROSS WESTERN KANSAS FOR
THE REST OF THE EARLY MORNING. THE SURFACE DEW POINT DEPRESSIONS
ACROSS CENTRAL KANSAS ARE ABOUT 4-6 DEGREES AT THIS TIME, AND COULD
BECOME REDUCED BETWEEN 9 AND 12 UTC AS THE ATMOSPHERE RADIATIONALLY
COOLS. PATCHY FOG MAY DEVELOP IN THIS WEAKLY UPSLOPE E3NVIRONMENT,
AS THE HRRR AND NAM/WRF SURFACE VISIBILITY OUTPUT ARE ALREADY
HINTING AT. CONFIDENCE ON COVERAGE IS TOO LOW HOWEVER TO CARRY AS A
PREVAILING CONDITION. THE SURFACE WINDS WILL AGAIN BE LIGHT
SOUTHEAST THROUGH THE OVERNIGHT BEFORE TURNING SLIGHTLY MORE
SOUTHERLY AND GUSTING TO AROUND 20 KNOTS AT TIMES BETWEEN 18 AND 23
UTC.
&&
.FIRE WEATHER...
ISSUED AT 430 AM CDT WED AUG 15 2012
WINDS WILL BE LIGHT BUT GUSTING TO AROUND 20 KNOTS IN THE AFTERNOON
FROM THE SOUTHEAST. WARM TEMPERATURES AND DRY AIR WILL
DRIVE RELATIVE HUMIDITIES DOWN INTO THE 20 TO 30 PERCENT RANGE DURING
BETWEEN 3 AND 7 PM. A COLD FRONT WILL ENTER THE AREA THIS EVENING,
EFFECTIVELY TURNING WINDS TO THE NORTH THROUGH THE NIGHT, WITH
STRONGER NORTH WINDS EXPECTED BY THURSDAY .
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 97 66 81 53 / 10 30 10 10
GCK 98 64 80 53 / 10 30 10 10
EHA 97 64 81 55 / 10 30 20 20
LBL 98 66 83 54 / 10 30 20 20
HYS 97 65 79 53 / 10 30 10 10
P28 96 70 85 59 / 10 20 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RUSSELL
SHORT TERM...RUSSELL
LONG TERM...KRUSE
AVIATION...RUSSELL
FIRE WEATHER...RUSSELL
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
105 AM CDT WED AUG 15 2012
...UPDATED FOR AVIATION...
.SHORT TERM...(THIS EVENING THROUGH TOMORROW) ISSUED AT 223 PM
CDT TUE AUG 14 2012
TONIGHT RELATIVELY TRANQUIL WEATHER WILL BE IN STORE FOR THE AREA AS
SUBSIDENCE/MARGINAL LIFT REMAINS OVER THE AREA BEHIND THE EXITING
STORM SYSTEM FROM LAST NIGHT AND THIS MORNING. THERE MAY BE SOME
PATCHY FOG DEVELOP OVER SOME OF THE AREA DUE TO THE COOL
TEMPERATURES AND HIGH DEW POINTS. LOWS WILL BE SIMILAR TO LAST
NIGHT...WITH TEMPERATURES DROPPING INTO THE UPPER 50S AND LOW 60S.
WEDNESDAY SOUTH WINDS WILL INCREASE AHEAD OF A COLD FRONT THAT WILL
MOVE THROUGH DURING THE EVENING. THE BREEZY SOUTH WINDS AND A WARM
FRONT WILL HELP WARM TEMPERATURES TO NEAR 100 DEGREES.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 257 PM CDT TUE AUG 14 2012
MAIN FORECAST CONCERN WILL BE CHANCES FOR PRECIP. ACCOMPANYING THE
COLD FRONT WEDNESDAY NIGHT.
LATE WEDNESDAY EVENING A COLD FRONT WILL ENTER PORTIONS OF WEST
CENTRAL KANSAS. THE LAST MODEL RUNS ARE IN FAIRLY GOOD AGREEMENT
WITH THE TIMING OF THE FRONT...MOVING IT INTO OKLAHOMA BY THE EARLY
MORNING. MODELS SHOW SOME LIFT AHEAD OF THE FRONT DURING THE EARLY
EVENING...SO KEPT THE PRECIP. CHANCES CONFINED TO THE FAR NORTH. AM
THINKING THE PRECIPITATION WILL BE MAINLY TIED TO THE FRONT WHERE
THE BEST LIFT AND INSTABILITY WILL BE. AS SUCH KEPT THE BEST
CHANCES FOR PRECIPITATION OVER THE FAR NORTH UNTIL THE OVERNIGHT
HOURS WHEN THE FRONT MOVES FURTHER SOUTH. AS THE FRONT MOVES
FURTHER SOUTH THE LIFT DECLINES DUE TO THE FRONT MOVING FURTHER FROM
THE UPPER LEVEL SHORT WAVE TROUGH THAT WILL MOVE TO THE SOUTHEAST.
WITH 0-6KM SHEAR AROUND 20KTS AM NOT ANTICIPATING ANY SEVERE WEATHER
THUNDERSTORMS...HOWEVER STRONG TO SEVERE WIND GUSTS DURING THE
EVENING ARE LIKELY WITH ANY STORM THAT DEVELOPS DUE TO THE HIGH
CLOUD BASES.
THURSDAY THE FRONT WILL MOVE INTO OKLAHOMA DURING THE EARLY MORNING
HOURS. BEHIND THE FRONT WINDS WILL STRENGTHEN DUE TO THE TIGHT
PRESSURE GRADIENT BEHIND THE FRONT AND THE 30-35KT 850MB WINDS
MIXING TO THE GROUND. THE WINDS WILL DECLINE THROUGH THE DAY AS THE
FRONT MOVES FURTHER SOUTH.
THURSDAY EVENING THE MODELS SHOW SOME LIFT JUST BEHIND THE FRONT
NEAR THE OKLAHOMA-KANSAS BORDER...SO INCLUDED SOME SLIGHT CHANCES
FOR THE EVENING IN THE FAR SOUTH.
FOR THE FRIDAY THROUGH TUESDAY PERIOD NUMEROUS WEATHER DISTURBANCES
MOVE THROUGH THE NORTHWEST FLOW OVER WESTERN KANSAS...BRINGING
CHANCES FOR PRECIPITATION NEARLY EVERYDAY. MODELS SEEM TO AGREE WITH
THE BEST CHANCES FOR PRECIPITATION DURING THE WEEKEND AS THE AXIS
FROM A LONG WAVE TROUGH OVER THE GREAT LAKES MOVES ACROSS THE
CENTRAL PLAINS. TEMPERATURES FOR THE PERIOD WILL BE COOLEST ON
FRIDAY BEHIND THE COLD FRONT...THEN GRADUALLY WARM THROUGH THE
BEGINNING OF NEXT WEEK AS THE UPPER LEVEL RIDGE OVER THE GREAT
BASIN BUILDS EASTWARD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 103 AM CDT WED AUG 15 2012
ONLY THIN PATCHY CIRRUS WILL BE STREAMING ACROSS WESTERN KANSAS FOR
THE REST OF THE EARLY MORNING. THE SURFACE DEW POINT DEPRESSIONS
ACROSS CENTRAL KANSAS ARE ABOUT 4-6 DEGREES AT THIS TIME, AND COULD
BECOME REDUCED BETWEEN 9 AND 12 UTC AS THE ATMOSPHERE RADIATIONALLY
COOLS. PATCHY FOG MAY DEVELOP IN THIS WEAKLY UPSLOPE E3NVIRONMENT,
AS THE HRRR AND NAM/WRF SURFACE VISIBILITY OUTPUT ARE ALREADY
HINTING AT. CONFIDENCE ON COVERAGE IS TOO LOW HOWEVER TO CARRY AS A
PREVAILING CONDITION. THE SURFACE WINDS WILL AGAIN BE LIGHT
SOUTHEAST THROUGH THE OVERNIGHT BEFORE TURNING SLIGHTLY MORE
SOUTHERLY AND GUSTING TO AROUND 20 KNOTS AT TIMES BETWEEN 18 AND 23
UTC.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 97 66 83 57 / 10 30 10 10
GCK 98 64 82 57 / 10 30 10 10
EHA 97 64 82 58 / 10 30 20 30
LBL 98 66 84 58 / 10 30 20 20
HYS 97 65 80 56 / 10 30 10 10
P28 96 70 87 60 / 10 20 30 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JTL
LONG TERM...JTL
AVIATION...RUSSELL
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
113 AM EDT WED AUG 15 2012
.SYNOPSIS...
A WEAK WARM FRONT WILL LIFT ACROSS THE AREA TONIGHT. AT THE SAME
TIME...LOW PRESSURE WILL CONTINUE TO DEVELOP OVER THE DELMARVA
PENINSULA. SHOWERS AND THUNDERSTORMS WILL BE LIKELY ON WEDNESDAY.
THIS WILL WILL VERY GRADUALLY LIFT NORTHEASTWARD ON
WEDNESDAY...AND MOVE TO A POSITION NEAR THE SOUTHERN TIP OF NOVA
SCOTIA LATE THURSDAY. A COLD FRONT WILL THEN PUSH ACROSS THE
REGION FRIDAY AFTERNOON OR EVENING. WEAK LOW PRESSURE MAY DEVELOP
JUST OFFSHORE ALONG THIS FRONT OVER THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
.UPDATE...
EXPANDED POPS A BIT TOWARDS PORTSMOUTH AND THE COASTAL WATERS
WHERE SOME SHOWERS HAVE POPPED UP. CONVECTION IS DEVELOPING OVER
SOUTHERN NH AND THE LATEST NAM RUN HAS A GOOD HANDLE ON THIS.
ALSO ADDED ISOLATED THUNDER AS APPROACHING 500MB TEMPS AROUND -12C
SHOULD CONTINUE TO SUPPORT CHARGE SEPARATION.
&&
PREVIOUS DISCUSSION...HAVE UPPED POP ACROSS SWRN ZONES OF THE CWA
BASED ON RADAR TRENDS. AS EXPECTED THE MID LVL WARM FNT IS
PUSHING NWD INTO THE CWA. THIS WAA IS LEADING TO ISOLD SHRA ACROSS
SULLIVAN AND GRAFTON COUNTIES ATTM. THIS ACTIVITY WILL CONTINUE TO
LIFT INTO THE CWA...AS MORE ORGANIZED CONVECTION WORKS IN FROM THE
W EARLY THIS MORNING. THE LATEST HRRR EVOLUTION LOOKS TO BE A GOOD
STARTING POINT...BUT TIMING APPEARS TO BE A LITTLE SLOW IN THE
MODEL. THE FCST MAINTAINS A CLOSER ARRIVAL TO MIDNIGHT THAN TO
12Z.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 AM THURSDAY/...
SHORT WAVE TROUGH WILL CONTINUE TO APPROACH ON WEDNESDAY WHILE LOW
LEVEL MOISTURE INCREASES. 500MB TEMPS WILL COOL TO BETWEEN -10C
AND -12C AND SHOULD RESULT IN SOME MODEST INSTABILITY STARTING
EARLY IN THE DAY WITH LITTLE IN THE WAY OF CAPPING. THEREFORE...WE
EXPECT CONVECTIVE SHOWERS TO DEVELOP DURING THE MORNING AWAY FROM
THE COAST...WITH NUMEROUS SHOWERS AND THUNDERSTORMS PRETTY MUCH
EVERYWHERE BY EARLY AFTERNOON. FLOW ALOFT IS WEAK AND MBE VECTORS
ARE SHORT. THEREFORE...SHOULD BE SOME SLOW MOVING STORMS WITH THE
ATTENDANT THREAT FOR LOCALLY BRIEF TORRENTIAL DOWNPOURS. GIVEN THE
LACK OF DEEP LAYER SHEAR...THE THREAT FOR SEVERE WIND AND/OR HAIL
APPEARS QUITE LOW AT THIS TIME.
AS THE UPPER LEVEL TROUGH AMPLIFIES AND SWINGS OVER THE REGION
WEDNESDAY NIGHT...THE CHANCE FOR SHOWERS ALONG WITH A FEW
THUNDERSTORMS WILL BE QUITE HIGH. LIKELY POPS FOR NOW...BUT MAY
NEED CATEGORICAL EVENTUALLY.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
UPPER LEVEL TROUGH MAY TRY TO CLOSE OFF OVERHEAD FOR A TIME ON
THURSDAY...AND THIS MAY MEAN SHOWERS FOR A GOOD PART OF THE DAY.
BEST CHANCE FOR WIDESPREAD PRECIP WILL BE IN THE MORNING. MAY NEED
TO CONSIDER RAISING POPS FOR MUCH OF THE AREA...HOWEVER.
RETURN FLOW AHEAD OF ANOTHER APPROACHING FRONT WILL PRODUCE WARM
AND MUGGY CONDITIONS ON FRIDAY. THE COLD FRONT WILL MOVE ACROSS
THE CWA DURING THE EVENING HOURS ON FRIDAY. IF THE FRONT SPEEDS UP
A LITTLE BIT THEN WE COULD SEE SOME STRONGER THUNDERSTORMS AS MAX
INSTABILITY WOULD COINCIDE WITH PEAK DIURNAL HEATING. COOLER AND
DRIER CONDITIONS WILL FOLLOW THE FRONT ON SATURDAY AND SUNDAY.
EXPECT TEMPERATURES TO RETURN TO NEAR NORMAL AND DEWPOINTS WILL
FALL UNDER NORTHWESTERLY FLOW.
BROAD UPPER LEVEL TROUGH OVER THE MIDDLE OF THE COUNTRY ON MONDAY
AND TUESDAY WILL PUT MAINE AND NEW HAMPSHIRE UNDER SOUTHWESTERLY
FLOW ALOFT. THIS WILL LIKELY PRODUCE UNSETTLED CONDITIONS AS WE
HEAD INTO THE EARLY PART OF THE WORK WEEK.
&&
.AVIATION /05Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM /THROUGH WEDNESDAY NIGHT/...LOCAL MVFR IN FOG OR PATCHY
STRATUS OVERNIGHT...BUT THE BULK OF THE NIGHT LOOKS TO BE VFR. ON
WEDNESDAY...SHOWERS AND THUNDERSTORMS SHOULD DEVELOP BETWEEN 15Z
AND 18Z...PERHAPS A TAD LATER ON THE COAST. LOCAL IFR CONDITIONS
EXPECTED WITH THOSE. SAME GOES FOR WED NIGHT.
LONG TERM /THURSDAY MORNING THROUGH SUNDAY/...MVFR/IFR CONDITIONS
IN RAIN AND FOG AS COLD FRONT MOVES THROUGH THE REGION WILL
IMPROVE TO VFR LATE THURSDAY MORNING. ANOTHER FRONTAL BOUNDARY
WILL BRING CONDITIONS DOWN TO MVFR/IFR AGAIN LATE FRIDAY BEFORE
HIGH PRESSURE BRINGS VFR CONDITIONS BACK FOR SATURDAY AND SUNDAY.
&&
.MARINE...
SHORT TERM /THROUGH WEDNESDAY/...WIND AND WAVES TO REMAIN BELOW
SCA LEVEL. VSBY RESTRICTIONS POSSIBLE TONIGHT AND WEDNESDAY MAINLY
IN FOG AND HAZE. VSBY RESTRICTIONS POSSIBLE IN RAIN WEDNESDAY
NIGHT AND THURSDAY.
LONG TERM...NO FLAGS EXPECTED. EXPECT SOME LINGERING FOG AND
SHOWERS THURSDAY UNTIL FRONTAL BOUNDARY MOVES NORTH AND EAST OF
THE REGION LATE DAY. OTHERWISE...NO ISSUES NOTED.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
UPDATE...HANES
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
129 AM EDT WED AUG 15 2012
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 359 PM EDT TUE AUG 14 2012
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NW FLOW OVER THE
UPR GRT LKS BTWN TROF CENTERED NEAR HUDSON BAY AND UPR RDG JUST OFF
THE CA COAST. STRONGER SHRTWV RESPONSIBLE FOR YDAYS SHRA IS OVER
LOWER MI AND MOVING INTO SE ONTARIO. ANOTHER WEAKER DISTURBANCE
ROTATING ARND THE ONTARIO VORTEX IS PRESENT JUST N OF THE MN/ONTARIO
BORDER AND HEADING ESEWD. 12Z INL/GRB RAOBS SHOW MODEST LLVL MSTR
CONFINED BLO INVRN ARND H7 AND VERY DRY AIR IN THE MID/UPR LVLS.
SINCE THE SHRTWV JUST N OF THE BORDER AND ACCOMPANYING H3 JET MAX
ARE ON TRACK TO STAY N OF THE CWA WITH ACCOMPANYING H5 CAD/DPVA/
DEEP LYR QVECTOR CNVGC JUST BRUSHING THE NRN TIER...LATEST NAM/RUC
FCST SDNGS HINT MID LVL INVRN/DRY AIR WL REMAIN IN PLACE. BUT WITH
THE LLVL MSTR/SFC DEWPTS AS HI AS 55 TO 60 OVER THE E THAT IS
CAUSING SOME CU TO DVLP AS THE SFC WARMS TO THE CONVECTIVE TEMP IN
THE LO 70S...A FEW SHRA HAVE DVLPD OVER THE E ALONG LK BREEZE BNDRYS
WHERE COOLING AT H5 IS A BIT MORE PRONOUNCED AND WHERE THE 12Z CNDN
MODEL HINTED SHRA WOULD BE MOST LIKELY TO FORM. BEHIND THIS
DISTURBANCE...A SHRTWV RDG/ SFC HI IS PRESENT OVER MANITOBA/FAR NW
ONTARIO...BRINGING TRANQUIL WX TO THIS AREA IN CONCERT WITH FAIRLY
DRY AIRMASS DEPICTED BY THE 12Z THE PAS MANITOBA RAOB NEAR LK
WINNIPEG. ANOTHER POTENT SHRTWV IS DIGGING SEWD THRU BRITISH
COLUMBIA.
LATE THIS AFTN...MAINTAINED LO CHC POPS IN THE AREAS OVER THE
CENTRAL AND E MOST LIKELY TO BE IMPACTED BY THE LK BREEZE CNVGC.
HOWEVER...WITH WARM MID LVLS AND ENVIRONMENTAL LAPSE RATES NEAR
MOIST ADIABATIC...ANY SHRA/TS WL BE ISOLD/SCT AND ON THE RELATIVELY
WEAK SIDE WITH DEEP LYR SHEAR NO HIER THAN 25-30 KTS.
TNGT...WITH LOSS OF DAYTIME HEATING AND APRCH OF SHRTWV RDG/DNVA/
DEEP LYR QVECTOR DVGC...EXPECT ANY SHRA/TS TO DIMINISH DURING THE
EVNG. WITH LGT WINDS/DRYING ALF ASSOCIATED WITH INCOMING HI PRES...
EXPECT ENUF DIURNAL COOLING TO SUPPORT GOING PATCHY FOG FCST OVER
THE INTERIOR E HALF...WHERE SFC DEWPTS ARE HIER THIS AFTN.
WED...HI PRES OVER UPR MI IN THE MRNG IS PROGGED TO DRIFT TO THE E
THRU THE DAY AS SHRTWV RDG MOVES TO THE E IN ADVANCE OF DISTURBANCE
NOW IN BRITISH COLUMBIA AND THAT IS FCST TO REACH THE NRN PLAINS BY
00Z THU. ALTHOUGH THE SHARPEST DPVA/DEEP LYR QVECTOR CNVGC IN
ADVANCE OF THIS DISTURBANCE IS FCST TO REMAIN TO THE W THRU 00Z...
THE BULK OF THE NUMERICAL GUIDANCE GENERATES SOME GENERALLY LGT PCPN
OVER THE W HALF IN THE AFTN. HOWEVER...SINCE THE NAM/GFS FCST SDNGS
SHOW WARM MID LVL TEMPS IN THE ABSENCE OF ANY DYNAMIC FORCING AND
HINT THAT LLVL MSTR RETURN IN ADVANCE OF THE SHRTWV WL BE MARGINAL
DUE TO DRYNESS OF AIRMASS IN THE NRN PLAINS THIS AFTN...OPTED TO
RESTRICT POPS TO JUST THE FAR W LATER IN THE DAY WHERE THE GFS/NAM
SHOW HIER H85 DEWPTS NEAR 12C RETURNING TOWARD 00Z IN THE
STRENGTHENING SSW FLOW AHEAD OF THIS DISTURBANCE. WITH H85 TEMPS
RECOVERING TO ABOUT 13C OVER THE E TO 17C OVER THE W BY LATER IN THE
DAY...EXPECT HI TEMPS TO REACH THE 80S AT MOST PLACES AWAY FM LK MI
MODERATION.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 359 PM EDT TUE AUG 14 2012
WEDNESDAY NIGHT THROUGH THURSDAY...UPPER LEVEL LOW AND ASSOCIATED
SURFACE LOW OVER WESTERN ONTARIO WILL SHIFT SLOWLY EAST THROUGHOUT
THIS TIME PERIOD. AS THIS HAPPENS THE LOW WILL SWEEP A COLD FRONT
ACROSS THE AREA WEDNESDAY NIGHT THROUGH THURSDAY AS SHOWN BY
PLOTTING SURFACE WINDS/MSLP/H850 THETA E. MODELS ARE FAIRLY SIMILAR
ON TIMING AS THE FRONT IS EXPECTED TO FIRST MOVE INTO THE WESTERN
PORTION OF THE UPPER PENINSULA AROUND 06Z THURSDAY AND THEN REACHING
THE EASTERN UPPER PENINSULA AROUND 18Z THURSDAY. THE GFS IS SLIGHTLY
FASTER THAN THE EC/NAM AT BRINGING THE FRONT THROUGH THE
REGION...WITH THE PRECIP SHOWN TO START A COUPLE OF HOURS EARLIER.
THE 06Z RUN OF THE GFS IS SHOWING A TREND TOWARD SLOWING THE
PRECIPITATION...WHICH WOULD BE MORE IN LINE WITH THE PREVIOUSLY
MENTIONED MODELS. HAVE LEANED MORE TOWARD THE EC FOR TIMING. THE
BEST CHANCE FOR HEAVIER PRECIPITATION ALONG WITH THUNDERSTORMS WILL
BE ALONG AND JUST AHEAD OF THE COLD FRONT WEDNESDAY NIGHT INTO
THURSDAY MORNING AS THIS IS BEST COLLOCATION OF DEEPER MOISTURE AND
FORCING...AS SHOWN BY OVERLAYING 1000-500MB RH AND 500-300MB QDIV.
CAPE VALUES AHEAD OF THE SYSTEM ARE EXPECTED TO TOP OUT AROUND
500-600 J/KG OVER THE WESTERN U.P. DURING THE EVENING AND SLOWLY
DECREASE AS THE SYSTEM MOVES EAST LATER IN THE NIGHT. CAPE IN THE
HAIL GROWTH ZONE IS EXPECTED TO BE AROUND 100-200 J/KG. AS THE FRONT
REACHES THE U.P. DEEP LAYER SHEAR VALUES ARE EXPECTED TO BE PARALLEL
TO THE FRONT AT 30 TO 35 KNOTS ALONG AND JUST AHEAD OF
IT...INCREASING TO AROUND 50 KNOTS BEHIND THE FRONT. WITH THAT BEING
SAID...THE SEVERE WEATHER POTENTIAL APPEARS TO BE MARGINAL AT BEST
ACROSS MAINLY THE FAR WESTERN PORTION OF THE UPPER PENINSULA.
THURSDAY NIGHT THROUGH FRIDAY...HAVE KEPT SIMILAR FORECAST TREND
WITH DEVELOPING LAKE EFFECT RAIN SHOWERS ACROSS MAINLY CENTRAL AND
EASTERN PORTIONS OF THE U.P. AS THE UPPER LEVEL 500MB LOW AND
SURFACE LOW BECOME VERTICALLY STACKED NEAR JAMES BAY. THIS WILL
ALLOW AN UPPER LEVEL TROUGH TO EXTEND ACROSS MUCH OF THE GREAT LAKES
REGION KEEPING TEMPERATURES ALOFT COOL ENOUGH...2 TO 4 C AT
H850...TO KEEP THE CHANCE OF RAIN SHOWERS IN THE FORECAST. SURFACE
TEMPERATURES WILL BE AROUND 17C ALLOWING FOR A SURFACE TO H850 DELTA
T OF AROUND 13 TO 15 C. ALONG WITH THE CHANCE OF RAIN
SHOWERS...WINDS MAY ALSO BECOME FAIRLY STRONG ON LAKE SUPERIOR AS
WINDS AROUND H850 ARE EXPECTED TO BE AROUND 25 TO 30 KNOTS. THESE
WINDS SHOULD BE ABLE TO MIX DOWN TO THE LAKE SURFACE WITH UNSTABLE
CONDITIONS SET UP BY THE CAA BEHIND THE LOW.
FRIDAY NIGHT THROUGH TUESDAY...UPPER LEVEL LOW REMAINS FAIRLY
STATIONARY OVER JAMES BAY FRIDAY NIGHT INTO SATURDAY. BY SATURDAY
NIGHT THE GFS AND EC DIFFER ON THE UPPER LEVEL LOW PLACEMENT WITH
THE EC DRIFTING THE LOW NORTHWARD...WHILE THE GFS SINKS THE LOW
SOUTHWARD INTO CENTRAL ONTARIO. CONFIDENCE IS LOW ENOUGH AT THIS
POINT TO STICK WITH A CONSENSUS OF THE MODELS SOLUTIONS. WITH THAT
BEING SAID THE WEATHER PATTERN APPEARS AS THOUGH COOLER WEATHER WILL
LIKELY LINGER INTO AT LEAST THE FIRST PART OF NEXT WEEK WITH
INTERMITTENT CHANCES OF SHOWERS AS MINOR DISTURBANCES ROTATE AROUND
THE LOW. SUNDAY MAY BRING A SLIGHTLY BETTER CHANCE OF SHOWERS AS THE
GFS AND EC SHOW A SHORTWAVE PASSING THROUGH THE AREA...HOWEVER...AS
PREVIOUSLY MENTIONED CONSIDERABLE TIMING DIFFERENCES EXIST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 129 AM EDT WED AUG 15 2012
PATCHY FOG WILL BRING IFR/LIFR CONDITIONS TO KSAW THROUGH MUCH OF
THE NIGHT WITH KCMX AND KIWD REMAINING VFR AS SLIGHTLY DRIER AIR IN
PLACE THERE. THE FOG AT KSAW WILL LIFT BY 12Z WITH VFR CONDITIONS
PREVAILING THROUGH THE REMAINDER OF THE FORECAST. APPROACHING SYSTEM
WILL BRING A SLIGHT CHANCE OF SHOWERS AFTER 19Z OVER THE WEST...AND
A LITTLE LATER AT KSAW. ONCE THE SYSTEM CLOSES IN IN THE LATE
AFTERNOON AND EVENING...SHOWERS AND THUNDERSTORMS BECOME LIKELY
AROUND 0Z AT KIWD AND KCMX AND BY 3Z AT KSAW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 359 PM EDT TUE AUG 14 2012
EXPECT LIGHT WINDS INTO WED MORNING AS AREA OF HI PRES CROSSES THE
UPPER GREAT LAKES. ONCE THE HI CENTER SHIFTS TO THE E AND A COLD
FRONT MOVES IN FROM THE W...WINDS WILL BECOME SSE AND PICK UP AS HI
AS 20 KTS. PLAN ON A SHARP WIND SHIFT TO THE NW LATE ON WED NIGHT/
THU FOLLOWING THIS FRONTAL PASSAGE. THE ARRIVAL OF MUCH COOLER AIR
IN THE WAKE OF THE FRONT OVER THE WARM WATERS OF LAKE SUPERIOR WILL
ALSO RESULT IN ENHANCED MIXING OVER THE LAKE WITH NW WINDS UP TO 30
KTS...STRONGEST ON THU AFTERNOON/EVENING OVER THE E HALF...WHERE
TERRAIN ENHANCES THIS FLOW. EXPECT THE STRONGER NW WINDS TO SLOWLY
SUBSIDE ON FRI THRU THE WEEKEND AS A WEAKER PRES GRADIENT MORE
TYPICAL OF AUG RETURNS TO THE UPPER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KEC
AVIATION...RJT
MARINE...KC
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
315 AM CDT WED AUG 15 2012
.DISCUSSION...
NOT TOO MANY CHGS FOR THIS FORECAST PACKAGE AS THE MAIN SHRTWV
MOVING INTO THE NORTHERN PLAINS WILL BE THE MAIN FOCUS FOR SHORT
TERM CONCERNS.
SCATTERED SHRA/ISOLD TSRA ACROSS S MN HAS BEEN RELATIVELY WEAK
WITH NO ORGANIZATION IN THE PAST FEW HRS. LLJ HAS NOT DEVELOPED IN
SW MN AS THE MODELS EXPECTED WITH SOME INDICATIONS THAT THE SPEED
OF THIS JET HAS LESSENED IN THE PAST COUPLE OF HRS. THIS MAY ONLY
ALLOW FOR ISOLATED CONVECTION ACROSS FAR S MN THIS MORNING...WHICH
WILL TRANSLATE E/NE DURING THE LATE MORNING IN EC MN BEFORE
DECREASING OR DISSIPATING DURING THE AFTN AS CINH DEVELOPS.
CURRENT POPS ARE STILL REASONABLE WITH 30/40S FROM SC TO EC MN
DURING THE MORNING HRS...WITH LESS THAN 20% BY THE AFTN IN EC
MN/WC WI. DEPENDING UPON HOW CONVECTION ACROSS FAR SW MN DEVELOPS
IN THE NEXT TWO HRS WILL DEPEND IF LIKELY POPS ARE NEEDED IN SC
MN.
AS FOR THIS AFTN/EVENING...THE STRONG SHRTWV THAT IS CURRENTLY
MOVING INTO THE NORTHERN PLAINS CONTINUES TO SHOW STRONG LIFT
WITH THE 25H JET STREAK OF 80 KTS ACROSS N MT AS DEPICTED IN THE
LATEST WV IMAGERY. THIS JET AND ASSOCIATED UPPER DYNAMICS WILL
ENHANCE THE OVERALL FORCING ALONG THE COLD FRONT LATER TODAY
ACROSS WESTERN ND/NW MN. PREVIOUS FORECASTS HAD SOME RESERVATIONS
ON THE EXTENT OF THE S/SW TSRA DEVELOPMENT DUE TO THE STRONG
CAPPING. HOWEVER...BASED ON THE CURRENT STRENGTH OF THIS
SYSTEM...AND AMPLE MOISTURE ADVECTING NORTHWARD AHEAD OF THE COLD
FRONT...SHRA/TSRA WILL LIKELY DEVELOP AND SURGE SOUTHEAST ACROSS
MN DURING THE LATE AFTN/EVENING HRS. BEST TIME FRAME OF TSRA
DEVELOPMENT WOULD BE ARND 21Z FROM KFAR TO KINL PER LATEST NMM/ARW
CONVECTIVE SCHEME...WHICH MOVES IT SE TO ARND KFSD TO KMSP TO KDLH
BY 3Z. SVR WX POTENTIAL REMAINS HIGHEST ACROSS THE N/NW FA BEFORE
3Z AS SHEAR VALUES ARE MAXIMIZED ALONG WITH AVAILABLE MLCAPE
VALUES. SEE LATEST SPC DAY1 OUTLOOK FOR MORE INFORMATION.
IN THE WAKE OF THIS POTENT SHRTWV...STRONG SUBSIDENCE WILL LEAD TO
A FAST END TO THE PRECIPITATION OVERNIGHT...WITH ONLY SLIGHT CHC/S
ACROSS THE FAR E FA AFT 12Z.
THE CURRENT COOL DOWN WITH FALL-LIKE TEMPERATURES REMAINS IN CHECK
WITH 92/85H TEMPS STILL RUNNING 1-2 STANDARD DEVIATIONS /SD/ BELOW
NORMAL THRU SUNDAY ACROSS THE FA. OVER THE CENTRAL PLAINS...THESE
NUMBERS ARE NEARLY 3 SD BELOW NORMAL. THE LONG RANGE MODELS STILL
HAVE SOME PROBLEMS PAST THIS WEEKEND IN TERMS OF HOW MUCH
MODIFICATION TO THESE COOL TEMPS IS EXPECTED BY TUE/WED. THE MEAN
UPPER FLOW WILL CHG FROM A STRONG N/NW DIRECTION TO A MORE
WESTERLY DIRECTION BY NEXT WEEK. THE OVERALL MODEL TRENDS HAVE
ALSO BEEN VERY CHAOTIC WITH MORE INFLUENCE OF THE LONG WAVE TROUGH
ACROSS THE EASTERN U.S. VS. THE UPPER RIDGE IN THE SW. WILL
CONTINUE A SLOW MODIFICATION OF TEMPS NEXT WEEK...BUT THESE
READINGS COULD BE LOWER IF THESE TRENDS INDICATE. ..JLT..
&&
.AVIATION.../06Z TAF ISSUANCE/
LLJ WORKING INTO SW MN FINALLY STARTING SPARK OFF A COUPLE OF
SHOWERS...AND HRRR ALONG WITH GEM/NAM/SREF HAVE PICKED UP ON THIS
QUITE WELL...SO ADJUSTED MORNING VCSH MENTION AT RWF/MSP TO
REFLECT SLOWER PRECIP TIMING. BESIDE THESE SHOWERS...LAV CONTINUES
TO PAINT A RATHER PESSIMISTIC PICTURE FOR MVFR CIGS THIS MORNING
WEST OF MSP...BUT WITH NO SUPPORT FOR SAID CIGS FROM THE
RAP/NAM...CONTINUED TO KEEP CONDITIONS VFR THROUGH THE MORNING.
GIVEN STRONG AGREEMENT IN REFLECTIVITY FORECASTS BETWEEN THE
NMM/ARW...CAN NOT ARGUE MUCH WITH GOING TIMING FOR TSRA/FROPA IN
TAFS. AT THIS POINT...ONLY THING I CAN SEE CHANGING WITH THE TSRA
MENTION IS FINE TUNING THE TIMING AND ADDING MORE DETAIL TO
REDUCED FLIGHT CONDITIONS IN TSRA AS WE GET CLOSER TO THEM
OCCURRING. STILL SEEING DEEP MIXING AHEAD OF THE FRONT...WITH NAM
STILL SHOWING GUSTINESS IN SW WINDS THIS AFTERNOON. BEHIND THE
FRONT...OBS IN SRN CANADA THIS EVENING SUPPORT THE IDEA OF SEEING
SOME GUSTY NW WINDS ALONG WITH MVFR/POSSIBLE IFR CIGS IMMEDIATELY
BEHIND THE FRONT IN STRONG COLD AIR ADVECTION.
KMSP...LAST COUPLE HRRR RUNS BRING SHRA ACROSS THE FIELD BETWEEN
12Z AND 15Z THIS MORNING. CERTAINLY CAN NOT RULE THIS OUT...BUT
WITH THIS ACTIVITY STILL IN ITS INFANCY...HARD TO SAY HOW FAR
NORTH IT WILL MAKE...SO STUCK WITH PUSHING THE VCSH MENTION BACK A
FEW HOURS. AFTER THAT...MODELS ALL IN GOOD AGREEMENT ON
TIMING FRONT IN...SO STILL FEEL PRETTY CONFIDENT IN SHRA WINDOW.
CONFIDENCE NOT QUITE SO HIGH IN MVFR CIGS BEHIND THE FRONT...AS
NAM KEEPS BEST 925-850 MB RH BEHIND THE FRONT. WOULD SUSPECT ANY
REDUCED CIGS WOULD LIKELY END BEFORE 12Z...BUT TOO HARD TO PIN
THAT TIMING DOWN AT THIS POINT.
/OUTLOOK FOR MSP/
.THU...VFR WITH POSSIBLE MORNING MVFR CEILINGS. WINDS NW AT
15G20KT.
.FRI...VFR. WINDS NW AT 5 TO 10KTS.
.SAT...VFR. SMALL CHANCE FOR TSRA. WINDS WSW AT 10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JLT/MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1208 AM CDT WED AUG 15 2012
.UPDATE...
06Z AVIATION DISCUSSION ADDED BELOW.
&&
.DISCUSSION...
/ISSUED AT 423 PM CDT TUE AUG 14 2012/
THERE ARE TWO DIFFERENT ROUNDS OF PRECIP IN THE NEAR TERM BEFORE
A DRYING AND COOLING TREND FOR THE WEEKEND. THE THREAT OF SEVERE
WEATHER STILL EXISTS WEDNESDAY EVENING. A COLD FRONT WILL SLIDE
THROUGH WEDNESDAY NIGHT AND FALL-LIKE TEMPERATURES WILL MOVE IN
FOR THE LATTER HALF OF THE WEEK. A COUPLE WEAK DISTURBANCES WILL
MOVE THROUGH AND BRING ADDITIONAL CHANCES FOR RAIN ON SATURDAY AND
TUESDAY...BUT FOR THE MOST PART THE NEXT SEVERAL DAYS WILL BE DRY
AND COOL.
TODAY AND TONIGHT...THE MAIN PCPN CHANCES WILL BE TIED TO SOME
CONTINUED ISENTROPIC LIFT AND MOISTURE ADVECTION ALONG THE LEADING
EDGE OF THE 850MB THETA-E RIDGE/PW PLUME WHICH WILL BE SLIDING EAST
ACROSS THE AREA. THE NAM AND GFS 305K SURFACE DOES A DECENT JOB OF
HIGHLIGHTING WHERE LIFT SHOULD BE MAXIMIZED IN CONCERT WITH
SATURATION... AND SUGGESTS BEST POTENTIAL FOR PCPN WILL BE OVER THE
SOUTHEAST AND EASTERN PORTION OF THE AREA... PARTICULARLY FROM LATE
EVENING INTO THE OVERNIGHT HOURS. THE 850-500MB DIFFERENTIAL THETA-E
FIELDS SHOW A DECENT SLUG OF CONVECTIVE INSTABILITY ACCOMPANYING THE
LOW LEVEL MOISTURE INFLOW AND ISENTROPIC LIFT... SO CERTAINLY NEED
TO KEEP THE MENTION OF THUNDER ALONG WITH SHOWERS. THIS LOOKS TO
FOCUS IN THE SAME AREA... ALTHOUGH THERE IS SOME QUESTION AS TO HOW
MUCH THE LOW LEVEL WINDS WILL INCREASE... AND MOISTURE ADVECTION MAY
NOT PAN OUT TO BE AS STRONG AS THE NEAR-LIKELY POPS SUGGEST. BUT...
THESE SITUATIONS OFTEN WORK OUT TO SUPPORT MORE PCPN THAN THE NWP
MIGHT SUGGEST... SO DECIDED TO BUMP POPS UP SOME FROM WHAT THE WERE
PREVIOUSLY. THIS ELEVATED WARM FRONTAL ASSISTED PCPN SHOULD SHIFT
NORTH/EAST OF MUCH OF THE AREA BY THE END OF TONIGHT. -TRH
WEDNESDAY THROUGH TUESDAY...AN IMPRESSIVE SHORTWAVE APPROACHING THE
IDAHO PANHANDLE WILL DRIVE A COLD FRONT THROUGH THE REGION WEDNESDAY
EVENING WITH SHOWERS AND THUNDERSTORMS DEVELOPING ALONG THIS FRONT.
AN UPSTREAM SPEED MAX WILL ROTATE AROUND THE BASE OF THIS SHORTWAVE
CREATING A FAVORABLE DYNAMIC ENVIRONMENT FOR ORGANIZED CONVECTION.
H500 12HR HEIGHT FALLS OF 60M TOGETHER WITH THE FRONTOGENETIC
FORCING ALONG THE COLD FRONT WILL PROVIDE ADEQUATE LIFT FOR ELEVATED
CONVECTION. THE LIMITING FACTOR WILL BE THERMODYNAMIC IN
NATURE...WITH SURFACE BASED CONVECTION HIGHLY UNLIKELY GIVEN THE
LOW LEVEL COLD AIR ADVECTION. THE SREF REMAINS CONSISTENT WITH
MUCAPES OF 1500 TO 2000J/KG AHEAD OF THE COLD FRONT BY 00Z
THURSDAY. HOWEVER...THE INSTABILITY QUICKLY DIMINISHES OVERNIGHT
WITH LESS THAN 1000J/KG BY 06Z. THEREFORE EXPECTING STORMS TO
DEVELOP BY LATE AFTERNOON NEAR THE SD/ND/MN BORDER SIMILAR TO THE
14.12 WRF NMM SOLUTION. LARGE HAIL AND DAMAGING WIND IS POSSIBLE
SHORTLY AFTER INITIATION WITH A FEW STRONGER CELLS. ANTICIPATING
THAT THE CONVECTION WILL TRY TO GROW UPSCALE ALONG THE FRONT AND
PROGRESS EASTWARD. AS ALLUDED TO EARLIER...DESPITE THE STRONG
FORCING AND DEEP LAYER SHEAR...STORMS MAY HAVE TROUBLE
MAINTAINING THEMSELVES AFTER SUNSET WITH THE FADING MUCAPE.
HOWEVER...THE STRONG SYNOPTIC WINDS WILL STILL HAVE THE POTENTIAL
TO MIX DOWN TO THE SURFACE AND CAUSE ISOLATED DAMAGING WINDS. THUS
SPC CONTINUES TO HIGHLIGHT THIS THREAT WITH A SLIGHT RISK. THE
PRECIP SHOULD BE QUICK TO EXIT THE REGION BY THURSDAY MORNING. THE
MAIN CONCERN WILL THEN BE NORTHWEST WINDS IN THE WAKE OF THE COLD
FRONT. DIFFERENTIAL COLD AIR ADVECTION BETWEEN H925 AND THE
SURFACE WILL DESTABILIZE THE BOUNDARY LAYER AND ALLOW FOR A
BLUSTERY DAY ON THURSDAY. FORECAST SOUNDINGS INDICATE THE
POTENTIAL FOR A THIN AFTERNOON CUMULUS FIELD DEVELOPING SO NOT
ANTICIPATING HIGH TEMPERATURES CLIMBING MUCH PAST THE 70 DEGREE
MARK...IF THAT. LOOKING AHEAD...TWO WAVES MOVE ACROSS THE
REGION...ONE ON SATURDAY...AND THE OTHER TUESDAY. THE ONLY CHANCES
FOR PRECIP WILL HINGE AROUND THESE TWO FEATURES. SOUNDINGS DO SHOW
SOME THIN ELEVATED CAPE...SO HAVE LEFT ISOLATED THUNDER IN THE
GRIDS...BUT THE SEVERE WEATHER THREAT IS NEARLY ZERO. TEMPERATURES
WILL BE NEAR THE SEASONAL AVERAGE. - JRB
&&
.AVIATION.../06Z TAF ISSUANCE/
LLJ WORKING INTO SW MN FINALLY STARTING SPARK OFF A COUPLE OF
SHOWERS...AND HRRR ALONG WITH GEM/NAM/SREF HAVE PICKED UP ON THIS
QUITE WELL...SO ADJUSTED MORNING VCSH MENTION AT RWF/MSP TO
REFLECT SLOWER PRECIP TIMING. BESIDE THESE SHOWERS...LAV CONTINUES
TO PAINT A RATHER PESSIMISTIC PICTURE FOR MVFR CIGS THIS MORNING
WEST OF MSP...BUT WITH NO SUPPORT FOR SAID CIGS FROM THE
RAP/NAM...CONTINUED TO KEEP CONDITIONS VFR THROUGH THE MORNING.
GIVEN STRONG AGREEMENT IN REFLECTIVITY FORECASTS BETWEEN THE
NMM/ARW...CAN NOT ARGUE MUCH WITH GOING TIMING FOR TSRA/FROPA IN
TAFS. AT THIS POINT...ONLY THING I CAN SEE CHANGING WITH THE TSRA
MENTION IS FINE TUNING THE TIMING AND ADDING MORE DETAIL TO
REDUCED FLIGHT CONDITIONS IN TSRA AS WE GET CLOSER TO THEM
OCCURRING. STILL SEEING DEEP MIXING AHEAD OF THE FRONT...WITH NAM
STILL SHOWING GUSTINESS IN SW WINDS THIS AFTERNOON. BEHIND THE
FRONT...OBS IN SRN CANADA THIS EVENING SUPPORT THE IDEA OF SEEING
SOME GUSTY NW WINDS ALONG WITH MVFR/POSSIBLE IFR CIGS IMMEDIATELY
BEHIND THE FRONT IN STRONG COLD AIR ADVECTION.
KMSP...LAST COUPLE HRRR RUNS BRING SHRA ACROSS THE FIELD BETWEEN
12Z AND 15Z THIS MORNING. CERTAINLY CAN NOT RULE THIS OUT...BUT
WITH THIS ACTIVITY STILL IN ITS INFANCY...HARD TO SAY HOW FAR
NORTH IT WILL MAKE...SO STUCK WITH PUSHING THE VCSH MENTION BACK A
FEW HOURS. AFTER THAT...MODELS ALL IN GOOD AGREEMENT ON
TIMING FRONT IN...SO STILL FEEL PRETTY CONFIDENT IN SHRA WINDOW.
CONFIDENCE NOT QUITE SO HIGH IN MVFR CIGS BEHIND THE FRONT...AS
NAM KEEPS BEST 925-850 MB RH BEHIND THE FRONT. WOULD SUSPECT ANY
REDUCED CIGS WOULD LIKELY END BEFORE 12Z...BUT TOO HARD TO PIN
THAT TIMING DOWN AT THIS POINT.
/OUTLOOK/
.THU...VFR WITH POSSIBLE MORNING MVFR CEILINGS. WINDS NW AT
15G20KT.
.FRI...VFR. WINDS NW AT 5 TO 10KTS.
.SAT...VFR. SMALL CHANCE FOR TSRA. WINDS WSW AT 10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
TRH/JRB/MPG
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1146 PM CDT TUE AUG 14 2012
.AVIATION...
06Z TAFS FOR KOMA...KLNK...AND KOFK.
VFR CONDITIONS FOR MUCH OF THE PERIOD WITH CHANCE OF
STORMS AFTER 00Z. SOUTH WINDS INCREASING AFTER 14Z THEN
SHIFTING TO NORTHWEST BEHIND THE FRONT 00Z-06Z.
&&
.PREV DISCUSSION... /ISSUED 237 PM CDT TUE AUG 14 2012/
DISCUSSION...
88D MOSAIC LOOP THIS AFTERNOON SHOWING SMALL AREA OF ELEVATED
CONVECTION SLOWLY MOVING ACROSS THE NRN CWA. A FEW STATIONS HAVE
HAD HOURLY PCPN AROUND A TENTH OR SO. EXPECT THOUGH ACTIVITY WILL
WEAKEN AS IT PROGRESSES EASTWARD INTO AREA OF HIGHER CINH.
FOR TONIGHT...NAM/GFS/ECM ALL PLACING SMALL AREA OF QPF IN THE
VICINITY OF THE NRN CWA ASSOCIATED WITH WAA FORCING LIFTING NORTH
INTO THE DAKOTAS/UPPER MIDWEST. HOWEVER...12Z RUN OF 4KM WRF IS DRY
AS WELL AS RAP GUIDANCE.
OTHERWISE...LARGE SCALE FLOW CONSISTING OF A DEEP BROAD TROF
ESTABLISHED OVER THE EASTERN CONUS WITH UPSTREAM NORTHWEST FLOW
EXTENDING ALL THE WAY TO THE BRITISH COLUMBIA COASTLINE. PATTERN
THOUGH WILL GRADUALLY ALTER LATER THIS WEEK WHEN DEEP LOW PRESSURE
OVER THE ALASKAN GULF SHIFT EAST AND PUSHES AN AMPLIFYING RIDGE
TOWARD THE ROCKIES.
IN THE MEANTIME...SHORT TERM FEATURE OF INTEREST CONTINUES TO BE
ANTICIPATED COLD FRONT PUSHING DEEP INTO PLAINS ON WEDNESDAY. LEADING
EDGE OF COLD FRONT SHOULD BE PUSHING INTO THE NRN CWA BY AFTERNOON
AND QUICKLY SLIDE SEWD THROUGH THURSDAY MORNING. SVR STORM THREAT AS
THE BNDRY PUSHES THRU QUITE POSSIBLE IF NOT LIKELY WHEN CAP WEAKENS
BY LATE AFTN. INSTABILITY AND SHEAR WILL BE ABUNDANT...MUCAPE 3500
J/KG...LI -7...EFFECTIVE SHEAR 30-40KT...TO PRODUCE STORMS
CONTAINING LARGE HAIL AND DAMAGING WINDS. EXPECT LINGERING PCPN
ACTIVITY THURSDAY MORNING...FOR THE MOST PART SOUTH OF I-80...SHOULD
COME TO A CLOSE BEFORE AFTN. THIS FRONT WILL BRING A NOTICEABLE
CHANCE IN TEMPS...COMPARED TO AS OF LATE...WITH HIGHS THURSDAY THRU
SUNDAY IN THE MID/UPPER 70S.
FOR MONDAY AND TUESDAY...EXPECT A SLIGHT WARMING TREND OVER THE
CNTRL PLAINS AS AFOREMENTIONED UPPER RIDGE SLIDES CLOSER TO THE
REGION. SHOULD BE ABLE TO REACH LOW/MID 80S FOR AFTN HIGHS.
DEE
AVIATION...
18Z TAFS FOR KOMA...KLNK...AND KOFK.
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ASSOCIATED WITH A
WEAK UPPER LEVEL IMPULSE...ALONG AND AND NORTH A WEAK MID LEVEL
FRONTAL BOUNDARY WILL CONTINUE TO MOVE THROUGH NORTHEAST
NEBRASKA...AFFECTING THE KOFK TAF SITE THROUGH ABOUT 20Z.
OTHERWISE...VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD WITH
SOUTH SOUTHWESTERLY WINDS AROUND 12 KNOTS. COULD BE SOME SPORADIC
GUSTS UP TO ABOUT 18 KNOTS. GUSTS COULD REDEVELOP BY 15/15Z
TOMORROW AS WELL AHEAD OF THE NEXT COLD FRONT.
DEWALD
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
FOBERT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
238 AM EDT WED AUG 15 2012
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL APPROACH THE MOUNTAINS FROM THE WEST
THIS MORNING...THEN MOVE EASTWARD ACROSS THE CAROLINAS THIS
AFTERNOON AND EVENING. WEAK HIGH PRESSURE WILL BUILD INTO THE AREA
FROM THE WEST TONIGHT AND THURSDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY NIGHT/...
AS OF 900 PM TUESDAY...
THROUGH TONIGHT: THE RISK FOR WIDELY SCATTERED STORMS WILL PERSIST
FOR AT LEAST A FEW MORE HOURS. WATER VAPOR IMAGERY REVEALS AN
ELONGATED SHORTWAVE TROUGH OVER ERN NC... ACCOMPANYING A POCKET OF
WEAK UPPER DIVERGENCE. A SECOND WEAKER MID LEVEL WAVE OVER THE NC
FOOTHILLS HAS HELPED FUEL ISOLATED STRONG TO SEVERE STORMS IN THE
HIGHER TERRAIN... AND FOLLOWING THE MEAN CLOUD LAYER FLOW THESE
SHOULD MOVE TO THE NE AND ENE INTO CENTRAL NC. THE STEADY LOW LEVEL
FLOW FROM THE SW AHEAD OF THE INCOMING COLD FRONT HAS HELPED KEEP
DEW POINTS IN THE UPPER 60S TO AROUND 70... YIELDING MODERATELY
UNSTABLE MLCAPE VALUES OF 1500-2500 J/KG... WHILE LOW LEVEL LAPSE
RATES REMAIN STEEP AT 6.5-7.0 C/KM WITH A FAVORABLE EFFECTIVE SHEAR
NEAR 25 KTS. BUT THE GRADUAL LOSS OF HEATING... AS WELL AS THE
EVENTUAL DEPARTURE OF THE WEAK WRN-NC WAVE UP INTO VA AND DAMPENING
IN FAVOR OF THE STRONGER MID MISS VALLEY TROUGH MOVING THROUGH KY
TONIGHT... SHOULD ALLOW FOR A SLOW REDUCTION OF (ALREADY-SMALL)
STORM COVERAGE AND STRENGTH AS WE HEAD THROUGH THE REST OF THE
EVENING AND INTO THE OVERNIGHT HOURS. THIS IS SUPPORTED BY A NUMBER
OF CONVECTION-ALLOWING MODELS INCLUDING THE HRRR AND LOCAL WRF-ARW.
WILL DEPICT SCATTERED STORMS FOR A FEW MORE HOURS FOLLOWED BY A
TREND TOWARD NO POPS SHORTLY AFTER MIDNIGHT. GIVEN THE INSTABILITY
AND SHEAR... ANY STORMS FOR THE NEXT FEW HOURS COULD STILL BE
STRONG. EXPECT PRIMARILY PARTLY CLOUDY SKIES TONIGHT WITH A
COMBINATION OF CONVECTIVE DEBRIS CLOUDS AND CIRRUS OUT AHEAD OF THE
MID MISS VALLEY WAVE. LOWS OF 67-72 STILL APPEAR REASONABLE AND ARE
IN LINE WITH THE PACE OF THE CURRENT TEMPERATURE FALLS. -GIH
WEDNESDAY AND WEDNESDAY NIGHT:
WEAK COLD FRONT IS EXPECTED TO CROSS THE MOUNTAINS WEDNESDAY MORNING
AND EVENTUALLY WORK ITS WAY EASTWARD ACROSS THE AREA THROUGH
DAYLIGHT HOURS. WHILE HEIGHT FALLS ALOFT ARE EXPECTED TO BE RATHER
WEAK(20 METERS)...AMPLIFYING SHORTWAVE ENERGY CURRENTLY OVER THE
CENTRAL PLAINS/MID WILL ROTATE EASTWARD THROUGH THE AREA BETWEEN 12Z
WED TO 00Z THU...LIKELY AUGMENTING VERTICAL ACCELERATIONS
WITHIN THE JET DIVERGENCE REGION OF A 45KT AND 65KT MID AND UPPER
LEVEL JET STREAK TRAVERSING THE AREA. UNLIKE THE PAST FEW
DAYS...CAPE WILL BE AT PREMIUM...AIDED BY THE PRESENCE OF STEEPER
LAPSE RATES ALOFT OF 7.0-7.5 C/KM PER LATEST GFS...WITH MODELS
DEPICTING MODERATE TO STRONG DESTABILIZATION(2000 TO 3000 J/KG OF
MLCAPE) FROM US 1 EAST. DRIER AIR ALOFT ADVECTING WEST TO EAST
THROUGH THE CAROLINAS COULD LIMIT AREAL CONVECTIVE
COVERAGE...ESPECIALLY IN THE WEST...BUT EXPECT STRONG INSTABILITY IN
THE EAST TO HELP OVERCOME DRYING ALOFT TO SUPPORT AT LEAST CHANCE
POPS. THIS MID LEVEL DRY AIR COULD ALSO HOWEVER RESULT IN A GREATER
RISK DAMAGING THUNDERSTORM WIND GUSTS WITH ANY STRONG CELL THAT DOES
DEVELOP. AS SUCH...SPC HAS AREAS FROM US 1 EAST IN THE DAY 2 SLIGHT
RISK.
THE SHORTWAVE VORT MAX IS FORECAST TO CLEAR BY 00Z...WITH TRAILING
SFC FRONT SOON AFTERWARD. THUS EXPECT STORMS TO QUICKLY SHIFT EAST
OF THE AREA SHORTLY AFTER 00Z THU WITH SKIES BECOMING CLEAR AS DRY
SURFACE HIGH PRESSURE BUILDS INTO THE AREA OVERNIGHT.
HIGHS WEDNESDAY MUCH LIKE TODAY...RANGING FROM MID 80S WEST TO UPPER
80S TO AROUND 90 PRETTY MUCH EVERYWHERE ELSE. SLIGHTLY COOLER WITH
DRIER AIR BUILDING IN AND DECENT RADIATIONAL COOLING. MINS IN THE
LOWER TO MID 60S NORTH AND WEST TO UPPER 60S SOUTHEAST. -CBL
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
AS OF 200 AM WEDNESDAY...
WEAK HIGH PRESSURE WILL BUILD IN FROM THE NORTH DURING THURSDAY. THE
DEW POINTS ARE FORECAST TO FALL OFF INTO THE MID TO UPPER 50S ACROSS
THE NORTHWEST PIEDMONT AND 60-65 ELSEWHERE. SUNNY SKIES AND LIGHT
WIND ARE FORECAST WITH HIGHS IN THE 87-92 RANGE. FAIR SKIES ARE
FORECAST THURSDAY NIGHT AS THE WEAK HIGH PRESSURE MOVES OVERHEAD.
LOWS WILL BE MOSTLY IN THE MID TO UPPER 60S.
THE HIGH WILL SHIFT OFFSHORE FRIDAY. THIS WILL BE IN RESPONSE TO THE
NEXT UNSEASONABLY STRONG MID-UPPER TROUGH THAT WILL BE APPROACHING
FROM THE NORTHWEST. THE RETURN SW FLOW WILL INCREASE TO 10-15 MPH
AIDING IN INCREASING LOW LEVEL MOISTURE AS DEW POINTS SHOULD RECOVER
INTO THE MID TO UPPER 60S. HIGHS WILL RETURN TO THE LOWER TO MID 90S
EXCEPT UPPER 80S IN THE NW PIEDMONT. SCATTERED THUNDERSTORMS ARE
EXPECTED BY LATE AFTERNOON ACROSS THE NW PIEDMONT IN ASSOCIATION
WITH THE COMBINATION OF THE APPROACHING UPPER HEIGHT FALLS... ALONG
WITH A PRE-FRONTAL TROUGH AND POSSIBLY CONVECTIVE OUTFLOWS FROM
UPSTREAM. WE WILL GO ABOVE GUIDANCE AND FORECAST 40-50 POP FOR LATE
DAY IN THE NW... AND CARRY SLIGHT CHANCES ELSEWHERE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 215 AM WEDNESDAY...
MODELS HAVE GENERALLY BEEN TRENDING TOWARD A LESS PROGRESSIVE
MID-UPPER TROUGH TO AFFECT THE REGION THIS WEEKEND. THE LATEST GFS
INDICATES A MUCH WETTER SCENARIO OVER NC WITH A COUPLE OF WAVES
DEVELOPING ALONG A STALLED LOW LEVEL BOUNDARY ACROSS SOUTHERN AND
EASTERN NORTH CAROLINA SATURDAY THROUGH MONDAY. WE WILL TREND TOWARD
A CLOUDIER AND WETTER SCENARIO WITH HIGHER POPS EXCEPT DRIER NW
SATURDAY... THEN HIGHER POPS ALL ZONES BY SUNDAY AND MONDAY...
LINGERING INTO POSSIBLY MID-WEEK.
HIGHS WILL BE TEMPERED QUITE A BIT BY NOT ONLY A LOW LEVEL EASTERLY
FLOW BUT FREQUENT SHOWERS. SOME NORTHERN PIEDMONT ZONES MAY HOLD
BELOW 80 A FEW DAYS.
&&
.AVIATION /06Z WEDNESDAY THROUGH MONDAY/...
AS OF 230 AM WEDNESDAY...
24-HR TAF PERIOD:
ASIDE FROM ISOLATED SHOWERS (PRIMARILY AT THE FAY TERMINAL) THIS
MORNING...VFR CONDITIONS ARE GENERALLY EXPECTED TO PREVAIL THROUGH
15-18Z. SCATTERED SHOWERS AND STORMS ARE EXPECTED TO DEVELOP THIS
AFTERNOON AHEAD OF AN UPPER LEVEL DISTURBANCE APPROACHING FROM THE
WEST...POTENTIALLY AFFECTING ALL TAF SITES...THOUGH THE HIGHEST
PROBABILITY WILL BE AT THE RDU/FAY/RWI TERMINALS. THE RELATIVE BEST
CHANCE WILL BE BETWEEN 19Z THIS AFTERNOON AND 02Z THIS EVENING. AN
ISOLD SEVERE STORM WITH SURFACE WIND GUSTS AOA 50 KT WILL ALSO BE
POSSIBLE. OTHERWISE...VFR CONDITIONS ARE EXPECTED TO PREDOMINATE...
WITH A SMALL CHANCE FOR MVFR FOG AT THE RDU/FAY/RWI TERMINALS
BETWEEN 06-12Z THURSDAY MORNING.
LOOKING AHEAD:
VFR CONDITIONS ARE EXPECTED TO PREVAIL THU/THU NIGHT AS WEAK HIGH
PRESSURE BUILDS OVER THE CAROLINAS FROM THE WEST. SCATTERED SHOWERS
AND STORMS ARE EXPECTED FRIDAY AFTERNOON THROUGH THE WEEKEND AS AN
UPPER LEVEL TROUGH SLOWLY APPROACHES FROM THE WEST. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...HARTFIELD/CBL
SHORT TERM...BADGETT
LONG TERM...BADGETT
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
215 AM EDT WED AUG 15 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTHEAST THROUGH THE AREA THIS AFTERNOON AND
EVENING. WEAK HIGH PRESSURE WILL BUILD IN FROM THE NORTH TONIGHT AND
THURSDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY NIGHT/...
AS OF 900 PM TUESDAY...
THROUGH TONIGHT: THE RISK FOR WIDELY SCATTERED STORMS WILL PERSIST
FOR AT LEAST A FEW MORE HOURS. WATER VAPOR IMAGERY REVEALS AN
ELONGATED SHORTWAVE TROUGH OVER ERN NC... ACCOMPANYING A POCKET OF
WEAK UPPER DIVERGENCE. A SECOND WEAKER MID LEVEL WAVE OVER THE NC
FOOTHILLS HAS HELPED FUEL ISOLATED STRONG TO SEVERE STORMS IN THE
HIGHER TERRAIN... AND FOLLOWING THE MEAN CLOUD LAYER FLOW THESE
SHOULD MOVE TO THE NE AND ENE INTO CENTRAL NC. THE STEADY LOW LEVEL
FLOW FROM THE SW AHEAD OF THE INCOMING COLD FRONT HAS HELPED KEEP
DEW POINTS IN THE UPPER 60S TO AROUND 70... YIELDING MODERATELY
UNSTABLE MLCAPE VALUES OF 1500-2500 J/KG... WHILE LOW LEVEL LAPSE
RATES REMAIN STEEP AT 6.5-7.0 C/KM WITH A FAVORABLE EFFECTIVE SHEAR
NEAR 25 KTS. BUT THE GRADUAL LOSS OF HEATING... AS WELL AS THE
EVENTUAL DEPARTURE OF THE WEAK WRN-NC WAVE UP INTO VA AND DAMPENING
IN FAVOR OF THE STRONGER MID MISS VALLEY TROUGH MOVING THROUGH KY
TONIGHT... SHOULD ALLOW FOR A SLOW REDUCTION OF (ALREADY-SMALL)
STORM COVERAGE AND STRENGTH AS WE HEAD THROUGH THE REST OF THE
EVENING AND INTO THE OVERNIGHT HOURS. THIS IS SUPPORTED BY A NUMBER
OF CONVECTION-ALLOWING MODELS INCLUDING THE HRRR AND LOCAL WRF-ARW.
WILL DEPICT SCATTERED STORMS FOR A FEW MORE HOURS FOLLOWED BY A
TREND TOWARD NO POPS SHORTLY AFTER MIDNIGHT. GIVEN THE INSTABILITY
AND SHEAR... ANY STORMS FOR THE NEXT FEW HOURS COULD STILL BE
STRONG. EXPECT PRIMARILY PARTLY CLOUDY SKIES TONIGHT WITH A
COMBINATION OF CONVECTIVE DEBRIS CLOUDS AND CIRRUS OUT AHEAD OF THE
MID MISS VALLEY WAVE. LOWS OF 67-72 STILL APPEAR REASONABLE AND ARE
IN LINE WITH THE PACE OF THE CURRENT TEMPERATURE FALLS. -GIH
WEDNESDAY AND WEDNESDAY NIGHT:
WEAK COLD FRONT IS EXPECTED TO CROSS THE MOUNTAINS WEDNESDAY MORNING
AND EVENTUALLY WORK ITS WAY EASTWARD ACROSS THE AREA THROUGH
DAYLIGHT HOURS. WHILE HEIGHT FALLS ALOFT ARE EXPECTED TO BE RATHER
WEAK(20 METERS)...AMPLIFYING SHORTWAVE ENERGY CURRENTLY OVER THE
CENTRAL PLAINS/MID WILL ROTATE EASTWARD THROUGH THE AREA BETWEEN 12Z
WED TO 00Z THU...LIKELY AUGMENTING VERTICAL ACCELERATIONS
WITHIN THE JET DIVERGENCE REGION OF A 45KT AND 65KT MID AND UPPER
LEVEL JET STREAK TRAVERSING THE AREA. UNLIKE THE PAST FEW
DAYS...CAPE WILL BE AT PREMIUM...AIDED BY THE PRESENCE OF STEEPER
LAPSE RATES ALOFT OF 7.0-7.5 C/KM PER LATEST GFS...WITH MODELS
DEPICTING MODERATE TO STRONG DESTABILIZATION(2000 TO 3000 J/KG OF
MLCAPE) FROM US 1 EAST. DRIER AIR ALOFT ADVECTING WEST TO EAST
THROUGH THE CAROLINAS COULD LIMIT AREAL CONVECTIVE
COVERAGE...ESPECIALLY IN THE WEST...BUT EXPECT STRONG INSTABILITY IN
THE EAST TO HELP OVERCOME DRYING ALOFT TO SUPPORT AT LEAST CHANCE
POPS. THIS MID LEVEL DRY AIR COULD ALSO HOWEVER RESULT IN A GREATER
RISK DAMAGING THUNDERSTORM WIND GUSTS WITH ANY STRONG CELL THAT DOES
DEVELOP. AS SUCH...SPC HAS AREAS FROM US 1 EAST IN THE DAY 2 SLIGHT
RISK.
THE SHORTWAVE VORT MAX IS FORECAST TO CLEAR BY 00Z...WITH TRAILING
SFC FRONT SOON AFTERWARD. THUS EXPECT STORMS TO QUICKLY SHIFT EAST
OF THE AREA SHORTLY AFTER 00Z THU WITH SKIES BECOMING CLEAR AS DRY
SURFACE HIGH PRESSURE BUILDS INTO THE AREA OVERNIGHT.
HIGHS WEDNESDAY MUCH LIKE TODAY...RANGING FROM MID 80S WEST TO UPPER
80S TO AROUND 90 PRETTY MUCH EVERYWHERE ELSE. SLIGHTLY COOLER WITH
DRIER AIR BUILDING IN AND DECENT RADIATIONAL COOLING. MINS IN THE
LOWER TO MID 60S NORTH AND WEST TO UPPER 60S SOUTHEAST. -CBL
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
AS OF 200 AM WEDNESDAY...
WEAK HIGH PRESSURE WILL BUILD IN FROM THE NORTH DURING THURSDAY. THE
DEW POINTS ARE FORECAST TO FALL OFF INTO THE MID TO UPPER 50S ACROSS
THE NORTHWEST PIEDMONT AND 60-65 ELSEWHERE. SUNNY SKIES AND LIGHT
WIND ARE FORECAST WITH HIGHS IN THE 87-92 RANGE. FAIR SKIES ARE
FORECAST THURSDAY NIGHT AS THE WEAK HIGH PRESSURE MOVES OVERHEAD.
LOWS WILL BE MOSTLY IN THE MID TO UPPER 60S.
THE HIGH WILL SHIFT OFFSHORE FRIDAY. THIS WILL BE IN RESPONSE TO THE
NEXT UNSEASONABLY STRONG MID-UPPER TROUGH THAT WILL BE APPROACHING
FROM THE NORTHWEST. THE RETURN SW FLOW WILL INCREASE TO 10-15 MPH
AIDING IN INCREASING LOW LEVEL MOISTURE AS DEW POINTS SHOULD RECOVER
INTO THE MID TO UPPER 60S. HIGHS WILL RETURN TO THE LOWER TO MID 90S
EXCEPT UPPER 80S IN THE NW PIEDMONT. SCATTERED THUNDERSTORMS ARE
EXPECTED BY LATE AFTERNOON ACROSS THE NW PIEDMONT IN ASSOCIATION
WITH THE COMBINATION OF THE APPROACHING UPPER HEIGHT FALLS... ALONG
WITH A PRE-FRONTAL TROUGH AND POSSIBLY CONVECTIVE OUTFLOWS FROM
UPSTREAM. WE WILL GO ABOVE GUIDANCE AND FORECAST 40-50 POP FOR LATE
DAY IN THE NW... AND CARRY SLIGHT CHANCES ELSEWHERE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 215 AM WEDNESDAY...
MODELS HAVE GENERALLY BEEN TRENDING TOWARD A LESS PROGRESSIVE
MID-UPPER TROUGH TO AFFECT THE REGION THIS WEEKEND. THE LATEST GFS
INDICATES A MUCH WETTER SCENARIO OVER NC WITH A COUPLE OF WAVES
DEVELOPING ALONG A STALLED LOW LEVEL BOUNDARY ACROSS SOUTHERN AND
EASTERN NORTH CAROLINA SATURDAY THROUGH MONDAY. WE WILL TREND TOWARD
A CLOUDIER AND WETTER SCENARIO WITH HIGHER POPS EXCEPT DRIER NW
SATURDAY... THEN HIGHER POPS ALL ZONES BY SUNDAY AND MONDAY...
LINGERING INTO POSSIBLY MID-WEEK.
HIGHS WILL BE TEMPERED QUITE A BIT BY NOT ONLY A LOW LEVEL EASTERLY
FLOW BUT FREQUENT SHOWERS. SOME NORTHERN PIEDMONT ZONES MAY HOLD
BELOW 80 A FEW DAYS.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
AS OF 745 PM TUESDAY...
24-HR TAF PERIOD...
SCATTERED SHOWERS AND STORMS AROUND THE REGION HAVE REMAINED OUTSIDE
OF CENTRAL NC THUS FAR THIS EVENING. RADAR TRENDS SUGGEST A SMALL
CLUSTER OF STORMS NEAR KHKY MAY IMPACT KINT AND/OR KGSO BY
01-02Z...WITH MVFR OR IFR CEILINGS/VSBYS AND WIND GUSTS OF 30-40MPH
POSSIBLE. SHOWERS AND STORMS MAY CONTINUE TO DEVELOP THIS EVENING
AS AN UPPER LEVEL DISTURBANCE SWINGS ACROSS THE AREA FROM THE
WEST...BUT DWINDLING INSTABILITY SHOULD LIMIT THE COVERAGE AND
INTENSITY. OTHERWISE...MVFR PRE-DAWN MVFR VSBYS ARE MOSTLY LIKELY
AT KRWI AND KFAY.
FOR WEDNESDAY...A WEAK COLD FRONT WILL MOVE INTO THE AREA DURING THE
DAY...AND SHOULD BE THE FOCUS FOR STORMS ACROSS MAINLY EASTERN NC
WEDNESDAY AFTERNOON. HAVE KEPT THE MENTION OF VCSH FROM THE
PREVIOUS TAF...AND SUBSEQUENT ISSUANCES MAY HAVE BETTER CONFIDENCE
IN THE POTENTIAL TIMING OF STORMS AT KFAY AND KRWI.
OUTLOOK...
DRY/VFR CONDITIONS THU AND THU NIGHT AS WEAK HIGH PRESSURE BUILDS
INTO THE AREA FROM THE WEST. A PROLONGED PERIOD OF ADVERSE AVIATION
CONDITIONS ARE POSSIBLE BY LATE FRIDAY AND THROUGH THE WEEKEND
AS UNSEASONABLY STRONG UPPER LEVEL TROUGH SETTLES OVER THE EASTERN
US...RESULTING IN WIDESPREAD SHOWERS AND STORMS.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BADGETT
NEAR TERM...HARTFIELD/CBL
SHORT TERM...BADGETT
LONG TERM...BADGETT
AVIATION...CBL/SMITH
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1253 AM EDT WED AUG 15 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL BRING A CHANCE FOR THUNDERSTORMS THROUGH
WEDNESDAY. THE FRONT IS EXPECTED TO DISSIPATE ON THURSDAY. A
STRONGER COLD FRONT WILL APPROACH FOR THE WEEKEND...BRINGING
INCREASING CHANCES FOR THUNDERSTORMS. MUCH COOLER AIR IS POSSIBLE
FOR MONDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 1245 AM WEDNESDAY...A SUBTLE UPPER DISTURBANCE IS IGNITING A
NEW ROUND OF CONVECTION IN THE SC PEE DEE REGION JUST SOUTH OF
FLORENCE CURRENTLY. THE PAST FEW HRRR RUNS HAVE BEEN VERY BULLISH
WITH THIS CLUSTER OF STORMS EXPANDING IN AREA AS IT MOVES ENE TOWARD
THE CAPE FEAR/MYRTLE BEACH REGION OVER THE NEXT 2-3 HOURS. WE`VE
EXPANDED A SWATH OF 30-60 POPS OUT AHEAD OF THE PREDICTED PATH OF
THIS DISTURBANCE THROUGH 08Z/4 AM EDT. WITH A SLIGHTLY STRONGER THAN
EXPECTED SW LOW LEVEL JET TEMPERATURES ARE RUNNING ABOVE
PREDICTIONS...SO WE`VE BUMPED LOW TEMPERATURES UP A DEGREE OR TWO
ESPECIALLY NEAR THE COAST. NO OTHER SIGNIFICANT CHANGES. PREVIOUS
DISCUSSION FROM 10 PM TUESDAY FOLLOWS...
CONVECTION PEAKED ACROSS THE FORECAST AREA BETWEEN 630 AND 830 PM.
ONE CELL IN EASTERN BLADEN COUNTY DID SPIKE TO NEAR SEVERE LEVELS
AROUND 8 PM. SINCE 8 PM...SHOWERS HAVE DIMINISHED ACROSS THE AREA.
UPSTREAM CONVECTION AHEAD OF WEAK MID-LEVEL SHORTWAVE HAS ALSO
WEAKENED SIGNIFICANTLY.
FIRST MID-LEVEL SHORTWAVE SLIPPED OFF THE COAST EARLIER THIS EVE.
ANOTHER...WEAK SHORTWAVE EMBEDDED IN WSW FLOW WILL WEAKEN FURTHER AS
IT MOVES ACROSS THE EASTERN CAROLINAS OVERNIGHT. WILL CARRY SLIGHT
CHANCE/LOW CHANCE OF A SHOWER OR THUNDERSTORM OVERNIGHT...HIGHEST
ACROSS SOUTHWEST AND WESTERN ZONES. OVERALL...EXPECT THE RISK FOR
SHOWERS AND THUNDERSTORMS TO TRANSITION OFFSHORE DURING THE LATE
NIGHT HOURS AS BOUNDARY LAYER COOLING MAXIMIZES...TYPICAL FOR THIS
TIME OF YEAR.
SOME STRATUS AND FOG ARE EXPECTED TO DEVELOP LATE TONIGHT. MODELS DO
DEVELOP A PRONOUNCED INVERSION...BUT ARE NOT INDICATING SURFACE
BASED SATURATION. WINDS ABOVE THE BOUNDARY LAYER ARE FORECAST TO
REMAIN IN THE 10 TO 15 KT RANGE. AT THIS TIME...WILL INCLUDE PATCHY
LATE NIGHT FOG...PRIMARILY ACROSS INLAND AREAS...WHERE CONVECTIVE
CLOUDS DEBRIS WILL CLEAR EARLIEST.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
AS OF 3 PM TUESDAY...A PASSING SHORTWAVE TROUGH ALOFT AND THE
ATTENDANT COLD FRONT WILL AFFECT THE AREA WEDNESDAY INTO WEDNESDAY
NIGHT...PRODUCING SCATTERED SHOWERS AND THUNDERSTORMS. THE TROUGH
WILL MOVE OFF TO THE EAST WEDNESDAY NIGHT AS THE FRONT
DISSIPATES...LEAVING THE AREA UNDER HIGH PRESSURE FOR THE REMAINDER
OF THE PERIOD...RESULTING IN FAIR WEATHER. MAX TEMPERATURES EACH
DAY WILL BE IN THE UPPER 80S TO LOWER 90S WITH MINS IN THE UPPER 60S
TO LOWER 70S.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 3 PM TUESDAY...DOWNSLOPING ZONAL FLOW ON FRIDAY WILL TEND TO
KEEP THE AREA DRY FOR THE MOST PART. A SHORTWAVE CUTTING ACRS
SOUTHERN ZONES MAY INTERACT WITH PIEDMONT TROUGH AND SEA BREEZE TO
TOUCH OF AN ISO THUNDERSTORM OR TWO. TEMPS NEAR OR A FEW DEG ABV
CLIMO. MEANWHILE A BROAD TROUGH FROM HUDSON BAY INTO GREAT LAKES
WILL BE AMPLIFYING. BACKING BOUNDARY LAYER WINDS ACRS THE SOUTHEAST
WILL IMPORT MOISTURE FRIDAY NIGHT INTO SATURDAY BRINGING AN INCREASE
IN RAIN CHANCES ESP WITH MID LVL CYCLONIC CURVATURE ON THE RISE
LOCALLY. OVER THE WEEKEND THE MAIN SOUTHWARD PUSH OF THE MID LEVEL
WAVE WILL REMAIN WELL WEST OF HERE WHICH MAY PRECLUDE A CLEAN FROPA.
RATHER THE FRONT WILL LAZILY AMBLE THROUGH THE COASTAL CAROLINAS
DURING THE SUNDAY THROUGH MONDAY TIMEFRAME. THIS WILL KEEP THE
WEATHER UNSETTLED BUT ALSO PREVENT PINPOINTING A DAY WHERE RAINFALL
CHANCES AND QPF PROSPECTS ARE MAXIMIZED. DAYTIME TEMPS WILL TAKE A
HIT FROM CLOUD COVER RATHER THAN ADVECTION. NIGHTTIME LOWS WILL
REMAIN AT OR ABOVE CLIMO AGAIN DUE TO CLOUDS.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 06Z...VFR EXPECTED THROUGH PERIOD...WITH EXCEPTION OF EARLY
MORNING THUNDERSTORMS...POTENTIAL MVFR DUE TO FOG/STRATUS BEFORE
DAYBREAK...AND AFTERNOON T-STORMS.
OVERNIGHT...CONVECTION JUST SE OF KFLO IS SHOWN ON THE LATEST HRRR
MODEL RUNS TO EXPAND AS IT APPROACHES KCRE/KILM OVER THE NEXT 2-3
HOURS. POTENTIAL IFR BEFORE DAYBREAK AT THE INLAND TERMINALS DUE TO
LOW STRATUS AND/OR BR IF SFC WINDS DIMINISH.
AFTER DAYBREAK...ANY LINGERING FOG WILL QUICKLY DISSIPATE ALLOWING
FOR VFR TO PREVAIL THROUGHOUT MUCH OF THE DAY. SCATTERED TSRA
SCENARIO POSSIBLE IN THE AFTERNOON HOURS AS AN UPPER LEVEL
DISTURBANCE MOVES EAST. FOR THE EVENING HOURS...LINGERING TSRA
SHOULD END NEAR THE COAST...WITH DEBRIS CLOUDINESS REMAINING
OVERNIGHT.
EXTENDED OUTLOOK...MORNING FOG AND SCATTERED CONVECTION IS POSSIBLE
THROUGH SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1245 AM WEDNESDAY...BUMPED UP WIND SPEEDS A BIT BASED ON
CURRENT OBSERVATIONS. THE REASON IS PROBABLY A SLIGHTLY STRONGER
THAN EXPECTED SW LOW LEVEL JET AS A SUBTLE UPPER DISTURBANCE MOVES
INTO EASTERN SOUTH CAROLINA. THIS DISTURBANCE IS ALSO ACCOMPANIED BY
CONVECTION IN THE FLORENCE VICINITY. WE`LL WATCH THIS CLOSELY TO SEE
IF IT POSES A THREAT FOR THE CAROLINA COASTAL WATERS OVER THE NEXT
2-4 HOURS. PREVIOUS DISCUSSION FROM 10 PM TUESDAY FOLLOWS...
BERMUDA HIGH PRESSURE WILL ALLOW SW WINDS TO PERSIST ACROSS THE
WATERS. NOCTURNAL JETTING LOOKS MEAGER AND SO WIND SPEEDS ARE NOT
EXPECTED TO BE ANY HIGHER THAN 10 TO 15 KT THROUGH THE NIGHT.
ACCORDINGLY...SEAS WILL HOLD IN THE 2 TO 3 FT RANGE. A WEAK 8 TO 9
SECOND SE SWELL WILL PERSIST.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM TUESDAY...EXPECT LIGHT WINDS OF 10 TO 15 KT FROM THE
SOUTHWEST QUADRANT THROUGH THE PERIOD WITH SEAS GENERALLY 2 TO 3
FT.
LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 3 PM TUESDAY...SOUTHWEST WINDS IN PLACE THROUGH THE PERIOD.
THE MAIN FORECAST CHALLENGE APPEARS TO BE THE PROSPECTS OF A LATE
PERIOD APPROACHING COLD FRONT THAT COULD TIGHTEN THE GRADIENT. IF SO
THIS WILL TRANSLATE TO AN INCREASE IN WINDS AND SEAS...EVEN IF ONLY
A CATEGORY/1FT RESPECTIVELY. THE SPEED OF APPROACH OF THIS BOUNDARY
HAS DECREASE AND SO HAS FORECAST CONFIDENCE SLIGHTLY. WITH THE
CONTINUED APPROACH OF THE BOUNDARY ON SUNDAY THERE COULD BE ANOTHER
1 FT INCREASE IN SIG WAVE HEIGHT AND CAUTIONARY HEADLINES MAY BE
NEEDED OVER PARTS OF THE AREA. A WEAKER OR SLOWER SOLUTION WOULD
PRECLUDE THIS HOWEVER AND WOULD PREFER TO BE HESITANT TO ADD 5 FT
SEAS ANYWHERE AT THIS TIME.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RJD/TRA
SHORT TERM...RAN
LONG TERM...MBB
AVIATION...SGL/TRA
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
352 AM CDT WED AUG 15 2012
.DISCUSSION...
NOT TOO MUCH OF MENTION IN THE SHORT TERM...AN H5 SHORTWAVE IS
PROGGED TO BE PASSING OVER MIDDLE TN EARLY IN THE FIRST PERIOD AND
SHOULD BE CLEAR OF THE CUMBERLAND BY 18Z. RUC FORECAST SOUNDINGS
SHOW VERY MOIST MID AND UPPER LEVELS WITH ADEQUATE LIFT HOWEVER LOW
LEVEL DRYNESS SHOULD PREVENT ANYTHING FROM REACHING THE SURFACE. THE
CUMBERLAND MAY GET A SPRINKLE OR TWO BEFORE 16Z BUT OTHERWISE MID
AND UPPER LEVEL CLOUDINESS SHOULD BE THE ONLY RESULT. ONCE THESE
CLEARS OUT...HIGH PRESSURE...FROM THE SURFACE UP TO 700 MB...WILL
KEEP THE COLUMN DRY AND ALLOW FOR HIGHS TO WARM UP THROUGH THURSDAY.
AS FOR THE LONG TERM...THE FOCUS WILL BE ON AN APPROACHING COLD
FRONT AND ITS ASSOCIATED THUNDERSTORM POSSIBILITIES BY THURSDAY
NIGHT AND THROUGH SATURDAY MORNING. AS THE SURFACE HIGH CURRENTLY
OVER MIDDLE TN TRANSLATES EASTWARD...THE LOW LEVEL WIND FIELD WILL
RETURN TO THE SOUTH AND MOISTURE ADVECTION WILL BEGIN OVERNIGHT
WEDNESDAY. DURING THIS TIME...A PRE FRONTAL TROUGH WILL PASS ACROSS
NORTHERN KY WHICH WILL VEER LOW LEVEL WINDS NEARLY PARALLEL WITH THE
ADVANCING FRONT. THIS SHOULD LIMIT 0-6 KM BULK SHEAR VALUES AND GFS
SEEMS TO AGREE...ONLY SHOWING 20 KT OF UNIDIRECTIONAL SHEAR.
HOWEVER...250MB DIVERGENCE SHOULD BE STRONGEST COINCIDENT WITH THE
FRONT WHICH...COUPLED WITH MOIST ADIABATIC LAPSE RATES NEARLY
THROUGHOUT THE COLUMN WITHOUT A CAP...PW VALUES NEAR 1.75...AND CAPE
VALUES >1500 J/KG...THE INGREDIENTS FOR A SOME STRONG STORMS
EMBEDDED IN A LINE OF WIDESPREAD HEAVY RAIN ARE PRESENT.
DRY AIR BEHIND THE FRONT WILL CAUSE A RAPID DROP OFF IN COVERAGE BY
12Z SATURDAY. THE REST OF THE WEEKEND AND EARLY WORK WEEK SHOULD BE
QUITE PLEASANT WITH HIGHS IN THE LOWER 80S. BY MID
WEEK...TEMPERATURE SHOULD BEGIN TO RISE BACK TO MORE SEASONAL
NORMALS IN THE UPPER 80S.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 88 64 90 72 / 05 0 20 40
CLARKSVILLE 89 62 91 70 / 05 0 30 50
CROSSVILLE 82 59 84 66 / 10 05 10 30
COLUMBIA 88 64 90 71 / 05 0 20 40
LAWRENCEBURG 88 63 89 70 / 05 05 20 40
WAVERLY 89 63 91 70 / 05 0 30 50
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
TB12
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1140 PM CDT TUE AUG 14 2012
.SHORT TERM...TONIGHT THROUGH FRIDAY
300 PM CDT TUE AUG 14 2012
SHOWER/THUNDERSTORM CHANCES THROUGH THURSDAY AND TEMPERATURES ARE
THE MAIN CONCERN THROUGH THE SHORT TERM PERIOD.
LATEST WATER VAPOR IMAGERY ALONG WITH RAP 500MB HEIGHT ANALYSIS
SHOWS A COUPLE MID-LEVEL SHORTWAVE TROUGHS DROPPING THROUGH
NORTHWEST FLOW ALOFT ACROSS IA AND MN INTO NEBRASKA. MORE ENERGETIC
WAVE POISED TO AFFECT THE AREA IN THE NEXT 12-24 HOURS WAS MAKING
ITS WAY SOUTHEAST ACROSS THE ALBERTA ROCKIES. RADAR MOSAIC
SHOWING A BAND OF SCATTERED ELEVATED SHRA ACTIVITY ACROSS SOUTHEAST
ND INTO SOUTHWEST MN IN DECENT ISENTROPIC LIFT/MOISTURE TRANSPORT
AHEAD OF THE MN/NEB WAVE AND SURFACE WARM FRONT. MEANWHILE...
VISIBLE SATELLITE SHOWING AN EXPANSIVE FIELD OF CUMULUS ACROSS THE
LOCAL FORECAST AREA WITH INFLUENCE OF LINGERING COLD AIR ALOFT/STEEP
LAPSE RATES. TEMPERATURES ACROSS THE AREA AT 2 PM WERE IN THE 70S
TO LOWER 80S.
14.12Z NCEP MODELS/14.09Z SREF IN GOOD AGREEMENT WITH SYNOPTIC SETUP
THROUGH THE SHORT TERM PERIOD.
WILL BE WATCHING THE MN-NEB MID-LEVEL TROUGH AND SURFACE WARM FRONT
APPROACH THE AREA THIS EVENING/OVERNIGHT. NAM INDICATING
INCREASING/IMPRESSIVE 305K ISENTROPIC LIFT ALONG WITH STRONG
850-700MB FRONTOGENESIS/MOISTURE TRANSPORT AHEAD OF THE WARM FRONT
FOR ACCAS DEVELOPMENT ALONG WITH LIKELIHOOD OF SHRA/ISOLD T
ACTIVITY. BASED ON THIS SIGNAL...BUMPED POPS INTO 50-60 PERCENT
RANGE...WITH AREAS FROM LAKE CITY MN THROUGH LA CROSSE AND VIROQUA
LIKELY BEING THE AXIS OF HIGHEST PROBABILITIES. RIGHT NOW...IT
APPEARS THUNDER WILL BE ISOLATED IN NATURE WITH ELEVATED
CAPE/850-700MB ONLY APPROACHING 500J/KG.
GOOD CHANCE OF LINGERING SHRA/ISOLD THUNDER FOR AREAS ALONG/NORTH OF
I-94 WEDNESDAY MORNING AS THE WARM FRONT PUSHES THROUGH SOUTHEAST MN
INTO SOUTHWEST WI. APPEARS THE WARM FRONT WILL PUSH NORTHEAST OF THE
AREA BY AFTERNOON WITH THE AREA IN GENERAL WARM AIR ADVECTION AHEAD
OF A FAIRLY STRONG COLD FRONT PUSHING EAST ACROSS MN. KEPT SLIGHT
SHRA/TS CHANCES IN FOR AREAS ALONG/NORTHEAST OF I-94 THROUGH THE
AFTERNOON TO ACCOUNT FOR EXITING WARM FRONT. OTHERWISE...LOOK FOR
TEMPERATURES TO TOP OFF IN THE MIDDLE/UPPER 80S SOUTHWEST OF I-94
AND IN THE UPPER 70S/AROUND 80 NORTHEAST OF I-94 WITH MORE CLOUD
COVER THERE.
WILL HAVE TO WATCH FOR SEVERE POTENTIAL GOING INTO WEDNESDAY
EVENING. ANTICIPATING A FAIRLY SOLID LINE OF THUNDERSTORMS FIRING
ALONG THE COLD FRONT ACROSS MN INTO NORTHWEST IA BY LATER WEDNESDAY
AFTERNOON AS 0-3KM MUCAPE PUSH INTO THE 2500-5000J/KG RANGE ALONG
WITH AMPLE BULK SHEAR. THIS FRONT/LINE OF THUNDERSTORMS WILL BE
MOVING INTO THE AREA WEDNESDAY EVENING/OVERNIGHT. LINE SHOULD BE IN
A WEAKENING STATE OVERNIGHT AS CAPE WANES. HOWEVER..CANNOT RULE OUT
SEVERE HAIL/WIND THREAT FOR WESTERN PORTIONS OF THE FORECAST
AREA...MAINLY WEST OF A LINE FROM LAKE CITY AND ROCHESTER MN...TO
CHARLES CITY IA.
LOOK FOR THE COLD FRONT TO PUSH SOUTHEAST OF THE AREA BY THURSDAY
MORNING...TAKING THE BULK OF THE SHOWER/THUNDERSTORMS WITH IT.
HOWEVER...IT APPEARS A SECONDARY TROUGH/SURFACE REFLECTION OF
MID-LEVEL TROUGH LAGS THE COLD FRONT FOR SHRA/TS CHANCES LINGERING
THROUGH THE MORNING HOURS ACROSS THE ENTIRE AREA AND SOUTHEAST OF A
MAUSTON TO PRAIRIE DU CHIEN LINE DURING THE AFTERNOON.
MEANWHILE...VERY COLD AIR ALOFT/STEEPENING LAPSE RATES DURING THE
AFTERNOON ALSO EXPECTED TO KICK OFF QUITE A BIT OF CUMULUS ACROSS
THE REMAINDER OF THE AREA. HIGHS ON THURSDAY ONLY EXPECTED TO TOP
OFF IN THE UPPER 60S TO MIDDLE 70S.
THURSDAY NIGHT THROUGH FRIDAY WILL BE COOLER THAN NORMAL WITH DEEP
MID-LEVEL TROUGH DIGGING INTO THE CENTRAL CONUS/GREAT LAKES REGIONS.
CUMULUS FIELD SHOULD BE QUITE IMPRESSIVE FRIDAY AFTERNOON AS WELL
WITH THE COLD AIR ALOFT/STEEP LAPSE RATES. LOOK FOR LOWS IN THE
UPPER 40S/LOWER 50S THURSDAY NIGHT AND HIGHS ON FRIDAY IN THE UPPER
60S/LOWER 70S.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
300 PM CDT TUE AUG 14 2012
LATEST GFS/ECMWF SHOWING LONG WAVE TROUGH CARVED OUT ACROSS THE
UPPER MISSISSIPPI RIVER VALLEY/GREAT LAKES REGION. STEEP LAPSE RATES
WILL EXIST THROUGH THE PERIOD WITH MODELS SHOWING A SHORTWAVE TROUGH
DROPPING IN ACROSS THE AREA SATURDAY FOR A TRIGGER FOR ISOLATED SHRA
DEVELOPMENT. LOOKS LIKE ANOTHER INNOCUOUS EMBEDDED SHORTWAVE TROUGH
WITHIN THE LONG WAVE/COLD TROUGH MAY BE ENOUGH ON SUNDAY FOR ANOTHER
ROUND OF ISOLATED SHOWERS. TEMPERATURES WILL REMAIN COOLER THAN
NORMAL UNDER THE TROUGH WITH HIGHS SATURDAY/SUNDAY TOPPING OFF IN
THE UPPER 60S/LOWER 70S. LOOK FOR THE TROUGH AXIS TO MOVE EAST OF
THE AREA ON MONDAY WITH SOME RIDGING ALOFT FOR DRIER AND SLIGHT
WARMER CONDITIONS. HIGHS ON MONDAY EXPECTED TO BE IN THE LOW/MID 70S.
THE GFS/EC DIVERGE ON THEIR SOLUTION ON TUESDAY. THE GFS BRINGS A
WING OF WARM AIR ADVECTION -SHRA/TS ACTIVITY INTO THE AREA WHEREAS
THE ECMWF MAINTAINS DRY SCENARIO IN WARM AIR ADVECTION. WENT WITH
MODEL CONSENSUS WHICH YIELDS A SLIGHT CHANCE OF SHOWER AND
THUNDERSTORMS. OTHERWISE...HIGHS ON TUESDAY EXPECTED TO WARM INTO
THE UPPER 70S/LOWER 80S.
&&
.AVIATION...THROUGH 06Z THURSDAY
1140 PM CDT TUE AUG 14 2012
A BAND OF LIGHT RAIN SHOWERS CONTINUES TO TRACK THROUGH THE REGION
THOUGH CONDITIONS HAVE STAYED VFR. THIS MAIN BAND SHOULD PUSH OFF
TO THE EAST OF LSE WITH MORE SCATTERED SHOWERS EXPECTED THROUGH
THE REST OF THE NIGHT. NOT MUCH INSTABILITY TO WORK WITH...SO ANY
LIGHTNING STRIKES WILL BE FEW AND FAR BETWEEN.
CONDITIONS WILL STAY VFR THROUGH WEDNESDAY AS WINDS GO SOUTH-
SOUTHWEST AHEAD OF THE NEXT SYSTEM THAT WILL PULL A COLD FRONT
THROUGH OVERNIGHT INTO THURSDAY MORNING. WINDS WILL BECOME GUSTY
BY AFTERNOON WITH PEAK GUSTS IN THE 20-25KT RANGE.
GOING INTO THE EVENING/OVERNIGHT...THE MAIN QUESTION IS WITH THE
TIMING OF WHEN SHOWERS/THUNDERSTORMS WILL MOVE IN AHEAD OF A COLD
FRONT. THINKING THAT MUCH OF THE CONVECTION WILL BE WELL OUT AHEAD
OF THE ACTUAL COLD FRONT PASSAGE SO HAVE INCLUDED SOME VCTS IN RST
FOR AROUND 4Z THOUGH IT MAY END UP BEING LATER. FROPA LIKELY WILL
BE AFTER 6Z...SO HAVE NOT INCLUDED A WIND SHIFT WITH THESE TAFS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
300 PM CDT TUE AUG 14 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS ALBANY NY
1024 AM EDT WED AUG 15 2012
.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED TO CONTINUE ACROSS OUR REGION TODAY
AS A DISTURBANCE MOVES ACROSS LONG ISLAND AND SOUTHERN NEW ENGLAND
WITH MORE SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD IN
FROM THE OHIO VALLEY TONIGHT WITH FAIR AND DRY WEATHER FOR
THURSDAY AND THURSDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM...THE FORECAST AREA EXPERIENCED SOME SUBSIDENCE IN
THE WAKE OF THE SHORT-WAVE THAT PASSED THROUGH THIS MORNING.
HOWEVER...THE CLEARING IN THE SATELLITE PICTURE IS FILLING IN WITH
STRATUS UPSTREAM. THE FCST AREA WILL LOSING MOST OF ITS HEATING.
THE NEXT DISTURBANCE IN THE SW FLOW ALOFT IS APPROACHING FROM THE
OH VALLEY AND THE VIRGINIAS. THIS SHORT-WAVE TROUGH MAY REKINDLE
SOME SHOWERS AND STRONG THUNDERSTORMS ESPECIALLY SOUTH AND EAST OF
THE CAPITAL REGION IN THE AFTERNOON. THE NAM/GFS STILL SHOW THE
BEST SBCAPES OF 1000+ J/KG SOUTH OF KALB. THE DEEP SHEAR WEAKENS
AFTER 18Z TO 25 KTS OR LESS. WE WILL HAVE TO SEE IF ANY STRONG TO
MARGINALLY SEVERE STORMS MATERIALIZE. THE SLIGHT RISK MAY BE TOO
FAR NORTH AT THIS TIME. THE LATEST HRRR SHOWS CONVECTION
INCREASING AFTER 21Z. THE KALB SOUNDING ALSO HAS AN INVERSION
ABOVE 600 HPA. WE WILL CONTINUE TO MONITOR THE CONVECTIVE THREAT.
THE SOUTHERN 6 COUNTIES OF THE CWA ARE IN A SLIGHT RISK FOR SEVERE
WEATHER. THE MAIN THREAT WILL BE THE POTENTIAL FOR ISOLATED DOWNBURST
WINDS...ALTHOUGH WIND FIELDS ALOFT NOT VERY IMPRESSIVE WITH ONLY
60 KTS AT H3. WBZ HEIGHTS REMAIN QUITE HIGH UNTIL THIS EVENING
ABOVE 11 KFT ACRS THE SRN 6 COUNTIES UP UNTIL 00Z...SO HAIL
APPEARS OF LESSER CONCERN AT THIS POINT IN TIME.
FOR TONIGHT...ANY LINGERING CONVECTION WILL BE MAINLY CONFINED TO
THE FIRST HALF OF TONIGHT TAPERING OFF FROM SOUTHWEST TO
NORTHEAST AROUND OR SHORTLY AFTER MIDNIGHT. THE UPPER TROUGH AND
ASSOCIATED VORT AXIS IS EXPECTED TO MOVE THROUGH AFTER 06Z WITH
JUST A FEW LINGERING SHOWERS LATE TONIGHT ACRS FAR ERN PTN OF FA.
EXPECT HIGHS TODAY IN THE 70S TO LOWER 80S WITH LOWS TONIGHT IN
THE MID 50S TO LOWER 60S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
ON THURSDAY RIDGING BUILDS ACRS THE FA AT THE SURFACE AND ALOFT
AND SLIDES EAST OF THE FA THURSDAY NIGHT PROVIDING DRY AND
SEASONABLE CONDITIONS. EXPECT HIGHS ON THURSDAY IN THE UPPER 70S TO
LOW TO MID 80S WITH LOWS THURSDAY NIGHT IN THE MID 50S TO LOWER 60S.
A RELATIVELY STRONG COLD FRONT IS EXPECTED TO BEGIN MOVING
TOWARDS THE FA ON FRIDAY. THE BIG QUESTION AT THIS POINT IS HOW
FAST DOES IT MOVE THROUGH FA. THE NAM SUGGESTS THE FRONTAL
PASSAGE IS QUICK THROUGH OUR FA FRIDAY EVENING...WHILE THE ECMWF
IS SLOWEST WITH A WAVE DEVELOPING ON THE FRONT SLOWLY THE EASTWARD
PROGRESSION AND LINGERING THE PCPN INTO THE WEEKEND ESPECIALLY
ACRS THE FAR SOUTHEAST PORTION OF THE FA. EXPECT HIGHS ON FRIDAY
IN THE MID 70S TO MID 80S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE GREATEST CHANCES FOR SHOWERS AND THUNDERSTORMS FRIDAY NIGHT...BUT
LINGERING ISOLATED ACTIVITY THROUGH SATURDAY. COLD ADVECTION
POTENTIALLY BEGINNING SATURDAY...AND POTENTIAL LINGERING CLOUDS
AND ISOLATED RAIN ACTIVITY...HIGHS SATURDAY IN THE 70S...SOME
AROUND 70 IN THE SOUTHERN ADIRONDACKS.
BY LATE IN THE WEEKEND AND THROUGH THE BEGINNING OF NEXT WEEK...AN
OVERALL UPPER PATTERN SETS UP WITH A MEAN UPPER TROUGH OVER EASTERN
NORTH AMERICA. IN FACT...IF THIS PATTERN WERE TO SET UP IN THE
WINTER...WITH AN UPPER LOW IN THE VICINITY OF HUDSON BAY...IT COULD
FAVOR POTENTIAL EAST COAST SNOWSTORMS. BUT IT IS SUMMER...AND LITTLE
PIECES OF UPPER ENERGY ARE PREDICTED TO TRACK WITHIN THE SOUTHERN
PERIPHERY OF THE UPPER TROUGH...SUPPORTING OCCASIONAL PERIODS OF
SHOWERS AND STORMS AND OCCASIONAL PERIODS OF DRY WEATHER.
THIS FAR OUT INTO THE FUTURE...NEXT SUNDAY THROUGH TUESDAY...NOT
ENOUGH CONFIDENCE TO TRY TO TIME PERIODS OF RAIN AND DRY PERIODS...
SO LEAVING RAIN CHANCES OUT BUT CLOUDY PERIODS AND INTERVALS OF
CLOUDS AND SUN ARE SUGGESTED THROUGH THE PERIOD. STILL...WITH THE
COOLER BOUNDARY LAYER TEMPERATURES...AND THE POTENTIAL FOR LESS THAN
TOTAL SUNSHINE/CLEAR SKY THROUGH THE PERIOD...HIGHS A LITTLE BELOW
NORMAL SUNDAY THROUGH TUESDAY. HIGHS IN THE 70S...WITH SOME 60S
SOUTHERN ADIRONDACKS.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
SHOWERS AND THUNDERSTORMS HAVE MOVED EAST OF ALL TAF SITES THIS
MORNING...WITH JUST A FEW LIGHT SHOWERS REMAINING NEAR SRN VT.
VFR/MVFR VSBYS WILL REMAIN POSSIBLE THROUGH AROUND
14Z/WED...ALTHOUGH CAN NOT RULE OUT A BRIEF PERIOD OF IFR CIGS AT
KPSF AS MIXING DEVELOPS UNTIL 14Z. MAINLY VFR CONDITIONS WILL
CONTINUE INTO THE AFTERNOON...WITH THE EXCEPTION OF LOCALIZED
MVFR/IFR VSBYS/CIGS IN SCATTERED SHOWERS/TSTMS INTO EARLY TONIGHT.
A LULL IN THE SHOWERS AND THUNDERSTORMS IS EXPECTED IN THE MORNING.
SHOWERS AND THUNDERSTORMS WILL REDEVELOP THIS AFTERNOON INTO EARLY
TONIGHT WITH THE APPROACH OF A WEAK COLD FRONT AND UPPER LEVEL
DISTURBANCE.
ADDITIONAL AREAS OF MVFR/IFR VSBYS/CIGS MAY DEVELOP AFTER
05Z/THU...ESP AT KPSF AND KGFL...AND IN ANY OTHER AREAS WHICH
RECEIVED PRIOR RAINFALL.
OUTLOOK...
THU...MAINLY VFR. NO SIG WX EXP AT THIS TIME. CHC MVFR/IFR WITH
BR/FG AT NIGHT.
FRI...VFR/MVFR. CHC SHRA/TSRA.
SAT-SUN...VFR...NO SIG WX.
&&
.FIRE WEATHER...
WET FLAG CONDITIONS ARE EXPECTED THROUGH TONIGHT.
UNSETTLED WEATHER IS EXPECTED TO CONTINUE ACROSS OUR REGION TODAY
AS A DISTURBANCE MOVES ACROSS LONG ISLAND AND SOUTHERN NEW ENGLAND
WITH MORE SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD IN
FROM THE OHIO VALLEY TONIGHT WITH FAIR AND DRY WEATHER FOR
THURSDAY AND THURSDAY NIGHT.
RELATIVE HUMIDITIES ARE EXPECTED TO ONLY DROP TO 65 TO 80 PERCENT
TONIGHT...INCREASE TO 90 TO 100 PERCENT TONIGHT...AND DROP TO 0 TO
55 PERCENT ON THURSDAY.
WINDS ARE EXPECTED TO BE LIGHT AND VARIABLE AT 5 MPH OR LESS
TODAY AND TONIGHT AND WEST TO NORTHWEST AROUND 5 MPH ON THURSDAY.
&&
.HYDROLOGY...
NO MAJOR PROBLEMS ARE EXPECTED ON THE MAIN STEM RIVERS THE NEXT 5
DAYS.
TOTAL QPF FROM THE SHOWERS AND THUNDERSTORMS THROUGH THIS EVENING
WILL RANGE FROM HALF AN INCH TO AN INCH AND A HALF IN MOST AREAS
AND UP TO 3 INCHES ACROSS THE CENTRAL AND SOUTHERN
TACONICS...BERKSHIRES...PORTIONS OF THE MID HUDSON VALLEY AND
PORTIONS OF THE LITCHFIELD HILLS. IN THESE AREAS SOME PONDING OF
WATER ON ROADWAYS AS WELL AS FLOODING OF LOW LYING POORLY DRAINED
AREAS IS EXPECTED TO OCCUR. DRY WEATHER RETURNS FOR THURSDAY
BEFORE A COLD FRONT APPROACHES FOR FRIDAY INTO SATURDAY WITH
SCATTERED SHOWERS AND THUNDERSTORMS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...11/WASULA
NEAR TERM...11/WASULA
SHORT TERM...11
LONG TERM...NAS
AVIATION...KL/WASULA
FIRE WEATHER...11
HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS ALBANY NY
810 AM EDT WED AUG 15 2012
.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED TO CONTINUE ACROSS OUR REGION TODAY
AS A DISTURBANCE MOVES ACROSS LONG ISLAND AND SOUTHERN NEW ENGLAND
WITH MORE SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD IN
FROM THE OHIO VALLEY TONIGHT WITH FAIR AND DRY WEATHER FOR
THURSDAY AND THURSDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 645 AM...FIRST ROUND OF SHOWERS AND THUNDERSTORMS HAS ALL
BUT EXITED EXTREME EASTERN PORTION OF FA. EXPECT THERE WILL BE A
LULL IN THE CONVECTION FOR THE NEXT SEVERAL HOURS AND HAVE THUS
CUT BACK ON POPS CONSIDERABLY THROUGH MID MORNING. MORE SHOWERS
AND EMBEDDED THUNDERSTORMS ARE EXPECTED TO DEVELOP WITH SURFACE
HEATING LATER THIS MORNING INTO EARLY THIS AFTERNOON. HRRR COL MAX
REFLECTIVITY HAS CONVECTION DEVELOPING ACRS FA BTWN AND 18Z WITH
NUMEROUS SHOWERS AND EMBEDDED THUNDERSTORMS BY MID AFTERNOON.
MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY INTO TONIGHT AS
SURFACE LOW MOVES ACROSS LONG ISLAND AND SOUTHERN NEW ENGLAND
WHILE UPPER TROUGH PASSES THROUGH THE REGION OVERNIGHT. EXPECT A
SHORT LULL IN THE PCPN THIS MORNING BEFORE THETA E RIDGE H10-H8
STRENGTHENS AGAIN ACRS FA WITH PWATS IN THE 1.5 TO 1.67 INCH
RANGE...SHOWALTER INDICES MORE NEGATIVE THAN YESTERDAY AND
MLMUCAPES BTWN 1500 AND 2500 J/KG...POTENTIAL EXISTS FOR MORE
HEAVY DOWNPOURS.
THE SOUTHERN 6 COUNTIES OF THE CWA ARE IN A SLIGHT RISK FOR SEVERE
WEATHER AND THIS AREA HAS THE BEST CHANCE FOR LIMITED SURFACE
HEATING...BETTER SHEAR AND 0-3 KM HELICITY. THE MAIN THREAT
TO BE THE POTENTIAL FOR ISOLATED DOWNBURST WINDS...ALTHOUGH WIND
FIELDS ALOFT NOT VERY IMPRESSIVE WITH ONLY 60 KTS AT H3. WBZ
HEIGHTS REMAIN QUITE HIGH UNTIL THIS EVENING ABOVE 11 KFT ACRS THE
SRN 6 COUNTIES UP UNTIL 00Z...SO HAIL APPEARS OF LESSER CONCERN AT
THIS POINT IN TIME.
FOR TONIGHT...ANY LINGERING CONVECTION WILL BE MAINLY CONFINED TO
THE FIRST HALF OF TONIGHT TAPERING OFF FROM SOUTHWEST TO
NORTHEAST AROUND OR SHORTLY AFTER MIDNIGHT. THE UPPER TROUGH AND
ASSOCIATED VORT AXIS IS EXPECTED TO MOVE THROUGH AFTER 06Z WITH
JUST A FEW LINGERING SHOWERS LATE TONIGHT ACRS FAR ERN PTN OF FA.
EXPECT HIGHS TODAY IN THE 70S TO LOWER 80S WITH LOWS TONIGHT IN
THE MID 50S TO LOWER 60S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
ON THURSDAY RIDGING BUILDS ACRS THE FA AT THE SURFACE AND ALOFT
AND SLIDES EAST OF THE FA THURSDAY NIGHT PROVIDING DRY AND
SEASONABLE CONDITIONS. EXPECT HIGHS ON THURSDAY IN THE UPPER 70S TO
LOW TO MID 80S WITH LOWS THURSDAY NIGHT IN THE MID 50S TO LOWER 60S.
A RELATIVELY STRONG COLD FRONT IS EXPECTED TO BEGIN MOVING
TOWARDS THE FA ON FRIDAY. THE BIG QUESTION AT THIS POINT IS HOW
FAST DOES IT MOVE THROUGH FA. THE NAM SUGGESTS THE FRONTAL
PASSAGE IS QUICK THROUGH OUR FA FRIDAY EVENING...WHILE THE ECMWF
IS SLOWEST WITH A WAVE DEVELOPING ON THE FRONT SLOWLY THE EASTWARD
PROGRESSION AND LINGERING THE PCPN INTO THE WEEKEND ESPECIALLY
ACRS THE FAR SOUTHEAST PORTION OF THE FA. EXPECT HIGHS ON FRIDAY
IN THE MID 70S TO MID 80S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE GREATEST CHANCES FOR SHOWERS AND THUNDERSTORMS FRIDAY NIGHT...BUT
LINGERING ISOLATED ACTIVITY THROUGH SATURDAY. COLD ADVECTION
POTENTIALLY BEGINNING SATURDAY...AND POTENTIAL LINGERING CLOUDS
AND ISOLATED RAIN ACTIVITY...HIGHS SATURDAY IN THE 70S...SOME
AROUND 70 IN THE SOUTHERN ADIRONDACKS.
BY LATE IN THE WEEKEND AND THROUGH THE BEGINNING OF NEXT WEEK...AN
OVERALL UPPER PATTERN SETS UP WITH A MEAN UPPER TROUGH OVER EASTERN
NORTH AMERICA. IN FACT...IF THIS PATTERN WERE TO SET UP IN THE
WINTER...WITH AN UPPER LOW IN THE VICINITY OF HUDSON BAY...IT COULD
FAVOR POTENTIAL EAST COAST SNOWSTORMS. BUT IT IS SUMMER...AND LITTLE
PIECES OF UPPER ENERGY ARE PREDICTED TO TRACK WITHIN THE SOUTHERN
PERIPHERY OF THE UPPER TROUGH...SUPPORTING OCCASIONAL PERIODS OF
SHOWERS AND STORMS AND OCCASIONAL PERIODS OF DRY WEATHER.
THIS FAR OUT INTO THE FUTURE...NEXT SUNDAY THROUGH TUESDAY...NOT
ENOUGH CONFIDENCE TO TRY TO TIME PERIODS OF RAIN AND DRY PERIODS...
SO LEAVING RAIN CHANCES OUT BUT CLOUDY PERIODS AND INTERVALS OF
CLOUDS AND SUN ARE SUGGESTED THROUGH THE PERIOD. STILL...WITH THE
COOLER BOUNDARY LAYER TEMPERATURES...AND THE POTENTIAL FOR LESS THAN
TOTAL SUNSHINE/CLEAR SKY THROUGH THE PERIOD...HIGHS A LITTLE BELOW
NORMAL SUNDAY THROUGH TUESDAY. HIGHS IN THE 70S...WITH SOME 60S
SOUTHERN ADIRONDACKS.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
SHOWERS AND THUNDERSTORMS HAVE MOVED EAST OF ALL TAF SITES THIS
MORNING...WITH JUST A FEW LIGHT SHOWERS REMAINING NEAR SRN VT.
VFR/MVFR VSBYS WILL REMAIN POSSIBLE THROUGH AROUND
14Z/WED...ALTHOUGH CAN NOT RULE OUT A BRIEF PERIOD OF IFR CIGS AT
KPSF AS MIXING DEVELOPS UNTIL 14Z. MAINLY VFR CONDITIONS WILL
CONTINUE INTO THE AFTERNOON...WITH THE EXCEPTION OF LOCALIZED
MVFR/IFR VSBYS/CIGS IN SCATTERED SHOWERS/TSTMS INTO EARLY TONIGHT.
A LULL IN THE SHOWERS AND THUNDERSTORMS IS EXPECTED IN THE MORNING.
SHOWERS AND THUNDERSTORMS WILL REDEVELOP THIS AFTERNOON INTO EARLY
TONIGHT WITH THE APPROACH OF A WEAK COLD FRONT AND UPPER LEVEL
DISTURBANCE.
ADDITIONAL AREAS OF MVFR/IFR VSBYS/CIGS MAY DEVELOP AFTER
05Z/THU...ESP AT KPSF AND KGFL...AND IN ANY OTHER AREAS WHICH
RECEIVED PRIOR RAINFALL.
OUTLOOK...
THU...MAINLY VFR. NO SIG WX EXP AT THIS TIME. CHC MVFR/IFR WITH
BR/FG AT NIGHT.
FRI...VFR/MVFR. CHC SHRA/TSRA.
SAT-SUN...VFR...NO SIG WX.
&&
.FIRE WEATHER...
WET FLAG CONDITIONS ARE EXPECTED THROUGH TONIGHT.
UNSETTLED WEATHER IS EXPECTED TO CONTINUE ACROSS OUR REGION TODAY
AS A DISTURBANCE MOVES ACROSS LONG ISLAND AND SOUTHERN NEW ENGLAND
WITH MORE SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD IN
FROM THE OHIO VALLEY TONIGHT WITH FAIR AND DRY WEATHER FOR
THURSDAY AND THURSDAY NIGHT.
RELATIVE HUMIDITIES ARE EXPECTED TO ONLY DROP TO 65 TO 80 PERCENT
TONIGHT...INCREASE TO 90 TO 100 PERCENT TONIGHT...AND DROP TO 0 TO
55 PERCENT ON THURSDAY.
WINDS ARE EXPECTED TO BE LIGHT AND VARIABLE AT 5 MPH OR LESS
TODAY AND TONIGHT AND WEST TO NORTHWEST AROUND 5 MPH ON THURSDAY.
&&
.HYDROLOGY...
NO MAJOR PROBLEMS ARE EXPECTED ON THE MAIN STEM RIVERS THE NEXT 5
DAYS.
TOTAL QPF FROM THE SHOWERS AND THUNDERSTORMS THROUGH THIS EVENING
WILL RANGE FROM HALF AN INCH TO AN INCH AND A HALF IN MOST AREAS
AND UP TO 3 INCHES ACROSS THE CENTRAL AND SOUTHERN
TACONICS...BERKSHIRES...PORTIONS OF THE MID HUDSON VALLEY AND
PORTIONS OF THE LITCHFIELD HILLS. IN THESE AREAS SOME PONDING OF
WATER ON ROADWAYS AS WELL AS FLOODING OF LOW LYING POORLY DRAINED
AREAS IS EXPECTED TO OCCUR. DRY WEATHER RETURNS FOR THURSDAY
BEFORE A COLD FRONT APPROACHES FOR FRIDAY INTO SATURDAY WITH
SCATTERED SHOWERS AND THUNDERSTORMS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...11/WASULA
NEAR TERM...11
SHORT TERM...11
LONG TERM...NAS
AVIATION...KL/WASULA
FIRE WEATHER...11
HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS NEW YORK NY
714 AM EDT WED AUG 15 2012
.SYNOPSIS...
A WEAK LOW PRESSURE TROUGH WILL LINGER OVER THE REGION TODAY AND
HELP TRIGGER SCATTERED TO NUMEROUS THUNDERSTORMS INTO THIS
EVENING. THE TROUGH WILL THEN PASS TO THE EAST LATE WEDNESDAY
NIGHT. WEAK HIGH PRESSURE WILL BUILD ACROSS THURSDAY THROUGH
FRIDAY...THEN A SLOW MOVING COLD FRONT WILL MOVE ACROSS FRIDAY
NIGHT THROUGH SATURDAY. LOW PRESSURE DEVELOPING ALONG THE FRONT
WILL PASS THROUGH THE REGION OVER THE WEEKEND. HIGH PRESSURE WILL
THEN RETURN FOR THE NEW WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CONVECTION OVER THE LOCAL AREA IS CONFINED TO EASTERN CT...
NORTHERN LONG ISLAND AND LONG ISLAND SOUND. PEAK WIND GUSTS FROM
TSTMS HAS BEEN AROUND 30 MPH...BUT CANNOT RULE OUT AN ISOLATED SVR
TSTM BEFORE STORMS FINALLY DEPART. SOME OF THE HEAVIER AREAS OF
RAIN PRODUCED AN INCH OF QPF IN AN HOUR...AND WHERE THIS
HAPPENS...MINOR FLOODING OF LOW-LYING AND POOR DRAINAGE AREAS CAN
BE EXPECTED.
THERE WILL BE A BREAK IN CONVECTION FROM THIS MORNING THROUGH THIS
AFTERNOON...AND TSTMS WILL BECOME NUMEROUS IN COVERAGE...
ESPECIALLY LATE THIS AFTERNOON AND THIS EVENING AS A VIGOROUS MID
LEVEL SHORTWAVE TROUGH APPROACHES FROM THE OH VALLEY AND PHASES
WITH ANOTHER APPROACHING UPPER TROUGH TO ITS NORTH. CONCUR WITH
SPC DAY 1 SLIGHT RISK FOR ENTIRE CWA...WITH PULSE/MULTICELL
CONVECTION CAPABLE OF PRODUCING DAMAGING WIND GUSTS...ALSO
FREQUENT LIGHTNING...AND HEAVY RAIN AS PW REMAINS NEAR 1.75 INCHES
AND CORFIDI VECTORS INDICATE POTENTIAL FOR BACK-BUILDING OF STORM
CLUSTERS AND TRAINING OF CELLS.
CONVECTIVE THREAT SHOULD SHIFT TO THE EAST AND WANE LATER
TONIGHT...WITH PATCHY FOG POSSIBLE WHERE HEAVY RAIN HAS FALLEN.
HIGH TEMPS TODAY WILL BE IN THE 80S...WITH LOWS TONIGHT IN THE 60S
TO LOWER 70S...CLOSE TO A 00Z MAV/MET GUIDANCE BLEND.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
LAST OF THE CONVECTION MAY STILL BE CLEARING ERN SECTIONS EARLY IN
THE MORNING PER SLOWER 00Z AS COMPARED TO THE GFS. OTHERWISE...EXPECT
DRY CONDITIONS...WITH PLENTY OF SUNSHINE AND ONLY SOME FAIR WX
CU...WITH SLIGHTLY WARMER TEMPS IN THE MID AND UPPER 80S...BUT
WITH LOWER DEWPOINTS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
HIGH PRES OVER THE AREA DEPARTS FRIDAY MORNING...THEN A SLOW MOVING
COLD FRONT APPROACHES FROM THE WEST. SHOWERS AND THUNDERSTORMS AHEAD
OF THE FRONT WILL ENTER THE REGION FROM WEST TO EAST DURING THE DAY
ON FRIDAY. SHOWERS AND THUNDERSTORMS WILL BECOME MORE WIDESPREAD
OVER THE AREA FRIDAY NIGHT INTO SATURDAY AS THE COLD FRONT MOVES
CLOSER AND HAS UPPER LEVEL SUPPORT FROM AN H5 TROUGH AND MID-LEVEL
SHORTWAVES.
THEREAFTER...LOW CONFIDENCE FORECAST FOR THE WEEKEND AS THE MODELS
HAVE DIFFERENT SOLUTIONS. LOW PRES FORMS OVER THE DELMARVA SOMETIME
EARLY SATURDAY...THEN TRACKS NORTHEAST ALONG THE FRONT. THE GFS
BRINGS THE FRONT THROUGH THE REGION MUCH QUICKER THAN THE ECMWF...
AND KEEPS THE LOW EAST OF THE REGION. THE ECMWF BRINGS THE LOW OVER
THE AREA DURING THE DAY SATURDAY INTO SATURDAY NIGHT. PRECIPITATION
WOULD THEN LINGER INTO SUNDAY AS H5 TROUGH FOLLOWS THROUGH THE
REGION. WILL CARRY CHANCE POPS FOR MOST OF THE WEEKEND...BUT THIS IS
SUBJECT TO ADJUSTMENTS.
LOCALLY HEAVY RAIN IS POSSIBLE WITH PWATS AROUND 2" STARTING ON
FRIDAY.
HIGH PRES BEGINS TO BUILD INTO THE REGION STARTING ON SUNDAY. PRECIP
TAPERS OFF FROM WEST TO EAST...THOUGH A FEW LINGERING SHOWERS AND
POSSIBLE THUNDERSTORMS ARE POSSIBLE THROUGH MONDAY AS UPPER TROUGH
AND H5 SHORTWAVES TRACK ACROSS THE REGION. DRY WEATHER EXPECTED BY
FRIDAY WITH HIGH PRES BUILDING EAST.
SOUTHERLY FLOW ON FRIDAY WILL PUSH TEMPS INTO THE MID-UPPER 80S AND
MAY COME CLOSE TO 90 IN/AROUND NYC. OTHERWISE...HIGHS WILL BE IN THE
UPPER 70S TO LOWER 80S DURING THE PERIOD...WHICH IS RIGHT AROUND
NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION /11Z WEDNESDAY THROUGH SUNDAY/...
UPPER LEVEL DISTURBANCE CURRENTLY MOVING THROUGH THE REGION. WEAK
LOW PRES OVER NJ WILL SLOWLY LIFT TOWARDS NYC TODAY AND THEN PASS
OVER OR JUST SOUTH OF THE AREA TONIGHT.
SCT TSTMS WILL LIFT NE EARLY THIS MORNING. COULD SEE ADDITIONAL
CELLS DEVELOP THROUGH 12Z MAINLY OVER EASTERN TERMINALS WHICH
WOULD WARRANT QUICK AMENDMENTS. LATEST HRRR KEEPS STORMS E OF NYC
THIS MORNING AND THEN FIRES THEM UP AGAIN THIS AFTN WITH
INCREASING INSTABILITY WHICH FITS CURRENT THINKING.
GENERALLY VFR CONDS THROUGH THE PERIOD...ALTHOUGH SCT V BKN MVFR
CIGS POSSIBLE EARLY. MVFR TO LOCALLY IFR CONDS IN SHRA/TSTM
ACTIVITY THIS AFTN AND EVE. BEST TIMING FOR CONVECTION WILL BE
BETWEEN 17Z AND 21Z ACROSS WESTERN TERMINALS AND 20Z TO 00Z AT
EASTERN TERMINALS. SOME OF THIS ACTIVITY MAY LINGER BEYOND THIS
TIME FRAME AS THE LOW AND UPPER LEVEL TROUGH SLOWLY PASSES THROUGH
BUT CONFIDENCE IS LOW ATTM SO HAVE ONLY KEPT -SHRA IN THE
FORECAST.
WINDS ARE EXPECTED TO BACK TO THE SE THIS MORNING AND REMAIN BLO
10 KT THROUGH THE FORECAST PERIOD. WITH THE SFC LOW PRES NEAR THE
AREA TODAY...DIRECTIONS BECOME TROUBLESOME AND HIGHLY UNCERTAIN AFT
18Z.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: LOW CONFIDENCE IN WIND FORECAST AFT 18Z.
TSTMS MAY CONTINUE INTO THE EVE.
KLGA FCSTER COMMENTS: LOW CONFIDENCE IN WIND FORECAST AFT 18Z.
TSTMS MAY CONTINUE INTO THE EVE.
KEWR FCSTER COMMENTS: LOW CONFIDENCE IN WIND FORECAST AFT 18Z.
TSTMS MAY CONTINUE INTO THE EVE.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: LOW CONFIDENCE IN WIND FORECAST AFT 18Z.
TSTMS MAY CONTINUE INTO THE EVE.
KHPN FCSTER COMMENTS: TSTMS MAY CONTINUE INTO THE EVE.
KISP FCSTER COMMENTS: TSTMS MAY CONTINUE INTO THE EVE.
OUTLOOK FOR 06Z THURSDAY THROUGH SATURDAY...
.WED NIGHT...MVFR CONDITIONS WITH ANY SHRA/TSRA...MAINLY EASTERN
TERMINALS. PATCHY MVFR FOG ALSO POSSIBLE OUTSIDE OF NYC TERMINALS.
.THU...VFR. NW FLOW.
.FRI...TSTMS (POSSIBLE LINE) LATE FRI AFTN INTO OVERNIGHT WITH
PASSAGE OF A COLD FRONT.
.SAT-SUN...VFR. N-NW FLOW.
&&
.MARINE...
PREVAILING SUB-SCA CONDS EXPECTED THROUGH THE WEEKEND.
THUNDERSTORMS TROUGH TONIGHT AND AGAIN FRIDAY AFTERNOON THROUGH
SUNDAY COULD RESULT IN LOCALLY REDUCED VSBY AND WIND GUSTS OVER
35 KT.
&&
.HYDROLOGY...
BASIN AVG QPF THROUGH WED NIGHT SHOULD RANGE FROM 3/4 TO 1 1/4
INCH...HIGHER OVER LONG ISLAND AND CT. LOCALLY HIGHER AMOUNTS OVER
2 INCHES ARE POSSIBLE. FLASH FLOOD THREAT IS LOW TO MODERATE...AND
MAY EVENTUALLY REQUIRE A SHORT FUSED WATCH FOR THIS AFTERNOON
AND EVENING.
A SLOW MOVING COLD FRONT WILL MOVE ACROSS FROM FRIDAY AFTERNOON
THROUGH EARLY SATURDAY...THEN LOW PRES MAY IMPACT THE REGION
SATURDAY THROUGH SUNDAY. PW VALUES NEAR 2 INCHES AHEAD OF THE FRONT
WILL BRING AN ELEVATED THREAT OF HEAVY RAIN...WHICH COULD RESULT IN
MINOR FLOODING IN SOME AREAS.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GOODMAN/MPS
NEAR TERM...GOODMAN/MPS
SHORT TERM...GOODMAN
LONG TERM...MPS
AVIATION...
MARINE...GOODMAN/MPS
HYDROLOGY...GOODMAN/MPS
AREA FORECAST DISCUSSION
NWS ALBANY NY
656 AM EDT WED AUG 15 2012
.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED TO CONTINUE ACROSS OUR REGION TODAY
AS A DISTURBANCE MOVES ACROSS LONG ISLAND AND SOUTHERN NEW ENGLAND
WITH MORE SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD IN
FROM THE OHIO VALLEY TONIGHT WITH FAIR AND DRY WEATHER FOR
THURSDAY AND THURSDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 645 AM...FIRST ROUND OF SHOWERS AND THUNDERSTORMS HAS ALL
BUT EXITED EXTREME EASTERN PORTION OF FA. EXPECT THERE WILL BE A
LULL IN THE CONVECTION FOR THE NEXT SEVERAL HOURS AND HAVE THUS
CUT BACK ON POPS CONSIDERABLY THROUGH MID MORNING. MORE SHOWERS
AND EMBEDDED THUNDERSTORMS ARE EXPECTED TO DEVELOP WITH SURFACE
HEATING LATER THIS MORNING INTO EARLY THIS AFTERNOON. HRRR COL MAX
REFLECTIVITY HAS CONVECTION DEVELOPING ACRS FA BTWN AND 18Z WITH
NUMEROUS SHOWERS AND EMBEDDED THUNDERSTORMS BY MID AFTERNOON.
MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY INTO TONIGHT AS
SURFACE LOW MOVES ACROSS LONG ISLAND AND SOUTHERN NEW ENGLAND
WHILE UPPER TROUGH PASSES THROUGH THE REGION OVERNIGHT. EXPECT A
SHORT LULL IN THE PCPN THIS MORNING BEFORE THETA E RIDGE H10-H8
STRENGTHENS AGAIN ACRS FA WITH PWATS IN THE 1.5 TO 1.67 INCH
RANGE...SHOWALTER INDICES MORE NEGATIVE THAN YESTERDAY AND
MLMUCAPES BTWN 1500 AND 2500 J/KG...POTENTIAL EXISTS FOR MORE
HEAVY DOWNPOURS.
THE SOUTHERN 6 COUNTIES OF THE CWA ARE IN A SLIGHT RISK FOR SEVERE
WEATHER AND THIS AREA HAS THE BEST CHANCE FOR LIMITED SURFACE
HEATING...BETTER SHEAR AND 0-3 KM HELICITY. THE MAIN THREAT
TO BE THE POTENTIAL FOR ISOLATED DOWNBURST WINDS...ALTHOUGH WIND
FIELDS ALOFT NOT VERY IMPRESSIVE WITH ONLY 60 KTS AT H3. WBZ
HEIGHTS REMAIN QUITE HIGH UNTIL THIS EVENING ABOVE 11 KFT ACRS THE
SRN 6 COUNTIES UP UNTIL 00Z...SO HAIL APPEARS OF LESSER CONCERN AT
THIS POINT IN TIME.
FOR TONIGHT...ANY LINGERING CONVECTION WILL BE MAINLY CONFINED TO
THE FIRST HALF OF TONIGHT TAPERING OFF FROM SOUTHWEST TO
NORTHEAST AROUND OR SHORTLY AFTER MIDNIGHT. THE UPPER TROUGH AND
ASSOCIATED VORT AXIS IS EXPECTED TO MOVE THROUGH AFTER 06Z WITH
JUST A FEW LINGERING SHOWERS LATE TONIGHT ACRS FAR ERN PTN OF FA.
EXPECT HIGHS TODAY IN THE 70S TO LOWER 80S WITH LOWS TONIGHT IN
THE MID 50S TO LOWER 60S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
ON THURSDAY RIDGING BUILDS ACRS THE FA AT THE SURFACE AND ALOFT
AND SLIDES EAST OF THE FA THURSDAY NIGHT PROVIDING DRY AND
SEASONABLE CONDITIONS. EXPECT HIGHS ON THURSDAY IN THE UPPER 70S TO
LOW TO MID 80S WITH LOWS THURSDAY NIGHT IN THE MID 50S TO LOWER 60S.
A RELATIVELY STRONG COLD FRONT IS EXPECTED TO BEGIN MOVING
TOWARDS THE FA ON FRIDAY. THE BIG QUESTION AT THIS POINT IS HOW
FAST DOES IT MOVE THROUGH FA. THE NAM SUGGESTS THE FRONTAL
PASSAGE IS QUICK THROUGH OUR FA FRIDAY EVENING...WHILE THE ECMWF
IS SLOWEST WITH A WAVE DEVELOPING ON THE FRONT SLOWLY THE EASTWARD
PROGRESSION AND LINGERING THE PCPN INTO THE WEEKEND ESPECIALLY
ACRS THE FAR SOUTHEAST PORTION OF THE FA. EXPECT HIGHS ON FRIDAY
IN THE MID 70S TO MID 80S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE GREATEST CHANCES FOR SHOWERS AND THUNDERSTORMS FRIDAY NIGHT...BUT
LINGERING ISOLATED ACTIVITY THROUGH SATURDAY. COLD ADVECTION
POTENTIALLY BEGINNING SATURDAY...AND POTENTIAL LINGERING CLOUDS
AND ISOLATED RAIN ACTIVITY...HIGHS SATURDAY IN THE 70S...SOME
AROUND 70 IN THE SOUTHERN ADIRONDACKS.
BY LATE IN THE WEEKEND AND THROUGH THE BEGINNING OF NEXT WEEK...AN
OVERALL UPPER PATTERN SETS UP WITH A MEAN UPPER TROUGH OVER EASTERN
NORTH AMERICA. IN FACT...IF THIS PATTERN WERE TO SET UP IN THE
WINTER...WITH AN UPPER LOW IN THE VICINITY OF HUDSON BAY...IT COULD
FAVOR POTENTIAL EAST COAST SNOWSTORMS. BUT IT IS SUMMER...AND LITTLE
PIECES OF UPPER ENERGY ARE PREDICTED TO TRACK WITHIN THE SOUTHERN
PERIPHERY OF THE UPPER TROUGH...SUPPORTING OCCASIONAL PERIODS OF
SHOWERS AND STORMS AND OCCASIONAL PERIODS OF DRY WEATHER.
THIS FAR OUT INTO THE FUTURE...NEXT SUNDAY THROUGH TUESDAY...NOT
ENOUGH CONFIDENCE TO TRY TO TIME PERIODS OF RAIN AND DRY PERIODS...
SO LEAVING RAIN CHANCES OUT BUT CLOUDY PERIODS AND INTERVALS OF
CLOUDS AND SUN ARE SUGGESTED THROUGH THE PERIOD. STILL...WITH THE
COOLER BOUNDARY LAYER TEMPERATURES...AND THE POTENTIAL FOR LESS THAN
TOTAL SUNSHINE/CLEAR SKY THROUGH THE PERIOD...HIGHS A LITTLE BELOW
NORMAL SUNDAY THROUGH TUESDAY. HIGHS IN THE 70S...WITH SOME 60S
SOUTHERN ADIRONDACKS.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
A WARM FRONT APPROACHING FROM THE SOUTHWEST OVERNIGHT WILL TRIGGER
NUMEROUS SHOWERS AND THUNDERSTORMS. SHOWERS AND THUNDERSTORMS MAY
BRIEFLY DIMINISH LATER THIS MORNING...BUT MORE SHOULD DEVELOP WITH
THE APPROACH OF A WEAK COLD FRONT AND UPPER LEVEL DISTURBANCE
LATER THIS AFTERNOON AND TONIGHT.
SEVERAL CLUSTERS OF SHOWERS AND THUNDERSTORMS APPROACHING FROM THE
SOUTHWEST WILL AFFECT THE TAF SITES THROUGH DAYBREAK...WITH
PERIODS OF MVFR TO IFR VSBYS/CIGS. LOCALLY HEAVY RAINFALL WILL OCCUR.
THE SHOWERS AND THUNDERSTORMS SHOULD DECREASE IN AREAL COVERAGE
SHORTLY AFTER DAYBREAK...WITH MAINLY VFR CONDITIONS DEVELOPING.
ADDITIONAL SCATTERED SHOWERS AND THUNDERSTORMS WILL REDEVELOP
LATER THIS AFTERNOON INTO EARLY TONIGHT...WITH POCKETS OF MVFR/IFR
VSBYS/CIGS POSSIBLE.
OUTLOOK...
THU...MAINLY VFR. NO SIG WX EXP AT THIS TIME. CHC MVFR/IFR WITH
BR/FG AT NIGHT.
FRI...VFR/MVFR. CHC SHRA/TSRA.
SAT-SUN...VFR...NO SIG WX.
&&
.FIRE WEATHER...
WET FLAG CONDITIONS ARE EXPECTED THROUGH TONIGHT.
UNSETTLED WEATHER IS EXPECTED TO CONTINUE ACROSS OUR REGION TODAY
AS A DISTURBANCE MOVES ACROSS LONG ISLAND AND SOUTHERN NEW ENGLAND
WITH MORE SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD IN
FROM THE OHIO VALLEY TONIGHT WITH FAIR AND DRY WEATHER FOR
THURSDAY AND THURSDAY NIGHT.
RELATIVE HUMIDITIES ARE EXPECTED TO ONLY DROP TO 65 TO 80 PERCENT
TONIGHT...INCREASE TO 90 TO 100 PERCENT TONIGHT...AND DROP TO 0 TO
55 PERCENT ON THURSDAY.
WINDS ARE EXPECTED TO BE LIGHT AND VARIABLE AT 5 MPH OR LESS
TODAY AND TONIGHT AND WEST TO NORTHWEST AROUND 5 MPH ON THURSDAY.
&&
.HYDROLOGY...
NO MAJOR PROBLEMS ARE EXPECTED ON THE MAIN STEM RIVERS THE NEXT 5
DAYS.
TOTAL QPF FROM THE SHOWERS AND THUNDERSTORMS THROUGH THIS EVENING
WILL RANGE FROM HALF AN INCH TO AN INCH AND A HALF IN MOST AREAS
AND UP TO 3 INCHES ACROSS THE CENTRAL AND SOUTHERN
TACONICS...BERKSHIRES...PORTIONS OF THE MID HUDSON VALLEY AND
PORTIONS OF THE LITCHFIELD HILLS. IN THESE AREAS SOME PONDING OF
WATER ON ROADWAYS AS WELL AS FLOODING OF LOW LYING POORLY DRAINED
AREAS IS EXPECTED TO OCCUR. DRY WEATHER RETURNS FOR THURSDAY
BEFORE A COLD FRONT APPROACHES FOR FRIDAY INTO SATURDAY WITH
SCATTERED SHOWERS AND THUNDERSTORMS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...BGM/11/WASULA
NEAR TERM...11
SHORT TERM...11
LONG TERM...NAS
AVIATION...KL
FIRE WEATHER...11
HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1111 AM EDT WED AUG 15 2012
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE AND ASSOCIATED COLD FRONT WILL MOVE IN
FROM THE WEST THIS AFTERNOON AND EVENING. THE FRONT WILL CONTINUE
TO SLOWLY MOVE SOUTHEAST BEFORE DISSIPATING ALONG THE COAST ON
THURSDAY. A STRONGER COLD FRONT WILL APPROACH FROM THE NORTHWEST
ON FRIDAY THEN LINGER ALONG THE SOUTHEAST COAST THROUGH EARLY NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AREA OF STRATUS EARLIER THIS MORNING HAS EXPANDED EASTWARD INTO
THE REGION. LOWER CLOUDS/STRATUS WILL MIX AND DECREASE A BIT IN
COVERAGE AS HEATING INCREASES...AND STILL EXPECT AT LEAST PARTLY
SUNNY CONDITIONS FOR MUCH OF THE AREA THIS AFTERNOON.
BIG QUESTION TODAY IS DECIDING WHAT THE PROBABILITY IS FOR
ISOLATED SEVERE STORMS THIS AFTERNOON. LATEST UPDATE FROM SPC HAS
ALL OF OUR SC REGION IN A SLIGHT RISK FOR THIS AFTERNOON. THERE IS
SOME UPPER SUPPORT FOR STRONG TO SEVERE THUNDERSTORMS THIS
AFTERNOON IN THE FORM OF A SHORT WAVE TROF...WHICH IS EXPECTED TO
MOVE ACROSS NC AND VA TODAY. OUR NORTHERN AREA WILL BE UNDER THE
INFLUENCE OF THE TAIL END OF THIS SHORT WAVE...ALONG WITH THE
ENTRANCE REGION OF A 70-75 KT UPPER JET. THIS UPPER SUPPORT
COMBINED WITH CAPE VALUES OF 2000-2500 J/KG WILL ALLOW FOR THE
THREAT FOR ISOLATED SEVERE STORMS THIS AFTERNOON...ESPECIALLY OVER
OUR SC ZONES. ONE LIMITING FACTOR IS THAT DEEP LAYER MOISTURE IS
MARGINAL...WHICH SHOULD HELP TO CUT DOWN ON THE OVERALL COVERAGE
OF CONVECTION. THUS...HAVE KEPT LOW END CHANCE POPS AT BEST OVER
THE SC ZONES FOR THIS AFTERNOON...WITH SLIGHT CHANCE REST OF REGION.
ALREADY SEEING SOME SCATTERED SHOWERS MOVING INTO OUR SE GA
ZONES...WHICH IS SUPPORTED BY THE LATEST HRRR MODEL RUN.
HOWEVER...THINK A BROKEN LINE OF STRONGER CONVECTION WILL FIRE
INLAND AHEAD OF THE APPROACHING SHORT WAVE AND ASSOCIATED SFC
TROUGH/WEAK FRONT OVER THE INTERIOR SC/GA ZONES THIS AFTERNOON.
THIS AREA OF CONVECTION WILL THEN MOVE ESE TOWARD THE COAST...THEN
WEAKEN/DISSIPATE BY LATER THIS EVENING OVER THE ATLANTIC WATERS.
HAVE CONTINUED TO KEEP OUT MENTION OF SEVERE WORDING IN THE GRIDS
AND TEXT FORECASTS DUE TO EXPECTED LOWER COVERAGE. HOWEVER...THE HWO
WILL CONTINUE TO HIGHLIGHT THREAT FOR ISOLATED SEVERE STORMS THIS
AFTERNOON...WITH THE MAIN THREATS BEING STRONG STRAIGHT LINE WINDS
AND SOME HAIL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
CONVECTION SHOULD BE MOVING OFF THE COAST THIS EVENING WITH
DIMINISHING RAIN CHANCES OVER LAND. THE WEAK COLD FRONT WILL DROP
SOUTHEAST THROUGH THE NIGHT WITH SOME COOLER AIR ALLOWING TEMPS TO
DROP INTO THE UPPER 60S INLAND.
THURSDAY...A WEAK COLD FRONT APPEARS TO BE POSITIONED ACROSS THE
FORECAST AREA AT THE START OF THE DAY. AS AN UPPER LEVEL TROUGH
PUSHES FARTHER OFFSHORE INTO THE ATLANTIC...THE COLD FRONT WILL DROP
SOUTH AND EAST OF THE AREA AND DISSIPATE. TO THE NORTH OF THE
FRONT...THE LOW LEVEL FLOW ACTUALLY TIPS NORTHWESTERLY AND THE
RESULTING DOWNSLOPE FLOW WILL AID IN DRYING AND WARMING THE AIRMASS.
ALONG AND SOUTH OF THE BOUNDARY...DEEPER MOISTURE AND A WEAK PASSING
SHORT WAVE ALOFT COULD BE SUFFICIENT TO SUPPORT ISOLATED
CONVECTION...MAINLY ALONG AND SOUTH OF THE I-16 CORRIDOR.
TEMPERATURES SHOULD GENERALLY REACH HIGHS IN THE MID 90S INLAND AND
LOWER 90S CLOSER TO THE COAST. A PINNED SEA BREEZE SHOULD RESULT IN
WARMER TEMPERATURES EVEN ALONG THE IMMEDIATE COAST.
THURSDAY NIGHT...ISOLATED CONVECTION COULD CONTINUE INTO THE EVENING
HOURS ALONG AND SOUTH OF THE I-16 CORRIDOR...BEFORE THE FOCUS SHIFTS
OFFSHORE DURING THE LATE EVENING AND OVERNIGHT HOURS. LOWS WILL BE
IN THE LOWER TO MID 70S.
FRIDAY AND FRIDAY NIGHT...AN UPPER LEVEL TROUGH WILL BEGIN TO DIG
WEST OF THE REGION AND PUSH A COLD FRONT TOWARD THE AREA. AHEAD OF
THE FRONT...A SOUTHWEST LOW LEVEL FLOW WILL BECOME ESTABLISHED
ALLOWING DEEP LAYER MOISTURE TO INCREASE ACROSS THE AREA. EXPECT
MAINLY DIURNAL CONVECTION...WITH THE FORECAST INDICATING A CHANCE OF
SHOWERS AND THUNDERSTORMS. HIGHS WILL REMAIN IN THE LOWER TO MID 90S
WITH NIGHTTIME LOWS IN THE LOWER TO MID 70S.
SATURDAY...BROAD UPPER LEVEL TROUGHING WILL SETTLE OVER MUCH OF THE
EASTERN UNITED STATES...WITH SEVERAL WAVES OF LOW PRESSURE HANGING
THE COLD FRONT UP NEAR OR OVER PARTS OF THE AREA. THE PROXIMITY OF
THE FRONT COMBINED WITH THE PRESENCE OF DEEP LAYERED MOISTURE WILL
SUPPORT KEEPING A CHANCE OF SHOWERS AND THUNDERSTORMS IN THE
FORECAST. TEMPERATURES COULD MODERATE SOME WITH EXTENSIVE CLOUD
COVER POSSIBLE...WITH HIGHS IN THE LOWER 90S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
MEDIUM RANGE GUIDANCE IS IN GOOD AGREEMENT INDICATING AN UNSETTLED
PATTERN FOR MOST OF THE LONG TERM PERIOD. BROAD UPPER LEVEL
TROUGHING WILL PERSIST ACROSS THE EASTERN UNITED STATES INTO THE
MIDDLE OF NEXT WEEK...WITH A COLD FRONT GETTING HUNG UP ALONG THE
SOUTHEAST COAST. SEVERAL WAVES OF LOW PRESSURE PASSING ALONG THE
FRONT WILL CAUSE THE FRONT TO OSCILLATE BACK AND FORTH ACROSS THE
AREA THROUGH MOST OF THE PERIOD. CHANNELED VORTICITY ALONG THE
EASTERN PERIPHERY OF THE TROUGH COMBINED WITH AN AXIS OF DEEP
MOISTURE OVER THE AREA WILL RESULT IN A SOLID CHANCE OF SHOWERS AND
THUNDERSTORMS THROUGH THE MIDDLE OF NEXT WEEK. HIGH TEMPERATURES
WILL TREND SLIGHTLY BELOW NORMAL THROUGH THE LONG TERM PERIOD.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
HAVE UPDATED BOTH TAFS FOR STRATUS DECK THAT HAS EXPECTED EASTWARD
INTO THE AREA. EXPECT MVFR CIGS WILL BE AROUND THROUGH EARLY
AFTERNOON...THEN GENERALLY INCREASE BACK TO VFR LEVELS WITH
HEATING. SCATTERED SHOWERS/THUNDERSTORMS EXPECTED LATER THIS
AFTERNOON...ESPECIALLY FOR KCHS. THERE IS A THREAT FOR ISOLATED
SEVERE STORMS...WITH STRONG STRAIGHT LINE WINDS AND SOME HAIL.
HAVE MAINTAINED VCTS FOR KCHS FOR NOW...BUT EXPECT THE TAFS GET
MORE PESSIMISTIC WITH THE 18Z PACKAGE AS TREND FOR CONVECTION
BECOMES MORE EVIDENT.
EXTENDED AVIATION OUTLOOK...SCATTERED SHOWERS AND THUNDERSTORMS...
MAINLY DURING THE AFTERNOON/EVENING HOURS...COULD RESULT IN
TEMPORARY REDUCTIONS IN CIGS/VSBYS FRIDAY THROUGH SUNDAY.
OTHERWISE...VFR CONDITIONS ARE EXPECTED TO PREVAIL.
&&
.MARINE...
NO SIGNIFICANT CHANGES WERE MADE WITH THE MORNING UPDATE. STILL
EXPECT WINDS TO BE 15 KTS OR LESS TODAY WITH SEAS 3 FEET OR LESS.
SCATTERED SHOWERS AND THUNDERSTORM POSSIBLE...MAINLY LATER THIS
AFTERNOON AND EVENING AS A WEAK FRONT APPROACHES THE AREA FROM THE
WEST.
A STRONGER COLD FRONT IS THEN EXPECTED TO APPROACH FROM THE
NORTHWEST ON FRIDAY AND STALL ALONG THE SOUTHEAST COAST INTO EARLY
NEXT WEEK. OVERALL...A SOUTH- SOUTHWEST FLOW IS GENERALLY EXPECTED
EACH DAY...WITH THE FLOW VEERING OFFSHORE DURING THE NIGHTTIME/EARLY
MORNING HOURS. BRIEF SURGES UPWARDS OF NO MORE THAN 15-20 KT COULD
OCCUR AT TIMES...BUT WIND AND SEA CONDITIONS SHOULD REMAIN BELOW
SMALL CRAFT ADVISORY CRITERIA THROUGH THE PERIOD.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...JRL/RFM/JAQ
SHORT TERM...JAQ
LONG TERM...JAQ
AVIATION...BDC/RFM
MARINE...JRL/RFM/JAQ
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1010 AM CDT WED AUG 15 2012
...UPDATE TO SYNOPSIS...
.SYNOPSIS...
ISSUED AT 1010 AM CDT WED AUG 15 2012
THE 15.12Z 250 HPA MAP SHOWED THAT A 50-60 KT JET EXTENDED FROM KSLC
(SALT LAKE CITY, UT)...ACROSS OUR REGION (KDDC (DODGE CITY, KS)) AND
EVENTUALLY ACROSS MUCH OF THE EASTERN SEABOARD. THIS JET STRENGTHENED
TO 75 KT ACROSS NEW ENGLAND. ELSEWHERE, THERE WAS ANOTHER 50-75 KT JET
FROM ALBERTA SOUTHWARD TO MONTANA. AT 500 HPA, THE GEOPOTENTIAL HEIGHT
PATTERN INDICATED A FEW SHORTWAVE TROUGHS ACROSS NORTH AMERICA. THE
FIRST WAS A POSITIVELY TILTED TROF FROM MONTANA NORTHWARD INTO CENTRAL
CANADA. ANOTHER TROF WAS FROM JUST SOUTH OF SW KANSAS AND ACROSS THE
EASTERN 2/3RDS OF THE COUNTRY. ANOTHER SHORTWAVE TROF WAS LOCATED ACROSS
THE GREAT LAKES. 500 HPA SHORTWAVE RIDGING WAS SEEN ACROSS THE GREAT
BASIN. 500 HPA TEMPERATURES WERE FAIRLY SEASONAL ALTHOUGH THERE WAS
A SLIGHTLY COLDER POOL OF AIR ACROSS OKLAHOMA AROUND -10 DEG C ASSOCIATED
WITH THE AFOREMENTIONED TROF. AT 700 HPA, A WARM PLUME OF 15 DEG C TEMPS
WERE OBSERVED ACROSS THE GREAT BASIN AND ROCKIES. THERE WERE COOLER
LOW TO MID LEVEL TEMPS SOUTH OF THE REGION ASSOCIATED WITH A TROF. THE
COOLEST TEMPERATURES WERE ACROSS ALBERTA IN THE WAKE OF A SYNOPTIC WAVE
WITH VALUES AS LOW AS -3 DEG C. AT 850 HPA, A WARM PLUME WITH TEMPS
IN THE 25 TO 28 DEG C RANGE EXTENDED FROM KLBF (NORTH PLATTE, NE) TO
KUNR (RAPID CITY, SD). MUCH COOLER TEMPERATURES IN THE 5 TO 10 DEG C
RANGE WERE OBSERVED BEHIND A LOW LEVEL COLD FRONT ACROSS MONTANA AND
THE CANADIAN PRAIRIE PROVINCES. AT THE SURFACE, A WEAK LOW PRESSURE
CENTER WAS LOCATED ACROSS SOUTHERN MANITOBA. A COLD FRONT ASSOCIATED
WITH THIS PRESSURE PERTURBATION EXTENDED FROM THE LOW TO NORTHEAST WYOMING.
COOLER SURFACE TEMPERATURES IN THE UPPER 40S TO LOWER 60S DEG F WERE
ASSOCIATED IN THE WAKE OF THE FRONT. ANOTHER FRONTAL BOUNDARY WAS SOUTH
OF KANSAS (ACROSS TEXAS) WITH DEWPOINTS RUNNING IN THE 70S DEG F SOUTH
OF SAID BOUNDARY.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 430 AM CDT WED AUG 15 2012
FOG WILL BE A PROBLEM THIS MORNING. THE SURFACE LAYER OF MOISTURE IS
QUITE SHALLOW, AND JUST HOW DENSE AND WIDESPREAD THE FOG WILL BECOME
HAS NOT BEEN DETERMINED AT THIS TIME. THE HRRR CAPTURED THE INITIAL
DEVELOPMENT ACROSS CLARK-MEADE-FORD AND GRAY COUNTIES VERY WELL BUT
THE VISIBILITIES HAD BEEN SLOW TO BECOME DENSE. THE SHALLOW NATURE
OF THE MOISTURE MAY JUST PREVENT THAT TOO, HOWEVER, A WIDE AREA OF
DEW POINT DEPRESSIONS BELOW 3 DEGREES HAVE BEEN OBSERVED BETWEEN
HIGHWAYS 83 AND 283.
FOG SHOULD RAPIDLY DISSIPATE AFTER SUNRISE AS SOUTHWEST KANSAS IN
UNDER A CLEAR SKY. SURFACE WINDS WILL REMAIN SOUTHEASTERLY AND
LIGHT, BUT BEGIN TO GUST SLIGHTLY AS VERTICAL MIXING COMMENCES. WITH
MORE INSOLATION TODAY AND A SLIGHT MORE WARM ADVECTION, TEMPERATURES
THIS AFTERNOON SHOULD BE SEVERAL DEGREES WARMER ON AVERAGE THAN THE
PREVIOUS DAY. WIDESPREAD HIGHS IN THE UPPER 90S WITH POTENTIAL TO
TEST 100 DEGREES IS POSSIBLE.
A COLD FRONT WILL ENTER THE AREA TONIGHT, IN THE MID EVENING HOURS AS
DEPICTED BY THE NAM/WRF. THE MODEL APPEARS RELATIVELY DRY AT LEAST
INITIALLY WITH RESPECT TO CONVECTIVE DEVELOPMENT. SURFACE BASED
INSTABILITY IS WEAK TO MODERATE IN THE WARM SECTOR, AND GIVEN THE STEEP
MID LEVEL LAPSE RATES, THE MUCAPES ARE A BIT LARGER. THERE IS A
SUBTLE 700 MB WAVE RIGHT BEHIND THE BOUNDARY. THIS COULD BE THE
CATALYST TO SET OFF A FEW STORMS WITH THE SYSTEM, AS THE SURFACE
BASED POTENTIAL FOR THE FRONT DOESN`T APPEAR GREAT. WITH THIS IN
MIND, THUNDERSTORMS CHANCES WILL REMAIN IN THE ISOLATED CATEGORY AND
STRONG WIND GUSTS AND LIGHTNING APPEAR TO BE THE ONLY THREATS LATE
TONIGHT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 430 AM CDT WED AUG 15 2012
MODELS IN EXCELLENT AGREEMENT WITH A STRONG AND PROGRESSIVE
SHORTWAVE TROUGH MOVING INTO THE NORTHERN AND CENTRAL PLAINS ON
THURSDAY PUSHING A SIGNIFICANT COLD FRONT ACROSS THE REGION. THE
COLD FRONT IS FORECAST TO EXTEND FROM NORTHERN MISSOURI INTO EASTERN
KANSAS, NORTHERN OKLAHOMA, AND INTO THE WESTERN TEXAS PANHANDLE ON
THURSDAY MORNING THEN DROP SOUTH INTO THE SOUTHERN PLAINS DURING THE
AFTERNOON. A BROAD AREA OF COOLER HIGH PRESSURE IN ITS WAKE WILL
BRING A SIGNIFICANT COOL DOWN TO DAYTIME HIGHS INTO THE WEEKEND.
WILL CONTINUE WITH A 20 TO 30 POP ALONG THE COLD FRONT ON THURSDAY
MORNING MAINLY SOUTH OF A LINE FROM SAINT JOHN TO MEADE. SCATTERED
THUNDERSTORMS AND LIGHT SHOWERS MAY LINGER ACROSS THE SOUTHERN TIER
COUNTIES ALONG THE OKLAHOMA BORDER INTO THURSDAY NIGHT. NORTH WINDS
WILL GUST TO 30 MPH ON THURSDAY BEHIND THE COLD FRONT. A SECONDARY
VORT MAX ON THE BACK SIDE OF THE UPPER LOW COULD BRING IN ANOTHER
CHANCE FOR SHOWERS AND THUNDERSTORMS INTO FAR WESTERN KANSAS ON
FRIDAY THEN INTO MUCH OF SOUTHWEST AND SOUTH CENTRAL KANSAS ON
SATURDAY AND SATURDAY NIGHT. WILL MAINTAIN A 20 TO 30 POP FOR NOW.
THE LARGE UPPER TROUGH WILL THEN BEGIN TO MOVE EAST INTO THE EASTERN
CONUS FROM SUNDAY INTO EARLY NEXT WEEK WITH A WARMING TREND INTO THE
WESTERN HIGH PLAINS. THE MODELS SHOW ANOTHER CHANCE FOR
THUNDERSTORMS ON TUESDAY AS AN UPPER JET MOVES ACROSS THE PLAINS
ALONG WITH INCREASING LOW LEVEL MOISTURE AND WARM AIR ADVECTION.
OVERNIGHT LOWS WILL BE IN THE 50S FRIDAY AND SATURDAY MORNINGS THEN
SLOWLY WARMING INTO THE LOW TO MID 60S INTO EARLY NEXT WEEK. DAYTIME
HIGHS WILL WARM FROM AROUND 80 ON THURSDAY AND FRIDAY, THEN SLOWLY
WARM THROUGH THE MID TO UPPER 80S INTO MONDAY AND INTO THE LOWER 90S
BY TUESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 626 AM CDT WED AUG 15 2012
AREAS OF FOG WITH VSBYS AROUND 1-3SM AND CIGS ABOUT 200FT WILL LIFT
RAPIDLY THIS MORNING BY 14-15Z...THEN EXPECT VFR CONDITIONS. AN UPPER
DISTURBANCE WILL MOVE INTO THE PLAINS TONIGHT PUSHING A STRONG COLD
FRONT SOUTHWARD ACROSS THE TAF SITES. THE FRONT WILL SWITCH SOUTH
WINDS TO THE NORTH AND INCREASE TO 15-25KT BY AROUND 04-06Z AT KHYS,
AROUND 05-07Z AT KGCK, AND AROUND 06-08Z AT KDDC. AN ISOLATED SHOWER
OR THUNDERSTORM IS ALSO POSSIBLE WITH THE COLD FRONT.
&&
.FIRE WEATHER...
ISSUED AT 430 AM CDT WED AUG 15 2012
WINDS WILL BE LIGHT BUT GUSTING TO AROUND 20 KNOTS IN THE AFTERNOON
FROM THE SOUTHEAST. WARM TEMPERATURES AND DRY AIR WILL
DRIVE RELATIVE HUMIDITIES DOWN INTO THE 20 TO 30 PERCENT RANGE DURING
BETWEEN 3 AND 7 PM. A COLD FRONT WILL ENTER THE AREA THIS EVENING,
EFFECTIVELY TURNING WINDS TO THE NORTH THROUGH THE NIGHT, WITH
STRONGER NORTH WINDS EXPECTED BY THURSDAY .
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 97 66 81 53 / 0 40 10 10
GCK 98 64 80 53 / 10 20 10 10
EHA 97 64 81 55 / 10 30 20 20
LBL 98 66 83 54 / 0 30 20 20
HYS 97 65 79 53 / 10 20 10 10
P28 96 70 85 59 / 0 30 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...RUSSELL
LONG TERM...KRUSE
AVIATION...KRUSE
FIRE WEATHER...RUSSELL
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
637 AM CDT WED AUG 15 2012
...UPDATED FOR AVIATION...
.SYNOPSIS...
ISSUED AT 430 AM CDT WED AUG 15 2012
THE 00 UTC UPPER AIR OBJECTIVE ANALYSIS INDICATED A SPLIT FLOW
PATTERN AT 300 MB, FEATURING A SOUTHERN JET ACROSS THE SOUTHERN
PLAINS INTO THE MID MISSISSIPPI VALLEY AND A STRONGER JET SWINGING
THROUGH SOUTHWEST CANADA TOWARD THE NORTHERN PLAINS. THIS PATTERN
LEFT THE HIGH PLAINS REGION IN A BROAD WEAK NORTHWEST UPPER FLOW
PATTERN WITH WESTERN KANSAS ON THE THERMALLY DIRECT SUBSIDENCE REGION
OF THE EXITING JET. THE 00 UTC KDDC SOUNDING INDICATED SHALLOW
MOISTURE BELOW 800 MB, BUT A VERY DRY LAYER ALOFT THROUGH THE COLUMN
WITH LARGE DEW POINT DEPRESSIONS. A LARGE AREA OF FOG HAD EXPANDED
FROM THE WESTERN OKLAHOMA INTO THE AREAS WEST OF HIGHWAY 283 NEAR
STATE LINE. THIS AREA OF FOG WAS SLOWLY EXPANDING NORTHWARD THOUGH
THE OVERNIGHT.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 430 AM CDT WED AUG 15 2012
FOG WILL BE A PROBLEM THIS MORNING. THE SURFACE LAYER OF MOISTURE IS
QUITE SHALLOW, AND JUST HOW DENSE AND WIDESPREAD THE FOG WILL BECOME
HAS NOT BEEN DETERMINED AT THIS TIME. THE HRRR CAPTURED THE INITIAL
DEVELOPMENT ACROSS CLARK-MEADE-FORD AND GRAY COUNTIES VERY WELL BUT
THE VISIBILITIES HAD BEEN SLOW TO BECOME DENSE. THE SHALLOW NATURE
OF THE MOISTURE MAY JUST PREVENT THAT TOO, HOWEVER, A WIDE AREA OF
DEW POINT DEPRESSIONS BELOW 3 DEGREES HAVE BEEN OBSERVED BETWEEN
HIGHWAYS 83 AND 283.
FOG SHOULD RAPIDLY DISSIPATE AFTER SUNRISE AS SOUTHWEST KANSAS IN
UNDER A CLEAR SKY. SURFACE WINDS WILL REMAIN SOUTHEASTERLY AND
LIGHT, BUT BEGIN TO GUST SLIGHTLY AS VERTICAL MIXING COMMENCES. WITH
MORE INSOLATION TODAY AND A SLIGHT MORE WARM ADVECTION, TEMPERATURES
THIS AFTERNOON SHOULD BE SEVERAL DEGREES WARMER ON AVERAGE THAN THE
PREVIOUS DAY. WIDESPREAD HIGHS IN THE UPPER 90S WITH POTENTIAL TO
TEST 100 DEGREES IS POSSIBLE.
A COLD FRONT WILL ENTER THE AREA TONIGHT, IN THE MID EVENING HOURS AS
DEPICTED BY THE NAM/WRF. THE MODEL APPEARS RELATIVELY DRY AT LEAST
INITIALLY WITH RESPECT TO CONVECTIVE DEVELOPMENT. SURFACE BASED
INSTABILITY IS WEAK TO MODERATE IN THE WARM SECTOR, AND GIVEN THE STEEP
MID LEVEL LAPSE RATES, THE MUCAPES ARE A BIT LARGER. THERE IS A
SUBTLE 700 MB WAVE RIGHT BEHIND THE BOUNDARY. THIS COULD BE THE
CATALYST TO SET OFF A FEW STORMS WITH THE SYSTEM, AS THE SURFACE
BASED POTENTIAL FOR THE FRONT DOESN`T APPEAR GREAT. WITH THIS IN
MIND, THUNDERSTORMS CHANCES WILL REMAIN IN THE ISOLATED CATEGORY AND
STRONG WIND GUSTS AND LIGHTNING APPEAR TO BE THE ONLY THREATS LATE
TONIGHT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 430 AM CDT WED AUG 15 2012
MODELS IN EXCELLENT AGREEMENT WITH A STRONG AND PROGRESSIVE
SHORTWAVE TROUGH MOVING INTO THE NORTHERN AND CENTRAL PLAINS ON
THURSDAY PUSHING A SIGNIFICANT COLD FRONT ACROSS THE REGION. THE
COLD FRONT IS FORECAST TO EXTEND FROM NORTHERN MISSOURI INTO EASTERN
KANSAS, NORTHERN OKLAHOMA, AND INTO THE WESTERN TEXAS PANHANDLE ON
THURSDAY MORNING THEN DROP SOUTH INTO THE SOUTHERN PLAINS DURING THE
AFTERNOON. A BROAD AREA OF COOLER HIGH PRESSURE IN ITS WAKE WILL
BRING A SIGNIFICANT COOL DOWN TO DAYTIME HIGHS INTO THE WEEKEND.
WILL CONTINUE WITH A 20 TO 30 POP ALONG THE COLD FRONT ON THURSDAY
MORNING MAINLY SOUTH OF A LINE FROM SAINT JOHN TO MEADE. SCATTERED
THUNDERSTORMS AND LIGHT SHOWERS MAY LINGER ACROSS THE SOUTHERN TIER
COUNTIES ALONG THE OKLAHOMA BORDER INTO THURSDAY NIGHT. NORTH WINDS
WILL GUST TO 30 MPH ON THURSDAY BEHIND THE COLD FRONT. A SECONDARY
VORT MAX ON THE BACK SIDE OF THE UPPER LOW COULD BRING IN ANOTHER
CHANCE FOR SHOWERS AND THUNDERSTORMS INTO FAR WESTERN KANSAS ON
FRIDAY THEN INTO MUCH OF SOUTHWEST AND SOUTH CENTRAL KANSAS ON
SATURDAY AND SATURDAY NIGHT. WILL MAINTAIN A 20 TO 30 POP FOR NOW.
THE LARGE UPPER TROUGH WILL THEN BEGIN TO MOVE EAST INTO THE EASTERN
CONUS FROM SUNDAY INTO EARLY NEXT WEEK WITH A WARMING TREND INTO THE
WESTERN HIGH PLAINS. THE MODELS SHOW ANOTHER CHANCE FOR
THUNDERSTORMS ON TUESDAY AS AN UPPER JET MOVES ACROSS THE PLAINS
ALONG WITH INCREASING LOW LEVEL MOISTURE AND WARM AIR ADVECTION.
OVERNIGHT LOWS WILL BE IN THE 50S FRIDAY AND SATURDAY MORNINGS THEN
SLOWLY WARMING INTO THE LOW TO MID 60S INTO EARLY NEXT WEEK. DAYTIME
HIGHS WILL WARM FROM AROUND 80 ON THURSDAY AND FRIDAY, THEN SLOWLY
WARM THROUGH THE MID TO UPPER 80S INTO MONDAY AND INTO THE LOWER 90S
BY TUESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 626 AM CDT WED AUG 15 2012
AREAS OF FOG WITH VSBYS AROUND 1-3SM AND CIGS ABOUT 200FT WILL LIFT
RAPIDLY THIS MORNING BY 14-15Z...THEN EXPECT VFR CONDITIONS. AN UPPER
DISTURBANCE WILL MOVE INTO THE PLAINS TONIGHT PUSHING A STRONG COLD
FRONT SOUTHWARD ACROSS THE TAF SITES. THE FRONT WILL SWITCH SOUTH
WINDS TO THE NORTH AND INCREASE TO 15-25KT BY AROUND 04-06Z AT KHYS,
AROUND 05-07Z AT KGCK, AND AROUND 06-08Z AT KDDC. AN ISOLATED SHOWER
OR THUNDERSTORM IS ALSO POSSIBLE WITH THE COLD FRONT.
&&
.FIRE WEATHER...
ISSUED AT 430 AM CDT WED AUG 15 2012
WINDS WILL BE LIGHT BUT GUSTING TO AROUND 20 KNOTS IN THE AFTERNOON
FROM THE SOUTHEAST. WARM TEMPERATURES AND DRY AIR WILL
DRIVE RELATIVE HUMIDITIES DOWN INTO THE 20 TO 30 PERCENT RANGE DURING
BETWEEN 3 AND 7 PM. A COLD FRONT WILL ENTER THE AREA THIS EVENING,
EFFECTIVELY TURNING WINDS TO THE NORTH THROUGH THE NIGHT, WITH
STRONGER NORTH WINDS EXPECTED BY THURSDAY .
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 97 66 81 53 / 0 40 10 10
GCK 98 64 80 53 / 10 20 10 10
EHA 97 64 81 55 / 10 30 20 20
LBL 98 66 83 54 / 0 30 20 20
HYS 97 65 79 53 / 10 20 10 10
P28 96 70 85 59 / 0 30 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RUSSELL
SHORT TERM...RUSSELL
LONG TERM...KRUSE
AVIATION...KRUSE
FIRE WEATHER...RUSSELL
AREA FORECAST DISCUSSION
NWS CARIBOU ME
936 AM EDT WED AUG 15 2012
.SYNOPSIS...
A TROUGH OF LOW PRESSURE WILL APPROACH FROM THE WEST TODAY AND
TONIGHT. LOW PRESSURE WILL CROSS THE GULF OF MAINE THURSDAY. A
COLD FRONT WILL APPROACH LATER FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
930 AM UPDATE...MADE ADJUSTMENTS TO LOWER POPS THIS MORNING AS
SHOWERS WITH NEXT SYSTEM ARE STILL WELL TO OUR WEST. HOWEVER...I
DID INCREASE POPS TO CATEGORICAL ACROSS THE NORTHWEST THIS
AFTERNOON AS LATEST MODEL AND THE HRRR SUPPORT THIS.
PREVIOUS DISCUSSION
A TROUGH OF LOW PRESSURE APPROACHING FROM THE WEST WILL
BRING INCREASING CHANCES FOR SHOWERS ACROSS THE AREA TODAY. A
SHORTWAVE EMBEDDED IN THE TROUGH IS MOVING INTO WESTERN NEW
ENGLAND EARLY THIS MORNING AND WILL LIFT INTO WESTERN MAINE DURING
THE MIDDAY TODAY AND THEN MOVE THROUGH NORTHERN AND EASTERN MAINE
LATER THIS AFTERNOON. THIS SHORTWAVE WILL PROVIDE FOCUS FOR
SHOWERS AND SOME EMBEDDED THUNDERSTORMS. CAPES ON BOTH THE GFS AND
NAM ARE BETWEEN 600 AND 700 J/KG THIS AFTERNOON AND PRECIPITABLE
QPF IS AROUND 1.5 INCHES. WITH TALL...THIN CAPES AND SATURATED AIR
ANY THUNDERSTORMS TODAY COULD PRODUCE HEAVY DOWNPOURS. THE MAIN
TROUGH AXES WILL MOVE INTO THE REGION LATER TONIGHT BRINGING
ANOTHER AREA OF CONCENTRATED SHOWERS AND PERHAPS AN AREA OF
STEADIER RAIN LATER TONIGHT ESPECIALLY IN WESTERN AREAS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
LOW PRESSURE CROSSING THE GULF OF MAINE WILL BRING RAIN TO THE
REGION THURSDAY. THE LOW WILL MOVE EAST THURSDAY NIGHT ALLOWING
THE RAIN TO TAPER TO SHOWERS. A COLD FRONT WILL THEN APPROACH
FRIDAY WITH A CHANCE OF SHOWERS/THUNDERSTORMS IN ADVANCE OF THE
FRONT. THE FRONT BEGINS TO SLOWLY CROSS THE REGION FRIDAY NIGHT
WITH A CHANCE OF SHOWERS/THUNDERSTORMS. TEMPERATURES WILL BE AT
BELOW NORMAL LEVELS THURSDAY...WITH NEAR NORMAL LEVEL TEMPERATURES
FRIDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
UNCERTAINTY STILL EXISTS REGARDING HOW QUICKLY THE FRONT CROSSES
THE REGION SATURDAY THROUGH SUNDAY. A MORE RAPID MOVEMENT WOULD
KEEP A CHANCE OF SHOWERS ACROSS THE REGION SATURDAY WITH THE
FRONT...WITH THE FRONT THEN MOVING EAST SUNDAY ALLOWING FOR
IMPROVING CONDITIONS. A SLOWER FRONTAL MOVEMENT COULD KEEP THE
FRONT ACROSS THE REGION THROUGH SUNDAY WITH LOW PRESSURE POSSIBLY
LIFTING NORTH ALONG THE FRONT. THE SLOWER SCENARIO WOULD KEEP
UNSETTLED CONDITIONS ACROSS THE REGION THROUGH THE WEEKEND. HAVE
BASED THE FORECAST ON A SLOWER SOLUTION...WHICH MOVES THE SYSTEM
SLOWLY EAST MONDAY. COULD STILL HAVE A CHANCE OF SHOWERS ACROSS
THE REGION MONDAY. A COLD FRONT COULD THEN APPROACH TUESDAY WITH A
CHANCE OF SHOWERS/THUNDERSTORMS. TEMPERATURES SHOULD REMAIN AT
SLIGHTLY BELOW NORMAL LEVELS SATURDAY THROUGH TUESDAY.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
NEAR TERM: GENERALLY VFR CONDITIONS ARE EXPECTED TODAY INTO EARLY
TONIGHT THOUGH CONDITIONS MAY BRIEFLY LOWER TO MVFR OR IFR IN
HEAVIER SHOWERS. CONDITIONS MAY LOCALLY DROP TO IFR LATE TONIGHT
IN PATCHY FOG.
SHORT TERM: CONDITIONS THURSDAY ARE EXPECTED TO GENERALLY RANGE
FROM MVFR TO IFR LEVELS...WITH OCCASIONAL LIFR CONDITIONS. OCCASIONAL
MVFR CONDITIONS WILL REMAIN POSSIBLE THURSDAY NIGHT. GENERALLY VFR
CONDITIONS ARE EXPECTED FRIDAY THROUGH SATURDAY...THOUGH
OCCASIONAL MVFR CONDITIONS COULD OCCUR WITH ANY SHOWERS OR
THUNDERSTORMS. CONDITIONS SUNDAY WILL BE DEPENDENT ON HOW QUICKLY
THE FRONT MOVES EAST OF THE REGION. HOWEVER...EXPECT OCCASIONAL
MVFR CONDITIONS COULD REMAIN POSSIBLE WITH SHOWERS.
&&
.MARINE...
NEAR TERM: WINDS AND SEAS WILL REMAIN BELOW SCA TODAY AND
TONIGHT. SOME FOG MAY MOVE OVER THE WATERS LATER TONIGHT.
SHORT TERM: WINDS/SEAS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT
ADVISORY LEVELS THURSDAY THROUGH SUNDAY. VISIBILITIES WILL BE
REDUCED IN RAIN AND FOG THURSDAY INTO THURSDAY NIGHT. OCCASIONAL
SHOWERS ARE THEN POSSIBLE LATER FRIDAY THROUGH THE WEEKEND.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...BLOOMER/DUDA
SHORT TERM...NORCROSS
LONG TERM...NORCROSS
AVIATION...BLOOMER/DUDA
MARINE...BLOOMER/DUDA/NORCROSS
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1028 AM EDT WED AUG 15 2012
.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION TODAY. HIGH PRESSURE BUILDS
INTO THE REGION THROUGH THURSDAY. A SECOND COLD FRONT WILL IMPACT
THE MID-ATLANTIC REGION ON FRIDAY AND WILL STALL OVER THE WEEKEND
IN SOUTHERN VIRGINIA.
&&
.NEAR TERM /THROUGH TONIGHT/...
14Z SFC ANALY PLACES SFC TROF AXIS EITHER DOWN THE CHSPK BAY OR
DELMARVA. DIFFUSE CDFNT IN NWRN CWFA. HWVR...LOTSA MID DECK CLDS
HV INVADED CWFA...WHICH PRECLUDES SGFNT HTG. CNVCTV TEMPS OFF OF
12Z IAD RAOB 88F. AFTR MODIFICATION /TEMP 85...DEWPT 65/ CNVCTV
TEMP DROPS OFF TO 85F. UNLESS THERE WL BE MORE BINOVC THAN IT
APPEARS ATTM...THE MODIFIED CONDS MAY BE WORSE CASE. HV LWRD MAXT
BY SVRL DEGF...AND ADJUSTED POPS ACCRDGLY. A S/WV ENTERING SRN
WVA/WRN VA ATTM WL BE THE PRIME TRIGGER. HRRR TIMING OF THIS
FEATURE BRINGS TSRA TO SRN CNTYS 17-19 UTC...AND PASSING S OF EZF
BY 00Z. THRU THIS TIME THERE MAY BE OTR TSRA DVLPG INVOF LEE TROF
NEAR THE BAY.
UPPER SHORTWAVE TROUGH AND COLD FRONT EXIT THE REGION BY THIS
EVE. CONVECTIVE CHANCES WILL QUICKLY END BY SUNSET AS NW FLOW
BEHIND THE FRONT ADVECTS DRIER AIR INTO THE REGION. HIPRES BUILDS
IN FROM THE WEST TNGT. CLEARING SKIES AND LGT WINDS WILL PROVIDE
DECENT RADIATIONAL COOLING CONDITIONS OVNGT. MIN TEMPS WILL RANGE
FROM THE UPPER 50S IN THE WRN HIGHLANDS TO NEAR 70F IN THE CITIES
AND ALONG THE COAST.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
UPR RDG AND ATTENDANT SFC HIPRES WILL BE DOMINANT FEATURES THU-THU
NGT IN THE MID-ATLC RGN. SLGT DRYING OF LOW LVLS AND SUBSIDENCE
WILL YIELD MOSTLY CLR CONDS FOR MUCH OF THU...WITH ONLY A MODEST
TERRAIN-FOCUSED CU FIELD.
A STRONG CLOSED H5 LOW OVER S-CNTRL CANADA WILL ACQUIRE NEGATIVE
TILT AS IT MOVES SLOWLY EWD THU NGT. SWLY LOW-LVL FETCH AHD OF ITS
ASSOCIATED CDFNT WILL AID IN MSTR TRANSPORT INTO THE MID-ATLC RGN.
THICK CI XPCD TO APRCH THE FCST AREA ON THU NGT FROM THE NW...WITH
PCPN XPCD TO APRCH THE WRN ZONES BY FRI MRNG.
THERE IS A PSBLTY OF SVR TSTMS FRI AFTN ALONG AND AHD OF THE
CDFNT...BUT THERE ARE SVRL PSBL FAILURE MECHANISMS. INCRG CLD CVR
AND LMTD MSTR RETURN MAY YIELD ONLY MODEST DESTABILIZATION IN A
LRG PORTION OF THE RGN. A LONGER PD OF HEATING IS FCSTD E OF BLUE
RDG...WHICH MAY CONTRIBUTE TO GREATER INSTBY AND CONSEQUENT TSTM
INTENSITY.
CDFNT CROSSES THE RGN FRI EVE. NLY WINDS IN WAKE OF CDFNT WILL
SCOUR OUT LOW-LVL MSTR...BUT CLD CVR MAY LINGER INTO SAT MRNG.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
HIGHLY-AMPLIFIED UPR AIR PATTERN XPCD THIS WKEND...WITH DP TROF
OVER ERN HALF OF CONUS AND STRONG RDG OVER WRN CONUS. FRI CDFNT
WILL STALL IN SRN VA ON SAT BFR MOVG SLGTLY NWD IN RESPONSE TO
SHRTWV TROF THAT WILL APRCH ON SUN.
THE STALLED BNDRY WILL BE THE FOCUS FOR SHWRS AND TSTMS ON SAT.
WSWLY STEERING FLOW MAY DIRECT A FEW OF THESE TSTMS INTO SRN
PORTIONS OF THE FCST AREA...SO POPS WERE FOCUSED IN SRN ZONES.
CHCS FOR PCPN DECR CONSIDERABLY WITH NWD EXTENT.
SHRTWV TROF WILL APRCH ON SUN...INDUCING ELY LOW-LVL FLOW N OF THE
STALLED FRONTAL BNDRY. THIS MAY ENABLE THE BNDRY TO MOVE SLGTLY
NWD ON SUN. THE PRESENCE OF THE BNDRY AND UPSLP ELY LOW-LVL FLOW
MAY AID IN GENERATION OF TERRAIN-FOCUSED SHWRS AND TSTMS SUN-SUN
NGT.
COMPARABLY COOLER AMS WILL ENGULF THE FCST AREA ON SAT AND WILL
LINGER THRU EARLY NEXT WK. DAILY MAXIMA WILL BE IN THE UPR 70S-LWR
80S.
ONSHORE FLOW XPCD TUE-WED WILL PRESERVE A MOIST BNDRY LYR IN MUCH
OF FCST AREA. VERY WEAK MID-LVL FLOW BUT THE PRESENCE OF A WEAK
UPR WAVE MAY SUPPORT LOW CHCS FOR SHWRS LATE IN THE FCST PD AS
TEMPS RECOVER SLOWLY.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDS ACRS TERMINALS ATTM. HOWEVER...SCT SHRA/TSRA EXPECTED TO
DEVELOP THIS AFTN AHEAD OF AN UPPER DISTURBANCE. LOCAL/BRIEF
RESTRICTIONS POSSIBLE IN STORMS...MOST LKLY INVOF CHO. ACTIVITY
SHOULD BE EAST OF BWI/MTN/DCA BY THE EVE AS THE COLD FRONT MOVES
OFF THE COAST. DRIER AIR BEHIND THE FRONT SHOULD PREVENT ANY
DEVELOPMENT OF FOG.
VFR CONDS XPCD THU-THU NGT. CDFNT WILL APRCH FROM THE NW ON FRI
AND WILL PROVIDE A FOCUS FOR SHWRS AND TSTMS FRI AFTN AT ALL
TERMINALS.
CDFNT WILL STALL IN SRN VA ON SAT. BEST CHC FOR CNVCTN DURG THE
WKEND WILL BE AT KCHO...WHOSE PROXIMITY TO THE BNDRY MAY ENABLE
TSTMS TO IMPACT THE TERMINAL.
&&
.MARINE...
NLY FLOW ACRS WATERS ATTM. WINDS WILL REMAIN BELOW SCA LVLS TDA.
MAIN CONCERN OVER THE WATERS TAFTN IS FOR POTENTIALLY STRONG
STORMS THIS AFTN. SMWS MAY BE NEEDED FOR GUSTY WINDS AND LARGE
HAIL.
NO SGFNT HAZARDS ANTICIPATED UNTIL FRI...WHEN CDFNT WILL CROSS THE
RGN. TSTMS ALONG THIS BNDRY WILL IMPACT THE WATERS FRI AFTN-EVE
AND MAY WARRANT SPCL MARINE WRNGS.
NLY WINDS XPCD ON SAT BFR AN UPR WAVE APRCHS FROM THE W. THE APRCH
OF THIS WAVE WILL YIELD ONSHORE ELY FLOW ACRS THE WATERS.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...HTS/KLEIN
SHORT TERM...KRAMAR
LONG TERM...KRAMAR
AVIATION...HTS/KLEIN/KRAMAR
MARINE...HTS/KLEIN/KRAMAR
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1106 AM EDT WED AUG 15 2012
.SYNOPSIS...
SHOWERS ALONG WITH ISOLATED THUNDERSTORMS WILL CONTINUE TODAY AHEAD
OF AN UPPER LEVEL TROUGH. HIGH PRESSURE WILL BUILD OVER CENTRAL NEW
YORK AND NORTHEAST PENNSYLVANIA FOR THURSDAY...LEADING TO A DRY AND
SUNNY DAY WITH HIGH TEMPERATURES INTO THE 80S. A COLD FRONT WILL
RACE THROUGH ON FRIDAY WITH ANOTHER CHANCE FOR SHOWERS AND
THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED AT 1030 AM... LATEST ANALYSIS SHOWS WEAK LOW PRESSURE OVER
NJ WITH LIGHT NNW FLOW ACROSS NE PA AND CENTRAL NY. LOW CLOUDS
FROM MOISTURE LEFT OVER FROM YESTERDAY`S CONVECTION STILL COVERS
MUCH OF THE AREA... WITH THE EXCEPTION OF THE FAR SOUTHEAST ALONG
THE DELAWARE RIVER IN PA WHERE SKIES ARE CLEAR... AND ALSO OVER
THE NORTHERN FINGER LAKES WERE BREAKS ARE BEGINNING TO DEVELOP.
MODELS STILL DEVELOP SOME MODEST INSTABILITY THIS AFTERNOON WITH
LATEST RUC CAPES STILL APPROACHING 1000 J/KG AT MANY LOCATIONS.
WITH LIGHT WINDS EXPECT SHOWERS THAT DEVELOP WILL BE OF THE PULSE
VARIETY WITH A FEW OF THE BIGGER STORMS POSSIBLY APPROACHING
SEVERE LIMITS IN THE SOUTHEAST WHERE THE MOST HEATING WILL OCCUR.
PREVIOUS DISCUSSION BELOW.
UPDATED AT 415 AM...HV LOWERED POPS DRAMATICALLY ACRS THE TWIN
TIERS AS SHOWERS AND TSTMS ARE FINALLY WANING. WILL KEEP AN EYE ON
PATCHY FOG DVLPMNT LATER THIS MRNG.
PREV DISCUSSION...
SHOWERS AND TSTMS CONTINUE TO AFFECT THE TWIN TIERS. UL TROF CONT TO
SWING ACRS NERN HALF OF THE U.S. WITH MOISTURE BEING PUMPED NWRD INTO
THE AREA. THIS COUPLED WITH WK SFC BNDRYS STILL LINGERING IN THE
VICINITY WL CONT SHOWERS AND TSTMS THRU APPROX 09Z AND HV UPPED POPS
TO LKLY-CATEGORICAL FIRST SVRL HRS OF THE NR TERM. LARGE AREA OF
CONVECTION PARKED ACRS SERN PA DOES NOT APPEAR TO BE IMPACTING
STORMS OVR OUR CWA AS THERE APPEARS TO BE CONSIDERABLE MOISTURE
AVAILABLE.
MAIN QUESTION IS WHEN CONVECTION WILL END THIS MRNG AND IF CLDS WILL
BE ABLE TO CLEAR. THIS MAY SET THE STAGE FOR LOCALLY DENSE VALLEY
FOG THIS MRNG AND WL KEEP A CLOSE EYE ON THIS.
AS FOR THIS AFTN GOES...H5 TROF PROGGED TO SWING THRU TDA AND
PUSHING EAST OF FA LATER THIS EVNG. WITH THIS FEATURE EXPECTED TO
AFFECT AREA WL KEEP SCTD CONVECTION MENTION IN TDA. TEMPS WL TOP OUT
IN THE U70S TO NR 80 UNLESS SOME SUN CAN BREAK THRU IN MOIST
AIRMASS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
CDFNT MVS THRU LATE TONIGHT WITH TEMPS BY THUR MRNG DROPPING INTO
THE 50S..MORE SEASONAL FOR THIS TIME OF YR. EXPECT LOCALLY DENSE FOG
TO DVLP LATE TONIGHT AS SKIES CLR AND WINDS DECOUPLE UNDER HIPRES.
THURSDAY WL FEATURE SUNNY SKIES UNDER S/WV RIDGING AND AFTN MAXES
WELL INTO THE 80S. THIS WILL HELP PRIME THE PUMP FOR IMPENDING CDFNT
MVG THRU ON FRIDAY.
SKIES WL BEGIN TO CLD OVR ON FRI MRNG FM WEST TO EAST IN CONJUNCTION
WITH SFC BNDRY APPCHG ALONG WITH UL TROF. TIMING OF CDFNT APPEARS TO
HV SLOWED DOWN WHEN COMPARING 00Z NAM TO 18Z RUN THO IT QUICKLY
CATCHES UP BY FRI AFTN. TIMING LOOKS TO BE FAIRLY IDEAL
(INSTABILITY-WISE) FOR SVR WX POTENTIAL WITH MLCAPES ARND 1000 J/KG
PER BUFKIT SNDGS ACRS CNTRL NY AND DOWN INTO NEPA. LI/S GNRLY RANGE
FM -3 TO -5 WITH AREA IN RRQ OF UL SPEED MAX.
ONLY FLY IN THE OINTMENT WILL BE TIMING OF WIND SHEAR POTENTIAL. H8
LLJ LOOKS TO RANGE FM 25-30KTS FRI AFTN ALONG WITH 0-6KM BULK SHEAR
VALUES INCRSG TO 35 KTS DRG THE EVNG HRS...MAINLY AFTER SUNSET.
TIMING OF THESE PARAMETERS LOOK TO BE OFF FM BEST INSTABILITY ALONG
WITH MAX HTG. WL CONTINUE IDEA OF SVR WX POTENTIAL IN THE HWO BUT
SVRL ITEMS APPEAR TO BE DISJOINTED REGARDING SLAM-DUNK SVR WX.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
2 PM UPDATE...
WE WILL START OFF THE EXTENDED PERIOD UNSETTLED WITH A TREND
TOWARD DRIER BUT COOLER WEATHER OVER THE WEEKEND. BEST SHOT AT
PRECIPITATION IN THIS PERIOD WILL COME FRIDAY NIGHT WITH A FRONT
MOVING THROUGH. THE 12Z GFS AND CANADIAN ARE FASTER WITH THE
FRONT...DRYING US OUT BY 12Z SATURDAY. THE 0Z EURO IS MUCH
SLOWER AND ACTUALLY SLOWER THAN THE PREVIOUS RUNS OF THIS MODEL.
FOR NOW WILL LEAVE IN CHANCE POPS OVER THE FAR SOUTHEAST THROUGH
EARLY SATURDAY MORNING. WE MAY BE ABLE TO YANK THESE THOUGH IF THE
12Z EURO COMES IN FASTER...MORE IN LINE WITH THE OTHER LONG RANGE GUIDANCE.
WE SHOULD SEE A PERIOD OF DRY WEATHER FOR THE REST OF SATURDAY
INTO MOST OF SUNDAY BEFORE WE BEGIN TO SEE THE INFLUENCE OF A
DIGGING H5 TROF OVER THE OHIO VALLEY. BOTH THE GFS AND CANADIAN
ARE A BIT MORE AGGRESSIVE IN SENDING MOISTURE ARE WAY BY LATE
SUNDAY...WHICH MAY BE ENOUGH WITH FALLING H5 HEIGHTS FOR SOME
ISOLATED SHOWERS ESPECIALLY WEST OF I-81. STILL FEEL THE BETTER THREAT
FOR CONVECTIVE SHOWERS WITH THE UPPER LEVEL TROF WILL INCREASE
THROUGH MONDAY...BEFORE REACHING A PEAK TUESDAY WITH THE TROF AXIS
MOVING THROUGH. THE BIGGER STORY THIS WEEKEND WILL LIKELY BE THE
TEMPERATURES AS 850 TEMPS REMAIN IN THE SINGLE DIGITS...WHICH WILL
KEEP HIGHS IN THE LOWER TO MIDDLE 70S. PERHAPS A SIGN FALL IS NOT
TOO FAR AROUND THE CORNER.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
IFR CONDITIONS THIS MORNING WILL BEGIN TO IMPROVE OVER THE NEXT
FEW HOURS AS WIND BEGIN TO MIX THE ATMOSPHERE. CLOUDS WILL
GRADUALLY BREAK FROM NORTHWEST TO SOUTHEAST LATER TODAY. THERE IS
STILL SOME INSTABILITY AROUND TODAY, WHICH COULD LEAD TO ANOTHER
ROUND OF SHOWERS AND THUNDERSTORMS. THE CONDITIONS LOOK MORE
FAVORABLE TO THE SOUTH, OVER NEPA. HOWEVER, THEY COULD POP UP
ANYWHERE OVER THE FORECAST AREA THIS AFTERNOON. HAVE ONLY
MENTIONED CONVECTION IN THE KAVP TAF.
AS SKIES BEGIN TO CLEAR TONIGHT, RADIATIONAL COOLING WILL LIKELY
LEAD TO SOME VALLEY FOG OR LOW STRATUS. HAVE BEGAN TO MENTION THIS
IN THE TAFS FOR THE AREA THAT LOOK TO BE AFFECTED.
WINDS WILL BECOME NW BETWEEN 5 AND 10 KTS BY MID DAY. THEN WILL
GO BACK TO LIGHT AND VARIABLE TONIGHT.
OUTLOOK...
WED NGT-FRI AM...MAINLY VFR EXCEPT FOR VALLEY FOG EARLY EACH
MRNG.
FRI PM...MVFR IN SHOWERS/TSRA POSSIBLE.
SAT/SUN...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...PVN
NEAR TERM...MSE/PVN
SHORT TERM...PVN
LONG TERM...HEDEN
AVIATION...SLI
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1108 AM EDT WED AUG 15 2012
.SYNOPSIS...
A SLOW MOVING COLD FRONT WILL PUSH ACROSS EASTERN PENNSYLVANIA
THIS AFTERNOON. A RIDGE OF HIGH PRESSURE WILL BUILD ACROSS THE STATE
TONIGHT AND THURSDAY. A STRONGER COLD FRONT WILL PUSH THROUGH THE
REGION ON FRIDAY. AN ANOMALOUS UPPER LEVEL TROUGH WILL LIKELY
REMAIN PARKED OVER THE NORTHEAST CONUS THIS WEEKEND INTO EARLY
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MORNING FOG HAS LIFTED FOR THE MOST PART...BUT LOW CLOUDS REMAIN
PREVALENT ACROSS CENTRAL PA. A SCT-BKN SHIELD OF MID-HIGH CLOUD
STREAMING NORTH OF THE MASON DIXON LINE WILL LIMIT INSOLATION THIS
AFTERNOON OVER THE LOWER SUSQ. SREF PROBS OF EXCEEDING 500 AND
1000 J/KG ARE HIGHEST TO THE EAST OF MY AREA...AND THIS CLOUD
COVER WILL HINDER CONVECTIVE CHANCES THIS AFTERNOON.
STILL...APPROACHING SHORTWAVES SHOULD PHASE AS THEY CROSS CENTRAL PA
DURING TIME OF MAX HEATING THIS AFTN...PRODUCING SCT PM TSRA.
ALTHOUGH COVERAGE WILL BE GREATEST NEAR SFC COLD FRONT ACROSS
EXTREME EASTERN PA...EXPECT A FEW SHRA/TSRA TO DEVELOP AS FAR WEST
AS SPINE OF THE APPALACHIANS...WHERE MDLS INDICATES RESIDUAL LOW
LVL MOISTURE/MARGINAL INSTABILITY. LATEST HRRR DATA CONTINUES TO
SUPPORT THIS SCENARIO.
AS A RESULT OF THE AFOREMENTIONED CLOUDS...HIGH TEMPS SHOULD BE A
BIT COOLER THAN 8H TEMPS MIGHT SUGGEST. THE COOLER TEMPS AND
RESULTING LESS INSTABILITY SUGGEST A DIMINISHED THREAT OF SVR WX
ACROSS SE PA. ALSO...06Z MDL DATA INDICATING RELATIVELY WEAK
SHEAR...IMPLYING ORGANIZED CONVECTION UNLIKELY. UNDER MCLDY
SKIES...MAX TEMPS SHOULD RANGE FROM THE M70S OVR THE ALLEGHENY
HIGHLANDS...TO THE L80S IN THE SUSQ VALLEY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
ANY EVENING TSRA ACROSS THE EASTERN HALF OF THE STATE WILL
DIMINISH BY LATE THIS EVENING...AS THE SHORTWAVE PASSES EAST OF
PA. ARRIVAL OF HIGH PRES RIDGE AND ASSOC DRY AIR MASS WILL BRING
CLEARING SKIES AND LIGHT WINDS TONIGHT. BEST COMBINATION OF DRY
AIR AND LIGHT WINDS FOR RAD COOLING WILL BE ACROSS THE NW
MTNS...WHERE TEMPS WILL LIKELY DIP INTO THE U40S. THE COOL
TEMPS...COMBINED WITH RELATIVELY WARM RIVER/STREAM WATERS...SHOULD
RESULT IN PATCHY VALLEY FOG LATE TONIGHT...ESP OVR NORTHWEST PA.
HIGH PRES RIDGE HIGH PRES AND ASSOC DRY AIR MASS SHOULD PROVIDE
THE REGION WITH ABUNDANT SUNSHINE AND LGT WINDS ON THURSDAY. ENS
MEAN 8H TEMPS SUPPORT HIGHS FROM NR 80F OVER THE ALLEGHENY
HIGHLANDS TO THE M/U80S IN THE SUSQ VALLEY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
LITTLE SPREAD IN THE MED RANGE AMONG MDL DATA...ALL OF WHICH
INDICATE A DEEPENING UPPER LVL TROF OVR THE GRT LKS/MIDWEST LATE
THIS WEEK THRU THE WEEKEND. THE SFC COLD FRONT ASSOCIATED WITH
THIS FEATURE SHOULD PUSH THRU PA ON FRIDAY. EARLY INDICATIONS ARE
FOR ONLY MARGINAL INSTABILITY...AS FRONT ARRIVES FRI AFTN.
HOWEVER...STRONG FLOW ALOFT AND RESULTING DEEP LYR SHEAR ARE
FAVORABLE FOR ORGANIZED CONVECTION AND THE POSSIBILITY OF DAMAGING
WIND GUSTS. DEEPENING TROF OVR THE GRT LKS WILL SLOW THE EASTWARD
PROGRESSION OF CDFRONT ON SATURDAY...INDICATING TSRA MAY REMAIN
POSSIBLE ON SAT OVER THE EASTERN HALF OF THE STATE.
AN ANOMALOUS UPPER LVL TROUGH OVER THE NORTHEAST CONUS SIGNALS
SLIGHTLY BLW NORMAL TEMPS SUN-TUE WITH ECMWF ENS MEAN 8H TEMPS
POINTING TOWARD HIGHS MOSTLY IN THE 70S. BULK OF MED RANGE
GUIDANCE ALSO POINTS TOWARD MAINLY DRY WX SUN-TUE WITH SFC HIGH
PRES RIDGE PARKED OVR THE STATE. STILL...WITH UPPER TROF AND COLD
TEMPS ALOFT IN THE VICINITY...WILL MAINTAIN A LOW CHC OF PM
CONVECTION.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
FOG PRODUCING WIDESPREAD MVFR VISIBILITIES AND CIGS WITH SIGNIFICANT
AREAS OF IFR/LIFR CONDS ACROSS CENTRAL PA. EXPECT CONDS TO IMPROVE
TO VFR BY LATE MORNING...ALBEIT SLOWLY AS WINDS SHIFT TO THE
NW/PICK UP IN SPEED...AND THE UPPER LVL TROUGH MOVES EAST OF THE
AREA.
ISOLATED SHOWERS POSSIBLE AGAIN THIS AFTERNOON...BUT COVERAGE SHOULD
BE LESS THAN YESTERDAY.
SKIES SHOULD CLEAR OUT THIS EVENING. THIS ALONG WITH LIGHT WINDS
SHOULD LEAD TO REDEVELOP OF FOG BEFORE MIDNIGHT IN MANY IF NOT ALL
LOCATIONS.
OUTLOOK...
THU...A.M. FOG AND MVFR VSBYS EARLY...OTHERWISE VFR.
FRI...REDUCED CONDS LIKELY IN PERIODS OF SHOWERS/TSRA
WITH A STRONG COLD FRONT APPROACHING FROM THE WEST.
SAT AND SUN...MAINLY VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/CERU
AVIATION...GARTNER
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1034 AM EDT WED AUG 15 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH TODAY AND LINGERS THROUGH
FRIDAY. A COLD FRONT IS EXPECTED TO MOVE ACROSS THE REGION LATE
FRIDAY AND STALLS JUST SOUTH OF OUR AREA THROUGH THE EARLY PART OF
NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AT 1430 UTC...BIGGEST QUESTION IS HOW MUCH CONVECTIVE ACTIVITY WILL
OCCUR THIS AFTERNOON AS WEAK FRONT MOVES THROUGH THE PIEDMONT AREAS
ALONG WITH A DECENT UPPER SHORT WAVE. MESOSCALE MODELS LIKE THE HRRR
AND LOCAL WRF ARE ADVERTISING SCATTERED COVERAGE FROM THE NORTHERN
MOUNTAINS...SE THROUGH THE NC PIEDMONT AND EASTERN UPSTATE. 12Z NAM
TARGETS THIS SAME AREA WITH ITS QPF RESPONSE...SO WILL TIME AN AREA
OF SCATTERED POPS EASTWARD THROUGH THE AFTERNOON. CHANCES FOR PRECIP
WILL END AFTER 00Z AS UPPER SHORT WAVE/SFC FRONT EXIT TO THE EAST.
THE OTHER CONCERN IS THE SEVERE THREAT. THE NAM AND RAP ARE
FORECASTING SOME VERY HEALTHY SBCAPES OVER THE NC PIEDMONT AND
EASTERN UPSTATE THIS AFTERNOON ON THE ORDER OF 2000J/KG. ALSO...BULK
SHEAR WILL BE ON THE ORDER OF 40KTS. HENCE...A FEW SEVERE STORMS ARE
POSSIBLE OVER THE EASTERN PART OF THE FORECAST AREA. ALSO...MADE
SOME ADJUSTMENTS TO SKY COVER AND TEMP/DEWPOINTS TRENDS.
PREVIOUS DISCUSSION:
AT 300 AM EDT WEDNESDAY...AN MEAN UPPER TROUGH WILL REMAIN IN PLACE
FROM THE GREAT LAKES TO THE NE GULF OF MEXICO TODAY AND TONIGHT. A
WELL DEFINED SHORTWAVE WILL MOVE TROUGH THIS TROUGH EARLY TODAY...
WHILE AN ASSOCIATED SURFACE COLD FRONT CROSSES THE OUR AREA. LOW
LEVEL MOISTURE IS EXPECTED TO INCREASE AHEAD OF THE FRONT...AND POPS
HAVE BEEN RAISED AT MIDDAY AS THE FRONT AND SHORTWAVE PASS BY.
INSTABILITY AND SHEAR APPEAR SUFFICIENT FOR LARGE HAIL AND DAMAGING
WIND...WHICH WILL BE MENTIONED IN THE HAZARDOUS WEATHER OUTLOOK. QPF
IS EXPECTED TO BE RATHER LIMITED AS STORMS WILL BE MOVING...AND WITH
A FEW RAIN FREE DAYS...MOST OF THE AREA SHOULD BE SPARED FROM
FLOODING. MAXIMUM TEMPERATURES WILL BE SLIGHTLY BELOW NORMAL.
FRONTAL PASSAGE LATE THIS AFTERNOON WILL BE FOLLOWED BY DRYING THIS
EVENING. MINIMUM TEMPERATURES WILL BE A COUPLE OF CATEGORIES BELOW
NORMAL.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM EDT WEDNESDAY...ZONAL FLOW DEVELOPS ON THURSDAY AS THE
UPPER TROUGH MOVES OFF TO THE EAST. SURFACE HIGH PRESSURE IS
EXPECTED TO BUILD IN FROM THE NORTH PROVIDING DRY WEATHER AND NEAR
NORMAL TEMPERATURES ON THURSDAY. AFTERNOON HIGHS WILL BE IN THE
UPPER 80S OVER THE PIEDMONT WITH MID 70S TO LOW 80S IN THE HIGHER
TERRAIN. HEIGHTS FALL FRIDAY AS ANOTHER UPPER TROUGH DIVE TOWARD THE
AREA. THIS WILL PUSH A COLD FRONT FROM THE OH VALLEY TO THE
APPALACHIANS BY LATE FRIDAY. EXPECT INSTABILITY TO RETURN WITH
MOISTENING LOW LEVELS AND COOLING MID LEVELS. BEST CHANCE FOR
PRECIPITATION WILL BE OVER THE BLUE RIDGE WHERE MOISTURE AND UPPER
FORCING ARE HIGHER...BUT SCT CONVECTION SHOULD DEVELOP ALL AREAS BY
LATE EVENING/NIGHT. TEMPERATURES WILL BE NEAR NORMAL ON FRIDAY AS
WELL.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 200 AM EDT WEDNESDAY...THE LATEST MEDIUM RANGE MODELS CONTINUE
TO INDICATE THAT A LONG WAVE UPPER TROUGH WILL PERSIST OVER THE
EASTERN CONUS WHILE UPPER RIDGE OF HIGH REMAINS IN PLACE OVER THE
WEST THROUGH THE PERIOD. AT THE SURFACE...A COLD FRONT MOVES ACROSS
OUR CWA SAT...THEN STALLS TO OUR SOUTH AND EAST THROUGH DAY 7. HAVE
CARRIED POPS IN THE 40/50 PERCENT RANGE ON SAT WITH 20/30S SUNDAY.
THERE IS POTENTIAL THAT SEVERE WEATHER COULD DEVELOP ACROSS MUCH OF
OUR CWA ON SAT/SUN AS MODELS CONTINUE TO SHOW STRONG WIND SHEAR
ALOFT AND MODERATE INSTABILITY WITH THE PASSAGE OF A COLD FRONT.
THE LATEST GFS TRIES TO PULL THE FRONT BACK TOWARDS OUR AREA MON/TUE
BUT THE ECMWF KEEPS THE FRONT SOUTH OF THE AREA. DUE TO THE
UNCERTAINTY...I KEPT SLIGHT CHANCE POPS MON/TUE. TEMPERATURES WILL
BE AROUND 3-7 DEGREES BELOW NORMAL AS THE TROUGH PERSISTS THROUGH
THE PERIOD.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT...STRATUS DEVELOPING TO THE W OF THE AIRFIELD.KAKH NOW IS
OVC004. THEREFORE...HAVE UPDATED KCLT TO INDICATE TEMPO BKN005 TIL
14Z. LOW LEVEL MOISTURE WILL INCREASE AHEAD OF A COLD FRONT...AND A
LOW VFR CIG WILL BE CARRIED BY MID MORNING. SCATTERED CONVECTION IS
EXPECTED TO FIRE AHEAD OF THE FRONT EALRY TO MID AFTERNOON AND A
TEMPO GROUP WILL BE CARRIED. WINDS WILL SHIFT FROM SW TO NW WITH
FRONTAL PASSAGE BY LATE AFTERNOON. MODEL TIME HEIGHTS SHOW VERY LOW
MOISTURE THURSDAY MORNING...BUT SKY COVER IS EXPECTED TO BE TOO LOW
FOR A CIG.
ELSEWHERE...IFR OR LOWER FOG AND CIGS HAVE BEEN OBSERVED AT ALL
SITES BUT KAND EARLY THIS MORNING. THE DURATION OF RESTRICTIONS WILL
BE LIMITED BY A COLD FRONT MOVING EAST OF THE AREA. HOWEVER...LIFR
CONDS SHOULD PREVAIL AT KAVL/KHKY TIL ABOUT 14Z. LOW VFR CIGS ARE
EXPECTED BY MID MORNING. SCATTERED CONVECTION IS EXPECTED ALONG THE
FRONT...AND VCTS WILL BE CARRIED AT ALL SITES BY MIDDAY. WINDS WILL
SHIFT THIS AFTERNOON WITH FRONTAL PASSAGE. MODEL TIME HEIGHTS
SUGGEST SOME VERY LOW CLOUDS EARLY THURSDAY MORNING...BUT CLOUD
COVER IS EXPECTED TO BE TOO LIMITED FOR CIG RESTRICTIONS.
OUTLOOK...THE CENTER OF SURFACE HIGH PRESSURE WILL SETTLE OVER THE
REGION THIS EVENING...AND REMAIN THROUGH THE WORK WEEK. A COLD FRONT
WILL BRING SOME MOISTURE TO THE AREA LATE FRIDAY INTO SUNDAY.
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...JOH
NEAR TERM...LG
SHORT TERM...JOH
LONG TERM...JOH
AVIATION...JAT
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
854 AM CDT WED AUG 15 2012
.UPDATE...
PRESSURE IS LOWER OVER EASTERN TN AND INTO NRN AL. THUS...FRONTAL
BOUNDARY HAS PUSHED SOUTHEAST OF THE MID STATE. THE LAST OF THE
PATCHY FOG IS NOW BEGINNING TO BURN OFF ACROSS THE PLATEAU.
FOR TODAY...SEEING NO RETURN OF ANY CONVECTIVE POTENTIAL. AIRMASS
HAS DRIED OUT CONSIDERABLY AND THUS...WILL KEEP TODAY`S FORECAST
POP FREE. HIGH TEMPS IN THE UPPER 80S WEST OF PLATEAU STILL LOOKS
REASONABLE. 18Z MODEL GRAPHICAL TEMPS ARE IN THE LOWER TO MID 80S
SO WILL MAKE NO ADJUSTMENTS. STILL EXPECTING TO SEE A GRADUAL
DECREASE IN CLOUD COVER THROUGH THE DAY. LIGHT NORTHERLY SFC FLOW
TO CONTINUE.
WILL NOT MAKE ANY GRID ADJUSTMENTS BUT WILL RESEND ZONES.
&&
.PREV DISCUSSION... /ISSUED 611 AM CDT WED AUG 15 2012/
AVIATION...
BR WILL CLEAR UP AT KCSV BY 15Z THIS MORNING. UPPER LEVEL
DISTURBANCE MOVING OUT WILL IMPROVE FLIGHT RULES TO VFR EVERYWHERE
BY 15Z. VFR IS ANTICIPATED THROUGHOUT THE NEXT 24 HOURS.
PREV DISCUSSION... /ISSUED 525 AM CDT WED AUG 15 2012/
UPDATE...
UPPER LEVEL SHORTWAVE IS PROGRESSING EAST QUICKLY AND WITH
IT...ITS ASSOCIATED LIGHT RAINFALL. HAVE UPDATED GRIDS TO REMOVE
RW-- BEYOND 13Z. CLOUD COVER SHOULD BEGIN TO DECREASE THROUGHOUT
THE MORNING HOURS. IR SATELLITE SHOWS LOW LEVEL CLOUD COVER
REMAINS ACROSS MIDDLE TN BUT SHOULD LIFT BY 18Z.
PREV DISCUSSION... /ISSUED 352 AM CDT WED AUG 15 2012/
DISCUSSION...
NOT TOO MUCH OF MENTION IN THE SHORT TERM...AN H5 SHORTWAVE IS
PROGGED TO BE PASSING OVER MIDDLE TN EARLY IN THE FIRST PERIOD AND
SHOULD BE CLEAR OF THE CUMBERLAND BY 18Z. RUC FORECAST SOUNDINGS
SHOW VERY MOIST MID AND UPPER LEVELS WITH ADEQUATE LIFT HOWEVER LOW
LEVEL DRYNESS SHOULD PREVENT ANYTHING FROM REACHING THE SURFACE. THE
CUMBERLAND MAY GET A SPRINKLE OR TWO BEFORE 16Z BUT OTHERWISE MID
AND UPPER LEVEL CLOUDINESS SHOULD BE THE ONLY RESULT. ONCE THESE
CLEARS OUT...HIGH PRESSURE...FROM THE SURFACE UP TO 700 MB...WILL
KEEP THE COLUMN DRY AND ALLOW FOR HIGHS TO WARM UP THROUGH THURSDAY.
AS FOR THE LONG TERM...THE FOCUS WILL BE ON AN APPROACHING COLD
FRONT AND ITS ASSOCIATED THUNDERSTORM POSSIBILITIES BY THURSDAY
NIGHT AND THROUGH SATURDAY MORNING. AS THE SURFACE HIGH CURRENTLY
OVER MIDDLE TN TRANSLATES EASTWARD...THE LOW LEVEL WIND FIELD WILL
RETURN TO THE SOUTH AND MOISTURE ADVECTION WILL BEGIN OVERNIGHT
WEDNESDAY. DURING THIS TIME...A PRE FRONTAL TROUGH WILL PASS ACROSS
NORTHERN KY WHICH WILL VEER LOW LEVEL WINDS NEARLY PARALLEL WITH THE
ADVANCING FRONT. THIS SHOULD LIMIT 0-6 KM BULK SHEAR VALUES AND GFS
SEEMS TO AGREE...ONLY SHOWING 20 KT OF UNIDIRECTIONAL SHEAR.
HOWEVER...250MB DIVERGENCE SHOULD BE STRONGEST COINCIDENT WITH THE
FRONT WHICH...COUPLED WITH MOIST ADIABATIC LAPSE RATES NEARLY
THROUGHOUT THE COLUMN WITHOUT A CAP...PW VALUES NEAR 1.75...AND CAPE
VALUES >1500 J/KG...THE INGREDIENTS FOR A SOME STRONG STORMS
EMBEDDED IN A LINE OF WIDESPREAD HEAVY RAIN ARE PRESENT.
DRY AIR BEHIND THE FRONT WILL CAUSE A RAPID DROP OFF IN COVERAGE BY
12Z SATURDAY. THE REST OF THE WEEKEND AND EARLY WORK WEEK SHOULD BE
QUITE PLEASANT WITH HIGHS IN THE LOWER 80S. BY MID
WEEK...TEMPERATURE SHOULD BEGIN TO RISE BACK TO MORE SEASONAL
NORMALS IN THE UPPER 80S.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
611 AM CDT WED AUG 15 2012
.AVIATION...
BR WILL CLEAR UP AT KCSV BY 15Z THIS MORNING. UPPER LEVEL
DISTURBANCE MOVING OUT WILL IMPROVE FLIGHT RULES TO VFR EVERYWHERE
BY 15Z. VFR IS ANTICIPATED THROUGHOUT THE NEXT 24 HOURS.
&&
.PREV DISCUSSION... /ISSUED 525 AM CDT WED AUG 15 2012/
UPDATE...
UPPER LEVEL SHORTWAVE IS PROGRESSING EAST QUICKLY AND WITH
IT...ITS ASSOCIATED LIGHT RAINFALL. HAVE UPDATED GRIDS TO REMOVE
RW-- BEYOND 13Z. CLOUD COVER SHOULD BEGIN TO DECREASE THROUGHOUT
THE MORNING HOURS. IR SATELLITE SHOWS LOW LEVEL CLOUD COVER
REMAINS ACROSS MIDDLE TN BUT SHOULD LIFT BY 18Z.
PREV DISCUSSION... /ISSUED 352 AM CDT WED AUG 15 2012/
DISCUSSION...
NOT TOO MUCH OF MENTION IN THE SHORT TERM...AN H5 SHORTWAVE IS
PROGGED TO BE PASSING OVER MIDDLE TN EARLY IN THE FIRST PERIOD AND
SHOULD BE CLEAR OF THE CUMBERLAND BY 18Z. RUC FORECAST SOUNDINGS
SHOW VERY MOIST MID AND UPPER LEVELS WITH ADEQUATE LIFT HOWEVER LOW
LEVEL DRYNESS SHOULD PREVENT ANYTHING FROM REACHING THE SURFACE. THE
CUMBERLAND MAY GET A SPRINKLE OR TWO BEFORE 16Z BUT OTHERWISE MID
AND UPPER LEVEL CLOUDINESS SHOULD BE THE ONLY RESULT. ONCE THESE
CLEARS OUT...HIGH PRESSURE...FROM THE SURFACE UP TO 700 MB...WILL
KEEP THE COLUMN DRY AND ALLOW FOR HIGHS TO WARM UP THROUGH THURSDAY.
AS FOR THE LONG TERM...THE FOCUS WILL BE ON AN APPROACHING COLD
FRONT AND ITS ASSOCIATED THUNDERSTORM POSSIBILITIES BY THURSDAY
NIGHT AND THROUGH SATURDAY MORNING. AS THE SURFACE HIGH CURRENTLY
OVER MIDDLE TN TRANSLATES EASTWARD...THE LOW LEVEL WIND FIELD WILL
RETURN TO THE SOUTH AND MOISTURE ADVECTION WILL BEGIN OVERNIGHT
WEDNESDAY. DURING THIS TIME...A PRE FRONTAL TROUGH WILL PASS ACROSS
NORTHERN KY WHICH WILL VEER LOW LEVEL WINDS NEARLY PARALLEL WITH THE
ADVANCING FRONT. THIS SHOULD LIMIT 0-6 KM BULK SHEAR VALUES AND GFS
SEEMS TO AGREE...ONLY SHOWING 20 KT OF UNIDIRECTIONAL SHEAR.
HOWEVER...250MB DIVERGENCE SHOULD BE STRONGEST COINCIDENT WITH THE
FRONT WHICH...COUPLED WITH MOIST ADIABATIC LAPSE RATES NEARLY
THROUGHOUT THE COLUMN WITHOUT A CAP...PW VALUES NEAR 1.75...AND CAPE
VALUES >1500 J/KG...THE INGREDIENTS FOR A SOME STRONG STORMS
EMBEDDED IN A LINE OF WIDESPREAD HEAVY RAIN ARE PRESENT.
DRY AIR BEHIND THE FRONT WILL CAUSE A RAPID DROP OFF IN COVERAGE BY
12Z SATURDAY. THE REST OF THE WEEKEND AND EARLY WORK WEEK SHOULD BE
QUITE PLEASANT WITH HIGHS IN THE LOWER 80S. BY MID
WEEK...TEMPERATURE SHOULD BEGIN TO RISE BACK TO MORE SEASONAL
NORMALS IN THE UPPER 80S.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
TB12
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
525 AM CDT WED AUG 15 2012
.UPDATE...
UPPER LEVEL SHORTWAVE IS PROGRESSING EAST QUICKLY AND WITH
IT...ITS ASSOCIATED LIGHT RAINFALL. HAVE UPDATED GRIDS TO REMOVE
RW-- BEYOND 13Z. CLOUD COVER SHOULD BEGIN TO DECREASE THROUGHOUT
THE MORNING HOURS. IR SATELLITE SHOWS LOW LEVEL CLOUD COVER
REMAINS ACROSS MIDDLE TN BUT SHOULD LIFT BY 18Z.
&&
.PREV DISCUSSION... /ISSUED 352 AM CDT WED AUG 15 2012/
DISCUSSION...
NOT TOO MUCH OF MENTION IN THE SHORT TERM...AN H5 SHORTWAVE IS
PROGGED TO BE PASSING OVER MIDDLE TN EARLY IN THE FIRST PERIOD AND
SHOULD BE CLEAR OF THE CUMBERLAND BY 18Z. RUC FORECAST SOUNDINGS
SHOW VERY MOIST MID AND UPPER LEVELS WITH ADEQUATE LIFT HOWEVER LOW
LEVEL DRYNESS SHOULD PREVENT ANYTHING FROM REACHING THE SURFACE. THE
CUMBERLAND MAY GET A SPRINKLE OR TWO BEFORE 16Z BUT OTHERWISE MID
AND UPPER LEVEL CLOUDINESS SHOULD BE THE ONLY RESULT. ONCE THESE
CLEARS OUT...HIGH PRESSURE...FROM THE SURFACE UP TO 700 MB...WILL
KEEP THE COLUMN DRY AND ALLOW FOR HIGHS TO WARM UP THROUGH THURSDAY.
AS FOR THE LONG TERM...THE FOCUS WILL BE ON AN APPROACHING COLD
FRONT AND ITS ASSOCIATED THUNDERSTORM POSSIBILITIES BY THURSDAY
NIGHT AND THROUGH SATURDAY MORNING. AS THE SURFACE HIGH CURRENTLY
OVER MIDDLE TN TRANSLATES EASTWARD...THE LOW LEVEL WIND FIELD WILL
RETURN TO THE SOUTH AND MOISTURE ADVECTION WILL BEGIN OVERNIGHT
WEDNESDAY. DURING THIS TIME...A PRE FRONTAL TROUGH WILL PASS ACROSS
NORTHERN KY WHICH WILL VEER LOW LEVEL WINDS NEARLY PARALLEL WITH THE
ADVANCING FRONT. THIS SHOULD LIMIT 0-6 KM BULK SHEAR VALUES AND GFS
SEEMS TO AGREE...ONLY SHOWING 20 KT OF UNIDIRECTIONAL SHEAR.
HOWEVER...250MB DIVERGENCE SHOULD BE STRONGEST COINCIDENT WITH THE
FRONT WHICH...COUPLED WITH MOIST ADIABATIC LAPSE RATES NEARLY
THROUGHOUT THE COLUMN WITHOUT A CAP...PW VALUES NEAR 1.75...AND CAPE
VALUES >1500 J/KG...THE INGREDIENTS FOR A SOME STRONG STORMS
EMBEDDED IN A LINE OF WIDESPREAD HEAVY RAIN ARE PRESENT.
DRY AIR BEHIND THE FRONT WILL CAUSE A RAPID DROP OFF IN COVERAGE BY
12Z SATURDAY. THE REST OF THE WEEKEND AND EARLY WORK WEEK SHOULD BE
QUITE PLEASANT WITH HIGHS IN THE LOWER 80S. BY MID
WEEK...TEMPERATURE SHOULD BEGIN TO RISE BACK TO MORE SEASONAL
NORMALS IN THE UPPER 80S.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
TB12
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
448 PM EDT WED AUG 15 2012
.SYNOPSIS...
A FRONTAL BOUNDARY WILL MOVE THROUGH THE REGION LATE TODAY AND
TONIGHT...AND STALL JUST TO OUR SOUTH THURSDAY. DRIER AIR ENTERING
THE REGION BEHIND THE FRONT IS EXPECTED TO PROVIDE FAIR WEATHER
THURSDAY. MOISTURE RETURN WILL GRADUALLY RESUME FRIDAY AHEAD OF
ANOTHER FRONT THAT WILL DROP INTO THE REGION SATURDAY...AND THEN
STALL IN PLACE INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
THIS AFTERNOON...SHORT WAVE IN UPSTATE MOVING EAST APPEARS TO
WEAKEN AS IT MOVES OVER NORTHERN PORTION OF FORECAST AREA. THERE
IS CURRENTLY A NARROW BAND OF SHOWERS ENTERING THE NORTHERN
PORTION OF THE FORECAST AREA AS A WEAK COLD FRONT MOVES WEST TO
EAST ACROSS THE AREA BY LATE THIS AFTERNOON. BOTH RUC13 AND LOCAL
4 KM WRF KEEP PRECIP CONFINED TO THE NORTH AND EAST PORTIONS OF
REGION. HOWEVER...DECIDED TO GO AT LEAST 20 PERCENT CHANCE MOST
LOCATIONS. IN ADDITION...ADDED A 30 PERCENT CHANCE NORTH OF CAE
FOR A 2-3 HOUR PERIOD. THIS MATCHES UP WELL WITH GSP. SPC EARLIER
HAD A SLIGHT RISK OF SEVERE STORMS IN THE EASTERN PART OF THE
FORECAST AREA BUT HAS SINCE MOVED IT WELL TO THE EAST. MODELS KEEP
ENERGY MAINLY TO THE NORTH. MOST UNSTABLE LOCATIONS WILL BE TO THE
EAST. CLOUDS HAVE BROKEN UP AS NAM BUFR SHOWS DRIER AIR MOVING IN.
PW VALUES DROP BELOW 1.5 INCHES. STILL SUNSHINE IN THE EAST MAY
LEAD TO STRONGER LOW LEVEL LAPSE RATES AND HIGHER CAPES. HIGH
READINGS MAINLY IN LOWER 90S STILL OK.
TONIGHT...A TRAILING SHORT WAVE IS EXPECTED TO MOVE THROUGH TO
THE SOUTHEAST TOWARD THE COAST BY THIS EVENING. HAVE SLIGHT CHANCE
EAST OF CAE UNTIL ABOUT 02Z. THINK ATMOSPHERE WILL BE TOO STABLE
FOR STRONG STORMS. THE ACTIVITY SHOULD DIMINISH AS THE COLD FROM
MOVES INTO THE LOW COUNTRY. IN GOOD AGREEMENT WITH MOS LOW
TEMPERATURES IN THE UPPER 60S TO LOWER 70S.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
UPPER RIDGE WILL CONTINUE OVER THE WESTERN CONUS...AS CLOSED UPPER
LOW REMAINS NEARLY STATIONARY OVER ONTARIO WITH TROUGHINESS
EXTENDING SOUTH INTO THE SE US. SURFACE FRONT WILL PUSH JUST TO THE
SOUTH OF OUR FORECAST AREA THURSDAY...WITH WEAK SURFACE HIGH
PRESSURE OVER OUR REGION. DRIER AIR WILL PREVENT CONVECTION. THERE
ARE SOME INDICATIONS OF POSSIBLE CONVECTION ALONG THE FRONT LATE
THU AFTN OR EVE JUST TO OUR SOUTH...BUT CURRENT INDICATIONS ARE
THAT IT WILL STAY JUST SOUTH OF OUR FA. NEXT WEAK FRONT AND WEAK
UPPER DISTURBANCE TO APPROACH FROM THE NW FRIDAY...WITH JUST
ENOUGH MOISTURE INCREASE FROM THE SOUTH AHEAD OF IT TO WARRANT
SLIGHT CHANCE POPS.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
LITTLE CHANGE IN THE UPPER PATTERN...WITH RIDGE WEST AND TROUGH EAST
AS UPPER LOW IS PROGGED TO CONTINUE SPINNING OVER ONTARIO/HUDSON BAY
REGION. A SERIES OF UPPER DISTURBANCES ROTATING AROUND THE LOW WILL
MOVE SE INTO THE EASTERN CONUS...WITH TROUGH DEEPENING SLIGHTLY WITH
TIME. GFS/ECMWF BRING SURFACE FRONT INTO THE REGION SATURDAY AND
STALL IT OVER OUR REGION INTO EARLY NEXT WEEK. PLENTIFUL ATMOSPHERIC
MOISTURE AND A SERIES OF UPPER DISTURBANCES WILL PROVIDE AT LEAST
CHANCE POPS THROUGH THE PERIOD. GENERALLY ACCEPTED HPC GUIDANCE.
&&
.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
EXPECT MAINLY VFR CONDITIONS DURING THE TAF PERIOD. HIGH CLOUDINESS TODAY
HAS HELPED LIMIT INSTABILITY. MOST OF THE UPPER-LEVEL LIFT HAS
REMAINED NORTH OF THE FORECAST AREA. EXPECT ANY THUNDERSTORMS LATE
THIS AFTERNOON AND EVENING WILL REMAIN ISOLATED WITH THE CHANCE TOO
LOW TO INCLUDE IN THE TERMINAL FORECASTS AT THIS TIME. A RELATIVELY
DRY AIR MASS AND A LITTLE MIXING SHOULD LIMIT FOG. HOWEVER...FOG MAY
OCCUR DURING THE EARLY MORNING HOURS BECAUSE OF SOME CONVERGENCE
ALONG THE WEAK FRONT. THE FOG POTENTIAL APPEARS GREATER AT THE RIVER
VALLEY TERMINALS OF AGS AND OGB. USED THE GFS LAMP AND FORECASTED A
PERIOD OF MVFR FOG. HEATING AND MIXING SHOULD HELP DISSIPATE ANY FOG
AFTER 14Z.
EXTENDED AVIATION OUTLOOK...EXPECT RESTRICTIONS IN SCATTERED
THUNDERSTORMS AHEAD OF A COLD FRONT FRIDAY AND FRIDAY NIGHT.
THE FRONT WILL LIKELY STALL NEAR THE AREA SATURDAY AND REMAIN
THROUGH MONDAY. WIDESPREAD LOW CLOUDINESS AND FOG MAY OCCUR
ESPECIALLY DURING THE EARLY MORNING HOURS BECAUSE OF MOISTURE
ASSOCIATED WITH THE FRONT. THERE SHOULD ALSO BE SCATTERED
THUNDERSTORMS.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
358 PM EDT WED AUG 15 2012
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE AND ASSOCIATED COLD FRONT WILL MOVE
TOWARD THE REGION THIS EVENING. THE FRONT WILL CONTINUE TO SLOWLY
MOVE SOUTHEAST BEFORE DISSIPATING ALONG THE COAST ON THURSDAY. A
STRONGER COLD FRONT WILL APPROACH FROM THE NORTHWEST ON FRIDAY
THEN LINGER ALONG THE SOUTHEAST COAST THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
ISOLATED CONVECTION STILL GOING OVER THE EXTREME SOUTHEAST
FORECAST AREA...WITH CONVECTION STRUGGLING TO FORM ELSE WHERE.
SEEING A HINT OF VERY WEAK CONVECTION/SHOWERS TRYING TO FORM ALONG
THE SEA BREEZE...WHICH IS PINNED CLOSE TO THE COAST. STILL NO
CONVECTION UPSTREAM OF THE REGION OVER THE SC. CONVECTION LIKELY
INHIBITED SO FAR DUE TO LOWER CLOUD DECK THIS MORNING...WHICH HAS
SLOWED TEMP RISE. STILL EXPECTING ISOLATED TO SCATTERED SHOWERS
AND THUNDERSTORMS TO DEVELOP ACROSS THE REGION...BUT NOT SURE IF
IT WILL TRY TO DEVELOP CLOSER TO THE COAST WITH THE SEA
BREEZE...OR FURTHER INLAND WITH THE APPROACHING FRONT AND UPPER
TROUGH. HAVE KEPT LOW END CHANCE POPS FOR MAINLY THE NORTHERN HALF
OF THE REGION THROUGH THIS EVENING.
LATEST RUC ANALYSES SHOW HIGH VALUES OF DOWNDRAFT CAPE /1100-1300
J/KG/ ACROSS THE EASTERN PORTIONS OF SC AND GA. THIS ALONG WITH
BULK SHEAR VALUES OF 25-30 KTS AND MIXED LAYER CAPE VALUES OF
3000-3500 J/KG WILL MEAN THERE IS STILL A CHANCE FOR ISOLATED
SEVERE STORMS THROUGH THIS EVENING. HOWEVER...CONFIDENCE IN THE
SEVERE WEATHER PROBABILITIES CONTINUE TO BE LOW GIVEN CURRENT
LACK OF OVERALL CONVECTION THIS LATE IN THE AFTERNOON. IF STORMS
BECOME STRONG/SEVERE...IT WILL BE MUCH LATER THIS AFTERNOON AND
INTO EARLY EVENING...AND LIKELY OVER THE EASTERN 1/3 OF THE SC
FORECAST AREA.
TONIGHT...EXPECT ANY CONVECTION TO DISSIPATE AS IT MOVE EASTWARD
ALONG WITH THE UPPER SHORTWAVE AXIS WELL TO THE NORTH. MIN TEMPS
PRETTY CLOSE TO SEASONAL NORMALS...GENERALLY IN THE LOWER TO MID
70S.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
ANOTHER IN A SERIES OF WEAK MID LEVEL DISTURBANCES MOVING THROUGH
THE LARGER SCALE TROFFINESS IN THE EASTERN HALF OF NORTH AMERICA
WILL PASS THROUGH THE REGION ON THURSDAY. HOWEVER...THE DISTURBANCE
WILL BE WEAKENING A BIT AS IT MOVES THROUGH...AND THE WEAK SURFACE
FRONT WILL STALL OVER THE MIDLANDS AND ESSENTIALLY BECOME A LEE
TROF...LIMITING SURFACE CONVERGENCE TO LOCATIONS NEAR THE COAST. FOR
THAT REASON...THE BEST CHANCE OF AFTERNOON CONVECTION LOOKS TO BE
NEAR THE BEACHES WITH THE SEA BREEZE PINNED.
FRIDAY IS A BIT TRICKIER. UPPER FLOW FLATTENS OUT A BIT BETWEEN
SYSTEMS...BUT THE LEE TROF LOOKS LIKE IT COULD BECOME MORE ACTIVE
LATER IN THE AFTERNOON. FOR THAT REASON...THE BEST CHANCE OF POPS
WILL SHIFT TO INLAND LOCATIONS. ANY CONVECTION WILL PROBABLY HOLD
OFF UNTIL LATER IN THE DAY INTO THE EVENING WITH THE LACK OF ANY
SYNOPTIC SCALE FORCING.
FRIDAY COULD ALSO GET A BIT WARMER THAN I CURRENTLY HAVE IN THE
FORECAST WITH HEAT INDICES ECLIPSING THE 100 MARK IN QUITE A FEW
LOCATIONS...BUT I THINK THEY WILL STAY BELOW ANY ADVISORY CRITERIA.
BY SATURDAY...EIGHTS LOWER AGAIN IN RESPONSE TO A STRONGER SHORTWAVE
DIGGING INTO THE EAST. THE CHANCES OF AFTERNOON CONVECTION WILL GO
UP WITH MORE FORCING...ESPECIALLY DURING THE LATE AFTERNOON AND
EVENING HOURS AS A 100 KNOT UPPER JET MOVES INTO THE OHIO RIVER
VALLEY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MEDIUM RANGE GUIDANCE IS IN GOOD AGREEMENT INDICATING AN UNSETTLED
PATTERN FOR MOST OF THE LONG TERM PERIOD. BROAD UPPER LEVEL
TROUGHING WILL PERSIST ACROSS THE EASTERN UNITED STATES INTO THE
MIDDLE OF NEXT WEEK...WITH A COLD FRONT GETTING HUNG UP ALONG THE
SOUTHEAST COAST. SEVERAL WAVES OF LOW PRESSURE PASSING ALONG THE
FRONT WILL CAUSE THE FRONT TO OSCILLATE BACK AND FORTH ACROSS THE
AREA THROUGH MOST OF THE PERIOD. CHANNELED VORTICITY ALONG THE
EASTERN PERIPHERY OF THE TROUGH COMBINED WITH AN AXIS OF DEEP
MOISTURE OVER THE AREA WILL RESULT IN A SOLID CHANCE OF SHOWERS AND
THUNDERSTORMS THROUGH THE MIDDLE OF NEXT WEEK. HIGH TEMPERATURES
WILL TREND SLIGHTLY BELOW NORMAL THROUGH THE LONG TERM PERIOD.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
VFR THROUGH TONIGHT AT BOTH KSAV AND KCHS. THE LATE MORNING
STRATUS DECK HAS BEGUN TO DRY OUT AS THE COLD FRONT PUSHES IN FROM
THE NORTHWEST. NUMERICAL MODEL SOLUTIONS SUGGEST ISOLATED TO
SCATTERED TSTMS WILL DEVELOP THIS AFTERNOON...AND HAVE THEREFORE
INCLUDED VCTS AT THE TERMINALS. EXPECT MOST OF THE ACTIVITY AROUND
KCHS. KEEPING VCTS IN BOTH TAFS DUE TO THE MODELS BACKING OFF ON
COVERAGE.
EXTENDED AVIATION OUTLOOK...SCATTERED SHOWERS AND THUNDERSTORMS...
MAINLY DURING THE AFTERNOON/EVENING HOURS...COULD RESULT IN
TEMPORARY REDUCTIONS IN CIGS/VSBYS FRIDAY THROUGH SUNDAY.
OTHERWISE...VFR CONDITIONS ARE EXPECTED TO PREVAIL.
&&
.MARINE...
NO HIGHLIGHTS EXPECTED THROUGH TONIGHT. SOME MODELS SHOWING WINDS
BRIEFING SURGING TO 15-20 KTS OVER THE SC WATERS...BUT HAVE
DECIDED TO KEEP FORECAST IN THE 10-15 KT RANGE FOR NOW. SEAS
GENERALLY 3 FEET OR LESS. SCATTERED SHOWERS AND THUNDERSTORM
POSSIBLE...MAINLY LATER THIS EVENING AS A WEAK FRONT APPROACHES
THE AREA FROM THE WEST.
THURSDAY AND INTO THIS WEEKEND...WINDS WILL BE GENERALLY OUT OF THE
SOUTHWEST WITH AN ONSHORE COMPONENT NEAR THE COAST. WINDS AND SEAS
WILL BE WELL BELOW AND HEADLINE CRITERIA WITH MAXIMUM SPEEDS MAYBE
JUST A BIT ABOVE 15 KNOTS LATE EACH EVENING INTO THE EARLY MORNING
HOURS.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...RFM
SHORT TERM...ALSHEIMER
LONG TERM...JAQ
AVIATION...BDC/RFM
MARINE...ALSHEIMER/RFM/JAQ
AREA FORECAST DISCUSSION...CORRECTED
NWS COLUMBIA SC
311 PM EDT WED AUG 15 2012
.SYNOPSIS...
A FRONTAL BOUNDARY WILL MOVE THROUGH THE REGION LATE TODAY AND
TONIGHT...AND STALL JUST TO OUR SOUTH THURSDAY. DRIER AIR ENTERING
THE REGION BEHIND THE FRONT IS EXPECTED TO PROVIDE FAIR WEATHER
THURSDAY. MOISTURE RETURN WILL GRADUALLY RESUME FRIDAY AHEAD OF
ANOTHER FRONT THAT WILL DROP INTO THE REGION SATURDAY...AND THEN
STALL IN PLACE INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
THIS AFTERNOON...SHORT WAVE IN UPSTATE MOVING EAST APPEARS TO
WEAKEN AS IT MOVES OVER NORTHERN PORTION OF FORECAST AREA. THERE
IS CURRENTLY A NARROW BAND OF SHOWERS ENTERING THE NORTHERN
PORTION OF THE FORECAST AREA AS A WEAK COLD FRONT MOVES WEST TO
EAST ACROSS THE AREA BY LATE THIS AFTERNOON. BOTH RUC13 AND LOCAL
4 KM WRF KEEP PRECIP CONFINED TO THE NORTH AND EAST PORTIONS OF
REGION. HOWEVER...DECIDED TO GO AT LEAST 20 PERCENT CHANCE MOST
LOCATIONS. IN ADDITION...ADDED A 30 PERCENT CHANCE NORTH OF CAE
FOR A 2-3 HOUR PERIOD. THIS MATCHES UP WELL WITH GSP. SPC EARLIER
HAD A SLIGHT RISK OF SEVERE STORMS IN THE EASTERN PART OF THE
FORECAST AREA BUT HAS SINCE MOVED IT WELL TO THE EAST. MODELS KEEP
ENERGY MAINLY TO THE NORTH. MOST UNSTABLE LOCATIONS WILL BE TO THE
EAST. CLOUDS HAVE BROKEN UP AS NAM BUFR SHOWS DRIER AIR MOVING IN.
PW VALUES DROP BELOW 1.5 INCHES. STILL SUNSHINE IN THE EAST MAY
LEAD TO STRONGER LOW LEVEL LAPSE RATES AND HIGHER CAPES. HIGH
READINGS MAINLY IN LOWER 90S STILL OK.
TONIGHT...A TRAILING SHORT WAVE IS EXPECTED TO MOVE THROUGH TO
THE SOUTHEAST TOWARD THE COAST BY THIS EVENING. HAVE SLIGHT CHANCE
EAST OF CAE UNTIL ABOUT 02Z. THINK ATMOSPHERE WILL BE TOO STABLE
FOR STRONG STORMS. THE ACTIVITY SHOULD DIMINISH AS THE COLD FROM
MOVES INTO THE LOW COUNTRY. IN GOOD AGREEMENT WITH MOS LOW
TEMPERATURES IN THE UPPER 60S TO LOWER 70S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
UPPER RIDGE WILL CONTINUE OVER THE WESTERN CONUS...AS CLOSED UPPER
LOW REMAINS NEARLY STATIONARY OVER ONTARIO WITH TROUGHINESS
EXTENDING SOUTH INTO THE SE US. SURFACE FRONT WILL PUSH JUST TO THE
SOUTH OF OUR FORECAST AREA THURSDAY...WITH WEAK SURFACE HIGH
PRESSURE OVER OUR REGION. DRIER AIR WILL PREVENT CONVECTION. THERE
ARE SOME INDICATIONS OF POSSIBLE CONVECTION ALONG THE FRONT LATE
THU AFTN OR EVE JUST TO OUR SOUTH...BUT CURRENT INDICATIONS ARE
THAT IT WILL STAY JUST SOUTH OF OUR FA. NEXT WEAK FRONT AND WEAK
UPPER DISTURBANCE TO APPROACH FROM THE NW FRIDAY...WITH JUST
ENOUGH MOISTURE INCREASE FROM THE SOUTH AHEAD OF IT TO WARRANT
SLIGHT CHANCE POPS.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
LITTLE CHANGE IN THE UPPER PATTERN...WITH RIDGE WEST AND TROUGH EAST
AS UPPER LOW IS PROGGED TO CONTINUE SPINNING OVER ONTARIO/HUDSON BAY
REGION. A SERIES OF UPPER DISTURBANCES ROTATING AROUND THE LOW WILL
MOVE SE INTO THE EASTERN CONUS...WITH TROUGH DEEPENING SLIGHTLY WITH
TIME. GFS/ECMWF BRING SURFACE FRONT INTO THE REGION SATURDAY AND
STALL IT OVER OUR REGION INTO EARLY NEXT WEEK. PLENTIFUL ATMOSPHERIC
MOISTURE AND A SERIES OF UPPER DISTURBANCES WILL PROVIDE AT LEAST
CHANCE POPS THROUGH THE PERIOD. GENERALLY ACCEPTED HPC GUIDANCE.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
THE WEAK FRONTAL BOUNDARY WAS SITUATED IN THE NORTHERN PART
OF THE FORECAST AREA EARLY THIS AFTERNOON. THERE IS A BAND
OF SHOWERS CURRENTLY IN ADVANCE OF THE FRONT. LIGHTNING DETECTION
IS SHOWING NO LIGHTNING PRESENTLY. THIS FRONT WILL MOVE EAST AND
AWAY BY THIS EVENING. WESTERLY WINDS CONTINUE TO BRING DRIER AIR
TO THE REGION. THE THREAT OF THUNDERSTORMS HAS GREATLY DIMINISHED
OVER THE PAST COUPLE OF HOURS. MAINLY VFR CONDITIONS ARE EXPECTED
AT TAF SITES. LEFT OUT MENTION OF SHOWERS AND THUNDERSTORMS.
HOWEVER...AN ISOLATED SHOWER OR THUNDERSTORMS MAY BRING BRIEF
IFR-MVFR CONDITIONS. AFTER 00Z...EXPECT VFR CONDITIONS FOR THE
REST OF THE NIGHT AS LOW LEVEL WESTERLY WINDS PROVIDE DRIER WITH
VERY LITTLE OR NO FOG EXPECTED AT DAYBREAK THURSDAY. THURSDAY
WILL BE MOSTLY CLEAR WITH GOOD VISIBILITIES.
EXTENDED AVIATION OUTLOOK...SCATTERED THUNDERSTORMS SATURDAY
THROUGH MONDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
137 PM EDT WED AUG 15 2012
.SYNOPSIS...
A FRONTAL BOUNDARY WILL MOVE THROUGH THE REGION LATE TODAY AND
TONIGHT...AND STALL JUST TO OUR SOUTH THURSDAY. DRIER AIR ENTERING
THE REGION BEHIND THE FRONT IS EXPECTED TO PROVIDE FAIR WEATEHR
THURSDAY. MOISTURE RETURN WILL GRADUALLY RESUME FRIDAY AHEAD OF
ANOTHER FRONT THAT WILL DROP INTO THE REGION SATURDAY...AND THEN
STALL IN PLACE INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
.THIS AFTERNOON...SHORT WAVE IN UPSTATE MOVING EAST APPEARS TO
WEAKEN AS IT MOVES OVER NORTHERN PORTION OF FORECAST AREA. THERE
IS CURRENTLY A NARROW BAND OF SHOWERS ENTERING THE NORTHERN
PORTION OF THE FORECAST AREA AS A WEAK COLD FRONT MOVES WEST
TO EAST ACROSS THE AREA BY LATE THIS AFTERNOON. BOTH RUC13 AND
LOCAL 4 KM WRF KEEP PRECIP CONFINED TO THE NORTH AND EAST PORTIONS
OF REGION. HOWEVER...DECIDED TO GO AT LEAST 20 PERCENT CHANCE MOST
LOCATIONS. IN ADDITION...ADDED A 30 PERCENT CHANCE NORTH OF CAE FOR
A 2-3 HOUR PERIOD. THIS MATCHES UP WELL WITH GSP. SPC EARLIER HAD A
SLIGHT RISK OF SEVERE STORMS IN THE EASTERN PART OF THE FORECAST
AREA BUT HAS SINCE MOVED IT WELL TO THE EAST. MODELS KEEP ENERGY
MAINLY TO THE NORTH. MOST UNSTABLE LOCATIONS WILL BE TO THE EAST.
CLOUDS HAVE BROKEN UP AS NAM BUFR SHOWS DRIER AIR MOVING IN. PW
VALUES DROP BELOW 1.5 INCHES. STILL SUNSHINE IN THE EAST MAY LEAD
TO STRONGER LOW LEVEL LAPSE RATES AND HIGHER CAPES. HIGH READINGS
MAINLY IN LOWER 90S STILL OK.
.TONIGHT...A TRAILING SHORT WAVE IS EXPECTED TO MOVE THROUGH
TO THE SOUTHEAST TOWARD THE COAST BY THIS EVENING. HAVE SLIGHT
CHANCE EAST OF CAE UNTIL ABOUT 02Z. THINK ATMOSPHERE WILL BE
TOO STABLE FOR STRONG STORMS. THE ACTIVITY SHOULD DIMINISH AS THE
COLD FROM MOVES INTO THE LOW COUNTRY. IN GOOD AGREEMENT WITH MOS LOW
TEMPERATURES IN THE UPPER 60S TO LOWER 70S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
UPPER RIDGE WILL CONTINUE OVER THE WESTERN CONUS...AS CLOSED UPPER
LOW REMAINS NEARLY STATIONARY OVER ONTARIO WITH TROUGHINESS
EXTENDING SOUTH INTO THE SE US. SURFACE FRONT WILL PUSH JUST TO THE
SOUTH OF OUR FORECAST AREA THURSDAY...WITH WEAK SURFACE HIGH
PRESSURE OVER OUR REGION. DRIER AIR WILL PREVENT CONVECTION. THERE
ARE SOME INDICATIONS OF POSSIBLE CONVECTION ALONG THE FRONT LATE
THU AFTN OR EVE JUST TO OUR SOUTH...BUT CURRENT INDICATIONS ARE
THAT IT WILL STAY JUST SOUTH OF OUR FA. NEXT WEAK FRONT AND WEAK
UPPER DISTURBANCE TO APPROACH FROM THE NW FRIDAY...WITH JUST
ENOUGH MOISTURE INCREASE FROM THE SOUTH AHEAD OF IT TO WARRANT
SLIGHT CHANCE POPS.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
LITTLE CHANGE IN THE UPPER PATTERN...WITH RIDGE WEST AND TROUGH EAST
AS UPPER LOW IS PROGGED TO CONTINUE SPINNING OVER ONTARIO/HUDSON BAY
REGION. A SERIES OF UPPER DISTURBANCES ROTATING AROUND THE LOW WILL
MOVE SE INTO THE EASTERN CONUS...WITH TROUGH DEEPENING SLIGHTLY WITH
TIME. GFS/ECMWF BRING SURFACE FRONT INTO THE REGION SATURDAY AND
STALL IT OVER OUR REGION INTO EARLY NEXT WEEK. PLENTIFUL ATMOSPHERIC
MOISTURE AND A SERIES OF UPPER DISTURBANCES WILL PROVIDE AT LEAST
CHANCE POPS THROUGH THE PERIOD. GENERALLY ACCEPTED HPC GUIDANCE.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
THE WEAK FRONTAL BOUNDARY WAS SITUATED IN THE NORTHERN PART
OF THE FORECAST AREA EARLY THIS AFTERNOON. THERE IS A BAND
OF SHOWERS CURRENTLY IN ADVANCE OF THE FRONT. LIGHTNING DETECTION
IS SHOWING NO LIGHTNING PRESENTLY. THIS FRONT WILL MOVE EAST AND
AWAY BY THIS EVENING. WESTERLY WINDS CONTINUE TO BRING DRIER AIR
TO THE REGION. THE THREAT OF THUNDERSTORMS HAS GREATLY DIMINISHED
OVER THE PAST COUPLE OF HOURS. MAINLY VFR CONDITIONS ARE EXPECTED
AT TAF SITES. LEFT OUT MENTION OF SHOWERS AND THUNDERSTORMS.
HOWEVER...AN ISOLATED SHOWER OR THUNDERSTORMS MAY BRING BRIEF
IFR-MVFR CONDITIONS. AFTER 00Z...EXPECT VFR CONDITIONS FOR THE
REST OF THE NIGHT AS LOW LEVEL WESTERLY WINDS PROVIDE DRIER WITH
VERY LITTLE OR NO FOG EXPECTED AT DAYBREAK THURSDAY. THURSDAY
WILL BE MOSTLY CLEAR WITH GOOD VISIBILITIES.
EXTENDED AVIATION OUTLOOK...SCATTERED THUNDERSTORMS SATURDAY
THROUGH MONDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1212 PM CDT WED AUG 15 2012
...UPDATE TO AVIATION FOR 18Z TAFS...
.SYNOPSIS...
ISSUED AT 1010 AM CDT WED AUG 15 2012
THE 15.12Z 250 HPA MAP SHOWED THAT A 50-60 KT JET EXTENDED FROM KSLC
(SALT LAKE CITY, UT)...ACROSS OUR REGION (KDDC (DODGE CITY, KS)) AND
EVENTUALLY ACROSS MUCH OF THE EASTERN SEABOARD. THIS JET STRENGTHENED
TO 75 KT ACROSS NEW ENGLAND. ELSEWHERE, THERE WAS ANOTHER 50-75 KT JET
FROM ALBERTA SOUTHWARD TO MONTANA. AT 500 HPA, THE GEOPOTENTIAL HEIGHT
PATTERN INDICATED A FEW SHORTWAVE TROUGHS ACROSS NORTH AMERICA. THE
FIRST WAS A POSITIVELY TILTED TROF FROM MONTANA NORTHWARD INTO CENTRAL
CANADA. ANOTHER TROF WAS FROM JUST SOUTH OF SW KANSAS AND ACROSS THE
EASTERN 2/3RDS OF THE COUNTRY. ANOTHER SHORTWAVE TROF WAS LOCATED ACROSS
THE GREAT LAKES. 500 HPA SHORTWAVE RIDGING WAS SEEN ACROSS THE GREAT
BASIN. 500 HPA TEMPERATURES WERE FAIRLY SEASONAL ALTHOUGH THERE WAS
A SLIGHTLY COLDER POOL OF AIR ACROSS OKLAHOMA AROUND -10 DEG C ASSOCIATED
WITH THE AFOREMENTIONED TROF. AT 700 HPA, A WARM PLUME OF 15 DEG C TEMPS
WERE OBSERVED ACROSS THE GREAT BASIN AND ROCKIES. THERE WERE COOLER
LOW TO MID LEVEL TEMPS SOUTH OF THE REGION ASSOCIATED WITH A TROF. THE
COOLEST TEMPERATURES WERE ACROSS ALBERTA IN THE WAKE OF A SYNOPTIC WAVE
WITH VALUES AS LOW AS -3 DEG C. AT 850 HPA, A WARM PLUME WITH TEMPS
IN THE 25 TO 28 DEG C RANGE EXTENDED FROM KLBF (NORTH PLATTE, NE) TO
KUNR (RAPID CITY, SD). MUCH COOLER TEMPERATURES IN THE 5 TO 10 DEG C
RANGE WERE OBSERVED BEHIND A LOW LEVEL COLD FRONT ACROSS MONTANA AND
THE CANADIAN PRAIRIE PROVINCES. AT THE SURFACE, A WEAK LOW PRESSURE
CENTER WAS LOCATED ACROSS SOUTHERN MANITOBA. A COLD FRONT ASSOCIATED
WITH THIS PRESSURE PERTURBATION EXTENDED FROM THE LOW TO NORTHEAST WYOMING.
COOLER SURFACE TEMPERATURES IN THE UPPER 40S TO LOWER 60S DEG F WERE
ASSOCIATED IN THE WAKE OF THE FRONT. ANOTHER FRONTAL BOUNDARY WAS SOUTH
OF KANSAS (ACROSS TEXAS) WITH DEWPOINTS RUNNING IN THE 70S DEG F SOUTH
OF SAID BOUNDARY.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 430 AM CDT WED AUG 15 2012
FOG WILL BE A PROBLEM THIS MORNING. THE SURFACE LAYER OF MOISTURE IS
QUITE SHALLOW, AND JUST HOW DENSE AND WIDESPREAD THE FOG WILL BECOME
HAS NOT BEEN DETERMINED AT THIS TIME. THE HRRR CAPTURED THE INITIAL
DEVELOPMENT ACROSS CLARK-MEADE-FORD AND GRAY COUNTIES VERY WELL BUT
THE VISIBILITIES HAD BEEN SLOW TO BECOME DENSE. THE SHALLOW NATURE
OF THE MOISTURE MAY JUST PREVENT THAT TOO, HOWEVER, A WIDE AREA OF
DEW POINT DEPRESSIONS BELOW 3 DEGREES HAVE BEEN OBSERVED BETWEEN
HIGHWAYS 83 AND 283.
FOG SHOULD RAPIDLY DISSIPATE AFTER SUNRISE AS SOUTHWEST KANSAS IN
UNDER A CLEAR SKY. SURFACE WINDS WILL REMAIN SOUTHEASTERLY AND
LIGHT, BUT BEGIN TO GUST SLIGHTLY AS VERTICAL MIXING COMMENCES. WITH
MORE INSOLATION TODAY AND A SLIGHT MORE WARM ADVECTION, TEMPERATURES
THIS AFTERNOON SHOULD BE SEVERAL DEGREES WARMER ON AVERAGE THAN THE
PREVIOUS DAY. WIDESPREAD HIGHS IN THE UPPER 90S WITH POTENTIAL TO
TEST 100 DEGREES IS POSSIBLE.
A COLD FRONT WILL ENTER THE AREA TONIGHT, IN THE MID EVENING HOURS AS
DEPICTED BY THE NAM/WRF. THE MODEL APPEARS RELATIVELY DRY AT LEAST
INITIALLY WITH RESPECT TO CONVECTIVE DEVELOPMENT. SURFACE BASED
INSTABILITY IS WEAK TO MODERATE IN THE WARM SECTOR, AND GIVEN THE STEEP
MID LEVEL LAPSE RATES, THE MUCAPES ARE A BIT LARGER. THERE IS A
SUBTLE 700 MB WAVE RIGHT BEHIND THE BOUNDARY. THIS COULD BE THE
CATALYST TO SET OFF A FEW STORMS WITH THE SYSTEM, AS THE SURFACE
BASED POTENTIAL FOR THE FRONT DOESN`T APPEAR GREAT. WITH THIS IN
MIND, THUNDERSTORMS CHANCES WILL REMAIN IN THE ISOLATED CATEGORY AND
STRONG WIND GUSTS AND LIGHTNING APPEAR TO BE THE ONLY THREATS LATE
TONIGHT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 430 AM CDT WED AUG 15 2012
MODELS IN EXCELLENT AGREEMENT WITH A STRONG AND PROGRESSIVE
SHORTWAVE TROUGH MOVING INTO THE NORTHERN AND CENTRAL PLAINS ON
THURSDAY PUSHING A SIGNIFICANT COLD FRONT ACROSS THE REGION. THE
COLD FRONT IS FORECAST TO EXTEND FROM NORTHERN MISSOURI INTO EASTERN
KANSAS, NORTHERN OKLAHOMA, AND INTO THE WESTERN TEXAS PANHANDLE ON
THURSDAY MORNING THEN DROP SOUTH INTO THE SOUTHERN PLAINS DURING THE
AFTERNOON. A BROAD AREA OF COOLER HIGH PRESSURE IN ITS WAKE WILL
BRING A SIGNIFICANT COOL DOWN TO DAYTIME HIGHS INTO THE WEEKEND.
WILL CONTINUE WITH A 20 TO 30 POP ALONG THE COLD FRONT ON THURSDAY
MORNING MAINLY SOUTH OF A LINE FROM SAINT JOHN TO MEADE. SCATTERED
THUNDERSTORMS AND LIGHT SHOWERS MAY LINGER ACROSS THE SOUTHERN TIER
COUNTIES ALONG THE OKLAHOMA BORDER INTO THURSDAY NIGHT. NORTH WINDS
WILL GUST TO 30 MPH ON THURSDAY BEHIND THE COLD FRONT. A SECONDARY
VORT MAX ON THE BACK SIDE OF THE UPPER LOW COULD BRING IN ANOTHER
CHANCE FOR SHOWERS AND THUNDERSTORMS INTO FAR WESTERN KANSAS ON
FRIDAY THEN INTO MUCH OF SOUTHWEST AND SOUTH CENTRAL KANSAS ON
SATURDAY AND SATURDAY NIGHT. WILL MAINTAIN A 20 TO 30 POP FOR NOW.
THE LARGE UPPER TROUGH WILL THEN BEGIN TO MOVE EAST INTO THE EASTERN
CONUS FROM SUNDAY INTO EARLY NEXT WEEK WITH A WARMING TREND INTO THE
WESTERN HIGH PLAINS. THE MODELS SHOW ANOTHER CHANCE FOR
THUNDERSTORMS ON TUESDAY AS AN UPPER JET MOVES ACROSS THE PLAINS
ALONG WITH INCREASING LOW LEVEL MOISTURE AND WARM AIR ADVECTION.
OVERNIGHT LOWS WILL BE IN THE 50S FRIDAY AND SATURDAY MORNINGS THEN
SLOWLY WARMING INTO THE LOW TO MID 60S INTO EARLY NEXT WEEK. DAYTIME
HIGHS WILL WARM FROM AROUND 80 ON THURSDAY AND FRIDAY, THEN SLOWLY
WARM THROUGH THE MID TO UPPER 80S INTO MONDAY AND INTO THE LOWER 90S
BY TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1212 PM CDT WED AUG 15 2012
VFR CIGS EXPECTED THROUGH MUCH OF THE TAF PERIOD. THE BEST CHANCE FOR
CONVECTION WILL BE TOWARDS KHYS LATE TONIGHT IN WHERE CIGS MAY FLIRT
WITH MVFR IF CONVECTION MOVES OVER THE TERMINAL. FOR NOW WILL BRING
CB/VCTS FOR KHYS THIS EVENING. OTHERWISE, THE NEXT CONCERN IS A COLD
FRONT. THIS FRONT WILL MOVE THROUGH THE REGION EARLY TOMORROW MORNING
WITH N/NE WINDS INCREASING 20-25 KT WITH GUSTS TO 28-33 KT. THINK THAT
THE MODELS ARE UNDOING WINDS AND HAVE GONE HIGHER THAN GUIDANCE DUE
TO 30-40 KT 850 HPA WINDS AND A ISALLOBARIC RESPONSE RIGHT ALONG
THE BOUNDARY.
&&
.FIRE WEATHER...
ISSUED AT 430 AM CDT WED AUG 15 2012
WINDS WILL BE LIGHT BUT GUSTING TO AROUND 20 KNOTS IN THE AFTERNOON
FROM THE SOUTHEAST. WARM TEMPERATURES AND DRY AIR WILL
DRIVE RELATIVE HUMIDITIES DOWN INTO THE 20 TO 30 PERCENT RANGE DURING
BETWEEN 3 AND 7 PM. A COLD FRONT WILL ENTER THE AREA THIS EVENING,
EFFECTIVELY TURNING WINDS TO THE NORTH THROUGH THE NIGHT, WITH
STRONGER NORTH WINDS EXPECTED BY THURSDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 97 66 81 53 / 0 40 10 10
GCK 98 64 80 53 / 10 20 10 10
EHA 97 64 81 55 / 10 30 20 20
LBL 98 66 83 54 / 0 30 20 20
HYS 97 65 79 53 / 10 20 10 10
P28 96 70 85 59 / 0 30 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...RUSSELL
LONG TERM...KRUSE
AVIATION...SUGDEN
FIRE WEATHER...RUSSELL
AREA FORECAST DISCUSSION
NWS CARIBOU ME
115 PM EDT WED AUG 15 2012
.SYNOPSIS...
A TROUGH OF LOW PRESSURE WILL APPROACH FROM THE WEST TODAY AND
TONIGHT. LOW PRESSURE WILL CROSS THE GULF OF MAINE THURSDAY. A
COLD FRONT WILL APPROACH LATER FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1 PM UPDATE...CONTINUED TO ADJUST POPS/WX FOR CURRENT RADAR
TRENDS. SHOWERS AND THUNDERSTORMS BECOMING NUMEROUS TO WIDESPREAD
AS THE ATMOSPHERE DESTABILIZES AND REGION OF INCREASED POSITIVE VORT
MOVES OVERHEAD.
930 AM UPDATE...MADE ADJUSTMENTS TO LOWER POPS THIS MORNING AS
SHOWERS WITH NEXT SYSTEM ARE STILL WELL TO OUR WEST. HOWEVER...I
DID INCREASE POPS TO CATEGORICAL ACROSS THE NORTHWEST THIS
AFTERNOON AS LATEST MODEL AND THE HRRR SUPPORT THIS.
PREVIOUS DISCUSSION...
A TROUGH OF LOW PRESSURE APPROACHING FROM THE WEST WILL
BRING INCREASING CHANCES FOR SHOWERS ACROSS THE AREA TODAY. A
SHORTWAVE EMBEDDED IN THE TROUGH IS MOVING INTO WESTERN NEW
ENGLAND EARLY THIS MORNING AND WILL LIFT INTO WESTERN MAINE DURING
THE MIDDAY TODAY AND THEN MOVE THROUGH NORTHERN AND EASTERN MAINE
LATER THIS AFTERNOON. THIS SHORTWAVE WILL PROVIDE FOCUS FOR
SHOWERS AND SOME EMBEDDED THUNDERSTORMS. CAPES ON BOTH THE GFS AND
NAM ARE BETWEEN 600 AND 700 J/KG THIS AFTERNOON AND PRECIPITABLE
QPF IS AROUND 1.5 INCHES. WITH TALL...THIN CAPES AND SATURATED AIR
ANY THUNDERSTORMS TODAY COULD PRODUCE HEAVY DOWNPOURS. THE MAIN
TROUGH AXES WILL MOVE INTO THE REGION LATER TONIGHT BRINGING
ANOTHER AREA OF CONCENTRATED SHOWERS AND PERHAPS AN AREA OF
STEADIER RAIN LATER TONIGHT ESPECIALLY IN WESTERN AREAS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
LOW PRESSURE CROSSING THE GULF OF MAINE WILL BRING RAIN TO THE
REGION THURSDAY. THE LOW WILL MOVE EAST THURSDAY NIGHT ALLOWING
THE RAIN TO TAPER TO SHOWERS. A COLD FRONT WILL THEN APPROACH
FRIDAY WITH A CHANCE OF SHOWERS/THUNDERSTORMS IN ADVANCE OF THE
FRONT. THE FRONT BEGINS TO SLOWLY CROSS THE REGION FRIDAY NIGHT
WITH A CHANCE OF SHOWERS/THUNDERSTORMS. TEMPERATURES WILL BE AT
BELOW NORMAL LEVELS THURSDAY...WITH NEAR NORMAL LEVEL TEMPERATURES
FRIDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
UNCERTAINTY STILL EXISTS REGARDING HOW QUICKLY THE FRONT CROSSES
THE REGION SATURDAY THROUGH SUNDAY. A MORE RAPID MOVEMENT WOULD
KEEP A CHANCE OF SHOWERS ACROSS THE REGION SATURDAY WITH THE
FRONT...WITH THE FRONT THEN MOVING EAST SUNDAY ALLOWING FOR
IMPROVING CONDITIONS. A SLOWER FRONTAL MOVEMENT COULD KEEP THE
FRONT ACROSS THE REGION THROUGH SUNDAY WITH LOW PRESSURE POSSIBLY
LIFTING NORTH ALONG THE FRONT. THE SLOWER SCENARIO WOULD KEEP
UNSETTLED CONDITIONS ACROSS THE REGION THROUGH THE WEEKEND. HAVE
BASED THE FORECAST ON A SLOWER SOLUTION...WHICH MOVES THE SYSTEM
SLOWLY EAST MONDAY. COULD STILL HAVE A CHANCE OF SHOWERS ACROSS
THE REGION MONDAY. A COLD FRONT COULD THEN APPROACH TUESDAY WITH A
CHANCE OF SHOWERS/THUNDERSTORMS. TEMPERATURES SHOULD REMAIN AT
SLIGHTLY BELOW NORMAL LEVELS SATURDAY THROUGH TUESDAY.
&&
.AVIATION /17Z WEDNESDAY THROUGH SUNDAY/...
NEAR TERM: GENERALLY VFR CONDITIONS ARE EXPECTED TODAY INTO EARLY
TONIGHT THOUGH CONDITIONS MAY BRIEFLY LOWER TO MVFR OR IFR IN
HEAVIER SHOWERS. CONDITIONS MAY LOCALLY DROP TO IFR LATE TONIGHT
IN PATCHY FOG.
SHORT TERM: CONDITIONS THURSDAY ARE EXPECTED TO GENERALLY RANGE
FROM MVFR TO IFR LEVELS...WITH OCCASIONAL LIFR CONDITIONS. OCCASIONAL
MVFR CONDITIONS WILL REMAIN POSSIBLE THURSDAY NIGHT. GENERALLY VFR
CONDITIONS ARE EXPECTED FRIDAY THROUGH SATURDAY...THOUGH
OCCASIONAL MVFR CONDITIONS COULD OCCUR WITH ANY SHOWERS OR
THUNDERSTORMS. CONDITIONS SUNDAY WILL BE DEPENDENT ON HOW QUICKLY
THE FRONT MOVES EAST OF THE REGION. HOWEVER...EXPECT OCCASIONAL
MVFR CONDITIONS COULD REMAIN POSSIBLE WITH SHOWERS.
&&
.MARINE...
NEAR TERM: WINDS AND SEAS WILL REMAIN BELOW SCA TODAY AND
TONIGHT. SOME FOG MAY MOVE OVER THE WATERS LATER TONIGHT.
SHORT TERM: WINDS/SEAS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT
ADVISORY LEVELS THURSDAY THROUGH SUNDAY. VISIBILITIES WILL BE
REDUCED IN RAIN AND FOG THURSDAY INTO THURSDAY NIGHT. OCCASIONAL
SHOWERS ARE THEN POSSIBLE LATER FRIDAY THROUGH THE WEEKEND.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...BLOOMER/RUNYAN
SHORT TERM...NORCROSS
LONG TERM...NORCROSS
AVIATION...BLOOMER/RUNYAN
MARINE...BLOOMER/RUNYAN/NORCROSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
426 PM EDT WED AUG 15 2012
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 425 PM EDT WED AUG 15 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A POSITIVE TILT MID/UPPER
LEVEL TROUGH FROM NRN MANITOBA INTO ERN MT WITH A DOWNSTREAM RIDGE
FROM THE WRN GREAT LAKES INTO NRN ONTARIO. AT THE SFC...A COLD FRONT
EXTENDED THROUGH THE ERN DAKOTAS FROM LOW PRES OVER SE MANITOBA.
LIGHT SHOWERS OVER WRN WI THAT HAD DEVELOPED WITH WAA/305-310K
ISENTROPIC LIFT HAD DISSIPATED AS THEY MOVED INTO DRIER AIR TO THE
EAST...LEAVING MAINLY JUST BKN MID CLOUDS UPSTREAM OVER NW WI. SCT
SHRA/TSRA HAD ALSO DEVELOPED AHEAD OF THE FRONT OVER NW MN.
TONIGHT AND THURSDAY...EVEN THOUGH THE NAM/RUC SEEM OVERDONE WITH
THE AMOUNT OF WAA PCPN INTO THE AREA LATE THIS AFTERNOON AND
EVENING...COMPARED TO CURRENT TRENDS...CANNOT RULE OUT SOME LIGHT
SHOWERS DEVELOPING OVER THE WEST THIS EVENING WHERE SLIGHT CHANCE
POPS WERE RETAINED. OTHERWISE...MORE WIDESPREAD PCPN SHOULD MOVE
INTO THE CWA...MAINLY AFT 06Z AS THE MODELS HAVE TRENDED TOWARD A
SLOWER ARRIVAL OF GREATEST SHRA/TSRA CHANCES. FAVORABLE DYNAMICS
WITH 700-300 MB QVECTOR CONV AHEAD OF THE MID LEVEL TROUGH AND LOW
LEVEL CONV WITH THE FRONT SHOULD SUPPORT CATEGORICAL POPS LATE
TONIGHT INTO THURSDAY MORNING. THE SHRA/TSRA SHOULD EXIT CNTRL UPPER
MI IN THE MORNING AND THE ERN CWA DURING THE EARLY AFTERNOON. THERE
IS LESS CONFIDENCE WITH POTENTIAL FOR HIGHER PCPN AMOUNTS OR SEVERE
WEATHER AS THE GREATER MOISTURE INFLOW AND INSTABILITY WILL REMAIN
FARTHER SOUTH OVER WI.
STRENGTHENING WIND FIELDS WITH 0-6KM SHEAR VALUES INTO THE 30-35 KT
ARE EXPECTED AS THE SHRA/TSRA ARRIVES BUT MAY LAG THE BEST LOW LEVEL
FORCING. NEVERTHELESS THERE IS LIMITED SVR POTENTIAL WITH MUCAPE
VALUES FCST INTO THE 500-1000 J/KG RANGE. IF STRONGER LINEAR
CONVECTIVE AREAS SURVIVE AS THEY MOVE OUT OF MN AND NW WI...SOME
DAMAGING WIND GUSTS MAY BE POSSIBLE AS THE MAIN HAZARD...PER SPC.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 425 PM EDT WED AUG 15 2012
TEMPERATURES THROUGH THE EXTENDED WILL REMAIN BELOW NORMAL WITH A
WARMING TREND BEGINNING LATE IN THE PERIOD.
THURSDAY NIGHT THROUGH FRIDAY NIGHT...THE UPPER LEVEL AND SURFACE
LOW WILL BECOME VERTICALLY STACKED THURSDAY NIGHT INTO FRIDAY AS THE
LOW SHIFTS FROM CENTRAL ONTARIO NORTH AND EASTWARD TO JAMES BAY. AS
THIS HAPPENS THE UPPER LEVEL TROUGH AXIS WILL SWING ACROSS UPPER
MICHIGAN. THE COOLER AIR ALOFT ASSOCIATED WITH THIS TROUGH WILL HELP
TO CREATE CONDITIONS FAVORABLE FOR LAKE EFFECT RAIN SHOWERS ACROSS
MAINLY CENTRAL PORTIONS OF UPPER MICHIGAN. H850 TEMPS ARE PROGGED TO
BE AROUND 4 TO 6C WITH SURFACE TEMPS AROUND 18 TO 19C ACROSS THE
AREA...WHICH SHOULD CREATE A LARGE ENOUGH TEMPERATURE DIFFERENCE TO
CAUSE THE LAKE EFFECT RAIN SHOWERS TO FORM. ALONG WITH THE RAIN
SHOWERS...HIGH WINDS ARE ALSO POSSIBLE OVER THE LAKE THURSDAY
AFTERNOON INTO THURSDAY NIGHT AS 30 TO 35 KNOT WINDS...AS SHOWN BY
THE EC/GFS...MIX DOWN TO THE LAKE SURFACE. AS THE UPPER LEVEL LOW
SHIFTS NORTHEASTWARD AND THE UPPER LEVEL TROUGH AXIS SHIFTS PAST THE
UPPER PENINSULA FRIDAY NIGHT...H850 TEMPS ARE EXPECTED TO
WARM...EFFECTIVELY REDUCING THE LAKE EFFECT RAIN SHOWER CHANCES. A
COOL NIGHT IS IN STORE FOR FRIDAY NIGHT AS WINDS BECOME LIGHT AND
SKIES BECOME MOSTLY CLEAR. TEMPERATURES AREA EXPECTED TO BE IN THE
LOW TO MID 40S ACROSS MAINLY INLAND AREAS...WITH A FEW OF THE USUAL
COOL SPOTS POTENTIALLY FALLING INTO THE UPPER 30S.
SATURDAY THROUGH MONDAY...A WEAK COLD FRONT WILL PUSH SOUTHWARD INTO
THE U.P. SATURDAY AFTERNOON THROUGH SUNDAY. A 500MB SHORTWAVE IS
ALSO PROGGED TO MOVE THROUGH THE AREA SATURDAY NIGHT THROUGH
MONDAY...AS IT ROTATES AROUND THE LOW CENTERED OVER JAMES BAY. THIS
SHOULD PROVIDE ENOUGH FORCING FOR A FEW SHOWERS TO DEVELOP THROUGH
THIS TIME PERIOD...HOWEVER...MOISTURE SHOULD BE FAIRLY LIMITED AS A
SURFACE HIGH PRESSURE SYSTEM WILL REMAIN CENTERED TO THE SOUTH
SOUTHWEST OF THE AREA KEEPING DRIER AIR ADVECTING INTO THE AREA FROM
THE WEST.
MONDAY NIGHT THROUGH WEDNESDAY...AS THE UPPER LEVEL LOW BEGINS TO
DRIFT SLOWLY EASTWARD...A RIDGE BUILDING OVER MUCH OF THE PLAINS
STATES WILL BEGIN TO WEAKEN AS IT TRIES TO BUILD EASTWARD INTO THE
UPPER GREAT LAKES REGION. THIS SHOULD ALLOW TEMPERATURES TO INCREASE
TO NEAR NORMAL LEVELS BY TUESDAY AND INTO THE DAY WEDNESDAY. TUESDAY
NIGHT INTO WEDNESDAY BOTH THE GFS/EC HAVE A SHORTWAVE ROTATING
AROUND THE RIDGE ALONG WITH A SURFACE LOW JUST TO THE WEST OF THE
REGION...BRINGING THE NEXT CHANCE OF SHOWERS TO THE AREA.
HOWEVER...WITH CONSIDERABLE DIFFERENCES IN SURFACE LOW PLACEMENT AND
STRENGTH HAVE DECIDED TO STICK TO A CONSENSUS OF THE MODELS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 140 PM EDT WED AUG 15 2012
VFR CONDITIONS ARE EXPECTED THIS AFTERNOON THROUGH THIS EVENING.
SOME LIGHT SHOWERS MAY DEVELOP AT IWD BUT SHOULD NOT RESTRICT VSBY
OR DROP CIGS INTO MVFR RANGE. A MID LEVEL TROUGH AND COLD FRONT
APPROACHING THE AREA WILL GENERATE AN AREA OF SHRA/TSRA THIS
EVENING OVER MN. EXPECT THE CONVECTION TO MOVE INTO UPPER MI AFT
06Z. EVEN THOUGH IT SHOULD WEAKEN GUSTY WINDS WILL BE POSSIBLE
OVERNIGHT AT IWD/CMX WITH ANY TSRA. THE PCPN SHOULD EXIT SAW DURING
THE MORNING LEAVING MAINLY MVFR CIGS OVER THE CWA AS COLD AIR MOVES
IN ALONG WITH GUSTY WNW WINDS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 425 PM EDT WED AUG 15 2012
AS A COLD FRONT MOVES THROUGH LAKE SUPERIOR...EXPECT A SHARP WIND
SHIFT TO THE W LATE TONIGHT AND THU FOLLOWING THIS FRONTAL PASSAGE.
THE ARRIVAL OF MUCH COOLER AIR IN THE WAKE OF THE FRONT OVER THE
WARM WATERS OF LAKE SUPERIOR WILL ALSO RESULT IN ENHANCED MIXING
OVER THE LAKE WITH W-NW WINDS UP TO 30 KTS AND POSSIBLE GALES TO 35
KNOTS OVER THE N CNTRL PORTION OF THE LAKE...FROM LATE THURSDAY
AFTERNOON THROUGH THURSDAY NIGHT WHERE A GALE WATCH WAS POSTED.
SINCE MODELS HAVE TRENDED STRONGER WITH THE LOW LEVEL WIND FIELDS
THERE IS ALSO THE POTENTIAL FOR THE WATCH TO BE EXPANDED AND OR A
WARNING ISSUED FOR A LARGER AREA OF THE LAKE. EXPECT THE STRONGER NW
WINDS TO SLOWLY SUBSIDE ON FRI THRU THE WEEKEND AS THE PRES GRADIENT
WEAKENS WITH BROAD HIGH PRESSURE SETTLING OVER THE REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM THURSDAY AFTERNOON THROUGH LATE THURSDAY NIGHT
FOR LSZ264-266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KEC
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS DULUTH MN
307 PM CDT WED AUG 15 2012
.SHORT TERM...[NOW - THURSDAY NIGHT]
AT 20Z...THERE WAS A POTENT SHORTWAVE IN EASTERN MONTANA AND
WESTERN NORTH DAKOTA APPROACHING THE NORTHERN PLAINS...AND AN
ASSOCIATED MID/UPPER LEVEL TROUGH EXTENDING INTO CENTRAL CANADA.
AN ASSOCIATED SURFACE LOW WAS IN SOUTHEASTERN MANITOBA. A 70 TO 80
KNOT JET WAS ROUNDING THE BASE OF THE MID/UPPER LEVEL TROUGH. A
STRONG COLD FRONT IN ASSOCIATION WITH THE SURFACE LOW STRETCHED
FROM SOUTHEASTERN MANITOBA...THROUGH NORTHWESTERN MINNESOTA...AND
THROUGH EASTERN SOUTH DAKOTA. THE FA HAD SLIGHTLY GUSTY SOUTHERLY
WINDS. TEMPERATURES WERE IN THE MID TO UPPER 70S. DEW POINT
TEMPERATURES WERE STILL IN THE 50S ACROSS MUCH OF THE EASTERN
FA...BUT THEY WERE CLIMBING INTO THE LOW TO MID 60S ACROSS THE
WESTERN FA WITH THE INFLUX OF MOISTURE AHEAD OF THE APPROACHING
COLD FRONT. THERE WERE SHOWERS AND SOME STORMS STRETCHING FROM
SOUTHWESTERN ONTARIO...THROUGH NORTHWESTERN MINNESOTA...AND INTO
EAST CENTRAL NORTH DAKOTA.
THROUGH THIS EVENING...THE COLD FRONT IN WESTERN MINNESOTA IS
EXPECTED TO SWEEP ACROSS THE NORTHLAND LATE THIS AFTERNOON AND
THIS EVENING...AND ITS PASSAGE WILL LIKELY MEAN SHOWERS AND
THUNDERSTORMS FOR MUCH OF THE FA. THE MODELS CONTINUE TO BE IN
REASONABLE AGREEMENT WITH TIMING AND PCPN. THE INFLUX OF WARM
SOUTHERLY FLOW AHEAD OF THE FRONT...COUPLED WITH THE EXPECTED
SHEAR AND CAPE...COULD RESULT IN SOME SEVERE THUNDERSTORMS.
CONTINUE TO THINK THAT MORE DISCREET SHOWERS AND STORMS IN WESTERN
MINNESOTA THIS AFTERNOON WILL BEGIN TO MOVE INTO NORTHEASTERN
MINNESOTA LATE THIS AFTERNOON AND TAKE ON A MORE LINEAR STRUCTURE.
THIS IS BACKED UP BY RECENT RUNS OF THE WRF AND HRRR MODELS. THIS
WOULD SUGGEST THAT DAMAGING WINDS ARE THE GREATEST THREAT FOR THE
STORMS TONIGHT...AND THAT IS IN AGREEMENT WITH THE SLIGHT RISK OF
SEVERE WEATHER CURRENTLY OUT FROM THE STORM PREDICTION CENTER AND
ITS EMPHASIS ON DAMAGING WINDS. LARGE HAIL AND BRIEF DOWNPOURS OF
RAIN ARE BOTH CERTAINLY POSSIBLE TOO. MIXED LAYER CAPE VALUES OF
1000 TO 2000 J/KG...DEEP LAYER SHEAR OF 30 TO 50 KNOTS...AND
PRECIPITABLE WATER VALUES OF AROUND 1.5 INCHES ARE EXPECTED THIS
AFTERNOON WHEN THE COLD FRONT MOVES INTO THE WESTERN FA. SINCE
THIS COLD FRONT WILL BE MOVING FAIRLY QUICKLY...HEAVY RAIN IS NOT
TOO MUCH OF AN ISSUE DUE TO LACK OF THUNDERSTORMS RESIDENCE TIME
OR TRAINING. HOWEVER...THERE COULD CERTAINLY BE BRIEF DOWNPOURS
WITH THE RAIN. MUCH OF THE FA HAS BEEN GIVEN ABOUT A QUARTER TO
HALF INCH OF RAIN FOR THE FORECAST THROUGH THIS EVENING.
LATE TONIGHT...MUCH COOLER AIR WILL SWOOP INTO THE NORTHLAND LATE
TONIGHT IN THE WAKE OF THE FRONT. ANY REMAINING PCPN SHOULD
TRANSITION TO SHOWERS...BUT THERE MAY BE SOME LINGERING THUNDER
ACROSS THE FAR EASTERN FA.
THURSDAY...IT LOOKS LIKE A SOMEWHAT DREARY SUMMER DAY ACROSS THE
NORTHLAND. PARTLY TO MOSTLY CLOUDY SKIES...GUSTY NORTHWEST
WINDS...AND MUCH COOLER TEMPERATURES ARE EXPECTED IN THE WAKE OF
THE FRONT. MODEL SOUNDINGS SUGGEST WIND GUSTS OF 20 TO 30 MPH AT
TIMES. SHOWERS ARE POSSIBLE ACROSS NORTHERN MINNESOTA. THERE MAY
BE SOME LATE DAY SUNSHINE ACROSS THE WESTERN FA.
THURSDAY NIGHT...THE CLOUDS SHOULD GRADUALLY CLEAR AND THE WINDS
RELAX AS HIGH PRESSURE MOVES INTO THE NORTH CENTRAL US.
.LONG TERM...[FRIDAY - TUESDAY]
PATTERN CHANGE TO A STRONGER UPPER LEVEL TROF ANCHORED OVER THE
CENTRAL GREAT LAKES THIS WEEKEND AND EARLY NEXT WEEK WILL LEAVE
THE DULUTH CWA UNDERNEATH COOL NW FLOW ALOFT AND WHAT WILL
PROBABLY FEEL LIKE EARLY FALL WEATHER AT TIMES. AS IS COMMON IN
PREVAILING NW FLOW ALOFT..A SERIES OF WEAK BUT AMPLIFYING
DISTURBANCES WILL DIVE SOUTHEASTWARD ACROSS OUR AREA INTO THE MAIN
TROF AXIS DURING THE SAT-MON TIME FRAME. RELATIVELY COOL TEMPS
ALOFT AND STEEP LOW-MID LEVEL LAPSE RATES WITH ANY DAYTIME SUN
SHOULD RESULT IN ISOLATED/SCATTERED SHOWERS AND PERHAPS A FEW
T-STORMS EACH DAY FRIDAY THRU SUNDAY. MODELS TYPICALLY HAVE A HARD
TIME RESOLVING INDIVIDUAL DISTURBANCES IN THIS FLOW REGIME BEYOND
48-60 HOURS..AND THIS SEEMS TO BE THE CASE THRU MONDAY AS THE WAVE
THAT SEEMS BEST RESOLVED RIGHT NOW TIMING/PLACEMENT WISE IS ON
FRIDAY.
EARLY NEXT WEEK LOOKS FAIRLY TRANQUIL WITH A SLOW WARMING TREND OF
A FEW DEGREES EACH DAY AS GREAT LAKES TROF SLOWLY DE-AMPLIFIES
AND FLOW ALOFT BECOMES MORE WESTERLY. THIS SHOULD EVENTUALLY ALLOW
MOISTURE TO SLOWLY INCREASE BY THE END OF THE 7 DAY FORECAST
PERIOD..WITH AT LEAST SMALL CHANCES FOR SHOWERS/TSTORMS RETURNING
FROM WED/THUR.
&&
.AVIATION...18Z TAFS
THERE ARE FEW SUBSTANTIAL CHANGES TO THE TIMING AND REASONING FROM
THE PREVIOUS TAF ISSUANCE. SCATTERED-BROKEN MID LEVEL
ALTOCUMULUS DECK WILL CONTINUE TO MIGRATE NORTHEAST ACROSS MOST
TAF SITES THIS AFTERNOON AS WARM FRONT FROM KBRD-KHYR CONTINUES TO
PUSH NORTHWARD. SCATTERED 030-040 CUMULUS ALSO EXPECTED TO DEVELOP
18-21Z AT ALL TAF SITES. STRONG COLD FRONT OVER THE EASTERN
DAKOTAS WILL PUSH EASTWARD ACROSS ALL TAF SITES THIS
EVENING/OVERNIGHT WITH A 2-4 HOUR PERIOD OF THUNDERSTORMS. SOME
STRONG WIND GUSTS AND HAIL ARE POSSIBLE WITH THUNDERSTORMS THIS
EVENING. WINDS WILL SHIFT TO THE NORTHWEST LATE EVENING AND
OVERNIGHT BEHIND THE FRONT..WITH BROKEN MVRF CEILINGS LIKELY
PERSISTING ALONG/NORTH OF HIGHWAY 2 CORRIDOR THRU 12Z THURSDAY
MORNING.
&&
.POINT TEMPS/POPS...
DLH 54 63 45 70 / 70 10 0 30
INL 51 61 41 69 / 70 30 10 30
BRD 54 66 45 71 / 70 10 0 10
HYR 57 68 44 70 / 60 10 0 20
ASX 59 68 47 69 / 60 10 10 30
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...GROCHOCINSKI
LONG TERM....MILLER
AVIATION...MILLER
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
542 PM CDT WED AUG 15 2012
.SHORT TERM...
ISSUED AT 137 PM CDT WED AUG 15 2012
(TONIGHT)
MAIN CONCERN DEALS WITH RAIN CHANCES THROUGH TONIGHT. PREFER THE
NAM`S DEPICTION OF MASS FIELDS AND QPF THROUGH 12Z AS IT HAS BETTER
CONTINUITY AND THE GFS IS SHOWING QUITE A BIT OF CONVECTIVE FEEDBACK
DEVELOPING BETWEEN 00-06Z. STILL EXPECT TO BE MAINLY DRY THROUGH
06Z AS SHORTWAVE RIDGING WILL STILL BE WORKING INTO THE AREA.
THEREAFTER...THERE WILL BE INCREASED 925-850MB MOISTURE CONVERGENCE
ON THE NOSE OF A 40KT LOW LEVEL JET. HAVE KEPT SLIGHT CHANCES AFTER
06Z...MAINLY OVER CENTRAL AND NORTHEAST MISSOURI INTO WEST CENTRAL
ILLINOIS. FORECAST SOUNDINGS DO SHOW THAT THERE WILL STILL A BIT OF
CINH EVEN ALOFT WHICH WILL LIMIT OVERALL COVERAGE OF -TSRA/-SHRA. I
DID INCREASE TO LOW CHANCE POPS OVER THE FAR NORTHERN CWA BETWEEN
09-12Z AS THIS AREA BEGINS TO SEE AN INCREASE IN LARGE SCALE ASCENT
AHEAD OF SHORTWAVE TROUGH. GOING LOWS ARE A GOOD COMPROMISE OF THE
NAM/GFS MOS TEMPS...SO LEFT PRETTY MUCH AS IS.
BRITT
&&
.LONG TERM...
ISSUED AT 137 PM CDT WED AUG 15 2012
(TOMORROW THROUGH NEXT TUESDAY)
THE PRIMARY FCST PROBLEM FOR TOMORROW AND TOMORROW NIGHT IS PCPN
CHCS AND SVR WX POTENTIAL. VORT MAX LOCATED OVER MT AND ALBERTA AT
12Z WED WILL DEEPEN AS IT MOVES ALONG THE US/CANADIAN BORDER TODAY.
ASSOCIATED SFC LOW SHOULD BE LOCATED IN WRN ONT AT 12Z THU WITH A
CDFNT EXTENDING SWWD THROUGH WI INTO IA/MO/KS. MODELS CONTINUE TO
SHOW FAVORABLE TIMING FOR WIDESPREAD TSRA WITH AFTN FROPA HOWEVER
OUTFLOW BDRYS FROM OVERNIGHT CONVECTION FARTHER NORTH MIGHT PUSH THE
EFFECTIVE BDRY FARTHER SOUTH THAN INITIALLY ANTICIPATED. NEXT
QUESTION IS SVR WX POTENTIAL. UNFAVORABLE FACTORS INCLUDE LIMITED
DYNAMICS THIS FAR SOUTH OF THE UPPER VORT MAX...0-6 KM SHEAR FCSTS
OF LTE 20 KTS SOUTH OF THE CDFNT...AND A LAG OF SEVERAL HOURS
BETWEEN SFC FROPA AND UPPER LEVEL FORCING FOR ASCENT.
HOWEVER...STRONG SFC CONVERGENCE ALONG THE CDFNT AND 1500-2000 J/KG
OF CAPE EXPECTED AHEAD OF THE FRONT SHOULD PARTIALLY COMPENSATE FOR
THE LOWER SHEAR VALUES AND LIMITED DYNAMICS. ATTM IT LOOKS LIKE THE
PRIMARY THREAT WILL BE DAMAGING WIND GUSTS DUE TO THE STEEP LOW LEVEL
LAPSE RATES /ESPECIALLY ACROSS THE SERN HALF OF THE CWA/ ALTHOUGH
HAIL WILL ALSO BE POSSIBLE WITH THE STRONGER UPDRAFTS.
COOLER WX EXPECTED FOR FRI THROUGH SUN AS A SFC HIGH PRESSURE
CENTER BUILDS IN BEHIND THE FRONT WITH THE RIDGE AXIS OVERHEAD BY
12Z SAT. GOOD RADIATIONAL COOLING CONDITIONS WITHIN A DRIER POSTFNTL
AIR MASS ON FRI NIGHT SHOULD PRODUCE OVERNIGHT LOWS IN THE 50S
ACROSS THE CWA. H85 TEMPERATURES OF 10-12 DEG C SUPPORT HIGHS IN THE
MID 70S TO LOWER 80S ON SAT/SUN. A VORT LOBE ROTATING AROUND THE ERN
CONUS LONGWAVE TROF SHOULD MOVE THROUGH MO/IL ON SAT AFTN/EVE
LEADING TO INCREASED CLOUDINESS AND POSSIBLY PCPN DEPENDING ON
TIMING AND MOISTURE AVAILABILITY. MAINTAINED A DRY FCST FOR NOW
GIVEN TIMING UNCERTAINTY. MODELS AGREE THAT THE CWA WILL BE UNDER NW
FLOW ALOFT THROUGH SUN NIGHT BUT SOLUTIONS BEGIN TO DIVERGE AFTER
MON. GENERALLY EXPECT A WARMING TREND BY LATE NEXT WEEK AS THE DEEP
TROF OVER THE ERN CONUS LIFTS AND A RIDGE OVER THE WRN CONUS SHIFTS
EWD.
KANOFSKY
&&
.AVIATION...
ISSUED AT 532 PM CDT WED AUG 15 2012
VFR CONDITIONS THIS EVENING WITH MOSTLY CLEAR SKIES AND SOUTHERLY
WINDS UP TO 10KTS. CONVECTION EXPECTED TO DEVELOP TO THE NORTHWEST
ALONG AN APPROACHING COLD FRONT. MANY QUESTIONS SURROUND HOW
THESE THUNDERSTORMS WILL IMPACT OUR REGION LATE TONIGHT AND EARLY
THURSDAY MORNING. LATEST NAM AND 4KM NCEP WRF SHOW CONVECTION AND
OUTFLOW BOUNDARY REACHING ALL TERMINALS BY 12Z THURSDAY MORNING.
THINK THIS MAY BE A BIT TOO AGRESSIVE...AND HAVE ONLY ADJUSTED THE
FORECAST FOR KUIN AT THIS TIME TO ACCOUNT FOR THIS SCENARIO.
HOPEFULLY LATER HRRR RUNS AND 00Z NAM RUN LEND CONFIDENCE TO
CONVECTIVE TRENDS. FOR NOW STILL THINK BEST CHANCE OF
THUNDERSTORMS AT KCOU AND ST. LOUIS METRO TAFS WILL BE WITH COLD
FRONTAL PASSAGE DURING THE AFTERNOON.
SPECIFICS FOR KSTL...
VFR CONDITIONS MUCH OF THE NIGHT...WITH HIGH/MID CLOUD FROM
APPROACHING CONVECTION OVERSPREADING THE TERMINAL BY DAYBREAK.
STILL BELIEVE BEST CHANCE OF THUNDERSTORMS WILL BE IN THE
AFTERNOON WITH COLD FRONT...BUT CANT RULE OUT THE SCENARIO THAT
NOCTURNAL CONVECTION/OUTFLOW MAKES IT TO THE TERMINAL AROUND 12Z.
CVKING
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1258 PM CDT WED AUG 15 2012
.UPDATE...MORNING UPPER AIR ANALYSIS INDICATES UPPER LEVEL RIDGING
OVER THE SOUTHWESTERN CONUS...TROUGHING OVER THE EAST...AND A MID
LEVEL SHORT WAVE OVER SOUTH-CENTRAL CANADA AND THE NORTHERN
PLAINS. UPPER LEVEL JET ENERGY IS ALSO NOTED MEANDERING NORTH AND
SOUTH FROM SOUTHWESTERN AND SOUTHERN CANADA...AS WELL AS THE
NORTHERN PLAINS ON INTO THE EASTERN CONUS...AND A ~50KT MID LEVEL
JET STREAK IS NOTED ON THE SOUTH/SOUTHEAST SIDE OF THE APPROACHING
MID LEVEL SHORT WAVE. WATER VAPOR IMAGERY INDICATES A DEVELOPING
TROPICAL TAP OVER THE SOUTHWESTERN CONUS...BUT THIS MOISTURE
REMAINS RELEGATED TO OUR SOUTHWEST WITH MID LEVEL MOISTURE OVER
OUR AREA PRIMARILY BEING PULLED IN FROM THE PACIFIC NORTHWEST BY
THE APPROACHING MID LEVEL SHORT WAVE. AT THE SURFACE AN AREA OF
LOW PRESSURE IS NOTED OVER WESTERN NEBRASKA...WITH AN ASSOCIATED
COLD FRONT EXTENDING SOUTH/SOUTHWEST FROM THE LOW ACROSS WESTERN
NEBRASKA AND NORTHEASTERN COLORADO. LOW LEVEL FLOW REMAINS FROM
THE SOUTH ACROSS MUCH OF THE CENTRAL PLAINS AS A RESULT...WITH THE
LOW LEVEL WIND FIELD TURNING MORE NORTHWESTERLY ACROSS THE CENTRAL
HIGH PLAINS BEHIND THE LOW LEVEL BAROCLINIC ZONE. VISIBLE
SATELLITE IMAGERY INDICATES VERY LITTLE IN THE WAY OF CLOUD COVER
ACROSS NEBRASKA...BUT HIGH LEVEL CLOUDS AHEAD OF THE MID LEVEL
SHORT ARE BEGINNING TO ENTER THE STATE FROM SOUTH DAKOTA. SMOKE IS
ALSO EVIDENT ON VISIBILITY SATELLITE IMAGERY...ORIGINATING FROM
THE WILDFIRES CURRENTLY BURNING ACROSS WESTERN PORTIONS OF THE
CONUS.
SHORT TERM GUIDANCE CONTINUES TO SUGGEST THE APPROACHING MID LEVEL
SHORT WAVE WILL CONTINUE MOVING EAST/SOUTHEAST ACROSS THE NORTHERN
PLAINS TONIGHT INTO TOMORROW. THIS WILL ALLOW THE SURFACE
LOW...CURRENTLY OVER WESTERN NEBRASKA...TO PUSH EAST THUS ALLOWING
THE LOW LEVEL BAROCLINIC ZONE TO ALSO SWEEP EAST ACROSS OUR CWA.
QPF FIELDS FROM THE 15/12Z NAM AND 4KM WRF-NMM...AS WELL AS THE
15/14Z HRRR SUGGEST CONVECTION WILL INITIATE ACROSS OUR
WEST/NORTHWESTERN CWA ALONG THE LOW LEVEL BAROCLINIC ZONE AROUND
00Z. ISOLATED TO PERHAPS SCATTERED PRECIPITATION IS THEN EXPECTED
TO PUSH EAST/SOUTHEAST ACROSS THE CWA...WITH NORTHERN PORTIONS OF
OUR CWA MOST FAVORED FOR PRECIPITATION BETWEEN 00Z AND 03Z. GIVEN
ALL THIS...WENT AHEAD WITH 20% POPS ACROSS OUR FAR WEST/NORTHWEST
21Z-00Z...WITH 40%-50% POPS SPREADING ACROSS MUCH OF THE REST OF
THE CWA 00Z-06Z. THE 15/12Z NAM SUGGESTS 0-1KM MLCAPE VALUES OF
~1500J/KG WILL BE IN EXISTENCE ACROSS MUCH OF THE CWA THIS
AFTERNOON AND EVENING...WITH DEEP LAYER BULK SHEAR VALUES OF
20-30KTS ALSO IN EXISTENCE. GIVEN THIS IT CERTAINLY APPEARS THE
GREATER RISK FOR SEVERE WEATHER THIS AFTERNOON AND EVENING WILL
EXIST FARTHER NORTHEAST INTO THE UPPER MISSISSIPPI VALLEY WHERE
GREATER VALUES OF INSTABILITY WILL BE OBSERVED...BUT AN ISOLATED
REPORT OF LARGE HAIL CANNOT BE RULED OUT ACROSS OUR AREA WITH THE
AFOREMENTIONED INSTABILITY IN PLACE. IN ADDITION...SIMULATED
REFLECTIVITY FIELDS FROM THE 15/12Z 4KM WRF-NMM SUGGEST A
QLCS...ALBEIT DISORGANIZED...COULD BE REALIZED ALONG THE LOW LEVEL
BAROCLINIC ZONE FROM THE UPPER MISSISSIPPI VALLEY INTO PORTIONS OF
THE MISSOURI RIVER VALLEY...WITH THE VERY SOUTHWESTERN EXTENT OF
THIS SYSTEM PERHAPS CLIPPING OUR NORTHEASTERN CWA. GIVEN ALL
THIS...WILL GO AHEAD AND CONTINUE TO CARRY SEVERE STORM WORDING IN
THE HWO FOR LATE THIS AFTERNOON THROUGH THIS EVENING...WITH
NORTHEASTERN PORTIONS OF OUR CWA THE MOST LIKELY AREA TO OBSERVE
SEVERE WEATHER ACROSS OUR AREA.
SURFACE TEMPERATURES ACROSS THE CENTRAL PLAINS REMAIN IN THE UPPER
70S TO LOW 80S AS OF 17Z...WITH MOST LOCATIONS ALSO REPORTING A
SOUTH/SOUTHEASTERLY SURFACE WIND. GIVEN THESE CURRENT
TEMPERATURES...ALONG WITH THE LOW LEVEL WIND FIELD...AND THE
POSSIBLE IMPACTS OF INCOMING SMOKE FROM THE WESTERN CONUS
WILDFIRES...AM VERY DOUBTFUL TEMPERATURES ARE GOING TO RISE MUCH
MORE THAN 15 DEGREES THROUGH THE REST OF THIS AFTERNOON. GIVEN ALL
THIS...OPTED TO DECREASE AFTERNOON HIGHS A TOUCH...WHICH NOW
RESULTS WITH AFTERNOON HIGHS GENERALLY IN THE LOW TO MID
90S...WITH UPPER 90S STILL FORECAST ACROSS OUR SOUTHWEST. THIS
DECREASE IN AFTERNOON TEMPERATURES ALSO PRESENTS LITTLE TO NO FIRE
WEATHER DANGER ACROSS OUR SOUTHWEST THIS AFTERNOON...SO WILL GO
AHEAD AND REMOVE FIRE WEATHER CONCERNS FROM THE HWO.
&&
.PREV DISCUSSION... /ISSUED 1214 PM CDT WED AUG 15 2012/
AVIATION...18Z KGRI TAF. VFR CONDITIONS EXPECTED THROUGH THE NEXT
24 HOURS. CLEAR SKIES WILL PERSIST UNTIL MID TO HIGH LEVEL CLOUDS
NEAR 11000FT AGL INFILTRATE THE AREA LATER THIS AFTERNOON.
CEILINGS NEAR 6000FT AGL WILL ALSO BE POSSIBLE AS PRECIPITATION
MOVES INTO THE AREA AFTER 00Z. SURFACE WINDS WILL REMAIN FROM THE
SOUTH FOR THE MOST PART THROUGH 23Z...TRANSITIONING TO THE
NORTH/NORTHWEST SHORTLY THEREAFTER AS A LOW LEVEL BAROCLINIC ZONE
CLEARS THE AREA...WITH SUSTAINED WINDS NEAR 14KTS CURRENTLY
EXPECTED AT THE TERMINAL POST-FROPA. TEMPORARY BUT MINOR
VISIBILITY RESTRICTIONS NEAR 6SM WILL BE POSSIBLE IN MODERATE
PRECIPITATION...PRIMARILY DURING THE 00Z-03Z TIME FRAME.
PREV DISCUSSION... /ISSUED 410 AM CDT WED AUG 15 2012/
SHORT TERM...TODAY THROUGH FRIDAY NIGHT. PRIMARY FORECAST CONCERNS
LIE WITH TODAYS APPROACHING COLD FRONT...AND RESULTING
PRECIPITATION CHANCES.
QUIET CONDITIONS CONTINUE ON ACROSS THE AREA EARLY THIS
MORNING...WITH SATELLITE AND PROFILER DATA SHOWING NORTHWESTERLY
FLOW IN PLACE IN THE UPPER LEVELS. SATELLITE IMAGERY ALSO SHOWS
THE UPPER LEVEL TROUGH EXPECTED TO MAKE FOR A MORE ACTIVE PERIOD
LATER TODAY/TONIGHT SHIFTING INTO MONTANA. AT THE SURFACE...THE
CWA SITS BETWEEN HIGH PRESSURE EXTENDING FROM THE GREAT LAKES TO
THE GULF COAST...AND LOW PRESSURE AFFECTING WRN NEB/DAKOTAS...WITH
THE MAIN COLD FRONT CURRENTLY OVER WRN ND INTO MONTANA.
REALLY HASNT BEEN ANY SIGNIFICANT CHANGES WITH THE MODELS OVER THE
PAST 24 HOURS...THE MAIN STORY CONTINUES TO LIE WITH THE ABOVE
MENTIONED UPPER LEVEL TROUGH MAKING ITS WAY FURTHER E/SE THROUGH
THE DAY....PUSHING A STRONG COLD FRONT TOWARD THE CWA. THE TIMING
OF THE FRONT REMAINS PRETTY SIMILAR...WITH IT LOOKING TO BE IN
REALLY CLOSE PROXIMITY TO THE NORTHWEST CORNER OF THE CWA BY 21Z
THIS AFTERNOON...AND BY 00Z IS CENTERED ROUGHLY OVER A FULLERTON
TO KEARNEY TO ALMA NEBRASKA LINE. OUT AHEAD OF THE FRONT
TODAY...WITH A TIGHTENING SFC PRESSURE GRADIENT AND INCREASED
MIXING POTENTIAL...EXPECTING GUSTY SOUTH/SOUTHWESTERLY
WINDS...WITH SPEEDS OF 15 TO 25 MPH AND HIGHER GUSTS. THE GUSTY
WINDS DONT GO AWAY ONCE THE FRONT PASSES...COLD AIR ADVECTION AND
PRESSURE RISES BEHIND THE FRONT WILL RESULT IN ADDITIONAL GUSTY
WINDS...JUST FROM THE NORTH INSTEAD.
DEWPOINTS/TEMPS FOR TODAY ARE TRICKY...WITH HIGHER DEWPOINTS /IN
THE LOWER 60S/ EXPECTED TO POOL AHEAD OF THE FRONT...WHICH LOOKS
TO AFFECT MAINLY THE NORTHWEST HALF OF THE CWA THIS
AFTERNOON...WHILE LOCATIONS FURTHER SOUTH SHOULD SEE DEWPOINTS
FALLING OFF /POTENTIALLY INTO THE LOWER 50S/ AS MIXING INCREASES
WITH WINDS SHIFTING A BIT MORE TO THE SW. DECIDED TO KEEP HIGH
TEMPERATURES FOR TODAY IN THE MID 90S TO NEAR 100...AND WITH THE
FORECAST DEWPOINTS LEADS TO RH VALUES THIS AFTERNOON DROPPING OFF
INTO THE MID/LOWER 20 PERCENT RANGE. ALONG WITH THE GUSTY WINDS
EXPECTED THIS RESULTS IN INCREASED FIRE WEATHER CONCERNS...BUT
CURRENT FORECAST DOES NOT MEET CRITICAL FIRE WEATHER LEVELS...SO
WILL HOLD OFF ON ANY HEADLINE. THIS WILL BE SOMETHING FOR THE DAY
SHIFT TO KEEP A CLOSE EYE ON HOWEVER...WOULDNT TAKE A NOTABLE DROP
IN DEWPOINTS TO PUSH CONDITIONS CLOSER TO THE 20 PERCENT RH MARK.
THE FIRST HALF OF THE DAY AND INTO THE EARLY AFTERNOON...FORECAST
REMAINS DRY WITH WARMER MID LEVEL TEMPS IN PLACE AND WITH THE MAIN
FORCING MECHANISMS STILL MAKING THEIR WAY TOWARD THE CWA...BUT
CHANCES WILL BE ON THE INCREASE AS WE GET INTO THE LATE AFTERNOON
HOURS. ACTIVITY EXPECTED TO INCREASE IN COVERAGE THROUGH THE
EVENING HOURS AS THE FRONT CONTINUES TO PUSH SOUTHEAST THROUGH THE
CWA...WHICH IS REFLECTED BY THE HIGHER POPS IN PLACE FROM
00-06Z...THOUGH THUNDERSTORM CHANCES CONTINUE ON POST-06Z. STILL
CONCERNED ABOUT THE POTENTIAL FOR STRONG TO SEVERE WEATHER...WITH
GOOD VALUES OF MUCAPE LOOKING TO DEVELOP THIS AFTERNOON...AND
WHILE DEEP LAYER SHEAR ISNT THE GREATEST...ITS SUFFICIENT ENOUGH
TO AT LEAST POSE THAT THREAT. THE HIGHER POPS ARE IN PLACE ACROSS
THE NORTHEASTERN HALF OF THE CWA...CLOSER TO THE BETTER MID/UPPER
LEVEL FORCING...THEN DIMINISHING TO THE SOUTHWEST.
ONCE 12Z THURSDAY MORNING ROLLS AROUND...CONTINUE SOME SMALL
LINGERING POPS ACROSS THE SOUTHEASTERN CORNER OF THE CWA
ASSOCIATED WITH THE OVERNIGHT ACTIVITY...BUT ALSO AM CONCERNED
ABOUT THE POTENTIAL FOR SOME POST FRONTAL SHOWERS ACROSS THE
NORTHERN CWA AS THE MAIN UPPER LEVEL TROUGH AXIS CONTINUES TO
SWING THROUGH...SO DID INSERT SOME SLIGHT CHANCE POPS. OUTSIDE OF
THOSE MORNING CHANCES...QUIET CONDITIONS ARE EXPECTED. THE SFC
COLD FRONT WILL BE SOUTH OF THE CWA...WITH NORTHERLY WINDS
REMAINING IN PLACE AS SURFACE HIGH PRESSURE BUILDS IN FROM THE
NORTH BEHIND THE FRONT...THOUGH SPEEDS WILL BE DIMINISHING THROUGH
THE DAY. CERTAINLY WILL BE A NOTICEABLE CHANGE IN
TEMPERATURES...GOING FROM THE 90S/NEAR 100 TODAY TO THE MID/UPPER
70S FOR HIGHS ON THURSDAY. ALONG WITH THE DIMINISHING WIND SPEEDS
AS THAT SURFACE HIGH BUILDS IN...THE ACCOMPANYING AIRMASS WILL
ALSO BE USHERING IN LOWER DEWPOINTS THROUGH THE
AFTERNOON...LOOKING TO FALL INTO THE 40S FOR MOST LOCATIONS. THE
OVERNIGHT HOURS THURSDAY INTO FRIDAY REMAIN QUIET IN THE WAKE OF
TODAYS SYSTEM...WITH CONTINUED CLEARING SKIES...AND THE SURFACE
HIGH PRESSURE SETTLING IN RIGHT OVER THE CWA. WITH THE DRIER
DEWPOINTS IN PLACE...LIGHT/CALM WINDS AND LITTLE CLOUD
COVER...EXPECTING LOW TEMPERATURES TO REALLY FALL OFF. LOWERED
TEMPERATURES A FEW DEGREES...WITH THE FORECAST NOW CALLING FOR MID
40S IN THE NORTH TO LOWER 50S IN THE SOUTH.
LOOKING TOWARD FRIDAY/FRIDAY NIGHT...EXPECTING THE DAYTIME HOURS
TO REMAIN QUIET WITH CONTINUED NORTHWESTERLY FLOW IN PLACE IN THE
UPPER LEVELS...BUT PRECIPITATION CHANCES CREEP BACK INTO PORTIONS
OF THE CWA DURING THE EVENING/OVERNIGHT HOURS...AS ANOTHER WEAK
UPPER LEVEL DISTURBANCE MOVES IN...AND WE SEE SOME INCREASED
WAA/THETAE ADVECTION AS A SRLY LLJ NOSES INTO THE REGION. DURING
THE DAYTIME HOURS...SEE A RETURN TO MORE SOUTHERLY WINDS AS THE
SURFACE HIGH SLIDES OFF TO THE EAST OF THE CWA...AND START TO SEE
WARMER AIR BUILDING BACK IN FROM THE WEST. NOT EXPECTING A NOTABLE
CHANGE IN TEMPS...BUT SHOULD SEE A BUMP UP FROM THURSDAY OF A
COUPLE DEGREES.
LONG TERM...STARTING 12Z SATURDAY...AN UNSEASONABLY COOL
WEEKEND...WITH AFTERNOON TEMPERATURES RUNNING 8-10 DEGREES BELOW
SEASONAL NORMALS...ALONG WITH A SMALL CHANCE OF PRECIP...APPEARS
TO BE ON TAP ACROSS THE REGION.
LOOKING AT THE LARGE SCALE PATTERN...THE PERIOD BEGINS WITH THE
LOCAL AREA SANDWICHED BETWEEN A RIDGE OF HIGH PRESSURE STRETCHED
ACROSS THE INTERMOUNTAIN WEST...AND A LARGE TROUGH OF LOW PRESSURE
ACROSS THE EASTERN HALF OF THE COUNTRY. THIS WILL RESULT IN A
FAIRLY PROGRESSIVE NORTHWESTERLY FLOW IN THE UPPER LEVELS OF THE
ATMOSPHERE ACROSS THE LOCAL AREA BEGINNING SATURDAY...WITH AN
EMBEDDED UPPER LEVEL DISTURBANCE COMING OVER THE TOP OF THE RIDGE
EXPECTED TO BRING AT LEAST A SMALL CHANCE FOR SOME SHOWERS AND
THUNDERSTORMS SATURDAY AFTERNOON THROUGH EARLY SUNDAY MORNING.
THEREAFTER...THE RIDGE AXIS ACROSS THE WEST IS EXPECTED TO FLATTEN
OUT AS IT SHIFTS EAST LATER IN THE WEEKEND...RESULTING IN A SLIGHT
WARMING TREND AND GENERALLY DRY CONDITIONS TO START OFF THE NEW
WORK WEEK. EVEN SO...A ZONAL TO NORTHWESTERLY FLOW PATTERN ALOFT
WILL MANAGE TO CONTINUE ACROSS THE LOCAL AREA...AND COULD SEE
ANOTHER UPPER LEVEL DISTURBANCE TRAVERSE THE PLAINS IN THIS FLOW
EARLY IN THE NEW WORK WEEK. WHILE TIMING IS STILL SOMEWHAT IN
QUESTION...SOME AGREEMENT BRINGING ANOTHER DISTURBANCE ACROSS THE
LOCAL AREA ON TUESDAY...AND USED THIS REASONING TO KEEP BLENDED
SLIGHT CHANCE POPS ACROSS MUCH OF THE AREA LATE MONDAY NIGHT
THROUGH TUESDAY. AT THIS POINT...IF ANY THUNDERSTORMS DO DEVELOP
OVER THIS TIME PERIOD...IT APPEARS THAT WITH MODEST INSTABILITY
AND SHEAR IN PLACE ACROSS THE REGION...WE CAN EXPECT AT LEAST THE
POTENTIAL FOR A FEW STRONG TO SEVERE STORMS...AND WILL ADVERTISE
THIS POTENTIAL IN HWO.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
1258 PM UPDATE/AVIATION...BRYANT
SHORT TERM...ADO
LONG TERM...ROSSI
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
300 PM MDT WED AUG 15 2012
.DISCUSSION...
NO SIGNIFICANT CHANGES MADE FROM PREVIOUS FORECAST. CIRA BLENDED TPW
IMAGERY SHOWS THE BEST MOISTURE AXIS ACROSS CENTRAL AND EASTERN AZ...
WHILE AN AREA OF DRIER AIR HAS WORKED SLOWLY SOUTHWARD INTO THE FAR
NORTHERN REGION OF NM. 20Z LAPS INSTABILITY CONSISTENT WITH LATEST
RADAR TRENDS WHERE MAJORITY OF ACTIVITY NEAR AND SE OF THE CENTRAL MT
CHAIN. HRRR GUIDANCE PERFORMED WELL ON TUESDAY AND CAPTURES CURRENT
CONDITIONS SO HAVE NUDGED POPS TOWARD ITS SOLUTION FOR THIS EVENING.
EXPECT NW STEERING FLOW TO PUSH ACTIVITY INTO THE PLAINS WHILE CENTRAL
AND WESTERN NM ACTS ON OUTFLOW BOUNDARIES FOR STORMS.
THE MUCH ANTICIPATED BACK DOOR FRONTAL BOUNDARY IS GATHERING STRENGTH
OVER NE COLORADO. 20Z SURFACE OBS AND MODEL FRONTOGENESIS SUPPORTS A
RATHER STRONG BOUNDARY PUSHING SOUTH INTO NE NM THRU TONIGHT...WITH
BREEZY CONDITIONS IN ITS WAKE. THIS FRONT WILL ACT AS A STRONG FOCUS
FOR SHOWERS AND STORMS THURSDAY ALONG AND EAST OF THE CENTRAL MT
CHAIN. NW FLOW ALOFT BENEATH THE RIDGE CENTERED OVER E AZ WILL COMBINE
WITH LOW LEVEL UPSLOPE FLOW TO PRODUCE SCT TO NMRS COVERAGE DURING THE
AFTERNOON THEN A POTENTIAL COMPLEX THURSDAY EVENING OVER THE PLAINS.
GAP WINDS INTO THE RIO GRANDE VALLEY MAY BE ENHANCED BY CONVECTION
DEPENDING ON WHERE STORMS FIRE. SE STEERING FLOW UP TO 650MB INTO THE
RIO GRANDE VALLEY WILL ALLOW SOME STORMS TO MAKE IT INTO THE AREA FROM
THE SANDIA/MANZANO MTS. RAISED POPS ANOTHER FEW POINTS.
THE OVERALL PATTERN WILL BE PERSISTENT THRU THE WEEKEND WITH NW FLOW
ALOFT AND LOW LEVEL MOIST SOUTH TO SOUTHEASTERLY FLOW. THIS WILL
MAKE FOR WHAT WILL LIKELY BE THE BEST EXTENDED PERIOD OF DECENT
PRECIP CHANCES ACROSS THE E PLAINS IN QUITE SOME TIME. HAVE CONTINUED
WITH POPS JUST BELOW LIKELY CATEGORY FOR THE EAST WHERE CONVECTION
DEVELOPING OVER THE HIGH TERRAIN WILL ORGANIZE INTO AREAS OF STORMS
AND RAIN EACH EVENING. TEMPS WILL BE BELOW NORMAL AS WELL OUT EAST
WHICH WILL BE QUITE A CHANGE FROM THE PAST COUPLE MONTHS. THE GFS IS
ALSO SHOWING SOME OF THE MONSOON MOISTURE CURRENTLY OVER NORTHERN
MEXICO SEEPING NORTH INTO THE SW MTS...ENHANCING ACTIVITY OVER THAT
REGION AS WELL. WAS A LITTLE CONSERVATIVE WITH POPS IN THAT AREA BUT
THIS NEEDS TO BE WATCHED AS LOW LEVEL MOISTURE CAN SURGE NORTH VERY
QUICKLY FROM JUST ONE STRONG CONVECTIVE COMPLEX TO THE SOUTH AT ANY
TIME.
GUIDANCE BEYOND THE WEEKEND CONTINUES TO WAFFLE BACK AND FORTH WHERE
THE HIGH CENTER WILL BE SO CONFIDENCE QUITE LOW FOR NEXT WEEK. GUYER
&&
.FIRE WEATHER...
THE UPPER HIGH IS FORECAST TO CONTINUE AS THE DOMINANT WEATHER
FEATURE THROUGH THE NEXT SEVEN DAYS...ALTHOUGH TWO BACKDOOR FRONTAL
SURGES WILL ADD MOISTURE TO THE EQUATION.
A WEAK COLD FRONT WILL PUSH SOUTHWEST ACROSS THE STATE THURSDAY...
PUSHING LOW LAYER MOISTURE WEST TO THE CONTINENTAL DIVIDE AND
RESULTING IN AN UPTICK IN WETTING SHOWERS AND THUNDERSTORMS. BREEZY
EAST CANYON WINDS ARE FORECAST TO ACCOMPANY THE FRONTAL PASSAGE
THROUGH THE CENTRAL MOUNTAIN CHAIN LATE THURSDAY. RELATIVE HUMIDITIES
WILL TREND UP BEHIND THE FRONT AND TEMPERATURES WILL TREND DOWN
SLIGHTLY THROUGH FRIDAY...ESPECIALLY ALONG/EAST OF THE CENTRAL
MOUNTAIN CHAIN WHERE THE BEST CHANCES FOR WETTING RAIN WILL RESIDE.
ANOTHER WEAK FRONTAL PUSH WILL COME DOWN THE PLAINS SATURDAY
NIGHT...KEEPING GOOD CHANCES FOR WETTING RAINS GOING THROUGH THE
WEEKEND WITH THE BEST CHANCES ALONG/EAST OF THE CENTRAL MOUNTAIN
CHAIN AROUND THE PERIPHERY OF THE UPPER HIGH. OVERNIGHT HUMIDITY
RECOVERIES WILL BE GOOD TO EXCELLENT THROUGH THE WEEKEND THANKS TO
THE ADDED POST-FRONTAL MOISTURE.
RECYCLE MODE IS FORECAST EARLY NEXT WEEK WITH ABOVE NORMAL
TEMPERATURES. LOWER CONFIDENCE FORECAST GOING INTO MID WEEK WITH
DIFFERENCES AMONG THE 12Z MEDIUM RANGE MODEL SOLUTIONS IN THE
PLACEMENT OF THE UPPER HIGH. THE 12Z GFS SHUTS-DOWN THE EAST AND
FAVORS THE WEST AND NORTH FOR WETTING RAINS WITH THE UPPER HIGH
CENTERED OVER FAR WEST TEXAS BY LATE NEXT WEDNESDAY. A TREND BACK
TOWARD LOWER CHANCES FOR WETTING RAINS AND ABOVE NORMAL TEMPERATURE
WOULD FIT THE RECENT PATTERN AND IS THE MOST LIKELY SOLUTION. 11
&&
.AVIATION...
18Z TAF CYCLE
VFR CONDITIONS FORECAST THROUGH THE TAF PERIOD EXCEPT FOR BRIEF
MVFR CONDITIONS WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS
THIS AFTERNOON AND EVENING. STEERING FLOW FAVORING KLVS AND
KSAF...BUT POSSIBLE AT KABQ...KTCC AND KROW AS WELL LATE DAY.
A COLD FRONT IS FORECAST TO PUSH INTO THE NORTHEAST PLAINS AND
SPREAD SOUTHWEST OVERNIGHT...WITH A WIND SHIFT AT KLVS AT 11Z...
KTCC AT 13Z...KROW AT 16Z AND KSAF AT 17Z. AN EAST GAP WIND IS
EXPECTED AT KABQ LATE THURSDAY AFTERNOON AND OVERNIGHT INTO FRIDAY
MORNING. 11
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 60 95 66 94 / 5 10 20 10
DULCE........................... 49 91 51 87 / 10 20 30 20
CUBA............................ 54 91 55 86 / 10 20 30 50
GALLUP.......................... 55 93 58 88 / 10 10 20 20
EL MORRO........................ 51 81 54 81 / 20 20 30 40
GRANTS.......................... 51 88 55 84 / 10 20 30 30
QUEMADO......................... 55 92 57 86 / 20 30 40 40
GLENWOOD........................ 60 92 56 89 / 20 30 30 40
CHAMA........................... 50 83 52 78 / 20 30 40 40
LOS ALAMOS...................... 60 86 61 83 / 20 30 40 60
PECOS........................... 57 79 57 76 / 30 50 40 50
CERRO/QUESTA.................... 53 79 53 76 / 30 50 50 40
RED RIVER....................... 46 71 48 69 / 40 60 50 60
ANGEL FIRE...................... 46 72 46 70 / 30 60 50 60
TAOS............................ 52 85 54 82 / 30 40 40 40
MORA............................ 53 75 53 72 / 30 40 50 50
ESPANOLA........................ 58 89 60 89 / 20 30 40 40
SANTA FE........................ 60 84 61 81 / 20 40 40 50
SANTA FE AIRPORT................ 61 89 62 86 / 20 40 40 50
ALBUQUERQUE FOOTHILLS........... 66 89 65 89 / 10 30 40 40
ALBUQUERQUE HEIGHTS............. 68 91 67 91 / 10 30 30 30
ALBUQUERQUE VALLEY.............. 65 93 65 93 / 10 30 30 30
ALBUQUERQUE WEST MESA........... 65 93 65 91 / 10 20 30 30
LOS LUNAS....................... 63 92 63 93 / 20 30 30 30
RIO RANCHO...................... 65 92 65 90 / 10 30 30 30
SOCORRO......................... 66 98 66 94 / 20 30 30 40
SANDIA PARK/CEDAR CREST......... 59 86 59 86 / 20 40 40 60
TIJERAS......................... 61 89 60 89 / 20 40 30 50
MORIARTY/ESTANCIA............... 58 84 57 82 / 20 50 40 60
CLINES CORNERS.................. 58 83 59 83 / 20 50 40 60
GRAN QUIVIRA.................... 61 87 61 86 / 20 40 40 50
CARRIZOZO....................... 62 90 63 88 / 20 40 40 50
RUIDOSO......................... 58 79 58 79 / 30 50 40 50
CAPULIN......................... 56 76 55 79 / 30 30 40 40
RATON........................... 62 85 60 88 / 30 30 40 40
SPRINGER........................ 60 83 61 83 / 30 30 40 40
LAS VEGAS....................... 55 81 56 81 / 30 40 50 50
CLAYTON......................... 60 82 61 82 / 30 20 30 40
ROY............................. 63 82 63 82 / 30 30 50 50
CONCHAS......................... 66 87 70 87 / 30 40 40 40
SANTA ROSA...................... 66 90 68 92 / 20 40 40 50
TUCUMCARI....................... 67 94 70 90 / 30 30 40 50
CLOVIS.......................... 68 92 69 89 / 30 30 40 40
PORTALES........................ 69 92 71 90 / 30 30 30 40
FORT SUMNER..................... 69 91 71 91 / 20 30 30 40
ROSWELL......................... 71 94 72 90 / 20 30 20 40
PICACHO......................... 63 88 62 86 / 20 30 20 40
ELK............................. 61 83 61 81 / 30 40 30 40
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
GUYER
AREA FORECAST DISCUSSION
NWS BUFFALO NY
353 PM EDT WED AUG 15 2012
.SYNOPSIS...
ISOLATED SHOWERS WILL CLEAR OUT OF THE AREA THIS EVENING AS HIGH
PRESSURE BUILDS IN GIVING THE REGION A BEAUTIFUL DAY ON THURSDAY
WITH SEASONABLE TEMPERATURES. A COLD FRONT WILL MOVE THROUGH THE
AREA PROVIDING SHOWERS AND THUNDERSTORMS ON THURSDAY NIGHT OR
FRIDAY. FOLLOWING THE PASSAGE OF THE COLD FRONT EXPECT COOLER
TEMPERATURES AND LESS HUMID CONDITIONS FOR THIS UPCOMING WEEKEND.
&&
.NEAR TERM /THROUGH THURSDAY/...
UPPER LEVEL TROUGH/COOL AIR ALOFT IN PLACE ACROSS THE CENTRAL AND
EASTERN GREAT LAKES AND WITH TROUGH AXIS THAT EXTENDS FROM HUDSON
BAY SOUTH TO WEST VIRGINIA THIS AFTERNOON. AT THE SURFACE... WEAK
LOW CENTERED OVER SOUTHEASTERN QUEBEC WITH BROAD HIGH PRESSURE OHIO
VALLEY EXTENDING INTO FAR WESTERN NY. AREA RADARS PICKING UP ON SOME
THUNDERSTORMS WELL TO THE WEST OF THE FORECAST AREA BETWEEN LAKES
HURON AND ONTARIO ORIENTED ALONG THE UPPER LEVEL TROUGH AXIS.
ELSEWHERE CONDITIONS ARE DRY WITH SCATTERED SHOWERS CONFINED TO
CENTRAL AND EASTERN NY. WILL MONITOR ACTIVITY TO THE WEST THROUGH
THE REST OF THE AFTERNOON FOR APPROACH TO WESTERN NY/LAKE ONTARIO.
15Z HRRR MODEL BREAKS UP THIS ACTIVITY BY 00Z WITH THE LOST OF
DAYTIME HEATING. WILL CONTINUE WITH LOW/CHANCE POPS FOR SHOWERS AND
SHIFT THIS EASTWARD THROUGH THE EVENING TO COVER FOR ANY ADDITIONAL
POP-UP ACTIVITY SINCE CU IS QUIET ENHANCED THIS AFTERNOON.
TONIGHT...ANY CONVECTION ACROSS EASTERN SECTIONS WILL WIND DOWN THIS
EVENING WITH THE LOSS OF HEATING AND THE DEPARTURE OF THE MAIN
SURFACE LOW/DEEPER MOISTURE INTO NEW ENGLAND. HIGH PRESSURE OVER THE
OHIO VALLEY ALONG WITH DRIER AIR WILL BUILD WEST AND CENTER DIRECTLY
OVERHEAD. THIS WILL ALSO BRING CLEARING SKIES...WHICH WHEN COUPLED
WITH LIGHT WINDS WILL ALLOW FOR SOME VALLEY FOG TO DEVELOP ACROSS
THE SOUTHERN TIER OVERNIGHT. LOWS TONIGHT WILL FALL INTO THE MID 50S
TO LOW 60S...THOUGH INTERIOR SECTIONS OF THE SOUTHERN TIER COULD SEE
READINGS DROP TO AROUND THE 50 DEGREE MARK.
ON THURSDAY EXPECTING VERY PLEASANT CONDITIONS AS SURFACE HIGH
CENTERS OVER THE CAROLINAS WITH RIDGING ACROSS NY. MOSTLY SUNNY
SKIES WITH SOUTHWEST WINDS. WITH THE SOUTHWEST FLOW WILL SEE 850MB
TEMPS CLIMB TO AROUND +14C TO +16C WHICH WILL RESULT IN SURFACE
TEMPS IN THE LOW 80S. SOME HIGH CLOUDS MAY STREAM IN LATE AHEAD OF A
COLD FRONT APPROACHING FROM THE MIDWEST.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
THURSDAY NIGHT WILL MARK THE BEGINNING OF THE TRANSITION TO A COOLER
REGIME ACROSS THE GREAT LAKES AS A POTENT SHORTWAVE CURRENTLY OVER
THE SOUTHERN CANADIAN ROCKIES PHASES WITH ANOTHER SHORTWAVE ROTATING
AROUND A POLAR LOW OVER THE CANADIAN ARCTIC...TAPPING INTO AN ARCTIC
AIRMASS ORIGINATING IN NORTHWESTERN CANADA AND STRENGTHENING INTO A
LARGE UPPER LOW OVER WESTERN ONTARIO BY THURSDAY EVENING. A WELL
DEFINED COLD FRONT ON THE LEADING EDGE OF THIS AIRMASS WILL SWEEP
ACROSS THE UPPER GREAT LAKES THURSDAY AND INTO THE LOWER GREAT LAKES
THURSDAY NIGHT...ARRIVING ON OUR DOORSTEP IN THE NIAGARA FRONTIER DURING THE
WEE HOURS OF FRIDAY MORNING. WARM ADVECTION AHEAD OF THIS SYSTEM AND
INCREASING CLOUD COVER AHEAD OF THE FRONT WILL KEEP TEMPERATURES
PROPPED UP IN THE MID TO UPPER 60S.
REGARDING THE CHANCES FOR CONVECTION FOR THURSDAY NIGHT INTO
FRIDAY...GIVEN THE TIMING OF THE FRONTAL PASSAGE INTO WESTERN NEW
YORK EARLY FRIDAY MORNING THERE IS LITTLE IN THE WAY OF AMBIENT
INSTABILITY AND THE BULK OF ANY ASCENT WILL BE ASSOCIATED WITH THE
SURFACE CONVERGENCE/ASCENT FRONT ITSELF AND STRONG PVA ASSOCIATED
WITH THE UPPER LEVEL TROUGH. HOWEVER...BUFKIT PROFILES INDICATE THAT
THE WARM WATERS OF THE GREAT LAKES MAY CREATE ENOUGH LOW LEVEL
INSTABILITY TO OVERCOME WHAT ARE OTHERWISE MEDIOCRE LAPSE RATES.
GIVEN THIS AND THE FAVORABLE SYNOPTIC ENVIRONMENT...THUNDERSTORMS
CANNOT BE RULED OUT. IN ADDITION...WITH A LOW LEVEL JET OF 35-40KT
AT 925MB INCREASING TO 50KT AT 500MB...THE POTENTIAL FOR GUSTY WINDS
ACCOMPANYING THE FRONTAL PASSAGE AND SAID THUNDERSTORMS CERTAINLY
EXISTS...PROVIDED THEY MATERIALIZE...AND THIS WILL CONTINUE TO BE
HIGHLIGHTED IN THE HWO.
THE COLD FRONT WILL RAPIDLY MARCH ACROSS WESTERN AND CENTRAL NEW
YORK DURING THE DAY ON FRIDAY WITH THE BEST SHOT AT PRECIP
IMMEDIATELY ALONG AND JUST AHEAD OF THE FRONT ITSELF. PRECIP WILL
END RAPIDLY BEHIND THE FRONT AS THE DRY CONTINENTAL ARCTIC AIRMASS
ADVECTS INTO THE REGION. TEMPERATURES FRIDAY WILL REFLECT THIS SHIFT
IN AIRMASSES WITH THE WARMEST TEMPERATURES IN THE WESTERN HALF OF
THE CWA OCCURRING BY AROUND NOON WITH HIGHS TOPPING OUT IN THE UPPER
60S TO LOWER 70S BEFORE STABILIZING OR COOLING SLIGHTLY DURING THE
AFTERNOON. FARTHER EAST...TEMPERATURES WILL WARM INTO THE LOW TO MID
70S BEFORE THE FRONTAL PASSAGE COOLS THINGS OFF BY LATE IN THE DAY.
850MB TEMPS DROP TO AROUND +7C BY FRIDAY EVENING HOWEVER ANY LAKE
RESPONSE WILL LIKELY BE LIMITED TO JUST INCREASED STRATO-CU DOWNSTREAM
OF THE LAKES AS MID-LEVELS WILL BE EXTREMELY DRY AND FLOW WILL BE
STRONGLY SHEARED. IT WILL CERTAINLY FEEL LIKE EARLY AUTUMN AS
TEMPERATURES DROP INTO THE 50S WITH EVEN COOLER READINGS IN INTERIOR
VALLEYS DROPPING INTO THE UPPER 40S. SATURDAY SHOULD BE A VERY
PLEASANT DAY WITH PLENTY OF SUNSHINE TO GO AROUND WITH THE EXCEPTION
OF AREAS IMMEDIATELY DOWNSTREAM FROM THE LAKES. THE UPPER LOW
RESPONSIBLE FOR THE COOL DOWN WILL CONTINUE TO SPIN NEAR JAMES BAY
WITH THE REGION REMAINING UNDER ITS INFLUENCE WITH THE RESULTING
TEMPERATURES MORE REFLECTIVE OF MID-SEPTEMBER RATHER THAN
MID-AUGUST. GFS IS HINTING AT AN AREA OF INCREASING MID-LEVEL
MOISTURE MOVING ACROSS THE GREAT LAKES SUNDAY NIGHT WHICH COMBINED
WITH BETTER ALIGNED WESTERLY FLOW MAY ALLOW FOR THE DEVELOPMENT OF
LAKE EFFECT RAIN SHOWERS DOWNSTREAM OF LAKE ONTARIO...HOWEVER
CONFIDENCE IN THIS IS LOW AND WILL KEEP POPS LIMITED TO JUST SLIGHT
CHANCE.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
THE LOWER GREAT LAKES WILL REMAIN UNDER THE INFLUENCE OF THE UPPER
LOW THAT REMAINS RELATIVELY STATIONARY IN THE VICINITY OF JAMES BAY
THROUGH MONDAY NIGHT. A SERIES OF WEAK SHORTWAVES WILL ROTATE ACROSS
THE REGION DURING THIS PERIOD...HOWEVER WITH LITTLE IN THE WAY OF
MOISTURE TO WORK WITH...NOT EXPECTING ANYTHING MORE THAN A SLIGHT
CHANCE OF SHOWERS ON MONDAY AND TUESDAY. EXPECT TEMPERATURES TO BEGIN TO
REBOUND ON TUESDAY AS A STRENGTHENING UPPER LEVEL JET OVER NEW
ENGLAND ALONG WITH THE DEPARTURE OF THE LAST OF THE SHORTWAVES
SHUNTS THE UPPER LEVEL LOW AWAY FROM ONTARIO AND OFF INTO THE
CANADIAN MARITIMES LEAVING A MUCH LOWER AMPLITUDE FLOW REGIME ACROSS
THE REGION.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
VFR ALL SITES THROUGH THIS EVENING WITH SOUTHERN TIER SEEING SOME
IFR OR LOWER FOG LATE TONIGHT MAINLY ACROSS THE VALLEYS. RADAR IS
CLEAR THIS AFTERNOON AT ALL TAF SITES WITH JUST A SLIGHT CHANCE OF A
SHOWER. MAIN IMPACT IS JUST ENHANCED TCU THIS AFTERNOON WITH LIMITED
SHOWERS. SOME TSRA IS OBSERVED WEST OF LAKE ONTARIO BUT HIGH-RES
GUIDANCE INDICATES THIS SHOULD FALL APART BEFORE REACHING WNY WITH
THE LOST OF HEATING. HIGH PRESSURE AND DRIER AIR WILL BUILD INTO THE
REGION TONIGHT WITH CIGS SCATTERING OUT. WITH THE CLEARING SKIES AND
LIGHT WINDS...SOME VALLEY FOG WILL BE POSSIBLE ACROSS THE SOUTHERN
TIER LATE. HIGH PRESSURE RIDGED OVER THE REGION ON THURSDAY WILL
RESULT MAINLY CLEAR SKIES AND SOUTHWEST WINDS.
OUTLOOK...
THURSDAY NIGHT AND FRIDAY...A PERIOD OF SHOWERS/THUNDERSTORMS WITH
ASSOCIATED MVFR...OTHERWISE VFR.
SATURDAY...POSSIBLE MVFR/IFR FOG EARLY OTHERWISE VFR.
SUNDAY...VFR.
MONDAY...CHANCE OF SHOWERS/TSTRMS. MAINLY VFR.
&&
.MARINE...
WINDS AND WAVES WILL REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA
THROUGH THURSDAY WITH FAIR WEATHER. BUFFALO RADAR SHOWS SOME SHOWERS
AND THUNDERSTORMS NORTH OF LAKE ERIE BUT EXPECT WILL DISSIPATE
BEFORE ARRIVING TO WNY. NO IMPACTS FOR THE NEARSHORES. MOSTLY SUNNY
SKIES THURSDAY WITH LIGHT SOUTHWEST WINDS AS SURFACE RIDGING SHIFTS
OVER THE REGION.
THURSDAY NIGHT AND FRIDAY...A COLD FRONT WILL CROSS THE LOWER LAKES
ALONG WITH THE LIKELIHOOD OF ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS...SOME OF WHICH COULD PRODUCE LOCALLY GUSTY WINDS.
BEHIND THE FRONT...A BRISK WESTERLY FLOW OF COOLER AIR WILL SET UP
ACROSS LAKE ONTARIO ON FRIDAY...WITH WINDS AND WAVES POTENTIALLY
REACHING ADVISORY CRITERIA.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...JJR/SMITH
SHORT TERM...WOOD
LONG TERM...WOOD
AVIATION...SMITH
MARINE...JJR/SMITH
AREA FORECAST DISCUSSION
NWS BUFFALO NY
310 PM EDT WED AUG 15 2012
.SYNOPSIS...
ISOLATED SHOWERS WILL CLEAR OUT OF THE AREA THIS EVENING AS HIGH
PRESSURE BUILDS IN GIVING THE REGION A BEAUTIFUL DAY ON THURSDAY
WITH SEASONABLE TEMPERATURES. A COLD FRONT WILL MOVE THROUGH THE
AREA PROVIDING SHOWERS AND THUNDERSTORMS ON THURSDAY NIGHT OR
FRIDAY. FOLLOWING THE PASSAGE OF THE COLD FRONT EXPECT COOLER
TEMPERATURES AND LESS HUMID CONDITIONS FOR THIS UPCOMING WEEKEND.
&&
.NEAR TERM /THROUGH THURSDAY/...
UPPER LEVEL TROUGH/COOL AIR ALOFT IN PLACE ACROSS THE CENTRAL AND
EASTERN GREAT LAKES AND WITH TROUGH AXIS THAT EXTENDS FROM HUDSON
BAY SOUTH TO WEST VIRGINIA THIS AFTERNOON. AT THE SURFACE... WEAK
LOW CENTERED OVER SOUTHEASTERN QUEBEC WITH BROAD HIGH PRESSURE OHIO
VALLEY EXTENDING INTO FAR WESTERN NY. AREA RADARS PICKING UP ON SOME
THUNDERSTORMS WELL TO THE WEST OF THE FORECAST AREA BETWEEN LAKES
HURON AND ONTARIO ORIENTED ALONG THE UPPER LEVEL TROUGH AXIS.
ELSEWHERE CONDITIONS ARE DRY WITH SCATTERED SHOWERS CONFINED TO
CENTRAL AND EASTERN NY. WILL MONITOR ACTIVITY TO THE WEST THROUGH
THE REST OF THE AFTERNOON FOR APPROACH TO WESTERN NY/LAKE ONTARIO.
15Z HRRR MODEL BREAKS UP THIS ACTIVITY BY 00Z WITH THE LOST OF
DAYTIME HEATING. WILL CONTINUE WITH LOW/CHANCE POPS FOR SHOWERS AND
SHIFT THIS EASTWARD THROUGH THE EVENING TO COVER FOR ANY ADDITIONAL
POP-UP ACTIVITY SINCE CU IS QUIET ENHANCED THIS AFTERNOON.
TONIGHT...ANY CONVECTION ACROSS EASTERN SECTIONS WILL WIND DOWN THIS
EVENING WITH THE LOSS OF HEATING AND THE DEPARTURE OF THE MAIN
SURFACE LOW/DEEPER MOISTURE INTO NEW ENGLAND. HIGH PRESSURE OVER THE
OHIO VALLEY ALONG WITH DRIER AIR WILL BUILD WEST AND CENTER DIRECTLY
OVERHEAD. THIS WILL ALSO BRING CLEARING SKIES...WHICH WHEN COUPLED
WITH LIGHT WINDS WILL ALLOW FOR SOME VALLEY FOG TO DEVELOP ACROSS
THE SOUTHERN TIER OVERNIGHT. LOWS TONIGHT WILL FALL INTO THE MID 50S
TO LOW 60S...THOUGH INTERIOR SECTIONS OF THE SOUTHERN TIER COULD SEE
READINGS DROP TO AROUND THE 50 DEGREE MARK.
ON THURSDAY EXPECTING VERY PLEASANT CONDITIONS AS SURFACE HIGH
CENTERS OVER THE CAROLINAS WITH RIDGING ACROSS NY. MOSTLY SUNNY
SKIES WITH SOUTHWEST WINDS. WITH THE SOUTHWEST FLOW WILL SEE 850MB
TEMPS CLIMB TO AROUND +14C TO +16C WHICH WILL RESULT IN SURFACE
TEMPS IN THE LOW 80S. SOME HIGH CLOUDS MAY STREAM IN LATE AHEAD OF A
COLD FRONT APPROACHING FROM THE MIDWEST.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
THIS WILL BE A TRANSITION PERIOD ACROSS THE GREAT LAKES REGION AS WE
WILL FIND OURSELVES IN THE MIDST OF A MAJOR PATTERN CHANGE. IF THIS
WERE MID WINTER...WE WOULD BE LOOKING AT A SIGNIFICANT SHOT OF
ARCTIC AIR WITH THE GREAT LAKES SNOWBELTS LOOKING FORWARD TO
NOTEWORTHY SNOW ACCUMULATIONS. INSTEAD...WE CAN ANTICIPATE SEVERAL
DAYS OF BELOW NORMAL TEMPERATURES AND A PREVIEW OF EARLY FALL. THATS
GETTING A LITTLE AHEAD OF OURSELVES THOUGH.
SETTING THE STAGE FOR THE PATTERN CHANGE WILL BE A POLAR VORTEX THAT
HAS BEEN ANCHORED OVER THE CANADIAN ARCTIC (70N 100W). THE CHILLIEST
AIR IN THE NORTHERN HEMISPHERE IS ASSOCIATED WITH THIS DEEP CLOSED
LOW...AND IT WILL BE A SLICE OF THIS AIRMASS THAT WILL MAKE ITS WAY
SOUTHWARD TO THE LOWER 48....AND IN PARTICULAR...THE GREAT LAKES
REGION. USHERING IN THIS MUCH COOLER AIR WILL BE A POTENT SHORTWAVE
THAT CAN BE SEEN IN WV IMAGERY THIS MORNING DIGGING SOUTHEAST FROM
THE CANADIAN ROCKIES. IT WILL MAKE ITS WAY ACROSS THE PRAIRIES OF
SASKATCHEWAN DURING THE NEXT 24 HOURS BEFORE DIGGING ACROSS THE
GREAT LAKES REGION. THIS WILL EVENTUALLY HELP TO PHASE THE CURRENT
SPLIT FLOW OVER THE EASTERN U.S. AS A DEEP LONGWAVE TROUGH WILL
BECOME ESTABLISHED OVER THE EASTERN HALF OF NORTH AMERICA. THE
DETAILS...
THE AFOREMENTIONED VIGOROUS SHORTWAVE WILL DIG ACROSS THE UPPER
GREAT LAKES ON THURSDAY. THIS WILL AMPLIFY A PROGRESSIVE SHORTWAVE
RIDGE OVER THE LOWER GREAT LAKES IN THE PROCESS WHILE SFC HIGH
PRESSURE WILL NOSE NORTH FROM THE OHIO VALLEY. THE RESULTING
SUBSIDENCE WILL PRODUCE A SUNNY WARM FOR OUR REGION...WITH
MODERATING H85 TEMPS SUPPORTING AFTERNOON TEMPERATURES IN THE 80S.
THE HIGH WILL QUICKLY BE SHUNTED TO OUR SOUTHEAST THURSDAY NIGHT AS
THE DIGGING H5 SHORTWAVE WILL PUSH A COLD FRONTAL BOUNDARY ACROSS
SOUTHERNMOST ONTARIO TO BUFFALO`S DOORSTEP BY DAYBREAK FRIDAY. A
STRENGTHENING SOUTHERLY FLOW AHEAD OF THE FRONT WILL KEEP MERCURY
LEVELS ABV NORMAL THROUGHOUT THE NIGHT...WITH SHOWERS AND GUSTY
THUNDERSTORMS BECOMING LIKELY OVER THE WESTERN COUNTIES AS THE NIGHT
PROGRESSES. WHILE THE DIURNAL TIMING WILL LIMIT THE AMOUNT OF SFC
BASED INSTABILITY AHEAD OF THE FRONT...THIS WILL BE A DYNAMICALLY
DRIVEN CONVECTIVE EVENT WITH UNIFORMILY ALIGNED WINDS AND MODERATE
AMOUNTS OF SPEED SHEAR LENDING TO THE POSSIBILITY FOR STRONG WIND
GUSTS ALONG AND IMMEDIATELY THE FRONTAL PASSAGE. WHILE OUR CWA IS
NOT OUTLINED (SLGT RISK AREA) BY THE STORM PREDICTION CENTER...WE
WILL MENTION THE THREAT IN THE HAZARDOUS WEATHER OUTLOOK PRODUCT.
THE FRONT WILL SWEEP ACROSS WESTERN AND NORTH CENTRAL NEW YORK
FRIDAY MORNING WITH THE 3-4 HOUR WINDOW OF CONVECTION QUICKLY GIVING
WAY TO SUBSIDENCE AND MID LEVEL DRYING...ALONG WITH SIGNIFICANT COLD
AIR ADVECTION. H85 TEMPS THAT WILL BE IN THE VCNTY OF 14C IN THE
MORNING WILL DROP OFF TO AROUND 8C BY EVENING. THIS WILL LIKELY
OFFSET DIURNAL HEATING SO THAT OUR HIGH TEMPERATURES SHOULD BE
EXPERIENCED CLOSER TO LUNCHTIME BEFORE SLOWLY FALLING TEMPERATURES
ARE FELT IN THE AFTERNOON. HIGHS WILL GENERALLY BE IN THE 70S.
THE TRANSITION IN THE LONGWAVE PATTERN WILL BE COMPLETE BY FRIDAY
NIGHT AS A CLOSED OFF H5 LOW WILL BE IN THE VCNTY OF HUDSON BAY
WHILE EXPANSIVE HIGH PRESSURE WILL BE CENTERED OVER THE UPPER
MISSISSIPPI VALLEY. THIS WILL KEEP A COLD ADVECTIVE WEST TO
SOUTHWEST FLOW IN PLACE OVER OUR REGION WITH H85 TEMPS CONTINUING TO
FALL TO ABOUT 6C. WHILE THIS WILL CERTAINLY CREATE SOME INSTABILITY
OVER THE WARM LAKES...A WEALTH OF DRY AIR ALONG WITH A MODERATELY
SHEARED ENVIRONMENT WILL LIMIT THE RESPONSE FROM THE LAKES. WILL
KEEP DRY WEATHER INTACT AT THIS POINT WITH ONLY LIMITED DOWNSTREAM
CLOUD COVER. OVERNIGHT LOWS SHOULD BE IN THE 50S REGIONWIDE WITH
ONLY THE CHILLIES SRN TIER VALLEYS POSSIBLY FEELING TEMPS IN THE
UPPER 40S.
SEASONABLY COOL WEATHER WILL FOLLOW FOR SATURDAY AND SATURDAY NIGHT
AS THE STRONGLY POSITIVE PNA PATTERN WILL BE LOCKED IN PLACE ACROSS
NORTH AMERICA. THIS WILL INCLUDE A FULL LATITUDE TROUGH OVER THE
EASTERN U.S. WITH HIGH PRESSURE EXTENDING FROM THE NORTHERN PLAINS
TO THE MID ATLANTIC REGION. THIS PATTERN WILL KEEP A DIRECT FEED OF
AUTUMN LIKE AIR COMING OUT OF CENTRAL CANADA WITH H85 TEMPS OF ABOUT
8C BEING FOUND OVER OUR FORECAST AREA. SFC TEMPS WILL ONLY REACH THE
THE UPPER 60S ACROSS THE HIGHER ELEVATIONS AS A RESULT WHILE
AFTERNOON TEMPS WILL RANGE FROM 70 TO 75 MOST ELSEWHERE. THESE
READINGS WILL AVERAGE ABOUT 5 DEG F BELOW NORMAL MID AUGUST VALUES.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
WHILE TEMPERATURES ON THE WHOLE WILL REMAIN A LITTLE BELOW NORMAL
DURING THIS PERIOD...WE WILL START TO EXPERIENCE A WARMING TREND.
THE FEED OF AUTUMN LIKE AIR OUT OF THE NW TERRITORIES WILL BASICALLY
EMPTY OUT TO THE SOUTH BY THE END OF THE WEEKEND WHILE AT THE SAME
TIME...THE NEXT SIGNIFICANT SHORTWAVE WILL TRACK ACROSS THE YUKON TO
CUT OFF THE REMAINING NORTHERLY FLOW AND ESTABLISH A PACIFIC BASED
MODERATING TREND. THIS WILL ULTIMATELY BREAK DOWN THE HIGHLY
AMPLIFIED +PNA PATTERN AS THE DOWNSTREAM CLOSED LOW OVER NORTHERN
ONTARIO WILL GET ERODED BY RISING HGTS OVER THE CANADIAN PRAIRIES.
WITHOUT ANY BLOCKING RIDGE OVER THE NORTH ATLANTIC...THE PATTERN
WILL ONCE AGAIN BECOME PROGRESSIVE.
ZOOMING IN TO THE GREAT LAKES REGION...THE DEEP CYCLONIC UPPER LEVEL
FLOW WILL REMAIN IN PLACE WHILE THE DOMINANT SFC FEATURE WILL
CONTINUE TO BE HIGH PRESSURE OVER THE UPPER MID WEST. THIS WILL KEEP
FAIR COOL WEATHER OVER THE REGION...BUT IT IS NOT OUT OF THE
QUESTION THAT A SUBTLE SHORTWAVE WILL ROTATE THROUGH THE BASE OF THE
TROUGH AND TOUCH OFF SOME ISOLATED SHOWERS. PAST RUNS OF THE ECMWF
HAD BEEN SUGGESTING THIS...BUT THE 00Z RUN WAS GENERALLY `DRY` AS
WAS THE MEDIUM RANGE GFS.
DAYTIME HIGHS SUNDAY AND MONDAY WILL RANGE FROM THE UPPER 60S ACROSS
THE ELEVATED TERRAIN TO THE MID 70S ACROSS THE LAKE PLAINS...WHILE
OVERNIGHT LOWS WILL LARGELY BE IN THE 50S. WITHOUT A CONTINUED FEED
OF COOL AIR FROM THE NORTH...OUR AUTUMN LIKE AIRMASS WILL MODIFY SO
THAT WE CAN ANTICIPATE TEMPERATURES TO BE SOME 5 DEG F HIGHER BY
TUESDAY.
LOOKING FURTHER DOWN THE ROAD...A LOW AMPLITUDE PACIFIC FLOW SHOULD
DOMINATE THE CONUS FOR THE LATTER PART OF NEXT WEEK WITH A RETURN TO
ABOVE NORMAL TEMPERATURES.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
VFR ALL SITES THROUGH THIS EVENING WITH SOUTHERN TIER SEEING SOME
IFR OR LOWER FOG LATE TONIGHT MAINLY ACROSS THE VALLEYS. RADAR IS
CLEAR THIS AFTERNOON AT ALL TAF SITES WITH JUST A SLIGHT CHANCE OF A
SHOWER. MAIN IMPACT IS JUST ENHANCED TCU THIS AFTERNOON WITH LIMITED
SHOWERS. SOME TSRA IS OBSERVED WEST OF LAKE ONTARIO BUT HIGH-RES
GUIDANCE INDICATES THIS SHOULD FALL APART BEFORE REACHING WNY WITH
THE LOST OF HEATING. HIGH PRESSURE AND DRIER AIR WILL BUILD INTO THE
REGION TONIGHT WITH CIGS SCATTERING OUT. WITH THE CLEARING SKIES AND
LIGHT WINDS...SOME VALLEY FOG WILL BE POSSIBLE ACROSS THE SOUTHERN
TIER LATE. HIGH PRESSURE RIDGED OVER THE REGION ON THURSDAY WILL
RESULT MAINLY CLEAR SKIES AND SOUTHWEST WINDS.
OUTLOOK...
THURSDAY NIGHT AND FRIDAY...A PERIOD OF SHOWERS/THUNDERSTORMS WITH
ASSOCIATED MVFR...OTHERWISE VFR.
SATURDAY...POSSIBLE MVFR/IFR FOG EARLY OTHERWISE VFR.
SUNDAY...VFR.
MONDAY...CHANCE OF SHOWERS/TSTRMS. MAINLY VFR.
&&
.MARINE...
WINDS AND WAVES WILL REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA
THROUGH THURSDAY WITH FAIR WEATHER. BUFFALO RADAR SHOWS SOME SHOWERS
AND THUNDERSTORMS NORTH OF LAKE ERIE BUT EXPECT WILL DISSIPATE
BEFORE ARRIVING TO WNY. NO IMPACTS FOR THE NEARSHORES. MOSTLY SUNNY
SKIES THURSDAY WITH LIGHT SOUTHWEST WINDS AS SURFACE RIDGING SHIFTS
OVER THE REGION.
THURSDAY NIGHT AND FRIDAY...A COLD FRONT WILL CROSS THE LOWER LAKES
ALONG WITH THE LIKELIHOOD OF ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS...SOME OF WHICH COULD PRODUCE LOCALLY GUSTY WINDS.
BEHIND THE FRONT...A BRISK WESTERLY FLOW OF COOLER AIR WILL SET UP
ACROSS LAKE ONTARIO ON FRIDAY...WITH WINDS AND WAVES POTENTIALLY
REACHING ADVISORY CRITERIA.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...WEST
NEAR TERM...JJR/SMITH
SHORT TERM...RSH
LONG TERM...RSH
AVIATION...SMITH
MARINE...JJR/SMITH
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
236 PM EDT WED AUG 15 2012
.SYNOPSIS...
SHOWERS ALONG WITH ISOLATED THUNDERSTORMS WILL CONTINUE TODAY AHEAD
OF AN UPPER LEVEL TROUGH. HIGH PRESSURE WILL BUILD OVER CENTRAL NEW
YORK AND NORTHEAST PENNSYLVANIA FOR THURSDAY...LEADING TO A DRY AND
SUNNY DAY WITH HIGH TEMPERATURES INTO THE 80S. A COLD FRONT WILL
RACE THROUGH ON FRIDAY WITH ANOTHER CHANCE FOR SHOWERS AND
THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED AT 1030 AM... LATEST ANALYSIS SHOWS WEAK LOW PRESSURE OVER
NJ WITH LIGHT NNW FLOW ACROSS NE PA AND CENTRAL NY. LOW CLOUDS
FROM MOISTURE LEFT OVER FROM YESTERDAY`S CONVECTION STILL COVERS
MUCH OF THE AREA... WITH THE EXCEPTION OF THE FAR SOUTHEAST ALONG
THE DELAWARE RIVER IN PA WHERE SKIES ARE CLEAR... AND ALSO OVER
THE NORTHERN FINGER LAKES WERE BREAKS ARE BEGINNING TO DEVELOP.
MODELS STILL DEVELOP SOME MODEST INSTABILITY THIS AFTERNOON WITH
LATEST RUC CAPES STILL APPROACHING 1000 J/KG AT MANY LOCATIONS.
WITH LIGHT WINDS EXPECT SHOWERS THAT DEVELOP WILL BE OF THE PULSE
VARIETY WITH A FEW OF THE BIGGER STORMS POSSIBLY APPROACHING
SEVERE LIMITS IN THE SOUTHEAST WHERE THE MOST HEATING WILL OCCUR.
PREVIOUS DISCUSSION BELOW.
UPDATED AT 415 AM...HV LOWERED POPS DRAMATICALLY ACRS THE TWIN
TIERS AS SHOWERS AND TSTMS ARE FINALLY WANING. WILL KEEP AN EYE ON
PATCHY FOG DVLPMNT LATER THIS MRNG.
PREV DISCUSSION...
SHOWERS AND TSTMS CONTINUE TO AFFECT THE TWIN TIERS. UL TROF CONT TO
SWING ACRS NERN HALF OF THE U.S. WITH MOISTURE BEING PUMPED NWRD INTO
THE AREA. THIS COUPLED WITH WK SFC BNDRYS STILL LINGERING IN THE
VICINITY WL CONT SHOWERS AND TSTMS THRU APPROX 09Z AND HV UPPED POPS
TO LKLY-CATEGORICAL FIRST SVRL HRS OF THE NR TERM. LARGE AREA OF
CONVECTION PARKED ACRS SERN PA DOES NOT APPEAR TO BE IMPACTING
STORMS OVR OUR CWA AS THERE APPEARS TO BE CONSIDERABLE MOISTURE
AVAILABLE.
MAIN QUESTION IS WHEN CONVECTION WILL END THIS MRNG AND IF CLDS WILL
BE ABLE TO CLEAR. THIS MAY SET THE STAGE FOR LOCALLY DENSE VALLEY
FOG THIS MRNG AND WL KEEP A CLOSE EYE ON THIS.
AS FOR THIS AFTN GOES...H5 TROF PROGGED TO SWING THRU TDA AND
PUSHING EAST OF FA LATER THIS EVNG. WITH THIS FEATURE EXPECTED TO
AFFECT AREA WL KEEP SCTD CONVECTION MENTION IN TDA. TEMPS WL TOP OUT
IN THE U70S TO NR 80 UNLESS SOME SUN CAN BREAK THRU IN MOIST
AIRMASS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
CDFNT MVS THRU LATE TONIGHT WITH TEMPS BY THUR MRNG DROPPING INTO
THE 50S..MORE SEASONAL FOR THIS TIME OF YR. EXPECT LOCALLY DENSE FOG
TO DVLP LATE TONIGHT AS SKIES CLR AND WINDS DECOUPLE UNDER HIPRES.
THURSDAY WL FEATURE SUNNY SKIES UNDER S/WV RIDGING AND AFTN MAXES
WELL INTO THE 80S. THIS WILL HELP PRIME THE PUMP FOR IMPENDING CDFNT
MVG THRU ON FRIDAY.
SKIES WL BEGIN TO CLD OVR ON FRI MRNG FM WEST TO EAST IN CONJUNCTION
WITH SFC BNDRY APPCHG ALONG WITH UL TROF. TIMING OF CDFNT APPEARS TO
HV SLOWED DOWN WHEN COMPARING 00Z NAM TO 18Z RUN THO IT QUICKLY
CATCHES UP BY FRI AFTN. TIMING LOOKS TO BE FAIRLY IDEAL
(INSTABILITY-WISE) FOR SVR WX POTENTIAL WITH MLCAPES ARND 1000 J/KG
PER BUFKIT SNDGS ACRS CNTRL NY AND DOWN INTO NEPA. LI/S GNRLY RANGE
FM -3 TO -5 WITH AREA IN RRQ OF UL SPEED MAX.
ONLY FLY IN THE OINTMENT WILL BE TIMING OF WIND SHEAR POTENTIAL. H8
LLJ LOOKS TO RANGE FM 25-30KTS FRI AFTN ALONG WITH 0-6KM BULK SHEAR
VALUES INCRSG TO 35 KTS DRG THE EVNG HRS...MAINLY AFTER SUNSET.
TIMING OF THESE PARAMETERS LOOK TO BE OFF FM BEST INSTABILITY ALONG
WITH MAX HTG. WL CONTINUE IDEA OF SVR WX POTENTIAL IN THE HWO BUT
SVRL ITEMS APPEAR TO BE DISJOINTED REGARDING SLAM-DUNK SVR WX.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
XTNDD PD STARTS WITH A SHARP TROF OVER THE CNTRL GREAT LAKES MVG
EWRD. WITH HTG TROF SHD KICK OFF SOME SCT CONV SUN AFTN AND AGAIN
ON MON WITH WEAK SHRT WV ROTATING THRU AND THE GNRL INSTABILITY
CAUSED BY THE LWRD HGTS. TUE HAS A BETTER CHANCE OF BEING DRY AS
THE UPR HGTS BEGIN TO RISE AND WEAK SFC HIPRES BLDS IN.
MDL GUID IN RELATIVELY GOOD AGREEMENT FOR THE PD AND SHOW AFTN
MAXES SLGTLY BLO NRML FOR THE PD WITH THE TROF IN PLACE. THIS
BRINGS A GOOD CONFIDENCE IN THE TEMP FCST FOR THE PD.
MDL POP GUID ALSO IN RSNBL AGREEMENT AND ARE IN THE CHANCE OF SLGT
CHANCE THRU TUE.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
WEAK FLOW AND PLENTIFUL LL MOISTURE HAS ALLOWED FOR SOME SLOW MVG
SHWRS THIS AFTN. MAIN CONCENTRATION OF SHWRS SHD BE TO THE SE AND
EAST OF BGM...WHERE A WEAK FNTL BNDRY IS DROPPING EAST. HAVE CONTD
TO INCLUDE THE CHANCE OF TRWS IN AVP WITH BRIEF MVFR VSBY PSBL.
OTRW...SLOW CLRG SHD CONT THIS AFTN INTO THE EVE. WET GND AND LGT
WINDS WILL CONTRIBUTE TO FOG OVRNGT...ESP AT ELM AND BGM WHERE
LIFR VSBY AND CIGS PSBL BEFORE DAYBRK. ONCE AGAIN...XPCT SLOW CLRG
TO VFR CONDS FOR THU.
OUTLOOK...
THU AFTN-FRI AM...MAINLY VFR.
FRI AFTN/EVE...MVFR IN SHOWERS/TSRA POSSIBLE.
SAT/SUN...VFR...XCPT FOR MRNG FOG.
MON...MVFR PSBL IN AFTN SHWRS/TRWS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...PVN
NEAR TERM...MSE/PVN
SHORT TERM...PVN
LONG TERM...DGM
AVIATION...DGM/SLI
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
146 PM EDT WED AUG 15 2012
.SYNOPSIS...
SHOWERS ALONG WITH ISOLATED THUNDERSTORMS WILL CONTINUE TODAY AHEAD
OF AN UPPER LEVEL TROUGH. HIGH PRESSURE WILL BUILD OVER CENTRAL NEW
YORK AND NORTHEAST PENNSYLVANIA FOR THURSDAY...LEADING TO A DRY AND
SUNNY DAY WITH HIGH TEMPERATURES INTO THE 80S. A COLD FRONT WILL
RACE THROUGH ON FRIDAY WITH ANOTHER CHANCE FOR SHOWERS AND
THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED AT 1030 AM... LATEST ANALYSIS SHOWS WEAK LOW PRESSURE OVER
NJ WITH LIGHT NNW FLOW ACROSS NE PA AND CENTRAL NY. LOW CLOUDS
FROM MOISTURE LEFT OVER FROM YESTERDAY`S CONVECTION STILL COVERS
MUCH OF THE AREA... WITH THE EXCEPTION OF THE FAR SOUTHEAST ALONG
THE DELAWARE RIVER IN PA WHERE SKIES ARE CLEAR... AND ALSO OVER
THE NORTHERN FINGER LAKES WERE BREAKS ARE BEGINNING TO DEVELOP.
MODELS STILL DEVELOP SOME MODEST INSTABILITY THIS AFTERNOON WITH
LATEST RUC CAPES STILL APPROACHING 1000 J/KG AT MANY LOCATIONS.
WITH LIGHT WINDS EXPECT SHOWERS THAT DEVELOP WILL BE OF THE PULSE
VARIETY WITH A FEW OF THE BIGGER STORMS POSSIBLY APPROACHING
SEVERE LIMITS IN THE SOUTHEAST WHERE THE MOST HEATING WILL OCCUR.
PREVIOUS DISCUSSION BELOW.
UPDATED AT 415 AM...HV LOWERED POPS DRAMATICALLY ACRS THE TWIN
TIERS AS SHOWERS AND TSTMS ARE FINALLY WANING. WILL KEEP AN EYE ON
PATCHY FOG DVLPMNT LATER THIS MRNG.
PREV DISCUSSION...
SHOWERS AND TSTMS CONTINUE TO AFFECT THE TWIN TIERS. UL TROF CONT TO
SWING ACRS NERN HALF OF THE U.S. WITH MOISTURE BEING PUMPED NWRD INTO
THE AREA. THIS COUPLED WITH WK SFC BNDRYS STILL LINGERING IN THE
VICINITY WL CONT SHOWERS AND TSTMS THRU APPROX 09Z AND HV UPPED POPS
TO LKLY-CATEGORICAL FIRST SVRL HRS OF THE NR TERM. LARGE AREA OF
CONVECTION PARKED ACRS SERN PA DOES NOT APPEAR TO BE IMPACTING
STORMS OVR OUR CWA AS THERE APPEARS TO BE CONSIDERABLE MOISTURE
AVAILABLE.
MAIN QUESTION IS WHEN CONVECTION WILL END THIS MRNG AND IF CLDS WILL
BE ABLE TO CLEAR. THIS MAY SET THE STAGE FOR LOCALLY DENSE VALLEY
FOG THIS MRNG AND WL KEEP A CLOSE EYE ON THIS.
AS FOR THIS AFTN GOES...H5 TROF PROGGED TO SWING THRU TDA AND
PUSHING EAST OF FA LATER THIS EVNG. WITH THIS FEATURE EXPECTED TO
AFFECT AREA WL KEEP SCTD CONVECTION MENTION IN TDA. TEMPS WL TOP OUT
IN THE U70S TO NR 80 UNLESS SOME SUN CAN BREAK THRU IN MOIST
AIRMASS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
CDFNT MVS THRU LATE TONIGHT WITH TEMPS BY THUR MRNG DROPPING INTO
THE 50S..MORE SEASONAL FOR THIS TIME OF YR. EXPECT LOCALLY DENSE FOG
TO DVLP LATE TONIGHT AS SKIES CLR AND WINDS DECOUPLE UNDER HIPRES.
THURSDAY WL FEATURE SUNNY SKIES UNDER S/WV RIDGING AND AFTN MAXES
WELL INTO THE 80S. THIS WILL HELP PRIME THE PUMP FOR IMPENDING CDFNT
MVG THRU ON FRIDAY.
SKIES WL BEGIN TO CLD OVR ON FRI MRNG FM WEST TO EAST IN CONJUNCTION
WITH SFC BNDRY APPCHG ALONG WITH UL TROF. TIMING OF CDFNT APPEARS TO
HV SLOWED DOWN WHEN COMPARING 00Z NAM TO 18Z RUN THO IT QUICKLY
CATCHES UP BY FRI AFTN. TIMING LOOKS TO BE FAIRLY IDEAL
(INSTABILITY-WISE) FOR SVR WX POTENTIAL WITH MLCAPES ARND 1000 J/KG
PER BUFKIT SNDGS ACRS CNTRL NY AND DOWN INTO NEPA. LI/S GNRLY RANGE
FM -3 TO -5 WITH AREA IN RRQ OF UL SPEED MAX.
ONLY FLY IN THE OINTMENT WILL BE TIMING OF WIND SHEAR POTENTIAL. H8
LLJ LOOKS TO RANGE FM 25-30KTS FRI AFTN ALONG WITH 0-6KM BULK SHEAR
VALUES INCRSG TO 35 KTS DRG THE EVNG HRS...MAINLY AFTER SUNSET.
TIMING OF THESE PARAMETERS LOOK TO BE OFF FM BEST INSTABILITY ALONG
WITH MAX HTG. WL CONTINUE IDEA OF SVR WX POTENTIAL IN THE HWO BUT
SVRL ITEMS APPEAR TO BE DISJOINTED REGARDING SLAM-DUNK SVR WX.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
2 PM UPDATE...
WE WILL START OFF THE EXTENDED PERIOD UNSETTLED WITH A TREND
TOWARD DRIER BUT COOLER WEATHER OVER THE WEEKEND. BEST SHOT AT
PRECIPITATION IN THIS PERIOD WILL COME FRIDAY NIGHT WITH A FRONT
MOVING THROUGH. THE 12Z GFS AND CANADIAN ARE FASTER WITH THE
FRONT...DRYING US OUT BY 12Z SATURDAY. THE 0Z EURO IS MUCH
SLOWER AND ACTUALLY SLOWER THAN THE PREVIOUS RUNS OF THIS MODEL.
FOR NOW WILL LEAVE IN CHANCE POPS OVER THE FAR SOUTHEAST THROUGH
EARLY SATURDAY MORNING. WE MAY BE ABLE TO YANK THESE THOUGH IF THE
12Z EURO COMES IN FASTER...MORE IN LINE WITH THE OTHER LONG RANGE GUIDANCE.
WE SHOULD SEE A PERIOD OF DRY WEATHER FOR THE REST OF SATURDAY
INTO MOST OF SUNDAY BEFORE WE BEGIN TO SEE THE INFLUENCE OF A
DIGGING H5 TROF OVER THE OHIO VALLEY. BOTH THE GFS AND CANADIAN
ARE A BIT MORE AGGRESSIVE IN SENDING MOISTURE ARE WAY BY LATE
SUNDAY...WHICH MAY BE ENOUGH WITH FALLING H5 HEIGHTS FOR SOME
ISOLATED SHOWERS ESPECIALLY WEST OF I-81. STILL FEEL THE BETTER THREAT
FOR CONVECTIVE SHOWERS WITH THE UPPER LEVEL TROF WILL INCREASE
THROUGH MONDAY...BEFORE REACHING A PEAK TUESDAY WITH THE TROF AXIS
MOVING THROUGH. THE BIGGER STORY THIS WEEKEND WILL LIKELY BE THE
TEMPERATURES AS 850 TEMPS REMAIN IN THE SINGLE DIGITS...WHICH WILL
KEEP HIGHS IN THE LOWER TO MIDDLE 70S. PERHAPS A SIGN FALL IS NOT
TOO FAR AROUND THE CORNER.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
WEAK FLOW AND PLENTIFUL LL MOISTURE HAS ALLOWED FOR SOME SLOW MVG
SHWRS THIS AFTN. MAIN CONCENTRATION OF SHWRS SHD BE TO THE SE AND
EAST OF BGM...WHERE A WEAK FNTL BNDRY IS DROPPING EAST. HAVE CONTD
TO INCLUDE THE CHANCE OF TRWS IN AVP WITH BRIEF MVFR VSBY PSBL.
OTRW...SLOW CLRG SHD CONT THIS AFTN INTO THE EVE. WET GND AND LGT
WINDS WILL CONTRIBUTE TO FOG OVRNGT...ESP AT ELM AND BGM WHERE
LIFR VSBY AND CIGS PSBL BEFORE DAYBRK. ONCE AGAIN...XPCT SLOW CLRG
TO VFR CONDS FOR THU.
OUTLOOK...
THU AFTN-FRI AM...MAINLY VFR.
FRI AFTN/EVE...MVFR IN SHOWERS/TSRA POSSIBLE.
SAT/SUN...VFR...XCPT FOR MRNG FOG.
MON...MVFR PSBL IN AFTN SHWRS/TRWS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...PVN
NEAR TERM...MSE/PVN
SHORT TERM...PVN
LONG TERM...HEDEN
AVIATION...DGM/SLI
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1232 PM EDT WED AUG 15 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH TODAY AND LINGERS THROUGH
FRIDAY. A COLD FRONT IS EXPECTED TO MOVE ACROSS THE REGION LATE
FRIDAY AND STALLS JUST SOUTH OF OUR AREA THROUGH THE EARLY PART OF
NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AT 1630 UTC...STILL LOOKS LIKE SCATTERED CONVECTION WILL AFFECT
MAINLY THE NORTHERN MOUNTAINS...SE THROUGH THE NC PIEDMONT THIS
AFTERNOON BASED ON LATEST RADAR AND MODEL FORECASTS. MADE SOME MINOR
ADJUSTMENTS TO POP FIELD FOR TIMING. CLOUDS HOLDING TEMPS IN CHECK
FOR NOW...SO HAVE ADJUSTED TEMP TRACE AMD LOWERED MAX TEMPS A COUPLE
DEGREES. CHANCES FOR PRECIP WILL END AFTER 00Z AS UPPER SHORT
WAVE/SFC FRONT EXIT TO THE EAST.
ANOTHER CONCERN IS THE SEVERE THREAT. THE NAM AND RAP ARE
FORECASTING SOME VERY HEALTHY SBCAPES OVER THE NC PIEDMONT AND
EASTERN UPSTATE THIS AFTERNOON ON THE ORDER OF 2000J/KG. ALSO...BULK
SHEAR WILL BE ON THE ORDER OF 30-40KTS. HENCE...A FEW SEVERE STORMS
ARE POSSIBLE OVER THE EASTERN PART OF THE FORECAST AREA.
PREVIOUS DISCUSSION:
AT 300 AM EDT WEDNESDAY...AN MEAN UPPER TROUGH WILL REMAIN IN PLACE
FROM THE GREAT LAKES TO THE NE GULF OF MEXICO TODAY AND TONIGHT. A
WELL DEFINED SHORTWAVE WILL MOVE TROUGH THIS TROUGH EARLY TODAY...
WHILE AN ASSOCIATED SURFACE COLD FRONT CROSSES THE OUR AREA. LOW
LEVEL MOISTURE IS EXPECTED TO INCREASE AHEAD OF THE FRONT...AND POPS
HAVE BEEN RAISED AT MIDDAY AS THE FRONT AND SHORTWAVE PASS BY.
INSTABILITY AND SHEAR APPEAR SUFFICIENT FOR LARGE HAIL AND DAMAGING
WIND...WHICH WILL BE MENTIONED IN THE HAZARDOUS WEATHER OUTLOOK. QPF
IS EXPECTED TO BE RATHER LIMITED AS STORMS WILL BE MOVING...AND WITH
A FEW RAIN FREE DAYS...MOST OF THE AREA SHOULD BE SPARED FROM
FLOODING. MAXIMUM TEMPERATURES WILL BE SLIGHTLY BELOW NORMAL.
FRONTAL PASSAGE LATE THIS AFTERNOON WILL BE FOLLOWED BY DRYING THIS
EVENING. MINIMUM TEMPERATURES WILL BE A COUPLE OF CATEGORIES BELOW
NORMAL.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM EDT WEDNESDAY...ZONAL FLOW DEVELOPS ON THURSDAY AS THE
UPPER TROUGH MOVES OFF TO THE EAST. SURFACE HIGH PRESSURE IS
EXPECTED TO BUILD IN FROM THE NORTH PROVIDING DRY WEATHER AND NEAR
NORMAL TEMPERATURES ON THURSDAY. AFTERNOON HIGHS WILL BE IN THE
UPPER 80S OVER THE PIEDMONT WITH MID 70S TO LOW 80S IN THE HIGHER
TERRAIN. HEIGHTS FALL FRIDAY AS ANOTHER UPPER TROUGH DIVE TOWARD THE
AREA. THIS WILL PUSH A COLD FRONT FROM THE OH VALLEY TO THE
APPALACHIANS BY LATE FRIDAY. EXPECT INSTABILITY TO RETURN WITH
MOISTENING LOW LEVELS AND COOLING MID LEVELS. BEST CHANCE FOR
PRECIPITATION WILL BE OVER THE BLUE RIDGE WHERE MOISTURE AND UPPER
FORCING ARE HIGHER...BUT SCT CONVECTION SHOULD DEVELOP ALL AREAS BY
LATE EVENING/NIGHT. TEMPERATURES WILL BE NEAR NORMAL ON FRIDAY AS
WELL.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 1140 AM WEDNESDAY...THE MEDIUM RANGE GUIDANCE IS STILL IN GOOD
AGREEMENT THAT A LONG WAVE UPPER TROUGH WILL DEVELOP OVER THE
EASTERN CONUS SUN AND REMAIN IN PLACE THRU TUE. HEIGHTS RISE WED
AS THE TROF AXIS MOVES EAST AND ZONAL FLOW DEVELOPS OVER THE SERN
US. AT THE SURFACE...A FRONTAL BOUNDARY REMAINS STALLED TO OUR SOUTH
AND EAST SUN THRU TUE AS A SERIES OF LOW PRESSURE WAVES MOVE WEST TO
EAST ALONG THE FRONT. THE FRONT MOVES OFFSHORE OR DISSIPATES WED
WITH A MOIST SLY FLOW DEVELOPING OVER THE AREA. THE CANADIAN KEEPS
THE FRONT CLOSER TO OUR CWFA...THE ECMWF IS CLOSER TO THE COAST WITH
THE GFS IN THE MIDDLE. THE CANADIAN ALSO HAS MUCH STRONGER WAVES
MOVING ALONG THE FRONT THAT THE OTHER TWO MODELS. SINCE THE CANADIAN
APPEARS OVERDONE...HAVE TRENDED TOWARD THE GFS/ECMWF WITH A SLIGHT
EDGE TO THE ECMWF. THIS MEANS SCT GENERALLY DIURNAL POP EACH DAY...
WITH HIGHER POP AND LESS OF A DIURNAL TREND SUNDAY WHEN THE FRONT
AND ANY WAVES AND MOISTURE ARE CLOSER TO THE AREA. TUE COULD BE THE
DRIEST DAY WITH THE FRONT AND MOISTURE FARTHER EAST AND SOUTH. WED
WILL SEE A RETURN TO A MORE TYPICAL SCT AFT/EVE TSRA REGIME. TEMPS
WILL BE NEARLY STEADY BELOW NORMAL THRU THE PERIOD.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AT KCLT...MAIN CONCERN IN THE NEAR TERM IS WHETHER ANY CONVECTION
WILL AFFECT THE AIRFIELD THIS AFTERNOON ASSOCIATED WITH A WEAK COLD
FRONT AND PASSING UPPER WAVE. MESO MODELS CONTINUE TO ADVERTISE SCT
TSRA MOVING NEAR THE AIRFIELD IN THE 18Z-20Z TIMEFRAME...SO WILL
CONTINME THE TEMPO FOR TSRA FOR THAT PERIOD. OTHERWISE...LIGHT SW
WINDS WILL GRADUALLY SHIFT NW BY 20Z. CLOUDS WILL SCATTERD BY 00Z
BEHIND THE FRONT AND THEN ESSENTIALLY SKC FOR THE REMAINDER OF THE
TAF PERIOD.
ELSEWHERE...SCATTERD CONVECTION ASSOCIATED WITH A WEAK COLD FRONT
AND PASSIGN UPPER WAVE IS EXPECTED TO AFFECT ONLY THE NC AIRFIELDS.
WIL ADVERTISE A TEMPO AT KHKY 18Z-20Z AND VCTS AT KAVL TIL 19Z.
OTHERWISE...VFR CEILINGS WILL SCT ALL AREAS BY 00Z AND THEN
GENERALLY SKC. MOUNTAIN VALLEY FOG IS EXPECTED LATE TONIGHT
PRODUCIGN A PERIOD OF LIFT AT KAVL IN THE 10Z-13Z TIMEFRAME.
ALSO...A BRIEF PERIOD OF MVFR FOG POSSIBLE AT KAND AND KHKY.
OUTLOOK...HIGH PRESSURE WILL PRODUCE VFR CONDITIONS THROUGH FRIDAY
MORNING. A COLD FRONT WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS
THROUGH AREA FRIDAY AFTENROON INTO FRI NIGHT. SAT LOOKS LIKE IT
SHOULD BE GENERALLY DRY...BUT THE FRONT WILL PUSH NORTH INTLO THE
AREA ON SUN PRODUCING MORE SHOWERS AND THUNDERSTORMS.
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...JOH
NEAR TERM...LG
SHORT TERM...JOH
LONG TERM...JOH
AVIATION...JAT
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
313 PM CDT WED AUG 15 2012
.SHORT TERM...
WE HAVE SOME MIXED SIGNALS REGARDING TSTM CHANCES LATE THIS
AFTERNOON AND EVENING. ON ONE HAND...LOW MOISTURE HAS INCREASED
MARKEDLY OVER YESTERDAY AND WE REMAIN UNDERNEATH A WEST-EAST MID-LVL
MOISTURE AXIS AS WELL. ON THE OTHER HAND...THE MOISTURE HAS DELAYED
HEATING AND THE AREA WAS STILL CAPPED AS OF 2 PM. NW FLOW CONTINUES
ALOFT AND WATER VAPOR IMAGERY SHOWS THE NEXT SHORTWAVE MOVING INTO
NRN NM AT THIS TIME....WHICH IS HELPING TO INITIATE STORMS ALL ALONG
THE NEW MEXICO MTNS. THERE IS ALSO SOME CU DEVELOPMENT IN THE
EAST TO SOUTH-CENTRAL TX PANHANDLE ALONG A SFC TROUGH AND AS THE CAP
WEAKENS WE COULD SEE SOME STORMS DEVELOP ALONG THIS TROUGH INTO
THE FAR SRN PANHANDLE...POSSIBLY SWISHER AND BRISCOE COUNTIES.
FINALLY...WE HAVE ANOTHER WEAK SFC TROUGH NEAR THE TX-NM BORDER
WHICH COULD ALSO BE THE FOCUS FOR SOME STORM DEVELOPMENT WEST OF
HIGHWAY 214. SO WITH ALL THIS...WE HAVE A SLGT CHANCE GOING ACROSS
THE ENTIRE FA THIS AFTERNOON FOR THE POSSIBILITY OF SOME LOCAL
DEVELOPMENT. BUT WE EXPECT THE MAIN SHOW SO TO SPEAK TO BE LATER
THIS EVENING AS A BROKEN LINE/LOOSE COMPLEX OF STORMS MOVES
ROUGHLY E-SEWD OUT OF EASTERN NEW MEXICO....ACROSS THE SPLNS AND
POSSIBLY INTO THE ROLLING PLAINS TONIGHT. THE HRRR HAS BEEN RATHER
CONSISTENT IN THIS DEPICTION...WHILE MUCH OF THE OTHER GUIDANCE
WEAKENS THE ACTIVITY AS IT MOVES EAST. WITH THE UPPER WAVE
PROVIDING SOME BACKGROUND ASCENT AND A 30 TO 40 KT SRLY LLJ WE
CURRENTLY ANTICIPATE THE ACTIVITY MAKING IT AT LEAST INTO THE
CENTRAL SPLNS AND FAR SRN PANHANDLE. DEEP LAYER SHEAR IS CURRENTLY
VERY WEAK...BUT WILL INCREASE THIS EVENING AS THE LLJ CRANKS UP.
INSTABILITY IS ALSO ON THE WEAK TO MODERATE SIDE...HIGHEST
POSITIONED ACROSS THE NORTH. THIS ENVIRONMENT SHOULD SUPPORT THE
THREAT FOR ISOLATED STRONG TO SEVERE WIND GUSTS...WITH THE DEEPER
MOISTURE SUPPORTING STRONGER COLD POOLS AND BETTER RAINFALL
POTENTIAL AS WELL.
WHILE WE SHOULD SEE MOST ACTIVITY WANE IN THE EARLY MORNING
HRS...CONTINUED BROAD UPWARD MOTION IN NW FLOW WILL KEEP A CHANCE OF
SOME ISOLD SHOWERS/TSTMS GOING THROUGH THU MORNING. THEN...A COLD
FRONT IS EXPECTED TO MOVE INTO OUT NRN ZONES LATE THU
MORNING...LIKELY STALLING OUT SOMEWHERE ACROSS THE FAR SRN PANHANDLE
AND NW SPLNS BY MIDDAY OR EARLY AFTERNOON. THIS FRONT SHOULD ABLY SERVE
AS A FOCUS FOR CONVECTIVE INITIATION THURSDAY AFTERNOON. TEMPS MAY
NOT MAKE IT OUT OF THE 80S NORTH OF THE FRONT...WHILE WE EXPECT
HIGHS TO ONCE AGAIN CLIMB INTO THE UPPER 90S TO THE SOUTH OF THE
FRONT. SOUTH OF THE FRONT...THERE WILL BE SOME DOWNBURST POTENTIAL
FROM THE TSTM ACTIVITY....WHILE NORTH OF THE FRONT RAINFALL CHANCES
WILL BE BETTER.
&&
.LONG TERM...
THURSDAY NIGHT THRU SATURDAY...
THE COLD FRONT FROM EARLIER IN THE DAY THURSDAY SHOULD BE STALLED
SOMEWHERE IN THE NORTHERN HALF OF THE CWA BY THURSDAY EVENING. A
GENERAL WEAKNESS IN WINDS ALOFT MAY ACT TO KEEP CONVECTION FOCUSED
RELATIVELY CLOSE TO THE BOUNDARY...OR PERHAPS EVEN NORTH OF THE
FRONT AS ISENTROPIC LIFT IS PROGGED TO AMPLIFY OVERNIGHT AS PER THE
GFS. OPTED TO THEREFORE TIGHTEN THE POP GRADIENT THU NIGHT FROM
NORTH-TO-SOUTH TO REFLECT THIS THINKING. BY FRIDAY...ATTENTION WILL
TURN MORE TO THE SUBTROPICAL PLUME OF MOISTURE CURRENTLY HUGGING THE
WRN COAST OF MEXICO. SOME OF THIS MOISTURE WILL SPREAD NORTH BEFORE
CURLING EASTWARD INTO WEST TX WITHIN A REGION OF LOWERED HEIGHTS
BETWEEN TWO 700MB HIGH CENTERS. PROVIDED THE OSCILLATING FRONTAL
BOUNDARY REMAINS IN THE CWA...LIKELY POPS MAY BE WARRANTED FRI AFTN.
HOWEVER...THIS STRATEGY IS CLOUDED WITH DOUBT AS THE NAM NOW
RETREATS THE BOUNDARY WELL NORTH INTO THE PANHANDLE WHILE PUSHING
HIGHS AREA WIDE INTO THE 90S. NOT YET WILLING TO BREAK CONTINUITY AS
THE NAM`S FRONTAL SOLUTION SEEMS TOO AGGRESSIVE...SO WILL SIDE WITH
THE GFS FAVORING A MORE SOUTHERLY BOUNDARY POSITION. A LULL IN PRECIP
CHANCES MAY VERY WELL DEVELOP FRI EVENING BEFORE DEEPER ASCENT
ARRIVES LATE IN THE NIGHT AND EARLY SAT COURTESY OF A CYCLONICALLY
CURVED JET STREAK DIVING THROUGH THE SOUTHERN GREAT PLAINS. ENHANCED
UPPER DIVERGENCE IN THE EXIT REGION OF THIS 2-CELL MAXIMA WOULD TEND
TO FAVOR THE BEST POPS AFTER MIDNIGHT PRIMARILY ACROSS THE NERN 1/3
OF THE CWA BEFORE EXPANDING OVER THE REMAINDER OF THE AREA SAT
MORNING AS THE BASE OF AN UPPER TROUGH IN NWLY FLOW DRAWS CLOSER.
GIVEN THIS PATTERN IN THE PRESENCE OF PWATS AROUND 1.5 INCHES...WE
COULD CERTAINLY RATCHET POPS INTO THE LIKELY REALM...BUT WILL SETTLE
FOR HIGH CHANCE AT THIS TIME AS THIS WINDOW IS STILL FIVE PERIODS
OUT AND SUBJECT TO CHANGE.
GFS AND ECMWF ARE IN A SURPRISINGLY GOOD AGREEMENT...FOR THE MOST PART...
FOR THE PERIODS SAT THRU TUES. BOTH SEEM TO BE IN AN AGREEMENT WITH
A STALLED FRONT DRAPED FROM THE NC COAST TO THE TX PANHANDLE.
DEWPOINTS WILL BE FAIRLY HIGH...AROUND THE LOWER 60S. THIS COUPLED
WITH UPPER LEVEL DIVERGENCE SHOULD ALLOW WITH SOME PRECIP. I HAVE
BUMPED UP THE POPS JUST A BIT FOR SAT EVENING. THE FRONT SHOULD MOVE
OUT OF THE AREA BY SUN MORNING/EARLY AFTERNOON. HIGHS FOR SAT SHOULD
BE IN THE UPPER 80S. BEYOND THEN THE MODELS VARY IN PRECIP CHANCES.
THE GFS KEEPS PRECIP SOMEWHAT SUPPRESSED AND LOCALIZED OVER THE
PANHANDLE WITH THE INFLUENCE OF AN UPPER LEVEL HIGH WHILE THE 12Z
ECMWF HAS MORE WIDESPREAD COVERAGE DUE TO THE INFLUENCE OF A
SHORTWAVE TROF OVER KS. HAVE KEPT POPS ON THE DOWN LOW AT THE
CURRENT TIME DUE TO UNCERTAINTY BUT DO HAVE A MENTION OF THEM.
LATER IN THE PERIOD AROUND WED THE 12Z GFS AND THE 00Z ECMWF
DIFFER...ESPECIALLY NEAR THE SURFACE. THE GFS IS TRYING TO DEVELOP A
1001 MB LOW IN EASTERN MT WITH A SURFACE TROF DRAPED DOWN TO THE OK
PANHANDLE WED MORNING AND DEEPENS IT TO A 997 MB LOW BY THUR
MORNING...WHILE PUSHING A DRYLINE INTO THE WESTERN PANHANDLE. THE
ECMWF HAS A 1022 MB HIGH OVER MT AND SINKS DOWN TO CO BY THUR
MORNING. HOWEVER...THE NEW 12Z ECMWF HAS COME MORE IN LINE WITH THE
12Z GFS EXCEPT WITH ABOUT A 6 HOUR TIMING DELAY. EITHER WAY...UPPER
LEVEL RIDGING APPEARS TO BE THE NAME OF THE GAME OVER WESTERN TEXAS
AND THAT SHOULD HELP SUPPRESS CONVECTION AND KEEP TEMPS AT THE SURFACE
WARM. ALDRICH
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 65 86 63 85 65 / 30 40 40 40 40
TULIA 67 88 65 86 65 / 30 40 40 40 50
PLAINVIEW 68 90 65 86 66 / 30 30 40 40 50
LEVELLAND 68 93 67 88 67 / 30 30 20 40 40
LUBBOCK 71 93 68 88 68 / 30 30 20 40 40
DENVER CITY 69 94 68 88 68 / 20 20 20 30 30
BROWNFIELD 67 94 68 89 68 / 20 20 20 30 40
CHILDRESS 72 97 69 90 69 / 20 30 40 40 50
SPUR 70 96 70 90 71 / 20 20 20 40 50
ASPERMONT 71 100 72 92 71 / 20 20 20 30 50
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33/51/93
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
617 PM EDT WED AUG 15 2012
.SYNOPSIS...
WEAK HIGH PRESSURE BUILDS IN BEHIND THE DEPARTING SHORTWAVE
TONIGHT. ANOTHER FRONT IMPACTS THE REGION FRIDAY INTO THE WEEKEND
WITH A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS...ESPECIALLY
FRIDAY THROUGH SATURDAY ALONG WITH SEASONABLY MILD TEMPERATURES.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 605 PM EDT WEDNESDAY...
EVENING UPDATE TO LOWER POPS ACROSS THE FAR SOUTH AS DEEPER
CONVECTION ACROSS CENTRAL NC HAS TAKEN BETTER LIFT FARTHER SOUTH.
HOWEVER BUMPED UP COVERAGE A BIT OVER THE NE PER LEFTOVER BAND OF
SHRA/TSRA HEADING DOWN JUST EAST OF THE BLUE RIDGE AND OVER THE NW
JUST AHEAD OF THE ACTUAL DEWPOINT FRONT. APPEARS ENOUGH
INSTABILITY OVER THE NE TO PROMOTE SOME ISOLATED TSRA SO KEPT
MENTION THERE WITH MAINLY SHRA ELSW. THIS BOUNDARY SHOULD PUSH
THRU THE MOUNTAINS OVER THE NEXT FEW HOURS AND THE REST OF THE CWA
THIS EVENING BEHIND THE PASSING UPPER VORT. GOOD SUBSIDENCE BEHIND
THIS FEATURE SHOULD BRING AN END TO ANY REMAINING SHRA WITH LOSS
OF HEATING SO ONLY ISOLATED POPS AT BEST ELSW THIS EVENING.
PREVIOUS DISCUSSION AS OF 325 PM EDT WEDNESDAY...
MAIN SHORTWAVE IS STARTING TO MOVE INTO NRN VA ATTM...WITH PIECES OF
VORT ENERGY OCCURRING ALONG THE BACK EDGE OF THE DEEPER MOISTURE
ACROSS THE SOUTHERN APPALACHIANS INTO SRN WV. STILL APPEARS THE NEAR
TERM MESOSCALE MODELS HOLD CONVECTION THAT IS OCCURRING OVER THE
CENTRAL PORTION OF OUR FORECAST AREA EAST INTO THE PIEDMONT FOR LATE
AFTERNOON. FOLLOWED THE LATEST HRRR EXCEPT SLOWED ITS TIMING DOWN
GIVEN SPEED OF ECHOES ON RADAR BEING SLOWER. ATTM...THINK WILL SEE
THUNDER THREAT PUSHING EAST OF THE BLUE RIDGE SOON....THEN SHOULD
EXPECT SHOWERS TO WIND DOWN AND DISSIPATE AFTER 00Z. SOME CLEARING
AHEAD OF THE VORT LOBE MAY CREATE ENOUGH INSTABILITY THAT A FEW
CELLS COULD BE STRONG TO EVEN SEVERE WITH DAMAGING WINDS POSSIBLE.
CURRENT ANALYSIS SUGGESTS THE GREATEST POTENTIAL FOR THIS WILL BE
SOUTHEAST OF OUR CWA...BUT THOSE AREAS SOUTH OF HIGHWAY 58 FROM
DANVILLE TO SOUTH BOSTON INTO NC MAY BE IN A BETTER ENVIRONMENT FOR
THIS.
AFTER THE ACTIVITY WANES TONIGHT...SKIES SHOULD CLEAR AND SOME FOG
WILL FORM ESPECIALLY WHERE IT RAINED...BUT OVERALL KEPT IT IN THE
MTNS. WILL SEE JUST ENOUGH DRY AIR TO LOWER TEMPS SOME
TONIGHT...CLOSER TO LOCAL MOS WITH MID 50S MTNS TO LOWER 60S
SOUTHEAST.
FLOW WILL BACK AGAIN TO THE SOUTHWEST THU AFTERNOON WITH RISING
HEIGHTS. HIGHS WILL BE WARM ESPECIALLY EAST WITH NEAR 90...WHILE THE
MTNS STAY IN THE LOWER 80S.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
AS OF 350 PM WEDNESDAY...
UPPER AIR PATTERN BECOMES AMPLIFIED FOR THE WEEKS END WITH RIDGE
OVER THE ROCKIES AND TROUGH IN THE EAST. DEEPER TROUGHING IN THE
EAST WILL BE PRECEDED BY WEAK RIDGING THURSDAY NIGHT AND EARLY
FRIDAY AHEAD OF SURFACE COLD FRONT THAT WILL BE MOVING THROUGH THE
OHIO VALLEY. WITH 85H TEMPS +18 DEG C...SHOULD SEE SPIKE IN
TEMPERATURE PRIOR TO FROPA FRIDAY EVENING. CLOUD INCREASE AHEAD OF
FRONT SHOULD KEEP TEMPS IN THE MTNS IN THE 70S...BUT NEAR FULL
INSOLATION EAST OF MTNS WILL LIKELY PERMIT TEMPS TO TEST 90 EAST
OF THE BLUE RIDGE. HIGHEST POPS FRIDAY ANTICIPATED IN THE
MTNS...SHRA/TSRA DEVELOPING IN ADV OF FRONT AND MOVING ACROSS THE CWA
DURING THE LATE AFTERNOON AND EVENING.
MODELS SLOW PROGRESSION OF FRONT AS IT CROSSES THE CWA...THUS CLOUDS
AND PRECIP THREAT MAY LINGER INTO SATURDAY. NOT OVERLY EXCITED
ABOUT INSTABILITY SATURDAY PER LINGERING CLOUD COVER...THUS THINK
ANY PRECIP SATURDAY WOULD BE IN THE FORM OF SHOWERS AND LITTLE OR NO
THUNDER. FRONT IS FCST TO DISSIPATE OVER OR JUST SOUTH OF THE AREA
SATURDAY NIGHT...AMOUNT OF CLEARING DEPENDENT ON FRONTAL REMNANTS.
TEMPERATURES SATURDAY WILL BE TEMPERED BY CLOUD COVER...L-M 70S
MTS...LOWER 80S PIEDMONT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 350 PM WEDNESDAY...
UPPER LEVEL TROUGH SETS UP SHOP OVER THE ERN CONUS FOR NEXT WEEK.
FLOW ALOFT REMAINS CYCLONIC WITH EMBEDDED SHORT WAVE ENERGY HELPING
TO KEEP THE FLOW AMPLIFIED. PRESENCE OF THE TROUGH SUGGESTS TEMPS
WILL RUN BLO MEDIAN. AS FOR PRECIP...A LOT WILL DEPEND ON THE
AMOUNT OF RETURN FLOW THAT CAN DEVELOP AND TIMING OF ANY SHORT WAVE
ENERGY. FOR NOW WILL FOCUS HIGHEST POPS VCNTY OF MTNS WHERE LOW
LEVEL CONVERGENCE WILL BE GREATEST...ALTHOUGH COOLER THAN NORMAL
TEMPS SUGGESTS INSTABILITY WILL BE MAINLY DIURNALLY DRIVEN.
&&
.AVIATION /22Z WEDNESDAY THROUGH MONDAY/...
AS OF 115 PM EDT WEDNESDAY...
GOING WITH SHRA AT BLF/LWB/BCB/ROA IN THE FIRST HOUR WITH NO
THUNDER...AS INSTABILITY LACKING. THE THREAT FOR SUB VFR IS NOT
LONG-LASTING MAYBE AN HOUR WITH THE HEAVIER SHOWERS WHICH WILL
BRING VSBYS DOWN TO 2SM WITH CIGS AROUND 1500-3000FT IN THE MTNS.
WITH THE SHORTWAVE EXITING THIS EVENING...THINK WE WILL SEE
CLEARING SKIES BUT THE DEWPOINTS STAY ELEVATED ENOUGH WHERE FOG
WILL BE AN ISSUE AFTER MIDNIGHT. MODELS SHOW AT LEAST MVFR FOG
ACROSS MOST AREAS AFTER 06Z...WITH LIFR AT LWB/BLF. AT BCB WE MAY
SEE SUB IFR BUT CONFIDENCE NOT HIGH.
HAVE THE FOG CLEARING ACROSS THE AREA BY 14Z THU...AND HIGH
PRESSURE WILL BE IN CONTROL WITH VFR CONDITIONS.
ASIDE FROM SOME LATE NIGHT FOG AT LWB/BCB ANTICIPATE THE NEXT
THREAT FOR SUB VFR TO COME WITH A FRONT FRIDAY INTO SATURDAY. THE
FRONT SLOWS AND LINGERS ACROSS CENTRAL SC NORTHEAST TO THE OUTER
BANKS THROUGH THE WEEKEND SUCH THAT THE THREAT OF SHOWERS MAY
OCCUR IN THE DANVILLE AREA...WIH SOME MVFR POSSIBLE. THE FRONT
WILL BE MOVING SLOWLY EAST BY MONDAY AS HIGH PRESSURE WORKS IN
FROM THE OHIO VALLEY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WP
NEAR TERM...JH/WP
SHORT TERM...PM
LONG TERM...PM
AVIATION...RAB/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
352 PM EDT WED AUG 15 2012
.SYNOPSIS...
WEAK HIGH PRESSURE BUILDS IN BEHIND THE DEPARTING SHORTWAVE
TONIGHT. ANOTHER FRONT IMPACTS THE REGION FRIDAY INTO THE WEEKEND
WITH A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS...ESPECIALLY
FRIDAY THROUGH SATURDAY ALONG WITH SEASONABLY MILD TEMPERATURES.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 325 PM EDT WEDNESDAY...
MAIN SHORTWAVE IS STARTING TO MOVE INTO NRN VA ATTM...WITH PIECES OF
VORT ENERGY OCCURRING ALONG THE BACK EDGE OF THE DEEPER MOISTURE
ACROSS THE SOUTHERN APPALACHIANS INTO SRN WV. STILL APPEARS THE NEAR
TERM MESOSCALE MODELS HOLD CONVECTION THAT IS OCCURRING OVER THE
CENTRAL PORTION OF OUR FORECAST AREA EAST INTO THE PIEDMONT FOR LATE
AFTERNOON. FOLLOWED THE LATEST HRRR EXCEPT SLOWED ITS TIMING DOWN
GIVEN SPEED OF ECHOES ON RADAR BEING SLOWER. ATTM...THINK WILL SEE
THUNDER THREAT PUSHING EAST OF THE BLUE RIDGE SOON....THEN SHOULD
EXPECT SHOWERS TO WIND DOWN AND DISSIPATE AFTER 00Z. SOME CLEARING
AHEAD OF THE VORT LOBE MAY CREATE ENOUGH INSTABILITY THAT A FEW
CELLS COULD BE STRONG TO EVEN SEVERE WITH DAMAGING WINDS POSSIBLE.
CURRENT ANALYSIS SUGGESTS THE GREATEST POTENTIAL FOR THIS WILL BE
SOUTHEAST OF OUR CWA...BUT THOSE AREAS SOUTH OF HIGHWAY 58 FROM
DANVILLE TO SOUTH BOSTON INTO NC MAY BE IN A BETTER ENVIRONMENT FOR
THIS.
AFTER THE ACTIVITY WANES TONIGHT...SKIES SHOULD CLEAR AND SOME FOG
WILL FORM ESPECIALLY WHERE IT RAINED...BUT OVERALL KEPT IT IN THE
MTNS. WILL SEE JUST ENOUGH DRY AIR TO LOWER TEMPS SOME
TONIGHT...CLOSER TO LOCAL MOS WITH MID 50S MTNS TO LOWER 60S
SOUTHEAST.
FLOW WILL BACK AGAIN TO THE SOUTHWEST THU AFTERNOON WITH RISING
HEIGHTS. HIGHS WILL BE WARM ESPECIALLY EAST WITH NEAR 90...WHILE THE
MTNS STAY IN THE LOWER 80S.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
AS OF 350 PM WEDNESDAY...
UPPER AIR PATTERN BECOMES AMPLIFIED FOR THE WEEKS END WITH RIDGE
OVER THE ROCKIES AND TROUGH IN THE EAST. DEEPER TROUGHING IN THE
EAST WILL BE PRECEDED BY WEAK RIDGING THURSDAY NIGHT AND EARLY
FRIDAY AHEAD OF SURFACE COLD FRONT THAT WILL BE MOVING THROUGH THE
OHIO VALLEY. WITH 85H TEMPS +18 DEG C...SHOULD SEE SPIKE IN
TEMPERATURE PRIOR TO FROPA FRIDAY EVENING. CLOUD INCREASE AHEAD OF
FRONT SHOULD KEEP TEMPS IN THE MTNS IN THE 70S...BUT NEAR FULL
INSOLATION EAST OF MTNS WILL LIKELY PERMIT TEMPS TO TEST 90 EAST
OF THE BLUE RIDGE. HIGHEST POPS FRIDAY ANTICIPATED IN THE
MTNS...SHRA/TSRA DEVELOPING IN ADV OF FRONT AND MOVING ACROSS THE CWA
DURING THE LATE AFTERNOON AND EVENING.
MODELS SLOW PROGRESSION OF FRONT AS IT CROSSES THE CWA...THUS CLOUDS
AND PRECIP THREAT MAY LINGER INTO SATURDAY. NOT OVERLY EXCITED
ABOUT INSTABILITY SATURDAY PER LINGERING CLOUD COVER...THUS THINK
ANY PRECIP SATURDAY WOULD BE IN THE FORM OF SHOWERS AND LITTLE OR NO
THUNDER. FRONT IS FCST TO DISSIPATE OVER OR JUST SOUTH OF THE AREA
SATURDAY NIGHT...AMOUNT OF CLEARING DEPENDENT ON FRONTAL REMNANTS.
TEMPERATURES SATURDAY WILL BE TEMPERED BY CLOUD COVER...L-M 70S
MTS...LOWER 80S PIEDMONT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 350 PM WEDNESDAY...
UPPER LEVEL TROUGH SETS UP SHOP OVER THE ERN CONUS FOR NEXT WEEK.
FLOW ALOFT REMAINS CYCLONIC WITH EMBEDDED SHORT WAVE ENERGY HELPING
TO KEEP THE FLOW AMPLIFIED. PRESENCE OF THE TROUGH SUGGESTS TEMPS
WILL RUN BLO MEDIAN. AS FOR PRECIP...A LOT WILL DEPEND ON THE
AMOUNT OF RETURN FLOW THAT CAN DEVELOP AND TIMING OF ANY SHORT WAVE
ENERGY. FOR NOW WILL FOCUS HIGHEST POPS VCNTY OF MTNS WHERE LOW
LEVEL CONVERGENCE WILL BE GREATEST...ALTHOUGH COOLER THAN NORMAL
TEMPS SUGGESTS INSTABILITY WILL BE MAINLY DIURNALLY DRIVEN.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
AS OF 115 PM EDT WEDNESDAY...
GOING WITH SHRA AT BLF/LWB/BCB/ROA IN THE FIRST HOUR WITH NO
THUNDER...AS INSTABILITY LACKING. THE THREAT FOR SUB VFR IS NOT
LONG-LASTING MAYBE AN HOUR WITH THE HEAVIER SHOWERS WHICH WILL
BRING VSBYS DOWN TO 2SM WITH CIGS AROUND 1500-3000FT IN THE MTNS.
WITH THE SHORTWAVE EXITING THIS EVENING...THINK WE WILL SEE
CLEARING SKIES BUT THE DEWPOINTS STAY ELEVATED ENOUGH WHERE FOG
WILL BE AN ISSUE AFTER MIDNIGHT. MODELS SHOW AT LEAST MVFR FOG
ACROSS MOST AREAS AFTER 06Z...WITH LIFR AT LWB/BLF. AT BCB WE MAY
SEE SUB IFR BUT CONFIDENCE NOT HIGH.
HAVE THE FOG CLEARING ACROSS THE AREA BY 14Z THU...AND HIGH
PRESSURE WILL BE IN CONTROL WITH VFR CONDITIONS.
ASIDE FROM SOME LATE NIGHT FOG AT LWB/BCB ANTICIPATE THE NEXT
THREAT FOR SUB VFR TO COME WITH A FRONT FRIDAY INTO SATURDAY. THE
FRONT SLOWS AND LINGERS ACROSS CENTRAL SC NORTHEAST TO THE OUTER
BANKS THROUGH THE WEEKEND SUCH THAT THE THREAT OF SHOWERS MAY
OCCUR IN THE DANVILLE AREA...WIH SOME MVFR POSSIBLE. THE FRONT
WILL BE MOVING SLOWLY EAST BY MONDAY AS HIGH PRESSURE WORKS IN
FROM THE OHIO VALLEY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WP
NEAR TERM...WP
SHORT TERM...PM
LONG TERM...PM
AVIATION...RAB/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
145 PM EDT WED AUG 15 2012
.SYNOPSIS...
AN UPPER TROUGH WILL PASS ACROSS THE AREA THIS AFTERNOON. DRIER
CONDITIONS WILL SPREAD ACROSS THE AREA THURSDAY BEFORE A STRONGER
UPPER TROUGH IMPACTS THE REGION FRIDAY INTO THE WEEKEND WITH A
BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS...ESPECIALLY FRIDAY
THROUGH SATURDAY ALONG WITH SEASONABLY MILD TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 105 PM EDT WEDNESDAY...
THE 13Z HRRR WAS HANDLING THE ENERGY MOVING ACROSS WV AND THE
CONVECTION SITUATED FROM THIS VORT IN WV SOUTH INTO ERN TN. WILL
FOLLOW IT SOME THROUGH MID AFTERNOON WHICH TAKES THE BULK OF
PRECIP ENE THROUGH THE NRV/ROA VALLEYS AND TO LYH AND OUT OF THE
CWA BY 6PM. TO THE SOUTH...THE VORT TAIL SHOULD ALLOW FOR
ISOLATED/SCATTERED SHRA/FEW TSRA. THINK INSTABILITY WILL BE
LIMITED WITH HIGHER THRESHOLDS ACROSS SOUTHSIDE VA/NW NC PIEDMONT
WHERE THUNDER CHANCES WILL REMAIN UNTIL LATE AFTERNOON.
MADE SOME DOWNWARD ADJUSTMENTS AGAIN TO THE TEMPS ESPECIALLY WEST
THOUGH SOME CLEARING BEHIND THE VORT MAY SEND TEMPS UP INTO THE
MID TO UPPER 70S. THE EAST WILL BE GETTING MORE CLOUDS WITH THE
VORT PASSING BY EXCEPT SOUTH OF THE VA/NC BORDER IN WHERE
CU/TCU/CB WILL BE SCT WITH SOME MID/HIGH CLOUDS AT TIMES.
PREVIOUS VALID DISCUSSION...
FOR TONIGHT...SOMEWHAT DRIER AIR WILL ADVECT INTO THE REGION FROM
THE NW BEHIND THIS FIRST SHORT WAVE TROUGH. SKIES WILL CLEAR AFT
00Z FROM WEST TO EAST WITH ANY AFTERNOON UPSLOPE CU/SC DISSIPATING
QUICKLY AND NO INDICATION OF ANY UPSTREAM CI AT THIS POINT.
DEWPOINTS INTO THE MID AND UPPER 50S ACROSS SE WV AND SW VA WILL
ALLOW FAVORABLE VALLEYS TO DROP INTO THE MID AND UPPER 50S
OVERNIGHT...WITH 60S ACROSS THE PIEDMONT AND HIGHER...EXPOSED
ELEVATIONS.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
THIS PERIOD WILL TREND TO A MORE AMPLIFIED PATTERN WITH A DEEP UPPER
TROUGH EVENTUALLY BEING CARVED OUT ACROSS THE EASTERN CONUS. BEFORE
THAT...QUICK WARM ADVECTION PUTS H85 TEMPS TO +18C BY 0Z FRIDAY/8P
THURSDAY. CONSIDERING THAT DEWPOINTS WON`T RISE AS QUICKLY AS THE
TEMPS...RELATIVE HUMIDITY WILL BE RATHER COMFORTABLE ON THURSDAY
WITH DEWPOINTS IN THE 50S NEAR MAX MIXING WITH A LIGHT WESTERLY
WIND. CLOUDS WILL SLOWLY INCREASE ACROSS SE WEST VA THURSDAY
NIGHT...BUT WITH HARDLY ANY CLOUDS...DRY AIR AND NIL WINDS LOW TEMPS
MAY RUN A DEGREE OR TWO BELOW GUIDANCE ACROSS THE PIEDMONT AND
SOUTHSIDE INTO FRIDAY MORNING. THE UPPER SUPPORT TO THE COLD
FRONT...WHICH WILL APPROACH THE REGION LATER FRIDAY AND FRIDAY
NIGHT...PASSES INTO SOUTHEASTERN CANADA. ANY LINE OF STORMS WHICH
FORMS ACROSS THE OHIO VALLEY THUS MAY DWINDLE ACROSS WEST VA. COLUMN
DOESN`T MOISTEN QUICKLY ENOUGH FOR WIDESPREAD SHWS AND STORMS TO
SURVIVE INTO THE PIEDMONT/SOUTHSIDE AND POSSIBLY EVEN THE ROANOKE
VALLEY. THUS...FRIDAY DOESN`T LOOK LIKE THAT BAD OF A DAY...WITH ANY
SHOWERS OR STORMS HOLDING OFF UNTIL LATE DAY SAVE SOUTHEASTERN WEST
VA/NW NC. HIGHEST POPS WILL BE FROM JFZ TO BLF TO WESTERN
GREENBRIER. COLD FRONT GETS LEFT BEHIND BY ITS UPPER SUPPORT PERHAPS
PARKING IT OVER THE NEW RIVER VALLEY ON SATURDAY. THIS SHOULD KEEP
SHOWERS AND STORMS AROUND FOR AT LEAST HALF OF THE DAY ON SATURDAY
AS DISTURBANCES RIDE ALONG IT...WITH SKIES SLOW TO CLEAR...AND A
FEW SHOWERS STILL AROUND SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 110 PM EDT TUESDAY...
TREND THE PAST FEW DAYS HAS BEEN FOR THE FRIDAY COLD FRONTAL PASSAGE
TO LAG A BIT SLOWER. THIS TREND CONTINUES TODAY WITH THE FRONT
SWEEPING THROUGH THE REGION FRIDAY NIGHT. HAVE INCREASED POPS FRIDAY
NIGHT TO ACCOUNT FOR THE GREATEST CHANCE OF PRECIPITATION...AS
COMPARED TO THE SOMEWHAT LOWER CHANCE FRIDAY AFTERNOON. IN FOLLOWING
HPC GUIDANCE...WILL HAVE LOW END LIKELY POPS ACROSS THE FAR WESTERN
PARTS OF THE AREA EARLY FRIDAY NIGHT...WITH HIGH CHANCE POPS IN THE
EAST LATE FRIDAY NIGHT.
WHILE WE WILL SEE THE FRONT HEAD TO OUR SOUTH ON SATURDAY...AND THE
BEGINNINGS OF SURFACE HIGH PRESSURE WORKINGS ITS WAY INTO THE
AREA...A PERSISTENT BROAD TROUGH OF LOW PRESSURE ALOFT WILL REMAIN
ACROSS THE CENTRAL AND EASTERN PARTS OF THE COUNTRY. PERIODIC
SHORTWAVE TROUGHS OF ENERGY ARE PROGGED TO BE WITHIN THIS LARGER
FLOW INTO EARLY NEXT WEEK.
TIMING OF THESE FEATURES WILL BE PROBLEMATIC...AS THEY WILL LIKELY
FLUCTUATE WITH EACH SUCCESSIVE MODEL RUN.
FOR THE SATURDAY THROUGH TUESDAY PORTION OF THE FORECAST...HAVE
WEIGHED OUR SOLUTION HEAVILY ON THE HPC GUIDANCE WHICH GOES HEAVY ON
MAINTAINING LINGER POPS ON THE BACKSIDE OF THE FRONT INTO
SATURDAY...COINCIDENT TO ONE OF THESE WEAKER WAVES ROUNDING THE BASE
OF THE LARGER PARENT TROUGH. OTHER ISOLATED SHOWERS ARE FORECAST
SUNDAY THROUGH TUESDAY.
THE EXISTENCE OF THE UPPER TROUGH PARKED OVER THE REGION WILL YIELD
TEMPERATURES AT OR SLIGHTLY BELOW NORMAL FOR THIS TIME OF THE YEAR.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 115 PM EDT WEDNESDAY...
GOING WITH SHRA AT BLF/LWB/BCB/ROA IN THE FIRST HOUR WITH NO
THUNDER...AS INSTABILITY LACKING. THE THREAT FOR SUB VFR IS NOT
LONG-LASTING MAYBE AN HOUR WITH THE HEAVIER SHOWERS WHICH WILL
BRING VSBYS DOWN TO 2SM WITH CIGS AROUND 1500-3000FT IN THE MTNS.
WITH THE SHORTWAVE EXITING THIS EVENING...THINK WE WILL SEE
CLEARING SKIES BUT THE DEWPOINTS STAY ELEVATED ENOUGH WHERE FOG
WILL BE AN ISSUE AFTER MIDNIGHT. MODELS SHOW AT LEAST MVFR FOG
ACROSS MOST AREAS AFTER 06Z...WITH LIFR AT LWB/BLF. AT BCB WE MAY
SEE SUB IFR BUT CONFIDENCE NOT HIGH.
HAVE THE FOG CLEARING ACROSS THE AREA BY 14Z THU...AND HIGH
PRESSURE WILL BE IN CONTROL WITH VFR CONDITIONS.
ASIDE FROM SOME LATE NIGHT FOG AT LWB/BCB ANTICIPATE THE NEXT
THREAT FOR SUB VFR TO COME WITH A FRONT FRIDAY INTO SATURDAY. THE
FRONT SLOWS AND LINGERS ACROSS CENTRAL SC NORTHEAST TO THE OUTER
BANKS THROUGH THE WEEKEND SUCH THAT THE THREAT OF SHOWERS MAY
OCCUR IN THE DANVILLE AREA...WIH SOME MVFR POSSIBLE. THE FRONT
WILL BE MOVING SLOWLY EAST BY MONDAY AS HIGH PRESSURE WORKS IN
FROM THE OHIO VALLEY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...RAB/WP
NEAR TERM...RAB/WP
SHORT TERM...KM
LONG TERM...DS
AVIATION...RAB/WP
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
241 PM CDT WED AUG 15 2012
.SHORT TERM...TONIGHT AND THURSDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SURFACE HIGH
PRESSURE MOVING TO THE EASTERN GREAT LAKES WHILE SHORTWAVE ENERGY
OVER THE LAKE WINNIPEG REGION IS PUSHING LOW PRESSURE OVER THE
NORTHERN PLAINS. SHOWERS AND THUNDERSTORMS OVER SOUTHEAST MINNESOTA
AND SOUTHWEST WISCONSIN EARLIER THIS MORNING HAVE DISSIPATED LEAVING
ONLY BANDS OF MID AND CLOUDS OVERHEAD IN A WARM ADVECTION REGIME.
ALONG THE FRONT...SHOWERS AND ISOLATED THUNDERSTORMS ARE OCCURRING
OVER NORTH DAKOTA AND NW MINNESOTA. WITH STRONG TO SEVERE STORMS
EXPECTED TO DEVELOP LATER THIS AFTERNOON ALONG THE FRONT...SEVERE
WEATHER CHANCES IS THE MAIN FORECAST CONCERN TONIGHT.
TONIGHT...SHORTWAVE TROUGH OVER LAKE WINNIPEG WILL DRIVE A STRONG
COLD FRONT ACROSS THE NORTHERN MISSISSIPPI VALLEY THIS EVENING AND
INTO CENTRAL WISCONSIN BY LATE TONIGHT. A LINE OF SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE FRONT LATER THIS
AFTERNOON...AND THEN PUSH EAST WITH THE FRONT. TIMING OF THE FRONT
MAY HAVE SLOWED A LITTLE BIT...BUT STILL EXPECT SHOWERS AND
THUNDERSTORMS TO MOVE INTO NORTH-CENTRAL AND CENTRAL WISCONSIN
SHORTLY AFTER MIDNIGHT AND INTO EASTERN WISCONSIN LATE TONIGHT.
THOUGH 0-6KM BULK SHEAR OF 40-45KTS ALONG THE FRONT IS SUFFICIENT
FOR SEVERE WEATHER...ELEVATED INSTABILITY WILL BE SLOWLY DIMINISHING
TONIGHT WITHIN THE AIRMASS AHEAD OF THE FRONT. PROGGED SOUNDINGS
INDICATE RELATIVELY SKINNY CAPE BETWEEN 800 J/KG OVER NORTH-CENTRAL
WISCONSIN TO AROUND 1000 J/KG OVER CENTRAL WISCONSIN. THERE IS A
LITTLE BIT OF A 850MB THETAE RIDGE POKING INTO CENTRAL WISCONSIN
BETWEEN 09-12Z WHICH MAY BE ABLE TO SUSTAIN STORMS BETTER...AND
CONTRIBUTE TO LOW END SEVERE THUNDERSTORM CHANCES. WITH THE SKINNY
CAPE AND DECAYING INSTABILITY...THE HAIL THREAT WILL BE MINIMAL.
BUT WINDS OF 40-45 KTS ALOFT COULD LEAD TO SMALL WIND THREAT OVER
CENTRAL WISCONSIN. ANY DESCENDING WIND WILL HAVE TO FIGHT THROUGH A
SHARP TEMPERATURE INVERSION ABOVE THE BOUNDARY LAYER SO EVEN IF
STRONG STORMS ARE PRESENT...NOT A SURE BET THEY WILL REACH THE
SURFACE. WILL MENTION THE SLIGHTLY HIGHER PROBABILITY OF SEVERE
WEATHER OVER CENTRAL WISCONSIN IN THE HWO. OTHERWISE A WARMER AND
MUGGY NIGHT WITH LOWS MAINLY IN THE 60S.
THURSDAY...THE FRONT WILL SWEEP ACROSS CENTRAL AND NORTHEAST
WISCONSIN DURING THE MORNING HOURS...KEEPING THE THREAT OF SHOWERS
AND STORMS AROUND. WILL LIKELY SEE SOME CLEARING FOR A FEW HOURS
DIRECTLY BEHIND THE FRONT AS A DRY SLOT MOVES NORTHEAST...BUT LOW
LEVEL MOISTURE QUICKLY ROTATES BACK INTO NORTH-CENTRAL AND NORTHEAST
WISCONSIN IN THE AFTERNOON THAT WILL PRODUCE SCT TO BKN CU. HIGH
TEMPS COOLING OFF INTO THE MID 60S NORTH TO MID 70S SOUTH.
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY.
MODELS IN GOOD AGREEMENT FOR THE FIRST PART OF THE FORECAST...WITH
THURSDAY NIGHT AND FRIDAY LOOKING DRY OTHER THAN A FEW SHOWERS OVER
NORTHERN WISCONSIN FRIDAY AFTERNOON. AFTER THAT...MODELS ALL OVER
THE BOARD AS FAR AS PRECIP CHANCES STARTING SATURDAY MORNING AS
AN UPPER LEVEL TROUGH STALLS OVER THE EASTERN CONUS AND CREATES A
BLOCKING-LIKE PATTERN. MAIN FORECAST CHALLENGE FOR THE EXTENDED
WILL BE PRECIP CHANCES SATURDAY THROUGH TUESDAY.
...THURSDAY NIGHT THROUGH FRIDAY NIGHT...
COLD FRONT EXITS WI THURSDAY EVENING. MODELS IN AGREEMENT ON DRY
CONDITIONS STARTING THURSDAY NIGHT THROUGH FRIDAY MID- MORNING.
FRIDAY AFTERNOON EXPECTED TO BE DRY FOR MUCH OF THE CWA EXCEPT
FOR FAR NORTHERN WISCONSIN. MORE MODELS ARE TRENDING TOWARDS SHOWERY
ACTIVITY FRIDAY AFTERNOON OVER FAR NORTHERN WI. SFC HEATING
COUPLED WITH STRONG CAA IN THE MID-LEVELS COULD LEAD TO PRECIP
STARTING AR 18Z FRIDAY ACROSS ALL OF NORTHERN WI. THEREFORE
EXPANDED THE SLIGHT CHANCE POPS FURTHER WEST THAN PREVIOUS
FORECAST FOR FRIDAY AFTERNOON WHERE MID LEVEL TEMPS WILL BE
COLDEST.
AT THIS POINT...CLOUD COVER SHOULD KEEP TEMPS ABOVE LEVELS THAT
WOULD LEAD TO FROST DEVELOPMENT OVER NORTHERN WI FRIDAY NIGHT.
...SATURDAY THROUGH TUESDAY...
UPPER LEVEL TROUGH WILL STALL TO OUR EAST...PUTTING WI IN AN AREA
OF NW FLOW ALOFT. WEATHER OVER THE NEXT FEW DAYS WILL BE A RESULT OF
SHORTWAVES DIGGING THROUGH THE MEAN FLOW. EACH MODEL HANDLES THESE
SHORTWAVES DIFFERENTLY WITH VARYING IDEAS FOR TIMING AND COVERAGE
OF ANY PRECIP. THIS RESULTS IN NUMEROUS PERIODS OF SLIGHT CHANCE POPS
IN THE EXTENDED. WAS ABLE TO KEEP THINGS DRY SATURDAY AFTERNOON IN
SOUTHERN PORTIONS OF THE CWA AS GFS IS THE ONLY MODEL THAT HAS
WIDESPREAD PRECIP AND MODEL CONSENSUS KEEPS ANY SHOWERS THAT DEVELOP
OVER NORTHERN WI. SATURDAY NIGHT SHOULD BE DRY AS WELL ACROSS
ALL OF NORTHEAST WI AS WE LOSE THE DIURNAL HEATING AND PRECIP
SHOULD COME TO THE END. AFTER THAT...TOO MUCH MODEL SPREAD TO MAKE
ANY CHANGES.
TEMPERATURES SHOULD CONTINUE TO BE SLIGHTLY BELOW NORMAL THROUGH
EARLY NEXT WEEK DUE TO STRONG NW FLOW ALOFT. WARMER TEMPERATURES CAN
BE THEN BE EXPECTED TUESDAY AND WEDNESDAY AS THE FLOW TURNS SOUTH
AHEAD OF AN APPROACHING COLD FRONT.
&&
.AVIATION...A WARM FRONT LIFTING NORTHEAST ACROSS THE STATE WILL
BRING ISOLATED SHOWERS TO THE AREA THIS AFTERNOON. COVERAGE WILL BE
TOO SPOTTY TO INCLUDE EXPLICITLY IN THE TAFS. A STRONG COLD FRONT
WILL THEN PROCEED TO MOVE ACROSS THE AREA AFTER MIDNIGHT TONIGHT. A
BAND OF SHOWERS AND THUNDERSTORMS WILL ACCOMPANY THE FRONT AND SOME
STORMS COULD PRODUCE GUSTY WINDS UP TO 45 KTS. LLWS WILL BE
INCREASING AHEAD OF THE FRONT THOUGH WILL DIMINISH ONCE THE FRONT
MOVES THROUGH. SHOWERS WILL COME TO AN END LATE TONIGHT INTO
THURSDAY MORNING...BUT LOWER CIGS AND VSBYS TO MVFR LEVELS ARE
EXPECTED TO BE PRESENT BEHIND THE FRONT FOR SEVERAL HOURS.
CLEARING IS EXPECTED LATE TOMORROW MORNING BEFORE CLOUDS INCREASE
AGAIN FOR THE AFTERNOON.
MPC
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MPC/WOLF