Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/17/12
AREA FORECAST DISCUSSION...UPDATED
NWS TUCSON AZ
520 PM MST THU AUG 16 2012
.SYNOPSIS...INCREASED MOISTURE WILL RESULT IN AN ACTIVE PERIOD OF
MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS THROUGH THIS
WEEKEND. THIS WILL RESULT IN BELOW NORMAL DAYTIME TEMPERATURES.
&&
.DISCUSSION...BASED ON RADAR TRENDS AS WELL AS THE 16/21Z RUC HRRR...
UPDATED FORECAST WAS ISSUED TO REDUCE POPS VERSUS THE PREVIOUS
FORECAST FOR THIS EVENING. HAVE MAINTAINED CHANCE-CATEGORY POPS...
OR SCATTERED COVERAGE OF SHOWERS/TSTMS...MOST SECTIONS THIS EVENING.
HOWEVER...THE LEAST LIKELY AREA FOR MEASURABLE PRECIP APPEARS TO BE
FROM THE TUCSON METRO AREA SEWD INTO WRN/CENTRAL COCHISE COUNTY. RUC
HRRR DEVELOPS SCATTERED TO PERHAPS NUMEROUS SHOWERS/TSTMS GENERALLY
FROM ERN PIMA COUNTY SWD ACROSS SANTA CRUZ COUNTY AROUND 17/0530Z...
1030 PM MST...AND CONVECTIVE ACTIVITY IS PROGGED TO INCREASE THRU
MIDNIGHT. HAVE NOTED THAT THE 16/18Z NAM DEPICTED LATE TONIGHT AND
FRI MORNING AS THE PERIOD FOR ENHANCED PRECIP.
&&
.PREV DISCUSSION...CLOUDS HAVE HUNG IN TIGHT THROUGH THE EARLY
AFTERNOON ACROSS MOST OF SOUTHEAST ARIZONA WITH RELATIVELY THICK MID
LEVEL CLOUDS FROM THE TUCSON AREA EASTWARD. PLENTY OF MOISTURE
REMAINS IN PLACE WITH GPS PW VALUES NOW RANGING FROM 1.5 TO 1.8
INCHES ACROSS THE REGION. LATEST RADAR DOES INDICATE SOME LIGHT
SHOWERS ESPECIALLY ACROSS COCHISE AND SANTA CRUZ COUNTIES MOVING TO
THE NORTH. FARTHER WEST ACROSS CENTRAL AND WESTERN PIMA COUNTY WHERE
WE`VE SEEN SOME CLEARING...ISOLATED SHOWERS AND THUNDERSTORMS HAVE
DEVELOPED AND ARE PRODUCING LOCALLY HEAVY RAINFALL. GIVEN THAT
CLOUDS HAVE HUNG ON TIGHT ACROSS MOST OF THE FORECAST AREA...EXPECT
THE BULK OF THE STORMS CAPABLE OF PRODUCING HEAVY RAINFALL ACROSS
WESTERN AREAS. FOR MUCH OF THE REMAINDER OF THE FORECAST AREA THAT
HAS BEEN UNDER THE EXTENSIVE CLOUDS...CONVECTION WILL STRUGGLE TO
DEVELOP GIVEN THE COOLER TEMPERATURES. WITH THAT SAID...STILL HAVE
ONLY MADE SOME MINOR TWEAKS TO THE POPS THIS AFTERNOON AND THIS
EVENING AS THE SHOWER ACTIVITY KEEPS THE RELATIVELY HIGHER POPS
JUSTIFIED. JUST DON`T SEE MUCH OF A HEAVY RAIN/FLASH FLOOD POTENTIAL
EXCEPT FOR THOSE AREAS THAT ARE SEEING SOME SUN AND DAYTIME HEATING.
FOR FRIDAY INTO SATURDAY...STILL PLENTY OF MOISTURE WITH HIGH
PRESSURE PARKED TO OUR NORTH. THERE IS A POTENTIAL FOR THESE TO BE
VERY ACTIVE STORM DAYS...THOUGH THIS WILL BE DEPENDENT AGAIN ON
CLOUD COVER AND RESULTING DAYTIME HEATING. MOISTURE VALUES WILL
GRADUALLY TREND DOWN NEXT WEEK AS THE HIGH PRESSURE ALOFT NUDGES
SOUTHWARD. THIS WILL RESULT IN MORE OF A STANDARD MONSOON PATTERN
FORECAST. DAYTIME TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH THE
WEEKEND WITH NEAR NORMAL DAYTIME TEMPERATURES NEXT WEEK.
&&
.AVIATION...CLOUD BASES 4-7K FT AGL WITH SCT-BKN LAYERS 100-150K FT
AGL THRU FRIDAY AFTERNOON OR 18/00Z. SCT TSRA THRU 17/03Z WEST OF A
KCGZ-KOLS LINE WITH SCT SHRA EAST. MVFR CIGS AND VSBYS WITH GUSTS TO
40KTS IN TSRA. AFTER DARK EXPECT SCT SHRA WITH ISOLD TSRA EMBEDDED
AT TIMES. A BETTER CHANCE FOR MORE WIDESPREAD TSRA AFT 17/18Z.
OUTSIDE OF TSRA...SFC WIND LESS THAN 12 KTS EXCEPT NW GUSTS 20 KTS
NEAR KSAD AND SURROUNDING VALLEY THRU 17/01Z. AVIATION DISCUSSION
NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...AMPLE MONSOONAL MOISTURE WILL LEAD TO ROUNDS OF
SHOWERS AND THUNDERSTORMS INTO THROUGH THE FORECAST PERIOD WITH
SIGNIFICANT RAINFALL POSSIBLE. FAIRLY HIGH HUMIDITIES AND BELOW
NORMAL DAYTIME TEMPERATURES WILL PREVAIL THROUGH SATURDAY AFTER
WHICH A TREND TOWARD NORMAL TEMPERATURES AND HUMIDITIES IS EXPECTED.
GUSTY AND ERRATIC WINDS ARE POSSIBLE NEAR THUNDERSTORMS.
&&
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE
&&
$$
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 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 TALLAHASSEE FL
920 PM EDT Thu Aug 16 2012
.NEAR TERM [Until 7 AM Friday Morning]...
Updated at: 920pm
Earlier convection has diminished quickly over the past 1-2 hours,
so PoPs have been cut back for the remainder of the evening. There
are still some isolated showers in the eastern part of our area
near outflow from earlier storms, and there are still a few
patches of light rain from the mid-upper level anvil debris from
earlier storms to our west. PoPs were kept in the 20-30% range in
both of those areas, but brought down to 10% for the rest of the
area prior to 06z. After 06z, high-resolution models agree that
convection should regenerate over the Gulf, and there are already
hints of this about 40-50nm offshore of PNS-PAM. Therefore, PoPs
were bumped up to 50-60% offshore after 06z, tapering down to
about 15% along I-10, and 10% north of that. Included some fog to
the north of I-10 where rain isn`t in the forecast late tonight as
some of the cirrus may begin to erode over the next few hours.
There is an impressive MCS that has recently tracked into W/C KY,
and the HRRR weakens this as it takes it SE into SE TN by 07z.
Therefore, this is not expected to continue to track into our
area, although any leftover convectively induced vort maxes could
potentially play a role in thunderstorm trends for Friday.
&&
.SHORT TERM [Friday Morning Through Saturday Night]...
There are high chances for rain and thunderstorms for Friday and
Saturday as an upper level trough continues to strengthen. On
Friday, expect highs in the lower 90s. There are higher PoPs
closer to the western portion of the CWA in the morning and
pushing eastward in the afternoon. At this time storms are
forecast to stay closer to the coast and decrease after sunset.
Friday night, lows will be in the 70s and rain chances will be
higher over the waters. Saturday, highs will be in the lower 90s
again. There are widespread chances for rain and thunderstorms for
Saturday.
&&
.LONG TERM [Sunday through Thursday]...
Little has changed with our thinking since last night. This
period should be a convectively active one. The long wave trough
will remain in place across the eastern U.S. through the period.
Amplification into the southeastern states is expected from the
weekend into early next week as short wave energy over the
Northern Plains dives into the larger trough. This trough will
take on a positive tilt by Sunday with the axis remaining west of
the area. An upper level jet streak will lift across the Mid
Atlantic and Northeast states on Sunday with the right entrance
region extending southwestward into our forecast area on Sunday
and Monday. Even as this jet moves east, impulses of short wave
energy will be intermittently moving through the base on the
trough. So there will be support at upper levels that will enhance
convection.
At the surface, the front currently stalled along the northern
border of our forecast area will remain in place through much of the
period. 1000-700 mb flow to the south of the boundary will be out of
the west or southwest (regimes 4 and 5) into Tuesday. These are
favorable sea breeze climo regimes for high convective coverage.
With all of these factors in play, we will strive to maintain a PoP
at or above climo levels. The GFS indicates that drier air will work
into the region from the north from Tuesday afternoon into Thursday.
The Euro does not support this, nor does climatology. We will only
show a modest drop off in PoP from Tuesday onward. The abundant
cloud cover and precipitation will result in max temps generally
running a couple of degrees below normal. Min temps should be close
to or slightly above normal, at least through Wednesday.
&&
.AVIATION [through 00z Saturday]...
Updated at: 920pm
Most of the rain has ended for tonight. The latest model/MOS
guidance doesn`t forecast much in the way of fog or low clouds
tonight. The high clouds and mesoscale "cool pools" from Thursday
afternoon`s TSRA cast more uncertainty about the potential for IFR
conditions tonight. Because of this uncertainty, we backed off of
the IFR cigs from the previous TAF package, and now expect just
temporary MVFR conditions at some of the terminals around dawn.
Prevailing VFR conditions are expected by mid Friday morning, with
scattered TSRA developing by early afternoon. Winds will be light
out of the west, except near TSRA.
&&
.MARINE...
At the surface, the subtropical ridge remains over the
northern Gulf for most of the period. At upper levels, a trough is
strengthening and may push the cold front currently over the Midwest
into our area early next week. In the mean time, the winds will be
mostly from the west through the period with the possibility of
northwesterly winds with the frontal passage on Monday. Winds are
expected to remain below 15 knots throughout the period and waves
should be 2 feet or less.
&&
.FIRE WEATHER...
Typical of summer, RH will remain well above critical levels over
the next several days and red flag criteria will not be
threatened.
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...Lamers
SHORT TERM...Moore
LONG TERM...Wool
AVIATION...Fournier
MARINE...Moore
FIRE WEATHER...Godsey
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 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 GOODLAND KS
841 PM MDT THU AUG 16 2012
.UPDATE...
ISSUED AT 840 PM MDT THU AUG 16 2012
MADE MINOR ADJUSTMENTS TO POP/WX FORECAST FOR TONIGHT...KEEPING
CHANCE POPS IN FAR EASTERN CWA. 00Z HAS TRENDED FURTHER
SOUTH AND EAST WITH AXIS OF FRONOTGENETIC FORCING AND POSITIVE
THETA-E ADVECTION. I DIDNT WANT TO IGNORE THE LATEST RUC QPF WHICH
WOULD SUPPORT ACTIVITY FURTHER WEST...HOWEVER CONSIDERING THE BEST
LARGE SCALE SUPPORT DOESNT LOOK BE THERE I KEPT CHANCES LIMITED TO
20 PERCENT ACROSS MOST OF THE CWA. OVERALL TIMING FROM PREVIOUS
FORECAST STILL LOOKS GOOD WITH ANY SHOWERS/ISOLATED THUNDERSTORMS
DEVELOPING AROUND 09Z IN THE SOUTHEAST...SPREADING NORTH AND EAST
THROUGH FRIDAY MORNING BEFORE MOVING OUT OF OUR CWA AROUND 15Z.
UPDATE ISSUED AT 356 PM MDT THU AUG 16 2012
JUST COMPLETED MINOR UPDATE TO CAPTURE LATEST TREND REGARDING
POPS/SKY OVER WESTERN PARTS OF CWA. ACTIVITY OVER FRONT RANGE
CURRENTLY PROGRESSING EASTWARD TOWARDS WESTERN EXTENT OF CWA.
BASED ON LATEST RUC INSTABILITY REMAINS VERY WEAK OVER OUR CWA
AND THERE IS LITTLE IN THE WAY OF LARGE SCALE ASCENT. JUST BASED
ON CURRENT RADAR TRENDS AND RUC QPF I COULDNT RULE OUT AN ISOLATED
SHOWER OR THUNDERSTORM SNEAKING INTO WESTERN YUMA AND KIT CARSON
COUNTIES LATE THIS AFTERNOON OR EARLY THIS EVENING BEFORE DIURNAL
HEATING COMES TO AN END AND LOW LEVEL LAPSE RATES DECREASE. NO
OTHER SIGNIFICANT CHANGE MADE.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 210 PM MDT THU AUG 16 2012
18Z WATER VAPOR IMAGERY INDICATED AN UPPER LEVEL SHORT WAVE TROUGH
OVER THE NORTH CENTRAL CONUS...WITH THE TROUGH AXIS EXTENDING
SOUTHWEST INTO WESTERN KANSAS. AT THE SURFACE HIGH PRESSURE WAS
OVER THE NEBRASKA PANHANDLE...BUILDING SOUTHEAST. THE COLD FRONT WAS
BACKED UP AGAINST THE ROCKIES AND EXTENDED SOUTHEAST INTO THE TEXAS
PANHANDLE.
TONIGHT WINDS WILL BE LIGHT AS THE HIGH PRESSURE BUILDS INTO THE
AREA. DURING THE OVERNIGHT HOURS THE SURFACE HIGH MOVES EAST OF THE
AREA. MEANWHILE WARM AIR ADVECTION IN THE 750-650 MB LAYER AND
MOISTURE INCREASE OVER THE EASTERN PART OF THE AREA BEHIND THE
SURFACE HIGH. A DRY LAYER WILL REMAIN IN PLACE BELOW 750MB SO WILL
KEEP THE PRECIPITATION CHANCES IN THE SLIGHT CATEGORY.
EARLY FRIDAY MORNING WARM AIR ADVECTION INCREASES AND AN UPPER LEVEL
SHORT WAVE TROUGH MOVES OVER THE EASTERN HALF OF THE AREA.
INCREASED PRECIP. CHANCES DURING THE FIRST HALF OF THE MORNING WHEN
THE LIFT AND MOISTURE WILL BE GREATEST. DURING THE LATE MORNING AND
AFTERNOON THE BETTER ISENTROPIC LIFT/MOISTURE MOVE EAST WITH THE
SHORT WAVE TROUGH...BRINGING PRECIPITATION CHANCES TO AN END FROM WEST
TO EAST. DURING THE LATE AFTERNOON SURFACE CONVERGENCE/LIFT FROM A
700MB SHORT WAVE TROUGH DEVELOP OVER LINCOLN COUNTY CO. POINT
SOUNDINGS SHOW THE AIR MASS EITHER BEING TOO DRY OR CAPPED. HOWEVER
AS THE SURFACE HIGH MOVES EAST IT WILL DRAG THE FRONT ACROSS THE
WEST HALF OF AREA WITH IT. WILL INCLUDE LOW SLIGHT CHANCES OVER THE
FAR WEST DURING THE LATE AFTERNOON DUE TO THE SHORT WAVE AND FRONT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 210 PM MDT THU AUG 16 2012
NORTHWEST FLOW WILL CONTINUE THROUGH SUNDAY WITH A RIDGE OVER THE
ROCKIES AND AN UPPER LOW NORTH OF THE GREAT LAKES. SURFACE HIGH
PRESSURE WILL RESIDE OVER THE CENTRAL PLAINS THROUGH THIS TIME.
A SHORTWAVE COMES THROUGH THE FLOW FRIDAY NIGHT/EARLY SATURDAY. THE
BEST FORCING COMES ACROSS THE FA FRIDAY NIGHT WITH DYNAMICS EXITING
ALL BUT THE EASTERN FA SATURDAY MORNING. SUBSIDENCE MOVES INTO THE
FA SATURDAY AFTERNOON/NIGHT. SUBSIDENCE CONTINUES SUNDAY. 850-700
LAYER MEAN RH IS LIMITED WITH THE BEST MOISTURE JUST TO THE EAST OF
THE FA. DUE TO THE LIMITED MOISTURE WILL GO WITH SLIGHT CHANCE POPS
FRIDAY NIGHT/EARLY SATURDAY WITH NIL POPS SATURDAY AFTERNOON/NIGHT
THROUGH SUNDAY.
MIN TEMPERATURES WILL BE IN THE MID 50S FRIDAY NIGHT AND THE LOWER
TO MID 50S SATURDAY NIGHT. MAX TEMPERATURES WILL RISE TO THE LOWER
80S SATURDAY/SUNDAY.
FOR SUNDAY NIGHT THROUGH THURSDAY...A RIDGE WILL BE OVER THE ROCKIES
THROUGH THURSDAY. OTHER THAN SURFACE HIGH PRESSURE SUNDAY, A TROUGH
WILL EXIST OVER EASTERN COLORADO THROUGH THURSDAY.
SHORTWAVES IN THE FLOW WILL BRING A SLIGHT CHANCE OF THUNDERSTORMS
MONDAY THROUGH TUESDAY NIGHT. DYNAMICS MOVE OFF TO THE NORTHEAST
WEDNESDAY WITH SUBSIDENCE FOLLOWING WEDNESDAY NIGHT/THURSDAY.
850 TEMPERATURES INDICATE STEADILY WARMER TEMPERATURES WITH MAX
TEMPERATURES IN THE MID 80S MONDAY WARMING TO THE LOWER 90S
WEDNESDAY COOLING SLIGHTLY TO THE UPPER 80S THURSDAY. MIN
TEMPERATURES WILL RANGE FROM THE LOWER 60S TO THE MID 60S.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 516 PM MDT THU AUG 16 2012
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD AT BOTH KGLD AND
KMCK TERMINALS. LIGHT EAST/SOUTHEAST WINDS ARE EXPECTED OVERNIGHT.
WINDS WILL INCREASE AFTER SUNRISE FRIDAY...PRIMARILY AT KGLD WHERE
GUSTS AROUND 22-24KT WILL BE POSSIBLE THROUGH THE DAY. PRECIP
CHANCES REMAIN IN PLACE PRIMARILY SOUTH AND EAST OF BOTH TERMINALS
WHERE BETTER LIFT/INSTABILITY IS EXPECTED. WILL LEAVE MENTION OUT
OF TAFS WITH UNCERTAINTY TO GREAT OVER TERMINALS. COULD ALSO SEE
VIRGA EARLY THIS EVENING AS ACTIVITY OVER EASTERN COLORADO MOVES
EAST AND WEAKENS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...DR
SHORT TERM...FS
LONG TERM...JTL
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
517 PM MDT THU AUG 16 2012
.UPDATE...
ISSUED AT 356 PM MDT THU AUG 16 2012
JUST COMPLETED MINOR UPDATE TO CAPTURE LATEST TREND REGARDING
POPS/SKY OVER WESTERN PARTS OF CWA. ACTIVITY OVER FRONT RANGE
CURRENTLY PROGRESSING EASTWARD TOWARDS WESTERN EXTENT OF CWA.
BASED ON LATEST RUC INSTABILITY REMAINS VERY WEAK OVER OUR CWA
AND THERE IS LITTLE IN THE WAY OF LARGE SCALE ASCENT. JUST BASED
ON CURRENT RADAR TRENDS AND RUC QPF I COULDNT RULE OUT AN ISOLATED
SHOWER OR THUNDERSTORM SNEAKING INTO WESTERN YUMA AND KIT CARSON
COUNTIES LATE THIS AFTERNOON OR EARLY THIS EVENING BEFORE DIURNAL
HEATING COMES TO AN END AND LOW LEVEL LAPSE RATES DECREASE. NO
OTHER SIGNIFICANT CHANGE MADE.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 210 PM MDT THU AUG 16 2012
18Z WATER VAPOR IMAGERY INDICATED AN UPPER LEVEL SHORT WAVE TROUGH
OVER THE NORTH CENTRAL CONUS...WITH THE TROUGH AXIS EXTENDING
SOUTHWEST INTO WESTERN KANSAS. AT THE SURFACE HIGH PRESSURE WAS
OVER THE NEBRASKA PANHANDLE...BUILDING SOUTHEAST. THE COLD FRONT WAS
BACKED UP AGAINST THE ROCKIES AND EXTENDED SOUTHEAST INTO THE TEXAS
PANHANDLE.
TONIGHT WINDS WILL BE LIGHT AS THE HIGH PRESSURE BUILDS INTO THE
AREA. DURING THE OVERNIGHT HOURS THE SURFACE HIGH MOVES EAST OF THE
AREA. MEANWHILE WARM AIR ADVECTION IN THE 750-650 MB LAYER AND
MOISTURE INCREASE OVER THE EASTERN PART OF THE AREA BEHIND THE
SURFACE HIGH. A DRY LAYER WILL REMAIN IN PLACE BELOW 750MB SO WILL
KEEP THE PRECIPITATION CHANCES IN THE SLIGHT CATEGORY.
EARLY FRIDAY MORNING WARM AIR ADVECTION INCREASES AND AN UPPER LEVEL
SHORT WAVE TROUGH MOVES OVER THE EASTERN HALF OF THE AREA.
INCREASED PRECIP. CHANCES DURING THE FIRST HALF OF THE MORNING WHEN
THE LIFT AND MOISTURE WILL BE GREATEST. DURING THE LATE MORNING AND
AFTERNOON THE BETTER ISENTROPIC LIFT/MOISTURE MOVE EAST WITH THE
SHORT WAVE TROUGH...BRINGING PRECIPITATION CHANCES TO AN END FROM WEST
TO EAST. DURING THE LATE AFTERNOON SURFACE CONVERGENCE/LIFT FROM A
700MB SHORT WAVE TROUGH DEVELOP OVER LINCOLN COUNTY CO. POINT
SOUNDINGS SHOW THE AIR MASS EITHER BEING TOO DRY OR CAPPED. HOWEVER
AS THE SURFACE HIGH MOVES EAST IT WILL DRAG THE FRONT ACROSS THE
WEST HALF OF AREA WITH IT. WILL INCLUDE LOW SLIGHT CHANCES OVER THE
FAR WEST DURING THE LATE AFTERNOON DUE TO THE SHORT WAVE AND FRONT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 210 PM MDT THU AUG 16 2012
NORTHWEST FLOW WILL CONTINUE THROUGH SUNDAY WITH A RIDGE OVER THE
ROCKIES AND AN UPPER LOW NORTH OF THE GREAT LAKES. SURFACE HIGH
PRESSURE WILL RESIDE OVER THE CENTRAL PLAINS THROUGH THIS TIME.
A SHORTWAVE COMES THROUGH THE FLOW FRIDAY NIGHT/EARLY SATURDAY. THE
BEST FORCING COMES ACROSS THE FA FRIDAY NIGHT WITH DYNAMICS EXITING
ALL BUT THE EASTERN FA SATURDAY MORNING. SUBSIDENCE MOVES INTO THE
FA SATURDAY AFTERNOON/NIGHT. SUBSIDENCE CONTINUES SUNDAY. 850-700
LAYER MEAN RH IS LIMITED WITH THE BEST MOISTURE JUST TO THE EAST OF
THE FA. DUE TO THE LIMITED MOISTURE WILL GO WITH SLIGHT CHANCE POPS
FRIDAY NIGHT/EARLY SATURDAY WITH NIL POPS SATURDAY AFTERNOON/NIGHT
THROUGH SUNDAY.
MIN TEMPERATURES WILL BE IN THE MID 50S FRIDAY NIGHT AND THE LOWER
TO MID 50S SATURDAY NIGHT. MAX TEMPERATURES WILL RISE TO THE LOWER
80S SATURDAY/SUNDAY.
FOR SUNDAY NIGHT THROUGH THURSDAY...A RIDGE WILL BE OVER THE ROCKIES
THROUGH THURSDAY. OTHER THAN SURFACE HIGH PRESSURE SUNDAY, A TROUGH
WILL EXIST OVER EASTERN COLORADO THROUGH THURSDAY.
SHORTWAVES IN THE FLOW WILL BRING A SLIGHT CHANCE OF THUNDERSTORMS
MONDAY THROUGH TUESDAY NIGHT. DYNAMICS MOVE OFF TO THE NORTHEAST
WEDNESDAY WITH SUBSIDENCE FOLLOWING WEDNESDAY NIGHT/THURSDAY.
850 TEMPERATURES INDICATE STEADILY WARMER TEMPERATURES WITH MAX
TEMPERATURES IN THE MID 80S MONDAY WARMING TO THE LOWER 90S
WEDNESDAY COOLING SLIGHTLY TO THE UPPER 80S THURSDAY. MIN
TEMPERATURES WILL RANGE FROM THE LOWER 60S TO THE MID 60S.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 516 PM MDT THU AUG 16 2012
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD AT BOTH KGLD AND
KMCK TERMINALS. LIGHT EAST/SOUTHEAST WINDS ARE EXPECTED OVERNIGHT.
WINDS WILL INCREASE AFTER SUNRISE FRIDAY...PRIMARILY AT KGLD WHERE
GUSTS AROUND 22-24KT WILL BE POSSIBLE THROUGH THE DAY. PRECIP
CHANCES REMAIN IN PLACE PRIMARILY SOUTH AND EAST OF BOTH TERMINALS
WHERE BETTER LIFT/INSTABILITY IS EXPECTED. WILL LEAVE MENTION OUT
OF TAFS WITH UNCERTAINTY TO GREAT OVER TERMINALS. COULD ALSO SEE
VIRGA EARLY THIS EVENING AS ACTIVITY OVER EASTERN COLORADO MOVES
EAST AND WEAKENS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...DR
SHORT TERM...FS
LONG TERM...JTL
AVIATION...DR
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 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 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
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 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...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 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 GRAND RAPIDS MI
1156 PM EDT THU AUG 16 2012
.SYNOPSIS...
ISSUED AT 333 PM EDT THU AUG 16 2012
A STRONG COLD FRONT COMING THROUGH SOUTHWEST MICHIGAN THIS EVENING
WILL BRING UNSEASONABLY COOL TEMPERATURES TO THE AREA THROUGH THE WEEKEND.
A SLOW WARMING TREND WILL BEGIN BY TUESDAY.
&&
.UPDATE...
ISSUED AT 954 PM EDT THU AUG 16 2012
SHOWERS CONTINUE TO DIMINISH AS THEY MOVE EAST ALONG THE COLD
FRONT. UPDATED GRIDS TO REFLECT LOWER POPS ACROSS THE CWA.
OVERNIGHT SHOULD BE MOSTLY DRY...BUT CAN/T RULE OUT A BRIEF SHOWER
ALONG/NORTH OF US-10 DURING THE NEXT FEW HOURS ASSOCIATED WITH A
SHORT WAVE MOVING ACROSS THE REGION.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 333 PM EDT THU AUG 16 2012
THE BIGGEST ISSUE IS WILL MORE CONVECTION DEVELOP BEFORE THE FRONT
COMES THROUGH EARLY THIS EVENING? OTHER THAN THAT A LARGE CLOSED
UPPER LOW OVER SOUTHERN HUDSON BAY WILL FEED UNSEASONABLY COOL
WEATHER INTO THE AREA THROUGH THROUGH THE SHORT TERM.
THE LARGE AREA OF RAIN COOLED AIR FROM THE MORNING SQUALL LINE HAS
CREATED A LARGE POCKET OF COOL AIR AHEAD OF THE SURFACE COLD
FRONT. MIX LAYER CAPES OVER SOUTHWEST LOWER MICHIGAN AT 3 PM WERE
UNDER 300 J/KG. SO EVEN WITH THE 40 TO 60 KNOTS OF DEEP LAYER
SHEAR AND STRONG SURFACE WIND CONVERGENCE ON THE FRONT... LITTLE
HAS DEVELOPED ON THE FRONT AS OF YET. I DO BELIEVE THE AREA SOUTH
AND EAST OF I-69 WILL HAVE TO BE WATCHED EARLY THIS EVENING AS THE
RAP SHOWS MIX LAYER CAPES RISING IN THAT AREA TO 500 J/KG THERE.
STILL NOT ALL THAT GREAT THROUGH. ALSO THE HRRR RUC SHOWS A LINE
DEVELOPING BETWEEN 22Z AND 01Z MOVING EAST AND INCREASING THROUGH
02Z AS IT EXITS THE SE CWA. I REMAIN UNIMPRESSED SO I HAVE ONLY
30-40 PCT POPS INTO EARLY THIS EVENING.
AFTER THAT A HIGH PRESSURE RIDGE BUILDS IN AND THAT SHOULD HELP TO
CLEAR OUT ANY RESIDUAL LOW CLOUDS THAT NOW COVER MOST OF WI
BEHIND THE FRONT BY MID MORNING FRIDAY. THE AIR REMAINS TO DRY FOR
LAKE EFFECT RAIN SHOWERS SO I KEPT THE FORECAST DRY THROUGH
SATURDAY.
WITH LIGHT WINDS AND DRY AIR WE COULD SEE LOWS IN THE 30S NEAR AND
NORTH OF ROUTE 10 SATURDAY MORNING. STILL THE DEW POINTS WILL BE
TO HIGH FOR FROST SO THAT SHOULD NOT BE MUCH OF A PROBLEM.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 333 PM EDT THU AUG 16 2012
COOL WX WILL CONTINUE SUNDAY AND MONDAY BEFORE TEMPS MODERATE TO
NEAR NORMAL TUESDAY THROUGH THURSDAY. THE UPPER LEVEL TROUGH AND
COLD POOL OF AIR ALOFT IN CONJUNCTION WITH SEVERAL SHORTWAVES
ROTATING AROUND THE UPPER LOW AND SOME SUN WILL COMBINE TO PRODUCE
SCATTERED DIURNALLY DRIVEN SHOWERS SUNDAY AND MONDAY (MAINLY DURING
THE AFTERNOON AND EARLY EVENING).
MAX TEMPS SUNDAY AND MONDAY WILL ONLY REACH THE 70 TO 75 DEGREE
RANGE. DRY AND MILDER WX IS ANTICIPATED TUESDAY THROUGH WEDNESDAY
WITH MAX TEMPS BACK NEAR NORMAL IN THE UPPER 70S TO LOWER 80S. THE
NEXT LOW PRESSURE SYSTEM TO IMPACT OUR AREA WILL BRING A CHC OF
SHOWERS AND TSTORMS BY LATE NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1152 PM EDT THU AUG 16 2012
VFR CONDITIONS EXPECTED THROUGH FRIDAY EVENING. WINDS SHOULD BE
WEST TO NORTHWEST AT 10 KNOTS OR LESS.
&&
.MARINE...
ISSUED AT 333 PM EDT THU AUG 16 2012
ENOUGH WIND AND COLD AIR TO KEEP THE WAVES 3 TO 6 FEET INTO FRIDAY
AFTERNOON SO I WILL CONTINUE OUR BEACH HAZARD EVENT AND SC AS IS.
IT SHOULD BE NOTED THAT THE LUDINGTON BUOY HAD WAVE HEIGHTS AS
HIGH AS 7 FEET THIS MORNING.
&&
.HYDROLOGY...
ISSUED AT 333 PM EDT THU AUG 16 2012
RAINFALL WAS FOR THE MOST PART BETWEEN .3 AND .7 INCHES OF MOST OF
THE WESTERN AND CENTRAL CWA WITH LESSER AMOUNTS TO THE EAST AND
SOUTHEAST. THIS WAS NOT ENOUGH TO CAUSE ANY RIVER RISE ISSUES BUT
SHOULD BE ENOUGH TO MITIGATE DROUGHT ISSUES.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT THROUGH FRIDAY AFTERNOON FOR MIZ037-043-
050-056-064-071.
LM...SMALL CRAFT ADVISORY UNTIL 5 PM EDT FRIDAY FOR LMZ844>849.
&&
$$
UPDATE...93
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...LAURENS
AVIATION...OSTUNO
HYDROLOGY...WDM
MARINE...WDM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
957 PM EDT THU AUG 16 2012
.SYNOPSIS...
ISSUED AT 333 PM EDT THU AUG 16 2012
A STRONG COLD FRONT COMING THROUGH SOUTHWEST MICHIGAN THIS EVENING
WILL BRING UNSEASONABLY COOL TEMPERATURES TO THE AREA THROUGH THE WEEKEND.
A SLOW WARMING TREND WILL BEGIN BY TUESDAY.
&&
.UPDATE...
ISSUED AT 954 PM EDT THU AUG 16 2012
SHOWERS CONTINUE TO DIMINISH AS THEY MOVE EAST ALONG THE COLD
FRONT. UPDATED GRIDS TO REFLECT LOWER POPS ACROSS THE CWA.
OVERNIGHT SHOULD BE MOSTLY DRY...BUT CAN/T RULE OUT A BRIEF SHOWER
ALONG/NORTH OF US-10 DURING THE NEXT FEW HOURS ASSOCIATED WITH A
SHORT WAVE MOVING ACROSS THE REGION.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 333 PM EDT THU AUG 16 2012
THE BIGGEST ISSUE IS WILL MORE CONVECTION DEVELOP BEFORE THE FRONT
COMES THROUGH EARLY THIS EVENING? OTHER THAN THAT A LARGE CLOSED
UPPER LOW OVER SOUTHERN HUDSON BAY WILL FEED UNSEASONABLY COOL
WEATHER INTO THE AREA THROUGH THROUGH THE SHORT TERM.
THE LARGE AREA OF RAIN COOLED AIR FROM THE MORNING SQUALL LINE HAS
CREATED A LARGE POCKET OF COOL AIR AHEAD OF THE SURFACE COLD
FRONT. MIX LAYER CAPES OVER SOUTHWEST LOWER MICHIGAN AT 3 PM WERE
UNDER 300 J/KG. SO EVEN WITH THE 40 TO 60 KNOTS OF DEEP LAYER
SHEAR AND STRONG SURFACE WIND CONVERGENCE ON THE FRONT... LITTLE
HAS DEVELOPED ON THE FRONT AS OF YET. I DO BELIEVE THE AREA SOUTH
AND EAST OF I-69 WILL HAVE TO BE WATCHED EARLY THIS EVENING AS THE
RAP SHOWS MIX LAYER CAPES RISING IN THAT AREA TO 500 J/KG THERE.
STILL NOT ALL THAT GREAT THROUGH. ALSO THE HRRR RUC SHOWS A LINE
DEVELOPING BETWEEN 22Z AND 01Z MOVING EAST AND INCREASING THROUGH
02Z AS IT EXITS THE SE CWA. I REMAIN UNIMPRESSED SO I HAVE ONLY
30-40 PCT POPS INTO EARLY THIS EVENING.
AFTER THAT A HIGH PRESSURE RIDGE BUILDS IN AND THAT SHOULD HELP TO
CLEAR OUT ANY RESIDUAL LOW CLOUDS THAT NOW COVER MOST OF WI
BEHIND THE FRONT BY MID MORNING FRIDAY. THE AIR REMAINS TO DRY FOR
LAKE EFFECT RAIN SHOWERS SO I KEPT THE FORECAST DRY THROUGH
SATURDAY.
WITH LIGHT WINDS AND DRY AIR WE COULD SEE LOWS IN THE 30S NEAR AND
NORTH OF ROUTE 10 SATURDAY MORNING. STILL THE DEW POINTS WILL BE
TO HIGH FOR FROST SO THAT SHOULD NOT BE MUCH OF A PROBLEM.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 333 PM EDT THU AUG 16 2012
COOL WX WILL CONTINUE SUNDAY AND MONDAY BEFORE TEMPS MODERATE TO
NEAR NORMAL TUESDAY THROUGH THURSDAY. THE UPPER LEVEL TROUGH AND
COLD POOL OF AIR ALOFT IN CONJUNCTION WITH SEVERAL SHORTWAVES
ROTATING AROUND THE UPPER LOW AND SOME SUN WILL COMBINE TO PRODUCE
SCATTERED DIURNALLY DRIVEN SHOWERS SUNDAY AND MONDAY (MAINLY DURING
THE AFTERNOON AND EARLY EVENING).
MAX TEMPS SUNDAY AND MONDAY WILL ONLY REACH THE 70 TO 75 DEGREE
RANGE. DRY AND MILDER WX IS ANTICIPATED TUESDAY THROUGH WEDNESDAY
WITH MAX TEMPS BACK NEAR NORMAL IN THE UPPER 70S TO LOWER 80S. THE
NEXT LOW PRESSURE SYSTEM TO IMPACT OUR AREA WILL BRING A CHC OF
SHOWERS AND TSTORMS BY LATE NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 714 PM EDT THU AUG 16 2012
NARROW LINE OF SHOWERS WAS MOVING THROUGH KGRR AT 23Z AND WILL
CLEAR LAN AND JXN BY 02Z. SOME MVFR EXPECTED ALONG THE LINE ALONG
WITH A WIND SHIFT FROM SOUTHWEST TO WEST THEN NORTHWEST. EXPECT
VFR CONDITIONS AFTER THE FRONT CLEARS KJXN LATER THIS EVENING.
&&
.MARINE...
ISSUED AT 333 PM EDT THU AUG 16 2012
ENOUGH WIND AND COLD AIR TO KEEP THE WAVES 3 TO 6 FEET INTO FRIDAY
AFTERNOON SO I WILL CONTINUE OUR BEACH HAZARD EVENT AND SC AS IS.
IT SHOULD BE NOTED THAT THE LUDINGTON BUOY HAD WAVE HEIGHTS AS
HIGH AS 7 FEET THIS MORNING.
&&
.HYDROLOGY...
ISSUED AT 333 PM EDT THU AUG 16 2012
RAINFALL WAS FOR THE MOST PART BETWEEN .3 AND .7 INCHES OF MOST OF
THE WESTERN AND CENTRAL CWA WITH LESSER AMOUNTS TO THE EAST AND
SOUTHEAST. THIS WAS NOT ENOUGH TO CAUSE ANY RIVER RISE ISSUES BUT
SHOULD BE ENOUGH TO MITIGATE DROUGHT ISSUES.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT THROUGH FRIDAY AFTERNOON FOR MIZ037-043-
050-056-064-071.
LM...SMALL CRAFT ADVISORY UNTIL 5 PM EDT FRIDAY FOR LMZ844>849.
&&
$$
UPDATE...93
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...LAURENS
AVIATION...OSTUNO
HYDROLOGY...WDM
MARINE...WDM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
717 PM EDT THU AUG 16 2012
.SYNOPSIS...
ISSUED AT 333 PM EDT THU AUG 16 2012
A STRONG COLD FRONT COMING THROUGH SOUTHWEST MICHIGAN THIS EVENING
WILL BRING UNSEASONABLY COOL TEMPERATURES TO THE AREA THROUGH THE WEEKEND.
A SLOW WARMING TREND WILL BEGIN BY TUESDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 333 PM EDT THU AUG 16 2012
THE BIGGEST ISSUE IS WILL MORE CONVECTION DEVELOP BEFORE THE FRONT
COMES THROUGH EARLY THIS EVENING? OTHER THAN THAT A LARGE CLOSED
UPPER LOW OVER SOUTHERN HUDSON BAY WILL FEED UNSEASONABLY COOL
WEATHER INTO THE AREA THROUGH THROUGH THE SHORT TERM.
THE LARGE AREA OF RAIN COOLED AIR FROM THE MORNING SQUALL LINE HAS
CREATED A LARGE POCKET OF COOL AIR AHEAD OF THE SURFACE COLD
FRONT. MIX LAYER CAPES OVER SOUTHWEST LOWER MICHIGAN AT 3 PM WERE
UNDER 300 J/KG. SO EVEN WITH THE 40 TO 60 KNOTS OF DEEP LAYER
SHEAR AND STRONG SURFACE WIND CONVERGENCE ON THE FRONT... LITTLE
HAS DEVELOPED ON THE FRONT AS OF YET. I DO BELIEVE THE AREA SOUTH
AND EAST OF I-69 WILL HAVE TO BE WATCHED EARLY THIS EVENING AS THE
RAP SHOWS MIX LAYER CAPES RISING IN THAT AREA TO 500 J/KG THERE.
STILL NOT ALL THAT GREAT THROUGH. ALSO THE HRRR RUC SHOWS A LINE
DEVELOPING BETWEEN 22Z AND 01Z MOVING EAST AND INCREASING THROUGH
02Z AS IT EXITS THE SE CWA. I REMAIN UNIMPRESSED SO I HAVE ONLY
30-40 PCT POPS INTO EARLY THIS EVENING.
AFTER THAT A HIGH PRESSURE RIDGE BUILDS IN AND THAT SHOULD HELP TO
CLEAR OUT ANY RESIDUAL LOW CLOUDS THAT NOW COVER MOST OF WI
BEHIND THE FRONT BY MID MORNING FRIDAY. THE AIR REMAINS TO DRY FOR
LAKE EFFECT RAIN SHOWERS SO I KEPT THE FORECAST DRY THROUGH
SATURDAY.
WITH LIGHT WINDS AND DRY AIR WE COULD SEE LOWS IN THE 30S NEAR AND
NORTH OF ROUTE 10 SATURDAY MORNING. STILL THE DEW POINTS WILL BE
TO HIGH FOR FROST SO THAT SHOULD NOT BE MUCH OF A PROBLEM.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 333 PM EDT THU AUG 16 2012
COOL WX WILL CONTINUE SUNDAY AND MONDAY BEFORE TEMPS MODERATE TO
NEAR NORMAL TUESDAY THROUGH THURSDAY. THE UPPER LEVEL TROUGH AND
COLD POOL OF AIR ALOFT IN CONJUNCTION WITH SEVERAL SHORTWAVES
ROTATING AROUND THE UPPER LOW AND SOME SUN WILL COMBINE TO PRODUCE
SCATTERED DIURNALLY DRIVEN SHOWERS SUNDAY AND MONDAY (MAINLY DURING
THE AFTERNOON AND EARLY EVENING).
MAX TEMPS SUNDAY AND MONDAY WILL ONLY REACH THE 70 TO 75 DEGREE
RANGE. DRY AND MILDER WX IS ANTICIPATED TUESDAY THROUGH WEDNESDAY
WITH MAX TEMPS BACK NEAR NORMAL IN THE UPPER 70S TO LOWER 80S. THE
NEXT LOW PRESSURE SYSTEM TO IMPACT OUR AREA WILL BRING A CHC OF
SHOWERS AND TSTORMS BY LATE NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 714 PM EDT THU AUG 16 2012
NARROW LINE OF SHOWERS WAS MOVING THROUGH KGRR AT 23Z AND WILL
CLEAR LAN AND JXN BY 02Z. SOME MVFR EXPECTED ALONG THE LINE ALONG
WITH A WIND SHIFT FROM SOUTHWEST TO WEST THEN NORTHWEST. EXPECT
VFR CONDITIONS AFTER THE FRONT CLEARS KJXN LATER THIS EVENING.
&&
.MARINE...
ISSUED AT 333 PM EDT THU AUG 16 2012
ENOUGH WIND AND COLD AIR TO KEEP THE WAVES 3 TO 6 FEET INTO FRIDAY
AFTERNOON SO I WILL CONTINUE OUR BEACH HAZARD EVENT AND SC AS IS.
IT SHOULD BE NOTED THAT THE LUDINGTON BUOY HAD WAVE HEIGHTS AS
HIGH AS 7 FEET THIS MORNING.
&&
.HYDROLOGY...
ISSUED AT 333 PM EDT THU AUG 16 2012
RAINFALL WAS FOR THE MOST PART BETWEEN .3 AND .7 INCHES OF MOST OF
THE WESTERN AND CENTRAL CWA WITH LESSER AMOUNTS TO THE EAST AND
SOUTHEAST. THIS WAS NOT ENOUGH TO CAUSE ANY RIVER RISE ISSUES BUT
SHOULD BE ENOUGH TO MITIGATE DROUGHT ISSUES.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT THROUGH FRIDAY AFTERNOON FOR MIZ037-043-
050-056-064-071.
LM...SMALL CRAFT ADVISORY UNTIL 5 PM EDT FRIDAY FOR LMZ844>849.
&&
$$
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...LAURENS
AVIATION...OSTUNO
HYDROLOGY...WDM
MARINE...WDM
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 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 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
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...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 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 ALBUQUERQUE NM
913 PM MDT THU AUG 16 2012
.UPDATE...
QUICK ZFP UPDATE JUST SENT. ADJUSTED WINDS IN THE MIDDLE/LOWER RIO
GRANDE VALLEY DUE TO GUSTS TO AROUND 35 MPH CONTINUING AT THE
SUNPORT THIS EVENING. ALSO TRIMMED OVERNIGHT POPS BACK AS
CONVECTION STARTING TO WANE.
&&
.AVIATION...
00Z TAF CYCLE
WHILE VFR CONDITIONS WILL PREVAIL IN MOST LOCALES OF NORTHERN AND
CENTRAL NEW MEXICO...SCATTERED THUNDERSTORMS WILL PRODUCE BRIEF AND
LOCALIZED DOWNPOURS REDUCING VISIBILITIES AND CEILINGS TEMPORARILY
TO MVFR/IFR CONDITIONS. FAVORED AREAS FOR DEVELOPMENT THROUGH
MIDNIGHT WILL BE ALONG AND NEAR THE WEST CENTRAL TO SOUTHWESTERN
MOUNTAINS...THE RIO GRANDE VALLEY...THE CENTRAL MOUNTAIN CHAIN...AND
THE EASTERN PLAINS. GUSTY AND ERRATIC WINDS AND SMALL HAIL WILL ALSO
ACCOMPANY THE DOWNPOURS. SOME ACTIVITY MAY LINGER BEYOND
MIDNIGHT...BUT ACTIVITY WILL BE NOTABLY REDUCING IN COVERAGE.
ANOTHER ACTIVE DAY IS ANTICIPATED ON FRIDAY WITH FAIRLY SIMILAR
COVERAGE AND PLACEMENT.
52
&&
.PREV DISCUSSION...323 PM MDT THU AUG 16 2012...
DEFINITE INCREASE IN STORM STRENGTH AND COVERAGE TODAY AS EXPECTED
WITH SEVERAL FORCING MECHANISMS IN PLACE OVER THE STATE. CIRA BLENDED
PWAT IMAGERY SHOWING VALUES OF 100-125 PCT OF NORMAL. THE AXIS OF THE
H5 RIDGE IS POSITIONED FROM NORTHERN AZ SOUTHEAST ACROSS WEST CENTRAL
NM. H5 TEMPS OF -6 TO -7C ARE HELPING NOT TO CAP ANY CONVECTION AS
HAS BEEN THE CASE. WINDS ARE ALSO VERY WEAK ABOVE 700MB SO COMBINATION
OF HIGHER MOISTURE...COOLER TEMPS ALOFT...AND GOOD SURFACE HEATING WILL
ALLOW FOR LOCALLY HEAVY RAINFALL THRU THIS EVENING. THE HRRR AND RUC
MODELS INDICATE CONVECTION WILL ORGANIZE INTO THE MIDDLE RIO GRANDE
VALLEY SOUTHEASTWARD SO HAVE RAISED POPS TO HIGH CHANCE AND LIKELY.
DID NOT HAVE HIGH ENOUGH CONFIDENCE TO PLACE LOCALLY HEAVY RAINFALL
WORDING IN FORECAST FOR TONIGHT...AND FOR THAT MATTER THE NEXT FEW
DAYS...AS IT WILL BE HARD TO PINPOINT ANY SPECIFIC AREA FOR ENHANCED
THREAT.
THE H5 RIDGE AXIS WILL CHANGE LITTLE OVER THE NEXT FEW DAYS...SETTING
UP WEAK STEERING FLOW FOR CENTRAL AND WESTERN NM WHILE THE EAST ENJOYS
THE BENEFITS OF NW FLOW ALOFT. LIGHT UPSLOPE FLOW ACROSS THE PLAINS
ONTO THE EAST SLOPES BENEATH NW FLOW WILL BE FAVORABLE FOR POTENTIALLY
SOME OF BEST PRECIP SEEN IN QUITE SOME TIME. ANOTHER BACK DOOR FRONT
SUNDAY WILL JUST ENHANCE MOISTURE AND PRECIP CHANCES AGAIN. RAISED
POPS EVEN MORE TO THE HIGH CHANCE/LIKELY CATEGORY THRU THE WEEKEND.
TEMPS WILL BE MUCH CLOSER TO NORMAL AND EVEN A FEW DEGREES BELOW. GAP
WINDS ARE EXPECTED AGAIN IN THE RIO GRANDE VALLEY SATURDAY EVENING
INTO SUNDAY MORNING.
MODELS REMAIN AT ODDS BEYOND THE WEEKEND WITH HOW MUCH CONDITIONS WILL
DRY OUT. THE GFS HAS THE RIDGE SLIDING EAST AND CENTERING OVER CENTRAL
NM MONDAY THRU MOST OF NEXT WEEK...WHILE THE ECMWF KEEPS THE RIDGE TO
THE WEST AND FORCING MORE BACK DOOR FRONTS INTO THE AREA. GIVEN THE
PATTERN THIS SUMMER WILL BE FAVORING THE ECMWF AT THIS TIME...WHICH
WILL KEEP TEMPS NEAR NORMAL AND PRECIP CHANCES PERHAPS AT CLIMO FOR
LATE AUGUST. GUYER
&&
.FIRE WEATHER...
CRITICAL FIRE WEATHER...NOT EXPECTED THROUGH AT LEAST MIDWEEK NEXT
WEEK.
FCST MODELS REMAIN IN FAIRLY GOOD AGREEMENT ON GENERAL FCST PATTERN
THROUGH THE START TO MIDDLE OF NEXT WEEK. UPPER HIGH CENTER TO
CONTINUE TO MEANDER BACK AND FORTH GENERALLY BETWEEN NV AND AZ. THIS
WILL ALLOW FOR SOME WEAK TO MODERATE LOW LVL MOISTURE REPLENISHMENT
FROM THE E THROUGH S FROM TIME TO TIME WITH COMBINATION OF WESTBOUND
THROUGH NORTHBOUND OUTFLOWS FROM STORM COMPLEXES IN S AND E HALVES
OF THE STATE AS WELL AS CURRENT WEAKENING BACK DOOR FRONT VCNTY OF
RIO GRANDE VALLEY AS OF THIS WRITING AND ANOTHER ONE DUE INTO E AND
PERHAPS CENTRAL NM OVER THE WEEKEND.
SHOWERS AND STORMS THIS EVE AND OVERNIGHT TO BE MOST NUMEROUS...AND
WITH GOOD WETTING FOOTPRINTS...TO E OF THE CONTINENTAL DIVIDE WITH
MOST LIGHTNING OVER WITH BY OR NOT TOO LONGER AFTER MIDNIGHT...
ESPECIALLY HIGHER TERRAIN. GOOD TO EXCELLENT HUMIDITY RECOVERIES
OVERNIGHT.
FOR FRIDAY...ACTIVE CONVECTION EXPECTED ACROSS THE STATE...WITH
WETTING RAINS THE BEST BET AGAIN E OF DIVIDE. MINIMUM HUMIDITIES
INCREASING TO THE HIGH 20S TO THE MID 40S PCT RANGE OVER MUCH OF THE
STATE...WITH SOME HIGH TEENS AND 20S PCT REMAINING OVER THE DRYER
NORTHWEST QUADRANT. AGAIN GOOD TO EXCELLENT HUMIDITY RECOVERY
OVERNIGHT.
SATURDAY WILL BRING WEAK COLD FRONT INTO THE NORTHEAST PLAINS...
PROGRESSING TO THE S AND W LATER IN THE DAY THROUGH SUN AM. WETTING
RAINS MOST LIKELY ALONG AND E THROUGH N OF FRONTAL BOUNDARY. NW
PLATEAU STILL GETTING THE SHORT END OF THE STICK WITH REGARDS TO
CONVECTION AND WETTING RAIN. VERY GOOD TO EXCELLENT RECOVERIES
OVERNIGHT FOR ALL BUT THE NORTHWEST...WHERE RECOVERY WILL DROP BACK
INTO THE GOOD CATEGORY. FOR SUN THROUGH TUE THE UPPER HIGH AND RIDGE
STILL GENERALLY TO W OF NM. PRETTY GOOD CHANCES FOR WETTING RAINS
SUNDAY BUT BEGINNING A BIT OF A DOWNTURN MON AND TUE. AFTN TEMPS
SHOULD WARM A FEW DEGREES MOST AREAS BY MON OR TUE AND THIS WILL
LOWER MIN HUMIDITIES AND LESSEN OVERNIGHT RECOVERIES. 43
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
547 PM MDT THU AUG 16 2012
.AVIATION...
00Z TAF CYCLE
WHILE VFR CONDITIONS WILL PREVAIL IN MOST LOCALES OF NORTHERN AND
CENTRAL NEW MEXICO...SCATTERED THUNDERSTORMS WILL PRODUCE BRIEF AND
LOCALIZED DOWNPOURS REDUCING VISIBILITIES AND CEILINGS TEMPORARILY
TO MVFR/IFR CONDITIONS. FAVORED AREAS FOR DEVELOPMENT THROUGH
MIDNIGHT WILL BE ALONG AND NEAR THE WEST CENTRAL TO SOUTHWESTERN
MOUNTAINS...THE RIO GRANDE VALLEY...THE CENTRAL MOUNTAIN CHAIN...AND
THE EASTERN PLAINS. GUSTY AND ERRATIC WINDS AND SMALL HAIL WILL ALSO
ACCOMPANY THE DOWNPOURS. SOME ACTIVITY MAY LINGER BEYOND
MIDNIGHT...BUT ACTIVITY WILL BE NOTABLY REDUCING IN COVERAGE.
ANOTHER ACTIVE DAY IS ANTICIPATED ON FRIDAY WITH FAIRLY SIMILAR
COVERAGE AND PLACEMENT.
52
&&
.PREV DISCUSSION...323 PM MDT THU AUG 16 2012...
DEFINITE INCREASE IN STORM STRENGTH AND COVERAGE TODAY AS EXPECTED
WITH SEVERAL FORCING MECHANISMS IN PLACE OVER THE STATE. CIRA BLENDED
PWAT IMAGERY SHOWING VALUES OF 100-125 PCT OF NORMAL. THE AXIS OF THE
H5 RIDGE IS POSITIONED FROM NORTHERN AZ SOUTHEAST ACROSS WEST CENTRAL
NM. H5 TEMPS OF -6 TO -7C ARE HELPING NOT TO CAP ANY CONVECTION AS
HAS BEEN THE CASE. WINDS ARE ALSO VERY WEAK ABOVE 700MB SO COMBINATION
OF HIGHER MOISTURE...COOLER TEMPS ALOFT...AND GOOD SURFACE HEATING WILL
ALLOW FOR LOCALLY HEAVY RAINFALL THRU THIS EVENING. THE HRRR AND RUC
MODELS INDICATE CONVECTION WILL ORGANIZE INTO THE MIDDLE RIO GRANDE
VALLEY SOUTHEASTWARD SO HAVE RAISED POPS TO HIGH CHANCE AND LIKELY.
DID NOT HAVE HIGH ENOUGH CONFIDENCE TO PLACE LOCALLY HEAVY RAINFALL
WORDING IN FORECAST FOR TONIGHT...AND FOR THAT MATTER THE NEXT FEW
DAYS...AS IT WILL BE HARD TO PINPOINT ANY SPECIFIC AREA FOR ENHANCED
THREAT.
THE H5 RIDGE AXIS WILL CHANGE LITTLE OVER THE NEXT FEW DAYS...SETTING
UP WEAK STEERING FLOW FOR CENTRAL AND WESTERN NM WHILE THE EAST ENJOYS
THE BENEFITS OF NW FLOW ALOFT. LIGHT UPSLOPE FLOW ACROSS THE PLAINS
ONTO THE EAST SLOPES BENEATH NW FLOW WILL BE FAVORABLE FOR POTENTIALLY
SOME OF BEST PRECIP SEEN IN QUITE SOME TIME. ANOTHER BACK DOOR FRONT
SUNDAY WILL JUST ENHANCE MOISTURE AND PRECIP CHANCES AGAIN. RAISED
POPS EVEN MORE TO THE HIGH CHANCE/LIKELY CATEGORY THRU THE WEEKEND.
TEMPS WILL BE MUCH CLOSER TO NORMAL AND EVEN A FEW DEGREES BELOW. GAP
WINDS ARE EXPECTED AGAIN IN THE RIO GRANDE VALLEY SATURDAY EVENING
INTO SUNDAY MORNING.
MODELS REMAIN AT ODDS BEYOND THE WEEKEND WITH HOW MUCH CONDITIONS WILL
DRY OUT. THE GFS HAS THE RIDGE SLIDING EAST AND CENTERING OVER CENTRAL
NM MONDAY THRU MOST OF NEXT WEEK...WHILE THE ECMWF KEEPS THE RIDGE TO
THE WEST AND FORCING MORE BACK DOOR FRONTS INTO THE AREA. GIVEN THE
PATTERN THIS SUMMER WILL BE FAVORING THE ECMWF AT THIS TIME...WHICH
WILL KEEP TEMPS NEAR NORMAL AND PRECIP CHANCES PERHAPS AT CLIMO FOR
LATE AUGUST. GUYER
.FIRE WEATHER...
CRITICAL FIRE WEATHER...NOT EXPECTED THROUGH AT LEAST MIDWEEK NEXT
WEEK.
FCST MODELS REMAIN IN FAIRLY GOOD AGREEMENT ON GENERAL FCST PATTERN
THROUGH THE START TO MIDDLE OF NEXT WEEK. UPPER HIGH CENTER TO
CONTINUE TO MEANDER BACK AND FORTH GENERALLY BETWEEN NV AND AZ. THIS
WILL ALLOW FOR SOME WEAK TO MODERATE LOW LVL MOISTURE REPLENISHMENT
FROM THE E THROUGH S FROM TIME TO TIME WITH COMBINATION OF WESTBOUND
THROUGH NORTHBOUND OUTFLOWS FROM STORM COMPLEXES IN S AND E HALVES
OF THE STATE AS WELL AS CURRENT WEAKENING BACK DOOR FRONT VCNTY OF
RIO GRANDE VALLEY AS OF THIS WRITING AND ANOTHER ONE DUE INTO E AND
PERHAPS CENTRAL NM OVER THE WEEKEND.
SHOWERS AND STORMS THIS EVE AND OVERNIGHT TO BE MOST NUMEROUS...AND
WITH GOOD WETTING FOOTPRINTS...TO E OF THE CONTINENTAL DIVIDE WITH
MOST LIGHTNING OVER WITH BY OR NOT TOO LONGER AFTER MIDNIGHT...
ESPECIALLY HIGHER TERRAIN. GOOD TO EXCELLENT HUMIDITY RECOVERIES
OVERNIGHT.
FOR FRIDAY...ACTIVE CONVECTION EXPECTED ACROSS THE STATE...WITH
WETTING RAINS THE BEST BET AGAIN E OF DIVIDE. MINIMUM HUMIDITIES
INCREASING TO THE HIGH 20S TO THE MID 40S PCT RANGE OVER MUCH OF THE
STATE...WITH SOME HIGH TEENS AND 20S PCT REMAINING OVER THE DRYER
NORTHWEST QUADRANT. AGAIN GOOD TO EXCELLENT HUMIDITY RECOVERY
OVERNIGHT.
SATURDAY WILL BRING WEAK COLD FRONT INTO THE NORTHEAST PLAINS...
PROGRESSING TO THE S AND W LATER IN THE DAY THROUGH SUN AM. WETTING
RAINS MOST LIKELY ALONG AND E THROUGH N OF FRONTAL BOUNDARY. NW
PLATEAU STILL GETTING THE SHORT END OF THE STICK WITH REGARDS TO
CONVECTION AND WETTING RAIN. VERY GOOD TO EXCELLENT RECOVERIES
OVERNIGHT FOR ALL BUT THE NORTHWEST...WHERE RECOVERY WILL DROP BACK
INTO THE GOOD CATEGORY. FOR SUN THROUGH TUE THE UPPER HIGH AND RIDGE
STILL GENERALLY TO W OF NM. PRETTY GOOD CHANCES FOR WETTING RAINS
SUNDAY BUT BEGINNING A BIT OF A DOWNTURN MON AND TUE. AFTN TEMPS
SHOULD WARM A FEW DEGREES MOST AREAS BY MON OR TUE AND THIS WILL
LOWER MIN HUMIDITIES AND LESSEN OVERNIGHT RECOVERIES. 43
.AVIATION...
18Z TAF CYCLE
BACK DOOR COLD FRONT AS OF MIDDAY LOCATED APPROX FROM WESTERN RIO
ARRIBA COUNTY THEN SOUTHWARD JUST TO THE WEST OF THE MIDDLE RIO
GRANDE VALLEY THEN INTO EASTERN SOCORRO COUNTY. THIS FRONT WILL NOT
LIKELY MOVE TOO MUCH FARTHER WEST THROUGH LATE AFTN...BUT SHOULD
MAKE IT TO OR A LITTLE WAYS EITHER SIDE OF THE CONTINENTAL DIVIDE
TONIGHT. THIS PATTERN WILL SET UP SCT TO AT TIMES NUMEROUS SHRA AND
TSRA COVERAGE LATE THIS AFTERNOON INTO TONIGHT. IN TAFS...VCTS SHOWS
MOST LIKELY EXPECTED TIME OF THUNDERSTORM ACTIVITY IN VCNTY OF SAID
AIRPORT. THE LATER VCSH GROUPS INDICATE REDUCED BUT NOT ZERO
LIGHTNING POTENTIAL AND SOME RAINFALL REMAINING IN VCNTY FOR ALL
POINTS. HEAVIER RAINFALL TODAY MAY DROP CIGS AND VSBY TO MVFR IN
HEAVIER TSTMS FOR RELATIVELY BRIEF PERIODS. TSRA DIMINISHING AFTER 4
OR 5Z OTHERWISE...VFR CONDITIONS AT ALL POINTS OVER THE NEXT 24
HOURS. 43
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
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 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 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 CLEVELAND OH
950 PM EDT THU AUG 16 2012
.SYNOPSIS...
A COLD FRONT ACROSS THE WESTERN GREAT LAKES WILL MOVE EAST ACROSS
THE LOCAL AREA TONIGHT. THE FRONT WILL MOVE TO THE EAST COAST
FRIDAY ALLOWING HIGH PRESSURE TO BEGIN BUILDING OVER THE REGION
FROM THE WEST. THE HIGH IS EXPECTED TO LINGER OVER THE REGION
THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
COLD FRONT CONTINUES TO PUSH EAST INTO INDIANA THIS EVENING AND
WILL MOVE ACROSS THE FORECAST AREA LATER OVERNIGHT AND TUE
MORNING. RADAR SHOWING MOST OF CONVECTION IN MICHIGAN. MOST MODELS
SUGGESTING SOME ADDITIONAL CONVECTION DEVELOPING NEAR THE FRONT
AND MOVE INTO NRN OHIO OVERNIGHT...BUT WILL HAVE TO SEE GIVEN
THUNDERSTORM COMPLEX SOUTHWEST OF THE AREA. FOR NOW LEFT THE
CATEGORICAL POPS OVER THE AREA AS THINKING MOST LOCATIONS WILL SEE
AT LEAST A BRIEF PERIOD OF SHRA/TS WITH THE FRONTAL PASSAGE. MADE
SMALL ADJUSTMENTS TO TEMPS BUT NOTHING SIGNIFICANT FOR THE
OVERNIGHT WITH LOWER TO MID 60S ACROSS THE AREA.
PREVIOUS DISCUSSION...
THE AREA OF SHOWERS MOVING TOWARD NW OH CONTINUES TO BREAK UP BUT
HAVE STARTED TO SEE SOME NEW DEVELOPMENT IN FAR NE OH ALONG A LAKE
BREEZE BOUNDARY. THESE TRENDS WILL LIKELY CONTINUE FOR THE
REMAINDER OF THE AFTERNOON WITH AN INCREASE IN ACTIVITY IN THE
EAST AND A DECREASE IN THE WEST. HRRR AND CONVECTIVE SREF CONTINUE
TO SHOW ANOTHER LINE OF STORMS DEVELOPING JUST TO THE WEST OF THE
AREA TOWARD 00Z AHEAD OF AN APPROACHING COLD FRONT. THIS IS THE
LINE THAT WILL LIKELY BRING PRECIP TO THE ENTIRE AREA OVERNIGHT.
WILL CONTINUE WITH CATEGORICAL PRECIP CHANCES WITH MOST AREAS
SEEING UP TO A HALF INCH OF RAINFALL. THE PRECIP WILL END FROM
WEST TO EAST AFTER MIDNIGHT AS THE FRONT PULLS OUT. THICK CLOUDS
HAVE OVERSPREAD THE AREA AND THE THREAT FOR SEVERE WEATHER APPEARS
MINIMAL. BETTER INSTABILITY REMAINS TO THE SW AND THAT IS WHERE
ANY SEVERE WEATHER WILL LIKELY OCCUR.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY NIGHT/...
THE COLD FRONT WILL BE GONE BY DAYBREAK AND MOST OF THE PRECIP
ALONG WITH IT. COULD SEE SOME SHOWERS IN THE EAST AND SOUTH
THROUGH MIDDAY BUT AFTER THAT IT SHOULD BE TOO DRY FOR MORE
PRECIP. 850 MB TEMPS WILL DIP TO AROUND PLUS 8 BY FRIDAY EVENING
SO THIS WILL BE A COLD AIRMASS. WILL LIKELY SEE A FAIR AMOUNT OF
LAKE EFFECT STATO CU THROUGH SATURDAY. SOME INDICATION FROM THE
MODELS OF ANOTHER WEAK FRONT APPROACHING FROM THE NORTH LATE
SUNDAY AND SUNDAY NIGHT. WILL GO WITH A VERY SMALL MENTION OF
SHOWERS IN THE FAR NORTH BUT REALLY DON`T THINK THIS WILL BE A BIG
DEAL. TEMPS WILL AVERAGE WELL BELOW NORMAL AND LATER SHIFTS WILL
HAVE TO WATCH FOR POSSIBLE 40S FOR LOWS SUNDAY MORNING. HAVE USED
A BLEND OF GUIDANCE DURING THE PERIOD.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
INITIALLY LONG RANGE PART OF FORECAST SHOULD START OFF COOL AND
SOMEWHAT CLOUD. THE BIG QUESTION IS WHETHER THE UPPER TROF OVER THE
AREA WILL CAUSE ENOUGH FORCING TO PRODUCE A FEW SHRA...ESPECIALLY IN
THE SNOWBELT OR WHETHER SURFACE HIGH PRESSURE WILL KEEP THINGS DRY.
PREFERENCE IS TO CARRY AT LEAST A SLIGHT CHANCE FOR THE NE PART OF
THE AREA MON THEN GO DRY TUE AS THE UPPER TROF WEAKENS AND SHIFT
EAST.
WED LOOKS DRY AS TEMPS WARM BACK TO NORMAL. THE MODELS DIFFER BY THU
SO MUCH GREATER UNCERTAINTY IN OVERALL FORECAST. THUS FORECAST WILL
LARGELY BE INFLUENCED BY BEST COLLABORATION WITH SURROUNDING WFO`S.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
NOTHING BUT HIGH CLOUDS INITIALLY TONIGHT. THE COLD FRONT SHOULD
CROSS NORTHWEST OHIO 05Z- 07Z AND NE OH/NW PA 08Z-13Z. WILL ALLOW
A FOUR HOUR TEMPO FOR SHOWERS/STORMS WITH THE FRONTAL PASSAGE AND
MAYBE AN EXTRA HOUR OR TWO FOR SHOWERS ACROSS NE OH/NW PA FRIDAY
MORNING. CEILINGS SHOULD COME DOWN TO MVFR AN HOUR OR TWO AFTER
THE FRONTAL PASSAGE. CEILINGS WILL IMPROVE TO VFR FROM WEST TO
EAST FRIDAY AFTERNOON WITH CLEARING FROM WEST TO EAST LATER IN THE
DAY.
.OUTLOOK...VFR EXCEPT FOR A CHANCE OF MVFR CEILINGS EXTREME
NE OH/NW PA MONDAY AND TUESDAY MORNING.
&&
.MARINE...
COLD FRONT WILL MOVE INTO THE CENTRAL GREAT LAKES TONIGHT. EXPECT TO
SEE SOUTHWEST WINDS TO REMAIN IN THE 10 TO 20 KNOT RANGE. HOWEVER
THE EASTERN HALF OF THE LAKE COULD SEE SLIGHTLY HIGHER FOR A COUPLE
HOURS JUST AHEAD OF THE FRONT AFTER MIDNIGHT. WILL THEN AWAIT THE
WIND SHIFT TO CLEAR LAKE ERIE NEAR OR SHORTLY AFTER SUNRISE.
NORTHWESTERLY WINDS MAY BE JUST STRONG ENOUGH WITH THE LONGER FETCH
TO PROVIDE SMALL CRAFT CONDITIONS FOR THE EASTERN HALF TO TWO THIRDS
OF THE LAKE INTO FRIDAY AFTERNOON. WILL LET THE NEXT SHIFT MONITOR
THIS POTENTIAL OVERNIGHT TO DECIDE IF WE WILL REACH THE CRITERIA.
HIGH PRESSURE WILL THEN CONTROL THE LAKE WITH A LIGHT WEST TO
NORTHWEST WIND EXPECTED THROUGH THE WEEKEND. SOUTHWESTERLY WINDS
SHOULD RETURN BY MONDAY AFTERNOON AND SHOULD PERSIST INTO TUESDAY
AHEAD OF THE NEXT COLD FRONT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KUBINA
NEAR TERM...ABE/KUBINA
SHORT TERM...KUBINA
LONG TERM...ADAMS
AVIATION...KOSARIK
MARINE...MULLEN
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
930 PM EDT THU AUG 16 2012
.SYNOPSIS...
STRONG COLD FRONT CROSSES TOMORROW. WEAK HIGH PRESSURE OVER
WEEKEND...WITH DISTURBANCE ALOFT PASSING SUNDAY. ANOTHER HIGH
PRESSURE BUILDS NEXT WEEK.
&&
.NEAR TERM /THROUGH FRIDAY/...
915 PM UPDATE. VERY DIFFICULT. IMPRESSIVE MCS DROPPING EAST
SOUTHEAST INTO WESTERN KENTUCKY AT TIME WILL SURELY DISRUPT THE
MODEL CONSENSUS OF TRYING TO REFOCUS CONVECTION NORTHWARD ALONG
FRONT LATER ON TONIGHT. HAVE ADJUSTED POPS OVERNIGHT TO RAISE POPS
IN THE WEST AND SOUTHWEST FOR EASTWARD EXTENSION OF THE DYING MCS BY
THAT TIME. IN TURN...WHILE KEEPING REDEVELOPMENT FURTHER NORTH AS
THE FRONT MAKES IT TO OUR CWA BORDER BY 12Z...HAVE CUT CAT POPS TO
LIKELY. THIS MAY STILL BE TOO GENEROUS...BUT DID NOT WANT TO MAKE
WHOLESALE CHANGES THIS FAR OUT. OTHERWISE...WILL CONTINUE PLAYING AN
EARLY MORNING BAND OF CONVECTION SURGING OUR AHEAD OF THE FRONT...
AND A BETTER AFTERNOON CONVECTIVE BAND WITH THE FRONT AS IT MOVES
ACROSS.
PREVIOUS DISCUSSION...
MORNING COMPLEX CONT TO WEAKEN AS IT RUNS IN TO DRY AIR IN MID
LVLS AND AWAY FROM COLD FRONT/UPR SUPPORT. RUC AND RAP DO INDICATE
A SLIGHT MOISTENING ACROSS PERRY/MORGAN 22-00Z WHICH MAY BE ENOUGH
FOR AN ISO SHRA/TSRA AS REMNANTS...AT LEAST ALOFT...MOVE ACROSS E
OH. THUS ELECTED TO CODE UP SCHC ACROSS PERRY DURING
AFOREMENTIONED TIME FRAME.
OTHERWISE WILL BE WAITING FOR APPROACH OF UPR TROF AND ASSOCIATED
SFC FRONT HEADING INTO TOMORROW. LIKED TIMING OF PREV FCST WHICH
IS IN GOOD AGREEMENT WITH NAM. LOOKS LIKE AREA WILL BE DEALING
WITH TWO POSSIBLE BANDS OF PCPN...PREFRONTAL BAND IN THE MORNING
FOLLOWED BY A ROUND OF CONVECTION MORE WITH ACTUAL FRONT. HAVE SFC
FRONT JUST ENTERING SE OH AT 12Z WITH PREFRONTAL BAND HAVING
TRAVERSED THRU SE OH/NE KY INTO CENTRAL WV...AIDED MORE BY DECENT
OMEGA ARND H7 AND LLVL WAA. EXPECT THIS TO FIZZLE OUT AS IT HEADS
INTO MTNS BY MID MORNING. WILL KEEP THUNDER IN GIVEN ELEVATED
INSTABILITY. MEANWHILE FRONT MAY SLOW DOWN BRIEFLY TOMORROW WITH
ANOTHER ORGANIZED BAND OF INITIALLY FRONTAL CONVECTION MOVING
ACROSS THE AREA AFTER A BRIEF BREAK FOLLOWING MORNING CONVECTION.
THIS LOOKS TO PROPAGATE OUT AHEAD OF BOUNDARY IN AFTN AND EXIT
MTNS BY 21Z AS DEEPER MOISTURE IS EXODUS. WILL HANG SOME LOW POPS
BACK A FEW HRS WITH SFC FRONT ONLY CROSSING OH RVR BY SAID TIME.
WILL GO WITH HIGHER NUMBERS TONIGHT WITH BL FLOW INCREASING LATE.
HIGHS TOMORROW TRICKY. WILL LEAN TOWARD LOWER NUMBERS FROM
GUIDANCE.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
COLD FRONT EXPECTED TO BE EXIT THE EASTERN MOUNTAINS AT THE
BEGINNING OF THE PERIOD WITH PCPN DECREASING FROM CHANCE TO SLIGHT
CHANCE THROUGH 12Z SATURDAY. DEWPOINTS WILL LINGER INTO THE LOWER
60S EXTREME NORTHEAST...UPPER TO MID 50S EAST OF THE OH
RIVER...DROPPING TO THE LOW 50S ACROSS SOUTHEAST OH BY SATURDAY
MORNING.
HIGH PRESSURE BUILDS BEHIND THE FRONT WITH DRIER AIR TO PROVIDE
PLENTY OF SUNSHINE SATURDAY. WITH ABUNDANT LINGERING MOISTURE OVER
THE EASTERN MOUNTAINS...KEPT SLIGHT CHANCE FOR AFTERNOON SHOWERS.
WITH THE EXPECTED WIDESPREAD CLEARING SATURDAY AND SUNDAY
NIGHTS...DENSE FOG IS A GOOD BET OVER AREAS THAT RECEIVE RAIN AND
ALONG RIVER VALLEYS DUE TO NEAR CLAM FLOW.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
HIGH PRESSURE STRENGTHENS THROUGH MID WEEK PROVIDING MOSTLY CLEAR
SKIES AND NORMAL TEMPERATURES. HOWEVER...THE GFS SUGGEST UPPER LEVEL
SYNOPTIC LIFT ASSOCIATED WITH AND UPPER LEVEL JET...ALTHOUGH
MOISTURE IS LIMITED PER PWATS AROUND 0.75 INCHES...FEW SHOWERS COULD
DEVELOP ONCE AGAIN OVER THE EASTERN MOUNTAINS SUNDAY AFTERNOON.
OTHERWISE...DRY WEATHER AND PLEASANT TEMPERATURES WILL PREVAIL
THROUGH THE END OF THE WEEK.
SOME WARM AIR ADVECTION NOTICED AT H850 FROM 11C TO 14-16C FROM
THE GFS/ECMWF UNDER WEAK SOUTHERLY FLOW FROM WED THROUGH THE END
OF THE WEEK. THEREFORE...INCREASED TEMPS TO THE MID TO UPPER 80S
SIMILAR TO HPC AND GMOS FROM WEDNESDAY THROUGH END OF THE PERIOD.
USED HPC TEMPS...WITH SOME TWEAKS DAY 5 THROUGH DAY 7.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
00Z FRIDAY TO 00Z SATURDAY...
VFR CONDITIONS PREVAIL INTO MUCH OF THE NIGHT. WITH BL FLOW
INCREASING MVFR/IFR FG SHOULD BE MITIGATED TO MTN VALLEYS AND HAVE
KEKN IN IFR FG BY 06Z BEFORE PERHAPS IMPROVING BY DAWN. OTHERWISE
SOME MID AND HI CLDS INCREASE LATE TONIGHT FROM W TO E WITH
PREFRONTAL CONVECTIVE PCPN MOVING ACROSS SE OH INTO CENTRAL WV BY
12Z. WILL CARRY MVFR IN SHRA WITH VCTS AT THIS DISTANCE. COLD FRONT
ENTERS SE OH ARND 12Z...TAKING MUCH OF THE DAYLIGHT HRS TO CROSS OH
RVR WITH ANOTHER ROUND OF CONVECTION ASSOCIATED WITH FRONT PUSHING
ACROSS LATE MORNING THRU AFTN WITH LCL IFR CONDITIONS EXPECTED.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z SATURDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: POTENTIAL CONVECTION EARLY FRI MORNING MAY
DIMINISH DEPENDING ON THUNDERSTORM COMPLEX DROPPING SOUTHEAST THRU
WESTERN KENTUCKY EARLY TONIGHT.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE FRI 08/17/12
UTC 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
EDT 1HRLY 22 23 00 01 02 03 04 05 06 07 08 09
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H M M H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H M L L H H H H H H
PKB CONSISTENCY H H H H H H H H H M M M
CKB CONSISTENCY H H H H H H H H H H M M
AFTER 00Z SATURDAY...
IFR POSSIBLE IN THUNDERSTORMS FRI AND IN LOW CLOUDS AND / OR FOG SAT
MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/30
NEAR TERM...JMV/30
SHORT TERM...ARJ
LONG TERM...ARJ
AVIATION...JMV
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
752 PM EDT THU AUG 16 2012
.SYNOPSIS...
A COLD FRONT ACROSS THE WESTERN GREAT LAKES WILL MOVE EAST ACROSS
THE LOCAL AREA TONIGHT. THE FRONT WILL MOVE TO THE EAST COAST
FRIDAY ALLOWING HIGH PRESSURE TO BEGIN BUILDING OVER THE REGION
FROM THE WEST. THE HIGH IS EXPECTED TO LINGER OVER THE REGION
THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
LATEST ANALYSIS SHOWING A WEAK PREFRONTAL TROUGH OVER NW OHIO WITH
CONVECTION TO THE SOUTHWEST. MEANWHILE...THE ACTUAL COLD FRONT IS
STILL LOCATED WELL BACK TO THE WEST NEAR ORD THIS EVENING.
REGIONAL RADAR SHOWING SOME CONVECTION DEVELOPING IN SW MICHIGAN
MORE ASSOCIATED WITH THE FRONT...AND FOCUSED ON THAT FOR THE
OVERNIGHT AS THE PRIMARY MEANS OF SHRA/TS OVER THE AREA. CONCERNED
ALSO WITH THE INTERACTION OF THE LAKE SO INTRODUCED CHC POPS TO NE
OH/NW PA CLOSER TO THE LAKESHORE BY 05Z OR SO. TIMED CATEGORICAL
POPS ACROSS THE AREA THROUGH THE OVERNIGHT...BUT WORDING IN
FORECAST INDICATED HIGH POPS MAINLY AFTER MIDNIGHT WHICH AT THIS
POINT IS REASONABLE. NO CHANGES TO TEMPS AT THIS TIME BUT WILL
TAKE A LOOK FOR NEXT UPDATE. PREVIOUS DISCUSSION BELOW.
THE AREA OF SHOWERS MOVING TOWARD NW OH CONTINUES TO BREAK UP BUT
HAVE STARTED TO SEE SOME NEW DEVELOPMENT IN FAR NE OH ALONG A LAKE
BREEZE BOUNDARY. THESE TRENDS WILL LIKELY CONTINUE FOR THE
REMAINDER OF THE AFTERNOON WITH AN INCREASE IN ACTIVITY IN THE
EAST AND A DECREASE IN THE WEST. HRRR AND CONVECTIVE SREF CONTINUE
TO SHOW ANOTHER LINE OF STORMS DEVELOPING JUST TO THE WEST OF THE
AREA TOWARD 00Z AHEAD OF AN APPROACHING COLD FRONT. THIS IS THE
LINE THAT WILL LIKELY BRING PRECIP TO THE ENTIRE AREA OVERNIGHT.
WILL CONTINUE WITH CATEGORICAL PRECIP CHANCES WITH MOST AREAS
SEEING UP TO A HALF INCH OF RAINFALL. THE PRECIP WILL END FROM
WEST TO EAST AFTER MIDNIGHT AS THE FRONT PULLS OUT. THICK CLOUDS
HAVE OVERSPREAD THE AREA AND THE THREAT FOR SEVERE WEATHER APPEARS
MINIMAL. BETTER INSTABILITY REMAINS TO THE SW AND THAT IS WHERE
ANY SEVERE WEATHER WILL LIKELY OCCUR.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY NIGHT/...
THE COLD FRONT WILL BE GONE BY DAYBREAK AND MOST OF THE PRECIP
ALONG WITH IT. COULD SEE SOME SHOWERS IN THE EAST AND SOUTH
THROUGH MIDDAY BUT AFTER THAT IT SHOULD BE TOO DRY FOR MORE
PRECIP. 850 MB TEMPS WILL DIP TO AROUND PLUS 8 BY FRIDAY EVENING
SO THIS WILL BE A COLD AIRMASS. WILL LIKELY SEE A FAIR AMOUNT OF
LAKE EFFECT STATO CU THROUGH SATURDAY. SOME INDICATION FROM THE
MODELS OF ANOTHER WEAK FRONT APPROACHING FROM THE NORTH LATE
SUNDAY AND SUNDAY NIGHT. WILL GO WITH A VERY SMALL MENTION OF
SHOWERS IN THE FAR NORTH BUT REALLY DON`T THINK THIS WILL BE A BIG
DEAL. TEMPS WILL AVERAGE WELL BELOW NORMAL AND LATER SHIFTS WILL
HAVE TO WATCH FOR POSSIBLE 40S FOR LOWS SUNDAY MORNING. HAVE USED
A BLEND OF GUIDANCE DURING THE PERIOD.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
INITIALLY LONG RANGE PART OF FORECAST SHOULD START OFF COOL AND
SOMEWHAT CLOUD. THE BIG QUESTION IS WHETHER THE UPPER TROF OVER THE
AREA WILL CAUSE ENOUGH FORCING TO PRODUCE A FEW SHRA...ESPECIALLY IN
THE SNOWBELT OR WHETHER SURFACE HIGH PRESSURE WILL KEEP THINGS DRY.
PREFERENCE IS TO CARRY AT LEAST A SLIGHT CHANCE FOR THE NE PART OF
THE AREA MON THEN GO DRY TUE AS THE UPPER TROF WEAKENS AND SHIFT
EAST.
WED LOOKS DRY AS TEMPS WARM BACK TO NORMAL. THE MODELS DIFFER BY THU
SO MUCH GREATER UNCERTAINTY IN OVERALL FORECAST. THUS FORECAST WILL
LARGELY BE INFLUENCED BY BEST COLLABORATION WITH SURROUNDING WFO`S.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
NOTHING BUT HIGH CLOUDS INITIALLY TONIGHT. THE COLD FRONT SHOULD
CROSS NORTHWEST OHIO 05Z- 07Z AND NE OH/NW PA 08Z-13Z. WILL ALLOW
A FOUR HOUR TEMPO FOR SHOWERS/STORMS WITH THE FRONTAL PASSAGE AND
MAYBE AN EXTRA HOUR OR TWO FOR SHOWERS ACROSS NE OH/NW PA FRIDAY
MORNING. CEILINGS SHOULD COME DOWN TO MVFR AN HOUR OR TWO AFTER
THE FRONTAL PASSAGE. CEILINGS WILL IMPROVE TO VFR FROM WEST TO
EAST FRIDAY AFTERNOON WITH CLEARING FROM WEST TO EAST LATER IN THE
DAY.
.OUTLOOK...VFR EXCEPT FOR A CHANCE OF MVFR CEILINGS EXTREME
NE OH/NW PA MONDAY AND TUESDAY MORNING.
&&
.MARINE...
COLD FRONT WILL MOVE INTO THE CENTRAL GREAT LAKES TONIGHT. EXPECT TO
SEE SOUTHWEST WINDS TO REMAIN IN THE 10 TO 20 KNOT RANGE. HOWEVER
THE EASTERN HALF OF THE LAKE COULD SEE SLIGHTLY HIGHER FOR A COUPLE
HOURS JUST AHEAD OF THE FRONT AFTER MIDNIGHT. WILL THEN AWAIT THE
WIND SHIFT TO CLEAR LAKE ERIE NEAR OR SHORTLY AFTER SUNRISE.
NORTHWESTERLY WINDS MAY BE JUST STRONG ENOUGH WITH THE LONGER FETCH
TO PROVIDE SMALL CRAFT CONDITIONS FOR THE EASTERN HALF TO TWO THIRDS
OF THE LAKE INTO FRIDAY AFTERNOON. WILL LET THE NEXT SHIFT MONITOR
THIS POTENTIAL OVERNIGHT TO DECIDE IF WE WILL REACH THE CRITERIA.
HIGH PRESSURE WILL THEN CONTROL THE LAKE WITH A LIGHT WEST TO
NORTHWEST WIND EXPECTED THROUGH THE WEEKEND. SOUTHWESTERLY WINDS
SHOULD RETURN BY MONDAY AFTERNOON AND SHOULD PERSIST INTO TUESDAY
AHEAD OF THE NEXT COLD FRONT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KUBINA
NEAR TERM...ABE/KUBINA
SHORT TERM...KUBINA
LONG TERM...ADAMS
AVIATION...KOSARIK
MARINE...MULLEN
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
745 PM EDT THU AUG 16 2012
.SYNOPSIS...
STRONG COLD FRONT CROSSES TOMORROW. WEAK HIGH
PRESSURE OVER WEEKEND...WITH DISTURBANCE ALOFT PASSING SUNDAY.
ANOTHER HIGH PRESSURE BUILDS NEXT WEEK
&&
.NEAR TERM /THROUGH FRIDAY/...
MORNING COMPLEX CONT TO WEAKEN AS IT RUNS IN TO DRY AIR IN MID
LVLS AND AWAY FROM COLD FRONT/UPR SUPPORT. RUC AND RAP DO INDICATE
A SLIGHT MOISTENING ACROSS PERRY/MORGAN 22-00Z WHICH MAY BE ENOUGH
FOR AN ISO SHRA/TSRA AS REMNANTS...AT LEAST ALOFT...MOVE ACROSS E
OH. THUS ELECTED TO CODE UP SCHC ACROSS PERRY DURING
AFOREMENTIONED TIME FRAME.
OTHERWISE WILL BE WAITING FOR APPROACH OF UPR TROF AND ASSOCIATED
SFC FRONT HEADING INTO TOMORROW. LIKED TIMING OF PREV FCST WHICH
IS IN GOOD AGREEMENT WITH NAM. LOOKS LIKE AREA WILL BE DEALING
WITH TWO POSSIBLE BANDS OF PCPN...PREFRONTAL BAND IN THE MORNING
FOLLOWED BY A ROUND OF CONVECTION MORE WITH ACTUAL FRONT. HAVE SFC
FRONT JUST ENTERING SE OH AT 12Z WITH PREFRONTAL BAND HAVING
TRAVERSED THRU SE OH/NE KY INTO CENTRAL WV...AIDED MORE BY DECENT
OMEGA ARND H7 AND LLVL WAA. EXPECT THIS TO FIZZLE OUT AS IT HEADS
INTO MTNS BY MID MORNING. WILL KEEP THUNDER IN GIVEN ELEVATED
INSTABILITY. MEANWHILE FRONT MAY SLOW DOWN BRIEFLY TOMORROW WITH
ANOTHER ORGANIZED BAND OF INITIALLY FRONTAL CONVECTION MOVING
ACROSS THE AREA AFTER A BRIEF BREAK FOLLOWING MORNING CONVECTION.
THIS LOOKS TO PROPAGATE OUT AHEAD OF BOUNDARY IN AFTN AND EXIT
MTNS BY 21Z AS DEEPER MOISTURE IS EXODUS. WILL HANG SOME LOW POPS
BACK A FEW HRS WITH SFC FRONT ONLY CROSSING OH RVR BY SAID TIME.
WILL GO WITH HIGHER NUMBERS TONIGHT WITH BL FLOW INCREASING LATE.
HIGHS TOMORROW TRICKY. WILL LEAN TOWARD LOWER NUMBERS FROM
GUIDANCE.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
COLD FRONT EXPECTED TO BE EXIT THE EASTERN MOUNTAINS AT THE
BEGINNING OF THE PERIOD WITH PCPN DECREASING FROM CHANCE TO SLIGHT
CHANCE THROUGH 12Z SATURDAY. DEWPOINTS WILL LINGER INTO THE LOWER
60S EXTREME NORTHEAST...UPPER TO MID 50S EAST OF THE OH
RIVER...DROPPING TO THE LOW 50S ACROSS SOUTHEAST OH BY SATURDAY
MORNING.
HIGH PRESSURE BUILDS BEHIND THE FRONT WITH DRIER AIR TO PROVIDE
PLENTY OF SUNSHINE SATURDAY. WITH ABUNDANT LINGERING MOISTURE OVER
THE EASTERN MOUNTAINS...KEPT SLIGHT CHANCE FOR AFTERNOON SHOWERS.
WITH THE EXPECTED WIDESPREAD CLEARING SATURDAY AND SUNDAY
NIGHTS...DENSE FOG IS A GOOD BET OVER AREAS THAT RECEIVE RAIN AND
ALONG RIVER VALLEYS DUE TO NEAR CLAM FLOW.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
HIGH PRESSURE STRENGTHENS THROUGH MID WEEK PROVIDING MOSTLY CLEAR
SKIES AND NORMAL TEMPERATURES. HOWEVER...THE GFS SUGGEST UPPER LEVEL
SYNOPTIC LIFT ASSOCIATED WITH AND UPPER LEVEL JET...ALTHOUGH
MOISTURE IS LIMITED PER PWATS AROUND 0.75 INCHES...FEW SHOWERS COULD
DEVELOP ONCE AGAIN OVER THE EASTERN MOUNTAINS SUNDAY AFTERNOON.
OTHERWISE...DRY WEATHER AND PLEASANT TEMPERATURES WILL PREVAIL
THROUGH THE END OF THE WEEK.
SOME WARM AIR ADVECTION NOTICED AT H850 FROM 11C TO 14-16C FROM
THE GFS/ECMWF UNDER WEAK SOUTHERLY FLOW FROM WED THROUGH THE END
OF THE WEEK. THEREFORE...INCREASED TEMPS TO THE MID TO UPPER 80S
SIMILAR TO HPC AND GMOS FROM WEDNESDAY THROUGH END OF THE PERIOD.
USED HPC TEMPS...WITH SOME TWEAKS DAY 5 THROUGH DAY 7.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
00Z FRIDAY TO 00Z SATURDAY...
VFR CONDITIONS PREVAIL INTO MUCH OF THE NIGHT. WITH BL FLOW
INCREASING MVFR/IFR FG SHOULD BE MITIGATED TO MTN VALLEYS AND HAVE
KEKN IN IFR FG BY 06Z BEFORE PERHAPS IMPROVING BY DAWN. OTHERWISE
SOME MID AND HI CLDS INCREASE LATE TONIGHT FROM W TO E WITH
PREFRONTAL CONVECTIVE PCPN MOVING ACROSS SE OH INTO CENTRAL WV BY
12Z. WILL CARRY MVFR IN SHRA WITH VCTS AT THIS DISTANCE. COLD FRONT
ENTERS SE OH ARND 12Z...TAKING MUCH OF THE DAYLIGHT HRS TO CROSS OH
RVR WITH ANOTHER ROUND OF CONVECTION ASSOCIATED WITH FRONT PUSHING
ACROSS LATE MORNING THRU AFTN WITH LCL IFR CONDITIONS EXPECTED.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z SATURDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: POTENTIAL CONVECTION EARLY FRI MORNING MAY
DIMINISH DEPENDING ON THUNDERSTORM COMPLEX DROPPING SOUTHEAST THRU
WESTERN KENTUCKY EARLY TONIGHT.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE FRI 08/17/12
UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11
EDT 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H M
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H M H L L H H H H
PKB CONSISTENCY H H H H H H H H H H H M
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 00Z SATURDAY...
IFR POSSIBLE IN THUNDERSTORMS FRI AND IN LOW CLOUDS AND / OR FOG SAT
MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/30
NEAR TERM...30
SHORT TERM...ARJ
LONG TERM...ARJ
AVIATION...JMV
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
719 PM EDT THU AUG 16 2012
.SYNOPSIS...
A COLD FRONT ACROSS THE WESTERN GREAT LAKES WILL MOVE EAST ACROSS
THE LOCAL AREA TONIGHT. THE FRONT WILL MOVE TO THE EAST COAST
FRIDAY ALLOWING HIGH PRESSURE TO BEGIN BUILDING OVER THE REGION
FROM THE WEST. THE HIGH IS EXPECTED TO LINGER OVER THE REGION
THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
LATEST ANALYSIS SHOWING A WEAK PREFRONTAL TROUGH OVER NW OHIO WITH
CONVECTION TO THE SOUTHWEST. MEANWHILE...THE ACTUAL COLD FRONT IS
STILL LOCATED WELL BACK TO THE WEST NEAR ORD THIS EVENING.
REGIONAL RADAR SHOWING SOME CONVECTION DEVELOPING IN SW MICHIGAN
MORE ASSOCIATED WITH THE FRONT...AND FOCUSED ON THAT FOR THE
OVERNIGHT AS THE PRIMARY MEANS OF SHRA/TS OVER THE AREA. CONCERNED
ALSO WITH THE INTERACTION OF THE LAKE SO INTRODUCED CHC POPS TO NE
OH/NW PA CLOSER TO THE LAKESHORE BY 05Z OR SO. TIMED CATEGORICAL
POPS ACROSS THE AREA THROUGH THE OVERNIGHT...BUT WORDING IN
FORECAST INDICATED HIGH POPS MAINLY AFTER MIDNIGHT WHICH AT THIS
POINT IS REASONABLE. NO CHANGES TO TEMPS AT THIS TIME BUT WILL
TAKE A LOOK FOR NEXT UPDATE. PREVIOUS DISCUSSION BELOW.
THE AREA OF SHOWERS MOVING TOWARD NW OH CONTINUES TO BREAK UP BUT
HAVE STARTED TO SEE SOME NEW DEVELOPMENT IN FAR NE OH ALONG A LAKE
BREEZE BOUNDARY. THESE TRENDS WILL LIKELY CONTINUE FOR THE
REMAINDER OF THE AFTERNOON WITH AN INCREASE IN ACTIVITY IN THE
EAST AND A DECREASE IN THE WEST. HRRR AND CONVECTIVE SREF CONTINUE
TO SHOW ANOTHER LINE OF STORMS DEVELOPING JUST TO THE WEST OF THE
AREA TOWARD 00Z AHEAD OF AN APPROACHING COLD FRONT. THIS IS THE
LINE THAT WILL LIKELY BRING PRECIP TO THE ENTIRE AREA OVERNIGHT.
WILL CONTINUE WITH CATEGORICAL PRECIP CHANCES WITH MOST AREAS
SEEING UP TO A HALF INCH OF RAINFALL. THE PRECIP WILL END FROM
WEST TO EAST AFTER MIDNIGHT AS THE FRONT PULLS OUT. THICK CLOUDS
HAVE OVERSPREAD THE AREA AND THE THREAT FOR SEVERE WEATHER APPEARS
MINIMAL. BETTER INSTABILITY REMAINS TO THE SW AND THAT IS WHERE
ANY SEVERE WEATHER WILL LIKELY OCCUR.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY NIGHT/...
THE COLD FRONT WILL BE GONE BY DAYBREAK AND MOST OF THE PRECIP
ALONG WITH IT. COULD SEE SOME SHOWERS IN THE EAST AND SOUTH
THROUGH MIDDAY BUT AFTER THAT IT SHOULD BE TOO DRY FOR MORE
PRECIP. 850 MB TEMPS WILL DIP TO AROUND PLUS 8 BY FRIDAY EVENING
SO THIS WILL BE A COLD AIRMASS. WILL LIKELY SEE A FAIR AMOUNT OF
LAKE EFFECT STATO CU THROUGH SATURDAY. SOME INDICATION FROM THE
MODELS OF ANOTHER WEAK FRONT APPROACHING FROM THE NORTH LATE
SUNDAY AND SUNDAY NIGHT. WILL GO WITH A VERY SMALL MENTION OF
SHOWERS IN THE FAR NORTH BUT REALLY DON`T THINK THIS WILL BE A BIG
DEAL. TEMPS WILL AVERAGE WELL BELOW NORMAL AND LATER SHIFTS WILL
HAVE TO WATCH FOR POSSIBLE 40S FOR LOWS SUNDAY MORNING. HAVE USED
A BLEND OF GUIDANCE DURING THE PERIOD.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
INITIALLY LONG RANGE PART OF FORECAST SHOULD START OFF COOL AND
SOMEWHAT CLOUD. THE BIG QUESTION IS WHETHER THE UPPER TROF OVER THE
AREA WILL CAUSE ENOUGH FORCING TO PRODUCE A FEW SHRA...ESPECIALLY IN
THE SNOWBELT OR WHETHER SURFACE HIGH PRESSURE WILL KEEP THINGS DRY.
PREFERENCE IS TO CARRY AT LEAST A SLIGHT CHANCE FOR THE NE PART OF
THE AREA MON THEN GO DRY TUE AS THE UPPER TROF WEAKENS AND SHIFT
EAST.
WED LOOKS DRY AS TEMPS WARM BACK TO NORMAL. THE MODELS DIFFER BY THU
SO MUCH GREATER UNCERTAINTY IN OVERALL FORECAST. THUS FORECAST WILL
LARGELY BE INFLUENCED BY BEST COLLABORATION WITH SURROUNDING WFO`S.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
MODELS REMAIN ON TRACK IN MOVING A COLD FRONT ACROSS THE TAF SITES
TONIGHT. PROBLEM IS THAT CURRENT BAND OF CONVECTION WITH THE FRONT
IS AHEAD OF MODEL PROJECTIONS THUS LEADING TO AN ISSUE WITH MODEL
TIMING. WILL USE BLEND OF CURRENT RADAR INFO WITH MODELS TO TIME
TSRA EAST ACROSS THE AREA. EMPHASIS WILL BE ON CURRENT RADAR FOR
WESTERN TAF SITES WITH EMPHASIS GRADUALLY SHIFTING MORE TO MODELS
FOR TAF SITES FURTHER TO THE EAST.
EXPECT SOME FOG TO OCCUR LATER TONIGHT AFTER THE RAIN BUT CLOUD
COVER AND WNW FLOW OF 5 TO 8 KNOTS SHOULD KEEP FOG MOSTLY IN THE
MVFR RANGE. FOG AND CIGS IMPROVE FRI MORNING ALTHOUGH SOME MVFR MAY
LINGER IN THE EAST THROUGH 18Z AS SOME LAKE ENHANCEMENT WILL LIKELY
TAKE PLACE. A FEW SHRA MAY ALSO LINGER AT CAK...YNG AND ERI UNTIL
MIDDAY FRI.
.OUTLOOK...MAINLY VFR SHOULD PREVAIL BUT PATCHES OF LAKE EFFECT MVFR
CLOUDS MAY BE PRESENT SAT INTO MON...ESPECIALLY AROUND THE SNOWBELT.
&&
.MARINE...
COLD FRONT WILL MOVE INTO THE CENTRAL GREAT LAKES TONIGHT. EXPECT TO
SEE SOUTHWEST WINDS TO REMAIN IN THE 10 TO 20 KNOT RANGE. HOWEVER
THE EASTERN HALF OF THE LAKE COULD SEE SLIGHTLY HIGHER FOR A COUPLE
HOURS JUST AHEAD OF THE FRONT AFTER MIDNIGHT. WILL THEN AWAIT THE
WIND SHIFT TO CLEAR LAKE ERIE NEAR OR SHORTLY AFTER SUNRISE.
NORTHWESTERLY WINDS MAY BE JUST STRONG ENOUGH WITH THE LONGER FETCH
TO PROVIDE SMALL CRAFT CONDITIONS FOR THE EASTERN HALF TO TWO THIRDS
OF THE LAKE INTO FRIDAY AFTERNOON. WILL LET THE NEXT SHIFT MONITOR
THIS POTENTIAL OVERNIGHT TO DECIDE IF WE WILL REACH THE CRITERIA.
HIGH PRESSURE WILL THEN CONTROL THE LAKE WITH A LIGHT WEST TO
NORTHWEST WIND EXPECTED THROUGH THE WEEKEND. SOUTHWESTERLY WINDS
SHOULD RETURN BY MONDAY AFTERNOON AND SHOULD PERSIST INTO TUESDAY
AHEAD OF THE NEXT COLD FRONT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KUBINA
NEAR TERM...ABE/KUBINA
SHORT TERM...KUBINA
LONG TERM...ADAMS
AVIATION...
MARINE...MULLEN
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
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 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 MORRISTOWN TN
828 PM EDT THU AUG 16 2012
.DISCUSSION...ISOLATED STRONG CONVECTION CONTINUES TO DEVELOP OVER
THE WEST HALF OF TN...WITH A COUPLE OF CELLS NOTED OVER THE SOUTHERN
PART OF THE CUMBERLAND PLATEAU ALREADY...ABOUT 3 COUNTIES WEST OF
BLEDSOE AND SEQUATCHIE COUNTIES. RUC MODEL DEVELOPS CONVECTION OVER
OUR WRN 1/4TH AREAS BEFORE 06Z...WHILE LATEST WRF RUN SPREADS
CONVECTION INTO NE PLATEAU AND EXTREME SW VA BY 10Z TO 12Z FRIDAY.
AIRMASS OVER WRN 1/2 OF TN IS MUCH MORE UNSTABLE...SO WILL WATCH THE
CONVECTION FOR NOW...BUT MAY HAVE TO ADD 20-30 PERCENT CHANCE POPS
FOR AT LEAST WRN 1/3RD IN AN EVENING UPDATE.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 69 89 67 85 65 / 10 60 50 30 30
KNOXVILLE MCGHEE TYSON AIRPORT, TN 65 87 65 83 63 / 10 60 50 30 30
OAK RIDGE, TN 65 86 64 83 62 / 10 60 50 20 20
TRI CITIES AIRPORT, TN 57 86 61 80 59 / 10 60 50 30 20
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
TG
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 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 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
1049 PM CDT THU AUG 16 2012
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND FRIDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW TODAYS COLD
FRONT NOW MOVING ACROSS LAKE MICHIGAN EARLY THIS
AFTERNOON...ATTACHED TO A SURFACE LOW OVER ONTARIO. GUSTY NORTHWEST
WINDS BEHIND THE FRONT ARE BRINGING IN A COOLER AIRMASS...AS WELL AS
A STRATO-CU DECK OVER CENTRAL AND NORTH-CENTRAL WISCONSIN. BOTH DLH
AND MQT RADARS ARE PICKING UP ON WEAK RETURNS IN THIS STRATO-CU AREA
AND EAGLE RIVER REPORTED A LIGHT SHOWER OVER THE PAST HOUR. WILL
KEEP A SHOWER MENTION FOR NORTH-CENTRAL WISCONSIN FOR THE REST OF
THE AFTERNOON. AS THE COLD AND MOIST AIR CONTINUES TO FLOW OVER THE
REGION...SHOWER CHANCES AND CLOUD COVER ARE THE MAIN FORECAST
CONCERNS.
TONIGHT...TODAYS COLD FRONT WILL MOVE EAST OVER THE EASTERN GREAT
LAKES WHILE THE BADGER STATE WILL BE BETWEEN THIS FRONT AND HIGH
PRESSURE OVER THE GREAT PLAINS. BREEZY NORTHWEST WINDS WILL
CONTINUE TO PUSH A WIDESPREAD STRATO-CU DECK ACROSS THE REGION THIS
EVENING. IN ADDITION...DELTA T/S WILL BE INCREASING TO 15C OVER
WESTERN LAKE SUPERIOR WHICH WILL ADD A LAKE EFFECT COMPONENT TO THE
CLOUD COVER OVER NORTH-CENTRAL WISCONSIN. AS A RESULT...KEPT A
CHANCE OF SHOWERS ACROSS THE NORTH THROUGH 12Z. DRIER LOW LEVEL AIR
FINALLY ARRIVES AFTER MIDNIGHT WHICH WILL ERODE THE CLOUD COVER
INCLUDING THE LAKE EFFECT BANDS. BUT LAKE EFFECT BANDS SHOULD TAKE
LONGER TO ERODE...SO KEPT MOSTLY CLOUDY CONDITIONS IN THE FORECAST
THROUGH THE NIGHT OVER NORTH-CENTRAL WISCONSIN...WHILE GOING MOSTLY
CLEAR NEARLY EVERYWHERE ELSE. BL WINDS LOOK BEEFY ENOUGH TO PREVENT
DECOUPLING...SO WENT WITH LOWS IN THE MID 40S NORTH TO LOWER 50S
NEAR LAKE MICHIGAN.
FRIDAY...CANADIAN HIGH PRESSURE WILL BE BUILDING EAST ACROSS THE
STATE OF WISCONSIN THROUGH THE DAY. PLENTY OF DRY AIR PRESENT ON
PROGGED SOUNDINGS...BUT FLOW REMAINS OUT OF THE NORTHWEST OFF OF
LAKE SUPERIOR AND THINK THIS WILL INCREASE LOW LEVEL MOISTURE MORE
THAN THE MODELS ARE SHOWING. SO LIKE THE IDEA OF THE PREVIOUS SHIFT
WHICH PORTRAY DIURNAL CU BUILD-UP BY LATE IN THE MORNING. BUT ONCE
MIXING IS ABLE TO TAP INTO THE DRIER AIR ALOFT...SHOULD SEE THE CU
DISSIPATE FAIRLY QUICKLY IN THE AFTERNOON. REMAINING COOL AND
TURNING CONSIDERABLY LESS HUMID WITH HIGHS IN THE MID 60S NORTH TO
LOW 70S SOUTH.
.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY.
NUMEROUS PERIODS OF SLIGHT CHC POPS IN THE EXTENDED DUE TO
CONTINUED MODEL DISCREPANCIES ON TIMING AND COVERAGE OF SHOWER
ACTIVITY ACROSS WISCONSIN.
...FRIDAY NIGHT THROUGH SUNDAY...
LARGE SCALE UPPER LEVEL TROUGH STALLS OVER THE EASTERN CONUS FOR
THE BEGINNING PART OF THE EXTENDED WITH SHORTWAVE ENERGY SWINGING
THROUGH THE MEAN FLOW INTO WI. MODELS CONTINUE TO HAVE TROUBLE
HANDLING THESE PIECES OF ENERGY. AGREEMENT THAT FRIDAY NIGHT WILL
REMAIN DRY WITH MANY MODELS TRENDING DOWN IN THE AMOUNT OF CLOUDS
THAT WILL FILTER INTO NORTHERN WISCONSIN OVERNIGHT. STILL THINK
THERE WILL BE ENOUGH CLOUDINESS TO KEEP OVERNIGHT TEMPS ABOVE
FROST CRITERIA...BUT WILL CONTINUE TO MONITOR SITUATION IN CASE
DECREASING CLOUD TREND CONTINUES.
A WEAK SFC FRONT WILL SLIP SOUTH THROUGH WI SATURDAY AS A 500MB
SHORTWAVE MOVES INTO THE GREAT LAKES REGION. THERE IS STILL
DISAGREEMENT BETWEEN MODELS ON HOW QUICKLY THE 500MB SHORTWAVE
DIGS INTO IL...WITH THE ECMWF BEING THE SLOWEST AND THE THE GFS
BEING THE FASTEST. GFS IS THE OUTLIER AND HAS WIDESPREAD PRECIP
BREAKING OUT BY 18Z SAT. HOWEVER... IT IS THE OUTLIER AND MODEL
CONSENSUS KEEPS PRECIP CONFINED TO NORTHERN WISCONSIN. THEREFORE
KEPT SOUTHERN PORTIONS OF THE CWA DRY WITH CHC IN NORTHERN WI.
MODELS DISAGREE FURTHER ON PRECIP CHANCES SATURDAY NIGHT. SOME
MODELS CONTINUE SHOWERS THROUGH 09Z SUN IN CENTRAL WI AND THE FOX
VALLEY...WHILE OTHERS SHUT THE PRECIP OFF AFTER SUNSET. GIVEN THE
DIURNALLY DRIVEN NATURE OF THE PRECIP AND THAT THERE IS VERY
LITTLE UPPER LEVEL DYNAMICS/FORCING TO KEEP THE SHOWERS GOING
THROUGH THE NIGHT...WILL DRY THINGS OUT BY 06Z SUNDAY.
SHOWERS SHOULD THEN DEVELOP AGAIN NEAR THE SLOW MOVING SFC FRONT
SUNDAY AFTERNOON. MODELS ARE TRENDING TOWARDS EASTERN WI SEEING
THE BEST CHCS OF SHOWERS SO INCREASED POPS TO CHC OVER THE EAST.
OTHERWISE...CONTINUED WITH THE WIDESPREAD SLIGHT CHC POPS.
...MONDAY NIGHT THROUGH WEDNESDAY...
SHOULD BE DRY MONDAY NIGHT INTO TUESDAY DUE TO A WEAK UPPER RIDGE
PASSING THROUGH WISCONSIN. A MORE SIGNIFICANT SHORT WAVE WILL
RESULT IN AT LEAST A SLIGHT CHANCE FOR SHOWERS AND THUNDERSTORMS
AROUND THE MIDDLE OF THE WEEK.
EXPECT BELOW NORMAL TEMPERATURES THROUGH MONDAY WITH A WARMER
WEATHER TUESDAY AND WEDNESDAY IN SOUTHERLY FLOW AHEAD OF AN
APPROACHING SURFACE SYSTEM OVER THE PLAINS.
&&
.AVIATION...SCT-BKN STRATOCUMULUS WITH VFR CIGS COVERED MUCH OF
THE FORECAST AREA LATE THIS EVG...BUT CLEARING HAD OCCURRED OVER
NORTHWEST AND WEST CENTRAL WI. SCT SHOWERS WERE ONGOING OVER FAR
NORTHERN WI...WITH ISOLD SHOWERS LINGERING ELSEWHERE. THE SHOWERS
AND CLOUDS SHOULD DECREASE OVERNIGHT. VFR CONDITIONS SHOULD
PREVAIL THROUGH THE PERIOD...WITH THE EXCEPTION OF ISOLD MVFR
CONDITIONS IN FAR NC WI OVERNIGHT...MAINLY NORTH OF THE RHI TAF
SITE.
KIECKBUSCH
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
636 PM CDT THU AUG 16 2012
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND FRIDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW TODAYS COLD
FRONT NOW MOVING ACROSS LAKE MICHIGAN EARLY THIS
AFTERNOON...ATTACHED TO A SURFACE LOW OVER ONTARIO. GUSTY NORTHWEST
WINDS BEHIND THE FRONT ARE BRINGING IN A COOLER AIRMASS...AS WELL AS
A STRATO-CU DECK OVER CENTRAL AND NORTH-CENTRAL WISCONSIN. BOTH DLH
AND MQT RADARS ARE PICKING UP ON WEAK RETURNS IN THIS STRATO-CU AREA
AND EAGLE RIVER REPORTED A LIGHT SHOWER OVER THE PAST HOUR. WILL
KEEP A SHOWER MENTION FOR NORTH-CENTRAL WISCONSIN FOR THE REST OF
THE AFTERNOON. AS THE COLD AND MOIST AIR CONTINUES TO FLOW OVER THE
REGION...SHOWER CHANCES AND CLOUD COVER ARE THE MAIN FORECAST
CONCERNS.
TONIGHT...TODAYS COLD FRONT WILL MOVE EAST OVER THE EASTERN GREAT
LAKES WHILE THE BADGER STATE WILL BE BETWEEN THIS FRONT AND HIGH
PRESSURE OVER THE GREAT PLAINS. BREEZY NORTHWEST WINDS WILL
CONTINUE TO PUSH A WIDESPREAD STRATO-CU DECK ACROSS THE REGION THIS
EVENING. IN ADDITION...DELTA T/S WILL BE INCREASING TO 15C OVER
WESTERN LAKE SUPERIOR WHICH WILL ADD A LAKE EFFECT COMPONENT TO THE
CLOUD COVER OVER NORTH-CENTRAL WISCONSIN. AS A RESULT...KEPT A
CHANCE OF SHOWERS ACROSS THE NORTH THROUGH 12Z. DRIER LOW LEVEL AIR
FINALLY ARRIVES AFTER MIDNIGHT WHICH WILL ERODE THE CLOUD COVER
INCLUDING THE LAKE EFFECT BANDS. BUT LAKE EFFECT BANDS SHOULD TAKE
LONGER TO ERODE...SO KEPT MOSTLY CLOUDY CONDITIONS IN THE FORECAST
THROUGH THE NIGHT OVER NORTH-CENTRAL WISCONSIN...WHILE GOING MOSTLY
CLEAR NEARLY EVERYWHERE ELSE. BL WINDS LOOK BEEFY ENOUGH TO PREVENT
DECOUPLING...SO WENT WITH LOWS IN THE MID 40S NORTH TO LOWER 50S
NEAR LAKE MICHIGAN.
FRIDAY...CANADIAN HIGH PRESSURE WILL BE BUILDING EAST ACROSS THE
STATE OF WISCONSIN THROUGH THE DAY. PLENTY OF DRY AIR PRESENT ON
PROGGED SOUNDINGS...BUT FLOW REMAINS OUT OF THE NORTHWEST OFF OF
LAKE SUPERIOR AND THINK THIS WILL INCREASE LOW LEVEL MOISTURE MORE
THAN THE MODELS ARE SHOWING. SO LIKE THE IDEA OF THE PREVIOUS SHIFT
WHICH PORTRAY DIURNAL CU BUILD-UP BY LATE IN THE MORNING. BUT ONCE
MIXING IS ABLE TO TAP INTO THE DRIER AIR ALOFT...SHOULD SEE THE CU
DISSIPATE FAIRLY QUICKLY IN THE AFTERNOON. REMAINING COOL AND
TURNING CONSIDERABLY LESS HUMID WITH HIGHS IN THE MID 60S NORTH TO
LOW 70S SOUTH.
.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY.
NUMEROUS PERIODS OF SLIGHT CHC POPS IN THE EXTENDED DUE TO
CONTINUED MODEL DISCREPANCIES ON TIMING AND COVERAGE OF SHOWER
ACTIVITY ACROSS WISCONSIN.
...FRIDAY NIGHT THROUGH SUNDAY...
LARGE SCALE UPPER LEVEL TROUGH STALLS OVER THE EASTERN CONUS FOR
THE BEGINNING PART OF THE EXTENDED WITH SHORTWAVE ENERGY SWINGING
THROUGH THE MEAN FLOW INTO WI. MODELS CONTINUE TO HAVE TROUBLE
HANDLING THESE PIECES OF ENERGY. AGREEMENT THAT FRIDAY NIGHT WILL
REMAIN DRY WITH MANY MODELS TRENDING DOWN IN THE AMOUNT OF CLOUDS
THAT WILL FILTER INTO NORTHERN WISCONSIN OVERNIGHT. STILL THINK
THERE WILL BE ENOUGH CLOUDINESS TO KEEP OVERNIGHT TEMPS ABOVE
FROST CRITERIA...BUT WILL CONTINUE TO MONITOR SITUATION IN CASE
DECREASING CLOUD TREND CONTINUES.
A WEAK SFC FRONT WILL SLIP SOUTH THROUGH WI SATURDAY AS A 500MB
SHORTWAVE MOVES INTO THE GREAT LAKES REGION. THERE IS STILL
DISAGREEMENT BETWEEN MODELS ON HOW QUICKLY THE 500MB SHORTWAVE
DIGS INTO IL...WITH THE ECMWF BEING THE SLOWEST AND THE THE GFS
BEING THE FASTEST. GFS IS THE OUTLIER AND HAS WIDESPREAD PRECIP
BREAKING OUT BY 18Z SAT. HOWEVER... IT IS THE OUTLIER AND MODEL
CONSENSUS KEEPS PRECIP CONFINED TO NORTHERN WISCONSIN. THEREFORE
KEPT SOUTHERN PORTIONS OF THE CWA DRY WITH CHC IN NORTHERN WI.
MODELS DISAGREE FURTHER ON PRECIP CHANCES SATURDAY NIGHT. SOME
MODELS CONTINUE SHOWERS THROUGH 09Z SUN IN CENTRAL WI AND THE FOX
VALLEY...WHILE OTHERS SHUT THE PRECIP OFF AFTER SUNSET. GIVEN THE
DIURNALLY DRIVEN NATURE OF THE PRECIP AND THAT THERE IS VERY
LITTLE UPPER LEVEL DYNAMICS/FORCING TO KEEP THE SHOWERS GOING
THROUGH THE NIGHT...WILL DRY THINGS OUT BY 06Z SUNDAY.
SHOWERS SHOULD THEN DEVELOP AGAIN NEAR THE SLOW MOVING SFC FRONT
SUNDAY AFTERNOON. MODELS ARE TRENDING TOWARDS EASTERN WI SEEING
THE BEST CHCS OF SHOWERS SO INCREASED POPS TO CHC OVER THE EAST.
OTHERWISE...CONTINUED WITH THE WIDESPREAD SLIGHT CHC POPS.
...MONDAY NIGHT THROUGH WEDNESDAY...
SHOULD BE DRY MONDAY NIGHT INTO TUESDAY DUE TO A WEAK UPPER RIDGE
PASSING THROUGH WISCONSIN. A MORE SIGNIFICANT SHORT WAVE WILL
RESULT IN AT LEAST A SLIGHT CHANCE FOR SHOWERS AND THUNDERSTORMS
AROUND THE MIDDLE OF THE WEEK.
EXPECT BELOW NORMAL TEMPERATURES THROUGH MONDAY WITH A WARMER
WEATHER TUESDAY AND WEDNESDAY IN SOUTHERLY FLOW AHEAD OF AN
APPROACHING SURFACE SYSTEM OVER THE PLAINS.
&&
.AVIATION...STRATOCUMULUS WITH VFR CIGS COVERED MUCH OF THE
FORECAST AREA EARLY THIS EVG. THE CLOUD COVER WAS MORE SCATTERED
OVER THE EASTERN COUNTIES...DUE TO DOWNSLOPING NW WINDS. CLEARING
SKIES OVER MN SHOULD SPREAD ACROSS THE RGN AFTER MIDNIGHT...
ALTHOUGH COLD NW FLOW OFF LAKE SUPERIOR WILL RESULT IN SOME LAKE
EFFECT CLOUDS IN NC WI THROUGH THE NIGHT. CURRENT LIGHT SHOWER
ACTIVITY OVER NORTHERN WI SHOULD DECREASE BY SUNSET...BUT A FEW
LAKE-EFFECT SHOWERS MAY CONTINUE OVER FAR NC WI OVERNIGHT. VFR
CONDITIONS SHOULD PREVAIL...OUTSIDE OF ISOLD MVFR CONDITIONS IN
FAR NC WI...MAINLY NORTH OF THE RHI TAF SITE.
KIECKBUSCH
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
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
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 TUCSON AZ
915 PM MST THU AUG 16 2012
.SYNOPSIS...AMPLE MOISTURE WILL PROVIDE SCATTERED SHOWERS AND
THUNDERSTORMS INTO THE WEEKEND. BELOW NORMAL DAYTIME TEMPERATURES
WILL ALSO CONTINUE FRIDAY AND SATURDAY. THE DAILY CYCLE OF MAINLY
AFTERNOON AND EVENING THUNDERSTORMS WILL RETURN NEXT WEEK ALONG WITH
NEAR NORMAL DAYTIME TEMPERATURES.
&&
.DISCUSSION...SCATTERED SHOWERS AND THUNDERSTORMS ONGOING ACROSS NRN
GREENLEE/GRAHAM/NRN COCHISE COUNTIES. ISOLATED SHOWERS PRODUCING
VERY LIGHT RAIN WERE WEAKENING ACROSS WRN/CENTRAL PIMA COUNTY. IR
SATELLITE IMAGERY INDICATED CLOUD TOPS TO GENERALLY BE WARMING
ACROSS SE AZ DURING THE PAST 1-2 HOURS. HOWEVER...CLOUD TOPS WERE
COOLING NE OF TUCSON ACROSS NRN GREENLEE/GRAHAM COUNTIES.
BASED ON SATELLITE/RADAR TRENDS AS WELL AS THE 17/00Z NAM AND 17/00Z
RUC HRRR...HAVE OPTED FOR SCATTERED SHOWERS/TSTMS THE REST OF
TONIGHT ACROSS GREENLEE/GRAHAM/NRN COCHISE COUNTIES. SCATTERED
SHOWERS AND ISOLATED TSTMS EXPECTED TO OCCUR ELSEWHERE. THE LEAST
FAVORED AREA FOR PRECIP THE REST OF TONIGHT APPEARS TO BE ACROSS
WRN/CENTRAL PIMA COUNTY.
17/00Z RUC HRRR HAS BEEN CONSISTENT WITH PREVIOUS SOLUTIONS IN
DEVELOPING SHOWERS SHORTLY AFTER MIDNIGHT ACROSS THE TUCSON METRO
AREA. 17/00Z NAM HAS BEEN CONSISTENT WITH DEPICTING THE BEST CHANCE
OF PRECIP FRI TO OCCUR FROM TUCSON NWD/EWD WITH LESSER CHANCES OF
PRECIP SW OF TUCSON. LOCALLY HEAVY RAINFALL MAY OCCUR FRI AS STORM
MOTIONS ARE EXPECTED TO BE FAIRLY SLOW GIVEN LIGHT STEERING FLOW.
OTHERWISE...MOSTLY CLOUDY TO CLOUDY SKIES ON TAP THE REST OF TONIGHT
AND FRI. HIGH TEMPS FRI EXPECTED TO BE ABOUT 5-10 DEGS F OR SO BELOW
NORMAL.
&&
.PREV DISCUSSION...FOR FRIDAY INTO SATURDAY...STILL PLENTY OF
MOISTURE WITH HIGH PRESSURE PARKED TO OUR NORTH. THERE IS A
POTENTIAL FOR THESE TO BE VERY ACTIVE STORM DAYS...THOUGH THIS WILL
BE DEPENDENT AGAIN ON CLOUD COVER AND RESULTING DAYTIME HEATING.
MOISTURE VALUES WILL GRADUALLY TREND DOWN NEXT WEEK AS THE HIGH
PRESSURE ALOFT NUDGES SOUTHWARD. THIS WILL RESULT IN MORE OF A
STANDARD MONSOON PATTERN FORECAST. DAYTIME TEMPERATURES WILL REMAIN
BELOW NORMAL THROUGH THE WEEKEND WITH NEAR NORMAL DAYTIME
TEMPERATURES NEXT WEEK.
&&
.AVIATION...SCT SHRA AND ISOLD -TSRA THE REST OF TONIGHT. SCT-NMRS
SHRA/TSRA FRIDAY AND FRIDAY EVENING. WIND GUSTS APPROACHING 40 KTS
WITH THE STRONGEST TSRA FRIDAY AFTERNOON. OTHERWISE...CLOUD DECKS
AROUND 8-12K FT AGL AND SURFACE WIND GENERALLY LESS THAN 10 KTS THRU
FRIDAY EVENING OR 18/06Z. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.
&&
.FIRE WEATHER...EXPECT SCATTERED SHOWERS AND THUNDERSTORMS AND BELOW
NORMAL DAYTIME TEMPERATURES THROUGH THE WEEKEND. THEREAFTER...
SCATTERED MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS
WILL OCCUR EARLY NEXT WEEK.
&&
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE
&&
$$
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
407 AM EDT FRI AUG 17 2012
.DISCUSSION...
...FAVORABLE WINDS AND SEAS THIS WEEKEND BUT OFFSHORE MOVING STORMS
WILL REMAIN A CONCERN FOR BOATERS...
CURRENT...SURFACE RIDGE AXIS REMAINS NEAR LAKE OKEECHOBEE...ALTHOUGH
IT APPEARS TO HAVE SLIPPED TOWARD THE SOUTH END OF THE LAKE GIVEN
THE SW WINDS NOW IN PLACE AT KOBE AND SPGF1. HOWEVER...SFC METAR AND
PROFILER DATA DON`T SUGGEST THAT THE FLOW IS ANY MORE VEERED COMPARED
TO THE THIS TIME LAST NIGHT. A COUPLE OF SHOWERS/TS POPPED UP AFTER
MIDNIGHT IN A FEW POCKETS OF RESIDUAL INSTABILITY ACROSS THE NRN CWA
...NOT AT ALL SURPRISING IN THE SULTRY AUGUST AIR MASS. WATERVAPOR
IMAGERY AND RUC ANLYS FIELDS SHOW THE BASE OF THE BROAD ERN CONUS
MID/UPPER LEVEL TROUGH ACROSS SOUTH GA/NORTH FL...WITH A WELL-DEFINED
SHORT WAVE TROUGH EVIDENT OVER CTRL AL/GA DROPPING SEWD.
TODAY/TONIGHT...MODEL GUIDANCE IS SHOWING SOME STRENGTHENING OF THE
LOW TO MID LEVEL FLOW OVER THE PENINSULA TODAY...WITH THE 12KM NAM
A LITTLE MORE AGGRESSIVE TOWARD THIS END. WITH THE AFOREMENTIONED H50
SHORT WAVE DROPPING SOUTHWARD THIS SEEMS REASONABLE. PWATS WILL STAY
CLOSE TO 2.0" SO MOISTURE IS NO PROBLEM. WHILE THE ENHANCED LIFT
ASCD WITH THE VORT TO THE NORTH SHOULD PRODUCE ENHANCED LIFT THERE
IT IS ALSO PRODUCING A DECENT SWATH OF MID/UPPER DEBRIS CLOUDS AS
WELL. EXTENT OF MID/UPPER CLOUDINESS SNEAKING SOUTHWARD TOWARD OUR
NORTHERN ZONES EARLY THIS MORNING WILL BE SOMETHING TO KEEP TABS ON
AS IT COULD PROVIDE FOCUS FOR EARLY STORMS IN AREA OF DIFFERENTIAL
HEATING. MAINLY BECAUSE OF THE TROUGH TO THE NORTH...HAVE MADE TWEAK
TO BUMP POPS OVER NORTHERN COUNTIES TO 50 PCT TO MATCH FAVORED EAST
COASTAL AREAS. MAX TEMPS SHOULD AVERAGE ABOUT 1-3F ABOVE NORMAL.
EAST COASTAL COUNTIES AGAIN FAVORED SLIGHTLY FOR EVENING POPS (40 VS
30 REST OF CWA) GIVEN THE SLIGHT FASTER AND MORE VEERED WESTERLY
H85-H50 STEERING WINDS.
SATURDAY...UPPER TROUGHING OVER THE EASTERN CONUS WILL KEEP THE
ATLC RIDGE SUPPRESSED TO OUR SOUTH. THIS WILL MAINTAIN A STRONGER
OFFSHORE (W/SW) FLOW IN THE LOW AND MID LEVELS...DELAYING OR
PROHIBITING THE EAST COAST SEA BREEZE FROM FORMING AND ALLOWING
TEMPERATURES TO CLIMB A COUPLE DEGREES HIGHER AT THE COAST. THE
POSSIBLE LACK OF A SEA BREEZE BOUNDARY NORTH OF THE CAPE WOULD ACT
TO REDUCE COVERAGE AND INTENSITY OF STORMS IN VOLUSIA. BUT DO
EXPECT A SEA BREEZE TO FORM SOUTH OF THE CAPE WHICH SHOULD PROVIDE
A FOCUS FOR LATE AFTN/EARLY EVENING STORMS...SOME STRONG.
SUN-MON...ATLANTIC RIDGE IS FORECAST TO BUILD BACK A LITTLE BIT
ACROSS THE FL PENINSULA WHICH WILL REDUCE THE OFFSHORE FLOW AND
ALLOW THE SEA BREEZE TO FORM A LITTLE EARLIER. GFS SHOWS SOME
SLIGHT DRYING LIFTING NORTH ACROSS THE AREA ACCOMPANYING THE RIDGE
AXIS. THIS MAY DELAY ONSET OF STORMS A BIT BUT STEERING FLOW IS
FORECAST TO REMAIN OUT OF THE SW WHICH WILL FAVOR THE EAST SIDE OF
THE PENINSULA. SO WILL MAINTAIN SCATTERED STORM COVERAGE (AROUND
40 PERCENT).
TUE-THU...WILL MAINTAIN SCATTERED POPS BUT GFS SHOWS SOME MORE
SIGNIFICANT DRYING LIFTING NORTH INTO SOUTH FL WHICH COULD REDUCE
STORM COVERAGE ALONG THE TREASURE COAST WED AS DEEPER ONSHORE FLOW
DEVELOPS. DEEPER MOISTURE WILL CONTINUE TO EXIST ORLANDO NORTH
THU...WITH DRIER AIR SOUTH OF ORLANDO LIMITING RAIN CHANCES
SOMEWHAT.
&&
.AVIATION...
MADE SOME ADJUSTMENTS TO THE 06Z TAF PACKAGE TO SHOW A LITTLE
EARLIER TIMING FOR THE SERN AND NWRN AERODROMES (BEST CHANCE 18Z-
22Z) VERSUS THE CENTRAL SITES (20Z-23Z) AS HAS BEEN THE CASE FOR
MOST DAYS DURING THIS REGIME. IFR CIGS/VSBYS IN TS WITH G30KT OR
HIGHER IN SEVERAL STRONGER CELLS TODAY. STORM MOTION LOOKS TO BE
FROM ABOUT 270 AT A SOLID 12-17KT (15-20MPH).
&&
.MARINE...
SWAN HIGH BIAS CONTINUES TO PAINT SEA HGT FORECAST ABOUT 0.5 TO
1.0FT HIGHER THAN REALITY IN OFFSHORE FLOW REGIME. HAVE KEPT SEAS
1-2FT TODAY/EARLY TONIGHT WITH SLIGHT INCREASE WELL OFFSHORE AFTER
MIDNIGHT.
PERSISTENT TROFFING PATTERN OVER THE ERN CONUS WILL KEEP THE ATLC
RIDGE AXIS SUPPRESSED OVER THE S HALF OF THE FL PENINSULA INTO NEXT
WEEK. THIS WILL GENERATE LIGHT TO GENTLE W/SW FLOW...TURNING
ONSHORE EACH AFTN AS THE EAST COAST SEA BREEZE FORMS AND PUSHES
INLAND. THERE SHOULD BE GENTLE TO MODERATE NIGHTTIME BREEZE DUE
TO NOCTURNAL WIND ENHANCEMENT MAINLY OVER THE OPEN ATLC. SEAS 1-2FT
NEARSHORE AND 2-3FT OFFSHORE. PRIMARY CONCERN FOR BOATERS WILL BE
LATE AFTN/EARLY EVE STORMS MOVING OFFSHORE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 92 75 92 76 / 50 40 50 40
MCO 94 75 93 75 / 40 30 40 30
MLB 91 75 91 75 / 50 40 50 40
VRB 90 74 92 74 / 50 40 50 40
LEE 93 76 93 77 / 50 30 40 30
SFB 94 76 94 77 / 50 30 40 30
ORL 94 76 93 77 / 40 30 40 30
FPR 90 74 91 74 / 40 30 40 30
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...CRISTALDI
LONG TERM....KELLY
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
401 AM EDT FRI AUG 17 2012
.SHORT TERM /TODAY THROUGH SATURDAY/...
THE CONVECTIVE REMNANTS OF AN MCS IS PUSHING ACROSS NORTH GA EARLY
THIS MORNING. EXPECT CURRENT WEAKENING TREND TO CONTINUE...SPREADING
MAINLY MID LEVEL CLOUDINESS AND SPOTTY LIGHT RAIN SHOWERS INTO THE
ATLANTA METRO AREA BY 5-6 AM THIS MORNING. ALTHO CANNOT RULE OUT A
FEW RUMBLES OF THUNDER THIS MORNING...EXPECT SPOTTY LIGHT RAIN TO
BE THE MAIN PRECIP TYPE IN ATLANTA THIS MORNING.
OF GREATER CONCERN IS AN APPROACHING COLD FRONT THAT IS EXPECTED
TO PUSH INTO NORTH GEORGIA LATER THIS AFTERNOON. GFS AND NAM SHOW
A SERIES OF STRONG UPPER VORT MAXES TRAVERSING NORTH GEORGIA
DURING DAYTIME HEATING. THIS COUPLED WITH THE FRONT SHOULD RESULT
IN WIDESPREAD SHOWERS AND THUNDERSTORMS PUSHING INTO NORTH GEORGIA
TODAY...WITH SCATTERED CONVECTION POSSIBLY SPREADING INTO PARTS
OF CENTRAL GEORGIA AS WELL. RESIDUAL CLOUD COVER FROM THIS
MORNINGS DISSIPATING MCS SHOULD HELP HOLD TEMPERATURES AND
INSTABILITIES DOWN A BIT TODAY. HOWEVER...TIMING OF THE UPPER
VORT MAX DURING MAX HEATING...ALONG WITH FRONTAL FORCING...ALL
SUGGEST THE POTENTIAL FOR ISOLATED STRONG TO SEVERE STORMS ACROSS
PARTS OF NORTH GEORGIA LATER THIS AFTERNOON AND EARLY EVENING. SPC
CONTINUES TO PLACE MUCH OF NORTH GEORGIA IN A SLIGHT RISK AREA
TODAY...GENERALLY ALONG AND NORTH OF A LAGRANGE TO COVINGTON TO
ATHENS LINE. THE MAIN STORM THREATS WILL BE DAMAGING WIND AND
MARGINAL SIZED HAIL. LOCALLY HEAVY RAIN IS ALSO A CONCERN WITH
TRAINING CELLS AHEAD OF THE FRONT. THE UPPER DISTURBANCES PUSH
EAST BY MIDNIGHT...SO EXPECT THE ASSOCIATED CONVECTION AHEAD OF
THE FRONT TO GREATLY DIMINISH BY THEN...ESPECIALLY WITH LOSS OF
DAYTIME HEATING.
THE FRONT STALLS ACROSS CENTRAL GEORGIA ON SATURDAY...SO WILL
SHOW THE GREATER RAIN CHANCES THERE SATURDAY AFTERNOON. MARGINAL
INSTABILITIES AND LACK OF UPPER SUPPORT SHOULD HELP HOLD STORM
DEVELOPMENT BELOW SEVERE LIMITS ON SATURDAY.
OTHERWISE...STARTED WITH A MAV AND MET BLEND FOR TEMPS THROUGH THE
SHORT TERM...THEN LEANED TOWARD THE COOLER MET HIGHS FOR TODAY
WITH RESIDUAL CLOUDINESS...THEN WARMER MAV HIGHS ON SATURDAY WITH
LESS CLOUDS AND ONLY ISOLATED TO SCATTERED CONVECTION EXPECTED.
39
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
CWA REMAINS IN LONGWAVE TROUGH AT THE BEGINNING OF THE LONG TERM.
MEANWHILE AT THE SFC...FRONT THAT MOVES THROUGH IN THE SHORT TERM
REMAINS SITUATED ACROSS THE SOUTHERN HALF OF THE STATE. THIS
PATTERN WILL DOMINATE THE LONG TERM. WITH FRONT MEANDERING AROUND
CENTRAL GEORGIA...BEST CHANCES OF RAIN THROUGH THE LONG TERM WILL
REMAIN ACROSS THE SOUTHERN HALF OF THE CWA. IN ADDITION WILL SEE
WEAK DISTURBANCES MOVE ALONG THE FRONT AS IT REMAINS STATIONARY.
GFS SHOWS THE BEST VORT MAX TO MOVE ALONG THE FRONT ON MONDAY AND
THIS WILL HELP TO REINFORCE CHANCE OF POPS. INITIALLY OVER THE
WEEKEND...POPS ARE ON THE LOWER SIDE OF GUIDANCE AS IT APPEARS MAV
IS OVER DOING POPS...WHEREAS LATER IN THE LONG TERM...POPS ARE
CLOSER TO GUIDANCE.
11
&&
.AVIATION...
06Z UPDATE...
VFR CONDITIONS EXPECTED TO PREVAIL. HOWEVER... A LINE OF ONGOING
CONVECTION IN TN WILL PUSH INTO NW GA BY 06-07Z...AND IF HOLDS
TOGETHER...COULD SPREAD AT LEAST MID LEVEL CIGS AND -SHRA`S INTO
THE ATLANTA METRO AREA AROUND 08-10Z THIS MORNING. EXPECT A
WEAKENING TREND TO CONTINUE AND HRRR MODEL INDICATES ONLY SPOTTY
-RA WILL MAKE IT INTO THE ATLANTA AREA... SO WILL SHOW VCSH AT
09-10Z FOR NOW. THE GREATER CONVECTIVE THREAT WILL BEGIN AT ATL
AROUND 16Z AND CONTINUE THROUGH THE AFTERNOON- EARLY EVENING HOURS
WHEN A COLD FRONT PUSHES INTO FAR NORTH GA. EXPECT CONVECTION TO
GREATLY DIMINISH BY 04-06Z TONIGHT AS THE DRIVING UPPER SHORT WAVE
PUSHES EAST. WET GROUNDS SUGGEST POTENTIAL FOR IFR CIGS BY 09-10Z
SAT MORNING. LIGHT WNW WINDS THIS MORNING WILL BE MORE WESTERLY 10
KTS OR LESS BY AFTN.
//ATL CONFIDENCE...06Z UPDATE...
HIGH CONFIDENCE ALL ELEMENTS EXCEPT MEDIUM ON TIMING AND LOCATION OF
CONVECTION TODAY.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 87 69 89 67 / 50 40 30 20
ATLANTA 86 70 86 69 / 70 40 30 20
BLAIRSVILLE 80 66 81 62 / 80 50 20 10
CARTERSVILLE 86 69 85 64 / 90 50 20 20
COLUMBUS 91 72 89 70 / 60 40 30 20
GAINESVILLE 86 70 86 67 / 70 50 30 20
MACON 92 71 91 71 / 40 30 40 30
ROME 87 69 88 63 / 90 50 20 10
PEACHTREE CITY 87 69 86 66 / 70 40 30 20
VIDALIA 93 73 91 73 / 40 30 40 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...39
LONG TERM....11
AVIATION...39
AREA FORECAST DISCUSSION...UPDATED FOR AVIATION
NWS PEACHTREE CITY GA
138 AM EDT FRI AUG 17 2012
.UPDATE...
/ISSUED AT 1020 PM EDT THU AUG 16 2012/
HAVE UPDATED FORECAST TO ADD SLIGHT CHANCE OF THUNDERSTORMS OVER
MUCH OF NORTH GEORGIA TONIGHT...NORTH OF AN ATLANTA TO ATHENS LINE
FOR NOW. THERE ARE A FEW STORMS DEVELOPING AHEAD OF THE MCS MOVING
THROUGH TENNESSEE AND KENTUCKY. WILL CONTINUE TO WATCH AND SEE HOW
THE CONVECTION DEVELOPS. NO OTHER CHANGES AT THIS TIME.
41
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
/ISSUED AT 317 PM EDT THU AUG 16 2012/
STATIONARY FRONT ACROSS CENTRAL GA WITH BEST INSTABILITY ACROSS THE
SOUTHERN COUNTIES. THAT IS WHERE THE BEST CHANCES FOR SHOWERS AND
THUNDERSTORMS WILL BE INTO THE MID EVENING HOURS. A CONCERN TO WATCH
FOR IS SHORT WAVES IN THE UPPER FLOW COMING FROM MS/AL THAT COULD
AFFECT THE WESTERN CWA THIS EVENING.
THE MAIN CONCERN WILL THEN BE A COLD FRONT APPROACHING N GA FRIDAY
AFTERNOON. GFS/NAM THEN DIFFER HOW FAR TO TAKE THE FRONT INTO THE
AREA WITH THE GFS MOVING THE FRONT TO CENTRAL GA AT DAYS END FRIDAY
AND THE NAM MOVING THE FRONT INTO N GA. THINK THE NAM MOVEMENT IS
BETTER AND THE HIGHER POPS FROM THE NAM MOS MORE IN LINE THAN THE
LOWER GFS MOS POPS. A FLAIR UP OF SHOWERS AND THUNDERSTORMS CAN BE
EXPECTED FRIDAY WITH THE APPROACH OF THE FRONT AND SPC HAS
HIGH-LIGHTED MAINLY N GA FOR A SLIGHT RISK OF SEVERE THUNDERSTORMS.
THIS IS PARTLY DUE TO A SHORT WAVE AIDING THE STORM DEVELOPMENT.
THE FRONT WILL LIKELY BECOME STATIONARY FRIDAY NIGHT ACROSS N GA.
WHILE SHOWER AND THUNDERSTORM ACTIVITY WILL DIMINISH...CHANCES WILL
REMAIN IN THE FORECAST ALL NIGHT.
FORECAST LOW TEMPERATURES RUNNING NEAR NORMAL TONIGHT AND FRIDAY
NIGHT. FORECAST HIGH TEMPERATURES RUNNING NEAR TO SLIGHTLY BELOW
NORMAL FOR FRIDAY AND WENT WITH THE COOLER MET MOS HIGHS. THESE
TEMPERATURES COULD BE TOO COOL FOR PORTIONS OF THE SE CWA.
OVERALL CONFIDENCE IS MEDIUM.
BDL
.LONG TERM /SATURDAY THROUGH THURSDAY/...
/ISSUED AT 317 PM EDT THU AUG 16 2012/
AFOREMENTIONED FRONT WILL BE WORKING ITS WAY THROUGH THE AREA
SATURDAY AND SUNDAY AS THE STRONG UPPER TROUGH DIGS INTO THE
EASTERN HALF OF THE COUNTRY. VARIOUS SHORTWAVES ROUNDING THE BASE
OF THE TROUGH ALONG WITH SOUTHWEST FLOW ALOFT AND TROPICAL
CONNECTION FROM THE TROPICAL WAVE OVER THE BAY OF CAMPECHE WILL
KEEP DIFFERENT WAVES OF CONVECTION IN THE AREA THROUGH THE
EXTENDED. 12Z GFS NO LONGER TRIES TO CUTOFF A SHORTWAVE MIDWEEK
WHEREAS THE ECMWF IS STILL DOING THIS. WITH THE CUTOFF...THE ECMWF
DEVELOPS A MORE PROGRESSIVE SYSTEM AND PUSHES THE TROUGH UP INTO
SOUTHEAST CANADA WITH RIDGING BUILDING INTO THE SOUTH...WHEREAS
THE GFS KEEPS THE TROUGH AS THE DOMINANT FEATURE...WHICH WILL
IMPACT WHICH DAYS NEXT WEEK HAVE PRECIP. GUIDANCE IS ALSO HINTING
AT A SLIGHTLY WARMER SOLUTION THIS TIME AROUND. WITH ALL THESE
CHANGES...ALBEIT MINOR...HAVE MADE NO CHANGES TO THE FORECAST
BEYOND 48 HOURS GIVEN THE UNCERTAINTY. SEE PREVIOUS DISCUSSION
BELOW.
TDP
&&
.AVIATION...
06Z UPDATE...
VFR CONDITIONS EXPECTED TO PREVAIL. HOWEVER... A LINE OF ONGOING
CONVECTION IN TN WILL PUSH INTO NW GA BY 06-07Z...AND IF HOLDS
TOGETHER...COULD SPREAD AT LEAST MID LEVEL CIGS AND -SHRA`S INTO THE
ATLANTA METRO AREA AROUND 08-10Z THIS MORNING. EXPECT A WEAKENING
TREND TO CONTINUE AND HRRR MODEL INDICATES ONLY SPOTTY -RA WILL MAKE
IT INTO THE ATLANTA AREA... SO WILL SHOW VCSH AT 09-10Z FOR NOW. THE
GREATER CONVECTIVE THREAT WILL BEGIN AT ATL AROUND 16Z AND CONTINUE
THROUGH THE AFTERNOON-EARLY EVENING HOURS WHEN A COLD FRONT PUSHES
INTO FAR NORTH GA. EXPECT CONVECTION TO GREATLY DIMINISH BY 04-06Z
TONIGHT AS THE DRIVING UPPER SHORT WAVE PUSHES EAST. WET GROUNDS
SUGGEST POTENTIAL FOR IFR CIGS BY 09-10Z SAT MORNING. LIGHT WNW
WINDS THIS MORNING WILL BE MORE WESTERLY 10 KTS OR LESS BY AFTN.
//ATL CONFIDENCE...06Z UPDATE...
HIGH CONFIDENCE ALL ELEMENTS EXCEPT MEDIUM ON TIMING AND LOCATION OF
CONVECTION TODAY.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 68 89 69 88 / 10 50 40 40
ATLANTA 72 87 71 86 / 10 70 40 40
BLAIRSVILLE 64 80 67 81 / 10 80 50 40
CARTERSVILLE 66 86 68 86 / 20 90 50 40
COLUMBUS 72 90 73 88 / 10 40 40 50
GAINESVILLE 69 86 70 85 / 10 70 40 40
MACON 72 91 71 90 / 10 50 30 50
ROME 68 87 69 87 / 20 90 60 40
PEACHTREE CITY 67 87 68 86 / 10 60 40 40
VIDALIA 73 94 73 92 / 20 30 20 50
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BDL/39
LONG TERM....TDP
AVIATION...39
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1113 PM MDT THU AUG 16 2012
.UPDATE...
ISSUED AT 840 PM MDT THU AUG 16 2012
MADE MINOR ADJUSTMENTS TO POP/WX FORECAST FOR TONIGHT...KEEPING
CHANCE POPS IN FAR EASTERN CWA. 00Z HAS TRENDED FURTHER
SOUTH AND EAST WITH AXIS OF FRONOTGENETIC FORCING AND POSITIVE
THETA-E ADVECTION. I DIDNT WANT TO IGNORE THE LATEST RUC QPF WHICH
WOULD SUPPORT ACTIVITY FURTHER WEST...HOWEVER CONSIDERING THE BEST
LARGE SCALE SUPPORT DOESNT LOOK BE THERE I KEPT CHANCES LIMITED TO
20 PERCENT ACROSS MOST OF THE CWA. OVERALL TIMING FROM PREVIOUS
FORECAST STILL LOOKS GOOD WITH ANY SHOWERS/ISOLATED THUNDERSTORMS
DEVELOPING AROUND 09Z IN THE SOUTHEAST...SPREADING NORTH AND EAST
THROUGH FRIDAY MORNING BEFORE MOVING OUT OF OUR CWA AROUND 15Z.
UPDATE ISSUED AT 356 PM MDT THU AUG 16 2012
JUST COMPLETED MINOR UPDATE TO CAPTURE LATEST TREND REGARDING
POPS/SKY OVER WESTERN PARTS OF CWA. ACTIVITY OVER FRONT RANGE
CURRENTLY PROGRESSING EASTWARD TOWARDS WESTERN EXTENT OF CWA.
BASED ON LATEST RUC INSTABILITY REMAINS VERY WEAK OVER OUR CWA
AND THERE IS LITTLE IN THE WAY OF LARGE SCALE ASCENT. JUST BASED
ON CURRENT RADAR TRENDS AND RUC QPF I COULDNT RULE OUT AN ISOLATED
SHOWER OR THUNDERSTORM SNEAKING INTO WESTERN YUMA AND KIT CARSON
COUNTIES LATE THIS AFTERNOON OR EARLY THIS EVENING BEFORE DIURNAL
HEATING COMES TO AN END AND LOW LEVEL LAPSE RATES DECREASE. NO
OTHER SIGNIFICANT CHANGE MADE.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 210 PM MDT THU AUG 16 2012
18Z WATER VAPOR IMAGERY INDICATED AN UPPER LEVEL SHORT WAVE TROUGH
OVER THE NORTH CENTRAL CONUS...WITH THE TROUGH AXIS EXTENDING
SOUTHWEST INTO WESTERN KANSAS. AT THE SURFACE HIGH PRESSURE WAS
OVER THE NEBRASKA PANHANDLE...BUILDING SOUTHEAST. THE COLD FRONT WAS
BACKED UP AGAINST THE ROCKIES AND EXTENDED SOUTHEAST INTO THE TEXAS
PANHANDLE.
TONIGHT WINDS WILL BE LIGHT AS THE HIGH PRESSURE BUILDS INTO THE
AREA. DURING THE OVERNIGHT HOURS THE SURFACE HIGH MOVES EAST OF THE
AREA. MEANWHILE WARM AIR ADVECTION IN THE 750-650 MB LAYER AND
MOISTURE INCREASE OVER THE EASTERN PART OF THE AREA BEHIND THE
SURFACE HIGH. A DRY LAYER WILL REMAIN IN PLACE BELOW 750MB SO WILL
KEEP THE PRECIPITATION CHANCES IN THE SLIGHT CATEGORY.
EARLY FRIDAY MORNING WARM AIR ADVECTION INCREASES AND AN UPPER LEVEL
SHORT WAVE TROUGH MOVES OVER THE EASTERN HALF OF THE AREA.
INCREASED PRECIP. CHANCES DURING THE FIRST HALF OF THE MORNING WHEN
THE LIFT AND MOISTURE WILL BE GREATEST. DURING THE LATE MORNING AND
AFTERNOON THE BETTER ISENTROPIC LIFT/MOISTURE MOVE EAST WITH THE
SHORT WAVE TROUGH...BRINGING PRECIPITATION CHANCES TO AN END FROM WEST
TO EAST. DURING THE LATE AFTERNOON SURFACE CONVERGENCE/LIFT FROM A
700MB SHORT WAVE TROUGH DEVELOP OVER LINCOLN COUNTY CO. POINT
SOUNDINGS SHOW THE AIR MASS EITHER BEING TOO DRY OR CAPPED. HOWEVER
AS THE SURFACE HIGH MOVES EAST IT WILL DRAG THE FRONT ACROSS THE
WEST HALF OF AREA WITH IT. WILL INCLUDE LOW SLIGHT CHANCES OVER THE
FAR WEST DURING THE LATE AFTERNOON DUE TO THE SHORT WAVE AND FRONT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 210 PM MDT THU AUG 16 2012
NORTHWEST FLOW WILL CONTINUE THROUGH SUNDAY WITH A RIDGE OVER THE
ROCKIES AND AN UPPER LOW NORTH OF THE GREAT LAKES. SURFACE HIGH
PRESSURE WILL RESIDE OVER THE CENTRAL PLAINS THROUGH THIS TIME.
A SHORTWAVE COMES THROUGH THE FLOW FRIDAY NIGHT/EARLY SATURDAY. THE
BEST FORCING COMES ACROSS THE FA FRIDAY NIGHT WITH DYNAMICS EXITING
ALL BUT THE EASTERN FA SATURDAY MORNING. SUBSIDENCE MOVES INTO THE
FA SATURDAY AFTERNOON/NIGHT. SUBSIDENCE CONTINUES SUNDAY. 850-700
LAYER MEAN RH IS LIMITED WITH THE BEST MOISTURE JUST TO THE EAST OF
THE FA. DUE TO THE LIMITED MOISTURE WILL GO WITH SLIGHT CHANCE POPS
FRIDAY NIGHT/EARLY SATURDAY WITH NIL POPS SATURDAY AFTERNOON/NIGHT
THROUGH SUNDAY.
MIN TEMPERATURES WILL BE IN THE MID 50S FRIDAY NIGHT AND THE LOWER
TO MID 50S SATURDAY NIGHT. MAX TEMPERATURES WILL RISE TO THE LOWER
80S SATURDAY/SUNDAY.
FOR SUNDAY NIGHT THROUGH THURSDAY...A RIDGE WILL BE OVER THE ROCKIES
THROUGH THURSDAY. OTHER THAN SURFACE HIGH PRESSURE SUNDAY, A TROUGH
WILL EXIST OVER EASTERN COLORADO THROUGH THURSDAY.
SHORTWAVES IN THE FLOW WILL BRING A SLIGHT CHANCE OF THUNDERSTORMS
MONDAY THROUGH TUESDAY NIGHT. DYNAMICS MOVE OFF TO THE NORTHEAST
WEDNESDAY WITH SUBSIDENCE FOLLOWING WEDNESDAY NIGHT/THURSDAY.
850 TEMPERATURES INDICATE STEADILY WARMER TEMPERATURES WITH MAX
TEMPERATURES IN THE MID 80S MONDAY WARMING TO THE LOWER 90S
WEDNESDAY COOLING SLIGHTLY TO THE UPPER 80S THURSDAY. MIN
TEMPERATURES WILL RANGE FROM THE LOWER 60S TO THE MID 60S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1112 PM MDT THU AUG 16 2012
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD AT BOTH KGLD AND
KMCK TERMINALS. LIGHT EASTERLY WINDS ARE EXPECTED OVERNIGHT. WINDS
WILL SHIFT TO THE SOUTHEAST AND INCREASE AFTER SUNRISE AS HIGH
PRESSURE SHIFTS EAST...WITH GUSTS AT KGLD AROUND 22KT. WINDS WILL
REMAINING AROUND 9KT AT KMCK THROUGH THE REMAINING TAF PERIOD.
CONFIDENCE IN PRECIP TONIGHT AT EITHER TERMINAL HAS GREATLY
DIMINISHED WITH SHORT RANGE GUIDANCE TRENDING MUCH DRIER...WITH
FOCUS STILL SOUTHEAST OF EITHER TERMINAL. THUNDERSTORMS MAY
DEVELOP IN THE WEST FRIDAY AFTERNOON AND MOVE EAST TOWARDS KGLD
AND KMCK FRIDAY EVENING...HOWEVER COVERAGE IS STILL A BIG QUESTION
SO I LEFT MENTION OUT OF TAFS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...DR
SHORT TERM...FS
LONG TERM...JTL
AVIATION...DR
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1140 PM MDT THU AUG 16 2012
.AVIATION...
06Z TAF CYCLE
WHILE VFR CONDITIONS WILL PREVAIL IN MOST LOCALES OF NORTHERN AND
CENTRAL NEW MEXICO...BATCHES OF REMNANT THUNDERSTORMS WILL PRODUCE
BRIEF AND LOCALIZED DOWNPOURS REDUCING VISIBILITIES AND CEILINGS
TEMPORARILY TO MVFR CONDITIONS. COVERAGE HAS DWINDLED
SIGNIFICANTLY...BUT STORMS WILL CONTINUE TO IMPACT CENTRAL
HIGHLANDS AND A NEW BATCH OF STORMS COULD ROLL OFF OF THE NORTHERN
MOUNTAINS AND INTO THE CENTRAL HIGHLANDS AND EAST CENTRAL PLAINS
BEFORE DAWN FRIDAY. GUSTY AND ERRATIC WINDS AND SMALL HAIL WILL
ALSO ACCOMPANY THE DOWNPOURS. ANOTHER ACTIVE AFTERNOON/EVENING IS
ANTICIPATED ON FRIDAY WITH STORMS FAVORING THE CENTRAL MOUNTAIN
CHAIN AND ADJACENT HIGH PLAINS...AS WELL AS PARTS OF THE
SOUTHWESTERN MOUNTAINS.
52
&&
.PREV DISCUSSION...913 PM MDT THU AUG 16 2012...
QUICK ZFP UPDATE JUST SENT. ADJUSTED WINDS IN THE MIDDLE/LOWER RIO
GRANDE VALLEY DUE TO GUSTS TO AROUND 35 MPH CONTINUING AT THE
SUNPORT THIS EVENING. ALSO TRIMMED OVERNIGHT POPS BACK AS
CONVECTION STARTING TO WANE.
.PREV DISCUSSION...323 PM MDT THU AUG 16 2012...
DEFINITE INCREASE IN STORM STRENGTH AND COVERAGE TODAY AS EXPECTED
WITH SEVERAL FORCING MECHANISMS IN PLACE OVER THE STATE. CIRA BLENDED
PWAT IMAGERY SHOWING VALUES OF 100-125 PCT OF NORMAL. THE AXIS OF THE
H5 RIDGE IS POSITIONED FROM NORTHERN AZ SOUTHEAST ACROSS WEST CENTRAL
NM. H5 TEMPS OF -6 TO -7C ARE HELPING NOT TO CAP ANY CONVECTION AS
HAS BEEN THE CASE. WINDS ARE ALSO VERY WEAK ABOVE 700MB SO COMBINATION
OF HIGHER MOISTURE...COOLER TEMPS ALOFT...AND GOOD SURFACE HEATING WILL
ALLOW FOR LOCALLY HEAVY RAINFALL THRU THIS EVENING. THE HRRR AND RUC
MODELS INDICATE CONVECTION WILL ORGANIZE INTO THE MIDDLE RIO GRANDE
VALLEY SOUTHEASTWARD SO HAVE RAISED POPS TO HIGH CHANCE AND LIKELY.
DID NOT HAVE HIGH ENOUGH CONFIDENCE TO PLACE LOCALLY HEAVY RAINFALL
WORDING IN FORECAST FOR TONIGHT...AND FOR THAT MATTER THE NEXT FEW
DAYS...AS IT WILL BE HARD TO PINPOINT ANY SPECIFIC AREA FOR ENHANCED
THREAT.
THE H5 RIDGE AXIS WILL CHANGE LITTLE OVER THE NEXT FEW DAYS...SETTING
UP WEAK STEERING FLOW FOR CENTRAL AND WESTERN NM WHILE THE EAST ENJOYS
THE BENEFITS OF NW FLOW ALOFT. LIGHT UPSLOPE FLOW ACROSS THE PLAINS
ONTO THE EAST SLOPES BENEATH NW FLOW WILL BE FAVORABLE FOR POTENTIALLY
SOME OF BEST PRECIP SEEN IN QUITE SOME TIME. ANOTHER BACK DOOR FRONT
SUNDAY WILL JUST ENHANCE MOISTURE AND PRECIP CHANCES AGAIN. RAISED
POPS EVEN MORE TO THE HIGH CHANCE/LIKELY CATEGORY THRU THE WEEKEND.
TEMPS WILL BE MUCH CLOSER TO NORMAL AND EVEN A FEW DEGREES BELOW. GAP
WINDS ARE EXPECTED AGAIN IN THE RIO GRANDE VALLEY SATURDAY EVENING
INTO SUNDAY MORNING.
MODELS REMAIN AT ODDS BEYOND THE WEEKEND WITH HOW MUCH CONDITIONS WILL
DRY OUT. THE GFS HAS THE RIDGE SLIDING EAST AND CENTERING OVER CENTRAL
NM MONDAY THRU MOST OF NEXT WEEK...WHILE THE ECMWF KEEPS THE RIDGE TO
THE WEST AND FORCING MORE BACK DOOR FRONTS INTO THE AREA. GIVEN THE
PATTERN THIS SUMMER WILL BE FAVORING THE ECMWF AT THIS TIME...WHICH
WILL KEEP TEMPS NEAR NORMAL AND PRECIP CHANCES PERHAPS AT CLIMO FOR
LATE AUGUST. GUYER
.FIRE WEATHER...
CRITICAL FIRE WEATHER...NOT EXPECTED THROUGH AT LEAST MIDWEEK NEXT
WEEK.
FCST MODELS REMAIN IN FAIRLY GOOD AGREEMENT ON GENERAL FCST PATTERN
THROUGH THE START TO MIDDLE OF NEXT WEEK. UPPER HIGH CENTER TO
CONTINUE TO MEANDER BACK AND FORTH GENERALLY BETWEEN NV AND AZ. THIS
WILL ALLOW FOR SOME WEAK TO MODERATE LOW LVL MOISTURE REPLENISHMENT
FROM THE E THROUGH S FROM TIME TO TIME WITH COMBINATION OF WESTBOUND
THROUGH NORTHBOUND OUTFLOWS FROM STORM COMPLEXES IN S AND E HALVES
OF THE STATE AS WELL AS CURRENT WEAKENING BACK DOOR FRONT VCNTY OF
RIO GRANDE VALLEY AS OF THIS WRITING AND ANOTHER ONE DUE INTO E AND
PERHAPS CENTRAL NM OVER THE WEEKEND.
SHOWERS AND STORMS THIS EVE AND OVERNIGHT TO BE MOST NUMEROUS...AND
WITH GOOD WETTING FOOTPRINTS...TO E OF THE CONTINENTAL DIVIDE WITH
MOST LIGHTNING OVER WITH BY OR NOT TOO LONGER AFTER MIDNIGHT...
ESPECIALLY HIGHER TERRAIN. GOOD TO EXCELLENT HUMIDITY RECOVERIES
OVERNIGHT.
FOR FRIDAY...ACTIVE CONVECTION EXPECTED ACROSS THE STATE...WITH
WETTING RAINS THE BEST BET AGAIN E OF DIVIDE. MINIMUM HUMIDITIES
INCREASING TO THE HIGH 20S TO THE MID 40S PCT RANGE OVER MUCH OF THE
STATE...WITH SOME HIGH TEENS AND 20S PCT REMAINING OVER THE DRYER
NORTHWEST QUADRANT. AGAIN GOOD TO EXCELLENT HUMIDITY RECOVERY
OVERNIGHT.
SATURDAY WILL BRING WEAK COLD FRONT INTO THE NORTHEAST PLAINS...
PROGRESSING TO THE S AND W LATER IN THE DAY THROUGH SUN AM. WETTING
RAINS MOST LIKELY ALONG AND E THROUGH N OF FRONTAL BOUNDARY. NW
PLATEAU STILL GETTING THE SHORT END OF THE STICK WITH REGARDS TO
CONVECTION AND WETTING RAIN. VERY GOOD TO EXCELLENT RECOVERIES
OVERNIGHT FOR ALL BUT THE NORTHWEST...WHERE RECOVERY WILL DROP BACK
INTO THE GOOD CATEGORY. FOR SUN THROUGH TUE THE UPPER HIGH AND RIDGE
STILL GENERALLY TO W OF NM. PRETTY GOOD CHANCES FOR WETTING RAINS
SUNDAY BUT BEGINNING A BIT OF A DOWNTURN MON AND TUE. AFTN TEMPS
SHOULD WARM A FEW DEGREES MOST AREAS BY MON OR TUE AND THIS WILL
LOWER MIN HUMIDITIES AND LESSEN OVERNIGHT RECOVERIES. 43
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BUFFALO NY
514 AM EDT FRI AUG 17 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE REGION THROUGH THIS MORNING
PRODUCING A BAND OF SHOWERS AND POSSIBLY A THUNDERSTORM. FOLLOWING
THE PASSAGE OF THE COLD FRONT EXPECT COOLER TEMPERATURES AND LESS
HUMID CONDITIONS FOR THIS AFTERNOON AND THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE MAIN FORECAST CHALLENGE FOR TODAY IS HOW WIDESPREAD RAINFALL
WILL BE WITH THE FRONTAL PASSAGE THIS MORNING. THROUGH 500
AM...RADAR SHOWS A FAIRLY SOLID LINE OF SHOWERS WITH EMBEDDED
THUNDERSTORMS ACROSS AND JUST EAST OF LAKE ERIE. MODEL GUIDANCE
IS CONSISTENT IN EXPANDING THIS AREA OF SHOWERS AS IT MOVES ACROSS
WESTERN NEW YORK...AND A ROUND OF SHOWERS APPEARS LIKELY FOR THE REGION.
THE 00Z GFS/AND 04Z HRRR HAD A FAIRLY GOOD HANDLE ON THE UPSTREAM
MCS...AND HAVE HAD A GOOD HANDLE ON SHOWER DEVELOPMENT ON LAKE
ERIE SO FAR. THESE STILL SUGGEST THAT SHOWERS WILL LIKELY
ACCOMPANY THE FRONT EARLY THIS...WITH STEADIEST RAIN SHOWERS
BUFFALO SOUTHWARD AS WINDS SHIFTING TO THE NORTHWEST SWEEP
MOISTURE FROM LAKE ERIE INTO WESTERN PORTIONS OF THE SOUTHERN
TIER. THE FRONTAL WILL BRING A COUPLE HOURS OF SHOWERS TO
MOST...WITH QPFS MAINLY ON THE LIGHT SIDE...LESS THAN A TENTH OF
AN INCH. LOOK FOR A BIT MORE THAN THIS BUFFALO SOUTHWARD...WHERE A
BLEND OF THE GFS/HRRR FORECAST AROUND A QUARTER INCH OF RAIN.
THE FRONT WILL EXIT TO THE EAST BY THIS AFTERNOON...WHICH WILL END
THE STEADY RAIN SHOWERS. HOWEVER...WITH COOLER AIR MOVING IN BEHIND
THE FRONT...AND THE RELATIVELY WARM LAKES...EXPECT ANY BRIEF
CLEARING WILL LIKELY FILL IN WITH LAKE-AIDED STRATOCUMULUS THIS
AFTERNOON. NOTED THE HRRR KEYS SOME SHOWERS EARLY AFTERNOON AS THE
LAKE ERIE BREEZE CONVERGENCES WITH THE OTHERWISE WNW FLOW. THIS IS
PLAUSIBLE...BUT GIVEN THE ISOLATED NATURE OF THIS CONVERGENCE AREA
AND THE CAP SHOWN AT 10K FEET BY THE NAM...WILL ONLY CARRY SLIGHT
CHANCE POPS.
OTHERWISE...HIGH PRESSURE WILL BUILD ACROSS THE REGION FROM THE WEST
TONIGHT. THIS SHOULD RESULT IN A GENERAL DRYING TREND...WHERE
LINGERING CLOUDS FROM THE DAY SHOULD DISSIPATE. THIS SAID...A MORE
WESTERLY FLOW ON LAKE ONTARIO MAY ALLOW FOR LAKE CONVERGENCE CLOUDS
TO DEVELOP AND MOVE EAST OF LAKE ONTARIO LATE TONIGHT. THERE SHOULD
BE AMPLE PERIODS OF CLEARING TO ALLOW FOR TEMPERATURES TO COOL
CONSIDERABLY TONIGHT. LOWS WILL LIKELY RANGE FROM THE MID AND UPPER
40S IN THE COOL VALLEYS OF THE SOUTHERN TIER AND EAST OF LAKE ONTARIO...TO
THE LOWER 50S ELSEWHERE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
DURING THE WEEKEND...OUR REGION WILL REMAIN UNDER THE INFLUENCE OF
DEEP UPPER TROUGHING CENTERED NEAR JAMES BAY...WHILE SURFACE BASED
RIDGING OVER THE OHIO VALLEY AND LOWER LAKES GRADUALLY EXPANDS
NORTHEASTWARD INTO NEW ENGLAND.
UNDER THIS PATTERN...COOLER AND MAINLY DRY WEATHER WILL BE
PREDOMINANT. WHILE TEMPS ALOFT WILL BE CERTAINLY COOL ENOUGH FOR A
LAKE RESPONSE...THE RELATIVELY DRY NATURE OF OUR AIRMASS AND A FAIR
AMOUNT OF LOW LEVEL SHEAR SHOULD PREVENT MUCH MORE THAN SOME
LAKE-DRIVEN STRATOCU DOWNWIND OF THE LAKES EARLY SATURDAY
MORNING...AND AGAIN LATER SATURDAY NIGHT INTO EARLY SUNDAY.
SYNOPTICALLY...THE NAM/GFS/ECMWF ALL TRY TO SPIT OUT SOME SPOTTY
LIGHT SHOWERS ACROSS PARTS OF THE AREA SUNDAY AFTERNOON WITH DAYTIME
HEATING AND THE APPROACH OF A MODEST SHORTWAVE...BUT THIS STILL
APPEARS TO BE WORTHY OF NO MORE THAN SOME SLIGHT CHANCE POPS GIVEN
ONLY VERY LIMITED AMOUNTS OF AVAILABLE MOISTURE.
IN TERMS OF ACTUAL TEMPERATURES...850 MB READINGS WILL AVERAGE IN
THE +7C TO +9C RANGE SATURDAY...AND A DEGREE OR SO WARMER THAN THAT
ON SUNDAY. THIS WILL TRANSLATE INTO COMFORTABLE HIGHS IN THE LOWER
70S ON SATURDAY...AND THE LOWER TO MID 70S ON SUNDAY. MEANWHILE...
NIGHTTIME LOWS SATURDAY NIGHT WILL RANGE FROM THE MID 40S ACROSS
INTERIOR SECTIONS OF THE SOUTHERN TIER AND NORTH COUNTRY TO THE
LOWER 50S ALONG THE LAKE PLAINS...BEFORE MODERATING A FEW DEGREES
FOR SUNDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
THE COOL WEATHER OF THE SHORT TERM PERIOD WILL PERSIST INTO THE
FIRST COUPLE DAYS OF THE EXTENDED RANGE AS WELL...AS THE LARGE-SCALE
UPPER TROUGH REMAINS IN PLACE ACROSS THE GREAT LAKES AND NORTHEAST.
WITH DAYTIME HEATING OF THE STILL-COOL AIRMASS ALOFT...THE PASSAGE
OF A VERY WEAK SURFACE TROUGH COULD SET OFF SOME ISOLATED SHOWER AND
THUNDERSTORM ACTIVITY ON MONDAY...WITH THE APPROACH AND PASSAGE OF
THE MAIN UPPER TROUGH AXIS POSSIBLY DOING THE SAME ON TUESDAY. WILL
ACCORDINGLY KEEP SLIGHT CHANCE POPS IN PLACE FOR BOTH DAYS...WITH
ANY PRECIP THAT DOES FORM DIMINISHING WITH THE LOSS OF HEATING BOTH
MONDAY AND TUESDAY EVENINGS. 850 MB TEMPS LINGERING IN THE +8C TO
+10C RANGE WILL SUPPORT HIGHS IN THE LOWER TO MID 70S BOTH
DAYS...WITH NIGHTTIME LOWS IN THE 50S EXPECTED BOTH NIGHTS.
AFTER THAT...THE GFS AND ECMWF REMAIN IN GOOD AGREEMENT ON THE CORE
OF THE UPPER TROUGH LIFTING OFF INTO LABRADOR AND THEN INTO THE
NORTHERN ATLANTIC...WITH A RELATIVELY FLAT ZONAL FLOW SETTING UP
ACROSS THE LOWER LAKES AND NORTHEAST IN ITS WAKE. THE ENSUING WARM
AIR ADVECTION PATTERN WILL RESULT IN A GRADUAL WARMING TREND THROUGH
THE PERIOD...WITH DAYTIME HIGHS RECOVERING TO NEAR THE 80 DEGREE
MARK BY THURSDAY...AND NIGHTTIME LOWS ALSO MODERATING A FEW DEGREES
EACH NIGHT. AS FOR PRECIP CHANCES...THESE LOOK TO BE PRACTICALLY NIL
ON WEDNESDAY WITH THE DEPARTURE OF THE TROUGH AND LOW-LEVEL RIDGING
REMAINING IN PLACE...BEFORE CLIMBING BACK INTO THE SLIGHT CHANCE
RANGE ON THURSDAY WITH THE APPROACH OF ANOTHER WEAK SURFACE TROUGH.
&&
.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
THROUGH 09Z...RADAR SHOWS A FAIRLY SOLID LINE OF SHOWERS WITH
EMBEDDED THUNDERSTORMS ACROSS AND JUST EAST OF LAKE ERIE. THIS
WILL BRING A PERIOD OF RAIN TO TAF SITES...AND PERHAPS A
THUNDERSTORM. CONDITIONS SHOULD MAINLY BE VFR OUTSIDE OF HEAVIER
RAIN SHOWERS WHICH MAY BRIEFLY LOWER VSBY TO AROUND 2SM.
FOLLOWING THE PASSAGE OF THE COLD FRONT EXPECT THE VFR LEVEL DECK TO
TEMPORARILY SCATTER OUT FRIDAY MORNING...ONLY TO FILL BACK IN AGAIN
WITH DAYTIME HEATING AS MOISTURE BECOMES TRAPPED BENEATH THE
SUBSIDENCE INVERSION. EXPECT MOST IF NOT ALL OF THIS POST-FRONTAL
CLOUD COVER TO BE VFR IN THE 035-050 KFT RANGE. THIS DECK SHOULD
SLOWLY SCATTER OUT TONIGHT AS WINDS OFF THE LAKES DIMINISH...AND
DRIER AIR MOVES IN.
OUTLOOK...
SATURDAY...POSSIBLE MVFR/IFR IN FOG EARLY OTHERWISE VFR.
SUNDAY...VFR.
MONDAY...CHANCE OF SHOWERS/TSTMS. MAINLY VFR.
TUESDAY...VFR.
&&
.MARINE...
A COLD FRONT WILL MOVE ACROSS THE WATERS FROM WEST TO EAST THIS
MORNING. WINDS WILL BRIEFLY BE BREEZY AHEAD OF THE FRONT...BUT THE
SSW WIND DIRECTION IS UNFAVORABLE FOR BUILDING WAVES ON LAKE
ONTARIO. DO HAVE SOME CONCERN ON LAKE ERIE...WHERE A QUICK SHIFT TO
THE NW BEHIND THE THE FRONT EARLY THIS MORNING WILL LIKELY RESULT IN
A FEW HOURS OF CHOPPY CONDITIONS. BECAUSE OF THIS WILL ISSUE A BRIEF
SMALL CRAFT ADVISORY FOR LAKE ERIE THROUGH LATE MORNING.
WITH SHOWERS AND THUNDERSTORMS MOVING ACROSS THE LAKES THROUGH THIS
MORNING...AN ISOLATED WATERSPOUT CANNOT BE RULED OUT. THIS
SAID...TEMPERATURES ALOFT ARE NOT AS COLD AS A FEW DAYS AGO...SO ANY
ACTIVITY SHOULD NOT BE AS NEARLY WIDESPREAD.
THIS AFTERNOON...WINDS WILL SHIFT TO THE WNW BEHIND THE FRONT. THIS
FLOW WILL PERSIST...AND WILL LIKELY PRODUCE WAVES TO 5 FT ON EASTERN
PORTIONS OF LAKE ONTARIO MID-AFTERNOON ONWARD. WINDS WILL GRADUALLY
DIMINISH LATE TONIGHT.
FINE BOATING CONDITIONS ARE THEN EXPECTED FOR THE WEEKEND.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR LEZ040-
041.
SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 2 AM
EDT SATURDAY FOR LOZ044-045.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...APFFEL
MARINE...APFFEL
AREA FORECAST DISCUSSION
NWS BUFFALO NY
346 AM EDT FRI AUG 17 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE REGION THROUGH THIS MORNING
PRODUCING A BAND OF SHOWERS AND POSSIBLY A THUNDERSTORM. FOLLOWING
THE PASSAGE OF THE COLD FRONT EXPECT COOLER TEMPERATURES AND LESS
HUMID CONDITIONS FOR THIS AFTERNOON AND THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE MAIN FORECAST CHALLENGE FOR TODAY IS HOW WIDESPREAD RAINFALL
WILL BE WITH THE FRONTAL PASSAGE THIS MORNING. THROUGH 330
AM...RADAR SHOWS SHOWERS FILLING IN AHEAD OF THE FRONTAL
BOUNDARY...BUT STILL WEAK AND SOMEWHAT SCATTERED IN NATURE. MODEL
GUIDANCE IS CONSISTENT IN EXPANDING THIS AREA OF SHOWERS AS IT MOVES
ACROSS WESTERN NEW YORK...BUT MUCH OF THIS GUIDANCE HAS ALSO BEEN
OVERDONE IN THE DEVELOPMENT OF SHOWERS ACROSS LAKE ERIE THROUGH 06Z.
A SIGNIFICANT MCS TRACKED ACROSS KENTUCKY YESTERDAY EVENING...AND
THIS MAY HAVE TAKEN SOME OF THE MOISTURE WHICH WAS FORECAST TO
ENHANCE SHOWERS IN WESTERN NEW YORK. THIS SAID...A ROUND OF SHOWERS
STILL APPEAR LIKELY FOR WESTERN NEW YORK. A THUNDERSTORM IS STILL
POSSIBLE...THOUGH CONFIDENCE IN THIS IS LOW WITH NO STORMS UPSTREAM
YET.
THE 00Z GFS/AND 04Z HRRR HAD A FAIRLY GOOD HANDLE ON THE UPSTREAM
MCS...AND HAVE DONE BEST IN FORECASTING THE LIMITED SHOWER ON LAKE ERIE
DEVELOPMENT SO FAR. THESE STILL SUGGEST THAT SHOWERS WILL LIKELY
ACCOMPANY THE FRONT EARLY THIS...WITH STEADIEST RAIN SHOWERS BUFFALO
SOUTHWARD AS WINDS SHIFTING TO THE NORTHWEST SWEEP MOISTURE FROM
LAKE ERIE INTO WESTERN PORTIONS OF THE SOUTHERN TIER. THE FRONTAL
WILL BRING A COUPLE HOURS OF SHOWERS TO MOST...WITH QPFS MAINLY ON
THE LIGHT SIDE...LESS THAN A TENTH OF AN INCH. LOOK FOR A BIT MORE
THAN THIS BUFFALO SOUTHWARD...WHERE A BLEND OF THE GFS/HRRR FORECAST
AROUND A QUARTER INCH OF RAIN.
THE FRONT WILL EXIT TO THE EAST BY THIS AFTERNOON...WHICH WILL END
THE STEADY RAIN SHOWERS. HOWEVER...WITH COOLER AIR MOVING IN BEHIND
THE FRONT...AND THE RELATIVELY WARM LAKES...EXPECT ANY BRIEF
CLEARING WILL LIKELY FILL IN WITH LAKE-AIDED STRATOCUMULUS THIS
AFTERNOON. NOTED THE HRRR KEYS SOME SHOWERS EARLY AFTERNOON AS THE
LAKE ERIE BREEZE CONVERGENCES WITH THE OTHERWISE WNW FLOW. THIS IS
PLAUSIBLE...BUT GIVEN THE ISOLATED NATURE OF THIS CONVERGENCE AREA
AND THE CAP SHOWN AT 10K FEET BY THE NAM...WILL ONLY CARRY SLIGHT
CHANCE POPS.
OTHERWISE...HIGH PRESSURE WILL BUILD ACROSS THE REGION FROM THE WEST
TONIGHT. THIS SHOULD RESULT IN A GENERAL DRYING TREND...WHERE
LINGERING CLOUDS FROM THE DAY SHOULD DISSIPATE. THIS SAID...A MORE
WESTERLY FLOW ON LAKE ONTARIO MAY ALLOW FOR LAKE CONVERGENCE CLOUDS
TO DEVELOP AND MOVE EAST OF LAKE ONTARIO LATE TONIGHT. THERE SHOULD
BE AMPLE PERIODS OF CLEARING TO ALLOW FOR TEMPERATURES TO COOL
CONSIDERABLY TONIGHT. LOWS WILL LIKELY RANGE FROM THE MID AND UPPER
40S IN THE COOL VALLEYS OF THE SOUTHERN TIER AND EAST OF LAKE ONTARIO...TO
THE LOWER 50S ELSEWHERE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
DURING THE WEEKEND...OUR REGION WILL REMAIN UNDER THE INFLUENCE OF
DEEP UPPER TROUGHING CENTERED NEAR JAMES BAY...WHILE SURFACE BASED
RIDGING OVER THE OHIO VALLEY AND LOWER LAKES GRADUALLY EXPANDS
NORTHEASTWARD INTO NEW ENGLAND.
UNDER THIS PATTERN...COOLER AND MAINLY DRY WEATHER WILL BE
PREDOMINANT. WHILE TEMPS ALOFT WILL BE CERTAINLY COOL ENOUGH FOR A
LAKE RESPONSE...THE RELATIVELY DRY NATURE OF OUR AIRMASS AND A FAIR
AMOUNT OF LOW LEVEL SHEAR SHOULD PREVENT MUCH MORE THAN SOME
LAKE-DRIVEN STRATOCU DOWNWIND OF THE LAKES EARLY SATURDAY
MORNING...AND AGAIN LATER SATURDAY NIGHT INTO EARLY SUNDAY.
SYNOPTICALLY...THE NAM/GFS/ECMWF ALL TRY TO SPIT OUT SOME SPOTTY
LIGHT SHOWERS ACROSS PARTS OF THE AREA SUNDAY AFTERNOON WITH DAYTIME
HEATING AND THE APPROACH OF A MODEST SHORTWAVE...BUT THIS STILL
APPEARS TO BE WORTHY OF NO MORE THAN SOME SLIGHT CHANCE POPS GIVEN
ONLY VERY LIMITED AMOUNTS OF AVAILABLE MOISTURE.
IN TERMS OF ACTUAL TEMPERATURES...850 MB READINGS WILL AVERAGE IN
THE +7C TO +9C RANGE SATURDAY...AND A DEGREE OR SO WARMER THAN THAT
ON SUNDAY. THIS WILL TRANSLATE INTO COMFORTABLE HIGHS IN THE LOWER
70S ON SATURDAY...AND THE LOWER TO MID 70S ON SUNDAY. MEANWHILE...
NIGHTTIME LOWS SATURDAY NIGHT WILL RANGE FROM THE MID 40S ACROSS
INTERIOR SECTIONS OF THE SOUTHERN TIER AND NORTH COUNTRY TO THE
LOWER 50S ALONG THE LAKE PLAINS...BEFORE MODERATING A FEW DEGREES
FOR SUNDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
THE COOL WEATHER OF THE SHORT TERM PERIOD WILL PERSIST INTO THE
FIRST COUPLE DAYS OF THE EXTENDED RANGE AS WELL...AS THE LARGE-SCALE
UPPER TROUGH REMAINS IN PLACE ACROSS THE GREAT LAKES AND NORTHEAST.
WITH DAYTIME HEATING OF THE STILL-COOL AIRMASS ALOFT...THE PASSAGE
OF A VERY WEAK SURFACE TROUGH COULD SET OFF SOME ISOLATED SHOWER AND
THUNDERSTORM ACTIVITY ON MONDAY...WITH THE APPROACH AND PASSAGE OF
THE MAIN UPPER TROUGH AXIS POSSIBLY DOING THE SAME ON TUESDAY. WILL
ACCORDINGLY KEEP SLIGHT CHANCE POPS IN PLACE FOR BOTH DAYS...WITH
ANY PRECIP THAT DOES FORM DIMINISHING WITH THE LOSS OF HEATING BOTH
MONDAY AND TUESDAY EVENINGS. 850 MB TEMPS LINGERING IN THE +8C TO
+10C RANGE WILL SUPPORT HIGHS IN THE LOWER TO MID 70S BOTH
DAYS...WITH NIGHTTIME LOWS IN THE 50S EXPECTED BOTH NIGHTS.
AFTER THAT...THE GFS AND ECMWF REMAIN IN GOOD AGREEMENT ON THE CORE
OF THE UPPER TROUGH LIFTING OFF INTO LABRADOR AND THEN INTO THE
NORTHERN ATLANTIC...WITH A RELATIVELY FLAT ZONAL FLOW SETTING UP
ACROSS THE LOWER LAKES AND NORTHEAST IN ITS WAKE. THE ENSUING WARM
AIR ADVECTION PATTERN WILL RESULT IN A GRADUAL WARMING TREND THROUGH
THE PERIOD...WITH DAYTIME HIGHS RECOVERING TO NEAR THE 80 DEGREE
MARK BY THURSDAY...AND NIGHTTIME LOWS ALSO MODERATING A FEW DEGREES
EACH NIGHT. AS FOR PRECIP CHANCES...THESE LOOK TO BE PRACTICALLY NIL
ON WEDNESDAY WITH THE DEPARTURE OF THE TROUGH AND LOW-LEVEL RIDGING
REMAINING IN PLACE...BEFORE CLIMBING BACK INTO THE SLIGHT CHANCE
RANGE ON THURSDAY WITH THE APPROACH OF ANOTHER WEAK SURFACE TROUGH.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
THROUGH 06Z...RADAR SHOWS BROKEN AND GENERALLY LIGHT SHOWERS
UPSTREAM WITH THE FRONT. EXPECT LAKE ERIE TO PROVIDE SOME MOISTURE
ENHANCEMENT...BUT EVEN WITH THIS THERE SHOULD ONLY BE A BRIEF
PERIOD OF RAIN SHOWERS NEAR THE FRONTAL PASSAGE. AHEAD OF THE
FRONT...EXPECT CIGS/VSBY TO REMAIN IN THE VFR CATEGORY...EVEN AS
SHOWERS MOVE IN. WITH THE FRONT...SURFACE WINDS WILL SHIFT TO THE
NW...AND THIS MAY BRING A BRIEF PERIOD WHERE CIGS LOWER WHILE RAIN
SHOWERS LINGER. TSTMS CANNOT COMPLETELY BE RULED OUT...BUT ANY
SHOULD BE ISOLATED IN NATURE.
BASED ON VAD WIND PROFILE AND RAP FORECASTS....THERE WILL BE A
BRIEF PERIOD OF 30 TO 40 KT WINDS DOWN TO AROUND 1500 FEET THROUGH
DAYBREAK. WHILE MARGINAL...WILL CARRY A FEW HOURS OF LLWS SINCE
THIS IS NOT EXPECTED TO MIX DOWN TO THE SURFACE READILY.
FOLLOWING THE PASSAGE OF THE COLD FRONT EXPECT THE VFR LEVEL DECK TO
TEMPORARILY SCATTER OUT FRIDAY MORNING...ONLY TO FILL BACK IN AGAIN
WITH DAYTIME HEATING AS MOISTURE BECOMES TRAPPED BENEATH THE
SUBSIDENCE INVERSION. EXPECT MOST IF NOT ALL OF THIS POST-FRONTAL
CLOUD COVER TO BE VFR IN THE 035-050 KFT RANGE. THIS DECK SHOULD
SLOWLY SCATTER OUT TONIGHT AS WINDS OFF THE LAKES DIMINISH...AND
DRIER AIR MOVES IN.
OUTLOOK...
SATURDAY...POSSIBLE MVFR/IFR IN FOG EARLY OTHERWISE VFR.
SUNDAY...VFR.
MONDAY...CHANCE OF SHOWERS/TSTMS. MAINLY VFR.
TUESDAY...VFR.
&&
.MARINE...
A COLD FRONT WILL MOVE ACROSS THE WATERS FROM WEST TO EAST THIS
MORNING. WINDS WILL BRIEFLY BE BREEZY AHEAD OF THE FRONT...BUT THE
SSW WIND DIRECTION IS UNFAVORABLE FOR BUILDING WAVES ON LAKE
ONTARIO. DO HAVE SOME CONCERN ON LAKE ERIE...WHERE A QUICK SHIFT TO
THE NW BEHIND THE THE FRONT EARLY THIS MORNING WILL LIKELY RESULT IN
A FEW HOURS OF CHOPPY CONDITIONS. BECAUSE OF THIS WILL ISSUE A BRIEF
SMALL CRAFT ADVISORY FOR LAKE ERIE THROUGH LATE MORNING.
WITH SHOWERS AND THUNDERSTORMS MOVING ACROSS THE LAKES THROUGH THIS
MORNING...AN ISOLATED WATERSPOUT CANNOT BE RULED OUT. THIS
SAID...TEMPERATURES ALOFT ARE NOT AS COLD AS A FEW DAYS AGO...SO ANY
ACTIVITY SHOULD NOT BE AS NEARLY WIDESPREAD.
THIS AFTERNOON...WINDS WILL SHIFT TO THE WNW BEHIND THE FRONT. THIS
FLOW WILL PERSIST...AND WILL LIKELY PRODUCE WAVES TO 5 FT ON EASTERN
PORTIONS OF LAKE ONTARIO MID-AFTERNOON ONWARD. WINDS WILL GRADUALLY
DIMINISH LATE TONIGHT.
FINE BOATING CONDITIONS ARE THEN EXPECTED FOR THE WEEKEND.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR LEZ040-
041.
SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 2 AM
EDT SATURDAY FOR LOZ044-045.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...APFFEL
MARINE...APFFEL
AREA FORECAST DISCUSSION
NWS BUFFALO NY
133 AM EDT FRI AUG 17 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE AREA LATE TONIGHT PRODUCING A
BAND OF SHOWERS AND THUNDERSTORMS. FOLLOWING THE PASSAGE OF THE COLD
FRONT EXPECT COOLER TEMPERATURES AND LESS HUMID CONDITIONS FOR
FRIDAY AFTERNOON THROUGH THIS UPCOMING WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
THICKER MID/HIGH CLOUDS JUST UPSTREAM WILL OVERSPREAD THE REGION
OVERNIGHT FROM WEST TO EAST. A BROKEN LINE OF SHOWERS UPSTREAM
ACROSS EASTERN LOWER MICHIGAN AND LAKE HURON CONTINUE TO REALLY
STRUGGLE TO GAIN INTENSITY AND COVERAGE. A MASSIVE MCS WHICH FORMED
EARLIER UPSTREAM ACROSS THE OHIO VALLEY IS LIKELY ROBBING MUCH OF
THE DEEPER MOISTURE WHICH WAS DESTINED FOR FARTHER NORTH ALONG THE
FRONT...AND THIS MAY CONTINUE TO HURT THE CONVECTIVE POTENTIAL ALONG
THE PORTION OF THE COLD FRONT WHICH WILL REACH WESTERN NY LATE
TONIGHT. FOR NOW HAVE HELD ONTO HIGH LIKELY POPS AND IT WILL
PROBABLY RAIN IN MOST AREAS...BUT AMOUNTS ARE LOOKING LESS AND LESS
AND THE THUNDER POTENTIAL IS LOOKING LOWER.
LATEST 18Z AND 00Z MESOSCALE MODEL GUIDANCE AND THE HIGH RESOLUTION
HRRR MODEL RUNS HAVE SLOWED THE APPROACH OF THIS CONVECTIVE LINE A
FEW HOURS FROM PREVIOUS RUNS...AND EXTRAPOLATION OF THE CURRENT LINE
POSITION SUGGESTS CONVECTION WILL ARRIVE IN FAR WESTERN NY AROUND
08Z-09Z...THEN SPREAD TO THE EASTERN LAKE ONTARIO REGION BY 12Z.
HAVE ADJUSTED TIMING IN THE GRIDDED FORECASTS AND ZFP BY AN HOUR OR
TWO TO ACCOUNT FOR THESE LATEST TIMING THOUGHTS. SHOULD BE DRY IN
WESTERN NY UNTIL ABOUT 3AM...AND THE ENTIRE NIGHT EAST OF THE
GENESEE RIVER.
WITH AN INCREASING SSW BREEZE OVERNIGHT IT WILL STAY MILD...WITH
LOWS ONLY IN THE UPPER 60S ON THE LAKE PLAINS AND LOWER 60S WELL
INLAND.
ON FRIDAY...THE FRONT SHOULD MOVE QUICKLY THROUGH THE REGION WITH
SHOWERS AND THUNDERSTORMS ENDING FROM WEST TO EAST DURING THE
MORNING.
OTHERWISE...STRATO-CU CLOUDS WILL QUICKLY SPREAD OUT UNDER AN
INVERSION AND MOIST LOW LEVEL AIRMASS. ANY MORNING CLEARING JUST
BEHIND THE COLD FRONT SHOULD THEREFORE BE REPLACED BY AT LEAST
MOSTLY CLOUDY CONDITIONS FOR THE MAJORITY OF WESTERN NY UNDER AN
UPSLOPE NW FLOW.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
DRY AND COOL WEATHER IS EXPECTED THROUGH THIS WEEKEND WITH
TEMPERATURES BELOW NORMAL. ON FRIDAY EVENING A DEEP SURFACE
LOW...NEAR 990MB...WILL BE LOCATED OVER SOUTHERN HUDSON BAY WITH
COLD FRONT EXTENDING SOUTHEAST TO NEW ENGLAND THEN SOUTHWEST ACROSS
DOWNSTATE NY AND THEN SOUTHERN PA. BY THEN ALL OF THE FORECAST AREA
SHOULD BE CLEAR OF SHOWER AND THUNDERSTORM ACTIVITY WITH THE FRONT
TO THE EAST. A SURFACE HIGH WILL BE CENTERED OVER IOWA AND RIDGING
EAST ACROSS WESTERN NY. COLD AIR ADVECTION WILL BE IN PLACE OUT OF
THE NORTHWEST WITH CLEAR SKIES AND DRYING MOISTURE PROFILES.
THE 12Z GFS INDICATES THE DEEP UPPER LOW COUPLED ABOVE THE SURFACE
LOW OVER SOUTHERN HUDSON BAY WILL FURTHER DEEPEN THROUGH SATURDAY
WITH A BROAD TROUGH SETTLING OVER THE EASTERN TWO-THIRDS OF THE
COUNTRY. WITHIN THIS COOL AND DRY AIRMASS...PRECIPITABLE WATERS
FALLING TO AROUND A HALF INCH...NO PRECIPITATION IS EXPECTED FOR THE
AREA. LIMITED PERIODS OF CLOUDINESS WILL OCCUR WITH PASSAGE OF ANY
WEAK SHORTWAVES MOVING THOUGH THE TROUGH AND...ON A MESOSCALE
LEVEL...DOWNWIND OF THE LAKES. 850MB TEMPS WILL FALL TO BETWEEN +5C
AND +9C SATURDAY AND SUNDAY. THESE COOL TEMPS ALOFT COMBINED WITH
LAKE TEMPS AROUND +24 WILL PRODUCE LAKE EFFECT STRATOCU BUT MOISTURE
TOO LIMITED FOR PRECIP.
FOR TEMPERATURES...NORMAL HIGHS RUN IN THE UPPER 70S AND LOWS IN THE
LOW 60S FOR MID AUGUST. THE COOL AIRMASS SETTLING OVER THE STATE
WILL KEEP HIGHS AND LOWS SATURDAY AND SUNDAY 5 TO 10 DEGREES BELOW
NORMAL. HIGHS RUNNING IN THE LOWER 70S MOST LOCATIONS WITH UPPER 60S
IN THE SOUTHERN TIER AND TUG HILL. LOWS WILL BE SIMILARLY BELOW
NORMAL FALLING INTO THE UPPER 40S TO LOW 50S EACH NIGHT AWAY FROM
THE LAKES WITH MID TO UPPER 50S NEAR THE LAKE SHORES.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
MONDAY WILL START WITH THE REGION STILL UNDER THE SEASONABLY COOL
WEATHER PATTERN FROM THE WEEKEND. THE 12Z MODELS THEN SHOW BY
TUESDAY AN APPROACHING UPPER LEVEL DISTURBANCE AND EXPANSION OF THE
WEST COAST RIDGE TO THE EAST. THIS WILL FINALLY HELP TO LIFT THE
EASTERN TROUGH BACK INTO CANADA AND RESULT IN A WARMER/MOISTENING
SOUTHWEST FLOW DEVELOPING ACROSS THE STATE UNDER A MORE ZONAL/WAVY
FLOW OVER THE GREAT LAKES.
A POSSIBLE WEAK SURFACE TROUGH/FRONT LOOK POSSIBLE TO CROSS THE
REGION SOMETIME MONDAY NIGHT INTO TUESDAY NIGHT SET OFF BY THE UPPER
DISTURBANCE. INCLUDED A SLIGHT CHANCE FOR SHOWERS EARLY IN THE WEEK
TO COVER FOR THIS AND ANOTHER SLIGHT CHANCE ON THURSDAY WITH ANOTHER
FRONT WORKING TOWARD THE AREA. BEHIND THE EARLY WEEK SYSTEM WE WILL
TRANSITION FROM COOLER WEATHER BACK TO MORE SEASONABLE TEMPERATURES
BY THURSDAY. DAILY HIGHS WILL CLIMB BACK TO NEAR OR SLIGHTLY ABOVE
NORMAL...UPPER 70S/LOW 80S...BY THE END OF NEXT WEEK. LOWS WILL ALSO
NUDGE UP HIGHER WITH DEWPOINTS RUNNING IN THE MID TO UPPER 50S.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
THROUGH 06Z...RADAR SHOWS BROKEN AND GENERALLY LIGHT SHOWERS
UPSTREAM WITH THE FRONT. EXPECT LAKE ERIE TO PROVIDE SOME MOISTURE
ENHANCEMENT...BUT EVEN WITH THIS THERE SHOULD ONLY BE A BRIEF
PERIOD OF RAIN SHOWERS NEAR THE FRONTAL PASSAGE. AHEAD OF THE
FRONT...EXPECT CIGS/VSBY TO REMAIN IN THE VFR CATEGORY...EVEN AS
SHOWERS MOVE IN. WITH THE FRONT...SURFACE WINDS WILL SHIFT TO THE
NW...AND THIS MAY BRING A BRIEF PERIOD WHERE CIGS LOWER WHILE RAIN
SHOWERS LINGER. TSTMS CANNOT COMPLETELY BE RULED OUT...BUT ANY
SHOULD BE ISOLATED IN NATURE.
BASED ON VAD WIND PROFILE AND RAP FORECASTS....THERE WILL BE A
BRIEF PERIOD OF 30 TO 40 KT WINDS DOWN TO AROUND 1500 FEET THROUGH
DAYBREAK. WHILE MARGINAL...WILL CARRY A FEW HOURS OF LLWS SINCE
THIS IS NOT EXPECTED TO MIX DOWN TO THE SURFACE READILY.
FOLLOWING THE PASSAGE OF THE COLD FRONT EXPECT THE VFR LEVEL DECK TO
TEMPORARILY SCATTER OUT FRIDAY MORNING...ONLY TO FILL BACK IN AGAIN
WITH DAYTIME HEATING AS MOISTURE BECOMES TRAPPED BENEATH THE
SUBSIDENCE INVERSION. EXPECT MOST IF NOT ALL OF THIS POST-FRONTAL
CLOUD COVER TO BE VFR IN THE 035-050 KFT RANGE. THIS DECK SHOULD
SLOWLY SCATTER OUT TONIGHT AS WINDS OFF THE LAKES DIMINISH...AND
DRIER AIR MOVES IN.
OUTLOOK...
SATURDAY...POSSIBLE MVFR/IFR IN FOG EARLY OTHERWISE VFR.
SUNDAY...VFR.
MONDAY...CHANCE OF SHOWERS/TSTMS. MAINLY VFR.
TUESDAY...VFR.
&&
.MARINE...
A COLD FRONT WILL CROSS THE LOWER LAKES TONIGHT ALONG WITH THE
LIKELIHOOD OF A 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.
FINE BOATING CONDITIONS ARE THEN EXPECTED FOR THE WEEKEND.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...ZAFF
NEAR TERM...HITCHCOCK/ZAFF
SHORT TERM...SMITH
LONG TERM...SMITH
AVIATION...APFFEL
MARINE...ZAFF
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
155 AM EDT FRI AUG 17 2012
.SYNOPSIS...
COLD FRONT PASSES THIS AFTERNOON INTO THIS EVENING. WEAK HIGH
PRESSURE OVER WEEKEND...WITH DISTURBANCE ALOFT PASSING SUNDAY.
ANOTHER HIGH PRESSURE BUILDS NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
915 PM UPDATE. VERY DIFFICULT. IMPRESSIVE MCS DROPPING EAST
SOUTHEAST INTO WESTERN KENTUCKY AT TIME WILL SURELY DISRUPT THE
MODEL CONSENSUS OF TRYING TO REFOCUS CONVECTION NORTHWARD ALONG
FRONT LATER ON TONIGHT. HAVE ADJUSTED POPS OVERNIGHT TO RAISE POPS
IN THE WEST AND SOUTHWEST FOR EASTWARD EXTENSION OF THE DYING MCS BY
THAT TIME. IN TURN...WHILE KEEPING REDEVELOPMENT FURTHER NORTH AS
THE FRONT MAKES IT TO OUR CWA BORDER BY 12Z...HAVE CUT CAT POPS TO
LIKELY. THIS MAY STILL BE TOO GENEROUS...BUT DID NOT WANT TO MAKE
WHOLESALE CHANGES THIS FAR OUT. OTHERWISE...WILL CONTINUE PLAYING AN
EARLY MORNING BAND OF CONVECTION SURGING OUR AHEAD OF THE FRONT...
AND A BETTER AFTERNOON CONVECTIVE BAND WITH THE FRONT AS IT MOVES
ACROSS.
PREVIOUS DISCUSSION...
MORNING COMPLEX CONT TO WEAKEN AS IT RUNS IN TO DRY AIR IN MID
LVLS AND AWAY FROM COLD FRONT/UPR SUPPORT. RUC AND RAP DO INDICATE
A SLIGHT MOISTENING ACROSS PERRY/MORGAN 22-00Z WHICH MAY BE ENOUGH
FOR AN ISO SHRA/TSRA AS REMNANTS...AT LEAST ALOFT...MOVE ACROSS E
OH. THUS ELECTED TO CODE UP SCHC ACROSS PERRY DURING
AFOREMENTIONED TIME FRAME.
OTHERWISE WILL BE WAITING FOR APPROACH OF UPR TROF AND ASSOCIATED
SFC FRONT HEADING INTO TOMORROW. LIKED TIMING OF PREV FCST WHICH
IS IN GOOD AGREEMENT WITH NAM. LOOKS LIKE AREA WILL BE DEALING
WITH TWO POSSIBLE BANDS OF PCPN...PREFRONTAL BAND IN THE MORNING
FOLLOWED BY A ROUND OF CONVECTION MORE WITH ACTUAL FRONT. HAVE SFC
FRONT JUST ENTERING SE OH AT 12Z WITH PREFRONTAL BAND HAVING
TRAVERSED THRU SE OH/NE KY INTO CENTRAL WV...AIDED MORE BY DECENT
OMEGA ARND H7 AND LLVL WAA. EXPECT THIS TO FIZZLE OUT AS IT HEADS
INTO MTNS BY MID MORNING. WILL KEEP THUNDER IN GIVEN ELEVATED
INSTABILITY. MEANWHILE FRONT MAY SLOW DOWN BRIEFLY TOMORROW WITH
ANOTHER ORGANIZED BAND OF INITIALLY FRONTAL CONVECTION MOVING
ACROSS THE AREA AFTER A BRIEF BREAK FOLLOWING MORNING CONVECTION.
THIS LOOKS TO PROPAGATE OUT AHEAD OF BOUNDARY IN AFTN AND EXIT
MTNS BY 21Z AS DEEPER MOISTURE IS EXODUS. WILL HANG SOME LOW POPS
BACK A FEW HRS WITH SFC FRONT ONLY CROSSING OH RVR BY SAID TIME.
WILL GO WITH HIGHER NUMBERS TONIGHT WITH BL FLOW INCREASING LATE.
HIGHS TOMORROW TRICKY. WILL LEAN TOWARD LOWER NUMBERS FROM
GUIDANCE.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
COLD FRONT EXPECTED TO BE EXIT THE EASTERN MOUNTAINS AT THE
BEGINNING OF THE PERIOD WITH PCPN DECREASING FROM CHANCE TO SLIGHT
CHANCE THROUGH 12Z SATURDAY. DEWPOINTS WILL LINGER INTO THE LOWER
60S EXTREME NORTHEAST...UPPER TO MID 50S EAST OF THE OH
RIVER...DROPPING TO THE LOW 50S ACROSS SOUTHEAST OH BY SATURDAY
MORNING.
HIGH PRESSURE BUILDS BEHIND THE FRONT WITH DRIER AIR TO PROVIDE
PLENTY OF SUNSHINE SATURDAY. WITH ABUNDANT LINGERING MOISTURE OVER
THE EASTERN MOUNTAINS...KEPT SLIGHT CHANCE FOR AFTERNOON SHOWERS.
WITH THE EXPECTED WIDESPREAD CLEARING SATURDAY AND SUNDAY
NIGHTS...DENSE FOG IS A GOOD BET OVER AREAS THAT RECEIVE RAIN AND
ALONG RIVER VALLEYS DUE TO NEAR CLAM FLOW.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
HIGH PRESSURE STRENGTHENS THROUGH MID WEEK PROVIDING MOSTLY CLEAR
SKIES AND NORMAL TEMPERATURES. HOWEVER...THE GFS SUGGEST UPPER LEVEL
SYNOPTIC LIFT ASSOCIATED WITH AND UPPER LEVEL JET...ALTHOUGH
MOISTURE IS LIMITED PER PWATS AROUND 0.75 INCHES...FEW SHOWERS COULD
DEVELOP ONCE AGAIN OVER THE EASTERN MOUNTAINS SUNDAY AFTERNOON.
OTHERWISE...DRY WEATHER AND PLEASANT TEMPERATURES WILL PREVAIL
THROUGH THE END OF THE WEEK.
SOME WARM AIR ADVECTION NOTICED AT H850 FROM 11C TO 14-16C FROM
THE GFS/ECMWF UNDER WEAK SOUTHERLY FLOW FROM WED THROUGH THE END
OF THE WEEK. THEREFORE...INCREASED TEMPS TO THE MID TO UPPER 80S
SIMILAR TO HPC AND GMOS FROM WEDNESDAY THROUGH END OF THE PERIOD.
USED HPC TEMPS...WITH SOME TWEAKS DAY 5 THROUGH DAY 7.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
PREFRONTAL TROF ALREADY DROPPING INTO SOUTHEAST OHIO 06Z TO 12Z.
YET...SURFACE FRONT FURTHER WEST. WITH THE MCS COMPLEX IN THE TN
VLY STEALING THE OVERNIGHT SHOW...WAS SLOWER IN INCREASING POPS AND
DROPPING CEILINGS. HAVE SOME SCATTERED SHOWERS...NO THUNDER...INTO
OHIO RIVER COUNTIES DURING THE PREDAWN HOURS. HAVE CEILINGS MOSTLY
5 TO 10 THSD FT BKN BY 10Z.
STILL STRONG SUPPORT ALOFT PASSING DURING THE LATE MORNING AND EARLY
AFTERNOON. TRIED TO INCREASE POPS 14Z TO 16Z AND SPREAD RAPIDLY
NORTHEAST INTO THE CKB AND EKN AREA BY 16-18Z...THEN NUDGING EAST IN
THE MOUNTAINOUS COUNTIES BY 21Z...WHILE LOWERING POPS IN SOUTHEAST
OHIO AND THE PKB VCNTY. YET...THE SURFACE FRONT WILL STILL BE
APPROACHING THE OHIO RIVER...LIKELY NOT REACHING CRW UNTIL AROUND
00Z. SOME LESS WIDESPREAD CONVECTION POSSIBLE WITH THE FRONT ITSELF.
HAVE CEILINGS 2 TO 4 THSD FT BKN AND VSBY NEAR 3 MILES IN THE
CONVECTION.
LOW CONFIDENCE IN WHAT HAPPENS TO THE CEILINGS THIS
EVENING...ESPECIALLY EKN TO CRW ON SOUTH. THE DRIER AIR SHOULD
PENETRATE THE CKB TO PKB CORRIDOR...BUT HAVE CEILINGS DEVELOPING AT
1 TO 2 THSD FT BKN AND VSBY 3 TO 5 MILES 00Z TO 03Z IN THE
SOUTH...WITH LOWER CONDITIONS POSSIBLE AFTER 03Z SATURDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z SATURDAY...
FORECAST CONFIDENCE: LOW.
ALTERNATE SCENARIOS: THE TIMING AND THE AREAL COVERAGE OF THE
SHOWERS/THUNDERSTORMS TODAY WILL VARY. FOG AND LOW CLOUDS MAY FORM
AFTER FRIDAY EVENING THAN FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE FRI 08/17/12
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
CRW CONSISTENCY H H H H H H H M M M H H
HTS CONSISTENCY H H H H H H M M M M H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY L L M M H H H H H H H H
PKB CONSISTENCY H H H H H H H M H H H H
CKB CONSISTENCY H H H H H H H H M M H H
AFTER 06Z SATURDAY...
IFR POSSIBLE IN CEILINGS AND VSBY OVER SOUTHERN WEST VIRGINIA IN
POSSIBLE STRATUS AND/OR FOG.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/ARJ/30
NEAR TERM...JMV/30
SHORT TERM...ARJ
LONG TERM...ARJ
AVIATION...KTB
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1257 AM EDT FRI AUG 17 2012
.SYNOPSIS...
A COLD FRONT ACROSS THE WESTERN GREAT LAKES WILL MOVE EAST ACROSS
THE LOCAL AREA TONIGHT. THE FRONT WILL MOVE TO THE EAST COAST
FRIDAY ALLOWING HIGH PRESSURE TO BEGIN BUILDING OVER THE REGION
FROM THE WEST. THE HIGH IS EXPECTED TO LINGER OVER THE REGION
THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
COLD FRONT CONTINUES TO PUSH EAST INTO INDIANA THIS EVENING AND
WILL MOVE ACROSS THE FORECAST AREA LATER OVERNIGHT AND TUE
MORNING. RADAR SHOWING MOST OF CONVECTION IN MICHIGAN. MOST MODELS
SUGGESTING SOME ADDITIONAL CONVECTION DEVELOPING NEAR THE FRONT
AND MOVE INTO NRN OHIO OVERNIGHT...BUT WILL HAVE TO SEE GIVEN
THUNDERSTORM COMPLEX SOUTHWEST OF THE AREA. FOR NOW LEFT THE
CATEGORICAL POPS OVER THE AREA AS THINKING MOST LOCATIONS WILL SEE
AT LEAST A BRIEF PERIOD OF SHRA/TS WITH THE FRONTAL PASSAGE. MADE
SMALL ADJUSTMENTS TO TEMPS BUT NOTHING SIGNIFICANT FOR THE
OVERNIGHT WITH LOWER TO MID 60S ACROSS THE AREA.
PREVIOUS DISCUSSION...
THE AREA OF SHOWERS MOVING TOWARD NW OH CONTINUES TO BREAK UP BUT
HAVE STARTED TO SEE SOME NEW DEVELOPMENT IN FAR NE OH ALONG A LAKE
BREEZE BOUNDARY. THESE TRENDS WILL LIKELY CONTINUE FOR THE
REMAINDER OF THE AFTERNOON WITH AN INCREASE IN ACTIVITY IN THE
EAST AND A DECREASE IN THE WEST. HRRR AND CONVECTIVE SREF CONTINUE
TO SHOW ANOTHER LINE OF STORMS DEVELOPING JUST TO THE WEST OF THE
AREA TOWARD 00Z AHEAD OF AN APPROACHING COLD FRONT. THIS IS THE
LINE THAT WILL LIKELY BRING PRECIP TO THE ENTIRE AREA OVERNIGHT.
WILL CONTINUE WITH CATEGORICAL PRECIP CHANCES WITH MOST AREAS
SEEING UP TO A HALF INCH OF RAINFALL. THE PRECIP WILL END FROM
WEST TO EAST AFTER MIDNIGHT AS THE FRONT PULLS OUT. THICK CLOUDS
HAVE OVERSPREAD THE AREA AND THE THREAT FOR SEVERE WEATHER APPEARS
MINIMAL. BETTER INSTABILITY REMAINS TO THE SW AND THAT IS WHERE
ANY SEVERE WEATHER WILL LIKELY OCCUR.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/...
THE COLD FRONT WILL BE GONE BY DAYBREAK AND MOST OF THE PRECIP
ALONG WITH IT. COULD SEE SOME SHOWERS IN THE EAST AND SOUTH
THROUGH MIDDAY BUT AFTER THAT IT SHOULD BE TOO DRY FOR MORE
PRECIP. 850 MB TEMPS WILL DIP TO AROUND PLUS 8 BY FRIDAY EVENING
SO THIS WILL BE A COLD AIRMASS. WILL LIKELY SEE A FAIR AMOUNT OF
LAKE EFFECT STRATO CU THROUGH SATURDAY. SOME INDICATION FROM THE
MODELS OF ANOTHER WEAK FRONT APPROACHING FROM THE NORTH LATE
SUNDAY AND SUNDAY NIGHT. WILL GO WITH A VERY SMALL MENTION OF
SHOWERS IN THE FAR NORTH BUT REALLY DON`T THINK THIS WILL BE A BIG
DEAL. TEMPS WILL AVERAGE WELL BELOW NORMAL AND LATER SHIFTS WILL
HAVE TO WATCH FOR POSSIBLE 40S FOR LOWS SUNDAY MORNING. HAVE USED
A BLEND OF GUIDANCE DURING THE PERIOD.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
INITIALLY LONG RANGE PART OF FORECAST SHOULD START OFF COOL AND
SOMEWHAT CLOUD. THE BIG QUESTION IS WHETHER THE UPPER TROF OVER THE
AREA WILL CAUSE ENOUGH FORCING TO PRODUCE A FEW SHRA...ESPECIALLY IN
THE SNOWBELT OR WHETHER SURFACE HIGH PRESSURE WILL KEEP THINGS DRY.
PREFERENCE IS TO CARRY AT LEAST A SLIGHT CHANCE FOR THE NE PART OF
THE AREA MON THEN GO DRY TUE AS THE UPPER TROF WEAKENS AND SHIFT
EAST.
WED LOOKS DRY AS TEMPS WARM BACK TO NORMAL. THE MODELS DIFFER BY THU
SO MUCH GREATER UNCERTAINTY IN OVERALL FORECAST. THUS FORECAST WILL
LARGELY BE INFLUENCED BY BEST COLLABORATION WITH SURROUNDING WFO`S.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
COLD FRONT MOVING INTO THE NORTHWEST CORNER OF OHIO THIS HOUR WITH
LIGHT RAIN SHOWERS IN VICINITY OF THE BOUNDARY. NOT COMPLETELY OUT
OF THE QUESTION TO GET THUNDER TO DEVELOP OVERNIGHT WITH THE FRONT
ACROSS THE REGION BUT FOR NOW WILL LEAVE OUT. CONDITIONS ARE VFR
ON THE EAST SIDE OF THE FRONT WITH PATCHY MVFR VISIBILITIES AND
CIGS IN LIGHT RAIN BEHIND. FRIDAY EXPECT MVFR CONDITIONS ACROSS
MUCH OF THE AREA IMPROVING TO VFR DURING THE LATE MORNING AND
EARLY AFTERNOON FROM THE WEST.
.OUTLOOK...VFR EXCEPT FOR A CHANCE OF MVFR CEILINGS EXTREME
NE OH/NW PA MONDAY AND TUESDAY MORNING.
&&
.MARINE...
COLD FRONT WILL MOVE INTO THE CENTRAL GREAT LAKES TONIGHT. EXPECT TO
SEE SOUTHWEST WINDS TO REMAIN IN THE 10 TO 20 KNOT RANGE. HOWEVER
THE EASTERN HALF OF THE LAKE COULD SEE SLIGHTLY HIGHER FOR A COUPLE
HOURS JUST AHEAD OF THE FRONT AFTER MIDNIGHT. WILL THEN AWAIT THE
WIND SHIFT TO CLEAR LAKE ERIE NEAR OR SHORTLY AFTER SUNRISE.
NORTHWESTERLY WINDS MAY BE JUST STRONG ENOUGH WITH THE LONGER FETCH
TO PROVIDE SMALL CRAFT CONDITIONS FOR THE EASTERN HALF TO TWO THIRDS
OF THE LAKE INTO FRIDAY AFTERNOON. WILL LET THE NEXT SHIFT MONITOR
THIS POTENTIAL OVERNIGHT TO DECIDE IF WE WILL REACH THE CRITERIA.
HIGH PRESSURE WILL THEN CONTROL THE LAKE WITH A LIGHT WEST TO
NORTHWEST WIND EXPECTED THROUGH THE WEEKEND. SOUTHWESTERLY WINDS
SHOULD RETURN BY MONDAY AFTERNOON AND SHOULD PERSIST INTO TUESDAY
AHEAD OF THE NEXT COLD FRONT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KUBINA
NEAR TERM...ABE/KUBINA
SHORT TERM...KUBINA
LONG TERM...ADAMS
AVIATION...TK
MARINE...MULLEN
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1252 AM CDT FRI AUG 17 2012
.MESOSCALE UPDATE...
LINE OF STRONG/SEVERE STORMS NOW NEARING ALABAMA BORDER WHILE
CONTINUING TO SINK SOUTH...WITH RAIN SHIELD EXTENDING ALL THE WAY
TO THE KENTUCKY BORDER. FLASH DENSITY/LMA REMAINS QUITE HIGH BUT
MOSTLY NEGATIVE STRIKES NEAR ALABAMA BORDER. RUC SHOWING GOOD
UPPER DIFFLUENCE OVER SOUTHERN MIDDLE TENNESSEE AT 05Z.
EXPECT LINE TO CONTINUE SOUTH BOUND AND SHOULD EXIT MID STATE
AROUND 0630Z BUT RAIN SHIELD WILL REMAIN OVER REMAINDER OF THE MID
STATE FOR THE NEXT SEVERAL HOURS.
MSAS HAS COLD FRONT EXTENDING FROM SOUTHWEST INDIANA DOWN THROUGH
FAR SOUTHERN ILLINOIS INTO SOUTHEAST MISSOURI. TROPOSPHERE HAS
BEEN WORKED OVER FROM TONIGHTS CONVECTION. MODELS DROP FRONT
SOUTHEAST AND INTO THE MID STATE DURING THE DAY TODAY WITH MORE
SHOWERS AND STORMS. STORMS HAVE ALREADY RE-FIRED IN SOUTHWEST MISSOURI.
BOYD
&&
.PREV DISCUSSION... /ISSUED 943 PM CDT THU AUG 16 2012/
MESOSCALE UPDATE...STORMS MOVING INTO NW AND NC MID TN WITH
PRETTY GOOD PUSH OF WIND. PER DISCUSSION WITH SPC...NOT PLANNING A
WATCH AT THIS TIME...ALTHOUGH WE WILL HAVE SOME SEVERE WIND
POTENTIAL FOR ANOTHER HOUR OR 2. HOPEFULLY AS SPC DISCUSSION
INDICATES...THE STORM SUPPORT WILL DIMINISH AS THE OUTFLOW PUSHES
SOUTHWARD. FOLKS IN THE NASHVILLE METRO AREA SHOULD EXPECT SOME
GUSTY WINDS SOON.
13
PREV DISCUSSION... /ISSUED 758 PM CDT THU AUG 16 2012/
MESOSCALE UPDATE...WE ARE CLOSELY MONITORING STORMS OVER WEST KY
WITH HIGH WINDS TO 70 MPH REPORTED IN THE PAH AREA. GUST FRONT
WILL PUSH TO OUR NW COUNTIES BY 0130Z. IN ADDITION TO THESE
STORMS...SEVERAL SINGLE CELL PULSE STORMS HAVE POPPED UP OVER MID
TN THIS EVENING...WITH 1 INCH DIAMETER HAIL REPORTED IN SOUTH
RUTHERFORD COUNTY.
THE EVENING OHX SOUNDING SHOWED 1228 CAPE AND -5 LIFTED INDEX.
CONDITIONS SHOULD STABILIZE SOME WITH SUNSET...SO THE PULSE
ACTIVITY SHOULD TREND DOWNWARD IN INTENSITY. MAIN CONCERN WILL BE
STRONG GUSTY WINDS OVER THE NW COUNTIES THROUGH THE NEXT FEW
HOURS. ALSO...SOME VERY HEAVY DOWNPOURS MAY CAUSE SOME STREET
FLOODING.
FORECAST PRODUCTS HAVE ALREADY BEEN UPDATED TO INCREASE POPS NW.
13
PREV DISCUSSION... /ISSUED 249 PM CDT THU AUG 16 2012/
DISCUSSION...FRONT IS TO THE NW OVER CNTRL MO MOVING SEWD WHILE
AN OLD DISSIPATING FRONT IS TO THE SOUTH OVER GA/AL/MS. THUS THESE
2 FEATURES SERVE TO FOCUS CONVECTION OVER THE OH VALLEY AND DEEP
SOUTH. NO SIGNIFICANT CONVECTION PRESENTLY OVER THE MIDSTATE.
MAINILY DUE TO THE MID LEVEL INVERSION AND LACK OF DEEP MOISTURE.
AS THE FRONTAL ZONE MOVES CLOSER LATE TODAY WE MAY START TO PICK
SOME CONVECTION IN THE EXTREME NW COUNTIES. THAT ACTIVITY WILL
SPREAD EWD ACROSS THE AREA BUT WILL THIN A GOOD BIT IN THE EAST
WHERE MOISTURE IS NOT AS PLENTIFUL. THE FRONT(WIND SHIFT) IS
EXPECTED TO ARRIVE IN THE NWRN COUNTIES BETWEEN 08Z AND 09Z WITH
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORM ALONG AND AHEAD OF
THE FRONT. IT SHOULD BE EAST OF KBNA BY 17Z AND AT KCSV 19Z TO
20Z.
SHOWERS AND THUNDERSTORMS WILL DIMINISH FROM THE WEST FRIDAY NIGHT
AS DRIER AIR PUSHES INTO THE MIDSTATE. HOWEVER, THE FRONT DOES NOT
PUSH FAR ENOUGH SOUTH TO TOTALLY PUSH ALL OF THE PRECIP OUT OF THE
AREA. I`VE LEFT A SLIVER OF POPS OVER THE SRN MOST AND SERN MOST
COUNTIES FOR SAT AND SUN.
THEN A 2ND SURGE OF DRY AIR PUSHES IN SUN NGT AND MON MOVING THE
FRONT AND ITS MOISTURE FURTHER INTO THE DEEP SOUTH. THINK THE GFS
IS A BIT TOO FAST IN BRINGING BACK MOISTURE IN THE WEST AND HAVE
KEPT THE AREA DRY THROUGH WED NGT. ANOTHER FRONTAL SYSTEM
APPROACHES ON THU SO I`VE INCLUDED A 20 POP FOR THU AND THU NGT.
SEVERE...SPC HAS OUTLOOKED A SLGT CHC AREA OVER THE WRN OH VALLEY.
ANY SVR CONVECTION THAT FORMS IN THIS AREA WILL LIKELY DROP BELOW
SVR LIMITS AS THE FRONT MOVES INTO THE NW COUNTIES AFTER MIDNIGHT.
THEN WITH THE FRONT OVER THE ERN PORTION OF THE MIDSTATE TOMORROW
AFTN WHEN THE DIURNAL CYCLE RAMPS UP AGAIN THEY HAVE OUTLOOKED
AN AREA OVER THE SERN HALF OF MIDDLE TENNESSEE PLUS NRN MS/AL/GA.
BIGGEST THREAT WOULD BE DAMAGING WINDS.
HEAVY RAIN...HPC IS OUTLOOKING LESS THAN AN INCH OF RAIN FOR THIS EVENT.
WHILE THERE WILL BE SIGNIFICANT MOISTURE AHEAD OF THE FRONT...THE
FRONT IS EXPECTED TO MOVE AT A MODEST PACE ACROSS THE AREA W/O
GETTING "HUNG UP". ALSO...MUCH OF THE UPPER SUPPORT IS WELL NORTH
OF THE AREA.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
01
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
406 AM CDT FRI AUG 17 2012
.SHORT TERM...
SCATTERED MID LEVEL SHOWERS CONTINUE TO DEVELOP ACROSS PORTIONS OF
THE BIG COUNTRY AND RED RIVER VALLEY EARLY THIS MORNING. ABUNDANT
MID LEVEL MOISTURE COMBINING WITH A LOW LEVEL JET OF 25 TO 30 KTS.
ITS ABOUT THIS TIME THAT CONVECTION EXPANDED YESTERDAY...AND EVEN
WITHOUT THE STRONGER SHORTWAVE THAT WE HAD PASSING...WOULD NOT BE
SURPRISED TO SEE CONVECTIVE COVERAGE EXPAND A LITTLE MORE AT SUNRISE
THIS MORNING AS WELL.
SURFACE FRONTAL BOUNDARY DROPPING THROUGH OKLAHOMA THIS
MORNING...AND SEEMS TO HAVE A DECENT PUSH WITH IT SO FAR.
OBSERVATIONS ARE SHOWING SOME 15 TO 20 KT NORTHEAST WINDS....WITH
DEWPOINTS IN THE 40S AND LOWER 50S. LATEST RUC AS WELL AS THE 4KM
WRF MODEL FROM TEXAS TECH...SHOW THIS BOUNDARY MAKING IT WELL INTO
WEST CENTRAL TEXAS TODAY. IF THIS DOES HAPPEN...THEN CONVECTION WILL
END UP FARTHER SOUTH THAN WE ORIGINALLY THOUGHT. THUS...HAVE BOOSTED
THE POPS ACROSS THE CENTRAL COUNTIES...ROUGHLY BETWEEN ABILENE AND
SAN ANGELO...A LITTLE. THIS ACTIVITY WILL CONTINUE INTO THE
EVENING HOURS.
TONIGHT...MODELS SHOW A STRONGER SHORTWAVE MOVING TOWARDS WEST
CENTRAL TEXAS IN THE NORTHWEST FLOW ALOFT. COMBINE THIS WAVE WITH
WHATS LEFT OF THE SURFACE BOUNDARY...AND EXPECT SCATTERED CONVECTION
TO CONTINUE. WITH THE LOW LEVEL JET STRONGER TONIGHT...BEST POPS
WILL SHIFT A LITTLE TO NORTH OF THE BOUNDARY.
.LONG TERM...
LOOKS LIKE A WET PATTERN SETTING UP THIS WEEKEND ACROSS WEST CENTRAL
TEXAS. BENEFICIAL RAINFALL IS NEEDED AS MUCH OF THE CWFA IS
CURRENTLY EXPERIENCING MODERATE TO SEVERE DROUGHT CONDITIONS(AS OF
AUGUST 14)...ACCORDING TO THE US DROUGHT MONITOR. THE MAIN PLAYERS
WILL BE A SLOW MOVING COOL FRONT...OTHER MESOSCALE BOUNDARIES IN THE
AREA AND WEAK UPPER LEVEL FORCING. ALSO...SLOW MOVING STORMS AND
PWAT VALUES OF 1.5 TO 2 INCHES WILL BRING LOCALLY HEAVY RAINFALL.
LOOKS LIKE RAINFALL AMOUNTS WILL AVERAGE 0.5 TO 1.5 INCHES...WITH
LOCALLY HIGHER AMOUNTS POSSIBLE...ESPECIALLY ACROSS THE NORTHERN AND
EASTERN CWFA. ALSO...AN ISOLATED SEVERE STORM OR TWO ARE POSSIBLE
ACROSS THE BIG COUNTRY MAINLY SATURDAY AFTERNOON AND EVENING. THE
MAIN HAZARDS WILL BE LARGE HAIL AND DAMAGING WINDS. THE ABUNDANT
CLOUD COVER AND RAINFALL WILL KEEP TEMPERATURES DOWN SATURDAY AND
SUNDAY. HIGHS WILL BE IN THE UPPER 80S TO MID 90S.
LOOKS LIKE MAINLY DRY WEATHER RETURNING NEXT WEEK AS THE UPPER LEVEL
RIDGE BUILDS BACK OVER THE AREA. THE GFS MODEL IS STILL INDICATING A
POSSIBLE MCS MOVING SOUTHEAST ACROSS THE SOUTHERN PLAINS MONDAY
NIGHT AND TUESDAY MORNING. WILL KEEP THE FORECAST DRY FOR
NOW...HOWEVER WILL NEED TO MONITOR FUTURE MODEL OUTPUT. HIGHS WILL
WARM BACK INTO THE MID 90S EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 95 72 94 71 90 / 40 40 50 50 40
SAN ANGELO 100 75 95 71 92 / 20 30 40 40 30
JUNCTION 96 74 96 72 94 / 10 20 30 30 30
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
07/21
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1120 PM MDT THU AUG 16 2012
.AVIATION...06Z TAFS...
VFR EXPECTED OVER ALL TERMINALS THROUGH FRIDAY NIGHT UNDER NW FLOW
ALOFT. AND SFC HIGH OVER THE CENTRAL PLAINS INTO THE MIDWEST. -RE-
&&
.PREV DISCUSSION... /ISSUED 835 PM MDT THU AUG 16 2012/
.UPDATE...
REMOVED SLIGHT CHANCE POPS AND DECREASED CLOUD COVER FOR THE
OVERNIGHT PERIOD ACROSS THE SOUTHERN PART OF THE CWA. THE 18Z GFS
WAS THE MOST BULLISH IN INCREASING LLVL RH/LOW CLOUDS ALONG
INTERSTATE 80 OVER THE PLAINS...HOWEVER THE GFS SFC DEWPOINTS WERE
AROUND 5 DEGREES TOO HIGH AT 00Z. THUS...TENDED TO SIDE WITH THE NAM
AND HRRR MODEL OUTPUT THAT SHOWED LIMITED LOW CLOUD DEVELOPMENT
OVERNIGHT.
&&
PREV DISCUSSION... /ISSUED 338 PM MDT THU AUG 16 2012/
SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT...
WIDESPREAD STRATUS HAS BEEN SLOW TO ERODE THIS AFTN OWING TO
PERSISTENT LOW-LEVEL UPSLOPE FLOW...AND A MUCH DEEPER CLOUD LAYER
THAN PREVIOUSLY THOUGHT GIVEN EARLIER RETURNS FROM THE CYS VAD
WIND PROFILE. WINDS HAVE FINALLY SHIFTED TO THE S ACROSS MUCH OF
THE AREA...MINIMIZING THE UPSLOPE COMPONENT AND ALLOWING CLOUD
COVER TO RAPIDLY DIMINISH ACROSS SOUTHEAST WY AND THE WESTERN NE
PANHANDLE. TEMPERATURES HAVE RESPONDED NICELY WHERE SIGNIFICANT
CLOUD BREAKS HAVE BEEN NOTED ON RECENT VISIBLE SATELLITE IMAGERY
WITH SOUTHEAST WYOMING SEEING TEMPERATURES CLIMB INTO THE MIDDLE
TO UPPER 60S. THE RESULTANT DESTABILIZATION WITH SLIGHTLY NEGATIVE
LIFTED INDEX VALUES...ALONG WITH LOW-LEVEL CONVERGENCE ALONG A
WEAK SURFACE TROUGH HAVE CONTRIBUTED TO SHOWER AND TSTM
DEVELOPMENT OVER THE COLORADO FRONT RANGE. THIS ACTIVITY SHOULD
SPREAD N INTO THE SNOWY AND SIERRA MADRE RANGES DURING THE LATE
AFTN AND EARLY EVE.
ACTIVE NORTHWEST FLOW ALOFT SHOULD CONTINUE INTO THE OVERNIGHT
GIVEN RECENT TRENDS IN WATER VAPOR SATELLITE IMAGERY. MULTIPLE
SHORTWAVE DISTURBANCES APPEAR TO BE EMBEDDED WITHIN THE FLOW AND
COULD AFFECT THE AREA LATER TONIGHT. MODEL GUIDANCE SUGGESTS THE
STRONGEST SUCH WAVE WILL TRACK ACROSS EAST CENTRAL WY INTO THE
NORTHERN NE PANHANDLE BETWEEN 6Z AND 12Z FRI. WEAK PVA AND 700
MILLIBAR THETA E ADVECTION IN ADVANCE OF THIS WAVE COULD HELP TO
INITIATE A FEW LIGHT RAIN SHOWERS...BUT ACTIVITY SHOULD REMAIN
QUITE ISOLATED GIVEN LIMITED MOISTURE. LINGERING CLOUD COVER MAY
LIMIT RADIATIONAL COOLING TO SOME EXTENT...WHICH COULD KEEP
TEMPERATURES UP A FEW DEGREES THROUGH TONIGHT.
MOISTURE BEGINS TO INCREASE ON FRI OVER THE WESTERN NE PANHANDLE
IN ADVANCE OF A WEAK SFC TROUGH. CONVERGENCE ALONG THIS BOUNDARY
DOES NOT APPEAR TO BE TOO IMPRESSIVE...AND MUCH OF THE AREA WILL
REMAIN IN THE SUBSIDENCE OF AN UPPER-LEVEL JET STREAK MOVING TO
THE N. DESPITE THE POTENTIAL FOR MODEST DESTABILIZATION WITH UPPER
40S AND LOWER 50S BOUNDARY LAYER DEW POINTS CONTRIBUTING TO A FEW
HUNDRED J/KG OF SBCAPE...THE RELATIVELY DRY WEATHER PATTERN AND
LIMITED DYNAMICS SUGGEST DRY CONDITIONS WILL PREVAIL ON FRIDAY
AFTN AND EVE. FEWER CLOUDS AND H7 TEMPERATURES AROUND 10C SUGGEST
AFTERNOON HIGHS MAY ONCE AGAIN TOP 80 DEGREES OVER THE HIGH PLAINS
OF SOUTHEAST WY. BEYOND FRIDAY...THE ADVANCEMENT OF DRY AIR IN THE
700 TO 300 MB LAYER ON THE EASTERN PERIPHERY OF A BUILDING UPPER-
LEVEL RIDGE OVER THE WESTERN CONUS WILL KEEP THINGS DRY THROUGH
THE REMAINDER OF THE PERIOD.
LONG TERM...SUNDAY THROUGH WEDNESDAY...
DRY AND MILD WILL BE THE MAIN STORY THROUGH THE LONG TERM
PERIOD. SUNDAY WILL START OFF UNDER DRY NORTHWEST FLOW ALOFT
WITH AN UPPER RIDGE OVER THE INTERMOUNTAIN WEST. A FEW WEAK
DISTURBANCES MAY MOVE THROUGH NORTHWEST FLOW EARLY IN THE EXTENDED
PERIOD BUT DISTURBANCES SHOULD BE WEAK AND TIMING IS UNCERTAIN.
CHANCES FOR PRECIPITATION IN THE PLAINS IS VERY LOW BUT SHOULD SEE
AT LEAST A FEW SHOWERS AND THUNDERSTORMS IN THE MOUNTAINS. RIDGE
AXIS TO SHIFT ACROSS THE NORTHERN ROCKIES BY MID WEEK KEEPING MOST
OF THE FORECAST AREA DRY BUT EXTENDED MODELS DO INDICATE A PACIFIC
SHORTWAVE MOVING THROUGH THE RIDGE. TIMING AND PLACEMENT HAVE BEEN
INCONSISTENT BETWEEN MODEL RUNS AND THE GFS AND EC SOLUTIONS NOT IN
AGREEMENT. MOST LIKELY CHANCES FOR PRECIPITATION WILL HOLD OFF UNTIL
LATE NEXT WEEK...ASSUMING SHORTWAVE TRACK IS FAR ENOUGH SOUTH TO
IMPACT THE FORECAST AREA.
FIRE WEATHER...
A COOLER AND MORE HUMID WEATHER PATTERN WILL PRECLUDE ANY NOTABLE
FIRE WEATHER CONCERNS THROUGH TONIGHT. WARMER AND DRIER CONDITIONS
WILL RETURN TO THE REGION ON FRIDAY THROUGH SUNDAY BENEATH A RIDGE
OF HIGH PRESSURE...WITH DAYTIME HIGH TEMPERATURES IN THE UPPER 70S
AND LOWER 80S OVER THE LOWER ELEVATIONS. AFTERNOON RELATIVE
HUMIDITY VALUES COULD BE AS LOW AS 13 TO 17 PERCENT ON FRIDAY AND
SATURDAY OVER THE LOWER ELEVATIONS OF CARBON COUNTY AND PORTIONS
OF THE SOUTHERN NEBRASKA PANHANDLE. GUSTY NORTH TO NORTHEAST WINDS
AT 15 TO 20 MPH COULD COMBINE WITH LOW RELATIVE HUMIDITY TO CREATE
NEAR CRITICAL FIRE WEATHER CONDITIONS OVER THE SOUTHERN PANHANDLE
ON SATURDAY AFTERNOON. WARM AND DRY CONDITIONS WILL CONTINUE
THROUGH NEXT WEEK WITH ONLY VERY SMALL CHANCES FOR SHOWERS AND
THUNDERSTORMS OVER THE MOUNTAINS. MINIMUM RELATIVE HUMIDITY VALUES
WILL BE IN THE MIDDLE TEENS EACH DAY THROUGH FRIDAY...BUT WINDS
SHOULD BE LIGHT.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...FINCH
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
1048 AM EDT FRI AUG 17 2012
.UPDATE...
DIFFICULT FORECAST FOR TODAY...WITH LITTLE FORECAST AGREEMENT WITH
THE SHORT TERM MODELS. OVERNIGHT MCS PUSHED INTO AL...WITH LARGE
AREA OF RAIN SHOWERS REMAINING ACROSS THE SOUTHERN HALF OF THE
STATE. THIS COMPLEX USHERED DECENT CLOUD COVER ACROSS THE FAR
WESTERN SIDE OF GA THIS MORNING...KEEPING A MORE STABILIZED
ENVIRONMENT OVER THAT AREA. CLOUDS ALREADY BEGINNING TO DIMINISH
THIS MORNING...BUT AS A RESULT OF THESE NOT WELL FORECAST
CLOUDS...MODELS HAVING DIFFICULTLY FINDING AN AGREEMENT ON
AFTERNOON ACTIVITY AS FRONTAL BOUNDARY APPROACHES THE REGION AND
STRONG UPPER LEVEL DISTURBANCE DROPS INTO THE STATE JUST AHEAD OF
IT. LOCAL WRF INDICATING A BUSY CONVECTIVE AFTERNOON FOR THE
STATE...WITH ISOLATED CELLS BECOMING MORE ORGANIZED AND LINEAR IN
NATURE BY LATE AFTERNOON AND EARLY EVENING AS THEY PUSH THROUGH
THE METRO AREA. BY CONTRAST...OTHER MODELS...SUCH AS THE
HRRR...KEEP MUCH OF THE ACTIVITY OVER FAR NORTH GEORGIA OR THE FAR
SE PORTIONS OF THE STATE...LEAVING THE METRO AREA LARGELY UNSCATHED.
FOR NOW...HAVE LEANED MORE TOWARDS THE THINKING OF SPC...WITH
ISOLATED STORMS EXPECTED THROUGH THE AFTERNOON AND INTO TONIGHT. THIS
THINKING IS MORE PARALLEL WITH THE LOCAL WRF SOLUTION. COULD SEE
SOME CONVECTIVE INITIATION AS EARLY AS 12-1PM...BUT EXPECTING
ACTIVITY TO REALLY FIRE 2-3PM AND AFTER.
AGAIN...THIS IS A DIFFICULT FORECAST...AND UPDATES WILL LIKELY BE
NECESSARY THROUGH THE DAY.
31
&&
.PREV DISCUSSION... /ISSUED 735 AM EDT FRI AUG 17 2012/
SHORT TERM /TODAY THROUGH SATURDAY/...
/ISSUED AT 401 AM EDT FRI AUG 17 2012/
THE CONVECTIVE REMNANTS OF AN MCS IS PUSHING ACROSS NORTH AL AND NW
GA EARLY THIS MORNING. EXPECT CURRENT WEAKENING TREND TO CONTINUE...
SPREADING MAINLY MID LEVEL CLOUDINESS AND SPOTTY LIGHT RAIN INTO THE
ATLANTA METRO AREA BY MID TO LATE MORNING. ALTHO CANNOT RULE OUT A
FEW RUMBLES OF THUNDER THIS MORNING... EXPECT SPOTTY LIGHT RAIN TO
BE THE MAIN PRECIP TYPE IN ATLANTA THIS MORNING.
THE GREATER CONCERN IS AN APPROACHING COLD FRONT THAT IS EXPECTED
TO PUSH INTO NORTH GEORGIA LATER THIS AFTERNOON. GFS AND NAM SHOW
A SERIES OF STRONG UPPER VORT MAXES TRAVERSING NORTH GEORGIA
DURING DAYTIME HEATING. THIS COUPLED WITH THE FRONT SHOULD RESULT
IN WIDESPREAD SHOWERS AND THUNDERSTORMS PUSHING INTO NORTH GEORGIA
TODAY...WITH SCATTERED CONVECTION POSSIBLY SPREADING INTO PARTS
OF CENTRAL GEORGIA AS WELL. RESIDUAL CLOUD COVER FROM THIS
MORNINGS DISSIPATING MCS SHOULD HELP HOLD TEMPERATURES AND
INSTABILITIES DOWN A BIT TODAY. HOWEVER...TIMING OF THE UPPER
VORT MAX DURING MAX HEATING...ALONG WITH FRONTAL FORCING...ALL
SUGGEST THE POTENTIAL FOR ISOLATED STRONG TO SEVERE STORMS ACROSS
PARTS OF NORTH GEORGIA LATER THIS AFTERNOON AND EARLY EVENING. SPC
CONTINUES TO PLACE MUCH OF NORTH GEORGIA IN A SLIGHT RISK AREA
TODAY...GENERALLY ALONG AND NORTH OF A LAGRANGE TO COVINGTON TO
ATHENS LINE. THE MAIN STORM THREATS WILL BE DAMAGING WIND AND
MARGINAL SIZED HAIL. LOCALLY HEAVY RAIN IS ALSO A CONCERN WITH
TRAINING CELLS AHEAD OF THE FRONT. THE UPPER DISTURBANCES PUSH
EAST BY MIDNIGHT...SO EXPECT THE ASSOCIATED CONVECTION AHEAD OF
THE FRONT TO GREATLY DIMINISH BY THEN...ESPECIALLY WITH LOSS OF
DAYTIME HEATING.
THE FRONT STALLS ACROSS CENTRAL GEORGIA ON SATURDAY...SO WILL
SHOW THE GREATER RAIN CHANCES THERE SATURDAY AFTERNOON. MARGINAL
INSTABILITIES AND LACK OF UPPER SUPPORT SHOULD HELP HOLD STORM
DEVELOPMENT BELOW SEVERE LIMITS ON SATURDAY.
OTHERWISE...STARTED WITH A MAV AND MET BLEND FOR TEMPS THROUGH THE
SHORT TERM...THEN LEANED TOWARD THE COOLER MET HIGHS FOR TODAY
WITH RESIDUAL CLOUDINESS...THEN WARMER MAV HIGHS ON SATURDAY WITH
LESS CLOUDS AND ONLY ISOLATED TO SCATTERED CONVECTION EXPECTED.
39
LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
/ISSUED AT 401 AM EDT FRI AUG 17 2012/
CWA REMAINS IN LONGWAVE TROUGH AT THE BEGINNING OF THE LONG TERM.
MEANWHILE AT THE SFC...FRONT THAT MOVES THROUGH IN THE SHORT TERM
REMAINS SITUATED ACROSS THE SOUTHERN HALF OF THE STATE. THIS
PATTERN WILL DOMINATE THE LONG TERM. WITH FRONT MEANDERING AROUND
CENTRAL GEORGIA...BEST CHANCES OF RAIN THROUGH THE LONG TERM WILL
REMAIN ACROSS THE SOUTHERN HALF OF THE CWA. IN ADDITION WILL SEE
WEAK DISTURBANCES MOVE ALONG THE FRONT AS IT REMAINS STATIONARY.
GFS SHOWS THE BEST VORT MAX TO MOVE ALONG THE FRONT ON MONDAY AND
THIS WILL HELP TO REINFORCE CHANCE OF POPS. INITIALLY OVER THE
WEEKEND...POPS ARE ON THE LOWER SIDE OF GUIDANCE AS IT APPEARS MAV
IS OVER DOING POPS...WHEREAS LATER IN THE LONG TERM...POPS ARE
CLOSER TO GUIDANCE.
11
AVIATION...
12Z UPDATE...
TIMING TOOL AND HRRR MODEL INDICATES MID LEVEL CLOUDS AND SPOTTY
-SHRA MAY SPREAD INTO ATLANTA AREA FROM AL LATER THIS MORNING. WILL
SHOW BKN050 AND VCSH AT 16Z. THE GREATER CONVECTIVE THREAT WILL
BEGIN AT ATL AROUND 18Z AND CONTINUE THROUGH THE AFTERNOON- EARLY
EVENING HOURS WHEN A COLD FRONT PUSHES INTO FAR NORTH GA. EXPECT
CONVECTION TO GREATLY DIMINISH BY 04-06Z TONIGHT AS THE DRIVING
UPPER SHORT WAVE PUSHES EAST. WET GROUNDS SUGGEST POTENTIAL FOR IFR
CIGS BY 09-10Z SAT MORNING. EXPECT MAINLY WEST WINDS AROUND 8-10 KTS
BY MID-LATE MORNING...THEN WNW AT 5-7KTS LATER TONIGHT AS THE FRONT
DRAWS NEARER. ISOLATED SHOWERS MAY LINGER OVERNIGHT...BUT EXPECT THE
GREATER TSTM THREAT TO BE JUST SOUTH OF ATL ON SATURDAY.
//ATL CONFIDENCE...12Z UPDATE...
HIGH CONFIDENCE ALL ELEMENTS EXCEPT MEDIUM ON TIMING AND LOCATION OF
CONVECTION TODAY.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 87 69 89 67 / 80 40 30 20
ATLANTA 86 70 86 69 / 80 40 30 20
BLAIRSVILLE 80 66 81 62 / 80 50 20 10
CARTERSVILLE 86 69 85 64 / 90 50 20 20
COLUMBUS 91 72 89 70 / 80 40 30 20
GAINESVILLE 86 70 86 67 / 80 50 30 20
MACON 92 71 91 71 / 80 30 40 30
ROME 87 69 88 63 / 90 50 20 10
PEACHTREE CITY 87 69 86 66 / 80 40 30 20
VIDALIA 93 73 91 73 / 50 30 40 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...31
LONG TERM....BAKER
AVIATION...31
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1035 AM CDT FRI AUG 17 2012
.DISCUSSION...
ISSUED 1029 AM CDT FRI AUG 17 2012
ONLY MINOR CHANGES TO GRIDS THIS MORNING.
HIGH PRESSURE OVER THE CENTRAL PLAINS CONTINUES TO BUILD INTO
ILLINOIS IN THE WAKE OF YESTERDAYS COLD FRONT. SCATTERED CU WILL
DEVELOP WITH COOL TEMPS AT MID-LEVELS AND RESIDUAL MOISTURE FROM
YESTERDAYS CONVECTION. OTHERWISE...CURRENT FORECAST IN THE MIDDLE
70S TO NEAR 80 FAR SOUTHEAST LOOKS REASONABLE BASED ON LATEST LAMP
AND THIS MORNINGS KILX SOUNDING.
BARKER
&&
.AVIATION...
ISSUED 633 AM CDT FRI AUG 17 2012
LATEST IR SATELLITE LOOP SHOWS THE WESTERN EDGE OF CLOUD BAND
SOUTH OF I-70 AT DAYBREAK. HIGH PRESSURE IN THE CENTRAL PLAINS
WILL DRIFT TOWARD THE MID MISSISSIPPI VALLEY AND BE IN CONTROL OF
OUR WEATHER THROUGH THE WEEKEND. THE RESULT WILL BE VFR CONDITIONS
AND GENERALLY LIGHT WINDS.
COULD SEE SOME SCT CUMULUS DEVELOP LATE THIS MORNING DUE TO
HEATING AND RESIDUAL LOW LEVEL MOISTURE. THE OOZ NAM SOUNDINGS IN
BUFKIT AND THE 08Z HRRR CLOUD BASE HEIGHT FORECASTS BOTH SHOW THE
LIKELIHOOD OF SCT LOW LEVEL CLOUDS AROUND 5000 FT FROM 16Z TIL
22Z TODAY.
MILLER
&&
.PREV DISCUSSION...
ISSUED 330 AM CDT FRI AUG 17 2012
SHORT TERM...TODAY THROUGH MONDAY NIGHT
00Z MODELS ARE IN FAIR AGREEMENT WITH SYNOPTICS AND GENERALLY
FAVOR QUIET WEATHER DURING THIS NEXT WEEK WITH BELOW NORMAL TEMPS
THIS WEEKEND GRADUALLY WARMING BACK UP DURING MIDDLE AND LATER
PART OF NEXT WEEK. USED A BLEND OF THE WARM MET AND COOLER MAV
HIGHS THROUGH MONDAY WHILE LEANING ON COOLER MET GUIDANCE FOR LOWS
NEXT FEW NIGHTS.
STRONG COLD FRONT HAS PUSHED SE OF IL EARLY THIS MORNING AND
APPROACHING THE OHIO RIVER WITH CLEARING SKIES SPREADING SE TO A
CHAMPAIGN TO TAYLORVILLE LINE. SOME PATCHY FOG FROM
CHARLESTON/MATTOON SE TO LAWRENCEVILLE WITH MATTOON AIRPORT VSBY
LOWEST AT 3/4 MILE. PATCHY FOG SHOULD LIFT BY MID MORNING IN SE IL
WHILE CLOUDS DECREASE. SCATTERED CUMULUS CLOUDS TO DEVELOP BY LATE
MORNING INTO THE AFTERNOON ESPECIALLY OVER EASTERN IL WHERE PARTLY
TO MOSTLY SUNNY SKIES EXPECTED. HIGHS IN THE MID TO UPPER 70S WITH
LAWRENCEVILLE NEAR 80F. 1022 MB HIGH PRESSURE OVER SD/NE TO SETTLE
INTO IL SAT AND CONTINUE A FAIR AMOUNT OF SUNSHINE WITH HIGHS IN
THE UPPER 70S WITH SW AREAS NEAR 80F. STRONG UPPER LEVEL TROF
DIGGING SOUTHWARD FROM JAMES BAY INTO THE EASTERN STATES THIS
WEEKEND TO KEEP TEMPS A BIT BELOW NORMAL THROUGH MONDAY. SOME
MODELS SHOW WEAK SHORT WAVES IN NW FLOW MOVING NEAR IL SAT NIGHT
AND SUNDAY BUT LIMITED MOISTURE TO WORK WITH AND WILL KEEP A DRY
FORECAST WITH POPS ONLY 10%.
LONG TERM...TUESDAY THROUGH FRIDAY
STRONG UPPER LEVEL TROF TO GRADUALLY PULL AWAY FROM IL DURING
MIDDLE OF NEXT WEEK AS UPPER LEVEL RIDGE IN THE WEST SHIFTS EASTWARD
AND NOSES CLOSER TO IL LATER NEXT WORK WEEK. THIS TO GRADUALLY
WARM TEMPS BACK UP INTO THE MID TO UPPER 80S WITH SW AREAS AROUND 90F
LATER NEXT WEEK. GENERALLY DRY CONDITIONS EXPECTED TO CONTINUE
WITH TROPICAL MOISTURE STAYING SE OF IL AND WEATHER DISTURBANCES
PASSING NORTH AND WEST OF IL THROUGH NEXT FRIDAY. GFS SEEMS TOO
QUICK WITH BRINGING A COLD FRONT SE INTO IL LATER NEXT WEEK AND
LEANED TOWARD THE SLOWER ECMWF MODEL.
KH
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
633 AM CDT FRI AUG 17 2012
.DISCUSSION...
ISSUED 330 AM CDT FRI AUG 17 2012
SHORT TERM...TODAY THROUGH MONDAY NIGHT
00Z MODELS ARE IN FAIR AGREEMENT WITH SYNOPTICS AND GENERALLY
FAVOR QUIET WEATHER DURING THIS NEXT WEEK WITH BELOW NORMAL TEMPS
THIS WEEKEND GRADUALLY WARMING BACK UP DURING MIDDLE AND LATER
PART OF NEXT WEEK. USED A BLEND OF THE WARM MET AND COOLER MAV
HIGHS THROUGH MONDAY WHILE LEANING ON COOLER MET GUIDANCE FOR LOWS
NEXT FEW NIGHTS.
STRONG COLD FRONT HAS PUSHED SE OF IL EARLY THIS MORNING AND
APPROACHING THE OHIO RIVER WITH CLEARING SKIES SPREADING SE TO A
CHAMPAIGN TO TAYLORVILLE LINE. SOME PATCHY FOG FROM
CHARLESTON/MATTOON SE TO LAWRENCEVILLE WITH MATTOON AIRPORT VSBY
LOWEST AT 3/4 MILE. PATCHY FOG SHOULD LIFT BY MID MORNING IN SE IL
WHILE CLOUDS DECREASE. SCATTERED CUMULUS CLOUDS TO DEVELOP BY LATE
MORNING INTO THE AFTERNOON ESPECIALLY OVER EASTERN IL WHERE PARTLY
TO MOSTLY SUNNY SKIES EXPECTED. HIGHS IN THE MID TO UPPER 70S WITH
LAWRENCEVILLE NEAR 80F. 1022 MB HIGH PRESSURE OVER SD/NE TO SETTLE
INTO IL SAT AND CONTINUE A FAIR AMOUNT OF SUNSHINE WITH HIGHS IN
THE UPPER 70S WITH SW AREAS NEAR 80F. STRONG UPPER LEVEL TROF
DIGGING SOUTHWARD FROM JAMES BAY INTO THE EASTERN STATES THIS
WEEKEND TO KEEP TEMPS A BIT BELOW NORMAL THROUGH MONDAY. SOME
MODELS SHOW WEAK SHORT WAVES IN NW FLOW MOVING NEAR IL SAT NIGHT
AND SUNDAY BUT LIMITED MOISTURE TO WORK WITH AND WILL KEEP A DRY
FORECAST WITH POPS ONLY 10%.
LONG TERM...TUESDAY THROUGH FRIDAY
STRONG UPPER LEVEL TROF TO GRADUALLY PULL AWAY FROM IL DURING
MIDDLE OF NEXT WEEK AS UPPER LEVEL RIDGE IN THE WEST SHIFTS EASTWARD
AND NOSES CLOSER TO IL LATER NEXT WORK WEEK. THIS TO GRADUALLY
WARM TEMPS BACK UP INTO THE MID TO UPPER 80S WITH SW AREAS AROUND 90F
LATER NEXT WEEK. GENERALLY DRY CONDITIONS EXPECTED TO CONTINUE
WITH TROPICAL MOISTURE STAYING SE OF IL AND WEATHER DISTURBANCES
PASSING NORTH AND WEST OF IL THROUGH NEXT FRIDAY. GFS SEEMS TOO
QUICK WITH BRINGING A COLD FRONT SE INTO IL LATER NEXT WEEK AND
LEANED TOWARD THE SLOWER ECMWF MODEL.
KH
&&
.AVIATION...
ISSUED 633 AM CDT FRI AUG 17 2012
LATEST IR SATELLITE LOOP SHOWS THE WESTERN EDGE OF CLOUD BAND
SOUTH OF I-70 AT DAYBREAK. HIGH PRESSURE IN THE CENTRAL PLAINS
WILL DRIFT TOWARD THE MID MISSISSIPPI VALLEY AND BE IN CONTROL OF
OUR WEATHER THROUGH THE WEEKEND. THE RESULT WILL BE VFR CONDITIONS
AND GENERALLY LIGHT WINDS.
COULD SEE SOME SCT CUMULUS DEVELOP LATE THIS MORNING DUE TO
HEATING AND RESIDUAL LOW LEVEL MOISTURE. THE OOZ NAM SOUNDINGS IN
BUFKIT AND THE 08Z HRRR CLOUD BASE HEIGHT FORECASTS BOTH SHOW THE
LIKELIHOOD OF SCT LOW LEVEL CLOUDS AROUND 5000 FT FROM 16Z TIL
22Z TODAY.
MILLER
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON KY
953 AM EDT FRI AUG 17 2012
.UPDATE...
ISSUED AT 953 AM EDT FRI AUG 17 2012
HAVE UPDATED NDFD AND ZFP BASED ON LATEST OBSERVATIONAL TRENDS.
EXTENSIVE CLOUDINESS WILL LIMIT DESTABILIZATION AND OVERALL
THUNDERSTORM CHANCES TODAY...BUT STILL EXPECT NUMEROUS TO WIDESPREAD
SHOWERS. BEST CHANCE FOR STRONGER THUNDERSTORMS WILL BE OVER THE
SOUTHEAST PART OF THE FORECAST AREA. 10Z HRRR IS SHOWING CONVECTION
DEVELOPING FROM MONTICELLO TO PAINTSVILLE THIS AFTERNOON AND THEN
MOVING SOUTHEAST.
UPDATE ISSUED AT 659 AM EDT FRI AUG 17 2012
UPDATED FOR CURRENT CONDITIONS/OBSERVED TRENDS. WITH LACK OF RETURNS
ON RADAR AND SLOWER PRECIP DEVELOPMENT IN 06Z RUNS...THIS INCLUDES
LATER DEVELOPMENT OF PRECIP THIS MORNING.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 352 AM EDT FRI AUG 17 2012
A COLD FRONT WILL APPROACH FROM THE NW TODAY...AND TRANSITION ACROSS
THE REGION TONIGHT. EXTENSIVE CLOUD COVER WILL LIMIT
DESTABILIZATION. HOWEVER...THE RIGHT ENTRANCE REGION OF AN UPPER JET
COINCIDING WITH THE FRONT WILL AID IN SUPPORT FOR PRECIP. WILL CALL
FOR 70-80 PERCENT POPS...BUT ONLY A CHANCE FOR THUNDER.
AS DRIER AIR ARRIVES FROM NW TO SE THIS AFTERNOON AND TONIGHT...
PRECIP WILL TAPER OFF AND CLOUDS WILL DECREASE. THIS WILL LEAVE A DRY
DAY ON SATURDAY...WITH SURFACE HIGH PRESSURE TO OUR NW BEING OUR
DOMINANT FEATURE.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 352 AM EDT FRI AUG 17 2012
MODELS REMAIN IN FAIRLY GOOD AGREEMENT THROUGH THE BEGINNING OF NEXT
WEEK DEPICTING ANOTHER LOW MOVING INTO HUDSON BAY BEFORE UNDERGOING
AN AMPLIFICATION OF THE TROF OVER THE ERN CONUS...WITH NUMEROUS
SHORT WAVES RIPPLING AROUND THE BACKSIDE OF THE LOW TRANSITING THE
OHIO VALLEY FROM LATE THIS WEEKEND INTO EARLY NEXT WEEK. AT THE
SFC...GUIDANCE POINTS TOWARDS HIGH PRESSURE OVER THE PLAINS EARLY IN
THE PERIOD SLIDING EAST INTO THE REGION AND LINGERING OVER THE AREA
THROUGH ABOUT THE MIDDLE OF NEXT WEEK BEFORE SHIFTING FURTHER EAST
AND ULTIMATELY OPENING UP A RETURN FLOW OF WARMER...MOIST GOMEX AIR
LATE IN THE PERIOD.
THE 17.00Z ECMWF BRINGS ONE OF THESE WAVES THROUGH THE AREA ON
SUNDAY NIGHT INTO MONDAY WHILE THE CONSENSUS SUGGESTS QUITE A BIT OF
DEEP MOISTURE IN PLACE OVER THE AREA...AND HAVE INCLUDED A SLIGHT
CHANCE FOR THE SE AND HIGHER TERRAIN ALONG THE KY/VA LINE THROUGH
THIS TIME FRAME. THE NERN CONUS TROF BEGINS TO LIFT OFF TO THE NE BY
MID WEEK...SOMEWHAT FASTER IN THE LATEST GFS SOLUTION...WHILE THE
EURO DEVELOPS A CLOSED LOW OVER THE CONFLUENCE OF THE MS/OH RIVERS.
HAVE SPLIT THE DIFFERENCE HERE AND INTRODUCED ANOTHER ROUND OF
SLIGHT CHANCE POPS TO ROUND OUT THE LONG TERM.
TEMPS THROUGH THE PERIOD STILL LOOK TO START OUT BELOW NORMAL BEFORE
MODERATING AROUND THE MIDDLE OF NEXT WEEK TO NEAR AND ABOVE NORMAL
BY THE END OF THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 659 AM EDT FRI AUG 17 2012
A FEW LIGHT SHOWERS WERE IN THE AREA EARLY THIS MORNING. ADDITIONAL
SHOWERS ARE EXPECTED TO DEVELOP DURING THE DAY...WITH MOST LOCATIONS
ENDING UP WET. THERE MAY ALSO BE THUNDERSTORMS...BUT CONFIDENCE IN
WHEN AND WHERE IS TOO LOW TO ALLOW ADDRESSING IT IN TAFS. LOCALIZED
MVFR AND IFR IS POSSIBLE IN PRECIP DURING THE DAY...BUT PREVAILING
WEATHER SHOULD BE VFR. PRECIP SHOULD END FROM NW TO SE DURING THE
AFTERNOON AND EVENING.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SBH
SHORT TERM...HAL
LONG TERM....MB
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1131 AM EDT FRI AUG 17 2012
.SYNOPSIS...
A COLD FRONT WILL CROSS THE UPPER OHIO VALLEY TODAY ACCOMPANIED BY
SOME SHOWERS AND THUNDERSTORMS. COOLER AND DRIER WEATHER WILL
FOLLOW FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH 8 PM THIS EVENING/...
AN UPDATE HAS BEEN ISSUED TO ACCOUNT FOR THE LATEST RADAR AND TEMP
TRENDS AS A COLD FRONT CROSSES THE AREA.
THE LATEST SURFACE ANALYSIS INDICATES A COLD FRONT EXTENDING ALONG
A NEW MARTINSVILLE-WAYNESBURG-LATROBE LINE. THE FRONT IS MOST
INDICATIVE BY WINDS SHIFTING TO WESTERLY AND BY IR/WV SAT
IMAGERY. ASIDE FROM THE WIND SHIFT, THE TEMP AND TD GRADIENTS ARE
WEAK ALONG THE FRONT WITH A MORE GRADUAL DECREASE IN TDS UPSTREAM.
SHOWERS ARE MOSTLY ALONG AND BEHIND THE FRONT.
THIS AFTERNOON...THE FRONT WILL CONTINUE TO MOVE EASTWARD TO THE
RIDGES, SLOWING AS IT CROSSES THEM. WITH THE FRONT, SCATTERED TO
NUMEROUS SHOWERS CAN BE EXPECTED FOR A FEW HOURS INTO THE EARLY
AFTERNOON BEFORE COMING TO AN END. THE STORM PREDICTION CENTER HAS A
PORTION OF THE SOUTHEAST RIDGES HIGHLIGHTED IN ITS MOST RECENT DAY 1
OUTLOOK. DESPITE THE RAP INDICATING AROUND 1000 J/KG SBCAPE AND
40KTS 0-6KM SHEAR, BELIEVE CLOUD COVERAGE AND WEAK FORCING WILL BE
INHIBITORS TO THE DEVELOPMENT OF SEVERE THIS AFTERNOON. A FEW
THUNDERSTORMS CANNOT BE RULED OUT. QPF WILL GENERALLY BE LESS
THAN A QUARTER OF AN INCH ACROSS THE AREA WITH THE HIGHEST AMOUNTS
ALONG THE SOUTHEAST RIDGES.
TEMP FORECAST IS CHALLENGING TODAY AS WEAK COLD AIR ADVECTION
BATTLES SUNSHINE BEHIND THE FRONT. FORECAST CONSISTS OF A
HRRR/LAMP BLEND WITH TEMPS ADJUSTED DOWN ALONG RAIN-COOLED PRECIP
AREA ALONG THE FRONT. AFTER THE FRONT PUSHES EAST, TEMPS WILL
WARM INTO THE MID 70S ACROSS MUCH OF THE AREA LATE THIS AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY/...
THE FRONT IS PROJECTED SOUTH OF THE AREA BY THIS EVENING AND POPS
HAVE BEEN TAPERED OFF. COOL AND DRY SURFACE HIGH PRES...UNDER A
BROAD TROUGH ALOFT...WILL SUPPORT TEMPS OF 5 TO 10 DEGREES BELOW
NORMAL...AND A DRY WEEKEND FOR MOST COUNTIES. THE EXCEPTION MAY BE
OVER THE RIDGES WHERE A CROSSING DISTURBANCE AND UPSLOPE FLOW ON
SUNDAY MAY SUPPORT SOME ISOLATED SHOWERS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
KEPT MENTION OF ISOLATED SHOWERS ALONG THE RIDGES SUNDAY NIGHT INTO
MONDAY AS AN UPPER TROUGH REMAINS OVER THE GREAT LAKES REGION WHILE
A WEAK SURFACE LOW CROSSES THE SOUTHEASTERN STATES. THE REMAINDER OF
THE EXTENDED PERIOD SHOULD BE DRY AS A SURFACE RIDGE BUILDS EASTWARD
ACROSS THE UPPER OHIO VALLEY.
TEMPERATURES ARE FORECAST TO BE 5 TO 10 DEGREES BELOW NORMAL THROUGH
TUESDAY...THEN RETURN TO NEAR NORMAL BY MIDWEEK.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
COLD FRONT INTO EASTERN OHIO AT 12Z WITH ONLY SCATTERED SHOWERS
ALONG AND BEHIND FRONT. STILL EXPECT MORE DEVELOPMENT LATER TODAY
ALONG FRONT WITH HIGHEST POPS TOWARD THE I-80 CORRIDOR AND THE
SOUTHEAST RIDGES. FOR THE TERMINALS THIS BRINGS A PERIOD OF MVFR
TODAY WITH THE FRONT. WINDS WILL SHIFT TO THE NORTHWEST THIS
AFTERNOON NEAR 10KTS. TONIGHT FRONT WILL EXIT SOUTHEAST WITH DRY
HIGH PRESSURE BRINING GENERAL VFR.
.OUTLOOK/ SATURDAY THROUGH TUESDAY/... GENERALLY VFR WEATHER IS
ANTICIPATED UNDER A WEAK SURFACE RIDGE...WITH NO WIDESPREAD
PRECIPITATION OR RESTRICTIONS ANTICIPATED.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1139 AM EDT FRI AUG 17 2012
.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO MOVE ACROSS NEW YORK THIS AFTERNOON.
FOLLOWING THE FRONT EXPECT COOLER TEMPERATURES AND LESS HUMID
CONDITIONS FOR THIS AFTERNOON AND THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE COLD FRONT HAS CROSSED PRETTY MUCH ALL OF THE CWA WITH SOME
LINGERING SHOWERS ACROSS THE SOUTHEAST SECTIONS.
WITH COOLER AIR MOVING IN BEHIND THE FRONT...AND THE RELATIVELY
WARM LAKES...EXPECT ANY BRIEF CLEARING WILL LIKELY FILL IN WITH
LAKE-AIDED STRATOCUMULUS THIS AFTERNOON. THE HRRR HAS CONSISTENTLY
DEVELOPED SHOWERS AS A SW FLOW OFF LAKE ERIE CONVERGES WITH A MORE
WNW FLOW. FEEL THIS IS A REAL POSSIBILITY...SO WILL CARRY A CHANCE
FOR SHOWERS CENTERED IN THE NORTHTOWNS WHERE THIS CONVERGENCE
TYPICALLY OCCURS.
OTHERWISE...HIGH PRESSURE WILL BUILD ACROSS THE REGION FROM THE WEST
TONIGHT. THIS SHOULD RESULT IN A GENERAL DRYING TREND...WHERE
LINGERING CLOUDS FROM THE DAY SHOULD DISSIPATE. THIS SAID...A MORE
WESTERLY FLOW ON LAKE ONTARIO MAY ALLOW FOR LAKE CONVERGENCE CLOUDS
TO DEVELOP AND MOVE EAST OF LAKE ONTARIO LATE TONIGHT. THERE SHOULD
BE AMPLE PERIODS OF CLEARING TO ALLOW FOR TEMPERATURES TO COOL
CONSIDERABLY TONIGHT. LOWS WILL LIKELY RANGE FROM THE MID AND UPPER
40S IN THE COOL VALLEYS OF THE SOUTHERN TIER AND EAST OF LAKE ONTARIO...TO
THE LOWER 50S ELSEWHERE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
DURING THE WEEKEND...OUR REGION WILL REMAIN UNDER THE INFLUENCE OF
DEEP UPPER TROUGHING CENTERED NEAR JAMES BAY...WHILE SURFACE BASED
RIDGING OVER THE OHIO VALLEY AND LOWER LAKES GRADUALLY EXPANDS
NORTHEASTWARD INTO NEW ENGLAND.
UNDER THIS PATTERN...COOLER AND MAINLY DRY WEATHER WILL BE
PREDOMINANT. WHILE TEMPS ALOFT WILL BE CERTAINLY COOL ENOUGH FOR A
LAKE RESPONSE...THE RELATIVELY DRY NATURE OF OUR AIRMASS AND A FAIR
AMOUNT OF LOW LEVEL SHEAR SHOULD PREVENT MUCH MORE THAN SOME
LAKE-DRIVEN STRATOCU DOWNWIND OF THE LAKES EARLY SATURDAY
MORNING...AND AGAIN LATER SATURDAY NIGHT INTO EARLY SUNDAY.
SYNOPTICALLY...THE NAM/GFS/ECMWF ALL TRY TO SPIT OUT SOME SPOTTY
LIGHT SHOWERS ACROSS PARTS OF THE AREA SUNDAY AFTERNOON WITH DAYTIME
HEATING AND THE APPROACH OF A MODEST SHORTWAVE...BUT THIS STILL
APPEARS TO BE WORTHY OF NO MORE THAN SOME SLIGHT CHANCE POPS GIVEN
ONLY VERY LIMITED AMOUNTS OF AVAILABLE MOISTURE.
IN TERMS OF ACTUAL TEMPERATURES...850 MB READINGS WILL AVERAGE IN
THE +7C TO +9C RANGE SATURDAY...AND A DEGREE OR SO WARMER THAN THAT
ON SUNDAY. THIS WILL TRANSLATE INTO COMFORTABLE HIGHS IN THE LOWER
70S ON SATURDAY...AND THE LOWER TO MID 70S ON SUNDAY. MEANWHILE...
NIGHTTIME LOWS SATURDAY NIGHT WILL RANGE FROM THE MID 40S ACROSS
INTERIOR SECTIONS OF THE SOUTHERN TIER AND NORTH COUNTRY TO THE
LOWER 50S ALONG THE LAKE PLAINS...BEFORE MODERATING A FEW DEGREES
FOR SUNDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
THE COOL WEATHER OF THE SHORT TERM PERIOD WILL PERSIST INTO THE
FIRST COUPLE DAYS OF THE EXTENDED RANGE AS WELL...AS THE LARGE-SCALE
UPPER TROUGH REMAINS IN PLACE ACROSS THE GREAT LAKES AND NORTHEAST.
WITH DAYTIME HEATING OF THE STILL-COOL AIRMASS ALOFT...THE PASSAGE
OF A VERY WEAK SURFACE TROUGH COULD SET OFF SOME ISOLATED SHOWER AND
THUNDERSTORM ACTIVITY ON MONDAY...WITH THE APPROACH AND PASSAGE OF
THE MAIN UPPER TROUGH AXIS POSSIBLY DOING THE SAME ON TUESDAY. WILL
ACCORDINGLY KEEP SLIGHT CHANCE POPS IN PLACE FOR BOTH DAYS...WITH
ANY PRECIP THAT DOES FORM DIMINISHING WITH THE LOSS OF HEATING BOTH
MONDAY AND TUESDAY EVENINGS. 850 MB TEMPS LINGERING IN THE +8C TO
+10C RANGE WILL SUPPORT HIGHS IN THE LOWER TO MID 70S BOTH
DAYS...WITH NIGHTTIME LOWS IN THE 50S EXPECTED BOTH NIGHTS.
AFTER THAT...THE GFS AND ECMWF REMAIN IN GOOD AGREEMENT ON THE CORE
OF THE UPPER TROUGH LIFTING OFF INTO LABRADOR AND THEN INTO THE
NORTHERN ATLANTIC...WITH A RELATIVELY FLAT ZONAL FLOW SETTING UP
ACROSS THE LOWER LAKES AND NORTHEAST IN ITS WAKE. THE ENSUING WARM
AIR ADVECTION PATTERN WILL RESULT IN A GRADUAL WARMING TREND THROUGH
THE PERIOD...WITH DAYTIME HIGHS RECOVERING TO NEAR THE 80 DEGREE
MARK BY THURSDAY...AND NIGHTTIME LOWS ALSO MODERATING A FEW DEGREES
EACH NIGHT. AS FOR PRECIP CHANCES...THESE LOOK TO BE PRACTICALLY NIL
ON WEDNESDAY WITH THE DEPARTURE OF THE TROUGH AND LOW-LEVEL RIDGING
REMAINING IN PLACE...BEFORE CLIMBING BACK INTO THE SLIGHT CHANCE
RANGE ON THURSDAY WITH THE APPROACH OF ANOTHER WEAK SURFACE TROUGH.
&&
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
THE COLD FRONT HAS MOVED THROUGH ALL OF THE TAF SITES AND
CONTINUES TO MOVE TO THE EAST OF THE CWA. VFR CONDS BEHIND THE
FRONT WILL LOWER TO MVFR AS A FAIR AMOUNT OF CU DEVELOPS IN THE
SELF-DESTRUCTIVE SUNSHINE. THERE MAY BE A STRAY SHOWERS IN THE
VICINITY OF BUF THIS AFTERNOON DUE TO THE CONVERGENCE OF A SW FLOW
UP LAKE ERIE AND A WNW FLOW ELSEWHERE.
CLOUDS SHOULD SLOWLY SCATTER OUT TONIGHT AS WINDS OFF THE LAKES
DIMINISH...AND DRIER AIR MOVES IN. THERE COULD BE SOME FOG IN
JHW...OTHERWISE EXPECT VFR CONDITIONS TONIGHT.
OUTLOOK...
SATURDAY...POSSIBLE MVFR/IFR IN FOG EARLY OTHERWISE VFR.
SUNDAY...VFR.
MONDAY...CHANCE OF SHOWERS/TSTMS. MAINLY VFR.
TUESDAY AND WEDNESDAY...VFR.
&&
.MARINE...
THE COLD FRONT HAS CROSSED THE LAKES WITH A WEST TO NORTHWEST FLOW
ESTABLISHING ITSELF ACROSS THE LAKES.
THE BRISK FLOW WILL PRODUCE WAVES INCREASING TO 5 FT ACROSS THE
EASTERN LAKE ONTARIO REGION. SMALL CRAFT ADVISORIES HAVE BEEN
POSTED THROUGH THE EARLY OVERNIGHT FOR THESE AREAS.
AS THE SURFACE HIGH BUILDS ACROSS THE REGION OVERNIGHT AND
SATURDAY WINDS WILL DIMINISH.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR LEZ040-
041.
SMALL CRAFT ADVISORY UNTIL 2 AM EDT SATURDAY FOR
LOZ044-045.
&&
$$
SYNOPSIS...APFFEL/LEVAN
NEAR TERM...APFFEL/LEVAN
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...APFFEL/LEVAN
MARINE...APFFEL/LEVAN
AREA FORECAST DISCUSSION
NWS BUFFALO NY
942 AM EDT FRI AUG 17 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE REGION THROUGH THIS MORNING
PRODUCING A BAND OF SHOWERS AND POSSIBLY A THUNDERSTORM. FOLLOWING
THE PASSAGE OF THE COLD FRONT EXPECT COOLER TEMPERATURES AND LESS
HUMID CONDITIONS FOR THIS AFTERNOON AND THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE COLD FRONT CONTINUES TO MOVE ACROSS THE AREA THIS MORNING.
ACTIVITY ALONG THE FRONT IS CERTAINLY NOT AS HEAVY AS EARLIER THIS
MORNING WITH LITTLE THUNDER AT THIS TIME.
THE FRONT WILL EXIT TO THE EAST BY THIS AFTERNOON...WHICH WILL END
THE STEADY RAIN SHOWERS. HOWEVER...WITH COOLER AIR MOVING IN BEHIND
THE FRONT...AND THE RELATIVELY WARM LAKES...EXPECT ANY BRIEF
CLEARING WILL LIKELY FILL IN WITH LAKE-AIDED STRATOCUMULUS THIS
AFTERNOON. THE HRRR HAS CONSISTENTLY DEVELOPED SHOWERS AS A SW FLOW
OFF LAKE ERIE CONVERGES WITH A MORE WNW FLOW. FEEL THIS IS A REAL
POSSIBILITY...SO WILL CARRY A CHANCE FOR SHOWERS CENTERED IN THE
NORTHTOWNS WHERE THIS CONVERGENCE TYPICALLY OCCURS.
OTHERWISE...HIGH PRESSURE WILL BUILD ACROSS THE REGION FROM THE WEST
TONIGHT. THIS SHOULD RESULT IN A GENERAL DRYING TREND...WHERE
LINGERING CLOUDS FROM THE DAY SHOULD DISSIPATE. THIS SAID...A MORE
WESTERLY FLOW ON LAKE ONTARIO MAY ALLOW FOR LAKE CONVERGENCE CLOUDS
TO DEVELOP AND MOVE EAST OF LAKE ONTARIO LATE TONIGHT. THERE SHOULD
BE AMPLE PERIODS OF CLEARING TO ALLOW FOR TEMPERATURES TO COOL
CONSIDERABLY TONIGHT. LOWS WILL LIKELY RANGE FROM THE MID AND UPPER
40S IN THE COOL VALLEYS OF THE SOUTHERN TIER AND EAST OF LAKE ONTARIO...TO
THE LOWER 50S ELSEWHERE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
DURING THE WEEKEND...OUR REGION WILL REMAIN UNDER THE INFLUENCE OF
DEEP UPPER TROUGHING CENTERED NEAR JAMES BAY...WHILE SURFACE BASED
RIDGING OVER THE OHIO VALLEY AND LOWER LAKES GRADUALLY EXPANDS
NORTHEASTWARD INTO NEW ENGLAND.
UNDER THIS PATTERN...COOLER AND MAINLY DRY WEATHER WILL BE
PREDOMINANT. WHILE TEMPS ALOFT WILL BE CERTAINLY COOL ENOUGH FOR A
LAKE RESPONSE...THE RELATIVELY DRY NATURE OF OUR AIRMASS AND A FAIR
AMOUNT OF LOW LEVEL SHEAR SHOULD PREVENT MUCH MORE THAN SOME
LAKE-DRIVEN STRATOCU DOWNWIND OF THE LAKES EARLY SATURDAY
MORNING...AND AGAIN LATER SATURDAY NIGHT INTO EARLY SUNDAY.
SYNOPTICALLY...THE NAM/GFS/ECMWF ALL TRY TO SPIT OUT SOME SPOTTY
LIGHT SHOWERS ACROSS PARTS OF THE AREA SUNDAY AFTERNOON WITH DAYTIME
HEATING AND THE APPROACH OF A MODEST SHORTWAVE...BUT THIS STILL
APPEARS TO BE WORTHY OF NO MORE THAN SOME SLIGHT CHANCE POPS GIVEN
ONLY VERY LIMITED AMOUNTS OF AVAILABLE MOISTURE.
IN TERMS OF ACTUAL TEMPERATURES...850 MB READINGS WILL AVERAGE IN
THE +7C TO +9C RANGE SATURDAY...AND A DEGREE OR SO WARMER THAN THAT
ON SUNDAY. THIS WILL TRANSLATE INTO COMFORTABLE HIGHS IN THE LOWER
70S ON SATURDAY...AND THE LOWER TO MID 70S ON SUNDAY. MEANWHILE...
NIGHTTIME LOWS SATURDAY NIGHT WILL RANGE FROM THE MID 40S ACROSS
INTERIOR SECTIONS OF THE SOUTHERN TIER AND NORTH COUNTRY TO THE
LOWER 50S ALONG THE LAKE PLAINS...BEFORE MODERATING A FEW DEGREES
FOR SUNDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
THE COOL WEATHER OF THE SHORT TERM PERIOD WILL PERSIST INTO THE
FIRST COUPLE DAYS OF THE EXTENDED RANGE AS WELL...AS THE LARGE-SCALE
UPPER TROUGH REMAINS IN PLACE ACROSS THE GREAT LAKES AND NORTHEAST.
WITH DAYTIME HEATING OF THE STILL-COOL AIRMASS ALOFT...THE PASSAGE
OF A VERY WEAK SURFACE TROUGH COULD SET OFF SOME ISOLATED SHOWER AND
THUNDERSTORM ACTIVITY ON MONDAY...WITH THE APPROACH AND PASSAGE OF
THE MAIN UPPER TROUGH AXIS POSSIBLY DOING THE SAME ON TUESDAY. WILL
ACCORDINGLY KEEP SLIGHT CHANCE POPS IN PLACE FOR BOTH DAYS...WITH
ANY PRECIP THAT DOES FORM DIMINISHING WITH THE LOSS OF HEATING BOTH
MONDAY AND TUESDAY EVENINGS. 850 MB TEMPS LINGERING IN THE +8C TO
+10C RANGE WILL SUPPORT HIGHS IN THE LOWER TO MID 70S BOTH
DAYS...WITH NIGHTTIME LOWS IN THE 50S EXPECTED BOTH NIGHTS.
AFTER THAT...THE GFS AND ECMWF REMAIN IN GOOD AGREEMENT ON THE CORE
OF THE UPPER TROUGH LIFTING OFF INTO LABRADOR AND THEN INTO THE
NORTHERN ATLANTIC...WITH A RELATIVELY FLAT ZONAL FLOW SETTING UP
ACROSS THE LOWER LAKES AND NORTHEAST IN ITS WAKE. THE ENSUING WARM
AIR ADVECTION PATTERN WILL RESULT IN A GRADUAL WARMING TREND THROUGH
THE PERIOD...WITH DAYTIME HIGHS RECOVERING TO NEAR THE 80 DEGREE
MARK BY THURSDAY...AND NIGHTTIME LOWS ALSO MODERATING A FEW DEGREES
EACH NIGHT. AS FOR PRECIP CHANCES...THESE LOOK TO BE PRACTICALLY NIL
ON WEDNESDAY WITH THE DEPARTURE OF THE TROUGH AND LOW-LEVEL RIDGING
REMAINING IN PLACE...BEFORE CLIMBING BACK INTO THE SLIGHT CHANCE
RANGE ON THURSDAY WITH THE APPROACH OF ANOTHER WEAK SURFACE TROUGH.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
A COLD FRONT WHICH HAS JUST REACHED IAG/BUF/JHW THROUGH 12Z WILL
CONTINUE TO PUSH QUICKLY TO THE EAST. SHOWS WILL LINGER BRIEFLY
BEHIND THE BOUNDARY THIS MORNING...BUT SHOULD GIVE WAY TO FAIR
WEATHER. EVEN WITH THE SHOWERS...EXPECT MVFR/VFR CONDITIONS. THERE
IS STILL A CHANCE FOR THUNDERSTORMS...MAINLY AT ART WHICH IS STILL
AHEAD OF THE FRONT. THUNDERSTORMS MAY BRIEFLY DROP VSBY TO 2SM OR
LESS.
FOLLOWING THE PASSAGE OF THE COLD FRONT EXPECT THE VFR
LEVEL DECK TO TEMPORARILY SCATTER OUT THIS MORNING...ONLY TO FILL
BACK IN AGAIN WITH DAYTIME HEATING AS MOISTURE BECOMES TRAPPED
BENEATH THE SUBSIDENCE INVERSION. EXPECT MOST IF NOT ALL OF THIS
POST-FRONTAL CLOUD COVER TO BE VFR IN THE 035-050 KFT RANGE. THERE
MAY BE A STRAY SHOWERS IN THE VICINITY OF BUF THIS AFTERNOON DUE
TO THE CONVERGENCE OF A SW FLOW UP LAKE ERIE AND A WNW FLOW ELSEWHERE.
CLOUDS SHOULD SLOWLY SCATTER OUT TONIGHT AS WINDS OFF THE LAKES
DIMINISH...AND DRIER AIR MOVES IN. THERE COULD BE SOME FOG IN
JHW...OTHERWISE EXPECT VFR CONDITIONS TONIGHT.
OUTLOOK...
SATURDAY...POSSIBLE MVFR/IFR IN FOG EARLY OTHERWISE VFR.
SUNDAY...VFR.
MONDAY...CHANCE OF SHOWERS/TSTMS. MAINLY VFR.
TUESDAY...VFR.
&&
.MARINE...
A COLD FRONT WILL MOVE ACROSS THE WATERS FROM WEST TO EAST THIS
MORNING. WINDS WILL BRIEFLY BE BREEZY AHEAD OF THE FRONT...BUT THE
SSW WIND DIRECTION IS UNFAVORABLE FOR BUILDING WAVES ON LAKE
ONTARIO. DO HAVE SOME CONCERN ON LAKE ERIE...WHERE A QUICK SHIFT TO
THE NW BEHIND THE THE FRONT EARLY THIS MORNING WILL LIKELY RESULT IN
A FEW HOURS OF CHOPPY CONDITIONS. SMALL CRAFT ADVISORY WILL BE
CONTINUED THROUGH EARLY AFTERNOON FOR THIS REASON.
RECD A REPORT OF SEVERAL WATERSPOUTS ACCOMPANYING THE FRONT OVER
LAKE ERIE EARLIER THIS MORNING SO WILL INCLUDE A CHANCE OF A
WATERSPOUT FOR EASTERN LAKES ERIE AND ONTARIO THROUGH EARLY
AFTERNOON.
THIS AFTERNOON...WINDS WILL SHIFT TO THE WNW BEHIND THE FRONT.
THIS FLOW WILL PERSIST...AND WILL LIKELY PRODUCE WAVES TO 5 FT ON
EASTERN PORTIONS OF LAKE ONTARIO MID-AFTERNOON ONWARD. WINDS WILL
GRADUALLY DIMINISH LATE TONIGHT.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR LEZ040-
041.
SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 2 AM
EDT SATURDAY FOR LOZ044-045.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL/LEVAN
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...APFFEL
MARINE...APFFEL/LEVAN
AREA FORECAST DISCUSSION
NWS BUFFALO NY
721 AM EDT FRI AUG 17 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE REGION THROUGH THIS MORNING
PRODUCING A BAND OF SHOWERS AND POSSIBLY A THUNDERSTORM. FOLLOWING
THE PASSAGE OF THE COLD FRONT EXPECT COOLER TEMPERATURES AND LESS
HUMID CONDITIONS FOR THIS AFTERNOON AND THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AT DAYBREAK...A COLD FRONTAL BOUNDARY EXTENDED ALONG A JAMESTOWN TO
BUFFALO LINE. THERE ARE TWO AREAS OF SHOWERS ASSOCIATED WITH
THIS FRONT...THE FIRST OUT AHEAD OF THE FRONT...AND A SECOND JUST
BEHIND THE WIND SHIFT. SHOWERS WILL MOVE EASTWARD WITH THE FRONT.
WHILE MOST LOCATIONS WILL RECEIVE SOME RAINFALL FROM THE
FRONT...IT WILL VARY BY LOCATION...WITH HEAVIEST RAINS LIKELY
SOUTH OF BUFFALO...AND ALSO EAST OF LAKE ONTARIO. THE COMMON
FACTOR WITH THESE TWO LOCATIONS IS THAT LAKE MOISTURE IS ABLE TO
ENHANCE SHOWERS WITH THE FRONT. WHILE A THUNDERSTORM CAN/T BE
RULED OUT THROUGH THIS MORNING...THE CHANCE APPEARS TO BE
DIMINISHING AS SHOWERS WORK EASTWARD AWAY FROM THE MOISTURE OF
LAKE ERIE.
THE FRONT WILL EXIT TO THE EAST BY THIS AFTERNOON...WHICH WILL END
THE STEADY RAIN SHOWERS. HOWEVER...WITH COOLER AIR MOVING IN BEHIND
THE FRONT...AND THE RELATIVELY WARM LAKES...EXPECT ANY BRIEF
CLEARING WILL LIKELY FILL IN WITH LAKE-AIDED STRATOCUMULUS THIS
AFTERNOON. THE HRRR HAS CONSISTENTLY DEVELOPED SHOWERS AS A SW FLOW
OFF LAKE ERIE CONVERGES WITH A MORE WNW FLOW. FEEL THIS IS A REAL
POSSIBILITY...SO WILL CARRY A CHANCE FOR SHOWERS CENTERED IN THE
NORTHTOWNS WHERE THIS CONVERGENCE TYPICALLY OCCURS.
OTHERWISE...HIGH PRESSURE WILL BUILD ACROSS THE REGION FROM THE WEST
TONIGHT. THIS SHOULD RESULT IN A GENERAL DRYING TREND...WHERE
LINGERING CLOUDS FROM THE DAY SHOULD DISSIPATE. THIS SAID...A MORE
WESTERLY FLOW ON LAKE ONTARIO MAY ALLOW FOR LAKE CONVERGENCE CLOUDS
TO DEVELOP AND MOVE EAST OF LAKE ONTARIO LATE TONIGHT. THERE SHOULD
BE AMPLE PERIODS OF CLEARING TO ALLOW FOR TEMPERATURES TO COOL
CONSIDERABLY TONIGHT. LOWS WILL LIKELY RANGE FROM THE MID AND UPPER
40S IN THE COOL VALLEYS OF THE SOUTHERN TIER AND EAST OF LAKE ONTARIO...TO
THE LOWER 50S ELSEWHERE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
DURING THE WEEKEND...OUR REGION WILL REMAIN UNDER THE INFLUENCE OF
DEEP UPPER TROUGHING CENTERED NEAR JAMES BAY...WHILE SURFACE BASED
RIDGING OVER THE OHIO VALLEY AND LOWER LAKES GRADUALLY EXPANDS
NORTHEASTWARD INTO NEW ENGLAND.
UNDER THIS PATTERN...COOLER AND MAINLY DRY WEATHER WILL BE
PREDOMINANT. WHILE TEMPS ALOFT WILL BE CERTAINLY COOL ENOUGH FOR A
LAKE RESPONSE...THE RELATIVELY DRY NATURE OF OUR AIRMASS AND A FAIR
AMOUNT OF LOW LEVEL SHEAR SHOULD PREVENT MUCH MORE THAN SOME
LAKE-DRIVEN STRATOCU DOWNWIND OF THE LAKES EARLY SATURDAY
MORNING...AND AGAIN LATER SATURDAY NIGHT INTO EARLY SUNDAY.
SYNOPTICALLY...THE NAM/GFS/ECMWF ALL TRY TO SPIT OUT SOME SPOTTY
LIGHT SHOWERS ACROSS PARTS OF THE AREA SUNDAY AFTERNOON WITH DAYTIME
HEATING AND THE APPROACH OF A MODEST SHORTWAVE...BUT THIS STILL
APPEARS TO BE WORTHY OF NO MORE THAN SOME SLIGHT CHANCE POPS GIVEN
ONLY VERY LIMITED AMOUNTS OF AVAILABLE MOISTURE.
IN TERMS OF ACTUAL TEMPERATURES...850 MB READINGS WILL AVERAGE IN
THE +7C TO +9C RANGE SATURDAY...AND A DEGREE OR SO WARMER THAN THAT
ON SUNDAY. THIS WILL TRANSLATE INTO COMFORTABLE HIGHS IN THE LOWER
70S ON SATURDAY...AND THE LOWER TO MID 70S ON SUNDAY. MEANWHILE...
NIGHTTIME LOWS SATURDAY NIGHT WILL RANGE FROM THE MID 40S ACROSS
INTERIOR SECTIONS OF THE SOUTHERN TIER AND NORTH COUNTRY TO THE
LOWER 50S ALONG THE LAKE PLAINS...BEFORE MODERATING A FEW DEGREES
FOR SUNDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
THE COOL WEATHER OF THE SHORT TERM PERIOD WILL PERSIST INTO THE
FIRST COUPLE DAYS OF THE EXTENDED RANGE AS WELL...AS THE LARGE-SCALE
UPPER TROUGH REMAINS IN PLACE ACROSS THE GREAT LAKES AND NORTHEAST.
WITH DAYTIME HEATING OF THE STILL-COOL AIRMASS ALOFT...THE PASSAGE
OF A VERY WEAK SURFACE TROUGH COULD SET OFF SOME ISOLATED SHOWER AND
THUNDERSTORM ACTIVITY ON MONDAY...WITH THE APPROACH AND PASSAGE OF
THE MAIN UPPER TROUGH AXIS POSSIBLY DOING THE SAME ON TUESDAY. WILL
ACCORDINGLY KEEP SLIGHT CHANCE POPS IN PLACE FOR BOTH DAYS...WITH
ANY PRECIP THAT DOES FORM DIMINISHING WITH THE LOSS OF HEATING BOTH
MONDAY AND TUESDAY EVENINGS. 850 MB TEMPS LINGERING IN THE +8C TO
+10C RANGE WILL SUPPORT HIGHS IN THE LOWER TO MID 70S BOTH
DAYS...WITH NIGHTTIME LOWS IN THE 50S EXPECTED BOTH NIGHTS.
AFTER THAT...THE GFS AND ECMWF REMAIN IN GOOD AGREEMENT ON THE CORE
OF THE UPPER TROUGH LIFTING OFF INTO LABRADOR AND THEN INTO THE
NORTHERN ATLANTIC...WITH A RELATIVELY FLAT ZONAL FLOW SETTING UP
ACROSS THE LOWER LAKES AND NORTHEAST IN ITS WAKE. THE ENSUING WARM
AIR ADVECTION PATTERN WILL RESULT IN A GRADUAL WARMING TREND THROUGH
THE PERIOD...WITH DAYTIME HIGHS RECOVERING TO NEAR THE 80 DEGREE
MARK BY THURSDAY...AND NIGHTTIME LOWS ALSO MODERATING A FEW DEGREES
EACH NIGHT. AS FOR PRECIP CHANCES...THESE LOOK TO BE PRACTICALLY NIL
ON WEDNESDAY WITH THE DEPARTURE OF THE TROUGH AND LOW-LEVEL RIDGING
REMAINING IN PLACE...BEFORE CLIMBING BACK INTO THE SLIGHT CHANCE
RANGE ON THURSDAY WITH THE APPROACH OF ANOTHER WEAK SURFACE TROUGH.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
A COLD FRONT WHICH HAS JUST REACHED IAG/BUF/JHW THROUGH 12Z WILL
CONTINUE TO PUSH QUICKLY TO THE EAST. SHOWS WILL LINGER BRIEFLY
BEHIND THE BOUNDARY THIS MORNING...BUT SHOULD GIVE WAY TO FAIR
WEATHER. EVEN WITH THE SHOWERS...EXPECT MVFR/VFR CONDITIONS. THERE
IS STILL A CHANCE FOR THUNDERSTORMS...MAINLY AT ART WHICH IS STILL
AHEAD OF THE FRONT. THUNDERSTORMS MAY BRIEFLY DROP VSBY TO 2SM OR
LESS.
FOLLOWING THE PASSAGE OF THE COLD FRONT EXPECT THE VFR
LEVEL DECK TO TEMPORARILY SCATTER OUT THIS MORNING...ONLY TO FILL
BACK IN AGAIN WITH DAYTIME HEATING AS MOISTURE BECOMES TRAPPED
BENEATH THE SUBSIDENCE INVERSION. EXPECT MOST IF NOT ALL OF THIS
POST-FRONTAL CLOUD COVER TO BE VFR IN THE 035-050 KFT RANGE. THERE
MAY BE A STRAY SHOWERS IN THE VICINITY OF BUF THIS AFTERNOON DUE
TO THE CONVERGENCE OF A SW FLOW UP LAKE ERIE AND A WNW FLOW ELSEWHERE.
CLOUDS SHOULD SLOWLY SCATTER OUT TONIGHT AS WINDS OFF THE LAKES
DIMINISH...AND DRIER AIR MOVES IN. THERE COULD BE SOME FOG IN
JHW...OTHERWISE EXPECT VFR CONDITIONS TONIGHT.
OUTLOOK...
SATURDAY...POSSIBLE MVFR/IFR IN FOG EARLY OTHERWISE VFR.
SUNDAY...VFR.
MONDAY...CHANCE OF SHOWERS/TSTMS. MAINLY VFR.
TUESDAY...VFR.
&&
.MARINE...
A COLD FRONT WILL MOVE ACROSS THE WATERS FROM WEST TO EAST THIS
MORNING. WINDS WILL BRIEFLY BE BREEZY AHEAD OF THE FRONT...BUT THE
SSW WIND DIRECTION IS UNFAVORABLE FOR BUILDING WAVES ON LAKE
ONTARIO. DO HAVE SOME CONCERN ON LAKE ERIE...WHERE A QUICK SHIFT TO
THE NW BEHIND THE THE FRONT EARLY THIS MORNING WILL LIKELY RESULT IN
A FEW HOURS OF CHOPPY CONDITIONS. BECAUSE OF THIS WILL ISSUE A BRIEF
SMALL CRAFT ADVISORY FOR LAKE ERIE THROUGH LATE MORNING.
WITH SHOWERS AND THUNDERSTORMS MOVING ACROSS THE LAKES THROUGH THIS
MORNING...AN ISOLATED WATERSPOUT CANNOT BE RULED OUT. THIS
SAID...TEMPERATURES ALOFT ARE NOT AS COLD AS A FEW DAYS AGO...SO ANY
ACTIVITY SHOULD NOT BE AS NEARLY WIDESPREAD.
THIS AFTERNOON...WINDS WILL SHIFT TO THE WNW BEHIND THE FRONT. THIS
FLOW WILL PERSIST...AND WILL LIKELY PRODUCE WAVES TO 5 FT ON EASTERN
PORTIONS OF LAKE ONTARIO MID-AFTERNOON ONWARD. WINDS WILL GRADUALLY
DIMINISH LATE TONIGHT.
FINE BOATING CONDITIONS ARE THEN EXPECTED FOR THE WEEKEND.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR LEZ040-
041.
SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 2 AM
EDT SATURDAY FOR LOZ044-045.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...APFFEL
MARINE...APFFEL
AREA FORECAST DISCUSSION
NWS BUFFALO NY
645 AM EDT FRI AUG 17 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE REGION THROUGH THIS MORNING
PRODUCING A BAND OF SHOWERS AND POSSIBLY A THUNDERSTORM. FOLLOWING
THE PASSAGE OF THE COLD FRONT EXPECT COOLER TEMPERATURES AND LESS
HUMID CONDITIONS FOR THIS AFTERNOON AND THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AT DAYBREAK...A COLD FRONTAL BOUNDARY EXTENDED ALONG A JAMESTOWN TO
BUFFALO LINE. THERE ARE TWO AREAS OF SHOWERS ASSOCIATED WITH
THIS FRONT...THE FIRST OUT AHEAD OF THE FRONT...AND A SECOND JUST
BEHIND THE WIND SHIFT. SHOWERS WILL MOVE EASTWARD WITH THE FRONT.
WHILE MOST LOCATIONS WILL RECEIVE SOME RAINFALL FROM THE
FRONT...IT WILL VARY BY LOCATION...WITH HEAVIEST RAINS LIKELY
SOUTH OF BUFFALO...AND ALSO EAST OF LAKE ONTARIO. THE COMMON
FACTOR WITH THESE TWO LOCATIONS IS THAT LAKE MOISTURE IS ABLE TO
ENHANCE SHOWERS WITH THE FRONT. WHILE A THUNDERSTORM CAN/T BE
RULED OUT THROUGH THIS MORNING...THE CHANCE APPEARS TO BE
DIMINISHING AS SHOWERS WORK EASTWARD AWAY FROM THE MOISTURE OF
LAKE ERIE.
THE FRONT WILL EXIT TO THE EAST BY THIS AFTERNOON...WHICH WILL END
THE STEADY RAIN SHOWERS. HOWEVER...WITH COOLER AIR MOVING IN BEHIND
THE FRONT...AND THE RELATIVELY WARM LAKES...EXPECT ANY BRIEF
CLEARING WILL LIKELY FILL IN WITH LAKE-AIDED STRATOCUMULUS THIS
AFTERNOON. THE HRRR HAS CONSISTENTLY DEVELOPED SHOWERS AS A SW FLOW
OFF LAKE ERIE CONVERGES WITH A MORE WNW FLOW. FEEL THIS IS A REAL
POSSIBILITY...SO WILL CARRY A CHANCE FOR SHOWERS CENTERED IN THE
NORTHTOWNS WHERE THIS CONVERGENCE TYPICALLY OCCURRS.
OTHERWISE...HIGH PRESSURE WILL BUILD ACROSS THE REGION FROM THE WEST
TONIGHT. THIS SHOULD RESULT IN A GENERAL DRYING TREND...WHERE
LINGERING CLOUDS FROM THE DAY SHOULD DISSIPATE. THIS SAID...A MORE
WESTERLY FLOW ON LAKE ONTARIO MAY ALLOW FOR LAKE CONVERGENCE CLOUDS
TO DEVELOP AND MOVE EAST OF LAKE ONTARIO LATE TONIGHT. THERE SHOULD
BE AMPLE PERIODS OF CLEARING TO ALLOW FOR TEMPERATURES TO COOL
CONSIDERABLY TONIGHT. LOWS WILL LIKELY RANGE FROM THE MID AND UPPER
40S IN THE COOL VALLEYS OF THE SOUTHERN TIER AND EAST OF LAKE ONTARIO...TO
THE LOWER 50S ELSEWHERE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
DURING THE WEEKEND...OUR REGION WILL REMAIN UNDER THE INFLUENCE OF
DEEP UPPER TROUGHING CENTERED NEAR JAMES BAY...WHILE SURFACE BASED
RIDGING OVER THE OHIO VALLEY AND LOWER LAKES GRADUALLY EXPANDS
NORTHEASTWARD INTO NEW ENGLAND.
UNDER THIS PATTERN...COOLER AND MAINLY DRY WEATHER WILL BE
PREDOMINANT. WHILE TEMPS ALOFT WILL BE CERTAINLY COOL ENOUGH FOR A
LAKE RESPONSE...THE RELATIVELY DRY NATURE OF OUR AIRMASS AND A FAIR
AMOUNT OF LOW LEVEL SHEAR SHOULD PREVENT MUCH MORE THAN SOME
LAKE-DRIVEN STRATOCU DOWNWIND OF THE LAKES EARLY SATURDAY
MORNING...AND AGAIN LATER SATURDAY NIGHT INTO EARLY SUNDAY.
SYNOPTICALLY...THE NAM/GFS/ECMWF ALL TRY TO SPIT OUT SOME SPOTTY
LIGHT SHOWERS ACROSS PARTS OF THE AREA SUNDAY AFTERNOON WITH DAYTIME
HEATING AND THE APPROACH OF A MODEST SHORTWAVE...BUT THIS STILL
APPEARS TO BE WORTHY OF NO MORE THAN SOME SLIGHT CHANCE POPS GIVEN
ONLY VERY LIMITED AMOUNTS OF AVAILABLE MOISTURE.
IN TERMS OF ACTUAL TEMPERATURES...850 MB READINGS WILL AVERAGE IN
THE +7C TO +9C RANGE SATURDAY...AND A DEGREE OR SO WARMER THAN THAT
ON SUNDAY. THIS WILL TRANSLATE INTO COMFORTABLE HIGHS IN THE LOWER
70S ON SATURDAY...AND THE LOWER TO MID 70S ON SUNDAY. MEANWHILE...
NIGHTTIME LOWS SATURDAY NIGHT WILL RANGE FROM THE MID 40S ACROSS
INTERIOR SECTIONS OF THE SOUTHERN TIER AND NORTH COUNTRY TO THE
LOWER 50S ALONG THE LAKE PLAINS...BEFORE MODERATING A FEW DEGREES
FOR SUNDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
THE COOL WEATHER OF THE SHORT TERM PERIOD WILL PERSIST INTO THE
FIRST COUPLE DAYS OF THE EXTENDED RANGE AS WELL...AS THE LARGE-SCALE
UPPER TROUGH REMAINS IN PLACE ACROSS THE GREAT LAKES AND NORTHEAST.
WITH DAYTIME HEATING OF THE STILL-COOL AIRMASS ALOFT...THE PASSAGE
OF A VERY WEAK SURFACE TROUGH COULD SET OFF SOME ISOLATED SHOWER AND
THUNDERSTORM ACTIVITY ON MONDAY...WITH THE APPROACH AND PASSAGE OF
THE MAIN UPPER TROUGH AXIS POSSIBLY DOING THE SAME ON TUESDAY. WILL
ACCORDINGLY KEEP SLIGHT CHANCE POPS IN PLACE FOR BOTH DAYS...WITH
ANY PRECIP THAT DOES FORM DIMINISHING WITH THE LOSS OF HEATING BOTH
MONDAY AND TUESDAY EVENINGS. 850 MB TEMPS LINGERING IN THE +8C TO
+10C RANGE WILL SUPPORT HIGHS IN THE LOWER TO MID 70S BOTH
DAYS...WITH NIGHTTIME LOWS IN THE 50S EXPECTED BOTH NIGHTS.
AFTER THAT...THE GFS AND ECMWF REMAIN IN GOOD AGREEMENT ON THE CORE
OF THE UPPER TROUGH LIFTING OFF INTO LABRADOR AND THEN INTO THE
NORTHERN ATLANTIC...WITH A RELATIVELY FLAT ZONAL FLOW SETTING UP
ACROSS THE LOWER LAKES AND NORTHEAST IN ITS WAKE. THE ENSUING WARM
AIR ADVECTION PATTERN WILL RESULT IN A GRADUAL WARMING TREND THROUGH
THE PERIOD...WITH DAYTIME HIGHS RECOVERING TO NEAR THE 80 DEGREE
MARK BY THURSDAY...AND NIGHTTIME LOWS ALSO MODERATING A FEW DEGREES
EACH NIGHT. AS FOR PRECIP CHANCES...THESE LOOK TO BE PRACTICALLY NIL
ON WEDNESDAY WITH THE DEPARTURE OF THE TROUGH AND LOW-LEVEL RIDGING
REMAINING IN PLACE...BEFORE CLIMBING BACK INTO THE SLIGHT CHANCE
RANGE ON THURSDAY WITH THE APPROACH OF ANOTHER WEAK SURFACE TROUGH.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
THROUGH 09Z...RADAR SHOWS A FAIRLY SOLID LINE OF SHOWERS WITH
EMBEDDED THUNDERSTORMS ACROSS AND JUST EAST OF LAKE ERIE. THIS
WILL BRING A PERIOD OF RAIN TO TAF SITES...AND PERHAPS A
THUNDERSTORM. CONDITIONS SHOULD MAINLY BE VFR OUTSIDE OF HEAVIER
RAIN SHOWERS WHICH MAY BRIEFLY LOWER VSBY TO AROUND 2SM.
FOLLOWING THE PASSAGE OF THE COLD FRONT EXPECT THE VFR LEVEL DECK TO
TEMPORARILY SCATTER OUT FRIDAY MORNING...ONLY TO FILL BACK IN AGAIN
WITH DAYTIME HEATING AS MOISTURE BECOMES TRAPPED BENEATH THE
SUBSIDENCE INVERSION. EXPECT MOST IF NOT ALL OF THIS POST-FRONTAL
CLOUD COVER TO BE VFR IN THE 035-050 KFT RANGE. THIS DECK SHOULD
SLOWLY SCATTER OUT TONIGHT AS WINDS OFF THE LAKES DIMINISH...AND
DRIER AIR MOVES IN.
OUTLOOK...
SATURDAY...POSSIBLE MVFR/IFR IN FOG EARLY OTHERWISE VFR.
SUNDAY...VFR.
MONDAY...CHANCE OF SHOWERS/TSTMS. MAINLY VFR.
TUESDAY...VFR.
&&
.MARINE...
A COLD FRONT WILL MOVE ACROSS THE WATERS FROM WEST TO EAST THIS
MORNING. WINDS WILL BRIEFLY BE BREEZY AHEAD OF THE FRONT...BUT THE
SSW WIND DIRECTION IS UNFAVORABLE FOR BUILDING WAVES ON LAKE
ONTARIO. DO HAVE SOME CONCERN ON LAKE ERIE...WHERE A QUICK SHIFT TO
THE NW BEHIND THE THE FRONT EARLY THIS MORNING WILL LIKELY RESULT IN
A FEW HOURS OF CHOPPY CONDITIONS. BECAUSE OF THIS WILL ISSUE A BRIEF
SMALL CRAFT ADVISORY FOR LAKE ERIE THROUGH LATE MORNING.
WITH SHOWERS AND THUNDERSTORMS MOVING ACROSS THE LAKES THROUGH THIS
MORNING...AN ISOLATED WATERSPOUT CANNOT BE RULED OUT. THIS
SAID...TEMPERATURES ALOFT ARE NOT AS COLD AS A FEW DAYS AGO...SO ANY
ACTIVITY SHOULD NOT BE AS NEARLY WIDESPREAD.
THIS AFTERNOON...WINDS WILL SHIFT TO THE WNW BEHIND THE FRONT. THIS
FLOW WILL PERSIST...AND WILL LIKELY PRODUCE WAVES TO 5 FT ON EASTERN
PORTIONS OF LAKE ONTARIO MID-AFTERNOON ONWARD. WINDS WILL GRADUALLY
DIMINISH LATE TONIGHT.
FINE BOATING CONDITIONS ARE THEN EXPECTED FOR THE WEEKEND.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR LEZ040-
041.
SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 2 AM
EDT SATURDAY FOR LOZ044-045.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...APFFEL
MARINE...APFFEL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
955 AM EDT FRI AUG 17 2012
.SYNOPSIS...
A LEE TROUGH WILL REMAIN OVER THE PIEDMONT TODAY...IN ADVANCE OF A
COLD FRONT THAT WILL APPROACH SLOWLY FROM THE NORTHWEST AND SETTLE
THROUGH THE AREA ON SATURDAY.
&&
.NEAR TERM /THROUGH SATURDAY NIGHT/...
AS OF 955 AM FRIDAY...
TODAY...
CLEAR SKIES ARE OBSERVED ACROSS THE AREA THIS MORNING AS
CONVECTIVE/FRONTAL CLOUD COVER REMAINS MOSTLY WEST OF THE
MOUNTAINS. THE 12Z KGSO RAOB HAD A 1408M LOW LEVEL
THICKNESS...WHICH YIELDS HIGHS OF 88-92 UNDER FULL SUN...CONSISTENT
WITH THE CURRENT FORECAST. REMNANT OUTFLOW AND A SHEARING LOBE OF
VORTICITY APPROACHING THE MOUNTAINS FROM THE WEST WILL BE THE MAIN
FOCUS FOR ANY CONVECTION THIS AFTERNOON. THE RAP SHOWS TWO AREAS OF
STRONGER VORTICITY...ONE DIVING SOUTH INTO NORTHERN GA..AND THE
SECOND STRADDLING THE NC/VA BORDER THIS EVENING. DEWPOINTS ARE
CURRENTLY IN THE LOW TO MID 60S OVER THE WESTERN PIEDMONT..AND
ALTHOUGH THE LEE TROUGH WILL SHARPEN AHEAD OF THE BROAD CYCLONIC
FLOW DEVELOPING OVER THE EASTERN US...GUIDANCE DOES NOT SHOW MUCH
DEWPOINT RECOVERY ALONG THE TROUGH AXIS UNTIL LATE THIS EVENING AND
OVERNIGHT. COMBINED WITH WEAK LAPSE RATES ALOFT...ONLY A WEAK
INSTABILITY AXIS OF 500 TO MAYBE 1000 J/KG MLCAPE IS ANTICIPATED
EAST OF THE MOUNTAINS THIS AFTERNOON. PW IS RELATIVELY LOW ACROSS
THE CWA THIS MORNING...DOWN AROUND ONE INCH...BUT IS FORECAST TO
SURGE TO NEAR 1.75 INCHES THIS EVENING AS GOOD MID-LEVEL MOISTURE
ADVECTS IN FROM THE WEST. SCATTERED SHOWERS AND STORMS MAY HAVE
INITIALLY HAVE A HARD TIME MOVING EAST OF THE MOUNTAINS THIS
AFTERNOON...BUT STEEP LOW LEVEL LAPSE RATES AND 20-25KT OF MID LEVEL
FLOW COULD SUPPORT ENHANCED DOWNDRAFTS FROM EVAPORATIONAL COOLING
AND A FEW STORM CLUSTERS WITH ORGANIZED COLD POOLS IF CONVECTION IS
AS ROBUST AS A COUPLE OF THE CAMS ARE SHOWING. -SMITH
OVERNIGHT: SHOWERS AND STORMS WILL DRIFT EASTWARD IN A WEAKENING
STATE OWING TO NOCTURNAL COOLING/STABILIZATION OVERNIGHT. WHILE
CONTINUED 20-30 KTS OF EFFECTIVE BULK SHEAR WILL PERSIST...THIS WILL
LIKELY BE INSUFFICIENT TO COMPENSATE FOR THE RELATIVE LACK OF
STEADILY DECREASING BUOYANCY...SO ANY PRIOR SEVERE WEATHER THREAT
SHOULD DIMINISH PRIOR TO MIDNIGHT. NONETHELESS...SOME SHOWERS AND
ISOLATED STORMS ARE APT TO CONTINUE THROUGHOUT THE NIGHT...AS THE
SYNOPTIC SURFACE FRONTAL -- WHICH SIGNIFICANTLY LAGS THE ONGOING
PRE-FRONTAL MCS/S...AND ASSOCIATED OUTFLOW THAT WILL LIKELY HAVE A
DIFFICULT TIME CRESTING THE BLUE RIDGE TODAY -- GRADUALLY SETTLES
INTO AT LEAST THE NORTHWEST PIEDMONT TOWARD SUNRISE. CLOUDY OR
MOSTLY SO...WITH LOWS IN LOWER 70S FOR MOST.
SATURDAY: THERE ARE MIXED SIGNALS WITH RESPECT TO CONVECTIVE
COVERAGE AND INTENSITY ON SATURDAY. ON ONE HAND...LOW LEVEL FORCING
SHOULD BE QUITE STRONG AS THE LOW LEVEL FRONTAL ZONE...DEEP THROUGH
AT LEAST H85...SETTLES SOUTHEASTWARD THROUGH ALL OF CENTRAL NC BY
EVENING - A CHANGE FROM THE EARLIER EXPECTATION THAT THE BOUNDARY
WOULD STALL OVERHEAD THROUGH EARLY NEXT WEEK. ON THE OTHER
HAND...HOWEVER...THE PRECEDING PASSAGE OF THE LEAD MID LEVEL TROUGH
AXIS THROUGH CENTRAL NC FRI NIGHT...AND ASSOCIATED TRAILING NEUTRAL
TO WEAKLY RISING HEIGHTS ALOFT...SUGGESTS DEEPER LAYER SUBSIDENCE
WILL BE IN PLACE OVERHEAD. GIVEN THE DEPTH AND VIGOR OF THE LOW
LEVEL FRONTAL ZONE...IN CONJUNCTION WITH LOW LCL/LFC HEIGHTS AMIDST
HIGH BL MOISTURE CHARACTERIZED BY WARM SECTOR SURFACE DEWPOINTS AOA
70 DEGREES AND TEMPERATURES IN THE 80S...WILL LEAN TOWARD A HIGHER
LIKELIHOOD OF SHOWERS AND STORMS...DESPITE THE DEEPER LAYER
SUBSIDENCE. WHILE PRECIPITATION CHANCES SHOULD DIMINISH FROM
NORTHWEST TO SOUTHEAST WITH TIME AND THE PASSAGE OF THE FRONTAL
ZONE...A FEW ANAFRONTAL SHOWERS MAY CONTINUE TO PERCOLATE ON THE
IMMEDIATE COOL SIDE OF THE BOUNDARY WHERE ISENTROPIC UPGLIDE AND
LINGERING...ALBEIT DIMINISHED WEAK INSTABILITY...WILL COINCIDE.
WHILE EFFECTIVE BULK SHEAR VALUES WILL INCREASE INTO THE 25 TO 40 KT
RANGE BY LATE AFTERNOON AND EVENING...IN ADVANCE OF A S/W TROUGH
FORECAST TO LIFT THROUGH THE MIDDLE ATLANTIC STATES...THIS BELT OF
STRONGER FLOW IS FORECAST TO LAG THE MODERATELY UNSTABLE WARM
SECTOR. AS SUCH...MULTI-CELL CONVECTIVE MODES WITH A PRIMARY THREAT
OF DAMAGING WINDS SHOULD DOMINATE...ALTHOUGH THERE MAY BE A RELATIVE
SWEET SPOT IN A NARROW CORRIDOR ROUGHLY FROM ROCKINGHAM TO RALEIGH
TO ROANOKE RAPIDS...WHERE MORE OPTIMAL VALUES OF SHEAR AND
INSTABILITY MAY CO-EXIST AND SUPPORT A CONDITIONAL THREAT OF BRIEF
SUPERCELLULAR STRUCTURES.
SAT NIGHT: DRY WITH POST-FRONTAL NORTH TO NORTHEASTERLY FLOW...WITH
LOWS IN THE 64 TO 70 DEGREE RANGE.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 320 AM EDT...
SURFACE TROUGH FORECAST TO BE EAST AND SOUTHEAST OF CENTRAL NORTH
CAROLINA AT SUNRISE SUNDAY... BUT WITH SURFACE DEWPOINTS IN EXCESS
OF 65 DEGREES AND A BROAD UPPER TROUGH EXTENDING SOUTH INTO THE GULF
STATES... RAIN CHANCES WILL CONTINUE. PRECIPITABLE WATERS ROUGHLY
1.5 INCHES NORTHWEST TO 1.75 INCHES SOUTHWEST... WITH SURFACE BASED
CAPE IN EXCESS OF 2500 JOULES SOUTHEAST... TO NEAR 2000 NORTHWEST.
MID LEVEL WINDS OF 35 TO 45 KNOTS AND MIXING HEIGHTS ONLY TO 4000
FEET. THE AIR MASS IS PRIMED FOR A FEW SEVERE THUNDERSTORMS IN THE
AFTERNOON WITH DAMAGING WINDS THE MAIN THREAT. THE BIGGEST CONCERN
IS LACK OF A SIGNIFICANT TRIGGER OTHER THAN DAYTIME HEATING. HOWEVER
CONVECTIVE TRIGGER TEMPERATURES ARE A LOW 80 TO 85 DEGREES... AND
WILL RETAIN AFTERNOON POPS OF 50 TO 60 PERCENT.
LOSS OF HEATING SHOULD END MOST CONVECTION... BUT A THUNDERSTORM OR
TWO COULD PERSIST PAST MIDNIGHT IN THIS ENVIRONMENT.
THE UPPER TROUGH CONTINUES ITS SLOW APPROACH FROM THE WEST MONDAY.
THE MID LEVEL PRESSURE GRADIENT TIGHTENS WITH A DEEP LAYER OF
SOUTHWEST WINDS OF 30 TO 45 KNOTS... STRONGEST SOUTHEAST.
PRECIPITABLE WATERS PERHAPS EXCEEDING TWO INCHES SOUTHEAST. 850
MILLIBAR TROUGH WILL BE NEAR OR EAST OF HIGHWAY ONE... AND HIGHEST
RAIN CHANCES WILL BE IN THAT AREA MONDAY AFTERNOON. FORTY PERCENT
POPS NORTHWEST TO 50 SOUTHEAST WITH THE THREAT FOR DAMAGING WINDS
SIMILARLY HIGHER SOUTHEAST THAN NORTHWEST DUE TO HIGHER INSTABILITY
AND POTENTIAL ENERGY.
WINDS ALOFT BEGIN TO WEAKEN A BIT MONDAY NIGHT... WITH SOME DRYING
ALOFT IN THE WEST AFTER MIDNIGHT. UNLESS THERE IS SOME MINOR SHORT
WAVE FOR UPPER LEVEL SUPPORT... MOST CONVECTION SHOULD END IN THE
EVENING. A VERY FEW SHOWERS OR A THUNDERSTORM COULD PERSIST PAST
MIDNIGHT... MAINLY NEAR AND EAST OF HIGHWAY ONE.
AFTERNOON LOW LEVEL THICKNESSES ABOUT FIVE METERS BELOW CLIMATOLOGY
SUNDAY... AND TEN TO FIFTEEN METERS MONDAY. TEMPERATURES BELOW
NORMAL... WITH HIGH TEMPERATURES 80 TO 85 SUNDAY... LOW 80S MONDAY.
LOWS BELOW NORMAL IN SPITE OF CLOUDS... AT LOWER 60S NORTHWEST TO
MID 60S SOUTHEAST.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 340 PM FRIDAY...
ROUGH CONSENSUS IN BEGINNING TO SHEAR OUT THE UPPER TROUGH TO OUR
WEST TUESDAY AS IT LIFTS NORTHEAST... WITH THE ECMWF MORE AGGRESSIVE
THAN THE GFS IN THIS PROCESS. A WEAK SURFACE TROUGH FORECAST NEAR OR
EAST OF INTERSTATE 95... AND WILL PLACE HIGHEST RAIN CHANCES THERE.
30 PERCENT RAIN CHANCE WELL EAST... WHICH MAY PROVE TOO LOW. LESS
THAN ONE IN SEVEN ELSEWHERE.
SIGNIFICANT DIFFERENCES IN THE UPPER LEVEL PATTERN FOR WEDNESDAY AND
THURSDAY IN THE MODELS... AND FORECAST IS OF BELOW AVERAGE
CONFIDENCE. ROUGH AGREEMENT IN SOUTHWEST FLOW ALOFT. THE CURRENT
FORECAST OF SLIGHT AFTERNOON RAIN CHANCES IS A BIT BELOW CLIMATOLOGY
BUT WITHIN REASON GIVEN UNCERTAINTY.
AFTERNOON TEMPERATURES WILL BE FORECAST NEAR TO A TOUCH BELOW
CLIMATOLOGY AT LOW TO MID 80S. LOW TEMPERATURES LOWER 60S NORTHWEST
TO MID 60S ELSEWHERE.
&&
.AVIATION /11Z FRIDAY THROUGH TUESDAY/...
AS OF 715 AM FRIDAY...
ASIDE FROM MAINLY MVFR FOG AT KRDU/KRWI/KFAY THIS MORNING...VFR
CONDITIONS ARE EXPECTED FOR THE MAJORITY OF THE 12Z TAF PERIOD.
HOWEVER...THE APPROACH OF A MID LEVEL TROUGH AND ASSOCIATED LIFT
WILL RESULT IN SCATTERED SHOWERS AND STORMS LATE THIS AFTERNOON INTO
TONIGHT...PARTICULARLY FROM KINT/KGSO TO KRDU/KFAY. THE BEST CHANCE
FOR THUNDER WILL BE IN THE 22-03Z TIME FRAME...WITH PRIMARILY JUST
SHOWERS THEREAFTER.
OUTLOOK...A COLD FRONT WILL SETTLE THROUGH CENTRAL NC WITH AN
ACCOMPANYING ENHANCED CHANCE OF SHOWERS AND STORMS ON SAT...FOLLOWED
BY DRY VFR CONDITIONS SAT NIGHT. THE BOUNDARY WILL RETREAT NORTHWARD
AND REMAIN IN THE VICINITY OF CENTRAL NC...AMIDST A MOIST AND
PERTURBED SOUTHWEST FLOW ALOFT...WITH A RENEWED THREAT OF SHOWERS
AND STORMS SUN-TUE.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...MWS/SMITH
SHORT TERM...
LONG TERM...
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1039 AM EDT FRI AUG 17 2012
.SYNOPSIS...
COLD FRONT PASSES THIS AFTERNOON INTO THIS EVENING. WEAK HIGH
PRESSURE OVER WEEKEND...WITH DISTURBANCE ALOFT PASSING SUNDAY.
ANOTHER HIGH PRESSURE BUILDS NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
1000AM UPDATE...
COLD FRONT AS OF 14Z LOCATED JUST NEAR CMH...TO ILN...DOWN THRU
CENTRAL KY. BEGINNING TO SEE FRONTAL BAND ORGANIZING ACROSS N KY
AND E OH. INITIAL CLEAR SKY ACROSS C AND E ZONES FILLING WITH
CLDS. LATEST HRRR SEEMS TO HAVE A GOOD HANDLE ON THINGS AND USED
IT FOR TIMING OF HIGHEST POPS. THINK THIS BAND WILL PROPAGATE E
AHEAD OF FRONT AS DAY WEARS ON...AFFECTING CENTRAL WV 16-18Z...AND
EXITING SW VA/WV MTNS BY 21Z. SPC HAS INSERTED SW VA AND WV MTN
COUNTIES IN SLIGHT RISK FOR THIS AFTN BUT GIVEN RAPID INCREASE IN
CLDS ACROSS THOSE AREAS...NOT SEEING MUCH OF A THREAT FOR SVR WITH
HRRR NOT SHOWING MUCH IN THE WAY OF SFC BASED INSTABILITY ALTHOUGH
RUC DOES PAINT DECENT CAPE VALUES ACROSS N WV MTNS EARLY THIS
AFTN. WILL LEAVE THUNDER IN ACROSS CENTRAL AND EASTERN ZONES. WITH
DEEPER MOISTURE EXODUS BY 21Z...WILL TAPER OFF POPS BUT STILL
LEAVE SCHC/LOW CHC TO ABOUT OH RVR WITH SFC FRONT STILL TO MOVE
THRU. WILL WATCH FOR WATER ACROSS S WV MTNS AND IN PARTICULAR SW
VA FOR POSSIBLE TRAINING THIS AFTN.
PREVIOUS DISCUSSION BELOW...
STILL A EVOLVING/DEVELOPING SITUATION FOR US TODAY...SO HOURLY
POPS...CLOUDS...AND TEMPERATURES DIFFICULT TO SAY THE LEAST.
STILL SEEING THE IMPRESSIVE SUPPORT FOR AUGUST FROM THE RIGHT REAR
OF A 250 MB JET MAX...PEAKING AROUND 18Z IN THE WV LOWLANDS...AND
INTO THE MOUNTAINOUS COUNTIES 21Z-00Z.
SO DESPITE THE MCS IN THE TN VALLEY STEALING THE SHOWER LAST
NIGHT...WILL TRY TO INCREASE POPS AGAIN BY 15Z IN THE OHIO RIVER
CORRIDOR...THEN STREAKING NE BY 18Z ALONG THE INTERSTATE 79
CORRIDOR SOUTH INTO THE SOUTHERN COAL FIELDS...THEN THROUGH THE
MOUNTAINOUS COUNTIES BY 21Z. PRIOR TO THAT...HAVE SOME SCATTERED
SHOWERS POSSIBLE TO START THE DAY IN THE OHIO RIVER VALLEY
COUNTIES...AND WILL BE SLOWER INTRODUCING EVEN CHANCE POPS CKB-EKN
DOWN TO BKW REGION.
WILL THE SLOWER ADVANCEMENT EAST...THE MOUNTAINOUS COUNTIES COULD
DEVELOP MORE CAPE AND INSTABILITY THIS AFTERNOON.
STILL MAY BE A FEW LEFTOVER SHOWERS BEHIND THE MID/UPPER LEVEL
SUPPORT ASSOCIATED WITH THE SURFACE FRONT. STILL HAVING THAT FRONT
NEAR CRW BY 00Z SATURDAY. WAS A BIT FASTER LOWERING POPS IN
SOUTHEAST OHIO THIS AFTERNOON.
WILL STILL HAVE TO WATCH OUR WET COUNTIES AROUND THE CENTRAL
MOUNTAINS AND IN THE SOUTHERN COAL FIELDS TODAY AND THIS EVENING FOR
ANY TRAINING...BUT WOULD BE PREMATURE TO POST ANY FLASH FLOOD WATCH
AT THIS HOUR.
THE DRIER AIR SHOULD WORK INTO THE MID OHIO VALLEY INCLUDING PKB
THIS EVENING...BUT MAY STRUGGLE TO PUSH PASS A EKN-CRW LINE. SO
HAVE LOW CONFIDENCE ON WHETHER CLOUDS WILL HOLD OR FOG WILL FORM IN
THOSE EASTERN AND SOUTHERN COUNTIES OVERNIGHT.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
SHORT TERM SHOULD START OUT WITH ANY LINGERING POPS ENDING AS COLD
FRONT AND MOISTURE CONTINUE MOVING AWAY FROM CWA. SURFACE HIGH
PRESSURE WILL SLIDE BY TO THE NORTH FOR THE FIRST HALF OF THE
WEEKEND KEEPING THINGS PRETTY DRY. BOTH 00Z GFS AND NAM SHOWING A
VORT MAX/SHORTWAVE TROUGH ASSOCIATED WITH CLOSED UPPER LOW NEAR
HUDSON BAY AT THE END OF THE SHORT TERM PERIOD...IMPACTING MAINLY
THE MOUNTAINS SUNDAY AFTERNOON INTO SUNDAY NIGHT. BASED ON FAIR
AGREEMENT BETWEEN 00Z GFS AND ECMWF...ADDED ANOTHER ROUND OF
ISOLATED SHOWERS MONDAY AFTERNOON...MAINLY IN THE NORTHERN
MOUNTAINS...AS ANOTHER 500MB RIPPLE SLIDES THROUGH.
TEMPS SHOULD GENERALLY BE A BIT BELOW NORMAL INTO EARLY NEXT WEEK.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
DRY WEATHER AND PLEASANT TEMPERATURES WILL PREVAIL THROUGH THE END
OF THE WEEK.
SOME WARM AIR ADVECTION NOTICED AT H850 FROM 11C TO 14-16C FROM
THE GFS/ECMWF UNDER WEAK SOUTHERLY FLOW FROM WED THROUGH THE END
OF THE WEEK. THEREFORE...INCREASED TEMPS TO THE MID TO UPPER 80S
SIMILAR TO HPC AND GMOS FROM WEDNESDAY THROUGH END OF THE PERIOD.
USED HPC TEMPS...WITH SOME TWEAKS DAY 5 THROUGH DAY 7.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
NEAR 10Z...COLD FRONT NEAR TOL TO SE INDIANA...WEST OF CVG.
WITH THE MCS COMPLEX IN THE TN VLY STEALING THE OVERNIGHT SHOW...WAS
SLOWER IN INCREASING POPS AND DROPPING CEILINGS. HAVE SOME
SCATTERED SHOWERS...NO THUNDER...INTO OHIO RIVER COUNTIES THRU 14Z.
CEILINGS MOSTLY 4 TO 8 THSD FT.
STILL STRONG SUPPORT ALOFT PASSING DURING THE LATE MORNING AND EARLY
AFTERNOON. TRIED TO INCREASE POPS 14Z TO 16Z AND SPREAD RAPIDLY
NORTHEAST INTO THE CKB AND EKN AREA BY 16-19Z...THEN NUDGING EAST IN
THE MOUNTAINOUS COUNTIES BY 21Z...WHILE LOWERING POPS IN SOUTHEAST
OHIO AND THE PKB VCNTY. MOSTLY SHOWERS WITH EMBEDDED THUNDERSTORMS.
A FEW STRONGER THUNDERSTORMS POSSIBLE FURTHER EAST AND SOUTHEAST...
OVER SOUTHWESTERN VIRGINIA AND W VA INTO BKW-EKN VCNTY 18Z TO 00Z.
YET...THE SURFACE FRONT WILL STILL BE APPROACHING THE OHIO
RIVER...LIKELY NOT REACHING CRW UNTIL AROUND 00Z. SOME LESS
WIDESPREAD CONVECTION POSSIBLE WITH THE FRONT ITSELF.
HAVE CEILINGS 2 TO 4 THSD FT BKN AND VSBY NEAR 3 MILES IN THE
CONVECTION.
LOW CONFIDENCE IN WHAT HAPPENS TO THE CEILINGS THIS
EVENING...ESPECIALLY EKN TO CRW ON SOUTH. THE DRIER AIR SHOULD
PENETRATE THE CKB TO PKB CORRIDOR...BUT HAVE CEILINGS DEVELOPING AT
1 TO 2 THSD FT BKN AND VSBY 3 TO 5 MILES 00Z TO 03Z IN THE
SOUTH...WITH LOWER CONDITIONS POSSIBLE AFTER 03Z SATURDAY.
AFTER 06Z...FIGURING WIDESPREAD CEILINGS AOB 1 THSD FT BKN AND VSBY
1 TO 3 MILES EKN-CRW ON SOUTH INCLUDING THE SRN WV MOUNTAINS AROUND
BECKLEY. LOWER CEILINGS MAY BEGIN TO LIFT BFR 12Z SATURDAY EKN-CRW.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z SATURDAY...
FORECAST CONFIDENCE: LOW.
ALTERNATE SCENARIOS: THE TIMING AND THE AREAL COVERAGE OF THE
SHOWERS/THUNDERSTORMS TODAY WILL VARY. FOG AND LOW CLOUDS MAY FORM
QUICKER THAN FORECAST IN SOUTHERN WEST VIRGINIA TONIGHT.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
CRW CONSISTENCY H M M M M H H H H H H H
HTS CONSISTENCY M M M H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H M M H H H H H L L
PKB CONSISTENCY M M H H H H H H H H H H
CKB CONSISTENCY H H M M M H H H H H H H
AFTER 12Z SATURDAY...
IFR POSSIBLE IN CEILINGS AND VSBY OVER SOUTHERN WEST VIRGINIA IN
POSSIBLE STRATUS AND/OR FOG.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...KTB/30
SHORT TERM...MZ
LONG TERM...ARJ
AVIATION...KTB
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1007 AM EDT FRI AUG 17 2012
.SYNOPSIS...
A COLD FRONT WILL PUSH SOUTHEAST ACROSS THE AREA TODAY. HIGH
PRESSURE WILL MOVE OVER THE AREA ON SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
COLD FRONT EAST OF THE AREA AND SOME SHOWERS ARE BEHIND IT. THE
SHOWERS WILL MOVE OUT QUICKLY THIS MORNING. THE CLOUDS ARE
DECREASING QUICKLY. HOWEVER WITH THE UPPER TROF IN THE AREA TODAY
AND PLENTY OF MOISTURE...THE HRRR MODEL AND SEVERAL OTHER MODELS
INDICATE THAT SOME ISOLATED SHOWERS COULD OCCUR INLAND OF THE
LAKE. ADDED A 20 POP FOR THE AFTERNOON. NO THUNDER AT THIS TIME
BUT THIS WILL HAVE TO BE WATCHED. NO CHANGE IN THE HIGH TEMPERATURES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
MODELS CONTINUE IN GOOD AGREEMENT MOVING LARGE AREA OF HIGH PRESSURE
EAST OVER THE AREA ON SATURDAY. AT THE UPPER LEVELS LONG WAVE
TROUGH DIGS OVER THE GREAT LAKES AND REMAINS NEARLY STATIONARY
THROUGH PERIOD. CONDITIONS SHOULD REMAIN RELATIVELY DRY WITH TEMPS
ACTUALLY BELOW NORMAL.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
NO BIG CHANGE FROM PREVIOUS FORECASTS. MODELS SHOW MODERATING
TEMPERATURES AS AN UPPER TROF PULLS EAST AND HEIGHTS RISE ACROSS THE
LOWER GREAT LAKES AND OHIO VALLEY. AT THE SURFACE...HIGH PRESSURE
WILL CONTINUE ACROSS THE AREA...SHIFTING EAST LATE IN THE PERIOD BUT
CONTINUING TO INFLUENCE THE AREA. WILL HAVE HIGHS RISING THROUGH
THE 70S TO THE LOWER 80S BY THURSDAY. PRECIP CHANCES MOSTLY SLIGHT
CHANCES TO NIL.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
COLD FRONT MOVING EAST OF THE AREA THIS HOUR WITH MVFR CIGS ACROSS
MAINLY THE EAST PORTION OF THE AREA. VFR CIGS IN THE CENTRAL WITH
CLEARING NORTHWEST. LIGHT RAIN SHOWERS ALSO OCCURRING IN A BROKEN
LINE FROM BETWEEN MFD AND MNN TO THE ERIE AREA. CIGS WILL LIFT TO
VFR THIS MORNING EAST WHILE CLEARING WILL CONTINUE TO PUSH EAST
INTO THE CENTRAL HIGHLANDS THIS MORNING AND THEN EAST THIS
AFTERNOON. EXPECT VFR CONDITIONS OVERNIGHT ALTHOUGH NEAR DAWN
EXPECT PATCH MVFR FOG/MIST.
.OUTLOOK...VFR EXCEPT FOR A CHANCE OF MVFR CEILINGS EXTREME
NE OH/NW PA MONDAY AND TUESDAY MORNING.
&&
.MARINE...
WILL GO WITH A SMALL CRAFT ADVISORY FOR TODAY. COLD FRONT IS NOW
MOVING ACROSS THE LAKE WITH 15 TO 20 KNOT WINDS AHEAD OF THE
BOUNDARY...GUSTING INTO THE 20S. BEHIND THE FRONT WINDS TURN
NORTHWEST WHICH WILL BRING THE HIGHEST WAVES ONTO THE SOUGH SHORE OF
THE LAKE. CURRENTLY BUOYS ARE REPORTING 3 FOOT WAVES AND WOULD
EXPECT A CONTINUED BUILD THROUGH LATE MORNING BEFORE BEGINNING TO
DROP BACK AS WINDS DIMINISH. BROAD HIGH PRESSURE WILL BUILD IN
SATURDAY AND CONTINUE TO AFFECT THE LAKE THROUGH THE REMAINDER OF
THE FORECAST.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR
LEZ145>149.
&&
$$
SYNOPSIS...DJB
NEAR TERM...KIELTYKA
SHORT TERM...DJB
LONG TERM...TK
AVIATION...TK
MARINE...TK
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1117 AM EDT FRI AUG 17 2012
.SYNOPSIS...
A STRONG COLD FRONT WILL TRAVERSE THE AREA TODAY ACCOMPANIED BY
SHOWERS AND THUNDERSTORMS. THE COLD FRONT WILL STALL OUT JUST
OFFSHORE NEW ENGLAND...AND EXTEND SOUTHWARD ALONG THE MID-ATLANTIC
PIEDMONT INTO SATURDAY. AN ANOMALOUS UPPER LEVEL TROUGH WILL
EVOLVE OVER THE EASTERN HALF OF THE NATION THROUGH EARLY NEXT
WEEK...RESULTING IN SLIGHTLY BELOW NORMAL TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
WEAKENING COLD FRONT PUSHING INTO MY NORTHWEST COUNTIES LATE THIS
MORNING. A FEW HOURS OF LIGHT TO MODERATE RAIN SHOWERS ARE ALL
THIS SYSTEM CAN MUSTER TO THIS POINT...AND EXPECT THAT TO BE THE
CASE IN THE SFC HEATING CHALLENGED ENVIRONMENT ACROSS CENTRAL PA
AS WELL. FAR SOUTHEAST PA MAY BE ABLE TO MUSTER A FEW HUNDRED J OF
CAPE THIS AFTERNOON...WITH SOME T BECOMING EMBEDDED IN THE MAIN
LINE AND PERHAPS ISOLATED CELLS FORMING AHEAD OF THE LINE. SEVERE
THREAT REMAINS LOW HOWEVER...AND THE FRONT WILL TAKE ITS TIME
CROSSING THE CENTRAL MOUNTAINS THIS AFTERNOON. RAIN MAY NOT REACH
ALL OF MY SOUTHEASTERN COUNTIES BY 00Z SAT. AS PREVIOUSLY MENTIONED...
IF THE OUTLIER SOLUTION OF BETTER INSTABILITY WERE TO BE REALIZED...
THE CONVECTIVE ENVIRONMENT COULD CONCEIVABLY SUPPORT SEMI-
ORGANIZED STRUCTURES WITH PERHAPS A MIX OF PULSE AND MULTICELL
STORM MODES. THE BEST CHC FOR STG STORMS IS LKLY OVR THE ERN 1/2
OF THE CWA GIVEN LESS CLOUDS/BETTER HEATING. LATEST HRRR UPDATE
VIA COSPA DEPICTS SLOW INTENSIFICATION OF THE CURRENT LINE OF
SHOWERS AS IT CROSSES THE CENTRAL MOUNTAINS EARLY THIS
AFTERNOON...AND APPROACHES THE LOWER SUSQ LATE THIS AFTERNOON AND
EVENING.
MUCH DRIER AIR WILL BE DIRECTED INTO THE AREA IN THE WAKE OF THE
COLD FRONT...WITH PCPN ENDING ACRS THE N/W HALF OF THE CWA BY LATE
AFTN/EARLY EVE. AS THE CLOSED LOW BECOMES NEARLY STATIONARY OVER
JAMES BAY..THE COLD FRONT WILL SLOW ITS EWD PROGRESSION AND REMAIN
A FOCUS FOR SHOWERS/ISOLD TSTMS ACRS THE SERN 1/2 OF THE CWA THRU
TNT. THE 17/00Z MDLS SHOW ONE OR MORE WAVES DEVELOPING ALONG THE
FNT AS IT SLOWS DOWN OVR ERN PA. THE NAM IS THE MOST AGGRESSIVE
WITH THIS FEATURE FOLLOWED BY THE CANADIAN. THE 00Z GFS IS MORE
PROGRESSIVE AND LOOKS SIMILAR TO THE UKMET/ECMWF. THEREFORE HAVE
INCREASED POPS INTO LKLY RANGE FOR THE FAR SE ZONES AFT 00Z.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
THE LG SCALE PATTERN WILL CONTINUE TO BE DOMINATED BY BROAD CYC
FLOW ALOFT ASSOCD WITH DEEP UPPER LEVEL TROUGH EXPANDING OVER THE
ERN CONUS...WITH HEIGHTS FCST TO REACH 3 SD BELOW NORMAL AT 500MB
OVER THE MS/OH VLYS. MUCH OF THE REGION WILL BE UNDER THE
INFLUENCE OF RELATIVELY COOL AND ABNORMALLY DRY SFC HIGH PRES
CENTERED OVR THE SRN GRT LKS/MIDWEST. THE FORECAST CHALLENGE FOR
D2 REVOLVES AROUND THE SLOWING/STALLING COLD FRONT OVR THE MID-
ATLC PIEDMONT...WHICH SHOULD SLOWLY DRIFT EWD TO THE COAST BY THE
END OF THE PD. THE NAM/GEM CONTINUE TO BE NORTH OF OTHER SOLUTIONS
AND KEEP PCPN GOING OVR SE PA INTO SAT EVE. WILL EMPLOY A MIDDLE
GROUND APPROACH AND KEEP LOW POPS GOING ACRS THE FAR SERN ZONES
THRU THE FIRST HALF OF D2. FCST TEMPS WILL AVG BELOW NORMAL ON
SAT.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
MDL DATA INDICATES THE DEEP UPPER LEVEL TROUGH WILL UNDERGO
ADDITIONAL AMPLIFICATION SUN-MON...AS SECONDARY S/W DROPS SWD FM
THE NRN PLAINS AND DIGS/SHARPENS THE TROUGH INTO THE LWR MS/TN
VLYS. IN RESPONSE TO HEIGHT FALLS AND ENHANCED UPPER LEVEL
DIVERGENCE VIA STRENGTHENING RT ENTRANCE REGION JET DYNAMICS...THE
ECMWF/CANADIAN FORM A LOW OVR THE SRN MID-ATLC COAST BY 12Z MON.
THE GFS HINTS AT THIS IDEA BUT IS NOT AS WELL-DEVELOPED WITH ITS
SFC LOW. CONSENSUS BLEND SUPPORTS LOW-END CHC POPS MAINLY FM SUN
NGT INTO THE DAY ON MONDAY.
THE HIGH-AMPLITUDE UPPER TROUGH EAST OF THE MS RIVER WILL REMAIN
Q-STNRY AND SLOWLY DEAMPLIFY INTO THE SECOND HALF OF THE PD TUE-
THURS. THIS PD SHOULD FEATURE MAINLY FAIR/DRY WEATHER WITH SFC
HIGH PRES IN CONTROL. RISING HEIGHTS AND GRADUAL RETURN FLOW WILL
LKLY ALLOW FOR A MODERATION IN TEMPS BACK TO AT LEAST SEASONAL
NORMALS...IF NOT ABOVE NORMAL.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
BAND OF SCATTERED SHOWERS STILL REMAINS OVER WESTERN PENNSYLVANIA
ASSOCIATED WITH THE ADVANCING COLD FRONT. THE FRONT AND ASSOCIATED
SHOWERS WILL MARCH ACROSS CENTRAL PENNSYLVANIA TODAY...REACHING
LOWER SUSQUEHANNA REGION AROUND 19Z. WHILE CIGS SHOULD REMAIN
GENERALLY IN THE VFR CATEGORY IN MOST AREAS...WILL SEE CIGS DROP
TO MVFR CONDITIONS SHORTLY IN KBFD WITH THE FRONT.
EXPECT MAINLY SHOWER ACTIVITY OVER AREAS WEST OF KUNV...WITH SOME
TSRA DEVELOPING OVER SOUTHEASTERN AREAS INCLUDING KMDT AND KLNS.
DID INCLUDE VCTS IN THE SOUTHEAST TAFS...BUT UNSURE OF JUST HOW
EXTENSIVE TSRA COVERAGE WILL BE.
COLD ADVECTION AND CYCLONIC FLOW ALOFT COUPLED WITH LOW LEVEL
MOISTURE LEFT OVER FROM TODAYS PRECIPITATION WILL LIKELY SPELL
SOME OVERNIGHT STRATUS AND FOG FRIDAY NIGHT WITH MVFR
CONDITIONS...AND SOME IFR IN THE NORTHERN AND WESTERN MOUNTAINS.
DRIER AND COOLER AIR WORKS IN FOR THE WEEKEND...AND EARLY NEXT WEEK.
OUTLOOK...
SAT-TUE...MAINLY VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...DEVOIR/STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...STEINBUGL
AVIATION...JUNG
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
747 AM EDT FRI AUG 17 2012
.SYNOPSIS...
A STRONG COLD FRONT WILL TRAVERSE THE AREA TODAY ACCOMPANIED BY
SHOWERS AND THUNDERSTORMS. THE COLD FRONT WILL STALL OUT JUST
OFFSHORE NEW ENGLAND...AND EXTEND SOUTHWARD ALONG THE MID-ATLANTIC
PIEDMONT INTO SATURDAY. AN ANOMALOUS UPPER LEVEL TROUGH WILL
EVOLVE OVER THE EASTERN HALF OF THE NATION THROUGH EARLY NEXT
WEEK...RESULTING IN SLIGHTLY BELOW NORMAL TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
11Z RADAR SHOWS LINE OF SHOWERS/LEADING EDGE OF SFC COLD FRONT
MOVING INTO NW WARREN CO. INCREASED POPS ACRS THE NW MTNS TO
CATEGORICAL FM 12-15Z AS STRONG 850MB MSTR FLUX/FRONTAL
CONVERGENCE COMBINES WITH ENHANCED UVM/DIV ALOFT ASSOCD WITH THE
RIGHT ENTRANCE REGION OF 85KT UPPER JET MAX TO PRODUCE A NEARLY
SOLID LINE OF SHOWERS/TSTMS. THE COSPA/HRRR IS HANDLING THE PCPN
EVOLUTION REASONABLY WELL SO FAR THIS MORNING...AND BRINGS
CONVECTION INTO THE WESTERN ALLEGHENIES/LAUREL HIGHLANDS 15-18Z.
A CLOSED H5 LOW WILL PIVOT EWD ACRS NRN ONTARIO AND BECOME NEARLY
STATIONARY OVER JAMES BAY...WITH A BROAD LONGWAVE TROUGH AND
CYCLONIC FLOW ALOFT OVERSPREADING THE GREAT LAKES/NORTHEAST/MID-
ATLANTIC REGIONS. AT THE SFC...SHOWERS AND TSTMS WILL BE FOCUSED
ALONG/AHEAD OF THE ATTENDANT COLD FRONT THAT WILL TRAVERSE THE
AREA BY TONIGHT. HAVE MAINTAINED LKLY-CATG POPS THRU 00Z WITH
BASIN-AVG QPF AMTS AROUND 0.25 INCH.
IT STILL APPEARS THAT RESIDUAL CLOUDS/PRECIPITATION MAY BE A
LIMITING FACTOR CONCERNING SVR WX POTENTIAL THIS AFTN. IN
ADDITION...MARGINAL/MODEST INSTABILITY AXIS PRECEDING THE FRONT
DOES NOT LINE UP WITH THE STRONGEST CYCLONIC FLOW ALOFT/DEEP LAYER
SHEAR WHICH LAGS TO THE WNW. SPC HAS KEPT THE AREA IN SEE TEXT
DUE TO THE UNCERTAINTY...AND IN GENERAL FEEL THAT THE OVERALL SET-
UP DOES NOT LOOK THAT FAVORABLE FOR SVR. HOWEVER IF BETTER
INSTABILITY CAN BE REALIZED...THE CONVECTIVE ENVIRONMENT WOULD
SUPPORT SEMI-ORGANIZED STRUCTURES WITH PERHAPS A MIX OF PULSE AND
MULTICELL STORM MODES. THE BEST CHC FOR STG TO SVR STORMS IS LKLY
OVR THE ERN 1/2 OF THE CWA GIVEN LESS CLOUDS/BETTER HEATING. THE
HIGH RES NAM AND HRRR SIMULATED REFLECTIVITY SUGGEST A LINE OF
ENHANCED STORMS WILL FORM NEAR AOO-UNV-IPT LINE BY 19Z.
MUCH DRIER AIR WILL BE DIRECTED INTO THE AREA IN THE WAKE OF THE
COLD FRONT...WITH PCPN ENDING ACRS THE N/W HALF OF THE CWA BY LATE
AFTN/EARLY EVE. AS THE CLOSED LOW BECOMES NEARLY STATIONARY OVER
JAMES BAY..THE COLD FRONT WILL SLOW ITS EWD PROGRESSION AND REMAIN
A FOCUS FOR SHOWERS/ISOLD TSTMS ACRS THE SERN 1/2 OF THE CWA THRU
TNT. THE 17/00Z MDLS SHOW ONE OR MORE WAVES DEVELOPING ALONG THE
FNT AS IT SLOWS DOWN OVR ERN PA. THE NAM IS THE MOST AGGRESSIVE
WITH THIS FEATURE FOLLOWED BY THE CANADIAN. THE 00Z GFS IS MORE
PROGRESSIVE AND LOOKS SIMILAR TO THE UKMET/ECMWF. THEREFORE HAVE
INCREASED POPS INTO LKLY RANGE FOR THE FAR SE ZONES AFT 00Z.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
THE LG SCALE PATTERN WILL CONTINUE TO BE DOMINATED BY BROAD CYC
FLOW ALOFT ASSOCD WITH DEEP UPPER LEVEL TROUGH EXPANDING OVER THE
ERN CONUS...WITH HEIGHTS FCST TO REACH 3 SD BELOW NORMAL AT 500MB
OVER THE MS/OH VLYS. MUCH OF THE REGION WILL BE UNDER THE
INFLUENCE OF RELATIVELY COOL AND ABNORMALLY DRY SFC HIGH PRES
CENTERED OVR THE SRN GRT LKS/MIDWEST. THE FORECAST CHALLENGE FOR
D2 REVOLVES AROUND THE SLOWING/STALLING COLD FRONT OVR THE MID-
ATLC PIEDMONT...WHICH SHOULD SLOWLY DRIFT EWD TO THE COAST BY THE
END OF THE PD. THE NAM/GEM CONTINUE TO BE NORTH OF OTHER SOLUTIONS
AND KEEP PCPN GOING OVR SE PA INTO SAT EVE. WILL EMPLOY A MIDDLE
GROUND APPROACH AND KEEP LOW POPS GOING ACRS THE FAR SERN ZONES
THRU THE FIRST HALF OF D2. FCST TEMPS WILL AVG BELOW NORMAL ON
SAT.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
MDL DATA INDICATES THE DEEP UPPER LEVEL TROUGH WILL UNDERGO
ADDITIONAL AMPLIFICATION SUN-MON...AS SECONDARY S/W DROPS SWD FM
THE NRN PLAINS AND DIGS/SHARPENS THE TROUGH INTO THE LWR MS/TN
VLYS. IN RESPONSE TO HEIGHT FALLS AND ENHANCED UPPER LEVEL
DIVERGENCE VIA STRENGTHENING RT ENTRANCE REGION JET DYNAMICS...THE
ECMWF/CANADIAN FORM A LOW OVR THE SRN MID-ATLC COAST BY 12Z MON.
THE GFS HINTS AT THIS IDEA BUT IS NOT AS WELL-DEVELOPED WITH ITS
SFC LOW. CONSENSUS BLEND SUPPORTS LOW-END CHC POPS MAINLY FM SUN
NGT INTO THE DAY ON MONDAY.
THE HIGH-AMPLITUDE UPPER TROUGH EAST OF THE MS RIVER WILL REMAIN
Q-STNRY AND SLOWLY DEAMPLIFY INTO THE SECOND HALF OF THE PD TUE-
THURS. THIS PD SHOULD FEATURE MAINLY FAIR/DRY WEATHER WITH SFC
HIGH PRES IN CONTROL. RISING HEIGHTS AND GRADUAL RETURN FLOW WILL
LKLY ALLOW FOR A MODERATION IN TEMPS BACK TO AT LEAST SEASONAL
NORMALS...IF NOT ABOVE NORMAL.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
BAND OF SCATTERED SHOWERS STILL REMAINS OVER WESTERN PENNSYLVANIA
ASSOCIATED WITH THE ADVANCING COLD FRONT. THE FRONT AND ASSOCIATED
SHOWERS WILL MARCH ACROSS CENTRAL PENNSYLVANIA TODAY...REACHING
LOWER SUSQUEHANNA REGION AROUND 19Z. WHILE CIGS SHOULD REMAIN
GENERALLY IN THE VFR CATEGORY IN MOST AREAS...WILL SEE CIGS DROP
TO MVFR CONDITIONS SHORTLY IN KBFD WITH THE FRONT.
EXPECT MAINLY SHOWER ACTIVITY OVER AREAS WEST OF KUNV...WITH SOME
TSRA DEVELOPING OVER SOUTHEASTERN AREAS INCLUDING KMDT AND KLNS.
DID INCLUDE VCTS IN THE SOUTHEAST TAFS...BUT UNSURE OF JUST HOW
EXTENSIVE TSRA COVERAGE WILL BE.
COLD ADVECTION AND CYCLONIC FLOW ALOFT COUPLED WITH LOW LEVEL
MOISTURE LEFT OVER FROM TODAYS PRECIPITATION WILL LIKELY SPELL
SOME OVERNIGHT STRATUS AND FOG FRIDAY NIGHT WITH MVFR
CONDITIONS...AND SOME IFR IN THE NORTHERN AND WESTERN MOUNTAINS.
DRIER AND COOLER AIR WORKS IN FOR THE WEEKEND...AND EARLY NEXT WEEK.
OUTLOOK...
SAT-TUE...MAINLY VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...STEINBUGL
AVIATION...JUNG
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
659 AM EDT FRI AUG 17 2012
.SYNOPSIS...
A STRONG COLD FRONT WILL TRAVERSE THE AREA TODAY ACCOMPANIED BY
SHOWERS AND THUNDERSTORMS. THE COLD FRONT WILL STALL OUT JUST
OFFSHORE NEW ENGLAND...AND EXTEND SOUTHWARD ALONG THE MID-ATLANTIC
PIEDMONT INTO SATURDAY. AN ANOMALOUS UPPER LEVEL TROUGH WILL
EVOLVE OVER THE EASTERN HALF OF THE NATION THROUGH EARLY NEXT
WEEK...RESULTING IN SLIGHTLY BELOW NORMAL TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
11Z RADAR SHOWS LINE OF SHOWERS/LEADING EDGE OF SFC COLD FRONT
MOVING INTO NW WARREN CO. INCREASED POPS ACRS THE NW MTNS TO
CATEGORICAL FM 12-15Z AS STRONG 850MB MSTR FLUX/FRONTAL
CONVERGENCE COMBINES WITH ENHANCED UVM/DIV ALOFT ASSOCD WITH THE
RIGHT ENTRANCE REGION OF 85KT UPPER JET MAX TO PRODUCE A NEARLY
SOLID LINE OF SHOWERS/TSTMS. THE COSPA/HRRR IS HANDLING THE PCPN
EVOLUTION REASONABLY WELL SO FAR THIS MORNING...AND BRINGS
CONVECTION INTO THE WESTERN ALLEGHENIES/LAUREL HIGHLANDS 15-18Z.
A CLOSED H5 LOW WILL PIVOT EWD ACRS NRN ONTARIO AND BECOME NEARLY
STATIONARY OVER JAMES BAY...WITH A BROAD LONGWAVE TROUGH AND
CYCLONIC FLOW ALOFT OVERSPREADING THE GREAT LAKES/NORTHEAST/MID-
ATLANTIC REGIONS. AT THE SFC...SHOWERS AND TSTMS WILL BE FOCUSED
ALONG/AHEAD OF THE ATTENDANT COLD FRONT THAT WILL TRAVERSE THE
AREA BY TONIGHT. HAVE MAINTAINED LKLY-CATG POPS THRU 00Z WITH
BASIN-AVG QPF AMTS AROUND 0.25 INCH.
IT STILL APPEARS THAT RESIDUAL CLOUDS/PRECIPITATION MAY BE A
LIMITING FACTOR CONCERNING SVR WX POTENTIAL THIS AFTN. IN
ADDITION...MARGINAL/MODEST INSTABILITY AXIS PRECEDING THE FRONT
DOES NOT LINE UP WITH THE STRONGEST CYCLONIC FLOW ALOFT/DEEP LAYER
SHEAR WHICH LAGS TO THE WNW. SPC HAS KEPT THE AREA IN SEE TEXT
DUE TO THE UNCERTAINTY...AND IN GENERAL FEEL THAT THE OVERALL SET-
UP DOES NOT LOOK THAT FAVORABLE FOR SVR. HOWEVER IF BETTER
INSTABILITY CAN BE REALIZED...THE CONVECTIVE ENVIRONMENT WOULD
SUPPORT SEMI-ORGANIZED STRUCTURES WITH PERHAPS A MIX OF PULSE AND
MULTICELL STORM MODES. THE BEST CHC FOR STG TO SVR STORMS IS LKLY
OVR THE ERN 1/2 OF THE CWA GIVEN LESS CLOUDS/BETTER HEATING. THE
HIGH RES NAM AND HRRR SIMULATED REFLECTIVITY SUGGEST A LINE OF
ENHANCED STORMS WILL FORM NEAR AOO-UNV-IPT LINE BY 19Z.
MUCH DRIER AIR WILL BE DIRECTED INTO THE AREA IN THE WAKE OF THE
COLD FRONT...WITH PCPN ENDING ACRS THE N/W HALF OF THE CWA BY LATE
AFTN/EARLY EVE. AS THE CLOSED LOW BECOMES NEARLY STATIONARY OVER
JAMES BAY..THE COLD FRONT WILL SLOW ITS EWD PROGRESSION AND REMAIN
A FOCUS FOR SHOWERS/ISOLD TSTMS ACRS THE SERN 1/2 OF THE CWA THRU
TNT. THE 17/00Z MDLS SHOW ONE OR MORE WAVES DEVELOPING ALONG THE
FNT AS IT SLOWS DOWN OVR ERN PA. THE NAM IS THE MOST AGGRESSIVE
WITH THIS FEATURE FOLLOWED BY THE CANADIAN. THE 00Z GFS IS MORE
PROGRESSIVE AND LOOKS SIMILAR TO THE UKMET/ECMWF. THEREFORE HAVE
INCREASED POPS INTO LKLY RANGE FOR THE FAR SE ZONES AFT 00Z.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
THE LG SCALE PATTERN WILL CONTINUE TO BE DOMINATED BY BROAD CYC
FLOW ALOFT ASSOCD WITH DEEP UPPER LEVEL TROUGH EXPANDING OVER THE
ERN CONUS...WITH HEIGHTS FCST TO REACH 3 SD BELOW NORMAL AT 500MB
OVER THE MS/OH VLYS. MUCH OF THE REGION WILL BE UNDER THE
INFLUENCE OF RELATIVELY COOL AND ABNORMALLY DRY SFC HIGH PRES
CENTERED OVR THE SRN GRT LKS/MIDWEST. THE FORECAST CHALLENGE FOR
D2 REVOLVES AROUND THE SLOWING/STALLING COLD FRONT OVR THE MID-
ATLC PIEDMONT...WHICH SHOULD SLOWLY DRIFT EWD TO THE COAST BY THE
END OF THE PD. THE NAM/GEM CONTINUE TO BE NORTH OF OTHER SOLUTIONS
AND KEEP PCPN GOING OVR SE PA INTO SAT EVE. WILL EMPLOY A MIDDLE
GROUND APPROACH AND KEEP LOW POPS GOING ACRS THE FAR SERN ZONES
THRU THE FIRST HALF OF D2. FCST TEMPS WILL AVG BELOW NORMAL ON
SAT.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
MDL DATA INDICATES THE DEEP UPPER LEVEL TROUGH WILL UNDERGO
ADDITIONAL AMPLIFICATION SUN-MON...AS SECONDARY S/W DROPS SWD FM
THE NRN PLAINS AND DIGS/SHARPENS THE TROUGH INTO THE LWR MS/TN
VLYS. IN RESPONSE TO HEIGHT FALLS AND ENHANCED UPPER LEVEL
DIVERGENCE VIA STRENGTHENING RT ENTRANCE REGION JET DYNAMICS...THE
ECMWF/CANADIAN FORM A LOW OVR THE SRN MID-ATLC COAST BY 12Z MON.
THE GFS HINTS AT THIS IDEA BUT IS NOT AS WELL-DEVELOPED WITH ITS
SFC LOW. CONSENSUS BLEND SUPPORTS LOW-END CHC POPS MAINLY FM SUN
NGT INTO THE DAY ON MONDAY.
THE HIGH-AMPLITUDE UPPER TROUGH EAST OF THE MS RIVER WILL REMAIN
Q-STNRY AND SLOWLY DEAMPLIFY INTO THE SECOND HALF OF THE PD TUE-
THURS. THIS PD SHOULD FEATURE MAINLY FAIR/DRY WEATHER WITH SFC
HIGH PRES IN CONTROL. RISING HEIGHTS AND GRADUAL RETURN FLOW WILL
LKLY ALLOW FOR A MODERATION IN TEMPS BACK TO AT LEAST SEASONAL
NORMALS...IF NOT ABOVE NORMAL.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
ADVANCING BAND OF SHOWERS NOW ENCROACHING FROM THE WEST...WITH THE
LEADING EDGE OF THE ACTIVITY JUST THROUGH KERI AT 09Z. OVERALL...VFR
CONDITIONS CONTINUE ACROSS MOST OF CENTRAL PA ATTM. THE EXCEPTION
IS ACROSS THE MIDDLE AND LOWER SUSQUEHANNA VALLEY WHERE MVFR TO
LOCALLY IFR CONDITIONS NOW EXIST IN FOG. EXPECT THIS TO CONTINUE
THROUGH 14Z-15Z AS THICKENING CLOUDS MAY RETARD FOG DISSIPATION.
APPROACHING FRONT WILL SWEEP A CORRIDOR OF PRECIPITATION ACROSS
REGION TODAY. SHOWERS WILL AFFECT KBFD FIRST...AROUND 11Z. EXPECT
CIGS HERE TO QUICKLY DROP TO MVFR LEVELS AS PRECIPITATION BEGINS.
PRECIPITATION WILL ACROSS CENTRAL SECTIONS BY LATE MORNING...AND
FINALLY INTO SOUTHEAST AREAS BY LATER IN THE AFTERNOON. IN
ADDITION THERE WILL BE SOME TSRA DEVELOPING IN THE SHRA ACTIVITY.
AS FOR PRECIPITATION COVERAGE...MOST EXTENSIVE WILL LIKELY BE IN
THE MORNING HOURS IN THE WEST...WITH ACTIVITY BECOMING MORE
CELLULAR AND CONVECTIVE IN NATURE DURING THE AFTERNOON. FOR THIS
REASON MENTIONED CATEGORICAL SHRA IN KBFD AND KJST...WITH JUST
VCSH IN OTHER TAFS.
QUESTION ALSO IS EXTENT OF TSRA ACTIVITY. ATTM...KEPT VCTS OUT OF
TAFS...WITH THE IDEA THAT IF MORE ORGANIZED ACTIVITY DEVELOPS LATER
TODAY WILL INCLUDE IN SUBSEQUENT ISSUANCES. ALTHOUGH NOT MENTIONED
IN TAFS ATTM...AVIATION INTERESTS SHOULD EXPECT AT LEAST SCATTERED
TSRA DURING THE AFTERNOON OVER CENTRAL AND EASTERN AREAS OF CENTRAL
PA.
COLD ADVECTION AND CYCLONIC FLOW ALOFT COUPLED WITH LOW LEVEL
MOISTURE LEFT OVER FROM TODAYS PRECIPITATION WILL LIKELY SPELL SOME
OVERNIGHT STRATUS AND FOG FRIDAY NIGHT WITH MVFR CONDITIONS...AND
SOME IFR IN THE NORTHERN AND WESTERN MOUNTAINS.
DRIER AND COOLER AIR WORKS IN FOR THE WEEKEND...AND EARLY NEXT WEEK.
OUTLOOK...
SAT-TUE...MAINLY VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...STEINBUGL
AVIATION...JUNG
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1019 AM CDT FRI AUG 17 2012
.UPDATE...
AS OF 10 AM...SKIES ACROSS THE MIDSOUTH WERE MOSTLY CLOUDY. AN
AREA OF SHOWERS AND A FEW THUNDERSTORMS WAS MOVING ACROSS
NORTHEASTERN ARKANSAS INTO WEST TENNESSEE AND NORTHWEST
MISSISSIPPI. THESE SHOWERS AND STORMS HAVE DEVELOPED AHEAD OF A
SHORTWAVE THAT WAS VISIBLE ON RADAR. IT IS INTERESTING TO NOTE THE
LACK OF ACTIVITY BEHIND THE SHORTWAVE. TEMPERATURES ACROSS THE
REGION RANGED FROM THE LOWER TO UPPER 70S.
WITH THE SHOWERS AND THUNDERSTORMS THAT OCCURRED LAST NIGHT AND
THE ACTIVITY MOVING THROUGH NOW...THE SEVERE WEATHER CHANCES
WOULD SEEM TO BE LOWER FOR THIS AFTERNOON. HOWEVER...THERE ARE
BREAKS IN THE CLOUDS ACROSS CENTRAL ARKANSAS AND CENTRAL
MISSISSIPPI AND TEMPERATURES HAVE JUMPED INTO THE UPPER 70S TO
LOW 80S. IF THE CLOUDS BEGIN TO BREAK UP ACROSS THE MIDSOUTH...
THEN TEMPERATURES WILL GO UP AND SO WILL THE INSTABILITY FOR
POTENTIAL STRONG TO SEVERE THUNDERSTORMS THIS AFTERNOON. THE
LATEST NAM GUIDANCE SUGGESTS THESE SHOWERS AND THUNDERSTORMS
CURRENTLY IN NORTHEAST ARKANSAS WILL CONTINUE MOVING ACROSS THE
MIDSOUTH. THE LATEST NAM ALSO SUGGESTS STORMS RE-FIRING ALONG THE
COLD FRONT IN WEST TENNESSEE AND NORTHEAST ARKANSAS THIS MORNING.
IT IS SOMEWHAT HARD TO BELIEVE THIS SCENARIO AT THIS POINT WITH
THE DENSE OVERCAST ACROSS THE REGION. FOR THE TIME BEING...THE
FORECAST HAS BEEN LEFT UNTOUCHED. THE POTENTIAL FOR STRONG TO
SEVERE STORMS THIS AFTERNOON ACROSS NORTH MISSISSIPPI IS HEAVILY
DEPENDENT ON THE CLOUD COVER AND STABILITY OF THE ATMOSPHERE IN
THE WAKE OF PREVIOUS AND ONGOING CONVECTION.
RRH
&&
.PREV DISCUSSION... /ISSUED 621 AM CDT FRI AUG 17 2012/
DISCUSSION... /ISSUED 505 AM CDT FRI AUG 17 2012/
LINEAR THUNDERSTORM COMPLEX THAT DROPPED THROUGH THE MIDSOUTH
EARLY THIS MORNING WAS MOVING INTO CENTRAL MS AND WEST CENTRAL AL
AT DISCUSSION TIME. THIS STORM COMPLEX OCCURRED AHEAD OF A HEIGHT
FALLS SPREADING INTO THE MID MS RIVER VALLEY... AND HAD PROPAGATED
SOUTHWARD INTO MODERATE INSTABILITY OVER THE MIDSOUTH ONCE IT HAD
AN ESTABLISHED COLD POOL.
ADDITIONAL SHOWERS AND THUNDERSTORMS OVER NORTHEAST AR HAVE FORMED
EARLY THIS MORNING...IN ADVANCE OF A WELL DEFINED MIDLEVEL
SHORTWAVE MOVING INTO WESTERN AR. ONCE THIS FEATURE PUSHES EAST...
NVA BEHIND THE SHORTWAVE AND THE INTRUSION OF DRIER AND MORE
STABLE LOW LEVEL AIR SHOULD LIMIT IF NOT END RAIN CHANCES NORTH
OF I40 THROUGH THE AFTERNOON. THE SURFACE COLD FRONT WILL PUSH
INTO CENTRAL MS BY MIDEVENING...WITH RAIN CHANCES TAPERING OFF
OVER NORTH MS.
AFTERNOON TEMPERATURES 5 TO 7 DEGREES BELOW MID/LATE AUGUST
NORMALS WILL PREVAIL INTO THE EARLY PART OF THE UPCOMING WORKWEEK. FEW
CHANGES HAVE BEEN MADE TO EARLIER FORECASTS... BUT HAVE INTRODUCED
LOW END RAIN CHANCES FOR SUNDAY...MAINLY SOUTH AND WEST OF
MEMPHIS. NAM/GFS/ECMWF MODELS SHOW A NORTHWEST FLOW SHORTWAVE
DROPPING INTO THE ARKLAMISS REGION...WHERE PRECIPITABLE WATER
VALUES OF 2 INCHES WILL BE COMMON. LESS AVAILABLE MOISTURE WILL
BE AVAILABLE OVER THE MIDSOUTH. PRIMARY IMPACT MAY JUST BE
INCREASED MIDLEVEL CLOUDINESS IN MOST AREAS.
LOOKING TO THE OUTER PERIODS... GFS...CMC AND ECMWF MODELS SHOW
NORTHWEST FLOW REPLACED BY A BROAD UPPER LEVEL HEIGHT RIDGE OVER
THE SOUTHERN U.S.. ECMWF DEVELOPS A WEAK CUTOFF LOW OVER THE
LOWER/MID MS RIVER VALLEY IN THE MID TO LATE WEEK... BUT THIS IS
NOT CORROBORATED BY THE GFS OR CMC MODELS. HAVE KEPT THE EXTENDED
PERIODS MAINLY DRY...WITH NEAR TO SLIGHTLY ABOVE NORMAL TEMPS.
PWB
AVIATION...
12Z TAF SET
NEXT ROUND OF SHOWERS AND THUNDERSTORMS BEGINNING TO PUSH INTO
EASTERN ARKANSAS AT THIS TIME. HAVE THROWN IN A TEMPO AT KJBR THROUGH
14Z FOR LOWER VSBYS AND CIGS AND TO MENTION TSRA. HAVE ALSO
INTRODUCED A TEMPO AT KMEM THROUGH 15Z BUT WILL ONLY MENTION SHRA
AS LINE SHOULD WEAKEN AS IT PUSHES SOUTHEAST. EXPECT AREA TO
DISSIPATE OVER NORTHWEST MISSISSIPPI AROUND 15Z. LATEST HRRR MODEL
INDICATES REDEVELOPMENT WILL OCCUR ALONG OLD OUTFLOW BOUNDARIES
SOUTH AND SOUTHWEST OF KMEM. HAVE MENTION OF VCTS AT KMEM
BEGINNING AT 19Z WHILE MENTION OF KTUP BEGINS AT 20Z. BY
00-01Z...EXPECT SHRA/TSRA ACTIVITY TO BEGIN DISSIPATING.
OTHERWISE...VFR CONDITIONS EXPECTED. NORTHERLY WINDS AROUND 5-10
KTS EXPECTED TODAY.
KRM
&&
.AVIATION...
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 86 64 83 65 / 50 10 10 10
MKL 83 59 81 57 / 50 10 10 10
JBR 81 61 81 62 / 40 10 10 20
TUP 86 66 85 65 / 80 30 10 10
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
621 AM CDT FRI AUG 17 2012
.DISCUSSION... /ISSUED 505 AM CDT FRI AUG 17 2012/
LINEAR THUNDERSTORM COMPLEX THAT DROPPED THROUGH THE MIDSOUTH
EARLY THIS MORNING WAS MOVING INTO CENTRAL MS AND WEST CENTRAL AL
AT DISCUSSION TIME. THIS STORM COMPLEX OCCURRED AHEAD OF A HEIGHT
FALLS SPREADING INTO THE MID MS RIVER VALLEY... AND HAD PROPAGATED
SOUTHWARD INTO MODERATE INSTABILITY OVER THE MIDSOUTH ONCE IT HAD
AN ESTABLISHED COLD POOL.
ADDITIONAL SHOWERS AND THUNDERSTORMS OVER NORTHEAST AR HAVE FORMED
EARLY THIS MORNING...IN ADVANCE OF A WELL DEFINED MIDLEVEL
SHORTWAVE MOVING INTO WESTERN AR. ONCE THIS FEATURE PUSHES EAST...
NVA BEHIND THE SHORTWAVE AND THE INTRUSION OF DRIER AND MORE
STABLE LOW LEVEL AIR SHOULD LIMIT IF NOT END RAIN CHANCES NORTH
OF I40 THROUGH THE AFTERNOON. THE SURFACE COLD FRONT WILL PUSH
INTO CENTRAL MS BY MIDEVENING...WITH RAIN CHANCES TAPERING OFF
OVER NORTH MS.
AFTERNOON TEMPERATURES 5 TO 7 DEGREES BELOW MID/LATE AUGUST
NORMALS WILL PREVAIL INTO THE EARLY PART OF THE UPCOMING WORKWEEK. FEW
CHANGES HAVE BEEN MADE TO EARLIER FORECASTS... BUT HAVE INTRODUCED
LOW END RAIN CHANCES FOR SUNDAY...MAINLY SOUTH AND WEST OF
MEMPHIS. NAM/GFS/ECMWF MODELS SHOW A NORTHWEST FLOW SHORTWAVE
DROPPING INTO THE ARKLAMISS REGION...WHERE PRECIPITABLE WATER
VALUES OF 2 INCHES WILL BE COMMON. LESS AVAILABLE MOISTURE WILL
BE AVAILABLE OVER THE MIDSOUTH. PRIMARY IMPACT MAY JUST BE
INCREASED MIDLEVEL CLOUDINESS IN MOST AREAS.
LOOKING TO THE OUTER PERIODS... GFS...CMC AND ECMWF MODELS SHOW
NORTHWEST FLOW REPLACED BY A BROAD UPPER LEVEL HEIGHT RIDGE OVER
THE SOUTHERN U.S.. ECMWF DEVELOPS A WEAK CUTOFF LOW OVER THE
LOWER/MID MS RIVER VALLEY IN THE MID TO LATE WEEK... BUT THIS IS
NOT CORROBORATED BY THE GFS OR CMC MODELS. HAVE KEPT THE EXTENDED
PERIODS MAINLY DRY...WITH NEAR TO SLIGHTLY ABOVE NORMAL TEMPS.
PWB
&&
.AVIATION...
12Z TAF SET
NEXT ROUND OF SHOWERS AND THUNDERSTORMS BEGINNING TO PUSH INTO
EASTERN ARKANSAS AT THIS TIME. HAVE THROWN IN A TEMPO AT KJBR THROUGH
14Z FOR LOWER VSBYS AND CIGS AND TO MENTION TSRA. HAVE ALSO
INTRODUCED A TEMPO AT KMEM THROUGH 15Z BUT WILL ONLY MENTION SHRA
AS LINE SHOULD WEAKEN AS IT PUSHES SOUTHEAST. EXPECT AREA TO
DISSIPATE OVER NORTHWEST MISSISSIPPI AROUND 15Z. LATEST HRRR MODEL
INDICATES REDEVELOPMENT WILL OCCUR ALONG OLD OUTFLOW BOUNDARIES
SOUTH AND SOUTHWEST OF KMEM. HAVE MENTION OF VCTS AT KMEM
BEGINNING AT 19Z WHILE MENTION OF KTUP BEGINS AT 20Z. BY
00-01Z...EXPECT SHRA/TSRA ACTIVITY TO BEGIN DISSIPATING.
OTHERWISE...VFR CONDITIONS EXPECTED. NORTHERLY WINDS ARPUND 5-10
KTS EXPECTED TODAY.
KRM
&&
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 86 64 83 65 / 70 10 10 10
MKL 83 59 81 57 / 50 10 10 10
JBR 81 61 81 62 / 40 10 10 20
TUP 86 66 85 65 / 90 30 10 10
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
637 AM CDT FRI AUG 17 2012
.UPDATE...
SEE 12Z AVIATION DISCUSSION BELOW.
&&
.AVIATION...
VFR CONDITIONS SHOULD PREVAIL ACROSS WEST CENTRAL TEXAS TERMINALS
WELL INTO THE AFTERNOON...BEFORE THUNDERSTORMS BEGIN TO DEVELOP
AND CONDITIONS MAY DETERIORATE. MOST LIKELY LOCATION FOR STORMS
WILL BE ACROSS THE BIC COUNTRY...AND HAVE ADDED A VCTS FOR THE
KABI TERMINAL FOR NOW. FARTHER SOUTH...JUST TOO MUCH UNCERTAINTY
ON TIMING AND PLACEMENT OF STORM TO WARRANT A MENTION...BUT
CONDITIONS WILL CERTAINLY NEED TO BE MONITORED.
&&
.PREV DISCUSSION... /ISSUED 406 AM CDT FRI AUG 17 2012/
SHORT TERM...
SCATTERED MID LEVEL SHOWERS CONTINUE TO DEVELOP ACROSS PORTIONS OF
THE BIG COUNTRY AND RED RIVER VALLEY EARLY THIS MORNING. ABUNDANT
MID LEVEL MOISTURE COMBINING WITH A LOW LEVEL JET OF 25 TO 30 KTS.
ITS ABOUT THIS TIME THAT CONVECTION EXPANDED YESTERDAY...AND EVEN
WITHOUT THE STRONGER SHORTWAVE THAT WE HAD PASSING...WOULD NOT BE
SURPRISED TO SEE CONVECTIVE COVERAGE EXPAND A LITTLE MORE AT SUNRISE
THIS MORNING AS WELL.
SURFACE FRONTAL BOUNDARY DROPPING THROUGH OKLAHOMA THIS
MORNING...AND SEEMS TO HAVE A DECENT PUSH WITH IT SO FAR.
OBSERVATIONS ARE SHOWING SOME 15 TO 20 KT NORTHEAST WINDS....WITH
DEWPOINTS IN THE 40S AND LOWER 50S. LATEST RUC AS WELL AS THE 4KM
WRF MODEL FROM TEXAS TECH...SHOW THIS BOUNDARY MAKING IT WELL INTO
WEST CENTRAL TEXAS TODAY. IF THIS DOES HAPPEN...THEN CONVECTION WILL
END UP FARTHER SOUTH THAN WE ORIGINALLY THOUGHT. THUS...HAVE BOOSTED
THE POPS ACROSS THE CENTRAL COUNTIES...ROUGHLY BETWEEN ABILENE AND
SAN ANGELO...A LITTLE. THIS ACTIVITY WILL CONTINUE INTO THE
EVENING HOURS.
TONIGHT...MODELS SHOW A STRONGER SHORTWAVE MOVING TOWARDS WEST
CENTRAL TEXAS IN THE NORTHWEST FLOW ALOFT. COMBINE THIS WAVE WITH
WHATS LEFT OF THE SURFACE BOUNDARY...AND EXPECT SCATTERED CONVECTION
TO CONTINUE. WITH THE LOW LEVEL JET STRONGER TONIGHT...BEST POPS
WILL SHIFT A LITTLE TO NORTH OF THE BOUNDARY.
LONG TERM...
LOOKS LIKE A WET PATTERN SETTING UP THIS WEEKEND ACROSS WEST CENTRAL
TEXAS. BENEFICIAL RAINFALL IS NEEDED AS MUCH OF THE CWFA IS
CURRENTLY EXPERIENCING MODERATE TO SEVERE DROUGHT CONDITIONS(AS OF
AUGUST 14)...ACCORDING TO THE US DROUGHT MONITOR. THE MAIN PLAYERS
WILL BE A SLOW MOVING COOL FRONT...OTHER MESOSCALE BOUNDARIES IN THE
AREA AND WEAK UPPER LEVEL FORCING. ALSO...SLOW MOVING STORMS AND
PWAT VALUES OF 1.5 TO 2 INCHES WILL BRING LOCALLY HEAVY RAINFALL.
LOOKS LIKE RAINFALL AMOUNTS WILL AVERAGE 0.5 TO 1.5 INCHES...WITH
LOCALLY HIGHER AMOUNTS POSSIBLE...ESPECIALLY ACROSS THE NORTHERN AND
EASTERN CWFA. ALSO...AN ISOLATED SEVERE STORM OR TWO ARE POSSIBLE
ACROSS THE BIG COUNTRY MAINLY SATURDAY AFTERNOON AND EVENING. THE
MAIN HAZARDS WILL BE LARGE HAIL AND DAMAGING WINDS. THE ABUNDANT
CLOUD COVER AND RAINFALL WILL KEEP TEMPERATURES DOWN SATURDAY AND
SUNDAY. HIGHS WILL BE IN THE UPPER 80S TO MID 90S.
LOOKS LIKE MAINLY DRY WEATHER RETURNING NEXT WEEK AS THE UPPER LEVEL
RIDGE BUILDS BACK OVER THE AREA. THE GFS MODEL IS STILL INDICATING A
POSSIBLE MCS MOVING SOUTHEAST ACROSS THE SOUTHERN PLAINS MONDAY
NIGHT AND TUESDAY MORNING. WILL KEEP THE FORECAST DRY FOR
NOW...HOWEVER WILL NEED TO MONITOR FUTURE MODEL OUTPUT. HIGHS WILL
WARM BACK INTO THE MID 90S EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 95 72 94 71 90 / 40 40 50 50 40
SAN ANGELO 100 75 95 71 92 / 20 30 40 40 30
JUNCTION 96 74 96 72 94 / 10 20 30 30 30
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
07
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
950 AM EDT FRI AUG 17 2012
.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION TODAY ACCOMPANIED BY SHOWERS
AND THUNDERSTORMS DURING THE AFTERNOON AND EVENING. DEEPENING LOW
PRESSURE...ANCHORED OVER SOUTHEAST CANADA...WILL EVOLVE ACROSS THE
EASTERN U.S. FOR THE WEEKEND INTO THE FIRST HALF OF NEXT WEEK. A
SERIES OF DISTURBANCES EMBEDDED WITHIN THE UPPER LOW WILL KEEP
UNSETTLED...SHOWERY...CLOUDY...COOL CONDITIONS ACROSS MUCH OF THE
AREA UNTIL TUESDAY...WHEN DRIER CONDITIONS ALONG WITH SEASONABLE
TEMPERATURES ARE EXPECTED.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 940 AM EDT FRIDAY...
LOW CLOUDS AND FOG ARE LIFTING AS HIGH CLOUDS SPREAD EAST INTO OUR
REGION. EXPECT SUFFICIENT HEATING COMBINED WITH LOW-LEVEL MOISTURE
INCREASE TO SUPPORT SCATTERED SHOWERS AND THUNDERSTORMS THIS AFTERNOON
INTO TONIGHT. SWODY1 HAS KEPT WESTERN PORTIONS OF CWA IN SLIGHT
RISK OF SEVERE FOR THIS AFTERNOON. THE MAIN THREAT IS FOR DAMAGING
WINDS. HRRR AND WRF-ARWRNK SHOWED CONVECTION STARTING AFTER 19Z
AND MOVES EAST INTO TONIGHT. MODIFIED CLOUD COVER AND POPS FOR
THIS MORNING INTO THIS AFTERNOON. ADJUSTED TEMPERATURES ACCORDING
TO LATEST OBS AND MODEL TRENDS. MADE A LITTLE COOLER IN THE WEST
WITH ADDITIONAL LOW CLOUDS THIS MORNING.
AS OF 500 AM EDT FRIDAY...
MAIN CONCERN THROUGH THE SHORT TERM WILL BE APPROACHING SHORT
WAVE...NOW LOCATED FROM THE EASTERN GREAT LAKES SWWD INTO OK/MO.
AN OVERNIGHT MCS ASSOCIATED WITH THIS TROUGH BACKBUILT
SOUTHWESTWARD INTO THE MID-SOUTH/LOWER MS VALLEY REGION...WITH
LITTLE TO NO ACTIVITY CURRENT EVIDENT FURTHER NORTH ACROSS THE OH
VALLEY. THIS SHORT WAVE WILL PROGRESS TOWARD THE MID-ATLANTIC BY
00Z AND EVOLVE INTO A DEEPENING AREA OF SEMI-PERMANENT UPPER LOW
PRESSURE ALOFT ACROSS SOUTHEAST CANADA THROUGH THE WEEKEND AND
INTO EARLY NEXT WEEK. IN SO DOING...DYNAMICS WILL WEAKEN AS THE
SYSTEM PROGRESSES TOWARD THE EAST COAST. EXTENSIVE MID-HIGH CLOUDS
HAVE SPREAD EASTWARD ACROSS THE OH VALLEY INTO PARTS OF WV EARLY
THIS MORNING...BUT THE LACK OF UPSTREAM CONVECTION SUPPORTS
CURRENT THINKING THAT ANTECEDENT CLOUD COVER ACROSS OUR CWA WILL
BE LIMITED ENOUGH TO ALLOW SUFFICIENT HEATING COMBINED WITH A SLOW
LOW-LEVEL MOISTURE INCREASE TO SUPPORT SCT SHRA/TSRA BY MID-DAY
THROUGH THE EVENING FROM W-E. SPC HAS OUTLOOKED THE ENTIRE CWA FOR
SLIGHT RISK FOR MULTI-CELL TSRA WITH SPOTTY MARGINAL HAIL AND
DAMAGING WINDS. MODEL PROGGED INSTABILITY IS WEAK AT BEST AND SHEAR
IS NIL...SO LOCAL THINKING IS THAT A 5 PERCENT RISK OF SEVERE MAY
BE SUFFICIENT TO COVER EXPECTED CONVECTIVE ACTIVITY TODAY. CERTAINLY
CANNOT RULE OUT A WARNING OR TWO DURING THE AFTERNOON/EARLY
EVENING...ESPECIALLY ACROSS THE SOUTHERN SHENANDOAH VALLEY...FAR
SOUTHWEST VA...AND NORTHERN PIEDMONT REGION. ACTIVITY SHOULD WANE
RATHER QUICKLY AFT 00Z AS THE UPPER SHORT WAVE SHEARS OUT AND THE
MAIN DYNAMICS MOVE TOWARD NEW ENGLAND. ALTHOUGH SHRA/TSRA ACTIVITY
SHOULD GENERALLY DISSIPATE ACROSS E/SE SECTIONS OF THE CWA AFT
06Z...EMBEDDED UPSTREAM SHORT WAVES...PARTICULARLY ONE POISED
ACROSS THE UPPER MIDWEST/NORTHERN PLAINS OVERNIGHT...WILL PROLONG
SW FLOW ALOFT AND DELAY ANY CLEARING DURING THE REMAINDER OF THE
NEAR TERM.
MAX TEMPS TODAY WILL BE PROBLEMATIC AND COULD EASILY VARY BY AS
MUCH AS 20F OR MORE FROM THE WV SIDE OF THE CWA TO THE SE PIEDMONT
REGION. EXTENSIVE MID-HIGH CLOUDS SHOULD SPREAD ACROSS AREAS
ALONG-W OF THE ALLEGHANYS EARLY ENOUGH IN THE DAY TO GREATLY LIMIT
DAYTIME HEATING ACROSS THOSE AREAS...WITH SHRA/TSRA DEVELOPING
WEST OF A ROA-HLX-HKY LINE BY 18Z. EAST OF THIS AREA...CLOUDS WILL
BE SLOWER TO ARRIVE WITH INITIAL SFC MOISTURE LIMITING EARLY CU
DEVELOPMENT. WITH 850MB TEMPS NEAR +18C BY AFTERNOON...ALBEIT 2C
COOLER THAN INDICATED ACROSS THAT REGION YESTERDAY...AREAS FROM
LYH-DAN EASTWARD COULD EASILY APPROACH 90 BY AFTERNOON.
THUS...HAVE MAX TEMPS RANGING FROM THE MID 70S SE WV TO AROUND DAN
AND POINTS EASTWARD. RADIATIONAL COOLING OVERNIGHT WILL BE MINIMAL
TO NONE WITH EXTENSIVE CLOUD COVER REMAINING IN PLACE. DEWPOINTS
WILL REMAIN IN THE 60S TO EVEN NEAR 70 ACROSS THE SE PIEDMONT
REGION. THUS...EXPECT MIN TEMPS TO GENERALLY BE AOA THIS MORNINGS
READINGS WITH LESS VARIATION NOTED...RANGING FROM THE LOW 60S
MOUNTAINS/SE WV TO NEAR 70 DAN AND POINTS EASTWARD.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 430 AM THURSDAY...
ALTHOUGH THE COLD FRONT WILL REMAIN ACROSS NORTH CAROLINA FOR MOST
OF THE WEEKEND...ENOUGH MOISTURE WILL COMBINE WITH WEAK UPPER LEVEL
DISTURBANCES AND SURFACE WIND CONVERGENCE TO PRODUCE SHOWERS AND A
FEW STORMS MOSTLY SOUTH OF RT 460...THROUGH THE PERIOD. TEMPS WILL
BE NOTICEABLY COOLER AND ATTM SUNDAY SEEMS TO HAVE THE MOST COVERAGE
OF SHOWERS ROUGHLY FROM TNB TO HLX. H85 TEMPS FROM +12C TO +14C WITH
CLOUDS AND OFF ON AND SHOWERS SHOULD PUT MAX T IN THE MIDDLE 70S TO
LOWER 80S ACROSS THE CWA.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 350 PM THURSDAY...
UPPER LEVEL TROF GRADUALLY FILLS DURING THE WEEK WITH MODERATING
HEIGHTS AND THICKNESSES. THIS SHOULD RESULT IN GRADUAL RETURN OF
SOUTHERLY LOW LEVEL FLOW...AND A MORE DIURNALLY DRIVEN CONVECTIVE
REGIME WITH DAYTIME CU AND NIGHTTIME CLEARING. ANY PRECIP THREAT
WOULD BE MAINLY CONFINED TO THE PEAK HEATING PART OF THE DAY AND
PRIMARILY CONFINED TO THE MTNS WHERE LOW LEVEL CONVERGENCE WOULD
BE GREATEST. TEMPERATURES ARE EXPECTED TO BE THE COOLEST EARLY IN
THE WEEK...5 DEG BLOW NORM...THEN TREND CLOSER TO NORMAL FOR MID
WEEK.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
AS OF 740 AM EDT FRIDAY...
IMMEDIATE CONCERN IS LOCALIZED POCKETS OF IFR-LIFR CIGS/VSBYS IN FG
AT THE USUAL SPOTS...NAMELY LWB AND BCB. THIS SHOULD DISSIPATE
QUICKLY...BUT MAY HANG ON FOR A LITTLE WHILE AT LWB BECAUSE OF
REDUCED INSOLATION FROM INCREASING HIGH CLOUDS. WILL NEED TO WATCH
FOR DEVELOPMENT OF MVFR CIGS BLF-LWB AS WELL AS FOG LIFTS INTO
STRATUS DECK. STRATUS ALREADY EVIDENT JUST TO THE WEST OF BLF. AS
NOTED BEFORE...MAIN FOCUS FOR TAF VALID PERIOD IS CHANCE FOR
CONVECTION THIS AFTERNOON/EVENING. NEW CONCERN IS WHETHER OR NOT
CLOUDS/PCPN WILL EXIT THE AREA...OR BUILD BACK NORTHWARD OVERNIGHT
IN WAKE OF INITIAL WAVE OF SHRA/TSRA. NO CHANGES AT THIS TIME TO
EARLIER INDICATED CONVECTIVE TIMING...MAINLY 18Z LWB-BLF TO 00Z
LYH-DAN. BIGGEST CHANGE WAS TO ADD MVFR CIGS AND MVFR-IFR VSBYS IN
-RA/-SHRA/-DZ AFT 08Z. THINKING IS THAT -SHRA WILL GENERALLY BE
CONFINED TO PIEDMONT REGION...BUT UPSLOPE FLOW AND PASSING WAVE
ALONG FRONT TO THE SOUTH COULD PROMOTE DEVELOPMENT OF LOW CLOUDS AND
-DZ BLF-LWB AFT 08Z SAT. WINDS REMAIN W-NW THROUGH TAF VALID
PERIOD...BUT WILL BE VEERING OVER TO NE NEAR 12Z SAT...WHICH WILL
FURTHER PROMOTE DEVELOPMENT OF LOW CLOUDS AND FOG...ESPECIALLY
ACROSS THE PIEDMONT REGION.
AS OF 200 AM EDT FRIDAY...
MAIN CONCERN THROUGH TAF VALID PERIOD WILL BE APPROACHING/DEEPENING
UPPER TROUGH AND ASSOCIATED FRONTAL SYSTEM. VFR CONDITIONS IN PLACE
ACROSS THE CWA AT THIS HOUR WITH CONSIDERABLY LESS FOG EVIDENT THAN
AT THIS TIME YESTERDAY...LARGELY THANKS TO EXPANDING AREA OF HIGH
CLOUDS AS EXPECTED. NONETHELESS...SEVERAL HOURS OF MVFR CAN BE
EXPECTED AT BCB/LWB FOR SURE THROUGH 13Z...BUT ANY IFR CONDITIONS
SHOULD BE BRIEF/ISOLD. MODELS IN GENERAL AGREEMENT WITH RESPECT TO
TIMING OF CONVECTION. EXPECT CONVECTION TO DEVELOP LWB-BLF IN THE
18Z TIME FRAME...THEN SPREAD EAST TOWARD THE PIEDMONT BY 00Z.
GENERALLY MVFR CIGS/VSBYS EXPECTED WITH SHRA/TSRA...WITH ISOLD/BRIEF
IFR CONDITIONS TOO UNCERTAIN TO PUT IN PREVAILING OR TEMPO GROUPS AT
THIS TIME. WINDS WILL REMAIN WSW-WNW THROUGH TAF VALID PERIOD...WITH
SPEEDS REMAINING LESS THAN 10KTS.
EXTENDED AVIATION DISCUSSION...
THE FRONT SLOWS AND LINGERS ACROSS THE CAROLINAS THROUGH THE
WEEKEND...WHILE HIGH PRESSURE PASSES EASTWARD TO THE SOUTH OF THE
GREAT LAKES. EXPECT MOST OF THE AREA TO REMAIN DRY ON
SATURDAY...HOWEVER WIDELY SCATTERED SHOWERS AND THUNDERSTORMS WILL
DEVELOP MAINLY ACROSS THE MOUNTAINS WITH AFTERNOON HEATING FROM
SUNDAY INTO THE MIDDLE OF NEXT WEEK.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...KK/RAB
NEAR TERM...RAB
SHORT TERM...KM
LONG TERM...PM
AVIATION...RAB
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
503 PM EDT FRI AUG 17 2012
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL MOVE INTO THE FORECAST AREA TONIGHT
AND STALL. THE FRONT WILL REMAIN NEAR THE AREA THROUGH MONDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
LATE THIS AFTERNOON...
SHOWERS AND THUNDERSTORMS HAVE INCREASED OVER THE AREA AHEAD OF
AN ADVANCING COLD FRONT. SOME STORMS HAVE BECOME SEVERE. MSAS
CAPES WERE 2000-3000 J/KG WHILE LIS WERE -6. WITH AFTERNOON
TEMPERATURES IN THE UPPER 80S TO LOWER 90S...LOW LEVEL LAPSE RATES
WERE STRONG. AS THE SUN BEGINS TO GO DOWN...THE SURFACE HEATING
WILL DECREASE AND THE ATMOSPHERE WILL BE NOT AS UNSTABLE.
THEREFORE...THE STORMS WILL NOT BE AS STRONG BY EVENING.
TONIGHT...
A FURTHER INCREASE IN MOISTURE AND CONVERGENCE AHEAD OF THE FRONT
SHOULD SUPPORT GREATER THUNDERSTORM COVERAGE TONIGHT UNLESS
WIDESPREAD CONVECTION DEVELOPS DURING THE LATE AFTERNOON RELEASING
MUCH OF THE INSTABILITY. THE LATEST HIGH-RESOLUTION WRF SHOWS THE
GREATEST COVERAGE DURING THE 800 PM TO 1000 PM TIME FRAME. THIS
MAY BE CORRECT BECAUSE BOTH THE NAM AND GFS PLUS RAP SHOW A MID-
LEVEL SHORTWAVE TROUGH MOVING INTO THE AREA DURING THE EVENING.
THUNDERSTORMS MAY CONTINUE OVERNIGHT BUT THE CHANCE SHOULD
DIMINISH BECAUSE OF DIURNAL COOLING AND PREVIOUS CONVECTION. THE
TEMPERATURE GUIDANCE TONIGHT MAY BE A LITTLE TOO COOL BECAUSE OF
CLOUDINESS AND MIXING ASSOCIATED WITH THE FRONT.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
THE NAM AND GFS KEEP THE SURFACE FRONT IN THE FORECAST AREA THOUGH
SUNDAY. CONVERGENCE ASSOCIATED WITH THE FRONT SUPPORT THUNDERSTORMS.
THE MODELS SHOW MOISTURE BECOMING SOMEWHAT SHALLOW BEHIND A LEAD
MID-LEVEL SHORTWAVE TROUGH TONIGHT. THE NAM AND GFS MOS ARE
CONSISTENT WITH CHANCE POP SATURDAY THROUGH SUNDAY. THE NAM MOS
INDICATED COOLER HIGH TEMPERATURES COMPARED THE GFS MOS. BOTH THE
NAM AND GFS SHOWED H85 WESTERLY FLOW SO EXPECT BREAKS IN THE
CLOUDINESS SUPPORTING WARMER TEMPERATURES. BELIEVE THE GUIDANCE
CONSENSUS IS THE BEST FORECAST AT THIS TIME.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
THE GFS AND ECMWF GENERALLY KEEP THE FRONT NEAR THE FORECAST AREA
DURING THE EXTENDED PERIOD. THE MODELS INDICATE UPPER-LEVEL
TROUGHING BUT ARE NOT IN GOOD AGREEMENT WITH THE TIMING AND
PLACEMENT OF THE TROUGH AND DEEPER MOISTURE. THE GFS ENSEMBLE
GUIDANCE INDICATES THE GREATER SHOWER CHANCE MONDAY THROUGH
WEDNESDAY WITH THE MEAN POPS AROUND 40 PERCENT. THE ENSEMBLE MEAN
POPS LOWER TO 20 TO 30 PERCENT THURSDAY AND FRIDAY. HOWEVER...THE
ECMWF INDICATES THE DEEPEST MOISTURE THURSDAY AND FRIDAY. LEANED
TOWARD THE ENSEMBLE MEANS FOR THE POP FORECAST.
&&
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
A WEAK SHORT WAVE IS MOVING EAST THROUGH THE AREA THIS AFTERNOON.
THIS ALONG WITH AN UNSTABLE ATMOSPHERE IS AIDING IN THE DEVELOPMENT
OF SHOWERS AND THUNDERSTORMS WITH SOME STRONG TO SEVERE THUNDERSTORMS.
MSAS CAPES WERE 2000-3000 J/KG WITH LIS -6. OUTSIDE OF CONVECTIVE
ACTIVITY...HAVE VFR CONDITIONS. BUT AS SHOWERS AND STORMS MOVE IN...
HAVE INCLUDED TEMPO GROUPS FOR 1-2 HOURS FOR THUNDERSTORMS WITH IFR
CONDITIONS. AS THE SUN GOES DOWN...THE SURFACE HEATING WILL LESSEN
AND THE AIRMASS WILL NOT BE AS UNSTABLE. SO THE THREAT OF STRONG
STORMS WILL DIMINISH AROUND 02Z-03Z. EXPECT MAINLY VFR CONDITIONS
OVERNIGHT AS DEBRIS CLOUDS FROM CONVECTIVE ACTIVITY EXPECTED TO
LINGER MUCH OF THE NIGHT.
EXTENDED AVIATION OUTLOOK...A CHANCE OF SHOWERS AND
THUNDERSTORMS...ALONG WITH A CHANCE OF LATE NIGHT/EARLY MORNING
RESTRICTIONS TO CIGS/VSBYS...AT TIMES THROUGH THE PERIOD.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
07
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
218 PM EDT FRI AUG 17 2012
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL MOVE INTO THE FORECAST AREA TONIGHT
AND STALL. THE FRONT WILL REMAIN NEAR THE AREA THROUGH MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THIS AFTERNOON...
A MOISTURE INCREASE AHEAD OF THE COLD FRONT HAS OCCURRED TODAY.
HEATING AND CONVERGENCE INTO THE PRE-FRONTAL TROUGH HAS RESULTED
IN SCATTERED THUNDERSTORMS THIS AFTERNOON. MODERATE INSTABILITY
AND A LARGE SURFACE TEMPERATURE-DEW POINT TEMPERATURE SPREAD
MAY HELP CAUSE DAMAGING WIND WITH A FEW OF THE THUNDERSTORMS.
TONIGHT...
A FURTHER INCREASE IN MOISTURE AND CONVERGENCE AHEAD OF THE FRONT
SHOULD SUPPORT GREATER THUNDERSTORM COVERAGE TONIGHT UNLESS
WIDESPREAD CONVECTION DEVELOPS DURING THE LATE AFTERNOON RELEASING
MUCH OF THE INSTABILITY. THE LATEST HIGH-RESOLUTION WRF SHOWS THE
GREATEST COVERAGE DURING THE 800 PM TO 1000 PM TIME FRAME. THIS
MAY BE CORRECT BECAUSE BOTH THE NAM AND GFS PLUS RAP SHOW A MID-
LEVEL SHORTWAVE TROUGH MOVING INTO THE AREA DURING THE EVENING.
THUNDERSTORMS MAY CONTINUE OVERNIGHT BUT THE CHANCE SHOULD
DIMINISH BECAUSE OF DIURNAL COOLING AND PREVIOUS CONVECTION. THE
TEMPERATURE GUIDANCE TONIGHT MAY BE A LITTLE TOO COOL BECAUSE OF
CLOUDINESS AND MIXING ASSOCIATED WITH THE FRONT.
&&
.SHORT TERM /SATURDAY/...
THE NAM AND GFS KEEP THE SURFACE FRONT IN THE FORECAST AREA THOUGH
SUNDAY. CONVERGENCE ASSOCIATED WITH THE FRONT SUPPORT THUNDERSTORMS.
THE MODELS SHOW MOISTURE BECOMING SOMEWHAT SHALLOW BEHIND A LEAD
MID-LEVEL SHORTWAVE TROUGH TONIGHT. THE NAM AND GFS MOS ARE
CONSISTENT WITH CHANCE POP SATURDAY THROUGH SUNDAY. THE NAM MOS
INDICATED COOLER HIGH TEMPERATURES COMPARED THE GFS MOS. BOTH THE
NAM AND GFS SHOWED H85 WESTERLY FLOW SO EXPECT BREAKS IN THE
CLOUDINESS SUPPORTING WARMER TEMPERATURES. BELIEVE THE GUIDANCE
CONSENSUS IS THE BEST FORECAST AT THIS TIME.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
THE GFS AND ECMWF GENERALLY KEEP THE FRONT NEAR THE FORECAST AREA
DURING THE EXTENDED PERIOD. THE MODELS INDICATE UPPER-LEVEL
TROUGHING BUT ARE NOT IN GOOD AGREEMENT WITH THE TIMING AND
PLACEMENT OF THE TROUGH AND DEEPER MOISTURE. THE GFS ENSEMBLE
GUIDANCE INDICATES THE GREATER SHOWER CHANCE MONDAY THROUGH
WEDNESDAY WITH THE MEAN POPS AROUND 40 PERCENT. THE ENSEMBLE MEAN
POPS LOWER TO 20 TO 30 PERCENT THURSDAY AND FRIDAY. HOWEVER...THE
ECMWF INDICATES THE DEEPEST MOISTURE THURSDAY AND FRIDAY. LEANED
TOWARD THE ENSEMBLE MEANS FOR THE POP FORECAST.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
CU HAS DEVELOPED RAPIDLY...WITH RADAR NOW INDICATING ISOLATED
DEVELOPING CONVECTIVE ACTIVITY NEAR CAE/CUB. LATEST MODELS
INDICATE CHANCE OF ADDITIONAL CONVECTION DEVELOPING LATER THIS
AFTERNOON AND EVENING. WILL CONCENTRATE ON THE NEAR TERM AND
MONITOR RADAR TRENDS FOR TS/PRECIP INCLUSION IN THE TAFS. WILL NOT
INDICATE FOG/STRATUS LATE TONIGHT/EARLY SATURDAY AT THIS TIME DUE
TO UNCERTAINTIES WITH REGARD TO OVERNIGHT CLOUD COVER.
EXTENDED AVIATION OUTLOOK...A CHANCE OF SHOWERS AND
THUNDERSTORMS...ALONG WITH A CHANCE OF LATE NIGHT/EARLY MORNING
RESTRICTIONS TO CIGS/VSBYS...AT TIMES THROUGH THE PERIOD.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON KY
146 PM EDT FRI AUG 17 2012
.UPDATE...
ISSUED AT 1235 PM EDT FRI AUG 17 2012
COLD FRONT SLOWLY PRESSING ACROSS THE STATE. AT 16Z FRONT EXTENDS
FROM JUST WEST OF FGX TO JUST EAST OF BWG. SCATTERED SHOWERS
DEVELOPING IN A LINE FROM JOHNSON COUNTY TO JACKSON COUNTY. EXPECT
LINE TO CONTINUE TO DEVELOP SW...AS THE LINE ITSELF PRESSES
SOUTHEAST. SHOWER THREAT HAS ENDED IN THE FAR NW PART OF FORECAST
AREA AND HAVE REMOVED RAIN CHANCES THERE. ALSO LOWERED RAIN
PROBABILITY TO NUMEROUS SHOWER TO SCATTERED THUNDERSTORM CHANCES
ELSEWHERE. HAVE UPDATED NDFD AND ZFP.
UPDATE ISSUED AT 953 AM EDT FRI AUG 17 2012
HAVE UPDATED NDFD AND ZFP BASED ON LATEST OBSERVATIONAL TRENDS.
EXTENSIVE CLOUDINESS WILL LIMIT DESTABILIZATION AND OVERALL
THUNDERSTORM CHANCES TODAY...BUT STILL EXPECT NUMEROUS TO WIDESPREAD
SHOWERS. BEST CHANCE FOR STRONGER THUNDERSTORMS WILL BE OVER THE
SOUTHEAST PART OF THE FORECAST AREA. 10Z HRRR IS SHOWING CONVECTION
DEVELOPING FROM MONTICELLO TO PAINTSVILLE THIS AFTERNOON AND THEN
MOVING SOUTHEAST.
UPDATE ISSUED AT 659 AM EDT FRI AUG 17 2012
UPDATED FOR CURRENT CONDITIONS/OBSERVED TRENDS. WITH LACK OF RETURNS
ON RADAR AND SLOWER PRECIP DEVELOPMENT IN 06Z RUNS...THIS INCLUDES
LATER DEVELOPMENT OF PRECIP THIS MORNING.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 352 AM EDT FRI AUG 17 2012
A COLD FRONT WILL APPROACH FROM THE NW TODAY...AND TRANSITION ACROSS
THE REGION TONIGHT. EXTENSIVE CLOUD COVER WILL LIMIT
DESTABILIZATION. HOWEVER...THE RIGHT ENTRANCE REGION OF AN UPPER JET
COINCIDING WITH THE FRONT WILL AID IN SUPPORT FOR PRECIP. WILL CALL
FOR 70-80 PERCENT POPS...BUT ONLY A CHANCE FOR THUNDER.
AS DRIER AIR ARRIVES FROM NW TO SE THIS AFTERNOON AND TONIGHT...
PRECIP WILL TAPER OFF AND CLOUDS WILL DECREASE. THIS WILL LEAVE A DRY
DAY ON SATURDAY...WITH SURFACE HIGH PRESSURE TO OUR NW BEING OUR
DOMINANT FEATURE.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 352 AM EDT FRI AUG 17 2012
MODELS REMAIN IN FAIRLY GOOD AGREEMENT THROUGH THE BEGINNING OF NEXT
WEEK DEPICTING ANOTHER LOW MOVING INTO HUDSON BAY BEFORE UNDERGOING
AN AMPLIFICATION OF THE TROF OVER THE ERN CONUS...WITH NUMEROUS
SHORT WAVES RIPPLING AROUND THE BACKSIDE OF THE LOW TRANSITING THE
OHIO VALLEY FROM LATE THIS WEEKEND INTO EARLY NEXT WEEK. AT THE
SFC...GUIDANCE POINTS TOWARDS HIGH PRESSURE OVER THE PLAINS EARLY IN
THE PERIOD SLIDING EAST INTO THE REGION AND LINGERING OVER THE AREA
THROUGH ABOUT THE MIDDLE OF NEXT WEEK BEFORE SHIFTING FURTHER EAST
AND ULTIMATELY OPENING UP A RETURN FLOW OF WARMER...MOIST GOMEX AIR
LATE IN THE PERIOD.
THE 17.00Z ECMWF BRINGS ONE OF THESE WAVES THROUGH THE AREA ON
SUNDAY NIGHT INTO MONDAY WHILE THE CONSENSUS SUGGESTS QUITE A BIT OF
DEEP MOISTURE IN PLACE OVER THE AREA...AND HAVE INCLUDED A SLIGHT
CHANCE FOR THE SE AND HIGHER TERRAIN ALONG THE KY/VA LINE THROUGH
THIS TIME FRAME. THE NERN CONUS TROF BEGINS TO LIFT OFF TO THE NE BY
MID WEEK...SOMEWHAT FASTER IN THE LATEST GFS SOLUTION...WHILE THE
EURO DEVELOPS A CLOSED LOW OVER THE CONFLUENCE OF THE MS/OH RIVERS.
HAVE SPLIT THE DIFFERENCE HERE AND INTRODUCED ANOTHER ROUND OF
SLIGHT CHANCE POPS TO ROUND OUT THE LONG TERM.
TEMPS THROUGH THE PERIOD STILL LOOK TO START OUT BELOW NORMAL BEFORE
MODERATING AROUND THE MIDDLE OF NEXT WEEK TO NEAR AND ABOVE NORMAL
BY THE END OF THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 146 PM EDT FRI AUG 17 2012
A COLD FRONT IS MOVING ACROSS THE AREA THIS AFTERNOON...BRINGING A
LINE OF SHOWERS AND A FEW THUNDERSTORMS TO THE SOUTHEASTERN PART OF
THE FORECAST AREA. THE SHOWERS ARE WELL AHEAD OF THE FRONT WHICH
EXTENDS FROM NEAR FGX TO GLW AT 17Z. JUST AHEAD OF AND BEHIND THE
FRONT THERE IS A LARGE AREA OF LOW CLOUDS WITH MVFR TO IFR CEILINGS.
EXPECT MVFR CEILINGS TO PREVAIL AT LOZ AND SME THIS AFTERNOON WITH
CEILINGS DECREASING TO IFR AT JKL. MOST OF THE SHOWERS WILL BE
SOUTHEAST OF THE TAF SITES BY 1830Z. THERE WILL BE SOME PARTIAL
CLEARING TONIGHT...WITH TEMPORARY VFR CONDITIONS. THE PARTIAL
CLEARING WILL SET THE STAGE FOR FOG FORMATION ESPECIALLY IN THE
SOUTHEAST PART OF THE FORECAST AREA WHERE RAIN WILL HAVE OCCURRED.
EXPECT IFR CONDITIONS IN FOG TO DEVELOP LATE TONIGHT...WITH
CONDITIONS IMPROVING TO VFR BY 14Z ON SATURDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SBH
SHORT TERM...HAL
LONG TERM....MB
AVIATION...SBH
AREA FORECAST DISCUSSION
NWS JACKSON KY
1237 PM EDT FRI AUG 17 2012
.UPDATE...
ISSUED AT 1235 PM EDT FRI AUG 17 2012
COLD FRONT SLOWLY PRESSING ACROSS THE STATE. AT 16Z FRONT EXTENDS
FROM JUST WEST OF FGX TO JUST EAST OF BWG. SCATTERED SHOWERS
DEVELOPING IN A LINE FROM JOHNSON COUNTY TO JACKSON COUNTY. EXPECT
LINE TO CONTINUE TO DEVELOP SW...AS THE LINE ITSELF PRESSES
SOUTHEAST. SHOWER THREAT HAS ENDED IN THE FAR NW PART OF FORECAST
AREA AND HAVE REMOVED RAIN CHANCES THERE. ALSO LOWERED RAIN
PROBABILTY TO NUMEROUS SHOWER TO SCATTERED THUNDERSTORM CHANCES
ELSEWHERE. HAVE UPDATED NDFD AND ZFP.
UPDATE ISSUED AT 953 AM EDT FRI AUG 17 2012
HAVE UPDATED NDFD AND ZFP BASED ON LATEST OBSERVATIONAL TRENDS.
EXTENSIVE CLOUDINESS WILL LIMIT DESTABILIZATION AND OVERALL
THUNDERSTORM CHANCES TODAY...BUT STILL EXPECT NUMEROUS TO WIDESPREAD
SHOWERS. BEST CHANCE FOR STRONGER THUNDERSTORMS WILL BE OVER THE
SOUTHEAST PART OF THE FORECAST AREA. 10Z HRRR IS SHOWING CONVECTION
DEVELOPING FROM MONTICELLO TO PAINTSVILLE THIS AFTERNOON AND THEN
MOVING SOUTHEAST.
UPDATE ISSUED AT 659 AM EDT FRI AUG 17 2012
UPDATED FOR CURRENT CONDITIONS/OBSERVED TRENDS. WITH LACK OF RETURNS
ON RADAR AND SLOWER PRECIP DEVELOPMENT IN 06Z RUNS...THIS INCLUDES
LATER DEVELOPMENT OF PRECIP THIS MORNING.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 352 AM EDT FRI AUG 17 2012
A COLD FRONT WILL APPROACH FROM THE NW TODAY...AND TRANSITION ACROSS
THE REGION TONIGHT. EXTENSIVE CLOUD COVER WILL LIMIT
DESTABILIZATION. HOWEVER...THE RIGHT ENTRANCE REGION OF AN UPPER JET
COINCIDING WITH THE FRONT WILL AID IN SUPPORT FOR PRECIP. WILL CALL
FOR 70-80 PERCENT POPS...BUT ONLY A CHANCE FOR THUNDER.
AS DRIER AIR ARRIVES FROM NW TO SE THIS AFTERNOON AND TONIGHT...
PRECIP WILL TAPER OFF AND CLOUDS WILL DECREASE. THIS WILL LEAVE A DRY
DAY ON SATURDAY...WITH SURFACE HIGH PRESSURE TO OUR NW BEING OUR
DOMINANT FEATURE.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 352 AM EDT FRI AUG 17 2012
MODELS REMAIN IN FAIRLY GOOD AGREEMENT THROUGH THE BEGINNING OF NEXT
WEEK DEPICTING ANOTHER LOW MOVING INTO HUDSON BAY BEFORE UNDERGOING
AN AMPLIFICATION OF THE TROF OVER THE ERN CONUS...WITH NUMEROUS
SHORT WAVES RIPPLING AROUND THE BACKSIDE OF THE LOW TRANSITING THE
OHIO VALLEY FROM LATE THIS WEEKEND INTO EARLY NEXT WEEK. AT THE
SFC...GUIDANCE POINTS TOWARDS HIGH PRESSURE OVER THE PLAINS EARLY IN
THE PERIOD SLIDING EAST INTO THE REGION AND LINGERING OVER THE AREA
THROUGH ABOUT THE MIDDLE OF NEXT WEEK BEFORE SHIFTING FURTHER EAST
AND ULTIMATELY OPENING UP A RETURN FLOW OF WARMER...MOIST GOMEX AIR
LATE IN THE PERIOD.
THE 17.00Z ECMWF BRINGS ONE OF THESE WAVES THROUGH THE AREA ON
SUNDAY NIGHT INTO MONDAY WHILE THE CONSENSUS SUGGESTS QUITE A BIT OF
DEEP MOISTURE IN PLACE OVER THE AREA...AND HAVE INCLUDED A SLIGHT
CHANCE FOR THE SE AND HIGHER TERRAIN ALONG THE KY/VA LINE THROUGH
THIS TIME FRAME. THE NERN CONUS TROF BEGINS TO LIFT OFF TO THE NE BY
MID WEEK...SOMEWHAT FASTER IN THE LATEST GFS SOLUTION...WHILE THE
EURO DEVELOPS A CLOSED LOW OVER THE CONFLUENCE OF THE MS/OH RIVERS.
HAVE SPLIT THE DIFFERENCE HERE AND INTRODUCED ANOTHER ROUND OF
SLIGHT CHANCE POPS TO ROUND OUT THE LONG TERM.
TEMPS THROUGH THE PERIOD STILL LOOK TO START OUT BELOW NORMAL BEFORE
MODERATING AROUND THE MIDDLE OF NEXT WEEK TO NEAR AND ABOVE NORMAL
BY THE END OF THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 659 AM EDT FRI AUG 17 2012
A FEW LIGHT SHOWERS WERE IN THE AREA EARLY THIS MORNING. ADDITIONAL
SHOWERS ARE EXPECTED TO DEVELOP DURING THE DAY...WITH MOST LOCATIONS
ENDING UP WET. THERE MAY ALSO BE THUNDERSTORMS...BUT CONFIDENCE IN
WHEN AND WHERE IS TOO LOW TO ALLOW ADDRESSING IT IN TAFS. LOCALIZED
MVFR AND IFR IS POSSIBLE IN PRECIP DURING THE DAY...BUT PREVAILING
WEATHER SHOULD BE VFR. PRECIP SHOULD END FROM NW TO SE DURING THE
AFTERNOON AND EVENING.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SBH
SHORT TERM...HAL
LONG TERM....MB
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS GRAY ME
637 PM EDT FRI AUG 17 2012
.SYNOPSIS...
A WEAK FRONTAL BOUNDARY WILL MOVE ACROSS NORTHERN NEW ENGLAND
TONIGHT BRINGING SCATTERED SHOWERS AND THUNDERSTORMS WITH IT. THE
FRONT WILL STALL OVER THE GULF OF MAINE AS LOW PRESSURE MOVES
ALONG IT SATURDAY INTO SUNDAY. AT THE PRESENT TIME IT LOOKS LIKE
MOST OF THE CLOUDS AND RAIN WITH THIS SYSTEM WILL STAY JUST EAST
OF THE REGION.
&&
.NEAR TERM /THROUGH SATURDAY/...
UPDATE...
CONVECTION CONTS TO MARCH EASTWARD...MUCH IN LINE WITH THE SAME
OVERALL PATTERN SHOWN IN THE LATEST HRRR MODEL. HAVE INCLUDED THE
POSSIBILITY OF GUSTY WINDS AND HAIL TO THE GRIDS AS WELL AS SOME
OF THE STMS ARE NOW SHOWING CORES WELL ABV THE FRZG LVL. HAVE ALSO
INCREASED POPS IN A LINE MOVG EASTWARD INTO CTNRL ME OVER THE NEXT
FEW HRS.
MADE A FEW ADJUSTMENTS TO CLOUD COVER AND DEW POINTS AS WELL.
OTRW...FCST WILL REMAIN RELATIVELY UNCHANGED.
PREV DISC...
MOSTLY SUNNY SKIES ACROSS THE REGION THIS AFTERNOON WITH DEW
POINTS MAINLY IN THE 50S TO LOWER 60S. A WEAK FRONTAL BOUNDARY IS
APPROACHING THE CWA FROM THE WEST. INSTABILITY AHEAD OF THE FRONT
IS AT BEST WEAK. APPEARS AS THOUGH THE NAM HAS A LITTLE BETTER
HANDLE ON THIS FEATURE THAN THE GFS DOES. ONLY ISOLATED SHOWERS
POPPING UP OVER THE ADIRONDACKS TO THE WEST OF US WHERE
INSTABILITY IS BETTER. BECAUSE OF THIS...WILL BACK OFF OF POPS A
BIT THIS AFTERNOON AND EVENING...ESPECIALLY OVER THE MOUNTAINS.
BOUNDARY LOOKS AS THOUGH IT WILL WASH OUT QUITE A BIT AS IT MOVES
ACROSS THE AREA.
&&
.SHORT TERM /SATURDAY NIGHT/...
THE FRONTAL BOUNDARY WILL STALL JUST OFFSHORE EARLY SATURDAY. THIS
LOOKS LIKE IT WILL BE THE TRICKIEST PART OF THE FORECAST. THE NAM
TAKES THE BOUNDARY INTO THE GULF OF MAINE SATURDAY MORNING. IT
DEVELOPS A WAVE THAT MOVES ALONG THE BOUNDARY AND PRODUCES SOME
PRECIPITATION JUST OFFSHORE. THE GFS ON THE OTHER HAND...KEEPS THE
BOUNDARY ALONG THE COAST AND GENERATES PRECIPITATION TOMORROW
MORNING ALONG THE COAST OF MAINE. AGAIN...FEEL AS THOUGH THE NAM
IS HANDLING THIS FEATURE BETTER DUE TO INITIALIZATION OF
CONVECTION OVER NEW YORK STATE TODAY. ONCE THE BOUNDARY IS CLEAR
OF THE COAST...HIGH PRESSURE WILL BUILD IN FOR TOMORROW NIGHT.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
FRONTAL SYSTEM WITH DEPARTING LOW WILL KEEP CLOUDS AND SHOWER
THREAT OVER THE COASTAL WATERS ON SUNDAY. EXPECT LAND AREAS TO
REMAIN DRY. CLOUDS ALONG THE IMMEDIATE COAST COULD BE PROBLEMATIC
DEPENDING ON HOW QUICKLY THE FRONT PUSHES EAST. HAVE GONE WITH A
EURO-GFS SOLUTION AS THE NAM IS SLOWER IN MOVING THE FRONT EAST.
WEAK RIDGING WILL KEEP THINGS DRY SUNDAY NIGHT INTO MONDAY. A WEAK
TROUGH WILL CROSS THE AREA LATE MONDAY INTO MONDAY NIGHT. THIS
MAY BRING A FEW SHOWERS WITH IT.
TUE-FRI THE AREA WILL BE UNDER A CYCLONIC FLOW ALOFT. WHILE NO
LARGE SCALE PRECIPITATION EVENT IS FORECAST...A FEW SHOWERS ARE
POSSIBLE ESPECIALLY DIURNALLY OVER THE MOUNTAINS. IN ADDITION ANY SHORT
WAVES MOVING THROUGH THIS CYCLONIC FLOW COULD TRIGGER SHOWERS.
TIMING OF THESE SUBTLE FEATURES IN THE LONG RANGE PORTION OF THE
FORECAST IS DIFFICULT. TEMPERATURES SHOULD BE NEAR NORMAL.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM...VFR CONDITIONS WILL PREVAIL INTO THE EVENING HOURS.
AN APPROACHING BOUNDARY MAY GENERATE SOME SCATTERED SHOWERS AND
THUNDERSTORMS THIS EVENING. EXPECT RADIATION FOG TO SET UP AGAIN
TONIGHT AND DROP VSBY AND CIGS TO IFR/LIFR BY MORNING. FOG SHOULD
NOT BE AS THICK AS LAST NIGHT AND IS EXPECTED TO BURN OFF QUICKER.
LONG TERM...MAINLY MVFR CONDITIONS EXPECTED.
&&
.MARINE...
SHORT TERM...NO FLAGS EXPECTED.
LONG TERM...WINDS AND SEAS WILL REMAIN BELOW SCA LEVELS.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAY ME
528 PM EDT FRI AUG 17 2012
.SYNOPSIS...
A WEAK FRONTAL BOUNDARY WILL MOVE ACROSS NORTHERN NEW ENGLAND
TONIGHT BRINGING SCATTERED SHOWERS AND THUNDERSTORMS WITH IT. THE
FRONT WILL STALL OVER THE GULF OF MAINE AS LOW PRESSURE MOVES
ALONG IT SATURDAY INTO SUNDAY. AT THE PRESENT TIME IT LOOKS LIKE
MOST OF THE CLOUDS AND RAIN WITH THIS SYSTEM WILL STAY JUST EAST
OF THE REGION.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
UPDATE...
HAVE UPDATED GRIDS BASED ON ONGOING CONVECTION PER LATEST KGYX
IMAGES. SHOWERS AND ISOLD TSTMS WILL CONT TO MOVE EASTWARD INTO
MAINE OVER THE NEXT HOUR. ANOTHER ROUND OF STMS WILL CROSS INTO
THE CT RVR VLY BY AROUND 6 PM OR SO AS WELL. THIS IS BEING PICKED
UP WELL BY THE LATEST HRRR MODEL.
MADE A FEW ADJUSTMENTS TO CLOUD COVER AND DEW POINTS AS WELL.
OTRW...FCST WILL REMAIN RELATIVELY UNCHANGED.
PREV DISC...
MOSTLY SUNNY SKIES ACROSS THE REGION THIS AFTERNOON WITH DEW
POINTS MAINLY IN THE 50S TO LOWER 60S. A WEAK FRONTAL BOUNDARY IS
APPROACHING THE CWA FROM THE WEST. INSTABILITY AHEAD OF THE FRONT
IS AT BEST WEAK. APPEARS AS THOUGH THE NAM HAS A LITTLE BETTER
HANDLE ON THIS FEATURE THAN THE GFS DOES. ONLY ISOLATED SHOWERS
POPPING UP OVER THE ADIRONDACKS TO THE WEST OF US WHERE
INSTABILITY IS BETTER. BECAUSE OF THIS...WILL BACK OFF OF POPS A
BIT THIS AFTERNOON AND EVENING...ESPECIALLY OVER THE MOUNTAINS.
BOUNDARY LOOKS AS THOUGH IT WILL WASH OUT QUITE A BIT AS IT MOVES
ACROSS THE AREA.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
THE FRONTAL BOUNDARY WILL STALL JUST OFFSHORE EARLY SATURDAY. THIS
LOOKS LIKE IT WILL BE THE TRICKIEST PART OF THE FORECAST. THE NAM
TAKES THE BOUNDARY INTO THE GULF OF MAINE SATURDAY MORNING. IT
DEVELOPS A WAVE THAT MOVES ALONG THE BOUNDARY AND PRODUCES SOME
PRECIPITATION JUST OFFSHORE. THE GFS ON THE OTHER HAND...KEEPS THE
BOUNDARY ALONG THE COAST AND GENERATES PRECIPITATION TOMORROW
MORNING ALONG THE COAST OF MAINE. AGAIN...FEEL AS THOUGH THE NAM
IS HANDLING THIS FEATURE BETTER DUE TO INITIALIZATION OF
CONVECTION OVER NEW YORK STATE TODAY. ONCE THE BOUNDARY IS CLEAR
OF THE COAST...HIGH PRESSURE WILL BUILD IN FOR TOMORROW NIGHT.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
FRONTAL SYSTEM WITH DEPARTING LOW WILL KEEP CLOUDS AND SHOWER
THREAT OVER THE COASTAL WATERS ON SUNDAY. EXPECT LAND AREAS TO
REMAIN DRY. CLOUDS ALONG THE IMMEDIATE COAST COULD BE PROBLEMATIC
DEPENDING ON HOW QUICKLY THE FRONT PUSHES EAST. HAVE GONE WITH A
EURO-GFS SOLUTION AS THE NAM IS SLOWER IN MOVING THE FRONT EAST.
WEAK RIDGING WILL KEEP THINGS DRY SUNDAY NIGHT INTO MONDAY. A WEAK
TROUGH WILL CROSS THE AREA LATE MONDAY INTO MONDAY NIGHT. THIS
MAY BRING A FEW SHOWERS WITH IT.
TUE-FRI THE AREA WILL BE UNDER A CYCLONIC FLOW ALOFT. WHILE NO
LARGE SCALE PRECIPITATION EVENT IS FORECAST...A FEW SHOWERS ARE
POSSIBLE ESPECIALLY DIURNALLY OVER THE MOUNTAINS. IN ADDITION ANY SHORT
WAVES MOVING THROUGH THIS CYCLONIC FLOW COULD TRIGGER SHOWERS.
TIMING OF THESE SUBTLE FEATURES IN THE LONG RANGE PORTION OF THE
FORECAST IS DIFFICULT. TEMPERATURES SHOULD BE NEAR NORMAL.
&&
.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
SHORT TERM...VFR CONDITIONS WILL PREVAIL INTO THE EVENING HOURS.
AN APPROACHING BOUNDARY MAY GENERATE SOME SCATTERED SHOWERS AND
THUNDERSTORMS THIS EVENING. EXPECT RADIATION FOG TO SET UP AGAIN
TONIGHT AND DROP VSBY AND CIGS TO IFR/LIFR BY MORNING. FOG SHOULD
NOT BE AS THICK AS LAST NIGHT AND IS EXPECTED TO BURN OFF QUICKER.
LONG TERM...MAINLY MVFR CONDITIONS EXPECTED.
&&
.MARINE...
SHORT TERM...NO FLAGS EXPECTED.
LONG TERM...WINDS AND SEAS WILL REMAIN BELOW SCA LEVELS.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
408 PM CDT FRI AUG 17 2012
.SHORT TERM...THROUGH SATURDAY DAYTIME. PRIMARY ISSUE DURING THE
NEXT 24 HOURS IS TRYING TO PIN DOWN HIGH WIDESPREAD
SHOWER/THUNDERSTORM ACTIVITY WILL BE LATE TONIGHT INTO THE DAYTIME
SATURDAY...AND THE RESULTANT EFFECTS ON HIGH TEMPERATURES.
19Z OBJECTIVE SURFACE ANALYSIS REVEALS AN INCREDIBLY PLEASANT
AFTERNOON ACROSS THE CWA WITH VERY LIGHT BREEZES...THANKS TO A
1020MB RIDGE AXIS PARKED DIRECTLY OVER THE AREA AND EXTENDING
NORTHEAST INTO MN. VISIBLE SATELLITE CONFIRMS NEARLY CLOUD-FREE
SKIES ACROSS THE NORTHEAST 1/2 OF THE CWA...WHILE IN THE
SOUTHWEST...WHAT WAS A FAIRLY SOLID MID LEVEL CLOUD DECK A FEW
HOURS AGO HAS STEADILY ERODED/SCATTERED OUT QUITE A BIT. WATER
VAPOR SATELLITE IMAGERY ALONG WITH SHORT TERM MODEL DATA DEPICTS
THE CWA UNDER SEASONABLY STRONG NORTHWEST FLOW ALOFT...SANDWICHED
BETWEEN A LARGE SCALE TROUGH OVER THE NORTHEAST CONUS WHICH IS
ANCHORED BY A VIGOROUS VORT MAX OVER EASTERN QUEBEC...AND A BROAD
RIDGE CENTERED FROM THE INTERMOUNTAIN WEST TO SOUTH TX. THE QUICK
MOVING SHORTWAVE/SPEED MAX THAT WILL BRING PRECIP CHANCES LATE
TONIGHT INTO SATURDAY IS CURRENTLY EVIDENT DROPPING SOUTHEAST NEAR
THE MT/ND/CANADA BORDER. TEMPS THIS AFTERNOON ARE VERY MUCH ON
TRACK WITH PREVIOUS FORECAST HIGHS...AND MAY ACTUALLY EXCEED THEM
SLIGHTLY IN SOME AREAS AS A FEW POTS ARE MAKING A RUN AT REACHING
80. AS SUGGESTED IN THE EARLIER UPDATE DISCUSSION...LIMITED MIXING
INTO VERY DRY AIR ALOFT HAS ALLOWED SURFACE DEWPOINTS TO FALL INTO
THE UPPER 30S IN SOME AREAS...ALTHOUGH LOW 40S ARE PREVALENT.
FOR THIS EVENING/TONIGHT...THE MOST SIGNIFICANT CHANGE WAS TO
COMPLETELY REMOVE ALL MENTION OF SHOWERS/STORMS BEFORE 06Z...AS
MOISTURE RETURN AND RESULTANT ELEVATED INSTABILITY NOW APPEARS
CONSIDERABLY MORE DELAYED THAN IT DID 24 HOURS AGO. THAT BEING
SAID...LATEST RAP-BASED HOURLY MESOANALYSIS INDICATED THE
PRESENCE OF UP TO 500 J/KG MUCAPE CURRENTLY SITTING ACROSS
SOUTHWEST ZONES ALONG THE LEADING EDGE OF MOISTURE RETURN AROUND
700MB. HOWEVER THE 12Z NAM WOULD SUGGEST THIS MUCAPE IS ACTUALLY
MORE MEAGER AND MORE CAPPED THAN THE RAP SUGGESTS...AND GIVEN THE
LIMITED FORCING AND THE FACT THAT A NUMBER OF DETERMINISTIC AND
HIGH RES MODELS SUCH AS THE 12Z 4KM WRF-NMM DO NOT INITIATE
CONVECTION IN THIS AREA THROUGH THIS EVENING...HAVE REMOVED THE
SLIGHT POPS. FOR THE LATE NIGHT 06Z-12Z PERIOD...DECIDED TO BREAK
THE POP/WX GRIDS INTO 3-HOUR BLOCKS...WITH THE PRIMARY FOCUS
SQUARELY ON THE VERY LATE NIGHT/EARLY MORNING HOURS POST-09Z. FOR
THE 06Z-09Z PERIOD...ONLY HAVE SLIGHT POPS CREEPING INTO A FEW FAR
SOUTHWEST COUNTIES. THEN AFTER 09Z...BRING IN 20-30 PERCENT
SHOWER/ISOLATED STORM CHANCES FOR ALL BUT ROUGHLY THE EASTERN 1/4
OF THE CWA. AS THE NIGHT WEARS ON...THE AFOREMENTIONED NORTHWEST
FLOW SHORTWAVE WILL REACH THE SD/NORTHERN NEB BORDER AREA...WHILE
OUT AHEAD OF IT...THETA-E ADVECTION MAINLY IN THE 850-700MB LAYER
WILL BE ON THE INCREASE...AS THE EASTERN EDGE OF A MODEST 850MB
LOW LEVEL JET VEERS INTO THE AREA. INTERESTINGLY...THE NEWLY
ARRIVED 18Z NAM KEEPS MOST ALL OF THIS ACTIVITY OUTSIDE THE CWA
UNTIL AFTER SUNRISE...BUT FEEL AT LEAST 20-30 POPS ARE WARRANTED
BASED ON THE 4KM WRF-NMM AND NSSL 4KM-WRF DEPICTION OF ONE BATCH
OF SHOWERS/FEW STORMS SLIDING INTO THE CWA FROM THE
NORTHWEST...WHILE ANOTHER POTENTIALLY SEPARATE AREA DEVELOPS OVER
THE SOUTHWESTERN CWA MAINLY IN KS. ALTHOUGH NOT ANTICIPATING A
SEVERE WEATHER THREAT THROUGH SUNRISE WITH MUCAPE LIKELY REMAINING
NO MORE THAN A FEW HUNDRED J/KG...SUPPOSE A FEW STRONGER CORES
WITH SMALL HAIL CANNOT BE RULED OUT GIVEN STRONG DEEP LAYER SHEAR
ON THE ORDER OF 50+ KNOTS. TEMP WISE TONIGHT...GIVEN THE SLOWER
ONSET OF CLOUDS AND STORM CHANCES...AND WITH WINDS REMAINING LIGHT
AS THE RIDGE AXIS SLOWLY DEPARTS...NUDGED DOWN LOWS TONIGHT 2-3
DEGREES IN MOST AREAS...WITH MUCH OF THE CWA AIMED INTO THE 50-53
RANGE...AND EVEN COOLER MID-UPPER 40S IN THE FAR EAST...BUT NOT
RECORD-BREAKING TERRITORY.
TURNING TO THE DAYTIME PERIOD 12Z-00Z...SPLIT THE DAY INTO 6-HOUR
BLOCKS FOR POPS/WEATHER...WITH THE OVERALL BEST RAIN CHANCES FOCUSED
DURING THE MORNING. ALOFT...THE COMPACT BUT FAIRLY VIGOROUS
NORTHWEST FLOW WAVE WILL DIVE SOUTHWARD ACROSS THE EASTERN HALF OF
NEBRASKA TOWARD NORTHEAST KANSAS DURING THE DAY...ACCOMPANIED BY
AN ASSOCIATED UPPER LEVEL JET STREAK. ALTHOUGH IT WILL NOT BE AN
ALL-DAY RAIN OUT BY ANY MEANS...THE CONSENSUS OF VARIOUS MODELS
INCLUDING THE 12Z 4KM WRF-NMM REFLECTIVITY SHOWS A DECENT CHANCE
FOR AT LEAST SCATTERED SHOWERS/A FEW STORMS SPREADING SOUTHEAST
ACROSS THE CWA DURING THE DAY...POSSIBLY IN TWO SEPARATE ROUNDS
WITH ONE ROUND DURING THE MORNING...FOLLOWED BY MORE HIT AND MISS
ACTIVITY DURING THE AFTERNOON DIRECTLY UNDER THE SHORTWAVE AXIS.
WITH THE OVERALL BEST COVERAGE EXPECTED DURING THE MORNING
HOURS...INCREASED POPS TO 50S ACROSS ROUGHLY THE NORTHWEST 1/2 OF
THE CWA...BUT KEPT THEM BELOW LIKELY TERRITORY FOR NOW. DURING THE
AFTERNOON...WENT LOWER WITH POPS BUT KEPT AT LEAST 20-30 PERCENT
CHANCES AND HIGHEST ACROSS THE EASTERN 1/2. AS FOR SEVERE
CHANCES...WITH BOTH ELEVATED AND NEAR SURFACE-BASED PARCELS NOT
EXPECTED TO AVERAGE MORE THAN 500 J/KG MOST AREAS...WHICH CAME IN
LOWER ON THE 18Z NAM THAN ITS 12Z RUN...NOT EXPECTING SEVERE
STORMS TO BE A BIG ISSUE. HOWEVER...GIVEN THE VIGOROUS WAVE AND
CONTINUED SEASONABLY STRONG DEEP LAYER SHEAR...AT LEAST A FEW
STRONG TO MARGINALLY SEVERE STORMS MAINLY WITH HAIL POTENTIAL TO
AROUND QUARTER SIZE ARE NOT OUT OF THE QUESTION...ESPECIALLY IN
KANSAS ZONES...AND AGREE WITH SPC ON HIGHLIGHTING THESE SOUTHERN
ZONES FOR 5 PERCENT SEVERE PROBS ON THE DAY 2 OUTLOOK. AS FOR RAIN
AMOUNTS SATURDAY...WOULD EXPECT THAT MOST PLACES WILL AVERAGE
UNDER ONE-QUARTER INCH...SO NOT A MAJOR BOOST TO DROUGHT RELIEF BY
ANY MEANS. TEMP-WISE...IT WILL BE A TRICKY BATTLE BETWEEN
WIDESPREAD CLOUDS/SCATTERED RAIN FOR THE MAJORITY OF THE DAY...BUT
POTENTIAL FOR DECENT AFTERNOON CLEARING ESPECIALLY NORTHWEST.
OVERALL MADE NO BIG CHANGES...BUT RAISED WESTERN ZONES A FEW
DEGREES...ESPECIALLY UP AROUND ORD. HAVE MOST OF THE CWA TOPPING
OUT IN THE 76-81 RANGE.
.LONG TERM...STARTING SATURDAY EVENING. GUIDANCE SUGGESTS
NORTHWESTERLY UPPER LEVEL FLOW WILL PERSIST OVER THE CENTRAL
PLAINS THROUGH MUCH OF THE EXTENDED FORECAST PERIOD AS UPPER LEVEL
RIDGING REMAINS RELEGATED TO THE SOUTHWESTERN CONUS. QPF FIELDS
FROM THE SREF- MEAN...NAM AND OPERATIONAL GFS SUGGEST LINGERING
PRECIPITATION WILL BE POSSIBLE OVER OUR SOUTHEASTERN CWA 00Z-06Z
SUNDAY AS A MID LEVEL SHORT WAVE DEPARTS THE AREA. AS A
RESULT...WENT AHEAD AND KEPT 20% POPS GOING ACROSS OUR SOUTHEAST
00Z-06Z SUNDAY. A FEW SMALL-SCALE MID LEVEL PERTURBATIONS COULD
POTENTIALLY PUSH OVER THE CENTRAL PLAINS SUNDAY AND MONDAY.
DESPITE THE POSSIBILITY OF THESE SMALL-SCALE DISTURBANCES...OPTED
TO KEEP THE CWA DRY DURING THIS TIME PERIOD GIVEN THE VERY LOW
PROBABILITY OF PRECIPITATION ACTUALLY BEING REALIZED FROM ANY ONE
OF THESE FEATURES. THE EC...OPERATIONAL GFS AND GEFS-MEAN ALL
ADVERTISE A MORE SIGNIFICANT MID LEVEL SHORT WAVE WILL PUSH
SOUTHEAST ACROSS THE CENTRAL HIGH PLAINS MONDAY NIGHT INTO
TUESDAY. AT THIS TIME IT APPEARS THE BULK OF THE DPVA AND MID
LEVEL THERMAL ADVECTION WILL REMAIN SOUTHWEST OF OUR AREA...BUT
THERE MAY BE JUST ENOUGH OMEGA FOR PRECIPITATION ACROSS OUR
WEST/SOUTHWEST AND AS A RESULT...WENT AHEAD AND KEPT 20%-30% POPS
GOING ACROSS OUR WEST/SOUTHWEST FOR MONDAY NIGHT. SOME OF THIS
OMEGA MAY CREEP A BIT FARTHER EAST INTO OUR AREA DURING THE DAY
TUESDAY SO WENT AHEAD AND SPREAD POPS A BIT FARTHER EAST ACROSS
THE CWA DURING THE DAY TUESDAY AS A RESULT. AN OVERALL LACK IN
KINEMATIC FORCING SHOULD THEN PRESENT DRY CONDITIONS TO OUR AREA
TUESDAY NIGHT THROUGH THURSDAY...WITH GUIDANCE SUGGESTING YET
ANOTHER MID LEVEL SHORT WAVE WILL BRING PRECIPITATION CHANCES TO
MUCH OF THE AREA THURSDAY NIGHT INTO FRIDAY.
VERY LITTLE CHANGE IN THE LOW LEVEL AIRMASS SUGGESTS TEMPERATURES
SUNDAY THROUGH FRIDAY WILL BE FAIRLY SIMILAR...WITH PERHAPS A SLIGHT
WARMING TREND TOWARDS THE END OF THE FORECAST PERIOD. GIVEN
THIS...BELOW-NORMAL TEMPERATURES ARE FORECAST ACROSS THE CWA SUNDAY
WITH HIGHS IN THE UPPER 70S AND LOWS IN THE UPPER 40S TO NEAR 50.
SLIGHTLY WARMER BUT STILL BELOW-NORMAL TEMPERATURES ARE THEN
FORECAST FOR MUCH OF THE CWA MONDAY BEFORE WEAK LOW LEVEL WARM
ADVECTION PROVIDES NEAR TO SLIGHTLY ABOVE-NORMAL TEMPERATURES
TUESDAY ONWARD.
&&
.PREV DISCUSSION... /ISSUED 1217 PM CDT FRI AUG 17 2012/
AVIATION...18Z KGRI TAF. VFR CEILING/VISIBILITY IS FORECAST
THROUGH THE NEXT 24 HOURS...WITH THE MAIN CONCERN BEING A RISK FOR
SHOWERS/WEAK THUNDERSTORMS DURING PARTS OF THE FINAL 6 HOURS OF
THE PERIOD MAINLY SATURDAY MORNING. PRIOR TO THIS PRECIPITATION
POSSIBILITY...THE REST OF TODAY AND THROUGH TONIGHT WILL FEATURE
LIGHT/GENERALLY VARIABLE BREEZES AS A SURFACE HIGH PRESSURE AXIS
DEPARTS...ALONG WITH AT MOST A SMATTERING OF MID LEVEL CLOUD
COVER. FOR NOW...DECIDED TO GO WITH A PROB30 -TSRA MENTION FROM
12Z-18Z TO COVER THE THUNDERSTORM RISK...AND WILL DEFER TO LATER
FORECASTS TO INSERT POSSIBLE TEMPO/PREVAILING GROUPS AS THE EVENT
NEARS AND TIMING CONFIDENCE INCREASES. EVEN DURING POSSIBLE
THUNDERSTORM ACTIVITY...DO NOT FORESEE CEILING DROPPING EVEN CLOSE
TO MVFR THRESHOLDS...AND VISIBILITY SHOULD REMAIN VFR AS WELL
UNLESS A BRIEF HEAVY RAIN CORE SLIDES THROUGH.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM/AVIATION...PFANNKUCH
LONG TERM...BRYANT
AREA FORECAST DISCUSSION
NWS BUFFALO NY
134 PM EDT FRI AUG 17 2012
.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO MOVE ACROSS NEW YORK THIS AFTERNOON.
FOLLOWING THE FRONT EXPECT COOLER TEMPERATURES AND LESS HUMID
CONDITIONS FOR THIS AFTERNOON AND THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE COLD FRONT HAS CROSSED PRETTY MUCH ALL OF THE CWA WITH SOME
LINGERING SHOWERS ACROSS THE SOUTHEAST SECTIONS.
WITH COOLER AIR MOVING IN BEHIND THE FRONT...AND THE RELATIVELY
WARM LAKES...EXPECT ANY BRIEF CLEARING WILL LIKELY FILL IN WITH
LAKE-AIDED STRATOCUMULUS THIS AFTERNOON. THE HRRR HAS CONSISTENTLY
DEVELOPED SHOWERS AS A SW FLOW OFF LAKE ERIE CONVERGES WITH A MORE
WNW FLOW. FEEL THIS IS A REAL POSSIBILITY...SO WILL CARRY A CHANCE
FOR SHOWERS CENTERED IN THE NORTHTOWNS WHERE THIS CONVERGENCE
TYPICALLY OCCURS.
OTHERWISE...HIGH PRESSURE WILL BUILD ACROSS THE REGION FROM THE WEST
TONIGHT. THIS SHOULD RESULT IN A GENERAL DRYING TREND...WHERE
LINGERING CLOUDS FROM THE DAY SHOULD DISSIPATE. THIS SAID...A MORE
WESTERLY FLOW ON LAKE ONTARIO MAY ALLOW FOR LAKE CONVERGENCE CLOUDS
TO DEVELOP AND MOVE EAST OF LAKE ONTARIO LATE TONIGHT. THERE SHOULD
BE AMPLE PERIODS OF CLEARING TO ALLOW FOR TEMPERATURES TO COOL
CONSIDERABLY TONIGHT. LOWS WILL LIKELY RANGE FROM THE MID AND UPPER
40S IN THE COOL VALLEYS OF THE SOUTHERN TIER AND EAST OF LAKE ONTARIO...TO
THE LOWER 50S ELSEWHERE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
DURING THE WEEKEND...OUR REGION WILL REMAIN UNDER THE INFLUENCE OF
DEEP UPPER TROUGHING CENTERED NEAR JAMES BAY...WHILE SURFACE BASED
RIDGING OVER THE OHIO VALLEY AND LOWER LAKES GRADUALLY EXPANDS
NORTHEASTWARD INTO NEW ENGLAND.
UNDER THIS PATTERN...COOLER AND MAINLY DRY WEATHER WILL BE
PREDOMINANT. WHILE TEMPS ALOFT WILL BE CERTAINLY COOL ENOUGH FOR A
LAKE RESPONSE...THE RELATIVELY DRY NATURE OF OUR AIRMASS AND A FAIR
AMOUNT OF LOW LEVEL SHEAR SHOULD PREVENT MUCH MORE THAN SOME
LAKE-DRIVEN STRATOCU DOWNWIND OF THE LAKES EARLY SATURDAY
MORNING...AND AGAIN LATER SATURDAY NIGHT INTO EARLY SUNDAY.
SYNOPTICALLY...THE NAM/GFS/ECMWF ALL TRY TO SPIT OUT SOME SPOTTY
LIGHT SHOWERS ACROSS PARTS OF THE AREA SUNDAY AFTERNOON WITH DAYTIME
HEATING AND THE APPROACH OF A MODEST SHORTWAVE...BUT THIS STILL
APPEARS TO BE WORTHY OF NO MORE THAN SOME SLIGHT CHANCE POPS GIVEN
ONLY VERY LIMITED AMOUNTS OF AVAILABLE MOISTURE.
IN TERMS OF ACTUAL TEMPERATURES...850 MB READINGS WILL AVERAGE IN
THE +7C TO +9C RANGE SATURDAY...AND A DEGREE OR SO WARMER THAN THAT
ON SUNDAY. THIS WILL TRANSLATE INTO COMFORTABLE HIGHS IN THE LOWER
70S ON SATURDAY...AND THE LOWER TO MID 70S ON SUNDAY. MEANWHILE...
NIGHTTIME LOWS SATURDAY NIGHT WILL RANGE FROM THE MID 40S ACROSS
INTERIOR SECTIONS OF THE SOUTHERN TIER AND NORTH COUNTRY TO THE
LOWER 50S ALONG THE LAKE PLAINS...BEFORE MODERATING A FEW DEGREES
FOR SUNDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
THE COOL WEATHER OF THE SHORT TERM PERIOD WILL PERSIST INTO THE
FIRST COUPLE DAYS OF THE EXTENDED RANGE AS WELL...AS THE LARGE-SCALE
UPPER TROUGH REMAINS IN PLACE ACROSS THE GREAT LAKES AND NORTHEAST.
WITH DAYTIME HEATING OF THE STILL-COOL AIRMASS ALOFT...THE PASSAGE
OF A VERY WEAK SURFACE TROUGH COULD SET OFF SOME ISOLATED SHOWER AND
THUNDERSTORM ACTIVITY ON MONDAY...WITH THE APPROACH AND PASSAGE OF
THE MAIN UPPER TROUGH AXIS POSSIBLY DOING THE SAME ON TUESDAY. WILL
ACCORDINGLY KEEP SLIGHT CHANCE POPS IN PLACE FOR BOTH DAYS...WITH
ANY PRECIP THAT DOES FORM DIMINISHING WITH THE LOSS OF HEATING BOTH
MONDAY AND TUESDAY EVENINGS. 850 MB TEMPS LINGERING IN THE +8C TO
+10C RANGE WILL SUPPORT HIGHS IN THE LOWER TO MID 70S BOTH
DAYS...WITH NIGHTTIME LOWS IN THE 50S EXPECTED BOTH NIGHTS.
AFTER THAT...THE GFS AND ECMWF REMAIN IN GOOD AGREEMENT ON THE CORE
OF THE UPPER TROUGH LIFTING OFF INTO LABRADOR AND THEN INTO THE
NORTHERN ATLANTIC...WITH A RELATIVELY FLAT ZONAL FLOW SETTING UP
ACROSS THE LOWER LAKES AND NORTHEAST IN ITS WAKE. THE ENSUING WARM
AIR ADVECTION PATTERN WILL RESULT IN A GRADUAL WARMING TREND THROUGH
THE PERIOD...WITH DAYTIME HIGHS RECOVERING TO NEAR THE 80 DEGREE
MARK BY THURSDAY...AND NIGHTTIME LOWS ALSO MODERATING A FEW DEGREES
EACH NIGHT. AS FOR PRECIP CHANCES...THESE LOOK TO BE PRACTICALLY NIL
ON WEDNESDAY WITH THE DEPARTURE OF THE TROUGH AND LOW-LEVEL RIDGING
REMAINING IN PLACE...BEFORE CLIMBING BACK INTO THE SLIGHT CHANCE
RANGE ON THURSDAY WITH THE APPROACH OF ANOTHER WEAK SURFACE TROUGH.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
THE COLD FRONT HAS MOVED THROUGH ALL OF THE TAF SITES AND
CONTINUES TO MOVE TO THE EAST OF THE CWA. VFR CONDS BEHIND THE
FRONT WILL OCNLY LOWER TO MVFR AS A FAIR AMOUNT OF CU DEVELOPS IN
THE SELF-DESTRUCTIVE SUNSHINE. THERE MAY BE A FEW STRAY SHOWERS IN
THE KIAG-KBUF VCNTY ALONG THE LAKE ERIE / LAKE ONTARIO LAKE
CONVERGENCE BOUNDARY.
CLOUDS SHOULD SLOWLY SCATTER OUT TONIGHT AS WINDS OFF THE LAKES
DIMINISH...AND DRIER AIR MOVES IN. AS COOL AIR BUILDS IN ALOFT
EXPECT SOME LAKE CLOUDS TO DEVELOP SOUTHWEST OF LAKES ERIE AND
ONTARIO PRODUCING LOCALIZED MVFR CIGS. THERE COULD BE SOME FOG IN
JHW...OTHERWISE EXPECT VFR CONDITIONS TONIGHT.
OUTLOOK...
SUNDAY...VFR.
MONDAY...CHANCE OF SHOWERS/TSTMS. MAINLY VFR.
TUESDAY AND WEDNESDAY...VFR.
&&
.MARINE...
THE COLD FRONT HAS CROSSED THE LAKES WITH A WEST TO NORTHWEST FLOW
ESTABLISHING ITSELF ACROSS THE LAKES.
THE BRISK FLOW WILL PRODUCE WAVES INCREASING TO 5 FT ACROSS THE
EASTERN LAKE ONTARIO REGION. SMALL CRAFT ADVISORIES HAVE BEEN
POSTED THROUGH THE EARLY OVERNIGHT FOR THESE AREAS.
AS THE SURFACE HIGH BUILDS ACROSS THE REGION OVERNIGHT AND
SATURDAY WINDS WILL DIMINISH.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR LEZ040-
041.
SMALL CRAFT ADVISORY UNTIL 2 AM EDT SATURDAY FOR
LOZ044-045.
&&
$$
SYNOPSIS...APFFEL/LEVAN
NEAR TERM...APFFEL/LEVAN
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...LEVAN
MARINE...LEVAN
AREA FORECAST DISCUSSION
NWS RALEIGH NC
130 PM EDT FRI AUG 17 2012
.SYNOPSIS...
A COLD FRONT...WILL APPROACH THE AREA THIS EVENING AND MOVE INTO
CENTRAL NORTH CAROLINA ON SATURDAY.. MEANWHILE...AN UPPER LEVEL
TROUGH WILL DEVELOP OVER THE EASTERN US AND BRING PERIODS OF SHOWERS
AND STORMS THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY NIGHT/...
AS OF 955 AM FRIDAY...
TODAY...
CLEAR SKIES ARE OBSERVED ACROSS THE AREA THIS MORNING AS
CONVECTIVE/FRONTAL CLOUD COVER REMAINS MOSTLY WEST OF THE
MOUNTAINS. THE 12Z KGSO RAOB HAD A 1408M LOW LEVEL
THICKNESS...WHICH YIELDS HIGHS OF 88-92 UNDER FULL SUN...CONSISTENT
WITH THE CURRENT FORECAST. REMNANT OUTFLOW AND A SHEARING LOBE OF
VORTICITY APPROACHING THE MOUNTAINS FROM THE WEST WILL BE THE MAIN
FOCUS FOR ANY CONVECTION THIS AFTERNOON. THE RAP SHOWS TWO AREAS OF
STRONGER VORTICITY...ONE DIVING SOUTH INTO NORTHERN GA..AND THE
SECOND STRADDLING THE NC/VA BORDER THIS EVENING. DEWPOINTS ARE
CURRENTLY IN THE LOW TO MID 60S OVER THE WESTERN PIEDMONT..AND
ALTHOUGH THE LEE TROUGH WILL SHARPEN AHEAD OF THE BROAD CYCLONIC
FLOW DEVELOPING OVER THE EASTERN US...GUIDANCE DOES NOT SHOW MUCH
DEWPOINT RECOVERY ALONG THE TROUGH AXIS UNTIL LATE THIS EVENING AND
OVERNIGHT. COMBINED WITH WEAK LAPSE RATES ALOFT...ONLY A WEAK
INSTABILITY AXIS OF 500 TO MAYBE 1000 J/KG MLCAPE IS ANTICIPATED
EAST OF THE MOUNTAINS THIS AFTERNOON. PW IS RELATIVELY LOW ACROSS
THE CWA THIS MORNING...DOWN AROUND ONE INCH...BUT IS FORECAST TO
SURGE TO NEAR 1.75 INCHES THIS EVENING AS GOOD MID-LEVEL MOISTURE
ADVECTS IN FROM THE WEST. SCATTERED SHOWERS AND STORMS MAY HAVE
INITIALLY HAVE A HARD TIME MOVING EAST OF THE MOUNTAINS THIS
AFTERNOON...BUT STEEP LOW LEVEL LAPSE RATES AND 20-25KT OF MID LEVEL
FLOW COULD SUPPORT ENHANCED DOWNDRAFTS FROM EVAPORATIONAL COOLING
AND A FEW STORM CLUSTERS WITH ORGANIZED COLD POOLS IF CONVECTION IS
AS ROBUST AS A COUPLE OF THE CAMS ARE SHOWING. -SMITH
OVERNIGHT: SHOWERS AND STORMS WILL DRIFT EASTWARD IN A WEAKENING
STATE OWING TO NOCTURNAL COOLING/STABILIZATION OVERNIGHT. WHILE
CONTINUED 20-30 KTS OF EFFECTIVE BULK SHEAR WILL PERSIST...THIS WILL
LIKELY BE INSUFFICIENT TO COMPENSATE FOR THE RELATIVE LACK OF
STEADILY DECREASING BUOYANCY...SO ANY PRIOR SEVERE WEATHER THREAT
SHOULD DIMINISH PRIOR TO MIDNIGHT. NONETHELESS...SOME SHOWERS AND
ISOLATED STORMS ARE APT TO CONTINUE THROUGHOUT THE NIGHT...AS THE
SYNOPTIC SURFACE FRONTAL -- WHICH SIGNIFICANTLY LAGS THE ONGOING
PRE-FRONTAL MCS/S...AND ASSOCIATED OUTFLOW THAT WILL LIKELY HAVE A
DIFFICULT TIME CRESTING THE BLUE RIDGE TODAY -- GRADUALLY SETTLES
INTO AT LEAST THE NORTHWEST PIEDMONT TOWARD SUNRISE. CLOUDY OR
MOSTLY SO...WITH LOWS IN LOWER 70S FOR MOST.
SATURDAY: THERE ARE MIXED SIGNALS WITH RESPECT TO CONVECTIVE
COVERAGE AND INTENSITY ON SATURDAY. ON ONE HAND...LOW LEVEL FORCING
SHOULD BE QUITE STRONG AS THE LOW LEVEL FRONTAL ZONE...DEEP THROUGH
AT LEAST H85...SETTLES SOUTHEASTWARD THROUGH ALL OF CENTRAL NC BY
EVENING - A CHANGE FROM THE EARLIER EXPECTATION THAT THE BOUNDARY
WOULD STALL OVERHEAD THROUGH EARLY NEXT WEEK. ON THE OTHER
HAND...HOWEVER...THE PRECEDING PASSAGE OF THE LEAD MID LEVEL TROUGH
AXIS THROUGH CENTRAL NC FRI NIGHT...AND ASSOCIATED TRAILING NEUTRAL
TO WEAKLY RISING HEIGHTS ALOFT...SUGGESTS DEEPER LAYER SUBSIDENCE
WILL BE IN PLACE OVERHEAD. GIVEN THE DEPTH AND VIGOR OF THE LOW
LEVEL FRONTAL ZONE...IN CONJUNCTION WITH LOW LCL/LFC HEIGHTS AMIDST
HIGH BL MOISTURE CHARACTERIZED BY WARM SECTOR SURFACE DEWPOINTS AOA
70 DEGREES AND TEMPERATURES IN THE 80S...WILL LEAN TOWARD A HIGHER
LIKELIHOOD OF SHOWERS AND STORMS...DESPITE THE DEEPER LAYER
SUBSIDENCE. WHILE PRECIPITATION CHANCES SHOULD DIMINISH FROM
NORTHWEST TO SOUTHEAST WITH TIME AND THE PASSAGE OF THE FRONTAL
ZONE...A FEW ANAFRONTAL SHOWERS MAY CONTINUE TO PERCOLATE ON THE
IMMEDIATE COOL SIDE OF THE BOUNDARY WHERE ISENTROPIC UPGLIDE AND
LINGERING...ALBEIT DIMINISHED WEAK INSTABILITY...WILL COINCIDE.
WHILE EFFECTIVE BULK SHEAR VALUES WILL INCREASE INTO THE 25 TO 40 KT
RANGE BY LATE AFTERNOON AND EVENING...IN ADVANCE OF A S/W TROUGH
FORECAST TO LIFT THROUGH THE MIDDLE ATLANTIC STATES...THIS BELT OF
STRONGER FLOW IS FORECAST TO LAG THE MODERATELY UNSTABLE WARM
SECTOR. AS SUCH...MULTI-CELL CONVECTIVE MODES WITH A PRIMARY THREAT
OF DAMAGING WINDS SHOULD DOMINATE...ALTHOUGH THERE MAY BE A RELATIVE
SWEET SPOT IN A NARROW CORRIDOR ROUGHLY FROM ROCKINGHAM TO RALEIGH
TO ROANOKE RAPIDS...WHERE MORE OPTIMAL VALUES OF SHEAR AND
INSTABILITY MAY CO-EXIST AND SUPPORT A CONDITIONAL THREAT OF BRIEF
SUPERCELLULAR STRUCTURES.
SAT NIGHT: DRY WITH POST-FRONTAL NORTH TO NORTHEASTERLY FLOW...WITH
LOWS IN THE 64 TO 70 DEGREE RANGE.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 320 AM EDT...
SURFACE TROUGH FORECAST TO BE EAST AND SOUTHEAST OF CENTRAL NORTH
CAROLINA AT SUNRISE SUNDAY... BUT WITH SURFACE DEWPOINTS IN EXCESS
OF 65 DEGREES AND A BROAD UPPER TROUGH EXTENDING SOUTH INTO THE GULF
STATES... RAIN CHANCES WILL CONTINUE. PRECIPITABLE WATERS ROUGHLY
1.5 INCHES NORTHWEST TO 1.75 INCHES SOUTHWEST... WITH SURFACE BASED
CAPE IN EXCESS OF 2500 JOULES SOUTHEAST... TO NEAR 2000 NORTHWEST.
MID LEVEL WINDS OF 35 TO 45 KNOTS AND MIXING HEIGHTS ONLY TO 4000
FEET. THE AIR MASS IS PRIMED FOR A FEW SEVERE THUNDERSTORMS IN THE
AFTERNOON WITH DAMAGING WINDS THE MAIN THREAT. THE BIGGEST CONCERN
IS LACK OF A SIGNIFICANT TRIGGER OTHER THAN DAYTIME HEATING. HOWEVER
CONVECTIVE TRIGGER TEMPERATURES ARE A LOW 80 TO 85 DEGREES... AND
WILL RETAIN AFTERNOON POPS OF 50 TO 60 PERCENT.
LOSS OF HEATING SHOULD END MOST CONVECTION... BUT A THUNDERSTORM OR
TWO COULD PERSIST PAST MIDNIGHT IN THIS ENVIRONMENT.
THE UPPER TROUGH CONTINUES ITS SLOW APPROACH FROM THE WEST MONDAY.
THE MID LEVEL PRESSURE GRADIENT TIGHTENS WITH A DEEP LAYER OF
SOUTHWEST WINDS OF 30 TO 45 KNOTS... STRONGEST SOUTHEAST.
PRECIPITABLE WATERS PERHAPS EXCEEDING TWO INCHES SOUTHEAST. 850
MILLIBAR TROUGH WILL BE NEAR OR EAST OF HIGHWAY ONE... AND HIGHEST
RAIN CHANCES WILL BE IN THAT AREA MONDAY AFTERNOON. FORTY PERCENT
POPS NORTHWEST TO 50 SOUTHEAST WITH THE THREAT FOR DAMAGING WINDS
SIMILARLY HIGHER SOUTHEAST THAN NORTHWEST DUE TO HIGHER INSTABILITY
AND POTENTIAL ENERGY.
WINDS ALOFT BEGIN TO WEAKEN A BIT MONDAY NIGHT... WITH SOME DRYING
ALOFT IN THE WEST AFTER MIDNIGHT. UNLESS THERE IS SOME MINOR SHORT
WAVE FOR UPPER LEVEL SUPPORT... MOST CONVECTION SHOULD END IN THE
EVENING. A VERY FEW SHOWERS OR A THUNDERSTORM COULD PERSIST PAST
MIDNIGHT... MAINLY NEAR AND EAST OF HIGHWAY ONE.
AFTERNOON LOW LEVEL THICKNESSES ABOUT FIVE METERS BELOW CLIMATOLOGY
SUNDAY... AND TEN TO FIFTEEN METERS MONDAY. TEMPERATURES BELOW
NORMAL... WITH HIGH TEMPERATURES 80 TO 85 SUNDAY... LOW 80S MONDAY.
LOWS BELOW NORMAL IN SPITE OF CLOUDS... AT LOWER 60S NORTHWEST TO
MID 60S SOUTHEAST.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 340 PM FRIDAY...
ROUGH CONSENSUS IN BEGINNING TO SHEAR OUT THE UPPER TROUGH TO OUR
WEST TUESDAY AS IT LIFTS NORTHEAST... WITH THE ECMWF MORE AGGRESSIVE
THAN THE GFS IN THIS PROCESS. A WEAK SURFACE TROUGH FORECAST NEAR OR
EAST OF INTERSTATE 95... AND WILL PLACE HIGHEST RAIN CHANCES THERE.
30 PERCENT RAIN CHANCE WELL EAST... WHICH MAY PROVE TOO LOW. LESS
THAN ONE IN SEVEN ELSEWHERE.
SIGNIFICANT DIFFERENCES IN THE UPPER LEVEL PATTERN FOR WEDNESDAY AND
THURSDAY IN THE MODELS... AND FORECAST IS OF BELOW AVERAGE
CONFIDENCE. ROUGH AGREEMENT IN SOUTHWEST FLOW ALOFT. THE CURRENT
FORECAST OF SLIGHT AFTERNOON RAIN CHANCES IS A BIT BELOW CLIMATOLOGY
BUT WITHIN REASON GIVEN UNCERTAINTY.
AFTERNOON TEMPERATURES WILL BE FORECAST NEAR TO A TOUCH BELOW
CLIMATOLOGY AT LOW TO MID 80S. LOW TEMPERATURES LOWER 60S NORTHWEST
TO MID 60S ELSEWHERE.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 130 PM FRIDAY...
VFR CONDITIONS WILL CONTINUE FOR MOST OF THE AFTERNOON AND EVEN
ACROSS MUCH OF THE AREA. A FEW SHOWERS AND STORMS WILL PROGRESS
FROM THE MOUNTAINS TOWARDS THE WESTERN PIEDMONT...BUT IT IS STILL
UNCERTAIN AS TO HOW FAR EAST THEY WILL INITIALLY MAKE IT AND/OR HOW
STRONG THEY WILL BE. KINT/KGSO SHOULD SEE SOME SHOWERS AND POSSIBLY
ISOLATED STORMS IN THE VICINITY OF THE TERMINALS BY 21-22Z. SHOWERS
AND STORMS WILL THEN CONTINUE EAST ACROSS CENTRAL NC THIS EVENING
AND TONIGHT ALONG A SURFACE TROUGH AND AHEAD OF A COLD FRONT
APPROACHING FROM THE WEST. IT IS POSSIBLE THAT THE COVERAGE OF
SHOWERS MAY INCREASE OVER THE CENTRAL PIEDMONT PRIOR TO
MIDNIGHT...BUT ANY ISOLATES STORMS RE NOT EXPECTED TO BE STRONG AT
THAT POINT. THUS..OUTSIDE OF THE HEAVIEST SHOWERS...VFR CONDITIONS
SHOULD PREVAIL.
THE SHOWERS WILL DIE OFF BY SUNRISE SATURDAY MORNING...BUT SHOULD
REDEVELOP BY MIDDAY SATURDAY AS THE COLD FRONT MOVES INTO THE
AREA...AND STRONG STORMS ARE POSSIBLE FROM KRDU EASTWARD DURING THE
AFTERNOON.
OUTLOOK...
WITH A LARGE UPPER TROUGH EXPECTED TO REMAIN OVER THE
EASTERN US THROUGH EARLY NEXT WEEK...PERIODS OF SHOWERS AND STORMS
WILL BE POSSIBLE EACH DAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...MWS/SMITH
SHORT TERM...
LONG TERM...
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
313 PM EDT FRI AUG 17 2012
.SYNOPSIS...
A STRONG COLD FRONT WILL TRAVERSE THE AREA TODAY ACCOMPANIED BY
SHOWERS AND THUNDERSTORMS. THE COLD FRONT WILL STALL OUT JUST
OFFSHORE NEW ENGLAND...AND EXTEND SOUTHWARD ALONG THE MID-ATLANTIC
PIEDMONT INTO SATURDAY. AN ANOMALOUS UPPER LEVEL TROUGH WILL
EVOLVE OVER THE EASTERN HALF OF THE NATION THROUGH EARLY NEXT
WEEK...RESULTING IN SLIGHTLY BELOW NORMAL TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
WEAKENING COLD FRONT PUSHING INTO CENTRAL PA THIS MORNING. MOST
AREAS ALONG THE ALLEGHENY FRONT SAW A FEW HOURS OF LIGHT TO
MODERATE RAIN SHOWERS. A FEW POCKETS OF MODERATE TO BRIEFLY HEAVY
RAINFALL HAVE SPROUTED ALONG THE FRONT...MOST CONCENTRATED IN THE
LAUREL HIGHLANDS WHERE OROGRAPHIC ENHANCEMENT HAS TAKEN
PLACE...ALONG WITH GREATER PROXIMITY TO DEEPER MOISTURE AND CAPES.
FAR SOUTHEAST PA MAY BE ABLE TO MUSTER A FEW TO SEVERAL HUNDRED
J/KG*2 CAPES THIS AFTERNOON...WITH SOME T BECOMING EMBEDDED IN THE
MAIN LINE AND PERHAPS ISOLATED CELLS FORMING AHEAD OF THE LINE.
SEVERE THREAT REMAINS LOW HOWEVER. WITH THE FRONT TAKING ITS TIME
CROSSING THE CENTRAL MOUNTAINS THIS AFTERNOON... RAIN MAY NOT REACH
FAR SOUTHEAST COUNTIES UNTIL EARLY EVENING. LATEST HRRR UPDATE
VIA COSPA DEPICTS SLOW INTENSIFICATION OF THE CURRENT LINE OF
SHOWERS AS IT EXITS THE CENTRAL MOUNTAINS AND HEADS INTO THE LOWER
SUSQUEHANNA RIVER VALLEY THIS EVENING.
MUCH DRIER AIR WILL BE DIRECTED INTO THE AREA IN THE WAKE OF THE
COLD FRONT TONIGHT AND EARLY SATURDAY...WITH PCPN ENDING ACRS THE N/W
HALF OF THE CWA THIS EVE. AS THE CLOSED LOW BECOMES NEARLY STATIONARY
OVER JAMES BAY..THE COLD FRONT WILL SLOW ITS EWD PROGRESSION AND
REMAIN A FOCUS FOR SHOWERS/ISOLD TSTMS ACRS THE SERN 1/2 OF THE
CWA THRU LATE TNT AND ERLY SAT.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
BROAD CYC FLOW ALOFT WILL DOMINATE THE UPPER LEVEL PATTERN FOR THE
FORESEEABLE FUTURE WITH DRIER LLVL AND QUITE COMFORTABLE STRETCH
OF WEATHER EXPECTED ACROSS THE REGION THROUGH THE WEEKEND AND MUCH
OF NEXT WEEK. SHOWERS WILL EXIT MY SOUTHEAST COUNTIES AROUND 12Z
SAT WITH IMPROVING CONDS SLATED BY AFTERNOON THANKS TO WEAK HIGH
PRESSURE BUILDING OVER CENTRAL PA.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
MDL DATA INDICATES THE DEVELOPING UPPER-LEVEL TROUGH OVER ERN
NORTH AMERICA WILL UNDERGO ADDITIONAL AMPLIFICATION SUN-MON...AS
ENERGY DROPS SWD FM THE NRN PLAINS AND DIGS/SHARPENS THE TROUGH.
THE 12Z OPERATIONAL GFS AND ECMWF FORM A WEAK SFC LOW OVR THE SRN
MID-ATLC COAST BY MON. WENT WITH LOW-END CHC POPS...MAINLY FM
LATE SUNDAY INTO THE DAY ON MONDAY.
12Z GEFS SHOWS 500MB HEIGHTS OF -1 TO -2SD THROUGH THE MIDDLE OF
NEXT WEEK...WHICH WILL KEEP TEMPERATURES COOLER THAN NORMAL.
THE UPPER-LEVEL TROUGH WILL GRADUALLY LIFT NORTHWARD LATE IN THE
WEEK...ALLOWING THE FLOW TO BECOME MORE ZONAL. RISING HEIGHTS AND
RETURN FLOW SHOULD ALLOW FOR A MODERATION IN TEMPS BACK TO AT
LEAST SEASONAL NORMALS BY THE END OF NEXT WEEK.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
LINE OF SHOWERS PRESSING EASTWARD THIS AFTERNOON AND EVENING WITH
EMBEDDED ISOLATED T OVER SOUTHEASTERN PA TERMINALS. LEFT MENTION
OF T OUT GIVEN LOW PROB AT ANY GIVEN AIRFIELD. SHOWERS WILL END
THIS EVENING OVER THE WEST AND EARLY SAT MORNING ACROSS THE
SOUTHEAST.
COLD ADVECTION AND CYCLONIC FLOW ALOFT COUPLED WITH LOW LEVEL
MOISTURE LEFT OVER FROM TODAYS PRECIPITATION WILL LIKELY SPELL
SOME OVERNIGHT STRATUS AND FOG OVERNIGHT NIGHT WITH MVFR
CONDITIONS...AND SOME IFR IN THE NORTHERN AND WESTERN MOUNTAINS.
DRIER AND COOLER AIR WORKS IN FOR THE WEEKEND...AND EARLY NEXT WEEK.
OUTLOOK...
SAT-TUE...MAINLY VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR
LONG TERM...EVANEGO
AVIATION...JUNG/DEVOIR/TYBURSKI
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
253 PM EDT FRI AUG 17 2012
.SYNOPSIS...
A STRONG COLD FRONT WILL TRAVERSE THE AREA TODAY ACCOMPANIED BY
SHOWERS AND THUNDERSTORMS. THE COLD FRONT WILL STALL OUT JUST
OFFSHORE NEW ENGLAND...AND EXTEND SOUTHWARD ALONG THE MID-ATLANTIC
PIEDMONT INTO SATURDAY. AN ANOMALOUS UPPER LEVEL TROUGH WILL
EVOLVE OVER THE EASTERN HALF OF THE NATION THROUGH EARLY NEXT
WEEK...RESULTING IN SLIGHTLY BELOW NORMAL TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
WEAKENING COLD FRONT PUSHING INTO CENTRAL PA THIS MORNING. MOST
AREAS ALONG THE ALLEGHENY FRONT SAW A FEW HOURS OF LIGHT TO
MODERATE RAIN SHOWERS. A FEW POCKETS OF MODERATE TO BRIEFLY HEAVY
RAINFALL HAVE SPROUTED ALONG THE FRONT...MOST CONCENTRATED IN THE
LAUREL HIGHLANDS WHERE OROGRAPHIC ENHANCEMENT HAS TAKEN
PLACE...ALONG WITH GREATER PROXIMITY TO DEEPER MOISTURE AND CAPES.
FAR SOUTHEAST PA MAY BE ABLE TO MUSTER A FEW TO SEVERAL HUNDRED
J/KG*2 CAPES THIS AFTERNOON...WITH SOME T BECOMING EMBEDDED IN THE
MAIN LINE AND PERHAPS ISOLATED CELLS FORMING AHEAD OF THE LINE.
SEVERE THREAT REMAINS LOW HOWEVER. WITH THE FRONT TAKING ITS TIME
CROSSING THE CENTRAL MOUNTAINS THIS AFTERNOON... RAIN MAY NOT REACH
FAR SOUTHEAST COUNTIES UNTIL EARLY EVENING. LATEST HRRR UPDATE
VIA COSPA DEPICTS SLOW INTENSIFICATION OF THE CURRENT LINE OF
SHOWERS AS IT EXITS THE CENTRAL MOUNTAINS AND HEADS INTO THE LOWER
SUSQUEHANNA RIVER VALLEY THIS EVENING.
MUCH DRIER AIR WILL BE DIRECTED INTO THE AREA IN THE WAKE OF THE
COLD FRONT TONIGHT AND EARLY SATURDAY...WITH PCPN ENDING ACRS THE N/W
HALF OF THE CWA THIS EVE. AS THE CLOSED LOW BECOMES NEARLY STATIONARY
OVER JAMES BAY..THE COLD FRONT WILL SLOW ITS EWD PROGRESSION AND
REMAIN A FOCUS FOR SHOWERS/ISOLD TSTMS ACRS THE SERN 1/2 OF THE
CWA THRU LATE TNT AND ERLY SAT.
&&
.SHORT TERM /SATURDAY/...
BROAD CYC FLOW ALOFT WILL DOMINATE THE UPPER LEVEL PATTERN FOR THE
FORESEEABLE FUTURE WITH DRIER LLVL AND QUITE COMFORTABLE STRETCH
OF WEATHER EXPECTED ACROSS THE REGION THROUGH THE WEEKEND AND MUCH
OF NEXT WEEK. SHOWERS WILL EXIT MY SOUTHEAST COUNTIES AROUND 12Z
SAT WITH IMPROVING CONDS SLATED BY AFTERNOON THANKS TO WEAK HIGH
PRESSURE BUILDING OVER CENTRAL PA.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
MDL DATA INDICATES THE DEEP UPPER LEVEL TROUGH WILL UNDERGO
ADDITIONAL AMPLIFICATION SUN-MON...AS SECONDARY S/W DROPS SWD FM
THE NRN PLAINS AND DIGS/SHARPENS THE TROUGH INTO THE LWR MS/TN
VLYS. IN RESPONSE TO HEIGHT FALLS AND ENHANCED UPPER LEVEL
DIVERGENCE VIA STRENGTHENING RT ENTRANCE REGION JET DYNAMICS...THE
ECMWF/CANADIAN FORM A LOW OVR THE SRN MID-ATLC COAST BY 12Z MON.
THE GFS HINTS AT THIS IDEA BUT IS NOT AS WELL-DEVELOPED WITH ITS
SFC LOW. CONSENSUS BLEND SUPPORTS LOW-END CHC POPS MAINLY FM SUN
NGT INTO THE DAY ON MONDAY.
THE HIGH-AMPLITUDE UPPER TROUGH EAST OF THE MS RIVER WILL REMAIN
Q-STNRY AND SLOWLY DEAMPLIFY INTO THE SECOND HALF OF THE PD TUE-
THURS. THIS PD SHOULD FEATURE MAINLY FAIR/DRY WEATHER WITH SFC
HIGH PRES IN CONTROL. RISING HEIGHTS AND GRADUAL RETURN FLOW WILL
LKLY ALLOW FOR A MODERATION IN TEMPS BACK TO AT LEAST SEASONAL
NORMALS...IF NOT ABOVE NORMAL.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
LINE OF SHOWERS PRESSING EASTWARD THIS AFTERNOON AND EVENING WITH
EMBEDDED ISOLATED T OVER SOUTHEASTERN PA TERMINALS. LEFT MENTION
OF T OUT GIVEN LOW PROB AT ANY GIVEN AIRFIELD. SHOWERS WILL END
THIS EVENING OVER THE WEST AND EARLY SAT MORNING ACROSS THE
SOUTHEAST.
COLD ADVECTION AND CYCLONIC FLOW ALOFT COUPLED WITH LOW LEVEL
MOISTURE LEFT OVER FROM TODAYS PRECIPITATION WILL LIKELY SPELL
SOME OVERNIGHT STRATUS AND FOG OVERNIGHT NIGHT WITH MVFR
CONDITIONS...AND SOME IFR IN THE NORTHERN AND WESTERN MOUNTAINS.
DRIER AND COOLER AIR WORKS IN FOR THE WEEKEND...AND EARLY NEXT WEEK.
OUTLOOK...
SAT-TUE...MAINLY VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR
LONG TERM...
AVIATION...DEVOIR/TYBURSKI
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
135 PM EDT FRI AUG 17 2012
.SYNOPSIS...
A STRONG COLD FRONT WILL TRAVERSE THE AREA TODAY ACCOMPANIED BY
SHOWERS AND THUNDERSTORMS. THE COLD FRONT WILL STALL OUT JUST
OFFSHORE NEW ENGLAND...AND EXTEND SOUTHWARD ALONG THE MID-ATLANTIC
PIEDMONT INTO SATURDAY. AN ANOMALOUS UPPER LEVEL TROUGH WILL
EVOLVE OVER THE EASTERN HALF OF THE NATION THROUGH EARLY NEXT
WEEK...RESULTING IN SLIGHTLY BELOW NORMAL TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
WEAKENING COLD FRONT PUSHING INTO MY NORTHWEST COUNTIES LATE THIS
MORNING. A FEW HOURS OF LIGHT TO MODERATE RAIN SHOWERS ARE ALL
THIS SYSTEM CAN MUSTER TO THIS POINT...AND EXPECT THAT TO BE THE
CASE IN THE SFC HEATING CHALLENGED ENVIRONMENT ACROSS CENTRAL PA
AS WELL. FAR SOUTHEAST PA MAY BE ABLE TO MUSTER A FEW HUNDRED J OF
CAPE THIS AFTERNOON...WITH SOME T BECOMING EMBEDDED IN THE MAIN
LINE AND PERHAPS ISOLATED CELLS FORMING AHEAD OF THE LINE. SEVERE
THREAT REMAINS LOW HOWEVER...AND THE FRONT WILL TAKE ITS TIME
CROSSING THE CENTRAL MOUNTAINS THIS AFTERNOON. RAIN MAY NOT REACH
ALL OF MY SOUTHEASTERN COUNTIES BY 00Z SAT. AS PREVIOUSLY MENTIONED...
IF THE OUTLIER SOLUTION OF BETTER INSTABILITY WERE TO BE REALIZED...
THE CONVECTIVE ENVIRONMENT COULD CONCEIVABLY SUPPORT SEMI-
ORGANIZED STRUCTURES WITH PERHAPS A MIX OF PULSE AND MULTICELL
STORM MODES. THE BEST CHC FOR STG STORMS IS LKLY OVR THE ERN 1/2
OF THE CWA GIVEN LESS CLOUDS/BETTER HEATING. LATEST HRRR UPDATE
VIA COSPA DEPICTS SLOW INTENSIFICATION OF THE CURRENT LINE OF
SHOWERS AS IT CROSSES THE CENTRAL MOUNTAINS EARLY THIS
AFTERNOON...AND APPROACHES THE LOWER SUSQ LATE THIS AFTERNOON AND
EVENING.
MUCH DRIER AIR WILL BE DIRECTED INTO THE AREA IN THE WAKE OF THE
COLD FRONT...WITH PCPN ENDING ACRS THE N/W HALF OF THE CWA BY LATE
AFTN/EARLY EVE. AS THE CLOSED LOW BECOMES NEARLY STATIONARY OVER
JAMES BAY..THE COLD FRONT WILL SLOW ITS EWD PROGRESSION AND REMAIN
A FOCUS FOR SHOWERS/ISOLD TSTMS ACRS THE SERN 1/2 OF THE CWA THRU
TNT. THE 17/00Z MDLS SHOW ONE OR MORE WAVES DEVELOPING ALONG THE
FNT AS IT SLOWS DOWN OVR ERN PA. THE NAM IS THE MOST AGGRESSIVE
WITH THIS FEATURE FOLLOWED BY THE CANADIAN. THE 00Z GFS IS MORE
PROGRESSIVE AND LOOKS SIMILAR TO THE UKMET/ECMWF. THEREFORE HAVE
INCREASED POPS INTO LKLY RANGE FOR THE FAR SE ZONES AFT 00Z.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
THE LG SCALE PATTERN WILL CONTINUE TO BE DOMINATED BY BROAD CYC
FLOW ALOFT ASSOCD WITH DEEP UPPER LEVEL TROUGH EXPANDING OVER THE
ERN CONUS...WITH HEIGHTS FCST TO REACH 3 SD BELOW NORMAL AT 500MB
OVER THE MS/OH VLYS. MUCH OF THE REGION WILL BE UNDER THE
INFLUENCE OF RELATIVELY COOL AND ABNORMALLY DRY SFC HIGH PRES
CENTERED OVR THE SRN GRT LKS/MIDWEST. THE FORECAST CHALLENGE FOR
D2 REVOLVES AROUND THE SLOWING/STALLING COLD FRONT OVR THE MID-
ATLC PIEDMONT...WHICH SHOULD SLOWLY DRIFT EWD TO THE COAST BY THE
END OF THE PD. THE NAM/GEM CONTINUE TO BE NORTH OF OTHER SOLUTIONS
AND KEEP PCPN GOING OVR SE PA INTO SAT EVE. WILL EMPLOY A MIDDLE
GROUND APPROACH AND KEEP LOW POPS GOING ACRS THE FAR SERN ZONES
THRU THE FIRST HALF OF D2. FCST TEMPS WILL AVG BELOW NORMAL ON
SAT.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
MDL DATA INDICATES THE DEEP UPPER LEVEL TROUGH WILL UNDERGO
ADDITIONAL AMPLIFICATION SUN-MON...AS SECONDARY S/W DROPS SWD FM
THE NRN PLAINS AND DIGS/SHARPENS THE TROUGH INTO THE LWR MS/TN
VLYS. IN RESPONSE TO HEIGHT FALLS AND ENHANCED UPPER LEVEL
DIVERGENCE VIA STRENGTHENING RT ENTRANCE REGION JET DYNAMICS...THE
ECMWF/CANADIAN FORM A LOW OVR THE SRN MID-ATLC COAST BY 12Z MON.
THE GFS HINTS AT THIS IDEA BUT IS NOT AS WELL-DEVELOPED WITH ITS
SFC LOW. CONSENSUS BLEND SUPPORTS LOW-END CHC POPS MAINLY FM SUN
NGT INTO THE DAY ON MONDAY.
THE HIGH-AMPLITUDE UPPER TROUGH EAST OF THE MS RIVER WILL REMAIN
Q-STNRY AND SLOWLY DEAMPLIFY INTO THE SECOND HALF OF THE PD TUE-
THURS. THIS PD SHOULD FEATURE MAINLY FAIR/DRY WEATHER WITH SFC
HIGH PRES IN CONTROL. RISING HEIGHTS AND GRADUAL RETURN FLOW WILL
LKLY ALLOW FOR A MODERATION IN TEMPS BACK TO AT LEAST SEASONAL
NORMALS...IF NOT ABOVE NORMAL.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AREA OF RAIN SHOWERS ASSOCIATED WITH A COLD FRONT MOVING THROUGH
THE REGION CURRENTLY STRETCHES FROM KBFD SOUTH THROUGH KJST AND
KAOO. SOME HEAVIER SHOWERS BEGINNING TO SHOW UP ON RADAR SOUTH OF
KAOO BUT NO LIGHTNING OCCURING.
EXPECT THE LINE OF SHOWERS TO PROGRESS EAST THROUGH THE LATE
AFTERNOON. ANY CONVECTION SHOULD BE CONFINED TO THE SOUTHEAST
PORTION OF THE STATE THIS AFTERNOON. LEFT THE MENTION OF TSRA OUT
OF ALL BUT KMDT AND KLNS FOR THE REMAINDER OF THE INTIAL PERIOD.
COLD ADVECTION AND CYCLONIC FLOW ALOFT COUPLED WITH LOW LEVEL
MOISTURE LEFT OVER FROM TODAYS PRECIPITATION WILL LIKELY SPELL
SOME OVERNIGHT STRATUS AND FOG FRIDAY NIGHT WITH MVFR
CONDITIONS...AND SOME IFR IN THE NORTHERN AND WESTERN MOUNTAINS.
DRIER AND COOLER AIR WORKS IN FOR THE WEEKEND...AND EARLY NEXT WEEK.
OUTLOOK...
SAT-TUE...MAINLY VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...DEVOIR/STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...STEINBUGL
AVIATION...JUNG/TYBURSKI
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
312 PM CDT FRI AUG 17 2012
.SHORT TERM...
FOR THIS AFTERNOON INTO THIS EVENING...HAVE RAISED POPS A LITTLE
THROUGH THE REST OF THE CONCHO VALLEY. HIGH RESOLUTION RAP SOLUTION
HAS CONVECTION ACROSS THE CONCHO VALLEY THROUGH THE AFTERNOON AND
THEN DEVELOPS MORE CONVECTION ACROSS THE BIG COUNTRY. THE RAP HAS
MORE BROAD CONVECTION ACROSS THE AREA WHILE THE TEXAS TECH 3KM WRF HAS
THE ACTIVITY TOO FAR NORTH. TAKING A LOOK AT SHOWERS AND
THUNDERSTORMS THAT ARE ALREADY FORMING...THE HIGH RESOLUTION RAP MODEL
LOOKS TO BE A BETTER SOLUTION. HAVE NOT CHANGED MUCH THROUGH THE
REST OF TONIGHT AND TOMORROW. MOST OF ACTIVITY LOOKS TO BE
SCATTERED AS IT WILL BE DRIVEN BY MESOSCALE PROCESSES.
REIMER
.LONG TERM...
PRECIPITATION CHANCES WILL CONTINUE THROUGH THE FIRST PART OF THE
EXTENDED FORECAST. A WEAK COLD FRONT THAT IS CURRENTLY STALLED
ACROSS WEST CENTRAL TEXAS WILL REMAIN IN THE VICINITY OF THE AREA
AND BECOME FAIRLY DIFFUSE BY LATE SATURDAY. REGARDLESS...THE FRONT
WILL SERVE AS A FOCUS FOR CONTINUED SHOWERS AND THUNDERSTORMS ACROSS
ALL OF THE REGION SATURDAY NIGHT. SATURDAY...A SHORTWAVE TROUGH WILL
SWING ACROSS THE PLAINS...ALONG THE SOUTHERN PERIPHERY OF THE MAIN
UPPER LEVEL TROUGH THAT IS FORECAST TO BE LOCATED OVER THE MIDWEST.
THIS WILL SEND A REINFORCING SHOT OF SURFACE HIGH PRESSURE DOWN THE
PLAINS AND INTO WEST CENTRAL TEXAS ON SUNDAY. THIS WILL RESULT IN
DECREASING RAIN CHANCES FROM NORTH TO SOUTH THROUGHOUT THE DAY
SUNDAY. I COOLED HIGH TEMPERATURES SUNDAY BY A DEGREE OR TWO...GIVEN
THE EXPECTED CLOUD COVER AND RAINFALL...AND THESE MAY NEED TO
EVENTUALLY BE LOWERED EVEN MORE. SUNDAY NIGHT...RAIN CHANCES WILL BE
CONFINED TO THE CONCHO VALLEY AND AREAS TO THE SOUTH. ALTHOUGH A FEW
STRONG TO SEVERE THUNDERSTORMS WILL BE POSSIBLE SATURDAY NIGHT
THROUGH SUNDAY...THE MAIN THREAT IS THE POTENTIAL FOR LOCALLY HEAVY
RAINFALL.
BEYOND SUNDAY...A SLOW WARMING TREND IS EXPECTED...WITH TEMPERATURES
BACK INTO THE MID 90S BY MID WEEK. MODELS ARE STILL INDICATING A
DISTURBANCE EMBEDDED IN THE NORTHWEST FLOW ALOFT...DROPPING THROUGH
THE TEXAS PANHANDLE MONDAY NIGHT OR TUESDAY. THIS WILL LIKELY RESULT
IN AN MCS DEVELOPING ACROSS THE PANHANDLE AND THEN MOVING SOUTHEAST.
AT THIS TIME...CONFIDENCE IS NOT HIGH ENOUGH IN THIS FEATURE
REACHING WEST CENTRAL TEXAS...SO I HAVE LEFT POPS BELOW 15 PERCENT.
DANIELS
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 73 95 71 90 68 / 40 50 50 30 10
SAN ANGELO 74 95 72 91 69 / 30 40 50 40 20
JUNCTION 74 97 72 92 70 / 20 30 40 40 20
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
REIMER/20/DANIELS
AREA FORECAST DISCUSSION...UPDATED
NWS SAN ANGELO TX
1213 PM CDT FRI AUG 17 2012
.DISCUSSION...
SEE 18Z AVIATION DISCUSSION BELOW.
&&
.AVIATION...
WE WILL SEE VFR CONDITIONS THROUGH THE EARLY AFTERNOON ACROSS THE
AREA. WE STILL EXPECT TO SEE SCATTERED THUNDERSTORMS DEVELOP ALONG
A MESOSCALE BOUNDARY NEAR THE KABI TERMINAL. HOWEVER...THESE
THUNDERSTORMS ARE NOT SUPPOSED TO AFFECT SOUTHERN AREAS UNTIL
LATER ON TONIGHT. MORE WIDESPREAD COVERAGE IS EXPECTED FOR
TOMORROW...HOWEVER...THIS WILL BE SOMEWHAT DEPENDENT ON WHAT
HAPPENS ACROSS THE AREA TONIGHT...AND SO WILL HOLD OFF ON
MENTIONING WX SPECIFICALLY AT ANY ONE SITE FOR NOW...AND INSTEAD
MAY OPT FOR TSRA IN THE VICINITY OF TERMINALS UNTIL MORE
CERTAINTY ON LOCATION IS GAINED. OTHERWISE...WINDS WILL REMAIN OUT
OF THE SOUTH THROUGH THE NEXT 24 HOURS AS THE FRONT WILL NOT BE
ABLE TO PUSH THROUGH THE REGION UNTIL SUNDAY. 20
&&
.PREV DISCUSSION... /ISSUED 637 AM CDT FRI AUG 17 2012/
UPDATE...
SEE 12Z AVIATION DISCUSSION BELOW.
AVIATION...
VFR CONDITIONS SHOULD PREVAIL ACROSS WEST CENTRAL TEXAS TERMINALS
WELL INTO THE AFTERNOON...BEFORE THUNDERSTORMS BEGIN TO DEVELOP
AND CONDITIONS MAY DETERIORATE. MOST LIKELY LOCATION FOR STORMS
WILL BE ACROSS THE BIC COUNTRY...AND HAVE ADDED A VCTS FOR THE
KABI TERMINAL FOR NOW. FARTHER SOUTH...JUST TOO MUCH UNCERTAINTY
ON TIMING AND PLACEMENT OF STORM TO WARRANT A MENTION...BUT
CONDITIONS WILL CERTAINLY NEED TO BE MONITORED.
PREV DISCUSSION... /ISSUED 406 AM CDT FRI AUG 17 2012/
SHORT TERM...
SCATTERED MID LEVEL SHOWERS CONTINUE TO DEVELOP ACROSS PORTIONS OF
THE BIG COUNTRY AND RED RIVER VALLEY EARLY THIS MORNING. ABUNDANT
MID LEVEL MOISTURE COMBINING WITH A LOW LEVEL JET OF 25 TO 30 KTS.
ITS ABOUT THIS TIME THAT CONVECTION EXPANDED YESTERDAY...AND EVEN
WITHOUT THE STRONGER SHORTWAVE THAT WE HAD PASSING...WOULD NOT BE
SURPRISED TO SEE CONVECTIVE COVERAGE EXPAND A LITTLE MORE AT SUNRISE
THIS MORNING AS WELL.
SURFACE FRONTAL BOUNDARY DROPPING THROUGH OKLAHOMA THIS
MORNING...AND SEEMS TO HAVE A DECENT PUSH WITH IT SO FAR.
OBSERVATIONS ARE SHOWING SOME 15 TO 20 KT NORTHEAST WINDS....WITH
DEWPOINTS IN THE 40S AND LOWER 50S. LATEST RUC AS WELL AS THE 4KM
WRF MODEL FROM TEXAS TECH...SHOW THIS BOUNDARY MAKING IT WELL INTO
WEST CENTRAL TEXAS TODAY. IF THIS DOES HAPPEN...THEN CONVECTION WILL
END UP FARTHER SOUTH THAN WE ORIGINALLY THOUGHT. THUS...HAVE BOOSTED
THE POPS ACROSS THE CENTRAL COUNTIES...ROUGHLY BETWEEN ABILENE AND
SAN ANGELO...A LITTLE. THIS ACTIVITY WILL CONTINUE INTO THE
EVENING HOURS.
TONIGHT...MODELS SHOW A STRONGER SHORTWAVE MOVING TOWARDS WEST
CENTRAL TEXAS IN THE NORTHWEST FLOW ALOFT. COMBINE THIS WAVE WITH
WHATS LEFT OF THE SURFACE BOUNDARY...AND EXPECT SCATTERED CONVECTION
TO CONTINUE. WITH THE LOW LEVEL JET STRONGER TONIGHT...BEST POPS
WILL SHIFT A LITTLE TO NORTH OF THE BOUNDARY.
LONG TERM...
LOOKS LIKE A WET PATTERN SETTING UP THIS WEEKEND ACROSS WEST CENTRAL
TEXAS. BENEFICIAL RAINFALL IS NEEDED AS MUCH OF THE CWFA IS
CURRENTLY EXPERIENCING MODERATE TO SEVERE DROUGHT CONDITIONS(AS OF
AUGUST 14)...ACCORDING TO THE US DROUGHT MONITOR. THE MAIN PLAYERS
WILL BE A SLOW MOVING COOL FRONT...OTHER MESOSCALE BOUNDARIES IN THE
AREA AND WEAK UPPER LEVEL FORCING. ALSO...SLOW MOVING STORMS AND
PWAT VALUES OF 1.5 TO 2 INCHES WILL BRING LOCALLY HEAVY RAINFALL.
LOOKS LIKE RAINFALL AMOUNTS WILL AVERAGE 0.5 TO 1.5 INCHES...WITH
LOCALLY HIGHER AMOUNTS POSSIBLE...ESPECIALLY ACROSS THE NORTHERN AND
EASTERN CWFA. ALSO...AN ISOLATED SEVERE STORM OR TWO ARE POSSIBLE
ACROSS THE BIG COUNTRY MAINLY SATURDAY AFTERNOON AND EVENING. THE
MAIN HAZARDS WILL BE LARGE HAIL AND DAMAGING WINDS. THE ABUNDANT
CLOUD COVER AND RAINFALL WILL KEEP TEMPERATURES DOWN SATURDAY AND
SUNDAY. HIGHS WILL BE IN THE UPPER 80S TO MID 90S.
LOOKS LIKE MAINLY DRY WEATHER RETURNING NEXT WEEK AS THE UPPER LEVEL
RIDGE BUILDS BACK OVER THE AREA. THE GFS MODEL IS STILL INDICATING A
POSSIBLE MCS MOVING SOUTHEAST ACROSS THE SOUTHERN PLAINS MONDAY
NIGHT AND TUESDAY MORNING. WILL KEEP THE FORECAST DRY FOR
NOW...HOWEVER WILL NEED TO MONITOR FUTURE MODEL OUTPUT. HIGHS WILL
WARM BACK INTO THE MID 90S EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 95 72 94 71 90 / 40 40 50 50 40
SAN ANGELO 100 75 95 71 92 / 20 30 40 40 30
JUNCTION 96 74 96 72 94 / 10 20 30 30 30
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
337 PM EDT FRI AUG 17 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTHEAST CROSS THE REGION THIS EVENING
INTO TONIGHT ACCOMPANIED BY SHOWERS AND THUNDERSTORMS. DEEPENING
LOW PRESSURE...ANCHORED OVER SOUTHEAST CANADA...WILL EVOLVE ACROSS
THE EASTERN U.S. FOR THE WEEKEND INTO THE FIRST HALF OF NEXT WEEK.
A SERIES OF DISTURBANCES EMBEDDED WITHIN THE UPPER LOW WILL KEEP
UNSETTLED...SHOWERY...CLOUDY...COOL CONDITIONS ACROSS MUCH OF THE
AREA UNTIL TUESDAY...WHEN DRIER CONDITIONS ALONG WITH SEASONABLE
TEMPERATURES ARE EXPECTED.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS 310 PM EDT FRIDAY...
SFC COLD FRONT LOCATED TO OUR WEST FROM WESTERN PENNSYLVANIA
SOUTHWARD TO EASTERN KY. THIS FRONT WILL MOVE SOUTHEAST TONIGHT INTO
SATURDAY. CONVECTION COVERAGE SHOULD INCREASE LATE THIS AFTERNOON
INTO TONIGHT...DUE TO COMBINATION OF DIFFERENTIAL HEATING EFFECTS
AND THE APPROACH OF COLD FRONT/MID-LEVEL SHORT WAVE TROUGH. AT THIS
TIME...REGIONAL WSR-88D IMAGES SHOWED SHOWERS AND ISOLATED
THUNDERSTORMS MOVING EAST ACROSS WESTERN PORTIONS OF CWA. LOOKS LIKE
THE BEST INSTABILITY IS JUST AHEAD OF THE CLOUD DECK. SPC RECENTLY
REMOVED MUCH OF THE AREA FROM THEIR SLIGHT RISK...AND THIS SEEMS
REASONABLE...ESPECIALLY IN LIGHT OF THE WEAK SHEAR OVER THE REGION.
AN ISOLATED STRONG TO SEVERE THUNDERSTORM MAY BE POSSIBLE THIS
EVENING WITH MAIN THREAT HEAVY RAINS AND GUSTY WINDS.
THUNDERSTORMS AND SHOWERS SHOULD WANE/DIMINISH TONIGHT AS THE
UPPER SHORT WAVE SHEARS OUT AND THE MAIN DYNAMICS MOVE TOWARD NEW
ENGLAND. ANOTHER SHORTWAVE POISED THE MOVE ACROSS THE UPPER
MIDWEST/NORTHERN PLAINS OVERNIGHT...WILL PROLONG SW FLOW ALOFT AND
DELAY ANY CLEARING. WITH PLENTY OF CLOUDS TONIGHT...PLAYED LOW
TEMPERATURES CLOSE TO THE ADJMET WITH READINGS FROM AROUND 60
DEGREES IN THE MOUNTAINS TO THE UPPER 60S TO NEAR 70 IN THE
SOUTHEAST.
THE COLD FRONT WILL MOVE SOUTH INTO NORTH CAROLINA FOR SATURDAY.
THERE IS ENOUGH MOISTURE TO COMBINED WITH WEAK UPPER LEVEL
DISTURBANCES AND SURFACE WIND CONVERGENCE TO PRODUCE SHOWERS AND A
FEW THUNDERSTORMS. HIGH TEMPERATURES ON SATURDAY WILL VARY THE MID
70S IN THE MOUNTAINS TO THE MID 80S IN THE SOUTHEAST.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 320 PM EDT FRIDAY...
COLD FRONT WILL BE DOWN IN THE CAROLINAS BY SAT NIGHT WITH DRIER AND
COOLER AIR SEEPING SOUTHBOUND ALLOWING FOR AN EXODUS OF MOST
LEFTOVER SHRA OVER THE SOUTH SAT EVENING. NEXT MID LEVEL IMPULSE
PROGGED BY MOST MODELS WILL ROUND THE 5H TROF SLIDING THRU THE UPPER
MIDWEST SUNDAY AND DAMPEN UPON PASSING INTO THE OHIO VALLEY SUNDAY
NIGHT. DEEPER MOISTURE WITH THE RESIDUAL FRONT LOOKS TO REMAIN JUST
SOUTH OF THE CWA THOUGH AS OVERALL MID LEVEL BACKING OF THE FLOW
AHEAD OF THE WAVE APPEARS WEAK ATTM. HOWEVER WITH LOW LEVEL
TRAJECTORIES TURNING MORE SOUTH/SE AND A RIBBON OF HIGHER SFC-85H
THETA-E SPREADING ALONG/EAST OF THE BLUE RIDGE...WENT AHEAD AND
EXPANDED THE CHANCE POPS NORTH SUNDAY/SUNDAY EVENING...WITH BEST
COVERAGE SOUTHERN HALF WHERE SOME CAPE WILL EXIST. SHRA MAY LINGER
EAST SUNDAY NIGHT AND BUBBLE BACK TO THE WEST ON MONDAY AS YET
ANOTHER UPPER LEVEL DISTURBANCE SPINS BY AND PERHAPS INDUCES A SFC
WAVE ALONG THE FRONT TO THE SOUTH MONDAY AFTERNOON PER THE LASTEST
CANADIAN. AGAIN MAINLY MIDDLE RANGE CHANCE POPS FOR NOW GIVEN
UNCERTAINTY AND ONLY SLIGHT POPS FAR WEST/NW WHERE REMOVED FROM THE
DEEPER RH. OTRW MORE CLOUDS SOUTH/EAST AND PERHAPS MORE
BREAKS/CLEARING AT TIMES NORTH-NW THRU MONDAY. CLOUDS/SHRA SHOULD
KEEP HIGHS MAINLY IN THE 70S TO LOW 80S WITH LOWS 50S TO LOW 60S
MOUNTAINS...AND 60-65 BEHIND THE FRONT OUT EAST.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 1215 PM EDT FRIDAY...
UPPER TROF ACROSS THE EAST WILL GRADUALLY WEAKEN AND START TO LIFT
OUT BY LATE IN THE WEEK AS WEAK SURFACE HIGH PRESSURE REMAINS IN
PLACE. HOWEVER MODELS SUGGEST THAT A 5H IMPULSE ROTATING AROUND THE
DEPARTING TROFFINESS THRU THE MID MISS VALLEY...COULD EVOLVE INTO A
WEAK UPPER LOW BY MID WEEK WHICH MAY SLIP EAST INTO THE CENTRAL
APPALACHIANS BY FRIDAY. THIS QUITE UNCERTAIN AND MAINLY SUPPORTED BY
THE LATEST ECMWF...BUT WOULD BE ENOUGH TO LIKELY ENHANCE CONVECTIVE
CHANCES LATER IN THE WEEK DESPITE WEAK RIDGING IN PLACE. OTRW TREND
IN THE OVERALL FORECAST REMAINS ON THE DRY SIDE WITH THE RESIDUAL
AXIS OF DEEPER MOISTURE STILL TO THE SE...AND CONTINUED DRIER NORTH
TO NE FLOW IN PLACE. THIS LOW LEVEL ONSHORE FLOW COULD BRING IN SOME
LOW CLOUDS TO ALONG THE BLUE RIDGE AT TIMES DURING THE OVERNIGHTS
BUT IFFY. OTRW INTERVALS OF CLOUDS AND SUN THRU THE PERIOD WITH MAINLY
DIURNALLY DRIVEN SLIGHT CHANCE CONVECTIVE POPS ESPCLY SW AND
MOUNTAINS WHERE AIDED BY LOCAL CONVERGENCE. COVERAGE PERHAPS A BIT
MORE LATE IN THE WEEK OVER THE SOUTH IF THE WEAK CUTOFF DEVELOPS AND
BETTER MOISTURE GETS RETURNED NORTH. TEMPS MAINLY PERSISTENCE THRU
THE PERIOD UNDER HIGH PRESSURE/LIGHT WINDS...AND ONLY SLIGHT WARMING
ALOFT...WITH HIGHS 70S TO ARND 80 MOUNTAINS AND LOW/MID 80S EAST.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
AS OF 105 PM EDT FRIDAY...
MAIN FOCUS FOR TAF VALID PERIOD IS CHANCE FOR CONVECTION THIS
AFTERNOON/EVENING. REGIONAL WSR-88D LOOP SHOWED SCATTERED SHOWERS
AND ISOLATED THUNDERSTORMS MOVING EAST ACROSS THE WESTERN MOUNTAINS.
LOOKS LIKE THE BEST INSTABILITY JUST IN FRONT OF THE CLOUD BLANKET.
COLD FRONT LOCATED TO OUR WEST ALONG THE OHIO RIVER WILL MOVE EAST
ACROSS OUR REGION WITH SCATTERED MVFR SHOWERS AND THUNDERSTORM.
LOCAL IFR CONDITIONS AND GUSTY WINDS POSSIBLE WITH A STRONGER
STORM. ACCORDING TO THE HRRR AND LOCAL WRFARW-RNK LOOKS LIKE THE
BEST CHANCE FOR A THUNDERSTORM MAY BE AT BLF OR DAN. HOWEVER
THUNDERSTORMS ARE POSSIBLE AT ALL TAF SITES THIS AFTERNOON INTO
TONIGHT WITH COLD FRONT MOVING ACROSS THE REGION.
ANOTHER CONCERN IS WHETHER OR NOT CLOUDS/PCPN WILL EXIT THE AREA...OR
BUILD BACK NORTHWARD OVERNIGHT IN WAKE OF INITIAL WAVE OF
SHRA/TSRA. KEPT MVFR CLOUDS-CIGS AND MVFR-IFR VSBYS IN -RA/-SHRA/-DZ AFT
08Z. THINKING IS THAT -SHRA WILL GENERALLY BE CONFINED TO PIEDMONT
REGION...BUT UPSLOPE FLOW AND PASSING WAVE ALONG FRONT TO THE
SOUTH COULD PROMOTE DEVELOPMENT OF LOW CLOUDS AND -DZ BLF-LWB AFT
08Z SAT. WINDS REMAIN W-NW THROUGH TAF VALID PERIOD...BUT WILL BE
VEERING OVER TO NE NEAR 12Z SAT...WHICH WILL FURTHER PROMOTE
DEVELOPMENT OF LOW CLOUDS AND FOG...ESPECIALLY ACROSS THE PIEDMONT
REGION.
EXTENDED AVIATION DISCUSSION...
THE FRONT SLOWS AND LINGERS ACROSS THE CAROLINAS THROUGH THE
WEEKEND...WHILE HIGH PRESSURE PASSES EASTWARD TO THE SOUTH OF THE
GREAT LAKES. EXPECT MOST OF THE AREA TO REMAIN DRY ON
SATURDAY...HOWEVER WIDELY SCATTERED SHOWERS AND THUNDERSTORMS WILL
DEVELOP MAINLY ACROSS THE MOUNTAINS WITH AFTERNOON HEATING FROM
SUNDAY INTO THE MIDDLE OF NEXT WEEK.
&&
.EQUIPMENT...
KFCX RADAR IS BACK UP AND RUNNING...BUT MAY GO DOWN AGAIN
TONIGHT. PROBLEMS WITH KLYSTRON BLOWER MOTOR. PARTS ON ORDER.
ESTIMATED REPLACEMENT OF PART AFTER DELIVERY ON SATURDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...KK/RAB
NEAR TERM...KK
SHORT TERM...JH
LONG TERM...JH
AVIATION...KK/RAB
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
124 PM EDT FRI AUG 17 2012
.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION THIS AFTERNOON ACCOMPANIED BY
SHOWERS AND THUNDERSTORMS INTO THIS EVENING. DEEPENING LOW
PRESSURE...ANCHORED OVER SOUTHEAST CANADA...WILL EVOLVE ACROSS THE
EASTERN U.S. FOR THE WEEKEND INTO THE FIRST HALF OF NEXT WEEK. A
SERIES OF DISTURBANCES EMBEDDED WITHIN THE UPPER LOW WILL KEEP
UNSETTLED...SHOWERY...CLOUDY...COOL CONDITIONS ACROSS MUCH OF THE
AREA UNTIL TUESDAY...WHEN DRIER CONDITIONS ALONG WITH SEASONABLE
TEMPERATURES ARE EXPECTED.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS 104 PM EDT FRIDAY...
REGIONAL WSR-88D IMAGES SHOWED SHOWERS AND ISOLATED THUNDERSTORMS
MOVING EAST INTO WESTERN PORTIONS OF CWA. CLOUD SHIELD SPREADING
EAST ACROSS THE WESTERN MOUNTAINS HINDER THUNDERSTORM DEVELOPMENT.
SWODY1 HAS BACK OFF ON SEVERE POTENTIAL WITH A SEE TEXT ACROSS OUR
REGION. ISOLATED STRONG TO SEVERE THUNDERSTORMS MAY STILL BE
POSSIBLE THIS AFTERNOON WITH COLD FRONT AND UPPER LEVEL VORT
ROTATING EAST ACROSS OUR AREA. ADJUSTED CLOUDS...TEMPERATURES AND
POPS FOR THIS AFTERNOON. MORE LATER THIS AFTERNOON...
AS OF 940 AM EDT FRIDAY...
LOW CLOUDS AND FOG ARE LIFTING AS HIGH CLOUDS SPREAD EAST INTO OUR
REGION. EXPECT SUFFICIENT HEATING COMBINED WITH LOW-LEVEL MOISTURE
INCREASE TO SUPPORT SCATTERED SHOWERS AND THUNDERSTORMS THIS AFTERNOON
INTO TONIGHT. SWODY1 HAS KEPT WESTERN PORTIONS OF CWA IN SLIGHT
RISK OF SEVERE FOR THIS AFTERNOON. THE MAIN THREAT IS FOR DAMAGING
WINDS. HRRR AND WRF-ARWRNK SHOWED CONVECTION STARTING AFTER 19Z
AND MOVES EAST INTO TONIGHT. MODIFIED CLOUD COVER AND POPS FOR
THIS MORNING INTO THIS AFTERNOON. ADJUSTED TEMPERATURES ACCORDING
TO LATEST OBS AND MODEL TRENDS. MADE A LITTLE COOLER IN THE WEST
WITH ADDITIONAL LOW CLOUDS THIS MORNING.
AS OF 500 AM EDT FRIDAY...
MAIN CONCERN THROUGH THE SHORT TERM WILL BE APPROACHING SHORT
WAVE...NOW LOCATED FROM THE EASTERN GREAT LAKES SWWD INTO OK/MO.
AN OVERNIGHT MCS ASSOCIATED WITH THIS TROUGH BACKBUILT
SOUTHWESTWARD INTO THE MID-SOUTH/LOWER MS VALLEY REGION...WITH
LITTLE TO NO ACTIVITY CURRENT EVIDENT FURTHER NORTH ACROSS THE OH
VALLEY. THIS SHORT WAVE WILL PROGRESS TOWARD THE MID-ATLANTIC BY
00Z AND EVOLVE INTO A DEEPENING AREA OF SEMI-PERMANENT UPPER LOW
PRESSURE ALOFT ACROSS SOUTHEAST CANADA THROUGH THE WEEKEND AND
INTO EARLY NEXT WEEK. IN SO DOING...DYNAMICS WILL WEAKEN AS THE
SYSTEM PROGRESSES TOWARD THE EAST COAST. EXTENSIVE MID-HIGH CLOUDS
HAVE SPREAD EASTWARD ACROSS THE OH VALLEY INTO PARTS OF WV EARLY
THIS MORNING...BUT THE LACK OF UPSTREAM CONVECTION SUPPORTS
CURRENT THINKING THAT ANTECEDENT CLOUD COVER ACROSS OUR CWA WILL
BE LIMITED ENOUGH TO ALLOW SUFFICIENT HEATING COMBINED WITH A SLOW
LOW-LEVEL MOISTURE INCREASE TO SUPPORT SCT SHRA/TSRA BY MID-DAY
THROUGH THE EVENING FROM W-E. SPC HAS OUTLOOKED THE ENTIRE CWA FOR
SLIGHT RISK FOR MULTI-CELL TSRA WITH SPOTTY MARGINAL HAIL AND
DAMAGING WINDS. MODEL PROGGED INSTABILITY IS WEAK AT BEST AND SHEAR
IS NIL...SO LOCAL THINKING IS THAT A 5 PERCENT RISK OF SEVERE MAY
BE SUFFICIENT TO COVER EXPECTED CONVECTIVE ACTIVITY TODAY. CERTAINLY
CANNOT RULE OUT A WARNING OR TWO DURING THE AFTERNOON/EARLY
EVENING...ESPECIALLY ACROSS THE SOUTHERN SHENANDOAH VALLEY...FAR
SOUTHWEST VA...AND NORTHERN PIEDMONT REGION. ACTIVITY SHOULD WANE
RATHER QUICKLY AFT 00Z AS THE UPPER SHORT WAVE SHEARS OUT AND THE
MAIN DYNAMICS MOVE TOWARD NEW ENGLAND. ALTHOUGH SHRA/TSRA ACTIVITY
SHOULD GENERALLY DISSIPATE ACROSS E/SE SECTIONS OF THE CWA AFT
06Z...EMBEDDED UPSTREAM SHORT WAVES...PARTICULARLY ONE POISED
ACROSS THE UPPER MIDWEST/NORTHERN PLAINS OVERNIGHT...WILL PROLONG
SW FLOW ALOFT AND DELAY ANY CLEARING DURING THE REMAINDER OF THE
NEAR TERM.
MAX TEMPS TODAY WILL BE PROBLEMATIC AND COULD EASILY VARY BY AS
MUCH AS 20F OR MORE FROM THE WV SIDE OF THE CWA TO THE SE PIEDMONT
REGION. EXTENSIVE MID-HIGH CLOUDS SHOULD SPREAD ACROSS AREAS
ALONG-W OF THE ALLEGHANYS EARLY ENOUGH IN THE DAY TO GREATLY LIMIT
DAYTIME HEATING ACROSS THOSE AREAS...WITH SHRA/TSRA DEVELOPING
WEST OF A ROA-HLX-HKY LINE BY 18Z. EAST OF THIS AREA...CLOUDS WILL
BE SLOWER TO ARRIVE WITH INITIAL SFC MOISTURE LIMITING EARLY CU
DEVELOPMENT. WITH 850MB TEMPS NEAR +18C BY AFTERNOON...ALBEIT 2C
COOLER THAN INDICATED ACROSS THAT REGION YESTERDAY...AREAS FROM
LYH-DAN EASTWARD COULD EASILY APPROACH 90 BY AFTERNOON.
THUS...HAVE MAX TEMPS RANGING FROM THE MID 70S SE WV TO AROUND DAN
AND POINTS EASTWARD. RADIATIONAL COOLING OVERNIGHT WILL BE MINIMAL
TO NONE WITH EXTENSIVE CLOUD COVER REMAINING IN PLACE. DEWPOINTS
WILL REMAIN IN THE 60S TO EVEN NEAR 70 ACROSS THE SE PIEDMONT
REGION. THUS...EXPECT MIN TEMPS TO GENERALLY BE AOA THIS MORNINGS
READINGS WITH LESS VARIATION NOTED...RANGING FROM THE LOW 60S
MOUNTAINS/SE WV TO NEAR 70 DAN AND POINTS EASTWARD.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
AS OF 430 AM THURSDAY...
ALTHOUGH THE COLD FRONT WILL REMAIN ACROSS NORTH CAROLINA FOR MOST
OF THE WEEKEND...ENOUGH MOISTURE WILL COMBINE WITH WEAK UPPER LEVEL
DISTURBANCES AND SURFACE WIND CONVERGENCE TO PRODUCE SHOWERS AND A
FEW STORMS MOSTLY SOUTH OF RT 460...THROUGH THE PERIOD. TEMPS WILL
BE NOTICEABLY COOLER AND ATTM SUNDAY SEEMS TO HAVE THE MOST COVERAGE
OF SHOWERS ROUGHLY FROM TNB TO HLX. H85 TEMPS FROM +12C TO +14C WITH
CLOUDS AND OFF ON AND SHOWERS SHOULD PUT MAX T IN THE MIDDLE 70S TO
LOWER 80S ACROSS THE CWA.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
AS OF 1215 PM EDT FRIDAY...
UPPER TROF ACROSS THE EAST WILL GRADUALLY WEAKEN AND START TO LIFT
OUT BY LATE IN THE WEEK AS WEAK SURFACE HIGH PRESSURE REMAINS IN
PLACE. HOWEVER MODELS SUGGEST THAT A 5H IMPULSE ROTATING AROUND THE
DEPARTING TROFFINESS THRU THE MID MISS VALLEY...COULD EVOLVE INTO A
WEAK UPPER LOW BY MID WEEK WHICH MAY SLIP EAST INTO THE CENTRAL
APPALACHIANS BY FRIDAY. THIS QUITE UNCERTAIN AND MAINLY SUPPORTED BY
THE LATEST ECMWF...BUT WOULD BE ENOUGH TO LIKELY ENHANCE CONVECTIVE
CHANCES LATER IN THE WEEK DESPITE WEAK RIDGING IN PLACE. OTRW TREND
IN THE OVERALL FORECAST REMAINS ON THE DRY SIDE WITH THE RESIDUAL
AXIS OF DEEPER MOISTURE STILL TO THE SE...AND CONTINUED DRIER NORTH
TO NE FLOW IN PLACE. THIS LOW LEVEL ONSHORE FLOW COULD BRING IN SOME
LOW CLOUDS TO ALONG THE BLUE RIDGE AT TIMES DURING THE OVERNIGHTS
BUT IFFY. OTRW INTERVALS OF CLOUDS AND SUN THRU THE PERIOD WITH MAINLY
DIURNALLY DRIVEN SLIGHT CHANCE CONVECTIVE POPS ESPCLY SW AND
MOUNTAINS WHERE AIDED BY LOCAL CONVERGENCE. COVERAGE PERHAPS A BIT
MORE LATE IN THE WEEK OVER THE SOUTH IF THE WEAK CUTOFF DEVELOPS AND
BETTER MOISTURE GETS RETURNED NORTH. TEMPS MAINLY PERSISTENCE THRU
THE PERIOD UNDER HIGH PRESSURE/LIGHT WINDS...AND ONLY SLIGHT WARMING
ALOFT...WITH HIGHS 70S TO ARND 80 MOUNTAINS AND LOW/MID 80S EAST.
&&
.AVIATION /17Z FRIDAY THROUGH TUESDAY/...
AS OF 105 PM EDT FRIDAY...
MAIN FOCUS FOR TAF VALID PERIOD IS CHANCE FOR CONVECTION THIS
AFTERNOON/EVENING. REGIONAL WSR-88D LOOP SHOWED SCATTERED SHOWERS
AND ISOLATED THUNDERSTORMS MOVING EAST ACROSS THE WESTERN MOUNTAINS.
LOOKS LIKE THE BEST INSTABILITY JUST IN FRONT OF THE CLOUD BLANKET.
COLD FRONT LOCATED TO OUR WEST ALONG THE OHIO RIVER WILL MOVE EAST
ACROSS OUR REGION WITH SCATTERED MVFR SHOWERS AND THUNDERSTORM.
LOCALL IFR CONDITIONS AND GUSTY WINDS POSSIBLE WITH A STRONGER
STORM. ACCORDING TO THE HRRR AND LOCAL WRFARW-RNK LOOKS LIKE THE
BEST CHANCE FOR A THUNDERSTORM MAY BE AT BLF OR DAN. HOWEVER
THUNDERSTORMS ARE POSSIBLE AT ALL TAF SITES THIS AFTERNOON INTO
TONIGHT WITH COLD FRONT MOVING ACROSS THE REGION.
ANOTHER CONCERN IS WHETHER OR NOT CLOUDS/PCPN WILL EXIT THE AREA...OR
BUILD BACK NORTHWARD OVERNIGHT IN WAKE OF INITIAL WAVE OF
SHRA/TSRA. KEPT MVFR CLOUDS-CIGS AND MVFR-IFR VSBYS IN -RA/-SHRA/-DZ AFT
08Z. THINKING IS THAT -SHRA WILL GENERALLY BE CONFINED TO PIEDMONT
REGION...BUT UPSLOPE FLOW AND PASSING WAVE ALONG FRONT TO THE
SOUTH COULD PROMOTE DEVELOPMENT OF LOW CLOUDS AND -DZ BLF-LWB AFT
08Z SAT. WINDS REMAIN W-NW THROUGH TAF VALID PERIOD...BUT WILL BE
VEERING OVER TO NE NEAR 12Z SAT...WHICH WILL FURTHER PROMOTE
DEVELOPMENT OF LOW CLOUDS AND FOG...ESPECIALLY ACROSS THE PIEDMONT
REGION.
EXTENDED AVIATION DISCUSSION...
THE FRONT SLOWS AND LINGERS ACROSS THE CAROLINAS THROUGH THE
WEEKEND...WHILE HIGH PRESSURE PASSES EASTWARD TO THE SOUTH OF THE
GREAT LAKES. EXPECT MOST OF THE AREA TO REMAIN DRY ON
SATURDAY...HOWEVER WIDELY SCATTERED SHOWERS AND THUNDERSTORMS WILL
DEVELOP MAINLY ACROSS THE MOUNTAINS WITH AFTERNOON HEATING FROM
SUNDAY INTO THE MIDDLE OF NEXT WEEK.
&&
.EQUIPMENT...
KFCX RADAR IS DOWN. KLYSTRON BLOWER MOTOR HAS FAILED. PARTS ON ORDER.
ESTIMATED RTS ABOUT 2015Z OR 415 PM SATURDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...KK/RAB
NEAR TERM...RAB
SHORT TERM...KM
LONG TERM...JH
AVIATION...KK/RAB
EQUIPMENT...KK
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1223 PM EDT FRI AUG 17 2012
.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION TODAY ACCOMPANIED BY SHOWERS
AND THUNDERSTORMS DURING THE AFTERNOON AND EVENING. DEEPENING LOW
PRESSURE...ANCHORED OVER SOUTHEAST CANADA...WILL EVOLVE ACROSS THE
EASTERN U.S. FOR THE WEEKEND INTO THE FIRST HALF OF NEXT WEEK. A
SERIES OF DISTURBANCES EMBEDDED WITHIN THE UPPER LOW WILL KEEP
UNSETTLED...SHOWERY...CLOUDY...COOL CONDITIONS ACROSS MUCH OF THE
AREA UNTIL TUESDAY...WHEN DRIER CONDITIONS ALONG WITH SEASONABLE
TEMPERATURES ARE EXPECTED.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 940 AM EDT FRIDAY...
LOW CLOUDS AND FOG ARE LIFTING AS HIGH CLOUDS SPREAD EAST INTO OUR
REGION. EXPECT SUFFICIENT HEATING COMBINED WITH LOW-LEVEL MOISTURE
INCREASE TO SUPPORT SCATTERED SHOWERS AND THUNDERSTORMS THIS AFTERNOON
INTO TONIGHT. SWODY1 HAS KEPT WESTERN PORTIONS OF CWA IN SLIGHT
RISK OF SEVERE FOR THIS AFTERNOON. THE MAIN THREAT IS FOR DAMAGING
WINDS. HRRR AND WRF-ARWRNK SHOWED CONVECTION STARTING AFTER 19Z
AND MOVES EAST INTO TONIGHT. MODIFIED CLOUD COVER AND POPS FOR
THIS MORNING INTO THIS AFTERNOON. ADJUSTED TEMPERATURES ACCORDING
TO LATEST OBS AND MODEL TRENDS. MADE A LITTLE COOLER IN THE WEST
WITH ADDITIONAL LOW CLOUDS THIS MORNING.
AS OF 500 AM EDT FRIDAY...
MAIN CONCERN THROUGH THE SHORT TERM WILL BE APPROACHING SHORT
WAVE...NOW LOCATED FROM THE EASTERN GREAT LAKES SWWD INTO OK/MO.
AN OVERNIGHT MCS ASSOCIATED WITH THIS TROUGH BACKBUILT
SOUTHWESTWARD INTO THE MID-SOUTH/LOWER MS VALLEY REGION...WITH
LITTLE TO NO ACTIVITY CURRENT EVIDENT FURTHER NORTH ACROSS THE OH
VALLEY. THIS SHORT WAVE WILL PROGRESS TOWARD THE MID-ATLANTIC BY
00Z AND EVOLVE INTO A DEEPENING AREA OF SEMI-PERMANENT UPPER LOW
PRESSURE ALOFT ACROSS SOUTHEAST CANADA THROUGH THE WEEKEND AND
INTO EARLY NEXT WEEK. IN SO DOING...DYNAMICS WILL WEAKEN AS THE
SYSTEM PROGRESSES TOWARD THE EAST COAST. EXTENSIVE MID-HIGH CLOUDS
HAVE SPREAD EASTWARD ACROSS THE OH VALLEY INTO PARTS OF WV EARLY
THIS MORNING...BUT THE LACK OF UPSTREAM CONVECTION SUPPORTS
CURRENT THINKING THAT ANTECEDENT CLOUD COVER ACROSS OUR CWA WILL
BE LIMITED ENOUGH TO ALLOW SUFFICIENT HEATING COMBINED WITH A SLOW
LOW-LEVEL MOISTURE INCREASE TO SUPPORT SCT SHRA/TSRA BY MID-DAY
THROUGH THE EVENING FROM W-E. SPC HAS OUTLOOKED THE ENTIRE CWA FOR
SLIGHT RISK FOR MULTI-CELL TSRA WITH SPOTTY MARGINAL HAIL AND
DAMAGING WINDS. MODEL PROGGED INSTABILITY IS WEAK AT BEST AND SHEAR
IS NIL...SO LOCAL THINKING IS THAT A 5 PERCENT RISK OF SEVERE MAY
BE SUFFICIENT TO COVER EXPECTED CONVECTIVE ACTIVITY TODAY. CERTAINLY
CANNOT RULE OUT A WARNING OR TWO DURING THE AFTERNOON/EARLY
EVENING...ESPECIALLY ACROSS THE SOUTHERN SHENANDOAH VALLEY...FAR
SOUTHWEST VA...AND NORTHERN PIEDMONT REGION. ACTIVITY SHOULD WANE
RATHER QUICKLY AFT 00Z AS THE UPPER SHORT WAVE SHEARS OUT AND THE
MAIN DYNAMICS MOVE TOWARD NEW ENGLAND. ALTHOUGH SHRA/TSRA ACTIVITY
SHOULD GENERALLY DISSIPATE ACROSS E/SE SECTIONS OF THE CWA AFT
06Z...EMBEDDED UPSTREAM SHORT WAVES...PARTICULARLY ONE POISED
ACROSS THE UPPER MIDWEST/NORTHERN PLAINS OVERNIGHT...WILL PROLONG
SW FLOW ALOFT AND DELAY ANY CLEARING DURING THE REMAINDER OF THE
NEAR TERM.
MAX TEMPS TODAY WILL BE PROBLEMATIC AND COULD EASILY VARY BY AS
MUCH AS 20F OR MORE FROM THE WV SIDE OF THE CWA TO THE SE PIEDMONT
REGION. EXTENSIVE MID-HIGH CLOUDS SHOULD SPREAD ACROSS AREAS
ALONG-W OF THE ALLEGHANYS EARLY ENOUGH IN THE DAY TO GREATLY LIMIT
DAYTIME HEATING ACROSS THOSE AREAS...WITH SHRA/TSRA DEVELOPING
WEST OF A ROA-HLX-HKY LINE BY 18Z. EAST OF THIS AREA...CLOUDS WILL
BE SLOWER TO ARRIVE WITH INITIAL SFC MOISTURE LIMITING EARLY CU
DEVELOPMENT. WITH 850MB TEMPS NEAR +18C BY AFTERNOON...ALBEIT 2C
COOLER THAN INDICATED ACROSS THAT REGION YESTERDAY...AREAS FROM
LYH-DAN EASTWARD COULD EASILY APPROACH 90 BY AFTERNOON.
THUS...HAVE MAX TEMPS RANGING FROM THE MID 70S SE WV TO AROUND DAN
AND POINTS EASTWARD. RADIATIONAL COOLING OVERNIGHT WILL BE MINIMAL
TO NONE WITH EXTENSIVE CLOUD COVER REMAINING IN PLACE. DEWPOINTS
WILL REMAIN IN THE 60S TO EVEN NEAR 70 ACROSS THE SE PIEDMONT
REGION. THUS...EXPECT MIN TEMPS TO GENERALLY BE AOA THIS MORNINGS
READINGS WITH LESS VARIATION NOTED...RANGING FROM THE LOW 60S
MOUNTAINS/SE WV TO NEAR 70 DAN AND POINTS EASTWARD.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
AS OF 430 AM THURSDAY...
ALTHOUGH THE COLD FRONT WILL REMAIN ACROSS NORTH CAROLINA FOR MOST
OF THE WEEKEND...ENOUGH MOISTURE WILL COMBINE WITH WEAK UPPER LEVEL
DISTURBANCES AND SURFACE WIND CONVERGENCE TO PRODUCE SHOWERS AND A
FEW STORMS MOSTLY SOUTH OF RT 460...THROUGH THE PERIOD. TEMPS WILL
BE NOTICEABLY COOLER AND ATTM SUNDAY SEEMS TO HAVE THE MOST COVERAGE
OF SHOWERS ROUGHLY FROM TNB TO HLX. H85 TEMPS FROM +12C TO +14C WITH
CLOUDS AND OFF ON AND SHOWERS SHOULD PUT MAX T IN THE MIDDLE 70S TO
LOWER 80S ACROSS THE CWA.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 1215 PM EDT FRIDAY...
UPPER TROF ACROSS THE EAST WILL GRADUALLY WEAKEN AND START TO LIFT
OUT BY LATE IN THE WEEK AS WEAK SURFACE HIGH PRESSURE REMAINS IN
PLACE. HOWEVER MODELS SUGGEST THAT A 5H IMPULSE ROTATING AROUND THE
DEPARTING TROFFINESS THRU THE MID MISS VALLEY...COULD EVOLVE INTO A
WEAK UPPER LOW BY MID WEEK WHICH MAY SLIP EAST INTO THE CENTRAL
APPALACHIANS BY FRIDAY. THIS QUITE UNCERTAIN AND MAINLY SUPPORTED BY
THE LATEST ECMWF...BUT WOULD BE ENOUGH TO LIKELY ENHANCE CONVECTIVE
CHANCES LATER IN THE WEEK DESPITE WEAK RIDGING IN PLACE. OTRW TREND
IN THE OVERALL FORECAST REMAINS ON THE DRY SIDE WITH THE RESIDUAL
AXIS OF DEEPER MOISTURE STILL TO THE SE...AND CONTINUED DRIER NORTH
TO NE FLOW IN PLACE. THIS LOW LEVEL ONSHORE FLOW COULD BRING IN SOME
LOW CLOUDS TO ALONG THE BLUE RIDGE AT TIMES DURING THE OVERNIGHTS
BUT IFFY. OTRW INTERVALS OF CLOUDS AND SUN THRU THE PERIOD WITH MAINLY
DIURNALLY DRIVEN SLIGHT CHANCE CONVECTIVE POPS ESPCLY SW AND
MOUNTAINS WHERE AIDED BY LOCAL CONVERGENCE. COVERAGE PERHAPS A BIT
MORE LATE IN THE WEEK OVER THE SOUTH IF THE WEAK CUTOFF DEVELOPS AND
BETTER MOISTURE GETS RETURNED NORTH. TEMPS MAINLY PERSISTENCE THRU
THE PERIOD UNDER HIGH PRESSURE/LIGHT WINDS...AND ONLY SLIGHT WARMING
ALOFT...WITH HIGHS 70S TO ARND 80 MOUNTAINS AND LOW/MID 80S EAST.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 740 AM EDT FRIDAY...
IMMEDIATE CONCERN IS LOCALIZED POCKETS OF IFR-LIFR CIGS/VSBYS IN FG
AT THE USUAL SPOTS...NAMELY LWB AND BCB. THIS SHOULD DISSIPATE
QUICKLY...BUT MAY HANG ON FOR A LITTLE WHILE AT LWB BECAUSE OF
REDUCED INSOLATION FROM INCREASING HIGH CLOUDS. WILL NEED TO WATCH
FOR DEVELOPMENT OF MVFR CIGS BLF-LWB AS WELL AS FOG LIFTS INTO
STRATUS DECK. STRATUS ALREADY EVIDENT JUST TO THE WEST OF BLF. AS
NOTED BEFORE...MAIN FOCUS FOR TAF VALID PERIOD IS CHANCE FOR
CONVECTION THIS AFTERNOON/EVENING. NEW CONCERN IS WHETHER OR NOT
CLOUDS/PCPN WILL EXIT THE AREA...OR BUILD BACK NORTHWARD OVERNIGHT
IN WAKE OF INITIAL WAVE OF SHRA/TSRA. NO CHANGES AT THIS TIME TO
EARLIER INDICATED CONVECTIVE TIMING...MAINLY 18Z LWB-BLF TO 00Z
LYH-DAN. BIGGEST CHANGE WAS TO ADD MVFR CIGS AND MVFR-IFR VSBYS IN
-RA/-SHRA/-DZ AFT 08Z. THINKING IS THAT -SHRA WILL GENERALLY BE
CONFINED TO PIEDMONT REGION...BUT UPSLOPE FLOW AND PASSING WAVE
ALONG FRONT TO THE SOUTH COULD PROMOTE DEVELOPMENT OF LOW CLOUDS AND
-DZ BLF-LWB AFT 08Z SAT. WINDS REMAIN W-NW THROUGH TAF VALID
PERIOD...BUT WILL BE VEERING OVER TO NE NEAR 12Z SAT...WHICH WILL
FURTHER PROMOTE DEVELOPMENT OF LOW CLOUDS AND FOG...ESPECIALLY
ACROSS THE PIEDMONT REGION.
AS OF 200 AM EDT FRIDAY...
MAIN CONCERN THROUGH TAF VALID PERIOD WILL BE APPROACHING/DEEPENING
UPPER TROUGH AND ASSOCIATED FRONTAL SYSTEM. VFR CONDITIONS IN PLACE
ACROSS THE CWA AT THIS HOUR WITH CONSIDERABLY LESS FOG EVIDENT THAN
AT THIS TIME YESTERDAY...LARGELY THANKS TO EXPANDING AREA OF HIGH
CLOUDS AS EXPECTED. NONETHELESS...SEVERAL HOURS OF MVFR CAN BE
EXPECTED AT BCB/LWB FOR SURE THROUGH 13Z...BUT ANY IFR CONDITIONS
SHOULD BE BRIEF/ISOLD. MODELS IN GENERAL AGREEMENT WITH RESPECT TO
TIMING OF CONVECTION. EXPECT CONVECTION TO DEVELOP LWB-BLF IN THE
18Z TIME FRAME...THEN SPREAD EAST TOWARD THE PIEDMONT BY 00Z.
GENERALLY MVFR CIGS/VSBYS EXPECTED WITH SHRA/TSRA...WITH ISOLD/BRIEF
IFR CONDITIONS TOO UNCERTAIN TO PUT IN PREVAILING OR TEMPO GROUPS AT
THIS TIME. WINDS WILL REMAIN WSW-WNW THROUGH TAF VALID PERIOD...WITH
SPEEDS REMAINING LESS THAN 10KTS.
EXTENDED AVIATION DISCUSSION...
THE FRONT SLOWS AND LINGERS ACROSS THE CAROLINAS THROUGH THE
WEEKEND...WHILE HIGH PRESSURE PASSES EASTWARD TO THE SOUTH OF THE
GREAT LAKES. EXPECT MOST OF THE AREA TO REMAIN DRY ON
SATURDAY...HOWEVER WIDELY SCATTERED SHOWERS AND THUNDERSTORMS WILL
DEVELOP MAINLY ACROSS THE MOUNTAINS WITH AFTERNOON HEATING FROM
SUNDAY INTO THE MIDDLE OF NEXT WEEK.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...KK/RAB
NEAR TERM...RAB
SHORT TERM...KM
LONG TERM...JH
AVIATION...RAB
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
331 PM CDT FRI AUG 17 2012
.SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT
331 PM CDT FRI AUG 17 2012
AT 3 PM...A 1020 MB SURFACE HIGH WAS CENTERED OVER SOUTHWEST
MINNESOTA AND NORTHWEST IOWA. THERE WAS ALSO A SURFACE TROUGH
NOTED IN THE WIND DATA FROM WISCONSIN RAPIDS TO ROCHESTER
MINNESOTA. WITH LITTLE MOISTURE ACROSS THE AREA...THIS FRONT IS
ONLY PRODUCING A WIND SHIFT WITH ITS PASSAGE. FURTHER ALOFT...A
SHORT WAVE TROUGH LOCATED OVER CENTRAL NORTH DAKOTA WAS PRODUCING
SOME SCATTERED TO BROKEN HIGH CLOUDS ACROSS THE AREA.
TONIGHT...THE MAIN QUESTION IS HOW WIDESPREAD THE VALLEY FOG MAY
BECOME. THE MODEL SOUNDINGS CONTINUE TO SHOW THAT THERE WILL BE
LIGHT WINDS UP TO 750 MB. THEY ALSO SHOW THAT THE SKIES WILL BE
MOSTLY CLEAR WHICH WILL ALLOW GOOD RADIATIVE COOLING. THE ONE
NEGATIVE AND IT IS A BIG ONE IS THAT THE SOUNDINGS CONTINUE TO
SHOW THAT THE BOUNDARY LAYER REMAINS VERY DRY. THIS IS IN DESPITE
THE UNSEASONABLY COOL TEMPERATURES /IN THE 40S/ OVER THE WARM /LOW
TO MID 70/ RIVERS WHICH IS USUALLY VERY CONDUCIVE TO THE
DEVELOPMENT OF STEAM/VALLEY FOG. THE DIURNAL MIXING THIS AFTERNOON
HAS ALLOWED DRY AIR FROM ALOFT TO MIX DOWN TO THE SURFACE. THIS
HAS CAUSED OUR DEW POINTS TO FALL ANYWHERE FROM 10 TO 15 DEGREES
TODAY. WITH DEW POINTS CURRENTLY IN THE MID 30S TO MID 40S...THERE
IS CONCERN THAT THE DEW POINTS WILL NOT RECOVER ENOUGH TONIGHT TO
ALLOW THE VALLEY FOG TO FORM. A LOCAL COMPOSITE STUDY FOR KLSE
SHOWS THAT IF THE TEMPERATURE/DEW POINT SPREAD IS MORE THAN 7
DEGREES AT 03Z...THAT THE PROBABILITIES OF DENSE FOG /QUARTER MILE
OR LESS/ DRAMATICALLY DECREASE. SINCE WE ARE STILL A BIT UNSURE
HOW MUCH RECOVERY THERE WILL BE IN THE DEW POINTS TONIGHT...KEPT
THE AREAS OF VALLEY FOG IN THE FORECAST FOR TONIGHT. THE ONLY
CHANGE AT THIS TIME WAS DELAY THE ONSET FROM 18.06Z TO 18.09Z.
ON SATURDAY...A TROUGH OF LOW PRESSURE WILL MOVE SOUTH INTO
NORTHERN MINNESOTA AND NORTHERN WISCONSIN. AHEAD OF THE FORMER
SYSTEM...THE MODELS INDICATE THAT WITH DIURNAL HEATING...THE ML
CAPES WILL CLIMB UP TO 300 J/KG NORTH OF THE INTERSTATE 94
CORRIDOR. THIS WILL BE ENOUGH INSTABILITY TO WARRANT A SMALL
CHANCE /15 TO 24 PERCENT/ OF PRECIPITATION DURING THE AFTERNOON
AND EVENING. EVEN THOUGH THE MODELS MIGHT SUGGEST A HIGHER
PRECIPITATION CHANCE...WAS CONCERNED THAT THE MODEL SOUNDINGS
SUGGESTED THE POSSIBILITY THAT THE DEW POINTS ONCE AGAIN FALL INTO
THE 40S ON SATURDAY AFTERNOON. IF THIS OCCURRED...THERE WOULD NOT
BE ENOUGH INSTABILITY TO GENERATE ANY PRECIPITATION. AS A
RESULT...KEPT THE PRECIPITATION CHANCES ON THE LOW SIDE.
ON SATURDAY NIGHT...THE MODELS CONTINUE TO SUGGEST THAT THE
TROUGH ACROSS NORTHERN MINNESOTA AND NORTHERN WISCONSIN WILL MOVE
SOUTHEAST TO THE INTERSTATE 90 CORRIDOR. AT THIS TIME...IT LOOKS
LIKE THIS SYSTEM WILL ONLY BRING SOME MID AND HIGH CLOUDS TO THE
AREA. THESE CLOUDS WILL LIMIT THE COOLING SOME...SO KEPT THE
VALLEY FOG OUT OF THE FORECAST.
ON SUNDAY...THE MODELS CONTINUE TO SUGGEST THAT THE CAPES MAY
CLIMB UP TO 500 J/KG ACROSS SOUTHERN WISCONSIN. AS A RESULT...
KEPT A CHANCE OF SHOWERS IN THE FORECAST. HOWEVER LIKE
SATURDAY...THERE IS SOME QUESTIONS ON WHETHER THE DEW POINTS ARE
TOO HIGH...SO KEPT THE MENTION OF THUNDER OUT OF THE FORECAST.
.LONG TERM...MONDAY THROUGH FRIDAY
331 PM CDT FRI AUG 17 2012
FROM MONDAY THROUGH THURSDAY...THE MODELS STILL SHOW THAT THE
UPPER LEVEL RIDGE OVER THE ROCKIES WILL MOVE EASTWARD AND FLATTEN
AS A SERIES OF SHORT WAVE TROUGHS OVERRUN IT. LIKE THE ECMWF OVER
THE PAST 2 DAYS...THE GFS NOW SHOWS THAT THESE SYSTEMS WILL BE
MUCH FURTHER NORTH. AS A RESULT...WENT WITH A DRY FORECAST FOR
THIS TIME PERIOD. IN ADDITION...WITH MORE SUNSHINE EXPECTED
BOOSTED TEMPERATURES A BIT.
ON THURSDAY NIGHT AND FRIDAY...THE GFS SHOWS THAT A COLD FRONT
WILL MOVE EAST THROUGH THE AREA. MEANWHILE ECMWF KEEPS THE RIDGE
INTACT DURING THIS TIME PERIOD. SINCE THE ECMWF TYPICALLY DOES THE
BEST...JUST WENT WITH A DRY FORECAST.
&&
.AVIATION...THROUGH 18Z SATURDAY
1213 PM CDT FRI AUG 17 2012
THE MAIN CONCERN THROUGH SATURDAY MORNING IS WHETHER VALLEY FOG
WILL FORM AND RESTRICT THE VISIBILITY AT KLSE. THE 17.12Z NAM AND
17.15Z RAP CONTINUE TO SHOW SOME SIGNALS THAT THE VALLEY FOG IS
NOT A CERTAINTY TO FORM. WHILE THE SURFACE HIGH WILL BE OVER THE
AREA TO PROVIDE CLEAR SKIES AND LIGHT WINDS THROUGH A DEEP
LAYER...THE CONCERN IS WHETHER SATURATION WILL OCCUR. DEW POINTS
THIS AFTERNOON ARE EXPECTED TO MIX OUT INTO THE LOWER TO MIDDLE
40S AND THEN RECOVER AROUND 5 DEGREES DURING THE EVENING. NEITHER
THE NAM OR THE RAP SHOW ENOUGH RECOVERY IN THE DEW POINT OR
COOLING OF THE SURFACE TEMPERATURES TO ALLOW SATURATION TO OCCUR.
THE SHORT TERM LAV GUIDANCE WHICH IS USUALLY AGGRESSIVE WITH THE
FORMATION OF FOG AND VISIBILITY RESTRICTION ALSO DOES NOT SHOW ANY
FOG FORMING DESPITE ONLY HAVING A 1 TO 2 DEGREE TEMP/DEW POINT
SPREAD LATE TONIGHT. THUS WITH MIXED SIGNALS...HAVE NOT MADE ANY
CHANGES TO THE FORECAST FOR KLSE. STILL FEEL THERE WILL BE SOME
VALLEY FOG THAT FORMS...BUT WITH CONCERNS ON HOW MUCH...LEFT THE
VISIBILITY MVFR WITH THE INCLUSION OF BCFG. NO CONCERNS AT KRST
THROUGH 18Z SATURDAY WITH VFR CONDITIONS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
331 PM CDT FRI AUG 17 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1214 PM CDT FRI AUG 17 2012
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
230 AM CDT FRI AUG 17 2012
FORECAST CONCERNS FOCUS ON THE PCPN POTENTIAL WITH A WEATHER SYSTEM
TRACKING ACROSS THE REGION SAT-SUN.
A SHORTWAVE TROUGH WILL DROP SOUTHWARD OUT OF CANADA...SLIDING
ACROSS THE NORTHERN PLAINS AND ACROSS IA/ILL. ITS CURRENT TRACK
WOULD KEEP ANY ASSOCIATED PCPN CHANCES WEST/SOUTH OF THE FORECAST
AREA. HOWEVER...IT WILL ALSO HELP CARVE OUT THE BROAD UPPER LEVEL
TROUGH A BIT MORE...WHICH WILL ALLOW ANOTHER PIECE OF ENERGY TO SLIP
ACROSS NORTHERN PARTS OF THE REGION SAT AFTERNOON/EVENING. THIS
UPPER LEVEL FEATURE ALSO LOOKS TO HAVE A REFLECTION AT THE SFC...AND
THERE IS SOME WEAK LOW LEVEL FRONTOGENETIC FORCING WITH IT. THE
17.00Z NAM PAINTS AROUND 500 J/KG OF MUCAPE AROUND THIS BOUNDARY
WHILE A NORTH-SOUTH RUNNING X-SECTION POINTS TO A DECENT AMOUNT OF
SATURATION IN THE 700-500 MB FOR THE FORCING/INSTABILITY TO WORK ON.
THE NAM/GFS/GEM/ECMWF ALL DEPICT SOME LIGHT PCPN WITH THIS
SYSTEM...MOSTLY FROM CENTRAL MN ACROSS NORTHERN WI. CLOUD BASES
WOULD PROBABLY BE RATHER HIGH...BUT THERE HAS BEEN A LOT OF 8-10 KFT
OVER THE PAST FEW WEEKS THAT HAVE BEEN PRODUCING PCPN...DESPITE SOME
INDICATIONS OF A DRY NEAR SFC LAYER. BELIEVE THERE IS ENOUGH FORCING
TO WORK ON THE SATURATION FOR AT LEAST SMALL PCPN CHANCES. PROBABLY
MORE SHOWERS...BUT CAN/T RULE OUT ISOLATED THUNDER.
THE SFC BOUNDARY WILL SAG SOUTH SAT NIGHT...SLIDING ACROSS SOUTHERN
WI ON SUNDAY. COULD BE ENOUGH FORCING AROUND THE FRONT TO SPARK MORE
SHOWER CHANCES. SOUTHERN WI/NORTHERN ILL WOULD LIKELY HAVE THE
BETTER OPPORTUNITY FOR SOME PCPN...ALTHOUGH CHANCES APPEAR
SMALL...AS WOULD AMOUNTS.
.LONG TERM...MONDAY THROUGH THURSDAY
230 AM CDT FRI AUG 17 2012
OVERALL TREND FAVORS SHIFTING THE UPPER LEVEL TROUGH EASTWARD FOR
THE NEW WORK WEEK...WHILE THE RIDGE TO THE WEST WORKS TOWARD THE
REGION...BREAKING DOWN SOMEWHAT. 17.00Z GFS IN BETTER AGREEMENT WITH
THE EC AND GEM...HOLDING OFF ON WHAT WOULD HAVE BEEN A MID WEEK
SHORTWAVE. INSTEAD...ITS MORE SUGGESTIVE OF A BIT OF UPPER LEVEL
ENERGY MOVING ACROSS THE NORTHERN GREAT LAKES...DRAGGING A SFC
BOUNDARY ACROSS THE REGION. SMALL RAIN CHANCES COULD RESULT ON WED.
GFS TRENDS AWAY FROM THE EC THU-FRI...PUSHING A SHORTWAVE INTO THE
UPPER LEVEL RIDGE ABOUT A DAY FASTER THAN THE EC. THE THE GFS HAS
NOT SHOWN MUCH CONSISTENCY WITHIN ITSELF WHILE THE EC HAS BEEN
BETTER RUN TO RUN. OVERALL...CONFIDENCE NOT THAT HIGH BY MID/LATE
WEEK...AND WILL LEAN ON THE CONSENSUS/EC SOLUTION FOR NOW. WITH SOME
CHANGE TO A MORE ZONAL-RIDING A LOFT PATTERN...EXPECT TEMPS TO
GRADUALLY WARM BACK TO SEASONABLE NORMS.
&&
.AVIATION...THROUGH 18Z SATURDAY
1213 PM CDT FRI AUG 17 2012
THE MAIN CONCERN THROUGH SATURDAY MORNING IS WHETHER VALLEY FOG
WILL FORM AND RESTRICT THE VISIBILITY AT KLSE. THE 17.12Z NAM AND
17.15Z RAP CONTINUE TO SHOW SOME SIGNALS THAT THE VALLEY FOG IS
NOT A CERTAINTY TO FORM. WHILE THE SURFACE HIGH WILL BE OVER THE
AREA TO PROVIDE CLEAR SKIES AND LIGHT WINDS THROUGH A DEEP
LAYER...THE CONCERN IS WHETHER SATURATION WILL OCCUR. DEW POINTS
THIS AFTERNOON ARE EXPECTED TO MIX OUT INTO THE LOWER TO MIDDLE
40S AND THEN RECOVER AROUND 5 DEGREES DURING THE EVENING. NEITHER
THE NAM OR THE RAP SHOW ENOUGH RECOVERY IN THE DEW POINT OR
COOLING OF THE SURFACE TEMPERATURES TO ALLOW SATURATION TO OCCUR.
THE SHORT TERM LAV GUIDANCE WHICH IS USUALLY AGGRESSIVE WITH THE
FORMATION OF FOG AND VISIBILITY RESTRICTION ALSO DOES NOT SHOW ANY
FOG FORMING DESPITE ONLY HAVING A 1 TO 2 DEGREE TEMP/DEW POINT
SPREAD LATE TONIGHT. THUS WITH MIXED SIGNALS...HAVE NOT MADE ANY
CHANGES TO THE FORECAST FOR KLSE. STILL FEEL THERE WILL BE SOME
VALLEY FOG THAT FORMS...BUT WITH CONCERNS ON HOW MUCH...LEFT THE
VISIBILITY MVFR WITH THE INCLUSION OF BCFG. NO CONCERNS AT KRST
THROUGH 18Z SATURDAY WITH VFR CONDITIONS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
230 AM CDT FRI AUG 17 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...04
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
249 PM MDT FRI AUG 17 2012
.SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT...
WATER VAPOR IMAGERY SHOWS FAST NORTHWEST FLOW ALOFT OVER THE WY/MT
WITH A STRONG SHORTWAVE DIVING SOUTHWARD OVER SASKATCHEWAN.
CUMULUS HAVE DEVELOPED OVER THE LARAMIE RANGE BUT FAILED TO MOVE
EASTWARD OVER THE PLAINS. THE MODELS ARE IN AGREEMENT IN SHOWING
THE SHORTWAVE DIVING SSE OVER THE NORTHERN PLAINS THROUGH TONIGHT.
ALTHOUGH THERE IS LIMITED LOW AND MIDLEVEL MOISTURE TO WORK
WITH...THE QG LIFT AHEAD OF THE SHORTWAVE COULD ENHANCE
CONVECTIVE CHANCES LATE THIS AFTERNOON AND EVENING. CURRENT LAPS
ANALYSIS SHOWS WEAK SFC INSTABILITY OVER THE PLAINS (WITH A FEW
HUNDRED J/KG OF CAPE). BOTH THE GFS AND HRRR MODELS GENERATE
ISOLATED STORMS OVER THE SOUTHEASTERN PART OF THE CWA BETWEEN 00Z
AND 06Z. KEPT SLIGHT CHANCE POPS FOR MAINLY AREAS ALONG INTERSTATE
80 TO THE EAST OF THE LARAMIE RANGE THROUGH EARLY TONIGHT. A
1018MB SFC HIGH BEHIND THE SHORTWAVE WILL DRIVE A COLD FRONT
THROUGH THE AREA LATE TONIGHT. BREEZY CONDITIONS WILL DEVELOP SAT
MORNING AFTER THE FROPA...HOWEVER PRESSURE RISES/SOUNDINGS DO NOT
SUGGEST THAT THE WINDS WILL BE PARTICULARLY STRONG.
RATHER QUIET THROUGH THE REMAINDER OF THE SHORT TERM WITH VERY DRY
NORTHWESTERLY FLOW ALOFT. HIGHS ON SAT WILL BE AROUND 5 DEGREES
COOLER IN THE POST FRONTAL AIRMASS. THE BREEZY NORTHERLY WINDS
WILL SUBSIDE ON SAT NIGHT AS THE SFC HIGH PRESSURE CENTER SETTLES
OVER THE CWA. WENT A FEW DEGREES COOLER THAN MOS FOR LOWS ON SAT
NIGHT...WITH VALUES MAINLY IN THE MID-TO-UPPER 40S OVER THE
PLAINS...WITH GOOD RADIATION AL COOLING POTENTIAL. 700MB TEMPS RISE
ON SUN TO 9C (FROM 7C ON SAT) FOR A FEW DEGREES OF WARMING...BUT
LITTLE OTHER CHANGE IN THE SENSIBLE WEATHER. A SHORTWAVE WILL
ROUND THE TOP OF THE INTERMOUNTAIN WEST RIDGE ON SUN
NIGHT...APPROACHING THE CWA BY MON.
.LONG TERM...MONDAY THROUGH FRIDAY
LONG TERM GENERALLY DOMINATED BY A RIDGE OF HIGH PRESSURE WITH
THE RIDGE AXIS WEST OF THE CWA EARLY. WE GET A SHORTWAVE THAT
MOVES DOWN THROUGH THE NORTHWEST FLOW MONDAY...EXITING EAST BY
MONDAY AFTERNOON. GENERALLY DRY CONDITIONS EXPECTED WITH THE
EXCEPTION POSSIBLY BEING THE HIGHER TERRAIN OF THE SNOWY...SIERRA
MADRE AND NORTHERN LARAMIE RANGES MONDAY AFTERNOON.
RIDGE AXIS THEN BUILDS OVER THE CWA TUESDAY WITH THE AXIS SHIFTING
EAST BY TUESDAY AFTERNOON. COULD SEE AN INCREASE IN FIRE WEATHER
CONCERNS AS WINDS SHIFT SOUTHWEST AND BEGIN TO INCREASE. GFS
SHOWING 20 TO 25KTS OF WIND AT 700MB AS ANOTHER SHORTWAVE TRACKS
INTO IDAHO AND NORTHERN UTAH. THIS SHORTWAVE TRACKS NORTHEAST
ACROSS WESTERN WYOMING TUESDAY NIGHT INTO WEDNESDAY...DRAGGING A
COLD FRONT THROUGH AT LEAST OUR WESTERN ZONES WEDNESDAY EVENING.
MAINTAINED...AND SLIGHTLY INCREASED POP COVERAGE FOR THIS AREA
WEDNESDAY NIGHT. WEDNESDAY MOST LIKELY OUR WARMEST DAY NEXT WEEK
WITH HIGHS CLIMBING BACK INTO THE 90S WITH THESE GUSTY WINDS. DRIER
CONDITIONS RETURNING FOR THE END OF THE WEEK CWA WIDE.
&&
.AVIATION...18Z TAFS
VFR CONDITIONS EXPECTED NEXT 24 HOURS AT MOST AIRPORTS ACROSS
SOUTHEAST WYOMING AND NEBRASKA PANHANDLE. CHEYENNE COULD SEE SOME
ISOLATED THUNDERSTORMS THIS AFTERNOON...BUT CONFIDENCE NOT HIGH
ENOUGH TO NAIL DOWN TIMING. WENT WITH VCTS WORDING IN TAF UNTIL THE
01-02Z TIME FRAME. ELSEWHERE...MAINLY CLEAR SKIES AND NO IMPACTS TO
AVIATION INTERESTS.
&&
.FIRE WEATHER...
FIRE WEATHER CONCERNS WILL BE MINIMAL THROUGH THE WEEKEND. A COLD
FRONT WILL MOVE ACROSS THE AREA TONIGHT BRINGING BREEZY NORTHERLY
WINDS AND COOLER THAN AVERAGE TEMPERATURES ON SATURDAY. MINIMUM
AFTERNOON RELATIVE HUMIDITY VALUES WILL BE IN THE 15 TO 20 PERCENT
RANGE. THE AIRMASS WILL BEGIN TO WARM ON SUNDAY WITH AFTERNOON
HUMIDITIES DROPPING BELOW 15 PERCENT TO THE WEST OF THE LARAMIE
RANGE. HOWEVER...WINDS WILL BE LIGHT WITH THE SURFACE HIGH
PRESSURE CENTER NEAR SOUTHEAST WYOMING. PRECIPITATION CHANCES WILL
BE LOW THROUGH EARLY NEXT WEEK WITH A DRY AIRMASS IN
PLACE...HOWEVER SOME ISOLATED SHOWER AND THUNDERSTORMS WILL BE
POSSIBLE STARTING MONDAY OVER THE MOUNTAINS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM/FIRE WEATHER...FINCH
LONG TERM/AVIATION...CLAYCOMB