Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/07/12
AREA FORECAST DISCUSSION
NWS NEW YORK NY
357 PM EDT SUN AUG 5 2012
.SYNOPSIS...
A COLD FRONT WILL PASS THROUGH THE REGION LATE TONIGHT. HIGH
PRESSURE BUILDS IN THROUGH THE MIDDLE OF THE WEEK. A SLOW MOVING
FRONTAL SYSTEM MAY THEN IMPACT THE AREA FOR THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 10 PM THIS EVENING/...
MAIN LINE OF TSTMS ACROSS CNTRL PA TIMED TO REACH THE WRN FRINGE
OF THE CWA AROUND 1Z..TRACKING EWD AT AROUND 35KT. AHEAD OF THIS
ACTIVITY...ISOLD-SCT DEVELOPMENT CAN BE EXPECTED.
WINDS ALOFT ABOUT 30KT PER THE OKX VWP. THESE WINDS ARE MIXING
DOWN IN ANY TSTMS...AND WILL CONTINUE TO BE THE CASE THRU THIS
EVE. SOME STRENGTHENING TO UP TO 40KT ALOFT POSSIBLE AS THE GRAD
INCREASES.
IT APPEARS TO BE MORE STABLE OVER THE S COASTS PER STLT...SO HAVE
KEPT THE FCST MAINLY DRY ACROSS PORTIONS OF LI UNTIL TNGT.
ELSEWHERE...POPS ARE BASED ON THE HRRR FOR ONGOING CONVECTION WITH
A BACKGROUND OF ISOLD CHANCES.
MAIN THREAT WITH THE LINE APPEARS TO BE WIND AS IT APPROACHES.
STILL TIME TO EVALUATE THE POTENTIAL...BUT THE DEVELOPMENT OF A
SIGNIFICANT COLD POOL COULD POSE THE MOST SVR WIND THREAT.
&&
.SHORT TERM /10 PM THIS EVENING THROUGH MONDAY NIGHT/...
TSTMS WILL CONTINUE TO ROLL EWD AHEAD OF THE FRONT OVERNIGHT. THERE
WILL REMAIN THE THREAT FOR AN EMBEDDED SVR STORM...ESPECIALLY
ACROSS LI AS A BOUNDARY FORMS DUE TO THE ONSHORE FLOW AND LAND/SEA
INTERACTION. MAIN THREAT HOWEVER WILL REMAIN THE LOC HVY RAIN.
LOW TEMPS KEPT NEAR THE NAM 2M NUMBERS DUE TO THE LLVL MOISTURE IN
PLACE.
12Z MODEL SUITE HAS COME IN QUICKER WITH THE CLEARING FOR MON.
HAVE ACCEPTED THIS TREND BASED ON WHERE THE SYSTEM CURRENTLY IS
AND THE 00Z ECMWF. FCST INDICATES A SUNNY AFTN. HUMIDITY WILL BE
MUCH LOWER AS THE MOIST AIRMASS IS SHUNTED OFFSHORE. TEMPS A BLEND
OF GUIDANCE AND SEASONAL.
THERE IS A MDT RISK OF RIPS ON THE OCEANFRONT.
MAINLY SKC AND COOL MON NGT WITH TEMPS DROPPING INTO THE 50S
ACROSS THE COOL SPOTS.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
FAIR WEATHER THRU MIDWEEK WITH HIPRES TRAVERSING THE ERN SEABOARD.
RETURN FLOW THEN BRING ENOUGH HUMIDITY FOR PERHAPS A FEW ISOLD
DIURNAL TSTMS...MAINLY ACROSS THE INTERIOR...WED.
AS THE UPR RIDGE OVER THE PLAINS BUILDS WWD OVER THE 4
CORNERS...THIS WILL OPEN THE DOOR TO UPR LOWS DROPPING W OF THE
CWA FOR THE END OF THE WEEK. THE RESULT WOULD BE INCREASING
HUMIDITY AND CHANCES FOR PCPN WITH SW FLOW ALOFT. WRT
SPECIFICS...THE 12Z GFS IS SIGNIFICANTLY DIFFERENT THAN THE 12Z
ECMWF...WITH THE ECMWF MUCH SLOWER WITH THE ONSET OF ORGANIZED
ACTIVITY OVER THE CWA. BECAUSE THE GFS TENDS TO OVER INITIATE
CONVECTION AND THE ECMWF HAS A GOOD TRACK RECORD WITH THE DYNAMICS
AT THE MEDIUM RANGE...WILL LEAN TOWARDS LWR POPS IN THE THU TIME
PERIOD AND FOCUS THE POTENTIAL ON FRI INTO THE WEEKEND FOR NOW.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
A COLD FRONT WILL SLOWLY APPROACH FROM THE WEST TONIGHT AND WILL
PASS TO THE EAST MONDAY MORNING.
MAINLY VFR CONDITIONS WITH CIGS 3 TO 5 KFT FOR THE REMAINDER OF
THE AFTERNOON...EXCEPT EASTERN TERMINALS WITH CIGS 2 TO 3 KFT.
AN ISOLATED SHOWER OR THUNDERSTORM IS NOT OUT OF THE QUESTION THIS
AFTERNOON...BUT WILL BE ISOLATED TO SCATTERED.
LOOKS LIKE BEST CHANCE FOR SHOWERS AND THUNDERSTORMS WILL BE LATE
AFTERNOON THROUGH THE EVENING HOURS. MVFR OR IFR CONDITIONS ARE
ALWAYS POSSIBLE IN ANY HEAVIER STORMS.
AFTER MIDNIGHT...THE FRONT APPROACHES NYC METRO WITH PERHAPS SOME
LINGERING SHOWERS. THEN CONDITIONS WILL IMPROVE AFTER 08-11Z AS
THE FRONT MOVES THROUGH. VFR BY MONDAY MORNING.
STRONG SOUTHERLY WINDS OF 15 TO 20 KTS THROUGH THE AFTERNOON WILL
LIGHTEN TO 10 TO 15 KTS BY EVENING. WINDS SLOWLY TURN TOWARD THE
SOUTHWEST. THEN WINDS ABRUPTLY SHIFT TO THE NORTH/NORTHWEST BEHIND
THE FRONT 08-11Z...FROM NW TO SOUTHEAST.
WINDS BACK SLIGHTLY TO THE NORTHWEST MONDAY MORNING AROUND 10 TO
15 KT.
OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY...
.MONDAY AFTERNOON-WEDNESDAY...VFR.
.THURSDAY-FRIDAY...MVFR OR LOWER POSSIBLE IN SCATTERED SHOWERS/TSTMS.
&&
.MARINE...
WINDS WILL GRADUALLY INCREASE THRU THIS EVE AS THE PRES GRAD
TIGHTENS. WITH NEARSHORE MESONET DATA ALREADY COMING IN WITH THE
LOW 20S...WILL ISSUE A SCA FOR TNGT FOR ALL BUT THE HARBOR. TSTMS
WILL PRODUCE GUSTS IN EXCESS OF 30KT TNGT.
WINDS DECREASE ACROSS ALL THE WATERS MON AFT THE WIND SHIFT BEHIND
THE FRONT. THE SCA WILL NEED TO REMAIN UP FOR THE OCEAN WITH
LINGERING SEAS.
WINDS AND SEAS WILL THEN REMAIN BLW SCA LVL THRU MID WEEK WITH
HIGH PRES OVER THE WATERS. SCA CONDITIONS MAY DEVELOP NEAR THE END
OF THE WEEK.
&&
.HYDROLOGY...
THE FLASH FLOOD WATCH WILL REMAIN IN EFFECT TNGT. NO EXTENSION WAS
MADE INTO THE ERN ZONES WITH FFG OVER 2 INCHES. THE THREAT IS NOT
NON-ZERO HOWEVER...AND WILL CONTINUE TO BE MENTIONED IN THE HWO.
ELSEWHERE...FFG IS LOWER AND THE THREAT FOR FLOODING
REMAINS...MAINLY AS ORGANIZED CONVECTION TRACKS ACROSS THE CWA
TNGT.
PW/S AROUND 2.5 INCHES WILL POTENTIALLY YIELD RATES OF AROUND 2
INCHES/HR IN THE HEAVIEST TSTMS.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...FLASH FLOOD WATCH THROUGH MONDAY MORNING FOR CTZ005-006-009.
NY...FLASH FLOOD WATCH THROUGH MONDAY MORNING FOR NYZ067>075-
176>179.
NJ...FLASH FLOOD WATCH THROUGH MONDAY MORNING FOR NJZ002-004-006-
103>108.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR ANZ330-335-340-
345.
SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR ANZ355.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT MONDAY FOR ANZ350-353.
&&
$$
SYNOPSIS...JMC
NEAR TERM...JMC
SHORT TERM...JMC
LONG TERM...JMC
AVIATION...PW
MARINE...JMC
HYDROLOGY...JMC
AREA FORECAST DISCUSSION
NWS ALBANY NY
637 AM EDT SUN AUG 5 2012
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY AND CROSS THE
REGION TONIGHT. SHOWERS AND THUNDERSTORMS WILL PRECEDE AND ACCOMPANY
THIS BOUNDARY WITH SOME OF THE STORMS PRODUCING VERY HEAVY RAINFALL.
A MORE SEASONABLE AND DRIER AIRMASS WILL BE USHERED INTO OUR REGION
IN THE WAKE OF THE COLD FRONT FOR MONDAY AND TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM EDT...PARTLY TO MOSTLY CLOUDY SKIES PREVAILED ACROSS
THE FA WITH WARM AND MUGGY CONDITIONS. A FEW LIGHT SHOWERS HAVE
DEVELOPED AND MOVED INTO THE WESTERN ADIRONDACKS AND WESTERN
MOHAWK VALLEY AND HAVE INCREASED POPS SLIGHTLY IN THOSE AREAS
DURING THE NEXT FEW HOURS...OTHERWISE NO OTHER CHANGES TO PREVIOUS
FORECAST. TEMPERATURES WERE GENERALLY IN THE UPPER 60S TO MID 70S
ACRS THE FA.
A VIGOROUS SHORT WAVE ACCOMPANIED BY A STRONG COLD FRONT WILL
IMPACT OUR REGION DURING THIS PERIOD WITH THE POSSIBILITY OF A
PRE-FRONTAL TROUGH CROSSING THE ALY FA LATE AFTERNOON INTO EARLY
EVENING WHICH MAY ENHANCE THE CONVECTION. THERE ARE MANY
INGREDIENTS IN PLACE FOR STRONG TO SEVERE THUNDERSTORMS AS WELL AS
HEAVY RAIN WHICH COULD PRODUCE FLASH FLOODING ESPECIALLY WHERE
CELLS TRAIN AND OR BACK BUILD. A FLASH FLOOD WATCH HAS BEEN ISSUED
FOR ALL OF EASTERN NEW YORK AND ADJACENT WESTERN NEW ENGLAND FROM
2 PM THIS AFTERNOON THROUGH EARLY MONDAY MORNING. THE TRAINING OF
CELLS IS A DISTINCT POSSIBILITY AS THE COLD FRONT IS EXPECTED TO
DROP FROM NORTHWEST TO SOUTHEAST AS THUNDERSTORMS MOVE FROM
SOUTHWEST TO NORTHEAST ALONG AND AHEAD OF IT. PWATS RISE TO 2 TO
NEARLY 2.5 INCHES THIS EVENING ALONG WITH A STRONG THETA E RIDGE
H10-H8...AND K INDEX VALUES BTWN 35 AND 40.
MLMUCAPES RISE UP TO 3000 J/KG THIS AFTERNOON WITH STRONG WIND
FIELDS AS FA ENDS UP IN RIGHT ENTRANCE REGION OF A CYCLONICALLY
CURVED 100+ KT JET ACRS ERN CANADA WHILE H8 WINDS INCREASE TO 35
TO 45 KTS AND H7 STEERING WINDS 35 TO 50 KTS FROM THE SOUTHWEST.
FURTHER 0-3 KM HELICITY VALUES INCREASE TO 150 TO 250 M2/S2
LATER THIS AFTERNOON INTO THIS EVENING. THUS THE POTENTIAL FOR
STRONG TO PERHAPS SEVERE WIND GUSTS EXIST WITH ANY STORMS AND SPC
HAS THE ALY FA OUTLOOKED AS SLIGHT RISK IN THE DAY 1 OUTLOOK. THE THREAT
OF LARGE HAIL IS CONSIDERABLY LESS AS WBZ HEIGHTS REMAIN ABOVE 12
KFT FOR MUCH OF THE PERIOD FROM THIS AFTERNOON THROUGH THIS EVENING.
HAVE CHANCE POPS INCREASING TO LIKELY POPS FROM NORTHWEST TO
SOUTHEAST DURING THE AFTERNOON INTO EARLY EVENING WITH LIKELY POPS
ACROSS ENTIRE FA FOR MUCH OF THE EVENING WITH DECREASING POPS
AFTER MIDNIGHT FROM NORTHWEST TO SOUTHEAST. EXPECT HIGHS TODAY GENERALLY
IN THE LOW TO MID 80S WITH LOWS TONIGHT GENERALLY IN THE 60S TO
LOWER 70S.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
ANY LINGERING SHOWERS OR THUNDERSTORMS ACROSS THE SOUTHEAST
PORTION OF THE FA ARE EXPECTED TO END EARLY MONDAY MORNING...OTHERWISE
DRIER...MORE SEASONABLE AND MUCH LESS HUMID CONDITIONS ARE
EXPECTED DURING THE SHORT TERM PERIOD WITH A GOOD DEAL OF SUNSHINE
ON BOTH MONDAY AND TUESDAY AND MAINLY CLEAR SKIES MONDAY NIGHT AND
TUESDAY NIGHT AS HIGH PRESSURE BUILDS ACROSS THE REGION. EXPECT
HIGHS ON MONDAY IN THE MID 70S TO MID 80S...LOWS MONDAY NIGHT IN
THE MID 50S TO LOWER 60S...HIGHS ON TUESDAY IN THE UPPER 70S TO
MID 80S AND LOWS TUESDAY NIGHT IN THE MID 50S TO MID 60S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
HAVE POPULATED THIS PORTION OF THE GRIDDED DATABASE WITH A 50/50
BLEND OF 18Z/04 HPC GUIDANCE AND 00Z/05 GMOS.
WED-THU NT...A WEAKENING SHORTWAVE WILL APPROACH FROM THE WEST LATE
WED...ALONG WITH AN ATTENDANT SURFACE BOUNDARY. FORCING ASSOCIATED
WITH THESE FEATURES MAY TRIGGER ISOLATED SHOWERS WED
AFTERNOON/EVENING ACROSS N/W AREAS...WHERE SLIGHT CHC POPS HAVE BEEN
INDICATED. THIS BOUNDARY IS THEN EXPECTED TO STALL ACROSS THE REGION
THU/THU NT. MARGINAL INSTABILITY...IN COMBINATION WITH WEAK FORCING
FROM FRONTAL BOUNDARY MAY PRODUCE ISOLATED TO SCATTERED
SHOWERS/THUNDERSTORMS ON THU...WHEN LOW CHC POPS ARE INDICATED.
EXPECT TEMPS TO AVERAGE ABOVE SEASONAL LEVELS...ALONG WITH
INCREASING HUMIDITY LEVELS DURING THIS TIME PERIOD...WITH DAYTIME
MAXES REACHING THE MID TO UPPER 80S IN VALLEYS...AND UPPER 70S TO
LOWER 80S ACROSS HIGHER ELEVATIONS. OVERNIGHT MINS SHOULD FALL INTO
THE LOWER/MID 60S IN VALLEYS...AND 55-60 ACROSS HIGHER ELEVATIONS.
FRI-SAT...CONFIDENCE INCREASING THAT A RATHER UNSETTLED PERIOD
SHOULD OCCUR...AS AN AMPLIFYING SHORTWAVE SLOWLY APPROACHES FROM THE
GREAT LAKES REGION...AND POTENTIALLY CLOSES OFF UPON APPROACHING
FROM THE WEST/SOUTHWEST. AT THE SURFACE...A WAVE...OR SERIES OF
WAVES ARE EXPECTED TO DEVELOP ALONG THE AFOREMENTIONED STALLED
FRONTAL BOUNDARY ACROSS THE REGION. THERE REMAINS SOME UNCERTAINTY
IN THE EXACT PLACEMENT AND DETAILS OF THE DEVELOPMENT OF ANY SFC
WAVE...AND MOVEMENT OF FRONTAL SYSTEMS AT THIS TIME RANGE...BUT AT
THE VERY LEAST...IT APPEARS THAT SEVERAL ROUNDS OF
SHOWERS/THUNDERSTORMS WILL BE POSSIBLE DURING THIS TIME PERIOD.
AND...DEPENDING ON HOW FAR SOUTH ANY SFC WAVE TRACKS...A PORTION OF
THE REGION COULD EVEN RECEIVE A STEADY...BENEFICIAL RAINFALL. HAVE
INCLUDED HIGH CHC POPS AT THIS TIME. GIVEN THE UNCERTAINTY IN
FRONTAL BOUNDARIES WITH THIS SYSTEM...TEMPERATURES REMAIN
TRICKY...AS A MORE SOUTHERN TRACK WITH THE LOW WOULD FAVOR NEAR
OR EVEN BELOW NORMAL DAYTIME MAXES. FOR NOW...HAVE SIDED WITH THE
AFOREMENTIONED 50/50 BLEND OF HPC GUIDANCE AND GMOS...WITH DAYTIME
MAXES IN THE LOWER 80S IN VALLEYS...AND 70S ELSEWHERE...AND
OVERNIGHT MINS MAINLY IN THE 60S AS CLOUDS AND HIGHER HUMIDITY
LEVELS KEEP NIGHTTIME TEMPS RELATIVELY WARM.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
A COLD FRONT APPROACHING FROM THE WEST WILL TRIGGER NUMEROUS
SHOWERS AND THUNDERSTORMS THIS AFTERNOON INTO THE FIRST HALF OF
TONIGHT.
VFR CONDITIONS WILL GRADUALLY BECOME MVFR...MAINLY FOR CIGS...AS
LOW STRATUS ADVECTS AND/OR DEVELOPS NORTHWARD THROUGH SUNRISE.
TRICKY CALL ON WHETHER IT REMAINS LOW MVFR...OR IFR. AT THIS
TIME...FOLLOWED CLOSE TO THE HRRR OUTPUT...WHICH IMPLIES MAINLY
MVFR CIGS INITIALLY...WITH A CHANCE FOR IFR AFTER 09Z/SUN AT ALL
TAF SITES. HOWEVER...LOCAL DOWNSLOPING WITH A S/SE FLOW MAY
PREVENT CIGS FROM CRASHING TO IFR AT KPSF AND KPOU. HAVE INDICATED
ONLY BRIEF PERIODS OF IFR TOWARD 12Z/SUN AT THESE LOCATIONS.
THIS STRATUS MAY BEGIN TO BREAK UP SUNDAY MORNING AS THE FRONTAL
BOUNDARY BEGINS TO APPROACH...AND THE FLOW BECOMES MORE SW.
CONDITIONS SHOULD GO BACK TO VFR AT ALL SITES BY THE LATE MORNING
HOURS. SOME SHOWERS AND TSTMS ARE POSSIBLE BY LATE IN THE DAY INTO
SUNDAY NIGHT AS THE FRONT CROSSES THE REGION. HAVE INDICATED A
VCTS FOR ALL TAF SITES AFTER 18Z-20Z/SUN...AS THUNDERSTORMS SHOULD
BECOME RATHER NUMEROUS LATER THIS AFTERNOON...WELL INTO THIS
EVENING. IT IS LIKELY THAT SEVERAL DISCRETE ROUNDS OF
THUNDERSTORMS OCCUR DURING THIS TIME PERIOD...WITH SOME BREAKS IN
BETWEEN.
THE THREAT FOR THUNDERSTORMS WILL GRADUALLY DECREASE TOWARD AND
ESP AFTER 06Z/MON...FIRST AT KGFL AND KALB...AND LAST AT KPSF AND
KPOU. AREAS OF MVFR/IFR FOG MAY OCCUR TOWARD AND AFTER 06Z/MON AT ALL
TAF SITES.
SOUTH/SOUTHEAST WINDS WILL PERSIST THROUGH DAYBREAK AT KALB AND
8-12 KT...WITH SOME GUSTS POSSIBLY REACHING 15-20 KT.
ELSEWHERE...WINDS SHOULD BECOME LIGHT/VARIABLE THROUGH DAYBREAK.
WINDS WILL THEN INCREASE FROM THE SOUTH BY MID MORNING AT 8-12
KT...EXCEPT STRONGER...AT 10-15 KT AT KALB...WITH SOME GUSTS OF
20-25 KT POSSIBLE. SOUTH WINDS WILL GRADUALLY VEER INTO THE SW TO
W LATER THIS EVENING...AT 5-10 KT. WINDS WILL BE MUCH
STRONGER...AND VARIABLE IN DIRECTION IN AND NEAR ANY THUNDERSTORMS.
OUTLOOK...
SUN NIGHT...MVFR/IFR. SHRA/TSRA LIKELY EARLY.
MON...VFR. SLIGHT CHC -SHRA EAST OF THE HUDSON RIVER EARLY IN THE
MORNING.
TUE...VFR. NO SIG WX.
WED...VFR. SLIGHT CHC -SHRA/-TSRA.
THU...VFR. CHC OF -SHRA/-TSRA.
&&
.FIRE WEATHER...
WET FLAG CONDITIONS ARE EXPECTED FROM THIS AFTERNOON THROUGH TONIGHT.
A COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY AND CROSS THE
REGION TONIGHT. SHOWERS AND THUNDERSTORMS WILL PRECEDE AND ACCOMPANY
THIS BOUNDARY WITH SOME OF THE STORMS PRODUCING VERY HEAVY RAINFALL.
A MORE SEASONABLE AND DRIER AIRMASS WILL BE USHERED INTO OUR REGION
IN THE WAKE OF THE COLD FRONT FOR MONDAY AND TUESDAY.
&&
.HYDROLOGY...
A FLASH FLOOD WATCH IS IN EFFECT FOR ALL OF EASTERN NEW YORK AND
ADJACENT WESTERN NEW ENGLAND FROM 2 PM THIS AFTERNOON THROUGH EARLY
MONDAY MORNING.
A STRONG COLD FRONT WILL APPROACH OUR REGION FROM THE NORTHWEST
TODAY AND CROSS THE AREA TONIGHT. SHOWERS AND THUNDERSTORMS WILL
PRECEDE AND ACCOMPANY THIS BOUNDARY WITH SOME OF THE STORMS
PRODUCING VERY HEAVY RAINFALL.
INCREASING PRECIPITABLE WATER VALUES ARE EXPECTED THE FIRST HALF
OF TONIGHT RISING TO 2 TO PERHAPS AS HIGH AS 2.5 INCHES AHEAD OF
THE STRONG COLD FRONT. EXPECT THAT NUMEROUS SHOWERS AND
THUNDERSTORMS WILL OCCUR FROM LATER THIS AFTERNOON THROUGH LATE
TONIGHT WITH TORRENTIAL DOWNPOURS OCCURRING IN SOME AREAS. IN
ADDITION THUNDERSTORMS MAY TRAIN AND OR BACK BUILD ACROSS THE
SAME AREA INCREASING THE POSSIBILITY OF FLASH FLOODING. RAINFALL
AMOUNTS IN MANY AREAS WILL BE 1 TO 3 INCHES WITH 3 TO 6 INCHES OF
RAIN POSSIBLE IN AREAS WHERE THUNDERSTORMS TRAIN AND OR BACK
BUILD.
WHILE RIVER FLOODING IS GENERALLY NOT EXPECTED...SIGNIFICANT
WITHIN BANK RISES ARE EXPECTED ON SOME RIVERS.
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...FLASH FLOOD WATCH FROM 2 PM EDT THIS AFTERNOON THROUGH MONDAY
MORNING FOR CTZ001-013.
NY...FLASH FLOOD WATCH FROM 2 PM EDT THIS AFTERNOON THROUGH MONDAY
MORNING FOR NYZ032-033-038>043-047>054-058>061-063>066-
082>084.
MA...FLASH FLOOD WATCH FROM 2 PM EDT THIS AFTERNOON THROUGH MONDAY
MORNING FOR MAZ001-025.
VT...FLASH FLOOD WATCH FROM 2 PM EDT THIS AFTERNOON THROUGH MONDAY
MORNING FOR VTZ013>015.
&&
$$
SYNOPSIS...IAA/FRUGIS/11
NEAR TERM...11
SHORT TERM...11
LONG TERM...KL
AVIATION...FRUGIS/KL
FIRE WEATHER...11
HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS ALBANY NY
425 AM EDT SUN AUG 5 2012
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY AND CROSS THE
REGION TONIGHT. SHOWERS AND THUNDERSTORMS WILL PRECEDE AND ACCOMPANY
THIS BOUNDARY WITH SOME OF THE STORMS PRODUCING VERY HEAVY RAINFALL.
A MORE SEASONABLE AND DRIER AIRMASS WILL BE USHERED INTO OUR REGION
IN THE WAKE OF THE COLD FRONT FOR MONDAY AND TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 420 AM EDT...PARTLY TO MOSTLY CLOUDY SKIES PREVAILED ACROSS
THE FA WITH WARM AND MUGGY CONDITIONS. TEMPERATURES WERE GENERALLY
IN THE UPPER 60S TO MID 70S.
A VIGOROUS SHORT WAVE ACCOMPANIED BY A STRONG COLD FRONT WILL
IMPACT OUR REGION DURING THIS PERIOD WITH THE POSSIBILITY OF A
PRE-FRONTAL TROUGH CROSSING THE ALY FA LATE AFTERNOON INTO EARLY
EVENING WHICH MAY ENHANCE THE CONVECTION. THERE ARE MANY
INGREDIENTS IN PLACE FOR STRONG TO SEVERE THUNDERSTORMS AS WELL AS
HEAVY RAIN WHICH COULD PRODUCE FLASH FLOODING ESPECIALLY WHERE
CELLS TRAIN AND OR BACK BUILD. A FLASH FLOOD WATCH HAS BEEN ISSUED
FOR ALL OF EASTERN NEW YORK AND ADJACENT WESTERN NEW ENGLAND FROM
2 PM THIS AFTERNOON THROUGH EARLY MONDAY MORNING. THE TRAINING OF
CELLS IS A DISTINCT POSSIBILITY AS THE COLD FRONT IS EXPECTED TO
DROP FROM NORTHWEST TO SOUTHEAST AS THUNDERSTORMS MOVE FROM
SOUTHWEST TO NORTHEAST ALONG AND AHEAD OF IT. PWATS RISE TO 2 TO
NEARLY 2.5 INCHES THIS EVENING ALONG WITH A STRONG THETA E RIDGE
H10-H8...AND K INDEX VALUES BTWN 35 AND 40.
MLMUCAPES RISE UP TO 3000 J/KG THIS AFTERNOON WITH STRONG WIND
FIELDS AS FA ENDS UP IN RIGHT ENTRANCE REGION OF A CYCLONICALLY
CURVED 100+ KT JET ACRS ERN CANADA WHILE H8 WINDS INCREASE TO 35
TO 45 KTS AND H7 STEERING WINDS 35 TO 50 KTS FROM THE SOUTHWEST.
FURTHER 0-3 KM HELICITY VALUES INCREASE TO 150 TO 250 M2/S2
LATER THIS AFTERNOON INTO THIS EVENING. THUS THE POTENTIAL FOR
STRONG TO PERHAPS SEVERE WIND GUSTS EXIST WITH ANY STORMS AND SPC
HAS THE ALY FA OUTLOOKED AS SLIGHT RISK IN THE DAY 1 OUTLOOK. THE THREAT
OF LARGE HAIL IS CONSIDERABLY LESS AS WBZ HEIGHTS REMAIN ABOVE 12
KFT FOR MUCH OF THE PERIOD FROM THIS AFTERNOON THROUGH THIS EVENING.
HAVE CHANCE POPS INCREASING TO LIKELY POPS FROM NORTHWEST TO
SOUTHEAST DURING THE AFTERNOON INTO EARLY EVENING WITH LIKELY POPS
ACROSS ENTIRE FA FOR MUCH OF THE EVENING WITH DECREASING POPS
AFTER MIDNIGHT FROM NORTHWEST TO SOUTHEAST. EXPECT HIGHS TODAY GENERALLY
IN THE LOW TO MID 80S WITH LOWS TONIGHT GENERALLY IN THE 60S TO
LOWER 70S.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
ANY LINGERING SHOWERS OR THUNDERSTORMS ACROSS THE SOUTHEAST
PORTION OF THE FA ARE EXPECTED TO END EARLY MONDAY MORNING...OTHERWISE
DRIER...MORE SEASONABLE AND MUCH LESS HUMID CONDITIONS ARE
EXPECTED DURING THE SHORT TERM PERIOD WITH A GOOD DEAL OF SUNSHINE
ON BOTH MONDAY AND TUESDAY AND MAINLY CLEAR SKIES MONDAY NIGHT AND
TUESDAY NIGHT AS HIGH PRESSURE BUILDS ACROSS THE REGION. EXPECT
HIGHS ON MONDAY IN THE MID 70S TO MID 80S...LOWS MONDAY NIGHT IN
THE MID 50S TO LOWER 60S...HIGHS ON TUESDAY IN THE UPPER 70S TO
MID 80S AND LOWS TUESDAY NIGHT IN THE MID 50S TO MID 60S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
HAVE POPULATED THIS PORTION OF THE GRIDDED DATABASE WITH A 50/50
BLEND OF 18Z/04 HPC GUIDANCE AND 00Z/05 GMOS.
WED-THU NT...A WEAKENING SHORTWAVE WILL APPROACH FROM THE WEST LATE
WED...ALONG WITH AN ATTENDANT SURFACE BOUNDARY. FORCING ASSOCIATED
WITH THESE FEATURES MAY TRIGGER ISOLATED SHOWERS WED
AFTERNOON/EVENING ACROSS N/W AREAS...WHERE SLIGHT CHC POPS HAVE BEEN
INDICATED. THIS BOUNDARY IS THEN EXPECTED TO STALL ACROSS THE REGION
THU/THU NT. MARGINAL INSTABILITY...IN COMBINATION WITH WEAK FORCING
FROM FRONTAL BOUNDARY MAY PRODUCE ISOLATED TO SCATTERED
SHOWERS/THUNDERSTORMS ON THU...WHEN LOW CHC POPS ARE INDICATED.
EXPECT TEMPS TO AVERAGE ABOVE SEASONAL LEVELS...ALONG WITH
INCREASING HUMIDITY LEVELS DURING THIS TIME PERIOD...WITH DAYTIME
MAXES REACHING THE MID TO UPPER 80S IN VALLEYS...AND UPPER 70S TO
LOWER 80S ACROSS HIGHER ELEVATIONS. OVERNIGHT MINS SHOULD FALL INTO
THE LOWER/MID 60S IN VALLEYS...AND 55-60 ACROSS HIGHER ELEVATIONS.
FRI-SAT...CONFIDENCE INCREASING THAT A RATHER UNSETTLED PERIOD
SHOULD OCCUR...AS AN AMPLIFYING SHORTWAVE SLOWLY APPROACHES FROM THE
GREAT LAKES REGION...AND POTENTIALLY CLOSES OFF UPON APPROACHING
FROM THE WEST/SOUTHWEST. AT THE SURFACE...A WAVE...OR SERIES OF
WAVES ARE EXPECTED TO DEVELOP ALONG THE AFOREMENTIONED STALLED
FRONTAL BOUNDARY ACROSS THE REGION. THERE REMAINS SOME UNCERTAINTY
IN THE EXACT PLACEMENT AND DETAILS OF THE DEVELOPMENT OF ANY SFC
WAVE...AND MOVEMENT OF FRONTAL SYSTEMS AT THIS TIME RANGE...BUT AT
THE VERY LEAST...IT APPEARS THAT SEVERAL ROUNDS OF
SHOWERS/THUNDERSTORMS WILL BE POSSIBLE DURING THIS TIME PERIOD.
AND...DEPENDING ON HOW FAR SOUTH ANY SFC WAVE TRACKS...A PORTION OF
THE REGION COULD EVEN RECEIVE A STEADY...BENEFICIAL RAINFALL. HAVE
INCLUDED HIGH CHC POPS AT THIS TIME. GIVEN THE UNCERTAINTY IN
FRONTAL BOUNDARIES WITH THIS SYSTEM...TEMPERATURES REMAIN
TRICKY...AS A MORE SOUTHERN TRACK WITH THE LOW WOULD FAVOR NEAR
OR EVEN BELOW NORMAL DAYTIME MAXES. FOR NOW...HAVE SIDED WITH THE
AFOREMENTIONED 50/50 BLEND OF HPC GUIDANCE AND GMOS...WITH DAYTIME
MAXES IN THE LOWER 80S IN VALLEYS...AND 70S ELSEWHERE...AND
OVERNIGHT MINS MAINLY IN THE 60S AS CLOUDS AND HIGHER HUMIDITY
LEVELS KEEP NIGHTTIME TEMPS RELATIVELY WARM.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
A COLD FRONT APPROACHING FROM THE WEST WILL TRIGGER NUMEROUS
SHOWERS AND THUNDERSTORMS THIS AFTERNOON INTO THE FIRST HALF OF
TONIGHT.
VFR CONDITIONS WILL GRADUALLY BECOME MVFR...MAINLY FOR CIGS...AS
LOW STRATUS ADVECTS AND/OR DEVELOPS NORTHWARD THROUGH SUNRISE.
TRICKY CALL ON WHETHER IT REMAINS LOW MVFR...OR IFR. AT THIS
TIME...FOLLOWED CLOSE TO THE HRRR OUTPUT...WHICH IMPLIES MAINLY
MVFR CIGS INITIALLY...WITH A CHANCE FOR IFR AFTER 09Z/SUN AT ALL
TAF SITES. HOWEVER...LOCAL DOWNSLOPING WITH A S/SE FLOW MAY
PREVENT CIGS FROM CRASHING TO IFR AT KPSF AND KPOU. HAVE INDICATED
ONLY BRIEF PERIODS OF IFR TOWARD 12Z/SUN AT THESE LOCATIONS.
THIS STRATUS MAY BEGIN TO BREAK UP SUNDAY MORNING AS THE FRONTAL
BOUNDARY BEGINS TO APPROACH...AND THE FLOW BECOMES MORE SW.
CONDITIONS SHOULD GO BACK TO VFR AT ALL SITES BY THE LATE MORNING
HOURS. SOME SHOWERS AND TSTMS ARE POSSIBLE BY LATE IN THE DAY INTO
SUNDAY NIGHT AS THE FRONT CROSSES THE REGION. HAVE INDICATED A
VCTS FOR ALL TAF SITES AFTER 18Z-20Z/SUN...AS THUNDERSTORMS SHOULD
BECOME RATHER NUMEROUS LATER THIS AFTERNOON...WELL INTO THIS
EVENING. IT IS LIKELY THAT SEVERAL DISCRETE ROUNDS OF
THUNDERSTORMS OCCUR DURING THIS TIME PERIOD...WITH SOME BREAKS IN
BETWEEN.
THE THREAT FOR THUNDERSTORMS WILL GRADUALLY DECREASE TOWARD AND
ESP AFTER 06Z/MON...FIRST AT KGFL AND KALB...AND LAST AT KPSF AND
KPOU. AREAS OF MVFR/IFR FOG MAY OCCUR TOWARD AND AFTER 06Z/MON AT ALL
TAF SITES.
SOUTH/SOUTHEAST WINDS WILL PERSIST THROUGH DAYBREAK AT KALB AND
8-12 KT...WITH SOME GUSTS POSSIBLY REACHING 15-20 KT.
ELSEWHERE...WINDS SHOULD BECOME LIGHT/VARIABLE THROUGH DAYBREAK.
WINDS WILL THEN INCREASE FROM THE SOUTH BY MID MORNING AT 8-12
KT...EXCEPT STRONGER...AT 10-15 KT AT KALB...WITH SOME GUSTS OF
20-25 KT POSSIBLE. SOUTH WINDS WILL GRADUALLY VEER INTO THE SW TO
W LATER THIS EVENING...AT 5-10 KT. WINDS WILL BE MUCH
STRONGER...AND VARIABLE IN DIRECTION IN AND NEAR ANY THUNDERSTORMS.
OUTLOOK...
SUN NIGHT...MVFR/IFR. SHRA/TSRA LIKELY EARLY.
MON...VFR. SLIGHT CHC -SHRA EAST OF THE HUDSON RIVER EARLY IN THE
MORNING.
TUE...VFR. NO SIG WX.
WED...VFR. SLIGHT CHC -SHRA/-TSRA.
THU...VFR. CHC OF -SHRA/-TSRA.
&&
.FIRE WEATHER...
WET FLAG CONDITIONS ARE EXPECTED FROM THIS AFTERNOON THROUGH TONIGHT.
A COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY AND CROSS THE
REGION TONIGHT. SHOWERS AND THUNDERSTORMS WILL PRECEDE AND ACCOMPANY
THIS BOUNDARY WITH SOME OF THE STORMS PRODUCING VERY HEAVY RAINFALL.
A MORE SEASONABLE AND DRIER AIRMASS WILL BE USHERED INTO OUR REGION
IN THE WAKE OF THE COLD FRONT FOR MONDAY AND TUESDAY.
&&
.HYDROLOGY...
A FLASH FLOOD WATCH IS IN EFFECT FOR ALL OF EASTERN NEW YORK AND
ADJACENT WESTERN NEW ENGLAND FROM 2 PM THIS AFTERNOON THROUGH EARLY
MONDAY MORNING.
A STRONG COLD FRONT WILL APPROACH OUR REGION FROM THE NORTHWEST
TODAY AND CROSS THE AREA TONIGHT. SHOWERS AND THUNDERSTORMS WILL
PRECEDE AND ACCOMPANY THIS BOUNDARY WITH SOME OF THE STORMS
PRODUCING VERY HEAVY RAINFALL.
INCREASING PRECIPITABLE WATER VALUES ARE EXPECTED THE FIRST HALF
OF TONIGHT RISING TO 2 TO PERHAPS AS HIGH AS 2.5 INCHES AHEAD OF
THE STRONG COLD FRONT. EXPECT THAT NUMEROUS SHOWERS AND
THUNDERSTORMS WILL OCCUR FROM LATER THIS AFTERNOON THROUGH LATE
TONIGHT WITH TORRENTIAL DOWNPOURS OCCURRING IN SOME AREAS. IN
ADDITION THUNDERSTORMS MAY TRAIN AND OR BACK BUILD ACROSS THE
SAME AREA INCREASING THE POSSIBILITY OF FLASH FLOODING. RAINFALL
AMOUNTS IN MANY AREAS WILL BE 1 TO 3 INCHES WITH 3 TO 6 INCHES OF
RAIN POSSIBLE IN AREAS WHERE THUNDERSTORMS TRAIN AND OR BACK
BUILD.
WHILE RIVER FLOODING IS GENERALLY NOT EXPECTED...SIGNIFICANT
WITHIN BANK RISES ARE EXPECTED ON SOME RIVERS.
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...FLASH FLOOD WATCH FROM 2 PM EDT THIS AFTERNOON THROUGH MONDAY
MORNING FOR CTZ001-013.
NY...FLASH FLOOD WATCH FROM 2 PM EDT THIS AFTERNOON THROUGH MONDAY
MORNING FOR NYZ032-033-038>043-047>054-058>061-063>066-
082>084.
MA...FLASH FLOOD WATCH FROM 2 PM EDT THIS AFTERNOON THROUGH MONDAY
MORNING FOR MAZ001-025.
VT...FLASH FLOOD WATCH FROM 2 PM EDT THIS AFTERNOON THROUGH MONDAY
MORNING FOR VTZ013>015.
&&
$$
SYNOPSIS...IAA/FRUGIS/11
NEAR TERM...11
SHORT TERM...11
LONG TERM...KL
AVIATION...FRUGIS/KL
FIRE WEATHER...11
HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS ALBANY NY
144 AM EDT SUN AUG 5 2012
.SYNOPSIS...
TONIGHT WILL BE WARM AND MUGGY. A COLD FRONT WILL
APPROACH FROM THE NORTHWEST SUNDAY AND CROSS THE REGION AT NIGHT.
SHOWERS AND THUNDERSTORMS WILL PRECEDE AND ACCOMPANY THIS BOUNDARY
WITH SOME OF THE STORMS PRODUCING VERY HEAVY RAINFALL. A
COOLER...MORE SEASONABLE AND DRIER AIRMASS WILL BE USHERED IN THE
WAKE OF THE COLD FRONT FOR EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 120 AM EDT...MAINLY CLEAR SKIES HAVE GIVEN WAY TO PARTLY TO
MOSTLY CLOUDY SKIES ACRS THE SRN HLF OF THE FA AS LOW STRATUS HAS
STARTED TO LIFT NORTHWARD FROM SOUTHEAST NY AND SW NEW ENGLAND.
EXPECT THIS TREND TO CONTINUE WITH SKIES BECOMING PARTLY TO
MOSTLY CLOUDY LATER TONIGHT ACRS THE ENTIRE FA. THERE MAY BE SOME
RADIATIONAL FOG IN SPOTS...BUT IT WILL DEPEND ON HOW QUICKLY THE
STRATUS SPREADS INTO THE REGION. IT WILL REMAIN MUGGY
OVERNIGHT...AND MIN TEMPS WILL BE IN THE 70S IN THE CAPITAL REGION
OVERNIGHT...WITH MID TO UPPER 60S ELSEWHERE.
AN MCS IS CURRENTLY ONGOING ACROSS OHIO. THERE HAS BEEN PLENTY OF
CG LTG ACTIVITY WITH THIS STRONG BATCH OF CONVECTION AHEAD OF A
POTENT COLD FRONT. THE 00 UTC NAM AND LATEST 01 UTC 3KM HRRR DO
NOT HAVE A GOOD HANDLE ON THIS CURRENT ONGOING ACTIVITY.
CONSIDERING THAT THE UPPER TROUGH APPEARS TO BE IN THE PROCESS OF
SHEARING OUT...WE DON/T ANTICIPATE THIS ACTIVITY MAKING IT INTO
OUR AREA BY THE LATE NIGHT HOURS...BUT WE WILL CONTINUE TO MONITOR
RADAR TRENDS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
THE STORM PREDICTION CENTER CONTINUES TO HAVE THE FORECAST AREA
IN A SLIGHT RISK FOR THUNDERSTORMS IN THE DAY 2 OUTLOOK. HOWEVER
TO NOTE THE AREA OUTLINED BY THE 30 PERCENT COMBINED PROBABILISTIC
OUTLOOK FOR SEVERE WEATHER HAS BEEN DECREASED. ALL BUT THE NORTHWEST
CORNER OF OUR FORECAST AREA IS NOW UNDER THE 15 PERCENT PROBABILISTIC
OUTLOOK.
THE MODEL GUIDANCE IS IN FAIRLY GOOD AGREEMENT WITH THE TIMING OF
THE COLD FRONT WHICH WILL NOT CROSS THE AREA UNTIL SUNDAY NIGHT. THE
UPPER TROUGH AXIS WILL MOVE ACROSS THE GREAT LAKES REGION DURING THE
DAYTIME AND ACROSS EASTERN CANADA SUNDAY NIGHT. NOT MUCH IN THE WAY
OF HEIGHT FALLS WILL OCCUR ACROSS OUR REGION. THE BEST DYNAMICS WILL
REMAINS JUST TO OUR NORTH AND WEST. MID LEVEL LAPSE RATES WILL BE
RATHER WEAK AROUND 5.5 C/KM. MODELS INDICATE MARGINAL INSTABILITY.
500 MB TEMPERATURES WILL WARM TO AROUND -6C WHICH WILL LIMIT
DESTABILIZATION. THE 0-6KM BULK SHEAR OF 20 TO 25 KNOTS WILL
INCREASE TO 30 TO 40 KNOTS SUNDAY NIGHT. HAVE POPS INCREASING TO
LIKELY DURING THE AFTERNOON INTO THE EVENING HOURS.
VALUES ARE STILLED MODELED TO INCREASE TO 2-2.25 INCHES ACROSS THE
AREA AHEAD OF THE APPROACHING COLD FRONT...SO VERY HEAVY/TORRENTIAL
DOWNPOURS WILL BE EXPECTED WITH SOME STORMS. THE HEAVY RAINS COULD
RESULT IN LOCALIZED FLOODING OF LOW LYING AND POOR DRAINAGE AREAS.
AND IF TRAINING OF THUNDERSTORMS OCCURS THEN ISOLATED FLASH FLOODING
WOULD BE POSSIBLE. WILL KEEP THIS HIGHLIGHTED IN OUR HAZARDOUS
WEATHER OUTLOOK AND KEEP HEAVY RAINFALL MENTIONED IN FORECAST.
THE HOT AND HUMID AIRMASS WILL BE REPLACED BY A COOLER...MORE
SEASONABLE AND DRIER AIRMASS TO START THE WEEK.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HPC GUIDANCE. ANOTHER INCLEMENT SUMMER PATTERN SETS UP WITH A
CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY FROM THURSDAY THROUGH
THE END OF THE WEEK. LOW PRESSURE OFF THE CANADIAN ROCKIES WILL
TRACK FROM THE NORTHERN PLAINS THROUGH THE GREAT LAKES REGION
THROUGH SATURDAY. A COLD FRONT AHEAD OF THE LOW PRESSING SOUTH
ACROSS THE FORECAST AREA ON THURSDAY BEGINS THE PATTERN. JUST AHEAD
OF THE LOW ON SATURDAY IT RETURNS AS A WARM FRONT...WITH THE MAIN
COLD FRONT SLIDING EAST ACROSS THE AREA EARLY SATURDAY. THE TIMING
OF THIS LATTER FRONTAL PASSAGE WILL DECIDE THE EXTEND OF ANY
REMAINING THUNDERSTORM ACTIVITY ON SATURDAY AS HIGH PRESSURE WILL BE
MAKING A RETURN.
HIGH TEMPERATURES WEDNESDAY AND THURSDAY WILL RANGE MAINLY FROM
AROUND 80 DEGREES IN THE HIGH ELEVATIONS...TO AROUND 90 IN THE
MOHAWK AND HUDSON VALLEYS. HIGHS FRIDAY WILL BE FROM THE MID 70S TO
MID 80S...WITH SLIGHTLY COOLER READINGS FOR SATURDAY. LOWS WILL
START OFF TUESDAY NIGHT FROM MAINLY THE UPPER 50S TO MID 60S. THE
NIGHT WILL BECOMING INCREASINGLY MILDER...HOWEVER...WITH LOWS FRIDAY
NIGHT MAINLY FROM THE MID 60S TO AROUND 70 DEGREES.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
A COLD FRONT APPROACHING FROM THE WEST WILL TRIGGER NUMEROUS
SHOWERS AND THUNDERSTORMS THIS AFTERNOON INTO THE FIRST HALF OF
TONIGHT.
VFR CONDITIONS WILL GRADUALLY BECOME MVFR...MAINLY FOR CIGS...AS
LOW STRATUS ADVECTS AND/OR DEVELOPS NORTHWARD THROUGH SUNRISE.
TRICKY CALL ON WHETHER IT REMAINS LOW MVFR...OR IFR. AT THIS
TIME...FOLLOWED CLOSE TO THE HRRR OUTPUT...WHICH IMPLIES MAINLY
MVFR CIGS INITIALLY...WITH A CHANCE FOR IFR AFTER 09Z/SUN AT ALL
TAF SITES. HOWEVER...LOCAL DOWNSLOPING WITH A S/SE FLOW MAY
PREVENT CIGS FROM CRASHING TO IFR AT KPSF AND KPOU. HAVE INDICATED
ONLY BRIEF PERIODS OF IFR TOWARD 12Z/SUN AT THESE LOCATIONS.
THIS STRATUS MAY BEGIN TO BREAK UP SUNDAY MORNING AS THE FRONTAL
BOUNDARY BEGINS TO APPROACH...AND THE FLOW BECOMES MORE SW.
CONDITIONS SHOULD GO BACK TO VFR AT ALL SITES BY THE LATE MORNING
HOURS. SOME SHOWERS AND TSTMS ARE POSSIBLE BY LATE IN THE DAY INTO
SUNDAY NIGHT AS THE FRONT CROSSES THE REGION. HAVE INDICATED A
VCTS FOR ALL TAF SITES AFTER 18Z-20Z/SUN...AS THUNDERSTORMS SHOULD
BECOME RATHER NUMEROUS LATER THIS AFTERNOON...WELL INTO THIS
EVENING. IT IS LIKELY THAT SEVERAL DISCRETE ROUNDS OF
THUNDERSTORMS OCCUR DURING THIS TIME PERIOD...WITH SOME BREAKS IN
BETWEEN.
THE THREAT FOR THUNDERSTORMS WILL GRADUALLY DECREASE TOWARD AND
ESP AFTER 06Z/MON...FIRST AT KGFL AND KALB...AND LAST AT KPSF AND
KPOU. AREAS OF MVFR/IFR FOG MAY OCCUR TOWARD AND AFTER 06Z/MON AT ALL
TAF SITES.
SOUTH/SOUTHEAST WINDS WILL PERSIST THROUGH DAYBREAK AT KALB AND
8-12 KT...WITH SOME GUSTS POSSIBLY REACHING 15-20 KT.
ELSEWHERE...WINDS SHOULD BECOME LIGHT/VARIABLE THROUGH DAYBREAK.
WINDS WILL THEN INCREASE FROM THE SOUTH BY MID MORNING AT 8-12
KT...EXCEPT STRONGER...AT 10-15 KT AT KALB...WITH SOME GUSTS OF
20-25 KT POSSIBLE. SOUTH WINDS WILL GRADUALLY VEER INTO THE SW TO
W LATER THIS EVENING...AT 5-10 KT. WINDS WILL BE MUCH
STRONGER...AND VARIABLE IN DIRECTION IN AND NEAR ANY THUNDERSTORMS.
OUTLOOK...
SUN NIGHT...MVFR/IFR. SHRA/TSRA LIKELY EARLY.
MON...VFR. SLIGHT CHC -SHRA EAST OF THE HUDSON RIVER EARLY IN THE
MORNING.
TUE...VFR. NO SIG WX.
WED...VFR. SLIGHT CHC -SHRA/-TSRA.
THU...VFR. CHC OF -SHRA/-TSRA.
&&
.FIRE WEATHER...
TONIGHT WILL BE WARM AND MUGGY. A COLD FRONT WILL APPROACH FROM
THE NORTHWEST SUNDAY AND CROSS THE REGION AT NIGHT. SHOWERS AND
THUNDERSTORMS WILL PRECEDE AND ACCOMPANY THIS BOUNDARY WITH SOME
OF THE STORMS PRODUCING VERY HEAVY RAINFALL. A COOLER...MORE
SEASONABLE AND DRIER AIRMASS WILL BE USHERED IN THE WAKE OF THE
COLD FRONT.
&&
.HYDROLOGY...
TONIGHT WILL BE WARM AND MUGGY. A COLD FRONT WILL APPROACH FROM
THE NORTHWEST SUNDAY AND CROSS THE REGION AT NIGHT. SHOWERS AND
THUNDERSTORMS WILL PRECEDE AND ACCOMPANY THIS BOUNDARY WITH SOME
OF THE STORMS PRODUCING VERY HEAVY RAINFALL. A COOLER...MORE
SEASONABLE AND DRIER AIRMASS WILL BE USHERED IN THE WAKE OF THE
COLD FRONT.
CONVECTION HAS BEEN FORMING MAINLY ON THE HIGHER TERRAIN OF
THE SOUTHERN GREEN MOUNTAINS THIS AFTERNOON. SINCE PRECIPITABLE
WATER VALUES ARE HIGH ACROSS AREA HAVE HAD HEAVY RAINFALL WITH
SOME STORMS. THERE HAS BEEN TRAINING OF STORMS ALONG THE
BERKSHIRE/FRANKLIN COUNTY BORDER. CONVECTION WILL DIMINISH WITH
LOSS OF HEATING.
VALUES ARE STILLED MODELED TO INCREASE TO 2-2.25 INCHES ACROSS THE
AREA AHEAD OF THE APPROACHING COLD FRONT...SO VERY HEAVY/TORRENTIAL
DOWNPOURS WILL BE EXPECTED WITH SOME STORMS. THE HEAVY RAINS COULD
RESULT IN LOCALIZED FLOODING OF LOW LYING AND POOR DRAINAGE AREAS.
AND IF TRAINING OF THUNDERSTORMS OCCURS THEN ISOLATED FLASH FLOODING
WOULD BE POSSIBLE. WILL KEEP THIS HIGHLIGHTED IN OUR HAZARDOUS
WEATHER OUTLOOK AND KEEP HEAVY RAINFALL MENTIONED IN FORECAST.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...IAA/FRUGIS
NEAR TERM...FRUGIS/11
SHORT TERM...IAA
LONG TERM...ELH
AVIATION...KL/FRUGIS
FIRE WEATHER...IAA
HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS ALBANY NY
127 AM EDT SUN AUG 5 2012
.SYNOPSIS...
TONIGHT WILL BE WARM AND MUGGY. A COLD FRONT WILL
APPROACH FROM THE NORTHWEST SUNDAY AND CROSS THE REGION AT NIGHT.
SHOWERS AND THUNDERSTORMS WILL PRECEDE AND ACCOMPANY THIS BOUNDARY
WITH SOME OF THE STORMS PRODUCING VERY HEAVY RAINFALL. A
COOLER...MORE SEASONABLE AND DRIER AIRMASS WILL BE USHERED IN THE
WAKE OF THE COLD FRONT FOR EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 120 AM EDT...MAINLY CLEAR SKIES HAVE GIVEN WAY TO PARTLY TO
MOSTLY CLOUDY SKIES ACRS THE SRN HLF OF THE FA AS LOW STRATUS HAS
STARTED TO LIFT NORTHWARD FROM SOUTHEAST NY AND SW NEW ENGLAND.
EXPECT THIS TREND TO CONTINUE WITH SKIES BECOMING PARTLY TO
MOSTLY CLOUDY LATER TONIGHT ACRS THE ENTIRE FA. THERE MAY BE SOME
RADIATIONAL FOG IN SPOTS...BUT IT WILL DEPEND ON HOW QUICKLY THE
STRATUS SPREADS INTO THE REGION. IT WILL REMAIN MUGGY
OVERNIGHT...AND MIN TEMPS WILL BE IN THE 70S IN THE CAPITAL REGION
OVERNIGHT...WITH MID TO UPPER 60S ELSEWHERE.
AN MCS IS CURRENTLY ONGOING ACROSS OHIO. THERE HAS BEEN PLENTY OF
CG LTG ACTIVITY WITH THIS STRONG BATCH OF CONVECTION AHEAD OF A
POTENT COLD FRONT. THE 00 UTC NAM AND LATEST 01 UTC 3KM HRRR DO
NOT HAVE A GOOD HANDLE ON THIS CURRENT ONGOING ACTIVITY.
CONSIDERING THAT THE UPPER TROUGH APPEARS TO BE IN THE PROCESS OF
SHEARING OUT...WE DON/T ANTICIPATE THIS ACTIVITY MAKING IT INTO
OUR AREA BY THE LATE NIGHT HOURS...BUT WE WILL CONTINUE TO MONITOR
RADAR TRENDS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
THE STORM PREDICTION CENTER CONTINUES TO HAVE THE FORECAST AREA
IN A SLIGHT RISK FOR THUNDERSTORMS IN THE DAY 2 OUTLOOK. HOWEVER
TO NOTE THE AREA OUTLINED BY THE 30 PERCENT COMBINED PROBABILISTIC
OUTLOOK FOR SEVERE WEATHER HAS BEEN DECREASED. ALL BUT THE NORTHWEST
CORNER OF OUR FORECAST AREA IS NOW UNDER THE 15 PERCENT PROBABILISTIC
OUTLOOK.
THE MODEL GUIDANCE IS IN FAIRLY GOOD AGREEMENT WITH THE TIMING OF
THE COLD FRONT WHICH WILL NOT CROSS THE AREA UNTIL SUNDAY NIGHT. THE
UPPER TROUGH AXIS WILL MOVE ACROSS THE GREAT LAKES REGION DURING THE
DAYTIME AND ACROSS EASTERN CANADA SUNDAY NIGHT. NOT MUCH IN THE WAY
OF HEIGHT FALLS WILL OCCUR ACROSS OUR REGION. THE BEST DYNAMICS WILL
REMAINS JUST TO OUR NORTH AND WEST. MID LEVEL LAPSE RATES WILL BE
RATHER WEAK AROUND 5.5 C/KM. MODELS INDICATE MARGINAL INSTABILITY.
500 MB TEMPERATURES WILL WARM TO AROUND -6C WHICH WILL LIMIT
DESTABILIZATION. THE 0-6KM BULK SHEAR OF 20 TO 25 KNOTS WILL
INCREASE TO 30 TO 40 KNOTS SUNDAY NIGHT. HAVE POPS INCREASING TO
LIKELY DURING THE AFTERNOON INTO THE EVENING HOURS.
VALUES ARE STILLED MODELED TO INCREASE TO 2-2.25 INCHES ACROSS THE
AREA AHEAD OF THE APPROACHING COLD FRONT...SO VERY HEAVY/TORRENTIAL
DOWNPOURS WILL BE EXPECTED WITH SOME STORMS. THE HEAVY RAINS COULD
RESULT IN LOCALIZED FLOODING OF LOW LYING AND POOR DRAINAGE AREAS.
AND IF TRAINING OF THUNDERSTORMS OCCURS THEN ISOLATED FLASH FLOODING
WOULD BE POSSIBLE. WILL KEEP THIS HIGHLIGHTED IN OUR HAZARDOUS
WEATHER OUTLOOK AND KEEP HEAVY RAINFALL MENTIONED IN FORECAST.
THE HOT AND HUMID AIRMASS WILL BE REPLACED BY A COOLER...MORE
SEASONABLE AND DRIER AIRMASS TO START THE WEEK.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HPC GUIDANCE. ANOTHER INCLEMENT SUMMER PATTERN SETS UP WITH A
CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY FROM THURSDAY THROUGH
THE END OF THE WEEK. LOW PRESSURE OFF THE CANADIAN ROCKIES WILL
TRACK FROM THE NORTHERN PLAINS THROUGH THE GREAT LAKES REGION
THROUGH SATURDAY. A COLD FRONT AHEAD OF THE LOW PRESSING SOUTH
ACROSS THE FORECAST AREA ON THURSDAY BEGINS THE PATTERN. JUST AHEAD
OF THE LOW ON SATURDAY IT RETURNS AS A WARM FRONT...WITH THE MAIN
COLD FRONT SLIDING EAST ACROSS THE AREA EARLY SATURDAY. THE TIMING
OF THIS LATTER FRONTAL PASSAGE WILL DECIDE THE EXTEND OF ANY
REMAINING THUNDERSTORM ACTIVITY ON SATURDAY AS HIGH PRESSURE WILL BE
MAKING A RETURN.
HIGH TEMPERATURES WEDNESDAY AND THURSDAY WILL RANGE MAINLY FROM
AROUND 80 DEGREES IN THE HIGH ELEVATIONS...TO AROUND 90 IN THE
MOHAWK AND HUDSON VALLEYS. HIGHS FRIDAY WILL BE FROM THE MID 70S TO
MID 80S...WITH SLIGHTLY COOLER READINGS FOR SATURDAY. LOWS WILL
START OFF TUESDAY NIGHT FROM MAINLY THE UPPER 50S TO MID 60S. THE
NIGHT WILL BECOMING INCREASINGLY MILDER...HOWEVER...WITH LOWS FRIDAY
NIGHT MAINLY FROM THE MID 60S TO AROUND 70 DEGREES.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS ARE IN PLACE AT ALL TAF SITES THIS EVENING WITH JUST
FEW CU STILL AROUND. SKIES MAY BRIEFLY GO CLEAR FOR THE EVENING
HOURS WHICH WILL ALLOW FOR SOME RADIATIONAL COOLING AS THESE CU
DISSIPATE WITH THE LOSS OF DAYTIME HEATING. THIS MAY LEAD TO SOME
RADIATIONAL FOG STARTING TO DEVELOP...MAINLY FOR THE TYPICAL SPOTS
/KGFL AND KPSF/ TOWARDS OR JUST AFTER MIDNIGHT.
AT THE SAME TIME...A SOUTHERLY FLOW WILL ADVECT WARM AND MOIST AIR
INTO THE REGION FROM THE ATLANTIC. THIS WILL ALLOW SOME IFR
STRATUS TO DEVELOP OVERNIGHT. STRATUS WILL DEVELOP FIRST IN THE
SOUTH BY KPOU/KPSF BY AROUND 06Z...AND MOVE UP THE HUDSON VALLEY
DURING THE REMAINDER OF THE OVERNIGHT HOURS. EVEN KALB/KGFL MAY
SEE SOME IFR STRATUS TOWARDS THE LATE NIGHT HOURS.
THIS STRATUS MAY BEGIN TO BREAK UP ON SUNDAY MORNING AS A FRONTAL
BOUNDARY BEGINS TO APPROACH...AND THE FLOW BECOMES MORE WSW.
CONDITIONS SHOULD GO BACK TO VFR AT ALL SITES BY THE LATE MORNING
HOURS. SOME SHOWERS AND EVEN TSTMS ARE POSSIBLE BY LATE IN THE DAY
OR SUNDAY NIGHT AS THE FRONT CROSSES THE REGION. DUE TO
UNCERTAINTY REGARDING TIMING/EXTENT OF SHOWERS/STORMS...WILL ONLY
GO WITH A VCSH AT THIS TIME FOR THE AFTN HOURS AT ALL SITES.
OUTLOOK...
SUN NIGHT...MVFR/IFR. SHRA/TSRA LIKELY.
MON...VFR. SLIGHT CHC -SHRA EAST OF THE HUDSON RIVER EARLY IN THE
MORNING.
TUE...VFR. NO SIG WX.
WED...VFR. SLIGHT CHC -SHRA/-TSRA.
THU...VFR. CHC OF -SHRA/-TSRA.
&&
.FIRE WEATHER...
TONIGHT WILL BE WARM AND MUGGY. A COLD FRONT WILL APPROACH FROM
THE NORTHWEST SUNDAY AND CROSS THE REGION AT NIGHT. SHOWERS AND
THUNDERSTORMS WILL PRECEDE AND ACCOMPANY THIS BOUNDARY WITH SOME
OF THE STORMS PRODUCING VERY HEAVY RAINFALL. A COOLER...MORE
SEASONABLE AND DRIER AIRMASS WILL BE USHERED IN THE WAKE OF THE
COLD FRONT.
&&
.HYDROLOGY...
TONIGHT WILL BE WARM AND MUGGY. A COLD FRONT WILL APPROACH FROM
THE NORTHWEST SUNDAY AND CROSS THE REGION AT NIGHT. SHOWERS AND
THUNDERSTORMS WILL PRECEDE AND ACCOMPANY THIS BOUNDARY WITH SOME
OF THE STORMS PRODUCING VERY HEAVY RAINFALL. A COOLER...MORE
SEASONABLE AND DRIER AIRMASS WILL BE USHERED IN THE WAKE OF THE
COLD FRONT.
CONVECTION HAS BEEN FORMING MAINLY ON THE HIGHER TERRAIN OF
THE SOUTHERN GREEN MOUNTAINS THIS AFTERNOON. SINCE PRECIPITABLE
WATER VALUES ARE HIGH ACROSS AREA HAVE HAD HEAVY RAINFALL WITH
SOME STORMS. THERE HAS BEEN TRAINING OF STORMS ALONG THE
BERKSHIRE/FRANKLIN COUNTY BORDER. CONVECTION WILL DIMINISH WITH
LOSS OF HEATING.
VALUES ARE STILLED MODELED TO INCREASE TO 2-2.25 INCHES ACROSS THE
AREA AHEAD OF THE APPROACHING COLD FRONT...SO VERY HEAVY/TORRENTIAL
DOWNPOURS WILL BE EXPECTED WITH SOME STORMS. THE HEAVY RAINS COULD
RESULT IN LOCALIZED FLOODING OF LOW LYING AND POOR DRAINAGE AREAS.
AND IF TRAINING OF THUNDERSTORMS OCCURS THEN ISOLATED FLASH FLOODING
WOULD BE POSSIBLE. WILL KEEP THIS HIGHLIGHTED IN OUR HAZARDOUS
WEATHER OUTLOOK AND KEEP HEAVY RAINFALL MENTIONED IN FORECAST.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...IAA/FRUGIS
NEAR TERM...FRUGIS/11
SHORT TERM...IAA
LONG TERM...ELH
AVIATION...FRUGIS
FIRE WEATHER...IAA
HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
909 PM EDT Mon Aug 6 2012
.SYNOPSIS...
The large scale longwave pattern is highlighted by ridging over the
wrn states and in the nrn stream, a broad trough ewd to ern seaboard
and in srn stream, weak ridging ewd into wrn Atlc. Main feature is
is deep layer low (altho primarily H5 system) in SE AL just N of FL
border allowing H7/H3 cyclonic flow and deep layer moisture to
advect NWD from Gulf. At surface, low off Canadian Maritimes with
cold front SWD then quasi-stnry front swwd across Memphis into Srn
Plains. High well east of Carolinas with axis wsw across SE states.
Of particular local interest is tropical wave/inverted trough with
assocd low on SE AL/FL Panhandle border. During rest of this eve,
low will jog to over SE AL with wave axis SWD into Atlc. East of the
trough axis, moisture will continue lifting NWWD and wrap around
tropical wave across the local region.
.NEAR TERM [Until 6 AM Tuesday Morning]...
Some of the higher resolution models, including our local 4km
WRF-ARW and the RAP showed a brief respite in the convective
activity through the late evening and this is reflected in current
radar pix. However the exception is Leon country and adjacent
portions on neighboring counties where satellite shows banding of
convection into area. Likewise MSAS shows cyclonic feature set up
near Liberty County while moisture rotating NWD into Leon country.
As a result convective band seemed to set up earlier in aftn and
persists in persists into the late eve yielding showers and tstms.
Additional showers and storms should develop overnight across CWA
especially if one or two weak vort centers interact with moisture.
The focus will be on Wrn third of our area. However, the coverage
and intensity on radar noticeably less than same time yesterday as
wave axis/low continue to push WWD. Therefore tweaked down inherited
POPs to 30-50% NW-SW overnight. Much of the area grounds remain wet
from recent rains and areas RAOBs continue with juicy soundings with
over 2 inch PWs. So brief heavy rain possible and this could
generate localized flooding. The areas most susceptible would be the
SE AL, SW GA and adjacent FL Panhandle.
&&
.SHORT TERM [Tuesday Through Wednesday Night]...
An elongated upper trough from the Cntrl gulf coast NWD will
dominate the regional weather pattern thru the period. At lower
levels, the main feature for Tuesday will be tropical wave exiting
wwd across the Cntrl Gulf with assocd low will begin to lift NEWD
over Srn AL/GA while another was waiting in the wings across eastern
Florida. This lifting low should keep upstream front well north of
our area. In addition to the surface features, the upper and mid
level troughs will expand/dig into the Southeast, providing a bit
more synoptic scale forcing for ascent. These combined will keep
rain chances well above average on Tuesday, and high temperatures
just below average. By Wednesday, the surface subtropical ridge will
begin to nose back in from the east and start to shunt the pesky
tropical waves out of the local area. However, it won`t be until
late Thursday that ridge becomes a factor, and until then the upper
level trough will remain in place, so we will probably still have
plenty of shower and thunderstorm activity across our western
forecast area. Thus, rain chances will remain above average thru the
period.
&&
.AVIATION [through 00Z Wednesday]...
Unsettled conditions continue as a tropical wave resides over the
western portion of the tri-state region pumping deep tropical
moisture northward from the gulf. The trend in most of the TAFs was
for a gradual lowering of CIGS and VIS overnight with the timing
uncertain for individual SHRA and TS.
&&
.MARINE...thru Tonight...
Mid Evening buoys out to beyond 60nm form the coast show light winds
and nearly calm seas. They should remain so thru overnight period.
The swells and rip current risk will begin increasing by Wednesday
due to the impact of distant TS Ernesto.
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
BLOCK/BARRY
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
1014 PM EDT MON AUG 6 2012
.UPDATE...
MAIN AREA OF PERSISTENT CONVECTIVE DEVELOPMENT PAST DIURNAL
HEATING HAS BEEN ACROSS THE NORTHERN PORTION OF THE AREA ALONG AN
AXIS OF SFC CONVERGENCE. AS WEAK UPPER LOW CONTINUES TO BE
CENTERED NEAR SW GA...A MOIST TROPICAL AIRMASS REMAINS IN PLACE
WITH PWATS OF 2 INCHES OR GREATER. ANY REMNANT BOUNDARY OR WEAK
FORCING FOR ASCENT WILL MAINTAIN AT LEAST SHOWER POTENTIAL THROUGH
THE OVERNIGHT. WITH THE LATEST HRRR SOLUTION SUPPORTING CONTINUED
ACTIVITY IN THE NORTH INTO THE EARLY MORNING...HAVE INCLUDED
LIKELY POPS ACROSS THE NORTH UNTIL 06Z AND CHANCE POPS ELSEWHERE
CONTINUING INTO TUESDAY. PRIMARILY SHOWERS POSSIBLE WITH ISOLATED
THUNDER. MADE ONLY MINOR TREND TWEAKS TO TEMPS AND DEWPOINTS.
PREVIOUS DISCUSSION FOLLOWS...
03
&&
.PREV DISCUSSION... /ISSUED 225 PM EDT MON AUG 6 2012/
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
WEAK TROPICAL LOW HAS WORKED ITS WAY INTO SOUTHEAST ALABAMA THIS
AFTERNOON AND IS PROGGED TO REMAIN IN THAT VICINITY THROUGH TONIGHT.
INDICATIONS ARE THE LOW WILL BEGIN LIFTING NORTHEAST ACROSS THE
FORECAST AREA BY TUESDAY AFTERNOON AND TUESDAY NIGHT. AS LONG AS THE
LOW REMAINS ACROSS THE SOUTHERN PORTIONS OF ALABAMA AND GEORGIA THE
WEAK COLD FRONT EXTENDING FROM THE MID-ATLANTIC COASTAL REGION TO
THE SOUTHERN PLAINS SHOULD BE HELD AT BAY. INSTABILITY REMAINS
MARGINAL THROUGH THE PERIOD AS THE VERTICAL TEMPERATURE PROFILES
REMAIN NEARLY MOIST ADIABATIC. BIGGEST THREAT FROM ANY CONVECTION IS
LIKELY TO BE LOCALLY HEAVY RAIN AS PRECIPITABLE WATER VALUES
CONTINUE TO HOVER AROUND THE 2 INCH RANGE. HARD TO TIME WHEN THE
BEST CHANCES FOR PRECIPITATION WILL BE THROUGH THE PERIOD AS
NORTHWEST UPPER FLOW IS LIKELY TO TRANSPORT A SERIES OF WEAK WAVES
INTO THE AREA. IN GENERAL I HAVE STUCK WITH A DIURNAL MAXIMUM
PATTERN TO THE PROBABILITY OF PRECIPITATION. EXTENSIVE CLOUD COVER
AND WIDESPREAD PRECIPITATION WILL KEEP TEMPERATURES AT OR BELOW
SEASONAL NORMALS THROUGH THE PERIOD.
20
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
TROPICAL MOISTURE REMAINS OVER THE REGION WEDNESDAY HOWEVER THE
WESTERLIES DIP DOWN A LITTLE INTO NORTH GA AND TRIES TO PUSH A WEAK
SURFACE TROUGH INTO THE NORTHERN PART OF THE CWA. THIS WILL AID IN
SHOWERS/THUNDERSTORMS...MAINLY DURING THE AFTERNOON WEDNESDAY ACROSS
THE CWA. NO OTHER CHANGES ARE PLANNED FOR THE REST OF THE LONG TERM.
PREVIOUS LONG TERM DISCUSSION FOLLOWS...
PREV LONG TERM DISCUSSION... /ISSUED 337 AM EDT MON AUG 6 2012/
/WEDNESDAY THROUGH SUNDAY/... OVERALL PATTERN REMAINS THE SAME
WITH BOTH GFS AND ECMWF IN GENERAL AGREEMENT. THE FORECAST AREA
PERSISTS IN A BROAD EASTERN TROUGH WITH A STALLED SURFACE BOUNDARY
WITH WEAK WAVES TRAVELING ALONG IT. WITH ABUNDANT TROPICAL
MOISTURE AVAILABLE...HAVE KEPT THE POPS IN AN AVERAGE 40 TO 50
PERCENT RANGE UNTIL THE END OF THE WEEK. MODELS STILL SHOWING SOME
DRYING AS AN UPPER CLOSED LOW DEEPENS OVER THE GREAT LAKES. THIS
MAY PUSH THE SURFACE BOUNDARY INTO SOUTH GEORGIA BEGINNING ON
SATURDAY. SO HAVE REDUCED THE POPS A BIT FOR SATURDAY AND SUNDAY.
WITH POTENTIAL FOR INCREASED CLOUD COVER...HIGHS IN THE MID 80S TO
LOW 90S LOOK REASONABLE FOR MUCH OF THE AREA.
17/41
&&
.AVIATION...
00Z UPDATE...
INITIAL VFR CIGS ARE EXPECTED TO LOWER TO MVFR AND IFR LEVELS
OVERNIGHT INTO TUESDAY. BKN CIGS NEAR 4 KFT SHOULD LOWER TO NEAR
1000-1500 FT AFTER 06Z AND 600-900 FT FROM 12-16Z...BEFORE
GRADUALLY RAISING BACK UP TO NEAR 2500 FT TUESDAY AFTERNOON.
SHOWER AND ISOLATED THUNDERSTORM POTENTIAL CONTINUES BEFORE ABOUT
06Z AND THEN RETURNS WITH MORE WIDESPREAD DEVELOPMENT DURING THE
DAYTIME HOURS ON TUESDAY. HAVE INCLUDED A PROB30 FOR -TSRA FOR
18-24Z TUESDAY WITH SHOWER DEVELOPMENT POSSIBLE BEFORE AND AFTER
THIS PERIOD. WINDS LOOK TO STAY MOSTLY SE UNDER 10KTS.
//ATL CONFIDENCE...00Z UPDATE...
MEDIUM CONFIDENCE ON TIMING OF PRECIPITATION AND TIMING OF CIGS.
HIGH CONFIDENCE ALL ELSE.
03
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 71 86 70 87 / 70 60 50 60
ATLANTA 72 86 73 87 / 70 60 50 60
BLAIRSVILLE 68 82 66 83 / 70 70 50 40
CARTERSVILLE 71 86 68 89 / 60 60 50 50
COLUMBUS 75 86 74 90 / 60 60 50 60
GAINESVILLE 71 86 71 86 / 70 60 50 60
MACON 73 86 73 88 / 60 60 50 60
ROME 70 86 69 91 / 60 60 50 40
PEACHTREE CITY 72 87 69 87 / 60 60 50 60
VIDALIA 75 87 74 88 / 50 70 50 60
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...20/03
LONG TERM....17/41
AVIATION...03
AREA FORECAST DISCUSSION
NWS LINCOLN IL
858 PM CDT MON AUG 6 2012
.DISCUSSION...
ISSUED 858 PM CDT MON AUG 6 2012
CENTRAL ILLINOIS WILL BE ON THE WESTERN EDGES OF DEPARTING SURFACE
HIGH PRESSURE OVERNIGHT. THE RIDGE AXIS WILL STILL GENERALLY
RESIDE OVER OUR COUNTIES UNTIL LATE TONIGHT...PROVIDING LIGHT AND
VARIABLE WINDS UNDER MOSTLY CLEAR SKIES.
ONE ITEM OF NOTE FOR LATE TONIGHT FOR OUR WESTERN COUNTIES MAY BE
A STORM COMPLEX THAT IS PROJECTED TO DEVELOP IN SW MINNESOTA AND
NW IOWA...ALONG AN INVERTED TROUGH EXTENDING FROM LOW PRESSURE IN
WESTERN NEBRASKA. THE HRRR MODEL INDICATES THEY MAY MOVE EAST-
SOUTHEAST ACROSS IOWA TOWARD SUNRISE. WHILE THE STORMS SHOULD
REMAIN WEST-NW OF OUR AREA...SOME CIRRUS CLOUDS FROM THAT COMPLEX
MAY COVER OUR WESTERN COUNTIES...HELPING TO KEEP THEIR LOW TEMPS
SLIGHTLY WARMER THAN THE REST OF OUR CWA. OUR GRIDS ALREADY
REFLECTED THAT POSSIBILITY.
AS FOR WINDS...THE RIDGE AXIS WILL BEGIN TO SLIDE JUST EAST OF
ILLINOIS BY 12Z TUESDAY...WHICH MAY TRANSLATE INTO WINDS
DEVELOPING A SOUTHWEST DIRECTION BY SUNRISE IN OUR WESTERN
COUNTIES. THAT RETURN FLOW MAY CARRY SLIGHT WARM ADVECTION AS
WELL...WHICH WOULD ALSO WORK TO KEEP THE WESTERN COUNTIES SLIGHTLY
WARMER.
THE FORECAST GRIDS WERE GENERALLY IN GOOD SHAPE...WITH ONLY SOME
MINOR ADJUSTMENTS TO THE SKY GRIDS TO ACCOUNT FOR LATE NIGHT
CIRRUS IN THE WEST. NO FORMAL ZONE UPDATE WILL BE NEEDED FOR THE
SMALL CHANGES. UPDATED GRIDS WILL BE AVAILABLE SHORTLY.
SHIMON
&&
.AVIATION...
ISSUED 643 PM CDT MON AUG 6 2012...FOR THE 00Z TAFS
UNSEASONABLY DRY AIR ASSOCIATED WITH HIGH PRESSURE WILL KEEP SKIES
CLEAR OVERNIGHT. SURFACE DEWPOINTS MIXED DOWN INTO THE UPPER 40S
IN SOME LOCATIONS THIS AFTERNOON. THAT WILL HELP KEEP ANY FOG AT
BAY AS OUR LOWS DIP INTO THE MID TO UPPER 50S TONIGHT.
WINDS WILL BE LIGHT AND VARIABLE AS THE SURFACE RIDGE AXIS SETTLES
DIRECTLY ACROSS CENTRAL IL FROM SW TO NE. WINDS WILL DEVELOP OUT
OF THE SOUTHWEST ON TUESDAY MORNING /15Z/ AS THE SURFACE HIGH AXIS
SHIFTS EAST OF ILLINOIS. WIND SPEEDS WILL REMAIN LESS THAN 10KT.
SHIMON
&&
.PREV DISCUSSION...
ISSUED 255 PM CDT MON AUG 6 2012
HIGH PRESSURE DOMINATING CENTRAL ILLINOIS WEATHER...AS WELL AS
MUCH OF THE MIDWEST THROUGHOUT THE FORECAST. UPPER RIDGING
CONTINUES OVER THE WESTERN HALF OF THE CONUS AND A FEW SYSTEMS
DIVE INTO THE GENERAL BROAD TROF OVER THE GREAT LAKES AND EASTERN
HALF OF THE COUNTRY. DEGREE OF INFLUENCE DEPENDING ON HOW DEEP THE
SYSTEMS DIG INTO THE TROF. SEEN THIS PATTERN SEVERAL TIMES OVER
THE SUMMER...WITH TEMPERATURES ON THE EDGE OF A MID LEVEL THERMAL
GRADIENT...A LITTLE MOVEMENT EITHER WAY OF THE WAVE PATTERN MAKES
A RATHER LARGE DIFFERENCE. THAT BEING SAID...STABILITY OF THE WAVE
PATTERN SEEMS TO BE IN AGREEMENT ACROSS OPERATIONAL MODELS.
HOWEVER...THE ISSUES COME INTO PLAY ON THE STRENGTH AND TIMING OF
THE WAVES FROM WED NIGHT INTO THU NIGHT...WITH THE NEXT CHANCE FOR
PRECIP.
SHORT TERM...TONIGHT AND TOMORROW...
QUIET WEATHER IN THE OVERNIGHT UNDER A RIDGE AXIS. CLEAR NIGHT AND
CALM WINDS EXPECTED. TOMORROW EXPECTED TO BE THE WARMEST OF THE
FORECAST...WITH LOW TO MID 90S ACROSS THE REGION AS THAT THERMAL
GRADIENT SLIPS A LITTLE FURTHER NORTH WITH THE WEAKER DIG INTO THE
EASTERN TROF. 19C TO 20C AT 850MB AND A RATHER DRY COLUMN WILL
KEEP THE TEMPS FAR ABOVE TODAY`S TEMPS. FLOW REMAINS RATHER
AMBIGUOUS THROUGH THE NEXT COUPLE OF DAYS WITH THE HIGH ANCHORING
THE WEATHER OVERALL.
LONG TERM...WEDNESDAY THROUGH SUNDAY...
NEXT SYSTEM ON APPROACH WED NIGHT. FORECAST MODELS DIFFERING A BIT
WITH TIMING AND STRENGTH OF THE INITIAL WAVE FOR MIDWEST. GFS
EARLY AND WET...BRINGING IN QPF ON TUES NIGHT. HOWEVER...BOTH
ECMWF AND NAM ARE SLIGHTLY SLOWER AND MORE CONSERVATIVE WITH
INITIAL PRECIP...KEEPING BACK UNTIL WED NIGHT. THINK SOME
SPRINKLES MAY BE ABLE TO DEVELOP WITH AGGRESSIVE ENOUGH OF A CU
FIELD ON WEDNESDAY...AND HAVE ADDED THAT GRID...BUT WOULD LIKE TO
DEFER THE FORECAST TO THE MORE CONSERVATIVE SOLUTION CONSIDERING
THE ONGOING DROUGHT AND THE TREND OF THE SUMMER IN GENERAL. POPS
THURSDAY AND INTO THURS NIGHT. FRI SHOULD BE MOSTLY DRY...BUT SOME
AFTERNOON POP UPS WILL LIKELY REMAIN POSSIBLE ON THE EASTERN
BORDER OF THE STATE WITH THE EXITING SYSTEM UNLESS IT CONTINUES TO
ACCELERATE A BIT. REMAINING FORECAST IS DRY...AS GFS IS OVERDOING
THE EXTENDED A BIT...AND THE ECMWF KEEPS THE
MIDWEST...PARTICULARLY THE BULLSEYE IN THE MIDDLE OF CENTRAL
ILLINOIS...DRY.
HJS
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1152 PM CDT SAT AUG 4 2012
.DISCUSSION...
ISSUED 900 PM CDT SAT AUG 4 2012
HI RES MODELS ARE STILL INDICATING WE SHOULD SEE SOME STORM
DEVELOPMENT ALONG THE COLD FRONT LATE THIS EVENING AND AFTER
MIDNIGHT. INSTABILITY PARAMS CONTINUE TO LOOK FAVORABLE FOR STORMS
AHEAD OF THE FRONT EVEN INTO CENTRAL AND SOUTHEAST IL. WE WILL
CONTINUE WITH AT LEAST HIGH CHANCE POPS...ALTHOUGH WE MAY PULL
BACK ON THE LIKELY POPS...OR DIMINISH THE COVERAGE OF LIKELY POPS.
CAN NOT RULE OUT A FEW STRONG STORMS WITH DAMAGING WINDS
POSSIBLE. STORMS IN EAST CENTRAL MISSOURI HAVE REACHED SEVERE
LEVELS AND THEY ARE APPROACHING SW ILLINOIS. THEIR PROGRESSION
WOULD MOSTLY LIKELY HAVE THEM AFFECTING OUR SOUTHEASTERN COUNTIES.
VARIABLE CLOUD COVER THE REST OF THE NIGHT...COUPLED WITH COLDER
AIR LAGGING WELL BEHIND THE COLD FRONT...SHOULD SET THE STAGE FOR
LOWS TO REMAIN IN THE UPPER 60S TO LOW 70S.
DRY AND NOT AS HOT FOR SUNDAY...WITH SUNDAY NIGHTS LOWS DIPPING
INTO THE 50S.
MAIN UPDATES WERE TO THE POP AND WEATHER GRIDS. UPDATED INFO WILL
BE AVAIL SHORTLY.
SHIMON
&&
.AVIATION...
ISSUED 1152 PM CDT SAT AUG 4 2012...FOR THE 06Z TAFS
IT APPEARS THAT THE COLD FRONT IS BECOMING ACTIVE AGAIN...BUT
ANY STORMS SHOULD MAINLY AFFECT AREAS EAST OF I-55. SO WE
INCLUDED VCTS AT SPI, DEC AND CMI FOR THE FIRST 2-3 HOURS OF THIS
TAF PERIOD. BMI APPEARS TO BE CLEAR OF ANY MORE THUNDERSTORMS.
WINDS HAVE BECOME NORTH AT ALL TERMINALS EXCEPT DEC AND CMI...WHO
ARE STILL AHEAD OF THE FRONT. THE SOUTHERLY WINDS AT DEC AND CMI
SHOULD REMAIN BELOW 10KT EXCEPT FOR IN THE VICINITY OF
THUNDERSTORMS...THEN WINDS WILL BECOME NNW BEHIND THE FRONT.
SOME LIGHT MVFR FOG MAY DEVELOP EVEN BEHIND THE FRONT AS SURFACE
DEWPOINTS REMAIN HIGH WELL BEHIND THE COLD FRONT. AS TEMPS DROP
AND SKIES CLEAR OUT...DEWPOINT DEPRESSIONS WILL DIP INTO THE 2-3F
RANGE.
NORTH WINDS TOMORROW WILL INCREASE INTO THE 12-14KT RANGE AS HIGH
PRESSURE BUILDS SOUTH INTO ILLINOIS.
SHIMON
&&
.PREV DISCUSSION...
ISSUED 341 PM CDT SAT AUG 4 2012
COLD FRONT HAS BEEN MOVING A BIT QUICKER TOWARD THE CWA...AND WAS
LOCATED FROM NEAR THE QUAD CITIES SOUTHWEST TO NEAR KANSAS CITY.
WELL-DEFINED MESOSCALE VORTEX FROM CONVECTION IN IOWA HELPED TO
DEVELOPED AN MCS WHICH HAS BEEN ROLLING ACROSS THE NORTHERN THIRD
OF ILLINOIS THIS AFTERNOON. SOME OF THE SOUTHERN FRINGES CONTINUE
TO PUSH ACROSS AREAS FROM CANTON EAST TO EL PASO AT MID AFTERNOON.
INSTABILITY OVER THE AREA PEAKED EARLY THIS AFTERNOON WITH CAPES
AROUND 4000 J/KG...BUT SPC MESO-ANALYSIS HAS BEEN SHOWING SOME
DECREASE IN CAPES AND INCREASE IN CAPPING ALOFT. HOWEVER...STILL
QUITE A BIT OF INSTABILITY AVAILABLE FROM SOUTHERN MISSOURI
NORTHEAST INTO EAST CENTRAL ILLINOIS. LATEST NAM AND HRRR SHOW
DEVELOPMENT OCCURRING IN THESE AREAS OVER THE NEXT COUPLE HOURS.
WILL MAINTAIN LIKELY POPS OVER A LARGE PART OF THE CWA THIS
EVENING...THEN LIMIT THEM TO 40-50 PERCENT AFTER MIDNIGHT ACROSS
THE EAST CENTRAL AND SOUTHEAST CWA. ANY LINGERING RAIN ACROSS THE
FAR SOUTHEAST WILL LIKELY BE ENDING BEFORE SUNRISE.
LITTLE CHANGE MADE TO THE REMAINDER OF THE FORECAST. BRIEF
COOL DOWN WILL BE NOTED EARLY THIS WEEK AS HIGH PRESSURE DRIFTS
EAST ACROSS THE AREA. A SLOW WARMING TREND WILL BRING TEMPERATURES
BACK TO NEAR 90 MUCH OF THE REMAINDER OF THE WEEK...WITH HOTTER
WEATHER KNOCKING ON THE DOOR AS WE REMAIN ON THE FRINGE OF THE
UPPER RIDGING ACROSS THE WESTERN HALF OF THE NATION. MAIN FEATURE
OF CONCERN IN THE LONG RANGE IS ON THURSDAY AND FRIDAY...WHEN A
PIECE OF ENERGY DROPS SOUTHEAST OUT OF THE CANADIAN PRAIRIES. GFS
AND ECMWF NOT TOO FAR APART WITH THE TRACK OF THIS SHORTWAVE OVER
THE GREAT LAKES...BUT THE GFS IS MORE AGGRESSIVE WITH BRINGING
RAIN CHANCES ALL THE WAY SOUTH ACROSS ILLINOIS. WILL KEEP SOME
SLIGHT CHANCES IN THE GRIDS THURSDAY AND THURSDAY NIGHT...BUT WILL
LEAN MORE TOWARD THE ECMWF WITH ITS ODDS OF DRY WEATHER.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
522 PM MDT MON AUG 6 2012
.UPDATE...
ISSUED AT 415 PM MDT MON AUG 6 2012
UPDATED TO INCLUDE THUNDERSTORM CHANCES IN THE WEST. CONVECTION
HAS INITIATED ALONG A SURFACE TROUGH IN NORTHEAST COLORADO. STORM
MOTIONS ARE ALMOST DUE SOUTH SO NOT SURE HOW FAR EAST THESE WILL
BE ABLE TO MOVE THIS EVENING. FURTHERMORE...DEW POINTS ARE QUITE
LOW. FOR THOSE REASONS...LIMITED POPS TO 30 IN THE FAR NORTHWEST
AND 20 ELSEWHERE.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 236 PM MDT MON AUG 6 2012
THROUGH TONIGHT...SHORTWAVE TROUGH WILL TRANSLATE SOUTHEASTWARD THE
NORTHERN PLAINS. STRONGEST FORCING FOR ASCENT WILL REMAIN NORTHEAST
OF THE FORECAST AREA. HOWEVER...WITH A SURFACE LOW DEVELOPING ACROSS
NORTHEAST COLORADO...DO EXPECT ISOLATED TO SCATTERED THUNDERSTORMS
TO DEVELOP ACROSS NORTHERN/NORTHEASTERN PORTIONS OF THE FORECAST
AREA AFTER 06Z. WILL ALSO NEED TO MONITOR A WEAK AREA OF SURFACE
CONVERGENCE JUST TO THE WEST OF THE FORECAST AREA WHERE A SHALLOW CU
FIELD CONTINUES TO DEVELOP. LATEST RUNS OF THE HRRR DEVELOP
CONVECTION IN THIS AREA WITH A GENERAL EASTWARD/SOUTHEASTWARD
MOVEMENT. NOT COMPLETELY SOLD ON THIS SOLUTION SO OPTING TO KEEP
POPS OUT OF THE FORECAST FOR NOW. WILL NEED TO MONITOR AND
REEVALUATE AS THE AFTERNOON GOES ON.
TUESDAY...SLIGHTLY STRONGER SHORTWAVE TROUGH WILL BEGIN TO IMPACT
THE REGION DURING THE DAY TUESDAY. WILL LIKELY SEE A LULL IN PRECIP
DURING THE MORNING HOURS IN THE WAKE OF THE DEPARTING OVERNIGHT
SYSTEM WITH PRECIP CHANCES INCREASING DURING THE AFTERNOON HOURS.
DEEP LAYER SHEAR WILL INCREASE TO AROUND 30-35 KTS DURING THE
AFTERNOON HOURS WHICH WILL HELP ORGANIZE THUNDERSTORM UPDRAFTS. ONE
LIMITING FACTOR WILL BE MINIMAL AVAILABLE INSTABILITY WITH SBCAPE
VALUES OF 500-1000 J/KG. POINT SOUNDINGS DO INDICATE AN INVERTED-V
STRUCTURE SO WOULD ANTICIPATE GUSTY OUTFLOW WINDS BEING THE PRIMARY
THREAT TOMORROW AFTERNOON/EVENING.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 236 PM MDT MON AUG 6 2012
TUESDAY NIGHT-THURSDAY...LARGE SCALE H5 RIDGE WILL AMPLIFY OVER THE
NORTHERN ROCKIES THROUGH THE PERIOD...WITH MAIN CONCERN BEING THE
CHANCE FOR LINGERING PRECIPITATION OVER PORTIONS OF THE CWA TUESDAY
NIGHT WITH PRECIPITATION CHANCES LOOKING TO BE VERY SMALL AFTER THAT
LARGE SCALE SUBSIDENCE OVERSPREADS THE AREA WITH DEEP LAYER FLOW
ALOFT OUT OF THE NORTH-NORTHWEST KEEPING ANY DEEP MOISTURE RETURN TO
THE AREA LIMITED. FOR TUESDAY NIGHT HOWEVER...DIV Q FIELDS SUGGEST LARGE
SCALE SUBSIDENCE WILL OVERSPREAD THE CWA AFTER 03Z...WHICH SHOULD
BEGIN TO DIMINISH PRECIPITATION POTENTIAL PRETTY QUICKLY OVERNIGHT.
WHILE THERE WILL BE LARGE SCALE SUBSIDENCE...THINK THERE WILL BE AT
LEAST A SHORT WINDOW FOR PRECIPITATION DURING THE EVENING
HOURS...MAINLY ALONG AND SFC TROUGH EXPECTED TO STRETCH FROM
FIRSTVIEW TO MCCOOK. WITH MIXED LAYER CINH VALUES FAIRLY HIGH AND
AFOREMENTIONED SUBSIDENCE CONFIDENCE IN PRECIPITATION FAIRLY LOW.
ALTHOUGH SREF AND GEFS HAVE FAIRLY HIGH PROBABILITIES (>75%) IN
EASTERN CWA...DO NOT THINK CONFIDENCE IS HIGH ENOUGH TO GO MORE THAN
20-40 PERCENT CHANCES THROUGH THE EVENING HOURS.
AS H5 RIDGE AMPLIFIES AND MUCH DRIER AIR WORKS INTO THE CWA...THINK
PRECIP CHANCES WILL REMAIN VERY LOW TO PRACTICALLY NOTHING THROUGH
THE REST OF THE PERIOD. SEEMS TO BE A FAIRLY LARGE SPREAD BETWEEN
MODELS WITH RESPECT TO HOW WARM THINGS WILL GET ACROSS THE AREA.
WHILE GFS IS MUCH COOLER THAN OTHER MODELS AND GIVEN THE OVERALL
FLOW PATTERN WOULD NOT BE UNHEARD OF FOR A COOLER AIR MASS TO BACK
INTO CWA. THAT BEING SAID...GFS HAS A FAIRLY WELL DOCUMENTED COLD
BIAS THIS SUMMER AND THINK OVERALL BIAS CORRECTED VALUES IN THE
MID/UPPER 90S LOOK REASONABLE. MUCH DRIER AIR IS EXPECTED TO MOVE
INTO THE AREA WEDNESDAY AFTERNOON ALLOWING RH`S TO APPROACH CRITICAL
VALUES. OVERALL DO NOT THINK CONDITIONS WILL BE LONG LASTING AND DO
NOT PLAN ON ISSUING ANY WATCHES AT THIS POINT AND THINK THE BIGGEST
IMPACT OF DRIER AIR MASS WILL BE TO ALLOW TEMPS TO BE RATHER COOL
GIVEN LIGHT WINDS/CLEAR SKIES AND DRY AIR.
IN THE EXTENDED (FRIDAY-NIGHT-MONDAY)...WHILE MEDIUM RANGE MODELS
START THE PERIOD IN REASONABLE AGREEMENT...DIFFERENCES EMERGE FAIRLY
QUICKLY IN THE PERIOD WITH RESPECT TO HANDLING OF SHORT WAVE TROUGH
MOVES AROUND TOP OF THE AMPLIFIED H5 RIDGE AND WHAT IMPACT...IF ANY
THIS TROUGH HAS ON LARGE SCALE RIDGE PATTERN. THESE DIFFERENCES DO
NOT LEAD TO A LOT OF CONFIDENCE IN FORECAST FROM SATURDAY ON...AND
PLAN ON KEEPING FORECAST NEAR CONSENSUS DATA FOR THE TIME BEING
UNTIL A BETTER FAVORED SOLUTION APPEARS...ALTHOUGH THINK WEIGHTING
BLENDS A BIT MORE TOWARDS THE ECWMF IS IN ORDER BASED ON THE GEFS
DATA. LATEST ECMWF HAS COME IN A BIT COOLER THAN PREVIOUS RUNS AND
GIVEN EASTERLY SFC FLOW AND STRONG HIGH AROUND BASE OF SFC HIGH
THINK A GENERAL COOLING TREND IS IN ORDER. WITH MOST NIGHTS NOT
REALLY BRINGING A CLEAR SIGNAL FOR WARM TEMPS (DENSE CLOUD
COVER...STRONG WINDS...ETC) HAVE WORKED THE 3-5 DEGREE COOLER BIAS
CORRECTED SOLUTIONS INTO OVERNIGHT LOW FORECASTS WHERE I COULD...TO
PICK UP OUR NORMALLY COLDEST SPOTS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 519 PM MDT MON AUG 6 2012
AN ISOLATED THUNDERSTORM MAY BRIEFLY IMPACT KMCK TONIGHT.
THUNDERSTORMS HAVE INITIATED NEAR A SURFACE TROUGH THAT EXTENDS
FROM NORTHEAST COLORADO TO CENTRAL NEBRASKA. STORM MOTIONS ARE DUE
SOUTH...SO IT IS POSSIBLE ONE OF THESE WILL BE NEAR THE TERMINAL.
HOWEVER...DUE TO LIMITED MOISTURE AND WEAK FORCING...COVERAGE WILL
BE LOW AND WARRANTS ONLY A VICINITY MENTION AT THIS TIME. BRIEF
GUSTY WINDS WILL BE POSSIBLE NEAR ANY THUNDERSTORM. LOW CHANCES
FOR THUNDERSTORMS WILL CONTINUE INTO TUESDAY FOR BOTH KMCK AND
KGLD...BUT UNCERTAINTY OVER COVERAGE PRECLUDES A MENTION IN THE
TAF ATTM.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...024
SHORT TERM...FOLTZ
LONG TERM...JRM
AVIATION...024
AREA FORECAST DISCUSSION...UPDATED
NWS PITTSBURGH PA
516 PM EDT SUN AUG 5 2012
.SYNOPSIS...
A COLD FRONT, CROSSING THE AREA THIS EVENING, WILL BRING A DAMP END
TO OUR WEEKEND. HIGH PRESSURE WILL BUILD OVERHEAD FOR THE
BEGINNING OF THE WORK WEEK. TEMPERATURES ARE PREDICTED TO REMAIN
AT SEASONAL LEVELS UNTIL THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
HAVE UPDATED THE POPS TO DEPICT BACK EDGE OF SHOWERS/STORMS. HAVE
ALSO MADE MINOR ADJUSTMENTS TO CLOUD COVER AND TEMPS.
PREVIOUS DISCUSSION...
RESIDUAL CLOUD COVER FROM THIS MORNING/EARLY AFTERNOON THUNDERSTORMS
HAS STABILIZED A GOOD PART OF THE AREA. HOWEVER...AS IS ALREADY
BEING DEPICTED OVER CENTRAL OHIO AND SOUTHEASTERN INDIANA...BREAKS
IN THE CLOUDS MAY ALLOW FOR ENOUGH HEATING AND DESTABILIZATION TO
FIRE ANOTHER LINE OF THUNDERSTORMS ALONG AND JUST AHEAD OF THE COLD
FRONT AS IT SWINGS ACROSS. SURFACE CAPE VALUES HAVE ALREADY REBOUNDED
TO NEAR 1000 J/KG OVER OHIO ACCORDING TO THE SPC MESOANALYSIS AND
THERE CONTINUES TO BE AMPLE LOW LEVEL MOISTURE WITH MUCH OF THE AREA
EXPERIENCING DEWPOINTS OF 70+. WHILE MOST OF THE BETTER UPPER LEVEL
SUPPORT AND SHEAR WILL REMAIN NORTH...WEAK BULK SHEAR OF 30KTS COULD
ALLOW FOR SOME STORMS TO SUPPORT THEMSELVES TO SEVERE LEVELS. THE
OTHER CONCERN WILL CONTINUE TO BE HEAVY RAINFALL. PWAT VALUES OVER
2 INCHES AND HIGH THETA-E VALUES WILL SUPPORT HEAVY DOWNPOURS. WHILE
THE FRONT SHOULD BE FAIRLY PROGRESSIVE...TRAINING STORMS OVER
AREAS THAT ALREADY RECEIVED ALMOST AN INCH OF RAINFALL COULD POSE
A PROBLEM. THIS WAS JUSTIFICATION TO KEEP LIKELY AND CATEGORICAL
POPS THROUGH THIS EVENING.
THE COLD FRONT IS EXPECTED TO CROSS THE REGION BY LATE
TONIGHT/MONDAY MORNING. MAY END UP BEING A LITTLE TOO SLOW WITH
THE REMOVAL OF POPS OVERNIGHT PER THE MOST RECENT HRRR MODEL OUTPUT
BUT WILL LEAVE AS IS FOR NOW.
HIGH PRESSURE WILL BUILD OVER THE REGION FOR MONDAY BRINGING DRIER
AIR AND TEMPERATURES CLOSER TO NORMAL. KEPT CLOSE TO LAMP/MAV
GUIDANCE WITH HIGHS AND LOWS TONIGHT AND MONDAY.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE WILL REMAIN THE MAIN STORY THROUGH MOST OF
WEDNESDAY. WITH STRONG SUBSIDENCE AND RADIATIVE
COOLING...TEMPERATURES OVERNIGHT MONDAY AND TUESDAY COULD BE BELOW
NORMAL AND INTO THE 50`S. THIS IS CLOSEST TO MAV GUIDANCE THROUGH
THE PERIOD.
MODELS ARE IN DISAGREEMENT ON THE APPROACH OF THE NEXT SYSTEM WITH
THE NAM BRINGING A FRONTAL BOUNDARY/SHORTWAVE ACROSS THE REGION
LATE WEDNESDAY. THIS IS QUICKER THAN THE GFS. AT THIS POINT...WILL
JUST HEDGE WITH SLIGHT CHANCE POPS WITH THE TIMING
INCONSISTENCIES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
NO MAJOR CHANGES TO EXTENDED FORECAST CONSIDERING FOCUS WAS ON
POSSIBLE SEVERE WEATHER FOR TODAY. MODELS STILL NOT SHOWING MUCH
AGREEMENT ON FRONTAL PASSAGE FOR END OF THE WORK WEEK. 12Z GFS
BRINGS FRONT THROUGH ON THURSDAY...00Z ECMWF BRINGS FRONT THROUGH ON
THURSDAY/FRIDAY...AND 00Z GEFS BRINGS FRONT THROUGH ON FRIDAY. AT
THIS POINT...HAVE STUCK CLOSE TO PREVIOUS FORECAST...WHICH BRINGS
FRONT THROUGH ON FRIDAY. TEMPERATURES WILL TURN COOLER FOR THE
WEEKEND...WITH HIGHS DROPPING INTO THE 70S. AN ISOLATED SHOWER
CANNOT BE RULED OUT OVER THE WEEKEND WITH RELATIVELY COOLER 850MB
AIR (10-12C) PASSING OVER A WARM LAKE ERIE (23-25C).
&&
.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
LOW CONFIDENCE FOR THIS TAF ISSUANCE...AS GUIDANCE SEEMS TO BE OF
NEARLY NO VALUE IN THE SHORT TERM. WIDESPREAD RAIN HAS MOVED EAST OF
THE AREA MORE QUICKLY THAN ANTICIPATED...AND AM STILL TRYING TO
DETERMINE WHAT WILL HAPPEN IN THE WAKE OF THE PRECIPITATION.
ALTHOUGH IMMEDIATELY AFTER RAIN COMES TO AN END SOME TERMINALS MAY
BRIEFLY GO VFR...UPSTREAM TRENDS INDICATE THAT MOST TERMINALS WILL
DROP BACK TO MVFR IN LOWER CEILINGS. WITH THE ACTUAL COLD FRONT
REMAINING TO THE WEST...ISOLATED/SCATTERED SHOWERS/STORMS CANNOT BE
RULED OUT DURING THE AFTERNOON HOURS. AFTER FRONT MOVES
THROUGH...WINDS WILL SHIFT TO THE WEST AND SOME CLEARING IS POSSIBLE
FOR THE EVENING HOURS.
WITH ABUNDANT SURFACE MOISTURE IN PLACE FROM TODAY`S RAINFALL, FOG
IS EXPECTED TO DEVELOP DURING THE PRE-DAWN HOURS ON MONDAY. HAVE
EXPANDED COVERAGE OF IFR FORECASTS CONSIDERING MOST LOCATIONS SAW AT
LEAST A QUARTER INCH OF RAIN. ALTHOUGH DUJ...LBE...AND MGW ARE THE
APPARENT EXCEPTIONS TO HEAVIER RAINFALL...IFR CONDITIONS CANNOT BE
RULED OUT IN THESE LOCATIONS EITHER. FOG WILL BREAK BY MID
MORNING...WITH LIGHT NORTHWEST WINDS EXPECTED.
OUTLOOK...MONDAY THROUGH FRIDAY...
VFR CONDITIONS WILL MOSTLY PREVAIL THROUGH WEDNESDAY AS HIGH
PRESSURE CROSSES THE OHIO VALLEY. LOW PRESSURE MOVING INTO THE
GREAT LAKES WILL RETURN THE CHANCE OF THUNDERSTORMS BY THE END OF
THE WEEK.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
303 PM EDT SUN AUG 5 2012
.SYNOPSIS...
A COLD FRONT CROSSING THE AREA THIS EVENING WILL BRING A DAMP END
TO OUR WEEKEND. HIGH PRESSURE WILL BUILD OVERHEAD FOR THE
BEGINNING OF THE WORK WEEK. TEMPERATURES ARE PREDICTED TO REMAIN
AT SEASONAL LEVELS UNTIL THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
RESIDUAL CLOUD COVER FROM THIS MORNING/EARLY AFTERNOON THUNDERSTORMS
HAS STABILIZED A GOOD PART OF THE AREA. HOWEVER...AS IS ALREADY
BEING DEPICTED OVER CENTRAL OHIO AND SOUTHEASTERN INDIANA...BREAKS
IN THE CLOUDS MAY ALLOW FOR ENOUGH HEATING AND DESTABILIZATION TO
FIRE ANOTHER LINE OF THUNDERSTORMS ALONG AND JUST AHEAD OF THE COLD
FRONT AS IT SWINGS ACROSS. SURFACE CAPE VALUES HAVE ALREADY REBOUNDED
TO NEAR 1000 J/KG OVER OHIO ACCORDING TO THE SPC MESOANALYSIS AND
THERE CONTINUES TO BE AMPLE LOW LEVEL MOISTURE WITH MUCH OF THE AREA
EXPERIENCING DEWPOINTS OF 70+. WHILE MOST OF THE BETTER UPPER LEVEL
SUPPORT AND SHEAR WILL REMAIN NORTH...WEAK BULK SHEAR OF 30KTS COULD
ALLOW FOR SOME STORMS TO SUPPORT THEMSELVES TO SEVERE LEVELS. THE
OTHER CONCERN WILL CONTINUE TO BE HEAVY RAINFALL. PWAT VALUES OVER
2 INCHES AND HIGH THETA-E VALUES WILL SUPPORT HEAVY DOWNPOURS. WHILE
THE FRONT SHOULD BE FAIRLY PROGRESSIVE...TRAINING STORMS OVER
AREAS THAT ALREADY RECEIVED ALMOST AN INCH OF RAINFALL COULD POSE
A PROBLEM. THIS WAS JUSTIFICATION TO KEEP LIKELY AND CATEGORICAL
POPS THROUGH THIS EVENING.
THE COLD FRONT IS EXPECTED TO CROSS THE REGION BY LATE
TONIGHT/MONDAY MORNING. MAY END UP BEING A LITTLE TOO SLOW WITH
THE REMOVAL OF POPS OVERNIGHT PER THE MOST RECENT HRRR MODEL OUTPUT
BUT WILL LEAVE AS IS FOR NOW.
HIGH PRESSURE WILL BUILD OVER THE REGION FOR MONDAY BRINGING DRIER
AIR AND TEMPERATURES CLOSER TO NORMAL. KEPT CLOSE TO LAMP/MAV
GUIDANCE WITH HIGHS AND LOWS TONIGHT AND MONDAY.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE WILL REMAIN THE MAIN STORY THROUGH MOST OF
WEDNESDAY. WITH STRONG SUBSIDENCE AND RADIATIVE
COOLING...TEMPERATURES OVERNIGHT MONDAY AND TUESDAY COULD BE BELOW
NORMAL AND INTO THE 50`S. THIS IS CLOSEST TO MAV GUIDANCE THROUGH
THE PERIOD.
MODELS ARE IN DISAGREEMENT ON THE APPROACH OF THE NEXT SYSTEM WITH
THE NAM BRINGING A FRONTAL BOUNDARY/SHORTWAVE ACROSS THE REGION
LATE WEDNESDAY. THIS IS QUICKER THAN THE GFS. AT THIS POINT...WILL
JUST HEDGE WITH SLIGHT CHANCE POPS WITH THE TIMING
INCONSISTENCIES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
NO MAJOR CHANGES TO EXTENDED FORECAST CONSIDERING FOCUS WAS ON
POSSIBLE SEVERE WEATHER FOR TODAY. MODELS STILL NOT SHOWING MUCH
AGREEMENT ON FRONTAL PASSAGE FOR END OF THE WORK WEEK. 12Z GFS
BRINGS FRONT THROUGH ON THURSDAY...00Z ECMWF BRINGS FRONT THROUGH ON
THURSDAY/FRIDAY...AND 00Z GEFS BRINGS FRONT THROUGH ON FRIDAY. AT
THIS POINT...HAVE STUCK CLOSE TO PREVIOUS FORECAST...WHICH BRINGS
FRONT THROUGH ON FRIDAY. TEMPERATURES WILL TURN COOLER FOR THE
WEEKEND...WITH HIGHS DROPPING INTO THE 70S. AN ISOLATED SHOWER
CANNOT BE RULED OUT OVER THE WEEKEND WITH RELATIVELY COOLER 850MB
AIR (10-12C) PASSING OVER A WARM LAKE ERIE (23-25C).
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
LOW CONFIDENCE FOR THIS TAF ISSUANCE...AS GUIDANCE SEEMS TO BE OF
NEARLY NO VALUE IN THE SHORT TERM. WIDESPREAD RAIN HAS MOVED EAST OF
THE AREA MORE QUICKLY THAN ANTICIPATED...AND AM STILL TRYING TO
DETERMINE WHAT WILL HAPPEN IN THE WAKE OF THE PRECIPITATION.
ALTHOUGH IMMEDIATELY AFTER RAIN COMES TO AN END SOME TERMINALS MAY
BRIEFLY GO VFR...UPSTREAM TRENDS INDICATE THAT MOST TERMINALS WILL
DROP BACK TO MVFR IN LOWER CEILINGS. WITH THE ACTUAL COLD FRONT
REMAINING TO THE WEST...ISOLATED/SCATTERED SHOWERS/STORMS CANNOT BE
RULED OUT DURING THE AFTERNOON HOURS. AFTER FRONT MOVES
THROUGH...WINDS WILL SHIFT TO THE WEST AND SOME CLEARING IS POSSIBLE
FOR THE EVENING HOURS.
WITH ABUNDANT SURFACE MOISTURE IN PLACE FROM TODAY`S RAINFALL, FOG
IS EXPECTED TO DEVELOP DURING THE PRE-DAWN HOURS ON MONDAY. HAVE
EXPANDED COVERAGE OF IFR FORECASTS CONSIDERING MOST LOCATIONS SAW AT
LEAST A QUARTER INCH OF RAIN. ALTHOUGH DUJ...LBE...AND MGW ARE THE
APPARENT EXCEPTIONS TO HEAVIER RAINFALL...IFR CONDITIONS CANNOT BE
RULED OUT IN THESE LOCATIONS EITHER. FOG WILL BREAK BY MID
MORNING...WITH LIGHT NORTHWEST WINDS EXPECTED.
OUTLOOK...MONDAY THROUGH FRIDAY...
VFR CONDITIONS WILL MOSTLY PREVAIL THROUGH WEDNESDAY AS HIGH
PRESSURE CROSSES THE OHIO VALLEY. LOW PRESSURE MOVING INTO THE
GREAT LAKES WILL RETURN THE CHANCE OF THUNDERSTORMS BY THE END OF
THE WEEK.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
432 AM EDT SUN AUG 5 2012
.SHORT TERM...(TONIGHT)
ISSUED AT 432 PM EDT SAT AUG 4 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A VIGOROUS LOOKING
SHORTWAVE TROF ACROSS THE ERN DAKOTAS/MN. AT THE SFC...ASSOCIATED
COLD FRONT IS SLICING THRU WRN LAKE SUPERIOR/WRN UPPER MI AND NW
WI. DESPITE VIGOROUS LOOK OF SHORTWAVE...CONVECTION HAS BEEN KEPT IN
CHECK BY ABUNDANT CLOUD COVER THAT HAS PERSISTED THRU THE DAY ACROSS
GOOD PORTIONS OF UPPER MI AND NRN WI. LATEST SPC MESOANALYSIS SHOWS
MLCAPE OF MOSTLY UNDER 500J/KG ACROSS THE FCST AREA. HIGHEST
VALUES...A LITTLE OVER 500J/KG...ARE OVER THE E WHERE THERE HAS BEEN
MORE SUNSHINE WITH SFC DWPTS AROUND 70F. IF MORE INSTABILITY HAD
DEVELOPED...A FAIRLY SIGNIFICANT SVR WEATHER OUTBREAK WOULD PROBABLY
BE GETTING UNDERWAY ACROSS THE FCST AREA AS DEEP LAYER SHEAR IS
STEADILY INCREASING TOWARD THE 40-50KT RANGE DUE TO MIDLEVEL SPEED
MAX APPROACHING THE AREA.
MAIN SHOW TONIGHT WILL BE S OF THE AREA WITH CONVECTIVELY ENHANCED
SHORTWAVE TRACKING TOWARD SRN WI/NRN IL/LWR MI. THE ONGOING
ASSOCIATED CLUSTER OF STRONG/SVR STORMS WILL PASS S OF THE AREA.
THAT SAID...OVER THE NEXT FEW HRS...SHRA/TSRA SHOULD TEND TO EXPAND
NE ACROSS ROUGHLY THE E HALF OF THE FCST AREA AS HEIGHT FALLS AND
RIGHT ENTRANCE OF UPPER JET STREAK WORK TO INCREASE UPWARD MOTION.
THERE IS STILL THE POTENTIAL OF ISOLD SVR STORMS...BUT WITH CLOUD
COVER NOW INCREASING EVEN OVER THE ERN FCST AREA TO PREVENT
INSTABILITY FROM BUILDING HIGHER...IT APPEARS RISK OF SVR STORMS IS
DIMINISHING. WILL KEEP SLIGHT RISK OF SVR WORDING IN HAZARDOUS WX
OUTLOOK FOR THE NEXT FEW HRS OR SO.
AFTER ANY SHRA/TSRA WITH COLD FRONT DEPART...ATTENTION TURNS TO VORT
MAX AND SECONDARY COLD FRONT THAT WILL SWING INTO THE AREA LATE
TONIGHT. THERE HAS BEEN FAIRLY SOLID COVERAGE OF SHRA AND EVEN SCT
TSRA ACROSS SE MANITOBA INTO ADJACENT NRN ONTARIO WITH TROF AXIS
THOUGH PCPN HAS TAKEN ON MORE OF A DIURNAL SCT COVERAGE THIS AFTN.
AS TROF AXIS/VORT MAX DROP INTO THE AREA...THERE SHOULD BE DECENT
SHRA COVERAGE LATE TONIGHT INTO SUN MORNING...ESPECIALLY SINCE CAA
DROPS 850MB TEMPS TO AROUND 6C BY 12Z SUN. WITH WATER TEMPS AROUND
20C ON LAKE SUPERIOR...THE OVERWATER INSTABILITY WILL BE MORE THAN
SUFFICIENT FOR LAKE ENHANCEMENT UNDER CYCLONIC FLOW WITH ARRIVAL OF
VORT MAX. THUS...EXPECT SCT/NMRS SHRA TO DEVELOP LATE TONIGHT OVER
THE NW HALF OF UPPER MI. AS ALWAYS...UPSLOPE NW WINDS WILL LEAD TO
MOST NMRS COVERAGE OVER THE HIGHER TERRAIN DOWNWIND OF THE LAKE.
.LONG TERM...(SUNDAY THROUGH SATURDAY)
ISSUED AT 432 PM EDT SAT AUG 4 2012
GOOD AGREEMENT FM THE GFS/ECMWF/GEM-NHEM WITH OVERALL UPPER AIR
PATTERN THROUGH THIS WEEK. PATTERN STARTS OFF WITH DEEP TROUGH OVER
THE UPPER GREAT LAKES AND BROAD WEST-TO-EAST RIDGE ACROSS THE
SOUTHERN TIER OF THE CONUS. BY MIDWEEK...RIDGE BECOMES MORE
AMPLIFIED OVER INTERMOUNTAIN WEST INTO WESTERN CANADA WHILE
TROUGHING REMAINS IN PLACE OVER EASTERN CANADA AND THE GREAT LAKES
AND NORTHEAST CONUS.
WEATHER WILL STAY ON THE ACTIVE SIDE AS MULTIPLE SYSTEMS IMPACT THE
UPPER GREAT LAKES. FIRST WILL BE RIGHT AT BEGINNING OF LONG TERM ON
SUNDAY. ANOTHER WEAKER COLD FRONT COMES THROUGH AREA ON TUESDAY.
MUCH STRONGER LOW PRESSURE SYSTEM FCST TO PUSH ACROSS GREAT LAKES
LATER THURSDAY INTO FRIDAY. IT IS THIS SYSTEM THAT SHOWS THE MOST
POTENTIAL TO PRODUCE NOTEABLE PRECIPITATION AMOUNTS IN THE LONG TERM.
SINCE THE LARGE TROUGH IS CLOSE BY AND RIDING REMAINS WELL TO THE
WEST...EXPECT TEMPERATURES TO GENERALLY BE WITHIN A FEW DEGREES OF
NORMAL. ONLY WARM EXCEPTION WILL BE ON MONDAY AHEAD OF ANOTHER COLD
FRONT. SOME COOL PERIODS ARE EXPECTED AS WELL. COOLEST OF THE BUNCH
LIKELY WILL BE ON SUNDAY...BUT SIMILAR COOLER TEMPERATURES MAY OCCUR
AGAIN ON FRIDAY ON IN WAKE OF LOW PRESSURE SYSTEM MOVING THROUGH THE
GREAT LAKES.
A VERY CHAGEABLE WEATHER DAY IS IN STORE FOR SUNDAY. COLD FRONT
THROUGH UPR MICHIGAN BY DAYBREAK WHILE SFC LOW PUSHES ACROSS JAMES
BAY. COOL AND MOIST CYCLONIC FLOW SFC THROUGH H7 AFFECTS MOST CWA
THROUGH LATE MORNING THEN HEIGHTS RISE QUICKLY WHILE EDGE OF SFC
HIGH BUILDS IN MID-LATE AFTN. MOIST CYCLONIC FLOW AND THERMAL TROUGH
WITH H85 TEMPS AS LOW AS +5C IN ADDITION TO A SHARP SECONDARY WAVE
DROPPING THROUGH MEAN TROUGH SHOULD COMBINE TO BRING A PERIOD OF
SHOWERS TO PORTIONS OF CWA THROUGH THE MORNING. WARM LK SUPERIOR
TEMPS NEAR +20C ALSO ALLOW LAKE EFFECT PROCESSES TO ENHANCE PCPN
AS DELTA T/S ARE AROUND 14-15C/LAKE INDUCED CAPES UP TO 250 J/KG.
INCREASED POPS OVER UPSLOPE AREAS FAVORED BY NW BLYR WINDS. HIGHEST
POPS IN THE MORNING...THEN RAPIDLY DROPPING OFF IN THE AFTN AS AREA
QUICKLY RESIDES IN SUBSIDENCE REGION OF THE STRONG SHORTWAVE. SKIES
PROBABLY CLEAR QUICKLY IN THE AFTN DUE TO SUBSIDENCE AND DRY AIR.
TEMPS KIND OF TRICKY...BUT FOLLOWED TREND CLOSER TO GEM-REGIONAL
SHOWING TEMPS STUCK IN THE MID 50S-LOW 60S INTO EARLY AFTN...THEN
RISING TOWARD 70 DEGREES LATER IN THE DAY WITH INCREASING SUNSHINE.
GUSTY WINDS OTHER FACTOR ON SUNDAY AS DEEP MIXING EXPECTED THROUGH
EARLY AFTN BEFORE H85 WARM ADVECTION INCREASES STABILITY. MIXED
LAYER WINDS THROUGH 16Z 35-40KT AND EXPECT GOOD PORTION OF THESE TO
MIX TO SFC. STRONGEST WINDS NEAR EXPOSED LK SUPERIOR SHORE OF CNTRL
AND EAST. EXPECT WINDS TO DIMINISH BY LATE DAY.
HIGH PRESSURE AXIS REMAINS JUST SOUTH OF AREA SUNDAY NIGHT BUT WINDS
BECOME LIGHT ENOUGH/PWAT LOW ENOUGH TO SEE SOME RADIATIONAL COOLING
TAKE PLACE. LOWEST MINS SEEM LIKELY IN THE INTERIOR CNTRL AND EAST
WHERE COLD SPOTS MAY DROP INTO LOWER 40S.
MUCH DIFFERENT DAY ON MONDAY COMPARED TO COOLER/WINDY DAY ON SUNDAY.
HIGH PRESSURE SLIDES EAST AND A WEAK COLD FRONT IS FCST TO DROP INTO
UPR LAKES MONDAY NIGHT. NOT A LOT OF CLOUD COVER AHEAD OF FRONT
THOUGH OTHER THAN ON THE KEWEENAW IN THE LATER AFTN. WITH H85 TEMPS
15C-16C EXPECT HIGHS TO REACH WELL INTO THE 80S AWAY FM LK MICHIGAN
SHORE. AS UPR JET SLIDES ACROSS ONTARIO MONDAY NIGHT AND MID-LEVEL
FGEN INCREASES OVR LK SUPERIOR...EXPECT BAND OF SHRA/TSRA TO DEVELOP
ALONG SFC FRONT. FRONT SLIDES THROUGH CWA ON MONDAY NIGHT...WITH
BETTER CHANCES OF SHRA/TSRA TIED INTO THE MID-LEVEL FORCING.
SOUNDINGS SHOW DRY AIR LINGERING BLO H85-H7 DUE TO LIMITED MOISTURE
ADVECTION FM THE GULF INTO THIS SYSTEM. SO...COVERAGE OF PRECIP WILL
BE SPOTTY WITH THE FRONT. HIGH PRESSURE BUILDS BACK IN FOR TUESDAY
WITH TEMPS IN THE 70S NORTH AND NEARING 80 DEGREES OVR THE SOUTH AND
NEAR LK MICHIGAN.
EXTENDED...MAIN CHANCES FOR SHRA/TSRA COME IN LATER WEDNESDAY NIGHT
INTO THURSDAY AS ANOTHER UPPER LOW AND SFC LOW MOVE ACROSS THE UPR
LAKES. CYCLONIC FLOW LINGERING IN THE WAKE OF THE SFC LOW COULD
KEEP SOME SHRA GOING OVR THE AREA INTO FRIDAY...KIND OF SIMILAR TO
WHAT IS EXPECTED ON SUNDAY. WITH EXPECTED CLOUDS/PCPN...TRIMMED
TEMPS THURSDAY AND FRIDAY CLOSER TO LK SUPERIOR WHERE ONSHORE
NORTHEAST FLOW SHOULD RESULT IN COOLER CONDITIONS. INCREASED WINDS
OVR LK SUPERIOR SOME COMPARED TO GUIDANCE CONSENSUS BUT MAY NEED TO
INCREASE FURTHER WITH LATER FCSTS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 431 AM EDT SUN AUG 5 2012
FIRST COLD FRONT HAS PASSED THROUGH ALL THREE TAF SITES WITH SECOND
COLD FRONT PUSHING INTO KIWD. A SURGE OF COLDER AIR AT 850 MB
ASSOCIATED WITH THIS SECOND COLD FRONT WILL BRING GUSTY WINDS TO ALL
THREE SITES AND IFR CIGS AND ASSOCIATED LAKE EFFECT SHOWERS TO KIWD
AND KCMX. CIGS TO APPROACH IFR AT KSAW BUT WITH SLIGHT DOWNSLOPE TO
WIND DIRECTION THEY SHOULD STAY JUST ABOVE IFR. FRONT SHOULD MOVE
THROUGH KCMX BY 7Z AND REACH KSAW AROUND 9Z. AS THE GRADIENT
TIGHTENS UP...EXPECT TO SEE GUSTY NW WINDS TO 25-30KT.
PRESSURE GRADIENT WILL RELAX RATHER QUICKLY THIS AFTERNOON AS THE
LOW MOVES AWAY FROM THE REGION. SKIES WILL CLEAR RATHER QUICKLY AS
DECENT SUBSIDENCE ARRIVES WITH SKIES BECOMING VFR AROUND 16Z AT KIWD
AND KCMX SOON AFTER...WITH CLEARING REACHING KSAW AROUND 18Z.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 432 PM EDT SAT AUG 4 2012
COLD FRONT PASSES ACROSS LK SUPERIOR THIS EVENING. PERIOD OF STRONG
WINDS AND HIGH WAVES /LIKELY OVR 10 FEET/ EXPECTED LATE TONIGHT
THROUGH MUCH OF SUNDAY AFTERNOON. EXPECT 25-30 KT WINDS FM THE
NORTHWEST DURING ON SUNDAY WITH FREQUENT GALE GUSTS 35-40 KTS. A
GALE WATCH HAS BEEN POSTED FOR THE EAST HALF OF LK SUPERIOR MOST
OF SUNDAY. WINDS DIMINISH SUNDAY NIGHT...BUT THEN INCREASE FM THE
SOUTHWEST ON MONDAY AHEAD OF A COLD FRONT THAT SLIDES THROUGH ON
MONDAY NIGHT. IN WAKE OF THE FRONT...EXPECT WINDS 20 KTS OR LESS
TUESDAY INTO WEDNESDAY AS HIGH PRESSURE MOVES ACROSS THE REGION.
WINDS MAY END UP STRONGER THAN FCST FOR LATE THIS WEEK AS DETAILS
ARE SORTED OUT REGARDING ANOTHER LOW PRESSURE SYSTEM MOVING THROUGH
THE UPPER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 8 AM THIS MORNING TO 8 PM EDT THIS EVENING FOR
LSZ251-267.
GALE WARNING UNTIL 6 PM EDT THIS EVENING FOR LSZ249-250-266.
GALE WARNING UNTIL 2 PM EDT THIS AFTERNOON FOR LSZ244-245-264-
265.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...RJT
MARINE...JLA
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
615 PM CDT MON AUG 6 2012
.UPDATE...FOR 00Z AVIATION DISCUSSION BELOW...
&&
.DISCUSSION.../ISSUED 414 PM CDT MON AUG 6 2012/
OVERVIEW...ABOVE NORMAL TEMPS EXPECTED TOMORROW BEFORE SHOWERS AND
STORMS ON WEDNESDAY KICK START A COOLING TREND THAT WILL LAST THROUGH
THE WEEKEND. RAIN CHANCES ON THURSDAY AND FRIDAY ARE BASED ON TWO
INDEPENDENT FEATURES. INCREASED POPS DURING THIS TIME FRAME.
CERTAINLY A NON ZERO CHANCE OF PRECIP TONIGHT IN WESTERN WI AND IN
FAR SOUTHERN MN. A COUPLE RUNS OF THE HRRR AND THE RAP BOTH
HIGHLIGHT THESE AREAS WITH SHOWERS LATE THIS EVENING. SEEING THE
EFFECTS OF THE COLD FRONT STRETCHED OUT ACROSS NORTHERN MM.
GETTING NEAR SURFACE CONVERGENCE SHOWING UP IN THE MESO ANALYSIS
BUT ALSO PRETTY OBVIOUS JUST BASED ON THE LOW LEVEL FLOW. NICE
BAND OF CUMULUS AND EVENED EMBEDDED SHOWERS VISIBLE THIS
AFTERNOON. SECONDLY...SUBTLE SHORTWAVE ENERGY IN THE EASTERN
DAKOTAS ALSO DROPPING SOUTH THIS AFTERNOON. NOT MUCH BEING
REFLECTED IN THE SHORT TERM HEIGHT/VORTICITY FIELDS...BUT
DEFINITELY SOMETHING APPARENT ON THE WATER VAPOR. IN
GENERALLY...TRIMMED THE POPS BACK TONIGHT. POP VALUES WERE ALREADY
LOW...IN THE 20-30%...BY LIMITED THE AREAL EXTEND OF THE POPS
COMPARED TO THE PREVIOUS FORECAST. THINK A VAST MAJORITY OF THE
FORECAST AREA REMAINS DRY EVEN WITH THE WEAK FRONTAL PASSAGE.
WONDERING IF THE HIGH DEWPOINT BIAS OFF THE RAP IS PLAYING INTO
THE EXTRA PRECIP TONIGHT.
REALLY CAN NOT SEE HOW MUCH DIFFERENT TOMORROW WILL BE COMPARED
TO TODAY IN TERMS OF TEMPERATURES. IT MIGHT BE A DEGREE OR TWO
COOLER THAN TODAY...BUT 70-80% OF THE GUIDANCE HAS FORECAST 2M
TEMPS AND 850MB TEMPS VERY SIMILAR TO WHAT WAS SEEN TODAY. STILL
LOOKS GOOD FOR AT LEAST SCATTERED SHOWERS AND THUNDERSTORMS ON
WEDNESDAY WITH SHORTWAVE ROTATING AROUND THE RIDGE OVER THE NEXT
36-48HRS. SHEAR IS MARGINAL WITH RELATIVELY WEAK MID LEVEL
FLOW...BUT FORCING AND INSTABILITY SHOULD NOT BE A PROBLEM...SO
LIKELY POPS ARE NOT A STRETCH AT THIS POINT. WE BLEED THE POPS
INTO THURSDAY DUE TO THE UPPER LOW DROPPING SOUTH OUT OF THE
INTERIOR OF CANADA...NOW IN NORTH CENTRAL CANADA BETWEEN 70-75
NORTH. THIS SYSTEM HAS PROBABLY TRENDED A LITTLE BIT SLOWER AND
STRONGER WITH TIME OVER THE LAST COUPLE DAYS. THERE IS NOT MUCH
RECOVERY IN TERMS OF INSTABILITY...BUT COOL TEMPS ALOFT SUGGESTS
SHOWERY ACTIVITY WITH EMBEDDED THUNDER. COOLED TEMPS ON
THURSDAY...MIGHT BE HARD TO GET MUCH ABOVE 75 IN SOME LOCATIONS IN
CENTRAL MN AND WI WITH CLOUD COVER AND SHOWERS.
&&
.AVIATION.../00Z TAF ISSUANCE/
COLD FRONT WILL PASS ACROSS THE AREA TONIGHT...ALTHOUGH THE
PRIMARY RESULT AT THE TAF SITES WILL BE A SHIFT IN THE WINDS /IN
THE ABSENCE OF MOISTURE AND LIFT ADEQUATE FOR PRECIPITATION/. IF
ANY CONVECTION WAS TO DEVELOP THIS FAR SOUTH OF THE MAIN SHORTWAVE
OVER THE GREAT LAKES...IT WOULD AFFECT WI/MN AREAS TO THE EAST AND
SOUTH OF THE TAF SITES. THEREFORE...NO MENTION OF SHRA/TS HAS BEEN
INCLUDED IN THE TAF. COULD SEE SOME LIGHT FOG DEVELOPMENT IN WEST
CENTRAL WI WHERE WINDS GO CALM FOR AWHILE OVERNIGHT AND COMBINE
WITH A PERIOD OF MOSTLY CLEAR SKIES AND DEWPOINTS IN THE LOWER
60S. HAVE INCLUDE MINOR VSBY REDUCTIONS /3-6SM/ AT KEAU AND KRNH
BETWEEN 08Z AND 12Z. WIND DIRECTIONS MAY BE A BIT SPORADIC IN
NATURE...BUT SHOULD GENERALLY REDUCE TO BELOW 5 KTS AT THE START
OF THE PERIOD...AND FOLLOW A GRADUAL SOUTHEAST-SOUTHWEST-
NORTHWEST-NORTHEAST EVOLUTION DURING THE PERIOD AS THE FRONT
APPROACHES AND PASSES.
KMSP...WINDS MAY BACK TO 140-160 DEGREES AT THE START OF THE
PERIOD AT THEY COME DOWN BELOW 05 KTS...BUT WILL VEER AROUND TO
THE SOUTHWEST AND INCREASE TO AROUND 6 KTS BY 05Z. SHIFT TO THE
NORTHWEST WITH THE FRONTAL PASSAGE IS EXPECTED TO OCCUR BETWEEN
08Z AND 09Z. WINDS WILL EVENTUALLY SHIFT TO NORTHERLY AFTER
15Z...AND THEN NORTHEASTERLY ON TUESDAY AFTERNOON. HAVE MAINTAINED
A PRECIP-FREE TAF...AS ANY SHRA/TS DEVELOPMENT IS STILL EXPECTED
TO BE DISPLACED EAST/SOUTH OF MSP.
/OUTLOOK/
.WEDNESDAY...VFR WITH MVFR/TSRA POSSIBLE. WINDS SE AT 5-10 KTS.
.THURSDAY...MVFR CLOUDS AND SHRA DURING THE DAY...BECOMING VFR
OVERNIGHT. WINDS N AT 10G15 KTS.
.FRIDAY...VFR. WINDS E 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
LS/CLF
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1158 AM CDT SUN AUG 5 2012
.UPDATE...
ISSUED AT 1059 AM CDT SUN AUG 5 2012
QUICK UPDATE MAINLY FOR CLOUDS AND POPS. WITH THE CDFNT SLOWLY
SINKING SWWD...CLOUDS SHUD GRADUALLY CLEAR OUT N TO S. LATEST MDLS
SUGGEST SHRA/TSRA REDEVELOPING ALONG OR JUST S OF THE CWA. HAVE
KEPT POPS FOR MID TO LATE THIS AFTERNOON TO ACCOUNT FOR THIS
REDEVELOPMENT...BUT WITH THE BEST CHANCES FURTHER S...WILL KEEP
ONLY SLIGHT CHANCES GOING FOR NOW. WILL CONTINUE TO MONITOR AND
UPDATE AS NEEDED. THE REMAINDER OF THE FORECAST APPEARS TO BE ON
TRACK ATTM.
TILLY
&&
.SHORT TERM...
ISSUED AT 248 AM CDT SUN AUG 5 2012
(TODAY AND TONIGHT)
FOCUS INITIALLY WILL BE ON EXITING THUNDERSTORMS. LATEST RUNS OF
THE RAP SEEM TO BE IN LINE WITH CURRENT EXTRAPOLATION THAT SURFACE
FRONT WILL BE RIGHT ALONG THE SOUTHERN BORDER OF THE CWA AT 12Z.
AXIS OF SHORTWAVE TROUGH CURRENTLY ALONG THE KS/MO BORDER WILL BE
OVER SOUTHEASTERN MO WITH SOME LINGER 925-850 ALONG AND JUST NORTH
OF THE SFC FRONT. HAVE ISOLATED/SCATTERED THUNDERSTORMS SLOWLY
PUSHING SOUTH OF THE CWA BETWEEN 12-18Z BEFORE SUBSIDENCE SETS IN
BEHIND THE SHORTWAVE. CLOUDS WILL ALSO DECREASE THROUGH MIDDAY AS
LOW-MID LEVEL MOISTURE AND CONVECTIVE DEBRIS MOVES OUT OF THE AREA.
STAYED WITH THE BETTER VERIFYING NAM MOS HIGHS TODAY...PARTICULARLY
WHERE THERE SHOULD BE THE MOST SUN. SKIES WILL BE CLEAR TONIGHT AND
WINDS SHOULD TURN LIGHT EASTERLY BY MORNING AS SURFACE HIGH CENTER
PASSES THROUGH NORTHERN MO/CENTRAL IL. CAN`T RULE OUT SOME FOG
DEVELOPING IN AREAS THAT HAD THE HEAVIEST RAINFALL THE PAST 24 HOURS
LATE TONIGHT/EARLY MONDAY.
BRITT
&&
.LONG TERM...
ISSUED AT 248 AM CDT SUN AUG 5 2012
(MONDAY THROUGH SATURDAY)
DRY WEATHER WILL BE THE RULE MONDAY AND TUESDAY AS LOW LEVEL
MOISTURE WILL BE CUT OFF BY FRONT MOVING THROUGH TODAY AND AREA WILL
BE UNDER MAINLY SUBSIDENCE IN NORTHWESTERLY FLOW ALOFT. NAM/GFS
BOTH SHOW A TROUGH MOVING ACROSS THE MIDWEST ON TUESDAY...BUT THE
BEST ASCENT WILL STAY TO THE NORTH OF THE AREA AS IT BEGINS TO SHEAR
OUT. STAYED CLOSER TO THE NAM MOS FOR HIGHS AS FORECAST SOUNDINGS
ARE SHOWING MIXING UP TO 800MB ON MONDAY AND 700MB ON TUESDAY.
LOWER 90S SEEM REASONABLE ON MONDAY WITH 850MB TEMPS NEAR 20C...AS
DO MIDDLE TO POSSIBLY UPPER 90S ON TUESDAY WITH 20-24C 850MB TEMPS.
DOES LOOK LIKE DEWPOINTS WILL STAY IN THE 50S DURING THE PERIOD
WHICH SHOULD KEEP HEAT INDEX READINGS AT OR BELOW THE AMBIENT
TEMPERATURES.
THE GFS IS SHOWING A DEEPER TROUGH DIGGING IN OVER THE MISSISSIPPI
VALLEY ON THURSDAY THAN IT DID PREVIOUSLY. ECMWF/CANADIAN GEM SHOW
A LESS AMPLIFIED AND SLOWER SOLUTION...SO GOING SLIGHT CHANCES FOR
THUNDERSTORMS SEEM THE BEST ROUTE. THEN GFS IS SHOWING ANOTHER
SORTHWAVE MOVING DOWN TOWARD THE AREA BY EARLY NEXT WEEKEND WITH THE
ECMWF HAVING A SLOWER SOLUTION...SO AGAIN SLIGHT CHANCES SEEM THE
BEST ROUTE. 850MB TEMPS ARE SHOWING A SLOW DECLINE FROM WEDNESDAY
TO SATURDAY AS 500MB HEIGHTS SLOWLY FALL WITH THE PASSAGE OF THE
SHORTWAVES...SO HAVE TEMPERATURES FALLING FROM THE LOWER-MID 90S ON
THURSDAY INTO MAINLY IN THE 80S ON SATURDAY.
BRITT
&&
.AVIATION...
ISSUED AT 1134 AM CDT SUN AUG 5 2012
VFR AND DRY THRU THE TAF PERIOD EXCEPT FOR KSUS...SEE BELOW. NLY
WINDS AROUND 10KTS BECOMING LIGHT AND VRB THIS EVENING AND
REMAINING SO THRU MON MORNING AS SFC RIDGE SETTLES IN ACROSS THE
REGION.
FOR KSUS...OTHER THAN WHAT IS MENTIONED ABOVE...WITH WINDS
BECOMING LIGHT TO CALM AND CLEAR SKIES...GOOD RADIATIONAL COOLING
SHUD OCCUR. THIS MAY ALLOW FG TO FORM LATE TONIGHT. BELIEVE THERE
WILL BE ENUF DRY AIR ADVECTING IN TO PREVENT THIS FROM
DEVELOPING...BUT CONFIDENCE IS TOO LOW TO REMOVE FROM TAF ATTM.
TILLY
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1111 AM CDT SUN AUG 5 2012
.UPDATE...
ISSUED AT 1059 AM CDT SUN AUG 5 2012
QUICK UPDATE MAINLY FOR CLOUDS AND POPS. WITH THE CDFNT SLOWLY
SINKING SWWD...CLOUDS SHUD GRADUALLY CLEAR OUT N TO S. LATEST MDLS
SUGGEST SHRA/TSRA REDEVELOPING ALONG OR JUST S OF THE CWA. HAVE
KEPT POPS FOR MID TO LATE THIS AFTERNOON TO ACCOUNT FOR THIS
REDEVELOPMENT...BUT WITH THE BEST CHANCES FURTHER S...WILL KEEP
ONLY SLIGHT CHANCES GOING FOR NOW. WILL CONTINUE TO MONITOR AND
UPDATE AS NEEDED. THE REMAINDER OF THE FORECAST APPEARS TO BE ON
TRACK ATTM.
TILLY
&&
.SHORT TERM...
ISSUED AT 248 AM CDT SUN AUG 5 2012
(TODAY AND TONIGHT)
FOCUS INITIALLY WILL BE ON EXITING THUNDERSTORMS. LATEST RUNS OF
THE RAP SEEM TO BE IN LINE WITH CURRENT EXTRAPOLATION THAT SURFACE
FRONT WILL BE RIGHT ALONG THE SOUTHERN BORDER OF THE CWA AT 12Z.
AXIS OF SHORTWAVE TROUGH CURRENTLY ALONG THE KS/MO BORDER WILL BE
OVER SOUTHEASTERN MO WITH SOME LINGER 925-850 ALONG AND JUST NORTH
OF THE SFC FRONT. HAVE ISOLATED/SCATTERED THUNDERSTORMS SLOWLY
PUSHING SOUTH OF THE CWA BETWEEN 12-18Z BEFORE SUBSIDENCE SETS IN
BEHIND THE SHORTWAVE. CLOUDS WILL ALSO DECREASE THROUGH MIDDAY AS
LOW-MID LEVEL MOISTURE AND CONVECTIVE DEBRIS MOVES OUT OF THE AREA.
STAYED WITH THE BETTER VERIFYING NAM MOS HIGHS TODAY...PARTICULARLY
WHERE THERE SHOULD BE THE MOST SUN. SKIES WILL BE CLEAR TONIGHT AND
WINDS SHOULD TURN LIGHT EASTERLY BY MORNING AS SURFACE HIGH CENTER
PASSES THROUGH NORTHERN MO/CENTRAL IL. CAN`T RULE OUT SOME FOG
DEVELOPING IN AREAS THAT HAD THE HEAVIEST RAINFALL THE PAST 24 HOURS
LATE TONIGHT/EARLY MONDAY.
BRITT
&&
.LONG TERM...
ISSUED AT 248 AM CDT SUN AUG 5 2012
(MONDAY THROUGH SATURDAY)
DRY WEATHER WILL BE THE RULE MONDAY AND TUESDAY AS LOW LEVEL
MOISTURE WILL BE CUT OFF BY FRONT MOVING THROUGH TODAY AND AREA WILL
BE UNDER MAINLY SUBSIDENCE IN NORTHWESTERLY FLOW ALOFT. NAM/GFS
BOTH SHOW A TROUGH MOVING ACROSS THE MIDWEST ON TUESDAY...BUT THE
BEST ASCENT WILL STAY TO THE NORTH OF THE AREA AS IT BEGINS TO SHEAR
OUT. STAYED CLOSER TO THE NAM MOS FOR HIGHS AS FORECAST SOUNDINGS
ARE SHOWING MIXING UP TO 800MB ON MONDAY AND 700MB ON TUESDAY.
LOWER 90S SEEM REASONABLE ON MONDAY WITH 850MB TEMPS NEAR 20C...AS
DO MIDDLE TO POSSIBLY UPPER 90S ON TUESDAY WITH 20-24C 850MB TEMPS.
DOES LOOK LIKE DEWPOINTS WILL STAY IN THE 50S DURING THE PERIOD
WHICH SHOULD KEEP HEAT INDEX READINGS AT OR BELOW THE AMBIENT
TEMPERATURES.
THE GFS IS SHOWING A DEEPER TROUGH DIGGING IN OVER THE MISSISSIPPI
VALLEY ON THURSDAY THAN IT DID PREVIOUSLY. ECMWF/CANADIAN GEM SHOW
A LESS AMPLIFIED AND SLOWER SOLUTION...SO GOING SLIGHT CHANCES FOR
THUNDERSTORMS SEEM THE BEST ROUTE. THEN GFS IS SHOWING ANOTHER
SORTHWAVE MOVING DOWN TOWARD THE AREA BY EARLY NEXT WEEKEND WITH THE
ECMWF HAVING A SLOWER SOLUTION...SO AGAIN SLIGHT CHANCES SEEM THE
BEST ROUTE. 850MB TEMPS ARE SHOWING A SLOW DECLINE FROM WEDNESDAY
TO SATURDAY AS 500MB HEIGHTS SLOWLY FALL WITH THE PASSAGE OF THE
SHORTWAVES...SO HAVE TEMPERATURES FALLING FROM THE LOWER-MID 90S ON
THURSDAY INTO MAINLY IN THE 80S ON SATURDAY.
BRITT
&&
.AVIATION...
ISSUED AT 552 AM CDT SUN AUG 5 2012
COLD FRONT HAS PASSED JUST S OF COU AND STL EARLY THIS MRNG. MOST
OF THE CONVECTION HAS SHIFTED S OF THE TAF SITES...ALTHOUGH COULD
NOT RULE OUT AN ISOLATED SHOWER TIL 14Z SUN FROM COU TO STL. WILL
LEAVE THE TAFS DRY AS THE PROBABILITY OF ANY MORE RAIN IS QUITE
LOW. BAND OF LOW LEVEL CLOUDS ALONG AND JUST BEHIND THE FRONT FROM
1500-3000 FT IN HEIGHT SHOULD ADVECT SE OF THE STL METRO AREA BY
14-15Z SUN WITH LINGERING VFR LOW-MID LEVEL CLOUD COVER FROM COU
TO STL AREA FOR THE REST OF THE MRNG...THEN MAINLY JUST HIGH LEVEL
CLOUDS CLEARING OUT FROM NW TO SE THIS AFTN. N-NWLY SFC WIND WILL
BECOME LIGHT THIS EVNG AS THE SFC RIDGE OVER THE PLAINS SHIFTS EWD
TO NRN IL TGT. THERE MAY BE SOME FOG LATE TGT ESPECIALLY FOR SUS
DUE TO RECENT RAINFALL ALONG WITH A CLEAR SKY AND LIGHT SFC WIND.
SPECIFICS FOR KSTL...LOW LEVEL CLOUD CEILING AROUND 3000 FT
SHOULD RISE IN HEIGHT LATER THIS MRNG WITH MAINLY JUST HIGH LEVEL
CLOUDS THIS AFTN. NWLY SFC WIND SHOULD INCREASE TO AROUND 10 KTS
LATER THIS MRNG FROM A N-NWLY DIRECTION AS A SFC RIDGE BUILDS SEWD
INTO OUR AREA BEHIND THE COLD FRONT. THE SFC WIND SHOULD BECOME
LIGHT THIS EVNG WITH THE SFC HIGH CENTERED JUST NE OF STL BY 12Z
MON.
GKS
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
650 AM CDT SUN AUG 5 2012
.SHORT TERM...
ISSUED AT 248 AM CDT SUN AUG 5 2012
(TODAY AND TONIGHT)
FOCUS INITIALLY WILL BE ON EXITING THUNDERSTORMS. LATEST RUNS OF
THE RAP SEEM TO BE IN LINE WITH CURRENT EXTRAPOLATION THAT SURFACE
FRONT WILL BE RIGHT ALONG THE SOUTHERN BORDER OF THE CWA AT 12Z.
AXIS OF SHORTWAVE TROUGH CURRENTLY ALONG THE KS/MO BORDER WILL BE
OVER SOUTHEASTERN MO WITH SOME LINGER 925-850 ALONG AND JUST NORTH
OF THE SFC FRONT. HAVE ISOLATED/SCATTERED THUNDERSTORMS SLOWLY
PUSHING SOUTH OF THE CWA BETWEEN 12-18Z BEFORE SUBSIDENCE SETS IN
BEHIND THE SHORTWAVE. CLOUDS WILL ALSO DECREASE THROUGH MIDDAY AS
LOW-MID LEVEL MOISTURE AND CONVECTIVE DEBRIS MOVES OUT OF THE AREA.
STAYED WITH THE BETTER VERIFYING NAM MOS HIGHS TODAY...PARTICULARLY
WHERE THERE SHOULD BE THE MOST SUN. SKIES WILL BE CLEAR TONIGHT AND
WINDS SHOULD TURN LIGHT EASTERLY BY MORNING AS SURFACE HIGH CENTER
PASSES THROUGH NORTHERN MO/CENTRAL IL. CAN`T RULE OUT SOME FOG
DEVELOPING IN AREAS THAT HAD THE HEAVIEST RAINFALL THE PAST 24 HOURS
LATE TONIGHT/EARLY MONDAY.
BRITT
&&
.LONG TERM...
ISSUED AT 248 AM CDT SUN AUG 5 2012
(MONDAY THROUGH SATURDAY)
DRY WEATHER WILL BE THE RULE MONDAY AND TUESDAY AS LOW LEVEL
MOISTURE WILL BE CUT OFF BY FRONT MOVING THROUGH TODAY AND AREA WILL
BE UNDER MAINLY SUBSIDENCE IN NORTHWESTERLY FLOW ALOFT. NAM/GFS
BOTH SHOW A TROUGH MOVING ACROSS THE MIDWEST ON TUESDAY...BUT THE
BEST ASCENT WILL STAY TO THE NORTH OF THE AREA AS IT BEGINS TO SHEAR
OUT. STAYED CLOSER TO THE NAM MOS FOR HIGHS AS FORECAST SOUNDINGS
ARE SHOWING MIXING UP TO 800MB ON MONDAY AND 700MB ON TUESDAY.
LOWER 90S SEEM REASONABLE ON MONDAY WITH 850MB TEMPS NEAR 20C...AS
DO MIDDLE TO POSSIBLY UPPER 90S ON TUESDAY WITH 20-24C 850MB TEMPS.
DOES LOOK LIKE DEWPOINTS WILL STAY IN THE 50S DURING THE PERIOD
WHICH SHOULD KEEP HEAT INDEX READINGS AT OR BELOW THE AMBIENT
TEMPERATURES.
THE GFS IS SHOWING A DEEPER TROUGH DIGGING IN OVER THE MISSISSIPPI
VALLEY ON THURSDAY THAN IT DID PREVIOUSLY. ECMWF/CANADIAN GEM SHOW
A LESS AMPLIFIED AND SLOWER SOLUTION...SO GOING SLIGHT CHANCES FOR
THUNDERSTORMS SEEM THE BEST ROUTE. THEN GFS IS SHOWING ANOTHER
SORTHWAVE MOVING DOWN TOWARD THE AREA BY EARLY NEXT WEEKEND WITH THE
ECMWF HAVING A SLOWER SOLUTION...SO AGAIN SLIGHT CHANCES SEEM THE
BEST ROUTE. 850MB TEMPS ARE SHOWING A SLOW DECLINE FROM WEDNESDAY
TO SATURDAY AS 500MB HEIGHTS SLOWLY FALL WITH THE PASSAGE OF THE
SHORTWAVES...SO HAVE TEMPERATURES FALLING FROM THE LOWER-MID 90S ON
THURSDAY INTO MAINLY IN THE 80S ON SATURDAY.
BRITT
&&
.AVIATION...
ISSUED AT 552 AM CDT SUN AUG 5 2012
COLD FRONT HAS PASSED JUST S OF COU AND STL EARLY THIS MRNG. MOST
OF THE CONVECTION HAS SHIFTED S OF THE TAF SITES...ALTHOUGH COULD
NOT RULE OUT AN ISOLATED SHOWER TIL 14Z SUN FROM COU TO STL. WILL
LEAVE THE TAFS DRY AS THE PROBABILITY OF ANY MORE RAIN IS QUITE
LOW. BAND OF LOW LEVEL CLOUDS ALONG AND JUST BEHIND THE FRONT FROM
1500-3000 FT IN HEIGHT SHOULD ADVECT SE OF THE STL METRO AREA BY
14-15Z SUN WITH LINGERING VFR LOW-MID LEVEL CLOUD COVER FROM COU
TO STL AREA FOR THE REST OF THE MRNG...THEN MAINLY JUST HIGH LEVEL
CLOUDS CLEARING OUT FROM NW TO SE THIS AFTN. N-NWLY SFC WIND WILL
BECOME LIGHT THIS EVNG AS THE SFC RIDGE OVER THE PLAINS SHIFTS EWD
TO NRN IL TGT. THERE MAY BE SOME FOG LATE TGT ESPECIALLY FOR SUS
DUE TO RECENT RAINFALL ALONG WITH A CLEAR SKY AND LIGHT SFC WIND.
SPECIFICS FOR KSTL...LOW LEVEL CLOUD CEILING AROUND 3000 FT
SHOULD RISE IN HEIGHT LATER THIS MRNG WITH MAINLY JUST HIGH LEVEL
CLOUDS THIS AFTN. NWLY SFC WIND SHOULD INCREASE TO AROUND 10 KTS
LATER THIS MRNG FROM A N-NWLY DIRECTION AS A SFC RIDGE BUILDS SEWD
INTO OUR AREA BEHIND THE COLD FRONT. THE SFC WIND SHOULD BECOME
LIGHT THIS EVNG WITH THE SFC HIGH CENTERED JUST NE OF STL BY 12Z
MON.
GKS
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
251 AM CDT SUN AUG 5 2012
.SHORT TERM...
ISSUED AT 248 AM CDT SUN AUG 5 2012
(TODAY AND TONIGHT)
FOCUS INITIALLY WILL BE ON EXITING THUNDERSTORMS. LATEST RUNS OF
THE RAP SEEM TO BE IN LINE WITH CURRENT EXTRAPOLATION THAT SURFACE
FRONT WILL BE RIGHT ALONG THE SOUTHERN BORDER OF THE CWA AT 12Z.
AXIS OF SHORTWAVE TROUGH CURRENTLY ALONG THE KS/MO BORDER WILL BE
OVER SOUTHEASTERN MO WITH SOME LINGER 925-850 ALONG AND JUST NORTH
OF THE SFC FRONT. HAVE ISOLATED/SCATTERED THUNDERSTORMS SLOWLY
PUSHING SOUTH OF THE CWA BETWEEN 12-18Z BEFORE SUBSIDENCE SETS IN
BEHIND THE SHORTWAVE. CLOUDS WILL ALSO DECREASE THROUGH MIDDAY AS
LOW-MID LEVEL MOISTURE AND CONVECTIVE DEBRIS MOVES OUT OF THE AREA.
STAYED WITH THE BETTER VERIFYING NAM MOS HIGHS TODAY...PARTICULARLY
WHERE THERE SHOULD BE THE MOST SUN. SKIES WILL BE CLEAR TONIGHT AND
WINDS SHOULD TURN LIGHT EASTERLY BY MORNING AS SURFACE HIGH CENTER
PASSES THROUGH NORTHERN MO/CENTRAL IL. CAN`T RULE OUT SOME FOG
DEVELOPING IN AREAS THAT HAD THE HEAVIEST RAINFALL THE PAST 24 HOURS
LATE TONIGHT/EARLY MONDAY.
BRITT
&&
.LONG TERM...
ISSUED AT 248 AM CDT SUN AUG 5 2012
(MONDAY THROUGH SATURDAY)
DRY WEATHER WILL BE THE RULE MONDAY AND TUESDAY AS LOW LEVEL
MOISTURE WILL BE CUT OFF BY FRONT MOVING THROUGH TODAY AND AREA WILL
BE UNDER MAINLY SUBSIDENCE IN NORTHWESTERLY FLOW ALOFT. NAM/GFS
BOTH SHOW A TROUGH MOVING ACROSS THE MIDWEST ON TUESDAY...BUT THE
BEST ASCENT WILL STAY TO THE NORTH OF THE AREA AS IT BEGINS TO SHEAR
OUT. STAYED CLOSER TO THE NAM MOS FOR HIGHS AS FORECAST SOUNDINGS
ARE SHOWING MIXING UP TO 800MB ON MONDAY AND 700MB ON TUESDAY.
LOWER 90S SEEM REASONABLE ON MONDAY WITH 850MB TEMPS NEAR 20C...AS
DO MIDDLE TO POSSIBLY UPPER 90S ON TUESDAY WITH 20-24C 850MB TEMPS.
DOES LOOK LIKE DEWPOINTS WILL STAY IN THE 50S DURING THE PERIOD
WHICH SHOULD KEEP HEAT INDEX READINGS AT OR BELOW THE AMBIENT
TEMPERATURES.
THE GFS IS SHOWING A DEEPER TROUGH DIGGING IN OVER THE MISSISSIPPI
VALLEY ON THURSDAY THAN IT DID PREVIOUSLY. ECMWF/CANADIAN GEM SHOW
A LESS AMPLIFIED AND SLOWER SOLUTION...SO GOING SLIGHT CHANCES FOR
THUNDERSTORMS SEEM THE BEST ROUTE. THEN GFS IS SHOWING ANOTHER
SORTHWAVE MOVING DOWN TOWARD THE AREA BY EARLY NEXT WEEKEND WITH THE
ECMWF HAVING A SLOWER SOLUTION...SO AGAIN SLIGHT CHANCES SEEM THE
BEST ROUTE. 850MB TEMPS ARE SHOWING A SLOW DECLINE FROM WEDNESDAY
TO SATURDAY AS 500MB HEIGHTS SLOWLY FALL WITH THE PASSAGE OF THE
SHORTWAVES...SO HAVE TEMPERATURES FALLING FROM THE LOWER-MID 90S ON
THURSDAY INTO MAINLY IN THE 80S ON SATURDAY.
BRITT
&&
.AVIATION...
ISSUED AT 630 PM CDT SAT AUG 4 2012
VFR CONDITIONS EXPECTED OUTSIDE OF ANY TSRA. SFC LOW CURRENTLY
JUST SSE OF KUIN WITH A CDFNT STRETCHING SWWD JUST S OF KJEF TO
JUST N OF KJLN. EXPECT ONGOING TSRA TO CONTINUE EWD AHEAD OF THIS
FNT. LATEST TRENDS SUGGEST THAT TSRA DEVELOPMENT FURTHER
N...IMPACTING KCOU/KSUS/KCPS...IS UNLIKELY TO OCCUR WITH THE
CDFNT. HOWEVER...THERE IS STILL A CHANCE THAT AS THE SFC FNT
STALLS ALONG A COU TO SUS/CPS LINE...SOME SHRA/TSRA WILL DEVELOP
LATE THIS EVENING. DUE TO THE LOW PROBABILITY...WILL COVER WITH A
VCTS FOR NOW. EXPECT COU TO REMAIN DRY THRU THE PERIOD UNLESS THE
ABOVE SCENARIO DEVELOPS. POST-FRONTAL PRECIP ACROSS NRN MO SHUD
REACH UIN IN A COUPLE OF HOURS. LATEST TRENDS SUGGEST THIS MAY BE
LITTLE MORE THAT A LIGHT SHOWER BY THE TIME IT REACHES THE
TERMINAL. WILL MONITOR AS IT APPROACHES.
FOR SUN...SFC RIDGE WILL GRADUALLY BUILD INTO THE REGION WITH NLY
TO NNWLY WINDS AROUND 12 KTS. ANY CLOUDS IN THE MORNING SHUD CLEAR
OUT.
SPECIFICS FOR KSTL...TIMING OF ANY PRECIP TONIGHT IS
UNCERTAIN...IF IT DOES DEVELOP. HAVE MENTION OF VCTS FOR BEST
CHANCES. WINDS WILL BECOME NWLY TO NNWLY BEHIND APPROACHING CDFNT.
CLOUDS SHUD GRADUALLY CLEAR OUT LATE TONIGHT INTO SUN MORNING WITH
NLY WINDS PICKING UP TO AROUND 12KTS. EXPECT VFR CONDITIONS
OUTSIDE OF ANY TSRA.
TILLY
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1144 PM CDT Sat Aug 4 2012
...UPDATED AVIATION DISCUSSION...
.DISCUSSION...
Well, looks like we have to wait for rain again. At least in many
areas this seems to be the appropriate theme for today, as yet
another shortwave/MCV race ahead of the surface front this morning
effectively shoving stabilizing much of northern Missouri and
allowing a weak surface trough to sneak southeast into Missouri and
Kansas. Currently the primary surface trough stretches from Ottumwa,
IA southwest through Kansas City and further south towards Wichita,
KS. A continued stream of mid-level strato-cu has suppressed the
warm surface temperatures in the extreme southern CWA with 88D radar
composites indicating northward extent of surface warm front is just
south of the Pleasant Hill office.
For tonight, highest convective potential remains along our southern
and southeastern tier of counties and again in areas near Kirksville
as mid-level shortwave currently moving through central Kansas
reaches the area after 4pm. HRRR and RAP suggest widely scattered
convection forming along the differential heating axis in the
southern CWA after 4pm with this convection slowly sinking southeast
this evening. Instability and shear plots indicate multi-cell
clusters would be the preferred storm type with downburst winds the
main threat. Elsewhere in areas further north, scattered high based
showers or sprinkles may the result of the weak shortwave and 850
trough passing through the area this evening. Dew points will remain
elevated through the evening as true front is just arriving into the
northwest corner of the CWA.
Will linger chc pops across the southern CWA through the overnight
hours, as 850 mb front stalls. Weak 850:700 mb frontogenesis tied
with the right entrance region of the upr jet may be enough forcing
for west to east ling of elevated convection through early Sunday
morning in west central into central MO.
Sunday-Monday: Surface high pressure will drift southeast into the
region by Sunday morning. North to northeast winds will prevail
through the daytime hours with temperatures struggling to reach the
middle 80s in northern MO and barely hitting 90 towards east central
Kansas and central MO. This surface ridge will quickly slide into
the Ohio river valley by Monday allowing winds to take a more
southerly track. The resultant bump in low-level temperatures will
push daytime highs in the lower to middle 90s.
Tuesday-Friday: The overall longwave pattern will feature a building
ridge over the western CONUS and broad northwesterly flow over the
central and eastern US. GFS/EC/GEM indicate a weak disturbance in
the NW flow pattern moving through as we reach Tuesday night into
Wednesday. Always hard to time these shortwaves and their impact
especially considering the lack of boundary layer moisture. However
one could justify at least a slight chance for precip. Temperatures
will run near or slightly above normal through the end of the week.
31
&&
.AVIATION...
Convection continues to remain well south of the terminals this
evening. Otherwise, VFR conditions expected through the remainder of
the forecast.
Deroche
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1255 AM CDT SUN AUG 5 2012
.AVIATION...06Z KGRI TAF. VFR CONDITIONS TO CONTINUE AT KGRI
THROUGH THE NEXT 24 HOURS. LIGHT AND VARIABLE WINDS WILL BECOME
MORE ESTABLISHED FROM THE SOUTH DURING THE DAY SUNDAY. LITTLE IN
THE WAY OF CLOUD COVER IS CURRENTLY EXPECTED AND VISIBILITY
RESTRICTIONS ARE NOT EXPECTED THROUGH THE NEXT 24 HOURS.
&&
.PREV DISCUSSION... /ISSUED 406 PM CDT SAT AUG 4 2012/
SHORT TERM...THROUGH SUNDAY AFTERNOON. PRIMARY ISSUES THROUGH THE
NEXT 24 HOURS INCLUDE TIMING THE THE LAST FEW HOURS OF LINGERING
ISOLATED/SCATTERED LIGHT PRECIP THROUGH LATE AFTERNOON...FOLLOWED
BY JUST HOW COOL WILL IT GET TONIGHT.
19Z OBJECTIVE SURFACE ANALYSIS CENTERS A 1022MB HIGH OVER
MT/WY...WITH THE RIDGE AXIS EXTENDING DOWN INTO WESTERN NEB. THE
MUCH-AWAITED STRONGEST COLD FRONT WE HAVE SEEN AWHILE HAS PUSHED
WELL OFF TO THE SOUTH AND EAST...NOW ALIGNED ALONG FROM EASTERN IA
TO THE TX PANHANDLE. ALTHOUGH MID AFTERNOON WINDS CONTINUE TO GUST
OVER 20 MPH IN MANY AREAS FROM THE NORTH/NORTHWEST...THEY ARE
STARTING A GRADUAL DECLINE AS THE STRONGEST PRESSURE RISES SLIDE
SOUTHEAST WITH THE FRONT. RADAR IMAGERY AND VISIBLE SATELLITE
AROUND 1930Z GENERALLY CONFIRM THE EARLIER EXPECTATIONS OF
ISOLATED/SCATTERED MAINLY LIGHT HIGH BASED RAIN SHOWERS STARTING
TO INCREASE IN COVERAGE A BIT ACROSS THE SOUTHERN 1/2 OF THE
CWA...ALTHOUGH NO LIGHTNING STRIKES HAVE YET BEEN DETECTED. WATER
VAPOR IMAGERY AND SHORT TERM MODEL DATA REVEAL A SEASONABLY STRONG
MID LEVEL VORT MAX TRACKING EAST NEAR FAR NORTHERN MN...WITH THE
500MB SHORTWAVE AXIS TRAILING SOUTHWEST TO THE LOCAL AREA...WHILE
RIDGING DOMINATES THE SOUTH CENTRAL AND WEST CENTRAL CONUS. TEMP
WISE THIS AFTERNOON...STILL ANTICIPATING SOME LATE DAY SUNSHINE TO
BOOST AT LEAST MUCH OF THE NORTHWEST 1/2 OF THE CWA INTO THE LOW
80S...BUT THE JURY IS STILL OUT ON WHETHER PARTS OF THE
SOUTHEAST...MAYBE EVEN HASTINGS...WILL EVEN MAKE IT TO 80 GIVEN
THE EXTENSIVE MID CLOUDS LINGERING LONGER. SEASONABLY DRY AIR IN
THE FORM OF MID 40S-LOW 50S DEWPOINTS CONTINUE TO INVADE MUCH OF
THE CWA FROM THE NORTHWEST...ALTHOUGH SOME UPPER 50S ARE STILL
HANGING ON IN THE SOUTHEAST.
STARTING OFF WITH THE NEXT FEW HOURS THROUGH 00Z...JUST MADE A
LAST MINUTE DECISION TO PULL THUNDER MENTION ALTOGETHER...AS
LATEST HOURLY MESOANALYSIS AND RAP INSTABILITY PROGS INDICATE
BARELY EVEN 100 J/KG MUCAPE REMAINING IN THE FAR SOUTHEAST
COUNTIES...AND ONGOING LIGHT SHOWERS HAVE NOT EXHIBITED DETECTABLE
LIGHTNING AT ALL OVER THE PAST FEW HOURS. THESE LINGERING SHOWERS
OVER THE NEXT FEW HOURS WILL MAINLY AFFECT LIMITED AREAS SOUTHEAST
OF A LINE FROM HEBRON-STOCKTON...AND WILL CARRY ISOLATED/SCATTERED
SHOWER WORDING FOR JUST A FEW MORE HOURS TO COVER THEM. THIS
LINGERING PRECIP IS CLEARLY TIED TO A QUICKLY DEPARTING MID LEVEL
CONVERGENCE/FRONTOGENETIC ZONE EVIDENT AT 700MB.
GETTING TO THE OFFICIAL NIGHT PERIOD 00Z-12Z...BY THE START OF THE
EVENING ANTICIPATE CONSIDERABLE CLEAR SKIES NEARLY CWA-WIDE...AS
THE BACK EDGE OF THE PRIMARY MID DECK AND ASSOCIATED
SHOWERS/POSSIBLE WEAK STORMS SHOULD BE JUST OFF TO THE SOUTH/EAST
OF THE CWA BY THEN. AS A RESULT...HAVE ESSENTIALLY ZERO POPS
THROUGH THE NIGHT AREA- WIDE...AS THE TRAILING SOUTHWEST PORTION
OF THE POTENT MID LEVEL WAVE CONTINUES EXITING STAGE
RIGHT...REACHING AN AXIS FROM NORTHERN WI TO IL BY 12Z. IN ITS
WAKE...A PLEASANT AND EVEN SEASONABLY COOL NIGHT WILL SETTLE INTO
THE CENTRAL PLAINS. AT THE SURFACE...NORTH BREEZES WILL REALLY
LIGHTEN BY SUNSET...AND BECOME NEARLY CALM THROUGH THE NIGHT IN
SOME AREAS AS A 1023MB HIGH PRESSURE AXIS CENTERS ITSELF DIRECTLY
OVER THE AREA. THE COMBINATION OF THE INVADING DRY AIR...CLEARING
SKIES AND LIGHT BREEZES SHOULD SET THE STAGE FOR A RATHER COOL
NIGHT BY EARLY AUG STANDARDS. LEANED TOWARD THE LOWER END OF 12Z
MET/MAV GUIDANCE FOR LOWS...WHICH RESULTED IN LOWERING PREVIOUS
FORECAST BY 2-4 DEGREES MAINLY IN THE FAR NORTHWEST AND SOUTHERN
COUNTIES. THEREFORE...AM NOW ADVERTISING LOW-MID 50S ALL
AREAS...WITH TYPICAL COOLER SPOTS SUCH AS ORD AND THE PLATTE
VALLEY OF WESTERN DAWSON COUNTY VERY POSSIBLY TAGGING UPPER 40S.
FOR THIS TIME OF YEAR...DEFINITELY LIGHT JACKET WEATHER FOR THOSE
OUT AND ABOUT LATE TONIGHT/EARLY SUNDAY MORNING.
FOR THE SUNDAY DAYTIME 12Z-00Z PERIOD...LITERALLY KEPT POPS ZEROED
OUT CWA-WIDE...AS A BANNER DAY WITH VERY LITTLE...IF ANY CLOUDS IS
FORECAST. IN THE MID-UPPER LEVELS...THE DEPARTING SHORTWAVE WILL
REACH ALL THE WAY TO THE EASTERN GREAT LAKES BY LATE
AFTERNOON...WHILE THE SOUTHERN CONUS 500MB RIDGE AXIS EXPANDS
NORTH AND WEST IN COVERAGE A BIT...BECOMING CENTERED FROM CO/UT
TO OK/NORTHERN TX. THIS WILL LEAVE THE CWA IN FAIRLY LIGHT AND
VERY DRY WEST-NORTHWEST MID LEVEL FLOW. AT THE SURFACE...THE
AFOREMENTIONED RIDGE AXIS WILL START OUT CENTERED OVER THE
AREA...BUT GRADUALLY SLIDE EAST TO NEAR THE MO RIVER BY LATE
AFTERNOON. AS THE HIGH EDGES EAST...LIGHT SOUTHERLY BREEZES WILL
GRADUALLY OVERTAKE MUCH OF THE CWA FROM WEST TO EAST...EVENTUALLY
REACHING INTO THE 10-15 MPH RANGE IN FAR WESTERN COUNTIES...BUT
REMAINING VERY LIGHT/NEAR CALM ALL DAY IN THE FAR EAST NEAR HWY
81. ALTHOUGH THE LIGHT BREEZES/LACK OF MIXING WILL WORK AGAINST
MUCH OF A WARMUP OVER TODAY...PLENTIFUL SUNSHINE AND RELATIVELY
DRY AIR WILL WORK IN FAVOR OF IT. AS HAS BEEN THE CASE FOR SEVERAL
WEEKS NOW...NUMERICAL GUIDANCE HAS PROVEN DIFFICULT TO
EMPLOY...WITH THE MET AVERAGING TOO WARM AND THE MAV TOO COOL. OVERALL
THOUGH...WILL LEAN TOWARD THE WARMER END OF GUIDANCE...AND
ESSENTIALLY JUST BUMPED UP THE PREVIOUS FORECAST 1 DEGREE. THIS
YIELDS NEAR NORMAL HIGHS OF 86-88 MOST AREAS...AND 90-92 IN KS
ZONES AND FURNAS COUNTY AREA. LOWERED DEWPOINTS A BIT FROM
PREVIOUS FORECAST AS WELL...WITH ONLY MID-UPPER 40S SOUTHWEST AND
LOW-MID 50S SOUTHEAST. ALTHOUGH RELATIVE HUMIDITY VALUES COULD
DROP CLOSE TO THE 20 PERCENT CRITICAL FIRE WEATHER THRESHOLD IN A
FEW FAR SOUTHWEST COUNTIES...WINDS SPEEDS WILL FALL WELL SHORT OF
FIRE WEATHER CRITERIA.
LONG TERM...SUNDAY NIGHT THROUGH SATURDAY. MODELS NOT IN TOO BAD
OF AGREEMENT TO START OFF THE LONG TERM PERIOD...SHOWING SUNDAY
EVENING REMAINING UNDER ZONAL/WEAK NORTHWESTERLY FLOW IN THE UPPER
LEVELS...A RESULT OF A BROAD HIGH PRESSURE IN PLACE ACROSS THE
SCENTRAL/SWRN CONUS AND A TROUGH SHIFTING TOWARD THE EAST COAST.
DURING THE OVERNIGHT HOURS...THE FLOW DOES AMPLIFY SOME AS ANOTHER
TROUGH IS MAKING ITS WAY TOWARD THE WEST COAST...BUT NO NOTABLE
DISTURBANCES LOOK TO MOVE THROUGH AND DECIDED TO KEEP THE FORECAST
DRY. HOWEVER...MODELS DO SHOW THE SFC/LOWER LEVEL WINDS REMAINING
S/SWRLY OVERNIGHT...WITH INCREASING VALUES OF ELEVATED INSTABILITY
SHIFTING NORTH INTO THE REGION AS A STRONGER /30-35KT OR SO/ LLJ
DEVELOPS...MAINLY ACROSS THE HIGH PLAINS REGION. THE EDGE OF THIS
LLJ/INSTABILITY AXIS DOES LIE OVER THE WRN PORTIONS OF THE
CWA...AND MAY HAVE TO KEEP AN EYE ON THIS AREA FOR THE POTENTIAL
FOR PERHAPS SOME LIGHT PRECIP /BUT FORECAST SOUNDINGS ARE PRETTY
DRY IN THE LOWER LEVELS/...OR A LITTLE MORE IN THE WAY OF CLOUD
COVER.
INTO MONDAY/MONDAY NIGHT...THE MAIN STORY LIES WITH THE ARRIVAL OF A
MID/UPPER LEVEL WAVE...ASSOCIATED WITH A LOW PRESSURE SYSTEM LOCATED
UP NEAR THE HUDSON BAY. KEPT THE DAYTIME HOURS ON MONDAY
DRY...THOUGH A LITTLE MORE UNCERTAINTY ARISES TOWARD THE LATE
AFTERNOON HOURS...WITH THE ACCOMPANYING SURFACE FRONTAL BOUNDARY
LOOKS TO BE KNOCKING ON THE DOOR OF THE FAR NW CORNER OF THE CWA.
DID RAISE POPS A BIT DURING THE EVENING/OVERNIGHT HOURS ACROSS THE
N/NWRN PORTIONS OF THE CWA...BUT DIDNT MAKE MUCH CHANGE FURTHER
SOUTH. AHEAD OF THE FRONT ON MONDAY...EXPECTING INCREASED SOUTHERLY
WINDS...LIKELY A BIT GUSTY DURING THE AFTERNOON...AND WARMER
TEMPERATURES WITH HIGHS FORECAST TO REACH INTO THE MID/UPPER 90S FOR
MUCH/IF NOT ALL OF THE CWA. CONDITIONS DURING THE AFTERNOON HOURS
SHOULD REMAIN BELOW CRITICAL FIRE LEVELS...RHS COULD DROP INTO THE
LOWER/MID 20S ACROSS THE SOUTH...BUT SUSTAINED WIND SPEEDS ARE
EXPECTED TO REMAIN <20 MPH...THOUGH GUSTS COULD AT TIMES COME CLOSE
TO 25 MPH. WILL BE SOMETHING TO KEEP AN EYE ON IF MODELS HAPPEN TO
TREND UP WINDS/TREND DOWN DPS.
KEPT SOME LINGERING POPS IN DURING THE DAY ON TUESDAY...MAINLY
ACROSS THE SRN HALF OF THE CWA...IN CLOSER PROXIMITY TO WHERE THE
SFC BOUNDARY IS EXPECTED TO BE /SOMEWHERE NEAR OR SOUTH OF THE NEB
AND KS STATE LINE/. CONFIDENCE NOT THE HIGHEST...AS THE PLACEMENT OF
THE FRONT WILL BE DEPENDENT ON HOW THINGS PAN OUT MONDAY NIGHT.
WITH MOST OF THE CWA LOOKING TO BE ON THE NORTH SIDE OF THAT
BOUNDARY...MORE EASTERLY WINDS EXPECTED TO BE IN PLACE...AND
FORECAST HIGHS ARE A TOUCH COOLER THAN MONDAY...MORE IN THE
LOWER/MID 90S. BY 00Z WEDNESDAY...THE UPPER LEVEL PATTERN ACROSS
THE CONUS HAS BECOME MORE AMPLIFIED...WITH MORE SOLIDLY
NORTHWESTERLY FLOW IN PLACE ACROSS THE REGION AS THE RIDGE AXIS
EXTENDS FROM THE DESERT SW THROUGH THE ROCKIES AND INTO CANADA. THE
NOSE OF AN UPPER LEVEL JET STREAK ROUNDING THE TOP OF THE RIDGE AXIS
IS EXPECTED TO SHIFT INTO THE REGION FROM THE NW...BRINGING THE
POTENTIAL FOR MORE PRECIPITATION TUESDAY EVENING/OVERNIGHT. SIMILAR
TO MONDAY/MONDAY NIGHT...WHILE THERE IS INSTABILITY IN PLACE ACROSS
THE REGION...OVERALL DEEP LAYER SHEAR IS CERTAINLY NOT
OUTSTANDING...GENERALLY TOPPING OUT IN THE 25-30 KTS RANGE...SO
WHILE SOME THUNDERSTORMS COULD BE ON THE STRONGER SIDE...NOT
EXPECTING SEVERE WEATHER AT THIS POINT.
INTO WEDNESDAY...MODELS CONTINUE TO SHOW THE NOSE OF THIS UPPER
LEVEL JET IN THE AREA...AND DECIDED TO KEEP SOME LINGERING POPS IN
THE AREA...BUT CONFIDENCE IN CHANCES STICKING AROUND LONGER THAN
PERHAPS A FEW HOURS IN THE MORNING NOT EXACTLY HIGH. THAT LOWER
CONFIDENCE CONTINUES RIGHT ON THROUGH THE REMAINDER OF THE LONG TERM
PERIOD. THE UPPER LEVEL PATTERN REMAINS NORTHWESTERLY ACROSS THE
REGION WITH THE RIDGE STAYING IN PLACE OVER THE CENTRAL
ROCKIES...AND KEPT THE FORECAST DRY AT THIS POINT...WITH MODELS
SHOWING SOME DIFFERENCES WITH DISTURBANCES PASSING TO THE EAST OF
THE CWA...AND WHETHER WE SEE ANY PRECIP AS RESULT. WITH THE
RIDGE/WARMEST AIR REMAINING OFF TO THE WEST OF THE CWA...AND THE
POTENTIAL FOR AN ADDITIONAL FRONTAL PASSAGE...NOTABLY HIGHER
TEMPERATURES ARE NOT EXPECTED...WITH FORECAST HIGHS RANGING FROM
ROUGHLY THE MID 90S WED/THUR TO THE MID 80S TO LOWER 90S FRI/SAT.
PREV DISCUSSION... /ISSUED 1155 AM CDT SAT AUG 4 2012/
CLIMATE...TODAY/TONIGHT WILL LIKELY END UP BEING THE COOLEST
DAY/NIGHT AT GRAND ISLAND AND HASTINGS IN 6.5 WEEKS. BASED ON
FORECAST PROJECTIONS OVER THE NEXT FEW HOURS...THE CALENDAR DAY
HIGH TEMPERATURE AT BOTH GRAND ISLAND AND HASTINGS WILL END UP
SOMEWHERE BETWEEN 78-82 DEGREES...BUT IS GUARANTEED TO BE AT LEAST
78 BECAUSE THIS VALUE WAS REACHED SHORTLY AFTER MIDNIGHT BEFORE
THE COLD FRONT INVADED. FOR GRAND ISLAND...A HIGH OF 79-82 DEGREES
WOULD RESULT IN THE COOLEST DAILY HIGH SINCE JUNE 20TH...WHEN IT
TOPPED OUT AT 79. FOR HASTINGS...A HIGH OF 78-79 DEGREES WOULD
ALSO RESULT IN THE COOLEST DAY SINCE JUNE 20TH...WHEN IT REACHED
78. TURNING TO LOW TEMPERATURES TONIGHT...THE CURRENT FORECAST FOR
BOTH GRAND ISLAND AND HASTINGS CALLS FOR 55. THIS IS ONLY 3
DEGREES ABOVE HASTINGS AUGUST 5TH RECORD LOW OF 52...AND 4 DEGREES
ABOVE THE GRAND ISLAND RECORD LOW OF 51...BOTH SET IN 1994.
ASSUMING IT DIPS TO AT LEAST 57 DEGREES OVERNIGHT...THIS WILL BE
THE COOLEST LOW TEMP IN BOTH CITIES SINCE JUNE 21ST...WHEN GRAND
ISLAND BOTTOMED OUT AT 52 AND HASTINGS 51.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AVIATION...BRYANT
SHORT TERM...PFANNKUCH
LONG TERM...ADO
AREA FORECAST DISCUSSION
NWS ELKO NV
711 PM PDT MON AUG 6 2012
.SYNOPSIS...MONSOON MOISTURE WILL CONTINUE TO BRING A THREAT OF
THUNDERSTORMS TO EASTERN NEVADA THE REST OF THE WEEK.
&&
.UPDATE...ADDED ISOLATED DRY THUNDERSTORMS TO THE WEATHER GRIDS
FOR EXTREME NORTHWESTERN NYE AND LANDER/EUREKA COUNTY ZONES FOR
THIS EVENING. RUC13 500MB VORTICITY SHOWS A MAXIMA IN THE
AREA...COMBINING WITH THE LIMITED MID-LEVEL MOISTURE AND LOW-MID
LEVEL CONVERGENT BOUNDARY TO KICK OFF THESE STORMS. ACTIVITY
SHOULD BEGIN TO WANE IN THE EVENING HOURS. OTHER RELATED GRIDS
WERE ALSO UPDATED AS WELL...WILL SEND TEXT PRODUCTS SHORTLY.
&&
.PREV DISCUSSION... /ISSUED AT 316 PM /
SHORT TERM...TONIGHT THROUGH WEDNESDAY. UPPER RIDGE CENTERED NEAR
THE FOUR CORNERS AREA WILL CONTINUE TO CIRCULATE MOISTURE ACROSS
EASTERN NEVADA THROUGH WEDNESDAY BRINGING ISOLATED AFTERNOON AND
EVENING THUNDERSTORMS. ISOLATED THUNDERSTORMS ARE EXPECTED ACROSS
ALL THE FORECAST AREA EXCEPT HUMBOLDT COUNTY THIS AFTERNOON AND
EVENING. ON TUESDAY THE MOISTURE WILL MOSTLY BE CONFINED TO ELKO
AND WHITE PINE COUNTIES WITH THUNDERSTORMS MAINLY CONFINED TO THE
HIGHER TERRAIN. WEDNESDAY WILL SEE SOME INCREASE IN PWAT VALUES
WITH ISOLATED STORMS OVER ALL BUT HUMBOLDT COUNTY.
LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY. MODELS CONTINUE TO
MAINTAIN NEARLY STATIONARY HIGH PRESSURE CENTERED NEAR THE FOUR
CORNERS REGION BRINGING MODERATE AMOUNTS OF MOISTURE AND INSTABILITY
TO CENTRAL AND EASTERN NEVADA EACH AFTERNOON THIS WEEK FOR ISOLATED
TO SCATTERED THUNDERSTORMS. DRIER AND MORE STABLE AIR IS EXPECTED
ACROSS WESTERN HUMBOLDT COUNTY. STILL EXPECTING TEMPERATURES TO BE 5
TO 10 DEGREES ABOVE NORMAL THROUGH THE PERIOD...WITH HIGHS ACROSS
NORTHERN NEVADA IN THE UPPER 90S TO LOW 100S...AND IN THE LOW TO MID
90S ACROSS CENTRAL NEVADA.
AVIATION...ISOLATED THUNDERSTORMS EXPECTED OVER MOST OF CENTRAL AND
EASTERN NEVADA THROUGH EARLY THIS EVENING...MAINLY IMPACTING KELY
AND KEKO TERMINALS. SKIES CLEAR OUT LATE THIS EVENING.
FIRE WEATHER...ISOLATED DRY THUNDERSTORMS EXPECTED OVER ALL THE
FIRE DISTRICT EXCEPT ZONE 467 THIS AFTERNOON AND EVENING. ISOLATED
DRY THUNDERSTORMS WILL MAINLY BE CONFINED TO ZONE 455/469/470 ON
TUESDAY. SOME INCREASE IN PRECIPITABLE WATER VALUES WILL BRING
SOME WETTING RAINS WITH STORMS ON WEDNESDAY WITH ALL ZONES EXCEPT
467 GETTING ISOLATED STORMS. MONSOON MOISTURE WILL CONTINUE TO
CIRCULATE ACROSS EASTERN NEVADA THURSDAY THROUGH THE WEEKEND FOR A
THREAT OF THUNDERSTORMS.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
86/99
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1159 PM MDT SAT AUG 4 2012
.AVIATION...
06Z TAF CYCLE
BACK DOOR FRONT NOW WEST OF THE MID AND LOWER RIO GRANDE VALLEY
WITH VARYING STRENGTH NE THROUGH SE WINDS THAT MAY STILL GUST ON
OCCASION BETWEEN 25 AND 35 KTS...BUT AVIATION WX WARNING WAS
DROPPED FOR THE ABQ SUNPORT AS SPEEDS AT UPPER END OF THAT RANGE
AT LEAST PARTIALLY CONVECTIVELY INDUCED. FRONT TO CONTINUE
STEADILY SOUTH AND WEST ACROSS SE PLAINS AND TO NEAR CONTINENTAL
DIVIDE AREA BY EARLY MORN. CONVECTION WEST OF RIO GRANDE VALLEY
MAY INCREASE A BIT POST MIDNIGHT PERIOD DUE TO INFLUENCE OF
WESTBOUND FRONT...BUT STRONG STORMS LESS LIKELY THROUGH MORN
HOURS. STILL AT LEAST A FEW AREAS OF MVFR CONDITIONS EXPECTED WITH
STORMS AND AFTER 08 OR 09Z VCNTY OF E SLOPES OF CENTRAL MTN CHAIN
AND E INTO SOME OF ADJACENT HIGHLANDS TO THE E. SHOWERS AND STORMS
AGAIN DEVELOPING AFTER ROUGHLY 18Z SUN...BUT FAVORING NW THIRD TO
HALF OF FCST AREA. SOME LOCALIZED AREAS MVFR WITH THE STRONGER
STORMS...ALONG WITH A FEW INSTANCES OF ASSOCIATED SMALL HAIL AND
WIND GUSTS BETWEEN 30 AND 45 KTS.
43
&&
.PREV DISCUSSION...1038 PM MDT SAT AUG 4 2012...
AFTER CONSIDERABLE REVIEW HERE AT THE WFO LATE THIS EVENING WE HAVE
DECIDED TO CANCEL THE WIND ADVISORY. SCATTERED TO NUMEROUS SHOWERS
AND STORMS OVER THE REGION ARE WREAKING HAVOC ON WIND DIRECTIONS
OVER THE RIO GRANDE VALLEY. WINDS ARE NORTHERLY LOS ALAMOS...SANTA
FE...LAS VEGAS...BELEN...AND SOCORRO. IN THE PAST 30 MINUTES THE
WINDS HAVE BEEN WAFFLING BTWN NORTHEAST AND EAST AT THE SUNPORT
WITH SPEEDS BTWN 15 AND 20KTS. WE CANNOT RULE OUT ANOTHER BURST OF
SLIGHTLY STRONGER WINDS FROM CONVECTION OVER THE ESTANCIA VALLEY
HOWEVER ANY WIDESPREAD ADVISORY WINDS WITHIN THE ZONE ARE NOT
LIKELY. THE 23Z HRRR SOLUTION AND 03Z RUC13 ALSO AGREE WINDS WILL
LIGHTEN UP AND BECOME MORE NORTHERLY AT THE SUNPORT. GUYER
.PREV DISCUSSION...842 PM MDT SAT AUG 4 2012...
RAISED POPS OVER THE CENTRAL VALLEY AND SURROUNDING HIGH TERRAIN
AS THE FRONTAL BOUNDARY INTERACTS MOVES WEST AND INTERACTS WITH
OUTFLOW BOUNDARIES SLIDING EAST FROM A WELL DEFINED COLD POOL
ALONG THE CONT DVD. ALSO SHIFTED ZONE OF HIGHEST POPS FARTHER
SOUTH OVER THE EASTERN PLAINS WHERE THE FRONT HAS MADE IT ALL
THE WAY TO ROSWELL. GUYER
.PREV DISCUSSION...632 PM MDT SAT AUG 4 2012...
.AVIATION...
00Z TAF CYCLE
BACK DOOR COLD FRONT AND ITS EFFECT ON WINDS AND THUNDERSTORM
ACTIVITY TO BE MAIN WEATHER STORY FOR TONIGHT. INITIALLY THROUGH
ABOUT 03 OR 04Z STRONG TO MARGINALLY SEVERE TSRA WILL BE ONGOING NE
OF A LINE FROM SANTA ROSA TO KROW...BUT CHAVES AND ROOSEVELT COUNTY
PORTIONS OF THIS AREA WILL SEE BEST CHANCE STRONG STORMS AFTER ABOUT
01Z. SOME INSTANCES OF HAIL TO PENNY OR QUARTER SIZE LIKELY. FRONT
WILL ALSO BE THE FOCUS FOR FAIRLY WIDESPREAD CONVECTION FROM CENTRAL
MT CHAIN TO PECOS RIVER VALLEY THROUGH THE EVENING. FRONT TO
CONTINUE STEADILY SOUTH AND WEST INTO SOUTHEAST PLAINS AND MIDDLE TO
LOWER RIO GRANDE VALLEY AREA WITH LATTER AREA EXPERIENCING STRONG E
WINDS IN THE 20 TO 30 KT RANGE AND GUSTS BETWEEN 35 AND 45 KTS
STARTING BETWEEN 0130Z AND 03Z...CONTINUING UNTIL SOMETIME BETWEEN
08Z AND 11Z BEFORE DIMINISHING SOMEWHAT. THUS AWW LIKELY NEEDED IN
ABQ VCNTY FROM MID EVE UNTIL A FEW HOURS PAST MIDNIGHT. CONVECTION
WEST OF RIO GRANDE VALLEY LIKELY TO BE MAINLY SCT TO AT TIMES ISOLD.
HEAVY RAIN MORE LIKELY NEAR AND ESPECIALLY E OF RIO GRANDE. AREAS OF
MVFR CONDITIONS EXPECTED WITH THE STRONGER STORMS AND LATE TONIGHT
IN THE E SLOPES OF CENTRAL MTN CHAIN AND E INTO SOME OF ADJACENT
HIGHLANDS TO THE E. STORM STRENGTH TO DIMINISH SOME AFTER ABOUT 06
OR 07Z.
43
.PREV DISCUSSION...318 PM MDT SAT AUG 4 2012...
BACKDOOR COLD FRONT CURRENTLY LOCATED UP ALONG THE EASTERN SLOPES
OF THE SANGRE DE CRISTO MOUNTAINS SOUTH TO MILAGRO...THEN
SOUTHEAST TO PORTALES. SCATTERED THUNDERSTORMS FIRING OVER THE
EASTERN PEAKS AND SLOPES OF THE SANGRES AND ALONG THE CENTRAL
HIGHLANDS SOUTH TO THE SOUTH CENTRAL MTNS. THE FRONT WILL SURGE
WESTWARD THIS EVENING...INTO THE CENTRAL VALLEYS. GIVEN LATEST
MODEL GUIDANCE AS WELL AS PROGGED PRESSURE DIFFERENCES FROM
NORTHEAST TO SOUTHWEST NM INDICATING ADVISORY SPEEDS FOR THE
MIDDLE RIO GRANDE VALLEY TONIGHT. AS A RESULT...DECIDED ON WIND
ADVISORY FOR THE MIDDLE RIO GRANDE VALLEY...MAINLY DOWNWIND OF
TIJERAS CANYON AND FOR THE PLACITAS AREA...ALTHOUGH THE NAM12
SUGGESTING A STRONG SURGE NEAR CREST LEVEL/H7 WHICH WOULD FAVOR
THE WESTERN SANDIA MOUNTAIN FOOTHILLS AS WELL. GFS ON THE OTHER HAND
NOT NEAR AS DEEP WITH A LIGHT SOUTHERLY WIND AT 700 MB OVERNIGHT.
12Z KDEN SOUNDING WOULD SUGGEST THAT THE NAM MAY BE ON TO SOMETHING
AND THAT THE EAST WINDS WILL SPILL OVER THE TOP OF THE SANDIA
MOUNTAIN CREST LATE TONIGHT. LOW LEVEL ELY PUSH SHOULD KEEP ISOLATED TO
SCT SHOWERS AND STORMS GOING OVERNIGHT WITH THE POTENTIAL FOR LOCALLY
HEAVY RAIN FROM CENTRAL MOUNTAINS EAST THIS EVENING. A STRONG
STORM OR TWO IS ALSO POSSIBLE ALONG/NEAR THE FRONT GIVEN THE
STRONG VERTICAL WIND SHEAR PROFILE...WITH HAIL BEING THE MAIN THREAT.
FRONT PUSHES WEST TO THE NM/AZ BORDER BY SUNRISE SUNDAY...SETTING
THE STAGE FOR ANOTHER ACTIVE WEATHER DAY. MAIN AREA OF CONVECTION
IS EXPECTED NORTHWEST OF A GLENWOOD TO CLAYTON LINE. NAM12 HAS
BACKED OFF ON INSTABILITY/LIFTED INDEX VALUES SOMEWHAT FOR SUNDAY
AFTERNOON. THE COOLER AIRMASS AND SCATTERED TO BROKEN CLOUD COVER
TYPICALLY SPELL A LATE START TO WHAT SHOULD TURN OUT TO BE A VERY
ACTIVE LATE AFTERNOON AND EARLY EVENING FOR THE WEST AND NORTHWEST
ZONES. DECIDED ON A FLASH FLOOD WATCH FOR THE WESTERN AND
NORTHWESTERN MOUNTAINS AND VALLEYS...WITH THE LIKELIHOOD OF BACKDOOR
COLD FRONT STALLING NEAR THE CONTINENTAL DIVIDE SUNDAY MORNING...SETTING
UP STRONG SURFACE CONVERGENCE TO EASILY GET NUMEROUS STORMS
GOING. WEAK STEERING LEVEL FLOW OF AROUND 10 KTS AND RECENT HEAVY
RAINS OVER WRN AND NWRN NM WILL MAKE THIS AREA MORE PRONE TO
LOCALIZED FLASH FLOODING SUNDAY AFTERNOON AND EVENING.
ELSEWHERE...FLASH FLOODING REMAINS A CONCERN DUE TO THE WEEK FLOW
AND PRECIPITABLE WATER VALUES OF OVER ONE INCH...BUT TOUGH TO PICK
OUT ANY PARTICULAR AREA OUTSIDE OF A BURN SCAR THAT MAY HAVE AN
ELEVATED RISK DUE TO METEOROLOGICAL FACTORS. LATER SHIFTS MAY NEED
EXPAND THE FLASH FLOOD WATCH FARTHER EAST IF APPARENT SFC
BOUNDARIES SET UP FROM TODAY`S ROUND OF CONVECTION.
CENTER OF THE UPPER LEVEL HIGH EARNS ITS NAME DURING THE COMING
WEEK. THE HIGH MOVES TO JUST WEST OF THE FOUR CORNERS MONDAY AND
REMAINS NEARLY STATIONARY THROUGH THE REMAINDER OF THE WEEK.
PLENTY OF RESIDUAL MOISTURE EXPECTED TO FIRE UP ROUNDS OF MAINLY
MOUNTAIN CONVECTION EACH AFTERNOON...WITH THE POTENTIAL OF
ISOLATED STORMS MOVING OUT OVER LOWER ELEVATIONS IN A SOUTHEAST
DIRECTION MONDAY...DUE SOUTH TUESDAY...THEN SOUTHWEST OR WEST MID-
WEEK.
33
.FIRE WEATHER...
BACK DOOR COLD FRONT PLUNGING SOUTH AND WESTWARD ACROSS PORTIONS OF
THE FORECAST AREA TODAY. MAIN BOUNDARY EXTENDS FROM NEAR PORTALES UP
TO SANTA ROSA AND ABUTTING UP TO THE EAST SLOPES OF THE SANGRES.
THIS FRONT WILL DRIVE FURTHER SOUTH AND WEST REST OF TODAY INTO
TONIGHT. LOOKING AT SOME GUSTIER GAP WINDS ALONG THE CENTRAL
MOUNTAIN CHAIN WITH GUSTS BETWEEN 40 TO POSSIBLY EVEN 50 MPH NEAR
THE TIJERAS/ALBUQUERQUE GAP. LESS MOISTURE TO WORK WITH IN THE
WEST...ESPECIALLY NORTHWEST WITH MORE ABUNDANT MOISTURE CENTRAL
MOUNTAINS EASTWARD. THUS...WETTING RAIN WILL BE MORE PREVALENT
THERE.
DUE TO THE FRONTAL PUSH...THE BEST DYNAMICS COMBINED WITH MOISTURE
WILL SHIFT WESTWARD ON SUNDAY. LOOK FOR WETTING RAINFALL ALONG THE
CONTINENTAL DIVIDE TO THE CENTRAL MOUNTAINS FAVORING THE NORTH
CENTRAL MOUNTAINS AND NORTHWEST THIRD OF THE AREA. UPPER HIGH WILL
BE CENTERED OVER NORTH CENTRAL TEXAS.
THE MODELS STILL POINT TOWARDS AN UPPER HIGH MIGRATION EASTWARD TO
OVER OR NEAR THE FOUR CORNERS REGION THE EARLIER HALF OF NEXT WEEK.
RECYCLING IN THE FORM IF ISOLATED TO SCATTERED THUNDERSTORMS IS
EXPECTED MONDAY AND TUESDAY. TEMPERATURES WILL ALSO BE ON THE WARMER
SIDE. HUMIDITIES COULD FALL INTO THE TEENS FOR A SHORT WHILE ACROSS
THE FOUR CORNERS REGION AS WELL AS LOWER/MID RIO GRANDE VALLEY AND
EASTERN PLAINS DURING THIS PERIOD. DEPENDING ON THE POSITION OF THE
UPPER HIGH AND PERHAPS SOME SORT OF BACK DOOR INFLUENCE...WEDNESDAY
COULD SEE AN UPTICK IN STORM COVERAGE. RIGHT NOW...THE MODELS
INFLUENCE SOUTHERN AND EASTERN AREAS AND THE LATEST GFS IS MORE
BULLISH THAN THE ECMWF. SO WILL HAVE TO SEE ON THAT.
MODELS GET DRIER THURSDAY/FRIDAY OF NEXT WEEK AS THE UPPER HIGH
REMAINS OVER SOME PORTION OF THE FOUR CORNERS AREA. AT THE SAME TIME
A MID LEVEL DRY SLOT OR DRY INTRUSION SHOULD MAKE ITS WAY IN FROM
OVER THE HIGH PLAINS AND START TO REDUCE THUNDERSTORM DEVELOPMENT
ACCORDINGLY. TEMPERATURES WOULD MOST LIKELY REMAIN ABOVE NORMAL.
50
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING FOR
THE FOLLOWING ZONES...NMZ501>507-510-511-517.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1038 PM MDT SAT AUG 4 2012
.UPDATE...
AFTER CONSIDERABLE REVIEW HERE AT THE WFO LATE THIS EVENING WE HAVE
DECIDED TO CANCEL THE WIND ADVISORY. SCATTERED TO NUMEROUS SHOWERS
AND STORMS OVER THE REGION ARE WREAKING HAVOC ON WIND DIRECTIONS
OVER THE RIO GRANDE VALLEY. WINDS ARE NORTHERLY LOS ALAMOS...SANTA
FE...LAS VEGAS...BELEN...AND SOCORRO. IN THE PAST 30 MINUTES THE
WINDS HAVE BEEN WAFFLING BTWN NORTHEAST AND EAST AT THE SUNPORT
WITH SPEEDS BTWN 15 AND 20KTS. WE CANNOT RULE OUT ANOTHER BURST OF
SLIGHTLY STRONGER WINDS FROM CONVECTION OVER THE ESTANCIA VALLEY
HOWEVER ANY WIDESPREAD ADVISORY WINDS WITHIN THE ZONE ARE NOT
LIKELY. THE 23Z HRRR SOLUTION AND 03Z RUC13 ALSO AGREE WINDS WILL
LIGHTEN UP AND BECOME MORE NORTHERLY AT THE SUNPORT. GUYER
&&
.PREV DISCUSSION...842 PM MDT SAT AUG 4 2012...
RAISED POPS OVER THE CENTRAL VALLEY AND SURROUNDING HIGH TERRAIN
AS THE FRONTAL BOUNDARY INTERACTS MOVES WEST AND INTERACTS WITH
OUTFLOW BOUNDARIES SLIDING EAST FROM A WELL DEFINED COLD POOL
ALONG THE CONT DVD. ALSO SHIFTED ZONE OF HIGHEST POPS FARTHER
SOUTH OVER THE EASTERN PLAINS WHERE THE FRONT HAS MADE IT ALL
THE WAY TO ROSWELL. GUYER
.PREV DISCUSSION...632 PM MDT SAT AUG 4 2012...
.AVIATION...
00Z TAF CYCLE
BACK DOOR COLD FRONT AND ITS EFFECT ON WINDS AND THUNDERSTORM
ACTIVITY TO BE MAIN WEATHER STORY FOR TONIGHT. INITIALLY THROUGH
ABOUT 03 OR 04Z STRONG TO MARGINALLY SEVERE TSRA WILL BE ONGOING NE
OF A LINE FROM SANTA ROSA TO KROW...BUT CHAVES AND ROOSEVELT COUNTY
PORTIONS OF THIS AREA WILL SEE BEST CHANCE STRONG STORMS AFTER ABOUT
01Z. SOME INSTANCES OF HAIL TO PENNY OR QUARTER SIZE LIKELY. FRONT
WILL ALSO BE THE FOCUS FOR FAIRLY WIDESPREAD CONVECTION FROM CENTRAL
MT CHAIN TO PECOS RIVER VALLEY THROUGH THE EVENING. FRONT TO
CONTINUE STEADILY SOUTH AND WEST INTO SOUTHEAST PLAINS AND MIDDLE TO
LOWER RIO GRANDE VALLEY AREA WITH LATTER AREA EXPERIENCING STRONG E
WINDS IN THE 20 TO 30 KT RANGE AND GUSTS BETWEEN 35 AND 45 KTS
STARTING BETWEEN 0130Z AND 03Z...CONTINUING UNTIL SOMETIME BETWEEN
08Z AND 11Z BEFORE DIMINISHING SOMEWHAT. THUS AWW LIKELY NEEDED IN
ABQ VCNTY FROM MID EVE UNTIL A FEW HOURS PAST MIDNIGHT. CONVECTION
WEST OF RIO GRANDE VALLEY LIKELY TO BE MAINLY SCT TO AT TIMES ISOLD.
HEAVY RAIN MORE LIKELY NEAR AND ESPECIALLY E OF RIO GRANDE. AREAS OF
MVFR CONDITIONS EXPECTED WITH THE STRONGER STORMS AND LATE TONIGHT
IN THE E SLOPES OF CENTRAL MTN CHAIN AND E INTO SOME OF ADJACENT
HIGHLANDS TO THE E. STORM STRENGTH TO DIMINISH SOME AFTER ABOUT 06
OR 07Z.
43
.PREV DISCUSSION...318 PM MDT SAT AUG 4 2012...
BACKDOOR COLD FRONT CURRENTLY LOCATED UP ALONG THE EASTERN SLOPES
OF THE SANGRE DE CRISTO MOUNTAINS SOUTH TO MILAGRO...THEN
SOUTHEAST TO PORTALES. SCATTERED THUNDERSTORMS FIRING OVER THE
EASTERN PEAKS AND SLOPES OF THE SANGRES AND ALONG THE CENTRAL
HIGHLANDS SOUTH TO THE SOUTH CENTRAL MTNS. THE FRONT WILL SURGE
WESTWARD THIS EVENING...INTO THE CENTRAL VALLEYS. GIVEN LATEST
MODEL GUIDANCE AS WELL AS PROGGED PRESSURE DIFFERENCES FROM
NORTHEAST TO SOUTHWEST NM INDICATING ADVISORY SPEEDS FOR THE
MIDDLE RIO GRANDE VALLEY TONIGHT. AS A RESULT...DECIDED ON WIND
ADVISORY FOR THE MIDDLE RIO GRANDE VALLEY...MAINLY DOWNWIND OF
TIJERAS CANYON AND FOR THE PLACITAS AREA...ALTHOUGH THE NAM12
SUGGESTING A STRONG SURGE NEAR CREST LEVEL/H7 WHICH WOULD FAVOR
THE WESTERN SANDIA MOUNTAIN FOOTHILLS AS WELL. GFS ON THE OTHER HAND
NOT NEAR AS DEEP WITH A LIGHT SOUTHERLY WIND AT 700 MB OVERNIGHT.
12Z KDEN SOUNDING WOULD SUGGEST THAT THE NAM MAY BE ON TO SOMETHING
AND THAT THE EAST WINDS WILL SPILL OVER THE TOP OF THE SANDIA
MOUNTAIN CREST LATE TONIGHT. LOW LEVEL ELY PUSH SHOULD KEEP ISOLATED TO
SCT SHOWERS AND STORMS GOING OVERNIGHT WITH THE POTENTIAL FOR LOCALLY
HEAVY RAIN FROM CENTRAL MOUNTAINS EAST THIS EVENING. A STRONG
STORM OR TWO IS ALSO POSSIBLE ALONG/NEAR THE FRONT GIVEN THE
STRONG VERTICAL WIND SHEAR PROFILE...WITH HAIL BEING THE MAIN THREAT.
FRONT PUSHES WEST TO THE NM/AZ BORDER BY SUNRISE SUNDAY...SETTING
THE STAGE FOR ANOTHER ACTIVE WEATHER DAY. MAIN AREA OF CONVECTION
IS EXPECTED NORTHWEST OF A GLENWOOD TO CLAYTON LINE. NAM12 HAS
BACKED OFF ON INSTABILITY/LIFTED INDEX VALUES SOMEWHAT FOR SUNDAY
AFTERNOON. THE COOLER AIRMASS AND SCATTERED TO BROKEN CLOUD COVER
TYPICALLY SPELL A LATE START TO WHAT SHOULD TURN OUT TO BE A VERY
ACTIVE LATE AFTERNOON AND EARLY EVENING FOR THE WEST AND NORTHWEST
ZONES. DECIDED ON A FLASH FLOOD WATCH FOR THE WESTERN AND
NORTHWESTERN MOUNTAINS AND VALLEYS...WITH THE LIKELIHOOD OF BACKDOOR
COLD FRONT STALLING NEAR THE CONTINENTAL DIVIDE SUNDAY MORNING...SETTING
UP STRONG SURFACE CONVERGENCE TO EASILY GET NUMEROUS STORMS
GOING. WEAK STEERING LEVEL FLOW OF AROUND 10 KTS AND RECENT HEAVY
RAINS OVER WRN AND NWRN NM WILL MAKE THIS AREA MORE PRONE TO
LOCALIZED FLASH FLOODING SUNDAY AFTERNOON AND EVENING.
ELSEWHERE...FLASH FLOODING REMAINS A CONCERN DUE TO THE WEEK FLOW
AND PRECIPITABLE WATER VALUES OF OVER ONE INCH...BUT TOUGH TO PICK
OUT ANY PARTICULAR AREA OUTSIDE OF A BURN SCAR THAT MAY HAVE AN
ELEVATED RISK DUE TO METEOROLOGICAL FACTORS. LATER SHIFTS MAY NEED
EXPAND THE FLASH FLOOD WATCH FARTHER EAST IF APPARENT SFC
BOUNDARIES SET UP FROM TODAY`S ROUND OF CONVECTION.
CENTER OF THE UPPER LEVEL HIGH EARNS ITS NAME DURING THE COMING
WEEK. THE HIGH MOVES TO JUST WEST OF THE FOUR CORNERS MONDAY AND
REMAINS NEARLY STATIONARY THROUGH THE REMAINDER OF THE WEEK.
PLENTY OF RESIDUAL MOISTURE EXPECTED TO FIRE UP ROUNDS OF MAINLY
MOUNTAIN CONVECTION EACH AFTERNOON...WITH THE POTENTIAL OF
ISOLATED STORMS MOVING OUT OVER LOWER ELEVATIONS IN A SOUTHEAST
DIRECTION MONDAY...DUE SOUTH TUESDAY...THEN SOUTHWEST OR WEST MID-
WEEK.
33
.FIRE WEATHER...
BACK DOOR COLD FRONT PLUNGING SOUTH AND WESTWARD ACROSS PORTIONS OF
THE FORECAST AREA TODAY. MAIN BOUNDARY EXTENDS FROM NEAR PORTALES UP
TO SANTA ROSA AND ABUTTING UP TO THE EAST SLOPES OF THE SANGRES.
THIS FRONT WILL DRIVE FURTHER SOUTH AND WEST REST OF TODAY INTO
TONIGHT. LOOKING AT SOME GUSTIER GAP WINDS ALONG THE CENTRAL
MOUNTAIN CHAIN WITH GUSTS BETWEEN 40 TO POSSIBLY EVEN 50 MPH NEAR
THE TIJERAS/ALBUQUERQUE GAP. LESS MOISTURE TO WORK WITH IN THE
WEST...ESPECIALLY NORTHWEST WITH MORE ABUNDANT MOISTURE CENTRAL
MOUNTAINS EASTWARD. THUS...WETTING RAIN WILL BE MORE PREVALENT
THERE.
DUE TO THE FRONTAL PUSH...THE BEST DYNAMICS COMBINED WITH MOISTURE
WILL SHIFT WESTWARD ON SUNDAY. LOOK FOR WETTING RAINFALL ALONG THE
CONTINENTAL DIVIDE TO THE CENTRAL MOUNTAINS FAVORING THE NORTH
CENTRAL MOUNTAINS AND NORTHWEST THIRD OF THE AREA. UPPER HIGH WILL
BE CENTERED OVER NORTH CENTRAL TEXAS.
THE MODELS STILL POINT TOWARDS AN UPPER HIGH MIGRATION EASTWARD TO
OVER OR NEAR THE FOUR CORNERS REGION THE EARLIER HALF OF NEXT WEEK.
RECYCLING IN THE FORM IF ISOLATED TO SCATTERED THUNDERSTORMS IS
EXPECTED MONDAY AND TUESDAY. TEMPERATURES WILL ALSO BE ON THE WARMER
SIDE. HUMIDITIES COULD FALL INTO THE TEENS FOR A SHORT WHILE ACROSS
THE FOUR CORNERS REGION AS WELL AS LOWER/MID RIO GRANDE VALLEY AND
EASTERN PLAINS DURING THIS PERIOD. DEPENDING ON THE POSITION OF THE
UPPER HIGH AND PERHAPS SOME SORT OF BACK DOOR INFLUENCE...WEDNESDAY
COULD SEE AN UPTICK IN STORM COVERAGE. RIGHT NOW...THE MODELS
INFLUENCE SOUTHERN AND EASTERN AREAS AND THE LATEST GFS IS MORE
BULLISH THAN THE ECMWF. SO WILL HAVE TO SEE ON THAT.
MODELS GET DRIER THURSDAY/FRIDAY OF NEXT WEEK AS THE UPPER HIGH
REMAINS OVER SOME PORTION OF THE FOUR CORNERS AREA. AT THE SAME TIME
A MID LEVEL DRY SLOT OR DRY INTRUSION SHOULD MAKE ITS WAY IN FROM
OVER THE HIGH PLAINS AND START TO REDUCE THUNDERSTORM DEVELOPMENT
ACCORDINGLY. TEMPERATURES WOULD MOST LIKELY REMAIN ABOVE NORMAL.
50
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING FOR
THE FOLLOWING ZONES...NMZ501>507-510-511-517.
&&
$$
GUYER
AREA FORECAST DISCUSSION
NWS RALEIGH NC
932 PM EDT MON AUG 6 2012
.SYNOPSIS...
AN UPPER LEVEL TROUGH APPROACHING FROM THE NORTHWEST WILL DRIFT EAST
ACROSS THE CAROLINAS AND SOUTHERN VIRGINIA TONIGHT THROUGH WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 320 PM MONDAY...
A WEAK COLD FRONT WEST OF THE MOUNTAINS WILL STALL FROM EASTERN TN
TO NORTHERN VA THIS EVENING...WHILE THE ASSOCIATED UPPER SHEAR AXIS
SLIPS EAST INTO CENTRAL NC. CONVECTION HAS DEVELOPED ALONG A
DIFFERENTIAL HEATING NEAR THE NC/VA BORDER FROM WIDESPREAD CLOUD
COVER THAT HAS BEEN DRIFTING ALONG AND EAST OF THE FRONTAL
ZONE...AND ALSO OVER SOUTHEAST NC AND COASTAL SC. THE COVERAGE OF
SHOWERS AND STORMS WILL INCREASE FROM THE WESTERN PIEDMONT TO THE
NORTHERN COASTAL PLAIN BY 21Z...AND THEN SLOWLY PUSH EAST ACROSS THE
PIEDMONT THIS EVENING AS THE SHEAR AXIS MOVES OVER THE AREA. MLCAPE
HAS BEEN LIMITED TO LESS THAN 1000 J/KG OVER MOST OF CENTRAL NC THUS
FAR...AND WEAK MID LEVEL FLOW HAS THE 0-6KM EFFECTIVE SHEAR WELL
BELOW 20KT. WITH VERY LITTLE DOWNDRAFT CAPE AND SOUNDINGS BECOMING
INCREASINGLY MOIST ADIABATIC DUE TO PW VALUES OF OVER 2 INCHES...THE
SEVERE THREAT IS LOW THIS EVENING OUTSIDE OF A MORE INTENSE STORM
WILL A PRECIP LOADED DOWNBURST. SOME MINOR FLASH FLOODING IS
POSSIBLE...MAINLY IN URBAN AREAS THIS EVENING AS FLASH FLOOD
GUIDANCE IS RELATIVELY HIGH AREAWIDE.
TONIGHT...
AS THE RIBBON OF VORTICITY ASSOCIATED WITH THE SHEAR AXIS SETTLES
INTO CENTRAL NC TONIGHT...SOME OF THE CAMS ALONG WITH THE HRRR SHOW
THE FOCUS FOR PRECIP SETTING UP ALONG OR JUST WEST OF US HWY 1.
WEAK LAPSE RATES ALOFT AND LIMITED INSTABILITY...COVERAGE SHOULD
DECREASE AFTER MIDNIGHT...BUT SCATTERED SHOWERS AND A FEW ISOLATED
STORMS WILL BE POSSIBLE OVERNIGHT. LOWS IN THE LOWER 70S.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 320 PM MONDAY...
THE UPPER LEVEL SHEAR AXIS AND AXIS OF HIGHER PW WILL SHIFT SLIGHTLY
EAST ON TUESDAY...AND WITH IT THE FOCUS FOR GREAT COVERAGE OF
SHOWERS AND STORMS. CONDITIONS WILL BE VERY SIMILAR TO TODAY WITH
WEAK INSTABILITY AND SHEAR...BUT HIGH PW AND RELATIVELY SLOW
MOVEMENT OF CELLS...WHICH WILL LEAD TO MAINLY AN ISOLATED FLASH
FLOODING THREAT. ONE FEATURE TO NOTE IS AN AREA OF CONVECTION OVER
THE FL PANHANDLE AND ITS ASSOCIATED VORT MAX...WHICH MODELS SHOW
BEING DRAWN NORTH ACROSS GA AND SC ON TUESDAY. THE GFS HAS THE MOST
AGGRESSIVE NORTHWARD TRACK AND BRINGS IT ACROSS THE NC COASTAL
PLAIN LATE TUESDAY NIGHT INTO WEDNESDAY. HOWEVER...THERE IS TOO
MUCH MODEL SPREAD TO PUT MUCH FAITH IN HOW IT MIGHT IMPACT
CONVECTION TUESDAY NIGHT. FOR NOW...WE WILL CONTINUE TO SHOW 70-80
POPS ACROSS THE EAST TUESDAY AFTERNOON...TRENDING DOWNWARD TUESDAY
NIGHT BUT WITH AT LEAST CHANCE POPS OVERNIGHT. UNDER MORE
WIDESPREAD CLOUD COVER...HIGHS SHOULD BE A FEW DEGREES COOLER THAN
TODAY...AND MOST GUIDANCE GIVES LOW TO MID 80S. LOWS TUESDAY NIGHT
IN THE UPPER 60S TO LOWER 70S.
WEDNESDAY THROUGH THURSDAY NIGHT: THE MID/LOW LEVEL TROUGH WEAKENS
AND STALLS OVER THE EAST COAST ON WEDNESDAY...BRINGING THE BEST
CHANCES FOR PRECIP FROM THE COASTAL PLAIN EASTWARD. THE REMNANTS OF
THE SURFACE TROUGH WILL MOVE OFFSHORE WEDNESDAY NIGHT AND THURSDAY
AHEAD OF OUR NEXT LOW PRESSURE/FRONTAL SYSTEM. THIS SHOULD YIELD A
BREAK IN THE PRECIPITATION WEDNESDAY NIGHT AND INTO THURSDAY...WITH
MORE SHOWERS AND THUNDERSTORMS POSSIBLE THURSDAY AFTERNOON AND INTO
THURSDAY NIGHT. HAVE TRENDED MORE TOWARD THE MAV FOR TEMPS...HIGHS
WEDNESDAY IN THE MID 80S WITH LOWS OVERNIGHT IN THE UPPER 60S TO LOW
70S. HIGHS THURSDAY SLIGHTLY WARMER...MID TO UPPER 80S WITH
OVERNIGHT LOWS IN THE LOW 70S
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 320 PM MONDAY...
A COLD FRONT ASSOCIATED WITH AN ANOMALOUSLY STRONG LOW PRESSURE
SYSTEM WILL IMPACT CENTRAL NC AT THE END OF THE WEEK. THE UPPER
LEVEL LOW IS EXPECTED TO DEVELOP OVER CANADA ON WEDNESDAY AND TRACK
SOUTH AND EAST THROUGH MICHIGAN EARLY FRIDAY AND DEEPEN AS IT MOVES
OVER THE GREAT LAKES INTO THE WEEKEND. HAVE MAINLY GONE WITH A BLEND
OF THE ECMWF AND THE 12Z GFS AS THEY ARE IN FAIRLY GOOD AGREEMENT
AND SEEM TO HANDLE THE LOW PRESSURE SYSTEM THE BEST. THE COLD FRONT
ASSOCIATED WITH THIS SYSTEM SHOULD MOVE INTO THE AREA AROUND MID DAY
FRIDAY...BRINGING WITH IT THE POTENTIAL FOR STRONG TO SEVERE STORMS
TO DEVELOP. THE 12Z GFS GENERATES 1500-2000 J/KG OF SURFACE BASED
CAPE OVER CENTRAL NC FRIDAY AFTERNOON...0-6 KM BULK SHEAR VALUES OF
30-40 KTS...MID LEVEL LAPSE RATES OF 6-7 DEGREES C/KM...AND
PRECIPITABLE WATER VALUES OVER 2 INCHES. BOTH MODELS SHOW THE MAIN
PRECIP AXIS MOVING THROUGH CENTRAL NC FROM THE NW THROUGH APPROX 12Z
SATURDAY. THE FRONT COULD THEN LINGER OVER THE COAST THROUGH THE END
OF THE WEEKEND...LEADING TO A CONTINUED CHANCE FOR SHOWERS AND
STORMS OVER THE COASTAL PLAIN DURING THAT TIME. EXPECT HIGHS IN THE
MID TO UPPER 80S THROUGH SUNDAY...WITH SLIGHTLY COOLER TEMPS FOR
MONDAY...LOW TO MID 80S. OVERNIGHT LOWS RANGING FROM THE UPPER 60S
TO LOW 70S THROUGH THE END OF THE PERIOD.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 930 PM MONDAY...
24-HR TAF PERIOD:
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED THE
REMAINDER OF THIS EVENING...THOUGH COVERAGE SHOULD GENERALLY
DECREASE BY 03-06Z AS THE ATMOSPHERE BECOMES INCREASINGLY STABLE.
EXPECT AREAS OF IFR (PERHAPS LIFR) FOG AND/OR LOW CEILINGS OVERNIGHT
(06-12Z) GIVEN RECENT RAINFALL AND A SATURATED GROUND OVER MUCH OF
CENTRAL NC. EXPECT FOG AND LOW CEILINGS TO IMPROVE TO MVFR BY
~15Z...THOUGH MVFR CEILINGS MAY PERSIST THROUGH THE AFTERNOON GIVEN
SUCH A MOIST AIRMASS IN PLACE. SCATTERED TO NUMEROUS SHOWERS AND
STORMS ARE EXPECTED TO DEVELOP AGAIN DURING THE AFTERNOON AND
EVENING AS A SLOW MOVING UPPER LEVEL DISTURBANCE PROGRESSES EASTWARD
THROUGH THE CAROLINAS.
LOOKING AHEAD:
EXPECT CONTINUED ABOVE NORMAL CHANCES FOR SCATTERED TO NUMEROUS
SHOWERS AND STORMS (PRIMARILY DURING THE AFTERNOON/EVENING HOURS)
THROUGH SATURDAY...WITH A CONTINUED POTENTIAL FOR FOG AND LOW
CEILINGS DURING THE PRE-DAWN AND EARLY TO MID MORNING HOURS...
PRIMARILY BETWEEN 06-15Z. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM..SMITH
SHORT TERM...SMITH/KMC
LONG TERM...SMITH
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
346 AM EDT SUN AUG 5 2012
.SYNOPSIS...
WEAK HIGH PRESSURE WILL CONTINUE OVER THE REGION TODAY. A COLD
FRONT WILL STALL NORTH AND WEST OF THE AREA MONDAY AND TUESDAY
BEFORE MOVING INTO THE REGION WEDNESDAY. THE FRONT WILL DISSIPATE
BY LATE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 330 AM SUNDAY...PATCHY LIGHT SHOWERS HAVE DEVELOPED OVER THE
CENTRAL COASTAL SECTIONS AND INLAND OVER THE NORTHERN COASTAL
PLAINS REGION THIS MORNING IN A NICE MID-LEVEL DEFORMATION ZONE.
THE RAP MODEL SHOWS ADDITIONAL SHOWERS APPROACHING THE COASTAL
COUNTIES AFTER SUNRISE BUT WITH LESS COVERAGE THAN ON SATURDAY.
ISOLATED SHOWERS/TSTMS MAY FORM ALONG THE SEA BREEZE DURING THE
AFTERNOON. HAVE INDICATED THE POPS GENERALLY EAST OF HIGHWAY 17
THIS MORNING...THEN SHIFTING INLAND AFTER NOON. TEMPERATURES
SHOULD BE SIMILAR TO YESTERDAY WITH MAXES IN THE UPPER 80S TO
AROUND 90 DEGREES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
AS OF 335 AM SUNDAY...ONCE AGAIN TONIGHT...SOME WEAK MID-LEVEL
VORTICITY WILL ROTATE ALONG THE OUTER PERIPHERY OF THE BUILDING
RIDGE CREATING A LEAST A FEW WIDELY SCATTERED SHOWERS OR TSTMS
ALONG THE SOUTHERN COASTAL COUNTIES TOWARD MORNING. LITTLE CHANGE
IN TEMPERATURE IS EXPECTED FROM PREVIOUS MORNINGS WITH LOWS IN THE
72 TO 78 DEGREE RANGE.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 330 AM SUNDAY...LONG TERM MODELS STILL IN GOOD AGREEMENT ON
SYNOPTIC REGIME...WITH WET AND UNSETTLED WEATHER PATTERN SETTING UP
FOR E NC.
SHORT WAVE TROUGH WILL BYPASS THE AREA TO THE NORTH ON TUE...WITH
TRAILING SFC COLD FRONT PUSHING TOWARDS E NC MON NIGHT AND STALLING
OVER THE AREA THROUGH AT LEAST MID WEEK. BERMUDA HIGH WILL REMAIN
ANCHORED OVER THE SW ATLANTIC BASIN...WHILE BROAD TROUGHING DEVELOPS
OVER THE EAST CENTRAL CONUS. THIS WILL PUT THE AREA UNDER HUMID AND
MOIST SW FLOW...AND WITH STALLED FRONT OVERHEAD PERIODS OF RAIN AND
THUNDERSTORMS WILL PLAGUE E NC BEGINNING LATE MONDAY AND LASTING
THROUGH THE WEEK. RAISED POPS TO LIKELY ON TUE AFTERNOON AS GOOD
AGREEMENT AMONGST MODEL SUITES DEVELOPING WIDESPREAD THUNDERSHOWERS
OVER THE AREA. KEPT HIGH CHANCE WED THROUGH THE END OF THE WEEK AS
MESOSCALE DETAILS NEED TO BE WORKED OUT...THOUGH IT APPEARS A GOOD
SHOT OF RAIN WILL PERSIST. CHANCES FOR SEVERE APPEAR MARGINAL ATTM
ON TUE AS SHEAR WILL BE MEAGER...THOUGH PWATS WILL BE HIGH AND WILL
HAVE TO MONITOR POTENTIAL FOR MINOR FLOODING OF TYPICAL FLOOD PRONE
AREAS.
&&
.AVIATION /08Z SUNDAY THROUGH SUNDAY NIGHT/...
/SHORT TERM TODAY AND TONIGHT/...
AS OF 1 AM SUN...NUMERICAL GUIDANCE AGAIN SHOWS SOME MVFR FOG AND
POSSIBLE STRATUS DEVELOPING OVERNIGHT. THIS SEEMS PLAUSIBLE GIVEN
A DEEP SOUTHERLY FLOW AND VERY MOIST BOUNDARY LAYER. ANY FOG
SHOULD DISSIPATE BY 12 OR 13Z. WDLY SCT TO SCT CONVECTION AGAIN
LIKELY SUN AFTN INLAND WITH BRIEF REDUCTIONS IN CIGS/VSBYS POSS.
/LONG TERM MONDAY THROUGH SATURDAY/...
AS OF 330 AM SUNDAY...MAINLY VFR CONDITIONS WILL PREVAIL...THOUGH
AS IS THE CASE MOST EVENINGS...SOME REDUCTIONS TO MVFR/IFR
POSSIBLE LATE AS RADIATION FOG/LOW STRATUS DEVELOPS...ESP IN AREAS
THAT RECEIVE RAINFALL. SCT TO NUMEROUS THUNDERSHOWERS WILL PLAGUE
THE AREA OFF AND ON LATE MONDAY THROUGH MUCH OF THE WEEK. SOME
REDUCTIONS IN VSBY WITH ANY OF THE HEAVIER THUNDERSHOWERS...AS
WELL AS SOME GUSTY WINDS.
&&
.MARINE...
/SHORT TERM TODAY AND TONIGHT/...
AS OF 335 AM SUNDAY...SAME STORY DIFFERENT DAY WITH REGARDS TO THE
MARINE FORECAST AS LIGHT S/SSW FLOW CONTINUES. WINDS MAY
OCCASIONAL GUST TO NEAR 15 KNOTS...ESPECIALLY NEAR SHOWERS...BUT
WILL GENERALLY RUN AT 10 KNOTS OR LESS. LATEST WAVEWATCH 4 AND
LOCAL SWAN STILL SHOWING ONLY 1 TO 3 FOOT SEAS WITH A MINIMAL 7 TO
8 SECOND SWELL COMPONENT THROUGH TONIGHT.
/LONG TERM MONDAY THROUGH SATURDAY/...
AS OF 330 AM SUNDAY...SOUTHWEST FLOW WILL CONTINUE THROUGH THE LONG
TERM...THOUGH REMAIN SUB SCA THROUGH THUR. SEAS WILL REMAIN IN THE 3
TO OCNL 4 FT RANGE ACROSS OUTER WATERS WITH 2 TO 3 FEET NEARSHORE.
THERE WILL BE CHANCES FOR THUNDERSHOWERS THROUGH THE COMING WEEK AS
A COOL FRONT AND TROUGH SAGS INTO CENTRAL AND EASTERN NC AND STALLS
OUT.
WINDS LOOK TO INC LATE THUR THROUGH SAT AS LOW PRES ACROSS THE GREAT
LAKES COMBINED WITH BERMUDA HIGH TO THE SE ACT TO STRENGTHEN THE
GRADIENT. SEAS WILL INC TO 6 FT IN RESPONSE ACROSS SOUTHERN/CENTRAL
WATERS.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...TL
AVIATION...CTC/TL
MARINE...CTC/TL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
248 AM EDT SUN AUG 5 2012
.SYNOPSIS...
A RATHER ACTIVE WEEK CAN BE EXPECTED AS A SERIES OF COLD FRONTS
MOVE CLOSER TO THE REGION. THE BEST CHANCE OF RAIN OCCURS ON
TUESDAY AND AGAIN FRIDAY AND SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM SATURDAY...SCATTERED SHOWER ACTIVITY IS DISSIPATING
AS EXPECTED AS IT MOVES INLAND OVER A COOLER AND MORE STABLE
NOCTURNAL BOUNDARY LAYER. ADDITIONAL ISOLATED SHOWERS ARE STILL
POSSIBLE OVERNIGHT...ALTHOUGH THE LAST TWO HRRR MODEL RUNS SHOW LESS
AND LESS COVERAGE AS THE NIGHT PROGRESSES. TEMPERATURES AND
DEWPOINTS ARE ON-TRACK AND NO SIGNIFICANT CHANGES ARE NEEDED WITH
THIS UPDATE. PREVIOUS DISCUSSION FROM 730 PM FOLLOWS...
MOIST ONSHORE FLOW WILL CONTINUE THROUGH THE NIGHT WITH 2.0+ INCH
PRECIPITABLE WATER VALUES STREAMING IN. THE ATMOSPHERE WILL REMAIN
CONVECTIVELY UNSTABLE FOR PARCELS ORIGINATING OFFSHORE WHERE SURFACE
AIR TEMPERATURES WILL REMAIN IN THE LOWER 80S WITH MID 70S DEWPOINTS
OVERNIGHT. WE WILL THEREFORE MAINTAIN SMALL POPS WITHIN 20 MILES OF
THE BEACHES FOR ISOLATED SHOWERS BRUSHING BY. SOME OF THESE ARE
ALREADY MOVING ONSHORE IN THE MYRTLE BEACH VICINITY AT THE TIME OF
THIS WRITING. SKIES SHOULD AVERAGE MOSTLY CLEAR TO PARTLY CLOUDY.
WITH A TROPICAL AIRMASS LOW TEMPERATURES SHOULD ONLY FALL INTO THE
LOWER 70S INLAND AND MID 70S AT THE COAST. BEACHES WILL FALL TO THE
UPPER 70S TO NEAR 80 DEGREES WITH ONSHORE BREEZES.
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
AS OF 3:00 AM SUNDAY...BIG STORY WILL BE THE INCREASE OF POPS MONDAY
AND ESPECIALLY TUESDAY VIA HEIGHT FALLS ACCOMPANIED BY A FRONT AT
THE SURFACE. MOST OF THE ACTIVITY WILL BE CONCENTRATED INLAND
MONDAY. TUESDAY OFFERS MORE WIDESPREAD COVERAGE WITH THE COAST
INCLUDED AS A 200MB JET ROTATES ACROSS THE AREA. POPS INCREASE
INCREMENTALLY TUESDAY AFTERNOON BUT REMAIN IN THE GOOD CHANCE
RANGE OVERALL. SPC HAS THE AREA IN A SEE TEXT FOR MONDAY WITH THE
WORDING THAT THE OUTLOOK MAY NEED TO BE ELEVATED TO A SLIGHT RISK.
TEMPERATURE GUIDANCE REMAINS CONSISTENT AS DOES THE OFFICIAL
FORECAST WHICH LEANS HEAVILY TOWARD THE WARMER MAV NUMBERS.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 3:00 AM SUNDAY...MEDIUM RANGE GUIDANCE CONTINUES TO SHOW SUBTLE MID
LEVEL TROUGHING ACROSS THE EASTERN U.S. THROUGH THE PERIOD. AT THE
SURFACE DISSIPATING FRONTAL BOUNDARY WILL MEANDER ACROSS THE AREA
WEDNESDAY WITH ANOTHER FRONT MOVING TO JUST NORTH OF THE AREA BY
LATE IN THE PERIOD TRAILING ANOTHER STRONG SHORTWAVE MOVING ACROSS
THE GREAT LAKES. POPS REMAIN HIGHEST CENTERED AROUND THE STRONGEST
FORCING MECHANISMS...WEDNESDAY WITH THE DECAYING FRONT AND THE
WEEKEND WITH THE SECOND SYSTEM. LATEST MEX GUIDANCE CONTINUES TO
TREND JUST BELOW CLIMATOLOGY AND NUDGED A COUPLE OF PERIODS (LATE)
TO FOLLOW THIS TREND.
&&
.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
AS OF 06Z...VFR EXPECTED THROUGH MUCH OF THE VALID PERIOD. TWO
EXCEPTIONS...POTENTIAL PATCHY/LIGHT FOG AND LOW CEILINGS FOR THE
EARLY MORNING HOURS MAINLY ACROSS INLAND TERMINALS...AND THE THREAT
FOR CONVECTION LATE THIS MORNING FOR COASTAL TERMINALS...AND THIS
AFTERNOON FOR INLAND TERMINALS.
TROPICAL ATMOSPHERE HAS TAKEN OVER THE FA. WILL OCCASIONALLY OBSERVE
ONSHORE MOVEMENT OF MODERATE/TOWERING CU EARLY THIS MORNING. HAVE
INDICATED VCSH FOR THE 2 MYRTLES FROM THIS ONSHORE MOVEMENT. FOR THE
INLAND TERMINALS...COULD SEE A BRIEF PERIOD OF LOW CEILINGS AND BR
LEADING UP TO SUNRISE. AFTER DAYBREAK...ANY LINGERING FOG AND LOW
CEILINGS WILL QUICKLY DISSIPATE ALLOWING FOR VFR TO PREVAIL. WITH A
VERY TROPICAL AIRMASS IN PLACE AND DEEP SE-S FLOW THRU THE ATM
COLUMN...ANTICIPATE MODERATE AND TOWERING CU TO DEVELOP AND/OR MOVE
ONSHORE THROUGHOUT THE DAY. LOOK FOR AN INCREASED POTENTIAL FOR MID
TO LATE MORNING CONVECTION AT THE COAST...MIGRATING TO INLAND
TERMINALS THIS AFTERNOON...WITH THE AID OF THE RESULTANT WIND
BOUNDARY/SEABREEZE. SE TO S WINDS WILL PREVAIL WITH 5 TO 10 KT
INLAND TERMINALS...5 TO 15 KT FOR THE COASTAL TERMS. FOR THE EVENING
HOURS...ANY LINGERING CONVECTION/SHRA SHOULD QUICKLY DISSIPATE
AROUND SUNSET.
FOR THE MYR TAF...WILL NOT INCLUDE VIS AMEND IN THE LAST LINE.
REASON...NO OVERNIGHT VSBY BEING REPORTED IN THE MYR METAR...WHICH
HAS BEEN OCCURRING FOR SEVERAL DAYS NOW.
EXTENDED OUTLOOK...DAILY CHANCE OF MORNING MVFR/IFR VSBYS AND LOW
CEILINGS FROM BR/FG...AND DAILY THREAT FOR DIURNALLY DRIVEN
CONVECTION EACH DAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM SATURDAY...WIND AND SEA OBSERVATIONS ARE SUPPORTED BY
THE CURRENT FORECAST AND NO UPDATES ARE NEEDED. RADAR SHOWS SHOWER
ACTIVITY BECOMING MORE ISOLATED IN NATURE CURRENTLY...AND THE LATEST
COUPLE OF HRRR MODEL RUNS SHOW VERY FEW SHOWERS REMAINING AFTER
MIDNIGHT. PREVIOUS DISCUSSION FROM 730 PM FOLLOWS...
SOUTH-SOUTHEAST WINDS 10-15 KT WILL CONTINUE OVERNIGHT AS WEAK LOW
PRESSURE PUSHES ONTO THE FLORIDA EAST COAST. THIS SAME FLOW HAS
ENOUGH VERTICAL EXTENT TO PUSH SCATTERED SHOWERS NORTH-NORTHWESTWARD
ACROSS THE COASTAL WATERS. LATEST HIGH-RESOLUTION MODELS SHOW THE
BEST COVERAGE FOR THESE SCATTERED SHOWERS SHOULD BE THIS EVENING
WITH A LITTLE LESS COVERAGE AFTER MIDNIGHT. SEAS SHOULD AVERAGE 2-3
FT WITH SPECTRAL WAVE PLOTS SHOWING PEAKS IN POWER AT AROUND 6 AND 8
SECOND PERIODS.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3:00 AM SUNDAY...SOUTHWEST FLOW OF 10-15 KNOTS WILL PREVAIL
ACROSS THE WATERS THROUGH THE PERIOD. STRONGEST WINDS...RELATIVELY
SPEAKING WILL OCCUR LATE MONDAY INTO TUESDAY MORNING WHEN THE LOW
LEVEL JETTING IS MAXIMIZED. SEAS OF 2-4 FEET.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 3:00 AM SUNDAY...THE ONLY DEVIATION FROM THE SUMMER PATTERN OF
SOUTHWEST WINDS OF 10-15 KNOTS IS THE POSSIBILITY OF A FRONT BRIEFLY
SLIDING THROUGH THE WATERS EARLY THURSDAY WHEN WINDS MAY BRIEFLY
TURN TO NORTHWEST. DAYTIME HEATING AND THE QUICK DEVELOPMENT OF THE
SEA BREEZE AND PIEDMONT TROUGH WILL TURN WINDS BACK FROM THE
SOUTHWEST. WAVEWATCH SEAS CONTINUE IN A 2-4 FOOT RANGE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SHK
NEAR TERM...TRA
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1225 AM EDT SUN AUG 5 2012
.SYNOPSIS...
BERMUDA HIGH PRESSURE WILL BRING TYPICAL SUMMER-TIME WEATHER
THROUGH THE WEEKEND...WITH NEAR NORMAL TEMPERATURES AND ISOLATED
TO SCATTERED THUNDERSTORMS. A WEAK TROPICAL WAVE MOVING INTO
FLORIDA COULD BRING COASTAL SHOWERS SUNDAY AND MONDAY. TROPICAL
MOISTURE FROM THE GULF OF MEXICO WILL BRING HUMID AND SOMEWHAT
UNSETTLED CONDITIONS TO THE AREA MUCH OF NEXT WEEK...WITH A
CHANCE OF RAINFALL EACH DAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM SATURDAY...SCATTERED SHOWER ACTIVITY IS DISSIPATING
AS EXPECTED AS IT MOVES INLAND OVER A COOLER AND MORE STABLE
NOCTURNAL BOUNDARY LAYER. ADDITIONAL ISOLATED SHOWERS ARE STILL
POSSIBLE OVERNIGHT...ALTHOUGH THE LAST TWO HRRR MODEL RUNS SHOW LESS
AND LESS COVERAGE AS THE NIGHT PROGRESSES. TEMPERATURES AND
DEWPOINTS ARE ON-TRACK AND NO SIGNIFICANT CHANGES ARE NEEDED WITH
THIS UPDATE. PREVIOUS DISCUSSION FROM 730 PM FOLLOWS...
MOIST ONSHORE FLOW WILL CONTINUE THROUGH THE NIGHT WITH 2.0+ INCH
PRECIPITABLE WATER VALUES STREAMING IN. THE ATMOSPHERE WILL REMAIN
CONVECTIVELY UNSTABLE FOR PARCELS ORIGINATING OFFSHORE WHERE SURFACE
AIR TEMPERATURES WILL REMAIN IN THE LOWER 80S WITH MID 70S DEWPOINTS
OVERNIGHT. WE WILL THEREFORE MAINTAIN SMALL POPS WITHIN 20 MILES OF
THE BEACHES FOR ISOLATED SHOWERS BRUSHING BY. SOME OF THESE ARE
ALREADY MOVING ONSHORE IN THE MYRTLE BEACH VICINITY AT THE TIME OF
THIS WRITING. SKIES SHOULD AVERAGE MOSTLY CLEAR TO PARTLY CLOUDY.
WITH A TROPICAL AIRMASS LOW TEMPERATURES SHOULD ONLY FALL INTO THE
LOWER 70S INLAND AND MID 70S AT THE COAST. BEACHES WILL FALL TO THE
UPPER 70S TO NEAR 80 DEGREES WITH ONSHORE BREEZES.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 PM SATURDAY...OUR AIR MASS BEGINS TO MOISTEN UP SUNDAY
THEN ESPECIALLY MONDAY AS A TROPICAL WAVE MOVES INLAND ACROSS
FLORIDA...AND PREVAILING DEEP SW FLOW GUIDES THE TROPICAL AIR
INTO THE EASTERN CAROLINAS. SURFACE PRESSURE FIELDS REMAIN WEAK
IN THIS TIME FRAME AND MESOSCALE SURFACE FEATURES WILL DICTATE
CONVECTIVE TRENDS...SUCH AS THE LAND BREEZE...SEA BREEZE FRONT
AND OUTFLOW BOUNDARIES. A POTENTIAL FOR LOCALIZED FLOODING EXISTS
SINCE STORM MOTION WILL BE QUITE LAZY IN PULSE TYPE THUNDERSTORMS
WHOSE DOWNBURSTS WILL VERY LIKELY PERPETUATE ADDITIONAL STORMS.
TEMPERATURES WILL ADHERE CLOSE TO CLIMATOLOGY FOR EARLY AUGUST
BUT MINIMUM TEMPERATURES MAY RUN A FEW DEGREES ABOVE NORMAL DUE
TO CLOUDS AND THE VERY TROPICAL AIR MASS ACROSS THE REGION.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 3 PM SATURDAY...PERIOD WILL BE MARKED BY SUBTLE 5H TROUGHING
IN VARYING STRENGTHS. TROUGH AXIS REMAINS WEST OF THE AREA...KEEPING
DEEP MOIST SOUTHWEST FLOW IN PLACE THROUGH SATURDAY. WEAK FRONT
STALLED NORTHWEST OF THE AREA TUE WILL DRIFT INTO THE AREA WED AS IT
WEAKENS...BECOMING LITTLE MORE THAN A SURFACE TROUGH. SEVERAL
FACTORS SUGGEST A CONVECTIVELY ACTIVE LONGER TERM PERIOD. LOW LEVEL
CONVERGENCE ALONG THE SEA BREEZE...SURFACE TROUGH...AND OUTFLOW
BOUNDARIES WILL BE ENHANCED BY DIVERGENCE ALOFT...AS WILL DIURNAL
INSTABILITY. NOR WILL THERE BE A LACK OF DEEP MOISTURE...WITH
FORECAST SOUNDINGS SHOWING PRECIPITABLE WATER VALUES ABOVE 2 INCHES
FOR MUCH OF THE PERIOD. HARD TO PICK WHICH DAYS ARE MORE FAVORABLE
POP WISE THOUGH WED AND FRI STAND OUT. WED WEAK SHORTWAVE MOVES
NORTHEAST FROM THE GULF COAST AND FRI THE 5H TROUGH BECOMES A LITTLE
MORE DEFINED...INCREASING DIVERGENCE. TEMPERATURES WILL REMAIN NEAR
CLIMO THROUGH THE PERIOD.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 06Z...VFR EXPECTED THROUGH MUCH OF THE VALID PERIOD. TWO
EXCEPTIONS...POTENTIAL PATCHY/LIGHT FOG AND LOW CEILINGS FOR THE
EARLY MORNING HOURS MAINLY ACROSS INLAND TERMINALS...AND THE THREAT
FOR CONVECTION LATE THIS MORNING FOR COASTAL TERMINALS...AND THIS
AFTERNOON FOR INLAND TERMINALS.
TROPICAL ATMOSPHERE HAS TAKEN OVER THE FA. WILL OCCASIONALLY OBSERVE
ONSHORE MOVEMENT OF MODERATE/TOWERING CU EARLY THIS MORNING. HAVE
INDICATED VCSH FOR THE 2 MYRTLES FROM THIS ONSHORE MOVEMENT. FOR THE
INLAND TERMINALS...COULD SEE A BRIEF PERIOD OF LOW CEILINGS AND BR
LEADING UP TO SUNRISE. AFTER DAYBREAK...ANY LINGERING FOG AND LOW
CEILINGS WILL QUICKLY DISSIPATE ALLOWING FOR VFR TO PREVAIL. WITH A
VERY TROPICAL AIRMASS IN PLACE AND DEEP SE-S FLOW THRU THE ATM
COLUMN...ANTICIPATE MODERATE AND TOWERING CU TO DEVELOP AND/OR MOVE
ONSHORE THROUGHOUT THE DAY. LOOK FOR AN INCREASED POTENTIAL FOR MID
TO LATE MORNING CONVECTION AT THE COAST...MIGRATING TO INLAND
TERMINALS THIS AFTERNOON...WITH THE AID OF THE RESULTANT WIND
BOUNDARY/SEABREEZE. SE TO S WINDS WILL PREVAIL WITH 5 TO 10 KT
INLAND TERMINALS...5 TO 15 KT FOR THE COASTAL TERMS. FOR THE EVENING
HOURS...ANY LINGERING CONVECTION/SHRA SHOULD QUICKLY DISSIPATE
AROUND SUNSET.
FOR THE MYR TAF...WILL NOT INCLUDE VIS AMEND IN THE LAST LINE.
REASON...NO OVERNIGHT VSBY BEING REPORTED IN THE MYR METAR...WHICH
HAS BEEN OCCURRING FOR SEVERAL DAYS NOW.
EXTENDED OUTLOOK...DAILY CHANCE OF MORNING MVFR/IFR VSBYS AND LOW
CEILINGS FROM BR/FG...AND DAILY THREAT FOR DIURNALLY DRIVEN
CONVECTION EACH DAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM SATURDAY...WIND AND SEA OBSERVATIONS ARE SUPPORTED BY
THE CURRENT FORECAST AND NO UPDATES ARE NEEDED. RADAR SHOWS SHOWER
ACTIVITY BECOMING MORE ISOLATED IN NATURE CURRENTLY...AND THE LATEST
COUPLE OF HRRR MODEL RUNS SHOW VERY FEW SHOWERS REMAINING AFTER
MIDNIGHT. PREVIOUS DISCUSSION FROM 730 PM FOLLOWS...
SOUTH-SOUTHEAST WINDS 10-15 KT WILL CONTINUE OVERNIGHT AS WEAK LOW
PRESSURE PUSHES ONTO THE FLORIDA EAST COAST. THIS SAME FLOW HAS
ENOUGH VERTICAL EXTENT TO PUSH SCATTERED SHOWERS NORTH-NORTHWESTWARD
ACROSS THE COASTAL WATERS. LATEST HIGH-RESOLUTION MODELS SHOW THE
BEST COVERAGE FOR THESE SCATTERED SHOWERS SHOULD BE THIS EVENING
WITH A LITTLE LESS COVERAGE AFTER MIDNIGHT. SEAS SHOULD AVERAGE 2-3
FT WITH SPECTRAL WAVE PLOTS SHOWING PEAKS IN POWER AT AROUND 6 AND 8
SECOND PERIODS.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 PM SATURDAY...SINCE ERNESTO WILL TRACK ACROSS THE SOUTHERN
CARIBBEAN...ISLANDS WILL BLOCK ANY CHANCE OF LONG PERIOD WAVES
REACHING THE NC COAST SUNDAY AND MONDAY. SE WINDS AROUND 15 KT
SUNDAY WILL BUILD SEAS TO 3-4 FEET PRIMARILY IN SE WAVES WITH WAVE
INTERVALS AROUND 6-7 SECONDS SUNDAY. WINDS WILL TURN SOUTHERLY
AND EASE A BIT MONDAY AS A WEAK TROPICAL WAVE MOVING ACROSS
FLORIDA BREAKS INTO THE GULF OF MEXICO. SEAS MAY SUBSIDE A FOOT
OR SO MONDAY...BUT RESIDUAL WAVE ENERGY FROM THE SSE FETCH COULD
KEEP SEA HEIGHTS STEADY AND A 2-4 FOOT RANGE...HIGHEST OFFSHORE
UN-CONSUMED BY BOTTOM FRICTION AND SHOALING. ALL MARINERS ARE
ENCOURAGED TO GET A FIX ON RADAR TRENDS BEFORE HEADING OUT TO
ASCERTAIN THE THREAT OF OCEAN STORMS...SINCE THE TROPICAL AIR
MASS WILL SUPPORT ISOLATED TO SCATTERED STORMS JUST ABOUT ANY
TIME OF DAY.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3 PM SATURDAY...BERMUDA HIGH AND STALLED FRONT/PIEDMONT TROUGH
WILL MAINTAIN THE TYPICAL SUMMERTIME CONDITIONS ACROSS THE WATERS.
SOUTHWEST FLOW WILL GENERALLY RANGE BETWEEN 10 AND 15 KT AND SEAS
RUNNING 2 TO 3 FT WITH ISOLATED 4 FT WELL AWAY FROM SHORE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...MJC
LONG TERM...III
AVIATION...DCH/SGL
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
137 AM EDT SUN AUG 5 2012
.SYNOPSIS...
MUGGY AUGUST AIR THROUGH WEEKEND. WITH A LOCAL DOWNPOUR POSSIBLE.
MORE WIDESPREAD AND ORGANIZED CONVECTION LIKELY SUNDAY...WELL AHEAD
OF COLD FRONT. DRIER AIR TRIES TO CREEP SOUTH MONDAY.
&&
.NEAR TERM /THROUGH TODAY/...
130 AM UPDATE...NO SIGNIFICANT CHANGES MADE TO ONGOING FORECAST.
PREVIOUS DISCUSSION...
CONVECTION CURRENTLY DEVELOPING IN ASSOCIATION WITH WEAK VORT MAX
SHOWING UP ON RAP MOVING INTO CWA FROM THE WEST. DOWNPOURS WILL BE
POSSIBLE WITH THESE STORMS...AND ISOLATED FLASH FLOODING MAY OCCUR.
NOT EXPECTING FLASH FLOOD THREAT TO BE WIDESPREAD ENOUGH TO WARRANT
A SHORT FLASH FLOOD WATCH THOUGH THIS EVENING. TOMORROW IS ANOTHER
STORY...MOISTURE CONTINUES TO INCREASE OVERNIGHT...WITH PWAT VALUES
CLIMBING TO OVER 2.25 INCHES BY 18Z SUNDAY ON THE NAM AND GFS.
EXPECT WIDESPREAD PRECIPITATION...WITH VERY HEAVY RAINFALL SUNDAY
AFTERNOON INTO SUNDAY NIGHT...AND OPTED TO ISSUE A FLASH FLOOD WATCH
FOR LINE ROUGHLY HTS TO CKB AND SOUTH. ONE THING TO WATCH WILL BE
STORM SPEEDS...WITH 20-30KTS MID LEVEL FLOW...STORMS WILL BE
PROGRESSIVE...BUT WITH FLASH FLOOD GUIDANCE BETWEEN 1.5 AND 2 INCHES
ACROSS A LOT OF THE WATCH AREA...EVEN STORMS THAT ARE MOVING COULD
EASILY REACH THIS THRESHOLD. PLUS...IF ANY TRAINING CELLS OCCUR
THREAT WILL INCREASE GREATLY. AS FOR SEVERE THREAT...MODELS HAVE
BEEN BACKING OFF ON INSTABILITY A BIT. THINK THIS IS A GOOD
TREND...DUE TO MORE CLOUDS LEADING TO LESS HEATING.
STILL...1500-2000 J/KG CAPE SHOULD BE ENOUGH TO TAP INTO GOOD
MID-LEVEL FLOW AND PRODUCE STRONG TO SEVERE WIND GUSTS IN THE TALLER
STORMS.
BLENDED IN MET GUIDANCE FOR TEMPS OVERNIGHT...AS IT HAS BEEN
PERFORMING QUITE WELL LATELY...WHICH RESULTED IN MINIMAL CHANGES.
WITH MORE CLOUDS AROUND...BLENDED IN THE MAV FOR HIGHS TOMORROW
LIKING ITS DEPICTION OF COOLER TEMPS IN SE OHIO WHERE PRECIP WILL
REACH FIRST. THIS RESULTED OVERALL IN A BIT COOLER DAY THAN PREVIOUS
FORECAST.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY/...
WE ARE HOPING THE PREFRONTAL CONVECTION DOES NOT ORIENT MORE EAST TO
WEST...BUT THE FLASH FLOOD WATCH WAS POSTED EARLY...FOR THAT
POSSIBILITY. AS WE HEAD INTO SUNDAY EVENING...OUR SOUTHERN COUNTIES
SEEM TO BE MORE VULNERABLE TO SOME TRAINING...DESPITE THE 25 TO 30
KNOT CELL MOVEMENT THAT WE ARE EXPECTED.
WILL BASE FORECAST ON SURFACE FRONT FROM NEAR EKN TO CRW TO SOUTH OF
HTS AT 12Z MONDAY. SO HAD TO LEAVE SOME CHANCE POPS ALONG THAT
FEATURE. PICTURING LOW CLOUDS ALONG THAT FRONT TOO. PROBABLY MOSTLY
JUST LINGERING RAIN SHOWERS RATHER THAN THUNDER.
PROBLEM THEN BECOMES...HOW LONG TO LINGER SOME 20/30 POPS IN OUR
EXTREME SOUTH INTO TUESDAY. WE ARE TYPICALLY LEARY OF THE DRIER AIR
IN THE LOW LEVELS MAKING IT THROUGH THE SOUTHERN MOUNTAINS. SO EVEN
THOUGH THE MID LEVELS SHOULD DRY OUT...WILL NOW HOLD ONTO SOME 20/30
POPS IN SW VIRGINIA TO NEAR BECKLEY FOR TUESDAY.
THERE COULD BE WIDESPREAD FOG MONDAY NIGHT FROM EKN TO CRW INTO THE
COAL FIELDS. YET...BEING THE THIRD NIGHT INTO THE FUTURE...WILL HOLD
OFF INCLUDING THOSE SPECIFICS FOR NOW.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
12Z GFS AND 12Z ECMWF SOLUTIONS CONTINUE TO AGREE THAT THE MID LEVEL
RIDGE...BAKING THE PLAINS THIS SUMMER...WILL SLIDE BACK WEST INTO
THE GREAT BASIN...WITH A STRONG TROF SWINGING THROUGH OUR VICINITY
ON DAY 7...WITH THE SURFACE FRONT LIKELY AHEAD OF IT...ON DAY
6/FRIDAY.
PROBLEM FOR WEDNESDAY AND THURSDAY IS THE DEEP MOISTURE LINGERING TO
OUR SOUTHEAST. WILL TRY TO HOLD WEDNESDAY DRY MAINLY FOR COUNTIES
NORTH OF A HTS-CRW-EKN LINE...WITH SOME 20/30 POPS ALONG OUR
SOUTHEASTERN COUNTIES WEDNESDAY. WENT ALONG WITH HPC MEDIUM RANGE
CHANCE POPS FOR THURSDAY AND FRIDAY...WITH A COOL DOWN FOR SATURDAY.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
06Z SUNDAY THRU 06Z MONDAY...GENERALLY VFR CEILINGS 5000-8000
FEET DEVELOPING OVERNIGHT MINIMAL FOG IF ANY DUE TO SOUTHERLY
BREEZES BEING MAINTAINED.
AFTER 12Z...COLD FRONT APPROACHES FROM THE WEST WITH INCREASING
SHOWERS AND THUNDERSTORMS FROM WEST TO EAST ON SUNDAY. SOME STORMS
MAY BE SEVERE. INTERMITTENT MVFR/IFR CONDITIONS WILL LIKELY RESULT
IN STRONGER STORMS. OUTSIDE OF STORMS GENERALLY VFR CEILINGS 3500-4500
FEET BEFORE LOWERING AROUND 21Z. EXPECT GUSTY SOUTHWEST WINDS
AHEAD OF THE FRONT ON SUNDAY. IFR CIGS WILL BE POSSIBLE MAINLY AT
NORTHERN STIES AFTER 00Z MONDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z MONDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING AND INTENSITY OF SHOWERS AND
THUNDERSTORMS SUNDAY MAY VARY...AND WILL DEPEND OF AMOUNT OF
CLOUDS AND HEATING. FLIGHT CONDITIONS MAY VARY MAINLY AFTER 18Z.
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 SUN 08/05/12
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 H H H H H
HTS CONSISTENCY H H H 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 M M M H H H M H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 06Z MONDAY...
IFR POSSIBLE IN LOW STRATUS NEAR SURFACE FRONT MONDAY
MORNING...MAINLY AT SOUTHERN AND EASTERN SITES.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLASH FLOOD WATCH FROM 11 AM EDT THIS MORNING THROUGH LATE
TONIGHT FOR WVZ005-006-013>020-024>040-046-047.
OH...FLASH FLOOD WATCH FROM 11 AM EDT THIS MORNING THROUGH LATE
TONIGHT FOR OHZ087.
KY...FLASH FLOOD WATCH FROM 11 AM EDT THIS MORNING THROUGH LATE
TONIGHT FOR KYZ101>103-105.
VA...FLASH FLOOD WATCH FROM 11 AM EDT THIS MORNING THROUGH LATE
TONIGHT FOR VAZ003-004.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...MZ/50
SHORT TERM...KTB/ARJ
LONG TERM...KTB
AVIATION...50
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
620 PM EDT SUN AUG 5 2012
.SYNOPSIS...
A COLD FRONT WILL PUSH ACROSS NORTHWESTERN PENNSYLVANIA THIS
EVENING...AND THROUGH THE REMAINDER OF THE COMMONWEALTH OVERNIGHT.
HIGH PRESSURE WILL BUILD INTO THE STATE LATER MONDAY BEFORE
BECOMING CENTERED OVER THE REGION MONDAY NIGHT. NOTICEABLY LOWER
HUMIDITY AND NEAR NORMAL TEMPERATURES WILL OCCUR DURING THE FIRST
HALF OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
RECENTLY CANCELLED SVR TSTM WATCH 564 FOR THE SEVERAL COUNTIES IN
THE SERN PART OF OUR CWA.
SFC COLD FRONT NEARING THE SOUTH SHORE OF LAKE ERIE AT 22Z. SOME
SIGNIFICANT BREAKS IN THE CLOUD COVER AND HAS LED TO A RECOVERY
OF THE ATMOS TO MDT INSTABILITY ACROSS SWRN PENN WITH MU CAPES OF
AROUND 2000 J/KG...AND SEVERAL BANDS OF MDTLY STRONG 925-850 MB
THETA-E CONVERGENCE /FCST BY THE 21Z RUC FOR THIS EVENING/ HELPING
TO SPARK A BKN LINE OF LOW-TOPPED SHRA/TSRA FROM NEAR KDUJ...SW
TO KAGC...AND A WEAKER LINE OF SHRA NEAR KBFD.
ISOLATED TO SCATTERED SHRA/TSRA WILL DRIFT GRADUALLY EAST ACROSS
THE FCST AREA EARLY TONIGHT...ALONG AND AHEAD OF THE COLD FRONT. A
FEW OF THE TSRA ACROSS OUR SOUTHERN ZONES COULD GROW TALL ENOUGH
TO MAKE SOME SMALL HAIL AND PERHAPS BRING A BRIEF WIND GUST OF
30-40 MPH...BUT LITTLE CHC FOR THE CONVECTION REACHING SEVERE
CRITERIA AS THE HEATING/SUN WEAKENS.
SCATTERED SHOWERS AND ISOLATED TSRA SHOULD DIMINISH AFTER
MIDNIGHT...FOLLOWED BY WHAT MIGHT BE SHORT-LIVED CLEARING IF THE
RAIN KEEPS BLYR MOISTURE HIGH. BUT ENOUGH PRE-SUNSET DRYING WILL
ACT TO BALANCE THIS POTENTIAL TROUBLE. WILL JUST GO P/CLDY FOR
MOST OF THE NIGHT...WITH HIGHER SKY COVER NUMBERS IN THE GRIDS
ACROSS THE S. MIN TEMPS WILL RANGE FROM THE U50S NW WHERE DRIER
AIR INFILRATES...TO AROUND 70F IN THE SE.
&&
.SHORT TERM /MONDAY/...
MONDAY WILL FEATURE DRYING OVER THE AREA AS HIGH PRESSURE SLIDES
IN FROM THE WEST. MORNING FOG OR STRATUS WILL BURN OFF QUICKLY.
TEMPS SHOULD REBOUND NORMAL IN MANY AREAS THANKS TO THE SUNSHINE.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
CENTER OF SFC HIGH SETTLES OVER PA MON NIGHT/TUE BRINGING A DRY
FIRST HALF OF THE NEW WEEK. THOUGH NW-W FLOW ALOFT CONTINUES MUCH
OF THE WEEK...A WEAK BOUNDARY SETS UP OFF THE ATLANTIC COAST
MIDWEEK - NUDGING LOW LEVEL MOISTURE BACK INTO EASTERN PORTION OF
CWA. SO KEPT MENTION OF SLIGHT CHANCE FOR A TSTM WED/THU AS
HUMIDITY SLOWLY INCREASES. MORE POTENT TROUGH APPROACHES IN NW
FLOW FOR THU NIGHT-FRI NIGHT. MODELS HANDLING THIS FEATURE
WELL...THOUGH GFS STILL TRIES TO LIFT TROUGH NORTHWARD. EITHER
WAY...MOISTURE CONTINUES TO SLOWLY INCREASE AS FLOW TURNS SW AHEAD
OF TROUGH. CHANCE/SCATTERED SHOWERS/TSTMS FITS THE BILL BEFORE
JUST ISOLATED CONVECTION POSS THIS WEEKEND.
AFTER A COOL NIGHT MON NIGHT...TEMPERATURES WILL GRADUALLY RISE
SLIGHTLY ABOVE NORMAL FOR MIDWEEK. HUMIDITY INCREASES LATE WEEK
AHEAD OF APPROACHING TROUGH...MAKING IT FEEL MORE MUGGY. THEN
TEMPS COOL BACK DOWN FOR NEXT WEEKEND.
&&
.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
MVFR OVER THE WRN TAFS WILL CONTINUE FOR THE NEXT FEW HRS...AS
DRIER AIR BEHIND THE FRONT IS STILL QUITE A FEW HRS AWAY. HEATING
FROM STRONG SUNSHINE HAS DEVELOPED STRONG/SEVERE THUNDERSTORMS IN
THE CENTRAL COS WHICH HAVE MOVED TO THE EAST STEADILY. BRIEF
REDUCTIONS TO MVFR A COLD FRONT WILL OCCUR AT KMDT/KLNS - BUT MOST
OF THE REST OF THE PERIOD SHOULD BE VFR OR MVFR AT WORST WITH ONLY
ISOLD/SCT SHRA. IT COULD TAKE UNTIL AT LEAST 06Z TO PUSH THE LAST
OF THE SHRA SSOCD WITH THE FRONT THROUGH THE SERN TERMINALS. FOG
AND LOW CLOUDS ARE POSSIBLE LATER TONIGHT AFTER THE FROPA. MON
SEEMS VFR AFTER ANY EARLY FOG/STRATUS.
OUTLOOK...
.TUE-THU...NO SIG WX.
.FRI...TSRA/SHRA POSSIBLE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...DANGELO
LONG TERM...LAMBERT/RXR
AVIATION...DANGELO
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
158 AM EDT SUN AUG 5 2012
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL BRING AN INCREASE IN HUMIDITY AND
SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS THIS EVENING...AND
AGAIN ON SUNDAY. SOME OF WHICH MAY BE STRONG TO SEVERE ON
SUNDAY...BEFORE DRIER AIR BUILDS IN FOR EARLY NEXT WEEK.
OVERALL THE PATTERN FOR EASTERN NORTH AMERICA IS IN TRANSITION
WITH THE EXPECTED DEVELOPMENT OF A BROAD TROUGH OVER THE NEXT 4 TO
8 DAYS.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
SCT-BKN ALTO CU CLOUDS /THE REMNANTS OF EARLIER CONVECTION/ WILL
CONTINUE TO DRIFT EAST ACROSS THE FCST AREA OVER THE NEXT SEVERAL
HOURS.
A SHIELD OF THICKENING CIRRUS BLOWING OFF THE WRN OHIO MCS WILL
SPREAD INTO THE WRN MTNS BY 05Z.
THE EASTERN EDGE OF A NORTH/SOUTH BAND OF ANOMALOUSLY HIGH PWATS
OF NEARLY 2 INCHES WILL EDGE INTO THE FAR NW ZONES TWD DAYBREAK
SUNDAY...ACCOMPANIED BY INCREASING LLVL SOUTH SOUTHWESTERLY SHEAR.
850 MB WINDS WILL INCREASE TO AROUND 35 KTS OVERNIGHT...WHICH
RANKS ABOUT 3 STANDARD DEVIATIONS FROM NORMAL.
THIS INCREASING LOW LEVEL FORCING AND HIGH AMOUNT OF MOISTURE WILL
SUPPORT ANOTHER FEW CLUSTERS OF LATE NIGHT SHOWERS AND SCATTERED
TSRA MOVING ACROSS PORTIONS OF THE CWA WELL AFTER MIDNIGHT.
A LINE OF STRONG TO SVR TSRA WAS RACING EAST TWD NCENT OHIO AT
AROUND 45 KTS LATE THIS EVENING. THIS LINE OF INTENSE CONVECTION
SHOULD WEAKEN A BIT LATE TONIGHT AS IT MOVES INTO THE SLIGHTLY
LESS UNSTABLE AIRMASS ACROSS CENTRAL AND WRN PENN.
LINEAR EXTRAPOLATION OF THE OHIO SQUALL LINE PLACES IT ACROSS THE
MTNS OF WRN PENN BY AROUND 07Z...AND NEAR THE SUSQ MAINSTEM AROUND
09Z SUNDAY. AGAIN...PRIOR TO THIS WEAKENING LINE OF
TSRA...ANOMALOUSLY STRONG 850 MB MOISTURE FLUX SHOWN BY THE SREF
WILL SUPPORT ADDITIONAL...DISCRETE TSRA MOVING NE IN ITS ADVANCE.
SHORT RANGE MODELS SUCH AS THE HRRR AND 4 KM NAM CONCUR ON THE
REGENERATION OF CONVECTION IN THE FORM OF SCATTERED TSRA WELL
AFTER MIDNIGHT...BUT DON/T SEEM TO BE LOCKING ONTO THE THE CURRENT
OHIO MCS AT ALL. HRRR FIRES UP TSRA ACROSS THE LAURELS AND CENTRAL
MTNS...WHILE IN CONTRAST THE 4 KM NAM SHOWS A FAIRLY LARGE AREA OF
SHOWERS/TSRA MOVING NE NEAR AND JUST TO THE SE OF INTERSTATE 81
AFTER 05Z.
LOWS WILL RANGE FROM THE MID TO UPPER 60S ACROSS THE MTN
LOCATIONS...TO THE LOWER 70S IN THE SOUTHERN VALLEYS AND LOWER
SUSQ REGION.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
FRONTAL SYSTEM TO OUR WEST AND THE RIDGE OVER THE ATLANTIC WILL
SEND A DEEP PLUME OF MOISTURE WITH 2-3 SIGMA ABOVE NORMAL PW EAST
ACRS THE REGION. WHILE THE STRONGEST SWRLY LLVL FLOW WILL LIKELY
LIFT NE OF OUR AREA...THE FLOW WILL BE RATHER STRONG FOR EARLY
AUG.
CAPE VALUES ARE GOOD FOR SEVERE WEATHER BUT NOT OVERLY IMPRESSIVE.
BUT OVER 20KTS OF 1KM SHEAR WITH 1200 TO 1800JKG-1 IMPLIES DEEP
UPDRAFTS AND GOOD SHEAR. THIS SHOULD FAVOR THE DEVELOPMENT...MAINLY
FROM MID AFTERNOON INTO EVENING OF STRONG TO POTENTIAL SEVERE
THUNDERSTORMS...FAVORING MORE LINEAR SYSTEMS WITH POTENTIAL BOW
DEVELOPMENT. MOST GUIDANCE SHOWS STRONG LOW-LEVEL SHEAR WHICH WILL
REQUIRE MONITORING. MULTI-CELLULAR DAY LIKELY WITH BOWING SEGMENTS
HIGH PROBABILITY THINKING AT THIS TIME.
MOISTURE FLUX...OFTEN ALIGNS WELL WITH OUR BETTER SEVERE EVENTS
PEAKS 1800 UTC SUNDAY TO ABOUT 0000 UTC MONDAY. GOOD BET STRONG
STORMS FROM ABOUT 2 PM SUNDAY UNTIL 10 PM IN EAST.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
BY MONDAY MORNING...COLD FRONT WILL BE JUST SE OF CWA. WILL TAKE
SOME TIME TO CLEAR OUT RESIDUAL MOISTURE IN SOUTHEAST. BUT WITH
WESTERLY WINDS...DRIER AIR WILL EVENTUALLY WORK INTO THE BOUNDARY
LAYER IN THE SE. PW FALLS BELOW NORMAL STATE WIDE MONDAY.
CENTER OF SFC HIGH SETTLES OVER PA MON NIGHT/TUE KEEPING FORECAST
DRY. WEAK WAVE OVER SE U.S. SLIDES UP THE COAST FOR
WED/THU...NUDGING MOISTURE BACK INTO CWA. SO INTRODUCED SLIGHT
CHANCE FOR A TSTM WED/THU AS HUMIDITY BEGINS TO INCREASE. MORE
POTENT TROUGH APPROACHES IN NW FLOW FOR THU NIGHT-FRI NIGHT.
MODELS HANDLING THIS FEATURE WELL...THOUGH GFS TRIES TO LIFT
TROUGH NORTHWARD. EITHER WAY...CHANCE OF SHOWERS/TSTMS FITS THE
BILL BEFORE A MAINLY DRY WEEKEND.
TEMPERATURES WILL BE NEAR NORMAL TO START THE WEEK...THEN SLOWLY
RISE BACK ABOVE NORMAL FOR MIDWEEK. AS HUMIDITY INCREASES LATE
WEEK AHEAD OF APPROACHING TROUGH...TEMPS AGAIN GET A BIT MUGGY -
EVEN THOUGH THEY REMAIN JUST A FEW DEGREES ABOVE NORMAL.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
OTHER THAN SEG...NO FOG AT THIS TIME. WINDS TRYING TO PICK
UP A LITTLE...THUS CUT BACK ON FOG.
CONVECTION ACROSS THE NW MOUNTAINS IS FALLING APART.
ACTIVITY ACROSS OH SHOULD TURN SLIGHTLY MORE TO THE RIGHT...
BUT IS ALSO WEAKENING.
THUS MAINLY VFR CONDITIONS EXPECTED OVERNIGHT...EXCEPT FOR
A LITTLE FOG IN FEW LOCATIONS.
STILL EXPECT STRONG TO SEVERE STORMS BY LATE AFTERNOON...
INTO THIS EVENING...GIVEN TIMING OF FRONT AND DYNAMICS.
IMPROVING CONDITONS FROM LATER MONDAY INTO MID WEEK...
AS HIGH PRESSURE BUILDS INTO THE AREA.
OUTLOOK...
.MON...CHC OF A SHOWER OR STORM EARLY...THEN MAINLY VFR.
.TUE-THU...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT/RXR
LONG TERM...RXR
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
838 PM EDT MON AUG 6 2012
.SYNOPSIS...
A SLOW-MOVING COLD FRONT OVER TENNESSEE WILL DRIFT SLOWLY SOUTHEAST
OVER NIGHT AS MOIST TROPICAL AIR MOVES NORTH FROM FLORIDA. THIS
FRONT WILL STALL OVER THE AREA ON TUESDAY...AND SLOWLY DISSIPATE
LATER IN THE WEEK. ANOTHER COLD FRONT WILL APPROACH THE REGION FROM
THE WEST TOWARD THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TUESDAY/...
830 PM UPDATE...POPS WERE ADJUSTED PER THE LATEST RADAR TRENDS AND
BOUNDARY INTERACTION REGION. STILL EXPECT -SHRA/TSTMS FOR THE NEXT
FEW HRS ACROSS THE EXTREME NE GA...THE NRN UPSTATE AND INTO THE NC
PIEDMONT. ANY FLOODING LOOKS TO BE LESS OF A CONCERN WITH THE LINE
BECOMING BROKEN AND RAINFALL RATES ON A DOWNWARD TREND. A FEW STREAM
GAUGES HAVE RISEN VERY FAST THIS EVENING...ESP ACROSS SRN
MECKLENBURG COUNTY...BUT NOW ARE EITHER STEADY OR ON THE WAY DOWN.
BASED THE THUNDER POTENTIAL ON K/INDEX...WHICH GAVE ISOL TS WORDAGE
IN MOST PLACES AND GENERALLY AGREES WITH THE HRRR TSTM POTENTIAL.
TEMPS/TDS WERE ADJ TO MATCH INLINE WITH THE LATEST OBS.
430 PM UPDATE...UPDATED POPS AND SKY ATTEMPTING TO MATCH THE RADAR
TRENDS. STILL THINK CONVECTION WILL ENCOMPASS MOST AREAS OVER THE
NEXT FEW HOURS...WITH DRY REGIONS BEGINNING TO FILL IN. STRONG TO
SEVERE STORMS ARE BEING SUPPRESSED BY THE MOIST MID LEVELS AND
RELATIVELY LOW SFC/BASED INSTABILITY. EXPECT SUB/SEVERE
STORMS...WITH POTENTIALLY HEAVY DOWNPOURS AND LIGHTNING AS THE MAIN
THREATS OVER THE NEXT FEW HOURS.
AS OF 230 PM...SHOWER AND TSTM COVERAGE HAS BLOSSOMED OVER THE
MOUNTAIN RIDGES THIS AFTERNOON. COVERAGE SHOULD CONTINUE TO GROW AND
EXPAND EAST OF THE BLUE RIDGE AS A SHORTWAVE OBSERVED IN WATER VAPOR
IMAGERY OVER SE KY/NE TN MOVES ACROSS THE SRN APPALACHIANS AND THE
NRN TIER OF WRN NC. IN ADDITION...UPPER DIVERGENCE IN THE RIGHT
ENTRANCE REGION OF A 250 MB JETLET WILL GRADUALLY MOVE OVER THE AREA
TONIGHT...AND SRLY BL FLOW WILL PROVIDE SOME UPSLOPE FORCING AT
LOWER LEVELS. LIKELY TO CAT POPS WILL BE WARRANTED THIS AFTN INTO
TONIGHT. THE WARM AND WET PROFILES DO NOT APPEAR TO SUPPORT MUCH OF
A SEVERE TSTM THREAT...BUT ISOLD HYDRO PROBLEMS COULD DEVELOP WITH
ANY TRAINING OR BACKBUILDING NEAR THE HIGH TERRAIN.
THE MODELS AGREE FAIRLY WELL ON LINGERING H5 TROUGHINESS OVER THE
REGION TONIGHT THROUGH TUE...AS WELL AS PERSISTENT UPPER DIVERGENCE.
HOWEVER...THERE IS SOME SPREAD ON THE HANDLING OF THE 850 MB
CIRCULATION INITIALIZED OVER THE FL PANHANDLE THIS MORNING. THE NAM
MOVES THIS CIRCULATION SLOWLY NWD INTO NORTH CENTRAL GA BY LATE
TUE...WHILE THE GFS/ECM KEEP IT SUPPRESSED FARTHER S. LITTLE
DIFFERENCE IN SENSIBLE WEATHER SHOULD RESULT...HOWEVER...AS A S TO
SE UPSLOPE FLOW WILL CONTINUE INTO THE SRN APPALACHIANS THROUGH THE
NEAR TERM PERIOD. THE EAST SIDE OF THE SRN APPALACHIANS SHOULD BE
THE BEST FOCUS FOR HEAVY RAINFALL. HOWEVER...JUST ABOUT ANY LOCATION
COULD SEE ISOLATED FLOODING WITH SLOWLY MOVING OR TRAINING CELLS.
THE ENTIRE REGION WILL BE IN A +2 STANDARD DEVIATION ANOMALY ON GEFS
COMPUTED PRECIPITABLE WATER VALUES THROUGH TUE. SINCE PRECIPITATION
RATES HAVE NOT BEEN VERY HIGH SO FAR...AND 3 HR FFG IS GENERALLY 2
TO 4 INCHES MOST AREAS...WILL CONTINUE TO HOLD OFF ON ANY FFA AT
PRESENT. ONCE WE SEE WHICH BASINS GET SATURATED BY RAINFALL THIS
AFTN...A SHORT FUSE AND SMALLER FFA COULD BE ISSUED FARTHER INTO THE
EVENT.
WENT WITH A SMALLER DIURNAL RANGE ON MIN TEMPS TONIGHT/MAXES TUE
GIVEN THE ABUNDANT CLOUDS AND SOLID COVERAGE OF SHRA/TSRA. FOG COULD
BE A PROBLEM IN THE MTN VALLEYS TOWARD DAYBREAK.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
AS OF 140 PM MONDAY...THE SHORT TERM MODELS ARE IN GENERALLY GOOD
AGREEMENT IN SHIFTING THE AXIS OF THE UPPER JET AND MID-LEVEL TROUGH
TOWARD THE CENTRAL/EASTERN CAROLINAS BY WEDNESDAY...TAKING THE
TROPICAL MOISTURE FETCH ALONG WITH IT. THIS WILL LEAD TO A GRADUAL
WARMING TREND AND A RETURN TO CLIMATOLOGICAL POPS DURING THE PERIOD.
IN THE INTERIM...HIGH CHANCE TO LIKELY POPS CONTINUE ACROSS THE
FORECAST AREA INTO TUE NIGHT...WITH THE HIGHEST POPS FAVORED ACROSS
THE SOUTHEAST HALF OF THE CWA. THERE WILL BE A LINGERING HEAVY RAIN
THREAT INTO THE EVENING...ESP ACROSS THE SOUTHEAST ZONES.
BY WEDNESDAY...WITH THE DEEPER MOISTURE SHUNTED TO THE SOUTHEAST...
COVERAGE OF DIURNAL CONVECTION SHOULD BE LESS THAN WHAT WE HAVE SEEN
IN RECENT DAYS. HOWEVER...LINGERING LOW LEVEL MOISTURE AND WARMER
TEMPERATURES SHOULD ENSURE AT LEAST MODERATE DESTABILIZATION.
SCATTERED CONVECTION SHOULD THEREFORE DEVELOP OVER THE HIGH TERRAIN
BY MID-AFTERNOON...AND POSSIBLY ACROSS THE SOUTHERN ZONES NEARER THE
DEEP MOIST AXIS. ALL AREAS GET A CHANCE POP BY LATE AFTERNOON. WITH
THE DRYING OF THE MID-LEVELS...SEVERE CONVECTION CHANCES SHOULD
INCREASE...WITH A FEW PULSE STORMS POSSIBLE.
THURSDAY SHOULD BE RELATIVELY SIMILAR TO WEDNESDAY...WITH SCATTERED
CONVECTION DEVELOPING ACROSS THE AREA IN PERSISTENTLY UNSTABLE AIR
MASS. COVERAGE MAY INCREASE LATE IN THE DAY ACROSS THE WESTERN
ZONES...AS A MOIST WAA REGIME BECOMES ESTABLISHED OVER THE TENN
VALLEY IN RESPONSE TO THE APPROACH OF AN UNSEASONABLY STRONG STORM
SYSTEM.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 155 PM MONDAY...THE GLOBAL MODELS ARE IN VERY GOOD AGREEMENT
IN PUSHING A COLD FRONT ASSOCIATED WITH AFOREMENTIONED STORM SYSTEM
ACROSS THE AREA FRIDAY/FRIDAY NIGHT. DESPITE THE PRESENCE OF VERY
MOIST PROFILES...THERE MAY BE ENOUGH DEEP LAYER SHEAR AND
INSTABILITY TO SUPPORT AN ORGANIZED SEVERE WEATHER THREAT ON FRIDAY.
BY EARLY SATURDAY...THE GFS AND ECMWF ARE SIMILAR IN STALLING THE
FRONTAL BOUNDARY JUST SOUTH AND EAST OF THE AREA...WITH MUCH DRIER
AIR SWEEPING INTO THE REGION IN THE WAKE OF STRONG UPPER TROUGH. WE
HAVE OPTED TO LINGER SOME TOKEN SLIGHT CHANCE POPS ACROSS MOST OF
THE AREA (LOW CHANCE IN THE SOUTHEAST ZONES) UNTIL CONFIDENCE
INCREASES IN THE POSITION OF THE FRONTAL ZONE FOR THE WEEKEND.
(ALTHOUGH A PERFECT PROG OF BOTH THE GFS AND ECMWF WOULD SUGGEST A
DRY AND ACTUALLY RATHER PLEASANT MID-AUGUST WEEKEND).
BY MONDAY...WITH THE UPPER TROUGH PROGRESSING QUICKLY EAST OF THE
AREA...AND ADDITIONAL HEIGHT FALLS OCCURRING TO OUR WEST...THE
MEDIUM RANGE MODELS SUGGEST QUICK MODIFICATION OF THE CONTINENTAL
AIR MASS OVER THE AREA WILL OCCUR. INSTABILITY MAY BE HIGH ENOUGH
MONDAY AFTERNOON TO ALLOW A RETURN OF TYPICAL DIURNAL CONVECTION...
SO CHANCE POPS HAVE BEEN INTRODUCED FORN DAY 7. TEMPERATURES SHOULD
GENERALLY HOVER AROUND CLIMO THROUGH THE PERIOD.
&&
.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
AT KCLT...EXPECT CONVECTION TO BE MAINTAINED FOR THE NEXT FEW HRS
ACROSS THE TERMINAL AREA. PREVAILING WINDS ARE TRICKY WITH THE
COMPETING OUTFLOWS...BUT TRIED TO GO WITH A MEAN OF THE TWO MAIN
GUST FRONTS. SHOWERS AND THUNDER SHOULD DIMINISH OVERNIGHT...WITH
PERHAPS VICINITY -SHRA. THE COLUMN REMAINS MOIST AND MVFR CIGS ARE
PROBABLE. ALSO WENT WITH MVFR VSBY EARLY MORNING WITH ALL THE SFC
BASED SATURATION...COULD GO IFR. ANOTHER ROUND OF THUNDER TOMORROW
AFTERNOON AFFECTING THE TERMINAL.
ELSEWHERE...ONGOING CONVECTION WILL CONTINUE AT KGSP AND KGMU OVER
THE NEXT FEW HRS. A GRADUAL DIMINISHING WILL OCCUR AFT MIDNIGHT AND
EXPECT CIGS TO LOWER INTO THE MVFR/IFR RANGE AT ALL TERMINALS WITH
THE VERY MOIST LLVL ATMOS. LOW MVFR VSBY WILL ALSO BE A CONCERN
ACROSS THE NON/MTNS AND IFR ACROSS THE MTN VALLEYS BY DAYBREAK.
SHOWERS AND THUNDERSTORMS WILL AFFECT THE TAF SITES AGAIN TOMORROW
AFTERNOON AS THE UPPER S/W SLOWLY CROSSES OVERHEAD AND THE SFC
BOUNDARY STALLS.
OUTLOOK...DEEP MOISTURE WILL REMAIN IN PLACE ACROSS THE REGION
THROUGH TUE NIGHT...WITH SOLID COVERAGE OF SHRA/TSRA AND ASSOCIATED
RESTRICTIONS. WEAK DRYING IS POSSIBLE WED/EARLY THU...BUT THEN
MOISTURE POOLS AGAIN AHEAD OF AN APPROACHING COLD THROUGH FRI.
EXPECT A WEEK OF VERY UNSETTLED WEATHER.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...PAT
NEAR TERM...HG/SBK
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...SBK
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
1229 AM CDT SUN AUG 5 2012
.PREV DISCUSSION... /ISSUED 922 PM CDT SAT AUG 4 2012/
DISCUSSION...WATER VAPOR SATELLITE/UPPER AIR PROFILER/WSR-88D VAD
WIND PROFILES INDICATE A SHORTWAVE ACROSS SOUTHWEST MISSOURI THIS
EVENING. THIS IS RESULTING IN NUMEROUS SHOWERS AND THUNDERSTORMS
ACROSS SOUTHWEST AND SOUTH CENTRAL MISSOURI. TEMPERATURES AS OF 8
PM CDT ARE IN THE 80S AT MOST LOCATIONS. SHOWER AND THUNDERSTORM
CHANCES ALONG WITH THE POTENTIAL FOR STRONG TO PERHAPS SEVERE
THUNDERSTORMS OVERNIGHT ARE THE PREDOMINANT CONCERNS IN THIS
EVENING/S UPDATE.
LATEST SHORT TERM RUC MODEL ALONG WITH CONVECTIVE TRENDS SUGGEST A
POTENTIAL FOR THIS ACTIVITY TO BEGIN PROPAGATING EAST SOUTHEAST
INTO AT LEAST THE NORTHWEST ONE THIRD OF THE MID SOUTH THIS
EVENING. HAVE DISCOUNTED THE 00Z WRF THIS EVENING THUS FAR AS IT HAS
EXPERIENCED SOME DIFFICULTY HANDLING THE CURRENT CONVECTIVE
ACTIVITY OVER SOUTHERN MISSOURI. RADAR TRENDS INDICATE SOME
WEAKENING HAS BEGUN TO OCCUR WITH THIS COMPLEX. AN ISOLATED STRONG
TO PERHAPS SEVERE THUNDERSTORM MAY BE POSSIBLE ACROSS PORTIONS OF
NORTHEAST ARKANSAS AND THE MISSOURI BOOTHEEL IF IT BEGINS TO DROP
INTO THE FORECAST AREA IN THE NEXT HOUR OR TWO.
WILL UPDATE GRIDS TO ADJUST TIMING OF SHOWER/THUNDERSTORM CHANCES
BASED ON LATEST TRENDS AND ADJUST ALL OTHER ELEMENTS AS NEEDED.
UPDATED GRIDS WILL BE AVAILABLE SHORTLY.
CJC
&&
.PREV DISCUSSION... /ISSUED 333 PM CDT SAT AUG 4 2012/
DISCUSSION...
FINALLY WILL SEE A PATTERN SHIFT OVER THE NEXT WEEK AS AN UPPER TROF
MOVES OVER THE EASTERN UNITED STATES. EXPECT TWO COLD FRONTS TO MOVE
THROUGH THE REGION WHICH SHOULD FINALLY BRING AN END TO THE HEAT
WAVE.
TONIGHT...A COLD FRONT THAT CURRENTLY STRETCHES FROM CHICAGO
ILLINOIS TO ST JOSEPH MISSOURI WILL SINK SOUTH. EXPECT A LINE OF
SHOWERS AND THUNDERSTORMS TO DEVELOP ALONG THE FRONT THIS EVENING.
SOME STORMS MAY BECOME SEVERE ALONG THE LINE. EXPECT THE LINE TO
BEGIN MOVING INTO THE MIDSOUTH SHORTLY AFTER MIDNIGHT. THE LINE WILL
LIKELY BE DYING BY THIS POINT BUT STILL CAN/T RULE OUT A FEW STRONG
TO SEVERE STORMS. OTHERWISE...THIS EVENING SHOULD BE RELATIVELY
QUIET WITH THE EXCEPTION OF A FEW STORMS ACROSS PORTIONS OF
NORTHEAST MISSISSIPPI THAT ARE DEVELOPING IN RESPONSE TO A SHORTWAVE
MOVING THROUGH THE REGION. HOWEVER THESE STORMS SHOULD BE
SHORT-LIVED AS THE SHORTWAVE IS PUSHING EAST OF THE AREA. LOWS WILL
BE IN THE MID TO UPPER 70S.
SUNDAY...COLD FRONT MOVES INTO THE MIDSOUTH. EXPECT NUMEROUS SHOWERS
AND THUNDERSTORMS TO DEVELOP IN RESPONSE TO THE FRONT INTERACTING
WITH DAYTIME HEATING. EXPECT SOME STORMS TO BECOME SEVERE WITH LARGE
HAIL AND DAMAGING WINDS. THE BIG QUESTION IS HOW MUCH ACTIVITY FROM
THE OVERNIGHT THUNDERSTORMS WILL STILL BE AROUND AT 7 AM. THIS WILL
PLAY A HUGE ROLE ON LATER THUNDERSTORM DEVELOPMENT AS WELL AS
TEMPERATURES. CLOUD COVER FROM SOME SHOWERS THIS MORNING...REALLY
PREVENTED DEVELOPMENT ACROSS WEST TENNESSEE. CLOUDS ALSO KEPT
TEMPERATURES DOWN ACROSS WESTERN KENTUCKY. DEWPOINTS HAVE BEEN
IN THE MID TO UPPER 70S AND EXPECT SIMILAR CONDITIONS TOMORROW. WILL
FORECAST HIGHS IN THE LOWER TO MID 90S. THESE TEMPERATURES COMBINED
WITH THE DEWPOINTS WILL PRODUCE HEAT INDICES ABOVE 105 DEGREES. BUT
WITH SO MUCH UNCERTAINTY WILL HOLD OFF ON ISSUING A HEAT ADVISORY.
WILL LET MIDNIGHT SHIFT SEE HOW OVERNIGHT CONVECTION EVOLVES TO MAKE
FINAL CALL.
SUNDAY NIGHT INTO MONDAY...FRONT WILL CONTINUE TO SINK SOUTH ACROSS
THE CWA. BEST CHANCES FOR SHOWERS AND THUNDERSTORMS WILL BE ACROSS
NORTH MISSISSIPPI. MODELS ARE NOT AS QUICK TO PUSH DRIER AIR INTO
THE CWA BEHIND THE FRONT. EXPECT LOWS TO STILL BE IN THE LOWER TO
MID 70S WITH HIGHS ON MONDAY REMAINING IN THE LOWER TO MID 90S.
MONDAY NIGHT THROUGH THURSDAY...SOME DRIER AIR DOES MOVE INTO THE
MIDSOUTH. ALL MODELS INDICATING DIURNAL CONVECTION DEVELOPING EACH
AFTERNOON MAINLY ACROSS SOUTHEASTERN PART OF THE CWA WHERE THE
DEWPOINTS REMAIN HIGHER. LOWS WILL RANGE FROM THE UPPER 60S TO MID
70S WITH HIGHS IN THE LOWER TO MID 90S.
THURSDAY NIGHT THROUGH FRIDAY NIGHT...A SECOND COLD FRONT WILL SINK
SOUTH AS A BROAD UPPER TROF MOVES OVER THE EASTERN UNITED STATES.
EXPECT CHANCES FOR SHOWERS AND THUNDERSTORMS TO EXPAND OVER THE
ENTIRE CWA. HIGH TEMPERATURES ON FRIDAY MAY BE A TAD COOLER DUE TO
CLOUD COVER AND THUNDERSTORMS.
SATURDAY...SFC HIGH PRESSURE WILL MOVE INTO THE REGION. COOLER AND
DRIER AIR WILL FILTER INTO THE REGION. EXPECT PLEASANT CONDITIONS AS
A RESULT WITH HIGHS IN THE UPPER 80S FOR THE MOST PART.
KRM
&&
.AVIATION...
06Z TAF SET
LINE OF DEVELOPING TSRA MAY IMPACT JBR WITHIN THE NEXT HOUR OR SO.
NOT CONFIDENT THAT TS WILL CONTINUE TO DEVELOP AND IMPACT MEM OR
MKL LATER IN THE NIGHT...BUT A FEW SHOWERS ARE DEVELOPING. WINDS
WILL REMAIN SSW OVERNIGHT BETWEEN 5 AND 10 KNOTS. A COLD FRONT
WILL APPROACH TOMORROW STALLING ACROSS NORTH MISSISSIPPI INTO
SOUTHEAST ARKANSAS. SHOWERS AND THUNDERSTORMS WILL INCREASE IN
COVERAGE THROUGHOUT THE DAY SUNDAY...CONTINUING INTO SUNDAY NIGHT.
INCLUDED VCTS AT ALL SITES SUNDAY...WILL ADD PREVAILING TS WHEN
STORMS DEVELOP AND THERE IS SOMETHING TO TIME BETTER. IFR VIS AND
WIND WILL BE POSSIBLE AT LOCATIONS IMPACTED BY THUNDERSTORMS.
WINDS WILL SHIFT FROM THE NORTH DURING THE LATE AFTERNOON HOURS AT
JBR...MKL AND MEM.
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 94 75 92 73 / 60 60 20 10
MKL 90 71 90 67 / 60 60 20 10
JBR 92 70 93 69 / 60 30 10 10
TUP 93 75 91 72 / 60 60 50 20
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
956 PM CDT MON AUG 6 2012
.DISCUSSION...UPDATED WORDING IN THE ZONES TO REMOVE MENTION OF
SHOWERS THIS EVENING. WARMED OVERNIGHT LOWS BY A DEGREE OR TWO
WITH LINGERING HIGH CLOUDS MOVING IN FROM THE EAST. MOISTURE WILL
REMAIN ABUNDANT TONIGHT WITH PWATS JUST BELOW 2 INCHES...WHICH
SHOULD AIDE IN ISOLATED SHOWER DEVELOPMENT OVER THE GULF WATERS
LATE TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 639 PM CDT MON AUG 6 2012/
DISCUSSION...UPDATE FOR 00Z AVIATION BELOW.
AVIATION...VFR CONDS THIS EVE AND MOST LOCATIONS OVRNGT.
EXCEPTION MAY BY SOME PATCHY BR INLAND NEAR A NQI-BEA-VCT LINE
10Z-14Z. WINDS DECREASING AFTER SUNSET...BCMG LGT/VRB MANY
LOCATIONS OVRNGT.
PREV DISCUSSION... /ISSUED 305 PM CDT MON AUG 6 2012/
SHORT TERM (TONIGHT THROUGH TUESDAY NIGHT)...CONVECTION THIS
AFTERNOON HAS DIMINISH AS THE SEA-BREEZE MOVES INLAND. MAIN
THINKING IS THAT THE BEST DYNAMICS REMAIN TO THE SOUTH WHERE A
STRONGER VORTICITY MAX SHOWS UP IN THE RUC ANALYSIS...AND BIT
STRONGER CAP IS HOLDING ON ACROSS OUR REGION. WITH THE LOSS OF
HEATING LATE THIS EVENING...PRECIPITATION WILL REMAIN LOW AND HAVE
KEPT MENTION OUT OF THE FORECAST. DECENT MOISTURE IN PLACE
EXPECTED TO STAY AROUND FOR TOMORROW TO KEEP SLIGHT CHANCE OF
PRECIPITATION...BEGINNING OVER THE COASTAL WATERS TUESDAY MORNING
THEN AFTERNOON CONVECTION AGAIN FOR THE AFTERNOON HOURS. COULD SEE
A BIT OF LOWER VISIBILITIES WILL BE POSSIBLE JUST BEFORE SUNRISE
GIVEN THE LIGHT WINDS...HIGH DEW POINT VALUES AND GENERALLY CLEAR
SKIES. HOWEVER...CONFIDENCE REMAINS LOW ON FOG DEVELOPMENT
OVERNIGHT. AFTERNOON TEMPERATURES WILL ONCE AGAIN RUN ABOVE
GUIDANCE/SEASONAL AVERAGES. OVERALL...A PERSISTENT FORECAST FROM
WHAT WE HAVE SEE THE PAST FEW DAYS...JUST A BIT LESS IN THE WAY OF
CONVECTION WITH LACK OF MID/UPPER LEVEL SUPPORT.
LONG TERM (WEDNESDAY THROUGH MONDAY)...CONCUR WITH THE
DETERMINISTIC GFS/ECMWF AND GFS ENSEMBLE MEAN THAT THE UPPER RIDGE
WILL CONTINUE TO MOVE TOWARD THE NW BEFORE BECOMING QUASI-
STATIONARY. SUFFICIENT MOISTURE/INSTABILITY WILL CONTRIBUTE TO ISOLD
CONVECTION PRIMARILY OVER THE NERN SECTIONS/ADJACENT MSA
WEDNESDAY/THURSDAY. THE FOREGOING MODELS PROG AN UPPER DISTURBANCE
TO MOVE ACRS THE CNTRL/NRN PLAINS WEDNESDAY/THURSDAY WHICH WILL
CONTRIBUTE TO A WEAK FRONTAL BOUNDARY WHICH MAY ENTER CNTRL/SRN TX
FRIDAY/SATURDAY (ALONG WITH ASSOCIATED HIGH PW VALUES OWING TO MSTR
CONVERGENCE.) FURTHER...BASED ON THE CURRENT ERNESTO FCST TRACK...
THE NRN EDGE OF COPIOUS MSTR FROM ERNESTO EXPECTED TO ENTER THE
CWA/MSA COMMENCING LATE THURSDAY. THUS WILL MAINTAIN AT LEAST ISOLD
CONVECTION FRIDAY/SATURDAY. NOT CONFIDENCE ENOUGH TO FCST PCPN
SUNDAY/MONDAY. NO SIGNIFICANT CHANGE TO TEMPS DRG THE PERIOD EXCEPT
FOR SLIGHT DECREASE IN RESPONSE TO ERNESTO MSTR. ANTICIPATE MAX HEAT
INDEX VALUES AROUND 105F DRG THE PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 75 96 77 95 75 / 10 20 10 10 10
VICTORIA 74 95 75 95 74 / 10 20 10 20 10
LAREDO 78 102 79 102 79 / 10 10 10 10 10
ALICE 74 100 74 99 74 / 10 20 10 10 10
ROCKPORT 79 91 79 89 78 / 20 20 10 20 10
COTULLA 74 101 75 101 75 / 10 10 10 10 10
KINGSVILLE 75 98 76 97 75 / 10 20 10 10 10
NAVY CORPUS 79 90 80 88 80 / 10 20 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
CB/85...UPDATE
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
953 PM CDT MON AUG 6 2012
.UPDATE...
WEAKENING CONVECTION HAS MOVED INTO THE NORTHEAST PORTION OF THE
CWA NEAR THROCKMORTON AND WILL CONTINUE ITS DOWNWARD TREND AS IT
MOVES SSW. ADDITIONAL...MORE IMPRESSIVE...STORMS EXIST ALONG THE
I-35 CORRIDOR FORMING JUST NORTH OF THE RED RIVER NEAR THE
INTERSECTION OF THE LOW LEVEL JET AND A QUASI-STATIONARY SURFACE
FRONT. HOWEVER...THESE STORMS WILL MOVE GENERALLY SOUTH AND SHOULD
REMAIN TO THE EAST OF THE CWA. THE HRRR MAINTAINS THE CONVECTION
OVER THROCKMORTON COUNTY WELL INTO THE NORTHERN CONCHO VALLEY BUT
OTHER 3 KM WRF VARIETIES WEAKEN THIS CONVECTION OVER THE NEXT 1-2
HOURS. GIVEN THE PERSISTENCE OF LAST NIGHTS ACTIVITY...I HAVE
KEPT MENTION OF THUNDERSTORMS FOR THE BIG COUNTRY THROUGH 09Z WITH
DRY CONDITIONS THEREAFTER. I ALSO LOWERED MIN TEMPS JUST A BIT...
SHADING CLOSER TO WHAT WAS OBSERVED THIS MORNING WITH A SLIGHT
MODEL BLEND BUILT IN. GENERALLY LOW/MID 70S ARE EXPECTED ACROSS
THE CWA.
JOHNSON
&&
.PREV DISCUSSION... /ISSUED 617 PM CDT MON AUG 6 2012/
DISCUSSION...
SEE 00Z AVIATION DISCUSSION BELOW.
AVIATION...
SCATTERED THUNDERSTORMS HAVE DEVELOPED ACROSS NORTHERN
TEXAS AND SOUTHWEST OKLAHOMA...NORTH AND EAST OF OUR AREA. LOOKS
LIKE THE STORMS WILL REMAIN OUT OF WEST CENTRAL TEXAS THIS
EVENING...WITH MOST OF THIS ACTIVITY DISSIPATING BY 03Z TUE. WILL
GO WITH VFR CONDITIONS AT THE TERMINALS THE NEXT 24 HOURS.
21
PREV DISCUSSION... /ISSUED 350 PM CDT MON AUG 6 2012/
SHORT TERM...
LITTLE CHANGE TO FORECAST REASONING THE NEXT 24 HOURS. WEST
CENTRAL TEXAS WILL REMAIN ON THE EASTERN PERIPHERY OF THE UPPER
HIGH THAT WILL BE CENTERED OVER THE FOUR CORNERS REGION THE REST
OF THIS WEEK. WATER VAPOR IMAGERY ALREADY SHOWING BETTER MID
LEVEL MOISTURE ACROSS ACROSS THE AREA COMPARED TO THE PAST COUPLE
OF DAYS. THE INCREASE IN MOISTURE COUPLED WITH STRONG DAYTIME
HEATING WILL ALLOW FOR ISOLATED TO WIDELY SCATTERED SHOWERS AND
THUNDERSTORMS LATE THIS AFTERNOON AND EVENING AND AGAIN TUESDAY
AFTERNOON. THE BEST CHANCE FOR STORMS THROUGH THIS EVENING WILL
BE ACROSS THE BIG COUNTRY WHERE 20 POPS WERE ADDED.
OTHERWISE...WENT WITH ISOLATED WORDING ELSEWHERE THROUGH THE
EVENING HOURS.
SIMILAR SCENARIO FOR TUESDAY WITH BEST CHANCE FOR ISOLATED
CONVECTION ACROSS THE BIG COUNTRY TUESDAY AFTERNOON. TEMPERATURES
ON TUESDAY WILL BE SIMILAR TO TODAY WITH AFTERNOON HIGHS
GENERALLY A COUPLE OF DEGREES EITHER SIDE OF THE CENTURY MARK.
LONG TERM...
WEST CENTRAL TEXAS WILL BE THE EASTERN SIDE OF THE UPPER RIDGE
INTO NEXT WEEKEND...WITH NORTHERLY FLOW ALOFT. ISOLATED
THUNDERSTORMS WILL CONTINUE TO BE POSSIBLE...WEDNESDAY INTO
THURSDAY...BUT BEST CHANCE OF A THUNDERSTORM WILL BE WEDNESDAY
NIGHT AS GFS MODEL BRINGS A WEAK COLD FRONT THROUGH THE REGION.
MAY STAY 2-3 DEGREES LESS HOT THURSDAY INTO SATURDAY...BUT UPPER
RIDGE/850 MB THERMAL TROUGH STRENGTHENS AGAIN SUNDAY INTO EARLY
NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 76 101 76 102 75 / 10 20 10 20 20
SAN ANGELO 74 102 75 102 73 / 5 10 10 20 20
JUNCTION 72 98 73 102 74 / 5 10 10 10 20
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
25
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
639 PM CDT MON AUG 6 2012
.DISCUSSION...UPDATE FOR 00Z AVIATION BELOW.
&&
.AVIATION...VFR CONDS THIS EVE AND MOST LOCATIONS OVRNGT.
EXCEPTION MAY BY SOME PATCHY BR INLAND NEAR A NQI-BEA-VCT LINE
10Z-14Z. WINDS DECREASING AFTER SUNSET...BCMG LGT/VRB MANY
LOCATIONS OVRNGT.
&&
.PREV DISCUSSION... /ISSUED 305 PM CDT MON AUG 6 2012/
SHORT TERM (TONIGHT THROUGH TUESDAY NIGHT)...CONVECTION THIS
AFTERNOON HAS DIMINISH AS THE SEA-BREEZE MOVES INLAND. MAIN
THINKING IS THAT THE BEST DYNAMICS REMAIN TO THE SOUTH WHERE A
STRONGER VORTICITY MAX SHOWS UP IN THE RUC ANALYSIS...AND BIT
STRONGER CAP IS HOLDING ON ACROSS OUR REGION. WITH THE LOSS OF
HEATING LATE THIS EVENING...PRECIPITATION WILL REMAIN LOW AND HAVE
KEPT MENTION OUT OF THE FORECAST. DECENT MOISTURE IN PLACE
EXPECTED TO STAY AROUND FOR TOMORROW TO KEEP SLIGHT CHANCE OF
PRECIPITATION...BEGINNING OVER THE COASTAL WATERS TUESDAY MORNING
THEN AFTERNOON CONVECTION AGAIN FOR THE AFTERNOON HOURS. COULD SEE
A BIT OF LOWER VISIBILITIES WILL BE POSSIBLE JUST BEFORE SUNRISE
GIVEN THE LIGHT WINDS...HIGH DEW POINT VALUES AND GENERALLY CLEAR
SKIES. HOWEVER...CONFIDENCE REMAINS LOW ON FOG DEVELOPMENT
OVERNIGHT. AFTERNOON TEMPERATURES WILL ONCE AGAIN RUN ABOVE
GUIDANCE/SEASONAL AVERAGES. OVERALL...A PERSISTENT FORECAST FROM
WHAT WE HAVE SEE THE PAST FEW DAYS...JUST A BIT LESS IN THE WAY OF
CONVECTION WITH LACK OF MID/UPPER LEVEL SUPPORT.
LONG TERM (WEDNESDAY THROUGH MONDAY)...CONCUR WITH THE
DETERMINISTIC GFS/ECMWF AND GFS ENSEMBLE MEAN THAT THE UPPER RIDGE
WILL CONTINUE TO MOVE TOWARD THE NW BEFORE BECOMING QUASI-
STATIONARY. SUFFICIENT MOISTURE/INSTABILITY WILL CONTRIBUTE TO ISOLD
CONVECTION PRIMARILY OVER THE NERN SECTIONS/ADJACENT MSA
WEDNESDAY/THURSDAY. THE FOREGOING MODELS PROG AN UPPER DISTURBANCE
TO MOVE ACRS THE CNTRL/NRN PLAINS WEDNESDAY/THURSDAY WHICH WILL
CONTRIBUTE TO A WEAK FRONTAL BOUNDARY WHICH MAY ENTER CNTRL/SRN TX
FRIDAY/SATURDAY (ALONG WITH ASSOCIATED HIGH PW VALUES OWING TO MSTR
CONVERGENCE.) FURTHER...BASED ON THE CURRENT ERNESTO FCST TRACK...
THE NRN EDGE OF COPIOUS MSTR FROM ERNESTO EXPECTED TO ENTER THE
CWA/MSA COMMENCING LATE THURSDAY. THUS WILL MAINTAIN AT LEAST ISOLD
CONVECTION FRIDAY/SATURDAY. NOT CONFIDENCE ENOUGH TO FCST PCPN
SUNDAY/MONDAY. NO SIGNIFICANT CHANGE TO TEMPS DRG THE PERIOD EXCEPT
FOR SLIGHT DECREASE IN RESPONSE TO ERNESTO MSTR. ANTICIPATE MAX HEAT
INDEX VALUES AROUND 105F DRG THE PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 75 96 77 95 75 / 10 20 10 10 10
VICTORIA 73 95 75 95 74 / 10 20 10 20 10
LAREDO 78 102 79 102 79 / 10 10 10 10 10
ALICE 74 100 74 99 74 / 10 20 10 10 10
ROCKPORT 79 91 79 89 78 / 20 20 10 20 10
COTULLA 74 101 75 101 75 / 10 10 10 10 10
KINGSVILLE 74 98 76 97 75 / 10 20 10 10 10
NAVY CORPUS 79 90 80 88 80 / 10 20 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
JR/76...AVIATION
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1100 PM CDT MON AUG 6 2012
.SHORT TERM...TONIGHT
935 PM CDT MON AUG 6 2012
HAVE ELECTED TO HOLD ONTO THE SMALL SHOWER/STORM CHANCES
OVERNIGHT...ALTHOUGH CONFIDENCE ISN/T HIGH. 00Z SOUNDINGS FROM
MPX/GRB/DVN ALL VERY DRY. HOWEVER...RAP CONTINUES TO POINT TO SOME
925-850 MB MOISTURE TRANSPORT...WEAK FRONTOGENETIC FORCING...SOME
THETA-E ADVECTION...ALONG WITH AROUND 1000 J/KG OF MLCAPE THROUGH AT
LEAST 09Z. WEAK IMPULSE ALOFT ALSO SPINNING SOUTHEAST ACROSS THE
REGION...PER LATEST WATERVAPOR IMAGERY. NARY A CLOUD OTHERWISE ON
THE FOG/STRATUS PRODUCT...EXCEPT ASSOCIATED WITH A FRONTAL BOUNDARY
IN NORTHERN MN/THE UP OF MICH. THIS FRONT WILL SLIDE SOUTHWARD
ACROSS THE REGION...SLIPPING SOUTH OF THE FORECAST AREA PROBABLY
BETWEEN 12-15Z. RADAR DID DETECT ONE POSSIBLE SHOWER NEAR BLACK
RIVER FALLS THIS EVENING...BUT IT WAS ASSOCIATED WITH 11 KFT BASES.
SO ALL IN ALL...ENOUGH FORCING MECHANISMS TO CONTINUE THE SMALL
POPS...WITH LACK OF SATURATION THE PRIMARY LIMITING FACTOR.
WITH CLEARER SKIES TONIGHT AND LIGHT SFC WINDS...COULD HAVE SOME
RIVER VALLEY FOG. SETUP NOT AS GOOD AS THIS MORNING.
.LONG TERM...FRIDAY THROUGH MONDAY
305 PM CDT MON AUG 6 2012
NORTH TO NORTHWEST FLOW WILL CONTINUE ACROSS THE AREA THROUGH THE
PERIOD. EXITING TROUGH WILL CONTINUE TO DEEPEN OVER THE GREAT LAKES
AND MOVE EASTWARD FRIDAY INTO SATURDAY...WHILE HIGH PRESSURE
DOMINATES THE WEATHER FOR THE LOCAL AREA. THE HIGH WILL SLIDE OFF TO
THE EAST SATURDAY NIGHT...ALLOWING FOR MOISTURE RETURN ON ITS
BACKSIDE AHEAD OF THE NEXT SHORTWAVE/SURFACE TROUGH. GFS MUCH DEEPER
WITH THIS FEATURE...WHILE 06.12Z ECMWF IS MUCH WEAKER AND EVEN DRY
IN ITS QPF FIELDS. SYSTEM THEM DROPS SOUTH WITH QUIET WEATHER
EXPECTED INTO MONDAY. WITH THE NORTHWEST FLOW...TEMPERATURES WILL BE
RATHER PLEASANT AVERAGING AT OR BELOW NORMAL.
&&
.AVIATION...
1100 PM CDT MON AUG 6 2012
VERY DRY 00Z SOUNDINGS FROM MSP/GRB/DVN...WITH LITTLE TO NO CLOUDS
INDICATED IN THE VICINITY FROM LATEST CLOUD/STRATUS SATELLITE
IMAGERY. OTHER THEN A FEW MID LEVEL CLOUDS...THE BULK OF WHAT WAS
OUT THERE WAS CONFINED AROUND A FRONTAL BOUNDARY ACROSS NORTHEAST
MN/UP OF MICH. RAP STILL ADAMANT WITH ABOUT 1000 J/KG OF MLCAPE
ACROSS THE AREA FOR MUCH OF THE OVERNIGHT...WITH SOME FRONTOGENETIC
FORCING...AND A GOOD PUSH OF 925 MB MOISTURE ADVECTION. THAT FRONT
TO THE NORTH WILL DROP SOUTH OVERNIGHT...LIKELY SLIPPING SOUTH OF
KRST/KLSE AROUND 12Z...AND THERE IS A WEAK SHORTWAVE MAKING ITS WAY
SOUTHEAST ACROSS THE REGION. SO...THERE ARE FORCING MECHANISMS...BUT
SATURATION PER THE SOUNDINGS AND FORECAST RH FIELDS/BUFKIT SOUNDINGS
PRETTY MEAGER. IF SHRA/TS WOULD DEVELOP...BASES WOULD PROBABLY BE
AOA 8 KFT. CONFIDENCE LOW ENOUGH THAT I HAVE REMOVED THE VCSH FROM
THE TAFS. IF THEY DO DEVELOP...DON/T BELIEVE THERE WOULD BE ANY
CIG/VSBY IMPACT. PERHAPS SOME GUSTINESS.
AS FOR VSBY...WITH SKIES MORE SKC/SCT OVERNIGHT AND THE SFC WIND
FIELD VRB/CALM ACROSS MUCH OF THE AREA...RIVER VALLEY FOG IS A
CONCERN. T/TD SPREAD THE SAME AS YESTERDAY AT 03Z AT KLSE...8
DEGREES. WINDS AREN/T PROGGED TO BE AS LIGHT OFF THE SFC
THOUGH...WITH RAP/NAM12 BUFKIT SOUNDINGS AROUND 10-15 KTS BY 200-400
HUNDRED FEET. TDS HAVE CONTINUED TO CLIMB THIS EVENING...AND MIGHT
GET ANOTHER 1-2 DEGREE RISE. THIS COULD BE ALL THAT IS NEEDED FOR
IFR FG AT KLSE. HAVE DECIDE TO TREND THE FORECAST MUCH LIKE MONDAY
MORNING...WITH 2SM...AND BCFG TO COVER THE PATCHES OF MORE DENSE
FOG. CONDITIONS WILL BE MONITORED AND ADJUSTMENTS MADE AS A
NEEDED.
WITH THE FRONT SLIDING THROUGH EARLY TUE MORNING...WINDS WILL SWITCH
TO THE NORTHWEST. HIGH PRESSURE WILL FOLLOW IN ITS WAKE...WITH QUIET
VFR CONDITIONS THEN INTO TUE NIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
305 PM CDT MON AUG 6 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RIECK
LONG TERM....JLR
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
935 PM CDT MON AUG 6 2012
.SHORT TERM...TONIGHT
935 PM CDT MON AUG 6 2012
HAVE ELECTED TO HOLD ONTO THE SMALL SHOWER/STORM CHANCES
OVERNIGHT...ALTHOUGH CONFIDENCE ISN/T HIGH. 00Z SOUNDINGS FROM
MPX/GRB/DVN ALL VERY DRY. HOWEVER...RAP CONTINUES TO POINT TO SOME
925-850 MB MOISTURE TRANSPORT...WEAK FRONTOGENETIC FORCING...SOME
THETA-E ADVECTION...ALONG WITH AROUND 1000 J/KG OF MLCAPE THROUGH AT
LEAST 09Z. WEAK IMPULSE ALOFT ALSO SPINNING SOUTHEAST ACROSS THE
REGION...PER LATEST WATERVAPOR IMAGERY. NARY A CLOUD OTHERWISE ON
THE FOG/STRATUS PRODUCT...EXCEPT ASSOCIATED WITH A FRONTAL BOUNDARY
IN NORTHERN MN/THE UP OF MICH. THIS FRONT WILL SLIDE SOUTHWARD
ACROSS THE REGION...SLIPPING SOUTH OF THE FORECAST AREA PROBABLY
BETWEEN 12-15Z. RADAR DID DETECT ONE POSSIBLE SHOWER NEAR BLACK
RIVER FALLS THIS EVENING...BUT IT WAS ASSOCIATED WITH 11 KFT BASES.
SO ALL IN ALL...ENOUGH FORCING MECHANISMS TO CONTINUE THE SMALL
POPS...WITH LACK OF SATURATION THE PRIMARY LIMITING FACTOR.
WITH CLEARER SKIES TONIGHT AND LIGHT SFC WINDS...COULD HAVE SOME
RIVER VALLEY FOG. SETUP NOT AS GOOD AS THIS MORNING.
.LONG TERM...FRIDAY THROUGH MONDAY
305 PM CDT MON AUG 6 2012
NORTH TO NORTHWEST FLOW WILL CONTINUE ACROSS THE AREA THROUGH THE
PERIOD. EXITING TROUGH WILL CONTINUE TO DEEPEN OVER THE GREAT LAKES
AND MOVE EASTWARD FRIDAY INTO SATURDAY...WHILE HIGH PRESSURE
DOMINATES THE WEATHER FOR THE LOCAL AREA. THE HIGH WILL SLIDE OFF TO
THE EAST SATURDAY NIGHT...ALLOWING FOR MOISTURE RETURN ON ITS
BACKSIDE AHEAD OF THE NEXT SHORTWAVE/SURFACE TROUGH. GFS MUCH DEEPER
WITH THIS FEATURE...WHILE 06.12Z ECMWF IS MUCH WEAKER AND EVEN DRY
IN ITS QPF FIELDS. SYSTEM THEM DROPS SOUTH WITH QUIET WEATHER
EXPECTED INTO MONDAY. WITH THE NORTHWEST FLOW...TEMPERATURES WILL BE
RATHER PLEASANT AVERAGING AT OR BELOW NORMAL.
&&
.AVIATION...
600 PM CDT MON AUG 6 2012
THERE APPEARS TO BE TWO FOCUSES FOR AN ISOLATED SHRA/TS TONIGHT.
FIRST IS NORTH WITH A SFC FRONT/TROUGH MOVING SOUTHWARD ACROSS THE
REGION. SOME FRONTOGENETIC FORCING AND WEAK MLCAPE AROUND THE
BOUNDARY. DECENT PUSH OF 850 MB MOISTURE VIA THE RAP. THE HRRR AND
NAM12 POP SOME CONVECTION ALONG THE BOUNDARY...BUT ITS MOSTLY
CONFINED ACROSS NORTHERN WI TONIGHT.
THE OTHER FOCUS IS ANOTHER SFC BOUNDARY WITH ACCOMPANYING LOW AROUND
THE IA/MN BORDER. SOME 900-700 MB FRONTOGENETIC FORCING INDICATED IN
THE RAP...ALONG WITH MLCAPES UPWARDS OF 3000 J/KG THIS EVENING. THE
HRRR AND NAM12 ALSO DEVELOP SOME ISOLATED SHRA/TS DUE TO THIS
FORCING...AND THIS ACTIVITY WOULD HAVE THE BETTER CHANCE OF
IMPACTING KRST/KLSE. IT SHOULD BE NOTED THAT MOST OF THE SATURATION
INDICATED FOR THE FORCING TO WORK ON IS MOSTLY MID TO UPPER LEVEL.
BASES ON ANY SHRA/TS COULD BE 8-10 KFT. RELATIVELY DRY NEAR SFC
LAYER COULD ENHANCE ANY GUSTINESS AROUND A STORM...OTHERWISE IMPACTS
VIA CIGS/VSBY LOOK MINIMAL AT THIS TIME.
CONFIDENCE NOT HIGH...BUT ENOUGH SUPPORT FROM THE VARIOUS MESO
MODELS TO CONTINUE THE VCSH MENTION AT KRST/KLSE FOR A PERIOD
TONIGHT.
FRONT TO THE NORTH WILL SLIDE THROUGH TUE MORNING...SWITCHING THE
WINDS TO THE NORTHWEST. HIGH PRESSURE WILL FOLLOW IN ITS WAKE...WITH
QUIET VFR CONDITIONS THEN INTO TUE NIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
305 PM CDT MON AUG 6 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...JLR
LONG TERM....JLR
AVIATION.....RIECK
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
140 AM EDT TUE AUG 7 2012
.PREV DISCUSSION... /ISSUED 1014 PM EDT MON AUG 6 2012/
UPDATE...
MAIN AREA OF PERSISTENT CONVECTIVE DEVELOPMENT PAST DIURNAL
HEATING HAS BEEN ACROSS THE NORTHERN PORTION OF THE AREA ALONG AN
AXIS OF SFC CONVERGENCE. AS WEAK UPPER LOW CONTINUES TO BE
CENTERED NEAR SW GA...A MOIST TROPICAL AIRMASS REMAINS IN PLACE
WITH PWATS OF 2 INCHES OR GREATER. ANY REMNANT BOUNDARY OR WEAK
FORCING FOR ASCENT WILL MAINTAIN AT LEAST SHOWER POTENTIAL THROUGH
THE OVERNIGHT. WITH THE LATEST HRRR SOLUTION SUPPORTING CONTINUED
ACTIVITY IN THE NORTH INTO THE EARLY MORNING...HAVE INCLUDED
LIKELY POPS ACROSS THE NORTH UNTIL 06Z AND CHANCE POPS ELSEWHERE
CONTINUING INTO TUESDAY. PRIMARILY SHOWERS POSSIBLE WITH ISOLATED
THUNDER. MADE ONLY MINOR TREND TWEAKS TO TEMPS AND DEWPOINTS.
PREVIOUS DISCUSSION FOLLOWS...
03
PREV DISCUSSION... /ISSUED 225 PM EDT MON AUG 6 2012/
SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
WEAK TROPICAL LOW HAS WORKED ITS WAY INTO SOUTHEAST ALABAMA THIS
AFTERNOON AND IS PROGGED TO REMAIN IN THAT VICINITY THROUGH TONIGHT.
INDICATIONS ARE THE LOW WILL BEGIN LIFTING NORTHEAST ACROSS THE
FORECAST AREA BY TUESDAY AFTERNOON AND TUESDAY NIGHT. AS LONG AS THE
LOW REMAINS ACROSS THE SOUTHERN PORTIONS OF ALABAMA AND GEORGIA THE
WEAK COLD FRONT EXTENDING FROM THE MID-ATLANTIC COASTAL REGION TO
THE SOUTHERN PLAINS SHOULD BE HELD AT BAY. INSTABILITY REMAINS
MARGINAL THROUGH THE PERIOD AS THE VERTICAL TEMPERATURE PROFILES
REMAIN NEARLY MOIST ADIABATIC. BIGGEST THREAT FROM ANY CONVECTION IS
LIKELY TO BE LOCALLY HEAVY RAIN AS PRECIPITABLE WATER VALUES
CONTINUE TO HOVER AROUND THE 2 INCH RANGE. HARD TO TIME WHEN THE
BEST CHANCES FOR PRECIPITATION WILL BE THROUGH THE PERIOD AS
NORTHWEST UPPER FLOW IS LIKELY TO TRANSPORT A SERIES OF WEAK WAVES
INTO THE AREA. IN GENERAL I HAVE STUCK WITH A DIURNAL MAXIMUM
PATTERN TO THE PROBABILITY OF PRECIPITATION. EXTENSIVE CLOUD COVER
AND WIDESPREAD PRECIPITATION WILL KEEP TEMPERATURES AT OR BELOW
SEASONAL NORMALS THROUGH THE PERIOD.
20
LONG TERM /WEDNESDAY THROUGH MONDAY/...
TROPICAL MOISTURE REMAINS OVER THE REGION WEDNESDAY HOWEVER THE
WESTERLIES DIP DOWN A LITTLE INTO NORTH GA AND TRIES TO PUSH A WEAK
SURFACE TROUGH INTO THE NORTHERN PART OF THE CWA. THIS WILL AID IN
SHOWERS/THUNDERSTORMS...MAINLY DURING THE AFTERNOON WEDNESDAY ACROSS
THE CWA. NO OTHER CHANGES ARE PLANNED FOR THE REST OF THE LONG TERM.
PREVIOUS LONG TERM DISCUSSION FOLLOWS...
PREV LONG TERM DISCUSSION... /ISSUED 337 AM EDT MON AUG 6 2012/
/WEDNESDAY THROUGH SUNDAY/... OVERALL PATTERN REMAINS THE SAME
WITH BOTH GFS AND ECMWF IN GENERAL AGREEMENT. THE FORECAST AREA
PERSISTS IN A BROAD EASTERN TROUGH WITH A STALLED SURFACE BOUNDARY
WITH WEAK WAVES TRAVELING ALONG IT. WITH ABUNDANT TROPICAL
MOISTURE AVAILABLE...HAVE KEPT THE POPS IN AN AVERAGE 40 TO 50
PERCENT RANGE UNTIL THE END OF THE WEEK. MODELS STILL SHOWING SOME
DRYING AS AN UPPER CLOSED LOW DEEPENS OVER THE GREAT LAKES. THIS
MAY PUSH THE SURFACE BOUNDARY INTO SOUTH GEORGIA BEGINNING ON
SATURDAY. SO HAVE REDUCED THE POPS A BIT FOR SATURDAY AND SUNDAY.
WITH POTENTIAL FOR INCREASED CLOUD COVER...HIGHS IN THE MID 80S TO
LOW 90S LOOK REASONABLE FOR MUCH OF THE AREA.
17/41
&&
.AVIATION...
06Z UPDATE...
VFR CIGS ACROSS THE AREA WILL LOW TO MVFR AND THEN IFR BY BETWEEN
10-12Z. MVFR AND BRIEFLY LOWER VSBYS EXPECTED...THOUGH TAF WILL
ONLY CARRY MVFR. SHRA AROUND OFF AND ON THROUGH MOST OF THE DAY
WITH THE POSSIBILITY OF TSRA THIS AFTERNOON...HAVE CONTINUED
PROB30 FOR TSRA. EASTERLY WINDS WILL SHIFT MORE SSE LATER THIS
MORNING...BACK TO EAST THIS EVENING. SOME GUIDANCE SUGGESTING
BRIEF SSW WINDS BETWEEN 14-18Z BUT HAVE KEPT THEM ON THE EAST SIDE.
EXPECT ANOTHER ROUND OF MVFR TO IFR CIGS AGAIN WEDNESDAY MORNING.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM ON MOST ELEMENTS.
LOW ON POTENTIAL FOR WINDS TO SHIFT SSW MIDDAY.
LOW ON POTENTIAL FOR TSRA IMPACTS AT ATL.
TDP
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 86 70 87 71 / 60 50 60 40
ATLANTA 86 73 87 73 / 60 50 60 40
BLAIRSVILLE 82 66 83 64 / 70 50 40 40
CARTERSVILLE 86 68 89 69 / 60 50 50 40
COLUMBUS 86 74 90 74 / 60 50 60 40
GAINESVILLE 86 71 86 71 / 60 50 60 40
MACON 86 73 88 73 / 60 50 60 40
ROME 86 69 91 70 / 60 50 40 40
PEACHTREE CITY 87 69 87 70 / 60 50 60 40
VIDALIA 87 74 88 75 / 70 50 60 40
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1139 PM CDT MON AUG 6 2012
.DISCUSSION...
ISSUED 858 PM CDT MON AUG 6 2012
CENTRAL ILLINOIS WILL BE ON THE WESTERN EDGES OF DEPARTING SURFACE
HIGH PRESSURE OVERNIGHT. THE RIDGE AXIS WILL STILL GENERALLY
RESIDE OVER OUR COUNTIES UNTIL LATE TONIGHT...PROVIDING LIGHT AND
VARIABLE WINDS UNDER MOSTLY CLEAR SKIES.
ONE ITEM OF NOTE FOR LATE TONIGHT FOR OUR WESTERN COUNTIES MAY BE
A STORM COMPLEX THAT IS PROJECTED TO DEVELOP IN SW MINNESOTA AND
NW IOWA...ALONG AN INVERTED TROUGH EXTENDING FROM LOW PRESSURE IN
WESTERN NEBRASKA. THE HRRR MODEL INDICATES THEY MAY MOVE EAST-
SOUTHEAST ACROSS IOWA TOWARD SUNRISE. WHILE THE STORMS SHOULD
REMAIN WEST-NW OF OUR AREA...SOME CIRRUS CLOUDS FROM THAT COMPLEX
MAY COVER OUR WESTERN COUNTIES...HELPING TO KEEP THEIR LOW TEMPS
SLIGHTLY WARMER THAN THE REST OF OUR CWA. OUR GRIDS ALREADY
REFLECTED THAT POSSIBILITY.
AS FOR WINDS...THE RIDGE AXIS WILL BEGIN TO SLIDE JUST EAST OF
ILLINOIS BY 12Z TUESDAY...WHICH MAY TRANSLATE INTO WINDS
DEVELOPING A SOUTHWEST DIRECTION BY SUNRISE IN OUR WESTERN
COUNTIES. THAT RETURN FLOW MAY CARRY SLIGHT WARM ADVECTION AS
WELL...WHICH WOULD ALSO WORK TO KEEP THE WESTERN COUNTIES SLIGHTLY
WARMER.
THE FORECAST GRIDS WERE GENERALLY IN GOOD SHAPE...WITH ONLY SOME
MINOR ADJUSTMENTS TO THE SKY GRIDS TO ACCOUNT FOR LATE NIGHT
CIRRUS IN THE WEST. NO FORMAL ZONE UPDATE WILL BE NEEDED FOR THE
SMALL CHANGES. UPDATED GRIDS WILL BE AVAILABLE SHORTLY.
SHIMON
&&
.AVIATION...
ISSUED 1139 PM CDT MON AUG 6 2012...FOR THE 06Z TAFS
THE MAIN CONCERN WILL BE A WEAK TROUGH DROPPING INTO CENTRAL
ILLINOIS TOMORROW AFTERNOON. PIA/BMI WILL HAVE THE BEST CHANCES TO
SEE INCREASING MID CLOUDS AFTER 18Z. A FEW SHOWERS OR STORMS ARE
INDICATED IN THE QPF FIELDS OF THE MODELS...BUT THEY ARE GENERALLY
TOO AGGRESSIVE WITH PRECIP IN THESE MARGINAL CASES DURING A
DROUGHT. I WENT WITH A BROKEN CLOUD DECK AT PIA/BMI TMRW AFTN...IN
LIEU OF A VCSH.
WINDS MAY INCREASE TO AROUND 10KT FROM THE W-SW FOR PIA/BMI BY
MIDDAY...BUT WEAKER WINDS SHOULD PREVAIL FOR THE E-S TERMINALS.
NO REDUCTION TO VIS IS EXPECTED IN THE GENERALLY DRY AIRMASS.
SHIMON
&&
.PREV DISCUSSION...
ISSUED 255 PM CDT MON AUG 6 2012
HIGH PRESSURE DOMINATING CENTRAL ILLINOIS WEATHER...AS WELL AS
MUCH OF THE MIDWEST THROUGHOUT THE FORECAST. UPPER RIDGING
CONTINUES OVER THE WESTERN HALF OF THE CONUS AND A FEW SYSTEMS
DIVE INTO THE GENERAL BROAD TROF OVER THE GREAT LAKES AND EASTERN
HALF OF THE COUNTRY. DEGREE OF INFLUENCE DEPENDING ON HOW DEEP THE
SYSTEMS DIG INTO THE TROF. SEEN THIS PATTERN SEVERAL TIMES OVER
THE SUMMER...WITH TEMPERATURES ON THE EDGE OF A MID LEVEL THERMAL
GRADIENT...A LITTLE MOVEMENT EITHER WAY OF THE WAVE PATTERN MAKES
A RATHER LARGE DIFFERENCE. THAT BEING SAID...STABILITY OF THE WAVE
PATTERN SEEMS TO BE IN AGREEMENT ACROSS OPERATIONAL MODELS.
HOWEVER...THE ISSUES COME INTO PLAY ON THE STRENGTH AND TIMING OF
THE WAVES FROM WED NIGHT INTO THU NIGHT...WITH THE NEXT CHANCE FOR
PRECIP.
SHORT TERM...TONIGHT AND TOMORROW...
QUIET WEATHER IN THE OVERNIGHT UNDER A RIDGE AXIS. CLEAR NIGHT AND
CALM WINDS EXPECTED. TOMORROW EXPECTED TO BE THE WARMEST OF THE
FORECAST...WITH LOW TO MID 90S ACROSS THE REGION AS THAT THERMAL
GRADIENT SLIPS A LITTLE FURTHER NORTH WITH THE WEAKER DIG INTO THE
EASTERN TROF. 19C TO 20C AT 850MB AND A RATHER DRY COLUMN WILL
KEEP THE TEMPS FAR ABOVE TODAY`S TEMPS. FLOW REMAINS RATHER
AMBIGUOUS THROUGH THE NEXT COUPLE OF DAYS WITH THE HIGH ANCHORING
THE WEATHER OVERALL.
LONG TERM...WEDNESDAY THROUGH SUNDAY...
NEXT SYSTEM ON APPROACH WED NIGHT. FORECAST MODELS DIFFERING A BIT
WITH TIMING AND STRENGTH OF THE INITIAL WAVE FOR MIDWEST. GFS
EARLY AND WET...BRINGING IN QPF ON TUES NIGHT. HOWEVER...BOTH
ECMWF AND NAM ARE SLIGHTLY SLOWER AND MORE CONSERVATIVE WITH
INITIAL PRECIP...KEEPING BACK UNTIL WED NIGHT. THINK SOME
SPRINKLES MAY BE ABLE TO DEVELOP WITH AGGRESSIVE ENOUGH OF A CU
FIELD ON WEDNESDAY...AND HAVE ADDED THAT GRID...BUT WOULD LIKE TO
DEFER THE FORECAST TO THE MORE CONSERVATIVE SOLUTION CONSIDERING
THE ONGOING DROUGHT AND THE TREND OF THE SUMMER IN GENERAL. POPS
THURSDAY AND INTO THURS NIGHT. FRI SHOULD BE MOSTLY DRY...BUT SOME
AFTERNOON POP UPS WILL LIKELY REMAIN POSSIBLE ON THE EASTERN
BORDER OF THE STATE WITH THE EXITING SYSTEM UNLESS IT CONTINUES TO
ACCELERATE A BIT. REMAINING FORECAST IS DRY...AS GFS IS OVERDOING
THE EXTENDED A BIT...AND THE ECMWF KEEPS THE
MIDWEST...PARTICULARLY THE BULLSEYE IN THE MIDDLE OF CENTRAL
ILLINOIS...DRY.
HJS
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1122 PM MDT MON AUG 6 2012
.UPDATE...
ISSUED AT 415 PM MDT MON AUG 6 2012
UPDATED TO INCLUDE THUNDERSTORM CHANCES IN THE WEST. CONVECTION
HAS INITIATED ALONG A SURFACE TROUGH IN NORTHEAST COLORADO. STORM
MOTIONS ARE ALMOST DUE SOUTH SO NOT SURE HOW FAR EAST THESE WILL
BE ABLE TO MOVE THIS EVENING. FURTHERMORE...DEW POINTS ARE QUITE
LOW. FOR THOSE REASONS...LIMITED POPS TO 30 IN THE FAR NORTHWEST
AND 20 ELSEWHERE.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 236 PM MDT MON AUG 6 2012
THROUGH TONIGHT...SHORTWAVE TROUGH WILL TRANSLATE SOUTHEASTWARD THE
NORTHERN PLAINS. STRONGEST FORCING FOR ASCENT WILL REMAIN NORTHEAST
OF THE FORECAST AREA. HOWEVER...WITH A SURFACE LOW DEVELOPING ACROSS
NORTHEAST COLORADO...DO EXPECT ISOLATED TO SCATTERED THUNDERSTORMS
TO DEVELOP ACROSS NORTHERN/NORTHEASTERN PORTIONS OF THE FORECAST
AREA AFTER 06Z. WILL ALSO NEED TO MONITOR A WEAK AREA OF SURFACE
CONVERGENCE JUST TO THE WEST OF THE FORECAST AREA WHERE A SHALLOW CU
FIELD CONTINUES TO DEVELOP. LATEST RUNS OF THE HRRR DEVELOP
CONVECTION IN THIS AREA WITH A GENERAL EASTWARD/SOUTHEASTWARD
MOVEMENT. NOT COMPLETELY SOLD ON THIS SOLUTION SO OPTING TO KEEP
POPS OUT OF THE FORECAST FOR NOW. WILL NEED TO MONITOR AND
REEVALUATE AS THE AFTERNOON GOES ON.
TUESDAY...SLIGHTLY STRONGER SHORTWAVE TROUGH WILL BEGIN TO IMPACT
THE REGION DURING THE DAY TUESDAY. WILL LIKELY SEE A LULL IN PRECIP
DURING THE MORNING HOURS IN THE WAKE OF THE DEPARTING OVERNIGHT
SYSTEM WITH PRECIP CHANCES INCREASING DURING THE AFTERNOON HOURS.
DEEP LAYER SHEAR WILL INCREASE TO AROUND 30-35 KTS DURING THE
AFTERNOON HOURS WHICH WILL HELP ORGANIZE THUNDERSTORM UPDRAFTS. ONE
LIMITING FACTOR WILL BE MINIMAL AVAILABLE INSTABILITY WITH SBCAPE
VALUES OF 500-1000 J/KG. POINT SOUNDINGS DO INDICATE AN INVERTED-V
STRUCTURE SO WOULD ANTICIPATE GUSTY OUTFLOW WINDS BEING THE PRIMARY
THREAT TOMORROW AFTERNOON/EVENING.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 236 PM MDT MON AUG 6 2012
TUESDAY NIGHT-THURSDAY...LARGE SCALE H5 RIDGE WILL AMPLIFY OVER THE
NORTHERN ROCKIES THROUGH THE PERIOD...WITH MAIN CONCERN BEING THE
CHANCE FOR LINGERING PRECIPITATION OVER PORTIONS OF THE CWA TUESDAY
NIGHT WITH PRECIPITATION CHANCES LOOKING TO BE VERY SMALL AFTER THAT
LARGE SCALE SUBSIDENCE OVERSPREADS THE AREA WITH DEEP LAYER FLOW
ALOFT OUT OF THE NORTH-NORTHWEST KEEPING ANY DEEP MOISTURE RETURN TO
THE AREA LIMITED. FOR TUESDAY NIGHT HOWEVER...DIV Q FIELDS SUGGEST LARGE
SCALE SUBSIDENCE WILL OVERSPREAD THE CWA AFTER 03Z...WHICH SHOULD
BEGIN TO DIMINISH PRECIPITATION POTENTIAL PRETTY QUICKLY OVERNIGHT.
WHILE THERE WILL BE LARGE SCALE SUBSIDENCE...THINK THERE WILL BE AT
LEAST A SHORT WINDOW FOR PRECIPITATION DURING THE EVENING
HOURS...MAINLY ALONG AND SFC TROUGH EXPECTED TO STRETCH FROM
FIRSTVIEW TO MCCOOK. WITH MIXED LAYER CINH VALUES FAIRLY HIGH AND
AFOREMENTIONED SUBSIDENCE CONFIDENCE IN PRECIPITATION FAIRLY LOW.
ALTHOUGH SREF AND GEFS HAVE FAIRLY HIGH PROBABILITIES (>75%) IN
EASTERN CWA...DO NOT THINK CONFIDENCE IS HIGH ENOUGH TO GO MORE THAN
20-40 PERCENT CHANCES THROUGH THE EVENING HOURS.
AS H5 RIDGE AMPLIFIES AND MUCH DRIER AIR WORKS INTO THE CWA...THINK
PRECIP CHANCES WILL REMAIN VERY LOW TO PRACTICALLY NOTHING THROUGH
THE REST OF THE PERIOD. SEEMS TO BE A FAIRLY LARGE SPREAD BETWEEN
MODELS WITH RESPECT TO HOW WARM THINGS WILL GET ACROSS THE AREA.
WHILE GFS IS MUCH COOLER THAN OTHER MODELS AND GIVEN THE OVERALL
FLOW PATTERN WOULD NOT BE UNHEARD OF FOR A COOLER AIR MASS TO BACK
INTO CWA. THAT BEING SAID...GFS HAS A FAIRLY WELL DOCUMENTED COLD
BIAS THIS SUMMER AND THINK OVERALL BIAS CORRECTED VALUES IN THE
MID/UPPER 90S LOOK REASONABLE. MUCH DRIER AIR IS EXPECTED TO MOVE
INTO THE AREA WEDNESDAY AFTERNOON ALLOWING RH`S TO APPROACH CRITICAL
VALUES. OVERALL DO NOT THINK CONDITIONS WILL BE LONG LASTING AND DO
NOT PLAN ON ISSUING ANY WATCHES AT THIS POINT AND THINK THE BIGGEST
IMPACT OF DRIER AIR MASS WILL BE TO ALLOW TEMPS TO BE RATHER COOL
GIVEN LIGHT WINDS/CLEAR SKIES AND DRY AIR.
IN THE EXTENDED (FRIDAY-NIGHT-MONDAY)...WHILE MEDIUM RANGE MODELS
START THE PERIOD IN REASONABLE AGREEMENT...DIFFERENCES EMERGE FAIRLY
QUICKLY IN THE PERIOD WITH RESPECT TO HANDLING OF SHORT WAVE TROUGH
MOVES AROUND TOP OF THE AMPLIFIED H5 RIDGE AND WHAT IMPACT...IF ANY
THIS TROUGH HAS ON LARGE SCALE RIDGE PATTERN. THESE DIFFERENCES DO
NOT LEAD TO A LOT OF CONFIDENCE IN FORECAST FROM SATURDAY ON...AND
PLAN ON KEEPING FORECAST NEAR CONSENSUS DATA FOR THE TIME BEING
UNTIL A BETTER FAVORED SOLUTION APPEARS...ALTHOUGH THINK WEIGHTING
BLENDS A BIT MORE TOWARDS THE ECWMF IS IN ORDER BASED ON THE GEFS
DATA. LATEST ECMWF HAS COME IN A BIT COOLER THAN PREVIOUS RUNS AND
GIVEN EASTERLY SFC FLOW AND STRONG HIGH AROUND BASE OF SFC HIGH
THINK A GENERAL COOLING TREND IS IN ORDER. WITH MOST NIGHTS NOT
REALLY BRINGING A CLEAR SIGNAL FOR WARM TEMPS (DENSE CLOUD
COVER...STRONG WINDS...ETC) HAVE WORKED THE 3-5 DEGREE COOLER BIAS
CORRECTED SOLUTIONS INTO OVERNIGHT LOW FORECASTS WHERE I COULD...TO
PICK UP OUR NORMALLY COLDEST SPOTS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1115 PM MDT MON AUG 6 2012
SURFACE TROUGH NEAR THE COLORADO AND KANSAS STATE LINE WILL MOVE
LITTLE THROUGH TOMORROW RESULTING IN LIGHT AND VARIABLE WINDS.
PRECIPITATION CHANCES WILL BE LOW...LATEST MODEL GUIDANCE SUGGESTS
LIGHT RAIN SHOWERS AND POSSIBLY AN ISOLATED THUNDERSTORM MOVING
OUT OF COLORADO LATE TONIGHT AND INTO TUESDAY MORNING. CONFIDENCE
IS NOT VERY GOOD...AS MODELS HAVE INITIALIZED FAR TOO WET...SO
DECIDED NOT TO MENTION ANY IN THE TAFS UNTIL RADAR TRENDS SUPPORT
IT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...024
SHORT TERM...FOLTZ
LONG TERM...JRM
AVIATION...024
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
433 AM EDT TUE AUG 7 2012
.SYNOPSIS...
DRY AND MILD CONDITIONS WILL CONTINUE THROUGH MOST OF WEDNESDAY AS
HIGH PRESSURE PUSHES EAST OF THE AREA. A COLD FRONT WILL APPROACH
FROM THE NORTHWEST LATE ON WEDNESDAY AND BRING A SLIGHT CHANCE OF
THUNDERSTORMS. A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS WILL
RETURN TO THE REGION THURSDAY INTO FRIDAY WHEN A LOW PRESSURE
SYSTEM CROSSES THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES THE UPPER OHIO VALLEY
IN A DRY AND WEAK ZONAL FLOW. AT THE SURFACE, A BROAD AREA OF HIGH
PRESSURE EXTENDS FROM THE MISSOURI VALLEY ACROSS THE OHIO VALLEY
AND INTO THE MID-ATLANTIC. ASIDE FROM SOME CIRRUS PUSHING EAST OF
PITTSBURGH SKIES ARE CLEAR THIS MORNING.
CLEARING FROM THE WEST WILL CONTINUE THIS MORNING AS UPPER LEVEL
MOISTURE PUSHES EASTWARD. BROAD HIGH PRESSURE WILL CONTINUE TO
DOMINATE TODAY AND TONIGHT. THIS WILL ALLOW FOR CLEAR SKIES
THROUGH THIS PERIOD. DESPITE ABUNDANT SUNSHINE, HIGHS TODAY ARE
CLOSER TO THE COOLER MAV GUIDANCE, RANGING FROM THE LOWER 80S
ACROSS THE I-80 CORRIDOR AND EASTERN RIDGES TO THE UPPER 80S
ACROSS PORTIONS OF EASTERN OHIO AND NORTH-CENTRAL WV. ONE MORE
NIGHT OF RADIATIONAL COOLING WILL OCCUR TONIGHT WITH MOSTLY CLEAR
SKIES AND NEAR CALM WINDS. WITH A SLIGHT SOUTHERLY COMPONENT TO
WINDS THIS WILL ALLOW FOR A SLIGHTER WARMER NIGHT ACROSS MOST
LOCATIONS WITH LOWS RANGING FROM THE UPPER 50S TO THE LOWER 60S.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
THERE IS GFS/ECMWF/NAM AGREEMENT THAT BENIGN WEATHER WILL CONTINUE
EARLY ON WEDNESDAY WITH A DEEP LAYER OF DRY AIR IN PLACE. A WEAK
SHORT WAVE WILL MOVE EASTWARD ACROSS THE AREA AND A COLD FRONT
WILL DROP SOUTHEASTWARD INTO THE REGION LATE IN THE DAY. 850-700MB
OMEGA INDICATES THERE MAY BE ENOUGH FORCING FOR A FEW SHOWERS OR
THUNDERSTORMS TO DEVELOP ALTHOUGH MOISTURE WILL STILL BE FAIRLY
LIMITED. THUS, WENT WITH SCHC POPS FOR LATE IN THE DAY. WITH THE
LOSS OF HEATING, ANY CONVECTION WILL DIMINISH WEDNESDAY NIGHT.
WEAK WARM AIR ADVECTION AHEAD OF THE FRONT WILL ALLOW FOR TEMPS TO
WARM TO AROUND 5 DEGREES ABOVE NORMAL FOR HIGHS. WITH WARM TD
ADVECTION ONGOING, TEMPS WILL ONLY DROP TO THE MID 60S ACROSS MOST
OF THE AREA WEDNESDAY NIGHT.
FOR THURSDAY INTO FRIDAY, A BLEND OF THE GFS/ECMWF WAS USED TO
DEPICT A MID-LEVEL LONG WAVE TROUGH SWINGING FROM THE UPPER MIDWEST
INTO THE OHIO VALLEY AND A WEAK SURFACE LOW MOVING FROM THE
MISSOURI VALLEY INTO THE UPPER OHIO VALLEY. ON THURSDAY, THE
INITIAL COLD FRONT WILL SLIDE ACROSS THE AREA WITH MODERATE
INSTABILITY DEVELOPING. HIGH TEMPS WILL BE A FEW DEGREES ABOVE
NORMAL AHEAD OF THE FRONT. HIGH CHANCE POPS WILL CONTINUE INTO
FRIDAY WITH SYNOPTIC FORCING FROM THE LOW AS IT CROSSES THE AREA.
IN THE WAKE OF THE FRONT, COOLER AIR WILL BE USHERED INTO THE AREA
FOR FRIDAY WITH HIGHS AROUND 5 TO 10 DEGREES BELOW NORMAL.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
HIGHLIGHTS:
- NO SEVERE WEATHER EXPECTED
- BELOW NORMAL TEMPERATURES
- WELCOME RAINFALL LATE THIS WEEK
IN THE WAKE OF THE FRONT...EXPECT TEMPERATURES TO BE COOL INTO
THE WEEKEND. DAYTIME HIGHS WILL BE IN THE LOW TO MID 70S WHICH IS
TEN DEGREES BELOW NORMAL.
LONG RANGE ENSEMBLE PREDICTION SYSTEMS CONTINUE TO EXIT THE CLOSED
MID LEVEL CYCLONE SLOWLY NE SATURDAY. THE SOUTHERN EXTENT OF THE
TROWAL IS PROJECTED TO BE JUST N OF OUR CWA...HOWEVER TIMING THIS
FAR OUT CAN CERTAINLY CHANGE. CARRIED PCPN MENTION A LITTLE LONGER
THAN AFOREMENTIONED MODELS INDICATE. BUFR SOUNDINGS AND LLVL RH
PROGS ILLUSTRATE A SATURATED BOUNDARY LAYER...SO CLOUDS SHOULD
TAKE THE BETTER PART OF SATURDAY TO VACATE THE REGION...ESPECIALLY
THE MTNS. WOULD NOT RULE OUT A PERIOD OF DRIZZLE IN THE HIGHER
TERRAIN SAT MRNG. THERMODYNAMIC INSTABILITY IS NIL...SO REMOVED
THUNDER FROM THE FORECAST FOR THE UPCOMING WEEKEND. CONDITIONS
IMPROVE DAYS 6 AND 7 WITH THE ESTABLISHMENT OF ZONAL FLOW AND A
RETURN TO MORE SEASONAL TEMPERATURES.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
HIGH CLOUDS WILL SLOWLY CLEAR FROM NW TO SE THROUGH THE EARLY
MORNING HOURS. THESE HIGH CLOUDS WILL LIKELY PRECLUDE ANYTHING
WORSE THAN BRIEF MVFR VISIBILITIES OVERNIGHT FROM KLBE TO KAGC AND
ALL POINTS SOUTH. NORTH OF THAT LINE...CLEARING AND DECENT
RADIATION WILL MAKE THE CHANCES OF BRIEF MVFR VISIBILITIES A BIT
HIGHER. HOWEVER...GIVEN THE CONTINUED RATHER WIDE DEWPOINT
DEPRESSIONS AT KPIT AND KDUJ...AND LIGHT FOG MAY BE MORE DIFFICULT
TO MANAGE THERE. OTHERWISE...SUBSIDENCE AND DEW FORMATION SEEM
LIKELY TO SETTLE OUT DEWPOINTS BY A COUPLE DEGREES
OVERNIGHT...WHICH WILL MEAN AND FOG WORSE THAN MVFR IS LIKELY TO
BE EXTREMELY LOCALIZED AND LIKELY AROUND A RIVER (SUCH AS KHLG).
FRIES
.OUTLOOK...MONDAY NIGHT THROUGH SATURDAY...
VFR IS EXPECTED THROUGH WEDNESDAY BEFORE RESTRICTIONS ARE POSSIBLE
IN SHRA/TSRA THURSDAY THROUGH SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1107 PM CDT MON AUG 6 2012
.UPDATE...
UPDATED TO INCLUDE 06Z AVIATION DISCUSSION BELOW.
&&
.DISCUSSION...
OVERVIEW...ABOVE NORMAL TEMPS EXPECTED TOMORROW BEFORE SHOWERS AND
STORMS ON WEDNESDAY KICK START A COOLING TREND THAT WILL LAST THROUGH
THE WEEKEND. RAIN CHANCES ON THURSDAY AND FRIDAY ARE BASED ON TWO
INDEPENDENT FEATURES. INCREASED POPS DURING THIS TIME FRAME.
CERTAINLY A NON ZERO CHANCE OF PRECIP TONIGHT IN WESTERN WI AND IN
FAR SOUTHERN MN. A COUPLE RUNS OF THE HRRR AND THE RAP BOTH
HIGHLIGHT THESE AREAS WITH SHOWERS LATE THIS EVENING. SEEING THE
EFFECTS OF THE COLD FRONT STRETCHED OUT ACROSS NORTHERN MM.
GETTING NEAR SURFACE CONVERGENCE SHOWING UP IN THE MESO ANALYSIS
BUT ALSO PRETTY OBVIOUS JUST BASED ON THE LOW LEVEL FLOW. NICE
BAND OF CUMULUS AND EVENED EMBEDDED SHOWERS VISIBLE THIS
AFTERNOON. SECONDLY...SUBTLE SHORTWAVE ENERGY IN THE EASTERN
DAKOTAS ALSO DROPPING SOUTH THIS AFTERNOON. NOT MUCH BEING
REFLECTED IN THE SHORT TERM HEIGHT/VORTICITY FIELDS...BUT
DEFINITELY SOMETHING APPARENT ON THE WATER VAPOR. IN
GENERALLY...TRIMMED THE POPS BACK TONIGHT. POP VALUES WERE ALREADY
LOW...IN THE 20-30%...BY LIMITED THE AREAL EXTEND OF THE POPS
COMPARED TO THE PREVIOUS FORECAST. THINK A VAST MAJORITY OF THE
FORECAST AREA REMAINS DRY EVEN WITH THE WEAK FRONTAL PASSAGE.
WONDERING IF THE HIGH DEWPOINT BIAS OFF THE RAP IS PLAYING INTO
THE EXTRA PRECIP TONIGHT.
REALLY CAN NOT SEE HOW MUCH DIFFERENT TOMORROW WILL BE COMPARED
TO TODAY IN TERMS OF TEMPERATURES. IT MIGHT BE A DEGREE OR TWO
COOLER THAN TODAY...BUT 70-80% OF THE GUIDANCE HAS FORECAST 2M
TEMPS AND 850MB TEMPS VERY SIMILAR TO WHAT WAS SEEN TODAY. STILL
LOOKS GOOD FOR AT LEAST SCATTERED SHOWERS AND THUNDERSTORMS ON
WEDNESDAY WITH SHORTWAVE ROTATING AROUND THE RIDGE OVER THE NEXT
36-48HRS. SHEAR IS MARGINAL WITH RELATIVELY WEAK MID LEVEL
FLOW...BUT FORCING AND INSTABILITY SHOULD NOT BE A PROBLEM...SO
LIKELY POPS ARE NOT A STRETCH AT THIS POINT. WE BLEED THE POPS
INTO THURSDAY DUE TO THE UPPER LOW DROPPING SOUTH OUT OF THE
INTERIOR OF CANADA...NOW IN NORTH CENTRAL CANADA BETWEEN 70-75
NORTH. THIS SYSTEM HAS PROBABLY TRENDED A LITTLE BIT SLOWER AND
STRONGER WITH TIME OVER THE LAST COUPLE DAYS. THERE IS NOT MUCH
RECOVERY IN TERMS OF INSTABILITY...BUT COOL TEMPS ALOFT SUGGESTS
SHOWERY ACTIVITY WITH EMBEDDED THUNDER. COOLED TEMPS ON
THURSDAY...MIGHT BE HARD TO GET MUCH ABOVE 75 IN SOME LOCATIONS IN
CENTRAL MN AND WI WITH CLOUD COVER AND SHOWERS.
&&
.AVIATION.../06Z TAF ISSUANCE/
VFR CONDS TO PREVAIL THROUGHOUT THE 07/06Z TAF SET /EXCEPT FOR
POSSIBLE PRE-DAWN GROUND FOG ISSUES AT THE WI TAF SITES IN THE
MORNING/. A COLD FRONT WILL DROP THROUGH THE REGION OVERNIGHT.
VERY LITTLE CONVECTIVE ACTIVITY ALONG THE LINE EXCEPT ALONG ITS
ERN FRINGES IN THE ARROWHEAD REGION WHICH MAY DROP INTO NWRN WI.
RADAR IMAGERY SHOWS VERY LITTLE YET THERE IS A WEAK UPPER LEVEL
DISTURBANCE MOVING IN CONJUNCTION WITH THE FNT THAT MAY BE ENOUGH
TO PRODUCE ISOLD SHWRS OVER NWRN INTO CENTRAL WI...BUT CHCS ARE
TOO LOW FOR ITS INCLUSION...ESP WITH THE DRY LOWER-MIDDLE LAYERS
DEPICTED ON MODEL SOUNDINGS. THUS...HAVE KEPT THE TAFS DRY.
COMPACT LOW LEVEL MOISTURE UNDERNEATH THE NIGHTLY INVERSION OVER
WI MAY ALSO PRODUCE PRE-DAWN GROUND FOG...WITH KEAU
CLIMATOLOGICALLY FAVORABLE. AFTER DAWN...PLENTY OF SUNSHINE WITH
SHIFTING WINDS. HIGH CLOUDS INCRS LATE IN THE DAY THROUGH TMRW
EVENING AHEAD OF A STRONGER UPPER LEVEL DISTURBANCE MOVG TWD THE
REGION. POPS INCRS AFTER THE 06Z TIMEFRAME SO NO POPS NEEDED AT
THE TAIL END OF THIS TAF SET.
MSP...VFR CONDS THROUGHOUT. HIGH CLOUDS INCRS LATE IN THE DAY THRU
TMRW NIGHT AS HIGH PRES DEPARTS AND AN UPPER LEVEL DISTURBANCE
APPROACHES. WILL SEE CIGS IN THE 10-15 KFT RANGE BY TMRW EVENING
INTO TMRW NIGHT. CHCS FOR PRECIP STILL LESS THAN 20 PERCENT
THROUGH 12Z WED SO NO POPS INCLUDED AT THIS POINT. WINDS LGT/VRBL
OVERNIGHT THEN LESS THAN 10 KT FROM MAINLY THE N...ALTHOUGH THE
DIRECTIONAL FORECAST WILL BE A BIT TRICKY WITH THE FRONT PUSHING
THROUGH TNGT FOLLOWED BY HIGH PRESSURE SCOOTING ACROSS THE REGION.
OUTLOOK...
.WEDNESDAY...VFR WITH MVFR/TSRA POSSIBLE. WINDS SE AT 5-10 KTS.
.THURSDAY...MVFR CLOUDS AND SHRA DURING THE DAY...BECOMING VFR
OVERNIGHT. WINDS N AT 10G15 KTS.
.FRIDAY...VFR. WINDS E 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JPC
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
355 AM EDT TUE AUG 7 2012
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN STALLED JUST NORTH OF THE AREA
TODAY THROUGH LATE WEEK BEFORE MOVING TO NEAR THE COAST OVER THE
WEEKEND. VERY MOIST AIR WILL THE THREAT OF RAIN HIGH THROUGH LATE
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 335 AM TUESDAY...PER RADAR TRENDS...PRECIPITATION IS RAPIDLY
FILLING IN TO THE SW/W OF THE MHX CWA AND BEGINNING TO MOVE INTO
OUR SOUTHERN COASTAL PLAINS COUNTIES. HAVE UPPED POPS TO LIKELY
OVER ROUGHLY THE WESTERN HALF OF THE CWA THROUGH 12Z AS LATEST RAP
AND HRRR INDICATE THESE SHOWERS WILL CONTINUE TO STREAM NORTHEAST
INTO EASTERN NORTH CAROLINA. FOR THE REMAINDER OF THE
DAY...ATMOSPHERE REMAINS VERY MOIST WITH PRECIPITABLE WATER VALUES
NEAR 2 INCHES. THIS MOIST BOUNDARY LAYER COUPLED WITH A STALLED
SURFACE BOUNDARY TO THE NORTH AND SOME STRONG H5 VORTICITY
EMBEDDED WITHIN A SOUTHWEST FLOW ALOFT WILL LEAD TO WAVES OF
SHOWERS CONTINUING OVER THE AREA THROUGH THE DAY AND HAVE HIGH CHC
TO LIKELY POPS EVERYWHERE. CLOUDS/PRECIPITATION WILL HOLD TEMPS
DOWN AS WELL WITH MOST MAX TEMPERATURES ONLY INTO THE MIDDLE 80S.
WITH DECENT INSTABILITY...WILL ALSO SEE SOME EMBEDDED
THUNDER...BUT UPPER LEVELS REMAIN WARM AND SHEAR MINIMAL...SO THE
SEVERE THREAT WILL BE LIMITED TODAY. THE PRIMARY THREAT WILL BE
HEAVY RAINFALL AND HAVE THIS WORDING IN THE ZONE FORECAST/GRIDS
TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
AS OF 340 AM TUESDAY...THE AXIS OF THE HEAVIEST RAIN WILL SHIFT
TO THE SOUTH AND EAST TONIGHT TOWARD THE COAST AS ANOTHER STRONG
SHORTWAVE MOVES ALONG THE COAST AND AXIS OF HIGHEST MIXING RATIO
AND SURFACE THETA-E SHIFTS TO THE SOUTH. WILL LIKELY SEE SOME
EMBEDDED THUNDER GIVEN MODERATE INSTABILITY. WILL HAVE LIKELY POPS
OVER THE SOUTHERN HALF OF THE CWA TONIGHT...TAPERING BACK TO HIGH
CHC NORTH. MIN TEMPS WILL BE MOSTLY IN THE LOWER 70S DUE TO THE
RAIN-COOLED AIR.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 330 AM TUE...RAINY PATTERN WILL CONTINUE THROUGH WED WITH
PERIODS OF HEAVY RAIN LOOKING LIKELY...FOLLOWED BY SCATTERED SHOWERS
AND TSTORMS LATE IN THE WEEK.
FRONTAL BOUNDARY WILL REMAIN IN PLACE ACROSS E NC ON WED...AND WITH
UPR STAGNANT TROUGH IN PLACE...DYNAMICS WILL BE IN PLACE FOR ANOTHER
ROUND OF HEAVY RAIN. IN ADDITION...THE AREA WILL BE UNDER RIGHT
ENTRANCE REGION OF DEPARTING JET STREAK...SO LIFT WILL BE ENHANCED
WITH AREA OF STRONG MID LEVEL FGEN IN PLACE. THIS WILL ENHANCE
RAINFALL TOTALS...AND COULD BE A SEVERE TSTORM OR TWO WITH DEEP
LAYER SHEAR IN EXCESS OF 25 KT...THOUGH INSTABILITY WILL BE LIMITED
WITH EXTENSIVE CLOUD COVER AND RAIN. RAIN CHANCES CONFINED TO OUTER
BANKS BY LATE AFTERNOON AS AREA OF LIFT MOVES EASTWARD.
FRONTAL BOUNDARY PROGGED TO BE NEAR OR JUST OFF THE COAST WED
NIGHT...WITH LIKELY POPS CONFINED TO THE IMMEDIATE COAST.
FOR THUR...IT APPEARS A DRIER DAY IS ON TAP WITH A BRIEF RESPITE
FROM THE WIDESPREAD RAIN...AS AREA WILL BE UNDER BROAD SW FLOW...
THOUGH MAJOR FORCING MECHANISM WELL TO THE WEST OF THE AREA.
MED/LONG RANGE MODELS IN GOOD AGREEMENT ON DEEP TROUGH CENTERED OVER
THE GREAT LAKES THUR NIGHT...TRANSLATING EASTWARD TOWARDS CENTRAL
APPALACHIANS FRI NIGHT. THIS WILL BRING ANOTHER ROUND OF WIDESPREAD
SHOWERS THUNDERSTORMS INTO E NC FRI AND SAT. BEST CHANCES ATTM
APPEAR TO BE ON SAT...AS E NC WILL BE UNDER RIGHT ENTRANCE REGION OF
JET STREAK...TRANSLATING TO STRONG UPPER SUPPORT AND MID LEVEL FGEN
ONCE AGAIN. COULD BE A SEVERE TSTORM THREAT AS DEEP LAYER SHEAR WILL
BE PRESENT...AND PROVIDED INSTABILITY IS DECENT.
RAIN CHANCES MAY LINGER INTO LATE THIS WEEKEND THROUGH EARLY NEXT
WEEK...AS THERE ARE INDICATIONS FRONTAL BOUNDARY MAY GET HUNG UP
ACROSS E NC.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
/SHORT TERM TODAY AND TONIGHT/...
AS OF 345 AM WEDNESDAY...WIDESPREAD SHOWERS AND A FEW
THUNDERSTORMS WILL COVER THE AREA TODAY INTO TONIGHT. THERE WILL
BE LIKELY REDUCTIONS TO MVFR CEILINGS AND VSBYS IN THESE NUMEROUS
SHOWERS THROUGHOUT THE TAF PERIOD.
/LONG TERM WEDNESDAY THROUGH SATURDAY/...
AS OF 330 AM TUESDAY...WIDESPREAD RAIN AND THUNDERSTORMS WILL PLAGUE
E NC ON WED...WITH REDUCTIONS IN VSBY/CIG TO IFR POSSIBLE AT TIMES.
MUCH DRIER DAY ON THUR ON TAP...WITH CONDITIONS IMPROVING TO VFR ALL
AREAS. WILL SEE MORE SHOWER ACTIVITY FRI AND SAT...WITH MORE TEMPO
REDUCTIONS TO MVFR OR LOWER POSSIBLE.
&&
.MARINE...
/SHORT TERM TODAY AND TONIGHT/...
AS OF 345 AM TUESDAY...MARINE FORECAST REMAINS STEADY STATE WITH
SW WINDS OF 10 TO 15 KNOTS CONTINUING FOR TODAY AND TONIGHT WITH
SEAS IN THE 2 TO 3 FOOT RANGE. LATEST BUOY OBSERVATIONS SHOWING A
BIT MORE OF A SOUTHEAST SWELL COMPONENT AFFECTING THE NORTHERN
WATERS AT 10 TO 13 SECONDS. WINDS MAY GUST TO 20 KNOTS IN
CONVECTION WITH NUMEROUS SHOWERS AND A FEW TSTMS TODAY...BUT THE
GUSTINESS WILL BE SHORT-LIVED. NO SIGNIFICANT CHANGES TO THE
SHORT TERM FORECAST ARE NEEDED.
/LONG TERM WEDNESDAY THROUGH SATURDAY/...
AS OF 330 AM TUESDAY...SW FLOW WILL PERSIST THROUGH THE LONG TERM...
WITH WINDS 15 TO OCNL 20 KT WED THROUGH FRI. SEAS WILL GRADUALLY
BUILD TOWARDS 6 FEET...REACHING 6 FEET SOMETIME LATE FRIDAY...AS
WINDS REACH 20 TO 25 KT FRI NIGHT THROUGH SAT AS GRADIENT IS PINCHED
WITH AN APPROACHING DEEP TROUGH OF LOW PRES. WINDS AND SEAS DIMINISH
TO BELOW SCA LATE IN THE WEEKEND.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...TL
AVIATION...CTC/TL
MARINE...CTC/TL
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1245 AM EDT TUE AUG 7 2012
.SYNOPSIS...
A STATIONARY FRONT EXTENDING FROM THE MID-ATLANTIC TO THE LOWER
MISSISSIPPI VALLEY WILL REMAIN FOR THE NEXT SEVERAL
DAYS...EVENTUALLY DISSIPATING LATE THIS WEEK. A COLD FRONT WILL
APPROACH FROM THE NORTHWEST FRIDAY AND MOVE THROUGH THE STATE THIS
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1245 AM TUESDAY...BAND OF LIGHT TO MODERATE SHOWERS IS
GRADUALLY DIMINISHING IN COVERAGE ACROSS THE NORTH/NORTHEASTERN
COUNTIES EARLY THIS MORNING. HOWEVER...WITH ADDITIONAL SHORTWAVE
ENERGY APPROACHING FROM THE WEST LATER IN THE NIGHT...THINK SOME
REDEVELOPMENT IS POSSIBLE ACROSS THE NORTHERN COASTAL PLAINS AND
SOUND COUNTIES. AS A RESULT...WILL HAVE HIGH CHC POPS FOR THE NORTHERN
TIER THROUGH THE OVERNIGHT HOURS. ALSO SEEING SHOWERS INCREASING
IN COVERAGE SOUTH OF WILMINGTON AND WILL CARRY CHANCE POPS OVER
THE SOUTHERN COASTAL SECTIONS TOWARD MORNING AS LATEST RAP BRINGS
THIS ACTIVITY INTO THE SOUTHERN CWA. OTHER AREAS WILL BE IN A
SLIGHT CHC POP RANGE THROUGH EARLY MORNING. MIN TEMPERATURES WILL
RANGE IN THE LOWER 70S IN RAIN COOLED AREAS AND 75 TO 80 DEGREES
ELSEWHERE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
AS OF 225 PM MON...WEAK SURFACE LOW OVER THE LOWER GULF STATES
WILL MOVE NORTHEAST ALONG A TROF OF LOW PRESSURE EXTENDING THROUGH
CENTRAL GEORGIA TO CENTRAL NORTH CAROLINA. THIS WILL HELP DEEPEN
THE MOISTURE ACROSS THE AREA. PRECIP WATER VALUES REACH JUST OVER
2.3 INCHES BY TUESDAY AFTERNOON. LIFT WILL INCREASE DURING THE DAY
AIDED BY AN ELONGATED VORT LOBE IN THE MID LEVELS APPROACHING FROM
THE WEST. LIKELY POPS ACROSS THE WEST AND NORTH WITH 40-50 PERCENT
ELSEWHERE. HIGHS GENERALLY IN THE MID 80S THROUGHOUT DUE TO
INCREASED CLOUD COVER AND CONVECTION.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
AS OF 225 PM MONDAY...WILL REMAIN UNSETTLED FOR MUCH OF THIS
PERIOD. WEAK UPR TRF TO THE NW COMBINED WITH AXIS OF DEEP MOISTURE
OVER ERN NC WILL LEAD TO SCT TO NUMEROUS SHRA AND TSRA TUE NIGHT
INTO THU. WILL HAVE HIGH CHC TO LIKELY POPS MUCH OF THE PERIOD.
SHEAR ALOFT REMAINS WEAK AND THIS SHLD LIMIT THE SEVERE THREAT.
MUCH STRONGER UPR TRF WILL APPROACH FRI INTO SAT WITH BETTER SHEAR
AND GREATER THREAT OF SEVERE. FOR NOW WILL CONT CHC POP FOR LATE
IN THE WEEK....LATER SHIFTS MAY BE ABLE TO ADJUST UP AS TIMING OF
FEATURES BECOMES CLEARER. MAY GET A BRIEF LULL IN PRECIP SUNDAY AS
ECMWF SHOWS SOME DRIER AIR SPREADING IN AS WEAKENING FRONT MAKES
IT TO CST. UPR TRF NEVER PUSHES THRU AND LOOKS LIKE MOISTURE AND
SCT SHRA/TSRA WILL RETURN EARLY NEXT WEEK. CLOUDS AND PRECIP SHLD
KEEP HIGH TEMPS IN THE 80S WITH LOWS MAINLY IN THE 70S THRU THE
PD. EXPECT MANY AREAS WILL RECEIVE 2+ INCHES OF RAINFALL THRU THE
LONG TERM FCST.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
SHORT TERM /TONIGHT AND TUE/
AS OF 1030 PM MON...HIGH PRES OFF THE SE COAST CONTINUES TO BRING
MOIST S/SWLY FLOW ACROSS RTES THROUGH THE TAF PERIOD WHILE A
FRONTAL BOUNDARY REMAINS STALLED ACROSS THE MID ATLANTIC TO THE
DEEP SOUTH. HEAVIEST CONVECTION HAS WANED LATE THIS EVENING WITH
HEAVIEST SHOWERS AND TSTMS ACROSS NERN RTES WITH LIMITED IMPACT AT
THE TERMINALS...ALTHOUGH COULD SEE AN ISOLATED SHOWER AT PGV OVER
THE COUPLE HOURS. AN UPPER LEVEL WAVE IS PROGGED BY SEVERAL
MODELS TO IMPACT THE REGION LATE TONIGHT WHICH COULD SERVE TO
INITIATE ADDITIONAL CONVECTION DURING THE PRE-DAWN HOURS. A MOIST
AND UNSTABLE AIRMASS PERSISTS TUE AND EXPECT SCATTERED TO NUMEROUS
SHOWERS ACROSS ERN NC. OUTSIDE OF CONVECTION FLIGHT CONDITIONS
EXPECTED TO PRIMARILY BE VFR BUT COULD SEE PATCHY FOG DEVELOP LATE
TONIGHT BRIEFLY LOWERING CIGS.
LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 225 PM MONDAY...SCT TO NUMEROUS SHRA AND TSRA WILL CONT THRU
THE PERIOD WITH BRIEF REDUCTIONS IN CIGS/VSBYS AS CONVECTION
CROSSES TAF SITES. SATURATED LOW LVLS WILL LIKELY LEAD TO SOME
LATE NIGHT AND MORN STRATUS AND FOG WITH PDS OF MVFR/IFR.
&&
.MARINE...
SHORT TERM /TONIGHT AND TUE/
AS OF 1245 AM TUESDAY...HAVE TONED DOWN WINDS A BIT AS CONVECTION
HAS WEAKENED OVER THE NORTHERN WATERS. MOST AREAS WILL HAVE SW
WINDS OF 10 TO 15 KNOTS OVERNIGHT WITH SEAS RIGHT AROUND 3 FEET. A
RATHER STAGNANT PATTERN WILL CONTINUE IN THE SHORT TERM WITH A
STATIONARY FRONT EXTENDING FROM THE MID-ATLANTIC TO THE LOWER
MISSISSIPPI VALLEY...AND THE BERMUDA HIGH OFFSHORE.
LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 225 PM MONDAY...FAIRLY QUITE TUE NIGHT INTO THU MORN WITH
S/SW WINDS 15 KTS OR LESS AND SEAS 2 TO 4 FT. SW WINDS WILL BE
INCREASING LATER THU AND ESPCLY FRI AS COLD FRONT
APPROACHES...LOOKS LIKE WINDS OF 15 TO 25 KTS FRI WITH SEAS
REACHING 6 FT OR MORE OVER MUCH OF THE OUTER WTRS FRI INTO EARLY
SAT. GRDNT WILL LOOSEN SAT AS FRONT GETS CLOSER AND BEGINS TO
WEAKEN...THIS WILL LEAD TO DIMINISHING SW WINDS AND SEAS SUBSIDING
TO 3 TO 5 FT SAT AFTN.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...HSA
NEAR TERM...CTC
SHORT TERM...HSA
LONG TERM...RF/HSA
AVIATION...RF/SK
MARINE...CTC/RF/SK
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1125 PM CDT MON AUG 6 2012
.DISCUSSION...
SEE 06Z AVIATION DISCUSSION BELOW.
&&
.AVIATION...
VFR CONDITIONS ARE EXPECTED AT THE TERMINALS THE NEXT 24 HOURS.
ISOLD TSTMS ARE POSSIBLE ACROSS ACROSS MUCH OF WEST CENTRAL TEXAS
AFTER 20Z TUE...HOWEVER WILL KEEP TSTMS OUT OF THE TERMINALS DUE
TO VERY SPARSE COVERAGE.
21
&&
.PREV DISCUSSION... /ISSUED 953 PM CDT MON AUG 6 2012/
UPDATE...
WEAKENING CONVECTION HAS MOVED INTO THE NORTHEAST PORTION OF THE
CWA NEAR THROCKMORTON AND WILL CONTINUE ITS DOWNWARD TREND AS IT
MOVES SSW. ADDITIONAL...MORE IMPRESSIVE...STORMS EXIST ALONG THE
I-35 CORRIDOR FORMING JUST NORTH OF THE RED RIVER NEAR THE
INTERSECTION OF THE LOW LEVEL JET AND A QUASI-STATIONARY SURFACE
FRONT. HOWEVER...THESE STORMS WILL MOVE GENERALLY SOUTH AND SHOULD
REMAIN TO THE EAST OF THE CWA. THE HRRR MAINTAINS THE CONVECTION
OVER THROCKMORTON COUNTY WELL INTO THE NORTHERN CONCHO VALLEY BUT
OTHER 3 KM WRF VARIETIES WEAKEN THIS CONVECTION OVER THE NEXT 1-2
HOURS. GIVEN THE PERSISTENCE OF LAST NIGHTS ACTIVITY...I HAVE
KEPT MENTION OF THUNDERSTORMS FOR THE BIG COUNTRY THROUGH 09Z WITH
DRY CONDITIONS THEREAFTER. I ALSO LOWERED MIN TEMPS JUST A BIT...
SHADING CLOSER TO WHAT WAS OBSERVED THIS MORNING WITH A SLIGHT
MODEL BLEND BUILT IN. GENERALLY LOW/MID 70S ARE EXPECTED ACROSS
THE CWA.
JOHNSON
PREV DISCUSSION... /ISSUED 350 PM CDT MON AUG 6 2012/
SHORT TERM...
LITTLE CHANGE TO FORECAST REASONING THE NEXT 24 HOURS. WEST
CENTRAL TEXAS WILL REMAIN ON THE EASTERN PERIPHERY OF THE UPPER
HIGH THAT WILL BE CENTERED OVER THE FOUR CORNERS REGION THE REST
OF THIS WEEK. WATER VAPOR IMAGERY ALREADY SHOWING BETTER MID
LEVEL MOISTURE ACROSS ACROSS THE AREA COMPARED TO THE PAST COUPLE
OF DAYS. THE INCREASE IN MOISTURE COUPLED WITH STRONG DAYTIME
HEATING WILL ALLOW FOR ISOLATED TO WIDELY SCATTERED SHOWERS AND
THUNDERSTORMS LATE THIS AFTERNOON AND EVENING AND AGAIN TUESDAY
AFTERNOON. THE BEST CHANCE FOR STORMS THROUGH THIS EVENING WILL
BE ACROSS THE BIG COUNTRY WHERE 20 POPS WERE ADDED.
OTHERWISE...WENT WITH ISOLATED WORDING ELSEWHERE THROUGH THE
EVENING HOURS.
SIMILAR SCENARIO FOR TUESDAY WITH BEST CHANCE FOR ISOLATED
CONVECTION ACROSS THE BIG COUNTRY TUESDAY AFTERNOON. TEMPERATURES
ON TUESDAY WILL BE SIMILAR TO TODAY WITH AFTERNOON HIGHS
GENERALLY A COUPLE OF DEGREES EITHER SIDE OF THE CENTURY MARK.
LONG TERM...
WEST CENTRAL TEXAS WILL BE THE EASTERN SIDE OF THE UPPER RIDGE
INTO NEXT WEEKEND...WITH NORTHERLY FLOW ALOFT. ISOLATED
THUNDERSTORMS WILL CONTINUE TO BE POSSIBLE...WEDNESDAY INTO
THURSDAY...BUT BEST CHANCE OF A THUNDERSTORM WILL BE WEDNESDAY
NIGHT AS GFS MODEL BRINGS A WEAK COLD FRONT THROUGH THE REGION.
MAY STAY 2-3 DEGREES LESS HOT THURSDAY INTO SATURDAY...BUT UPPER
RIDGE/850 MB THERMAL TROUGH STRENGTHENS AGAIN SUNDAY INTO EARLY
NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 76 101 76 102 75 / 10 20 10 20 20
SAN ANGELO 74 102 75 102 73 / 5 10 10 20 20
JUNCTION 72 98 73 102 74 / 5 10 10 10 20
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
305 AM CDT TUE AUG 7 2012
.SHORT TERM...TODAY THROUGH THURSDAY NIGHT
305 AM CDT TUE AUG 7 2012
MAIN CONCERN DEALS WITH FRONTAL PASSAGE THIS MORNING ALONG WITH ANY
SHOWER/THUNDER CHANCES...THEN SHOWER/THUNDER CHANCES AGAIN WEDNESDAY
THROUGH THURSDAY EVENING.
CURRENTLY MONITORING A COLD FRONT MOVING SOUTH ACROSS UPPER
MI/NORTHERN WI. RADAR SHOWING MAIN SHRA/TS ACTIVITY CONFINED ACROSS
NORTHEAST WI THROUGH CENTRAL/EASTERN UPPER MICHIGAN. OTHERWISE...
SKIES AT 3 AM WERE MOSTLY CLEAR ACROSS THE AREA WITH TEMPERATURES
RANGING FROM THE UPPER 50S TO MIDDLE 60S.
07.00Z MODELS IN VERY GOOD AGREEMENT THROUGH THE SHORT TERM WITH
HANDLING OF OVERALL SYNOPTIC PATTERN.
FOR TODAY...WILL BE WATCHING THAT COLD FRONT CONTINUE MOVING SOUTH
THROUGH THE AREA...EXITING BY NOON. MODEL SOUNDINGS SHOWING VERY
HIGH-BASED ACCAS ASSOCIATED WITH THE FRONT AS IT PASSES
THROUGH...LENDING TO EVAPORATION BEFORE THE RAIN REACHES THE GROUND.
WILL CONTINUE A SLIGHT CHANCE OF SHRA/TS THIS MORNING SOUTH OF A
RICHLAND CENTER/PRAIRIE DU CHIEN WI...TO CHARLES CITY IA LINE WHERE
BETTER 850MB MOISTURE TRANSPORT/CONVERGENCE WILL RESIDE.
OTHERWISE...PLAN ON DRYING THIS AFTERNOON AS THE FRONT SLIPS SOUTH
OF THE AREA AND HIGH PRESSURE BUILDS SOUTH OUT OF MN. HIGHS TODAY
ARE EXPECTED TO BE IN THE 80S.
MOSTLY CLEAR SKIES THIS EVENING WILL GIVE WAY TO INCREASING MID/HIGH
CLOUDS LATE TONIGHT AHEAD OF AN APPROACHING MID-LEVEL SHORTWAVE
TROUGH DROPPING SOUTHEAST THROUGH THE DAKOTAS. APPEARS ANY SHRA/TS
ACTIVITY WILL STAY WEST OF THE AREA AS DRIER AIR ASSOCIATED WITH THE
HIGH HOLDS IN PLACE OVER THE FORECAST AREA.
FOR WEDNESDAY THROUGH THURSDAY WILL BE WATCHING THE MID-LEVEL
SHORTWAVE TROUGH MOVE SOUTHEAST INTO THE AREA WHILE A DEEPER/MORE
VIGOROUS TROUGH ROTATES SOUTH OUT OF CANADA. COLDER/CYCLONIC FLOW
ALOFT WILL COMBINE WITH DAYTIME SURFACE HEATING TO PRODUCE 0-3KM
MUCAPE IN THE 500-1000J/KG FOR SHRA/TS CHANCES. WITH CLOUD
COVER/SCATTERED CONVECTION/COLD AIR ALOFT...PLAN ON TEMPERATURES
THURSDAY ONLY TOPPING OFF IN THE UPPER 60S TO MIDDLE 70S. LOOK FOR
THE TROUGH TO ROTATE SOUTHEAST OF THE AREA THURSDAY NIGHT BRINGING
AN END TO SHRA/TS CHANCES.
.LONG TERM...FRIDAY THROUGH MONDAY
305 AM CDT TUE AUG 7 2012
LATEST GFS/ECMWF SHOW A RIDGE OF HIGH PRESSURE BUILDING INTO THE AREA
ON FRIDAY...HOLDING THROUGH SATURDAY FOR A BOUT OF QUIET/DRY WEATHER
WITH HIGH TEMPERATURES IN THE 70S. MODELS SHOW A WEAK MID-LEVEL WAVE
COMING THROUGH THE RIDGE ON SUNDAY. THIS IS EXPECTED TO SPREAD A FEW
CLOUDS INTO THE AREA...BUT EXPECTED TO REMAIN DRY. GFS/ECMWF THEN
SHOW SOME DIFFERENCES ON MONDAY WITH THE GFS WANTING TO BRING
ANOTHER MID-LEVEL WAVE FARTHER SOUTH INTO THE AREA WHILE THE ECMWF
IS MUCH WEAKER AND FARTHER NORTH INTO CANADA. CONSENSUS OF THE MODEL
YIELDS A DRY MONDAY WITH HIGHS IN THE UPPER 70S TO LOWER 80S.
&&
.AVIATION...THROUGH 18Z TUESDAY
1100 PM CDT MON AUG 6 2012
VERY DRY 00Z SOUNDINGS FROM MSP/GRB/DVN...WITH LITTLE TO NO CLOUDS
INDICATED IN THE VICINITY FROM LATEST CLOUD/STRATUS SATELLITE
IMAGERY. OTHER THEN A FEW MID LEVEL CLOUDS...THE BULK OF WHAT WAS
OUT THERE WAS CONFINED AROUND A FRONTAL BOUNDARY ACROSS NORTHEAST
MN/UP OF MICH. RAP STILL ADAMANT WITH ABOUT 1000 J/KG OF MLCAPE
ACROSS THE AREA FOR MUCH OF THE OVERNIGHT...WITH SOME FRONTOGENETIC
FORCING...AND A GOOD PUSH OF 925 MB MOISTURE ADVECTION. THAT FRONT
TO THE NORTH WILL DROP SOUTH OVERNIGHT...LIKELY SLIPPING SOUTH OF
KRST/KLSE AROUND 12Z...AND THERE IS A WEAK SHORTWAVE MAKING ITS WAY
SOUTHEAST ACROSS THE REGION. SO...THERE ARE FORCING MECHANISMS...BUT
SATURATION PER THE SOUNDINGS AND FORECAST RH FIELDS/BUFKIT SOUNDINGS
PRETTY MEAGER. IF SHRA/TS WOULD DEVELOP...BASES WOULD PROBABLY BE
AOA 8 KFT. CONFIDENCE LOW ENOUGH THAT I HAVE REMOVED THE VCSH FROM
THE TAFS. IF THEY DO DEVELOP...DON/T BELIEVE THERE WOULD BE ANY
CIG/VSBY IMPACT. PERHAPS SOME GUSTINESS.
AS FOR VSBY...WITH SKIES MORE SKC/SCT OVERNIGHT AND THE SFC WIND
FIELD VRB/CALM ACROSS MUCH OF THE AREA...RIVER VALLEY FOG IS A
CONCERN. T/TD SPREAD THE SAME AS YESTERDAY AT 03Z AT KLSE...8
DEGREES. WINDS AREN/T PROGGED TO BE AS LIGHT OFF THE SFC
THOUGH...WITH RAP/NAM12 BUFKIT SOUNDINGS AROUND 10-15 KTS BY 200-400
HUNDRED FEET. TDS HAVE CONTINUED TO CLIMB THIS EVENING...AND MIGHT
GET ANOTHER 1-2 DEGREE RISE. THIS COULD BE ALL THAT IS NEEDED FOR
IFR FG AT KLSE. HAVE DECIDE TO TREND THE FORECAST MUCH LIKE MONDAY
MORNING...WITH 2SM...AND BCFG TO COVER THE PATCHES OF MORE DENSE
FOG. CONDITIONS WILL BE MONITORED AND ADJUSTMENTS MADE AS A
NEEDED.
WITH THE FRONT SLIDING THROUGH EARLY TUE MORNING...WINDS WILL SWITCH
TO THE NORTHWEST. HIGH PRESSURE WILL FOLLOW IN ITS WAKE...WITH QUIET
VFR CONDITIONS THEN INTO TUE NIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
305 AM CDT TUE AUG 7 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
850 AM MST TUE AUG 7 2012
.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL OVER THE DESERT SOUTHWEST THIS
WEEK...RESULTING IN WELL ABOVE NORMAL TEMPERATURES AND PERIODS OF
EXCESSIVE HEAT. THUNDERSTORM CHANCES WILL BE FOCUSED MAINLY OVER
HIGHER TERRAIN OF NORTHERN AND EASTERN ARIZONA TODAY...THOUGH THERE
WILL BE A CHANCE OF STORMS WEDNESDAY AND THURSDAY ACROSS
SOUTH-CENTRAL ARIZONA. THE WELL ABOVE NORMAL TEMPERATURES WILL
PERSIST THROUGH AT LEAST THE WEEKEND ALONG WITH BELOW NORMAL CHANCES
FOR RAIN AND THUNDERSTORMS.
&&
.DISCUSSION...
CURRENT FORECAST STILL IN GOOD SHAPE AS HOT TEMPERATURES WILL BE THE
DOMINANT FEATURE TODAY AND THROUGH THE REST OF THE WEEK. THE VORT
MAX OVER NORTHWEST SONORA MEXICO CONTINUES TO TRACK WEST NORTHWEST
JUST SOUTH OF ARIZONA. A FEW ISOLATED SHOWERS ON THE NORTH SIDE OF
THE VORT MAX WILL STILL BE POSSIBLE ACROSS SOUTHERN YUMA COUNTY
THROUGH THE REST OF THE MORNING...BUT LIKELY ONLY RESULTING IN
SPRINKLES OR NON-MEASURABLE AMOUNTS. ADDITIONAL DEVELOPMENT WILL BE
POSSIBLE THROUGH THE REST OF TODAY ASSOCIATED WITH THIS
FEATURE...BUT THE LOW END SLIGHT CHANCE IN PORTIONS OF FAR SOUTHEAST
CALIFORNIA STILL LOOKS REASONABLE. MAY HAVE TO INCREASE THE COVERAGE
OF SLIGHT CHANCE POPS IF DEVELOPMENT BECOMES MORE ACTIVE LATER
TODAY. ELSEWHERE...STORMS CHANCES ARE LOWER THAN YESTERDAY WITH
DECREASING MOISTURE. PRECIPITABLE WATER VALUES DROP TO AROUND 1 INCH
OR EVEN SLIGHTLY BELOW AN INCH ACROSS EASTERN ARIZONA...SO NOT
EXPECTING ACTIVE STORM DEVELOPMENT ACROSS THE HIGHER TERRAIN EAST OF
PHOENIX. ANY SHOWERS OR THUNDERSTORMS THAT DO DEVELOP WILL LIKELY BE
LIMITED AND STAY WELL EAST OF THE VALLEY.
&&
.PREVIOUS DISCUSSION...
LATEST WV IMAGERY SHOWS A COMPACT VORT MAX MOVING STEADILY WESTWARD
ACROSS NORTHERN SONORA WHILE ISOLATED THUNDERSTORMS HAVE PERSISTED
EARLY THIS MORNING ACROSS PIMA COUNTY. MODELS HAVE HAD A DIFFICULT
TIME INITIALIZING THE TROUGH...THOUGH THE LATEST HRRR SUGGESTS
ISOLATED CONVECTION WILL REMAIN A THREAT THROUGH THE DAY FROM YUMA
INTO THE IMPERIAL VALLEY. A WEAK BOUNDARY IS EVIDENT ON IR SATELLITE
AND IT SEEMS REASONABLE THAT ISOLATED CELLS COULD DEVELOP ALONG AND
AHEAD OF THIS FEATURE. FURTHER EAST ACROSS SOUTH-CENTRAL
AZ...EXCESSIVE HEAT WILL BE THE MAIN STORY AS A STRONG ANTICYCLONE
IN NM DRIFTS WESTWARD AND INTO NORTHERN AZ BY THIS AFTERNOON.
INCREASING NVA AND WEAK SUBSIDENCE WILL GENERALLY PRECLUDE
CONVECTION ACROSS THE LOWER DESERTS. STEERING FLOW REMAINS WEAK AND
ISOLATED THUNDERSTORMS ARE AGAIN EXPECTED TO REMAIN CONFINED TO THE
HIGHER ELEVATIONS OF GILA COUNTY. TEMPERATURES WERE WEIGHTED HEAVILY
TOWARDS THE ECMWF...WHICH HAS PERFORMED WELL RECENTLY AND TENDS TO
DO A BETTER JOB WITH EXCESSIVE HEAT EVENTS. RECORD HIGH TEMPERATURE
FOR TODAY IN PHOENIX IS 112 DEGREES...SET IN 1905...AND IS IN
JEOPARDY OF BEING TIED OR EVEN BROKEN THIS AFTERNOON.
CENTER OF THE ANTICYCLONE WILL MOVE INTO UT WEDNESDAY. THIS WILL
PRODUCE A WEAK NORTHEASTERLY FLOW WHICH WILL INCREASE DOWNSLOPING
AND ADIABATIC WARMING. TEMPERATURES ARE EXPECTED TO BE 1 TO 3
DEGREES WARMER THAN THOSE TUESDAY AND THE RECORD HIGH TEMPERATURE OF
113 DEGREES IN PHOENIX IS AGAIN IN JEOPARDY OF BEING ECLIPSED.
TEMPERATURES WILL BE EVEN WARMER ACROSS SW AZ AND SE CA AND THE
EXCESSIVE HEAT WATCH HAS BEEN UPGRADED TO A WARNING IN THESE AREAS.
LATEST SREF SHOWS DEEPER MOISTURE CURRENTLY ACROSS THE SOUTHERN
ROCKIES WHICH IS EXPECTED TO REACH EASTERN AZ WED EVENING. SCATTERED
THUNDERSTORMS WILL HAVE THE POTENTIAL TO PROPAGATE OUT OF GILA
COUNTY AND INTO THE LOWER ELEVATIONS WEDNESDAY NIGHT. AT THE VERY
LEAST...BLOWING DUST WILL BE A THREAT ACROSS THE PHOENIX METRO AREA
AND INTO PINAL COUNTY.
EASTERLY FLOW WILL STRENGTHEN THURSDAY AS THE HIGH BECOMES
POSITIONED NEAR THE FOUR CORNERS. DRIER AIR WILL SHIFT WESTWARD AND
THERE IS INCREASING UNCERTAINTY WITH REGARD TO THE EXCESSIVE HEAT.
IT IS CONCEIVABLE THAT THURSDAY WILL BE COOLER IF AN OUTFLOW
BOUNDARY MOVES THROUGH WEDNESDAY NIGHT. AT THIS POINT...THE WATCH
WILL BE EXTENDED ONLY FOR SW AZ AND SE CA.
THE ANOMALOUS HIGH WILL PERSIST INTO EARLY NEXT WEEK. GFS/ECMWF IN
GOOD AGREEMENT THAT DRIER AIR WILL EVENTUALLY BE ADVECTED WESTWARD.
ANOTHER STRETCH OF EXCESSIVE HEAT IS LIKELY ALONG WITH BELOW AVERAGE
RAIN CHANCES.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
FEW-SCT MID-HIGH LEVEL CLOUDS...ALONG WITH WINDS AROUND 10KT OR LESS
TO PREVAIL INTO WEDNESDAY MORNING. AFTN/EVE THUNDERSTORM ACTIVITY
WILL BE ISOLATED AT BEST...MAINLY CONFINED TO THE MOGOLLON RIM...
WHITE MOUNTAINS...SOUTHEAST ARIZONA.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
WEAK DISTURBANCE COULD BRING INCREASING MID LEVEL CLOUD DECKS OVER
THE AREA THIS MORNING ALONG WITH AN ISOLATED THUNDERSTORM...HOWEVER
CONFIDENCE TOO LOW TO MENTION CONVECTION IN TAFS AT THIS TIME.
OTHERWISE...MOSTLY SUNNY/CLEAR SKIES AND LIGHT WINDS EXPECTED THIS
AFTERNOON INTO WEDNESDAY MORNING.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
STRONG UPPER LEVEL HIGH PRESSURE WILL REMAIN OVER THE REGION INTO
THE WEEKEND. AS A RESULT...ABOVE NORMAL/VERY HOT TEMPERATURES AND
DAYTIME RELATIVE HUMIDITY VALUES IN THE TEENS ARE EXPECTED THROUGH
THE PERIOD. SUFFICIENT MOISTURE AND INSTABILITY OVER THE MOUNTAINS
OF SOUTH-CENTRAL ARIZONA WILL PROVIDE A DAILY THREAT OF AFTERNOON
AND EVENING THUNDERSTORMS...AND OCCASIONALLY A FEW STORMS COULD
PROPAGATE INTO THE LOWER DESERT ELEVATIONS. ANY WETTING RAINFALL
EVENTS WILL BE ISOLATED AND SPORADIC. OUTSIDE OF STRONG GUSTY WINDS
ASSOCIATED WITH STORMS...LIGHT WINDS EXPECTED THROUGH THE PERIOD.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...EXCESSIVE HEAT WARNING UNTIL 8 PM MST WEDNESDAY
AZZ022-023-027-028.
EXCESSIVE HEAT WARNING FROM 10 AM TO 8 PM MST WEDNESDAY
AZZ020-021-025-026.
EXCESSIVE HEAT WATCH FROM WEDNESDAY EVENING THROUGH FRIDAY
EVENING AZZ020-021-025-026.
CA...EXCESSIVE HEAT WARNING FROM 10 AM TO 8 PM PDT WEDNESDAY
CAZ031>033.
EXCESSIVE HEAT WATCH FROM WEDNESDAY EVENING THROUGH FRIDAY
EVENING CAZ031>033.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...KUHLMAN
PREVIOUS DISCUSSION...HIRSCH
AVIATION...MEYERS
FIRE WEATHER...MO/MEYERS
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
513 AM MST TUE AUG 7 2012
.UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS.
&&
.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL OVER THE DESERT SOUTHWEST THIS
WEEK...RESULTING IN WELL ABOVE NORMAL TEMPERATURES AND PERIODS OF
EXCESSIVE HEAT. THUNDERSTORM CHANCES WILL BE FOCUSED MAINLY OVER
HIGHER TERRAIN OF NORTHERN AND EASTERN ARIZONA TODAY...THOUGH THERE
WILL BE A CHANCE OF STORMS WEDNESDAY AND THURSDAY ACROSS
SOUTH-CENTRAL ARIZONA. THE WELL ABOVE NORMAL TEMPERATURES WILL
PERSIST THROUGH AT LEAST THE WEEKEND ALONG WITH BELOW NORMAL CHANCES
FOR RAIN AND THUNDERSTORMS.
&&
.DISCUSSION...
LATEST WV IMAGERY SHOWS A COMPACT VORT MAX MOVING STEADILY WESTWARD
ACROSS NORTHERN SONORA WHILE ISOLATED THUNDERSTORMS HAVE PERSISTED
EARLY THIS MORNING ACROSS PIMA COUNTY. MODELS HAVE HAD A DIFFICULT
TIME INITIALIZING THE TROUGH...THOUGH THE LATEST HRRR SUGGESTS
ISOLATED CONVECTION WILL REMAIN A THREAT THROUGH THE DAY FROM YUMA
INTO THE IMPERIAL VALLEY. A WEAK BOUNDARY IS EVIDENT ON IR SATELLITE
AND IT SEEMS REASONABLE THAT ISOLATED CELLS COULD DEVELOP ALONG AND
AHEAD OF THIS FEATURE. FURTHER EAST ACROSS SOUTH-CENTRAL
AZ...EXCESSIVE HEAT WILL BE THE MAIN STORY AS A STRONG ANTICYCLONE
IN NM DRIFTS WESTWARD AND INTO NORTHERN AZ BY THIS AFTERNOON.
INCREASING NVA AND WEAK SUBSIDENCE WILL GENERALLY PRECLUDE
CONVECTION ACROSS THE LOWER DESERTS. STEERING FLOW REMAINS WEAK AND
ISOLATED THUNDERSTORMS ARE AGAIN EXPECTED TO REMAIN CONFINED TO THE
HIGHER ELEVATIONS OF GILA COUNTY. TEMPERATURES WERE WEIGHTED HEAVILY
TOWARDS THE ECMWF...WHICH HAS PERFORMED WELL RECENTLY AND TENDS TO
DO A BETTER JOB WITH EXCESSIVE HEAT EVENTS. RECORD HIGH TEMPERATURE
FOR TODAY IN PHOENIX IS 112 DEGREES...SET IN 1905...AND IS IN
JEOPARDY OF BEING TIED OR EVEN BROKEN THIS AFTERNOON.
CENTER OF THE ANTICYCLONE WILL MOVE INTO UT WEDNESDAY. THIS WILL
PRODUCE A WEAK NORTHEASTERLY FLOW WHICH WILL INCREASE DOWNSLOPING
AND ADIABATIC WARMING. TEMPERATURES ARE EXPECTED TO BE 1 TO 3
DEGREES WARMER THAN THOSE TUESDAY AND THE RECORD HIGH TEMPERATURE OF
113 DEGREES IN PHOENIX IS AGAIN IN JEOPARDY OF BEING ECLIPSED.
TEMPERATURES WILL BE EVEN WARMER ACROSS SW AZ AND SE CA AND THE
EXCESSIVE HEAT WATCH HAS BEEN UPGRADED TO A WARNING IN THESE AREAS.
LATEST SREF SHOWS DEEPER MOISTURE CURRENTLY ACROSS THE SOUTHERN
ROCKIES WHICH IS EXPECTED TO REACH EASTERN AZ WED EVENING. SCATTERED
THUNDERSTORMS WILL HAVE THE POTENTIAL TO PROPAGATE OUT OF GILA
COUNTY AND INTO THE LOWER ELEVATIONS WEDNESDAY NIGHT. AT THE VERY
LEAST...BLOWING DUST WILL BE A THREAT ACROSS THE PHOENIX METRO AREA
AND INTO PINAL COUNTY.
EASTERLY FLOW WILL STRENGTHEN THURSDAY AS THE HIGH BECOMES
POSITIONED NEAR THE FOUR CORNERS. DRIER AIR WILL SHIFT WESTWARD AND
THERE IS INCREASING UNCERTAINTY WITH REGARD TO THE EXCESSIVE HEAT.
IT IS CONCEIVABLE THAT THURSDAY WILL BE COOLER IF AN OUTFLOW
BOUNDARY MOVES THROUGH WEDNESDAY NIGHT. AT THIS POINT...THE WATCH
WILL BE EXTENDED ONLY FOR SW AZ AND SE CA.
THE ANOMALOUS HIGH WILL PERSIST INTO EARLY NEXT WEEK. GFS/ECMWF IN
GOOD AGREEMENT THAT DRIER AIR WILL EVENTUALLY BE ADVECTED WESTWARD.
ANOTHER STRETCH OF EXCESSIVE HEAT IS LIKELY ALONG WITH BELOW AVERAGE
RAIN CHANCES.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
FEW-SCT MID-HIGH LEVEL CLOUDS...ALONG WITH WINDS AROUND 10KT OR LESS
TO PREVAIL INTO WEDNESDAY MORNING. AFTN/EVE THUNDERSTORM ACTIVITY
WILL BE ISOLATED AT BEST...MAINLY CONFINED TO THE MOGOLLON RIM...
WHITE MOUNTAINS...SOUTHEAST ARIZONA.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
WEAK DISTURBANCE COULD BRING INCREASING MID LEVEL CLOUD DECKS OVER
THE AREA THIS MORNING ALONG WITH AN ISOLATED THUNDERSTORM...HOWEVER
CONFIDENCE TOO LOW TO MENTION CONVECTION IN TAFS AT THIS TIME.
OTHERWISE...MOSTLY SUNNY/CLEAR SKIES AND LIGHT WINDS EXPECTED THIS
AFTERNOON INTO WEDNESDAY MORNING.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
STRONG UPPER LEVEL HIGH PRESSURE WILL REMAIN OVER THE REGION INTO
THE WEEKEND. AS A RESULT...ABOVE NORMAL/VERY HOT TEMPERATURES AND
DAYTIME RELATIVE HUMIDITY VALUES IN THE TEENS ARE EXPECTED THROUGH
THE PERIOD. SUFFICIENT MOISTURE AND INSTABILITY OVER THE MOUNTAINS
OF SOUTH-CENTRAL ARIZONA WILL PROVIDE A DAILY THREAT OF AFTERNOON
AND EVENING THUNDERSTORMS...AND OCCASIONALLY A FEW STORMS COULD
PROPAGATE INTO THE LOWER DESERT ELEVATIONS. ANY WETTING RAINFALL
EVENTS WILL BE ISOLATED AND SPORADIC. OUTSIDE OF STRONG GUSTY WINDS
ASSOCIATED WITH STORMS...LIGHT WINDS EXPECTED THROUGH THE PERIOD.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...EXCESSIVE HEAT WARNING UNTIL 8 PM MST WEDNESDAY
AZZ022-023-027-028.
EXCESSIVE HEAT WARNING FROM 10 AM TO 8 PM MST WEDNESDAY
AZZ020-021-025-026.
EXCESSIVE HEAT WATCH FROM WEDNESDAY EVENING THROUGH FRIDAY
EVENING AZZ020-021-025-026.
CA...EXCESSIVE HEAT WARNING FROM 10 AM TO 8 PM PDT WEDNESDAY
CAZ031>033.
EXCESSIVE HEAT WATCH FROM WEDNESDAY EVENING THROUGH FRIDAY
EVENING CAZ031>033.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
AVIATION...MEYERS
FIRE WEATHER...MO/MEYERS
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
350 AM MST TUE AUG 7 2012
.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL OVER THE DESERT SOUTHWEST THIS
WEEK...RESULTING IN WELL ABOVE NORMAL TEMPERATURES AND PERIODS OF
EXCESSIVE HEAT. THUNDERSTORM CHANCES WILL BE FOCUSED MAINLY OVER
HIGHER TERRAIN OF NORTHERN AND EASTERN ARIZONA TODAY...THOUGH THERE
WILL BE A CHANCE OF STORMS WEDNESDAY AND THURSDAY ACROSS
SOUTH-CENTRAL ARIZONA. THE WELL ABOVE NORMAL TEMPERATURES WILL
PERSIST THROUGH AT LEAST THE WEEKEND ALONG WITH BELOW NORMAL CHANCES
FOR RAIN AND THUNDERSTORMS.
&&
.DISCUSSION...
LATEST WV IMAGERY SHOWS A COMPACT VORT MAX MOVING STEADILY WESTWARD
ACROSS NORTHERN SONORA WHILE ISOLATED THUNDERSTORMS HAVE PERSISTED
EARLY THIS MORNING ACROSS PIMA COUNTY. MODELS HAVE HAD A DIFFICULT
TIME INITIALIZING THE TROUGH...THOUGH THE LATEST HRRR SUGGESTS
ISOLATED CONVECTION WILL REMAIN A THREAT THROUGH THE DAY FROM YUMA
INTO THE IMPERIAL VALLEY. A WEAK BOUNDARY IS EVIDENT ON IR SATELLITE
AND IT SEEMS REASONABLE THAT ISOLATED CELLS COULD DEVELOP ALONG AND
AHEAD OF THIS FEATURE. FURTHER EAST ACROSS SOUTH-CENTRAL
AZ...EXCESSIVE HEAT WILL BE THE MAIN STORY AS A STRONG ANTICYCLONE
IN NM DRIFTS WESTWARD AND INTO NORTHERN AZ BY THIS AFTERNOON.
INCREASING NVA AND WEAK SUBSIDENCE WILL GENERALLY PRECLUDE
CONVECTION ACROSS THE LOWER DESERTS. STEERING FLOW REMAINS WEAK AND
ISOLATED THUNDERSTORMS ARE AGAIN EXPECTED TO REMAIN CONFINED TO THE
HIGHER ELEVATIONS OF GILA COUNTY. TEMPERATURES WERE WEIGHTED HEAVILY
TOWARDS THE ECMWF...WHICH HAS PERFORMED WELL RECENTLY AND TENDS TO
DO A BETTER JOB WITH EXCESSIVE HEAT EVENTS. RECORD HIGH TEMPERATURE
FOR TODAY IN PHOENIX IS 112 DEGREES...SET IN 1905...AND IS IN
JEOPARDY OF BEING TIED OR EVEN BROKEN THIS AFTERNOON.
CENTER OF THE ANTICYCLONE WILL MOVE INTO UT WEDNESDAY. THIS WILL
PRODUCE A WEAK NORTHEASTERLY FLOW WHICH WILL INCREASE DOWNSLOPING
AND ADIABATIC WARMING. TEMPERATURES ARE EXPECTED TO BE 1 TO 3
DEGREES WARMER THAN THOSE TUESDAY AND THE RECORD HIGH TEMPERATURE OF
113 DEGREES IN PHOENIX IS AGAIN IN JEOPARDY OF BEING ECLIPSED.
TEMPERATURES WILL BE EVEN WARMER ACROSS SW AZ AND SE CA AND THE
EXCESSIVE HEAT WATCH HAS BEEN UPGRADED TO A WARNING IN THESE AREAS.
LATEST SREF SHOWS DEEPER MOISTURE CURRENTLY ACROSS THE SOUTHERN
ROCKIES WHICH IS EXPECTED TO REACH EASTERN AZ WED EVENING. SCATTERED
THUNDERSTORMS WILL HAVE THE POTENTIAL TO PROPAGATE OUT OF GILA
COUNTY AND INTO THE LOWER ELEVATIONS WEDNESDAY NIGHT. AT THE VERY
LEAST...BLOWING DUST WILL BE A THREAT ACROSS THE PHOENIX METRO AREA
AND INTO PINAL COUNTY.
EASTERLY FLOW WILL STRENGTHEN THURSDAY AS THE HIGH BECOMES
POSITIONED NEAR THE FOUR CORNERS. DRIER AIR WILL SHIFT WESTWARD AND
THERE IS INCREASING UNCERTAINTY WITH REGARD TO THE EXCESSIVE HEAT.
IT IS CONCEIVABLE THAT THURSDAY WILL BE COOLER IF AN OUTFLOW
BOUNDARY MOVES THROUGH WEDNESDAY NIGHT. AT THIS POINT...THE WATCH
WILL BE EXTENDED ONLY FOR SW AZ AND SE CA.
THE ANOMALOUS HIGH WILL PERSIST INTO EARLY NEXT WEEK. GFS/ECMWF IN
GOOD AGREEMENT THAT DRIER AIR WILL EVENTUALLY BE ADVECTED WESTWARD.
ANOTHER STRETCH OF EXCESSIVE HEAT IS LIKELY ALONG WITH BELOW AVERAGE
RAIN CHANCES.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
FEW-SCT MID-HIGH LEVEL CIGS ARE EXPECTED TO PREVAIL AT THE PHOENIX
AREA TERMINALS THRU THE TAF PERIOD. GUSTY NORTHEASTERLY WINDS THAT
WERE SEEN AT THE TERMINALS A COUPLE OF HOURS AGO HAVE DIMINISHED.
TYPICAL EASTERLY DIURNAL WINDS ARE EXPECTED TO PREVAIL THRU THE REST
OF TONIGHT...ALTHOUGH THEY BE ENHANCED A BIT OVER THE NEXT FEW HOURS
BY OUTFLOWS FROM DISSIPATING THUNDERSTORMS OVER SOUTHEAST PINAL
COUNTY.
SOUTHEAST CALIFORNIA...SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
VFR CIRRUS CIGS AND MAINLY LIGHT WINDS TO PREVAIL AT BOTH KBLH AND
KIPL THROUGH THE PERIOD.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
STRONG UPPER LEVEL HIGH PRESSURE WILL REMAIN STATIONED OVER THE
INTERMOUNTAIN WEST THROUGH THE WEEKEND. AS A RESULT...ABOVE
NORMAL/VERY HOT TEMPERATURES AND DAILY DAYTIME RELATIVE HUMIDITY
VALUES IN THE TEENS ARE EXPECTED. SUFFICIENT MOISTURE AND
INSTABILITY OVER THE MOUNTAINS OF SOUTH-CENTRAL ARIZONA WILL PROVIDE
NEARLY A DAILY THREAT OF AFTERNOON/EVENING THUNDERSTORMS...AND
OCCASIONALLY A FEW STORMS COULD PROPAGATE INTO THE LOWER DESERT
ELEVATIONS. ANY WETTING RAINFALL EVENTS WILL BE ISOLATED AND
SPORADIC. OUTSIDE OF ANY STRONG GUSTY WINDS ASSOCIATED WITH
STORMS...LIGHT WINDS EXPECTED THROUGH THE PERIOD.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...EXCESSIVE HEAT WARNING UNTIL 8 PM MST WEDNESDAY
AZZ022-023-027-028.
EXCESSIVE HEAT WARNING FROM 10 AM TO 8 PM MST WEDNESDAY
AZZ020-021-025-026.
EXCESSIVE HEAT WATCH FROM WEDNESDAY EVENING THROUGH FRIDAY
EVENING AZZ020-021-025-026.
CA...EXCESSIVE HEAT WARNING FROM 10 AM TO 8 PM PDT WEDNESDAY
CAZ031>033.
EXCESSIVE HEAT WATCH FROM WEDNESDAY EVENING THROUGH FRIDAY
EVENING CAZ031>033.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
AVIATION...PERCHA
FIRE WEATHER...MO
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
350 PM MST TUE AUG 7 2012
.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL OVER THE DESERT SOUTHWEST THIS
WEEK...RESULTING IN WELL ABOVE NORMAL TEMPERATURES AND PERIODS OF
EXCESSIVE HEAT. THUNDERSTORM CHANCES WILL BE FOCUSED MAINLY OVER
HIGHER TERRAIN OF NORTHERN AND EASTERN ARIZONA TODAY...THOUGH THERE
WILL BE A CHANCE OF STORMS WEDNESDAY AND THURSDAY ACROSS
SOUTH-CENTRAL ARIZONA. THE WELL ABOVE NORMAL TEMPERATURES WILL
PERSIST THROUGH AT LEAST THE WEEKEND ALONG WITH BELOW NORMAL CHANCES
FOR RAIN AND THUNDERSTORMS.
&&
.DISCUSSION...
LATEST WV IMAGERY SHOWS A COMPACT VORT MAX MOVING STEADILY WESTWARD
ACROSS NORTHERN SONORA WHILE ISOLATED THUNDERSTORMS HAVE PERSISTED
EARLY THIS MORNING ACROSS PIMA COUNTY. MODELS HAVE HAD A DIFFICULT
TIME INITIALIZING THE TROUGH...THOUGH THE LATEST HRRR SUGGESTS
ISOLATED CONVECTION WILL REMAIN A THREAT THROUGH THE DAY FROM YUMA
INTO THE IMPERIAL VALLEY. A WEAK BOUNDARY IS EVIDENT ON IR SATELLITE
AND IT SEEMS REASONABLE THAT ISOLATED CELLS COULD DEVELOP ALONG AND
AHEAD OF THIS FEATURE. FURTHER EAST ACROSS SOUTH-CENTRAL
AZ...EXCESSIVE HEAT WILL BE THE MAIN STORY AS A STRONG ANTICYCLONE
IN NM DRIFTS WESTWARD AND INTO NORTHERN AZ BY THIS AFTERNOON.
INCREASING NVA AND WEAK SUBSIDENCE WILL GENERALLY PRECLUDE
CONVECTION ACROSS THE LOWER DESERTS. STEERING FLOW REMAINS WEAK AND
ISOLATED THUNDERSTORMS ARE AGAIN EXPECTED TO REMAIN CONFINED TO THE
HIGHER ELEVATIONS OF GILA COUNTY. TEMPERATURES WERE WEIGHTED HEAVILY
TOWARDS THE ECMWF...WHICH HAS PERFORMED WELL RECENTLY AND TENDS TO
DO A BETTER JOB WITH EXCESSIVE HEAT EVENTS. RECORD HIGH TEMPERATURE
FOR TODAY IN PHOENIX IS 112 DEGREES...SET IN 1905...AND IS IN
JEOPARDY OF BEING TIED OR EVEN BROKEN THIS AFTERNOON.
CENTER OF THE ANTICYCLONE WILL MOVE INTO UT WEDNESDAY. THIS WILL
PRODUCE A WEAK NORTHEASTERLY FLOW WHICH WILL INCREASE DOWNSLOPING
AND ADIABATIC WARMING. TEMPERATURES ARE EXPECTED TO BE 1 TO 3
DEGREES WARMER THAN THOSE TUESDAY AND THE RECORD HIGH TEMPERATURE OF
113 DEGREES IN PHOENIX IS AGAIN IN JEOPARDY OF BEING ECLIPSED.
TEMPERATURES WILL BE EVEN WARMER ACROSS SW AZ AND SE CA AND THE
EXCESSIVE HEAT WATCH HAS BEEN UPGRADED TO A WARNING IN THESE AREAS.
LATEST SREF SHOWS DEEPER MOISTURE CURRENTLY ACROSS THE SOUTHERN
ROCKIES WHICH IS EXPECTED TO REACH EASTERN AZ WED EVENING. SCATTERED
THUNDERSTORMS WILL HAVE THE POTENTIAL TO PROPAGATE OUT OF GILA
COUNTY AND INTO THE LOWER ELEVATIONS WEDNESDAY NIGHT. AT THE VERY
LEAST...BLOWING DUST WILL BE A THREAT ACROSS THE PHOENIX METRO AREA
AND INTO PINAL COUNTY.
EASTERLY FLOW WILL STRENGTHEN THURSDAY AS THE HIGH BECOMES
POSITIONED NEAR THE FOUR CORNERS. DRIER AIR WILL SHIFT WESTWARD AND
THERE IS INCREASING UNCERTAINTY WITH REGARD TO THE EXCESSIVE HEAT.
IT IS CONCEIVABLE THAT THURSDAY WILL BE COOLER IF AN OUTFLOW
BOUNDARY MOVES THROUGH WEDNESDAY NIGHT. AT THIS POINT...THE WATCH
WILL BE EXTENDED ONLY FOR SW AZ AND SE CA.
THE ANOMALOUS HIGH WILL PERSIST INTO EARLY NEXT WEEK. GFS/ECMWF IN
GOOD AGREEMENT THAT DRIER AIR WILL EVENTUALLY BE ADVECTED WESTWARD.
ANOTHER STRETCH OF EXCESSIVE HEAT IS LIKELY ALONG WITH BELOW AVERAGE
RAIN CHANCES.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
FEW-SCT MID-HIGH LEVEL CIGS ARE EXPECTED TO PREVAIL AT THE PHOENIX
AREA TERMINALS THRU THE TAF PERIOD. GUSTY NORTHEASTERLY WINDS THAT
WERE SEEN AT THE TERMINALS A COUPLE OF HOURS AGO HAVE DIMINISHED.
TYPICAL EASTERLY DIURNAL WINDS ARE EXPECTED TO PREVAIL THRU THE REST
OF TONIGHT...ALTHOUGH THEY BE ENHANCED A BIT OVER THE NEXT FEW HOURS
BY OUTFLOWS FROM DISSIPATING THUNDERSTORMS OVER SOUTHEAST PINAL
COUNTY.
SOUTHEAST CALIFORNIA...SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
VFR CIRRUS CIGS AND MAINLY LIGHT WINDS TO PREVAIL AT BOTH KBLH AND
KIPL THROUGH THE PERIOD.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
STRONG UPPER LEVEL HIGH PRESSURE WILL REMAIN STATIONED OVER THE
INTERMOUNTAIN WEST THROUGH THE WEEKEND. AS A RESULT...ABOVE
NORMAL/VERY HOT TEMPERATURES AND DAILY DAYTIME RELATIVE HUMIDITY
VALUES IN THE TEENS ARE EXPECTED. SUFFICIENT MOISTURE AND
INSTABILITY OVER THE MOUNTAINS OF SOUTH-CENTRAL ARIZONA WILL PROVIDE
NEARLY A DAILY THREAT OF AFTERNOON/EVENING THUNDERSTORMS...AND
OCCASIONALLY A FEW STORMS COULD PROPAGATE INTO THE LOWER DESERT
ELEVATIONS. ANY WETTING RAINFALL EVENTS WILL BE ISOLATED AND
SPORADIC. OUTSIDE OF ANY STRONG GUSTY WINDS ASSOCIATED WITH
STORMS...LIGHT WINDS EXPECTED THROUGH THE PERIOD.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...EXCESSIVE HEAT WARNING UNTIL 8 PM MST WEDNESDAY
AZZ022-023-027-028.
EXCESSIVE HEAT WARNING FROM 10 AM TO 8 PM MST WEDNESDAY
AZZ020-021-025-026.
EXCESSIVE HEAT WATCH FROM WEDNESDAY EVENING THROUGH FRIDAY
EVENING AZZ020-021-025-026.
CA...EXCESSIVE HEAT WARNING FROM 10 AM TO 8 PM PDT WEDNESDAY
CAZ031>033.
EXCESSIVE HEAT WATCH FROM WEDNESDAY EVENING THROUGH FRIDAY
EVENING CAZ031>033.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
AVIATION...PERCHA
FIRE WEATHER...MO
AREA FORECAST DISCUSSION...CORRECTED
NWS BALTIMORE MD/WASHINGTON DC
1029 AM EDT TUE AUG 7 2012
.SYNOPSIS...
WEAK HIGH PRESSURE WILL MOVE OFFSHORE TODAY...PERMITTING
SOUTHWEST FLOW TO BECOME ESTABLISHED THROUGH THE END OF THE WEEK.
A COLD FRONT WILL ARRIVE BY LATE FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
REMNANT FRONTAL BOUNDARY REMAINS STATIONARY OVER THE NRN PIEDMONT
AND SRN MD THIS MRNG. LIGHT NLY FLOW AND DEWPOINTS IN THE 60S RESIDE
NORTH OF THE BOUNDARY WITH LIGHT SLY FLOW AND DEWPOINTS IN THE
LOWER 70S TO THE SOUTH. BLENDED SAT AND RAP ANALYSIS SHOWED A
TIGHT NW TO SE PWAT GRADIENT...RANGING FROM THREE-QUARTER INCH
OVER CBE TO ALMOST TWO INCHES OVER NHK. 12Z IAD RAOB SHOWED A VERY
DRY AIRMASS ABOVE H7 AND PWAT OF 1.2 INCH.
WEAK CONVERGENCE ALONG THE BOUNDARY AND THE APPROACH OF A SUBTLE
SHORTWAVE TROUGH HAS PROVIDED ENOUGH FORCING TO TRIGGER SHOWERS AND
STORMS IN LOWER SRN MD THIS MRNG. WITH WEAK FLOW ALOFT AND A STALLED
BOUNDARY...STORMS HAD LITTLE MOVEMENT OVER ST MARYS...RESULTING IN
RADAR ESTIMATED RAINFALL OF 3 INCHES IN JUST OVER AN HOUR. THE
ENVIRONMENT WILL NOT CHANGE MUCH TDA AND WILL BE FAVORABLE FOR A
LOCALIZED THREAT OF FLASH FLOODING IN FAR SRN ZONES OF THE CWA.
SUBSIDENCE BEHIND THE UPPER SHORTWAVE TROUGH SHOULD LIMIT COVERAGE
OF STORMS THIS AFTN IN SRN MD AND EVERYWHERE FOR THAT MATTER. SOUTH
OF THE BOUNDARY...A FEW SHOWERS AND STORMS STILL EXPECTED TO DEVELOP
IN THE MOIST/UNSTABLE AIRMASS OVER CENTRAL VA AND SRN MD. IF SOME
PERSISTENT BREAKS IN MRNG CLOUD COVER DEVELOP THIS AFTN...THEN ONE
OR TWO STORMS IN CENTRAL VA AND SRN MD COULD BECOME PULSE SEVERE
GIVEN THE FAVORABLE ENVIRONMENT FOR A WET MICROBURST.
MODEL MAX T HAS BEEN RUNNING SVRL DEGREES TOO COOL FOR SVRL DAYS
NOW. DONT FORSEE AMS TDA TO BE ANY COOLER THAN YDA. IF ANYTHING H8
TEMPS WL RISE BY ANTHR DEG OR SO. THEREFORE...HV BASED MAXT FCST
ON PERSISTENCE MORE THAN MOS...AND WL BE COMING IN A FEW DEG HIER
THAN THE WARMEST OFFERING. MIN-T SEEMS MORE REASONABLE...IN STEP
W/ DEWPTS...AND HV BLENDED W/ MET.
&&
.SHORT TERM /WEDNESDAY/...
AFTER BEING HELD DOWN ACROSS THE VA/NC BORDER FOR A COUPLE OF
DAYS...THE STATIONARY BOUNDARY WILL BEGIN TO LIFT TOWARD THE NORTH
ON WED. THE BOUNDARY THOUGH WILL WASH-OUT AND WILL BASICALLY MORPH
INTO A CONVERGENCE ZONE FOR PRECIP ALONG THE SRN ATLC COAST. AS THIS
CORRIDOR ORIENTS ITSELF FROM SW-NE...IT WILL ALSO ALLOW FOR SOME
WEAKER AREAS OF LIFT TO EXIST ALONG THE I-95 CORRIDOR - ALONG W/ A
TIGHT MOISTURE GRADIENT. DEWPOINTS ACROSS THE MTNS WILL DROP DOWN
INTO THE 50S AND EFFECTIVELY END PRECIP CHANCES FOR THE DAY...WHILE
L70S EXIST E OF THE BLUE RIDGE. ISOLATED SHOWERS/TSTMS WILL BE
POSSIBLE ACROSS THESE AREAS...ESPECIALLY CLOSER TO THE BAY. THIS
WILL ALSO RESULT IN BALMY CONDITIONS FOR THE METRO AREAS...BUT MORE
COMFORTABLE ACROSS THE VLYS/MTNS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
CHANGES WILL COME GRADUALLY OVER THE SECOND HALF OF THE WEEK.
SEVERAL UPPER VORT LOBES WILL SWING AROUND A POSITIVELY TILTED UPPER
TROF SLIDING DOWN FROM THE GREAT LAKES REGION. AS THE FIRST ONE
APPROACHES ON THU AFTN...SHOWERS AND TSTMS WILL BE ON THE INCREASE
FROM WEST-TO-EAST BUT MAINLY FOR LATER IN THE DAY AND OVERNIGHT.
EMBEDDED AREAS OF CONVECTION WILL BE POSSIBLE W/ THE OVERNIGHT
ACTIVITY...BUT THERE WILL BE MUCH LOWER INSTABILITY AT THAT POINT.
AFTER A BRIEF LULL EARLY FRI...THE NEXT UPPER VORT WILL THEN PULL
THE TROF AXIS DOWN ACROSS THE AREA. THIS WILL BRING A GOOD CHANCE
FOR MORE WIDESPREAD SHOWERS AND SOME EMBEDDED SCATTERED STORMS. THE
TROUGH AXIS WILL THEN TURN INTO A CUT-OFF UPPER LOW THAT MOST LONG
TERM GUIDANCE AGREES WILL TAKE OFF TOWARD NEW ENGLAND BUT NOT BEFORE
DEVELOPING SOME SHOWERS ACROSS THE ERN HALF OF THE CWA ON SAT.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
CHO WAS THE ONLY SIDE BELOW VFR AT 12Z TAF ISSUANCE...BUT HAS SINCE
IMPROVED TO VFR. AREA CAUGHT BTWN DRY AIR ATTEMPTING TO SNEAK SWD
FM PA WHILE HUMID AIR RIDES NEWD TDA. IT/LL LEAD TO LOTSA
CLDCVR...BUT SUSPECT MOST OF IT WL BE MID DECK...IE VFR FLGT CONDS
WL GNLY PREVAIL.
VERY SMALL CHANCE /AROUND 20 PERCENT/ FOR AN ISO SHOWER OR STORM
TO BRIEFLY IMPACT CHO THIS AFTN OR ERY EVE. THUS LIKELIHOOD IS TOO
LOW TO INCLUDE IN TAFS.
SAME AIRMASS TNGT...WHICH COULD LEAD TO ANOTHER ROUND OF
FOG AT MRB/CHO. BASED ON WHAT HAPPENED THIS MRNG...LOCAL
RESTRICTION MAY DROP INTO IFR RANGE ERY WED MRNG.
MAINLY DRY ON WED...THOUGH A FEW SHOWERS/TSTMS MAY DEVELOP ALONG
THE I-95 CORRIDOR AFTER SOME DAYTIME HEATING LATER IN THE AFTN-EVE
HRS. A MORE POTENT LOW PRESSURE SYSTEM WILL THEN APPROACH THE AREA
ON THU...BRINGING ANOTHER CHANCE FOR PRECIP THU AFTN THROUGH SAT
MRNG - FRI BEING THE BEST CHANCE FOR WIDESPREAD SHOWER/TSTM
ACTIVITY. WINDS WILL BE MAINLY LIGHT EACH DAY...W/ A STEADY SLY
BREEZE EACH AFTN THIS WEEK.
&&
.MARINE...
COMPLEX FLOW ACRS THE REGION. GNLY WSWLY WNDS PREVAIL...THO NRN BAY
STILL REFLECTS WK NNELY FLOW FM THE COOLER/DRIER AIR PARKED ACRS
PA.
OVER THE COURSE OF THE DAY...THE SLY FLOW WL WIN OUT...AND MAY
RESULT IN A LTL CHANNELING BY DAYS END. NO FLAGS XPCTD. MAY ALSO HV
A CPL AFTN-EVE TSTMS OVER THE LOWER TIDAL POTOMAC AND MD CHSPK
BAY. CANNOT RULE OUT THE ISSUANCE OF ONE OR TWO SMWS FOR GUSTY
TSTM WINDS.
LIGHT WINDS HEADING INTO WED...THOUGH A FEW BRIEF PERIODS OF SLY
CHANNELING W/ DEVELOP OVER THE LOWER BAY PERIODICALLY THRU THE END
OF THE CURRENT WEEK. AN UPPER LOW WILL THEN GLIDE JUST TO OUR NORTH
THU/FRI...BRINGING MORE PRECIP CHANCES TO AREA TO CLOSE OUT THE WORK
WEEK. THE UPPER LOW WILL THEN RACE OFF TOWARD NEW ENGLAND THIS
WEEKEND.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
UPDATE...KLEIN
PREV DISC...HTS/GMS
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
959 AM EDT TUE AUG 7 2012
.SYNOPSIS...
WEAK HIGH PRESSURE WILL MOVE OFFSHORE TODAY...PERMITTING
SOUTHWEST FLOW TO BECOME ESTABLISHED THROUGH THE END OF THE WEEK.
A COLD FRONT WILL ARRIVE BY LATE FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
REMNANT FRONTAL BOUNDARY REMAINS STATIONARY OVER THE NRN PIEDMONT
AND SRN MD THIS MRNG. LIGHT NLY FLOW AND DEWPOINTS IN THE 60S RESIDE
NORTH OF THE BOUNDARY WITH LIGHT SLY FLOW AND DEWPOINTS IN THE
LOWER 70S TO THE SOUTH. BLENDED SAT AND RAP ANALYSIS SHOWED A
TIGHT NW TO SE PWAT GRADIENT...RANGING FROM THREE-QUARTER INCH
OVER CBE TO ALMOST TWO INCHES OVER NHK. 12Z IAD RAOB SHOWED A VERY
DRY AIRMASS ABOVE H7 AND PWAT OF 1.2 INCH.
WEAK CONVERGENCE ALONG THE BOUNDARY AND THE APPROACH OF A SUBTLE
SHORTWAVE TROUGH HAS PROVIDED ENOUGH FORCING TO TRIGGER SHOWERS AND
STORMS IN LOWER SRN MD THIS MRNG. WITH WEAK FLOW ALOFT AND A STALLED
BOUNDARY...STORMS HAD LITTLE MOVEMENT OVER ST MARYS...RESULTING IN
RADAR ESTIMATED RAINFALL OF 3 INCHES IN JUST OVER AN HOUR. THE
ENVIRONMENT WILL NOT CHANGE MUCH TDA AND WILL BE FAVORABLE FOR A
LOCALIZED THREAT OF FLASH FLOODING IN FAR SRN ZONES OF THE CWA.
SUBSIDENCE BEHIND THE UPPER SHORTWAVE TROUGH SHOULD LIMIT COVERAGE
OF STORMS THIS AFTN IN SRN MD AND EVERYWHERE FOR THAT MATTER. SOUTH
OF THE BOUNDARY...A FEW SHOWERS AND STORMS STILL EXPECTED TO DEVELOP
IN THE MOIST/UNSTABLE AIRMASS OVER CENTRAL VA AND SRN MD. IF SOME
PERSISTENT BREAKS IN MRNG CLOUD COVER DEVELOP THIS AFTN...THEN ONE
OR TWO STORMS IN CENTRAL VA AND SRN MD COULD BECOME PULSE SEVERE
GIVEN THE FAVORABLE ENVIRONMENT FOR A WET MICROBURST.
MOS MAXT HAS BEEN RUNNING SVRL DEGF TOO WARM FOR SVRL DAYS NOW. DONT
FORSEE AMS TDA TO BE ANY COOLER THAN YDA. IF ANYTHING H8 TEMPS WL
RISE BY ANTHR DEG OR SO. THEREFORE...HV BASED MAXT FCST ON
PERSISTENCE MORE THAN MOS...AND WL BE COMING IN A FEW DEG HIER THAN
THE WARMEST OFFERING. MIN-T SEEMS MORE REASONABLE...IN STEP W/
DEWPTS...AND HV BLENDED W/ MET.
&&
.SHORT TERM /WEDNESDAY/...
AFTER BEING HELD DOWN ACROSS THE VA/NC BORDER FOR A COUPLE OF
DAYS...THE STATIONARY BOUNDARY WILL BEGIN TO LIFT TOWARD THE NORTH
ON WED. THE BOUNDARY THOUGH WILL WASH-OUT AND WILL BASICALLY MORPH
INTO A CONVERGENCE ZONE FOR PRECIP ALONG THE SRN ATLC COAST. AS THIS
CORRIDOR ORIENTS ITSELF FROM SW-NE...IT WILL ALSO ALLOW FOR SOME
WEAKER AREAS OF LIFT TO EXIST ALONG THE I-95 CORRIDOR - ALONG W/ A
TIGHT MOISTURE GRADIENT. DEWPOINTS ACROSS THE MTNS WILL DROP DOWN
INTO THE 50S AND EFFECTIVELY END PRECIP CHANCES FOR THE DAY...WHILE
L70S EXIST E OF THE BLUE RIDGE. ISOLATED SHOWERS/TSTMS WILL BE
POSSIBLE ACROSS THESE AREAS...ESPECIALLY CLOSER TO THE BAY. THIS
WILL ALSO RESULT IN BALMY CONDITIONS FOR THE METRO AREAS...BUT MORE
COMFORTABLE ACROSS THE VLYS/MTNS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
CHANGES WILL COME GRADUALLY OVER THE SECOND HALF OF THE WEEK.
SEVERAL UPPER VORT LOBES WILL SWING AROUND A POSITIVELY TILTED UPPER
TROF SLIDING DOWN FROM THE GREAT LAKES REGION. AS THE FIRST ONE
APPROACHES ON THU AFTN...SHOWERS AND TSTMS WILL BE ON THE INCREASE
FROM WEST-TO-EAST BUT MAINLY FOR LATER IN THE DAY AND OVERNIGHT.
EMBEDDED AREAS OF CONVECTION WILL BE POSSIBLE W/ THE OVERNIGHT
ACTIVITY...BUT THERE WILL BE MUCH LOWER INSTABILITY AT THAT POINT.
AFTER A BRIEF LULL EARLY FRI...THE NEXT UPPER VORT WILL THEN PULL
THE TROF AXIS DOWN ACROSS THE AREA. THIS WILL BRING A GOOD CHANCE
FOR MORE WIDESPREAD SHOWERS AND SOME EMBEDDED SCATTERED STORMS. THE
TROUGH AXIS WILL THEN TURN INTO A CUT-OFF UPPER LOW THAT MOST LONG
TERM GUIDANCE AGREES WILL TAKE OFF TOWARD NEW ENGLAND BUT NOT BEFORE
DEVELOPING SOME SHOWERS ACROSS THE ERN HALF OF THE CWA ON SAT.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
CHO WAS THE ONLY SIDE BELOW VFR AT 12Z TAF ISSUANCE...BUT HAS SINCE
IMPROVED TO VFR. AREA CAUGHT BTWN DRY AIR ATTEMPTING TO SNEAK SWD
FM PA WHILE HUMID AIR RIDES NEWD TDA. IT/LL LEAD TO LOTSA
CLDCVR...BUT SUSPECT MOST OF IT WL BE MID DECK...IE VFR FLGT CONDS
WL GNLY PREVAIL.
VERY SMALL CHANCE /AROUND 20 PERCENT/ FOR AN ISO SHOWER OR STORM
TO BRIEFLY IMPACT CHO THIS AFTN OR ERY EVE. THUS LIKELIHOOD IS TOO
LOW TO INCLUDE IN TAFS.
SAME AIRMASS TNGT...WHICH COULD LEAD TO ANOTHER ROUND OF
FOG AT MRB/CHO. BASED ON WHAT HAPPENED THIS MRNG...LOCAL
RESTRICTION MAY DROP INTO IFR RANGE ERY WED MRNG.
MAINLY DRY ON WED...THOUGH A FEW SHOWERS/TSTMS MAY DEVELOP ALONG
THE I-95 CORRIDOR AFTER SOME DAYTIME HEATING LATER IN THE AFTN-EVE
HRS. A MORE POTENT LOW PRESSURE SYSTEM WILL THEN APPROACH THE AREA
ON THU...BRINGING ANOTHER CHANCE FOR PRECIP THU AFTN THROUGH SAT
MRNG - FRI BEING THE BEST CHANCE FOR WIDESPREAD SHOWER/TSTM
ACTIVITY. WINDS WILL BE MAINLY LIGHT EACH DAY...W/ A STEADY SLY
BREEZE EACH AFTN THIS WEEK.
&&
.MARINE...
COMPLEX FLOW ACRS THE REGION. GNLY WSWLY WNDS PREVAIL...THO NRN BAY
STILL REFLECTS WK NNELY FLOW FM THE COOLER/DRIER AIR PARKED ACRS
PA.
OVER THE COURSE OF THE DAY...THE SLY FLOW WL WIN OUT...AND MAY
RESULT IN A LTL CHANNELING BY DAYS END. NO FLAGS XPCTD. MAY ALSO HV
A CPL AFTN-EVE TSTMS OVER THE LOWER TIDAL POTOMAC AND MD CHSPK
BAY. CANNOT RULE OUT THE ISSUANCE OF ONE OR TWO SMWS FOR GUSTY
TSTM WINDS.
LIGHT WINDS HEADING INTO WED...THOUGH A FEW BRIEF PERIODS OF SLY
CHANNELING W/ DEVELOP OVER THE LOWER BAY PERIODICALLY THRU THE END
OF THE CURRENT WEEK. AN UPPER LOW WILL THEN GLIDE JUST TO OUR NORTH
THU/FRI...BRINGING MORE PRECIP CHANCES TO AREA TO CLOSE OUT THE WORK
WEEK. THE UPPER LOW WILL THEN RACE OFF TOWARD NEW ENGLAND THIS
WEEKEND.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
UPDATE...KLEIN
PREV DISC...HTS/GMS
AREA FORECAST DISCUSSION
NWS JACKSON MS
1010 AM CDT TUE AUG 7 2012
.UPDATE...CLEAR TO PARTLY CLOUDY SKIES PREVAIL ACROSS MOST OF THE
ARKLAMISS THIS MORNING...BUT THERE ARE A FEW SHOWERS OVER CATAHOULA
AND CONCORDIA PARISH. THESE SHOWERS WILL CONTINUE TO DIMINISH
THROUGH THE MORNING HOURS. DRIER AIR BUILDING IN FROM A HIGH
CENTERED TO THE NORTHWEST WILL RESULT IN MAINLY JUST ISOLATED
THUNDERSTORM COVERAGE THIS AFTERNOON WITH THE BEST COVERAGE MAINLY
ALONG AND SOUTH OF I-20. OUR LOCAL WRF MODEL AND THE HRRR MODEL ALSO
SUGGEST THIS. MADE SOME SLIGHT CHANGES TO THE POP/WEATHER THIS
AFTERNOON...BUT OTHER THAN THAT THE CURRENT FORECAST LOOKS ON TRACK
AND NO UPDATES ARE NEEDED AT THIS TIME./15/
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT...WITH MANY LOCATIONS
SEEING DECENT RAINFALL YESTERDAY...WE HAVE HAD TO CONTEND WITH FOG
THIS MORNING. LOCAL OBSERVATIONS SHOWING VISIBILITIES REDUCED IN
SOME PLACES TO 1/2-1/4 MILES...ESPECIALLY ALONG AND EAST OF I-55.
WILL CONTINUE TO MENTION PATCHY FOG THROUGH ABOUT 13-14Z BUT INCLUDE
MENTION OF DENSE FOG IN THE EAST AND SOUTH. VISIBILITIES ARE GOING
UP AND DOWN BUT WILL CONTINUE TO MONITOR IF AN ADVISORY IS NEEDED
THIS MORNING.
DRIER AIR HAS MOVED IN ALOFT ACROSS THE REGION AND THIS IS EVIDENT
IN A REDUCTION IN THE OVERALL PW VALUE PER THE 00Z KJAN SOUNDING.
DEWPOINTS THIS MORNING ARE RUNNING ABOUT 2-4 DEGREES LOWER THAN 24
HOURS AGO. IN ADDITION...THE UPPER TROUGH IS FORECAST TO BE TO OUR
EAST WITH NORTHWEST FLOW ALOFT OVER THE REGION. ALL OF THIS WILL
COMBINE FOR MORE OF A LACK OF STORM ACTIVITY TODAY. THE AREA WHERE
THE BETTER CHANCE WILL BE IS SOUTH OF I-20 WHERE ISOLATED COVERAGE
IS EXPECTED AT MOST AND THIS MAY EVEN STRUGGLE WITH THE DRIER AIR IN
PLACE. HIGHS TODAY ONCE AGAIN SHOULD REACH INTO THE MID
90S...ESPECIALLY IN THE DELTA WHERE RAINFALL REMAINS SCARCE AND
DRIER AIR SHOULD HELP CONDITIONS WARM UP. OVERNIGHT LOWS WILL BE IN
THE LOWER 70S AND EVEN SOME UPPER 60S.
FOR WEDNESDAY...THE UPPER PATTERN WILL REMAIN SIMILAR WITH THE
TROUGH TO THE EAST AND THE MAIN UPPER RIDGE TO THE WEST. WE MAY SEE
A LITTLE MORE IN THE WAY OF DAYTIME SHOWERS AND
THUNDERSTORMS...ESPECIALLY ACROSS THE SOUTH AS TEMPERATURES WARM
INTO THE MID 90S ONCE AGAIN. THE DRIEST AIRMASS WILL ONCE AGAIN BE
LOCATED IN THE DELTA...LIMITING ANY RAIN CHANCES THERE WHERE THE
MOIST AIR WILL BE ACROSS THE FAR SOUTHERN PORTIONS OF THE PINE BELT.
ANY DAYTIME ACTIVITY WILL DIMINISH WITH SUNSET...LEAVING RELATIVELY
COOL NIGHT AS COMPARED TO RECENT WEEKS. /28/
.LONG TERM...THURSDAY THROUGH MONDAY...NOT MUCH CHANGE FROM THE PREV
LONG TERM AS MED RANGE GUID CONTINUE TO SUPPORT A SIMILAR PATTERN
FOR LATE WEEK AND THE WEEKEND. ACTUALLY...MODELS ARE IN BETTER
AGREEMENT THAN LAST NIGHT...THUS THE EVOLUTION OF PRIMARY ELEMENTS
CONTAIN HIGHER CONFIDENCE. ONE OF THE MAIN FEATURES OF INTEREST IS A
LATE SUMMER COOL FRONT THAT NOW LOOKS TO PUSH WELL INTO THE CWA IF
NOT THROUGH THE CWA BY EARLY SATURDAY.
NW FLOW PATTERN WILL BE IN PLACE THROUGH THE WEEKEND WITH A FEW
DISTINCT S/WV`S DRIVING THE MAIN WEATHER FEATURES. FIRST OFF ON
THU-FRI THE CWA WILL BE LOCATED SOUTH OF THE SFC FRONT AND WITHIN
THE LOW LEVEL THERMAL AXIS. THIS WILL SUPPORT EASILY MID 90 DEGREE
TEMPS THU AFTERNOON. I WOULD LIKE TO WARM TEMPS MORE...BUT THERE ARE
A FEW THINGS THAT THE MODELS ARE SHOWING THAT IS HOLDING ME BACK
FROM BEING MORE AGGRESSIVE. FOR FRI...TEMPS WERE WARMED SOME 2-4
DEGREES TO KEEP IN LINE WITH WARMER READINGS JUST AHEAD OF THE SFC
FRONT. AS FOR PRECIP/WX...THE FIRST S/WV LOOKS TO IMPACT THE CWA
LATE THU AFTERNOON AND MOST LIKELY THU NGT. THERE LOOKS TO BE SOME
LINGERING MID LEVEL DRY AIR OVER THE NW HALF OF THE CWA ON THU AND
IT WILL LIKELY TAKE MOST OF THE DAY FOR THE APPROACHING S/WV TO
PROVIDE SUFFICIENT LIFT TO ERODE THAT LAYER...THUS BETTER POPS ARE
FOCUSED THU EVE/NGT WHICH IS INLINE WITH LATEST GFS. QUICKLY ON THE
HEALS OF THE FIRST S/WV WILL BE A MORE POTENT WAVE THAT IS MORE
PHASED WITH THE LONG WAVE TROUGH AXIS THAT WILL STRETCH FROM THE
GREAT LAKES DOWN THROUGH THE LOWER MS VALLEY. THIS WILL PROMOTE
ADDITIONAL STORM DEVELOPMENT FRI...ESPECIALLY ACROSS THE SOUTH HALF
WHERE DEEPEST MOISTURE LOOKS TO EXIST.
THE ABOVE MENTIONED LONG WAVE TROUGH WILL BE THE DRIVING FORCE THAT
LOOKS TO PUSH A COOL FRONT WELL INTO THE CWA FOR LATE FRI NGT/SAT.
DON`T EXPECT "COOL" AIR...BUT THE CHANGE IN AIRMASS SHOULD KNOCK THE
EDGE OFF THE HEAT AS HIGH WILL BE MORE FROM THE UPPER 80S TO LOWER
90S INSTEAD OF THE MID 90S. ADDITIONALLY...DRIER AIR WILL MOVE IN
AND SFC DEWPTS LOOK TO FALL WELL INTO THE 60S. THIS WILL ALSO
SUPPORT SLIGHTLY COOLER NIGHTS WITH LOWS RANGING FROM 65-70 FROM
SAT-MON MORNINGS. OVERALL...THIS SHOULD BE SOME 3-5 DEGREES BELOW
AVG ALONG WITH LESS HUMIDITY. QUITE NICE FOR EARLY AUG. /CME
&&
.AVIATION...PATCHY SUB-VFR CONDITIONS AROUND EARLY THIS MORNING DUE
TO FOG HAVE LIFTED...ALTHOUGH SOME CLOUDS AND A FEW SHOWERS ARE
OCCURRING ACROSS PORTIONS OF NE LA BRUSHING THE SOUTHWEST EDGE OF
THE FORECAST AREA. EXPECTING SCATTERED CLOUDS TO DEVELOP THROUGHOUT
THE DAY...BUT NEARLY ALL CEILINGS SHOULD REMAIN ABOVE 3 KFT.
THUNDERSTORM COVERAGE SHOULD BE MUCH LESS THAN YESTERDAY...ALTHOUGH
THERE WILL STILL BE ISOLATED SPOTS OF ACTIVITY AROUND THIS AFTERNOON
ALONG AND SOUTH OF INTERSTATE TWENTY. WINDS WILL GENERALLY TEND TO
BE FROM THE NORTH FROM MIDDAY THROUGH EARLY EVENING AT 5 TO 10 MPH.
FOR TONIGHT THE POTENTIAL FOR PATCHY FOG SHOULD BE LOWER THAN WHAT
WAS THE CASE THIS MORNING. /BB/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 94 70 96 71 / 14 13 12 17
MERIDIAN 95 70 96 71 / 13 13 12 19
VICKSBURG 95 68 95 69 / 13 13 12 13
HATTIESBURG 96 73 97 74 / 17 19 40 24
NATCHEZ 93 71 93 73 / 15 14 29 17
GREENVILLE 95 69 96 71 / 8 6 9 12
GREENWOOD 95 69 95 70 / 10 6 11 11
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
28/CME
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1015 AM EDT TUE AUG 7 2012
.SYNOPSIS...
AN UPPER LEVEL TROUGH WILL DRIFT EAST ACROSS THE CAROLINAS AND
SOUTHERN VIRGINIA TODAY AND TONIGHT...AND LIE ALONG THE COASTAL
PLAIN ON WEDNESDAY. ANOTHER UPPER LEVEL TROUGH WILL AFFECT OUR
REGION FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM TUESDAY...
AREAS OF LIGHT TO MODERATE RAIN STRETCH FROM THE SOUTHERN PIEDMONT
TO THE NORTHERN COASTAL PLAIN THIS MORNING...ALONG A SHEARED OUT
VORTICITY AXIS NOTED IN WATER VAPOR AND RAP 500MB ANALYSIS. WHILE
ALL OF THE CWA OVERCAST...THE LOW STRATUS IS THICKEST OVER THE FROM
THE TRIANGLE WESTWARD TO THE TRIAD....AND VISIBLE SATELLITE IMAGERY
SHOWS A VEIL OF MID CLOUDS STREAMING ACROSS THE WESTERN HALF OF THE
STATE. THUS...EVEN AS THE STRATUS SLOWLY LIFTS THIS MORNING...SOME
AREAS MAY STRUGGLE TO GET OUT OF THE 70S...ESPECIALLY IN THOSE AREAS
WHERE RAIN FALLS THROUGH MIDDAY. SOME BREAKS IN CLOUD COVER ARE
BEGINNING TO SHOW OVER THE SOUTHERN COASTAL PLAIN...AND TEMPS COULD
REACH THE MID 80S FROM FAYETTEVILLE TO THE SOUTHEAST. WHILE
CONFIDENCE IN THE TEMP FORECAST IS LOW... HAVE ATTEMPTED TO ADJUST
TEMPS DOWNWARD OVER THE WESTERN PIEDMONT USING MET MOS AND NAM/GFS
RAW 2M TEMP FIELDS BASED...WHICH YIELDS VALUES ROUGHLY IN THE 79-85
RANGE.
REGARDING POPS...A WEAK UPPER LEVEL LOW AND ASSOCIATED VORT MAX OVER
AL/GA THIS MORNING WILL BE DRAWN NORTHWARD TODAY AHEAD OF AN UPPER
LEVEL TROUGH APPROACHING FROM THE MIDWEST. MEANWHILE.. A WEAK UPPER
JET OVER THE MID ATLANTIC STATES IS FORECAST TO BUILD BACK TO THE
SOUTHWEST ACROSS VA...WHICH SHOULD PROVIDE SOME RIGHT ENTRANCE
REGION LIFT AND ALSO HELP PRECIP EXPAND BACK TO THE NORTH OF THE
CURRENT PRECIP AXIS. MOST CAMS SUGGEST PRECIP WILL SHIFT NORTH
TOWARD ACROSS THE PIEDMONT THIS MORNING...THEN SHIFT EASTWARD TOWARD
THE COASTAL PLAIN LATER THIS AFTERNOON AND EVENING WITH THE SHEAR
AXIS. MOST OF THE WESTERN PIEDMONT SHOULD REMAIN RELATIVELY STABLE
AS COMPARED TO THE EASTERN PIEDMONT AND COASTAL PLAIN...WHERE
MODIFICATION OF THE 12Z KMHX RAOB SUGGEST 1000-1500 J/KG OF MLCAPE
IS POSSIBLE IF TEMPS CAN REACH THE MID 80S. DEEP LAYER SHEAR
FORECASTS CONTINUE TO BE BELOW 20KT...SO SEVERE POTENTIAL REMAINS
LOW AND WILL BE CONFINED TO STRONGER PULSE STORMS. HAVE MADE SOME
ADJUSTMENTS TO THE TIMING OF POPS THIS MORNING...BUT OVERALL THE
SHOWERS WILL BE NUMEROUS THIS AFTERNOON WITH SCATTERED STORMS AND
HEAVY RAIN MAINLY EAST.
FLASH FLOOD GUIDANCE HAS RECOVERED TO NORMAL VALUES FOR MOST AREAS
THIS MORNING. THE EXCEPTIONS APPEARS TO BE MAINLY RANDOLPH AND
STANLEY COUNTIES WHERE THE HEAVIEST RAIN FELL MONDAY. ONE TO TWO
INCHES IN AN HOUR OR TWO COULD CAUSE SOME FLOODING ISSUES IN THOSE
AREAS IF HEAVIER SHOWERS MATERIALIZE LATER TODAY. -SMITH
TONIGHT...BEST FOCUS FOR SHOWERS WILL BE ACROSS THE COASTAL PLAIN
THE FIRST HALF OF THE EVENING AS SHEAR AXIS DRIFTS EAST THOUGH
SHOULD SEE COVERAGE DECREASE BY MIDNIGHT AS AIR MASS STABILIZES AND
BEST LOW LEVEL MOISTURE TRANSPORT SHIFTS MORE TO THE IMMEDIATE COAST.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 AM TUESDAY...
WEDNESDAY AND WEDNESDAY NIGHT...WITH THE SHEAR AXIS CLOSER TO THE
COAST...EXPECT A RETURN TO MORE TYPICAL SUMMERTIME PATTERN OVER THE
PIEDMONT WITH RANDOM...DIURNALLY DRIVEN CONVECTION EXPECTED. SURFACE
PROJECTIONS SUGGEST A DEWPOINT GRADIENT BETWEEN THE TRIAD AND THE
TRIANGLE/FAY AREAS...SO EXPECT CONVECTION TO INITIATE ALONG THIS
FEATURE BY EARLY-MID AFTERNOON WITH CONVECTION DRIFTING EAST-SE.
THIS SUGGEST MORE COVERAGE IN THE SE VERSUS NW. PLAN TO HAVE POPS 30
PERCENT NW TO 50 PERCENT SE. PERIODS OF SUN PRIOR TO CONVECTION
INITIATION SHOULD LEAD TO AFTERNOON CLOSE TO NORMAL (UPPER 80S TO
AROUND 90). ANY CONVECTION WED EVENING SHOULD DIMINISH WITH LOSS OF
HEATING. PARTIAL CLEARING MAY ALLOW FOR THE DEVELOPMENT OF AREAS OF
FOG BY DAYBREAK THU. MIN TEMPS UPPER 60S TO LOWER 70S.-WSS
THURSDAY AND THURSDAY NIGHT:
BRIEF WESTERLY MID LEVEL FLOW IS EXPECTED TO AGAIN BACK TO
SOUTHWESTERLY ACROSS OUR AREA ON THURSDAY AS THE EAST COAST TROUGH
BEGINS TO DEEPEN AGAIN AS A STRONG S/W ALOFT DROPS
SOUTH/SOUTHEASTWARD OUT OF CANADA INTO THE UPPER MIDWEST AND GREAT
LAKES REGION. AT THE SURFACE MODELS INDICATE A SHARPENING
PIEDMONT/LEE SIDE TROUGH ACROSS THE AREA. BOTH NAM AND GFS BUFR
SOUNDINGS INDICATE A GOOD BIT OF DRY AIR IN THE MID LEVELS ALONG
WITH A WEAK CAP. HOWEVER... WITH SURFACE DEWPOINTS EXPECTED TO BE IN
THE UPPER 60S TO LOWER 70S (YIELDING MLCAPE IN THE 1500-2000 J/KG
RANGE FOR THE AFTERNOON) ALONG WITH THE SHARPENING SURFACE TROUGH
EXPECT WE WILL SEE SOME ISOLATED TO SCATTERED SHOWERS AND STORMS.
THUS... WILL CONTINUE A LOW END CHANCE FOR SHOWERS AND STORMS
THURSDAY AFTERNOON AND EVENING. WITH DEEP LAYER SHEAR AGAIN EXPECTED
TO REMAIN FAIRLY WEAK ON THE ORDER OF 15 TO 20 KTS DO NOT EXPECT ANY
ORGANIZED SEVERE WEATHER OUTBREAK. HOWEVER... A FEW STORMS MAY
BECOME STRONG TO SEVERE WITH THE MAIN THREAT OF DAMAGING DOWNBURST
WINDS AND MARGINALLY SEVERE HAIL. WITH LOW LEVEL THICKNESS VALUES
EXPECTED TO CLIMB TO AROUND 1420 METERS AND PARTLY SUNNY SKIES...
EXPECT WE WILL SE AFTERNOON HIGH TEMPS TOP OUT AROUND 90/LOWER 90S.
EXPECT CHANCES FOR SHOWERS AND STORMS TO DECREASE WITH THE LOSS OF
DAYTIME HEATING. OVERNIGHT LOWS ARE EXPECTED TO GENERALLY BE IN THE
LOWER 70S AGAIN... WITH PERHAPS A FEW OF THE URBAN AREAS REMAINING
IN THE MID 70S. -BSD
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 300 AM TUESDAY...
MEDIUM RANGE MODELS ARE IN GOOD AGREEMENT ON THE L/W PATTERN ACROSS
THE CONUS LATE WEEK INTO THE WEEKEND... WHICH IS EXPECTED TO
CONTINUE TO FEATURE TROUGHING IN THE EAST AND RIDGING WEST.
HOWEVER... THE EAST COAST TROUGH IS EXPECTED TO DEEPEN LATE THIS
WEEK/EARLY NEXT WEEKEND AS THE AFOREMENTIONED STRONG S/W DIVES
SOUTH/SOUTHEASTWARD OUT OF CANADA LATE WEEK AND DEVELOP A CLOSED LOW
ACROSS THE GREAT LAKES/OHIO VALLEY REGION... RESULTING IN A DEEP
TROUGH ACROSS THE EASTERN U.S. FOR THIS TIME OF YEAR (YESTERDAY HPC
NOTED THAT HEIGHTS MAY AVERAGE 1.5 TO 2.0 STANDARD DEVIATIONS BELOW
CLIMATOLOGY ACROSS PORTIONS OF THE EASTERN U.S. DURING THIS
TIMEFRAME). AS THIS HAPPENS AN ASSOCIATED SURFACE FRONT IS EXPECTED
TO APPROACH THE AREA LATE THIS WEEK... WITH THE ACTUAL FRONT
FORECAST TO MOVE INTO THE AREA IN THE FRIDAY NIGHT TO SATURDAY
TIMEFRAME... BEFORE STALLING OUT AND EVENTUALLY DISSIPATING ACROSS
EASTERN PORTIONS OF THE AREA. GIVEN THE STRENGTH OF THE TROUGH ALOFT
THIS LOOKS REASONABLE. THIS SETUP FOR THIS TIME OF YEAR WOULD FAVOR
AN INCREASE CHANCE OF SOME ORGANIZED SEVERE STORMS ALONG WITH A GOOD
CHANCE FOR WIDESPREAD SHOWERS AND STORMS... GIVEN THE IMPROVING
LARGE SCALE LIFT. WITH REGARD TO THE SEVERE THREAT THE GFS HAS 1200
TO 2000 J/KG OF MLCAPE FOR FRIDAY AFTERNOON... WITH DEEP LAYER SHEAR
INCREASING INTO THE 25 TO 30 KT RANGE. GIVEN THE IMPROVING DEEP
LAYER SHEAR VALUES AND USUAL SUMMERTIME INSTABILITY SPC HAS PLACED
US IN THE DAY 4-8 OUTLOOK FOR INCREASED SEVERE POTENTIAL... WITH THE
MAIN SEVERE THREAT FROM DAMAGING WINDS AND LARGE HAIL. GIVEN PW`S OF
AROUND 2 INCHES AGAIN EXPECTED WITH THIS SYSTEM... FLASH FLOODING
MAY BE A THREAT IF A GIVEN LOCATIONS RECEIVES SEVERAL SHOWERS AND
STORMS... ESPECIALLY IN URBAN AREAS.
CHANCES FOR SHOWERS AND STORMS WILL LINGER INTO SATURDAY AND
SUNDAY... ESPECIALLY ACROSS EASTERN PORTIONS OF THE AREA AS THE
FRONT BEGINS TO STALL AND EVENTUALLY DISSIPATES BY THE END OF THE
WEEKEND. CHANCES FOR SHOWERS AND STORMS APPEAR TO INCREASE AGAIN BY
EARLY NEXT WEEK AS ANOTHER (MUCH WEAKER) UPPER LEVEL DISTURBANCE MAY
APPROACH THE REGION.
HIGH TEMPS DURING THE PERIOD ARE EXPECTED TO GENERALLY BE IN THE MID
TO UPPER 80S... WITH LOWS RANGING FROM THE MID 60S TO LOWER 70S
(WITH SOME LOCATIONS ACROSS THE NORTHWEST POSSIBLY DROPPING INTO THE
LOWER 60S ON SUNDAY MORNING).
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AS OF 728 AM TUESDAY...
A MID LEVEL TROUGH INTERACTING WITH THE VERY MOIST AIR OVER CENTRAL
NC WILL CAUSE SCATTERED TO NUMEROUS SHOWERS AND A FEW THUNDERSTORMS
ACROSS THE AREA THROUGH TONIGHT. THE GREATEST COVERAGE AND INTENSITY
WILL OCCUR DURING THE LATE MORNING THROUGH THE EARLY EVENING HOURS.
IN VICINITY OF THE HEAVIER SHOWERS AND T-STORMS...EXPECT MVFR
CONDITIONS WITH BRIEF PERIODS OF IFR CEILING/VISIBILITY.
BULK OF THE CONVECTION WILL DIMINISH OVER THE PIEDMONT INCLUDING
KRDU...KINT...AND KGSO BY MIDNIGHT...WHILE CONTINUE WELL INTO THE
NIGHT AT KRWI AND KFAY. EXPECT PATCHES OF IFR CEILING AND MVFR
VISIBILITY FOG TO DEVELOP OVER CENTRAL NC AFTER 06Z WED AND PERSIST
THROUGH 13Z WED.
ONCE MORNING STRATUS/FOG DIMINISH WEDNESDAY MORNING...EXPECT MAINLY
VFR CONDITIONS. CONVECTION COVERAGE EXPECTED TO BE LESS THAN TODAY
AND MAINLY DIURNALLY DRIVEN. SCATTERED CONVECTION LATE WEDNESDAY
AFTERNOON SHOULD DIMINISH WITHIN AN HOUR OR TWO AFTER SUNSET.
EXPECT A REPEAT PERFORMANCE THURSDAY WITH MORNING STRATUS AND FOG
GIVING WAY TO VFR CONDITIONS (ASIDE FROM LATE AFTERNOON CONVECTION).
ANOTHER MID-UPPER LEVEL TROUGH WITH AN ATTENDANT SURFACE BOUNDARY
WILL INCREASE THE THREAT FOR SCATTERED TO NUMEROUS SHOWERS AND
T-STORMS FRIDAY AFTERNOON INTO EARLY SATURDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...WSS/SMITH
SHORT TERM...WSS/BSD
LONG TERM...BSD
AVIATION...WSS
AREA FORECAST DISCUSSION
NWS NORMAN OK
507 AM CDT TUE AUG 7 2012
.DISCUSSION...
SATELLITE HAS SHOWN ACCAS DEVELOPING IN VARIOUS AREAS THIS
MORNING AND ASSOCIATED SHOWERS AND THUNDERSTORMS HAVE ALSO
DEVELOPED IN THE PAST FEW HOURS. HRRR IS ABOUT THE ONLY MODEL THAT
HAS SHOWED THIS DEVELOPMENT AND IT EXPECTS THIS CONVECTION TO
DISSIPATE LATE MORNING. WILL PROBABLY HAVE STORM REDEVELOPMENT
THIS AFTERNOON... BUT AGAIN DO NOT EXPECT THE STORMS TO BE VERY
WIDESPREAD. TODAY WILL BE ANOTHER HOT DAY BEFORE TEMPERATURES COME
COOL SLIGHTLY AS UPPER RIDGE SHIFTS TO THE WEST. HEAT INDICES WILL
BE MARGINAL FOR THE CURRENT HEAT ADVISORY... BUT WILL LET IT RIDE
FOR TODAY. WILL LIKELY SEE ISOLATED TO SCATTERED STORMS EACH
PERIOD THROUGH THURSDAY WHEN A FRONT MOVES THROUGH THE AREA.
FORECAST HIGHS THROUGH THE REMAINDER OF THE FORECAST PERIOD WILL
BE ABOVE AVERAGE... BUT NOT AS HIGH AS RECENT DAYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 104 74 100 74 / 20 30 20 20
HOBART OK 105 73 99 74 / 30 30 20 20
WICHITA FALLS TX 105 76 101 76 / 20 20 20 20
GAGE OK 102 69 97 68 / 30 30 20 10
PONCA CITY OK 104 71 96 73 / 20 20 20 20
DURANT OK 103 75 98 76 / 20 20 30 20
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...HEAT ADVISORY UNTIL 10 PM CDT THIS EVENING FOR OKZ039>048-
050>052.
TX...HEAT ADVISORY UNTIL 10 PM CDT THIS EVENING FOR TXZ086-089-090.
&&
$$
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
331 PM EDT TUE AUG 7 2012
.SYNOPSIS...
WEAK HIGH PRESSURE WILL REMAIN OFF THE COAST MIDWEEK...PERMITTING
SOUTHWEST FLOW TO BECOME ESTABLISHED. A COLD FRONT WILL ARRIVE LATE
FRIDAY INTO SATURDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
18Z SFC ANALYSIS SHOWS THE CENTER OF HIPRES HAS SHIFTED OFF THE
MID-ATLANTIC COAST. REMNANT SFC DEWPOINT BOUNDARY STRETCHING FROM
THE NRN PIEDMONT TO JUST SE OF I-95. THIS BOUNDARY WILL REMAIN
NEARLY STATIONARY THIS AFTN. DEWPOINTS IN THE LOW AND MID 60S RESIDE
NORTH AND WEST OF THE BOUNDARY...LOWER 70S TO THE SOUTH AND EAST.
BLENDED SAT AND RAP ANALYSIS SHOWED A TIGHT NW TO SE PWAT
GRADIENT...RANGING FROM UNDER INCH OVER THE ALLEGHENY FRONT TO JUST
UNDER TWO INCHES OVER THE SRN MD CHSPK BAY.
SCT SHOWERS AND TSTMS HAVE DEVELOPED ERY THIS AFTN SOUTH AND EAST OF
DC. EXPECT AN UPTICK IN THE ACTIVITY MID AFTN IN THIS MOIST/UNSTABLE
AIRMASS ALONG AND SOUTH/EAST OF THE BOUNDARY...WHERE MID-LVL LIFT IS
LOCATED AHEAD OF A WEAK SHORTWAVE TROUGH MOVING THRU SRN MD.
WITH LIGHT WINDS ALOFT...STORM MOTION WILL BE VERY WEAK. THE
SETUP SUPPORTS A LOCALIZED THREAT OF FLASH FLOODING IN THE NRN
PIEDMONT AND SRN MD. STILL CANNOT RULE OUT A PULSE SEVERE STORM OR
TWO GIVEN THE FAVORABLE ENVIRONMENT FOR A WET MICROBURST...
ALTHOUGH CLOUD COVER HAS LIMITED THE THREAT.
LGT SLY FLOW WILL OVERTAKE ENTIRE REGION TNGT AS HIPRES MOVES AWAY
FROM THE ERN SEABOARD. SIMILAR TO LAST NGT...CONVECTION WILL WANE
AFTER SUNSET...BUT A COUPLE OF SHOWERS AND STORMS MAY LINGER
OVNGT...ESPECIALLY IN SRN MD. ANOTHER MUGGY NGT IS EXPECTED WITH
MIN TEMPS IN THE 60S WELL NORTH AND WEST OF THE DC AND
BALTIMORE...LOW 70S IN THE NEARBY SUBURBS AND MID 70S IN THE CITIES.
THE DIFFUSE BOUNDARY WILL REMAIN OVER THE REGION WED...BUT SHOULD
START TO PROGRESS NWD. SHOWERS AND STORMS EXPECTED TO DEVELOP AGAIN
IN THE WARM/MOIST AIRMASS...ESPECIALLY EAST OF THE BLUE RIDGE. GIVEN
LACK OF SYNOPTIC LIFT... COVERAGE SHOULD BE ISO.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
AN UPPER-LEVEL TROUGH WILL APPROACH THE CWA DURING THE SECOND HALF
OF THE WORK WEEK. THIS WILL PRODUCE SHOWERS AND THUNDERSTORMS...SOME
OF WHICH COULD BE SEVERE...BOTH THURS AND FRI AFTERNOONS. CONTINUING
SOUTHWEST FLOW INTO THE AREA WILL MAINTAIN A WARM HUMID AIRMASS
THROUGH MIDWEEK. THIS COMBINED WITH THE PASSAGE OF A SHORTWAVE PRIOR
TO THE MAIN UPPER-TROUGH WILL PROVIDE SUFFICIENT LIFT FOR TSTMS
THURS AFTERNOON. BY FRI...A COLD FRONT LOOKS TO BE POSITIONED JUST
TO THE REGION/S WEST WITH ANOTHER WIDER SPREAD ROUND OF SEVERE
WEATHER IN THE AFTERNOON HOURS. BOTH DAYS HAVE BEEN OUTLOOKED BY SPC
WITH A SLIGHT RISK FOR THE CWA DURING DAYS 3 AND 4.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
GUIDANCE DEPICTS THE ACTUAL FRONT TRANSITIONING ACROSS THE AREA
DURING THE DAY SATURDAY WITH HIGH PRESSURE BUILDING IN BEHIND. THIS
WILL LOWER TEMPS BY 5-10 DEGREES TO VALUES A LITTLE COOLER THEN
NORMAL FOR THE BEGINNING OF AUGUST. PRECIP COULD LINGER THROUGH THE
DAY SATURDAY AS THE FRONT SLOWLY MOVES OFFSHORE. HOWEVER...THE
THREAT OF SEVERE STORMS WILL BE CONFINED TO THURS AND FRI. WIND WILL
SHIFT TO NORTHWEST BRINGING DRIER AIR INTO THE REGION FOR THE
BEGINNING OF THE WEEK. EXPECT MOSTLY DRY CONDITIONS WITH DAYTIME
HIGHS IN THE MID 80S AND LOWS IN THE MID 60S FOR SUN THROUGH TUE.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
MVFR AND IFR VSBYS ARE EXPECTED ACROSS AREA TERMINALS TONIGHT AS A
HUMID AIR MASS REMAINS OVER THE REGION. CHO SHOULD SEE THE BIGGEST
DROP IN VSBY AS THE AREA COULD SEE SOME SCATTERED SHOWERS AND
THUNDERSTORMS THIS AFTERNOON. ELSEWHERE WITH THE EXCEPTION OF
DCA...SHOULD SEE REDUCTIONS TO AROUND 3 SM. WIND WILL SLOWLY SHIFT
FROM NORTHEAST TO SOUTHWEST THROUGH THE TAF VALID PERIOD. THE
SOUTHWESTERLY SHIFT IN WIND DIRECTION WILL HELP TO MAINTAIN LOW
LEVEL BUT VFR CIGS THROUGH THE DAY TOMORROW.
AN UPPER LOW WILL DEEPEN OVER THE UPPER MIDWEST AND GREAT LAKES LATE
THIS WEEK WHILE AN ASSOCIATED COLD FRONT MOVES THRU FRI NGT OR SAT.
UNSETTLED WX WILL OCCUR DURING THIS TIME...WITH HIGH CHANCES FOR
PRECIP THU-SAT. SOME STORMS MAY BE STRONG DURING THE AFTN HRS THU
AND FRI. VSBY RESTRICTIONS IN STORMS LIKELY.
&&
.MARINE...
A RESIDUAL BOUNDARY REMAINS STATIONARY OVER THE CENTRAL MD CHSPK
BAY....WITH SLY FLOW OCCURRING SOUTH OF NORTH BEACH AND NELY FLOW TO
THE NORTH. THE BOUNDARY WILL SLOWLY LIFT NWD WED. ENHANCED SLY FLOW
DUE TO CHANNELING SOUTH OF THE BOUNDARY WILL STILL REMAIN BELOW SCA
THRESHOLD THRU WED. ISO SHOWERS AND STORMS MAY LINGER INTO THE
NGT...THOUGH NOT AS STRONG AND WIDESPREAD AS THIS AFTN. THREAT OF
STORMS CONTINUE WED.
LOPRES AND ASSOCIATED COLD FRONT WILL APPROACH FROM THE WEST THU
BEFORE MOVING THRU FRI AND SAT...RESULTING IN A PROLONGED PERIOD OF
SHOWERS AND STORMS DURING THIS TIME. SOME OF THE STORMS MAY BE
STRONG THU AND FRI AFTN.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
KLEIN/CLS
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1249 PM CDT TUE AUG 7 2012
...UPDATED AVIATION DISCUSSION...
.DISCUSSION...
Have raised afternoon temperatures by a few degrees owing to
presence of h8 thermal ridge overhead, plenty of sun and a boundary
layer that is once again drying out and allowing for super-adiabatic
lapse rates to occur near the surface. Also bumped up pops over far
northeast KS and parts of far nw MO due to new convection which
sprouted over northeast KS since 1645Z. None of the short range
convective models are handling the convection over KS. Using the
overall LSX local WRF, HRRR and NAM20 model trends suggest
convection should have a difficult time moving too far owing to a
very weak steering flow and relatively stable downstream airmass.
MJ
&&
.PREV DISCUSSION...
/337 AM CDT Tue Aug 7 2012/
Today through Thursday...
The main forecast challenge in the short term is precipitation
chances for this afternoon through Wednesday across the region. Both
the NAM and GFS break out convection this afternoon across eastern
Nebraska, where a subtle surface boundary creates minor lift for
initiation. The front will likely become more diffuse as it travels
southward, which will combine with an increasing capping inversion
to make precipitation unlikely in our area through late this
evening. However; in case thunderstorms that do develop track into
our far northwest this evening, edged some slight chances into our
far northwest before 06z Wednesday.
Currently, the highest probability for rainfall looks to be across
our far west after 06z Wednesday. A decent low level jet develops
across central Kansas and eastern Nebraska around midnight, while a
slight southeasterly turn to the low level wind field brings a bit
more moisture into play across the region. These ingredients could
support thunderstorm development or the enhancement of ongoing
convection in southeast Nebraska and northeast Kansas, which could
form an MCS that tracks through northwest Missouri early Wednesday
morning. A shortwave trough will approach the region around daybreak
on Wednesday, turning steering winds to the west southwest and
pushing any weakening activity across southern Iowa and far northern
Missouri, likely exiting the region around mid morning. As a result,
there will be a marginal severe weather threat across our northwest
early Wednesday morning if a well-formed MCS can develop and move
through the region.
By Wednesday afternoon, the shortwave will drop southeastward
through northern Missouri, possibly supporting broadly scattered
showers and thunderstorms across the CWA during the daytime. Without
appreciable surface focus for initiation and the mixing of low-level
moisture during the afternoon, the probability of precipitation
remains somewhat low, but is worth mentioning with decent midlevel
forcing. Models are a bit inconsistent on the speed of the wave and
its trajectory, but precipitation chances should taper off Wednesday
night from west to east, ending Thursday morning.
Temperatures during the period will depend on the coverage of clouds
and precipitation, but should be warmest today with mixing of mid
20s C 850 temperatures and only scattered midlevel clouds, then
cooler Wednesday and Thursday as the trough over the east deepens
and temperatures aloft cool.
Laflin
Medium Range (Friday - Monday)
The pattern during the extended forecast seems pretty slow to evolve
leaving the region in prolonged northwest flow. this should keep
temperatures at or possibly even below normal for the period. While
models show some precipitation chances over the weekend due to an
advancing shortwave, latest ECMWF shows our chances diminishing.
With atmospheric moisture limited, low to no pops is probably the
right choice. For now will go with the 15-20 pops the model blend
init gave, but wouldn`t be surprised to see us go dry for the
weekend over the next few days if the trend continues.
Bailey
&&
.FIRE WEATHER...
Much like Monday afternoon, very dry conditions are expected again
Tuesday afternoon as winds turn to the south at 5 to 10 knots.
Relative humidity values will once again fall to around 20% but
light winds will preclude widespread red flag conditions. However,
given the severity of the drought conditions, any increase in winds
will lead to substantially higher fire danger threats. Will continue
to issue an SPS for the elevated fire danger threat.
MJ
&&
.AVIATION...
For the 18z TAFs, expect VFR conditions overall during this forecast
period. Short range models not handling the current upstream
convection very well. However, weak steering flow suggests this
activity will be slow moving and pass west of KSTJ and likely not
reach the KMCI/KMKC terminals. Owing to much uncertainty in timing
and lack of confidence later in the forecast will use VCTS to
indicate potential of nearby storms and await better modeling or
established radar trends and amend if necessary. Better bet for
convection will most likely occur after 18z Wed.
MJ
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION
NWS RALEIGH NC
150 PM EDT TUE AUG 7 2012
.SYNOPSIS...
AN UPPER LEVEL TROUGH WILL DRIFT EAST ACROSS THE CAROLINAS AND
SOUTHERN VIRGINIA TODAY AND TONIGHT...AND LIE ALONG THE COASTAL
PLAIN ON WEDNESDAY. ANOTHER UPPER LEVEL TROUGH WILL AFFECT OUR
REGION FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM TUESDAY...
AREAS OF LIGHT TO MODERATE RAIN STRETCH FROM THE SOUTHERN PIEDMONT
TO THE NORTHERN COASTAL PLAIN THIS MORNING...ALONG A SHEARED OUT
VORTICITY AXIS NOTED IN WATER VAPOR AND RAP 500MB ANALYSIS. WHILE
ALL OF THE CWA OVERCAST...THE LOW STRATUS IS THICKEST OVER THE FROM
THE TRIANGLE WESTWARD TO THE TRIAD....AND VISIBLE SATELLITE IMAGERY
SHOWS A VEIL OF MID CLOUDS STREAMING ACROSS THE WESTERN HALF OF THE
STATE. THUS...EVEN AS THE STRATUS SLOWLY LIFTS THIS MORNING...SOME
AREAS MAY STRUGGLE TO GET OUT OF THE 70S...ESPECIALLY IN THOSE AREAS
WHERE RAIN FALLS THROUGH MIDDAY. SOME BREAKS IN CLOUD COVER ARE
BEGINNING TO SHOW OVER THE SOUTHERN COASTAL PLAIN...AND TEMPS COULD
REACH THE MID 80S FROM FAYETTEVILLE TO THE SOUTHEAST. WHILE
CONFIDENCE IN THE TEMP FORECAST IS LOW... HAVE ATTEMPTED TO ADJUST
TEMPS DOWNWARD OVER THE WESTERN PIEDMONT USING MET MOS AND NAM/GFS
RAW 2M TEMP FIELDS BASED...WHICH YIELDS VALUES ROUGHLY IN THE 79-85
RANGE.
REGARDING POPS...A WEAK UPPER LEVEL LOW AND ASSOCIATED VORT MAX OVER
AL/GA THIS MORNING WILL BE DRAWN NORTHWARD TODAY AHEAD OF AN UPPER
LEVEL TROUGH APPROACHING FROM THE MIDWEST. MEANWHILE.. A WEAK UPPER
JET OVER THE MID ATLANTIC STATES IS FORECAST TO BUILD BACK TO THE
SOUTHWEST ACROSS VA...WHICH SHOULD PROVIDE SOME RIGHT ENTRANCE
REGION LIFT AND ALSO HELP PRECIP EXPAND BACK TO THE NORTH OF THE
CURRENT PRECIP AXIS. MOST CAMS SUGGEST PRECIP WILL SHIFT NORTH
TOWARD ACROSS THE PIEDMONT THIS MORNING...THEN SHIFT EASTWARD TOWARD
THE COASTAL PLAIN LATER THIS AFTERNOON AND EVENING WITH THE SHEAR
AXIS. MOST OF THE WESTERN PIEDMONT SHOULD REMAIN RELATIVELY STABLE
AS COMPARED TO THE EASTERN PIEDMONT AND COASTAL PLAIN...WHERE
MODIFICATION OF THE 12Z KMHX RAOB SUGGEST 1000-1500 J/KG OF MLCAPE
IS POSSIBLE IF TEMPS CAN REACH THE MID 80S. DEEP LAYER SHEAR
FORECASTS CONTINUE TO BE BELOW 20KT...SO SEVERE POTENTIAL REMAINS
LOW AND WILL BE CONFINED TO STRONGER PULSE STORMS. HAVE MADE SOME
ADJUSTMENTS TO THE TIMING OF POPS THIS MORNING...BUT OVERALL THE
SHOWERS WILL BE NUMEROUS THIS AFTERNOON WITH SCATTERED STORMS AND
HEAVY RAIN MAINLY EAST.
FLASH FLOOD GUIDANCE HAS RECOVERED TO NORMAL VALUES FOR MOST AREAS
THIS MORNING. THE EXCEPTIONS APPEARS TO BE MAINLY RANDOLPH AND
STANLEY COUNTIES WHERE THE HEAVIEST RAIN FELL MONDAY. ONE TO TWO
INCHES IN AN HOUR OR TWO COULD CAUSE SOME FLOODING ISSUES IN THOSE
AREAS IF HEAVIER SHOWERS MATERIALIZE LATER TODAY. -SMITH
TONIGHT...BEST FOCUS FOR SHOWERS WILL BE ACROSS THE COASTAL PLAIN
THE FIRST HALF OF THE EVENING AS SHEAR AXIS DRIFTS EAST THOUGH
SHOULD SEE COVERAGE DECREASE BY MIDNIGHT AS AIR MASS STABILIZES AND
BEST LOW LEVEL MOISTURE TRANSPORT SHIFTS MORE TO THE IMMEDIATE COAST.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 AM TUESDAY...
WEDNESDAY AND WEDNESDAY NIGHT...WITH THE SHEAR AXIS CLOSER TO THE
COAST...EXPECT A RETURN TO MORE TYPICAL SUMMERTIME PATTERN OVER THE
PIEDMONT WITH RANDOM...DIURNALLY DRIVEN CONVECTION EXPECTED. SURFACE
PROJECTIONS SUGGEST A DEWPOINT GRADIENT BETWEEN THE TRIAD AND THE
TRIANGLE/FAY AREAS...SO EXPECT CONVECTION TO INITIATE ALONG THIS
FEATURE BY EARLY-MID AFTERNOON WITH CONVECTION DRIFTING EAST-SE.
THIS SUGGEST MORE COVERAGE IN THE SE VERSUS NW. PLAN TO HAVE POPS 30
PERCENT NW TO 50 PERCENT SE. PERIODS OF SUN PRIOR TO CONVECTION
INITIATION SHOULD LEAD TO AFTERNOON CLOSE TO NORMAL (UPPER 80S TO
AROUND 90). ANY CONVECTION WED EVENING SHOULD DIMINISH WITH LOSS OF
HEATING. PARTIAL CLEARING MAY ALLOW FOR THE DEVELOPMENT OF AREAS OF
FOG BY DAYBREAK THU. MIN TEMPS UPPER 60S TO LOWER 70S.-WSS
THURSDAY AND THURSDAY NIGHT:
BRIEF WESTERLY MID LEVEL FLOW IS EXPECTED TO AGAIN BACK TO
SOUTHWESTERLY ACROSS OUR AREA ON THURSDAY AS THE EAST COAST TROUGH
BEGINS TO DEEPEN AGAIN AS A STRONG S/W ALOFT DROPS
SOUTH/SOUTHEASTWARD OUT OF CANADA INTO THE UPPER MIDWEST AND GREAT
LAKES REGION. AT THE SURFACE MODELS INDICATE A SHARPENING
PIEDMONT/LEE SIDE TROUGH ACROSS THE AREA. BOTH NAM AND GFS BUFR
SOUNDINGS INDICATE A GOOD BIT OF DRY AIR IN THE MID LEVELS ALONG
WITH A WEAK CAP. HOWEVER... WITH SURFACE DEWPOINTS EXPECTED TO BE IN
THE UPPER 60S TO LOWER 70S (YIELDING MLCAPE IN THE 1500-2000 J/KG
RANGE FOR THE AFTERNOON) ALONG WITH THE SHARPENING SURFACE TROUGH
EXPECT WE WILL SEE SOME ISOLATED TO SCATTERED SHOWERS AND STORMS.
THUS... WILL CONTINUE A LOW END CHANCE FOR SHOWERS AND STORMS
THURSDAY AFTERNOON AND EVENING. WITH DEEP LAYER SHEAR AGAIN EXPECTED
TO REMAIN FAIRLY WEAK ON THE ORDER OF 15 TO 20 KTS DO NOT EXPECT ANY
ORGANIZED SEVERE WEATHER OUTBREAK. HOWEVER... A FEW STORMS MAY
BECOME STRONG TO SEVERE WITH THE MAIN THREAT OF DAMAGING DOWNBURST
WINDS AND MARGINALLY SEVERE HAIL. WITH LOW LEVEL THICKNESS VALUES
EXPECTED TO CLIMB TO AROUND 1420 METERS AND PARTLY SUNNY SKIES...
EXPECT WE WILL SE AFTERNOON HIGH TEMPS TOP OUT AROUND 90/LOWER 90S.
EXPECT CHANCES FOR SHOWERS AND STORMS TO DECREASE WITH THE LOSS OF
DAYTIME HEATING. OVERNIGHT LOWS ARE EXPECTED TO GENERALLY BE IN THE
LOWER 70S AGAIN... WITH PERHAPS A FEW OF THE URBAN AREAS REMAINING
IN THE MID 70S. -BSD
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 300 AM TUESDAY...
MEDIUM RANGE MODELS ARE IN GOOD AGREEMENT ON THE L/W PATTERN ACROSS
THE CONUS LATE WEEK INTO THE WEEKEND... WHICH IS EXPECTED TO
CONTINUE TO FEATURE TROUGHING IN THE EAST AND RIDGING WEST.
HOWEVER... THE EAST COAST TROUGH IS EXPECTED TO DEEPEN LATE THIS
WEEK/EARLY NEXT WEEKEND AS THE AFOREMENTIONED STRONG S/W DIVES
SOUTH/SOUTHEASTWARD OUT OF CANADA LATE WEEK AND DEVELOP A CLOSED LOW
ACROSS THE GREAT LAKES/OHIO VALLEY REGION... RESULTING IN A DEEP
TROUGH ACROSS THE EASTERN U.S. FOR THIS TIME OF YEAR (YESTERDAY HPC
NOTED THAT HEIGHTS MAY AVERAGE 1.5 TO 2.0 STANDARD DEVIATIONS BELOW
CLIMATOLOGY ACROSS PORTIONS OF THE EASTERN U.S. DURING THIS
TIMEFRAME). AS THIS HAPPENS AN ASSOCIATED SURFACE FRONT IS EXPECTED
TO APPROACH THE AREA LATE THIS WEEK... WITH THE ACTUAL FRONT
FORECAST TO MOVE INTO THE AREA IN THE FRIDAY NIGHT TO SATURDAY
TIMEFRAME... BEFORE STALLING OUT AND EVENTUALLY DISSIPATING ACROSS
EASTERN PORTIONS OF THE AREA. GIVEN THE STRENGTH OF THE TROUGH ALOFT
THIS LOOKS REASONABLE. THIS SETUP FOR THIS TIME OF YEAR WOULD FAVOR
AN INCREASE CHANCE OF SOME ORGANIZED SEVERE STORMS ALONG WITH A GOOD
CHANCE FOR WIDESPREAD SHOWERS AND STORMS... GIVEN THE IMPROVING
LARGE SCALE LIFT. WITH REGARD TO THE SEVERE THREAT THE GFS HAS 1200
TO 2000 J/KG OF MLCAPE FOR FRIDAY AFTERNOON... WITH DEEP LAYER SHEAR
INCREASING INTO THE 25 TO 30 KT RANGE. GIVEN THE IMPROVING DEEP
LAYER SHEAR VALUES AND USUAL SUMMERTIME INSTABILITY SPC HAS PLACED
US IN THE DAY 4-8 OUTLOOK FOR INCREASED SEVERE POTENTIAL... WITH THE
MAIN SEVERE THREAT FROM DAMAGING WINDS AND LARGE HAIL. GIVEN PW`S OF
AROUND 2 INCHES AGAIN EXPECTED WITH THIS SYSTEM... FLASH FLOODING
MAY BE A THREAT IF A GIVEN LOCATIONS RECEIVES SEVERAL SHOWERS AND
STORMS... ESPECIALLY IN URBAN AREAS.
CHANCES FOR SHOWERS AND STORMS WILL LINGER INTO SATURDAY AND
SUNDAY... ESPECIALLY ACROSS EASTERN PORTIONS OF THE AREA AS THE
FRONT BEGINS TO STALL AND EVENTUALLY DISSIPATES BY THE END OF THE
WEEKEND. CHANCES FOR SHOWERS AND STORMS APPEAR TO INCREASE AGAIN BY
EARLY NEXT WEEK AS ANOTHER (MUCH WEAKER) UPPER LEVEL DISTURBANCE MAY
APPROACH THE REGION.
HIGH TEMPS DURING THE PERIOD ARE EXPECTED TO GENERALLY BE IN THE MID
TO UPPER 80S... WITH LOWS RANGING FROM THE MID 60S TO LOWER 70S
(WITH SOME LOCATIONS ACROSS THE NORTHWEST POSSIBLY DROPPING INTO THE
LOWER 60S ON SUNDAY MORNING).
&&
.AVIATION /18Z TUESDAY THROUGH SATURDAY/...
AS OF 150 PM TUESDAY...
CEILINGS VARY ACROSS CENTRAL NC FROM MVFR TO VFR...BUT EVEN LOCALES
WITH VFR CONDITIONS STILL HAVE SCT STRATUS IN THE 1-3K FT RANGE.
EXPECT THESE CONDITIONS TO HOLD OR DETERIORATE THIS AFTERNOON AS
SHOWERS ISOLATED THUNDERSTORMS DEVELOP AND MOVE INTO THE AREA FROM
THE SOUTH. HEAVY RAIN AND PERIODS OF IFR/LIFR VSBYS WILL BE
POSSIBLE WITH THE HEAVIER SHOWERS...WHICH ARE MORE LIKELY AT
KRDU...KRWI...AND KFAY THROUGH MIDNIGHT. AFTER MIDNIGHT...MOST OF
THE SHOWERS AND STORMS WILL DIMINISH AND/OR MOVE EAST OF THE
AREA. HOWEVER...CEILINGS ARE LIKELY TO LOWER TO AT LEAST IFR
LEVELS AGAIN BY 09Z...WITH THE POSSIBILITY OF FOG GIVEN THE
WIDESPREAD RAIN IN THE PAST 24 HOURS.
IMPROVING CONDITIONS ARE EXPECTED FOR MUCH OF CENTRAL NC ON
WEDNESDAY. SCATTERED SHOWERS AND STORMS WILL BE POSSIBLE DURING THE
AFTERNOON HOURS...BUT CEILINGS SHOULD LIFT AND SCATTER BY LATE
MORNING AND HIGH END MVFR TO VFR CONDITIONS SHOULD PREVAIL FOR MANY
LOCATIONS.
AFTERNOON SHOWERS/STORMS AND MORNING STRATUS/FOG ARE AGAIN THURSDAY.
A STRONGER STORM SYSTEM WILL APPROACH THE AREA FRIDAY...LEADING TO
SCATTERED TO NUMEROUS SHOWERS AND T-STORMS FRIDAY AFTERNOON INTO
EARLY SATURDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...WSS/SMITH
SHORT TERM...WSS/BSD
LONG TERM...BSD
AVIATION...SMITH
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
1113 AM CDT TUE AUG 7 2012
.UPDATE...
EXPANDED THE HEAT ADVISORY FARTHER NORTH TO INCLUDE
THE OKLAHOMA CITY METRO...LAWTON...SHAWNEE...AND
STILLWATER AREAS. ALSO...MADE SMALL ADJUSTMENTS
TO OTHER ELEMENTS TODAY.
&&
.DISCUSSION...
VERY HOT AND MORE HUMID WEATHER WILL PREVAIL THIS
AFTERNOON WITH ISOLATED THUNDERSTORMS.
MADE THE CHANGES TO THE HEAT ADVISORY AS DEEPER MOISTURE
AND HUMIDITY WITH DEWPOINTS MAINLY IN THE LOWER TO MID 60S WILL
YIELD HIGHER HEAT INDEX VALUES THIS AFTERNOON ESPECIALLY SOUTHEAST
OF AN ALTUS TO PONCA CITY LINE. THE 12Z KOUN SOUNDING DEPICTED PW
OF 1.58 INCHES WHICH IS 124 OF NORMAL AND HIGHER THAN THE PAST
SEVERAL DAYS. HEAT INDICES IN THE 103 TO 109 RANGE ARE EXPECTED.
REGARDING RAIN CHANCES THIS AFTERNOON...ALTERED RAIN CHANCES TO
RESEMBLE THE LATEST HRRR RUNS. KEPT THE HIGHEST RAIN
CHANCES...AROUND 30 PERCENT...EAST OF I-35 WHERE APPEARS DEEPEST
MOISTURE AND WEAKEST CAPPING WILL OCCUR. NEARLY ANYWHERE CAN GET
WET...BUT DUE TO WEAK SHEAR...THINK MOST PLACES WILL REMAIN
RAINFREE.
ANY STORM THIS AFTERNOON MAY PRODUCE SEVERE DAMAGING WINDS OF 60
MPH OR GREATER DUE TO DCAPE VALUES 1200 TO 1800 J/KG. LOCALLY
HEAVY RAINFALL AND CLOUD TO GROUND LIGHTNING STRIKES ARE POSSIBLE
AS WELL WHICH MAY IGNITE FIRES.
AS FOR HIGHS THIS AFTERNOON...DID NOT ALTER THEM MUCH
DUE TO ONGOING CLOUD COVER AND CONVECTION. HOWEVER...THINK
THEY MAY BE TOO CONSERVATIVE. HIGHS MAY BE EVEN HOTTER THAN
CURRENTLY FORECAST...ESPECIALLY IF CLOUD COVER DECREASES.
PRODUCTS HAVE BEEN UPDATED.
MBS
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 104 74 100 74 / 20 30 20 20
HOBART OK 105 73 99 74 / 30 30 20 20
WICHITA FALLS TX 105 76 101 76 / 20 20 20 20
GAGE OK 102 69 97 68 / 20 30 20 10
PONCA CITY OK 104 71 96 73 / 30 20 20 20
DURANT OK 103 75 98 76 / 30 20 30 20
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...HEAT ADVISORY UNTIL 10 PM CDT THIS EVENING FOR OKZ012-013-
017>020-023>032-037>048-050>052.
TX...HEAT ADVISORY UNTIL 10 PM CDT THIS EVENING FOR TXZ086-089-090.
&&
$$
17/03
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
346 PM EDT TUE AUG 7 2012
.SYNOPSIS...
A PERIOD OF UNSETTLED WEATHER WILL CONTINUE THIS WEEK AS A FRONTAL
BOUNDARY OSCILLATES ACROSS THE MID ATLANTIC REGION. A STRONG COLD
FRONT WILL SWEEP ACROSS THE REGION ON FRIDAY...BRINGING A GENEROUS
COVERAGE OF SHOWERS AND STORMS...SOME POTENTIALLY STRONG. COOLER
AND DRIER WEATHER IS EXPECTED BY THE START OF THE NEXT WEEK AS
HIGH PRESSURE BUILDS INTO THE REGION.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 233 PM EDT TUESDAY...
A FRONTAL BOUNDARY WAS SLOWLY HEADING SOUTH THROUGH THE REGION. THE
FRONT...ALONG WITH DAYTIME HEATING...IS HELPING ISOLATED SHOWERS TO
DEVELOP THIS AFTERNOON NEAR THE CREST OF THE BLUE RIDGE FROM ROUGHLY
FLOYD VA...SOUTHWEST INTO THE NORTHERN MOUNTAINS OF NORTH CAROLINA.
OTHER ISOLATED SHOWERS WERE OVER PARTS OF THE MOUNTAIN EMPIRE REGION
OF SOUTHWEST VIRGINIA AND SOUTHSIDE VIRGINIA. THESE ARE EXPECTED TO
CONTINUE THROUGH THE AFTERNOON...AND PERHAPS INCREASE IN COVERAGE
AND GAIN A FEW STRIKES OF LIGHTNING. THIS FRONT WILL CONTINUE TO
SLOWLY HEAD SOUTH THROUGH THE NIGHT...SO THAT HIGH PRESSURE WILL BE
NOSING SOUTH INTO THE REGION BY WEDNESDAY.
THIS HIGH WILL BRING A TREND TOWARDS DECREASING CLOUDS OVERNIGHT
INTO EARLY WEDNESDAY MORNING. LIGHT WINDS...AND LINGERING BOUNDARY
LAYER MOISTURE BELOW THE NOCTURNAL INVERSION WILL HELP GENERATE
AREAS OF FOG TONIGHT ACROSS A GENEROUS PORTION OF THE AREA. WHILE
THERE IS BOUND TO BE SOME DENSE FOG...CONFIDENCE IN IT BEING
WIDESPREAD ARE NOT HIGH AT THIS TIME. WILL HIGHLIGHT THE POTENTIAL
FOR SOME DENSE FOG TONIGHT IN ALL BUT THE BLUEFIELD TO TAZEWELL
AREA. LOW TEMPERATURES TONIGHT WILL AVERAGE THREE TO FIVE DEGREES
COOLER THAN READINGS EXPERIENCED THIS MORNING.
ON WEDNESDAY...WE EXPECT ANOTHER DAY COMPARABLE TO TODAY AS FAR AS
PRECIPITATION COVERAGE THANKS TO THE FRONT JUST TO OUR SOUTH.
HOWEVER...WITH HIGH PRESSURE NOSING SOUTH...CLOUD COVER SHOULD BE
LESS...AND A SLIGHTLY STRONGER CAP SHOULD MEAN THE ISOLATED SHOWERS
SHOULD BE EVEN MORE ISOLATED. DESPITE THE FRONT BEING FARTHER TO OUR
SOUTH...MORE SUNSHINE SHOULD YIELD HIGH TEMPERATURES ON WEDNESDAY
ABOUT THREE TO FIVE DEGREES WARMER THAN TODAY.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
AS OF 242 PM EDT TUESDAY...
CHANCES FOR THUNDERSTORMS WILL INCREASE THROUGH THE SHORT TERM
PERIOD AS AN UPPER LEVEL TROF AMPLIFIES OVER THE GREAT LAKES AND
INTO THE OHIO VALLEY BY FRIDAY.
IN ADVANCE OF THIS SYSTEM...TEMPERATURES SHOULD WARM TOWARD THE
WARMER NAM MOS VALUES ON THURSDAY AS THE LOW LEVEL THERMAL RIDGE
NOSES INTO OUR AREA. BEST CHANCES FOR THUNDERSTORMS ON THURSDAY WILL
BE IN THE WEST AS A LEAD SHORT WAVE (OVERDONE BY THE GFS) APPROACHES
OUR AREA AND INTERACTS WITH A MODERATELY UNSTABLE AIRMASS. KEPT POPS
IN THE EASTERN PORTION OF THE FORECAST AREA ON THURSDAY AS WEAK LOW
LEVEL CONVERGENCE ALONG A LEE-SIDE TROF SHOULD GENERATE SCATTERED
CONVECTION.
THIS CONVECTION MAY LINGER A FEW HOURS BEYOND SUNDOWN THURSDAY NIGHT
WITH SUPPORT FROM THE WEAK UPPER LEVEL WAVE MOVING THROUGH.
THE TREND OF THE MODELS FOR FRIDAY`S SYSTEM HAS BEEN TO SLOW ITS
EASTWARD PROGRESS SLIGHTLY. BY 00Z (8 PM EDT) SATURDAY...MOST MODELS
SHOW THE COLD FRONT STILL WEST OF OUR FORECAST AREA. THE POTENTIAL
EXISTS FOR STRONG TO SEVERE STORMS TO ERUPT IN ADVANCE OF THIS
SYSTEM AS THE AREA COMES UNDER THE INFLUENCE OF THE RR QUAD OF AN
UPPER LEVEL JET ROTATING AROUND THE EASTERN SIDE OF THE APPROACHING
SHORT WAVE TROF. THE BIGGEST QUESTION CONCERNING THE POTENTIAL FOR
SEVERE WEATHER WILL BE THE INSTABILITY. CLOUDS ON FRIDAY SHOULD KEEP
HIGH TEMPS BELOW THURSDAY`S EXPECTED HIGHS AND MAY KEEP INSTABILITY
DOWN. THE GFS CRAVEN SIG SVR PARAMETER FORECAST KEEPS THE HIGHEST
POTENTIAL FOR SEVERE WEATHER TO OUR SOUTHEAST...WHERE INSTABILITY IS
FORECAST TO BE HIGHER. CONSIDERING THE STRENGTH OF THIS UPPER LEVEL
SYSTEM...WILL KEEP MENTION OF SVR WX IN THE HWO...ALONG WITH THE
THREAT FOR HEAVY RAIN WITH PWATS EXPECTED TO EXCEED 2 INCHES IN THE
EAST.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 242 PM EDT TUESDAY...
THE LONG RANGE MODELS ARE IN GOOD AGREEMENT THAT THE EASTERN U.S.
REMAINS UNDER THE INFLUENCE OF AN UPPER TROF THAT DE-AMPLIFIES WITH
TIME. AHEAD OF THE UPPER TROF...A STRONG COLD FRONT WILL SWEEP
THROUGH FRIDAY NIGHT. THE 00Z ECMWF HOLDS MORE UPPER LEVEL ENERGY ON
THE WEST SIDE OF THE UPPER TROF AND KEEPS PRECIP LINGERING IN THE
FAR EASTERN PORTION OF OUR FORECAST AREA ON SATURDAY. SO WE HAVE
DELAYED THE ENDING TIME OF THE PRECIP UNTIL MIDDAY SATURDAY.
OTHERWISE...UPSLOPE RAIN SHOWERS CAN BE EXPECTED UNDER THE TROF AXIS
AND LOW LEVEL NORTHWEST WINDS.
DRIER...COOLER AND LESS HUMID AIR WILL INVADE THE REGION LATE
SATURDAY INTO SUNDAY. THE GEFS SHOWS 850MB TEMPS BY 18Z SATURDAY
WILL BE 1-2 STANDARD DEVIATIONS BELOW NORMAL. SO...LEANED TOWARD THE
COOLER ECMWF VALUES FOR TEMPS SATURDAY NIGHT THROUGH SUNDAY NIGHT.
TEMPERATURES WILL GRADUALLY WARM MONDAY AND TUESDAY AS THE UPPER
LEVEL TROF RELAXES...BUT INDIVIDUAL SHORT WAVES MOVING THROUGH AN
UPPER LEVEL NORTHWEST FLOW COMBINED WITH A WEAK SOUTHEAST FLOW WILL
GENERATE AFTERNOON SHOWERS AND STORMS.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
AS OF 132 PM EDT TUESDAY...
MAINLY VFR CONDITIONS EXIST ALONG AND NORTH OF KBLF-KFCX LINE THIS
AFTERNOON...WITH PATCHY MVFR CIGS SOUTH OF THIS LINE. EXPECTING
CIGS TO TREND TO VFR AT ALL LOCATIONS BY LATE THIS AFTERNOON.
ISOLATED SHOWERS AND STORMS ALSO POSSIBLE MAINLY ALONG AND SOUTH
OF THE NC/VA BORDER THROUGH THE AFTERNOON. TONIGHT...ISOLATED
CONVECTION WILL CONTINUE INTO THE EVENING. MANY AREAS WILL SEE
VALLEY AND RIVER FOG DEVELOPING OVERNIGHT...WITH MOSTS AREAS MVFR
FOR VSBYS BY SURNISE WITH ISOLATED IFR OR LOWER. VLIFR/LIFR CIGS
AREA ALSO POSSIBLE WITHIN THE VALLEYS. ANY SUB-VFR CONDITIONS
SHOULD IMPROVE TO VFR BY 13-14Z...9-10AM...WEDNESDAY
A FRONTAL BOUNDARY WILL HOVER AROUND THE REGION THROUGH THE
WEEKEND WITH PERIODIC WAVES OF ENERGY RIDING ALONG IT. LOOK FOR AT
LEAST ISOLATED DIURNAL CONVECTION DURING THIS TIME PERIOD...WITH
FRIDAY INTO SATURDAY HAVING A BETTER CHANCE OF ORGANIZED
CONVECTION AS A LOW DEVELOPS OVER THE MIDWEST AND EJECTS THE FRONT
EASTWARD AS A STRONG COLD FRONT. LATE NIGHT/EARLY MORNING MOUNTAIN
AND RIVER VALLY FOG IS ALSO EXPECTED MOST NIGHTS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...DS
NEAR TERM...DS
SHORT TERM...PH
LONG TERM...PH
AVIATION...DS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
300 PM EDT TUE AUG 7 2012
.SYNOPSIS...
A PERIOD OF UNSETTLED WEATHER WILL CONTINUE THIS WEEK AS A FRONTAL
BOUNDARY OSCILATES ACROSS THE MID ATLANTIC REGION. A STRONG COLD
FRONT WILL SWEEP ACROSS THE REGION ON FRIDAY...BRINGING A GENEROUS
COVERAGE OF SHOWERS AND STORMS...SOME POTENTIALLY STRONG. COOLER
AND DRIER WEATHER IS EXPECTED BY THE START OF THE NEXT WEEK AS
HIGH PRESSURE BUILDS INTO THE REGION.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 233 PM EDT TUESDAY...
A FRONTAL BOUNDARY WAS SLOWLY HEADING SOUTH THROUGH THE REGION. THE
FRONT...ALONG WITH DAYTIME HEATING...IS HELPING ISOLATED SHOWERS TO
DEVELOP THIS AFTERNOON NEAR THE CREST OF THE BLUE RIDGE FROM ROUGHLY
FLOYD VA...SOUTHWEST INTO THE NORTHERN MOUNTAINS OF NORTH CAROLINA.
OTHER ISOLATED SHOWERS WERE OVER PARTS OF THE MOUNTAIN EMPIRE REGION
OF SOUTHWEST VIRGINIA AND SOUTHSIDE VIRGINIA. THESE ARE EXPECTED TO
CONTINUE THROUGH THE AFTERNOON...AND PERHAPS INCREASE IN COVERAGE
AND GAIN A FEW STRIKES OF LIGHTNING. THIS FRONT WILL CONTINUE TO
SLOWLY HEAD SOUTH THROUGH THE NIGHT...SO THAT HIGH PRESSURE WILL BE
NOSING SOUTH INTO THE REGION BY WEDNESDAY.
THIS HIGH WILL BRING A TREND TOWARDS DECREASING CLOUDS OVERNIGHT
INTO EARLY WEDNESDAY MORNING. LIGHT WINDS...AND LINGERING BOUNDARY
LAYER MOISTURE BELOW THE NOCTURNAL INVERSION WILL HELP GENERATE
AREAS OF FOG TONIGHT ACROSS A GENEROUS PORTION OF THE AREA. WHILE
THERE IS BOUND TO BE SOME DENSE FOG...CONFIDENCE IN IT BEING
WIDESPREAD ARE NOT HIGH AT THIS TIME. WILL HIGHLIGHT THE POTENTIAL
FOR SOME DENSE FOG TONIGHT IN ALL BUT THE BLUEFIELD TO TAZEWELL
AREA. LOW TEMPERATURES TONIGHT WILL AVERAGE THREE TO FIVE DEGREES
COOLER THAN READINGS EXPERIENCED THIS MORNING.
ON WEDNESDAY...WE EXPECT ANOTHER DAY COMPARABLE TO TODAY AS FAR AS
PRECIPITATION COVERAGE THANKS TO THE FRONT JUST TO OUR SOUTH.
HOWEVER...WITH HIGH PRESSURE NOSING SOUTH...CLOUD COVER SHOULD BE
LESS...AND A SLIGHTLY STRONGER CAP SHOULD MEAN THE ISOLATED SHOWERS
SHOULD BE EVEN MORE ISOLATED. DESPITE THE FRONT BEING FARTHER TO OUR
SOUTH...MORE SUNSHINE SHOULD YIELD HIGH TEMPERATURES ON WEDNESDAY
ABOUT THREE TO FIVE DEGREES WARMER THAN TODAY.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
AS OF 242 PM EDT TUESDAY...
CHANCES FOR THUNDERSTORMS WILL INCREASE THROUGH THE SHORT TERM
PERIOD AS AN UPPER LEVEL TROF AMPLIFIES OVER THE GREAT LAKES AND
INTO THE OHIO VALLEY BY FRIDAY.
IN ADVANCE OF THIS SYSTEM...TEMPERATURES SHOULD WARM TOWARD THE
WARMER NAM MOS VALUES ON THURSDAY AS THE LOW LEVEL THERMAL RIDGE
NOSES INTO OUR AREA. BEST CHANCES FOR THUNDERSTORMS ON THURSDAY WILL
BE IN THE WEST AS A LEAD SHORT WAVE (OVERDONE BY THE GFS) APPROACHES
OUR AREA AND INTERACTS WITH A MODERATELY UNSTABLE AIRMASS. KEPT POPS
IN THE EASTERN PORTION OF THE FORECAST AREA ON THURSDAY AS WEAK LOW
LEVEL CONVERGENCE ALONG A LEE-SIDE TROF SHOULD GENERATE SCATTERED
CONVECTION.
THIS CONVECTION MAY LINGER A FEW HOURS BEYOND SUNDOWN THURSDAY NIGHT
WITH SUPPORT FROM THE WEAK UPPER LEVEL WAVE MOVING THROUGH.
THE TREND OF THE MODELS FOR FRIDAY`S SYSTEM HAS BEEN TO SLOW ITS
EASTWARD PROGRESS SLIGHTLY. BY 00Z (8 PM EDT) SATURDAY...MOST MODELS
SHOW THE COLD FRONT STILL WEST OF OUR FORECAST AREA. THE POTENTIAL
EXISTS FOR STRONG TO SEVERE STORMS TO ERUPT IN ADVANCE OF THIS
SYSTEM AS THE AREA COMES UNDER THE INFLUENCE OF THE RR QUAD OF AN
UPPER LEVEL JET ROTATING AROUND THE EASTERN SIDE OF THE APPROACHING
SHORT WAVE TROF. THE BIGGEST QUESTION CONCERNING THE POTENTIAL FOR
SEVERE WEATHER WILL BE THE INSTABILITY. CLOUDS ON FRIDAY SHOULD KEEP
HIGH TEMPS BELOW THURSDAY`S EXPECTED HIGHS AND MAY KEEP INSTABILITY
DOWN. THE GFS CRAVEN SIG SVR PARAMETER FORECAST KEEPS THE HIGHEST
POTENTIAL FOR SEVERE WEATHER TO OUR SOUTHEAST...WHERE INSTABILITY IS
FORECAST TO BE HIGHER. CONSIDERING THE STRENGTH OF THIS UPPER LEVEL
SYSTEM...WILL KEEP MENTION OF SVR WX IN THE HWO...ALONG WITH THE
THREAT FOR HEAVY RAIN WITH PWATS EXPECTED TO EXCEED 2 INCHES IN THE
EAST.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 242 PM EDT TUESDAY...AS OF 233 PM EDT TUESDAY...
A FRONTAL BOUNDARY WAS SLOWLY HEADING SOUTH THROUGH THE REGION. THE
FRONT...ALONG WITH DAYTIME HEATING...IS HELPING ISOLATED SHOWERS TO
DEVELOP THIS AFTERNOON NEAR THE CREST OF THE BLUE RIDGE FROM ROUGHLY
FLOYD VA...SOUTHWEST INTO THE NORTHERN MOUNTAINS OF NORTH CAROLINA.
OTHER ISOLATED SHOWERS WERE OVER PARTS OF THE MOUNTAIN EMPIRE REGION
OF SOUTHWEST VIRGINIA AND SOUTHSIDE VIRGINIA. THESE ARE EXPECTED TO
CONTINUE THROUGH THE AFTERNOON...AND PERHAPS INCREASE IN COVERAGE
AND GAIN A FEW STRIKES OF LIGHTNING. THIS FRONT WILL CONTINUE TO
SLOWLY HEAD SOUTH THROUGH THE NIGHT...SO THAT HIGH PRESSURE WILL BE
NOSING SOUTH INTO THE REGION BY WEDNESDAY.
THIS HIGH WILL BRING A TREND TOWARDS DECREASING CLOUDS OVERNIGHT
INTO EARLY WEDNESDAY MORNING. LIGHT WINDS...AND LINGERING BOUNDARY
LAYER MOISTURE BELOW THE NOCTURNAL INVERSION WILL HELP GENERATE
AREAS OF FOG TONIGHT ACROSS A GENEROUS PORTION OF THE AREA. WHILE
THERE IS BOUND TO BE SOME DENSE FOG...CONFIDENCE IN IT BEING
WIDESPREAD ARE NOT HIGH AT THIS TIME. WILL HIGHLIGHT THE POTENTIAL
FOR SOME DENSE FOG TONIGHT IN ALL BUT THE BLUEFIELD TO TAZEWELL
AREA. LOW TEMPERATURES TONIGHT WILL AVERAGE THREE TO FIVE DEGREES
COOLER THAN READINGS EXPERIENCED THIS MORNING.
ON WEDNESDAY...WE EXPECT ANOTHER DAY COMPARABLE TO TODAY AS FAR AS
PRECIPITATION COVERAGE THANKS TO THE FRONT JUST TO OUR SOUTH.
HOWEVER...WITH HIGH PRESSURE NOSING SOUTH...CLOUD COVER SHOULD BE
LESS...AND A SLIGHTLY STRONGER CAP SHOULD MEAN THE ISOLATED SHOWERS
SHOULD BE EVEN MORE ISOLATED. DESPITE THE FRONT BEING FARTHER TO OUR
SOUTH...MORE SUNSHINE SHOULD YIELD HIGH TEMPERATURES ON WEDNESDAY
ABOUT THREE TO FIVE DEGREES WARMER THAN TODAY.
THE LONG RANGE MODELS ARE IN GOOD AGREEMENT THAT THE EASTERN U.S.
REMAINS UNDER THE INFLUENCE OF AN UPPER TROF THAT DE-AMPLIFIES WITH
TIME. AHEAD OF THE UPPER TROF...A STRONG COLD FRONT WILL SWEEP
THROUGH FRIDAY NIGHT. THE 00Z ECMWF HOLDS MORE UPPER LEVEL ENERGY ON
THE WEST SIDE OF THE UPPER TROF AND KEEPS PRECIP LINGERING IN THE
FAR EASTERN PORTION OF OUR FORECAST AREA ON SATURDAY. SO WE HAVE
DELAYED THE ENDING TIME OF THE PRECIP UNTIL MIDDAY SATURDAY.
OTHERWISE...UPSLOPE RAIN SHOWERS CAN BE EXPECTED UNDER THE TROF AXIS
AND LOW LEVEL NORTHWEST WINDS.
DRIER...COOLER AND LESS HUMID AIR WILL INVADE THE REGION LATE
SATURDAY INTO SUNDAY. THE GEFS SHOWS 850MB TEMPS BY 18Z SATURDAY
WILL BE 1-2 STANDARD DEVIATIONS BELOW NORMAL. SO...LEANED TOWARD THE
COOLER ECMWF VALUES FOR TEMPS SATURDAY NIGHT THROUGH SUNDAY NIGHT.
TEMPERATURES WILL GRADUALLY WARM MONDAY AND TUESDAY AS THE UPPER
LEVEL TROF RELAXES...BUT INDIVIDUAL SHORT WAVES MOVING THROUGH AN
UPPER LEVEL NORTHWEST FLOW COMBINED WITH A WEAK SOUTHEAST FLOW WILL
GENERATE AFTERNOON SHOWERS AND STORMS.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
AS OF 132 PM EDT TUESDAY...
MAINLY VFR CONDITIONS EXIST ALONG AND NORTH OF KBLF-KFCX LINE THIS
AFTERNOON...WITH PATCHY MVFR CIGS SOUTH OF THIS LINE. EXPECTING
CIGS TO TREND TO VFR AT ALL LOCATIONS BY LATE THIS AFTERNOON.
ISOLATED SHOWERS AND STORMS ALSO POSSIBLE MAINLY ALONG AND SOUTH
OF THE NC/VA BORDER THROUGH THE AFTERNOON. TONIGHT...ISOLATED
CONVECTION WILL CONTINUE INTO THE EVENING. MANY AREAS WILL SEE
VALLEY AND RIVER FOG DEVELOPING OVERNIGHT...WITH MOSTS AREAS MVFR
FOR VSBYS BY SURNISE WITH ISOLATED IFR OR LOWER. VLIFR/LIFR CIGS
AREA ALSO POSSIBLE WITHIN THE VALLEYS. ANY SUB-VFR CONDITIONS
SHOULD IMPROVE TO VFR BY 13-14Z...9-10AM...WEDNESDAY
A FRONTAL BOUNDARY WILL HOVER AROUND THE REGION THROUGH THE
WEEKEND WITH PERIODIC WAVES OF ENERGY RIDING ALONG IT. LOOK FOR AT
LEAST ISOLATED DIURNAL CONVECTION DURING THIS TIME PERIOD...WITH
FRIDAY INTO SATURDAY HAVING A BETTER CHANCE OF ORGANIZED
CONVECTION AS A LOW DEVELOPS OVER THE MIDWEST AND EJECTS THE FRONT
EASTWARD AS A STRONG COLD FRONT. LATE NIGHT/EARLY MORNING MOUNTAIN
AND RIVER VALLY FOG IS ALSO EXPECTED MOST NIGHTS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...DS
NEAR TERM...DS
SHORT TERM...PH
LONG TERM...PH
AVIATION...DS