Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/21/15
AREA FORECAST DISCUSSION
NWS TUCSON AZ
938 AM MST WED AUG 19 2015
.SYNOPSIS...EXPECT ISOLATED THUNDERSTORMS NEAR THE INTERNATIONAL
BORDER SOUTHEAST OF TUCSON THIS AFTERNOON AND EVENING...AND ISOLATED
THUNDERSTORMS FROM TUCSON EAST AND SOUTH THURSDAY. SIGNIFICANTLY
GREATER CHANCES FOR SHOWERS AND THUNDERSTORMS WILL THEN OCCUR FRIDAY
AND CONTINUE INTO EARLY NEXT WEEK. A GRADUAL COOLING TREND WILL
PREVAIL THROUGH FRIDAY FOLLOWED BY NEAR NORMAL DAYTIME TEMPERATURES
THIS WEEKEND AND EARLY NEXT WEEK.
&&
.DISCUSSION...SIMILAR WEATHER CONDITIONS AS YESTERDAY CAN BE
ANTICIPATED FOR TODAY. MODELS STILL SUGGEST AN INCREASE IN
THUNDERSTORM ACTIVITY RETURNING TO THE AREA FRIDAY INTO EARLY NEXT
WEEK AS THE FLOW PATTERN BECOMES MORE FAVORABLE. CURRENT FORECAST
LOOKED ON TRACK...SO NO UPDATES NECESSARY THIS MORNING. PLEASE REFER
TO THE ADDITIONAL SECTIONS FOR MORE DETAILS.
&&
.AVIATION...VALID THRU 20/06Z.
SCT CIRRUS CLOUDS UNDER NW FLOW ALOFT OTRW CLR. AFT 19/21Z FEW-SCT 8-
10KFT WITH SLGT CHC OF TSTMS OVER MTNS WELL SE OF KTUS. LIGHT
TERRAIN DRIVEN WINDS EXCEPT NW 15-20 KTS SAFFORD VALLEY. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...GENERALLY DRY CONDITIONS ARE EXPECTED WITH POSSIBLE
EXCEPTION OF AN ISOLATED THUNDERSTORM FAR SOUTHERN PART OF ZONE 152
LATE TODAY. MIN RH LEVELS TODAY WILL BE THE LOWEST OF THE WEEK AND
BOTTOM OUT IN THE 15-25 PERCENT RANGE ACROSS LOWER ELEVATIONS WITH A
DECENT AFTERNOON BREEZE AGAIN THIS AFTERNOON. THE WIND WILL BE
STRONGEST IN THE GILA VALLEY ALTHOUGH A FEW MPH LESS THAN YESTERDAY.
MOISTURE WILL BEGIN TO INCREASE THURSDAY WITH ISOLATED SHOWERS AND
THUNDERSTORMS POSSIBLE...MAINLY SOUTHERN AREAS. THEN THE MOISTURE
AND THUNDERSTORMS CHANCES WILL INCREASE AND SPREAD THROUGHOUT
SOUTHEAST ARIZONA THROUGH THE WEEKEND INTO EARLY NEXT WEEK.
&&
.PREV DISCUSSION...NWLY FLOW ALOFT CONTINUES ACROSS SE ARIZONA EARLY
THIS MORNING WITH HIGH PRESSURE CENTERED NEAR THE SOUTHERN
CALIFORNIA COAST. PRECIP-FREE CONDITIONS WILL OCCUR ACROSS MUCH OF
THIS FORECAST AREA THRU TONIGHT. HOWEVER...HAVE OPTED TO INTRODUCE A
SLIGHT CHANCE OF SHOWERS/TSTMS THIS AFTERNOON AND EVENING ACROSS SRN
PORTIONS OF COCHISE COUNTY...AND THE ERN PORTION OF SANTA CRUZ
COUNTY. SEVERAL HRRR SOLUTIONS AS WELL AS THE 19/06Z NAM12 DEPICT
THE BEST CHANCE FOR MEASURABLE RAINFALL TO OCCUR ACROSS THE HUACHUCA
MOUNTAINS. ANY SHOWERS/TSTMS SHOULD DISSIPATE AROUND SUNSET OR
SHORTLY THEREAFTER.
THE UPPER HIGH IS THEN PROGGED VIA THE 19/00Z NAM/GFS/ECMWF/CMC TO
WEAKEN ON THUR...AND THE NEAR-SURFACE FLOW REGIME IS PROGGED TO
BECOME INCREASINGLY SLY/SELY...ESPECIALLY BY THUR NIGHT. HAVE
MAINTAINED ISOLATED SHOWERS/TSMTS MAINLY FROM TUCSON EWD/SWD THUR
AFTERNOON INTO THUR NIGHT. MOISTURE WILL CONTINUE TO INCREASE ACROSS
THE AREA FRI AS HIGH PRESSURE ALOFT BECOMES POSITIONED OVER FAR WEST
TEXAS.
THUS...HAVE INCREASED POPS GENERALLY 10-20 PERCENT FRI ESPECIALLY
FROM TUCSON EAST AND SOUTH VERSUS THE INHERITED FORECAST. HOWEVER
POPS FOR FRI AFTERNOON/EVENING ARE STILL SOMEWHAT LOW RELATIVE TO
SOME GUIDANCE SUCH AS THE GFSX/ECMX. AT ANY RATE...SCATTERED
SHOWERS/TSTMS SHOULD OCCUR ACROSS MUCH OF THE AREA FRI AFTERNOON/
EVENING...WITH ISOLATED SHOWERS/TSTMS ACROSS WRN SECTIONS.
SOME DECREASE IN THE COVERAGE OF SHOWERS/TSTMS IS EXPECTED SAT GIVEN
THE PROGGED VERY LIGHT MID/UPPER LEVEL FLOW REGIME. THE POTENTIAL
THEN EXISTS FOR A FAIRLY SIGNIFICANT INCREASE IN SHOWERS/TSTMS SUN-
MON DUE TO A DEEPER SELY FLOW REGIME. THE GFS/ECMWF WERE ALSO
SIMILAR WITH DEPICTING AN INVERTED TROUGH TO ENCROACH UPON FAR SERN
SECTIONS SUN NIGHT/EARLY MON. AT ANY RATE...POPS WERE TRENDED UPWARD
BASED ON THE 19/00Z GFS/ECMWF/CMC SOLUTIONS TO REFLECT THIS NOTION.
THEREAFTER...ADEQUATE MOISTURE SUGGESTS THE CONTINUATION OF CHANCE-
CATEGORY POPS ACROSS MUCH OF SE ARIZONA MON NIGHT-TUE.
HIGH TEMPS TODAY WILL BE QUITE SIMILAR TO TEMPS ACHIEVED TUE...AND
WILL AVERAGE ABOUT 2-6 DEGS F ABOVE NORMAL. SOME MINOR DAILY COOLING
WILL THEN OCCUR THUR-FRI FOLLOWED BY NEAR NORMAL DAYTIME TEMPS FOR
MUCH OF THE AREA SAT-TUE.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS TUCSON AZ
350 AM MST WED AUG 19 2015
.SYNOPSIS...EXPECT ISOLATED THUNDERSTORMS NEAR THE INTERNATIONAL
BORDER SOUTHEAST OF TUCSON THIS AFTERNOON AND EVENING...AND ISOLATED
THUNDERSTORMS FROM TUCSON EAST AND SOUTH THURSDAY. SIGNIFICANTLY
GREATER CHANCES FOR SHOWERS AND THUNDERSTORMS WILL THEN OCCUR FRIDAY
AND CONTINUE INTO EARLY NEXT WEEK. A GRADUAL COOLING TREND WILL
PREVAIL THROUGH FRIDAY FOLLOWED BY NEAR NORMAL DAYTIME TEMPERATURES
THIS WEEKEND AND EARLY NEXT WEEK.
&&
.DISCUSSION...NWLY FLOW ALOFT CONTINUES ACROSS SE ARIZONA EARLY THIS
MORNING WITH HIGH PRESSURE CENTERED NEAR THE SOUTHERN CALIFORNIA
COAST. PRECIP-FREE CONDITIONS WILL OCCUR ACROSS MUCH OF THIS
FORECAST AREA THRU TONIGHT. HOWEVER...HAVE OPTED TO INTRODUCE A
SLIGHT CHANCE OF SHOWERS/TSTMS THIS AFTERNOON AND EVENING ACROSS SRN
PORTIONS OF COCHISE COUNTY...AND THE ERN PORTION OF SANTA CRUZ
COUNTY. SEVERAL HRRR SOLUTIONS AS WELL AS THE 19/06Z NAM12 DEPICT
THE BEST CHANCE FOR MEASURABLE RAINFALL TO OCCUR ACROSS THE HUACHUCA
MOUNTAINS. ANY SHOWERS/TSTMS SHOULD DISSIPATE AROUND SUNSET OR
SHORTLY THEREAFTER.
THE UPPER HIGH IS THEN PROGGED VIA THE 19/00Z NAM/GFS/ECMWF/CMC TO
WEAKEN ON THUR...AND THE NEAR-SURFACE FLOW REGIME IS PROGGED TO
BECOME INCREASINGLY SLY/SELY...ESPECIALLY BY THUR NIGHT. HAVE
MAINTAINED ISOLATED SHOWERS/TSMTS MAINLY FROM TUCSON EWD/SWD THUR
AFTERNOON INTO THUR NIGHT. MOISTURE WILL CONTINUE TO INCREASE ACROSS
THE AREA FRI AS HIGH PRESSURE ALOFT BECOMES POSITIONED OVER FAR WEST
TEXAS.
THUS...HAVE INCREASED POPS GENERALLY 10-20 PERCENT FRI ESPECIALLY
FROM TUCSON EAST AND SOUTH VERSUS THE INHERITED FORECAST. HOWEVER
POPS FOR FRI AFTERNOON/EVENING ARE STILL SOMEWHAT LOW RELATIVE TO
SOME GUIDANCE SUCH AS THE GFSX/ECMX. AT ANY RATE...SCATTERED
SHOWERS/TSTMS SHOULD OCCUR ACROSS MUCH OF THE AREA FRI AFTERNOON/
EVENING...WITH ISOLATED SHOWERS/TSTMS ACROSS WRN SECTIONS.
SOME DECREASE IN THE COVERAGE OF SHOWERS/TSTMS IS EXPECTED SAT GIVEN
THE PROGGED VERY LIGHT MID/UPPER LEVEL FLOW REGIME. THE POTENTIAL
THEN EXISTS FOR A FAIRLY SIGNIFICANT INCREASE IN SHOWERS/TSTMS SUN-
MON DUE TO A DEEPER SELY FLOW REGIME. THE GFS/ECMWF WERE ALSO
SIMILAR WITH DEPICTING AN INVERTED TROUGH TO ENCROACH UPON FAR SERN
SECTIONS SUN NIGHT/EARLY MON. AT ANY RATE...POPS WERE TRENDED UPWARD
BASED ON THE 19/00Z GFS/ECMWF/CMC SOLUTIONS TO REFLECT THIS NOTION.
THEREAFTER...ADEQUATE MOISTURE SUGGESTS THE CONTINUATION OF CHANCE-
CATEGORY POPS ACROSS MUCH OF SE ARIZONA MON NIGHT-TUE.
HIGH TEMPS TODAY WILL BE QUITE SIMILAR TO TEMPS ACHIEVED TUE...AND
WILL AVERAGE ABOUT 2-6 DEGS F ABOVE NORMAL. SOME MINOR DAILY COOLING
WILL THEN OCCUR THUR-FRI FOLLOWED BY NEAR NORMAL DAYTIME TEMPS FOR
MUCH OF THE AREA SAT-TUE.
&&
.AVIATION...VALID THRU 20/00Z.
SCT TO BKN CIRRUS CLOUDS UNDER NW FLOW ALOFT OTRW CLR. AFT 19/19Z
FEW-SCT 8-10KFT WITH SLGT CHC OF TSTMS OVER MTNS WELL SE OF KTUS.
LIGHT TERRAIN DRIVEN WINDS EXCEPT NW WIND 5-12 KTS IN THE SAFFORD
VALLEY THEN AFT 19/19Z WIND BECOMING W TO NW 8-15 KTS EXCEPT 15-20
KTS SAFFORD VALLEY. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.
&&
.FIRE WEATHER...GENERALLY DRY CONDITIONS ARE EXPECTED WITH POSSIBLE
EXCEPTION OF AN ISOLATED THUNDERSTORM FAR SOUTHERN PART OF ZONE 152
LATE TODAY. MIN RH LEVELS TODAY WILL BE THE LOWEST OF THE WEEK AND
BOTTOM OUT IN THE 15-25 PERCENT RANGE ACROSS LOWER ELEVATIONS WITH A
DECENT AFTERNOON BREEZE AGAIN THIS AFTERNOON. THE WIND WILL BE
STRONGEST IN THE GILA VALLEY ALTHOUGH A FEW MPH LESS THAN YESTERDAY.
MOISTURE WILL BEGIN TO INCREASE THURSDAY WITH ISOLATED SHOWERS AND
THUNDERSTORMS POSSIBLE...MAINLY SOUTHERN AREAS. THEN THE MOISTURE
AND THUNDERSTORMS CHANCES WILL INCREASE AND SPREAD THROUGHOUT
SOUTHEAST ARIZONA THROUGH THE WEEKEND INTO EARLY NEXT WEEK.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
DISCUSSION...FRANCIS
AVIATION/FIRE WEATHER...CERNIGLIA
AREA FORECAST DISCUSSION
NWS TAUNTON MA
725 PM EDT THU AUG 20 2015
.SYNOPSIS...
A SLOW MOVING FRONT WILL STALL OVER THE REGION FRIDAY INTO
SATURDAY BRINGING SCATTERED SHOWERS AND THUNDERSTORMS WITH
LOCALLY HEAVY RAINFALL. HUMID CONDITIONS ALONG WITH THE THREAT OF
SHOWERS AND THUNDERSTORMS WILL PERSIST THROUGH TUESDAY...THEN A
COLD FRONT WILL MOVE THROUGH BRINGING DRIER WEATHER FOR THE MIDDLE
OF NEXT WEEK. SUBTROPICAL LOW PRESSURE MOVING NORTHWEST FROM
BERMUDA WILL REMAIN WELL OUT TO SEA SUNDAY NIGHT INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
720 PM UPDATE...
STRATUS STARTING TO DEVELOP ALONG THE S COAST...AND PUSHING SOUTH
ALONG THE NORTH SHORE AS LOW LEVEL MOISTURE INCREASES FROM SE
FLOW. DEWPOINTS UPPER 60S AND LOWER 70S SO LOTS OF MOIST AIR AT
LOW LEVELS. STRATUS WILL CONTINUE TO DEVELOP AND GRADUALLY ADVECT
INLAND TONIGHT WITH AREAS OF FOG FORMING...ESPECIALLY ALONG THE
COAST. THE FOG MAY BE LOCALLY DENSE IN SPOTS. MIN TEMPS SHOULD BE
NEAR THE DEW POINTS...IN THE UPPER 60S AND LOWER 70S.
FRONT APPROACHING THROUGH NEW YORK OVERNIGHT WILL SPREAD SHOWERS
TOWARD OUR WESTERN AREAS WELL AFTER MIDNIGHT. WHILE MOST OF THE
DYNAMICS LIFT NORTH INTO CANADA...LOW LEVEL CONVERGENCE ALONG THE
FRONT WILL YIELD STRONG MID LEVEL OMEGA WHICH COMBINED WITH A FEW
HUNDRED JOULES OF SBCAPE WILL BE ENOUGH TO BRING SHOWERS/SCT
THUNDER INTO AREAS WEST OF WORCESTER AND WILLIMANTIC. HRRR AND
HIRES ARW/NMM ALL BRING A BAND OF HEAVY SHOWERS INTO W MA AND W
CT AROUND 09Z. PRECIPITABLE WATER VALUES CLIMB OVER 1.5 INCHES
ALL OF OUR AREA AND TO 2.0 INCHES IN WESTERN MASS AND CT.
MEANWHILE THE PROJECTED STORM MOTION WILL BE SOUTHWEST AT 5-10
KNOTS. MAIN THREAT VERY LATE TONIGHT WILL BE LOCALLY HEAVY
DOWNPOURS WHICH COULD CAUSE POOR DRAINAGE FLOODING.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
FRIDAY...
SHOWERS/TSTMS FROM TONIGHT WILL EXPAND ACROSS SOUTHERN NEW
ENGLAND FRIDAY MORNING. BY AFTERNOON MOST OF THE INSTABILITY WILL
BE FOUND IN EASTERN MASS/RI AND SUPPORTED BY A MOIST FLOW OFF THE
OCEAN. CONTINUED HIGH PRECIPITABLE WATER VALUES AND WEAK DYNAMICS.
THE PROBLEM OF THE DAY SHOULD REMAIN LOCALLY HEAVY DOWNPOURS WHILE
THE RISK OF SEVERE/DAMAGING WEATHER WILL BE LOW. SHOWER/TSTM
POTENTIAL LINGERS FRIDAY NIGHT BUT WITH LOWER CHANCE THAN DURING
THE DAY.
WE CONSIDERED ISSUING A FLOOD WATCH FOR FRIDAY. BUT ANTECEDENT
CONDITIONS ARE DRY AND MAY TAKE AS MUCH AS 3 INCHES FOR PROBLEMS
TO DEVELOP. WE EXPECT THE HEAVIEST RAIN AMOUNTS TO FALL JUST SHY
OF THAT. SO NO WATCH AT THIS TIME...BUT THE SITUATION WILL MERIT
CLOSE MONITORING.
WITH CLOUDS AND PCPN...EXPECT DAY/NIGHT TEMPERATURE CHANGES WILL BE
LIMITED. MAX TEMPS MID 70S TO LOWER 80S...AND FRI NIGHT MIN TEMPS
IN THE MID 60S TO AROUND 70.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
HIGHLIGHTS...
* WARM AND HUMID CONDITIONS ALONG WITH SCATTERED SHOWERS AND
THUNDERSTORMS PERSIST THROUGH TUE
* DRY WEATHER AND LESS HUMID CONDITIONS WILL FOLLOW FOR WED/THU
OVERVIEW...
MODELS IN DECENT AGREEMENT ON LARGE SCALE PATTERN THROUGH MUCH OF
NEXT WEEK FEATURING A BUILDING RIDGE ACROSS THE ROCKIES AND CENTRAL
PLAINS AND CLOSED LOW MOVING INTO SE CANADA WITH MEAN TROF
DEVELOPING ACROSS THE GT LAKES. WITH SUBTROPICAL AIRMASS IN PLACE
AND DEVELOPING MOIST EASTERLY FLOW FROM APPROACHING LOW PRES MOVING
NW FROM BERMUDA...UNSETTLED WEATHER EXPECTED THROUGH EARLY NEXT WEEK
WITH SCT SHOWERS AND T-STORMS AT TIMES. THIS LOW MAY DEVELOP
SUBTROPICAL OR TROPICAL CHARACTERISTICS BUT IS EXPECTED TO REMAIN
WELL OUT TO SEA LATE SUN INTO MON. APPROACHING MID LEVEL TROF WILL
BRING A COLD FRONT THROUGH THE REGION LATE TUE/TUE EVENING WHICH
WILL FINALLY PUSH THE HUMIDITY OUT TO SEA WITH DRIER AIRMASS MOVING
IN FOR WED/THU.
SATURDAY...
COLD FRONT WILL HAVE MOVED TO SE NEW COAST BY SAT MORNING...BUT
FRONT IS EXPECTED TO WEAKEN AND EVENTUALLY GET ABSORBED BY
DEVELOPING LOW LEVEL EASTERLY FLOW. MODELS SHOW AXIS OF INSTABILITY
WITH CAPES 1000-1500 J/KG DEVELOPING ACROSS CENTRAL AND E NEW ENG
AND WITH LEFTOVER CONVERGENCE FROM SFC BOUNDARY...EXPECT SCT SHOWERS
AND T-STORMS TO DEVELOP. ACTIVITY SHOULD BE MAINLY CONFINED E OF
THE CT VALLEY AS DRIER AIR AND MUCH LOWER KI ADVECT INTO W NEW ENG
AND THE CT VALLEY WHICH SHOULD SUPPRESS CONVECTION IN THIS AREA. 0-
6KM SHEAR 20-25 KT IS A BIT LESS THAN WE WOULD LIKE TO SEE FOR
SEVERE WEATHER...BUT GIVEN CAPES GREATER THAN 1000 J/KG CANT RULE
OUT A FEW STRONG TO SEVERE STORMS. HEAVY RAINFALL WILL BE THE
PRIMARY THREAT GIVEN PWATS 1.75 TO 2 INCHES. LOTS OF CLOUDS
EXPECTED SAT WHICH WILL KEEP TEMPS IN THE UPPER 70S TO LOWER
80S...BUT QUITE HUMID IN THE COASTAL PLAIN WITH DEWPOINTS NEAR 70.
LESS HUMID CONDITIONS IN W NEW ENG.
SUNDAY AND MONDAY...
GFS IS A WESTERN OUTLIER WITH LOW PRES MOVING NW FROM BERMUDA. THIS
SYSTEM MAY BECOME SUBTROPICAL OR TROPICAL BUT IS EXPECTED TO REMAIN
WELL OUT TO SEA. SUBTROPICAL MOISTURE AHEAD OF THIS SYSTEM WILL BE
ADVECTED INTO THE REGION RESULTING IN QUITE HUMID CONDITIONS AND
DEWPOINTS NEAR 70. THIS WILL LEAD TO MODEST INSTABILITY DEVELOPING
AND A CONTINUED THREAT OF SCT SHOWERS/T-STORMS. HEAVY RAINFALL WILL
BE PRIMARY THREAT IN HIGH PWAT AIRMASS. SEVERE THREAT IS LIMITED
GIVEN RELATIVELY WEAK SHEAR BUT CAPES NEAR OR ABOVE 1000 J/KG SO
CANT RULE OUT A FEW STRONG STORMS.
TUESDAY...
THIS MAY BE THE BEST CHANCE FOR ORGANIZED SEVERE WEATHER AS MID
LEVEL TROF AND COLD FRONT APPROACHES FROM THE W. CAPES FORECAST TO
BE GREATER THAN 1000 J/KG. INCREASING MID LEVEL WINDS MOVING IN FROM
THE WEST RESULTS IN 0-6 KM SHEAR INCREASING TO 30-40 KT SO POTENTIAL
EXISTS FOR STRONG TO SEVERE STORMS. STILL A DAY 5 FORECAST SO WILL
HAVE TO CONTINUE TO MONITOR.
WEDNESDAY AND THURSDAY...
COLD FRONT MOVES OFFSHORE WITH HIGH PRES BUILDING IN FROM THE
WEST WILL LEAD TO DRY AND LESS HUMID CONDITIONS.
&&
.AVIATION /23Z THURSDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
TONIGHT...MODERATE CONFIDENCE. IFR STRATUS DEVELOPING ALONG THE S
COAST AND NORTH SHORE. EXPECT STRATUS TO CONTINUE TO DEVELOP AND
GRADUALLY SPREAD INLAND WITH IFR/LIFR DEVELOPING ALONG WITH AREAS
OF FOG. LOCALLY DENSE FOG IS POSSIBLE...MAINLY ALONG THE COAST.
SHOWERS DEVELOPING IN THE BERKSHIRES AND CONNECTICUT RIVER VALLEY
LATE AT NIGHT...TOWARD 09Z. LIGHT SOUTHEAST FLOW.
FRIDAY...MODERATE CONFIDENCE. LOW CLOUDS AND FOG SHOULD LIFT TO
SOME DEGREE BY LATE MORNING...BUT MVFR CONDITIONS MAY PERSIST
INTO THE AFTERNOON. IN ADDITION...SHOWERS/SCATTERED THUNDERSTORMS
WITH LOCALLY HEAVY RAINFALL WILL BE POSSIBLE. CIGS MAY IMPROVE TO
VFR BUT VSBYS IN ANY SHOWERS/DOWNPOURS WILL BE MVFR AND LOCALLY
IFR. LIGHT SOUTH TO SOUTHWEST FLOW.
FRIDAY NIGHT...MODERATE CONFIDENCE. MVFR CIGS/VSBYS IN ANY
SHOWERS/TSTMS WITH IFR POSSIBLE IN LOCALLY HEAVY DOWNPOURS.
KBOS TERMINAL...MODERATE CONFIDENCE. EXPECT STRATUS TO
DEVELOP/MOVE INTO LOGAN THIS EVENING. IFR FOG POSSIBLE LATER
TONIGHT.
KBDL TERMINAL...MODERATE TO HIGH CONFIDENCE. VFR.
OUTLOOK /SATURDAY THROUGH TUESDAY/...
SATURDAY...MODERATE CONFIDENCE. MVFR/IFR STRATUS AND PATCHY FOG E
NEW ENG IN THE MORNING GRADUALLY IMPROVING. MOSTLY VFR W. HOWEVER...
SCT SHOWERS/T-STORMS WITH LOCALLY HEAVY RAIN EXPECTED E OF CT VALLEY
WITH BRIEF IFR POSSIBLE.
SUNDAY THROUGH TUESDAY...MODERATE CONFIDENCE. MVFR/IFR CONDITIONS
POSSIBLE AT TIMES IN NIGHTTIME STRATUS AND FOG ALONG WITH SCT
SHOWERS/T-STORMS.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /TODAY THROUGH FRIDAY/...HIGH CONFIDENCE.
TONIGHT...HIGH PRESSURE OFFSHORE WITH A WEAK PRESSURE GRADIENT.
EXPECT LIGHT SOUTHEAST FLOW WITH WINDS/SEAS BELOW SMALL CRAFT
ADVISORY THRESHOLDS. FOG/LOW CLOUDS LINGERS ALONG CAPE ANN.
ADDITIONAL FOG/LOW CLOUDS WILL REDEVELOP ALONG THE REMAINDER OF
THE WATERS...BRINGING POOR VISIBILITY ESPECIALLY AFTER MIDNIGHT.
FRIDAY AND FRIDAY NIGHT...
WINDS AND SEAS REMAIN BELOW SMALL CRAFT THRESHOLDS. FOG/LOW CLOUDS
WILL LIFT AND THIN...BUT SHOWERS/TSTMS AHEAD OF A WEAK COLD FRONT
WILL MOVE OVER THE WATERS BY FRIDAY AFTERNOON AND FRIDAY NIGHT.
OUTLOOK...SATURDAY THROUGH TUESDAY...
SATURDAY...HIGH CONFIDENCE. LIGHT WINDS AND SEAS. POOR VSBYS IN
MORNING FOG...IMPROVING IN THE AFTERNOON BUT MAY BE BRIEFLY REDUCED
IN ANY SHOWERS AND T-STORMS.
SUNDAY THROUGH TUESDAY...MODERATE CONFIDENCE. STRONGER WINDS FROM
APPROACHING LOW PRES SHOULD REMAIN OFFSHORE LATE SUN INTO MON.
EASTERLY WINDS MOSTLY LESS THAN 20 KT...WITH SW WINDS DEVELOPING
TUE. BUILDING SWELL MAY LEAD TO 5+ FT SEAS OVER OUTER WATERS LATE
SUN INTO MON. VSBYS REDUCED AT TIMES IN FOG. A FEW SHOWERS AND T-
STORMS POSSIBLE.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...WTB/KJC
NEAR TERM...WTB/KJC
SHORT TERM...WTB
LONG TERM...KJC
AVIATION...WTB/KJC
MARINE...WTB/KJC
AREA FORECAST DISCUSSION
NWS MIAMI FL
758 PM EDT THU AUG 20 2015
.AVIATION...
SLIGHTLY WEAKER WIND FLOW WILL BE THE ONLY CHANGE TO THE CURRENT
REGIME ON FRIDAY. IN ADDITION, A WEAKER OR NO SUBSIDENCE CAP MAY
LEAD TO MORE NUMEROUS STORMS, SOME OF WHICH MAY BE CLOSER TO THE
EAST COAST TAF SITES. HOWEVER, WITH FOCUS STILL OVER THE INTERIOR,
AND NOT A GREAT DEAL OF CONFIDENCE, WILL NOT ADD VCTS AT THIS
TIME TO THE EAST COAST. A BRIEF MVFR CIG CAN OCCUR ONCE AGAIN NEAR
DAWN UNDER EAST FLOW.
&&
.PREV DISCUSSION... /ISSUED 747 PM EDT THU AUG 20 2015/
UPDATE...
MAKING SOME MINOR ADJUSTMENTS TO THE EVENING UPDATES BASED ON
LATEST TRENDS. EARLY EVENING ACTIVITY SHOULD DIMINISH BY 02Z WITH THE
GRADIENT FLOW WEAKENING CONSIDERABLY SO THE CHANCES FOR ATLANTIC
DEVELOPMENT LATER TONIGHT MOVING ONSHORE SEEM RATHER REMOTE AT
THIS TIME. NEITHER THE HRRR NOR THE LOCALLY RUN WRF SHOW THIS
OCCURRING SO AM REMOVING MENTION OF THUNDER ALL AREAS WITH THE
EXCEPTION OF THE THE OFFSHORE WATERS FOR LATER TONIGHT.
KOB
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 78 92 77 92 / 10 40 20 40
FORT LAUDERDALE 79 91 79 92 / 10 40 20 50
MIAMI 79 92 79 94 / 10 40 30 50
NAPLES 78 90 78 91 / 10 40 30 50
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...30/KOB
LONG TERM....30/KOB
AVIATION...21/KM
AREA FORECAST DISCUSSION
NWS MIAMI FL
747 PM EDT THU AUG 20 2015
.UPDATE...
MAKING SOME MINOR ADJUSTMENTS TO THE EVENING UPDATES BASED ON
LATEST TRENDS. EARLY EVENING ACTIVITY SHOULD DIMINISH BY 02Z WITH THE
GRADIENT FLOW WEAKENING CONSIDERABLY SO THE CHANCES FOR ATLANTIC
DEVELOPMENT LATER TONIGHT MOVING ONSHORE SEEM RATHER REMOTE AT
THIS TIME. NEITHER THE HRRR NOR THE LOCALLY RUN WRF SHOW THIS
OCCURRING SO AM REMOVING MENTION OF THUNDER ALL AREAS WITH THE
EXCEPTION OF THE THE OFFSHORE WATERS FOR LATER TONIGHT.
KOB
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
230 PM EDT WED AUG 19 2015
.PREV DISCUSSION... /ISSUED 1113 AM EDT WED AUG 19 2015/
.UPDATE...
MAIN ADJUSTMENTS IN THE NEAR TERM WERE TO LOWER POP TRENDS THROUGH
MIDDAY AND FOCUS BEST CHANCE FOR SHOWERS AND STORMS IN THE
AFTERNOON/EVENING PER THE NAM 305 THETA UPGLIDE ZONES AND THE
HRRR AS THIS HI-RES SOLUTION SEEMS TO BE THE ONLY ONE LATCHING ON
TO THE LACK OF COVERAGE OBSERVED THUS FAR. STILL VERY TROPICAL
AIRMASS WITH 1.9 INCH PWAT OFF THIS MORNING SOUNDING AND JUST
OVER 2.0 INCH FOR BMX SO CONTINUING THE FLOODING THREAT AND
STRONG TO BRIEFLY SEVERE POTENTIAL WITH AFTERNOON
DESTABILIZATION.
THE BIG PLAYER FOR THIS EVENING AND OVERNIGHT WILL BE THE
EVOLUTION OF A LARGE CONVECTIVE COMPLEX CURRENTLY UPSTREAM ACROSS
LOUISIANA. THE HRRR ALSO HAS THE MCS/MCV BRINGING AT LEAST ANOTHER
ROUND OF WIDESPREAD SHOWERS BY 02-06Z TONIGHT THOUGH SOME
UNCERTAINTY WITH INTENSITY OF CONVECTION. WILL BE MONITORING THIS
FOR AFTERNOON FCST ISSUANCE AND MAY NEED TO RAISE OVERNIGHT POPS
ACCORDINGLY. PREVIOUS DISCUSSION FOLLOWS...
BAKER
&&
PREV DISCUSSION... /ISSUED 731 AM EDT WED AUG 19 2015/
PREV DISCUSSION... /ISSUED 430 AM EDT WED AUG 19 2015/
.SHORT TERM /TODAY THROUGH THURSDAY/...
MODELS IN GOOD AGREEMENT THROUGH THE SHORT TERM WITH A VERY GOOD
GULF CONNECTION SPREADING DEEP MOISTURE OVER THE CWA. THIS WILL
CONTINUE INTO WEDNESDAY KEEP SCATTERED TO WIDESPREAD SHOWERS AND
TSTORMS OVER THE CWA. THE BEST CHANCES WILL BE ACROSS NORTH GEORGIA
AND MAINLY DURING THE AFTERNOON AND EVENING HOURS. ALTHOUGH THUNDER
WILL BE MINIMAL EARLY THIS MORNING AND ALSO WEDNESDAY MORNING...
EXPECT THUNDER TO BECOME MORE NUMEROUS WITH DAYTIME HEATING THIS
AFTERNOON AND INTO THE EARLY EVENING HOURS. ALTHOUGH THE GREATEST
INSTABILITY WILL BE ACROSS NORTH GA...AN ISOLATED STRONG TO SEVERE
STORM WILL BE POSSIBLE JUST ABOUT ANYWHERE THIS AFTERNOON AND
EVENING WITH THE MAIN THREAT BEING STRONG WINDS. TEMPERATURES
THROUGH WEDNESDAY WILL BE PRETTY CLOSE TO PERSISTENCE DUE TO
CLOUDS AND PRECIP...AND THE MODELS HAVE A GOOD HANDLE ON THIS.
17
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
PATTERN STILL ON TRACK TO SHIFT TO WEAK W-E ZONAL FLOW ACROSS THE
SE CONUS LATE THIS WEEK THEN GO INTO WEAK NW FLOW ON THIS WEEKEND.
SOME INDICATIONS THAT A WEAK SHORTWAVE WILL AFFECT AREA ON SUNDAY BY
00Z MED RANGE MODELS. HAVE BUMPED POPS UP A LITTLE FROM BLEND. CHC
FOR FROPA NOW LOOKING LESS LIKELY EARLY NEXT WEEK SO IN THE SOUP
WE STAY. DAYTIME TEMPS SHOULD BE AT OR SLIGHTLY BELOW NORMAL SO
SOME CONSOLATION.
ATLANTIC BASIN HAS ITS FOURTH NAMED STORM...TS DANNY...AND COULD
AFFECT INTERESTS IN THE VIRGIN ISLANDS AND PERHAPS PUERTO RICO
NEXT WEEK AS DANNY MOVES SLOWLY WEST. NO OTHER FEATURES OF NOTE
THRU TUES.
SNELSON
17
.AVIATION...
18Z UPDATE...
INITIAL CIGS OF HIGH END MVFR TO LOW END VFR IN 2500-3500 FT
RANGE WITH SCATTERED SHOWERS AND TSRA POTENTIAL UP UNTIL 00Z OR
SLIGHTLY AFTER WITH LINGERING -SHRA POSSIBLY THRU 04Z FROM A
DISTURBANCE TRACKING ALONG THE TROPICAL SW FLOW. CIGS LOOK TO
LOWER AGAIN TO IFR SIMILAR TO PREVIOUS MORNINGS FOR 09-14Z WITH
GRADUAL IMPROVEMENT AND AGAIN CHANCE FOR PRECIP AND -TSRA
RETURNING NEAR 18Z TOMORROW. WINDS SHOULD STAY MAINLY SW TO WEST
AT 5-8 KTS WITH LIGHT TO CALM OVERNIGHT. EXPECT REDUCED VSBYS WITH
ANY TSRA IN MVFR/IFR RANGE.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM ON PRECIP TIMING AND OVERNIGHT CIGS.
HIGH ON ALL ELSE.
BAKER
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 84 71 89 72 / 70 50 60 30
ATLANTA 86 71 88 72 / 70 60 60 30
BLAIRSVILLE 79 70 82 65 / 70 70 60 30
CARTERSVILLE 86 72 86 69 / 70 60 60 30
COLUMBUS 87 74 88 74 / 70 60 60 30
GAINESVILLE 82 71 84 71 / 70 60 60 30
MACON 89 73 91 73 / 60 40 50 30
ROME 85 71 85 69 / 70 70 60 30
PEACHTREE CITY 87 71 90 71 / 70 60 60 30
VIDALIA 91 73 94 75 / 50 40 50 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...17/BAKER
LONG TERM....SNELSON
AVIATION...BAKER
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
1113 AM EDT WED AUG 19 2015
.UPDATE...
MAIN ADJUSTMENTS IN THE NEAR TERM WERE TO LOWER POP TRENDS THROUGH
MIDDAY AND FOCUS BEST CHANCE FOR SHOWERS AND STORMS IN THE
AFTERNOON/EVENING PER THE NAM 305 THETA UPGLIDE ZONES AND THE
HRRR AS THIS HI-RES SOLUTION SEEMS TO BE THE ONLY ONE LATCHING ON
TO THE LACK OF COVERAGE OBSERVED THUS FAR. STILL VERY TROPICAL
AIRMASS WITH 1.9 INCH PWAT OFF THIS MORNING SOUNDING AND JUST
OVER 2.0 INCH FOR BMX SO CONTINUING THE FLOODING THREAT AND
STRONG TO BRIEFLY SEVERE POTENTIAL WITH AFTERNOON
DESTABILIZATION.
THE BIG PLAYER FOR THIS EVENING AND OVERNIGHT WILL BE THE
EVOLUTION OF A LARGE CONVECTIVE COMPLEX CURRENTLY UPSTREAM ACROSS
LOUISIANA. THE HRRR ALSO HAS THE MCS/MCV BRINGING AT LEAST ANOTHER
ROUND OF WIDESPREAD SHOWERS BY 02-06Z TONIGHT THOUGH SOME
UNCERTAINTY WITH INTENSITY OF CONVECTION. WILL BE MONITORING THIS
FOR AFTERNOON FCST ISSUANCE AND MAY NEED TO RAISE OVERNIGHT POPS
ACCORDINGLY. PREVIOUS DISCUSSION FOLLOWS...
BAKER
&&
.PREV DISCUSSION... /ISSUED 731 AM EDT WED AUG 19 2015/
PREV DISCUSSION... /ISSUED 430 AM EDT WED AUG 19 2015/
.SHORT TERM /TODAY THROUGH THURSDAY/...
MODELS IN GOOD AGREEMENT THROUGH THE SHORT TERM WITH A VERY GOOD
GULF CONNECTION SPREADING DEEP MOISTURE OVER THE CWA. THIS WILL
CONTINUE INTO WEDNESDAY KEEP SCATTERED TO WIDESPREAD SHOWERS AND
TSTORMS OVER THE CWA. THE BEST CHANCES WILL BE ACROSS NORTH GEORGIA
AND MAINLY DURING THE AFTERNOON AND EVENING HOURS. ALTHOUGH THUNDER
WILL BE MINIMAL EARLY THIS MORNING AND ALSO WEDNESDAY MORNING...
EXPECT THUNDER TO BECOME MORE NUMEROUS WITH DAYTIME HEATING THIS
AFTERNOON AND INTO THE EARLY EVENING HOURS. ALTHOUGH THE GREATEST
INSTABILITY WILL BE ACROSS NORTH GA...AN ISOLATED STRONG TO SEVERE
STORM WILL BE POSSIBLE JUST ABOUT ANYWHERE THIS AFTERNOON AND
EVENING WITH THE MAIN THREAT BEING STRONG WINDS. TEMPERATURES
THROUGH WEDNESDAY WILL BE PRETTY CLOSE TO PERSISTENCE DUE TO
CLOUDS AND PRECIP...AND THE MODELS HAVE A GOOD HANDLE ON THIS.
17
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
PATTERN STILL ON TRACK TO SHIFT TO WEAK W-E ZONAL FLOW ACROSS THE
SE CONUS LATE THIS WEEK THEN GO INTO WEAK NW FLOW ON THIS WEEKEND.
SOME INDICATIONS THAT A WEAK SHORTWAVE WILL AFFECT AREA ON SUNDAY BY
00Z MED RANGE MODELS. HAVE BUMPED POPS UP A LITTLE FROM BLEND. CHC
FOR FROPA NOW LOOKING LESS LIKELY EARLY NEXT WEEK SO IN THE SOUP
WE STAY. DAYTIME TEMPS SHOULD BE AT OR SLIGHTLY BELOW NORMAL SO
SOME CONSOLATION.
ATLANTIC BASIN HAS ITS FOURTH NAMED STORM...TS DANNY...AND COULD
AFFECT INTERESTS IN THE VIRGIN ISLANDS AND PERHAPS PUERTO RICO
NEXT WEEK AS DANNY MOVES SLOWLY WEST. NO OTHER FEATURES OF NOTE
THRU TUES.
SNELSON
17
&&
.AVIATION...
12Z UPDATE...
A MIX OF IFR/MVFR WILL CONTINUE THROUGH MID MORNING THEN RISE TO
VFR BY 16Z AND REMAIN VFR UNTIL EVENING. SCATTERED LIGHT SHOWERS
ACROSS THE FORECAST AREA WILL BECOME MORE NUMEROUS TODAY...THEN
DIMINISH AFTER SUNSET. WINDS WILL REMAIN SOUTHWEST LESS THAN 10
KTS.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM ON CIGS THIS MORNING
MEDIUM ON TIMING OF SHRA/TSRA
HIGH ON REMAINING ELEMENTS
17
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 84 71 89 72 / 70 50 60 30
ATLANTA 86 71 88 72 / 70 60 60 30
BLAIRSVILLE 79 70 82 65 / 70 70 60 30
CARTERSVILLE 86 72 86 69 / 70 60 60 30
COLUMBUS 87 74 88 74 / 70 60 60 30
GAINESVILLE 82 71 84 71 / 70 60 60 30
MACON 89 73 91 73 / 60 40 50 30
ROME 85 71 85 69 / 70 70 60 30
PEACHTREE CITY 87 71 90 71 / 70 60 60 30
VIDALIA 91 73 94 75 / 50 40 50 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...17/BAKER
LONG TERM....SNELSON
AVIATION...17
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
754 AM EDT WED AUG 19 2015
.SYNOPSIS...
DEEP MOISTURE WILL REMAIN ACROSS THE AREA THE AREA TODAY INTO
THURSDAY WITH SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS.
A WEAK FRONT WILL APPROACH THE AREA ON THURSDAY. THE FRONT WILL
DISSIPATE NEAR THE AREA SATURDAY...WITH HIGH PRESSURE RETURNING
FOR SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
OUR REGION WILL RESIDE ALONG THE NORTHERN PERIPHERY OF THE UPPER
RIDGE CENTERED ACROSS FLORIDA INTO THE GULF OF MEXICO. COULD SEE
WEAK SHORT WAVES CROSS THE AREA IN SOUTHWEST FLOW ALOFT. THE AIR
MASS WILL REMAIN QUITE MOIST WITH PWAT VALUES AT OR ABOVE 2 INCHES.
GIVEN POSSIBLE SHORT WAVES...WEAK TO MODERATE INSTABILITY...AMPLE
MOISTURE AND DAYTIME HEATING...WE EXPECT ANOTHER DAY OF SCATTERED
TO NUMEROUS SHOWERS AND THUNDERSTORMS. THE HRRR MODEL HAS ONE AREA
OF CONVECTION EXITING TO THE NORTHEAST EARLY THIS MORNING...THEN
NEXT ROUND MOVING INTO THE REGION FROM THE WEST EARLY THIS
AFTERNOON. HEAVY DOWNPOURS ONCE AGAIN POSSIBLE. SHOWERS AND
THUNDERSTORMS EXPECTED TO LINGER INTO TONIGHT AS A PRE-
FRONTAL TROUGH DEVELOP ACROSS THE CAROLINAS.
KEPT TEMPERATURES CLOSE TO GUIDANCE CONSENSUS WITH HIGHS IN THE
UPPER 80S TO LOWER 90S AND LOWS IN THE LOW TO MID 70S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
OUR WET PATTERN WILL HOLD THURSDAY INTO FRIDAY AS A WEAK COLD
FRONT MOVES INTO THE AREA. PRECIPITABLE WATER WILL REMAIN HIGH
WITH VALUES MAINLY AROUND 2 INCHES. HEAVY DOWNPOURS MAY OCCUR WITH
SOME OF THE THUNDERSTORMS. THE FRONT MAY SLIDE JUST SOUTH AND EAST
OF THE MIDLANDS AND CSRA FRIDAY. HAVE FOLLOWED GUIDANCE TRENDS
WITH HIGH CHANCE POPS FOR THURSDAY THEN LOW CHANCE FOR FRIDAY.
USED THE GUIDANCE CONSENSUS FOR THE HIGH TEMPERATURE FORECAST.
USED THE WARMER LOW TEMPERATURE GUIDANCE BECAUSE OF THE HIGH
MOISTURE.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
THE GFS AND ECMWF DISPLAY A DIFFUSE FRONT STALLED NEAR THE
FORECAST AREA EARLY IN THE MEDIUM-RANGE PERIOD. THE MODELS DISPLAY
ANOTHER FRONT LATE IN THE PERIOD. THE MODELS HAVE UPPER RIDGING
SATURDAY...WITH TROUGHING DURING THE REST OF THE PERIOD. THE
PATTERN SUPPORTS A CONTINUED CHANCE OF SHOWERS AND THUNDERSTORMS.
THE GFS ENSEMBLE MEAN PLUS GFS...ECMWF...AND EKD MOS SUPPORT POPS
OF MAINLY 20 TO 30 PERCENT. ABOVE NORMAL HIGH TEMPERATURES SHOULD
BE ASSOCIATED WITH THE UPPER RIDGING EARLY IN THE PERIOD. THE REST
OF THE PERIOD WILL LIKELY HAVE NEAR NORMAL TEMPERATURES.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS EXPECTED OUTSIDE OF FOG/STRATUS THIS MORNING AND
SHOWERS/THUNDERSTORMS THROUGH TONIGHT.
RESTRICTIONS IN FOG AND STRATUS HAVE DEVELOPED THIS MORNING IN THE
CSRA BUT MIXING SHOULD ALLOW A RETURN TO VFR BY 14Z. DEEP MOISTURE
AND HEATING WILL PROMOTE THE DEVELOPMENT OF SHOWERS ONCE AGAIN
THIS AFTERNOON...WHICH MAY BRING BRIEF RESTRICTIONS TO VISIBILITY
AT ALL TAF SITES. WINDS WILL BE OUT OF THE SOUTHWEST TODAY AT 5 TO
10 KNOTS.
EXTENDED AVIATION OUTLOOK...A MOIST SOUTHERLY FLOW WILL CONTINUE
THROUGH THURSDAY. THERE WILL BE SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS. STRATUS AND FOG MAY OCCUR DURING THE EARLY MORNING
HOURS.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
418 AM EDT WED AUG 19 2015
.SYNOPSIS...
DEEP MOISTURE WILL REMAIN ACROSS THE AREA THE AREA TODAY INTO
THURSDAY WITH SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS.
A WEAK FRONT WILL APPROACH THE AREA ON THURSDAY. THE FRONT WILL
DISSIPATE NEAR THE AREA SATURDAY...WITH HIGH PRESSURE RETURNING
FOR SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
OUR REGION WILL RESIDE ALONG THE NORTHERN PERIPHERY OF THE UPPER
RIDGE CENTERED ACROSS FLORIDA INTO THE GULF OF MEXICO. COULD SEE
WEAK SHORT WAVES CROSS THE AREA IN SOUTHWEST FLOW ALOFT. THE AIR
MASS WILL REMAIN QUITE MOIST WITH PWAT VALUES AT OR ABOVE 2 INCHES.
GIVEN POSSIBLE SHORT WAVES...WEAK TO MODERATE INSTABILITY...AMPLE
MOISTURE AND DAYTIME HEATING...WE EXPECT ANOTHER DAY OF SCATTERED
TO NUMEROUS SHOWERS AND THUNDERSTORMS. THE HRRR MODEL HAS ONE AREA
OF CONVECTION EXITING TO THE NORTHEAST EARLY THIS MORNING...THEN
NEXT ROUND MOVING INTO THE REGION FROM THE WEST EARLY THIS
AFTERNOON. HEAVY DOWNPOURS ONCE AGAIN POSSIBLE. SHOWERS AND
THUNDERSTORMS EXPECTED TO LINGER INTO TONIGHT AS A PRE-
FRONTAL TROUGH DEVELOP ACROSS THE CAROLINAS.
KEPT TEMPERATURES CLOSE TO GUIDANCE CONSENSUS WITH HIGHS IN THE
UPPER 80S TO LOWER 90S AND LOWS IN THE LOW TO MID 70S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
OUR WET PATTERN WILL HOLD THURSDAY INTO FRIDAY AS A WEAK COLD
FRONT MOVES INTO THE AREA. PRECIPITABLE WATER WILL REMAIN HIGH
WITH VALUES MAINLY AROUND 2 INCHES. HEAVY DOWNPOURS MAY OCCUR WITH
SOME OF THE THUNDERSTORMS. THE FRONT MAY SLIDE JUST SOUTH AND EAST
OF THE MIDLANDS AND CSRA FRIDAY. HAVE FOLLOWED GUIDANCE TRENDS
WITH HIGH CHANCE POPS FOR THURSDAY THEN LOW CHANCE FOR FRIDAY.
USED THE GUIDANCE CONSENSUS FOR THE HIGH TEMPERATURE FORECAST.
USED THE WARMER LOW TEMPERATURE GUIDANCE BECAUSE OF THE HIGH
MOISTURE.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
THE GFS AND ECMWF DISPLAY A DIFFUSE FRONT STALLED NEAR THE
FORECAST AREA EARLY IN THE MEDIUM-RANGE PERIOD. THE MODELS DISPLAY
ANOTHER FRONT LATE IN THE PERIOD. THE MODELS HAVE UPPER RIDGING
SATURDAY...WITH TROUGHING DURING THE REST OF THE PERIOD. THE
PATTERN SUPPORTS A CONTINUED CHANCE OF SHOWERS AND THUNDERSTORMS.
THE GFS ENSEMBLE MEAN PLUS GFS...ECMWF...AND EKD MOS SUPPORT POPS
OF MAINLY 20 TO 30 PERCENT. ABOVE NORMAL HIGH TEMPERATURES SHOULD
BE ASSOCIATED WITH THE UPPER RIDGING EARLY IN THE PERIOD. THE REST
OF THE PERIOD WILL LIKELY HAVE NEAR NORMAL TEMPERATURES.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
S/W MOVING ACROSS THE AREA OVERNIGHT. AHEAD OF THIS FEATURE A
LINE OF SHOWERS AND SCATTERED THUNDERSTORMS CONTINUES TO MOVE
EAST- NORTHEAST ACROSS THE EASTERN PORTION OF THE CWA. THE
STRONGEST STORMS AREA ACROSS CHESTERFIELD COUNTY AND MOVING INTO
THE PEE DEE/S CNTRL NC.
ALL TAF SITES CURRENTLY REPORTING VFR CONDITIONS. HAVE CONTINUED
THROUGH 07Z THE MENTION OF SHOWERS AT OGB...OTHERWISE EXPECT MAINLY
DRY CONDITIONS FOR THE REMAINDER OF THE NIGHT. WINDS GENERALLY
VARIABLE DUE TO BOUNDARIES ACROSS THE AREA. MODELS DO HINT AT SOME
ENHANCED MOISTURE IN LOW-LEVELS LATE TONIGHT...BUT DO NOT EXPECT ANY
WIDESPREAD FOG DUE TO AN OVERNIGHT LOW-LEVEL JET AND EXPECTED
CLOUDS. CONFIDENCE REMAINS LOW...BUT DID MENTION MVFR BR AT AGS/OGB
TOWARDS MORNING. ADDITIONAL SHOWERS SHOULD ONCE AGAIN FORM THIS
AFTERNOON...WHICH MAY BRING BRIEF RESTRICTIONS TO VISIBILITY AT ALL
TAF SITES.
EXTENDED AVIATION OUTLOOK...A MOIST SOUTHERLY FLOW WILL CONTINUE
THROUGH THURSDAY. THERE WILL BE SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS. STRATUS AND FOG MAY OCCUR DURING THE EARLY MORNING
HOURS.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
109 AM EDT WED AUG 19 2015
.PREV DISCUSSION... /ISSUED 1020 PM EDT TUE AUG 18 2015/
UPDATE...
THUNDER KEEPS DIMINISHING ACROSS THE CWFA THIS EVENING. HAVE
TWEAKED POPS ACCORDING TO THE LATEST RADAR TRENDS. THE HRRR KEEPS
ONLY A FEW SHOWERS AROUND OVERNIGHT...SO HAVE LOWERED POPS A BIT.
MODELS ARE A LITTLE SLOWER STARTING THE PRECIP TOMORROW...SO
DELAYED THE ONSET OF THE LIKELY POPS.
PREV DISCUSSION... /ISSUED 343 PM EDT TUE AUG 18 2015/
SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
NO MAJOR CHANGES IN THE OVERALL WET PATTERN IS EXPECTED AS AN ACTIVE
SOUTHWEST FLOW ALOFT CONTINUES TO INTERACT WITH VERY MOIST AND
MODERATELY UNSTABLE ENVIRONMENT TO PRODUCE SCATTERED TO NUMEROUS
SHOWERS AND THUNDERSTORMS... MAINLY DURING DAYTIME HEATING BETWEEN
NOON AND 10 PM... WITH MAINLY ISOLATED TO SCATTERED SHOWERS
LINGERING OVERNIGHT.
ALTHOUGH MOST STORMS WILL REMAIN WELL UNDER SEVERE LIMITS... AN
ISOLATED STRONG TO SEVERE STORM CANNOT BE RULED OUT DURING THE LATE
AFTERNOON AND EARLY EVENING HOURS TODAY... AND AGAIN ON WEDNESDAY
AS CAPE VALUES CLIMB INTO THE 2500-3000 J/KG RANGE.
THE GREATER CONVECTIVE CONCERN IS THE POTENTIAL FOR BRIEF FLOODING
AS ENTRENCHED DEEP TROPICAL MOISTURE SUPPORTS LOCALLY HEAVY
DOWNPOURS... EVEN FROM SHOWERS... THAT CAN QUICKLY DUMP 1-3 INCHES
IN A SHORT PERIOD OF TIME. WILL NEED TO MONITOR ANY FLASHY... FLOOD
PRONE CREEKS CLOSELY OVER THE NEXT COUPLE OF DAYS OR MORE.
OTHERWISE... WILL LEAN TOWARD PERSISTENCE FOR TEMPS AS AMPLE LOWS
CLOUDS TONIGHT AND WEDNESDAY NIGHT HOLD LOWS IN THE 70S... AND
WIDESPREAD CONVECTION HELP HOLD HIGHS ON WEDNESDAY MOSTLY IN THE
80S... EXCEPT SOME LOWER 90S IN THE FAR SOUTHERN REACHES.
39
LONG TERM /THURSDAY THROUGH TUESDAY/...
NO MAJOR CHANGES MADE TO THE FORECAST PERIOD AS THE LONG TERM
SOLUTIONS IN DECENT AGREEMENT EXCEPT FOR LATE IN THE PERIOD. GFS
HAS LOWER AMPLITUDE UPPER TROUGH DYNAMICS BY EARLY NEXT WEEK AND
THUS STRUGGLES TO PUSH A FRONT THROUGH BUT HAVE LEANED MORE TOWARD
PREVIOUS FORECAST AND EARLIER ECMWF TO KEEP CONSISTENCY. OTHERWISE
HAVE REFRESHED OTHER FIELDS WITH LATEST BLEND. PREVIOUS DISCUSSION
FOLLOWS...
BAKER
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
PATTERN IN LONG TERM PERIOD TRANSITIONS FROM HIGH AMPLITUDE TROUGH
ALONG THE MS RIVER VALLEY STATES ON WED TO ZONAL FLOW THIS WEEKEND
AND FINALLY WEAK NW FLOW/UPR RIDGE TO THE WEST WITH A HINT OF A
MDT FROPA ON MONDAY. WITH THE FIRST TWO PATTERNS...SE CONUS SHOULD
REMAIN IN MOIST PATTERN WITH DEEP MOISTURE THRU THE WEEKEND. NO
ONE DAY SEEMS TO STAND OUT WITH PRECIP CHCS NOR DO ANY DAYS SEEM
TO HAVE CHC FOR SVR OR EVEN STRONG DEEP CONVECTION. MED RANGE
MODELS IN GOOD AGREEMENT. WPC PREFERRING BLEND OF ALL 00Z
OPERATIONAL MODELS FOR FEATURES AFFECTING CWA THRU DAY 7.
TROPICAL ACTIVITY REMAINS SUBDUED. COLD CORE UPPER LOW OFF
CAROLINA COAST...WHICH HAS PLAYED A ROLE IN CREATING STAGNANT
PATTERN OF LATE AND MAY BECOME TROPICAL IN NATURE...SHOULD GET
PICKED UP BY UPPER TROUGH THIS WEEKEND AND LIFT AWAY FROM EAST
COAST. LOW LATITUDE DISTURBANCE AT 35W LONGITUDE THAT TPC IS
TRACKING COULD DEVELOP INTO A NAMED STORM BUT PROGGED TO REMAIN ON
WESTERLY COURSE WITH MEAGER INTENSITY BY ECMWF AND GFS. BY NO
MEANS A GUARANTEE BUT THATS THE LATEST 411.
SNELSON
&&
.AVIATION...
06Z UPDATE...
A FEW AREAS OF STRATUS HAVE BEGUN TO DEVELOP AND SHOULD BECOME
MOSTLY IFR CIGS BY LATER THIS MORNING...RISING TO VFR BY NOON.
ISOLATED/SCATTERED SHOWERS WILL MOVE INTO THE WESTERN TAF AREAS
THIS MORNING AND BECOMING WIDESPREAD OVER ALL THE FORECAST AREA
THIS AFTERNOON...DIMINISHING AFTER SUNSET. WINDS WILL REMAIN LIGHT
SOUTHWEST THROUGH THE FORECAST EXCEPT GUSTY IN STORMS.
//ATL CONFIDENCE...06Z UPDATE...
LOW TO MEDIUM ON CIGS THIS MORNING
MEDIUM ON TIMING OF SHRA/TSRA
HIGH ON REMAINING ELEMENTS
17
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 89 73 89 73 / 70 70 70 30
ATLANTA 87 73 87 73 / 70 70 70 30
BLAIRSVILLE 81 68 80 66 / 80 80 70 30
CARTERSVILLE 87 72 86 70 / 80 80 70 30
COLUMBUS 89 74 90 75 / 70 70 60 30
GAINESVILLE 85 72 85 72 / 70 70 70 30
MACON 91 74 91 74 / 70 70 60 30
ROME 86 72 85 71 / 80 80 70 30
PEACHTREE CITY 88 72 88 72 / 70 70 70 30
VIDALIA 91 75 92 76 / 70 60 50 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...17
LONG TERM....SNELSON
AVIATION...17
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
424 PM EDT WED AUG 19 2015
.UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 242 PM EDT WED AUG 19 2015
TWO SYSTEMS WILL IMPACT THE WEATHER ACROSS CENTRAL INDIANA OVER
THE FORECAST PERIOD. THE FIRST IS CURRENTLY MAKING ITS WAY INTO
THE UPPER MIDWEST...AND ITS ASSOCIATED COLD FRONT WILL TRIGGER
SHOWERS AND THUNDERSTORMS ACROSS THE AREA THIS EVENING AND INTO
TONIGHT. AFTER A DRY PERIOD FROM HIGH PRESSURE THROUGH
SATURDAY...ANOTHER SYSTEM WILL INITIATE CONVECTIVE DEVELOPMENT
SUNDAY AFTERNOON AND NIGHT. FURTHER OUT...HIGH PRESSURE WILL
RETURN AT THE BEGINNING OF NEXT WEEK.
&&
.NEAR TERM /THIS EVENING AND TONIGHT/...
ISSUED AT 242 PM EDT WED AUG 19 2015
THE MAIN FOCUS OF THE NEAR TERM PERIOD IS SHOWER AND
THUNDERSTORM CHANCES AS COLD FRONT ENTERS CENTRAL INDIANA.
SYNOPTICALLY...A RATHER STRONG LOW PRESSURE SYSTEM IS CURRENTLY
ROTATING OVER THE UPPER MIDWEST WHILE ITS ASSOCIATED COLD FRONT
MAKES ITS WAY INTO NORTHWEST INDIANA. RADAR TRENDS HAVE BEEN
LEANING TOWARD INCREASING CONVECTIVE DEVELOPMENT ACROSS CENTRAL
INDIANA OVER THE LAST FEW HOURS AND WILL CONTINUE TO STRENGTHEN
THROUGH THU 06Z AS AFOREMENTIONED COLD FRONT APPROACHES CENTRAL
INDIANA.
BEST FRONTOGENETIC FORCING IN LOWER AND MID LEVELS WILL BE DURING
THE THU 06-12Z TIME FRAME FROM WEST/NORTHWEST TO EAST/SOUTHEAST
ACROSS FORECAST AREA. NONETHELESS...SUBSTANTIAL MOISTURE AND
AFTERNOON HEATING AHEAD OF THE FRONT WILL BE ENOUGH TO SUSTAIN
PRE-FRONTAL SHOWERS AND THUNDERSTORMS THIS EVENING...WITH
POTENTIAL FOR ISOLATED STRONG TO SEVERE DEVELOPMENT AT TIMES.
TEMPS WILL FALL BELOW NORMAL TONIGHT IN WAKE OF COLD FRONT WITH
OVERNIGHT LOWS DIPPING INTO THE UPPER 50S/LOW 60S. SOME MID 50S
CAN EVEN BE EXPECTED ACROSS THE NORTHWEST PORTIONS OF THE FORECAST
AREA. MODELS SEEM TO HAVE A GOOD HANDLE ON THE FRONTAL
PASSAGE...SO STUCK CLOSE TO A BLEND.
&&
.SHORT TERM /TOMORROW THROUGH SATURDAY/...
ISSUED AT 242 PM EDT WED AUG 19 2015
COLD FRONT WILL BE THROUGH THE FORECAST AREA BY THU 12Z...BUT
RESIDUAL CLOUD COVER WILL LINGER ACROSS THE EASTERN COUNTIES
TOMORROW MORNING UNTIL THE ASSOCIATED UPPER LOW PUSHES FARTHER
EAST. AFTER THAT...FLOW WILL BECOME MORE ZONAL ALOFT AND HIGH
PRESSURE WILL STRENGTHEN AT THE SURFACE OVER THE OHIO VALLEY.
SO...DRY CONDITIONS CAN BE EXPECTED INTO SATURDAY.
TEMPERATURES WILL START OUT WELL BELOW NORMAL FOR THE FIRST HALF
OF THE SHORT TERM PERIOD AS THEY TRY TO REBOUND FROM THE
AFOREMENTIONED COLD FRONT. SO...HIGHS WILL ONLY BE IN THE MID TO
UPPER 70S FOR THURSDAY...AND UPPER 70S/LOW 80S BY FRIDAY. THEY
WILL START TO RECOVER BY SATURDAY THOUGH WITH MORE WIDESPREAD LOW
80S. MEANWHILE...DECENT RADIATIONAL COOLING AT NIGHT WILL KEEP
LOWS SIGNIFICANTLY BELOW NORMAL WITH READINGS IN THE 50S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
ISSUED AT 201 PM EDT WED AUG 19 2015
ECMWF AND GFS BLEND PRETTY WELL DURING THE PERIOD. BOTH MODELS
SUGGEST A DECENT COLD FRONT ALONG WITH A SHORT WAVE ALOFT PASSING
THROUGH CENTRAL INDIANA ON SUNDAY NIGHT INTO EARLY MONDAY. A WARM
AND MOIST AIR MASS ALONG WITH SOUTHERLY FLOW MAY ALSO LEAD TO SOME
AFTERNOON PEAK HEATING DAYTIME CONVECTION ACROSS CENTRAL INDIANA.
THUS HAVE INCLUDED POPS STARTING SUNDAY AFTERNOON THROUGH LATE
SUNDAY NIGHT.
HIGH PRESSURE LOOKS TO RETURN TO THE AREA ON MONDAY AND NORTHWEST
FLOW RESUMES ALOFT AND AN UPPER LOW CONTINUE TO PULL NORTHEAST
TOWARD QUEBEC. THIS ALONG WITH HIGH PRESSURE IN PLACE AT THE
SURFACE WILL ALLOW FOR SUBSIDENCE AND DRY WEATHER ACROSS CENTRAL
INDIANA.
LOOK FOR TEMPS TO BE AT OR BELOW NORMALS THROUGH THIS PERIOD AS
NORTHWEST FLOW IS EXPECTED TO PERSIST THROUGH MUCH OF THE PERIOD.
&&
.AVIATION /DISCUSSION FOR THE 192100Z TAF UPDATE/...
ISSUED AT 424 PM EDT WED AUG 19 2015
BULK OF TSRA REMAINS WELL SOUTH OF KIND...AND RECENT TRENDS INDICATE
THAT THIS WILL CONTINUE THE NEXT FEW HOURS. HAVE THUS CHANGED VCTS
TO VCSH FOR THE NEXT FEW HOURS. STILL EXPECTING SOME DEVELOPMENT OF
TSRA WITH COLD FRONT THIS EVENING SO LEFT TEMPO TSRA GROUP IN FOR
NOW.
PREVIOUS DISCUSSION FOLLOWS...
VFR CONDITIONS EXPECTED FOR THE NEXT FEW HOURS. MVFR CONDITIONS WILL
BE EXPECTED THIS AFTERNOON AND OVERNIGHT. A RETURN TO VFR IS
EXPECTED AFTER 14Z THURSDAY.
CONVECTIVE TEMPS IN THE LOWER 80S ARE EXPECTED TO BE REACHED
MOMENTARILY. TSRA DEVELOPMENT IS EXPECTED ACROSS SOUTHERN
ILLINOIS AND WESTERN INDIANA AHEAD OF THE APPROACHING FRONTAL
BOUNDARY. HRRR SHOWS AREAS OF THUNDERSTORMS DEVELOPING AND
PUSHING ACROSS CENTRAL INDIANA DURING THE PEAK HEATING HOURS AND
EARLY THIS EVENING. THUS WILL INCLUDE A PERIOD OF VCSH ALONG WITH
A TEMPO PERIOD FOR THUNDER DURING THE MOST FAVORABLE WINDOW FOR
THUNDERSTORMS.
AFTER DYNAMICS AND FORCING MOVES EAST AFTER 06Z...FORECAST
SOUNDINGS AND TIME HEIGHTS ALONG WITH THE SUGGESTION OF RECENT
RAINS INDICATE LOWER LEVEL MOISTURE AND STRATOCU/MVFR FOG
LINGERING OVERNIGHT.
AS HIGH PRESSURE ARRIVES IN THE AREA ON THURSDAY ALONG WITH
SUBSIDENCE...A QUICK RETURN TO VFR IS EXPECTED.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM....PUMA
AVIATION...JP/50
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
359 PM EDT WED AUG 19 2015
.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 242 PM EDT WED AUG 19 2015
TWO SYSTEMS WILL IMPACT THE WEATHER ACROSS CENTRAL INDIANA OVER
THE FORECAST PERIOD. THE FIRST IS CURRENTLY MAKING ITS WAY INTO
THE UPPER MIDWEST...AND ITS ASSOCIATED COLD FRONT WILL TRIGGER
SHOWERS AND THUNDERSTORMS ACROSS THE AREA THIS EVENING AND INTO
TONIGHT. AFTER A DRY PERIOD FROM HIGH PRESSURE THROUGH
SATURDAY...ANOTHER SYSTEM WILL INITIATE CONVECTIVE DEVELOPMENT
SUNDAY AFTERNOON AND NIGHT. FURTHER OUT...HIGH PRESSURE WILL
RETURN AT THE BEGINNING OF NEXT WEEK.
&&
.NEAR TERM /THIS EVENING AND TONIGHT/...
ISSUED AT 242 PM EDT WED AUG 19 2015
THE MAIN FOCUS OF THE NEAR TERM PERIOD IS SHOWER AND
THUNDERSTORM CHANCES AS COLD FRONT ENTERS CENTRAL INDIANA.
SYNOPTICALLY...A RATHER STRONG LOW PRESSURE SYSTEM IS CURRENTLY
ROTATING OVER THE UPPER MIDWEST WHILE ITS ASSOCIATED COLD FRONT
MAKES ITS WAY INTO NORTHWEST INDIANA. RADAR TRENDS HAVE BEEN
LEANING TOWARD INCREASING CONVECTIVE DEVELOPMENT ACROSS CENTRAL
INDIANA OVER THE LAST FEW HOURS AND WILL CONTINUE TO STRENGTHEN
THROUGH THU 06Z AS AFOREMENTIONED COLD FRONT APPROACHES CENTRAL
INDIANA.
BEST FRONTOGENETIC FORCING IN LOWER AND MID LEVELS WILL BE DURING
THE THU 06-12Z TIME FRAME FROM WEST/NORTHWEST TO EAST/SOUTHEAST
ACROSS FORECAST AREA. NONETHELESS...SUBSTANTIAL MOISTURE AND
AFTERNOON HEATING AHEAD OF THE FRONT WILL BE ENOUGH TO SUSTAIN
PRE-FRONTAL SHOWERS AND THUNDERSTORMS THIS EVENING...WITH
POTENTIAL FOR ISOLATED STRONG TO SEVERE DEVELOPMENT AT TIMES.
TEMPS WILL FALL BELOW NORMAL TONIGHT IN WAKE OF COLD FRONT WITH
OVERNIGHT LOWS DIPPING INTO THE UPPER 50S/LOW 60S. SOME MID 50S
CAN EVEN BE EXPECTED ACROSS THE NORTHWEST PORTIONS OF THE FORECAST
AREA. MODELS SEEM TO HAVE A GOOD HANDLE ON THE FRONTAL
PASSAGE...SO STUCK CLOSE TO A BLEND.
&&
.SHORT TERM /TOMORROW THROUGH SATURDAY/...
ISSUED AT 242 PM EDT WED AUG 19 2015
COLD FRONT WILL BE THROUGH THE FORECAST AREA BY THU 12Z...BUT
RESIDUAL CLOUD COVER WILL LINGER ACROSS THE EASTERN COUNTIES
TOMORROW MORNING UNTIL THE ASSOCIATED UPPER LOW PUSHES FARTHER
EAST. AFTER THAT...FLOW WILL BECOME MORE ZONAL ALOFT AND HIGH
PRESSURE WILL STRENGTHEN AT THE SURFACE OVER THE OHIO VALLEY.
SO...DRY CONDITIONS CAN BE EXPECTED INTO SATURDAY.
TEMPERATURES WILL START OUT WELL BELOW NORMAL FOR THE FIRST HALF
OF THE SHORT TERM PERIOD AS THEY TRY TO REBOUND FROM THE
AFOREMENTIONED COLD FRONT. SO...HIGHS WILL ONLY BE IN THE MID TO
UPPER 70S FOR THURSDAY...AND UPPER 70S/LOW 80S BY FRIDAY. THEY
WILL START TO RECOVER BY SATURDAY THOUGH WITH MORE WIDESPREAD LOW
80S. MEANWHILE...DECENT RADIATIONAL COOLING AT NIGHT WILL KEEP
LOWS SIGNIFICANTLY BELOW NORMAL WITH READINGS IN THE 50S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
ISSUED AT 201 PM EDT WED AUG 19 2015
ECMWF AND GFS BLEND PRETTY WELL DURING THE PERIOD. BOTH MODELS
SUGGEST A DECENT COLD FRONT ALONG WITH A SHORT WAVE ALOFT PASSING
THROUGH CENTRAL INDIANA ON SUNDAY NIGHT INTO EARLY MONDAY. A WARM
AND MOIST AIR MASS ALONG WITH SOUTHERLY FLOW MAY ALSO LEAD TO SOME
AFTERNOON PEAK HEATING DAYTIME CONVECTION ACROSS CENTRAL INDIANA.
THUS HAVE INCLUDED POPS STARTING SUNDAY AFTERNOON THROUGH LATE
SUNDAY NIGHT.
HIGH PRESSURE LOOKS TO RETURN TO THE AREA ON MONDAY AND NORTHWEST
FLOW RESUMES ALOFT AND AN UPPER LOW CONTINUE TO PULL NORTHEAST
TOWARD QUEBEC. THIS ALONG WITH HIGH PRESSURE IN PLACE AT THE
SURFACE WILL ALLOW FOR SUBSIDENCE AND DRY WEATHER ACROSS CENTRAL
INDIANA.
LOOK FOR TEMPS TO BE AT OR BELOW NORMALS THROUGH THIS PERIOD AS
NORTHWEST FLOW IS EXPECTED TO PERSIST THROUGH MUCH OF THE PERIOD.
&&
.AVIATION /DISCUSSION FOR THE 191800Z IND TAFS/...
ISSUED AT 116 PM EDT WED AUG 19 2015
VFR CONDITIONS EXPECTED FOR THE NEXT FEW HOURS. MVFR CONDITIONS
WILL BE EXPECTED THIS AFTERNOON AND OVERNIGHT. A RETURN TO VFR IS
EXPECTED AFTER 14Z THURSDAY.
CONVECTIVE TEMPS IN THE LOWER 80S ARE EXPECTED TO BE REACHED
MOMENTARILY. TSRA DEVELOPMENT IS EXPECTED ACROSS SOUTHERN
ILLINOIS AND WESTERN INDIANA AHEAD OF THE APPROACHING FRONTAL
BOUNDARY. HRRR SHOWS AREAS OF THUNDERSTORMS DEVELOPING AND
PUSHING ACROSS CENTRAL INDIANA DURING THE PEAK HEATING HOURS AND
EARLY THIS EVENING. THUS WILL INCLUDE A PERIOD OF VCSH ALONG WITH
A TEMPO PERIOD FOR THUNDER DURING THE MOST FAVORABLE WINDOW FOR
THUNDERSTORMS.
AFTER DYNAMICS AND FORCING MOVES EAST AFTER 06Z...FORECAST
SOUNDINGS AND TIME HEIGHTS ALONG WITH THE SUGGESTION OF RECENT
RAINS INDICATE LOWER LEVEL MOISTURE AND STRATOCU/MVFR FOG
LINGERING OVERNIGHT.
AS HIGH PRESSURE ARRIVES IN THE AREA ON THURSDAY ALONG WITH
SUBSIDENCE...A QUICK RETURN TO VFR IS EXPECTED.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM....PUMA
AVIATION...JP
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
208 PM EDT WED AUG 19 2015
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 218 AM EDT WED AUG 19 2015
A STRONG FRONTAL SYSTEM...FOR THIS TIME OF YEAR...WILL BRING
WIDESPREAD THUNDERSTORMS TO CENTRAL INDIANA TODAY AND TONIGHT. SOME
OF THE STORMS COULD BE STRONG OR POSSIBLY EVEN SEVERE. THEN...HIGH
PRESSURE WILL PROVIDE FOR DRY CONDITIONS THROUGH SATURDAY. ANOTHER
SEASONABLY STRONG FRONTAL SYSTEM WILL BRING MORE STORMS TO THE AREA
SUNDAY AND SUNDAY NIGHT BEFORE HIGH PRESSURE AND DRY WEATHER RETURN
MONDAY.
TEMPERATURES WILL BE BELOW NORMAL...ESPECIALLY LATE THIS WORK WEEK
AND EARLY NEXT WEEK FOLLOWING THE FRONTAL PASSAGES...WHEN HIGHS WILL
BE IN THE 70S AND LOWS IN THE 50S.
&&
.NEAR TERM /REST OF TODAY AND TONIGHT/...
ISSUED AT 947 AM EDT WED AUG 19 2015
UPDATE...
LATEST RADAR MOSAIC SHOWS SCATTERED SHOWERS CONFINED TO THE FAR
SOUTHERN TIER OF COUNTIES IN CENTRAL INDIANA. THIS CORRELATES WELL
WITH LOCATION OF BEST INSTABILITY AT THIS HOUR. CONVECTIVE
ACTIVITY IS STILL EXPECTED TO BECOME MORE WIDESPREAD AND STRONGER
THROUGH THE COURSE OF THE AFTERNOON AS COLD FRONT APPROACHES FROM
THE WEST. PLUS...THE FIRST WAVE OF SHOWERS AND THUNDERSTORMS HAVE
STAYED FARTHER SOUTH THAN ORIGINALLY ANTICIPATED. SO...WITH MORE
BREAKS IN CLOUD COVER...THE FRONT MAY HAVE MORE INSTABILITY TO
WORK WITH ACROSS THE NORTHERN TWO-THIRDS OF THE FORECAST AREA
LATER TODAY.
CURRENT TEMPS ACROSS THE AREA ARE GENERALLY IN THE 70S WITH
DEWPOINTS IN THE MID TO UPPER 60S. WINDS ARE SOUTH/SOUTHWESTERLY
AT 10 TO 14 MPH...GUSTING TO 21 MPH.
PREVIOUS DISCUSSIONS...
ISSUED AT 620 AM EDT WED AUG 19 2015
LATEST RADAR TRENDS ARE BRINGING WIDESPREAD SHOWERS AND EMBEDDED
THUNDERSTORMS TO ABOUT AN INDIANAPOLIS TO LAFAYETTE LINE AROUND 8
AM. RAISED POPS TO CATEGORICAL SLIGHTLY EARLIER. FIRST WAVE OF
STORMS SHOULD BE EAST OF THE AREA AROUND 16Z WITH STORMS DEVELOPING
AND ALSO MOVING IN FROM THE WEST SHORTLY THEREAFTER. THIS SHOULD
KEEP THINGS FROM BECOMING TO UNSTABLE AND SUPPORTS THE MARGINAL
SEVERE RISK AS OPPOSED TO SLIGHT RISK.
PREVIOUS DISCUSSION FOLLOWS...
ISSUED AT 218 AM EDT WED AUG 19 2015
THUNDERSTORMS...SOME STRONG AND POSSIBLY SEVERE...WILL BE THE MAIN
FOCUS FOR THE NEAR TERM AS A STRONG LOW PRESSURE SYSTEM...FOR LATE
AUGUST...LIFTS NORTHEAST ACROSS LAKE SUPERIOR AND NORTHWEST ONTARIO
DRAGGING A COLD FRONT ACROSS CENTRAL INDIANA.
RAP13 AND HIGH RES RAPID REFRESH SEEM TO HAVE A DECENT HANDLE ON
CONVECTIVE EVOLUTION COMPARED TO THE LATEST RADAR TRENDS.
THUNDERSTORMS WERE LIFTING NORTHEAST OVER NORTHWESTERN PARTS OF
CENTRAL INDIANA EARLY THIS OVERNIGHT AND THE REFLECTIVITY PROGS FROM
THE RAPID REFRESH WERE BRINGING THE INDIVIDUAL STORMS NORTHEAST BUT
THE AREA OF CONVECTION SOUTHEAST AHEAD OF A COLD FRONT THAT EXTENDED
FROM A SURFACE LOW OVER SOUTH CENTRAL MINNESOTA TO NORTHEASTERN
MISSOURI AND NORTHEASTERN OKLAHOMA. THE GFS CONTINUES TO BE A FAST
OUTLIER WITH ITS 00Z WEDNESDAY RUN WITH REGARDS TO THE FRONTAL
PASSAGE OVER CENTRAL INDIANA AND THUS WILL BE IGNORED WITH A BLEND
BETWEEN THE OTHER SIMILAR OPERATIONAL MODELS ACCEPTED. NON-GFS BLEND
TAKES THE COLD FRONT TO NEAR CHICAGO TO ST. LOUIS LINE 12Z THIS
MORNING...TO A VALPO TO CARBONDALE LINE AT 18Z AND TO AROUND A FORT
WAYNE TO INDIANAPOLIS LINE BY 00Z THURSDAY. MEANWHILE...THE FRONT
SHOULD BE THROUGH CENTRAL OHIO AND EASTERN KENTUCKY BY 12Z THURSDAY
WHICH SHOULD PUT AN END TO THE CONVECTION FROM NORTHWEST TO
SOUTHEAST OVERNIGHT TONIGHT. HOWEVER...PRIOR TO THAT...THE RAPID
REFRESH WAS BRINGING EASTERN MISSOURI STORMS OVER CENTRAL INDIANA IN
THE 11Z-15Z TIME FRAME. MEANWHILE...MORE WIDESPREAD STORMS ARE
EXPECTED THIS AFTERNOON AS THE FRONT GETS CLOSER.
MODELS MAY BE OVERDOING IT A LITTLE ON INSTABILITY AS BREAK BETWEEN
MORNING AND AFTERNOON CONVECTION SHOULD NOT BE TOO LONG. THAT
SAID...EVEN THE LEAST UNSTABLE ECMWF HAD 500 J/KG OR MORE MIXED
LAYER CAPE TODAY TO GO ALONG WITH THE DYNAMICS. 20-30 KNOT LOW LEVEL
JET ACROSS WEST CENTRAL INDIANA AND APPROACHING NEGATIVELY-TILTED
TROUGH SUGGESTS LIKELY TO CATEGORICAL POPS THROUGH THIS EVENING
BEFORE DROPPING OFF FROM NORTHWEST TO SOUTHEAST LATE TONIGHT. FAST
UPPER JET AROUND THE BASE OF THE TROUGH WILL PUSH INDIVIDUAL CELLS
THROUGH QUICKLY...SO DO NOT FORESEE A BIG FLASH FLOOD THREAT DESPITE
THE DYNAMICS AND PRECIPITABLE WATER AMOUNTS TO 2 INCHES. REGARDING
SEVERE THREAT...AREA CONTINUES TO BE IN A MARGINAL RISK FOR THIS
AFTERNOON AND EVENING. THIS LOOKS REASONABLE. ISOLATED DAMAGING
WINDS WILL BE THE MAIN SEVERE THREAT.
WITH LITTLE BREAKS IN THE CLOUDS TODAY...WENT WITH THE COOLEST 00Z
NAM MOS WITH HIGHS IN THE UPPER 70S AND LOWER 80S. MOS LOWS CLOSE
TONIGHT AND LOOK REASONABLE. COOLEST TEMPERATURES WILL BE
NORTHWESTERN PARTS...WHERE BREAKS IN THE CLOUDS WILL OCCUR FIRST
BEHIND THE FRONT. WILL BE A LITTLE CHILLY WITH LOWS IN THE UPPER 50S
TO LOWER 60S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
ISSUED AT 218 AM EDT WED AUG 19 2015
MAIN FOCUS FOR THE SHORT TERM WILL BE ON TEMPERATURES AS SURFACE
HIGH PRESSURE BUILDS OVER THE OHIO VALLEY BY LATE THURSDAY BEHIND
THE COLD FRONT AND TRAILING UPPER TROUGH ALLOWING FOR CLEAR SKIES
AND COOL TEMPERATURES FOR THIS TIME OF YEAR. THE HIGH WILL SHIFT TO
SOUTHERN ONTARIO BY FRIDAY NIGHT...BUT DRY COLUMN AND FRONTAL SYSTEM
WELL TO THE WEST SHOULD ENSURE DRY WEATHER.
LOW LEVEL THERMAL PROGS AND LITTLE CLOUD COVER SUPPORT SIMILAR BLEND
OF 00Z MOS WITH AFTERNOON HIGHS IN THE MID AND UPPER 70S ON THURSDAY
AND UPPER 70S TO LOWER 80S ON FRIDAY. WITH STRONG RADIATIONAL
COOLING...IT WILL BE QUITE COOL WITH OVERNIGHT LOWS IN THE 50S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
ISSUED AT 201 PM EDT WED AUG 19 2015
ECMWF AND GFS BLEND PRETTY WELL DURING THE PERIOD. BOTH MODELS
SUGGEST A DECENT COLD FRONT ALONG WITH A SHORT WAVE ALOFT PASSING
THROUGH CENTRAL INDIANA ON SUNDAY NIGHT INTO EARLY MONDAY. A WARM
AND MOIST AIR MASS ALONG WITH SOUTHERLY FLOW MAY ALSO LEAD TO SOME
AFTERNOON PEAK HEATING DAYTIME CONVECTION ACROSS CENTRAL INDIANA.
THUS HAVE INCLUDED POPS STARTING SUNDAY AFTERNOON THROUGH LATE
SUNDAY NIGHT.
HIGH PRESSURE LOOKS TO RETURN TO THE AREA ON MONDAY AND NORTHWEST
FLOW RESUMES ALOFT AND AN UPPER LOW CONTINUE TO PULL NORTHEAST
TOWARD QUEBEC. THIS ALONG WITH HIGH PRESSURE IN PLACE AT THE
SURFACE WILL ALLOW FOR SUBSIDENCE AND DRY WEATHER ACROSS CENTRAL
INDIANA.
LOOK FOR TEMPS TO BE AT OR BELOW NORMALS THROUGH THIS PERIOD AS
NORTHWEST FLOW IS EXPECTED TO PERSIST THROUGH MUCH OF THE PERIOD.
&&
.AVIATION /DISCUSSION FOR THE 191800Z IND TAFS/...
ISSUED AT 116 PM EDT WED AUG 19 2015
VFR CONDITIONS EXPECTED FOR THE NEXT FEW HOURS. MVFR CONDITIONS
WILL BE EXPECTED THIS AFTERNOON AND OVERNIGHT. A RETURN TO VFR IS
EXPECTED AFTER 14Z THURSDAY.
CONVECTIVE TEMPS IN THE LOWER 80S ARE EXPECTED TO BE REACHED
MOMENTARILY. TSRA DEVELOPMENT IS EXPECTED ACROSS SOUTHERN
ILLINOIS AND WESTERN INDIANA AHEAD OF THE APPROACHING FRONTAL
BOUNDARY. HRRR SHOWS AREAS OF THUNDERSTORMS DEVELOPING AND
PUSHING ACROSS CENTRAL INDIANA DURING THE PEAK HEATING HOURS AND
EARLY THIS EVENING. THUS WILL INCLUDE A PERIOD OF VCSH ALONG WITH
A TEMPO PERIOD FOR THUNDER DURING THE MOST FAVORABLE WINDOW FOR
THUNDERSTORMS.
AFTER DYNAMICS AND FORCING MOVES EAST AFTER 06Z...FORECAST
SOUNDINGS AND TIME HEIGHTS ALONG WITH THE SUGGESTION OF RECENT
RAINS INDICATE LOWER LEVEL MOISTURE AND STRATOCU/MVFR FOG
LINGERING OVERNIGHT.
AS HIGH PRESSURE ARRIVES IN THE AREA ON THURSDAY ALONG WITH
SUBSIDENCE...A QUICK RETURN TO VFR IS EXPECTED.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MK
NEAR TERM...MK/TDUD
SHORT TERM...MK
LONG TERM....PUMA
AVIATION...JP
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
116 PM EDT WED AUG 19 2015
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 218 AM EDT WED AUG 19 2015
A STRONG FRONTAL SYSTEM...FOR THIS TIME OF YEAR...WILL BRING
WIDESPREAD THUNDERSTORMS TO CENTRAL INDIANA TODAY AND TONIGHT. SOME
OF THE STORMS COULD BE STRONG OR POSSIBLY EVEN SEVERE. THEN...HIGH
PRESSURE WILL PROVIDE FOR DRY CONDITIONS THROUGH SATURDAY. ANOTHER
SEASONABLY STRONG FRONTAL SYSTEM WILL BRING MORE STORMS TO THE AREA
SUNDAY AND SUNDAY NIGHT BEFORE HIGH PRESSURE AND DRY WEATHER RETURN
MONDAY.
TEMPERATURES WILL BE BELOW NORMAL...ESPECIALLY LATE THIS WORK WEEK
AND EARLY NEXT WEEK FOLLOWING THE FRONTAL PASSAGES...WHEN HIGHS WILL
BE IN THE 70S AND LOWS IN THE 50S.
&&
.NEAR TERM /REST OF TODAY AND TONIGHT/...
ISSUED AT 947 AM EDT WED AUG 19 2015
UPDATE...
LATEST RADAR MOSAIC SHOWS SCATTERED SHOWERS CONFINED TO THE FAR
SOUTHERN TIER OF COUNTIES IN CENTRAL INDIANA. THIS CORRELATES WELL
WITH LOCATION OF BEST INSTABILITY AT THIS HOUR. CONVECTIVE
ACTIVITY IS STILL EXPECTED TO BECOME MORE WIDESPREAD AND STRONGER
THROUGH THE COURSE OF THE AFTERNOON AS COLD FRONT APPROACHES FROM
THE WEST. PLUS...THE FIRST WAVE OF SHOWERS AND THUNDERSTORMS HAVE
STAYED FARTHER SOUTH THAN ORIGINALLY ANTICIPATED. SO...WITH MORE
BREAKS IN CLOUD COVER...THE FRONT MAY HAVE MORE INSTABILITY TO
WORK WITH ACROSS THE NORTHERN TWO-THIRDS OF THE FORECAST AREA
LATER TODAY.
CURRENT TEMPS ACROSS THE AREA ARE GENERALLY IN THE 70S WITH
DEWPOINTS IN THE MID TO UPPER 60S. WINDS ARE SOUTH/SOUTHWESTERLY
AT 10 TO 14 MPH...GUSTING TO 21 MPH.
PREVIOUS DISCUSSIONS...
ISSUED AT 620 AM EDT WED AUG 19 2015
LATEST RADAR TRENDS ARE BRINGING WIDESPREAD SHOWERS AND EMBEDDED
THUNDERSTORMS TO ABOUT AN INDIANAPOLIS TO LAFAYETTE LINE AROUND 8
AM. RAISED POPS TO CATEGORICAL SLIGHTLY EARLIER. FIRST WAVE OF
STORMS SHOULD BE EAST OF THE AREA AROUND 16Z WITH STORMS DEVELOPING
AND ALSO MOVING IN FROM THE WEST SHORTLY THEREAFTER. THIS SHOULD
KEEP THINGS FROM BECOMING TO UNSTABLE AND SUPPORTS THE MARGINAL
SEVERE RISK AS OPPOSED TO SLIGHT RISK.
PREVIOUS DISCUSSION FOLLOWS...
ISSUED AT 218 AM EDT WED AUG 19 2015
THUNDERSTORMS...SOME STRONG AND POSSIBLY SEVERE...WILL BE THE MAIN
FOCUS FOR THE NEAR TERM AS A STRONG LOW PRESSURE SYSTEM...FOR LATE
AUGUST...LIFTS NORTHEAST ACROSS LAKE SUPERIOR AND NORTHWEST ONTARIO
DRAGGING A COLD FRONT ACROSS CENTRAL INDIANA.
RAP13 AND HIGH RES RAPID REFRESH SEEM TO HAVE A DECENT HANDLE ON
CONVECTIVE EVOLUTION COMPARED TO THE LATEST RADAR TRENDS.
THUNDERSTORMS WERE LIFTING NORTHEAST OVER NORTHWESTERN PARTS OF
CENTRAL INDIANA EARLY THIS OVERNIGHT AND THE REFLECTIVITY PROGS FROM
THE RAPID REFRESH WERE BRINGING THE INDIVIDUAL STORMS NORTHEAST BUT
THE AREA OF CONVECTION SOUTHEAST AHEAD OF A COLD FRONT THAT EXTENDED
FROM A SURFACE LOW OVER SOUTH CENTRAL MINNESOTA TO NORTHEASTERN
MISSOURI AND NORTHEASTERN OKLAHOMA. THE GFS CONTINUES TO BE A FAST
OUTLIER WITH ITS 00Z WEDNESDAY RUN WITH REGARDS TO THE FRONTAL
PASSAGE OVER CENTRAL INDIANA AND THUS WILL BE IGNORED WITH A BLEND
BETWEEN THE OTHER SIMILAR OPERATIONAL MODELS ACCEPTED. NON-GFS BLEND
TAKES THE COLD FRONT TO NEAR CHICAGO TO ST. LOUIS LINE 12Z THIS
MORNING...TO A VALPO TO CARBONDALE LINE AT 18Z AND TO AROUND A FORT
WAYNE TO INDIANAPOLIS LINE BY 00Z THURSDAY. MEANWHILE...THE FRONT
SHOULD BE THROUGH CENTRAL OHIO AND EASTERN KENTUCKY BY 12Z THURSDAY
WHICH SHOULD PUT AN END TO THE CONVECTION FROM NORTHWEST TO
SOUTHEAST OVERNIGHT TONIGHT. HOWEVER...PRIOR TO THAT...THE RAPID
REFRESH WAS BRINGING EASTERN MISSOURI STORMS OVER CENTRAL INDIANA IN
THE 11Z-15Z TIME FRAME. MEANWHILE...MORE WIDESPREAD STORMS ARE
EXPECTED THIS AFTERNOON AS THE FRONT GETS CLOSER.
MODELS MAY BE OVERDOING IT A LITTLE ON INSTABILITY AS BREAK BETWEEN
MORNING AND AFTERNOON CONVECTION SHOULD NOT BE TOO LONG. THAT
SAID...EVEN THE LEAST UNSTABLE ECMWF HAD 500 J/KG OR MORE MIXED
LAYER CAPE TODAY TO GO ALONG WITH THE DYNAMICS. 20-30 KNOT LOW LEVEL
JET ACROSS WEST CENTRAL INDIANA AND APPROACHING NEGATIVELY-TILTED
TROUGH SUGGESTS LIKELY TO CATEGORICAL POPS THROUGH THIS EVENING
BEFORE DROPPING OFF FROM NORTHWEST TO SOUTHEAST LATE TONIGHT. FAST
UPPER JET AROUND THE BASE OF THE TROUGH WILL PUSH INDIVIDUAL CELLS
THROUGH QUICKLY...SO DO NOT FORESEE A BIG FLASH FLOOD THREAT DESPITE
THE DYNAMICS AND PRECIPITABLE WATER AMOUNTS TO 2 INCHES. REGARDING
SEVERE THREAT...AREA CONTINUES TO BE IN A MARGINAL RISK FOR THIS
AFTERNOON AND EVENING. THIS LOOKS REASONABLE. ISOLATED DAMAGING
WINDS WILL BE THE MAIN SEVERE THREAT.
WITH LITTLE BREAKS IN THE CLOUDS TODAY...WENT WITH THE COOLEST 00Z
NAM MOS WITH HIGHS IN THE UPPER 70S AND LOWER 80S. MOS LOWS CLOSE
TONIGHT AND LOOK REASONABLE. COOLEST TEMPERATURES WILL BE
NORTHWESTERN PARTS...WHERE BREAKS IN THE CLOUDS WILL OCCUR FIRST
BEHIND THE FRONT. WILL BE A LITTLE CHILLY WITH LOWS IN THE UPPER 50S
TO LOWER 60S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
ISSUED AT 218 AM EDT WED AUG 19 2015
MAIN FOCUS FOR THE SHORT TERM WILL BE ON TEMPERATURES AS SURFACE
HIGH PRESSURE BUILDS OVER THE OHIO VALLEY BY LATE THURSDAY BEHIND
THE COLD FRONT AND TRAILING UPPER TROUGH ALLOWING FOR CLEAR SKIES
AND COOL TEMPERATURES FOR THIS TIME OF YEAR. THE HIGH WILL SHIFT TO
SOUTHERN ONTARIO BY FRIDAY NIGHT...BUT DRY COLUMN AND FRONTAL SYSTEM
WELL TO THE WEST SHOULD ENSURE DRY WEATHER.
LOW LEVEL THERMAL PROGS AND LITTLE CLOUD COVER SUPPORT SIMILAR BLEND
OF 00Z MOS WITH AFTERNOON HIGHS IN THE MID AND UPPER 70S ON THURSDAY
AND UPPER 70S TO LOWER 80S ON FRIDAY. WITH STRONG RADIATIONAL
COOLING...IT WILL BE QUITE COOL WITH OVERNIGHT LOWS IN THE 50S.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
ISSUED AT 307 AM EDT WED AUG 19 2015
HIGH PRESSURE WILL MOVE NORTHEAST AWAY FROM CENTRAL INDIANA ON
SATURDAY NIGHT ALLOWING A LOW PRESSURE SYSTEM AND ASSOCIATED COLD
FRONT TO SLIDE INTO THE AREA ON SUNDAY. MODELS HAVE TRENDED A
LITTLE SLOWER WITH THE ARRIVAL OF THIS SYSTEM AND THUS SATURDAY
NIGHT NOW LOOKS DRY. THE AFOREMENTIONED COLD FRONT WILL BRING
THUNDERSTORM CHANCES FOR SUNDAY AND SUNDAY NIGHT TO THE AREA. BY
MONDAY THOUGH CANADIAN HIGH PRESSURE WILL BUILD BACK IN OVER
CENTRAL INDIANA AND USHER IN BELOW NORMAL HIGHS IN THE 70S ALONG
WITH DRY WEATHER.
&&
.AVIATION /DISCUSSION FOR THE 191800Z IND TAFS/...
ISSUED AT 116 PM EDT WED AUG 19 2015
VFR CONDITIONS EXPECTED FOR THE NEXT FEW HOURS. MVFR CONDITIONS
WILL BE EXPECTED THIS AFTERNOON AND OVERNIGHT. A RETURN TO VFR IS
EXPECTED AFTER 14Z THURSDAY.
CONVECTIVE TEMPS IN THE LOWER 80S ARE EXPECTED TO BE REACHED
MOMENTARILY. TSRA DEVELOPMENT IS EXPECTED ACROSS SOUTHERN
ILLINOIS AND WESTERN INDIANA AHEAD OF THE APPROACHING FRONTAL
BOUNDARY. HRRR SHOWS AREAS OF THUNDERSTORMS DEVELOPING AND
PUSHING ACROSS CENTRAL INDIANA DURING THE PEAK HEATING HOURS AND
EARLY THIS EVENING. THUS WILL INCLUDE A PERIOD OF VCSH ALONG WITH
A TEMPO PERIOD FOR THUNDER DURING THE MOST FAVORABLE WINDOW FOR
THUNDERSTORMS.
AFTER DYNAMICS AND FORCING MOVES EAST AFTER 06Z...FORECAST
SOUNDINGS AND TIME HEIGHTS ALONG WITH THE SUGGESTION OF RECENT
RAINS INDICATE LOWER LEVEL MOISTURE AND STRATOCU/MVFR FOG
LINGERING OVERNIGHT.
AS HIGH PRESSURE ARRIVES IN THE AREA ON THURSDAY ALONG WITH
SUBSIDENCE...A QUICK RETURN TO VFR IS EXPECTED.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MK
NEAR TERM...MK/TDUD
SHORT TERM...MK
LONG TERM....CP
AVIATION...JP
...UPDATE TO AVIATION FORECAST DISCUSSION...
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 335 PM CDT TUE AUG 18 2015
19Z WATER VAPOR SHOWS A CLOSED UPPER LOW OVER SD WHILE SURFACE OBS
PLACE THE LOW OVER NORTHWEST IA/SOUTHWEST MN BORDER. A STRONG COLD
FRONT EXTENDED SOUTH FROM THE SURFACE LOW THROUGH SOUTHEAST NEB TO
JUST WEST OF SLN. VISIBLE SATELLITE HAS SHOWN SOME BREAKS IN THE
CLOUDS AHEAD OF THE FRONT WHICH HAS ALLOWED TEMPS TO WARM INTO THE
LOWER 80S. THIS WOULD SUPPORT SURFACE BASED CAPE VALUES AROUND
1000J/KG WHILE 0-6 KM SHEAR INCREASES TO AROUND 45 KTS. SO THE
POTENTIAL FOR SEVERE STORMS REMAINS IN PLACE. MODELS SHOW AREA ALONG
AND SOUTH OF I-70 AS THE PLACES THAT SHOULD SEE THE BETTER
INSTABILITY. THEREFORE THINK THIS MAY BE WHERE STRONG TO SEVERE
STORMS DEVELOP THIS AFTERNOON, IF THEY STRENGTHEN. SINCE SURFACE
WINDS HAVE VEERED TO THE SOUTHWEST AHEAD OF THE FRONT, THE POTENTIAL
FOR TORNADOES APPEARS TO REMAIN FAIRLY SMALL. THE RAP AND HRRR,
WHICH HAVE SHOWN A BETTER TIMING FOR THE FRONT, TAKE THE BOUNDARY
EAST OF THE FORECAST AREA BETWEEN 8 AND 9 PM. THE RISK FOR SEVERE
WEATHER SHOULD DIMINISH QUICKLY BEHIND THE FRONT AS COOLER MORE
STABLE AIR COMES IN.
ONCE THE FRONT PASSES EAST, THINK THE REST OF TONIGHT WILL BE FAIRLY
UNEVENTFUL. THERE HAVE BEEN SOME LOWER CLOUDS ACROSS WESTERN NEB
MIST OF THE DAY BUT THE MODELS TEND TO KEEP THE LOWER CLOUDS TO THE
NORTH OVERNIGHT. THEREFORE WITH COLD AIR ADVECTION AND MOST LIKELY
PARTLY CLOUDY SKIES, LOWS IN THE MID AND UPPER 50S LOOKS ON TARGET.
BY LATE TONIGHT AND THROUGH THE MORNING WEDNESDAY, MODELS SWING A
DECENT VORT MAX THROUGH THE BASE OF THE UPPER TROUGH PASSING THROUGH
EASTERN KS. THERE IS NO SIGN OF LOW LEVEL MOISTURE ADVECTION OVER
THE COLD FRONT, BUT THERE IS AN INDICATION OF A SATURATED AIRMASS
ACROSS EAST CENTRAL KS WITH GOOD FRONTOGENESIS AS THE WAVE PASSES
OVERHEAD. BECAUSE OF THIS HAVE CONTINUED WITH SOME CHANCE POPS FOR
RAIN MAINLY OVER EAST CENTRAL KS. THERE SHOULD BE MORE DRY AIR OVER
NORTH CENTRAL AND NORTHEAST KS THAT WILL LIMIT PRECIP CHANCES. THE
COLD AIR ADVECTION WEAKENS THROUGH THE DAY WEDNESDAY, BUT THERE MAY
BE SOME CLOUDS LINGER. THEREFORE HIGHS ARE FORECAST TO TOP OUT IN
THE LOWER AND MID 70S. THIS IS ABOUT 15 DEGREES BELOW NORMAL FOR
THIS TIME OF YEAR.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 335 PM CDT TUE AUG 18 2015
LOWER LEVEL WINDS BACK TO THE WEST WEDNESDAY NIGHT AND THEN
SOUTHWEST INTO THURSDAY NIGHT BRINGING SOME WARMING BACK AND SURFACE
TEMPS SHOULD MODIFY CONSIDERABLY. HAVE KEPT VALUES NEAR TO BELOW
MOS FOR WEDNESDAY NIGHT IN LIGHT WINDS AND CLEAR SKIES. MODELS
TRENDING A BIT COOLER FOR FRIDAY WITH CONTINUED BACKED TO NEAR
SOUTHEAST WITH HIGHS STILL LIKELY CLOSE TO THOSE OF THURSDAY. PRECIP
CHANCES CONTINUE TO LOOK QUITE LOW THROUGH THURSDAY NIGHT. AT LEAST
SOME MOISTURE RETURNS AHEAD OF A WEAK UPPER WAVE FRIDAY...THOUGH
THERE REMAINS TO BE A WIDE DEGREE OF VARIANCE IN BOTH OF THESE
ELEMENTS...WITH A TREND TOWARD LOWER AVAILABLE MOISTURE NOTED. AT
THIS POINT CHANCES FOR ANYTHING MORE THAN ISOLATED PRECIP LOOK LOW.
FOR THE BEGINNING OF THE WEEKEND, RETURN FLOW WILL BE IN PLACE OVER
THE SOUTHERN AND CENTRAL PLAINS AHEAD OF A DEEPENING TROUGH OVER THE
NORTHERN ROCKIES. THIS SYSTEM WILL CONTINUE EASTWARD PROGRESSION
INTO THE DAY SATURDAY AND OVERNIGHT INTO SUNDAY BEFORE IT BECOMES
MORE NEGATIVELY TILTED AND LIFTS THROUGH THE UPPER MISSISSIPPI
VALLEY INTO THE GREAT LAKES REGION BY MONDAY. THIS LARGER SCALE
FEATURE SHOULD BRING ABOUT THE CHANCE OF ELEVATED STORMS FOR
SATURDAY MORNING AS A LLJ SHOULD HELP ENHANCE AN AREA OF ISENTROPIC
LIFT OVER EASTERN KS. INTO THE DAY, SOUNDINGS DO SUGGEST THAT STORM
POTENTIAL MAY BE LIMITED WITH A PRETTY STRONG CAP DEVELOPING OVER
THE REGION. THE BETTER CHANCE FOR THUNDERSTORM REDEVELOPMENT WILL
BE IN THE LATE AFTERNOON INTO THE EARLY EVENING AS SHEAR PROFILES
BECOME A LITTLE MORE ORGANIZED AND WAA INCREASES LOW LEVEL MOISTURE
ALONG WITH INSTABILITY OVER THE REGION. SOME POTENTIAL FOR STRONG
TO SEVERE STORMS COULD EXIST, BUT STILL TOO FAR OUT TO PINPOINT
OVERALL LIKELIHOOD. MODELS SEEM TO BE IN FAIRLY GOOD AGREEMENT FOR
THE MOST PART WITH EASTWARD PROGRESSION OF THE TROUGH. THE GFS
SOLUTION DOES SEEM TO BE THE MORE AGGRESSIVE OF THE SOLUTIONS THOUGH
WITH A DEEPER UPPER LOW AND MORE NORTHERLY PROGRESSION AFTER THE
MONDAY MORNING TIME FRAME. IN THE WAKE OF THIS FALL-LIKE LOOKING
SYSTEM, WILL BE ANOTHER NICE FEW DAYS AS HEIGHTS RISE AND SUBSIDENCE
SETS IN WITH SIGNIFICANT MOISTURE BEING PUSHED SOUTH.
HIGH TEMPS COOL BEHIND THE SYSTEM INTO THE UPPER 70S
AND ONLY CLIMB INTO THE MID 80S BY TUESDAY. LOWS MEANWHILE COULD
FLIRT WITH LOW 50S IN PARTS OF THE AREA BY TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1232 AM CDT WED AUG 19 2015
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...WOLTERS
LONG TERM...65/DRAKE
AVIATION...SANDERS
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
257 PM CDT WED AUG 19 2015
. DISCUSSION... FOR A THIRD DAY IN A ROW...A LARGE SWATH OF RAIN HAS
MOVED NORTHEAST OUT OF THE GULF ACROSS THE CWA AND BROUGHT PLENTIFUL
RAIN TO THE AREA. TODAY HAS BEEN LIKELY THE MOST SUBSTANTIAL FROM A
COVERAGE AND QPF PERSPECTIVE. UPWARDS OF 2 INCHES HAS FALLEN OVER
MANY LOCATIONS WEST OF INTERSTATE 55. FOR THE SHORT TERM RAIN
EXPECTATIONS...THE HRRR ONCE AGAIN HAS DONE AN EXCELLENT JOB ON THE
TIMING AND MOVEMENT OF RAIN. IT SUGGESTS THAT THE WEAKENING TREND
THAT CAN BE SEEN ON RADAR WILL CONTINUE WITH MUCH OF THE CURRENT
ACTIVITY DISSIPATED BEFORE 00Z AND SEE NO REASON THIS SOLUTION WONT
OCCUR. SOME RESIDUAL SHOWERS MAY LINGER INTO THE EVENING HOURS BUT
GENERALLY DRY THROUGH MUCH OF THE NIGHT.
AN UPPER LEVEL TROUGH IS IN THE PROCESS OF SWINGING ACROSS THE UPPER
MISSISSIPPI VALLEY AND WILL CONTINUE TO DO SO BEFORE MOVING
NORTHEAST OVER THE GREAT LAKES THROUGH THURSDAY. A COLD FRONT
ASSOCIATED WITH THIS TROUGH IS CURRENTLY MOVING SOUTHEAST ACROSS
NORTH TEXAS AND NWRN ARKANSAS. THE BOUNDARY SHOULD BE MOVING SEWD
ACROSS NORTHERN LOUISIANA EARLY THURSDAY MORNING. IT DOES APPEAR
THAT THE FRONT WILL STALL SOMEWHERE BETWEEN CENTRAL LA TO OVER
SOUTHEAST LA. ABUNDANT MOISTURE WHICH IS ALREADY IN PLACE IN
COMBINATION WITH CONVERGENCE ALONG THE FRONT WILL BE CONDUCIVE FOR
ANOTHER ROUND OF NUMEROUS SHOWERS AND STORMS THURSDAY. SO HAVE
INCREASED POPS TO 60 TO 80 PERCENT OVER THE CWA. MAY HAVE SLIGHTLY
LESS COVERAGE ON FRIDAY AS THE FRONT DISSOLVES BUT IN THE GRAND
SCHEME OF THINGS...WILL STILL BE QUITE A BIT OF SHOWERS AND STORMS
DEVELOPING.
MEFFER
&&
.AVIATION... A BROAD SHIELD OF LIGHT TO MODERATE RAIN WILL CONTINUE
TO BRING LOW CEILINGS BETWEEN 1000 AND 2500 FEET AND REDUCED
VISIBILITIES AS LOW AS 3 MILES TO KBTR...KMCB...KHDC THROUGH AROUND
21Z. CONDITIONS SHOULD START TO IMPROVE BACK INTO VFR RANGE AFTER
21Z AS THE PRECIPITATION SHIELD DISSIPATES. ON THE LEADING EDGE OF
THE AREA OF RAIN...INCREASED CONVECTIVE INSTABILITY REMAINS IN
PLACE...AND KEEP VCTS WORDING IN FOR THE REMAINDER OF THE TERMINALS
THROUGH 00Z. EXPECT TO SEE A MIX OF SCATTERED TO BROKEN CEILINGS
RANGING FROM 1500 TO 3000 FEET THROUGH THE AFTERNOON HOURS AT THE
REMAINING TERMINALS. VFR CONDITIONS WILL BE FOUND AT ALL TERMINALS
AFTER 00Z...BUT ANOTHER ELEVATED INVERSION SHOULD ALLOW FOR MVFR
CEILINGS AROUND 1500 TO 2500 TO REDEVELOP AROUND 10-11Z TOMORROW
MORNING AND PERSIST THROUGH THE REMAINDER OF THE MORNING HOURS. AT
KMCB...THE INVERSION WILL BE STRONGER AND RESULT IN SOME IFR AND
POSSIBLY LIFR CEILINGS OF 200 TO 300 FEET AND VISIBILITIES DOWN TO 2
MILES OR LESS AT TIMES FROM 10Z THROUGH AROUND 14Z. 32
&&
.MARINE... HAVE MADE SOME SHORT TERM ADJUSTMENTS TO THE WINDS AND
SEAS OVER LAKE PONTCHARTRAIN. LOCALIZED NW WINDS HAVE INCREASED TO A
GOOD 15 KNOTS AND LIKELY 3-4 FOOT SEAS OVER THE LAST FEW HOURS FROM
SWATH OF RAIN MOVING THROUGH. THINKING IS THAT THESE WINDS MAY
MAINTAIN FOR A COUPLE MORE HOURS BEFORE TRENDING BACK DOWN TO 10
KNOTS THIS EVENING.
MAIN ISSUE FOR MARINERS THROUGH AT LEAST FRIDAY WILL BE THE
DEVELOPMENT OF SCATTERED TO NUMEROUS THUNDERSTORMS...WITH THE
POTENTIAL FOR WINDS GUSTING ABOVE 30 KNOTS. OUTSIDE OF THE
THUNDERSTORM THREAT...GENERAL ONSHORE FLOW FROM THE SOUTH WILL
CONTINUE THROUGH THE END OF THE WORK WEEK. SHOULD BE ENOUGH OF A
GRADIENT TODAY TO PRODUCE 10-15 KNOT WINDS OVER THE OPEN WATERS
BEFORE RELAXING BELOW 10 KNOTS IN MOST AREAS FOR THURSDAY THROUGH
SATURDAY. DO NOT SEE A CLEAN FRONTAL PASSAGE ANY TIME SOON...BUT AS
EAST COAST TROF DEEPENS OVER THE WEEKEND...LIGHT OFFSHORE FLOW
SHOULD DEVELOP ON SUNDAY. 35
&&
.DECISION SUPPORT...
DSS CODE....GREEN.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...NONE.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY
ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT
TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 74 89 72 90 / 30 70 20 60
BTR 74 90 74 90 / 30 60 20 60
ASD 76 90 76 90 / 30 70 20 70
MSY 78 88 78 90 / 30 80 20 70
GPT 80 89 78 88 / 30 60 20 50
PQL 78 90 76 89 / 30 60 20 50
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
122 AM EDT WED AUG 19 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 335 PM EDT TUE AUG 18 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
FROM NRN HUDSON BAY INTO THE NRN PLAINS RESULTING IN A WSW FLOW INTO
THE NRN GREAT LAKES. A LINGERNIG AREA OF 700 MB FGEN AND WEAK
WAA/ISENTROPIC LIFT CONTINUES TO SUPPORT A PERSISTENT CLUSTER OF
SHOWERS OVER SCNTRL UPPER MI INTO EARLY AFTERNOON. UPSTREAM A
VIGOROUS SHRTWV ROTATING OVER SD/NE WILL LIFT TOWARD THE UPPER GREAT
LAKES TONIGHT BRINGING SHRA TO UPPER MI MAINLY TONIGHT INTO EARLY
WED. AT THE SFC...A WEAK FRONTAL BOUNDARY EXTENDED FROM CNTRL IA
THROUGH CNTRAL WI INTO CNTRL LWR MI. WITH HIGH PRES OVER NRN
ONTARIO...LIGHT NE WINDS PREVAILED ACROSS THE NRN LAKES TODAY.
TONIGHT...ATTENTION TURNS TO THE DEVELOPING UNSEASONABLY STRONG LOW
PRES SYSTEM MOVING OUT OF THE PLAINS. THE SD/NE SHRTWV WILL SUPPORT
A DEEPENING LOW MOVING INTO SRN MN BY 00Z/WED AND THEN INTO NRN
WI/SW U.P. BY 12Z/WED AS THE CENTRAL PRESSURE LOWERS NEAR 995 MB
APPROACHING RECORD LEVELS FOR THIS TIME OF YEAR. STRONG MOISTURE
TRANSPORT AND 305K-310K ISENTROPIC ASCENT WILL BRING AN AREA OF RAIN
THROUGH UPPER MI TONIGHT...MAINLY AFTER MIDNIGHT. HOWEVER...THIS
TRANSIENT BAND IS EXPECTED TO BRING QPF AMOUNTS OF ONLY 0.25-0.40
INCHES OVER THE CNTRL AND ERN CWA. THE FAR WEST HAS THE POTENTIAL TO
GET HIGHER AMOUNTS (0.5 TO ONE INCH) CLOSER TO THE STRONGEST DEEP
LAYER QVECTOR CONV AND LIFT WHICH WILL REMAIN TO THE WEST OVER NRN MN
AND WRN LAKE SUPERIOR. WITH MODEST MUCAPE VALUES INTO THE 200- 500
J/KG RANGE ONLY ISOLD TSRA ARE EXPECTED.
WEDNESDAY...SHOWERS WILL BE EXITING N AND E WED MORNING AHEAD OF THE
COLD FRONT AND THEN THE DRY SLOT WITH THE SYSTEM WILL MOVE IN FROM
THE SW WED LATE MORNING/AFTERNOON. ALTHOUGH THERE WILL BE STRONG 0-6
KM SHEAR ALONG THE FRONTAL BOUNDARY...AMOUNT OF INSTABILITY (MODELS
PROJECT 300-600 J/KG) REMAINS IN QUESTION AS THERE COULD BE
CONSIDERABLE CLOUD COVER LINGERING OVER THE AREA. BUT IF SUFFICIENT
INSTABILITY DEVELOPS AHEAD/ALONG THE FRONT...THERE COULD BE SOME
STRONG TO POSSIBLY SEVERE STORMS FORMING OVER MAINLY THE CENTRAL AND
ERN CWA IN THE MORNING. AFTER THE DRY SLOT MOVES INTO MAINLY THE
CENTRAL AND ERN CWA EXPECT SHRA TO GENERALLY DISSIPATE IN THE
AFTERNOON. WRAP AROUND PRECIP/MOISTURE WITH SYSTEM COULD MOVE INTO
WRN UPPER MI LATE IN THE DAY. WED LOOKS WINDY OVER CENTRAL AND ERN
UPPER MI WITH S-SW WINDS GUSTING TO 25-30 MPH.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 251 PM EDT TUE AUG 18 2015
THE ANOMALOUS UPPER TROUGH AND SURFACE LOW (AROUND 3-4 SIGMA) WILL
BE CENTERED BETWEEN DULUTH AND ISLE ROYALE AT THE START OF THE LONG
TERM FORECAST. THESE FEATURES WILL BE SLOWLY LIFTING TO THE
NORTHEAST THROUGH THURSDAY...BRINGING THE POTENTIAL FOR RAIN
SHOWERS AND BREEZY CONDITIONS TO THE AREA DURING THAT PERIOD.
STARTING OFF THE PERIOD...THE MID LEVEL DRY SLOT WILL BE OVER THE
CENTRAL AND EASTERN U.P. AND DON/T EXPECT MUCH MORE THAN LOW CLOUDS
FOR THE EVENING. BUT OVER THE WEST...WRAP AROUND MOISTURE WILL LEAD
TO SCATTERED/NUMEROUS SHOWERS WILL BE OCCURRING AND WILL LIKELY SEE
SOME ASSISTANCE FROM TERRAIN ENHANCEMENT WITH THE WEST-NORTHWEST
WINDS BEHIND THE SURFACE TROUGH THAT WILL BE LOCATED OVER THE
CENTRAL U.P. AT 06Z THURSDAY. AS THAT LOW LIFTS TO THE NORTHEAST
OVERNIGHT WEDNESDAY INTO THURSDAY...EXPECT THE SHOWERS TO SHIFT
EASTWARD BEHIND THE TROUGH AND MOVE OVER THE CENTRAL/EASTERN U.P.
ACCUMULATIONS WILL BE LIGHTER THAN OVER THE WEST WITH LESS TERRAIN
INFLUENCE...BUT SHOULD STILL SEE A FEW HUNDREDTHS BY LATE THURSDAY
AFTERNOON. WITH THE UPPER LOW QUICKLY MOVING TO THE NORTH THURSDAY
AFTERNOON INTO THURSDAY NIGHT...SHOULD SEE THE SHOWER COVERAGE
QUICKLY DIMINISH AS DRIER AIR ASSOCIATED WITH A SURFACE RIDGE MOVING
NORTHEAST INTO THE AREA. HAVE FOLLOWED THAT IDEA BOTH WITH THE POPS
AND CLOUD COVER THURSDAY AFTERNOON AND EVENING. IN FACT...SOME OF
THE AREAS NEAR THE WISCONSIN BORDER MAY HAVE THE LOW CLOUDS SCATTER
OUT BY EARLY AFTERNOON. IN ADDITION TO THE RAIN...EXPECT WINDS TO
INCREASE OVER AT LEAST THE WESTERN HALF OF THE CWA ON WEDNESDAY
NIGHT. THE DIFFERENCES IN THE MODELS LEADS TO SOME UNCERTAINTY IN
THE STRENGTH...BUT IT STILL APPEARS THAT GUSTS UP TO 30KTS ARE
POSSIBLE OVER THE KEWEENAW. FOR THE REST OF THE AREA...EXPECT GUSTS
IN THE 20-25KT RANGE ON THURSDAY.
THE HIGH PRESSURE RIDGE WILL BE NEAR THE AREA (FROM A HIGH IN THE
OHIO RIVER VALLEY) THROUGH FRIDAY NIGHT...BUT EXPECT THE GRADIENT
TO TIGHTEN THROUGH THAT PERIOD AS ANOTHER LOW DEVELOPS IN THE
NORTHERN PLAINS. THAT GRADIENT AND PLENTY OF SUNSHINE SHOULD LEAD TO
DECENT MIXING ON FRIDAY (AROUND 800MB)...RAISING TEMPERATURES TO
NORMAL OR SLIGHTLY ABOVE NORMAL VALUES UNDER OCCASIONALLY GUSTY
SOUTHWESTERLY WINDS (17-23KTS). WITH THE UPPER TROUGH AND SURFACE
LOW STILL NEAR THE NORTHERN PLAINS AND MOVING INTO THE UPPER
MISSISSIPPI VALLEY...EXPECT A SIMILAR DAY ON SATURDAY. HAVE REMOVED
THE POPS OVER THE WEST FOR SATURDAY AND WILL KEEP SKIES MOSTLY
SUNNY. SINCE THE TIGHTENING GRADIENT WILL REMAIN IN PLACE AHEAD OF
THE LOW...EXPECT WINDS TO BE A LITTLE GUSTIER THAN FRIDAY (UP TO
25KTS) AND TEMPERATURES TO BE A FEW DEGREES WARMER.
THE UPPER TROUGH FOR THE SECOND HALF OF THE WEEKEND
WILL MOVE THROUGH THE UPPER GREAT LAKES REGION OVERNIGHT SATURDAY
THROUGH SUNDAY EVENING. MEANWHILE...THE SURFACE LOW WILL LIFT
NORTH-NORTHEAST FROM NORTHWEST MINNESOTA TO FAR NORTHERN ONTARIO.
THIS WILL LEAD TO A SHARP COLD FRONT MOVING EAST ACROSS THE AREA ON
SUNDAY. MODELS SEEM TO BE FOCUSING ON LATE SATURDAY NIGHT AND
SUNDAY MORNING FOR THE FRONT TO MOVE THROUGH AND WILL FOCUS THE
HIGHEST POPS DURING THAT PERIOD (LOW LIKELY) AND QUICKLY RAMP
UP/DOWN ON BOTH SIDES. MODELS NOT SHOWING A WHOLE LOT OF INSTABILITY
AHEAD OF THE FRONT (MUCAPE VALUES ONLY UP TO 500 J/KG)...SO THINK
THAT THE THUNDER THREAT WILL BE LIMITED AND WILL CAP AT CHANCES.
THE COLD FRONT WILL USHER IN ANOTHER PERIOD OF BELOW NORMAL
TEMPERATURES FOR THE START OF NEXT WEEK AS HIGH PRESSURE BUILDS
OVER THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 122 AM EDT WED AUG 19 2015
UNUSUALLY DEEP LOW PRES FOR AUG WILL MOVE FROM SW MN TO NCNTRL LAKE
SUPERIOR DURING THIS FCST PERIOD. ABUNDANT MOISTURE AND SHRA
STREAMING N WITH THIS SYSTEM WILL LEAD TO LIFR CONDITIONS AT
KIWD/KCMX/KSAW OVERNIGHT AHEAD OF WARM FRONT LIFTING N. PASSAGE OF
WARM FRONT/OCCLUDING FRONT WILL THEN BRING IMPROVING CONDITIONS THIS
MORNING/EARLY AFTN. FARTHEST FROM SFC LOW...KSAW WILL SEE BETTER
DRYING AND POTENTIAL FOR IMPROVEMENT TO VFR IN THE AFTN. KCMX MAY
BRIEFLY REACH VFR...BUT MVFR IS MORE LIKELY TO PREVAIL THRU THE
AFTN. KIWD WILL REMAIN MVFR. THERE IS SOME POTENTIAL FOR ISOLD TSTMS
THIS AFTN IN NW AND CNTRL UPPER MI...BUT WITH CONSIDERABLE
UNCERTAINTY IN WHERE TSTMS WILL DEVELOP IF THEY DO...NO TS MENTION
WAS INCLUDED IN FCST. WINDS WILL BECOME GUSTY AFTER FROPA...
ESPECIALLY AT KSAW WHERE GUSTS TO AROUND 25KT ARE EXPECTED.
CONDITIONS WILL DETERIORATE AGAIN THIS EVENING AS LOW-LEVEL MOISTURE
WRAPS BACK INTO THE AREA AFTER THE LOW PASSES. KIWD SHOULD FALL TO
LIFR...KCMX TO IFR AND KSAW TO MVFR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 327 PM EDT TUE AUG 18 2015
AS LOW PRES ORGANIZES AND STRENGTHENS OVER THE PLAINS THIS EVENING
...NE WINDS WILL BEGIN TO INCREASE...ESPECIALLY OVER WRN LAKE
SUPERIOR WHERE GUSTS SHOULD REACH 30KT LATE AFTN/EARLY EVENING. MAY
EVEN BE A FEW GALE GUSTS NEAR APOSTLE ISLANDS EARLY EVENING. THIS
LOW WILL BECOME UNSEASONABLY DEEP FOR AUG AS IT LIFTS ACROSS WRN
LAKE SUPERIOR WED AFTERNOON. 20-30KT WINDS ARE EXPECTED OVER MUCH OF
THE LAKE TONIGHT INTO WED. MAY SEE GALE FORCE GUSTS OVER FAR WRN
LAKE SUPERIOR IN THE NE WINDS AHEAD OF THE LOW TONIGHT AND THEN IN
THE WESTERLY WINDS ACROSS WRN AND CENTRAL LAKE SUPERIOR ON THU AS
THE LOW LIFTS N OF THE AREA. WINDS WILL DIMINISH TO UNDER 20KT BY
FRI...AND THEN BEGIN TO INCREASE SOME AGAIN ON SAT AHEAD OF THE NEXT
COLD FRONT MOVING OUT ACROSS THE PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS DULUTH MN
642 PM CDT THU AUG 20 2015
.UPDATE...
ISSUED AT 636 PM CDT THU AUG 20 2015
UPDATED AVIATION SECTION BELOW. CLOUD COVER FORECAST IS CURRENTLY
ON TRACK AND EXPECT TO LOSE A LOT OF THE REMAINING CLOUD COVER
BETWEEN NOW AND 02Z...SETTING US UP FOR A FAIRLY GOOD RADIATIONAL
COOLING NIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 330 PM CDT THU AUG 20 2015
SHOWERS/DRIZZLE ENDING ACROSS THE ARROWHEAD EARLY THIS AFTERNOON
GIVING WAY TO SUNNY AND JUST BELOW SEASONABLE TEMPERATURES ACROSS
THE REGION. CLEAR SKIES AND NEAR-CALM WIND TONIGHT WITH A HIGH
PRESSURE BUILDING IN WILL LEAD TO COOL OVERNIGHT LOWS. SUNNY
AND WARMER ON FRIDAY WITH HIGHS NEAR 80.
ON THE SYNOPTIC SCALE THE BROAD LOW PRESSURE SYSTEM THAT BROUGHT
INTENSE RAINFALL TO THE REGION EARLIER THIS WEEK IS FINALLY
DEPARTING TO THE NORTHEAST. BEHIND THIS SOME LOW-LEVEL RIDGING WILL
BUILD IN TO THE UPPER MIDWEST AS A HIGH PRESSURE BUILDS FROM THE
TENNESSEE TO OHIO RIVER VALLEY. WARM AIR ADVECTION WILL RAMP UP DUE
TO WEST/SOUTHWESTERLY WINDS AT LOW LEVELS TONIGHT INTO TOMORROW. IN
ADDITION...A WEAK WARM FRONT ON THE LEADING EDGE OF THE WARM AIR
ADVECTION WILL MOVE ACROSS MANITOBA INTO NORTHWEST ONTARIO...WHICH
MAY GRAZE THE BORDERLAND WITH SOME SHOWERS OVERNIGHT. WHILE THERE IS
NOT MUCH SUPPORT FROM THE GLOBAL MODEL SUITE AS FAR AS QPF
GOES...MOST MODELS INDICATE THE NECESSARY FORCING WILL BE THERE FOR
A FEW SHOWERS. THE LATEST HRRR RUNS ARE ALSO SUPPORTIVE OF THIS
IDEA...SO INCLUDED SOME LOW POPS UP ALONG THE INTERNATIONAL FALLS
REGION. ON FRIDAY THE LOW-LEVEL RIDGING FLATTENS OUT WITH WEST-
SOUTHWEST FLOW ALOFT RESULTING IN CONTINUED WARM AIR ADVECTION. FOR
REFERENCE...THE 850MB TEMP FROM THIS MORNINGS 12Z SOUNDING AT
INTERNATIONAL FALLS WAS 3.1C...AND THE MODEL CONSENSUS IS FOR THIS
TO RISE TO ABOUT 18C BY FRIDAY AFTERNOON.
TONIGHT...GRADUALLY CLEARING SKIES WITH PATCHY FOG POSSIBLE. WINDS
BECOMING NEAR-CALM IN THE EVENING WHICH SHOULD ALLOW FOR FOG TO
DEVELOP...ESPECIALLY IN NORTHWEST WISCONSIN WHERE THE HEAVIEST
RAINFALL HAS FALLEN OVER THE PAST FEW DAYS. GUIDANCE NOT VERY
SUPPORTIVE OF THE FOG IDEA WHICH IS PROBABLY DUE TO THE DRIER AIR
MOVING IN FROM THE WEST...BUT WITH A WEAK RIDGE OVER THE REGION
TEMPS WILL FALL RAPIDLY AND AT LEAST PATCHY RADIATION FOG SHOULD
DEVELOP. LATER IN THE NIGHT...AFTER MIDNIGHT...SOME HIGH CLOUDS MAY
MOVE IN ACROSS FAR NORTH-CENTRAL MINNESOTA...AND POSSIBLY A SHOWER
OR TWO IN THE INTERNATIONAL FALLS REGION. FOG MAY DISSIPATE BEFORE
SUNRISE IF WINDS PICK UP BY EARLY FRIDAY MORNING...THIS WILL DEPEND
ON THE TIMING OF THE RIDGE AXIS BUT THINKING BY SUNRISE FOG SHOULD
BE GONE EVERYWHERE EXCEPT FOR NORTHERN WISCONSIN NEAR THE UP. LOWS
IN THE LOW/MID 40S TO LOW 50S.
FRIDAY...MOSTLY SUNNY...WARM...AND BREEZY. WINDS OUT OF THE SOUTH AT
10 TO 15 MPH WITH GUSTS TO NEAR 25 MPH. THERE MAY BE AN ISOLATED
SHOWER IN THE MORNING ACROSS THE BORDERLAND...BUT OTHERWISE DRY.
HIGHS IN THE UPPER 70S TO LOW 80S.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 330 PM CDT THU AUG 20 2015
THE MAIN CONCERN FOR THE EXTENDED IS THE THREAT FOR SEVERE WEATHER
SATURDAY AFTERNOON AND NIGHT.
THE SOUTHERLY FLOW CONTINUES ACROSS THE FORECAST AREA FRIDAY NIGHT
OUT AHEAD OF THE SYSTEM. THE NAM AND ECMWF ARE SIMILAR WITH TAKING
THE CENTER ACROSS NORTHERN MN WITH THE GFS KEEPING NORTH OF THE
INTERNATIONAL BORDER. BASED ON CURRENT TRENDS AND PERFORMANCE OF
THE MODELS WITH THE LAST STORM...WILL GO WITH A MIXTURE OF NAM/ECMWF
FOR SOLUTION. THE COLD FRONT WILL ENTER WESTERN LATE SATURDAY
MORNING AND ACROSS THE TWIN PORTS LATE SATURDAY EVENING.
THUNDERSTORMS WILL DEVELOP SATURDAY MORNING IN WRN MN AND MOVE EAST
DURING THE DAY. SPC DAY 3 OUTLOOK INDICATES A SLIGHT RISK MAINLY
EAST OF HIGHWAY 53/I-35 IN MN WITH MARGINAL RISK ACROSS MOST OF THE
REST OF THE FORECAST AREA. AS INDICATED BY THE MID SHIFT...THERE
WILL BE A RISK FOR SEVERE THUNDERSTORMS IN THE AFTERNOON BUT MAY BE
FOCUSED FURTHER WEST IN MN. IT STILL LOOKS LIKE A MCS MAY DEVELOP
LATER IN THE AFTERNOON. IT WILL BE ANOTHER HEAVY RAIN EVENT WITH
PWATS IN THE 1.5 TO 2.0 INCHES EXPECTED ACROSS THE FORECAST AREA.
STORM TOTAL QPF FORECAST IS FOR 1-1.5 INCHES FROM INL TO BRD WITH
0.50 TO 0.75 INCHES FURTHER EAST BY SUNDAY MORNING.
SIMILAR TO THE PAST SYSTEM...MUCH COOLER AIR WILL PUSH INTO THE
REGION WITH SOME SHOWERS ON SUNDAY. HIGHS WILL BE IN THE 60S INTO
THE MIDDLE OF THE WEEK WITH 45-55 AT NIGHT. A SHORTWAVE WILL PASS
THROUGH THE REGION ON THURSDAY BRINGING A POSSIBILITY OF A
THUNDERSTORM.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 636 PM CDT THU AUG 20 2015
SURFACE RIDGE OF HIGH PRESSURE BUILDING ACROSS THE AREA THIS
EVENING...THEN SOUTHWEST RETURN FLOW TO SET UP FOR TOMORROW.
CURRECT CUMULUS CLOUDS TO DISSIPATE BY 02Z THIS EVENING LEAVING
VFR CONDITIONS WITH DIMINISHING WINDS. FOG POSSIBLE AT TERMINALS
AFTER RECENT RAINFALL...SO HAVE PUT IN SOME IFR VISIBILITIES IN
TEMPO GROUPS FOR NOW. WILL RE-EVALUATE HERE FOR THE 06Z SET AND
CAN PUT A BIT MORE CERTAINTY IN THEN. FOG TO DISSIPATE IN THE
11-14Z TIME RANGE AND RETURN TO VFR CONDITIONS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 51 78 62 79 / 0 0 20 40
INL 47 82 60 80 / 20 20 20 70
BRD 52 82 64 81 / 0 0 20 70
HYR 48 79 62 81 / 0 10 10 10
ASX 47 80 61 84 / 0 0 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
UPDATE...LE
SHORT TERM...JJM
LONG TERM...STEWART
AVIATION...LE
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
1121 PM CDT TUE AUG 18 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 258 PM CDT TUE AUG 18 2015
VERY POWERFUL LOW PRESSURE MOVING FROM SOUTHWEST MN TO THE ARROWHEAD
REGION BY WEDNESDAY EVENING. IT IS VERY RARE TO SEE SUCH A STRONG
LOW PRESSURE SYSTEM IN THE SUMMER. IN FACT IT MAY WELL RIVAL THE LOW
PRESSURE RECORD FOR MSP. THE HRRR AND HOPWRF ARE IN GOOD AGREEMENT
AND HAVE DONE WELL THE LAST FEW HOURS. RADAR AND OBS SUPPORT THE
IDEA OF LESS PRECIPITATION IN TERMS OF AMOUNTS AND LESS CHANCES FOR
THUNDER AFTER 02Z THIS EVENING ACROSS THE AREA. DRY SLOT REALLY TOOK
OVER FOR THIS EVENT IN SRN MN. EXPECT THE COMMA HEAD WRAP-AROUND
PRECIPITATION TO AFFECT WESTERN MN LATE THIS AFTERNOON AND SLOWLY
LIFT EAST AND NORTH THROUGH THE EVENING AND OVERNIGHT HOURS. MAIN
PRECIPITATION WILL BE OVER WRN MN AND EXTENDING TO THE ARROWHEAD. WE
CAN EXPECT SCATTERED RAIN AND AN ISOLATED SHOWER OVER CENTRAL MN
INTO WRN WI THROUGH THE OVERNIGHT HOURS...MAYBE DRIZZLE. RAIN SHOULD
DIMINISH TOWARD MORNING AND THEN SEE AN INCREASE BY MID DAY.
STRONG WINDS WILL MOVE IN OVERNIGHT WITH GUSTS INTO THE MID 30 MPH
RANGE WEDNESDAY AFTERNOON WITH MOSTLY CLOUDY SKIES AND COOL
TEMPERATURES. VERY MUCH LIKE OCTOBER.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 258 PM CDT TUE AUG 18 2015
PICKING UP THE FORECAST WEDNESDAY NIGHT...THE FOCUS REMAINS GETTING
THIS INCREDIBLY STRONG MID AUGUST SYNOPTIC SCALE STORM SYSTEM OUT OF
HERE. BY THIS POINT...THE SURFACE LOW SHOULD BE POSITIONED OVER
WESTERN LAKE SUPERIOR AND SLIDING NORTHEAST. IT WILL BE ESSENTIALLY
VERTICALLY STACKED AND BEGIN WEAKENING OVERNIGHT. THE HIGHLY
AMPLIFIED 500MB TROUGH WILL INTRODUCE DRY NORTHWESTERLY FLOW INTO
WESTERN MN WHICH WILL EXPAND EASTWARD BY THURSDAY MORNING. DRY AIR
WILL ACCOMPANY THE NORTHWESTERLY FLOW...SO WE`LL SEE THE CLOUDS
BEGIN TO CLEAR FROM WEST TO EAST OVERNIGHT IN WESTERN MN...THROUGH
WESTERN WI BY MIDDAY THURSDAY. WITH CLEARING SKIES...AND THE LOW
MOVING OFF...WE`LL SEE TEMPERATURES REBOUND INTO THE MID 70S FOR
HIGHS. WESTERLY WINDS AT THE SURFACE OF 10-15 MPH ARE EXPECTED
THURSDAY...SO MUCH LESS WINDY THAN WEDNESDAY.
BY FRIDAY...A LOW PRESSURE SYSTEM WILL BE DEVELOPING NEAR
MONTANA...AND WE WILL BE ON THE BACK SIDE OF THE SURFACE RIDGE AXIS
ASSOCIATED WITH A SURFACE HIGH SLIDING EAST FROM THE CENTRAL PLAINS
TOWARD THE OHIO RIVER VALLEY....WHICH MEANS AN INCREASE IN SOUTHERLY
WINDS IS EXPECTED. WIND SPEEDS ARE FORECAST TO BE AROUND 15-20 MPH
WITH GUSTS OVER 20...AND TEMPERATURES WILL WARM INTO THE LOW 80S
ONCE AGAIN. MAYBE MORE NOTICEABLY...WILL BE THE DEW POINTS RISING
INTO THE MID 60S BY FRIDAY AFTERNOON.
FOR THE WEEKEND...THE AFOREMENTIONED SYSTEM IN MONTANA WILL BE THE
FEATURE OF CONCERN. THE SURFACE LOW IS EXPECTED TO PROGRESS
EASTWARD ALONG THE INTERNATIONAL BORDER SATURDAY THROUGH
SUNDAY...BUT A NORTH-SOUTH ORIENTED COLD FRONT WILL BE THE FOCUS FOR
SHOWER AND THUNDERSTORM ACTIVITY TO DEVELOP IN OUR AREA...MOST
LIKELY SATURDAY AFTERNOON THROUGH THE OVERNIGHT HOURS. THIS SHOULD
BE A PROGRESSIVE LINE OF THUNDERSTORMS ALONG THE BOUNDARY...SO BY
SUNDAY MORNING WE SHOULD BE BACK IN DRIER NORTHWESTERLY FLOW AND
COOLER TEMPERATURES. WILL HAVE TO SEE HOW THIS SYSTEM DEVELOPS IN
THE FUTURE MODEL GUIDANCE AS TIMING ISSUES ARE QUITE COMMON THIS
FAR OUT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1120 PM CDT TUE AUG 18 2015
THE LOW PRESSURE IS CENTERED NEAR RWF WITH A WARM FRONT EXTENDING
TO MSP/RNH/EAU. SOUTH OF THE FRONT...CONDITIONS ARE MAINLY VFR BUT
MVFR/IFR CIGS ARE BEGINNING TO DEVELOP IN POCKETS OF SWRN WI AND
SERN MN. FOUR OF THE SIX TAF LOCATIONS ARE NEAR THE WARM FRONT
WHICH LEADS TO A LOW CONFIDENCE FORECAST FOR MUCH OF THE NIGHT AS
THE WARM FRONT LINGERS NEARBY. EVENTUALLY THE LOW WILL TRACK
THROUGH AND MOISTURE ON ITS BACKSIDE WILL BRING CIGS INTO THE
MVFR/IFR RANGE INTO MUCH OF WEDNESDAY.
KMSP...CONDITIONS HAVE RANGED FROM IFR AND NEARLY LIFR NORTH OF
THE FRONT TO VFR WITH THE PASSAGE OF THE WARM FRONT. DON/T
BELIEVE THE FRONT WILL GO TOO FAR WHICH WILL RESULT IN HIGHLY
VARIABLE CONDITIONS TONIGHT. PREVAILING VFR WITH INSTANCES OF IFR
EXPECTED...BEFORE MVFR/IFR CONDITIONS TAKE HOLD BEGINNING LATE
TONIGHT.
/OUTLOOK FOR KMSP/
THU...VFR. WINDS W 10-15 KTS.
FRI...VFR. WINDS S 10-15 KTS.
SAT...VFR WITH MVFR/TSRA POSSIBLE LATE. WIND S AT 15G20 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...DRL
LONG TERM...SPD
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
402 PM CDT WED AUG 19 2015
.SHORT TERM...(This Evening through Friday Night)
Issued at 400 PM CDT WED AUG 19 2015
Can`t beat this weather...October in mid August. Better enjoy it
while it lasts.
Deep upper trough extending from MN through eastern KS into OK will
continue tracking east tonight. Water vapor imagery shows a weak
vorticity max dropping down the back side of the trough across
western IA. Widely scattered instability showers have popped as a
result. HRRR trend supports low-end slight chance PoPs over northern
MO until about sunset. Most likely only sprinkles. Otherwise,
heating based stratocu cloud cover from NE into the CWA should
dissipate with loss of daytime heating and leave skies cloud free by
midnight. Could be flirting with record lows tomorrow morning. MCI
record min is 53 and STJ is 48.
Temperatures will rebound, but remain below average on Thursday,
before returning closer to seasonal on Friday. Warming will be the
result of the cooler/drier air being pulled away as the upper trough
moves east vs return flow from a retreating surface high. But even
the warm-up will be pleasant by summer standards as dewpoints will
remain in the 50s on Thursday and only increase into the lower 60s
on Saturday. Sure beats the upper 60s to lower 70s which occur so
often this time of year.
Will leave the forecast rain-free through Friday except for a token
slight chance PoP over far northwest MO late Thursday night.
Rain chances begin to ramp up late Friday night into Saturday
morning as stronger isentropic ascent tied to increasing low-level
moisture and development of the nocturnal low-level jet.
.LONG TERM...(Saturday through Wednesday)
Issued at 400 PM CDT WED AUG 19 2015
The GFS, European, and Canadian models are all in good agreement
that this weekend will see a pattern very similar to the pattern
that moved through the area the past couple days. The models depict
an upper level trough will develop and slide east over the northern
states through the weekend. An associated cold front will advance
across the Central Plains ahead of the trough. The models show the
best chance for storms will be Saturday night into Sunday as the
upper level trough moves over the Dakotas and the cold front moves
through the forecast area. Initially, convection will occur across
MN and IA earlier Saturday evening before spreading further south
into the forecast area as the cold front interacts with increasing
moisture ahead of and along the front. Severe potential would be
limited if showers or cloud cover linger throughout the day on
Saturday as these could restrict surface heating and convection
later in the evening. Just like today, showers could linger on
Sunday morning after the passage of the cold front. Also,
temperatures will be lower than normal for August on Sunday into
Monday, and dry conditions will prevail after the lingering showers
dissipate on Sunday. Temperatures gradually increase throughout the
early part of the work week as upper level high pressure slowly
builds over the Plains.
&&
.AVIATION...(For the 18Z TAFS through 18Z Thursday Afternoon)
Issued at 1242 PM CDT WED AUG 19 2015
A few light showers/sprinkles possible over parts of west
central/central MO this afternoon as well as north central and
northeast MO. Otherwise, VFR conditions expected except at KSTJ where
local effects due to temperature spread between river water and air
should result in generation of steam fog. Could see brief periods of
LIFR visibilities/ceilings during the pre-dawn hours.
&&
.CLIMATE...
Issued at 400 PM CDT WED AUG 19 2015
Record low temperature/date for August 19th...
Kansas City (MCI) 53/1950
St. Joseph (STJ) 48/1981
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...MJ
LONG TERM...HEC
AVIATION...MJ CLIMATE...MJ
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1216 PM CDT WED AUG 19 2015
.UPDATE:
ISSUED AT 829 AM CDT WED AUG 19 2015
NORTHWARD EXPANSION OF PRECIPITATION SHIELD HAS NOT MATERIALIZED
THIS MORNING AS PREVIOUSLY FORECAST. HAVE REMOVED THUNDER AS
CONVECTION IS NOW LIMITED TO ARKANSAS AND ITS THAT SOUTHWARD PUSH
ON THE LEADING EDGE THAT IS LIKELY RESPONSIBLE FOR THE DRIER
CONDITIONS ACROSS OUR AREA. STILL EXPECT THAT WE WILL SEE ISOLATED
TO SCATTERED SHOWERS DEVELOP THIS AFTERNOON AS THE SHORTWAVE MOVES
ACROSS THE AREA...BUT WIDESPREAD PRECIPITATION SHOULD BE LIMITED
TO SOUTHERN MISSOURI AND ILLINOIS.
CVKING
&&
.SHORT TERM: (THROUGH TONIGHT)
ISSUED AT 306 AM CDT WED AUG 19 2015
A STOUT COLD FRONT WAS SWEEPING THROUGH THE REGION EARLY THIS
MORNING. AT 08Z, THE FRONT STRETCHED FROM ITS PARENT CYCLONE OVER
SRN MN SEWD THROUGH ERN IA, THEN CURVED BACK SWWD THROUGH MO AND
INTO SERN KS AND NRN OK. WATER VAPOR IMAGERY AND RAP PV ANALYSES
DEPICT A SECONDARY VORT MAX DIVING INTO THE BASE OF THE TROUGH,
WHICH IS CONSISTENT WITH MODEL GUIDANCE. LARGE SCALE ASCENT AHEAD
OF THIS FEATURE WILL SUPPORT PERIODS OF SH/TS TODAY INTO TONIGHT.
PRECIPITATION SHOULD TAPER OFF TONIGHT IN THE WAKE OF THE
AFOREMENTIONED VORT MAX.
WED NIGHT/EARLY THU MORNING LOWS IN THE 50S WILL BE AROUND 10
DEGREES BELOW AVERAGE.
KANOFSKY
.LONG TERM: (THURSDAY THROUGH TUESDAY)
ISSUED AT 306 AM CDT WED AUG 19 2015
SURFACE HIGH PRESSURE BUILDS INTO THE SOUTHERN PLAINS ON THU AND
GRADUALLY SHIFTS EWD WITH TIME. THIS WILL KEEP COOLER/DRIER
CONDITIONS AND WESTERLY WINDS IN PLACE ACROSS MOST OF THE CWA ON
THU/FRI UNTIL THE SURFACE HIGH HAS SHIFTED FAR ENOUGH EAST FOR
WINDS TO TURN SLY AROUND ITS BACK SIDE. RETURN FLOW SETS UP
FARTHER WEST ACROSS THE PLAINS ON THU NIGHT/FRI AHEAD OF THE NEXT
LOW PRESSURE SYSTEM WHICH WILL BE CROSSING FROM THE PACIFIC NW
INTO THE PLAINS OVER THE WEEKEND. THIS SYSTEM WILL BRING THE NEXT
CHANCE FOR SH/TS TO THE LSX CWA OVER THE WEEKEND. ANOTHER STOUT
COLD FRONT IS EXPECTED TO MOVE ACROSS THE CWA ON SUN AND THEN
SETTLE SOUTH OF THE CWA EARLY NEXT WEEK. TEMPERATURES WILL DIP
BELOW AVERAGE AGAIN IN THE WAKE OF THIS FRONT.
KANOFSKY
&&
.AVIATION: (FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1215 PM CDT WED AUG 19 2015
EXPECT VFR CONDITIONS WITH ISOLATED TO SCATTERED SHOWERS THIS
AFTERNOON AS THE UPPER LEVEL TROF SWINGS ACROSS THE AREA. CLEARING
SKIES TONIGHT WITH WEST/NORTHWEST WIND CONTINUING.
SPECIFICS FOR KSTL:
EXPECT VFR CONDITIONS WITH A FEW SHOWERS THIS AFTERNOON.
CVKING
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
834 AM CDT WED AUG 19 2015
.UPDATE:
ISSUED AT 829 AM CDT WED AUG 19 2015
NORTHWARD EXPANSION OF PRECIPITATION SHIELD HAS NOT MATERIALIZED
THIS MORNING AS PREVIOUSLY FORECAST. HAVE REMOVED THUNDER AS
CONVECTION IS NOW LIMITED TO ARKANSAS AND ITS THAT SOUTHWARD PUSH
ON THE LEADING EDGE THAT IS LIKELY RESPONSIBLE FOR THE DRIER
CONDITIONS ACROSS OUR AREA. STILL EXPECT THAT WE WILL SEE ISOLATED
TO SCATTERED SHOWERS DEVELOP THIS AFTERNOON AS THE SHORTWAVE MOVES
ACROSS THE AREA...BUT WIDESPREAD PRECIPITATION SHOULD BE LIMITED
TO SOUTHERN MISSOURI AND ILLINOIS.
CVKING
&&
.SHORT TERM: (THROUGH TONIGHT)
ISSUED AT 306 AM CDT WED AUG 19 2015
A STOUT COLD FRONT WAS SWEEPING THROUGH THE REGION EARLY THIS
MORNING. AT 08Z, THE FRONT STRETCHED FROM ITS PARENT CYCLONE OVER
SRN MN SEWD THROUGH ERN IA, THEN CURVED BACK SWWD THROUGH MO AND
INTO SERN KS AND NRN OK. WATER VAPOR IMAGERY AND RAP PV ANALYSES
DEPICT A SECONDARY VORT MAX DIVING INTO THE BASE OF THE TROUGH,
WHICH IS CONSISTENT WITH MODEL GUIDANCE. LARGE SCALE ASCENT AHEAD
OF THIS FEATURE WILL SUPPORT PERIODS OF SH/TS TODAY INTO TONIGHT.
PRECIPITATION SHOULD TAPER OFF TONIGHT IN THE WAKE OF THE
AFOREMENTIONED VORT MAX.
WED NIGHT/EARLY THU MORNING LOWS IN THE 50S WILL BE AROUND 10
DEGREES BELOW AVERAGE.
KANOFSKY
.LONG TERM: (THURSDAY THROUGH TUESDAY)
ISSUED AT 306 AM CDT WED AUG 19 2015
SURFACE HIGH PRESSURE BUILDS INTO THE SOUTHERN PLAINS ON THU AND
GRADUALLY SHIFTS EWD WITH TIME. THIS WILL KEEP COOLER/DRIER
CONDITIONS AND WESTERLY WINDS IN PLACE ACROSS MOST OF THE CWA ON
THU/FRI UNTIL THE SURFACE HIGH HAS SHIFTED FAR ENOUGH EAST FOR
WINDS TO TURN SLY AROUND ITS BACK SIDE. RETURN FLOW SETS UP
FARTHER WEST ACROSS THE PLAINS ON THU NIGHT/FRI AHEAD OF THE NEXT
LOW PRESSURE SYSTEM WHICH WILL BE CROSSING FROM THE PACIFIC NW
INTO THE PLAINS OVER THE WEEKEND. THIS SYSTEM WILL BRING THE NEXT
CHANCE FOR SH/TS TO THE LSX CWA OVER THE WEEKEND. ANOTHER STOUT
COLD FRONT IS EXPECTED TO MOVE ACROSS THE CWA ON SUN AND THEN
SETTLE SOUTH OF THE CWA EARLY NEXT WEEK. TEMPERATURES WILL DIP
BELOW AVERAGE AGAIN IN THE WAKE OF THIS FRONT.
KANOFSKY
&&
.AVIATION: (FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 634 AM CDT WED AUG 19 2015
RAIN SHOWERS ACROSS SOUTHWEST MISSOURI WILL SPREAD NORTHEAST
DURING THE MORNING IMPACTING KCOU AND THE ST. LOUIS AREA
TERMINALS, WITH SHOWERS BECOMING MORE SPOTTY IN THE AFTERNOON.
FUTHER NORTH WE SHOULD SEE SCATTERED SHOWERS DEVELOP IN RESPONSE
TO HEATING AND THUS THE COVERAGE AND DIRECT IMPACT AT KUIN IS LESS
CERTAIN HENCE ONLY MENTIONED VCSH. FLIGHT CONDITIONS SHOULD BE IN
THE HIGH-END MVFR TO LOW-END VFR RANGE MUCH OF THE DAY WITH
CLEARING SKIES AREAWIDE BY EARLY THIS EVENING.
SPECIFICS FOR KSTL:
RAIN SHOWERS WILL SPREAD FROM SOUTHWEST MISSOURI INTO KSTL BY
MID-MORNING. SHOWERS SHOULD PERSIST THROUGH EARLY AFTERNOON AND
THEN BECOME MORE SPOTTY BY LATE AFTERNOON. EXPECT FLIGHT
CONDITIONS IN THE HIGH-END MVFR TO LOW-END VFR RANGE MUCH OF THE
DAY WITH CLEARING SKIES EARLY THIS EVENING.
GLASS
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
648 AM CDT WED AUG 19 2015
.SHORT TERM: (THROUGH TONIGHT)
ISSUED AT 306 AM CDT WED AUG 19 2015
A STOUT COLD FRONT WAS SWEEPING THROUGH THE REGION EARLY THIS
MORNING. AT 08Z, THE FRONT STRETCHED FROM ITS PARENT CYCLONE OVER
SRN MN SEWD THROUGH ERN IA, THEN CURVED BACK SWWD THROUGH MO AND
INTO SERN KS AND NRN OK. WATER VAPOR IMAGERY AND RAP PV ANALYSES
DEPICT A SECONDARY VORT MAX DIVING INTO THE BASE OF THE TROUGH,
WHICH IS CONSISTENT WITH MODEL GUIDANCE. LARGE SCALE ASCENT AHEAD
OF THIS FEATURE WILL SUPPORT PERIODS OF SH/TS TODAY INTO TONIGHT.
PRECIPITATION SHOULD TAPER OFF TONIGHT IN THE WAKE OF THE
AFOREMENTIONED VORT MAX.
WED NIGHT/EARLY THU MORNING LOWS IN THE 50S WILL BE AROUND 10
DEGREES BELOW AVERAGE.
KANOFSKY
.LONG TERM: (THURSDAY THROUGH TUESDAY)
ISSUED AT 306 AM CDT WED AUG 19 2015
SURFACE HIGH PRESSURE BUILDS INTO THE SOUTHERN PLAINS ON THU AND
GRADUALLY SHIFTS EWD WITH TIME. THIS WILL KEEP COOLER/DRIER
CONDITIONS AND WESTERLY WINDS IN PLACE ACROSS MOST OF THE CWA ON
THU/FRI UNTIL THE SURFACE HIGH HAS SHIFTED FAR ENOUGH EAST FOR
WINDS TO TURN SLY AROUND ITS BACK SIDE. RETURN FLOW SETS UP
FARTHER WEST ACROSS THE PLAINS ON THU NIGHT/FRI AHEAD OF THE NEXT
LOW PRESSURE SYSTEM WHICH WILL BE CROSSING FROM THE PACIFIC NW
INTO THE PLAINS OVER THE WEEKEND. THIS SYSTEM WILL BRING THE NEXT
CHANCE FOR SH/TS TO THE LSX CWA OVER THE WEEKEND. ANOTHER STOUT
COLD FRONT IS EXPECTED TO MOVE ACROSS THE CWA ON SUN AND THEN
SETTLE SOUTH OF THE CWA EARLY NEXT WEEK. TEMPERATURES WILL DIP
BELOW AVERAGE AGAIN IN THE WAKE OF THIS FRONT.
KANOFSKY
&&
.AVIATION: (FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 634 AM CDT WED AUG 19 2015
RAIN SHOWERS ACROSS SOUTHWEST MISSOURI WILL SPREAD NORTHEAST
DURING THE MORNING IMPACTING KCOU AND THE ST. LOUIS AREA
TERMINALS, WITH SHOWERS BECOMING MORE SPOTTY IN THE AFTERNOON.
FUTHER NORTH WE SHOULD SEE SCATTERED SHOWERS DEVELOP IN RESPONSE
TO HEATING AND THUS THE COVERAGE AND DIRECT IMPACT AT KUIN IS LESS
CERTAIN HENCE ONLY MENTIONED VCSH. FLIGHT CONDITIONS SHOULD BE IN
THE HIGH-END MVFR TO LOW-END VFR RANGE MUCH OF THE DAY WITH
CLEARING SKIES AREAWIDE BY EARLY THIS EVENING.
SPECIFICS FOR KSTL:
RAIN SHOWERS WILL SPREAD FROM SOUTHWEST MISSOURI INTO KSTL BY
MID-MORNING. SHOWERS SHOULD PERSIST THROUGH EARLY AFTERNOON AND
THEN BECOME MORE SPOTTY BY LATE AFTERNOON. EXPECT FLIGHT
CONDITIONS IN THE HIGH-END MVFR TO LOW-END VFR RANGE MUCH OF THE
DAY WITH CLEARING SKIES EARLY THIS EVENING.
GLASS
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
407 AM CDT WED AUG 19 2015
.SHORT TERM: (THROUGH TONIGHT)
ISSUED AT 306 AM CDT WED AUG 19 2015
A STOUT COLD FRONT WAS SWEEPING THROUGH THE REGION EARLY THIS
MORNING. AT 08Z, THE FRONT STRETCHED FROM ITS PARENT CYCLONE OVER
SRN MN SEWD THROUGH ERN IA, THEN CURVED BACK SWWD THROUGH MO AND
INTO SERN KS AND NRN OK. WATER VAPOR IMAGERY AND RAP PV ANALYSES
DEPICT A SECONDARY VORT MAX DIVING INTO THE BASE OF THE TROUGH,
WHICH IS CONSISTENT WITH MODEL GUIDANCE. LARGE SCALE ASCENT AHEAD
OF THIS FEATURE WILL SUPPORT PERIODS OF SH/TS TODAY INTO TONIGHT.
PRECIPITATION SHOULD TAPER OFF TONIGHT IN THE WAKE OF THE
AFOREMENTIONED VORT MAX.
WED NIGHT/EARLY THU MORNING LOWS IN THE 50S WILL BE AROUND 10
DEGREES BELOW AVERAGE.
KANOFSKY
.LONG TERM: (THURSDAY THROUGH TUESDAY)
ISSUED AT 306 AM CDT WED AUG 19 2015
SURFACE HIGH PRESSURE BUILDS INTO THE SOUTHERN PLAINS ON THU AND
GRADUALLY SHIFTS EWD WITH TIME. THIS WILL KEEP COOLER/DRIER
CONDITIONS AND WESTERLY WINDS IN PLACE ACROSS MOST OF THE CWA ON
THU/FRI UNTIL THE SURFACE HIGH HAS SHIFTED FAR ENOUGH EAST FOR
WINDS TO TURN SLY AROUND ITS BACK SIDE. RETURN FLOW SETS UP
FARTHER WEST ACROSS THE PLAINS ON THU NIGHT/FRI AHEAD OF THE NEXT
LOW PRESSURE SYSTEM WHICH WILL BE CROSSING FROM THE PACIFIC NW
INTO THE PLAINS OVER THE WEEKEND. THIS SYSTEM WILL BRING THE NEXT
CHANCE FOR SH/TS TO THE LSX CWA OVER THE WEEKEND. ANOTHER STOUT
COLD FRONT IS EXPECTED TO MOVE ACROSS THE CWA ON SUN AND THEN
SETTLE SOUTH OF THE CWA EARLY NEXT WEEK. TEMPERATURES WILL DIP
BELOW AVERAGE AGAIN IN THE WAKE OF THIS FRONT.
KANOFSKY
&&
.AVIATION: (FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1159 PM CDT TUE AUG 18 2015
COMPLEX OF THUNDERSTORMS OVER CENTRAL MISSOURI WILL MOVE INTO THE
ST. LOUIS METRO TAF SITES AROUND 06Z PRODUCING MVFR AND POSSIBLY
BRIEF IFR VISIBILITIES AS WELL AS GUSTY WINDS THROUGH 08Z BEFORE
THE THUNDERSTORMS MOVE OFF TO THE EAST. COLD FRONT WILL MOVE
THROUGH KUIN AND KCOU AROUND 09Z AND THE ST. LOUIS METRO TAF SITES
AROUND 12Z. CEILINGS WILL BE HIGH MVFR OR LOW VFR WITH THE PASSAGE
OF THE COLD FRONT INTO THE MORNING HOURS. EXPECT RAIN TO DEVELOP
DURING THE MORNING HOURS AT KCOU AND AT THE ST. LOUIS METRO TAF
SITES WITH SCATTERED SHOWERS AROUND QUINCY. RAIN SHOULD END BY
LATE IN THE DAY.
SPECIFICS FOR KSTL:
EXPECT THUNDERSTORMS WITH VISIBILITIES AS LOW AS IFR TO AFFECT
THE TERMINAL THROUGH 08Z. CEILINGS WILL BE LOW MVFR OR HIGH VFR
WITH THE PASSAGE OF A COLD FRONT AROUND 12Z. THEN RAIN WILL MOVE
INTO THE AREA BY MID MORNING AND LAST MOST OF THE DAY BEFORE
ENDING BY 00Z.
BRITT
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1200 AM CDT WED AUG 19 2015
.SHORT TERM: (THROUGH LATE TONIGHT)
ISSUED AT 355 PM CDT TUE AUG 18 2015
PREFRONTAL CONVECTION HAS BLOWN UP ABOUT AS EXPECTED THIS AFTERNOON.
SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL 900 PM THIS EVENING AND
WE`VE HAD SOME SPORADIC REPORTS OF TREE LIMBS DOWN WITH THE
STRONGEST STORMS. SBCAPE IN EXCESS OF 3000 J/KG INDICATED ON SPC
MESOANALYSIS PAGE AHEAD OF THE CONVECTION WITH A VIGOROUS SHORTWAVE
MOVING INTO WESTERN MISSOURI AT THIS TIME. MASS FIELDS ON SHORT-
RANGE GUIDANCE CONTINUE TO STREAM INSTABILITY UP INTO THE REGION
THROUGH THE EVENING...AND THIS LOOKS REASONABLE GIVEN THE POSITION
OF THE SHORTWAVE AND SURFACE FRONT. HAVE TO SAY, THE HRRR DID A
PRETTY GOOD JOB WITH THE CONVECTION THIS AFTERNOON, SO THE SHORT
RANGE FORECAST FOR TONIGHT IS BIASED HEAVILY TOWARD THE HRRR.
EXPECT STORMS CURRENTLY OVER EASTERN KANSAS TO CONTINUE TO DEVELOP
AND MOVE EASTWARD TONIGHT AHEAD OF THE SHORTWAVE. THERE WILL LIKELY
BE A LUL IN THE THUNDERSTORM ACTIVITY OVER OUR CWFA AFTER 00-02Z,
BUT THE STORMS CURRENTLY IN KANSAS WILL EVENTUALLY MOVE IN AFTER 04-
05Z. ADDITIONAL DEVELOPMENT IS ALSO POSSIBLE AHEAD OF THE KANSAS
STORMS. THE COLD FRONT WILL SWEEP INTO MISSOURI OVERNIGHT AND SHOULD
BE THROUGH CENTRAL AND INTO EASTERN MISSOURI BY 12Z.
CARNEY
.LONG TERM: (WEDNESDAY THROUGH NEXT TUESDAY)
ISSUED AT 355 PM CDT TUE AUG 18 2015
MODELS CONTINUE TO SUPPORT A FAST SURFACE FRONTAL SOLUTION WHILE
MAINTAINING A SIMILAR TIMING WITH THE UPPER LEVEL PROFILE. WHILE
THERE SHOULD STILL BE A NICE SLUG OF WIDESPREAD LIFT BUILDING IN
FROM LATE WEDNESDAY MORNING THRU EARLY EVENING...THE COLUMN WILL
BE VERY LIMITED THERMODYNAMICALLY...MEANING LIKE MOSTLY SHOWERS WITH
DIMINISHING CHANCES FOR THUNDER AS THE DAY GOES ALONG. DECENT RAIN
CHANCES ARE NOW EXPECTED TO LINGER INTO EARLY EVENING BEFORE THEN
MAKING A RAPID EXIT FROM SOUTHWEST TO NORTHEAST FOLLOWED QUICKLY BY
CLEARING SKIES.
WHAT WILL REMAIN IN ITS WAKE WILL BE A RARE COOL AND DRY PERIOD
BEGINNING LATE WEDNESDAY NIGHT THRU FRIDAY AFTERNOON WITH MIN TEMPS
DIPPING INTO THE 50S AND MAX TEMPS ONLY REACHING TO AROUND 80
DEGREES.
THE FRONTAL COMPLEX THAT HAD PUSHED TO OUR SOUTH ON WEDNESDAY
WILL THEN MOVE BACK TO THE NORTH BY SATURDAY TO ALLOW CHANCES FOR
THUNDERSTORMS TO RETURN AND PERSIST THRU THE WEEKEND WITH
TEMPERATURES BACK TO SEASONABLE AVERAGES.
IN YET ANOTHER SIGN THAT AUTUMN IS NOT TOO FAR OFF ANYMORE...ANOTHER
DECENTLY STRONG COLD FRONT PUSHES THRU LATE SUNDAY AND IS
EXPECTED TO BRING AN ENCORE OF THE COOL AND DRY PERIOD FOR MONDAY
AND TUESDAY OF NEXT WEEK.
SOME MODEL DISCREPANCIES THEN EXIST HEADING DEEPER INTO NEXT WEEK
BUT THE GENERAL THEME IS SUMMER THEN REMINDING US THAT IT IS NOT YET
DONE...WITH AN UPPER LEVEL RIDGE ATTEMPTING TO BUILD IN TO POSSIBLY
DELIVER ONE FINAL ROUND OF DANGEROUS HEAT AND HUMIDITY TO CLOSE OUT
AUGUST.
TES
&&
.AVIATION: (FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1159 PM CDT TUE AUG 18 2015
COMPLEX OF THUNDERSTORMS OVER CENTRAL MISSOURI WILL MOVE INTO THE
ST. LOUIS METRO TAF SITES AROUND 06Z PRODUCING MVFR AND POSSIBLY
BRIEF IFR VISIBILITIES AS WELL AS GUSTY WINDS THROUGH 08Z BEFORE
THE THUNDERSTORMS MOVE OFF TO THE EAST. COLD FRONT WILL MOVE
THROUGH KUIN AND KCOU AROUND 09Z AND THE ST. LOUIS METRO TAF SITES
AROUND 12Z. CEILINGS WILL BE HIGH MVFR OR LOW VFR WITH THE PASSAGE
OF THE COLD FRONT INTO THE MORNING HOURS. EXPECT RAIN TO DEVELOP
DURING THE MORNING HOURS AT KCOU AND AT THE ST. LOUIS METRO TAF
SITES WITH SCATTERED SHOWERS AROUND QUINCY. RAIN SHOULD END BY
LATE IN THE DAY.
SPECIFICS FOR KSTL:
EXPECT THUNDERSTORMS WITH VISIBILITIES AS LOW AS IFR TO AFFECT
THE TERMINAL THROUGH 08Z. CEILINGS WILL BE LOW MVFR OR HIGH VFR
WITH THE PASSAGE OF A COLD FRONT AROUND 12Z. THEN RAIN WILL MOVE
INTO THE AREA BY MID MORNING AND LAST MOST OF THE DAY BEFORE
ENDING BY 00Z.
BRITT
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
251 PM EDT WED AUG 19 2015
.SYNOPSIS...
UNSETTLED WEATHER WILL CONTINUE THROUGH THURSDAY. A WEAK COLD
FRONT WILL MOVE ACROSS THE AREA FRIDAY. LESS COVERAGE OF SHOWERS
AND THUNDERSTORMS CAN BE EXPECTED FRIDAY THROUGH EARLY NEXT WEEK
WITH TYPICAL LATE SUMMERTIME TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 300 PM WEDNESDAY...SCATTERED CONVECTION CONTINUES ACROSS MUCH OF
THE FORECAST AREA AND WILL CONTINUE THROUGH THE EVENING. WITH LARGE
SCALE FORCING MAINLY ABSENT THE BEST FOCUS FOR CONVECTION IS ALONG
THE OUTFLOW BOUNDARIES. SEVERAL AREAS ARE SEEING VERY HEAVY RAIN
WITH 1 TO 2 INCHES AN HOUR. THIS IS BEING HELPED BY A VERY
MOIST ATMOSPHERE WITH PRECIPITABLE WATER VALUES BETWEEN 2 AND 2.25
INCHES. THE 17 UTC RUN OF THE HRRR IS ECHOING THE 13 AND 16 UTC RUNS
OF THE HRRR WITH THE DIURNAL CONVECTION CONTINUING OVER MUCH OF THE
FORECAST AREA THROUGH 22 UTC THEN SLOWLY DISSIPATING BY SUNSET.
MAXIMUM TEMPERATURES ARE RUNNING IN THE MID TO UPPER 80S AND ARE
PEAKING FOR THE DAY. OVERNIGHT TEMPERATURES ARE EXPECTED TO DROP
INTO THE MIDDLE 70S INLAND AND THE UPPER 70S AT THE COAST.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...A MID LEVEL CYCLONE WILL MOVE ACROSS THE GREAT
LAKES WITH A BROAD ZONAL FLOW PUSHING A COLD FRONT ACROSS THE
AREA EARLY FRIDAY. BY THE END OF THE PERIOD MID LEVEL HIGH
PRESSURE BUILDS BACK IN FROM THE SOUTH WITH ANY APPRECIABLE
AFFECTS FROM THE FRONT BASICALLY GONE. FOR THURSDAY...WEAK SURFACE
TROUGHING WILL STILL RESIDE ACROSS THE AREA AND GOOD CHANCE POPS
REMAIN IN THE FORECAST. POPS DECREASE SOMEWHAT FOR FRIDAY AS THE
WEAK FRONT HAS A SIGNIFICANT SUBSIDENCE INVERSION IN THE 700-850MB
LAYER WHICH WILL MAKE CONVECTIVE DEVELOPMENT MORE CHALLENGING THAN
PREVIOUS DAYS. THERE REMAINS A VERY MOIST PROFILE HOWEVER AND
LOWER CHANCE POPS SHOULD BE A GOOD COMPROMISE. TEMPERATURES CHANGE
LITTLE THROUGH THE PERIOD WITH HIGHS IN THE 90S AND LOWS IN THE
70S.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 AM WEDNESDAY...COLD FRONT PUSHING OFFSHORE FIRST THING
SATURDAY WILL LEAVE CLEARING SKY CONDITIONS AND IMPROVING WEATHER
FOR THE WKND. WHILE THIS FASTER FROPA REPRESENTS A CHANGE IN THE
FORECAST...GUIDANCE IS IN GOOD AGREEMENT ATTM WITH A STRONG MID-
LEVEL PUSH...AND THE WKND IS LOOKING TO BE QUITE NICE LOCALLY NOW.
WEAK COOL ADVECTION BUT STRONG DRY ADVECTION WILL ERODE CLOUDS
SATURDAY...AND THEN LEAVE AMPLE SUNSHINE LATE SATURDAY AND ON
SUNDAY...AS PWATS DROP TO AROUND THE FIRST QUARTILE MOVING-AVERAGE
FOR LATE AUGUST. TEMPS THIS WKND WILL BE AROUND OR SLIGHTLY BELOW
CLIMO WITH N/NE WINDS...BUT OVERALL A PLEASANT WKND APPEARS TO BE
IN STORE. RETURN FLOW BEGINS TO REDEVELOP MONDAY WITH TEMPS
WARMING BACK TO SEASONABLE LEVELS OR SLIGHTLY ABOVE...BUT THIS
WILL BE ACCOMPANIED BY INCREASING PRECIP CHANCES AS WELL. GFS
DRIVES A POTENT SHORTWAVE OVERHEAD LATE MONDAY INTO TUESDAY...A
PIECE OF THE LONGER TROUGH TRAVERSING THE NORTHEAST...WHILE THE
ECMWF SHOWS NO SUCH FEATURE. FOR NOW WILL RAMP POP BACK UP TO
CLIMO VALUES FOR EARLY NEXT WEEK...MAINTAINING THE INHERITED
FORECAST
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
AS OF 18Z...EXPECT VFR FOR THE REST OF THE VALID TAF PERIOD WITH
ISOLATED TO SCATTERED SHRA/TSRA THIS AFTERNOON AND TONIGHT.
POTENTIAL FOR PATCHY MARGINAL MVFR FOG OVERNIGHT.
LATEST RADAR DEPICTS ISOLATED TO SCATTERED SHRA/TSRA DEVELOPING
ACROSS THE AREA. WHILE COULD SEE BRIEF PERIODS OF MVFR IN ANY HEAVY
DOWNPOURS...OVERALL EXPECT VFR THROUGH TONIGHT. SOUTHWEST WINDS WILL
INCREASE TO AOB 12 KTS THIS AFTERNOON...BECOMING LIGHT AND VARIABLE
TONIGHT. COULD SEE PATCHY AREAS OF MARGINAL MVFR FOG LATE
OVERNIGHT...THUS HAVE INTRODUCED TEMPO GROUP. AFTER DAYBREAK...VFR
WILL PREVAIL WITH SOUTHWEST WINDS.
EXTENDED OUTLOOK...SCATTERED CONVECTION IS EXPECTED THROUGH THE
PERIOD...MOST ACTIVE THURSDAY WITH BRIEF IFR CONDITIONS POSSIBLE.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM WEDNESDAY...SOUTH TO SOUTHWEST WINDS OF 10 TO 15 KNOTS
ARE BLOWING OVER THE WATERS WITH SEAS CONTINUING TO RUN BETWEEN 2
AND 3 FEET. THE FRYING PAN BUOY CONTINUES TO SHOWS A ESE SWELL OF
1.3 FEET WITH THE 2.3 FT WIND WAVE AND THESE CONDITIONS ARE
EXPECTED TO REMAIN THE SAME THROUGHOUT THE OVERNIGHT WITH THE ONLY
HAZARD WILL BE AN ISOLATED
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...THE PIEDMONT TROUGH WILL BECOME MORE A LITTLE
BETTER DEFINED THURSDAY AND WIND FIELDS WILL SHOULD RESPOND WITH A
SOUTHWEST FLOW OF 10-15 KNOTS...MOSTLY IN THE LOWER END OF THE
RANGE. A WEAK FRONT WILL PUSH ACROSS THE WATERS EARLY FRIDAY WITH
THE FRONT AND THE LAND BREEZE PROVIDING A BRIEF OFFSHORE FLOW. BY
LATER IN THE DAY LIGHT AND VARIABLE WINDS DEVELOP UNDER A WEAK
PRESSURE PATTERN. AS FOR SEAS...GENERALLY 2-3 FEET THROUGH THE
PERIOD.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 300 AM WEDNESDAY...COLD FRONT WILL BE SOUTH OF THE WATERS
SATURDAY MORNING...LEAVING NE WINDS IN ITS WAKE. THIS WIND
DIRECTION WILL PERSIST MUCH OF THE PERIOD...BUT A WEAKENING OF THE
FRONT WILL ALLOW RETURN FLOW AND SOUTHERLY WINDS TO REDEVELOP
LATE. SPEEDS FROM THE NE WILL BE 10-15 KTS...EASING AS THE WINDS
SHIFT AT THE END OF THE PERIOD. WAVE HEIGHTS WILL BE PRIMARILY
WIND-WAVE DRIVEN...BUT OF LOW AMPLITUDE AROUND 1-3 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SHK
NEAR TERM...DRH
SHORT TERM...SHK
LONG TERM...JDW
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
152 PM EDT WED AUG 19 2015
.SYNOPSIS...
UNSETTLED WEATHER WILL CONTINUE THROUGH MID WEEK AS TROPICAL
MOISTURE STREAMS INTO THE AREA AHEAD OF AN APPROACHING COLD
FRONT. THE FRONT WILL REACH THE COASTAL CAROLINAS BY FRIDAY AND
OFFSHORE OVER THE WEEKEND. ANOTHER COLD FRONT MAY APPROACH ON
TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM WEDNESDAY...SCATTERED CONVECTION HAS DEVELOPED
ACROSS MUCH OF THE THE AREA AND IS EXPECTED TO CONTINUE TO DEVELOP
ALONG OUTFLOWS AS LARGE SCALE FORCING IS NOT A MAJOR INFLUENCE
TODAY. WITH THE PRECIPITABLE WATERS RUNNING OVER 2 INCHES HEAVY
DOWNPOURS CAN BE EXPECTED AND FREQUENT LIGHTNING. THE 16 UTC RUN
OF THE HRRR IS ECHOING THE 13 UTC RUN WITH THE DIURNAL CONVECTION
CONTINUING OVER MUCH OF THE FORECAST AREA THROUGH 22 UTC THEN
DISSIPATING.
MAXIMUM TEMPERATURES ARE RUNNING IN THE MID TO UPPER 80S AND ARE
PEAKING FOR THE DAY. OVERNIGHT TEMPERATURES ARE EXPECTED TO DROP
INTO THE MIDDLE 70S INLAND AND THE UPPER 70S AT THE COAST.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...BIGGEST QUESTION MARK FOR THE SHORT TERM
WILL BE HOW FAR SOUTH DOES A COLD FRONT PROGRESS ACROSS THE
CAROLINAS.
AHEAD OF THIS FEATURE...SHARP RIDGING ALOFT COMBINED WITH
RETURN FLOW WILL PUMP HEAT AND HUMIDITY INTO THE REGION...AND HIGHS
WILL RISE INTO THE 90S EVERYWHERE AWAY FROM THE IMMEDIATE COAST.
THIS IS SEVERAL DEGREES ABOVE NORMAL FOR MID-AUGUST...AND THE HIGH
DEWPOINTS WILL MAKE HEAT INDEX VALUES RISE TO 100 OR SLIGHTLY
GREATER. AMPLE INSTABILITY WITHIN THIS AIRMASS WILL BE TAPPED BY A
SHORTWAVE PROGGED TO MOVE OVERHEAD IN THE AFTN...AND SCATTERED TO
POTENTIALLY WIDESPREAD CONVECTION IS POSSIBLE. MOS P-NUMBERS HAVE
INCREASED TO LIKELY ACROSS THE AREA...BUT THEY HAVE BEEN OVERDONE
RECENTLY. WILL BUMP POP TO HIGH-CHC LOCALLY WITH PERIODS OF HEAVY
RAINFALL THE BIGGEST THREAT. LOWS THURSDAY NIGHT WILL BE QUITE
WARM...FALLING INTO THE MID 70S...WITH SOME UPPER 70S POSSIBLE ALONG
THE COAST.
FRIDAY WILL BE THE TRANSITION DAY AS THE COLD FRONT TO THE WEST
MOVES ACROSS THE AREA. ALL GUIDANCE HAS INCREASED THE SPEED OF THIS
FEATURE...LIKELY DUE TO A STRONGER PARENT TROUGH AND VORT LOBE..WITH
LESS MID-LEVEL PARALLEL FLOW. WPC SUPPORTS THIS FASTER GUIDANCE AS
WELL...SO WILL SHOW THE FRONT MOVING OFFSHORE BY LATE FRIDAY.
CONVECTION WILL ACCOMPANY THIS BOUNDARY AS IT SWINGS S/SE FRIDAY
INTO FRIDAY NIGHT...BUT DRYING DOES OCCUR IN EARNEST LATE SO BEST
PRECIP CHANCES WILL BE THE FIRST HALF OF FRIDAY. TEMPS WILL REMAIN
ABOVE NORMAL THANKS TO WARM ADVECTION AHEAD OF THE BOUNDARY...BUT
WILL BE A FEW DEGREES COOLER THAN THURSDAY. LOWS FRIDAY NIGHT WILL
REMAIN ABOVE CLIMO AS WEAK COLD ADVECTION LAGS...WITH MINS DROPPING
INTO THE 72-75 DEGREE RANGE...WARMEST AT THE COAST.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 300 AM WEDNESDAY...COLD FRONT PUSHING OFFSHORE FIRST THING
SATURDAY WILL LEAVE CLEARING SKY CONDITIONS AND IMPROVING WEATHER
FOR THE WKND. WHILE THIS FASTER FROPA REPRESENTS A CHANGE IN THE
FORECAST...GUIDANCE IS IN GOOD AGREEMENT ATTM WITH A STRONG MID-
LEVEL PUSH...AND THE WKND IS LOOKING TO BE QUITE NICE LOCALLY NOW.
WEAK COOL ADVECTION BUT STRONG DRY ADVECTION WILL ERODE CLOUDS
SATURDAY...AND THEN LEAVE AMPLE SUNSHINE LATE SATURDAY AND ON
SUNDAY...AS PWATS DROP TO AROUND THE FIRST QUARTILE MOVING-AVERAGE
FOR LATE AUGUST. TEMPS THIS WKND WILL BE AROUND OR SLIGHTLY BELOW
CLIMO WITH N/NE WINDS...BUT OVERALL A PLEASANT WKND APPEARS TO BE IN
STORE. RETURN FLOW BEGINS TO REDEVELOP MONDAY WITH TEMPS WARMING
BACK TO SEASONABLE LEVELS OR SLIGHTLY ABOVE...BUT THIS WILL BE
ACCOMPANIED BY INCREASING PRECIP CHANCES AS WELL. GFS DRIVES A
POTENT SHORTWAVE OVERHEAD LATE MONDAY INTO TUESDAY...A PIECE OF THE
LONGER TROUGH TRAVERSING THE NORTHEAST...WHILE THE ECMWF SHOWS NO
SUCH FEATURE. FOR NOW WILL RAMP POP BACK UP TO CLIMO VALUES FOR
EARLY NEXT WEEK...MAINTAINING THE INHERITED FORECAST
&&
.AVIATION /18Z WEDNESDAY THROUGH TUESDAY/...
AS OF 18Z...EXPECT VFR FOR THE REST OF THE VALID TAF PERIOD WITH
ISOLATED TO SCATTERED SHRA/TSRA THIS AFTERNOON AND TONIGHT.
POTENTIAL FOR PATCHY MARGINAL MVFR FOG OVERNIGHT.
LATEST RADAR DEPICTS ISOLATED TO SCATTERED SHRA/TSRA DEVELOPING
ACROSS THE AREA. WHILE COULD SEE BRIEF PERIODS OF MVFR IN ANY HEAVY
DOWNPOURS...OVERALL EXPECT VFR THROUGH TONIGHT. SOUTHWEST WINDS WILL
INCREASE TO AOB 12 KTS THIS AFTERNOON...BECOMING LIGHT AND VARIABLE
TONIGHT. COULD SEE PATCHY AREAS OF MARGINAL MVFR FOG LATE
OVERNIGHT...THUS HAVE INTRODUCED TEMPO GROUP. AFTER DAYBREAK...VFR
WILL PREVAIL WITH SOUTHWEST WINDS.
EXTENDED OUTLOOK...SCATTERED CONVECTION IS EXPECTED THROUGH THE
PERIOD...MOST ACTIVE THURSDAY WITH BRIEF IFR CONDITIONS POSSIBLE.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM WEDNESDAY...LIGHT SOUTHWEST WINDS OVER THE WATERS
THIS MORNING WITH SEAS RUNNING 2 TO 3 FEET WITH A 1.3 EAST
SOUTHEAST SWELL. SCATTERED THUNDERSTORMS ARE POSSIBLE THIS
AFTERNOON AS A FEW STORMS THAT DEVELOP ALONG THE COAST COULD MOVE
OUT OVER THE WATER. THE MAIN THREAT APPEARS TO BE LIGHTNING.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...PRE- FRONTAL REGIME THURSDAY WILL LEAVE
SW WINDS OF 10-15 KTS ACROSS THE WATERS. THIS WILL BE SHORT-LIVED
HOWEVER AS A COLD FRONT RACES TOWARDS THE WATERS DURING FRIDAY.
THIS FRONT WILL CROSS INTO THE WATERS AND THEN DROP SOUTH BY
FRIDAY NIGHT...LEAVING WINDS SHIFTING FROM WEST...ALL THE WAY
AROUND TO THE EAST...AND THEN FINALLY TAKING ON A PREDOMINANT NE
DIRECTION LATE IN THE PERIOD. SPEEDS THROUGH FRIDAY WILL BE LIGHT
REGARDLESS OF DIRECTION...LESS THAN 10 KTS. SEAS THURSDAY WILL BE
2-3 FT WITH A SE SWELL AND SW WIND CHOP COMPRISING THE SPECTRUM.
WAVE HEIGHTS FRIDAY WILL DROP TO JUST 1-2 FT ON THE LIGHTER
WINDS...WITH A VARIETY OF WAVE GROUPS PRESENT.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 AM WEDNESDAY...COLD FRONT WILL BE SOUTH OF THE WATERS
SATURDAY MORNING...LEAVING NE WINDS IN ITS WAKE. THIS WIND DIRECTION
WILL PERSIST MUCH OF THE PERIOD...BUT A WEAKENING OF THE FRONT WILL
ALLOW RETURN FLOW AND SOUTHERLY WINDS TO REDEVELOP LATE. SPEEDS FROM
THE NE WILL BE 10-15 KTS...EASING AS THE WINDS SHIFT AT THE END OF
THE PERIOD. WAVE HEIGHTS WILL BE PRIMARILY WIND-WAVE DRIVEN...BUT OF
LOW AMPLITUDE AROUND 1-3 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...DRH
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1042 AM EDT WED AUG 19 2015
.SYNOPSIS...
UNSETTLED WEATHER WILL CONTINUE THROUGH MID WEEK AS TROPICAL
MOISTURE STREAMS INTO THE AREA AHEAD OF AN APPROACHING COLD
FRONT. THE FRONT WILL REACH THE COASTAL CAROLINAS BY FRIDAY AND
OFFSHORE OVER THE WEEKEND. ANOTHER COLD FRONT MAY APPROACH ON
TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM WEDNESDAY...THE AREA HAS CLEAR OUT OF CONVECTION AND
CLOUDS AFTER A SHORT WAVE PROGRESSES ACROSS THE FORECAST AREA THIS
MORNING. THE HRRR IS SHOWING VERY WEAK FORCING THE REMAINDER IN
THE SOUTHWEST FLOW ALOFT. INSTABILITIES ARE MODERATE FOR THIS
AFTERNOON AND THE PRIMARY THREAT APPEARS TO BE LOCALLY HEAVY
DOWNPOURS.
THE 13 UTC RUN OF THE HRRR IS SHOWING DIURNAL CONVECTION
DEVELOPING ALONG THE SEA BREEZE FIRST JUST AFTER 16 UTC AND THEN
BECOMING SCATTERED INLAND AND SLOWLY DISSIPATING AFTER SUNSET.
TEMPERATURES ARE RUNNING A LITTLE WARMER AS LACK OF CLOUD COVER IS
ALLOWING THE TEMPERATURES TO INCREASE QUICKER BUT EXPECTED THE
CLOUD COVER TO INCREASE QUICKLY THIS AFTERNOON WHEN THE CONVECTIVE
TEMPERATURE IS MET.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...BIGGEST QUESTION MARK FOR THE SHORT TERM
WILL BE HOW FAR SOUTH DOES A COLD FRONT PROGRESS ACROSS THE
CAROLINAS.
AHEAD OF THIS FEATURE...SHARP RIDGING ALOFT COMBINED WITH
RETURN FLOW WILL PUMP HEAT AND HUMIDITY INTO THE REGION...AND HIGHS
WILL RISE INTO THE 90S EVERYWHERE AWAY FROM THE IMMEDIATE COAST.
THIS IS SEVERAL DEGREES ABOVE NORMAL FOR MID-AUGUST...AND THE HIGH
DEWPOINTS WILL MAKE HEAT INDEX VALUES RISE TO 100 OR SLIGHTLY
GREATER. AMPLE INSTABILITY WITHIN THIS AIRMASS WILL BE TAPPED BY A
SHORTWAVE PROGGED TO MOVE OVERHEAD IN THE AFTN...AND SCATTERED TO
POTENTIALLY WIDESPREAD CONVECTION IS POSSIBLE. MOS P-NUMBERS HAVE
INCREASED TO LIKELY ACROSS THE AREA...BUT THEY HAVE BEEN OVERDONE
RECENTLY. WILL BUMP POP TO HIGH-CHC LOCALLY WITH PERIODS OF HEAVY
RAINFALL THE BIGGEST THREAT. LOWS THURSDAY NIGHT WILL BE QUITE
WARM...FALLING INTO THE MID 70S...WITH SOME UPPER 70S POSSIBLE ALONG
THE COAST.
FRIDAY WILL BE THE TRANSITION DAY AS THE COLD FRONT TO THE WEST
MOVES ACROSS THE AREA. ALL GUIDANCE HAS INCREASED THE SPEED OF THIS
FEATURE...LIKELY DUE TO A STRONGER PARENT TROUGH AND VORT LOBE..WITH
LESS MID-LEVEL PARALLEL FLOW. WPC SUPPORTS THIS FASTER GUIDANCE AS
WELL...SO WILL SHOW THE FRONT MOVING OFFSHORE BY LATE FRIDAY.
CONVECTION WILL ACCOMPANY THIS BOUNDARY AS IT SWINGS S/SE FRIDAY
INTO FRIDAY NIGHT...BUT DRYING DOES OCCUR IN EARNEST LATE SO BEST
PRECIP CHANCES WILL BE THE FIRST HALF OF FRIDAY. TEMPS WILL REMAIN
ABOVE NORMAL THANKS TO WARM ADVECTION AHEAD OF THE BOUNDARY...BUT
WILL BE A FEW DEGREES COOLER THAN THURSDAY. LOWS FRIDAY NIGHT WILL
REMAIN ABOVE CLIMO AS WEAK COLD ADVECTION LAGS...WITH MINS DROPPING
INTO THE 72-75 DEGREE RANGE...WARMEST AT THE COAST.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 300 AM WEDNESDAY...COLD FRONT PUSHING OFFSHORE FIRST THING
SATURDAY WILL LEAVE CLEARING SKY CONDITIONS AND IMPROVING WEATHER
FOR THE WKND. WHILE THIS FASTER FROPA REPRESENTS A CHANGE IN THE
FORECAST...GUIDANCE IS IN GOOD AGREEMENT ATTM WITH A STRONG MID-
LEVEL PUSH...AND THE WKND IS LOOKING TO BE QUITE NICE LOCALLY NOW.
WEAK COOL ADVECTION BUT STRONG DRY ADVECTION WILL ERODE CLOUDS
SATURDAY...AND THEN LEAVE AMPLE SUNSHINE LATE SATURDAY AND ON
SUNDAY...AS PWATS DROP TO AROUND THE FIRST QUARTILE MOVING-AVERAGE
FOR LATE AUGUST. TEMPS THIS WKND WILL BE AROUND OR SLIGHTLY BELOW
CLIMO WITH N/NE WINDS...BUT OVERALL A PLEASANT WKND APPEARS TO BE IN
STORE. RETURN FLOW BEGINS TO REDEVELOP MONDAY WITH TEMPS WARMING
BACK TO SEASONABLE LEVELS OR SLIGHTLY ABOVE...BUT THIS WILL BE
ACCOMPANIED BY INCREASING PRECIP CHANCES AS WELL. GFS DRIVES A
POTENT SHORTWAVE OVERHEAD LATE MONDAY INTO TUESDAY...A PIECE OF THE
LONGER TROUGH TRAVERSING THE NORTHEAST...WHILE THE ECMWF SHOWS NO
SUCH FEATURE. FOR NOW WILL RAMP POP BACK UP TO CLIMO VALUES FOR
EARLY NEXT WEEK...MAINTAINING THE INHERITED FORECAST
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
AS OF 12Z...AREAS OF MVFR DUE TO FOG THIS MORNING...GIVING WAY TO
VFR FOR THE REST OF THE VALID TAF PERIOD WITH ISOLATED TO SCATTERED
SHRA/TSRA POSSIBLE.
LATEST RADAR IMAGERY DEPICTS A FEW LIGHT SHOWERS ACROSS THE AREA
THIS MORNING...WITH OBSERVATIONS INDICATING LIGHT WINDS AND PATCHY
AREAS OF FOG. COULD SEE BRIEF MARGINAL MVFR DUE TO FOG THIS
MORNING...BUT CONFIDENCE IS LOW. EXPECT VFR TO PREVAIL LATER THIS
MORNING WITH ISOLATED TO SCATTERED SHRA/TSRA ACTIVITY THROUGH TODAY
AND SOUTHWEST WINDS INCREASING TO AOB 12 KTS. INTO THE EVENING
HOURS...CONVECTION WILL TAPER OFF AND WINDS WILL BECOME
LIGHT.
EXTENDED OUTLOOK...SCATTERED CONVECTION IS EXPECTED THROUGH THE
PERIOD...MOST ACTIVE WEDNESDAY AND THURSDAY WITH BRIEF IFR
CONDITIONS POSSIBLE.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM WEDNESDAY...LIGHT SOUTHWEST WINDS OVER THE WATERS
THIS MORNING WITH SEAS RUNNING 2 TO 3 FEET WITH A 1.3 EAST
SOUTHEAST SWELL. SCATTERED THUNDERSTORMS ARE POSSIBLE THIS
AFTERNOON AS A FEW STORMS THAT DEVELOP ALONG THE COAST COULD MOVE
OUT OVER THE WATER. THE MAIN THREAT APPEARS TO BE LIGHTNING.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...PRE- FRONTAL REGIME THURSDAY WILL LEAVE
SW WINDS OF 10-15 KTS ACROSS THE WATERS. THIS WILL BE SHORT-LIVED
HOWEVER AS A COLD FRONT RACES TOWARDS THE WATERS DURING FRIDAY.
THIS FRONT WILL CROSS INTO THE WATERS AND THEN DROP SOUTH BY
FRIDAY NIGHT...LEAVING WINDS SHIFTING FROM WEST...ALL THE WAY
AROUND TO THE EAST...AND THEN FINALLY TAKING ON A PREDOMINANT NE
DIRECTION LATE IN THE PERIOD. SPEEDS THROUGH FRIDAY WILL BE LIGHT
REGARDLESS OF DIRECTION...LESS THAN 10 KTS. SEAS THURSDAY WILL BE
2-3 FT WITH A SE SWELL AND SW WIND CHOP COMPRISING THE SPECTRUM.
WAVE HEIGHTS FRIDAY WILL DROP TO JUST 1-2 FT ON THE LIGHTER
WINDS...WITH A VARIETY OF WAVE GROUPS PRESENT.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 AM WEDNESDAY...COLD FRONT WILL BE SOUTH OF THE WATERS
SATURDAY MORNING...LEAVING NE WINDS IN ITS WAKE. THIS WIND DIRECTION
WILL PERSIST MUCH OF THE PERIOD...BUT A WEAKENING OF THE FRONT WILL
ALLOW RETURN FLOW AND SOUTHERLY WINDS TO REDEVELOP LATE. SPEEDS FROM
THE NE WILL BE 10-15 KTS...EASING AS THE WINDS SHIFT AT THE END OF
THE PERIOD. WAVE HEIGHTS WILL BE PRIMARILY WIND-WAVE DRIVEN...BUT OF
LOW AMPLITUDE AROUND 1-3 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HAWKINS
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
120 AM EDT WED AUG 19 2015
.SYNOPSIS...
UNSETTLED WEATHER WILL CONTINUE THROUGH MID WEEK AS TROPICAL
MOISTURE STREAMS INTO THE AREA AHEAD OF AN APPROACHING COLD
FRONT. THE FRONT WILL REACH THE COASTAL CAROLINAS BY FRIDAY AND
OFFSHORE OVER THE WEEKEND. ANOTHER COLD FRONT IS EXPECTED TO
REACH THE AREA TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 120 AM WEDNESDAY...ONE AREA OF SHOWERS WAS BRUSHING
MARLBORO AND ROBESON COUNTIES. OTHER SLOW MOVING SHOWERS AND
THUNDERSTORMS WERE MOVING ACROSS CENTRAL PORTIONS OF THE
CAROLINAS. THIS ACTIVITY WAS AHEAD OF A MID LEVEL SHORTWAVE WHICH
WILL BE MOVING ACROSS THE AREA OVERNIGHT.
WE DO EXPECT MAINLY ISOLATED THUNDERSTORMS AND SHOWERS TO PERSIST
AS THEY MOVE INTO WESTERN PORTIONS OF THE FORECAST AREA
OVERNIGHT. HOWEVER...THE HIGH RESOLUTION HRRR CONTINUES TO SHOW
THIS ACTIVITY WANING WITH TIME WHILE CONVECTION EVENTUALLY
BLOSSOMS ACROSS THE WATERS. THIS IS SIMILAR TO WHAT TRANSPIRED
LAST NIGHT. WILL SHOW LOW POPS...SMALL CHANCE/SLIGHT CHANCE FOR
THE REMAINDER OF THE NIGHT. HOWEVER... WILL TREND POPS HIGHER NEAR
THE IMMEDIATE COAST AS THE FLOW SHOULD ALLOW SOME OF THE LATE
NIGHT OCEAN SHOWERS AND THUNDERSTORMS TO BRUSH THE MORE IMMEDIATE
COAST.
STRATUS WAS BEGINNING TO EXPAND ACROSS THE EASTERN CAROLINAS LATE
THIS EVE. I HAVE INCLUDED PATCHY FOG FOR A GOOD PORTION OF THE
AREA. INLAND AREAS ARE FAVORED OVER THE MORE IMMEDIATE COAST DUE
TO THE MORE SIGNIFICANT RAINFALL THERE TODAY. ALTHOUGH A
DEVELOPING NOCTURNAL JET MAY FAVOR LOW STRATUS OVER FOG...THE
20-30 KT WINDS ABOVE THE BOUNDARY LAYER SHOULD BE RATHER SHORT-
LIVED.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...MID TO UPPER LEVEL RIDGE ALIGNED UP THE
SOUTHEAST COAST SANDWICHED BETWEEN UPPER LOW WELL OFF SHORE AND
TROUGH EXTENDING DOWN FROM THE GREAT LAKES WELL WEST OF OUR AREA.
THIS MID TO UPPER TROUGH WILL PUSH A COLD FRONT EAST INTO THE
CAROLINAS BEFORE IT LIFTS OFF TO THE NORTHEAST INTO CANADA BY
THURS NIGHT. PLENTY OF DEEP MOISTURE WILL STREAM INTO THE AREA
AHEAD OF THIS SYSTEM AND WILL COMBINE WITH MINOR SHORTWAVE ENERGY
AND LOCALIZED CONVERGENCE ALONG PIEDMONT TROUGH...SEA BREEZE AND
THE COLD FRONT UPSTREAM TO PRODUCE GREATER COVERAGE OF CLOUDS AND
CONVECTION THROUGH MID WEEK. LOCAL AREA WILL REMAIN ON THE TOP OF
THE RIDGE WITH A FLATTER W-SW FLOW ALOFT WHICH WILL AID IN
ADVECTING PLENTY OF DEBRIS CLOUDS AND STEERING CONVECTION TOWARD
THE LOCAL FORECAST AREA. MOISTURE PROFILES SHOW THE BRUNT OF THIS
MOISTURE IN THE MID TO UPPER LEVELS AS PLENTY OF MID TO HIGH LEVEL
DEBRIS CLOUDS STREAM INTO AREA. PCP WATER VALUES REMAIN ABOVE 2
INCHES THROUGH THE PERIOD. BY LATE THURS THE COLD FRONT SHOULD
DROP FAR ENOUGH SOUTH INTO THE COASTAL CAROLINAS BUT IT SHOULD
BEGIN TO LAY DOWN AND SLOW DOWN OUT AS THE UPPER FLOW FLATTENS
FURTHER AS MID TO UPPER TROUGH LIFTS OFF INTO CANADA. SOUTHERLY
SFC WINDS WILL BEGIN TO VEER AROUND TO THE WEST BY THURS. THIS
WILL PRODUCE A DEEPER DOWNSLOPE FLOW AND WILL HELP TO BREAK UP THE
CLOUDS AND PRODUCE WARMER TEMPS. BUT IT WILL ALSO ENHANCE LIFT AND
POTENTIAL FOR THUNDERSTORMS ACROSS THE AREA...ESPECIALLY CLOSER TO
THE COAST. EXPECT TEMPS TO REACH UP INTO THE MID TO UPPER 80S ON
WED AND INTO THE 90S MOST PLACES ON THURS.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 300 PM TUESDAY...A SLOW MOVING COLD FRONT LOOKS TO PUSH
THROUGH ON FRIDAY. WITH MID LEVEL RIDGING AHEAD OF THIS FEATURE
AND FAIRLY WEAK LOW LEVEL MOISTURE FLUX IT DOESN`T APPEAR THAT
THERE WILL BE MUCH RAIN QUANTITATIVELY EVEN THOUGH FORECAST
RAINFALL CHANCES MAY BE HIGHER THAN CLIMATOLOGY. THIS BOUNDARY
APPEARS TO STALL CLOSE ENOUGH TO THE COAST FOR SOME SMALL RAIN
CHANCES MAINLY ALONG THE BEACHES. SUNDAY AND MONDAY WILL BRING THE
LOWEST RAIN CHANCES OF THE PERIOD BUT WITH A LITTLE BIT OF
LINGERING LOW LEVEL MOISTURE ITS TOUGH TO GO WITH A COMPLETELY DRY
FORECAST. THEY SHOULD RAMP UP AGAIN ON TUESDAY WITH THE APPROACH
OF ANOTHER COLD FRONT. THIS NEXT FRONT MAY ALSO LACK MUCH IN THE
WAY OF MOISTURE FLUX BUT MAY HAVE BETTER UPPER LEVEL SUPPORT FOR
PRECIP GENERATION.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 06Z...PATCHES OF IFR INLAND THROUGH 13Z-15Z. ISOLATED
CONVECTION MAINLY OVER THE WESTERN PORTION OF THE CWA. SOME PATCHY
STRATUS IS LIKELY OVER MUCH OF THE REGION WITH WINDS AT 1K FEET
AROUND 20 KTS. CONVECTIVE DEBRIS WILL KEEP CEILINGS IN THE MID
CLOUD RANGE...WITH PATCHY IFR CIGS. IF WE MANAGE TO GET SOLAR
INSOLATION DURING THE DAY TODAY...CONVECTION COULD BE STRONGER
THAN TODAY WITH MORE COVERAGE.
EXTENDED OUTLOOK...SCATTERED CONVECTION IS EXPECTED THROUGH THE
PERIOD...MOST ACTIVE WEDNESDAY AND THURSDAY WITH BRIEF IFR
CONDITIONS POSSIBLE.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 120 AM WEDNESDAY...SW WINDS WILL PERSIST FOR THE REMAINDER
OF THE NIGHT AT UP TO AROUND 15 KT. SEAS WILL BE 2 TO 3 FT. A 9 TO
10 SECOND EASTERLY SWELL WAS BEING OBSERVED AT THE BUOYS.
A WEAK TROUGH OF LOW PRESSURE ACROSS THE INLAND CAROLINAS AND
BERMUDA HIGH PRESSURE WILL BETTER DEFINE THE PRESSURE GRADIENT...
ESPECIALLY ON WED. WE DO EXPECT SHOWERS AND THUNDERSTORMS TO BEGIN
BLOSSOMING ACROSS THE WATERS AFTER MIDNIGHT. MARINERS SHOULD
EXPECT REDUCED VISIBILITY IN HEAVY RAIN WITH THIS ACTIVITY.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...WEAK RETURN FLOW ON WEDNESDAY WILL VEER TO
THE S-SW ON THU AS COLD FRONT REACHES INTO THE CAROLINAS. THIS
WILL PRODUCE A SLIGHT TIGHTENING OF GRADIENT AND ALLOW WINDS TO
INCREASE UP TO 15 KT LATE WED INTO THU. THIS SLIGHT INCREASE IN
WINDS WILL PRODUCE ENOUGH SOUTHERLY PUSH TO INCREASE SEAS JUST
ABOVE 3 FT.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 300 PM TUESDAY...A COLD FRONT DROPS INTO THE AREA. THIS
BOUNDARY WILL BE FAIRLY SLOW MOVING AND ALSO DECELERATING MAKING
FOR A VERY GRADUAL WIND SHIFT ACROSS THE WATERS WHILE SEAS REMAIN
CAPPED AT 2 FT. E TO NE WINDS ON SATURDAY EXPECTED TO STAY 10 KT
OR LESS BEHIND THE BOUNDARY AND NO CHANGE IN WAVE HEIGHT EVEN IF
THE FROPA SLIGHTLY STEEPENS WAVE FACES FOR A BRIEF TIME. THE
BOUNDARY REMAINS JUST TO OUR SOUTH IN A DISSIPATING STATE BY
SUNDAY AND IT MAY IN FACT BE TOUGH TO FIND ON SURFACE MAPS. THE
HIGH THAT HAD BEEN BUILDING IN BEHIND IT WEAKENS RAPIDLY WITH THE
NET LOCAL RESULT LITTLE CHANGE IN WIND OR WAVES FROM THOSE OF
SATURDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RJD/MJC
SHORT TERM...RGZ
LONG TERM...MBB
AVIATION...DL/8
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
710 PM CDT THU AUG 20 2015
.UPDATE...
ISSUED AT 706 PM CDT THU AUG 20 2015
SHORT WAVE WITH SHOWERS AND A FEW STORMS MOVING EAST THRU EAST
CENTRAL SASK INTO WCNTRL MANITOBA EARLY THIS EVENING. WEAK SFC
BOUNDARY DOES EXTEND FROM LOW IN NORTHEASTERN SASK TO NR YORKTON
TO NEAR ESTEVAN. THIS BOUNDARY WILL MOVE EAST AND WASH OUT OVER NE
ND TONIGHT. HRRR HAS BEEN TOO AGRESSIVE WITH PRECIP SO FAR INTO NW
ND. BUT RADAR SHOWS A COUPLE SMALL SHOWERS ALONG MANITOBA-NORTH
DAKOTA-SASK BORDER REGION AT 00Z. WITH SOME MID CLOUD ACTIVITY IN
THIS AREA DID KEEP IDEA OF LOW POP FOR -SHRA ALONG INTL BORDER
TONIGHT THOUGH ADJUSTED TIMING A BIT IN NW FCST AREA TO 02Z
INSTEAD OF STARTING AT 00Z.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 245 PM CDT THU AUG 20 2015
THE MAIN CHALLENGE WILL BE SEVERE POTENTIAL SATURDAY WITH A POTENT
STORM SYSTEM. MODELS ARE COMING INTO BETTER AGREEMENT WITH A
SLOWER SOLUTION WITH A CLOSED OFF UPPER LOW...WITH SIGNIFICANT
WRAP AROUND PRECIP IN THE NORTH AS WELL SAT NIGHT INTO
SUNDAY...ALONG WITH STRONG WINDS.
FOR TONIGHT...THERE WILL BE A WEAK WAVE/UPPER SPEED MAX SKIRTING
THE CANADIAN BORDER WITH A 25-30KT LLJ AND SOME WEAK ELEVATED
INSTABILITY. THE CAM MODELS INDICATE A WEAK BAND OF SHOWERS ACROSS
THE NORTH INTO FRIDAY MORNING.
ON FRIDAY...THERE COULD BE SOME MORNING SHOWERS IN NW
MN...OTHERWISE IT SHOULD BE DRY AND WARM WITH HIGHS INTO THE
MID...PERHAPS UPPER 80S.
FOR FRI NIGHT...ELEVATED INSTABILITY AND DEEP MOISTURE WILL
INCREASE THROUGHOUT THE AREA. EXPECT ISOLATED TO SCATTERED SHOWERS
AND STORMS TO DEVELOP IN ALL AREAS...WITH THE BEST THREAT IN THE
FAR NORTH LATE.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 245 PM CDT THU AUG 20 2015
ON SATURDAY...AN STRONG UPPER LOW WILL MOVE INTO THE DAKOTAS WITH
A WARM...UNSTABLE AIRMASS OVER THE FORECAST AREA. THERE WILL BE A
FRONT MOVING FROM WEST TO EAST ALONG WITH SFC LOW PRESSURE LIKELY
MOVING ACROSS THE NORTHERN VALLEY SAT AFTERNOON. DEEP LAYERED
SHEAR VALUES SHOULD INITIALLY LAG THE WARM SECTOR...BUT MAY CATCH
UP BY AFTERNOON. THIS INCREASING DEEP LAYERED SHEAR ALONG WITH
AMPLE INSTABILITY AND MLCAPE AROUND 2000 J/KG IN THE EAST SHOULD
MEAN SOME SEVERE STORMS. REFER TO THE SPC DAY 3 OUTLOOK THAT HAS
AS SLIGHT RISK THAT MAY BE INCREASED EVEN FURTHER GIVEN THE VERY
STRONG UPPER SYSTEM AND SHEAR/INSTABILITY FIELDS. THIS HAS THE
POTENTIAL TO BE A FAIRLY SIGNIFICANT SEVERE WEATHER EVENT...STAY
TUNED.
FOR SAT NIGHT AND SUNDAY...WINDS WILL INCREASE ON THE BACK SIDE OF
DEPARTING LOW PRESSURE. THE GFS IS VERY STRONG WITH WINDS WITH
NEARLY 65KT TO MIX FROM 850MB LATE SAT NIGHT INTO SUNDAY. THERE
WILL ALSO BE A SIGNIFICANT DEFORMATION SHOWER BAND THAT COULD
PRODUCE AN INCH OF RAIN IN THE NORTH...WHICH WOULD BE WELCOME
SINCE IT HAS BEEN VERY DRY. TEMPS ON SUNDAY WILL BE COOL IN THE
60S AND IT WILL BE A WINDY DAY.
FOR SUNDAY NIGHT THROUGH THURSDAY...THE DEPARTING LOW PRESSURE
SYSTEM SHOULD BE PUSHING THROUGH THE MINNESOTA ARROWHEAD AND
WESTERN ONTARIO FROM SUNDAY NIGHT INTO MONDAY MORNING...WITH A
STRONG PUSH /NORTHWEST FLOW/ OF CANADIAN POLAR AIR DROPPING INTO
THE AREA IN ITS WAKE. SEASONABLY COOLER AND DRIER AIR SHOULD
PERSIST MONDAY INTO TUESDAY... WITH A RETURN SOUTHERLY FLOW
SETTING UP ACROSS THE AREA AFTER MIDDAY TUESDAY. THEN BOTH THE GFS
AND ECMWF SHOW AN INCREASINGLY WARMER AND WETTER PATTERN FROM
WEDNESDAY INTO THURSDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 706 PM CDT THU AUG 20 2015
VFR CONDITIONS THRU THE PD. A FEW HIGH BASED CU THIS EVENING WILL
DISSIPATE AND TO BE REPLACED BY A LITTLE CIRRUS...WITH THICKER
CIRRUS AND SOME MID CLOUD OVERNIGHT ALONG THE INTL BORDER. SOUTH
WINDS WILL DIMINISH THIS EVENING BUT REMAIN GENERALLY SOUTHERLY 5
TO 12 KTS THRU FRIDAY. NO PRECIP AT ANY TAF SITE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...DK
LONG TERM...GUST/DK
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1221 AM CDT WED AUG 19 2015
.UPDATE...
ISSUED AT 1216 AM CDT WED AUG 19 2015
A FEW MINOR CHANGES WERE MADE TO THE PRECIPITATION FORECAST AND
TEMPERATURES.
ISOLATED SHOWERS CONTINUE ACROSS WESTERN AND CENTRAL NORTH DAKOTA.
THE HRRR AND RAP CONTINUE THESE SHOWERS THROUGH THE NIGHT.
THEREFORE...EXTENDED BY SPATIALLY AND TEMPORALLY PRECIP CHANCES
WEST AND CENTRAL. A BAND OF STEADY RAIN CONTINUED ACROSS SOUTHEAST
NORTH DAKOTA. THIS BAND WILL SLOWLY MOVE OUT BY DAYBREAK.
TEMPERATURES WERE FALLING A LITTLE FASTER THAN PREVIOUSLY FORECAST
ACROSS THE NORTH WHERE CLOUDS HAVE THINNED OUT. LOWERED OVERNIGHT
LOWS A FEW DEGREES.
UPDATE ISSUED AT 935 PM CDT TUE AUG 18 2015
SHOWERS AND ISOLATED THUNDERSHOWERS IN WESTERN NORTH DAKOTA WERE
DIMINISHING THIS PAST HOUR AFTER SUNSET. EXPECT ONLY ISOLATED LIGHT
SHOWERS IN THE NEXT HOUR OR TWO IN THE WEST.
MEANWHILE THE SURFACE LOW HAD MOVED NORTHEASTWARD INTO SOUTHERN
MINNESOTA IN THE PAST FEW HOURS. THE RAIN SHIELD ASSOCIATED WITH THE
WRAP AROUND PRECIPITATION WAS PERSISTING OVER EASTERN PORTIONS OF
LAMOURE AND DICKEY COUNTIES. EXPECT THESE SHOWERS TO END FROM WEST
TO EAST BY LATE EVENING OR SHORTLY AFTER MIDNIGHT.
OTHERWISE...ADJUSTED HOURLY TEMPERATURES BASED ON LATEST TRENDS.
CURRENT FORECAST REMAINS ON TRACK.
UPDATE ISSUED AT 631 PM CDT TUE AUG 18 2015
CURRENTLY...A SURFACE LOW WAS OVER THE BORDER OF
IOWA/MINNESOTA/SOUTH DAKOTA...WITH HIGH PRESSURE OVER THE FRONT
RANGE OF MONTANA. THE UPPER LEVEL LOW WAS OVER EASTERN SOUTH DAKOTA.
A LARGE AREA OF RAIN SHOWERS CONTINUED NORTH AND WEST OF THE SURFACE
LOW...WHERE OVERCAST SKIES WERE KEEPING TEMPERATURES IN THE 50S AND
60S...AS IN THE JAMES VALLEY. FARTHER WEST WHERE THERE WERE BREAKS
IN THE OVERCAST...TEMPERATURES WERE IN THE UPPER 60S AND INTO THE
70S. ALSO OVER WESTERN NORTH DAKOTA THERE WAS ENOUGH SURFACE HEATING
AND UPPER LEVEL INSTABILITY FOR SOME ISOLATED TO SCATTERED SHOWERS
AND THUNDERSTORMS. NO SEVERE WEATHER EXPECTED WITH THESE
STORMS...WITH UPPER LEVEL SUPPORT MINIMAL...AND WEAK SHEAR.
ONLY CHANGE IN THIS UPDATE WAS TO INCREASE PRECIP CHANCES IN
LAMOURE/DICKEY/MCINTOSH COUNTIES WITH CURRENT RADAR LOOPS INDICATING
MORE COVERAGE IN SHOWERS. MINOR HOURLY TEMPERATURE ADJUSTMENTS AS
WELL.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 311 PM CDT TUE AUG 18 2015
CURRENT SURFACE ANALYSIS PLACES LOW OVER NORTHWESTERN IOWA INTO
SOUTHWESTERN MINNESOTA WITH HIGH PRESSURE WORKING INTO THE LEE OF
THE NORTHERN ROCKIES. UPPER LEVEL ANALYSIS PLACES CUT OFF LOW OVER
EASTERN SOUTH DAKOTA WITH RIDGE OFF THE WEST COAST. BROAD AREA OF
RAINFALL CONTINUES OVER NORTHEAST SOUTH DAKOTA WITH THIS SYSTEM
WITH SOME PRECIPITATION ON THE NORTHERN FRINGES CONTINUING OVER
THE SOUTHERN JAMES RIVER VALLEY. WEAK SHORT WAVE NOTED IN
CYCLONIC FLOW BEHIND THE LOW IS RESULTING IN SOME
SHOWERS/THUNDERSTORMS OVER WESTERN NORTH DAKOTA.
FOR THE REST OF THIS AFTERNOON INTO THIS EVENING...UPPER LOW WILL
SLOWLY LIFT TOWARDS THE NORTHEAST WITH RAIN OVER THE SOUTHERN
JAMES RIVER VALLEY SLOWLY TAPERING OFF FROM WEST TO EAST. AS FOR
THE PRECIPITATION OVER WESTERN NORTH DAKOTA...LATEST HIGH-RES
GUIDANCE SUGGESTS THAT IT SHOULD BE DIMINISHING BY AROUND MID-
EVENING. OTHERWISE...A COOL NIGHT IS IN STORE WITH MOST LOCATIONS
DIPPING INTO THE 40S.
ON WEDNESDAY...UPPER LOW LIFTS OVER MINNESOTA WITH RIDGING
DEVELOPING OVER OUR AREA. EXPECT DRY CONDITIONS WITH TEMPERATURES
REMAINING AROUND 10 DEGREES BELOW AVERAGE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 311 PM CDT TUE AUG 18 2015
WARMING TEMPERATURES AND THUNDERSTORM CHANCES FRIDAY AFTERNOON
THROUGH SATURDAY HIGHLIGHT THE EXTENDED RANGE.
FOR WEDNESDAY NIGHT...AN UPPER LEVEL LOW LOCATED OVER NORTHERN
MINNESOTA WILL CONTINUE TO PUSH EAST WITH A RIDGE BUILDING FROM
THE WEST...KEEPING THE DAKOTAS IN NORTHWEST FLOW WITH DIMINISHING
CLOUDS. TEMPERATURES WILL BEGIN TO WARM ON THURSDAY...WITH HIGHS
GENERALLY REACHING INTO THE 80S AS WE START TO TRANSITION INTO A
BRIEF PERIOD OF NEAR ZONAL FLOW.
A POTENT SHORTWAVE TROUGH WILL APPROACH THE COUNTY WARNING AREA
FROM THE PACIFIC NORTHWEST BY LATE FRIDAY AFTERNOON...BRINGING
WITH IT HIGH TEMPERATURES NEAR 90...MOISTURE RETURN...AND
SOUTHWEST FLOW. AN ASSOCIATED COLD FRONT WILL MAKE ITS WAY ACROSS
THE REGION OVERNIGHT FRIDAY AND INTO SATURDAY...BRINGING CHANCES
OF SCATTERED SHOWERS AND THUNDERSTORMS. AS FAR AS SEVERE WEATHER
CHANCES GO...THERE IS STILL QUITE A BIT OF UNCERTAINTY. TODAYS 12Z
ECMWF IS A BIT QUICKER WITH THE UPPER LEVEL WAVE PROPAGATION...AND
IS MORE ROBUST WITH MOISTURE RETURN/INSTABILITY WHEN COMPARED WITH
THE 12Z GFS. THEREFORE...STRONG TO SEVERE STORMS WOULD BE MORE
LIKELY LATE FRIDAY AFTERNOON AND INTO SATURDAY IF THE EUROPEAN
SOLUTION WERE TO VERIFY. WILL HAVE TO WATCH MODEL TRENDS AS THE
TIME FRAME GROWS CLOSER.
SATURDAY WILL FEATURE ANOTHER COOL DOWN AFTER THE FRONTAL
PASSAGE...WITH SOME LINGERING SHOWERS AND THUNDERSTORMS POSSIBLE
INTO SUNDAY. THE WESTERN RIDGE WILL BEGIN TO BUILD EAST AGAIN AT
THE BEGINNING OF WEEK...PROMOTING ANOTHER WARMUP FOR THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1216 AM CDT WED AUG 19 2015
VFR CONDITIONS AT ALL TAF SITES THROUGH THE TAF PERIOD. ISOLATED
SHOWERS ARE POSSIBLE AT KDIK/KBIS LATE TONIGHT...BUT COVERAGE AND
CONFIDENCE NOT HIGH ENOUGH TO WARRANT MENTION IN THE TAF.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AJ
SHORT TERM...JJS
LONG TERM...ZH
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1149 PM CDT TUE AUG 18 2015
.UPDATE...
ISSUED AT 1146 PM CDT TUE AUG 18 2015
HRRR AND OTHER MODELS CONTINUE TO INDICATE THE POP GRADIENT AND NW
EDGE OF RAIN IN GOOD SHAPE IN THE GRIDS AND NO FURTHER CHANGES
REQUIRED.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 242 PM CDT TUE AUG 18 2015
FORECAST CHALLENGE FOR TONIGHT IS WHICH HI RES MODEL TO FOLLOW FOR
EVOLUTION OF LOW PRESSURE SYSTEM OVER FAR SERN SD AS IT MOVES
EAST AND THEN NORTH...CLIPPING SOUTHERN AND EASTERN PORTIONS OF
THE CWA. HRRR HAS CONSISTENTLY VERIFIED WITH PLACEMENT OF PRECIP
BEST EACH HOUR...ALTHOUGH EARLIER RUNS THAT SPREAD RAIN AS FAR
NORTH AS FARGO WERE THOUGHT TO BE OVERLY BULLISH AND I HAD FAVORED
THE NMM/ARW...WHICH KEPT PRECIP FURTHER SOUTH WITH THE NE FLOW IN
SFC-H850 LAYER. HOWEVER...15Z HRRR RUN DID A VERY GOOD JOB WITH
PLACEMENT OF PRECIP VERIFIED BY 19Z RADAR IMAGERY. THEREFORE WILL
CONTINUE HRRR TRENDS THROUGH THE EVENING THROUGH 06Z...THEN A FCST
BLEND THROUGH END OF EVENT FOR OUR CWA.
TONIGHT AND TOMORROW...PRECIP OVER SOUTHWEST MN WILL CONTINUE TO
LIFT FROM SW MN INTO W CNTRL MN...HOWEVER WITH SFC LOW MOVING
NE...DO NOT EXPECT RAIN TO LIFT MUCH FURTHER NORTH THAN HILLSBORO
WITHIN THE RRV. LOW BEGINS TO LIFT MORE NORTHWARD AFTER
MIDNIGHT...EVENTUALLY MOVING OVER LAKE SUPERIOR WED AFTN. QUESTION
IS HOW MUCH PRECIP WILL BACK INTO NW MN...AND CURRENT TRENDS ARE
KEEPING MOST OF THE NORTHERN VALLEY AND KITTSON/MARSHALL/NW POLK
COUNTIES DRY. 00Z ECMWF WAS THE FURTHEST WEST AND HAVE DISCOUNTED
IT...PREFERRING A GFS/GEM/NAM BLEND FOR WEDNESDAY POPS. HIGHEST
RAINFALL RATES WITHIN DEFORMATION ZONE SHOULD BE OVER CNTRL
MN...WHERE HPC QPF IS SHOWING UP TO TWO AND A QUARTER INCHES OF
PRECIP WITH A SHARP...DECLINING GRADIENT WESTWARD INTO THE
SOUTHERN VALLEY. CURRENT PRECIP TOTAL THOUGHTS ARE AROUND HALF AN
INCH IN FARGO...LITTLE IF ANY IN GRAND FORKS...RISING TO AROUND 2
INCHES AS FAR EAST AS PARK RAPIDS.
WED NIGHT...SYSTEM PULLS OUT OF LAKE SUPERIOR REGION INTO CNTRL
ONTARIO...SLOWLY PULLING PRECIP OUR OF FAR EAST AND NORTHEASTERN
ZONES BY 12Z THU. CLEARING IN THE WEST...IN ADDITION TO RELAXING
PRESSURE GRADIENT WINDS...WILL ALLOW OVERNIGHT LOWS TO FALL INTO
THE UPPER TO MID 40S ACROSS MOST OF THE REGION...WARMEST IN THE
FAR EAST WHERE CLOUD COVER WILL LINGER OVERNIGHT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 242 PM CDT TUE AUG 18 2015
THURSDAY AND FRIDAY...HIGH PRESSURE MOVES INTO REGION BRINGING
INCREASED SOLAR AND REBOUNDING TEMPERATURES TO NEAR SEASONAL NORMS
ON THURSDAY. RETURN FLOW SETS UP THU NIGHT INTO FRIDAY AND WEAK
SOUTHERLY FLOW THROUGH THE DAY FRIDAY WILL RESULT IN TEMPS
CLIMBING BACK INTO THE MID 80S.
THU NIGHT INTO FRIDAY...PASSING MID LEVEL TROUGH SATURDAY WILL DRAG
ANOTHER COLD FRONT ACROSS THE REGION. TIMING OF FRONT WOULD BRING
BEST T CHANCES ACROSS EASTERN HALF OF THE FA. SUNDAY WILL BE
COOLER FOLLOWED BY MODERATING TEMPERATURES INTO EARLY NEXT WEEK
WITH DRY CONDITIONS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1146 PM CDT TUE AUG 18 2015
RAIN WILL CONTINUE FARGO-BEMIDJIJ AREAS THROUGH WEDNESDAY MORNING
(FAR) AND INTO EARLY AFTERNOON (BJI). SOME CONCERN ESP AT BJI OF
LOWER MVFR OR MAYBE IFR CIGS TOWARD SUNRISE AS DRY AIR ALOFT MOVES
IN. SEEING LOWER CIGS TO THE SOUTH MOVING INTO WADENA AND POINTS
SOUTH. OTHERWISE VFR AT THE REST OF THE TAF SITES...THOUGH WOULD
BE SUPRISED TO SEE BRIEF MVFR CIG AT FARGO NR SUNRISE. WILL
MAINTAIN DRY GFK-TVF-DVL. NORTH WINDS INCREASING TO 12 TO 25 KTS
AT MOST SITES AS SURFACE LOW MOVES NORTHEAST TOWARD DULUTH AND NW
WISCONSIN.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...SPEICHER
LONG TERM...SPEICHER/VOELKER
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
928 PM EDT THU AUG 20 2015
.SYNOPSIS...
A COLD FRONT HAS MOVED EAST OF THE AREA WITH COOLER AND DRIER AIR
SETTLING OVER THE AREA BEHIND IT. A SURFACE AREA OF HIGH PRESSURE
TO OUR WEST WILL MOVE INTO THE AREA FRIDAY AND LINGER THROUGH THE
WEEKEND. THE NEXT CHANCE FOR RAIN WILL BE SUNDAY NIGHT INTO MONDAY
WHEN A COLD FRONT ARRIVES.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
UPPER TROUGH WILL LIFT ACROSS THE CENTRAL GREAT LAKES OVERNIGHT.
THERE WILL BE SOME INCREASED LIFT OVER THE LAKE AS THE COOLER AIR
ARRIVES IN THE WAKE OF THE TROUGH. THERE COULD BE A FEW SHOWERS
THAT DEVELOP FROM THE ERIE AREA NORTHWARD INTO NY STATE. HOWEVER
THE MAIN IMPACT WILL BE AN INCREASE OF CLOUD COVER FROM CLEVELAND
TO ERIE THROUGH THE EVENING.
PREVIOUS DISCUSSION...
THE WATER VAPOR SATELLITE IMAGERY DISTINCTLY DEFINES THE TROUGH
OVER THE UPPER LAKES AND THE DRIER AIR FILTERING INTO THE OHIO
VALLEY ALOFT. AT THE SURFACE HIGH PRESSURE OVER THE PLAINS WILL
SLIDE EAST OVERNIGHT AND LINGER OVER THE AIR INTO THE WEEKEND. DEW
POINTS HAVE DROPPED 10-15F SINCE THIS MORNING...WHICH WILL SUPPORT
NOTABLY COOLER TEMPERATURES OVERNIGHT. NCAR ENSEMBLES ALONG WITH
THE RUC ARE SUGGESTING DEW POINTS INTO THE UPPER 40S
OVERNIGHT...HOWEVER NOT SEEING ANY 40S UPSTREAM OR NEAR THE AREA
DESPITE A FAIR AMOUNT OF AFTERNOON MIXING. WITH DEW POINTS IN THE
LOW TO MID 50S...MOSTLY CLEAR SKIES...AND WINDS TAPERING OFF AFTER
DARK...WILL KEEP TEMPERATURES IN THE LOW TO MID 50S OVERNIGHT.
ONLY FLY IN THE OINTMENT WILL BE ANY POTENTIAL DEVELOPMENT OVER
THE LAKE AS THE H850 AND WATER TEMPERATURES DIFFER BY ABOUT 14C.
THE BEST CHANCE FOR ANYTHING TO DEVELOP WILL BE BETWEEN 06 AND 15Z
FRI...BUT AT THIS TIME WILL KEEP ONLY ISOLATED RAIN OVER THE
EASTERN PORTIONS OF THE LAKE AND NOT INTO ERIE PA.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY NIGHT/...
AS THE HIGH BUILDS OVERHEAD FRIDAY ANY LAKE ACTIVITY WILL BE SHUT
DOWN BY THE DRIER AIR AND THE SINKING INVERSION. LOOK FOR SUNNY
SKIES AND TEMPERATURES IN THE 70S. THE HIGH WILL SHIFT EAST ON
SATURDAY WHICH WILL SUPPORT SOME WEAK RETURN FLOW WHICH WILL
CONTINUE INTO SUNDAY. MEANWHILE THE NW FLOW ALOFT WILL TURN TO
THE SW WITH WARMER TEMPERATURES ADVECTING IN WITH H850 REACHING
12C WHICH WILL TRANSLATE INTO GRADUAL WARMING AT THE SURFACE. THE
NEXT CHANCE FOR PRECIPITATION WILL BE ASSOCIATED WITH ANOTHER MID
LEVEL TROUGH MOVING OUT OF THE ROCKIES. AN ASSOCIATED COLD FRONT
WILL REACH THE AREA SUNDAY NIGHT AND WITH WARMER/MOIST AIR AND AN
INCREASE IN THE LOW LEVEL JET CAN`T RULE OUT SOME THUNDERSTORMS.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
A COLD FRONT WILL BE MOVING THROUGH THE EASTERN EDGE OF THE AREA
MONDAY MORNING ALONG WITH A FEW LINGERING SHOWERS. COLD ADVECTION
WILL OVERSPREAD THE REGION IN THE WAKE OF THE COLD FRONT. THE
UPPER AIR PATTERN WILL EXHIBIT A LONG WAVE TROUGH OVER ONTARIO
EARLY IN THE EXTENDED WITH THIS FEATURE LIFTING FARTHER NORTH AND
ALLOWING A MORE ZONAL FLOW TO DEVELOP. BELOW NORMAL TEMPERATURES
ARE EXPECTED WITH GENERALLY DRY CONDITIONS BUT A FEW SHOWERS ARE
POSSIBLE WEDNESDAY AFTERNOON AND EVENING MAINLY OVER NORTHWEST PA
WHERE A MOIST CYCLONIC FLOW ALOFT ALONG WITH WELL MIXED ADIABATIC
CONDITIONS ARE EXPECTED.
CONDITIONS WILL WARM ON THURSDAY AND FRIDAY AS THE 850 MB
TEMPERATURES RISE TO MORE SEASONAL LEVELS AND MORE SUNSHINE
PREVAILS.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
COOL AIR ALOFT WILL SUPPORT LAKE EFFECT CLOUDS TONIGHT AND FRI
MORNING OVER LAKE ERIE. A TROUGH MOVING EAST ACROSS LAKE ERIE WILL
CAUSE THE MEAN LOW LEVEL WINDS TO VEER TO WNW WHICH WILL PROBABLY
PRODUCE SCT TO BKN CONDITIONS AT ERI LATE TONIGHT AND FRI MORNING.
HIGH PRESSURE PUSHES NE OVER OH FOR FRI AFTERNOON WHICH SHOULD
LEAD TO SLOW DISSIPATION OF THE LAKE EFFECT CLOUDS FRI AFTERNOON.
DAYTIME HEATING MAY PRODUCE SCT CU IN OTHER PARTS OF THE EAST BY
MIDDAY FRI BUT THIS CU WILL DISSIPATE BY EARLY EVENING.
WINDS WILL CONTINUE TO DIMINISH NEXT FEW HOURS AS TEMPS COOL AND
AIRMASS STABILIZES EXCEPT WINDS MAY CONTINUE TO RUN 8 TO 10 KNOTS AT
ERI FOR MUCH OF THE NIGHT.
OUTLOOK...NON VFR CONDITIONS POSSIBLE SUNDAY NIGHT WITH THE PASSAGE
OF A COLD FRONT AND POSSIBLE SHOWERS AND THUNDERSTORMS.
&&
.MARINE...
SMALL CRAFT CONDITIONS PREVAIL IN THE WAKE OF THE COLD
FRONT THAT HAS SWEPT EAST THROUGH THE REGION. A RATHER STRONG
PRESSURE GRADIENT FOR SUMMER ALONG WITH COLD ADVECTION ALOFT WILL
ALLOW MIXING OF HIGHER MOMENTUM AIR TO THE SURFACE. WITH 850 MB
TEMPERATURES EXPECTED TO DROP TO NEAR 10C AND LAKE SURFACE
TEMPERATURES FROM 22-24C... NEAR ADIABATIC LAPSE RATE IS EXPECTED
OVER THE LAKE WHICH WILL PERMIT DEEP MIXING AND STRONGER WINDS TO
PREVAIL. WILL CONTINUE WITH SMALL CRAFT ADVISORY THROUGH 08Z EAST
OF THE ISLANDS. IT MAY NEED TO BE EXTENDED SLIGHTLY LONGER IN THE
EASTERN HALF OF THE LAKE WHERE THE STRONGER PRESSURE GRADIENT WILL
LINGER.
HIGH PRESSURE WILL GRADUALLY BUILD SOUTH OF THE LAKE FRIDAY AND THEN
REMAIN OVER THE REGION INTO THE WEEKEND. WINDS WILL CONTINUE TO
DIMINISH FRIDAY AND BE LIGHT ON SATURDAY. SOUTHERLY WINDS WILL
INCREASE ON SUNDAY AS ANOTHER FRONTAL BOUNDARY APPROACHES WITH ITS
PASSAGE EXPECTED SUNDAY NIGHT. SMALL CRAFT CONDITIONS WILL LIKELY
DEVELOP IN THE WAKE OF THAT FRONTAL PASSAGE GIVEN THE COOLING ALOFT
DOWN TO JUST BELOW 10C AT 850 MB. WINDS WILL DECREASE ON TUESDAY AS
HIGH PRESSURE BUILDS INTO THE REGION.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT FRIDAY FOR LEZ144>149.
&&
$$
SYNOPSIS...JAMISON
NEAR TERM...JAMISON/MULLEN
SHORT TERM...JAMISON
LONG TERM...LAPLANTE
AVIATION...ADAMS
MARINE...ADAMS/LAPLANTE
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1111 AM EDT WED AUG 19 2015
.SYNOPSIS...
WARM AND HUMID AIR TODAY WILL ALLOW FOR SHOWERS AND THUNDERSTORMS
TO DEVELOP...IN ADVANCE OF A COLD FRONT THAT WILL MOVE THROUGH THE
AREA THURSDAY MORNING. MUCH DRIER CONDITIONS ARE EXPECTED ON
THURSDAY AND FRIDAY...WITH SLIGHTLY COOLER TEMPERATURES AND LESS
HUMIDITY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A PLUME OF HIGHER PWATS...AROUND 2"...WILL CONTINUE TO ADVECT
NORTHEAST INTO THE REGION THIS AFTERNOON. CURRENT RADAR MOSAIC
CONTINUES TO SHOW AN EMBEDDED DISTURBANCE NEAR THE TRI-STATE
REGION WITH SHOWERS...AND A FEW LIGHTNING STRIKES. THIS FEATURE
WILL MOVE EAST/NORTHEAST INTO THE AFTERNOON. WITH DESTABILIZATION
AHEAD OF IT...SCATTERED TO LIKELY CONVECTION SHOULD FILL IN ACRS
OUR EASTERN AREAS. FOR LATER THIS AFTERNOON INTO THIS
EVENING...HIGH RESOLUTION MODELS STILL ARE ADVERTISING A
POTENTIAL PREFRONTAL TROF TO MOVE INTO THE AREA. THIS WILL BECOME
THE FOCUS FOR MORE SHOWERS AND EMBEDDED THUNDERSTORMS. OVERALL
BULK SHEAR WILL BE WEAK...SO ORGANIZATION TO THE CONVECTION WILL
BE LACKING. IN ADDITION...MLCAPES MAY ONLY RANGE FROM 800-1200
J/KG AT PEAK HEATING WITH THE HIGHEST IN THE EAST. ALSO...WITH HIGH
PWATS...DCAPES WILL BE LOW (LACK OF MID LEVEL DRY AIR). ALL IN ALL...
ONLY A MARGINAL RISK FOR SEVERE TODAY WITH PERHAPS GUSTY WINDS
DUE TO PCPN LOADING. FREEZING LEVELS WILL REMAIN HIGH TO KEEP HAIL
SIZE IN CHECK. IF ANYTHING...LOCALLY HEAVY RAINFALL MAY END UP
BEING THE MAIN CONCERN GIVEN HIGH PWATS. HIGHS TODAY WILL BE PCPN
AND CLOUD DEPENDENT WITH THE HIGHER VALUES FAVORING OUR EAST AS
SOME INSOLATION OCCURS BEFORE CLOUDING OVER. WILL CONTINUE WITH
LOWER TO MID 80S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
THIS EVENING THE UPPER LEVEL LOW OVER MINNESOTA WILL START TO PULL
NORTH AS ANOTHER LOW DIVES SOUTH NEAR THE HUDSON BAY. AT THE SAME
TIME A COLD FRONT WILL BE APPROACHING FROM THE WEST. EXPECTING
COVERAGE TO AGAIN INCREASE THIS EVENING AS MODELS ARE HINTING AT
SOME LOW LEVEL CONVERGENCE FROM A LLJ MOVING IN FROM THE
SOUTHWEST. THE MAIN QUESTION WILL BE WHERE AND IF THE JET SETS
UP. ALSO AT 250 MB A SPLITTING JET STRUCTURE CAN BE FOUND AROUND
KENTUCKY/ TENNESSEE JUST SOUTH OF THE AREA. IN NORTHERN OHIO THE
UPPER LEVEL FLOW REMAINS MORE UNIFORM SPATIALLY (MUCH LESS UPPER
LEVEL DIFFLUENCE). DUE TO THE MENTIONED ABOVE HIGH RES MODELS SHOW
MORE COVERAGE IN CONVECTION THROUGH OUR CWA AND SOUTH OF OUR CWA
WHILE A BREAK COULD POSSIBLY EXIST IN NORTHERN OHIO AND MICHIGAN.
PWATS ARE STILL EXPECTED TO BE AROUND 1.90" AHEAD OF THE FRONT
THOUGH AND WITH UPPER LEVEL SUPPORT DECIDED TO LEAVE POP
DISTRIBUTION AS IS. REGARDING SEVERE POTENTIAL... INSTABILITY WILL
WANE AFTER THE SUNSETS WHILE BY FAR THE BEST SPEED SHEAR LIES JUST
BEHIND THE FRONT. LAPSE RATES ALSO DON`T APPEAR PARTICULARLY
FAVORABLE... THUS THE MARGINAL RISK BY SPC SEEMS SUFFICIENT.
TIMING OF THE FRONTAL PASSAGE HAS ALSO BEEN SLOWING THE LAST
COUPLE OF DAYS. THE EURO AND NAM ARE NOW MORE IN AGREEMENT WITH A
SLOWER FRONTAL PASSAGE. THEY HAVE THE FRONT PASSING THROUGH
CINCINNATI AROUND 12Z (8 AM) WHILE CLEARING THE CWA 6 HRS LATER.
BEHIND THE FRONT MUCH LOWER PWAT AIR AND FALLING DEWPOINTS WILL
BE USHERED IN. 850 TEMPS ALSO FALL FROM AROUND 16/ 15 DEGREES C TO
NEAR 11 DEGREES C BY THURSDAY EVENING. THIS WILL KEEP HIGH TEMPS
IN THE MID TO UPPER 70S ACROSS THE REGION THURSDAY.
FRIDAY MORNING HIGH PRESSURE WILL MOVE OVERHEAD ALLOWING FOR
TEMPERATURES TO QUICKLY FALL AND BOTTOM OUT IN THE MID 50S. THE
NAM HAS CONTINUED TO SHOW SOME CIRRUS POSSIBLE ACROSS OUR
SOUTHEASTERN ZONES IN ASSOCIATION WITH A WEAK DISTURBANCE WHILE
THE GFS AND EURO SHOW THE CIRRUS FURTHER EAST. FOR NOW HAVE KEPT
CIRRUS OUT OF THE AREA FRIDAY MORNING ALLOWING FOR MAX RADIATIONAL
COOLING. FRIDAY AFTERNOON WILL BE BEAUTIFUL WITH HIGHS LIKELY
RIGHT AROUND OR JUST BELOW 80 DEGREES AS 850 MB TEMPS REMAIN
AROUND 10 OR 11 DEGREES C. DEWPOINTS WILL ALSO LIKELY MIX OUT
ALLOWING FOR RELATIVE HUMIDITY PERCENTAGES IN THE UPPER 30S.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
THE NEXT SYSTEM WILL APPROACH AND MOVE THROUGH THE REGION SUNDAY
INTO SUNDAY NIGHT. MODELS ARE IN DECENT AGREEMENT WITH THIS SYSTEM
AND THEREFORE WENT WITH LIKELY PRECIPITATION CHANCES. HIGH
PRESSURE AND DRY CONDITIONS WILL RETURN TO THE REGION MONDAY
THROUGH TUESDAY.
HIGH TEMPERATURES ARE GENERALLY EXPECTED TO BE SLIGHTLY BELOW NORMAL
EXCEPT ON SUNDAY WHEN HIGH TEMPERATURES ARE EXPECTED TO BE SLIGHTLY
ABOVE NORMAL.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
A THUNDERSTORM COMPLEX IS MOVING EAST ACROSS SOUTHERN ILLINOIS AND
INTO SOUTHWEST INDIANA ATTM AND WE ARE BEGINNING TO SEE SOME
SCATTERED DEVELOPMENT OUT AHEAD OF IT ACROSS WESTERN KENTUCKY AND
SOUTH CENTRAL INDIANA. THE LATEST HRRR SEEMS TO HAVE A DECENT
HANDLE ON THIS...BUT IS PERHAPS A COUPLE OF HOURS SLOW WITH ITS
POSITIONING. THIS NEW DEVELOPMENT IS IN AN AREA OF BETTER
INSTABILITIES ALONG THE OHIO RIVER SO THINK THIS MAY BECOME THE MORE
DOMINANT PCPN FEATURE OVER THE NEXT HOUR OR TWO. KCVG AND KLUK
SHOULD HAVE THE BEST CHANCE OF BEING AFFECTED BY THIS IN THE NEAR
TERM AS IT CONTINUES TO WORK ITS WAY EASTWARD THROUGH MID MORNING.
THE CONVECTIVE ALLOWING MODELS ARE GENERALLY TRYING TO SHOW AT
LEAST SOME ADDITIONAL SCATTERED DEVELOPMENT ELSEWHERE ACROSS THE
AREA IN ASSOCIATION WITH A PRE FRONTAL TROUGH LATER THIS MORNING
AND INTO EARLY TO MID AFTERNOON. TIMING IS SOMEWHAT DIFFICULT
THOUGH SO WILL GENERALLY HAVE A VCTS THROUGH MUCH OF THE DAY AND
THEN TRY TO INCLUDE SOME TEMPO GROUPS FOR THE MORE FAVORABLE TIME
PERIODS.
WE MAY THEN GET INTO A BIT OF A LULL LATER THIS AFTERNOON INTO
EARLY EVENING BEFORE BETTER FORCING ASSOCIATED WITH THE ACTUAL
FRONT BEGINS TO WORK IN FROM THE WEST. THERE ARE STILL SOME TIMING
DIFFERENCES BETWEEN THE MODELS WITH THE FRONT FOR TONIGHT...BUT
OVERALL EXPECT TO TRANSITION TO MORE WIDESPREAD SHOWERS AND
EMBEDDED THUNDERSTORMS HEADING INTO TONIGHT. PREVAILING CIGS WILL
DROP DOWN INTO MVFR AND THEN PROBABLY IFR AS THE FRONT
APPROACHES/MOVES THROUGH OVERNIGHT.
OUTLOOK...THUNDERSTORMS POSSIBLE SUNDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HAINES
NEAR TERM...HICKMAN
SHORT TERM...HAINES
LONG TERM...NOVAK
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
624 AM EDT WED AUG 19 2015
.SYNOPSIS...
WARM AND HUMID AIR TODAY WILL ALLOW FOR SHOWERS AND THUNDERSTORMS
TO DEVELOP...IN ADVANCE OF A COLD FRONT THAT WILL MOVE THROUGH THE
AREA THURSDAY MORNING. MUCH DRIER CONDITIONS ARE EXPECTED ON
THURSDAY AND FRIDAY...WITH SLIGHTLY COOLER TEMPERATURES AND LESS
HUMIDITY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
EARLIER LINE OF SHOWERS AND THUNDERSTORMS OUT IN INDIANA HAS ALL
BUT FIZZLED THIS MORNING WITH MORE CONVECTION CURRENTLY FIRING IN
SOUTHERN ILLINOIS. HIGH RES MODELS ARE SHOWING THIS CONVECTION
CONTINUING TO WEAKEN AS IT PROGRESSES EASTWARDS BUT MAKING IT TO
CINCINNATI LATE MORNING. FORECAST SOUNDINGS FOR THIS AFTERNOON
SHOW MOISTURE LEVELS QUICKLY RISING TO NEAR 1.90" WITH K INDEX
VALUES PEAKING IN THE UPPER 30S. SHEAR VALUES REMAIN WEAK THIS
AFTERNOON WITH SFC TO 6 KM VALUES ONLY AROUND 10 KTS. CAPE VALUES
ON BOTH THE GFS AND NAM ARE AROUND 1500 J/KG ON AVERAGE FOR THIS
AFTERNOON. IN THE MID LEVELS POCKETS OF PVA ARE FORECASTED TO MOVE
ACROSS THE REGION THIS AFTERNOON WHICH WILL SUPPORT POCKETS OF
LIFT. HIGH RES MODELS ARE MIXED ON THE AMOUNT OF COVERAGE. THERE
DOES APPEAR TO BE A WEAK BOUNDARY THAT SETS UP THIS AFTERNOON SOME
WHERE ACROSS THE CWA THOUGH. GIVEN THE ABUNDANT MOISTURE...
SUFFICIENT INSTABILITY AND LIFT HAVE PUSHED POPS TO LIKELY THIS
AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
THIS EVENING THE UPPER LEVEL LOW OVER MINNESOTA WILL START TO PULL
NORTH AS ANOTHER LOW DIVES SOUTH NEAR THE HUDSON BAY. AT THE SAME
TIME A COLD FRONT WILL BE APPROACHING FROM THE WEST. EXPECTING
COVERAGE TO AGAIN INCREASE THIS EVENING AS MODELS ARE HINTING AT
SOME LOW LEVEL CONVERGENCE FROM A LLJ MOVING IN FROM THE
SOUTHWEST. THE MAIN QUESTION WILL BE WHERE AND IF THE JET SETS
UP. ALSO AT 250 MB A SPLITTING JET STRUCTURE CAN BE FOUND AROUND
KENTUCKY/ TENNESSEE JUST SOUTH OF THE AREA. IN NORTHERN OHIO THE
UPPER LEVEL FLOW REMAINS MORE UNIFORM SPATIALLY (MUCH LESS UPPER
LEVEL DIFFLUENCE). DUE TO THE MENTIONED ABOVE HIGH RES MODELS SHOW
MORE COVERAGE IN CONVECTION THROUGH OUR CWA AND SOUTH OF OUR CWA
WHILE A BREAK COULD POSSIBLY EXIST IN NORTHERN OHIO AND MICHIGAN.
PWATS ARE STILL EXPECTED TO BE AROUND 1.90" AHEAD OF THE FRONT
THOUGH AND WITH UPPER LEVEL SUPPORT DECIDED TO LEAVE POP
DISTRIBUTION AS IS. REGARDING SEVERE POTENTIAL... INSTABILITY WILL
WANE AFTER THE SUNSETS WHILE BY FAR THE BEST SPEED SHEAR LIES JUST
BEHIND THE FRONT. LAPSE RATES ALSO DON`T APPEAR PARTICULARLY
FAVORABLE... THUS THE MARGINAL RISK BY SPC SEEMS SUFFICIENT.
TIMING OF THE FRONTAL PASSAGE HAS ALSO BEEN SLOWING THE LAST
COUPLE OF DAYS. THE EURO AND NAM ARE NOW MORE IN AGREEMENT WITH A
SLOWER FRONTAL PASSAGE. THEY HAVE THE FRONT PASSING THROUGH
CINCINNATI AROUND 12Z (8 AM) WHILE CLEARING THE CWA 6 HRS LATER.
BEHIND THE FRONT MUCH LOWER PWAT AIR AND FALLING DEWPOINTS WILL
BE USHERED IN. 850 TEMPS ALSO FALL FROM AROUND 16/ 15 DEGREES C TO
NEAR 11 DEGREES C BY THURSDAY EVENING. THIS WILL KEEP HIGH TEMPS
IN THE MID TO UPPER 70S ACROSS THE REGION THURSDAY.
FRIDAY MORNING HIGH PRESSURE WILL MOVE OVERHEAD ALLOWING FOR
TEMPERATURES TO QUICKLY FALL AND BOTTOM OUT IN THE MID 50S. THE
NAM HAS CONTINUED TO SHOW SOME CIRRUS POSSIBLE ACROSS OUR
SOUTHEASTERN ZONES IN ASSOCIATION WITH A WEAK DISTURBANCE WHILE
THE GFS AND EURO SHOW THE CIRRUS FURTHER EAST. FOR NOW HAVE KEPT
CIRRUS OUT OF THE AREA FRIDAY MORNING ALLOWING FOR MAX RADIATIONAL
COOLING. FRIDAY AFTERNOON WILL BE BEAUTIFUL WITH HIGHS LIKELY
RIGHT AROUND OR JUST BELOW 80 DEGREES AS 850 MB TEMPS REMAIN
AROUND 10 OR 11 DEGREES C. DEWPOINTS WILL ALSO LIKELY MIX OUT
ALLOWING FOR RELATIVE HUMIDITY PERCENTAGES IN THE UPPER 30S.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
THE NEXT SYSTEM WILL APPROACH AND MOVE THROUGH THE REGION SUNDAY
INTO SUNDAY NIGHT. MODELS ARE IN DECENT AGREEMENT WITH THIS SYSTEM
AND THEREFORE WENT WITH LIKELY PRECIPITATION CHANCES. HIGH
PRESSURE AND DRY CONDITIONS WILL RETURN TO THE REGION MONDAY
THROUGH TUESDAY.
HIGH TEMPERATURES ARE GENERALLY EXPECTED TO BE SLIGHTLY BELOW NORMAL
EXCEPT ON SUNDAY WHEN HIGH TEMPERATURES ARE EXPECTED TO BE SLIGHTLY
ABOVE NORMAL.
&&
.AVIATION /10Z WEDNESDAY THROUGH SUNDAY/...
A THUNDERSTORM COMPLEX IS MOVING EAST ACROSS SOUTHERN ILLINOIS AND
INTO SOUTHWEST INDIANA ATTM AND WE ARE BEGINNING TO SEE SOME
SCATTERED DEVELOPMENT OUT AHEAD OF IT ACROSS WESTERN KENTUCKY AND
SOUTH CENTRAL INDIANA. THE LATEST HRRR SEEMS TO HAVE A DECENT
HANDLE ON THIS...BUT IS PERHAPS A COUPLE OF HOURS SLOW WITH ITS
POSITIONING. THIS NEW DEVELOPMENT IS IN AN AREA OF BETTER
INSTABILITIES ALONG THE OHIO RIVER SO THINK THIS MAY BECOME THE MORE
DOMINANT PCPN FEATURE OVER THE NEXT HOUR OR TWO. KCVG AND KLUK
SHOULD HAVE THE BEST CHANCE OF BEING AFFECTED BY THIS IN THE NEAR
TERM AS IT CONTINUES TO WORK ITS WAY EASTWARD THROUGH MID MORNING.
THE CONVECTIVE ALLOWING MODELS ARE GENERALLY TRYING TO SHOW AT
LEAST SOME ADDITIONAL SCATTERED DEVELOPMENT ELSEWHERE ACROSS THE
AREA IN ASSOCIATION WITH A PRE FRONTAL TROUGH LATER THIS MORNING
AND INTO EARLY TO MID AFTERNOON. TIMING IS SOMEWHAT DIFFICULT
THOUGH SO WILL GENERALLY HAVE A VCTS THROUGH MUCH OF THE DAY AND
THEN TRY TO INCLUDE SOME TEMPO GROUPS FOR THE MORE FAVORABLE TIME
PERIODS.
WE MAY THEN GET INTO A BIT OF A LULL LATER THIS AFTERNOON INTO
EARLY EVENING BEFORE BETTER FORCING ASSOCIATED WITH THE ACTUAL
FRONT BEGINS TO WORK IN FROM THE WEST. THERE ARE STILL SOME TIMING
DIFFERENCES BETWEEN THE MODELS WITH THE FRONT FOR TONIGHT...BUT
OVERALL EXPECT TO TRANSITION TO MORE WIDESPREAD SHOWERS AND
EMBEDDED THUNDERSTORMS HEADING INTO TONIGHT. PREVAILING CIGS WILL
DROP DOWN INTO MVFR AND THEN PROBABLY IFR AS THE FRONT
APPROACHES/MOVES THROUGH OVERNIGHT.
OUTLOOK...THUNDERSTORMS POSSIBLE SUNDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HAINES
NEAR TERM...HAINES
SHORT TERM...HAINES
LONG TERM...NOVAK
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS NORMAN OK
100 PM CDT WED AUG 19 2015
.DISCUSSION...
THE 18Z AVIATION DISCUSSION IS BELOW.
&&
.AVIATION...
ONGOING SHOWERS AND THUNDERSTORMS WILL CONTINUE TO AFFECT
KOUN/KLAW/KSPS THIS AFTERNOON. EXPECT PRECIPITATION TO END FROM
NORTH TO SOUTH...WITH PRECIPITATION ENDING AT KSPS BY 23Z.
PERIODS OF MVFR CONDITIONS CAN BE EXPECTED AT THESE SITES.
OTHERWISE...GUSTY NORTHERLY WINDS SHOULD SUBSIDE TO LIGHT AND
VARIABLE WITH CLEARING SKIES OVERNIGHT.
MAHALE
&&
.PREV DISCUSSION... /ISSUED 1026 AM CDT WED AUG 19 2015/
UPDATE...
ADJUSTED PRECIP/WX THROUGH THE AFTERNOON... MINOR ADJUSTMENTS TO
TEMPS...
DISCUSSION...
SHOWERS AND THUNDERSTORMS CONTINUE TO DECREASE IN COVERAGE ACROSS
S/SWRN OK AND WRN N TX THIS MORNING. THIS TREND LOOKS TO CONTINUE
THROUGH THE AFTN AS THE H700 SHORT WAVE PUSHES EAST... DECREASING
MID-LEVEL SUPPORT. BUFR SOUNDINGS SUGGEST DECREASING SHEAR AND
INSTABILITY ENVIRONMENT WILL CONTINUE TO EVOLVE ACROSS SRN OK/WRN
N TX THROUGH THE EARLY AFTN. HRRR HAS SHOWN RELATIVELY DECENT
CONTINUITY THIS AM... WITH SHOWERS AND ISOLATED THUNDER LINGERING
THROUGH THE AFTN AND INTO THE EVENING ACROSS SOUTH CENTRAL OK.
ADJUSTED HIGH TEMPS SLIGHTLY FOR THIS AFTN... BRINGING OKC TO 67.
THROUGH 10AM... ALREADY REACHED 65... AND BEGINNING TO SEE SOME
BREAKS IN THE CLOUDS ACROSS NWRN OK. IF A FEW BREAKS DEVELOP OVER
CENTRAL OK THIS AFTN... TEMPS COULD EASILY MOVE INTO THE UPPER
60S FOR HIGHS... SO ENJOY.
JTK
PREV DISCUSSION... /ISSUED 628 AM CDT WED AUG 19 2015/
DISCUSSION...
THE 12Z AVIATION DISCUSSION FOLLOWS....
AVIATION...
WIDESPREAD RA AND TSRA WILL CONTINUE ALONG...AND IN THE GENERAL
VICINITY OF...A STRONG COLD FRONT ACROSS OK AND N TX. SCT SHRA
WILL ALSO OCCUR WELL INTO THE COOLER AIR OVER N OK UNTIL HIGH
PRESSURE FILLS IN THIS AFTERNOON/EVENING. SCATTERED AREAS OF LOW
CLOUDS AND TEMPORARY LOW VISIBILITIES WILL OCCUR NEAR THE NUMEROUS
TSRA. AS HIGH PRESSURE CONTINUES TO BUILD INTO OK/N TX THIS
EVENING AND OVERNIGHT...THE RAIN WILL BECOME LIMITED TO THE FAR
S...AND SKIES WILL BEGIN TO CLEAR IN THE N. BY SUNRISE...EXPECT
VFR CONDITIONS AND LIGHT WINDS. AREAS THAT CLEAR BEFORE SUNRISE
MAY DEVELOP GROUND FOG.
CMS
PREV DISCUSSION... /ISSUED 409 AM CDT WED AUG 19 2015/
DISCUSSION...
AN UNSEASONABLY STRONG COLD FRONT EXTENDED FROM EAST-CENTRAL TO
SOUTHWEST OKLAHOMA EARLY THIS MORNING...WITH AN OUTFLOW BOUNDARY
EXTENDING FARTHER TO THE SOUTH...ROUGHLY FROM SHAWNEE TO WICHITA
FALLS. MUCH COOLER AND DRIER AIR WAS OVER KANSAS...AND WILL SHIFT
SOUTH TODAY AND TONIGHT.
THE COMBINED EFFECTS OF THE COOLER/DRIER AIR...AND RAIN FALLING
THROUGH IT...WILL RESULT IN TEMPERATURES THAT ARE VERY COOL FOR
THIS TIME OF YEAR. RECORD LOW MAXIMUM TEMPERATURES ARE LIKELY
ACROSS MUCH OF THE REGION TODAY...AND RECORD LOW MINIMUM
TEMPERATURES ARE LIKELY TOMORROW MORNING. THE BALANCE OF THE
VARIOUS ELEMENTS AFFECTING TEMPERATURE TODAY IS A MAJOR
CHALLENGE...AND TEMPERATURE FORECASTS TODAY SHOULD BE CONSIDERED
AS APPROXIMATE...ESPECIALLY HOURLY TEMPERATURES.
RAIN CHANCES ARE ALSO PROBLEMATIC TODAY...AS THE EVOLUTION OF THE
CURRENT MCS IS UNCLEAR. HAVE GENERALLY FORECAST POPS ABOVE THE
OVERALL MODEL GUIDANCE VALUES...ON THE ASSUMPTION THAT THE MCS
WILL HOLD TOGETHER AT LEAST THROUGH MID-MORNING.
AFTER A DAY OF COOL DRY WEATHER...THE WARM/HUMID AIR WILL RETURN
NORTH...BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS
FRIDAY. A SERIES OF DISTURBANCES WILL KEEP RAIN IN THE FORECAST
UNTIL EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 69 54 81 61 / 100 10 0 10
HOBART OK 70 54 84 63 / 80 10 0 20
WICHITA FALLS TX 74 57 85 66 / 100 20 0 20
GAGE OK 75 53 82 62 / 30 10 0 10
PONCA CITY OK 73 53 82 61 / 60 10 0 10
DURANT OK 82 59 82 65 / 80 50 10 20
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
04/67/10
AREA FORECAST DISCUSSION
NWS NORMAN OK
1026 AM CDT WED AUG 19 2015
.UPDATE...
ADJUSTED PRECIP/WX THROUGH THE AFTERNOON... MINOR ADJUSTMENTS TO
TEMPS...
&&
.DISCUSSION...
SHOWERS AND THUNDERSTORMS CONTINUE TO DECREASE IN COVERAGE ACROSS
S/SWRN OK AND WRN N TX THIS MORNING. THIS TREND LOOKS TO CONTINUE
THROUGH THE AFTN AS THE H700 SHORT WAVE PUSHES EAST... DECREASING
MID-LEVEL SUPPORT. BUFR SOUNDINGS SUGGEST DECREASING SHEAR AND
INSTABILITY ENVIRONMENT WILL CONTINUE TO EVOLVE ACROSS SRN OK/WRN
N TX THROUGH THE EARLY AFTN. HRRR HAS SHOWN RELATIVELY DECENT
CONTINUITY THIS AM... WITH SHOWERS AND ISOLATED THUNDER LINGERING
THROUGH THE AFTN AND INTO THE EVENING ACROSS SOUTH CENTRAL OK.
ADJUSTED HIGH TEMPS SLIGHTLY FOR THIS AFTN... BRINGING OKC TO 67.
THROUGH 10AM... ALREADY REACHED 65... AND BEGINNING TO SEE SOME
BREAKS IN THE CLOUDS ACROSS NWRN OK. IF A FEW BREAKS DEVELOP OVER
CENTRAL OK THIS AFTN... TEMPS COULD EASILY MOVE INTO THE UPPER
60S FOR HIGHS... SO ENJOY.
JTK
&&
.PREV DISCUSSION... /ISSUED 628 AM CDT WED AUG 19 2015/
DISCUSSION...
THE 12Z AVIATION DISCUSSION FOLLOWS....
AVIATION...
WIDESPREAD RA AND TSRA WILL CONTINUE ALONG...AND IN THE GENERAL
VICINITY OF...A STRONG COLD FRONT ACROSS OK AND N TX. SCT SHRA
WILL ALSO OCCUR WELL INTO THE COOLER AIR OVER N OK UNTIL HIGH
PRESSURE FILLS IN THIS AFTERNOON/EVENING. SCATTERED AREAS OF LOW
CLOUDS AND TEMPORARY LOW VISIBILITIES WILL OCCUR NEAR THE NUMEROUS
TSRA. AS HIGH PRESSURE CONTINUES TO BUILD INTO OK/N TX THIS
EVENING AND OVERNIGHT...THE RAIN WILL BECOME LIMITED TO THE FAR
S...AND SKIES WILL BEGIN TO CLEAR IN THE N. BY SUNRISE...EXPECT
VFR CONDITIONS AND LIGHT WINDS. AREAS THAT CLEAR BEFORE SUNRISE
MAY DEVELOP GROUND FOG.
CMS
PREV DISCUSSION... /ISSUED 409 AM CDT WED AUG 19 2015/
DISCUSSION...
AN UNSEASONABLY STRONG COLD FRONT EXTENDED FROM EAST-CENTRAL TO
SOUTHWEST OKLAHOMA EARLY THIS MORNING...WITH AN OUTFLOW BOUNDARY
EXTENDING FARTHER TO THE SOUTH...ROUGHLY FROM SHAWNEE TO WICHITA
FALLS. MUCH COOLER AND DRIER AIR WAS OVER KANSAS...AND WILL SHIFT
SOUTH TODAY AND TONIGHT.
THE COMBINED EFFECTS OF THE COOLER/DRIER AIR...AND RAIN FALLING
THROUGH IT...WILL RESULT IN TEMPERATURES THAT ARE VERY COOL FOR
THIS TIME OF YEAR. RECORD LOW MAXIMUM TEMPERATURES ARE LIKELY
ACROSS MUCH OF THE REGION TODAY...AND RECORD LOW MINIMUM
TEMPERATURES ARE LIKELY TOMORROW MORNING. THE BALANCE OF THE
VARIOUS ELEMENTS AFFECTING TEMPERATURE TODAY IS A MAJOR
CHALLENGE...AND TEMPERATURE FORECASTS TODAY SHOULD BE CONSIDERED
AS APPROXIMATE...ESPECIALLY HOURLY TEMPERATURES.
RAIN CHANCES ARE ALSO PROBLEMATIC TODAY...AS THE EVOLUTION OF THE
CURRENT MCS IS UNCLEAR. HAVE GENERALLY FORECAST POPS ABOVE THE
OVERALL MODEL GUIDANCE VALUES...ON THE ASSUMPTION THAT THE MCS
WILL HOLD TOGETHER AT LEAST THROUGH MID-MORNING.
AFTER A DAY OF COOL DRY WEATHER...THE WARM/HUMID AIR WILL RETURN
NORTH...BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS
FRIDAY. A SERIES OF DISTURBANCES WILL KEEP RAIN IN THE FORECAST
UNTIL EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 69 54 81 61 / 100 10 0 10
HOBART OK 70 54 84 63 / 80 10 0 20
WICHITA FALLS TX 74 57 85 66 / 100 20 0 20
GAGE OK 75 53 82 62 / 30 10 0 10
PONCA CITY OK 73 53 82 61 / 60 10 0 10
DURANT OK 82 59 82 65 / 80 50 10 20
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1151 PM EDT THU AUG 20 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION LATER THIS EVENING AND
OVERNIGHT. DRIER AIR WILL MOVE IN FROM THE WEST LATER
TONIGHT...WITH FAIR WEATHER AND COMFORTABLE HUMIDITY CONTINUING
FOR THIS WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
THE WEAK SURFACE COLD FRONT JUST PASSED STATE COLLEGE WITH A WEAK
WIND SHIFT AND DEWPOINTS STARTING TO FADE AWAY. THE LAST OF THE
RAIN IS LEAVING THE EASTERN TIP OF SCHUYLKILL COUNTY AND WILL
CONTINUE OFF TO THE EAST.
AFTER A SOAKING RAIN OVER MOST OF THE AREA...IT LOOKS LIKE A GOOD
SET UP FOR A FOGGY NIGHT TO DEVELOP AS SKIES CLEAR AND WINDS DROP
OFF AND BECOME LIGHT.
LOWS EARLY FRIDAY WILL VARY FROM THE L50S ACROSS THE NW MTNS...TO
THE L-M 60S IN THE FAR SE.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
THE FRONT IS EXPECTED TO SLOW AND EVENTUALLY STALL OUT AS IT
NEARS THE MID ATLC COAST...IN RESPONSE TO STRONG N. ATLC UPPER
RIDGE AND UPPER/NON-TROPICAL LOW NEAR BERMUDA. THERE IS SOME
CONCERN THAT THE EASTERN MOST PORTIONS OF OUR FORECAST ZONES
COULD SEE LINGERING CLOUDS AND A SHOWER....BUT I USED THE HRRR TO
DOWNPLAY THIS SCENARIO AS LOW PW AIR MOVES IN.
SKIES SHOULD BECOME MOSTLY SUNNY ACROSS CENTRAL AND SOUTHERN
PENN...WHILE PERIODS OF BKN-OVC STRATO CU WILL LIKELY FORM ACROSS
THE NRN MTNS OF PENN WITH EVEN A FEW SPRINKLES POSSIBLE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
A RELATIVELY QUIET STRETCH OF WEATHER IS IN STORE THROUGH THIS
WEEKEND AND MUCH OF NEXT WEEK. PWATS WILL DROP TO -1SD FRI AND
REMAIN THAT WAY THRU THE WEEKEND...WHICH WILL BE A NICE CHANGE FROM
THE MUGGY AIRMASS WE SAW MUCH OF THE PAST WEEK.
IN ALL...THE WEEKEND LOOKS PLEASANT WITH LOW HUMIDITY AND
TEMPERATURES RUNNING A FEW DEGREES BELOW LATE-AUGUST NORMALS. THE
ONLY POTENTIAL FLY IN THE OINTMENT IS A WEAK AREA OF LOW PRESSURE
OFF THE MID-ATLANTIC COAST THAT COULD TRY TO PUSH A BIT OF
CLOUDINESS WESTWARD INTO EASTERN PA ON SUNDAY.
A WEAKENING COLD FRONT WILL CROSS THE COMMONWEALTH ON
MONDAY...ACCOMPANIED BY AN OUTSIDE CHC FOR A FEW SHRA/TSRA.
BEHIND THE FRONT...THE MIDDLE OF NEXT WEEK SHOULD SEE A RETURN TO
LOW HUMIDITY AND SLIGHTLY BELOW NORMAL TEMPS.
&&
.AVIATION /04Z FRIDAY THROUGH TUESDAY/...
GIVEN THE COPIOUS AMOUNTS OF WIDESPREAD PRECIPITATION THIS
AFTERNOON AND EVENING AND THE CLEARING SKIES AND WEAK FLOW EXPECT
FOR LOW STRATOCU AND PATCHY DENSE FOG TO DEVELOP OVERNIGHT. IN THE
11U-3.9U THERE IS A LINE OF DRY AIR MOVING IN WHICH WILL LIMIT AND
PREVENT FOG/LOW STRATOCU DEVELOPMENT. IPT HAS DECOUPLED WITH LIFR
CIGS AND VSBYS. GIVEN THE WESTERLY FLOW EXPECT WESTERN AND CENTRAL
TAF SITES TO HAVE PERIODS OF IFR FROM 06Z TO 13Z WITH MVFR TO
POSSIBLY VFR IN THE INTERIM. AS THE REGION MIXES OUT AFTER
SUNRISE AND DRY AIR MIXES DOWN ANY AREAS OF 1/2SM VSBY FOG WILL
TEND TO MVFR BETWEEN 12Z TO 15Z BEFORE BECOMING VFR ACROSS ALL OF
CENTRAL AND SOUTHERN PENN.
OUTLOOK...
SAT-MON...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LAMBERT/STEINBUGL
LONG TERM...EVANEGO
AVIATION...LAMBERT/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1048 PM EDT THU AUG 20 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION LATER THIS EVENING AND
OVERNIGHT. DRIER AIR WILL MOVE IN FROM THE WEST LATER
TONIGHT...WITH FAIR WEATHER AND COMFORTABLE HUMIDITY CONTINUING
FOR THIS WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
THE WEAK SURFACE COLD FRONT JUST PASSED STATE COLLEGE WITH A WEAK
WIND SHIFT AND DEWPOINTS STARTING TO FADE AWAY. THE LAST OF THE
RAIN IS LEAVING THE EASTERN TIP OF SCHUYLKILL COUNTY AND WILL
CONTINUE OFF TO THE EAST.
AFTER A SOAKING RAIN OVER MOST OF THE AREA...IT LOOKS LIKE A GOOD
SET UP FOR A FOGGY NIGHT TO DEVELOP AS SKIES CLEAR AND WINDS DROP
OFF AND BECOME LIGHT.
LOWS EARLY FRIDAY WILL VARY FROM THE L50S ACROSS THE NW MTNS...TO
THE L-M 60S IN THE FAR SE.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
THE FRONT IS EXPECTED TO SLOW AND EVENTUALLY STALL OUT AS IT
NEARS THE MID ATLC COAST...IN RESPONSE TO STRONG N. ATLC UPPER
RIDGE AND UPPER/NON-TROPICAL LOW NEAR BERMUDA. THERE IS SOME
CONCERN THAT THE EASTERN MOST PORTIONS OF OUR FORECAST ZONES
COULD SEE LINGERING CLOUDS AND A SHOWER....BUT I USED THE HRRR TO
DOWNPLAY THIS SCENARIO AS LOW PW AIR MOVES IN.
SKIES SHOULD BECOME MOSTLY SUNNY ACROSS CENTRAL AND SOUTHERN
PENN...WHILE PERIODS OF BKN-OVC STRATO CU WILL LIKELY FORM ACROSS
THE NRN MTNS OF PENN WITH EVEN A FEW SPRINKLES POSSIBLE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
A RELATIVELY QUIET STRETCH OF WEATHER IS IN STORE THROUGH THIS
WEEKEND AND MUCH OF NEXT WEEK. PWATS WILL DROP TO -1SD FRI AND
REMAIN THAT WAY THRU THE WEEKEND...WHICH WILL BE A NICE CHANGE FROM
THE MUGGY AIRMASS WE SAW MUCH OF THE PAST WEEK.
IN ALL...THE WEEKEND LOOKS PLEASANT WITH LOW HUMIDITY AND
TEMPERATURES RUNNING A FEW DEGREES BELOW LATE-AUGUST NORMALS. THE
ONLY POTENTIAL FLY IN THE OINTMENT IS A WEAK AREA OF LOW PRESSURE
OFF THE MID-ATLANTIC COAST THAT COULD TRY TO PUSH A BIT OF
CLOUDINESS WESTWARD INTO EASTERN PA ON SUNDAY.
A WEAKENING COLD FRONT WILL CROSS THE COMMONWEALTH ON
MONDAY...ACCOMPANIED BY AN OUTSIDE CHC FOR A FEW SHRA/TSRA.
BEHIND THE FRONT...THE MIDDLE OF NEXT WEEK SHOULD SEE A RETURN TO
LOW HUMIDITY AND SLIGHTLY BELOW NORMAL TEMPS.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
AS SHOWERS CONTINUE TO MOVE EASTWARD AND VACATE THE
REGION...CLEARING SKIES AND WEAKENING WINDS WILL OVERTAKE THE
REGION.
GIVEN THE COPIOUS AMOUNTS OF WIDESPREAD PRECIPITATION THIS
AFTERNOON AND EVENING AND THE CLEARING SKIES AND WEAK FLOW EXPECT
FOR LOW STRATOCU AND PATCHY DENSE FOG TO DEVELOP OVERNIGHT.
LNS HAS ALREADY FORMED A IFR CIGS AND GIVEN THE AMOUNT OF RAIN IT
RECEIVED THIS SHOULD CONTINUE OVERNIGHT AND INTO MID MORNING.
MOST SITES WILL SEE CONDITIONS TO DETERIORATE BETWEEN NOW AND 06Z
AND THEN GO IFR BETWEEN 06Z TO 13Z...BEFORE IMPROVING AFTER
SUNRISE AS THE REGION DECOUPLES. AREAS OF 1/2SM VSBY FOG ARE
POSSIBLE...ESPECIALLY AT UNV...IPT...LNS AND MDT. THE ONLY CAVEAT
TO LNS IS IF THE WINDS PERSIST.
DRIER WESTERLY FLOW WILL WORK IN TOMORROW AND THEN VFR ACROSS
ALL OF CENTRAL AND SOUTHERN PENN. A FEW PERIODS OF HIGH END MVFR
STRATOCU CIGS POSSIBLE INVOF KBFD FRIDAY.
OUTLOOK...
SAT-MON...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LAMBERT/STEINBUGL
LONG TERM...EVANEGO
AVIATION...LAMBERT/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
902 PM EDT THU AUG 20 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION THIS EVENING AND
OVERNIGHT. IMPROVING CONDITIONS FROM WEST TO EAST ARE EXPECTED TO
BEGIN LATER TONIGHT...WITH FAIR WEATHER AND COMFORTABLE HUMIDITY
CONTINUING FOR THIS WEEKEND.
&&
.NEAR TERM /UNTIL MIDNIGHT TONIGHT/...
THE BACK EDGE OF THE STEADY AND HEAVY RAIN SHIELD IS MOVING THROUGH
MY EASTERN ZONES AND WILL CONTINUE OFF TO THE EAST OVER THE NEXT
SEVERAL HOURS. THE HRRR HAS US PRETTY MUCH RAIN FREE BY 03Z/11PM
AND THIS LOOKS REASONABLE. IT LOOKS LIKE A GOOD SET UP FOR A FOGGY
NIGHT TO DEVELOP AS SKIES CLEAR AND WINDS DROP OFF AND BECOME
LIGHT.
LOWS EARLY FRIDAY WILL VARY FROM THE L50S ACROSS THE NW MTNS...TO
THE L-M 60S IN THE FAR SE.
&&
.SHORT TERM /MIDNIGHT THROUGH 6 PM FRIDAY/...
THE FRONT IS EXPECTED TO SLOW AND EVENTUALLY STALL OUT AS IT
NEARS THE MID ATLC COAST...IN RESPONSE TO STRONG N. ATLC UPPER
RIDGE AND UPPER/NON-TROPICAL LOW NEAR BERMUDA. THERE IS SOME
CONCERN THAT THE EASTERN MOST PORTIONS OF OUR FORECAST ZONES
COULD SEE LINGERING CLOUDS AND A SHOWER EVEN AFTER MIDNIGHT....BUT
I USED THE HRRR TO DOWNPLAY THIS SCENARIO AS LOW PW AIR MOVES IN.
SKIES SHOULD BECOME MOSTLY SUNNY ACROSS CENTRAL AND SOUTHERN
PENN...WHILE PERIODS OF BKN-OVC STRATO CU WILL LIKELY FORM ACROSS
THE NRN MTNS OF PENN WITH EVEN A FEW SPRINKLES POSSIBLE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
A RELATIVELY QUIET STRETCH OF WEATHER IS IN STORE THROUGH THIS
WEEKEND AND MUCH OF NEXT WEEK. PWATS WILL DROP TO -1SD FRI AND
REMAIN THAT WAY THRU THE WEEKEND...WHICH WILL BE A NICE CHANGE FROM
THE MUGGY AIRMASS WE SAW MUCH OF THE PAST WEEK.
IN ALL...THE WEEKEND LOOKS PLEASANT WITH LOW HUMIDITY AND
TEMPERATURES RUNNING A FEW DEGREES BELOW LATE-AUGUST NORMALS. THE
ONLY POTENTIAL FLY IN THE OINTMENT IS A WEAK AREA OF LOW PRESSURE
OFF THE MID-ATLANTIC COAST THAT COULD TRY TO PUSH A BIT OF
CLOUDINESS WESTWARD INTO EASTERN PA ON SUNDAY.
A WEAKENING COLD FRONT WILL CROSS THE COMMONWEALTH ON
MONDAY...ACCOMPANIED BY AN OUTSIDE CHC FOR A FEW SHRA/TSRA.
BEHIND THE FRONT...THE MIDDLE OF NEXT WEEK SHOULD SEE A RETURN TO
LOW HUMIDITY AND SLIGHTLY BELOW NORMAL TEMPS.
&&
.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
AS SHOWERS CONTINUE TO MOVE EASTWARD AND VACATE THE
REGION...CLEARING SKIES AND WEAKENING WINDS WILL OVERTAKE THE
REGION.
GIVEN THE COPIOUS AMOUNTS OF WIDESPREAD PRECIPITATION THIS
AFTERNOON AND EVENING AND THE CLEARING SKIES AND WEAK FLOW EXPECT
FOR LOW STRATOCU AND PATCHY DENSE FOG TO DEVELOP OVERNIGHT.
LNS HAS ALREADY FORMED A IFR CIGS AND GIVEN THE AMOUNT OF RAIN IT
RECEIVED THIS SHOULD CONTINUE OVERNIGHT AND INTO MID MORNING.
MOST SITES WILL SEE CONDITIONS TO DETERIORATE BETWEEN NOW AND 06Z
AND THEN GO IFR BETWEEN 06Z TO 13Z...BEFORE IMPROVING AFTER
SUNRISE AS THE REGION DECOUPLES. AREAS OF 1/2SM VSBY FOG ARE
POSSIBLE...ESPECIALLY AT UNV...IPT...LNS AND MDT. THE ONLY CAVEAT
TO LNS IS IF THE WINDS PERSIST.
DRIER WESTERLY FLOW WILL WORK IN TOMORROW AND THEN VFR ACROSS
ALL OF CENTRAL AND SOUTHERN PENN. A FEW PERIODS OF HIGH END MVFR
STRATOCU CIGS POSSIBLE INVOF KBFD FRIDAY.
OUTLOOK...
SAT-MON...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR PAZ057>059-
063>066.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...LAMBERT/STEINBUGL
LONG TERM...EVANEGO
AVIATION...CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
802 PM EDT THU AUG 20 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION THIS EVENING AND
OVERNIGHT. IMPROVING CONDITIONS FROM WEST TO EAST ARE EXPECTED TO
BEGIN LATER TONIGHT...WITH FAIR WEATHER AND COMFORTABLE HUMIDITY
CONTINUING FOR THIS WEEKEND.
&&
.NEAR TERM /UNTIL MIDNIGHT TONIGHT/...
THE BACK EDGE OF THE STEADY AND HEAVY RAIN SHIELD IS MOVING THROUGH
MY EASTERN ZONES AND WILL CONTINUE OFF TO THE EAST OVER THE NEXT
SEVERAL HOURS. THE HRRR HAS US PRETTY MUCH RAIN FREE BY 03Z/11PM
AND THIS LOOKS REASONABLE. IT LOOKS LIKE A GOOD SET UP FOR A FOGGY
NIGHT TO DEVELOP AS SKIES CLEAR AND WINDS DROP OFF AND BECOME
LIGHT.
LOWS EARLY FRIDAY WILL VARY FROM THE L50S ACROSS THE NW MTNS...TO
THE L-M 60S IN THE FAR SE.
&&
.SHORT TERM /MIDNIGHT THROUGH 6 PM FRIDAY/...
THE FRONT IS EXPECTED TO SLOW AND EVENTUALLY STALL OUT AS IT
NEARS THE MID ATLC COAST...IN RESPONSE TO STRONG N. ATLC UPPER
RIDGE AND UPPER/NON-TROPICAL LOW NEAR BERMUDA. THERE IS SOME
CONCERN THAT THE EASERNMOST PORTIONS OF OUR FORECAST ZONES COULD
SEE LINGERING CLOUDS AND A SHOWER EVEN AFTER MIDNIGHT....BUT I
USED THE HRRR TO DOWNPLAY THIS SCENARIO AS LOW PW AIR MOVES IN.
SKIES SHOULD BECOME MOSTLY SUNNY ACROSS CENTRAL AND SOUTHERN
PENN...WHILE PERIODS OF BKN-OVC STRATO CU WILL LIKELY FORM ACROSS
THE NRN MTNS OF PENN WITH EVEN A FEW SPRINKLES POSSIBLE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
A RELATIVELY QUIET STRETCH OF WEATHER IS IN STORE THROUGH THIS
WEEKEND AND MUCH OF NEXT WEEK. PWATS WILL DROP TO -1SD FRI AND
REMAIN THAT WAY THRU THE WEEKEND...WHICH WILL BE A NICE CHANGE FROM
THE MUGGY AIRMASS WE SAW MUCH OF THE PAST WEEK.
IN ALL...THE WEEKEND LOOKS PLEASANT WITH LOW HUMIDITY AND
TEMPERATURES RUNNING A FEW DEGREES BELOW LATE-AUGUST NORMALS. THE
ONLY POTENTIAL FLY IN THE OINTMENT IS A WEAK AREA OF LOW PRESSURE
OFF THE MID-ATLANTIC COAST THAT COULD TRY TO PUSH A BIT OF
CLOUDINESS WESTWARD INTO EASTERN PA ON SUNDAY.
A WEAKENING COLD FRONT WILL CROSS THE COMMONWEALTH ON
MONDAY...ACCOMPANIED BY AN OUTSIDE CHC FOR A FEW SHRA/TSRA.
BEHIND THE FRONT...THE MIDDLE OF NEXT WEEK SHOULD SEE A RETURN TO
LOW HUMIDITY AND SLIGHTLY BELOW NORMAL TEMPS.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
MOIST SERLY FLOW ASCENDING THE HIGHER TERRAIN OF CENTRAL PA...WITH
A SECONDARY FETCH OF ATLANTIC MOISTURE STREAMING INTO EASTERN PA
AND THE SUSQ VALLEY WILL CONTINUE TO TRIGGER PERIODS OF HEAVY
SHOWERS AND BRIEF/ISOLATED TSRA INTO THIS EVENING.
WHILE CONDITIONS WILL VARY BETWEEN VFR AND IFR ACROSS THE EASTERN
THIRD TO HALF OF THE STATE LATE THIS AFTERNOON AND EVENING...A
SEVERAL TO 8 HOUR PERIOD OF VFR IS EXPECTED IN THE WAKE OF A COLD
FRONT ACROSS THE WESTERN HALF OF THE STATE THROUGH EARLY TONIGHT.
LATE TONIGHT THROUGH ABOUT 12-13Z FRIDAY...DECREASING
WIND...CLEARING SKIES AND LEFTOVER MOISTURE FROM THE RAINFALL WILL
LEAD TO AREAS OF 1/2SM VSBY FOG.
OUTLOOK...
FRI...AREAS OF 1/2SM EARLY AM FOG POSS AT ALL TAF SITES...THEN VFR
ACROSS ALL OF CENTRAL AND SOUTHERN PENN. A FEW PERIODS OF HIGH END
MVFR STRATOCU CIGS POSSIBLE INVOF KBFD FRIDAY.
SAT-MON...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR PAZ057>059-
063>066.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...LAMBERT/STEINBUGL
LONG TERM...EVANEGO
AVIATION...LAMBERT
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
519 PM EDT WED AUG 19 2015
.SYNOPSIS...
A WEAK FRONT WILL APPROACH THE AREA ON THURSDAY...PRECEDED BY
SHOWERS AND THUNDERSTORMS. SOME DRYING IS EXPECTED OVER THE WEEKEND.
ANOTHER WEAK FRONT APPROACHES OUR AREA EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 510PM WED...UPDATED FORECAST TO CONCENTRATE PRECIPITATION TO
EASTERN PARTS OF THE CWA PER RADAR TRENDS AND HRRR GUIDANCE. RADAR
HAS HAD HEAVIEST COVERAGE OF THUNDERSTORMS MOVING EASTWARD WITH SOME
RESIDUAL ACTIVITY ELSEWHERE. HEAVIER STORMS OVER EASTERN PARTS OF
THE CWA AGREES WITH HIGHER CAPE ANALYSIS IN THAT AREA. RAINFALL
AMOUNTS WILL CONTINUE TO BE GENEROUS...GIVEN HIGH PRECIPITABLE
WATER. SHOWERS WILL BEGIN TO TAPER AFTER 3Z THIS EVENING.
AS OF 230 PM WED...RADAR CONTINUES TO SHOW INCREASING COVERAGE AND
EXPECT NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE AREA THROUGH
THE AFTERNOON. SOME MORE STRATIFORM TYPE PRECIP WITH EMBEDDED
THUNDER MAY LINGER INTO THE EVENING HOURS OVER EASTERN AREAS. SPC
MESOANAL SHOWING CAPES IN THE 2000-3000J/KG RANGE OUTSIDE THE
MOUNTAINS. ALSO...THE DCAPE HIGHER TODAY THAN PREVIOUS DAYS NOW
HAVING INCREASED TO OVER 1000J EASTERN AREAS. HENCE...SEVERE STORM
CHANCES HIGHER THIS AFTERNOON AND WE SHOULD SEE SEVERAL PULSE SEVERE
STORMS. THE SEVERE THREAT WILL BE ALONG SIDE THE LOCALIZED HYDRO
THREAT.
IN REGARD TO THE BIG PICTURE...A VORT MAX IS FORECAST TO MOVE ACROSS
THE AREA DURING THE LATE AFTERNOON AND EVENING HOURS WHICH IS THE
PRIMARY TRIGGER OF THE NUMEROUS SHOWERS AND STORMS. NVA BEHIND THIS
FEATURE SHOULD RESULT IN A LULL IN PRECIP COVERAGE DURING THE
OVERNIGHT HOURS. MINIMUM TEMPS ARE EXPECTED TO BE ABOUT A CATEGORY
ABOVE CLIMO.
ON THURSDAY...A DEEP UPPER TROUGH SWINGING THROUGH THE GREAT LAKES
WILL PUSH A COLD FRONT SOUTHEASTWARD AND IT IS FORECAST TO REACH THE
MOUNTAINS DURING THE AFTERNOON. WITH DEEP LAYER MOISTURE STILL IN
PLACE...THERE STILL SHOULD BE DECENT COVERAGE OF SHOWERS AND
THUNDERSTORMS IN THE MOUNTAINS. HOWEVER EAST OF THE MOUNTAINS...WITH
FLOW BECOMING MORE ZONAL/DOWNSLOPE THE COVERAGE SHOULD BE SCT. MODEL
FORECAST SOUNDINGS ALSO INDICATE LESS CAPE...SO SEVERE THREAT
APPEARS ON THE LOW END. MAX TEMPS WILL BE NEAR TO CLIMO.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 200 PM EDT WEDNESDAY...THE SHORT TERM FCST PERIOD INITIALIZES
THURSDAY EVENING AMIDST AN ONGOING COLD FRONTAL INTRUSION.
THE UPPER PATTERN WILL BE HIGHLIGHTED BY A DEEP NEGATIVELY TILTED
LONGWAVE TROF EJECTING THROUGH THE GREAT LAKES WHILE BROAD RIDGING
PREVAILS OVER THE DEEP SOUTH AND EASTERN GULF. AS STATED ABOVE...A
COLD FRONT WILL BE WORKING ITS WAY INTO/THROUGH THE NC HIGH TERRAIN
BY THURSDAY EVENING WITH DEEP SOUTHWESTERLY FLOW PREVAILING OUT
AHEAD. IN RESPONSE...EXPECTING ONGOING CONVECTION IN THE WARM
SECTOR AT FCST INITIALIZATION POSSIBLY AIDED BY ENHANCED SHEARING
AND VORT ADVECTION ALOFT. SHORT TERM GUIDANCE IS NOW IN BETTER
AGREEMENT WITH REGARDS TO THE TRACK/DEPTH OF THE FRONTAL PASSAGE
WITH BOTH THE GFS/NAM ALONG WITH THE ECMWF PUSHING THE BOUNDARY
SOUTH OF THE CWFA...LIKELY WASHING OUT OVER THE LOWCOUNTRY/MIDLANDS
BY MID MORNING FRIDAY.
BROAD SFC HIGH PRESSURE IS FCST TO ADVECT IN FROM THE MIDWEST
INTO THE OHIO VALLEY JUST BEHIND THE FRONT...BEFORE SLIDING OVER
THE SOUTHERN/CENTRAL APPS LATER IN THE DAY. AS A RESULT...DRIER
NORTHERLY FLOW WILL WARRANT DECREASED PRECIPITATION POTENTIAL
AND PARTLY CLOUDY SKIES ACROSS MUCH OF WESTERN NC. DUE TO CLOSER
PROXIMITY TO ANY REMNANT FRONTAL MOISTURE...LOCATIONS ALONG AND
SOUTH OF THE I85 CORRIDOR WILL SEE SLIGHTLY HIGH PROBABILITIES AND
THUS PARTLY/MOSTLY CLOUDY SKIES. NEVERTHELESS...PROFILES ARE NOT
SUPPORTIVE OF ANY DEEP CONVECTION AT THIS TIME THEREFORE NOTHING
MORE THAN GARDEN VARIETY SHOWERS WITH PERHAPS A FEW RUMBLES OF
THUNDER ARE EXPECTED. SATURDAY IS SHAPING UP TO BE THE NICEST DAY
OF THE PERIOD WITH MODELS INDICATING FURTHER DRY AIR INTRUSION
AS THE ABOVE MENTIONED SURFACE RIDGE MOVES EAST OF THE APPS.
MOSGUIDE AND TO SOME EXTENT EVEN THE RAW NAM INDICATES DEWPOINTS
IN THE UPPER 50S ACROSS NORTHWEST NC INCREASING TO THE LOWER 60S
ALONG THE I85 CORRIDOR. THUS EXPECTING MOSTLY SUNNY TO PARTLY
CLOUDY SKIES AND TEMPERATURES A FEW DEGREES BELOW NORMAL ALLOWING
FOR A BEAUTIFUL MID/LATE AUGUST DAY. THAT SAID...NAM GUID DOES
FAVORS AT LEAST SOME CHANCE FOR LOW END DESTABILIZATION OVER THE
SOUTHWEST NC MOUNTAINS AND NORTHEAST GA...THEREFORE WILL INCLUDE
POPS TO ACCOUNT FOR SUCH WITH MAX HEATING ON SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AT 230 PM EDT WEDNESDAY...ON SUNDAY AN UPPER RIDGE WILL BE OVER THE
WESTERN USA...WITH A MEAN TROUGH OVER THE EAST. THE PATTERN
AMPLIFIES SLIGHTLY INTO TUESDAY AS A CLOSED UPPER LOW CROSSES SOUTH
CENTRAL CANADA. THE PATTERN DEAMPLIFIES SLIGHTLY BY THURSDAY AS THE
CANADIAN LOW APPROACHES THE ATLANTIC....BY WHICH TIME SOME
PROGRESSION TAKES PLACE...AND THE UPPER TROUGH REACHES THE EASTERN
SEABOARD...WHILE THE RIDGE UPSTREAM CROSSES THE PLAINS AND EXTENDS
INTO THE GULF STATES.
AT THE SURFACE...SUNDAY STARTS OUT WITH HIGH PRESSURE ALONG THE
EASTERN SEABOARD...WITH A COLD FRONT UPSTREAM FORM THE GREAT LAKES
TO THE SOUTHERN PLAINS. THIS FRONT REACHES THE SOUTHERN APPALACHIANS
ON MONDAY...MOVING TO THE COASTAL PLAIN BY TUESDAY...WHERE IT STALLS
AND REMAINS INTO WEDNESDAY. OUR AREA CAN EXPECT AN ACTIVE PATTERN
AHEAD OF AND ALONG THE FRONT...WITH A DRYING TREND IN THE
WAKE OF THE FRONT. AT THIS TIME...PRECIPITATION AMOUNTS ARE NOT
EXPECTED TO BE EXCESSIVE AS THE FRONT DOES NOT STALL UNTIL EAST OF
OUR AREA. TEMPERATURES WILL RUN NEAR NORMAL.
&&
.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
AT KCLT...LOOKS LIKE IT IS GOING TO BE ACTIVE DAY FOR CONVECTION AS
RADAR BEGINNING TO SHOW QUITE A BIT OF COVERAGE. CURRENT TRENDS
INDICATE THAT TEMPO TSRA WILL OCCUR FROM 19Z-23Z WITH PERHAPS SOME
MORE STRATIFORM TYPE PRECIP EXTENDING INTO THE EVENING HOURS AS A
VORT MAX MOVES THROUGH. IFR RESTRICTIONS CERTAINLY POSSIBLE IN THE
HEAVIER CONVECTIVE CELLS. AFTER ABOUT 03Z PRECIP SHOULD END WITH
CONDITIONS VFR. GUIDANCE NOT TOO EXCITED ABOUT EARLY MORNING
FOG/STRATUS BUT NOT CONVICNED IT WILL NOT OCCUR...SO MENTIONED SOME
LIGHT FOG WITH SCT010 CIRCA 12Z.
ELSEWHERE...FAIRLY SIMILAR CONDITIONS TO KCLT WITH TEMPO TSRA AND
POSSIBLE IFR RESTRICTIONS INTO THE EARLY EVENING HOURS. PRECIP
SHOULD END BY 03Z. EXPECT ONLY PATCHY IFR STRATUS/FOG EARLY
THURSDAY. CONFIDENCE NOT HIGH ENOUGH TO PUT INTO TAF EXCEPT AT KAVL.
OUTLOOK...A COLD FRONT WILL PUSH THROUGH THE AREA LATE THURSDAY AND
THURSDAY NIGHT. ASSOCIATED SHOWERS/THUNDERSTORSM ARE EXPECTED TO END
THURSDAY NIGHT. LINGERING LOW LEVEL MOISTURE MAY RESULT IN
RESTRICTIONS IN FOG/STRATUS EARLY FRIDAY. DRY HIGH PRESSRUE BUILDING
IN FROM THE NORTH WILL LIMIT RESTRICTIONS THROUGH THE WEEKEND.
CONFIDENCE TABLE...
21-03Z 03-09Z 09-15Z 15-18Z
KCLT HIGH 100% HIGH 85% HIGH 100% HIGH 100%
KGSP HIGH 91% HIGH 83% HIGH 100% HIGH 88%
KAVL HIGH 100% HIGH 96% HIGH 96% HIGH 97%
KHKY HIGH 100% HIGH 87% HIGH 86% HIGH 100%
KGMU MED 75% HIGH 87% HIGH 100% HIGH 87%
KAND HIGH 100% HIGH 100% HIGH 91% HIGH 81%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JAT
NEAR TERM...LG/WJM
SHORT TERM...CDG
LONG TERM...JAT
AVIATION...LG
AREA FORECAST DISCUSSION
NWS AMARILLO TX
1050 PM CDT THU AUG 20 2015
.AVIATION...
06Z TAF CYCLE
PERUSING THE LATEST HRRR AND RAP13 MODELS...CONVECTION EXPECTED TO
DEVELOP AFTER 08Z TO 10Z FRIDAY ACROSS THE OKLAHOMA PANHANDLE AND THE
NORTHERN AND CENTRAL TEXAS PANHANDLE. THE CONVECTION EXPE4CTED TO
MOVE EAST AND SOUTH ACROSS MUCH OF THE EASTERN PORTION OF THE
PANHANDLES BY 13Z TO 15Z FRIDAY. THE GUYMON TAF SITE MOST LIKELY
AFFECTED BY THIS CONVECTION LATE TONIGHT AND COULD POSSIBLY IMPACT
THE AMARILLO TAF SITE AS WELL CLOSER TO 10Z TO 12Z FRIDAY. HOWEVER
CONFIDENCE IS LOW ON THE AMARILLO TAF SITE AND WILL INSERT A VCTS
REMARK FOR NOW LATER TONIGHT AND EARLY FRIDAY MORNING. VFR CONDITIONS
SHOULD BECOME MVFR IN CEILINGS AFTER 10Z TO 12Z FRIDAY...AND THEN MAY
BECOME VFR AGAIN BETWEEN 18Z FRIDAY AND 00Z SATURDAY. SOUTHEAST TO
SOUTH WINDS 10 TO 20 KNOTS WILL INCREASE AND BECOME GUSTY AROUND 15
TO 20 KNOTS AFTER 14Z TO 16Z FRIDAY AND PRIOR TO 00Z SATURDAY.
SCHNEIDER
&&
.PREV DISCUSSION... /ISSUED 641 PM CDT THU AUG 20 2015/
AVIATION...
00Z TAF CYCLE
AN UPPER TROUGH WILL PUSH SOUTHEAST ACROSS THE PANHANDLES LATER
TONIGHT AND FRIDAY MORNING ON A NORTHWESTERLY FLOW ALOFT. CANNOT RULE
OUT CONVECTION LATE TONIGHT...AFTER 07Z TO 09Z FRIDAY...MAINLY AT THE
DALHART TAF SITE AND POSSIBLE EVEN THE GUYMON TAF SITE. DECIDED TO
HOLD OFF FOR NOW MENTIONING IN THE 00Z TAF FORECAST PACKAGE DUE TO
LOW CONFIDENCE AT THE MOMENT BUT PROBABLY WILL NEED TO BE ADDED
LATER. AN CONVECTION LATE TONIGHT COULD REACH THE AMARILLO TAF SITE
BY 12Z FRIDAY...BUT AGAIN...CONFIDENCE TOO LOW TO MENTION. VFR
CONDITIONS WILL PREVAIL EARLY HOWEVER MVFR CEILINGS EXPECTED AT ALL
THREE TAF SITES AFTER 10Z TO 12Z FRIDAY. VFR CONDITIONS MAY RETURN TO
THE DALHART TAF SITE AFTER 14Z TO 16Z FRIDAY. SOUTHERLY WINDS 5 TO 15
KNOTS WILL BACK TO THE SOUTHEAST AFTER 00Z FRIDAY AND INCREASE TO
AROUND 10 TO 20 KNOTS WITH SOME HIGHER GUSTS LIKELY AFTER 14Z TO 16Z
FRIDAY.
SCHNEIDER
PREV DISCUSSION... /ISSUED 453 PM CDT THU AUG 20 2015/
DISCUSSION...
EARLY THIS AFTERNOON REGIONAL SURFACE ANALYSIS SHOWED THE COLD FRONT
ACROSS DEEP SOUTH TEXAS WITH CONVECTION CONFINED TO SOUTHERN PORTIONS
OF THE STATE. VISIBLE SATELLITE AND SURFACE OBSERVATIONS SHOWED
EXTENSIVE LOW STRATUS PERSISTING ACROSS EASTERN TEXAS BUT STRATUS HAS
MOSTLY DIMINISHED FURTHER WEST. SOME CUMULUS HAS DEVELOPED ACROSS
PORTIONS OF THE PANHANDLE AND BENEATH INCREASING CIRRUS WITHIN
STRENGTHENING WEST-NORTHWESTERLY FLOW ALOFT. A STRENGTHENING LEE
SURFACE TROUGH HAS RESULTED IN A RETURN OF SOUTHERLY SURFACE WINDS
BUT LOW LEVELS REMAIN RELATIVELY DRY. EVEN WITH AT LEAST PARTIAL
INSOLATION TEMPERATURES HAVE BEEN ABOUT 10 DEGREES BELOW NORMAL FOR
THIS TIME OF YEAR.
SHORT TERM GUIDANCE IS INSISTENT ON A NORTHWARD SURGE OF LOW LEVEL
THETA-E LATER TONIGHT AS LOW LEVEL JET STRENGTHENS. WEAK PRESSURE
ADVECTION ON MOISTENING 310K SURFACE RAISES CONCERN FOR ELEVATED
CONVECTIVE DEVELOPMENT LATE TONIGHT AND HAVE RETAINED A BROAD AREA
OF SLIGHT PRECIPITATION CHANCES AS CONFIDENCE ON SPATIAL DETAILS FOR
WHERE CONVECTION WILL FORM IS LOW. COVERAGE MAY INCREASE BY AROUND
DAYBREAK ACROSS THE EASTERN PORTION OF THE PANHANDLES. AT LEAST WEAK
ELEVATED INSTABILITY MAY BE SUFFICIENT FOR SUB-SEVERE HAIL WITH THE
MOST INTENSE STORMS BUT SEVERE THUNDERSTORMS ARE UNLIKELY.
A CONTINUATION OF SOUTHERLY FLOW AND LOW LEVEL MOISTENING IS
EXPECTED TOMORROW. SOME LOW CLOUDS AND SHOWERS/STORMS MAY LINGER
MAINLY ACROSS THE EAST IN WARM/MOIST ADVECTION REGIME BUT AS 850 MB
THERMAL GRADIENT BECOMES MORE PARALLEL TO LOW LEVEL FLOW THROUGHOUT
THE DAY AND SO CONVECTION SHOULD WANE AND CLOUDS SHOULD BREAK. WEAK
MID LEVEL PERTURBATIONS SEEN IN WATER VAPOR LOOP OVER THE CENTRAL
ROCKIES WILL PROVIDE SUBTLE LIFT OF AN INCREASINGLY UNSTABLE
ENVIRONMENT LATE IN THE AFTERNOON. DIABATIC HEATING OF MOISTENING
BOUNDARY LAYER...MODERATE INSTABILITY WILL DEVELOP. ISOLATED TO
SCATTERED THUNDERSTORMS SHOULD FORM NEAR THE SURFACE TROUGH ACROSS
THE WESTERN PORTION OF THE PANHANDLES AND FURTHER WEST ACROSS THE
HIGHER TERRAIN OF EASTERN NEW MEXICO. MODELS ARE NOT PARTICULARLY
COHERENT WITH WITH HANDLING THESE SMALL SCALE FEATURES AND ALSO THE
EVOLUTION OF THE LEE SURFACE TROUGH SO SPATIAL AND TEMPORAL DETAILS
OF CONVECTION IS SOMEWHAT UNCERTAIN. THE PRESENCE OF MODERATE
INSTABILITY AND AT LEAST MODEST STORM DEPTH SHEAR MAY SUPPORT STORM
ORGANIZATION AND SUSTENANCE SUPPORTING LARGE HAIL AND DAMAGING WIND
POTENTIAL INTO THE EVENING. SOME INCREASE IN COVERAGE SEEMS LIKELY
BY EVENING PARTICULARLY ACROSS THE EASTERN PORTION OF THE PANHANDLES
AS LOW LEVEL JET STRENGTHENS.
FORECAST UNCERTAINTY GROWS ON SATURDAY AND BEYOND. A POTENT
SHORTWAVE TROUGH WILL MOVE ACROSS THE ROCKIES AND INTO THE NORTHERN
PLAINS SENDING A COLD FRONT SOUTHWARD. THE PRECEDING ENVIRONMENT IS
NOT EXPECTED TO CHANGE MUCH AS IT WILL REMAIN MOIST WITH DIURNAL
HEATING RESULTING IN MODERATE INSTABILITY. ABSENCE OF ANY RESOLVABLE
DISTURBANCES IN THE FLOW AND SUBTLE LARGE SCALE MID LEVEL HEIGHT
RISES JUSTIFIES A DRY FORECAST FOR SATURDAY AT THIS TIME. CHANCES
INCREASE DURING THE EVENING AS LEE SURFACE LOW SHIFTS EAST AND COLD
FRONT MOVES INTO THE AREA...BUT CONFIDENCE IS RELATIVELY LOW WITH
HOW THIS SCENARIO WILL PLAY OUT. DEEP LAYER SHEAR WILL SUPPORT
ORGANIZED STORMS AND SEVERE POTENTIAL. MADE MINOR ADJUSTMENTS TO THE
TIMING OF THE FRONT BRIGING IT INTO THE NORTHERN PORTION OF THE AREA
QUICKER THAN MOST GUIDANCE AND INCREASING WIND SPEEDS BEHIND IT.
POST FRONTAL AIR MASS SHOULD BE RELATIVELY STABLE ON SUNDAY LIMITING
POTENTIAL FOR CONVECTION. HAVE CONFINED LOW PROBABILITIES TO ROUGHLY
THE SOUTHERN HALF OF THE AREA BOTH SUNDAY AND MONDAY. DRIER AND
WARMER WEATHER IS EXPECTED MUCH OF NEXT WEEK AS THE LARGE SCALE
PATTERN AMPLIFIES AND MEAN RIDGING BUILDS.
BRB
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
11/10
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
348 PM CDT WED AUG 19 2015
.SYNOPSIS...
THE MAIN STORY WITH THIS FORECAST PACKAGE WILL BE THE COOLER
WEATHER AND RAIN CHANCES OVER THE NEXT 12-24 HOURS. A RETURN TO
WARM CONDITIONS IS EXPECTED LATER THIS WEEK AND THROUGH THE
WEEKEND WITH LOWER CHANCES FOR PRECIPITATION.
&&
.SHORT TERM (TONIGHT THROUGH FRIDAY)...
A VERY DIFFICULT FORECAST EXISTS WITH SOME DIFFERENCES BETWEEN
BOTH HI-RES AND COARSE MODEL SOLUTIONS. AS IS OFTEN THE
CASE...NUMERICAL WEATHER PREDICTION OFTEN STRUGGLES WITH EVENTS
THAT ARE EITHER WEAKLY FORCED OR PRIMARILY DRIVEN BY MESOSCALE
PHENOMENON. IN THE CASE OF TODAY...A BULK OF THE LARGE SCALE
FORCING FOR ASCENT WAS DISPLACED WELL TO THE NORTH OF
NORTH/CENTRAL TEXAS AND THE MAIN FOCUSING MECHANISMS FOR WHAT RAIN
DID FALL THIS MORNING AND THIS AFTERNOON WERE OUTFLOW BOUNDARIES
FROM PREVIOUS CONVECTION ACROSS OK AND THE TX PANHANDLE.
MOST OF THE CONVECTION THIS AFTERNOON ON AREA RADARS APPEAR TO BE
ALONG THE FRONT WHERE SUFFICIENT LOW LEVEL CONVERGENCE IS
OCCURRING. WITH THE FRONT STARTING TO QUICKLY MOVE SOUTHWARD MOST
OF THIS ACTIVITY IS SHORT LIVED AS IT IS BEING UNDERCUT BY THE
SHALLOWER/COOLER AIR.
FOR THE REST OF THE AFTERNOON AND TONIGHT...STILL FEEL CONFIDENT
ENOUGH THAT THERE WILL BE A COUPLE OF AREAS THAT COULD SEE SOME
MEASURABLE PRECIPITATION. THE FIRST WILL BE ALONG OUR SOUTHEAST
ZONES NEAR THE SFC-925 MB FRONT LATER THIS AFTERNOON AND INTO
TONIGHT. MOST COARSE MODELS /EXCLUDING THE NAM/ SUGGEST THAT SOME
LOW LEVEL FRONTOGENESIS WILL OCCUR AND SHOULD YIELD ISOLATED TO
SCATTERED CONVECTION. THE OVERALL SEVERE POTENTIAL SEEMS
RELATIVELY LOW...BUT GIVEN THE UNSTABLE AIRMASS AHEAD OF THE
FRONT...WOULD NOT RULE OUT A STRONG DOWNBURST OR TWO. THERE MAY BE
A SMALL HAIL RISK WITH CONVECTION NEAR THE FRONT...BUT THINK THAT
CONVECTION IS BECOMING UNDERCUT TOO QUICKLY BEFORE HAIL PRODUCTION
CAN OCCUR.
THE SECOND AREA WITH A SLIGHTLY HIGHER CHANCE FOR PRECIPITATION
WILL BE ALONG AND NORTH OF THE INTERSTATE 20 CORRIDOR WHERE 850 MB
FRONTOGENETIC FORCING IS BEING ADVERTISED. PER THE TTU WRF AND
LATEST HRRR SOME AREAS OF ISOLATED TO WIDELY SCATTERED ACTIVITY IS
EXPECTED TO DEVELOP DURING THE OVERNIGHT HOURS INTO EARLY THURSDAY
MORNING. CLOSER TO SUNRISE...THIS ACTIVITY SHOULD SHIFT SOUTHWARD
AS DRIER AIR WORKS ITS WAY IN FROM THE NORTH. CURRENTLY THINK THAT
SOME SKIES ACROSS OUR IMMEDIATE RED RIVER ZONES MAY CLEAR ENOUGH
TO ALLOW FOR SOME DECENT COOLING. WITH THE CONTINUED NORTH
WINDS...THIS SHOULD ALLOW TEMPERATURES TO FALL INTO THE 60S WITH
PERHAPS EVEN A FEW UPPER 50S ALONG THE RED RIVER.
FOR THURSDAY AND THURSDAY NIGHT...THE HIGHEST RAIN CHANCES WILL
REMAIN DOWN ALONG OUR SOUTHEASTERN ZONES WHERE THE FRONT WILL
STALL AND BEGIN TO LOSE ITS BAROCLINICITY. MAX TEMPERATURES WILL
DEPEND ON THE AMOUNT OF SUNSHINE THAT CAN FILTER IN TO HELP OFFSET
SOME OF THE COLD AIR ADVECTION. IN GENERAL THINK THAT HIGHS WILL
CLIMB INTO THE LOW TO MID 80S...EXCEPT ACROSS FAR SOUTHEASTERN
ZONES WHERE UPPER 80S MAY BE POSSIBLE...ESPECIALLY IF THE FRONT
STALLS FURTHER NORTH THAN CURRENT EXPECTATIONS. WITH THE ZONAL
FLOW ALOFT ACROSS THE CENTRAL PLAINS...LOW LEVEL FLOW SHOULD TURN
AROUND TO THE EAST AND EVENTUALLY SOUTHEAST LATE THURSDAY NIGHT
INTO FRIDAY. HELD ON TO SOME LINGERING SLIGHT CHANCE POPS ACROSS
EASTERN ZONES WITH THE MOIST EAST FLOW AS ADVERTISED BY THE ECMWF
AND GFS. INSTABILITY APPEARS MEAGER...BUT WENT AHEAD AND MENTIONED
AN ISOLATED THUNDERSTORM OR TWO IN THE WORDED FORECASTS.
FOR FRIDAY...ANOTHER UPPER WAVE LOOKS TO MOVE EASTWARD OUT FROM
THE INTERMOUNTAIN WEST. THERE IS SOME WEAK LARGE SCALE ASCENT AS
EVIDENCED BY SOME UPPER LEVEL PV ACROSS THE NORTHERN AND
NORTHEASTERN ZONES. AS A RESULT...RETAINED INHERITED SLIGHT CHANCE
POPS ON FRIDAY. WITH THE RETURN TO THE SOUTH FLOW...EXPECT AN
INCREASE IN LOW LEVEL MOISTURE AND AN INCREASE IN THE
TEMPERATURES AS WELL. TEMPERATURES WILL CLIMB BACK TOWARDS
SEASONAL NORMS ON FRIDAY...OUTSIDE ANY PRECIPITATION THAT OCCURS.
&&
.LONG TERM (SATURDAY AND SUNDAY)...
FOR SATURDAY AND SUNDAY...MAINTAINED SLIGHT CHANCES FOR
PRECIPITATION ACROSS NORTHERN AND EASTERN ZONES WITH THESE AREAS
REMAINING ON THE NORTHERN AND EASTERN FRINGES OF A BUILDING MID
LEVEL RIDGE. HIGH TEMPERATURES SHOULD CLIMB INTO THE 90S AREA
WIDE ON SATURDAY. BOTH THE GFS AND ECMWF ADVERTISE A WEAK
BACKDOOR COLD FRONT SOMETIME LATE SUNDAY. THE RIDGE SHOULD
GRADUALLY WEAKEN ON ITS EASTERN PERIPHERY WHICH MAY ALLOW FOR THE
DEVELOPMENT OF SOME PRECIPITATION ALONG THE FRONT. AS A
RESULT...HAVE INTRODUCED LOW CHANCE POPS MAINLY ALONG THE RED
RIVER AND ACROSS EASTERN ZONES FOR SUNDAY AND INTO THE DAY ON
MONDAY. THERE ARE SOME DISCREPANCIES BETWEEN THE GFS AND THE ECMWF
IN THE LONG TERM WITH REGARDS TO HOW FAR SOUTH THIS NEXT COLD
FRONT WILL SWEEP SO CONFIDENCE IS NOT HIGH ENOUGH TO DEVIATE TOO
FAR FROM A CONSENSUS/BLENDED FORECAST.
BAIN
&&
.AVIATION...
/ISSUED 100 PM CDT WED AUG 19 2015/
/18Z TAFS/
COLD FRONT IS MOVING THROUGH THE DFW AREA NOW AND NORTH WINDS ARE
EXPECTED AT ALL THE DFW METROPLEX TAF SITES BY 19Z. SUSTAINED
WIND SPEEDS OF 12-16KTS WITH WIND GUSTS IN THE 15-25KT RANGE WILL
OCCUR BEHIND THE FRONT THROUGH THE AFTERNOON HOURS. THERE IS A
SMALL CHANCE FOR ISOLATED SHOWERS OR STORMS AS THE FRONT MOVES
THROUGH AND WILL CARRY A VCSH FOR TWO HOURS AFTER THE FRONT
PASSES. THEN A FEW DRY HOURS ARE EXPECTED WITH ANOTHER CHANCE FOR
SHOWERS OVERNIGHT. VFR CONDITIONS ARE EXPECTED TO PREVAIL BUT IT
IS POSSIBLE MVFR CIGS MAY DEVELOP OVERNIGHT OVER THE SHALLOW
SURFACE COLD FRONT.
THE FRONT IS EXPECTED TO REACH KACT AROUND 22-23Z BUT A WIND
SHIFT TO THE NORTH MAY OCCUR BEFORE THE TRUE FRONT ARRIVES. WILL
CARRY VCTS THROUGH THE AFTERNOON HOURS FOR CONVECTION DEVELOPING
AHEAD OF THE FRONT...AND THEN CONTINUE VCTS FOR ABOUT 2 HOURS
AFTER THE FRONT PASSES. ADDITIONAL SHOWERS ARE EXPECTED OVERNIGHT
ALONG WITH THE DEVELOPMENT OF MVFR CIGS.
JLDUNN
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 67 84 73 93 77 / 40 20 10 20 10
WACO, TX 69 83 74 94 76 / 30 30 20 10 5
PARIS, TX 63 79 64 89 73 / 40 20 20 30 30
DENTON, TX 63 82 69 93 76 / 40 10 10 20 20
MCKINNEY, TX 64 81 69 92 76 / 40 20 10 30 20
DALLAS, TX 68 85 74 94 78 / 40 20 10 20 10
TERRELL, TX 66 81 72 92 76 / 40 30 20 20 10
CORSICANA, TX 68 82 73 93 76 / 30 30 20 20 10
TEMPLE, TX 70 86 73 94 75 / 40 30 20 10 5
MINERAL WELLS, TX 64 83 70 94 75 / 40 20 10 20 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
82/15
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
944 PM CDT THU AUG 20 2015
.UPDATE...MID LEVEL CLOUD DECK FORMING OVER ERN NE AND WRN IA
WILL TREK ACROSS SRN WI FRI AM AND POSSIBLY LINGER INTO THE
AFTERNOON OVER ERN WI. CLOUDS ARE ASSOCIATED WITH 850-700 MB WARM
ADVECTION AND FRONTOGENESIS. PARTLY CLOUDY SKIES EXPECTED FOR THE
AFTERNOON WITH SOME FAIR WX CUMULUS. HIGH TEMPS NEAR 80F...BECOMING
COOLER NEAR THE LAKE VIA A LAKE BREEZE.
&&
.AVIATION/06Z TAFS/...MAINLY VFR CONDITIONS FOR EARLY FRI AM
THROUGH FRI NT. A RIDGE OF HIGH PRESSURE WILL MOVE ACROSS SRN WI
EARLY FRI AM WITH SOME FOG IN LOW LYING AREAS BUT TAF SITES
SHOULD REMAIN VFR. A MID LEVEL DECK OF BROKEN CLOUD COVER IS
EXPECTED FRI AM AND POSSIBLY LINGER INTO THE AFTERNOON OVER ERN
WI BEFORE GIVING WAY TO FAIR WX CUMULUS AROUND 5-6 KFT.
&&
.PREV DISCUSSION... /ISSUED 248 PM CDT THU AUG 20 2015/
TONIGHT AND FRIDAY... FORECAST CONFIDENCE...HIGH
CLOUDS WILL SLOWLY CLEAR OUT DURING THE EVENING AND OVERNIGHT HOURS
AS A 500 MB SHORTWAVE TROUGH EVENTUALLY MAKES ITS WAY OFF TO THE
NORTH AND EAST. NAM AND RAP BUFKIT SOUNDINGS INDICATE A FAIRLY DRY
PROFILE BY 06Z TONIGHT. OVERNIGHT CLEARING...ALONG WITH CALMER
WINDS...WILL LEAD TO SOME DECENT ADIABATIC COOLING. LOWS TONIGHT
LOOK TO REACH PRIMARILY INTO THE LOWER TO MID 50S ACROSS SOUTHERN
WISCONSIN...WITH SOME ISOLATED LOCATIONS REACHING INTO THE UPPER
40S.
ONCE THE SHORTWAVE MOVES OFF TO THE EAST...A MORE ZONAL MID-LEVEL
FLOW WILL MOVE INTO THE REGION...KEEPING CONDITIONS QUIET. A PUSH OF
FEW TO SCATTERED LOW-LEVEL CLOUDS COULD APPEAR BY SUNRISE FRIDAY AS
A SURGE OF LOW-LEVEL MOISTURE MAKES ITS WAY INTO THE REGION.
ADDITIONALLY...SOME PATCHY FOG IS POSSIBLE ALONG THE WISCONSIN RIVER
VALLEY DURING THE EARLY MORNING HOURS FRIDAY. EXPECT QUIET
CONDITIONS DURING THE DAY FRIDAY AS NEGATIVE VORTICITY ADVECTION AND
SFC HIGH PRESSURE WILL BE IN CONTROL OVER THE REGION. SSW WINDS WILL
BECOME GUSTY AGAIN DURING THE DAY FRIDAY...ALTHOUGH NOT AS STRONG AS
WINDS FROM THURSDAY.
FRIDAY NIGHT AND SATURDAY...FORECAST CONFIDENCE IS HIGH.
HIGH PRESSURE WILL REMAIN ANCHORED OVER THE EASTERN GREAT
LAKES...KEEPING US DRY THROUGH SATURDAY. WE SHOULD SEE SOME
RADIATIVE COOLING FRIDAY NIGHT...BUT IT WILL BE TEMPERED BY SOME
DECENT WINDS AND MIXING JUST ABOVE THE BOUNDARY LAYER. A TROUGH OF
LOW PRESSURE AND IS ASSOCIATED COLD FRONT WILL APPROACH THE REGION
ON SATURDAY...TIGHTENING UP THE PRESSURE GRADIENT ACROSS THE
FORECAST AREA. LOOK FOR SOUTHERLY WINDS TO INCREASE AND BECOME
QUITE GUSTY IN THE AFTERNOON. TEMPS SHOULD CLIMB INTO THE LOWER
AND MID 80S.
SATURDAY NIGHT AND SUNDAY...FORECAST CONFIDENCE IS MEDIUM.
THE TROUGH/CDFNT TO THE WEST WILL PUSH INTO SOUTHERN WISCONSIN
AFTER MIDNIGHT SATURDAY NIGHT. THE MODELS SHOW BETTER SUPPORT
THROUGH A DEEP LAYER UPSTREAM...BUT IT WEAKENS AS THE SFC TROUGH
MOVES IN. GIVEN THE LATE TIMING OF THE TROUGH ARRIVAL AND THE
WEAKENING SUPPORT...I/LL BE SOMEWHAT CONSERVATIVE IN PRECIP
CHANCES AS IT TRACKS EAST THROUGH SUNDAY MORNING. THE BEST CHANCE
FOR RAIN WILL BE WEST AND NORTH OF MADISON LATE SATURDAY NIGHT
INTO SUNDAY MORNING. WEAKER CHANCES ALONG THE WI/IL BORDER AND THE
SOUTHEAST.
THE TROUGH AND CDFNT WILL EXIT EASTERN WISCONSIN DURING THE EARLY
AFTERNOON WITH COOLER AND DRIER AIR MOVING RIGHT BACK IN.
MONDAY THROUGH THURSDAY...FORECAST CONFIDENCE IS HIGH.
BIG CANADIAN HIGH PRESSURE BUILDS IN FOR MUCH OF NEXT WEEK. EXPECT
DRY CONDITIONS WITH HIGHS IN THE 70S AND LOWS IN THE 50S. WE MIGHT
SEE ANOTHER TROUGH APPROACH LATE IN THE WEEK FOR A CHANCE OF RAIN.
LOTS OF MODEL UNCERTAINTY WITH THAT.
AVIATION/00Z TAFS/...
EXPECT VFR CIGS AND VSBYS TONIGHT AS AN AREA OF LOW PRESSURE SLOWLY
MAKES ITS WAY OFF TO THE NORTH AND EAST. THE LAST OF THE LOW- TO MID-
LEVEL CLOUDS WILL SLOWLY MOVE OUT BY THE EARLY EVENING. WINDS WILL
WEAKEN THIS EVENING AS SFC PRESSURE GRADIENT WEAKENS AND THE
BOUNDARY LAYER DECOUPLES. WINDS WILL BECOME MORE NORTHWESTERLY THIS
EVENING AS THE AREA OF LOW PRESSURE MOVES OFF TO THE EAST. THERE
COULD BE SOME PATCHY FOG DEVELOPING JUST WEST OF THE MSN TAF SITE IN
THE WISCONSIN RIVER VALLEY...BUT NOT FORECAST TO AFFECT THE MSN AREA
DIRECTLY. GUSTY WINDS WILL RETURN FROM THE SOUTH-SOUTHWEST DURING
THE DAY FRIDAY.
MARINE...
SMALL CRAFT ADVISORY FOR ALL NEARSHORE ZONES WILL CONTINUE UNTIL 00Z
TONIGHT AS WINDS WILL WEAKEN BY THAT TIME DUE TO WEAKENING SFC
PRESSURE GRADIENT. WINDS WILL EVENTUALLY VEER FROM THE WEST THIS
EVENING TO A MORE NORTHWESTERLY DIRECTION. NEARSHORE WINDS WILL
ABATE TONIGHT...BUT EXPECT GUSTY SSW WINDS TO RETURN DURING THE
DAY FRIDAY...ALTHOUGH NOT EXPECTED TO REACH SMALL CRAFT ADVISORY
CRITERIA.
BEACHES...
BREEZY WESTERLY WINDS WILL PERSIST UNTIL EARLY EVENING. WIND SPEEDS
WILL MOSTLY BE BETWEEN 15 TO 25 MPH. SWIM RISK WILL BE LOW DUE TO
MORE OF AN OFFSHORE WIND EXPECTED. GUSTY SOUTH-SOUTHWEST WINDS ARE
EXPECTED TO RETURN DURING THE DAY FRIDAY.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...GEHRING
TONIGHT/FRIDAY AND AVIATION/MARINE...JTS
FRIDAY NIGHT THROUGH THURSDAY...DAVIS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1237 PM CDT WED AUG 19 2015
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND THURSDAY
ISSUED AT 305 AM CDT WED AUG 19 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR ANALYSIS SHOW OCCLUDED
LOW PRESSURE SPINNING OVER SOUTHERN MINNESOTA AND A COLD FRONT
ARCING SOUTHWARD OVER EASTERN IOWA AND CENTRAL MISSOURI. A PRE-
FRONTAL TROUGH IN COMBINATION WITH A SHORTWAVE IS PUSHING A BROKEN
BAND OF SHOWERS NORTHEAST OVER NORTH-CENTRAL AND FAR NORTHEAST WI
EARLY THIS MORNING. THESE SHOWERS SHOULD DEPART BY 12Z. ADDITIONAL
LIGHT SHOWERS ARE OCCURRING ALONG THE COLD FRONT...WHICH WILL BE
REACHING CENTRAL WI BY 12Z. AS LOW PRESSURE AND COLD FRONT MOVE
NORTHEAST...PRECIP TRENDS ARE THE MAIN FORECAST CONCERNS.
TODAY...OCCLUDED LOW PRESSURE WILL LIFT INTO NORTHWEST WISCONSIN
EARLY THIS AFTERNOON AND INTO CENTRAL LAKE SUPERIOR BY EARLY THIS
EVENING. MEANWHILE THE COLD FRONT WILL MOVE ACROSS MOST OF THE
FORECAST AREA THIS MORNING EXCEPT FOR THE DOOR PENINSULA...WHICH
SHOULD OCCUR EARLY THIS AFTERNOON. SCATTERED SHOWERS WILL ACCOMPANY
THE COLD FRONT. BUT WITH DAYTIME HEATING...PROGGED SOUNDINGS
INDICATE THAT 500-800 J/KG OF CAPE COULD DEVELOP OVER NE WI AHEAD OF
THE FRONT. AS A RESULT...NOT OUT OF THE QUESTION THAT A FEW
THUNDERSTORMS COULD POP UP BY LATE IN THE MORNING ALONG THE
BOUNDARY. ANY THUNDERSTORMS WILL BE CAPABLE OF TRANSFERRING HIGHER
WINDS ALOFT TO THE SURFACE SO WILL KEEP A MENTION OF GUSTY WINDS
WITH ANY THUNDERSTORMS IN THE HWO. BEHIND THE FRONT...SOUTHWEST
WINDS WILL BECOME BREEZY IN THE AFTERNOON WITH SOME GUSTS TO 35 MPH
POSSIBLE. WRAP AROUND SHOWERS COULD ALSO MOVE INTO CENTRAL AND
NORTH-CENTRAL WI BY MID TO LATE AFTERNOON. HIGHS RANGING FROM THE
MID 60S WEST TO MID 70S EAST.
TONIGHT...THE UPPER TROUGH MOVES OVERHEAD AS THE SHORTWAVE IN THE
BASE OF THE TROUGH LIFTS NORTHWARD OVER EASTERN WISCONSIN. DEEPER
MOISTURE WILL ACCOMPANY THE TROUGH...WITH MOISTURE EXTENDING UPWARDS
OF 700MB OVERNIGHT. ANY BREAKS IN THE CLOUDS OVER EASTERN WISCONSIN
AT THE START OF THE NIGHT WILL THEREFORE LIKELY FILL IN AS THE
EVENING PROGRESSES AND WILL SPREAD A SLIGHT CHANCE OF RAIN ALL THE
WAY TO THE LAKESHORE. THE MORE PERSISTENT RAINS SHOULD FALL OVER
NORTH-CENTRAL WI WHERE A SURFACE TROUGH WILL MOVE THROUGH. LOWS
MAINLY IN THE 50S.
THURSDAY...THE UPPER TROUGH WILL CONTINUE TO BE OVERHEAD DURING THE
MORNING....WHICH SHOULD LEAD TO SCATTERED SHOWERS AND SPOTTY
DRIZZLE. THEN THE LIGHT PRECIP SHOULD COME TO AN END IN THE
AFTERNOON AS THE TROUGH LIFTS TO THE NORTHEAST. HIGHS RANGING FROM
THE LOW 60S NORTH TO LOW 70S SOUTH.
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY
ISSUED AT 305 AM CDT WED AUG 19 2015
THE TWO MAIN WEATHER FEATURES TO KEY ON DURING THE EXTENDED
PERIOD WL BE THE MOVEMENT OF THE NEXT PROMINENT SHORTWAVE
TROF/ASSOCIATED CDFNT ACROSS THE NRN TIER OF STATES THIS WEEKEND
INTO EARLY NEXT WEEK AND THE BUILDING OF AN UPR RDG OVER THE HI
PLAINS. THE MAIN STICKING POINT AMONG THE MODELS IS WHETHER THIS
SHORTWAVE TROF WL BE PROGRESSIVE OR CLOSE OFF INTO AN UPR LOW
SOMEWHERE NEAR THE GREAT LAKES. THE ANSWER TO THIS QUESTION WOULD
GO A LONG WAY IN DETERMINING THE WEATHER IN OUR AREA FROM SUNDAY
THRU TUE. AFTER A BRIEF WARM-UP THRU SAT...TEMPS ARE EXPECTED TO
FALL BELOW NORMAL FOR THE FIRST HALF OF NEXT WEEK.
THE GREAT LAKES REGION TO RESIDE ON THE NRN FRINGES OF AN AREA OF
HI PRES MOVING ALONG THE OHIO RIVER VALLEY THU NGT. CLEARING
SKIES...LIGHT WINDS AND AN INFLUX OF DRIER AIR SHOULD ALLOW TEMPS
TO FALL INTO THE MID 40S TO MID 50S RANGE WITH THE WARMER TEMPS
NEAR LAKE MI. WI TO GET ON THE BACKSIDE OF THIS RETREATING AREA OF
HI PRES ON FRI AS WINDS BACK TO THE S-SE. WAA WL GRADUALLY WORK
ACROSS THE AREA AS 8H TEMPS CLIMB TO AROUND +15C BY 00Z SAT. TEMPS
WL RESPOND WITH READINGS TOPPING OUT MAINLY IN THE MID 70S TO
AROUND 80 DEGS.
QUIET AND MILDER CONDITIONS EXPECTED FOR FRI NGT AS NE WI TO SIT
BETWEEN HI PRES TO OUR EAST AND DEVELOPING LOW PRES WELL TO OUR
WEST. BOUNDARY LAYER WINDS ARE FCST TO INCREASE THRU THE NGT AND
KEEP THE ATMOSPHERE MIXED...THEREBY PREVENTING TEMPS FROM FALLING
TOO FAR. LOOK FOR MINS TO RANGE FROM THE MID 50S TO AROUND 60 DEGS
NORTH...LWR 60S SOUTH. ATTENTION TO BE FOCUSED ON THE MOVEMENT OF
A SHARP SHORTWAVE TROF/ATTENDANT SFC CDFNT PROGGED TO REACH THE
NRN PLAINS ON SAT. THIS SYSTEM TO STILL BE TOO FAR AWAY TO IMPACT
NE WI...OTHER THAN BRING A BLUSTERY AND WARM DAY TO THE REGION.
MAX TEMPS WL RANGE FROM AROUND 80 DEGS NORTH/LAKESHORE...LWR 80S
SOUTH.
THE SHORTWAVE TROF TO PUSH EAST INTO THE UPR MS VALLEY SAT NGT...
AS THE CDFNT REACHES WRN WI BY DAYBREAK. EVEN THO INSTABILITY AND
FORCING ARE SOMEWHAT MARGINAL...THERE IS GOOD LIFT FROM THE CDFNT
AND THE 0-6KM BULK SHEAR VALUES ARE GREATER THAN 40 KTS
APPROACHING CNTRL WI LATE SAT NGT. HIGHEST POPS PLACED OVER CNTRL
WI WITH A POTENTIAL FOR PARTS OF ERN WI TO STAY DRY THRU THE NGT.
FCST CONFIDENCE IS A BIT BETTER NOW FOR SUNDAY AND BEYOND NOW THAT
THE 00Z ECMWF HAS KEPT THIS SHORTWAVE TROF PROGRESSIVE AND NOT TRY
TO CLOSE THE TROF INTO AN UPR LOW. PCPN CHCS WL CONT FOR SUNDAY AS
THE UPR TROF AND CDFNT MOVE THRU THE FCST AREA. TOKEN SMALL POPS
WERE LEFT IN THE FCST FOR MON AND TUE DUE TO THE UNCERTAINTY OF
THE MODELS HANDLING THIS SHORTWAVE TROF CORRECTLY. IF THE NEW 12Z
MODEL OUTPUTS ARE SIMILAR TO THE 00Z RUN...THEN POPS COULD BE
DROPPED FOR BOTH MON AND TUE WITH MORE SUNSHINE. ONE THING THAT IS
MORE CERTAIN WOULD BE THE DROP IN TEMPS BEHIND THE CDFNT FOR EARLY
NEXT WEEK. THIS WOULD BE ESPECIALLY TRUE ON MON WITH MAX TEMPS IN
THE UPR 60S TO THE LWR HALF OF THE 70S.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1228 PM CDT WED AUG 19 2015
OCCLUDED FRONT EXTENDED FROM LAND O LAKES TO NEAR MENOMINEE
MICHIGAN EARLY THIS AFTERNOON. SCATTERED SHOWERS AND PERHAPS
A FEW ISOLATED THUNDERSTORMS. THE STRONGEST STORMS WERE OVER
NORTHERN MARINETTE COUNTY. THE OCCLUDED FRONT WILL CONTINUE TO
PUSH TO THE NORTHEAST INTO UPPER MICHIGAN THIS AFTERNOON.
MEANWHILE...UPPER LOW IS EXPECTED TO MOVE EAST. A NEW WRINKLE
TO THE FORECAST FOR LATER TONIGHT IS THE INCREASED CHANCES FOR
SHOWERS AS AN UPPER LEVEL DISTURBANCE SWINGS AROUND THE UPPER LOW.
ADDED MORE RAIN TO THE FORECAST FOR THE KATW/KGRB/KMTW 18Z TAFS
FROM 06Z TO 12Z.
GUSTY SOUTHWEST WINDS WILL DIMINISH AROUND 00Z...WITH GUSTY
WEST WINDS TO AROUND 20 KNOTS EXPECTED AFTER 15Z THURSDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
BEACH HAZARDS STATEMENT UNTIL 8 PM CDT THIS EVENING FOR
WIZ022-040-050.
&&
$$
SHORT TERM.....MPC
LONG TERM......KALLAS
AVIATION.......ECKBERG
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
608 AM CDT WED AUG 19 2015
UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND THURSDAY
ISSUED AT 305 AM CDT WED AUG 19 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR ANALYSIS SHOW OCCLUDED
LOW PRESSURE SPINNING OVER SOUTHERN MINNESOTA AND A COLD FRONT
ARCING SOUTHWARD OVER EASTERN IOWA AND CENTRAL MISSOURI. A PRE-
FRONTAL TROUGH IN COMBINATION WITH A SHORTWAVE IS PUSHING A BROKEN
BAND OF SHOWERS NORTHEAST OVER NORTH-CENTRAL AND FAR NORTHEAST WI
EARLY THIS MORNING. THESE SHOWERS SHOULD DEPART BY 12Z. ADDITIONAL
LIGHT SHOWERS ARE OCCURRING ALONG THE COLD FRONT...WHICH WILL BE
REACHING CENTRAL WI BY 12Z. AS LOW PRESSURE AND COLD FRONT MOVE
NORTHEAST...PRECIP TRENDS ARE THE MAIN FORECAST CONCERNS.
TODAY...OCCLUDED LOW PRESSURE WILL LIFT INTO NORTHWEST WISCONSIN
EARLY THIS AFTERNOON AND INTO CENTRAL LAKE SUPERIOR BY EARLY THIS
EVENING. MEANWHILE THE COLD FRONT WILL MOVE ACROSS MOST OF THE
FORECAST AREA THIS MORNING EXCEPT FOR THE DOOR PENINSULA...WHICH
SHOULD OCCUR EARLY THIS AFTERNOON. SCATTERED SHOWERS WILL ACCOMPANY
THE COLD FRONT. BUT WITH DAYTIME HEATING...PROGGED SOUNDINGS
INDICATE THAT 500-800 J/KG OF CAPE COULD DEVELOP OVER NE WI AHEAD OF
THE FRONT. AS A RESULT...NOT OUT OF THE QUESTION THAT A FEW
THUNDERSTORMS COULD POP UP BY LATE IN THE MORNING ALONG THE
BOUNDARY. ANY THUNDERSTORMS WILL BE CAPABLE OF TRANSFERRING HIGHER
WINDS ALOFT TO THE SURFACE SO WILL KEEP A MENTION OF GUSTY WINDS
WITH ANY THUNDERSTORMS IN THE HWO. BEHIND THE FRONT...SOUTHWEST
WINDS WILL BECOME BREEZY IN THE AFTERNOON WITH SOME GUSTS TO 35 MPH
POSSIBLE. WRAP AROUND SHOWERS COULD ALSO MOVE INTO CENTRAL AND
NORTH-CENTRAL WI BY MID TO LATE AFTERNOON. HIGHS RANGING FROM THE
MID 60S WEST TO MID 70S EAST.
TONIGHT...THE UPPER TROUGH MOVES OVERHEAD AS THE SHORTWAVE IN THE
BASE OF THE TROUGH LIFTS NORTHWARD OVER EASTERN WISCONSIN. DEEPER
MOISTURE WILL ACCOMPANY THE TROUGH...WITH MOISTURE EXTENDING UPWARDS
OF 700MB OVERNIGHT. ANY BREAKS IN THE CLOUDS OVER EASTERN WISCONSIN
AT THE START OF THE NIGHT WILL THEREFORE LIKELY FILL IN AS THE
EVENING PROGRESSES AND WILL SPREAD A SLIGHT CHANCE OF RAIN ALL THE
WAY TO THE LAKESHORE. THE MORE PERSISTENT RAINS SHOULD FALL OVER
NORTH-CENTRAL WI WHERE A SURFACE TROUGH WILL MOVE THROUGH. LOWS
MAINLY IN THE 50S.
THURSDAY...THE UPPER TROUGH WILL CONTINUE TO BE OVERHEAD DURING THE
MORNING....WHICH SHOULD LEAD TO SCATTERED SHOWERS AND SPOTTY
DRIZZLE. THEN THE LIGHT PRECIP SHOULD COME TO AN END IN THE
AFTERNOON AS THE TROUGH LIFTS TO THE NORTHEAST. HIGHS RANGING FROM
THE LOW 60S NORTH TO LOW 70S SOUTH.
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY
ISSUED AT 305 AM CDT WED AUG 19 2015
THE TWO MAIN WEATEHR FEATURES TO KEY ON DURING THE EXTENDED PERIOD
WL BE THE MOVEMENT OF THE NEXT PROMINENT SHORTWAVE TROF/ASSOCIATED
CDFNT ACROSS THE NRN TIER OF STATES THIS WEEKEND INTO EARLY NEXT
WEEK AND THE BUILDING OF AN UPR RDG OVER THE HI PLAINS. THE MAIN
STICKING POINT AMONG THE MODELS IS WHETHER THIS SHORTWAVE TROF WL
BE PROGRESSIVE OR CLOSE OFF INTO AN UPR LOW SOMEWHERE NEAR THE
GREAT LAKES. THE ANSWER TO THIS QUESTION WOULD GO A LONG WAY IN
DETERMINING THE WEATEHR IN OUR AREA FROM SUNDAY THRU TUE. AFTER A
BRIEF WARM-UP THRU SAT...TEMPS ARE EXPECTED TO FALL BELOW NORMAL
FOR THE FIRST HALF OF NEXT WEEK.
THE GREAT LAKES REGION TO RESIDE ON THE NRN FRINGES OF AN AREA OF
HI PRES MOVING ALONG THE OHIO RIVER VALLEY THU NGT. CLEARING
SKIES...LIGHT WINDS AND AN INFLUX OF DRIER AIR SHOULD ALLOW TEMPS
TO FALL INTO THE MID 40S TO MID 50S RANGE WITH THE WARMER TEMPS
NEAR LAKE MI. WI TO GET ON THE BACKSIDE OF THIS RETREATING AREA OF
HI PRES ON FRI AS WINDS BACK TO THE S-SE. WAA WL GRADUALLY WORK
ACROSS THE AREA AS 8H TEMPS CLIMB TO AROUND +15C BY 00Z SAT. TEMPS
WL RESPOND WITH READINGS TOPPING OUT MAINLY IN THE MID 70S TO
AROUND 80 DEGS.
QUIET AND MILDER CONDITIONS EXPECTED FOR FRI NGT AS NE WI TO SIT
BETWEEN HI PRES TO OUR EAST AND DEVELOPING LOW PRES WELL TO OUR
WEST. BOUNDARY LAYER WINDS ARE FCST TO INCREASE THRU THE NGT AND
KEEP THE ATMOSPHERE MIXED...THEREBY PREVENTING TEMPS FROM FALLING
TOO FAR. LOOK FOR MINS TO RANGE FROM THE MID 50S TO AROUND 60 DEGS
NORTH...LWR 60S SOUTH. ATTENTION TO BE FOCUSED ON THE MOVEMENT OF
A SHARP SHORTWAVE TROF/ATTENDANT SFC CDFNT PROGGED TO REACH THE
NRN PLAINS ON SAT. THIS SYSTEM TO STILL BE TOO FAR AWAY TO IMPACT
NE WI...OTHER THAN BRING A BLUSTERY AND WARM DAY TO THE REGION.
MAX TEMPS WL RANGE FROM AROUND 80 DEGS NORTH/LAKESHORE...LWR 80S
SOUTH.
THE SHORTWAVE TROF TO PUSH EAST INTO THE UPR MS VALLEY SAT NGT...
AS THE CDFNT REACHES WRN WI BY DAYBREAK. EVEN THO INSTABILITY AND
FORCING ARE SOMEWHAT MARGINAL...THERE IS GOOD LIFT FROM THE CDFNT
AND THE 0-6KM BULK SHEAR VALUES ARE GREATER THAN 40 KTS
APPROACHING CNTRL WI LATE SAT NGT. HIGHEST POPS PLACED OVER CNTRL
WI WITH A POTENTIAL FOR PARTS OF ERN WI TO STAY DRY THRU THE NGT.
FCST CONFIDENCE IS A BIT BETTER NOW FOR SUNDAY AND BEYOND NOW THAT
THE 00Z ECMWF HAS KEPT THIS SHORTWAVE TROF PROGRESSIVE AND NOT TRY
TO CLOSE THE TROF INTO AN UPR LOW. PCPN CHCS WL CONT FOR SUNDAY AS
THE UPR TROF AND CDFNT MOVE THRU THE FCST AREA. TOKEN SMALL POPS
WERE LEFT IN THE FCST FOR MON AND TUE DUE TO THE UNCERTAINTY OF
THE MODELS HANDLING THIS SHORTWAVE TROF CORRECTLY. IF THE NEW 12Z
MODEL OUTPUTS ARE SIMILAR TO THE 00Z RUN...THEN POPS COULD BE
DROPPED FOR BOTH MON AND TUE WITH MORE SUNSHINE. ONE THING THAT IS
MORE CERTAIN WOULD BE THE DROP IN TEMPS BEHIND THE CDFNT FOR EARLY
NEXT WEEK. THIS WOULD BE ESPECIALLY TRUE ON MON WITH MAX TEMPS IN
THE UPR 60S TO THE LWR HALF OF THE 70S.
&&
.AVIATION...FOR 12Z TAF ISSUANCE
ISSUED AT 608 AM CDT WED AUG 19 2015
SHOWERS AND A FEW THUNDERSTORMS WILL IMPACT THE TAF SITES THIS
MORNING ALONG A QUICK MOVING COLD FRONT. THIS LINE OF SHOWERS COULD
POSSIBLY PRODUCE STRONG GUSTY WINDS TO AROUND 35 KNOTS. BEHIND THE
FRONT...A TIGHT PRESSURE GRADIENT WILL CAUSE GUSTY SYNOPTIC WINDS OF
25 TO 30 KNOTS DURING THE LATE MORNING AND AFTERNOON HOURS. UPPER
LEVEL LOW PRESSURE WILL MOVE OVERHEAD TONIGHT. CIGS WILL QUICKLY
FALL TO IFR/LIFR OVER CENTRAL AND NORTH-CENTRAL WI...BUT WILL NOT
CRASH UNTIL OVERNIGHT OVER THE EAST. SCATTERED SHOWERS ARE LIKELY
TONIGHT WHICH WILL TEMPORARILY DROP VSBYS TO MVFR.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
BEACH HAZARDS STATEMENT THROUGH THIS EVENING FOR WIZ022-040-050.
&&
$$
SHORT TERM.....MPC
LONG TERM......KALLAS
AVIATION.......MPC
FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND THURSDAY
ISSUED AT 305 AM CDT WED AUG 19 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR ANALYSIS SHOW OCCLUDED
LOW PRESSURE SPINNING OVER SOUTHERN MINNESOTA AND A COLD FRONT
ARCING SOUTHWARD OVER EASTERN IOWA AND CENTRAL MISSOURI. A PRE-
FRONTAL TROUGH IN COMBINATION WITH A SHORTWAVE IS PUSHING A BROKEN
BAND OF SHOWERS NORTHEAST OVER NORTH-CENTRAL AND FAR NORTHEAST WI
EARLY THIS MORNING. THESE SHOWERS SHOULD DEPART BY 12Z. ADDITIONAL
LIGHT SHOWERS ARE OCCURRING ALONG THE COLD FRONT...WHICH WILL BE
REACHING CENTRAL WI BY 12Z. AS LOW PRESSURE AND COLD FRONT MOVE
NORTHEAST...PRECIP TRENDS ARE THE MAIN FORECAST CONCERNS.
TODAY...OCCLUDED LOW PRESSURE WILL LIFT INTO NORTHWEST WISCONSIN
EARLY THIS AFTERNOON AND INTO CENTRAL LAKE SUPERIOR BY EARLY THIS
EVENING. MEANWHILE THE COLD FRONT WILL MOVE ACROSS MOST OF THE
FORECAST AREA THIS MORNING EXCEPT FOR THE DOOR PENINSULA...WHICH
SHOULD OCCUR EARLY THIS AFTERNOON. SCATTERED SHOWERS WILL ACCOMPANY
THE COLD FRONT. BUT WITH DAYTIME HEATING...PROGGED SOUNDINGS
INDICATE THAT 500-800 J/KG OF CAPE COULD DEVELOP OVER NE WI AHEAD OF
THE FRONT. AS A RESULT...NOT OUT OF THE QUESTION THAT A FEW
THUNDERSTORMS COULD POP UP BY LATE IN THE MORNING ALONG THE
BOUNDARY. ANY THUNDERSTORMS WILL BE CAPABLE OF TRANSFERRING HIGHER
WINDS ALOFT TO THE SURFACE SO WILL KEEP A MENTION OF GUSTY WINDS
WITH ANY THUNDERSTORMS IN THE HWO. BEHIND THE FRONT...SOUTHWEST
WINDS WILL BECOME BREEZY IN THE AFTERNOON WITH SOME GUSTS TO 35 MPH
POSSIBLE. WRAP AROUND SHOWERS COULD ALSO MOVE INTO CENTRAL AND
NORTH-CENTRAL WI BY MID TO LATE AFTERNOON. HIGHS RANGING FROM THE
MID 60S WEST TO MID 70S EAST.
TONIGHT...THE UPPER TROUGH MOVES OVERHEAD AS THE SHORTWAVE IN THE
BASE OF THE TROUGH LIFTS NORTHWARD OVER EASTERN WISCONSIN. DEEPER
MOISTURE WILL ACCOMPANY THE TROUGH...WITH MOISTURE EXTENDING UPWARDS
OF 700MB OVERNIGHT. ANY BREAKS IN THE CLOUDS OVER EASTERN WISCONSIN
AT THE START OF THE NIGHT WILL THEREFORE LIKELY FILL IN AS THE
EVENING PROGRESSES AND WILL SPREAD A SLIGHT CHANCE OF RAIN ALL THE
WAY TO THE LAKESHORE. THE MORE PERSISTENT RAINS SHOULD FALL OVER
NORTH-CENTRAL WI WHERE A SURFACE TROUGH WILL MOVE THROUGH. LOWS
MAINLY IN THE 50S.
THURSDAY...THE UPPER TROUGH WILL CONTINUE TO BE OVERHEAD DURING THE
MORNING....WHICH SHOULD LEAD TO SCATTERED SHOWERS AND SPOTTY
DRIZZLE. THEN THE LIGHT PRECIP SHOULD COME TO AN END IN THE
AFTERNOON AS THE TROUGH LIFTS TO THE NORTHEAST. HIGHS RANGING FROM
THE LOW 60S NORTH TO LOW 70S SOUTH.
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY
ISSUED AT 305 AM CDT WED AUG 19 2015
THE TWO MAIN WEATEHR FEATURES TO KEY ON DURING THE EXTENDED PERIOD
WL BE THE MOVEMENT OF THE NEXT PROMINENT SHORTWAVE TROF/ASSOCIATED
CDFNT ACROSS THE NRN TIER OF STATES THIS WEEKEND INTO EARLY NEXT
WEEK AND THE BUILDING OF AN UPR RDG OVER THE HI PLAINS. THE MAIN
STICKING POINT AMONG THE MODELS IS WHETHER THIS SHORTWAVE TROF WL
BE PROGRESSIVE OR CLOSE OFF INTO AN UPR LOW SOMEWHERE NEAR THE
GREAT LAKES. THE ANSWER TO THIS QUESTION WOULD GO A LONG WAY IN
DETERMINING THE WEATEHR IN OUR AREA FROM SUNDAY THRU TUE. AFTER A
BRIEF WARM-UP THRU SAT...TEMPS ARE EXPECTED TO FALL BELOW NORMAL
FOR THE FIRST HALF OF NEXT WEEK.
THE GREAT LAKES REGION TO RESIDE ON THE NRN FRINGES OF AN AREA OF
HI PRES MOVING ALONG THE OHIO RIVER VALLEY THU NGT. CLEARING
SKIES...LIGHT WINDS AND AN INFLUX OF DRIER AIR SHOULD ALLOW TEMPS
TO FALL INTO THE MID 40S TO MID 50S RANGE WITH THE WARMER TEMPS
NEAR LAKE MI. WI TO GET ON THE BACKSIDE OF THIS RETREATING AREA OF
HI PRES ON FRI AS WINDS BACK TO THE S-SE. WAA WL GRADUALLY WORK
ACROSS THE AREA AS 8H TEMPS CLIMB TO AROUND +15C BY 00Z SAT. TEMPS
WL RESPOND WITH READINGS TOPPING OUT MAINLY IN THE MID 70S TO
AROUND 80 DEGS.
QUIET AND MILDER CONDITIONS EXPECTED FOR FRI NGT AS NE WI TO SIT
BETWEEN HI PRES TO OUR EAST AND DEVELOPING LOW PRES WELL TO OUR
WEST. BOUNDARY LAYER WINDS ARE FCST TO INCREASE THRU THE NGT AND
KEEP THE ATMOSPHERE MIXED...THEREBY PREVENTING TEMPS FROM FALLING
TOO FAR. LOOK FOR MINS TO RANGE FROM THE MID 50S TO AROUND 60 DEGS
NORTH...LWR 60S SOUTH. ATTENTION TO BE FOCUSED ON THE MOVEMENT OF
A SHARP SHORTWAVE TROF/ATTENDANT SFC CDFNT PROGGED TO REACH THE
NRN PLAINS ON SAT. THIS SYSTEM TO STILL BE TOO FAR AWAY TO IMPACT
NE WI...OTHER THAN BRING A BLUSTERY AND WARM DAY TO THE REGION.
MAX TEMPS WL RANGE FROM AROUND 80 DEGS NORTH/LAKESHORE...LWR 80S
SOUTH.
THE SHORTWAVE TROF TO PUSH EAST INTO THE UPR MS VALLEY SAT NGT...
AS THE CDFNT REACHES WRN WI BY DAYBREAK. EVEN THO INSTABILITY AND
FORCING ARE SOMEWHAT MARGINAL...THERE IS GOOD LIFT FROM THE CDFNT
AND THE 0-6KM BULK SHEAR VALUES ARE GREATER THAN 40 KTS
APPROACHING CNTRL WI LATE SAT NGT. HIGHEST POPS PLACED OVER CNTRL
WI WITH A POTENTIAL FOR PARTS OF ERN WI TO STAY DRY THRU THE NGT.
FCST CONFIDENCE IS A BIT BETTER NOW FOR SUNDAY AND BEYOND NOW THAT
THE 00Z ECMWF HAS KEPT THIS SHORTWAVE TROF PROGRESSIVE AND NOT TRY
TO CLOSE THE TROF INTO AN UPR LOW. PCPN CHCS WL CONT FOR SUNDAY AS
THE UPR TROF AND CDFNT MOVE THRU THE FCST AREA. TOKEN SMALL POPS
WERE LEFT IN THE FCST FOR MON AND TUE DUE TO THE UNCERTAINTY OF
THE MODELS HANDLING THIS SHORTWAVE TROF CORRECTLY. IF THE NEW 12Z
MODEL OUTPUTS ARE SIMILAR TO THE 00Z RUN...THEN POPS COULD BE
DROPPED FOR BOTH MON AND TUE WITH MORE SUNSHINE. ONE THING THAT IS
MORE CERTAIN WOULD BE THE DROP IN TEMPS BEHIND THE CDFNT FOR EARLY
NEXT WEEK. THIS WOULD BE ESPECIALLY TRUE ON MON WITH MAX TEMPS IN
THE UPR 60S TO THE LWR HALF OF THE 70S.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1054 PM CDT TUE AUG 18 2015
SHOWERS AND A FEW THUNDERSTORMS WILL CONTINUE TO IMPACT THE TAF
SITES DURING THE OVERNIGHT HOURS. FOR NOW THE MAIN THUNDERSTORM
ACTIVITY IS EXPECTED TO BE CONFINED TO MTW WHERE AN AREA OF
THUNDERSTORMS IS TRACKING NORTH. ONCE THE MAIN SHOWERS PASS
LINGERING LIGHT SHOWERS AND DRIZZLE WILL REMAIN WITH MVFR/IFR
CONDITIONS. THERE IS SOME POTENTIAL FOR A LINE OF SHOWERS TO
REDEVELOP WITH THE COLD FRONT ON WEDNESDAY...MAINLY FROM 13Z TO
17Z AS THE LINE OF SHOWERS WILL RACE NORTHEAST. THIS LINE OF
SHOWERS COULD POSSIBLY PRODUCE STRONG GUSTY WINDS TO AROUND 40
KNOTS. A TIGHT PRESSURE GRADIENT WILL CAUSE GUSTY SYNOPTIC WINDS
OF 25 TO 30 KNOTS DURING THE DAY ON WEDNESDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
BEACH HAZARDS STATEMENT FROM 7 AM CDT THIS MORNING THROUGH THIS
EVENING FOR WIZ022-040-050.
&&
$$
SHORT TERM.....MPC
LONG TERM......KALLAS
AVIATION.......KURIMSKI
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
339 AM EDT FRI AUG 21 2015
.DISCUSSION...
TODAY...GPS PRECIPITABLE WATER VALUES WERE A LITTLE ABOVE 2
INCHES EARLY THIS MORNING. RECENT CLOUD TRENDS SHOW DEBRIS CLOUDS
THINNING OUT SO THERE WILL BE AMPLE MORNING HEATING. HOWEVER...THE
LATEST RAP ANALYSIS SHOWS 700MB TEMPS 10-11 CELSIUS...WHICH
USUALLY INDICATES DEEP CONVECTIVE DEVELOPMENT WILL BE DELAYED
SOME.
THE AXIS OF A WEAKENING SURFACE RIDGE OVER NORTH BAHAMAS WILL
PROVIDE LIGHT WEST/SOUTHWEST WINDS THIS MORNING...DELAYING THE
ONSET OF EAST COAST SEA BREEZE UNTIL NOON TO EARLY AFTERNOON. THIS
WILL ALLOW SOME HEAT INDEX READINGS TO REACH 100-105 BEFORE
CONVECTION INITIATES. ADDITIONALLY...THIS HOT/SULTRY AIR MASS WILL
ALLOW FOR A CHANCE OF STORMS ALONG THE COAST BEFORE THE SEA BREEZE
PUSHES WELL INLAND. THE STRONGEST BOUNDARY INTERACTIONS WILL OCCUR
OVER THE INTERIOR DURING THE LATE AFTERNOON TO EARLY EVENING.
MOS POPS CAME IN 30 PERCENT RIGHT ALONG THE COAST AND ONLY 30-50
PERCENT OVER THE INTERIOR. HAVE FOLLOWED THIS DOWNWARD TREND BUT
KEPT THE INTERIOR POPS AT 50 PERCENT.
FREQUENT LIGHTNING STRIKES IN STRONGER STORMS ARE LIKELY MAINLY
OVER THE INTERIOR. WEAK STEERING FLOW INDICATES A CONTINUED
POTENTIAL FOR QUICK 2-3 INCH RAIN AMOUNTS. GFS FORECAST SOUNDINGS
SHOW A LITTLE MID LEVEL DRYING DURING THE DAY SO A THREAT FOR
DOWNBURST WINDS 40-50 KNOTS ARE POSSIBLE TOO.
SAT-SUN...MID-LEVEL HIGH PRESSURE OVER THE GOMEX GRADUALLY
WEAKENS LATE SUN/SUN NIGHT AS SHORTWAVE IMPULSES TRAVERSE THE N/NE
PERIPHERY OF THIS ANTI-CYCLONE. THIS WILL ALLOW NORTHERLY WINDS TO
BACK TO NORTHWESTERLY. 500 MB TEMPERATURES WILL REMAIN FAIRLY WARM
AT -5C/- 6C. AT THE SURFACE HIGH PRESSURE ACROSS THE EASTERN CONUS
WILL WEAKEN AND DRIFT TOWARD THE EASTERN SEABOARD/WESTERN ATLC
WITH THE APPROACH OF A COLD FRONT. THE SURFACE PRESSURE GRADIENT
WILL REMAIN WEAK THROUGH THIS PERIOD WITH LIGHT NORTHEASTERLY
FLOW. THE EAST COAST SEA BREEZE WILL DEVELOP EACH DAY AND PUSH
INLAND. GREATEST STORM CHANCES WILL FAVOR THE INTERIOR EACH
AFTERNOON WITH STEERING FLOW FROM THE N/NNE.
MON-THU...TROUGHING IN THE MID-LEVELS WILL GRADUALLY DEVELOP ACROSS
THE EASTERN CONUS THROUGH THIS TIME AS NWRLY FLOW ALOFT BECOMES
SWRLY ACROSS THE AREA. DEEP LAYER MOISTURE WILL BE LOWER THAN
PREVIOUS DAYS. A WEAK SURFACE BOUNDARY WILL BECOME NEAR STATIONARY
ACROSS THE DEEP SOUTH WITH WEAK HIGH PRESSURE CONTINUING OVER ECFL.
OUR LIGHT ONSHORE FLOW WILL BECOME LIGHT S/SWRLY WED-THU THOUGH THE
EAST COAST SEA BREEZE WILL STILL DEVELOP EACH AFTERNOON AND PUSH
INLAND. NORTHERLY STORM STEERING FLOW WILL CONTINUE MON-TUE WITH
LOWER CONFIDENCE WED-THU IN STORM MOTION...THOUGH IT APPEARS TO BE
LIGHT/ERRATIC FOR NOW. LOWER THAN NORMAL PRECIPITATION CHANCES LIKELY
MON-TUE WITH AN UPTICK AGAIN MOVING INTO/PAST MID-WEEK TOWARDS CLIMO
NUMBERS.
&&
.AVIATION...MAINLY VFR UNTIL STORMS START FIRING THIS AFTERNOON.
ALL OF THE COASTAL SITES WILL HAVE A CHANCE OF STORMS FROM ABOUT
16-20Z. OUTFLOW BOUNDARY MERGERS WILL PROPAGATE STORMS TO THE
INTERIOR TERMINALS WITH THE GREATEST CHANCE ABOUT 19-23Z. CANNOT
PIN DOWN WHICH TERMINALS WILL BE AFFECTED BY STRONG STORMS...BUT
INTERIOR SITES WILL HAVE A SLIGHT CHANCE FOR TORRENTIAL DOWNPOURS...
FREQUENT LIGHTNING STRIKES AND GUSTY WINDS ABOVE 35 KNOTS.
&&
.MARINE...
TODAY-TONIGHT...WEAK PRESSURE GRADIENT TYPICAL OF THE AUGUST
DOLDRUMS WILL CONTINUE SO THERE ARE NO WIND/SEA CONCERNS. WEAK
STEERING TODAY SHOULD CONFINE STORM POTENTIAL TO THE MAINLAND BUT
A FEW COULD AFFECT THE INTRACOASTAL...ESPECIALLY FROM THE CAPE
NORTHWARD DURING THE EARLY TO MID AFTERNOON.
WEEKEND...WEAK PRESSURE GRADIENT OVER THE AREA WITH A LIGHT N/NE
WIND FLOW BELOW 10 KTS. GRADIENT IS SO WEAK THAT WINDS MAY BE MORE
VARIABLE IN DIRECTION AT TIMES. THE ECSB WILL DEVELOP EACH AFTERNOON
PUSHING INLAND WITH A SLIGHT BUMP UP IN SPEEDS NEAR THE IMMEDIATE
COAST. ONLY AN ISOLD THREAT FOR SHRA/TSRA. SEA HEIGHTS AOB 3 FT.
MON-TUE...THE WEAK PRESSURE GRADIENT AND LIGHT WIND FIELDS CONTINUE
INTO EARLY WEEK AS A WEAK FRONTAL BOUNDARY SETTLES ACROSS THE DEEP
SOUTH/SOUTHEAST U.S. DAILY SEA BREEZE FORMATION AND PUSH INLAND
DURING THE AFTERNOON WILL ALSO REMAIN COMMON. SHOWER/STORM CHANCES
REMAIN ISOLD. SEAS AOB 3 FT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 92 76 90 75 / 40 20 30 20
MCO 94 76 93 76 / 50 20 50 20
MLB 92 77 90 77 / 40 20 30 20
VRB 92 74 89 75 / 40 20 30 20
LEE 94 77 94 77 / 50 20 50 20
SFB 94 77 93 77 / 50 20 40 20
ORL 95 78 94 77 / 50 20 50 20
FPR 92 73 89 74 / 40 20 30 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...LASCODY
LONG TERM....SEDLOCK
AREA FORECAST DISCUSSION
NWS MIAMI FL
138 AM EDT FRI AUG 21 2015
.AVIATION...
VFR WILL PREVAIL OVERNIGHT. A WEAK LAND BREEZE DEVELOPING COULD
ALLOW FOR SCATTERED THUNDERSTORMS TO DEVELOP ACROSS THE EAST
COAST BY MID MORNING FRI THEN OVER THE INTERIOR WITH MOVEMENT TO
THE GULF COAST THROUGH THE DAY. ADDED VCTS FOR ALL TERMINALS GIVEN
THIS REGIME EXPECTED. ANY DIRECT TSRA IMPACTS WOULD BE BRIEF, BUT
BRIEF IFR WILL BE POSSIBLE IN HEAVY RAIN. /GREGORIA
&&
.PREV DISCUSSION... /ISSUED 758 PM EDT THU AUG 20 2015/
AVIATION...
SLIGHTLY WEAKER WIND FLOW WILL BE THE ONLY CHANGE TO THE CURRENT
REGIME ON FRIDAY. IN ADDITION, A WEAKER OR NO SUBSIDENCE CAP MAY
LEAD TO MORE NUMEROUS STORMS, SOME OF WHICH MAY BE CLOSER TO THE
EAST COAST TAF SITES. HOWEVER, WITH FOCUS STILL OVER THE INTERIOR,
AND NOT A GREAT DEAL OF CONFIDENCE, WILL NOT ADD VCTS AT THIS
TIME TO THE EAST COAST. A BRIEF MVFR CIG CAN OCCUR ONCE AGAIN NEAR
DAWN UNDER EAST FLOW.
PREV DISCUSSION... /ISSUED 747 PM EDT THU AUG 20 2015/
UPDATE...
MAKING SOME MINOR ADJUSTMENTS TO THE EVENING UPDATES BASED ON
LATEST TRENDS. EARLY EVENING ACTIVITY SHOULD DIMINISH BY 02Z WITH THE
GRADIENT FLOW WEAKENING CONSIDERABLY SO THE CHANCES FOR ATLANTIC
DEVELOPMENT LATER TONIGHT MOVING ONSHORE SEEM RATHER REMOTE AT
THIS TIME. NEITHER THE HRRR NOR THE LOCALLY RUN WRF SHOW THIS
OCCURRING SO AM REMOVING MENTION OF THUNDER ALL AREAS WITH THE
EXCEPTION OF THE THE OFFSHORE WATERS FOR LATER TONIGHT.
KOB
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 77 92 78 92 / 20 40 30 40
FORT LAUDERDALE 79 92 79 91 / 20 50 40 50
MIAMI 79 94 78 92 / 30 50 40 50
NAPLES 78 91 77 93 / 30 50 40 50
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
346 AM CDT FRI AUG 21 2015
.SHORT TERM /TODAY/...
ISSUED AT 346 AM CDT FRI AUG 21 2015
MAIN FORECAST CONCERN WAS FOCUSED ON TEMPERATURES AND WINDS FOR
THIS AFTERNOON...AND WITH WEAK SHORTWAVE PROVIDING SOME ISOLATED
SHOWERS/STORMS THROUGH THE MID-MORNING. A FEW ELEVATED
SHOWERS/STORMS HAVE DEVELOPED OVER WEST-CENTRAL TO NORTHWEST IOWA
AND LOOK TO MEANDER INTO NORTH-CENTRAL IOWA THROUGH 15Z THIS
MORNING. THERE IS ENOUGH FORCING AND ELEVATED INSTABILITY...ALBEIT
VERY WEAK...BUT ENOUGH TO WARRANT SLIGHT/LOW CHANCE POPS OVER THE
NORTH. HOWEVER WITH A A STRONG CAP IN PLACE TODAY...IT WILL LIMIT
ANYTHING PAST 15Z. THE LATEST 21.07Z HRRR HAS A DECENT HANDLE ON
THE CONVECTIVE TRENDS AND LEANED TOWARD ITS SOLUTION FOR POPS/WX.
STRONG MIXING AND WAA DEVELOP TODAY AS PRESSURE GRADIENT TIGHTENS
THIS AFTERNOON. MIXING TO AROUND 850MB PUTS HIGHS IN THE LOWER 80S
AND TWEAKED MAX TEMPS UP SLIGHTLY. THE MAV/ECS HAD A GREAT HANDLE ON
TEMPS TODAY AS THE MET WAS TOO COLD THROUGHOUT THE FORECAST AREA.
ALSO TWEAKED UP WINDS SLIGHTLY AS WINDS ATOP THE MIXED LAYER IN THE
25-30 KNOT RANGE.
.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 346 AM CDT FRI AUG 21 2015
THE LONG TERM FORECAST IS CHARACTERIZED BY VARYING TEMPERATURES
AND MOSTLY DRY CONDITIONS BUT PUNCTUATED AND HEADLINED BY THE
STORM SYSTEM MOVING ACROSS THE REGION ON SATURDAY AND SATURDAY
NIGHT. THE DRIVER FOR THIS SYSTEM WILL COME IN THE FORM OF A
MID/UPPER LEVEL TROUGH...STRONG FOR THIS SEASON...MOVING ACROSS
THE NORTHERN ROCKIES ON FRIDAY NIGHT AND OVER THE DAKOTAS AND
MINNESOTA ON SATURDAY AND SATURDAY NIGHT. THIS WILL BE REFLECTED
AT THE SURFACE BY A STEADILY STRENGTHENING
TROUGH/FRONT...INITIALLY STRETCHING DOWN THE HIGH PLAINS AND THEN
SWEEPING EAST/SOUTHEAST IN RESPONSE TO THE PROGRESSION OF THE
MID/UPPER TROUGH ON SATURDAY/SATURDAY NIGHT. AHEAD OF THIS SYSTEM
MOST OF SATURDAY WILL BE WARM AND INCREASINGLY BREEZY ACROSS OUR
FORECAST AREA AS THE SURFACE PRESSURE GRADIENT TIGHTENS UP
BETWEEN THE HIGH PLAINS TROUGH AND A LARGE HIGH PRESSURE AREA
DEPARTING TO THE EAST. FOR MUCH OF THE DAY THINGS WILL REMAIN
QUIET...BUT BY PEAK HEATING IN THE LATE AFTERNOON/EVENING
INSTABILITY WILL BE MAXIMIZED AND THE SURFACE FRONT WILL SERVE AS
A MECHANISM FOR THUNDERSTORM DEVELOPMENT COINCIDENT WITH THE
ARRIVAL OF STRONGER FORCING AND WIND FIELDS ALOFT GIVEN THE
APPROACH OF THE MID/UPPER TROUGH. INITIAL STORMS WILL LIKELY BE
ORGANIZED WITHIN THIS ENVIRONMENT PROVIDING A FAIRLY SUBSTANTIAL
SEVERE WEATHER THREAT...THEN AS THE SYSTEM MOVES EAST/SOUTHEAST
WITH SUNSET THE STORMS SHOULD BECOME MORE LINEAR AND GRADUALLY
DIMINISH IN INTENSITY BY THE TIME THEY REACH EASTERN IOWA. FOR NOW
THE PRIMARY QUESTIONS ARE WHERE THE STORMS WILL INITIALLY
DEVELOP...OVER SOUTH DAKOTA/MINNESOTA/NEBRASKA OR OVER
WESTERN/NORTHWESTERN IOWA...AND HOW FAR EAST/SOUTHEAST THEY WILL
REMAIN SEVERE AS THEY MOVE QUICKLY ACROSS THE STATE. SPC PRODUCTS
HANDLE THE THREAT WELL AND WILL BE CLOSELY MONITORED TODAY AND
TOMORROW.
AFTER THE FRONT AND ASSOCIATED STORMS BLOW THROUGH ON SATURDAY
NIGHT WE WILL ONCE AGAIN SEE MOSTLY CLEAR...COOL...AND BREEZY
WEATHER FROM SUNDAY INTO EARLY NEXT WEEK. BY MONDAY THE 500 MB
PATTERN WILL FEATURE A DEEPENING GYRE OVER THE GREAT LAKES
REGION...THAT BEING THE SYSTEM THAT AFFECTED US ON
SATURDAY/SATURDAY NIGHT...WITH A DEVELOPING RIDGE OVER THE FOUR
CORNERS REGION. INITIALLY THIS WILL PLACE IOWA BENEATH PERSISTENT
NORTHWEST FLOW RESULTING IN A VERY SLOW WARMING TREND. BY MIDWEEK
AS THE EASTERN GYRE DEPARTS THE WESTERN RIDGE WILL BUILD FURTHER
AND APPROACH OUR AREA...BUT MOST OF THE HEAT BUBBLE SHOULD REMAIN
WEST/SOUTHWEST OF IOWA THROUGH AT LEAST WEDNESDAY. THERE ARE
CONSISTENT INDICATIONS THAT A SHORTWAVE WILL OVERTOP THE 500 MB
RIDGE SOMETIME AROUND THURSDAY...POSSIBLY PROVIDING US WITH
ANOTHER CHANCE FOR RAIN BUT MORE IMPORTANTLY SHUNTING THE RIDGE
SOUTHWARD FOR A DAY OR TWO. BEYOND THIS...LOOKING TOWARD THE NEXT
WEEKEND OR SO...IT REMAINS UNCERTAIN WHETHER THE LARGE RIDGE WILL
BE ABLE TO BUILD UP OVER THE MIDWEST OR WILL REMAIN JUST TO OUR
SOUTHWEST. THIS WILL DETERMINE WHETHER WE GET ONE LAST BLAST OF
SUMMER HEAT OR NOT.
&&
.AVIATION...21/06Z
ISSUED AT 1149 PM CDT THU AUG 20 2015
VFR CONDITIONS EXPECTED THROUGH THE FORECAST PERIOD WITH MID
CLOUDS TO MOVE IN OVERNIGHT. STILL SOME ISOLATED SHRA/TSRA
POSSIBLE LATE TONIGHT INTO EARLY FRIDAY...COULD IMPACT KFOD AND
KMCW. STILL HAVE LEFT OUT OF THE TAF GIVEN THE UNCERTAINTY AND
WIDELY SCATTERED NATURE OF THE EXPECTED STORMS. SOUTHERLY WINDS TO
PICK UP FRIDAY...AND DIMINISH AGAIN FRIDAY EVENING.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...LEE
AVIATION...BEERENDS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
352 AM MDT FRI AUG 21 2015
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 330 AM MDT FRI AUG 21 2015
FORECAST CONCERNS WILL BE THUNDERSTORM CHANCES INTO THE BEGINNING OF
THE WEEKEND AND HOW COOL TO MAKE IT SATURDAY NIGHT INTO SUNDAY
NIGHT. SATELLITE SHOWING AN AMPLIFIED/BLOCKY OVER THE PACIFIC. THIS
TRANSITIONS TO A BROAD TROUGH/WESTERLY ALOFT OVER MOST OF THE
COUNTRY. STRONG SYSTEM DIGGING INTO SOUTHWEST CANADA WITH SEVERAL
SHORTWAVE TROUGHS EMBEDDED IN THE WESTERLY FLOW.
AT JET LEVEL...MODELS DID WELL. AT MID LEVELS...THE GFS/CANADIAN AND
THE UKMET WERE DOING A LITTLE BETTER THAN THE ECMWF. THE SREF AND
ESPECIALLY THE NAM WERE NOT DOING WELL. THE GFS WAS DOING A LITTLE
BETTER THAN THE ECMWF WITH THE LOW LEVEL WIND FIELD. ALL MODELS
INITIALIZED WELL ON THE LOW LEVEL THERMAL FIELD
DIFFICULT AND UNCERTAIN PRECIPITATION FORECAST...ESPECIALLY
THROUGH THIS EVENING. CONFIDENCE IS BELOW AVERAGE FOR THE
PRECIPITATION FORECAST.
TODAY/TONIGHT...WILL HAVE TO KEEP AN EYE ON ANY LATE NIGHT/EARLY
MORNING DEVELOPMENT NEAR THE BOUNDARY JUST TO THE NORTH OF OUR
AREA. MODELS HAVE BEEN HINTING AT IT AND WILL CONTINUE TO MONITOR.
FOR YESTERDAYS THUNDERSTORMS...JUST ENOUGH MOISTURE ALONG A
BOUNDARY WITH A WEAK SHORTWAVE TROUGH WAS ABLE TO SPARK ISOLATED
THUNDERSTORMS OVER AND NEAR THE NORTHEAST PORTION OF THE AREA. NOT
TOO DIFFERENT A SETUP FOR TODAY FROM YESTERDAY. AGAIN WHAT MAKES
FORECAST UNCERTAIN IS THE MOISTURE AVAILABILITY...ESPECIALLY
ABOVE THE LOW LEVELS...WHERE DOES THE SURFACE TROUGH SETUP AND THE
WEAK/COMPLICATED MID LEVEL FORCING INVOLVED.
MODELS HAVE THE BOUNDARY PRETTY CLOSE BUT A LITTLE FURTHER WEST THAN
WHAT WAS SHOWN YESTERDAY. 700 MB SHORTWAVE EJECTS INTO THE PLAINS THIS
AFTERNOON AND IT LOOKS TO BE IN TWO PIECES. ONE PORTION GOES
ACROSS THE NORTH AND IS THE SLOWER OF THE TWO SHORTWAVE TROUGHS.
THE SECOND ONE GOES ACROSS TO OUR SOUTH AND BRUSHES THE SOUTHERN
PORTION OF THE AREA. THERE IS WEAK FORCING IN BETWEEN. ALSO THE
MODELS DIFFER ON HOW FAR EAST DURING THE DAY THEY MOVE THESE
SHORTWAVE TROUGHS.
CONVECTIVE ALLOWING MODELS ARE HAVING A DIFFICULT WITH ALL THIS. THE
ARW HAS LITTLE TO NOTHING. THE HRRR AND ESPECIALLY THE NMM DEVELOP
ROBUST CONVECTION OVER THE WESTERN PORTION OF THE AREA THIS
AFTERNOON CLOSE TO THE SURFACE TROUGH. THE 00Z NAM DID NOT INDICATE
ANYTHING BUT NOW THE 06Z NAM IS MATCHING UP WITH THE ABOVE TWO
MODELS. THE 00Z ECMWF EXPLODES CONVECTION OVER THE NORTHERN PORTION
OF THE AREA. ALL THIS TIME A RATHER STOUT EML LIES OVER THE AREA.
AFTER LOOKING AT THIS AND COLLABORATION...PULLED THE INITIATION A
LITTLE FURTHER WEST THAN BEFORE. THE PROBLEM THEN BECOMES HOW FAR
EAST TO TAKE THIS ACTIVITY. THE HRRR TAKES IT FURTHER EAST WHILE THE
REST OF THE OUTPUT THAT DID DEVELOP SOMETHING JUST KEEPS IT OVER
THE WEST AS IT EITHER DISSIPATES THE THUNDERSTORMS OR MOVES THEM
OF THE AREA TO THE NORTH OR SOUTH. SO DID LOWER POPS A LITTLE DUE
TO THIS.
IT DOES LOOK LIKE THE THUNDERSTORMS END BY 06Z. HOWEVER ELEVATED
STORMS/REDEVELOPMENT WILL NEED TO BE LOOKED AT AGAIN TO A LOW LEVEL
JET AND DECENT WARM AIR ADVECTION PATTERN ALOFT AHEAD OF ANOTHER
SHORTWAVE TROUGH. FOR THIS AFTERNOON AND EVENINGS CONVECTION...IF
STORMS DEVELOP...IT WILL BE POSSIBLE THAT THESE WILL BECOME SEVERE
DUE TO THE INSTABILITY AND LAPSE RATES INVOLVED. NO MATTER IF
STORMS DEVELOP OR NOT...BOUNDARY LAYER MOISTURE INCREASES AND AT
THE VERY LEAST A LOT OF STRATUS WILL DEVELOP WITH SOME PATCHY FOG
INVOLVED.
PRESSURE FALLS AND GRADIENT SUPPORT NEAR BREEZY OR BREEZY CONDITIONS.
GUIDANCE HAS BEEN RUNNING COOL ON MAXES HERE THE LAST FEW DAYS.
THE GFS/MAV HAS BEEN DOING THE BEST AND HAVE RAISED THE MAXES SOME.
SATURDAY/SATURDAY NIGHT...PATCHY FOG ENDS BY MID MORNING WITH THE
STRATUS LASTING A LITTLE LONGER. THERE ARE STILL DIFFERENCES IN
HOW FAST THE MODELS BRING IN THE COLD FRONT. THE NAM IS THE
SLOWEST FOLLOWED BY SREF. THE GFS/ECMWF/CANADIAN ARE THE FASTEST.
ROUGHLY IT LOOKS LIKE THE FRONT IS THROUGH THE NORTHWEST HALF OF
THE AREA BY LATE MORNING. THE FRONT THEN LOOKS TO MOVE ACROSS THE
REST OF THE AREA BY LATE AFTERNOON OR EARLY EVENING.
THE CHANCE OF THUNDERSTORMS WILL BE OVER THE SOUTHEAST PORTION OF
THE AREA IN ADVANCE OF THIS FRONT. CONTINUED THE LOW CHANCE POPS IN
THIS AREA. FRONT AND ASSOCIATED FORCING EXIT THE AREA EARLY IN
THE EVENING AND SO PRECIPITATION CUTS OFF RATHER FAST.
WINDS BEHIND THE FRONT COULD GET WINDY AND THE DAY SHIFT WILL NEED
TO LOOK AT RAISING THE WINDS EVEN MORE. DESPITE SIMILAR TIMING TO
YESTERDAYS OUTPUT...MODELS HAVE RAISED HIGH TEMPERATURES FOR THE
DAY. THE GFS...CANADIAN AND THE NAM ARE IN DECENT AGREEMENT ON
THIS. IT SEEMS THAT THE COLDER AIR DOES LAG SLIGHTLY BEHIND THE
FRONT. DID RAISE MAXES A LITTLE BUT THEY MAY NEED TO BE RAISED
EVEN MORE IN SOUTHERN LOCATIONS.
WINDS STAY UP ENOUGH TONIGHT THAT TEMPERATURES SHOULD NOT DROP
LIKE A ROCK. IF THE WINDS LET UP QUICKER...GOOD RADIATIONAL
CONDITIONS WOULD BE IN PLACE AND A LOWERING OF THE MINS WOULD BE
NEEDED.
SUNDAY/SUNDAY NIGHT...DRY PERIOD WITH POST FRONTAL COOL AIR MASS IN
PLACE. NEW GUIDANCE FOR TEMPERATURES VERY SIMILAR TO WHAT WAS IN
THERE FOR MAXES AND MADE ONLY SLIGHT ADJUSTMENTS. ONCE AGAIN FOR THE
MINS...IF WINDS END UP BEING LESS THAN CURRENTLY PREDICTED ADDITIONAL
COOLING WILL BE NEEDED.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 330 AM MDT FRI AUG 21 2015
THE EXTENDED PERIOD LOOKS TO BE MOSTLY DRY ALONG WITH NEAR TO ABOVE
NORMAL TEMPERATURES FOR THE AREA AS RIDGING INFLUENCES THE FORECAST.
ON MONDAY...AN UPPER LEVEL RIDGE CONTINUES TO BUILD INTO THE PLAINS
FOLLOWING THE SYSTEM PREDICTED TO IMPACT THE REGION THIS WEEKEND.
THE RIDGE AMPLIFIES AND MOVES EAST EARLY NEXT WEEK...WITH ITS AXIS
NEARING THE PLAINS ON WEDNESDAY. DRY CONDITIONS ARE EXPECTED DURING
THIS TIME FRAME.
MOISTURE RETURNS TO THE AREA WEDNESDAY AND THURSDAY AS A SHORTWAVE
MOVES ALONG THE PERSISTENT RIDGE. THIS DISTURBANCE LOOKS TO GENERATE
SHOWER AND THUNDERSTORM CHANCES WEDNESDAY NIGHT AND THURSDAY FOR
PORTIONS OF THE REGION.
AFTER SUNDAYS COOL DOWN...TEMPERATURES ARE EXPECTED TO QUICKLY
REBOUND IN THE EXTENDED PERIOD WITH HIGHS IN THE UPPER 80S TO LOW
90S AND LOWS IN THE UPPER 50S TO UPPER 60S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1000 PM MDT THU AUG 20 2015
FOR KGLD AND KMCK VFR CONDITIONS EXPECTED. SOUTH WINDS 7-11KTS AT
TAF ISSUANCE EXPECTED TO CONTINUE THROUGH 14Z OR SO BEFORE
INCREASING TO 12KT THRESHOLD AROUND 15Z. GUSTS TO 25KTS OR SO
EXPECTED FROM 17Z THROUGH SUNSET. AFTER SUNSET SUSTAINED SOUTH
WINDS AROUND 13KTS EXPECTED. WILL HAVE TO WATCH A SFC TROUGH/WIND
SHIFT LINE THAT IS FORECAST TO EXTEND FROM NEAR KIML TO KGLD/KITR
AROUND 00Z. CONVERGENCE ALONG THIS BOUNDARY AND AN UNSTABLE
AIRMASS SUGGEST AT LEAST ISOLATED THUNDERSTORMS POSSIBLE. GIVEN
THE LOW THREAT OF DIRECTLY IMPACTING THE TERMINAL (KGLD) WILL
LEAVE OUT OF THE FORECAST FOR NOW.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...JBH
AVIATION...99
AREA FORECAST DISCUSSION
NWS DULUTH MN
1231 AM CDT FRI AUG 21 2015
.UPDATE...
ISSUED AT 1228 AM CDT FRI AUG 21 2015
UPDATED AVIATION SECTION BELOW.
UPDATE ISSUED AT 636 PM CDT THU AUG 20 2015
UPDATED AVIATION SECTION BELOW. CLOUD COVER FORECAST IS CURRENTLY
ON TRACK AND EXPECT TO LOSE A LOT OF THE REMAINING CLOUD COVER
BETWEEN NOW AND 02Z...SETTING US UP FOR A FAIRLY GOOD RADIATIONAL
COOLING NIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 330 PM CDT THU AUG 20 2015
SHOWERS/DRIZZLE ENDING ACROSS THE ARROWHEAD EARLY THIS AFTERNOON
GIVING WAY TO SUNNY AND JUST BELOW SEASONABLE TEMPERATURES ACROSS
THE REGION. CLEAR SKIES AND NEAR-CALM WIND TONIGHT WITH A HIGH
PRESSURE BUILDING IN WILL LEAD TO COOL OVERNIGHT LOWS. SUNNY
AND WARMER ON FRIDAY WITH HIGHS NEAR 80.
ON THE SYNOPTIC SCALE THE BROAD LOW PRESSURE SYSTEM THAT BROUGHT
INTENSE RAINFALL TO THE REGION EARLIER THIS WEEK IS FINALLY
DEPARTING TO THE NORTHEAST. BEHIND THIS SOME LOW-LEVEL RIDGING WILL
BUILD IN TO THE UPPER MIDWEST AS A HIGH PRESSURE BUILDS FROM THE
TENNESSEE TO OHIO RIVER VALLEY. WARM AIR ADVECTION WILL RAMP UP DUE
TO WEST/SOUTHWESTERLY WINDS AT LOW LEVELS TONIGHT INTO TOMORROW. IN
ADDITION...A WEAK WARM FRONT ON THE LEADING EDGE OF THE WARM AIR
ADVECTION WILL MOVE ACROSS MANITOBA INTO NORTHWEST ONTARIO...WHICH
MAY GRAZE THE BORDERLAND WITH SOME SHOWERS OVERNIGHT. WHILE THERE IS
NOT MUCH SUPPORT FROM THE GLOBAL MODEL SUITE AS FAR AS QPF
GOES...MOST MODELS INDICATE THE NECESSARY FORCING WILL BE THERE FOR
A FEW SHOWERS. THE LATEST HRRR RUNS ARE ALSO SUPPORTIVE OF THIS
IDEA...SO INCLUDED SOME LOW POPS UP ALONG THE INTERNATIONAL FALLS
REGION. ON FRIDAY THE LOW-LEVEL RIDGING FLATTENS OUT WITH WEST-
SOUTHWEST FLOW ALOFT RESULTING IN CONTINUED WARM AIR ADVECTION. FOR
REFERENCE...THE 850MB TEMP FROM THIS MORNINGS 12Z SOUNDING AT
INTERNATIONAL FALLS WAS 3.1C...AND THE MODEL CONSENSUS IS FOR THIS
TO RISE TO ABOUT 18C BY FRIDAY AFTERNOON.
TONIGHT...GRADUALLY CLEARING SKIES WITH PATCHY FOG POSSIBLE. WINDS
BECOMING NEAR-CALM IN THE EVENING WHICH SHOULD ALLOW FOR FOG TO
DEVELOP...ESPECIALLY IN NORTHWEST WISCONSIN WHERE THE HEAVIEST
RAINFALL HAS FALLEN OVER THE PAST FEW DAYS. GUIDANCE NOT VERY
SUPPORTIVE OF THE FOG IDEA WHICH IS PROBABLY DUE TO THE DRIER AIR
MOVING IN FROM THE WEST...BUT WITH A WEAK RIDGE OVER THE REGION
TEMPS WILL FALL RAPIDLY AND AT LEAST PATCHY RADIATION FOG SHOULD
DEVELOP. LATER IN THE NIGHT...AFTER MIDNIGHT...SOME HIGH CLOUDS MAY
MOVE IN ACROSS FAR NORTH-CENTRAL MINNESOTA...AND POSSIBLY A SHOWER
OR TWO IN THE INTERNATIONAL FALLS REGION. FOG MAY DISSIPATE BEFORE
SUNRISE IF WINDS PICK UP BY EARLY FRIDAY MORNING...THIS WILL DEPEND
ON THE TIMING OF THE RIDGE AXIS BUT THINKING BY SUNRISE FOG SHOULD
BE GONE EVERYWHERE EXCEPT FOR NORTHERN WISCONSIN NEAR THE UP. LOWS
IN THE LOW/MID 40S TO LOW 50S.
FRIDAY...MOSTLY SUNNY...WARM...AND BREEZY. WINDS OUT OF THE SOUTH AT
10 TO 15 MPH WITH GUSTS TO NEAR 25 MPH. THERE MAY BE AN ISOLATED
SHOWER IN THE MORNING ACROSS THE BORDERLAND...BUT OTHERWISE DRY.
HIGHS IN THE UPPER 70S TO LOW 80S.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 330 PM CDT THU AUG 20 2015
THE MAIN CONCERN FOR THE EXTENDED IS THE THREAT FOR SEVERE WEATHER
SATURDAY AFTERNOON AND NIGHT.
THE SOUTHERLY FLOW CONTINUES ACROSS THE FORECAST AREA FRIDAY NIGHT
OUT AHEAD OF THE SYSTEM. THE NAM AND ECMWF ARE SIMILAR WITH TAKING
THE CENTER ACROSS NORTHERN MN WITH THE GFS KEEPING NORTH OF THE
INTERNATIONAL BORDER. BASED ON CURRENT TRENDS AND PERFORMANCE OF
THE MODELS WITH THE LAST STORM...WILL GO WITH A MIXTURE OF NAM/ECMWF
FOR SOLUTION. THE COLD FRONT WILL ENTER WESTERN LATE SATURDAY
MORNING AND ACROSS THE TWIN PORTS LATE SATURDAY EVENING.
THUNDERSTORMS WILL DEVELOP SATURDAY MORNING IN WRN MN AND MOVE EAST
DURING THE DAY. SPC DAY 3 OUTLOOK INDICATES A SLIGHT RISK MAINLY
EAST OF HIGHWAY 53/I-35 IN MN WITH MARGINAL RISK ACROSS MOST OF THE
REST OF THE FORECAST AREA. AS INDICATED BY THE MID SHIFT...THERE
WILL BE A RISK FOR SEVERE THUNDERSTORMS IN THE AFTERNOON BUT MAY BE
FOCUSED FURTHER WEST IN MN. IT STILL LOOKS LIKE A MCS MAY DEVELOP
LATER IN THE AFTERNOON. IT WILL BE ANOTHER HEAVY RAIN EVENT WITH
PWATS IN THE 1.5 TO 2.0 INCHES EXPECTED ACROSS THE FORECAST AREA.
STORM TOTAL QPF FORECAST IS FOR 1-1.5 INCHES FROM INL TO BRD WITH
0.50 TO 0.75 INCHES FURTHER EAST BY SUNDAY MORNING.
SIMILAR TO THE PAST SYSTEM...MUCH COOLER AIR WILL PUSH INTO THE
REGION WITH SOME SHOWERS ON SUNDAY. HIGHS WILL BE IN THE 60S INTO
THE MIDDLE OF THE WEEK WITH 45-55 AT NIGHT. A SHORTWAVE WILL PASS
THROUGH THE REGION ON THURSDAY BRINGING A POSSIBILITY OF A
THUNDERSTORM.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1228 AM CDT FRI AUG 21 2015
SURFACE RIDGE OF HIGH PRESSURE SLIDING EAST ACROSS THE AREA
OVERNIGHT...WITH SOUTHWEST RETURN FLOW SETTING UP FOR TOMORROW.
MAINLY VFR CONDITIONS AT THIS TIME WITH LIGHT AND VARIABLE WINDS.
FOG HAS ALREADY DEVELOPED AT KHIB...AND EXPECT THIS TO SPREAD TO
ALL TERMINALS IN THE NEXT FEW HOURS. I EXPECT KHYR...KDLH AND KHIB
TO BE AFFECTED WITH IFR CONDITIONS AND CEILINGS THROUGH
APPROXIMATELY 12Z...WITH MVFR CONDITIONS AT KINL AND KBRD AS SOUTH
WINDS SHOULD INCREASE THERE AFTER 09Z AND HELP MIX OUT THE FOG.
FOG TO DISSIPATE IN THE 11-14Z TIME RANGE AND RETURN TO VFR
CONDITIONS FOR THE REMAINDER OF THE TAF PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 62 79 55 65 / 20 40 80 30
INL 60 80 53 63 / 20 70 80 60
BRD 64 81 54 65 / 20 70 60 30
HYR 62 81 55 67 / 10 10 70 30
ASX 61 84 57 69 / 10 10 80 30
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
UPDATE...LE
SHORT TERM...JJM
LONG TERM...STEWART
AVIATION...LE
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
150 AM PDT FRI AUG 21 2015
.SYNOPSIS...HAZY CONDITIONS WILL CONTINUE OVER THE NEXT FEW DAYS DUE
TO SMOKE PASSING THROUGH THE AREA FROM CALIFORNIA WILDFIRES. A WEAK
PUSH OF MOISTURE WILL LEAD TO SLIGHT CHANCES FOR THUNDERSTORMS OVER
MAINLY THE HIGHER TERRAIN SOUTH OF INTERSTATE 15 FRIDAY AND
SATURDAY. DEEPER MOISTURE ARRIVES MONDAY AND COULD LINGER THROUGH
MID WEEK WHICH WILL RESULT IN INCREASING COVERAGE OF SHOWERS AND
STORMS. &&
.SHORT TERM...THROUGH MONDAY NIGHT.
CLEAR SKIES DOMINATE THE FORECAST AREA EARLY THIS MORNING BUT THICK
SMOKE CONTINUES TO BE PROBLEMATIC ACROSS THE OWENS VALLEY. I
ANTICIPATE THE SMOKE WILL CONTINUE TO BE PREVAIL ACROSS THE OWENS
VALLEY AGAIN TODAY...ESPECIALLY FROM BISHOP SOUTHWARD TO OLANCHA.
ELSEWHERE...HAZE REMAINS POSSIBLE AS SMOKE FROM CALIFORNIA WILDFIRES
DRIFTS WEST...THROUGH AFTERNOON BREEZY CONDITIONS MAY HELP MIX OUT
THE HAZE AS IT DID THURSDAY...IMPROVING THE AIR QUALITY SOMEWHAT.
THE BIGGEST CONCERN IN THE SHORT TERM PERIOD BESIDES THE SMOKE
REVOLVES AROUND THUNDERSTORM CHANCES. MOISTURE HAS BEEN SEEPING
INTO THE AREA UNDER A SOUTHERLY FLOW IN THE LOWER LEVELS OF THE
ATMOSPHERE. DEWPOINTS EARLY THIS MORNING HAVE REACHED NEAR 60
DEGREES AT BULLHEAD CITY AND NEEDLES...AND MID 60S IN LAKE HAVASU.
FURTHER SOUTH...THE DEWPOINT IN YUMA HAS SHOT UP TO 75F AND VAD WIND
PROFILER DATA INDICATES A SOUTHERLY FLOW OF 15-20KTS IN THE LOWER 4K
FEET OF THE ATMOSPHERE DRIVING THIS DEEPER MOISTURE NORTHWARD. WHILE
MUCH OF THIS MOISTURE WILL MIX OUT WITH DAYTIME HEATING...THERE
SHOULD STILL BE ENOUGH MOISTURE TO KICK OFF SOME ISOLATED CONVECTION
ALONG THE HIGHER TERRAIN OF MOHAVE...EXTREME EASTERN SAN
BERNARDINO...AND SOUTHERN CLARK COUNTIES THIS AFTERNOON AND EVENING.
TROUBLE WILL BE THE LACK OF ANY SUBSTANCIAL TRIGGERING MECHANISM TO
GET THINGS GOING. EARLY MORNING RUNS OF THE HRRR DO NOT PAINT A VERY
PROMISING PICTURE FOR STORMS TODAY AND MOST MODEL GUIDANCE DOESNT
DEVELOP ACTIVITY DESPITE THE INSTABILITY PRESENT. OPTED TO MAINTAIN
THE SLIGHT CHANCE...TERRAIN ORIENTED POPS BUT CONFIDENCE IN
DEVELOPMENT IS NOT REAL HIGH. SIMILAR OUTLOOK FOR SATURDAY WITH
MARGINAL MOISTURE AND INSABILITY PRESENT...BUT NO REAL TRIGGER.
ON SUNDAY...ANY DISCERNIBLE INSTABILITY GETS SHIFTED FURTHER EAST
INTO FAR EASTERN MOHAVE COUNTY...SO KEPT POPS LIMITED TO THOSE FAR
EASTERN ZONES AND CONDITIONS DRY ELSEWHERE. TEMPERATURES FRIDAY
THROUGH THE WEEKEND WILL AVERAGE 3 TO 6 DEGREES ABOVE NORMAL.
ON MONDAY...LEADING EDGE OF DEEPER MONSOON MOISTURE BEGINS TO LIFT
INTO NORTHWEST ARIZONA AND EASTERN CALIFORNIA. BETTER MOISTURE AT
THIS POINT LOOKS TO ARRIVE OVERNIGHT AND INTO TUESDAY BUT SOME
ACTIVITY MAY BREAK OUT IN MOHAVE...EASTERN SAN BERNARDINO...AND THE
HIGHER TERRAIN OF CLARK COUNTIES AND MAINTAINED POPS IN THESE AREAS.
.LONG TERM...TUESDAY THROUGH FRIDAY.
MODELS HAVE COME INTO BETTER LARGE SCALE AGREEMENT FOR MUCH OF THE
PERIOD...BUT IMPORTANT DETAIL DIFFERENCES REMAIN. FOR TUESDAY...THE
GFS LOOKS MUCH LIKE ITS PREVIOUS RUNS...BUT THE ECMWF DEPICTS THE
FOUR CORNERS HIGH CENTER JUST A BIT FARTHER WEST...WHICH DELAYS THE
MOISTURE RETURN AND SENDS HIGH TEMPERATURES ZOOMING BACK UP TO NEAR
EXCESSIVE HEAT CRITERIA. WHILE THIS IS A POSSIBILITY...BELIEVE IT
HAS A LOW PROBABILITY OF OCCURRENCE GIVEN MODEL TRENDS OVER THE PAST
SEVERAL DAYS...AND HAVE GIVEN IT LITTLE WEIGHT IN THE FORECAST. THE
GFS SOLUTION...WHICH SUGGESTS PRECIP CHANCES ROUGHLY NEAR AND EAST
OF LAS VEGAS...WAS PREFERRED. FOR WEDNESDAY AND THURSDAY...MODELS
HAVE COME INTO MUCH BETTER AGREEMENT WITH AMPLIFICATION OF BOTH THE
NORTHERN STREAM LOW NEAR THE BRITISH COLUMBIA COAST AND THE RIDGE
EXTENDING NORTH INTO SASKATCHEWAN FROM THE FOUR CORNERS HIGH. THIS
LEAVES OUR CWA IN MOIST SOUTHERLY FLOW ON WEDNESDAY...TRANSITIONING
INTO A SLIGHTLY DRIER SOUTHWEST FLOW ON THURSDAY AS TROUGHING IN THE
EAST PACIFIC STRETCHES ALL THE WAY DOWN BELOW 30N. THERE IS
DISAGREEMENT ON HOW TO EVOLVE THIS TROUGHING ON FRIDAY...BUT DECENT
CONSENSUS THAT OUR SENSIBLE WEATHER WILL CHANGE LITTLE...WITH
SOUTHWEST FLOW BRINGING MINIMAL PRECIP CHANCES BUT PERHAPS NOT
STRONG ENOUGH TO SCOUR OUT LOW LEVEL MOISTURE...ESPECIALLY OVER
MOHAVE COUNTY.
&&
.AVIATION...FOR MCCARRAN...LIGHT SOUTHERLY DRAINAGE WINDS EXPECTED
EARLY IN THE MORNING BEFORE BECOMING LIGHT AND VARIABLE SUNRISE
THROUGH AROUND 17Z. A PERIOD OF SOUTHEAST WINDS OF 9-12KTS IS
POSSIBLE BETWEEN 17Z AND 20Z BEFORE SOUTH-SOUTHWEST WINDS TAKE OVER
IN THE AFTERNOON WITH GUSTS TO 25KTS. HAZY CONDITIONS REMAIN
POSSIBLE.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...AREAS OF HAZE EXPECTED MAINLY NORTH OF INTERSTATE 40
AGAIN TODAY WITH SMOKE MOST CONCENTRATED NEAR THE SIERRA AND OWENS
VALLEY. SMOKE MAY LOCALLY REDUCE VISIBILITIES TO BELOW 4 MILES.
OTHERWISE...BREEZY SOUTH WINDS OF 12-18 KTS WITH GUSTS TO 25KTS
EXPECTED ACROSS THE AREA IN THE AFTERNOON. SLIGHT CHANCES FOR
ISOLATED THUNDERSTORMS EXIST IN THE HIGHER TERRAIN MAINLY SOUTH AND
EAST OF KLAS THIS AFTERNOON.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
SHORT TERM...OUTLER
LONG TERM...MORGAN
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
352 AM CDT FRI AUG 21 2015
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 345 AM CDT FRI AUG 21 2015
FORECAST CHALLENGES WILL BE SEVERE THREAT SATURDAY AS WELL AS RAINFALL
AMOUNTS MAINLY THIS WEEKEND AND TEMPERATURES/WIND. MODELS OVERALL
IN PRETTY GOOD AGREEMENT THROUGH THE PERIOD AND WILL USE MODEL
BLEND.
CURRENT SHORTWAVE PROPAGATING EAST ACROSS SW MB INTO ONTARIO THIS
MORNING. ASSOCIATED AREA OF SHRA/ISOLD T ON NOSE OF LOW LEVEL JET
IN WARM ADVECTION ZONE. ALTHOUGH INSTABILITY AND CAPE MINIMAL A
FEW LIGHTNING STRIKES OCCURRING. CURRENT HRRR WEAKENS PCPN
THROUGH THE MORNING AND OUT OF THE FA BY MID MORNING. WILL
MAINTAIN LOW POPS BASED ON SHORT TERM MODEL GUIDANCE. THE
REMAINDER OF THIS AFTERNOON SHOULD REMAIN DRY. CONTINUED WARM
ADVECTION WILL SET UP WARM FRONTAL BOUNDARY ALONG THE
INTERNATIONAL BORDER BY THIS EVENING. WITH FA IN WARM SECTOR
TEMPERATURES SHOULD RECOVER WELL WITH MOST AREAS ABOVE AVERAGE.
TONIGHT MORE SIGNIFICANT WAVE CURRENTLY OVER BC WILL DIG INTO THE
NORTHERN ROCKIES. ASSOCIATED SURFACE LOW WILL ORGANIZE OVER THE
WESTERN DAKOTAS WITH SW-NE ORIENTED BOUNDARY SETTING UP LATER IN
THE NIGHT. WILL CONTINUE WITH CHANCE POPS ALONG THIS BOUNDARY.
TEMPERATURES WILL REMAIN MILD OVERNIGHT.
SURFACE LOW WILL LIFT NE SATURDAY AS WAVE APPROACHES. AS IT DOES
ASSOCIATED COLD FRONT WILL FOLLOW LOW AND BE ORIENTED CLOSE TO THE
VALLEY BY PRIME HEATING. CONVECTIVE PARAMETERS FAVORABLE FOR
SEVERE STORMS ALONG AND AHEAD OF THE BOUNDARY SO SEVERE POTENTIAL
WILL HINGE ON JUST WHERE BOUNDARY SETS UP. DEGREE OF CLOUD COVER
WILL GOVERN TEMPERATURES WITH COOLEST READINGS OVER THE FAR NW
WHICH WILL BE BEHIND THE COLD FRONT.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 345 AM CDT FRI AUG 21 2015
UPPER TROUGH CLOSES OFF SATURDAY NIGHT AS IT LIFTS NE. WRAP
AROUND/DEF ZONE RAIN WILL FOLLOW. AT THIS POINT MODEL GUIDANCE
SUGGESTS THAT THE BEST POTENTIAL FOR RAIN WILL BE OVER THE
NORTHERN 2/3RD OF THE FA.
SUNDAY WILL BE WINDY AND COOLER WITH DEF ZONE PCPN BAND SHIFTING
EAST ACROSS THE FA. COOLER COLUMN AND CLOUDS WILL HOLD
TEMPERATURES DOWN.
RAIN WILL MOVE OUT OF THE NE FA SUNDAY NIGHT. WINDS TO DIMINISH
BUT WILL BE A COOL NIGHT WITH MINIMUM TEMPERATURES IN THE 40S.
LONG WAVE TROUGHS WERE OFF THE WESTERN CANADIAN COAST AND THE GREAT
LAKES WITH A FLAT RIDGE OVER MT. PATTERN AMPLIFIES WITH A TROUGH
OVER THE EASTERN PACIFIC/WESTERN CANADA AND RIDGING INTO THE
NORTHERN PLAINS BY THE END OF THE PERIOD.
GFS AND ECMWF WERE IN BETTER AGREEMENT WITH TODAYS MODEL RUN THROUGH
THE PERIOD. THE ECMWF WAS SLIGHTLY FASTER THAN THE GFS. THE ECMWF
WAS VACILLATING AROUND A POINT WHILE THE GFS WAS TRENDING SLOWER
OVER THE LAST COUPLE MODEL RUNS.
NO CHANGE TO HIGH TEMPS FOR MON. HIGH TEMPS WERE DECREASED A DEGREE
OR TWO FOR TUE AND WED, AND INCREASED ZERO TO FOUR DEGREES FOR THU
FORM YESTERDAYS PACKAGE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1149 PM CDT THU AUG 20 2015
SCATTERED MID AND HIGH LEVEL CLOUDS MAINLY NE ND/NW MN WITH SHORT
WAVE MOVING THRU MANITOBA OVERNIGHT INTO FRIDAY MORNING. SCATTERED
CIRRUS IN SE ND/WCNTRL MN. SOUTH WINDS 8 TO 15 KTS WITH A FEW
GUSTS AT TIMES THRU FRIDAY....PICKING UP FRI EVENING.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...VOELKER
LONG TERM...HOPPES/VOELKER
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
146 AM EDT FRI AUG 21 2015
.SYNOPSIS...
A COLD FRONT HAS MOVED EAST OF THE AREA WITH COOLER AND DRIER AIR
SETTLING OVER THE AREA BEHIND IT. A SURFACE AREA OF HIGH PRESSURE
TO OUR WEST WILL MOVE INTO THE AREA FRIDAY AND LINGER THROUGH THE
WEEKEND. THE NEXT CHANCE FOR RAIN WILL BE SUNDAY NIGHT INTO MONDAY
WHEN A COLD FRONT ARRIVES.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
UPPER TROUGH WILL LIFT ACROSS THE CENTRAL GREAT LAKES OVERNIGHT.
THERE WILL BE SOME INCREASED LIFT OVER THE LAKE AS THE COOLER AIR
ARRIVES IN THE WAKE OF THE TROUGH. THERE COULD BE A FEW SHOWERS
THAT DEVELOP FROM THE ERIE AREA NORTHWARD INTO NY STATE. HOWEVER
THE MAIN IMPACT WILL BE AN INCREASE OF CLOUD COVER FROM CLEVELAND
TO ERIE THROUGH THE EVENING.
PREVIOUS DISCUSSION...
THE WATER VAPOR SATELLITE IMAGERY DISTINCTLY DEFINES THE TROUGH
OVER THE UPPER LAKES AND THE DRIER AIR FILTERING INTO THE OHIO
VALLEY ALOFT. AT THE SURFACE HIGH PRESSURE OVER THE PLAINS WILL
SLIDE EAST OVERNIGHT AND LINGER OVER THE AIR INTO THE WEEKEND. DEW
POINTS HAVE DROPPED 10-15F SINCE THIS MORNING...WHICH WILL SUPPORT
NOTABLY COOLER TEMPERATURES OVERNIGHT. NCAR ENSEMBLES ALONG WITH
THE RUC ARE SUGGESTING DEW POINTS INTO THE UPPER 40S
OVERNIGHT...HOWEVER NOT SEEING ANY 40S UPSTREAM OR NEAR THE AREA
DESPITE A FAIR AMOUNT OF AFTERNOON MIXING. WITH DEW POINTS IN THE
LOW TO MID 50S...MOSTLY CLEAR SKIES...AND WINDS TAPERING OFF AFTER
DARK...WILL KEEP TEMPERATURES IN THE LOW TO MID 50S OVERNIGHT.
ONLY FLY IN THE OINTMENT WILL BE ANY POTENTIAL DEVELOPMENT OVER
THE LAKE AS THE H850 AND WATER TEMPERATURES DIFFER BY ABOUT 14C.
THE BEST CHANCE FOR ANYTHING TO DEVELOP WILL BE BETWEEN 06 AND 15Z
FRI...BUT AT THIS TIME WILL KEEP ONLY ISOLATED RAIN OVER THE
EASTERN PORTIONS OF THE LAKE AND NOT INTO ERIE PA.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/...
AS THE HIGH BUILDS OVERHEAD FRIDAY ANY LAKE ACTIVITY WILL BE SHUT
DOWN BY THE DRIER AIR AND THE SINKING INVERSION. LOOK FOR SUNNY
SKIES AND TEMPERATURES IN THE 70S. THE HIGH WILL SHIFT EAST ON
SATURDAY WHICH WILL SUPPORT SOME WEAK RETURN FLOW WHICH WILL
CONTINUE INTO SUNDAY. MEANWHILE THE NW FLOW ALOFT WILL TURN TO
THE SW WITH WARMER TEMPERATURES ADVECTING IN WITH H850 REACHING
12C WHICH WILL TRANSLATE INTO GRADUAL WARMING AT THE SURFACE. THE
NEXT CHANCE FOR PRECIPITATION WILL BE ASSOCIATED WITH ANOTHER MID
LEVEL TROUGH MOVING OUT OF THE ROCKIES. AN ASSOCIATED COLD FRONT
WILL REACH THE AREA SUNDAY NIGHT AND WITH WARMER/MOIST AIR AND AN
INCREASE IN THE LOW LEVEL JET CAN`T RULE OUT SOME THUNDERSTORMS.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
A COLD FRONT WILL BE MOVING THROUGH THE EASTERN EDGE OF THE AREA
MONDAY MORNING ALONG WITH A FEW LINGERING SHOWERS. COLD ADVECTION
WILL OVERSPREAD THE REGION IN THE WAKE OF THE COLD FRONT. THE
UPPER AIR PATTERN WILL EXHIBIT A LONG WAVE TROUGH OVER ONTARIO
EARLY IN THE EXTENDED WITH THIS FEATURE LIFTING FARTHER NORTH AND
ALLOWING A MORE ZONAL FLOW TO DEVELOP. BELOW NORMAL TEMPERATURES
ARE EXPECTED WITH GENERALLY DRY CONDITIONS BUT A FEW SHOWERS ARE
POSSIBLE WEDNESDAY AFTERNOON AND EVENING MAINLY OVER NORTHWEST PA
WHERE A MOIST CYCLONIC FLOW ALOFT ALONG WITH WELL MIXED ADIABATIC
CONDITIONS ARE EXPECTED.
CONDITIONS WILL WARM ON THURSDAY AND FRIDAY AS THE 850 MB
TEMPERATURES RISE TO MORE SEASONAL LEVELS AND MORE SUNSHINE
PREVAILS.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
SYNOPTIC AND LAKE EFFECT CLOUDS PRIMARILY AROUND 6K FEET WILL
PERIODICALLY PASS OVER SITES NEAREST TO THE LAKESHORE. KERI COULD
BRIEFLY SEE A 3.5K FOOT CIG DEVELOP BY DAYBREAK. CLOUDS WILL
BEGIN TO BREAK UP FRIDAY AFTERNOON AS HIGH PRESSURE MOVES IN FROM
THE SW. DIURNAL CU IS THEN LIKELY TO DEVELOP ACROSS NEOH AND NWPA.
THE WIND WILL GRADUALLY DIMINISH THROUGH THE DAY AS THE HIGH
APPROACHES. FRIDAY NIGHT THE WIND WILL BECOME LIGHT AND VARIABLE
IN THE EAST WITH THE HIGH OVERHEAD...AND SOUTHERLY IN THE WEST.
OUTLOOK...NON VFR CONDITIONS POSSIBLE SUNDAY NIGHT WITH THE PASSAGE
OF A COLD FRONT AND POSSIBLE SHOWERS AND THUNDERSTORMS.
&&
.MARINE...
SMALL CRAFT CONDITIONS PREVAIL IN THE WAKE OF THE COLD
FRONT THAT HAS SWEPT EAST THROUGH THE REGION. A RATHER STRONG
PRESSURE GRADIENT FOR SUMMER ALONG WITH COLD ADVECTION ALOFT WILL
ALLOW MIXING OF HIGHER MOMENTUM AIR TO THE SURFACE. WITH 850 MB
TEMPERATURES EXPECTED TO DROP TO NEAR 10C AND LAKE SURFACE
TEMPERATURES FROM 22-24C... NEAR ADIABATIC LAPSE RATE IS EXPECTED
OVER THE LAKE WHICH WILL PERMIT DEEP MIXING AND STRONGER WINDS TO
PREVAIL. WILL CONTINUE WITH SMALL CRAFT ADVISORY THROUGH 08Z EAST
OF THE ISLANDS. IT MAY NEED TO BE EXTENDED SLIGHTLY LONGER IN THE
EASTERN HALF OF THE LAKE WHERE THE STRONGER PRESSURE GRADIENT WILL
LINGER.
HIGH PRESSURE WILL GRADUALLY BUILD SOUTH OF THE LAKE FRIDAY AND THEN
REMAIN OVER THE REGION INTO THE WEEKEND. WINDS WILL CONTINUE TO
DIMINISH FRIDAY AND BE LIGHT ON SATURDAY. SOUTHERLY WINDS WILL
INCREASE ON SUNDAY AS ANOTHER FRONTAL BOUNDARY APPROACHES WITH ITS
PASSAGE EXPECTED SUNDAY NIGHT. SMALL CRAFT CONDITIONS WILL LIKELY
DEVELOP IN THE WAKE OF THAT FRONTAL PASSAGE GIVEN THE COOLING ALOFT
DOWN TO JUST BELOW 10C AT 850 MB. WINDS WILL DECREASE ON TUESDAY AS
HIGH PRESSURE BUILDS INTO THE REGION.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT EARLY THIS MORNING FOR
LEZ144>149.
&&
$$
SYNOPSIS...JAMISON
NEAR TERM...JAMISON/MULLEN
SHORT TERM...JAMISON
LONG TERM...LAPLANTE
AVIATION...MAYERS
MARINE...ADAMS/LAPLANTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
124 AM EDT FRI AUG 21 2015
.SYNOPSIS...
HIGH PRESSURE OVER THE OHIO VALLEY WILL BUILD EAST INTO
PENNSYLVANIA TODAY AND REMAIN OVER THE REGION THROUGH THE UPCOMING
WEEKEND. A COLD FRONT WILL MOVE THROUGH THE AREA ON MONDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
WET GROUND...CLEARING SKIES AND A LIGHT WIND PROMOTING PATCHY
DENSE FOG ACROSS CENTRAL PA EARLY THIS AM. 11-3.9U SATL IMAGERY
SHOWING THE FOG IS MOST PREVALENT ACROSS THE EASTERN HALF OF THE
STATE...WHERE THE HEAVIEST RAIN FELL. NEAR TERM MDL SFC RH FIELDS
IMPLY THIS WILL REMAIN THE CASE THROUGH DAWN.
TEMPS ON TRACK TO BOTTOM OUT FROM THE L50S ACROSS THE NW
MTNS...TO THE L-M 60S IN THE FAR SE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SATURDAY/...
THE FRONT IS EXPECTED TO SLOW AND EVENTUALLY STALL OUT AS IT
NEARS THE MID ATLC COAST...IN RESPONSE TO STRONG N. ATLC UPPER
RIDGE AND UPPER/NON-TROPICAL LOW NEAR BERMUDA. THERE IS SOME
CONCERN THAT THE EASTERN MOST PORTIONS OF OUR FORECAST ZONES
COULD SEE LINGERING CLOUDS AND A SHOWER....BUT I USED THE HRRR TO
DOWNPLAY THIS SCENARIO AS LOW PW AIR MOVES IN.
SKIES SHOULD BECOME MOSTLY SUNNY ACROSS CENTRAL AND SOUTHERN
PENN...WHILE PERIODS OF BKN-OVC STRATO CU WILL LIKELY FORM ACROSS
THE NRN MTNS OF PENN WITH EVEN A FEW SPRINKLES POSSIBLE.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
A RELATIVELY QUIET STRETCH OF WEATHER IS IN STORE THROUGH THIS
WEEKEND AND MUCH OF NEXT WEEK. PWATS WILL DROP TO -1SD FRI AND
REMAIN THAT WAY THRU THE WEEKEND...WHICH WILL BE A NICE CHANGE FROM
THE MUGGY AIRMASS WE SAW MUCH OF THE PAST WEEK.
IN ALL...THE WEEKEND LOOKS PLEASANT WITH LOW HUMIDITY AND
TEMPERATURES RUNNING A FEW DEGREES BELOW LATE-AUGUST NORMALS. THE
ONLY POTENTIAL FLY IN THE OINTMENT IS A WEAK AREA OF LOW PRESSURE
OFF THE MID-ATLANTIC COAST THAT COULD TRY TO PUSH A BIT OF
CLOUDINESS WESTWARD INTO EASTERN PA ON SUNDAY.
A WEAKENING COLD FRONT WILL CROSS THE COMMONWEALTH ON
MONDAY...ACCOMPANIED BY AN OUTSIDE CHC FOR A FEW SHRA/TSRA.
BEHIND THE FRONT...THE MIDDLE OF NEXT WEEK SHOULD SEE A RETURN TO
LOW HUMIDITY AND SLIGHTLY BELOW NORMAL TEMPS.
&&
.AVIATION /05Z FRIDAY THROUGH TUESDAY/...
GIVEN THE COPIOUS AMOUNTS OF WIDESPREAD PRECIPITATION THIS
AFTERNOON AND EVENING AND THE CLEARING SKIES AND WEAK FLOW EXPECT
FOR LOW STRATOCU AND PATCHY DENSE FOG TO DEVELOP OVERNIGHT. IN THE
11U-3.9U THERE IS A LINE OF DRY AIR MOVING IN WHICH WILL LIMIT AND
PREVENT FOG/LOW STRATOCU DEVELOPMENT. IPT HAS DECOUPLED WITH LIFR
CIGS AND VSBYS. GIVEN THE WESTERLY FLOW EXPECT WESTERN AND CENTRAL
TAF SITES TO HAVE PERIODS OF IFR FROM 06Z TO 13Z WITH MVFR TO
POSSIBLY VFR IN THE INTERIM. AS THE REGION MIXES OUT AFTER
SUNRISE AND DRY AIR MIXES DOWN ANY AREAS OF 1/2SM VSBY FOG WILL
TEND TO MVFR BETWEEN 12Z TO 15Z BEFORE BECOMING VFR ACROSS ALL OF
CENTRAL AND SOUTHERN PENN.
OUTLOOK...
SAT-MON...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD/LA CORTE
NEAR TERM...FITZGERALD
SHORT TERM...LAMBERT/STEINBUGL
LONG TERM...EVANEGO
AVIATION...LAMBERT/CERU
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
333 AM CDT FRI AUG 21 2015
.SHORT TERM (TODAY THROUGH SATURDAY)...
A N-S ORIENTED SHEAR AXIS MOST NOTABLE IN THE MID LEVELS OVER S TX
AND ADJACENT AREAS OF NERN MEXICO SHOULD BRING ANOTHER DAY OF
CONVECTION AND MODERATED DAYTIME TEMPERATURES FOR THE EASTERN
HALF OF SOUTH CENTRAL TX. WHILE THE FRONTAL ZONE THAT BROUGHT WELL
BELOW NORMAL MAX TEMPS TO THE AREA THURSDAY HAS RETREATED
NORTH...SOME COASTAL TROUGHING IS STILL NOTED NEAR CRP...AND A
SMALL COMPLEX OF STORMS CONFIRMS THE UNSTABLE ENVIRONMENT THAT
COULD SPREAD INLAND LATER THIS MORNING. RAPID REFRESH MODEL RUNS
DEPICT EARLY DESTABILIZATION NEAR AND EAST OF I-35 TODAY...BUT
EARLIER RUNS OF THE HRRR WERE SHOWN TO BE TOO AGGRESSIVE WITH
CONVECTION IN THE PRE-DAWN HOURS. ADDITIONAL MOISTURE AND POSSIBLE
INSTABILITY IS MOVING IN FROM NW FLOW ALOFT FROM WEST TX...BUT
WITH ONLY THE 00Z NSSL WRF MODEL SHOWING AN IMPACT OVER OUR
WESTERN COUNTIES VERSUS SEVERAL THAT DO NOT...WILL STICK WITH THE
CONSENSUS POPS FOR THE SERN TWO-THIRDS OF THE FORECAST AREA.
BLENDED GUIDANCES CONTAIN ARTIFACTS OF EARLIER FORECAST HIGHER
TEMPS...SO OPTED FOR A BLEND OF MAV/MET FOR HIGHS.
MODEL RUN TO RUN TRENDS IN THE EARLY PERIODS SHOW MORE SHEAR THAN
EARLIER RUNS...SO WILL FOLLOW THIS TREND TO KEEP A SLIGHTLY LESS
STABLE PICTURE FOR OUR SOUTHERN/WRN COUNTIES FOR SATURDAY.
INCREASED RIDGING AND DRY AIR ENTRAINMENT FROM THE NORTH SHOULD
PRECLUDE CONVECTION OVER MOST OF SOUTH CENTRAL TEXAS...BUT THE
WESTWARD SHIFTING SHEAR AXIS SHOULD PULL SOME MOISTURE WITH IT TO
BRING A SLIGHT CHANCE OF DAYTIME CONVECTION OVER THE RIO GRANDE
PLAINS. MEANWHILE SOUTHERN PARTS OF THE COASTAL PLAINS LOSE THE
CYCLONIC SHEAR BUT MAINTAIN LOCALLY HIGHER PWAT VALUES FOR ONE
MORE DAY. WILL FAVOR THE GFS BASED GUIDANCE FOR WARMER TEMPS TO
REGAIN CONTROL OVER CENTRAL TX WHERE THE DRIER AND MORE STABLE MID-
LEVEL AIR MOVES IN.
&&
.LONG TERM (SATURDAY NIGHT THROUGH THURSDAY)...
THE BRIEF BREAK FROM THE HEAT IS ALL BUT FORGOTTEN BY SUNDAY. THE
GFS AND ECMWF BOTH BUILD A STRONG RIDGE OVER THE SOUTHERN ROCKIES
WITH AN AXIS THAT EXTENDS SE ACROSS CENTRAL TX. WILL SHADE TOWARD
THE HIGHER MEX GUIDANCE ON MAXES SUNDAY THROUGH WEDNESDAY AS
AUGUST RAINS HAVE BEEN MOSTLY TOO SPARSE TO PROVIDE FEEDBACK
THROUGH SOIL AND VEGETATION. LATE MONDAY THROUGH DAYTIME
WEDNESDAY...THERE IS A SIGNAL FOR MID-LEVEL MOISTURE POOLING TO
SPREAD SOUTH FROM NORTH TX AS NORTHERLY FLOW INCREASES ALOFT. THUS
WILL SHADE TOWARD THE SLIGHTLY MORE UNSTABLE ECMWF OVER THE
SLIGHTLY DRIER GFS FOR THOSE DAYS. LITTLE OR NO CONVECTION IS
SHOWN BY EITHER MODEL FOR THE REMAINDER OF NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 94 76 98 77 99 / 20 10 10 - -
AUSTIN BERGSTROM INTL AIRPORT 93 73 97 75 98 / 30 10 10 - -
NEW BRAUNFELS MUNI AIRPORT 94 75 98 76 98 / 30 10 10 - -
BURNET MUNI AIRPORT 93 74 97 75 98 / 10 10 10 - -
DEL RIO INTL AIRPORT 96 76 98 78 99 / 10 - 20 - -
GEORGETOWN MUNI AIRPORT 92 76 96 76 98 / 20 10 10 - 10
HONDO MUNI AIRPORT 95 74 96 75 97 / 20 10 10 - -
SAN MARCOS MUNI AIRPORT 93 75 98 76 99 / 30 10 10 - -
LA GRANGE - FAYETTE REGIONAL 93 76 96 76 98 / 40 20 20 10 10
SAN ANTONIO INTL AIRPORT 93 76 97 77 98 / 30 10 10 - -
STINSON MUNI AIRPORT 94 76 98 77 99 / 30 20 10 - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...ALLEN
SYNOPTIC/GRIDS...OAKS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
318 AM CDT FRI AUG 21 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 318 AM CDT FRI AUG 21 2015
MOST OF THE FORECAST TIME THIS MORNING WAS ENSURING WE WERE ON TRACK
WITH RAIN CHANCES IN THE RETURN FLOW TODAY....CLOUDS ON
SATURDAY...BUT MAINLY THE SATURDAY NIGHT THUNDERSTORM THREATS AND
ANY MESSAGING THAT WILL BE NEEDED FOR THOSE OUTDOORS.
CURRENT OBSERVATIONAL DATA AS OF 21.07Z INDICATES NW-SE ORIENTED
CLOUD BANDING AROUND 10KFT ACROSS CENTRAL MN ASSOCIATED WITH
FRONTOGENESIS IN THE 800-900 MB LAYER PER LATEST RAP ANALYSIS.
TSRA AND LIGHTNING IN NWRN IA ON THE NOSE OF THE LOW-LEVEL JET PER
88D VWPS AND RAP ANALYSIS. SPC MESOANALYSIS SHOWING THAT TSRA IS
ON THE NORTHERN EXTENT OF THE MUCAPE REGION /ONLY ABOUT 250 J/KG
THERE/.
GOES FOG PRODUCT AND SURFACE OBSERVATIONS SHOW A LOWER CLOUD FIELD
OVER OK/TX SOUTH IN A RICH MOIST POOL OF SURFACE DEWPOINTS OVER
65F...AND 925MB DEWPOINTS AT 18C PER 21.00Z RAOBS. WILL HAVE TO
WATCH THIS AREA AS IT ADVECTS NORTHWARD AHEAD OF THE FRONT THAT IS
MOVING IN FOR SATURDAY NIGHT...ASSOCIATED WITH THE SHORTWAVE
TROUGH NOW WORKING SOUTHWARD THROUGH BRITISH COLUMBIA /PER GOES
WATER VAPOR/. RAP ANALYSIS INDICATES THIS SPINNER HAS A TROPOPAUSE
FOLD DOWN TO ROUGHLY 750 MB...SO A POTENT VORTEX.
SHORT TERM GUIDANCE SUPPORTS EVOLVING THE FRONTOGENESIS AND THE
LOW-LEVEL JET NOSE CONVERGENCE NORTHEAST THROUGH THE FIRST PORTION
OF TODAY INTO NRN WI BY AFTERNOON. THERE WILL LIKELY BE VERY LIGHT
RADAR RETURNS AND PER 00Z RAOB DATA...SOME PRETTY DRY AIR TO
OVERCOME BELOW THE ACCAS CLOUD BASE /10KFT/. FOR NOW...HAVE KEPT
THE HIGHER PROBABILITY DRY FORECAST. SPRINKLES OR AN ISOLATED
WETTING SHOWER MAY BE POSSIBLE WITH FORCING EVOLUTION NEWRD.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 318 AM CDT FRI AUG 21 2015
NO BIG CHANGES DURING THIS PERIOD.
SOUTHWESTERLY FLOW WILL PREVAIL SATURDAY AND PRE-FRONTALLY WILL
NEED TO WATCH THE SURGE OF 925 MB MOISTURE NORTHWARD TONIGHT.
CONSENSUS 21.00Z GUIDANCE SUGGESTS THIS TONGUE REMAINS WEST OF THE
AREA UNTIL FRONT ARRIVES SAT EVENING. HAVE INCREASED WIND GUSTS
SATURDAY WITH STRONGER LOW-LEVEL WIND FIELD SUGGESTED AND MIXING
DEPTH INTO THE 35-38KT CONSENSUS 900MB WINDS.
TIMING IS ABOUT THE SAME AS PREVIOUS FORECASTS FOR FRONT TO
BECOME ACTIVE TO THE WEST OF THE AREA LATER SATURDAY. THIS FRONT
IS ASSOCIATED WITH THE BRITISH COLUMBIA SHORTWAVE AS IT DIGS
SOUTHEAST INTO CENTRAL MN...THEN EJECTS NORTHEAST OVER DULUTH.
THUS...THE AREA ISNT DIRECTLY HIT BY THE MID-UPPER TROPOSPHERIC
FORCING...WHICH FAVORS BETTER CONVECTION TO EJECT NORTHEAST...BUT
BROAD ASCENT FROM LARGE SCALE FORCING IS OVER THE AREA. THE CAPE
AXIS IS VERY NARROW...RIGHT ALONG THE FRONT...WITH A STOUT CAP OUT
AHEAD SUGGESTED. MUCAPE HAS REMARKABLE DROP SUGGESTED IN THE
MODEL GUIDANCE FROM 7PM TO 1 AM...ABOUT 2500 IN PEAK HEATING WEST
OF THE FORECAST AREA...TO ABOUT 750 J/KG BY 1 AM ON THE MISS
RIVER. THE WESTERN FORECAST AREAS OF NERN IA AND SERN MN HAVE THE
MOST POTENTIAL FOR SEVERE STORMS FOR A SMALL WINDOW SATURDAY
EVENING AS THE STORMS WEAKEN HEADING EAST. SPC DAY 2 RISK HAS
SHIFTED THE SLIGHT RISK EAST INTO THAT AREA...BUT NOT TOO MUCH HAS
CHANGED. MODEST 0-3KM WIND SHEAR WOULD FAVOR LINE SEGMENTS
PROMOTING DAMAGING WINDS. THE 0-3KM SHEAR VECTOR IS ALIGNED
PERPENDICULAR TO THE FRONT OR CONVECTIVE LINE...PROMOTING BETTER
COLD POOL MAINTENANCE.
SEVERE THREAT DEPENDS ON TIMING OF THE FRONT AND STORMS. ARRIVAL
IN THE EARLY EVENING WOULD FAVOR HIGHER SEVERE STORM CHANCES PER
HIGHER CAPE IN MODEST LOW-LEVEL SHEAR. CONSENSUS MODEL GUIDANCE IS
A MID-LATER EVENING APPROACH OF STORMS IN NERN IA AND SERN MN
WITH STORMS JUST PAST PEAK AND INTO WEAKENING STAGE...WITH COLD
POOLS THAT COULD PROBABLY PRODUCE ISOLATED WIND DAMAGE. WILL TAKE
A SLIGHT STEP UP IN MESSAGING MOVING TO STRONG TO ISOLATED SEVERE
STORMS.
A COOL FIRST HALF OF THE WEEK IN NORTHWEST FLOW WITH DRIER
CONDITIONS AND BELOW NORMAL TEMPERATURES...WARMING LATE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1128 PM CDT THU AUG 20 2015
VFR CONDITIONS EXPECTED.
AS SURFACE RIDGE QUICKLY PASSES TONIGHT...ALREADY SEEING RESPONSE OF
APPROACHING SHORT WAVE TROUGH COMING THROUGH CENTRAL PLAINS. LOW
LEVEL JET ACROSS WESTERN IOWA INTO MINNESOTA IS HELPING WITH
FRONTOGENETIC BAND SETTING UP IN THE FORM OF MID LEVEL CLOUDS THAT
HAVE FORMED ACROSS MINNESOTA LAST FEW HOURS. LOW LEVEL MOISTURE
TRANSPORT HAS ALSO LED TO SOME CLOUDS AND ISOLATED SHOWERS FURTHER
WEST. GIVEN SUCH DRY AIRMASS AND ONLY MODEST LIFT WITH WAVE...
WILL NOT INTRODUCE ANY RAIN.
THIS FOCUS AREA SHIFTS EAST OF THE AREA AFTER DAYBREAK FRIDAY...SO
OUTSIDE OF A FEW DAYTIME CUMULUS CLOUDS THAT COULD FORM...LOOKING AT
A TRANQUIL AVIATION PERIOD.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...SHEA
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
502 AM MST FRI AUG 21 2015
.UPDATE...TO AVIATION AND FIRE WEATHER DISCUSSIONS...
&&
.SYNOPSIS...
THUNDERSTORMS WILL GENERALLY REMAIN CONFINED TO THE HIGHER TERRAIN OF
SOUTHERN AND EASTERN ARIZONA THROUGH THE WEEKEND. THE MONSOON HIGH
WILL SETTLE ACROSS THE FOUR CORNERS MONDAY...RESULTING IN BETTER RAIN
CHANCES ACROSS THE LOWER DESERTS. DRIER CONDITIONS WILL RETURN BY
MIDWEEK ALONG WITH NEAR TO ABOVE NORMAL TEMPERATURES.
&&
.DISCUSSION...
AN ANTICYCLONE IN THE MID AND UPPER LEVELS REMAINS POSITIONED OFF
THE BAJA PENINSULA...RESULTING IN A WESTERLY COMPONENT TO THE FLOW.
AT THE SURFACE...YUMA VWP SUGGESTS THAT A SHALLOW GULF SURGE IS
TAKING PLACE ACROSS SOUTHWESTERN AZ. DEWPOINTS NEAR YUMA AND ACROSS
THE IMPERIAL VALLEY HAVE RESPONDED...INCREASING INTO THE MID TO UPPER
70S EARLY THIS MORNING. FURTHER EAST ACROSS THE LOWER DESERTS OF
SOUTH-CENTRAL AZ...AN INFLUX OF MOISTURE IS ALSO ANTICIPATED THIS
MORNING...BUT TO A LESSER DEGREE.
SOME EARLIER WRF-BASED GUIDANCE INDICATED THAT SHOWERS AND
THUNDERSTORMS WOULD DEVELOP THIS MORNING ACROSS PORTIONS OF THE
LOWER DESERTS. HOWEVER...THE LATEST LOCAL WRFS AND U OF ARIZONA WRFS
HAVE BACKED OFF CONSIDERABLY AND DEPICT CONVECTION BEING MOST
CONCENTRATED ACROSS THE HIGHER TERRAIN SOUTH AND EAST OF PHOENIX THIS
AFTERNOON. SEVERAL RUNS OF THE HRRR HAVE ALSO DISMISSED THE
POSSIBILITY OF CONVECTION STARTING EARLY THIS MORNING...THOUGH CAPES
ABOVE 1000 J/KG SHOULD CERTAINLY SUPPORT DEVELOPMENT BY EARLY
AFTERNOON. LACK OF A TRIGGER IN THE UPPER LEVELS ALONG WITH WEAK
WESTERLY FLOW POINT TO TERRAIN- BASED CONVERGENCE AS THE PRIMARY
LIFTING MECHANISM. NEVERTHELESS...THERE IS A SLIGHT CHANCE OF
THUNDERSTORMS IN THE PHOENIX AREA...THOUGH THE GREATER LIKELIHOOD IS
FOR AREAS OF BLOWING DUST.
MEAN FLOW WILL BECOME MORE WESTERLY SATURDAY AS THE ANTICYCLONE
DRIFTS NORTHWARD. THIS WILL AGAIN CONFINE THUNDERSTORMS MAINLY TO THE
HIGHER TERRAIN EAST OF PHOENIX. MORE OF THE SAME FOR SUNDAY AS THE
HIGH DRIFTS OVERHEAD.
CONDITIONS WILL BECOME SOMEWHAT MORE FAVORABLE FOR PRECIPITATION
EARLY NEXT WEEK AS THE MONSOON HIGH BECOMES REESTABLISHED ACROSS THE
FOUR CORNERS. INCREASING EASTERLY COMPONENT TO THE FLOW GENERALLY
FAVORS HIGHER CHANCES OF THUNDERSTORMS. HOWEVER...MODEL CROSS
SECTIONS INDICATE THAT ABUNDANT MOISTURE IN THE MID AND UPPER LEVELS
MAY RESULT IN CONSIDERABLE CLOUDINESS AND ULTIMATELY A DECREASE IN
INSTABILITY AND THE POTENTIAL FOR THUNDERSTORMS ACROSS THE AREA.
OPERATIONAL GFS AND ECMWF ALSO SUGGEST THE PRESENCE OF AN INVERTED
TROUGH ACROSS NORTHERN SONORA...THOUGH DIFFERENCES IN THE STRENGTH
AND TIMING OF THIS FEATURE ARE APPARENT.
GENERAL CONSENSUS AMONG THE MODELS FOR NEXT WEEK IS THAT THE MONSOON
HIGH WILL DRIFT EASTWARD AND SOUTHWARD. FLOW WILL GRADUALLY BECOME
SOUTHWESTERLY AGAIN...FAVORING THE HIGHER TERRAIN FOR CONVECTION.
TEMPERATURES AT OR ABOVE NORMAL ARE EXPECTED THROUGH THE EXTENDED.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL AND
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
EARLY AM SCT-BKN CLOUDS BETWEEN PHX AND CGZ WILL SETTLE OUT TO FEW-
SCT MID-LEVEL CLOUDS FOR THE AFTN...WITH SKIES REMAINING MOSTLY
CLEAR FOR THE WESTERN TERMINALS OF BLH AND IPL. S-SE AM WINDS TO
PREVAIL FOR THE TERMINALS SAVE FOR KPHX...WHICH WILL MAINTAIN SUBTLE
W-NW HEADINGS WITH PERIODS OF VRB. AFTN WINDS TO BECOME S-SW FOR THE
PHX AREA TERMINALS...WITH PERIODS OF 20KT GUSTINESS. ISO TS SHOULD
FORM WELL EAST AND SOUTH OF THE PHX AREA...WITH VERY REMOTE CHANCES
OF OUTFLOW RELATED IMPACTS INTO KIWA DURING THE EVENING.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
MONSOON MOISTURE LEVELS AND HUMIDITIES WILL PERSIST THROUGH MIDWEEK.
STORM CHANCES WILL CONTINUE FOR THE HIGHER TERRAIN LOCALES FOR
SUNDAY BEFORE EXPANDING INTO THE LOWER DESERT ELEVATIONS BY THE
EARLY WORK WEEK AS SOME UPPER LEVEL DISTURBANCES PASS THROUGH THE
AREA AND SUPPORT THE POTENTIAL FOR MORE WIDESPREAD STORM
DEVELOPMENT. DAYTIME HUMIDITIES WILL RANGE FROM THE 20 TO 30 PERCENT
RANGE WHILE MAKING GOOD OVERNIGHT RECOVERIES. OUTSIDE OF
THUNDERSTORM OUTFLOW AND VICINITY WINDS...SFC WINDS TO MAINTAIN
DAYTIME HEADINGS 10 TO 20 MPH WHILE BECOMING DOWN DRAINAGE/DOWN
VALLEY IN THE OVERNIGHTS. A SLIGHT DRAW DOWN OF MONSOON MOISTURE AND
INTRUSION OF WESTERLY FLOW ALOFT WILL RELEGATE STORM CHANCES BACK
ACROSS EASTERN AZ FOR THE LATTER PART OF THE WEEK...WHILE
TEMPERATURES ALSO BEGIN TO WARM TO ABOVE NORMAL VALUES.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
AVIATION...NOLTE
FIRE WEATHER...NOLTE
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
328 AM MST FRI AUG 21 2015
.SYNOPSIS...
THUNDERSTORMS WILL GENERALLY REMAIN CONFINED TO THE HIGHER TERRAIN OF
SOUTHERN AND EASTERN ARIZONA THROUGH THE WEEKEND. THE MONSOON HIGH
WILL SETTLE ACROSS THE FOUR CORNERS MONDAY...RESULTING IN BETTER RAIN
CHANCES ACROSS THE LOWER DESERTS. DRIER CONDITIONS WILL RETURN BY
MIDWEEK ALONG WITH NEAR TO ABOVE NORMAL TEMPERATURES.
&&
.DISCUSSION...
AN ANTICYCLONE IN THE MID AND UPPER LEVELS REMAINS POSITIONED OFF
THE BAJA PENINSULA...RESULTING IN A WESTERLY COMPONENT TO THE FLOW.
AT THE SURFACE...YUMA VWP SUGGESTS THAT A SHALLOW GULF SURGE IS
TAKING PLACE ACROSS SOUTHWESTERN AZ. DEWPOINTS NEAR YUMA AND ACROSS
THE IMPERIAL VALLEY HAVE RESPONDED...INCREASING INTO THE MID TO UPPER
70S EARLY THIS MORNING. FURTHER EAST ACROSS THE LOWER DESERTS OF
SOUTH-CENTRAL AZ...AN INFLUX OF MOISTURE IS ALSO ANTICIPATED THIS
MORNING...BUT TO A LESSER DEGREE.
SOME EARLIER WRF-BASED GUIDANCE INDICATED THAT SHOWERS AND
THUNDERSTORMS WOULD DEVELOP THIS MORNING ACROSS PORTIONS OF THE
LOWER DESERTS. HOWEVER...THE LATEST LOCAL WRFS AND U OF ARIZONA WRFS
HAVE BACKED OFF CONSIDERABLY AND DEPICT CONVECTION BEING MOST
CONCENTRATED ACROSS THE HIGHER TERRAIN SOUTH AND EAST OF PHOENIX THIS
AFTERNOON. SEVERAL RUNS OF THE HRRR HAVE ALSO DISMISSED THE
POSSIBILITY OF CONVECTION STARTING EARLY THIS MORNING...THOUGH CAPES
ABOVE 1000 J/KG SHOULD CERTAINLY SUPPORT DEVELOPMENT BY EARLY
AFTERNOON. LACK OF A TRIGGER IN THE UPPER LEVELS ALONG WITH WEAK
WESTERLY FLOW POINT TO TERRAIN- BASED CONVERGENCE AS THE PRIMARY
LIFTING MECHANISM. NEVERTHELESS...THERE IS A SLIGHT CHANCE OF
THUNDERSTORMS IN THE PHOENIX AREA...THOUGH THE GREATER LIKELIHOOD IS
FOR AREAS OF BLOWING DUST.
MEAN FLOW WILL BECOME MORE WESTERLY SATURDAY AS THE ANTICYCLONE
DRIFTS NORTHWARD. THIS WILL AGAIN CONFINE THUNDERSTORMS MAINLY TO THE
HIGHER TERRAIN EAST OF PHOENIX. MORE OF THE SAME FOR SUNDAY AS THE
HIGH DRIFTS OVERHEAD.
CONDITIONS WILL BECOME SOMEWHAT MORE FAVORABLE FOR PRECIPITATION
EARLY NEXT WEEK AS THE MONSOON HIGH BECOMES REESTABLISHED ACROSS THE
FOUR CORNERS. INCREASING EASTERLY COMPONENT TO THE FLOW GENERALLY
FAVORS HIGHER CHANCES OF THUNDERSTORMS. HOWEVER...MODEL CROSS
SECTIONS INDICATE THAT ABUNDANT MOISTURE IN THE MID AND UPPER LEVELS
MAY RESULT IN CONSIDERABLE CLOUDINESS AND ULTIMATELY A DECREASE IN
INSTABILITY AND THE POTENTIAL FOR THUNDERSTORMS ACROSS THE AREA.
OPERATIONAL GFS AND ECMWF ALSO SUGGEST THE PRESENCE OF AN INVERTED
TROUGH ACROSS NORTHERN SONORA...THOUGH DIFFERENCES IN THE STRENGTH
AND TIMING OF THIS FEATURE ARE APPARENT.
GENERAL CONSENSUS AMONG THE MODELS FOR NEXT WEEK IS THAT THE MONSOON
HIGH WILL DRIFT EASTWARD AND SOUTHWARD. FLOW WILL GRADUALLY BECOME
SOUTHWESTERLY AGAIN...FAVORING THE HIGHER TERRAIN FOR CONVECTION.
TEMPERATURES AT OR ABOVE NORMAL ARE EXPECTED THROUGH THE EXTENDED.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL AND
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
MOSTLY CLEAR SKIES AND LIGHT WINDS AT THE TERMINAL SITES EXPECTED
OVERNIGHT THROUGH MID-DAY FRIDAY. ISOLATED THUNDERSTORMS WILL FORM
WELL EAST AND SOUTH OF PHOENIX AREA TERMINALS AFTER 20Z FRIDAY...
WITH SOUTHWEST AZ AND SOUTHEAST CA DESERT SITES REMAINING DRY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
INCREASING MONSOON MOISTURE FROM MEXICO IS EXPECTED THIS PERIOD. A
SLIGHT CHANCE OF AFTERNOON SHOWERS AND THUNDERSTORMS ARE FORECAST
OVER THE SOUTHERN GILA COUNTY MOUNTAINS THIS WEEKEND. THE CHANCE OF
SHOWERS AND THUNDERSTORMS WILL SPREAD WEST ACROSS MUCH OF SOUTHWEST
AND SOUTH CENTRAL ARIZONA MONDAY THROUGH WEDNESDAY. MINIMUM RELATIVE
HUMIDITY BECOMING 20 TO 30 PERCENT. SOUTH TO SOUTHWEST AFTERNOON
DIURNAL WINDS 10 TO 20 MPH. FAIR RECOVERY OVERNIGHT.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
AVIATION...MEYERS
FIRE WEATHER...VASQUEZ
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
425 AM PDT FRI AUG 21 2015
.SYNOPSIS...
DRY WEATHER WITH NEAR NORMAL TEMPERATURES THROUGH EARLY NEXT WEEK.
HAZY/SMOKY CONDITIONS WILL CONTINUE IN PORTIONS OF NORCAL.
&&
.DISCUSSION...
The Delta Breeze is still healthy early this morning which is
keeping temperatures in the upper 50s to mid 60s. And speaking of
temperatures, the short term forecast into Monday will be
reasonable & seasonable. Daytime highs will generally oscillate
within 5 degrees of normal. For areas influenced by the Delta
Breeze, daytime highs will be near to slightly below normal while
other areas will be near to slightly above normal. For today, Valley
highs will range upper 80s (near Delta) to upper 90s (near
Redding) while max temps in higher terrain will range in the 70s
(higher elevations of the Sierra) to the upper 80s/low 90s
(foothill locations). Very subtle warming occurs starting Saturday
as ridging strengthens over NorCal.
The main concern in the short term are the hazy/smoky conditions
due to fires that continue to burn, especially the many fires in
Trinity County. The HRRR model showed that smoke particulates from
the Trinity vicinty could move southward today towards Sacramento
area and then curl around as the Delta Breeze moves northward up
the valley. It`s going to be tricky to know where the worst smoke
conditions will be, but it`s a safe bet that much of interior
NorCal will at least be hazy the next several days.
JBB
&&
.EXTENDED DISCUSSION (Tuesday THROUGH Friday)
Near normal temperatures on Tuesday will be followed by
temperatures trending down through the rest of the week into the
weekend as a cool trough from the Gulf of Alaska approaches. How
quickly this system moves in is still in doubt, as the 00Z GFS and
ECMWF have essentially traded positions from model runs yesterday,
with the GFS now keeping a closed low off the coast and the ECMWF
bringing a quicker moving trough in on Friday. This would bring
the potential for some precipitation into far northern California
late Friday. While the GFS does keep the main low off the coast,
it does have a weak shortwave on Friday afternoon. Have introduced
just a slight chance of rain showers for the northern Coastal
Range for Friday afternoon. Will be watching to see if later model
runs trend closer together and need to expand this later.
Current Global Ensemble Forecast System (GEFS) ensembles and
analogs are pointing towards a cool down for late in the week.
Highs by Friday may stay in the 80s, even over the northern
Sacramento Valley. Increased cloud cover if the trough moves
inland would be a factor in this. EK
&&
.AVIATION...
General VFR conditions expected over the next 24 hours. MVFR with
local IFR cigs expected through the Delta until 17z, with SCT010
possible into the Sacramento metro area. Delta breeze wind gusts
to 30 kt through 17z. Mid level clouds over the northern
Sacramento Valley through this morning. Wildfire smoke around 5000
ft over the southern Sacramento Valley, and may extend to the
surface bringing some haze at times, local MVFR/IFR conditions for
the Coastal Range. EK
&&
.STO WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
949 AM EDT FRI AUG 21 2015
.UPDATE...
OLD FRONTAL BOUNDARY CURRENTLY DRAPED ACROSS CENTRAL GA THIS
MORNING. IN THE MID LEVELS...A SHEAR AXIS IS SITUATED ALMOST
DIRECTED ON TOP OF THE BOUNDARY.
WV AND 500MB RAP ANALYSIS SHOWS A WEAK WAVE SHORTWAVE ASSOCIATED
WITH THE SHOWERS ACROSS EASTERN GA THIS MORNING. THERE ARE TWO MORE
SHORTWAVES ANALYZED IN THE FLOW...ONE ACROSS CENTRAL AL AND ANOTHER
ACROSS THE ARKLAMISS. THE WAVE ACROSS CENTRAL AL SHOULD HELP SCT
CONVECTION DEVELOP THIS AFTERNOON DURING PEAK HEATING ACROSS MUCH OF
THE CWFA.
HAVE UPDATED THE POPS ACCORDING TO THE LATEST RADAR TRENDS. HAVE
ALSO TWEAKED THE AFTERNOON POPS A BIT TO COME A LITTLE MORE INTO
LINE WITH THE HRRR...WHICH HAS A PRETTY GOOD HANDLE ON THE SHRA THAT
ARE ONGOING.
LOCALLY HEAVY RAINFALL AND FREQUENT LIGHTNING STRIKES ARE THE MAIN
HAZARDS ASSOCIATED WITH ANY THUNDERSTORMS THIS AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 718 AM EDT FRI AUG 21 2015/
PREV DISCUSSION... /ISSUED 414 AM EDT FRI AUG 21 2015/
SHORT TERM /TODAY THROUGH SATURDAY/...
NAM/GFS/ECMWF IN VERY GOOD AGREEMENT THROUGH THE SHORT TERM. SURFACE
TROUGH HAS STALLED ACROSS NORTH GEORGIA KEEPING MOST OF THE CWA IN
THE WARM AND MOIST SECTOR. THIS TROUGH WILL NOT MOVE MUCH BUT SHOULD
BE A FOCUS FOR CONVECTION THIS AFTERNOON AS A WEAK WAVE MOVES ALONG
THE BOUNDARY. AFTER THIS WAVE MOVES TO OUR EAST...THE SURFACE TROUGH
WILL SHIFT SOUTH. CAPES REMAIN IN THE 1500-2000 RANGE ALONG WITH
PWATS RANGING FROM 1.8 TO 2.1 INCHES. WILL KEEP HIGH CHANCE POPS
ACROSS NORTH AND PARTS OF CENTRAL GA WHERE THE DEEPEST MOISTURE WILL
BE WITH CHANCE POPS ELSEWHERE. CONVECTION WILL DIMINISH QUICKLY THIS
EVENING. ON SATURDAY EXPECT CONVECTION AGAIN ALTHOUGH WITH SLIGHTLY
DRIER AIR OVER THE REGION WILL LIMIT POPS TO SLIGHT CHANCE TO CHANCE
AND MAINLY DURING THE AFTERNOON. GUIDANCE TEMPS HAVE BEEN RUNNING 1
TO 2 DEGREES TOO LOW OVER THE PAST 10 DAYS AND HAVE THEREFORE RAISED
MAX TEMPS BOTH DAYS BY A DEGREE OR TWO.
17
LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
THE EXTENDED FORECAST START OFF WITH WEAKENING BOUNDARY ACROSS
CENTRAL GA SUNDAY MOVING SOUTH. THE NEXT FRONTAL SYSTEM BEGINS TO
MOVE INTO N GA MONDAY MORNING BUT THERE IS NOT MUCH MOISTURE ASSOCIATED
WITH IT. THIS BOUNDARY WILL ACT AS A CATALYST FOR STORMS TO
DEVELOP ACROSS THE AREA MONDAY AND TUESDAY BUT IT WILL ALSO USHER
IN A MUCH DRIER AIRMASS TUESDAY NIGHT. THIS DRIER AIR IS EXPECTED
TO STAY ACROSS THE REGION THROUGH THURSDAY WHICH WILL KEEP
SHRA/TSRA ACTIVITY TO A MINIMUM. ALL IN ALL IT LOOKS LIKE WE MAY
BE IN THE BEGINNING STAGES OF TRANSITIONING TO A MORE FALL LIKE
PATTERN...WITH FRONTS MOVING THROUGH THE STATE GIVING THE CWA
MOSTLY CLEAR SKIES FOR A FEW DAYS AND NOT STALLING ACROSS CENTRAL
OR SOUTH GA. TEMPS REMAIN IN THE MID 80S TO MID 90S THROUGH THE
EXTENDED.
01
AVIATION...
12Z UPDATE...
ISOLATED LIGHT SHOWERS HAVE DEVELOPED AROUND THE ATL AREA AND WILL
ADD A VCSH IN THE ATL AREA TAFS AND ALSO AHN. VERY THIN AREAS OF
IFR CIGS ALSO AROUND THE ATL AREA AND WILL NEED TO INCLUDE SCT-BKN
IFR CIGS THIS MORNING. THERE SHOULD BE SOME INITIAL LIFTING WITH
DAYTIME HEATING WHICH WILL BRING SCT-BKN MVFR CIGS LATER THIS
MORNING BUT BECOMING VFR BY NOON. EXPECT SCATTERED TSRA TO DEVELOP
THIS AFTERNOON AND DIMINISH RAPIDLY AFTER SUNSET.
//ATL CONFIDENCE...12Z UPDATE...
LOW TO MEDIUM ON CIGS EARLY THIS MORNING
MEDIUM ON TIMING OF CONVECTION
HIGH ON REMAINING ELEMENTS
17
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 90 71 89 71 / 50 50 30 20
ATLANTA 89 71 90 73 / 50 50 30 20
BLAIRSVILLE 82 65 84 63 / 40 40 30 20
CARTERSVILLE 89 69 91 69 / 40 50 30 10
COLUMBUS 91 74 93 75 / 40 40 20 20
GAINESVILLE 86 71 87 71 / 50 50 30 20
MACON 92 73 93 73 / 40 40 20 20
ROME 87 68 90 69 / 40 50 30 10
PEACHTREE CITY 89 70 91 71 / 50 50 30 20
VIDALIA 93 76 94 74 / 40 40 20 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...
AVIATION...
AREA FORECAST DISCUSSION
NWS DES MOINES IA
650 AM CDT FRI AUG 21 2015
...UPDATED AVIATION DISCUSSION...
.SHORT TERM /TODAY/...
ISSUED AT 346 AM CDT FRI AUG 21 2015
MAIN FORECAST CONCERN WAS FOCUSED ON TEMPERATURES AND WINDS FOR
THIS AFTERNOON...AND WITH WEAK SHORTWAVE PROVIDING SOME ISOLATED
SHOWERS/STORMS THROUGH THE MID-MORNING. A FEW ELEVATED
SHOWERS/STORMS HAVE DEVELOPED OVER WEST-CENTRAL TO NORTHWEST IOWA
AND LOOK TO MEANDER INTO NORTH-CENTRAL IOWA THROUGH 15Z THIS
MORNING. THERE IS ENOUGH FORCING AND ELEVATED INSTABILITY...ALBEIT
VERY WEAK...BUT ENOUGH TO WARRANT SLIGHT/LOW CHANCE POPS OVER THE
NORTH. HOWEVER WITH A A STRONG CAP IN PLACE TODAY...IT WILL LIMIT
ANYTHING PAST 15Z. THE LATEST 21.07Z HRRR HAS A DECENT HANDLE ON
THE CONVECTIVE TRENDS AND LEANED TOWARD ITS SOLUTION FOR POPS/WX.
STRONG MIXING AND WAA DEVELOP TODAY AS PRESSURE GRADIENT TIGHTENS
THIS AFTERNOON. MIXING TO AROUND 850MB PUTS HIGHS IN THE LOWER 80S
AND TWEAKED MAX TEMPS UP SLIGHTLY. THE MAV/ECS HAD A GREAT HANDLE
ON TEMPS TODAY AS THE MET WAS TOO COLD THROUGHOUT THE FORECAST
AREA. ALSO TWEAKED UP WINDS SLIGHTLY AS WINDS ATOP THE MIXED LAYER
IN THE 25-30 KNOT RANGE.
.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 346 AM CDT FRI AUG 21 2015
THE LONG TERM FORECAST IS CHARACTERIZED BY VARYING TEMPERATURES
AND MOSTLY DRY CONDITIONS BUT PUNCTUATED AND HEADLINED BY THE
STORM SYSTEM MOVING ACROSS THE REGION ON SATURDAY AND SATURDAY
NIGHT. THE DRIVER FOR THIS SYSTEM WILL COME IN THE FORM OF A
MID/UPPER LEVEL TROUGH...STRONG FOR THIS SEASON...MOVING ACROSS
THE NORTHERN ROCKIES ON FRIDAY NIGHT AND OVER THE DAKOTAS AND
MINNESOTA ON SATURDAY AND SATURDAY NIGHT. THIS WILL BE REFLECTED
AT THE SURFACE BY A STEADILY STRENGTHENING
TROUGH/FRONT...INITIALLY STRETCHING DOWN THE HIGH PLAINS AND THEN
SWEEPING EAST/SOUTHEAST IN RESPONSE TO THE PROGRESSION OF THE
MID/UPPER TROUGH ON SATURDAY/SATURDAY NIGHT. AHEAD OF THIS SYSTEM
MOST OF SATURDAY WILL BE WARM AND INCREASINGLY BREEZY ACROSS OUR
FORECAST AREA AS THE SURFACE PRESSURE GRADIENT TIGHTENS UP
BETWEEN THE HIGH PLAINS TROUGH AND A LARGE HIGH PRESSURE AREA
DEPARTING TO THE EAST. FOR MUCH OF THE DAY THINGS WILL REMAIN
QUIET...BUT BY PEAK HEATING IN THE LATE AFTERNOON/EVENING
INSTABILITY WILL BE MAXIMIZED AND THE SURFACE FRONT WILL SERVE AS
A MECHANISM FOR THUNDERSTORM DEVELOPMENT COINCIDENT WITH THE
ARRIVAL OF STRONGER FORCING AND WIND FIELDS ALOFT GIVEN THE
APPROACH OF THE MID/UPPER TROUGH. INITIAL STORMS WILL LIKELY BE
ORGANIZED WITHIN THIS ENVIRONMENT PROVIDING A FAIRLY SUBSTANTIAL
SEVERE WEATHER THREAT...THEN AS THE SYSTEM MOVES EAST/SOUTHEAST
WITH SUNSET THE STORMS SHOULD BECOME MORE LINEAR AND GRADUALLY
DIMINISH IN INTENSITY BY THE TIME THEY REACH EASTERN IOWA. FOR NOW
THE PRIMARY QUESTIONS ARE WHERE THE STORMS WILL INITIALLY
DEVELOP...OVER SOUTH DAKOTA/MINNESOTA/NEBRASKA OR OVER
WESTERN/NORTHWESTERN IOWA...AND HOW FAR EAST/SOUTHEAST THEY WILL
REMAIN SEVERE AS THEY MOVE QUICKLY ACROSS THE STATE. SPC PRODUCTS
HANDLE THE THREAT WELL AND WILL BE CLOSELY MONITORED TODAY AND
TOMORROW.
AFTER THE FRONT AND ASSOCIATED STORMS BLOW THROUGH ON SATURDAY
NIGHT WE WILL ONCE AGAIN SEE MOSTLY CLEAR...COOL...AND BREEZY
WEATHER FROM SUNDAY INTO EARLY NEXT WEEK. BY MONDAY THE 500 MB
PATTERN WILL FEATURE A DEEPENING GYRE OVER THE GREAT LAKES
REGION...THAT BEING THE SYSTEM THAT AFFECTED US ON
SATURDAY/SATURDAY NIGHT...WITH A DEVELOPING RIDGE OVER THE FOUR
CORNERS REGION. INITIALLY THIS WILL PLACE IOWA BENEATH PERSISTENT
NORTHWEST FLOW RESULTING IN A VERY SLOW WARMING TREND. BY MIDWEEK
AS THE EASTERN GYRE DEPARTS THE WESTERN RIDGE WILL BUILD FURTHER
AND APPROACH OUR AREA...BUT MOST OF THE HEAT BUBBLE SHOULD REMAIN
WEST/SOUTHWEST OF IOWA THROUGH AT LEAST WEDNESDAY. THERE ARE
CONSISTENT INDICATIONS THAT A SHORTWAVE WILL OVERTOP THE 500 MB
RIDGE SOMETIME AROUND THURSDAY...POSSIBLY PROVIDING US WITH
ANOTHER CHANCE FOR RAIN BUT MORE IMPORTANTLY SHUNTING THE RIDGE
SOUTHWARD FOR A DAY OR TWO. BEYOND THIS...LOOKING TOWARD THE NEXT
WEEKEND OR SO...IT REMAINS UNCERTAIN WHETHER THE LARGE RIDGE WILL
BE ABLE TO BUILD UP OVER THE MIDWEST OR WILL REMAIN JUST TO OUR
SOUTHWEST. THIS WILL DETERMINE WHETHER WE GET ONE LAST BLAST OF
SUMMER HEAT OR NOT.
&&
.AVIATION...21/12Z
ISSUED AT 648 AM CDT FRI AUG 21 2015
VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD. ONLY CONCERN
IS WITH GUSTY WINDS LATE THIS MORNING INTO THE AFTERNOON...AND
SUSTAINED WINDS ARE EXPECTED TO PERSIST TONIGHT INTO TOMORROW
MORNING WITH A DECENT PRESSURE GRADIENT ACROSS THE STATE.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...LEE
AVIATION...PODRAZIK
AREA FORECAST DISCUSSION
NWS GOODLAND KS
545 AM MDT FRI AUG 21 2015
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 330 AM MDT FRI AUG 21 2015
FORECAST CONCERNS WILL BE THUNDERSTORM CHANCES INTO THE BEGINNING OF
THE WEEKEND AND HOW COOL TO MAKE IT SATURDAY NIGHT INTO SUNDAY
NIGHT. SATELLITE SHOWING AN AMPLIFIED/BLOCKY OVER THE PACIFIC. THIS
TRANSITIONS TO A BROAD TROUGH/WESTERLY ALOFT OVER MOST OF THE
COUNTRY. STRONG SYSTEM DIGGING INTO SOUTHWEST CANADA WITH SEVERAL
SHORTWAVE TROUGHS EMBEDDED IN THE WESTERLY FLOW.
AT JET LEVEL...MODELS DID WELL. AT MID LEVELS...THE GFS/CANADIAN AND
THE UKMET WERE DOING A LITTLE BETTER THAN THE ECMWF. THE SREF AND
ESPECIALLY THE NAM WERE NOT DOING WELL. THE GFS WAS DOING A LITTLE
BETTER THAN THE ECMWF WITH THE LOW LEVEL WIND FIELD. ALL MODELS
INITIALIZED WELL ON THE LOW LEVEL THERMAL FIELD
DIFFICULT AND UNCERTAIN PRECIPITATION FORECAST...ESPECIALLY
THROUGH THIS EVENING. CONFIDENCE IS BELOW AVERAGE FOR THE
PRECIPITATION FORECAST.
TODAY/TONIGHT...WILL HAVE TO KEEP AN EYE ON ANY LATE NIGHT/EARLY
MORNING DEVELOPMENT NEAR THE BOUNDARY JUST TO THE NORTH OF OUR
AREA. MODELS HAVE BEEN HINTING AT IT AND WILL CONTINUE TO MONITOR.
FOR YESTERDAYS THUNDERSTORMS...JUST ENOUGH MOISTURE ALONG A
BOUNDARY WITH A WEAK SHORTWAVE TROUGH WAS ABLE TO SPARK ISOLATED
THUNDERSTORMS OVER AND NEAR THE NORTHEAST PORTION OF THE AREA. NOT
TOO DIFFERENT A SETUP FOR TODAY FROM YESTERDAY. AGAIN WHAT MAKES
FORECAST UNCERTAIN IS THE MOISTURE AVAILABILITY...ESPECIALLY
ABOVE THE LOW LEVELS...WHERE DOES THE SURFACE TROUGH SETUP AND THE
WEAK/COMPLICATED MID LEVEL FORCING INVOLVED.
MODELS HAVE THE BOUNDARY PRETTY CLOSE BUT A LITTLE FURTHER WEST THAN
WHAT WAS SHOWN YESTERDAY. 700 MB SHORTWAVE EJECTS INTO THE PLAINS THIS
AFTERNOON AND IT LOOKS TO BE IN TWO PIECES. ONE PORTION GOES
ACROSS THE NORTH AND IS THE SLOWER OF THE TWO SHORTWAVE TROUGHS.
THE SECOND ONE GOES ACROSS TO OUR SOUTH AND BRUSHES THE SOUTHERN
PORTION OF THE AREA. THERE IS WEAK FORCING IN BETWEEN. ALSO THE
MODELS DIFFER ON HOW FAR EAST DURING THE DAY THEY MOVE THESE
SHORTWAVE TROUGHS.
CONVECTIVE ALLOWING MODELS ARE HAVING A DIFFICULT WITH ALL THIS. THE
ARW HAS LITTLE TO NOTHING. THE HRRR AND ESPECIALLY THE NMM DEVELOP
ROBUST CONVECTION OVER THE WESTERN PORTION OF THE AREA THIS
AFTERNOON CLOSE TO THE SURFACE TROUGH. THE 00Z NAM DID NOT INDICATE
ANYTHING BUT NOW THE 06Z NAM IS MATCHING UP WITH THE ABOVE TWO
MODELS. THE 00Z ECMWF EXPLODES CONVECTION OVER THE NORTHERN PORTION
OF THE AREA. ALL THIS TIME A RATHER STOUT EML LIES OVER THE AREA.
AFTER LOOKING AT THIS AND COLLABORATION...PULLED THE INITIATION A
LITTLE FURTHER WEST THAN BEFORE. THE PROBLEM THEN BECOMES HOW FAR
EAST TO TAKE THIS ACTIVITY. THE HRRR TAKES IT FURTHER EAST WHILE THE
REST OF THE OUTPUT THAT DID DEVELOP SOMETHING JUST KEEPS IT OVER
THE WEST AS IT EITHER DISSIPATES THE THUNDERSTORMS OR MOVES THEM
OF THE AREA TO THE NORTH OR SOUTH. SO DID LOWER POPS A LITTLE DUE
TO THIS.
IT DOES LOOK LIKE THE THUNDERSTORMS END BY 06Z. HOWEVER ELEVATED
STORMS/REDEVELOPMENT WILL NEED TO BE LOOKED AT AGAIN TO A LOW LEVEL
JET AND DECENT WARM AIR ADVECTION PATTERN ALOFT AHEAD OF ANOTHER
SHORTWAVE TROUGH. FOR THIS AFTERNOON AND EVENINGS CONVECTION...IF
STORMS DEVELOP...IT WILL BE POSSIBLE THAT THESE WILL BECOME SEVERE
DUE TO THE INSTABILITY AND LAPSE RATES INVOLVED. NO MATTER IF
STORMS DEVELOP OR NOT...BOUNDARY LAYER MOISTURE INCREASES AND AT
THE VERY LEAST A LOT OF STRATUS WILL DEVELOP WITH SOME PATCHY FOG
INVOLVED.
PRESSURE FALLS AND GRADIENT SUPPORT NEAR BREEZY OR BREEZY CONDITIONS.
GUIDANCE HAS BEEN RUNNING COOL ON MAXES HERE THE LAST FEW DAYS.
THE GFS/MAV HAS BEEN DOING THE BEST AND HAVE RAISED THE MAXES SOME.
SATURDAY/SATURDAY NIGHT...PATCHY FOG ENDS BY MID MORNING WITH THE
STRATUS LASTING A LITTLE LONGER. THERE ARE STILL DIFFERENCES IN
HOW FAST THE MODELS BRING IN THE COLD FRONT. THE NAM IS THE
SLOWEST FOLLOWED BY SREF. THE GFS/ECMWF/CANADIAN ARE THE FASTEST.
ROUGHLY IT LOOKS LIKE THE FRONT IS THROUGH THE NORTHWEST HALF OF
THE AREA BY LATE MORNING. THE FRONT THEN LOOKS TO MOVE ACROSS THE
REST OF THE AREA BY LATE AFTERNOON OR EARLY EVENING.
THE CHANCE OF THUNDERSTORMS WILL BE OVER THE SOUTHEAST PORTION OF
THE AREA IN ADVANCE OF THIS FRONT. CONTINUED THE LOW CHANCE POPS IN
THIS AREA. FRONT AND ASSOCIATED FORCING EXIT THE AREA EARLY IN
THE EVENING AND SO PRECIPITATION CUTS OFF RATHER FAST.
WINDS BEHIND THE FRONT COULD GET WINDY AND THE DAY SHIFT WILL NEED
TO LOOK AT RAISING THE WINDS EVEN MORE. DESPITE SIMILAR TIMING TO
YESTERDAYS OUTPUT...MODELS HAVE RAISED HIGH TEMPERATURES FOR THE
DAY. THE GFS...CANADIAN AND THE NAM ARE IN DECENT AGREEMENT ON
THIS. IT SEEMS THAT THE COLDER AIR DOES LAG SLIGHTLY BEHIND THE
FRONT. DID RAISE MAXES A LITTLE BUT THEY MAY NEED TO BE RAISED
EVEN MORE IN SOUTHERN LOCATIONS.
WINDS STAY UP ENOUGH TONIGHT THAT TEMPERATURES SHOULD NOT DROP
LIKE A ROCK. IF THE WINDS LET UP QUICKER...GOOD RADIATIONAL
CONDITIONS WOULD BE IN PLACE AND A LOWERING OF THE MINS WOULD BE
NEEDED.
SUNDAY/SUNDAY NIGHT...DRY PERIOD WITH POST FRONTAL COOL AIR MASS IN
PLACE. NEW GUIDANCE FOR TEMPERATURES VERY SIMILAR TO WHAT WAS IN
THERE FOR MAXES AND MADE ONLY SLIGHT ADJUSTMENTS. ONCE AGAIN FOR THE
MINS...IF WINDS END UP BEING LESS THAN CURRENTLY PREDICTED ADDITIONAL
COOLING WILL BE NEEDED.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 330 AM MDT FRI AUG 21 2015
THE EXTENDED PERIOD LOOKS TO BE MOSTLY DRY ALONG WITH NEAR TO ABOVE
NORMAL TEMPERATURES FOR THE AREA AS RIDGING INFLUENCES THE FORECAST.
ON MONDAY...AN UPPER LEVEL RIDGE CONTINUES TO BUILD INTO THE PLAINS
FOLLOWING THE SYSTEM PREDICTED TO IMPACT THE REGION THIS WEEKEND.
THE RIDGE AMPLIFIES AND MOVES EAST EARLY NEXT WEEK...WITH ITS AXIS
NEARING THE PLAINS ON WEDNESDAY. DRY CONDITIONS ARE EXPECTED DURING
THIS TIME FRAME.
MOISTURE RETURNS TO THE AREA WEDNESDAY AND THURSDAY AS A SHORTWAVE
MOVES ALONG THE PERSISTENT RIDGE. THIS DISTURBANCE LOOKS TO GENERATE
SHOWER AND THUNDERSTORM CHANCES WEDNESDAY NIGHT AND THURSDAY FOR
PORTIONS OF THE REGION.
AFTER SUNDAYS COOL DOWN...TEMPERATURES ARE EXPECTED TO QUICKLY
REBOUND IN THE EXTENDED PERIOD WITH HIGHS IN THE UPPER 80S TO LOW
90S AND LOWS IN THE UPPER 50S TO UPPER 60S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 540 AM MDT FRI AUG 21 2015
AT THIS TIME VFR CONDITIONS ARE EXPECTED AT BOTH SITES. SOUTHERLY
WINDS WILL INCREASE THIS MORNING AND BECOME GUSTY. THESE GUSTY
WINDS WILL LAST WELL INTO THE NIGHT WITH SUSTAINED SPEEDS OF 14 TO
17 KNOTS WITH GUSTS 22 TO 25 KNOTS. THUNDERSTORMS ARE EXPECTED TO
DEVELOP THIS AFTERNOON AND EVENING BUT MODEL DIFFERENCES ON TIME
AND AREA OF INITIATION MAKE THINGS A LITTLE UNCERTAIN.
AT THIS TIME ONLY FEEL COMFORTABLE ENOUGH TO PUT IN A VCTS AT BOTH
SITES WITH KGLD STARTING AT 21Z AND KMCK AT 00Z. THUNDERSTORMS ARE
EXPECTED TO BE DONE BY 03Z. LATER IN THE NIGHT SOME FOG IS
EXPECTED VISIBILITIES STAYING ABOVE MVFR.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...JBH
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
954 AM CDT FRI AUG 21 2015
.DISCUSSION...
NUM SHRA/TSRA BEGINNING TO MOVE ASHORE SE TX/SW LA IN ASSOCIATION
WITH THE NEXT UPPER LEVEL IMPULSE MOVING NE ACROSS THE TX COAST
THIS MORNING. THUS...HAD TO BUMP UP POPS AND QPF SIGNIFICANTLY
THIS MORNING...CLOSE TO HRRR GUIDANCE WHICH HAS A GOOD HANDLE ON
THIS SITUATION. ALSO INCLUDED HEAVY RAINFALL POSSIBLE AS THESE
WILL BE SOMEWHAT SLOWER MOVING. WITH THE INCREASED CLOUD COVER...AGREE
WITH HRRR AND LOWERED TEMPS ACROSS SE TX/SW LA. OTHERWISE...BUMPED
UP WINDS A BIT TO 10-15 KTS ACROSS THE COASTAL WATERS THIS MORNING
AS THIS SYSTEM MOVES ACROSS THE REGION. THATS ABOUT IT. UPDATES
ALREADY OUT.
DML
&&
.PREV DISCUSSION... /ISSUED 716 AM CDT FRI AUG 21 2015/
DISCUSSION...
FOR THE 12Z TAF PACKAGE.
AVIATION...
QUIETER NIGHT AND MORNING VERSUS THE PREVIOUS COUPLE OF
DAYS...THOUGH CONVECTIVE ACTIVITY HAS BEEN ON THE INCREASE OVER THE
COASTAL WATERS FOR THE PAST COUPLE OF HRS...ESPECIALLY OFF THE SE
TX/SW LA COASTS. LATEST HIGH RESOLUTION MODEL DATA DEPICTS THE
WELL DEFINED SHORTWAVE OVER THE MIDDLE TX COAST...AND ITS
ASSOCIATED CONVECTION...LIFTING NE THROUGH THE AREA LATER THIS
MORNING INTO THE AFTERNOON. VCTS WAS INSERTED AT EACH SITE BASED
ON THIS THINKING. RECENT PLUNGE IN VSBY AT KAEX IS EXPECTED TO BE
SHORT LIVED...PERHAPS AN HR OR SO. WILL CONTINUE TO MONITOR FOR A
POSSIBLE AMD. VFR EXPECTED TO PREVAIL OUTSIDE OF CONVECTION...AND
BY THIS EVENING AS ACTIVITY LIFTS NE OF THE AREA.
13
PREV DISCUSSION... /ISSUED 452 AM CDT FRI AUG 21 2015/
SYNOPSIS...
A NEARLY STATIONARY W-E ORIENTED SFC FRONT EXTENDS FM NE TX ACRS
NRN LA INTO CNTL MS. THE FRONT HAS BECOME A LITTLE MORE DIFFUSE
THE PAST SEVERAL HOURS...AS DEWPOINTS ALONG AND SOUTH OF THE
FRONTAL ZONE ARE IN THE LOWER TO MIDDLE 70S WITH COOLER AND DRIER
AIR LOCATED WELL BEHIND THE BOUNDARY ACRS NRN/CNTL ARK AND FAR N
MS.
THE LATEST WV IMAGERY AND UA ANALYSIS SHOWS MOISTURE ALOFT BEING
FUNNELED OVER THE REGION ON SWLY FLOW BETWEEN A TROF/WEAKNESS
OVER THE SRN PLAINS AND AN UPR RIDGE ACRS THE GULF OF MEXICO.
A LITTLE LESS CONVECTIVE ACTIVITY SO FAR TODAY THAN THE PAST
COUPLE OF MORNINGS...ALTHOUGH REGIONAL RADAR MOSAIC SHOWS SCT
SHOWERS AND A FEW TSTMS DEVELOPING OFF THE UPR TX COAST AND OVER
GALVESTON BAY WITH MORE ISOLATED ACTIVITY OVER OUR COASTAL WATERS
ZONES. FURTHER INLAND...A BAND OF LT TO MDT RAIN WAS LOCATED NEAR
THE FRONTAL BOUNDARY...FM JUST NORTH OF THE LAKES REGION OF SE TX
INTO PORTIONS OF WRN LA.
DISCUSSION...
THE FRONT WILL GRADUALLY WEAKEN AS IT LIFTS BACK NORTH LATER
TODAY. HOWEVER...ABUNDANT MOISTURE REMAINS OVER THE AREA AND WITH
THE LINGERING DISTURBANCE OR WEAKNESS ALOFT...EXPECT SCT
CONVECTION TO AGAIN DEVELOP TODAY. THIS ACTIVITY IS EXPECTED TO BE
MORE DIURNALLY DRIVEN...WITH THE SEABREEZE BOUNDARY AND THE
DISSIPATING FRONT FOCUSING CONVECTIVE DEVELOPMENT AS DAYTIME
HEATING GETS UNDERWAY. PRECIP WATER VALUES WILL REMAIN NEAR 2
INCHES...AND THIS SHOULD AGAIN ALLOW TSTMS TO BE EFFICIENT
RAINFALL PRODUCERS WITH HIGH RAIN RATES AT TIMES. CLOUDY SKIES ON
THURSDAY HELPED TO KEEP TEMPERATURES IN THE 80S...WITH SOME
LOCATIONS ONLY REACHING THE LOWER 80S. WHILE THIS MAY BE THE CASE
AGAIN TODAY...THINK CLOUD AND CONVECTIVE COVERAGE WILL BE A LITTLE
LESS AND OCCASIONAL PEEKS OF SUN SHOULD ALLOW TEMPERATURES TO RISE
TO NEAR 90 IN THE AFTN.
MEANWHILE...THE WEAKNESS ALOFT WILL MORE OR LESS LINGER OVER THE
REGION THROUGH THE WEEKEND EVEN AS THE HIGH OVER THE ERN GULF
BEGINS TO BUILD WEST. THERE WILL STILL BE A DAILY CHC FOR SHOWERS
OR STORMS SATURDAY AND SUNDAY BUT COVERAGE WILL BE LOWER AS
SLIGHTLY DRIER AIR BEGINS TO WORK INTO THE REGION. WITH LESS
CONVECTION AND CLOUDS...AFTN TEMPERATURES WILL BEGIN A WARMING
TREND.
BY EARLY NEXT WEEK...THE HIGH WILL RETROGRADE FURTHER WEST AS A
SHORTWAVE TROF DIGS OVER THE ERN STATES...WITH THE SYSTEM
GRADUALLY AMPLIFYING OVER THE CONUS. THIS WILL LEAD TO A DEEPENING
NLY FLOW THAT WILL PUSH A SFC FRONT INTO THE AREA BY TUESDAY. RAIN
CHCS WILL BUMP BACK UP IN ADVANCE OF THE FRONT MONDAY INTO
TUESDAY. GLOBAL MODELS ARE IN GENERAL AGREEMENT REGARDING THE
DEVELOPMENT OF THIS AMPLIFIED SYSTEM AND ASSOCIATED SFC
FROPA...AND KEEPING THE AREA UNDER A NLY FLOW ALOFT THROUGH THE
LATTER PART OF THE WEEK. SHOULD THIS SCENARIO PAN OUT...DRIER MORE
COMFORTABLE CONDITIONS CAN BE EXPECTED FROM WEDNESDAY THROUGH
FRIDAY WITH SLIGHTLY BELOW NORMAL LOWS IN THE UPPER 60S TO LOWER
70S AND HIGHS NEAR NORMAL IN THE LOWER 90S.
24
MARINE...
A LT TO OCCASIONALLY MDT ONSHORE FLOW AND LOW SEAS WILL PERSIST
THROUGH EARLY NEXT WEEK AS HIGH PRES CONTINUES TO RIDGE OVER THE
GULF. A LINGERING DISTURBANCE OVER THE REGION WILL ALLOW FOR SCT
SHOWERS AND TSTMS TODAY...BUT RAIN CHCS WILL DECREASE OVER THE
WEEKEND AS HIGH PRES BUILDS ALOFT. A FRONT WILL MOVE SOUTH INTO
THE AREA BY LATE MONDAY INTO TUESDAY...BRINGING ANOTHER CHC FOR
SHOWERS OR TSTMS. AT THIS TIME...MODEL GUIDANCE SHOWS THIS FRONT
MOVING SOUTH OVER THE COASTAL WATERS ZONES...WITH OFFSHORE FLOW
AND DRIER WEATHER POSSIBLE FOR THE MIDDLE AND LATTER PART OF NEXT
WEEK.
24
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 92 74 94 75 / 70 20 30 10
LCH 85 77 90 77 / 60 20 30 10
LFT 87 76 91 76 / 70 20 30 10
BPT 84 77 90 77 / 80 20 30 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
PUBLIC...08
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
810 AM CDT FRI AUG 21 2015
...SOUNDING DISCUSSION...
WINDS THROUGHOUT THE ATMOSPHERE ARE FROM THE SOUTHWEST ALLOWING
FOR MOISTURE TO REMAIN OVER THE AREA WITH A PRECIPITABLE WATER
VALUE OVER 2 INCHES. A SURFACE INVERSION AND LIGHT WINDS HAVE
ALLOWED FOR SOME FOG TO FORM WITH VISIBILITIES BEING REDUCED
GENERALLY BETWEEN 5 TO 10 MILES WHERE IT HAS FORMED. GOOD BOUNDARY
LAYER MIXING WILL OCCUR WITH MAINLY CLEAR SKIES THROUGH MID-
MORNING ALLOWING THE INVERSION TO BE REMOVED. THE CONVECTIVE
TEMPERATURE OF 86 SHOULD BE REACHED ACROSS MOST OF THE AREA AROUND
NOON TODAY AND THE 12Z HRRR SHOWS CONVECTION INCREASING IN
COVERAGE EARLY THIS AFTERNOON.
12Z BALLOON INFO: A ROUTINE FLIGHT THIS MORNING THAT LASTED 103
MINUTES. THE BALLOON REACHED A HEIGHT OF 21.5 MILES ABOVE THE
GROUND BURSTING JUST EAST OF ABITA SPRINGS 10 MILES DOWNRANGE FROM
THE OFFICE.
ANSORGE
&&
.PREV DISCUSSION... /ISSUED 340 AM CDT FRI AUG 21 2015/
SHORT TERM...
COLD FRONT STALLED OVER SOUTHERN ARK THIS MORNING WILL BEGIN TO
MOVE BACK TO THE NORTH LATER TODAY. THIS FRONT WILL BE REPLACED
WITH A SECOND FRONT MOVING INTO THE SOUTHERN ARK AREA MONDAY. THIS
SYSTEM WILL STALL FOR ABOUT 12 HOURS BEFORE MOVING SOUTHWARD ONCE
AGAIN MON NIGHT. THE AERA OF SH/TS WILL BE DEVELOPING ALONG THE
PREFRONTAL TROUGH THAT MOVES OUT AHEAD OF THE ACTUAL COLD FRONT. THIS
WILL SEND A GOOD ROUND OF SH/TS THROUGH THE AREA LATE MONDAY AND
POSSIBLY THROUGH MONDAY NIGHT. THE FRONT WILL BE ROUGHLY 10 TO 12 HOURS
BEHIND THE PREFRONTAL TROUGH AND SHOULD MOVE THROUGH LATE TUESDAY.
THIS WILL BE NOTICED AS DP TEMPS WILL DROP BACK INTO THE LOWER
60S. THIS IS STILL SEVERAL DAYS AWAY. BUT THE UPPER LONG WAVE
TROUGH DROPS INTO THE AREA AS WHAT IS LEFT OF DANNY IS BEING
PICKED UP BY IT. THIS SETS SOME HIGHER CONFIDENCE IN THIS FRONT
MAKING IT THROUGH THE AREA SINCE THE MOVEMENT OF ONE AREA OF LARGE
SCALE MASS MOVES NORTH SOMETHING EQUAL WILL NEED TO MOVE SOUTH OR
VICE VERSA. THE ONLY OTHER THING TO WATCH FOR WITH THIS SCENARIO
WILL BE THE POSSIBILITY OF SOME STRONG OR SEVERE TS ACTIVITY
MONDAY EVENING. WILL FIND BETTER TIMING AND STRENGTH OF THIS
SCENARIO WITH FUTURE FCASTS.
LONG TERM...
IF THE COLD FRONT MOVES THROUGH AND CLEARS THE AREA...WED THROUGH
THE REMAINDER OF THE WEEK IS LOOKING FANTASTIC.
AVIATION...
VFR CONDITIONS WILL GENERALLY PREVAIL THROUGH THE PERIOD. MVFR CIGS
MAY DEVELOP FOR A COUPLE HOURS NEAR DAYBREAK. WINDS WILL GENERALLY
REMAIN LESS THAN 10 KTS...EXCEPT FOR IN THE VICINITY OF SHOWERS AND
THUNDERSTORMS. SCATTERED CONVECTION IS EXPECTED TO DEVELOP THIS
AFTERNOON AND TEMPO GROUPS HAVE BEEN INCLUDED AT MOST SITES DURING
THE 18Z TO 22Z TIME FRAME.
MARINE...
GENERALLY TRANQUIL CONDITIONS WILL PREVAIL THROUGH THE PERIOD AS
WINDS ARE EXPECTED TO REMAIN 10 KNOTS OR LESS WITH WAVES NO HIGHER
THAN 2 FEET. ONLY REAL EXCEPTION WILL BE IN THE VICINITY OF
SCATTERED SHOWERS AND THUNDERSTORMS...WHERE STRONGER WINDS AND
ROUGHER SEAS WILL BE POSSIBLE. A WEAK FRONTAL BOUNDARY IS EXPECTED
TO SLIDE THROUGH THE AREA AND RESULT IN PREVAILING OFFSHORE FLOW BY
WEDNESDAY.
DECISION SUPPORT...
DSS CODE....GREEN.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...NONE.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY
ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT
TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 89 73 94 74 / 60 20 40 10
BTR 92 74 94 75 / 60 20 40 10
ASD 90 75 91 76 / 60 20 40 10
MSY 90 77 91 77 / 50 20 40 10
GPT 90 78 90 78 / 50 20 30 10
PQL 90 77 90 77 / 50 20 30 10
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GLASGOW MT
947 AM MDT FRI AUG 21 2015
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH SUNDAY...
MORNING UPDATE...
CHANGE TO THE FORECAST FOR THIS MORNING WERE FOCUSED ON SPORADIC
QPF BLOTCHES WHICH ARE SHOWING UP IN VARIOUS MODELS IN DIFFERENT
PLACES ACROSS THE CWA. WITH THE STALLED FRONTAL BOUNDARY ISOLATED
RAIN SHOWERS WILL BE POSSIBLE BUT PLACEMENT FOR THESE SHOWERS IS
GENERALLY UNKNOWN. BEST GUESS WOULD BE FORMATIONS OVER THE
CENTRAL MONTANA MOUNTAINS WERE LIGHT RAIN SHOWERS WOULD THEN
WANDER IN TO THE WESTERN ZONES OF THE CWA... BUT THEN THE RAP AND
HRRR BOTH SHOW A SHOWER FORMING OVER THE BIG SHEEP HILLS. SO EVEN
EASTERN ZONES ARE NOT OUT OF THE QUESTION TO RECEIVE VERY LIGHT
PRECIP THIS AFTERNOON. WITH A SLIGHT REWORKING OF WIND GRIDS THIS
AFTERNOON ALSO SAW THE WINDS AHEAD OF THE FRONT FALLING OFF TO
LESS THAN 10 KTS AT TIMES. HOWEVER... DIRECTLY BEHIND THE FRONT
WINDS RAMP UP FAST AND STRONG. SO... HAVE NOT TOUCHED ANY OF THE
HAZARD PRODUCTS IN ANTICIPATION OF THE KICK UP OVERNIGHT. GAH
PREVIOUS SHORT TERM DISCUSSION...
UPPER LEVEL TROUGH CURRENTLY MOVING ACROSS BRITISH COLUMBIA WILL
MOVE ACROSS EASTERN MONTANA TONIGHT AND SATURDAY. TO THE EAST...
LOW PRESSURE SYSTEM WILL DEVELOP OVER EASTERN MONTANA TODAY AND
MOVE EAST INTO NORTH DAKOTA THIS EVENING. THIS WILL DRAG A COLD
FRONT ACROSS EASTERN MONTANA THIS AFTERNOON AND EARLY EVENING.
LOOK FOR VERY WARM TEMPERATURES AND LOW RH AHEAD OF THE FRONT
TODAY. WITH GUSTY WEST WINDS EXPECTED BEHIND THE FRONT IN THE WEST
THIS AFTERNOON... WILL KEEP RED FLAG WARNING IN EFFECT. SEE FIRE
WEATHER DISCUSSION FOR MORE INFORMATION. THE DRY AIR MASS WILL
ALSO BRING A DRY FRONTAL PASSAGE FOR THE MOST PART. UNSTABLE AIR
MASS IN THE EAST MAY ALLOW FOR A SLIGHT CHANCE OF THUNDERSTORMS
THIS AFTERNOON.
A TIGHT SURFACE GRADIENT WILL DEVELOP THIS EVENING BETWEEN THE
LOW PRESSURE SYSTEM IN NORTH DAKOTA AND A SURFACE HIGH IN
ALBERTA. THIS WILL ALLOW GUSTY NORTHWEST WINDS TO DEVELOP. WILL
ISSUE A LAKE WIND ADVISORY FOR FORT PECK LAKE STARTING AT 21Z (3
PM MDT). MOISTURE WITH THIS SYSTEM WILL BE PRIMARILY IN THE UPPER
TROUGH. WILL INCREASE THE CHANCES OF SHOWERS FROM WEST TO EAST
TONIGHT AS THE UPPER TROUGH MOVES INTO THE AREA. AIR MASS MAY BE
UNSTABLE ENOUGH FOR AN ISOLATED THUNDERSTORM THIS EVENING.
THE UPPER TROUGH MOVES INTO THE DAKOTAS SATURDAY AFTERNOON WHILE
THE SURFACE LOW MOVES INTO MINNESOTA. MOISTURE ASSOCIATED WITH
THE UPPER TROUGH WILL BRING RAIN SHOWERS TO MOST OF THE FORECAST
AREA DURING THE MORNING AND IN THE EAST IN THE AFTERNOON. TIGHT
SURFACE GRADIENT REMAINS SO IT WILL BE WINDY WITH NW WINDS 20 TO
35 MPH. MUCH COLDER AIR MASS WILL BE IN PLACE WITH HIGHS 55 TO 65
OR ABOUT 30 DEGREES COLDER THAN TODAY.
HIGH PRESSURE BUILDS INTO EASTERN MONTANA SATURDAY NIGHT
DIMINISHING THE WINDS AND CLEARING THE SKIES. WITH COLDER AIR MASS
IN PLACE...SOME AREAS WILL HAVE LOWS IN THE 30S.
HIGH PRESSURE REMAINS OVER EASTERN MONTANA ON SUNDAYS WITH MOSTLY
SUNNY SKIES AND WARMER TEMPERATURES. FORRESTER
.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...
THE EXTENDED PERIOD BEGINS SUNDAY NIGHT WITH AN UPPER LEVEL RIDGE
IN PLACE OVER THE WEST. THE RIDGE AXIS WILL BE ALIGNED WITH THE
NORTHERN ROCKIES INITIALLY. THE AXIS MOVES OVER NORTHEAST MONTANA
AROUND MONDAY NIGHT...WHICH WILL ALLOW DESERT AIR TO CREEP NORTH
INTO THE LOCAL REGION. THIS WILL SEND TEMPERATURES ABOVE NORMAL
BEGINNING TUESDAY.
BY WEDNESDAY A SHORT-WAVE DISTURBANCE RIDES THE RIDGE NORTH INTO
WYOMING...UNDER-CUTTING MONTANA. MODELS SHOW SOME LOCAL INSTABILITY
DEVELOPING LATE WEDNESDAY INTO THURSDAY. THEN FRIDAY ANOTHER
EMBEDDED BUT WEAKER DISTURBANCE COULD CONTINUE THE CHANCE FOR
THUNDERSTORMS AND RAIN SHOWERS.
OVERALL...EXPECT INITIALLY NORMAL TEMPERATURES THAT INCREASE TO
ABOVE AVERAGE FOR THE MOST OF THE PERIOD. ALSO EXPECT DRY
CONDITIONS UNTIL MID-WEEK. SCT
&&
.AVIATION...
FLIGHT CATEGORY: VFR INITIALLY... MVFR/IFR BY THE END OF THE
CYCLE.
SYNOPSIS: A SURFACE TROUGH AND STALLED FRONT WILL BRING ABOUT
VEERING WIND SHIFTS. ISOLATED SHOWERS COULD ALSO FORM ON THESE
BOUNDARIES THIS AFTERNOON BUT CHANCE ARE TOO LOW TO INCLUDE IN
THE TAFS.
STORM SYSTEM: A COMPACT STORM SYSTEM WILL MOVE THROUGH THE REGION
TONIGHT BRINGING RAIN SHOWERS AND SOME THUNDERSTORMS...ALONG WITH
GUSTY NORTHWEST WIND. EXPECT CEILINGS AND VISIBILITY CONDITIONS
TO BECOME MVFR/IFR BY OR AFTER 12Z. CONDITIONS WILL BEGIN TO IMPROVE
SATURDAY NIGHT.
HAZE: CLOUDS WILL BE MIXED WITH SMOKE FROM WILD FIRES IN THE
WEST...PRODUCING A HAZY OVERCAST AT TIMES.
WINDS: FROM THE EAST AND SOUTHEAST AT LESS THAN 10 KTS THIS
MORNING... VEERING TO THE WEST THIS AFTERNOON AND INCREASING TO 10
TO 15 KTS.... THEN FURTHER VEERING TO THE NORTHWEST OVERNIGHT AND
INCREASING TO 20-30KT WHEN A STRONG COLD FRONT MOVES THROUGH THE
AREA.
GAH/SCT
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY FROM 3 PM THIS AFTERNOON TO 9 PM MDT SATURDAY
FOR FORT PECK LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL
AND SOUTHERN VALLEY...GARFIELD...MCCONE...PETROLEUM.
RED FLAG WARNING FROM NOON TODAY TO MIDNIGHT TONIGHT FOR FIRE
WEATHER ZONES 134...135...136...AND 137.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1020 AM EDT FRI AUG 21 2015
.SYNOPSIS...
A COLD FRONT WILL WAVER ACROSS THE AREA TODAY...BRINGING A
RENEWED CHANCE FOR SHOWERS AND THUNDERSTORMS. MOSTLY SUNNY AND
SEASONABLE WEATHER WILL FOLLOW FOR THE WEEKEND BEHIND THIS FRONT.
WARMER AND MORE HUMID AIR WILL RETURN NEXT WEEK AHEAD OF A COLD
FRONT WHICH WILL APPROACH ON TUESDAY...AND THEN STALL ACROSS THE
AREA THROUGH THURSDAY BRINGING COOLER AND UNSETTLED CONDITIONS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM FRIDAY...HARD TO PICK OUT THE FRONT THIS MORNING.
BASED ON WIND DIRECTIONS IT APPEARS TO BE WAVERING ACROSS THE AREA
AND MAY BE JUST OFFSHORE AT THIS TIME. ANALYSIS OF MORNING
SOUNDING DATA SHOWS A VERY MOIST ATMOSPHERE WITH DEWPOINTS WELL IN
THE 70S AND P/W VALUES APPROACHING 2.25 INCHES. NAM IS STILL
LIKING SCATTERED CONVECTION THIS AFTERNOON...ESPECIALLY NEAR THE
COAST...ALTHOUGH THE HRRR CONTINUES IN A MORE MODEST VEIN...WITH
ISOLATED SEA-BREEZE CONVECTION FIRING UP THIS AFTERNOON. KEEPING
PRESENT CHANCE POPS IN PLACE AS WITH SUCH A MOIST COLUMN IT WILL
NOT TAKE MUCH TO KICK OFF CONVECTION. PREVIOUS DISCUSSION FOLLOWS:
DESPITE GREAT MODEL-TO-MODEL CONSISTENCY 24 HOURS AGO THE COLD
FRONT IS LAGGING THOSE PROGS BY NEARLY 100 MILES THIS MORNING. AT
6 AM THE FRONT APPEARS TO LIE ROUGHLY ALONG A LINE FROM
ELIZABETHTOWN AND WHITEVILLE TO MYRTLE BEACH AND GEORGETOWN. THIS
IS ANALYZED MORE BY PRESSURE THAN WIND SINCE WINDS ARE NEARLY CALM
ON EITHER SIDE OF THE BOUNDARY. THE FRONT SHOULD CROSS THE NORTH
CAROLINA BEACHES IN THE NEXT 1-2 HOURS...BUT WITH LITTLE WIND
BEHIND THE FRONT THERE WILL BE NO SIGNIFICANT AIRMASS CHANGE.
TEMPERATURES RISING INTO THE LOWER 90S INLAND THIS AFTERNOON
SHOULD TRIGGER A SEABREEZE WHICH WILL MOVE THE EFFECTIVE LOCATION
OF THE FRONT BACK INLAND DUE TO DEVELOPING ONSHORE WINDS ALONG THE
COAST.
WITH DEWPOINTS HOLDING IN THE LOWER 70S SURFACE-BASED INSTABILITY
SHOULD GROW TO 1000-2000 J/KG THIS AFTERNOON. SYNOPTIC AND FINE-
SCALE MODELS ALL SHOW THE POTENTIAL FOR AT LEAST SCATTERED SHOWERS
AND STORMS THIS AFTERNOON...MOST NUMEROUS NEAR THE COAST WHERE
SEABREEZE-ENHANCED CONVERGENCE WILL ASSIST THE GROWING CUMULUS
CLOUDS. FORECAST POPS RANGE FROM 20 PERCENT INLAND TO 30-40 PERCENT
ON THE COAST. LIGHT TROPOSPHERIC WINDS MEAN ANY CONVECTION WILL
LIKELY BE DISORGANIZED PULSE-TYPE WITH NO SIGNIFICANT POTENTIAL FOR
SEVERE WEATHER.
DAYTIME CLOUDS WILL BE SLOW TO CLEAR TONIGHT ESPECIALLY ACROSS SOUTH
CAROLINA WHERE A MID-LEVEL DISTURBANCE IS PROGGED TO MOVE IN FROM
THE WEST DURING THE EVENING HOURS. THIS SHOULD SPREAD MID-LEVEL
CLOUDS EASTWARD TOWARD THE COAST. A SMALL CHANCE OF SHOWERS AND
STORMS WILL BE MAINTAINED OVERNIGHT ACROSS THE PEE DEE REGION DUE TO
THE MOISTURE ADVECTING EASTWARD...AND OVERNIGHT LOWS HAVE BEEN
ADJUSTED UPWARD DUE TO LESS RADIATIONAL COOLING EXPECTED.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...A BEAUTIFUL WKND IN STORE AS A COLD FRONT WILL
BE WELL SOUTH OF THE AREA...LEAVING DRYING AND MOSTLY SUNNY
CONDITIONS FOR SATURDAY AND SUNDAY. SATURDAY STILL HAS A CHANCE FOR
SOME ISOLATED SHOWERS/TSTMS ACROSS THE SOUTHERN TIER OF ZONES WHERE
PWATS WILL BE HIGHER AND THE FRONT WILL STILL BE IN THE
VICINITY...POTENTIALLY INTERACTING WITH A WEAK SHORTWAVE MOVING IN
FROM THE MIDLANDS OF SC...BUT NOT EXPECTING WIDESPREAD OR HEAVY
CONVECTION...AND INTENSITY/COVERAGE WILL DECREASE THROUGH THE
AFTN/EVE ON THE DRY ADVECTION. SUNDAY STILL SHAPING UP TO BE A
GORGEOUS DAY...ALTHOUGH FLOW IS PROGGED TO RETURN TO THE SW
EARLIER THAN PREVIOUSLY. THIS WILL CAUSE TEMPS TO BE
WARMER...ALONG WITH SLIGHTLY HIGHER HUMIDITY THAN PREVIOUSLY
FORECAST...BUT STILL EXPECT BRIGHT SUNSHINE AND A GREAT LATE-
AUGUST DAY.
TEMPS SATURDAY WILL BE AROUND SEASONABLE LEVELS AS COOL ADVECTION IS
LACKING BEHIND THE FRONT. EXPECT HIGHS AROUND 87 FAR NW TO ABOUT 90
ALONG THE SOUTHERN TIER. MAX TEMPS ON SUNDAY WILL BE ABOUT 1-3
DEGREES WARMER EVERYWHERE. SUB-CLIMO MINS SATURDAY NIGHT THANKS TO
THE DRY COLUMN...AND LOWS WILL DROP INTO THE REFRESHING
CATEGORY...DROPPING INTO THE MID 60S WELL NW TO AROUND 70 AT THE
COAST. MORE TYPICAL MINS SUNDAY NIGHT WITH LOWS A DEGREE OR TWO
EITHER SIDE OF 70.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 AM FRIDAY...MID-LEVEL FLOW TO BECOME ANOMALOUSLY AMPLIFIED
FOR AUGUST MUCH OF THE UPCOMING WEEK AS A LARGE TROUGH DEVELOPS
ACROSS THE EAST WITH A BIG RIDGE BLOSSOMING OVER THE MTN WEST.
ALTHOUGH MONDAY WILL FEATURE WARM TEMPS...POSSIBLY ABOVE
NORMAL...WITH TYPICAL SUMMERTIME CONVECTION CHANCES...THIS IS
LOOKING TO BE THE ONE ABOVE-NORMAL DAY OF THE PERIOD. THEREAFTER A
COLD FRONT DROPS INTO THE CAROLINAS AND STALLS THROUGH MID-WEEK
BEFORE FINALLY GETTING PUSHED SOUTH LATE WED INTO THU. THIS WILL
CREATE AN EXTENDED PERIOD OF UNSETTLED WEATHER WITH GOOD CHANCES FOR
SHOWERS AND THUNDERSTORMS...ALONG WITH SUB-CLIMO TEMPS THANKS TO
LOWERED THICKNESSES WITHIN THE TROUGH COMBINING WITH CLOUDS AND
PRECIP. HARD TO SAY THE ENTIRE TUE-THU PERIOD WILL BE WET AND
CLOUDY...BUT AT LEAST A GOOD PORTION OF EACH DAY LOOKS TO BE
UNSETTLED WITH HIGHS SLIGHTLY BELOW CLIMO AND LOWS SLIGHTLY ABOVE AS
DIURNAL RANGES BECOME COMPRESSED
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
AS OF 12Z...COLD FRONT PUSHING SOUTH THROUGH THE REGION AT THIS
TIME. NO WEATHER ASSOCIATED WITH IT...JUST A WIND SHIFT TO THE
NORTHWEST. THE HRRR MODEL HAS ISOLATED CONVECTION POPPING UP THIS
AFTERNOON...BUT THAT IS A BIT OF A STRETCH AS THERE WILL NOT BE MUCH
MOISTURE TO WORK WITH. WINDS CONTINUE TO VEER TO THE NORTHEAST BY
AFTERNOON. LIGHT WINDS OVERNIGHT WITH LITTLE OR NO FOG EXPECTED.
EXTENDED OUTLOOK...VFR WITH SCATTERED SHOWERS AND THUNDERSTORMS
THROUGH THE EXTENDED.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM FRIDAY...LIGHT AND VARIABLE WINDS WITH 2 FT WAVES
OVER THE WATERS THIS MORNING AS A COLD FRONT WAVERS IN THE
VICINITY. NO CHANGES TO THE FORECAST WITH THE LATEST UPDATE.
PREVIOUS DISCUSSION FOLLOWS:
SLOW-MOVING COLD FRONT SHOULD MOVE OFF THE BEACHES SHORTLY AFTER
SUNRISE THIS MORNING. WESTERLY WINDS IN ADVANCE OF THE FRONT WILL
VEER NORTHERLY LATER THIS MORNING BUT WITH NO INCREASE IN WIND
SPEED. BY THIS AFTERNOON THE TYPICAL SEABREEZE CIRCULATION SHOULD
OVERWHELM WHAT LITTLE WIND EXISTS BEHIND THE FRONT...WITH ONSHORE
WINDS 10 KNOTS OR LESS EXPECTED ALL ALONG THE COAST. ENOUGH
MOISTURE WILL REMAIN BEHIND THE FRONT THAT A FEW SHOWERS AND
STORMS SHOULD FIRE UP DURING THE AFTERNOON HOURS NEAR THE COAST
ALONG THE SEABREEZE BOUNDARY. STEERING WINDS ALOFT WILL BE LIGHT
AND FROM THE NORTHWEST...PERHAPS PUSHING ANY OF THIS ISOLATED
SHOWER/STORM ACTIVITY OUT ACROSS THE BEACHES AND INTO THE COASTAL
WATERS.
A NORTH-NORTHEAST WIND WILL GRADUALLY INCREASE LATE TONIGHT...
REACHING 10-15 KNOTS LATE. SEAS SHOULD AVERAGE ONLY 2 FEET TODAY AND
TONIGHT...PERHAPS BUILDING TO 3 FEET IN EXPOSED WATERS LATE.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...HIGH PRESSURE RIDGING DOWN THE COAST BEHIND A
COLD FRONT WILL CREATE N/NE WINDS SATURDAY AND THE FIRST HALF OF
SUNDAY. THE GRADIENT ASSOCIATED WITH THIS HIGH PRESSURE IS WEAK...SO
WIND SPEEDS WILL BE 10 KTS OR LESS FROM THIS DIRECTION...AFTER A
BRIEF SURGE UP TO 15 KTS EARLY SATURDAY. LATE SUNDAY...RETURN FLOW
WILL BEGIN TO REDEVELOP AS WINDS SHIFT BACK AROUND TO THE SW BUT AT
CONTINUED LIGHT SPEEDS. WAVE HEIGHTS WILL BE 2-3 FT EARLY DURING THE
RESIDUAL NE SURGE...BUT FALL TO 1-2 FT SATURDAY AFTN AND PERSIST AT
THESE AMPLITUDES THROUGH THE WIND SHIFT AND INTO THE END OF THE
PERIOD
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 300 AM FRIDAY...SW WINDS AHEAD OF A COLD FRONT WILL INCREASE
STEADILY DURING MONDAY...RISING UP TOWARDS 15 KTS LATE IN THE DAY.
AS THE COLD FRONT APPROACHES WINDS WILL EASE A BIT MONDAY
NIGHT...BUT THIS FRONT WILL LIKELY NOT REACH THE WATERS DURING
TUESDAY AND INSTEAD STALL JUST INLAND. THIS WILL CONTINUE S/SW WINDS
TUESDAY AT 10-15 KTS. SEAS WILL BE PRIMARILY 2-3 FT THROUGH THE
PERIOD WITH A SE GROUND SWELL AND WEAK WIND WAVE COMPRISING THE
SPECTRUM. LATE MONDAY AND INTO TUESDAY...SOME 12-SEC PERIOD SWELL
FROM DISTANT TROPICAL SYSTEMS MAY ENTER THE SPECTRUM...BUT WILL BE
AT 1 FT OR LESS IN AMPLITUDE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...REK/TRA
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...DL
MARINE...REK/TRA/JDW
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
636 AM EDT FRI AUG 21 2015
.SYNOPSIS...
A COLD FRONT WILL WAVER ACROSS THE AREA TODAY BRINGING A RENEWED
CHANCE FOR SHOWERS AND THUNDERSTORMS. MOSTLY SUNNY AND SEASONABLE
WEATHER WILL FOLLOW FOR THE WEEKEND BEHIND THIS FRONT. WARMER AND
MORE HUMID AIR WILL RETURN NEXT WEEK AHEAD OF A COLD FRONT WHICH
WILL APPROACH ON TUESDAY...AND THEN STALL ACROSS THE AREA THROUGH
THURSDAY BRINGING COOLER AND UNSETTLED CONDITIONS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM FRIDAY...DESPITE GREAT MODEL-TO-MODEL CONSISTENCY 24
HOURS AGO THE COLD FRONT IS LAGGING THOSE PROGS BY NEARLY 100 MILES
THIS MORNING. AT 6 AM THE FRONT APPEARS TO LIE ROUGHLY ALONG A LINE
FROM ELIZABETHTOWN AND WHITEVILLE TO MYRTLE BEACH AND GEORGETOWN.
THIS IS ANALYZED MORE BY PRESSURE THAN WIND SINCE WINDS ARE NEARLY
CALM ON EITHER SIDE OF THE BOUNDARY. THE FRONT SHOULD CROSS THE
NORTH CAROLINA BEACHES IN THE NEXT 1-2 HOURS...BUT WITH LITTLE WIND
BEHIND THE FRONT THERE WILL BE NO SIGNIFICANT AIRMASS CHANGE.
TEMPERATURES RISING INTO THE LOWER 90S INLAND THIS AFTERNOON SHOULD
TRIGGER A SEABREEZE WHICH WILL MOVE THE EFFECTIVE LOCATION OF THE
FRONT BACK INLAND DUE TO DEVELOPING ONSHORE WINDS ALONG THE COAST.
WITH DEWPOINTS HOLDING IN THE LOWER 70S SURFACE-BASED INSTABILITY
SHOULD GROW TO 1000-2000 J/KG THIS AFTERNOON. SYNOPTIC AND FINE-
SCALE MODELS ALL SHOW THE POTENTIAL FOR AT LEAST SCATTERED SHOWERS
AND STORMS THIS AFTERNOON...MOST NUMEROUS NEAR THE COAST WHERE
SEABREEZE-ENHANCED CONVERGENCE WILL ASSIST THE GROWING CUMULUS
CLOUDS. FORECAST POPS RANGE FROM 20 PERCENT INLAND TO 30-40 PERCENT
ON THE COAST. LIGHT TROPOSPHERIC WINDS MEAN ANY CONVECTION WILL
LIKELY BE DISORGANIZED PULSE-TYPE WITH NO SIGNIFICANT POTENTIAL FOR
SEVERE WEATHER.
DAYTIME CLOUDS WILL BE SLOW TO CLEAR TONIGHT ESPECIALLY ACROSS SOUTH
CAROLINA WHERE A MID-LEVEL DISTURBANCE IS PROGGED TO MOVE IN FROM
THE WEST DURING THE EVENING HOURS. THIS SHOULD SPREAD MID-LEVEL
CLOUDS EASTWARD TOWARD THE COAST. A SMALL CHANCE OF SHOWERS AND
STORMS WILL BE MAINTAINED OVERNIGHT ACROSS THE PEE DEE REGION DUE TO
THE MOISTURE ADVECTING EASTWARD...AND OVERNIGHT LOWS HAVE BEEN
ADJUSTED UPWARD DUE TO LESS RADIATIONAL COOLING EXPECTED.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...A BEAUTIFUL WKND IN STORE AS A COLD FRONT WILL
BE WELL SOUTH OF THE AREA...LEAVING DRYING AND MOSTLY SUNNY
CONDITIONS FOR SATURDAY AND SUNDAY. SATURDAY STILL HAS A CHANCE FOR
SOME ISOLATED SHOWERS/TSTMS ACROSS THE SOUTHERN TIER OF ZONES WHERE
PWATS WILL BE HIGHER AND THE FRONT WILL STILL BE IN THE
VICINITY...POTENTIALLY INTERACTING WITH A WEAK SHORTWAVE MOVING IN
FROM THE MIDLANDS OF SC...BUT NOT EXPECTING WIDESPREAD OR HEAVY
CONVECTION...AND INTENSITY/COVERAGE WILL DECREASE THROUGH THE
AFTN/EVE ON THE DRY ADVECTION. SUNDAY STILL SHAPING UP TO BE A
GORGEOUS DAY...ALTHOUGH FLOW IS PROGGED TO RETURN TO THE SW
EARLIER THAN PREVIOUSLY. THIS WILL CAUSE TEMPS TO BE
WARMER...ALONG WITH SLIGHTLY HIGHER HUMIDITY THAN PREVIOUSLY
FORECAST...BUT STILL EXPECT BRIGHT SUNSHINE AND A GREAT LATE-
AUGUST DAY.
TEMPS SATURDAY WILL BE AROUND SEASONABLE LEVELS AS COOL ADVECTION IS
LACKING BEHIND THE FRONT. EXPECT HIGHS AROUND 87 FAR NW TO ABOUT 90
ALONG THE SOUTHERN TIER. MAX TEMPS ON SUNDAY WILL BE ABOUT 1-3
DEGREES WARMER EVERYWHERE. SUB-CLIMO MINS SATURDAY NIGHT THANKS TO
THE DRY COLUMN...AND LOWS WILL DROP INTO THE REFRESHING
CATEGORY...DROPPING INTO THE MID 60S WELL NW TO AROUND 70 AT THE
COAST. MORE TYPICAL MINS SUNDAY NIGHT WITH LOWS A DEGREE OR TWO
EITHER SIDE OF 70.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 AM FRIDAY...MID-LEVEL FLOW TO BECOME ANOMALOUSLY AMPLIFIED
FOR AUGUST MUCH OF THE UPCOMING WEEK AS A LARGE TROUGH DEVELOPS
ACROSS THE EAST WITH A BIG RIDGE BLOSSOMING OVER THE MTN WEST.
ALTHOUGH MONDAY WILL FEATURE WARM TEMPS...POSSIBLY ABOVE
NORMAL...WITH TYPICAL SUMMERTIME CONVECTION CHANCES...THIS IS
LOOKING TO BE THE ONE ABOVE-NORMAL DAY OF THE PERIOD. THEREAFTER A
COLD FRONT DROPS INTO THE CAROLINAS AND STALLS THROUGH MID-WEEK
BEFORE FINALLY GETTING PUSHED SOUTH LATE WED INTO THU. THIS WILL
CREATE AN EXTENDED PERIOD OF UNSETTLED WEATHER WITH GOOD CHANCES FOR
SHOWERS AND THUNDERSTORMS...ALONG WITH SUB-CLIMO TEMPS THANKS TO
LOWERED THICKNESSES WITHIN THE TROUGH COMBINING WITH CLOUDS AND
PRECIP. HARD TO SAY THE ENTIRE TUE-THU PERIOD WILL BE WET AND
CLOUDY...BUT AT LEAST A GOOD PORTION OF EACH DAY LOOKS TO BE
UNSETTLED WITH HIGHS SLIGHTLY BELOW CLIMO AND LOWS SLIGHTLY ABOVE AS
DIURNAL RANGES BECOME COMPRESSED
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 12Z...COLD FRONT PUSHING SOUTH THROUGH THE REGION AT THIS
TIME. NO WEATHER ASSOCIATED WITH IT...JUST A WIND SHIFT TO THE
NORTHWEST. THE HRRR MODEL HAS ISOLATED CONVECTION POPPING UP THIS
AFTERNOON...BUT THAT IS A BIT OF A STRETCH AS THERE WILL NOT BE MUCH
MOISTURE TO WORK WITH. WINDS CONTINUE TO VEER TO THE NORTHEAST BY
AFTERNOON. LIGHT WINDS OVERNIGHT WITH LITTLE OR NO FOG EXPECTED.
EXTENDED OUTLOOK...VFR WITH SCATTERED SHOWERS AND THUNDERSTORMS
THROUGH THE EXTENDED.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM FRIDAY...SLOW-MOVING COLD FRONT SHOULD MOVE OFF THE
BEACHES SHORTLY AFTER SUNRISE THIS MORNING. WESTERLY WINDS IN
ADVANCE OF THE FRONT WILL VEER NORTHERLY LATER THIS MORNING BUT WITH
NO INCREASE IN WIND SPEED. BY THIS AFTERNOON THE TYPICAL SEABREEZE
CIRCULATION SHOULD OVERWHELM WHAT LITTLE WIND EXISTS BEHIND THE
FRONT...WITH ONSHORE WINDS 10 KNOTS OR LESS EXPECTED ALL ALONG THE
COAST. ENOUGH MOISTURE WILL REMAIN BEHIND THE FRONT THAT A FEW
SHOWERS AND STORMS SHOULD FIRE UP DURING THE AFTERNOON HOURS NEAR
THE COAST ALONG THE SEABREEZE BOUNDARY. STEERING WINDS ALOFT WILL BE
LIGHT AND FROM THE NORTHWEST...PERHAPS PUSHING ANY OF THIS ISOLATED
SHOWER/STORM ACTIVITY OUT ACROSS THE BEACHES AND INTO THE COASTAL
WATERS.
A NORTH-NORTHEAST WIND WILL GRADUALLY INCREASE LATE TONIGHT...
REACHING 10-15 KNOTS LATE. SEAS SHOULD AVERAGE ONLY 2 FEET TODAY AND
TONIGHT...PERHAPS BUILDING TO 3 FEET IN EXPOSED WATERS LATE.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...HIGH PRESSURE RIDGING DOWN THE COAST BEHIND A
COLD FRONT WILL CREATE N/NE WINDS SATURDAY AND THE FIRST HALF OF
SUNDAY. THE GRADIENT ASSOCIATED WITH THIS HIGH PRESSURE IS WEAK...SO
WIND SPEEDS WILL BE 10 KTS OR LESS FROM THIS DIRECTION...AFTER A
BRIEF SURGE UP TO 15 KTS EARLY SATURDAY. LATE SUNDAY...RETURN FLOW
WILL BEGIN TO REDEVELOP AS WINDS SHIFT BACK AROUND TO THE SW BUT AT
CONTINUED LIGHT SPEEDS. WAVE HEIGHTS WILL BE 2-3 FT EARLY DURING THE
RESIDUAL NE SURGE...BUT FALL TO 1-2 FT SATURDAY AFTN AND PERSIST AT
THESE AMPLITUDES THROUGH THE WIND SHIFT AND INTO THE END OF THE
PERIOD
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 300 AM FRIDAY...SW WINDS AHEAD OF A COLD FRONT WILL INCREASE
STEADILY DURING MONDAY...RISING UP TOWARDS 15 KTS LATE IN THE DAY.
AS THE COLD FRONT APPROACHES WINDS WILL EASE A BIT MONDAY
NIGHT...BUT THIS FRONT WILL LIKELY NOT REACH THE WATERS DURING
TUESDAY AND INSTEAD STALL JUST INLAND. THIS WILL CONTINUE S/SW WINDS
TUESDAY AT 10-15 KTS. SEAS WILL BE PRIMARILY 2-3 FT THROUGH THE
PERIOD WITH A SE GROUND SWELL AND WEAK WIND WAVE COMPRISING THE
SPECTRUM. LATE MONDAY AND INTO TUESDAY...SOME 12-SEC PERIOD SWELL
FROM DISTANT TROPICAL SYSTEMS MAY ENTER THE SPECTRUM...BUT WILL BE
AT 1 FT OR LESS IN AMPLITUDE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...TRA
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...43
MARINE...TRA/JDW
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
630 AM EDT FRI AUG 21 2015
.SYNOPSIS...
A COLD FRONT WILL WAVER ACROSS THE AREA TODAY BRINGING A RENEWED
CHANCE FOR SHOWERS AND THUNDERSTORMS. MOSTLY SUNNY AND SEASONABLE
WEATHER WILL FOLLOW FOR THE WEEKEND BEHIND THIS FRONT. WARMER AND
MORE HUMID AIR WILL RETURN NEXT WEEK AHEAD OF A COLD FRONT WHICH
WILL APPROACH ON TUESDAY...AND THEN STALL ACROSS THE AREA THROUGH
THURSDAY BRINGING COOLER AND UNSETTLED CONDITIONS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM FRIDAY...DESPITE GREAT MODEL-TO-MODEL CONSISTENCY 24
HOURS AGO THE COLD FRONT IS LAGGING THOSE PROGS BY NEARLY 100 MILES
THIS MORNING. AT 3 AM THE FRONT APPEARS TO LIE ROUGHLY ALONG
INTERSTATE 95...MOVING EASTWARD TOWARD THE COAST AT A SLOW PACE. THE
FRONT SHOULD CROSS THE BEACHES SHORTLY AFTER SUNRISE...BUT WITH
LITTLE WIND BEHIND THE FRONT THERE WILL BE NO SIGNIFICANT AIRMASS
CHANGE. TEMPERATURES RISING INTO THE LOWER 90S INLAND THIS AFTERNOON
SHOULD TRIGGER A SEABREEZE WHICH WILL MOVE THE EFFECTIVE LOCATION OF
THE FRONT BACK INLAND DUE TO DEVELOPING ONSHORE WINDS ALONG THE
COAST.
WITH DEWPOINTS HOLDING IN THE LOWER 70S SURFACE-BASED INSTABILITY
SHOULD GROW TO 1000-2000 J/KG THIS AFTERNOON. SYNOPTIC AND FINE-
SCALE MODELS ALL SHOW THE POTENTIAL FOR AT LEAST SCATTERED SHOWERS
AND STORMS THIS AFTERNOON...MOST NUMEROUS NEAR THE COAST WHERE
SEABREEZE-ENHANCED CONVERGENCE WILL ASSIST THE GROWING CUMULUS
CLOUDS. FORECAST POPS RANGE FROM 20 PERCENT INLAND TO 40 PERCENT ON
THE COAST. LIGHT TROPOSPHERIC WINDS MEAN ANY CONVECTION WILL LIKELY
BE DISORGANIZED PULSE-TYPE WITH NO SIGNIFICANT POTENTIAL FOR SEVERE
WEATHER.
DAYTIME CLOUDS WILL BE SLOW TO CLEAR TONIGHT ESPECIALLY ACROSS SOUTH
CAROLINA WHERE A MID-LEVEL DISTURBANCE IS PROGGED TO MOVE IN FROM
THE WEST DURING THE EVENING HOURS. THIS SHOULD SPREAD MID-LEVEL
CLOUDS EASTWARD TOWARD THE COAST. A SMALL CHANCE OF SHOWERS AND
STORMS WILL BE MAINTAINED OVERNIGHT ACROSS THE PEE DEE REGION DUE TO
THE MOISTURE ADVECTING EASTWARD...AND OVERNIGHT LOWS HAVE BEEN
ADJUSTED UPWARD DUE TO LESS RADIATIONAL COOLING EXPECTED.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...A BEAUTIFUL WKND IN STORE AS A COLD FRONT WILL
BE WELL SOUTH OF THE AREA...LEAVING DRYING AND MOSTLY SUNNY
CONDITIONS FOR SATURDAY AND SUNDAY. SATURDAY STILL HAS A CHANCE FOR
SOME ISOLATED SHOWERS/TSTMS ACROSS THE SOUTHERN TIER OF ZONES WHERE
PWATS WILL BE HIGHER AND THE FRONT WILL STILL BE IN THE
VICINITY...POTENTIALLY INTERACTING WITH A WEAK SHORTWAVE MOVING IN
FROM THE MIDLANDS OF SC...BUT NOT EXPECTING WIDESPREAD OR HEAVY
CONVECTION...AND INTENSITY/COVERAGE WILL DECREASE THROUGH THE
AFTN/EVE ON THE DRY ADVECTION. SUNDAY STILL SHAPING UP TO BE A
GORGEOUS DAY...ALTHOUGH FLOW IS PROGGED TO RETURN TO THE SW
EARLIER THAN PREVIOUSLY. THIS WILL CAUSE TEMPS TO BE
WARMER...ALONG WITH SLIGHTLY HIGHER HUMIDITY THAN PREVIOUSLY
FORECAST...BUT STILL EXPECT BRIGHT SUNSHINE AND A GREAT LATE-
AUGUST DAY.
TEMPS SATURDAY WILL BE AROUND SEASONABLE LEVELS AS COOL ADVECTION IS
LACKING BEHIND THE FRONT. EXPECT HIGHS AROUND 87 FAR NW TO ABOUT 90
ALONG THE SOUTHERN TIER. MAX TEMPS ON SUNDAY WILL BE ABOUT 1-3
DEGREES WARMER EVERYWHERE. SUB-CLIMO MINS SATURDAY NIGHT THANKS TO
THE DRY COLUMN...AND LOWS WILL DROP INTO THE REFRESHING
CATEGORY...DROPPING INTO THE MID 60S WELL NW TO AROUND 70 AT THE
COAST. MORE TYPICAL MINS SUNDAY NIGHT WITH LOWS A DEGREE OR TWO
EITHER SIDE OF 70.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 AM FRIDAY...MID-LEVEL FLOW TO BECOME ANOMALOUSLY AMPLIFIED
FOR AUGUST MUCH OF THE UPCOMING WEEK AS A LARGE TROUGH DEVELOPS
ACROSS THE EAST WITH A BIG RIDGE BLOSSOMING OVER THE MTN WEST.
ALTHOUGH MONDAY WILL FEATURE WARM TEMPS...POSSIBLY ABOVE
NORMAL...WITH TYPICAL SUMMERTIME CONVECTION CHANCES...THIS IS
LOOKING TO BE THE ONE ABOVE-NORMAL DAY OF THE PERIOD. THEREAFTER A
COLD FRONT DROPS INTO THE CAROLINAS AND STALLS THROUGH MID-WEEK
BEFORE FINALLY GETTING PUSHED SOUTH LATE WED INTO THU. THIS WILL
CREATE AN EXTENDED PERIOD OF UNSETTLED WEATHER WITH GOOD CHANCES FOR
SHOWERS AND THUNDERSTORMS...ALONG WITH SUB-CLIMO TEMPS THANKS TO
LOWERED THICKNESSES WITHIN THE TROUGH COMBINING WITH CLOUDS AND
PRECIP. HARD TO SAY THE ENTIRE TUE-THU PERIOD WILL BE WET AND
CLOUDY...BUT AT LEAST A GOOD PORTION OF EACH DAY LOOKS TO BE
UNSETTLED WITH HIGHS SLIGHTLY BELOW CLIMO AND LOWS SLIGHTLY ABOVE AS
DIURNAL RANGES BECOME COMPRESSED
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 12Z...COLD FRONT PUSHING SOUTH THROUGH THE REGION AT THIS
TIME. NO WEATHER ASSOCIATED WITH IT...JUST A WIND SHIFT TO THE
NORTHWEST. THE HRRR MODEL HAS ISOLATED CONVECTION POPPING UP THIS
AFTERNOON...BUT THAT IS A BIT OF A STRETCH AS THERE WILL NOT BE MUCH
MOISTURE TO WORK WITH. WINDS CONTINUE TO VEER TO THE NORTHEAST BY
AFTERNOON. LIGHT WINDS OVERNIGHT WITH LITTLE OR NO FOG EXPECTED.
EXTENDED OUTLOOK...VFR WITH SCATTERED SHOWERS AND THUNDERSTORMS
THROUGH THE EXTENDED.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM FRIDAY...A SLOW-MOVING COLD FRONT SHOULD MOVE OFF THE
BEACHES SHORTLY AFTER SUNRISE THIS MORNING. WESTERLY WINDS IN
ADVANCE OF THE FRONT WILL VEER NORTHERLY THIS MORNING BUT WITH NO
INCREASE IN WIND SPEED. BY THIS AFTERNOON THE TYPICAL SEABREEZE
CIRCULATION SHOULD OVERWHELM WHAT LITTLE WIND EXISTS BEHIND THE
FRONT...WITH ONSHORE WINDS 10 KNOTS OR LESS EXPECTED ALL ALONG THE
COAST. ENOUGH MOISTURE WILL REMAIN BEHIND THE FRONT THAT SCATTERED
SHOWERS AND STORMS SHOULD FIRE UP DURING THE AFTERNOON HOURS NEAR
THE COAST ALONG THE SEABREEZE BOUNDARY. STEERING WINDS ALOFT WILL BE
LIGHT AND FROM THE NORTHWEST...PERHAPS PUSHING ANY SHOWERS AND
STORMS OUT ACROSS THE BEACHES AND INTO THE COASTAL WATERS.
A NORTH-NORTHEAST WIND WILL GRADUALLY INCREASE LATE
TONIGHT...REACHING 10-15 KNOTS LATE. SEAS SHOULD AVERAGE ONLY 2 FEET
TODAY AND TONIGHT...PERHAPS BUILDING TO 3 FEET IN EXPOSED WATERS
LATE.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...HIGH PRESSURE RIDGING DOWN THE COAST BEHIND A
COLD FRONT WILL CREATE N/NE WINDS SATURDAY AND THE FIRST HALF OF
SUNDAY. THE GRADIENT ASSOCIATED WITH THIS HIGH PRESSURE IS WEAK...SO
WIND SPEEDS WILL BE 10 KTS OR LESS FROM THIS DIRECTION...AFTER A
BRIEF SURGE UP TO 15 KTS EARLY SATURDAY. LATE SUNDAY...RETURN FLOW
WILL BEGIN TO REDEVELOP AS WINDS SHIFT BACK AROUND TO THE SW BUT AT
CONTINUED LIGHT SPEEDS. WAVE HEIGHTS WILL BE 2-3 FT EARLY DURING THE
RESIDUAL NE SURGE...BUT FALL TO 1-2 FT SATURDAY AFTN AND PERSIST AT
THESE AMPLITUDES THROUGH THE WIND SHIFT AND INTO THE END OF THE
PERIOD
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 300 AM FRIDAY...SW WINDS AHEAD OF A COLD FRONT WILL INCREASE
STEADILY DURING MONDAY...RISING UP TOWARDS 15 KTS LATE IN THE DAY.
AS THE COLD FRONT APPROACHES WINDS WILL EASE A BIT MONDAY
NIGHT...BUT THIS FRONT WILL LIKELY NOT REACH THE WATERS DURING
TUESDAY AND INSTEAD STALL JUST INLAND. THIS WILL CONTINUE S/SW WINDS
TUESDAY AT 10-15 KTS. SEAS WILL BE PRIMARILY 2-3 FT THROUGH THE
PERIOD WITH A SE GROUND SWELL AND WEAK WIND WAVE COMPRISING THE
SPECTRUM. LATE MONDAY AND INTO TUESDAY...SOME 12-SEC PERIOD SWELL
FROM DISTANT TROPICAL SYSTEMS MAY ENTER THE SPECTRUM...BUT WILL BE
AT 1 FT OR LESS IN AMPLITUDE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...TRA
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...43
MARINE...TRA/JDW
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
955 AM CDT FRI AUG 21 2015
.UPDATE...
ISSUED AT 955 AM CDT FRI AUG 21 2015
WE ARE GETTING SMOKE INTO THE REGION...AND THIS WILL IMPACT HIGH
TEMPS SOME TODAY. WE WILL LOWER TEMPS TODAY ABOUT 2-4 DEGREES
GIVEN THICKER HIGH LEVEL SMOKE. OTHERWISE...NO OTHER MAJOR CHANGES
NEEDED.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 345 AM CDT FRI AUG 21 2015
FORECAST CHALLENGES WILL BE SEVERE THREAT SATURDAY AS WELL AS RAINFALL
AMOUNTS MAINLY THIS WEEKEND AND TEMPERATURES/WIND. MODELS OVERALL
IN PRETTY GOOD AGREEMENT THROUGH THE PERIOD AND WILL USE MODEL
BLEND.
CURRENT SHORTWAVE PROPAGATING EAST ACROSS SW MB INTO ONTARIO THIS
MORNING. ASSOCIATED AREA OF SHRA/ISOLD T ON NOSE OF LOW LEVEL JET
IN WARM ADVECTION ZONE. ALTHOUGH INSTABILITY AND CAPE MINIMAL A
FEW LIGHTNING STRIKES OCCURRING. CURRENT HRRR WEAKENS PCPN
THROUGH THE MORNING AND OUT OF THE FA BY MID MORNING. WILL
MAINTAIN LOW POPS BASED ON SHORT TERM MODEL GUIDANCE. THE
REMAINDER OF THIS AFTERNOON SHOULD REMAIN DRY. CONTINUED WARM
ADVECTION WILL SET UP WARM FRONTAL BOUNDARY ALONG THE
INTERNATIONAL BORDER BY THIS EVENING. WITH FA IN WARM SECTOR
TEMPERATURES SHOULD RECOVER WELL WITH MOST AREAS ABOVE AVERAGE.
TONIGHT MORE SIGNIFICANT WAVE CURRENTLY OVER BC WILL DIG INTO THE
NORTHERN ROCKIES. ASSOCIATED SURFACE LOW WILL ORGANIZE OVER THE
WESTERN DAKOTAS WITH SW-NE ORIENTED BOUNDARY SETTING UP LATER IN
THE NIGHT. WILL CONTINUE WITH CHANCE POPS ALONG THIS BOUNDARY.
TEMPERATURES WILL REMAIN MILD OVERNIGHT.
SURFACE LOW WILL LIFT NE SATURDAY AS WAVE APPROACHES. AS IT DOES
ASSOCIATED COLD FRONT WILL FOLLOW LOW AND BE ORIENTED CLOSE TO THE
VALLEY BY PRIME HEATING. CONVECTIVE PARAMETERS FAVORABLE FOR
SEVERE STORMS ALONG AND AHEAD OF THE BOUNDARY SO SEVERE POTENTIAL
WILL HINGE ON JUST WHERE BOUNDARY SETS UP. DEGREE OF CLOUD COVER
WILL GOVERN TEMPERATURES WITH COOLEST READINGS OVER THE FAR NW
WHICH WILL BE BEHIND THE COLD FRONT.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 345 AM CDT FRI AUG 21 2015
UPPER TROUGH CLOSES OFF SATURDAY NIGHT AS IT LIFTS NE. WRAP
AROUND/DEF ZONE RAIN WILL FOLLOW. AT THIS POINT MODEL GUIDANCE
SUGGESTS THAT THE BEST POTENTIAL FOR RAIN WILL BE OVER THE
NORTHERN 2/3RD OF THE FA.
SUNDAY WILL BE WINDY AND COOLER WITH DEF ZONE PCPN BAND SHIFTING
EAST ACROSS THE FA. COOLER COLUMN AND CLOUDS WILL HOLD
TEMPERATURES DOWN.
RAIN WILL MOVE OUT OF THE NE FA SUNDAY NIGHT. WINDS TO DIMINISH
BUT WILL BE A COOL NIGHT WITH MINIMUM TEMPERATURES IN THE 40S.
LONG WAVE TROUGHS WERE OFF THE WESTERN CANADIAN COAST AND THE GREAT
LAKES WITH A FLAT RIDGE OVER MT. PATTERN AMPLIFIES WITH A TROUGH
OVER THE EASTERN PACIFIC/WESTERN CANADA AND RIDGING INTO THE
NORTHERN PLAINS BY THE END OF THE PERIOD.
GFS AND ECMWF WERE IN BETTER AGREEMENT WITH TODAYS MODEL RUN THROUGH
THE PERIOD. THE ECMWF WAS SLIGHTLY FASTER THAN THE GFS. THE ECMWF
WAS VACILLATING AROUND A POINT WHILE THE GFS WAS TRENDING SLOWER
OVER THE LAST COUPLE MODEL RUNS.
NO CHANGE TO HIGH TEMPS FOR MON. HIGH TEMPS WERE DECREASED A DEGREE
OR TWO FOR TUE AND WED, AND INCREASED ZERO TO FOUR DEGREES FOR THU
FORM YESTERDAYS PACKAGE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 639 AM CDT FRI AUG 21 2015
CIGS ASSOCIATED WITH SHRA OVER THE NORTHERN FA REMAIN IN THE MID
LEVELS WITH CLEARING REACHING THE NORTHERN VALLEY. EXPECT MID
LEVEL CIGS TO EXIT THE FA BY LATE MORNING WITH VFR CONDITIONS
CONTINUING THROUGH THE REMAINDER OF THE PERIOD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...DK
SHORT TERM...VOELKER
LONG TERM...HOPPES/VOELKER
AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
644 AM CDT FRI AUG 21 2015
.UPDATE...
ISSUED AT 639 AM CDT FRI AUG 21 2015
SHRA SHRINKING IN COVERAGE AND CONFINED TO NW MN EAST OF NORTHERN
VALLEY. NO LTG STRIKES IN THE LAST FEW HOURS SO TRANSITIONED BACK
TO SHRA. MADE SOME MINOR POP ADJUSTMENTS THROUGH THE REMAINDER OF
THE MORNING WITH NO OTHER FORECAST CHANGES.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 345 AM CDT FRI AUG 21 2015
FORECAST CHALLENGES WILL BE SEVERE THREAT SATURDAY AS WELL AS RAINFALL
AMOUNTS MAINLY THIS WEEKEND AND TEMPERATURES/WIND. MODELS OVERALL
IN PRETTY GOOD AGREEMENT THROUGH THE PERIOD AND WILL USE MODEL
BLEND.
CURRENT SHORTWAVE PROPAGATING EAST ACROSS SW MB INTO ONTARIO THIS
MORNING. ASSOCIATED AREA OF SHRA/ISOLD T ON NOSE OF LOW LEVEL JET
IN WARM ADVECTION ZONE. ALTHOUGH INSTABILITY AND CAPE MINIMAL A
FEW LIGHTNING STRIKES OCCURRING. CURRENT HRRR WEAKENS PCPN
THROUGH THE MORNING AND OUT OF THE FA BY MID MORNING. WILL
MAINTAIN LOW POPS BASED ON SHORT TERM MODEL GUIDANCE. THE
REMAINDER OF THIS AFTERNOON SHOULD REMAIN DRY. CONTINUED WARM
ADVECTION WILL SET UP WARM FRONTAL BOUNDARY ALONG THE
INTERNATIONAL BORDER BY THIS EVENING. WITH FA IN WARM SECTOR
TEMPERATURES SHOULD RECOVER WELL WITH MOST AREAS ABOVE AVERAGE.
TONIGHT MORE SIGNIFICANT WAVE CURRENTLY OVER BC WILL DIG INTO THE
NORTHERN ROCKIES. ASSOCIATED SURFACE LOW WILL ORGANIZE OVER THE
WESTERN DAKOTAS WITH SW-NE ORIENTED BOUNDARY SETTING UP LATER IN
THE NIGHT. WILL CONTINUE WITH CHANCE POPS ALONG THIS BOUNDARY.
TEMPERATURES WILL REMAIN MILD OVERNIGHT.
SURFACE LOW WILL LIFT NE SATURDAY AS WAVE APPROACHES. AS IT DOES
ASSOCIATED COLD FRONT WILL FOLLOW LOW AND BE ORIENTED CLOSE TO THE
VALLEY BY PRIME HEATING. CONVECTIVE PARAMETERS FAVORABLE FOR
SEVERE STORMS ALONG AND AHEAD OF THE BOUNDARY SO SEVERE POTENTIAL
WILL HINGE ON JUST WHERE BOUNDARY SETS UP. DEGREE OF CLOUD COVER
WILL GOVERN TEMPERATURES WITH COOLEST READINGS OVER THE FAR NW
WHICH WILL BE BEHIND THE COLD FRONT.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 345 AM CDT FRI AUG 21 2015
UPPER TROUGH CLOSES OFF SATURDAY NIGHT AS IT LIFTS NE. WRAP
AROUND/DEF ZONE RAIN WILL FOLLOW. AT THIS POINT MODEL GUIDANCE
SUGGESTS THAT THE BEST POTENTIAL FOR RAIN WILL BE OVER THE
NORTHERN 2/3RD OF THE FA.
SUNDAY WILL BE WINDY AND COOLER WITH DEF ZONE PCPN BAND SHIFTING
EAST ACROSS THE FA. COOLER COLUMN AND CLOUDS WILL HOLD
TEMPERATURES DOWN.
RAIN WILL MOVE OUT OF THE NE FA SUNDAY NIGHT. WINDS TO DIMINISH
BUT WILL BE A COOL NIGHT WITH MINIMUM TEMPERATURES IN THE 40S.
LONG WAVE TROUGHS WERE OFF THE WESTERN CANADIAN COAST AND THE GREAT
LAKES WITH A FLAT RIDGE OVER MT. PATTERN AMPLIFIES WITH A TROUGH
OVER THE EASTERN PACIFIC/WESTERN CANADA AND RIDGING INTO THE
NORTHERN PLAINS BY THE END OF THE PERIOD.
GFS AND ECMWF WERE IN BETTER AGREEMENT WITH TODAYS MODEL RUN THROUGH
THE PERIOD. THE ECMWF WAS SLIGHTLY FASTER THAN THE GFS. THE ECMWF
WAS VACILLATING AROUND A POINT WHILE THE GFS WAS TRENDING SLOWER
OVER THE LAST COUPLE MODEL RUNS.
NO CHANGE TO HIGH TEMPS FOR MON. HIGH TEMPS WERE DECREASED A DEGREE
OR TWO FOR TUE AND WED, AND INCREASED ZERO TO FOUR DEGREES FOR THU
FORM YESTERDAYS PACKAGE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 639 AM CDT FRI AUG 21 2015
CIGS ASSOCIATED WITH SHRA OVER THE NORTHERN FA REMAIN IN THE MID
LEVELS WITH CLEARING REACHING THE NORTHERN VALLEY. EXPECT MID
LEVEL CIGS TO EXIT THE FA BY LATE MORNING WITH VFR CONDITIONS
CONTINUING THROUGH THE REMAINDER OF THE PERIOD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...VOELKER
SHORT TERM...VOELKER
LONG TERM...HOPPES/VOELKER
AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
1114 AM EDT FRI AUG 21 2015
.DISCUSSION...
POST-FRONTAL HIGH PRESSURE FILLING INTO THE REGION. DEW POINTS
GETTING A LITTLE LOWER AHEAD OF SCHEDULE...ACROSS THE BOARD...SO
LOWERED DEW POINTS 1-3 DEG AS NEEDED. ALSO STRATOCUMULUS DECK
ACROSS NORTHERN ALABAMA AND MIDDLE TENNESSEE WILL BE SPREADING
ACROSS OUR SOUTHERN COUNTIES...LOWERED MAX TEMPS 1-2 DEG IN THOSE
AREAS. KEEPING SWRN COUNTIES DRY WITH THIS UPDATE FOR THIS
AFTERNOON. DON`T THINK SHOWERS IN MISSISSIPPI WILL MAKE IN FIRST
PERIOD...AND HRRR HAS THEM FADING ANYWAY. ALSO...MODEL SOUNDINGS
DON`T LOOK FAVORABLE FOR CONVECTIVE DEVELOPMENT...COOLER SURFACE
UNDER CLOUD COVER AND DRIER AIR ALOFT THAT WOULD GET ENTRAINED.
WILL KEEP LIGHT POPS IN EXTREME SE COUNTIES FOR NOW DUE TO POSSIBLE
EXTRA OROGRAPHIC LIFT THERE.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 84 68 87 67 / 10 10 10 20
KNOXVILLE MCGHEE TYSON AIRPORT, TN 84 65 86 65 / 10 10 10 20
OAK RIDGE, TN 85 63 86 64 / 10 0 10 20
TRI CITIES AIRPORT, TN 84 59 84 61 / 10 0 10 10
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
GM
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
935 AM CDT FRI AUG 21 2015
.UPDATE...
EARLY MORNING SHOWERS AND THUNDERSTORMS OVER THE COASTAL AREAS HAS
SENT AN OUTFLOW THAT GENERATED SHOWERS AND THUNDERSTORMS OVER THE
EASTERN PARTS OF SOUTH CENTRAL TEXAS. HAVE BOOSTED POPS 10 TO 20
PERCENT ACROSS AREAS EAST OF I-35 TO ACROSS THE AUSTIN AREA INTO
THE NORTHEASTERN HILL COUNTRY. DUE TO CLOUDS AND RAIN LINGERING
INTO THE AFTERNOON DUE TO BEING ON THE EASTERN SIDE OF THE MID TO
UPPER LEVEL SHEAR AXIS...HAVE ALSO LOWERED TEMPERATURES SLIGHTLY.
REMAINDER OF SOUTH CENTRAL TEXAS FORECAST IS ON TRACK.
&&
.PREV DISCUSSION... /ISSUED 650 AM CDT FRI AUG 21 2015/
AVIATION.../12Z TAF CYCLE/
LOWER CIGS HAVE FILLED IN AS EXPECTED THIS MORNING WITH WIDESPREAD
MVFR WITH INTERMINGLED IFR CONDITIONS PRESENT ACROSS CENTRAL TAF
SITES WITH KDRT MVFR AS WELL. AMPLE MOISTURE IN THE LOWER LAYERS WILL
TAKE SOME TIME TO MIX OUT THROUGH 15-17Z WITH A GRADUAL IMPROVEMENT
THROUGH MVFR TO EVENTUAL VFR FALL ALL SITES BY LATE MORNING TO EARLY
AFTERNOON. A COMPLEX OF SHOWERS AND STORMS IS MOVING INLAND NEAR
KVCT BUT WILL LIKELY MISS THE CENTRAL SITES. FEEL MOST SCATTERED
ACTIVITY WILL REMAIN SOUTHEAST OF THE MAIN TERMINALS AND HAVE
REFRAINED FROM VCTS WORDING THIS TAF CYCLE. TRENDS WILL NEED TO BE
MONITORED HOWEVER FOR POSSIBLE INCLUSION ON 18Z CYCLE. SURFACE WINDS
ARE LIGHT AND VARIABLE CURRENTLY BUT WILL PICK UP TO 10-15 KT THIS
AFTN FROM THE SOUTHEAST TO SOUTH DIRECTION.
PREV DISCUSSION... /ISSUED 333 AM CDT FRI AUG 21 2015/
SHORT TERM (TODAY THROUGH SATURDAY)...
A N-S ORIENTED SHEAR AXIS MOST NOTABLE IN THE MID LEVELS OVER S TX
AND ADJACENT AREAS OF NERN MEXICO SHOULD BRING ANOTHER DAY OF
CONVECTION AND MODERATED DAYTIME TEMPERATURES FOR THE EASTERN
HALF OF SOUTH CENTRAL TX. WHILE THE FRONTAL ZONE THAT BROUGHT WELL
BELOW NORMAL MAX TEMPS TO THE AREA THURSDAY HAS RETREATED
NORTH...SOME COASTAL TROUGHING IS STILL NOTED NEAR CRP...AND A
SMALL COMPLEX OF STORMS CONFIRMS THE UNSTABLE ENVIRONMENT THAT
COULD SPREAD INLAND LATER THIS MORNING. RAPID REFRESH MODEL RUNS
DEPICT EARLY DESTABILIZATION NEAR AND EAST OF I-35 TODAY...BUT
EARLIER RUNS OF THE HRRR WERE SHOWN TO BE TOO AGGRESSIVE WITH
CONVECTION IN THE PRE-DAWN HOURS. ADDITIONAL MOISTURE AND POSSIBLE
INSTABILITY IS MOVING IN FROM NW FLOW ALOFT FROM WEST TX...BUT
WITH ONLY THE 00Z NSSL WRF MODEL SHOWING AN IMPACT OVER OUR
WESTERN COUNTIES VERSUS SEVERAL THAT DO NOT...WILL STICK WITH THE
CONSENSUS POPS FOR THE SERN TWO-THIRDS OF THE FORECAST AREA.
BLENDED GUIDANCES CONTAIN ARTIFACTS OF EARLIER FORECAST HIGHER
TEMPS...SO OPTED FOR A BLEND OF MAV/MET FOR HIGHS.
MODEL RUN TO RUN TRENDS IN THE EARLY PERIODS SHOW MORE SHEAR THAN
EARLIER RUNS...SO WILL FOLLOW THIS TREND TO KEEP A SLIGHTLY LESS
STABLE PICTURE FOR OUR SOUTHERN/WRN COUNTIES FOR SATURDAY.
INCREASED RIDGING AND DRY AIR ENTRAINMENT FROM THE NORTH SHOULD
PRECLUDE CONVECTION OVER MOST OF SOUTH CENTRAL TEXAS...BUT THE
WESTWARD SHIFTING SHEAR AXIS SHOULD PULL SOME MOISTURE WITH IT TO
BRING A SLIGHT CHANCE OF DAYTIME CONVECTION OVER THE RIO GRANDE
PLAINS. MEANWHILE SOUTHERN PARTS OF THE COASTAL PLAINS LOSE THE
CYCLONIC SHEAR BUT MAINTAIN LOCALLY HIGHER PWAT VALUES FOR ONE
MORE DAY. WILL FAVOR THE GFS BASED GUIDANCE FOR WARMER TEMPS TO
REGAIN CONTROL OVER CENTRAL TX WHERE THE DRIER AND MORE STABLE MID-
LEVEL AIR MOVES IN.
LONG TERM (SATURDAY NIGHT THROUGH THURSDAY)...
THE BRIEF BREAK FROM THE HEAT IS ALL BUT FORGOTTEN BY SUNDAY. THE
GFS AND ECMWF BOTH BUILD A STRONG RIDGE OVER THE SOUTHERN ROCKIES
WITH AN AXIS THAT EXTENDS SE ACROSS CENTRAL TX. WILL SHADE TOWARD
THE HIGHER MEX GUIDANCE ON MAXES SUNDAY THROUGH WEDNESDAY AS
AUGUST RAINS HAVE BEEN MOSTLY TOO SPARSE TO PROVIDE FEEDBACK
THROUGH SOIL AND VEGETATION. LATE MONDAY THROUGH DAYTIME
WEDNESDAY...THERE IS A SIGNAL FOR MID-LEVEL MOISTURE POOLING TO
SPREAD SOUTH FROM NORTH TX AS NORTHERLY FLOW INCREASES ALOFT. THUS
WILL SHADE TOWARD THE SLIGHTLY MORE UNSTABLE ECMWF OVER THE
SLIGHTLY DRIER GFS FOR THOSE DAYS. LITTLE OR NO CONVECTION IS
SHOWN BY EITHER MODEL FOR THE REMAINDER OF NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 91 76 98 77 99 / 40 10 10 - -
AUSTIN BERGSTROM INTL AIRPORT 92 73 97 75 98 / 40 10 10 - -
NEW BRAUNFELS MUNI AIRPORT 92 75 98 76 98 / 30 10 10 - -
BURNET MUNI AIRPORT 92 74 97 75 98 / 20 10 10 - -
DEL RIO INTL AIRPORT 96 76 98 78 99 / 10 - 20 - -
GEORGETOWN MUNI AIRPORT 92 76 96 76 98 / 40 10 10 - 10
HONDO MUNI AIRPORT 95 74 96 75 97 / 20 10 10 - -
SAN MARCOS MUNI AIRPORT 92 75 98 76 99 / 30 10 10 - -
LA GRANGE - FAYETTE REGIONAL 91 76 96 76 98 / 50 20 20 10 10
SAN ANTONIO INTL AIRPORT 93 76 97 77 98 / 30 10 10 - -
STINSON MUNI AIRPORT 93 76 98 77 99 / 30 20 10 - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...TREADWAY
SYNOPTIC/GRIDS...04
PUBLIC SERVICE/DATA COLLECTION...10
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
655 AM CDT FRI AUG 21 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 318 AM CDT FRI AUG 21 2015
MOST OF THE FORECAST TIME THIS MORNING WAS ENSURING WE WERE ON TRACK
WITH RAIN CHANCES IN THE RETURN FLOW TODAY....CLOUDS ON
SATURDAY...BUT MAINLY THE SATURDAY NIGHT THUNDERSTORM THREATS AND
ANY MESSAGING THAT WILL BE NEEDED FOR THOSE OUTDOORS.
CURRENT OBSERVATIONAL DATA AS OF 21.07Z INDICATES NW-SE ORIENTED
CLOUD BANDING AROUND 10KFT ACROSS CENTRAL MN ASSOCIATED WITH
FRONTOGENESIS IN THE 800-900 MB LAYER PER LATEST RAP ANALYSIS.
TSRA AND LIGHTNING IN NWRN IA ON THE NOSE OF THE LOW-LEVEL JET PER
88D VWPS AND RAP ANALYSIS. SPC MESOANALYSIS SHOWING THAT TSRA IS
ON THE NORTHERN EXTENT OF THE MUCAPE REGION /ONLY ABOUT 250 J/KG
THERE/.
GOES FOG PRODUCT AND SURFACE OBSERVATIONS SHOW A LOWER CLOUD FIELD
OVER OK/TX SOUTH IN A RICH MOIST POOL OF SURFACE DEWPOINTS OVER
65F...AND 925MB DEWPOINTS AT 18C PER 21.00Z RAOBS. WILL HAVE TO
WATCH THIS AREA AS IT ADVECTS NORTHWARD AHEAD OF THE FRONT THAT IS
MOVING IN FOR SATURDAY NIGHT...ASSOCIATED WITH THE SHORTWAVE
TROUGH NOW WORKING SOUTHWARD THROUGH BRITISH COLUMBIA /PER GOES
WATER VAPOR/. RAP ANALYSIS INDICATES THIS SPINNER HAS A TROPOPAUSE
FOLD DOWN TO ROUGHLY 750 MB...SO A POTENT VORTEX.
SHORT TERM GUIDANCE SUPPORTS EVOLVING THE FRONTOGENESIS AND THE
LOW-LEVEL JET NOSE CONVERGENCE NORTHEAST THROUGH THE FIRST PORTION
OF TODAY INTO NRN WI BY AFTERNOON. THERE WILL LIKELY BE VERY LIGHT
RADAR RETURNS AND PER 00Z RAOB DATA...SOME PRETTY DRY AIR TO
OVERCOME BELOW THE ACCAS CLOUD BASE /10KFT/. FOR NOW...HAVE KEPT
THE HIGHER PROBABILITY DRY FORECAST. SPRINKLES OR AN ISOLATED
WETTING SHOWER MAY BE POSSIBLE WITH FORCING EVOLUTION NEWRD.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 318 AM CDT FRI AUG 21 2015
NO BIG CHANGES DURING THIS PERIOD.
SOUTHWESTERLY FLOW WILL PREVAIL SATURDAY AND PRE-FRONTALLY WILL
NEED TO WATCH THE SURGE OF 925 MB MOISTURE NORTHWARD TONIGHT.
CONSENSUS 21.00Z GUIDANCE SUGGESTS THIS TONGUE REMAINS WEST OF THE
AREA UNTIL FRONT ARRIVES SAT EVENING. HAVE INCREASED WIND GUSTS
SATURDAY WITH STRONGER LOW-LEVEL WIND FIELD SUGGESTED AND MIXING
DEPTH INTO THE 35-38KT CONSENSUS 900MB WINDS.
TIMING IS ABOUT THE SAME AS PREVIOUS FORECASTS FOR FRONT TO
BECOME ACTIVE TO THE WEST OF THE AREA LATER SATURDAY. THIS FRONT
IS ASSOCIATED WITH THE BRITISH COLUMBIA SHORTWAVE AS IT DIGS
SOUTHEAST INTO CENTRAL MN...THEN EJECTS NORTHEAST OVER DULUTH.
THUS...THE AREA ISNT DIRECTLY HIT BY THE MID-UPPER TROPOSPHERIC
FORCING...WHICH FAVORS BETTER CONVECTION TO EJECT NORTHEAST...BUT
BROAD ASCENT FROM LARGE SCALE FORCING IS OVER THE AREA. THE CAPE
AXIS IS VERY NARROW...RIGHT ALONG THE FRONT...WITH A STOUT CAP OUT
AHEAD SUGGESTED. MUCAPE HAS REMARKABLE DROP SUGGESTED IN THE
MODEL GUIDANCE FROM 7PM TO 1 AM...ABOUT 2500 IN PEAK HEATING WEST
OF THE FORECAST AREA...TO ABOUT 750 J/KG BY 1 AM ON THE MISS
RIVER. THE WESTERN FORECAST AREAS OF NERN IA AND SERN MN HAVE THE
MOST POTENTIAL FOR SEVERE STORMS FOR A SMALL WINDOW SATURDAY
EVENING AS THE STORMS WEAKEN HEADING EAST. SPC DAY 2 RISK HAS
SHIFTED THE SLIGHT RISK EAST INTO THAT AREA...BUT NOT TOO MUCH HAS
CHANGED. MODEST 0-3KM WIND SHEAR WOULD FAVOR LINE SEGMENTS
PROMOTING DAMAGING WINDS. THE 0-3KM SHEAR VECTOR IS ALIGNED
PERPENDICULAR TO THE FRONT OR CONVECTIVE LINE...PROMOTING BETTER
COLD POOL MAINTENANCE.
SEVERE THREAT DEPENDS ON TIMING OF THE FRONT AND STORMS. ARRIVAL
IN THE EARLY EVENING WOULD FAVOR HIGHER SEVERE STORM CHANCES PER
HIGHER CAPE IN MODEST LOW-LEVEL SHEAR. CONSENSUS MODEL GUIDANCE IS
A MID-LATER EVENING APPROACH OF STORMS IN NERN IA AND SERN MN
WITH STORMS JUST PAST PEAK AND INTO WEAKENING STAGE...WITH COLD
POOLS THAT COULD PROBABLY PRODUCE ISOLATED WIND DAMAGE. WILL TAKE
A SLIGHT STEP UP IN MESSAGING MOVING TO STRONG TO ISOLATED SEVERE
STORMS.
A COOL FIRST HALF OF THE WEEK IN NORTHWEST FLOW WITH DRIER
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 650 AM CDT FRI AUG 21 2015
WARM AIR ADVECTION AND SOME MOISTURE TRANSPORT WILL CONTINUE TO
PRODUCE A SCATTERED TO BROKEN MID DECK OF CLOUDS ACROSS THE AREA
TODAY...AND THEN SKIES WILL CLEAR. WITH DIURNAL MIXING TODAY...
THE SUSTAINED SOUTH WINDS WILL CLIMB INTO THE 10 TO 20 KNOTS...
AND THE WINDS WILL GUST INTO THE 20 TO 30 KNOT RANGE. THE WINDS
WILL THEN SUBSIDE QUICKLY THIS EVENING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...BOYNE
AREA FORECAST DISCUSSION...UPDATE
NWS PHOENIX AZ
1020 AM MST FRI AUG 21 2015
.UPDATE...
AVIATION DISCUSSION.
&&
.SYNOPSIS...
THUNDERSTORMS WILL GENERALLY REMAIN CONFINED TO THE HIGHER TERRAIN
OF SOUTHERN AND EASTERN ARIZONA THROUGH THE WEEKEND. HIGH PRESSURE
WILL SETTLE ACROSS THE FOUR CORNERS MONDAY...RESULTING IN BETTER
RAIN CHANCES ACROSS THE LOWER DESERTS. DRIER CONDITIONS WILL RETURN
BY MIDWEEK ALONG WITH NEAR TO ABOVE NORMAL TEMPERATURES.
&&
.DISCUSSION...
A SHEARING SHORTWAVE WAS STILL EVIDENT OVER FAR SERN ARIZONA/SW NEW
MEXICO ON MORNING WV IMAGERY...WITH FLOW OTHERWISE BACKING TO WLY IN
THE MIDLEVELS THROUGH THE FORECAST AREA. RATHER EXTENSIVE ACCAS
CONTINUED TO PERCOLATE FROM ERN PIMA THROUGH GILA COUNTY IN
ASSOCIATION WITH A SLUG OF MOISTURE IN THE H8-H7 LAYER TRAPPED BELOW
A WEAK ELEVATED CAPPED LAYER. HOWEVER...THE MOST NOTABLE FEATURES IN
12Z SOUNDING DATA IS RICH MOISTURE AVAILABILITY IN THE BOUNDARY
LAYER WITH KPSR DATA MEASURING 11-12 G/KG IN THE SFC-H7 LAYER...AND
KTWC SAMPLING AN IMPRESSIVE 14-15 G/KG IN A SFC-750MB LAYER.
AS A RESULT...LATEST MESOANALYSIS ESTIMATES MLCAPES IN THE SERN
QUARTER OF ARIZONA ALREADY ECLIPSING THE 1500-2000 J/KG
RANGE...ALBEIT WITH CINH STILL PRESENT. DESPITE THESE EXCESSIVE
LEVELS OF INSTABILITY...THERE IS LITTLE TO NOTHING EVIDENT IN
SATELLITE IMAGERY THAT COULD BE TERMED AS A LIFTING MECHANISM...AND
THE FACT THAT THE ACCAS TURRETS HAVE NOT EXPERIENCED UPSCALE GROWTH
SUGGEST LARGER SCALE SUBSIDENCE STILL PREDOMINATES ACROSS THE
REGION. THEREFORE...WITH STILL ONLY LIMITED SUPPORT FOR HIGH
RESOLUTION ENSEMBLE DATA...MADE VERY LITTLE CHANGE TO POPS THE
REMAINDER OF THE DAY. HOWEVER...AM STILL CONCERNED DESPITE THE LOWER
CONFIDENCE GIVEN THE POTENTIAL LARGE IMPACTS GIVEN THE HIGH
INSTABILITY VALUES. WILL CONTINUE TO EVALUATE CONVECTIVE POTENTIAL
AND COVERAGE THROUGH THE AFTERNOON.
&&
.PREVIOUS DISCUSSION...
/502 AM MST FRI AUG 21 2015/
AN ANTICYCLONE IN THE MID AND UPPER LEVELS REMAINS POSITIONED OFF
THE BAJA PENINSULA...RESULTING IN A WESTERLY COMPONENT TO THE FLOW.
AT THE SURFACE...YUMA VWP SUGGESTS THAT A SHALLOW GULF SURGE IS
TAKING PLACE ACROSS SOUTHWESTERN AZ. DEWPOINTS NEAR YUMA AND ACROSS
THE IMPERIAL VALLEY HAVE RESPONDED...INCREASING INTO THE MID TO UPPER
70S EARLY THIS MORNING. FURTHER EAST ACROSS THE LOWER DESERTS OF
SOUTH-CENTRAL AZ...AN INFLUX OF MOISTURE IS ALSO ANTICIPATED THIS
MORNING...BUT TO A LESSER DEGREE.
SOME EARLIER WRF-BASED GUIDANCE INDICATED THAT SHOWERS AND
THUNDERSTORMS WOULD DEVELOP THIS MORNING ACROSS PORTIONS OF THE
LOWER DESERTS. HOWEVER...THE LATEST LOCAL WRFS AND U OF ARIZONA WRFS
HAVE BACKED OFF CONSIDERABLY AND DEPICT CONVECTION BEING MOST
CONCENTRATED ACROSS THE HIGHER TERRAIN SOUTH AND EAST OF PHOENIX THIS
AFTERNOON. SEVERAL RUNS OF THE HRRR HAVE ALSO DISMISSED THE
POSSIBILITY OF CONVECTION STARTING EARLY THIS MORNING...THOUGH CAPES
ABOVE 1000 J/KG SHOULD CERTAINLY SUPPORT DEVELOPMENT BY EARLY
AFTERNOON. LACK OF A TRIGGER IN THE UPPER LEVELS ALONG WITH WEAK
WESTERLY FLOW POINT TO TERRAIN- BASED CONVERGENCE AS THE PRIMARY
LIFTING MECHANISM. NEVERTHELESS...THERE IS A SLIGHT CHANCE OF
THUNDERSTORMS IN THE PHOENIX AREA...THOUGH THE GREATER LIKELIHOOD IS
FOR AREAS OF BLOWING DUST.
MEAN FLOW WILL BECOME MORE WESTERLY SATURDAY AS THE ANTICYCLONE
DRIFTS NORTHWARD. THIS WILL AGAIN CONFINE THUNDERSTORMS MAINLY TO THE
HIGHER TERRAIN EAST OF PHOENIX. MORE OF THE SAME FOR SUNDAY AS THE
HIGH DRIFTS OVERHEAD.
CONDITIONS WILL BECOME SOMEWHAT MORE FAVORABLE FOR PRECIPITATION
EARLY NEXT WEEK AS THE MONSOON HIGH BECOMES REESTABLISHED ACROSS THE
FOUR CORNERS. INCREASING EASTERLY COMPONENT TO THE FLOW GENERALLY
FAVORS HIGHER CHANCES OF THUNDERSTORMS. HOWEVER...MODEL CROSS
SECTIONS INDICATE THAT ABUNDANT MOISTURE IN THE MID AND UPPER LEVELS
MAY RESULT IN CONSIDERABLE CLOUDINESS AND ULTIMATELY A DECREASE IN
INSTABILITY AND THE POTENTIAL FOR THUNDERSTORMS ACROSS THE AREA.
OPERATIONAL GFS AND ECMWF ALSO SUGGEST THE PRESENCE OF AN INVERTED
TROUGH ACROSS NORTHERN SONORA...THOUGH DIFFERENCES IN THE STRENGTH
AND TIMING OF THIS FEATURE ARE APPARENT.
GENERAL CONSENSUS AMONG THE MODELS FOR NEXT WEEK IS THAT THE MONSOON
HIGH WILL DRIFT EASTWARD AND SOUTHWARD. FLOW WILL GRADUALLY BECOME
SOUTHWESTERLY AGAIN...FAVORING THE HIGHER TERRAIN FOR CONVECTION.
TEMPERATURES AT OR ABOVE NORMAL ARE EXPECTED THROUGH THE EXTENDED.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL
A RATHER MESSY EASTERLY FLOW ACROSS THE PHX AREA CONTINUES LATE THIS
MORNING. FULLY EXPECT WESTERLY FLOW TO DEVELOP OVER THE NEXT FEW
HOURS...APPEARING NOT AS STRONG/GUSTY AS EARLIER. ONE THING TO WATCH
IS A FEW THUNDERSHOWERS WELL E OF THE PHX AREA. ATMOSPHERE DOES HAVE
A DECENT AMOUNT OF INSTABILITY TODAY BUT NO CLEAR MECHANISM TO
RELEASE IT. SHOULD STORMS OVER SE AZ DEVELOP BETTER THROUGH THE
DAY...MAY CONTEND WITH NEARBY TS AND OUTFLOW FOR PHX AREA TERMINALS.
MOST LIKELY OUTCOME IS A SUNNY AND QUIET DAY.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
TYPICAL DIURNAL WIND PATTERNS WITH CLEAR SKIES THROUGH AT LEAST 00Z
SUNDAY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
MONSOON MOISTURE LEVELS AND HUMIDITIES WILL PERSIST THROUGH MIDWEEK.
STORM CHANCES WILL CONTINUE FOR THE HIGHER TERRAIN LOCALES FOR
SUNDAY BEFORE EXPANDING INTO THE LOWER DESERT ELEVATIONS BY THE
EARLY WORK WEEK AS SOME UPPER LEVEL DISTURBANCES PASS THROUGH THE
AREA AND SUPPORT THE POTENTIAL FOR MORE WIDESPREAD STORM
DEVELOPMENT. DAYTIME HUMIDITIES WILL RANGE FROM THE 20 TO 30 PERCENT
RANGE WHILE MAKING GOOD OVERNIGHT RECOVERIES. OUTSIDE OF
THUNDERSTORM OUTFLOW AND VICINITY WINDS...SFC WINDS TO MAINTAIN
DAYTIME HEADINGS 10 TO 20 MPH WHILE BECOMING DOWN DRAINAGE/DOWN
VALLEY IN THE OVERNIGHTS. A SLIGHT DRAW DOWN OF MONSOON MOISTURE AND
INTRUSION OF WESTERLY FLOW ALOFT WILL RELEGATE STORM CHANCES BACK
ACROSS EASTERN AZ FOR THE LATTER PART OF THE WEEK...WHILE
TEMPERATURES ALSO BEGIN TO WARM TO ABOVE NORMAL VALUES.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...MO/HIRSCH
AVIATION...NOLTE
FIRE WEATHER...NOLTE
AREA FORECAST DISCUSSION
NWS TUCSON AZ
1004 AM MST FRI AUG 21 2015
.SYNOPSIS...SHOWER AND THUNDERSTORM CHANCES WILL CONTINUE TO
INCREASE THROUGH THE COMING WEEKEND WITH A MORE TYPICAL MONSOON
PATTERN EXPECTED INTO EARLY NEXT WEEK. THE INCREASED MOISTURE WILL
ALSO KEEP DAYTIME TEMPERATURES CLOSER TO SEASONAL AVERAGES FRIDAY
INTO EARLY NEXT WEEK.
&&
.DISCUSSION...THE TUCSON MORNING UPPER-AIR SOUNDING INDICATED A
RATHER MOIST AND UNSTABLE AIRMASS IN PLACE ACROSS THE AREA. IN
FACT...A FEW SHOWERS AND THUNDERSTORMS WERE ALREADY REDEVELOPING IN
COCHISE COUNTY AS OF 10 AM MST. LATEST HRRR SOLUTIONS SUGGESTED
ANOTHER ACTIVE THUNDERSTORM DAY INSTORE FOR SOUTHEAST ARIZONA TODAY.
RAIN CHANCES IN THE CURRENT FORECAST STILL LOOKED ON TRACK...SO NO
PLANS TO UPDATE THE FORECAST AT THIS TIME. PLEASE REFER THE
ADDITIONAL SECTIONS FOR MORE DETAILS.
&&
.AVIATION...VALID THRU 22/18Z.
SKC-FEW HIGH CIRRUS CLOUDS AT 20-25K FT...THEN SCT-BKN CLOUDS AT 7-
11K FT AGL REDEVELOPING THIS AFTERNOON...ALONG WITH ISOLATED TO
SCATTERED SHRA/TSRA. BRIEF MVFR CONDITIONS...ALONG WITH STRONG GUSTY
WINDS POSSIBLE IN AN AROUND SHRA/TSRA. OTHERWISE...WINDS WILL
GENERALLY BE LIGHT AND TERRAIN DRIVEN. AVIATION DISCUSSION NOT
UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...MOISTURE WILL CONTINUE TO INCREASE WITH ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS EXPECTED THIS AFTERNOON AND
EVENING WITH AN EMPHASIS ON AREAS FROM TUCSON AND POINTS EASTWARD.
THEREAFTER...MOISTURE AND THUNDERSTORMS CHANCES WILL INCREASE AND
SPREAD THROUGHOUT SOUTHEAST ARIZONA THROUGH THE WEEKEND INTO EARLY
NEXT WEEK. EXPECT A DECREASE IN SHOWER AND THUNDERSTORMS DURING THE
MIDDLE TO LATTER PART OF NEXT WEEK. WINDS WILL BE TYPICAL FOR MID
AUGUST AND GENERALLY LESS THAN 15 MPH WITH AFTERNOON GUSTINESS...
ESPECIALLY IN THE GILA RIVER VALLEY.
&&
.PREV DISCUSSION...THERE IS A VERY WEAK FEATURE OVER NORTHERN BAJA
THAT SHOULD MOVE SLOWLY EASTWARD AND POTENTIALLY HELP OUT ALONG OR
SOUTH OF THE BORDER LATE TODAY BUT IT IS MUCH LESS SIGNIFICANT THAN
WHAT HELPED YESTERDAYS CONVECTION. SO OVERALL WITH THE INSTABILITY
AND MOISTURE THAT WE HAVE WOULD EXPECT CONVECTION TO FIRE UP OVER
HIGHER TERRAIN EARLY THIS AFTERNOON ACROSS THE EASTERN TWO THIRDS OF
THE AREA THEN SPREAD FROM THERE DUE TO OUTFLOWS. WHAT WILL BE
INTERESTING IS STORM MOTION AS THE UPPER LEVEL WINDS ARE LIGHTER
THAN YESTERDAY SO STORM MOTION WILL BE SLOWER AND LIKELY A BIT TO
THE EAST ALTHOUGH OUTFLOWS WILL LIKELY DRIVE THE MOVEMENT OF SOME
STORMS IN THIS LIGHT FLOW. WITH 102 AS A HIGH THURSDAY I WENT AHEAD
AND BUMPED TODAYS TEMPS A DEGREE OR TWO FROM WHAT WAS IN THERE. IF
THE CONVECTION IS SLOWER TO DEVELOP WILL LIKELY BE A BIT HIGHER YET.
ON SATURDAY THE UPPER HIGH NOW JUST TO OUR SW WILL BE MOVING EAST
ACROSS THE AREA THROUGH THE DAY. WILL STILL HAVE A GOOD AMOUNT OF
MOISTURE HOWEVER MID LEVEL TEMPS WILL BE A BIT WARMER FOR LESS
INSTABILITY. SHOULD STILL SEE CONVECTION DEVELOP JUST NOT EXPECTING
AN ABUNDANCE OF IT AND WILL LIKELY BE FOCUSED ON THE TERRAIN FROM
TUCSON EASTWARD.
IT POTENTIALLY BECOMES A BIT MORE INTERESTING AFTER THAT AS THE HIGH
CONTINUES EAST TO NEW MEXICO/TEXAS BY SUNDAY. GUIDANCE CONTINUES TO
SHOW A DISTURBANCE OVER MEXICO MOVING WNW ACROSS THE AREA SUNDAY
INTO MONDAY. VARIOUS MODELS DIFFER ON THE TIMING WITH THE GFS BEING
THE QUICKER OF THE BUNCH ON THE LATEST RUN. WHEN THIS DOES PASS IT
SHOULD RAMP UP THE CONVECTION AND AT THIS TIME THE MOST LIKELY TIME
WOULD BE LATE SUNDAY INTO MONDAY. I RAISED POPS A BIT THROUGH THIS
TIME FRAME TO TRY TO CAPTURE THIS BUT WE WILL NEED TO KEEP AN EYE ON
THIS AS THE TIME APPROACHES FOR MORE DETAILS AS THE BULK OF IT COULD
SLIDE BY JUST TO OUR SOUTH DEPENDING ON THE LOCATION OF THE
EAST/WEST RIDGE AXIS. SUNDAY AND MONDAY LIKELY THE COOLEST DAYS OF
THE FORECAST PERIOD WITH HIGHS A BIT BELOW NORMAL.
TUESDAY AND WEDNESDAY THE UPPER HIGH IS IN A PRETTY GOOD POSITION
FOR CONVECTIVE ACTIVITY OVER THE CWA AND HAVE LEFT THE POPS AS THEY
WERE WHICH IS ABOUT 5-10 POINTS ABOVE CLIMO. WITH A BIT MORE
SUNSHINE BUMPED TEMPS BACK UP A BIT. SHOULD BE ABLE TO ADD A FEW
MORE 100+ DEGREE DAYS TO THE TALLY FOR TUCSON.
THURSDAY ONWARD THE UPPER HIGH IS PROGGED TO SLIDE RIGHT OVER THE
AREA WHICH WOULD ACT TO SHUT OFF THE MOISTURE FLOW AND SUPPRESS
CONVECTION WHILE ALSO ALLOWING FOR ABOVE NORMAL TEMPERATURES.
TWEAKED THE GRIDS WITH THAT IN MIND...SLIGHTLY DRIER AND WARMER.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
945 AM MST FRI AUG 21 2015
.SYNOPSIS...
THUNDERSTORMS WILL GENERALLY REMAIN CONFINED TO THE HIGHER TERRAIN
OF SOUTHERN AND EASTERN ARIZONA THROUGH THE WEEKEND. HIGH PRESSURE
WILL SETTLE ACROSS THE FOUR CORNERS MONDAY...RESULTING IN BETTER
RAIN CHANCES ACROSS THE LOWER DESERTS. DRIER CONDITIONS WILL RETURN
BY MIDWEEK ALONG WITH NEAR TO ABOVE NORMAL TEMPERATURES.
&&
.DISCUSSION...
A SHEARING SHORTWAVE WAS STILL EVIDENT OVER FAR SERN ARIZONA/SW NEW
MEXICO ON MORNING WV IMAGERY...WITH FLOW OTHERWISE BACKING TO WLY IN
THE MIDLEVELS THROUGH THE FORECAST AREA. RATHER EXTENSIVE ACCAS
CONTINUED TO PERCOLATE FROM ERN PIMA THROUGH GILA COUNTY IN
ASSOCIATION WITH A SLUG OF MOISTURE IN THE H8-H7 LAYER TRAPPED BELOW
A WEAK ELEVATED CAPPED LAYER. HOWEVER...THE MOST NOTABLE FEATURES IN
12Z SOUNDING DATA IS RICH MOISTURE AVAILABILITY IN THE BOUNDARY
LAYER WITH KPSR DATA MEASURING 11-12 G/KG IN THE SFC-H7 LAYER...AND
KTWC SAMPLING AN IMPRESSIVE 14-15 G/KG IN A SFC-750MB LAYER.
AS A RESULT...LATEST MESOANALYSIS ESTIMATES MLCAPES IN THE SERN
QUARTER OF ARIZONA ALREADY ECLIPSING THE 1500-2000 J/KG
RANGE...ALBEIT WITH CINH STILL PRESENT. DESPITE THESE EXCESSIVE
LEVELS OF INSTABILITY...THERE IS LITTLE TO NOTHING EVIDENT IN
SATELLITE IMAGERY THAT COULD BE TERMED AS A LIFTING MECHANISM...AND
THE FACT THAT THE ACCAS TURRETS HAVE NOT EXPERIENCED UPSCALE GROWTH
SUGGEST LARGER SCALE SUBSIDENCE STILL PREDOMINATES ACROSS THE
REGION. THEREFORE...WITH STILL ONLY LIMITED SUPPORT FOR HIGH
RESOLUTION ENSEMBLE DATA...MADE VERY LITTLE CHANGE TO POPS THE
REMAINDER OF THE DAY. HOWEVER...AM STILL CONCERNED DESPITE THE LOWER
CONFIDENCE GIVEN THE POTENTIAL LARGE IMPACTS GIVEN THE HIGH
INSTABILITY VALUES. WILL CONTINUE TO EVALUATE CONVECTIVE POTENTIAL
AND COVERAGE THROUGH THE AFTERNOON.
&&
.PREVIOUS DISCUSSION...
/502 AM MST FRI AUG 21 2015/
AN ANTICYCLONE IN THE MID AND UPPER LEVELS REMAINS POSITIONED OFF
THE BAJA PENINSULA...RESULTING IN A WESTERLY COMPONENT TO THE FLOW.
AT THE SURFACE...YUMA VWP SUGGESTS THAT A SHALLOW GULF SURGE IS
TAKING PLACE ACROSS SOUTHWESTERN AZ. DEWPOINTS NEAR YUMA AND ACROSS
THE IMPERIAL VALLEY HAVE RESPONDED...INCREASING INTO THE MID TO UPPER
70S EARLY THIS MORNING. FURTHER EAST ACROSS THE LOWER DESERTS OF
SOUTH-CENTRAL AZ...AN INFLUX OF MOISTURE IS ALSO ANTICIPATED THIS
MORNING...BUT TO A LESSER DEGREE.
SOME EARLIER WRF-BASED GUIDANCE INDICATED THAT SHOWERS AND
THUNDERSTORMS WOULD DEVELOP THIS MORNING ACROSS PORTIONS OF THE
LOWER DESERTS. HOWEVER...THE LATEST LOCAL WRFS AND U OF ARIZONA WRFS
HAVE BACKED OFF CONSIDERABLY AND DEPICT CONVECTION BEING MOST
CONCENTRATED ACROSS THE HIGHER TERRAIN SOUTH AND EAST OF PHOENIX THIS
AFTERNOON. SEVERAL RUNS OF THE HRRR HAVE ALSO DISMISSED THE
POSSIBILITY OF CONVECTION STARTING EARLY THIS MORNING...THOUGH CAPES
ABOVE 1000 J/KG SHOULD CERTAINLY SUPPORT DEVELOPMENT BY EARLY
AFTERNOON. LACK OF A TRIGGER IN THE UPPER LEVELS ALONG WITH WEAK
WESTERLY FLOW POINT TO TERRAIN- BASED CONVERGENCE AS THE PRIMARY
LIFTING MECHANISM. NEVERTHELESS...THERE IS A SLIGHT CHANCE OF
THUNDERSTORMS IN THE PHOENIX AREA...THOUGH THE GREATER LIKELIHOOD IS
FOR AREAS OF BLOWING DUST.
MEAN FLOW WILL BECOME MORE WESTERLY SATURDAY AS THE ANTICYCLONE
DRIFTS NORTHWARD. THIS WILL AGAIN CONFINE THUNDERSTORMS MAINLY TO THE
HIGHER TERRAIN EAST OF PHOENIX. MORE OF THE SAME FOR SUNDAY AS THE
HIGH DRIFTS OVERHEAD.
CONDITIONS WILL BECOME SOMEWHAT MORE FAVORABLE FOR PRECIPITATION
EARLY NEXT WEEK AS THE MONSOON HIGH BECOMES REESTABLISHED ACROSS THE
FOUR CORNERS. INCREASING EASTERLY COMPONENT TO THE FLOW GENERALLY
FAVORS HIGHER CHANCES OF THUNDERSTORMS. HOWEVER...MODEL CROSS
SECTIONS INDICATE THAT ABUNDANT MOISTURE IN THE MID AND UPPER LEVELS
MAY RESULT IN CONSIDERABLE CLOUDINESS AND ULTIMATELY A DECREASE IN
INSTABILITY AND THE POTENTIAL FOR THUNDERSTORMS ACROSS THE AREA.
OPERATIONAL GFS AND ECMWF ALSO SUGGEST THE PRESENCE OF AN INVERTED
TROUGH ACROSS NORTHERN SONORA...THOUGH DIFFERENCES IN THE STRENGTH
AND TIMING OF THIS FEATURE ARE APPARENT.
GENERAL CONSENSUS AMONG THE MODELS FOR NEXT WEEK IS THAT THE MONSOON
HIGH WILL DRIFT EASTWARD AND SOUTHWARD. FLOW WILL GRADUALLY BECOME
SOUTHWESTERLY AGAIN...FAVORING THE HIGHER TERRAIN FOR CONVECTION.
TEMPERATURES AT OR ABOVE NORMAL ARE EXPECTED THROUGH THE EXTENDED.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL AND
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
EARLY AM SCT-BKN CLOUDS BETWEEN PHX AND CGZ WILL SETTLE OUT TO FEW-
SCT MID-LEVEL CLOUDS FOR THE AFTN...WITH SKIES REMAINING MOSTLY
CLEAR FOR THE WESTERN TERMINALS OF BLH AND IPL. S-SE AM WINDS TO
PREVAIL FOR THE TERMINALS SAVE FOR KPHX...WHICH WILL MAINTAIN SUBTLE
W-NW HEADINGS WITH PERIODS OF VRB. AFTN WINDS TO BECOME S-SW FOR THE
PHX AREA TERMINALS...WITH PERIODS OF 20KT GUSTINESS. ISO TS SHOULD
FORM WELL EAST AND SOUTH OF THE PHX AREA...WITH VERY REMOTE CHANCES
OF OUTFLOW RELATED IMPACTS INTO KIWA DURING THE EVENING.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
MONSOON MOISTURE LEVELS AND HUMIDITIES WILL PERSIST THROUGH MIDWEEK.
STORM CHANCES WILL CONTINUE FOR THE HIGHER TERRAIN LOCALES FOR
SUNDAY BEFORE EXPANDING INTO THE LOWER DESERT ELEVATIONS BY THE
EARLY WORK WEEK AS SOME UPPER LEVEL DISTURBANCES PASS THROUGH THE
AREA AND SUPPORT THE POTENTIAL FOR MORE WIDESPREAD STORM
DEVELOPMENT. DAYTIME HUMIDITIES WILL RANGE FROM THE 20 TO 30 PERCENT
RANGE WHILE MAKING GOOD OVERNIGHT RECOVERIES. OUTSIDE OF
THUNDERSTORM OUTFLOW AND VICINITY WINDS...SFC WINDS TO MAINTAIN
DAYTIME HEADINGS 10 TO 20 MPH WHILE BECOMING DOWN DRAINAGE/DOWN
VALLEY IN THE OVERNIGHTS. A SLIGHT DRAW DOWN OF MONSOON MOISTURE AND
INTRUSION OF WESTERLY FLOW ALOFT WILL RELEGATE STORM CHANCES BACK
ACROSS EASTERN AZ FOR THE LATTER PART OF THE WEEK...WHILE
TEMPERATURES ALSO BEGIN TO WARM TO ABOVE NORMAL VALUES.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...MO/HIRSCH
AVIATION...NOLTE
FIRE WEATHER...NOLTE
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
908 AM PDT FRI AUG 21 2015
.Synopsis... Dry weather with near normal temperatures through
early next week. Hazy/smoky conditions will continue in portions
of NorCal.
&&
.Short Term Discussion (Today through Monday)...
The Delta Breeze is still healthy early this morning some stratus
that formed over northeastern Sacramento county, but it won`t last
very long. The short term forecast into Monday will be reasonable
& seasonable. Daytime highs will generally oscillate within 5
degrees of normal. For areas influenced by the Delta Breeze,
daytime highs will be near to slightly below normal while other
areas will be near to slightly above normal. For today, Valley
highs will range upper 80s (near Delta) to upper 90s (near
Redding) while max temps in higher terrain will range in the 70s
(higher elevations of the Sierra) to the upper 80s/low 90s
(foothill locations). Very subtle warming occurs starting Saturday
as ridging strengthens over NorCal.
The main concern in the short term are the hazy/smoky conditions
due to fires that continue to burn, especially the many fires in
Trinity county. The HRRR model showed that smoke particulates
from the Trinity vicinity could move southward today towards
Sacramento area and then curl around as the Delta Breeze moves
northward up the valley. However, the satellite imagery this
morning indicates less smoke than yesterday, with a swath south
and east of Sacramento area and a west to east plume into Redding.
In any case, some degree of haze will be present over the next
several days.
JBB/JClapp
&&
.Extended Discussion (Tuesday through Friday)
Near normal temperatures on Tuesday will be followed by
temperatures trending down through the rest of the week into the
weekend as a cool trough from the Gulf of Alaska approaches. How
quickly this system moves in is still in doubt, as the 00Z GFS and
ECMWF have essentially traded positions from model runs yesterday,
with the GFS now keeping a closed low off the coast and the ECMWF
bringing a quicker moving trough in on Friday. This would bring
the potential for some precipitation into far northern California
late Friday. While the GFS does keep the main low off the coast,
it does have a weak shortwave on Friday afternoon. Have introduced
just a slight chance of rain showers for the northern Coastal
Range for Friday afternoon. Will be watching to see if later model
runs trend closer together and need to expand this later.
Current Global Ensemble Forecast System (GEFS) ensembles and
analogs are pointing towards a cool down for late in the week.
Highs by Friday may stay in the 80s, even over the northern
Sacramento Valley. Increased cloud cover if the trough moves
inland would be a factor in this. EK
&&
.Aviation...
General VFR conditions expected over the next 24
hours. MVFR with local IFR cigs expected into I-680 until 17-18z,
with bases BKN010-012 in NE Sacramento county before eroding
around 17z. Wildfire smoke may pose slant-range visibility issues.
JClapp
&&
.STO WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
AREA FORECAST DISCUSSION
NWS PUEBLO CO
300 PM MDT FRI AUG 21 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 300 PM MDT FRI AUG 21 2015
TRAILING SOUTHERN END OF A SHORTWAVE MOVING THROUGH WESTERLY FLOW
ALOFT ACROSS WY AND NE CO HAS TRIGGERED THUNDERSTORMS ALONG THE SFC
TROF AXIS ACROSS EASTERN CO. MEANWHILE...REMNANT MOISTURE CAUGHT
WITHIN THE FLAT UPPER RIDGE ACROSS SOUTHWEST CO HAS TRIGGERED
THUNDERSTORMS ACROSS THE EASTERN SAN JUANS. THESE TWO AREAS WILL BE
THE FOCUS FOR CONTINUED THUNDERSTORM DEVELOPMENT THROUGH THIS
EVENING.
POTENTIAL FOR STRONGEST THUNDERSTORMS WILL BE ACROSS THE
FAR SOUTHEAST PLAINS...NAMELY KIOWA...PROWERS AND BACA COUNTIES.
DEW POINTS EAST OF THE SFC TROF AXIS WILL REMAIN IN THE
50S...YIELDING 2500+ J/KG AND DEEP LAYER SHEARS OF 30-35 KTS. THIS
WILL BE SUFFICIENT FOR ONE OR TWO SEVERE THUNDERSTORMS THROUGH THE
LATE AFTERNOON AND EVENING HOURS. HRRR PUTS THE GREATEST THREAT
ACROSS EASTERN KIOWA...PROWERS AND BACA COUNTIES. ACTIVITY SHOULD
SHIFT EASTWARD INTO KS BY 00Z. FOR THE SOUTHWEST MTS...MAIN THREAT
WILL BE LOCALLY HEAVY RAINFALL...THOUGH STORM MOTIONS TO THE EAST AT
15-20 KTS SHOULD HELP MITIGATE THE THREAT FOR FLASH FLOODING ON THE
WEST FORK BURN SCAR SOME. THIS AREA WILL STILL NEED TO BE MONITORED
CLOSELY THOUGH.
LOW TEMPERATURES TONIGHT SHOULD STAY ON THE MILD SIDE...PARTICULARLY
FOR THE SE PLAINS WHERE DOWNSLOPE WESTERLY WINDS INTO THE SFC TROF
WILL CONTINUE. MOISTURE LEVELS INCREASE OUT WEST A TAD WHICH SHOULD
KEEP MINS UP A COUPLE DEGREES OVER LAST NIGHTS VALUES AS WELL.
UPPER TROF WILL DROP OUT OF CANADA AND ACROSS THE NRN U.S. ROCKIES
ON SATURDAY. THIS WILL EVENTUALLY SEND A COLD FRONT THROUGH THE
SOUTHEAST PLAINS LATE SAT AFTN/EVENING. AHEAD OF THE FRONT ON
SATURDAY...EXPECT TEMPERATURES TO WARM QUICKLY. DEW POINTS WILL BE
THE LIMITING FACTOR...THOUGH THEY DO START TO REBOUND FROM THE 30S
INTO THE 40S ACROSS NORTHERN PORTIONS OF THE SE PLAINS LATE SAT AS
THE FRONT DROPS IN. CAPE VALUES WILL BE CONSIDERABLY
LOWER...PERHAPS UP TO 1000 J/KG BUT MOST LIKELY BELOW THIS VALUE.
SO NOT EXPECTING ANY SEVERE THUNDERSTORMS. BUT COULD SEE SOME
ISOLATED STRONGER CELLS CAPABLE OF PRODUCING LOCALLY HEAVY
RAINFALL...WHICH WOULD BE MORE OF A CONCERN FOR BURN SCARS IN EL
PASO COUNTY. FOR NOW...THREAT DOESN`T LOOK ALL THAT HIGH.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 300 PM MDT FRI AUG 21 2015
...COOLER SUNDAY WITH A SLOW RETURN OF THE MONSOON INTO MIDDLE OF
NEXT WEEK...
SATURDAY NIGHT-SUNDAY NIGHT...MODERATE TO STRONG WEST TO NORTHWEST
LOW ALOFT ACROSS THE REGION SATURDAY NIGHT MODERATES THROUGH THE DAY
ON SUNDAY...AS A PASSING NORTHERN TIER UPPER TROUGH CONTINUES TO
TRANSLATE SOUTH AND EAST ACROSS THE NORTHERN ROCKIES AND NORTHERN
HIGH PLAINS AND UPPER LEVEL RIDGING REBUILDS WEST ACROSS THE
SOUTHERN ROCKIES AND INTO THE DESERT SOUTHWEST. MODELS REMAIN
SIMILAR WITH BEST FORCING NORTH OF THE AREA...ALTHOUGH COULD SEE
SOME CONVECTION ALONG AN ASSOCIATED COLD FRONT MOVING ACROSS EASTERN
COLORADO LATE SATURDAY AFTERNOON THROUGH SATURDAY NIGHT. COLD FRONT
WILL ALSO BE MARKED WITH GUSTY NORTH TO NORTHEAST WINDS OF 20-30 MPH
IN ITS WAKE. OVERNIGHT LOWS TO BE TRICKY SATURDAY NIGHT...ESPECIALLY
ACROSS EASTERN COLORADO WITH WINDS SLOWLY DECOUPLING BEHIND SAID
FRONT. MODELS INDICATING A SLIGHT INCREASE IN AVAILABLE MOISTURE ON
SUNDAY...SUPPORTING ISOLATED TO SCATTERED STORMS OVER AND NEAR THE
HIGHER TERRAIN. THE BEST COVERAGE OF STORMS LOOK TO BE ACROSS THE
SOUTHERN MTS WITH THE EASTERN PLAINS EXPECTED TO BE CAPPED. HIGHS ON
SUNDAY TO BE 5-15F COOLER THAN SATURDAY...MOST NOTABLE OVER THE
EASTERN PLAINS WITH BREEZY SOUTH TO SOUTHEAST UPSLOPE FLOW
DEVELOPING IN THE AFTERNOON. WARMING ALOFT NOTED ACROSS THE AREA
SUNDAY NIGHT...THOUGH COULD SEE SOME COOLER OVERNIGHT LOWS SUNDAY
NIGHT WITH GOOD RADIATIONAL COOLING ACROSS THE LOWER ELEVATIONS.
MONDAY-FRIDAY...A RETURN TO A MORE MONSOONAL PATTERN LOOKS TO BE IN
THE OFFING AS THE UPPER RIDGE ACROSS THE DESERT SOUTHWEST AND INTO
THE GREAT BASIN SLOWLY BUILDS EAST ACROSS THE CENTRAL AND NORTHERN
ROCKIES. SOME DIFFERENCES NOTED IN LONGER RANGE MODELS WITH THE
LATEST GFS BRINGING A DISTURBANCE ACROSS THE STATE ON WEDNESDAY
SUPPORTING MORE WIDESPREAD CONVECTION ACROSS THE AREA...WHERE AS THE
ECMWF IS SLOWER AND FURTHER NORTH WITH THE DISTURBANCE. AT ANY
RATE...SHOULD SEE A SLOW INCREASE IN SUBTROPICAL MOISTURE THROUGH
THE PERIOD...WITH DAILY CHANCES OF SHOWERS AND THUNDERSTORMS OVER
AND NEAR THE HIGHER TERRAIN SLOWLY INCREASING AND SPREADING EAST
THROUGH THE PERIOD. AT OR ABOVE SEASONAL TEMPERATURES EXPECTED TO
RETURN TO THE AREA THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 300 PM MDT FRI AUG 21 2015
CONDITIONS SHOULD REMAIN VFR AT THE TERMINALS...WITH SMOKE
REDUCING THE VISIBILITIES AT TIMES. FOR NOW...DO NOT THINK SMOKE
WILL BECOME THICK ENOUGH TO REDUCE VISIBILITIES TO UNDER 6 MILES.
ISOLATED THUNDERSTORMS THIS EVENING ARE EXPECTED TO BYPASS THE
TERMINALS...THOUGH KALS COULD SEE A WINDOW OF GUSTY WEST WINDS IF
THUNDERSTORM OUTFLOWS HOLD TOGETHER AS THEY PUSH EASTWARD OFF THE
SOUTHWEST MTS. THUNDERSTORMS WILL DIMINISH THIS EVENING. A FRONT
WILL DROP SOUTH OF THE PALMER DIVIDE SAT AFTERNOON...AND WILL
BRING A SLIGHTLY BETTER CHANCE FOR THUNDERSTORMS AT THE KCOS TAF
SITE DURING THE AFTERNOON. LIGHTNING...BRIEF RAINFALL AND GUSTY
OUTFLOW WINDS WILL BE THE PRIMARY STORM THREATS. THIS FRONT WILL
SHIFT SOUTHWARD INTO THE KPUB AREA AROUND 00Z SUN. NORTHERLY WIND
GUSTS BEHIND THE FRONT COULD GUST UP TO 30-35 KTS AT BOTH KCOS AND
KPUB. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KT
LONG TERM...MW
AVIATION...KT
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
303 PM EDT FRI AUG 21 2015
.DISCUSSION...
TONIGHT AND SATURDAY...EAST AND WEST COAST BREEZE BOUNDARIES
COMING TOGETHER OVER THE CENTER OF THE STATE WILL BRING THE BEST
CHANCE FOR STORM DEVELOPMENT LATE THIS AFTERNOON AND INTO THE
EARLY EVENING. LTST HRRR GUID SHOWS A BREEZE COLLISION WEST OF
METRO ORLANDO AFTER 5 PM. A FEW STRONG STORMS WILL BE POSSIBLE
WITH WIND GUSTS OF 40 TO 50 MPH AND FREQUENT LIGHTNING...ESP FROM
THE THEME PARKS TO LAKE COUNTY AND LAKE GEORGE. PCPN TIED TO SFC
HEATING AND BOUNDARY COLLISIONS SHOULD COME TO AN END OVER LAND
AREAS BY 1030 PM.
SAT...STACKED HIGH OVER THE STATE WL MAINTAIN CONTROL WITH MORE
STABLE CONDS OVERALL. NE WINDS WL WOKR SWD FROM THE MID ATLC
SEABOARD...PROVIDING ADTL LWR LEVEL STABILITY IN THE FORM OF A
MARINE INFLUENCE TO THE COAST AND ESP NORTHERN AREAS. PRECIP CHCS
HAVE BEEN TAPERED BACK TO ISOLD ALONG THE CST AND 30 TO 40
PERCENT INLAND. CONVERGENCE IN THE AFTN BEST SUITABLE FOR PCPN
DEVELOPMENT SHOULD LARGELY OCCUR OVER THE WESTERN SIDE OF THE
PENINSULA.
SUN...(MODIFIED PREV DISC)...MID-LEVEL HIGH PRESSURE OVER THE
GOMEX GRADUALLY WEAKENS AS SHORTWAVE IMPULSES TRAVERSE THE N/NE
PERIPHERY OF THIS ANTI-CYCLONE. THIS WILL ALLOW NORTHERLY WINDS
TO BACK TO NORTHWESTERLY. 500 MB TEMPERATURES WILL REMAIN FAIRLY
WARM AT -5C/- 6C. AT THE SURFACE HIGH PRESSURE ACROSS THE EASTERN
CONUS WILL WEAKEN AND DRIFT TOWARD THE EASTERN SEABOARD/WESTERN
ATLC WITH THE APPROACH OF A COLD FRONT. THE SURFACE PRESSURE
GRADIENT WILL REMAIN WEAK THROUGH THIS PERIOD WITH LIGHT
NORTHEASTERLY FLOW. THE EAST COAST SEA BREEZE WILL DEVELOP EACH
DAY AND PUSH INLAND. GREATEST STORM CHANCES WILL FAVOR THE
INTERIOR EACH AFTERNOON WITH STEERING FLOW FROM THE N/NNE.
MON-THU...TROUGHING IN THE MID-LEVELS WILL GRADUALLY DEVELOP ACROSS
THE EASTERN CONUS THROUGH THIS TIME AS NWRLY FLOW ALOFT BECOMES
SWRLY ACROSS THE AREA. DEEP LAYER MOISTURE WILL BE LOWER THAN
PREVIOUS DAYS. A WEAK SURFACE BOUNDARY WILL BECOME NEAR STATIONARY
ACROSS THE DEEP SOUTH WITH WEAK HIGH PRESSURE CONTINUING OVER ECFL.
OUR LIGHT ONSHORE FLOW WILL BECOME LIGHT S/SWRLY WED-THU THOUGH THE
EAST COAST SEA BREEZE WILL STILL DEVELOP EACH AFTERNOON AND PUSH
INLAND. NORTHERLY STORM STEERING FLOW WILL CONTINUE MON-TUE WITH
LOWER CONFIDENCE WED-THU IN STORM MOTION...THOUGH IT APPEARS TO BE
LIGHT/ERRATIC FOR NOW. LOWER THAN NORMAL PRECIPITATION CHANCES LIKELY
MON-TUE WITH AN UPTICK AGAIN MOVING INTO/PAST MID-WEEK TOWARDS CLIMO
NUMBERS.
&&
.AVIATION...VFR CONDS ALL COASTAL SITES WITH BRIEF MVFR CONDS
PSBL INTERIOR SITES THIS AFTN THROUGH 22/02Z IN ISOLD RELATIVELY
BRIEF TSRA/SHRA...OTHERWISE VFR CONDS INTERIOR AS WELL THROUGH
22/16Z.
&&
.MARINE...
TONIGHT AND SATURDAY...LIGHT WINDS WITH THE DIURNAL ONSHORE
BREEZE IN THE AFTERNOON WL MAINTAIN SIG WVS 2 FT OR LESS DURING
THE PERIOD. ONSHORE WINDS WILL INCREASE FROM N TO S ON SAT AS A
NE PRIMARY WIND ENTERS THE NE AND CENTRAL FL WATERS BY LATE
SATURDAY AFTN.
NEXT WEEK...WEAK PRESSURE GRADIENT OVER THE AREA WITH A LIGHT
N/NE WIND FLOW BELOW 10 KTS. GRADIENT IS SO WEAK THAT WINDS MAY BE
MORE VARIABLE IN DIRECTION AT TIMES. THE ECSB WILL DEVELOP EACH
AFTERNOON PUSHING INLAND WITH A SLIGHT BUMP UP IN SPEEDS NEAR THE
IMMEDIATE COAST. ONLY AN ISOLD THREAT FOR SHRA/TSRA. SEA HEIGHTS
AOB 3 FT.
MON-TUE...THE WEAK PRESSURE GRADIENT AND LIGHT WIND FIELDS CONTINUE
INTO EARLY WEEK AS A WEAK FRONTAL BOUNDARY SETTLES ACROSS THE DEEP
SOUTH/SOUTHEAST U.S. DAILY SEA BREEZE FORMATION AND PUSH INLAND
DURING THE AFTERNOON WILL ALSO REMAIN COMMON. SHOWER/STORM CHANCES
REMAIN ISOLD. SEAS AOB 3 FT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 76 93 76 90 / 20 20 20 20
MCO 76 94 76 93 / 30 40 20 20
MLB 76 92 77 90 / 20 20 20 20
VRB 73 91 74 89 / 20 20 20 20
LEE 77 95 77 93 / 30 40 20 30
SFB 77 95 77 93 / 30 40 20 20
ORL 77 95 77 94 / 30 40 20 20
FPR 74 92 74 89 / 20 20 20 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
PUBLIC/MARINE...PENDERGRAST
IMPACT WEATHER/AVIATION...WIMMER
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
310 PM EDT FRI AUG 21 2015
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
FRONTAL BOUNDARY CONTINUES ACROSS CENTRAL GA THIS AFTERNOON. THE
BOUNDARY WILL CONTINUE TO OOZE SOUTHWARD THROUGH THE EVENING. IN THE
MID LEVELS...WV AND RAP ANALYSIS SHOWS A FAIRLY DECENT SHORTWAVE
HELPING TO ENHANCE SHOWERS AND THUNDERSTORM DEVELOPMENT IN
CENTRAL/EASTERN AL. THE SHORTWAVE WILL CONTINUE EASTWARD...SPREADING
CONVECTION INTO NORTH CENTRAL GA AND WILL ALSO HELP PUSH THE OLD
FRONT A LITTLE FURTHER SOUTH.
SURFACE INSTABILITY IS GREATEST ALONG AND SOUTH OF THE FRONT BUT MID
LEVEL LAPSE RATES REMAIN WEAK. WITH HIGH PWATS...MAIN HAZARDS FROM
STORMS WILL BE LOCALLY HEAVY RAINFALL PLUS FREQUENT LIGHTNING. A FEW
STRONG STORMS ARE POSSIBLE WITH GUSTY WINDS.
THE FRONT SHOULD MOVE TO OVER THE SOUTHERN PORTION OF THE CWFA
TONIGHT. WITH THE LOSS OF HEATING...CONVECTIVE COVERAGE SHOULD
MOSTLY DIMINISH.
MODELS ARE PROGGING ANOTHER GOOD SHORTWAVE TO MOVE EAST IN THE FLOW
TOMORROW. THE DISTURBANCE WILL INTERACT WITH THE OLD BOUNDARY AND
PRODUCE SCATTERED/ISOLD SHRA/TSRA AGAIN TOMORROW AFTERNOON.
NLISTEMAA
.LONG TERM /SUNDAY THROUGH FRIDAY/...
MAINLY ONLY TWEAKS TO THE LONG TERM BASED ON THE LASTEST GUIDANCE.
BDL
PREVIOUS DISCUSSION...
THE EXTENDED FORECAST START OFF WITH WEAKENING BOUNDARY ACROSS
CENTRAL GA SUNDAY MOVING SOUTH. THE NEXT FRONTAL SYSTEM BEGINS TO
MOVE INTO N GA MONDAY MORNING BUT THERE IS NOT MUCH MOISTURE ASSOCIATED
WITH IT. THIS BOUNDARY WILL ACT AS A CATALYST FOR STORMS TO
DEVELOP ACROSS THE AREA MONDAY AND TUESDAY BUT IT WILL ALSO USHER
IN A MUCH DRIER AIRMASS TUESDAY NIGHT. THIS DRIER AIR IS EXPECTED
TO STAY ACROSS THE REGION THROUGH THURSDAY WHICH WILL KEEP
SHRA/TSRA ACTIVITY TO A MINIMUM. ALL IN ALL IT LOOKS LIKE WE MAY
BE IN THE BEGINNING STAGES OF TRANSITIONING TO A MORE FALL LIKE
PATTERN...WITH FRONTS MOVING THROUGH THE STATE GIVING THE CWA
MOSTLY CLEAR SKIES FOR A FEW DAYS AND NOT STALLING ACROSS CENTRAL
OR SOUTH GA. TEMPS REMAIN IN THE MID 80S TO MID 90S THROUGH THE
EXTENDED.
01
&&
.AVIATION...
18Z UPDATE...
CONVECTION HAS BEGUN DEVELOPING ACROSS THE AREA WITH KMCN AND KCSG
ALONG MAIN LINE. SO FAR STORMS HAVE REMAINED SHOWERS BUT WE ARE
EXPECTING THUNDERSTORMS ACROSS THE TAF SITES MAINLY 19-24Z. WINDS
WILL BE NORTHWEST TO WEST AT 5-10KTS INITIALLY...DIMINISHING AFTER
00Z WITH THE LOOS OF HEATING. PATCHY FOG WILL DEVELOP IN THE USUAL
SUSPECTS AND RAIN SOAKED AREAS BY DAYBREAK WITH MVFR VISIBILITIES.
EXPECT CIGS IN MVFR/VFR RANGE THROUGH THE PERIOD.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM CONFIDENCE ON CIGS/TIMING OF TS
MEDIUM TO HIGH ON ALL OTHER ELEMENTS.
ATWELL
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 71 89 72 90 / 30 30 20 40
ATLANTA 73 89 73 89 / 20 30 20 40
BLAIRSVILLE 64 83 66 84 / 30 30 20 50
CARTERSVILLE 69 90 69 90 / 20 30 20 40
COLUMBUS 75 92 75 92 / 20 30 20 30
GAINESVILLE 71 86 71 87 / 30 30 20 50
MACON 73 93 74 92 / 30 30 20 40
ROME 69 89 70 90 / 20 20 20 30
PEACHTREE CITY 71 91 72 90 / 20 30 20 40
VIDALIA 75 93 74 92 / 30 30 20 50
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...NLISTEMAA
LONG TERM....BDL
AVIATION...NLISTEMAA
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
201 PM EDT FRI AUG 21 2015
.PREV DISCUSSION... /ISSUED 949 AM EDT FRI AUG 21 2015/
UPDATE...
OLD FRONTAL BOUNDARY CURRENTLY DRAPED ACROSS CENTRAL GA THIS
MORNING. IN THE MID LEVELS...A SHEAR AXIS IS SITUATED ALMOST
DIRECTED ON TOP OF THE BOUNDARY.
WV AND 500MB RAP ANALYSIS SHOWS A WEAK WAVE SHORTWAVE ASSOCIATED
WITH THE SHOWERS ACROSS EASTERN GA THIS MORNING. THERE ARE TWO MORE
SHORTWAVES ANALYZED IN THE FLOW...ONE ACROSS CENTRAL AL AND ANOTHER
ACROSS THE ARKLAMISS. THE WAVE ACROSS CENTRAL AL SHOULD HELP SCT
CONVECTION DEVELOP THIS AFTERNOON DURING PEAK HEATING ACROSS MUCH OF
THE CWFA.
HAVE UPDATED THE POPS ACCORDING TO THE LATEST RADAR TRENDS. HAVE
ALSO TWEAKED THE AFTERNOON POPS A BIT TO COME A LITTLE MORE INTO
LINE WITH THE HRRR...WHICH HAS A PRETTY GOOD HANDLE ON THE SHRA THAT
ARE ONGOING.
LOCALLY HEAVY RAINFALL AND FREQUENT LIGHTNING STRIKES ARE THE MAIN
HAZARDS ASSOCIATED WITH ANY THUNDERSTORMS THIS AFTERNOON.
PREV DISCUSSION... /ISSUED 414 AM EDT FRI AUG 21 2015/
SHORT TERM /TODAY THROUGH SATURDAY/...
NAM/GFS/ECMWF IN VERY GOOD AGREEMENT THROUGH THE SHORT TERM. SURFACE
TROUGH HAS STALLED ACROSS NORTH GEORGIA KEEPING MOST OF THE CWA IN
THE WARM AND MOIST SECTOR. THIS TROUGH WILL NOT MOVE MUCH BUT SHOULD
BE A FOCUS FOR CONVECTION THIS AFTERNOON AS A WEAK WAVE MOVES ALONG
THE BOUNDARY. AFTER THIS WAVE MOVES TO OUR EAST...THE SURFACE TROUGH
WILL SHIFT SOUTH. CAPES REMAIN IN THE 1500-2000 RANGE ALONG WITH
PWATS RANGING FROM 1.8 TO 2.1 INCHES. WILL KEEP HIGH CHANCE POPS
ACROSS NORTH AND PARTS OF CENTRAL GA WHERE THE DEEPEST MOISTURE WILL
BE WITH CHANCE POPS ELSEWHERE. CONVECTION WILL DIMINISH QUICKLY THIS
EVENING. ON SATURDAY EXPECT CONVECTION AGAIN ALTHOUGH WITH SLIGHTLY
DRIER AIR OVER THE REGION WILL LIMIT POPS TO SLIGHT CHANCE TO CHANCE
AND MAINLY DURING THE AFTERNOON. GUIDANCE TEMPS HAVE BEEN RUNNING 1
TO 2 DEGREES TOO LOW OVER THE PAST 10 DAYS AND HAVE THEREFORE RAISED
MAX TEMPS BOTH DAYS BY A DEGREE OR TWO.
17
LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
THE EXTENDED FORECAST START OFF WITH WEAKENING BOUNDARY ACROSS
CENTRAL GA SUNDAY MOVING SOUTH. THE NEXT FRONTAL SYSTEM BEGINS TO
MOVE INTO N GA MONDAY MORNING BUT THERE IS NOT MUCH MOISTURE ASSOCIATED
WITH IT. THIS BOUNDARY WILL ACT AS A CATALYST FOR STORMS TO
DEVELOP ACROSS THE AREA MONDAY AND TUESDAY BUT IT WILL ALSO USHER
IN A MUCH DRIER AIRMASS TUESDAY NIGHT. THIS DRIER AIR IS EXPECTED
TO STAY ACROSS THE REGION THROUGH THURSDAY WHICH WILL KEEP
SHRA/TSRA ACTIVITY TO A MINIMUM. ALL IN ALL IT LOOKS LIKE WE MAY
BE IN THE BEGINNING STAGES OF TRANSITIONING TO A MORE FALL LIKE
PATTERN...WITH FRONTS MOVING THROUGH THE STATE GIVING THE CWA
MOSTLY CLEAR SKIES FOR A FEW DAYS AND NOT STALLING ACROSS CENTRAL
OR SOUTH GA. TEMPS REMAIN IN THE MID 80S TO MID 90S THROUGH THE
EXTENDED.
01
&&
.AVIATION...
18Z UPDATE...
CONVECTION HAS BEGUN DEVELOPING ACROSS THE AREA WITH KMCN AND KCSG
ALONG MAIN LINE. SO FAR STORMS HAVE REMAINED SHOWERS BUT WE ARE
EXPECTING THUNDERSTORMS ACROSS THE TAF SITES MAINLY 19-24Z. WINDS
WILL BE NORTHWEST TO WEST AT 5-10KTS INITIALLY...DIMINISHING AFTER
00Z WITH THE LOOS OF HEATING. PATCHY FOG WILL DEVELOP IN THE USUAL
SUSPECTS AND RAIN SOAKED AREAS BY DAYBREAK WITH MVFR VISIBILITIES.
EXPECT CIGS IN MVFR/VFR RANGE THROUGH THE PERIOD.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM CONFIDENCE ON CIGS/TIMING OF TS
MEDIUM TO HIGH ON ALL OTHER ELEMENTS.
ATWELL
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 90 71 89 71 / 50 50 30 20
ATLANTA 89 71 90 73 / 50 50 30 20
BLAIRSVILLE 82 65 84 63 / 40 40 30 20
CARTERSVILLE 89 69 91 69 / 40 50 30 10
COLUMBUS 91 74 93 75 / 40 40 20 20
GAINESVILLE 86 71 87 71 / 50 50 30 20
MACON 92 73 93 73 / 40 40 20 20
ROME 87 68 90 69 / 40 50 30 10
PEACHTREE CITY 89 70 91 71 / 50 50 30 20
VIDALIA 93 76 94 74 / 40 40 20 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...NLISTEMAA
LONG TERM....BDL
AVIATION...ATWELL
AREA FORECAST DISCUSSION
NWS DES MOINES IA
121 PM CDT FRI AUG 21 2015
.SHORT TERM /TODAY/...
ISSUED AT 346 AM CDT FRI AUG 21 2015
MAIN FORECAST CONCERN WAS FOCUSED ON TEMPERATURES AND WINDS FOR
THIS AFTERNOON...AND WITH WEAK SHORTWAVE PROVIDING SOME ISOLATED
SHOWERS/STORMS THROUGH THE MID-MORNING. A FEW ELEVATED
SHOWERS/STORMS HAVE DEVELOPED OVER WEST-CENTRAL TO NORTHWEST IOWA
AND LOOK TO MEANDER INTO NORTH-CENTRAL IOWA THROUGH 15Z THIS
MORNING. THERE IS ENOUGH FORCING AND ELEVATED INSTABILITY...ALBEIT
VERY WEAK...BUT ENOUGH TO WARRANT SLIGHT/LOW CHANCE POPS OVER THE
NORTH. HOWEVER WITH A A STRONG CAP IN PLACE TODAY...IT WILL LIMIT
ANYTHING PAST 15Z. THE LATEST 21.07Z HRRR HAS A DECENT HANDLE ON
THE CONVECTIVE TRENDS AND LEANED TOWARD ITS SOLUTION FOR POPS/WX.
STRONG MIXING AND WAA DEVELOP TODAY AS PRESSURE GRADIENT TIGHTENS
THIS AFTERNOON. MIXING TO AROUND 850MB PUTS HIGHS IN THE LOWER 80S
AND TWEAKED MAX TEMPS UP SLIGHTLY. THE MAV/ECS HAD A GREAT HANDLE
ON TEMPS TODAY AS THE MET WAS TOO COLD THROUGHOUT THE FORECAST
AREA. ALSO TWEAKED UP WINDS SLIGHTLY AS WINDS ATOP THE MIXED LAYER
IN THE 25-30 KNOT RANGE.
.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 346 AM CDT FRI AUG 21 2015
THE LONG TERM FORECAST IS CHARACTERIZED BY VARYING TEMPERATURES
AND MOSTLY DRY CONDITIONS BUT PUNCTUATED AND HEADLINED BY THE
STORM SYSTEM MOVING ACROSS THE REGION ON SATURDAY AND SATURDAY
NIGHT. THE DRIVER FOR THIS SYSTEM WILL COME IN THE FORM OF A
MID/UPPER LEVEL TROUGH...STRONG FOR THIS SEASON...MOVING ACROSS
THE NORTHERN ROCKIES ON FRIDAY NIGHT AND OVER THE DAKOTAS AND
MINNESOTA ON SATURDAY AND SATURDAY NIGHT. THIS WILL BE REFLECTED
AT THE SURFACE BY A STEADILY STRENGTHENING
TROUGH/FRONT...INITIALLY STRETCHING DOWN THE HIGH PLAINS AND THEN
SWEEPING EAST/SOUTHEAST IN RESPONSE TO THE PROGRESSION OF THE
MID/UPPER TROUGH ON SATURDAY/SATURDAY NIGHT. AHEAD OF THIS SYSTEM
MOST OF SATURDAY WILL BE WARM AND INCREASINGLY BREEZY ACROSS OUR
FORECAST AREA AS THE SURFACE PRESSURE GRADIENT TIGHTENS UP
BETWEEN THE HIGH PLAINS TROUGH AND A LARGE HIGH PRESSURE AREA
DEPARTING TO THE EAST. FOR MUCH OF THE DAY THINGS WILL REMAIN
QUIET...BUT BY PEAK HEATING IN THE LATE AFTERNOON/EVENING
INSTABILITY WILL BE MAXIMIZED AND THE SURFACE FRONT WILL SERVE AS
A MECHANISM FOR THUNDERSTORM DEVELOPMENT COINCIDENT WITH THE
ARRIVAL OF STRONGER FORCING AND WIND FIELDS ALOFT GIVEN THE
APPROACH OF THE MID/UPPER TROUGH. INITIAL STORMS WILL LIKELY BE
ORGANIZED WITHIN THIS ENVIRONMENT PROVIDING A FAIRLY SUBSTANTIAL
SEVERE WEATHER THREAT...THEN AS THE SYSTEM MOVES EAST/SOUTHEAST
WITH SUNSET THE STORMS SHOULD BECOME MORE LINEAR AND GRADUALLY
DIMINISH IN INTENSITY BY THE TIME THEY REACH EASTERN IOWA. FOR NOW
THE PRIMARY QUESTIONS ARE WHERE THE STORMS WILL INITIALLY
DEVELOP...OVER SOUTH DAKOTA/MINNESOTA/NEBRASKA OR OVER
WESTERN/NORTHWESTERN IOWA...AND HOW FAR EAST/SOUTHEAST THEY WILL
REMAIN SEVERE AS THEY MOVE QUICKLY ACROSS THE STATE. SPC PRODUCTS
HANDLE THE THREAT WELL AND WILL BE CLOSELY MONITORED TODAY AND
TOMORROW.
AFTER THE FRONT AND ASSOCIATED STORMS BLOW THROUGH ON SATURDAY
NIGHT WE WILL ONCE AGAIN SEE MOSTLY CLEAR...COOL...AND BREEZY
WEATHER FROM SUNDAY INTO EARLY NEXT WEEK. BY MONDAY THE 500 MB
PATTERN WILL FEATURE A DEEPENING GYRE OVER THE GREAT LAKES
REGION...THAT BEING THE SYSTEM THAT AFFECTED US ON
SATURDAY/SATURDAY NIGHT...WITH A DEVELOPING RIDGE OVER THE FOUR
CORNERS REGION. INITIALLY THIS WILL PLACE IOWA BENEATH PERSISTENT
NORTHWEST FLOW RESULTING IN A VERY SLOW WARMING TREND. BY MIDWEEK
AS THE EASTERN GYRE DEPARTS THE WESTERN RIDGE WILL BUILD FURTHER
AND APPROACH OUR AREA...BUT MOST OF THE HEAT BUBBLE SHOULD REMAIN
WEST/SOUTHWEST OF IOWA THROUGH AT LEAST WEDNESDAY. THERE ARE
CONSISTENT INDICATIONS THAT A SHORTWAVE WILL OVERTOP THE 500 MB
RIDGE SOMETIME AROUND THURSDAY...POSSIBLY PROVIDING US WITH
ANOTHER CHANCE FOR RAIN BUT MORE IMPORTANTLY SHUNTING THE RIDGE
SOUTHWARD FOR A DAY OR TWO. BEYOND THIS...LOOKING TOWARD THE NEXT
WEEKEND OR SO...IT REMAINS UNCERTAIN WHETHER THE LARGE RIDGE WILL
BE ABLE TO BUILD UP OVER THE MIDWEST OR WILL REMAIN JUST TO OUR
SOUTHWEST. THIS WILL DETERMINE WHETHER WE GET ONE LAST BLAST OF
SUMMER HEAT OR NOT.
&&
.AVIATION...21/18Z
ISSUED AT 119 PM CDT FRI AUG 21 2015
GENERALLY VFR CONDITIONS THROUGH THE PERIOD. LOW POTENTIAL FOR
STRATUS DEVELOPING OVERNIGHT HOWEVER WINDS SHOULD REMAIN STRONG
ENOUGH TO KEEP THIS POTENTIAL AT A MINIMUM. OTHERWISE BREEZY
SOUTHERLY WINDS TODAY DIMINISHING OVERNIGHT THEN INCREASING AGAIN
SATURDAY MORNING.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...LEE
AVIATION...DONAVON
AREA FORECAST DISCUSSION
NWS GOODLAND KS
241 PM MDT FRI AUG 21 2015
.UPDATE...
ISSUED AT 1003 AM MDT FRI AUG 21 2015
CURRENT FORECAST FOR THE AFTERNOON AND EVENING LOOKS ON TRACK
WITH THE LATEST OBSERVATIONS AND MODEL DATA. DID ADJUST THE
COVERAGE AND VALUE OF THE RAINFALL CHANCES A BIT GIVEN THE GOOD
AGREEMENT AMONG THE MODELS FOR THE STORM ACTIVITY THIS AFTERNOON.
EXPECT STORMS TO DEVELOP ALONG A SURFACE TROUGH/DRY LINE OVER THE
WESTERN PART OF THE AREA. THE STRONGEST LIFT WILL REMAIN TIED
TO THE NEARLY STATIONARY TROUGH THROUGH THE AFTERNOON...SO EXPECT
STORMS TO DEVELOP ALONG IT AND MOVE SLOWLY EAST. THE MAIN QUESTION
WILL BE HOW FAR EAST WILL THE STORMS GO BEFORE DISSIPATING SINCE
THE MAJORITY OF THE LIFT WILL REMAIN WITH THE SURFACE TROUGH.
CURRENTLY LOOKS LIKE THE MAJORITY OF THE STORMS WILL WEAKEN BY THE
TIME THEY REACH THE HIGHWAY 83 CORRIDOR...ALTHOUGH STORMS WHICH
MOVE OVER SOUTHWEST NEBRASKA MAY MAKE IT ALL THE WAY THROUGH RED
WILLOW COUNTY BEFORE DISSIPATING.
FOR THE EVENING AM NOT TOO CONFIDENT REGARDING STORMS EAST OF
HIGHWAY 25. AM THINKING ONCE THE SURFACE HEATING ENDS THE NOSE OF
THE LOW LEVEL JET WILL SERVE AS THE PRIMARY TRIGGER FOR
STORMS...WHICH WILL BE PRIMARILY WEST OF HIGHWAY 27. HOWEVER
SOUNDINGS INDICATE A FAIRLY DRY ENVIRONMENT DURING THE
EVENING WEST OF HIGHWAY 27...WHICH MAY HINDER STORM DEVELOPMENT
DESPITE THE INFLUENCE OF THE NOSE OF THE LOW LEVEL JET.
ASIDE FROM THE STORMS DID INCREASE THE WINDS DUE TO THE
STRENGTHENING LOW LEVEL JET IN THE AFTERNOON MIXING TO THE GROUND.
WEST OF THE SURFACE TROUGH THE WINDS WILL BE LIGHT DUE TO THE LOW.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 330 AM MDT FRI AUG 21 2015
FORECAST CONCERNS WILL BE THUNDERSTORM CHANCES INTO THE BEGINNING OF
THE WEEKEND AND HOW COOL TO MAKE IT SATURDAY NIGHT INTO SUNDAY
NIGHT. SATELLITE SHOWING AN AMPLIFIED/BLOCKY OVER THE PACIFIC. THIS
TRANSITIONS TO A BROAD TROUGH/WESTERLY ALOFT OVER MOST OF THE
COUNTRY. STRONG SYSTEM DIGGING INTO SOUTHWEST CANADA WITH SEVERAL
SHORTWAVE TROUGHS EMBEDDED IN THE WESTERLY FLOW.
AT JET LEVEL...MODELS DID WELL. AT MID LEVELS...THE GFS/CANADIAN AND
THE UKMET WERE DOING A LITTLE BETTER THAN THE ECMWF. THE SREF AND
ESPECIALLY THE NAM WERE NOT DOING WELL. THE GFS WAS DOING A LITTLE
BETTER THAN THE ECMWF WITH THE LOW LEVEL WIND FIELD. ALL MODELS
INITIALIZED WELL ON THE LOW LEVEL THERMAL FIELD
DIFFICULT AND UNCERTAIN PRECIPITATION FORECAST...ESPECIALLY
THROUGH THIS EVENING. CONFIDENCE IS BELOW AVERAGE FOR THE
PRECIPITATION FORECAST.
TODAY/TONIGHT...WILL HAVE TO KEEP AN EYE ON ANY LATE NIGHT/EARLY
MORNING DEVELOPMENT NEAR THE BOUNDARY JUST TO THE NORTH OF OUR
AREA. MODELS HAVE BEEN HINTING AT IT AND WILL CONTINUE TO MONITOR.
FOR YESTERDAYS THUNDERSTORMS...JUST ENOUGH MOISTURE ALONG A
BOUNDARY WITH A WEAK SHORTWAVE TROUGH WAS ABLE TO SPARK ISOLATED
THUNDERSTORMS OVER AND NEAR THE NORTHEAST PORTION OF THE AREA. NOT
TOO DIFFERENT A SETUP FOR TODAY FROM YESTERDAY. AGAIN WHAT MAKES
FORECAST UNCERTAIN IS THE MOISTURE AVAILABILITY...ESPECIALLY
ABOVE THE LOW LEVELS...WHERE DOES THE SURFACE TROUGH SETUP AND THE
WEAK/COMPLICATED MID LEVEL FORCING INVOLVED.
MODELS HAVE THE BOUNDARY PRETTY CLOSE BUT A LITTLE FURTHER WEST THAN
WHAT WAS SHOWN YESTERDAY. 700 MB SHORTWAVE EJECTS INTO THE PLAINS THIS
AFTERNOON AND IT LOOKS TO BE IN TWO PIECES. ONE PORTION GOES
ACROSS THE NORTH AND IS THE SLOWER OF THE TWO SHORTWAVE TROUGHS.
THE SECOND ONE GOES ACROSS TO OUR SOUTH AND BRUSHES THE SOUTHERN
PORTION OF THE AREA. THERE IS WEAK FORCING IN BETWEEN. ALSO THE
MODELS DIFFER ON HOW FAR EAST DURING THE DAY THEY MOVE THESE
SHORTWAVE TROUGHS.
CONVECTIVE ALLOWING MODELS ARE HAVING A DIFFICULT WITH ALL THIS. THE
ARW HAS LITTLE TO NOTHING. THE HRRR AND ESPECIALLY THE NMM DEVELOP
ROBUST CONVECTION OVER THE WESTERN PORTION OF THE AREA THIS
AFTERNOON CLOSE TO THE SURFACE TROUGH. THE 00Z NAM DID NOT INDICATE
ANYTHING BUT NOW THE 06Z NAM IS MATCHING UP WITH THE ABOVE TWO
MODELS. THE 00Z ECMWF EXPLODES CONVECTION OVER THE NORTHERN PORTION
OF THE AREA. ALL THIS TIME A RATHER STOUT EML LIES OVER THE AREA.
AFTER LOOKING AT THIS AND COLLABORATION...PULLED THE INITIATION A
LITTLE FURTHER WEST THAN BEFORE. THE PROBLEM THEN BECOMES HOW FAR
EAST TO TAKE THIS ACTIVITY. THE HRRR TAKES IT FURTHER EAST WHILE THE
REST OF THE OUTPUT THAT DID DEVELOP SOMETHING JUST KEEPS IT OVER
THE WEST AS IT EITHER DISSIPATES THE THUNDERSTORMS OR MOVES THEM
OF THE AREA TO THE NORTH OR SOUTH. SO DID LOWER POPS A LITTLE DUE
TO THIS.
IT DOES LOOK LIKE THE THUNDERSTORMS END BY 06Z. HOWEVER ELEVATED
STORMS/REDEVELOPMENT WILL NEED TO BE LOOKED AT AGAIN TO A LOW LEVEL
JET AND DECENT WARM AIR ADVECTION PATTERN ALOFT AHEAD OF ANOTHER
SHORTWAVE TROUGH. FOR THIS AFTERNOON AND EVENINGS CONVECTION...IF
STORMS DEVELOP...IT WILL BE POSSIBLE THAT THESE WILL BECOME SEVERE
DUE TO THE INSTABILITY AND LAPSE RATES INVOLVED. NO MATTER IF
STORMS DEVELOP OR NOT...BOUNDARY LAYER MOISTURE INCREASES AND AT
THE VERY LEAST A LOT OF STRATUS WILL DEVELOP WITH SOME PATCHY FOG
INVOLVED.
PRESSURE FALLS AND GRADIENT SUPPORT NEAR BREEZY OR BREEZY CONDITIONS.
GUIDANCE HAS BEEN RUNNING COOL ON MAXES HERE THE LAST FEW DAYS.
THE GFS/MAV HAS BEEN DOING THE BEST AND HAVE RAISED THE MAXES SOME.
SATURDAY/SATURDAY NIGHT...PATCHY FOG ENDS BY MID MORNING WITH THE
STRATUS LASTING A LITTLE LONGER. THERE ARE STILL DIFFERENCES IN
HOW FAST THE MODELS BRING IN THE COLD FRONT. THE NAM IS THE
SLOWEST FOLLOWED BY SREF. THE GFS/ECMWF/CANADIAN ARE THE FASTEST.
ROUGHLY IT LOOKS LIKE THE FRONT IS THROUGH THE NORTHWEST HALF OF
THE AREA BY LATE MORNING. THE FRONT THEN LOOKS TO MOVE ACROSS THE
REST OF THE AREA BY LATE AFTERNOON OR EARLY EVENING.
THE CHANCE OF THUNDERSTORMS WILL BE OVER THE SOUTHEAST PORTION OF
THE AREA IN ADVANCE OF THIS FRONT. CONTINUED THE LOW CHANCE POPS IN
THIS AREA. FRONT AND ASSOCIATED FORCING EXIT THE AREA EARLY IN
THE EVENING AND SO PRECIPITATION CUTS OFF RATHER FAST.
WINDS BEHIND THE FRONT COULD GET WINDY AND THE DAY SHIFT WILL NEED
TO LOOK AT RAISING THE WINDS EVEN MORE. DESPITE SIMILAR TIMING TO
YESTERDAYS OUTPUT...MODELS HAVE RAISED HIGH TEMPERATURES FOR THE
DAY. THE GFS...CANADIAN AND THE NAM ARE IN DECENT AGREEMENT ON
THIS. IT SEEMS THAT THE COLDER AIR DOES LAG SLIGHTLY BEHIND THE
FRONT. DID RAISE MAXES A LITTLE BUT THEY MAY NEED TO BE RAISED
EVEN MORE IN SOUTHERN LOCATIONS.
WINDS STAY UP ENOUGH TONIGHT THAT TEMPERATURES SHOULD NOT DROP
LIKE A ROCK. IF THE WINDS LET UP QUICKER...GOOD RADIATIONAL
CONDITIONS WOULD BE IN PLACE AND A LOWERING OF THE MINS WOULD BE
NEEDED.
SUNDAY/SUNDAY NIGHT...DRY PERIOD WITH POST FRONTAL COOL AIR MASS IN
PLACE. NEW GUIDANCE FOR TEMPERATURES VERY SIMILAR TO WHAT WAS IN
THERE FOR MAXES AND MADE ONLY SLIGHT ADJUSTMENTS. ONCE AGAIN FOR THE
MINS...IF WINDS END UP BEING LESS THAN CURRENTLY PREDICTED ADDITIONAL
COOLING WILL BE NEEDED.
.LONG TERM...(SATURDAY THROUGH FRIDAY)
ISSUED AT 241 PM MDT FRI AUG 21 2015
FOR THIS RUN OF THE EXTENDED FORECAST...THE PRIMARY SENSIBLE WEATHER
TO FOCUS ON WILL BE SATURDAY INTO SATURDAY NIGHT AS A COLD FRONT
PASSES AND THUNDERSTORM DEVELOPMENT OCCURS.
BEGINNING SATURDAY MORNING...A COLD FRONT SHOULD BEGIN SLIDING INTO
THE FORECAST AREA. AHEAD OF THE FRONT...AMPLE MIXING WILL LEAD TO A
FAST RISE IN THE TEMPERATURES BEFORE THE FRONT MOVES THROUGH.
THEREFORE...HIGH TEMPERATURE FORECAST IS TRICKY BECAUSE OF QUESTIONS
ON THE DEGREE OF WARMING AND FRONT TIMING. AHEAD OF THE COLD
FRONT...A MOIST AND UNSTABLE AIRMASS WILL BE IN PLACE. THE STORM
ENVIRONMENT SHOULD BE CHARACTERIZED BY SBCAPE OF 2000-3500
J/KG...850-500 MB LAPSE RATES OF 8-9 C/KM...0-6 KM BULK SHEAR NEAR
30 KTS...INCREASING IN THE EVENING. THIS MEANS A FEW STRONG/SEVERE
STORMS ARE POSSIBLE AHEAD OF THE FRONT. THE LOCATIONS UNDER THE
HIGHEST THREAT FOR STORMS/SEVERE WEATHER LIE ALONG AND SOUTH OF A
LINE FROM HILL CITY KANSAS TO OAKLEY TO KIT CARSON COLORADO. THE
PRIMARY THREATS WILL BE LARGE HAIL AND DAMAGING WINDS. WEAK SHEAR
INDICATE STORMS MAY BE PULSE-LIKE IN NATURE BUT SOME ORGANIZATION IS
LIKELY...SIMILAR TO TODAY`S ACTIVITY. ANOTHER ITEM TO NOTE IS THAT
STORM MOVEMENT SHOULD BE ROUGHLY PARALLEL TO THE FRONT. THIS MAY
LEAD TO A FLASH FLOODING THREAT IF STORMS TRAIN ALONG THE EAST/WEST
ORIENTED COLD FRONT. STORMS SHOULD EXIT THE REGION DURING THE
EVENING AS THE FRONT CONTINUES ITS SOUTHWARD PUSH.
FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT...BELOW NORMAL TEMPERATURES
AND DRY WEATHER CAN BE ANTICIPATED. IN FACT...WE WILL LIKELY OBSERVE
A FEW LOW TEMPERATURES IN THE UPPER 40S BOTH SATURDAY AND SUNDAY
NIGHTS. THIS IS SIMILAR TO THE COLD FRONT THAT PASSED THROUGH IN
RECENT DAYS. IN ADDITION TO COOLER WEATHER...VERY DRY AIR ADVECTS IN
FROM THE NORTHWEST. DRY AIR IS ALREADY IN PLACE ACCORDING TO
OBSERVATIONS ACROSS NORTHEAST COLORADO...WYOMING AND MONTANA. THIS
FURTHERS CONFIDENCE IN COOL TEMPERATURES WITH CLEAR SKIES OVERHEAD
AND LIGHT WINDS DUE TO A PASSING SURFACE HIGH PRESSURE.
A WARMING TREND BEGINS MONDAY AS AN UPPER LEVEL RIDGE BUILDS OVER
THE REGION. WITH THE RIDGE OF HIGH PRESSURE IN PLACE AND NO
APPRECIABLE SHORTWAVE TROUGHS ROUNDING THE RIDGE...WENT WITH A DRY
FORECAST. A FEW STORMS MAY SNEAK INTO EAST COLORADO TUESDAY EVENING
BUT MOST ACTIVITY SHOULD REMAIN CONFINED TO THE COLORADO FRONT RANGE.
WEDNESDAY AND BEYOND...GUIDANCE DISAGREEMENT AND UNCERTAINTY
REGARDING SHORTWAVE TROUGH POTENTIAL AND HIGH PRESSURE RIDGE
STRENGTH REDUCE FORECAST CONFIDENCE IN PRECIPITATION CHANCES.
MAINTAINED CR_INITIALIZATION POPS WHICH SEEMED REASONABLE GIVEN THIS
TIME OF YEAR.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1136 AM MDT FRI AUG 21 2015
VFR CONDITIONS EXPECTED FOR THE 18Z TAFS. SOUTH WINDS WILL
INCREASE THROUGH THE AFTERNOON THEN DECLINE SOME DURING THE
EVENING. SCATTERED STORMS WILL MOVE EAST ACROSS THE AREA AND BE
MOST LIKELY TO IMPACT KGLD RATHER THAN KMCK LATE THIS AFTERNOON
INTO THE EVENING. MINOR FOG MAY DEVELOP OVERNIGHT INTO EARLY
MORNING FOR BOTH SITES. AT THIS TIME KGLD LOOKS MORE FAVORABLE FOR
FOG THAN KMCK. SATURDAY WINDS WILL TURN TO THE WEST THEN NORTHWEST AHEAD
OF A COLD FRONT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...BULLER
LONG TERM...RRH
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1141 AM MDT FRI AUG 21 2015
.UPDATE...
ISSUED AT 1003 AM MDT FRI AUG 21 2015
CURRENT FORECAST FOR THE AFTERNOON AND EVENING LOOKS ON TRACK
WITH THE LATEST OBSERVATIONS AND MODEL DATA. DID ADJUST THE
COVERAGE AND VALUE OF THE RAINFALL CHANCES A BIT GIVEN THE GOOD
AGREEMENT AMONG THE MODELS FOR THE STORM ACTIVITY THIS AFTERNOON.
EXPECT STORMS TO DEVELOP ALONG A SURFACE TROUGH/DRY LINE OVER THE
WESTERN PART OF THE AREA. THE STRONGEST LIFT WILL REMAIN TIED
TO THE NEARLY STATIONARY TROUGH THROUGH THE AFTERNOON...SO EXPECT
STORMS TO DEVELOP ALONG IT AND MOVE SLOWLY EAST. THE MAIN QUESTION
WILL BE HOW FAR EAST WILL THE STORMS GO BEFORE DISSIPATING SINCE
THE MAJORITY OF THE LIFT WILL REMAIN WITH THE SURFACE TROUGH.
CURRENTLY LOOKS LIKE THE MAJORITY OF THE STORMS WILL WEAKEN BY THE
TIME THEY REACH THE HIGHWAY 83 CORRIDOR...ALTHOUGH STORMS WHICH
MOVE OVER SOUTHWEST NEBRASKA MAY MAKE IT ALL THE WAY THROUGH RED
WILLOW COUNTY BEFORE DISSIPATING.
FOR THE EVENING AM NOT TOO CONFIDENT REGARDING STORMS EAST OF
HIGHWAY 25. AM THINKING ONCE THE SURFACE HEATING ENDS THE NOSE OF
THE LOW LEVEL JET WILL SERVE AS THE PRIMARY TRIGGER FOR
STORMS...WHICH WILL BE PRIMARILY WEST OF HIGHWAY 27. HOWEVER
SOUNDINGS INDICATE A FAIRLY DRY ENVIRONMENT DURING THE
EVENING WEST OF HIGHWAY 27...WHICH MAY HINDER STORM DEVELOPMENT
DESPITE THE INFLUENCE OF THE NOSE OF THE LOW LEVEL JET.
ASIDE FROM THE STORMS DID INCREASE THE WINDS DUE TO THE
STRENGTHENING LOW LEVEL JET IN THE AFTERNOON MIXING TO THE GROUND.
WEST OF THE SURFACE TROUGH THE WINDS WILL BE LIGHT DUE TO THE LOW.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 330 AM MDT FRI AUG 21 2015
FORECAST CONCERNS WILL BE THUNDERSTORM CHANCES INTO THE BEGINNING OF
THE WEEKEND AND HOW COOL TO MAKE IT SATURDAY NIGHT INTO SUNDAY
NIGHT. SATELLITE SHOWING AN AMPLIFIED/BLOCKY OVER THE PACIFIC. THIS
TRANSITIONS TO A BROAD TROUGH/WESTERLY ALOFT OVER MOST OF THE
COUNTRY. STRONG SYSTEM DIGGING INTO SOUTHWEST CANADA WITH SEVERAL
SHORTWAVE TROUGHS EMBEDDED IN THE WESTERLY FLOW.
AT JET LEVEL...MODELS DID WELL. AT MID LEVELS...THE GFS/CANADIAN AND
THE UKMET WERE DOING A LITTLE BETTER THAN THE ECMWF. THE SREF AND
ESPECIALLY THE NAM WERE NOT DOING WELL. THE GFS WAS DOING A LITTLE
BETTER THAN THE ECMWF WITH THE LOW LEVEL WIND FIELD. ALL MODELS
INITIALIZED WELL ON THE LOW LEVEL THERMAL FIELD
DIFFICULT AND UNCERTAIN PRECIPITATION FORECAST...ESPECIALLY
THROUGH THIS EVENING. CONFIDENCE IS BELOW AVERAGE FOR THE
PRECIPITATION FORECAST.
TODAY/TONIGHT...WILL HAVE TO KEEP AN EYE ON ANY LATE NIGHT/EARLY
MORNING DEVELOPMENT NEAR THE BOUNDARY JUST TO THE NORTH OF OUR
AREA. MODELS HAVE BEEN HINTING AT IT AND WILL CONTINUE TO MONITOR.
FOR YESTERDAYS THUNDERSTORMS...JUST ENOUGH MOISTURE ALONG A
BOUNDARY WITH A WEAK SHORTWAVE TROUGH WAS ABLE TO SPARK ISOLATED
THUNDERSTORMS OVER AND NEAR THE NORTHEAST PORTION OF THE AREA. NOT
TOO DIFFERENT A SETUP FOR TODAY FROM YESTERDAY. AGAIN WHAT MAKES
FORECAST UNCERTAIN IS THE MOISTURE AVAILABILITY...ESPECIALLY
ABOVE THE LOW LEVELS...WHERE DOES THE SURFACE TROUGH SETUP AND THE
WEAK/COMPLICATED MID LEVEL FORCING INVOLVED.
MODELS HAVE THE BOUNDARY PRETTY CLOSE BUT A LITTLE FURTHER WEST THAN
WHAT WAS SHOWN YESTERDAY. 700 MB SHORTWAVE EJECTS INTO THE PLAINS THIS
AFTERNOON AND IT LOOKS TO BE IN TWO PIECES. ONE PORTION GOES
ACROSS THE NORTH AND IS THE SLOWER OF THE TWO SHORTWAVE TROUGHS.
THE SECOND ONE GOES ACROSS TO OUR SOUTH AND BRUSHES THE SOUTHERN
PORTION OF THE AREA. THERE IS WEAK FORCING IN BETWEEN. ALSO THE
MODELS DIFFER ON HOW FAR EAST DURING THE DAY THEY MOVE THESE
SHORTWAVE TROUGHS.
CONVECTIVE ALLOWING MODELS ARE HAVING A DIFFICULT WITH ALL THIS. THE
ARW HAS LITTLE TO NOTHING. THE HRRR AND ESPECIALLY THE NMM DEVELOP
ROBUST CONVECTION OVER THE WESTERN PORTION OF THE AREA THIS
AFTERNOON CLOSE TO THE SURFACE TROUGH. THE 00Z NAM DID NOT INDICATE
ANYTHING BUT NOW THE 06Z NAM IS MATCHING UP WITH THE ABOVE TWO
MODELS. THE 00Z ECMWF EXPLODES CONVECTION OVER THE NORTHERN PORTION
OF THE AREA. ALL THIS TIME A RATHER STOUT EML LIES OVER THE AREA.
AFTER LOOKING AT THIS AND COLLABORATION...PULLED THE INITIATION A
LITTLE FURTHER WEST THAN BEFORE. THE PROBLEM THEN BECOMES HOW FAR
EAST TO TAKE THIS ACTIVITY. THE HRRR TAKES IT FURTHER EAST WHILE THE
REST OF THE OUTPUT THAT DID DEVELOP SOMETHING JUST KEEPS IT OVER
THE WEST AS IT EITHER DISSIPATES THE THUNDERSTORMS OR MOVES THEM
OF THE AREA TO THE NORTH OR SOUTH. SO DID LOWER POPS A LITTLE DUE
TO THIS.
IT DOES LOOK LIKE THE THUNDERSTORMS END BY 06Z. HOWEVER ELEVATED
STORMS/REDEVELOPMENT WILL NEED TO BE LOOKED AT AGAIN TO A LOW LEVEL
JET AND DECENT WARM AIR ADVECTION PATTERN ALOFT AHEAD OF ANOTHER
SHORTWAVE TROUGH. FOR THIS AFTERNOON AND EVENINGS CONVECTION...IF
STORMS DEVELOP...IT WILL BE POSSIBLE THAT THESE WILL BECOME SEVERE
DUE TO THE INSTABILITY AND LAPSE RATES INVOLVED. NO MATTER IF
STORMS DEVELOP OR NOT...BOUNDARY LAYER MOISTURE INCREASES AND AT
THE VERY LEAST A LOT OF STRATUS WILL DEVELOP WITH SOME PATCHY FOG
INVOLVED.
PRESSURE FALLS AND GRADIENT SUPPORT NEAR BREEZY OR BREEZY CONDITIONS.
GUIDANCE HAS BEEN RUNNING COOL ON MAXES HERE THE LAST FEW DAYS.
THE GFS/MAV HAS BEEN DOING THE BEST AND HAVE RAISED THE MAXES SOME.
SATURDAY/SATURDAY NIGHT...PATCHY FOG ENDS BY MID MORNING WITH THE
STRATUS LASTING A LITTLE LONGER. THERE ARE STILL DIFFERENCES IN
HOW FAST THE MODELS BRING IN THE COLD FRONT. THE NAM IS THE
SLOWEST FOLLOWED BY SREF. THE GFS/ECMWF/CANADIAN ARE THE FASTEST.
ROUGHLY IT LOOKS LIKE THE FRONT IS THROUGH THE NORTHWEST HALF OF
THE AREA BY LATE MORNING. THE FRONT THEN LOOKS TO MOVE ACROSS THE
REST OF THE AREA BY LATE AFTERNOON OR EARLY EVENING.
THE CHANCE OF THUNDERSTORMS WILL BE OVER THE SOUTHEAST PORTION OF
THE AREA IN ADVANCE OF THIS FRONT. CONTINUED THE LOW CHANCE POPS IN
THIS AREA. FRONT AND ASSOCIATED FORCING EXIT THE AREA EARLY IN
THE EVENING AND SO PRECIPITATION CUTS OFF RATHER FAST.
WINDS BEHIND THE FRONT COULD GET WINDY AND THE DAY SHIFT WILL NEED
TO LOOK AT RAISING THE WINDS EVEN MORE. DESPITE SIMILAR TIMING TO
YESTERDAYS OUTPUT...MODELS HAVE RAISED HIGH TEMPERATURES FOR THE
DAY. THE GFS...CANADIAN AND THE NAM ARE IN DECENT AGREEMENT ON
THIS. IT SEEMS THAT THE COLDER AIR DOES LAG SLIGHTLY BEHIND THE
FRONT. DID RAISE MAXES A LITTLE BUT THEY MAY NEED TO BE RAISED
EVEN MORE IN SOUTHERN LOCATIONS.
WINDS STAY UP ENOUGH TONIGHT THAT TEMPERATURES SHOULD NOT DROP
LIKE A ROCK. IF THE WINDS LET UP QUICKER...GOOD RADIATIONAL
CONDITIONS WOULD BE IN PLACE AND A LOWERING OF THE MINS WOULD BE
NEEDED.
SUNDAY/SUNDAY NIGHT...DRY PERIOD WITH POST FRONTAL COOL AIR MASS IN
PLACE. NEW GUIDANCE FOR TEMPERATURES VERY SIMILAR TO WHAT WAS IN
THERE FOR MAXES AND MADE ONLY SLIGHT ADJUSTMENTS. ONCE AGAIN FOR THE
MINS...IF WINDS END UP BEING LESS THAN CURRENTLY PREDICTED ADDITIONAL
COOLING WILL BE NEEDED.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 330 AM MDT FRI AUG 21 2015
THE EXTENDED PERIOD LOOKS TO BE MOSTLY DRY ALONG WITH NEAR TO ABOVE
NORMAL TEMPERATURES FOR THE AREA AS RIDGING INFLUENCES THE FORECAST.
ON MONDAY...AN UPPER LEVEL RIDGE CONTINUES TO BUILD INTO THE PLAINS
FOLLOWING THE SYSTEM PREDICTED TO IMPACT THE REGION THIS WEEKEND.
THE RIDGE AMPLIFIES AND MOVES EAST EARLY NEXT WEEK...WITH ITS AXIS
NEARING THE PLAINS ON WEDNESDAY. DRY CONDITIONS ARE EXPECTED DURING
THIS TIME FRAME.
MOISTURE RETURNS TO THE AREA WEDNESDAY AND THURSDAY AS A SHORTWAVE
MOVES ALONG THE PERSISTENT RIDGE. THIS DISTURBANCE LOOKS TO GENERATE
SHOWER AND THUNDERSTORM CHANCES WEDNESDAY NIGHT AND THURSDAY FOR
PORTIONS OF THE REGION.
AFTER SUNDAYS COOL DOWN...TEMPERATURES ARE EXPECTED TO QUICKLY
REBOUND IN THE EXTENDED PERIOD WITH HIGHS IN THE UPPER 80S TO LOW
90S AND LOWS IN THE UPPER 50S TO UPPER 60S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1136 AM MDT FRI AUG 21 2015
VFR CONDITIONS EXPECTED FOR THE 18Z TAFS. SOUTH WINDS WILL
INCREASE THROUGH THE AFTERNOON THEN DECLINE SOME DURING THE
EVENING. SCATTERED STORMS WILL MOVE EAST ACROSS THE AREA AND BE
MOST LIKELY TO IMPACT KGLD RATHER THAN KMCK LATE THIS AFTERNOON
INTO THE EVENING. MINOR FOG MAY DEVELOP OVERNIGHT INTO EARLY
MORNING FOR BOTH SITES. AT THIS TIME KGLD LOOKS MORE FAVORABLE FOR
FOG THAN KMCK. SATURDAY WINDS WILL TURN TO THE WEST THEN NORTHWEST AHEAD
OF A COLD FRONT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...BULLER
LONG TERM...JBH
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1019 AM MDT FRI AUG 21 2015
.UPDATE...
ISSUED AT 1003 AM MDT FRI AUG 21 2015
CURRENT FORECAST FOR THE AFTERNOON AND EVENING LOOKS ON TRACK
WITH THE LATEST OBSERVATIONS AND MODEL DATA. DID ADJUST THE
COVERAGE AND VALUE OF THE RAINFALL CHANCES A BIT GIVEN THE GOOD
AGREEMENT AMONG THE MODELS FOR THE STORM ACTIVITY THIS AFTERNOON.
EXPECT STORMS TO DEVELOP ALONG A SURFACE TROUGH/DRY LINE OVER THE
WESTERN PART OF THE AREA. THE STRONGEST LIFT WILL REMAIN TIED
TO THE NEARLY STATIONARY TROUGH THROUGH THE AFTERNOON...SO EXPECT
STORMS TO DEVELOP ALONG IT AND MOVE SLOWLY EAST. THE MAIN QUESTION
WILL BE HOW FAR EAST WILL THE STORMS GO BEFORE DISSIPATING SINCE
THE MAJORITY OF THE LIFT WILL REMAIN WITH THE SURFACE TROUGH.
CURRENTLY LOOKS LIKE THE MAJORITY OF THE STORMS WILL WEAKEN BY THE
TIME THEY REACH THE HIGHWAY 83 CORRIDOR...ALTHOUGH STORMS WHICH
MOVE OVER SOUTHWEST NEBRASKA MAY MAKE IT ALL THE WAY THROUGH RED
WILLOW COUNTY BEFORE DISSIPATING.
FOR THE EVENING AM NOT TOO CONFIDENT REGARDING STORMS EAST OF
HIGHWAY 25. AM THINKING ONCE THE SURFACE HEATING ENDS THE NOSE OF
THE LOW LEVEL JET WILL SERVE AS THE PRIMARY TRIGGER FOR
STORMS...WHICH WILL BE PRIMARILY WEST OF HIGHWAY 27. HOWEVER
SOUNDINGS INDICATE A FAIRLY DRY ENVIRONMENT DURING THE
EVENING WEST OF HIGHWAY 27...WHICH MAY HINDER STORM DEVELOPMENT
DESPITE THE INFLUENCE OF THE NOSE OF THE LOW LEVEL JET.
ASIDE FROM THE STORMS DID INCREASE THE WINDS DUE TO THE
STRENGTHENING LOW LEVEL JET IN THE AFTERNOON MIXING TO THE GROUND.
WEST OF THE SURFACE TROUGH THE WINDS WILL BE LIGHT DUE TO THE LOW.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 330 AM MDT FRI AUG 21 2015
FORECAST CONCERNS WILL BE THUNDERSTORM CHANCES INTO THE BEGINNING OF
THE WEEKEND AND HOW COOL TO MAKE IT SATURDAY NIGHT INTO SUNDAY
NIGHT. SATELLITE SHOWING AN AMPLIFIED/BLOCKY OVER THE PACIFIC. THIS
TRANSITIONS TO A BROAD TROUGH/WESTERLY ALOFT OVER MOST OF THE
COUNTRY. STRONG SYSTEM DIGGING INTO SOUTHWEST CANADA WITH SEVERAL
SHORTWAVE TROUGHS EMBEDDED IN THE WESTERLY FLOW.
AT JET LEVEL...MODELS DID WELL. AT MID LEVELS...THE GFS/CANADIAN AND
THE UKMET WERE DOING A LITTLE BETTER THAN THE ECMWF. THE SREF AND
ESPECIALLY THE NAM WERE NOT DOING WELL. THE GFS WAS DOING A LITTLE
BETTER THAN THE ECMWF WITH THE LOW LEVEL WIND FIELD. ALL MODELS
INITIALIZED WELL ON THE LOW LEVEL THERMAL FIELD
DIFFICULT AND UNCERTAIN PRECIPITATION FORECAST...ESPECIALLY
THROUGH THIS EVENING. CONFIDENCE IS BELOW AVERAGE FOR THE
PRECIPITATION FORECAST.
TODAY/TONIGHT...WILL HAVE TO KEEP AN EYE ON ANY LATE NIGHT/EARLY
MORNING DEVELOPMENT NEAR THE BOUNDARY JUST TO THE NORTH OF OUR
AREA. MODELS HAVE BEEN HINTING AT IT AND WILL CONTINUE TO MONITOR.
FOR YESTERDAYS THUNDERSTORMS...JUST ENOUGH MOISTURE ALONG A
BOUNDARY WITH A WEAK SHORTWAVE TROUGH WAS ABLE TO SPARK ISOLATED
THUNDERSTORMS OVER AND NEAR THE NORTHEAST PORTION OF THE AREA. NOT
TOO DIFFERENT A SETUP FOR TODAY FROM YESTERDAY. AGAIN WHAT MAKES
FORECAST UNCERTAIN IS THE MOISTURE AVAILABILITY...ESPECIALLY
ABOVE THE LOW LEVELS...WHERE DOES THE SURFACE TROUGH SETUP AND THE
WEAK/COMPLICATED MID LEVEL FORCING INVOLVED.
MODELS HAVE THE BOUNDARY PRETTY CLOSE BUT A LITTLE FURTHER WEST THAN
WHAT WAS SHOWN YESTERDAY. 700 MB SHORTWAVE EJECTS INTO THE PLAINS THIS
AFTERNOON AND IT LOOKS TO BE IN TWO PIECES. ONE PORTION GOES
ACROSS THE NORTH AND IS THE SLOWER OF THE TWO SHORTWAVE TROUGHS.
THE SECOND ONE GOES ACROSS TO OUR SOUTH AND BRUSHES THE SOUTHERN
PORTION OF THE AREA. THERE IS WEAK FORCING IN BETWEEN. ALSO THE
MODELS DIFFER ON HOW FAR EAST DURING THE DAY THEY MOVE THESE
SHORTWAVE TROUGHS.
CONVECTIVE ALLOWING MODELS ARE HAVING A DIFFICULT WITH ALL THIS. THE
ARW HAS LITTLE TO NOTHING. THE HRRR AND ESPECIALLY THE NMM DEVELOP
ROBUST CONVECTION OVER THE WESTERN PORTION OF THE AREA THIS
AFTERNOON CLOSE TO THE SURFACE TROUGH. THE 00Z NAM DID NOT INDICATE
ANYTHING BUT NOW THE 06Z NAM IS MATCHING UP WITH THE ABOVE TWO
MODELS. THE 00Z ECMWF EXPLODES CONVECTION OVER THE NORTHERN PORTION
OF THE AREA. ALL THIS TIME A RATHER STOUT EML LIES OVER THE AREA.
AFTER LOOKING AT THIS AND COLLABORATION...PULLED THE INITIATION A
LITTLE FURTHER WEST THAN BEFORE. THE PROBLEM THEN BECOMES HOW FAR
EAST TO TAKE THIS ACTIVITY. THE HRRR TAKES IT FURTHER EAST WHILE THE
REST OF THE OUTPUT THAT DID DEVELOP SOMETHING JUST KEEPS IT OVER
THE WEST AS IT EITHER DISSIPATES THE THUNDERSTORMS OR MOVES THEM
OF THE AREA TO THE NORTH OR SOUTH. SO DID LOWER POPS A LITTLE DUE
TO THIS.
IT DOES LOOK LIKE THE THUNDERSTORMS END BY 06Z. HOWEVER ELEVATED
STORMS/REDEVELOPMENT WILL NEED TO BE LOOKED AT AGAIN TO A LOW LEVEL
JET AND DECENT WARM AIR ADVECTION PATTERN ALOFT AHEAD OF ANOTHER
SHORTWAVE TROUGH. FOR THIS AFTERNOON AND EVENINGS CONVECTION...IF
STORMS DEVELOP...IT WILL BE POSSIBLE THAT THESE WILL BECOME SEVERE
DUE TO THE INSTABILITY AND LAPSE RATES INVOLVED. NO MATTER IF
STORMS DEVELOP OR NOT...BOUNDARY LAYER MOISTURE INCREASES AND AT
THE VERY LEAST A LOT OF STRATUS WILL DEVELOP WITH SOME PATCHY FOG
INVOLVED.
PRESSURE FALLS AND GRADIENT SUPPORT NEAR BREEZY OR BREEZY CONDITIONS.
GUIDANCE HAS BEEN RUNNING COOL ON MAXES HERE THE LAST FEW DAYS.
THE GFS/MAV HAS BEEN DOING THE BEST AND HAVE RAISED THE MAXES SOME.
SATURDAY/SATURDAY NIGHT...PATCHY FOG ENDS BY MID MORNING WITH THE
STRATUS LASTING A LITTLE LONGER. THERE ARE STILL DIFFERENCES IN
HOW FAST THE MODELS BRING IN THE COLD FRONT. THE NAM IS THE
SLOWEST FOLLOWED BY SREF. THE GFS/ECMWF/CANADIAN ARE THE FASTEST.
ROUGHLY IT LOOKS LIKE THE FRONT IS THROUGH THE NORTHWEST HALF OF
THE AREA BY LATE MORNING. THE FRONT THEN LOOKS TO MOVE ACROSS THE
REST OF THE AREA BY LATE AFTERNOON OR EARLY EVENING.
THE CHANCE OF THUNDERSTORMS WILL BE OVER THE SOUTHEAST PORTION OF
THE AREA IN ADVANCE OF THIS FRONT. CONTINUED THE LOW CHANCE POPS IN
THIS AREA. FRONT AND ASSOCIATED FORCING EXIT THE AREA EARLY IN
THE EVENING AND SO PRECIPITATION CUTS OFF RATHER FAST.
WINDS BEHIND THE FRONT COULD GET WINDY AND THE DAY SHIFT WILL NEED
TO LOOK AT RAISING THE WINDS EVEN MORE. DESPITE SIMILAR TIMING TO
YESTERDAYS OUTPUT...MODELS HAVE RAISED HIGH TEMPERATURES FOR THE
DAY. THE GFS...CANADIAN AND THE NAM ARE IN DECENT AGREEMENT ON
THIS. IT SEEMS THAT THE COLDER AIR DOES LAG SLIGHTLY BEHIND THE
FRONT. DID RAISE MAXES A LITTLE BUT THEY MAY NEED TO BE RAISED
EVEN MORE IN SOUTHERN LOCATIONS.
WINDS STAY UP ENOUGH TONIGHT THAT TEMPERATURES SHOULD NOT DROP
LIKE A ROCK. IF THE WINDS LET UP QUICKER...GOOD RADIATIONAL
CONDITIONS WOULD BE IN PLACE AND A LOWERING OF THE MINS WOULD BE
NEEDED.
SUNDAY/SUNDAY NIGHT...DRY PERIOD WITH POST FRONTAL COOL AIR MASS IN
PLACE. NEW GUIDANCE FOR TEMPERATURES VERY SIMILAR TO WHAT WAS IN
THERE FOR MAXES AND MADE ONLY SLIGHT ADJUSTMENTS. ONCE AGAIN FOR THE
MINS...IF WINDS END UP BEING LESS THAN CURRENTLY PREDICTED ADDITIONAL
COOLING WILL BE NEEDED.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 330 AM MDT FRI AUG 21 2015
THE EXTENDED PERIOD LOOKS TO BE MOSTLY DRY ALONG WITH NEAR TO ABOVE
NORMAL TEMPERATURES FOR THE AREA AS RIDGING INFLUENCES THE FORECAST.
ON MONDAY...AN UPPER LEVEL RIDGE CONTINUES TO BUILD INTO THE PLAINS
FOLLOWING THE SYSTEM PREDICTED TO IMPACT THE REGION THIS WEEKEND.
THE RIDGE AMPLIFIES AND MOVES EAST EARLY NEXT WEEK...WITH ITS AXIS
NEARING THE PLAINS ON WEDNESDAY. DRY CONDITIONS ARE EXPECTED DURING
THIS TIME FRAME.
MOISTURE RETURNS TO THE AREA WEDNESDAY AND THURSDAY AS A SHORTWAVE
MOVES ALONG THE PERSISTENT RIDGE. THIS DISTURBANCE LOOKS TO GENERATE
SHOWER AND THUNDERSTORM CHANCES WEDNESDAY NIGHT AND THURSDAY FOR
PORTIONS OF THE REGION.
AFTER SUNDAYS COOL DOWN...TEMPERATURES ARE EXPECTED TO QUICKLY
REBOUND IN THE EXTENDED PERIOD WITH HIGHS IN THE UPPER 80S TO LOW
90S AND LOWS IN THE UPPER 50S TO UPPER 60S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 540 AM MDT FRI AUG 21 2015
AT THIS TIME VFR CONDITIONS ARE EXPECTED AT BOTH SITES. SOUTHERLY
WINDS WILL INCREASE THIS MORNING AND BECOME GUSTY. THESE GUSTY
WINDS WILL LAST WELL INTO THE NIGHT WITH SUSTAINED SPEEDS OF 14 TO
17 KNOTS WITH GUSTS 22 TO 25 KNOTS. THUNDERSTORMS ARE EXPECTED TO
DEVELOP THIS AFTERNOON AND EVENING BUT MODEL DIFFERENCES ON TIME
AND AREA OF INITIATION MAKE THINGS A LITTLE UNCERTAIN.
AT THIS TIME ONLY FEEL COMFORTABLE ENOUGH TO PUT IN A VCTS AT BOTH
SITES WITH KGLD STARTING AT 21Z AND KMCK AT 00Z. THUNDERSTORMS ARE
EXPECTED TO BE DONE BY 03Z. LATER IN THE NIGHT SOME FOG IS
EXPECTED VISIBILITIES STAYING ABOVE MVFR.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...BULLER
LONG TERM...JBH
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1238 PM CDT FRI AUG 21 2015
.DISCUSSION...
FOR THE 21/18Z TAF ISSUANCE.
&&
.AVIATION...
NUMEROUS SHOWERS AND THUNDERSTORMS WILL CONTINUE TO SPREAD NORTH
DURING THE AFTERNOON HOURS. MAIN ACTIVITY HAS MOVED NORTH OF
KBPT...SO WILL JUST MENTION VCSH THERE. WILL HAVE PREVAILING
SHOWERS WITH VCTS FOR KLCH/KLFT/KARA THROUGH MID AFTERNOON
21/20Z...WITH ACTIVITY BEGINNING AT KAEX AROUND 21/19Z. UPPER
LEVEL DISTURBANCE WILL MOVE OFF TO THE NORTH LATE THIS
AFTERNOON...AND WITH LOSS OF DAYTIME HEATING...MOST OF THE
ACTIVITY WILL DISSIPATE BY 22/01Z...WITH VFR CONDITIONS THEN
EXPECTED FOR THE NIGHT...WITH EXCEPTION OF KAEX...WHERE SOME MVFR
PATCHY FOG MAY OCCUR NEAR DAYBREAK.
RUA
&&
.PREV DISCUSSION... /ISSUED 954 AM CDT FRI AUG 21 2015/
DISCUSSION...
NUM SHRA/TSRA BEGINNING TO MOVE ASHORE SE TX/SW LA IN ASSOCIATION
WITH THE NEXT UPPER LEVEL IMPULSE MOVING NE ACROSS THE TX COAST
THIS MORNING. THUS...HAD TO BUMP UP POPS AND QPF SIGNIFICANTLY
THIS MORNING...CLOSE TO HRRR GUIDANCE WHICH HAS A GOOD HANDLE ON
THIS SITUATION. ALSO INCLUDED HEAVY RAINFALL POSSIBLE AS THESE
WILL BE SOMEWHAT SLOWER MOVING. WITH THE INCREASED CLOUD COVER...AGREE
WITH HRRR AND LOWERED TEMPS ACROSS SE TX/SW LA. OTHERWISE...BUMPED
UP WINDS A BIT TO 10-15 KTS ACROSS THE COASTAL WATERS THIS MORNING
AS THIS SYSTEM MOVES ACROSS THE REGION. THATS ABOUT IT. UPDATES
ALREADY OUT.
DML
PREV DISCUSSION... /ISSUED 716 AM CDT FRI AUG 21 2015/
DISCUSSION...
FOR THE 12Z TAF PACKAGE.
AVIATION...
QUIETER NIGHT AND MORNING VERSUS THE PREVIOUS COUPLE OF
DAYS...THOUGH CONVECTIVE ACTIVITY HAS BEEN ON THE INCREASE OVER THE
COASTAL WATERS FOR THE PAST COUPLE OF HRS...ESPECIALLY OFF THE SE
TX/SW LA COASTS. LATEST HIGH RESOLUTION MODEL DATA DEPICTS THE
WELL DEFINED SHORTWAVE OVER THE MIDDLE TX COAST...AND ITS
ASSOCIATED CONVECTION...LIFTING NE THROUGH THE AREA LATER THIS
MORNING INTO THE AFTERNOON. VCTS WAS INSERTED AT EACH SITE BASED
ON THIS THINKING. RECENT PLUNGE IN VSBY AT KAEX IS EXPECTED TO BE
SHORT LIVED...PERHAPS AN HR OR SO. WILL CONTINUE TO MONITOR FOR A
POSSIBLE AMD. VFR EXPECTED TO PREVAIL OUTSIDE OF CONVECTION...AND
BY THIS EVENING AS ACTIVITY LIFTS NE OF THE AREA.
13
PREV DISCUSSION... /ISSUED 452 AM CDT FRI AUG 21 2015/
SYNOPSIS...
A NEARLY STATIONARY W-E ORIENTED SFC FRONT EXTENDS FM NE TX ACRS
NRN LA INTO CNTL MS. THE FRONT HAS BECOME A LITTLE MORE DIFFUSE
THE PAST SEVERAL HOURS...AS DEWPOINTS ALONG AND SOUTH OF THE
FRONTAL ZONE ARE IN THE LOWER TO MIDDLE 70S WITH COOLER AND DRIER
AIR LOCATED WELL BEHIND THE BOUNDARY ACRS NRN/CNTL ARK AND FAR N
MS.
THE LATEST WV IMAGERY AND UA ANALYSIS SHOWS MOISTURE ALOFT BEING
FUNNELED OVER THE REGION ON SWLY FLOW BETWEEN A TROF/WEAKNESS
OVER THE SRN PLAINS AND AN UPR RIDGE ACRS THE GULF OF MEXICO.
A LITTLE LESS CONVECTIVE ACTIVITY SO FAR TODAY THAN THE PAST
COUPLE OF MORNINGS...ALTHOUGH REGIONAL RADAR MOSAIC SHOWS SCT
SHOWERS AND A FEW TSTMS DEVELOPING OFF THE UPR TX COAST AND OVER
GALVESTON BAY WITH MORE ISOLATED ACTIVITY OVER OUR COASTAL WATERS
ZONES. FURTHER INLAND...A BAND OF LT TO MDT RAIN WAS LOCATED NEAR
THE FRONTAL BOUNDARY...FM JUST NORTH OF THE LAKES REGION OF SE TX
INTO PORTIONS OF WRN LA.
DISCUSSION...
THE FRONT WILL GRADUALLY WEAKEN AS IT LIFTS BACK NORTH LATER
TODAY. HOWEVER...ABUNDANT MOISTURE REMAINS OVER THE AREA AND WITH
THE LINGERING DISTURBANCE OR WEAKNESS ALOFT...EXPECT SCT
CONVECTION TO AGAIN DEVELOP TODAY. THIS ACTIVITY IS EXPECTED TO BE
MORE DIURNALLY DRIVEN...WITH THE SEABREEZE BOUNDARY AND THE
DISSIPATING FRONT FOCUSING CONVECTIVE DEVELOPMENT AS DAYTIME
HEATING GETS UNDERWAY. PRECIP WATER VALUES WILL REMAIN NEAR 2
INCHES...AND THIS SHOULD AGAIN ALLOW TSTMS TO BE EFFICIENT
RAINFALL PRODUCERS WITH HIGH RAIN RATES AT TIMES. CLOUDY SKIES ON
THURSDAY HELPED TO KEEP TEMPERATURES IN THE 80S...WITH SOME
LOCATIONS ONLY REACHING THE LOWER 80S. WHILE THIS MAY BE THE CASE
AGAIN TODAY...THINK CLOUD AND CONVECTIVE COVERAGE WILL BE A LITTLE
LESS AND OCCASIONAL PEEKS OF SUN SHOULD ALLOW TEMPERATURES TO RISE
TO NEAR 90 IN THE AFTN.
MEANWHILE...THE WEAKNESS ALOFT WILL MORE OR LESS LINGER OVER THE
REGION THROUGH THE WEEKEND EVEN AS THE HIGH OVER THE ERN GULF
BEGINS TO BUILD WEST. THERE WILL STILL BE A DAILY CHC FOR SHOWERS
OR STORMS SATURDAY AND SUNDAY BUT COVERAGE WILL BE LOWER AS
SLIGHTLY DRIER AIR BEGINS TO WORK INTO THE REGION. WITH LESS
CONVECTION AND CLOUDS...AFTN TEMPERATURES WILL BEGIN A WARMING
TREND.
BY EARLY NEXT WEEK...THE HIGH WILL RETROGRADE FURTHER WEST AS A
SHORTWAVE TROF DIGS OVER THE ERN STATES...WITH THE SYSTEM
GRADUALLY AMPLIFYING OVER THE CONUS. THIS WILL LEAD TO A DEEPENING
NLY FLOW THAT WILL PUSH A SFC FRONT INTO THE AREA BY TUESDAY. RAIN
CHCS WILL BUMP BACK UP IN ADVANCE OF THE FRONT MONDAY INTO
TUESDAY. GLOBAL MODELS ARE IN GENERAL AGREEMENT REGARDING THE
DEVELOPMENT OF THIS AMPLIFIED SYSTEM AND ASSOCIATED SFC
FROPA...AND KEEPING THE AREA UNDER A NLY FLOW ALOFT THROUGH THE
LATTER PART OF THE WEEK. SHOULD THIS SCENARIO PAN OUT...DRIER MORE
COMFORTABLE CONDITIONS CAN BE EXPECTED FROM WEDNESDAY THROUGH
FRIDAY WITH SLIGHTLY BELOW NORMAL LOWS IN THE UPPER 60S TO LOWER
70S AND HIGHS NEAR NORMAL IN THE LOWER 90S.
24
MARINE...
A LT TO OCCASIONALLY MDT ONSHORE FLOW AND LOW SEAS WILL PERSIST
THROUGH EARLY NEXT WEEK AS HIGH PRES CONTINUES TO RIDGE OVER THE
GULF. A LINGERING DISTURBANCE OVER THE REGION WILL ALLOW FOR SCT
SHOWERS AND TSTMS TODAY...BUT RAIN CHCS WILL DECREASE OVER THE
WEEKEND AS HIGH PRES BUILDS ALOFT. A FRONT WILL MOVE SOUTH INTO
THE AREA BY LATE MONDAY INTO TUESDAY...BRINGING ANOTHER CHC FOR
SHOWERS OR TSTMS. AT THIS TIME...MODEL GUIDANCE SHOWS THIS FRONT
MOVING SOUTH OVER THE COASTAL WATERS ZONES...WITH OFFSHORE FLOW
AND DRIER WEATHER POSSIBLE FOR THE MIDDLE AND LATTER PART OF NEXT
WEEK.
24
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 92 74 94 75 / 70 20 30 10
LCH 85 77 90 77 / 60 20 30 10
LFT 87 76 91 76 / 70 20 30 10
BPT 84 77 90 77 / 80 20 30 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AVIATION...07
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
402 PM EDT FRI AUG 21 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 316 PM EDT FRI AUG 21 2015
WEATHER REMAINS QUIET INTO SATURDAY WITH WARMING TREND. IN THE REAL
NEAR TERM...TRYING TO FIGURE OUT IF THE HRRR AND RAP SHOWING A FEW
BLIPS ON THE MODELED REFLECTIVITY ARE REALISTIC. REGIONAL RADAR LOOP
HAS SHOWN ISOLD ECHOES OVER NORTHERN WI...BUT ONLY OBS SHOWING LGT
RAIN ARE OVER WCNTRL WI CLOSER TO MUCAPES OF A FEW HUNDRED J/KG.
ANOTHER AGITATED AREA OF MID CLOUDS AND ISOLD SHRA IS OVER MN
ARROWHEAD. MAIN SHORTWAVE DRIVING THAT AREA OF WX IS LIFTING OVER
NORTHERN ONTARIO INSTEAD OF TOWARD UPR MICHIGAN. OVER THE CWA REST
OF THIS AFTN...HRRR AND RAP SOUNDINGS SHOW NARROW LAYER OF MOISTURE
AROUND H7 WITH DRY AIR BLO AND ABOVE. GOING TO KEEP IT DRY WITH JUST
INCREASING MID CLOUDS LATE THIS AFTN INTO THE EVENING.
FOR REST OF SHORT TERM...STRONG UPPER LEVEL TROUGH OVER SOUTHERN
BRITISH COLUMBIA THIS AFTN DIGS ACROSS ROCKIES OF ALBERTA AND
MONTANA TONIGHT INTO SATURDAY MORNING WITH SFC TROUGH OVER MONTANA
THIS AFTN DEEPENING TO A 995-1000MB SFC LOW OVER DAKOTAS BY 12Z
SATURDAY. SINCE SFC LOW AND COLD FRONT REMAIN TO THE WEST OF UPR
MICHIGAN THROUGH EARLY SATURDAY EVENING...APPEARS TO BE A
DRY...WARM...AND WINDY DAY IN THE WARM SECTOR OF THE SFC LOW. WINDS
HAVE POTENTIAL TO BE QUITE GUSTY WITH EASILY 25-30 KTS IN THE MIXED
LAYER ON SATURDAY AFTN. IN ADDITION...PRESSURE GRADIENT WILL BE
TIGHT AS UPR MICHIGAN IS BETWEEN THE APPROACHING SFC LOW AND
DEPARTING HIGH OVER THE LOWER GREAT LAKES. DECENT AGREEMENT FM
NAM/GFS/GEM-REGIONAL ON THE WINDS/WIND GUSTS FOR SATURDAY. COULD SEE
WIND GUSTS 30 TO POSSIBLY 40 MPH DURING PEAK HEATING ON SATURDAY
AFTN.
THERE IS A CAVEAT FOR THE MIXING STRENGTH THOUGH. NOT A LOT OF CLOUD
COVER EXPECTED AS MOST MID CLOUDS THAT MOVE THROUGH INTO EARLY THIS
EVENING WILL BE NORTH AND EAST OF THE AREA ON SATURDY. YET...LIKELY
WILL SEE FILTERED OR DIMMED SUNSHINE AS WIDESPREAD AREA OF SMOKE
ALOFT OVER THE ROCKIES AND PLAINS TODAY /25KFT AGL PER MANUAL SFC
OBS FM DAKOTAS TO MINNESOTA/ MOVES OVER THE UPPER GREAT LAKES BASED
ON EXPECTED WINDS IN THE SMOKE LAYER /H4-H3/. ALWAYS TOUGH TO
PREDICT EXACT COVERAGE AND THICKNESS OF SMOKE LAYER...BUT GIVEN ALL
THE SMOKE UPSTREAM THIS AFTN...TRENDED HIGHER ON THE SKY COVER TO AT
LEAST GO PARTLY CLOUDY INSTEAD OF SUNNY. DURING OTHER BOUTS EARLIER
THIS SUMMER WITH SMOKE ALOFT...MIXING WAS HELD DOWN MORE THAN WHAT
YOU WOULD NORMALLY EXPECT...SO THAT MAY OCCUR AGAIN. BASED ON
FORECAST H85 TEMPS OF 16-18C...TEMPS SHOULD REACH THE 80S AWAY FM
LAKE MICHIGAN. CAPPED READINGS IN THE LOW TO MID 80S...WARMEST ALONG
LK SUPERIOR DUE TO STRONG/GUSTY SOUTH WINDS PROVIDING DOWNSLOPING
WARMING. TEMPS NEAR LK MICHIGAN WILL REACH UPPER 70S. WILL BE BUMPY
AGAIN FOR WINDS/WAVES ON NORTHERN LK MICHIGAN ESPECIALLY ON SATURDAY
AFTN DUE TO THE INCREASING SOUTH WINDS. PROBABLY WILL NEED ANOTHER
SMALL CRAFT ADVISORY FOR THE MARINE INTERESTS.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 401 PM EDT FRI AUG 21 2015
THE END OF THE WEEKEND WILL BE FAIRLY ACTIVE WEATHER WISE...WITH
ANOTHER AUTUMN LIKE COLD FRONT MOVING THROUGH THE AREA ON SUNDAY.
THE MODELS ARE IN GOOD AGREEMENT ON TIMING OF THE FRONTAL PASSAGE
ACROSS THE AREA BEING SUNDAY MORNING...WITH MUCH COOLER AIR MOVING
ACROSS THE AREA LATER SUNDAY NIGHT INTO MONDAY AS THE UPPER LOW
SETTLES JUST NORTH OF LAKE SUPERIOR. AS SUCH...WILL KEEP LIKELY POPS
SPREADING WEST TO EAST LATER SATURDAY NIGHT INTO SUNDAY MORNING. DUE
TO THE TIMING OF THE FRONTAL PASSAGE DURING THE NIGHT AND EARLY
MORNING HOURS...DO NOT EXPECT WIDESPREAD THUNDERSTORM ACTIVITY.
HOWEVER...CANNOT RULE OUT STORMS DEVELOPING OVER MN EARLY SAT
EVENING WITH THE RESIDUAL MOVING INTO UPPER MI OVERNIGHT. AS
SUCH...WILL KEEP THUNDER CHANCES IN THE FORECAST AHEAD OF THE FRONT.
AFTER FROPA...EXPECT SCATTERED RAIN SHOWERS IN THE CYCLONIC
FLOW...ALTHOUGH THERE WILL LIKELY BE A LULL IN THE PCPN IMMEDIATELY
BEHIND THE COLD FRONT SUNDAY IN THE DRY SLOT. BEST CHANCES FOR
SHOWER ACTIVITY WILL BE LATER SUNDAY NIGHT INTO MONDAY DOWNWIND OF
LAKE SUPERIOR WHERE SOME LAKE EFFECT RAIN IS POSSIBLE DUE TO 850MB
TEMPS DROPPING TO +4C YIELDING LAKE INDUCED INSTABILITY WITH WATER
TEMPS AROUND +15C ESPECIALLY ACROSS THE WESTERN BASIN. AS
SUCH...WILL MAINTAIN NUMEROUS RAIN SHOWERS FOR SUNDAY NIGHT AND
MONDAY FOR NORTHWEST UPPER MICHIGAN AND SCATTERED SHOWERS ELSEWHERE.
TEMPERATURES ON SUNDAY WILL LIKELY DROP DURING THE DAY WHILE TEMPS
ON MONDAY WILL BE LUCKY TO RISE OUT OF THE 50S. IN FACT...WITH 850MB
TEMPS BEING SO COLD...IF IT REMAINS CLOUDY ALL DAY THERE MAY BE SPOT
OR TWO THAT STAYS IN THE UPPER 40S/LOWER 50S ON MONDAY.
REGARDLESS...MONDAY WILL FEEL QUITE LIKE AUTUMN WITH BREEZY
CONDITIONS AND COOL TEMPERATURES.
WITH THE UPPER LOW BECOME CLOSED OFF NORTH OF THE AREA...WE WILL SEE
PERSISTING DEEP CYCLONIC NW FLOW THROUGH TUESDAY WITH DEEP MOISTURE
REMAINING ACROSS THE AREA. WILL NEED TO MAINTAIN SCATTERED SHOWERS
MONDAY NIGHT CLOSER TO LAKE SUPERIOR...THEN SLOWLY TAPERING FROM
WEST TO EAST DURING THE DAY ON TUESDAY AS THE UPPER LOW IS FORECAST
TO MOVE EAST YIELDING TO CONFLUENT NW FLOW ALOFT. QUIET BUT STILL
COOL WEATHER EXPECTED ON WEDNESDAY WITH HIGH PRESSURE IN CONTROL AND
UPPER HEIGHTS RISE. NEXT CHANCE FOR PRECIPITATION WILL BE LATE
THURSDAY INTO FRIDAY MORNING WITH THE NEXT SYSTEM MOVING THROUGH THE
NW FLOW ALOFT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 215 PM EDT FRI AUG 21 2015
VFR CONDITIONS WILL PERSIST THROUGH THE TAF PERIOD. SCATTERED MID
CLOUDS THIS AFTN AND A THICK SMOKE LAYER ALOFT TONIGHT INTO
SATURDAY. GUSTY SOUTH WINDS AT KIWD REST OF THE AFTN WILL GIVE WAY
TO LOW-LEVEL WIND SHEAR BY MIDNIGHT TONIGHT AS WINDS DIMINISH AT THE
SFC. WINDS WILL ALSO BECOME GUSTY FOR A TIME AT KSAW THIS AFTN AS
WELL. EXPECT STRONG AND GUSTY SOUTH WINDS AT ALL TAF SITES ON
SATURDAY ONCE LOW-LEVEL INVERSION BREAKS BY MID MORNING. WIND GUSTS
SATURDAY AFTN COULD TOP OUT NEAR 30 KTS AT KIWD AND KSAW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 316 PM EDT FRI AUG 21 2015
S WINDS INCREASE TO 25 KTS TONIGHT UNDER SHARPENING PRES GRADIENT
BETWEEN THE DEPARTING RIDGE AND A DEEP LOW PRESSURE SYSTEM MOVING
FROM THE NORTHERN PLAINS INTO ONTARIO. MAY SEE GUSTS TO 30 KTS OVER
EASTERN LK SUPERIOR ON SATURDAY AFTN. STEADY S WINDS WILL VEER
TOWARD THE W FOLLOWING A COLD FRONTAL PASSAGE ON LATE SAT NIGHT/SUN
AND INCREASE UP TO 30 KTS. DEPENDING ON THE INTENSITY OF A LOW
PRESSURE SYSTEM MOVING SLOWLY NE THRU ONTARIO...THERE COULD BE SOME
MARGINAL GALES TO 35 KTS AT TIMES ON SUN INTO MON WITH THE ARRIVAL
OF COOLER AIR/MORE DESTABILIZATION OVER THE RELATIVELY WARM LAKE
WATERS AS THE FLOW CONTINUES TO VEER TO THE NW UNDER TIGHT PRES
GRADIENT AHEAD OF APPROACHING HI PRES RIDGE FROM THE NORTHERN
PLAINS. AS THE HI MOVES CLOSER AND THE GRADIENT SLACKENS...EXPECT
WINDS TO DIMINISH LATER TUE INTO WED.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...MRD
AVIATION...JLA
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
317 PM EDT FRI AUG 21 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 316 PM EDT FRI AUG 21 2015
WEATHER REMAINS QUIET INTO SATURDAY WITH WARMING TREND. IN THE REAL
NEAR TERM...TRYING TO FIGURE OUT IF THE HRRR AND RAP SHOWING A FEW
BLIPS ON THE MODELED REFLECTIVITY ARE REALISTIC. REGIONAL RADAR LOOP
HAS SHOWN ISOLD ECHOES OVER NORTHERN WI...BUT ONLY OBS SHOWING LGT
RAIN ARE OVER WCNTRL WI CLOSER TO MUCAPES OF A FEW HUNDRED J/KG.
ANOTHER AGITATED AREA OF MID CLOUDS AND ISOLD SHRA IS OVER MN
ARROWHEAD. MAIN SHORTWAVE DRIVING THAT AREA OF WX IS LIFTING OVER
NORTHERN ONTARIO INSTEAD OF TOWARD UPR MICHIGAN. OVER THE CWA REST
OF THIS AFTN...HRRR AND RAP SOUNDINGS SHOW NARROW LAYER OF MOISTURE
AROUND H7 WITH DRY AIR BLO AND ABOVE. GOING TO KEEP IT DRY WITH JUST
INCREASING MID CLOUDS LATE THIS AFTN INTO THE EVENING.
FOR REST OF SHORT TERM...STRONG UPPER LEVEL TROUGH OVER SOUTHERN
BRITISH COLUMBIA THIS AFTN DIGS ACROSS ROCKIES OF ALBERTA AND
MONTANA TONIGHT INTO SATURDAY MORNING WITH SFC TROUGH OVER MONTANA
THIS AFTN DEEPENING TO A 995-1000MB SFC LOW OVER DAKOTAS BY 12Z
SATURDAY. SINCE SFC LOW AND COLD FRONT REMAIN TO THE WEST OF UPR
MICHIGAN THROUGH EARLY SATURDAY EVENING...APPEARS TO BE A
DRY...WARM...AND WINDY DAY IN THE WARM SECTOR OF THE SFC LOW. WINDS
HAVE POTENTIAL TO BE QUITE GUSTY WITH EASILY 25-30 KTS IN THE MIXED
LAYER ON SATURDAY AFTN. IN ADDITION...PRESSURE GRADIENT WILL BE
TIGHT AS UPR MICHIGAN IS BETWEEN THE APPROACHING SFC LOW AND
DEPARTING HIGH OVER THE LOWER GREAT LAKES. DECENT AGREEMENT FM
NAM/GFS/GEM-REGIONAL ON THE WINDS/WIND GUSTS FOR SATURDAY. COULD SEE
WIND GUSTS 30 TO POSSIBLY 40 MPH DURING PEAK HEATING ON SATURDAY
AFTN.
THERE IS A CAVEAT FOR THE MIXING STRENGTH THOUGH. NOT A LOT OF CLOUD
COVER EXPECTED AS MOST MID CLOUDS THAT MOVE THROUGH INTO EARLY THIS
EVENING WILL BE NORTH AND EAST OF THE AREA ON SATURDY. YET...LIKELY
WILL SEE FILTERED OR DIMMED SUNSHINE AS WIDESPREAD AREA OF SMOKE
ALOFT OVER THE ROCKIES AND PLAINS TODAY /25KFT AGL PER MANUAL SFC
OBS FM DAKOTAS TO MINNESOTA/ MOVES OVER THE UPPER GREAT LAKES BASED
ON EXPECTED WINDS IN THE SMOKE LAYER /H4-H3/. ALWAYS TOUGH TO
PREDICT EXACT COVERAGE AND THICKNESS OF SMOKE LAYER...BUT GIVEN ALL
THE SMOKE UPSTREAM THIS AFTN...TRENDED HIGHER ON THE SKY COVER TO AT
LEAST GO PARTLY CLOUDY INSTEAD OF SUNNY. DURING OTHER BOUTS EARLIER
THIS SUMMER WITH SMOKE ALOFT...MIXING WAS HELD DOWN MORE THAN WHAT
YOU WOULD NORMALLY EXPECT...SO THAT MAY OCCUR AGAIN. BASED ON
FORECAST H85 TEMPS OF 16-18C...TEMPS SHOULD REACH THE 80S AWAY FM
LAKE MICHIGAN. CAPPED READINGS IN THE LOW TO MID 80S...WARMEST ALONG
LK SUPERIOR DUE TO STRONG/GUSTY SOUTH WINDS PROVIDING DOWNSLOPING
WARMING. TEMPS NEAR LK MICHIGAN WILL REACH UPPER 70S. WILL BE BUMPY
AGAIN FOR WINDS/WAVES ON NORTHERN LK MICHIGAN ESPECIALLY ON SATURDAY
AFTN DUE TO THE INCREASING SOUTH WINDS. PROBABLY WILL NEED ANOTHER
SMALL CRAFT ADVISORY FOR THE MARINE INTERESTS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 407 AM EDT FRI AUG 21 2015
ALTHOUGH THE WEEKEND WL START ON A DRY AND WARMER NOTE...ANOTHER
POTENT SHRTWV DRIFTING E THRU THE NRN PLAINS TOWARD THE UPR LKS WL
BRING AN UNSETTLED PERIOD OF WX TO THE CWA LATE SAT NGT INTO EARLY
NEXT WEEK. TIMING/IMPACTS OF THIS DISTURBANCE ARE THE PRIMARY FOCUS
FOR THIS SHIFT. RIGHT NOW...THE ACCOMPANYING DYNAMIC FORCING LOOKS
SUFFICIENT TO JUSTIFY A PERIOD OF SOME HI LIKELY POPS AHEAD OF
ATTENDANT COLD FROPA FOR LATE SAT NGT THRU SUN DESPITE CONCERNS ON
MSTR INFLOW THAT WL LIMIT TS CHCS.
SAT...UPR MI WL REMAIN DOMINATED BY LARGE SCALE SUBSIDENCE/DRY
AIRMASS ASSOCIATED WITH SLOWLY EXITING UPR RDG TO THE E OF POTENT
SHRTWV MOVING INTO THE NRN PLAINS. GUSTY S FLOW BTWN SFC HI PRES
DRIFTING INTO THE MID ATLANTIC STATES AND LO PRES NEAR THE CNDN
BORDER/ATTENDANT COLD FNT MOVING INTO MN LATER IN THE DAY IS FCST TO
LIFT H85 TEMPS TO 16-18C...SUPPORTING HI TEMPS WELL INTO THE 80S
AWAY FM THE COOLING INFLUENCE OF LK MI WITH A GOOD DEAL OF SUNSHINE.
SAT NGT...ARRIVAL OF WARM CONVEYOR BELT MSTR RIBBON/SFC COLD FNT
OVER THE W HALF LATE SAT NGT AHEAD OF SHRTWV MOVING INTO MN WL BRING
A RETURN OF SHOWERS/SOME TS TO THAT AREA. DESPITE THE STRENGTH OF
THE INCOMING SHRTWV/SLY FLOW AHEAD OF THE FNT...OVERALL MSTR INFLOW
INTO UPR MI IS FCST TO BE SOMEWHAT LIMITED AND FOCUSED TO THE S IN
WI SO THAT ONLY A NARROW BAND OF PWAT ARND 1.50 INCHES IS SHOWN TO
MOVE INTO THE W OVERNGT. ARRIVAL OF THE FNT DURING PERIOD OF
NOCTURNAL COOLING WL ALSO BE A LIMITING FACTOR...WITH FCST MUCAPE NO
HIER THAN ABOUT 500-600 J/KG. BUT WITH 12HR H5 HGT FALLS UP TO 100M
AHEAD OF THE APRCHG SHRTWV THAT IS FCST TO BECOME CUTOFF AT H5...DID
RETAIN LIKELY POPS UNDER THE WARM CONVEYOR BELT. THE E HALF SHOULD
REMAIN DRY CLOSER TO DEPARTING SFC HI PRES TO THE E.
SUN...STRONG SHRTWV IS FCST TO DRIFT ONLY SLOWLY E THRU NRN MN...
PUSHING COLD FNT/WARM CONVEYOR BELT MSTR RIBBON TO NEAR NEWBERRY
LATE IN THE DAY. BAND OF SHOWERS WITH EMBEDDED TS IN PRESENCE OF
SOME DAYTIME HEATING WL DRIFT ACRS UPR MI ALONG THIS FNT UNDER AREA
OF SUPPORTING DEEP LYR QVECTOR CNVGC THAT MAY BE ENHANCED BY ANOTHER
DISTURBANCE ROTATING ARND THE SLOW MOVING CUTOFF H5 LO. ARRIVAL OF
SOME DEEP LYR QVECTOR DVGC/DRY SLOTTING WL DIMINISH THE SHOWER CHCS
W-E BEHIND THE FROPA...BUT AREA OF WRAP ARND LO-MID LVL MSTR IN
CONCERT WITH DAYTIME HEATING/UPSLOPE LLVL CYC W FLOW ARND LO PRES IN
ONTARIO MAY RESULT IN SOME MORE SHOWERS OVER THE W HALF IN THE AFTN.
H85 TEMPS ARE FCST TO FALL TO 6-8C OVER THE W HALF IN THE AFTN...SO
TEMPS MAY ACTUALLY FALL IN THAT AREA. THE 00Z NAM MODEL IS QUITE A
BIT SLOWER ON THE FROPA TIMING THAN THE OTHER MODELS AND WAS NOT
UTILIZED PER NCEP PREFERENCE.
SUN NGT THRU TUE...UPR MI IS FCST TO BE DOMINATED BY DEEP... STRONG
CYC NW FLOW OF COOL AIR ANRD STACKED CLOSED LO EXITING ONLY SLOWLY
TO THE ENE THRU ONTARIO. H85 TEMPS WL BE WITHIN A FEW DEGREES OF
5C...RESUTLING IN SOME COOL WX THAT WL BE MORE TYPICAL OF EARLY
FALL. GUSTY WINDS WITH H925 WINDS UP TO 30-35 KTS WL MAKE THE AIR
FEEL EVEN COOLER. COMBINATION OF THE SHARP CYC FLOW...POTENTIAL
EMBEDDED SHRTWVS ROTATING ARND THE CLOSED LO AND COOLNESS OF THE
AIRMASS OVER THE RELATIVELY WARM LK WATERS /WATER TEMPS OVER THE
OPEN WATERS OF WRN LK SUP ARE 15-17C/ WL RESULT IN NMRS SHOWERS...
ESPECIALLY OVER THE HIER TERRAIN OF THE NW HALF. GOING LIKELY POPS
IN THIS AREA SEEM ON TRACK. DAYTIME HEATING ON MON WL LIKELY RESULT
IN SCT SHOWERS EVEN AWAY FM THAT AREA. AS UPR HGTS GRDLY RISE ON TUE
AND THE LLVL CYC FLOW BEGINS TO WEAKEN ON TUE WITH THE CLOSER APRCH
OF TRAILING HI PRES...POPS/CLDS/GUSTY WINDS WL DIMINISH.
EXTENDED...TRAILING HI PRES WL BRING A DRY...SEASONABLE PERIOD ON
TUE NGT THRU WED NGT UNDER RISING HGTS TO THE E OF BLDG UPR RDG IN
THE PLAINS. DEPENDING ON HOW QUICKLY ANOTHER SHRTWV RIDES OVER THIS
RDG...SHOWER/TS CHCS MAY RETURN AS EARLY AS NEXT THU ALONG WITH SOME
WARMER WX.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 215 PM EDT FRI AUG 21 2015
VFR CONDITIONS WILL PERSIST THROUGH THE TAF PERIOD. SCATTERED MID
CLOUDS THIS AFTN AND A THICK SMOKE LAYER ALOFT TONIGHT INTO
SATURDAY. GUSTY SOUTH WINDS AT KIWD REST OF THE AFTN WILL GIVE WAY
TO LOW-LEVEL WIND SHEAR BY MIDNIGHT TONIGHT AS WINDS DIMINISH AT THE
SFC. WINDS WILL ALSO BECOME GUSTY FOR A TIME AT KSAW THIS AFTN AS
WELL. EXPECT STRONG AND GUSTY SOUTH WINDS AT ALL TAF SITES ON
SATURDAY ONCE LOW-LEVEL INVERSION BREAKS BY MID MORNING. WIND GUSTS
SATURDAY AFTN COULD TOP OUT NEAR 30 KTS AT KIWD AND KSAW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 316 PM EDT FRI AUG 21 2015
S WINDS INCREASE TO 25 KTS TONIGHT UNDER SHARPENING PRES GRADIENT
BETWEEN THE DEPARTING RIDGE AND A DEEP LOW PRESSURE SYSTEM MOVING
FROM THE NORTHERN PLAINS INTO ONTARIO. MAY SEE GUSTS TO 30 KTS OVER
EASTERN LK SUPERIOR ON SATURDAY AFTN. STEADY S WINDS WILL VEER
TOWARD THE W FOLLOWING A COLD FRONTAL PASSAGE ON LATE SAT NIGHT/SUN
AND INCREASE UP TO 30 KTS. DEPENDING ON THE INTENSITY OF A LOW
PRESSURE SYSTEM MOVING SLOWLY NE THRU ONTARIO...THERE COULD BE SOME
MARGINAL GALES TO 35 KTS AT TIMES ON SUN INTO MON WITH THE ARRIVAL
OF COOLER AIR/MORE DESTABILIZATION OVER THE RELATIVELY WARM LAKE
WATERS AS THE FLOW CONTINUES TO VEER TO THE NW UNDER TIGHT PRES
GRADIENT AHEAD OF APPROACHING HI PRES RIDGE FROM THE NORTHERN
PLAINS. AS THE HI MOVES CLOSER AND THE GRADIENT SLACKENS...EXPECT
WINDS TO DIMINISH LATER TUE INTO WED.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...KC
AVIATION...JLA
MARINE...JLA
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
1001 AM PDT FRI AUG 21 2015
.SYNOPSIS...HAZY CONDITIONS WILL CONTINUE OVER THE NEXT FEW DAYS DUE
TO SMOKE PASSING THROUGH THE AREA FROM CALIFORNIA WILDFIRES. A WEAK
PUSH OF MOISTURE WILL LEAD TO SLIGHT CHANCES FOR THUNDERSTORMS OVER
MAINLY THE HIGHER TERRAIN SOUTH OF INTERSTATE 15 FRIDAY AND
SATURDAY. DEEPER MOISTURE ARRIVES MONDAY AND COULD LINGER THROUGH
MID WEEK WHICH WILL RESULT IN INCREASING COVERAGE OF SHOWERS AND
STORMS. &&
.UPDATE...EXTENSIVE AREA OF SMOKE/HAZE VISIBLE OFF SATELLITE
COVERING MUCH OF INYO COUNTY AND SOUTHERN NEVADA. VISIBILITY SHOULD
IMPROVE THROUGHOUT THE DAY DUE TO A DEEPER MIXED LAYER.
BASED ON THE HRRR AND 12Z NAM/GFS REMOVED MENTION OF THUNDERSTORMS
FROM THE HIGHER TERRAIN OF SOUTHERN NEVADA AND MUCH OF MOHAVE COUNTY
TODAY. LEFT SLIGHT CHANCE MENTION FOR THE FAR NORTHEAST CORNER OF
MOHAVE COUNTY.
&&
.PREV DISCUSSION...150 AM PDT FRI AUG 21 2015
.SHORT TERM...THROUGH MONDAY NIGHT.
CLEAR SKIES DOMINATE THE FORECAST AREA EARLY THIS MORNING BUT THICK
SMOKE CONTINUES TO BE PROBLEMATIC ACROSS THE OWENS VALLEY. I
ANTICIPATE THE SMOKE WILL CONTINUE TO BE PREVAIL ACROSS THE OWENS
VALLEY AGAIN TODAY...ESPECIALLY FROM BISHOP SOUTHWARD TO OLANCHA.
ELSEWHERE...HAZE REMAINS POSSIBLE AS SMOKE FROM CALIFORNIA WILDFIRES
DRIFTS WEST...THROUGH AFTERNOON BREEZY CONDITIONS MAY HELP MIX OUT
THE HAZE AS IT DID THURSDAY...IMPROVING THE AIR QUALITY SOMEWHAT.
THE BIGGEST CONCERN IN THE SHORT TERM PERIOD BESIDES THE SMOKE
REVOLVES AROUND THUNDERSTORM CHANCES. MOISTURE HAS BEEN SEEPING
INTO THE AREA UNDER A SOUTHERLY FLOW IN THE LOWER LEVELS OF THE
ATMOSPHERE. DEWPOINTS EARLY THIS MORNING HAVE REACHED NEAR 60
DEGREES AT BULLHEAD CITY AND NEEDLES...AND MID 60S IN LAKE HAVASU.
FURTHER SOUTH...THE DEWPOINT IN YUMA HAS SHOT UP TO 75F AND VAD WIND
PROFILER DATA INDICATES A SOUTHERLY FLOW OF 15-20KTS IN THE LOWER 4K
FEET OF THE ATMOSPHERE DRIVING THIS DEEPER MOISTURE NORTHWARD. WHILE
MUCH OF THIS MOISTURE WILL MIX OUT WITH DAYTIME HEATING...THERE
SHOULD STILL BE ENOUGH MOISTURE TO KICK OFF SOME ISOLATED CONVECTION
ALONG THE HIGHER TERRAIN OF MOHAVE...EXTREME EASTERN SAN
BERNARDINO...AND SOUTHERN CLARK COUNTIES THIS AFTERNOON AND EVENING.
TROUBLE WILL BE THE LACK OF ANY SUBSTANCIAL TRIGGERING MECHANISM TO
GET THINGS GOING. EARLY MORNING RUNS OF THE HRRR DO NOT PAINT A VERY
PROMISING PICTURE FOR STORMS TODAY AND MOST MODEL GUIDANCE DOESNT
DEVELOP ACTIVITY DESPITE THE INSTABILITY PRESENT. OPTED TO MAINTAIN
THE SLIGHT CHANCE...TERRAIN ORIENTED POPS BUT CONFIDENCE IN
DEVELOPMENT IS NOT REAL HIGH. SIMILAR OUTLOOK FOR SATURDAY WITH
MARGINAL MOISTURE AND INSABILITY PRESENT...BUT NO REAL TRIGGER.
ON SUNDAY...ANY DISCERNIBLE INSTABILITY GETS SHIFTED FURTHER EAST
INTO FAR EASTERN MOHAVE COUNTY...SO KEPT POPS LIMITED TO THOSE FAR
EASTERN ZONES AND CONDITIONS DRY ELSEWHERE. TEMPERATURES FRIDAY
THROUGH THE WEEKEND WILL AVERAGE 3 TO 6 DEGREES ABOVE NORMAL.
ON MONDAY...LEADING EDGE OF DEEPER MONSOON MOISTURE BEGINS TO LIFT
INTO NORTHWEST ARIZONA AND EASTERN CALIFORNIA. BETTER MOISTURE AT
THIS POINT LOOKS TO ARRIVE OVERNIGHT AND INTO TUESDAY BUT SOME
ACTIVITY MAY BREAK OUT IN MOHAVE...EASTERN SAN BERNARDINO...AND THE
HIGHER TERRAIN OF CLARK COUNTIES AND MAINTAINED POPS IN THESE AREAS.
.LONG TERM...TUESDAY THROUGH FRIDAY.
MODELS HAVE COME INTO BETTER LARGE SCALE AGREEMENT FOR MUCH OF THE
PERIOD...BUT IMPORTANT DETAIL DIFFERENCES REMAIN. FOR TUESDAY...THE
GFS LOOKS MUCH LIKE ITS PREVIOUS RUNS...BUT THE ECMWF DEPICTS THE
FOUR CORNERS HIGH CENTER JUST A BIT FARTHER WEST...WHICH DELAYS THE
MOISTURE RETURN AND SENDS HIGH TEMPERATURES ZOOMING BACK UP TO NEAR
EXCESSIVE HEAT CRITERIA. WHILE THIS IS A POSSIBILITY...BELIEVE IT
HAS A LOW PROBABILITY OF OCCURRENCE GIVEN MODEL TRENDS OVER THE PAST
SEVERAL DAYS...AND HAVE GIVEN IT LITTLE WEIGHT IN THE FORECAST. THE
GFS SOLUTION...WHICH SUGGESTS PRECIP CHANCES ROUGHLY NEAR AND EAST
OF LAS VEGAS...WAS PREFERRED. FOR WEDNESDAY AND THURSDAY...MODELS
HAVE COME INTO MUCH BETTER AGREEMENT WITH AMPLIFICATION OF BOTH THE
NORTHERN STREAM LOW NEAR THE BRITISH COLUMBIA COAST AND THE RIDGE
EXTENDING NORTH INTO SASKATCHEWAN FROM THE FOUR CORNERS HIGH. THIS
LEAVES OUR CWA IN MOIST SOUTHERLY FLOW ON WEDNESDAY...TRANSITIONING
INTO A SLIGHTLY DRIER SOUTHWEST FLOW ON THURSDAY AS TROUGHING IN THE
EAST PACIFIC STRETCHES ALL THE WAY DOWN BELOW 30N. THERE IS
DISAGREEMENT ON HOW TO EVOLVE THIS TROUGHING ON FRIDAY...BUT DECENT
CONSENSUS THAT OUR SENSIBLE WEATHER WILL CHANGE LITTLE...WITH
SOUTHWEST FLOW BRINGING MINIMAL PRECIP CHANCES BUT PERHAPS NOT
STRONG ENOUGH TO SCOUR OUT LOW LEVEL MOISTURE...ESPECIALLY OVER
MOHAVE COUNTY.
&&
.AVIATION...FOR MCCARRAN...LIGHT SOUTHERLY DRAINAGE WINDS EXPECTED
EARLY IN THE MORNING BEFORE BECOMING LIGHT AND VARIABLE SUNRISE
THROUGH AROUND 17Z. A PERIOD OF SOUTHEAST WINDS OF 9-12KTS IS
POSSIBLE BETWEEN 17Z AND 20Z BEFORE SOUTH-SOUTHWEST WINDS TAKE OVER
IN THE AFTERNOON WITH GUSTS TO 25KTS. HAZY CONDITIONS REMAIN
POSSIBLE.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...AREAS OF HAZE EXPECTED MAINLY NORTH OF INTERSTATE 40
AGAIN TODAY WITH SMOKE MOST CONCENTRATED NEAR THE SIERRA AND OWENS
VALLEY. SMOKE MAY LOCALLY REDUCE VISIBILITIES TO BELOW 4 MILES.
OTHERWISE...BREEZY SOUTH WINDS OF 12-18 KTS WITH GUSTS TO 25KTS
EXPECTED ACROSS THE AREA IN THE AFTERNOON. SLIGHT CHANCES FOR
ISOLATED THUNDERSTORMS EXIST IN THE HIGHER TERRAIN MAINLY SOUTH AND
EAST OF KLAS THIS AFTERNOON.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
UPDATE...PIERCE
SHORT TERM...OUTLER
LONG TERM...MORGAN
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
331 PM MDT FRI AUG 21 2015
.SYNOPSIS...
HIGH PRESSURE ALOFT WILL GRADUALLY BUILD OVER THE AREA THROUGH
SATURDAY WITH DAYTIME TEMPERATURES REMAINING ABOVE NORMALS. BEST
THUNDERSTORM COVERAGE WILL REMAIN FOCUSED OVER THE HIGHER TERRAIN
AND SOUTHWEST SATURDAY AFTERNOON AND EVENING. THEREAFTER...ANOTHER
SEASONABLY STRONG BACKDOOR FRONT WILL BOOST STORM COVERAGE ON
SUNDAY ESPECIALLY FOR THE WESTERN AND SOUTHERN HALVES OF THE
STATE. DAYTIME TEMPERATURES WILL DOWNWARD AGAIN...ESPECIALLY
ACROSS THE EASTERN PLAINS WHERE HIGH TEMPERATURES ARE FORECAST TO
BE BELOW NORMAL AND A GOOD 15 TO 25 DEGREES COOLER AS COMPARED TO
SATURDAY. LOOKING AHEAD...AFTER A RELATIVELY ACTIVE DAY ON MONDAY
A GRADUAL WARMING AND DRYING TREND WILL DOMINATE MUCH OF NEXT WEEK
WITH STORM COVERAGE WANING EACH DAY THROUGH WEEK/S END.
&&
.DISCUSSION...
SUBTLE WAVE ALOFT/ASSOCIATED JET MAX TO TRANSLATE EAST OF THE
AREA BY EARLY EVENING. LOOKS TO BE VISUAL EVIDENCE OF SUBSIDENCE
EFFECTS IN THE IMMEDIATE FOUR CORNERS REGION. WILL NEED TO
CAREFULLY MONITOR THE FAR NE...EC/SE PLAINS NEXT SEVERAL HOURS.
A FAIRLY ATYPICAL SURFACE DRYLINE IN THE PROCESS OF SHARPENING
EAST OF DES MOINES TO SANTA ROSA TO FORT SUMNER LINE /SFC DEW
POINTS IN THE MID 20S TO MID 30S WEST OF THE DRYLINE WHILE MID 50S
TO NEAR 60 COMMON TO THE EAST/ WITH A MORE DIFFUSE W-E GRADIENT
OVER THE SOUTHEAST PLAINS. THIS BOUNDARY WILL LIKELY FOCUS A FEW
STRONG IF NOT BRIEFLY SEVERE STORMS LATER THIS AFTERNOON INTO
EARLY EVENING.
OTHERWISE...BETTER MOISTURE PROFILES CONTINUE OVER SC/SW ZONES
WHERE WE/LL CONTINUE TO FOCUS THE HIGHEST POPS. STORM MOTIONS
GENERALLY TOWARD THE SE AT 15-20 KTS...AND COULD SEE A FEW PULSE
STRONG STORMS WITH LOCALIZED GUSTY WINDS AND OF COURSE CG
LIGHTNING THE MAIN THREATS.
CONCEPTUAL MODEL WOULD ARGUE FOR A PRETTY QUIET PERIOD AFTER
MIDNIGHT AS 500MB HEIGHTS SLOWLY BUILD FROM SW TO NE. BUT THE
GFS/NAM AND NOT SURPRISINGLY HRRR REDEVELOP VERY ISOLATED QPF
OVER THE WEST ESPECIALLY NORTHWEST. THIS MAY BE IN RESPONSE TO YET
ANOTHER SPEED MAX WITHIN THE BASE OF YET ANOTHER VIGOROUS
SHORTWAVE TROUGH THAT WILL CROSS THE CENTRAL/NORTHERN ROCKIES LATE
TONIGHT. BEST GUESS IS WE COULD SEE SOME MID-LEVEL CLOUDINESS AND
VIRGA SHOWERS/SPRINKLES DURING THE OVERNIGHT BUT HIGHLY DOUBT WE
WOULD SEE A REPEAT OF EARLY MORNING T-STORMS.
GOING INTO SATURDAY NIGHT AND SUNDAY...FOCUS WILL BE ON THE
INCOMING BACKDOOR COLD FRONT THAT WILL FOLLOW IN WAKE OF THE ABOVE
MENTIONED SHORTWAVE. TIMING OF THE FRONT SIMILAR TO PREVIOUS
THINKING...INTO THE NORTHEAST SATURDAY EVENING PRESSING SOUTH AND
WEST OVERNIGHT SATURDAY NIGHT INTO MIDDAY SUNDAY. LOOKS PRETTY
COOL/STABLE ONCE AGAIN FOR THE NORTHEAST PLAINS...WITH THE FOCUS
FOR CONVECTIVE PRECIP SHIFTING WEST AND SOUTH. THE MODELS HONESTLY
LOOK A LITTLE UNDERCOOKED ON QPF FOR SUNDAY PM ESPECIALLY FOR
AREAS BETWEEN THE DIVIDE AND EAST SLOPES OF THE CENTRAL MOUNTAIN
CHAIN BUT THE CURRENT AIR MASS HAS NOT FULLY RECOVERED FROM THE
LAST DRYING EVENT AND NOT A TREMENDOUSLY MOIST AIR MASS BEING
USHERED IN WITH THIS FRONT. WILL SHOW AN UPWARD TREND IN POP
COVERAGE FOR SUNDAY...BUT GENERALLY NOT AS DRY AT THE NAM WOULD
SUGGEST.
WARMER ON MONDAY AND WITH ANY ADDITIONAL MOISTURE INPUT
ASSOCIATED WITH THE BACKDOOR PUSH WE EXPECT A DECENT INCREASE IN
T-STORM ACTIVITY. 500MB HIGH CENTER GENERALLY EXPECTED OVER THE
FOUR CORNERS OR PERHAPS A BIT EAST. STEERING WINDS WILL BE WEAK
BUT GENERALLY FROM N TO S...SO NOT ALL BAD NEWS FOR THE RIO GRANDE
VALLEY...NE AND CENTRAL HIGH PLAINS. RIDGE ALOFT FORECAST TO
STRENGTHEN TUE INTO MID-WEEK BEFORE SHIFTING WESTWARD LATE WEEK.
PROBABLY ANOTHER BACKDOOR COLD FRONT IN OUR FUTURE LATE THU OR
FRI. KJ
&&
.FIRE WEATHER...
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WITH WETTING RAIN
WILL CONTINUE DEVELOPING THROUGHOUT THE AFTERNOON INTO THE EVENING
ACROSS THE SOUTHWEST....SOUTH CENTRAL AND NORTHERN MOUNTAINS AND
PORTIONS OF THE FAR EASTERN PLAINS. GUSTY AND ERRATIC WINDS WILL
FOLLOW STORMS THAT PRODUCE OUTFLOW BOUNDARIES.
SATURDAY WILL SEE ISOLATED TO SCATTERED STORMS FAVORING HIGH TERRAIN
AREAS...WITH ABOVE NORMAL TEMPERATURES...HIGHER MIN RH VALUES IN THE
SOUTHWEST MOUNTAINS WITH 5 HAINES VALUES ACROSS THE NORTHEAST AND
EAST CENTRAL PLAINS. EXPECT BREEZY TO MODERATE WEST NORTHWEST WINDS
DURING THE DAY.
LATE SATURDAY INTO EARLY SUNDAY...A POTENT BACK DOOR FRONT WILL
INVADE THE NORTHEAST...COOLING TEMPERATURES 5 TO 15 DEGREES BELOW
NORMAL CENTRAL AND EAST WHILE WETTING RAIN CHANCES AND MIN RH VALUES
TREND UPWARD CENTRAL AND WEST. EAST CANYON WINDS COULD PEAK 35 TO 45
MPH EARLY SUNDAY ALONG THE CENTRAL MOUNTAINS AS THE BACK DOOR FRONT
PUSHES THROUGH THE GAPS TOWARD THE CONTINENTAL DIVIDE. BREEZY TO
MODERATE EAST WINDS WILL CONTINUE THROUGHOUT THE DAY...BECOMING
SOUTHEASTERLY BY THE LATE AFTERNOON...EARLY EVENING AS THE FRONT
WASHES OUT.
SO FAR...MODELS LOOK TO AGREE WITH A VERY ACTIVE MONDAY AS THE GFS
HAS THE UPPER LEVEL HIGH OVER THE STATE WITH STORMS FAVORING CENTRAL
AND WESTERN AREAS WHILE THE ECMWF HAS THE HIGH OVER THE GREAT BASIN
AND IS MORE BULLISH FOR ACTIVITY TO FAVOR CENTRAL AND EASTERN AREAS.
BY TUESDAY...GFS HAS THE HIGH LINGERING OVER THE STATE WHILE THE
ECMWF HAS THE HIGH HOVERING OVER THE FOUR CORNERS REGION.
OTHERWISE...TEMPERATURES LOOK TO REBOUND MONDAY AND TUESDAY IN THE
EAST BECOMING ABOVE NORMAL BY THE MIDWEEK.
GOOD TO EXCELLENT VENT RATES TODAY AND SATURDAY. BECOMING POOR
CENTRAL AND NORTH SUNDAY...IMPROVING IN THE EAST MONDAY THROUGH
WEDNESDAY. 32
&&
.AVIATION...
18Z TAF CYCLE
SCT CIGS CURRENTLY DEVELOPING ACROSS MUCH OF WESTERN AND CENTRAL
NEW MEXICO. LOOK FOR SHRA/TSRA ACTIVITY TO FAVOR THE
SOUTHWEST...NORTHERN AND SOUTH CENTRAL MTNS THIS AFTERNOON. HAD
LOW CONFIDENCE OF VCTS...SO KEPT VCSH FOR KABQ/KAEG...KSAF AND
KROW. EXPECT BREEZY TO MODERATE NORTHWEST WINDS BETWEEN 19 AND 00Z
ACROSS WESTERN AND CENTRAL AREAS. COULD SEE STORM CHANCES CONTINUE
AFTER SUNSET ACROSS THE SOUTHWEST MTNS AND THE FAR EASTERN PLAINS.
CML
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 60 91 59 90 / 10 5 10 10
DULCE........................... 48 85 49 84 / 10 10 10 20
CUBA............................ 53 82 53 80 / 10 20 10 20
GALLUP.......................... 55 86 54 86 / 30 20 20 30
EL MORRO........................ 52 82 51 80 / 30 20 20 50
GRANTS.......................... 55 84 53 80 / 30 20 20 20
QUEMADO......................... 56 82 54 80 / 30 30 30 40
GLENWOOD........................ 58 85 58 85 / 30 30 30 60
CHAMA........................... 47 79 47 77 / 10 40 20 30
LOS ALAMOS...................... 59 84 57 79 / 10 30 30 40
PECOS........................... 57 83 56 75 / 10 20 20 40
CERRO/QUESTA.................... 51 80 50 77 / 10 20 10 30
RED RIVER....................... 43 69 44 65 / 10 40 20 60
ANGEL FIRE...................... 46 72 46 67 / 10 20 30 40
TAOS............................ 46 84 50 78 / 10 20 10 20
MORA............................ 53 80 51 71 / 10 20 20 40
ESPANOLA........................ 57 89 56 84 / 10 10 10 10
SANTA FE........................ 60 85 58 79 / 10 20 10 20
SANTA FE AIRPORT................ 58 88 57 82 / 10 10 10 10
ALBUQUERQUE FOOTHILLS........... 64 90 63 84 / 20 10 10 10
ALBUQUERQUE HEIGHTS............. 67 92 64 86 / 20 10 10 10
ALBUQUERQUE VALLEY.............. 62 93 62 88 / 20 10 10 10
ALBUQUERQUE WEST MESA........... 65 94 63 88 / 10 10 10 10
LOS LUNAS....................... 64 93 62 87 / 20 10 10 10
RIO RANCHO...................... 65 93 63 87 / 10 10 10 10
SOCORRO......................... 66 94 63 89 / 20 10 20 10
SANDIA PARK/CEDAR CREST......... 58 86 57 79 / 20 20 10 20
TIJERAS......................... 57 88 56 80 / 20 10 10 10
MORIARTY/ESTANCIA............... 54 88 53 79 / 10 10 10 20
CLINES CORNERS.................. 58 85 54 75 / 10 10 10 20
GRAN QUIVIRA.................... 60 86 59 79 / 20 10 10 30
CARRIZOZO....................... 63 90 62 81 / 20 10 20 20
RUIDOSO......................... 60 82 56 74 / 20 30 30 30
CAPULIN......................... 57 84 53 73 / 10 20 30 10
RATON........................... 54 89 52 79 / 10 20 20 20
SPRINGER........................ 54 90 54 78 / 10 20 20 20
LAS VEGAS....................... 55 87 52 74 / 10 20 10 20
CLAYTON......................... 62 93 57 76 / 10 10 20 10
ROY............................. 59 90 56 73 / 10 20 20 10
CONCHAS......................... 64 96 61 78 / 10 10 20 10
SANTA ROSA...................... 62 95 61 79 / 10 10 20 10
TUCUMCARI....................... 65 98 63 79 / 10 10 20 10
CLOVIS.......................... 64 96 62 80 / 20 10 20 20
PORTALES........................ 65 96 64 81 / 20 10 20 20
FORT SUMNER..................... 66 97 64 79 / 10 10 20 10
ROSWELL......................... 68 101 67 86 / 20 10 20 30
PICACHO......................... 64 93 63 80 / 20 20 20 20
ELK............................. 63 86 61 76 / 20 20 20 40
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
41
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
601 PM EDT FRI AUG 21 2015
.SYNOPSIS...
HIGH PRESSURE WILL BUILD SOUTHWARD FROM THE EASTERN GREAT LAKES
THIS WEEKEND BRINGING DRIER WEATHER. ANOTHER COLD FRONT WILL
APPROACH FROM THE WEST TUESDAY WITH SCATTERED SHOWERS AND STORMS
RETURNING TO THE FORECAST. FRONT STALLS IN THE AREA DURING THE
MIDDLE OF THE WEAK AND SLOWLY DISSIPATES. DRIER AIR MAY MOVE INTO
THE AREA FOR THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 530 PM FRIDAY...THIS UPDATE WAS CONCERNED WITH THE
INCREASED DEVELOPMENT OF CONVECTION ACROSS THE FA. MAINLY ITS A
RESULT OF THE INTERACTION BETWEEN THE SEA BREEZE DRIFTING
INLAND... AND THE COOL FRONT DROPPING/DRIFTING SE-WARD. HAVE A
WIDE RANGE OF POPS ACROSS THE FA...MUCH OF IT ASSOCIATED WITH THE
LATEST 88D TRENDS IN REGARD TO LATEST CONVECTIVE DEVELOPMENT AND
MOVEMENT. HAVE ALSO UPPED QPF DUE TO WHAT THE LATEST 88DS ARE
SPITTING OUT... AND ESPECIALLY WITH CURRENT AND PROGGED 2.00 THRU
2.25 INCH PRECIPITABLE WATER RANGES.
PREVIOUS........................................................
AS OF 3 PM FRIDAY... THE COLD FRONT REMAINS TOUGH TO PICK OUT BUT
BASED ON THE LATEST OBS INCLUDING WINDS AND DEWPOINT DEPRESSIONS
IT APPEARS THAT THE FRONT IS BISECTING THE CWA FROM NE TO SW. IT
APPEARS TO BE MERGING WITH THE SEA BREEZE FRONT OVER OUR NC
COUNTIES...WHICH FURTHER COMPLICATES LOCATING THE COLD FRONT.
CONVECTION HAS FINALLY COMMENCED WITH ISOLATED SHOWERS FORMING IN
THE VICINITY OF THE COLD FRONT/SEA BREEZE FRONT CONGLOMERATION.
EXPECT THAT THIS FRONTAL FEATURE WILL CONTINUE TO BE THE FOCUS FOR
SCATTERED CONVECTION FOR THE REMAINDER OF THE AFTERNOON AND INTO
THE EVENING HOURS...WITH ACTIVITY SHUTTING DOWN BY AROUND MIDNIGHT
AS THIS IS ALL PRIMARILY DIURNALLY DRIVEN.
A CONSENSUS OF GUIDANCE GIVES US A NORTH TO SOUTH TEMPERATURE
GRADIENT...WITH LOWER 70S UP NORTH AND MID 70S TO THE SOUTH...AND
ALSO MID 70S AT THE COAST.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...REMAINS OF WEAK FRONT OFF THE NC COAST AT THE
START OF THE PERIOD WILL EXTEND WEST ACROSS NORTHERN SC. ALTHOUGH
THE FRONT WILL BECOME QUITE DIFFUSE BY MIDDAY STILL THINK PRECIP
CHANCES WILL REMAIN ELEVATED ACROSS PORTIONS OF SC. HIGH PRESSURE
BUILDING IN FROM THE NORTH HELPS KEEP PRESSURE GRADIENT
WEAK...WITH WEAK SEA BREEZE DEVELOPMENT IN THE AFTERNOON MASKING
THE FRONT. MOISTURE POOLING ALONG THE FRONT COUPLED WITH DIURNAL
HEATING IS LIKELY TO LEAD TO DEVELOPMENT OF AFTERNOON SHOWERS AND
THUNDERSTORMS. HAVE MAINTAINED INHERITED CHC TO SLIGHT CHC POP
ACROSS ILM SC COUNTIES. PRECIP SHOULD BE WEAKER AND DIURNAL IN
NATURE SO ONCE SUN SETS DEBRIS CLOUD WILL LINGER BUT PRECIP
COVERAGE SHOULD RAPIDLY DECREASE. TEMPERATURES SAT AND SAT NIGHT
WILL BE NEAR CLIMO.
WEAK SURFACE RIDGING REMAINS OVER THE EAST COAST SUN WITH MID
LEVEL FLOW ALOFT BECOMING PROGRESSIVE. WEAK SHORTWAVE MOVES ACROSS
THE SOUTHEAST LATER IN THE DAY...ACCOMPANIED BY AN INCREASED IN
MID LEVEL MOISTURE. THE CORE OF THE SHORTWAVE PASSES SOUTH OF THE
FORECAST AREA BUT PVA AHEAD OF IT COULD GENERATE SOME LATE
AFTERNOON/EVENING CONVECTION ACROSS MAINLY THE SC COUNTIES. WILL
CARRY AFTERNOON EVENING SLIGHT CHC/CHC POP TO COVER THE PASSAGE OF
THE WAVE. DEPENDING ON THE SPEED OF THE WAVE CONVECTION COULD
LINGER INTO THE OVERNIGHT PERIOD...BUT WEAK SUBSIDENCE FOLLOWING
THE SHORTWAVE SHOULD END ANY CONVECTION BY DAY BREAK. TEMPERATURES
WILL REMAIN NEAR CLIMO SUN AND SUN NIGHT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 330 PM FRIDAY...SHORTWAVE WILL PUSH A COLD FRONT INTO THE
CAROLINAS BUT IT LOOKS LIKE THIS FRONT WILL BECOME WASHED OUT AND
LINGER JUST SOUTH OR OVER THE COASTAL CAROLINAS. A MID TO UPPER
TROUGH DIGGING DOWN FROM THE GREAT LAKES WILL ALIGN WITH THIS
SHORTWAVE LEAVING A DEEP TROUGH DOWN THE EAST COAST THROUGH MUCH
OF THE UPCOMING WEEK. THE WINDS VEER AROUND TO THE NORTH
ALOFT...BUT OVERALL REMAIN QUITE LIGHT AND VARIABLE WITHOUT MUCH
OF A DRIVING FORCE TO THE FRONT. EXPECT GREATEST CHC OF PCP
FARTHER INLAND ON MON AFTN AND SHOULD PUSH TOWARD THE COAST ON
TUES. THIS BOUNDARY ALONG WITH LOCALIZED CONVERGENCE ALONG SEA
BREEZE AND PIEDMONT TROUGH FURTHER INLAND WILL CONTRIBUTE TO
DIURNAL CU DEVELOPMENT AND CONVECTIVE ACTIVITY. THE MODELS ARE NOT
GENERATING TOO MUCH IN THE WAY OF QPF AND DO NOT EXPECT CONVECTION
TO BE TOO WIDESPREAD...BUT LOCALIZED HEAVIER AMT ARE LIKELY IN
STRONGER STORMS. ANOTHER SHORTWAVE WILL ROTATE AROUND MAIN TROUGH
AND SHOULD ADVECT DRIER AIR IN FROM THE NORTHWEST BY THURS INTO
FRI. PCP WATER VALUES UP CLOSER TO 1.75 INCHES WILL FALL DOWN
BELOW 1.5 INCHES THURS INTO FRI PRIMARILY OVER INLAND TO NORTHWEST
PORTIONS OF AREA. ESSENTIALLY EXPECT AN EXTENDED PERIOD OF
UNSETTLED WEATHER WITH CU DEVELOPMENT EACH AFTN AS WELL AS DEBRIS
CLOUDS AND GOOD CHANCES FOR SHOWERS AND THUNDERSTORMS.
THE INCREASED CHC OF CLOUDS AND CONVECTION ALONG WITH LOWERING OF
H5 HEIGHT AND LOW LEVEL THICKNESSES WILL KEEP TEMPS NEAR OR BELOW
NORMAL AFTER MONDAY.
&&
.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
AS OF 18Z...FRONT SEEMS TO BE STALLED OVER THE SOUTHERN PORTION
OF THE CWA. WINDS ARE NEARLY CALM...WITH A WEAK NORTHERLY
COMPONENT THAT WILL BE REPLACED WITH A SOUTHEAST SEA BREEZE THIS
AFTERNOON. THE HRRR DOES HAVE SOME WEAK CONVECTION WITH THE
RESULTANT...ENOUGH FOR A VCSH MENTION. LIGHT WINDS TONIGHT WITH
SOME STRATUS LIKELY RETURNING AFTER 06Z. SATURDAY...BECOMING VFR
WITH NORTHEAST FLOW. ISOLATED CONVECTION IS EXPECTED...MAINLY
ALONG THE RESULTANT AND OVER THE WESTERN PORTION OF THE CWA WHERE
THE DEEPER MOISTURE WILL RESIDE.
EXTENDED OUTLOOK...PREDOMINATELY VFR WITH SCATTERED SHOWERS AND
THUNDERSTORMS THROUGH THE EXTENDED.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 530 PM FRIDAY...THIS UPDATE CONCERNED WITH INCREASING
CONVECTIVE POPS...MAINLY CLOSER TO SHORE DUE TO THE PCPN MOVING
OFF THE MAINLAND. OTHERWISE...MAINTAINED THE BASICALLY VARIABLE
WIND DIRECTION AT 10 KT OR LESS AHEAD OF THE COOL FRONT THIS
EVENING. WINDS SHOULD ALL BECOME NE-ENE AFTER MIDNIGHT...WITH
SPEEDS AROUND 10 KT. THE SFC PG DOES TIGHTEN AFTER THE CFP...BUT
ITS DELAYED UNTIL DAYLIGHT SAT.
PREVIOUS.....................................................
AS OF 3 PM FRIDAY...WINDS WILL STAY LIGHT THROUGH THE NEAR
TERM...BECOMING VARIABLE AT TIMES AS A COLD FRONT STALLS IN THE
VICINITY. THESE LIGHT WINDS WILL KEEP SEAS MANAGEABLE...AT RIGHT
AROUND 2 FT THROUGH THE PERIOD.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...HIGH PRESSURE TO THE NORTH WILL BUILD SOUTH
WITH WEAK FRONT DISSIPATING OVER OR JUST EAST OF THE WATERS
SATURDAY. HIGH PRESSURE REMAINS IN CONTROL THROUGH THE PERIOD WITH
WEAK GRADIENT KEEPING WINDS LIGHT. INITIALLY WINDS WILL BE FROM
THE NORTH-NORTHEAST BUT VEER TO SOUTHERLY DURING SAT. WINDS REMAIN
SOUTHERLY THROUGH THE END OF THE PERIOD WITH SLIGHT INCREASES EACH
AFTERNOON DUE TO SEA BREEZE DEVELOPMENT. SEAS WILL RUN 2 TO 3
FT.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 330 PM FRIDAY...WINDS WILL HAVE A GREATER SOUTHERLY
COMPONENT ON MONDAY AS COLD FRONT APPROACHES THE AREA. OVERALL
EXPECT A LIGHTER PREVAILING WIND FLOW DOMINATED BY LAND/SEA BREEZE
AS A COLD FRONT DROPS SOUTH AND WEAKENS. DIURNAL FLUCTUATIONS ARE
EXPECTED WITH A SPIKE IN WINDS AND CHOPPIER SEAS EACH AFTN. AS
FRONT LINGERS CLOUDS AND PCP MAY PLAY A ROLE EACH DAY IN STRENGTH
OF SEA BREEZE. SEAS WILL BE PRIMARILY 2 TO 3 FT WITH A LONGER
PERIOD UP TO 12 SEC SE SWELL MIXING IN MON NIGHT THROUGH MID WEEK
FROM VERY DISTANT TROPICAL SYSTEM OUT IN THE TROPICAL ATLANTIC.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...III
NEAR TERM...DCH/REK
SHORT TERM...III
LONG TERM...RGZ
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
357 PM EDT FRI AUG 21 2015
.SYNOPSIS...
HIGH PRESSURE WILL BUILD SOUTHWARD FROM THE EASTERN GREAT LAKES
THIS WEEKEND BRINGING DRIER WEATHER. ANOTHER COLD FRONT WILL
APPROACH FROM THE WEST TUESDAY WITH SCATTERED SHOWERS AND STORMS
RETURNING TO THE FORECAST. FRONT STALLS IN THE AREA DURING THE
MIDDLE OF THE WEAK AND SLOWLY DISSIPATES. DRIER AIR MAY MOVE INTO
THE AREA FOR THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 3 PM FRIDAY... THE COLD FRONT REMAINS TOUGH TO PICK OUT BUT
BASED ON THE LATEST OBS INCLUDING WINDS AND DEWPOINT DEPRESSIONS
IT APPEARS THAT THE FRONT IS BISECTING THE CWA FROM NE TO SW. IT
APPEARS TO BE MERGING WITH THE SEA BREEZE FRONT OVER OUR NC
COUNTIES...WHICH FURTHER COMPLICATES LOCATING THE COLD FRONT.
CONVECTION HAS FINALLY COMMENCED WITH ISOLATED SHOWERS FORMING IN
THE VICINITY OF THE COLD FRONT/SEA BREEZE FRONT CONGLOMERATION.
EXPECT THAT THIS FRONTAL FEATURE WILL CONTINUE TO BE THE FOCUS FOR
SCATTERED CONVECTION FOR THE REMAINDER OF THE AFTERNOON AND INTO
THE EVENING HOURS...WITH ACTIVITY SHUTTING DOWN BY AROUND MIDNIGHT
AS THIS IS ALL PRIMARILY DIURNALLY DRIVEN.
A CONSENSUS OF GUIDANCE GIVES US A NORTH TO SOUTH TEMPERATURE
GRADIENT...WITH LOWER 70S UP NORTH AND MID 70S TO THE SOUTH...AND
ALSO MID 70S AT THE COAST.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...REMAINS OF WEAK FRONT OFF THE NC COAST AT THE
START OF THE PERIOD WILL EXTEND WEST ACROSS NORTHERN SC. ALTHOUGH
THE FRONT WILL BECOME QUITE DIFFUSE BY MIDDAY STILL THINK PRECIP
CHANCES WILL REMAIN ELEVATED ACROSS PORTIONS OF SC. HIGH PRESSURE
BUILDING IN FROM THE NORTH HELPS KEEP PRESSURE GRADIENT
WEAK...WITH WEAK SEA BREEZE DEVELOPMENT IN THE AFTERNOON MASKING
THE FRONT. MOISTURE POOLING ALONG THE FRONT COUPLED WITH DIURNAL
HEATING IS LIKELY TO LEAD TO DEVELOPMENT OF AFTERNOON SHOWERS AND
THUNDERSTORMS. HAVE MAINTAINED INHERITED CHC TO SLIGHT CHC POP
ACROSS ILM SC COUNTIES. PRECIP SHOULD BE WEAKER AND DIURNAL IN
NATURE SO ONCE SUN SETS DEBRIS CLOUD WILL LINGER BUT PRECIP
COVERAGE SHOULD RAPIDLY DECREASE. TEMPERATURES SAT AND SAT NIGHT
WILL BE NEAR CLIMO.
WEAK SURFACE RIDGING REMAINS OVER THE EAST COAST SUN WITH MID
LEVEL FLOW ALOFT BECOMING PROGRESSIVE. WEAK SHORTWAVE MOVES ACROSS
THE SOUTHEAST LATER IN THE DAY...ACCOMPANIED BY AN INCREASED IN
MID LEVEL MOISTURE. THE CORE OF THE SHORTWAVE PASSES SOUTH OF THE
FORECAST AREA BUT PVA AHEAD OF IT COULD GENERATE SOME LATE
AFTERNOON/EVENING CONVECTION ACROSS MAINLY THE SC COUNTIES. WILL
CARRY AFTERNOON EVENING SLIGHT CHC/CHC POP TO COVER THE PASSAGE OF
THE WAVE. DEPENDING ON THE SPEED OF THE WAVE CONVECTION COULD
LINGER INTO THE OVERNIGHT PERIOD...BUT WEAK SUBSIDENCE FOLLOWING
THE SHORTWAVE SHOULD END ANY CONVECTION BY DAY BREAK. TEMPERATURES
WILL REMAIN NEAR CLIMO SUN AND SUN NIGHT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 330 PM FRIDAY...SHORTWAVE WILL PUSH A COLD FRONT INTO THE
CAROLINAS BUT IT LOOKS LIKE THIS FRONT WILL BECOME WASHED OUT AND
LINGER JUST SOUTH OR OVER THE COASTAL CAROLINAS. A MID TO UPPER
TROUGH DIGGING DOWN FROM THE GREAT LAKES WILL ALIGN WITH THIS
SHORTWAVE LEAVING A DEEP TROUGH DOWN THE EAST COAST THROUGH MUCH OF
THE UPCOMING WEEK. THE WINDS VEER AROUND TO THE NORTH ALOFT...BUT
OVERALL REMAIN QUITE LIGHT AND VARIABLE WITHOUT MUCH OF A DRIVING
FORCE TO THE FRONT. EXPECT GREATEST CHC OF PCP FARTHER INLAND ON MON
AFTN AND SHOULD PUSH TOWARD THE COAST ON TUES. THIS BOUNDARY ALONG
WITH LOCALIZED CONVERGENCE ALONG SEA BREEZE AND PIEDMONT TROUGH
FURTHER INLAND WILL CONTRIBUTE TO DIURNAL CU DEVELOPMENT AND
CONVECTIVE ACTIVITY. THE MODELS ARE NOT GENERATING TOO MUCH IN THE
WAY OF QPF AND DO NOT EXPECT CONVECTION TO BE TOO WIDESPREAD...BUT
LOCALIZED HEAVIER AMTS ARE LIKELY IN STRONGER STORMS. ANOTHER
SHORTWAVE WILL ROTATE AROUND MAIN TROUGH AND SHOULD ADVECT DRIER AIR
IN FROM THE NORTHWEST BY THURS INTO FRI. PCP WATER VALUES UP CLOSER
TO 1.75 INCHES WILL FALL DOWN BELOW 1.5 INCHES THURS INTO FRI
PRIMARILY OVER INLAND TO NORTHWEST PORTIONS OF AREA. ESSENTIALLY
EXPECT AN EXTENDED PERIOD OF UNSETTLED WEATHER WITH CU DEVELOPMENT
EACH AFTN AS WELL AS DEBRIS CLOUDS AND GOOD CHANCES FOR SHOWERS AND
THUNDERSTORMS.
THE INCREASED CHC OF CLOUDS AND CONVECTION ALONG WITH LOWERING OF H5
HEIGHT AND LOW LEVEL THICKNESSES WILL KEEP TEMPS NEAR OR BELOW
NORMAL AFTER MONDAY.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
AS OF 18Z...FRONT SEEMS TO BE STALLED OVER THE SOUTHERN PORTION
OF THE CWA. WINDS ARE NEARLY CALM...WITH A WEAK NORTHERLY
COMPONENT THAT WILL BE REPLACED WITH A SOUTHEAST SEA BREEZE THIS
AFTERNOON. THE HRRR DOES HAVE SOME WEAK CONVECTION WITH THE
RESULTANT...ENOUGH FOR A VCSH MENTION. LIGHT WINDS TONIGHT WITH
SOME STRATUS LIKELY RETURNING AFTER 06Z. SATURDAY...BECOMING VFR
WITH NORTHEAST FLOW. ISOLATED CONVECTION IS EXPECTED...MAINLY
ALONG THE RESULTANT AND OVER THE WESTERN PORTION OF THE CWA WHERE
THE DEEPER MOISTURE WILL RESIDE.
EXTENDED OUTLOOK...PREDOMINATELY VFR WITH SCATTERED SHOWERS AND
THUNDERSTORMS THROUGH THE EXTENDED.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM FRIDAY...WINDS WILL STAY LIGHT THROUGH THE NEAR
TERM...BECOMING VARIABLE AT TIMES AS A COLD FRONT STALLS IN THE
VICINITY. THESE LIGHT WINDS WILL KEEP SEAS MANAGEABLE...AT RIGHT
AROUND 2 FT THROUGH THE PERIOD.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...HIGH PRESSURE TO THE NORTH WILL BUILD SOUTH
WITH WEAK FRONT DISSIPATING OVER OR JUST EAST OF THE WATERS
SATURDAY. HIGH PRESSURE REMAINS IN CONTROL THROUGH THE PERIOD WITH
WEAK GRADIENT KEEPING WINDS LIGHT. INITIALLY WINDS WILL BE FROM
THE NORTH-NORTHEAST BUT VEER TO SOUTHERLY DURING SAT. WINDS REMAIN
SOUTHERLY THROUGH THE END OF THE PERIOD WITH SLIGHT INCREASES EACH
AFTERNOON DUE TO SEA BREEZE DEVELOPMENT. SEAS WILL RUN 2 TO 3
FT.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 330 PM FRIDAY...WINDS WILL HAVE A GREATER SOUTHERLY COMPONENT
ON MONDAY AS COLD FRONT APPROACHES THE AREA. OVERALL EXPECT A
LIGHTER PREVAILING WIND FLOW DOMINATED BY LAND/SEA BREEZE AS A COLD
FRONT DROPS SOUTH AND WEAKENS. DIURNAL FLUCTUATIONS ARE EXPECTED
WITH A SPIKE IN WINDS AND CHOPPIER SEAS EACH AFTN. AS FRONT LINGERS
CLOUDS AND PCP MAY PLAY A ROLE EACH DAY IN STRENGTH OF SEA BREEZE.
SEAS WILL BE PRIMARILY 2 TO 3 FT WITH A LONGER PERIOD UP TO 12 SEC
SE SWELL MIXING IN MON NIGHT THROUGH MID WEEK FROM VERY DISTANT
TROPICAL SYSTEM OUT IN THE TROPICAL ATLANTIC.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...REK
SHORT TERM...III
LONG TERM...RGZ
AVIATION...DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
130 PM EDT FRI AUG 21 2015
.SYNOPSIS...
A COLD FRONT WILL WAVER ACROSS THE AREA TODAY...BRINGING A
RENEWED CHANCE FOR SHOWERS AND THUNDERSTORMS. MOSTLY SUNNY AND
SEASONABLE WEATHER WILL FOLLOW FOR THE WEEKEND BEHIND THIS FRONT.
WARMER AND MORE HUMID AIR WILL RETURN NEXT WEEK AHEAD OF A COLD
FRONT WHICH WILL APPROACH ON TUESDAY...AND THEN STALL ACROSS THE
AREA THROUGH THURSDAY BRINGING COOLER AND UNSETTLED CONDITIONS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 130 PM FRIDAY...AS EXPECTED...STILL WAITING ON THE FIRST
SIGNIFICANT CONVECTION OF THE DAY TO FIRE OFF. AN EXTENSIVE CU
FIELD HAS DEVELOPED HOWEVER...AND GIVEN STRONG HEATING AND A MOIST
COLUMN WILL LIKELY SEE OUR FIRST SHOWERS OF THE DAY FORM SOON.
RETAINING CHANCE POPS FOR THIS AFTERNOON/EVENING. PREVIOUS
DISCUSSIONS FOLLOW:
HARD TO PICK OUT THE FRONT THIS MORNING. BASED ON WIND DIRECTIONS
IT APPEARS TO BE WAVERING ACROSS THE AREA AND MAY BE JUST OFFSHORE
AT THIS TIME. ANALYSIS OF MORNING SOUNDING DATA SHOWS A VERY MOIST
ATMOSPHERE WITH DEWPOINTS WELL IN THE 70S AND P/W VALUES
APPROACHING 2.25 INCHES. NAM IS STILL LIKING SCATTERED CONVECTION
THIS AFTERNOON...ESPECIALLY NEAR THE COAST...ALTHOUGH THE HRRR
CONTINUES IN A MORE MODEST VEIN...WITH ISOLATED SEA-BREEZE
CONVECTION FIRING UP THIS AFTERNOON. KEEPING PRESENT CHANCE POPS
IN PLACE AS WITH SUCH A MOIST COLUMN IT WILL NOT TAKE MUCH TO KICK
OFF CONVECTION. PREVIOUS DISCUSSION FOLLOWS:
DESPITE GREAT MODEL-TO-MODEL CONSISTENCY 24 HOURS AGO THE COLD
FRONT IS LAGGING THOSE PROGS BY NEARLY 100 MILES THIS MORNING. AT
6 AM THE FRONT APPEARS TO LIE ROUGHLY ALONG A LINE FROM
ELIZABETHTOWN AND WHITEVILLE TO MYRTLE BEACH AND GEORGETOWN. THIS
IS ANALYZED MORE BY PRESSURE THAN WIND SINCE WINDS ARE NEARLY CALM
ON EITHER SIDE OF THE BOUNDARY. THE FRONT SHOULD CROSS THE NORTH
CAROLINA BEACHES IN THE NEXT 1-2 HOURS...BUT WITH LITTLE WIND
BEHIND THE FRONT THERE WILL BE NO SIGNIFICANT AIRMASS CHANGE.
TEMPERATURES RISING INTO THE LOWER 90S INLAND THIS AFTERNOON
SHOULD TRIGGER A SEABREEZE WHICH WILL MOVE THE EFFECTIVE LOCATION
OF THE FRONT BACK INLAND DUE TO DEVELOPING ONSHORE WINDS ALONG THE
COAST.
WITH DEWPOINTS HOLDING IN THE LOWER 70S SURFACE-BASED INSTABILITY
SHOULD GROW TO 1000-2000 J/KG THIS AFTERNOON. SYNOPTIC AND FINE-
SCALE MODELS ALL SHOW THE POTENTIAL FOR AT LEAST SCATTERED SHOWERS
AND STORMS THIS AFTERNOON...MOST NUMEROUS NEAR THE COAST WHERE
SEABREEZE-ENHANCED CONVERGENCE WILL ASSIST THE GROWING CUMULUS
CLOUDS. FORECAST POPS RANGE FROM 20 PERCENT INLAND TO 30-40 PERCENT
ON THE COAST. LIGHT TROPOSPHERIC WINDS MEAN ANY CONVECTION WILL
LIKELY BE DISORGANIZED PULSE-TYPE WITH NO SIGNIFICANT POTENTIAL FOR
SEVERE WEATHER.
DAYTIME CLOUDS WILL BE SLOW TO CLEAR TONIGHT ESPECIALLY ACROSS SOUTH
CAROLINA WHERE A MID-LEVEL DISTURBANCE IS PROGGED TO MOVE IN FROM
THE WEST DURING THE EVENING HOURS. THIS SHOULD SPREAD MID-LEVEL
CLOUDS EASTWARD TOWARD THE COAST. A SMALL CHANCE OF SHOWERS AND
STORMS WILL BE MAINTAINED OVERNIGHT ACROSS THE PEE DEE REGION DUE TO
THE MOISTURE ADVECTING EASTWARD...AND OVERNIGHT LOWS HAVE BEEN
ADJUSTED UPWARD DUE TO LESS RADIATIONAL COOLING EXPECTED.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...A BEAUTIFUL WKND IN STORE AS A COLD FRONT WILL
BE WELL SOUTH OF THE AREA...LEAVING DRYING AND MOSTLY SUNNY
CONDITIONS FOR SATURDAY AND SUNDAY. SATURDAY STILL HAS A CHANCE FOR
SOME ISOLATED SHOWERS/TSTMS ACROSS THE SOUTHERN TIER OF ZONES WHERE
PWATS WILL BE HIGHER AND THE FRONT WILL STILL BE IN THE
VICINITY...POTENTIALLY INTERACTING WITH A WEAK SHORTWAVE MOVING IN
FROM THE MIDLANDS OF SC...BUT NOT EXPECTING WIDESPREAD OR HEAVY
CONVECTION...AND INTENSITY/COVERAGE WILL DECREASE THROUGH THE
AFTN/EVE ON THE DRY ADVECTION. SUNDAY STILL SHAPING UP TO BE A
GORGEOUS DAY...ALTHOUGH FLOW IS PROGGED TO RETURN TO THE SW
EARLIER THAN PREVIOUSLY. THIS WILL CAUSE TEMPS TO BE
WARMER...ALONG WITH SLIGHTLY HIGHER HUMIDITY THAN PREVIOUSLY
FORECAST...BUT STILL EXPECT BRIGHT SUNSHINE AND A GREAT LATE-
AUGUST DAY.
TEMPS SATURDAY WILL BE AROUND SEASONABLE LEVELS AS COOL ADVECTION IS
LACKING BEHIND THE FRONT. EXPECT HIGHS AROUND 87 FAR NW TO ABOUT 90
ALONG THE SOUTHERN TIER. MAX TEMPS ON SUNDAY WILL BE ABOUT 1-3
DEGREES WARMER EVERYWHERE. SUB-CLIMO MINS SATURDAY NIGHT THANKS TO
THE DRY COLUMN...AND LOWS WILL DROP INTO THE REFRESHING
CATEGORY...DROPPING INTO THE MID 60S WELL NW TO AROUND 70 AT THE
COAST. MORE TYPICAL MINS SUNDAY NIGHT WITH LOWS A DEGREE OR TWO
EITHER SIDE OF 70.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 300 AM FRIDAY...MID-LEVEL FLOW TO BECOME ANOMALOUSLY AMPLIFIED
FOR AUGUST MUCH OF THE UPCOMING WEEK AS A LARGE TROUGH DEVELOPS
ACROSS THE EAST WITH A BIG RIDGE BLOSSOMING OVER THE MTN WEST.
ALTHOUGH MONDAY WILL FEATURE WARM TEMPS...POSSIBLY ABOVE
NORMAL...WITH TYPICAL SUMMERTIME CONVECTION CHANCES...THIS IS
LOOKING TO BE THE ONE ABOVE-NORMAL DAY OF THE PERIOD. THEREAFTER A
COLD FRONT DROPS INTO THE CAROLINAS AND STALLS THROUGH MID-WEEK
BEFORE FINALLY GETTING PUSHED SOUTH LATE WED INTO THU. THIS WILL
CREATE AN EXTENDED PERIOD OF UNSETTLED WEATHER WITH GOOD CHANCES FOR
SHOWERS AND THUNDERSTORMS...ALONG WITH SUB-CLIMO TEMPS THANKS TO
LOWERED THICKNESSES WITHIN THE TROUGH COMBINING WITH CLOUDS AND
PRECIP. HARD TO SAY THE ENTIRE TUE-THU PERIOD WILL BE WET AND
CLOUDY...BUT AT LEAST A GOOD PORTION OF EACH DAY LOOKS TO BE
UNSETTLED WITH HIGHS SLIGHTLY BELOW CLIMO AND LOWS SLIGHTLY ABOVE AS
DIURNAL RANGES BECOME COMPRESSED
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 18Z...FRONT SEEMS TO BE STALLED OVER THE SOUTHERN PORTION
OF THE CWA. WINDS ARE NEARLY CALM...WITH A WEAK NORTHERLY
COMPONENT THAT WILL BE REPLACED WITH A SOUTHEAST SEA BREEZE THIS
AFTERNOON. THE HRRR DOES HAVE SOME WEAK CONVECTION WITH THE
RESULTANT...ENOUGH FOR A VCSH MENTION. LIGHT WINDS TONIGHT WITH
SOME STRATUS LIKELY RETURNING AFTER 06Z. SATURDAY...BECOMING VFR
WITH NORTHEAST FLOW. ISOLATED CONVECTION IS EXPECTED...MAINLY
ALONG THE RESULTANT AND OVER THE WESTERN PORTION OF THE CWA WHERE
THE DEEPER MOISTURE WILL RESIDE.
EXTENDED OUTLOOK...PREDOMINATELY VFR WITH SCATTERED SHOWERS AND
THUNDERSTORMS THROUGH THE EXTENDED.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM FRIDAY...LIGHT AND VARIABLE WINDS WITH 2 FT WAVES
CONTINUE OVER THE WATERS THIS AFTERNOON AS A COLD FRONT WAVERS IN
THE VICINITY. NO CHANGES TO THE FORECAST WITH THE LATEST UPDATE.
PREVIOUS DISCUSSION FOLLOWS:
SLOW-MOVING COLD FRONT SHOULD MOVE OFF THE BEACHES SHORTLY AFTER
SUNRISE THIS MORNING. WESTERLY WINDS IN ADVANCE OF THE FRONT WILL
VEER NORTHERLY LATER THIS MORNING BUT WITH NO INCREASE IN WIND
SPEED. BY THIS AFTERNOON THE TYPICAL SEABREEZE CIRCULATION SHOULD
OVERWHELM WHAT LITTLE WIND EXISTS BEHIND THE FRONT...WITH ONSHORE
WINDS 10 KNOTS OR LESS EXPECTED ALL ALONG THE COAST. ENOUGH
MOISTURE WILL REMAIN BEHIND THE FRONT THAT A FEW SHOWERS AND
STORMS SHOULD FIRE UP DURING THE AFTERNOON HOURS NEAR THE COAST
ALONG THE SEABREEZE BOUNDARY. STEERING WINDS ALOFT WILL BE LIGHT
AND FROM THE NORTHWEST...PERHAPS PUSHING ANY OF THIS ISOLATED
SHOWER/STORM ACTIVITY OUT ACROSS THE BEACHES AND INTO THE COASTAL
WATERS.
A NORTH-NORTHEAST WIND WILL GRADUALLY INCREASE LATE TONIGHT...
REACHING 10-15 KNOTS LATE. SEAS SHOULD AVERAGE ONLY 2 FEET TODAY AND
TONIGHT...PERHAPS BUILDING TO 3 FEET IN EXPOSED WATERS LATE.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...HIGH PRESSURE RIDGING DOWN THE COAST BEHIND A
COLD FRONT WILL CREATE N/NE WINDS SATURDAY AND THE FIRST HALF OF
SUNDAY. THE GRADIENT ASSOCIATED WITH THIS HIGH PRESSURE IS WEAK...SO
WIND SPEEDS WILL BE 10 KTS OR LESS FROM THIS DIRECTION...AFTER A
BRIEF SURGE UP TO 15 KTS EARLY SATURDAY. LATE SUNDAY...RETURN FLOW
WILL BEGIN TO REDEVELOP AS WINDS SHIFT BACK AROUND TO THE SW BUT AT
CONTINUED LIGHT SPEEDS. WAVE HEIGHTS WILL BE 2-3 FT EARLY DURING THE
RESIDUAL NE SURGE...BUT FALL TO 1-2 FT SATURDAY AFTN AND PERSIST AT
THESE AMPLITUDES THROUGH THE WIND SHIFT AND INTO THE END OF THE
PERIOD
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 300 AM FRIDAY...SW WINDS AHEAD OF A COLD FRONT WILL INCREASE
STEADILY DURING MONDAY...RISING UP TOWARDS 15 KTS LATE IN THE DAY.
AS THE COLD FRONT APPROACHES WINDS WILL EASE A BIT MONDAY
NIGHT...BUT THIS FRONT WILL LIKELY NOT REACH THE WATERS DURING
TUESDAY AND INSTEAD STALL JUST INLAND. THIS WILL CONTINUE S/SW WINDS
TUESDAY AT 10-15 KTS. SEAS WILL BE PRIMARILY 2-3 FT THROUGH THE
PERIOD WITH A SE GROUND SWELL AND WEAK WIND WAVE COMPRISING THE
SPECTRUM. LATE MONDAY AND INTO TUESDAY...SOME 12-SEC PERIOD SWELL
FROM DISTANT TROPICAL SYSTEMS MAY ENTER THE SPECTRUM...BUT WILL BE
AT 1 FT OR LESS IN AMPLITUDE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...REK/TRA
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...DL
MARINE...REK/TRA/JDW
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1208 PM CDT FRI AUG 21 2015
.UPDATE...
ISSUED AT 1210 PM CDT FRI AUG 21 2015
SMOKE CONTINUES TO SLOW TEMP RISE TODAY...AND WILL LOWER A FEW
MORE DEGREES FOR ALL AREAS. OTHERWISE...NO OTHER CHANGES NEEDED
TODAY.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 345 AM CDT FRI AUG 21 2015
FORECAST CHALLENGES WILL BE SEVERE THREAT SATURDAY AS WELL AS RAINFALL
AMOUNTS MAINLY THIS WEEKEND AND TEMPERATURES/WIND. MODELS OVERALL
IN PRETTY GOOD AGREEMENT THROUGH THE PERIOD AND WILL USE MODEL
BLEND.
CURRENT SHORTWAVE PROPAGATING EAST ACROSS SW MB INTO ONTARIO THIS
MORNING. ASSOCIATED AREA OF SHRA/ISOLD T ON NOSE OF LOW LEVEL JET
IN WARM ADVECTION ZONE. ALTHOUGH INSTABILITY AND CAPE MINIMAL A
FEW LIGHTNING STRIKES OCCURRING. CURRENT HRRR WEAKENS PCPN
THROUGH THE MORNING AND OUT OF THE FA BY MID MORNING. WILL
MAINTAIN LOW POPS BASED ON SHORT TERM MODEL GUIDANCE. THE
REMAINDER OF THIS AFTERNOON SHOULD REMAIN DRY. CONTINUED WARM
ADVECTION WILL SET UP WARM FRONTAL BOUNDARY ALONG THE
INTERNATIONAL BORDER BY THIS EVENING. WITH FA IN WARM SECTOR
TEMPERATURES SHOULD RECOVER WELL WITH MOST AREAS ABOVE AVERAGE.
TONIGHT MORE SIGNIFICANT WAVE CURRENTLY OVER BC WILL DIG INTO THE
NORTHERN ROCKIES. ASSOCIATED SURFACE LOW WILL ORGANIZE OVER THE
WESTERN DAKOTAS WITH SW-NE ORIENTED BOUNDARY SETTING UP LATER IN
THE NIGHT. WILL CONTINUE WITH CHANCE POPS ALONG THIS BOUNDARY.
TEMPERATURES WILL REMAIN MILD OVERNIGHT.
SURFACE LOW WILL LIFT NE SATURDAY AS WAVE APPROACHES. AS IT DOES
ASSOCIATED COLD FRONT WILL FOLLOW LOW AND BE ORIENTED CLOSE TO THE
VALLEY BY PRIME HEATING. CONVECTIVE PARAMETERS FAVORABLE FOR
SEVERE STORMS ALONG AND AHEAD OF THE BOUNDARY SO SEVERE POTENTIAL
WILL HINGE ON JUST WHERE BOUNDARY SETS UP. DEGREE OF CLOUD COVER
WILL GOVERN TEMPERATURES WITH COOLEST READINGS OVER THE FAR NW
WHICH WILL BE BEHIND THE COLD FRONT.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 345 AM CDT FRI AUG 21 2015
UPPER TROUGH CLOSES OFF SATURDAY NIGHT AS IT LIFTS NE. WRAP
AROUND/DEF ZONE RAIN WILL FOLLOW. AT THIS POINT MODEL GUIDANCE
SUGGESTS THAT THE BEST POTENTIAL FOR RAIN WILL BE OVER THE
NORTHERN 2/3RD OF THE FA.
SUNDAY WILL BE WINDY AND COOLER WITH DEF ZONE PCPN BAND SHIFTING
EAST ACROSS THE FA. COOLER COLUMN AND CLOUDS WILL HOLD
TEMPERATURES DOWN.
RAIN WILL MOVE OUT OF THE NE FA SUNDAY NIGHT. WINDS TO DIMINISH
BUT WILL BE A COOL NIGHT WITH MINIMUM TEMPERATURES IN THE 40S.
LONG WAVE TROUGHS WERE OFF THE WESTERN CANADIAN COAST AND THE GREAT
LAKES WITH A FLAT RIDGE OVER MT. PATTERN AMPLIFIES WITH A TROUGH
OVER THE EASTERN PACIFIC/WESTERN CANADA AND RIDGING INTO THE
NORTHERN PLAINS BY THE END OF THE PERIOD.
GFS AND ECMWF WERE IN BETTER AGREEMENT WITH TODAYS MODEL RUN THROUGH
THE PERIOD. THE ECMWF WAS SLIGHTLY FASTER THAN THE GFS. THE ECMWF
WAS VACILLATING AROUND A POINT WHILE THE GFS WAS TRENDING SLOWER
OVER THE LAST COUPLE MODEL RUNS.
NO CHANGE TO HIGH TEMPS FOR MON. HIGH TEMPS WERE DECREASED A DEGREE
OR TWO FOR TUE AND WED, AND INCREASED ZERO TO FOUR DEGREES FOR THU
FORM YESTERDAYS PACKAGE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1210 PM CDT FRI AUG 21 2015
VFR CONDITIONS FCST TO CONTINUE THROUGH THE PERIOD WITH MAINLY MID
AND HIGH LEVEL CIGS. SFC HIGH PRESSURE WILL RETREAT THIS AFTERNOON
AND EVENING...WITH WINDS BECOMING SOUTHERLY FROM 10 TO 20 MPH AHEAD
OF DEVELOPING LOW PRESSURE MOVG ACROSS THE HIGH PLAINS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...DK
SHORT TERM...VOELKER
LONG TERM...HOPPES/VOELKER
AVIATION...HOPKINS
AREA FORECAST DISCUSSION
NWS NORMAN OK
600 PM CDT FRI AUG 21 2015
.AVIATION...
EXPECT TO SEE SOME SHWR/TSTMS IMPACT MOST SITES LATER THIS EVENING
WITH ASSOCAITED MVFR CONDITIONS. WITH VFR RETURNING OVERNIGHT AND
CONT THROUGH THE DAY ON SATURDAY. MUCH LIKE TODAY... SOUTH WINDS
WILL INCREASE DURING THE DAY SATURDAY WITH GUSTS OF 20 TO 25KTS
EXPECTED BY LATE MORNING INTO THE AFTN HOURS.
30
&&
.PREV DISCUSSION... /ISSUED 218 PM CDT FRI AUG 21 2015/
.DISCUSSION...
PRIMARY FORECAST CONCERN LIES WITH THUNDERSTORM CHANCES THIS EVENING
AND OVERNIGHT.
CURRENTLY... STOUT MID-LEVEL SHORT WAVE CONTINUES TO DIG ACROSS NERN
NM/SERN CO INTO THE NRN PANHANDLES. AHEAD OF THIS WAVE... WAA HAS
INCREASED ACROSS WRN N TX INTO WRN OK... IN RESPONSE... LL CLOUDS
CONTINUE TO DISSIPATE ACROSS NRN TX/SRN INTO CENTRAL OK. FROM 15Z
FORWARD... EACH PROGRESSIVE RUN OF THE HRRR HAS BECOME MORE
AGGRESSIVE WITH CONVECTIVE DEVELOPMENT OVER THE ERN PANHANDLES AND
ACROSS WRN OK/WRN N TX INTO CENTRAL/SOUTH CENTRAL OK OVERNIGHT.
TIMING HAS BEEN RELATIVELY CONSISTENT FROM RUN TO RUN... AND SIMILAR
TO TRADITIONAL GUIDANCE FROM THE NAM/GFS/ECMWF. WITH THAT SAID...
CURRENT EXPECTATIONS IS FOR INITIAL CONVECTION TO DEVELOP OVER THE
NRN TX PH/OK PH BETWEEN 21-23Z (4-6 PM CDT)... MOVING E/SE INTO WRN
OK THROUGH 23-01Z (6-8 PM CDT). WITH CLEARING SKIES... INSTABILITY
WILL INCREASE ACROSS THE WRN TX PH/WRN OK... 1000 TO 1500 J/KG ALONG
WITH 30 TO 40KTS OF DEEP LAYER SHEAR. ASCENT FOR FORCING IS CONFINED
TO THE MID-LEVELS... 850/700MB... THEREFORE... EXPECT CONVECTION TO
BE ELEVATED... AND BUFR SOUNDINGS SUPPORT THIS... WITH LCLS BETWEEN
2000 TO 3000 FT AGL. PRIMARY CONCERN WILL BE LARGE HAIL... POSSIBLY
UP TO GOLF BALL SIZE... DAMAGING WINDS UP TO 60 MPH AND FREQUENT
LIGHTNING. LOCALLY HEAVY RAINFALL IS ALSO POSSIBLE... WITH PWATS IN
THE 75TH PERCENTILE... 1.40-1.60IN... HOWEVER... THE MID-LEVEL SHORT
WAVE IS MOVING AT A DECENT CLIP... SO HYDRO IMPACTS SHOULD BE
MINIMAL AS STORMS WILL BE MOVING OUT QUICKLY THROUGH THE EARLY
MORNING HOURS OF SATURDAY.
SATURDAY MORNING... THE CHANCE FOR STRONG TO SEVERE STORMS WILL WANE
QUICKLY THROUGH MIDNIGHT... WITH SCATTERED CONVECTION CONTINUING
ACROSS CENTRAL INTO ERN OK THROUGH DAWN. MOST OF THE REMAINING
STORMS WILL STILL RETAIN THE ABILITY TO PRODUCE 40 MPH GUSTS AND
FREQUENT LIGHTNING.
LATE SATURDAY MORNING AND AFTERNOON... SOME LINGERING SHOWERS MAY
HANG AROUND... BUT DRY WEATHER CAN BE EXPECTED AS WAA INCREASES
AGAIN AHEAD OF COLD FRONT THAT WILL BE MOVING IN FROM THE NW DURING
THE AFTN IN RESPONSE TO A STRONG H500 SHORT WAVE SWINGING ACROSS THE
NRN PLAINS. THIS FRONT WILL DROP S/SE INTO THE SRN PLAINS SAT NIGHT
THROUGH SUN MORNING... BRINGING A GOOD CHANCE OF PRECIP TO THE
REGION OVERNIGHT AS PWATS WILL RANGE FROM 1.5 TO 1.70IN AHEAD OF THE
FRONT OVERNIGHT. GUIDANCE REMAINS IN DECENT AGREEMENT... WITH THE
FRONT MOVING FAIRLY QUICKLY... PUSHING TO THE RED RIVER THROUGH
EARLY/MID MORNING. PRECIP AMOUNTS BETWEEN 0.50 AND 1.00 IN... WITH
THE BEST CHANCES ACROSS NRN OK OVERNIGHT. NO SEVERE WEATHER IS
EXPECTED AT THIS TIME... ALTHOUGH A FEW STRONGER STORMS MAY BE
CAPABLE OF 40 TO 45 MPH GUSTS.
AFTER SUNDAY... THE H500 RIDGE WILL CONTINUE TO BUILD OVER THE SWRN
U.S... WITH GOOD CONSISTENCY BETWEEN RUNS OVER THE PAST FEW DAYS.
THIS WILL BODE WELL FOR TEMPS ACROSS THE REGION... KEEPING THE SRN
PLAINS NEAR NORMAL... WITH HIGHS IN THE UPPER 80S/LOWER 90S INTO
NEXT WEEK. HOWEVER... RESIDING UNDER THE ERN EDGE OF THE RIDGE...
THERE WILL BE A NEAR DAILY CHANCE OF ISOLATED TO SCATTERED
THUNDERSTORMS ACROSS THE REGION IN RESPONSE TO A SERIES OF SHORT
WAVES TRAVERSING THE LARGER RIDGE THROUGH THE END OF NEXT WEEK. THE
BEST CHANCE FOR PRECIP NEXT WEEK WILL BE MON INTO TUE AS THE WEEKEND
FRONT LIFTS TOWARD THE RED RIVER AS A WEAK WARM FRONT... BRINGING A
CHANCE OF SHOWERS AND THUNDERSTORMS TO TEXOMA AND WRN AND CENTRAL OK.
JTK
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 71 92 71 84 / 40 10 60 30
HOBART OK 71 96 72 85 / 60 10 40 30
WICHITA FALLS TX 74 97 75 93 / 40 10 20 40
GAGE OK 69 94 65 80 / 60 0 60 20
PONCA CITY OK 72 91 67 82 / 40 20 70 10
DURANT OK 73 94 75 93 / 40 10 10 30
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORMAN OK
218 PM CDT FRI AUG 21 2015
.DISCUSSION...
PRIMARY FORECAST CONCERN LIES WITH THUNDERSTORM CHANCES THIS EVENING
AND OVERNIGHT.
CURRENTLY... STOUT MID-LEVEL SHORT WAVE CONTINUES TO DIG ACROSS NERN
NM/SERN CO INTO THE NRN PANHANDLES. AHEAD OF THIS WAVE... WAA HAS
INCREASED ACROSS WRN N TX INTO WRN OK... IN RESPONSE... LL CLOUDS
CONTINUE TO DISSIPATE ACROSS NRN TX/SRN INTO CENTRAL OK. FROM 15Z
FORWARD... EACH PROGRESSIVE RUN OF THE HRRR HAS BECOME MORE
AGGRESSIVE WITH CONVECTIVE DEVELOPMENT OVER THE ERN PANHANDLES AND
ACROSS WRN OK/WRN N TX INTO CENTRAL/SOUTH CENTRAL OK OVERNIGHT.
TIMING HAS BEEN RELATIVELY CONSISTENT FROM RUN TO RUN... AND SIMILAR
TO TRADITIONAL GUIDANCE FROM THE NAM/GFS/ECMWF. WITH THAT SAID...
CURRENT EXPECTATIONS IS FOR INITIAL CONVECTION TO DEVELOP OVER THE
NRN TX PH/OK PH BETWEEN 21-23Z (4-6 PM CDT)... MOVING E/SE INTO WRN
OK THROUGH 23-01Z (6-8 PM CDT). WITH CLEARING SKIES... INSTABILITY
WILL INCREASE ACROSS THE WRN TX PH/WRN OK... 1000 TO 1500 J/KG ALONG
WITH 30 TO 40KTS OF DEEP LAYER SHEAR. ASCENT FOR FORCING IS CONFINED
TO THE MID-LEVELS... 850/700MB... THEREFORE... EXPECT CONVECTION TO
BE ELEVATED... AND BUFR SOUNDINGS SUPPORT THIS... WITH LCLS BETWEEN
2000 TO 3000 FT AGL. PRIMARY CONCERN WILL BE LARGE HAIL... POSSIBLY
UP TO GOLF BALL SIZE... DAMAGING WINDS UP TO 60 MPH AND FREQUENT
LIGHTNING. LOCALLY HEAVY RAINFALL IS ALSO POSSIBLE... WITH PWATS IN
THE 75TH PERCENTILE... 1.40-1.60IN... HOWEVER... THE MID-LEVEL SHORT
WAVE IS MOVING AT A DECENT CLIP... SO HYDRO IMPACTS SHOULD BE
MINIMAL AS STORMS WILL BE MOVING OUT QUICKLY THROUGH THE EARLY
MORNING HOURS OF SATURDAY.
SATURDAY MORNING... THE CHANCE FOR STRONG TO SEVERE STORMS WILL WANE
QUICKLY THROUGH MIDNIGHT... WITH SCATTERED CONVECTION CONTINUING
ACROSS CENTRAL INTO ERN OK THROUGH DAWN. MOST OF THE REMAINING
STORMS WILL STILL RETAIN THE ABILITY TO PRODUCE 40 MPH GUSTS AND
FREQUENT LIGHTNING.
LATE SATURDAY MORNING AND AFTERNOON... SOME LINGERING SHOWERS MAY
HANG AROUND... BUT DRY WEATHER CAN BE EXPECTED AS WAA INCREASES
AGAIN AHEAD OF COLD FRONT THAT WILL BE MOVING IN FROM THE NW DURING
THE AFTN IN RESPONSE TO A STRONG H500 SHORT WAVE SWINGING ACROSS THE
NRN PLAINS. THIS FRONT WILL DROP S/SE INTO THE SRN PLAINS SAT NIGHT
THROUGH SUN MORNING... BRINGING A GOOD CHANCE OF PRECIP TO THE
REGION OVERNIGHT AS PWATS WILL RANGE FROM 1.5 TO 1.70IN AHEAD OF THE
FRONT OVERNIGHT. GUIDANCE REMAINS IN DECENT AGREEMENT... WITH THE
FRONT MOVING FAIRLY QUICKLY... PUSHING TO THE RED RIVER THROUGH
EARLY/MID MORNING. PRECIP AMOUNTS BETWEEN 0.50 AND 1.00 IN... WITH
THE BEST CHANCES ACROSS NRN OK OVERNIGHT. NO SEVERE WEATHER IS
EXPECTED AT THIS TIME... ALTHOUGH A FEW STRONGER STORMS MAY BE
CAPABLE OF 40 TO 45 MPH GUSTS.
AFTER SUNDAY... THE H500 RIDGE WILL CONTINUE TO BUILD OVER THE SWRN
U.S... WITH GOOD CONSISTENCY BETWEEN RUNS OVER THE PAST FEW DAYS.
THIS WILL BODE WELL FOR TEMPS ACROSS THE REGION... KEEPING THE SRN
PLAINS NEAR NORMAL... WITH HIGHS IN THE UPPER 80S/LOWER 90S INTO
NEXT WEEK. HOWEVER... RESIDING UNDER THE ERN EDGE OF THE RIDGE...
THERE WILL BE A NEAR DAILY CHANCE OF ISOLATED TO SCATTERED
THUNDERSTORMS ACROSS THE REGION IN RESPONSE TO A SERIES OF SHORT
WAVES TRAVERSING THE LARGER RIDGE THROUGH THE END OF NEXT WEEK. THE
BEST CHANCE FOR PRECIP NEXT WEEK WILL BE MON INTO TUE AS THE WEEKEND
FRONT LIFTS TOWARD THE RED RIVER AS A WEAK WARM FRONT... BRINGING A
CHANCE OF SHOWERS AND THUNDERSTORMS TO TEXOMA AND WRN AND CENTRAL OK.
JTK
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 71 92 71 84 / 40 10 60 30
HOBART OK 71 96 72 85 / 60 10 40 30
WICHITA FALLS TX 74 97 75 93 / 40 10 20 40
GAGE OK 69 94 65 80 / 60 0 60 20
PONCA CITY OK 72 91 67 82 / 40 20 70 10
DURANT OK 73 94 75 93 / 40 10 10 30
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
516 PM EDT FRI AUG 21 2015
.SYNOPSIS...
H PRESSURE WILL CONTINUE TO BUILD IN FROM THE NORTH...THOUGH MUCH
DRYING IN THE WAKE OF THE FRONTAL PASSAGE IS UNLIKELY. ANOTHER COLD
FRONT WILL CROSS THE REGION ON MONDAY...WITH A MUCH DRIER PERIOD
STARTING ON TUESDAY. ISOLATED AFTERNOON SHOWERS AND THUNDERSTORMS
WILL RETURN BY THE END OF NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 510PM FRIDAY...AREA IS CURRENTLY CLEAR OF ALL BUT THE LIGHTEST
ISOLATED SHOWERS. LATEST HRRR ALSO HAS NO NEW CONVECTION IN THE
NEAR FUTURE. CONVECTION THAT EARLIER CAMS HAD BY 18Z HAS NOT
MATERIALIZED. HAVE THUS LOWERED THE PRECIP. FORECAST FOR THE NEXT 6
HOURS.
AS OF 200 PM...HIGH PRESSURE CONTINUES TO RIDGE DOWN THE EAST
COAST IN A WEDGE-LIKE CONFIGURATION. SFC FRONT NOW STRETCHES FROM
MIDDLE GA THRU THE SC MIDLANDS...WITH NE WINDS AND RELATIVELY DRY
DEWPTS ACRS MOST OF THE AREA. PATCHY MIDLEVEL CLOUDS REMAIN ACRS
MUCH OF THE CWFA RESULTING FROM A WEAK VORT MAX DRIFTING ACRS THE
AREA. THIS DECK APPEARS THINNER THAN IT DID LATE THIS MRNG...AND AS
THE VORT MAX CONTINUES TO MOVE EAST IT SHOULD FOLLOW. A SHALLOW CU
FIELD HAS QUICKLY BROKEN OUT AS SUNSHINE RETURNS...PARTICULARLY
OVER THE MTNS OF SW NC AND NE GA...AND NOW THE UPPER SAVANNAH
RIVER VALLEY. A COUPLE SHOWERS ARE ALSO SEEN ON RADAR TO OUR
WEST. SHORT RANGE CAM GUIDANCE HAS GENERALLY OVERDONE THE STATE
OF CONVECTION THIS MORNING POSSIBLY BECAUSE THEY UNDERESTIMATED
THE RESTRICTED WARMING ASSOC WITH THE CLOUD COVER. THE HRRR HAS
TRENDED TOWARD MORE ISOLATED COVERAGE. SEEING THE RATHER WEAK
ACTIVITY UPSTREAM SUPPORTS MAINLY ISOLD RANGE POPS THIS AFTN. A
SECOND VORT MAX OVER NRN ALABAMA WILL ARRIVE THIS EVENING...AND
ENOUGH ELEVATED INSTABILITY AND LOW LEVEL MOISTURE WILL STILL BE
PRESENT FOR ISOLATED CONVECTION TO OCCUR TONIGHT OVER MUCH OF THE
AREA. DESPITE HIGH PRESSURE ALREADY HAVING BEGUN TO SETTLE INTO THE
AREA AS OF THIS AFTERNOON...APPRECIABLE DRYING DOES NOT OCCUR UNTIL
TOMORROW. ANY CONVECTIVE SHOWERS THAT OCCUR THIS AFTN OR TONIGHT ARE
LIKELY TO PRODUCE HIGH RAINFALL RATES. MIN TEMPS WILL BE SLIGHTLY
ABOVE CLIMO TONIGHT WITH A FAIR AMOUNT OF CLOUD COVER...GIVEN THE
UPPER DISTURBANCE AND MOIST FLOW INTO THE BLUE RIDGE.
SUBSIDENCE CAPPING IS EXPECTED TO KEEP CONVECTION ISOLATED OR
TOTALLY AT BAY OVER MUCH OF THE NC PIEDMONT ON SATURDAY...AND
SCATTERED AT BEST AROUND THE FRINGES OF THE AIRMASS /IN THE MTNS
AND SAVANNAH VALLEY/. THE ARRIVAL OF DRIER AIR ALOFT IMPLIES
GUSTY/STRONG WINDS MAY BE OF A BIT MORE CONCERN...AND HEAVY RAIN
A BIT LESS. MAX TEMPS AGAIN WILL BE SLIGHTLY BELOW NORMAL.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 200 PM EDT FRIDAY...THE SHORT TERM FCST PERIOD INITIALIZES
SATURDAY EVENING WITH THE UPPER PATTERN HIGHLIGHTED BY AN EASTERN
GULF ANTICYCLONE...WHILE A SHORTWAVE TROF SLIDES THROUGH THE
MIDSOUTH...WITH A DEEPER LONGWAVE TROF ADVECTING OVER THE UPPER
MIDWEST. AT THE SFC...RELATIVELY DRIER NORTHERLY FLOW WILL PREVAIL
OVER THE WESTERN CAROLINAS AND NORTHEAST GEORGIA CONSEQUENT OF
ELONGATED HIGH PRESSURE MOVING EAST OF THE SOUTHERN/CENTRAL APPS.
MODELS HINT AT ISOLATED/SCATTERED CONVECTION POSSIBLE AT FCST
INITIALIZATION ACROSS THE AREA...HOWEVER MAINLY FOCUSED OVER
THE NC/GA HIGH TERRAIN AND THE UPPER SAVANNAH RIVER VALLEY.
EXPECTING THE UPPER SHORT WAVE TO ADVECT FURTHER EAST THROUGH
THE NIGHT WARRANTING MENTIONABLE POPS THROUGH MORNING OVER THE
WEST...SPREADING EAST AND INCREASING INTO THE AFTERNOON. THUS THE
FCST FEATURES CHANCE POPS DURING THE DAY ON SUNDAY.
MEANWHILE...A COLD FRONT WILL BE MOVING THROUGH THE MID MISSISSIPPI
RIVER VALLEY INTO THE OHIO VALLEY BY EARLY MONDAY MORNING...ENTERING
THE NC HIGH TERRAIN LATE AFTERNOON TO EARLY EVENING MONDAY.
STILL SOME UNCERTAINTY AS TO HOW UNSTABLE THE AIRMASS WILL BE OUT
AHEAD OF THE FRONT HOWEVER WITH THE LATEST THE NAM COMING IN MORE SO
THAN PREVIOUS RUNS. THUS...WOULDNT BE SURPRISED TO SEE CONVECTION
IN THE WARM SECTOR MONDAY AFTERNOON AHEAD/ALONG THE FRONT.
FORTUNATELY...THE MOST ENHANCED UPPER WIND FIELD WILL BE WELL TO
THE NORTH ALONG WITH THE PRIMARY UPPER LOW. THEREFORE SOUNDINGS
FAVOR MORE OF A HAIL AND HYDRO THREAT AT THIS TIME...WITH EVEN THAT
BEING ISOLATED. POPS ON MONDAY WILL FEATURE CHANCE LEVELS OVER THE
HIGH TERRAIN TAPERING TO SLIGHT CHANCE LEVELS EAST ALONG THE I77
CORRIDOR. AS FOR HURRICANE DANNY...LATEST ADVISORY ISSUANCE FROM
NHC INDICATES SOME WEAKENING THIS WEEKEND AS IT ENCOUNTERS DRIER
AIR WITH THE CENTER OF CIRCULATION JUST OFF THE EAST COAST OF PUERTO
RICO BY MONDAY AFTERNOON...LIKELY IN THE FORM OF A TROPICAL STORM.
TEMPERATURES THROUGH THE PERIOD WILL SLOWLY MODERATE...WITH NEAR
NORMAL HIGHS FCST ON SUNDAY AND HIGHS JUST ABOVE NORMAL ON MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
OF 200 PM FRIDAY...OVERALL MODEL AGREEMENT FOR THE MEDIUM RANGE
IS ABOVE AVERAGE. THE UPPER PATTERN WILL CONTINUE TO AMPLIFY...WITH
A SUBSTANTIAL RIDGE STILL IN PLACE OVER THE WESTERN CONUS AND A
RAPIDLY DEEPENING TROUGH OVER THE EAST. AT THE SURFACE...THE
APPROACHING FRONTAL BOUNDARY WILL MOVE THROUGH THE CWFA AT THE
BEGINNING OF THE PERIOD. DESPITE THE FRONTAL PASSAGE COINCIDING WITH
PEAK HEATING...DEEP NORTHWESTERLY FLOW WILL DRIVE SOME LEVEL OF
DRYING BEFORE THE BOUNDARY ARRIVES. MODERATE INSTABILITY IS POSSIBLE
IN THE HIGHER TERRAIN...BUT IS UNIMPRESSIVE ELSEWHERE. THOUGH THERE
IS SOME QPF RESPONSE AS THE FRONT PASSES...A LACK OF DEEP MOISTURE
AND LESS THAN THRILLING SHEAR PROFILES SHOULD KEEP CHANCES OF
CONVECTION TO NO MORE THAN CHANCE OUTSIDE THE MOUNTAINS...AND
HIGH-END CHANCE IN THE HIGHER TERRAIN.
AN UNUSUALLY QUIET PERIOD...ESPECIALLY FOR THE END OF SUMMER...WILL
ARRIVE AFTER THE FRONT CROSSES THE CWA. A SURFACE HIGH WILL BUILD IN
FROM THE OHIO RIVER VALLEY...AND PWATS DROP TO WELL BELOW NORMAL. A
NORTHERLY COMPONENT IS MAINTAINED IN THE SURFACE WINDS FOR ALMOST
THE ENTIRE MEDIUM RANGE...SO KEEP A "SILENT 10" POP IN EACH
AFTERNOON FOR THE MAJORITY OF THE AREA. SLIGHT CHANCE POPS WERE USED
BORDERING COLUMBIA`S AREA...WITH ANY CHANCE AT CONVECTION FOLLOWING
THE BETTER INSTABILITY. THE UPPER PATTERN WILL FLATTEN OUT BY THE
END OF NEXT WEEK...AND THE INFLUENCE OF ATLANTIC HIGH PRESSURE WILL
BUILD BACK IN. THIS INFLUENCE WILL BE REFLECTED IN A SLIGHT
MOISTENING DUE TO AN INCREASED SOUTHERLY FLOW AT THE SURFACE. MAX
AND MIN TEMPS WILL BE NEAR CLIMO THROUGH THE PERIOD.
&&
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
AT KCLT...VFR. A PASSING UPPER DISTURBANCE THIS AFTERNOON
WILL MAINTAIN A FAIR AMOUNT OF HIGH CLOUD COVER AND LIMIT
DESTABILIZATION...SO EVEN THOUGH LOW VFR CU WILL DEVELOP THEY
ARE UNLIKELY TO BECOME DEEP ENOUGH FOR ANY PRECIP TO RESULT. HIGH
PRESSURE WILL CONTINUE TO BUILD DOWN THE EAST COAST REINFORCING
NELY WINDS...THOUGH THEY ARE EXPECTED TO VEER SLIGHTLY SOUTH OF
EAST FOR A TIME THIS EVENING. A SECOND DISTURBANCE ARRIVING TONIGHT
WILL BRING ADDITIONAL CLOUD COVER AND A BETTER CHANCE FOR LIGHT
SHOWERS...BOTH OF WHICH ARE EXPECTED TO CAUSE LITTLE IMPACT. WINDS
WILL RETURN TO NE AFTER DAYBREAK.
ELSEWHERE...IN THE WAKE OF ONE UPPER DISTURBANCE...HIGHER CLOUDS
SHOULD MOVE EAST AND RETURNING SUNSHINE WILL ALLOW CUMULUS TO
BUILD IN THEIR WAKE. ISOLD TO WIDELY SCATTERED SHRA AND PERHAPS
A TSRA OR TWO HAS PROMPTED A VCSH MENTION AT KGSP/KGMU. A SECOND
DISTURBANCE ARRIVING TONIGHT WILL BRING BETTER CHANCES TO MOST OF
THE AREA...BUT STILL ONLY VCSH WORTHY AT BEST. SOME FOG IS EXPECTED
IN MTN VALLEYS AND IN THE SAVANNAH RIVER VALLEY...TAKING KAVL/KAND
DOWN TO MVFR IN THE EARLY MRNG. POPS DIMINISH AFTER DAYBREAK AS
THE DISTURBANCE DEPARTS...BEFORE RAMPING UP AGAIN TOWARD MIDDAY
WITH DIURNAL DESTABILIZATION. WINDS WILL REFLECT THE HIGH PRESSURE
RIDGING DOWN THE EAST SIDE OF THE APPALACHIANS IN A REGIME SIMILAR
TO A CAD WEDGE...MAINLY NE OVER THE PIEDMONT AND SE AT KAVL.
OUTLOOK...DRY HIGH PRESSURE WILL MAINTAIN LOW POTENTIAL FOR MORNING
RESTRICTIONS THROUGH THE WEEKEND. A RETURN TO A TYPICAL DIURNAL
CYCLE OF CONVECTION MAY OCCUR EARLY NEXT WEEK AS A COLD FRONT
ARRIVES FROM THE NORTHWEST.
CONFIDENCE TABLE...
21-03Z 03-09Z 09-15Z 15-18Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 87%
KAVL HIGH 96% HIGH 100% HIGH 90% HIGH 82%
KHKY HIGH 100% HIGH 100% LOW 55% MED 72%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 95%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...LEV
NEAR TERM...WIMBERLEY/WJM
SHORT TERM...CDG
LONG TERM...LEV
AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
237 PM EDT FRI AUG 21 2015
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO BUILD IN FROM THE NORTH...THOUGH
MUCH DRYING IN THE WAKE OF THE FRONTAL PASSAGE IS UNLIKELY.
ANOTHER COLD FRONT WILL CROSS THE REGION ON MONDAY...WITH A MUCH
DRIER PERIOD STARTING ON TUESDAY. ISOLATED AFTERNOON SHOWERS AND
THUNDERSTORMS WILL RETURN BY THE END OF NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 230 PM...HIGH PRESSURE CONTINUES TO RIDGE DOWN THE EAST
COAST IN A WEDGE-LIKE CONFIGURATION. SFC FRONT NOW STRETCHES FROM
MIDDLE GA THRU THE SC MIDLANDS...WITH NE WINDS AND RELATIVELY DRY
DEWPTS ACRS MOST OF THE AREA. PATCHY MIDLEVEL CLOUDS REMAIN ACRS
MUCH OF THE CWFA RESULTING FROM A WEAK VORT MAX DRIFTING ACRS THE
AREA. THIS DECK APPEARS THINNER THAN IT DID LATE THIS MRNG...AND AS
THE VORT MAX CONTINUES TO MOVE EAST IT SHOULD FOLLOW. A SHALLOW CU
FIELD HAS QUICKLY BROKEN OUT AS SUNSHINE RETURNS...PARTICULARLY
OVER THE MTNS OF SW NC AND NE GA...AND NOW THE UPPER SAVANNAH
RIVER VALLEY. A COUPLE SHOWERS ARE ALSO SEEN ON RADAR TO OUR
WEST. SHORT RANGE CAM GUIDANCE HAS GENERALLY OVERDONE THE STATE
OF CONVECTION THIS MORNING POSSIBLY BECAUSE THEY UNDERESTIMATED
THE RESTRICTED WARMING ASSOC WITH THE CLOUD COVER. THE HRRR HAS
TRENDED TOWARD MORE ISOLATED COVERAGE. SEEING THE RATHER WEAK
ACTIVITY UPSTREAM SUPPORTS MAINLY ISOLD RANGE POPS THIS AFTN. A
SECOND VORT MAX OVER NRN ALABAMA WILL ARRIVE THIS EVENING...AND
ENOUGH ELEVATED INSTABILITY AND LOW LEVEL MOISTURE WILL STILL BE
PRESENT FOR ISOLATED CONVECTION TO OCCUR TONIGHT OVER MUCH OF THE
AREA. DESPITE HIGH PRESSURE ALREADY HAVING BEGUN TO SETTLE INTO THE
AREA AS OF THIS AFTERNOON...APPRECIABLE DRYING DOES NOT OCCUR UNTIL
TOMORROW. ANY CONVECTIVE SHOWERS THAT OCCUR THIS AFTN OR TONIGHT ARE
LIKELY TO PRODUCE HIGH RAINFALL RATES. MIN TEMPS WILL BE SLIGHTLY
ABOVE CLIMO TONIGHT WITH A FAIR AMOUNT OF CLOUD COVER...GIVEN THE
UPPER DISTURBANCE AND MOIST FLOW INTO THE BLUE RIDGE.
SUBSIDENCE CAPPING IS EXPECTED TO KEEP CONVECTION ISOLATED OR
TOTALLY AT BAY OVER MUCH OF THE NC PIEDMONT ON SATURDAY...AND
SCATTERED AT BEST AROUND THE FRINGES OF THE AIRMASS /IN THE MTNS
AND SAVANNAH VALLEY/. THE ARRIVAL OF DRIER AIR ALOFT IMPLIES
GUSTY/STRONG WINDS MAY BE OF A BIT MORE CONCERN...AND HEAVY RAIN
A BIT LESS. MAX TEMPS AGAIN WILL BE SLIGHTLY BELOW NORMAL.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 200 PM EDT FRIDAY...THE SHORT TERM FCST PERIOD INITIALIZES
SATURDAY EVENING WITH THE UPPER PATTERN HIGHLIGHTED BY AN EASTERN
GULF ANTICYCLONE...WHILE A SHORTWAVE TROF SLIDES THROUGH THE
MIDSOUTH...WITH A DEEPER LONGWAVE TROF ADVECTING OVER THE UPPER
MIDWEST. AT THE SFC...RELATIVELY DRIER NORTHERLY FLOW WILL PREVAIL
OVER THE WESTERN CAROLINAS AND NORTHEAST GEORGIA CONSEQUENT OF
ELONGATED HIGH PRESSURE MOVING EAST OF THE SOUTHERN/CENTRAL APPS.
MODELS HINT AT ISOLATED/SCATTERED CONVECTION POSSIBLE AT FCST
INITIALIZATION ACROSS THE AREA...HOWEVER MAINLY FOCUSED OVER
THE NC/GA HIGH TERRAIN AND THE UPPER SAVANNAH RIVER VALLEY.
EXPECTING THE UPPER SHORT WAVE TO ADVECT FURTHER EAST THROUGH
THE NIGHT WARRANTING MENTIONABLE POPS THROUGH MORNING OVER THE
WEST...SPREADING EAST AND INCREASING INTO THE AFTERNOON. THUS THE
FCST FEATURES CHANCE POPS DURING THE DAY ON SUNDAY.
MEANWHILE...A COLD FRONT WILL BE MOVING THROUGH THE MID MISSISSIPPI
RIVER VALLEY INTO THE OHIO VALLEY BY EARLY MONDAY MORNING...ENTERING
THE NC HIGH TERRAIN LATE AFTERNOON TO EARLY EVENING MONDAY.
STILL SOME UNCERTAINTY AS TO HOW UNSTABLE THE AIRMASS WILL BE OUT
AHEAD OF THE FRONT HOWEVER WITH THE LATEST THE NAM COMING IN MORE SO
THAN PREVIOUS RUNS. THUS...WOULDNT BE SURPRISED TO SEE CONVECTION
IN THE WARM SECTOR MONDAY AFTERNOON AHEAD/ALONG THE FRONT.
FORTUNATELY...THE MOST ENHANCED UPPER WIND FIELD WILL BE WELL TO
THE NORTH ALONG WITH THE PRIMARY UPPER LOW. THEREFORE SOUNDINGS
FAVOR MORE OF A HAIL AND HYDRO THREAT AT THIS TIME...WITH EVEN THAT
BEING ISOLATED. POPS ON MONDAY WILL FEATURE CHANCE LEVELS OVER THE
HIGH TERRAIN TAPERING TO SLIGHT CHANCE LEVELS EAST ALONG THE I77
CORRIDOR. AS FOR HURRICANE DANNY...LATEST ADVISORY ISSUANCE FROM
NHC INDICATES SOME WEAKENING THIS WEEKEND AS IT ENCOUNTERS DRIER
AIR WITH THE CENTER OF CIRCULATION JUST OFF THE EAST COAST OF PUERTO
RICO BY MONDAY AFTERNOON...LIKELY IN THE FORM OF A TROPICAL STORM.
TEMPERATURES THROUGH THE PERIOD WILL SLOWLY MODERATE...WITH NEAR
NORMAL HIGHS FCST ON SUNDAY AND HIGHS JUST ABOVE NORMAL ON MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 200 PM FRIDAY...OVERALL MODEL AGREEMENT FOR THE MEDIUM
RANGE IS ABOVE AVERAGE. THE UPPER PATTERN WILL CONTINUE TO
AMPLIFY...WITH A SUBSTANTIAL RIDGE STILL IN PLACE OVER THE WESTERN
CONUS AND A RAPIDLY DEEPENING TROUGH OVER THE EAST. AT THE
SURFACE...THE APPROACHING FRONTAL BOUNDARY WILL MOVE THROUGH THE
CWFA AT THE BEGINNING OF THE PERIOD. DESPITE THE FRONTAL PASSAGE
COINCIDING WITH PEAK HEATING...DEEP NORTHWESTERLY FLOW WILL DRIVE
SOME LEVEL OF DRYING BEFORE THE BOUNDARY ARRIVES. MODERATE
INSTABILITY IS POSSIBLE IN THE HIGHER TERRAIN...BUT IS
UNIMPRESSIVE ELSEWHERE. THOUGH THERE IS SOME QPF RESPONSE AS THE
FRONT PASSES...A LACK OF DEEP MOISTURE AND LESS THAN THRILLING
SHEAR PROFILES SHOULD KEEP CHANCES OF CONVECTION TO NO MORE THAN
CHANCE OUTSIDE THE MOUNTAINS...AND HIGH-END CHANCE IN THE HIGHER
TERRAIN.
AN UNUSUALLY QUIET PERIOD...ESPECIALLY FOR THE END OF SUMMER...WILL
ARRIVE AFTER THE FRONT CROSSES THE CWA. A SURFACE HIGH WILL BUILD IN
FROM THE OHIO RIVER VALLEY...AND PWATS DROP TO WELL BELOW NORMAL. A
NORTHERLY COMPONENT IS MAINTAINED IN THE SURFACE WINDS FOR ALMOST
THE ENTIRE MEDIUM RANGE...SO KEEP A "SILENT 10" POP IN EACH
AFTERNOON FOR THE MAJORITY OF THE AREA. SLIGHT CHANCE POPS WERE USED
BORDERING COLUMBIA`S AREA...WITH ANY CHANCE AT CONVECTION FOLLOWING
THE BETTER INSTABILITY. THE UPPER PATTERN WILL FLATTEN OUT BY THE
END OF NEXT WEEK...AND THE INFLUENCE OF ATLANTIC HIGH PRESSURE WILL
BUILD BACK IN. THIS INFLUENCE WILL BE REFLECTED IN A SLIGHT
MOISTENING DUE TO AN INCREASED SOUTHERLY FLOW AT THE SURFACE. MAX
AND MIN TEMPS WILL BE NEAR CLIMO THROUGH THE PERIOD.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
AT KCLT...VFR. A PASSING UPPER DISTURBANCE THIS AFTERNOON
WILL MAINTAIN A FAIR AMOUNT OF HIGH CLOUD COVER AND LIMIT
DESTABILIZATION...SO EVEN THOUGH LOW VFR CU WILL DEVELOP THEY
ARE UNLIKELY TO BECOME DEEP ENOUGH FOR ANY PRECIP TO RESULT. HIGH
PRESSURE WILL CONTINUE TO BUILD DOWN THE EAST COAST REINFORCING
NELY WINDS...THOUGH THEY ARE EXPECTED TO VEER SLIGHTLY SOUTH OF
EAST FOR A TIME THIS EVENING. A SECOND DISTURBANCE ARRIVING TONIGHT
WILL BRING ADDITIONAL CLOUD COVER AND A BETTER CHANCE FOR LIGHT
SHOWERS...BOTH OF WHICH ARE EXPECTED TO CAUSE LITTLE IMPACT. WINDS
WILL RETURN TO NE AFTER DAYBREAK.
ELSEWHERE...IN THE WAKE OF ONE UPPER DISTURBANCE...HIGHER CLOUDS
SHOULD MOVE EAST AND RETURNING SUNSHINE WILL ALLOW CUMULUS TO
BUILD IN THEIR WAKE. ISOLD TO WIDELY SCATTERED SHRA AND PERHAPS
A TSRA OR TWO HAS PROMPTED A VCSH MENTION AT KGSP/KGMU. A SECOND
DISTURBANCE ARRIVING TONIGHT WILL BRING BETTER CHANCES TO MOST OF
THE AREA...BUT STILL ONLY VCSH WORTHY AT BEST. SOME FOG IS EXPECTED
IN MTN VALLEYS AND IN THE SAVANNAH RIVER VALLEY...TAKING KAVL/KAND
DOWN TO MVFR IN THE EARLY MRNG. POPS DIMINISH AFTER DAYBREAK AS
THE DISTURBANCE DEPARTS...BEFORE RAMPING UP AGAIN TOWARD MIDDAY
WITH DIURNAL DESTABILIZATION. WINDS WILL REFLECT THE HIGH PRESSURE
RIDGING DOWN THE EAST SIDE OF THE APPALACHIANS IN A REGIME SIMILAR
TO A CAD WEDGE...MAINLY NE OVER THE PIEDMONT AND SE AT KAVL.
OUTLOOK...DRY HIGH PRESSURE WILL MAINTAIN LOW POTENTIAL FOR MORNING
RESTRICTIONS THROUGH THE WEEKEND. A RETURN TO A TYPICAL DIURNAL
CYCLE OF CONVECTION MAY OCCUR EARLY NEXT WEEK AS A COLD FRONT
ARRIVES FROM THE NORTHWEST.
CONFIDENCE TABLE...
18-24Z 00-06Z 06-12Z 12-18Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 91%
KAVL HIGH 99% HIGH 100% HIGH 80% HIGH 86%
KHKY HIGH 100% HIGH 100% HIGH 82% MED 70%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 94%
KAND HIGH 100% HIGH 100% HIGH 97% HIGH 97%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...LEV
NEAR TERM...WIMBERLEY
SHORT TERM...CDG
LONG TERM...LEV
AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
212 PM EDT FRI AUG 21 2015
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO BUILD IN FROM THE NORTH...THOUGH
MUCH DRYING IN THE WAKE OF THE FRONTAL PASSAGE IS UNLIKELY.
ANOTHER COLD FRONT WILL CROSS THE REGION ON MONDAY...WITH A MUCH
DRIER PERIOD STARTING ON TUESDAY. ISOLATED AFTERNOON SHOWERS AND
THUNDERSTORMS WILL RETURN BY THE END OF NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 200 PM...PATCHY MIDLEVEL CLOUDS REMAIN ACRS MUCH OF THE
CWFA RESULTING FROM A WEAK VORT MAX DRIFTING ACRS THE AREA. THIS
DECK APPEARS THINNER THAN IT DID LATE THIS MRNG...AND AS THE VORT
MAX CONTINUES TO MOVE EAST IT SHOULD FOLLOW. A SHALLOW CU FIELD
HAS QUICKLY BROKEN OUT AS SUNSHINE RETURNS...PARTICULARLY OVER
THE MTNS OF SW NC AND NE GA...AND NOW THE UPPER SAVANNAH RIVER
VALLEY. A COUPLE SHOWERS ARE ALSO SEEN ON RADAR TO OUR WEST. SHORT
RANGE CAM GUIDANCE HAS GENERALLY OVERDONE THE STATE OF CONVECTION
THIS MORNING POSSIBLY BECAUSE THEY UNDERESTIMATED THE RESTRICTED
WARMING ASSOC WITH THE CLOUD COVER. THE HRRR HAS TRENDED TOWARD
MORE ISOLATED COVERAGE. SEEING THE RATHER WEAK ACTIVITY UPSTREAM
SUPPORTS MAINLY ISOLD RANGE POPS THIS AFTN. A SECOND VORT MAX
OVER NRN ALABAMA WILL ARRIVE THIS EVENING...AND ENOUGH ELEVATED
INSTABILITY AND LOW LEVEL MOISTURE WILL STILL BE PRESENT FOR
ISOLATED CONVECTION TO OCCUR TONIGHT OVER MUCH OF THE AREA.
MORE DETAILS TO COME IN DISCUSSION WITH AFTN PACKAGE DURING THE
NEXT HOUR.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 200 PM EDT FRIDAY...THE SHORT TERM FCST PERIOD INITIALIZES
SATURDAY EVENING WITH THE UPPER PATTERN HIGHLIGHTED BY AN EASTERN
GULF ANTICYCLONE...WHILE A SHORTWAVE TROF SLIDES THROUGH THE
MIDSOUTH...WITH A DEEPER LONGWAVE TROF ADVECTING OVER THE UPPER
MIDWEST. AT THE SFC...RELATIVELY DRIER NORTHERLY FLOW WILL PREVAIL
OVER THE WESTERN CAROLINAS AND NORTHEAST GEORGIA CONSEQUENT OF
ELONGATED HIGH PRESSURE MOVING EAST OF THE SOUTHERN/CENTRAL APPS.
MODELS HINT AT ISOLATED/SCATTERED CONVECTION POSSIBLE AT FCST
INITIALIZATION ACROSS THE AREA...HOWEVER MAINLY FOCUSED OVER
THE NC/GA HIGH TERRAIN AND THE UPPER SAVANNAH RIVER VALLEY.
EXPECTING THE UPPER SHORT WAVE TO ADVECT FURTHER EAST THROUGH
THE NIGHT WARRANTING MENTIONABLE POPS THROUGH MORNING OVER THE
WEST...SPREADING EAST AND INCREASING INTO THE AFTERNOON. THUS THE
FCST FEATURES CHANCE POPS DURING THE DAY ON SUNDAY.
MEANWHILE...A COLD FRONT WILL BE MOVING THROUGH THE MID MISSISSIPPI
RIVER VALLEY INTO THE OHIO VALLEY BY EARLY MONDAY MORNING...ENTERING
THE NC HIGH TERRAIN LATE AFTERNOON TO EARLY EVENING MONDAY.
STILL SOME UNCERTAINTY AS TO HOW UNSTABLE THE AIRMASS WILL BE OUT
AHEAD OF THE FRONT HOWEVER WITH THE LATEST THE NAM COMING IN MORE SO
THAN PREVIOUS RUNS. THUS...WOULDNT BE SURPRISED TO SEE CONVECTION
IN THE WARM SECTOR MONDAY AFTERNOON AHEAD/ALONG THE FRONT.
FORTUNATELY...THE MOST ENHANCED UPPER WIND FIELD WILL BE WELL TO
THE NORTH ALONG WITH THE PRIMARY UPPER LOW. THEREFORE SOUNDINGS
FAVOR MORE OF A HAIL AND HYDRO THREAT AT THIS TIME...WITH EVEN THAT
BEING ISOLATED. POPS ON MONDAY WILL FEATURE CHANCE LEVELS OVER THE
HIGH TERRAIN TAPERING TO SLIGHT CHANCE LEVELS EAST ALONG THE I77
CORRIDOR. AS FOR HURRICANE DANNY...LATEST ADVISORY ISSUANCE FROM
NHC INDICATES SOME WEAKENING THIS WEEKEND AS IT ENCOUNTERS DRIER
AIR WITH THE CENTER OF CIRCULATION JUST OFF THE EAST COAST OF PUERTO
RICO BY MONDAY AFTERNOON...LIKELY IN THE FORM OF A TROPICAL STORM.
TEMPERATURES THROUGH THE PERIOD WILL SLOWLY MODERATE...WITH NEAR
NORMAL HIGHS FCST ON SUNDAY AND HIGHS JUST ABOVE NORMAL ON MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 200 PM FRIDAY...OVERALL MODEL AGREEMENT FOR THE MEDIUM
RANGE IS ABOVE AVERAGE. THE UPPER PATTERN WILL CONTINUE TO
AMPLIFY...WITH A SUBSTANTIAL RIDGE STILL IN PLACE OVER THE WESTERN
CONUS AND A RAPIDLY DEEPENING TROUGH OVER THE EAST. AT THE
SURFACE...THE APPROACHING FRONTAL BOUNDARY WILL MOVE THROUGH THE
CWFA AT THE BEGINNING OF THE PERIOD. DESPITE THE FRONTAL PASSAGE
COINCIDING WITH PEAK HEATING...DEEP NORTHWESTERLY FLOW WILL DRIVE
SOME LEVEL OF DRYING BEFORE THE BOUNDARY ARRIVES. MODERATE
INSTABILITY IS POSSIBLE IN THE HIGHER TERRAIN...BUT IS
UNIMPRESSIVE ELSEWHERE. THOUGH THERE IS SOME QPF RESPONSE AS THE
FRONT PASSES...A LACK OF DEEP MOISTURE AND LESS THAN THRILLING
SHEAR PROFILES SHOULD KEEP CHANCES OF CONVECTION TO NO MORE THAN
CHANCE OUTSIDE THE MOUNTAINS...AND HIGH-END CHANCE IN THE HIGHER
TERRAIN.
AN UNUSUALLY QUIET PERIOD...ESPECIALLY FOR THE END OF SUMMER...WILL
ARRIVE AFTER THE FRONT CROSSES THE CWA. A SURFACE HIGH WILL BUILD IN
FROM THE OHIO RIVER VALLEY...AND PWATS DROP TO WELL BELOW NORMAL. A
NORTHERLY COMPONENT IS MAINTAINED IN THE SURFACE WINDS FOR ALMOST
THE ENTIRE MEDIUM RANGE...SO KEEP A "SILENT 10" POP IN EACH
AFTERNOON FOR THE MAJORITY OF THE AREA. SLIGHT CHANCE POPS WERE USED
BORDERING COLUMBIA`S AREA...WITH ANY CHANCE AT CONVECTION FOLLOWING
THE BETTER INSTABILITY. THE UPPER PATTERN WILL FLATTEN OUT BY THE
END OF NEXT WEEK...AND THE INFLUENCE OF ATLANTIC HIGH PRESSURE WILL
BUILD BACK IN. THIS INFLUENCE WILL BE REFLECTED IN A SLIGHT
MOISTENING DUE TO AN INCREASED SOUTHERLY FLOW AT THE SURFACE. MAX
AND MIN TEMPS WILL BE NEAR CLIMO THROUGH THE PERIOD.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AT KCLT...VFR. A PASSING UPPER DISTURBANCE THIS AFTERNOON
WILL MAINTAIN A FAIR AMOUNT OF HIGH CLOUD COVER AND LIMIT
DESTABILIZATION...SO EVEN THOUGH LOW VFR CU WILL DEVELOP THEY
ARE UNLIKELY TO BECOME DEEP ENOUGH FOR ANY PRECIP TO RESULT. HIGH
PRESSURE WILL CONTINUE TO BUILD DOWN THE EAST COAST REINFORCING
NELY WINDS...THOUGH THEY ARE EXPECTED TO VEER SLIGHTLY SOUTH OF
EAST FOR A TIME THIS EVENING. A SECOND DISTURBANCE ARRIVING TONIGHT
WILL BRING ADDITIONAL CLOUD COVER AND A BETTER CHANCE FOR LIGHT
SHOWERS...BOTH OF WHICH ARE EXPECTED TO CAUSE LITTLE IMPACT. WINDS
WILL RETURN TO NE AFTER DAYBREAK.
ELSEWHERE...IN THE WAKE OF ONE UPPER DISTURBANCE...HIGHER CLOUDS
SHOULD MOVE EAST AND RETURNING SUNSHINE WILL ALLOW CUMULUS TO
BUILD IN THEIR WAKE. ISOLD TO WIDELY SCATTERED SHRA AND PERHAPS
A TSRA OR TWO HAS PROMPTED A VCSH MENTION AT KGSP/KGMU. A SECOND
DISTURBANCE ARRIVING TONIGHT WILL BRING BETTER CHANCES TO MOST OF
THE AREA...BUT STILL ONLY VCSH WORTHY AT BEST. SOME FOG IS EXPECTED
IN MTN VALLEYS AND IN THE SAVANNAH RIVER VALLEY...TAKING KAVL/KAND
DOWN TO MVFR IN THE EARLY MRNG. POPS DIMINISH AFTER DAYBREAK AS
THE DISTURBANCE DEPARTS...BEFORE RAMPING UP AGAIN TOWARD MIDDAY
WITH DIURNAL DESTABILIZATION. WINDS WILL REFLECT THE HIGH PRESSURE
RIDGING DOWN THE EAST SIDE OF THE APPALACHIANS IN A REGIME SIMILAR
TO A CAD WEDGE...MAINLY NE OVER THE PIEDMONT AND SE AT KAVL.
OUTLOOK...DRY HIGH PRESSURE WILL MAINTAIN LOW POTENTIAL FOR MORNING
RESTRICTIONS THROUGH THE WEEKEND. A RETURN TO A TYPICAL DIURNAL
CYCLE OF CONVECTION MAY OCCUR EARLY NEXT WEEK AS A COLD FRONT
ARRIVES FROM THE NORTHWEST.
CONFIDENCE TABLE...
18-24Z 00-06Z 06-12Z 12-18Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 91%
KAVL HIGH 99% HIGH 100% HIGH 80% HIGH 86%
KHKY HIGH 100% HIGH 100% HIGH 82% MED 70%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 94%
KAND HIGH 100% HIGH 100% HIGH 97% HIGH 97%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...LEV
NEAR TERM...WIMBERLEY
SHORT TERM...CDG
LONG TERM...LEV
AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
603 PM CDT FRI AUG 21 2015
.DISCUSSION...SEE 00Z AVIATION DISCUSSION.
&&
.AVIATION...CONVECTION COMING TO AN END AND/OR MOVING OUT OF
AREA. THINK KLRD WILL NOT SEE ANYTHING...BUT WILL MAKE ANY CHANGE
IF NEEDED. THINK WITH MID/HIGH CLOUD COVER STILL EXPECTED...MVFR
CIGS MAY BE HARD TO COME BY EXCEPT AT KVCT...WHERE MVFR CIGS
COULD RESULT DUE TO SUSTAINED FLOW FROM THE GULF. OTHERWISE...WILL
KEEP MVFR CIGS (TEMPO) IN KALI AND KLRD BEFORE 14Z (NEXT
FORECASTER CAN DECIDE)...THEN SHOULD HAVE VFR. WITH TROUGH TO
EAST AND WINDS KICKING UP...THINK CONVECTION WILL BE VERY LIMITED.
WILL MENTION VCSH/VCTS FOR KVCT AND KCRP WHERE MOISTURE IS BETTER
BUT NOTHING ANYWHERE ELSE (AND NO TEMPOS OR PROB30). SOUTH WINDS
KICK UP ON SATURDAY AFTER 15Z...AND BECOME SSE IN THE AFTERNOON
BEHIND THE SEA-BREEZE.
&&
.PREV DISCUSSION... /ISSUED 329 PM CDT FRI AUG 21 2015/
SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)...ATMOSPHERE HAS
RECENTLY RECOVERED FROM CONVECTION EARLIER THIS MORNING. SHOWERS
AND THUNDERSTORMS ARE NOW BEGINNING TO DEVELOP ALONG THE SEA
BREEZE. A FEW OF THESE THUNDERSTORMS HAVE THE POTENTIAL TO BECOME
STRONG AS MLCAPES ARE AOA 2000 J/KG PER SPC MESOANALYSIS PAGE.
GUSTY WINDS AND LOCALLY HEAVY DOWNPOURS WOULD BE THE MAIN IMPACTS
FROM THESE STORMS. MOST OF THIS ACTIVITY SHOULD BE DIURNALLY
DRIVEN AND LATEST RUN OF THE HRRR SUPPORTS THIS. WILL ONLY CARRY
20 POPS AFTER 00Z. AS WITH THE LAST COUPLE OF MORNINGS...
CONVECTION MAY REDEVELOP OVER THE GULF WATERS LATE TONIGHT INTO
EARLY SATURDAY MORNING. SHOWERS AND STORMS WILL THEN MOVE INLAND
WITH SEA BREEZE DURING THE AFTERNOON...WHICH IS HANDLED WELL IN
THE CURRENT FORECAST. TEMPERATURES WILL REBOUND ON SATURDAY WITH
HIGHS NEAR 100 OVER THE RIO GRANDE PLAINS TO LOWER/MIDDLE 90S
ACROSS THE COASTAL BEND. OVERNIGHT LOWS WILL CONTINUE TO BE ON THE
WARM SIDE...WITH TEMPS IN THE MID/UPPER 70S AND LOWER 80S ALONG
THE IMMEDIATE COAST.
LONG TERM (SUNDAY THROUGH FRIDAY)...MID LEVEL HIGH PRESSURE ACROSS
THE DESERT SOUTHWEST AND ACROSS THE GULF BEGIN TO MERGE TOGETHER
ACROSS THE SOUTHERN PLAINS SUNDAY...ALLOWING FOR RIDGING TO BUILD
ACROSS SOUTH TEXAS. REMNANTS OF THE EARLIER TROUGH LIFT TO THE NORTH
AND EAST...BUT SEND OUT AN IMPULSE OF ENERGY SOUTHWARD MONDAY. AT
THE SURFACE...LOW PRESSURE ACROSS THE HIGH PLAINS SWINGS EAST
PUSHING A COLD FRONT THROUGH THE CENTRAL PLAINS AND GREAT LAKES
REGION. ALTHOUGH THE MAIN FRONT IS NOT EXPECTED TO MOVE THROUGH
SOUTH TEXAS...WITH THE MID LEVEL IMPULSE WILL AIDING IN FURTHER
SOUTHEASTWARD PROGRESSION OF THE FRONT...AND HIGH PRESSURE WILL
BEGIN TO BUILD INTO THE SOUTHERN STATES. MOISTURE POOLING ALONG THE
SOUTHERN PERIPHERY OF THE HIGH WITH PWATS NEAR 1.9 INCHES...WILL
BRING RAIN CHANCES TUESDAY AND WEDNESDAY. THIS BOUNDARY WILL ALLOW
FOR WINDS TO BECOME LIGHT AND VARIABLE BY TUESDAY...WITH THE COASTAL
PLAINS WINDS MORE INFLUENCED ON DIURNAL THERMAL DIFFERENCES...WITH A
LIGHT LAND BREEZE OVERNIGHT SWITCHING OUT OF THE EAST TO SOUTHEAST
IN THE AFTERNOON DUE TO THE SEA BREEZE. A MORE PERSISTENT
SOUTHEASTERLY FLOW WILL REDEVELOP HEADING INTO THURSDAY NIGHT.
NOTICEABLE DIURNAL FLUCTUATIONS WITH TEMPERATURES ARE ALSO
EXPECTED...ESPECIALLY AFTER WEDNESDAY...AS THE DRIER AIR AND CLEARER
SKIES SHOULD CONTINUE TO ALLOW DAYTIME TEMPS TO REACH INTO THE MID
TO UPPER 90S AND ALSO RESULT IN OVERNIGHT LOWS DIPPING INTO THE
LOWER 70S.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 79 93 79 94 76 / 20 20 10 20 10
VICTORIA 76 94 76 96 75 / 20 30 10 20 10
LAREDO 78 100 78 101 77 / 20 20 10 10 10
ALICE 76 96 76 96 75 / 20 30 10 20 10
ROCKPORT 80 91 81 91 79 / 20 20 10 20 10
COTULLA 77 99 77 100 76 / 20 20 10 10 10
KINGSVILLE 78 95 78 96 76 / 20 20 10 20 10
NAVY CORPUS 80 89 81 91 80 / 20 20 10 20 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
GW/86...SHORT TERM
GW/86...LONG TERM
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
335 PM CDT FRI AUG 21 2015
.SHORT TERM...
(Tonight and Saturday)
Skies were mostly sunny across West Central Texas this afternoon
with south winds of 10 to 15 mph. The conditions were humid with
dewpoints in the 60s at 19Z. Temperatures across the area were in
the lower to mid 90s. Keeping an eye on a vort max (per WV
imagery) over southeast Colorado, with subtle trough axis
extending south into west Texas.
The combination of mid and upper ascent from the upper level
feature, moderate instability and a surface trough will lead to
scattered thunderstorms developing across the Texas Panhandle and
South Plains late this afternoon and evening. All of the
convective allowing models (TX Tech WRF, HRRR and 4km NMM)
indicate scattered cells merging into a few small convective
complexes and moving east-southeast toward western Oklahoma and
northwest Texas this evening into the early morning hours. The Big
Country has the best chance of seeing thunderstorms tonight,
mainly after 02Z. A few storms may produce strong wind gusts along
with dangerous lightning. Going with slight chance to chance Pops
generally north of Sterling City to Brownwood line for tonight,
with the highest numbers north of the I-20 corridor. Lows will be
70 to 75.
For Saturday, going with a dry and hot forecast as low level
southerly flow will persist. Highs will be 95 to 100. There will
be widespread low clouds across much of the area during the
morning, mostly dissipating by 17Z.
21
.LONG TERM...
(Saturday night through Friday)
Generally quiet weather conditions are anticipated Saturday night.
The low-level jet will intensify by mid-evening, keeping southerly
winds up at 10-15 mph overnight. This will help maintain a moist
boundary layer and keep overnight lows in the mid 70s. We may also
see low stratus develop over the Hill Country, but its northward
extent should remain limited. A cold front will move south across
the South Plains early Sunday and is expected to move into the Big
Country during the afternoon hours. Temperatures across the Big
Country will depend on how fast (and how far south) the front
advances on Sunday afternoon, but for now it appears that highs
will be in the mid to upper 90s across most of the area.
There is a chance for showers and thunderstorms, mainly along and
north of the front (across the Big Country), Sunday afternoon.
This boundary is forecast to move slowly south Sunday night and
early Monday, eventually stalling between I-10 and I-20. Again,
the best rain chances will be focused along and north of the
front. However, with an east-northeast steering flow, slight
chance PoPs were warranted farther south and west of the boundary,
covering most of the CWA. Temperatures should be a few degrees
cooler on Monday, and may need to be lowered a few degrees
further.
Rain chances will continue areawide on Tuesday as the quasi-
stationary front persists over the CWA. Temperatures should again
be in the vicinity of climatology with lows in the low/mid 70s
and highs in the mid 90s. By midweek, the subtropical ridge is
expected to become the dominate synoptic feature over the High
Plains. This should result in dry conditions Wednesday and
Thursday, with temperatures likely moving back into the mid/upper
90s. Both the ECMWF and GFS indicate a fairly potent shortwave
moving southeast into the Southern Plains Thursday night into
Friday. This could result in additional rain chances, but the
forecast was left dry for now. Will continue to watch how this
feature is handled by subsequent model runs.
Johnson
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 73 98 75 96 / 20 5 5 20
San Angelo 73 100 75 99 / 10 5 0 10
Junction 73 97 75 98 / 10 5 0 5
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
21/25
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
329 PM CDT FRI AUG 21 2015
.SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)...ATMOSPHERE HAS
RECENTLY RECOVERED FROM CONVECTION EARLIER THIS MORNING. SHOWERS
AND THUNDERSTORMS ARE NOW BEGINNING TO DEVELOP ALONG THE SEA
BREEZE. A FEW OF THESE THUNDERSTORMS HAVE THE POTENTIAL TO BECOME
STRONG AS MLCAPES ARE AOA 2000 J/KG PER SPC MESOANALYSIS PAGE.
GUSTY WINDS AND LOCALLY HEAVY DOWNPOURS WOULD BE THE MAIN IMPACTS
FROM THESE STORMS. MOST OF THIS ACTIVITY SHOULD BE DIURNALLY
DRIVEN AND LATEST RUN OF THE HRRR SUPPORTS THIS. WILL ONLY CARRY
20 POPS AFTER 00Z. AS WITH THE LAST COUPLE OF MORNINGS...
CONVECTION MAY REDEVELOP OVER THE GULF WATERS LATE TONIGHT INTO
EARLY SATURDAY MORNING. SHOWERS AND STORMS WILL THEN MOVE INLAND
WITH SEA BREEZE DURING THE AFTERNOON...WHICH IS HANDLED WELL IN
THE CURRENT FORECAST. TEMPERATURES WILL REBOUND ON SATURDAY WITH
HIGHS NEAR 100 OVER THE RIO GRANDE PLAINS TO LOWER/MIDDLE 90S
ACROSS THE COASTAL BEND. OVERNIGHT LOWS WILL CONTINUE TO BE ON THE
WARM SIDE...WITH TEMPS IN THE MID/UPPER 70S AND LOWER 80S ALONG
THE IMMEDIATE COAST.
&&
.LONG TERM (SUNDAY THROUGH FRIDAY)...MID LEVEL HIGH PRESSURE ACROSS
THE DESERT SOUTHWEST AND ACROSS THE GULF BEGIN TO MERGE TOGETHER
ACROSS THE SOUTHERN PLAINS SUNDAY...ALLOWING FOR RIDGING TO BUILD
ACROSS SOUTH TEXAS. REMNANTS OF THE EARLIER TROUGH LIFT TO THE NORTH
AND EAST...BUT SEND OUT AN IMPULSE OF ENERGY SOUTHWARD MONDAY. AT
THE SURFACE...LOW PRESSURE ACROSS THE HIGH PLAINS SWINGS EAST
PUSHING A COLD FRONT THROUGH THE CENTRAL PLAINS AND GREAT LAKES
REGION. ALTHOUGH THE MAIN FRONT IS NOT EXPECTED TO MOVE THROUGH
SOUTH TEXAS...WITH THE MID LEVEL IMPULSE WILL AIDING IN FURTHER
SOUTHEASTWARD PROGRESSION OF THE FRONT...AND HIGH PRESSURE WILL
BEGIN TO BUILD INTO THE SOUTHERN STATES. MOISTURE POOLING ALONG THE
SOUTHERN PERIPHERY OF THE HIGH WITH PWATS NEAR 1.9 INCHES...WILL
BRING RAIN CHANCES TUESDAY AND WEDNESDAY. THIS BOUNDARY WILL ALLOW
FOR WINDS TO BECOME LIGHT AND VARIABLE BY TUESDAY...WITH THE COASTAL
PLAINS WINDS MORE INFLUENCED ON DIURNAL THERMAL DIFFERENCES...WITH A
LIGHT LAND BREEZE OVERNIGHT SWITCHING OUT OF THE EAST TO SOUTHEAST
IN THE AFTERNOON DUE TO THE SEA BREEZE. A MORE PERSISTENT
SOUTHEASTERLY FLOW WILL REDEVELOP HEADING INTO THURSDAY NIGHT.
NOTICEABLE DIURNAL FLUCTUATIONS WITH TEMPERATURES ARE ALSO
EXPECTED...ESPECIALLY AFTER WEDNESDAY...AS THE DRIER AIR AND CLEARER
SKIES SHOULD CONTINUE TO ALLOW DAYTIME TEMPS TO REACH INTO THE MID
TO UPPER 90S AND ALSO RESULT IN OVERNIGHT LOWS DIPPING INTO THE
LOWER 70S.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 79 93 79 94 76 / 20 20 10 20 10
VICTORIA 76 94 76 96 75 / 20 30 10 20 10
LAREDO 78 100 78 101 77 / 20 20 10 10 10
ALICE 76 96 76 96 75 / 20 30 10 20 10
ROCKPORT 80 91 81 91 79 / 20 20 10 20 10
COTULLA 77 99 77 100 76 / 20 20 10 10 10
KINGSVILLE 78 95 78 96 76 / 20 20 10 20 10
NAVY CORPUS 80 89 81 91 80 / 20 20 10 20 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
TB/78...SHORT TERM
CB/85...LONG TERM
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
319 PM CDT FRI AUG 21 2015
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...UPPER LEVEL TROUGH
REMAINS OVER THE AREA PUMPING IN HIGH LEVELS OF MOISTURE INTO THE
AREA. IN FACT...12Z BRO SOUNDING SHOWED PWATS OF 2.3 INCHES. EARLY
MORNING MID/HIGH CLOUDS STUNTED DIURNAL TEMPERATURE RISE IN THE
MID/LOWER VALLEY SO ADJUSTED HOURLY TEMPERATURE GRIDS DOWN AND
SHAVED A DEGREE OF THE HIGHS. STILL EXPECT 90S TODAY WITH UPPER 90S
OUT IN OUR WESTERN SECTIONS. CUMULUS FIELD IS SLOW TO DEVELOP AND IS
NOW BECOMING AGITATED ACROSS THE RANCHLANDS OF BROOKS AND EASTERN
JIM HOGG COUNTIES. IN THE VALLEY...JUST NOW BEGINNING TO SEE CUMULUS
DEVELOPMENT UNDERNEATH REMAINING MID/HIGH CLOUD DECKS. MOS GUIDANCE
HAS LOWERED POPS IN THE VALLEY AND HAVE FOLLOWED SUIT AND HAVE LEFT
INHERITED POPS AS IS FOR THIS AFTERNOON. HRRR SHOWS DEVELOPMENT
IMMINENT IN THE RANCHLANDS WITH SHOWERS/STORMS MOVING WESTWARD WITH
TIME INTO OUR WESTERN SECTIONS EARLY THIS EVENING BEFORE DISSIPATING
BY MID EVENING. OVERNIGHT CONVECTION WILL DEVELOP OVER THE COASTAL
WATERS BUT SHOULD NOT BE AS WIDESPREAD AS LAST NIGHT. LOW/MID CLOUDS
EXPECTED TO DEVELOP OVERNIGHT WITH MOSTLY CLOUDY SKIES BY DAYBREAK
HOLDING UP LOW TEMPERATURES CLOSER TO 80 DEGREES IN THE VALLEY.
UPPER TROUGH WEAKENS SATURDAY AND BEING REPLACED BY EXPANDING UPPER
LEVEL RIDGING AND LOWER PWATS LEADING TO LOWER CHANCES FOR
PRECIPITATION SATURDAY AND SATURDAY NIGHT. TIME HEIGHTS AND CROSS
SECTIONS DEPICT MAINLY LOW LEVEL MOISTURE WITH A DRYING MID LEVEL
COLUMN. THERE IS A CHANCE FOR A FEW SHOWERS SATURDAY BUT SHOULD
REMAIN ISOLATED. THERE WILL AN UPTICK IN THE WINDS WITH SFC HIGH
PRESSURE IN THE NORTHERN GULF AND LOW PRESSURE ACROSS THE HIGH
PLAINS. HIGH TEMPERATURES WILL BE WARMER AS WELL WITH HIGHS AROUND
100 IN THE FAR WEST TO MID 90S IN THE LOWER VALLEY.
.LONG TERM /SUNDAY THROUGH FRIDAY/...THE 500 MB RIDGING WILL
BUILD OVER THE REGION THROUGHOUT NEXT WEEK AS TROFFING BUILDS
OVER THE EASTERN STATES. THE GFS PRODUCES A DRIER SOLUTION VERSUS
THE ECMWF WITH THE EURO MODEL BRINGING A PRETTY STRONG 500 MB VORT
MAX AROUND THE EAST SIDE OF THE RIDGE WHICH CRANKS OUT MUCH HIGHER
POPS FOR THE RGV AROUND MIDWEEK. THE GFS HAS BEEN CONSISTENTLY DRY
OVER THE LAST SEVERAL RUNS SO AM A LITTLE SCEPTICAL OF THE WETTER
ECMWF SOLUTION AT THIS TIME. WILL SEE IF FUTURE RUNS OF THE ECMWF
MAINTAIN THE WET BIAS BEFORE JUMPING TO HIGHER POPS IN THE LONGER
RANGE. SO WILL GO WITH SLGT CHC POPS AT THIS TIME. SINCE
CONFIDENCE LEVEL IN THE LONGER RANGE NUMERICAL GUIDANCE IS A BIT
LOWER TODAY WILL OPT FOR A GENERAL BLEND OF THE GFS MEX MOS TEMPS
AND THE ECMWF TEMPS.
&&
.MARINE...NOW THROUGH SATURDAY NIGHT...SEAS WERE NEAR 3 FEET WITH
SOUTHEAST WINDS NEAR 14 KNOTS AT BUOY020 THIS AFTERNOON. MODERATE
SOUTHEAST WINDS WILL PREVAIL ACROSS THE COASTAL WATERS AS HIGH
PRESSURE ACROSS THE NORTHERN GULF OF MEXICO AND LOW PRESSURE ACROSS
WEST TEXAS WILL KEEP A STEADY SOUTHEAST WIND GOING ACROSS THE
COASTAL WATERS. WINDS AND SEAS WILL BE HIGHER IN AND AROUND AND
SHOWERS AND STORMS.
SUNDAY THROUGH WEDNESDAY...A STATIONARY FRONT WILL DRIFT SOUTH
OVER THE GULF COAST AND THE NORTHERN GULF OF MEXICO THROUGHOUT
EARLY NEXT WEEK. AS THIS FRONT SAGS SOUTHWARDS THE PGF WILL WEAKEN
SOMEWHAT ALLOWING FOR FAIRLY LOW WINDS AND SEAS TO PREVAIL ACROSS
THE BAY AND GULF WATERS. NO SCA CONDITIONS EXPECTED THROUGH
WEDNESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 80 94 80 92 / 20 20 10 10
BROWNSVILLE 79 94 79 93 / 20 20 10 10
HARLINGEN 79 97 79 96 / 20 20 10 10
MCALLEN 79 98 80 99 / 20 20 10 10
RIO GRANDE CITY 78 99 78 100 / 30 20 10 10
SOUTH PADRE ISLAND 81 88 81 87 / 20 20 10 20
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
SHORT TERM...55
LONG TERM...60
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1237 PM CDT FRI AUG 21 2015
.AVIATION...
AFTER SPENDING MUCH OF THE MORNING IN IFR CONDITIONS ACROSS THE
I-35 CORRIDOR AND MVFR CONDITIONS AT DRT CLOUDS ARE BEGINNING TO
BREAK. AS OF A FEW MOMENTS AGO MVFR CONDITIONS NOW PREVAIL AT ALL
4 TERMINALS. THESE CIGS SHOULD STICK AROUND FOR ANOTHER HOUR OR
TWO BUT CLOUDS ARE THINNING FROM WEST TO EAST SO VFR CONDITIONS
SHOULD BREAK OUT AT ALL TERMINALS BY 20Z.
MORNING RAINFALL HAS MOVED NORTH OF AUS AND PRECIPITATION TO THE
SOUTH OF AUS AND EAST OF SAT SHOWS SIGNS OF WEAKENING. WILL NOT
CARRY ANY MENTION OF PRECIPITATION IN THE AFTERNOON TAFS AS
CHANCES WILL BE DECREASING THROUGH THE DAY.
WINDS WILL BE SOUTHEASTERLY THROUGH THE TAF PERIOD. WITH THE SUN
HELPING TO MIX OUT SOME MOISTURE THIS AFTERNOON SHOULD NOT SEE A
REPEAT OF THIS MORNINGS CIGS. WILL SEE MORNING MVFR STRATUS THOUGH
BEGINNING AROUND 09Z AND BREAKING AROUND 17Z SATURDAY MORNING AT
THE I-35 TERMINALS. DRT MAY SEE SOME HIGH END MVFR STRATUS AS
WELL.
&&
.PREV DISCUSSION... /ISSUED 935 AM CDT FRI AUG 21 2015/
UPDATE...
EARLY MORNING SHOWERS AND THUNDERSTORMS OVER THE COASTAL AREAS HAS
SENT AN OUTFLOW THAT GENERATED SHOWERS AND THUNDERSTORMS OVER THE
EASTERN PARTS OF SOUTH CENTRAL TEXAS. HAVE BOOSTED POPS 10 TO 20
PERCENT ACROSS AREAS EAST OF I-35 TO ACROSS THE AUSTIN AREA INTO
THE NORTHEASTERN HILL COUNTRY. DUE TO CLOUDS AND RAIN LINGERING
INTO THE AFTERNOON DUE TO BEING ON THE EASTERN SIDE OF THE MID TO
UPPER LEVEL SHEAR AXIS...HAVE ALSO LOWERED TEMPERATURES SLIGHTLY.
REMAINDER OF SOUTH CENTRAL TEXAS FORECAST IS ON TRACK.
PREV DISCUSSION... /ISSUED 650 AM CDT FRI AUG 21 2015/
AVIATION.../12Z TAF CYCLE/
LOWER CIGS HAVE FILLED IN AS EXPECTED THIS MORNING WITH WIDESPREAD
MVFR WITH INTERMINGLED IFR CONDITIONS PRESENT ACROSS CENTRAL TAF
SITES WITH KDRT MVFR AS WELL. AMPLE MOISTURE IN THE LOWER LAYERS WILL
TAKE SOME TIME TO MIX OUT THROUGH 15-17Z WITH A GRADUAL IMPROVEMENT
THROUGH MVFR TO EVENTUAL VFR FALL ALL SITES BY LATE MORNING TO EARLY
AFTERNOON. A COMPLEX OF SHOWERS AND STORMS IS MOVING INLAND NEAR
KVCT BUT WILL LIKELY MISS THE CENTRAL SITES. FEEL MOST SCATTERED
ACTIVITY WILL REMAIN SOUTHEAST OF THE MAIN TERMINALS AND HAVE
REFRAINED FROM VCTS WORDING THIS TAF CYCLE. TRENDS WILL NEED TO BE
MONITORED HOWEVER FOR POSSIBLE INCLUSION ON 18Z CYCLE. SURFACE WINDS
ARE LIGHT AND VARIABLE CURRENTLY BUT WILL PICK UP TO 10-15 KT THIS
AFTN FROM THE SOUTHEAST TO SOUTH DIRECTION.
PREV DISCUSSION... /ISSUED 333 AM CDT FRI AUG 21 2015/
SHORT TERM (TODAY THROUGH SATURDAY)...
A N-S ORIENTED SHEAR AXIS MOST NOTABLE IN THE MID LEVELS OVER S TX
AND ADJACENT AREAS OF NERN MEXICO SHOULD BRING ANOTHER DAY OF
CONVECTION AND MODERATED DAYTIME TEMPERATURES FOR THE EASTERN
HALF OF SOUTH CENTRAL TX. WHILE THE FRONTAL ZONE THAT BROUGHT WELL
BELOW NORMAL MAX TEMPS TO THE AREA THURSDAY HAS RETREATED
NORTH...SOME COASTAL TROUGHING IS STILL NOTED NEAR CRP...AND A
SMALL COMPLEX OF STORMS CONFIRMS THE UNSTABLE ENVIRONMENT THAT
COULD SPREAD INLAND LATER THIS MORNING. RAPID REFRESH MODEL RUNS
DEPICT EARLY DESTABILIZATION NEAR AND EAST OF I-35 TODAY...BUT
EARLIER RUNS OF THE HRRR WERE SHOWN TO BE TOO AGGRESSIVE WITH
CONVECTION IN THE PRE-DAWN HOURS. ADDITIONAL MOISTURE AND POSSIBLE
INSTABILITY IS MOVING IN FROM NW FLOW ALOFT FROM WEST TX...BUT
WITH ONLY THE 00Z NSSL WRF MODEL SHOWING AN IMPACT OVER OUR
WESTERN COUNTIES VERSUS SEVERAL THAT DO NOT...WILL STICK WITH THE
CONSENSUS POPS FOR THE SERN TWO-THIRDS OF THE FORECAST AREA.
BLENDED GUIDANCES CONTAIN ARTIFACTS OF EARLIER FORECAST HIGHER
TEMPS...SO OPTED FOR A BLEND OF MAV/MET FOR HIGHS.
MODEL RUN TO RUN TRENDS IN THE EARLY PERIODS SHOW MORE SHEAR THAN
EARLIER RUNS...SO WILL FOLLOW THIS TREND TO KEEP A SLIGHTLY LESS
STABLE PICTURE FOR OUR SOUTHERN/WRN COUNTIES FOR SATURDAY.
INCREASED RIDGING AND DRY AIR ENTRAINMENT FROM THE NORTH SHOULD
PRECLUDE CONVECTION OVER MOST OF SOUTH CENTRAL TEXAS...BUT THE
WESTWARD SHIFTING SHEAR AXIS SHOULD PULL SOME MOISTURE WITH IT TO
BRING A SLIGHT CHANCE OF DAYTIME CONVECTION OVER THE RIO GRANDE
PLAINS. MEANWHILE SOUTHERN PARTS OF THE COASTAL PLAINS LOSE THE
CYCLONIC SHEAR BUT MAINTAIN LOCALLY HIGHER PWAT VALUES FOR ONE
MORE DAY. WILL FAVOR THE GFS BASED GUIDANCE FOR WARMER TEMPS TO
REGAIN CONTROL OVER CENTRAL TX WHERE THE DRIER AND MORE STABLE MID-
LEVEL AIR MOVES IN.
LONG TERM (SATURDAY NIGHT THROUGH THURSDAY)...
THE BRIEF BREAK FROM THE HEAT IS ALL BUT FORGOTTEN BY SUNDAY. THE
GFS AND ECMWF BOTH BUILD A STRONG RIDGE OVER THE SOUTHERN ROCKIES
WITH AN AXIS THAT EXTENDS SE ACROSS CENTRAL TX. WILL SHADE TOWARD
THE HIGHER MEX GUIDANCE ON MAXES SUNDAY THROUGH WEDNESDAY AS
AUGUST RAINS HAVE BEEN MOSTLY TOO SPARSE TO PROVIDE FEEDBACK
THROUGH SOIL AND VEGETATION. LATE MONDAY THROUGH DAYTIME
WEDNESDAY...THERE IS A SIGNAL FOR MID-LEVEL MOISTURE POOLING TO
SPREAD SOUTH FROM NORTH TX AS NORTHERLY FLOW INCREASES ALOFT. THUS
WILL SHADE TOWARD THE SLIGHTLY MORE UNSTABLE ECMWF OVER THE
SLIGHTLY DRIER GFS FOR THOSE DAYS. LITTLE OR NO CONVECTION IS
SHOWN BY EITHER MODEL FOR THE REMAINDER OF NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 91 76 98 77 99 / 40 10 10 - -
AUSTIN BERGSTROM INTL AIRPORT 92 73 97 75 98 / 40 10 10 - -
NEW BRAUNFELS MUNI AIRPORT 92 75 98 76 98 / 30 10 10 - -
BURNET MUNI AIRPORT 92 74 97 75 98 / 20 10 10 - -
DEL RIO INTL AIRPORT 96 76 98 78 99 / 10 - 20 - -
GEORGETOWN MUNI AIRPORT 92 76 96 76 98 / 40 10 10 - 10
HONDO MUNI AIRPORT 95 74 96 75 97 / 20 10 10 - -
SAN MARCOS MUNI AIRPORT 92 75 98 76 99 / 30 10 10 - -
LA GRANGE - FAYETTE REGIONAL 91 76 96 76 98 / 50 20 20 10 10
SAN ANTONIO INTL AIRPORT 93 76 97 77 98 / 30 10 10 - -
STINSON MUNI AIRPORT 93 76 98 77 99 / 30 20 10 - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...TREADWAY
SYNOPTIC/GRIDS...04
PUBLIC SERVICE/DATA COLLECTION...10
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1236 PM CDT FRI AUG 21 2015
.DISCUSSION...UPDATED FOR 18Z AVIATION.
&&
.AVIATION...LATEST RUN OF THE HRRR RE-DEVELOPS SHOWERS AND
THUNDERSTORMS ACROSS SOUTH TEXAS THIS AFTERNOON. WILL HANDLE THE
POTENTIAL FOR CONVECTION WITH VCTS REMARKS FOR NOW AND WILL AMEND
AS NECESSARY. VFR CONDITIONS INITIALLY WILL THEN TRANSITION TO
MVFR LEVELS OVERNIGHT INTO EARLY SATURDAY MORNING. LOW CLOUDS
SHOULD MIX OUT AROUND 14Z/15Z WITH A RETURN TO VFR CONDITIONS.
&&
.PREV DISCUSSION... /ISSUED 905 AM CDT FRI AUG 21 2015/
DISCUSSION...INCREASED POPS ACROSS THE MIDDLE TEXAS COASTAL
WATERS AND IMMEDIATE COASTAL COUNTIES BASED ON LATEST RADAR
TRENDS.
PREV DISCUSSION... /ISSUED 645 AM CDT FRI AUG 21 2015/
DISCUSSION...NOTE AVIATION DISCUSSION BELOW.
AVIATION...A MIXTURE OF VFR/MVFR CEILINGS WL PERSIST THIS MORNING
DRG AND OUTSIDE OF ISOLATED/SCATTERED SHOWERS OVER THE COASTAL
BEND/OFFSHORE. CONTINUE TO ANTICIPATE THE DEVELOPMENT OF
SCATTERED SHOWERS AND THUNDERSTORMS DRG THE LATE MORNING/AFTERNOON
OVER LAND MAINLY EAST OF U.S. ROUTE 281. EXPECT CONVECTION TO
THEN MOVE GENERALLY WEST OF U.S. ROUTE 281 DRG THE EVENING.
NOCTURNAL CONVECTION EXPECTED AGAIN OVERNIGHT NEAR THE
COAST/OFFSHORE. GENERALLY LGT/VARIABLE WIND EARLY THIS MORNING
TRANSITIONING TO MODERATE ONSHORE FLOW DRG THE MID/LATE AFTN
HOURS TODAY. BECOMING LGT AGAIN OVERNIGHT.
PREV DISCUSSION... /ISSUED 601 AM CDT FRI AUG 21 2015/
SHORT TERM (TODAY THROUGH SATURDAY)...CONVECTION EARLY THIS
MORNING OVER THE MSA/ERN CWA NEAR A SFC TROUGH. GFS/NAM
STREAMLINES DEPICT AN UPPER TROUGH AXIS OVER THE ERN CWA. GOES
SOUNDER DPI PWAT SUGGEST COPIOUS MSTR OVER THE CWA/MSA. NAM
PREDICTS SIGNIFICANT CAPE/LOW CIN THIS AFTN. EXPECT THE
COMBINATION OF THE UPPER SYSTEM/MSTR/INSTABILITY/SEA BREEZE TO
RESULT IN SCATTERED CONVECTION TODAY. EXPECT CONVECTION TO SHIFT
TO THE WRN CWA DRG THE EVENING. CONCUR WITH THE GFS/NAM WHICH
MAINTAINS THE UPPER PATTERN TONIGHT/SATURDAY. THUS EXPECT NOCTURAL
CONVECTION TO DEVELOP AGAIN OVER THE MSA OVERNIGHT/EARLY SATURDAY
FOLLOWED BY AFTN CONVECTION OVER THE CWA.
LONG TERM (SATURDAY NIGHT THROUGH THURSDAY)...THE UPPER LEVEL
TROUGH AXIS IS PROGD TO SHIFT FARTHER W SAT NIGHT/SUN WITH HIGH
PRESSURE BUILDING ACROSS S TX FROM THE NE AND E. THIS WILL BRING
DRIER AIR TO S TX...BUT STILL SUFFICIENT MOISTURE FOR ISOLD SEA
BREEZE CONVECTION SUN AFTERNOON. THE HIGH PRESSURE ALOFT IS PROGD TO
REMAIN IN CONTROL THROUGH THE REMAINDER OF NEXT WEEK WITH ONLY ISOLD
CONVECTION EXPECTED ON TUE ACROSS THE NE AND E CWA DUE TO A WEAK
SHORT WAVE ROUNDING THE SE PERIPHERY OF THE RIDGE.
OTHERWISE...GENERALLY DRY FCST FOR THE EXTENDED. TEMPS ARE EXPECTED
TO BE NEAR NORMAL NEXT WEEK ALONG WITH A WEAK TO OCCASIONALLY MOD
ONSHORE FLOW. MODELS DO SHOW VERY LIGHT OFFSHORE WINDS EACH
NIGHT/EARLY MORNING THROUGH MUCH OF NEXT WEEK WHICH WILL HELP KEEP
MN TEMPS A TAD COOLER THAN THIS PAST WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 78 93 79 94 78 / 20 20 10 20 10
VICTORIA 76 94 76 95 76 / 20 30 10 20 10
LAREDO 78 99 78 101 77 / 20 20 10 10 10
ALICE 76 96 77 96 76 / 20 30 10 20 10
ROCKPORT 80 90 81 91 80 / 20 20 10 20 10
COTULLA 75 98 76 100 76 / 20 20 10 10 10
KINGSVILLE 77 95 78 95 77 / 20 20 10 20 10
NAVY CORPUS 80 89 81 90 80 / 20 20 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
TB/78...AVIATION
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1242 PM CDT FRI AUG 21 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 318 AM CDT FRI AUG 21 2015
MOST OF THE FORECAST TIME THIS MORNING WAS ENSURING WE WERE ON TRACK
WITH RAIN CHANCES IN THE RETURN FLOW TODAY....CLOUDS ON
SATURDAY...BUT MAINLY THE SATURDAY NIGHT THUNDERSTORM THREATS AND
ANY MESSAGING THAT WILL BE NEEDED FOR THOSE OUTDOORS.
CURRENT OBSERVATIONAL DATA AS OF 21.07Z INDICATES NW-SE ORIENTED
CLOUD BANDING AROUND 10KFT ACROSS CENTRAL MN ASSOCIATED WITH
FRONTOGENESIS IN THE 800-900 MB LAYER PER LATEST RAP ANALYSIS.
TSRA AND LIGHTNING IN NWRN IA ON THE NOSE OF THE LOW-LEVEL JET PER
88D VWPS AND RAP ANALYSIS. SPC MESOANALYSIS SHOWING THAT TSRA IS
ON THE NORTHERN EXTENT OF THE MUCAPE REGION /ONLY ABOUT 250 J/KG
THERE/.
GOES FOG PRODUCT AND SURFACE OBSERVATIONS SHOW A LOWER CLOUD FIELD
OVER OK/TX SOUTH IN A RICH MOIST POOL OF SURFACE DEWPOINTS OVER
65F...AND 925MB DEWPOINTS AT 18C PER 21.00Z RAOBS. WILL HAVE TO
WATCH THIS AREA AS IT ADVECTS NORTHWARD AHEAD OF THE FRONT THAT IS
MOVING IN FOR SATURDAY NIGHT...ASSOCIATED WITH THE SHORTWAVE
TROUGH NOW WORKING SOUTHWARD THROUGH BRITISH COLUMBIA /PER GOES
WATER VAPOR/. RAP ANALYSIS INDICATES THIS SPINNER HAS A TROPOPAUSE
FOLD DOWN TO ROUGHLY 750 MB...SO A POTENT VORTEX.
SHORT TERM GUIDANCE SUPPORTS EVOLVING THE FRONTOGENESIS AND THE
LOW-LEVEL JET NOSE CONVERGENCE NORTHEAST THROUGH THE FIRST PORTION
OF TODAY INTO NRN WI BY AFTERNOON. THERE WILL LIKELY BE VERY LIGHT
RADAR RETURNS AND PER 00Z RAOB DATA...SOME PRETTY DRY AIR TO
OVERCOME BELOW THE ACCAS CLOUD BASE /10KFT/. FOR NOW...HAVE KEPT
THE HIGHER PROBABILITY DRY FORECAST. SPRINKLES OR AN ISOLATED
WETTING SHOWER MAY BE POSSIBLE WITH FORCING EVOLUTION NEWRD.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 318 AM CDT FRI AUG 21 2015
NO BIG CHANGES DURING THIS PERIOD.
SOUTHWESTERLY FLOW WILL PREVAIL SATURDAY AND PRE-FRONTALLY WILL
NEED TO WATCH THE SURGE OF 925 MB MOISTURE NORTHWARD TONIGHT.
CONSENSUS 21.00Z GUIDANCE SUGGESTS THIS TONGUE REMAINS WEST OF THE
AREA UNTIL FRONT ARRIVES SAT EVENING. HAVE INCREASED WIND GUSTS
SATURDAY WITH STRONGER LOW-LEVEL WIND FIELD SUGGESTED AND MIXING
DEPTH INTO THE 35-38KT CONSENSUS 900MB WINDS.
TIMING IS ABOUT THE SAME AS PREVIOUS FORECASTS FOR FRONT TO
BECOME ACTIVE TO THE WEST OF THE AREA LATER SATURDAY. THIS FRONT
IS ASSOCIATED WITH THE BRITISH COLUMBIA SHORTWAVE AS IT DIGS
SOUTHEAST INTO CENTRAL MN...THEN EJECTS NORTHEAST OVER DULUTH.
THUS...THE AREA ISNT DIRECTLY HIT BY THE MID-UPPER TROPOSPHERIC
FORCING...WHICH FAVORS BETTER CONVECTION TO EJECT NORTHEAST...BUT
BROAD ASCENT FROM LARGE SCALE FORCING IS OVER THE AREA. THE CAPE
AXIS IS VERY NARROW...RIGHT ALONG THE FRONT...WITH A STOUT CAP OUT
AHEAD SUGGESTED. MUCAPE HAS REMARKABLE DROP SUGGESTED IN THE
MODEL GUIDANCE FROM 7PM TO 1 AM...ABOUT 2500 IN PEAK HEATING WEST
OF THE FORECAST AREA...TO ABOUT 750 J/KG BY 1 AM ON THE MISS
RIVER. THE WESTERN FORECAST AREAS OF NERN IA AND SERN MN HAVE THE
MOST POTENTIAL FOR SEVERE STORMS FOR A SMALL WINDOW SATURDAY
EVENING AS THE STORMS WEAKEN HEADING EAST. SPC DAY 2 RISK HAS
SHIFTED THE SLIGHT RISK EAST INTO THAT AREA...BUT NOT TOO MUCH HAS
CHANGED. MODEST 0-3KM WIND SHEAR WOULD FAVOR LINE SEGMENTS
PROMOTING DAMAGING WINDS. THE 0-3KM SHEAR VECTOR IS ALIGNED
PERPENDICULAR TO THE FRONT OR CONVECTIVE LINE...PROMOTING BETTER
COLD POOL MAINTENANCE.
SEVERE THREAT DEPENDS ON TIMING OF THE FRONT AND STORMS. ARRIVAL
IN THE EARLY EVENING WOULD FAVOR HIGHER SEVERE STORM CHANCES PER
HIGHER CAPE IN MODEST LOW-LEVEL SHEAR. CONSENSUS MODEL GUIDANCE IS
A MID-LATER EVENING APPROACH OF STORMS IN NERN IA AND SERN MN
WITH STORMS JUST PAST PEAK AND INTO WEAKENING STAGE...WITH COLD
POOLS THAT COULD PROBABLY PRODUCE ISOLATED WIND DAMAGE. WILL TAKE
A SLIGHT STEP UP IN MESSAGING MOVING TO STRONG TO ISOLATED SEVERE
STORMS.
A COOL FIRST HALF OF THE WEEK IN NORTHWEST FLOW WITH DRIER
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1242 PM CDT FRI AUG 21 2015
MAIN TAF CONCERNS ARE WINDY CONDITIONS AT BOTH TAF SITES THROUGH TAF
PERIOD. LATEST METARS INDICATE SOUTH TO SOUTHWEST WINDS HAVE
INCREASED TO 15 KNOTS WITH GUST OF 20 TO 28 KNOTS ACROSS THE AREA.
DUE TO FULL SUN THIS AFTERNOON...WINDS WILL MIX DOWN FROM ALOFT AND
CONTINUE TO BE SUSTAINED AT 15 TO 17 KNOTS WITH GUSTS 25 TO 30 KNOTS
AT BOTH RST/LSE TAF SITES. WINDS WILL SLACK OFF A BIT AFTER 00Z WITH
SUNSET. HOWEVER...SUSTAINED WINDS ARE EXPECTED TO BE AROUND 15 KNOTS
THROUGH THE NIGHT TIME HOURS. PRESSURE GRADIENT TIGHTENS AHEAD OF AN
APPROACHING COLD FRONT SATURDAY AND EXPECT WINDS TO INCREASE AFTER
12Z AT BOTH RST/LSE TAF SITES. SUSTAINED WINDS OF 15 KNOTS WILL
PREVAIL AND GUSTS 25 TO 30 KNOTS...AND POTENTIALLY GUST TO AROUND
35 KNOTS AT RST TAF SITE LATE IN THE TAF PERIOD. VFR CONDITIONS
WILL PREVAIL THROUGH THE TAF PERIODS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...DTJ